Trends of Precooling in Concrete

the effect of taftan pozzolan on the compressive strength of concrete in the environmental conditions of oman sea (chabahar port)

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...

ترجمه کتاب روندهای اساسی در علم زبان the main trends in the science of language رومن یاکوبسن roman jakobson

رومن یاکوبسن (متولد 1896) یکی از نوابغ زبانشناسی مکتب پراگ است او به کمک یار همیشگی خود نیکولای تروبتسکوی (1890-1938) در تعیین خط مشی نهضت ساختگرایی اروپای شرق از همه موثرتر بودند. مهمترین تحقیقات این دو زبان شناسی در دهه قبل از جنگ جهانی دوم انجام گرفت . در زمان جنگ ، بواسطه اشغال چکسلواکی توسط آلمانها، پژوهش این اساتید متوقف گردید. یا کوبسن پس از جنگ کار خود را دنبال کرد و در زمینه واج شناسی ...

Vapor Precooling in a Pulse Tube Liquefier

Experiments were performed to study the effects of introducing vapor into a dewar where a coaxial pulse tube refrigerator was used as a liquefier in the neck of the dewar. We were concerned about how the introduction of vapor might impact the refrigeration load as the vapor barrier in the neck of the dewar is disturbed. Three experiments were performed where the input power to the cooler was he...

New Trends of Doping in Sport

Changing trends in characteristics of infantile hydronephrosis

  Background : Hydronephrosis (HN) or calycial dilatation is the most common prenatal urologic abnormality. The aim of this study was to identify the possible changes in demographic and clinical manifestations of infantile HN in previously and recently diagnosed patients.   Methods : 193 children with infantile HN admitted to Ali-asghar Children's Hospital in two different periods (group 1 1997...