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The ability of a filter to stop erosion through cracks in the core of a embankment dam requires that the filter be graded so that it will restrain movement of particles from the core, and that the filter be truly cohesionless, so that it will not crack even when subjected to the same types of deformations that cause cracks in the core. To achieve resistance to cracking, most current filter criteria require that the filter should contain no more than 5% of material finer than the #200 sieve, and that this fine material should be non-plastic. This research study was conducted to investigate whether there specifications do, in fact, result in filters that can be relied upon to slump, fill cracks, and prevent interval erosion in embankment dams. The research study involved filter erosion tests using a 4-inch diameter device and a 12-inch square device, and "sand castle" tests to investigate the tendency for candidate filters to slump when immersed in water. These tests showed that conventional filter criteria  no more than 5% fines, and fines that are non-plastic, are conservative. The research study showed that even filters with 5% of highly plastic fines are able to slump, fill cracks, and prevent erosion. / Ph. D.

The Great Plains piping plover (Charadrius melodus) population was listed as threatened under the Endangered Species Act in 1986. The challenge for managers of this population is to increase the fledging rate and to ensure that there is sufficient habitat to support an increasing population. According to the revised recovery plan, there are insufficient quantitative data that relate habitat characteristics to reproductive success in riverine habitat. In particular, additional data are needed to determine if piping plover reproduction is limited by food abundance at breeding sites. The goal of this research was to determine whether piping plover chick survival was limited by foraging site quality on the Missouri River. Productivity has historically varied among river reaches. The alkali wetlands, reported to be very productive, serve as an index to the upper limit of reproductive potential. We compared indices of foraging site quality, chick growth and survival among a reservoir, two river reaches and alkali wetland sites from 2001-2003. We compared piping plover use of protected shoreline and exposed shoreline to availability along two reaches of the Missouri River (Gavins and Garrison). We also examined piping plover chick diet. Chick weight gains were higher at alkali wetlands than Gavins and Garrison. Invertebrate numbers were higher at the alkali wetlands than the three river sites and lowest downstream of the cold water release dam. Invertebrate biomass was highest at the alkali wetlands and downstream of the warm water release dam and lowest downstream of the cold water release dam. Invertebrate biomass downstream of the cold water release dam was the lowest of all 4 sites. There was no relationship between chick daily survival rates and invertebrate biomass or predator presence. Although Diptera occurred more frequently (23% - 64%) at all sites (sticky traps), Coleoptera occurred most frequently in the fecal samples (fecal analysis; 69% to 89%). On the Missouri River, protected shorelines were important foraging sites for piping plovers during the breeding season. We also found that sandbars with low-lying moist habitat are important to foraging chicks. Results are consistent with the prediction that foraging conditions downriver from cold water release dams are inferior to conditions in other habitats in the region. Differences in prey availability are reflected in chick growth rates, but not in survival rates. These results underscore the variability in different indices of habitat quality (invertebrate indices, predation, growth rates, survival rates) among the four sites, and the need for monitoring and management strategies that address each site individually. When managing or creating sandbars, ensuring the availability of protected shoreline will benefit piping plovers on the Missouri River. / Ph. D.

Energy due to fluid-borne and structure-borne disturbances propagating in a fluid-filled pipe will be carried by the structure and the fluid. Energy transfer may occur between these two media due to the coupling between the structure and the fluid. It's not clear when the excitation is fluid-borne or structure-borne, due to the complexity in piping installation designs and the strong coupling between the fluid and shell walls. It is necessary to devise control approaches that tackle both components of the excitation simultaneously. This study will demonstrate new approaches in active and passive control techniques and show their advantages over classical control approaches. It is necessary to understand the physical behavior of fluid-filled pipes, in order to develop a viable control methodology. The equations of motion for the shell and the fluid are needed to characterize the system. These combined with the dispersion equations can then be used to derive analytical expressions for energy flow in the system. The research is limited to lower order wave types. Hence, the expressions for energy flow are derived only for the n=0 and n=1 shell waves and n=0 fluid wave. Higher order waves have cut-on frequencies and were not analyzed. Current sensing methodologies are limited to the analysis of wave types separately. A new approach of wave decomposition using multiple sensors is developed and used to characterize discontinuities along the pipe. The effect of discontinuities and correct control methodologies are investigated. A new control methodology is developed and implemented. The natural distribution of energy into different wave types as it encounters discontinuities is used to devise control solutions with non-intrusive inertial actuators. Improvements of 16 dB in shell waves and 12 dB in fluid waves over the correct control approach are experimentally demonstrated. / Master of Science

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In the oil and gas industry, statistical methods have been used for corrosion analysis for various asset systems such as pipelines, storage tanks, and so on. However, few industrial standards and guidelines provide comprehensive stepwise procedures for the usage of statistical approaches for corrosion analysis. For example, the UK HSE (2002) report "Guidelines for the use of statistics for analysis of sample inspection of corrosion" demonstrates how statistical methods can be used to evaluate corrosion samples, but the methods explained in the document are very basic and do not consider risk factors such as pressure, temperature, design, external factors and other factors for the analyses. Furthermore, often the industrial practice that uses linear approximation on localised corrosion such as pitting is considered inappropriate as pitting growth is not uniform. The aim of this research is to develop an approach that models the stochastic behaviour of localised corrosion and demonstrate how the influencing factors can be linked to the corrosion analyses, for predicting the remaining useful life of components in oil and gas plants. This research addresses a challenge in industry practice. Non-destructive testing (NDT) and inspection techniques have improved in recent years making more and more data available to asset operators. However, this means that these data need to be processed to extract meaningful information. Increasing computer power has enabled the use of statistics for such data processing. Statistical software such as R and OpenBUGS is available to users to explore new and pragmatic statistical methods (e.g. regression models and stochastic models) and fully use the available data in the field. In this thesis, we carry out extreme value analysis to determine maximum defect depth of an offshore conductor pipe and simulate the defect depth using geometric Brownian motion in Chapter 2. In Chapter 3, we introduce a Weibull density regression that is based on a gamma transformation proportional hazards model to analyse the corrosion data of piping deadlegs. The density regression model takes multiple influencing factors into account; this model can be used to extrapolate the corrosion density of inaccessible deadlegs with data available from other piping systems. In Chapter 4, we demonstrate how the corrosion prediction models in Chapters 2 and 3 could be used to predict the remaining useful life of these components. Chapter 1 sets the background to the techniques used, and Chapter 5 presents concluding remarks based on the application of the techniques.

This thesis addresses the calibration and testing of the Oak Ridge Institute for Science and Education's (ORISE) Holdup Measurement System 4 (HMS4) for use in quantifying U-235 holdup contained within the Process Gas Piping (PGP) of the K-25 Building. In addition to the calibration and testing performed the feasibility of measuring U-238 as a surrogate for U-235 quantification was conducted. A Performance Testing and Validation Plan (PTVP) was developed for confirming the calibration of the system and collecting test data to qualify the HMS4 system for the intended application (ORISE 2009). Tests performed were in accordance with the PTVP and the results were documented in the Performance Testing and Validation Report (PTVR). In turn, the results have been examined to verify that the HMS4 system functions properly and can be used to reliably measure the residual U-235 in pipes. Measurement parameters such as the Lower Level of Detection (LLD), the Minimum Detectable Activity (MDA), and the Total Measurement Uncertainty (TMU) have been determined and reported. To support decommissioning activities, a rapid reliable radiation detection system is needed to assess the amount of residual U-235 within the PGP of the K-25 Building in Oak Ridge, Tennessee. The HMS4 system has been selected to make the required measurements. Verification measurements are considered necessary to assess the reliability and adequacy of the PGP characterization results to ensure criticality incredibility. The purpose of this document is to evaluate the characteristics of the HMS4 system regarding its applicability for use on the east side of K-25. Additionally, to define the level of confidence that should be associated with each HMS4 measurement.

Many researchers have contributed to the field of international purchasing; but there are no consistent findings to illustrate particular connections within the field. This particular research studies the ways that two Iranian producers of polymer piping systems handle international purchasing in current complex Iranian economic circumstances. By going beyond macroeconomic theories of international trade and using three-factor model of international industrial purchasing this particular study aims to reveal how international industrial purchasing is handled by Iranian producers of polymer piping systems under current Iranian economic and politic circumstances. A case study approach employing face-to-face semi-structured interview method is designed. A set of interview questionnaires was designed to gather empirical qualitative and quantitative data. A narrative analysis was then conducted to lead the discussions and to draw conclusions. The results of the study show that international purchasing in both firms is influenced by internal factors including attitudes and competence as well as external factors including market conditions and regulations. The levels to which the first three mentioned factors influence international purchasing varies between the studied firms; but regulations have similar effects on the ways the studied firms handle international purchasing. Also, the modified three-factor model is perfectly applicable to the studied cases under current circumstances of Iranian economy.

Heat losses are an important problem in domestic hot water circulation systems. Therefore, to reduce these losses becomes an issue of utmost importance both economically and environmentally. Nevertheless, it has not been until recent years when these losses have been studied further. Commonly studies have focused on the heat space system operation or radiator system. This study focuses on heat losses in the domestic hot water circulation through the piping system in a building at a school located in Gävle (Sweden) using non-destructive flow and temperature reading devices. The heat used by the school is provided by the district heating network that feeds several heat exchangers. The heat losses, at the same time, will be compared with simulation and theoretical procedures to corroborate them. The domestic hot water piping system of this study consists on more than 1200 meters of insulated copper pipes with different diameters and different insulation thickness. The system was measured for one week (April 26, 2015 to May 3, 2015) when there are working days and nonworking days. A 5% of the annual district heating consumption in the school was calculated as heat losses in the domestic hot water circulation system in the building studied. Finally, improvements in insulation system and changes in the domestic hot water temperature have been simulated and they demonstrate that savings of up to 35% of the heat losses can be achieved and produce significant energy savings.

No description available.