نتایج جستجو برای: heavy propylene tetramer
تعداد نتایج: 135121 فیلتر نتایج به سال:
Backgrounds and Objectives:Propylene glycol is applied in many industries as raw material and can be released to the environment through wastewater of such industries. The biological treatment of solutions containing high concentration of propylene glycol is difficult and some problems can be observed during this process. The main objective of this study was the investigation of electrochemical...
Neutron diffraction with isotopic substitution has been used to investigate the liquid structures of propylene carbonate and glycerol carbonate. C-HO[double bond, length as m-dash]C hydrogen-bonding motifs dominate the local structure of propylene carbonate, giving rise to the formation of head-to-tail correlated chains of molecules. In contrast, glycerol carbonate exhibits a more disordered st...
Thermal cracking of a heavy liquid hydrocarbon was performed in a laboratory scale tubular reactor. Central Composite Design (CCD), was used as an experimental design method. The design variables were Coil Outlet Temperature (COT), feed flow and rate steam ratio. Maximum yield of ethylene was 30.37 wt% at COT, residence time and steam ratio of 869oC, 0.208 s and 1.22 g/g, respect...
The reactions between phenyl radicals (C6H5) and propylene (CH3CHCH2) together with its D6- and two D3-isotopologues were studied under single collision conditions using the crossed molecular beams technique. The chemical dynamics inferred from the center-of-mass translational and angular distributions suggests that the reactions are indirect and initiated by an addition of the phenyl radical t...
Crossed molecular beams experiments were utilized to explore the chemical reaction dynamics of ground-state cyano radicals, CN(X(2)Sigma(+)), with propylene (CH3CHCH2) together with two d3-isotopologues (CD3CHCH2, CH3CDCD2) as potential pathways to form organic nitriles under single collision conditions in the atmosphere of Saturn's moon Titan and in the interstellar medium. On the basis of the...
The selective oxidation of propylene to acrolein was investigated over a well-defined supported V2O5/Nb2O5 catalyst, containing a surface vanadia monolayer, with combined operando Raman/IR/MS, temperature programmed surface reaction (TPSR) spectroscopy and isotopically labeled reactants (O2 and C3D6). The dissociative chemisorption of propylene on the catalyst forms the surface allyl (H2CdCHCH2...
Kinetics and mechanism of vanadium catalysed asymmetric cyanohydrin synthesis in propylene carbonate
Propylene carbonate can be used as a green solvent for the asymmetric synthesis of cyanohydrin trimethylsilyl ethers from aldehydes and trimethylsilyl cyanide catalysed by VO(salen)NCS, though reactions are slower in this solvent than the corresponding reactions carried out in dichloromethane. A mechanistic study has been undertaken, comparing the catalytic activity of VO(salen)NCS in propylene...
The synthesis of propylene oxide from propylene glycol, a derivative of bio-glycerol, was firstly realized in the presence of alkali-loaded silica catalysts to achieve 44% conversion and 70% selectivity.
Propylene (propene) is one of the most important feedstocks in the chemical industry. It is a starting material for the synthesis of a wide variety of commodity chemicals ranging from small molecules (cumene, isopropanol, acrylonitrile, acrylic acid, propylene oxide, and butyraldehyde) to polymers (most notably, polypropylene). In 2013, approximately 85 million tons of propylene were processed ...
objective: the aim of the present study was to evaluate the efficacy of two caries detector dyes in the diagnosis of dental caries. materials and methods: twenty extracted human posterior teeth without pulpal exposure were sectioned mesiodistally through the center of the lesions using a water-cooled disk. the tooth halves were randomly divided into two groups and treated with caries detector (...
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