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  • 1980-1984
  • 1965-1969  (734)
  • 1920-1924
  • 1967  (734)
  • Cell & Developmental Biology  (422)
  • Chemical Engineering  (312)
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Years
  • 1980-1984
  • 1965-1969  (734)
  • 1920-1924
Year
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 121 (1967) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: An electron microscope study of oocyte maturation in the mouse revealed that some mitochondria undergo gradual transformation in their ultrastructural appearance. In very young oocytes these mitochondria were already found to contain vacuoles, one in each such organelle. In somewhat older oocytes more mitochondria displayed vacuoles which generally appeared to be getting larger. These intramitochondrial vacuoles were found to be essentially optically empty structures surrounded by a single membrane. In favorable sections someof the developing vacuoles had a bottle-shaped appearance, the constricted end of which was attached to the inner limiting membrane of the mitochondrion. With further maturation of the oocytes vacuoles having a pear-shaped appearance became evident. An hypothesis was presented outlining the mode of formation of these vacuoles by expansion of the individual cristae. Intramitochondrial transformations occuring during both oogenesis and spermatogenesis in mammals were reviewed.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 121 (1967), S. 103-133 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The monotypic perciform suborder Luciocephaloidei possesses the following, previously unknown, salient morphological characters: a third joint, the nasopalatopterygoid, between neurocranium and suspensorium; a toothless and dorsally exposed prevomer; no pharyngeal processes on either parasphenoid or basioccipital; a tympanum-covered foramen exoccipitale in the saccular bulla as a hearing organ; a gular ossification; a craniovertebral joint with small exoccipital condyles widely separated from the basioccipital condyle; and a large physoclystic swimbladder with a notable caudal extension. The seemingly functionless gular-like mental ossification is considered a paleomorphic structure with a neogenetic development. Attenuation in longitudinal growth is evident in the derivatives and dermal additions of the mandibular arch and nasal capsule while other regions of the head have remained independent. The primary adaptive significance of the attenuation in the growth of the entire preorbital region is the accomodation of oral incubation. Secondarily the elongate jaws increase both the speed and grasping range of the bite in prey catching. The degree of jaw protrusion depends mainly on the length of the maxillary. The exaggerated length of the ascending processes of the premaxillaries may be the result of a positive differential growth rate within one growth field. The meaning of the preponderance of parallel-fibered cranial muscles is discussed in respect to holding functions, greatest possible excursion of the insertion with minimum loss of force, and muscle fiber length. Based on the overall morphology, the monotypic suborder Luciocephaloidei is retained.
    Additional Material: 23 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 121 (1967), S. 135-157 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Osteology, myology and motion analysis of the head of the anabantoid fish Helostoma temmincki, a specialized filter feeder, has revealed six functional units: neurocranium, suspensory apparatus, opercular apparatus, hyoid apparatus, branchial apparatus and pectoral girdle. Interactions between the functional units take place through four couplings involved in opening and protruding the jaws. The first coupling is activated in the beginning of the opening cycle by the levator operculi muscle through the opercular apparatus, interoperculomandibular ligament and mandible. The second is activated during feeding by contraction of the sternohyoideus through the hyoid apparatus, interopercular, interoperculomandibular ligament and mandible. The third coupling is active during feeding and “kissing” by contraction of epaxial muscles through mediation of the neurocranium to the jaw apparatus. The fourth coupling is the only one active during air intake and involves contraction of the levator arcus palatini which abducts and rotates the suspensory apparatus forwards, causing the mandible to drop. The retention of isolated ancestral characters during mosaic evolution are explained in terms of the maintenance of couplings which represent functional associations of seemingly remote structures. When natural selection acts on one component of a functional unit or coupling, it essentially acts on all associated elements simultaneously causing character complexes to evolve in common evolutionary trends. It is feasible that functional analysis can separate primary from secondary evolutionary trends.
    Additional Material: 12 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 122 (1967), S. 89-114 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Large dogs are able to deliver a powerful bite that generates considerable stress in the anterior, prehensile part of the jaws.In the upper jaw most of the biting force is borne by the anterior teeth. The palatal mucosa provides little resistance to deformation. It is easily compressed and rather mobile.In the lower jaw, the mucosa covering the upper surface of the symphysis receives a sizeable portion of the biting force. It is firmly attached to the underlying bone and possesses special connective tissue arrangements that enable it to transduce locally applied pressure to tension distributed over a broad area.
    Additional Material: 21 Ill.
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  • 6
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Goldfish testes were nutritionally regressed in about 115 days regardless of season and without controlled light or temperature. A gonosomatic index (testes weight ″ 100/body weight) of the regressed fish was about one tenth that of spawning fish. The regressed testes were primarily composed of spermatogonia, spermatocytes, and connective tissue. Fish testes were maintained in a regressed state for over 200 days with no change in gonosomatic index. Fish with regressed testes appeared to be in a state of “pseudohypophysectomy” with respect to gonadotropin. Pituitary replacement and a diet of 5% of the body weight per day initiated spermatogenesis and brought the regressed testes to functional maturity in one month. The results suggest that spermatogonial proliferation and the maturation of sperm have different regulatory requirements.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 123 (1967), S. 1-16 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A theoretical analysis is made of the mechanical advantages of exoskeletons and endoskeletons. More complicated and realistic loading systems are considered than have been by previous authors. For all cases involving static loading, an exoskeleton would seem to be advantageous, but sometimes the advantage is quite small. If impact is considered, the advantage of exoskeletons becomes very much reduced, even on theoretical calculations; and it is likely that in life the advantage may be converted to a disadvantage, particularly in large active animals such as vertebrates.
    Additional Material: 6 Ill.
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 123 (1967), S. 43-61 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Silver stained Cordylophora were examined by light and electron microscopy, which provided a general picture of nerve cell forms and distribution for comparison with electron micrographs of osmium-fixed tissues from the same hydroid. Muscle, nerve and neurosensory components were studied in the nectophore of Nanomia (O. Siphonophora) and in the hydromedusae Sarsia and Euphysa by means of vital staining and optical and electron microscopy of epon sections; particular attention was given to relationships and interconnections between the cellular elements of the two marginal nerve rings. Mitochondrial size, numbers and types of vesicles and the occurrence of neurotubules and of parts of sensory cilia may provide useful ultrastructural clues for recognizing nerve elements, but serial sections are often needed to make identification conclusive.In Cordylophora and Nanomia, some neurites contain massed A vesicles (membrane-bounded dense granules) suggestive of neurosecretion (cf. reports on Hydra). However, a small type of A vesicle also occurs at synapses in Sarsia, indicating a probable role here in junctional transmission. Vesicles occur on both sides of some synapses (as previously reported for Cyanea) but on one side only in others, these being the first examples of polarized junctional ultrastructure in coelenterates.
    Additional Material: 9 Ill.
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 123 (1967) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 123 (1967), S. 231-249 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A correlated light and electron microscope study was made of lymphocyte-epithelial relations in the appendix of normal rabbits, ranging in age from one week to ten months. The lymphocyte migration into the epithelium was very slight at one week. The lymphocytes were increased considerably in number from two weeks to three months, grouping into unique nests in the epithelium. The basement membrane began to be penetrated by migrating cells at one week and bacame discontinuous in older animals. At one and two weeks, the epithelial cells contained glycogen, which disappeared at three weeks. Degenerating cells as well as bacilli were found in the epithelial cells and in the macrophages of the nodules. The varied appearance of bacilli in the macrophages indicates that they were being digested. The lymphocytes in the epithelium were larger, having less crowded cytoplasm as compared with those in the lymph nodules. Many lymphocytes were in deep folds of epithelial cells. There was evidence favoring an intracellular position for some lymphocytes in the epithelium.
    Additional Material: 1 Tab.
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  • 11
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: White Leghorn eggs were incubated to desired prevasular stages. Each embryo, upon its intact yolk and surrounded by albumen, was rolled from the shell into a sterile 50 ml beaker. In an uppermost position, the blastoderm was lightly stained with neutral red. Three types of localized cuts were made as indicated below, and the beaker-embryo unit placed in a sterile humidified chamber for further incubation. Results: (1) Unilateral cuts adjacent to the body and parallel with its axis blocked or suppressed formation of the vitelline artery on the cut side, even though healing occurred; (2) A specific site was found in the area pellucida opposite the sinus rhomboidalis which, when lightly cut perpendicular to the body axis, resulted in blockage or shifting of the final junction between aorta and vitelline artery as far cephalad as the thirteenth somite level. Formation of a dual final junction with the aorta also occurred. (3)Transverse cuts through the body axis and into the area pellucida bilaterally, frequently resulted in bilateral blockage or bilateral shifting. In still other cases, growth of a functional loop around the cut to connect the aortae in anterior and posterior segments with the vitelline artery were observed. Other unique circulatory patterns are described.Apparently, slight interference with the capillary plexus which precedes the vitelline artery causes anomalous development. Circulation is considered a major factor in arterial differentiation. Cutting probably alters the plexus and relation of its components to the onset of blood flow.
    Additional Material: 5 Ill.
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  • 12
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Branches of the coronary arteries of normal human hearts, supplying both atria and ventricles, were found by fine dissection and have been named rami atrioventriculares. They comprise atrial branches from ventricular arteries and ventricular branches from atrial arteries. Their incidence was 74% in the 50 adult individuals studied. The subjects had committed suicide with a poison which did not damage the coronary arteries. The atrioventricular branches constitute communications across the coronary sulcus, thus establishing a continuity between the atrial and the ventricular arterial supply. Therefore, there is not invariably a sharp demarcation of blood supply between atria and ventricles, as has been commonly taught. Neither atrial nor ventricular branches consist exclusively of ascending and descending branches of the coronary arteries, as has been assumed. Atrioventricular branches can play a role in collateral circulation and may, in individuals who are born with them, provide an explanation for some of the variability in signs and symptoms incidental to heart attacks.
    Additional Material: 4 Ill.
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  • 13
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The paper deals with the development of the salivary gland system in Melipona quadrifasciata anthidioides, which begins in the prepupal stage. The silk glands degenerate by autolysis at the end of the larval stage. Degeneration is characterized by cytoplasmic vacuolization and pycnosis of the nuclei of the secretory cells. The glandular secretory portion of degenerated silk glands separates from the excretory ducts. The salivary glands develop from the duct of the larval silk glands. The thoracic salivary glands develop from the ducts of the secretory tubules and the head salivary glands from the terminal excretory duct. The mandibular glands appear in the prepupa as invaginations of mandibular segments, and their differentiation to attain the adult configuration occurs during pupation. The hypopharyngeal glands have their origin from evaginations of the ventral anterior portion of the pharynx. A long tubule first appears with walls formed by more than one cellular layer. Then some cells separate from the lumen of the duct, staying attached to it by a cuticular channel in part intracellular. The initial duct constitutes the axial duct, in which the channel of the secretory cells opens. During the development of salivary and mandibular glands, they recapitulate primitive stages of the phylogeny of the bees. During the development of salivary glands system, mitosis accounts for only part of the growth. Most of the growth occurs by increase in size of cells rather than by cell division. In brown-eyed and pigmented pupae six days before emergence, the salivary gland system is completely developed, although not yet functioning.
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  • 14
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The caudal anatomy (caudal skeleton, musculature, vascularization, innervation, and urohypophysis) and swimming behavior of three clupeiform and three perciform fishes: Elops hawaiensis (Cupeiformes: Elopidae), Oncorhynchus nerka (Cupeiformes: Salmonidae), Chanos chanos (Clupeiformes: Chanidae), Kuhlia sandvicensis (Perciformes: Kuhlidae), Apogon menesemus (Perciformes: Apogonidae), and Gnathanodon speciousus (Perciformes: Carangidae), were studdied. The taxonomic significance of caudal structures was determined and evaluated by detailed examination of differences in caudal anatomy. An interpretation of functional significance of these differences was attempted by relating them to observed differences in swimming behavior. The swimming behavior was studied by the observation of swimming activities of fish while resting or cruising and while feeding in the aquarium, and by an analysis of each frame of an 8 mm movie film of swimming activities.There are certain consistent and basic differences between all three species of the order Clupeiformes and all three species of the order Perciformes in respect to caudal structures. Although certain caudal structures show overlapping in number and/or complexity of arrangement, they seem to indicate more complex structural organization in Clupeiformes than Perciformes. The differences confirm the conclusion of others that the order Clupeiformes is more “primitive” than the order Perciformes.With respect to caudal structures of the three clupeiform species studied, E. hawaiensis is the most “primitive” and, of the three perciform species studied, K. sandvicensis is the most “primitive.”Caudal structural variations from one species to another are related to the mode of adaptation to swimming as well as to the evolutionary status of the species.
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  • 15
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The forms of the tectorial membrane and its connections to the ciliary tufts of the hair cells have been studied in detail in 18 species of lizards and, less thoroughly, in three others. This group, which represents eight lizard families, exhibits three forms of tectorial membrane: a complete form that connects to all parts of the auditory papilla, an abbreviated form that makes this connection only in one limited region of the papilla, and a dendritic form in which the distal portion of the membrane subdivides into strands reaching all the hair cells.Sometimes the tectorial membrane connects directly with the tufts of the hair cells, but more often it makes this connection through intermediary structures. Seven types of such intermediary structures have been identified (if we include the sallet, which is not “intermediate” in a strict sense).Detailed descriptions are given of the various forms of tectorial membrane structures and their variations along the auditory papilla in 12 lizard species. The description for Iguana iguana is offered as representative of the iguanid pattern found in ten members of this family.Consideration is given to the functioning of the tectorial membrane, and also of the sallet, in the process of hair-cell stimulation.
    Additional Material: 15 Ill.
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  • 16
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: There were no lymphatic vessels and lymph nodes demonstrable in adult and larval Rana catesbeiana by a method that adequately demonstrated the same in mammals. Although the parenchymal arrangement in the lymphomyeloid organs is not exactly the same as in mammalian hemal nodes, nonetheless the vascular patterns of the lymph glands and jugular bodies are prima facie evidence that they function as blood-filtering organs among other probable functions. The vascular pattern of the lymph gland is that of a rete mirabile, particularly a venous portal system, inasmuch as the afferent and efferent vessels are venous in character and interposed between them is a labyrinth of sinusoids. This is not the case, though, in the adult organs. The vascular pattern of the jugular bodies is very much like the spleen, viz., artery-capillary-sinusoid-vein sequence. It is doubtful, however, if the propericardial and procoracoid bodies ever filter blood, because the smallest blood vessels in them are capillary in type Because of the absence of a well-defined capsule in some parts of the propericardial body, similarly to lymphoid follicles, especially in the mammalian gastrointestinal tract, it is probable that it filters tissue fluid. The last two organs are apparently mainly blood cell-forming organs. It is inferred from the vascular connections of the larval and the adult lymphomyeloid organs that they are not genetically related. This aspect was analyzed from earlier developmental data, but actual follow-up of the larval organs to the adult stage is still in progress.
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  • 17
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Histological serial sections of spleens from the adult raccoon (Procyon lotor) and woodchuck (Marmota monax) were processed for microscopic examination. Observations related to various aspects of the internal vascular pattern in the spleen of the raccoon and woodchuck demonstrated features that were characteristic of the respective animal. The spleen of the raccoon possess well-developed ellipsoid sheaths, whereas these same structures were not as prominent in the spleen of the woodchuck. The spleen of both mammals examined demonstrated the presence of an anastomosing series of venous sinuses within the red pulp tissue and may be classified as sinusal in nature.
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  • 18
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 121 (1967) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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  • 19
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 121 (1967), S. 55-70 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Light and electron microscopical studies allow a descriptive account to be given of he morphogenesis of the egg chamber of Drosophila melanogaster. The study demonstrates that the mitotic products of a single cystoblast generate a branching chain of 16 inter-connected cystocytes. Two specific cystocytes enter meiotic prophase, while the rest become nurse cells. The two pro-oocytes form synaptinemal complexes in their nuclei. However, one of the two cells later switches back into the nurse cell developmental pathway. The elongation of the synaptinemal complexes is described, and estimates are made of the time involved in their formation. These complexes continue to be synthesized long after the DNA replication which gives the oocyte its 4C DNA content. This finding implies that at least some genetic crossing over follows DNA replication. Evidence is presented that cells undergoing crossing over are most efficient in repairing radiation-induced chromosomal breaks. Suggestions are given as to the mechanisms by which (1) cell division is inhibited once 16 cystocytes are formed, (2) the future cleavage planes of cystocytes are programmed, (3) the pro-oocytes are differentiated from nurse cells, and (4) the oocyte is chosen from the twin pro-oocytes. The contrasting behaviors of the oocyte and nurse cell nucleoli are described. During oogenesis nucleolar synthesis of ribosomal RNAs is suppressed in the oocyte and concurrently stimulated in the nurse cells. It follows that the nurse nuclei are the major sources of the prodigious quantities of ribosomes found in the ooplasm of the mature oocyte.
    Additional Material: 12 Ill.
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  • 20
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The enigmatic lophophoral organs of phoronids are demonstrated to by accessory sex glands. In the hermaphroditic Phoronis vancouverensis, each mature adult has two pairs of such glands: female nidamental glands that facilitate the temporary brooding of the embryos and male accessory spermatophoral organs that function in spermatophore elaboration. Functional males of Phoronopsis harmeri have complex accessory spermatophoral organs while females of this non-brooding dioecious species lack accessory sex glands.In both species, coelomic spermatozoa are accumulated within the nephridia and passed en masse into the partially enclosed spermatophoral organs. There each sperm mass is molded into a characteristic shape and encased in one or more membranes before release as a spermatophore into the ambient water. The structure of the spermatophore is characteristic for each species and is correlated with the functional morphology of the distinctive spermatophoral organs.The existence of spermatophores, the non-primitive nature of the spermatozoa, and additional features of reproductive biology dictate that fertilization is internal in these species, but attempts to determine the means of sperm transfer proved futile. Reproductive potential and behaviour of male Phoronopsis, means of gamete segregation in Phoronis, and general pattern of reproductive biology for both phoronids were also studied.
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  • 21
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 121 (1967), S. 19-28 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In the column of hydra, tissues continually move away from a region located just underthe whorl of tentacles. Above this subtentacular region, tissues proceed into the hypostome and tentacles; below it tissues pass into the buds or continue down the stalk. These movements represent a steady state pattern of tissue renewal in which column growth is balanced by tissue loss at the body extremities. But the existence of a subtentacular zone in which tissue appears stationary does not necessarily indicate that growth is restrictedto this region, as is commonly stated.The body column of hydra can be viewed as an expanding cylinder whose elongation is balanced by tissue loss at the two ends. In such a body there must be one region from whichtissue appears to emanate, regardless of how growth is distributed along the cylinder. Only the rates at which tissues move will be characteristic of the underlying growthpattern. In Hydra littoralis, the measured rates of tissue movement down the gastric column are consistent with the distributions of mitotic figures, which indicate that growth is spread out along the column.
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  • 22
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 121 (1967), S. 71-80 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Profiles of fresh chick lenses of 5, 8, 11, 14, 17 and 20 days embryological age were photographed and from tracings of these profiles, volumes were calculated using a formula for volume of a solid of revolution. Accurate volumes were also obtained by assuming the lens to be two half oblate spheroids of different minor axis, or, better, two half-solids of profile (x/a)k + (y/b)k = 1. In addition, the k in this equation described well the curvature of the lens profiles and thus provided a quantitative measure of developing lens shape. Lens diameter, depth and shift of equatorial diameter upon lens axis as a function of age were also studied.
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  • 23
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Ductuli efferentes in four examined genera of family Didelphidae are organized into highly convoluted tubules, located within a conical body adjacent to the vascular plexus supplying the testis. They have yellowish-green color in the adult Didelphis virginiana and grey pink color in other genera. The ductuli efferentes in all examined animals are lined by very low columnar cells, covered by microvilli or booth cilia and microvilli.Histochemical analysis reveals several types of cytoplasmic granules in the genera examined. A single sperical body about 1.5 μ in diameter is found in epithelial cells of the four eyed opossum (genus Philander); this body stains positively for RNA and non-histone protein, and appears granular under the electron microscope, without a limiting membrane. Abundant cytoplasmic bodies in the Virginia opossum show strong reactions for SH groups; these granules may be responsible for the green color of the ductuli in this species. Ultrastructural studies show that the morphology of membrane limited granules in the ductuli of the examined genera is characteristic for each genus. Abundant pinocytotic vacuoles in the apices of these cells and a strongly positive alkaline phosphatase reaction suggest a marked absorptive activity of epithelial cells.
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  • 24
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 121 (1967), S. 179-207 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Detailed descriptions are presented of morphogenetic and histogenetic events occurring in the membranous and bony labyrinths, sensory areas, acoustic ganglia, and acoustic centers of the hindbrain of the chick embryo, stages 11 to 45. Major morphogenetic changes occur between stage 11 and stage 30. During this period primordial ganglionic neuroblasts are segregated from the otic epithelium and differentiate into the bipolar neuroblasts of the vestibular and cochlear ganglia, neuroblasts of the alar plate in the acoustic region of the rhombencephalon differentiate, migrate, and are organized into acoustic nuclei, and the otic cup closes to form a vesicle which undergoes complicated structural changes to become a labyrinth. Morphological events in neural structures are closely followed by structural changes in the labyrinth. Minor morphological changes continue to occur through stage 44. The histogenetic period, stage 26 to 38, is the same for all parts of the acoustic apparatus. Minor histogenetic events occur up to hatching. In this period, differentiation of ganglionic and central neurones precedes differentiation of sensory cells.
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  • 25
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 121 (1967) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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  • 26
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    Journal of Morphology 121 (1967), S. 223-239 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: With the help of PF and PAVB bulk-stained preparations and sections the neurosecretory system of Ranatra elongata has been described. Two medial, each of 9-10 cells, and two lateral, each of 3-4 cells, groups of neurosecretory cells have been observed in the protocerebrum. Only the A-cells have been found to be positive to PAVB histo- and cyto-chemical technique. Axons of the A-cells after traversing the proto- and deuto-cerebrum emerge from the tritocerebrum as the NCC I. The NCC I after bypassing the corpora cardiaca penetrate the aorta wall. There is no physical continuity between the corpora cardiaca and the NCC I and the two are separable. The NSM from the A-cells, transported by their nerve fibers, has been observed in the aorta wall. On the basis of large accumulation on NSM in the aorta wall the latter has been considered as the storage-and-release organ for the A-material. Corpora cardiaca are found to be devoid of A-material. Axons from the B-cells, after emergence from the tritocerebrum as the NCC II, have been observed to penetrate the corpora cardiaca. On the basis of ample amounts of B-material the glands have been considered as the storage-and-release organ for the B-material only.Observations are compared with results on related species and it is concluded that two independent organ complexes constitute the neurosecretory systemt of R. elongata. The A-cells, their pathways, the NCC I, and the aorta wall comprise the first; and the B-cells, their pathways, the NCC II, and the corpora cardiaca the second. The former is concerned with the elaboration, transportion, storage-and-release of the A-material and the latter with the B-material. Finally arguments are presented to include the aorta wall in the neurosecretory system.
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  • 27
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    Journal of Morphology 121 (1967), S. 311-321 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The anatomy of the ventral neck region of the scincid lizards Chalcides ocellatus and Scincus scincus is presented and is found to be similar to that of other lizards as described in the literature. The internal carotid artery arises by 3-5 roots from the dorsal side of the ascending limb of the carotid arch. During its first part, the internal carotid artery is completely divided into two nearly equal channels. The carotid sinus is more complicated in Chalcides than in Scincus. In lizards, it may be homologous to the carotid labyrinth of fishes and amphibians. Around the origin of the internal carotid artery are two kinds of epithelioid cells scattered in the adventitial connective tissue: a- large cells with rounded, faintly stained nuclei, and little, clear cytoplasm; b- cells with small darkly stained nuclei. Both kinds of cells appear to represent different levels of secretory activity. The number of the large cells increases with greater complexity of the carotid sinus. The cells also increase in size and number during summer (sexual period); this is especially true in younger animals. The epithelioid cells are considered to be homologous to the carotid body of higher vertebrates. The carotid sinus and epithelioid cells together form a closely interrelated system which may be intermediate between the carotid labyrinth of fishes and amphibians, and the carotid body of birds and mammals.
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  • 28
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The fine structure of the nerve cell types in the white planarian Procotyla fluviatilis were described. Ganglion cells comprise the major portion of the brain. These cells are irregular in shape with several cytoplasmic processes and contain ribosomes, a sparse endoplasmic reticulum, microtubules, lysosomes, and a Golgi apparatus with numerous small vesicles. Granule-containing cells are situated in the peripheral regions of the brain and along the nerve cords. These cells contain ribosomes, rough-surfaced endoplasmic reticulum and a Golgi apparatus with associated dense granules. The granules occupy most of the cytoplasm and are ∼ 750A in diameter with moderately dense contents, ∼ 750A with opaque contents, and ∼ 1000A with contents of medium density. These granules are similar to those in the nervous systems of higher animals that contain epinephrine, norepinephrine, and neurosecretory substance, respectively. Each cell contains predominantly one type of granule although there is some intermixing of granules and intermediate types between the three most abundant granules. Small clear vesicles, resembling cholinergic synaptic vesicles, and all types of dense granules occur in the neuropil and within nerve endings.
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  • 29
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A study of the ingestion of particulate matter from the pallial space located between the shell and the outer surface of the mantle of Isognomon alatus and Pinctada radiata was undertaken with the aid of the electron microscope. For this purpose colloidal thorium dioxide (thorotrast) was introduced into the pallial space for periods of 1-5 days after which time the mantle was excised and prepared for examination with the electron microscope. After 24 hours thorotrast micelles were observed in the pallial space, on the surface of the microvilli, in small pinocytotic vesicles between the bases of the microvilli, in vacuoles undergoing coalescence and finally in large dense bodies (lysosomes). Amoebocytes in the pallial space also participate in the removal of particulate matter in a manner similar to that described for the surface epithelium. During active ingestion the Golgi apparatus changes from a vesicular to a lamellar form. The method of ingestion observed in the surface epithelia and the amoebocytes is similar to the ingestion of protein and other particulate material reported for a variety of vertebrate tissues.
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  • 30
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 122 (1967), S. 231-247 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The proventriculus of White Leghorn chick embryos (stages 29-45) newly-hatched chicks, and adult chickens were frozen, sectioned in a cryostat and treated histochemically to identify localizations of alkaline and acid phosphatase, adenosine triphosphatase, 5-nucleotidase, nucleotide-diphosphatase, non-specific glycerophosphatase, glucose-6-phosphatase, non-specific esterase and succinic dehydrogenase. Ribonucleic acid, proteins and acid mucopolysaccharides were identified in tissues fixed in FAA.Acid phosphatase, nucleotide-diphosphatase, adenosine triphosphatase, succinic dehydrogenase, ribonucleic acid and proteins were present in the cells of the deep glands at all stages of development. Alkaline phosphatase and 5-nucleotidase were found only in mesenchymal derivatives of the proventriculus. After the chick begins swallowing and digesting albumen, enzymatic activity increased and non-specific esterase became very reactive.The surface epithelium is covered with a mucous coat. Ribonucleic acid, non-specific esterase, acid phosphatase and nucleotide-diphosphatase were localized in the basal portions of the epithelial cells. The functional significance of these different patterns is discussed.
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  • 31
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    Journal of Morphology 122 (1967), S. 265-305 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Basal tail constriction occurs in about two-thirds of the species of plethodontid salamanders. The constriction, which marks the site of tail autotomy, is a result of a reduction in length and diameter of the first caudal segment. Gross and microscopic anatomical studies reveal that many structural specializations are associated with basal constriction, and these are considered in detail. Areas of weakness in the skin at the posterior end of the first caudal segment, at the attachment of the musculature to the intermyotomal septum at the anterior end of the same segment, and between the last caudosacral and first caudal vertebrae precisely define the route of tail breakage. During autotomy the entire tail is shed, and a cylinder of skin one segment long closes over the wound at the end of the body.It is suggested that specializations described in this paper have evolved independently in three different groups of salamanders.Experiments and field observations reveal that, contrary to expectations, frequency of tail breakage is less in species with apparent provisions for tail autotomy than in less specialized species. The tail is a very important, highly functional organ in salamanders and it is suggested that selection has been for behavioral and structural adaptations for control of tail loss, rather than for tail loss per se.
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  • 32
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 123 (1967) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 33
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Esophagi of White Leghron chick embryos, six days to hatching, were fixed in 5% glutaraldehyde in a cacodylate-sucrose buffer, postfixed in 1% OsO4, dehydrated and embedded in Araldite. Tissues were sectioned with glass knives and viewed with a Philips EM 100C. The epithelium in early stages of development is characterized by small intercellular spaces, few cell processes and few desmosomes. In contrast the differentiated epithelium contains numerous cell processes, large intercellular spaces and numerous desmosomes. Mucin appeared in the mucous glands at 17 days.
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  • 34
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 121 (1967) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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  • 35
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Different types of sebaceous glands in guinea pigs were chosen to study their comparative responsiveness to steroid hormones. Glands selected were (1) Sebaceous glands associated with rudimentary hair in the supracaudal gland; (2) Free sebaceous glands of the nipple; (3) Sebaceous glands associated with the hair. The results showed distinct differences in sensitivity among these different sebaceous glands and according to the sex of the experimental animal. The most responsive of the glands in males was the supracaudal gland; in the female the most responsive glands were the sebaceous glands of the nipple. Sebaceous glands associated with normal hair were relatively insensitive to changes in hormonal level. In all cases testosterone propionate was more potent in stimulating any of the sebaceous glands than progesterone. After gonadectomy, various sebaceous glands showed unequal states of depletion due to the different rates of differentiation and disintegration of their cells into sebum.
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  • 36
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The lymphoid cell population of thymus in the rattlesnake and king snake is similar to that of mammals. Lymphocytes occupy the interstices of an epithelial cell framework. An abudance of tonofilaments and desmosomes occupy the cytoplasm of epithelial cells with light, homogeneous nuclei and prominent nucleoli. Other epithelial cells contain phagocytized material in a dense cytoplasm which surrounds an irregular nucleus with heavily clumped chromatin. Small, granular vesicles are found within some epithelial cells.Myoid cells occur in the medullary area. In mature forms, myofibrils are arranged in a concentric fashion around the nucleus and occupy much of the cytoplasmic volume. The presence of developmental stages of these cells suggests their differentiation within the thymus of the adult animal.
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  • 37
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 122 (1967) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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  • 38
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    Journal of Morphology 122 (1967), S. 19-33 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ovary in Callosobruchus analis consists of telotrophic ovarioles with the so called nurse cells confined to one chamber at the anterior end of the ovariole. There are three types of lipids in the ovary: (1) L1 bodies that are present in the early oocytes, in the posterior prefollicular tissue and in the follicular epithelium and contain unsaturated phospholipids; (2) L2 bodies that have a complete or incomplete sheath of phospholipids and a triglyceride core; (3) L3 bodies that are formed of highly saturated triglycerides. Lipids are absent from the trophic tissue. In a mature oocyte the L1 and L2 bodies are cortical in distribution while the L3 bodies are centrally located.The mitochondria contain lipoproteins with RNA. The yolk spheres are acid mucopolysaccharides and protein in nature. The precursors of the yolk spheres appear first in the cortical coplasm and are absent from the follicular epithelium or the trophic tissue. The nucleolus of the oocyte shows evidence of extrusions that are believed to pass into the ooplasm.There are no nutritive cords connecting the trophic tissue to the oocytes; nor is there any evidence of any histochemically demonstrable nutritive material being contributed to the oocyte by the trophic tissue. The circumstantial evidence points towards a contribution of the raw materials to the oocyte by the haemolymph either through or in between the follicular epithelium in some soluble form or as submicroscopic particles.
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  • 39
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Parenteral administration of methylcellulose causes massive splenomegaly and hemolytic anemia in rats. The red pulp of the spleen is markedly cellular due mainly to: (1) large numbers of voluminous free macrophages containing methylcellulose-induced vacuoles, (2) an increase in the number of plasma cells and (3) stasis of blood evidenced by a large number of erythrocytes and platelets in vessels, sinuses and cords. White pulp changes are usually less marked. Here the major change is the presence of macrophages containing methylcellulose-induced inclusions. The slow circulatory time in the spleen and the increase in macrophages may cause the hemolytic anemia observed in these animals.
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  • 40
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The squirrel monkey uterine cervix was studied macroscopically and microscopically in intact and ovariectomized monkeys. The effect in ovariectomized monkeys of estradiol dipropionate or progesterone of both given after estrogen priming was studied by PAS staining.The lower portion of the cervix was dilated to form a vestibule into which projected fibromuscular colliculi which arose from the isthmic end of the cervix. The stratified squamous epithelium of the vagina was continuous through the external os with a similar epithelium lining the vestibule and covering the external surfaces of the colliculi. The transitional zone between the stratified epithelium and columnar cells was variable. The colliculi were covered internally with mucosal folds of columnar epithelium continuous with those of the endocervical canal.Glycogen concentration in the smooth muscle did not fluctuate markedly, irrespective of the hormones used. Glycogen granules were more numerous in the stratified squamous epithelium. Malt-diastase-resistant material appeared to be more abundant in the columnar epithelium and glandular lumina when the monkeys received both hormones than when they received solely estrogen or progesterone.
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  • 41
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 122 (1967) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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  • 42
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    Journal of Morphology 122 (1967), S. 169-173 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Histological examination of the fibrous and cellular connective tissue components of the periodontal ligament in the Caiman and the Alligator reveals the presence of reticular fibrillae, collagenic, elastic, and oxytalan fibers, as well as fibrocytes, osteoblasts, cementoblasts and epithelial rests. The oxytalan fibers differentiated by the peracetic acid aldehyde-fuchsin method are most numerous in the coronal region, radiating from the primary cementum into the periodontal ligament a short distance. Oxytalan fibers in fewer numbers are found interspersed between the oblique and the horizontal principal fiber bundles. Inasmuch as the crocodilian teeth have continuous replacement and thus a relatively short functional life, the oxytalan fibers of the Caiman and the Alligator appear to be proportionally fewer in number than they are in the mammalian periodontal tissues. The presence of the oxytalan fibers and epithelial rests in the Order Crocodilia (Crocodilia) adds to the number of dental structures shared with the Class Mammalia (Mammalia) (mammals) such as a stellate reticulum, a primary and secondary cementum and a periodontal ligament. This furnishes additional histological evidence for evaluation of the phylogenetic position of this group.
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  • 43
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Histochemical methods, especially azo dye methods for detecting acid phosphomonoesterase activity were applied to normal, regenerating and denervated, amputated limbs from larval Amblystoma maculatum. Efforts were made to control inactivation of enzymic activity and diffusion of both enzyme and reaction product. “Base-line” values for enzymic activity were determined for normal limbs. Activity appeared most intense in macrophages, less intense in epidermis and cartilage matrix. Some activity was detected in Schwann cells, peri- and endoneurium and muscle fibers form normal limbs. Enzymic activity in regenerating limbs was strongest within macrophages which appeared in increased numbers especially in early stages. Wound tissue showed little increased activity. As the blastema formed, increased enzymic activity was detected in epidermis and within increased numbers of macrophages. Chondrocytes showed increased activity especially during cartilage matrix deposition. Amputated, denervated limbs showed large numbers of active macrophages beneath and within epidermis and along muscle. As regression commenced, areas of cartilage matrix breakdown showed increased enzymic activity but, in general, greatest activity was in macrophages. The various possible roles of acid phosphomonoesterase activity in the specific biological situations dealt with are considered in light of such observations.
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  • 44
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    Journal of Morphology 122 (1967), S. 249-263 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Adult newts, Triturus viridescens, were treated with from 1.0-10.0 μg/g body weight of actinomycin D one day before amputation of both forelimbs. Mean survival times ranged from over 50 days in newts treated with 1.0 μg/g to 13.2 days in animals given 10.0 μg/g body weight of actinomycin. Low doses little altered the course of regeneration, but animals treated with over 2.0 μg/g never formed blastemas. In another series, animals were given doses of 2.5 μg/g body weight of actinomycin D at intervals from 14 days before to 30 days after amputation. It was found that certain signs of toxicity (loss of equilibrium) are related to the time of administration of the drug whereas others (hemorrhage into the limb stumps) are restricted to a definite phase of the regenerative process. Early administration of actinomycin completely inhibits regeneration whereas later treatment results in a considerably lessened effect. The postamputational stages which are basically destructive in nature are not noticeably affected by actinomycin D, but the phases of dedifferentiation, blastema formation and redifferentiation are strongly inhibited.
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  • 45
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    Journal of Morphology 122 (1967), S. 345-365 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The major events associated with the morphogenesis of the amphibian alimentary tract are described and illustrated with a series of photomicrographs that present a continuous account of the differentiation process from its onset at stage 38 until the initiation of feeding at stage 46. Histological evidence is presented for the normal disappearance of the midgut region of the archenteron and the de novo formation of the intestine through the yolk mass. The mechanics of intestinal lumen formation are discussed in terms of the dynamic autonomous actions and interactions of the endoderm and the splanchnic mesoderm. The opening of the intestinal lumen as a consequence of cytolysis or cellular digestion is discounted. The relation of the present observations to the previously described polar endoderm cells is considered.
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  • 46
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    Journal of Morphology 123 (1967) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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  • 47
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The bullfrog, Rana catesbeiana, possesses lympho-myeloid and epithelial structures that are morphologically similar in some respects to lymph nodes of mammals. These organs are present during the entire life cycle of the frog, however, the structures that are present during larval stages do not appear to be morphological precursors of adult organs. According to certain terms used previously by other investigators, two major organs are present throughout the larval stages: the lymph gland and the ventral cavity body. In the adult, the jugular body, the epithelial body, the precoracoid and propericardial bodies are found in the ventral neck region in contrast to the lateral and ventral arrangement of the lymph gland and ventral cavity body in larvae. The function of these organs is not known but it is believed that they play a role in the production of certain blood cells, particularly lymphocytes, and they may be involved in some aspects of the differentiation and maintenance of the immune response capacity.
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  • 48
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    Journal of Morphology 123 (1967), S. 441-461 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: An electron microscopic study of the functional mesonephros in the 8-day chick embryo revealed the following features of the nephron:Proximal tubule cells. Nuclei are spherical and basally oriented. Mitochondri are round or elongate with clear-cut cristae. Intramitochondrial granules occur sporadically. The Golgi complex, lying adjacent to the nucleus in apical cytoplasm, consists of flattened lamellae and associated secretion droplets. The cytoplasm is filled with ribosomes which occasionally are spiral in arrangement. Characteristic microvilli project from the apical end of cells. Basal regions of the cells are bounded by a homogeneous basement membrane. Adjacent epithelial cells are separated at their base by wide intercellular spaces. Interdigitating processes between cells are common in this area. At their apices, cells are joined by junctional complexes.Distal tubule cells. Nuclei are round and centrally located. Microvilli are sparse and usually absent. When present, they are short and blunt. Cells are closely allied at their base and joined tightly at their apices. Interdigitating processes are not as prevalent as in proximal tubules. Infoldings of the plasma membrane are prominent and compartmentalize mitochondria.Glomerulus. Endothelial cells are elongate, bordering the capillary lumen, and their membranes contain definite slit-pores. Epithelial pedicels extend from the cell body, intergiditate with each other and rest on the capillary basement membrane. The latter consists of three layers resembling those in adults.The similarity in the fine structural characteristics between chick mesonephros and adult metanepros corroborates the holonephric theory of vertebrate kidney evolution.
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  • 49
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    Journal of Morphology 123 (1967), S. 559-567 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Hemolymph cells of Orconectes virilis were stained during the months of August to November by a variety of histological and histochemical techniques. Cells were classified as hyaline cells, small granulocytes, and large granulocytes. Presence of mitochondrial enzymes was indicated by tests for succinic dehydrogenase and cytochrome oxidase. Reaction to test for the hydrolytic enzyme, leucine acylnaphthylamidase was intense in the granules of the large granulocytes. The PAS reaction indicated a mucopolysaccharide at the cell membrane. Lipid was found in all three hemolymph cell types of Orconectes virilis at the time of this study.
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  • 50
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    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 13 (1967), S. 1196-1202 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Two-phase, gas-liquid concurrent flow in packed beds was investigated with the use of an air-water system and 2-, 4-, and 6-in. diameter columns packed with tabular alumina particles of 0.025 and 0.027 ft. diameters. Total pressure drop, column operating pressure, and liquid saturation were measured as functions of gas flow rate, fluid temperatures, and flow direction at several constant liquid flow rates for each column.Correlation of the frictional pressure loss was achieved in terms of a defined two-phase friction factor and a second correlating parameter which is a function of the liquid and gas Reynolds numbers. A viscosity correction factor was required to extend the friction factor correlation to include liquid viscosities widely divergent from that of water.The liquid saturation data for both upward and downward flow were correlated in terms of the ratio of mass flow rates of the respective phases.
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  • 51
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    AIChE Journal 13 (1967), S. 311-315 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A previous paper introduced the pair-type-probability (PTP) function for use in molecular corresponding states theory. The present paper develops the predictive equations of Scatchard and Hildebrand and the correlation equations of Wohl from particular pair and triplet weighting functions for clusters of two and three molecules in a liquid mixture. The cluster-weighting idea therefore unifies the major prediction and correlation schemes now in engineering use.
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  • 52
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    AIChE Journal 13 (1967), S. 303-311 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: There are four points of flexibility in present molecular formulations of the corresponding states idea. At these points the procedure followed or the numerical values can be tailored to achieve better agreement between predicted and experimental properties without violation of physical principles. These flexibilities are the exponent values used in the pair-potential function, the averaging procedure used to obtain an effective mixture pair-potential function, the combination rule for unlike-pair parameters, and the selection of a reference substance. The first two flexibilities are used in this paper to show that the conformal-parameter equations can correlate excess free energy and activity coefficient data of highly nonideal liquid mixtures. A pair-type-probability function is introduced in the averaging procedure used to obtain a mixture pair-potential function. Any macroscopic or molecular property may be used in this weighting function to improve mixture-property prediction.
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  • 53
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    AIChE Journal 13 (1967), S. 316-318 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The observation that large bubbles entrained in accelerating viscoelastic fluids may suddenly stop and remain stationary for long periods of time, although imbedded in a region of high fluid velocities, is noted and described. An analysis of this phenomenon, termed the Uebler effect, shows that it may be expected to occur with all particulate matter provided that the continuum field fluid is accelerating sufficiently rapidly to generate high stresses as a result of fluid stretching, and provided these stresses change sufficiently rapidly in the direction of the velocity vector in the flow field.
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  • 54
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    AIChE Journal 13 (1967), S. 319-326 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: For a number of polymerization models, we have developed equations that enable one to follow in time the moments of the polymer size distribution and the conversion. The exact and approximate solutions for the leading moments of the size distribution are presented for polymerization with initiation, propagation, and termination by combination. Approximate solutions for polymerizations with the additions of termination by disproportionation, chain transfer to monomer, and chain transfer to solvent show how these reactions decrease the average polymer size. From a simple model that exhibits autoacceleration a concomitant increase in the average polymer size also occurs.
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  • 55
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    AIChE Journal 13 (1967), S. 395-396 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
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  • 56
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    AIChE Journal 13 (1967), S. 438-442 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In a high-pressure process, feed streams are continually pressurized and product streams are continually depressurized. A flow work exchanger offers an efficient and economical scheme for simultaneously pressurizing a fluid stream and depressurizing a substantially equivalent volume of another fluid stream. Its applicability is however limited to fluids under condensed state. A flow work exchanger uses a displacement vessel to form a closed loop with a processing system. The displacement vessel is alternately filled by a low-pressure feed and a high-pressure product, both pressurized and depressurized, respectively, by substantially nonflow processes. The pressurized feed is pushed into the processing system by the high-pressure product stream and the depressurized product stream is pushed out of the displacement vessel by the low-pressure feed stream. The application of a flow work exchanger is illustrated by means of several high-pressure processes and the direct and indirect advantages obtainable are described.
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  • 57
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    AIChE Journal 13 (1967), S. 443-449 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Local and average holdup and drop size distribution as function of flow rates were measured for kerosene drops and water in a countercurrent, 15-cm. I.D., 160-cm. long, spray column. The range of flow rates was 5 to 40 liters/min. of kerosene and 0 to 50 liters/min. of water. At the same pairs of flow rates of the dispersed and the continuous phases in spray columns, three modes of drop packings can be obtained. These are termed, in order of increasing average holdup and increasing regularity of flow patterns, dispersed, restrained, and dense packings. For dispersed packing, at low flow rates of the two phases, the holdup and the drop size are constant along the column. At high flow rates the drop size increases from bottom to top of the column and the holdup increases from top to bottom of the column. The range of flow rates for the operation of a spray column is extended by the use of a conical entry section (Elgin design) at the bottom of the column, by the formation of an equilibrium region in the conical section.The average holdup increases with increased flow rates of both phases for dispersed and restrained packings, and with decreased flow rates of both phases for dense packing.The best definitions of flooding in a spray column are either the point of maximum average specific area of the drops, which corresponds to the onset of coalescence in the column, or the start of rejection of drops from the column proper.
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  • 58
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    AIChE Journal 13 (1967), S. 449-452 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An analytic solution of the Nernst-Planck equations is derived which applies to a selective resin when film diffusion controls. The selectivity has a marked effect on the rate of exchange for a wide range of diffusivities. The unit-selectivity solution of Schlögl and Helfferich is included as a special case of the more general solution.
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  • 59
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    AIChE Journal 13 (1967), S. 453-456 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Experimental results are presented which indicate that the application of a fixed intensity of ultrasonic waves to a water-tetrachloride solution containing dissolved air provides yields of chlorine varying from zero to maximum simply as a function of the liquid height in the capillary above the transducer. The difference in heights of the liquid between zero and maximum yields is found to be equal to one-quarter the wavelength of the ultrasonic wave in the liquid. A mathematical model to explain this phenomenon is presented.
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  • 60
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    AIChE Journal 13 (1967), S. 457-465 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Removal of methane from a helium stream by adsorption on Columbia SXC activated carbon was studied experimentally and theoretically. A mathematical model for the process was developed and the governing differential equations were solved numerically. The model incorporates heat and mass transfer resistances within and around the adsorption particle. Wall effects and moderate heat loss to the surroundings are also included. The required heat and mass transfer correlations were obtained from the literature. Simple expressions were developed to determine the relative resistances for heat and mass transfer within and around the adsorption particles.
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  • 61
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    AIChE Journal 13 (1967), S. 465-475 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Frequency response methods were used to compare dynamic models for gas mixing and first-order reaction in a fluidized-bed reactor and for the experimental determination of interphase transfer characteristics. Theoretical predictions of frequency response characteristics were derived for two models based on the two-phase theory of fluidization. Experimental frequency response for a 1-ft. high bed were correlated better by a model based on perfect mixing in the dense phase than by a model based on plug flow in the dense phase. Excellent correlation was also obtained by a simple empirical model.
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  • 62
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    AIChE Journal 13 (1967), S. 540-545 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Methods are presented for the determination of the transient values of the vaporization efficiencies from the knowledge of various combinations of the transient values of operating variables. For the case where the temperature and the composition of the liquid phase for each plate are known, a direct solution for the vaporization efficiencies is presented. Also, a method is presented for the determination of the mixing parameters of a generalized plate model on the basis of known transient values of certain operating variables.
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  • 63
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    AIChE Journal 13 (1967), S. 545-550 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Irreversible, first-order, simultaneous heterogeneous and homogeneous reactions in an isothermal tubular reactor under laminar flow conditions are studied. Accurate values of the eigenvalues, eigenfunctions, and radial concentration profiles are found for the dilute system. Criteria are given as to when the homogeneous reaction may be neglected with respect to the heterogeneous reaction and vice versa. It is found that for a certain range of the rate parameters well-known limiting solutions apply. Outside this range, the new solutions must be used.
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  • 64
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    AIChE Journal 13 (1967), S. 593-599 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Liquid and gas phase compositions for the system helium-methane have been measured at 15° intervals from 95° to 185°K. up to 200 atm. pressure. Data for these seven isotherms were taken in a gas phase recirculation apparatus with chromatographic analysis. In most regions the phase compositions obtained are thought to be within ± 3% of the mole fraction of the minor component. The maximum deviation from the enhancement factor curve at the lowest concentration levels was 16%. These data are in excellent agreement with most of the very recent data but are in poor agreement with the older data for this system.
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  • 65
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    AIChE Journal 13 (1967), S. 607-607 
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    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 66
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    AIChE Journal 13 (1967), S. 614-615 
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    Keywords: Chemistry ; Chemical Engineering
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  • 67
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    AIChE Journal 13 (1967), S. 626-626 
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    Keywords: Chemistry ; Chemical Engineering
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    AIChE Journal 13 (1967), S. 626-831 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 69
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    AIChE Journal 13 (1967), S. 627-627 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 70
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    AIChE Journal 13 (1967), S. 826-827 
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    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 71
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    AIChE Journal 13 (1967), S. 828-829 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 72
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  • 73
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    AIChE Journal 13 (1967), S. 829-830 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
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  • 74
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    AIChE Journal 13 (1967), S. 628-636 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A theoretical investigation has been made of the effect of a moving interface upon gas-liquid mass transfer, where the control of the mass transfer is entirely within the gas phase and where the control is distributed between the two phases. An analytical model is proposed for laminar interphase mass transfer in infinite media. Computer solutions have been obtained for gas-liquid mass transfer in confined phases. A cocurrent moving interface increases mass transfer confficients over what they would be for the same flow rate without interfacial motion.
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  • 75
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    AIChE Journal 13 (1967), S. 644-649 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Accompanied by a bried theoretical consideration, the results of an experimental study of the streaming potential fluctuations in turbulent pipe flows of distilled water are presented. The dependence of the streaming potential fluctuations on turbulent velocity fluctuations and other parameters as indicated by the theory is determined from the experimental data. Information on the characteristics of turbulent velocity fluctuations in the viscous sublayer near a pipe wall have been inferred from the data.
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  • 76
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    AIChE Journal 13 (1967), S. 637-644 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A horizontal, rectangular channel of high aspect ratio has been built for the study of interphase mass transfer in stratified, laminar gas-liquid flow. Cases were examined where the resistance to mass transfer is confined to the gas phase and where the control is distributed between phases. Measurements of the rate of evaporation of ethanol into oxygen and carbon dioxide confirmed that cocurrent interface motion enhances gas phase-controlled mass transfer coefficients substantially. On the other hand countercurrent motion of the interface decreases the coefficient. Agreement with basic convective diffusion theory was found for the evaporation of ethyl ether into helium and carbon dioxide from dilute solutions in ethanol, cases where the mass transfer control is distributed between the phases. Experiments with aqueous solutions were hampered by the accumulation of surfactants at the interface. A diaphragm cell technique was used to measure diffusivities of 0.87 × 10-5 sq.cm./sec. for ethyl ether at high dilution in ethanol and 0.96 × 10-5 sq.cm./sec. for ethyl ether at high dilution in water at 25°C.
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  • 77
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    AIChE Journal 13 (1967), S. 689-696 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Experiments on mass transfer for fully developed flow in a pipe show that the eddy diffusivity for mass close to the wall is described by the functionality \documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{\varepsilon} {\nu} = g({y^+}) $$\end{document}The best interpretation of presently available data in a pipe and in an annulus is given by the following, more explicit relation \documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{\varepsilon} {\nu} = 0.00032y^{+ 4} $$\end{document}The evidence for this latter relation is not as conclusive as one would like. Accurate measurements of concentration profiles close to a wall are needed.
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  • 78
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    AIChE Journal 13 (1967), S. 697-702 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Single bubbles of carbon dioxide were formed in a fixed position surrounded by a thin conical film of water flowing at average film Reynolds numbers in the range of 40 to 300. Measurements of interphase mass transfer at 32°C. and various bubble pressures agreed with predicted values only for the smallest bubbles. For larger bubbles, mixing perpendicular to the bubble interface was enhanced by waves, believed to be generated by the unstable interface. A comparison of interphase transfer coefficients between this investigation and previous work indicated that the bubbles at the lowest flow rates qualitatively fell in line with other measurements, but that the highest water flow rates gave distinctly higher coefficients.
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  • 79
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    AIChE Journal 13 (1967), S. 709-717 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A horizontal thermal diffusion column is described in which the inefficiencies caused by the forgotten effect and parasitic remixing are avoided. Experimental results obtained on the separation of water-ethyl alcohol mixtures are presented along with a phenomenological theory for the performance of the column.
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  • 80
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    AIChE Journal 13 (1967), S. 702-708 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Measurements of laminar dispersion in a capillary have been used to determine the molecular diffusion coefficients of hydrogen and helium dissolved in water over the temperature range of 10° to 55°C. Literature correlations did not predict realistic values of the diffusivities for the hydrogen - water and helium - water binaries. A statistical analysis of the experimental diffusion coefficients indicated that they could be related to the absolute temperature by a semiempirical correlation, which may be considered an extension of the well-known Wilke-Chang correlation. This relation was based on the absolute reaction rate model of liquids.
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  • 81
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    Notes: The P-V-T-x phase relations of helium - n-butane system were measured in the region of low helium content (up to 10.4 mole % helium). The system exhibits the gas-gas equilibrium originally predicted by Kamerlingh-Onnes and Keesom. The term gas-gas equilibrium is applied because the critical temperatures of the mixtures are higher than the critical temperature of either component. This behavior is quite unlike that observed in most binary systems, in which the critical temperature of the mixtures lie between those of the pure compounds. As a consequence of the shape of the critical locus curve, the system exhibits isothermal retrograde condensation of the second kind.
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  • 82
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    AIChE Journal 13 (1967), S. 745-750 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The speed range of the low-speed theory for cylinder withdrawal is extended by a correction for gravity and a modified use of the thin meniscus assumption. Experimental evidence indicates that this gravity corrected theory holds over a 3,000-fold range of speed, in terms of capillary number. This gravity corrected theory reduces, as special cases, to several other previously published theories as well as to the low-speed theory.
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  • 83
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    AIChE Journal 13 (1967), S. 759-763 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In this paper a conjecture of Aris is proved to be correct, that of all catalyst particles of fixed volume for isothermal first-order chemical reactions the spherical particle has the lowest effectiveness factor. The method of proof uses a process of symmetrization. Some conjectures are also made about other chemical reactions. The method of proof is also valid for two-dimensional domain (infinite cylinder).
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  • 84
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    AIChE Journal 13 (1967), S. 764-768 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Single seed crystals of potassium chloride were grown from aqueous solutions under conditions of constant temperature, supersturation, and impurity concentration. With emission spectrography as the method of analysis, the distribution of various metal ion impurities between the grown potassium chloride crystal and the solution was studied. The distribution coefficients of Pb++, defined as the ratio of the impurity concentration in the crystal to the concentration in solution, were found to be greater than unity at very low concentrations. The lead distribution coefficients varied between 2,700 for solutions containing 10-8 moles of lead/mole of potassium chloride to 28 (for solutions of 10-5 moles of lead/mole of potassium chloride).The results suggest a mechanism of nonequilibrium capture of the impurity. The magnitude of the distribution coefficient is shown to depend on the equilibrium distribution coefficient between the solution and surface of the crystal, the rate of growth of the crystal, and the rate of diffusion of the impurity through the crystal lattice. These results are believed to be of significance in the purification of materials by fractional crystallization. For instance, they indicate that in order to produce crystals of lead-free potassium chloride, the conventional techniques or recrystallization should be modified to include rejection of the first crystals grown.
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    AIChE Journal 13 (1967), S. 779-783 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Bubble frequencies and departure volumes in nucleate pool boiling have been obtained for a variety of liquids at pressures ranging from 50 to 760 mm. Hg. The bubble dynamic data conclusively show the volumetric vapor flow rate to be a strong function of the Jakob number in qualitative agreement with the heat transfer measurements of Nickelson and Preckshot. The data also indicate the volumetric vapor flow rate per cross section to be independent of the Jakob number, in agreement with existing equations.
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  • 86
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    AIChE Journal 13 (1967), S. 768-778 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Discrete control algorithms, suitable for programming in a direct digital control computer, are presented. For processes whose dynamics can be adequately modeled as first order with delay, digital compensation algorithms are derived to yield theoretically a response with finite settling time, when the system is step forced in either set point or load. The utility of the proposed designs is experimentally verified by application to a higher order physical process whose dynamics are not fully described by the model. The results demonstrate that sampling frequencies may be reduced considerably below presently accepted values while still maintaining transient response characteristics of the system comparable with those obtainable from conventional continuous control.
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  • 87
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    AIChE Journal 13 (1967), S. 915-925 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The chlorination of propane was studied in a tubular flow reactor, with outside illumination, at atmospheric pressure. At chlorine concentrations of less than 1.5 mole % (and inert nitrogen above 94%) a second-order (in chlorine) rate expression was indicated. At higher chlorine or propane concentrations propane affects the rate. Two rate equations, based upon different termination steps for the chain carriers, were found to fit the data. For the low concentration region the apparent activation energy for the overall reaction was 3.4 kcal./g.-mole. Most of the measurements were carried out with polychromatic light, but data taken with a narrow band of radiation, over the range 2,200 to 5,400Ā, showed an increase in rate with decreasing wave length. As a first step toward reactor design, differential reactor data were used to predict the conversion for laminar flow, integral reactor conditions. A reactor model which included the effects of residence time distribution and radial variation in light intensity gave good agreement with experimental data. A plug-flow model was less satisfactory.
    Additional Material: 10 Ill.
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  • 88
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    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 13 (1967), S. 931-935 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The general form of the equations describing a steady, two-dimensional flow of an incompressible liquid is reduced to a form containing only two parameters. The histories of stress and of deformation of a material element are written explicitly. A second-order, slow-flow approximation and a Maxwell type of constitutive equation are used to infer properties of the rheological behavior of viscoelastic liquids in such flows.
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  • 89
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    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 13 (1967), S. 936-947 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A new calculation method presented here for interpreting batch or tubular-flow reactor data (and also CSTR data) on three-component, three-reaction reversible systems is based upon the general analyses of Jost and of Wei and Prater. With advance knowledge of the pertinent equilibria, even a very few experimental points can be matched easily and rapidly to the given figures and equations. The simplification involved when one reaction disappears, with the divariant system thus becoming monovariant, is also described. Representative concentration-time curves are given for design purposes.
    Additional Material: 14 Ill.
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  • 90
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    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 13 (1967), S. 926-931 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In most control applications in the chemical process industries it is not realistic to attempt to define a unique mathematical statement of the control objective, for many criteria will satisfy the physical requirement of the rapid elimination of errors in the product stream as the result of an upset. The strong dependence of the structure of an optimal control system on the choice of objective then makes optimal control theory irrelevant in such situations, since the control engineer has no assurance that a complicated controller is a necessity of the process, rather than a consequence of an unfortunate choice of objective. In this paper an inverse problem is considered, in which an easily implementable feedback control system is first chosen and then is shown to be optimal for a physically meaningful objective in a large class of systems.
    Type of Medium: Electronic Resource
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  • 91
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    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 13 (1967), S. 948-954 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The results of an analytical and experimental study of compressible, axially symmetric, turbulent free jets exhausting into quiescent air are presented. A finite-difference technique was used to obtain a general solution which has eliminated the need for the simplifying assumptions required in previous investigations. The jet Mach number and jet temperature ratio have been found to be the only two initial jet properties which are necessary to characterize the dimensionless velocity and temperature variations in this type of jet. Modifications of dynamic eddy transfer coefficients given in the literature are used in the solution An experimental program was carried out to obtain data on free jet velocity and temperature variation at high initial jet temperatures and high subsonic Mach numbers where there has been a lack of experimental data. The numerical solutions of the time-averaged conservation equations have been shown to agree well with the experimental data of the present study and of previous investigations.
    Additional Material: 12 Ill.
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  • 92
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    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 13 (1967), S. 1018-1019 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 93
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    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 13 (1967), S. 1020-1024 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 94
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    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 13 (1967), S. 1025-1028 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 95
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    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 13 (1967), S. 1030-1031 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
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  • 96
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    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 13 (1967), S. 1072-1077 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Volumes translated in wakes of single drops of organic liquids rising through aqueous media have been measured. Organic drops studied comprised methyl isobutyl ketone, toluene, and toluene-carbon tetrachloride mixtures. Aqueous media comprised water and water-sugar solution. Distance of drop rise varied from 10 to 20 in. Drop size was varied such that Reynolds numbers of 40 to 800 were obtained. Volumes translated were nearly independent of distance for nonoscillating drops and decreased rapidly with distance for oscillating drops. Transition from nonoscillating to oscillating drops occurred at Reynolds number of 200. Measurements of drop velocities were also made.
    Additional Material: 6 Ill.
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  • 97
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    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 13 (1967), S. 1141-1154 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Under some conditions, continuous crystallization exhibits cyclic changes of the particle size even with constant input conditions. A linearized stability analysis has been performed to determine under what conditions this behavior can be expected. Numerical solutions of the actual nonlinear system equations were carried out to follow the cyclic behavior and to compute the cycle time and the amplitude of the fluctuations. The effect of seeding on the stability limits and product distribution was also evaluated.
    Additional Material: 11 Ill.
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  • 98
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    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 13 (1967), S. 1160-1166 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An experimental investigation of heat transfer rates in which were used three spray towers varying from 4 to 6 in. in diameter and 7 to 10 ft. in height, and distributor elements with hole sizes varying from 1/8 to 1/64 in. in diameter was carried out. The immiscible liquid system consisted of water and kerosene (normal boiling point range 395° to 490°F.). Volumetric heat transfer coefficients ranged from 100 to 3,600 B.t.u./(hr.)(cu. ft.)(°F.) and the overall film heat transfer coefficients ranged from 4 to 23 B.t.u./(hr.)(sq. ft.)(°F.). Height equivalent to a theoretical stage varied from 1 to 8 ft. Scale-up correlations relating these rate data to operating variables were developed.
    Additional Material: 9 Ill.
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  • 99
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    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 13 (1967), S. 1155-1159 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The pressure drop of water was measured when water flowed through a bed of stainless steel ball bearings packed in an ordered rhombohedral geometry. Experiments were carried out with eleven different packed beds, encompassing the entire range of the square-base array, in the same 10.85 by 10.85 by 30-in. rectangular test column in a forced circulation loop at modified Reynolds numbers up to 17,000. The test variables included water velocity, bed voidage, spacing between adjacent balls, ball diameter, and bed height. Curves of friction factor vs. Reynolds number are presented. An increase in the relative horizontal spacing between balls was found to have a more important effect than an increase in voidage in decreasing the pressure drop. A general correlation relating the mutual effects of bed voidage and ball spacing on pressure drop that would bring all the data points together, especially in the transition flow region, could not be found. As a result, the system appears to consist of two distinct parts separated at the minimum packing density. A correlation was found only for the first, but from a practical point of view more important, region. Data may be corrected for bed voidage, but only for small variations in ball spacing, by the ratios of (1 - ε)/ε3 at the two voidages. No entrance and exit effects could be measured beyond the first seven ball layers.
    Additional Material: 7 Ill.
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  • 100
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    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 13 (1967), S. 1171-1174 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A relationship for the diffusion coefficient of a dilute species in a mixture of two solvents is developed. The result, based on the linear additivity of the frictional activation energy which is valid for completely miscible, nonassociated systems, predicts the diffusion coefficient of the solute in terms of the limiting values of the diffusion coefficient of the solute in each of the solvents, the limiting values of the solvent pair diffusion coefficient, and two thermodynamic factors. The equation is confirmed for some recent experimental data.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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