Materials Literature
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Dielectric measurements of an epoxy resin, N, N-diglycidyl-4-glycidyloxyaniline, have been carried out in the supercooled and glassy phase over a broad frequency range (10 2 -6 ×10 9 Hz). The measurements reveal electrical transport due to ionic impurities as well as three different dipolar relaxations - in addition t…
A series of Eu 3+ -doped silica sol−gels are prepared under various conditions: (1) pH values of the sols are controlled at 3.0, 5.5, and 7.5; (2) the counterions of dopants are selected from acetate, chloride, and nitrate of europium (III) compounds; (3) two chelating agents, namely ethylenediaminetetraacetic acid (E…
A model based on the existence of two different competing local structures in water is described. It is shown that it can explain the transition between fragile and strong behaviour that supercooled water undergoes at around 220 K. The high-temperature behaviour is similar to that observed in standard fragile glass fo…
Depletion forces in colloidal systems are known to be entirely attractive, as long as the background of macromolecules is small enough that an ideal gas approach is valid. At higher densities, however, structural correlation effects of the macromolecules which lead to additional repulsive parts in the depletion intera…
The second-order nonlinear susceptibility of some novel 7,7-diarylnorbornane compounds in chloroform solution has been measured by EFISH at a fundamental wavelength λ = 1064 nm. Values of β z for the cofacial apical molecules ( 1 − 6 ) are enhanced in comparison to those reported for the uncoupled aryl rings. Highest…
Succinyl-CoA synthetase (SCS) catalyzes the following reversible reaction via a phosphorylated histidine intermediate (His 246alpha): succinyl-CoA + P(i) + NDP <--> succinate + CoA + NTP (N denotes adenosine or guanosine). To determine the structure of the enzyme with nucleotide bound, crystals of phosphorylated Esche…
The idealized mode-coupling theory (MCT) is applied to colloidal systems interacting via short-range attractive interactions of Yukawa form. At low temperatures, MCT predicts a slowing down of the local dynamics and ergodicity-breaking transitions. The non-ergodicity transitions share many features with the colloidal…
The thermal chemistry of iodomethane, iodoethane, 1-iodopropane, 1-iodobutane, and 2-iodohexane on copper (100), (110), and (111) single-crystal surfaces was characterized in this and previous studies by temperature-programmed desorption (TPD) spectroscopy. The main decomposition pathway available to the methyl surfac…
In the Al-Pd-Ru system, a structurally ordered icosahedral phase has been successfully produced near the composition Al 73 Pd 15 Ru 12 by heat treatment at 1273 K for several hours. The x-ray diffraction patterns of the Al-Pd-Ru i-phase are very sharp, indicating that the i-phase is quite stable and that samples of hi…
As a renewable and native polymeric material, thermoplastic starch is gaining increased acceptance because of resource and environment concerns. This study reports the formulation design of native starch/polyvinyl alcohol (PVAl) compounds; the preparation technology to make them available for thermoplastic processing;…
Linear tetrapyrroles related to phytochrome (1) were prepared in enantiospecific fashion by a new strategy beginning with ring-B,C synthons of type 19 (bis-iododipyrrins). Rings A and D were elaborated by Pd(0)-mediated coupling of 19a with the appropriate alkyne acid or amide derivatives 9 and 20, followed by intramo…
During the last years, many efforts have been devoted to the elimination of alkylphenol ethoxylate surfactants from aqueous systems. In this paper, the sonochemical degradation of aqueous solutions of Triton X-100 was performed at an ultrasonic frequency of 358 kHz and an applied power of 50 W. Analysis of the reactio…
Silk fibroin/chitosan blend films were prepared by the solvent casting method. Miscibility between silk fibroin and chitosan was examined by dynamic mechanical thermal analysis. Structural changes of silk fibroin by the addition of chitosan were investigated by IR spectroscopy. The conformational transition of silk fi…
A new type of carbon nanotube (CNT) (diameter of <100 nm) coated by conducting polypyrrole (PPY) was synthesized by in situ polymerization on CNTs. The structure of the resulting complex nanotubes (CNT-PPY) was characterized by elemental analysis, X-ray photoelectron spectroscopy, Raman spectra, and X-ray diffraction.…
Within the framework of staircase infinitely deep (SIW) potential well model the effect of dielectric constant mismatch between the size-quantized semiconducting wire, coating and surrounding environment on impurity binding energy is considered. Calculations are done in both the absence and presence of magnetic field…
We present a lattice Boltzmann algorithm for liquid crystal hydrodynamics. The coupling between the tensor order parameter and the flow is treated consistently allowing investigation of a wide range of non-Newtonian flow behavior. We present results for the effect of hydrodynamics on defect coalescence; of the appeara…
We present the first ab initio density functional theory study of the oxygen-terminated Cr2O3 (0001) surface within the local spin-density approximation (LSDA). We find that spin plays a critical role for even the most basic properties of Cr2O3 such as the structure and mechanical response of the bulk material. The su…
We propose the non-accelerator non-low-temperature simulator of quantum-field effects which is based on the feeder circuits with the special feedback. By means of it one can study the field models which contain fundamental concepts in the modern field theory but do not exist in nature in a separate form. Besides, seve…
We study the phase behaviour and structure of model colloid-polymer mixtures. By integrating out the degrees of freedom of the non-adsorbing ideal polymer coils, we derive a formal expression for the effective one-component Hamiltonian of the colloids. Using the two-body (Asakura-Oosawa pair potential) approximation t…
The sonochemical degradation of aqueous solutions of azobenzene and related azo dyes (methyl orange, o -methyl red, and p -methyl red) was performed at 500 kHz and 50 W, under air, O 2, or Ar saturation at 288 K. Reaction products and intermediates were identified by HPLC-ES-MS. Total organic carbon (TOC) was also det…