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A trace-time framework for prediction of elevation angle over land mobile LEO satellites networks
, Article Wireless Personal Communications ; Volume 62, Issue 4 , February , 2012 , Pages 793-804 ; 09296212 (ISSN) ; Rahimi, F ; Sharif University of Technology
2012
Abstract
Elevation angle is one of the most significant parameters of land mobile satellite channels, subject to rapid variations in the case of Low Earth Orbit (LEO) satellite systems. In this paper a novel trace-based framework is proposed and analyzed which is capable of predicting elevation angle as a function of time during satellite visibility window. Trace-time based modeling makes the framework practical for real-time evaluation of elevation angle and its alteration incurred by communication links in LEO satellite systems. The proposed method is particularly suitable for development of communication channel models and services in mobile LEO satellite networks where path variability is of...
Erratum: A trace-time framework for prediction of elevation angle over land mobile LEO satellites networks (Wireless Personal Communications DOI 10.1007/s11277-010-0094-5)
, Article Wireless Personal Communications ; Volume 62, Issue 4 , February , 2012 , Pages 805-806 ; 09296212 (ISSN) ; Rahimi, F ; Sharif University of Technology
2012
Identification And Assessment of Major Risks Associated with Heavy Equipment Transportation in Iranian Oil, Gas and Petrochemical Projects
, M.Sc. Thesis Sharif University of Technology ; Eslami, Hossein (Supervisor)
Abstract
Transportation of heavy and super heavy equipment is one of the issues that have been discussed in recent years. High cost and required expertise of Transportation for oil and gas projects has caused many organizations and Iranian companies turn to outsourcing strategy and have invested a lot of money in this field without regard to its Risks. Unfortunately, the lack of risk management in transportation projects has led to an increase in refractive index. In this thesis, have been identified the risks of heavy and super-heavy transport equipment in the oil, gas and petrochemical industries then prioritize the risks identified. Finally, each of the identified risks in Iran is investigated....
Explanation of Policy Process for the Legislative Bill to Establish Free Trade, Industrial and Special Economic Zones in 2018 in Iran
, M.Sc. Thesis Sharif University of Technology ; Maleki, Ali (Supervisor)
Abstract
Understanding and interpreting the process that policy goes through from the agenda-setting stage to the implementation and evaluation stages have many difficulties and complexities. One way to facilitate the understanding of this process is to use theories that explain the policy process. The purpose of this research is to explain the process that has passed through the legislative bill of eight free trade zones and one hundred and three special economic zones in Iran in 2018. To reach this goal using two theories of Multiple Streams Analysis (MSA) and the Advocacy Coalition Framework (ACF).Due to the nature and aims of this research, the qualitative approach and case study method have been...
The Rate of Fields’ Variations Toward the Distance of Two Horizons in Dilatonic Black Holes and its Relation With Time, Near the Extremality
, M.Sc. Thesis Sharif University of Technology ; Arfaei, Hessamaddin (Supervisor)
Abstract
Among the various types of black holes, dilatonic black holes can be mentioned which are in the center point of view at their extremality. In this study, we pay attention to these answers and their fields and the way they behave variously, especially when the coupling constant α is between 0and1. For doing so, in chapter one we attempt to study one of the simplest answers in General Relativity (Schwarzschild) and some beginning contexts. Then in chapter two, we try another answer (Reissner Nordstrom) which contains non-Extremal and Extremal states. In chapter three we introduce the concept of the higher theories. Chapter four is a hint about hawking radiation. And finally in chapter five, we...
The effect of HRT and carriers on the sludge specifications in MBR to remove VOCs from petrochemical wastewater
, Article Desalination and Water Treatment ; Volume 57, Issue 46 , 2016 , Pages 21730-21742 ; 19443994 (ISSN) ; Shayegan, J ; Mojtaba Seyedi, S ; Sharif University of Technology
Taylor and Francis Inc
2016
Abstract
This work employs two membrane bioreactors (with and without carrier) to evaluate the influence of carrier and hydraulic retention time (HRT) on the sludge specifications when removing organic volatile compounds (e.g. styrene and ethylbenzene) from petrochemical wastewater. This study is conducted during three various HRTs. The results indicate that the optimum HRT (e.g. 15 h.) was achieved in the reactor with carrier during biological removal and membrane fouling minimization. During the optimum HRT, the biological removal efficiency for styrene, ethylbenzene, and COD is 99.8 ± 0.1%, 99.8 ± 0.1%, and 99 ± 0.8%, respectively, and the concentration of styrene and ethylbenzene in the exit air...
Biodegradation kinetics and interactions of styrene and ethylbenzene as single and dual substrates for a mixed bacterial culture
, Article Journal of Environmental Health Science and Engineering ; 2015 ; 2052336X (ISSN) ; Shayegan, J ; Seyedi, S. M ; Sharif University of Technology
BioMed Central Ltd
2015
Abstract
This study examined biodegradation kinetics of styrene and ethylbenzene as representatives of alkenylbenzenes and mono-alkylbenzenes, respectively. The compounds were studied independently and as binary mixtures using a series of aerobic batch degradation experiments introduced by acclimatized mix culture. Initial concentration of styrene and ethylbenzene in the liquid phase vacillated from 0 to 220 mg/l. The Andrew model was applied for the biodegradation of individual substrates and the estimated constants of the equation for styrene and ethylbenzene were μmax = 0.1581, 0.2090 (1/h), KS =25.91, 37.77 (mg/L), KI =13.15, 62.62 (mg/L), respectively. The accomplished parameters from single...
The effect of HRT and carriers on the sludge specifications in MBR to remove VOCs from petrochemical wastewater
, Article Desalination and Water Treatment ; Dec , 2015 , Pages 1-13 ; 19443994 (ISSN) ; Shayegan, J ; Mojtaba Seyedi, S ; Sharif University of Technology
Taylor and Francis Inc
2015
Abstract
This work employs two membrane bioreactors (with and without carrier) to evaluate the influence of carrier and hydraulic retention time (HRT) on the sludge specifications when removing organic volatile compounds (e.g. styrene and ethylbenzene) from petrochemical wastewater. This study is conducted during three various HRTs. The results indicate that the optimum HRT (e.g. 15 h.) was achieved in the reactor with carrier during biological removal and membrane fouling minimization. During the optimum HRT, the biological removal efficiency for styrene, ethylbenzene, and COD is 99.8 ± 0.1%, 99.8 ± 0.1%, and 99 ± 0.8%, respectively, and the concentration of styrene and ethylbenzene in the exit air...
An extended Markov model to determine the reliability of protective system
, Article 2006 IEEE Power India Conference, New Delhi, 10 April 2006 through 12 April 2006 ; Volume 2005 , 2005 , Pages 428-432 ; 0780395255 (ISBN); 9780780395251 (ISBN) ; Fotuhi, M ; Sanaye Pasand, M ; Sharif University of Technology
2005
Abstract
In this paper a reliability model for power transformer protection is proposed. The model is an extension of a previously proposed Markov model for transmission line protection. Optimum routine test and self checking intervals of the power transformer protection system are determined using the extended Markov model. © 2006 IEEE
Evaluate the kinetic of Containment Removal and Improving the Effect of the Biological Factors on Membrane Bio Reactors and Fouling Problem
, M.Sc. Thesis Sharif University of Technology ; Shaygan SaleK, Jalaloddin (Supervisor)
Abstract
In this study as representatives of alkenylbenzenes and mono-alkylbenzenes respectively were considered individually and as binary mixtures. It was observed that styrene, and ethyl benzene were inhibitory types of substrates across the tested concentration ranges. Thus, biodegradation kinetic is well described by the Haldane model. Kinetic parameter's assessments from single substrate degradation tests and these parameters were used to predict possibly interaction factors achieved from dual substrate experiments. The achieved outcomes from mixture of experiments revealed that the ratio of depletion for each substrate is affected by the presence of the other. It was also inferred that ethyl...
A novel method for prediction of parameters of naturally fractured condensate reservoirs using pressure response analysis
, Article Journal of Natural Gas Science and Engineering ; Vol. 19, issue , July , 2014 , p. 13-22 ; ISSN: 18755100 ; Jamshidi, S ; Masihi, M ; Sharif University of Technology
2014
Abstract
Producing from gas condensate reservoirs under dew-point pressure and at constant temperature shows a complex behavior because of existing liquid condensate around the well. Zones with different mobilities generate three zones as a zone away from the well containing only gas, a zone having liquid around the well and finally a zone containing movable oil and gas. Existence of condensate around wellbore reduces gas relative permeability and as a result productivity index of the well will decrease. In fact, this condensate acts like an additional skin and investigating of this behavior can be difficult because of the complex fluid flow processes. Well test analysis in naturally fractured...
Outpatient Appointment Scheduling Problem using Decentralized and Distributed Methods
, Ph.D. Dissertation Sharif University of Technology ; Eshghi, Kourosh (Supervisor) ; Carter, Micheal (Co-Supervisor)
Abstract
The objective of this research is to investigate the complexities and challenges of outpatient appointment scheduling in healthcare systems and to develop an integrated and decentralized scheduling system capable of effectively managing patient appointments across a healthcare system. This study begins with a comprehensive literature review, examining existing scheduling models, sequencing methods, and optimization techniques. It then introduces several optimization models for outpatient appointment scheduling, including scheduling and sequencing for multi-class, multi-priority patients, incorporating patient flexibility in choosing service locations. Patient-based and center-based...
Multi-Target tracking of human spermatozoa in phase-contrast microscopy image sequences using a hybrid dynamic bayesian network
, Article Scientific Reports ; Volume 8, Issue 1 , 2018 ; 20452322 (ISSN) ; Vosoughi Vahdat, B ; Salman Yazdi, R ; Sharif University of Technology
Nature Publishing Group
2018
Abstract
Male infertility is mostly related to semen and spermatozoa, and any diagnosis or treatment requires the investigation of the motility patterns of spermatozoa. The movements of spermatozoa are fast and involve collision and occlusion with each other. In order to extract the motility patterns of spermatozoa, multi-target tracking (MTT) of spermatozoa is necessary. One of the most important steps of MTT is data association, in which the newly arrived observations are used to update the previous tracks. Dynamic Bayesian network (DBN) is a powerful tool for modeling and solving various types of problems such as tracking and classification. There can also be a hybrid-DBN (HDBN), in which both...
Molecular engineering and morphology of polyurethane elastomers containing various molecular weight of macrodiol
, Article Materials Science and Engineering B: Solid-State Materials for Advanced Technology ; Volume 264 , 2021 ; 09215107 (ISSN) ; Zuber, M ; Barikani, M ; Salman, M ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
A series of polyurethane elastomers (PUEs) based on 4,4′-cyclohexamethylene diisocyanate (H12MDI)/1,2-ethanediol as hard segment with the soft segments having different molecular weights of polycaprolactone diols, were effectively polymerized by two step technique. The structural characterization was performed by FT-IR spectroscopy. The X-ray diffraction (XRD) technique was used to study the crystallinity and hydrophilicity of the prepared polymer films. It was found that crystallinity and hydrophilicity increased with increasing the chain length of soft segments. The effect of molecular weight of polyols on the contact angle, water absorption (%) and swelling behavior of the synthesized...
Towards Optimal Convergence Rates For the Quantum Central Limit Theorem
, M.Sc. Thesis Sharif University of Technology ; Beigi, Salman (Supervisor) ; Safdari, Mohammad (Supervisor)
Abstract
The Quantum Central Limit Theorem states that when you convolve a centered quantum state, the resulting sequence of states converges to a Gaussian quantum state with the same first and second moments as the original quantum state. Similar to the classical setting, there are various metrics to measure convergence in the Quantum Central Limit Theorem. In this thesis, we aim to examine this theorem under different metrics such as Quantum Relative Entropy and Trace distance, and to prove tight convergence rates for the Quantum Central Limit Theorem
Computation of armature reaction field and full-load characteristics of an axial flux surface mounted pm machine using a new analytical approach
, Article 26th Iranian Conference on Electrical Engineering, ICEE 2018, 8 May 2018 through 10 May 2018 ; 2018 , Pages 1027-1031 ; 9781538649169 (ISBN) ; Sharifi, A. H ; Abedini Mohammadi, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
In recent years axial flux permanent magnet (AFPM) machines have found industrial applications because of such characteristics as high power density, compact structure and disc-like shape. Like other electrical machines, prediction of flux density distribution in the air gap of AFPM is essential. In this paper, an analytical method for calculation of air gap flux density caused by armature reaction is presented. The solution is based on Maxwell's equations. Separation of variables method is applied to field equations and 2D distribution of magnetic flux density in the air gap calculated in term of Fourier series. The 2-D distribution of three-phase armature winding is modeled exactly....
Cache-Aided interference management in wireless cellular networks
, Article IEEE Transactions on Communications ; Volume 67, Issue 5 , 2019 , Pages 3376-3387 ; 00906778 (ISSN) ; Maddah Ali, M. A ; Salman Avestimehr, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
We consider the problem of interference management in wireless cellular networks with caches at both base stations and receivers, and we characterize the degrees of freedom (DoFs) per cell to within an additive gap of (1/3) and a multiplicative gap of 2 for all system parameters, under one-shot linear schemes. Our result indicates that the one-shot linear DoF per cell scales linearly with the total amount of cache available in the cell, i.e., the sum of the caches at the central base station and all the receivers within the cell, resembling a similar phenomenon previously observed for the case of fully connected wireless networks. To establish the result, we propose a decentralized and...
Pressure Response Analysis of Naturally Fractured Condensate Reservoirs Regarding the Effect of Permeability Anisotropy
, M.Sc. Thesis Sharif University of Technology ; Jamshidi, Saied (Supervisor) ; Masihi, Mohsen (Co-Advisor)
Abstract
Producing from Gas Condensate Reservoirs under dew point pressure and at constant temperature may have a complex behavior because of existing two phase system and liquid around the well. Zones with different mobility generate as a zone away from the well containing only gas, a zone having liquid around the well and finally a zone with capillary effect. Existence of condensate around well reduces gas relative permeability and as a result productivity index of well decreases. In fact these condensate acts like an additional skin and because of some complex processes, investigating of these behaviors can be difficult.
Well testing analysis in Natural Fractured reservoir is generally based...
Well testing analysis in Natural Fractured reservoir is generally based...
Demand Estimation of Natural Gas
, M.Sc. Thesis Sharif University of Technology ; Rahmati, Mohammad Hossein (Supervisor) ; Vesal, Mohammad (Supervisor)
Abstract
The provision of developmental infrastructure by governments and their various effects on the lives of citizens has always been the subject of discussion among researchers and policymakers. In particular, the infrastructure associated with access to modern energies causes changes in household economic behavior. The effects of pipeline gas connection on household behavior is the main subject of this research. By using micro level data, these effects compare the behavior of beneficiary households and lack of natural gas. The data includes households living in the entire geographical zone of Iran and between 1377 and 1394. First, we show that natural gas is a direct substitute for liquid fuels...
Preparation and characterization of PVC/PAN blend ultrafiltration membranes: Effect of PAN concentration and PEG with different molecular weight
, Article Desalination and Water Treatment ; Volume 58 , 2017 , Pages 1-11 ; 19443994 (ISSN) ; Mojtaba Seyedi, S ; Rabiei, H ; Alvandifar, N ; Arya, A ; Sharif University of Technology
Desalination Publications
2017
Abstract
The current study investigates the effect of polyacrylonitrile (PAN) addition on morphology and antifouling properties of poly(vinyl chloride) (PVC) asymmetric flat ultrafiltration (UF) membranes. The membranes are prepared via phase inversion method induced by immersion precipitation at different PVC/PAN blending ratio up to 40 wt% PAN. Also, membranes with blending ratio of PVC/ PAN:70/30, which showed the highest water flux and flux recovery ratio, were used for membrane preparation with 4 wt% of Polyethylene glycol (PEG) addition in four different molecular weight, 600 Da, 1,000 Da, 6,000 Da and 20,000 Da, which was used as pore former and hydrophilic polymeric additive. The performance...