نتایج جستجو برای: carbon

تعداد نتایج: 281206  

There is no single standard technique or methodology to characterize the size, structure, number, and chemical composition of airborne carbon nanotubes.  Existing analytical instruments and analytical techniques for evaluating nanoparticle concentrations cannot simultaneously provide morphology, state of agglomeration, surface area, mass, size distribution and chemical composition data critical...

Torsional dynamic analysis of carbon nanotubes under the effect of longitudinal magnetic field is carried out in the present study. Torque effect of an axial magnetic field on a carbon nanotube has been defined using Maxwell’s relation. Nonlocal governing equation and boundary conditions for carbon nanotubes are obtained by using Hamilton’s minimum energy principle. Eringen’s nonlocal stress gr...

A. Badiei M. Karimi P. Zarabadi-poor

We evaluated the effect of Fe/Alumina Catalyst contained different Cadmium contents and two synthesis temperatures on producing carbon nanotubes by chemical vapor deposition of methane as a feedstock.  X-ray powder diffraction (XRD), N2 adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and Thermogravimetry analysis (TGA) were u...

Journal: :desert 2012
h.r. motaghian j. mohammadi

in a semiarid region of central iran, effects of parent materials, physiography and landscape position, land use, andmanagement practices on association of organic carbon with secondary (aggregates) particles and aggregate stability canhave important consequences in terms of carbon sequestration and budgeting, deciding on the proper land use strategy andsuitable soil conservation practices. it ...

Journal: :desert 0
h.r. motaghian phd. student, college of agriculture, shahrekord university, shahrekord, iran j. mohammadi assoc. prof., college of agriculture, shahrekord university, shahrekord, iran

in a semiarid region of central iran, effects of parent materials, physiography and landscape position, land use, andmanagement practices on association of organic carbon with secondary (aggregates) particles and aggregate stability canhave important consequences in terms of carbon sequestration and budgeting, deciding on the proper land use strategy andsuitable soil conservation practices. it ...

Journal: :journal of physical & theoretical chemistry 2015
m. aghaie m. ghoranneviss z. purrajabi

diamond like carbon (dlc) film was grown by hot filament chemical vapor deposition (hfcvd)technique. in the present work, we investigated the quality of the dlc films groew on the substratesthat were coated with various metal nanocatalysts (au and ni). a combination of ch4/ar/h2 rendersthe growth of carbon nanostructures technique (diamond like carbon). the utilized samples werecharacterized by...

ژورنال: مرتع 2023

Abstract Background and objectives: Access to real information and data on the impact of watershed management projects and their technical and economic evaluation is possible through representative and paired catchments. Since management operations and topographic characteristics have a great impact on carbon retention in ecosystems, this study aimed to determine the amount of soil organic ca...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1390

قسمت اول: نانوذرات پالادیم قرار گرفته بر روی بسترهای فسفردار شده و بدون فسفر برای تشکیل پیوند کربن-کربن قسمت دوم: سنتز و کاربرد سنتزی نمک های آزو پیریدینیوم به عنوان مایع های یونی جدید در قسمت اول این پایان نامه، یک روش عملی و ساده برای فسفره کردن مستقیم سیلیکاژل برای تهیه سیلیکا دی فنیل فسفینیت sdpp(iv) شرح داده می شود. این سیلیکای فسفره شده با پالادیم (+2) [pd(ii)] واکنش می دهد و کاتالیزو...

Journal: :journal of nanostructures 2012
m. mazloum-ardakani a. a. mandegari s. masoum h. naeimi

a chemically modified carbon paste electrode with multiwall carbon nanotube (mwcnt) was prepared and used as a sensor for cu2+ ion. the unique chemical and physical properties of cnt have paved the way  to  new  and  improved  sensing  devices.  a  central  composite chemometrics  design  was  applied  for  multivariate  optimization  of the  effects  of  three  significant  parameters  (graphi...

ESLAMI FARSANI R., , SEDGHI A., , SHOKOUH FAR A., ,

Carbon fibers are fabricated from different materials such as special polyacrylonitrile (PAN) fibers, cellulose fibers and pitch. But PAN fibers are recognized as the most widely used precursor for the present-day manufacture of carbon fibers. The process of fabrication carbon fibers from special PAN fibers is composed of two steps including oxidative stabilization at low temperature and carbon...

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