Search for: environmental-protection
0.007 seconds
Total 25 records

    Commercial zinc oxide: a facile, efficient, and eco-friendly catalyst for the one-pot three-component synthesis of multisubstituted 2-aminothiophenes via the Gewald reaction

    , Article Industrial and Engineering Chemistry Research ; Volume 51, Issue 44 , October , 2012 , Pages 14577-14582 ; 08885885 (ISSN) Tayebee, R ; Ahmadi, S. J ; Rezaei Seresht, E ; Javadi, F ; Yasemi, M. A ; Hosseinpour, M ; Maleki, B ; Sharif University of Technology
    An eco-friendly, simple, and effective protocol is developed for the synthesis of various multisubstituted 2-aminothiophenes. In the presence of a catalytic amount of ZnO (5 mol), ketones or aldehydes, malononitrile and elemental sulfur were converted to the corresponding 2-aminothiophene derivatives in moderate to high yields (27%-70%) under solvent-free conditions at 100 °C. Zinc oxide as an efficient, readily available, and reusable catalyst, showed very good catalytic activity for the synthesis of 2-aminothiophene derivatives. Thus far, little research has been reported on the Gewald reaction under solvent-free conditions; to the best of our knowledge, this is the first time that it has... 

    Chemometric-based determination of polycyclic aromatic hydrocarbons in aqueous samples using ultrasound-assisted emulsification microextraction combined to gas chromatography-mass spectrometry

    , Article Journal of Chromatography A ; Volume 1413 , September , 2015 , Pages 117-126 ; 00219673 (ISSN) Ahmadvand, M ; Sereshti, H ; Parastar, H ; Sharif University of Technology
    Elsevier  2015
    In the present research, ultrasonic-assisted emulsification-microextraction (USAEME) coupled with gas chromatography-mass spectrometry (GC-MS) has been proposed for analysis of thirteen environmental protection agency (EPA) polycyclic aromatic hydrocarbons (PAHs) in aqueous samples. Tetrachloroethylene was selected as extraction solvent. The main parameters of USAEME affecting the efficiency of the method were modeled and optimized using a central composite design (CCD). Under the optimum conditions (9 μL for extraction solvent, 1.15% (w/v) NaCl (salt concentration) and 10min for ultrasonication time), preconcentration factor (PF) of the PAHs was in the range of 500-950. In order to have a... 

    Simulation of SO2 absorption in a venturi scrubber

    , Article Chemical Engineering Communications ; Volume 197, Issue 7 , Feb , 2010 , Pages 934-952 ; 00986445 (ISSN) Taheri, M ; Mohebbi, A ; Taheri, A ; Sharif University of Technology
    In this study, a three-dimensional mathematical model, based on a nonuniform droplet concentration distribution, has been developed to simulate gas absorption in a venturi scrubber. The mass transfer process was illustrated by assuming the liquid phase as a combination of droplets and film. The flow, just as the annular two-phase flow, includes a flow of liquid film layer on the walls and a flow of gas and liquid drops in the core. Peclet number was determined using experimental data reported by Viswanathan et al. (1984) for distribution of droplets across the cross section of the scrubber. The mathematical model for gas absorption was justified by comparing the theoretical predictions with... 

    Environmental policy-making for persian gulf oil pollution: a future study based on system dynamics modeling

    , Article Energy Sources, Part B: Economics, Planning and Policy ; Volume 12, Issue 1 , 2017 , Pages 17-23 ; 15567249 (ISSN) Khajehpour, H ; Ahmady, M. A ; Hosseini, S. A ; Mashayekhi, A. N ; Maleki, A ; Sharif University of Technology
    Environmental degradation due to economic activities is a key challenge facing sustainable development. The fossil fuel production sector is a very polluting industry. In this research, the future trends of pollution accumulation in the region due to direct/indirect oily discharge into the semi-enclosed area of the Persian Gulf are studied. The purpose of the study was not only to alert policy-makers about potential future threats in the region but also to conduct a trial to develop potential solutions to these problems. Four different environmental cases were studied via the principle of system dynamic modeling simulation. The cases consisted of three situations: relaxed, simple policy, and... 

    Multi-objective design and operation of Solid Oxide Fuel Cell (SOFC) Triple Combined-cycle Power Generation systems: Integrating energy efficiency and operational safety

    , Article Applied Energy ; Volume 185 , 2017 , Pages 345-361 ; 03062619 (ISSN) Sharifzadeh, M ; Meghdari, M ; Rashtchian, D ; Sharif University of Technology
    Elsevier Ltd  2017
    Energy efficiency is one of the main pathways for energy security and environmental protection. In fact, the International Energy Agency asserts that without energy efficiency, 70% of targeted emission reductions are not achievable. Despite this clarity, enhancing the energy efficiency introduce significant challenge toward process operation. The reason is that the methods applied for energy-saving pose the process operation at the intersection of safety constraints. The present research aims at uncovering the trade-off between safe operation and energy efficiency; an optimization framework is developed that ensures process safety and simultaneously optimizes energy-efficiency, quantified in... 

    CFD modeling of turbulent convection heat transfer of nanofluids containing green functionalized graphene nanoplatelets flowing in a horizontal tube: Comparison with experimental data

    , Article Journal of Molecular Liquids ; Volume 269 , 2018 , Pages 152-159 ; 01677322 (ISSN) Sadri, R ; Mallah, A. R ; Hosseini, M ; Ahmadi, G ; Kazi, S. N ; Dabbagh, A ; Yeong, C. H ; Ahmad, R ; Yaakup, N. A ; Sharif University of Technology
    Elsevier B.V  2018
    In this research, a series of numerical simulations were conducted utilizing computational fluid dynamics (CFD) software in order to predict the heat transfer performance of queues nanofluids containing clove-treated graphene nanoplatelets (CGNPs) flowing in a horizontal stainless steel heated pipe. The GNPs were covalently functionalized with clove buds using free radical grafting reaction using an eco-friendly process. The advantage of this synthesis method was that it did not use hazardous acids, which are typically used in traditional treatment methods of carbon nanostructures. The thermo-physical properties of the aqueous nanofluids obtained experimentally were used as inputs for the... 

    An optimization study of a palm oil-based regional bio-energy supply chain under carbon pricing and trading policies

    , Article Clean Technologies and Environmental Policy ; Volume 20, Issue 1 , 2018 , Pages 113-125 ; 1618954X (ISSN) Memari, A ; Ahmad, R ; Abdul Rahim, A. R ; Akbari Jokar, M. R ; Sharif University of Technology
    Springer Verlag  2018
    Biomass residues due to their low bulk density typically require frequent transportation from biomass plantations in rural areas to conversion bio-energy power plants. This issue contrasts with environmental protection strategies, especially when power plants are facing different carbon reduction policies that enforce them to emit less than a given specific carbon amount. Although several researchers have investigated bio-energy supply chains concerning environmental policies, the majority of studies have been devoted to strategic decisions over a single planning period. This paper presents a multi-period bio-energy supply chain under carbon pricing (carbon tax) and carbon trading... 

    Energy consumption in pervaporation, conventional and hybrid processes to separate toluene and i-octane

    , Article Chemical Engineering and Processing - Process Intensification ; Volume 128 , June , 2018 , Pages 46-52 ; 02552701 (ISSN) Khazaei, A ; Mohebbi, V ; Mosayyebi Behbahani, R ; Ramazani Saadat Abadi, A ; Sharif University of Technology
    Elsevier B.V  2018
    Chemical industries need to employ new process designs due to environmental policies and energy optimization because of the global energy challenge. Pervaporation has been introduced as a promising alternative for conventional processes such as distillation, known as energy intensive process, in chemical plants. In this work, the energy consumption of different processes for separation of toluene and i-octane (representatives of aromatics and aliphatic mixtures) has been evaluated, based on our previous laboratory pervaporation experiments using Polyvinyl alcohol/Graphene oxide mixed matrix membranes. Accordingly, hybrid distillation-pervaporation and cascade pervaporation systems have been... 

    Pervaporation of toluene and iso-octane through poly(vinyl alcohol)/graphene oxide nanoplate mixed matrix membranes: Comparison of crosslinked and noncrosslinked membranes

    , Article Journal of Applied Polymer Science ; Volume 135, Issue 7 , 2018 ; 00218995 (ISSN) Khazaei, A ; Mohebbi, V ; Behbahani, R. M ; Ramazani S. A., A ; Sharif University of Technology
    John Wiley and Sons Inc  2018
    Removal of aromatic compounds from fuel is an essential requirement in new environmental policies. In the present study, poly(vinyl alcohol)/graphene oxide (GO) mixed matrix membranes were prepared and applied to the separation of toluene from iso-octane by pervaporation, considering the similarity and interaction between graphene and aromatics. The effects of crosslinking and GO content on separation efficiency have been investigated in detail. Owing to the high affinity of GO with toluene through s and π bonds, the selectivity of the membranes was increased by incorporating a low amount of GO. The results also indicated that noncrosslinked membranes have higher selectivity and permeation... 

    Environmental impact assessment modeling in an urban man-made lake using fuzzy logic

    , Article Journal of Food, Agriculture and Environment ; Volume 7, Issue 3-4 , 2009 , Pages 811-814 ; 14590255 (ISSN) Jassbi, J ; Nouri, J ; Abbaspour, M ; Varshosaz, K ; Jafarzadeh, N ; Sharif University of Technology
    Environmental impact assessment essentially depends on diverse closely connected components and variables. For this purpose, identification of the whole components is fundamentally required. This study aims to investigate environmental impact assessment of an urban man-made lake in the western part of Tehran, based on recognition of affecting components and their reciprocal effects. Since the components are not constant during the time, thus throughout the environmental impact assessment modeling study, dynamism of the relation between the components should be considered. Regarding insufficiency and uncertainty of information, an analytical method, based on expert's opinion can be applied.... 

    Quantification of technological progress in greenhouse gas (GHG) capture and mitigation using patent data

    , Article Energy and Environmental Science ; Volume 12, Issue 9 , 2019 , Pages 2789-2805 ; 17545692 (ISSN) Sharifzadeh, M ; Triulzi, G ; Magee, C. L ; Sharif University of Technology
    Royal Society of Chemistry  2019
    Greenhouse gas emissions from anthropogenic sources are believed to be the main cause of global warming and climate change. Furthermore, fossil fuels are forecasted to remain the dominant source of energy in the near future. Therefore, capture and sequestration of greenhouse gases and in particular carbon dioxide is likely to be a major pathway toward environmental protection and energy sustainability. Such clarity has stimulated an intense and diverse range of research into various capture and mitigation technologies, which race with global warming in real-time. Quantification of the performance improvement rates of these technologies can inform decision-makers' long-term investment... 

    Assessment of sustainable groundwater resources management using integrated environmental index: Case studies across Iran

    , Article Science of the Total Environment ; Volume 676 , 2019 , Pages 792-810 ; 00489697 (ISSN) Hosseini, S. M ; Parizi, E ; Ataie Ashtiani, B ; Simmons, C. T ; Sharif University of Technology
    Elsevier B.V  2019
    Assessing environmentally sustainable GW management (ESGM) needs a deep knowledge of the present and the projected status of GW (GW) quantity and quality. Translations of these data into policy relevant information are usually done through quantitative indices. Despite the availability of a dozen GW sustainability indicators, defining an integrated index based on internationally accepted scientific standards indicators is required. To fill this gap, an in-depth review on the developed indicators/index for evaluation of GW sustainable management (GWSM) from an environmental viewpoint at aquifer scales is provided in this study. Thirteen environmentally related quantitative indicators are... 

    Assessment of Iran academic environmental education needs with climate change approach

    , Article International Journal of Environmental Science and Technology ; 2020 Ahmadi, A ; Abbaspour, M ; Afkhami Namin, N ; Sharif University of Technology
    Springer  2020
    The main goal of environmental education program developers is to train resourceful experts to work, study and solve environmental issues. Thus, it is essential to conform educational knowledge and skills according to countries needs along with scientific and technological progress. The present study aimed to assess needs of educational programs by considering climate change issues in Iranian Universities. Therefore, needs of higher education sector have been identified and some recommendations were given in line with objectives of training programs. The study applied random selection method to determine a number of environmental professionals to answer the designed questioner. Delphi method... 

    Highly uniform molybdenum oxide loaded N-CNT as a remarkably active and selective nanocatalyst for H2S selective oxidation

    , Article Science of the Total Environment ; Volume 711 , 2020 Ghasemy, E ; Emrooz, H. B. M ; Rashidi, A ; Hamzehlouyan, T ; Sharif University of Technology
    Elsevier B.V  2020
    Selective oxidation of H2S to elemental sulfur is a low cost and highly efficient process for sulfur removal from H2S-containing hydrocarbon streams in medium scale (i.e. 0.2–10 ton sulfur/day) for environmental protection and prevention of emitting toxic gases to the atmosphere. In this research, in order to prepare a highly active and selective nanocatalyst for selective oxidation of hydrogen sulfide, for the first time, molybdenum oxides were loaded uniformly over nitrogen- doped carbon nanotubes through incipient wetness impregnation. Different metal loadings including 5, 10, and 15 wt% Mo were considered in the synthesis procedure to achieve the optimized performance and provide... 

    Photocatalytic degradation of 3-methyl-4-nitrophenol over Ag/AgCl-decorated/[MOYI]-coated/ZnO nanostructures: Material characterization, photocatalytic performance, and in-vivo toxicity assessment of the photoproducts

    , Article Environmental Technology and Innovation ; 2020 Padervand, M ; Heidarpour, H ; Goshadehzehn, M ; Hajiahmadi, S ; Sharif University of Technology
    Elsevier B.V  2020
    In this work, a facile ionic liquid-mediated method was utilized to fabricate an efficient photocatalyst for environmental remediation. The eco-friendly aspect of the treatment was explored through an in-vivo toxicity bioassay. ZnO particles, prepared by a combined solid state-pyrolysis method, were coated by 1-methyl-3-(oxiran-2ylmethyl)-1H-imidazolium-3-chloride ([MOYI]Cl) ionic liquid. Then, Ag/AgCl species were grown on the surface to make a heterojunction system leading to efficient charge separation and light absorption extension to the visible domain. The products were characterized by XRD, FTIR, SEM, EDX, DRS, BET, and PL analysis. Photocatalytic performance of the nanostructures was... 

    Properties of concrete containing Guar gum

    , Article European Journal of Environmental and Civil Engineering ; 2020 Radvand, T ; Toufigh, V ; Sharif University of Technology
    Taylor and Francis Ltd  2020
    This study explores the effect of Guar gum as an eco-friendly additive on concrete mechanical characteristics. In the first stage, the slump and relative humidity tests were carried out for the fresh mortar, and tensile and compressive strengths were then determined for fifteen different mixture designs with two different curing times. Further, an exponential correlation was obtained between the ultrasonic pulse velocity and the compression test results. Additionally, scanning electron microscope (SEM) was employed to assess the bond between aggregates and Guar gum. At last, the Taguchi method and ANOVA were utilized to conduct the optimum states of the mechanical characteristics of the... 

    A heuristic trade off model for integration of distributed generations in deregulated power systems considering technical, economical and environmental issues

    , Article 2008 IEEE 2nd International Power and Energy Conference, PECon 2008, Johor Baharu, 1 December 2008 through 3 December 2008 ; 2008 , Pages 1275-1279 ; 9781424424054 (ISBN) Hekmati, A ; Nasiri, R ; Bagheri, M ; Tehrani, A. A ; Sharif University of Technology
    With the introduction of restructuring concepts to traditional power systems, a great deal of attention is given to the utilization of distributed generation. Since the integration of DG units has been known as an alternative for main grid as a resource for energy supply, the determination of optimal sizing and sitting is an important issue in the planning procedure of DG. This work presents a comprehensive multi-objective model for integration of distributed generations into a distribution network, regarding various technical, economical and environmental issues such as reduction of carbon dioxide emissions and investment & running costs while the bus voltages shall be kept within... 

    Multiple interactive pollutants in water quality trading

    , Article Environmental Management ; Volume 42, Issue 4 , 2008 , Pages 620-646 ; 0364152X (ISSN) Sarang, A ; Lence, B. J ; Shamsai, A ; Sharif University of Technology
    Efficient environmental management calls for the consideration of multiple pollutants, for which two main types of transferable discharge permit (TDP) program have been described: separate permits that manage each pollutant individually in separate markets, with each permit based on the quantity of the pollutant or its environmental effects, and weighted-sum permits that aggregate several pollutants as a single commodity to be traded in a single market. In this paper, we perform a mathematical analysis of TDP programs for multiple pollutants that jointly affect the environment (i.e., interactive pollutants) and demonstrate the practicality of this approach for cost-efficient maintenance of... 

    Merging the Porter's diamond model with SWOT method in order to analyze the Iranian technology parks competitiveness level

    , Article 2008 Portland International Center for Management of Engineering and Technology, Technology Management for a Sustainable Economy, PICMET '08, Cape Town, 27 July 2008 through 31 July 2008 ; 2008 , Pages 276-283 ; 9781890843175 (ISBN) Naserbakht, M ; Asgharizadeh, E ; Mohaghar, A ; Naserbakht, J ; Sharif University of Technology
    Purpose: This research attempts to formulate an analytical model for the studying and assessment of necessary factors that have strong effects on the level of Iranian Technology Park competitiveness. The result of this model leads to increasing the effectiveness and efficiency of Technology Parks planning stage. Methodology/Approach: The main framework of this research is based on studying the projects and research, which in their methods use the Porter's diamond model or SWOT analytical method. On the other hand, this framework is customized for the future needs of Technology Parks and clarifies the kind of information that must be gathered. Finding: Identification of the core competencies... 

    How to quantify sustainable development: A risk-based approach to water quality management

    , Article Environmental Management ; Volume 41, Issue 2 , 2008 , Pages 200-220 ; 0364152X (ISSN) Sarang, A ; Vahedi, A ; Shamsai, A ; Sharif University of Technology
    Since the term was coined in the Brundtland report in 1987, the issue of sustainable development has been challenged in terms of quantification. Different policy options may lend themselves more or less to the underlying principles of sustainability, but no analytical tools are available for a more in-depth assessment of the degree of sustainability. Overall, there are two major schools of thought employing the sustainability concept in managerial decisions: those of measuring and those of monitoring. Measurement of relative sustainability is the key issue in bridging the gap between theory and practice of sustainability of water resources systems. The objective of this study is to develop a...