Materials Literature
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Whereas plants and animals use the alpha-aminoadipic acid pathway to catabolize lysine, yeast and fungi use the very same pathway to synthesize lysine. These two groups of organisms also possess structurally distinct forms of two enzymes in this pathway, namely lysine-oxoglutarate reductase (lysine-ketoglutarate reduc…
This review addresses a number of aspects of electron energy loss spectroscopy (EELS) for quantitative analysis, including: procedures for the quantification of EELS elemental analysis and mapping with an indication of the accuracies and detection sensitivities; procedures for the extraction of valence band electronic…
Attempts to build up polyanionic networks on the basis of thiocyanatometallates of CuI and AgI led to the synthesis of three new tris(thiocyanato)dimetallates(I) A[M2(SCN)3] with M = Cu, Ag and A = Me3NH and A = [Me2CNMe2]. The crystal structures show distorted tetrahedral [M(SCN)3(NCS)] and [M(SCN)2(NCS)2] building g…
The paper presents the results of a complex investigation into the dynamics of electronic excitations in the CsLiB 6 O 10 crystal (CLBO) by low-temperature luminescence VUV spectroscopy with subnanosecond time resolution under photoexcitation by synchrotron radiation. Strong broad-band low-temperature photoluminescenc…
Abstract The crystal structure of faustite, ZnAl 6 (PO 4 ) 4 (OH) 8 .4H 2 O, was determined using single-crystal data (Mo-Kα X-radiation, CCD area detector, 1624 unique reflections, R 1 = 4.91%, w R 2 = 9.23%), and compared with results of a reinvestigation of the structure of its copper analogue turquoise, CuAl 6 (PO…
Tumchaite, Na 2 (Zr,Sn)Si 4 O 11 ·2H 2 O, is a new species from the Vuoriyarvi alkali-ultrabasic massif, Murmansk Region, Russia, where it occurs as colorless to white tabular monoclinic crystals associated with calcite, dolomite, a mineral of the serpentine group and pyrite in the late dolomitecalcite carbonatites. I…
The crystal structure of tetracalcium trialuminate (Ca 4 Al 6 O 13 ), synthesized at 1250 °C and 2.5 GPa, has been determined from single-crystal X-ray data by direct methods [space group Pcan, Z = 8, a = 5.3002(2) Å, b = 17.7610(5), c = 21.0887(9) Å] and refined to R1 = 6.42%. The unit cell parameters of Ca 4 Al 6 O…
We present a model for alloys of compound semiconductors by introducing a one-dimensional binary random system where impurities are placed in one sublattice while host atoms lie on the other sublattice. The source of disorder is the stochastic fluctuation of the impurity energy from site to site. Although the system i…
In this paper, the synthesis, photo-reaction and photo-induced liquid crystal alignment of a polyimide with a pendant cinnamate group are reported. The polyimide was synthesized by the thermal imidization of the polyamic acid derived from 4,4'-(hexafluoro-isopropylidene)diphthalic anhydride and hydroxydiaminopropane,…
The micromagnetic properties of multilayered MnBi/Al films have been investigated and compared to pure MnBi thin films. Pure MnBi films reveal an anomalous increase of the high temperature coercivity, which has been explained on the basis of a hybrid domain wall pinning model. The multilayer-type preparation of MnBi/A…
We report a novel method of imaging micropatterned self-assembled monolayers (SAMs) using adsorbed films of thermotropic (smectic or nematic) mesophase which can then be studied by optical microscopy. Three alkylthiols, functionalized with CH3, OH and COOH groups, were used in various combinations to form patterned SA…
The microfibrillar morphological structure of aliphatic polyamide fibers has been consistently presented by the three phase microfibrillar model proposed by Prevoršek and not by the two phase microfibrillar model proposed by Peterlin. A widely spread opinion is that the 3-phase or “Swiss-cheese” model is applicable in…
Cellulose was dissolved in a solvent mixture containing N-methylmorpholine-N-oxide (NMMNO), diethylenetriamine (DETA) and water. The weight-average molar masses Mw, radii of gyration RG, and second virial coefficients A2 of 9 different cellulose samples were determined by means of static light scattering (SLS) at room…
A new polyalcohol is prepared by reduction of the perfectly alternating ethylene−carbon monoxide copolymer. The low melting temperature of this atactic material (137 °C) is attributed to the 1,4-arrangement of the hydroxyl side groups. The different orientations of these slightly bulky groups with respect to the molec…
Abstract Siliconized epoxy‐matrix systems have been developed by an interpenetrating mechanism using epoxy resins GY 250 and LY 556 (Ciba‐Geigy) and hydroxyl terminated polydimethylsiloxane with γ‐aminopropyltriethoxysilane as crosslinker in the presence of dibutyltindilaurate catalyst. Aliphatic amine (HY 951, Ciba‐G…
Abstract This paper examines the ion-exchange properties of synthetic zeolite Na-P c , which was produced from perlite-waste fines and has a SiO 2 :Al 2 O 3 ratio of 4.45:1 and a cation-exchange capacity (CEC) of 3.95 meq g −1 . Although equilibrium is attained rapidly for all three metals, exchange is incomplete, wit…
Various issues associated with the design and mechanical evaluation of joints of ceramic matrix composites are discussed. The specific case of an affordable, robust ceramic joining technology (ARCJoinT) to join silicon carbide (CG-Nicalon™) fiber-reinforced-chemically vapor infiltrated (CVI) silicon carbide matrix com…
Oxide scale that mainly consists of spinel-type metal oxides is formed on stainless steels when they are heated up during the manufacturing cycle. The removal of the oxide scale and chromium depleted subscale by pickling is one of the most important processes during the production. Electrolytic pickling in neutral sod…
Spectral studies of the cubic spinel ferrites Zn1—xCuxCr0.8Fe1.2O4, 0 ≤ x ≤ 1 are carried out at room temperature by X-ray, Mössbauer and IR spectra. The deduced X-ray parameters have been studied as functions of x. The average and true lattice parameters (ā and a0), the theoretical and bulk densities (DX and D), and…
A simplified model for studying the behavior of plain woven fabrics is presented. The model consists of two plate elements including a thin layer of matrix between them. Hierarchic shape functions are employed to characterize the initially curved profile of the yarns and the displacements of the plate elements. The pl…