Materials Literature
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Because of the wide variety of phenomena associated with the split of two-phase flow at junction, the problem has been approached from two extreme ends. High quality annular or stratified flow and low quality, stratified or bubbly flow are considered separately. Data, phenomena and models are considered for each case.
Protein kinase CK2 subunits alpha and beta were expressed either separately or together in a bacterial expression system (pT7-7/BL21(DE3)) and purified to homogeneity. After mixing the subunits, a CK2 holoenzyme (alpha 2 beta 2) was spontaneously reconstituted, which displays identical features as the native enzyme. T…
Several diffractive optical elements that operate in the infrared are presented. The microrelief structure is either a V-groove or binary lamellar and the features are of the size of one wavelength or below. The applications of these elements are beam deflectors, beamsplitters, beam attenuators, and polarizers.
Abstract Phospham is an iminophosphazene polymer of unusually high thermal stability. We have found that phospham imparts a substantial level of flame retardancy to nylon‐4,6, a high‐melting crystalline engineering thermoplastic. It did not appear to produce degradation of the polyamide in the processing temperature r…
Abstract Daß Mikroorganismen organische Werkstoffe angreifen, ist seit langem bekannt. Daß sie auch mineralische, metallische und synthetisch‐organische Werkstoffe angreifen können, ist eine relativ neue Erkenntnis. Es wird geschätzt, daß mindestens 20% aller Korrosionsschäden an Metallen und Baustoffen mikrobiell bee…
An inversion in the cholesteric phase has been found to occur with change in temperature. Additionally, the material under investigation was found to exhibit unusual ferroelectric properties on cooling from the chiral nematic phase. We report the synthesis and physical properties, including pitch and polarization data…
In this study, compositional dependence of age hardening characteristics and high temperature tensile properties is investigated in binary magnesium alloys with 5, 10, 15 and 20 mass%Gd or Dy. Considerable age hardening is recognized in alloys with higher content of Gd or Dy. In case of equal rare earth metal contents…
31 P MAS and 11 B NMR have been used to investigate the structure of glass samples with the chemical composition (1-x)NaPO 3 -xNa 2 B 4 O 7 . The 31 P resonance spectra present several Gaussian lines which are due to different environments around the PO 4 units. In addition to the phosphate units occuring for R≥1 in t…
The electrochemistry of polyaniline (PANI) films deposited on platinum microelectrodes has been studied in a wide pH region, at constant ionic strength. Cyclic voltammograms, recorded at a sweep rate of 100 V s–1 indicate that the films remain electroactive at pH values as high as 9 provided that the films are only sw…
The decrease in efficiency of ZnS:Ag,Al phosphor powders under high cathode-ray excitation densities has been investigated in a wide range of Ag concentrations (18–1560 ppm) with the Al/Ag ratio fixed at 1.5. Two distinct regions have been observed in this saturation behavior. For low Ag concentrations up to some 100…
Abstract To produce reaction products with 100% chemical selectivity, and to attain much higher turnover rates and number of turnovers, the development of new methods of catalyst preparation are necessary. Precise control of particle size, the separation between catalyst particles and their superior chemical and therm…
Modeling of sacrificial layer etching can be done by combining the diffusion rates of etchants in solution and the chemical reaction rate. Steady‐state diffusion is estimated for diffusion coefficients in water on the range of as observed from an independent experiment. Likewise, the chemical reaction rates (or initia…
Two refined crystal structures of aspartate aminotransferase from E. coli are reported. The wild type enzyme is in the pyridoxal phosphate (PLP) form and its structure has been determined to 2.4 A resolution, refined to an R-factor of 23.2%. The structure of the Arg292Asp mutant has been determined at 2.8 A resolution…
Effects of flame treatment on polyethylene (PE) surfaces have been studied using contact-angle measurements, attenuated total reflection infrared spectroscopy (ATR-IR), X-ray photoelectron spectroscopy (XPS), and an adhesion test. A significantly higher level of surface oxidation was induced by flame treatment on PE t…
The coefficient of friction of 14 prescribable bath emollients was determined using porcine skin attached to a loaded plunger placed through a bearing in a friction-measuring carriage, held above a reciprocating table powered by a DC motor. The carriage was mounted in low-friction rollers, and restrained by a piezo-el…
Zone refining has been tried on high-purity aluminum produced by a combination of the three-layer electrolytic refining process and the segregation process. The cropping procedure was effective in increasing the efficiency of zone refining. The highest residual resistance ratio R(300 K)/R(4.2 K) obtained was about 900…
Photophysical properties have been measured for five merocyanine dyes having (i) different alkyl substituents on the thiobarbiturate subunit [i.e. ethyl (butyl Merocyanine 540), or hexyl], (ii) the sulfonate group replaced with a methyl group, or (iii) the benzoxazole residue replaced with 1,2-naphthoxazole, and for o…
The effects of plasticizer, polyethylene glycol (PEG-600), on the sucrose permeability, void volume and morphology of cellulose acetate free films were investigated. The sucrose permeability of cellulose acetate free films was found to decrease with increasing PEG-600 to a minimum and increase dramatically when they w…
The order of reactivity of perfluorinated dienes towards methanol is 3 > 21 and the process is activated by release of angle strain. The diene 1 is hydrolysed to give perfluorotetramethyl-furan and the corresponding thiophene, is obtained by an analogous process using K2S. Hydrolysis of compounds 2 and 3 yields diketo…
Titanium alloys absorb large amounts of hydrogen and it is desorbed in vacuum at elevated temperatures. This paper describes equiaxed grain refinement and the improvement of mechanical properties of titanium alloys utilizing this phenomenon. Particular attention has been paid to the control of three different types of…