Materials Literature
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We present simulations of flux-gradient-driven superconducting vortices interacting with strong columnar pinning defects as an external field $H(t)$ is quasi-statically swept from zero through a matching field $B_ϕ$. We analyze several measurable quantities, including the local flux density $ B(x,y,H(t))$, magnetizati…
In the theory of electric strength, usually referred to as free-volume theory, breakdown is initiated by free electrons accelerated by electric field in the largest of the holes present in the amorphous phase of all polymers. In contrast to previous publications, the breakdown is treated as the final stage of the disp…
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” opt…
Radially and azimuthally oriented liquid crystal (LC) alignment patterns, which are hard to achieve by conventional LC alignment techniques, have been realized by exposure of polyimide surfaces to linearly polarized ultraviolet radiation. These surfaces can be used to realize some special LC configurations which are u…
Copper deposition based on a newly synthesized metalorganic compound shows promise for reproducible deposition which has been a major problem. The deposition can be carried out without adverse effect on the film qualities at the bubbler temperature of 65 °C. Preliminary deposition results reveal that the resistivity i…
Temperature and compositional dependences of electrical conductivity in lead - iron glasses are reported. The experimental results are analysed in the light of existing theories. It has been observed that the electrical conduction in these glass compositions at high temperatures is best described by Mott's phonon-assi…
Mesoscopic ordering processes have been found in binary polymer mixtures where only one polymer component was selectively cross-linked by irradiation with ultraviolet light. Depending upon the competitions between the reaction and the phase separation, the mixture can be destabilized and exhibits a wide range of mesos…
The amplitude $\ensuremath{\Delta}\ensuremath{\rho}(T,H)/\ensuremath{\rho}$ and temperature ${T}_{M}$, where the colossal magnetoresistance (CMR) response of ${L}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}$ manganites are maximum, are found to be controlled by the radius of the lanthanide $({L}^{3+})$ which…
An extension to chiral phases of a model derived previously to interpret orientational properties in liquid crystal solvents of molecules with arbitrary shape leads, quite naturally, to the definition of a traceless chirality tensor, useful for predicting the structures of twisted nematics induced by chiral solutes. T…
New biocomposites with dynamically active properties were synthesized containing the conducting electroactive polymer, polypyrrole, dextran sulphate and a range of proteins. These composites have a hydrophilic matrix with a high water content and confer on the conducting polymer several properties useful in the design…
The thermomechanical properties of a thin film of shape memory polymer of polyurethane series were investigated experimentally. The results were summarized as follows: (1) Modulus of elasticity and yield stress are high below glass transition temperature T<SUB>g</SUB> and low above T<SUB>g</SUB>. The value of loss tan…
One-photon laser excitation of Xe(6s[3/2]2) and Kr(5s[3/2]2) atoms that were generated in a discharge-flow reactor was used to study the collisional relaxation of the Kr(5p′[3/2]1, [3/2]2, and [1/2]1), the Xe(7p[3/2]2, [3/2]1, [5/2]2, and [5/2]3), and the Xe(6p′[3/2]1, [3/2]2, and [1/2]1) states in He and Ar. Both cw…
We present results from an extensive lattice Monte Carlo study of the adsorption and desorption of homopolymer chains from semidilute solution onto a solid/liquid interface. We have studied in detail the growth, equilibrium structure and dynamics, and rinsing of layers of homopolymers adsorbed from solution. For solut…
The SAC(symmetry adapted cluster)/SAC-CI method is applied to the calculations of the ground, excited, and ionized states of the free base porphin. The electronic spectrum of porphin is well reproduced and new assignments for the B (Soret), N, L, and M bands are proposed. The present result shows that the four-orbital…
The polybutadiene (PB) content and its microstructure in different grades of high impact polystyrene (HIPS) has been studied by various spectroscopic techniques. PB is characterized by deformation bands in FTIR spectroscopy at 994, 967, 912, and 729 cm−1. FT-Raman was used for higher constant resolution over the range…
1,4-Bis(2,3-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, bis(2,3-dicarboxyphenoxy)sulfide dianhydride, bis(3,4-dicarboxyphenoxy)sulfide dianhydride, and 2,3,3′,4′-tetracarboxy diphenyl sulfide dianhydride were synthesized from 3-chlorophthalic anhydride and 4-chlorophthalic a…
Abstract The self‐assembly of alkaline folates in isotropic water solutions, with or without added salts, has been investigated by small‐angle neutron‐scattering, circular‐dichroism, and NMR techniques. The assembled species are chiral, cylindrical aggregates of finite length, composed of stacked tetramers; each tetra…
The low-temperature properties of block copolyetheresters with hard segments of poly(alkylene p,p′-bibenzoate) and soft segments of poly(tetramethylene ether) were investigated by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). In the temperature range of −100 to 60°C, two transition tem…
Ionizing radiation induces various changes in the molecular structure of elastomers; consequently, the macroscopic properties of the irradiated elastomers will be modified. The newly formed products and the alteration of the initial chemical structure are the result of free-radical reactions which provide the crosslin…
This work studies the bulk and nonisothermic polymerization of styrene (S) using mixtures of mono- and bifunctional initiators. The effects on polymerization rate and on molecular weight averages after changes in the global initiator concentration and in the nature of the initiator mixtures were experimentally and the…