نتایج جستجو برای: wear of materials

تعداد نتایج: 21191106  

Journal: :Dental materials journal 2003
Yasushi Wakamatsu Kiyoshi Kakuta Hideo Ogura

A new wear testing system, which carries out toothbrush wear and simulated occlusal wear tests alternately, was developed. Differences in wear behavior among three modes of wears, combined wear, toothbrush wear and simulated occlusal wear, were investigated using polymethylmethacrylate (PMMA) and two commercial resin composites (Z100, APX). The area of the material loss after each test was meas...

پایان نامه :0 1371

the treatment of in completely formed pulpless teeth has presented considrable problems. these teeth have wide open apexes and the walls of the root canal diverge toward the apical tissues. mechanical preparation cannot be done in the normal manner beacause of the large initial size and the taper of apical part of the canal , a mechanical stop cannot be produced at the apex of the canal and , t...

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

in iran we already use laminate tubes only in cosmetics industry. laminate tube manufacturers via using the most modern technology of the world, faced with the laminate tube market being saturated in cosmetics industry for packaging the cosmetic creams and toothpaste. but considering the great food market and therefore laminate tube features such as beautiful packaging, ease of use for the fina...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز 1381

‏‎this study investigated the effect of prior knowledge on the listening comprehension performance of fl learners. twenty students, male and female, drawn from the two intact groups of the senior and junior english language and literature majors were chosen as the participants of this study . the two groups were then randomly assigned into the experimental and control group. the experimental gr...

Theoretical and experimental investigation of wear during coupling in internal gears coated with various polymeric coating materials was performed in this study. In the theoretical part of the study, Archards’ wear formulation was adapted to internal gears and wear behavior in various conditions was determined. Moreover, a fatigue and wear testing apparatus having similar working principle with...

پایان نامه :دانشگاه تربیت معلم - تهران - دانشکده ادبیات و علوم انسانی 1391

efl/esl textbooks have been regarded as essential language teaching materials with which the learners spend about 70 up to 90 percent of their class time. the important role they play and their vast use make them not only influential in learning the language but also in shaping values and attitudes. put it another way, textbooks socialize learners using their contents (i.e. texts, illustrations...

Journal: :journal of dentistry, tehran university of medical sciences 0
masoumeh hasani tabatabaei sedigheh sheikhzadeh hamidreza ghasemi monfared rad ahmad beygi hossein bagheri

objectives: several studies have assessed the characteristics and properties of silorane-based composites and adhesive systems. considering the extensive application of tooth-whitening agents, possible deteriorative effects of tooth bleaching agents on these restorative materials must be studied. the aim of this study was to evaluate the effect of an in-office carbamide peroxide-based tooth ble...

Journal: :Journal of Applied Mechanics 1978

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

the purpose of this study was to investigate how english language teachers in mashhad who teach students in the pre-university cycle perceived the impact of the efltee on their teaching. the target population was nearly all pre-university english language teachers in seven districts of mashhad in the scholastic year 2008/2009. a survey questionnaire which consisted of (36) likert type items, wa...

Journal: :Bulletin of the Japan Institute of Metals 1979

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