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khorrami-jahromi--arash
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Theoretical study of diffusional release of a dispersed solute from cylindrical polymeric matrix: A novel configuration for providing zero-order release profile
, Article Applied Mathematical Modelling ; Volume 73 , 2019 , Pages 136-145 ; 0307904X (ISSN) ; Shieh, H ; Saadatmand, M ; Sharif University of Technology
Elsevier Inc
2019
Abstract
In the context of controlled release drug delivery approaches, the systems providing zero-order release kinetics have special advantages. Through employing these systems, drug concentration could be maintained within the therapeutic window over release time; thus maximum effectiveness alongside minimized side effects of the drug are achieved. However, obtaining zero-order drug release is extremely challenging. One of the main obstacles is the fact that implemented devices should be designed to overcome the decreasing mass transfer driving force, especially, in polymeric systems in which diffusion mechanism is dominant. In this study, we developed a new configuration of a polymeric matrix...
Development of simple and efficient Lab-on-a-Disc platforms for automated chemical cell lysis
, Article Scientific Reports ; Volume 10, Issue 1 , 6 July , 2020 ; Saadatmand, M ; Eghbal, M ; Parsa Yeganeh, L ; Sharif University of Technology
Nature Research
2020
Abstract
Cell lysis is the most important first step for molecular biology and diagnostic testing. Recently, microfluidic systems have attracted considerable attention due to advantages associated with automation, integration and miniaturization, especially in resource-limited settings. In this work, novel centrifugal microfluidic platforms with new configurations for chemical cell lysis are presented. The developed systems employ passive form of pneumatic and inertial forces for effective mixing of lysis reagents and cell samples as well as precise fluidic control. Characterizations of the developed Lab-on-a-Discs (LoaDs) have been conducted with dyed deionized (DI) waters and white blood cells...
Hegel's ontology of power : the structure of social domination in capitalism
, Book
Cambridge University Press
2020
Design and Fabrication of a Centrifugal Microfluidic System to Cell Lysis
, M.Sc. Thesis Sharif University of Technology ; Saadatmand, Maryam (Supervisor) ; Eghbal, Manouchehr (Supervisor) ; Parsa Yeganeh, Laleh (Co-Supervisor)
Abstract
Cell lysis, as the first procedure of cell pretreatment, is a process that breaks cell membranes open thereby facilitating access to intracellular substances, such as DNA, proteins, and other components for further analysis to diagnose and treat diseases at early stages. Currently, there are several methods for cell lysis at macroscales. However, the time-consuming and expensive procedures as well as the large scal of the system are the main disadvantages of the systems. Recently, microfluidic systems have attracted considerable attention due to advantages associated with automation, integration and miniaturization of biomedical test protocols. Centrifugal microfluidics (Lab-on-a-Disc) is a...
Exact determination of the phase structure of a multi-species asymmetric exclusion process
, Article Journal of Statistical Physics ; Volume 100, Issue 5-6 , 2000 , Pages 999-1030 ; 00224715 (ISSN) ; Karimipour, V ; Sharif University of Technology
Kluwer Academic/Plenum Publishers
2000
Abstract
We consider a multi-species generalization of the Asymmetric Simple Exclusion Process on an open chain, in which particles hop with their characteristic hopping rates and fast particles can overtake slow ones. The number of species is arbitrary and the hopping rates can be selected from a discrete or continuous distribution. We determine exactly the phase structure of this model and show how the phase diagram of the 1-species ASEP is modified. Depending on the distribution of hopping rates, the system can exist in a three-phase regime or a two-phase regime. In the three-phase regime the phase structure is almost the same as in the one species case, that is, there are the low density, the...
Microstructure evolutions and mechanical properties of tubular aluminum produced by friction stir back extrusion
, Article Materials and Design ; Volume 65 , January , 2015 , Pages 74-79 ; 02613069 (ISSN) ; Movahedi, M ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
Aluminum tubes were successfully fabricated using a novel process of friction stir back extrusion (FSBE) known as one of the severe plastic deformation (SPD) routes. It was found that this process is capable to form a tube with a significant fine grained structure resulting from dynamic recrystallization phenomenon in the stirred area. Several regions were identified in the formed tube in which various microstructural evolutions occur, i.e. dynamic recrystallized (RX), static RX, and partially static RX zones along with extruded base metal. There was also no considerable change in the hardness and strength values of the formed tube with respect to those of the extruded base metal. However,...
Post deformation at room and cryogenic temperature cooling media on severely deformed 1050-aluminum
, Article Metals and Materials International ; Volume 24, Issue 2 , 2018 , Pages 401-414 ; 15989623 (ISSN) ; Kazeminezhad, M ; Sharif University of Technology
Korean Institute of Metals and Materials
2018
Abstract
The annealed 1050-aluminum sheets were initially subjected to the severe plastic deformation through two passes of constrained groove pressing (CGP) process. The obtained specimens were post-deformed by friction stir processing at room and cryogenic temperature cooling media. The microstructure evolutions during mentioned processes in terms of grain structure, misorientation distribution, and grain orientation spread (GOS) were characterized using electron backscattered diffraction. The annealed sample contained a large number of “recrystallized” grains and relatively large fraction (78%) of high-angle grain boundaries (HAGBs). When CGP process was applied on the annealed specimen, the...
Externally driven one-dimensional Ising model
, Article Journal of Statistical Mechanics: Theory and Experiment ; Volume 2012, Issue 2 , Feb , 2012 ; 17425468 (ISSN) ; Aghamohammadi, C ; Khorrami, M ; Sharif University of Technology
2012
Abstract
A one-dimensional kinetic Ising model at a finite temperature on a semi-infinite lattice with time varying boundary spins is considered. Exact expressions for the expectation values of the spin at each site are obtained, in terms of the time dependent boundary condition and the initial conditions. The solution consists of a transient part which is due to the initial conditions, and a part driven by the boundary. The latter is an evanescent wave when the boundary spin is oscillating harmonically. Low-and high-frequency limits are investigated in greater detail. The total magnetization of the lattice is also obtained. It is seen that for any arbitrary rapidly varying boundary conditions, this...
Mechanical properties of graphene oxide: A molecular dynamics study
, Article Fullerenes Nanotubes and Carbon Nanostructures ; Volume 24, Issue 9 , 2016 , Pages 594-603 ; 1536383X (ISSN) ; Sarkari Khorrami, M ; Sharif University of Technology
Taylor and Francis Inc
2016
Abstract
In this paper, the mechanical properties of graphene oxide are obtained using the molecular dynamics analysis, including the ultimate stress, Young modulus, shear modulus and elastic constants, and the results are compared with those of pristine graphene. It is observed that the increase of oxide agents (–O) and (–OH) leads to the increase of C–C bond length at each hexagonal lattice and as a result, alter the mechanical properties of the graphene sheet. It is shown that the elasticity modulus and ultimate tensile strength of graphene oxides (–O) and (–OH) decrease significantly causing the failure behavior of graphene sheet changes from the brittle to ductile. The results of shear loading...
Application of PSA Methods in the Reliability Analysis of EPSS of Busherhr NPP in case of Station Black Out
, M.Sc. Thesis Sharif University of Technology ; Ghofrani, Mohammad Bagher (Supervisor)
Abstract
LOOP accident is one of the most important accidents in NPPS and it leads to loss of power supply of the RCP pumps which are the main pumps of primary circuit. Subsequently trip of the rector occurs. In safety analysis, concerning worst conditions, assumes that after a small period of time, main generator of plant stops working and loss of AC power supply of all power plant loads including safety systems ocures. To control of this accident, it’s necessary to startup and load backup power supply system (EDGs) for at least one safety channels, if not, the accident moves forwards and becomes S.B.O accident which is more important accident that ends to core damage because of stops working of all...
Strategic Requirements of Petroleum Upstream Supply Chain Management
, M.Sc. Thesis Sharif University of Technology ; Fatahi Valilai, Omid (Supervisor)
Abstract
Nowadays the concept of competition in business has been expanded from enterprises to supply chains. For success in this competitive environment, it should be established complete coordination and synchronization between different rings of the chain in both strategy and operations. The supply chain management is a factor for achieving to this purpose. Effective supply chain management, especially in complex supply chains like petroleum upstream supply chain, requires to strategic factors that propel the chain to the long term goals. Unfortunately, it is showing off the vacancy of attending to this case in the literature. This thesis tries to fill this gap in literature with a new approach...
Social Networks, Collaboration Graphs and Random Graphs
, M.Sc. Thesis Sharif University of Technology ; Mahmoodian, Ebadollah (Supervisor)Finding the best alternative for plugging problem in MEG regeneration unit using AHP method
, Article Society of Petroleum Engineers - SPE Russian Oil and Gas Technical Conference and Exhibition 2010, RO and G 10, 26 October 2010 through 28 October 2010, Moscow ; Volume 1 , 2010 , Pages 48-54 ; 9781617820441 (ISBN) ; Karimkhani, B ; Farhadi, F. A ; Sharif University of Technology
2010
Abstract
MEG regeneration and injection unit regenerates aqueous MEG. The main goal of this unit is approaching desired MEG concentration whereas MEG loss via removed water is a big issue. Circulating glycol is polluted with Ca++ and Mg++ which forms carbonate scale and causes plugging of pipe lines, filters, lean/rich exchanger, still column packings and reboiler tube bundle and decreases their efficiency, consequently increases MEG loss via top product. Different alternatives exist according to similar experiences around the world. Using specific criteria and AHP (Analytical Hierarchy Process) method priority of these alternatives has been found. Results are as following: 1. Increasing number of...
Evaluating Dependability of Open-Source File Systems Considering Organizations of Hard Disks and Solid-State Drives
, M.Sc. Thesis Sharif University of Technology ; Asadi, Hossein (Supervisor)
Abstract
Storage subsystem is one of the most important components of a computer system. As more valuable information such as bank transactions are being stored in storage subsystems,occurrence of an unrecoverable error can lead to a much bigger problem. A storage subsystem can be divided into software and hardware part. Previous works focused on fault injection in the higher layers of the storage stack and didn’t consider fault injection at the device driver level. In this thesis, the dependability of storage stack is evaluated using fault injection at the device driver layer. Various hardware and software faults that can occur in hard disks and solid state drives are studied and dependability of...
About Space Time
, M.Sc. Thesis Sharif University of Technology ; Rastegar, Arash (Supervisor)
Abstract
Einstein's general theory of relativity is an admirable successful and unifier geometrical modeling among concepts of space, time and gravity. This theory along with special theory of relativity made a massive change in our physical view and this, especially in its historical context, has deep and interesting consequences in man's philosophical viewpoint which can be studied. Some parts of this thesis relates to these consequences. Some of these interesting consequences may be hidden by computional or mathematical viewpoint and often these equations do not contain enough intuition. in one part, we provide a formulizatin of Einstein's equaion that is intuitional which can be translated in...
Tropical Algebraic Geometry
, M.Sc. Thesis Sharif University of Technology ; Rastegar, Arash (Supervisor)
Abstract
Tropical algebraic geometry is a fairly new branch in geometry which is called so in honor of Brazilian mathematician Imre Simon who was pioneer of this field.The set equipped with the addition and multiplication is a semifield.Algebraic geometry objects like algebraic varieties can be defined over.Polynomials and rational functions are defined over.The functions that they define are piecewise linear and concave functions and the set of points where they are nonlinear is a tropical variety which is a concave polyhedral. Thus, tropical algebraic geometry is a piecewise linear version of algebraic geometry.Another approach to tropical algebraic geometry comes back to the works of Russian...
Evaluating the Effect of Crumb Rubber on the Fracture Properties of Asphaltic Materials Using a Standardized Composite
, M.Sc. Thesis Sharif University of Technology ; Motamed, Arash (Supervisor)
Abstract
Fatigue cracking has a major impact on the performance of flexible pavements. Many test methods have been established to evaluate and estimate the fatigue life of asphaltic materials. Most of these test methods cannot successfully examine the fatigue properties of asphaltic materials. Recent studies demonstrate that using a standardized composite, which consists of glass beads and asphalt binder, can simulate the stress states that binder experiences in the field. This research used standardized composite to investigate the effect of crumb rubber on the fracture properties of asphaltic materials. To validate the test results, the authors conducted fracture tests on the Fine Aggregate Matrix...
Novel View Synthesis Using Light Field Camera
, M.Sc. Thesis Sharif University of Technology ; Amini, Arash (Supervisor)
Abstract
In the last two decades, novel view synthesis has become increasingly important in the movie and game industries. The new generated views correspond to virtual viewpoints, where no real camera has taken snapshot. Depending on the amount of available information from the scene, different approaches have been proposed to create novel views. If the depth information is available, then by knowing camera relative motion, novel views can be constructed. The conventional cameras only record the intensity of the captured scene, and discard the depth information. In the recent concept of light field cameras, by locating an array of micro-lenses between the camera sensor and the main lens, one can...
Developing a New Method to Evaluate and Quality Control of Chip Seal
, M.Sc. Thesis Sharif University of Technology ; Motamed, Arash (Supervisor)
Abstract
Chip seal is one of the most economical pavement maintenance practice that extends pavement life. To ensure chip seal good performance several quality control methods have been developed. However, most of these methods are qualitative and only measure the stone loss under a certain number on loading. This research developed a new method for quality control of chip seal, based on the assumption that characteristics of the bond between chips and pavement surface play a key role in chip seal performance. To validate this test method, the authors used a wheel track loading test. The results from this research clearly showed that the characteristics of the bond between chips and pavement surface...
Investigating the Effect of Various Additives on the Curing Time of Chip Seal and Chip Seal Treatments in Different Climate Conditions.
,
M.Sc. Thesis
Sharif University of Technology
;
Motamed, Arash
(Supervisor)
Abstract
Recently, a new method to investigate chip seal performance has developed by a research team at Sharif University of Technology. This study investigates the effect of various additives such as CRM, SBR Latex, Hydrated Lime and Ordinary Portland Cement (OPC), on the curing time of chip seal by this method. In addition, the chip seal treatments were investigated in different climate conditions like Wet and Wet-Freeze zones. The overall performance of mixture specimens evaluated using creep loading test. In fact, the bonding properties between aggregates and surface of Hot Mix Asphalt measured. The test results were analyzed by using of the work and time parameters. These parameters were...