Materials Literature
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Space charge is believed to play an important role in ac electrical ageing of polymeric insulation, particularly where electrical treeing is the dominant cause of premature failure. The majority of work to date has been on the space charge characteristics under dc electric stresses, whereas work on the dynamics and th…
Abstract. In organic agriculture, where K may be a limited resource, reliable tools are important in the assessment of K availability in the soil in order to avoid K deficiency. We investigated the effect of four organic farming systems on the exchangeable K in the plough layer of a six‐course crop rotation from 1994…
Yeast NAD(+)-specific isocitrate dehydrogenase (IDH) is an octamer containing two types of homologous subunits. Ligand-binding analyses were conducted to examine effects of residue changes in putative catalytic and regulatory isocitrate-binding sites respectively contained in IDH2 and IDH1 subunits. Replacement of hom…
The surface morphology evolution of thin poly(styrene- block -ethylene/butylenes- block -styrene) (SEBS) triblock copolymer films as a function of the copolymer concentration was investigated by means of dynamic mode atomic force microscopy. At a relatively low copolymer concentration (0.025% w/v), the periodically or…
The role of polydimethylsiloxane (PDMS) as a compatibilizer of polyimide/silica hybrid composites was investigated. Introduction of PDMS into a polyimide matrix retards the phase separation of hybrid composites and also prevents the formation of high-molecular-weight silicate. PDMS interacts with silica because of the…
The folate derivative 5-formyltetrahydrofolate (folinic acid; 5-CHO-THF) was discovered over 40 years ago, but its role in metabolism remains poorly understood. Only one enzyme is known that utilizes 5-CHO-THF as a substrate: 5,10-methenyltetrahydrofolate synthetase (MTHFS). A BLAST search of the yeast genome using th…
The mechanisms controlling normal and exaggerated grain growth in lead magnesium niobate–lead titanate (PMN–PT) ceramics have been investigated by varying the PbO‐based liquid‐phase volume fraction from 0.03 to 0.6 and sintering temperature from 900° to 1100°C. There is a transition in matrix grain growth rate and mat…
Galactose mutarotase plays a key role in normal galactose metabolism by catalyzing the interconversion of beta-D-galactose and alpha-D-galactose. Here we describe the three-dimensional architecture of galactose mutarotase from Lactococcus lactis determined to 1.9-A resolution. Each subunit of the dimeric enzyme displa…
The enhanced transmittance matrix approach developed by Moharam et al. [J. Opt. Soc. Am. A 12, 1077 (1995)] is reformulated in a concise and illuminating form in terms of scattering (reflection and transmission) matrices directly. Two equivalent recursive formulations, corresponding to their full- and partial-solution…
Boiling water reactor (BWR) fuel at 56 to 61 GWd/tonne U was pulse irradiated in the Nuclear Safety Research Reactor (NSRR) to investigate fuel behavior under cold startup reactivity-initiated accident conditions. Current Japanese 8 × 8 type Step II BWR fuel from Fukushima Daini Unit 2 was refabricated to short segmen…
Hyperbranched polymers generated from the polymerization of AB 2 -type monomers and trifunctional cores with various reactivities were examined by means of the kinetic theory. The average molecular weight, polydispersity, degree of branching, and structural units of the hyperbranched polymers, which all changed with t…
The nature of oxide phases at metal–oxide interfaces, i.e. of oxide layers in the proximity of a metal surface, is assessed by critically examining the available data in the literature. The data reveal a trend towards the formation of reduced oxide phases with lower oxidation states in the vicinity of the interface wi…
Single-crystal X-ray structure determinations of the complex between the minor-groove binder distamycin and d(GGCCAATTGG) reveal two 1 : 1 binding modes which differ in the orientation of the drug molecule in the minor groove. The two crystals were grown from different crystallization conditions and found to diffract…
Abstract Poly(vinyl chloride) (PVC)–clay nanocomposites were prepared by melt blending using a sodium montmorillonite clay. The nanocomposites were characterized by X‐ray diffraction and transmission electron microscopy techniques. The best description of these materials is as mixed immiscible‐intercalated nanocomposi…
Non-symmetric liquid crystal dimers consist of two different mesogenic units linked through a polymethylene flexible spacer. Our previous studies have shown that dimers containing a cholesteryl moiety as one of the mesogenic groups and a Schiff's base unit as the second, exhibit a rich polymorphism and that several ty…
Proteins of silk fibers are characterized by reiterations of amino acid repeats. Physical properties of the fiber are determined by the amino acid composition, the complexity of repetitive units, and arrangement of these units into higher order arrays. Except for very short motifs of 6-10 residues, the length of repet…
[structure: see text] A versatile stepwise synthetic approach to cofacial bis-porphyrin species with calix[4]arene spacers has been designed. The three examples described demonstrate that the method allows selection, in a tailor-made fashion, of the calix[4]arene conformation, the type of functionalization of the cali…
We show that recent claims of experimental verification of a negative index of refraction in metallic metamaterials, "left-handed" microwave frequencies, are questionable. At these frequencies the imaginary part of the dielectric permittivity is significant or even dominates its real part, and hence the effective medi…
The structure of a new iodate, (LiFe 1/3 )(IO 3 ) 2 , has been determined. The new compound has a hexagonal structure with the lattice parameters a =5.4632(2) Å, c =5.0895(6) Å, Z =1. The density is 4.70 g cm −3 . Rietveld refinement confirms that the compound has a space group of P 6 3 (173). Fe and Li atoms randomly…
The corrosion behaviour of mild steel in 2M hydrochloric acid solution containing various concentrations of condensation products formed from glutaraldehyde + glycine (CP1) and glutaraldehyde + methionine (CP2) has been investigated using weight loss measurement and galvanostatic polarization technique. The percentage…