نتایج جستجو برای: carbon

تعداد نتایج: 281206  

A. Badiei, M. Azmard, M. Karimi, P. Zarabadi-poor

Carbon nanotubes were synthesized over a series of Zn-containing Fe/alumina catalysts by chemical vapor deposition method at two reaction temperatures of 850 and 950 °C using methane as a carbon source. Catalysts were synthesized by keeping Fe concentration constant and varying Zn concentration to study the effects of Zn. The catalysts were characterized using X – ray powder diffraction and N2 ...

In this article, we have performed calculations for studying the stability of the carbon group elements such as Si and Ge and also the magnetic elements like Fe and Co via first principle investigations. We found that Si and Ge decoupled from the interior surface of carbon nanotubes, this fact was independent in curvature, radius, conductivity and numbers of atoms in the carbon nanotubes. But t...

A. Ahmadpour M.A. Fanaei S. Rashidi

Carbon nanostructures are famous structures which are used in several industries such as separation, treatment, energy storage (i.e. methane and hydrogen storage), etc. A successful modeling of activated carbon preparation is very important in saving time and money. There are some attempts to achieve the appropriate theoretical modeling of activated carbon preparation but most of them were almo...

F MalekGhaini, M J Torkamany, M Jokar, M Sheikhi,

Weld area and weld depth/width ratio can be considered to be of the most important geometrical factors in pulsed laser welding. The effects of carbon dioxide and oxygen additions to the argon shielding gas on the weld properties in pulsed laser welding of low carbon steel is investigated. Presence of carbon dioxide and oxygen up to 10 and 15 percent respectively decreases the weld geometrical f...

 Communities or ecosystems with higher biodiversity also have higher levels of ecosystem function and services, so the relationship between functional diversity and sustainability of plant communities is essential to predict ecosystem functioning. The aim of the present study was to investigate the relationship between carbon stocks and different species diversity and functional indices as well...

ژورنال: مرتع 2023

Background and objectives: Organic carbon is one of the important parameters to determine soil fertility, and production ability and is a mind index for showing soil quality, especially in dry and semi-dry lands. The rangelands are composed of about 50 % of the world's lands and have more than 33 % of carbon reservoirs on earth. Considering the ranges as the most important terrestrial ecosystem...

Journal: :مهندسی بیوسیستم ایران 0
سیدحسن پیشگرکومله دانشگاه تهران اسداله اکرم عضو هیئت علمی علیرضا کیهانی عضو هیئت علمی

agriculture (mechanization), food industry and environment are the concepts that cannot be surveyed separately (because of their interaction). present research aimed to study tomato paste production by applying life cycle assessment. two functional unit of kg co2-eq/ kg tomato and kg co2-eq / kg paste was used. data were collected from one paste factory in alborz province and open-field tomato ...

Journal: :محیط زیست طبیعی 0
سیده خدیجه مهدوی استادیار دانشگاه ازاد اسلامی واحد نور احمد چوپانیان دانش آموخته دانشگاه آزاد اسلامی واحد نور مهشید سوری استادیار دانشکده منابع طبیعی دانشگاه ارومیه

given the potential for carbon storage in plant tissues, this approach has a serious interest in recent decades. therefore, the ability of carbon storage in astragalus gossypinus and astragalus parrowianus were examined in part of alpine pastures in kermanshah province. after determining the representative districts, according to 4 main aspect and 5 category elevation was determined representat...

Journal: :iranian journal of radiation research 0
h. noshad nuclear science research school, nuclear science & technology research institute (nstri), atomic energy organization of iran, tehran, iran

background: high-velocity carbon ion beams represent the most advanced tool for radiotherapy of deep-seated tumors. currently, the superiority of carbon ion therapy is more prominent on lung cancer or hepatomas. materials and methods: the data for lateral straggling and projected range of monoenergetic 290 mev/u (3.48 gev) carbon ions in muscle tissue were obtained from the stopping and range o...

Journal: :علوم زیستی ورزشی 0
محمد فشی استادیار دانشکدۀ تربیت بدنی و علوم ورزشی دانشگاه شهید بهشتی، تهران، ایران حمید آقا علی نژاد دانشیار فیزیولوژی ورزشی گروه تربیت بدنی و علوم ورزشی دانشگاه تربیت مدرس، تهران، ایران حسن اصیلیان مهابادی دانشیار مهندسی بهداشت حرفه ای، گروه بهداشت حرفه ای و محیط، دانشکدۀ علوم پزشکی، دانشگاه تربیت مدرس، تهران، ایران بتول رضایی سراجی دکتری فیزیولوژی ورزشی گروه تربیت بدنی و علوم ورزشی دانشگاه تربیت مدرس، تهران، ایران بهزاد پاک راد دکتری فیزیولوژی ورزشی گروه تربیت بدنی و علوم ورزشی دانشگاه تربیت مدرس، تهران، ایران

the present study aimed at evaluating the effect of aerobic exercise in carbon black particulates air pollution on tlr4 and tnf-α gene expression in male rats. 24 male wistar rats (mean body mass 279.29+26.97 gr) were randomly divided into 4 groups: a) control, b) aerobic exercise, c) pollution, d) exercise+pollution. a particulates injector and falounak chamber were used to expose the rats to ...

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