نتایج جستجو برای: deactivation

تعداد نتایج: 6711  

Catalyst activity and performance are the most important factors for selecting a catalyst in different processes. The Fischer-Tropsch synthesis is a very important synthesis that extensive action has been taken place to increase the activity of its catalysts in the recent century. Deactivation of the catalysts of the process is influenced by many factors, among which coking and sintering have c...

Journal: :journal of nanostructures 2014
e. esmaeili a. rashidi

in the present study, tin-promoted pd/mwnts nanocatalystwas synthesized via polyol technique for application in hydrogenation of high-concentrated acetylene feedstocks. tem images showed a restricted distribution of nanoparticles in the range of 3-5 nm. the results indicated that nanoparticles sizes were resistant to further catalyst deactivation. xrd patterns signified alloying between pd and ...

ژورنال: ابن سینا 2020
Golparvar, Mohsen, Izadi, Rasieh, Javadi, Sara,

Background: Depression and anxiety are variables that undermine adolescentschr('39') mental health. The aim of this study was to determine the effectiveness of family mode deactivation therapy, cognitive behavioral therapy, and acceptance-commitment therapy on depression and anxiety of adolescent girls. Materials and methods: The research method was quasi-experimental, and the research design ...

Journal: :علوم دامی ایران 0
حامد خلیل وند بهروزیار دانشجوی دکتری پردیس کشاورزی و منابع طبیعی دانشگاه تهران مهدی دهقان بنادکی استادیار پردیس کشاورزی و منابع طبیعی دانشگاه تهران کامران رضایزدی دانشیار پردیس کشاورزی و منابع طبیعی دانشگاه تهران

effects of condensed tannins (ct) on crude protein availability in sainfoin hay was investigated according to most popular ruminant feeding systems. different treatments including polyethylene glycol (6000 mw), sodium hydroxide, sodium bicarbonate, potassium permanganate, wood ash, water and urea, were applied for deactivation of ct crude protein fractioning was determined using nylon bag techn...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2011
mariane trépanier ahmad tavasoli sanaz anahid ajay k. dalai

the effects of electronic properties of inner and outer surfaces of carbon nano tubes (cnts) on the deactivation of cobalt fischer-tropsch (ft) catalysts were studied. the comparative characterization of the fresh and used catalysts by tem, xrd, tpr, bet and h2 chemisorption showed that cobalt re-oxidation, cobalt-support interactions and sintering are the main sources of catalyst deactivation....

In the present study, tin-promoted Pd/MWNTs nanocatalystwas synthesized via polyol technique for application in hydrogenation of high-concentrated acetylene feedstocks. TEM images showed a restricted distribution of nanoparticles in the range of 3-5 nm. The results indicated that nanoparticles sizes were resistant to further catalyst deactivation. XRD patterns signified alloying between Pd and ...

Journal: :علوم و تکنولوژی پلیمر 0
مهدی سلامی کلجاهی محمد نجفی وحید حدادی اصل

in the current work, ethylene polymerization was investigated from a mathematical modeling point of view. the initiation (activation), propagation, termination, and deactivation reactions were taken into account and the relevant equations used in the modeling were obtained from the elementary reactions. some assumptions including neglecting the transfer and deactivation reactions were considere...

Ahmad Tavasoli, Ajay K. Dalai Mariane Trépanier Sanaz Anahid

The effects of electronic properties of inner and outer surfaces of Carbon Nano Tubes (CNTs) on the deactivation of cobalt Fischer-Tropsch (FT) catalysts were studied. The comparative characterization of the fresh and used catalysts by TEM, XRD, TPR, BET and H2 chemisorption showed that cobalt re-oxidation, cobalt-support interactions and sintering are the main sources o...

A. Moghadassi, M. Bahmani N. Amini O. Fadavi

A kinetic model of a fixed bed tubular reactor incorporating catalyst deactivation was developed for the ISOMAX unit of Arak refinery. The kinetic parameters for the hydrocracking reactions over the commercial catalyst were determined using initial activity plant data i.e. when the catalyst is fresh. Catalyst deactivation was then taken into account by means of deactivation function based on pl...

ژورنال: تحقیقات موتور 2020
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To meet consumer and legislation requirements, various technologies have been used worldwide to achieve optimal fuel consumption and to reduce greenhouse gas emissions. One of the proposed technologies is cylinder deactivation using various methods, including, injectors cutting off, closing the intake and exhaust valves and crankshaft decoupling. In this paper, a GT-Power model is created to in...

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