نتایج جستجو برای: the process efficiency declines continuously at higher ph values than 5

تعداد نتایج: 16716304  

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

testing plays a vital role in any language teaching program. it allows teachers and stakeholders, including program administrators, parents, admissions officers and prospective employers to be assured that the learners are progressing according to an accepted standard (douglas, 2010). the problems currently facing language testers have both practical and theoretical implications but the first i...

H. Dehghani Ashkezari H. Hoveidi H. Sid kalal M. Ashoor M.R. Almasian

The aim of this study was to degrade furfural by a new nanotube system. To degrade some organic pollutants as well as to reduce the amount of furfural which is a well-known pollutant in oil industry, the photocatalytic process along with ultraviolet (UV) irradiation may be employed. In this study, the UV/TiO2/Pd system in which the nanoparticles of palladium doped into the titanium dioxide was ...

A. Mehrizad P. Gharbani

This research evaluates the efficiency of nanosized ZnO in the catalytic ozonation of 4-chloro-2-nitrophenol and determines the effect of pH on heterogeneous catalytic ozonation. The combined use of ozone and ZnO catalyst leads to conversion of 98% 4-chloro-2-nitrophenol during 5 min. In addition, it was found that in ZnO catalytic ozonation, the degradation efficiency of 4-chloro-2-nitrophenol...

The current study aimed to examine the overall feasibility of the use of copper oxide nanoparticles (CuO-NPs) as a catalyst in ozonation process for the removal of benzene from aqueous solutions under experimental conditions. This experimental study was conducted on a laboratory scale reactor in a semi-batch mode. The effect of critical operating parameters such factors as pH, concentration of ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده ادبیات و علوم انسانی دکتر علی شریعتی 1389

the current study examined iranian undergraduate efl students’ willingness to communicate with regard to their vocabulary knowledge. in general, participants were somewhat willing to communicate in english. the total mean score of 730 university students’ perception of willing to communicate was 83.53 out of 135. results, regarding four parts of willingness to communicate, revealed that part...

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...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی 1389

this study was an attempt to investigate the effect of using c-test passages on the reading comprehension and incidental vocabulary learning of iranian intermediate efl learners. the participants were 60 male efl learners at kish mehr institute in garmsar. in fact, there were two groups, an experimental group and a comparison group with 30 students in each. the participants were pretested throu...

Journal: :محیط شناسی 0
سحر مکاری کارشناس ارشد مهندسی محیط زیست- آب و فاضلاب دانشکدۀ محیط زیست دانشگاه تهران غلامرضا نبی بیدهندی استاد گروه مهندسی محیط زیست دانشکدۀ محیط زیست دانشگاه تهران حسین نایب دانشجوی دکتری مهندسی محیط زیست- آب و فاضلاب، دانشکدۀ آب و محیط زیست دانشگاه شهید بهشتی

introduction     cadmium as one of the toxic heavy metal, because of harmful effects on health and the environment, has attracted a lot of attention. the main sources of cadmium emissions are the environment, the waste of electroplating, melting, alloyed manufacturing, pigments, plastics, batteries, extraction and refining processes. this metal easily accumulates in different machines of people...

Mesoporous pellet adsorbent developed from mixing at an appropriate ratio of natural clay, iron oxide, iron powder, and rice bran was used to investigate the optimization process of batch adsorption parameters for treating aqueous solution coexisting with arsenate and arsenite. Central composite design under response surface methodology was applied for optimizing and observing both individual a...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی 1390

insurers have in the past few decades faced longevity risks - the risk that annuitants survive more than expected - and therefore need a new approach to manage this new risk. in this dissertation we survey methods that hedge longevity risks. these methods use securitization to manage risk, so using modern financial and insurance pricing models, especially wang transform and actuarial concepts, ...

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