Engineering Commons^™

Experimental Investigations Of Techniques To Enhance The Cooling Rate Of Hot Fluids By Utilizing Gallium As A Heat Sink Material, Abdallah M. S. Ghazal

Mechanical Engineering Theses

No abstract provided.

Numerical Analysis For The Hemodynamics In Unruptured Cerebral Aneurysms, Hashem Mhd Hicham Alargha

Theses

A cerebral aneurysm is a vascular disorder characterized by abnormal focal dilation of a brain artery which is considered as a serious and potentially life-threatening condition. Cerebral aneurysms affect around 2%-5% of adults and they are fatal and can rupture with an overall mortality rate of more than 50%. Through computational fluid dynamics investigation, this study is offering a closer look into the initiation growth and rupture of cerebral aneurysms. Four focus points are studied in this thesis which are sensitivity analysis of blood viscosity in aneurysms, the effect of cerebral aneurysm size on wall stresses and strain, hazard effects …

Numerical Validation Of Cooling Performance Of Phase Change Materials Integrated Into Heat Sinks For Electronics Cooling, Shaimaa Mohamed Abu Ayyan

Theses

This study aims to analyze the cooling performance of phase change materials (PCMs) integrated into metallic heat sinks (HSs) both experimentally and numerically. For the experimental part of the study, a test setup has been constructed to test PCM integrated heat sinks. The heat sinks are prepared as metallic containments having fins with fixed inter-fin spacing. The volume between the heat sink fins is filled with PCM namely: a paraffin wax, salt hydrate-calcium chloride and milk-fat, then the whole system is sealed for testing under various heat loads at 4W, 6W, 8W and 10W. Four modes of operation are experimentally …

Experimental Evaluate Gas Separation Using Ranuehilsch Vortex Tube, Ali Salah Omar Owiemer Omar Owiemer

Theses

Through experimental investigation, this study is offering a closer look into the performance of the vortex tube energy separation and a better understanding of the effect of the vortex tube length, diameter and internal tapering angle on the energy separation. Also the study addresses the effect of inlet pressure on the performance of the vortex tube and the effect of different working fluids (Air, H2 and O2). The vortex tube is a thermal static tube that was discovered by the French scientist George Ranque in 1933 and it is used to separate compressed gas flow into two different streams: one …

Preparation And Characterization Of Copper-Doped And Silver-Doped Titanium Dioxide Nano-Catalysts For Photo Catalytic Applications, Haya Abdel Ra’Ouf Ahmed Ra’Ouf Ahmed

Theses

The goal of this work was to improve the performance of TiO2 nanomaterials by increasing their optical activities by shifting the onset of the response from the UV to the visible-light region. Among the several ways to achieve this goal, doping TiO2 nanomaterials with other elements (e.g. metals) was selected to narrow the band gap and enhance the optical properties of TiO2 nanomaterials. In this work, we have prepared Cu-doped TiO2 and Ag-doped TiO2 nano-catalysts, characterized them and studied their properties, and the optical ones in particular. The Ag-doped TiO2 catalyst was prepared by the sol-gel method while the Cu-doped …

Carbon Black Mediated Conductive Polymer Composite, Mohamed Hussein Faris Ali

Accounting Dissertations

The central goal of this thesis is to produce electrically conductive nanocomposites made out of carbon black obtained from waste tires as filler into a polymeric matrix. Waste tires are discarded in substantial numbers on a daily basis, posing a significant environmental concern. By weight, about 25-35% of a tire is carbon black. Pyrolysis is a convenient and environmentally friendly process to produce carbon black from tires. Due to carbon black’s low density, high electrical conductivity and economical feasibility, this thesis investigates the electrical conductivity of nanocomposites that utilizes carbon black particles as fillers. As a result of its modified …

Carbon Black Mediated Conductive Polymer Composite, Mohamed Hussein Faris Ali

Theses

The central goal of this thesis is to produce electrically conductive nanocomposites made out of carbon black obtained from waste tires as filler into a polymeric matrix. Waste tires are discarded in substantial numbers on a daily basis, posing a significant environmental concern. By weight, about 25-35% of a tire is carbon black. Pyrolysis is a convenient and environmental friendly process to produce carbon black from tires. Due to carbon black’s low density, high electrical conductivity and economic feasibility, this thesis investigates the electrical conductivity of nanocomposites that utilizes carbon black particles as fillers. As a result of its modified …

Pbs Quantum Dot-Based Hetrojunction Solar Cells, Sawsan Khader Dagher

Dissertations

This study investigates the influence of nanoparticles (NPs) size on their optical properties, and the effect of combination of lead sulfide (PbS) quantum dots (QDs), with n-type and p-type NPs, on the photogenerated charge carriers transport across the heterojunction solar cell structure. PbS QDs, of a range of sizes, were synthesized using a co-precipitation process. In this study, p-type NPs, which are poly [3,4-ethylenedioxythiophene] –poly [styrenesulfonate] (PEDOT: PSS), copper oxide (CuO) and graphene oxide (GO); and n-type NPs which are zinc oxide (ZnO), titanium dioxide (TiO2), cadmium sulfide (CdS) and bismuth sulfide (Bi2S3), were synthesized and characterized by SEM and …

Magnetic Nanoparticles For Thermally Anoparticles Enhanced Heavy Oil Recovery, Hazem Elshorbagy Elshorbagy

Theses

A novel method of delivering thermal energy efficiently to reservoirs for heavy oil production is described in this study. The method uses magnetic nanoparticles that generate heat locally when exposed to a high frequency magnetic field oscillation via hysteresis losses. This concept is currently used in medical research to thermally kill cancerous cells. Electromagnetic heating is a n alternative method to heat heavy oil reservoirs without using water or steam. Using magnetic nanoparticles with electromagnetic heating would greatly reduce the energy requirement and would allow efficient propagation of heat into deeper regions beyond wellbore locality that are otherwise difficult to …

Conductive Polymer Blends And Their Use In Memory Devices, Mohammad Yousef Al-Haik

Theses

The aim of this project is to synthesize and characterize conductive polymers made out of blending nonconductive polymers with ionic liquids. An application to demonstrate the use of these novel conductive polymers is to create an organic memory device.

Attempts to synthesize conductive polymers have been reported in the literature; several of these approaches include doping a polymer with arsenic or iodine based dopant. In this work, ionic liquids, known as plasticizer, are sued as the dopant for non-conductive polymers. There are several advantages of employing the ionic liquids over other dopants, including the maintenance of organic based blends (both …

Study On Fracture Behavior Of Aa5083–H111 Friction Stir Welded Join, Mohammed El Sayed Allam

Theses

The fracture behavior of friction stir welded joints of aluminum alloy 5083-H111 was studied in this investigation. Different samples of stir welded joints at variable tool rotational speeds (1660 rpm, 850 rpm, and 675 rpm), different traveling speeds (24, 42, 55, 74, and 98 mm/min), and different tool pin shapes (cylindrical, tapered and threaded) were studied to investigate the effect of process parameters on the joint strength/load-bearing capacity. A series of tensile tests using an MTS machine, scanning electron microscope (SEM) analysis, and optical microscope analysis was conducted to study the effect of varying the rotational speed, traveling speed, and …

Fracture Behavior Of Cracked Full Scale Steel Pipes Used For Gas And Petroleum Industries, Jaafer Altarawneh

Theses

The fracture toughness of pipeline steel grade X65 was investigated utilizing linear elastic fracture mechanics analysis, K_IC testing according to non-standards techniques, as well as the elastic-plastic fracture mechanics analysis (J-Integral and crack opening displacement COD methods). The fracture toughness tests were conducted at full scale pipe used for gas and oil industry, circumferential surface crack were introduced to nine pipe specimens with different depths, crack/notch depths were selected to cover wide range of remaining material of the original pipe thickness, the original pipe thickness remain unchanged, a special fixture was manufactured to perform the experimental works, plane strain …

Impact Characteristics Of Nano Composites, Ammar Mohamed Al Omari

Theses

Nanocomposite materials have seen a significant increase in use and have created a revolution in high-performance structures. They exploit the properties of different materials which create structures that are stronger, stiffer, impact resistant and more durable against environmental factors. They can be tailored to have better electric, magnetic, optical properties, and be chemically, thermally and explosion resistant depending on the application. The current research study investigates the impact characteristics of polymeric based nanaocomposites strengthened with various types of nano and micro filler. An in-house designed impact testing machine was utilized to typify the impact characteristics of different nanocomposite materials through …

The Evolution Of The Long Term Performance Of Fiber Reinforced Composites Materials Based On Vinyl Easter Resin, Nasser Abdullah Ali-Al Ghailani

Theses

Fiber reinforced polymer (plastic) FRP composites are different from traditional

structural materials such as steel or aluminum since the an-isotropic nature of a Fiber _ reinforced composite material creates a unique opportunity of tailoring its properties according to the design requirements. With the accelerated change in the technological sphere, FRP composite materials

have taken a paramount importance in various structural applications, where they successfully replaced conventional materials such as steel. Such success is based on the advantages offered by composite materials such as a high strength to weight ratio. However one aspect that is still delaying full acceptance of these …