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  • 1980-1984  (34,223)
  • Chemistry  (33,681)
  • Organic Chemistry  (3,406)
  • Ultrastructure  (541)
  • Nuclear reactions
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Year
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  • 1
    Electronic Resource
    Electronic Resource
    Carcinoid tumor of the uterine cervix (1984)
    Springer
    Virchows Archiv 402 (1984), S. 331-336 
    Details
    ISSN: 1432-2307
    Keywords: Carcinoid ; Uterine cervix ; Histopathology ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of carcinoid tumor of the uterine cervix is reported. The patient was a 76-year-old Japanese woman with a complaint of vaginal bleeding. She was clinically diagnosed as stage IVb carcinoma of the uterine cervix. Light microscopically, the tumor was characterized by formation of solid cell nests and, in limited areas, glandular structures. The tumor cells in solid cells nests showed positive argyrophil reaction but were negative for argentaffin reaction. At the ultrastructural level, the cytoplasm of the tumor cells contain numerous neurosecretory granules, microfilaments and well-developed Golgi complexes. On the bases of histochemical and electron microscopic features of tumor cells, the tumor was diagnosed as carcinoid tumor of the uterine cervix.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695086
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  • 2
    Electronic Resource
    Electronic Resource
    Ultrastructure of gill epithelial cells of Diopatra neapolitana (Annelida, Polychaeta) (1984)
    Springer
    Zoomorphology 104 (1984), S. 304-309 
    Details
    ISSN: 1432-234X
    Keywords: Ultrastructure ; Gills ; Epithelial cells ; Polychaeta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructure of gill epidermal cells of Diopatra neapolitana and their relationship with blood spaces are described. The existence of a basal infolding complex, related to the blood spaces, is also reported. A possible involvement of these cells in osmoregulation and ion interchange, apart from their well-known role in respiration, is suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00312012
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  • 3
    Electronic Resource
    Electronic Resource
    The ultrastructure of experimental arthrosis in dogs (1984)
    Springer
    International orthopaedics 7 (1984), S. 215-221 
    Details
    ISSN: 1432-5195
    Keywords: Experimental arthrosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Les auteurs ont réalisé une arthrose expérimentale chez le chien en injectant dans une articulation le liquide obtenu par ponction d'une autre articulation du même animal, dont le cartilage a été préalablement scarifié de façon aseptique. L'examen des surfaces articulaires en microscopie électronique montre des altérations dégénératives progressives au niveau de la matrice extra-cellulaire, des chondrocytes et de la membrane péri-cellulaire. Ces modifications augmentent après des injections répétées de liquide synovial. Dans une autre série d'animaux, on a injecté soit le culot de centrifugation, soit le surnageant et on a comparé les effets obtenus vis-à-vis des structures cellulaires et extra-cellulaires.
    Notes: Summary Experimental arthrosis was induced in previously healthy joints in a group of dogs by injection of fluid aspirated from another joint of the same animal previously damaged by trauma under sterile conditions. Using electron microscopy progressive degenerative changes were observed at the surface of the joint, in the extracellular matrix, in the chondrocytes and in the pericellular band. The changes increased following serial injections of the joint fluid. In another series, the joints were injected either with the centrifuged concentrate or the supernatant fluid and a comparison made of the contrasting effects upon the cellular and extracellular structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00266830
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  • 4
    Electronic Resource
    Electronic Resource
    Stromal cells of the fibroadenoma of the human breast (1984)
    Springer
    Virchows Archiv 404 (1984), S. 7-16 
    Details
    ISSN: 1432-2307
    Keywords: Fibroadenoma ; Stromal cells ; Actin ; Ultrastructure ; Myofibroblast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fourteen fibroadenomas of the human breast were examined by light and electron microscopy, and by immunohistochemistry for actin. They were classified into 3 groups according to their stromal patterns; myxoid, fibrous-cellular and sclerotic. Actin immunohistochemistry revealed that the stromal areas were strongly positive in the fibrous-cellular group and weakly positive in the myxoid and sclerotic groups. By electron microscopy the stromal cells in most cases of the myxoid and fibrous-cellular groups were fibroblasts, containing varying amounts of microfilaments, 5–7 nm in diameter (actin type filaments). However, a dense body was not usually present suggesting these stromal cells were variants of myofibroblasts. The amount of microfilaments in fibroblasts was greater in the fibrous-cellular group than in the myxoid group. This was consistent with the results of actin immunohistochemistry. In 3 cases of the fibrous-cellular group peculiar structures simulating Z-lines of striated muscles were noted in some stromal cells. Since no myosin filaments were detected, they were regarded as intermediate structures between Z-lines of striated muscles and dense bodies of smooth muscles. In the sclerotic group, stromal fibroblasts were sparse and had fewer organelles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704246
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  • 5
    Electronic Resource
    Electronic Resource
    A morphometric study on the ultrastructure of well-differentiated tumours and inflammatory mucosa of the human urinary bladder (1984)
    Springer
    Virchows Archiv 405 (1984), S. 25-39 
    Details
    ISSN: 1432-2307
    Keywords: Morphometry ; Human bladder tumour ; Human chronic cystitis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Transmission (TEM) and scanning electron microscopic (SEM) observations were performed on well-differentiated tumours and chronic cystitis in the human urinary bladder. SEM showed that the pleomorphic microvilli were present not only on the luminal surface of the tumour but also on the surface of inflammatory mucosa. The ultrastructure of six tumours and 5 cases of chronic cystitis was evaluated morphometrically. Bladder tumour and inflammatory mucosa were divided into several layers, namely outermost cells (S), subsurface cells just beneath these (S1), subsurface cells of 2 or 3 layers below (S23), intermediate cells of 2 or 3 layers above the basal cells (123), intermediate cells just above the basal cells (I1) and basal cells (Ba). Areas of nucleus, cytoplasm and cytoplasmic organelles, numbers of nucleoli, nuclear bodies, mitochondria and lysosomes together with irregularity of the cell and nucleus were estimated according to the methods of Weibel. A multi-variate analysis of variance on these variables showed that the above subdivision of layers was necessary for the comparison of tumour and inflammation. Discriminant analysis showed various differences between tumour and inflammatory mucosa. The results indicated that the Ba layer is the most effective site for differentiating the tumour from inflammation. Ba cells with large and irregular cytoplasm with an enlarged Golgi area, accompanied by many vacuolar structures, may be indicative of tumour rather than inflammation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00694923
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  • 6
    Electronic Resource
    Electronic Resource
    Neurogenic sarcomas in patients with neurofibromatosis (von Recklinghausen's disease) (1984)
    Springer
    Virchows Archiv 403 (1984), S. 361-376 
    Details
    ISSN: 1432-2307
    Keywords: Neurofibrosarcomas ; Neurogenic sarcomas ; Von Recklinghausen's disease ; Malignant schwannomas ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thirteen soft tissue neurogenic sarcomas from twelve patients with neurofibromatosis (Von Recklinghausen's disease) were ultrastructurally examined. Electron microscopic studies revealed a wide spectrum of morphological manifestations varying from schwannian to fibroblastic, histiocytic, fibrohistiocytic and relatively undifferentiated cellular proliferations. A similar variation on light microscopic appearances has been previously reported in these neurogenic sarcomas. Neurogenic sarcomas occurring in patients with neurofibromatosis (Von Recklinghausen's disease), represent a heterogenous group of neoplasms with various patterns of differentiation identified ultrastructurally. The morphologic expressions of these neurogenic neoplasms can be conceptualized as a disorderly growth of the various peripheral nerve cellular components, or, as has been previously suggested, as a result of the multipotential nature and metaplastic ability of Schwann cells. S-100 protein immunohistochemistry was only positive in those neoplasms ultrastructurally proven to represent schwannian cellular proliferations. This study serves to document the range of fine structure that may be found in neurogenic sarcomas, to correlate the ultrastructural findings with the light microscopic appearance of these tumors, to determine the specificity of the electron microscopic findings, and immunohistochemistry for S-100 protein and assess their possible value in differential diagnosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00737286
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  • 7
    Electronic Resource
    Electronic Resource
    Ultrastructural observations on the histogenesis of localized fibrous tumours of the pleura (benign mesothehoma) (1984)
    Springer
    Virchows Archiv 403 (1984), S. 413-424 
    Details
    ISSN: 1432-2307
    Keywords: Localized fibrous tumour of the pleura ; Benign mesothelioma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Five localized fibrous tumours of the pleura (benign mesothelioma) were studied ultrastructurally in order to elucidate their histogenesis. The histological subtypes of this benign fibrous lesion of the visceral pleura, i.e. the cellular, the collagenous, and the hyaline, were separately analysed. The tumours are composed of undifferentiated mesenchymal cells, intermediate and differentiated fibroblasts as well as collagenous interstitial tissue. The varying distribution of these cell elements account for the various histological subtypes. Morphological similarities between the mesenchymal tumour cells and the superficial mesothelial cells, which are always separated from the true tumour tissue by an intact basement membrane, were not observed. The different cellular elements can be regarded as parts of a continuous spectrum of cytodifferentiation, in which the mature fibroblasts are derived via intermediate forms from the undifferentiated cells. It is concluded that the localized fibrous tumours of the pleura arise from immature mesenchymal stem cells, which seems to be normally found in the submesothelial layer of the visceral pleura.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00737290
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  • 8
    Electronic Resource
    Electronic Resource
    Herpes oesophagitis (1984)
    Springer
    Virchows Archiv 404 (1984), S. 177-185 
    Details
    ISSN: 1432-2307
    Keywords: Oesophagitis ; Herpetic cell change ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultra-thin sections obtained from routine biopsy specimens and cytological smears of 3 cases, together with one autopsy case suggestive of herpes oesophagitis, clearly demonstrate herpes viruses. The infected epithelial cells reveal different stages of virus replication and propagation. Cowdry A type inclusion bodies, however, representing early alterations in the course of infection are less frequent. Ground-glass looking nuclei of light microscopical balloon cells and infected multinuclear giant cells of epithelial origin are characteristic changes of the late ulcerative stage of herpes oesophagitis usually seen at the time of detection. These typical virus induced cell changes are mostly to be found at the ulcers edge.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704062
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  • 9
    Electronic Resource
    Electronic Resource
    Mammosomatotroph hyperplasia associated with acromegaly and hyperprolactinemia in a patient with the McCune-Albright syndrome (1984)
    Springer
    Virchows Archiv 403 (1984), S. 77-86 
    Details
    ISSN: 1432-2307
    Keywords: Acromegaly ; hyperprolactinemia ; McCune-Albright syndrome ; pathology ; Pituitary ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An 11-year-old girl, with the McCune-Albright syndrome, exhibited fibrous dysplasia of several bones, skin pigmentation, precocious puberty, growth hormone hypersecretion, acromegaly and hyperprolactinemia. Histologic, immunocytologic and ultrastructural investigation of the surgically-removed pituitary showed massive mammosomatotroph hyperplasia. Since no adenoma was found, the abundance of these bihormonal cells, capable of producing both growth hormone and prolactin, was implicated in the causation of growth hormone and prolactin excess. Somatoliberin overproduction and/or somatostatin and dopamine deficiency could not account for the hypophysial abnormality, since changes in secretory rates of these hypothalamic hormones would lead to proliferation of mature somatotrophs and lactotrophs, rather than mammosomatotrophs. In our patient, a congenital hypothalamic malfunction might have been accompanied by hypersecretion of an unidentified releasing factor, resulting in pathologic differentiation of the pituitary and mammosomatotroph hyperplasia. Alternatively, mammosomatotroph hyperplasia may have been due to an inherent genetic or embryonic defect affecting primarily the pituitary. According to this interpretation, the pituitary lesion represented yet another developmental error in the setting of the McCune-Albright syndrome.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00689340
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  • 10
    Electronic Resource
    Electronic Resource
    Ameloblastic fibrosarcoma in the maxilla, malignant transformation of ameloblastic fibroma (1984)
    Springer
    Virchows Archiv 404 (1984), S. 253-263 
    Details
    ISSN: 1432-2307
    Keywords: Ameloblastic fibrosarcoma ; Histogenesis ; Histopathology ; Ultrastructure ; Fatal case
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This report presents a fatal case of ameloblastic fibrosarcoma arising from an ameloblastic fibroma, originating in the maxilla of 19-year-old Japanese male. An analysis of previously reported fatal cases of ameloblastic fibrosarcoma is included. In the course of the disease, the mesenchymal component of ameloblastic fibroma showed a dramatic histopathological transformation into sarcoma following multiple recurrence and the patient died of uncontrollable local infiltration of the cranial base. Although many cases have seemed to show disappearance of the epithelial component as malignant transformation progressed, many benign appearing ameloblastoid epithelial masses were scattered throughout the sarcomatous area even in the fatal stage in the present case. No distant metastases were found at autopsy. During multiple recurrences of the lesion, a little dysplastic dentin which was closely associated with both epithelial and mesenchymal components was found, though it could not be observed in autopsy material. Ultrastructural findings in autopsy material showed that the mesenchymal component consisted of undifferentiated mesenchymal cells, fibroblastic and fibrocytic cells with marked cellular and nuclear pleomorphism and that the epithelial component closely resembled the enamel organ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00694891
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  • 11
    Electronic Resource
    Electronic Resource
    Palmar fibromatosis (Dupuytren's contracture) (1984)
    Springer
    Virchows Archiv 405 (1984), S. 41-53 
    Details
    ISSN: 1432-2307
    Keywords: Fibromatosis ; Dupuytren's contracture ; Myofibroblast ; Ultrastructure ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Forty three cases of palmar fibromatosis were studied by light and electron microscopy, enzyme histochemistry, and ultrastructural immunohistochemistry. By electron microscopy most of the cells composing the nodules in both the proliferative and the involutional stages were identical to myofibroblasts. The myofibroblasts in the involutional nodules often possessed microfilament aggregates probably representing contraction of micro(actin)fllaments in the cytoplasm. The proliferative nodules revealed small perivascular haemorrhages and haemosiderin deposits accompanied by accumulation of macrophages and some lymphocytes; these inflammatory cells possibly secrete a certain growth factor inducing proliferation of genetically abnormal fibroblasts and myofibroblasts. Diaminopeptidase IV was detected in myofibroblasts and fibroblasts by enzyme histochemistry and ultrastructural immunohistochemistry; the enzyme may play a role in the metabolism of intercellular substances. Some perivascular mesenchymal cells, interpreted as variants of myofibroblasts, had moderate activity of alkaline phosphatase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00694924
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  • 12
    Electronic Resource
    Electronic Resource
    Length and shape of enamel crystals (1984)
    Springer
    Calcified tissue international 36 (1984), S. 550-555 
    Details
    ISSN: 1432-0827
    Keywords: Enamel crystals ; Length ; Shape ; Apatite ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary An original method for fractionating and preparing isolated crystals of homogeneous size was developed. It was demonstrated that enamel apatite crystals are at least 100 µm long. The flexibility of the very long crystallites was demonstrated. Crystal curvatures, accounting for the irregular course of the prisms through the enamel thickness, were visualized and measured. It was shown that in the deep forming enamel layer, lateral branches may grow out of the crystals and crystal fusing often occurs, inducing the crystallites to assume pyramidal shapes with their wide bases pointing toward the dentino-enamel junction and one or two tops toward Tomes' processes. During the maturation process, the two tops of the still immature crystals also fuse so that the mature crystals acquire a rodlike aspect, with parallel faces and steplike graduations along thec axis, allowing a close contact between the crystals. These results support the hypothesis that the crystallites would be continuous from the dentino-enamel junction to the surface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02405364
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  • 13
    Electronic Resource
    Electronic Resource
    Serotonin nerve fibers in the primary visual cortex of the monkey (1984)
    Springer
    Anatomy and embryology 169 (1984), S. 1-8 
    Details
    ISSN: 1432-0568
    Keywords: Serotonin ; Primary visual cortex ; Monkey ; Ultrastructure ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A quantitative and immunoelectronmicroscopical analysis of serotonin nerve fibers in the primary visual cortex of the monkey (Macaca fuscata) was made using a sensitive immunoperoxidase method for serotonin. The overall numerical density of serotonin-containing varicosities in the primate striate cortex was approximately 770,000/mm3 and the highest concentration of immunore-active varicosities (ca. 1,400,000/mm3) was observed in the upper portion of layer IVc, the next highest concentration being in layer IVb (ca. 1,180,000/mm3). At the ultrastructural level, the electron dense immunoreactive products were observed in the small granules (10–65 nm in diameter). The varicosities were usually small (0.5–1.0 μm in diameter) and made contact with both stellate and pyramidal cells. Serotonin fibers were often in close apposition to the poorly myelinated axons in layers IVb, V, and VI, and they rarely formed distinct synaptic structures with unlabelled neuronal elements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00300581
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  • 14
    Electronic Resource
    Electronic Resource
    The response of the uterine surface to ovarian hormones in the aged rat (1984)
    Springer
    Anatomy and embryology 169 (1984), S. 205-208 
    Details
    ISSN: 1432-0568
    Keywords: Rat uterus ; Epithelium ; Aging ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary By scanning electron microscopy uterine luminal epithelium of the rat was studied to determine whether aging alters ovarian hormone stimulated ultrastructural changes in that portion of the endometrial surface into which implantation takes place in the younger animal. Results show that in the aged rat this surface differentiates in response to ovarian hormones in a manner qualitatively similar to that which occurs in the young animal. Epithelial cells of ovariectomized rats, both young and aged, were polygonal in outline, flattened, or even somewhat concave, and had short microvilli. Following estrogen treatment cells of both groups were round or oval and bulged into the lumen. Cells of young rats were covered with long microvilli. Most cells of aged rats had microvilli of equal or greater length; a small number of epithelial cells had fewer and shorter microvilli. Cells of progesterone-treated young and aged animals both were covered with short microvilli and bore membrane protrusions. The protrusions varied in size, shape and numbers both within and between age groups. These findings suggest that differences in the surface ultrastructure of the aged uterus reflect age-related changes in hormone levels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00303150
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  • 15
    Electronic Resource
    Electronic Resource
    X-ray microanalysis of monoaminergic terminals in the nucleus tegmentalis dorsalis of the chicken (1984)
    Springer
    Anatomy and embryology 170 (1984), S. 87-91 
    Details
    ISSN: 1432-0568
    Keywords: Monoamine ; X-ray microanalysis ; Ultrastructure ; Brain stem ; Chicken
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary X-ray microanalysis after aldehyde-chromatedichromate treatment served to confirm the presence of monoaminergic terminals in the nucleus tegmentalis dorsalis (NTD) of the chicken. The monoaminergic terminals were represented as neuronal elements with electron-dense vesicles (EDVs) of several different shapes as seen in Eponembedded semi-thin sections. Conventional electron microscopic observations of the adjacent ultra-thin sections showed the EDVs to be comprised of spherical medium-sized (about 80 nm in diameter), large dense-cored (about 120 nm) and elongated granular vesicles (100–220 nm) in the same nerve varicosities. It is probable that the NTD, being a center of catecholaminergic efferent projections, may also receive direct monoaminergic inputs from an unknown area of the brain and/or from recurrent collaterals of the same catecholamine-containing neurons in the NTD.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319462
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  • 16
    Electronic Resource
    Electronic Resource
    Ultrastructure of the cumulus cell mass surrounding a human egg in the pronuclear stage (1984)
    Springer
    Anatomy and embryology 170 (1984), S. 107-112 
    Details
    ISSN: 1432-0568
    Keywords: Ultrastructure ; Cumulus ; Oocyte complex ; Human egg
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cumulus cell mass enclosing a penetrated human egg was studied. The egg, recovered from the Fallopian tube approximately 80 h after luteinizing hormone peak and 35 h after insemination, was surrounded by a large, expanded and dissociated cumulus. Dispersions of the outermost cumulus cell layers occurred during processing, the innermost cell layers remained attached enclosing the egg. The photomicrographs showed that the follicular cells were embedded in an intercellular matrix and contact via gap-junction-like structures between neighboring cells existed. Cumulus cell processes traversing the zona pellucida were not found. Two types of follicular cells coexisted within the cumulus, light and dark cells. These cellular types, were different in morphology and size. Light cells displayed cytoplasmic organelles normally associated with protein synthesis and steroidogenesis. Dark cells with long cytoplasmic processes were involved in sperm phagocytosis. It is suggested from the characteristics of the cytoplasmic organclles that dark cells seem to be modified light follicular cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319465
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  • 17
    Electronic Resource
    Electronic Resource
    Paired twisted filaments a new ultrastructural marker of human pinealomas? (1984)
    Springer
    Acta neuropathologica 65 (1984), S. 163-165 
    Details
    ISSN: 1432-0533
    Keywords: Human pinealomas ; Ultrastructure ; Paired twisted filaments ; Paired helical filaments ; Cytoskeleton
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Paired twisted filaments (PTF) forming helices are described in tumor cells of three human pine-alomas. Each filament was 8.11±1.55 nm wide. The maximal width of the helix was 16.62±2.62 nm. The periodicity of the constrictions was 26.63±4.49 nm. These characteristics appeared original, suggesting protein, filaments possibly specific of pinealocytes. The similarities and discrepancies between PTF and Alzheimer's paired helical filaments (PHF) are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690471
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  • 18
    Electronic Resource
    Electronic Resource
    Ultrastructure of heart muscle in short-term diabetic rats: influence of insulin treatment (1984)
    Springer
    Diabetologia 27 (1984), S. 397-402 
    Details
    ISSN: 1432-0428
    Keywords: Ultrastructure ; heart muscle ; streptozotocin ; short-term diabetes ; insulin treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of myocardium was examined in short-term diabetic rats. Morphometric analysis showed the volume of myocytic mitochondria, sarcoplasmic reticulum and lipid droplets to be significantly increased compared with those of control animals. Further measurements of mitochondria and sarcoplasmic reticulum indicated that the augmentation of these compartments was accountable by the enlargement of pre-existing mitochondria, which were swollen, and of pre-existing tubules of sarcoplasmic reticulum, the lumen of which was dilated. After insulin treatment the morphological changes were returned to normal which indicates that they were not due to the toxic effect of streptozotocin but were caused by the diabetic state per se. This suggestion is further supported by the finding that experimentally induced metabolic acidosis without diabetes did not cause any morphologically detectable changes in the heart muscle. It is concluded that short-term diabetes in the rat causes mitochondrial swelling, dilatation of sarcoplasmic reticulum and accumulation of lipid in cardiac myocytes, and that these changes are preventable with insulin treatment. We suggest that insulin may have an important role in the maintenance of metabolism in heart muscle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00304857
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  • 19
    Electronic Resource
    Electronic Resource
    Induction of the morphologic changes of both acute and chronic experimental myasthenia by monoclonal antibody directed against acetylcholine receptor (1984)
    Springer
    Acta neuropathologica 63 (1984), S. 131-143 
    Details
    ISSN: 1432-0533
    Keywords: Anti-acetylcholine receptor antibody ; Experimental autoimmune myasthenia gravis ; Monoclonal antibody ; Myasthenia gravis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To investigate pathogenic mechanisms in experimental autoimmune myasthenia gravis (EAMG) and myasthenia gravis (MG), we studied the acute and chronic effects in rats of injection of rat monoclonal antibodies (MCABs) directed against the acetylcholine receptor (AChR). Animals were severely weak 12 h after a single injection, at which time macrophages were found invading endplate regions of muscle and cholinesterase-stained regions were separted from the underlying muscle fibers. Ultrastructural studies showed findings identical to the acute phase of EAMG: degenerating postsynaptic membranes and invasion and phagocytosis of endplate regions by macrophages. Animals receiving sublethal doses of MCAB recovered clinically by 4–5 days after injection. Recovery was accompanied by a progressive decrease in the number of macrophages associated with endplates and reapposition to the myofibers of the cholinesterasestained regions. Animals injected once, or repeatedly over several months, remained clinically and electromyographically normal after recovery from the initial episode of weakness, but their endplate ultrastructure was highly simplified with blunted or absent synaptic folds and shallow or absent secondary synaptic clefts. These studies demonstrate that anti-AChR MCABs can induce the changes of both acute and chronic EAMG. There is good correlation between the inflammatory changes and the acute clinical disease but poor correlation between morphological and clinical parameters in the chronic syndrome. The latter observation suggests that severe ultrastructural changes, similar to those seen in chronic EAMG and MG, cannot account, at least in rats, for the clinical and electrophysiologic abnormalities of MG.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00697195
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  • 20
    Electronic Resource
    Electronic Resource
    Neurofibromatosis tumor and skin cells in culture (1984)
    Springer
    Acta neuropathologica 63 (1984), S. 269-275 
    Details
    ISSN: 1432-0533
    Keywords: Neurofibromatosis ; Cell culture ; Cell surface ; Cytoskeleton ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Structural proteins of cultured neurofibromatosis (NF) tumor and skin cells were studied with reference to control skin fibroblasts. In polyacrylamide gel electrophoresis (PAGE)/fluorography the banding patterns of the cell lysates were markedly similar. NF tumor cells, however, produced a 60 kD band with a stronger and a 48 kD band with a lighter protein staining and metabolic labeling intensity. Furthermore, skin cells were also characterized by a 26 kD protein and the tumor cells by a 22 kD protein with high metabolic labeling intensity. Neuraminidase/galactose oxidase/NaB3H4-labeled NF skin and control skin cells possessed a 220 kD protein that was less intensively labeled in the tumor cells. The banding pattern of the skin cells was also characterized by a protein with slightly lower molecular weight (86 kD) than that of the tumor cell lysates (90 kD). In all cell lines studied indirect immunofluorescence stainings revealed bright arrays of vimentin type intermediary filaments but no desmin, cytokeratin, glial fibrillary acidic protein (GFAP), or neurofilament proteins. NF skin and control skin cells possessed well developed actin-containing bundles of microfilaments, while those of the tumor cells lacked a typical stress-fiber organization. The general morphology of the tumor cell cultures was also irregular. Transmission electron microscopy revealed no basic differences in the structure of intermediary filaments or microfilaments. The present data provide basic knowledge of neurofibromatosis skin and tumor cells and demonstrate that cultured cells originating from neurofibromas are defective in both their intracellular and extracellular organization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687332
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  • 21
    Electronic Resource
    Electronic Resource
    Ultrastructure of cerebellar capillary hemangioblastoma (1984)
    Springer
    Acta neuropathologica 64 (1984), S. 308-318 
    Details
    ISSN: 1432-0533
    Keywords: Angiogenesis ; Cerebellar hemangioblastoma ; Degranulation ; Heparin ; Mast cell ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The topographic distribution, population density, and ultrastructural features of mast cells were studied in six cases of cerebellar capillary hemangioblastoma. The vascular area of tumor tissue contained large numbers of mast cells (6.3 cells/high power field, ×400) in comparison with hyalinized area (0.3 cell) and adjacent cerebellar tissue (〈0.1 cell). Close association of mast cells with endothelial cells and stromal cells was found. The morphology of mast cell granules and their degranulation through dissolution of granule contents and exocytosis were illustrated. The findings suggest that an increased number of mast cells may represent one of the characteristic histological features of capillary hemangioblastoma, and continuous degranulation of mast cell granules with release of heparin may play an important pathophysiologic role in the vascular proliferation and expansion of the tumor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690396
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  • 22
    Electronic Resource
    Electronic Resource
    Isolation and characterization of a new coccoid methanogen, Methanogenium tatii spec. nov. from a solfataric field on Mount Tatio (1984)
    Springer
    Archives of microbiology 137 (1984), S. 308-315 
    Details
    ISSN: 1432-072X
    Keywords: Methanogenium tatii ; Ultrastructure ; Physiology ; Glycoproteins ; DNA-DNA Homology ; Taxonomy ; Archaebacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A new coccoid methanogen, Methanogenium tatii, was isolated and characterized. The mesophilic isolate can grow on and produce methane from H2:CO2 and formate. For growth acetate is strictly required. The cell shape, the G+C content of 54 mol% and DNA-DNA homology data suggest it to be a Methanogenium species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00410727
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  • 23
    Electronic Resource
    Electronic Resource
    Fine structure of the knobby spore type of Streptomyces torulosus (1984)
    Springer
    Archives of microbiology 138 (1984), S. 229-232 
    Details
    ISSN: 1432-072X
    Keywords: Actinomycetes ; Streptomyces torulosus ; Morphology ; Ultrastructure ; Verrucate spores ; Knobby ornamentation ; Sheath
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The type strain of Streptomyces torulosus Lyons and Pridham (1971) was studied by scanning- and transmission electron microscope. Spore chains were formed in spirals by aerial mycelium. The spores were connected by nozzles in which small channels could be observed. The knobby ornamentations of the spores arised on a thin fibrous sheath, enveloping the spore chains. These irregular blunt projections, called knobs, had varying diameters of 100 to 250 nm. The base of the knob, consisting of globose to flattened electron dense material, was sitting directly on the sheath. It was covered by several small vesicles of the same material. Each hollow vesicle beared a thin bowlshaped shell of electron transparent material. In general, the cupular bowls and their supporting vesicles became easily depressed on their base, but not detached from the surface of the spores. This type of knobby spore ornamentation was suggested to be designated as a verrucate spore type.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00402126
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  • 24
    Electronic Resource
    Electronic Resource
    Membrane-bound nitrite oxidoreductase of Nitrobacter: evidence for a nitrate reductase system (1984)
    Springer
    Archives of microbiology 140 (1984), S. 153-158 
    Details
    ISSN: 1432-072X
    Keywords: Nitrobacter hamburgensis ; Nitrite oxidoreductase ; Nitrate reductase ; Molybdenum iron-sulfur protein ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Nitrite oxidoreductase, the essential enzyme complex of nitrite oxidizing membranes, was isolated from cells of the nitrifying bacterium Nitrobacter hamburgensis. The enzyme system was solubilized and purified in the presence of 0.25% sodium deoxycholate. Nitrite oxidoreductase oxidized nitrite to nitrate in the presence of ferricyanide. The pH optimum was 8.0, and the apparent K m value for nitrite amounted to 3.6 mM. With reduced methyl-and benzylviologen nitrite oxidoreductase exhibited nitrate reductase activity with an apparent K m value of 0.9 mM for nitrate. NADH was also a suitable electron donor for nitrate reduction. The pH optimum was 7.0. Treatment with SDS resulted in the dissociation into 3 subunits of 116,000, 65,000 and 32,000. The enzyme complex contained iron, molydbenum, sulfur and copper. A c-type cytochrome was present. Isolated nitrite oxidoreductase is a particle of 95±30 Å in diameter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00454918
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  • 25
    Electronic Resource
    Electronic Resource
    Ultrastructural changes in rat Clara cells induced by a single dose of O,S,S-trimethyl phosphorodithioate (1984)
    Springer
    Archives of toxicology 56 (1984), S. 59-65 
    Details
    ISSN: 1432-0738
    Keywords: Trialkylphosphorothioates ; Rat ; Lung ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The oral administration of an LD50 dose (25 mg/kg) of O,S,S-trimethyl phosphorodithioate to rats induced immediate, cholinergic symptoms. A delayed respiratory crisis followed, 3–4 days later, involving a pronounced increase in lung weight and extensive injury to the alveolar epithelium. This compound also induced the immediate liberation of secretory granules from the Clara cells. Minor changes in the surface appearance of these cells were also observed but no signs of injury were found in any cells of the bronchiolar epithelium. The complement of secretory granules was monitored, by the morphometric analysis of ultrathin sections. Clara cells from control animals were found to contain 9.55±1.16 (SEM) granules per cell profile. The Clara cells from dosed animals were largely devoid of granules until the 3rd day after administration. Many of these agranular cells were arranged in clusters and often showed signs of mitotic division. In surviving animals the subsequent replacement of granules resulted in a large increase in the numbers present and many exhibited abnormal morphology. Over twice the normal complement of granules, 22.45±0.42 (SEM) per cell profile, was found 6 days after dosing. The complement of granules subsequently returned to normal levels and the clusters of Clara cells were resolved within 14 days of dosing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00316355
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  • 26
    Electronic Resource
    Electronic Resource
    Synaptology of the hypoglossal nucleus in the rat (1984)
    Springer
    Experimental brain research 57 (1984), S. 22-32 
    Details
    ISSN: 1432-1106
    Keywords: Ultrastructure ; Synaptology ; Hypoglossal nucleus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The purpose of this study was to define the types and distribution of synaptic terminals in the hypoglossal nucleus (XII) of the rat. Based on differences in bouton and vesicle size and shape, synaptic specializations and association with postsynaptic organelles, five types of terminals were identified in XII. In order of decreasing frequency they were: 1) S-boutons (spherical vesicles with an asymmetrical synapse); 2) F-boutons (flattened vesicles with a symmetrical synapse); 3) P-boutons (pleomorphic admixture of flattened and spherical vesicles with a symmetrical synapse); 4) C-boutons (pleomorphic vesicles with a subsynaptic cistern); and 5) Tboutons (spherical vesicles with an asymmetrical synapse and subsynaptic dense bodies). S-boutons were the predominant type found on dendrites, while boutons containing flattened vesicles were more prevalent on motoneuron somata. C-boutons were restricted exclusively to cell bodies and large dendrites, and T-boutons were seen primarily on smaller dendritic profiles. These results are, in general, comparable to those previously described in the ventral horn and cranial nerve motor nuclei in several species. However, differences were noted. Specifically, large M-boutons and axo-axonic synapses were not observed in the present study. The functional significance of these findings are discussed in relation to oro-lingual behaviour.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231128
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  • 27
    Electronic Resource
    Electronic Resource
    4-Ammopyridine-induced ultrastructural alterations of pinched-off nerve terminals from rat cerebral cortex (1984)
    Springer
    Experimental brain research 54 (1984), S. 385-389 
    Details
    ISSN: 1432-1106
    Keywords: Synaptosome ; 4-Aminopyridine ; Ultrastructure ; Exocytosis ; Recycling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pinched-off nerve terminals (synaptosomes) from rat cerebral cortex were depolarized with 60 mM KCl and treated with 20 mM 4-aminopyridine in order to evaluate ultrastructural alterations. The empty presynaptic terminals were counted and their number was given as a percentage of the normal terminals. The proportion of empty terminals increased from 10.47±1.56% to 32.45±1.88% (P 〈 0.001) following treatment with 20 mM 4-aminopyridine. This effect of 4-aminopyridine depended on the presence of Ca++ in the incubation medium. The results are discussed in terms of facilitation by 4-aminopyridine of exocytotic transmitter release. We think that the increase of the empty synaptosomes was due to the exhaustion or inhibition of the synaptic vesicle recycling mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236242
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  • 28
    Electronic Resource
    Electronic Resource
    Epidermoid metaplasia in apocrine cystadenoma of the penis (1984)
    Springer
    Archives of dermatological research 276 (1984), S. 170-177 
    Details
    ISSN: 1432-069X
    Keywords: Penile apocrine cystadenoma ; Ultrastructure ; Filamentous fuzzy coat ; Epidermoid metaplasia ; Peridermlike cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two cystadenomas occurring near the frenulum of the penis revealed a predominantly secretory pseudostratified columnar epithelium with PAS-reactive dome-shaped cytoplasmic protrusions at the luminal cellular parts. The content of secretory vacuoles was discharged into the cyst lumen by an exocytotic (eccrine) and ballooning type of extrusion. There were no indications of a real apocrine extrusion mechanism. No histogenetic derivation of these penile cystadenomas from apocrine sweat glands could be proved. An antennalike filamentous fuzzy coat on the luminal cytoplasmic membrane was most remarkable. Regionally, an epidermoid differentiation had developed. Morphologically, this process had begun just above the basal cell layer which had remained unchanged and led to the establishment of a stratified epithelium.Hyalin lamellarlike flattened cells at the luminal part displayed necrobiotic features and resembled periderm cells. There was no keratin pattern. Luminal cells of epidermoid differentiation still revealed a filamentous fuzzy coat which indicated that the undifferentiated cuboidal basal cells basically had a prospective secretory meaning and probably represented the target cells in the process of metaplasia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00414015
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  • 29
    Electronic Resource
    Electronic Resource
    Ultrastructural observation on a colloid cyst of the third ventricle (1984)
    Springer
    Acta neuropathologica 65 (1984), S. 41-45 
    Details
    ISSN: 1432-0533
    Keywords: Colloid cyst ; Third ventricle ; Ultrastructure ; Pathogenesis ; Rathke's cyst
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The case involves a colloid cyst of the third ventricle in a 20-year-old man. The lining epithelia of the cyst were composed of two different types of epithelial cells; stratified squamous cells and mucincontaining columnar cells. The presence of both squamous and glandular cells in the cyst wall supports the contention that the colloid cyst in the present case derived from an non-neuroepithelial source. The clinico-pathology of this cystic tumor is compared here with other epithelial cysts of the central nervous system (CNS), especially Rathke's cyst.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00689826
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  • 30
    Electronic Resource
    Electronic Resource
    Ultrastructural morphometry of collagen from lamina propria during experimental oral carcinogenesis and chronic inflammation (1984)
    Springer
    Journal of cancer research and clinical oncology 107 (1984), S. 183-194 
    Details
    ISSN: 1432-1335
    Keywords: Collagen ; Stereology ; Oral carcinogenesis ; Inflammation ; Ultrastructure ; Lamina propria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Stereological point-counting methods were used to determine the volumetric alterations in collagen from the lamina propria immediately beneath the epithelial-connective tissue junction in hamster check-pouch mucosa treated with the chemical carcinogen DMBA. In addition, a non-neoplastic inflammatory control was evaluated in which a delayed hypersensitivity reaction was induced by the contact-sensitising agent DNCB. DMBA-treated tissues were assigned to histopathologically defined hyperplasia, dysplasia and carcinoma stages. The volume densities of collagen present in unit volume of extracellular lamina propria were found to decrease progressively and significantly in DMBA-treated tissues when compared with values obtained from normal untreated mucosa. Values from the inflammatory control were comparable with those from the dysplasia stage of carcinogenesis. The mechanisms responsible for these decreases in collagen volume density are unknown, but contributory factors might include collagen destruction by enzymes originating in either the epithelium or the cells of the inflammatory infiltrate, dilution of collagen produced by inflammatory oedema or alterations in the synthetic capabilities of fibroblasts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01032605
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  • 31
    Electronic Resource
    Electronic Resource
    Glycerol effects on the transport of macromolecules in the lateral cochlear wall (1984)
    Springer
    European archives of oto-rhino-laryngology and head & neck 239 (1984), S. 49-59 
    Details
    ISSN: 1434-4726
    Keywords: Glycerol ; Inner ear ; Ultrastructure ; Cellular and paracellular transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect has been studied of intravenously administered glycerol on paracellular and cellular transport of macromolecular HRP tracer in the lateral cochlear wall. The findings indicate osmotically induced diffusion phenomena by the opening of shunt pathways through junctional complexes in the stria vascularis. Vesicular transport is accelerated, direction of transport however is not affected by the changed osmolality.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00454262
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  • 32
    Electronic Resource
    Electronic Resource
    Ultrastructural and histophysiological studies on the blood-nerve barrier and perineurial barrier in leprosy neuropathy (1984)
    Springer
    Acta neuropathologica 64 (1984), S. 282-296 
    Details
    ISSN: 1432-0533
    Keywords: Blood-nerve Barrier ; Perineurial barrier ; Leprosy neuropathy ; Ultrastructure ; Ferritin ; Ageing ; Drug treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Onset and nature of ultrastructural changes in endoneurial vasa nervorum during the pathogenesis of leprosy neuropathy and possibly associated alterations in the “blood-nerve barrier” were investigated, together with perineurial barrier functioning, in mice infected 20–28 months previously withMycobacterium leprae and in (ageing) non-infected mice. Barriers were tested by i.v. administration of markers (Trypan blue and ferritin) 1–4 days before killing the mice. Twenty-eight months after infection, histopathology of sciatic nerves was comparable to that seen in sensory nerves in clinically early human (borderline-) lepromatous leprosy. Schwann cells and endoneurial macrophages were bacillated, endothelia of endoneurial vessels not, and the perineurium rarely. Many infected mice and all (ageing) controls possessed ultrastructurally and functionally normal endoneurial vessels. Their continuous endothelium with close junctions had prevented marker passage, even when surrounding endoneurial tissue cells were quite heavily bacillated. The perineurium was also normal. By contrast, in infected mice showing hind limb paralysis serious histopathologic involvement and large globi of bacilli intrafascicularly in sciatic nerves, endoneurial blood vessels were abnormal. Open endothelial junctions, extreme attenuation, fenestrations, and luminal protrusions were all features comparable to neural microangiopathy encountered in leprosy patients (Boddingius 1977a, b). The “blood-nerve barrier” clearly had become defective allowing excessive exudation of Trypan blue and ferritin, via four pathways from the vessel lumen, deep into surrounding endoneurial tissues but halted by a normal perineurial barrier. Markers in such “blue” nerves were not found in bacillated or non-bacillated Schwann cells, thus denying significant phagocytotic and lysosomal activities of Schwann cells at this stage of neuropathy. Possible implications of barrier performances for anti-leprosy drug treatment of patients are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690394
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  • 33
    Electronic Resource
    Electronic Resource
    Ultrastructure of the wall of the Dandy-Walker cyst (1984)
    Springer
    Acta neuropathologica 62 (1984), S. 225-229 
    Details
    ISSN: 1432-0533
    Keywords: Dandy-Walker syndrome ; Dandy-Walker cyst ; Ependymal cell ; Ultrastructure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of the wall of the Dandy-Walker cyst has been described rarely. A boy aged 2 years was confirmed clinically, neuroradiologically, and operatively as having a Dandy-Walker cyst in the posterior fossa. The cyst wall obtained during surgery consisted of an outer arachnoid cell layer, intermediate interwoven neuroglial strands, and an inner layer of cells which lacked the characteristic appearance of ependyma. An unusual finding was a small, buried island of ependymal cells in the intermediate layer of the neuroglial tissue. Ultrastructural study of the cyst wall provides a better understanding of the pathogenesis of the Dandy-Walker syndrome.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691856
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  • 34
    Electronic Resource
    Electronic Resource
    Cytoplasmic tubular inclusion in ganglioneuroma (1984)
    Springer
    Acta neuropathologica 64 (1984), S. 81-84 
    Details
    ISSN: 1432-0533
    Keywords: Ganglioneuroma ; Cytoplasmic tubular inclusion ; Smooth endoplasmic reticulum ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Unusual tubular inclusions were observed in the cytoplasm of ganglion cells of a mediastinal ganglioneuroma in a boy of 7 years. The inclusions consisted of an aggregation of about 100-nm-sized tubular structures resembling ‘honeycomb-like’ tubular structures in the axoplasm of rats and mice and suggested to be derived from dilated rough endoplasmic reticulum. These structures differ from profiles reported in normal and pathologic conditions and seem to be related to the neoplastic character of the ganglion cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695612
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  • 35
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    Electronic Resource
    Effect of aeration status of nutrient solution on microorganisms, mucilage and ultrastructure of wheat roots (1984)
    Springer
    Plant and soil 80 (1984), S. 381-390 
    Details
    ISSN: 1573-5036
    Keywords: Aeration status ; Microorganisms ; Mucilage ; Rhizosphere ; Ultrastructure ; Wheat root
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Outer layers of wheat roots grown in aerated and unaerated nutrient solutions were studied by transmission electron microscopy. Root growth was considerably impaired in unaerated nutrient solution. In contrast to aerated roots, no mucilaginous layer but dense bacterial colonization were observed on the root caps of unaerated roots. The root cap mucilage had apparently been decomposed by the microorganisms. The peripheral root cap cells of the unaerated roots appeared to contain less cell organelles than those of the aerated roots, while the central cap cells and the meristematic cells of the root tip seemed not to be affected by lack of aeration. The bacterial population in the elongation, root hair, and lateral root zones, was also remarkably higher on roots grown in unaerated nutrient solution. In the lateral root zone of unaerated roots, even the cortical cells were invaded by bacteria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02140045
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  • 36
    Electronic Resource
    Electronic Resource
    Mycorrhizal improvement in non-leguminous nitrogen fixing associations with particular reference toHippophaë rhamnoides L. (1984)
    Springer
    Plant and soil 78 (1984), S. 189-199 
    Details
    ISSN: 1573-5036
    Keywords: Alnus Hippophaë ; Mycorrhiza ; Myrica ; Nitrogenase ; Phosphate ; Triple symbiosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The roots ofHippophaë rhamnoides which regularly bear actinomycete induced nodules when growing on Scottish sand dunes have also been found to support an endomycorrhizal association withGlomus fasciculatus. Ultrastructural and cytochemical studies carried out on the indigenous infections of establishedHippophaë mycorrhizal roots would support the postulate that transport is indeed occurring between the fungal symbiont and the host plant and vice versa in respect of phosphate and carbohydrate. Experiments using various inoculation regimes, demonstrated the significant improvement in the mycorrhizal/nodulated plants compared to the nodulated-only and the mycorrhizal-only plants with respect to plant growth, uptake of phosphate and nitrogenase activity, when grown in a medium poor in combined nitrogen and soluble phosphate. Preliminary work onAlnus andMyrica species growing in Central Scotland indicates that the mycorrhizae associated with these nodulated root systems exhibit a different interaction pattern which may be dependent on habitat type and associated angiosperm species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02277850
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  • 37
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    Electronic Resource
    Observations on the ultrastructure ofFrankia sp. in root nodules ofDatisca cannabina L. (1984)
    Springer
    Plant and soil 79 (1984), S. 383-402 
    Details
    ISSN: 1573-5036
    Keywords: Actinorhizae ; Datisca cannabina ; Frankia ; Nitrogen fixation ; Root nodules ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The fine structures of the microsymbiont inside the root nodules ofDatisca cannabina have been studied by light, by transmission- and by scanning-electron microscopy. The endophyte is prokaryotic and actinomycetal in nature. The hyphae are septate and branched, diameter 0.3–0.5 μm. The tips of hyphae are swollen to form electron-dense, clubshaped to filamentous vesicles, ranging in diameter: 0.4–1.4 μm. The endophyte penetrates through walls of the cortial cells. The infected zone is kidney shaped and confined to one side of the acentric stele. The orientation of infection is reversed from other actinorhizae exceptCoriaria. The hyphae are near the host cell wall and vesicles are directed towards the central vacuole. Vesicles are aseptate and no collapsing of the vesicle cell wall (void area) has been observed. Vesicle clusters structures are globular with an opening at one side of the cluster. The host cell is multinucleate or contains a lobed nucleus. Groups of mitochondria are located in between the hyphae, suggesting a strong association between the host and the endophyte for energy supply and amino acid production. The consequences of the inability to separate the mitochondria from the vesicle clusters in nodule homogenates in physiological studies have been discussed. Isolated vesicles clusters showed dehydrogenase activity, indicated by the presence of formazan crystals, after incubation with NADH and NBT. Strongest reducing activity was found within the vesicles. The possible role of filamentous vesicles in nitrogen fixation has been discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02184330
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  • 38
    Electronic Resource
    Electronic Resource
    Effect of gossypol on bull spermatozoa in vitro (1984)
    Springer
    Urological research 12 (1984), S. 187-192 
    Details
    ISSN: 1434-0879
    Keywords: Gossypol ; Bull spermatozoa ; Motility ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Gossypol acetic acid in a concentration of 1,000 μg/ml solvent is able to immobilize 1 ml of native bull semen (sperm concentration: 8.5×108/ml; motility rate: 87.4%) within 30 min. After GAA treatment the spermatozoa show severe morphological damage on the membrane system, on the acrosomal complex and on the tubular complex of the end piece. The working mechanism of GAA can be assumed to be inactivation of enzyme activities or in direct reactions with plasma membrane material.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00255921
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  • 39
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    Electronic Resource
    Ultrastructural analysis of human proximal tubules and cortical interstitium in chronic renal disease (Hydronephrosis) (1984)
    Springer
    Virchows Archiv 402 (1984), S. 209-237 
    Details
    ISSN: 1432-2307
    Keywords: Proximal tubule ; Atrophy ; Cortical interstitium ; Human nephropathy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A systematic ultrastructural analysis of proximal tubule atrophy and cortical interstitial changes was carried out in human chronic nephropathy. The investigation was based on human hydronephrotic kidneys, which had been surgically removed and subsequently perfusion-fixed for light and electron microscopy. Normal kidney tissue, which was derived from nephrectomy specimens with pathological changes confined to part of the kidney or to the renal pelvis, was used for control material. A slight degree of proximal tubule atrophy was characterized by reduction of mitochondria and basolateral membranes, enlargement of large endocytic vacuoles and increased numbers of lysosomes containing lamellar material. In moderate atrophy these changes were further accentuated, and in addition there was an increasing loss of microvilli and a reduction of endocytic invaginations and small endocytic vacuoles. In severe atrophy all types of organelles were sparse and the architecture of the tubule cells greatly simplified. A distinctive feature of atrophic tubules was the presence in the tubule cells of large bundles of actin-like filaments, which were often associated with outpouchings of basal cell parts and basement membrane. The reduction of mitochondria and basolateral cell membranes and the changes of endocytic vacuoles and lysosomes indicate that proximal tubule atrophy also in early stages may be associated with impairment of tubular transport processes. Comparisons with previous observations in various types of experimentally induced tubule cell degeneration and with the ultrastructure of regenerating proximal tubule cells provide some evidence that degenerative changes as well as imperfect regeneration of tubule cells may contribute to the alterations of ultrastructure in tubular atrophy. It is suggested that changes of the cortical interstitium may be of pathogenic importance for the progression of tubular atrophy by altering the spatial relationships between tubules and capillaries.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695077
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  • 40
    Electronic Resource
    Electronic Resource
    Atypical germ cells of the testis (1984)
    Springer
    Virchows Archiv 402 (1984), S. 439-450 
    Details
    ISSN: 1432-2307
    Keywords: Atypical germ cells ; Carcinoma in situ of the testis ; Normal germ cells ; Ultrastructure ; Differential diagnosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary It is uncertain whether the so called intratubular atypical germ cells (carcinoma in situ cells) demonstrable in the testicular tissue around different germ cell tumors and in testicular biopsies of patients with impaired fertility are identical with regard to their morphology and further development. Thus atypical germ cells of 18 patients with testicular germ cell tumors and of 3 patients with atypical germ cells in testicular biopsies without tumor were studied by electron microscopy and/or by immunohistochemistry. The atypical germ cells show characteristic alterations distinguishing them from normal germ cells, especially spermatogonia. However, there are no differences between atypical germ cells in the above mentioned groups. Immunohistochemical reactions are negative with anti-alpha-fetoprotein and anti-beta-human-chorionic-gonadotropin, but 6 of the 15 cases are positive with antiferritin. However, this positive reaction occurs in cases in different diagnostic groups. Atypical germ cells of the different groups cannot be distinguished by electron microscopy or immunohistochemical methods, but further investigations vestigations, including cell cultures, may provide more information.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00734640
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  • 41
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    Electronic Resource
    Ultrastructural aspects of the histogenesis of diffuse and localized mesothelioma (1984)
    Springer
    Virchows Archiv 402 (1984), S. 373-388 
    Details
    ISSN: 1432-2307
    Keywords: Mesothelioma ; Histogenesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary During an ultrastructural review of 30 diffuse and 10 localized mesotheliomas, it was apparent that some micrographs showed various stages in the developmental processes involved in the formation of histological patterns in diffuse mesotheliomas and a histogenetic link between diffuse and localized mesotheliomas. Cells in the stromal or sarcomatous regions of diffuse mesothelioma often show varying degrees of mesothelial differentiation and a gradual transition to cells with typical mesothelial characteristics that organize into structures recapitulating the surface layer of serosal membranes. Tumor cells in localized mesotheliomas had many similarities to the “stromal” cells in the diffuse counterpart including intercellular junctions, rare microvilli and occasional foci of basal lamina. It is postulated that diffuse and localized mesotheliomas share a common histogenetic origin as a result of neoplastic induction of specialized submesothelial cells. In this concept, tumor cells in diffuse mesotheliomas reflect stages in the differentiation and organization of normal serosal membranes and localized mesotheliomas mirror the earliest phases of this process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00734635
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  • 42
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    Electronic Resource
    Unequal distribution of plastids during generative cell formation in Impatiens (1984)
    Springer
    Theoretical and applied genetics 68 (1984), S. 305-309 
    Details
    ISSN: 1432-2242
    Keywords: Impatiens ; Microspore mitosis ; Plastid distribution ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This paper describes the unequal distribution of plastids in the developing microspores of Impatiens walleriana and Impatiens glandulifera which leads to the exclusion of plastids from the generative cell. During the development from young microspore to the onset of mitosis a change in the organization of the cytoplasm and distribution of organelles is gradually established. This includes the formation of vacuoles at the poles of the elongate-shaped microspores, the movement of the nucleus to a position near the microspore wall in the central part of the cell, and the accumulation of the plastids to a position near the wall at the opposite side of the cell. In Impatiens walleriana, the accumulated plastids are separated from each other by ER cisterns, and some mitochondria are also accumulated. In both Impatiens species, the portion of the microspore in which the generative cell will be formed is completely devoid of plastids at the time mitosis starts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00267882
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  • 43
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    Esthesioneuroblastoma: Ultrastructural, immunohistological and biochemical investigation of one case (1984)
    Springer
    European archives of oto-rhino-laryngology and head & neck 239 (1984), S. 133-144 
    Details
    ISSN: 1434-4726
    Keywords: Esthesioneuroblastoma ; Intermediate filaments ; Secretory granules ; Ultrastructure ; Immunohistology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of esthesioneuroblastoma, the pathological diagnosis of which almost always causes great difficulties, was investigated ultrastructurally, biochemically, and immunohistologically, using antibodies against the five known types of intermediate filaments [keratin, vimentin, desmin, glial fibrillary acidic protein (GFAP) and neurofilaments]. The tumour cells did not react with antibodies against any of the five intermediate filament proteins. Ultrastructural investigations showed dense cored secretory granules in the cytoplasm and cell processes. Thus, immunohistology offers by “exclusion” a differential diagnosis to avoid often misdiagnosed tumours (undifferentiated carcinomas, embryonal rhabdomyosarcomas, and malignant lymphomas), since carcinomas react with antikeratin, embryonal rhabdomyosarcomas with antibodies to desmin and malignant lymphomas show immunofluorescence with antibodies to vimentin. The biological behaviour (age distribution, tendency to metastasize), the normal values of biochemical parameters, homovanillic acid and vanilmandelic acid (HVA, VMA), and the absence of neurofilaments distinguish this type of tumour from the peripheral sympathetic neuroblastoma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00463554
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  • 44
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    Electronic Resource
    The taxonomic significance of the mitotic spindle and nucleus-associated organelle ofEntomophaga aulicae (1984)
    Springer
    Protoplasma 120 (1984), S. 84-90 
    Details
    ISSN: 1615-6102
    Keywords: Entomophaga aulicae ; Fungi ; Mitosis ; Nucleus associated organelle ; Taxonomy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Nuclei in protoplasts ofEntomophaga aulicae contain abundant condensed chromatin and a large central nucleolus. The metaphase spindle occupies a small eccentric area of the nucleus while the remainder of the nucleus is filled with condensed chromatin. Small portions of condensed chromatin are aligned along a broad metaphase plate and connected to the spindle poles by kinetochore microtubules. The nucleus associated organelle (NAO) is a solid barlike structure which lies at the spindle poles and is closely associated with the outer membrane of the nuclear envelope. Comparison of the nuclear characteristics ofE. aulicae with those of other members of theEntomophthorales supports the separation of theEntomophthoraceae from theBasidiobolaceae andAncylistaceae. Further comparison of details of nuclear division in theEntomophthoraceae, specifically NAO morphology, may be useful in helping to delineate evolutionary lines within the family.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01287620
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  • 45
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    Electronic Resource
    The occurrence of calyx nodules inPsychotria spp. (Rubiaceae) (1984)
    Springer
    Protoplasma 121 (1984), S. 199-208 
    Details
    ISSN: 1615-6102
    Keywords: Psychotria ; Leaf nodules ; Calyx nodules ; Symbiosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The occurrence and structure of calyx nodules in the flowers of two leaf nodulated rubiaceous speciesPsychotria punctata Vatke andPsychotria kirkii Hiern. has been described for the first time at the ultrastructural level. Bacteria, resident in colleter-secreted mucilage in the space between calyx and corolla, invade stomatal pores which develop on the calyx protoderm. The bacteria proliferate in the substomatal cavity and then invade the calyx mesophyll. This invasion is most pronounced inP. punctata where the bacteria even penetrate and enter the cells of the vascular tissue. Although no sheath forms around the calyx nodules, the calyx mesophyll cells surrounded by the bacteria become identical in shape, size and secretory function to the invasive mesophyll cells of leaf nodules. The functional and evolutionary significance of calyx nodulation is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01282313
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  • 46
    Electronic Resource
    Electronic Resource
    Muscle fibre type characteristics in endurance trained and untrained individuals (1984)
    Springer
    European journal of applied physiology 52 (1984), S. 266-271 
    Details
    ISSN: 1439-6327
    Keywords: Human ; Endurance exercise ; Muscles ; Fibre types ; Histocytochemistry ; Ultrastructure ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The main fibre types ofM. vastus lateralis of 10 trained or untrained male individuals (25–35 years) were quantitatively determined by morphological techniques; the fibre types being defined according to the M-band appearance. The volume density of mitochondria (Vmit) was higher in endurance-trained muscles.Vmit was higher in Type 1 than in Type 2 fibres, there being no difference between subtypes of Type 2 fibres. The volume density of lipid droplets (Vli) showed a wide range of values both with respect to degree of training and between fibre types. Z-band width was not influenced by endurance training, but was considerably larger in Type 1 than in Type 2 fibres. Discriminant analysis showed that 46% of the fibres, preclassified according to the M-band appearance, would have been correctly allocated on basis of theVmit. The corresponding value for lipid droplets was 42% and for the Z-band width, 62%. It is concluded thatVmit is not a satisfactory criterion for discriminating between fibre types, especially between Type 2A and Type 2B in trained subjects. The study also shows that endurance training reduces the relative importance of individual-dependent factors in comparison with muscle fibre properties when concerningVmit.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01015207
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  • 47
    Electronic Resource
    Electronic Resource
    The behavior of the plasma membrane following osmotic contraction of isolated protoplasts: Implications in freezing injury (1984)
    Springer
    Protoplasma 123 (1984), S. 83-94 
    Details
    ISSN: 1615-6102
    Keywords: Freeze-fracture ; Isolated rye protoplasts ; Osmotic contraction ; Plasma membrane-derived vesicles ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Following osmotic contraction of isolated rye protoplast (Secale cereale L. cv. Puma) that results in nearly a 50% reduction in volume, the plasma membrane was smooth, with no folding or pleating. Instead, deletion of plasma membrane occurred and numerous cytoplasmic vesicles were observed. As a result, the area of the plasma membrane was reduced by approximately 40%. Thin sections revealed that the cytoplasmic vesicles were membrane bound and not merely voids in the cytoplasm. High resolution video microscopy revealed the extent of vesiculation showing large clusters of cytoplasmic vesicles following osmotic contraction. Labeling the plasma membrane with fluorescein-Con-A prior to hypertonic contraction suggested that the cytoplasmic vesicles were derived from the plasma membrane. Freeze-fracture particle density on both the protoplasmic (PFp) and exoplasmic face (EFp) of the plasma membrane remained unchanged following contraction, which is consistent with a unit-membrane deletion into cytoplasmic vesicles. Upon partial re-expansion of the protoplasts, thin sections showed that the vesicles remained in the cytoplasm. These results using osmotic manipulation confirm earlier observations of isolated protoplasts at the light microscope level. Upon contraction plasma membrane is deleted into cytoplasmic vesicles, which are not readily reincorporated into the plasma membrane upon expansion. Lysis occurs before the original volume and surface area are regained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01283579
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  • 48
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    Electronic Resource
    Etioplast-chloroplast transformation in maize leaves: Effects of tissue age and light intensity (1984)
    Springer
    Protoplasma 119 (1984), S. 110-120 
    Details
    ISSN: 1615-6102
    Keywords: Plastid greening ; Zea mays ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effects of light intensity and cell age on the greening of etioplasts were studied in seedlings of maize. We could see that in the youngest tissues examined by us the etioplast greening is very fast and occurs according to a particular pattern which is characterized by the contemporary presence of grana and large non crystalline prolamellar bodies. On the contrary, in the oldest examined tissues the etioplast greening is slow and the formation of grana appears to be delayed and subsequent to the using up of the prolamellar bodies. In the young tissues the intensity of the light mainly affects the duration of the lag-phase preceding the chlorophyll accumulation, while in the old tissues it also affects the total amount of chlorophyllous pigments, the restraining effect of the light appearing amplified by a concomitant restraining effect of cell age.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01287823
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  • 49
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    Electronic Resource
    Ultrastructure and behaviour of the spindle pole body of the aphid-pathogenic fungusErynia neoaphidis (1984)
    Springer
    Protoplasma 120 (1984), S. 61-71 
    Details
    ISSN: 1615-6102
    Keywords: Fungus ; Spindle pole body ; Entomophthoraceae ; Erynia neoaphidis ; Ultrastructure ; Replication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A detailed account of the ultrastructure and behaviour of the spindle pole body (SPB) of the entomophthoraceous fungusErynia neoaphidis is presented for the first time. The SPB consists of extranuclear (ENC) and intranuclear (INC) components. The ENC is a “saucepan-shaped” structure which lies in a pocket of the nuclear envelope. It is composed of a forked, fibrillar “handle” and a shallow, cylindrical “pan”. The “pan” has a wall of two layers, both of which are thickened with a regular periodicity so that they appear to be “beaded”. It is postulated that the “pan“ is formed from rough endoplasmic reticulum and that it synthesizes the amorphous, electron-dense material coating the ENC. The INC is a “saucer-shaped”, electron-dense plaque in which the ends of the spindle microtubules terminate. During metaphase, a “clear zone” separates the INC from the nuclear envelope and persists until telophase. The roles of the amorphous, electron-dense material and the “clear zone” as well as the method of SPB replication are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01287618
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  • 50
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    Electronic Resource
    Ultrastructure of mitosis in the aphid-pathogenic fungusErynia neoaphidis (1984)
    Springer
    Protoplasma 120 (1984), S. 72-83 
    Details
    ISSN: 1615-6102
    Keywords: Fungus ; Mitosis ; Entomophthoraceae ; Erynia neoaphidis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary An account of mitosis in the aphid-pathogenic, entomophthoraceous fungusErynia neoaphidis is presented. The mitotic apparatus is characterized by a closed, intranuclear, polarized spindle. Chromosomes are permanently attached by kinetochore microtubules (kcMTs) to the poles during mitosis. The spindle develops as the spindle pole bodies migrate and separate. At metaphase the eccentric spindle contains only kcMTs and is located in a relatively chromatinfree zone. Paired sister kinetochores are arranged in a broad metaphase plate. During anaphase kcMTs shorten, astral and nonchromosomal microtubules develop and elongate and the interpolar distance increases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01287619
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  • 51
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    Electronic Resource
    Gametogenesis inCoelomomyces dodgei Couch (Blastocladiales, Chytridiomycetes) (1984)
    Springer
    Protoplasma 121 (1984), S. 65-76 
    Details
    ISSN: 1615-6102
    Keywords: Blastocladiales ; Chytridiomycetes ; Coelomomyces ; Cytoplasmic cleavage ; Gametogenesis ; Mosquito-copepodpathogen ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructure of gametogenesis was studied inCoelomomyces dodgei Couch (Blastocladiales, Chytridiomycetes), an obligate parasite of anopheline mosquito larvae and the copepod,Acanthocyclops vernalis. In infected copepods reared under a 16/8 hours light/dark photoperiod at 25 +2 °C., the gametophyte develops over a period of approximately seven days, and gametogenesis is triggered by the onset of the dark period during the last day of development. The initial step of gametogenesis is the elongation of the centriole to form the kinetosome, and measuring time from the onset of the final dark period (0 hours), this occurs prior to the beginning of the light period (8 hours). Subsequently, small vesicles that appear to originate from elements of the rough endoplasmic reticulum (rER) fuse at the distal end of the kinetosome forming the flagellar vesicle into which the axonemal microtubules elongate to form the flagellum (8–12 hours). Similar small vesicles apparently also derived from rER align in planes and fuse to form cleavage furrows which delineate the gamete initials (12–14 hours). As the gamete initials begin forming, the mitochondria within each initial fuse to form a single mitochondrion that associates with the lipid globules and microbodies forming the microbody-lipid globule complex (12–16 hours). The time elapsed between the formation of the flagellar vesicle to the release of mature gametes from the copepod host is about 8.5 hours. No differences were observed in the processes or timing of gametogenesis in male and female gametophytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01279753
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  • 52
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    Electronic Resource
    The spatial organization of nucleolar DNA in phytohemagglutinin-stimulated lymphocytes of the guinea pig (1984)
    Springer
    Cell & tissue research 235 (1984), S. 65-70 
    Details
    ISSN: 1432-0878
    Keywords: Lymphocytes ; Phytohemagglutinin stimulation ; Nucleolar organizer region ; Three-dimensional reconstruction ; Ultrastructure ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructural changes in the spatial organization of nucleolar DNA in lymphocytes during phytohemagglutinin (PHA) stimulation was studied in guinea pigs by means of oxidized diaminobenzidine (DAB) at low pH as a differentially contrasting stain for nucleic acids and by the use of reconstruction of serial sections. The extended DNA filaments situated inside the fibrillar area originate from a large aggregation of heterochromatin, which is closely associated with the nucleolus, and from the perinucleolar shell of condensed chromatin. It is suggested that these two distinct regions of chromatin might be associated with different functions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213724
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  • 53
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    Electronic Resource
    Diurnal variations in myeloid bodies of the newt retinal pigment epithelium (1984)
    Springer
    Cell & tissue research 235 (1984), S. 177-186 
    Details
    ISSN: 1432-0878
    Keywords: Retinal pigment epithelium ; Myeloid bodies ; Diurnal variation ; Morphometrics ; Ultrastructure ; Lipid metabolism ; Endoplasmic reticulum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Myeloid bodies (MBs) occur in the newt (Notophthalmus viridescens) retinal pigment epithelium (RPE) and are similar to areas of specialized endoplasmic reticulum found in a variety of other cell types. The function of these structures is unknown, although a role in lipid metabolism has been strongly suggested. Random samples from conventionally-fixed and sectioned newt RPE, obtained over a 24-hr cycle (LD 12∶12), were examined by electron microscopy. Myeloid bodies appear as stacks of flattened endoplasmic reticulum-associated saccules which increase in length and number as the RPE accumulates shed outer segment material, prior to increase in the amount of stored lipid. Associations of MBs with the nuclear envelope can be related to this increased length. Myeloid bodies decrease numerically in the cell as phagosomes are removed from the cytoplasm, but a decrease in mean sectional MB area, seen in the light phase, is counteracted in darkness where individual MBs are larger than those found in the light. The total sectional area of MBs within a cell and their mean length varied depending on the lighting condition; differences were also found between eyes after extended periods of continuous light and dark. Ribosomes were found in association with the surfaces of both flattened and circular MBs, but they were consistently more densely associated with the shorter concave surfaces of curved regions. A new hypothesis for MB function is presented, which is concerned with their role in isolating toxic lipids such as retinoids, which are accumulated during phagocytosis of shed outer segment tips, and which are capable of disrupting membrane-bound systems necessary for their eventual metabolism and safe storage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213738
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  • 54
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    Electronic Resource
    Fine structure of submandibular glands of mice with testicular feminization (Tfm/Y) (1984)
    Springer
    Cell & tissue research 235 (1984), S. 295-301 
    Details
    ISSN: 1432-0878
    Keywords: Tfm/Y mouse ; Submandibular gland ; Sexual ; dimorphism ; Androgens ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the submandibular gland of the mouse with testicular feminization (Tfm/Y) was studied by light and electron microscopy. The architecture of the Tfm/Y gland proved to be rather similar to that of the normal female mouse in both tubular ratio and structure. Granular convoluted tubular cells in Tfm/Y mice characteristically had fewer secretory granules and increased cytoplasmic vacuoles than normal littermates, suggesting an altered synthesis of secretory granules in this cell type of the Tfm/Y mouse. Moreover, there were differences in the ultrastructure of submandibular glands between Tfm/Y and normal female mice. In the gland of the Tfm/Y mouse, basal striations of the striated secretory tubular cells were not so developed and granular intercalated duct cells were less than those of normal females. These findings support the evidence that the secretory tubule of the mouse submandibular gland responds to androgens, resulting in accentuated development in the male, while also suggesting the possibility that the mouse submandibular gland is regulated by other factors which lead to the prominent sexual dimorphism observed in this gland.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217853
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  • 55
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    Degenerative regression of the digestive tract in the colonial ascidian Botryllus schlossen (Pallas) (1984)
    Springer
    Cell & tissue research 235 (1984), S. 309-318 
    Details
    ISSN: 1432-0878
    Keywords: Ascidian ; Gut ; Cell involution ; Ultrastructure ; Phagocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Degenerative changes in the digestive tract of zooids of Botryllus schlosseri were studied by light and electron microscopy. Three main processes occurred in the tissues: contraction, involution and phagocytosis. The contraction of epidermis and peribranchial epithelium in which cytoplasmic microfilaments probably participate, seemed to have a special role in compressing the underlying organs. During contraction most of the body cavities collapsed, the branchial walls disintegrated and the fragments were rapidly taken up by large phagocytes. The gut epithelium retained its apparent continuity longer, though isolated phagocytes infiltrated it to eliminate single cells. Cell degeneration came about chiefly either through swelling and lysis of cells or through loss of water and condensation of cytoplasm and nucleus. The fate of all regressed tissues was to be engulfed and digested by wandering phagocytes. However, it was also observed that numerous cells of different epithelia could act as fixed phagocytes by engulfing cell debris and entire cells into heterophagic vacuoles.
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    URL: http://dx.doi.org/10.1007/BF00217855
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  • 56
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    Electronic Resource
    The pig blastocyst: Its ultrastructure and the uptake of protein macromolecules (1984)
    Springer
    Cell & tissue research 235 (1984), S. 347-356 
    Details
    ISSN: 1432-0878
    Keywords: Blastocyst ; Ultrastructure ; Pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Between days 8 and 11 of pregnancy spherical blastocysts from 0.3 to 10 mm in diameter were flushed from the uterine horns of Dutch Landrace pigs. A description of their ultrastructure is given, and the uptake of horseradish peroxidase and ferritin is demonstrated. The ultrastructure of the trophoblast was similar at all ages studied. The trophoblast which has many apical microvilli is able to take up and digest the macromolecules which were offered in the in vitro incubation medium. The hypoblast consists of flattened cells. In blastocysts 2 mm and larger, compact cells bearing microvilli are found below the embryoblast. Cell organelles indicating protein synthesis are found within hypoblast cells of such blastocysts. In the embryoblast, local concentrations of cell organelles are visible, indicating that differentiation has started. After the disappearance of Rauber's layer, which takes place when the blastocyst reaches a diameter of about 2 mm, superficial embryoblast cells develop short microvilli. The cells do not absorb ferritin or peroxidase but are dependent on the trophoblast for their food requirements. All cell layers in the blastocyst contain mitochondria that have characteristics of those found in steroidproducing cells. The significance of the uptake and digestion of macromolecules by trophoblast cells, the synthesis of protein by hypoblast cells and the possible synthesis of steroids is discussed with respect to the relationship between the cell layers of the blastocyst and in the context of conceptomaternal relationships.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217859
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  • 57
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    Electronic Resource
    The ecdysis of hair mechanoreceptors in crayfish (1984)
    Springer
    Cell & tissue research 236 (1984), S. 339-343 
    Details
    ISSN: 1432-0878
    Keywords: Moulting ; Mechanosensory hair ; Chordotonal organ ; Ultrastructure ; Crustacea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of hair mechanoreceptors in crayfish during moulting was investigated with special attention to the interface apparatus between cuticular hairs and sensory cells: the chorda. The chordae are lost with old exuviae at every moulting. They are drawn out from a moulting canal at the tip of the new hair. The chordae are regenerated from a material secreted by sheath cells after moulting. Therefore, the chorda is an inward projection of the cuticular exoskeleton, and it has direct contact with the sensory element, the scolopidium. The scolopidium has been found in both hair mechanoreceptors and subcuticular chordotonal organs in crustaceans, and is thought to be a primitive type of mechano-sensory transducing element. The present observation gives additional evidence for the homology of two sensory elements in arthropods, i.e., the cuticular hair sensilla and subcuticular chordotonal organs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214236
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  • 58
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    Electronic Resource
    Grundlagen der Werkstoffauswahl bei der Bekämpfung des Strahlverschleißes (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 49-58 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Fundamentals of Material Selection in the Conditions of Erosive WearProblems of proper selection of materials for parts subjected to wear by a stream of abrasive particles are discussed. Considering the main laws governing such kind of wear, the author concludes that target material selection in the case of erosion, like in any other case of abrasive wear, will depend on the ratio of abrasive grain hardness to material hardness. Special attention should be given to hard components in the abrasive. It has been established that a 10-15% content of quartz particles in the abrasive is enough to cause an abrupt fall in the wear resistance of chilled steels, white iron and hard surfacing alloys, thus making their use questionable. Finegrained WC-Co-type sintered carbides have shown the highest wear resistance in such conditions.The conclusions drawn in this paper are borne cut by a considerable body of experimental data.
    Notes: In dem Artikel werden Probleme der zweckmäßigen Werkstoffauswahl bei der Strahlverschleißbekämpfung behandelt, die allgemeinen Gesetzmäßigkeiten deser Verschleißart dargelegt und gezeigt, daß analog zu anderen Abrasivverschleißarten auch in diesem Fall die Materialauswahl durch einen Vergleich von Werkstoff- und Schleifkornhärte erleichtert wird. Besondere Aufmerksamkeit gilt dem Einfluß von Zusätzen harter Körner in Strahlmittel. Schon ein etwa 10-15prozentiger Anteil von Quarzteilchen ruft eine jähe Senkung des relativen Verschleißwiderstandes bei gehärteten Stählen, Hartguß und Auftragsschweißwiderstandes bei gehärteten Stählen, Hartguß und Auftragsschweißungen hervor und macht deren Anwendung problematisch. Den größten Verschleißwiderstand unter solchen Bedingungen haben feinkörniger WC-Co-Sinterhartmetalle.Die Schlußfolgerungen werden durch umfangreiche Versuchsergebnisse belegt.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150204
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    Ein Beitrag zum Abbrandverhalten von hochlegierten Drahtelektroden (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 95-96 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: A Study on Alloy Element Loss in MIG Welding of Stainless SteelsAAS-analysis of welding fume yields information about alloy element loss in MIG welding of stainless steels. Welding under shielding gases short of oxygen, the heavy metal loss can be correlated with the element's partial pressures in the welding wire alloy.
    Notes: Durch Analyse des Schweißrauches läßt sich Aufschluß über das Abbrandverhalten von Drahtelektroden gewinnen. Beim MAG-Schweißen unter sauerstoffarmen Schutzgasen wird der Schwermetall-Abbrand durch die Partialdrucke der Legierungskomponenten kontrolliert.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150305
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    Fraunhofer-Institut für Betriebsfestigkeit (LBF) (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 102-107 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150307
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    Elektrische Kontakte und ihre Werkstoffe. Von A. Keil, W. A. Merl und E. Vinaricky. 1. Auflage, Springer-Verlag Berlin/Heidelberg/New York/Tokyo. 1984, 496 Seiten, 431 Bilder, zahlreiche Tabellen, gebund., 290,- DM (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 108-108 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150310
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  • 62
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    Einfluß der Probengröße auf die bruchmechanischen Eigenschaften von Sinterstahl (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 109-117 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Influence of Specimen Size on the Fracture Mechanical Behaviour of Sintered SteelFracture mechanics testing was carried out with small and big specimens using high-temperature sintered Fe-2%Cu-2.5%Ni-alloys in the densities of ρ = 7.1 and 7.4 g/cm3. These steels are often used in the manufacturing of PM-parts. Due to the different dismensions the crack propagation is for the bigger sizes faster than for the smaller sizes. Also the conditional fracture toughness of the big specimens is superiour to the toughness of the small specimens. But under consideration of a plain strain state for the big specimens and of a plain stress state for the small specimens valid fracture toughness values being independent from the specimen size can be calculated applying linear-elastic fracture mechanics.These results were obtained for both densities investigated. The increase of the density delivers principally better fracture mechanical data. Hereby the relation of strength data with the microstructure is also discussed.
    Notes: Am Beispiel von in der Formteilherstellung häufig verwendeten hochtemperaturgesinterten Fe-2%Cu-2,5%Ni-Legierungen in den Dichten ρ = 7,1 und 7,4 g/cm3 wurden bruchmechanische Untersuchungen an Klein- und Großproben vorgenommen. Aufgrund der unterschiedlichen Abmessungen ergibt sich bei Großproben eine größere Rißfortschrittsgeschwindigkeit und eine größere vorläufige Bruchzähigkeit als bei den Kleinproben. Durch Zuordnung des ebenen Dehnungszustandes zu den Großproben und des ebenen Spannungszustandes zu den Kleinproben läßt sich jedoch unter Berücksichtigung der jeweiligen plastischen Zonen ein von der Probenform unabhängiger gültiger Bruchzähigkeitswert auf der Basis der linear-elastischen Bruchmechanik berechnen.Diese Ergebnisse gelten für beide Dichtevarianten, wobei die Erhöhung der Dichte die bruchmechanischen Kennwerte grundsätzlich verbessert. Hierbei wird auch auf den Zusammenhang zwischen den Festigkeitskennwerten und dem Gefüge eingegangen.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150402
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    Nachrichten - Hinweise (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. A35 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150408
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  • 64
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    Berührungslose Prüfung von Kunststoffen mittels photothermischer Wärmewellenanalyse (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 140-148 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Remote Testing of Polymers with Photothermal Analysis of Thermal WavesAfter an introduction to thermal waves a comparison is made of photoacoustic detection methods (gas cell, piezoceramic) and photothermal detection arrangements (front surface and rear surface methods). Previously only photoacoustic methods have been applied to polymer related problems, while the advantages of photothermal measurements - remote and nondestructive evaluation - have been demonstrated on metals. The experimental part of this paper presents first steps to apply photothermal analysis of thermal waves to some problems of polymers: thickness measurement of thin layers; on-surface and subsurface defects; delamination of bonding and coating curing reactions; glass fibre content; orientation of fibres and molecules; aging processes.The present results indicate that the method can be used for nondestructive remote quality assurance of thin layers and foils. Further development is required to apply the method to nondestructive testing of thick walled components.
    Notes: Nach einer Einführung in die Grundlagen von Wärmewellen werden die photoakustischen Meßmethoden (Gaszelle, Piezokeramik) den photothermischen Meßmöglichkeiten (Frontseiten- und Rückseitenmethode) erläuternd gegenübergestellt. Kunststoffbezogene Problemstellungen wurden bisher nahezu ausschließlich mit photoakustischen Methoden bearbeitet. Die Vorteile der photothermischen Messungen - berührungslose und zerstörungsfreie Prüfung - konnten bisher an Metallen verdeutlicht werden. Der experimentelle Teil dieser Arbeit zeigt in ersten Schritten auf, daß auch bei Kunststoffen folgende Problemstellungen mit der Methode der photothermischen Wärmewellenanalyse bearbeitet werden können.Dickenmessung dünner Schichten; äußere und innere Fehlstellen; Haftungsfehler bei Verklebungen oder Beschichtungen; Vernetzungsreaktionen; Glasfaseranteil; Glasfaser- und Molekülorientierungen; Alterungsvorgänge.Die bisherigen Ergebnisse lassen sich in die zerstörungsfreie Qualitätssicherung dünner Schichten und Folien übertragen. Die zerstörungsfreie Prüfung von dickwandigen Bauteilen bedarf einer methodischen Weiterentwicklung.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150406
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    Nachrichten - Hinweise (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. A101 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840151210
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    Two-Stage Tempering of steel 13%Cr6%Ni (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 411-415 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Steel of the type 13%Cr6%Ni modified with 0.56%Mo allows to achieve favourable mechanical metallurgy properties, including decrease of the susceptibility to temper embrittlement. Application of two-stage tempering (first at 625°C, second at 575-600 °C) leads to counterbalanced mechanical properties and to the improvement of corrosion resistance in dependence on the modification of structure.The physical metallurgy characteristics were completed by potentiodynamic measurements. It was found that this evaluation indicates very sensitively the formation of austenite in the structure after applying tempering at intercritical temperatures. A model of austenite stabilization using the single and two-stage tempering method is presented.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840151203
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    Die galvanische Vernicklung. Von R. Brugger. 2. Auflage 1984.790151207 G. Lenze-Verlag, 7968 Saulgau/Württ., 445 Seiten, 165 Bilder, zahlreiche Tabellen, gebunden 78,- DM (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 436-436 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840151207
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    Nachrichten - Hinweise (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. A2 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150107
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    Masthead (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984) 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150201
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    Glatt- und Festwalzen an PKW Fahrgestell- und AntriebsbauteilenVortag gehalten anläßlich der DVM-Veranstaltung 8. Sitzung des Ak-Betriebsfestigkeit am 12./13. 10. 82 in München. (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 41-45 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Finsh and Solid Rolling of Automotive Running Gear and Drive ComponentsAutomotive parts, in particular running gear and drive components, are subject to high dynamic loads in regards to strength.When designing new parts, this is taken into account through dimensioning, material selection and constructional conception. Normally the mentioned measures will not be applied to old designs if, for example, they are subjected later to higher loads because of an increase in engine power output. Only the selection of different materials as well as strength increasing measures and methods remain for these parts.An important method is solid rolling. The examples of completed designs demonstrate the possible strength improvements, influence of rolling force on component strength as well as desired and undesired accompaniments.A comparison is made between solid rolling and other strength improving measures, such as inductive hardening.The results show the solid rolling method to be cost-favorable, very effective and safe in handling. The method has its limits in geometry (open rotation-symmetrical cross sections are required), size (component too large, cross section too filigreed) and application range (temperature) of components.
    Notes: Kraftfahrzeug-Bauteile, insbesondere Fahrwerkskomponenten und Antriebsbauelemente sind festigkeitsmäßig dynamisch hoch beansprucht.Bei der Neukonstruktion wird dem durch Dimension, Werkstoffauswahl und Konstruktionsprinzip Rechnung getragen. An bestehenden Konstruktionen, wenn diese beispielsweise durch spätere Leistungssteigerung höher belastet werden, scheiden in der Regel die genannten Maßnahmen aus. Hier bleiben dann neben anderer Werkstoffwahl nur festigkeitssteigernde Maßnahmen und Verfahren.Als ein bedeutendes Verfahren steht hier das Festwalzen. Die Beispiele ausgeführter Konstruktionen zeigen die möglichen Festigkeitssteigerungen, den Einfluß der Walzkräfte auf die Bauteilfestigkeit sowie erwünschte und unerwünschte Begleiterscheinungen.Es wird verglichen zwischen Festwalzen und anderen Maßnahmen zur Festigkeitssteigerung wie Induktivhärten.Das Ergebnis zeigt das Festwalzverfahren als kostengünstig, sehr wirksam und sicher in der Handhabung. Grenzen liegen verfahrensbedingt in der Geometrie (offene rotationssymmetrische Querschnitte notwendig), Dimension (Bauteil zu groß, Querschnitt zu filigran) und im Einsatzbereich (Temperatur) der Bauteile.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150202
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    Aktivierungsenthalpien und Mechanismen der unterkritischen Rißausbreitung in Aluminiumoxidkeramiken (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 65-72 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Activation Enthalpies and Mechanisms of Subcritical Crack Propagation in Aluminium Oxide CeramicsProgressive crack propagation has been investigated in the temperature range between 25 and 1000°C for two commercial varieties of Al2O3 ceramic, using double torsion specimens. 3 different temperature regions have been found, each of them with a different dependence of the effective activation enthalpie on the stress intensity factor. While at low temperatures the crack propagation rate is mainly controlled by the reaction of the grain boundary phase with the water vapor partial pressure of the environment, the softening of this phase is the predominent factor at high temperatures.
    Notes: An zwei Qualitäten kommerzieller Al2O3-Keramik unterschiedlichen SiO2-Gehalts wurde an Doppeltorsionsproben die langsame Rißausbreitung im Temperatubereich von 25 bis 1000°C untersucht. Es wurden drei Bereiche gefunden, die eine unterschiedliche Abhängigkeit der effektiven Aktivierungsenthalpien vom Spannungsintensitätsfaktor aufweisen. Bei niedrigen Temperaturen steuert im wesentlichen die Reaktion des Wasserdampfes der umgebenden Luft mit der Korngrenzenphase die Rißausbreitung, bei hohen Temperaturen spielt die Erweichung dieser Korngrenzenphase die entscheidende Rolle.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150206
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    Die Zähigkeit metallischer Diffusionsschutzschichten auf Nickellegierungen und ihre KennzeichnungEin Teil der diesem Bericht zugrunde liegenden Arbeiten wurde mit Mitteln des Bundesministers für Forschung und Technologie unter dem Kennzeichen 01 ZB 157-D 20 gefördert. (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 73-82 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Ductility of Metallic Diffusion Type Coatings on Nickel-Based Alloys and its DeterminationA test method is being presented by which ductility properties of metallic diffusion coatings, which are used against hot corrosion e.g. on turbine blades, can be measured. The ductility measurements are based upon the acoustic emission during crack initiation within coated specimens under mechanical load. By plotting the acoustic emission and the stress vs. elongation simultaneously, the crack initiation stress vs. elongation simultaneously, the crack initiation stress of the coating and the 0,2%-proof stress of the substrate can be determined by the same experiment. Correlations between these two stress levels led to ductility characteristics and within the scope of these investigations to dependences on temperature, coating thickness, strain rate and thermal history of the coating/substrate system. The investigations were carried out on three different diffusion coatings combined with two nickel-base superalloys. Ductility measurements up to 850°C led to ductile-brittle-transition-temperatures as well as to temperature dependant stress and strain levels, below which the coatings on certain substrate behave in a ductile manner.
    Notes: Diffusionsschutzschichten gegen Heißgaskorrosion sind vielfach bei niedrigen Temperaturen spröde und werden erst bei höheren Temperaturen zäh. Für das Betriebsverhalten beschichteter Turbinenschaufeln z. B. ist die Kenntnis der Übergangstemperatur vom spröden zum zähen Verhalten von Bedeutung, wobei die Eigenschaften der Schutzschicht vom jeweiligen Trägerwerkstoff beeinflußt werden. - Es wird nun ein Prüfverfahren vorgestellt, mit dem an beschichteten Proben unter mechanischer Beanspruchung das Auftreten erster Anrisse in der Schutzschicht durch Schallemissionsmessungen nachgewiesen und gleichzeitig durch die Aufnahme eines Spannung-Dehnung-Schaubildes die relative Lage der Anrißspannung der Schutzschicht und der 0,2 Grenze des Trägerwerkstoffes erfaßt werden. Aus den durchgeführten Versuchen ließen sich Angaben über die Zähigkeit in Abhängigkeit von der Temperatur und anderen Einflußgrößen wie Schichtdicke, Dehngeschwindigkeit und thermischer Vorgeschichte ableiten. Auf diese Weise konnten für drei verschiedene Schutzschichten, dei mit zwei hochwarmfesten Nickellegierungen kombiniert waren, Spröde Zäh-Übergangstemperaturen bestimmt werden. Weiterhin ergaben sich bis zur höchsten Prüftemperatur von 850°C Spannungs- und Dehnungsgrenzen, unterhalb derer die untersuchten Schutzschichten auf den Trägerwerkstoffen rißfrei bleiben.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150302
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    Jahrbuch Oberflächentechnik 1984, H. W. Lieber, G. Oelsner und W. Riedel. 1. Auflage, Metall-Verlag GmbH, Berlin. 1984, 424 Seiten, zahlreichen Bildern, und Tabellen, DIN A 5, DM 75,80 (Plastikeinband) (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 108-108 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150309
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    Masthead (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984) 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150401
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    Results from investigations with an Instrumented Impact Machine on a molybdenum base alloy, nickel base alloys, and incoloy 800 (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 117-123 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Ergebnisse von Untersuchungen mit einem instrumentierten Kerbschlaghammer an einer Molybdänbasislegierung, Nickelbasislegierungen und Incoloy 800Mit einem instrumentierten Pendelschlagwerk wurden Experimente an der Molybdänbasislegierung TZM, den Nickelbasislegierungen Nimocast 713 LC, Inconel 625, Nimonic 86, Hastelloy S und der Eisenbasislegierung Incoloy 800 durchgeführt. Die Ergebnisse werden unter den Gesichtspunkten der verbrauchten Schlagenergien und der dynamischen Bruchzähigkeit diskutiert.In allen Fällen war die Übereinstimmung zwischen den Energien, die am Schleppzeiger des Hammers abgelesen wurden und den Energien, die durch die Integration des Kraft-Weg Diagrammes ermittelt wurden, ausgezeichnet.Ein Verfahren für die Bestimmung der dynamischen Bruchzähigkeit für eine Last vs. Lastpunktverschiebungskurve mit hohen Oszillationen unter Verwendung einer gemittelten Kurve wurde vorgeschlagen. Verwendet man dieses Verfahren, findet man keinen deutlichen Einfluß der Experimente mit Hammer und Stössel (5,0 m/s und 0,1 m/s) auf die dynamische Bruchzähigkeit. Halbiert man die Fallhöhe, d.h. halbiert man die totale Schlagenergie, so werden die dynamischen Bruchzähigkeitswerte für die Legierungstypen erniedrigt.Niedrige absorbierte Schlagenergien sind oft verknüpft mit hohen Bruchzähigkeitswerten. Hier fehlt die Reserve in der Verformung und/oder im stabilen Rißwachstum.
    Notes: Experiments were performed on the molybdenum base alloy TZM, the nickel base alloys Nimocast 713 LC, Inconel 625, Nimonic 86, Hastelloy S, and the iron base alloy Incoloy 800 with an instrumented impact machine. The results are discussed in terms of absorbed impact energies and dynamic fracture toughness.In all cases the agreement between the energy determined by the dial reading and the energy determined by the integration of the load vs. load point displacement diagram was excellent.A procedure for the determination of the dynamic fracture toughness for load vs. load point displacement diagrams exhibiting high oscillations using an averaged curve is proposed. Using this procedure a pronounced influence of the experiments with tup and chisel (5.0 m/s and 0.1 m/s respectively) on the dynamic fracture toughness is not detectable. Using half the drop height, i.e. halving the total energy, lowers the dynamic fracture toughness values for these types of alloys. Low absorbed impact energies are often combined with high fracture toughness values. In these cases there is no or only a small reserve in deformation and/or stable crack growth.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150403
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    Schweißen im Behälter- und ApparatebauHerrn Prof. Dr.-Ing. Hans Schlachter zum 60. Geburtstag gewidmet (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 149-153 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Welding in Tank and Plant ConstructionSince a relatively limited number of plastics types are used, the welding tasks involved in chemical apparatus engineering can be accomplished with just a few welding techniques are well-known and welding can be carried out efficiently, reliably and economically by this means. In this respect, however, a number of important principles have to be observed. The DVS guidelines provide vital information on questions relating to calculation, design, personnel, equipment, material and testing. Extrusion welding enjoys prime importance as regards quality and economic aspects.
    Notes: Die Schweißaufgaben im chemischen Apparatebau werden an einer relative geringen Anzahl von Kunststofftypen mit wenigen Schweißverfahren bewältigt. Diese Verfahren sind in ihren Grenzen erfaßt und erlauben sichere und wirtschaftliche Schweißungen. Es sind hierbei allerdings eine Reihe wichtiger Grundsätze zu beachten. Die entsprechenden DVS-Richtlinien geben zu Berechnungs-, Gestaltungs, Personal-, Geräte-, Material- und Prüffragen wesentliche Hinweise. Vorrangige Bedeutung im Hinblick auf Qualität und Wirtschaftlichkeit im Behälter- und Apparatebau hat das Extrusionsschweißen.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150502
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    Langzeitprüfung von Schweißverbindungen aus Polyethylen bei komplexer Beanspruchung (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 153-157 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Long Term Testing of Welded Joints from HDPE under Complex LoadingTest methods to determine the long term weld-factors for heated tool butt weldings, extrusion weldings and hot gas weldings are presented. Instead of tensile bars welded pipers are tested under internal pressure to abbreviate the test times. The results of long term creep tests with welded and unwelded PE-HD pipes under the influence of several fluids are also discussed.
    Notes: Für die im Apparate- und Behälterbau am meisten angewandten Schweißverfahren: Heizelementstumpf-, Extrusions- und Warmgas-schweißen werden Prüfmethoden zur Bestimmung der Langzeit-schweißfaktoren vorgestellt. Als Prüfkörper werden hierbei geschweißte Rohre verwendet, um einen mehrdimensionalen Span-nungszustand zu realisieren und die Prüfzeiten zu verkürzen. Desweiteren wird der Einfluß einiger Medien auf geschweißte Rohre im Vergleich mit ungeschweißten Rohren untersucht.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150503
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    Erfahrungen beim Schweißen gasempfindlicher hochreiner WerkstoffeHerrn Prof. Dr.-Ing. Hans Schlachter zum 60. Geburtstag gewidmet (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 183-185 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Experiences in Welding Highly Pure, Gas-Sensitive MaterialsHighly pure steels and non-ferrous react during processing, particularly welding, with atmospheric gases and change their service properties. Hence special measures are often necessary in forming and inert gas welding. Taking the specific example of a high pure chromium steel (superferritic), welding properties, processing data and selection of suitable inert gas torches are described. The possibility of applying this information to other materials such as titanium is discussed.
    Notes: Hochreine Stähle und Nichteisenmetalle reagieren bei der Verarbeitung, insbesondere beim Schweißen mit den Gasen der Luft und verändern ihre Gebrauchseigenschaften. Daher sind vielfach Sondermaßnahmen beim Formieren und Schutzgasschweißen notwendig. Speziell am Beispiel eines Chromstahles hoher Reinheit (Superferrit) werden die Schweißeigenschaften, Daten der Verarbeitung sowie die Auswahl geeigneter Schutzgasbrenner beschrieben. Vergleichende Hinweise und Anwendungsbeispiele für andere Werkstoffe wie z. B. Titan sind möglich.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/mawe.19840150507
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    Dechema-Werkstofftabelle, 12. Ergänzungslieferung. Von DECHEMA D. Behrens, K. Hauffe, H. Puschmann. Verlag Chemie GmbH, Weinheim, 1984, 106 Seiten, zahlreiche Bilder und Tabellen, DIN A 4, DM 307,40 (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 190-190 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150510
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  • 80
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    Investigations into the influence of the tup velocity and the heat treatment on the Dynamic Fracture Toughness of inconel 625 (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 199-206 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Untersuchungen zum Einfluß der Hammergeschwindigkeit und der Auslagerung auf die dynamische Bruchzähigkeit für Inconel 625Mit einem instrumentierten Pendelschlagwerk wurden Experimente an der Nickelbasislegierung Inconel 625 im Anlieferungszustand und nach Auslagerung über 3,6 Ms (1000 h) bei 923 K (650°C) unter Anwendung unterschiedlicher Fallhöhen durchgeführt. Die verbrauchte Schlagenergie kann sowohl über den Schleppzeiger, über die Integration des Kraft-Lastpunktverschiebungs-Diagrammes als auch aus der Integration des Kraft-Zeit-Diagrammes bei gleichzeitiger Kenntnis der Schlaggeschwindigkeit v0 unmittelbar vor Auftreffen des Hammers auf die Probe ermittelt werden. In allen Fällen ist die Übereinstimmung gut.Es wird gezeigt. -daß die dynamische Bruchzähigkeit abhängig ist von der Hammergeschwindigkeit v0 und damit von der totalen Energie des Hammers bei unterschiedlichen Fallhöhen.-daß die Versprödung infolge Wärmebehandlung nicht mit einer Absenkung der Bruchzähigkeit verbunden ist, obwohl eine starke Abnahme der verbrauchten Schlagenergie beobachtet wird. Definiert man eine dynamische Spannung σ aus der Geschwindigkeitsabhängigkeit der Bruchzähigkeit, so ist σ größer für das versprödete Material im Vergleich zum Anlieferungszustand. Diese Tendenz ist von Zugversuchen her bekannt.-daß die dynamische Bruchzähigkeit mit der absorbierten Schlagenergie bis zum Lastmaximum für das wärmebehandelte Material korreliert werden kann, während für den Anlieferungszustand keine Abhängigkeit gefunden wird.Die Änderung der Hammergeschwindigkeit im Verlauf des Stoßprozesses ist nur klein für diesen Werkstofftyp.
    Notes: Experiments were performed with an instrumented impact machine using different drop heights, on the nickel base alloy Inconel 625 in the as-received state and after heat treatment for about 3.6 Ms (1000 h) at 923 K (650°C).The absorbed impact energy can be obtained either by the direct dial reading, by the integration of the load versus load point displacement diagram or by the integration of the load versus time diagram, knowing the initial impact velocity v0 of the tup. In all cases the agreement was excellent.It is shown that. -the dynamic fracture toughness is dependent on the tup velocity v0 and, as a consequence, on the total energy of the hammer at the different drop heights.-defining a dynamic stress σ from the velocity dependence of the fracture toughness, the stress σ is higher for the embrittled material - a tendency verified by tensile tests.-the dynamic fracture toughness can be correlated with the absorbed impact energy up to the load maximum for the heat treated material while the as-received material exhibits no such dependence.The change in the tup velocity during the impact process is only small for this type of material.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150603
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    Verschleiß- und Korrosionsschutz durch ionen- und plasmagestützte Vakuumbeschichtungstechnologien. Vorträge der Internationalen Tagung 15./16. März 1983, Technische Hochschule Darmstadt. THD Schriftreihe Wissenschaft und Technik Band 20, ISBN 3-88607-027-1. Bezugsquelle: Institut für Werkstoffkunde, Grafenstr. 2, 6100 Darmstadt, Preis 48,- DM (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 222-222 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150608
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    Masthead (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984) 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150701
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    Inspection of the heat exchangers of the reactor saphir by Acoustic EmissionVorgetragen in Edinburg: “Symposium on Structural Faults: Inspection and Repair” (22-24 March, 1983) (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 246-250 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Schallemissionsprüfung von Wärmetauschern des Reaktors SaphirDie Schallemissionsanalyse ist eine zerstörungsfreie Prüfmethode, die zur Untersuchung und Überwachung von Strukturen und druckführenden Komponenten verwendet wird. Das Ziel der Messung am 5 MW Forschungsreaktor Saphir war die Untersuchung und Auswertung der hohen Betriebsgeräusche in den Wärmetauschern des Kühl-systems.Die Ergebnisse zeigten, daß von den 9 Wärmetauschern, die in 3 Gruppen angeordnet sind, 5 Wärmetauscher ein hohes Betriebsgeräusch aufweisen. Die Ursache ist auf die Schwingung der Rohrbündel in Wärmetauschern beim Durchfluß des Pool-Wassers zurückzuführen. Die axiale Ortung bestätigte, daß die Geräusche von mehreren Quellen verursacht werden.
    Notes: The acoustic emission technique is a non-destructive testing method used for inspection and surveillance of structures and pressurized components. In particular, the purpose of the measurement on the 5 MW research reactor SAPHIR was to investigate and evaluate the abnormally high noise levels during operation of the heat exchangers of the cooling system.The results showed that 5 heat exchangers out of the total of 9 (assembled in 3 groups) were responsible for the higher noise level. This is probably due to some abnormal vibration of the tube bundles therein, caused by the through-flow of the pool water. Indeed, attempts of localizing the source showed that there must be several, distributed sources.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150705
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    Prüfung der Haftfestigkeit metallischer Überzüge mit dem UltraschallkoppelschwingerAuszug aus der Dissertation des erstgenannten Verfassers, Darmstadt D 17, 1983. (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 250-256 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Ultrasonic Testing of Metal DepositsThe adhesive strength of Ni-deposits has been determined with the well known ring shear test and by a test procedure which usually is used to analyze the resistance of a material against cavitation. In this case the specimen is fastened at the top of an ultrasonic vibrator and oscillates in an aqueous fluid. The deposit/substrate interface is strengthened by high accelerative forces and by mechanical attack of imploding bubbles in the fluid. It was shown that this method is able to distinguish the effect of different pretreatment of the substrate surface. The test result is given as the duration of attack without any exfoliation of the deposit.
    Notes: Die Prüfung der Haftfestigkeit metallischer Überzüge auf z. B. metallischen Grundwerkstoffen spielt eine wichtige Rolle im Hinblick auf die Funktionalität der beschichteten Bauteile im Betrieb. Ihre Bestimmung ist nicht in einfacher Weise möglich, wenn es gilt, Zahlenwerte zu erhalten. Nachfolgend werden zwei Verfahren vorgestellt, von denen das eine, nämlich der ring-shear-test, schon seit längerer Zeit bekannt ist, das andere jedoch, die Untersuchung mit dem Ultraschallkoppelschwinger, neu entwickelt wurde. Die Heranziehung des ring-shear-testes dient in der vorliegenden Arbeit dem Vergleich, wobei hier bekanntlich Zahlenwerte mit der Dimension einer Spannung erhalten werden, während der Versuch mit dem Ultraschallkoppelschwinger Beständigkeitszeiten als Entscheidungskriterium liefert.Gleichzeitig ließ sich mit beiden Methoden der Einfluß der Vorbehandlung auf die Haftfestigkeit eindeutig nachweisen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150706
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    Statistischer Größeneinfluß bei zufallsartiger Schwingbeanspruchung (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 257-264 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Statistical Size Effect at Random LoadingResults of random tests are used to show the applicability of the theory of statistical size effect. The specimens of all the tests of this report were made from the aluminium alloy 7075 T 7351. The specimens were machined from plates (2000 × 1000 × 40 mm). The main dimension of the specimens corresponds with the rolling direction. A standard random load sequence of Gaussian type which is recommended for general application in fatigue testing was used as loading program [19].In a first test series notched round bar specimens (Fig. 2) were used to investigate the sequence effect. 30 specimens were tested with the standard load sequence, 30 specimens with the variable load sequence. All the other test conditions were kept constant. Fig. 4 shows that the scatter of lifetime (cycles to fracture) is not influenced by the load sequence.In a second test series flat specimens with central holes were tested (Fig. 5) in order to show the existence of a pure statistical size effect at random loading. If the specimen has 1, 3 or 7 holes and all the other test conditions are kept constant, only the size of the area where cracks can initiate is enlarged. The results which are plotted in Fig. 6 show a very clear size effect. The results of the 1-hole specimen (A = A0) were used to determine the constants of Eq. (5). By inserting A = 3 A0 resp. A = 7 A0 the other test results can be predicted. In a third test series round bar specimens with a circumferential notch with different notch root radius (ρ = 1 mm resp. ρ = 6 mm) were tested (Fig. 2, Table 1). The specimens were loaded in such a way that the maximum stress in the notch root and its time-dependence was equal. In this very common case, the stress integral must be determined by applying Eq. (3). Additional tests to determine k and numerical calculations were necessary to evaluate Eq. (3). The final results are plotted in Fig. 8. By inserting A = A0 resp. A = 5 A0 into Eq. (7) the results can be described.The basis of the applicability of the theory of statistical size effect is the weakest link concept. The examination of the fracture surface and X-ray analyses showed that there was a higher content of iron (Fig. 11) in those regions where the fatigue cracks initiated. It is supposed that inclusions of intermetallic Al-Fe particles are those weakest links in the structure, where fatigue cracks nucleate.
    Notes: Es wurde der Einfluß der Bauteilgröße auf das Anrißlebensdauerverhalten bei zufallsartiger Schwingbeanspruchung an gekerbten Prüfkörpern aus der Al-Legierung AlZnMgCu 1,5 (7075T7351) untersucht. Durch geeignete Prüfkörperwahl gelang eine Trennung des statistischen (Fehlstellenmodell) und des spannungsmechanischen (Stützwirkungsmodell) Effekts und damit der Nachweis des rein statistischen Einflusses der Baugröße. Darüber hinaus wurde gezeigt, daß das auf dem Fehlstellenmodell beruhende Rechenverfahren auch bei Änderung der Stützwirkung im Bauteil seine Gültigkeit bewahrt. Der Begriff der Fehlstelle konnte durch eine konkrete mikrostrukturelle Werkstoffinhomogenität ersetzt werden. Diese zufällig im Material verteilten Fehler werden als Ursache für die Lebensdauerstreuung angesehen. In diesem Zusammenhang konnte für eine auf einem stationären Gaußprozeß beruhende Lastfolge geklärt werden, daß die Lebensdauerstreuung nicht von der Lastspielreihenfolge abhängt, wenn das Beanspruchungskollektiv und der zeitliche Charakter des Lastablaufs erhalten bleiben.
    Additional Material: 11 Ill.
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    URL: http://dx.doi.org/10.1002/mawe.19840150802
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    Nachrichten - Hinweise (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. A65 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150810
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    Corrosion Potential oscillations (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 309-314 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Oszillationen des Korrosionspotentials bei rostfreien StählenDie Korrosionspotentiale von rostfreien Stählen in chloridhaltigen Lösungen sind in Umgebungen, in denen weder Lochfraß noch Spaltkorrosion auftreten, konstant. In diesen Fall sind die Korrosionspotentiale weitgehend unabhängig von der Temperatur und der Chloridionkonzentration. Bei Stählen mit abnehmendem Korrosions widerstand oder mit zunehmender Temperatur und zunehmender Chloridionkonzentration tritt eine Situation ein, bei der das Korrosionspotential zu oszillieren beginnt - und zwar zwischen zwei Werten, die ungefähr dem Lochfraßpotential Ep und dem Repassivierungspotential Epp entsprechen. Diese Potentialoszillationen sind häufig von Lochfraß und Spaltkorrosion begleitet; andererseits gibt es Fälle, bei denen sogar nach langer Zeit kein Korrosionsanriß sichtbar ist. Die Oszillationen werden einem instabilen Passivitätsverhalten zugeschrieben.
    Notes: The corrosion potentials of stainless steels in chloride solutions for conditions significantly removed from those leading to pitting and crevice corrosion are constant and to a first approximation largely independent of temperature and chloride ion concentration. With increasing temperature and/or chloride ion concentration or with decreasing corrosion resistance there comes a situation when the corrosion potential begins to oscillate, between two and values roughly corresponding to Ep and Epp. These potential oscillations are often associated with pitting and crevice corrosion, although there are clear cases when no corrosion attack was visible even after prolonged exposure. The oscillations are attributed to unstable passivity.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150903
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    Über die Wechselwirkung von Werkstoff und Umformung und ihre Erfassung in VersuchenMitteilung aus dem Institut für Umformtechnik der Universität Stuttgart, Prof. Dr.-Ing. K. Lange. (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 323-330 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: On the Interaction between Work-Material and Forming-Process and its Investigation by ExperimentsExperiments are described and discussed for determining material properties before metal forming as well as process parameters during the metal forming operation and workpiece properties after metal forming.Before metal forming “pure” properties of matter have to be determined which in many cases is achieved by standardized testing methods. During and after the forming operation, however, the testing methods of interest are not yet standardized to the same extent. In particular it is necessary after metal forming, to take into account the effect of geometry on the workpiece properties which results into modified conditions for testing material and workpiece properties.
    Notes: Es werden Versuche beschrieben und diskutiert, in denen Werkstoffeigenschaften vor dem Umformvorgang, Verfahrensparameter während der Umformung sowie Werkstoff- und Werkstückeigenschaften nach der Umformung erfaßt werden können.Zur Bestimmung von Werkstoffeigenschaften vor der Umformung stehen zahlreiche genormte oder sonstwie vereinheitlichte Prüfverfahren zur Verfügung. Dies ist bei Versuchen während und nach der Umformung nicht in gleichem Maße der Fall. Insbesondere muß nach der Umformung der Einfluß der Geometrie auf die Werkstückeigenschaften berücksichtigt werden, wodurch sich veränderte Bedingun-gen für Versuche zur Erfassung von Werkstoff- und Werkstückeigenschaften ergeben.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840150905
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  • 89
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    Zur Erfassung des Korrosionsschutzwertes von Gefrierschutzmitteln mit dem Ultraschall-Koppelschwinger (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 359-362 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840151006
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  • 90
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    Nachrichten - Hinweise (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. A83 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840151008
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  • 91
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    Fracture energy measurements of Ceramic Thermal Barrier Coatings (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 371-377 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Bruchenergiemessungen an keramischen WärmedämmschichtenDie Bruchenergie von plasmagespritzten Wärmedämmschichten aus ZrO2 · MgO, ZrO2 · Y2O3, ZrO3 · CaO · Al2O3 und Al2O3 · TiO2 auf Metallsubstraten wurde sowohl für einen Adhäsionsbruch als auch für einen Kohäsionsbruch der Deckschichten mit Hilfe gekerbter Schichtverbundbiegeproben ermittelt. Die verallgemeinerte Energiefreisetzungsrate wurde als Maß für die Bruchenergie benutzt. Sie berücksichtigt die in der Kraft-Durchbiegungskurve der Proben auftretende Nichtlinearität. Das Versagen der Proben innerhalb der Deckschicht oder in der Grenzfläche wird von der Bildung und Vereinigung von sekundären Rissen in der Deckschicht begleitet. Diese Vorgänge verursachen das nichtlineare Verformungsverhalten und eine von der Rißgeschwindigkeit abhängige Bruchmorphologie.
    Notes: The fracture energy of plasma-sprayed thermal barrier coatings of ZrO2 · MgO, ZrO2 · Y2O3, ZrO2 · CaO · Al2O3, and Al2O3 · TiO2 on metal substrates is obtained for both adhesive and cohesive failure modes of the coatings using notched layer-bonded bend test specimens. The generalized energy release rate was employed as a measure of the fracture energy. It takes account of the nonlinearity found in the load-deflection curves of the specimens. The failure of the specimens within the coating or at the interface is accompanied by the formation and linking of secondary cracks in the coating. This causes the non-linearity in the deformation behaviour and a rate-dependent failure morphology.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840151103
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  • 92
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    Wälzlager auf den Wegen des technischen Fortschritts. FAG Kugelfischer, Schweinfurt. Verlag R. Oldenborugh GmbH, München 1984, 300 Seiten, zahlr. Bilder, zahlr. Tabellen (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 402-402 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840151108
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  • 93
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    Nachrichten - Hinweise (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. A93 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840151111
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  • 94
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    Grundlagen der Schwingfestigkeitssteigerung durch Fest- und Glattwalzen (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 416-420 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Improvement of Fatigue Properties by Roll PeeningWith sophisticated calculations a better understanding of the roll peening process is possible. Calculations together with experimental determination of the fatigue properties allow for a reduced test program to determine the fatigue limit of specimens with similar geometrical shape.
    Notes: Mit Hilfe verbesserter Berechungsverfahren lassen sich vertiefte Erkenntnisse über die Vorgänge beim Festwalzen gewinnen. Darüber hinaus bietet die rechnerische Analyse der Vorgänge zusammen mit der experimentellen Ermittlung der Schwingfestigkeit die Möglichkeit einer Übertragbarkeit auf andere Werkstoffzustände und Proben - bzw. Kerbformen. Hierdurch lassen sich Einsparungen durch verminderten Versuchsaufwand erreichen.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840151204
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  • 95
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    Metallurgie der Schweißung nichtrostender Stähle. Von E. Folkhard, 1. Auflage, Springer-Verlag Wien, New York. 1984, 279 S., 113 Abbildungen, 24 Tabellen, gebunden, 94,- DM (1984)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 15 (1984), S. 436-436 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19840151208
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  • 96
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    On-Line Analysis, Its Potential and Its Problems (1984)
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 1 (1984), S. 7-13 
    Details
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In the application and the development of on-line methods for particle size analysis one has to distinguish three principally different problem areas:aallocation and preparation of a representative sample,banalysis of the sample,cevaluation of the results.Methods and problems connected with these areas will be discussed in this paper. Some of the methods available for rapid response analysis of particle size distributions mark the beginning of a new era of particle size analysis. One has to recognize however that a uniform solution of the problems of on-line particle size analysis is extremely difficult if not impossible to find. The boundary conditions vary to such an extent that similar methods or combinations of methods can rarely be used in different cases. Since instrument manufacturers will in most cases not be able to adopt their instruments to different industrial applications, specialists will have to solve the problem. One has to recognize, however, that not all of the steps described in this paper have been investigated to an extent which renders possible appropriate solutions. There is still room for improvement.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ppsc.19840010102
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  • 97
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    Sampling Powders for Shape Description (1984)
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 1 (1984), S. 22-27 
    Details
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: For some time studies have been made relating the values obtained from simple shape description to bulk powder properties. More recently the detailed mathematical description of particle outline has become possible and quite powerful techniques have been developed. These techniques may be used for the regeneration by computer of the shape and, more importantly, for studies relating shape to individual particle behaviour and to bulk powder properties. Quite inadequate attention has been directed to the task of obtaining from the laboratory sample of the bulk powder a representative sample of shapes without bias. In this communication the considerations to be included in the sampling procedure are reviewed and a possible solution to the problems posed is presented.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ppsc.19840010104
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  • 98
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    Dispersion of Samples and Sample-feeding for Counting Methods (1984)
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 1 (1984), S. 28-31 
    Details
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The currently used methods of sample preparation are examined and found to be unsatisfactory in case of counting methods for particle size analysis. It is the purpose of this paper to review the results of investigations of two different measuring principles (light extinction and electrical resistance change) by use of the same signal handling equipment. The commonly used techniques and units are compared with regard to the resulting density distributions of particle size below 0.25 mm. The final conclusions including recommendations to the use of ultrasonic treatment and to improvements of the sampling and the sample-feeding units are valid for all counting methods.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ppsc.19840010105
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  • 99
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    Errors in the Determination of Particle Size Distributions Caused by coincidences in optical particle counters (1984)
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 1 (1984), S. 53-58 
    Details
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: When performing particle size analysis by scattered light, coincidences in the measuring volume of optical particle counters not only cause too small a particle concentration to be measured, but also a size distribution to be obtained which is systematically shifted towards coarser particle sizes. It is pointed out in this paper how this shift can be precalculated when the true distribution is given. The results show under which conditions a correction of the measured distribution is indispensable.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ppsc.19840010109
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  • 100
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    The Application and Potential of Cluster Analysis in the Interpretation of multivariate particulate data (1984)
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 1 (1984), S. 78-84 
    Details
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The classification of powders into groups possessing specific behavioural identities has long been recognized as desirable. This has been approached by describing different powders using two variables and plotting the data on a scatter diagram. The property of interest is then inferred from a powder's position on the scatter diagram. Unfortunately, a powder's behaviour is rarely adequately described by only two variables. To describe a powder more fully requires more variables and this presents a problem in interpretation. Cluster analysis refers to a range of techniques for interpreting multivariate data sets and is used in many fields. This paper describes cluster analysis and considers the method and potential of its application to particle technology. By way of an illustration, a cluster analysis has been performed on twenty-seven powders resulting in groups recognizable by their characteristic fluidisation and flow properties. It is concluded that cluster analysis could be a powerful tool in predictive and analytical work in the field of particle technology.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ppsc.19840010113
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