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  • Artikel: DFG Deutsche Nationallizenzen  (1.290)
  • 1995-1999  (115)
  • 1955-1959  (1.175)
  • 1999  (115)
  • 1957  (626)
  • 1955  (549)
  • Organic Chemistry  (965)
  • Chemical Engineering  (210)
  • Rat  (115)
  • Nuclear reactions
Datenquelle
  • Artikel: DFG Deutsche Nationallizenzen  (1.290)
Materialart
Erscheinungszeitraum
  • 1995-1999  (115)
  • 1955-1959  (1.175)
Jahr
Schlagwörter
  • 101
    ISSN: 1432-2277
    Schlagwort(e): Key words Xenotransplantation ; 15-deoxyspergualin ; Guinea pig ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract This study aimed to investigate the effects of 15-deoxyspergualin (DSG), tacrolimus (FK 506) and cyclosporin A (CyA), alone or in combination, on delayed xenograft rejection (DXR). We used the guinea-pig-to-C6-deficient (C6–)-PVG-rat heart transplantation model, since in this strain combination, hyperacute rejection is avoided. In C6- control rats, the guinea pig xenografts survived for 39.2 ± 6.3 h (mean ± SD). Splenectomy alone resulted in a xenograft survival of 71.8 ± 7.8 h, but the addition of CyA or FK 506 did not further improve graft survival (73.6 ± 3.0 h and 72.0 ± 17.6 h, respectively). In contrast, DSG treatment increased graft survival to a mean of 99.8 ± 9.2 h. When CyA or FK 506 was combined with DSG, no additional effects were observed (105 ± 24.3 h and 95.1 ± 5.6 h, respectively). DSG alone or in combination with FK 506 or CyA resulted in a significant reduction in the serum IgM levels and reduced the deposits of IgM and IgG in rejected grafts. However, all xenografts were still heavily infiltrated by ED1 + macrophages, regardless of the treatment used. Thus, DSG treatment resulted in moderate prolongation of xenograft survival in C6– rats. The effect seems to be related to suppression of xenoreactive antibody production. To prolong xenograft survival further, strategies that inhibit macrophage infiltration seem required.
    Materialart: Digitale Medien
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  • 102
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 296 (1999), S. 235-246 
    ISSN: 1432-0878
    Schlagwort(e): Key words Transplantation ; Parkinson’s disease ; CNS fetal development ; CNS differentiation ; Neurotrophic factors ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract We have previously shown that a combination of the cytokines interleukin (IL)-1, IL-11, leukemia inhibitory factor (LIF), and glial cell line-derived neurotrophic factor (GDNF) can convert rat fetal (E14.5) mesencephalic progenitor cells into tyrosine hydroxylase (TH)-immunoreactive (ir) neurons in vitro. The experiments described here characterize the mesencephalic progenitor cells and their cytokine-induced conversion into dopamine (DA) neurons. For all experiments, we used bromodeoxyuridine (BrdU)-ir cultures of (E14.5) mesencephalic progenitor cells that had been expanded at least 21 days. We first demonstrated that IL-1 induced DA neuron conversion in mesencephalic progenitors, but not in striatal progenitors (P〈0.001). Thus, these cells should be classified as lineage-restricted progenitors, and not omnipotent stem cells. To further characterize cell populations in these cultures, we used monoclonal antibodies against Hu (an early marker for neurons), growth-associated protein (GAP)-43 (a marker for neuronal process extension), TH (a marker for DA neurons), and glial fibrillary acidic protein (GFAP, a marker for astrocytes). We assessed (E14.5) mesencephalic progenitor cell cultures (plated at 125,000 cells/cm2) incubated in the cytokine mixture (described above) or in complete media (CM, negative control). Following 7 days incubation, GFAP-positive cells formed a nearly confluent carpet in both types of cultures. However, numbers of Hu-ir and GAP-43-ir cells in the cytokine-incubated cultures far exceeded those in CM-incubated controls (P=0.0003, P=0.0001, respectively), while numbers of TH-ir cells were 58-fold greater in the cytokine-incubated cultures versus CM-incubated controls. The TH phenotype persisted for 7 days following withdrawal of the differentiation media. Numerous double-labeled cells that were BrdU-ir and also TH-ir, or Hu-ir and also TH-ir, were observed in the cytokine-incubated cultures. These data suggest that cytokines ”drive” the conversion of progenitor cells into DA neurons.
    Materialart: Digitale Medien
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  • 103
    ISSN: 1432-0878
    Schlagwort(e): Key words Subcommissural organ ; Isograft ; Xenograft ; Reissner’s fiber ; Cerebrospinal fluid ; Rat ; Bovine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract  The subcommissural organ (SCO) secretes glycoproteins into the cerebrospinal fluid (CSF) that aggregate and form Reissner’s fiber (RF). The factors involved in this aggregation are not known. One factor may be the hydrodynamics of the CSF when flowing through the aqueduct. This hypothesis was tested by isografting rat SCO and xenografting bovine SCO into the lateral ventricle of rats. Xenografts were either fresh bovine SCO or explants cultured for 30 days before transplantation. The grafts were investigated by electron microscopy and immunocytochemistry using antibodies against RF glycoproteins, serotonin and the glucose transporter I. Maximal time of transplantation was 43 days for isografts and 14 days for xenografts. The isografts were not reinnervated but were revascularized; they secreted into the ventricle RF glycoproteins that became progressively packed into pre-RF and RF structures identical to those formed by the SCO in situ. RF was confined to the host ventricle and at its distal end the constituent proteins disassembled. Xenografts were neither reinnervated nor revascularized and secreted into the host ventricle a material that never formed an RF. These findings indicate that the CSF factor responsible for the formation of RF is species specific, and that this process does not depend on the hydrodynamics of the CSF. The blood vessels revascularizing the isografted SCO acquired the characteristics of the vessels irrigating the SCO in situ, namely, a tight endothelium displaying glucose transporter I, and a perivascular space containing long-spacing collagen, thus indicating that basal release of glycoproteins may also occur in the grafted SCO.
    Materialart: Digitale Medien
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  • 104
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 295 (1999), S. 55-64 
    ISSN: 1432-0878
    Schlagwort(e): Key words Axonal transport ; Purkinje cell ; Organotypic culture ; Microinjection ; Antimitotic drugs ; Cytoskeleton ; Dendritic transport ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Axonal and dendritic transport in single Purkinje neurons of cerebellar slice cultures was quantified as single transport distances. Examination of the cells within a vital tissue was regarded as being an approach to the in situ condition. The Purkinje cells were organotypically integrated in the in vitro tissues and extended long axonal projections connecting synapses to the target neurons. The tracer horseradish peroxidase (HRP) was applied via microinjection to the somata of the Purkinje cells and the injected neurons were incubated thereafter for defined time-intervals. The tracer was transported anterogradely into the neuron processes. The measurements on both the axonal and the dendritic transport of microinjected HRP revealed continuous transportation with increasing times of postincubation. This transport was reduced by the use of microtubule-depolymerizing drugs. The axonal transport of the tracer was either retarded in colchicine-treated cells or continuously reduced for up to 50% in vinblastine-treated neurons. Thus, a correlation of axonal transport to the microtubules was demonstrated. The dendrites were filled with the tracer after 60 min of postincubation. Dendritic transport was reduced by the use of vinblastine, and not significantly by colchicine. The results strongly support the dependence of neuronal transport on microtubules as a component of the cytoskeleton.
    Materialart: Digitale Medien
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  • 105
    ISSN: 1432-0878
    Schlagwort(e): Key words Neurofilament ; Basket cell ; Pinceau ; Golgi apparatus ; Calcium binding protein ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract NCS-1 (neuronal calcium sensor) is a recently characterized member of a highly conserved neuron-specific family of calcium-binding proteins, which also includes frequenin and recoverin. The cellular and subcellular distributions of NCS-1 in the rat nervous system were investigated using light- and electron-microscopic immunohistochemistry. NCS-1 immunoreactivity was localized to neuronal cell bodies and axons throughout the brain and spinal cord but not to glial cells. The most intense labeling was observed in myelinated axons, the axonal ramifications of the basket cell in the cerebellar cortex, and large neurons in the brainstem and pons. These same structures were also characterized by heavy labeling for neurofilament protein, as determined by double-labeling experiments. Most axon terminals were unlabeled or only lightly labeled. The most remarkable subcellular staining occurred in the perikarya where intense labeling was associated with the membranes of the trans saccules of the Golgi apparatus. The widespread distribution of NCS-1 indicates that it may be active in a variety of calcium-dependent neuronal functions, whereas the specific subcellular localization to the Golgi apparatus and neurofilament-rich structures suggests a specialized role in calcium regulated protein trafficking and cytoskeletal interactions.
    Materialart: Digitale Medien
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  • 106
    ISSN: 1432-0878
    Schlagwort(e): Key words Glial cell line-derived neurotrophic factor ; GDNF ; Ret ; GDNFR-α ; Brain-derived neurotrophic factor ; BDNF ; NT-3 ; NT-4 ; trk receptors ; Thyroid tissue ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Levels of mRNA for neurotrophins (brain-derived neurotrophic factor, BDNF; neurotrophin 3, NT-3; neurotrophin 4, NT-4) and their receptors (trkA, trkB, trkC) and for glial cell line-derived neurotrophic factor (GDNF) and its receptors (ret, GDNFR-α) were measured in rat thyroid tissue by ribonuclease protection assays. In thyroid tissue the NT-3 mRNA level was threefold lower and the NT-4 mRNA level sixfold higher than those detected in adult rat hippocampus, while BDNF mRNA was undetectable. Very low levels of mRNA for truncated trkB and trkC receptors and no catalytic trkA, trkB or trkC were found. In conclusion NT-3 and NT-4, but not the corresponding functional receptors, are expressed in the thyroid tissue. Therefore, it is unlikely that these factors serve a direct local autocrine or paracrine function in thyroid cell types, and a target-derived mode of action on neurons innervating the thyroid tissue is suggested. An opposite result has been found for the neurotrophic factor GDNF: thyroid tissue showed a high level of transcripts for the GDNF receptor subunits (GDNFR-α and Ret), while GDNF mRNA was undetectable. The in situ hybridization analysis of GDNFR-α and ret mRNA revealed an interesting difference in the cell distribution of these transcripts: ret mRNA is selectively expressed in a subpopulation of cells scattered in the follicular epithelium and in the interfollicular spaces, while GDNFR-α expression is more homogeneous and widespread, including the more abundant cell type of the thyroid gland: the follicular cell. Double-labeling in situ hybridization/immunocytochemistry experiments, with a specific marker (calcitonin), showed that parafollicular cells express ret but not GDNFR-α. This differential distribution of the GDNF receptor components (GDNFR-α and ret) may reflect a peculiar biological role in intercellular communication in the thyroid gland.
    Materialart: Digitale Medien
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  • 107
    ISSN: 1432-0878
    Schlagwort(e): Key words Water channel protein ; Aquaporin ; AQP5 ; Rat ; Salivary glands ; Immunolocalization ; Secretory stimulation ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Aquaporin-5 (AQP5) is a water channel protein and is considered to play an important role in water movement across the plasma membrane. We raised anti-AQP5 antibody and examined the localization of AQP5 protein in rat salivary and lacrimal glands by immunofluorescence microscopy. AQP5 was found in secretory acinar cells of submandibular, parotid, and sublingual glands, where it was restricted to apical membranes including intercellular secretory canaliculi. In the submandibular gland, abundant AQP5 was also found additionally at the apical membrane of intercalated duct cells. Upon stimulation by isoproterenol, apical staining for AQP5 in parotid acinar cells tended to appear as clusters of dots. These results suggest that AQP5 is one of the candidate molecules responsible for the water movement in the salivary glands.
    Materialart: Digitale Medien
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  • 108
    Digitale Medien
    Digitale Medien
    Springer
    Age 22 (1999), S. 19-25 
    ISSN: 1574-4647
    Schlagwort(e): Norepinephrine ; Aging ; Free Radicals ; Antioxidants ; Cerebellum ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The present review provides an overview of age-related changes in cerebellar β-adrenergic function, associated motor learning, causal agents and possible treatments. Norepinephrine acts as a neuromodulator of Purkinje cell activity. With aging, however, the ability of norepinephrine to modulate Purkinje cell activity and specifically GABAergic inhibition of Purkinje cell activity is decreased. This age-associated deficit in cerebellar noradrenergic function correlates with deficits in acquisition of a motor learning task. Aged rats are delayed in acquiring a motor learning task that requires rats to adjust footfalls in order to cross a runway. The degree of deficit in cerebellar β-adrenergic activity correlated positively with the degree of impairment in task acquisition. One possible causal agent for the β-adrenergic deficit is free radical damage. Hyperoxia, which may generate free radical damage, induces cerebellar β-adrenergic deficits in young rats but diet restriction and treatment with antioxidants can delay or reverse age-related deficits in cerebellar β-adrenergic function in old rats.
    Materialart: Digitale Medien
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  • 109
    Digitale Medien
    Digitale Medien
    Springer
    European journal of applied physiology 80 (1999), S. 344-352 
    ISSN: 1439-6327
    Schlagwort(e): Key words Endurance running ; Bone density ; Deoxypyridinoline ; Osteocalcin ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract This experiment was performed to study the effects on femoral bone of endurance training performed during the 3 months before orchidectomy in rats which were then killed 90 days later. A total of 70 male Wistar rats were used at 8 weeks old. One day 0 of the experiment, 10 rats were killed by cervical dislocation and used as first controls. Among the 60 others, 30 were selected for treadmill running (60% maximal oxygen uptake, 1 h · day−1, 6 days · week−1 for 90 days). The 30 other rats remained at rest. On day 90, 10 exercised (IE) and resting (IR) rats were killed and used as intermediary controls. Among the 20 other animals of each group, 10 were surgically castrated (CXE, CXR) or 10 sham-operated (SHE, SHR) and killed on day 180. On day 90 femoral failure load (three-point bending test) was greater in IE than in IR. Simultaneously, the deoxypyridinolinuria was lower in IE than in IR. On day 180, femoral bones were thinner in CXR than in CXE. The lowest values for trabecular bone are in the distal femoral metaphysis were measured in CXE and CXR rats, but the value measured in CXE was no different from that measured in SHR. Simultaneously total femoral bone density was lower in CXR than in SHE, while no difference concerning femoral metaphyseal density was observed between CXE and SHR. These results confirmed that endurance running increased femoral bone growth and modelling and femoral trabecular area, and thereby peak bone mass, in 8-month-old male rats. In resting animals, castrated after the training period, androgen deficiency decreased femoral density, mineral content and trabecular area. This decrease was not observed in castrated but previously exercised rats. Thus, by increasing peak bone mass, it was considered that endurance training may have a preventive effect against orchidectomy-induced bone loss.
    Materialart: Digitale Medien
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  • 110
    ISSN: 1439-6327
    Schlagwort(e): Key words Bone ; Deoxypyridinoline ; Osteocalcin ; Rat ; Treadmill running
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The present study was designed to provide data on the effects on femoral bone of endurance training starting only 3 months after orchidectomy in rats. A total of 70 Wistar male rats were used at 8 weeks of age. On day 0 of the experiment, 10 rats were killed by cervical dislocation to be used as first controls. Among the 60 other animals, half was surgically castrated (CX) or sham operated (SH). On day 90, 10 CX and 10 SH were killed and used as intermediary controls (ICX and ISH). Among the other 20 CX and 20 SH, 10 within each group (CXE, SHE) were selected for treadmill running (60% maximal oxygen uptake, 1 h · day−1, 5 days · week−1 for 12 weeks). The 20 other rats were used as sedentary controls (CXR, SHR) and killed (as runners) on day 180. On day 90 femoral bone density (BMD) and mineral content (BMC) were lower in ICX than in ISH. On day 180 total femoral BMD was lower in CXR than in CXE. Simultaneously metaphyseal femoral BMD was lower in CXR than in CXE, SHR or SHE. Furthermore, at that time, no significant difference concerning BMD and BMC was observed between SHR and CXE. This would indicate that treadmill running starting only 3 months after orchidectomy is able to restore BMD and BMC to control values, mainly by inhibiting bone resorption (as shown by decreased urinary deoxypyridinoline excretion in CXE) without decreasing osteoblastic activity (evaluated by plasma osteocalcin concentration).
    Materialart: Digitale Medien
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  • 111
    ISSN: 1573-9104
    Schlagwort(e): Bioavailability ; Magnesium ; Hijiki ; Sodium alginate ; Rat ; Wakame
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The bioavailability of magnesium from Wakame and Hijiki, and the effects of alginic acid on absorption of dietary magnesium were examined in five groups of rats fed either control, Wakame, Hijiki, AW (containing the same amount of alginate as in the Wakame) and AH (containing the same amount of alginate as in the Hijiki) diets, and animals fed a low magnesium diet (LMg) (twentieth amount of magnesium in the original mineral mixtures as the control). Food intake and body weight gain were decreased by adding sodium alginate to the diets. A large amount of calcium accumulated only in the kidneys of the rats fed the LMg diet. Serum magnesium concentration decreased only in the LMg group. The magnesium content in the defatted left femurs did not differ between the control and Wakame fed animals and also among the animals eating Wakame, Hijiki and AW diets. The breaking force of the right femurs did not differ among all the groups except the LMg group. The ratio of apparent magnesium absorption (%) of the control, LMg, Wakame, Hijiki, AW and AH groups was 82.2, 72.7, 66.9, 50.8, 69.3 and 54.2 in the first experimental period, and was 75.3, 52.1, 57.7, 46.9, 62.6 and 60.5 in the second experimental period, respectively. It was clear that the bioavailability of magnesium in the Wakame fed rats was higher than in those eating the Hijiki. Large amounts of sodium alginate lowered magnesium absorption from the diet.
    Materialart: Digitale Medien
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  • 112
    Digitale Medien
    Digitale Medien
    Springer
    Langenbeck's archives of surgery 384 (1999), S. 461-466 
    ISSN: 1435-2451
    Schlagwort(e): Key words Liver transplantation ; Bile salt ; Tauroursodeoxycholate ; Rat ; Reperfusion injury
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Introduction: Tauroursodeoxycholate (TUDC) is used routinely in the treatment of cholestatic liver disease. The present study was designed to determine whether it would mitigate ischemia/reperfusion injury in an in vivo pig liver-transplantation model. Methods: Transplantation was performed in 12 animals after a preservation time of 8 h. In the control group (n=6), 0.9% saline was infused into the donor. In the experimental group (n=6), TUDC was given intravenously at a rate of 2 µmol/kg body weight per minute. In the recipient, infusion was started at the time of reperfusion; saline was infused for 400 min in the control group, TUDC for the same duration at a rate of 0.2 µmol/kg body weight per minute in the experimental group. Blood was drawn for determination of liver enzymes. Bile samples were collected and bile flow (BF) and bile salt secretion rate (BSSR) were determined. Results: One-week survival was 92% and not different among groups. Liver enzymes were lower in the TUDC group than the saline group. Prior to TUDC infusion in the donor animals, there were no differences in BF and BSSR. After infusion of TUDC, BF and BSSR were highly significantly different than the control group. Discussion: Infusion of TUDC in pig livers protects against ischemia/reperfusion injury in vivo. This might be due to the membrane-stabilizing effect of TUDC. Preconditioning of liver grafts with TUDC could potentially lead to improved liver function post-transplantation.
    Materialart: Digitale Medien
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  • 113
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 256 (1999), S. 442-444 
    ISSN: 1434-4726
    Schlagwort(e): Key words Wheat germ agglutinin-conjugated ; horseradish peroxidase ; Neural regeneration ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Regeneration of the mammalian central vestibular system was examined in rat. The lateral vestibulospinal tract (LVST) of infant rat was transected unilaterally at the level of C1–3. After a postoperative interval of several weeks, the LVST was examined by injecting an anterograde tracer (wheat germ agglutinin-conjugated horseradish peroxidase) into the lateral vestibular nucleus (LVN) and a retrograde tracer (Fast Blue) into the lumbar enlargement. More than half of the rats showed successful regeneration, indicating definite plasticity in the mammalian central vestibular system.
    Materialart: Digitale Medien
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  • 114
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 256 (1999), S. S38 
    ISSN: 1434-4726
    Schlagwort(e): Key words Taste buds ; Cytochalasin D ; Rhodamine-phalloidin ; Confocal laser microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Effects of cytochalasin D on actin filaments in cells encircling taste pores were examined to clarify the functional role of actin filaments in the maintenance of taste pores in rat fungiform papillae, using a confocal laser microscope and a scanning electron microscope. Fluorescence in the taste pore cells was detected as a ring shape produced by actin staining with rhodamine-phalloidin. Treatment of fungiform papillae with cytochalasin D diminished the positive reactions in the taste pore cells and increased the inner diameter of the ring reactions. However, deformation of the taste pores in fungiform papillae was not detected under a scanning electron microscope after treatment with cytochalasin D. These findings suggest that the organization of actin filaments encircling the taste pores contributes to regulation of the taste pore’s size in rat fungiform papillae.
    Materialart: Digitale Medien
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  • 115
    ISSN: 1573-0603
    Schlagwort(e): Dichloromethylene diphosphate ; Hepatic stellate cell isolation ; Liposome ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Hepatic perisinusoidal cell population consists of hepatic stellate cells, Kupffer cells, endothelial cells, and Pit cells. These cells are isolated by enzymic digestion and purified by density gradient centrifugation. With isolation of stellate cells, conventional method is unable to eliminate the contamination of Kupffer cells because the densities of these two cells are similar. We report here an improved method for isolation of highly purified hepatic stellate cells, using dichloromethylene diphosphate (CL2MDP), which has selective cytotoxicity of Kupffer cells. Three days after the single intravenous administration of liposome-encapsulated CL2MDP, the Kupffer cells disappeared almost completely from the liver. Following Percoll density gradient centrifugation, the purity of the hepatic stellate cells exceeded 98% without any contamination of the Kupffer cells. Kupffer cells are reported to affect the physiological functions of stellate cells. The availability of highly purified stellate cells will facilitate the investigation of their functions in primary culture.
    Materialart: Digitale Medien
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  • 116
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 92-100 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: This paper presents the first theoretical analyses combined with an experimental study of the variables controlling heat transfer rates to non-Newtonian fluids in the streamline-flow region. The theoretical analyses, for the limiting types of non-Newtonian materials, were related to the intermediate case of Newtonian behavior to form a coherent theory applicable to Newtonian and non-Newtonian fluids alike.The experimental data covered Graetz numbers between 100 and 2,000 and were correlated with a mean deviation of 13.5%. The flow-behavior indexes of the three non-Newtonian fluids used varied form 0.18 to 0.70.Some preliminary non-Newtonian results are presented on the problems of nonisothermal fluid-flow pressure losses and heat transfer outside the laminar-flow region. Further theoretical work is recommended in both these areas. Additional experimental data would be of value in all of the problems discussed.
    Zusätzliches Material: 19 Ill.
    Materialart: Digitale Medien
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  • 117
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 143 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
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  • 118
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 144 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
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  • 119
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 9M 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
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  • 120
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 145-145 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
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  • 121
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 157-161 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: To test the applicability, over a wide range of temperatures, pressures, and gas physical properties, of the mass transfer correlation presented earlier, 0.5-in. naphthalene Berl saddles were vaporized into air, carbon dioxide, and Freon-12 in a 4.0-in. column. Temperatures from 15° to 73°C. and pressures from 0.26 to 1 atm. were covered.The correlation was found to represent all the experimental data when the surface temperature of the naphthalene was used to evaluate the correct driving force.This correlation, when combined with effective interfacial areas presented previously, makes it possible to estimate the volumetric mass transfer coefficeint, kGa, for any gas-liquid-solute system.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
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  • 122
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 172-175 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The general problem of heat transfer to fluids in laminar flow in tubes is discussed, a new procedure for the measurement of local laminar-flow heat transfer coefficients is described, and an empirical equation is presented for the correlation of data for local heat transfer rates to liquids flowing upward in laminar flow in vertical tubes under conditions of constant heat flux at the tube wall.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 123
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 183-186 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Ion exclusion is an operation in which an ion exchange resin is used to separate an electrolyte from a nonelectrolyte in a polar solvent. An ion exchange resin tends to absorb a nonelectrolyte and to exclude an electrolyte. This is described quantitatively by the equilibrium distribution of the electrolyte, the nonelectrolyte, and the solvent between the resin phase and the liquid phase surrounding the resin.As no ternary distribution data applicable to ion exclusion are available, and only a few binary data have been published, a principal purpose of this investigation was to determine the distribution data for a typical system: glycerol-sodium chloride-water-Dowex-50.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 124
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 198-207 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A solution to the Stefan-Maxwell diffusion equations for equimolal countercurrent diffusion in a three-component gas mixture is obtained which is similar in form to Gilliland's equation for diffusion of two gases through a third inert gas. The important features of both types of diffusion are investigated and the conditions under which the following phenomena occur are determined: (1) diffusion barrier (the rate of diffusion of a component is zero even though its concentration gradient is not zero); (2) osmotic diffusion (the rate of diffusion of a component is not zero even though its concentration gradient is zero); (3) reverse diffusion (a component diffuses against the gradient of its concentration).A generalized driving force which describes these phenomena is introduced, and approximate equations are developed which give the individual rates of diffusion directly.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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  • 125
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 126
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 280-282 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: It has been shown both theoretically and experimentally that the radial Peclet number in a packed bed approaches about 11. If it is assumed that the interstitial volume of the bed forms mixing cells, then a comparison of the solutions obtained from the mixing and turbulent diffusive mechanisms shows that the axial Peclet number for agreement of the two must be about 2, as a limiting case for high Reynolds numbers. This is substantiated by experiment.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 127
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 8J 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 128
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 289-293 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Approximations are suggested to extend the usefulness of operational calculus in solving boundary-value problems of interest to the chemical engineer. General approximations are outlined and specific ones illustrated. The use of computing machines with operational calculus is also considered.
    Materialart: Digitale Medien
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  • 129
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 293-296 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Data are presented in support of an expression describing the relation between the sedimenting velocity or the fluidizing velocity and the fraction voids. This expression which contains no empirical constants may be obtained by considering a particle in a fluid having the average properties of the suspension. Stokes's law is used to calculate the force on the particle, and an equation derived by Vand is used to describe the viscosity of the suspension. The equation based on this model is valid for particle Reynolds numbers less than 0.07. The model may be used as an approximation of bed behavior at higher Reynolds numbers by application of a correction to Stokes's law.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 130
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 7S 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 131
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957) 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 132
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 433-438 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: This paper proposes a theory of filter-cake washing on continous filtration equipment based upon the assumption that mixing of the strong liquor and wash fluid is controlling. The theory can be conventiently applied to experimental filtration leaf tests for determining wash efficiency and is easily extrapolated to full-scale results with the normally experienced uneven cake thickness and wash-fluid distribution taken into account.To obtain the necessary wash-fluid volume for proper soluble removal, a correlation method of wash time as a function of wash ratio with parameters of cake-formation time has been derived from commonly accepted filtration theory. Experimental and plant data indicate a close agreement with the theory, and the method can be employed to predict filtration rate as a function of wash ratio. A typical illustration has been given to determine filtration requirements for recovering soluble uranium after leaching of the ore by continuous filtration. Washing rate was proved to be conrolling, and this design based only on cake-formation rate would yield insufficient wash ratios and excessive soluble uranium loss. Final filter and flow-sheet design must be based on uranium recovery which can be predicted by the proposed methods.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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  • 133
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957) 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 134
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 1-1 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 135
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 283-286 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Mass transfer coefficients have been determined for the dissolution of Na2S2O3·5H2O crystals in water under conditions of turbulent agitation in a mixing vessel. The dissolution was carried out in a steady-flow process in which the area of selt crystals and the concentration of the solution in the mixing vessel were constant during each run. A comparison is made with previously unpublished results for batch runs in a similar system, and a method is developed for calculating the surface area of salt particles suspended in the mixing vessel under steady-flow conditions.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 136
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 297-297 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 137
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 313-317 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A simple expression for estimating the turbulent forced-convection heat transfer performance of liquid metals flowing through noncircular ducts is presented. This equation requires the knowledge of the slug Nusselt number evaluated for the specific geometry and for the pertinent boundary conditions. Such Nusselt values are presented herein for a number of technically important geometries. One check on the heat transfer prediction given by Equation (4) is in the case of an annular duct with constant heat flow through the outer wall with the inner wall insulated, for which experimental data exist. The prediction agrees within 20% with the experimental data.Several possible boundary conditions that may exist in noncircular cross sections are throughly discussed, and it is hoped that as a result this paper may serve to clarify some of the confusion existing in the literature.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
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  • 138
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 329-330 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: With stationary isotropic turbulence postulated, the rate of decrease in concentration fluctuations of a scalar contaminant is estimated in terms of the turbulence scale and the power input to the system.
    Materialart: Digitale Medien
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  • 139
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 336-342 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Plate efficiencies measured on 18-in.-diam. sieve plates are reported for the acetic acid-water system and for the methyl isobutyl ketone-water system at atmospheric pressure. In the former system the major resistance to mass transfer is in the gas phase; liquid-phase resistance to mass transfer is controlling in the latter. Efficiencies are also reported for the aniline-nitrobenzene system (gas-phase resistance controlling) at 5 mm. Hg absolute on 6-in.-diam. sieve plates. Pure gas- and liquid-phase efficiencies for both plate designs were determined by the adiabatic humidification of air and the desorption of oxygen from water into air. Predicted values of plate efficiency for each of the binary systems studied were computed from the pure phase efficiencies according to the procedure outlined by Gerster et al. A comparison between measured and predicted efficiencies is presented as a guide for future research in this field.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
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  • 140
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 348-352 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The behavior of the film coefficient of heat transfer for the condensation of organic vapor mixtures was investigated experimentally to establish a satisfactory basis for applying the Nusselt equation to binary systems. Five ideal and nonideal pairs, all of which gave miscible condensates, were studied; the work was carried out under conditions of almost total condensation on a horizontal condensing surface designed to comply as rigidly as possible with the conditions for which Nusselt's equation is valid.The same behavior was observed for all systems and all concentrations studied: the experimental coefficients fell between those for the pure components and followed the behavior pattern for pure components when the temperature difference was taken as that between the bubble point of the condensate and the surface temperature, rather than between the dew point or the measured vapor temperature and the surface temperature, Correlation of the film coefficient showed it to vary approximately linearly with composition if the coefficients were compared at a constant value of the temperature difference, defined as above. This permits determination of the coefficient for a mixture by interpolation between the coefficients for the pure components, which are easily obtained, in preference to making the calculations with the properties of the mixture obtained by laborious and uncertain weighting of the corresponding properties of the pure components.When results are interpreted in the light of the theories of Colburn and Drew, the presence of a vapor-phase resistance to heat and mass transfer, as postulated by them, is indicated.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
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  • 141
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 366-372 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Kinetic studies were made in a differential flow reactor of the hydogenation of α-methyl-styrene with the liquid trickling over a bed of catalyst pellets countercurrent to a stream of hydrogen. The catalysts consisted of palladium, platinum, rhodium, ruthenium, and nickel supported on the external surfaces of aluminal pellets.With palladium at pressures above 3 atm. the apparent rate-controlling step was a surface reaction between dissociated hydrogen and α-methylstyrene both adsorbed on different type of active sites. Below 3 atm. pressure the reactants competed for similar active sites. With platinum the apparent rate-controlling step was a surface reaction between dissociated hydrogen and α-methylstyrene on similar active sites. Rhodium and nickel catalyzed the polymerization α-methylstyrene together with slow hydrogenation. Ruthenium had negligible activity for catalyzing the hydrogenation under the moderate conditions used in this work.In all cases mass transfer resistances were negligible.
    Zusätzliches Material: 13 Ill.
    Materialart: Digitale Medien
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  • 142
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 386-390 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The bulk chemical properties of an impregnated chromia-alumina catalyst with respect to several gases, CO, CO2, C3H6, were determined as a function of the degree of oxidation of the surface of the catalyst. The importance of the results lies in the demonstration that a simple method described herein can be used to obtain significant data on catalytic surfaces. Briefly, the prior adsorption of oxygen by the catalyst tended to promote the adsorption of carbon monoxide and to prohibit the adsorption of carbon dioxide. Far more carbon monoxide was adsorbed by the highly oxidized surface than could be accounted for on the basis of adsorbed carbon dioxide. The quantity of propylene adsorbed also increased with an increase in the oxidation of the surface. The results are explained on the basis of two types of adsorbed oxygen atoms.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
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  • 143
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 411-417 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: In the hydrogenation of α-methylstyrene by means of a suspended palladium-alumina catalyst in a stirred reactor the mass transfer of hydrogen through the liquid is the rate-controlling step and the resistance to chemical reaction at the catalyst surface is negligible except at extremely rapid rates of stirring. This system therefore provides an excellent means of establishing the effects of operating variables and mechanical construction on mass transfer coefficients in liquids in stirred reactors. It is convenient to consider the total resistance to mass transfer as consisting of two separate resistaces: in the liquid adjoining the bubbles and in the liquid adjoining the suspended solid particles; thus R = Rb + Rs.A general equation was evaluated from experimental data based upon unit volume of liquid.
    Zusätzliches Material: 14 Ill.
    Materialart: Digitale Medien
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  • 144
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 428 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Following an approach similar to that presented for the aliphatic (6, 7) and naphthenic (8) hydrocarbons, methyl-group contributions have been developed that now make possible the calculation of van der Waals' constants for aromatic hydrocarbons of considerable size and complexity. These constants are then utilized to calculate the critical temperatures, pressures, and volumes for these aromatic hydrocarbons.In addition, simple relationships have been developed that permit the evaluation of both van der Waals' constants for the unsubstituted linearly fused aromatic hydrocarbons.Comparisons of calculated critical constants with values presented in the literature for over twenty aromatic hydrocarbons produced average absolute deviations of 0.70% for the critical temperature and 2.14% for the critical pressure.
    Zusätzliches Material: 3 Tab.
    Materialart: Digitale Medien
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  • 145
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 12S 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 146
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 506-513 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: An approximate theory for the behavior of multiparticle systems suspended in a viscous fluid is developed, based on a rigorous treatment for the case of a single sphere occupying any position in a cylindrical tube. The results obtained include estimates of the effect of some of the parameters involved on the particle velocities and spatial distribution of particles in very dilute sedimenting and fluidized beds as well as on the pressure drop resulting from passage of fluid. The conclusions presented are in agreement with such experimental data as are available and suggest a basis for more exact treatment of these systems.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 147
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 449-453 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The production and refining of petroleum involve many processes in which conditions deviate markedly from equilibrium. For prediction of the behavior of such nonequilibrium systems, information concerning the molecular-transport characteristics of the paraffin hydrocarbons is of practical interest.Fick diffusion coefficients for methane were measured in the liquid phase of the methane-n-heptane system at temperatures between 40° and 340°F. at pressures up to 3,500 lb./sq. in., but the pressure range was limited at the higher temperatures by approach to the critical state of this binary system.The measurements obtained confirmed the fact that the Fick diffusion coefficients for methane decrease with an increase in the concentration of this component and increase rapidly with an increase in temperature for a constant composition. These data together with similar information for other binary paraffin hydrocarbon systems indicate that the Fick diffusion coefficients for methane decrease with an increase in the molecular weight of the less volatile component.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 148
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 454-461 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The fragmentary thermal-conductivity data for argon available in the literature have been correlated by use of a residual thermal conductivity k - k* vs. density ρ relationship. This correlation produced a unique continuous curve which was found to be singularly independent of temperature and pressure for both gaseous- and liquid-state data. From low-pressure thermal-conductivity values k* and the relationship given above, it is possible to determine thermal conductivities at any condition of temperature and pressure for which a corresponding density is available. This procedure was used to calculate reliable thermal conductivities k for high-pressure regions where experimental data were lacking.In a similar manner the critical thermal conductivity kc for argon was established directly from the critical density and the quantity kTc*. The kc value permitted the calculation of reduced thermal conductivities kR and made possible the construction of an extensive reduced-state chart. Although this correlation was developed mainly from data for argon, it was found to apply equally as well to the other inert gases as postulated from the theory of corresponding states.A comparison of thermal conductivities calculated from the reduced-state plot with over 200 experimental points produced an average deviation of 1.8% for all the inert gases. This chart was also found applicable to the diatomic gases and their mixtures but produced significant deviations for substances having more than two atoms per molecule.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
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  • 149
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 490-496 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
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  • 150
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 513-516 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A new solution is presented of the differential equations describing unsteady state heat transfer in stationary beds of small granular solid particles through which a fluid is flowing. Arbitrary initial solid temperature distribution and arbitrary variation of inlet gas temperature are allowed. The solution presented appears easier to apply in practice than those previously published and affords an example of the versatility of Fourier integrals and series. An application of the solution to the regeneration of Dow type-B butylene dehydrogenation catalyst is described.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 151
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 523-527 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: By experimental means a relation is obtained between the thermal resistance of an eddy and its angular momentum. The eddy is stationary, and no extraneous motion is present. The secondary motion which may develop in the annulus between concentric rotating cylinders is used to obtain the eddies. The fluid motion is well defined at all times and at all points of space. Heat is passed through the eddies, and the Nusselt number is obtained, which varies linearly with the angular momentum. Both Nusselt number and angular momentum vary linearly with the peripheral velocity of the inner rotating cylinder, which can be interpreted in terms of a Reynolds number associated with fluid flow perpendicular to a cylinder.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
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  • 152
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 9D-9D 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 153
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 473-479 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A new method is proposed for the calculation of the heat of vaporization of hydroxylated compounds to an accuracy of about ±0.5 kcal./mole from no more data than the molecular structure and a boiling point. The older methods, by comparison, achieved an accuracy of about ±1 kcal./mole with a far greater computational effort, since they required the (usually hypothetical) critical temperature and critical pressure in addition to a boiling point.The method is here applied to aliphatic and aromatic alcohols, to ether-alcohols (e.g., the cellosolves), and to alcohols conaining keto or aldehyde groups (e.g., salicylaldehyde) and supersedes previous correlations covering the heats of vaporization of these compounds. The method can also be used to assess the quality of vapor-pressure data of the compounds covered by it.The method is based on the assumption that the heat of vaporization consists of two terms, the dispersion energy and the hydrogen-bond increment (close but not equal to the hydrogen-bond strength). The first term is calculated from a knowledge of the heat of vaporization of the equistructural hydrocarbon, now easily available from the Tables of A.P.I. Research Project 44. The hydrogen-bond term is calculated from a set of rules given in the report.The application of the increment method of this report to other properties and other functional groups is the subject of a continuing investigation.
    Zusätzliches Material: 2 Ill.
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  • 154
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 497-505 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The theory and design of continuous stirred tank reactors are extended to the complex but industrially important field of continuous-heterogeneous-reaction systems. The present investigation is concerned with the elementary process occurring when solid particles and a liquid flow into and from a single reactor or a chain of these reactors. The equations are developed for dissolution processes, and the theoretical size distributions and specific areas are confirmed experimentally. Performance is also related to operating conditions and reactor design.
    Zusätzliches Material: 14 Ill.
    Materialart: Digitale Medien
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  • 155
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 517-522 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Vapor-liquid equilibria of the systems n-octane-Cellosolve, ethylbenzene-Cellosolve, and n-octane-ethylbenzene-Cellosolve were determined at 760 mm. Hg. The activity coefficient data of Yang and Van Winkle (23) for the system n-octane-ethylbenzene and the data of this work on other systems were expressed by Wohl's three-suffix Margules equations. The ternary data are predicted satisfactorily from the binary constants and no noticeable ternary effects seem to exist for this ternary system.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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  • 156
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 528-534 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Flow equations have been proposed for hydroextractor cakes wherein the pores are filled with moving liquid. These equations have been confirmed for the effect of each variable by use of different experimental techniques. The critical wetting rate has provided the most informative steady state, in which the cake is fed with liquid to maintain the inner surface of the liquid at radius rL coincident with that of the cake at radius rc. Transient techniques have also been used wither with a probe to time the movement of a liquid level between two radii less than rc, or with a photoelectric detector to observe the coincidence of rL = rc. The tests have proved the validity of the hydrodynamic assumptions involved in the equations and have provided both precise methods for research and practical methods for industrial purposes.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 157
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 3-10 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Since the shear rate of a non-Newtonian fluid is of importance in fixing the rheological or viscometric behavior of such a material, the present study has been concerned with the development of a general relationship between impeller speed and the shear rate of the fluid. The resulting relationship was then used to interpret and correlate power-consumption data on three non-Newtonian fluids by use of a generalized form of the conventional power-number-Reynolds-number plot for Newtonians.Flat-bladed turbines from 2 to 8 in. in diameter were used exclusively. Tank diameters ranged from 6 to 22 in. and power inputs from 0.5 to 176 hp./1,000 gal. The study encompassed a 130-fold range of Reynolds numbers in the laminar and transition regions. The results to date indicate that power requirements for the rapid mixing of non-Newtonian fluids are much greater than for comparable Newtonian materials.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
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  • 158
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 11-15 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Experimental studies of the mixing of coaxial streams of a natural gas and air at atmospheric pressure were made at Reynolds numbers of 44,000 and 79,000 under conditions where the turbulent-velocity profile of nearly uniform flow was altered as little as feasible by the blending of the two streams.Total diffusivities of natural gas in air for the region near the center of the conduit were computed from the data for turbulent, steady, nonuniform flow. The total diffusivities were found to be rather complicated functions of the conditions of flow. Limitations in the configuration of the apparatus did not permit a study of the behavior of the total diffusivities to be made over as wide a range of flow rates as would be necessary to investigate the large-scale trends indicated by this study.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
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  • 159
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 29-32 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A phase-behavior approach to the prediction of the performance characteristics of a dissolved-gas-drive reservoir is unique in that the problem of choosing flash, differential, or composite-solution gas-oil ratios and formation-volume factors has been circumvented. Data required are a compositional analysis of the reservoir fluid, the bubble point of this fluid, and the relative-permeability curves for the reservoir rock.Gas-oil ratios and formation-volume factors were calculated under conditions duplicating the performance of the reservoir. A comparison was then made between these results and those obtained by calculations involving a differential, a flash, and a composite process. A vital factor in the solution of the problem is the accuracy of the calculated equilibrium constant. Agreement within 3% was obtained when a calculated differential formation-volume curve was compared with an experimentally determined curve.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
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  • 160
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 16-28 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: One of the important factors affecting the efficiency of vapor-liquid contacting operations is the relationship between available interfacial area and contact time.Because of the difficulties in measuring these quantities, little information has heretofore been made available on them. Previous studies have been confined to extreme over-simplifications of the turbulent type of contacting taking place in fractionation devices. The present investigation consisted of the determination of interfacial area and contact time for the formation of air bubbles submerged in water and aqueous solutions. The bubbles were produced at single vertical slots and rose through a flowing liquid. In order to complete the study on physical contacting, a companion study is concerned with vapor-liquid behavior in the forth and entrainment zones. The experimental technique in this study involved taking high-speed motion pictures of the bubbling action. Measurements of the area and volume of bubbles were made at intervals during the course of their growth, and values of total contact time and average interfacial area per unit volume of vapor are presented.It was found that both the average interfacial area per unit volume of vapor a and the total contact time tm were primarily affected by the head of flowing liquid on the slot. Below slot submergence of approximately 2.5 in. of liquid, interfacial area was shown to decrease with increasing slot submergence and increasing slot area. Above 2.5 in. of liquid, interfacial area was a function of skirt clearance, liquid viscosity, and surface tension.Total contact time was found to increase with increasing slot submergence and to decrease with increasing vapor rate and skirt clearance.Through the use of an integrated mass transfer-rate equation, the terms a and tm can be used in conjunction with the appropriate mass transfer coefficient for predicting the point efficiencies on bubble-cap plates.
    Zusätzliches Material: 13 Ill.
    Materialart: Digitale Medien
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  • 161
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 33-36 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Experimental equilibrium vapor and liquid compositions are reported for the hydrogen-methane system at -150°, -200°, and -250°F. and at pressures of 500 to 4,000 lb./sq. in. The ternary system hydrogen-methane-propane was studied at 0°, -100°, and -200°F. at 500 and 1,000 lb./sq. in. Phase compositions were determined for a limited number of similar conditions for the hydrogen-methane-propylene and hydrogen-methane-ethylene-ethane-propylene-propane systems.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
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  • 162
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 37-42 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Data are reported for the evaporation of spheres of naphthalene into air, helium, carbon dioxide, and Freon-12, and of liquid diethyl adipate into air at pressures from 0.1 to 3,000μ Hg and at Reynolds numbers from 0 to 1.37. By use of suitable values of the surface-evaporation coefficient and the assumption of additivity of surface evaporation and diffusional resistances, the data are well correlated. The results lend semiquantitative support to the theory of sublimation of crystals developed by Stranski.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
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  • 163
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 43-48 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Rates of mass and heat transfer to single spheres and cylinders at low Reynolds numbers are predicted from boundary-layer theory. The velocity distributions which are assumed to exist are those derived from the linearized Navier-Stokes equations by Tomotika and Aoi.In the case of the sphere the Nusselt number is found to be a function only of the Peclet group when the Stokes streamline function is assumed to apply. Experimental data for mass and heat transfer to singel spheres fall 10 to 40% higher than predicted from the theory. Experimental data for heat and mass transfer to single cylinders at large NPe check the theory.Curves are also plotted for the efficiency of removal of colloidal particles by combined direct interception and diffusion for both spheres and cylinders.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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  • 164
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 63-68 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 165
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 56-62 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Liquid extractions of benzoic acid-toluene solutions by means of water were studied under varying flow rates of both solvents in a 2-in. perforated-plate column to which pulsations of different frequencies and amplitudes were applied. Studies on reversal of the phase of the dispersion were made. With fixed flow rates of both solvents, the rate of extraction increased much more rapidly when the flow through the perforation became turbulent. The results are correlated by means of Reynolds number based on the flow through the perforations and are calculated from the product of the frequency and amplitude of the pulsations.
    Zusätzliches Material: 16 Ill.
    Materialart: Digitale Medien
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  • 166
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 49-55 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Heat transfer coefficients were measured experimentally for carbon dioxide in turbulent flow in an 0.18-in. I.D. pipe. The pressure was 1,200 lb./sq. in. abs. and the bulk temperature varied from 70° to 120°F. In this critical region the coefficients between fluid and tube wall ranged from 300 to 2,600 B.t.u./(hr.)(sq. ft./°F.) over a Reynolds number interval of 30,000 to 300,000.Existing empirical and semitheoretical correlations were found inadequate in this region, where the thermal conductivity, viscosity, density, and specific heat are all varying rapidly and nonuniformly with temperature. A method of integrating the heat and momentum transfer equations with variable physical properties, recently proposed by Deissler, was applied to the experimental data and found to fit well. The application required extensive calculations, which were carried out with an Electrodata digital computer.A simplified procedure was proposed for estimating heat transfer coefficients in the critical region by using a semitheoretical equation developed for zero heat flow. Simple rules were suggested for estimating the temperature at which to evaluate the physical properties when this equation is applied to the realt case of finite heat transfer. The method worked well when compared with the computed heat transfer coefficients of Deissler for supercritical wate but showed about 30% deviation when compared with the carbon dioxide results. This discrepancy is believed due to the fact that the carbon dioxide was very close to the critical point (reduced pressure = 1.1) but the water was somewhat further removed (reduced pressure = 1.6).
    Zusätzliches Material: 15 Ill.
    Materialart: Digitale Medien
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  • 167
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 69-74 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Carbon tetrachloride was evaporated into a stream of air over ranges of gas concentration from 0 to 0.70 mole fraction carbon tetrachloride, Reynolds number from 600 to 15,000, and Schmidt number from 0.23 to 1.17. The data were correlated by an equation and also by a computer solution to the differential equation describing mass transfer from values of eddy viscosity and eddy diffusivity obtained from the literature.
    Zusätzliches Material: 12 Ill.
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  • 168
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 75-82 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The equations and graphs presented here for the vapor-liquid equilibrium of the nitrogen-argon-oxygen low-temperature system are based on published binary and ternary experimental data involving mixtures of nitrogen, argon, and oxygen, and on careful thermodynamic study over a period of years of accurate plant-performance data on tall, large air-rectifying columns operating near the minimum reflux ratios. The plants have achieved separations that are impossible according to some of the published equilibrium data, and thus the plant data have made a major contribution toward the preparation of this paper.
    Zusätzliches Material: 13 Ill.
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  • 169
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 147-152 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Experimental data are presented for the heats of mixing of liquids at 25°C. and 1 atm. pressure for ten binary and five ternary systems. For nonpolar binary systems a two-constant equation has been developed which correlates the data within experimental accuracy. Several equations which have been proposed for the calculation of ternary heats of mixing from binary data are tested for the systems studied. The method of Jost and Röck (4) for determining the constants in power-series functions from experimental data is considered.
    Zusätzliches Material: 8 Ill.
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  • 170
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 161-164 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The densities of acetone-water liquid solutions have been measured over the entire composition range from 20°C. to within 3° to 7°C. of the normal boiling point of the mixture. The density was measured with a Robertson pycnometer (13), which was modified slightly. The density values are thought to be accurate to within ±0.00005 density units. The technique for determining density values of the volatile mixture near the boiling temperature is given in some detail. The refractive index (nD25) of pure acetone has been redetermined and equals 1.35596 ± 0.00003.
    Zusätzliches Material: 6 Ill.
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  • 171
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 165-171 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: New absorption- and stripping-factor functions have been developed for use in computing multicomponent separations in fractionators, reboiled absorbers, refluxed strippers, and columns with side-stream strippers. Charts of fraction not absorbed vs. A factor and fraction not stripped vs. S factor are included with the equations for these operations.These functions and procedures are of particular advantage in computing complex columns, i.e., two or more feeds and three or more products, where the proposed A and S factor equations provide a method for converging on a solution.
    Zusätzliches Material: 7 Ill.
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  • 172
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 180-182 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Concentration relations between foams and their residual liquids (frothates) have been examined.Clean air streams of 88, 91, and 96% water saturation were bubbled into aqueous solutions of isobutyl alcohol. The concentration of the alcohol in the collected and collapsed foam was plotted against its concentration in the bulk liquid.Varying the saturation of the air stream resulted in both positive and negative enrichment of the foam with the surface-active alcohol. This suggests that where froth-frothate-concentration relations are unfavorable, a change in operating conditions may advantageously affect these relations and allow the mixture to be foam separated.
    Zusätzliches Material: 5 Ill.
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  • 173
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 191-197 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Vapor-liquid equilibria of two binary systems, benzene-n-hexane and benzene-cyclohexane, were measured at pressures from 4 to 18 atm. The three-constant Redlich-Kister equation was found satisfactory for correlation.With the benzene-n-hexane system no azeotrope occurred; with the benzene-cyclohexane system an azeotrope appeared, and the mole fraction of cyclohexane in it diminished with increase in pressure. Lack of correction for fugacity in the vapor phase introduced a maximum error of 4% in activity coefficients at highest pressure.
    Zusätzliches Material: 15 Ill.
    Materialart: Digitale Medien
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  • 174
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 213-222 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Data were obtained in flat-plate continuous-flow thermogravitational columns to check the theory developed by Furry, Jones, and Onsaer and a modification of this theory proposed by the authors. Separations of ethyl alcohol-water and benzene-n-heptane mixtures were measured, flow rate, column length, temperature difference, spacing between plates, and inclination of the plates being varied in the experiments. Theory and data are in qualitative agreement for the range of variables studied. Quantitative agreement exists between theory and experiment in the region of practical design for liquid-thermal-diffusion plants.Equations to aid in the design of thermal-diffusion plants are developed, and a plant to treat 1,000 bbl./day of a liquid aromatic-aliphatic mixture is designed and costs are estimated.
    Zusätzliches Material: 13 Ill.
    Materialart: Digitale Medien
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  • 175
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 230-235 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Reaction kinetics for the catalytic dehydrogenation of sec-butyl alcohol to methyl ethyl ketone has been investigated at atmospheric pressure and temperatures ranging from 650° to 750°F. in the presence of solid brass spheres, 1/8 in. in diameter. The nature of this catalyst permitted a direct evaluation of the surface involved in this reaction and allowed the definition of a surface-feed ratio to be expressed as S/F in place of the conventional weightfeed ratio W/F commonly used in catalytic studies. Feed compositions ranged from secbutyl alcohol to mixtures containing high percentages of methyl ethyl ketone and hydrogen.In these studies mass transfer effects were found to be significant and, for a proper representation of conditiated at the catalyst surface, must be taken into account. The effect of feed compositions on the initial rates of reaction showed that the rate-controlling step was the desorption of hydrogen involving a single-site mechanism.In addition, the results of these studies have been used to produce values of height of reactor unit HRU which have been found to correlate with mass velocity and temperature. The HRU provides a simple means of calculating the depth of catalyst necessary to effect a designated conversion.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
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  • 176
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 223-229 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A radioisotope technique has been utilized to study the point holdup of the dispersed phase and some operational flow characteristics in a packed countercurrent liquid-liquid extraction tower. The system used was toluene-water and the packing was Raschig rings. The toluene dispersed phase was tagged with gamma-radiating iodine-131.The study revealed that holdup experiences a hysteresis cycle with variations of the continuous-phase flow rate. Correlating equations are presented for “total” and permanent holdup, below loading, to account for this hysteresis. Entrance effects and flow maldistribution effects are readily determined by the method utilized. Displacement studies demonstrated that no simple “operational” dispersed-phase flow holdup exists, but rather a complex dispersed-phase movement, which involves all the “nonhysteresis” permanent holdup.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
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  • 177
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 248-256 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 178
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 262-267 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: In spite of the importance of hydrogenation procesing operations in the refining of petroleum there are only limited experimental volumetric and phase equilibrium data concerning mixtures of hydrocarbons and hydrogen. An investigation of the volumetiric and phase behavior of the hydrogen-n-hexane system was therefore undertaken.The experimental study involved measurements of the specific volume of four mixtures of hydrogen and n-hexane at eight temperatures between 40° and 460°F. for pressures up to 10,000 lb./sq. in In addition, the composition of the gas phase in heterogeneous mixtures was determined at six temperatures within the interval mentioned above for pressures as high as 10,000 lb./sq. in.Little about this system was found to be qualitatively unusual except that the critical pressure exceeded 10,000 lb/sq. in. at all temperatures below 340°F. As would be expected, the dew-point gas was rather lean in n-hexane for temperatures below 220°F. and at pressures above 100 times the vapor pressure of n-hexane throughout the pressure range covered by this study.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 179
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 299-304 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The interaction between a turbulent air stream and a water film flowing parallel to it was studied. The variables explored were the liquid flow rate, the gas flow rate, and the film height. The data were correlated in terms of a liquid and a gas Reynolds number. Thinner films or films having a lower Reynolds number were more stable. For the experiments reported in this research the transition from a smooth surface to a surface possessing two-dimensional waves occurs at hUτρliquid/µliquid of about 520. Transition from two-dimensional waves to a “pebbled” surface occurs at a value of this parameter of about 600. Theories presented in the literature for the initiation of waves on a liquid surface do not adequately describe the experimental results.
    Zusätzliches Material: 14 Ill.
    Materialart: Digitale Medien
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  • 180
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 318-320 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: This paper presentes a correlation to predict the equilibrium ratios of hydrogen in hydrocarbon mixtures by use of the parameters of pressure and convergence pressure. Also a procedure to predict convergence pressures of hydrogen-containing mixtures was developed from a correlation of critical loci. With the predicted convergence pressure the measured values of hydrogen equilibrium ratios in binary hydrogen-paraffin mixtures were predicted with a statistical deviation of 8.1% for 237 measurements. Including hydrogen-olefin and multicomponent mixtures of hydrogen, paraffins, and olefins, the statistical deviation was found to be 11.3% for a total of 375 comparisons with measured values of hydrogen equilibrium ratios.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 181
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 325-329 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The surface tensions against air of acetone-water solutions have been measured over the entire composition range from 20°C. to generally within 1° to 10°C. of the normal boiling points. The capillary-height method was employed and the results are thought to be accurate to better than ±0.5%.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 182
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 343-347 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Constant layer moisture at the hot surface is found to exist during the constant-rate period of drying of sand on a hot surface in still air. It accounts not only for the constantrate period of drying itself but also largely for the length of the period.Temperature of the air-surface interface usually has minor effects on the rate of vaporization because equilibrium between vapor and the bed is not established during periods of rapid vaporization.Numerical relationships have not been established.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
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  • 183
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 361-365 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Two-phase critical flow of steam-water mixtures has been investigated over a pressure range from 4 to 43 1b./sq.in. abs. and a quality range from saturated vapor to 1% (weight) vapor. Discharges were measured from 1/4-,1/2-, 3/4-, and 1-in. pipes and from annuli of intermediate cross-sectional areas. The experimental mass flow rates are always grteater than the values calculated on the basis of a homogeneous flow model. Several empirical methods for correlating the data were determined, and comparisons are presented of the predictions of several analytical flow models.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
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  • 184
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 373-381 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Applying both their own assumptions and the mechanism of lateral mixing proposed by Ranz (20), the authors obtained theoretical formulas for effective thermal conductivities ke in packed beds. Previously reported experimental data were analyzed with these equations, and the usable data for predicition of ke were shown.In order to see the influence of both packing characteristics and temperature on the effective thermal conductivities, experimental data were obtained with air for beds with various kinds of packing, i.e., iron spheres, porcelain packings, cement clinker, insulating fire brick, and Raschig rings. Correlation of these data with Equation (15) showed that this equation adequately expressed the heat transfer mechanisms in packed beds with motionless gases, especially at hight temperatures.
    Zusätzliches Material: 18 Ill.
    Materialart: Digitale Medien
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  • 185
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 391-394 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A rigorous method is presented for the evaluation of the heat requirements in binary batch fractionations which involve negligible column hold up. The method, in which the additional variables of the discontinuous process are taken into account, is a modification of the methods of Ponchon and Savarit for continuous operation. Two examples, one for a fractionation in which the composition of the product is constant and the other in which the reflux ratio is constant, are given as illustrations of the method.The application of the method permits more accurate evaluation of reboiler and condenser heat loads and, in turn, better design.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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  • 186
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 276-279 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: On the assumption of laminar Newtonian flow, flow profiles are developed for both the vertical plate and cylindrical column by use of classical equations. From the flow profiles the mass transport, vertical pressure gradient, and optimal design parameters are calculated. With the Reynolds-number criterion used to ascertain the maximum nonturbulent velocity, minimal values for the plate distance and column radius can be calculated. An example is included for each case.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 187
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 268-275 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Values of total pressure drop are presented for the flow of vaporizing water in an internally heated 1-in. I.D. by 1½-in. O.D. annulus at mass velocities of 270 to 1,440, lb./(sec.)(sq.ft.), pressures of 9 to 180 lb./sq. in., and up to 0.34 fraction by weight vaporized. The total heated length over which boiling took place was as large as 6 ft. There is no evidence of “sonic” pressure jumps at the outlet. The results for the annulus mentioned lie within +30 to -11% of the Lockhart-Martinelli curve at higher qualities and with ±45% of the correlation at lower qualities where the actual quality is more uncertain. A simplified correlation in terms of quality and volume fraction of liquid predicted the two-phase frictional pressure drops with an average error of 41%.It was found that the ratio of the two-phase pressure drop through a 0.3-in. orifice to the drop with no vaporization was approximately a linear function of the quality in the vena contracta but was only one tenth to one third as great as would be predicted if the mixture were to expand as a homogeneous fluid. Prediction of orifice presure drops is improved if slip between vapor and liquid is considered.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
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  • 188
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 286-288 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The separation of 4.5 g. of americium from approximately a kilogram of light rare earths (primarily lanthanum) was achieved on a pilot plant scale by chromatographic displacement of the mixture from Dowex-50 resin with 0.1% ammonium citrate at pH 8 into hydrogen-form Dowex-50. The americium collected into a narrow band and was eluted free from lanthanum but contained an equal weight of cerium. A 6- and a 2-in.-diam. column were used in tandem. Use of a final column with a much smaller diameter would have permitted a cleaner separation from cerium, but this was left for a laboratory-scale separation by a different process. Precipitation, which was observed in the columns during the first runs, was later avoided entriely by use of high flow rates both initially and during the transfer between columns. No adverse effects were noted from ∼15 curies of alpha activity.
    Materialart: Digitale Medien
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  • 189
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957) 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 190
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 305-312 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The design variables that affect the pressure drop across dry perforated plates were determined and correlated. Average orifice coefficients were calculated for the perforated plates by using a modified form of the single-orifice flow equation.The variables which affected the orifice coefficients were found to be the hole diameter, hole pitch, plate thickness, fraction of the plate covered by the perforated area, and a Reynolds number based on the hole diameter. The orifice coefficients have been correlated with these variables in dimensionless groupings.The correlation presented covers a practicable range of variables for which the pressure drop may be predicted in design.
    Zusätzliches Material: 22 Ill.
    Materialart: Digitale Medien
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  • 191
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 484-489 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Pressure drop due to fluid friction has been measured in a smooth tube; in six smooth concentric annuli; and between smooth, parallel, flat plates. The data cover the viscous, transition, and lower turbulent ranges of flow. Friction factors are in agreement with theory in the viscous range and can be correlated uniquely in the fully turbulent range by means of a modified hydraulic radius concept. Limits of the transition region in annuli are functions of the ration of inner and outer radii. Correlations in the fully turbulent range permit friction factors for the noncircular ducts to be predicted within the uncertainty of smooth-tube data. Such factors can be used for the prpose of correlating other variables as well as for direct calculation of pressure drop.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 192
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 439-442 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The problem of axial mixing in straight pipes is analyzed by a modification of G. I. Taylor's analysis. The treatment presented here includes the effect of both Schmidt and Reynolds numbers throughout the turbulent-flow range. All applicable data on flow of gases and liquids are found to confirm the validity of the method.The analysis indicates that axial mixing increases rapidly as the flow approaches the laminar region, especially for liquids, and that pipe roughness causes a relatively small increase in axial mixing. Turbulent eddy diffusion in the axial direction has a negligible effect.The results of the analysis are applicable to those systems wherein the kinematic viscosity of the flowing mixture does not vary greatly from one region to another and in which the concentration region of interest is spread out along a sufficient length of pipe. These limitations are broad enough to permit most practical problems to be treated by the method.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
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  • 193
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 535-538 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The problem of diffusion in a moving medium with given motion of the boundaries is considered. The method presented yields the analytical solution to any desired degree of accuracy provided that solutions for certain associated problems of diffusion in a medium at rest with boundaries at rest are known. The method is applied to the analysis of partial and approximate solutions previously presented for the one-dimensional case of a spherical cavity in a liquid with radial boundary motion induced by evaporation.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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  • 194
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 195
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 395-404 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 15 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 196
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 418-427 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The effects of the physical properties and volume flow rate of liquids on the surface area of sprays produced by a pressure type of atomizing nozzle were determined experimentally. the specific surface area of the sprays is correlated by an equation of two dimensionless groups in terms of the variables surface tension to the -1.0 power, kinematic viscosity to the -0.4 power, and volume flow rate to the 2.4 power. The volume flow rate is correlated by an equation of two dimensionless groups containing the variables viscosity to the 0.17 power, density to the -0.58 power, and spray pressure to the 0.42 power. The conversion of compression energy to surface-area energy appears to be constant at approximately 0.1%.
    Zusätzliches Material: 19 Ill.
    Materialart: Digitale Medien
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  • 197
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 9S 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 198
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 431-431 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 199
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 443-448 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A method is presented for the analysis of a reaction between a porous solid and a gaseous reactant where the kinetic expression is linear in the concentration and where appreciable concentration gradients are established in the pore system as a result of diffusive transport rate. Two cases are treated mathematically: a single cylindrical pore initially of uniform diameter and a porous solid initially containing uniform cylindrical pores with random intersections. The mathematical solutions to the latter case are used to interpret the experimental results reported in the literature on the gasification of graphite rods with carbon dioxide. Values of the computed effective diffusivity are an order of magnitude smaller than the bulk diffusivity at the same temperature and pressure.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
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  • 200
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 467-472 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Previous papers have reported equilibrium data for the binary systems cyclohexaneheptane, heptane-toluene, and cyclohexane-toluene. This present study gives similar data for the ternary system cyclohexane-heptane-toluene and compares the activity coefficients with those predicted from the three limiting binaries.The ternary activity coefficients fall well in line between the limiting-binary data. Distribution is about as would be predicted by the ternary Margules equations. As an approximation, if the coefficients are plotted as a function of the aromatic concentration only, without consideration of the ratio of naphthenes to paraffins, reasonably good correlation is observed.
    Zusätzliches Material: 13 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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