Materials Literature
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Electrical properties of semiconducting ZnO( n )‐CuO( p ) ceramic composites with varying composition were investigated. The electrical conductivity increased with increasing CuO volume fraction between 1 to 95 mol%. Impedance response showed three semicircles, indicating three resistive elements contributing to the t…
Supramolecular hydrogen-bonded networks have been prepared by self-assembly of a chiral bifunctional H-bond acceptor and achiral trifunctional H-bond donors. A stilbazole dimer, (R)-1,2-bis{4-\[2-(4-pyridyl)ethenyl]phenoxy}propane (1) has been synthesized for use as a chiral component for cholesteric networks. Compoun…
Symmetric polydisperse (Mw = 23 × 104, Mw/Mn = 2.84) and monodisperse (Mw = 21 × 104, Mw/Mn < 1.05) polystyrene (PS), and asymmetric polydisperse PS/poly(2,6-dimethyl 1,4-phenylene oxide) (PPO) interfaces have been bonded in the vicinity of the glass transition temperature (Tg) of PS. In a lap-shear joint geometry, st…
We report an electrically conducting polyaniline–poly(acrylic acid) blend coatings prepared by mixing the emeraldine base (EB) form of polyaniline (PANI) and poly(acrylic acid) (PAA) aqueous solution. The samples show a moderate electrical conductivity σ. If they are immersed in an HCl aqueous solution, the conductivi…
Abstract Percolation, positive temperature coefficient (PTC), and negative temperature co‐efficient (NTC) in carbon black‐filled HDPE composites, were studied by measuring AC electrical properties. An equivalent single parallel circuit model, which consists of a resistor and a capacitor, was adapted to explain the dis…
We propose a mechanism for $A$-type antiferromagnetism in orthorhombic ${\mathrm{LaMnO}}_{3}$, compatible with the large Jahn-Teller splitting inferred from structural data. Orbital ordering resulting from Jahn-Teller distortions effectively leads to layered ordering (antiferromagnetic in the $c$ axis and ferromagneti…
The magnesium, nickel, copper, zinc and vanadium metalloporphyrins from octaethylporphyrin, etioporphyrin I and tetraphenylporphyrin were characterized using electrospray ionization mass spectrometry (ESI-MS). The ion abundance of each of the porphyrins present in binary mixtures was monitored as a function of the por…
In order to evaluate the quantitative cavitation-erosion resistance of materials, a pressure-detector-installed specimen was developed, which can measure both the impact load produced by cavitation bubble collapse and the volume loss simultaneously. Test specimens (pressure-detection rod) used were nine kinds of metal…
The method of ab initio molecular dynamics, based on finite temperature density functional theory, is used to simulate laser heating of graphite. We find that a sufficiently high concentration of excited electrons dramatically weakens the covalent bond. As a result the system undergoes an ultrafast melting transition…
The stepwise synthesis and characterization of a family of selectively metalated 1,2-bis[5-(2,3,7,8,12,13,17,18-octaethylporphyrinyl)]ethenes is described. These compounds are distinct from most of the previously reported bisporphyrin systems which possessed rigid linking groups or multiple strapping units, and their…
A theoretical framework for the temporal behavior of photoinduced anisotropy in liquid-crystalline azobenzene side-chain polyesters is constructed. The domain structure of the material is taken into account and intermolecular interactions are included through a mean-field description. Photoinduced trans↔cis isomerizat…
The electrical and mechanical properties of piezoelectric lead zirconate titanate (PZT) ceramics are strongly influenced by domain‐wall motion, which can be tailored via the substitution of ions within the perovskite structure. Different domain mobilities are achieved by lead and/or oxygen vacancies, according to the…
We have determined the alignment of a Gay-Berne model liquid crystal near a graphite surface using Monte Carlo computer simulations. We find in this regime, where adsorption is dominating with respect to the intermolecular interactions, a discontinuous change in anchoring from planar to normal on going from the first…
We study the onset of sidebranching of growth cells in directional solidification of impure succinonitrile. Care is taken to obtain uniform cell spacing over large distances in order to use this variable as a true control parameter. Two sidebranching modes referring to different crystalline orientations are observed a…
For phase-separated multicomponent polymeric systems, characterization of the interface between the components is particularly challenging. We have observed an optical effect in the infrared that can be used to image the interface specifically. This method yields images of the interfaces based on the interfaces showin…
Phase separation (frequently called coacervation) of poly(lactide) (PLA) and poly(lactide-co-glycolide) (PLGA) is a classical method for drug microencapsulation. Here, attempts have been made to describe this process in the light of thermodynamics. Different PLA/PLGAs were dissolved in either dichloromethane or ethyl…
Mixtures of yttrium acetate hydrate (Y(O 2 CCH 3 ) 3 4H 2 O) and aluminum formate hydrate (Al(O 2 CH) 3 3H 2 O in H 2 O) or yttrium isobutyrate (Y[O 2 CCH(CH 3 ) 2 ] 3 ) and aluminum isobutyrate (Al[O 2 CCH(CH 3 ) 2 ] 3 ) in tetrahydrofuran were used as precursors to process yttrium aluminum garnet (YAG, Al 5 Y 3 O 12…
Collagen fibrils in ligaments and tendons are highly organized into parallel arrays which influence interstitial fluid transport. Finite element (FE) models were developed analogous to the fibrillar arrays in ligaments and tendons to investigate interstitial fluid flow and tissue permeability as a function of interfib…
ABSTRACT A device to objectively measure the melt/flow behavior of cheeses at different temperatures was built consisting of a temperature‐controlled heater, an LVDT (linear variable differential transformer), and a personal computer with a data acquisition system. This device, named UW Meltmeter, operates in the lubr…
In this paper we bring together and extend two recent developments in phase-field models, namely, a phase-field model of a multiphase system [I. Steinbach et al., Physica D 94, 135 (1996)] and the extension of the Cahn-Hoffman \ensuremath{\xi}-vector theory of anisotropic sharp interfaces to phase-field models [A. A.…