No description available.

Zugl.: Clausthal, Techn. Univ., Habil.-Schr., 2008

Thesis (M.S.)--Ohio University, June, 1990. / Title from PDF t.p.

Thesis (M.S. in Electrical Engineering)--Washington State University. / Includes bibliographical references.

Thesis (Ph. D.)--Washington State University, May 2006. / Includes bibliographical references (p. 94-96).

High fuel prices have created an economic climate in which oil and gas development is increasingly profitable, and consequently, is increasing rapidly in the United States. The development includes drilling new wells and expanding the pipeline network to deliver gas and oil. This is especially true in the northern Appalachian region where the relatively undeveloped Marcellus shale formation is located. The Marcellus formation has been called a "super giant" gas reservoir possibly containing 50 trillion cubic feet of recoverable natural gas (Harper, 2008). In Pennsylvania alone, over 375 wells targeting the Marcellus shale formation have been approved between 2003 and the end of 2007. However, environmental impacts from well pads and pipelines are relatively unknown. Sediment concentrations and yields were measured from four sections of an in-road pipeline in the Monongahela National Forest in Tucker County, West Virginia during summer and fall 2007 and spring 2008. The objectives of this study were to determine the influence of vegetation cover and precipitation characteristics on sediment concentrations in runoff and sediment yields from the in-road pipeline, and to compare sediment yields to forest roads. Poorly vegetated pipeline sections produced 30.92 kg of sediment throughout the study compared to 13.49 kg for the well vegetated sections. Despite this, percent vegetative ground cover had no statistically significantly effect on sediment concentrations or yields except during very intense storms. Several precipitation characteristics, especially intensity, played a significant role in explaining sediment yields and concentrations. Precipitation patterns changed with seasons, and therefore, sediment concentrations and yields varied significantly by season. The most intense storms occurred during the summer months, which is when most soil loss also occurred. Erosion rates from the pipeline were greater than from undisturbed or well-managed forest plots, but were less than rates reported for logging and skid roads when normalized for rainfall. The reduced erosion rates suggest that routing new pipelines along closed roads may be a good method to reduce erosion compared to clearing new pipeline rights-of-ways. To further reduce erosion potential, steps in the installation process that expose mineral soil should be timed to avoid periods of intense rainfall.

Made available in DSpace on 2014-06-11T19:22:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-03-03Bitstream added on 2014-06-13T18:49:39Z : No. of bitstreams: 1 martins_cp_me_ilha.pdf: 1858645 bytes, checksum: d00de31c1c7eea4b71e680fd0b1f93ff (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O projeto de sistemas digitais é, na maioria das vezes, uma tarefa complexa e que consome muito tempo do projetista. Não se concebe atualmente que esses projetos sejam inteiramente realizados sem que os sistemas projetados sejam modelados e simulados, procurando diminuir o custo de projeto. Entre as técnicas em uso para a geração de modelos estão as baseadas em redes de Petri. O problema com redes de Petri é que existe uma grande variedade de diferentes técnicas para modelar sistemas equivalentes e, além disso, o tratamento de tempo é feito de formas muito distintas. Nesse trabalho se apresentam algumas técnicas de redes de Petri que permitem o tratamento de tempo e se faz a comparação entre as mesmas quando aplicadas na modelagem de um pipeline. Dentre as técnicas examinadas está incluída uma rede híbrida, na qual se propõe a mistura não tradicional de outras técnicas mais básicas, buscando melhores resultados do que os obtidos com tais redes. Apresentam-se resultados obtidos com um protótipo de um simulador especialmente projetado para ser capaz de simular as redes de Petri híbridas propostas nesse trabalho, assim como cada uma das técnicas individuais nelas utilizadas. / The design of a digital system often is a complex and time consuming task. Nowadays it is unconceivable that these designs would be entirely done without modeling and simulation, in order to save design costs. Among the modeling techniques in use there are the Petri nets models. The drawback with Petri nets is that there is a wide range of diferent techniques to perform the modeling of equivalent systems and, moreover, the time manipulation is performed through very distinct approaches. Some Petri net techniques that deal with time are presented in this work. Comparisons between these techniques are done through the modeling of a pipeline. Among the techniques examined there is a hybrid one, that is propposed as a composition of the basic techniques, aiming the improvement of the modeling results. Results provided by a prototype of a Petri Net simulator built to simulate the hybrid model, and its component techniques, are presented.

Steel is widely used as building material for large-scale structures, such as oil and gas pipelines, due to its high strength-to-weight ratio. However, corrosion attack has been long recognized as one of the major reasons of steel pipeline degradation and brings great threat to safety in normal operation of structure. To mitigate the corrosion attacks, coatings are generally applied to protect steel pipelines against corrosion and improve durability of the associated structures for longer service life. Although have higher corrosion resistance, coated pipelines will still get corroded in a long run, as coatings may subject to damages such as cracks. Cracks on coatings could lower the effectiveness of protection for associated structures. Timely updates of up-to-date corrosion rate, corrosion location, and coating conditions to the pipeline risk management model and prompt repairs on these damaged coatings would significantly improve the reliability of protected structures against deterioration and failure. In this study, a corrosion risk analysis system is developed to detect and locate the corrosion induced coating cracks on coated steel using embedded fiber Bragg grating (FBG) sensors. The coatings investigated include high velocity oxygen fuel (HVOF) thermal sprayed Al-Bronze coating, wire arc sprayed Al-Zn coating, and soft coating. Theoretical models of corrosion risk assessment system were carried out followed by systematic laboratory experiments, which shows that the developed system can quantitatively detect corrosion rate, corrosion propagations, and accurately locate the cracks initialized in the coating in real time. This real-time corrosion information can be integrated into pipeline risk management model to optimize the corrosion related risk analysis for resource allocation. To place the sensing units of the system in the most needed locations along the huge pipeline systems for an effective corrosion risk assessment, an example case study is conducted in this study to show how to locate the most critical sensor placement locations along the pipeline using worst case oil and gas discharge analysis. Further applications of the developed system can be integrated with pipeline management system for better maintenance resource allocations. / USDOT-PHMSA

Motivation: In the last years more than 20 vertebrate genomes have been sequenced, and the rate at which genomic DNA information becomes available is rapidly accelerating. Gene duplication and gene loss events inherently limit the accuracy of orthology detection based on sequence similarity alone. Fully automated methods for orthology annotation do exist but often fail to identify individual members in cases of large gene families, or to distinguish missing data from traceable gene losses. This situation can be improved in many cases by including conserved synteny information. Results: Here we present the SynBlast pipeline that is designed to construct and evaluate local synteny information. SynBlast uses the genomic region around a focal reference gene to retrieve candidates for homologous regions from a collection of target genomes and ranks them in accord with the available evidence for homology. The pipeline is intended as a tool to aid high quality manual annotation in particular in those cases where automatic procedures fail. We demonstrate how SynBlast is applied to retrieving orthologous and paralogous clusters using the vertebrate Hox and ParaHox clusters as examples.

Yes / Seabed instability around a pipeline is one of the primary concerns in offshore pipeline projects. To date, most studies focus on investigating the wave/current-induced response within a porous seabed around either a fully buried pipeline or a thoroughly exposed one. In this study, unlike previous investigations, a series of comprehensive laboratory experiments are carried out in a wave flume to investigate the wave-induced pore pressures around a partially embedded pipeline in a trench layer. Measurements show that the presence of the partially buried pipeline can significantly affect the excess pore pressure in a partially backfilled trench layer, which deviates considerably from that predicted by the theoretical approach. The morphology of the trench layer accompanied with the backfill sediments, especially the deeper trench and thicker backfill (i.e.,b≥1D,e≥0.5D), provides a certain degree of resistance to seabed instability. The amplitude of excess pore pressure around the trench layer roughly exhibits a left-right asymmetric distribution along the periphery of the pipeline, and decays sharply from the upper layer of the trench to the lower region. Deeper trench depth and thicker buried layer significantly weaken the pore-water pressures in the whole trench area, thus sheltering and protecting the submarine pipeline against the transient seabed liquefaction. / The National Key research and development program of China (2017YFC1404200), the research grants of Jiangsu (BK20150804), the marine renewable energy research project of State Oceanic Administration (GHME2015GC01), Open Foundation of State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University (Project No: 2016491011), the Royal Academy of Engineering the Distinguished Visiting Fellowship (DVF1718-8-7)