نتایج جستجو برای: 6963 and 7653 μgg dry weights respectively according to determine geoaccumulation index igeo

تعداد نتایج: 18332777  

Background and purpose: Lead is a heavy metal, which has been replaced by calcium hydroxyapatite in tooth enamel. It is considered as an index of pollution assessment. Zanjan province is potential area for lead element accumulation. This study aimed at comparing the amount of lead in human deciduous and permanent teeth in order to evaluate and determine the risk of lead pollution in urban and r...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده کشاورزی 1391

بررسی تنوع ژنتیکی ژنوتیپ‏های بومی پیاز ایرانی در مقایسه با انواع خارجی چکیده: برنامه های اصلاحی گیاهان بر اساس تنوع و انتخاب صفات برتر کمی و کیفی صورت می گیرد. لذا، ارزیابی تنوع ژنتیکی، اولین مرحله در برنامه های اصلاحی است. در این راستا، استفاده از روش های جدید مطالعه‏ی تنوع ژنتیکی ضروری به نظر می رسد. در این بررسی تعیین تنوع ژنتیکی سیزده ژنوتیپ پیاز ایرانی در مقایسه با دو ژنوتیپ خارجی با است...

Journal: :iranian journal of environmental sciences 0
s. m. didar-ul islam department of environmental sciences, jahangirnagar university, dhaka-1342, bangladesh mohammad amir hossain bhuiyan department of environmental sciences, jahangirnagar university, dhaka-1342, bangladesh tanjena rume department of geological sciences, jahangirnagar university, dhaka-1342, bangladesh mohammad mohinuzzaman department of environmental science and disaster management, noakhali science and technology university, sonapur-3814, bangladesh

the contamination of riverbed sediments by heavy metals has assumedserious problems due to their toxicity and accumulative behavior. the present studyinvestigated the concentrations of heavy metals from the bottom sediments of shitalakhyariver to understand the level of contamination and their distribution. the averageconcentrations of heavy metals al, k, ca, mg, fe, as, cu, co, cr, and zn are ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت معلم تهران - دانشکده علوم 1370

determination of uranium in natural water and complex solutions using ion exchange chromatography: a combined procedure using ion exchange chromatography and uv-vis spectrophotometry techniques has been developed to measure uranum in natural water and complex solutions. after conditicing , one hundred milli liters of sample solutions have been passed through an ion exchange column,pachked with ...

Journal: :Water 2023

Constructed wetlands are an affordable and reliable green alternative to conventional mechanical systems for treating domestic sewage. This study investigates the potential of 14 tropical wetland plant species removing heavy metals from sewage through bioconcentration factor (BCF), translocation (TF), enrichment (EF), geoaccumulation index (Igeo) using batch mesocosm studies. Plants with BCF &g...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده ادبیات و زبانهای خارجی 1390

august wilson is undoubtedly one of the rare black playwrights whose works have attracted streams of attention and worldwide audience. the present study aims at analyzing fences and piano lesson which are two of the most successful plays in his pittsburgh cycle from the perspective of michel foucault’s theories and ideas. studying these two plays from foucault’s perspective opens new windows in...

Journal: :Minerals 2023

With the rapid development of economy, heavy metal soil pollution causes ecosystem deterioration and raises serious concerns. Topsoil samples (n = 205) were collected to investigate characteristics, risk levels, sources metals in topsoil eastern Tibet. Heavy contents, such as As, Hg, Pb, Cr, Mn, Mo, Ni, Cu, Zn, Cd, tested, potential analyzed using correlational principal component analysis. The...

پایان نامه :دانشگاه تربیت معلم - تهران - دانشکده ادبیات و زبانهای خارجی 1390

the frame semantic theory is a nascent approach in the area of translation studies which goes beyond the linguistic barriers and helps us to incorporate cognitive and cultural factors to the study of translation. based on rojos analytical model (2002b), which centered in the frames or knowledge structures activated in the text, the present research explores the various translation problems that...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس 1390

abstract:‎ literature is said beautiful words of poetry or prose that excites reader’s or listener’s feel. certainly, to ‎be effective, such a text should have certain characteristics. the four elements of the literature: thought, ‎imagination, emotion and style make a text to be literary and effective. emotion and imagination are ‎specific elements of literary texts, while thought and style a...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه یزد 1388

plagiarism in esl/efl learning contexts has been established as a dynamic and multi-layered phenomenon and has become a topic engaging many researchers in a heated debate in recent years. comparisons of student-generated texts with their source texts have shown that students rely on source texts in their writings and copying is a major strategy used by both l1 and l2 writers. in our country a...

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