نتایج جستجو برای: pollution organic index opi
تعداد نتایج: 654918 فیلتر نتایج به سال:
For the last 20-odd years in China, an economic boom has resulted in severe environmental pollution; water pollution, particularly, is of great concern. It has been reported that pollution in China’s overall surface water is rated medium. The water quality of groundwater, lakes and reservoirs has deteriorated. Consequently, such a general distribution of water pollution has posed a grave threat...
In this study, the concentrations of heavy metals (Ca, Zn, Cu, Fe, Mn, Ni) in thesediment of Shavoor River in Khuzestan Province in Iran has been investigated. After the library studies and field studies, six samples of water and sediment were taken from the river in order to evaluate heavy metal pollution in sediments. To determine the geochemical phases of metals in sediment samples the 5-ste...
The present work has been carried out to investigate the probable effects of fish cage culture on benthic communities as a pollution and stress indicator and to evaluate the biotic health condition using BOPA index, in Ghazale Creek (Khowre-Mussa - Persian Gulf). Monthly sampling from 4 stations was carried out from June 2007 to March 2008 (during nine months). Stations were selected from unde...
One motivation for our study concerns an environmental application that regards the identification of pollution sources in surface water: in a river, for example, the introduction of organic matter which could have as origin city sewages, industrial wastes,... usually drops to too low the level of the dissolved oxygen in the water. Since the lack of dissolved oxygen represents a serious threat ...
Abstract Today, the pollution of Rangeland soils by various destructive pollutants has become one of the human-environmental problems. Lacking proper management of organic matter discharge can also increase the concentration of salts, heavy metals, and pathogenic microorganisms. In this study, to investigate and measure the concentration of toxic elements, 128 soil samples of Chadegan region w...
The Momoge Nature Reserve is the research object of this study. Through field sampling, laboratory experiments and analysis, the contents, distribution characteristics, source identification, pollution levels and risk levels of polycyclic aromatic hydrocarbons (PAHs) in wetland soils were studied. The results show that the sum content of 16 types of PAHs (Σ16 PAH) in the wetland soil was within...
Conventional agriculture has improved in crop yield but at large costs to the environment, particularly off-site pollution from mineral N fertilizers. In response to environmental concerns, organic agriculture has become an increasingly popular option. One component of organic agriculture that remains in question is whether it can reduce agricultural N losses to groundwater and the atmosphere r...
Objective-driven DEVS modeling using OPI matrix for performance evaluation of discrete event systems
DEVS (Discrete Event Systems Specification) models are widely employed for simulation-based performance evaluation of discrete event systems. Performance modeling of such a system requires a pruning of a set of components, or objects, within the system in its subset which are eventually transformed into simulation models. Such modeling is objective-driven in that simulation models may be abstra...
The aim of the study was to assess the level of air pollution by volatile organic compounds (VOCs) in a pig fattening house and in its vicinity. Air samples for chromatographic analysis were taken in the fattening house and in the vicinity of the farm. The air quality study shows that the level of organic gaseous pollutants was twice as high in the fattening house as in the atmospheric air. Alm...
Objective: Metal concentrations in 53 soil samples of Shahr-e-Babak were determined. Methods: Assessment of enrichment factor and geo-accumulation index revealed higher degree of contamination of Cd, Pb, and Cu in soil samples. Moreover, results of metal fractionation study revealed high amount of Cd and Pb are associated in weakly bounds may lead to environmental risk of these metals. Result...
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