نتایج جستجو برای: systematic method total 30 samples in each area soil samples were taken in 0

تعداد نتایج: 17724416  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید چمران اهواز - دانشکده ادبیات و علوم انسانی 1386

the purpose of the present study is to find out whether bilinguals of khuzestan-arab origin or monolinguals of iranian origin code-switch during learning or speaking english and which group is more susceptible to code-switch. to this end, the students of 24 classes from high schools and pre- university centers were screened out, and interviewed and their voices and code-switchings were recorded...

پایان نامه :0 1374

the following question poped up: is there any relationship between iranian high school efl learners reading comprehension and listening comprehension? then the following null hypothesis (ho) was developed to the test the above, mentioned question. "there is no relationship between high school efl learners reading comprehension and listening comprehension. for nearly 16 weeks, the experimental g...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه ارومیه - دانشکده ادبیات 1391

this study investigated the effects of three kinds of gloss conditions, that is traditional non-call marginal gloss, audio gloss, and extended audio gloss, on reading comprehension and vocabulary gain of iranian upper- intermediate efl learners. to this end, three experimental and one control groups, each comprising 15 participants, took part in the current study. in order to ensure that the pa...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - پژوهشکده فنی و مهندسی 1388

asymmetric polyethersulfone (pes) microfiltration flat sheet membranes were composed by the phase inversion method (pim) and were used as supports. composite membranes were fabricated by coating silicone rubber as selective layer. effect of different concentrations of pes and pdms and different solvent such as nmp, dmf and dms effects as pes solvents and support thickness and different coagulat...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی عمران 1391

one of the most commonly used techniques to reduce the corrosion rate of rebar in concrete is addition substances named corrosion inhibitors into the concrete. corrosion inhibitor is chemical compounds that were added to concrete to prevent corrosion of steel in concrete. sodium nitrate is a type of anodic inhibitors that this study investigatesthe effect of this inhibitor on the properties of ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - پژوهشکده علوم زمین سازمان زمین شناسی و اکتشافات مع 1390

the neogene intrusion masses in the noudeh-enghelab area located to the north of sabzevar ophiolite have cut the late cretaceous ophiolitic rocks, sedimentary- volcanic and eocene volcanic rocks and have been covered by pliocene and quaternary deposits. the margin is of lava with basalt, phyric andesite-basalt and andesite and the central parts (dome shaped) composed of phyric andesite-trachyan...

خادمی, حسین, دهقان, رمضانعلی , شریعتمداری, حسین ,

  Studying soil phosphorus fractions is useful in understanding soil pedogenesis as well as soil fertility. In this reseach, 20 soil samples were taken from different depths of 0-30 and 30-60 cm of upper-slope, mid-slope and lower-slope positions of four toposequences in arid (Jei and Ziar in Isfahan) and semiarid (Farokhshahr and Shahrekord) regions. In each toposequence, the soil depth was re...

Soil productivity and plant growth are usually affected by biological activities of earthworms. The objective of this study was a comparative evaluation of earthworm abundances in 20-year-old plantations of Alder, Oak, Maple and Cypress with the adjacent natural mixed broad-leaved deciduous forest in the Caspian region of Iran. In this research one sample plot, each 1 ha; was selected in every ...

Journal: :زمین شناسی اقتصادی 0
فاطمه هرمزی نژاد فاطمه راست منش علیرضا زراسوندی

introduction soil plays a vital role in human life as the very survival of mankind is tied to the preservation of soil productivity (kabata- pendies and mukherjee, 2007). the purpose of this study is the assessment of heavy metal contamination (zn, mn, pb, fe, ni, cr) of the soil around the khuzestan steel complex. materials and methods for this purpose, 13 surface soil samples (0-10 cm) were t...

Journal: :مرتع و آبخیزداری 0
محمد جعفری استاد، دانشکده منابع طبیعی، دانشگاه تهران، حسین آذرنیوند استاد، دانشکده منابع طبیعی، دانشگاه تهران احمد صادقی پور استادیار، دانشکده کویرشناسی، دانشگاه سمنان نادیا کمالی پور دکتری مرتعداری، دانشکده منابع طبیعی، دانشگاه تهران احمد حیدری دانشیار، دانشکده مهندسی و فناوری کشاورزی، دانشگاه تهران حسن مداح عارفی دانشیار، مؤسسه تحقیقات جنگل ها و مراتع

global warming and climate change have drawn special attention to soil and its potential for stable carbon sequestration. soils are the largest stores of carbon in terrestrial carbon cycle and contain about three times more carbon than vegetation cover and two times more than that of atmosphere. studying the effects of grazing on soil carbon storage is important because of the major role soil o...

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