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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 23 (1999), S. 701-708 
    ISSN: 1476-5535
    Keywords: Keywords: ethanol; recombinant; E. coli KO11; lignocellulosic; chemostat; stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Differing claims regarding the stability of the recombinant ethanologen E. coli KO11 are addressed here in batch and chemostat culture. In repeat batch culture, the organism was stable on glucose, mannose, xylose and galactose for at least three serial transfers, even in the absence of a selective antibiotic. Chemostat cultures on glucose were remarkably stable, but on mannose, xylose and a xylose/glucose mixture, they progressively lost their hyperethanologenicity. On xylose, the loss was irreversible, indicating genetic instability. The loss of hyperethanologenicity was accompanied by the production of high concentrations of acetic acid and by increasing biomass yields, suggesting that the higher ATP yield associated with acetate production may foster the growth of acetate-producing revertant strains. Plate counts on high chloramphenicol-containing medium, whether directly, or following preliminary growth on non-selective medium, were not a reliable indicator of high ethanologenicity during chemostat culture. In batch culture, the organism appeared to retain its promise for ethanol production from lignocellulosics and concerns that antibiotics may need to be included in all media appear unfounded.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0703
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract. Cytological and biochemical alterations of crucial carp (Carassius auratus) hepatocytes were characterized after exposure to sediments from a lake contaminated with dioxins and other industrial chemicals. Carp were exposed in 20 L water containing 25, 50, or 100 g of contaminated sediment for 2 and 4 weeks. Ultrastructural changes in the liver were characterized by severe enlargement of hepatocytes. Alterations in the cell included formation of condensed and irregular cell nucleus, polynuclei, dispersed heterochromatin, enlargement of the nucleolus, and degeneration of the nucleus. Mitochondrial numbers were reduced and cristae were deformed. Myelin figures and lysosomes were increased, and sometimes cell organelles and cell matrix were totally lost after 4 weeks of exposure. The ultrastructural alterations were correlated with exposure time and sediment concentrations. Hepatosometic index was significantly increased in experimental groups at 2 and 4 weeks as compared with the control group. EROD enzyme activities were strongly induced in liver. A trend from rough endoplasmic reticulum (RER) to SER was observed. Our results suggest that the dioxin-like compounds bound by sediment were bioavailable to C. auratus and cause sublethal effects.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 58 (1999), S. 487-493 
    ISSN: 1572-8943
    Keywords: non-isothermal kinetics ; quaternary ammonium ; tetraphenylborate ; thermal decomposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A new compound cyclohexyl-t-butyldimethylammonium tetraphenylborate, [C6H11N(CH3)2(C(CH3)3)]BPh4 has been prepared, and its decomposition mechanism was studied by TG. The IR spectra of the products of thermal decomposition were examined at every stage. Kinetic analysis for the first stage of thermal decomposition process was obtained by TG and DTG curves, and kinetic parameters were obtained from the analysis of the TG-DTG curves with integral and differential equations. The most probable kinetic function was suggested by comparison of kinetic parameters.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 18 (1999), S. 783-784 
    ISSN: 1573-4811
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 15 (1996), S. 129-131 
    ISSN: 1573-4811
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Wood science and technology 33 (1999), S. 299-310 
    ISSN: 0043-7719
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  The radial direction loss factor of full-size western hemlock sapwood and heartwood, as well as western red cedar heartwood timbers was measured using the direct calorimetric method with a laboratory-scale radio frequency/vacuum dryer at the frequency of 13.56 MHz, moisture content range between 10 and 80%, temperature range between 25 and 55 °C, and root mean square (rms) electrode voltages of 0.8 and 1.1 kV, respectively. The results indicated that the moisture content, temperature, electric field strength and wood type significantly affected the loss factor. Empirical regression equations were derived based on the experimental data that made possible the calculation of the loss factor and power density within wood during RF heating.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    International journal of thermophysics 20 (1999), S. 743-753 
    ISSN: 1572-9567
    Keywords: CCD ; contactless ; dilatometer ; foil ; thermal expansion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A contactless, compact, low-cost dilatometer based on a laser-pulse thermal-conductivity apparatus has been developed to measure the linear thermal expansion of foil materials. The two sample-edge images are projected onto the array of a charge-coupled device (CCD). Changes in sample length are determined from measurements of the corresponding displacements of the sample-edge images focused on the CCD. The dilalometer performance was tested by comparing results of measurements of the thermal expansion for pure copper with published data. The linear thermal expansion of an L-16-type foil of 20-μm thickness, which is a candidate material for thermocontrol layers (in engineering), was measured with the apparatus.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Biotechnology letters 21 (1999), S. 175-178 
    ISSN: 1573-6776
    Keywords: Phaffia rhodozyma ; carotenoid ; astaxanthin ; fed-batch culture ; fermentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The growth and carotenoid production of Phaffia rhodozyma in fed-batch cultures with different feeding methods and grown at specific growth rates similar to the batch culture was compared. With constant feeding, exponential feeding, DO-stat and pH-stat fed-batch cultures of Phaffia rhodozyma, the highest biomass (17.4 g/l) and lowest carotenoid content (307 μg/g cell) of Phaffia rhodozyma was from the DO-stat fed-batch culture. The lowest biomass (14.7 g/l) and highest carotenoid content (412 μg/g cell) was from the exponential, fed-batch culture.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 33 (1998), S. 2147-2152 
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A super-hybrid (natural composite/fibre-reinforced composite/metal hybridization) ecomaterial, reformed bamboo/glass fabric/aluminium (RB/GF/Al) was developed. The addition of a sparse glass fabric/epoxy resin layer between reformed bamboo and aluminium proved to be effective in increasing the compressive, tensile strength of the composite material. In particular, the interfacial shear strength between the reformed bamboo and aluminium was improved, and was the transverse tensile strength. These were the major shortcomings of normal bamboo and reformed bamboo/aluminium composites. The good recyclability of reformed bamboo and aluminium make RB/GF/Al an environmentally friendly material. Extensive use of such an ecomaterial instead of wood would save natural forest resources. © 1998 Chapman & Hall
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Mechanics of time-dependent materials 2 (1998), S. 103-111 
    ISSN: 1573-2738
    Keywords: dynamic response ; Epon 828 ; T-403 ; epoxy ; high-strain rate test ; Hopkinson bar ; material modeling ; strain-rate effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The uniaxial compressive mechanical response of an epoxy, Epon 828/T-403, was experimentally, measured over a strain-rate range of 1.1 × 10-4 to 5.2 × 103 s-1. A modified split Hopkinson pressure bar was employed to apply dynamic compressive loading over a very short time of ∼ 0.2 millisecond, whereas an MTS was used to conduct quasi-static experiments at a duration of 0.2 to 2,000 seconds to determine strain-rate sensitivity. The experimental results show that the compressive strength of the epoxy increases with increasing strain rate until adiabatic heating offsets the strain-rate hardening. A constitutive model based on the Johnson–Cook model was constructed to describe the stress-strain behavior of the epoxy at the strain rates tested. A Ludwig equation was modified to model the stress-strain behavior at a reference strain rate, which included elastic deformation, a yield-like peak, and a strain-softening region. A hyperbolic tangent function provided a good description of the strain-rate effect. The material constants in this proposed model were determined using the experimental results.
    Type of Medium: Electronic Resource
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