Sharif Digital Repository

In this thesis we examine and study the transmission of Ultra Wide Band (UWB) signals over single mode fiber in a radio over fiber system. We begin by developing mathematical model for the key optical components employed in radio over fiber systems. The authenticity of these models is verified with experimental results. Following the above models as well as experiment results, the transmission of UWB signals over optical fiber is investigated. The impact of limited operating bandwidth and nonlinearity of the electrical to optical transfer function on UWB signals is examined. Two types of UWB signals, namely, multi-band orthogonal frequency division multiplexing (MB-OFDM) and impulse radio... 

This thesis deals with the development of a hypothetical micronized powder factory and trying to test and engage in this hypothetical development of the following plant, it considers following factors:
1-Domestic & International market
2-Plant location
3-Plant design & development
a.machinery
b.technology & equipment
c.human resource
d.environment
e.packing
4-raw material
5-shipping & transport
To evaluate above factors the UNIDO methodology is used in this research work. The UNIDO methods are using a process by which feasibility studies of production facilities or plant are base on. After reviewing a variety of factors, ranging from financial... 

The methodology proposed by UNIDO , to investigate feasibility study of industrial project, is a useful tool in pre-investment decision making. In this work feasibility of investing on "Gas To Liquid" GTL Plant of Asalouye is investigated. Having gathered required information, including gas field potential, required technology and machineries, cost of investments , required manpower to run the UNIDO methodology is used to investigate the investment, the result of the work shows that the project is feasible and it would have internal rate of return of 24% ( by sale cost= 81 $ per barrel of GTL product)  

Water hammer is a pressure surge or wave resulting when a pressurized fluid in motion is forced to stop or change direction suddenly. This phenomenon can cause great amount of damage to the system and should be considered in designing of pipe systems. So, researchers have derived and proposed numerous models using different approaches. In this study a one-dimensional model using Time Splitting Method (TSM) and Double Sweep Method (DSM) are proposed to simulate transient flow in deformable pipes in networks. To solve the equations of momentum and continuity TSM is applied. In addition Brunone model is used to study the effect of unsteady friction on water hammer wave shape and attenuation. To... 

This thesis is devoted to prove the existance of solution and structure of solu­ tion for some partial differential equations by using some modern topological and variational thechniques. Taking direction from the literature, this thesis is interested in existence, uniqueness, blow-up in finite time for some evolution equations, multiplicity and radial solution for certain elliptic partial differential equations.-Employing Fibrering, Galerkins, Mountain Pass-Lemma and lions com­ pactness Lemma are sharp in this thesis to prove the exsistence and multiplicity of solutions and overcome lack of compactness in some cases  

Aabsal Co. was established in north east of Tehran in 1956, under the name of Loab Iran Private LTD.  Co.  and  continued  its  activity  in  manufacturing  enameled  dishes,  bowl,  tea  pots  and  etc.  until 1964. In  this  thesis  we  have  paid  attention  to  basics  of  TPM  and  how  to  implement  PM  procedures.  First we have paid attention to all the maintenance forms and how these forms work together in the company, and then the relationship between departments sections like manufacturing and maintenance are considered. Finally we have attempted to implement TPM. For this purpose we have taken a section of the factory as a pilot plant and have started to implement TPM there to... 

In this research ,lean and agile indexes in S.G.S Co. are evaluated. This company is the first company in engineering and supplying automotive parts as well as the first supply chain management and organization of Saipa Group. In the part of evaluating the lean management level it is the developed model of the suggested approach by Jackson “implementing a lean management system” (Jackson, 1996). As S.G.S is engaged in servicing activities not in production, we have changed some factors in Jackson's methodology. Different with the last model, we got the results and used AHP method for getting the level in each key. Finally by using another AHP the lean index of the S.G.S Co. was identified.... 

In this thesis , we consider nonnegative (continuous) weak solutions of the porous medium equation with source , u_t-∆u^m=u^p, and p>m>1 .
Assume that, m>1 and 1< p/m u_t-∆u^m=u^p,xϵR^n ,tϵR
has no nontrivial, bounded radial solutions u≥0 .
In one space-dimensional, the conclusion of the result mentioned above remains true without the assumption of the radial symmetry. The proof is based on the intersection-comparison arguments , zero number argum- ents and a key step is to show the... 

Our problem is to evaluation state and form of a tracer passing through the vessel. Using this method, we can identify the effect of during used in some defected parts of body. This evaluation leads to in solving a Laplace equation with mixed boundary condition. Separating that problem, we reach to a collection of algebraic and linear equations. Solving this system, we approximate coefficients of the solution with a series the existence and uniqueness of and analytic solution has been proved using the Eigen functions finally, using numerical algorithms, we have interpreted the analytical solutions.
 

This thesis is based on articles [18,15]. Zhao [18] has studied a free boundary problem modeling the growth of tumors with drug application. In this model live cells are two kindes: proliferative cells and quiescent cells. This model consists of two nonlinear second-order parabolic equations describing the diffusion of nutrient and drug concentration, and three nonlinear first-order hyperbolic equations describing the evolution of proliferative cells, quiescent cells and dead cells. He has proved that this free boundary problem has a unique global solution. Tao and Chen [15] have studied another free boundary problem modelling the growth of an avascular tumour with drug application. The... 

Selective withdrawal from water and settlement reservoirs and tanks is necessary for water and environmental systems. Perforated pipes can be used for selective withdrawal within the length of these reservoirs. In this method, the lateral inflow through perforations leads to the outlet of the pipe that is placed in a depth of fluid. In relation to the hydraulics of perforated pipes, most studies are about drainage pipes and perforated pipes that are used as wellbores in horizontal wells, but application of these pipes have not been investigated in submerged situations. Capacity estimation of perforated pipes based on inside diameter of the pipe, material of the pipe, perforations of the...