Design and Fabrication of a Balance Training Apparatus

, M.Sc. Thesis Sharif University of Technology Behjat, Amir (Author) ; Behzadipour, Saeed (Supervisor) ; Farahmand, Farzam (Co-Advisor)

Abstract

One of the main reasons of being unable in doing routine jobs is the disability to attain and keep balance. This ability can be restored using rehabilitation techniques. A physiotherapist can be very helpful. This approach, however, apart from being very time consuming and expensive, needs quite a few physiotherapists. The physiotherapist will be prone to physical damages as well. This leads to improving therapy methods which do not require a physiotherapist. Using the rehabilitation balance devices can help solve the problem to some extents. If good device with reliable value system be developed, this device can be used without physiotherapist.
This project has been carried out to...

Total completion time minimisation of no-wait flowshop group scheduling problem with sequence dependent setup times

, Article European Journal of Industrial Engineering ; Volume 11, Issue 1 , 2017 , Pages 22-48 ; 17515254 (ISSN) Behjat, S ; Salmasi, N ; Sharif University of Technology

Inderscience Enterprises Ltd 2017

Abstract

In this research, the no-wait flowshop sequence dependent group scheduling problem with minimisation of total completion time, noted as Fm|nwt, fmls, Splk|∑Cj is approached. A mixed integer linear mathematical model is proposed for the research problem. Due to the NP-hard nature of the proposed problem, several metaheuristic algorithms based on particle swarm optimisation and variable neighbourhood search with different neighbourhood search structures are proposed to heuristically solve the problem. Also, an efficient heuristic algorithm is proposed to generate the initial feasible solutions for the proposed algorithms. The performances of the proposed algorithms are compared with each other...

Group Scheduling on Flow Shop with Sequence Dependent Setup Times and no Wait Assumption

, M.Sc. Thesis Sharif University of Technology Behjat, Saeed (Author) ; Salmasi, Naser (Supervisor)

Abstract

The present thesis is focused upon the flow shop sequence dependent group scheduling problem (FSDGS) with no wait assumption. Generally, production sequencing and scheduling is considered as one of the most important factors in productivity and cost saving of organizations. Therefore, determining an appropriate sequencing of groups and jobs according to the logical constraints is expected to improve the performance and productivity of the production system.
In this thesis, due to the importance and multiple applications of this problem, we will consider the FSDGS problem and propose new heuristic and metaheuristic algorithms to tackle this problem. Since the good performance of...

Praparation of Nanometric Platinum Coatings on Carbon Substrate (Pt/C) for Catalytic Plates of Fuel Cells

, M.Sc. Thesis Sharif University of Technology Behjat, Saeed (Author) ; Ghorbani , Mohammad (Supervisor) ; Afshar, Abdollah (Supervisor)

Abstract

With increasing pollution and decrease in global reservoirs of fossil fuels, a lot of interest has been attracted to fuel cells as efficient and clean energy sources. Polymeric (membrane) fuel cells are special type of fuel cells, which can be built in small dimensions and power. These cells use hydrogen (and oxygen or air) and produce water. In these cells, platinum is used as electrode (and electrocatalyst) both in anode and cathode, due to its low overvoltage for both hydrogen and oxygen. To increase the efficiency of these coatings, it is best to produce platinum particles with maximum area and it automatically leads to nanometric particles. In this thesis, platinum particles are...

Experimental Investigation and CFD Simulation of the Flow Pattern of the FCC's Fluidized Bed Regenerator

, M.Sc. Thesis Sharif University of Technology Azarnivand, Abbas (Author) ; Dehkordi, Asghar Molaei (Supervisor) ; Seifkordi, Aliakbar (Supervisor) ; Behjat, Yaghoub (Supervisor)

Abstract

Hydrodynamic behavior of gas-solid fluidization in large-diameter beds like FCC regenerator exhibits complex aspects. To investigate the gas-solid flow pattern of UOP's combustor-style FCC regenerator, a lab-scale regenerator was designed by a downscale factor of 0.045. The regenerator's operation and fluidization of FCC particles through it was examined and pressure axial distributions were measured and analyzed at different superficial air velocities. 3D CFD simulation of the regenerator was performed with Eulerian-Eulerian approach to investigate the effects of operating conditions, including superficial air velocity, catalyst mass flux, presence of recirculated catalyst, and the...

Performance of three-level spectrally encoded spreadtime CDMA in the presence of multiple interferences [electronic resource]

, Article IET Communications ; July 2011, Volume 5, Issue 10, P. 1328-1335 Mashhadi, S. (Saeed) ; Mashhadi, Saeed ; Salehi, J. A ; Sharif University of Technology

Abstract

In this study the authors present an in-depth study, analysis and discussion on maximum likelihood (ML)-based receiver for a typical spectrally encoded spread-time CDMA in the presence of multiple narrowband interference (NBI) signals in an additive white Gaussian noise channel. Furthermore, the authors demonstrate that by combining useful properties of ML-based receiver and three-level codes, that is, codes with values of -1, 0, +1, the authors can introduce a new strategy in which superior performance with respect to previous receiver structure based on two-level codes, that is, codes with values of -1, +1, can be attained. With the help of an example, the authors drive, first, the...

Investigation of Multiphase Flow in Oil Wells (with Focus on Two Phase Flow), Flow Pattern Recognition and Modeling

, M.Sc. Thesis Sharif University of Technology Shams, Reza (Author) ; Shad, Saeed (Supervisor) ; Jamshidi, Saeed (Supervisor)

Abstract

The concurrent flow of oil and water is a common occurrence in the field of multiphase flow in different fields including petroleum industry. In oil and gas, production engineers often face a situation in which more than one phase is flowing through the producers. In such conditions an accurate assessment of pressure loss inside the well plays a vital role in efficient and effective production planning. Changes in well orientation, wellbore diameter, reservoir and fluid properties as well as fluid flow rates are among parameters in which will affect the flow patterns that can occur inside a well during its life time. These flow patterns are created as a result of a competition between...

Casing Design Optimization Considering Drilling and Production Conditions

, M.Sc. Thesis Sharif University of Technology Sadeghi, Mahdi (Author) ; Jamshidi, Saeed (Supervisor) ; Shad, Saeed (Supervisor)

Abstract

Casing design is one of the most expensive parts in the drilling of oil wells, and any cost reduction with the basic design of these casing strings will significantly reduce the total cost of the operation. In recent years, occurring scenarios-based casing design has become popular; Because in many cases, it eliminates non-occurring scenarios such as gas kick and saves on drilling costs. In this study, we have tried to investigate all scenarios that may occur during the lifetime of the well, whether drilling or production, and for each well, based on its own field information, possible scenarios for each casing part are selected separately and the applying loads are calculated. For this...

PRI (Palm Rotation Indicator): a metric for postural stability in dynamic nonprehensile manipulation [electronic resource]

, Article Journal of MECHANIKA ; 2012, Vol. 18, No. 4, pp. 461-466 Beigzadeh, B. (Borhan) ; Meghdar, Ali ; Sohrabpour, Saeed ; Sharif University of Technology

Abstract

In this study, we discuss the postural stability of a nonprehensile manipulation problem, which deals with multibody objects. As a metric for postural stability, we define PRI. Then, the system is posturally stable, if PRI is inside the convex hull of the object-manipulator contact surface. We then discuss that dynamic biped locomotion is a special case of dynamic nonprehensile manipulation in all aspects; we prove that ZMP (zero-moment point) and FRI (zoot rotation indicator) are special cases of PRI (palm rotation indicator). Simulations and experiments corresponding to simple examples support the results

On the Domination Polynomial of Graphs

, M.Sc. Thesis Sharif University of Technology Ebrahimi, Zeinab (Author) ; Akbari, Saeed (Supervisor)

Some Applications of Combinatorial Nullstellensatz in Graph Theory and Combinatorics

, M.Sc. Thesis Sharif University of Technology Fakhari, Amin (Author) ; Akbari, Saeed (Supervisor)

Electrochemical Determination of Piroxicam at thin Carbon
Nanoparticle Composite And Investigation of the Electrochemical Behavior and Synthesis of Catechols in the Presence of Mercapto Methyl Tetrazol as a Nucleophile

, M.Sc. Thesis Sharif University of Technology Jokar, Effat (Author) ; Shahrokhian, Saeed (Supervisor)

Abstract

The electrochemical oxidation behavior of the anti-inflammatory drug piroxicam was investigated. A carbon nanoparticle (CNP)-chitosan (CS) film-coated graphite electrode (PGE) was fabricated and the electrochemical behaviors of piroxicam on its surface was investigated by the means of cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). In comparison to the bare PGE, at the surface of the CNP-CS film modified electrode, the oxidation peak current of piroxicam increased significantly and the peak potential shifted negatively. Consequently, a simple and sensitive electroanalytical method was developed for the determination of piroxicam. The...

Chemically Modified Electrodes Based on Conducting Polymers and Carbon Nanotubes: Application to Voltammetric Determination of Some Biological and Pharmaceutical Compounds

, M.Sc. Thesis Sharif University of Technology Asadian, Elham (Author) ; Shahrokhian, Saeed (Supervisor)

Abstract

There are high attractions in the development of conducting polymer (CP) coatings to improve the electrochemical properties and biocompatibility of electrodes in the area of biosensors. In the first part of this thesis, a new type of modified electrodes, constructing multi-walled carbon nanotubes (MWCNTs) and polypyrrole is prepared in a layer-by-layer process. In this procedure, the glassy carbon electrode is casted first by a drop suspension of MWCNTs, leading to formation a thin film on its surface. In the second step, electrochemical polymerization of pyrrole in the presence of tiron (used as doping anion) is performed on the surface of the MWCNTs pre-coated electrode. The modification...

Probing the Electrochemical Properties of Gold Electrode Modified with Edge-Functionalized Graphene and its Application

, M.Sc. Thesis Sharif University of Technology Aghajani, Talin (Author) ; Shahrokhian, Saeed (Supervisor)

Abstract

In the present work, edge-functionalaized graphene was used as electrode material and its electrochemical properties were systematically characterized by electrochemical impedance spectroscopy and cyclic voltammetry. Two methods were applied to modify the gold electrode surface. First method was the self assembling process of graphene nanosheets on gold electrode surface. Second method was simply casting specific amounts of graphene suspension on the gold electrode surface. Nyquist plots show decrease of the charge transfer resistance on the electrode surface at both cases. In cyclic voltammetry studies, first electrode shows no significant changes while the second electrode exhibits...

Probabilistic Methods in Graph Coloring

, M.Sc. Thesis Sharif University of Technology Ahadi, Arash (Author) ; Akbari, Saeed (Supervisor)

Abstract

Graph Theory and Combinatorial Analysis like the other branches of science use the probability for solving their problems. At the first , we will introduce the most common tools from probability used in Discrete Mathematics, such as “The Lovasz Local Lemma”. Most of them are based on Linearity of Expectation, Concentration Theorems and some other innovative methods such as Deletation Method. We will present different examples for these techniques. Also we will introduce “Random Graphs” and their importance. Specially we will explain how to use “Threshold Functions” to obtain different properties about the majority of graphs. Rainbow Connection, is a natural and interesting quantifiable way...

Electrochemical Determination of Tyrosine and Tryptophan at the Surface of Pyrolytic Graphite Electrode Modified with Multi-Walled Carbon Nanotubes, New Coccine and Nitrazine

, M.Sc. Thesis Sharif University of Technology Ebrahimi, Shiva (Author) ; Shahrokhian, Saeed (Supervisor)

Abstract

At the first part of this thesis, a pyrolitic graphite electrode (PGE) modified with new coccine/multi-walled carbon nanotubes film (NC/MWCNT) was applied as a sensitive electrochemical sensor for determination and study of electrochemical behavior of tyrosine (Tyr) in aqueous solutions. The results showed that NC/MWCNT caused a remarkable increase in the peak current so the NC/MWCNT/PGE electrode surface was far more sensitive to the concentration of Tyr than the PGE surface. The determination of Tyr was investigated by linear sweep voltammetry (LSV). Experimental parameters, such as scan rate, pH and amount of the modifier used on the PGE surface were optimized by monitoring the LSV...

The Regular Graph Retated to Rings

, M.Sc. Thesis Sharif University of Technology Jamaali, Mohsen (Author) ; Akbari, Saeed (Supervisor)

Abstract

There are many papers in which some graphs are assigned to algebraic structures such as rings groupsThe concept of regular graph related to a ring was rst investigated by DF Anderson and A Badawi in Assume that R is a commutative ring and Z??R denotes the set of zerodivisors of R and Reg??R R n Z??R The regular graph of R which is denoted by Reg????R is a graph whose vertex set is Reg??R and two vertices x and y are adjacent if and only if x y ?? Z??R This can be generalized to a non commutative ring For the vertex set we consider the set of left ??right zerodivisors and join two elements if their sum is a left ??right zerodivisor Let R be the ring of n n matrices over a eld F with...

Zero-sum Flows in Graphs

, M.Sc. Thesis Sharif University of Technology Nategh, Emisa (Author) ; Akbari, Saeed (Supervisor)

Abstract

For an undirected graph G, a zero-sum flow is an assignment of non-zero real numbers on the edges of G such that the total sum of all edges incident with any vertex of G is zero. A zero-sum k-flow for a graph G is a zero-sum flow with labels from the set {±1, . . . , ±(k ? 1)}. In this thesis for a graph G, a necessary and sufficient condition forthe existence of zero-sum flow is given. It has been conjectured that if a graph G has azero-sumflow, then it has a zero-sum 6-flow. Also, it has been proved that this conjectureand Bouchet’s Conjecture for bidirected graphs are equivalent. It is shown that the con-jecture is true for 2-edge connected bipartite graphs, and every r-regular graph...

Application of Pore Network Modeling in Study of Rock Typing Algorithms

, M.Sc. Thesis Sharif University of Technology Sistan, Morteza (Author) ; Jamshidi, Saeed (Supervisor)

Abstract

One of the most important issues in modeling and simulation of reservoirs is determination of different rock types or Rock Typing. In this study, after a brief review of some conventional methods for rock typing, their capabilities have been investigated. In this way, for the first time, pore network modeling is used as a tool for validating the rock typing methods. By using flow simulation in porous medium with pore network modeling approach, similar rock types data have been generated and these artificially data have been used for validating of rock typing methods. To form more realistic pore networks, both regular and irregular pore network have been modeled and analyzed. Pore size...

On the Roman Domination Number of Graphs

, Ph.D. Dissertation Sharif University of Technology Qajar, Sahar (Author) ; Akbari, Saeed (Supervisor)

Abstract

Let G be a graph. A labeling f : V (G) ! f0; 1; 2g is called a Roman dominating function, if every vertex u with f(u) = 0 has at least a neighbor v with f(v) = 2. Define the weight of a Roman dominating function f to be w(f) =Σv2V (G) f(v). The Roman domination number of G is R(G) = minfw(f) : f is a Roman dominating functiong. Some other parameters are defined based on Roman domination number. A Roman bondage number bR(G) of G is the minimum cardinality of all sets E E(G) for which R(G E) > R(G). The edge Roman domination number of G, LR(G), is defined as R(L(G)), where L(G) is the line graph of G. In this thesis, after determining the exact value of the Roman bondage number for some...