نتایج جستجو برای: pore size

تعداد نتایج: 587659  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم و فنون مازندران 0

مدل روزنه های موازی موج دار (corrugated oarallel bundle model) برای تعریف اثر ساختمان روزنه ها در نفوذ-واکنش (diffusion and reaction) در کاتالیستهای متخلخل بکار می رود. در مدل روزنه های موج دار، از یک دسته روزنه های اصلی (pore) استفاده شده است . هر یک از این روزنه های اصلی دارای یکسری عناصر روزنه می باشد که هر عنصر دارای یک شعاع تعیین شده به صورت اتفاقی از یک توزیع اندازه روزنه ها (pore size di...

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

in solvo-hydrothermal method, xrd pattern was indicated presence of intermediate of ammonium octatmolybdate and ammonium tetramolybdate, which were changed to stble phase of ?-moo3 annealing. sem images were indicated nanoparticle with semispheical morphology and tem image was demonstrated nanoparticles with a diameter size of 25nm. also in impregnate method. the xrd pattern was shown high crys...

Journal: :international journal of nano dimension 0
tayseir mohammed abd ellateif chemical engineering department, universiti teknologi petronas, tronoh-31750, perak, malaysia saikat maitra government college of engineering and ceramic technology, kolkata-700010, india

in the present investigation surface modification of silica nanoparticles by alumina was carried out by sol-gel process. fourier transform infrared (ftir) and x-ray fluorescence (xrf) confirmed the synthesis of silica and the surface modification as alumina is anchored to silica surface. field emission scanning electron microscopy (fesem) and transmission electron microscopy (tem) investigation...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه مازندران 1389

به طور کلی کاتالیست ها در دو دسته کاتالیست های روش هم رسوبی و اگزالات قرار دارند. از گروه اول 6 و از گروه دوم 4 کاتالیست تهیه گردید رفتار کاتالیست ها در شرایط مختلف گازی مختلفی از غلظت های دی اکسید کربن و مونواکسید کربن مورد بررسی قرار گرفت. تست های شناسایی کاتالیست شامل xrd، bet، pore size distributin، جذب شیمیایی و tpr انجام گرفت و با نتایج حاصل از تست راکتوری بررسی شد. نتایج نشان داد در بین ...

Journal: :transport phenomena in nano and micro scales 2014
f. haghighatju h. hashemipour rafsanjani

three activated carbons are synthesized in a rotary reactor at different activation times. the adsorption isotherms of the samples are measured the pore size distribution of the samples is determined using combined saito and foley method, bjh method. an average potential function has been determined inside the cylindrical pores. the effect of activation time on the pore size distribution sample...

Journal: :شیمی کاربردی 0
سید رضا عظیمی پیرسرائی حسن اصیلیان مهابادی احمد جنیدی جعفری زهره فرهمند کیا جعفر تاران

the characterizations of natural diatomite from birjand deposit (iran) were studied such as chemical compositions, specific surface area, total pore volume, pore size distribution and xrd. the diatomite that was treated only with sulfuric acid displayed a larger surface area, expanded total pore volume and increased pore size in comparison with both washed natural diatomite with deionized water...

Journal: :Physical chemistry chemical physics : PCCP 2014
Ulka Suryavanshi Veerappan V Balasubramanian Kripal S Lakhi Gurudas P Mane Katsuhiko Ariga Jin-Ho Choy Dae-Hwan Park Abdullah M Al-Enizi Ajayan Vinu

Novel mesoporous BN and BCN materials with cage type porous structure and spherical morphology have been synthesized using carbon nanocages with 3D porous structure as a template via an elemental substitution method at a low synthesis temperature. The obtained materials exhibit a large specific pore volume with uniform pore size distribution and the specific surface area ranging from 945 to 102...

Journal: :PDA journal of pharmaceutical science and technology 2005
Kurt Brorson Gail Sofer Hazel Aranha

2013
Tae-Yeon Cho Chi-Whan Han Yongseok Jun Soon-Gil Yoon

Acetylene-black paste without a light scattering layer was applied to meso-porous TiO2 photo-electrode films with a crystalline framework, a low residual carbon, and a tunable morphological pore size. The thermal-treated TiO2 photo-electrode films had an increased acetylene-black concentration with an increase in artificial pores and a decrease in residual carbon. The performance of dye-sensiti...

Journal: :Nanotechnology 2011
G R Willmott B G Smith

Recently, Kowalczyk et al (2011 Nanotechnology 22 315101) introduced a model for calculating the conductance of an hourglass-shaped nanopore, and the conductance change when DNA is introduced into such a pore. Here, we comment on their model in the context of other literature addressing the same general problem. Existing work includes widespread use of an alternative model, contradicts the aut...

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