نتایج جستجو برای: vegetation density of higher than 50 cm

تعداد نتایج: 21303444  

Journal: :iranian journal of public health 0
morteza hajihosseini javad faradmal abdolazim sadighi-pashaki

background: breast cancer (bc) is the second most commonly diagnosed cancer after lung cancer. survival of bc patients is affected by intermediate events. this study was aimed to investigate the disease course of primary non-metastatic bc patients with first recurrence of the tumor (frt) as the intermediate event using the illness- death model. methods: this retrospective cohort study was condu...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم کشاورزی و منابع طبیعی گرگان - دانشکده مرتع و آبخیزداری و شیلات و محیط زیست 1391

مراتع حدود نیمی از خشکی های جهان را در بر دارند و پوشش گیاهی آن در نتیجه تأثیر متقابل محیط و موجودات زنده به وجود آمده است و به عنوان یک اکوسیستم طبیعی مدیریت می شوند. علاوه بر مراتع، راه ها در عصر حاضر نیز از اجزا مهم و زیرساخت های اصلی زندگی نوین و توسعه کشورها به شمار می روند. جاده ها ساخته دست بشر هستند و جوامع گیاهی کنار جاده تحت تأثیر ساخت و ساز قرار دارند. پوشش "رودرال" به مجموعه ای از پ...

Planting shrub seedlings under oil mulches has frequently been used for stabilizing mobile sands in Iran for during the last three decades. Sandy desert of Samad Abad, Sarakhs, northeast Iran, has been fixed by cultivating seedling of Haloxylon aphyllum under the oil mulches. Therefore this study was designed to investigate the effects of the sand fixation project on soil and vegetation propert...

Soil erosion and sand movement is one of environmental threats of the desert areas and vegetation partially prevents the creation of this phenomenon. One of the most important species growing in Sabzevar desert plains and sandy dunes, regarding too dense canopy and their root density, which have a considerable impact on soil protection and prevent movement of sands, is Stipagrostis pennata. ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده ادبیات و علوم انسانی دکتر علی شریعتی 1389

the purpose of this study is to investigate the relationships between teachers’ immediacy behaviors and iranian students’ willingness to talk in english classes. analysis of the results from willingness to talk scale represents a relatively high level of willingness to talk in english classrooms among iranian language learners. the total mean score of students’ willingness to talk was 66.3 ou...

Journal: :پژوهش آب در کشاورزی 0

determination of crops water requirement in different environmental conditions is essential for preparation of precise and suitable irrigation scheduling. the effect of soil compaction and texture on crop coefficient and evapotranspiration of maize was investigated in this study, which was conducted as a factorial experiment with a completely randomized design in a research farm in jey and qaha...

2008
Juying Jiao Wenjuan Bai

The results of field survey, germination and correspondence analysis showed that the soil seed banks density ranged from 900 to 6,467 seeds m at 0-5 cm depth and 117 to 2,467 seeds m at 5-10 cm depth, with species richness of 7-14. Early successional species dominated the soil seed bank, while later successional species occurred only at low density. The similarity between soil seed bank and sta...

Journal: :تحقیقات نظام سلامت 0
سمیه بلقن آبادی دانشجوی کارشناسی ارشد گروه مهندسی بهداشت حرفه ای، دانشکده بهداشت، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران حسینعلی یوسفی مربی، عضو هیأت علمی گروه مهندسی بهداشت حرفه ای، دانشکده بهداشت، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران حبیب اله دهقان استادیار، عضو هیأت علمی، گروه مهندسی بهداشت حرفه ای، دانشکده بهداشت، دانشگاه علوم پزشکی اصفهان، ایران

background: with increased use of computers, exposure to electric and magnetic fields is increasing, the main objective of this study was to evaluate the electric and magnetic field strength in portable computers (laptops) and its relation with eyestrain users. methods: in this cross – sectional study, magnetic and electric fields in 125 laptop computers were measured from 30 cm and 50 cm dista...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه امام رضا علیه السلام - دانشکده زبانهای خارجی 1393

writing an academic article requires the researchers to provide support for their works by learning how to cite the works of others. various studies regarding the analysis of citation in m.a theses have been done, while little work has been done on comparison of citations among elt scopus journal articles, and so the dearth of research in this area demands for further investigation into citatio...

Journal: :مرتع و آبخیزداری 0
مجید آجورلو استادیار گروه مرتع و آبخیزداری، دانشکدة منابع طبیعی، دانشگاه زابل محبوبه ابراهیمیان دانشجوی دکتری آبخیزداری، دانشکدة جنگل داری، دانشگاه پوترا، مالزی رمضانی عبدالله دانشیار دانشکدة مطالعات محیط زیست، دانشگاه پوترا، مالزی

root morphological and distribution responses of signal grass (brachiaria decumbens) to long-term cattle grazing were examined in a tropical pasture in malaysia. the treatments were no grazing by cattle and grazing at a moderate stocking density (2.7 animal unit/ha) under rotational grazing for 33 years. the method consists of taking soil core using a soil corer to a depth of 30 cm and extracti...

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