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    Determine oil content in petroleum waxes

    , Article Hydrocarbon Processing ; Volume 85, Issue 6 , 2006 , Pages 95-97 ; 00188190 (ISSN) Mafi, M ; Yazdani, F ; Farhadi, F ; Sharif University of Technology
    2006

    STATCOM System Cooling Optimization

    , M.Sc. Thesis Sharif University of Technology Mafi, Behrang (Author) ; Rajabi Qahnuyeh, Abbas (Supervisor)
    Abstract
    Today's electric power industry is unthinkable without high-power electronic converters. Statcom is one of the critical equipment; which is known for its quick response in reactive power compensation/supply. Losses in a high-power system are considerable. Most of these losses are caused by switching. In a conventional system, the cooling system is used only to control the temperature and stable operation of the switches. In this project, an attempt is made to evaluate the temperature of the outlet fluid for use in the Rankine cycle with organic materials by modeling the heat-generating parts in the Statcom equipment. Also, the unification of the Stacom cooling system with the Rankine cycle... 

    Regression test selection in test-driven development

    , Article Automated Software Engineering ; Volume 31, Issue 1 , 2024 ; 09288910 (ISSN) Mafi, Z ; Mirian-Hosseinabadi, S. H ; Sharif University of Technology
    2024
    Abstract
    The large number of unit tests produced in the test-driven development (TDD) method and the iterative execution of these tests extend the regression test execution time in TDD. This study aims to reduce test execution time in TDD. We propose a TDD-based approach that creates traceable code elements and connects them to relevant test cases to support regression test selection during the TDD process. Our proposed hybrid technique combines text and syntax program differences to select related test cases using the nature of TDD. We use a change detection algorithm to detect program changes. Our experience is reported with a tool called RichTest, which implements this technique. In order to... 

    Hydrazine-modified starch coated magnetic nanoparticles as an effective pH-responsive nanocarrier for doxorubicin delivery

    , Article Journal of Industrial and Engineering Chemistry ; Volume 39 , 2016 , Pages 203-209 ; 1226086X (ISSN) Zohreh, N ; Hosseini, S. H ; Pourjavadi, A ; Sharif University of Technology
    Korean Society of Industrial Engineering Chemistry  2016
    Abstract
    A novel, magnetic nanocarrier was successfully synthesized through a facile and economical producer in which Fe3O4 magnetic nanoparticles were coated by starch-g-poly (methyl methacrylate-co-PEG-acrylamide). The surface of nanocarrier was then modified by hydrazine to preparation of a pH-responsive carrier. The resulted nanocarrier was applied for delivery of doxorubicin (DOX) as an effective anti-cancer drug. DOX was reacted with hydrazine linkage on the surface of nanocarrier to form hydrazone bond. Due to the presence of numerous hydrazine groups on the surface of magnetic nanocarrier large amounts of DOX was loaded onto the carrier (327 mg g−1). © 2016 The Korean Society of Industrial... 

    Test Case Selection in Test-Driven Development

    , Ph.D. Dissertation Sharif University of Technology Mafi, Zohreh (Author) ; Mirian Hosseinabadi, Hassan (Supervisor)
    Abstract
    The large number of unit tests produced in the test-driven development (TDD) method and the iterative execution of these tests extend the regression test execution time in TDD. This study aims to reduce test execution time in TDD. We propose a TDD-based approach that creates traceable code elements and connects them to relevant test cases to support regression test selection during the TDD process. Our proposed hybrid technique combines text and syntax program differences to select related test cases using the nature of TDD. We use a change detection algorithm to detect program changes. Our experience is reported with a tool called RichTest, which implements this technique. To evaluate our... 

    Physical and hydraulic properties of a new spring packing

    , Article CHISA 2006 - 17th International Congress of Chemical and Process Engineering, Prague, 27 August 2006 through 31 August 2006 ; 2006 ; 8086059456 (ISBN); 9788086059457 (ISBN) Mafi, M ; Yazdani, F ; Farhadi, F ; Deldari, H ; Sharif University of Technology
    2006
    Abstract
    Physical and hydraulic properties of new stainless steel spring packing are introduced. The measured hydraulic properties are: dry and wetted packed bed pressure drop, loading and flooding points and the liquid holdups. The appropriate coefficients for predicting the mentioned hydraulic properties from different correlations are also reported. Hydraulic properties for this packing are compared with available packings. In spite of small size, the dry and wetted packed bed pressure drops of spring packing are less than similar Raschig and Protruded rings. The total liquid holdup of this packing is greater than other commercial packings. The big total liquid holdup and physical surface area are... 

    Cross-linked poly (dimethylaminoethyl acrylamide) coated magnetic nanoparticles: a high loaded, retrievable, and stable basic catalyst for the synthesis of benzopyranes in water

    , Article RSC Advances ; Vol. 4, issue. 91 , 2014 , p. 50047-50055 Zohreh, N ; Hosseini, S. H ; Pourjavadi, A ; Bennett, C ; Sharif University of Technology
    2014
    Abstract
    A novel heterogeneous catalyst has been synthesized based on the distillation-precipitation-polymerization of methyl acrylate onto modified magnetic nanoparticles followed by the amidation of the methyl ester groups using N,N-dimethylethylenediamine. The resulting poly(dimethylaminoethyl acrylamide) coated magnetic nanoparticles (MNP@PDMA) catalyst was characterized using an array of sophisticated analytical techniques, including FT-IR, TGA, SEM, TEM, CHN, vibrating sample magnetometer (VSM), and XRD analysis. The resulting heterogeneous base catalyst allowed the performance of a domino Knoevenagel condensation/Michael addition/cycloaddition reaction toward the synthesis of... 

    Magnetic nanoparticles entrapped in the cross-linked poly(imidazole/imidazolium) immobilized Cu(ii): An effective heterogeneous copper catalyst

    , Article RSC Advances ; Volume 4, Issue 87 , 2014 , Pages 46418-46426 ; ISSN: 20462069 Pourjavadi, A ; Hosseini, S. H ; Zohreh, N ; Bennett, C ; Sharif University of Technology
    2014
    Abstract
    Anchoring of copper sulfate in layered poly(imidazole-imidazolium) coated magnetic nanoparticles provided a highly stable, active, reusable, high loading, and green catalyst for the click synthesis of 1,2,3-triazoles via a one-pot cycloaddition of alkyl halide, azide, and alkyne (Cu-A3C). The catalyst was characterized by FTIR, TGA, TEM, SEM, XRD, EDAX, VSM and AAS. High selectivity, broad diversity of alkyl/benzyl bromide/chloride and alkyl/aryl terminal alkynes, and good to excellent yields of products were obtained using 0.7 mol% catalyst. The catalyst was readily recovered and reused up to 6 times without significant loss of activity  

    Process optimization and modeling of heavy metals extraction from a molybdenum rich spent catalyst by aspergillus niger using response surface methodology

    , Article Journal of Industrial and Engineering Chemistry ; Volume 18, Issue 1 , January , 2012 , Pages 218-224 ; 1226086X (ISSN) Mafi Gholami, R ; Mousavi, S. M ; Borghei, S. M ; Sharif University of Technology
    2012
    Abstract
    The present study examines the biorecovery of heavy metals from a spent refinery catalyst obtained from one of the oil refineries in Iran using Aspergillus niger. Bioleaching experiments were carried out in batch cultures using A. niger in the one-step process to mobilize Co, Mo and Ni from hazardous spent catalysts. Response surface methodology (RSM) was applied for the design and analysis of experiments with the optimization of pH, temperature, inoculum percentage, pulp density and rotation speed during the bioleaching of the metals. Experiments were designed as per the central composite design (CCD) technique. Three cubic mathematical models were derived for prediction of the responses.... 

    Heavy metals recovery from spent catalyst using acidithiobacillus ferrooxidans and acidithiobacillus thiooxidans

    , Article ICCCE 2010 - 2010 International Conference on Chemistry and Chemical Engineering, Proceedings, 1 August 2010 through 3 August 2010, Kyoto ; 2010 , Pages 331-335 ; 9781424477647 (ISBN) Mafi Gholami, R ; Borghei, S. M ; Mousavi, S. M ; Sharif University of Technology
    2010
    Abstract
    In this investigation, a spent processing catalyst from one of the oil refineries in Iran was initially characterized physically and chemically. Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans were used to mobilize aluminum, cobalt, molybdenum and nickel from hazardous spent catalysts. Bioleaching experiments were performed in batch cultures. The growth characteristics of the bacteria (pH, Eh, cell concentration and ferrous and ferric iron concentration) were determined during bioleaching along with the concentration of metal values extracted from the catalyst. The results obtained from Inductive coupled plasma-optical emission spectrometry (ICP-OES) showed that after the... 

    Efficiency-effectiveness assessment of national innovation systems: comparative analysis

    , Article Journal of Science and Technology Policy Management ; 2021 ; 20534620 (ISSN) Bakhtiar, A ; Ghazinoory, S. S ; Aslani, A ; Mafi, V ; Sharif University of Technology
    Emerald Group Holdings Ltd  2021
    Abstract
    Purpose: The purpose of this paper is to present and evaluate the performance of innovation systems by considering two indicators of efficiency and effectiveness. The scope of the evaluation is globally and due to the situation of each country, the suggested strategies are proposed to maintain the status quo or move toward the desired situation for countries. Design/methodology/approach: The approach is to compare and benchmark the countries in terms of the efficiency and effectiveness of their innovation system. The Global Innovation Index report’s input-to-output ratio and the global competitiveness report are used for the assessment. Findings: The findings indicate that countries such as... 

    Efficiency-effectiveness assessment of national innovation systems: comparative analysis

    , Article Journal of Science and Technology Policy Management ; Volume 13, Issue 3 , 2022 , Pages 625-651 ; 20534620 (ISSN) Bakhtiar, A ; Ghazinoory, S. S ; Aslani, A ; Mafi, V ; Sharif University of Technology
    Emerald Group Holdings Ltd  2022
    Abstract
    Purpose: The purpose of this paper is to present and evaluate the performance of innovation systems by considering two indicators of efficiency and effectiveness. The scope of the evaluation is globally and due to the situation of each country, the suggested strategies are proposed to maintain the status quo or move toward the desired situation for countries. Design/methodology/approach: The approach is to compare and benchmark the countries in terms of the efficiency and effectiveness of their innovation system. The Global Innovation Index report’s input-to-output ratio and the global competitiveness report are used for the assessment. Findings: The findings indicate that countries such as... 

    Synthesis & Properties of Nd-doped Glass-ceramics in the SiO2-CaO-MgO System from Sol-gel Method Used as Solid Lasers

    , M.Sc. Thesis Sharif University of Technology Eslami, Masoud (Author) ; Hamnabard, Zohreh (Supervisor) ; Nemati, Ali (Supervisor)
    Abstract
    In this study, SiO2-CaO-MgO galsses and glass-ceramic powder doped with Nd3+ were synthesized with sol-gel method. Tetraethylorthosilicate (TEOS), Ca(NO3)2.4H2O, Mg(NO3)2.6H2O, Nd(NO3)3.6H2O, ethanol, distilled water, and HNO3 were used as starting materials. The synthesized powder’s properties were examined with STA, XRD, DRS, PL, FTIR and SEM analysis. From XRD patterns of glass samples, the role of dopant was introduced as intermediate oxide in glass matrix. The XRD patterns of glass-ceramic samples indicated that the bredigite and akermanite crystals were formed in glass matrix. The band gap energy of samples were calculated from DRS analysis and were seen with increasing the dopant... 

    Design and Simulation of CMOS Based Magnetic Sensor for Biosensing Applications

    , M.Sc. Thesis Sharif University of Technology Mafi, Alireza (Author) ; Akbari, Mahmood (Supervisor) ; Fotowat-Ahmady, Ali (Supervisor)
    Abstract
    This paper presents a scalable and ultrasensitive magnetic biosensing scheme based on on-chip LC resonance frequency-shifting. The sensor transducer gain is demonstrated as being location-dependent on the sensing surface and proportional to the local polarization magnetic field strength |B|2 generated by the sensing inductor. To improve the gain uniformity, a periodic coil is proposed as a substitution for the standard process coil. As an implementation example, the circuit is designed in a 65nm CMOS process. The spatially uniform sensor gain of the array is verified by COMSOL simulations. Overall, the presented sensor demonstrates an improvement in the uniformity of the inductor’s magnetic... 

    Immobilized copper(II) on nitrogen-rich polymer-entrapped Fe3O4 nanoparticles: A highly loaded and magnetically recoverable catalyst for aqueous click chemistry

    , Article Applied Organometallic Chemistry ; Volume 30, Issue 2 , 2016 , Pages 73-80 ; 02682605 (ISSN) Zohreh, N ; Hosseini, S. H ; Pour Javadi, A ; Bennett, C ; Sharif University of Technology
    John Wiley and Sons Ltd  2016
    Abstract
    A heterogeneous magnetic copper catalyst was prepared via anchoring of copper sulfate onto multi-layered poly(2-dimethylaminoethyl acrylamide)-coated magnetic nanoparticles and was characterized using various techniques. The catalyst was found to be active, effective and selective for one-pot three-component reaction of alkyl halide, sodium azide and alkyne, known as copper-catalyzed click synthesis of 1,2,3-triazoles. As little as 0.3 mol% of catalyst was found to be effective under the optimum conditions. The catalyst could also be recycled and reused up to seven times without significant loss of activity. Thermal stability, high loading level of copper on catalyst, broad diversity of... 

    Covalent immobilization of cellulase using magnetic poly(ionic liquid) support: improvement of the enzyme activity and stability

    , Article Journal of Agricultural and Food Chemistry ; Volume 66, Issue 4 , 2018 , Pages 789-798 ; 00218561 (ISSN) Hosseini, H ; Hosseini, A ; Zohreh, N ; Yaghoubi, M ; Pourjavadi, A ; Sharif University of Technology
    American Chemical Society  2018
    Abstract
    A magnetic nanocomposite was prepared by entrapment of Fe3O4 nanoparticles into the cross-linked ionic liquid/epoxy type polymer. The resulting support was used for covalent immobilization of cellulase through the reaction with epoxy groups. The ionic surface of the support improved the adsorption of enzyme, and a large amount of enzyme (106.1 mg/g) was loaded onto the support surface. The effect of the presence of ionic monomer and covalent binding of enzyme was also investigated. The structure of support was characterized by various instruments such as FT-IR, TGA, VSM, XRD, TEM, SEM, and DLS. The activity and stability of immobilized cellulase were investigated in the prepared support. The... 

    Rating EFL Learner's Interlanguag Pragmatic Competence by Native and Non-native English Speaking Teachers

    , M.Sc. Thesis Sharif University of Technology Rezanejad, Atefeh (Author) ; Alemi, Minoo (Supervisor) ; Eslami Rasekh, Zohreh (Co-Advisor)
    Abstract
    Pragmatic assessment and consistency in rating are among the subject matters which are still in need of more in-depth investigations. The significance of the issue is highlighted when remembering that inconsistency in ratings would surely damage the test fairness issue in assessment and lead to much diversity in ratings. The purpose of this study was investigating the criteria that native (American) and non-native (Iranian) English speaking teachers considered while rating the pragmatic productions of Iranian EFL learners regarding the two speech acts of compliment and compliment response. Overall, a hundred and twenty teachers (sixty native and sixty non-native raters) participated in this... 

    Multi-variable Optimization of Vehicle Seat Suspension Considering Human Body Model Using Spring-Damper Isolators and Genetic Algorithm

    , M.Sc. Thesis Sharif University of Technology Mafi Shourestani, Farid (Author) ; Moradi, Hamed (Supervisor) ; Vossoughi, Gholamreza (Supervisor)
    Abstract
    In recent years, the seat suspension system in commercial vehicles, industry, agriculture, transportation and … have been focused by researchers. Designing the spring-damper isolators for vehicle’s seat can be an achievable and suitable strategy to increase the comfort and decrease the risk of injuries in vehicles. In this research, the effect of vibrations due to road roughness has been examined by dynamic modeling of a vehicle in combination with the human body model. Thus by using spring-damper isolators and genetic algorithm, we try to optimize the performance of the system. Designing parameters includes the stiffness and viscosity of seat isolator and our target functions include the... 

    Immobilized tungstate on magnetic poly(2-ammonium ethyl acrylamide): A high loaded heterogeneous catalyst for selective oxidation of sulfides using H2O2

    , Article Journal of Industrial and Engineering Chemistry ; Volume 44 , 2016 , Pages 73-81 ; 1226086X (ISSN) Zohreh, N ; Hosseini, S. H ; Pourjavadi, A ; Soleyman, R ; Bennett, C ; Sharif University of Technology
    Korean Society of Industrial Engineering Chemistry  2016
    Abstract
    A heterogeneous tungstate-based catalyst has been prepared for selective oxidation of sulfides to sulfoxides in the presence of 30% H2O2. The catalyst was prepared via immobilization of high amounts of WO4 2− onto the cross-linked poly(ammonium ethyl acrylamide) coated magnetic nanoparticles (MNP). FT-IR, TEM, TGA, VSM, XRD, EDX, and CHN analysis were used for characterization of catalyst. Variety of sulfides successfully converted to the related sulfoxides using 1 mol% of catalyst at room temperature in high yields. The catalyst was easily recovered and reused up to 6 times without loss of activity  

    Tungstate-loaded triazine-based magnetic poly(Bis-imidazolium ionic liquid): An effective bi-functional catalyst for tandem selective oxidation/Knoevenagel condensation in water

    , Article Polymer (United Kingdom) ; Volume 112 , 2017 , Pages 342-350 ; 00323861 (ISSN) Zohreh, N ; Tavakolizadeh, M ; Hosseini, S. H ; Pourjavadi, A ; Bennett, C ; Sharif University of Technology
    Elsevier Ltd  2017
    Abstract
    A novel bi-functional polymeric catalyst was synthesized by immobilization of tungstate anions onto the nitrogen rich poly(ionic liquid)/magnetic nanocomposite. The resulting catalyst has two types of catalytic sites: (i) immobilized WO4 anions with bis-imidazolium ionic liquid cation for selective oxidation of alcohols and (ii) basic amine groups for Knoevenagel condensation between produced aldehyde and malononitrile. Due to the polymeric nature of the catalyst, large amounts of tungstate and basic nitrogen groups were presented on the solid surface which led to a decrease in the applied catalyst mass for catalytic reaction. High catalytic activity and excellent selectivity of catalyst in...