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  • 1985-1989  (2,840)
  • 1975-1979  (1,543)
  • Engineering  (3,477)
  • Electron microscopy  (906)
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  • 1
    Electronic Resource
    Electronic Resource
    Diffusion barrier properties of the perineurium: an in vivo ionic lanthanum tracer study (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 237-242 
    Details
    ISSN: 1432-0568
    Keywords: Perineurium ; Lanthanum ; Diffusion barriers ; In vivo ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary While the perineurium as a diffusion barrier has been extensively investigated by light and electron microscopy, copy, such studies have been largely restricted to the use of protein tracers. In the present study the permeability of the perineurium to a physiologically more relevant ionic tracer has been assessed. In vivo the rat sural or tibial nerve was either microinjected with lanthanum nitrate solution for endoneurial application or bathed in the lanthanum solution for epineurial application. The findings generally demonstrated an effective barrier to the tracer which failed to penetrate the inner layers of the perineurium. Only at the highest lanthanum concentration and longest time intervals employed did trace quantities occasionally penetrate the barrier and then only in the presence of some cytopathological changes to the outermost perineurial cells. The usefulness of the microinjection method was limited by the slight but unavoidable trauma to the perineurium. The findings are related to those of other studies which have used electron dense tracers, also to studies using physiological including electrophysiological techniques and morphological including freeze-fracture methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315882
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  • 2
    Electronic Resource
    Electronic Resource
    Synaptogenesis in the dorsal lateral geniculate nucleus of the rat (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 243-257 
    Details
    ISSN: 1432-0568
    Keywords: Dorsal lateral geniculate nucleus ; Synapse formation ; Synaptic glomerulus ; Rat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Synapse formation and maturation were examined in the rat dorsal lateral geniculate nucleus (dLGN) from birth to adulthood. Examination of animals, whose ages were closely spaced in time, showed that the maturation of the synaptic organization of the nucleus takes place chiefly during the first 3 weeks of postnatal life. This period of maturation may be divided into 3 broad stages. During the first stage, which spans the first 4 days of life, there are only a few immature synapses scattered throughout the nucleus; occasionally aggregates of 3 or 4 synapses are encountered. Dendrodendritic synapses first appear at the end of this stage. The second stage, which lasts from the end of the first stage through day 8, is characterized by intensive synaptogenesis as well as extensive growth and degeneration. For the first time, large boutons resembling retinal terminals form multiple synaptic contacts with dendrites and dendritic protrusions; these synaptic arrangements are partially covered by glial processes. A feature characteristic of the developing dLGN during the first 2 postnatal weeks, and particularly during the second stage, is the presence of membrane specializations that resemble vacant postsynaptic densities. These specializations, which may be unapposed or opposite another neuronal process, decrease in frequency as the number of synapses increases. It is not known whether these densities are converted to synapses or whether they result from loss of presynaptic elements. The third stage in the process of synaptogenesis, which spans a period between days 10 and 20, is characterized by myelination and by the diminution of growth cones, degenerating profiles and vacant postsynaptic densities. There is also a very significant increase in the number and maturation of synapses including synaptic glomeruli. However, it is not until the end of this stage that synapses appear qualitatively indistinguishable from synaptic arrangements identified in adult animals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315883
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  • 3
    Electronic Resource
    Electronic Resource
    Myelin breakdown in the posterior funiculus of the kitten after dorsal rhizotomy (1989)
    Springer
    Anatomy and embryology 180 (1989), S. 273-280 
    Details
    ISSN: 1432-0568
    Keywords: Wallerian degeneration ; Myelin breakdown ; Light microscopy ; Electron microscopy ; Marchi staining
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Morphological aspects of myelin breakdown in the posterior funiculus during Wallerian degeneration were studied in kittens subjected to lumbosacral dorsal rhizotomies 6–8 days after birth. The first sign of myelin breakdown was characterized by swollen or shrunken nerve fibers. Shortly thereafter there was an increased occurrence of collapsed myelin sheaths and later of rounded myelin bodies. Myelin was clearly seen in microglial cells. Correlative observations on Marchi-stained material indicated the simultaneous and frequent appearance of Marchi-positive bodies (MPB:s) and myelin bodies. Due to the rapidity of the degeneration process in the kitten, the increase in the occurrence of Marchi-positive granules (MPG:s) seemed to start concomitantly with increased occurrence of MPB:s. However, the frequent occurrence of MPG:s outlasted that for MPB:s. The findings indicate that the MPB:s may be the counterpart to myelin bodies and the MPG:s to lipid droplets. Microglial cells may be responsible for the primary uptake of degenerating myelin and the subsequent transformation of myelin bodies to lipid droplets. The much faster breakdown of myelin and elimination of lipid material in the degenerating posteror funiculus of the kitten, as compared to the adult, seemed to be due not only to the lower myelin content in the kitten, but also to a higher density of microglia and a greater efficiency in the myelin breakdown process in the degenerating posterior funiculus of the kitten.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315885
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  • 4
    Electronic Resource
    Electronic Resource
    Hypomyelination in the neonatal rat central and peripheral nervous systems following tellurium intoxication (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 301-309 
    Details
    ISSN: 1432-0533
    Keywords: Schwann cell ; Oligodendrocyte ; Electron microscopy ; Myelin ; Optic nerve
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neonatal rats were exposed to Tellurium (Te), via the mother's milk, from the day of birth until sacrifice at 7, 14, 21, and 28 days of age. Light and electron microscopy revealed Schwann cell and myelin degeneration in the sciatic nerves at each age studied. These changes were similar to those described in weanling rats as a result of Te intoxication. In the CNS, hypomyelination of the optic nerves was convincingly demonstrated at 14, 21, and 28 days of age, accompanied by some evidence of myelin degeneration. These changes were also seen in the ventral columns of the cervical spinal cords, although less markedly, and were confirmed by quantitative methods. There was little evidence of oligodendrocyte pathology in the CNS, and it appears that degeneration of these cells is not the primary cause of the CNS hypomyelination, in contrast to the PNS where Schwann cell degeneration has been shown to precede the myelin pathology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687760
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  • 5
    Electronic Resource
    Electronic Resource
    Pick bodies in the locus ceruleus (1989)
    Springer
    Acta neuropathologica 79 (1989), S. 10-17 
    Details
    ISSN: 1432-0533
    Keywords: Locus ceruleus ; Pick bodies ; Lewy bodies ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In classical Pick's disease with typical Pick bodies, inclusions resembling those present in the cerebral cortex are frequently found in the locus ceruleus. In three such cases Pick bodies were studied by light and electron microscopy and compared with Lewy bodies, inclusions more commonly found in this location. In contrast to the situation in the cerebral cortex, nerve cells with multiple Pick bodies were often found in the locus ceruleus, but in other respects definite light and electron microscopic differences between Pick bodies and Lewy bodies were present. Pick bodies were slightly basophilic and never had a central core or a peripheral halo. They were intensely argyrophilic. Differences in immunocytochemical reactions were especially marked with antibodies to tau and to paired helical filaments. Pick bodies displayed an intense reaction with these two antibodies, contrasting with that of Lewy bodies, which either lacked reactivity or reacted in a peripheral band. By electron microscopy the Pick bodies were composed of random filaments with smooth contour, whereas typical Lewy bodies had fuzzy deposits on filaments that radiated from a central core. Pick bodies in the locus ceruleus therefore maintained their immunocytochemical and electron microscopic characteristics and did not take on the character of Lewy bodies. Such differences point to a different pathogenesis and perhaps etiology of these two types of inclusions and attest to the marked difference clinically and pathologically between Pick's and Parkinson's diseases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00308950
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  • 6
    Electronic Resource
    Electronic Resource
    Electron microscopic and Golgi study in a case of hemimegalencephaly (1989)
    Springer
    Acta neuropathologica 77 (1989), S. 664-666 
    Details
    ISSN: 1432-0533
    Keywords: Hemimegalencephaly ; Golgi study ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pathological findings in a case of hemimegalencephaly are presented. Hemispherectomy, performed because of intractable seizures, allowed an electron microscopic and Golgi study. Glial abnormalities consisted of hyperplasia of glia cells with giant astrocytes often containing several nuclei and proliferation of numerous Rosenthal fibers. Golgi stain showed many giant neurons with a perikaryon covered by perisomatic processes, and a complex dendritic tree. Glial abnormalities could be correlated with the firmness of the hemisphere and intense hypersignal on magnetic resonance imaging. Giant neurons were associated with an increase in size of the perikaryon and dendritic tree; this pattern suggests a polyploidy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687896
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  • 7
    Electronic Resource
    Electronic Resource
    Melanotic paraganglioma of the orbit: a case report (1989)
    Springer
    Acta neuropathologica 79 (1989), S. 340-346 
    Details
    ISSN: 1432-0533
    Keywords: Paraganglioma ; Melanin ; Orbit ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A paraganglioma of the orbit in a 21-year-old woman is presented, containing oculo-cutaneous melanin in many tumor cells, occasionally adjacent to neurosecretory granules, and in macrophages. This tumor expands the list of neuroectodermal tumors with potential melaninization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294673
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  • 8
    Electronic Resource
    Electronic Resource
    The astroblastoma and its possible cytogenic relationship to the tanycyte (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 472-483 
    Details
    ISSN: 1432-0533
    Keywords: Astroblastoma ; Electron microscopy ; Immunohistochemistry ; Organ culture ; Tanycytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two examples of cerebral astroblastoma have been studied by electron microscopy and immunohistochemistry, one of them having been maintained in vitro in an organ-culture matrix system for 8 months and the explants studied by light and electron microscopy at different time intervals. The fine structural characteristics were those of a glial cell type with features intermediary between those of astrocytes and ependymocytes. They recapitulated the structure of the tanycyte, a glial precursor cell which is normally found scattered along the ependymal lining of the embryonal and neonatal mammalian brain, but is distinct from epithelial ependymocytes. The possible origin of some astroblastomas from such a cell would account for a number of characteristics in this enigmatic type of glioma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687708
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  • 9
    Electronic Resource
    Electronic Resource
    Sporadic motor neuron disease with Lewy body-like hyaline inclusions (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 555-560 
    Details
    ISSN: 1432-0533
    Keywords: Sporadic motor neuron disease ; Lewy body-like hyaline inclusions ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Lewy body-like hyaline inclusions were immunocytochemically and electron microscopically investigated in a patient with sporadic motor neuron disease. The hyaline inclusions were chiefly observed within the perikarya of both normal-looking and chromatolytic anterior horn cells in the lumbar spinal cord, but some were detected in the axons and dendrites. Usually, a single inclusion was found in the perikaryon, but in rare cases two or more were observed. Immunocytochemically, these inclusions were intensely immunostained with anti-ubiquitin anti-body. Ultrastructurally, the hyaline inclusions were chiefly composed of randomly arranged linear structures associated with ribosome-like granules, varying from compactly arranged linear densities to more loosely packed ones. They contained scattered vesicles of various sizes and occasionally a focal accumulation of randomly arranged 10-nm neurofilaments or 13–25-nm filamentous structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687719
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  • 10
    Electronic Resource
    Electronic Resource
    Morphological studies on cerebral cortical lesions induced by transient ischemia in Mongolian gerbil —Diffuse and peripheral pallor of the neuronal perikarya (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 1-8 
    Details
    ISSN: 1432-0533
    Keywords: Cerebral ischemia ; Ischemic neuronal injury ; Long-term recovery ; Mongolian gerbil ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Unilateral transient cerebral ischemia was produced in Mongolian gerbils by clipping the left common carotid artery for 1h. About 60% of the gerbils with neurological symptoms had post-ischemic seizures. The majority of those that had seizures died within a few days, and sections of their cerebral cortices contained many dark and shrunken neurons. However, the gerbils that did not have seizures survived without any severe complications. In the cerebral cortex of the latter, the neurons with diffuse or peripheral pallor of the perikarya were seen along with a small number of dark and shrunken neurons. Diffuse pallor occurred within a few hours following ischemia in layers III, V and VI, and disappeared 1 or 2 days after recirculation. Electron microscopically, these neurons showed dispersion of ribosomes, simple and elongated profiles of rough endoplasmic reticulum (r-ER), clustered vacuoles, and mild to moderate mitochondrial swelling. Occasional net-like tubulomembranous structures, probably derived from r-ER, were observed. On the other hand, peripheral pallor became apparent after 5 days following ischemia, usually involving layer II first and gradually extending to the deeper layers. Concomitantly, the amount of neuropil decreased and the dendrites exhibited tortuosity and irregularity in layer II. Electron microscopically, these neurons showed marked swelling of peripheral perikarya and polyribosomes and organelles were located peripherally to the nuclei. In addition, numerous degenerated axon terminals and distended dendrites were observed around the neurons. These observations indicate that diffuse pallor represents damage directly induced by ischemia and subsequent recirculation, while peripheral pallor is the delayed and remote effect of ischemia, probably due to degeneration of neuronal processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687395
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  • 11
    Electronic Resource
    Electronic Resource
    Disseminated human neurocysticercosis (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 594-604 
    Details
    ISSN: 1432-0533
    Keywords: Neurocysticercosis ; Pathogenesis ; Histochemistry ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This study was based on two cases of disseminated human neurocysticercosis from India. The material availabel was examined grossly, and by light microscopy, histochemistry, immunomorphology and electron microscopy. The results showed that the parasites commonly embolized to the anatomically discernable gray-white matter junction of the brain and were located in cavities, the walls of which were dilated vascular channels. The parasite-nutrition process was through endocytosis and microtrichal activity. To camouflage themselves from the host-defense mechanisms, the parasites apparently covered themselves with host-tissue-like material. Host reactivity to the parasite was heralded morphologically by the physical anchoring of the parasite by activated endothelial cells, loss of the host-tissue-like cover and an acute polymorphonuclear leucocytic response.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691286
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  • 12
    Electronic Resource
    Electronic Resource
    Senile plaque-like structures: observation of a probably unknown type of senile plaque by periodic-acid methenamine silver (PAM) electron microscopy (1989)
    Springer
    Acta neuropathologica 78 (1989), S. 137-142 
    Details
    ISSN: 1432-0533
    Keywords: Senile plaque-like structure ; Periodicacid methenamine silver (PAM) method ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Numerous diffuse senile plaque-like structures (SPLSs) were found in the cerebral cortex from cases with dementia of the Alzheimer type by means of the methenamine-Bodian method. SPLSs varied in shape and size. They were never recognized in the original Bodian, PAS and Congo red preparations, but were positive with anti-β-protein immunostaining and periodic-acid methenamine silver (PAM) methods, which are thought to specifically stain amyloid substance. With PAM electron microscopy, we found sparse aggregations of amorphous, often ramified, structures with fine granular silver deposits in SPLS. Routine electron microscopic examination on the same portion where SPLS were confirmed by PAM electron microscopy revealed amorphous, partially fibrous structures. These structures might be amyloid or amyloid-precursor substance. In SPLSs only a few degenerated neurites and astrocytic processes with glycogen granules were seen. We consider SPLSs to be a kind of senile plaque.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688201
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  • 13
    Electronic Resource
    Electronic Resource
    Localization of aggregation substances of Enterococcus faecalis after induction by sex pheromones (1989)
    Springer
    Archives of microbiology 151 (1989), S. 491-497 
    Details
    ISSN: 1432-072X
    Keywords: Aggregation substance ; Enterococcus faecalis ; Electron microscopy ; Field emission scanning electron microscopy ; Immunogold labelling technique ; Sex pheromone system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The distribution of sex pheromone induced aggregation substance was studied on the cell surface of various Enterococcus faecalis strains. In the accompanying paper we have shown that the aggregation substance appears as a layer of hairlike structures. Using direct and indirect immunogold technique, transmission electron microscopy and high resolution scanning electron microscopy we investigated the appearance and distribution of the aggregation substance. The “hairs” increase in number with increasing exposure to sex pheromones (maximum density: 1300/μm2). We show that these structures are unequally distributed over the cell surface, even if the cells were induced by sex pheromones for a long period of time. Statistical analysis of the unequal distribution indicates that aggregation substance is incorporated into pre-existing “old” cell-walls and that this incorporation shows a saturation ca. 40 min after addition of sex pheromones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00454864
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  • 14
    Electronic Resource
    Electronic Resource
    Neural crest origin of clear cell sarcoma of tendons and aponeuroses (1989)
    Springer
    Virchows Archiv 415 (1989), S. 51-60 
    Details
    ISSN: 1432-2307
    Keywords: Clear cell sarcoma ; Melanosomes ; Cytochemistry ; Electron microscopy ; Nude mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to clarify the histogenesis of clear cell sarcoma of tendons and aponeuroses (CCS), two cases of human and one nude mouse-transplanted CCS line were studied using an ultrastructural and enzyme cytochemical approach. Most of the tumour cells obtained from the primary and transplanted CCS demonstrated melanosomes in various stages of development within the cytoplasm, whereas no melanosomes could be identified in the metastatic CCS. However, cholinesterase and tyrosinase activities could be demonstrated not only in the melanotic primary and transplanted CCS but also in the amelanotic metastatic CCS. The results therefore support the hypothesis that CCS is a soft tissue tumour derived from the neural crest.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718604
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  • 15
    Electronic Resource
    Electronic Resource
    An immunohistochemically defined non-Hodgkin's lymphoma showing intercellular junctions (1989)
    Springer
    Virchows Archiv 415 (1989), S. 297-300 
    Details
    ISSN: 1432-2307
    Keywords: Non-Hodgkin's lymphoma ; Electron microscopy ; Immunohistochemistry ; Intercellular junction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A rare example of pleomorphic B cell non-Hodgkin's lymphoma is described in which tumour cells possessed simple intercellular junctions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00724918
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  • 16
    Electronic Resource
    Electronic Resource
    Immunocytochemical and morphometric analysis of acinar zymogen granules in human acute pancreatitis (1989)
    Springer
    Virchows Archiv 415 (1989), S. 115-124 
    Details
    ISSN: 1432-2307
    Keywords: Human acute pancreatitis ; Zymogen granules ; Acinar cells ; Electron microscopy ; Immunocytochemistry ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the present study fine structural changes of acinar zymogen granules were investigated in human acute pancreatitis. Pancreatic tissue was obtained at surgery from 6 patients, prepared for ultrastructural analysis, and stained immunocytochemically for trypsinogen. Stereological parameters of zymogen granules were evaluated. The density of the immunocytochemical labelling for trypsinogen was estimated over zymogen granules, the rough endoplasmic reticulum, Golgi apparatus and the acinar lumina. In acute pancreatitis the number of zymogen granules was diminished and their size reduced. The density of the labelling for trypsinogen was unchanged over zymogen granules but showed a significant reduction over the rough endoplasmic reticulum, Golgi apparatus, and the acinar lumina. In general the integrity of zymogen granules was well preserved. Focally degenerative changes of zymogen granules and large autophagosomes were observed. From the immunogold labelling a disturbance of enzyme synthesis and secretion was suggested. Evidence is given that a disruption of the zymogen granule membranes and a fusion with lysosomal bodies might contribute to the pathogenesis of human acute pancreatitis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00784348
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  • 17
    Electronic Resource
    Electronic Resource
    Salivary gland myoepithelioma variants (1989)
    Springer
    Virchows Archiv 416 (1989), S. 25-42 
    Details
    ISSN: 1432-2307
    Keywords: Salivary gland ; Myoepithelioma ; Neoplasm ; Electron microscopy ; Immunohistochemistry ; Cytoplasmic filaments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The histological and ultrastructural features of five major salivary gland tumours, which have little or no evidence of duct- or gland-type differentiation in routine sections, are described. Four of the cases have the tumour cells organized as narrow, anastomosing cords of cells separated by a myxoid and vascularized stroma; we have designated such lesions as reticular-type myoepitheliomas. The fifth case has a solid growth pattern and is largely composed of hyaline cells, that is, a plasmacytoid myoepithelioma. Ultrastructurally, one reticular myoepithelioma reveals myoepithelial cell differentiation with microfilament aggregates, while the other three examples are composed of modified myoepithelial cells displaying widened intercellular spaces, prominent synthesis of extracellular glycosaminoglycans, distinct basal lamina development, and obvious accumulations of cytoplasmic intermediate filaments. In electron micrographs, the modified myoepithelial cells of the plasmacytoid variant closely resemble the tumour cells in the reticular form. Three cases had expression of both glial fibrillary acid protein (GFAP) and vimentin, but only one of the myoepitheliomas contained muscle-specific actin. At least focally, each of the cases exhibited a considerable spectrum of cytokeratin filaments. Using double-labeled immunofluorescent microscopy of one reticular variant and the plasmacytoid myoepithelioma, there was individual tumour cell co-expression of GFAP and vimentin focally in the plasmacytoid myoepithelioma, but co-expression of cytokeratins 13, 16 and GFAP were not noted in either case. As expected, co-expression of high- and low-molecular weight cytokeratin filaments was wide-spread in both myoepitheliomas. Most described myoepitheliomas have a solid growth pattern and are composed of spindle and plasmacytoid cells, but based on cytological features and growth patterns in this series, it is apparent that polygonalshaped cells with novel architecture can occur in myoepitheliomas. The results also indicate the close relationship between pleomorphic adenoma and such variants of myoepithelioma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01606467
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  • 18
    Electronic Resource
    Electronic Resource
    Early bronchopulmonary lesions in rat lung after normobaric 100% oxygen exposure and their evolution (1989)
    Springer
    Virchows Archiv 414 (1989), S. 135-145 
    Details
    ISSN: 1432-2307
    Keywords: Hyperoxia ; Lung broncho-vascular reaction ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to clarify the early phenomena involved in the lung reaction to hyperoxia, twenty adult male rats were exposed to 100% oxygen at 1 ATA. Morphological pulmonary lesions were detectable after only 24 h hyperoxia, and included vasoconstriction and perivascular oedema, bronchiolar constriction, and pericyte reaction. The lesions were irregularly scattered within the lung parenchyma and occurred preferentially in areas centred on bronchiolo-vascular stems. Even at the latest stages, pulmonary heterogeneity was obvious, from the coexistence of areas damaged at different times. Neuro-epithelial-bodies were found under the bronchiolar epithelium; the morphological aspect of the neuro-endocrine cells observed was consistent with hyperoxia-induced modulation of their secretory activity. Taken together, our findings show the speed of development of hyperoxia-induced pulmonary changes and raise some pathogenic considerations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718593
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  • 19
    Electronic Resource
    Electronic Resource
    Liver parenchymal cell parasitism in human visceral leishmaniasis (1989)
    Springer
    Virchows Archiv 415 (1989), S. 1-6 
    Details
    ISSN: 1432-2307
    Keywords: Visceral leishmaniasis ; L. donovani ; Parasitism ; Liver pathology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Liver parenchymal cell parasitism with the amastigotes form ofL. donovani was detected by electron microscopy in human visceral leishmaniasis. Endocytosis was considered to be the mechanism by which the leishmania entered the cell. Evidence of well preserved parasites within hepatocytes suggest this parasitism as a possible reservoir for recrudescence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718599
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  • 20
    Electronic Resource
    Electronic Resource
    Collagen secretion granules in reactive stromal myofibroblasts, with preliminary observations on their occurrence in spindle cell tumours (1989)
    Springer
    Virchows Archiv 415 (1989), S. 437-445 
    Details
    ISSN: 1432-2307
    Keywords: Collagen secretion granule ; Myofibroblast ; Spindle cell tumour ; Electron microscopy ; Diagnosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Collagen secretion granules, representing stages in the intracellular packaging, transport and secretion of collagen-fibril precursor, have been studied by transmission electron microscopy in non-neoplastic human myofibroblasts and in neoplastic cells from a preliminary study of tumours exclusively or partly of spindle cell type. Vesicles, newly separated from Golgi saccules and containing finely fibrillar material, were identified as early presecretory granules, the most immature type of granule. Later stages exhibited longitudinally arranged, densely fibrillar bundles. Subsequently, secretory granules developed more homogeneously dense content. Fibril-containing cisternae near the plasma membrane were interpreted as either endocytotic or lysosomal structures, or as participants in the final stages of secretion. The features by which collagen secretion granules can be distinguished from other Golgi products, in particular melanosomes, Weibel-Palade bodies and lysosomes, are pointed out. The significance of these organelles for cell identification and tumour diagnosis is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00747745
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  • 21
    Electronic Resource
    Electronic Resource
    Biologic roles of the innermost cell layer of the outer root sheath in human anagen hair follicle: further electron microscopic study (1989)
    Springer
    Archives of dermatological research 281 (1989), S. 254-259 
    Details
    ISSN: 1432-069X
    Keywords: Innermost cell layer ; Tonofilaments ; Huxley's cells ; Henle's cells ; Anagen hair follicles ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To elucidate the biologic roles and further cytologic characteristics of the innermost cell (IMC) layer of the outer root sheath (ORS), human anagen hair follicles were ultrastructurally examined. In the lower follicle, the transeversely running tonofilaments in the inner side of the cytoplasm of the IMCs showed a massive accumulation, facing the keratinized part of a Huxley's cell protruding through a Henle's pore. In a rare instance, a spindle-shaped cell was seen between the IMC layer and the keratinized Henle's layer. At the lower isthmus portion, some of the IMCs containing a large number of tonofilaments showed a partial degeneration of the inner side of the cytoplasm. More distally, intercellular spaces between the keratinized IMCs and keratinized Henle's cells were partly dilated and contained amorphous substances. It is suggested that the IMCs in the lower follicle may play a role to support and cover the inner hair structures, tightly as hoops of a barrel. In the isthmus portion, the IMCs may loosely support and guide the keratinized Henle's cells undergoing degeneration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00431059
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  • 22
    Electronic Resource
    Electronic Resource
    Netherton's syndrome: ultrastructure of the active lesion under retinoid therapy (1989)
    Springer
    Archives of dermatological research 281 (1989), S. 165-172 
    Details
    ISSN: 1432-069X
    Keywords: Netherton's syndrome ; Retinoid therapy ; Etretin ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A young female patient, expressing the symptom triad of Netherton's syndrome, i.e., ichthyosis linearis circumflexa Comèl, trichorrhexis invaginata and other hair shaft defects, and atopic diathesis, has been treated successfully with the new retinoid preparation Etretin. Our electron microscopical study especially focused on the ultrastructural effect on the characteristic, active part of the skin lesions, which is only found within a narrow borderline just preceding the lesion's margin. In untreated skin, this part is characterized by dermal inflammation, immigrating inflammatory cells, and specific keratinization disturbances: synthesis of keratinization proteins is suppressed, serum exudates invade the epidermis, either filling the intercellular spaces of the upper spinous and the granular layer as finely granular, amorphous material, or they are partly phagocytosed and lie within intracellular, round-oval inclusions. The portions of the lesions lying towards the center are unspecific and represent recovery stages, ultrastructurally resembling stages of normal wound repair. Oral therapy with Etretin did not heal the basic defect, but drastically reduced exoserosis and the deposition of intra- and extracellular material. Keratinization seemed to normalize. The condition of the hair was also improved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00456387
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  • 23
    Electronic Resource
    Electronic Resource
    Mitochondrial encephalomyopathy with pilovacuolar inclusion or phenocopy with mitochondrial artefact? (1989)
    Springer
    Journal of neurology 236 (1989), S. 361-363 
    Details
    ISSN: 1432-1459
    Keywords: Mitochondrial encephalomyopathy ; MELAS ; Mitochondrial inclusion ; Pilovacuolar inclusion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The case of a 33-year-old man with clinical features of mitochondrial encephalomyopathy is presented. He suffered from recurrent cerebral infarctions, cerebellar ataxia, deafness, retinopathy, weakness, and cardiac and renal disorders. Biochemical and light microscope investigations of skeletal muscle did not show any mitochondrial abnormality. Electron microscopy revealed the presence of a hitherto unreported peculiar “pilovacuolar” inclusion in numerous mitochondria, composed of an electron dense pile or rod within a vacuole, while globular or crystalline inclusions were absent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00314383
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  • 24
    Electronic Resource
    Electronic Resource
    Human fetal endometrium -light and electron microscopic study (1989)
    Springer
    Archives of gynecology and obstetrics 246 (1989), S. 169-179 
    Details
    ISSN: 1432-0711
    Keywords: Human fetal endometrium ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Human fetal endometrium was examined by light and electron microscopy. Our study shows the following new morphological aspects: (1) Glands are already present. (2) Endometrium undergoes a maturation process during gestation and at late gestational age resembles late proliferative endometrium. (3) The nuclear bodies are present in cell nuclei throughout gestation. (4) Nucleolar channel systems (NCS) sometimes appear at a late gestational age. (5) Cells with the same morphology as that of endocrine cells are found in the basal layers of endometrium at a late gestational age. The significance of these morphological aspects is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00934078
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  • 25
    Electronic Resource
    Electronic Resource
    Rodent and primate adrenal medullary cells in vitro: phenotypic plasticity in response to coculture with C6 glioma cells or NGF (1989)
    Springer
    Experimental brain research 76 (1989), S. 38-46 
    Details
    ISSN: 1432-1106
    Keywords: Nerve growth factor ; C6 glioma cells ; Chromaffin cells histofluorescence ; Electron microscopy ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to maintain a chronic supply of growth factor for medulla cells in vitro, chromaffin cells from rat, African green monkeys and man were co-cultured with C6 glioma cells, which secrete growth factors that sustain sympathetic neurons in vitro. The response of chromaffin cells to coculture was compared to treatment of medullary cells with nerve growth factor (NGF) alone. Dispersed chromaffin cell preparations were obtained by a trypsin-collagenase procedure, and subjected to differential plating on collagen-coated surfaces. With both human and monkey tissue, non-chromaffin cells did attach to the culture plates and an enriched chromaffin cell population could be replated. Rat adrenal medulla cells survived very poorly in vitro and were not enriched in this procedure. Cultured human and monkey chromaffin cells survived as epithelial cells (50%) and showed neuritic outgrowth on 55 to 66% of the cells after eight days when treated with nerve growth factor (NGF). These cells showed strong catecholamine histofluorescence, tyrosine hydroxylase (TH) and dopamine beta hydroxylase (DBH) immunoreactivity. In contrast, only ten percent of adult rat chromaffin cells survived in culture, although NGF treatment rescued an additional 20% of the cells and induced neuritic outgrowth after one week in vitro. C6 glioma cells were treated with mitomycin C bromodeoxyuridine to inhibit mitosis and were plated with the various medulla cells in a one to one ratio. Both human and monkey chromaffin cells expressed extensive and enhanced neuritic arborization within eight days of co-culture, (64–82% respectively) and exhibited intimate contact with the glioma cells as seen at the ultrastructural level. Importantly, survival of adult rat adrenal medulla cells was enhanced to 50% or more with 40% of the cells extending neurites when co-cultured with glioma cells for seven days. Chromaffin cells from all three species reacted for TH, DBH and PNMT in co-culture and were histofluorescent. The majority of these cells were also immunoreactive for serotonin and enkephalin, while only 37% of chromaffin cells indicated the presence of NPY. These data indicate that adrenal medulla can be maintained in vitro as the neuronal phenotype when co-cultured with growth factor producing cells and that this strategy may be useful for in vivo transplantation studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00253621
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  • 26
    Electronic Resource
    Electronic Resource
    An ultrastructural study of the hypertrophied human papillary muscle cell with special emphasis on specific staining patterns, mitochondrial projections and association between mitochondria and SR (1989)
    Springer
    Virchows Archiv 414 (1989), S. 187-198 
    Details
    ISSN: 1432-2307
    Keywords: Human heart ; Papillary muscle ; Hypertrophy ; Mitochondria ; Specific staining ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Biopsy material of the hypertrophied human papillary muscle has been processed according to various electron microscopical techniques in order to study the mitochondrial ultrastructure and the association between mitochondria and sarcoplasmic reticulum (SR).En bloc staining with a Cu-Pb citrate solution resulted in specifically contrasted mitochondrial and sarcotubular membranes, characterized by numerous, discrete, electron-dense particles. The differences in staining patterns between the perinuclear mitochondria and their subsarcolemmal and interfibrillar counterparts suggest differences in chemical properties and/or metabolic activities. The selectively contrasted mitochondrial particles may represent a conglomorate of extrinisic and intrinisic respiratory enzymes and other membrane-associated proteins, while the majority of the electron-dense particles of the sarcotubular membrane may represent positively stained Ca2+-pumps. Ultrastructural findings in the present study strongly indicate that the slender mitochondrial projections represent an initial stage in a process leading to the formation of large and pleomorphic mitochondria. Intimate contact between adjacent mitochondria as well as between mitochondria and SR are documented. In the contact regions some of the specifically contrasted particles of the adjacent membranes had fused with each other. It is suggested that these particles represent membrane-bound transport proteins providing a system for interorganelle exchanges of metabolites and/or ions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00822022
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  • 27
    Electronic Resource
    Electronic Resource
    Ultrastructural and electron immunohistochemical features of medullary thyroid carcinoma (1989)
    Springer
    Virchows Archiv 414 (1989), S. 375-384 
    Details
    ISSN: 1432-2307
    Keywords: Thyroid neoplasms ; Electron microscopy ; Immunohistochemistry ; Calcitonin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural study, both morphological and immunohistochemical, has been carried out on eight thyroglobulin-positive and nine thyroglobulin-negative medullary carcinomas of the thyroid. The morphometric analysis of granule size showed that all tumours contained cells with small granules and cells with medium size granules, whereas eight tumours had additional cells with large granules. The small granules had an electron dense core, while the medium and large sized granules were both pale-cored and dense-cored. The cells with small, medium or large secretory granules were all immunoreactive for calcitonin and CGRP. No ultrastructural differences were observed between thyroglobulin-positive and thyroglobulin-negative cases of medullary carcinoma of the thyroid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718620
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  • 28
    Electronic Resource
    Electronic Resource
    Carcinosarcoma of the urinary bladder (1989)
    Springer
    Virchows Archiv 415 (1989), S. 91-95 
    Details
    ISSN: 1432-2307
    Keywords: Carcinosarcoma ; Urinary bladder ; Immunohistochemistry ; Electron microscopy ; Rhabdomyoblast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of urinary bladder carcinosarcoma (UBCS) is reported with light, immunohistochemical and electron microscopical findings. The tumour consisted of a squamous cell carcinoma, variable spindle cell stromal elements compatible with fibrosarcoma, and rhabdomyoblasts. Intermediate filament co-expression of cytokeratin and vimentin was shown by immunohistochemistry. Electron microscopy (EM) confirmed the nature of the three components, and indicated some similarities between the three cell-types present. Comparisons with the previous UBCS in the literature are made.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00718608
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  • 29
    Electronic Resource
    Electronic Resource
    A histopathological study on the prognosis of childhood IgA nephropathy and glomerular basement membrane lesions (1989)
    Springer
    Pediatric nephrology 3 (1989), S. 242-247 
    Details
    ISSN: 1432-198X
    Keywords: IgA nephropathy ; Electron microscopy ; Glomerular basement membrane lesions ; Prognosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Seventy-three patients with IgA nephropathy (IgAGN), under the age of 15 years at the time of the discovery of the disease, were investigated with respect to glomerular basement membrane (GBM) lesions. Irregular attenuation or widening of GBM, especially on the epithelial side, was observed in 28 cases (38%). These two changes are referred to aslysis of GBM and were considered to be the primary and specific changes among the GBM lesions in IgAGN. GBM thickening with layering of lamina densa was found in 37 of 73 cases (51%), but this change has been observed in other types of glomerular diseases. GBM lesions similar to those seen in IgAGN were also observed in Henoch-Schönlein purpura nephritis (HSPN) and poststreptococcal acute glomerulonephritis (PSAGN). Lysis of GBM was observed only in IgAGN, HSPN and PSAGN. Subepithelial and intramembranous deposits appeared to have an important role in the development of these GBM lesions. The presence of GBM lesions was correlated with a high incidence of cellular crescents but not with other clinical or light microscopic findings. The presence of these GBM lesions in IgAGN does not have a significant effect on the prognosis, at least in childhood. The affected GBM seemed to recover without leaving any significant residual damage in most cases. In the long-term prognosis of the disease non-immunological factors, such as ageing or hypertension, seem to be important.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00858523
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  • 30
    Electronic Resource
    Electronic Resource
    Retinal axons innervate the embryonic chick diencephalon in an in-vivo-like pattern in expiant co-cultures (1989)
    Springer
    Experimental brain research 75 (1989), S. 563-568 
    Details
    ISSN: 1432-1106
    Keywords: Retina ; Diencephalon ; Co-culture ; Synapses ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Explants of chick embryo diencephalon co-cultured with explants of retina display areas of complex neuropil containing large retinal-like endings which establish synaptic contact with conventional and presynaptic dendrites. Transection of fibre bundles linking retinal to diencephalic explants results in the degeneration of endings of this type, suggesting that axons of extrinsic (retinal) origin innervate the diencephalic explants in an in-vivo-like manner.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00249907
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  • 31
    Electronic Resource
    Electronic Resource
    A quantitative analysis of the synaptic development of the lobus parolfactorius of the chick (Gallus domesticus) (1989)
    Springer
    Experimental brain research 78 (1989), S. 425-434 
    Details
    ISSN: 1432-1106
    Keywords: Avian forebrain ; Synapses ; Stereology ; Disector ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The lobus parolfactorius (LPO) of the chick has been shown to undergo an increase in the mean synaptic numerical density (Nv syn) in response to one-trial passive avoidance learning (Stewart et al. 1987). The present study was undertaken in order to describe the pattern of normal development of synapses in the LPO, to further investigate the significance of this plastic response. The LPO's from each hemisphere of pre-hatch (16 days), and post-hatch (1 day, 9 day and 22 day old) chicks were processed for electron microscopy. Synapses were classified into asymmetric spine, asymmetric shaft, symmetric spine, and symmetric shaft synapses, on the basis of the density of the post-synaptic thickening and the nature of the post-synaptic target. A 3-dimensional stereological probe was used (the ‘disector’) to calculate Nv syp, and mean projected height (H syp) of the post-synaptic density (PSD). Mean values for each age and hemisphere were compared with a 2-way analysis of variance test using paired samples. A six-fold increase in Nv syp was seen between 16 days in ovo, and 9 days post-hatch. There was a hemispheric asymmetry at 9 days post-hatch, with the left hemisphere LPO containing 1.6 times as many synapses per μm-3. There was a subsequent period of reduction in synaptic density in the left hemisphere LPO between 9 and 22 days post-hatch. The Nv of all classes of synapse increased with age, but the proportions of the symmetrical synapses with respect to the total number of synapses, decreased with age. This decrease was of a similar magnitude for each hemisphere. A hemispheric difference was seen in post-hatch asymmetric synapses, with a greater proportion of asymmetric spine synapses in the left hemisphere. The magnitude of the hemispheric asymmetry was constant throughout the 3 week period of post-hatch development, but was not present in pre-hatch chicks. The PSD increased in length in each hemisphere by approximately 40% between post-hatch day 1 and post-hatch day 9. These data show that the LPO contains a synaptic population which undergoes substantial modification during the first week post-hatch. An asymmetry exists at post-hatch day 9 which is not present at the earlier ages investigated, nor indeed after 22 days post-hatch. This may have significance with regard to studies of passive avoidance learning in the one-day old chick, where an increase in both the size and number of synapses in the LPO has been demonstrated (Stewart et al. 1987). It is possible that ‘training’, in this situation, may simply enhance the timing of synaptic events that result as a consequence of normal development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00228916
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  • 32
    Electronic Resource
    Electronic Resource
    An experimental study of mucociliary pathology of the eustachian tube in otitis media with effusion induced by irradiation (1989)
    Springer
    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 428-432 
    Details
    ISSN: 1434-4726
    Keywords: Otitis media with effusion ; Mucociliary system ; Eustachian tube ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We have examined the function and fine structure of the mucociliary system of the eustachian tube in an experimental study of otitis media with effusion induced by X-ray irradiation. Functional examination demonstrated that the ciliary activity was diminished in such a condition, while morphological observations showed pathological findings including compound cilia, vacuolation of ciliated cells and expansion of intercellular space. These findings show that irradiation-induced otitis media with effusion results in impairment of the mucociliary system. As evidenced by these studies, the mucociliary system in the eustachian tube has an important role in the clearance of fluid produced in the tympanic cavity as well as affording improvement in this disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00464303
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  • 33
    Electronic Resource
    Electronic Resource
    Synovial lining cells (1989)
    Springer
    Rheumatology international 9 (1989), S. 49-51 
    Details
    ISSN: 1437-160X
    Keywords: Synovium ; Monoclonal antibodies ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cells making up the lining of the synovium have long been known as type A and B synoviocytes, with an intermediate form sometimes also described. Accumulating evidence shows that the type A cells are macrophages and the type B cells are fibroblasts. Recently, a definite orientation of these cells within the synovial lining has been observed. The number of synovial lining cells increases in joint disease, and this now seems more likely to be due to cellular recruitment rather than local proliferation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00270244
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  • 34
    Electronic Resource
    Electronic Resource
    Revascularization of isolated autologous bone grafts following microsurgical implantation of arteries and veins (1989)
    Springer
    European journal of plastic surgery 12 (1989), S. 29-34 
    Details
    ISSN: 1435-0130
    Keywords: Revascularization ; Vessel implantation ; Bone grafts ; Corrosion casts ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The microsurgical implantation of a saphenous vascular axis into free transplanted autologous isolated rib segments in Beagle dogs led to complete revascularization of the bone after two, three and four weeks. Indian ink and Mercox-injected specimens showed a vascular network which penetrated the entire cortical layer. Semi-thin sections revealed osteoblasts and osteoclasts visible in the canals of the revascularized cortical layer, while the control specimen without vessel implantation showed nothing but ground substance. The revascularized bones did not contain any necrotic areas. The newly formed vascular system consisted of arteries, veins and their anastomoses. The veins appeared to produce a greater number of new vessels than the arteries.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226918
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  • 35
    Electronic Resource
    Electronic Resource
    Mallomonas alphaphora (Chrysophyceae), a new species from Western Australia (1989)
    Springer
    Plant systematics and evolution 164 (1989), S. 209-214 
    Details
    ISSN: 1615-6110
    Keywords: Algae ; Chrysophyceae (Synurophyceae) ; Mallomonadaceae ; Mallomonas alphaphora ; Electron microscopy ; phytoplankton ; scale-bearing flagellate ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A new species ofMallomonas, M. alphaphora (Chrysophyceae), was found in freshwater ponds in the Perth region, Western Australia. It is distinguished from other species ofMallomonas by its very distinctive scale and bristle morphology and is placed in a new section,Alphaphorae, of the genusMallomonas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00940438
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  • 36
    Electronic Resource
    Electronic Resource
    Immature rat epididymal epithelial cells grown in static primary monolayer culture on permeable supports (1989)
    Springer
    Cell & tissue research 256 (1989), S. 573-580 
    Details
    ISSN: 1432-0878
    Keywords: Epididymis ; Epithelium ; Monolayer culture ; Histochemistry ; Electron microscopy ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary N-acetylglucosaminidase (NAG), acid phosphatase (ACP) and alkaline phosphatase (AKP) were localised histochemically in fixed cells from the 37-day-old rat epididymis grown in static monolayer culture for 2–8 days. ACP and NAG were cytosolic enzymes found in perinuclear positions, whereas staining of AKP was consistent with a membranous position. These enzymes were also examined in frozen tissue sections of the epididymis, from rats of the equivalent age, where NAG had intense activity in both supra- and infra-nuclear cytoplasm and ACP was more active apically. For the first time AKP was localised along basolateral membranes of the epithelium and in the lumen of the mid-caput region. The monolayer in culture was of principal cells only and they maintained their polarity and ultrastructural characteristics, but the height of the cells was reduced compared to that obtained in situ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225606
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  • 37
    Electronic Resource
    Electronic Resource
    Two types of mammosomatotropes in mouse adenohypophysis (1989)
    Springer
    Cell & tissue research 256 (1989), S. 645-648 
    Details
    ISSN: 1432-0878
    Keywords: Mammosomatotropes ; Adenohypophysis ; Electron microscopy ; Immunohistochemistry ; Mouse (SMA)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two types of mammosomatotropes (MS), the small-granule and vesicle-granule MS, were detected in mouse adenohypophysis by electron microscopy and immunohistochemistry. Both cell-types were immunoreactive to prolactin (PRL) and growth hormone (GH) antisera. The small-granule MS contained small, round, solid secretory granules about 100 nm in diameter, and were smaller than the classical GH and PRL cell-types. The vesicle-granule MS contained secretory granules like cored vesicles, and were larger than classical GH and PRL cells. Small-granule MS were immunoreactive to both PRL and GH antisera in the same region of the cell cytoplasm; the vesicle-granule MS, however, were immunoreactive to only PRL antiserum in most cytoplasmic areas, and a positive response to both PRL and GH antisera was confined to only certain small areas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225615
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  • 38
    Electronic Resource
    Electronic Resource
    Localization of cholesterol in the colonic epithelium of the guinea pig: regional differences and functional implications (1989)
    Springer
    Cell & tissue research 258 (1989), S. 339-347 
    Details
    ISSN: 1432-0878
    Keywords: Proximal colon ; Distal colon ; Cholesterol ; Filipin ; Freeze-fracture ; Electron microscopy ; Guinea Pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary It is generally accepted that variations in membrane cholesterol content affect the fluidity of the bilayer, thus altering its permeability. In the biological membranes, in physiological conditions, a high cholesterol content rigidifies the bilayer decreasing its permeability, a lower cholesterol content induces the opposite effect by increasing the permeability. Since differences in the epithelial permeability for short chain fatty acids have previously been demonstrated in the proximal and distal colon of the guinea pig, these two regions were investigated to establish whether differences in membrane cholesterol content of the absorbing cells can be demonstrated. Freeze-fracture replicas of filipin-treated colonic tissue were used. The results show that in the proximal colon the density of filipin cholesterol complexes located on the luminal plasma membrane of the columnar absorbing cells was significantly higher (about twice) than in the distal colon. Therefore the lower amount of cholesterol present in the membrane of the absorbing cells in the distal colon indicates a greater fluidity of the membranes of the epithelial cells in this region. Such fluidity could be correlated to the higher absorption rates of shortchain fatty acids characteristic of this region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239454
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  • 39
    Electronic Resource
    Electronic Resource
    Quantitative electron microscopy of endocrine cells in oxyntic mucosa of normal human stomach (1989)
    Springer
    Cell & tissue research 255 (1989), S. 41-48 
    Details
    ISSN: 1432-0878
    Keywords: Stomach ; Endocrine cells ; Electron microscopy ; Morphometry ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An ultrastructural morphometric study of the endocrine cells of the oxyntic mucosa of the stomach in gastric biopsies collected from five male and five female healthy volunteers aged 19–31 was performed. No sex-related differences were disclosed. Endocrine cells accounted for 1.2±0.4% of the epithelial volume and 0.9±0.4% of the mucosal volume, i.e., including the lamina propria. After classification of the specific endocrine cell types according to the ultrastructural morphology of secretory granules, the volume densities of ECL, P and D cells (30±9%, 24±7%, and 22±4% of the entire endocrine cell mass, respectively) were higher than those of other endocrine cell types. In particular, EC cells contributed less than 10% and X cells represented a very low proportion of the total cells. Non-granulated profiles of cells which in all other respects appeared to be endocrine were also found with a volume density of 8±4%. D cells were distinguished by the high fraction of cytoplasm occupied by secretory granules (31±5%). Subdivision of the whole mucosa into four horizontal segments revealed the endocrine cells to be mostly distributed in the three lower, with virtually no endocrine cells in the superficial segment. The quantitative ultrastructural analysis of the endocrine cell population of the normal human oxyntic mucosa provided by this study may allow a better evaluation of physiological and pharmacological variations of the endocrine cell population.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229064
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  • 40
    Electronic Resource
    Electronic Resource
    Gestational changes in hamster adrenal cortex: Morphometric and ultrastructural stereologic studies (1989)
    Springer
    Cell & tissue research 256 (1989), S. 241-246 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Pregnancy ; Electron microscopy ; Stereology ; Golden hamster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the hamster, the weight of the adrenal glands increases during the course of gestation, with the highest value at day 5. In comparison to non-pregnant control animals, there were no changes in the volume of the zona glomerulosa (ZG) and zona fasciculata (ZF), while the volume of the zona reticularis (ZR) increased notably. The average volume of ZG-cells rose at day 5 of pregnancy and thereafter gradually decreased to that of control hamsters. A marked drop in the volume of ZF-cells was seen at days 5 and 10 of pregnancy, whereas at day 15 the cells were larger than in controls. At day 5 of pregnancy, a conspicuous increase in the cell volume was found in ZR, followed by lower values at day 10 and again higher than in control hamsters at day 15. The total number of parenchymal cells in hamster adrenal cortex increased at day 10 of gestation, then underwent a marked decrease, reaching the control value at the final day of pregnancy; this drop was mainly due to a reduction in the number of ZF-cells. The changes in the cell volume were paralleled by rather proportional changes in the volume of the mitochondrial compartment and in the quantity of smooth endoplasmic reticulum. The volume of the lipid-droplet compartment significantly rose in the course of gestation in both ZF- and ZR-cells. The cortisol output by adrenal homogenates gradually decreased during pregnancy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218881
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    Glomerular podocytes in cultured rat kidney slices (1989)
    Springer
    Cell & tissue research 256 (1989), S. 419-429 
    Details
    ISSN: 1432-0878
    Keywords: Kidney ; Glomerulus ; Podocytes ; Tissue culture ; Electron microscopy ; Morphometry ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of rat glomerular epithelial cells (podocytes) in kidney slices in vitro was examined using qualitative and quantitative electron microscopy. The kidney slices were cultured in Medium 199 with Hanks' salts in a 5% CO2/95% O2 environment for up to 14 days. Few changes in podocyte ultrastructure occurred in the first 12 h of culture, but by 24 h cell bodies were rounded, microvilli were present on all podocyte surfaces, and some foot processes had been replaced by flattened expanses of cytoplasm. These changes were more pronounced by 3 days, when some podocytes had developed pseudopodal extensions and appeared to be migrating from glomeruli onto the slice surface. Podocytes could still be identified after 8, 10 and 14 days of culture, although relatively few glomeruli remained at 14 days. Morphometric methods were used to analyse podocyte shape, volume and surface area during the first 4 days of culture. The most significant change involved loss of foot processes: the number of filtration slits per 100 μm of basement membrane decreased from 211.8 ± 15.0 (mean ± SD) at the commencement of culture, to 55.3 ± 22.6 after 2 days (P 〈 0.001). These data provide baseline information for in vitro studies on the effects of nephrotoxins on podocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218900
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  • 42
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    Nasal lymphoid tissue in the rat (1989)
    Springer
    Cell & tissue research 255 (1989), S. 193-198 
    Details
    ISSN: 1432-0878
    Keywords: Mucosa-associated lymphoid tissue ; Nose ; Lymphoepithelium ; Electron microscopy ; Immunohisto-chemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure and organization of paired lymphoid tissue in the nasal mucosa, situated in the transitional zone on both sides of the septal opening to the pharyngeal duct, of conventionally-housed rats was examined by light microscopy and scanning and transmission electron microscopy. Each lymphoid structure consisted of follicles containing T- and B-cell areas, and was covered with specialized epithelium. This epithelium consisted of cuboidal ciliated cells with oval nuclei parallel to the basal lamina. Goblet cells were sparse. Occasionally, islands of microvilli-bearing cells (so called membraneous or M cells) covered the lymphoid structures. M Cells were also found as single cells among the ciliated cells. The morphological characteristics and the particular localization justify the conclusion that the nasal lymphoid tissue described belongs to the mucosa-associated lymphoid tissue. It is therefore suggested that this nasal structure be designated nasal lymphoid tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229081
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  • 43
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    Immunocytochemical and ultrastructural studies on allografts of the pituitary neurointermediate lobe in the third cerebral ventricle of the rat (1989)
    Springer
    Cell & tissue research 255 (1989), S. 393-404 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Neural lobe ; Intermediate lobe ; Intraventricular graft ; Immunocytochemistry ; Electron microscopy ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neurointermediate lobes from adult or 10-dayold rats were implanted by a stereotaxic procedure into the third ventricle of adult male rats, in an area close to the paraventricular nucleus. They were examined, using immunocytochemical and ultrastructural techniques, at times ranging from 1 week to 8 months. All grafts were recovered in a healthy condition although some rejection of the tissue was detected at the 1and 2-week stages. In the neural lobe, clusters of pituicytes were scattered among the loose network of capillaries, most of which had a fenestrated endothelium. The intermediate lobe remained organized in compact avascular lobules. Axons similar to those projecting into the neurointermediate lobe in situ, but also axons of other types (e.g., somatostatinergic, enkephalinergic) penetrated the grafts. Synapses with melanotrophic cells in the intermediate lobe and neurohaemal contacts in the neural lobe were frequent from 2 1/2 months after transplantation. Immunocytochemical and ultrastructural characteristics indicated intense secretory stimulation of the melanotrophic cells in the early stages. All cells enclosed in a same glandular lobule reacted in a similar manner. In later stages, when re-innervation occurred, the cells recovered their initial characteristics. The overall effect of the re-innervation of the intermediate lobe grafted in this location is inhibitory, as in the lobe in situ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224123
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    Vasoactive intestinal polypeptide (VIP)- and neuropeptide Y (NPY)-containing nerve fibres in the penile cavernous tissue of green monkeys (Cercopithecus aethiops) (1989)
    Springer
    Cell & tissue research 256 (1989), S. 529-541 
    Details
    ISSN: 1432-0878
    Keywords: Penile erection ; Electron microscopy ; Immunohisto(cyto)chemistry ; Vasoactive intestinal polypeptide (VIP) ; Neuropeptide Y (NPY) ; Cercopithecus aethiops (Primates)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cavernous body of green monkeys contains many unmyelinated and few myelinated axons. The unmyelinated axons form terminals in the adventitia of the arteries, between trabecular muscle cells, in the interstitium, and close to endothelium cells of the sinuses. All terminals displayed predominantly “small clear vesicles” and very few “large granular vesicles”; “small granular vesicles” were not seen. However, in rabbit penises, terminals with many large granular vesicles are prominent. Immunohistochemistry (PAP technique) showed a dense network of VIP- and NPY-reactive fibres around the arteries and around trabecular muscles. The density of nerve fibres was particularly high around the subendothelial cushions of the helicine arteries. Double staining for NPY and VIP revealed that both peptides were colocalized. Immunocytochemistry (preembedding PAP technique) showed VIP- and NPY-reactivity in terminals with small clear vesicles; the reaction product was bound to the cytoplasmic face of different membrane types. Although the intracellular localization of the reaction product is probably due to artefactual displacement during preparation, the uniformity of the terminals questions the view that large and small granular vesicles in all species characterize peptidergic and noradrenergic terminals, respectively. The essential findings can be summarized as (1) a high degree of uniformity of nerve terminals, (2) colocalization of VIP and NPY, (3) heavy innervation of the subendothelial cushions of the helicine arteries, and (4) possible innervation of endothelial cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225601
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    Granulated peripolar epithelial cells in the renal corpuscle of marine elasmobranch fish (1989)
    Springer
    Cell & tissue research 257 (1989), S. 61-67 
    Details
    ISSN: 1432-0878
    Keywords: Kidney ; Peripolar cells ; Renal corpuscle ; Electron microscopy ; Raja erinacea, Mustelus canis, Rhinoptera bonasus, Sphryna lewini, Rhizoprionodon terraenovae, Squalus acanthias (Elasmobranchii)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Granulated epithelial cells at the vascular pole of the renal corpuscle, peripolar cells, have been found in the kidneys of five species of elasmobranchs, the little skate (Raja erinaced), the smooth dogfish shark (Mustelus canis), the Atlantic sharpnose shark (Rhizoprionodon terraenovae), the scalloped hammerhead shark (Sphryna lewini), and the cow-nosed ray (Rhinoptera bonasus). In a sixth elasmobranch, the spiny dogfish shark (Squalus acanthias), the peripolar cells could not be identified among numerous other granulated epithelial cells. The peripolar cells are located at the transition between the parietal epithelium of Bowman's capsule and the visceral epithelium (podocytes) of the glomerulus, thus forming a cuff-like arrangement surrounding the hilar vessels of the renal corpuscle. These cells may have granules and/or vacuoles. Electron microscopy shows that the granules are membrane-bounded, and contain either a homogeneous material or a paracrystalline structure with a repeating period of about 18 nm. The vacuoles are electron lucent or may contain remnants of a granule. These epithelial cells lie close to the granulated cells of the glomerular afferent arteriole. They correspond to the granular peripolar cells of the mammalian, avian and amphibian kidney. The present study is the first reported occurrence of peripolar cells in a marine organism or in either bony or cartilagenous fish.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221634
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  • 46
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    Electron-microscopic study on the anterior pituitary gland of spontaneous dwarf rats (1989)
    Springer
    Cell & tissue research 258 (1989), S. 477-482 
    Details
    ISSN: 1432-0878
    Keywords: Anterior pituitary gland ; Electron microscopy ; Growth hormone ; Spontaneous dwarf rats (dr/dr)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The spontaneous dwarf rat is a novel experimental model animal on the study of pituitary dwarfism. The fine structure of the anterior pituitary cells was studied in the immature and mature dwarf rats. Pituitary glands were removed from 5-, 10-, 20-day-old immature dwarfs, adult (45 days-16 weeks) dwarfs and normal 3-month-old rats and processed for electron-microscopic observation. In the control animals, growth hormone cells were readily identified by their ultrastructural characteristics, such as the presence of numerous electron-dense secretory granules, 300–350 nm in diameter, well developed rough endoplasmic reticulum and a prominent Golgi complex. In contrast, growth hormone cells were not found in the anterior pituitary gland of the spontaneous dwarf rat at any age examined. Other pituitary cell types, i.e., luteinizing hormone/ follicle stimulating hormone, thyroid stimulating hormone, adrenocorticotropic hormone and prolactin cells, appeared similar in their fine structure to those found in the control rats. In the pituitary gland of dwarf rats, a number of polygonal cells were observed either with no or relatively few secretory granules. The rough endoplasmic reticulum was arranged in parallel cisternae and the Golgi complex was generally prominent in these cells. In addition, many were found to have abundant lysosomes. A few minute secretory granules were occasionally observed; however, the immunogold technique failed to localize growth hormone or prolactin in the granules. The nature of these cells remained obscure in this study. Since their incidence and fine structural features, other than the secretory granules, were quite similar to those of the growth hormone cells in normal rats, we postulate that these cells are dysfunctional growth hormone cells. These results suggest that the cause of the growth impairment in the spontaneous dwarf rat is due to a defect in the functional growth hormone cells in the pituitary gland, and since other pituitary cell types appeared normal, the disorder seems to be analogous to the isolated growth hormone deficiency in the human.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218859
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  • 47
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    Light- and electron-microscopic investigation of the rat subcommissural organ grafted under the kidney capsule, with particular reference to immunocytochemistry and lectin histochemistry (1989)
    Springer
    Cell & tissue research 258 (1989), S. 499-514 
    Details
    ISSN: 1432-0878
    Keywords: Subcommissural organ ; Secretory activity, neural control ; Transplantation ; Long-spacing collagen ; Immunocytochemistry ; Molecular markers (neuronal, glial) ; Electron microscopy ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary There is increasing evidence that, in the rat, a serotonin-mediated neural input may have an inhibitory influence on the secretory activity of the subcommissural organ (SCO). In the present investigation the rat SCO was studied 7, 30 and 90 days after transplantation under the kidney capsule, an area devoid of local serotonin-containing nerves. The grafted tissue was examined by use of immunocytochemistry employing a series of primary antisera, lectin histochemistry and transmission electron microscopy. The grafted SCO survived transplantation and contained, in addition to secretory ependymal and hypendymal SCO-cells, also elements immunoreactive with antisera against glial fibrillary acidic protein or S-100 protein. In transplants, SCO-cells produced a material displaying the characteristic immunocytochemical and lectin-binding properties of SCO-cells observed under in-situ conditions. The ependymal cells lined 1–3 small cavities, which contained secretory material. A fully developed structural equivalent of Reissner's fiber was, however, never found. The immunocytochemical and ultrastructural study of the grafted SCO showed an absence of nerve fibers within the graft and suggested a state of enhanced secretory activity. A network of protruding basal lamina structures connected the secretory cells to the newly formed capillaries revascularizing the SCO. One week after transplantation, long-spacing collagen started to appear in expanded areas of such laminar networks and also in the perivascular space. It is suggested (i) that the formation of long-spacing forms of collagen is triggered by factors provided by the SCO-secretory cells, and (ii) that secretory material of the ependymal and hypendymal cells may reach the reticular extensions of the basal lamina. In contrast to the SCO in situ, the grafted SCO-cells showed a positive immunoreaction for neuron-specific enolase. They became surrounded by a S-100-immunoreactive glial sheath that separated them from other transplanted cell types and the adjacent kidney tissue of the host.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218862
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    A finite element analysis of the steady laminar entrance flow in a 90° curved tube (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 275-287 
    Details
    ISSN: 0271-2091
    Keywords: Curved pipe flow ; Entrance flow ; Finite element method ; Penalty function method ; Experimental validation ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A standard Galerkin finite element penalty function method is used to approximate the solution of the three-dimensional Navier-Stokes equations for steady incompressible Newtonian entrance flow in a 90° curved tube (curvature ratio δ = 1/6) for a triple of Dean numbers (κ = 41, 122 and 204). The computational results for the intermediate Dean number (κ = 122) are compared with the results of laser-Doppler velocity measurements in an equivalent experimental model. For both the axial and secondary velocity components, fair agreement between the computational and experimental results is found.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090304
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    Masthead (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989) 
    Details
    ISSN: 0271-2091
    Keywords: Engineering ; Engineering General
    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/fld.1650090401
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  • 50
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    Performance of iterative methods for Newtonian and generalized Newtonian flows (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 127-150 
    Details
    ISSN: 0271-2091
    Keywords: Iterative solution ; Viscous flow ; Generalized conjugate gradient ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: We consider the use of accelerated gradient-type iterative methods for solution of Newtonian and certain non-Newtonian (power-law and Bingham models) viscous flow problems. The formulations are based on penalty and mixed finite element methods, and such factors as the effect of the penalty parameter, asymmetry, continuation and preconditioning are examined.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090202
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    Numerical analysis of the developing fluid flow in a circular duct rotating steadily about a parallel axis (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 151-165 
    Details
    ISSN: 0271-2091
    Keywords: Numerical analysis ; Fluid flow ; Rotating circular duct ; Finite cell method ; Finite element method ; Swirl ; Inlet boundary conditions ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A numerical analysis of the flow pattern in the inlet region of a circular pipe rotating steadily about an axis parallel to its own is presented. Both finite cell and finite element methods are used to analyse the problem and they give qualitatively similar results which show that a swirling fluid motion is induced in the pipe inlet region. The analyses show that the direction of swirl is opposite to that of the pipe rotation when viewed along the flow axis and that its magnitude depends on the speed of pipe rotation and throughflow Reynolds number. Neither numerical analysis predicts the marked upturn in friction factor (or pressure drop) which has been observed experimentally. However, a dependence on the pipe inlet boundary conditions is demonstrated.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090203
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    Efficient quadrature for a boundary element method to compute three-dimensional Stokes flow (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 185-191 
    Details
    ISSN: 0271-2091
    Keywords: Stokes equations ; Boundary elements ; Quadrature ; Triangular co-ordinates ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A collocation-type boundary element method based on bilinear B-splines is used for the numerical solution of the Stokes Dirichlet problem in bounded domains D ⊂ R3. The computation of the influence matrix requires the numerical evaluation of weakly singular integrals on the domain boundary if the usual double-layer potential ansatz is chosen. Here mostly standard methods with disjoint grids for collocation and integration are used. We develop a special integration scheme based on triangular co-ordinates near the singularity and show its efficiency compared with the method mentioned above.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090205
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    Effects of grid staggering on numerical schemes (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 193-212 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes ; Staggered grid ; Primitive variable formulation ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Nine finite difference schemes using primitive variables on various grid arrangements were systematically tested on a benchmark problem of two-dimensional incompressible Navier-Stokes flows. The chosen problem is similar to the classical lid-driven cavity flow, but has a known exact solution. Also, it offers the reader an opportunity to thoroughly evaluate accuracies of various conceptual grid arrangements.Compared to the exact solution, the non-staggered grid scheme with higher-order accuracy was found to yield an accuracy significantly better than others. In terms of ‘overall performance’, the so-called 4/1 staggered grid scheme proved to be the best. The simplicity of this scheme is the primary benefit. Furthermore, the scheme can be changed into a non-staggered grid if the pressure is replaced by the pressure gradient as a field variable.Finally, the conventional staggered grid scheme developed by Harlow and Welch also yields relatively high accuracy and demonstrates satisfactory overall performance.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090206
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    A new look at Theodorsen's method in aerofoil theory (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 251-262 
    Details
    ISSN: 0271-2091
    Keywords: Theodorsen's method ; Incompressible flow ; Aerofoil theory ; Thickness ratio ; Camber ratio ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Theodorsen's method for calculating the incompressible potential flow past an aerofoil is viewed afresh. It is found that some simple modifications to the computational process make the computations relatively faster, easier and more accurate. The new modifications are applicable to the analysis of conventional aerofoils with up to moderate thickness and camber ratios. Several examples are presented to show the effectiveness of the modifications.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090302
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    A point implicit unstructured grid solver for the euler and Navier-Stokes equationsBased on a paper originally presented at the AIAA 26th Aerospace Sciences Meeting, Reno, Nevada, January 1988. (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 405-425 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equations ; Euler equations ; Finite element ; Hypersonic laminar-viscous flow ; Time marching ; Shock wave interactions ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: An upwind finite element technique that uses cell-centred quantities and implicit and/or explicit time marching has been developed for computing hypersonic laminar viscous flows using adaptive triangular grids. The approach is an extension to unstructured grids of the LAURA algorithm due to Gnoffo. A structured grid of quadrilaterals is laid out near a solid surface. For inviscid flows the method is stable at Courant numbers of over 100000. A first-order basic scheme and a higher-order flux-corrected transport (FCT) scheme have been implemented. This technique has been applied to the problem of predicting type III and IV shock wave interactions on a cylinder, with a view to simulating the pressure and heating rate augmentation caused by an impinging shock on the leading edge of a cowl lip of an engine inlet. The predictions of wall pressure and heating rates compare very well with experimental data. The flow features are distinctly captured with a sequence of adaptively generated grids.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090404
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    Quantum phenomena in numerical wave propagation (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 623-650 
    Details
    ISSN: 0271-2091
    Keywords: Numerical analysis ; Wave propagation ; Hyperbolic equations ; Quantum mechanics ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The analysis of wave propagation in computing domains where hyperbolic equations are approximated with finite differences has revealed surprising analogies between this subject and quantum mechanics. The first part of this paper consists of a review of the corresponding phenomena and of their description with known results from numerical analysis and wave propagation theory. We then introduce a new formalism, containing a finite difference analogue of the classical Schrodinger equation, which describes the ensemble of those phenomena. The validity of the new formalism is verified by its agreement with known theoretical results in numerical wave propagation (it contains in fact many of those results) as well as with new data obtained in numerical experiments with monochromatic waves which display properties similar to those of Schrödinger's wavefunction for the quantum mechanics description of the equivalent experiments with physical particles. While the results of this paper are derived in the context of wave propagation in computing domains, they remain applicable to similar aspects of wave propagation in other (physical) periodic structures.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090602
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    Numerical study of the axially symmetric motion of an incompressible viscous fluid in an annulus between two concentric rotating spheres (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 689-712 
    Details
    ISSN: 0271-2091
    Keywords: Rotating spheres ; Viscous flow ; Incompressible fluid ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The research reported herein involved the study of the transient motion of a system consisting of an incompressible Newtonian fluid in an annulus between two concentric, rotating, rigid spheres. The primary purpose of the research was to study the use of a numerical method for analysing the transient motion that results from the interaction between the fluid in the annulus and the spheres which are started suddenly by the action of prescribed torques. The problems considered in this research included cases where: (a) one or both spheres rotate with prescribed constant angular velocities and (b) one sphere rotates due to the action of an applied constant or impulsive t̰orque.In this research the coupled solid and fluid equations were solved numerically by employing the finite difference technique. With the approach adopted in this research, only the derivatives with respect to spatial variables were approximated with the use of the finite difference formulae. The steady state problem was also solved as a separate problem (for verification purposes), and the results were compared with those obtained from the solution of the transient problem. Newton's algorithm was employed to solve the algebraic equations which resulted from the steady state problem, and the Adams fourth-order predictor-corrector method was employed to solve the ordinary differential equations for the transient problem. Results were obtained for the streamfunction, circumferential function, angular velocity of the spheres and viscous torques acting on the spheres as a function of time for various values of the system dimensionless parameters.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090604
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    A Newton/upwind method and numerical study of shock wave/boundary layer interactions (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 747-761 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes solutions ; Shock wave/boundary layer interactions ; Newton's iteration ; Upwind differencings ; Symmetric line relaxation ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The objective of the paper is twofold. First we describe an upwind/central differencing method for solving the steady Navier-Stokes equations. The symmetric line relaxation method is used to solve the resulting algebraic system to achieve high computational efficiency. The grid spacings used in the calculations are determined from the triple-deck theory, in terms of Mach and Reynolds numbers and other flow parameters. Thus the accuracy of the numerical solutions is improved by comparing them with experimental, analytical and other computational results. Secondly we proceed to study numerically the shock wave/boundary layer interactions in detail, with special attention given to the flow separation. The concept of free interaction is confirmed. Although the separated region varies with Mach and Reynolds numbers, we find that the transverse velocity component behind the incident shock, which has not been identified heretofore, is also an important parameter. A small change of this quantity is sufficient to eliminate the flow separation entirely.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090702
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    The development of advanced computational methods for turbomachinery blade design (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 921-941 
    Details
    ISSN: 0271-2091
    Keywords: Blade design ; Compressors ; Turbines ; Navier-Stokes ; Quasi-3D and 3D systems ; Through-flow ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The paper describes the basic components of a turbomachinery blade design system in use within Rolls-Royce. A number of modelling aspects of the advanced computational methods in use and under development are reviewed together with areas for future research and development.A quasi-3D blade design system which is used for both compressors and turbines is described covering through-flow and blade-to-blade analysis. Various features of blade-to-blade analysis are discussed including the use of compatible design and analysis modes and coupled boundary layer analysis capable of handling attached and separated flow; examples are included to show capabilities. Advances being made in the development and application of Reynolds-averaged Navier-Stokes models are covered showing capabilities with regard to loss and heat transfer prediction.A fully coupled quasi-3D through-flow and blade-to-blade analysis system is described and results presented to show basic capabilities.The need for 3D flow analysis is discussed and the elements of a 3D blade design system presented showing how this links to the traditional quasi-3D system. Examples are given showing basic capabilities of the methods available and under development.Finally areas for future development are presented indicating the mathematical and numerical modelling problems to be addressed.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090804
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    On TVD difference schemes for the three-dimensional Euler equations in general co-ordinates (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1011-1024 
    Details
    ISSN: 0271-2091
    Keywords: Inviscid flow ; TVD difference scheme ; Shock wave ; Expansion wave ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: An improved treatment for the Harten-Yee and Chakravarthy-Osher TVD numerical flux functions in general co-ordinates is presented. The proposed formulation is demonstrated by a series of numerical experiments for three-dimensional flows around the ONERA-M6 wing. The numerical results indicate that it is important to use a suitable artificial compression parameter in order to obtain more accurate solutions around the leading edge of the wing. The two TVD numerical fluxes give excellent results: they capture the shock wave without numerical oscillations, they capture the rapid expansion around the leading edge sharply, they have self-adjusting mechanisms regarding numerical viscosity and they also have robustness.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090808
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    Analysis of incompressible massively separated viscous flows using unsteady Navier-Stokes equations (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1025-1050 
    Details
    ISSN: 0271-2091
    Keywords: Unsteady Navier-Stokes equations ; Direct solution method ; Block Gaussian elimination ; Backstep channel ; Incompressible separated flow ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The unsteady incompressible Navier-Stokes equations are formulated in terms of vorticity and stream-function in generalized curvilinear orthogonal co-ordinates to facilitate analysis of flow configurations with general geometries. The numerical method developed solves the conservative form of the vorticity transport equation using the alternating direction implicit method, whereas the streamfunction equation is solved by direct block Gaussian elimination. The method is applied to a model problem of flow over a backstep in a doubly infinite channel, using clustered conformal co-ordinates. One-dimensional stretching functions, dependent on the Reynolds number and the asymptotic behaviour of the flow, are used to provide suitable grid distribution in the separation and reattachment regions, as well as in the inflow and outflow regions. The optimum grid distribution selected attempts to honour the multiple length scales of the separated flow model problem. The asymptotic behaviour of the finite differenced transport equation near infinity is examined and the numerical method is carefully developed so as to lead to spatially second-order-accurate wiggle-free solutions, i.e. with minimum dispersive error. Results have been obtained in the entire laminar range for the backstep channel and are in good agreement with the available experimental data for this flow problem, prior to the onset of three-dimensionality in the experiment.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090809
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    Assessment of variants of the k-∊ turbulence model for engine flow applications (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1073-1086 
    Details
    ISSN: 0271-2091
    Keywords: k-∊ turbulence model ; Compressible flow ; Bulk dilatation ; Reciprocating engine flow ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: This paper is concerned with simulation of the mean flow and turbulence evolution in a model engine and comparison of the behaviour of certain important turbulence parameters, namely the intensity, length scale and dissipation time scale, as predicted by three variants of the k-∊ model developed for application to strongly compressible flows. The predictions pertain to the axisymmetric, disc-chamber, four-stroke, Imperial College model engine operating at 200 rpm and compression ratios of 3·5 and 6·7. The paper analyses the predicted variations of these parameters during the induction, compression and expansion strokes and identifies the versions that produce the most consistent and physically plausible variations. The significance, to the turbulence evolution, of the ratio of the turbulence dissipation time scale to the time scale of compression/expansion is also discussed. It is concluded that on these grounds the Morel-Mansour and El Tahry versions are, and the Watkins version is not, suitable for engine applications.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090903
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    Algebraic turbulence models for the computation of two-dimensional high-speed flows using unstructured grids (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1121-1143 
    Details
    ISSN: 0271-2091
    Keywords: Turbulence ; High-speed flows ; Unstructured grids ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The incorporation of algebraic turbulence models in a solver for the 2D compressible Navier-Stokes equations using triangular grids is described. A practical way to use the Cebeci-Smith model and to modify it in separated regions is proposed. The ability of the model to predict high-speed perfect-gas boundary layers is investigated from a numerical point of view.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090907
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    Conference diary (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1179-1182 
    Details
    ISSN: 0271-2091
    Keywords: Engineering ; Engineering General
    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/fld.1650090910
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    A boundary element method for a non-linear free surface problem (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1195-1206 
    Details
    ISSN: 0271-2091
    Keywords: Free boundary problem ; Potential flow ; Wave resistance ; BEM ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: In this paper a numerical method to compute the wave resistance of a body submerged in a free stream of finite and infinite depth is presented. Non-linear effects on the free surface are taken into account by an iterative procedure; the solution is in the form of a single-layer potential. For the 2D problem, results are shown for both the cases of finite and infinite depth of the fluid domain, with special emphasis on the supercritical flow in which the consistency of the scheme is pointed out. The method is also extended to the 3D case of a spheroid submerged in deep water. All the results presented are compared with experimental data and analytical solutions available in the literature.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650091003
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    On the application of pseudospectral FFT techniques to non-periodic problems (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1235-1267 
    Details
    ISSN: 0271-2091
    Keywords: Pseudospectral ; Non-periodic ; Incompressible flows ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The reduction-to-periodicity method using the pseudospectral fast Fourier transform (FFT) technique is applied to the solution of non-periodic problems, including the two-dimensional incompressible Navier-Stokes equations. The accuracy of the method is explored by calculating the derivatives of given functions, one- and two-dimensional convective-diffusive problems, and by comparing the relative errors due to the FFT method with a second-order finite difference (FD) method. Finally, the two-dimensional Navier-Stokes equations are solved by a fractional step procedure using both the FFT and the FD methods for the driven cavity flow and the backward-facing step problems. Comparisons of these solutions provide a realistic assessment of the FFT method.
    Additional Material: 26 Ill.
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    URL: http://dx.doi.org/10.1002/fld.1650091006
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    An efficient algorithm for compressible flows with real gases (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1269-1283 
    Details
    ISSN: 0271-2091
    Keywords: Euler equations ; Real gases ; Local parametrization of the equation of state ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: An efficient algorithm is presented for the solution of the Euler equations of gas dynamics with a general convex equation of state. The scheme is based on solving linearized Riemann problems approximately, and in more than one dimension incorporates operator splitting. In particular, only one function evaluation in each computational cell is required by using a local parametrization of the equation of state. The scheme is applied to two standard test problems in gas dynamics for some specimen equations of state.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650091007
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    A fast riemann solver with constant covolume applied to the random choice method (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1145-1164 
    Details
    ISSN: 0271-2091
    Keywords: Riemann problem ; Covolume ; Random choice ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The Riemann problem for the unsteady one-dimensional Euler equations together with the constant-covolume equation of state is solved exactly. The solution is then applied to the random choice method to solve the general initial-boundary value problem for the Euler equations. The iterative procedure to find p*, the pressure between the acoustic waves, involves a single algebraic (non-linear) equation, all other quantities follow directly throughout the x-t plane, except within rarefaction fans where an extra iterative procedure is required. The solution is validated against existing exact results both directly and in conjunction with the random choice method.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090908
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    Masthead (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989) 
    Details
    ISSN: 0271-2091
    Keywords: Engineering ; Engineering General
    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/fld.1650091001
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    An investigation of pressure transients in pipelines with two-phase bubbly flow (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1207-1219 
    Details
    ISSN: 0271-2091
    Keywords: Centre implicit method ; Pressure transients ; Two-phase pipe flow ; Bubbly pipe flow ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: This paper presents a two-dimensional model for the analysis of the pressure transient of a two-phase homogeneous bubbly mixture flowing in a pipeline and the numerical integration using the centre implicit method (CIM). Experiments were conducted to confirm the proposed sonic speed equation of an air-water mixture for an air concentration of less than 1%. The 2D CIM model is compared with the method of characteristics (MoC) for a two-phase bubbly flow in a pipeline. The comparisons show that the proposed 2D CIM model generally gives good agreement with the method of characteristics.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650091004
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    Comment on ‘generalized potential flow theory and direct calculation of velocities applied to the numerical solution of the Navier-Stokes and the Boussinesq equations’ (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1299-1301 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equation ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: In a recent paper a generalized potential flow theory and its application to the solution of the Navier-Stokes equation are developed.1 The purpose of this comment is to show that the analysis presented in that paper is in general not correct. We note that the theoretical development of Reference 1 is in fact an extension - although not cited - of some work first done by Hawthorne for steady inviscid flow.2 Hawthorne's solution is correct, and his analysis, which we briefly describe, provides a useful introduction to this note.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650091009
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    Masthead (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989) 
    Details
    ISSN: 0271-2091
    Keywords: Engineering ; Engineering General
    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/fld.1650091101
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    Convergence properties of high-Reynolds-number separated flow calculations (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1395-1411 
    Details
    ISSN: 0271-2091
    Keywords: Reduced Navier-Stokes computations ; Flow separation ; Laminar instability ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The convergence properties of an iterative solution technique for the Reduced Navier-Stokes equations are examined for two-dimensional steady subsonic flow over bump and trough geometries. Techniques for decreasing the sensitivity to the initial pressure approximation, for fine meshes in particular, are investigated. They are shown to improve the robustness of the relaxation process and to decrease the computational work required to obtain a converged solution. A semi-coarsening multigrid technique that has previously been found to be particularly advantageous for high-Reynolds-number (Re) flows with flow separation and with highly stretched surface-normal grids is applied herein to further accelerate convergence. Solutions are obtained for the laminar flow over a trough that is more severe than has been considered to date. Sufficient axial grid refinement in this case leads to a shock-like reattachment and, for sufficiently large Re, to a local ‘divergence’ of the numerical computations. This ‘laminar flow breakdown’ appears to be related to an instability associated with high-frequency fine-grid modes that are not resolvable with the present modelling. This behaviour may be indicative of dynamic stall or of incipient transition. The breakdown or instability is shown to be controllable by suitable introduction of transition turbulence models or by laminar flow control, i.e. small amounts of wall suction. This lends further support to the hypothesis that the instability is of a physical rather than numerical character and suggests that full three-dimensional analysis is required to properly capture the flow behaviour. Another inference drawn from this investigation is that there is a need for careful grid refinement studies in high-Re flow computations, since coarser grids may yield oscillation-free solutions that cannot be obtained on finer grids.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650091108
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    Variations on Fourier wave theory (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1453-1467 
    Details
    ISSN: 0271-2091
    Keywords: Fourier wave theory ; Limit wave ; Stream function ; Truncation order ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A review of the analytical and numerical background of Fourier wave theory establishes the commonality of existing formulations and identifies a number of analytical and numerical assumptions that are unnecessary. Some formulations in particular lack flexibility in excluding the possibility of Stokes' second definition of phase speed. A generalized formulation is introduced for comparative purposes and it is shown that published solutions differ only in the approach to the limit wave. Detailed consideration of truncation order confirms that it is the crucial parameter, especially at extreme wave heights. All formulations considered are shown to provide acceptable solutions for small to moderately extreme waves.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650091203
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    A finite element analysis of laminar unsteady flow of viscoelastic fluids through channels with non-uniform cross-sections (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1487-1501 
    Details
    ISSN: 0271-2091
    Keywords: Viscoelastic fluid ; Polymer flow ; Velocity correction method ; Two-step explicit scheme ; Pressure boundary condition ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The effects of non-Newtonian behaviour of a fluid and unsteadiness on flow in a channel with non-uniform cross-section have been investigated. The rheological behaviour of the fluid is assumed to be described by the constitutive equation of a viscoelastic fluid obeying the Oldroyd-B model. The finite element method is used to analyse the flow. The novel features of the present method are the adoption of the velocity correction technique for the momentum equations and of the two-step explicit scheme for the extra stress equations. This approach makes the computational scheme simple in algorithmic structure, which therefore implies that the present technique is capable of handling large-scale problems. The scheme is completed by the introduction of balancing tensor diffusivity (wherever necessary) in the momentum equations. It is important to mention that the proper boundary condition for pressure (at the outlet) has been developed to solve the pressure Poisson equation, and then the results for velocity, pressure and extra stress fields have been computed for different values of the Weissenberg number, viscosity due to elasticity, etc. Finally, it is pertinent to point out that the present numerical scheme, along with the proper boundary condition for pressure developed here, demonstrates its versatility and suitability for analysing the unsteady flow of viscoelastic fluid through a channel with non-uniform cross-section.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650091205
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    Momentum transport in a turbulent mixing layer (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 23-41 
    Details
    ISSN: 0271-2091
    Keywords: Momentum transport ; Turbulent mixing layers ; Discrete vortex method ; Time-dependent momentum fluctuations ; Comparison with experiments ; Large-scale structures ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The turbulent momentum transport phenomena in a two-dimensional mixing layer are investigated numerically by a discrete vortex method. The numerical model and calculations are verified through a comparison with existing numerical simulations and experimental measurements. The main emphasis is placed on the exploration of the detailed time-dependent instantaneous local momentum fluctuations and on the comparison of numerical results with available experimental measurements. The current simulations confirm qualitatively the various trends in the turbulent momentum flux and fluctuating components of the velocity in the mixing layer found with several experimental results. The study shows that similarity exists in turbulent momentum quantities along the axial direction of the mixing layer. The calculations also show a definite correlation between the passage of a large-scale structure and a burst in the turbulent momentum flux. The probability density functions of the fluctuating quantities are shown to be mostly Gaussian-like, with only a few exceptions.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090104
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    Comparison with experiment for TVD calculations of blast waves from a shock tube (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 9-22 
    Details
    ISSN: 0271-2091
    Keywords: Shock capturing ; Shock tube ; TVD scheme ; Compressible flow ; Fluid dynamics ; Comparison with experiment ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Harten's second-order-accurate total-variation-diminishing (TVD) scheme is applied to calculation of flow from the open end of a shock tube. Comparison of numerical results with available experimental data for overpressure at selected points around the shock tube exit shows good agreement. Numerically indicated positions of the moving shock front and Mach stem also compare well with flow shadowgraph data. Where the problem geometry is sufficiently simple and rectangular gridding can be used, Harten's method affords a good choice for blast wave calculations.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090103
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    Euler flow solutions for transonic shock wave-boundary layer interaction (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 59-73 
    Details
    ISSN: 0271-2091
    Keywords: Steady Euler equations ; Transonic flows ; Multigrid methods ; Boundary conditions ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Steady 2D Euler flow computations have been performed for a wind tunnel section, designed for research on transonic shock wave-boundary layer interaction. For the discretization of the steady Euler equations, an upwind finite volume technique has been applied. The solution method used is collective, symmetric point Gauss-Seidel relaxation, accelerated by non-linear multigrid. Initial finest grid solutions have been obtained by nested iteration. Automatic grid adaptation has been applied for obtaining sharp shocks. An indication is given of the mathematical quality of four different boundary conditions for the outlet flow. Two transonic flow solutions with shock are presented: a choked and a non-choked flow. Both flow solutions show good shock capturing. A comparison is made with experimental results.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090106
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    A multigrid method for steady incompressible Navier-Stokes equations based on partial flux splitting (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 113-120 
    Details
    ISSN: 0271-2091
    Keywords: Steady Navier-Stokes equations ; Partial flux splitting ; Multigrid methods ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Flux splitting is applied to the convective part of the steady Navier-Stokes equations for incompressible flow. Partial upwind differences are introduced in the split first-order part, while central differences are used in the second-order part. The discrete set of equations obtained is positive, so that it can be solved by collective variants of relaxation methods. The partial upwinding is optimized in the same way as for a scalar convection-diffusion equation, but involving several Peclet numbers. It is shown that with the optimum partial upwinding accurate results can be obtained. A full multigrid method in W-cycle form, using red-black successive under-relaxation, injection and bilinear interpolation, is described. The efficiency of this method is demonstrated.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090109
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    Numerical simulation of axisymmetric turbulent flow in combustors and diffusers (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 167-183 
    Details
    ISSN: 0271-2091
    Keywords: Axisymmetric turbulent flow ; Combustors ; Diffusers ; Navier-Stokes equations k-∊ model ; Zonal grid ; Finite differences ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Numerical studies of turbulent flow in an axisymmetric 45° expansion combustor and bifurcated diffuser are presented. The Navier-Stokes equations incorporating a k-∊ model were solved in a non-orthogonal curvillinear co-ordinate system. A zonal grid method, wherein the flow field was divided into several subsections, was developed. This approach permitted different computational schemes to be used in the various zones. In addition, grid generation was made a more simple task. However, treatment of the zonal boundaries required special handling. Boundary overlap and interpolating techniques were used and an adjustment of the flow variables was required to assure conservation of mass flux. Three finite differencing methods - hybrid, quadratic upwind and skew upwind - were used to represent the convection terms. Results were compared with existing experimental data. In general, good agreement between predicted and measured values was obtained.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090204
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  • 81
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    Process splitting of the boundary conditions for the advection-dispersion equation (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 235-244 
    Details
    ISSN: 0271-2091
    Keywords: Process splitting ; Advection-dispersion equation ; Boundary conditions ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Rational strategies are considered for the specification of the intermediate boundary condition at an inflow boundary where process splitting (fractional steps) is adopted in solving the advection-dispersion equation. Three lowest-order methods are initially considered and evaluation is based on comparisons with an analytical solution. For flow and dispersion parameter ranges typical of rivers and estuaries, the given boundary condition for the complete advection-dispersion equation at the end of the complete time step provides a satisfactory estimate of the intermediate boundary value. This was further confirmed by the development and evaluation of two higher-order methods. These required non-centred discrete approximations for spatial derivatives, which offset any special advantages from the higher truncation error order.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090208
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  • 82
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    Announcements (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 250-250 
    Details
    ISSN: 0271-2091
    Keywords: Engineering ; Engineering General
    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/fld.1650090210
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  • 83
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    Numerical simulation of the hydrodynamic interaction between a sedimenting particle and a neutrally buoyant particle (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 263-273 
    Details
    ISSN: 0271-2091
    Keywords: Low-Reynolds-number flow ; Sedimentation ; Hydrodynamic interactions ; Two-phase flows ; Suspensions ; Boundary element method ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A new method for the simulation of the translational and rotational motions of a system containing a sedimenting particle interacting with a neutrally buoyant particle has been developed. The method is based on coupling the quasi-static Stokes equations for the fluid with the rigid body equations of motion for the particles. The Stokes equations are solved at each time step with the boundary element method. The stresses are then integrated over the surface of each particle to determine the resultant forces and moments. These forces and moments are inserted into the rigid body equations of motion to determine the translational and rotational motions of the particles. Unlike many other simulation techniques, no restrictions are placed on the shape of the particles. Superparametric boundary elements are employed to achieve accurate geometric representations of the particles. The simulation method is able to predict the local fluid velocity, resolve the forces and moments exerted on the particles, and track the particle trajectories and orientations.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090303
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  • 84
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    Conference diary (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 369-373 
    Details
    ISSN: 0271-2091
    Keywords: Engineering ; Engineering General
    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/fld.1650090310
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  • 85
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    Numerical simulation of silencers (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 363-368 
    Details
    ISSN: 0271-2091
    Keywords: Silencers ; Noise attenuation ; Shock flow ; Numerical simulation ; Gas dynamics ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The problem of attenuating the noise from weapons firing is studied experimentally and numerically. As a possible method of attenuating the noise significantly, a silencer with no internal baffles is attached to the M242 cannon. The internal pressures inside the muffler are measured. The near-field overpressures outside the muffler at various polar angles are also measured. A numerical simulation of the flow through the muffler is performed, using Harten's shock-capturing method to solve the Euler equations of ideal compressible flow. The numerical simulation yields a detailed picture of the flow field as displayed by the pressure and Mach contours. Pressure-time curves at selected locations are obtained and compared with experimental data. There is good agreement, except that the numerical simulation generates more vigorous oscillations.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090309
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  • 86
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    Three-dimensional unsteady flow simulations: Alternative strategies for a volume-averaged calculation (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 341-362 
    Details
    ISSN: 0271-2091
    Keywords: Unsteady ; Fluid flow ; Navier-Stokes ; Simulation ; SIMPLE ; PRIME ; QUICK ; ICCG ; MG ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: This work builds on a SIMPLE-type code to produce two numerical codes of greatly improved speed and accuracy for solution of the Navier-Stokes equations. Both implicit and explicit codes employ an improved QUICK (quadratic upstream interpolation for convective kinematics) scheme to finite difference convective terms for non-uniform grids. The PRIME (update pressure implicit, momentum explicit) algorithm is used as the computational procedure for the implicit code. Use of both the ICCG (incomplete Cholesky decomposition, conjugate gradient) method and the MG (multigrid) technique to enhance solution execution speed is illustrated. While the implicit code is first-order in time, the explicit is second-order accurate. Two- and three-dimensional forced convection and sidewall-heated natural convection flows in a cavity are chosen as test cases. Predictions with the new schemes show substantial computational savings and very good agreement when compared to previous simulations and experimental data.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090308
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  • 87
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    Announcement (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 374-374 
    Details
    ISSN: 0271-2091
    Keywords: Engineering ; Engineering General
    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/fld.1650090311
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  • 88
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    Three-dimensional reduced Navier-Stokes solutions for subsonic separated and non-separated flows, using a global pressure relaxation procedure (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1087-1098 
    Details
    ISSN: 0271-2091
    Keywords: RNS ; Separation ; Direct solver ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The reduced Navier-Stokes and thin layer approximations to the Navier-Stokes equations are used to obtain solutions for viscous subsonic three-dimensional flows. A spatial marching method is combined with a direct sparse matrix solver to obtain successive solutions in a global relaxation process. Results have been obtained for flow fields with and without regions of flow reversal.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090904
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  • 89
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    A velocity formulation for flow past a symmetric profile with a wake (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1113-1119 
    Details
    ISSN: 0271-2091
    Keywords: Finite element ; Free streamlines ; Wakes ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A model having velocity components as basic unknowns is presented for calculation of two-dimensional flow past a symmetric profile with a wake in a channel. A modified least squares functional is used for the finite element solution of velocities. The determination of the position of the free streamline is treated as an optimum design problem. The concepts of cost function, geometry parameter and sensitivity derivative are employed. Numerical results are compared with published results obtained with streamfunction formulations.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090906
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  • 90
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    Laminar flow and heat transfer over a two-dimensional triangular step (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1165-1177 
    Details
    ISSN: 0271-2091
    Keywords: Laminar flow ; Triangular step ; FEM ; Velocity correction ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The velocity correction algorithm is used in the finite element method to solve forced convection problems between parallel plates with a triangular step, for Reynolds numbers up to 1000. Equal-order interpolation functions for velocity, pressure and temperature are used. The solutions show a smooth variation of pressure. The streamfunction, isotherms, isobars and velocity profiles are presented for a typical Reynolds number of 500. The skin friction and heat transfer results are presented for Reynolds numbers up to 1000.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090909
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  • 91
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    Numerical solution of transonic flows on a streamfunction co-ordinate system (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1183-1193 
    Details
    ISSN: 0271-2091
    Keywords: CFD ; Transonics ; Streamfunction co-ordinates ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A new method has been developed for the computation of steady two-dimensional full-potential transonic flow past symmetric aerofoils. This method utilizes von Mises variables (x, ψ), where ψ is taken as the streamfunction for the flow. The flow equations and appropriate boundary conditions are formulated in terms of the von Mises variables (x, ψ) for symmetric aerofoils at zero incidence. This yields a system of two equations for unknowns ρ(x, ψ) and y(x, ψ). Finite difference solutions have been computed using SLOR at subcritical and supercritical Mach numbers. The results are compared with available data and are in excellent agreement.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650091002
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  • 92
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    Electronic Resource
    The simple layer potential method of fundamental solutions for certain biharmonic problems (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1221-1234 
    Details
    ISSN: 0271-2091
    Keywords: Biharmonic equation ; Stokes flow ; Simple layer potential ; Method of fundamental solutions ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A novel formulation of the method of fundamental solutions for the numerical solution of plane biharmonic problems, based on the simple layer potential representation of Fichera, is presented. The applicability and accuracy of the method are demonstrated by examining its performance on a set of practical problems arising in Stokes fluid flow.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650091005
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  • 93
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    Vorticity - velocity formulation in the computation of flows in multiconnected domains (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1285-1298 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equations ; Vorticity-velocity ; Multiconnected domains ; Pressure single-valuedness ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The thermofluid dynamic fields in two-dimensional multiconnected domains are analysed by solving the Navier-Stokes equations with the Boussinesq approximation in the vorticity-velocity formulation. The need of an integral condition for the pressure to be single-valued on each independent irreducible loop, in analogy with the ω-Ψ formulation, is demonstrated. The field equations are discretized by a finite difference technique and solved at the steady state via an alternating direction implicit method of a scalar type. Two test cases at low Reynolds and Rayleigh numbers are considered: the multiconnected driven cavity and an annulus with isothermal walls and stationary or rotating inner cylinder.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650091008
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  • 94
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    Comments on a recent paper by W. Zijl (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1302-1304 
    Details
    ISSN: 0271-2091
    Keywords: Incompressible flow ; Clebsch potentials ; Three-dimensional ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A recent paper by W. Zijl, which reformulated the Navier-Stokes and Boussinesq equations in terms of Clebsch potentials, has an error that greatly reduces the generality of the results. Some other recent efforts to use such potentials in fluid and plasma dynamics are briefly discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650091010
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  • 95
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    A finite element analysis of a free surface drainage problem of two immiscible fluids (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 569-582 
    Details
    ISSN: 0271-2091
    Keywords: Flow analysis ; Free surface problem ; Finite element method ; Blast furnace ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A sharp interface problem arising in the flow of two immiscible fluids, slag and molten metal in a blast furnace, is formulated using a two-dimensional model and solved numerically. This problem is a transient two-phase free or moving boundary problem, the slag surface and the slag-metal interface being the free boundaries. At each time step the hydraulic potential of each fluid satisfies the Laplace equation which is solved by the finite element method. The ordinary differential equations determining the motion of the free boundaries are treated using an implicit time-stepping scheme. The systems of linear equations obtained by discretization of the Laplace equations and the equations of motion of the free boundaries are incorporated into a large system of linear equations. At each time step the hydraulic potential in the interior domain and its derivatives on the free boundaries are obtained simultaneously by solving this linear system of equations. In addition, this solution directly gives the shape of the free boundaries at the next time step. The implicit scheme mentioned above enables us to get the solution without handling normal derivatives, which results in a good numerical solution of the present problem. A numerical example that simulates the flow in a blast furnace is given.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090507
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  • 96
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    Navier-Stokes computation of transonic vortices over a round leading edge delta wing (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 943-962 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes solver ; Vortex motion ; Finite volume method ; Viscous flow ; Delta wing ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A 3D Navier-Stokes solver has been developed to simulate laminar compressible flow over quadrilateral wings. The finite volume technique is employed for spatial discretization with a novel variant for the viscous fluxes. An explicit three-stage Runge-Kutta scheme is used for time integration, taking local time steps according to the linear stability condition derived for application to the Navier-Stokes equations. The code is applied to compute primary and secondary separation vortices at transonic speeds over a 65° swept delta wing with round leading edges and cropped tips. The results are compared with experimental data and Euler solutions, and Reynolds number effects are investigated.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090805
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  • 97
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    Finite element technique to solve the elastic strain for Leonov fluid flow (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1059-1072 
    Details
    ISSN: 0271-2091
    Keywords: Viscoelastic flow ; Leonov model ; Convective integration ; Finite element method ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The finite element method is used to find the elastic strain (and thus the stress) for given velocity fields of the Leonov model fluid. With a simple linearization technique and the Galerkin formulation, the quasi-linear coupled first-order hyperbolic differential equations together with a non-linear equality constraint are solved over the entire domain based on a weighted residual scheme. The proposed numerical scheme has yielded efficient and accurate convective integrations for both the planar channel and the diverging radial flows for the Leonov model fluid. Only the strain in the inflow plane is required to be prescribed as the boundary conditions. In application, it can be conveniently incorporated in an existing finite element algorithm to simulate the Leonov viscoelastic fluid flow with more complex geometry in which the velocity field is not known a priori and an iterative procedure is needed.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650090902
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  • 98
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    Numerical studies of slow viscous rotating flow past a sphere. III (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1321-1329 
    Details
    ISSN: 0271-2091
    Keywords: Peaceman-Rachford ADI method ; Method of sweeps ; Central differences of o(h2; k2) ; Rotating viscous fluid ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The flow of steady incompressible viscous fluid rotating about the z-axis with angular velocity ω and moving with velocity u past a sphere of radius a which is kept fixed at the origin is investigated by means of a numerical method for small values of the Reynolds number Reω. The Navier-Stokes equations governing the axisymmetric flow can be written as three coupled non-linear partial differential equations for the streamfunction, vorticity and rotational velocity component. Central differences are applied to the partial differential equations for solution by the Peaceman-Rachford ADI method, and the resulting algebraic equations are solved by the ‘method of sweeps’.The results obtained by solving the non-linear partial differential equations are compared with the results obtained by linearizing the equations for very small values of Reω. Streamlines are plotted for Ψ = 0·05, 0·2, 0·5 for both linear and non-linear cases. The magnitude of the vorticity vector near the body, i.e. at z = 0·2, is plotted for Reω = 0·05, 0·24, 0·5. The correction to the Stokes drag as a result of rotation of the fluid is calculated.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650091103
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  • 99
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    Numerical simulation of an impinging jet on a flat plate (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989), S. 1413-1426 
    Details
    ISSN: 0271-2091
    Keywords: Impinging jet ; MacCormack implicit scheme ; Implicit bidiagonal numerical method ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Two-dimensional normal impinging jet flowfields, with or without an upper plate, were analysed by employing an implicit bidiagonal numerical method developed by Lavante and Thompkins Jr. The Jones-Launder K-∊ two-equation turbulent model was employed to study the turbulent effects of the impinging jet flowfield. The upper plate surface pressure, the ground plane pressure and other physical parameters of the momentum flowfield were calculated at various jet exit height and jet inlet Reynolds numbers. These results were compared with those of Beam and Warming's numerical method, Hsiao and Chuang, and others, along with experimental data. The potential core length of the impinging jet without an upper plate is longer than that of the free jet because of the effects of the ground plane, while the potential core length of the impinging jet with an upper plate is shorter than that of the free jet because of the effects of the upper plate. This phenomenon in the present analysis provides a fundamental numerical study of an impinging jet and a basis for further analysis of impinging jet flowfields on a variable angle plate.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650091109
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  • 100
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    Masthead (1989)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 9 (1989) 
    Details
    ISSN: 0271-2091
    Keywords: Engineering ; Engineering General
    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/fld.1650091201
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