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    Theoretical Investigation of Adsorption & Reactions of H2 , O2&HCO2H on Single Crystal Alloys Surfaces Based on UBI-QEP Method

    , M.Sc. Thesis Sharif University of Technology Shokoohi, Mahdiyeh (Author) ; Gobal, Fereydoon (Supervisor)
    Abstract
    The aim of this project is to investigate the mechanisms of absorption and reactions of H2, O2, HCO2H on the single crystal surfaces of transition metals alloys such as Ni-Cu and Ni-Fe and …as well as the ability to control the properties of the mentioned alloys with change in constitutions percentage. In order to achieve the objectives, Unity Bond Index-Quadratic Exponential Potential, UBI-QEP method have been employed. Using this method, the thermodynamic parameters (heat of adsorption and reaction enthalpy changes) and kinetic parameters (activation energy of the reaction) can be calculated, and using these results, intermediate, and as a result, the mechanism of heterogeneous catalytic... 

    Heavy oil thermal conversion and refinement to the green petroleum: A petrochemical refinement plant using the sustainable formic acid for the process

    , Article Biointerface Research in Applied Chemistry ; Volume 10, Issue 5 , 2020 , Pages 6088-6100 Norouzi, N ; Talebi, S ; Fabi, M ; Khajehpour, H ; Sharif University of Technology
    AMG Transcend Association  2020
    Abstract
    In this study, heat oil conversion experiments using steam and formic acid as a hydrogen carrier be carried out in a batch reactor at T = 380 degrees of Celsius and P = 165 bar. Material balance and product distribution were calculated after the process. Properties of crude oil before and after thermal conversion, including viscosity, API gravity, SARA measurement, and elemental analysis, were analyzed. It has been presented that the use of formic acid as a hydrogen carrier solvent reduces the formation of coke and gaseous products and enhances the performance of liquid products. Also, the viscosity of the refined oil decreased by 23.2% due to the addition of formic acid compared to the... 

    Techno-economic assessment of a novel power-to-liquid system for synthesis of formic acid and ammonia, based on CO2 electroreduction and alkaline water electrolysis cells

    , Article Renewable Energy ; Volume 187 , 2022 , Pages 1224-1240 ; 09601481 (ISSN) Bahnamiri, F. K ; Khalili, M ; Pakzad, P ; Mehrpooya, M ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    The power-to-liquid concept is a promising strategy to convert the power plants' flue gas to value-added liquid fuels using renewable energy. This technology could potentially reduce global greenhouse gases emissions and mitigate the environmental problems associated with the fossil fuels industry. In this regard, the main objective of the present study is to propose a novel power-to-liquid plant for the synthesis of formic acid and ammonia from power plants' flue gas, emphasizing the role of electrochemical technologies and renewable energy. The system's basis is developed by the integration of CO2 electroreduction cell, alkaline water electrolysis cell, and photovoltaic panel technologies.... 

    Oxidative Desulfurization of Light Fuel Oils

    , Ph.D. Dissertation Sharif University of Technology Sobati, Mohammad Amin (Author) ; Molaei Dehkordi, Asghar (Supervisor) ; Shahrokhi, Mohammad (Supervisor)
    Abstract
    Oxidative desulfurization (ODS) is one of the desulfurization processes that posseses several important advantages such as mild operating conditions. In the present work, oxidative desulfurization of kerosene with a total sulfur content of 2335 ppm and gas oil with a total sulfur content of 7990 ppm were carefully investigated. By evaluation of different oxidation systems, the hydrogen peroxide-formic acid system was selected for the oxidation of sulfur-containing compounds of the light fuel oils. The effects of main operating parameters of the oxidation system including temperature, hydrogen peroxide to sulfur molar ratio (O/S), and formic acid to sulfur molar ratio (Acid/S) on the... 

    Investigation of the reaction of dithiocarbamic acid salts with trimethyl orthoformate and styrene epoxide

    , Article Tetrahedron Letters ; Volume 56, Issue 51 , December , 2015 , Pages 7124-7127 ; 00404039 (ISSN) Ziyaei Halimehjani, A ; Hajilou Shayegan, M ; Poshteh, S. S ; Amani, V ; Notash, B ; Hashemi, M. M ; Sharif University of Technology
    Elsevier Ltd  2015
    Abstract
    The reaction of dithiocarbamic acid salts with trimethyl orthoformate in the presence of BF3·OEt2 was investigated to give 4-(N,N-dialkyldithiocarbamato)-2-dialkyliminio-1,3-dithietane tetrafluoroborates in good yields. Additionally, a one-pot procedure for the synthesis of 2-iminium-1,3-dithiolanes from the BF3·OEt2 catalyzed reaction of dithiocarbamic acid salts with styrene epoxide is described  

    Optimisation of a microwave-assisted method for extracting withaferin A from Withania somnifera Dunal. using central composite design

    , Article Phytochemical Analysis ; Volume 21, Issue 6 , 2010 , Pages 544-549 ; 09580344 (ISSN) Mirzajani, F ; Ghassempour, A ; Jalali-Heravi, M ; Mirjalili, M. H ; Sharif University of Technology
    2010
    Abstract
    Introduction - Recently, there have been growing attention on the modification and optimisation of new extraction and quantification methods, caused by the lack of environmentally friendly methodologies for the extraction of phytochemicals from complex matrices. In the case of pharmaceutical compounds, not only the extraction procedure but also the analysis method should be efficient, precise, fast and easy.Objectives - The essential pharmaceutical characteristics and trace concentration of withanolides led us to modify and optimise the previously reported extraction and quantification procedure for withaferin A (WA) as a candidate for withanolides.Matrial and methods - The WA from the... 

    Mechanism of photocatalytic reduction of CO2 by Ag3PO4(111)/g-C3N4 nanocomposite: a first-principles study

    , Article Journal of Physical Chemistry C ; Volume 123, Issue 36 , 2019 , Pages 22191-22201 ; 19327447 (ISSN) Tafreshi, S. S ; Moshfegh, A. Z ; De Leeuw, N. H ; Sharif University of Technology
    American Chemical Society  2019
    Abstract
    Density functional theory (DFT) calculations have been performed to investigate the electronic structure and photocatalytic activity of a hybrid Ag3PO4(111)/g-C3N4 structure. Due to Ag(d) and O(p) states forming the upper part of the valence band and C(p), N(p), and Ag(s) the lower part of the conduction band, the band gap of the hybrid material is reduced from 2.75 eV for Ag3PO4(111) and 3.13 eV for monolayer of g-C3N4 to about 2.52 eV, enhancing the photocatalytic activity of the Ag3PO4(111) surface and g-C3N4 sheet in the visible region. We have also investigated possible reaction pathways for photocatalytic CO2 reduction on the Ag3PO4(111)/g-C3N4 nanocomposite to determine the most... 

    Natural compounds for skin tissue engineering by electrospinning of nylon-Beta vulgaris

    , Article ASAIO Journal ; Volume 64, Issue 2 , 2018 , Pages 261-269 ; 10582916 (ISSN) Ranjbarvan, P ; Mahmoudifard, M ; Kehtari, M ; Babaie, A ; Hamedi, S ; Mirzaei, S ; Soleimani, M ; Hosseinzadeh, S ; Sharif University of Technology
    Lippincott Williams and Wilkins  2018
    Abstract
    Natural compounds containing polysaccharide ingredients have been employed as candidates for treatment of skin tissue. Herein, for the first time, electrospinning setup was proposed to fabricate an efficient composite nanofibrous structure of Beta vulgaris (obtained from Beet [Chenopodiaceae or Amaranthaceae]) belonged to polysaccharides and an elastic polymer named nylon 66 for skin tissue engineering. Both prepared scaffolds including noncomposite and composite types were studied by Scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, mechanical assay, and contact angle. Scanning electron microscope examinations have approved the uniform and homogeneous... 

    Oxidative desulfurization of simulated light fuel oil and untreated kerosene

    , Article Fuel Processing Technology ; Volume 90, Issue 3 , 2009 , Pages 435-445 ; 03783820 (ISSN) Dehkordi, A.M ; Kiaei, Z ; Sobati, M.A ; Sharif University of Technology
    2009
    Abstract
    An experimental investigation was conducted on the oxidative desulfurization of model sulfur compounds such as dibenzothiophene and benzothiophene in toluene as a simulated light fuel oil with a mixture of hydrogen peroxide as the oxidant and various acids as the catalyst. The influences of various parameters including reaction temperature (T), acid to sulfur molar ratio (Acid/S), oxidant to sulfur molar ratio (O/S), type of acid, and the presence of sodium tungstate and commercial activated carbon as a co-catalyst on the fractional conversion of the model sulfur compounds were investigated. The experimental data obtained were used to determine the reaction rate constant of the model sulfur... 

    Assembly of CeO 2-TiO 2 nanoparticles prepared in room temperature ionic liquid on graphene nanosheets for photocatalytic degradation of pollutants

    , Article Journal of Hazardous Materials ; Volume 199-200 , 2012 , Pages 170-178 ; 03043894 (ISSN) Ghasemi, S ; Setayesh, S. R ; Habibi Yangjeh, A ; Hormozi Nezhad, M. R ; Gholami, M. R ; Sharif University of Technology
    2012
    Abstract
    CeO 2-TiO 2 nanoparticles were prepared by the sol-gel process using 2-hydroxylethylammonium formate as room-temperature ionic liquid and calcined at different temperatures (500-700°C). CeO 2-TiO 2-graphene nanocomposites were prepared by hydrothermal reaction of graphene oxide with CeO 2-TiO 2 nanoparticles in aqueous solution of ethanol. The photocatalysts were characterized by X-ray diffraction, BET surface area, diffuse reflectance spectroscopy, scanning electron microscopy, and Fourier transformed infrared techniques. The results demonstrate that the room-temperature ionic liquid inhibits the anatase-rutile phase transformation. This effect was promoted by addition of CeO 2 to TiO 2.... 

    Green products from herbal medicine wastes by subcritical water treatment

    , Article Journal of Hazardous Materials ; Volume 424 , 2022 ; 03043894 (ISSN) Jouyandeh, M ; Tavakoli, O ; Sarkhanpour, R ; Sajadi, S. M ; Zarrintaj, P ; Rabiee, N ; Akhavan, O ; Lima, E. C ; Saeb, M. R ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    Herbal medicine wastes (HMWs) are byproducts of medicine factories, which are mainly landfilled for their environmental problems. Only bearing in mind the contamination and concerns caused by the COVID-19 pandemic and environmental emissions, the worth of herbal medicine wastes management and conversion to green products can be understood. In this work, subcritical water treatment was carried out batch-wise in a stainless tube reactor in the pressure range of 0.792–30.0 MPa, varying the temperature (127–327 °C) and time (1–60 min) of extraction. This resulted in new and green material sources, including organic acids, amino acids, and sugars. Amazingly, at very low extraction times (below 5...