kinetic parameters of the ammonolysis reaction of dichloroethane in nonaqueous media are studied and the optimum reaction conditions are reported. a suitable reactor for running the reaction under high pressure in the range of 50 to 500 °c is designed. kinetic behaviours of the system is studied and other reaction parameters such as rate constant, kinetic order, and activation energy are determ...

introduction: the purpose of this in-vitro study was to compare shaping ability of niti rotary mtwo and flexmaster with stainless steel hand k-flexofile in curved root canals of extracted teeth. materials and methods: mesiobuccal canals of 45 mandibular molar teeth were balanced into three groups of 15 each, with respect to the schneider angle, canal access angle, height, dis-tance and radius o...

materials and methods: one hundred and thirty five mesial root canals of mandibular first and second molar teeth were selected. access cavities were prepared. after inserting a k-file size #10 into each canal, radiographs were taken. canal curvature was determined by measuring the schneider angle, canal access angle, as well as the canal radius, length, height and curvature starting distance on...

in present study we studied using green routes for microwave assisted synthesis of alumina nanoparticles from aluminum nitrate. it was revealed that when plant extracts are used, no specific stabilizer is needed. structural characterization of nanoparticles was studied using x-ray diffraction that showed semi-crystalline structure for two of plant extracts, other xrd patterns had no significant...

objectives: during root canal preparation, apical extrusion of debris can cause inflammation, flare-ups, and delayed healing. therefore, instrumentation techniques that cause the least extrusion of debris are desirable. this study aimed to compare apical extrusion of debris by five single-file, full-sequence rotary and reciprocating systems. materials and methods: one hundred twenty human mandi...

foodstuffs analysis is very important due to population growth and increasing consumer demand for safety and nutritional excellence. the analysis of different compounds in foodstuffs is so difficult without using sample preparation techniques. traditional techniques require large amounts of toxic organic solvents. as a result, they are not only expensive but also environmentally unfriendly and ...

this is a comprehensive review of the recent progresses made in the field of zeolite membranes. it describes zeolitic materials and methods of membrane fabrication, followed by a summary of applications for gas separation, pervaporation and separation of liquid mixtures. special attention is called to polymer mixed matrix membranes (mmms) and membranes based on metal organic frame works (mofs)....

chemotherapy medication errors may lead to potentially harmful consequences while most of them could be preventable. this study aims to determine the incidence and type of drug handling and administration errors among the nurses and to identify possible contributing factors. setting of the study was a teaching hospital affiliated to shahid beheshti university of medical sciences, tehran, iran. ...