a practical and new method for the synthesis oxindole substituted pyrrolo[2,3-d]pyrimidines by the condensation of isatin, acetophenone and 6-amino-uracil under ultrasound irradiation conditions at 60 °c was described. the reaction was developed via a sequential tandem process to afford the oxindole substituted pyrrolo[2,3-d]pyrimidines in good to excellent yields. all reactions performed effic...

a series of experiments were designed to utilize the taguchi method for investigating the effects of important parameters on the synthesis of nax zeolite and to find the best conditions of synthesis. an l9 orthogonal design of taguchi approach was applied to design experiments consisting of 9 trails. the effect of molar composition, including sio2/al2o3 and na2o/al2o3 ratios, and the crystalliz...

abstractthis study aimed to shed light on young iranian efl students’ oral proficiency improvement through explicit instruction of formulaic sequences (fss). this pretest-posttest quasi experimental study was conducted in a bilingual school in shahrekord, iran. accordingly, based on actfl opi test, two groups of low intermediate students with age range of 11 to 12 were chosen to be assigned as ...

annihilation or reduction of each kind of noise blended in correct data signals is a field that has attracted many researchers. it is a fact that fuzzy theory presents full capability in this field. fuzzy filters are often strong in smoothing corrupted signals, whereas they have simple structures. in this paper, a new powerful yet simple fuzzy procedure is introduced for sharpness reduction in ...

Stress grading (SG) layer in cable terminations limits the critical electric field and properties of SG materials are important issues which have to be considered during manufacturing and selecting procedure. In this paper, two different types of (SG) materials are analyzed by both theory and test. According to the applied theory, important parameters as: electrical resistivity, breakdown volta...

Perlite or pearl stone is a natural glass which has formed by rapid cooling of viscous lava or magma. Perlite is mainly composed of silica, aluminum, potassium and sodium. In this experiment, perlite was used as a low-cost source of Si and Al to synthesis of sodalite zeolite using the alkaline hydrothermal treatment. A statistical Taguchi design of experiments was employed to evaluate the effec...

A series of experiments were designed to utilize the Taguchi method for investigating the effects of important parameters on the synthesis of NaX zeolite and to find the best conditions of synthesis. An L9 orthogonal design of Taguchi approach was applied to design experiments consisting of 9 trails. The effect of molar composition, including SiO2/Al2O3 and Na2O/Al2O3 ratios, and the crystalliz...