Lattice vibrations and bulk properties of ceramics-forming materials: Piezoeffect in SiC and elasticity of ZrO2

The role of lattice vibrations in the crystal properties related to the homogeneous strains is discussed. Such properties depend on the individual phonon characteristics measurable by vibrational spectroscopy. So, being applicable to powderlike samples, it can provide an indirect information on those bulk characteristics which cannot be directly measured for such samples. The piezoelectricity of cubic SiC, and the elasticity of tetragonal ZrO₂ are considered along with the phonon spectra. Thus the mechanism of the polarization of sphalerite-like materials is elucidated; a contradiction between the elastic properties of the t-ZrO₂ lattice and the conventional interpretation of its Raman spectra is revealed.     

Age-related changes in biological parameters in Zucker rats

Changes in a number of morphological and biochemical parameters were observed in genetically obese Zucker rats and in lean controls between 3 and 58 weeks of age. By 3 weeks, the genetically obese rats had higher proportional (wt/100 g body wt) and absolute amounts of adipose tissue, hyperlipemia affecting all the lipid fractions, and hyperproteinemia compared to lean controls. Obesity, hepatomegaly, high concentrations of hepatic lipids and hyperinsulinemia did not appear until the fifth week. In obese animals, liver lipid concentration reached a maximum at 17 weeks of age and then declined. During this time, the triacylglycerol concentrations in the serum remained stable, whereas the cholesterol and phospholipid concentrations continued to increase. The glycogen concentration in obese animals increased, both absolutely and compared to lean controls, between the 12th and 43rd week of age. From weaning, the Zucker rats, compared to lean controls, exhibited characteristics of obesity (accumulation of adipose tissue, hyperlipemia and hyperproteinemia), which persisted to the age of 58 weeks.     

Infrared measurement of total fatty acids in blood serum

Quantitative determination of total fatty acids in rabbit blood serum is achieved using the infrared absorption band, associated with the C = O stretching vibration at 1713 cm^?1 (5.84 μm). Different tests are described to show the validity of this method for a wide range of variation in total concentration and in individual percentages of any one fatty acid. The results are treated by statistical methods, and it is found that infrared analysis is five times more sensitive than methods described previously. This accurate technique, which can be applied to other serums has, for example, been applied to disclose a systematic error in the preparation of total fatty acid samples when nitrogen flushing is not used.     

Annual Report of the C.P.A. Representatives to the International Union of Scientific Psychology (May, 1967).

Presents the annual report of the Canadian Psychological Association representatives to the International Union of Scientific Psychology. Included are brief notes regarding: (1) Summary report of the Moscow Congress; (2) International Directory of Psychologists; (3) The International Review of Psychology; (3) Next international congress; and (4) Next meeting of the Executive Committee. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Déconvolution numérique d’images avec prolongement de spectre

It is possible, for an image, to improve resolution by inverse filtering. But the cutting in the frequency domain, due to this processing, introduces ripples on the restored image, and specially negative values of intensity. The proposed method allows, by spectral extension, to break free from these problems, while image resolution is improved.     

Rapport des Representants de la S.C.P. Aupres de L'union Internationale de Psychologie Scientifique.

Presents the annual report of the Canadian Psychological Association representatives to the International Union of Scientific Psychology. Included are brief notes regarding: (1) Summary report of the Moscow Congress; (2) International Directory of Psychologists; (3) The International Review of Psychology; (3) Next international congress; and (4) Next meeting of the Executive Committee. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Editorial.

Discusses new editorial policies for the Canadian Journal of Psychlogy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Engineering the Virtual Enterprise: An Architecture-Driven Modeling Approach

The managerial and organization practices required by an increasingly dynamic competitive manufacturing, business, and industrial environment include the formation of virtual enterprises. A major concern in the management of virtual enterprises is the integration and coordination of business processes contributed by partner enterprises. The traditional methods of process modeling currently used for the design of business processes do not fully support the needs of the virtual enterprise. The design of these virtual enterprises imposes requirements that make it more complex than conventional intraorganizational business process design. This paper first describes an architecture that assists in the design of the virtual enterprise. Then it discusses business process reengineering (BPR) as a methodology for modeling and designing virtual organizations. While BPR presents many useful tools, the approach itself and the modeling tools commonly used for redesign have fundamental shortcomings when dealing with the virtual enterprise. However, several innovative modeling approaches provide promise for this problem. The paper discusses some of these innovative modeling approaches, such as object-oriented modeling of business processes, agent modeling of organizational players, and the use of ontological modeling to capture and manipulate knowledge about the players and processes. The paper concludes with a conceptual modeling methodology that combines these approaches under the enterprise architecture for the design of virtual enterprises.     

Structural solvability analysis of dynamic process models

The variable structure of dynamic process models is represented by a directed graph termed as the representation graph for the purpose of solvability analysis in this paper. Structural solvability analysis, the determination of the structural differential index and the structural decomposition of the differential–algebraic equations (DAE) model set can be performed using the representation graph. The characteristic features of the representation graph for both index 1 and high index semi-explicit DAE models are presented. Based on the above a novel index reduction procedure for high index models is proposed. The notions and methods are illustrated on simple process examples.     

Effective surface modeling for momentum and heat transfer over rough surfaces: Application to a natural convection problem

In this paper, we propose efficient and suitable effective surface models for steady laminar flows with heat transfer over rough surfaces. These models are developed in the frame of a domain decomposition method and consist in replacing the rough boundaries by effective smooth surfaces on which effective boundary conditions or wall laws are prescribed. The associated effective properties, namely the effective friction and heat transfer coefficients, are determined by the resolution of local closure problems over a representative pattern of the roughnesses. The impact of the flow parameters on these effective coefficients is analyzed, which allows to obtain useful estimates in some specific cases. Finally, two-dimensional numerical experiments are performed for a natural convection problem in a stamp shaped cavity to assess the validity of the proposed effective surface models. Throughout these tests, we also study numerically the impact of the position of the effective surface on momentum and heat transfers.