نتایج جستجو برای: mtbe concentrations and soil dosage of samples

تعداد نتایج: 24082462  

Journal: :Chemosphere 2009
Annemarie van Wezel Leo Puijker Cees Vink Ans Versteegh Pim de Voogt

The use of ETBE (ethyl-tert-butylether) as gasoline additive has recently grown rapidly. Contamination of aquatic systems is well documented for MTBE (methyl-tert-butylether), but less for other gasoline additives. Due to their mobility they may easily reach drinking water collection areas. Odour and flavour thresholds of MTBE are known to be low, but for ETBE and TAME (methyl-tert-amylether) h...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد یزد - دانشکده شیمی 1392

in this study, a simple, rapid and selective method was developed for the determination of dexamethasone. the proposed method is based on inhibitory effect of dexamethasone on the oxidation of orange-g by bromate in sulfuric acid media. the reaction was followed spectrophotometrically at 478.5 nm (?max). under optimum experimental conditions, (72.6 ?mol l-1 of orange-g, 0.76 mol l-1 of h2so4, 0...

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

چکیده توان بالقوه تجاری سلولازها و کاربردهای گوناگون آن ها در بسیاری از صنایع انگیزه ای قوی برای تحقیق در این زمینه طی چند دهه گذشته بوده است. با توجه به کاربردهای فراوان این آنزیم در صنایع غذایی? در این پژوهش تصمیم به جداسازی ریزسازواره های تولید کننده سلولاز از خاک درختان انار، انگور، خرمالو و گردو حیاط دانشکده کشاورزی تربیت مدرس، گرفته شد. در این بین خاک درخت خرمالو به دلیل دارا بودن تعداد ...

2013

D company The FROG-4000TM Portable GC System Weighing less than 5 pounds, the FROG4000TM (shown in Figure 1) is the smallest portable GC system on the market today. The FROGTM uses MEMS components and designer nanomaterials to deliver the same detection capabilities of a traditional bench top GC system but at a fraction of the cost and size. The FROG-4000TM is equipped with a purge-and-trap sys...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده زبانهای خارجی 1388

this study investigated the potential role of age in inductive and deductive grammar learning among iranian foreign language learners. the experimental population consisted of our randomly selected samples including two groups of children (with age of exposure to english within 8-13), and two groups of adults (with age of exposure to english within 11-13). thus, the comparison was between ch...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده منابع طبیعی و علوم دریایی 1388

this research was conducted in two protect and destroy region in the middle zagros, in illam province. in order to identification of ecological species group and evaluate density of regeneration, effect of many factors such as protection, vegetation, physiographic factors, physical and chemical properties of soil in study locations were studied. to achieve these purpose number of 54 plots using...

Journal: :Pakistan journal of biological sciences : PJBS 2007
Mohamed S Beltagi

The current investigation was conducted to report on the phytotoxicity of methyl tert-butyl ether (MTBE) to common bean (Phaseolus vulgaris L. cv. Nebraska) plants. The two-week-old potted plants were subjected to four weekly soil applications of aqueous MTBE concentrations (0, 1, 10, 25 and 50 ml L(-1)). The root growth, flower and pod development were more sensitive to MTBE treatments; while,...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه خلیج فارس - دانشکده مهندسی 1393

in civil engineering concrete is a material combined of hydraulic cement, sand, gravel and water. gravel and sand compose 60 to 70 percent of concrete. these aggregates support compression force of concrete. cement paste acts as glue to stick grain together. in bushehr factories producing aggregates do not operate according to astm standards, so that fineness modulus (fm) of the produced sands ...

Journal: :محیط شناسی 0
علی بریانی کارشناس ارشد مهندسی محیط زیست- منابع آب، گروه مهندسی محیط زیست، دانشکدۀ محیط زیست، دانشگاه تهران علیرضا پرداختی استادیار گروه مهندسی محیط زیست و رئیس آزمایشگاه دانشکدۀ محیط زیست، دانشگاه تهران مجتبی اردستانی دانشیار گروه مهندسی محیط زیست، دانشکدۀ محیط زیست، دانشگاه تهران سیما امینی کارشناس ارشد شیمی تجزیه و کارشناس مسئول آزمایشگاه دانشکدۀ محیط زیست، دانشگاه تهران

contaminated groundwater by gasoline spill is a worldwide environmental problem. gasoline contains methyl tert-butyl ether (mtbe) and benzene, which are the chemicals of concerns (cocs) among the gasoline components. mtbe is highly water soluble and has a low henry’s law constant and low soil adsorption co-efficient. therefore, mtbe can easily move through the soil and then accumulate, distribu...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه یزد - دانشکده علوم انسانی 1391

the rise and stublishment of safavid dynasty was depend on triangle of tasavof, tashayo and royalty, kings legitimized their power upon these. therefore for the understanding the functions of that period we must explore the role of this elements. although application and emphsise upon dignities such as; complete mentor (morshede kamel), deputy of absent imam (nayebe imame ghayeb), and god’s sha...

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