نتایج جستجو برای: heterogeneous solid acid

تعداد نتایج: 1038811  

2002
V. H. Grassian

Particles present in the Earth’s atmosphere provide reactive surfaces for potentially important chemistry. The role of heterogeneous reactions of trace atmospheric gases on solid aerosol surfaces present in the troposphere is not well understood. Laboratory investigations can provide a basis for understanding the detailed molecularlevel physical chemistry of these atmospheric reactions. Kinetic...

Ameneh Malekzadeh Fatemeh Abiar Dil Khodabakhsh Niknam Marzieh Makvandi Mojtaba Baghernejad

Silica-bonded n-propyltriethylene-tetramine (SBNPTT) was found as an efficient solid base for the synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromenes. Chromene derivatives were obtained via the three-component condensation reaction of aromatic aldehydes, malononitrile, and dimedone at 80 oC under solvent-free conditions. The heterogeneous solid base showed much the same efficiency when u...

2012
Feng Guo Zhen Fang

Biodiesel is usually produced by transesterification of vegetable oils or animal fats with chemical catalysts, especially in the presence of strong acidic or basic solutions, such as hydrochloric acid, sulphuric acid, sodium hydroxide, sodium methoxide and potassium hydroxide. Homogeneous alkali catalysts can convert triglycerides to their corresponding fatty acid methyl esters (FAMEs) with hig...

Journal: :Maejo International Journal of Energy and Environmental Communication (MIJEEC) 2021

Biodiesel, an environmentally friendly biomass-based fuel, is gaining popularity globally as a cost-effective way to meet rising fuel demand. However, the high cost of raw materials and catalysts continues drive up biodiesel production. An alternative feedstock with heterogeneously catalyzed reaction could be most stabilize industrial growth. Understanding these issues led idea using waste palm...

Ameneh Malekzadeh Fatemeh Abiar Dil Khodabakhsh Niknam Marzieh Makvandi Mojtaba Baghernejad

Silica-bonded n-propyltriethylene-tetramine (SBNPTT) was found as an efficient solid base for the synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromenes. Chromene derivatives were obtained via the three-component condensation reaction of aromatic aldehydes, malononitrile, and dimedone at 80 oC under solvent-free conditions. The heterogeneous solid base showed much the same efficiency when u...

Journal: :journal of agricultural science and technology 2010
m. mazaheri asadi m. nikkhah

a solid state fermentation method was developed for the production of citric acid from date pulp (obtained of date syrup production from the process) by aspergillus niger ptcc 5010. poor yield was obtained when potassium ferrocyanide treated date pulp were used as substrate, but methanol at a 3-4% concentration markedly increased the forma-tion of citric acid from the waste. the optimum range o...

Sulfonic acid functionalized SBA-15 (SBA-Pr-SO3H) with pore size 6 nm as an efficient heterogeneous nanoporous solid acid catalyst exhibited good catalytic activity in the Biginelli-like reaction in the synthesis of spiroheterobicyclic rings with good yield and good recyclability. Spiro-pyrimidinethiones/spiro-pyrimidinones-barbituric acid derivatives were synthesized in a simple and efficient ...

Alkanedisulfamic acid functionalized silica-coated magnetic nanoparticles (ADSA-MNPs) were used as effective, low-cost and reusable solid heterogeneous nanomagnetic catalysts for conversion of aldehydes and ketones to corresponding gem-dihydroperoxides and 1,2,4,5-tetraoxanes using aqueous hydrogen peroxide (30% w/w in H2O) at room temperature. These compounds are important ...

Journal: :Organic & biomolecular chemistry 2016
Sofia M Bruno Ana C Gomes Tânia S M Oliveira Margarida M Antunes André D Lopes Anabela A Valente Isabel S Gonçalves Martyn Pillinger

Metal-free cucurbit[7]uril (CB7) solid-state assemblies promote acid-catalysed alcoholysis of aliphatic and aromatic epoxides under mild conditions to give β-alkoxy alcohols, which are important intermediates for the synthesis of a vast range of compounds such as bioactive pharmaceuticals. The catalytic process is heterogeneous and the catalyst can be reused in consecutive runs without any reac...

Journal: :journal of pharmaceutical and health sciences 0
narges esmaeili fard دانش آموخته کارشناسی ارشد، گروه آموزشی علوم و صنایع غذایی، دانشکده فناوری های نوین، واحد علوم دارویی دانشگاه آزاد اسلامی manochehr bahmaei north tehran branch parvin eshratabadi institute of standard and induatrial research

margarine contains a higher level of unsaturated and trans-fatty acids (tfa) than butter. the aim of this study was to investigate the physicochemical properties of these products in iranian market during storage. physicochemical analyses included fatty acid composition, peroxide and anisidine values, slip melting point (smp), color, chlorophyll content, solid fat content (sfc) and texture anal...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید