Sharif Digital Repository

One of the miscellaneous units that are frequently used in water and wastewater systems is flush tank. Flush tank increases the self cleaning velocity in the conduit, and helps to clear the conduits from deposits and contaminations. While these units have been used for many years, there is not enough information about the hydraulic performance of these units in respect to the discharge, distance from the tank and the pipe hydraulics. In this paper the experimental results from observed hydrographs at different distances from the flush tank in a pipe has been presented. The variables include; volume of releasing water (or inlet hydrograph), upstream head, pipe diameter (3 and 4 cm), pipe... 

Activated carbon, as an adsorbent with a high adsorption capacity and low cost, has many applications in liquid and gas adsorption processes. Among the adsorption of liquid phase, there are examples of drinking water purification, wastewater treatment, food industry, brewery, chemical separation (acids, amines, glycerin and glycols), enzymes ... and in adsorption from the gas phase there are examples of removing toxic compounds Containing sulfur and recycling sulfur, purifying biogas, use in gas masks, etc. Various materials can be used as raw material to make activated carbon. Materials such as walnut, almonds, coconut, pine, corn, etc. In this thesis, a feasibility study on the production... 

Pharmaceutical waste has attracted considerable attention, in the Past two decades. These pollutants had not previously been detected in the environment. In fact, the concentration of pharmaceuticals became a matter of concern after the increase in the production and consumption of drugs. Nowadays, considering their higher consumption and more developed detection technologies, they are found in waste water, treated water, rivers, etc. The purpose of this research is to study treatment of a Synthetic waste water contaminated by Diclofenac and Ibuprofen in a Moving Bed Biofilm Reactor. An aerobic Moving Bed Biofilm Reactor (MBBR) with the volume of 8.5 liters and Kaldness packing filling ratio... 

Spent Caustic is the waste resulting from scrubbing of hydrocarbon streams with caustic solution. A thorough research on wastewater treatment to be performed at Tehran Oil Refinery in order to eliminate acid gases such as CO2 and H2S from LPG obtained from scrubbing given the fact that these gases are not eco-friendly, and the current systems of wastewater treatment are inefficient. Therefore, after investigating different methods used in Spent Caustic treatment, WAO method has been chosen to treat the wastewater at Tehran Oil Refinery. In this method, wastewater is oxidized with air at high temperature and pressure to reduce its COD. However, its high cost and operational difficulty of... 

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... 

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.... 

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.
 

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... 

ISO 10303 Standard also known as STEP, is an standard in the domain of mechanical manufacturing that describes data relating to drawings, design, machining, process planning, engineering and other aspects of product which all together can describe the entire life cycle of products. However, as this standard is newly born and developing these data models are expensive and time consuming, so far, no data model for description of cutting tools is developed. In this project we study the STEP parts and protocols to understand how data is stored. We study EXPRESS Modeling language, the language developed as part of the STEP standard which is the official language of data modeling in STEP. And use... 

Decision making is one of the most critical issues in engineering field. The Axiomatic Design is recently known as one of the most robust tools for decision making task. Axiomatic design is a engineering theory that provides a systematic framework for decision making using two axioms. These two axioms called Independence and Information axioms are both used to do the task.In this thesis, the information axiom is used to select the best machine (operation) for manufacturing cylindrical parts. To do that, three criteria including surface roughness, dimensional accuracy and cost have been chosen.Finally a comparison to the result of this methodology and the result of Analytical Hierarchy... 

Nowadays, because of high volume and growth of data in industrial organizations and productive factories, registration and storing of data have forgotten manual and tradition styles for which using automation and mechanized machinery and systems has been a necessary task. In order to reach to this revolution, need to some tools, facilities and methods which can fulfill this requirement is felt strongly. Therefore, high volume of data is considered as an advantage because based on precise analysis it is possible to make logical management decisions with less risk. During last years, statistical and numerical methods and simulation were used to discover knowledge and information when one of... 

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... 

In competitive environment of quick market changes, developing an interoperable manufacturing system is a necessity. Process planning as a connection link between design and manufacturing, has never been able to integrate these up/down stream activities and in spite of employing computer systems, CAPP’s information has been managed in an isolated manner. To realize interoperability, the exchange of part and product data must be independent of their platforms. There are two basic approaches for this purpose: i) Utilizing interface and ii) Utilizing neutral formats. STEP (Standard for the Exchange of Product data) plays a significant role as a neutral data model to integrate design,... 

Nowdays, many of communication systems working together. The fist part of each communication system is related to separating a desired part of system input signal. This is called channelisation. Channelization is a process where single, few, or all channels from a certain frequency band are separated for further processing. The separation of single channel is usually done by down-conversion followed by filtering and optional sample-rate conversion. A straightforward implementation for multi channel sepration, which is also the traditional implementation of wideband channelizer, is to simply use a single-channel channelizer for each channel. A few applications require that an input signal be... 

Today’s businesses strategies are changing from traditional point of view to globalization and distributed enterprise. Companies have to consider flexibility in term of quantity and variety. They have to manage and organize the product development chain where low cost resources are available. Therefore, enterprises and companies should facilitate the flow of information and increase the interoperability between distributed agents. The main information flow occurs in CAD/CAM/CNC chain. Information flow at the end of the chain has always been the main obstacle to enable interoperability. Old Standards for programming CNC machine tools are the main problem to exchange data and facilitate... 

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  

In this paper, the Hopfield neural network models have investigated. Also the similar model with time -varying delays and constant coefficients has considered and with establishing some criterions, existence solution and it's exponential stability of the solution is investigated. Moreover, some special conditions for exponential stability by impulses and exponential stability by periodic impulses are obtained  

In this thesis, three mathematical models are considered for the viral dynamics of HIV-1. The first model is an HIV infection model with saturation infection and intracellular delay, which forms a three-dimensional differential equations system, the second model includes an eclipse stage of infected cells, The viral dynamics of this model is described by four nonlinear ordinary differential equations, and finally, we study a delayed six-dimensional HIV model with CTL immune response, in fact, the main issue is the analysis of the second model (model including an eclipse stage for the infected cells).In this thesis is obtained sufficient conditions for persistence or eradication of the...