Materials Literature
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This study was focused on the conformational characterization of Bombyx mori silk fibroin in film, fiber and powder form by means of Fourier transform Raman spectroscopy. Native and regenerated silk fibroin films prepared by casting dilute silk fibroin solutions (<1%, w/v) display characteristic conformationally sensi…
Transport properties of ${\mathrm{La}}_{0.75}{\mathrm{Ca}}_{0.25}{\mathrm{Mn}}_{1\ensuremath{-}x}{\mathrm{Fe}}_{x}{\mathrm{O}}_{3+y}$ ceramics are examined for ``$x$'' values from 0 to 0.05. Dramatic changes are observed in the resistivity and its temperature dependence as ``$x$'' increases above about 0.04. Temperatu…
Crack deflection and the subsequent growth of delamination cracks can be a potent source of energy dissipation during the fracture of layered ceramics. In this study, multilayered ceramics that consist of silicon nitride (Si 3 N 4 ) layers separated by boron nitride/silicon nitride (BN/Si 3 N 4 ) interphases have been…
Quantum ferroelectric and ferroelectric relaxor behavior has been found in $({\mathrm{Sr}}_{1\ensuremath{-}1.5x}{\mathrm{Bi}}_{x}){\mathrm{TiO}}_{3}.$ For $x<~0.0267,$ the quantum ferroelectric relationship ${T}_{{\ensuremath{\varepsilon}}_{m}}\ensuremath{\propto}(x\ensuremath{-}{x}_{c}{)}^{1/2}$ holds with ${x}_{c…
This paper describes an on-line PD (partial discharge) detection technique applicable to power cables. The method can be applied to both wire screen and solid shielded cables. In wire screen shielded cables, PD components with frequencies <100 MHz can be detected at distances over 150 m from the source, PD activity wi…
We report a systematic FTIR study of the perturbation of water “sorbed” into the polymers PET and PVC as a function of crystallinity (PET) or plasticizer content (PVC). Band shapes of the composite ν(OH) band of H 2 O obtained by the ATR technique have been fitted to individual components,corresponding to those recent…
Electrical conduction mechanisms for Pt/(Ba0.5Sr0.5)TiO3 (BST)/Pt, IrO2/BST/IrO2, and Pt/BST/IrO2 capacitors were studied. The Pt/BST/Pt capacitor shows a Schottky emission behavior with interface potential barrier heights of about 1.5–1.6 eV. The barrier height is largely determined by the surface electron trap state…
ADVERTISEMENT RETURN TO ISSUEPREVArticleFirst-Principles Quantum Chemical Studies of PorphyrinsAbhik GhoshView Author Information Department of Chemistry, Faculty of Science, University of Tromsø, N-9037 Tromsø, Norway, and San Diego Supercomputer Center, 10100 Hopkins Drive, La Jolla, California 92093 Cite this: Acc.…
The local electronic structure of a material can be determined from the energy-loss spectrum of a swift electron beam scattered through it. When the electron beam is focused down to the width of an atomic column, the electronic density of states (DOS) at an interface, grain boundary, or impurity site can be decomposed…
The temperature dependence of the dielectric constant under different frequencies is measured and analyzed for two different relaxor ferroelectrics, the solid solution ceramics of lead magnesium niobate and lead zinc niobate, respectively. Compared with the experimental results, the disadvantage of simulated results f…
Thermomonospora fusca E4 is an unusual 90.4-kDa endocellulase comprised of a catalytic domain (CD), an internal family IIIc cellulose binding domain (CBD), a fibronectinlike domain, and a family II CBD. Constructs containing the CD alone (E4-51), the CD plus the family IIIc CBD (E4-68), and the CD plus the fibronectin…
Muscles convert chemical energy to mechanical energy plus heat at constant temperature. The search for artificial muscles that do the same is described, beginning with polymer gels—which were restricted to slow movements and had high energy consumption—and ending with the bilayer devices that have been constructed fro…
A series of glass ceramics have been synthesized to produce bulk materials with nanometer‐sized barium titanate (BaTiO 3 ) crystals grown in a residue glass matrix. Structure‐property relations have been made to determine the size distribution and the dielectric temperature dependence of the ceramics. Through dielectr…
This paper describes the first observation of localized electropolymerization of pyrrole and aniline on highly oriented pyrolytic graphite (HOPG) substrates under atomic force microscopy (AFM) tip−sample interactions. A scanning or oscillating AFM tip, providing the horizontal scratching force and the vertical tapping…
The bond-order potential for hcp Ti has been constructed in the framework of a tight-binding description of the binding energy. In this scheme the energy consists of two parts: the bond part that comprises the d-electron contribution to bonding, and a pairwise part. Both parts contain fitting parameters but are treate…
HVDC cables start playing a more and more important role in interconnecting national grids. This paper deals with the calculation of electric fields in HVDC cables. The calculation of fields in an HVDC cable is far more complex than the equivalent case in HV ac cables. This is due to the fact that the conductivity of…
The 100th anniversary of The American Ceramic Society corresponds approximately with the 100th anniversary of what might be considered the start of the age of glass science, i.e., the publication, in Germany, in 1886, of the catalog of Schott und Genossen, containing 44 optical glass compositions. The American Ceramic…
We present a theoretical study of in-plane magnetization reversal for vicinal ultrathin films using a one-dimensional micromagnetic model with nearest-neighbor exchange, four-fold anisotropy at all sites, and two-fold anisotropy at step edges. A detailed "phase diagram" is presented that catalogs the possible shapes o…
An attempt is made to simulate the homoepitaxial growth of a Si(111) surface by the kinetic Monte Carlo method in which the standard Solid-on-Solid model and the planar model of the (7x7) surface reconstruction are used in combination. By taking account of surface reconstructions as well as atomic deposition and migra…
We present a model for the luminescence spectrum of silicon nanoclusters. We propose that the major contribution to luminescence is from radiative recombination of confined excitons (quantum confinement). Utilizing the effective mass approximation we consider the variation in oscillator strength with cluster size and…