Materials Literature
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The variation of apparent KIc with crack length is being studied using a variety of commercial ceramic materials. Test methodology is much the same as has been used in the past for natural rock (notched bend test). Where sufficiently definitive data have been obtained, each material showed decreasing KIc with decreasi…
Various mechanisms have been invoked in the past to explain the effects of catalysts on the gasification reactions of carbon. However in many cases the observed catalytic behavior can be interpreted in terms of oxidataion‐reduced cycles occurring on the carbon surface. This paper describes how the techniques of therma…
The chemistry of nitroalkanes has been used to develop two rational synthetic routes to the new class of Cmethylated chlorins.
The potential of Fourier-Transform Infrared (FTIR) spectroscopy for characterizing polyethylene terephthalate (PET) fibers is examined both from a practical and a theoretical view point. Problems associated with sample preparation, spectral data analysis, and refraction and reflection at the fiber surfaces are discuss…
A simple single‐extraction procedure for measuring exchangeable cations and effective CEC (ECEC, the CEC at natural pH and ionic strength) has been developed for routine advisory soil analysis. The method is based on the use of Sr (1.26M SrCl2) to displace exchangeable cations and effective CEC is taken as the sum of…
We pyrolyzed PVC with and without the char-promoters iron (III) pyromellitate, zinc pyromellitate, and MoO3 (1 phr) under isothermal conditions (207°C, nitrogen) and analyzed the soluble and insoluble residues to characterize the reactions important to charring. Both pyromellitates, apparently acting as their metal ch…
Abstract Deprotonated N ‐phenyl, N ′, N ′‐dialkylthiourea (PhtuR 2 ) complexes of Cu(I) and Cu(II) have been isolated and the existence of a Cu(III) complex inferred from electrochemical measurements. The crystal structure of Cu(I)[(C 6 H 5 )NC(S)N[(C 2 H 4 ) 2 O]] (space group P l̄, Z = 24, a = 10.487(9), b = 28.961(…
A high-yield six-step synthesis of sequirin D (1a), a naturally occurring norlignan, is described. Michael addition of deoxyanisoin (2) to acrylonitrile gives a ketonitrile (3), which on Wolff–Kishner reduction is reduced and hyrolysed in situ to 4,5-bis-p-methoxyphenylpentanoic acid (4). Cyclodehydration of (4) with…
In aqueous dimethylformamide solution meso-αααα-tetra(o-maleamoylphenyl)porphyrin undergoes rapid metal incorporation (CuII, ZnII, CoII, and NiII) by a mechanism featuring rate-determining intramolecular transfer of the metal ion from the carboxylate binding site to the porphyrin nucleus.
The fact that the polarization-related electrostrictive coefficients Q in the relaxor type ferro-electrics are almost an order of magnitude smaller than in most normal ferroelectric perovskites can be explained under the assumption that the temperature dependence of the soft-mode TO phonon frequency is given as ω2 TO…
—This paper summarizes experimental results obtained during the study of the production of nitrogen oxides in a well stirred reactor burning hydrocarbons. First, the particular problem of NO and NO2 probing has been addressed, and it has been shown experimentally that NO → NO2 conversion actually occurs within the pro…
The metal-insulator transition in Ti2O3 is described as a bandcrossing transition, an electron-hole gas forming when its free energy becomes greater than the gap.
The 13C n.m.r. spectrum of high-spin chloro(5,10,15,20-tetraphenylporphyrinato)iron(III) has been unambiguously assigned using porphyrins isotopically enriched at selected positions. The unexpected linewidth of the resonances of the porphyrin core carbons is explained by the dipolar interaction of the carbon nuclei wi…
The fatigue properties associated with the β1\ ightleftarrowsβ1′ transformation pseudoelasticity cycling of Cu–Al–Ni alloy single crystals have been investigated by cyclic loading tests and fractographic observations. Fatigue life is surprisingly short even under 100 MPa of applied stress, although the static fracture…
A phenomenological theory separating an isochronal data of temperature dispersion of the complex dynamic modulus function of PET into α, β, and γ relaxation mechanisms (αI, αII, β, γI, γII, and γIII) was proposed on the basis of the following three assumptions: (1) additivity for assessing the contribution of each rel…
The thermal decomposition and the glass transition temperature of poly-p-tert-butylstyrene (PptBuS) were studied with a (DSC-2) differential scanning calorimeter. The undecomposed and decomposed polymers were analyzed by gel permeation chromatography for molecular weight distributions and by DSC-2 for changes in the p…
A tripod field is used as model for a general anisotropic fluid. The elastic energy density is expanded as invariant polynomial in the components of the contortion tensor. Surface energy terms are derived from compatibility conditions for the tripod field. The model is applied to cholesteric liquid crystals of large a…
Skinfold thickness measurements on 626 normal subjects of both sexes between the ages of 5 months and 73 years demonstrated a tri-phasic relationship between loss of skin thickness and age. Measurements for infants of either sex were indistinguishable and high, falling rapidly to levels which only changed slightly ove…
In order to find a sulfide solid electrolyte with high ionic conductivity, the electrical conductivities of alkaline earth sulfides and CaS doped with a rare earth sulfide or a titanium group sulfide were measured by the ac bridge-complex impedance plot method at 1073–1673 K. From the dependence of the conductivity on…
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