Loading...
Search for:
sotoudeh--mahsa
0.186 seconds
Seismic analysis of a system of dam-massed foundation-reservoir under inclined excitation
, Article JVC/Journal of Vibration and Control ; 2021 ; 10775463 (ISSN) ; Ghaemian, M ; Sharif University of Technology
SAGE Publications Inc
2021
Abstract
One of the acceptable assumptions in engineering practice is vertical propagation of earthquake waves. When the source of earthquake is located very deep in the ground, this assumption is valid, but for sources located in shallow ground, it loses its viability. In this study, linear seismic analysis of a system of concrete dam-massed foundation-reservoir is performed under inclined earthquake excitation. Both P- and SV-type earthquakes are considered for the purpose of the seismic analysis. To consider the effects of inhomogeneous waves for the case of SV wave propagation, post-critical angles are also considered in the analysis. To investigate the effects of earthquake frequency content on...
Seismic analysis of a system of dam-massed foundation-reservoir under inclined excitation
, Article JVC/Journal of Vibration and Control ; Volume 28, Issue 13-14 , 2022 , Pages 1769-1780 ; 10775463 (ISSN) ; Ghaemian, M ; Sharif University of Technology
SAGE Publications Inc
2022
Abstract
One of the acceptable assumptions in engineering practice is vertical propagation of earthquake waves. When the source of earthquake is located very deep in the ground, this assumption is valid, but for sources located in shallow ground, it loses its viability. In this study, linear seismic analysis of a system of concrete dam-massed foundation-reservoir is performed under inclined earthquake excitation. Both P- and SV-type earthquakes are considered for the purpose of the seismic analysis. To consider the effects of inhomogeneous waves for the case of SV wave propagation, post-critical angles are also considered in the analysis. To investigate the effects of earthquake frequency content on...
Seismic analysis of reservoir-gravity dam-massed layered foundation system due to vertically propagating earthquake
, Article Soil Dynamics and Earthquake Engineering ; Volume 116 , 2019 , Pages 174-184 ; 02677261 (ISSN) ; Ghaemian, M ; Mohammadnezhad, H ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Seismic analysis of complex structures such as concrete dams has been the subject of numerous studies. One of the challenges in seismic analysis of such systems is proper modelling of massed foundation. Since concrete dams’ foundations are usually layered, this makes the homogenous half-space assumption relatively unrealistic. In this paper, the effects of massed layered foundation on seismic response of concrete gravity dams in dam-reservoir-foundation systems are investigated. Seismic finite element analysis of the system carried out using domain reduction method. This approach is compared with another available method named, free-field column. First set of analysis considers the effect of...
Seismic analysis of reservoir-gravity dam-massed layered foundation system due to vertically propagating earthquake
, Article Soil Dynamics and Earthquake Engineering ; Volume 116 , 2019 , Pages 174-184 ; 02677261 (ISSN) ; Ghaemian, M ; Mohammadnezhad, H ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Seismic analysis of complex structures such as concrete dams has been the subject of numerous studies. One of the challenges in seismic analysis of such systems is proper modelling of massed foundation. Since concrete dams’ foundations are usually layered, this makes the homogenous half-space assumption relatively unrealistic. In this paper, the effects of massed layered foundation on seismic response of concrete gravity dams in dam-reservoir-foundation systems are investigated. Seismic finite element analysis of the system carried out using domain reduction method. This approach is compared with another available method named, free-field column. First set of analysis considers the effect of...
, M.Sc. Thesis Sharif University of Technology ; Parsafar, Gholamabbas (Supervisor)
Abstract
In 2009, a general equation of state (EOS-III) based on an effective near-neighbor pair interaction of an extended Lennard-Jones (3, 6, 12) type has been introduced as : , where is the compressibility factor, p and ρ stand for pressure and molar density , respectively, T is Temperature , and e, f and g are the temperature dependent coefficient of the equation of state . the Z_th and Z_in are the thermal and internal contributions of pressure in the compressibility factor, respectively. this equation of state gives a good description of all types of nano- and bulk –solid and bulk fluid at entire temperature and pressure ranges for which thee is experimental data. Investigation show that...
Thermal Analysis of Concrete arch Dams Using Real Reservoir Data and Comparing the Results with Stucky-derron Method
, M.Sc. Thesis Sharif University of Technology ; Ghaemian, Mohsen (Supervisor)
Abstract
Thermal analysis of concrete arch dams is always an important issue in designig these enormous concrete structures. The reason this issue mainly concerns arch dams and not gravity dams is because of little thickness of arch dams which makes them prone to cracking due to thermal loading. To solve any thermal problem we need boundary conditions. In arch dam case, these boundaries are the temperature of the upstream and downstream face of the dam which, depending on circumstances, can be in touch with water or air. Estimating air temperature is a fairly easy task when you have monthly mean temperatures. The challenging part is defining water temperature in any depth of the reservoir whenever we...
Analytical and Experimental Modeling and Predicting Chatter Occurrence during Thin-walled Parts Milling
, M.Sc. Thesis Sharif University of Technology ; Movahhedy, Mohammad Reza (Supervisor)
Abstract
Milling of thin-walled parts is a widely used process in aeronautical and automotive industries. Along the milling of these low rigidity parts, large quantities of material are removed using high removal rate conditions with the risk of the instability of the process as the result of chatter vibration. Self-excited chatter vibration is an undesirable phenomenon in all machining processes and many efforts have been made in order to understand its mechanism and deal with its destructive effects. Studying chatter in machining processes with variable dynamics, which this thesis represents an instance of it, has been taken into consideration in the recent years. Most of researches done in this...
Seismic Analysis of Concrete Gravity Dams Considering Layered Foundation Using Domain Reduction Method
, Ph.D. Dissertation Sharif University of Technology ; Ghaemian, Mohsen (Supervisor)
Abstract
Nowadays, due to advancements in technology and processing power, earthquake engineering is moving toward more realistic modeling of actual problems in different fronts. In the case of considering seismic waves for design and analysis of concrete dams, numerous challenges exists due to complex nature of the problem which have absorbed abundant attention from a number of researchers around the world. In recent studies about earthquake input mechanisms, accounting for true nature of the foundation and applied earthquake have been hot topics. Therefore, in this thesis, thorough investigation on these effective factors in dynamic analysis of concrete dams is performed.In the first part of this...
Photoelectrocatalytic Performance of Mesoporous TiO2 Nanostructures Decorated with Cu-Ag-Zn Particles for CO2 Conversion
, M.Sc. Thesis Sharif University of Technology ; Simchi, Abdolreza (Supervisor)
Abstract
The rise in carbon dioxide levels has led to the manifestation of numerous environmental challenges. Currently, the absorption and conversion of carbon dioxide into valuable fuel resources such as synthetic gas, methane, and ethylene are deemed crucial from both environmental and economic standpoints. Despite the presentation of photocatalysts such as titanium oxide and electrocatalysts such as copper, silver, and zinc, their efficiency in CO2 conversion is found to be insufficient. One potential solution to this problem is the utilization of photoelectrocatalytic CO2 recovery. In this study, the aim was to enhance the photoelectrocatalytic reduction of CO2 by designing and manufacturing...
Analysis of Hidden-policy Attribute-based Access Control Schemes for Cloud Environment
, M.Sc. Thesis Sharif University of Technology ; Eghlidos, Taraneh (Supervisor) ; Mohajeri, Javad (Supervisor)
Abstract
Ciphertext-Policy Attribute-Based Encryption (CP-ABE) is a promising access control mechanism for securing cloud data. In ciphertext-policy attribute-based encryption schemes, an access structure is sent along each ciphertext to specify authorized recipients. However, this approach can inadvertently expose users' privacy and compromise the integrity of the messages. To address these challenges, hidden-policy attribute-based encryption schemes have been developed. While numerous methods have been proposed to hide the access policy, limited research has comprehensively evaluated their effectiveness, particularly in terms of security and privacy guarantees. In this thesis, we first review and...
Characterization of nanostructured biodegradable Zn-Mn alloy synthesized by mechanical alloying
, Article Journal of Alloys and Compounds ; Volume 735 , 2018 , Pages 1319-1327 ; 09258388 (ISSN) ; Khaleghpanah, S ; Sheibani, S ; Khakbiz, M ; Zakeri, A ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
In this study, nanostructured biodegradable pure Zn, Zn-4 wt. % Mn and Zn-24 wt % Mn alloys were produced by 20 h mechanical alloying and consequent cold pressing and sintering. Structural evolutions were investigated using the X-ray diffraction technique. Also, the microstructure was characterized by scanning electron microscopy. The effects of alloy composition on density, mechanical properties, corrosion behavior in Hank's solution, cell viability and cell attachment were investigated. Crystallite size of the synthesized alloys after 20 h of milling reached to less than 40 nm and remained less than 80 nm after consolidation and sintering for 1 h. Alloys contain MnZn13 as second phase...
Synthesis and Application of Preformed Viscoelastic Hydrogels in Enhanced Oil Recovery
, M.Sc. Thesis Sharif University of Technology ; Taghikhani, Vahid (Supervisor) ; Baghban Salehi, Mahsa (Supervisor)
Abstract
Preformed particle gels (PPGs) due to its advatantage over commonly used in situ gels has been successfully applied for controlling excess water production in mature oil reservoirs. Field results of using PPGs in oil fields shows that commonly used PPGs are highly sensitive to hard reservoir conditions such as high temperature and salinity and can not effectively block fractures and high permeability layers.Objects of this study are synthesis and evaluating performance of this novel polymer based hydrogel in oil reservoirs with high temperature and salinity. Central composite design ( which is a experiment design approach) was used for synthesizing thirteen gel samples and optimal sample was...
Coating of Sewage Pipes with Appropriate Nanomaterials Aimed at Preventing Biological Growth (Algae+Biofilm)
, M.Sc. Thesis Sharif University of Technology ; Borghei, Mehdi (Supervisor) ; Ghasemi, Shahnaz (Co-Supervisor)
Abstract
Biological layers are one of the main problems related to water transfer with pipe lines which are formed through time in the inner surface of the pipes by the water nutrients. Hence, the inner surfaces in the pipe lines and water refineries should be made in order not to let these biological layers to be made. The reason is that when the biofilm is formed on these surfaces, the traversing water is polluted. Dredging of these pipes is not only necessary in most of the countries in the world and needs huge amounts of water but is also very complex and expensive.In this research, nanomaterials, namely ZnO, T〖iO〗_2،S〖iO〗_2 have been used to cover the surface of concrete and steel pipes (The...
Design and Manufacture of Polymeric Nanocomposite in Order to Control the Production and Migration of Sand in Reservoirs
, Ph.D. Dissertation Sharif University of Technology ; Taghikhani, Vahid (Supervisor) ; Baghban Salehi, Mahsa (Supervisor)
Abstract
Sand production from oil reservoirs leads to various problems, such as well productivity reduction, operating equipment corrosion, and increased production costs. Therefore, controlling sand production in unconsolidated reservoirs is crucial for operating companies. Chemical injection into the formation in order to strengthen and reduce sand production is one of the most important methods of sand control. In this study, a hydrogel nanocomposite was designed and its effectiveness in sand control was investigated. Various tests were carried out to define and assess its efficacy, as follows: Morphological tests demonstrated the creation of a dense, homogeneous, and porous structure. Structural...
Performance Evaluation of Rhamnolipid & Sophorolipid Biosurfactants Capable of Wettability Change and Oil Recovery Increase
, M.Sc. Thesis Sharif University of Technology ; Taghikhani, Vahid (Supervisor) ; Baghban Salehi, Mahsa (Supervisor) ; Mokhtarani, Babak (Co-Supervisor)
Abstract
As fossil fuels are still the world's most important source of energy, as well as the maturity of most of the world's oil reservoirs, there is a need for enhanced oil recovery methods to meet the world's increasing oil demands. MEOR methods are new and promising methods that are still in the research and development stage. One of the MEOR methods is the use of biosurfactants, which increase the oil recovery by two mechanisms: 1) reducing the interfacial tension between water and oil and 2) changing the wettability of the rock. In this study, the performance of two glycolipid biosurfactants, rhamnolipid and sophorolipid, in increasing oil recovery has been investigated. Initially, surface...
Investigation of the Effect of Asphaltene on the Stability of Water-oil Emulsion
, M.Sc. Thesis Sharif University of Technology ; Taghikhani, Vahid (Supervisor) ; Baghban Salehi, Mahsa (Supervisor) ; Masihi, Mohsen (Supervisor)
Abstract
During the production of crude oil from reservoirs, the production of quantities of formation water along with this oil, causes the crude oil does not have the necessary indicators for transportation, refining and ultimately export. The presence of water and salt along with crude oil causes corrosion of refinery and transmission equipment and makes oil unfavorable in terms of economic efficiency (both for domestic use and for export). water and salt produce stable emulsion with oil that can be stable for a long time and can not be easily separated from crude oil. Therefore, separation of water and salt from crude oil is one of the most important issues in the oil industry. Breaking this...
Butanol Production from Bagasse Sugarcane Black Liquor by Native Strain and Clostridium Acetobutylicum Species
,
M.Sc. Thesis
Sharif University of Technology
;
Shayegan, Jalaleddin
(Supervisor)
;
Vossoughi, Manouchehr
(Supervisor)
;
Sedighi, Mahsa
(Co-Supervisor)
Abstract
Considering the limitations of fossil fuels in recent years, as well as increasing demand for biofuels, it is anticipated that future attention to biofuels will increase further. Among biofuels, due to some disadvantages of bioethanol and biodiesel fuel, there is a tendency to use biobutanol, which does not have the disadvantages of the mentioned fuels. The cost of chemical production of butanol also led researchers to use biotechnology production of butanol. According to studies, butanol production can be achieved by fermenting some sugars such as glucose, xylose, and ... by anaerobic microorganism, but the cost of using these sugars has resulted in the use of natural sources of these...
Providing A New Solution to Enhance Oil Recovery (Eor) by Using Properties of Imidazolium Ionic Liquids and Synthesis of Microgels
, M.Sc. Thesis Sharif University of Technology ; Taghikhani, Vahid (Supervisor) ; Baghban Salehi, Mahsa (Supervisor) ; Mokhtarani, Babak (Co-Supervisor)
Abstract
The methods of Enhanced Oil Recovery (EOR) from reservoirs have been taken into consideration recently due to the decline in oil reserves and the rise in energy demand. Studies and investigations indicate the tremendous potential of chemical approaches based on injecting ionic liquids into the porous media with the goal of improving oil recovery. Additionally, hydrogels and polymers, which are two of the process' primary materials, are thought to be good alternatives. In the current study, a hydrogel based on carboxymethyl cellulose was first created and synthesized. Ionic liquids based on imidazolium and triflate anion were then added, and their effectiveness in enhancing the properties...
Evaluation of the Surface Activity of Novel Ionic Liquids and Their Application in the Enhanced Oil Recovery Process
, M.Sc. Thesis Sharif University of Technology ; Taghikhani, Vahid (Supervisor) ; Mokhtarani, Babak (Supervisor) ; Baghban Salehi, Mahsa (Co-Supervisor)
Abstract
The following dissertation discusses Ionic Liquids (ILs) as an alternative to commercial surfactants for use in the Enhanced Oil Recovery process. Ionic Liquids came to researchers’ attention due to their environmental nature and their tolerance for high temperatures and salinity. In this work, firstly, an extensive literature review is carried out, and then, experiments are designed and performed to evaluate ILs’ surface activity and performance in a lab-scale EOR set-up. The Ionic Liquids used in this work consist of three types of methylimidazolium nitrate, [MIM]+[NO3]-, with three different alkyl chain lengths. This combination, and specifically the effect of nitrate anions on EOR and...
Hearing loss prevalence and years lived with disability, 1990-2019: Findings from the Global Burden of Disease Study 2019
, Article The Lancet ; Volume 397, Issue 10278 , 2021 , Pages 996-1009 ; 01406736 (ISSN) ; Kamenov, K ; Briant, P. S ; Orji, A. U ; Steinmetz, J. D ; Abdoli, A ; Abdollahi, M ; Abu-Gharbieh, E ; Afshin, A ; Ahmed, H ; Rashid, T. A ; Akalu, Y ; Alahdab, F ; Alanezi, F. M ; Alanzi, T. M ; Al Hamad, H ; Ali, L ; Alipour, V ; Al-Raddadi, R. M ; Amu, H ; Arabloo, J ; Arab-Zozani, M ; Arulappan, J ; Ashbaugh, C ; Atnafu, D. D ; Babar, Z. U. D ; Baig, A. A ; Banik, P. C ; Bärnighausen, T. W ; Barrow, A ; Bender, R. G ; Bhagavathula, A. S ; Bhardwaj, N ; Bhardwaj, P ; Bibi, S ; Bijani, A ; Burkart, K ; Cederroth, C. R ; Charan, J ; Choudhari, S. G ; Chu, D. T ; Couto, R. A. S ; Dagnew, A. B ; Dagnew, B ; Dahlawi, S. M. A ; Dai, X ; Dandona, L ; Dandona, R ; Desalew, A ; Dhamnetiya, D ; Dhimal, M. L ; Dhimal, M ; Doyle, K. E ; Duncan, B. B ; Ekholuenetale, M ; Filip, I ; Fischer, F ; Franklin, R. C ; Gaidhane, A. M ; Gaidhane, S ; Gallus, S ; Ghamari, F ; Ghashghaee, A ; Ghozali, G ; Gilani, S.A ; Glǎvan, I. R ; Golechha, M ; Goulart, B. N. G ; Gupta, V. B ; Gupta, V. K ; Hamidi, S ; Hammond, B. R ; Hay, S. I ; Hayat, K ; Heidari, G ; Hoffman, H. J ; Hopf, K. P ; Hosseinzadeh, M ; Househ, M ; Hussain, R ; Hwang, B. F ; Iavicoli, I ; Ibitoye, S. E ; Ilesanmi, O. S ; Irvani, S. S. N ; Islam, S. M. S ; Iwagami, M ; Jacob, L ; Jayapal, S. K ; Jha, R. P ; Jonas, J. B ; Kalhor, R ; Al-Salihi, N. K ; Kandel, H ; Kasa, A. S ; Kayode, G. A ; Khalilov, R ; Khan, E. A ; Khatib, M. N ; Kosen, S ; Koyanagi, A ; Kumar, G. A ; Landires, I ; Lasrado, S ; Lim, S. S ; Liu, X ; Lobo, S. W ; Lugo, A ; Makki, A ; Mendoza, W ; Mersha, A. G ; Mihretie, K. M ; Miller, T. R ; Misra, S ; Mohamed, T. A ; Mohammadi, M ; Mohammadian Hafshejani, A ; Mohammed, A ; Mokdad, A. H ; Moni, M. A ; Kandel, S. N ; Nguyen, H. L. T ; Nixon, M. R ; Noubiap, J. J ; Nuñez Samudio, V ; Oancea, B ; Oguoma, V. M ; Olagunju, A. T ; Olusanya, B. O ; Olusanya, J. O ; Orru, H ; Owolabi, M. O ; Padubidri, J. R ; Pakshir, K ; Pardhan, S ; Kan, F. P ; Pasovic, M ; Pawar, S ; Pham, H. Q ; Pinheiro, M ; Pourshams, A ; Rabiee, N ; Rabiee, M ; Radfar, A ; Rahim, F ; Rahimi Movaghar, V ; Ur Rahman, M. H ; Rahman, M ; Rahmani, A. M ; Rana, J ; Rao, C. R ; Rao, S. J ; Rashedi, V ; Rawaf, D. L ; Rawaf, S ; Renzaho, A. M. N ; Rezapour, A ; Ripon, R. K ; Rodrigues, V ; Rustagi, N ; Saeed, U ; Sahebkar, A ; Samy, A. M ; Santric-Milicevic, M. M ; Sathian, B ; Satpathy, M ; Sawhney, M ; Schlee, W ; Schmidt, M. I ; Seylani, A ; Shaikh, M. A ; Shannawaz, M ; Shiferaw, W. S ; Siabani, S ; Singal, A ; Singh, J. A ; Singh, J. K ; Singhal, D ; Skryabin, V. Y ; Skryabina, A. A ; Sotoudeh, H ; Spurlock, E. E ; Taddele, B. W ; Tamiru, A. T ; Tareque, M. I ; Thapar, R ; Tovani-Palone, M. R ; Tran, B.X ; Ullah, S ; Tahbaz, S. V ; Violante, F. S ; Vlassov, V ; Vo, B ; Vongpradith, A ; Vu, G. T ; Wei, J ; Yadollahpour, A ; Jabbari, S. H. Y ; Yeshaw, Y ; Yiǧit, V ; Yirdaw, B. W ; Yonemoto, N ; Yu, C ; Yunusa, I ; Zamani, M ; Zastrozhin, M. S ; Zastrozhina, A ; Zhang, Z. J ; Zhao, J. T ; Murray, C. J. L ; Davis, A. C ; Vos, T ; Chadha, S ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Background: Hearing loss affects access to spoken language, which can affect cognition and development, and can negatively affect social wellbeing. We present updated estimates from the Global Burden of Disease (GBD) study on the prevalence of hearing loss in 2019, as well as the condition's associated disability. Methods: We did systematic reviews of population-representative surveys on hearing loss prevalence from 1990 to 2019. We fitted nested meta-regression models for severity-specific prevalence, accounting for hearing aid coverage, cause, and the presence of tinnitus. We also forecasted the prevalence of hearing loss until 2050. Findings: An estimated 1·57 billion (95% uncertainty...