الفهرس 
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Abstract
We are classifying the various process to a family groups as (shearing processes, bending processes, and nibbling processes) to know the most process which has the maximum number of defective items, and utilizing from this point by attracting attention to this process or modifying it to overcome the reasons lead to defects occurrence or at least decreasing it in the case we can`t prevent that reasons completely.
We apply this thesis for years 1997, 1998 and made a comparison with the results for year 1996 as a reference year. We used Preto diagram and Ishikawa (Cause-and-effect) diagram which are two tools from the seven quality tools to help us to understand the most frequently occurring defect and then, we made a break down analysis for this defect to fix the root cause for this defect. We use the T-Test to check if there are a significant difference between the results of years 1997 and 1998 compared with results of year 1996 as a reference year, to see how these modifications improve the factory quality control system.
In this thesis we identify each part by a final product serial number or the final product business unit so every manufacturing part has been attached to the finished product to recognize it easy. The average number of the defects in these products studied to pay attention to the most defected during the various manufacturing processes. We can overcome these defects either by redesign or by searching for solutions, which help, to reduce the rate of defects and that leads to increase the productivity.
Finally we have tried to keep the output results in a simple form to be understood from all levels, for level of the top management the results aide to take right decisions which help increasing the productivity, while for the workers level when these results are declared and make a comparison with a various periods clarifying the level of performance which is reflected to keep spirits up and to motivate and raise the production quality and also raise the productivity.100
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This research is concerned with studying the effect of the electroless plating on mechanical, microstructure and corrosion properties of heat-treated electroless Ni-P , Ni-Co-P and Ni-W-P alloys .
Experiments were carried out in a glass vessel placed in a constant temperature water bath . The volume of plating solution to low Carbon Steel test specimen surface area (V / S ) was 15Cm3 / Cm2 in all cases . The variables embodied are : plating time and heat treatment temperatures.
The effect of changing plating time on the coating thikness for the three Ni-P , Ni-Co-P and Ni-W-P are studied.
The effect of heat-treatment on the Crystallization behavior of an electroless Ni-Co-P and Ni-W-P is also studied . For as plated samples the X-ray diffraction pattern of Ni-Co-P deposits showed microcrystalline deposit of P , Co, Ni , Ni5P2 , Ni7P3 & Ni3P . Well Crystalline of free Co & Ni and very crystalline and grain growth of Ni7P3 have been noticed for deposit heat-treated at 400 C for one hour , around this heat-treatment temperature the maximum hardness was achieved.
Heat-treatment for one hour at different temperature of electroless Ni-P , Ni-Co-P and Ni-W-P coatings showed excellent corrosion resistance of Ni-Co-P coating compared to Ni-P and Ni-W-P deposits. The obtained results show minimum surface wear occurred at 700 C .101
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To study the factors affect on composite material properties, were studied A220 Aluminum alloy was reinforced with SiC particles having the range 10 µm to 30µm and AI2O3 particles having size range 40µm to 60µm. The Metal Matrix Particle Composites (MMPCs) have been prepared by vortex method. The composites produced contained 7% and 20% weight percentage of both AI2O3 and SiC particles.
Hardness, tensile, fatigue, and wear were carried out to assess the properties of the prepared composites.
The Rockwell (B-scale) tests were carried out to study the hardness of the composites. The results showed that the hardness increase as a result of increasing the %wt. of reinforcement.
The tensile tests for the composites showed that, the addition of the particles increased yield strength and modulus of elasticity but reduced ductility.
Pin on disc dry sliding test is carried out to study the wear rate of the composites. The results showed that the addirion of the particles increased the wear resistance of Metal Matrix Composites (MMCs) compared to the unreinforced alloy, also the resistance to wear of composites are improved by increasing the weight fration of particles.
Scanning election microscopy was used to study the fracture surface of different types of tests carried out in order to investigate the different types of fracture surfaces.106
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Rib geometry was investigated experimentally and numerically in the present work to give an enhancement of heat transfer coefficient and fluid flow characteristics at equal mass flow rate and pumping power constraints through the cooling passage. The combined effects of rib pitch geometry, and alignment on the static pressure distributions, heat transfer coefficient, and friction losses around rib surface for fully developed turbulent flow in a rectangular duct with ribbed-walls were determined for Reynolds number ranging from 12,000 to 65,000. The rib height to channel hydraulic diameter ratio (e/De) and angle of attack were fixed at 0.081 and 900, respectively.
A special test rig was built up for fluid flow and heat transfer measurements, special simulated models were built up also, for flow visualization. The rib pitch to height ratios were 10, 20, and 40; the rib height to each duct hydraulic diameter (E/de) and duct height ratios (e/H) are kept at 0.081 and 0.0625, respectively. Three different rib shapes (trapezoidal, square, and inverted trapezoidal) were studied to investigate its effects on the fluid flow and heat transfer characteristics (local static pressure, reattachment length, friction losses, velocity distributions, and both local and average Nusselt numbers). ANSYS FLOTRAN CFD computer package was applied to predict the flow separation, recirculation, reattachment, and wake regions to support the experimental results from the flow visualization and the ribbed-duct measurements.
A full field measuring technique was used to measure the velocity vectors magnitude and directions. The fluid velocity could be determined from the predicted seeding particle velocity. The recirculating flow around the ribs with corner vortices upstream and downstream is difficult in measuring while that can be described by flow visualization. The flow visualization processes were carried out to simulate channels with two ribbed-walls (e/H = 0.0625) with different rib pitch to height ratios (P/e = 5, 10, 15, and 20) and shapes (square, trapezoidal, and inverted trapezoidal ribs).
A comparison between the experimental and computational results and also with the previous results was investigated where good agreement was found between them. Experimental correlations for the average static pressure coefficient (Cp). average friction factor (f), and average Nusselt number ratio (Nu/Nu,) were developed in terms of Reynolds number and rib pitch to height ratio for fully developed turbulent flow in ribbed-channel with different rib shapes.
The static pressure coefficient has lower values for inverted trapezoidal rib than square and trapezoidal ribs. The average static pressure coefficient on rib surface decreases as the rib pitch decreases. The static pressure coefficient for in-line rib alignment (symmetric) has lower values than those for staggered alignment and one ribbed-wall (asymmetric) has lower values than those for staggered alignment and one ribbed-wall (asymmetric) while it was independent on Reynolds number.
The local temperature distributions had lower values on the inverted trapezoidal rib surface than that on the grooved square rib. The grooved square ribs provide heat transfer enhancement in comparison with the solid square ribs by about 23%for asymmetric rib alignment. Also, the heat transfer augmentations of grooved square rib were about 2.46-2.66 and 1.22- 1.26 times those of the smooth duct and ribbed-duct with solid square rib, respectively, while pay about 8 times the friction loss penalty of smooth duct. The inverted trapezoidal rib increases the average Nusselt number ratio about 2.79-2.6, 2.77-2.55, and 2.05-1.788 times over that of smooth duct for p/e=10,20,and 40, respectively, while pay about 7.5 times the friction loss penalty of smooth duct, At same pumping power constraint, the inverted trapezoidal rib shape had a higher heat transfer enhancement at p/e = 20 than that at p/e = 10, this is reserved for same mass flow rate.
It could be concluded that, the rib shape has a high significant effect on the local heat transfer coefficient on rib surface where the heat transfer enhancement depends on the turbulent transport which was influenced by the rib shape while the frequency of flow acceleration had a no significant effect. 102
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The present work is an experimental investigation on a single cylinder-spark ignition engine, which is modified to run on either gasoline or/and natural gas, to investigate the effect of using natural gas as a fuel on engine cyclic variations.
The engine test rig used in this investigation is fitted with all the instrumentation required for evaluating engine performance such as power, mass flow rate of air and fuel, exhaust temperature and speed, and also the exhaust emissions of carbon monoxide and unburned hydrocarbons.
The test rig was also furnished with computer controlled data acquisition systems with a complete set of software for monitoring and recording the variation of cylinder pressure.
The tests are performed on the engine at idling and at low load conditions, where the variations are very clear and can studied easily.
During the tests, natural gas proved to be a good fuel for spark ignition engine. It is indicated through the results that the engine speed and mixture equivalence ratio has the greatest influence on cyclic variations. These variations decreased as the engine speed and the air/fuel ratio increase.
The use of natural gas generally has a positive effect in reducing these variations.
When natural gas is used as a fuel to investigate the effect of engine speed on cycle by cycle variation, the coefficient of variation of cylinder pressure decrease by a bout 44% compared with a gasoline as a fuel. Also for increasing engine speed the coefficient of variation is reduced by 29%, air to fuel ratio 39%, exhaust temperature 35%, carbon monoxide 50% and unburned hydrocarbon by 41%.
Also, when using natural gas as a fuel to investigate the effect of increasing air to fuel ratio on cycle variation, the coefficient of variation of cylinder pressure decrease by 48% compared with a gasoline as a fuel. Also for engine speed the coefficient of variation is reduced by 39%, air to fuel ratio by 32% exhaust temperature 39%, carbon monoxide percentage 65% and unburned hydrocarbon 40%.103
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Pipelines are generally externally protected against soil-side corrosion by a combination of protective coatings and impressed current cathodic protection. For the protection of the internal area of the pipelines, depending upon the corrosive tendency of the process fluids, corrosion control measures are adopted in the form of inhibitor dosing.
Considering the inherent hazard posed in the event of the failure of pipeline, corrosion monitoring of the external and internal surface is necessary for pipelines in spite of the fact that proper corrosion control measures like protective coating and cathodic protection have been implemented. Monitoring is required to ensure that all sections of pipelines are protected against corrosion (external and internal). It is also to assess the performance level of various control measures, and to thereby ensure that the corrosion prevention systems, e.g., the cathodic protection and protective coating are performing adequately as intended and affording complete protection.
Various causes of pipeline failures are discussed, and the methods for ensuring the safety and integrity of a system are described in detail. The capabilities and limitations of various techniques in use for monitoring the effectiveness of corrosion protection systems and for assessing the health of pipelines are discussed based on practical experience and established practice in the industry.
The thesis investigates the corrosion of ductile iron pipe under Kuwait environment. Experiments cover pipes used on both fresh water transport and sewage. The study emphasized that normal coating condition, corrosion in most of the tested pipes is within the allowed limits that recommended by the different standards.
The work has been extended to the study both adhesion and abrasion resistance especially for pipes used for sewage transport. This is because that such mechanisms of wear will affect the efficiency of pipe coating. Therefore, corrosion rate will exceed the allowed standard level. Recommendations for selection of a particular coating for both pipes applications for water pipe it is suggested to use epoxy internal lining while sewage pipes is better to be lined with pure Polyurethane.