نتایج جستجو برای: the surface area decreases x
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Sol-gel derived sulfur modified and pure ZnO nanorod were prepared using zinc chloride and thiocarbamide as raw materials. Prepared nanorods were characterized by means of X-ray diffraction (XRD), thermogravimetry- differential scanning calorimetry (TG–DSC), UV- Vis absorption spectroscopy, Brunauer Emmett Teller (BET) specific surface area and Barrett Joyner Halenda (BJH) pore size distributio...
A series of x(Co, Mn)/TiO2 catalysts (x=2–12wt.%) containing 25%Co and 75%Mn were prepared by the co-impregnation method. All prepared catalysts have been tested in Fischer-Tropsch synthesis for production of C2-C4 olefins. It was found that the catalyst containing 8wt.%(Co,Mn)/TiO2 is an optimal catalyst for production of C...
Abstract: In this research plasma nitriding of pure aluminium and effect of iron elemental alloy on the formation and growth of aluminium nitride was investigated. Also corrosion properties of formed AlN were investigated. After preparation, the samples were plasma nitrided at 550oC, for 6, 9 and 12 h and a gas mixture of 25%H2-75%N2. The microstructure and phases analysis were investigated usi...
One of the challenges in the printing industry is the presence of extra lines in printing design. This problem is due to the improper surface roughness of carved cylinders. This research endeavors to specify and optimize the effective parameters on the surface roughness of chrome coated printing cylinders in the finishing process that is done using a finish star machine. Investigated parameters...
Clay mineralogy of paleosols provides more information about Quaternary climatic changes and paleoenvironmental conditions. Clay minerals of an alluvial fan in eastern Isfahan were studied, using x-ray diffraction analysis. Studied paleosols are located on old Qf1 and Qf2 geomorphic surfaces. Qf1 geomorphic surface is older and topographically higher than Qf2. The results of clay mineralogy sho...
section{introduction} the concept of {sl cartan geometry} appeared at the beginning of the twentieth century, when {e}lie cartan was working on the so-called {sl equivalence problem}, the aim of which is to determine whether two given geometric structures can be mapped bijectively onto each other by some diffeomorphism. this problem can be considered in many different contexts, such as ...
in this work, we report a new well dispersed molybdenum complex attached through the mediation of aminopropylsilyl groups on the surface of multi-walled carbon nanotubes (mwcnts). the prepared hybrid nanomaterial was characterized with different physicochemical methods such as fourier transform infrared and atomic absorption spectroscopies, transmission electron microscopy, energy-dispersive x-...
sol–gel auto-combustion is a unique combination of the combustion and the chemical gelation processes. in this work, nanosize (d) powders with compositions of znfe2o4 were synthesized by sol–gel combustion method. the puffy, porous brown powders as-combusted was calcined at the temperature of 750–1000◦c for 4 h. these powders are characterized by x-ray diffraction and scanning electron microsco...
the present dissertation aims to investigate four-word lexical bundles in applied linguistics research articles by iranian and internationally-published writers. the aims of this study are two-fold: first of all, attempts have been made to create a comprehensive list of the most commonly used four-word lexical bundles categorized by their type and token frequency, their structural characteristi...
بررسی ارزش غذایی تاغ و عمل آوری آن با سود و آهک در مراحل مختلف رشدبا استفاده از روش کیسه های نایلونی
abstract this study is carried out to determine the chemical composition in the three vegetative stages of the haloxylon sp., degradation parameters, with adding naoh and ca(oh2 ). for this purpose, in may and october and january 2010 enough some haloxylon sp. of the ammary area was prepared. crude protein and ash percentage are decrease, neutral detergent fiber percentage with pragress stage ...
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