نتایج جستجو برای: low temperature and maximum local river inflow

تعداد نتایج: 17122433  

Journal: :محیط شناسی 0
مهرداد نظریها استادیار دانشکده محیط زیست دانشگاه تهران عرفان دانایی دانشجوی کارشناسی ارشد مهندسی محیط زیست دانشگاه تهران سید حسین هاشمی استادیار پژوهشکده علوم محیطی دانشگاه شهید بهشتی امیر حسین ایزد دوستدار مدیر دفتر مطالعات پایه، محیط زیست و میراث فرهنگی شرکت توسعه منابع آب و نیروی ایران

construction and operation of dams have two main effects on streams. at first it increases detention time and then leads to thermal stratification. changing of water quality is the result of these effects and the outflow has different physical, chemical and biological characteristics from inflow.in this study thermal regime in proposed bakhtyari reservoir was simulated with ce-qual-w2 model. th...

ژورنال: علوم آب و خاک 2013
اسلامیان, سعید, حیدرپور, منوچهر , روحی, جابر , مروج الاحکامی, بیتا, مصطفی زاده فرد, بهروز,

Most furrow irrigation systems have low performance due to deep percolation at the upstream end and tailwater runoff at the downstream end of the field. To eliminate this problem improving furrow irrigation performance is necessary. Since the inflow discharge has high effect on infiltration along the furrow which consequently affects the application efficiency and water distribution uniformity,...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده ادبیات و علوم انسانی 1390

abstract birbery and corruption and other criminal and as such is one of social phenomena , and i can firmly say that society is protected and safe from harm , this is criminal . eache community is familiar with these crimes and the crime associated ( direct or indirect ) with the political economic , social , and cultural beliefs and religious issues , especially with the community . admitted...

ژورنال: علوم آب و خاک 2018

Settling basins are one of the most essential structures for the separation of inflow sediments. This structure is established to enhance the water quality after the river-basins and water channels. Numerous studies have been conducted on the design of this structure and different methods have been provided to increase its efficiency. However, the use of simple settling basins with the minimum ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده ادبیات و علوم انسانی 1390

this study was carried out to investigate the effects of integrative vs. instrumental motivation, learning strategy use and gender on iranian efl learners. to this end, 120 efl learners both male and female majoring in english language and literature at shiraz university participated in the study. in order to conduct this study three instruments were used: oxford quick placement test, motivatio...

Journal: :Geosciences 2021

Amvrakikos Gulf is a Mediterranean landlocked, fjord-like embayment and marine protected area suffering from natural, human-induced hypoxia/anoxia massive fish mortality events. Seasonal geophysical oceanographic surveys were conducted focusing on the water-circulation patterns at sill spatial-seasonal distribution of dissolved oxygen (DO) in gulf. Detailed sill, only communication route betwee...

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...

Journal: :تحقیقات مهندسی کشاورزی 0
رضا بهراملو عضو هیئت علمی بخش تحقیقات فنی و مهندسی مرکز تحقیقات کشاورزی و منابع طبیعی همدان

concrete is one of the most important construction materials widely using in hydraulic structures, such as lining of irrigation canals. concrete durability might be decreased due to the environmental or inner factors with physical, chemical or mechanical reactions. since, the climatologically condition is variable in most part of the country, local studies are needed to evaluate of the weakness...

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

in this study, scour of mashkid bridge pier located in mashkid river of saravan county has been studied and to measure the scour rate, the numerical model hec-ras 4.0 has been used. upon selection of mashkid river as the case study and whereas the studied zone is important with respect to the climatic conditions and showery monsoon raining and flowing the great and destructive floodwaters, ther...

Journal: :Sustainability 2022

This study examines the upper basin of Citarum River in West Java, Indonesia, to analyze optimal environmental policy and issues affecting balance between economic activities water environment conservation, for example, controlling quality while maximizing region. The quantitative results derived using model simulation analysis clarifies study’s issues. An integrated linking two sub-models desc...

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