نتایج جستجو برای: water pollution and ecological changes regarding these mentioned problems

تعداد نتایج: 17126011  

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

increasing academic and professional language demands around the world are not a deniable fact. the purpose of this study was to investigate english language needs and communication needs of the chemistry students at master and ph.d. levels at the iranian universities. in this research, different methods were used including un-structured interview, structured interview, and two sets of question...

This study aims to identify and determine species diversity and richness of the Gastropods of intertidal zone of Bushehr seaport coastal field and assess ecological status of the area using Welch index. Sampling was carried out at 6 stations in Bushehr seaport in winter and summer seasons during 2013-2014. Sampling bed sediments was done three times in each station and Gastropod samples were co...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - پژوهشکده ادبیات 1393

1.0 overview it seems that grammar plays a crucial role in the area of second and foreign language learning and widely has been acknowledged in grammar research. in other words, teaching grammar is an issue which has attracted much attention to itself, and a lot of teachers argue about the existence of grammar in language teaching and learning. this issue will remind us a famous sentence f...

Journal: :jundishapur journal of health sciences 0
seyyedeh marzieh moosavian khouzestan science and research branch, islamic azad university, ahvaz, ir iran; khouzestan science and research branch, islamic azad university, ahvaz, ir iran. tel: +98-9166028053, seyyed mohammad baghernabavi department of environmental science, graduate school of the environment, science and research branch ,islamic azad university, ahvaz, ir iran elahe zallaghi young researchers club, khouzestan science and research branch, islamic azad university, ahvaz, ir iran maryam mohammadi rouzbahani department of environmental science, graduate school of the environment, science and research branch ,islamic azad university, ahvaz, ir iran elham hosseini panah khouzestan science and research branch, islamic azad university, ahvaz, ir iran moloud dashtestani khouzestan science and research branch, islamic azad university, ahvaz, ir iran; department of environmental science, graduate school of the environment, science and research branch ,islamic azad university, ahvaz, ir iran

background bivalves have been used to study pollution level caused by heavy metals due to their biological characteristics. bahrakan region includes bahrakansar, hendijan, norouz and soroush oil fields, and current information regarding sea management, especially from the protective aspect is very little. objectives this study aimed to assess region pollution with heavy metals. for this purpose...

The pollution caused by the presence of heavy metals in the air, water and soil is one of the world's ecological problems. In this study, the effect of different concentrations of calcium on the absorption and accumulation of Cd and Zn in M. flavida from Brassicacea was studied. For this purpose, concentrations of 100, 400 and 1600 µM calcium and 1, 5 and 10 µM Cd and 10, 20 and 40 ...

Mortazavi, Samar, Raheli namin, Behnaz, Shaddel, Maryam, Tayebi, Lima,

Background: Water contamination of heavy metals is one of the major threats to human health and food chain. In this study, concentration of heavy metals of lead, chromium, copper and zinc in sediment was measured in order to assess their ecological effects and their risk. Methods: To determine the concentration of metals, 12 stations were selected along the river and 3 samples from the sedi...

2011
Timothy M. Waring Peter J. Richerson

The major environmental problems of the twentyfirst century, including climate change, water scarcity, pollution and resource exhaustion, represent a new category of crisis and highlight the desperate need for an integrated science of socioecological phenomena. To help establish the foundations of such a science, we explore three traditions of mathematical theory: the Lotka–Volterra interaction...

Journal: :Journal of environmental quality 2014
P C Roebeling J Rocha J P Nunes T Fidélis H Alves S Fonseca

Coastal aquatic ecosystems are increasingly affected by diffuse source nutrient water pollution from agricultural activities in coastal catchments, even though these ecosystems are important from a social, environmental and economic perspective. To warrant sustainable economic development of coastal regions, we need to balance marginal costs from coastal catchment water pollution abatement and ...

Journal: :international journal of advanced biological and biomedical research 2014
mosayeb baghaie mohamad chizari

objective: the main purpose of this research is review of principles, concepts, problems and solutions of soil ethic. methods: in this research by descriptive method and delphi technique was used for identifying soil ethical concepts, soil ethical principles, problems and difficulties of soil ethics in iran and al around the world and suggestions for improvement of soil ethics in iran. the popu...

Due to the lack of water quality of resourses in country, exact review of available water resources quality, especially in terms of heavy elements (heavy metals) has a particular importance. Due to industrial towns 1 and 2 of Yasuj city and also Yasuj wastewater treatment, surveying environmental harmful effects of heavy metals on this river is very important. To investigate the changes of heav...

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