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    Nitrogen removal from high organic loading wastewater in modified Ludzack-Ettinger configuration MBBR system

    , Article Water Science and Technology ; Volume 72, Issue 8 , October , 2015 , Pages 1274-1282 ; 02731223 (ISSN) Torkaman, M ; Borghei, S. M ; Tahmasebian, S ; Andalibi, M. R ; Sharif University of Technology
    IWA Publishing  2015
    Abstract
    A moving bed biofilm reactor with pre-denitrification configuration was fed with a synthetic wastewater containing high chemical oxygen demand (COD) and ammonia. By changing different variables including ammonium and COD loading, nitrification rate in the aerobic reactor and denitrification rate in the anoxic reactor were monitored. Changing the influent loading was achieved via adjusting the inlet COD (956-2,096 mg/L), inlet ammonium (183-438 mg/L), and hydraulic retention time of the aerobic reactor (8, 12, and 18 hours). The overall organic loading rate was in the range of 3.60-17.37 gCOD/m2·day, of which 18.5-91% was removed in the anoxic reactor depending on the operational conditions.... 

    Influence of ultrasonic cell disintegration on excess sludge reduction in a Moving Bed Biofilm Reactor (MBBR)

    , Article Journal of Environmental Chemical Engineering ; Volume 7, Issue 2 , 2019 ; 22133437 (ISSN) Tahmasebian, S ; Borghei, S. M ; Torkaman, M ; Hasani Goudarzi, H ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    Sludge handling is a common issue in all biological wastewater treatment methods. In this study, sonication technique as a state-of-the-art technology has been applied to a continuous MBBR system with the aim of sludge reduction. A novel configuration of MBBR with an additional recycle stream of sonicated sludge was used as the experimental setup. Based on exposed energy and sludge disruption performance, optimized sonication density and exposure time were obtained 1.5 W/mL and 15 min, respectively. This condition provided 42.2% increase in soluble COD as a result of sludge disintegration. Our results revealed that the performance of MBBR and excess sludge reduction were affected by... 

    A Logic For Ambient Intelligence

    , M.Sc. Thesis Sharif University of Technology Torkaman, Maryam (Author) ; Izadi, Mohammad (Supervisor)
    Abstract
    Monitoring of activities of elderly and intelligent decisions about their living environment is a key challenge in smart environments. In the case of such challenges, correctness of system performance is highly dependent on how the model is designed. In the ambient intelligence (AMI) modeling, formal modeling is one of the best approaches because it supports certainty. In addition, time, location and mobility in AMI are crucial requirements, particularly in emergency treatment services. Ambient calculus is a formalism for describing mobility, process migration and message transfer, but it cannot express metric time duration. In this paper we propose an extension of ambient calculus with time... 

    , M.Sc. Thesis Sharif University of Technology Torkaman, Mojtaba (Author) ; Borgheei, Mahdi (Supervisor)
    Abstract
    Removing nitrogen, as one the most surface and ground water contaminant is very important and in order to achieve this aim,nitrification and denitrification are effective and economical methods. In this work, moving bed biofilm reactor (MBBR) with initial denitrification structure, adapted from modified LUDZACK-ETTINGER (MLE) method used in order to industrial wastewater treatment with COD value in range of 900-2100 mg/lit and ammonium in range of 150-430 mg/lit in 3 hydrolic retention time of 18 , 12 and 8 hours.Aerobic reactor volume is 14.4 liter and anoxic reactor volume is 7.2 liter and reflux flow amount from aerobic reactor to anoxic reactor has considered being 3 times of anoxic... 

    Removal of BTX compounds from wastewaters using template free MFI zeolitic membrane

    , Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 29, Issue 4 , 2010 , Pages 91-98 ; 10219986 (ISSN) Torkaman, R ; Kazemian, H ; Soltanieh, M ; Sharif University of Technology
    2010
    Abstract
    MFI zeolite membranes were prepared on porous α-alumina substrates, using secondary growth of nano-seeded layers. The resulting membranes were characterized by means of Scanning Electron Microscopy (SEM), X-Ray Diffractometry (XRD), and pervaporation performance tests for separation of Benzene, Toluene and Xylene (BTX) mixture from contaminated water. The morphology, thickness, homogeneity, crystal preferential orientation and permeation properties of these membranes have been studied in relation to the seed layers. Successful separation of BTX mixture from water was performed by using the manufactured MFI zeolite membrane. The influence of temperature, feed concentration on the membrane... 

    Atomistic simulations of mechanical properties and fracture of graphene: A review

    , Article Computational Materials Science ; Volume 210 , 2022 ; 09270256 (ISSN) Torkaman Asadi, M. A ; Kouchakzadeh, M. A ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    Material properties and fracture characteristics are among the most prominent parameters that should be considered for a wide range of graphene applications. This article reviews recent advances in theoretical studies on the mechanical properties and fracture behaviors of graphene, focusing on the effect of various simulation models. Most studies investigated single-layer graphene sheets (SLGSs) under uniaxial tensile tests using different common interatomic potentials, particularly AIREBO. Although researchers have examined a similar problem, specifically for pristine graphene, the differences in the reported values are considerable. These discrepancies are most evident in fracture... 

    Precise Cosmology with Redshift Space Distortion and Calculating Pecular Velocity of SNe type Ia

    , M.Sc. Thesis Sharif University of Technology Torkaman Gholami, Ali Hossein (Author) ; Baghram, Shant (Supervisor)
    Abstract
    The distance measurement is the corner stone of the modern cosmology. They are measured via ”Doppler Effect”, accordingly the distances in cosmology are obtained in red-shift space. Despite the cosmological background expansion, the peculiar velocities due to the local density contrast distort these measurements. One of the main challenges in upcoming cosmological studies is to distinguish the peculiar velocity effect from the background expansion.Supernova Type Ia as standard candles can be think of a crucial observation to address the above problem. In this thesis, we study the effect of cosmological perturbations on distance-redshift relation of the SNIa. The corrective effects are from weak... 

    Free vibration analysis of cylindrical shells partially resting on an elastic foundation

    , Article Meccanica ; Volume 51, Issue 5 , 2016 , Pages 1113-1125 ; 00256455 (ISSN) Torkaman Asadi, M. A ; Firouz Abadi, R. D ; Sharif University of Technology
    Springer Netherlands  2016
    Abstract
    The present study aims at the investigation of free vibration analysis of thin cylindrical shells surrounded by an elastic medium, which is distributed over a particular length of the shell. The Love’s shell theory is utilized along with the Winkler foundation to obtain the governing equations of motion. An exact series expansion method of solution is employed for any arbitrary boundary conditions. The excellent accuracy of the obtained results is validated by comparing to the available literature. Moreover, several case studies are performed to provide an insight into the influence of some practically important parameters on free vibrations of circular cylindrical shells, including... 

    Productivity Improvement Management Cycle at the Deeds and Properties Registration Org. of Tehran Province

    , M.Sc. Thesis Sharif University of Technology Torkaman, Masoud (Author) ; Eshragh Nia Jahromi, Abdol Hamid (Supervisor)
    Abstract
    Organizations are established and developed based on a specific existence policy. They would exist as long as they are able to do their basic mission. An organization could perform its mission through some work processes. The better processes makes higher organization’s productivity. In order words desirable quality and quantity of an organization depends on processing functions. Improved processes use minimum resources to achieve efficiency maximum. Deeds and Properties Registration Org. (DPRO) is a unit, which maintains and supports national security through arranging individual social and economic relations, the organization has an outstanding position. Following composition of 20-year... 

    Free vibrations and stability of high-speed rotating carbon nanotubes partially resting on Winkler foundations

    , Article Composite Structures ; Volume 126 , 2015 , Pages 52-61 ; 02638223 (ISSN) Torkaman Asadi, M. A ; Rahmanian, M ; Firouz-Abadi, R. D ; Sharif University of Technology
    Elsevier Ltd  2015
    Abstract
    In the present study, free vibrations and stability of rotating single walled carbon nanotubes (SWCNT) is investigated by nonlocal theory of elasticity; while the CNT is partially resting on an elastic foundation. The governing equations of motion are presented by using Love's shell assumptions. An exact series expansion method of solution is employed and very accurate results are obtained. Some parameter studies including the effects of rotating speed, foundation stiffness, slenderness ratio and nonlocal parameter on the natural frequency and stability margins of the current model are studied. The studies show that rotation rates and foundation elasticity can contribute significantly in the... 

    Solving a production-routing problem with price-dependent demand using an outer approximation method

    , Article Computers and Operations Research ; Volume 123 , 2020 Torkaman, S ; Akbari Jokar, M. R ; Mutlu, N ; Van Woensel, T ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    A production-routing problem with price-dependent demand (PRP-PD) is studied in this paper. Demand follows a general convex, differentiable, continuous and strictly decreasing function in price. The problem is modeled as a mixed integer nonlinear program (MINLP). Two Outer Approximation (OA) based algorithms are developed to solve the PRP-PD. The efficiency of the proposed algorithms in comparison with commercial MINLP solvers is demonstrated. The computational results show that our basic OA algorithm outperforms the commercial solvers both in solution quality and in computational time aspects. On the other hand, our extended (two-phase) OA algorithm provides near-optimal solutions very... 

    Reactive extraction evaluation for vanadium (V) removal in the MRDC column using axial dispersion and central composition approach

    , Article Korean Journal of Chemical Engineering ; Volume 39, Issue 12 , 2022 , Pages 3399-3411 ; 02561115 (ISSN) Shakib, B ; Asadollahzadeh, M ; Outokesh, M ; Torkaman, R ; Torab Mostaedi, M ; Sharif University of Technology
    Springer  2022
    Abstract
    Reactive extraction development was investigated to extract vanadium ions from sulfate solution in the modified rotating disc column (MRDC). It was found from batch experiments that D2EHPA and TBP concentrations, initial aqueous phase pH, and the concentration of NH4OH as a stripping agent were optimized equal to 0.3 M, 0.36 M, 2, and 1 M, respectively. In the continuous experiments, the effects of rotor speed, aqueous and organic phase flow rates, and mass transfer direction were investigated on the dispersed phase holdup, mass transfer coefficients, and vanadium extraction. The experiment design was based on the response surface design to analyze the dependence of responses with the input... 

    Fracture Analysis of Graphene Using Peridynamic Theory

    , Ph.D. Dissertation Sharif University of Technology Torkaman Asadi, Mohammad Ali (Author) ; Kouchakzadeh, Mohammad Ali (Supervisor)
    Abstract
    The aim of this research is to analyze the failure and investigate crack growth in graphene using peridynamic theory. The presence of spatial partial derivatives in the equations of classical continuum mechanics has led to the fact that methods based on this theory are not valid in displacement discontinuities such as cracks. Peridynamic theory emerges as a nonlocal reformulation of mechanics, uniquely well-suited for modeling discontinuities and dynamic fractures in both continuous and discrete media. Its adaptability extends to various dimensions, encompassing phenomena at the nanoscale. In the present study, based on the ordinary state-based peridynamic theory, we investigated the... 

    Experimental study and correlation for mass transfer coefficient in the pilot plant multistage column with the presence of molybdenum

    , Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 41, Issue 2 , 2022 , Pages 544-554 ; 10219986 (ISSN) Shakib, B ; Torab Mostaedi, M ; Outokesh, M ; Torkaman, R ; Asadollahzadeh, M ; Sharif University of Technology
    Iranian Institute of Research and Development in Chemical Industries  2022
    Abstract
    In the present work, multistage extraction column performance for reactive separation of molybdenum from the leach aqueous phase by using D2EHPA and TBP in kerosene was investigated by using the axial diffusion model. The variation of volumetric overall mass transfer coefficients based on continuous phases at various operating conditions was obtained. By considering the chemical reaction conditions, the experimental data indicate that the volumetric overall mass transfer coefficients increase with an enhancement in rotor speed and continuous and dispersed phase flow rates. According to the sensitivity analysis, the rotor speed and flow rate of the dispersed phase have more influence on... 

    Comparing Two orthoses for managing medial knee osteoarthritis: lateral wedge with subtalar strap while barefoot versus lateral wedged insole fitted within sandal

    , Article Indian Journal of Orthopaedics ; Volume 56, Issue 2 , 2022 , Pages 319-326 ; 00195413 (ISSN) Falahatgar, M ; Jalali, M ; Babaee, T ; Safaeepour, Z ; Torkaman, A ; Baniasad, M ; Sharif University of Technology
    Springer  2022
    Abstract
    Background: Using foot orthoses for managing medial knee osteoarthritis (MKOA) is common, although its effectiveness is in debate. Most orthoses are placed inside the shoe as a lateral wedged insole. Thus, most studies in this area have focused on the effect of insoles used with shoes. This study compared the effects of a lateral wedge with subtalar strap (combined insole) used while barefoot and lateral wedged insole fitted within sandal on pain, function and external knee adduction moment (EKAM) in patients with MKOA to consider which orthotic treatment is better. Methods: In this quasi-experimental pretest–posttest study, 29 participants with medial knee osteoarthritis were divided into... 

    Comparing two orthoses for managing medial knee osteoarthritis: lateral wedge with subtalar strap while barefoot versus lateral wedged insole fitted within sandal

    , Article Indian Journal of Orthopaedics ; 2021 ; 00195413 (ISSN) Falahatgar, M ; Jalali, M ; Babaee, T ; Safaeepour, Z ; Torkaman, A ; Baniasad, M ; Sharif University of Technology
    Springer  2021
    Abstract
    Background: Using foot orthoses for managing medial knee osteoarthritis (MKOA) is common, although its effectiveness is in debate. Most orthoses are placed inside the shoe as a lateral wedged insole. Thus, most studies in this area have focused on the effect of insoles used with shoes. This study compared the effects of a lateral wedge with subtalar strap (combined insole) used while barefoot and lateral wedged insole fitted within sandal on pain, function and external knee adduction moment (EKAM) in patients with MKOA to consider which orthotic treatment is better. Methods: In this quasi-experimental pretest–posttest study, 29 participants with medial knee osteoarthritis were divided into... 

    An overview of sustainable energy development by using cogeneration technology and opportunity for improving process

    , Article International Journal of Energy Research ; 2020 Salehi, A. A ; Ghannadi Maragheh, M ; Torab Mostaedi, M ; Torkaman, R ; Asadollahzadeh, M ; Sharif University of Technology
    John Wiley and Sons Ltd  2020
    Abstract
    Nowadays, energy supply is one of the most prominent demands of countries in the world. The enhancement in energy efficiency, flexibility for applications in various industrial processes, and the reduction in the environmental impacts of pollutant emissions can be accomplished by using sustainable energy sources. Alternative procedures for heat and electricity production have been developed in the commercial and industrial sectors and focusing on the cogeneration systems, and the contribution of nuclear energy has been increased for improving processes. Nuclear reactors play an essential role in nonelectric applications, and combined heat and energy at different operating temperatures can be... 

    Hydrogel materials as an emerging platform for desalination and the production of purified water

    , Article Separation and Purification Reviews ; 2020 , Pages 1-20 Salehi, A. A ; Ghannadi Maragheh, M ; Torab Mostaedi, M ; Torkaman, R ; Asadollahzadeh, M ; Sharif University of Technology
    Taylor and Francis Inc  2020
    Abstract
    Water is the most abundant liquid on Earth, but only 2.5% of worldwide water are fresh. It is impossible to ignore the importance of water in almost every process on Earth, from the smallest bacteria life to the formation of the continents. Today, efforts for the desalination of seawater and brackish water are critical to produce drinking water. In recent years, a novel material: hydrogel, was considered in desalination processes. Interesting hydrogel applications were proposed for forward osmosis desalination, solar still, electrodialysis, and capacitive desalination. Simple and inexpensive desalination ways for drinking water production are needed. Hydrogel compounds are one of the leading... 

    A review on the water-energy nexus for drinking water production from humid air

    , Article Renewable and Sustainable Energy Reviews ; Volume 120 , 2020 Salehi, A. A ; Ghannadi Maragheh, M ; Torab Mostaedi, M ; Torkaman, R ; Asadollahzadeh, M ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    The Supply of sustainable freshwater has turned into a fundamental problem in numerous countries. The increment in population, the industrialization of the world, and variation in global warming temperatures lead to an increase in droughts, storms, and floods around the world. Therefore, the problems of water scarcity appear worldwide. Contrary to popular belief, the largest reserves of water are available in the air. Accordingly, several technologies have been developed for the production of drinking water from humid air in the research works. But, the critical problem is the high energy consumption in this equipment. Therefore, the issues of water-energy nexus are the particular subject in... 

    An overview of sustainable energy development by using cogeneration technology and opportunity for improving process

    , Article International Journal of Energy Research ; Volume 45, Issue 8 , 2021 , Pages 11423-11439 ; 0363907X (ISSN) Salehi, A. A ; Ghannadi Maragheh, M ; Torab Mostaedi, M ; Torkaman, R ; Asadollahzadeh, M ; Sharif University of Technology
    John Wiley and Sons Ltd  2021
    Abstract
    Nowadays, energy supply is one of the most prominent demands of countries in the world. The enhancement in energy efficiency, flexibility for applications in various industrial processes, and the reduction in the environmental impacts of pollutant emissions can be accomplished by using sustainable energy sources. Alternative procedures for heat and electricity production have been developed in the commercial and industrial sectors and focusing on the cogeneration systems, and the contribution of nuclear energy has been increased for improving processes. Nuclear reactors play an essential role in nonelectric applications, and combined heat and energy at different operating temperatures can be...