Large-Area, cost-effective, ultra-broadband perfect absorber utilizing manganese in metal-insulator-metal structure

, Article Scientific Reports ; Volume 8, Issue 1 , 2018 ; 20452322 (ISSN) Aalizadeh, M ; Khavasi, A ; Butun, B ; Ozbay, E ; Sharif University of Technology

Nature Publishing Group 2018

Abstract

Achieving broadband absorption has been a topic of intensive research over the last decade. However, the costly and time consuming stage of lithography has always been a barrier for the large-area and mass production of absorbers. In this work, we designed, fabricated, and characterized a lithography-free, large-area compatible, omni-directional, ultra-broadband absorber that consists of the simplest geometrical configuration for absorbers: Metal-Insulator-Metal (MIM). We introduced and utilized Manganese (Mn) for the first time as a very promising metal for broadband absorption applications. We optimized the structure step-by-step and compared Mn against the other best candidates introduced...

Simulation of Blood Flow Subjected to Magnetic Field

, M.Sc. Thesis Sharif University of Technology Aalizadeh, Farhad (Author) ; Moosavi, Ali (Supervisor) ; Shafie, Mohammad Behshad (Supervisor)

Abstract

Considering the fact that there is a blood flow inside the vessels it is possible that blood flow is always associated with fouling and this may decrease the blood flow when a blood vessel is injured, the cells of your blood bond together to form a blood clot. The blood clot helps you stop bleeding. Blood clots are made of a combination of blood cells, platelets (small sticky cells that speed up the clot-making process), and fibrin (protein that forms a thread-like mesh to trap cells). Doctors call this kind of blood clot a “thrombus.” We study the effects of different parameters on the deposition of Nanoparticles on the surface of a bump in the blood vessels by the magnetic field. The...

A route to unusually broadband plasmonic absorption spanning from visible to mid-infrared

, Article Plasmonics ; Volume 14, Issue 5 , 2019 , Pages 1269-1281 ; 15571955 (ISSN) Aalizadeh, M ; Khavasi, A ; Serebryannikov, A.E ; Vandenbosch, G. A. E ; Ozbay, E ; Sharif University of Technology

Springer New York LLC 2019

Abstract

In this paper, a route to ultra-broadband absorption is suggested and demonstrated by a feasible design. The high absorption regime (absorption above 90%) for the suggested structure ranges from visible to mid-infrared (MIR), i.e., for the wavelength varying from 478 to 3278 nm that yields an ultra-wide band with the width of 2800 nm. The structure consists of a top-layer-patterned metal-insulator-metal (MIM) configuration, into the insulator layer of which, an ultra-thin 5 nm layer of manganese (Mn) is embedded. The MIM configuration represents a Ti-Al2O3-Ti tri-layer. It is shown that, without the ultra-thin layer of Mn, the absorption bandwidth is reduced to 274 nm. Therefore, adding only...

Controlled drug delivery using the magnetic nanoparticles in non-Newtonian blood vessels

, Article Alexandria Engineering Journal ; 2020 Abu Hamdeh, N. H ; Bantan, R. A. R ; Aalizadeh, F ; Alimoradi, A ; Sharif University of Technology

Elsevier B.V 2020

Abstract

Fouling in blood flow is very common and may decrease the blood flow in human body and lead to critical health issues. Upon injury in a blood vessel, the body's defensive system triggers a process to create a blood clot called “Thrombus”, which prevents bleeding. Blood clots are formed by a combination of blood cells, platelets, and fibrins. In this study, we investigate a controlled drug delivery using the magnetic nanoparticles in blood vessels under the influence of magnetic fields. For this purpose the Maxwell and the Navier-Stokes equations for the system are solved. In contrary to the previous studies it is assumed that the blood is a non-Newtonian fluid. The number of particles has...

Toward electrically tunable, lithography-free, ultra-thin color filters covering the whole visible spectrum

, Article Scientific Reports ; Volume 8, Issue 1 , 2018 ; 20452322 (ISSN) Aalizadeh, M ; Serebryannikov, A. E ; Khavasi, A ; Vandenbosch, G. A. E ; Ozbay, E ; Sharif University of Technology

Nature Publishing Group 2018

Abstract

The possibility of real-time tuning of optical devices has attracted a lot of interest over the last decade. At the same time, coming up with simple lithography-free structures has always been a challenge in the design of large-area compatible devices. In this work, we present the concept and the sample design of an electrically tunable, lithography-free, ultra-thin transmission-mode color filter, the spectrum of which continuously covers the whole visible region. A simple Metal-Insulator-Metal (MIM) cavity configuration is used. It is shown that using the electro-optic dielectric material of 4-dimethyl-amino-N-methyl-4-stilbazoliumtosylate (DAST) as the dielectric layer in this...

Investigation of Removing Idiosyncratic Price Distortions On Manufacturing TFP in Iran

, M.Sc. Thesis Sharif University of Technology Motavasseli, Ali (Author) ; Nili, Farhad (Supervisor)

Abstract

Government intervention in markets may go beyond the market regulation. Interventions may cause some idiosyncratic price distortions. It means the relative prices of factors to become different among firms. Therefore, micro conditions for firms will be changed. These will result in misallocation of factor production between firms and change in manufacturing TFP. According to data from about 14000 medium and small industrial firms in Iran, removing misallocation of production factors (capital and energy) and output idiosyncratic distortions between industrial firms would result in 115 percent increase in manufacturing TFP.

The Impact Of Households Characteristics To Their Use Of Banking Services In Urban Areas Of Iran

, M.Sc. Thesis Sharif University of Technology esfandiari, Marzieh (Author) ; Nili, Farhad (Supervisor)

Abstract

The purpose of this research is the extraction of socio-economic factors (separation of household and household members) that affect the use of banking services in urban area of Iran. In this study we used data of the "family access to financial services in urban areas of Iran in 1387" that has been sampled by the department of economic statistics of central bank of Iran. The statistical information of this organization is in form of completed questionnaires and based on household addresses in a city and contains of 6055 urban household's information. In this project 15922 persons have been studied in urban households include the caretaker and the other family members. In addition to...

Lead Time Quotation and Lot Sizing in Production Systems

, Ph.D. Dissertation Sharif University of Technology Mokhtari, Ghasem (Author) ; Kianfar, Farhad (Supervisor)

Abstract

Due date assignment for customer orders has been studied in various production environments. In this thesis a production system is considered in which the orders of several customers are produced in a single lot because of the economy of scale. If a lot is completed before receiving customer orders, inventory carrying cost is incurred. On shortages, a due date is quoted to customers and lead time quotation cost is incurred. The due date may not be met because of (lead-time) uncertainty in production system. Hence if the order is delivered after its due date, tardiness cost is charged. The literature reviews show that such a model is not considered by other researchers. Two different problems...

A Model for Hierarchical Production Planning in a Make-to-order System

, M.Sc. Thesis Sharif University of Technology Alavi, Behrouz (Author) ; Kianfar, Farhad (Supervisor)

Abstract

A hierarchical production system in make-to-order environment is presented in this thesis. This production system is consisted of three different decision making levels. Maximum acceptance for production within customer specified time interval was done in the first stage, which is called order arriving stage, based on different client criteria, type of demanded product, and production system constraints. A new hierarchical decision making structure for accepting or rejecting arriving orders is proposed in this level. The output of this acceptance level is orders having maximum production system defined criteria, and minimum production cost along with order delivery time with minimum delay is...

Kinetic Modeling of Propane Dehydrogenation on Industrial Pt-Sn/γ-Al2O3 in Presence of Oxygenated Compounds

, M.Sc. Thesis Sharif University of Technology Barghi, Bijan (Author) ; Khorasheh, Farhad (Supervisor)

Abstract

The study on the propane dehydrogenation process has been receiving significant attention due to the growing demand for propylene. The aim of this research is to develop an appropriate kinetic mechanism for dehydrogenation of propane over an industrial Pt–Sn/γ-Al2O3 catalyst in the presence of a very small amount of water. The reaction is carried out over the temperature range of 575 – 620 º C at atmospheric pressure. The results showed that a small amount of water and methanol can improve the performance of catalyst and also, increase the selectivity to COx. Addition the 0.5, 0.45, 0.3 water and 0.1, 0.05, 0.02 methanol are the optimum amount of these oxygenated compounds in order at...

Assembly Line Balancing with Sequence Dependent Setup Times

, Ph.D. Dissertation Sharif University of Technology Yolmeh, Abdolmajid (Author) ; Kianfar, Farhad (Supervisor)

Abstract

In recent years in assembly line balancing area many researchers have focused on identifying and modeling real world situations in assembly lines in order to obtain more suitable model. As a result many generalized models have been developed in assembly line balancing area. However, designing efficient algorithms to solve these generalized problems has just begun. In this study it is aimed to design efficient algorithms to solve one of these generalized problems. Specificcally two hybrid genetic algorithms (GA) are proposed to solve assembly line balancing problem with sequence dependent setup times. Scheduling of tasks in the stations has been less considered in the literature of assembly...

Multi-period Project Portfolio Selection and Scheduling with Uncertainties

, Ph.D. Dissertation Sharif University of Technology Rafiee, Majid (Author) ; Kianfar, Farhad (Supervisor)

Abstract

In this thesis, a multi-stage project portfolio selection and scheduling problem in an uncertain environment is modeled, analyzed and solved. Moreover, we investigate the situations in which a project manager is confronted to a large number of projects to be selected and scheduled while the required resources of the projects are limited and renewable. The aim is to maximize objective function which is the net present value of the profit of the projects. To solve the mentioned problem, we introduce a multi-stage stochastic programming. For the reason that, in real problems, optimization problems that included all restraints are large scale and have computational complexity, these problems are...

Kinetic Modeling of Hydrocracking of Synthetic Wax from Fischer-Tropsch

, M.Sc. Thesis Sharif University of Technology Naseri, Fatemeh (Author) ; Khorasheh, Farhad (Supervisor)

Abstract

Fischer-Tropsch process (FT ) is one of the most important processes gas-to-liquid (GTL) conversion. This process converts synthesis gas into hydrocarbons. Depending on the catalyst and operating conditions of the process, heavy paraffins (Wax) are the most important products in this process. These products can be used to heavy paraffin catalyst hydrocracking in a process for the production of diesel fuel and gasoline to lighter products are suitable to be converted. The aim of this project is to develop a suitable kinetic model to describe the process of producing heavy paraffin hydrocracking process Fisher - Tropsch to be lighter products. In this regard, each 5 continuous mass model...

Mathematical Modeling of Fixed bed Reactor for Oxidative Dehydrogenation (ODH) Process of Light Paraffins

, M.Sc. Thesis Sharif University of Technology Darvishi, Ali (Author) ; khorashe, Farhad (Supervisor)

Abstract

An industrial scale reactor for light olefinsproduction was modelledusing the oxidative dehydrogenation (ODH) of light paraffinsin a multi-tubular reactor system involving 10000 small diameter tubes immersed in a shell with proper liquid-cooled flows. Here a theory-based pseudo-homogeneous 1-D model describing the operation of a fixed bed reactor for the ODHparaffinstoolefins over a Ni-Nb-O mixed oxide catalyst (for ethane) and over a V2O5/γ-Al2O3catalyst (for Propane),was employed. The paraffin and oxygen conversions, gas process and coolant temperatures, as well as other parameters affecting the reactor performance, including pressure, were examined. Furthermore, the applied model showed...

String Theory Discription on Non-Relativistic QFT

, Ph.D. Dissertation Sharif University of Technology Vahedi, Ali (Author) ; Ardalan, Farhad (Supervisor)

Abstract

In this Thesis we study the string theory discription of non-relativistic quantum ?eld theories.In other statement we study the duality between gravity and gauge theory with non-relativistic symmetry.We discuss that this duality works in non rel- ativistic sense.We study two kind of non-relativistic theories that one of them camefrom string theory and other model obtained by special transformation of original relativistic theory and we see that how duality can be work for these models.Also dual picture of semi-classical string in the background that found from string theorystudied.We also study the motion of particle in a hot plasma and we ?nd a sign of non-relativisic duality really works

Using Time Series and Planning Uncertain Demand in Supply Chain with System Dynamics Approach

, M.Sc. Thesis Sharif University of Technology Rezaei, Davoud (Author) ; Kianfar, Farhad (Supervisor)

Abstract

In the field of supply chain, management constantly seeks to adopt strategies for realizing its targeted objectives. The supply chain, therefore, includes integrated production-distribution processes with all effective parts where proper management requires a comprehensive and dynamic approach. It is necessary to meet required items at required time. This becomes more important with the supply systems providing items. On the other hand, the difficulty of supply chain management, decisions, and policy-making can be increased by a wide range of conditions such as changes in demand. Thus, a comprehensive approach is needed to take the present dynamics into account. The current paper develops a...

Kinetic Modeling of Coke Formation in PDH over Pt-Sn/Al2O3 in Presence of Oxygenated Additives

, M.Sc. Thesis Sharif University of Technology Samavati, Abolfazl (Author) ; Khorasheh, Farhad (Supervisor)

Abstract

Propylene, as one of the most important raw materials of petrochemical industries, is produced through different methods. One of the major methods is propane dehydrogenation. This reaction is endothermic and many by-products will be produced in high temperature. Therefore catalytic dehydrogenation is preferred. Reduction in catalyst's activity and too many side reactions are the most important problems. Coke formation is the most effective reason of deactivation. Main source of coke is propylene. Experiments show that very small amount of water presence within reaction can reduce rate of coke formation. Water content growth does not always increase activity. If water be more than optimum...

Risk Management and Cash Flow In Banks

, M.Sc. Thesis Sharif University of Technology Samiei, Alireza (Author) ; Kianfar, Farhad (Supervisor)

Abstract

Asset and liability management is a method for optimizing cash flows of input and output of a bank . The model for optimizing the balance between liability and assets of a bank is presented in this research. Bank asset liability management and planning can be considered at the same time. In tjis model , all assets and liabilities in the bank balance sheet are discussed under different objectives and requirements , such as legal and administrate requirements, market condition, risk rate etc

Using Decision Analysis Concept to Implement Variant Process Planning System

, M.Sc. Thesis Sharif University of Technology Shokrzad, Reza (Author) ; Kianfar, Farhad (Supervisor)

Abstract

In Computer-Aided Process Planning, there are two ways of manufacturing called Variant Manufacturing and Generative Manufacturing. Variant Manufacturing is based on a data base from a part family for a project. The part family is made in a series of root sheets regarding the final form of the intended part. The data base is updated after the manufacturing of each part. In order to make the system intelligent, one can use the OPITZ coding system that specifies the geometrical form, geometrical details and part manufacturing operations in a 13-digit number. The aim of this research is to choose the best machining parameters according to time and cost, that, based on the basic principles of...

Studying and Comparing Agile and Lean Supply Chain Models and Determining the Optimum Model Using Genetic Algorithm

, M.Sc. Thesis Sharif University of Technology Daei, Mohammad (Author) ; Ghasemi, Farhad (Supervisor)

Abstract

As you know in lean supply chains, it is tried to: reduce the wastes of resources and achieve more production with lower consumption of resources. This system is very well suited for many supply chains in which the final determinant factors are price and quality. In contrast, recently, the concept of agile supply chain has been introduced, insisting on flexibility and high service level. Opposite to lean supply chain, agile supply chain needs safety stock to be able to respond to market’s changes.
Regarding the dissimilarities of these models –including the disagreement in the allocation of safety stock to nodes– In this thesis, in addition to studying and comparing these two approaches,...