نتایج جستجو برای: current efficiency

تعداد نتایج: 1131400  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه ارومیه 1377

the methods which are used to analyze microstrip antennas, are divited into three categories: empirical methods, semi-empirical methods and full-wave analysis. empirical and semi-empirical methods are generally based on some fundamental simplifying assumptions about quality of surface current distribution and substrate thickness. thses simplificatioms cause low accuracy in field evaluation. ful...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده برق و کامپیوتر 1392

abstract nowadaysphotovoltaic solar cells (pvs) areacknowledged the fastest growing energy technology in the word, however, they only account for only fraction of current global renewable energy capacity. it isrecognized that this incomplete market penetration has been largely a result of the technology’sexcessive cost. so researchers are trying to find innovative, economic way with theaim of ...

Journal: :journal of membrane science and research 0
krishnaveni venugopal department of mechanical engineering, anna university, guindy chennai 600025, tamil nadu, india sangeetha dharmalingam department of mechanical engineering, anna university, guindy chennai 600025, tamil nadu, india

in this study, polystyrene ethylene butylene polystyrene (psebs) was functionalized to prepare mono and bipolar ion exchange membranes. in the case of the bipolar membrane, platinum was used as the intermediate layer. nacl solution of concentration ranging from 5 g/l to 25 g/l was used as the feed solution. a commercially procured ion exchange membrane made of polystyrene divinyl benzene was al...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی خواجه نصیرالدین طوسی - دانشکده برق و کامپیوتر 1391

in the area of automotive engineering there is a tendency to more electrification of power train. in this work control of an induction machine for the application of electric vehicle is investigated. through the changing operating point of the machine, adapting the rotor magnetization current seems to be useful to increase the machines efficiency. in the literature there are many approaches wh...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده مدیریت 1392

data envelopment analysis (dea) is a powerful tool for measuring relative efficiency of organizational units referred to as decision making units (dmus). in most cases dmus have network structures with internal linking activities. traditional dea models, however, consider dmus as black boxes with no regard to their linking activities and therefore do not provide decision makers with the reasons...

Journal: :آب و خاک 0
یوسف رمضانی مهدی قمشی

abstract turbidity current is one of the most important factors that effect the sediments distribution and also their transportation and release from reservoir. in this study, effects of these currents on sedimentation process in sefidroud dam were simulated by tcm model in 30 years period. comparison between the case of turbidity currents that reach to the dam wall and release from the reservo...

Journal: :Journal of the Metal Finishing Society of Japan 1972

Journal: :Science 2011
Robert E Blankenship David M Tiede James Barber Gary W Brudvig Graham Fleming Maria Ghirardi M R Gunner Wolfgang Junge David M Kramer Anastasios Melis Thomas A Moore Christopher C Moser Daniel G Nocera Arthur J Nozik Donald R Ort William W Parson Roger C Prince Richard T Sayre

Comparing photosynthetic and photovoltaic efficiencies is not a simple issue. Although both processes harvest the energy in sunlight, they operate in distinctly different ways and produce different types of products: biomass or chemical fuels in the case of natural photosynthesis and nonstored electrical current in the case of photovoltaics. In order to find common ground for evaluating energy-...

پایان نامه :0 1374

the rationale behind the present study is that particular learning strategies produce more effective results when applied together. the present study tried to investigate the efficiency of the semantic-context strategy alone with a technique called, keyword method. to clarify the point, the current study seeked to find answer to the following question: are the keyword and semantic-context metho...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید