نتایج جستجو برای: atmospheric carbon

تعداد نتایج: 348398  

A. Behzadmehr, B. Zahed H. Ateshi T. Fanaei S.

Chemical Vapor Deposition (CVD) is one of the most popular methods for producing Carbon Nanotubes (CNTs). The growth rate of CNTs based on CVD technique is investigated by using a numerical model based on finite volume method. Inlet gas mixture, including xylene as carbon source and mixture of argon and hydrogen as carrier gas enters into a horizontal CVD reactor at atmospheric pressure. In thi...

2014
KEITH LINDSAY GORDON B. BONAN SCOTT C. DONEY FORREST M. HOFFMAN DAVID M. LAWRENCE MATTHEW C. LONG NATALIE M. MAHOWALD J. KEITH MOORE JAMES T. RANDERSON PETER E. THORNTON

Version 1 of the Community Earth SystemModel, in the configurationwhere its full carbon cycle is enabled, is introduced and documented. In this configuration, the terrestrial biogeochemical model, which includes carbon– nitrogen dynamics and is present in earlier model versions, is coupled to an ocean biogeochemical model and atmospheric CO2 tracers. The authors provide a description of the mod...

2001
Mingkui Cao Quanfa Zhang Hank H. Shugart

Global climate change has been modifying ecosystem carbon cycling, which has produced feedbacks on climate by affecting the concentration of atmospheric CO2. The importance of biospheric CO2 uptake or release to climate change has generated great interest in quantifying the dynamic responses of terrestrial ecosystem carbon cycling to climate change. However, less attention has been given to Afr...

Journal: :journal of advances in environmental health research 0
zohreh khodaei dietary supplements and probiotic research center and department of biochemistry, genetic, and nutrition, alborz university of medical sciences, karaj, iran mahbobeh mehrabani dietary supplements and probiotic research center and department of biochemistry, genetic, and nutrition, alborz university of medical sciences, karaj, iran enayatollah kalantar department of microbiology and immunology, alborz university of medical sciences, karaj, iran parisa darabi dietary supplements and probiotic research center alborz university of medical sciences, karaj, iran afshin maleki environmental health research center, kurdistan university of medical sciences, sanandaj, iran

in the present study, carbon species including organic carbon (oc), elemental carbon (ec), and water-soluble organic carbon (wsoc) concentration in pm2.5 were assessed at an urban site of tehran, iran during march to june 2014. the pm2.5 samples were collected using an frmomnitm ambient air sampler. thermal gravimetric analysis (tga) was used to analyze oc and ec. the results showed that pm2.5 ...

Journal: :محیط شناسی 0
سعید ورامش دانشجوی دکترای جنگلداری، دانشکدة منابع طبیعی و علوم دریایی دانشگاه تربیت مدرس سید محسن حسینی دانشیار گروه جنگلداری، دانشکدة منابع طبیعی و علوم دریایی دانشگاه تربیت مدرس. نوراله عبدی استادیار گروه مرتع و آبخیزداری، دانشکده کشاورزی و منابع طبیعی، دانشگاه آزاد اسلامی، واحد اراک

co2 is the main greenhouse gas which urban forests have a high potential to absorb and sequestrate it. the air pollution of tehran is one of the most important environmental problems of the iran. to do this research 40 years old stands of robinia pseudoacacia and fraxinus rotundifolia and the surrounding barren land ( as blank) were selected in chitgar forest park of tehran and the amount of ca...

2009
A. Oschlies

The sensitivity of oceanic CO2 uptake to alterations in the marine biological carbon pump, such as brought about by natural or purposeful ocean fertilization, has repeatedly been investigated by studies employing numerical biogeochemical ocean models. It is shown here that the results of such ocean-centered studies are very sensitive to the assumption made about the response of the carbon reser...

2008
Philip Goodwin Michael J. Follows Richard G. Williams

[1] Carbon perturbations leading to an increase in atmospheric CO2 are partly offset by the carbon uptake by the oceans and the rest of the climate system. Atmospheric CO2 approaches a new equilibrium state, reached after ocean invasion ceases after typically 1000 years, given by PCO2 = P0exp(dIc/IB), where P0 and PCO2 are the initial and final partial pressures of atmospheric CO2, dIc is a CO2...

B. Zahed H. Ateshi T. Fanaei S.

The growth rate and uniformity of Carbon Nano Tubes (CNTs) based on Chemical Vapor Deposition (CVD) technique is investigated by using a numerical model. In this reactor, inlet gas mixture, including xylene as carbon source and mixture of argon and hydrogen as  carrier gas enters into a horizontal CVD reactor at atmospheric pressure. Based on the gas phase and surface reactions, released carbon...

Journal: :Chemical communications 2014
Yanzhen Zhong Wei Han

The first highly effective iron-catalyzed carbonylative Suzuki reaction has been developed. Substrates with electron-donating or electron-withdrawing functionality, ortho-substitution, as well as active groups proceeded smoothly, affording desired products in high yields. This protocol is economical, environmentally benign and practical for the synthesis of biaryl ketones.

2005
J. C. LIN C. GERBIG S. C. WOFSY B. C. DAUBE D. M. MATROSS V. Y. CHOW E. GOTTLIEB A. E. ANDREWS M. PATHMATHEVAN J. W. MUNGER

A B S T R A C T The spatial and temporal gradients in atmospheric CO 2 contain signatures of carbon fluxes, and as part of inverse studies, these signatures have been combined with atmospheric models to infer carbon sources and sinks. However, such studies have yet to yield finer-scale, regional fluxes over the continent that can be linked to ecosystem processes and ground-based observations. T...

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