Materials Literature
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A study on the semi-volatile aromatic hydrocarbon emissions from the pyrolysis/combustion of poly(styrene) (PS), poly(ethylene) (PE) and PVC particles was conducted. Dispersions (aerosols) or batches (fixed beds) of the above types of polymer particles, 90-300 μm in diameter, were burned in bench-scale, drop-tube or m…
Polyolefins are a very important class of commercial polymers in the world today and are used in a wide range of applications. Despite their versatility, they suffer from certain drawbacks that exert a limiting influence on their range of applications. They are nonpolar and therefore exhibit poor hygroscopicity, print…
We report measurements on the isothermal relaxation dynamics of the electro-optic coefficient of electric field poled polymeric films. The studied copolymer is a side-chain Disperse Red 1/poly–methyl–metacrylate combination. The isothermal relaxation is shown to follow a Kohlrausch–Williams–Watts stretched exponential…
Abstract Product‐selectivity in the electroreduction of p ‐methylbenzaldehyde and benzoic acid under ultrasonic irradiation are examined theoretically and experimentally on the basis of mass transport phenomena in lhe electrode interface. As a result, it was suggested that the selectivity is controlled by mass transfe…
Polymer-polymer blends are the most exciting and promising area for generating novel materials with improved properties in relatively short development times [11. Among different types of blends one can distinguish two important categories. The first category involves homogeneous polymer alloys, which exhibit properti…
The reciprocal lattices of fibrous and lamellar textured polycrystalline thin films are analyzed on the basis of the number of distinct angles made between planes of {hkl} families with the texture axis. Tables of the maximum possible number of such distinct angles between any given direction/plane and all faces of a…
An investigation was carried out to determine whether isooctane and ethanol behave like sunflower oil as fatty simulants for overall and for specific migration from PVC containing aromatic plasticizers (bis-2-ethylhexyl phthalate and tris-2-ethylhexyl trimellitate). In these films, the partition coefficients of migran…
Lamellar twinning of opposite enantiomers explains why the enantiomeric composition of a supersaturated solution oscillates during resolution by preferential crystallization of the bicyclic lactam (1; see diagram on the right).
The metE gene, encoding S-adenosylmethionine synthetase (EC 2.5.1.6) from Bacillus subtilis, was cloned in two steps by normal and inverse PCR. The DNA sequence of the metE gene contains an open reading frame which encodes a 400-amino-acid sequence that is homologous to other known S-adenosylmethionine synthetases. Th…
Electron-irradiation-induced amorphization in coesite was observed in situ as a function of temperature (15--750 K) at an incident electron energy of 1.0 MeV by transmission electron microscopy. Amorphization induced by ion-beam irradiation (1.5 MeV ${\mathrm{Kr}}^{+}$) in coesite was studied in situ as a function of…
Abstract Standard 10-d whole-sediment toxicity test methods have recently been developed by the U.S. Environmental Protection Agency (EPA) for the amphipod Hyalella azteca and the midge Chironomus tentans. An interlaboratory evaluation of method precision was performed using a group of seven to 10 laboratories, repres…
Abstract The complexes [Ln(Ph 2 pz) 3 (DME) 2 ] and [Ln( t Bu 2 pz) 3 (DME)] (Ln = La, Nd, Er; Ph 2 pzH = 3,5‐diphenylpyrazole; t Bu 2 pzH = 3,5‐di‐ tert ‐butylpyrazole; DME = 1,2‐dimethoxyethane) have been prepared by reaction of the lanthanoid metal with bis(pentafluorophenyl)mercury and the pyrazole in DME. The mol…
The origin of the difference in the switching properties of ferroelectric thin films and bulk ferroelectrics is discussed. The ideas of the size effects which may account for this difference are critically reviewed. It is shown that the two often used models (the Janovec-Kay-Dunn surface nucleation size effect and the…
Three genes encoding enzymes involved in the biosynthesis of pyrimidines have been found to constitute an operon in Lactococcus lactis. Two of the genes are the well-known pyr genes pyrDb and pyrF, encoding dihydroorotate dehydrogenase and orotidine monophosphate decarboxylase, respectively. The third gene encodes a p…
Two crystalline compounds based on the Zn-tetra (4-carboxyphenyl)porphyrin building block have been prepared and structurally analysed by x-ray diffraction in order to ellucidate the characteristic supramolecular aggregation modes of this functionalized metalloporphyrin moiety. Crystals of the 1:1 complex with sec-phe…
Other| August 01, 1996 Crystal chemistry and IR spectroscopy of Cl- and SO 4 -bearing cancrinite-like minerals P. Ballirano; P. Ballirano Universita di Roma "La Sapienza", Dipartimento di Scienze della Terra, Rome, Italy Search for other works by this author on: GSW Google Scholar A. Maras; A. Maras Search for other w…
Coverage-dependent adsorption studies of benzoic acid on a Cu(110) single crystal surface resulted in a sequence of novel, large periodicity structures containing differently oriented benzoate species, as shown by LEED, STM and FTIR. At low coverage, only flat-lying benzoate species are present and faceting of step ed…
Many of the physical pictures used to rationalize the phenomenology of glassy dynamics rest upon a consideration of spatial fluctuations in the relaxation kinetics of the glass-forming liquid. We examine the wide ranging consequences which flow from assuming the existence of transient kinetic inhomogeneities. These co…
We have fabricated perovskite superlattices consisting of two ferromagnetic metallic oxides: ${\mathrm{La}}_{0.67}$${\mathrm{Ca}}_{0.33}$Mn${\mathrm{O}}_{3}$ (LCMO) and SrRu${\mathrm{O}}_{3}$ (SRO). We have investigated the magnetotransport and magnetic properties of a series of samples, in which the layer thickness o…
Macromolecular X-ray crystallography underpins the vigorous field of structural molecular biology having yielded many protein, nucleic acid and virus structures in fine detail. The understanding of the recognition by these macromolecules, as receptors, of their cognate ligands involves the detailed study of the struct…