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Correlation Technique (correlation + technique)
Selected AbstractsRoom-Temperature Degradation of t -Zr(Pr)O2 in an Aqueous Suspension Revealed by Perturbed Angular CorrelationsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2008Marķa C. Caracoche This paper deals with the phase stability of an aqueous suspension of tetragonal Zr0.9Pr0.1O2 (20 wt%/vol%) at room temperature as a function of the aging time. The suspension is investigated in situ using the highly localized Perturbed Angular Correlations technique. The results indicate that an almost fully reversible degradation process toward monoclinic zirconia takes place through a first-order reaction of rate constant k=0.7 day,1. Two successive diffusion mechanisms are observed that are interpreted as OH, ions' migration in the grain surface and then, as proton defects' diffusion into the bulk. [source] Non-linear approaches for reducing large power systemsEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 3 2001X. Lei Issues on the establishment of equivalent networks are becoming essential for the deregulated power market. This paper presents a comprehensive tool for network reduction of large power systems. Through integrating different methodologies into a simulation program, the dynamic equivalent can be established by adopting one common database. With a readily integrated modified Gauss-Newton algorithm, network reduction can be executed under the dynamic conditions either in the time domain or in the frequency domain in coping with nonlinear nature of the system involved. Furthermore, a novel algorithm based on dynamic coherency approach implemented readily into the simulation program is also presented. This novel approach determines coherent generators on non-linear basis in the time domain using the cross correlation technique, taking dynamic characteristics of the system involved into consideration. Two case studies are presented in this paper. Each of the non-linear approaches presented is applied for one of the case studies as application example. The results achieved validate the functionality of the approaches presented. [source] Fatigue damage analysis in a duplex stainless steel by digital image correlation techniqueFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 2 2008A. EL BARTALI ABSTRACT Strain field measurements by digital image correlation today offer new possibilities for analysing the mechanical behaviour of materials in situ during mechanical tests. The originality of the present study is to use this technique on the micro-structural scale, in order to understand and to obtain quantitative values of the fatigue surface damage in a two-phased alloy. In this paper, low-cycle fatigue damage micromechanisms in an austenitic-ferritic stainless steel are studied. Surface damage is observed in real time, with an in situ microscopic device, during a low-cycle fatigue test performed at room temperature. Surface displacement and strain fields are calculated using digital image correlation from images taken during cycling. A detailed analysis of optical images and strain fields measured enables us to follow precisely the evolution of surface strain fields and the damage micromechanisms. Firstly, strain heterogeneities are observed in austenitic grains. Initially, the austenitic phase accommodates the cyclic plastic strain and is then followed by the ferritic phase. Microcrack initiation takes place at the ferrite/ferrite grain boundaries. Microcracks propagate to the neighbouring austenitic grains following the slip markings. Displacement and strain gradients indicate probable microcrack initiation sites. [source] Childhood trauma has dose-effect relationship with dropping out from psychotherapeutic treatment for bulimia nervosa: A replicationINTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 2 2001Jennifer Mahon Abstract Objective The primary goal of this study was to replicate the finding that experiences of childhood trauma have a dose-effect relationship with dropping out from psychotherapeutic treatment for bulimia nervosa. It also aimed to replicate logistic regression findings that parental break-up predicts dropping out. Method The cohort consisted of 114 women consecutively presenting to an outpatient eating disorders clinic with bulimia nervosa or atypical bulimia nervosa. Data were gathered using a retrospective, case-note approach and were analysed using logistic regression (LR). A correlation technique was employed to assess the presence of a dose-effect relationship between experiences of trauma in childhood and dropping out. LR models were double cross-validated between this and an earlier cohort. Results The dose-effect relationship between experiences of childhood trauma and dropping out was confirmed. Witnessing parental break-up in childhood again predicted dropping out of treatment in adulthood. Cross-validation of LR equations was unsuccessful. Discussion These results strongly suggest that experiences of childhood trauma have a dose-effect relationship with dropping out. Parental break-up is a stable predictor of dropping out. It is possible that these experiences influence attachment style, particularly the ability to make and maintain a trusting relationship with a psychotherapist. Clinical implications are discussed. © 2001 by John Wiley & Sons, Inc. Int J Eat Disord 30: 138,148, 2001. [source] | ||||||||||