Materials Literature
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Faster workstations with larger memories are making error estimation from full-matrix least-squares refinement a more practicable technique in protein crystallography. Using minimum variance weighting, estimated standard deviations of atomic positions have been calculated for two eye lens proteins from the inverse of…
We present specific-heat and ac-susceptibility measurements providing more evidence that magnetic quantum tunneling occurs in ${\mathrm{Mn}}_{12}$Ac spin clusters. The total anisotropy energy barrier determined by fitting an Arrhenius law to the magnetic relaxation time is underestimated when compared to the specific-…
The internal-friction spectra of a thermoelastic martensitic transformation are usually obtained as a function of temperature with $\mathrm{T\ifmmode \dot{}\else \.{}\fi{}}\ensuremath{\ne}0$ and show three---phase transition, transitory, and intrinsic---contributions. This paper proposes a systematic method to analyze…
We report the results of a computer simulation of the evolution of structure in a two component fluid consisting of a liquid phase and a dispersed colloidal phase subjected to a uniaxial field. Our primary objective is to understand the mechanism and kinetics of coarsening and the emergence of crystallinity. Using an…
Two theories, the high field model (HFM), and variants thereof, and the point defect model (PDM), have been advanced to account for the properties of thin anodic passive films (barrier layers). The HFM states that, under potentiostatic conditions, the electric field strength in a passive film decreases as the film thi…
Electronic and magnetic properties are systematically investigated for doped manganites ${R}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{MnO}}_{3}$ $(R={\mathrm{La}}_{1\ensuremath{-}z}{\mathrm{Nd}}_{z})$ by changing the nominal hole concentration $x$ and the averaged ionic radius of the perovskite $A$ site $(z),$ or t…
This review of metallodendrimers has two main goals: first, to illustrate the various structure types of metallodendrimers, demonstrating their substantial structural diversity, and second, to highlight their applications, either potential or already coming into existence. Applications include metallodendrimers as nan…
The phase transitions from a smectic-$C$ to a tilted hexatic phase are known to form a first-order transition line that terminates in an isolated critical point, beyond which there is supercritical evolution of bond-orientational order without a thermodynamic transition. Recent experiments strongly suggest that smecti…
In this paper, we review a number of the latest developments for the broad family of thermoplastic elastomers (TPEs); these can be seen mainly in the groups of block copolymers and polymer blends, including dynamically vulcanized polyblends. Recently, the synthesis and properties of TPEs derived from triazinedithiols,…
Pillared clay has emerged in recent years as a very good shape-selective solid acid catalyst for various organic chemical transformations. In the present study an attempt has been made to prepare various pillared inter-layered clays (PILC) with inorganic polyoxocations prepared from Al, Zr and mixed Al and Zr salts. P…
In order to simulate the experimental phenomenon of increase of natural frequency to a cantilevered ferromagnetic beam plate in in-plane magnetic fields, a theoretical model for behaving the magnetoelastic interaction is proposed in this paper based on the variational principle of energy functional of the system. It i…
A knowledge of substituent electronic effects is essential to the understanding of relative rates, equilibrium constants, and reactive intermediates of both in vivo and in vitro reactions. At Lebanon Valley College, we have developed an electrochemical experiment that correlates the electronic effects of substituents…
A spectral approach to the theory of partial coherence of nonstationary light [ M. Bertolotti , Pure Appl. Opt.6, 153 (1997)] is applied to the study of spatial coherence properties of nonstationary wave fields on propagation in free space. Three types of nonstationary light sources are considered—a point source, a sp…
The mechanism of strength reduction of sewing threads has been discussed in Part I of this paper. The effect of fabric tightness and certain thread properties like its size, coefficient of yarn-metal friction, twist direction, number of piles, type of fibre and fibre denier on strength reduction has been studied and f…
This work describes the preparation and characterization of anionic collagen composites with rhamsan and vinylidene fluoride-trifluorethylene with improved rheological and dielectric properties without loss of collagen secondary structure with an interaction occurring between both macromolecules of the composites. On…
Abstract Fifteen Swedish and Finnish soil samples from spodic B horizons containing imogolite-type materials were equilibrated with dilute NaCl and HC1 at 8°C. For the NaCl extracts, apparent equilibrium with respect to an AI(OH)3 phase was reached in one to two weeks. Equilibrium with respect to an imogolite-type pha…
We study the nucleation of cholesteric fingers in directional growth when a cholesteric phase of positive dielectric anisotropy grows into its isotropic liquid. The experiment is performed in homeotropic anchoring and in electric field near the coexistence line of unwinding of the cholesteric helix. Four types of fing…
A general overview on Lamellar Double Hydroxides (LDHs) is given, includind discussions about the structure and preparative methods. A tentative development strategy illustrated by examples is suggested.
The second-order nonlinear optical (NLO) properties of some bisdithiophene d8 metal complexes, for example, the donor–acceptor unsymmetrically substituted bisdithiophene nickel(II) complex shown in the Figure, are reported for the first time. The synthesis and characterization of the complexes are described and the re…
The genus Chaetoceros , one of the most important genera of diatoms in the marine plankton, has been investigated from 20 stations in Danish waters during the period 1991–1995. Thirty‐five taxa were identified, 18 of which were brought into culture for further morphological studies. Three taxa are reported for the fir…