Sharif Digital Repository

Dialysis which is an imperfect but most common treatment option for renal failure is divided into two main types:"peritoneal dialysis" and "hemodialysis". Peritoneal dialysis uses a fluid that is placed into the patient's stomach cavity through a special plastic tube to remove excess waste products and fluid from the body.Hemodialysis uses a special type of filter to remove excess waste products and water from the body and is divided to two groups :Clinical and Home.During hemodialysis, blood passes from the patient's body through a filter in the dialysis machine. In this Study first the basic aspect of renal failure and principle of dialysis process are described.Then information about... 

Modeling is one of the most important steps in analysis and design of structures. Most of the time behavior of floor diaphragms is assumed completely rigid in their plane in order to simplicity in practical design. Although this assumption leads to acceptable results in analysis and design of conventional buildings, erroneous results may assess in some particular buildings—for instance narrow buildings with stiff end walls. Accordingly, behavior of these buildings in future earthquakes opposes those were predicted in design phase, and they are so vulnerable since in-plane deflection of floor diaphragms are striking which cannot be ignored. This thesis investigates the significance of... 

This thesis deals with the financial risk management and coordination of supply chain members. To investigate this issue, two echelon supply chain consisting of one manufacturer and one retailer with a newsvendor inventory policy for a period is considered. The mathematical modeling has been used to find the exact answer. MATLAB software for solving and scenario generation is used for the analysis. In the proposed method, financial risk management, partial trade credit policy, coordination of supply chain members and cash discount for retailers, have been considered. According to the proposed method, the manufacturer can determine immediate payment at the start of the trade credit period... 

The acidizing operations have significant impact on productivity and production of oil and gas wells, so that wells having shell or regional damage are good candidates for well stimulation operations which could result in significant increase for efficiency or injectivity. Generally, the neural networks are nonlinear learning mathematical systems. In this project consists, At first, wellhead data of acidizing operation are collected in two Gachsaran oil field (38 wells) and Nar and Kangan gas field (35 wells). Generally, the neural networks are nonlinear learning mathematical systems. In the neural Network by using two algorithms, back propagation algorithm and Quick Propagation algorithm... 

The Standard Model ΛCDM which includes cold dark matter and cosmological constant components provides a good fit to a large span of cosmological data and large scale structures. Recent results of local measurements of Hubble constant rely on observations of type 1A supernovae have shown 4σ tension comparing H0 to the value inferred from cosmic microwave background observations assuming ΛCDM. The Hubble parameter appears in the cosmic microwave background as one of the standard cosmological model parameters. If these observations are not the result of statistical or systematic error, They could represent new physics beyond the standard ΛCDM cosmological model. The purpose of this thesis is to... 

Multiverse scenario has been recently addressed by physicists and they have found it useful in many areas of physics. In this dissertation, I have treated some issues about multiverse such as the kinds of multiverses, the arguments for or against multiverse, areas in which multiverse is introduced, etc. This dissertation has six chapters and an appendix. In the chapter one, some classifications of multiverse is introduced, and also some definitions of the concept of a world is presented. Then, my classification and definition of a multiverse and a world is introduced. In the chapter two, the concept of possible worlds in philosophy and its relationship with multiverse hypothesis is examined.... 

The concurrent flow of oil and water is a common occurrence in the field of multiphase flow in different fields including petroleum industry. In oil and gas, production engineers often face a situation in which more than one phase is flowing through the producers. In such conditions an accurate assessment of pressure loss inside the well plays a vital role in efficient and effective production planning. Changes in well orientation, wellbore diameter, reservoir and fluid properties as well as fluid flow rates are among parameters in which will affect the flow patterns that can occur inside a well during its life time. These flow patterns are created as a result of a competition between... 

Casing design is one of the most expensive parts in the drilling of oil wells, and any cost reduction with the basic design of these casing strings will significantly reduce the total cost of the operation. In recent years, occurring scenarios-based casing design has become popular; Because in many cases, it eliminates non-occurring scenarios such as gas kick and saves on drilling costs. In this study, we have tried to investigate all scenarios that may occur during the lifetime of the well, whether drilling or production, and for each well, based on its own field information, possible scenarios for each casing part are selected separately and the applying loads are calculated. For this... 

Electromagnetic wave scattering from objects is one of the most important problems in applied electromagnetics. Usually the electromagnetic scattering characteristic from an object is analyzed with the assumption that the object is in free space. If the object is not near other objects or surfaces this is acceptable. However if the object is near other objects or surfaces then the interactions between the scattered wave from the object and surroundings can significantly alter the scattering characteristic from the object.In this thesis we have proposed a method for the analysis of electromagnetic scattering from an object in the presence of rough surfaces. This method is based on the... 

Non-destructive testing method is for detect specimen flaws such as (crack, porosity, impure, welding defects, corrosion etc.) without destruction the specimen under inspection. Particular characteristic of radiography is an image product from specimen inside under testing where help to identity and better comprehend at flaw nature. Photon scattering is one of important factor to reduce image quality and signal to noise ratio. Scattered photons can due toexistent ingredient in the radiography environment and curvature of material transmission pipe where cause the disorder creation in the radiography images. In this research, pipe radiography simulated using the TIC and TIR radiography...