نتایج جستجو برای: controlling the sound pollution inside the building 5

تعداد نتایج: 16336463  

Journal: :تحقیقات نظام سلامت 0
فرهاد فروهرمجد استادیار، گروه مهندسی بهداشت حرفه ای، دانشکده بهداشت، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران زهرا محمدی دانشجوی کارشناسی ارشد، کمیته تحقیقات دانشجویی، گروه مهندسی بهداشت حرفه ای، دانشکده بهداشت، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران

background: sound is one of the most important factors threatening workers’ health. the most efficient and practical method for controlling noise pollution is the use of sound-absorbing materials. impedance tube with two microphones is used to determine the sound absorption coefficients and should be tested periodically for accuracy and efficiency. the purpose of present study was assessing the...

پایان نامه :0 1374

having conducted the experiment and analysed the data, the researcher computed the groups mean scores and variances for the test relating to the research question. as the final atep, a t-test was conodonted for the hypothesis. as noted earlier, the significance level was determined at .05 and .01 respectively. the observed t-value was higher than the critical t-value at. 5 and .01 levels. conse...

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

in the area of vocabulary teaching and learning although much research has been done, only some of it has led to effective techniques of vocabulary teaching and many language learners still have problem learning vocabulary. the urge behind this study was to investigate three methods of teaching words. the first one was teaching words in context based on a traditional method of teaching that is,...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1389

fluorescence chemical sensors for the highly sensitive and selective determination of pb2+ , hg2+, co2+ and fe3+ ions in aqueous solutions are described. the ion sensing system was prepared by incorporating lipophilic ligand (l) as a neutral ion-selective fluoroionophore in the plasticized pvc membrane containing sodium tetraphenylborate or potasium tetrakis (p-chlorophenyl) borate as a liphoph...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز - دانشکده علوم طبیعی 1391

in recent years many researchers have been focused on interaction of small molecules with dna. dna is generally the primary intracellular of anticancer drugs, so the interaction between small molecules and dna can cause dna damage in cancer cells, blocking the division of cancer cells and resulting in cell death. the flavonoids are a large group of polyphenolic natural products that are widely ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده علوم انسانی 1388

abstract the present thesis studies different question sentences in persian and russian languages comparatively. sentence is a syntactic unit that matches a lot of dimensions together. sentence includes syntactic structure definite meaning & concept and different applied demotions. in applied, question and imperative sentences based on speakers aim. predicative sentences state a kind of info...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز - دانشکده ادبیات و زبانهای خارجی 1393

for several years, researchers in familiarity of efl teachers with post-method and its role in second and foreign language learners’ productions have pointed out that the opportunity to plan for a task generally develops language learners’ development (ellis, 2005). it is important to mention that the critical varies in language teaching was shown is the disappearances of the concept of method ...

پایان نامه :موسسه آموزش عالی غیردولتی رودکی تنکابن - دانشکده ادبیات و زبانهای خارجی 1383

abstract this study examined the relationship between noticing pronunciation and the improvement pronunciation by administering a 50 item story, as proficiency- test in order to investigate the effectiveness of noticing pronunciation on the improvement of pronunciation. accordingly 60 qualified students were selected and assigned to the two groups of experimental and control randomly, each gr...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - پژوهشکده ادبیات 1391

the major purpose of this study was to develop the translation teacher competency test (ttct) and examine its construct and predictive validity. the present study was conducted in two phases: a qualitative phase as well as a quantitative phase. in the first phase of the study, the author attempted to find out the major areas of competency required for an academic translation teacher. the second...

پایان نامه :وزارت بهداشت، درمان و آموزش پزشکی - دانشگاه علوم پزشکی و خدمات بهداشتی درمانی مشهد - دانشکده دندانپزشکی 1390

objective: the objective of this study was to investigate the invitro fluoride release of four new self-adhesive resin cements; set (sdi, australia), breeze (pentron, usa), embrace wetbond (pulpdent, usa), g-cem (gc, japan) and to assess the bonding performance of these self-adhesive resin cements for bonding of orthodontic brackets. materials and methods: for fluoride release experiment, six ...

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