نتایج جستجو برای: due to water shortage problems

تعداد نتایج: 10900053  

Journal: :Ambio 2004
Igor Vasilievich Severskiy

This paper presents results of the research under the program Global International Waters Assessment (GIWA) for the Aral Sea basin (Subregion 24 of the GIWA program). These results show that the detemining factor for the region is freshwater shortage and the main issue is modification of stream flow. According to GIWA assessment estimations, freshwater shortage is responsible for about 70% of t...

Journal: :اقتصاد و توسعه کشاورزی 0
حسین زاد حسین زاد جوادی جوادی حیاتی حیاتی پیش بهار پیش بهار دشتی دشتی

abstract the use of water sources has increased due to extend of agricultural activity for answering food needs of increasing population. while because of exploitation and consumption of water, the use of this restricted resource is not appropriate. consequently in many districts of country the head level of ground water aquifers have been fallen and water level is negative. so, application of ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تحصیلات تکمیلی علوم پایه زنجان - دانشکده فیزیک 1392

in the first part of this thesis we explored wetting and its dynamics for small droplets. first, we showed how a simple feature of water droplets on a surface, i.e. laplace pressure, can be exploited to build a micropump. we investigated capillary pumping in microchannels both experimentally and numerically. putting two droplets of different sizes at the in/outlet of a microchannel, will ge...

پایان نامه :دانشگاه بین المللی امام خمینی (ره) - قزوین - دانشکده علوم پایه 1392

in this thesis,spin dependend transport and electron transport through of ng/sg(graphene/ superconductor graphen) are studied in the junction of ng/fgt/sg. due to andreev reflection conductance increases in the presence of superconductor graphene.also, by applying a voltage gate on a superconductor, fermi level shifts and the conductance is independent of ferromagnatic substrate. also, the cond...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد مرودشت - دانشکده علوم تربیتی و روانشناسی 1392

the purpose of this study was to investigate the relationship between family functioning and marital adjustment humor couples are due to the nature and objectives of the research and application of methods for its implementation correlation was used. the study population consisted of all the couples in the city who uses random cluster sampling of 200 students were selected as sample. data from ...

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

‏‎applications such as high definition viedeo reproduction, portable computers, wireless, and multimedia demand, and ever-increasing need for ligh-frequency high-resolution and low-power analog-to-digital converters. flash, two-step flash, and pipeline convertors are fast but consume large amount of power and require large area. to overcome these problems, successive approximation converter blo...

1995
Jay R. Lund

A mathematical programming approach is developed for deriving estimates of the willingness-to-pay of water customers for improvements in water supply reliability. Reliability is represented as a probability distribution of different shortage levels, allowing the valuation of different profiles of water supply reliability. The approach is examined analytically and a two-stage linear programming ...

Due to the lack of adequate sources of drinking water and uncertainty about the quality of these sources, along with rising water demand due to population growth, it is important to find a suitable solution to supply drinking water. Rainwater harvesting from roofs and use of natural discharge from springs are among techniques which can replace surface and underground water resources. The city o...

Journal: :Environmental Management 2008
Lijin Zhong Arthur P. J. Mol Tao Fu

During the past decades, the traditional state monopoly in urban water management has been debated heavily, resulting in different forms and degrees of private sector involvement across the globe. Since the 1990s, China has also started experiments with new modes of urban water service management and governance in which the private sector is involved. It is premature to conclude whether the var...

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