"Iron-Deficient" YIG?

In a recent letter to this TRANSACTIONS [1], Guyot, Cagan, and Merceron claim to have measured the initial permeabilities, at different constant temperatures, as a function of frequency, of "iron-deficient" yttrium iron garnet (YIG). They attribute the nature of their results to the presence of Fe⁴⁺ions in their samples, which provide a means of valency interaction. The method of preparation of the polycrystalline material on which these measurements were made is given in another letter [2] by the same authors. This author wishes to point out that this method, taken at face value, will not produce the material they claim. In fact, it is very unlikely that an "iron-deficient" YIG, which might be written Y3Fe5-δO12, with measurable δ, can be produced at all.     

It takes more than information to save energy.

Contributes to the M. L. Dennis et al (see record 1991-08669-001) review of social and behavioral science literature related to the failure to change human behavior on a large scale for energy conservation and environmental protection. It is suggested that behavioral and social scientists can increase corporations' and governments' environmentally protective behavior by helping them develop more effective environmental programs with the information-dissemination approaches reviewed by Dennis et al. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of retained austenite on contact fatigue in Cr−Ni−W carburized steel

This article describes an experiment to determine the effect of retained austenite on the chipping of the case-hardened layer of Cr−Ni−W carburized steel by examining the same case-hardened layer with varying amounts of retained austenite after different heat treatments. The existence of a critical load level was established; contact fatigue resistance can be improved when the loads are above critical. This is determined by deformation of the austenite structure and substructure, the austenite-martensite transformation under the influence of the load, and the retention of the deformed austenite structure in the martensite. Authors' Note: Alloyed steel compositions are presented in the Soviet standard. The first two numbers give the approximate carbon content in hundredths of a percent. The number after the element shows the approximate percentage of the alloying elements. The number one or no number at all means the percentage is about one or less. Bertold B. Vinokur earned his Doctor of Technical Science in physics of metals and metal science at the Ukrainian Academy of Science, Ukraine, in 1978. He is currently retired. Dr. Vinokur is a member of TMS. Alexandr L. Geller earned his Doctor of Technical Science in metal science and heat treatment at Donetsk Technical University, Ukraine, in 1997. He is currently an assistant professor in the Department of Materials Science and Engineering at Donetsk Technical University, Donetsk, Ukraine.     

Collaborative versus directive interventions in the treatment of eating disorders: Implications for care providers.

Given that individuals with eating disorders, are typically ambivalent about changing their eating patterns, what approach is most helpful in working with this challenging group? This research compared the responses of clients with eating disorders and those of care providers to written clinical vignettes. All participants rated collaborative interventions as more acceptable and more likely to produce positive clinical outcomes than directive interventions. In addition, clients who were least ready for change rated directive interventions as less acceptable and less likely to produce adherence than did clients who were more ready. Despite participants' clear preference for collaborative interventions, directive interventions were rated as equally likely to occur. The implications of participant preferences and reasons that these preferences may not be reflected in actual clinical practice are addressed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Information content of the scattering matrix for spheroidal particles

The T-matrix method is shown to be an efficient and accurate procedure for calculating the scattering matrix for randomly oriented nonspherical particles. Calculated scattering matrix elements for spheroidal particles are identical to those obtained by the spheroidal harmonic approach. T-matrix calculations for a randomly oriented finite length cylinder agree well with microwave scattering measurements. Analysis of the information content of the angular variation of the matrix elements for a set of moderately sized absorbing spheroidal particles is presented. It is found that the Fourier spectrum of the phase function and a parameter related to the depolarization ratio contain particle size and shape information, respectively.     

Efficient Transitive Closure Reasoning in a Combined Class/Part/Containment Hierarchy

Class hierarchies form the backbone of many implemented knowledge representation and reasoning systems. They are used for inheritance, classification and transitive closure reasoning. Part hierarchies are also important in artificial intelligence. Other hierarchies, e.g. containment hierarchies, have received less attention in artificial intelligence. This paper presents an architecture and an implementation of a hierarchy reasoner that integrates a class hierarchy, a part hierarchy, and a containment hierarchy into one structure. In order to make an implemented reasoner useful, it needs to operate at least at speeds comparable to human reasoning. As real-world hierarchies are always large, special techniques need to be used to achieve this. We have developed a set of parallel algorithms and a data representation called maximally reduced tree cover for that purpose. The maximally reduced tree cover is an improvement of a materialized transitive closure representation which has appeared in the literature. Our experiments with a medical vocabulary show that transitive closure reasoning for combined class/part/containment hierarchies in near constant time is possible for a fixed hardware configuration. Received 10 January 2000 / Revised 25 November 2000 / Accepted in revised form 9 February 2001     

Effect of surface-active substances on the synthesis of fibre-forming acrylonitrile copolymers

Conclusions The effect of surface-active substances on the synthesis of fibre-forming acrylonitrile copolymers in aqueous sodium thiocyanate solutions has been studied.Increasing the content of surface-active substances in the reaction medium leads to a decrease in the overall activation energy of the copolymerization reaction and to a certain increase in the molecular weight of the copolymer.Translated from Khimicheskie Volokna, No. 3, pp. 26–27, May–June, 1985.     

How additives of graft copolymers affect the structural-mechanical properties of fibres from mixtures of incompatible homopolymers

Conclusions 1. The authors have studied the effect of the composition of a CA-PAN mixture and their graft copolymers on the physicomechanical properties of fibres formed from them. It is shown that the physicomechanical properties of the fibre deteriorate with increasing ratio of CA and PAN in the mixture. The presence of graft copolymer in a CA-PAN mixture improves the fibre's physicomechanical properties.2. The structural characteristics of CA-PAN fibres and their graft copolymers have been studied by physicomechanical and electron-microscopic methods. It is shown that addition of a graft copolymer of CA and PAN to a heterogeneous mixture of CA and PAN leads to homogenisation of the structure and an increase in the structural homogeneity of the fibres.Tashkent Institute of the Textile and Light Industries. Translated from Khimicheskie Volokna, No. 6, pp. 20–23, November–December, 1969.     

SOME OBSERVATIONS ON THE DEHYDRATION AND FIRING BEHAVIOR OF CLAYS1

The results of laboratory studies of the drying and water-smoking behavior of twelve clays, typical of those used in the manufacture of clay structural units, are given and correlated with data obtained at plants during the firing of ware made from these same clays. There is evidently considerable difference in the time required to dry the materials investigated and it is indicated that the fire clays as a group are considerably more difficult to dry than are shales and surface clays. The results also indicate that the removal of hygroscopic and chemically combined water, as initially contained in the clay, are not important factors in regard to the time required to watersmoke and fire clay ware under plant conditions. With proper equipment it would appear to be possible to fire clay ware, approximating brick and paving block in size and shape, to 1832°F in 20 hours, but that the following conditions in practice may necessitate a longer firing time than that shown to be satisfactory in the laboratory: (1) the heating of ware which is not “bone dry” and which necessitates completion of the drying operation in the kiln; (2) the time required to complete oxidation; (3) the limitations necessitated by the kiln construction, the brick work of which may be destroyed by too rapid heating and cooling; (4) limitations of kiln design because of which enormous differences in temperature would develop throughout the setting by too rapid heating; and (5) insufficient movement of furnace gases to promptly remove all water vapor.