نتایج جستجو برای: heat of formation
تعداد نتایج: 21228260 فیلتر نتایج به سال:
the present study aimed at exploring cognitions of iranian english teachers within the context of english for academic purposes (eap). to this end, the cognitions of two groups of eap teachers with respect to their pedagogical content knowledge (pck) and their sense of professional identity (pi) were probed. two language teachers and two content instructors who had at least five years of eap te...
Need to high performance and low sensitivity explosives, led to wide spread research throughout the world. for access to modern and safe explosive materials. For this purpose high energy-density materials (HEDM) are good candidate. In this paper, has been reviewed the recent developments in the field of High energy density materials (HEDMs) and investigated their criteria and requirements. Also...
the quest for power has formed much of the world history especially in 20th and 21st centuries. oil (energy) particularly after industrial revolution has been a tool for conquest and power and has been transformed to a geopolitical issue. from a geopolitical point of view this has been the case for the last two centuries in central asia and caucasus. central asia and caucasus has always been...
چکیده ندارد.
dissimilar metals friction welding of austenitic–martensitic stainless steels is commonly used in order to manufacture engine valves in the automobile industry. in this study, x53crmnnin219 (austenitic stainless steel) and x45crsi93 (martensitic stainless steel) valve steel rods were welded by friction welding process. the welded joint was then heat treated at 760 0c for 60 min. mechanical prop...
nucleate pool boiling heat transfer coefficient have been experimentally measured on a horizontal rod heater for various liquid binary mixtures. measurements are based on more than three hundred data points on a wide range of concentrations and heat fluxes. in this investigation, it has been confirmed that the heat transfer coefficient in boiling solutions are regularly less than those in pure ...
Industrial demands for more compact heat exchangers are a motivation to find new technology features. Electrohydrodynamics (EHD) is introduced as a promising phenomenon for heat transfer enhancement mechanisms. Similar to any new technology, EHD has not been understood completely yet and requires more fundamental studies. In boiling phase change phenomena, nucleation is the dominant mechanism i...
in this thesis, a new optically active poly(amide-imide) (pai) was synthesized by the indirect polycondensation reaction of the l-phenylalanine based diacid chloride and 4,4?-diaminodiphenylether in the presence of triethylamine in n-methyl-2-pyrrolidone. the formation of pai was confirmed by ftir, 1h nmr and elemental analysis. in next step, the surface of titanium dioxide (tio2) nanoparticles...
in this investigation, fluor-hydroxyapatite (fha) film was deposited on a titanium substrate by sol-gel method. triethyl phosphite, ammonium fluoride and calcium nitrate in ethanol solutions were used respectively as p, f and ca precursors. typical apatite structures were obtained for all coatings after dipping and subsequent heat treatment at 550, 700 and 800 ºc, the coating layers were invest...
Early heat waves are extreme events that cause heavy losses in plant and animal life and cause many social and economic problems for communities. The purpose of this study was to identify synoptic patterns and statistical analysis of preterm heat waves in northwestern Iran. To do this, the maximum daily temperature data of March 14th was used for fourteen synoptic stations in the northwest of t...
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