نتایج جستجو برای: industrial activities lead to an increase in heavy metal burden in rivers. sediment and algae (spirogyra sp.) samples were collected from the shoor river to investigate their heavy metal concentrations. dry and ashed samples of algae and sediment were digested using concentrated nitric acid. heavy metals (as

تعداد نتایج: 27352562  

Journal: :محیط زیست طبیعی 0
مریم زارع دانشجوی کارشناسی ارشد، گروه محیط زیست، دانشکده منابع طبیعی دانشگاه تهران، ایران امیرحسین حمیدیان استادیار گروه محیط زیست، دانشکده منابع طبیعی دانشگاه تهران، ایران هادی پورباقر استادیار گروه شیلات، دانشکده منابع طبیعی دانشگاه تهران، ایران سهراب اشرفی استادیار گروه محیط زیست، دانشکده منابع طبیعی دانشگاه تهران، ایران لیلا وزیری دانشجوی کارشناسی، گروه محیط زیست، دانشکده منابع طبیعی دانشگاه تهران، ایران

industrial activities lead to an increase in heavy metal burden in rivers. sediment and algae (spirogyra sp.) samples were collected from the shoor river to investigate their heavy metal concentrations. dry and ashed samples of algae and sediment were digested using concentrated nitric acid. heavy metals (as, fe, zn and cr) concentration measured using an icp-oes instrument (perkinelmer, usa). ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1392

gol-e-gohar iron ore mine of sirjan in southern part of iran is a large open pit that operates below the groundwater table and during mining operation, dewatering is required to prevent operation processes from flooding. current operation is going on by digging wells in or out of the pit and pumping to prevent flooding. as a result of the former dewatering operation a vast deep cone of depressi...

Journal: :محیط زیست طبیعی 0
مریم زارع رشکوئیه کارشناس ارشد گروه محیط زیست، دانشکدة منابع طبیعی، دانشگاه تهران امیرحسین حمیدیان استادیار گروه محیط زیست، دانشکده منابع طبیعی، دانشگاه تهران هادی پورباقر استادیار گروه شیلات، دانشکده منابع طبیعی، دانشگاه تهران سهراب اشرفی استادیار گروه محیط زیست، دانشکده منابع طبیعی، دانشگاه تهران

increasing industrial activities lead to entrance of different pollutants into the environment, especially water resources. because of their persistency and non-biodegradation, metals can pose a threat to health of human and other organisms. sediment, fish (lucioperca stizostedion and cyprinus carpio), and common reed (phragmites australis) samples were collected from sattarkhan dam for investi...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد شاهرود - دانشکده پزشکی 1390

nitric oxide (no) is a small molecule synthesized by most of mammalian cells with diverse biological activities including vasodilatation, host defense and wound healing. impaired wound healing is a common occurrence among diabetics and patients receiving glucocorticoid therapy. on the other hand the application of laser in biomedical area have been increased. thus, the current studies were desi...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده ادبیات و علوم انسانی 1392

abstract the first purpose of this study was to investigate the effect of consciousness-raising (c-r) activities on learning grammatical structures (simple present tense in this case) by iranian guidance school efl learners. the second one was to investigate the effect of gender on learning the simple present tense through c-r activities and tasks. finally, this study aimed to investigate the ...

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

abstract this study is carried out to determine the chemical composition in the three vegetative stages of the haloxylon sp., degradation parameters, with adding naoh and ca(oh2 ). for this purpose, in may and october and january 2010 enough some haloxylon sp. of the ammary area was prepared. crude protein and ash percentage are decrease, neutral detergent fiber percentage with pragress stage ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده کشاورزی و منابع طبیعی 1392

the aim of the present study was to determine the in?uence of presence or absence of corpus luteum (cl) on hormonal and metabolites composition of follicular ?uid (ff) harvested from different sized follicles and its relationship with blood serum concentrations in sanjabi ewes. ovaries and blood samples were collected from 60 clinically healthy adult ewes (sanjabi breed) 1–3 years of age in dio...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده علوم انسانی 1389

rivers and runoff have always been of interest to human beings. in order to make use of the proper water resources, human societies, industrial and agricultural centers, etc. have usually been established near rivers. as the time goes on, these societies developed, and therefore water resources were extracted more and more. consequently, conditions of water quality of the rivers experienced rap...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سمنان - دانشکده مهندسی موادو متالورژی 1393

the aim of this paper is eliminating cr(vi) by natural hap. hap is a inexpensive material which is used from bovine critical bone ash in order to remove heavy metal ions like cr(vi). some experiments in different ph are performed (ph=2,3,7). maximum adsorption was appeared at ph=2, dosage=0.3 gr, c0=10 mg/l. cr(vi) removal depends on ph value and initial amount of cr(vi) result of experiments w...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شاهد - دانشکده علوم پایه 1388

introduction acetic acid bacteria are large group of obligate aerobic gram negative bacteria with the ability to oxidize ethanol to acetic acid (1). they are widely distributed in natural habitats and classified in family acetobacteraceae. members of this family are useful in industrial production of vinegar(2). acetic acid bacteria (aab) can use substrates as glucose, ethanol, lactate or glyc...

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