نتایج جستجو برای: based on immersion method three treating nano

تعداد نتایج: 10172340  

Journal: :journal of dental biomaterials 0
m. ferooz melbourne dental school, the university of melbourne, victoria, australia f. basri student research committee, shiraz dental school, shiraz university of medical sciences, shiraz, iran k. negahdari student research committee, shiraz dental school, shiraz university of medical sciences, shiraz, iran r. bagheri department of dental materials and biomaterials research centre, school of dentistry, shiraz university of medical sciences, shiraz, iran

statement of problem: tooth-coloured restorative materials are brittle with the major shortcomings of sensitivity to flaws and defects. although various mechanical properties of resin composites have been studied, no fracture toughness test data for nano-hybrid composites under acidic condition for a long period of time has been published. objectives: to compare the fracture toughness (k ic ) o...

پایان نامه :0 1374

the aim of this study has been to find answers for the following questions: 1. what is the effect of immediate correction on students pronunciation errors? 2. what would be the effect of teaching the more rgular patterns of english pronunciation? 3. is there any significant difference between the two methods of dealing with pronuciation errore, i. e., correction and the teaching of the regular ...

IIn this work, cobalt-based alloy/ nano bioactive glass (NBG) composites with 10, 15 and 20 wt% NBG were prepared and their bioactivity after immersion in simulated body fluid (SBF) for 1 to 4 weeks was studied. The scanning electron microscopy images of two- step sintered composites revealed a relatively dense microstructure the density of which decreased with the increase in the NBG amount. M...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده مدیریت 1392

data envelopment analysis (dea) is a powerful tool for measuring relative efficiency of organizational units referred to as decision making units (dmus). in most cases dmus have network structures with internal linking activities. traditional dea models, however, consider dmus as black boxes with no regard to their linking activities and therefore do not provide decision makers with the reasons...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2009
Munetaka Oyama Shin-Ya Yamaguchi Jingdong Zhang

A seed-mediated growth method for surface modification was applied to the attachment of gold nanoparticles (AuNPs) to glassy carbon (GC) surfaces. By simply immersing a GC plate at first into a seed solution containing 4 nm Au nano-seed particles and then into a growth solution containing HAuCl(4), ascorbic acid and cetyltrimethyammonium bromide, AuNPs could be successfully attached to the GC s...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده علوم انسانی و اجتماعی 1389

today the image of a permanent skeletal space of cities affected by some forces or mechanisms is put in time with social-economic development and while imposes a new face and perspective to physical anatomy of cities, and prepares field to changes in content and social- economic structures of cities too. simultaneously with quitting villages in order to settle in cities by villagers, the phen...

پایان نامه :دانشگاه تربیت معلم - تهران - دانشکده علوم انسانی 1390

this study investigated the effects of manipulating the cognitive complexity of tasks along +/- few elements and the time limits on l2 learners writing performance. to conduct the study, 60 iranian efl learners with two levels of proficiency, low and high intermediate, were selected and assigned to three groups based on the time devoted to task completion. the participants performed both a simp...

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The aim of this study is to create TiO2 coating on the tile substrate using cell-gel and immersion method. Initially, TiO2 coating was prepared by sol gel method and then, deposition was performed in three stages with different immersion periods of 20, 40 and 60 s and finally, the samples were calcined at 450 °C. The phases and microstructural characteristics of the samples were analyzed using ...

2016
Anitha Rao

Aim: To compare the effect of four different polishing systems on color stability of two Nano composite resins immersed in four beverages (Coffee, Tea, Cola and Fanta). Methods: Eighty disc shaped specimens of 10 mm diameter and 2 mm thickness were prepared for each of the two Nano composite resins (Tetric N Ceram; Estelite alpha). The specimens of each material were divided into four groups (n...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه ارومیه 1377

‏‎applications such as high definition viedeo reproduction, portable computers, wireless, and multimedia demand, and ever-increasing need for ligh-frequency high-resolution and low-power analog-to-digital converters. flash, two-step flash, and pipeline convertors are fast but consume large amount of power and require large area. to overcome these problems, successive approximation converter blo...

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