نتایج جستجو برای: solid acids

تعداد نتایج: 449142  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - پژوهشکده علوم 1388

heteropoly acids (hpa) and their salts have advantages as catalysts which make them both economically and environmentally attractive, strong br?nsted acidity, exhibiting fast reversible multi-electron redox transformations under rather mild conditions, very high solubility in polar solvents, fairly high thermal stability in the solid states, and efficient oxidizing ability, so that they are imp...

Journal: :journal of agricultural science and technology 2011
k. arzani h. khoshghalb m. j. malakouti m. barzegar

oxalate soluble pectin (osp) is related to fruit firmness with respect to the chelation of calcium ions with carboxyl groups of adjacent polyuronide chains. this study was carried out to explore the effect of time of fruit harvest, foliar spray with cacl2 during growing season on osp, polygalacturonase activity (pga), fruit firmness and the effects on fruit shelf life, quality and internal ...

Journal: :iranian journal of catalysis 2011
arash shokrolahi abbas zali hamid reza pouretedal

the esterification of free fatty acids (ffa) with methanol is studied using sulfonated porous carbon (spc) as catalyst. in compare to the amorphous sugar catalyst and protonated nafion, the proposed catalyst shows stability and high efficient performance in biodiesel production. the highest initial rate of oleic acid conversion is obtained at catalyst loading of 1 mmol h+ and mole ratio of meoh...

Journal: :international journal of environmental research 2011
t. amani m. nosrati t.r. sreekrishnan

key dissimilarities between thermophilic and mesophilic anaerobic digestion of waste activated sludge (was) were experimentally studied in this research. typical was with total solids (ts) concentrations of 30 and 60 g/l were digested anaerobically in a batch digester at mesophilic and thermophilic temperatures. solids reduction, total cod changes, the production of different volatile fatty ...

Journal: :international journal of environmental research 0
t. amani biotechnology group, chemical engineering department, faculty of engineering,tarbiat modares university, p.o. box 14115-143, tehran, iran m. nosrati biotechnology group, chemical engineering department, faculty of engineering,tarbiat modares university, p.o. box 14115-143, tehran, iran t.r. sreekrishnan department of biochemical engineering and biotechnology, i.i.t., delhi 110016, india

key dissimilarities between thermophilic and mesophilic anaerobic digestion of waste activated sludge (was) were experimentally studied in this research. typical was with total solids (ts) concentrations of 30 and 60 g/l were digested anaerobically in a batch digester at mesophilic and thermophilic temperatures. solids reduction, total cod changes, the production of different volatile fatty aci...

The role of dietary fats and oils in human nutrition is one of the most important areas of concern and investigation in the field of nutritional science. The findings of investigations on this subject have wide-ranging implications for consumers, health-care providers and nutrition educators as well as food producers, processors and distributors. New evidence concerning the benefits and risks a...

The role of dietary fats and oils in human nutrition is one of the most important areas of concern and investigation in the field of nutritional science. The findings of investigations on this subject have wide-ranging implications for consumers, health-care providers and nutrition educators as well as food producers, processors and distributors. New evidence concerning the benefits and risks a...

Journal: :iranian journal of catalysis 2014
khodabakhsh niknam seyed ahmad sajadi roghayeh hosseini mojtaba baghernejad

silica-bonded n-propyldiethylenetriamine sulfamic acid (sbpdsa) was found as an efficient solid acid for the synthesis of coumarins. coumarin derivatives were obtained via the pechmann condensation reaction of phenols and β-keto-esters at 80 oc under solvent-free conditions. also, biscoumarins were obtained via the condensation of aldehydes and 4-hydroxycoumarin in water at reflux conditions. t...

Journal: :Accounts of chemical research 2002
James H Clark

Solid acids and especially those based on micelle-templated silicas and other mesoporous high surface area support materials are beginning to play a significant role in the greening of fine and specialty chemicals manufacturing processes. A wide range of important organic reactions can be efficiently catalyzed by these materials, which can be designed to provide different types of acidity as we...

The solid–solid reactions of electron-donor compounds, such as: barbituric acid (1a), thiobarbituric acid (1b), 1,3-dimethyl barbituric acid (1c), phenol (1d) and resorcinol (1e) with diazotized o-nitroaniline (3), m-nitroaniline (4) and p-nitroaniline (5) catalyzed by p-toluenesulfonic acid (2) afford azo dyes by grinding in good yields. This new method totally avoids the use of inorganic acid...

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