Essential to human life is water. Drinking water, in particular, is of utmost significance for all living creatures including man. An examination of the transmission process of drinking water reveals the high importance of pipe lines. The water pipe lines delivering water today encounter serious problems. Corrosion has caused deterioration in pipe lines, which contributes rust to drinking, a serious water quality problem. In addition, pipe line failures have caused social issues, such as suspension of water supply. This study developed a model to estimate the life expectancy and residual life of a pipe based on the assessment of failure risk in order to evaluate the current failure possibility and predict when the pipe will reach the point of failure. The developed model for estimation of residual life by failure risk was used to assess the failure risk of water pipes based on the general data and pipe sources of the Chang Won City water pipes. The efforts to diagnose and evaluate water pipes are limited to the assessment of current pipe conditions, which is why they can easily determine the priority of rehabilitation based on the current pipe conditions but have hard time getting information about how the pipes have deteriorated to the point of requiring rehabilitation. The objectives of this study are: (1) develop a model for estimating corrosion rates and residual thickness of water pipes, (2) assess loads and stress affecting water pipes, (3) to estimate damage risk, and (4) calculate safety factors. Results of the study could help reduce rehabilitation costs and secure water quality after renovation. Thus it would contribute to the safe and stable operation and management of pipe networks by increasing the life of water pipes.

Matrix acidizing is used in carbonate formations to create wormholes that connect the formation to the wellbore. Hydrochloric acid, organic acids, or mixtures of these acids are typically used in matrix acidizing treatments of carbonate reservoirs. However, the use of these acids in deep wells has some major drawbacks including high and uncontrolled reaction rate and corrosion to well tubulars, especially those made of chrome-based tubulars (Cr-13 and duplex steel), and these problems become severe at high temperatures. Hydrochloric acid (HCl) and its based fluids have a major drawback in stimulating shallow (low fracture gradient) formations as they may cause face dissolution (formation surface washout) if injected at low rates. The objective of stimulation of sandstone reservoirs is to remove the damage caused to the production zone during drilling or completion operations. Many problems may occur during sandstone acidizing with Hydrochloric/Hydrofluoric acids (HCl/HF) mud acid. Among those problems: decomposition of clays in HCl acids, precipitation of fluosilicates, the presence of carbonate can cause the precipitation of calcium fluorides, silica-gel filming, colloidal silica-gel precipitation, and mixing between various stages of the treatment. To overcome problems associated with strong acids, chelating agents were introduced and used in the field. However, major concerns with most of these chemicals are their limited dissolving power and negative environmental impact. Glutamic acid diacetic acid (GLDA) a newly developed environmentally friendly chelate was examined as stand-alone stimulation fluid in deep oil and gas wells. In this study we used GLDA to stimulate carbonate cores (calcite and dolomite). GLDA was also used to stimulate and remove the damage from different sandstone cores containing different compositions of clay minerals. Carbonate cores (calcite and dolomite) of 6 and 20 in. length and 1.5 in. diameter were used in the coreflood experiments. Coreflood experiments were run at temperatures ranging from 180 to 300oF. Ethylene diamine tetra acetic acid (EDTA), hydroxyl ethylethylene diaminetriacetic acid (HEDTA), and GLDA were used to stimulate and remove the damage from different sandstone cores at high temperatures. X-ray Computed Topography (CT) scans were used to determine the effectiveness of these fluids in stimulation calcite and dolomite cores and removing the damage from sandstone cores. The sandstone cores used in this study contain from 1 to 18 wt percent illite (swellable and migratable clay mineral). GLDA was found to be highly effective in creating wormholes over a wide range of pH (1.7-13) in calcite cores. Increasing temperature enhanced the reaction rate, more calcite was dissolved, and larger wormholes were formed for different pH with smaller volumes of GLDA solutions. GLDA has a prolonged activity and leads to a decreased surface spending resulting in face dissolution and therefore acts deeper in the formation. In addition, GLDA was very effective in creating wormholes in the dolomite core as it is a good chelate for magnesium. Coreflood experiments showed that at high pH values (pH =11) GLDA, HEDTA, and EDTA were almost the same in increasing the permeability of both Berea and Bandera sandstone cores. GLDA, HEDTA, and EDTA were compatible with Bandera sandstone cores which contains 10 wt percent Illite. The weight loss from the core was highest in case of HEDTA and lowest in case of GLDA at pH 11. At low pH values (pH =4) 0.6M GLDA performed better than 0.6M HEDTA in the coreflood experiments. The permeability ratio (final/initial) for Bandera sandstone cores was 2 in the case of GLDA and 1.2 in the case of HEDTA at pH of 4 and 300oF. At high pH HEDTA was the best chelating agent to stimulate different sandstone cores, and at low pH GLDA was the best one. For Berea sandstone cores EDTA at high pH of 11 was the best in increasing the permeability of the core at 300oF. The low pH GLDA based fluid has been especially designed for high temperature oil well stimulation in carbonate and sandstone rock. Extensive studies have proved that GLDA effectively created wormholes in carbonate cores, is gentle to most types of casing including Cr-based tubular, has a high thermal stability and gives no unwanted interactions with carbonate or sandstone formations. These unique properties ensure that it can be safely used under extreme conditions for which the current technologies do not give optimal results. Furthermore, this stimulation fluid contributes to a sustainable future as it based on readily biodegradable GLDA that is made from natural and renewable raw material.

Aluminum bond pads on semiconductor chips play an important role in IC device reliability and yield. In the paper, the vertical tension loading transferred from the capillary is clarified as the direct driving force for bond pad metal peeling. The crack on the bonding pad is identified as the root cause of the pad peeling. It is simulated by finite element method to find the effect of driving force resulting in the crack during the ultrasonic wire bonding process. It indicated that the horizontal vibration of the capillary controlled by ultrasonic power of the bonding machine was the main factors led to the crack on the bonding pad as well as its propagation into the oxide layers in chip. The degradation of Au wire/Al bond pad has become a major bonding failure problem. It is because that the molding resin with low thermal stability (e.g. bi-phenyl epoxy resin) and the IC devices under high thermal environments were used in packaging process. For the lifetime to bond failure, the bi-phenyl epoxy molding becomes shorter than that for cresol novolac epoxy due to the corrosion reaction of Au-Al intermetallics with bromine (Br) contained in the resin compounds. It was clarified that the reactive intermetallic was Au4Al phase formed in the bond interface. In addition, by utilizing the SEM, AES, EDS and XPS techniques, it could be carried out to reveal and identify defects underneath Al layer, and the contaminated Al bond pads could cause poor intermetallic growths led to the failed or unreliable connections from the chip to the outside world.

<p>In view of the excellent mechanical, chemical and opticalproperties, AlON (Aluminum oxynitride) as well as MgAlON(Magnesium Aluminum oxynitride) have drawn the attention ofmaterials scientists in past decades. In this thesis,thermodynamic properties, synthesis and corrosion resistance tooxygen and slag of AlON and MgAlON ceramics have beeninvestigated.</p><p>Gibbs energy of AlON and MgAlON with different compositionsand temperatures were estimatedby using thermodynamicquasi-parabola rule. Phase stability diagrams of Al-O-N andMg-Al-O-N systems at different conditions have been calculated.On the basis of thermodynamic analysis, AlON and MgAlONceramics were synthesized by hot-press sintering andcharacterized by XRD, TEM and HREM analyses. An X-raydiffraction standard file of MgAlON is suggested and sent toJCPDS.</p><p>The density of AlON synthesized was 3.63g/cm³, about 97.8% of its theoretical density. Thedensity of MgAlON is 3.55 g/cm³. Fracture toughness of AlON and MgAlON is 3.96 and4.06 MPa.m^1/2. Three-point bending strength of AlON and MgAlONare 248 and 268 MPa, respectively, at room temperature andkeeps very high until 1723K. However the strength drops 189 and202 MPa for AlON and MgAlON, respectively, at 1723K. Thefracture section of AlON and MgAlON were examined and found tobe a mixed fracture of intercrystalline and cleavage fracturefor AlON and a mixed intercrystalline and transcrystallinefracture for MgAlON.</p><p>Oxidation experiments of AlON and MgAlON and a comparison ofthe oxidation behavior of AlON, MgAlON, O'SiAlON-ZrO₂and NB-ZCM have been carried out. Undernon-isothermal oxidation conditions, oxidation of AlON exhibitstwo steps with a "S"-shaped curve due to the phasetransformation of oxidation product. As temperature increases,the oxidation product, γ -Al₂O₃formed at lower temperatures will transform intoα-Al₂O₃. Due to the differences in the molar volumesbetween α-Al₂O₃and γ -Al₂O₃, cracks are likely to be formed in the productlayer promoting further oxidation. MgAlON, O'SiAlON-ZrO₂and NB-ZCM show only one step with paraboliccurves.</p><p>Isothermal oxidation experiments of AlON, MgAlON,O'SiAlON-ZrO₂and NB-ZCM have been carried out in thetemperature range of 1373-1773K. At lower temperatures, MgAlONshows the best resistance to oxidation. But at highertemperatures, such as 1773K, AlON shows the best resistance tooxidation. O'SiAlON-ZrO₂shows very good oxidation resistance in the lowtemperature range up to 1673K. But, as the temperature goes upabove 1673K, there is liquid phase produced during theoxidation process. Gas bubbles are also formed in the productlayer causing the flaking-off of some parts of the productlayer. Therefore its oxidation rate increases greatly astemperature rises to 1673K. In the case of BN-ZCM ceramics, dueto the evaporation of B₂O₃, the oxidation resistance seems to be poorest. Thechemical reaction activation energies for the initial stage ofoxidation of AlON, MgAlON, O'SiAlON-ZrO₂and BN-ZCM are 218, 330, 260 and 254 kJ/molerespectively. And the activation energies at the laterdiffusion controlling stages are 227, 573, 367 and 289 kJ/molefor AlON, MgAlON, O'SiAlON-ZrO₂and BN-ZCM respectively.</p><p>The roughness of the oxidation sample surfaces has beenmeasured by Atomic Force Microscope. As the temperatureincreases, the degrees of roughness of AlON and MgAlON surfacesincrease slightly due to the growth of crystal grain. Theroughness degree of BN-ZCM increases greatly because of theevaporation of B₂O₃. However the roughness of O'SiAlON-ZrO₂decreases as the temperature increases from 1473Kto 1673K. The main reason is that the liquid phase (glass)produced during the oxidation process at high temperatures suchas 1673K and 1773K. The roughness degree of MgAlON, AlON,O'SiAlON-ZrO₂and BN-ZCM are 234, 174, 75 and 63 nm respectivelyat 1473K, and 297, 284, 52 and 406 nm respectively at1673K.</p><p>Experiments of corrosion of AlON by CaO-MgO-"FeO"-Al₂O₃-SiO₂slags were conducted in the temperature range of1693-1753K under static conditions as well as under forcedconvection. XRD, SEM-EDS and TEM analyses on the corrodedsamples were carried out.</p><p>The results showed that the diffusion was therate-controlling step in the initial stage of the corrosion.Thereafter, the slag formation (the product layer dissolvinginto the liquid slag) became more and more important. Thisaspect was further confirmed by fractal dimension analysis ofthe interface. The overall activation energy for the corrosionprocess with slag No.1 was evaluated to be 1002 kJ. Adding"FeO" to the slag greatly enhanced the corrosion rate probablydue to the reaction of the sample with "FeO".</p><p><b>Key words:</b>AlON, MgAlON, Thermodynamics, Synthesis,Oxidation, Slag corrosion</p>

Thesis (Ph. D.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 228-234).

Thèse doctorat : Génie des Matériaux : Villeurbanne, INSA : 2003. / Titre provenant de l'écran-titre. Bibliogr. p. 223-237.

Thèse doctorat : Génie des Matériaux : INSA LYON : 2002. / Titre provenant de l'écran-titre. Bibliogr. p. 167-178.

Thèse de doctorat : sciences. Matériaux : Ecully, Ecole centrale de Lyon : 2004. / 137 réf.

Thèse de doctorat : sciences. Matériaux : Ecully, Ecole centrale de Lyon : 2004. / Titre provenant de l'écran-titre. 137 réf.

Thèse doctorat : Génie des Matériaux : Villeurbanne, INSA : 2000. / Titre provenant de l'écran-titre. Bibliogr. p. 173-176.