نتایج جستجو برای: usually without secure underground and surface water supply

تعداد نتایج: 17100190  

Farzad Kazemi, Reza Ali Mohammadpour Tahmtan, Zabihollah Yousefi,

Background: In recent times, the decreasing groundwater reserves due to over-consumption of water resources and the unprecedented reduction of precipitation, during the past 1 decades, have resulted in a change in the volume and quality of water with time. The aim of this study was to determine the spatial and temporal variations of hardness and total dissolved solids in drinking water resource...

2002
F. C. Chow T. Paul John Barnett B. Sellberg

Maximising space in our urban towns and cities remains one of the great challenges of the future. As the need to protect existing green areas grows amid ever increasing demands for more homes and work places, mass transit systems and modern infrastructure, so new approaches must be found to better utilise space available. Improved use of underground space offers new and exciting opportunities f...

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...

2009
Niro Nagai Shigenobu Miyamoto Masaya Nishiwaki Masanori Takeuchi

A programmed software was developed in order to numerically simulate time variation of temperature field and snow depth around a pipe-in-pile snow-melting system, using meteorological data. The system utilized underground piles as heat exchanger between underground soil and water flowing inside the piles. The water was pumped into heat dissipation pipes embedded beneath pavement surface, on whi...

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...

Journal: :اقتصاد و توسعه کشاورزی 0
باریکانی باریکانی احمدیان احمدیان خلیلیان خلیلیان

abstract surface water restriction and supply variation of these resources causes of over extraction of groundwater and unbalance between feed and extraction of groundwater in iran. agricultural sector as the biggest consumer of water resources has the most share of this unsustainability. this paper studies the conjunctive use of surface and groundwater in agronomy production in qazvin basin, o...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1390

abstract ion selective electrodes (ises) are electrochemical sensors that respond selectivity to the activity of ionic species. an ion-selective electrode is an electrochemical device that uses a thin selective membrane or film as the recognition element, and is an electrochemical half-cell equivalent to other half-cells of the zeroth (inert metal in a redox electrolyte). in common methods o...

Predicting the amount of water consumed would help the managers in exploitation of underground water systems so that they could manage consumption effectively. This issue, especially in Iran with repeatedly drought and limited water sources is significantly more important. In the present research, by using, artificial neural networks as a powerful tool in non-linear and indefinite processes hav...

2009
Agnelo R. Silva Mehmet Can Vuran

Many applications for irrigation management and environment monitoring exploit buried sensors wired-connected to the soil surface for information retrieval. Wireless Underground Sensor Networks (WUSNs) is an emerging area of research that promises to provide communication capabilities to these sensors. To accomplish this, a reliable wireless underground communication channel is necessary, allow...

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