نتایج جستجو برای: Surface layer

تعداد نتایج: 867682  

پایان نامه :وزارت علوم، تحقیقات و فناوری - پژوهشگاه مواد و انرژی - پژوهشکده سرامیک 1392

thermal barrier coatings (tbcs) are used to provide thermal insulation to the hot section components of gas turbines in order to enhance the operating temperature and turbine efficiency. hot corrosion and thermal shocks are the main destructive factors in tbcs which comes as a result of oxygen and molten salt diffusion into the coating. in this thesis atmospheric plasma spraying was used to dep...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - پژوهشکده فنی و مهندسی 1388

asymmetric polyethersulfone (pes) microfiltration flat sheet membranes were composed by the phase inversion method (pim) and were used as supports. composite membranes were fabricated by coating silicone rubber as selective layer. effect of different concentrations of pes and pdms and different solvent such as nmp, dmf and dms effects as pes solvents and support thickness and different coagulat...

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

the methods which are used to analyze microstrip antennas, are divited into three categories: empirical methods, semi-empirical methods and full-wave analysis. empirical and semi-empirical methods are generally based on some fundamental simplifying assumptions about quality of surface current distribution and substrate thickness. thses simplificatioms cause low accuracy in field evaluation. ful...

Journal: :international journal of optics and photonics 0
zahra danesh kaftroudi department of engineering sciences, faculty of technology and engineering east of guilan, university of guilan, 44891-63157, rudsar-vajargah, iran esfandiar rajaei department of physics, university of guilan, 41335-1914, rasht, iran

in this study, we have theoretically investigated the effect of electron stopper layer on internal temperature distribution of high performance vertical cavity surface-emitting laser emitting at 1305 nm.  simulation software pics3d, which self-consistently combines the 3d simulation of carrier transport, self-heating, gain computation and wave-guiding, was used. simulation results show that cha...

Journal: :international journal of advanced design and manufacturing technology 0
mohamadmehdi hemmasian manouchehr rad

this paper studied the mathematical method of flow with regard to two-phase boundary layer that created over the iced surface. based on experimental results, skin drag over the iced surface compared with this force that compute with slip condition. based on this results, for iced surface blasius equation solving at non-slip condition, can replace with solving the blasius equation with slip cond...

Journal: :journal of computational applied mechanics 0
seyed abdolkarim payambarpour school of mechanical engineering, college of engineering, university of tehran, tehran, iran hossein shokouhmand school of mechanical engineering, college of engineering, university of tehran, tehran, iran

heat and mass transfer, in this paper, is considered in one-row heat exchanger, that fins are hotter than air flow and water is added to fins. related governing equations are derived by analyzing a two-dimension model in a unique cell of a heat exchange. these equations are numerically solved by finite difference method. heat transfer and efficiency under partially wet surface are calculated by...

Journal: :journal of nanostructures 2013
m. ghorbanpour

the aim of this study is experimental assay of sensitivity and stability of a bimetallic silver/gold spr sensor chip. this chip utilizes the sensitivity of the silver and the stability of the gold. moreover, the silver layer (instead of usual cr or ti layer) was used as an adhesive intermediate layer between the gold layer and the glass substrate. the optimization of the gold/silver thickness u...

Journal: :international journal of nanoscience and nanotechnology 2011
r. azimirad m. kargarian o. akhavan a. z. moshfegh

electrical, structural and morphological properties of ni silicide films formed in ni(pt 4at.% )/si(100) and ni0.6si0.4(pt4at.% )/si(100) structures at various annealing temperatures ranging from 200 to 1000 oc were studied. the ni(pt) and ni0.6si0.4(pt) films with thickness of 15 and 25 nm were deposited by rf magnetron co-sputtering method, respectively.  the annealing process of the structur...

Journal: :international journal of advanced design and manufacturing technology 0
aliakbar lotfi saeed daneshmand saeed adib nazari

in this study, as for the re-casting, surface alloying and re-solidification layer of this alloys at the work piece level machining with wire electro discharge machining (wedm), changes of surface micro hardness with changes of operational parameters has been studied. therefore, study shows using surface alloying phenomena with the diffusion of wire material into the machined surface and select...

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

in this thesis protic and aprotic ammonium-based ionic liquids were synthesized and their surface tensions were measured in the range of 298-373k. the protics are alkyl ammonium-based ils with the carboxylate (formate, acetate, propionate) anion and aprotics are quaternary ammonium-based ils with bis(trifluoromethylsulfonyl)imide anion. capillary rise method was used for surface tension measure...

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