Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 26 for “"Alkaline Hydrolysis"”.
-
Aspects of the mechanisms of alkaline hydrolysis of amino acid esters
… pK_a^T values. The rate constants for the alkaline hydrolysis of the ω-amino acid esters have been measured at 25, 37.1 and 50.2°C, and at I = 0.1 mol⁻¹ , using the pH-Stat method. All the reactions are pseudo first order at constant pH with a rate constant, kobs. Values of kobs /[OH⁻] vary …
-
A study of the vapour phase pyrolysis and alkaline hydrolysis of chloroform
… may begin to take over as the catalyst. The alkaline hydrolysis of chloroform was studied in aqueous 1,4-dioxane (32 % w/v), at 360C. The rate of disappearance of chloroform was followed by gas-liquid chromatography, whilst the sodium hydroxide concentration was determined by titration with …
-
The alkaline hydrolysis of esters in aqueous-organic solvent mixtures. The effects of solvents and of the activity coefficients of reactants on the kinetics of the alkaline hydrolysis of methyl acetate in aqueous dioxan, aqueous dimethyl sulphoxide and aqueous diglyme (bis (2-methoxyethyl ) ether) mixtures as solvents.
Values of the rate constant for the alkaline hydrolysis of methyl acetate in various aqueous-organic solvent mixtures (dimethyl sulfoxide 0<x40.2, dioxane 0 <, x., < 0.2, methyl ethyl ketone 0<x<0.06 and diglyme, i. e. ether-bis (2-methyloxethyl) 0x<0.10) have been determined for the temperatures …
-
Design and synthesis of ring D modified steroidal hormones
… unprecedented tandem rearrangement, on attempted alkaline hydrolysis to the corresponding ketone. This product, obtained in ca. 90% yield, was formulated as (16¹R)-3-methoxy-17-oxo-15β,16¹-cyclo-14,16β-ethano-14β-estra-1,3,5(10)-triene-16¹-carbonitrile. The chemistry of the 16¹-carbonitrile was …
-
Heterologous production of recombinant peptidylglycine α-amidating monooxygenase for the production of biosimilar α-amidated peptides
… of PHM alone was measured by the inclusion of an alkaline hydrolysis step to lyse glyoxylate as a substitute for PAL catalytic activity. Multiple candidate proteins and DNA sequences for PAM were identified by genetic sequence searches and a novel fungal PHM modelled in silico. Fourteen PAM, PHM, …
-
Reaction calorimetry applied to kinetic problems. The design and construction of an isothermal calorimeter with heat compensation by the Peltier effect, and the application of the calorimeter in the study of reaction kinetics in solvent/water mixtures.
… This callorinieter has been used to study the alkaline hydrolysis of methyl acetate in dimethylsulphoxide, and tetrahydrofuran - water mixtures at 15, 25 and 35 [degrees]C. The results of other investigations on similar reactions have been reviewed and an attempt has been made to correlate the …
-
Advanced Process Design and Modeling Methods for Sustainable and Energy Efficient Processes
… and academia: glycolysis, methanolysis, and hydrolysis. We investigate the fundamental differences between these chemical pathways and highlight how differences in physical and chemical properties of reactants and products lead to processing differences. We use a combination of industrial …
-
A kinetic study of the base catalyzed ring opening of 9-methylcaffeine halide and its homologs
… cleavage was studied. The ring cleavage, via alkaline hydrolysis of the imidazole moiety, showed pseudo-first order kinetics over the pH range of 7.28 to 10.81. Activation parameters were found to be: Ea = 29.4 Kcal mole<sup>-1</sup>, △H<sup>+</sup> = 28.8 Kcal mole<sup>-1</sup> , and …
-
Studies on the Metabolism of Plant Cells in Tissue Culture
… activity. A ribonucleotide mixture prepared by alkaline hydrolysis of these tobacco-cell nucleic acid preparations, mixtures of purified ribonucleotides, or a mixture of tobacco deoxyribo- and ribonucleosides resulting from snake-venom digestion, contained no activity. Deoxyribonucleotides were …
-
The Isolation and Identification of the Anthocyanin in the Leaves of Oxalis Ortgiessi
… in four different solvent systems. Acid and alkaline hydrolysis was carried out to identify the aglycone, glycosides and organic acid. Findings. The anthocyanin of the leaves of Oxalis ortgiessi was identified as malvidin-3-rhamnoglucoside-5-glucoside from the Rf values, spectral maxima and …
-
The chemistry of some derivatives of pyrrolidine green and pyrrolidine violet
… and electronic properties. The rates of alkaline hydrolysis of the dyes at various hydroxide ion concentrations, ionic strengths, temperatures and in mixed solvents of varying composition have been investigated with a view to elucidating the mechanism of reaction and the nature of …
-
Formation and removal of pesticides and pesticide transformation products during water treatment
… peroxide, ultraviolet radiation, and high pH (alkaline hydrolysis). Due to the broad nature of the study, pesticide compounds were analyzed as multiple mixes broken into two groups based on analytical methods, those analyzed by GC/ECD and those by LC/MS. Combinations of reactive …
-
A study of some derivatives of brilliant green
… leuco-base or carbinol. A study of the alkaline hydrolysis of each dye has been made under conditions such that pseudo first order kinetics obtained. The effects on the observed rate constant of changing the hydroxide ion concentration, the concentration of the inert salt and the …
-
Synthesis and Surface Characterization of Silica-Polypeptide Composite Particles
… colloidal silica cores were obtained by the alkaline hydrolysis of tetraethyl orthosilicate (TEOS). The hydrodynamic radius can be easily controlled in the range of ƒî 20-140 nm by the water/TEOS ratio in the starting reaction mixture. The surface of the synthesized silica cores was further …
-
Greener Photoredox-Catalyzed Phosphonations of Aryl Halides
… material, and the reaction proceeds via the alkaline hydrolysis of quaternary phosphonium salts. The final work exhibits novel photocatalytic activity of N-heterocyclic carbenes (NHC) to activate aryl halides, form aryl radicals, and enable phosphonation. This method displays broad functional …
-
Design and synthesis of rotational analogues of estradiol
… to the 14,16- diene, followed by alkaline hydrolysis afforded 3-methoxy-14, 17a.-ethenoestra- , 1,3,5(10)-trien-15-one and 3-methoxy-14, l 7a.-ethenoestra-l ,3,5(1 0)-trien-16-one, with the 15-ketone as the major isomer. Treatment of these ketones with LSelectride® afforded …
-
Use of end-of-waste foamed fibers and aggregates into a cementitious mortar
… process. Moreover, some chemical treatments (alkaline hydrolysis and sol-gel deposition of nanosilica) were performed on fibers, to improve chemical adhesion with the cement paste. Finally, taking into account the need for reducing the consumption of raw materials, foamed fibers and aggregates …
-
Studies in the stability of bonds between fibre-reactive dyes and cellulose
… bond breakdown were reduced by previous alkaline hydrolysis at the 5-position of the pyrimidine ring, thus confirming the relevance of the formation of a hydroperoxide at this position to the breakdown of the dyeings. One pyrimidinyl dye which showed bond breakdown with hydrogen peroxide …
-
The synthesis and metal ion catalysed hydrolysis of methyl 4,5-diaminopentanoate
… investigations showed that in the alkaline hydrolysis of methyl 4,5-diaminopentanoate, the simple Bᴀс2 reaction is slow and masked by a competing, extremely rapid, pair of intramolecular aminolysis (lactamisation) reactions. These involve competition between five and six membered …
Page 1 of 2