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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 25 (1969), S. 238-253 
    ISSN: 1432-0738
    Keywords: Parathion ; Parathion Toxicity ; Pesticides ; Pesticide Toxicity ; Protein Deficiency ; Parathion ; Toxicität von Parathion ; Schädlingsbekämpfungsmittel ; Toxicität der Schädlingsbekämpfungsmittel ; Eiweißmangel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die akute perorale Toxizität von Parathion (98,5% technisch) wurde an jungen, männlichen Albino-Ratten bestimmt. Die Tiere in Gruppe I erhielten eine gereinigte Diät, in der Eiweiß als Casein in sehr geringen Mengen (3,5%) enthalten war, in Gruppe II die gleiche Nahrung wie Gruppe I, jedoch mit Casein in normaler Menge (26%), und in Gruppe III die übliche gepreßte Trockennahrung (Chow). Die LD50±S.F. betrug in Gruppe I 4,86±0,31 mg/kg Körpergewicht, 37,1±4,9 mg/kg in Gruppe II, und 23,4±5,4 mg/kg in Gruppe III. Das klinisch-pathologische Vergiftungssyndrom war im wesentlichen in allen 3 Gruppen gleich. Die klinischen Manifestationen umfaßten: Haaraufrichtung, Diarrhöe, Sialarrhoe, Dakryorrhoe, Hemodakryorrhoe, Nasenbluten, Exophthalmus, Zittern, Hyporeflexie, Lustlosigkeit, Ataxie, Anorexie, Oligodipsie, Körpergewichtsverlust, Oligurie, Albuminurie, Hematurie, und Glykosurie. Die meisten Todesfälle traten nach 10–35 Std ein. Bei der Autopsie fanden sich geringe akute Enteritis, ausgedehnte Erweiterung der venösen Capillaren, degenerative Veränderungen in Leber und Nieren und Wasserverlust und Gewichtsverlust der Körperorgane. Die Überlebenden schienen nach 4 Tagen wieder normal zu sein, die Organgewichte sowie der Wassergehalt lagen nach 2 Wochen und nach 1 Monat in den Normbereichen.
    Notes: Summary The clinicopathological syndrome of acute oral toxicity to parathion (98.5% technical) was determined in male albino rats fed for 28 days from weaning on a diet containing 3.5% protein as casein (group I), normal amounts of protein as casein (26% group II), and normal amounts of mixed natural protein as laboratory chow. The LD50±S.E. was found to be 4.86±0.31 mg/kg in group I, 37.1±4.9 mg /kg in group II and 23.4±5.4 mg/kg in group III. The LD50 in group I was significantly lower than that in group II which, in turn, was significantly higher than that in group III. Most deaths occurred at 10–35 hours in all three groups. The clinical syndrome of intoxication was essentially the same in all three groups and included signs of cholinergic stimulation such as diarrhea, sialarrhea and dacryorrhea, of stimulation of the central nervous system such as piloerection, tremors, and exophthalmos, alternating with signs of depression of the central nervous system such as hyporeflexia, drowsiness, ataxia, prostration and pallor. These signs were accompanied by anorexia, oligodipsia, hypothermia, loss of body weight, oliguria, proteinuria, hematuria and glucosuria. At autopsy there were found a very mild local irritant gastroenteritis, vascular congestion of many organs, a contracted spleen and, when death was delayed, gastric ulcers and degenerative changes in organs such as the liver and kidneys. Most organs were dehydrated and had lost weight. The survivors appeared normal by the 4th day but there was a persistent hematuria, glucosuria and proteinuria. Organ weights and water contents were mostly within normal limits at 2 weeks and 1 month but autopsy at these intervals occasionally disclosed healed or healing abscesses, indicating that resistance to infection had been lowered by parathion, and other residual changes such as a megacolon and hydrated muscle.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 42 (1996), S. 2668-2682 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A bioartificial pancreas, consisting of immobilized islets encapsulated within hollow fibers, is investigated as an alternative treatment for insulin-dependent diabetes. A mathematical model is developed to determine whether this configuration of the bioartificial pancreas can yield an insulin response to a glucose challenge with the appropriate dynamics in diabetic humans. The model consists of the 2-D mass-conservation equations for glucose and insulin within the hollow fiber and capillaries. The equations contain terms for insulin-production kinetics by porcine islets and glucose-consumption kinetics. The boundary conditions account for transport resistances of the fiber membrane, the tissue surrounding the implant, and a thin film within the capillaries. The equations are coupled to a pharmacokinetic model of the circulatory system. The calculations show that an optimized design with this configuration will be feasible for human use and requires a total volume of 4.6 mL to reach the target insulin concentration in the bloodstream following a glucose challenge. The parameters and processes controlling the system performance are discussed.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 32 (1986), S. 163-166 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 22 (1976), S. 463-471 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A computer model was developed for tubular high-pressure polyethylene reactors. Plug flow and absence of axial mixing were assumed. Emphasis was placed on realistic modeling of the reaction kinetics and the variation of physical properties along the reaction coordinate. A good simulation of axial temperature profiles, conversion, molecular weights, molecular weight distribution, and transport properties along the reaction coordinate is believed to have been achieved. The model can be extended readily to cases where radial diffusion is significant.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 29 (1989), S. 69-76 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Mechanical properties, deformation modes under both uniaxial tension and compression, low temperature mechanical relaxation behavior, and resistance to fracture under dynamic loading have been investigated for a medium impact grade of polystyrene, Shear yielding is the dominant mode of plastic deformation in compression while matrix crazing, together with some tearing and cavitation of the rubber phase, occurs in tension. The craze microstructure, as determined by transmission electron microscopy (TEM), is typical of that noted in polystyrene, with sharp craze-bulk interfaces and a characteristic midrib section. The presence of a third phase, possibly a processing aid, is evident in the TEM scans and in the dynamic mechanical data. The present data, together with the data obtained on polystyrene and on high impact polystyrene, are used to show the strong influence of rubber content on various mechanical properties, such as the tensile craze yielding stress, ductility, compression yield strength, degree of strain softening, and fatigue durability.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 34 (1994), S. 472-476 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Because of differences in chemical structure and rheological characteristics, high density polyethylene (HDPE) and poly(ethylene terephthalate) (PET) are incompatible when blended during recycling of PET soft drink bottles. To improve the properties of the blends, ethylene vinyl acetate copolymer (EVA) was used as a compatibilizer. Based on torque rheometer tests, the higher the concentration of PET in the blends, the higher the initial loading torque. Blends of 50% HDPE and 50% PET had the lowest equilibrium torque. Equilibrium torque was highest at 5% EVA. The presence of EVA made only a slight difference in the glass transition temperatures of HDPE/PET blends. Higher EVA content in the blend resulted in a lower melting endotherm. Thermogravimetric analysis showed that thermal stability was independent of EVA content; but the more PET in the blend, the lower the final weight loss.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A series of polished polystyrene specimens, coated with silicone oil, were tested in tension and in tension-compression fatigue cycling at 21 Hz. Oils of four different viscosities, ranging from 5 cSt to 1000 cSt, were utilized. The craze initiation stress and the tensile fracture stress both increased with the increase of oil viscosity. For the 1000 cSt oil, the stress-strain curve was essentially the same as that of an uncoated sample. The average lifetime to fracture in the fatigue tests depends upon the stress amplitude and on the oil viscosity. For the 1000 cSt oil, the fatigue behavior is similar to that of uncoated samples, except at high imposed stresses, where lifetime is somewhat lower. For the low viscosity oil, the average lifetime is from one to two decades less than for uncoated samples. Discussion is given of the influence of stress amplitude and oil viscosity on the test results and on the morphology of the fracture surfaces.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 30 (1990), S. 1574-1584 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A sound wave extrusion system has been developed. This system includes a single screw extruder and an annular die having an internal surface oscillating in the sound frequency range. Oscillating shear flow has been imposed in the direction parallel to the main pressure flow. The die characteristics and average melt temperature at the exit from the die for several thermoplastics have been measured with and without imposition of oscillations. Modeling of parallel superposition of sound oscillations upon pressure flow has been performed using the Leonov viscoelastic constitutive equation. Three cases are considered: (i) the process is isothermal and the change in die pressure is only due to a nonlinear interaction of oscillatory and pressure flow; (ii) the process is nonisothermal and adiabatic, and pressure reduction is due to the nonlinear interaction and the dissipation of oscillatory energy leading to the temperature rise in polymer melts; (iii) the process is nonisothermal with heat transfer due to transient heat conduction and the dissipation of oscillatory energy. Pressure reduction occurs due to both nonlinear interaction and temperature rise. It is found that case (i) cannot explain the observed die pressure reduction, while case (ii) describes those data only at high flow rates. The theoretical results from case (iii) are found to be in qualitative agreement with experimental observations. Generally, the theoretical results of case (iii) are better than those of cases (i) and (ii).
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 24 (1984), S. 786-797 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The performance of styrene-acrylonitrile copolymers under alternating stresses has been examined. Information has been obtained concerning the influence of acrylonitrile content and of molecular weight on thermal effects due to hysteresis, on cyclic lifetime to craze initiation, on average cycles to fracture, and on fatigue fracture surface morphology. The influence of an elastomeric second phase has been determined by comparing fatigue performance under comparable conditions of both styrene-acrylonitrile (SAN) and acrylonitrile-butadiene-styrene (ABS). The stress concentrating effects of the rubber particles cause earlier initiation of fatigue-induced damage and lower fatigue fracture resistance. The fatigue-induced specimen temperature rise is greater in ABS than SAN and it increases linearly with test frequency and as the square of the stress amplitude. The fracture surface morphology of ABS, which differs from that of unmodified SAN and also from that of rubber modified polystyrene, is discussed.
    Additional Material: 25 Ill.
    Type of Medium: Electronic Resource
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