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hosseinzadeh-fakhr--mahan
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Investigation of Water Electrical Parameters as a Function of Measurement Frequency and Concentration Using Cylindrical Capacitive Sensors
, M.Sc. Thesis Sharif University of Technology ; Golnabi, Hossein (Supervisor) ; Gobal, Fereydoon (Co-Advisor)
Abstract
The electrical conductivity of the solution has been one of the important physical quantities in many application. In this respect many probes and devices such as conductive sensors have been devised. In this study electrical properties of different water samples at frequency step range of 100-100000 Hz are measured by using the long cylindrical capacitive sensor and a measuring module (LCR-703). Operation of the capacitance measurement module for such probes is based on the auto balancing bridge method. Comparison of the measured capacitances and measured resistances for different water samples shows a decrease by increasing the measurement frequency. In another study the dielectric...
Applying TPM Concept in an Alloy Steel Plant
, M.Sc. Thesis Sharif University of Technology ; Houshmand, Mahmoud (Supervisor)
Abstract
The alloy steel plant was exploited in1999; and the maintenance department starts its function and its activities according to the written PM software by Austria’s BOHLER Company. The PM program was written for the entire factory. Having worked with the PM for eight years, now it is possible to evaluate its performance. There are two main problems in the maintenance system; firstly, the existing PM System is incomplete, some important feature of the PM program is incomplete. Secondly there are lacks of a good auditing system to evaluate the PM orders. To evaluate the weakness of the current PM system and to study application of TPM, a section of the factory was...
On Proofs and Some Consequences of Serre’s Conjecture on Projective Modules
,
M.Sc. Thesis
Sharif University of Technology
;
Jafari, Amir
(Supervisor)
Abstract
Jean-Pierre Serre in 1955, in his famous article “Faisceaux Algébriques Cohérents” asked if there is any finitely generated projective module on polynomial rings which is not free. Or equivalently: is there any non-trivial algebraic vector bundle over an affine space? The negative answer to this question is known as Serre’s conjecture and it was an open problem in algebra and affine algebraic geometry until 1976, when it was proved independently by Quillen and Suslin. The challenge of solving this question and its consequences led to a vast amount of research in commutative algebra, homological algebra and algebraic K-theory and inspired generalizations and similar questions. In this thesis...
Aerodynamic Design of 100 kW Transonic Ducted Fan
, M.Sc. Thesis Sharif University of Technology ; Ghorbanian, Kaveh (Supervisor)
Abstract
The purpose of this research is the aerodynamic design of a 100 kW transonic ducted fan. Today, the aviation industry is moving towards the design of electric driven aircraft propulsion. Transonic ducted fans are one of the viable options that have been used in medium and heavy aircrafts due to their high specific power. In this research, the meanline model has been used for the initial design. By applying the design constraints, design limitations, design and functional parameters, the initial design point is found and then a sensitivity analysis is performed with respect to the effective design parameters to obtain the optimal design point. For the initial design of the transonic ducted...
The addition of data aggregation to SPEED routing algorithm while keeping the functionality of available techniques
, Article 2nd International Conference on Future Networks, ICFN 2010, 22 January 2010 through 24 January 2010 ; January , 2010 , Pages 349-353 ; 9780769539409 (ISBN) ; Yousefi Fakhr, F ; Movaghar, A ; Sharif University of Technology
2010
Abstract
Data aggregation is a technique that is used to decrease extra and repetitive data in cluster based routing protocols. As we know SPEED routing algorithm is based on service quality and dose not perform data aggregation. In this article, we try to add an data aggregation technique to the available techniques without interfering with the functions of previous ones. The idea involves virtual configuration of sensors and specification of an individual ID to the created data by the sensors in each region, then data aggregation in relay node is done by this ID, resulting in less energy consumption, lower traffic and repeated data, an increase in network lifetime and better quality of service
The addition of data aggregation to non cluster based SPEED routing algorithm while keeping the functionality of available techniques inorder to increase QoS
, Article ; Volume 2 , April , 2010 , Pages V2696-V2700 ; ICCET 2010 - 2010 International Conference on Computer Engineering and Technology, Proceedings, 16 April 2010 through 18 April 2010 ; 9781424463503 (ISBN) ; Roustaei, R ; Movaghar, A ; Sharif University of Technology
2010
Abstract
Data aggregation is a technique that is used to decrease extra and repetitive data in cluster based routing protocols. As we know SPEED routing algorithm is based on service quality and dose not perform data aggregation. In this article, we try to add an data aggregation technique to the available techniques without interfering with the functions of previous ones. The idea involves virtual configuration of sensors and specification of an individual ID to the created data by the sensors in each region, then data aggregation in relay node is done by this ID, resulting in less energy consumption, lower traffic and repeated data, an increase in network lifetime and better quality of service
Modified carrageenan. 5. Preparation, swelling behavior, salt- and pH-sensitivity of partially hydrolyzed crosslinked carrageenan-graft-polymethacrylamide superabsorbent hydrogel [electronic resource]
, Article Polymers for Advanced Technologies ; Volume 15, Issue 11, pages 645–653, November 2004 ; Sadeghi, M ; Hosseinzadeh, H
Abstract
The polysaccharide, kappa-carrageenan (κC) was chemically modified to achieve a novel superabsorbent hydrogel via graft copolymerization of methacrylamide (MAM) onto the substrate followed by alkaline hydrolysis. Ammonium persulfate (APS) and N,N′-methylene bisacrylamide (MBA) were used as a free-radical initiator and a crosslinker, respectively. The saponification reaction was carried out using sodium hydroxide aqueous solution. Either κC-g-PMAM or hydrolyzed κC-g-PMAM (PMAM: polymethacrylamide) was characterized by FT-IR spectroscopy. The effect of grafting variables (i.e. concentration of MBA, MAM, and APS) and alkaline hydrolysis conditions (i.e. NaOH concentration, hydrolysis time and...
Modified carrageenan. 4. Synthesis and swelling behavior of crosslinked kappa C-g-AMPS superabsorbent hydrogel with antisalt and pH-responsiveness properties [electronic resource]
, Article Journal of Applied Polymer Science ; Vol.98, No.1, 255-263, 2005 ; Hosseinzadeh, H ; Mazidi, R
Abstract
To synthesize a novel biopolymer-based superabsorbent hydrogel, 2-acrylamido-2-methylpropanesulfonic acid (AMPS) was grafted onto kappa-carrageenan (KC) backbones. The graft copolymerization reaction was carried out in a homogeneous medium and in the presence of ammonium persulfate (APS) as an initiator, N,N,N',N'-tetramethyl ethylenediamine (TMEDA) as an accelerator, and N,N'-methylene bisacrylamide (MBA) as a crosslinker. A proposed mechanism for KC-g-AMPS formation was suggested and the hydrogel structure was confirmed using FTIR spectroscopy. The affecting variables on swelling capacity, i.e., the initiator, the crosslinker, and the monomer concentration, as well as reaction temperature,...
Partially hydrolyzed crosslinked alginate-graft-polymethacrylamide as a novel biopolymer-based superabsorbent hydrogel having pH-responsive Properties [electronic resource]
, Article Macromolecular Research ; January 2005, Volume 13, Issue 1, pp 45-53 ; Aminfazl, M. S ; Hosseinzadeh, H
Abstract
In this study, a series of highly swelling hydrogels based on sodium alginate (NaAlg) and polymethacrylamide (PMAM) was prepared through free radical polymerization. The graft copolymerization reaction was performed in a homogeneous medium and in the presence of ammonium persulfate (APS) as an initiator andN,N′-methylenebisacrylamide (MBA) as a crosslinker. The crosslinked graft copolymer, alginate-graft-polymethacrylamide (Alg-g-PMAM), was then partially hydrolyzed by NaOH solution to yield a hydrogel, hydrolyzed alginate-graft-polymethacrylamide (H-Alg-g-PMAM). During alkaline hydrolysis, the carboxamide groups of Alg-g-PMAM were converted into hydrophilic carboxylate anions. Either the...
Wideband 5 W Ka-Band GaAs Power Amplifier
, Article IEEE Microwave and Wireless Components Letters ; Volume 26, Issue 8 , 2016 , Pages 622-624 ; 15311309 (ISSN) ; Medi, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
This letter presents a Ka-Band 0.1-μm GaAs pHEMT Power Amplifier with broad bandwidth. The isolating backvia wall (IBVW) has been proposed to improve the stability and performance. Over the frequency band of 31-40 GHz, implemented PA delivers 5 W saturated output power, 28% maximum power added efficiency (PAE) and 20 dB maximum small-signal gain. The chip size of the PA is 11.9 mm2. To the best of authors knowledge, the presented PA demonstrates widest bandwidth in Ka-band GaAs PAs while maintaining compact size
Design of Robust Controller for Depth of Anesthesia
, M.Sc. Thesis Sharif University of Technology ; Sadati, Nasser (Supervisor)
Abstract
Automatic control of depth of anesthesia is an important problem in biomedical engineering. The main challenging problem in anesthesia automation is inter-patients differences which is referred to as uncertainty and is crucial in robust controller design. One of the most appropriate tools in designing robust controllers is H_∞ concept. Furthermore, H_2 concept is used to reject the measurement noise which is unavoidable in practical cases. In this project we use mixed H_2/H_∞ concept to design robust controller for depth of anesthesia. Multi-model controller is another approach to design robust controller for depth of anesthesia, which reject measurement noise and also cover the...
Design and Implementation of a Ka-band Power Amplifier in GaAs pHEMT
, M.Sc. Thesis Sharif University of Technology ; Medi, Ali (Supervisor)
Abstract
Power amplifiers are used as the last block of transmitters. This block can be categorized as the one of most important part in communication systems. However, in transmitter systems which require high power to create stable link with the receivers, fabrication process like CMOS are unable to provide such level of power. Thus, designers employ another group of integrated circuits which names MMIC that offers this capability to designers. In this thesis, design procedure of an amplifier in Ka frequency bands is studied. The power amplifier is fabricated in 0.1um GaAs pHEMT.The isolating backvia wall (IBVW) technique hasbeen proposed to improve gain and stability. Some other designtechniques...
The Analytical Study of the Nonlinear Behavior of Conventional and Retrofitted Khorjini Connections
, M.Sc. Thesis Sharif University of Technology ; Moghaddam, Hassan (Supervisor)
Abstract
The purpose of this research is to study the behavior of conventional and retrofitted Khorjini connections. Thus the software ABAQUS 6.11 was used to fabricate the FEM models of the connections with experimental prototypes. In analytical studies, 21 specimens with different size of the connection components were analyzed. True stress–strain curves for steel and weld materials were used and damage initiation and revolution were considered in the weld material. Also cracking of the welds were considered by a micromechanical method. Behavioral characteristics of the conventional connections are specified and appropriate relations are suggested, using Stability equations of the connection...
On the Zagreb indices of nanostar dendrimers
, Article Optoelectronics and Advanced Materials, Rapid Communications ; Volume 4, Issue 3 , 2010 , Pages 378-380 ; 18426573 (ISSN) ; Ghorbani, M ; Sharif University of Technology
2010
Abstract
Let G be a graph. The first and second Zagreb index of G is defined as M1(G)= Σ degG(V)2 and M2(G)= Σ degG(u)degG(V) respectively. In this paper we compute Zagreb indices of chain graphs
Study of Effective Parameters on Roasting of Zinc Sulphide in a Fluidized Bed Reactor
, M.Sc. Thesis Sharif University of Technology ; Halali, Mohammad (Supervisor)
Abstract
In this study, four parameters were investigated including temperature, inlet flow rate, gas composition (oxygen) and particle size on the roasting of Bama company zinc sulfide concentrate in Fluidized bed reactor. Initially, primary sample was heated in electric furnace at 125℃ for 24 hours until the moisture content dried. Then roasting operation was done at 700 and 900℃. The operation was carried out on three range of particle size including 300-500, 500-700 and 700-1000 microns and flow rate was greater than the minimum flow rate of Fluencing. To investigate the effect of flow rate and gas composition input, 500-700 micron particle size range was selected. The effect of 155, 172 and 188...
A Mathematical Model to Apportion the Cost of Kidney Purchasing in Domino-paired Donation
, M.Sc. Thesis Sharif University of Technology ; Najafi, Mehdi (Supervisor)
Abstract
The human body normally has two functioning kidneys, while only one of them is sufficient to have a healthy life. However, for those patients having no functioning kidney, transplantation is the most effective treatment. Although deceased donors have been usually used as the main source for kidney donation in many countries, there are several cases focusing on living kidney donation to compensate for the shortage in supply and to reduce the patient waiting time for treatment. Because of this potential, many studies have been conducted to optimize the non-clinical issues of kidney transplant waiting lists. Notwithstanding employing the financial incentives for living kidney donation is...
Fermions in Lattice Gauge Theory, Ising Model and Non-Equilibrium Systems
, M.Sc. Thesis Sharif University of Technology ; Sadooghi, Néda (Supervisor)
Abstract
Non-equilibrium systems refer to systems in which, unlike equilibrium systems, the initial condition plays an important role. Conventional methods in quantum field theory cannot be used to study these systems because they do not necessarily have a convergent perturbative expansion.In this thesis, we first briefly introduce the Ising model and fermions in the lattice gauge theory. We then introduce the two-particle irreducible (2PI) method as a tool to investigate nonequilibrium systems. Finally, using this method, we reformulate the Ising model for a system out of equilibrium
Quantum integrability of 1D ionic hubbard model
, Article Annalen der Physik ; Volume 532, Issue 3 , 2020 ; Jafari, S. A ; Sharif University of Technology
Wiley-VCH Verlag
2020
Abstract
The quantum integrability of the 1D ionic Hubbard model (IHM) is established using two independent numerical methods, namely i) energy level spacing statistics and ii) occupation profile of one-particle density matrix (OPDM) eigen-values. Both methods suggest that the 1D IHM is integrable. The calculations of energy level statistics reproduce the known results for the standard Hubbard model. Upon turning on the the ionic term, the energy level spacing distribution of this model continues to obey the Poissonian distribution. Occupation patterns as extracted from OPDM indicate that quasi-particles are sharpened upon increasing the ionic potential. This is evidenced by a larger jump in the...
Generalization of Lieb–Wu wave function inspired by one-dimensional ionic Hubbard model
, Article Annals of Physics ; Volume 414 , 2020 ; Jafari, S. A ; Sharif University of Technology
Academic Press Inc
2020
Abstract
With the ionic Hubbard model (IHM) in mind, we construct a non-trivial generalization of the Bethe ansatz (BA) wave function which naturally generalizes the Lieb–Wu wave function with an ionic parameter Δ, and reduces to Lieb–Wu solution in the limit Δ→0. The resulting two-particle scattering matrix satisfies the Yang–Baxter equation. To the extent that the unit cells with more than two electrons (Choy–Haldane issue) are avoided on average, our wave function represents an effective solution for the one-dimensional IHM. The Choy–Haldane issue limits the validity of our solution to low-filling and large U≳4. This regime is attainable in cold atom realizations of the IHM. For this regime, we...
Numerical Investigation of Concrete Beams Reinforced with Perforated Plates
, M.Sc. Thesis Sharif University of Technology ; Khaloo, Alireza (Supervisor)
Abstract
In this study, the flexural behavior of simple concrete beams with rectangular section (depth 20cm and width 18 cm) reinforced with perforated steel plates is evaluated. Perforated steel plates are used as an alternative for steel bars in the tension region. Because of special geometry, these plates are more integrated with surrounding concrete as compared with steel rebars. The holes in the plates caused local confinement on the surrounding concrete. Concrete beams are modeled with different number of perforated steel plates (one or two or four layer) in Abaqus software. Also beams with different patch lengths are modeled to evaluate patch length of perforated steel plates. Results of...