نتایج جستجو برای: mechanical stability

تعداد نتایج: 524892  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده منابع طبیعی 1391

in this study, the effects of oleothermal modification on physical and mechanical peroperties of fir wood (abeis sp.) blocks were examined. at first, some blocks of fir wood with 5 × 20 × 120 cm dimensions were prepared. the blocks were treated in soybean oil. the effects of 3 factors such as treatments temperature (180and 200 °c), holding time (12 and 15 h) and initial moisture content of wood...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی اصفهان - دانشکده شیمی 1389

in this project, some new polyaspartimides, (pas)s, have been synthesized form michael addition reaction between new synthetic bismaleimide (bmi) and some aromatic diamines. a characteristic property of this polyaspartimides is a pendent carboxylic group, which introduced to these polymers from new bismaleimide. bismaleimides (bmi) is one of the interesting compounds, which can be self-polymeri...

Journal: :journal of modern processes in manufacturing and production 2015
mohammad goodarzi

in this paper, a robust pid control scheme is proposed for micro-electro-mechanical-systems(mems) optical switches. the proposed approach is designed in a way which solves twochallenging and important problems. the first one is successful reference tracking and the second ismitigating the system nonlinearities. the overall system composed of nonlinear mems dynamicsand the pid controller is prov...

Journal: :iranian journal of medical physics 0
a. khoshbin khoshnazar assistant professor, medical physics dept., golestan university of medical sciences, golestan, iran m. t. bahreyni toosi professor, medical physics research center, bu-ali research institute, mashhad university of medical sciences, mashhad, iran. a. hashemian assistant professor, medical physics research center, bu-ali research institute, mashhad university of medical sciences, mashhad, iran. m. h. bahreyni toosi professor, medical physics research center, bu-ali research institute, mashhad university of medical sciences, mashhad, iran. r. salek assistant professor, radiation oncology dept., imam reza hospital, mashhad university of medical sciences, mashhad, iran

introduction:  stereotactic  radiosurgery  is  a  technique  for  the  treatment  of  intracranial  lesions  with  highly  collimated  x-ray  beam.  linac-based  radiosurgery  is  currently  performed  by  two  techniques:  couch or pedestal mounted. in the first technique, a device is required to affix patient's head to a couch  and  moreover  to  translate  it  accurately.  structure  of...

Journal: :جنگل و فرآورده های چوب 0
علیرضا سوخته سرائی دانشگاه تهران سحاب حجازی دانشگاه تهران- دکترا لعیا جمالی راد دانشگاه گنبد کاووس محمد احمدی دانشگاه تهران سید بهنام حسینی دانشگاه تهران

in this study , the physical and mechanical properties of polypropylene composites reinforced with bagasse alkaline-sulfite-anthraquinone, soda-anthraqouinone, monoethanolamine-anthraquinone chemical pulps and mechanical pulp (cmp) known as pulp-plastic compostes (ppc) were investigated and the results were compared among ppcs and with polypropylene composites reinforced with bagasse flour know...

Journal: :The Journal of chemical physics 2009
A M Gabovich Mai Suan Li

A number of experiments and experimentally based simulations showed that beta-proteins are mechanically more stable than alpha-proteins. However, the theory that might explain this evidence is still lacking. In this paper we have developed a simple elastic theory, which allows to estimate critical forces for stretching both kinds of proteins. It has been shown that unfolding of beta-proteins do...

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

abstract amino acids are building blocks of proteins, and play a vital role in living beings existence and their functionality. the interaction of these compounds with metal ions is of great importance to biochemists, and chemists, because their functions can be utilized as a model in understanding enzymes mechanism for transport of metal ions to tissues. among twenty essential amino acids w...

Journal: Nanomedicine Journal 2018

Objective(s): One of the main constraints of collagen hydrogel scaffolds for using in tissue engineering is mechanical weakness. Plastic compression (PC) is a physical method to overcome the mechanical limitation of collagen hydrogel. Materials and Methods: In this study, the effects of pH on mechanical and biological properties of PC hydrogels were investigated. Collagen hydrogels were fabrica...

ژورنال: مواد پرانرژی 2013

In order to increasing of hydroxy functionality of HTPB an in-situ nitroxide mediated polymerization (NMP) of 1,3-butadiene was carried out in presence of TEPA as a polyfunctional nitroxide precursor. The multi-modal molar mass distribution of the product was elucidated by reductive hydrolyzation of the oligomeric product. The new polyfunctional hydroxyl-terminated polybutadiene (PFHTPB) was c...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید