determination of uranium in natural water and complex solutions using ion exchange chromatography: a combined procedure using ion exchange chromatography and uv-vis spectrophotometry techniques has been developed to measure uranum in natural water and complex solutions. after conditicing , one hundred milli liters of sample solutions have been passed through an ion exchange column,pachked with ...

this research has been taken among the students of high school in karaj city during the years 1391 and 1392. this is a survey research and data gathering is through questionnaires. studying the “an analysis of students’ tendency toward non-native reference groups in karaj”. the questionnaire was distributed among 260 of these students who were chosen through multi step cluster sampling. conside...

cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...

abstract english language learning in iran has become significant in recent years, and english has been included in the curriculum of iranian schools and universities, and considerable attention has been paid to this language in our society. nevertheless, teaching and learning english in iranian schools has not been able to satisfy the specified goals, so different efl institutes have been est...

seismic retrofit strategies have been developed in the past few decades following the introduction of new seismic provisions and the availability of advanced materials and methods. it can be observed that new approaches to deal with more lateral forces are more innovative and more energy absorbent. in line with this, there is a growing trend toward the use of steel shear walls as a system with ...

چکیده نمایشگاه های جهانی یا اکسپو عنوانی ست که از سال 1851 میلادی در لندن توسط همسر ملکه انگلستان شکل گرفت ، هدف اولیه این نمایشگاه ها نمایش دستاورد های صنعتی بود، اما در طول 165 سال که این نمایشگاه های برگزار گردیدند ، رویکرد آنها تغییر کرده است . در هر دوره به یک شعار که در واقع دغدغه اصلی جهان، در آن زمان بوده است ، پاسخ داده شده و راه حل کشور های مختلف در مورد آن موضوع به نمایش گذارده شد...

one very decisive factor in students’ academic destiny is the result they get at final term examinations. because of its importance, both students and teachers are curiously anxious about them. as normally it is the case, these final term tests are prepared hurriedly in short time by teachers which result in students’ dissatisfaction, complaining on how the test was different from their expecta...

data envelopment analysis (dea) is a powerful tool for measuring relative efficiency of organizational units referred to as decision making units (dmus). in most cases dmus have network structures with internal linking activities. traditional dea models, however, consider dmus as black boxes with no regard to their linking activities and therefore do not provide decision makers with the reasons...