نتایج جستجو برای: reduction rate
تعداد نتایج: 1386431 فیلتر نتایج به سال:
the hypothesis is that recent and frequent exposure to lexical items leads to a more fluent production of speech in terms of rate of speech. to test the hypothesis,a one-way anova experimental design was carried out. 24 sednior students of efl participated in a one-way interview test. data analyses revealed that those who were exposed frequently to the lexical items over a week prior to inter...
In this study, the isothermal reduction of iron oxide pellets, made of Iranian Chadormalo, Gole-gohar, and Sangan iron ores, was investigated in the temperature range of 900-1100°C. Tabas, Pabdana, Babnizoo, Karmozd, and Shahrood domestic coals were used as reductants. Parametric studies were performed and the effects of such factors as temperature, average particle size of iron ore and coal fi...
this paper tries to determine efficiency of noise control method using fuzzy logic and based on collected data. from among various methods of noise control in workplace, sex methods (enclosure, installing noise absorber, enclosure and absorber, active, and administrative control, and personal protective equipment) were typically selected based on experts' judgment. for each of selected control ...
In this study, the isothermal reduction of iron oxide pellets, made of Iranian Chadormalo, Gole-gohar, and Sangan iron ores, was investigated in the temperature range of 900-1100°C. Tabas, Pabdana, Babnizoo, Karmozd, and Shahrood domestic coals were used as reductants. Parametric studies were performed and the effects of such factors as temperature, average particle size of iron ore and coal fi...
Introduction: Nominal noise reduction rate of the earmuff manufacturers can be different compared with the actual attenuation rate. The present study aimed to determine the actual noise reduction rate of common hearing protection devices using microphone in real ear method. Materials and Methods: In this study, five brands of common earmuffs used in Iranian industries were investigated on 30...
In the present study, reduction of zinc oxide from the pellets made of steelmaking electric arc furnace dust has been investigated. Effects of such parameters as the type of carbon material (graphite, coke and charcoal) as well as time and temperature on the reduction reaction have been examined. The reduced (dimensionless) time method was applied to perform a kinetic analysis of the system. Ex...
برای اطمینان از درستی کارکرد فرآیند های صنعتی، نیاز به ابزارهایی هست که وضعیت های نامطلوب عملکرد فرآیند را با دقت و سرعت بالا به راهبر فرآیند نشان دهد. یک روش موثر برای تشخیص و ردیابی عیوب، به کاهش اثر این عیوب، تأمین ایمنی عملیات، کم کردن عدم زمان کارکرد و کاهش هزینه های بازسازی کمک می کند. در حال حاضرbayesian belief networks (bbns) از جمله روش های مورد توجه جهت تعیین و تشخیص عیوب فرآیندها به ...
a hydroponics study was carried out in order to understand the behavior of antioxidant enzymes, soluble protein content and its effect on cell death in different old leaves of durum wheat. two month after planting, the different old leaves were sampled and the activity of super oxide dismutase (sod), catalase, ascorbat peroxidase and guaiacol peroxidase were measured. furthermore, the rate of c...
ارزیابی عملکرد آکوستیکی مانکن سر جهت استفاده در آزمون های تعیین قدرت کاهندگی صدای وسایل حفاظت شنوایی
Introduction:One of the recommended methods for evaluation effectiveness of hearing protection is use the acoustic fixture accordance with standard ISO 4869-3. The aim of this study was evaluate the acoustic performance of fixture for using in noise reduction rate tests of hearing protection devices in the laboratory. Methods: In this cross-sectional study , noise reduction rates o...
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