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takalloozadeh--meisam
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Shape optimization of concrete arch dams considering abutment stability
, Article Scientia Iranica ; Vol. 21, issue. 4 , 2014 , p. 1297-1308 ; 10263098 ; Ghaemian, M ; Sharif University of Technology
2014
Abstract
A novel and robust approach is proposed to find the optimum shape of concrete arch dams located on any unsymmetrical shape of a valley. The approach is capable of finding the optimum shape for any given valley type in suitable time, based on abutment stability analysis, against thrust forces from an arch dam. The behavior and stability of a concrete arch dam is strongly dependent on the bedrock on which the dam rests. The stability of the abutment is considered a constraint in the proposed approach. In addition, a new objective function is introduced to decrease the final volume of the arch dam. Furthermore, a computer program was developed, which takes the effect of the dam foundation...
Displacement and stress constrained topology optimization
, Article Proceedings of the ASME Design Engineering Technical Conference, Portland, OR ; Volume 2 A , August , 2013 ; 9780791855850 (ISBN) ; Suresh, K ; Sharif University of Technology
American Society of Mechanical Engineers
2013
Abstract
The objective of this paper is to demonstrate a topology optimization method subject to displacement and stress constraints. The method does not rely on pseudo-densities; instead it exploits the concept of topological level-set where 'partial' elements are avoided. Consequently: (1) the stresses are well-defined at all points within the evolving topology, and (2) the finite-element analysis is robust and efficient. Further, in the proposed method, a series of topologies of decreasing volume fractions are generated in a single optimization run. The method is illustrated through numerical experiments in 2D
Shape Optimization of Concrete Arch Dams
, Ph.D. Dissertation Sharif University of Technology ; Ghaemian, Mohsen (Supervisor)
Abstract
Finding an initial point to start classical optimization methods is privileged to finding an algorithm. It is due to high dependency of final result to selection of initial point, which is independent of type of the algorithm. In engineering optimization where space of problem has several local extremums, this fact has higher effects. In the present study, to overcome this problem in finding optimum shape of concrete arch dams, a two-stage approach is proposed. In the first stage (discrete stage), using the developed stress-constrained topology optimization, an initial optimum shape is obtained. Afterward in the next stage (continuous stage), the optimum shape obtained from previous stage is...
Heidegger on Science and Tool (Emphasized on "Being and Time")
,
M.Sc. Thesis
Sharif University of Technology
;
Sefidkhosh, Meisam
(Supervisor)
;
Taghavi, Mostafa
(Co-Advisor)
Abstract
This thesis is going to investigate the ontological foundation of Science and Tool. To this aim, it refers to Heidegger’s works especially the Being and time. Heidegger gets involve in analyzing Science in the Being and Time. He emphasizes on importance of establishment of a fundamental knowledge which should ontologically recognize basic concepts and methods of Sciences, to cause a real progress in sciences. Heidegger also asserts that the Mathematical interpretation of the world is not a fundamental, and it must be replaced with phenomenological interpretation, which clarifies the ontological foundation of the theoretical view, and regards to all aspects of world’s existence. In this...
Kierkegaardian Faith: On The Subject of Faith and Her Hope
, M.Sc. Thesis Sharif University of Technology ; Sefidkhoh, Meisam (Supervisor) ; Azadegan, Ebrahim (Supervisor)
Abstract
In this treatise, it will be shown that the subject of faith is the subject who loves God and in showing her love to God, she sacrifices her dearest things in the world. By doing that, she would free herself from everything that mind herself. She doesn’t do this action to be given a better reward by God. Her motivation for performing this action is nothing but love. Meanwhile, the subject of faith hopes God to respond to her love and engage in an I-Thou relationship with her. Now, her hope would be justified when God plays an active role in the world and admires her action, i.e., when eros can be attributed to God
Study of Dispersed Phase Holdup and Slip Velocity in a Pulsed Disc and Doughnut Extraction Column
, M.Sc. Thesis Sharif University of Technology ; Outukesh, Mohammad (Supervisor) ; Torab Mostaedi, Meisam (Supervisor)
Abstract
Dispersed phase holdup has been measured in a 75 mm diameter pulsed disc and doughnut extraction column for three different liquid-liquid systems. The effects of operational variables such as pulsation intensity and dispersed and continuous phases flow rates on holdup have been investigated and found to be significant. The existence of three different operational regimes, namely mixer-settler, dispersion, and emulsion regimes, was observed when the energy input was changed. The results indicated that the characteristic velocity approach is applicable to this type of extraction column for analysis holdup in transition and emulsion regions. Empirical correlations are derived for prediction of...
Investigation of Equilibrium and Kinetics of Uranium Solvent Extaction by Cyanex 301 Using a Single Drop Column
, M.Sc. Thesis Sharif University of Technology ; Samadfam, Mohammad (Supervisor) ; Torab-Mostaedi, Meisam (Supervisor)
Abstract
Uranium separation from other metals in ore and nuclear waste is one of the most important stagesin nuclear fuel cycling. Solvent extraction is the common method for uranium extraction that reagent plays important rule in this technique. In this investigation, uranium solvent extraction is carried out by Cyanex 301 as reagent from nitric acid. At beginning, equilibrium batch extraction was carried and the effect of parameters such as pH, reagent concentration, temperature, shaking time of two phases, volumetric ratio of two phases, diluent and nitric acid concentration on extraction was investigated and optimum value of parameters was calculated. Uranium concentration effect was also...
Synthesis of CaO Impregnated on Carbon Nano Tube for Biodiesel Production
, M.Sc. Thesis Sharif University of Technology ; Khorashe, Farhad (Supervisor) ; Tabatabaei, Meisam (Supervisor) ; Rashidi, Alimorad (Supervisor)
Abstract
In the current work, jatropha oil was studied in the hetrogenious solid catalytic transesterfication reaction. For this perpous, KOH/CNT catalyst which was prepared by dry impregnation method was used. SEM, XRD and TGA were applied for the catalyst characterization. The results showed that for the KOH/CNT catalyst, by increasing the loading of KOH, the activity of the catalyst increased and the most active catalyst was prepared by 20% loading of KOH. The optimum conditions for transesterfication reaction in the percense of this catalyst were: 4.7% catalyst weigth and the 24.5 molar ratio of methanol to oil and also the reaction time of 2 houres which the rate of reaction at this time is...