نتایج جستجو برای: fresh water
تعداد نتایج: 596009 فیلتر نتایج به سال:
The purpose of the research was to study the effect of microwave power inpretreatment of fresh waterhyacinth on biogas production. The variations of microwave power levels are 240; 400; 560 and 800 W. The variations of microwave heating time are 5; 7 and 9 min. The unpretreated fresh water hyacinth are used as control. The result of research showed that the microwave pretreatment of fresh water...
Biological approaches for addressing the grand challenge of providing access to clean drinking water
The U.S. National Academy of Engineering (NAE) recently published a document presenting "Grand Challenges for Engineering". This list was proposed by leading engineers and scientists from around the world at the request of the U.S. National Science Foundation (NSF). Fourteen topics were selected for these grand challenges, and at least seven can be addressed using the tools and methods of biolo...
BACKGROUND In arid and semi-arid countries there are often large areas where groundwater is brackish and where people have to obtain water from irrigation canals for all uses, including domestic ones. An alternative to drawing drinking water directly from irrigation canals or village water reservoirs is to use the water that has seeped from the irrigation canals and irrigated fields and that ha...
How do countries that share cross-border rivers respond to periods of abnormally low water availability? This article argues that understanding whether countries react cooperatively or conflictually to within-basin shortages is just as important as identifying the influence of cross-basin differences in absolute availability. To study the effects of within-basin, relative scarcity, the article ...
Rice is the staple food and rice production consumes about 50% of the fresh water resources in China. In addition, drought is one of the most important constraints in rice resulting in large yield losses and limiting the average yield increase of the country. There is an urgent need to enhance water-saving (W) capacity or drought resistance (DR) of rice. WDR varieties can be developed through i...
Conventional techniques for assessing and monitoring water quality have been primarily based either on the use of living material as “bioindicators” or on the employment of analytical measurements to provide information about the physical and chemical status of aquatic ecosystems. The former have predominantly utilised the presence of selected species to indicate the quality of waters in which ...
Four topics were studied concerning the modeling of ground-water flow in coastal aquifers with analytic elements: (1) practical experience was obtained by constructing a ground-water model of the shallow aquifers below the Delmarva Peninsula USA using the commercial program MVAEM; (2) a significant increase in performance was obtained by implementing the theory for variable density flow in a co...
The color of freshwaters, often measured as absorbance, influences a number of ecosystem services including biodiversity, fish production, and drinking water quality. Many countries have recently reported on increasing trends of water color in freshwaters, for which drivers are still not fully understood. We show here with more than 58000 water samples from the boreal and hemiboreal region of S...
Human health risks from cyanobacterial blooms are primarily related to cyanotoxins that some cyanobacteria produce. Not all species of cyanobacteria can produce toxins. Those that do often do not produce toxins at levels harmful to human health. Monitoring programs that use identification of cyanobacteria genus and species and enumeration of cyanobacterial cells as a surrogate for cyanotoxin pr...
Freshwater biodiversity is the over-riding conservation priority during the International Decade for Action - 'Water for Life' - 2005 to 2015. Fresh water makes up only 0.01% of the World's water and approximately 0.8% of the Earth's surface, yet this tiny fraction of global water supports at least 100000 species out of approximately 1.8 million - almost 6% of all described species. Inland wate...
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