نتایج جستجو برای: catalytic

تعداد نتایج: 79040  

In the Boudouard reaction, where CO2 is reacted with carbon (char) to produce CO, very high temperatures are required to shift the equilibrium towards CO production. This endothermic reaction is inherently slow and catalytic species are effective to speed up the reaction rate at temperatures below 900 °C. In this study, the catalytic effect of some alkali (K, Na), alkaline earth (Ca) and transi...

ژورنال: مواد پرانرژی 2012
آقازیارتی, محمود, تاشک, امین, عبداللهیان پور, بهنام , فرمهینی فراهانی, مجتبی,

  In this research, Polyisobutylene was produced via batch direct polymerization of isobutylene in a 1 liter reactor at low temperature. Various catalytic systems were investigated to produce desired polymer. The results showed that AlCl3 /TiCl4 catalytic system is the best catalytic system to produce desired Polyisobutylene. In addition, effects of other important parameters such as temperatur...

Ali Allahresani Heidar Raissi Mohammad Nasseri,

Nano-graphene oxide was synthesized by the oxidation of graphite powders. The structural nature of the nano-graphene oxide was characterized by a variety of techniques including XRD, TEM, FT-IR and UV/Vis. The functional groups on its basal planes and edges of nano-grahene oxide play important role in catalytic activity. The catalytic activity of nano-graphene oxide was investigated on Crossed-...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2004
naser saghatoleslami javad sargolzaei seyyed mahmood mousavi

hydrogen is an unusual substance in that its molecule exists in two forms, known as ortho and para, with markedly different properties. energy level of the ortho molecule is higher than para, therefore, the latter is employed for industrial purposes. consequently, for a high  conversion of  ortho to para hydrogen a catalyst reactor must be employed.  therefore, one of  the main objectives of th...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2013
mohammad reza ehsani ali reza safadoost reza avazzadeh azita barkhordari

mercaptans are commonly present in petroleum products. their foul odor and highly corrosive nature make them the most undesirable sulfur compounds so they should be removed because of environmental issues. merox process is used for oxidation of mercaptans to disulfide using air in the presence of alkaline solution and merox catalyst. in this paper, due to lack of information about the kinetic o...

Journal: :تحقیقات نظام سلامت 0
مجید کرمانی دانشیار، گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی ایران، تهران، ایران فرشاد بهرامی اصل دانشجوی دکتری، گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی همدان، همدان، ایران علی اسرافیلی استادیار، گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی ایران، تهران، ایران مهدی فرزادکیا استاد، گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی ایران، تهران، ایران سهیلا سلحشور آرین کمیته تحقیقات دانشجویی، دانشگاه علوم پزشکی ارومیه، ارومیه، ایران

background : metronidazole, as one of the most widely used antibiotics in the world, in addition to various benefits, has significant adverse effects on the environment and animals. the catalytic ozonation process is one of the most successful methods for antibiotics removal. however, it should be noted that this process, like other oxidation processes, has some byproducts that can be toxic in ...

Journal: :journal of nanostructures 2015
g. nabiyouni d. ghanbari j. ghasemi a. yousofnejad

in this work firstly mgfe2o4 nanoparticles were synthesized via a microwave-assisted method. the product was calcinated at 900 ºc for 2h. at the second step zinc oxide shell was synthesized on the ferrite under ultrasonic waves. properties of the product were examined by x-ray diffraction pattern (xrd), scanning electron microscope (sem) and fourier transform infrared (ft-ir) spectroscopy. vibr...

TiO2 nanoparticles/melamine Tri sulfonic acid (MTSA) supported on silica gel as an efficient catalytic system for simple, one pot, solvent-free and environmentally benign process for synthesis of dihydropyrimidines via Biginelli reaction at 110 °C is described. It was found that the catalyst is reusable and exhibited remarkable activity. The catalyst can be easily separated and reused several t...

forough cheldavi

TiO2 nanoparticles/melamine Tri sulfonic acid (MTSA) supported on silica gel as an efficient catalytic system for simple, one pot, solvent-free and environmentally benign process for synthesis of dihydropyrimidines via Biginelli reaction at 110 °C is described. It was found that the catalyst is reusable and exhibited remarkable activity. The catalyst can be easily separated and reuse...

Three high-silica mordenite zeolites differing in SiO440, ratio were prepared by direct synthesis without using any template. The products Si02/A120, ratio is influenced by the starting gel composition. This ratio is increased upon ion-exchange with NH,Cl and subsequent calcination to prepare protonic mordenite. The protonic mordenites with Si02/A1203ra tios of 14.6,29.2 and 34.6 were chara...

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