Effect of rolling and annealing processes on the hardness and electrical conductivity values of Cu-13.5%Mn-4%Ni alloy

It was found that the dendritic microstructure of an as-cast alloy was changed to an almost equiaxed alloy after 480 min of annealing at 700 °C. The electrical conductivity of as-cast and hot rolled samples increased from 27.36 and 30.51% IACS to 30.67 and 32.1% IACS after 480 min of annealing at 700 °C. The dendritic microstructure and the electrical conductivity values of an as-cast alloy annealed for 60 min remained almost unchanged when the annealing temperature was increased to 800 °C. The hardness values of the samples that were hot rolled and annealed for 60 min were higher than those of the as-cast samples for all annealing temperatures. The electrical conductivity values of the hot rolled and as-cast samples were almost the same after annealing at 800 °C for 60 min. It was shown that after 20% cold work, the electrical conductivity value of the as-cast sample decreased from 30.5% IACS to 22.6% IACS. The electrical conductivity values of the samples were not significantly changed when the cold work was increased from 20% to 60%. The electrical conductivity values of the 20%, 40% and 60% cold worked samples increased from 22.62, 24.69 and 26.63 to 27.14,28.36 and 30.55% IACS, respectively, after 30 min annealing at 400 °C.     

Application of cobalt oxide nanoparticles as an electron transfer facilitator in direct electron transfer and biocatalytic reactivity of cytochrome <Emphasis Type="Italic">c</Emphasis>

We describe a modification of glassy carbon (GC) electrode surface with electrodeposited cobalt oxide nanoparticles (CoOx NPs), and then, this electrode is used to immobilization of Cytochrome c (Cyt c). The morphology of electrodeposited CoOx NPs was analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Electrochemical redox property investigation of immobilized protein (Cyt c) molecules was accomplished by cyclic voltammetry (CV) technique. Cyt c/CoOx NPs/GC electrode exhibits electron transfer between the protein prosthetic groups and electrodeposited nanoparticles on the electrode surface and displayed a couple of stable redox peaks with a formal potential (E°^′) of −89.5 mV (107.5 mV vs. NHE) with respect to reference electrode in 0.05 M phosphate buffer solution (pH 7.0). The experimental results demonstrated that Cyt c/CoOx NPs/GC biosensor exhibited electrocatalytic activity toward the reduction of hydrogen peroxide and application to hydrogen peroxide determination was exemplified.     

Nondestructive Characterization of Microstructure and Mechanical Properties of Heat Treated H13 Tool Steel Using Magnetic Hysteresis Loop Methodology

ABSTRACT

The aim in this article is to evaluate microstructural changes, hardness variations, and wear behavior of H13 hot work tool steel as a function of austenitizing and tempering temperature using nondestructive magnetic hysteresis loop method. To obtain different microstructural characteristics in the H13 specimens, austenitizing and tempering temperatures were varied in the range of 1,050–1,100°C and 200–650°C, respectively. The microstructural features, hardness, and wear loss were characterized using X-ray diffraction/metallographic examinations, hardness measurements, and a pin-on-disk wear tester, respectively. The relations between features obtained from the conventional methods and parameters extracted from the magnetic hysteresis loops were established. Results demonstrate that the proposed nondestructive method is able to assess the wear behavior of the heat treated H13 tool steels. Besides, a standard Generalized Regression Neural Network (GRNN) was trained with a training dataset and then used to estimate the hardness of a given sample with its measured values of magnetic parameters. Experimental results indicate that, if the training dataset has sufficient samples, the proposed method will have a very high accuracy to estimate hardness of the sample, nondestructively.     

Culture, personality, and subjective well-being: Integrating process models of life satisfaction.

The authors examined the interplay of personality and cultural factors in the prediction of the affective (hedonic balance) and the cognitive (life satisfaction) components of subjective well-being (SWB). They predicted that the influence of personality on life satisfaction is mediated by hedonic balance and that the relation between hedonic balance and life satisfaction is moderated by culture. As a consequence, they predicted that the influence of personality on life satisfaction is also moderated by culture. Participants from 2 individualistic cultures (United States, Germany) and 3 collectivistic cultures (Japan, Mexico, Ghana) completed measures of Extraversion, Neuroticism, hedonic balance, and life satisfaction. As predicted, Extraversion and Neuroticism influenced hedonic balance to the same degree in all cultures, and hedonic balance was a stronger predictor of life satisfaction in individualistic than in collectivistic cultures. The influence of Extraversion and Neuroticism on life satisfaction was largely mediated by hedonic balance. The results suggest that the influence of personality on the emotional component of SWB is pancultural, whereas the influence of personality on the cognitive component of SWB is moderated by culture. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Investigation of Proposed Concrete Filled Steel Tube Connections under Reversed Cyclic Loading

Concrete-filled steel tube (CFT) columns are used in the primary lateral resistance systems. The objective of this research is to analyse the behavior of the steel beam to CFT column connections. A three-dimensional numerical model for simulating the behavior of CFT connections was developed with the aid of the general purpose nonlinear finite element analysis package ABAQUS. In this paper, 90 CFT connection specimens include simple and moment connections that were tested under reversed cyclic loading. Shear capacity of joint, moment-drift response, energy absorption, and displacement ductility were studied in those models. The results have indicated that, the hysteresis curve of CFT columns was plump; no pinch phenomenon can be found; the damage and degradation degree of the strength and stiffness of specimens is lower; and high energy dissipation capacity can be achieved. Improvement in the behavior of CFT connection depends on the beam characteristics and column features.     

Temperament and personality: Origins and outcomes.

This article reviews how a temperament approach emphasizing biological and developmental processes can integrate constructs from subdisciplines of psychology to further the study of personality. Basic measurement strategies and findings in the investigation of temperament in infancy and childhood are reviewed. These include linkage of temperament dimensions with basic affective–motivational and attentional systems, including positive affect/approach, fear, frustration/anger, and effortful control. Contributions of biological models that may support these processes are then reviewed. Research indicating how a temperament approach can lead researchers of social and personality development to investigate important person–environment interactions is also discussed. Lastly, adult research suggesting links between temperament dispositions and the Big Five personality factors is described. (PsycINFO Database Record (c) 2010 APA, all rights reserved)