Materials Literature
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The strengths of ceramic fibers and whiskers have been observed to increase with decreasing fiber diameter and length. Typically, both surface flaws and volume flaws exist in ceramic fibers and whiskers, which makes it impossible to characterize the strength dependence of both the diameter and the length with a single…
An electron acceptor moiety based on the 4,5-dinitro-1,8-naphthalenedicarboximide system has been prepared and used as the basis for synthesis of a porphyrin−imide dyad (P−NIm) and a carotenoid−porphyrin−imide triad molecule (C−P−NIm). Excitation of the porphyrin moiety in either compound with visible light leads to r…
The effect of repeated radiative energy transfer on the observed excited-state lifetime τobs of a luminescent species in a solid is studied by Monte Carlo simulations. Increasing the sample path length, the reabsorption coefficient, or the luminescence quantum yield significantly lengthens τobs relative to its intrins…
Summary In semi‐arid tropics soil hardening may reduce both water infiltrability and biological activity, thus inducing the development of large almost bare areas. A sandy‐loam soil with contrasting loose and underlying hard horizons was studied in the southern plain of the Chad basin. The fabrics of these horizons we…
The transaminase activity of two new semisynthetic RNase-S proteins incorporating a pyridoxamine moiety at the active site has been evaluated. A chemically competent derivative of pyridoxamine phosphate was incorporated into the C-peptide fragments of these non-covalent protein complexes in the form of an unnatural co…
Bulk samples of nanocrystalline Ni were produced by severe plastic deformation consolidation of ball-milled powders. The processed samples are characterized by reduced values of saturation magnetization and Curie temperature. Relying on transmission electron microscopy and X-ray data, an assumption has been made to ex…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTRemarkable Heteroatom Dependence of the Spin Multiplicity in the Ground State of 9,9'-(m-Phenylene)dixanthyl and -dithioxanthyl DiradicalsKeiji Okada, Takaaki Imakura, Masaji Oda, Atsushi Kajiwara, Mikiharu Kamachi, and Masakazu YamaguchiView Author Information Departm…
An organic nonlinear optical crystal, 5-nitro-2-thiophenecarboxaldehyde-4-methylphenylhydrazone (NTMPH), has been prepared and investigated with regard to polymorphism, growth, and characterization of the structural and physical properties. Recrystallization of NTMPH in various solvents under different conditions show…
Other| June 01, 1997 Incorporation of rare earth elements in titanite; stabilization of the A2/a dimorph by creation of antiphase boundaries John M. Hughes; John M. Hughes Miami University, Department of Geology, Oxford, OH, United States Search for other works by this author on: GSW Google Scholar Erich S. Bloodaxe;…
The phase transformations of a series of decaprismatic Al-Co-Ni crystals were studied in situ by X-ray diffraction between ambient temperature and 1573 K. Five samples in the composition range Al74—70Co22—6Ni4—23 were investigated. In a small range at high temperatures, all specimens showed the diffraction pattern of…
This paper describes the hydrolytic degradation of three stereoregular poly(ester amides) which were obtained by polycondensation reaction of 1-amino-1-deoxy-2,3,4-tri- O -methyl-5- O -[(pentachlorophenoxy)succinyl]- l -arabinitol, 1-amino-1-deoxy-2,3,4-tri- O -methyl-5- O -[(pentachlorophenoxy)glutaryl]- l -arabinito…
A linear electrooptic coefficient of 0.3 pm/V is induced in a germanosilicate fiber by thermal/electric-field poling. Reducing the fiber thickness by simple mechanical polishing following the poling, leads to a half-wave drive voltage of only 75 V for a 12-cm active length with no measurable linear optical loss in the…
Constitutive equations for the superplastic behaviour of titanium and aluminium aerospace alloys have been presented and computational procedures developed for the determination of the material parameters arising in the equations. The equations include a description of grain growth kinetics with deformation enabling t…
We use the variational cluster approximation to study the relative thermodynamic stability of the spatially uniform phases of binary mixtures of hard rods and discs. The factors promoting the stability of the biaxial nematic phase are identified and discussed. The results suggest that a stable thermotropic nematic bia…
The high pressure d.c. sputtering method has been used to fabricate (YBa/sub 2/Cu/sub 3/O/sub 7//Nd/sub 0.67/Sr/sub 0.33/MnO/sub 3-y/)//sub n/ [(YBCO/NSMO)/sub n/] superlattices. X-ray analyses show c-axis epitaxial growth on LaAlO/sub 3/ (100) substrates. Nd/sub 0.67/Sr/sub 0.33/MnO/sub 3-y/ films are strained due to…
“Classical” superplasticity of SiAlON ceramics with the nominal composition (Y x Li y ) 0.6/(3 x + y ) Si 8.9 Al 3.1 O 2.5 N 13.5 is reported in this study. During deformation, these materials exhibit little microstructural evolution, with negligible growth of elongated β′‐phase grains and minimal texture formation. E…
A study on the effective thermomechanical response of a composite laminate with shape memory alloy (SMA) layers based on the implementation of the layerwise laminate theory in the finite element method is carried out in this paper. The SMA thermomechanical constitutive response is based on a thermomechanical model rec…
Enzymatic oxidative polymerization of p-alkylphenols using horseradish peroxidase as catalyst has been carried out in two polymerization solvent systems: a mixture of phosphate buffer (pH 7) and 1,4-dioxane, and a reverse micellar solution, yielding powdery polymeric materials. The polymer yield was much dependent upo…
Materials such as Terfenol-D that are capable of giant magnetostriction are increasingly being used for sensing and actuation in active and adaptive structures. Designers of such adaptive structures need robust analytical and modeling tools for solving coupled electro-magneto - mechanical boundary value problems. Whil…
Significant advances have been made over the past decade in using computer simulation to investigate the mechanisms associated with defect production by displacement cascades in metals. As reported at COSIRES '92 by Diaz de la Rubia et al. (Rad. Eff. and Def. Sol. 130–131 (1994) 39) and COSIRES '94 by Bacon et al. (Nu…