نتایج جستجو برای: acid technique
تعداد نتایج: 1325767 فیلتر نتایج به سال:
All sophisticated methods for direct determination of methanol require advanced instruments and high technical knowledge which preparing them is very expensive in none developed and developing countries. This work reports a simple and efficient qualitative technique for semi determination of methanol content in herbal distillates by a new modified chromotropic acid method. The technique is base...
The electrogeochemical method is a new exploration technique with a foundation of electrochemistry. The method has ability to detect hidden ore deposits which have been covered with overburden placers and topsoil. Although this technique is unique and powerful, no attempt was made in our country to apply this new method practically so far. In this method an artificial DC electrical current has ...
All sophisticated methods for direct determination of methanol require advanced instruments and high technical knowledge which preparing them is very expensive in none developed and developing countries. This work reports a simple and efficient qualitative technique for semi determination of methanol content in herbal distillates by a new modified chromotropic acid method. The technique is base...
Two highly efficient protocols for the production of bis-coumarins under solvent-free conditions have been introduced. The reaction of 4-hydroxycoumarin (2 eq.) with arylaldehydes (1 eq.) using phthalimide-N-sulfonic acid (PhtSA) or isatin-N-sulfonic acid (IsSA), as solid-acid catalysts, afforded the mentioned compounds with good to excellent yields in short times.Briefly, we have introduced tw...
Pills of Mefenamic acid were employed as effective catalysts in the three component reaction of aromatic aldehydes, malononitrile, as well as 4-hydroxycoumarin or barbituric acid in aqueous solution, using reflux conditions in order to synthesize derivatives of dihydropyrano[2,3-c]chromene and pyrano[2,3-d]pyrimidine, correspondingly. Among the benefits of this technique, ...
a novel acrylic acid-functionalized fe3o4 magnetic nanoparticle with a core-shell structure was developed for utilization as a heterogeneous organosuperacid in chemical transformations. the structural, surface, and magnetic characteristics of the nanosized catalyst were investigated by various techniques such as transmission electron microscopy (tem), thermogravimetric analysis (tga), and ft-ir...
The aim of the present study is to study the effects of adding diopside (CaMgSi2O6) as well as silica sulfuric acid nanoparticles to ceramic part of glass ionomer cement (GIC) in order to improve its mechanical properties. To do this, firstly, diopside (DIO) nanoparticles with chemical formula of CaMgSi2O6 were synthesized using sol-gel process and then, the structural and morphological p...
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