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120 results for “Reaction time”
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Research ArticleOpen accessIn the abstractEnzymatic Synthesis of Palm Alkyl Ester Using Dialkyl Carbonate as an Alkyl DonorsRoila Awang, Choo Yuen MayProblem statement: Though efficient in terms of reaction yield and time, the chemical approach to synthesizing alkyl ester has drawback such as difficulties in the recovery of glycerol and the need for removal of salt residue. On the other hand, biocatalyst allow for synthesis of specific alkyl esters and easy recovery of glycerol. However, the solvent-free alcoholysis, does not give … …American Journal of Applied Sciences, Vol. 7, Issue 8 · 31 Aug 2010 · 7,235 accessesView PDFCite
Research ArticleOpen accessIn the abstractMethanol-Based Transesterification Optimization of Waste Used Cooking Oil over Potassium Hydroxide CatalystCholada Komintarachat, Sathaporn ChuepengProblem statement: Waste used Cooking Oil (WCO) harmfully affected to environment and human’s health can be a feedstock for producing biodiesel. Approach: The conversion of Fatty Acid and Free Fatty Acid (FFA) of WCO with 15.0% w/w FFA content to biodiesel was studied through transesterification reactions. This work investigated the effects of alcohol and catalyst quantity, reaction time and temperature … …American Journal of Applied Sciences, Vol. 7, Issue 8 · 31 Aug 2010 · 9,739 accessesView PDFCite
Research ArticleOpen accessIn the abstractMechanism of Microencapsulation with Urea-Formaldehyde PolymerRochmadi, Agus Prasetya, Wahyu HasokowatiProblem statement: Microcapsule is one of important fine chemical products in the current chemical industries. Better understanding of microencapsulation process is useful to properly design of microcapsule with specific characteristics. The aim of this research is to study the mechanism of Urea-Formaldehyde (UF) microcapsules formation. Approach: Microcapsule was prepared in two steps. The first step was the preparation of oil … …American Journal of Applied Sciences, Vol. 7, Issue 6 · 30 Jun 2010 · 8,715 accessesView PDFCite
Research ArticleOpen accessIn the abstractTwo Optimization Methods to Determine the Rate Constants of a Complex Chemical Reaction Using FORTRAN and MATLABAbdel-Latif Aboul Seoud, Lamiaa A.M. AbdallahProblem statement: For chemical reactions, the determination of the rate constants is both very difficult and a time consuming process. The aim of this research was to develop computer programs for determining the rate constants for the general form of any complex reaction at a certain temperature. The development of such program can be very helpful in the control of … …American Journal of Applied Sciences, Vol. 7, Issue 4 · 30 Apr 2010 · 8,042 accessesView PDFCite
Research ArticleOpen accessIn the abstractUltrasonography and Radiography Evaluation of the Cartilage Graft in Repair of Experimentally Induced Radial Bone Defect in RabbitFoad Sadi, Abbas Veshkini, Davood Sharifi, M Nasroulahzadeh MasoulehWe would like to thank to the Faculty of Specialized Veterinary Sciences research council. Science and Research Branch of Islamic Azad University, Punak Tehran for approval and financial support to finish this project. Problems statement: The purpose of this research was to determine the biological effect of cartilage graft as a bone defect filler and osteogenetic stimulation to speed up … …American Journal of Animal and Veterinary Sciences, Vol. 5, Issue 1 · 31 Mar 2010 · 7,427 accessesView PDFCite
Research ArticleOpen accessIn the abstractImmobilization of Lipase from Candida rugosa on Chitosan Beads for Transesterification ReactionM. Nasratun, H. A. Said, A. Noraziah, A.N. Abd AllaProblem statement: Further study is recommended to improve the immobilization technique and the immobilized lipase’s performance as catalysis in transesterification reaction. Approach: To investigate the ability of immobilized lipase on chitosan beads to catalyze the transesterification of cooking oil to an ester. The porous bead of chitosan was used for immobilization of lipase from Candida rugosa by physical adsorption. Parameters … …American Journal of Applied Sciences, Vol. 6, Issue 9 · 30 Sep 2009 · 7,605 accessesView PDFCite
Research ArticleOpen accessIn the abstractThe Effect of Reaction Temperature on Retaining Oxirane Oxygen Contents in the Synthesis of Epoxidized DiethanolamidesC. S. Lee, T. L. Ooi, C. H. ChuahEpoxidized diethanolamides were synthesized by reacting diethanolamine (DEA) with mixture of Epoxidized Palm Olein (EPOo ,40% w/w) and Refined Bleached Deodorized Palm Kernel Olein (RBDPKOo , 60% w/w) at 1:3 molar at 80°C for 5 h and continued at 110°C for another 4 h of reaction time. Synthesized diethanolamides with high content of epoxides were reacted with isocyanate in the … …American Journal of Applied Sciences, Vol. 6, Issue 1 · 31 Jan 2009 · 7,372 accessesView PDFCite
Research ArticleOpen accessIn the abstractSynthesis of Zeolite from Aluminium Etching By-Product: the Effect of Reaction Temperature on Crystallinity and Its CO2 Adsorption PropertyKanokorn Hussaro, Supaporn Douglas, Noppadon CheamsawatThe synthesis of zeolite from the by-product of aluminium etching process was investigated. The starting by-product reactant had high aluminium content, 92.17% wt. as Al2O3. Si and Na compositions were adjusted by the addition of sodium metasilicate, in the hydrogel process.The reaction time was fixed at 1 h., while the stirring speed was controlled at 200 rpm. and the temperature … …American Journal of Environmental Sciences, Vol. 4, Issue 6 · 31 Dec 2008 · 6,524 accessesView PDFCite
Research ArticleOpen accessIn the abstractAn Efficient Production of Oligosaccharides by a Reaction using Whole Mammalian Cells as BiocatalystsTomohisa Kato, Rie Mitsumori, Kenichi HatanakaProblem statement: Mammalian cells were used for the production of oligosaccharides by saccharide primer method. However, because cells in culture are used, productivity of oligosaccharides is low. Approach: In saccharide primer method employing cells under culture, glycosylation was performed only by mixing the collected cells in reaction mixtures. Saccharide primer, 12-azidododecyl β-lactoside that mimics lactosylceramide (LacCer), was incubated with various … …American Journal of Biochemistry and Biotechnology, Vol. 4, Issue 4 · 31 Dec 2008 · 6,439 accessesView PDFCite
Research ArticleOpen accessIn the abstractAmphoteric Starch in Simultaneous Process Preparation with Box-Behnken Design for Optimal ConditionsSopa Cansee, Juntanee Uriyapongson, Commueng Watyotha et al.Cassava starch was chemically modified to produce an amphoteric starch. The amphoteric starch was prepared in a simultaneous process which was evaluated in relation to four factors: temperature (45-55 °C), 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC, 4-12%) and sodium tripolyphosphate (STP, 2-8%) concentrations, and reaction time (2-6 h). The extent of amphoteric starch produced was determined by the degree of substitution (DS) of … …American Journal of Applied Sciences, Vol. 5, Issue 11 · 30 Nov 2008 · 7,523 accessesView PDFCite