Dissertations / Theses on the topic 'LONI Pipeline'

The objective of this thesis is to improve flow modeling through offshore natural gas pipelines. Gassco is a state owned Norwegian company responsible for the operation of 7800 km offshore natural gas pipelines located in the North Sea. The pipelines have a diameter of 1 m and can be up to 1000 km in length. Measurements of the state of the gas, such as pressure, mass flow, temperature and composition are available only at the inlet and outlet. To know the state of the gas between these two points one has to rely on computer models. Gassco uses commercial tools to model the flow of gas through their pipelines. These have previously given inaccurate results, especially during transient conditions. The flow of natural gas through long distance offshore pipelines is modeled by numerically solving the governing equations for one-dimensional compressible viscous heat conducting flow. An implicit finite difference scheme is used to solve the governing equations. Both spatial and temporal discretization errors are computed. The implemented flow model is validated by running simulations on one of Gassco’s offshore pipelines. Modeled results show good agreement with measured values, however some discrepancies are present, especially in the modeled outlet gas temperature. These discrepancies are determined to be caused by physical approximation errors, and not because of numerical errors or model simplifications. The sensitivity of the selection of the equation of state for high pressure natural gas pipelines is investigated by comparing the SRK, Peng-Robinson, BWRS, GERG 88 and GERG 2004 equations of state. Gassco currently uses a BWRS equation of state which is especially tuned for hydrocarbons. In a typical offshore natural gas pipeline, the difference in computed inlet pressure between using the tuned BWRS and the GERG 2004 equation of state was determined to be approximately 0.1 MPa (1 bar). Although GERG 2004 is believed to be the most accurate equation of state, it is computationally demanding compared to BWRS, resulting in BWRS being the preferred choice. Although there is a difference in computed inlet pressure between GERG 2004 and BWRS, this difference is relatively constant during both steady state and transient conditions. By tuning the equivalent sand grain roughness, the computed inlet pressure using both GERG 2004 and BWRS can be matched in order to compensate for differences in the equation of state. The heat exchange between the gas and the surrounding environment is modeled using two different approaches. The steady external heat transfer model currently used by Gassco is compared to an unsteady external heat transfer model which includes heat accumulation in the ground. It is shown by example that the steady heat transfer model over predicts the amplitude of temperature changes in the flow compared to the unsteady heat transfer model. The unsteady heat transfer model also improves the modeled inlet pressure and outlet mass flow during transient conditions. Although the modeled temperature is improved using the unsteady heat transfer model, there is still a discrepancy between modeled and measured outlet gas temperature. The most important parameters which can account for this deviation are the ambient sea bottom temperature, soil thermal conductivity and pipe burial length.

This thesis presents results from a systematic study undertaken to establish the influence of sulphur dioxide (SO2 and O2) content on the critical water content required to initiate substantial levels of internal corrosion during the transport of supercritical CO2 for Carbon Capture and Storage (CCS) applications. An assessment of both the general and localised corrosion behaviour of X65 carbon steel in water-containing CO2 environments is presented. Firstly, autoclave experiments were conducted in environments where the CO2 phase was either saturated or under-saturated with water. Such an approach enabled identification of the minimum water content in the system, below which no general or localised attack was observed. Later, corrosion experiments were performed containing supercritical CO2 and the presence of 0, 50 and 100 ppm SO2 with a low level of O2 (20 ppm). The results highlights that reducing water content is a more favourable option compared to reducing SO2 content to minimise corrosion in the system as high corrosion rates can be observed in the absence of SO2 if water content is high enough, but below a minimum water content (~500 ppm), both general and localised corrosion is minimal despite the presence of 100 ppm SO2. Analysis of corrosion products formed on the steel surface is performed using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray spectroscopy (EDX), Transmission Electron Microscopy (TEM), Raman spectroscopy. Only FeCO3 was detected on the surface without SO2 and O2, whilst both FeCO3 and FeSO3.3H2O were identified on the surface of the carbon steel samples exposed to the environments containing 2 and 100 ppm SO2 and 20 ppm O2. The localised corrosion rates were determined by surface profilometry measurement. The most important observation from this work is that the key degradation mechanism in all experiments was localised corrosion. Not only was the combination of SO2 and O2 shown to influence pitting severity, but the pitting rates recorded were nearly one order of magnitude greater than the uniform corrosion rate determined from mass loss measurements. The increase in SO2 content was shown to influence the shape of pits as well as their overall depth. In particular, the work highlights the importance of adopting a systematic approach when determining pitting behaviour of carbon steels exposed to impure dense-phase CO2.

Long intergenic non-coding RNAs (lincRNAs) are an abundant and functionally diverse class of eukaryotic transcripts. Reported lincRNA repertoires in mammals vary, but are commonly in the thousands to tens of thousands of transcripts, covering similar to 90% of the genome. In addition to elucidating function, there is particular interest in understanding the origin and evolution of lincRNAs. Aside from mammals, lincRNA populations have been sparsely sampled, precluding evolutionary analyses focused on their emergence and persistence. Here we present Evolinc, a two-module pipeline designed to facilitate lincRNA discovery and characterize aspects of lincRNA evolution. The first module (Evolinc-I) is a lincRNA identification workflow that also facilitates downstream differential expression analysis and genome browser visualization of identified lincRNAs. The second module (Evolinc-II) is a genomic and transcriptomic comparative analysis workflow that determines the phylogenetic depth to which a lincRNA locus is conserved within a user-defined group of related species. Here we validate lincRNA catalogs generated with Evolinc-I against previously annotated Arabidopsis and human lincRNA data. Evolinc-I recapitulated earlier findings and uncovered an additional 70 Arabidopsis and 43 human lincRNAs. We demonstrate the usefulness of Evolinc-II by examining the evolutionary histories of a public dataset of 5,361 Arabidopsis lincRNAs. We used Evolinc-II to winnow this dataset to 40 lincRNAs conserved across species in Brassicaceae. Finally, we show how Evolinc-II can be used to recover the evolutionary history of a known lincRNA, the human telomerase RNA (TERC). These latter analyses revealed unexpected duplication events as well as the loss and subsequent acquisition of a novel TERC locus in the lineage leading to mice and rats. The Evolinc pipeline is currently integrated in CyVerse's Discovery Environment and is free for use by researchers.

PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO<br>A redução de espessura de parede causada por corrosão é um dos defeitos que mais afetam a integridade dos dutos. Estes defeitos podem ocorrer no metal base, nas soldas longitudinais ou circunferenciais, bem como nas zonas afetadas pelo calor. Os métodos de avaliação da resistência remanescente introduzem ressalvas ou proíbem o tratamento de defeitos de corrosão coincidentes com as juntas soldadas. No presente trabalho foram avaliados os níveis de segurança dos métodos usuais de avaliação da resistência de dutos com defeitos introduzidos na região da solda longitudinal de tubos soldados por arco submerso. Os tubos testados eram de aço C-Mn fabricados na década de 60 e foram retirados de operação após uma campanha superior a 30 anos. Com estes tubos foram fabricados 5 espécimes, cada qual com 1 defeito externo produzido por eletro-erosão, sendo posteriormente submetidos a testes de pressão monitorados. Foram realizados ensaios de tração, ensaios de impacto Charpy e ensaios de dobramento, para determinação das propriedades mecânicas do metal de base, do metal de solda e da zona termicamente afetada (ZTA). Foram realizados também ensaios metalográficos do metal de base e do metal de solda, análise química do metal de base e do metal de solda e medição das tensões residuais no metal de solda. A aplicação dos métodos de nível 1 (ASME B31G, 085dL, RPA, DNV isolado e PCORRC) resultou em pressões previstas inferiores às pressões reais de ruptura para defeitos de formato esférico. Para defeitos de seção retangular a aplicação dos métodos de nível 1 resultou em pressões superiores às pressões reais. A aplicação dos métodos de nível 2 (Effective Area e DNV geometria complexa) resultou em pressões previstas superiores às pressões reais de ruptura para defeitos de formato esférico e de seção retangular. As análises das fraturas indicaram que não ocorreu falha por deficiência de tenacidade em nenhum espécime. A corrosão alveolar leve pré-existente na superfície interna dos espécimes foi apontada como causa mais provável das pressões previstas superiores às pressões reais de ruptura.<br>One of the most important issues that affects pipeline integrity is corrosion-caused metal loss. This type of defect can occur over the pipe body, seam or girth welds or even on heat affected zones. Pipeline remaining strength criterions are restricted or even prohibited for assessing corrosion defects coincident with weld regions. This present work investigated the reliability of the most common assessment criteria for corroded pipes when defects were coincident with seam weld region in submerged arc welded pipes. The tested specimens were C-Mn steel pipe, from a pipeline manufactured in the 60´s and had operated for over 30 years. Five external defects were created on five pipe specimens and pressure tested until rupture. Stress, charpy V-notch and bending tests were carried out to find the mechanical properties of the welded joints. Microstructure and chemical composition from base metal and weld metal were also analyzed. Residual stresses on welds were measured. The level 1 criterion (ASME B31G, 085dL, RPA, DNV single and PCORRC) applications have underestimated failure pressure for spherical shaped defects. On the other hand, the same criterions have overestimated failure pressure for rectangular shaped defects. The level 2 criterions (Effective Area e DNV complex geometry) application overestimated failure pressure for all 5 specimens with both spherical and rectangular shaped defects. Fracture analyses have indicated that no specimen had a toughness controlled failure. Internal pit corrosion that was found after pressure testing is recognized as the most probable cause of underestimated pressure forecasts.

<p> The workforce gap remains for women and underrepresented minorities in science technology, engineering, and mathematics careers. There are several program initiatives to help address this gap especially long-term STEM enrichment programs. There is a vast amount of literature on STEM enrichment programs, but limited information on the long-term impacts. The purpose of this qualitative, phenomenological study was to understand the experiences of young women and URMS who participated in long-term STEM enrichment programs and the impact those programs had on their STEM path. The 11 adult female participants were at various stages of their STEM journey from entering college to STEM careers. The phenomenological approach was used to gain a rich contextual understanding of their lived experiences. This study was framed through Bronfenbrenner&rsquo;s (2005) bioecological model by identifying the macro- and microsystems of the participants&rsquo; experiences and then exploring the impact of those systems. Through the qualitative analysis 10 themes emerged that represent the participants&rsquo; experiences: (1) STEM enrichment programs and staff created a place where participants felt welcomed and valued; (2) STEM enrichment programs challenged and supported participants to move outside their comfort zones; (3) STEM enrichment programs provided opportunities for both cognitive and non-cognitive skills development; (4) Family involvement of STEM enrichment programs ranged from low to high engagement (5) Participants experienced non-supportive educators along their journey while STEM enrichment programs countered those experiences; (6) Participants reflected that K-12 early exposure to STEM is critical for a STEM career path; (7) STEM enrichment program involvement provided both short-term and long-term benefits; (8) STEM enrichment programs&rsquo; role models and mentors were seen as heroes and provided inspiration, which created a pipeline of giving back; (9) Participants did not seek out STEM programs but pursued STEM involvement because of external encouragement; (10) Issues related to gender and race still prevalent, but STEM enrichment programs provided support and confidence for participants in non-diverse settings. Implications, recommendations, and suggestions for future research are also presented.</p><p>

This report presents a stochastic method for predicting scour depth around vertical circular slender piles, including various cross sections and group arrangements, marine pipelines and the burial and scour hole geometry around short cylinders due to long-crested (3D) and shortcrested (2D) nonlinear random waves plus current. The waves are assumed to be stationary narrowbanded and the Forristall (2000) distribution of wave crest heights representing 2D and 3D random waves is employed including both sum-frequency and difference-frequency effects. The wave crests are assumed to be responsible for the scour response. The results for scour and burial around the various structure types are presented graphically versus a measure of the wave action evaluated at the seabed relative to the characteristic diameter of the structure and versus a measure of the current velocity relative to the maximum horizontal fluid particle velocity at the seabed. The ratios between the scour depth predicted by 3D, 2D and linear waves are also investigated. Examples of calculation based on typical field conditions are provided. Due to the distinctive character of the Forristall distribution, all the results are specifically given by the seastate and the characteristic structure diameter. There are several similarities in the ratios of the scour depth for the various structures. Overall, 3D and 2D waves will produce more scour and burial than linear waves. This is due to higher fluid particla velocity under the wave crests for 3D and 2D waves compared to linear waves. In deep water, the scour depth from 2D waves is largest and in finite water depth the scour depth from 3D waves is largest. This is due to larger sum-frequency effects for 2D waves compared to 3D waves in deep water and smaller difference-frequency effects for 3D waves compared to 2D waves in finite water depth.

碩士<br>國立臺北科技大學<br>機電整合研究所<br>104<br>The most reliable and efficient long-distance pipeline transportation is gas and oil. Due to the prolonged use and the environmental impact of the pipeline, many old underground pipe line is not listed and neglect of maintenance, leading public dangers incident to transportation security issues. The aim of this study is to records and locate the path of the pipeline and the development path records and inspection of pipelines under normal transmission of the pipeline. It will help old underground pipeline maintenance in the future.This study focuses on an automated line positioning systems, including machine vehicles, hardware integration and data analysis pipeline route survey and mapping.This study for the domestic transport of underground oil 4 inch, 6 inch, 10 inch, 12 inch diameter design. Vehicle use it own transport medium pressure pipelines for moving, vehicle body parts produced by a 3D printer. Hardware system using the Arduino Nano with MPU6050 six-axis inertial sensor to consolidate, and the numerical analysis is using mathematical software MATLAB to do numerical analysis.The results of this experimental study for established a three dimensional of route simulation figure, In the experiment of two-dimensional 90 degree bend tube, its total length is 260.5 cm . We measure the average displacement of 260.82 cm, average error is 6.1%, In experiment of three-dimensional 90 degree s and 45 degrees bent tube, its total length is 570 cm. We measure the average displacement of 557.84 cm, average error is 6.8%,vehicle in the pipeline movement speed is 9.5 cm/s . We hope such technology can be applied in the future to find out more of old pipelines buried underground. As a result, we can check and maintain more easily

碩士<br>國立臺北科技大學<br>機電整合研究所<br>105<br>This study establish an intelligent underground pipeline inspection system and the purpose is to use motor drive force and media transmission force in the pipeline to support the carrier movement and we use MATLAB to analyze data about magnetic flux and map pipe diameter route in the 4-inch pipeline for research. In this study, the main principle is to detect magnetic leakage and draw the defect map. We combine the gyroscope and the acceleration sensor to carry out in the pipeline to know the defect location. Carrier is divided into three parts. The first part is that the positioning system equipped with jy61 chip to record carrier operating path and monitor the system location and posture. The second part is that the driving system equipped with micro-motor and battery so that we can control the carrier to move and use the encoder to record walking distance. The third part is that the detection system is equipped with six Hall sensor and servo motor to achieve cyclic inspection and recording in the tube within 180 °. The defects detected in this experiment were blind hole with 2mm,4mm, 6mm,8mm, depth with 2mm, 4mm,6mm.

This dissertation demonstrates how the cross-disciplinary application of methods and tools from archaeology, philology, and engineering can yield insights into ancient water-supply systems and help to solve problems associated with their precise function and with their description in ancient literature. Conventional calculations determine the flow properties of seven ancient long-distance pipelines. Components of the water-supply pipeline at Aspendos are simulated with a commercially available Computational Fluid Dynamics (CFD) software package (FLUENT® by Fluent Inc.) that is widely used in the design and research of complex flow systems. The application of CFD clarifies the interaction of water and air during the filling process of a pipeline. The project establishes a methodology using state-of-the-art computer simulation tools for the investigation of these systems. The combination of the numerical results with the insights derived from a comparison of Latin technical documents with ancient Greek medical texts answers conclusively some long-term questions that have been plaguing aqueduct research for a long time. The simulation makes visible the flow of water in the pipeline, disproving the long-term misunderstanding that entrained air will form bubbles in the flowing water column that lead to pressure transient. It is possible to explain the function of lateral holes in the sides of pipe segments. The calculated volume flow rates for each pipeline allow estimates about the population sizes for the cities supplies by the aqueducts. The creation of a computer-based methodology for the study of ancient aqueducts will enable scholars to investigate, compare, and catalogue a wide variety of ancient hydraulic systems.

碩士<br>國立交通大學<br>電子研究所<br>107<br>Compared with traditional DNA sequencing technologies, Third generation sequencing(TGS) such as Oxford Nanopore can generate relatively long reads within a short amount of time using a portable device. However, these reads generated often have a high error rate which ranges from 15\% to 35\%. Among the existing popular alignment algorithms, only very few are designed to handle long reads with such a high error rate. The speed of these algorithms also tends to be slower, suggesting their efficiency could be further improved. We modify the COSINE algorithm in and effectively accelerate its overall computation by taking advantage of the power of Nvidia GPGPU, optimizing data sharing, and managing the pipeline between CPU and GPGPU. As a result, we provide a fast DNA sequence alignment framework that supports various input formats including FASTQ, FASTA, SAM, with both single-end and pair-end reads. Compared with the original COSINE algorithm, we achieve a higher throughput rate of 1.5 to 5.5 times faster, while maintaining its accuracy.