نتایج جستجو برای: solvent ratio

تعداد نتایج: 553282  

2015
Jiulong Xie Xianglin Zhai Chung Yun Hse Todd F. Shupe Hui Pan

Bagasse flour (BF) was liquefied using bi-component polyhydric alcohol (PA) as a solvent and phosphoric acid as a catalyst in a microwave reactor. The effect of BF to solvent ratio and reaction temperatures on the liquefaction extent and characteristics of liquefied products were evaluated. The results revealed that almost 75% of the raw bagasse was converted into liquid products within 9 min a...

2014
Chloe D. Goldsmith Quan V. Vuong Costas E. Stathopoulos Paul D. Roach Christopher J. Scarlett Maria G. Miguel João Rocha

Olive leaves are an agricultural waste of the olive-oil industry representing up to 10% of the dry weight arriving at olive mills. Disposal of this waste adds additional expense to farmers. Olive leaves have been shown to have a high concentration of phenolic compounds. In an attempt to utilize this waste product for phenolic compounds, we optimized their extraction using water-a "green" extrac...

Journal: :iranian journal of pharmaceutical sciences 0
fatemah atyabi department of pharmaceutics, faculty of pharmacy, tehran university of medical sciences, tehran, iran afsaneh mohammadi department of pharmaceutics, faculty of pharmacy, tehran university of medical sciences, tehran, iran rassoul dinarvand department of pharmaceutics, faculty of pharmacy, tehran university of medical sciences, tehran, iran

the purpose of this study was to prepare and characterize nimodipine loaded microspheres using ethyl cellulose (ec) as a carrier polymer through an emulsion solvent evaporation method. these evaluations characterized the pattern of drug release from prepared microspheres. nimodipin loaded microspheres were prepared using an emulsification solvent evaporation method. the effect of process variab...

The complexation reactions between 4-(2-pyridy1azo)-resorcinol and Cd ,H g and Pb io ns have been investigated in acetonitrile-dimethyEomamide mixtures at various temperatures using a spectrophotometric technique. The stoichiometry and the formation constants of the complexes formed in solution were calculated by computer refinement of absorbance-mole ratio data using nonlinear least-square ...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2004
ali kakanejadifard s. morteza farnia golamreza najafi

the one pot reaction of glyoxal and hydroxylamine hydrochloride in aqueous sodium hydroxide was found to be a safe and inexpensive method for the preparation of diaminoglyoxime. by increasing stoichiometric ratio of the hydroxylamine hydrochloride and decreasing the solvent volume, the product yield increased considerably (~ 70%).

2014
Roswanira Abdul Wahab Mahiran Basri Raja Noor Zaliha Raja Abdul Rahman Abu Bakar Salleh Mohd Basyaruddin Abdul Rahman Naz Chaibakhsh Thean Chor Leow

Most substrate for esterification has the inherent problem of low miscibility which requires addition of solvents into the reaction media. In this contribution, we would like to present an alternative and feasible option for an efficient solvent-free synthesis of menthyl butyrate using a novel thermostable crude T1 lipase. We investigated the effects of incubation time, temperature, enzyme load...

2006
A.I.Y. Tok F.Y.C. Boey S. W. Du B. K. Wong

This paper studies the feasibility of using flame spray to produce ZrO2 nano-particles using a liquid precursor. The effects of varying precursor concentrations and ratio of diluting medium on the phase composition, size and morphology of ZrO2 nano-particles are discussed. The morphology and size of the ZrO2 nano-particles was very much dependent on the precursor concentration. The solvent rati...

2009
Kou-Lin Zhang Bo Yang Seik Weng Ng

The water-coordinated metal centre in the title salt, [Zn(C(12)H(8)N(2))(2)(H(2)O)(2)]C(7)H(4)O(6)S·4H(2)O, is chelated by the two bidentate N-heterocycles, leading to an overall distorted octa-hedral environment. The cation, dianion and solvent water mol-ecules inter-act by O-H⋯O hydrogen bonds to form a layer motif. The SO(3) group is disordered over two positions with respect to the O atoms ...

2010
P. A. GÓMEZ I. D. GIL

−− The aim of this work is to simulate and analyze an extractive distillation process (extractive distillation and recovery columns) for the separation of Tetrahydrofuran (THF)-Water azeotropic mixture using Aspen Plus® and Aspen Split simulators. Calculation of vapor liquid equilibrium of Tetrahydrofuran–Water–Entrainer system was done using the NRTL model, which binary interaction parameters ...

Journal: :Organic & biomolecular chemistry 2003
Keith Smith Simon D Roberts Gamal A el-Hiti

Highly regioselective dialkylation of naphthalene using various alkylating agents can be achieved over zeolite catalysts. For example, the tert-butylation of naphthalene (1) using tert-butanol in cyclohexane over a dealuminated H-Mordenite (HM) zeolite has been optimised to give a 60% yield of 2.6-di-tert-butylnaphthalene (3) with a 2.6/2.7 ratio of over 50. This has been achieved by varying th...

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