نتایج جستجو برای: aging

تعداد نتایج: 103665  

In the current study, the sources of variation in the mean hardness value of heat treated aluminum 2024 samples were identified by using metallurgical study and design of experiment methodology (full factorial method). Hardness measurements and microstructural investigations of the samples were carried out using Brinell hardness test and optical microscopy, respectively. The effects of several ...

Journal: :Nippon Ronen Igakkai Zasshi. Japanese Journal of Geriatrics 2009

Jazayeri, Alireza, Moshtagh, Nahaleh,

substance abuse' specially opiates and prescribed drugs are spreading among the older adults. Most of the time it begins as an attempt to medicate chronic pains, medical conditions and loneliness. In other instances, it simply is the continuation of a problem that begun in young adulthood. But scholars and specialists in both fields of Addiction and Gerontology, rather neglected this fast growi...

ژورنال: مواد پرانرژی 2019

In this article the aging of HTPB based composite solid propellants have been studied by Van’t Hoff method. The F-factor of Van’t Hoff equation was calculated by dynamic mechanical analysis (DMA) for reference propellants sample that was equal 2.5. Then the accelerated aging program conditions have been determined by Van’t Hoff equation. According to accelerated aging program the reference prop...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید بهشتی - دانشکده معماری و شهرسازی 1388

چکیده ندارد.

Journal: :journal of electrical and computer engineering innovations 2013
t. g. arora m. v. aware d. r. tutakne

pulse-width modulated (pwm) adjustable frequency drives (afds) are extensively used in industries for control of induction motors. it has led to significant advantages in terms of the performance, size, and efficiency but the output voltage waveform no longer remains sinusoidal. hence, overshoots, high rate of rise, harmonics and transients are observed in the voltage wave. they increase voltag...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 1996
hamed salehi mozaffar eslami mohammad nabi sarbolouki

fourier transform infrared (ftir) and gel permeation chromatography (gpc) wre respectively utilized in determining the changes in isocyanate (nco) concentration and molecular weight (mw) and its distribution (mwd) in polyurethanes during their cure and postcure stages. samples, originally cured at 45°c, were taken through accelerate aging tests at various temperatures. the ftir and gpc analytic...

Journal: :journal of biostatistics and epidemiology 0
elham ahmadnezhad assistant professor, national institute for health, tehran university of medical sciences, tehran, iran zhaleh abdi assistant professor, national institute for health, tehran university of medical sciences, tehran, iran farshid fayyaz-jahani school of medicine, urmia university of medical sciences, urmia, iran mahmod suolduozi school of medicine, urmia university of medical sciences, urmia, iran soraya fatholahi school of public health, tehran university of medical sciences, tehran, iran

b a c k g r o u n d  & aim: this study aimed  to estimate  and project  the current  and future disability burden of typhoid fever in iran associated with climate and population to provide best policies for climate change adaptation. methods & materials: years lost due to disabilities (ylds) were measured as burden estimation in this study. the temperature was selected as climate variable. futu...

Journal: :transport phenomena in nano and micro scales 2013
m. shayesteh m. shafiee afarani a. samimi m. khorram

in this work, boehmite sol was prepared by a previously applied and validated method; hydrolysis of aluminum chloride hexa-hydrate. in order to obtain precise results, the effect of ph after adding precipitating agent, aging time, peptizing temperature and ultrasonic vibration time on the crystallite size of final precipitate were investigated in a narrow range. the preparation conditions appli...

CoHErrelation between weldability and improvement in properties is a key issue in materials science research. The objective of this work is to optimize the process parameters viz., aging temperature, aging time, solutionizing time, to enhance the hardness of Al6061 alloy. Hence, the present paper deals with hardness study of Tungsten Inert Gas welded 6061 aluminium alloy after age hardening und...

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