objectives: the aims of this study were to test whether lightening of the overexposed radiographs improve determination of endodontic files length and whether lightened radiographs are comparable with ideally exposed radiographs. material and methods: four dried human skull coated with soft tissue-equivalent wax used for exposing radiographs of the upper molars. first, the endodontic file was p...

the anionic surfactant sodium dodecyl sulfate (sds) was degraded by novel strain ofpseudomonas aeruginosa kgs under accession no. jq328193, which was isolated from carwash wastewater. the purpose of this research was to study different optimization conditionsrequired for enhancing the biodegradation of sodium dodecyl sulfate p. aeruginosa kgs.influence of different physicochemical factors such ...

a mathematical method for calculation of the minimum cross-sectional area of a thickener is presented by obtaining minimum laboratory batch settling test data, a function, which is called settling function, is derived. this function is found to be in the form of a polynomial of third order. the settling function and mass flux relation are used for the design of thickener. the method predicts th...

alkali and alkaline earth metals hydrogen sulfate catalyzed the one-pot three component condensation reactions of aldehydes, 1,3-dicarbonyl compounds and urea or thiourea under solvent-free conditions leading to 3,4-dihydropyrimidin-2(1h)-ones in high yields at 80 °c. our results showed that biginelli reaction not only is ph dependent, but the cation of catalyst plays an important role.

In this study, the salt weathering effects on engineering properties and weight loss potential of three types of granitoid rocks were investigated. Sodium and magnesium sulfates tests were performed on core and aggregate samples. The cyclic salt weathering tests on core samples were done up to 90 cycles, while these tests on aggregate samples were done up to 40 cycles. The results showed that d...

many properties of chemicals depend on their streochemistry. among these, the effects of streoisomerism on percutaneous absorption of drugs, which is subject of the present investigation, is not well studied yet. in this study, tretinoin (tt) and isotretinoin (itt) (geometric isomers) were chosen and their permeations (alone or in the presence of each other) through enhancer-treated excised rat...

results the batch kinetics experiments showed that nom adsorption by the adsorbents followed the pseudo-second order model. results showed that the acidic ph is optimum for adsorption of nom by smz. conclusions the findings of this study show that natural zeolite modified with sodium dodecyl sulfate, as a cationic surfactant, is a promising adsorbent for removal of nom. materials and methods in...