As new radio telescopes and processing facilities are being built, the amount of data that has to be processed is growing continuously. This poses significant challenges, especially if the real-time processing is required, which is important for surveys looking for poorly understood objects, such as Fast Radio Bursts, where quick detection and localisation can enable rapid follow-up observations at different frequencies. With the data rates increasing all the time, new processing techniques using the newest hardware, such as GPUs, have to be developed. A new pipeline, called PAFINDER, has been developed to process data taken with a phased array feed, which can generate up to 36 beams on the sky, with data rates of 25 GBps per beam. With the majority of work done on GPUs, the pipeline reaches real-time performance when generating filterbank files used for offline processing. The full real-time processing, including single-pulse searches has also been implemented and has been shown to perform well under favourable conditions. The pipeline was successfully used to record and process data containing observations of RRAT J1819-1458 and positions on the sky where 3 FRBs have been observed previously, including the repeating FRB121102. Detailed examination of J1819-1458 single-pulse detections revealed a complex emission environment with pulses coming from three different rotation phase bands and a number of multi-component emissions. No new FRBs and no repeated bursts from FRB121102 have been detected. The GMRT High Resolution Southern Sky survey observes the sky at high galactic latitudes, searching for new pulsars and FRBs. 127 hours of data have been searched for the presence of any new bursts, with the help of new pipeline developed for this survey. No new FRBs have been found, which can be the result of bad RFI pollution, which was not fully removed despite new techniques being developed and combined with the existing solutions to mitigate these negative effects. Using the best estimates on the total amount of data that has been processed correctly, obtained using new single-pulse simulation software, no detections were found to be consistent with the expected rates for standard candle FRBs with a flat or positive spectrum.

Seabed gouging by ice, also known as ice scouring, is a common feature of the Arctic and sub Arctic regions of the planet as well as in Antarctica. It is a phenomenon which occurs when ice moves while in contact with the seabed. Ice gouging is of economical significance due to the probability of disruption of seabed structures such as subsea pipelines. Small scale laboratory tests were conducted at 1g to investigate the scour force produced when a scaled iceberg model scours a test bed in dry and saturated conditions. The tests were conducted for a range of scour depths, scour widths, frontal rake angles and soil conditions to study the performance of a rigid indenter (iceberg keel) scouring a test bed. Furthermore, the tests were also conducted at various speeds to study the rate effect in sand. The effect of the drifting speed on the drag force was found to be important: a sandy seabed scoured by an iceberg with a mean drifting speed of 0.1 m/s can generate scour loads twice as large as the static loads. The methods used currently to predict ice scour loads consider only the static loads under drained conditions and these should be revised. The PIV (Particle Image Velocimetry) technique was utilized to study the sub-gouge deformation and the soil failure mechanism associated with ice gouging. The soil resistance and the sub gouge deformation results obtained in the laboratory were compared with centrifuge investigations (the PRISE and PIRAM programs) in order to examine the viability of extrapolating the results from the model scale to a prototype scale.

A utilização de gás natural tem ganhado espaço na matriz energética brasileira, principalmente dentro do setor industrial. Para um conjunto de segmentos e processos industriais, a utilização de gás natural como energético ou matéria prima envolve significativos ganhos do ponto de visto ambiental, técnico e econômico. A hipótese motivadora deste trabalho está relacionada ao potencial papel de indutor do desenvolvimento regional que a disponibilidade de gás natural possui. Uma vez que a presença de gasodutos exibe um evidente padrão de concentração espacial bem definido, seria natural esperar que as indústrias que levassem em conta a disponibilidade deste energético em sua decisão de localização se tornassem mais concentradas, acompanhando o traçado dos principais gasodutos. Foram definidas duas principais vias de análise: (i) a avaliação do nível de concentração geográfica (ou espacial) da indústria, verificando-se a existência de padrões distintos para a média da indústria e um grupo de setores definidos como heavy users de gás natural (cerâmica, têxtil e química), e (ii) a avaliação e mapeamento das correlações espaciais entre o emprego industrial (proxy da atividade industrial) e a presença de gasodutos. Para o Brasil, os resultados não permitiram concluir pela existência de relação entre concentração industrial e disponibilidade de gás natural. Porém, para o Estado de São Paulo verificou-se que existe uma forte correlação positiva entre a presença de gasodutos e o nível de emprego para os segmentos heavy users, mesmo quando se consideram os efeitos de outras variáveis relevantes (custos de transporte, qualificação da mão de obra e ganhos com a especialização). / The use of natural gas has gained space in the Brazilian energy matrix, especially in the industrial sector. For a set of segments and industrial processes, the use of natural gas as a fuel or raw material involves significant environmental, technical and economic gains. The hypothesis motivating this work is the potential role that the availability of natural gas has as a promoter of regional development. The natural gas pipelines exhibits a clear pattern of spatial concentration, therefore it would be natural to expect that industries that took into account the availability of energy in their location decision became more concentrated, following the route of main pipelines. We defined two main pathways of analysis: (i) assessing the level of industry geographical (or spatial) concentration, verifying the existence of distinct patterns for the industry as a whole and a group of sectors defined as heavy users of natural gas (ceramics, textiles and chemicals), and (ii) the assessment and mapping of the spatial correlations between manufacturing employment (a proxy for industrial activity) and the presence of pipelines. For Brazil, the results failed to establish the existence of a relationship between industrial concentration and availability of natural gas. However, for the State of São Paulo has been found that there is a strong positive correlation between the presence of pipelines and employment for heavy users segments, even when considering the effects of other relevant variables (transportation costs, qualification of labor and gains from specialization - agglomeration economies).

Abstract not available

"1st February 2002" / Includes bibliographical references (leaves 265-273) / xi, 273 leaves : ill. (some col.), plates (col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Concerns the specialized requirements of welding procedures used on operational gas pipelines. / Thesis (Ph.D.)--University of Adelaide, Dept. of Mechanical Engineering, 2004?

An ever increasing demand to exploit oil and natural gas reserves has significantly increased extraction activities even in the remotest regions of the Arctic and sub-Arctic regions of the Canadian North. Steel pipelines are the most efficient mode for transporting and distributing these resources. These pipelines, particularly buried in cold region, often subjected to extreme geo-environmental conditions, where significant inelastic deformation may occur resulting in localized wrinkles. Under continued deformation, there is a possibility of excessive cross-sectional deformation at wrinkle locations, eventually leading to fracture or damage in the pipe wall jeopardizing pipeline safety and integrity . Prior research indicated that occurrence of fracture in pipe wrinkle is rare under monotonic load-deformation process. However, a recent field fracture was observed within the wrinkle location of an energy pipeline. Similar failure mode was observed in a laboratory specimen at the University of Alberta. Both field and laboratory observations had indicated that the final failure was a “tearing” failure at the fold of the telescopic wrinkles resulting from monotonic application of axial load not aligned with pipe axis. This research program was designed to study this specific failure mode and to develop design tool for pipeline engineers. This research started with examining the failed field and test specimens. A preliminary investigation was carried out using nonlinear finite element (FE) model to simulate test and field behaviour. Numerical results have indicated that even under monotonic loading, significant strain reversals could occur at the wrinkle fold . Presence of these strain reversals was proposed as the preliminary failure criterion responsible for this unique failure mechanism. In next phase, a full-scale ‘pipe-wrinkling’ test program was carried out concurrent to this research to better understand the loading condition responsible for this type of failure. Results of this test program have shown the presence of tearing fracture or rupture in the pipe walls of several of test specimens. A series of FE analyses was then carried out to predict and verify the behaviour of these test specimens. After successful simulation of the test behaviour, further numerical analyses were carried out using tension coupon model developed herein to simulate the material behaviour using the material test data and hence to formulate the limiting conditions in terms of critical strain responsible for the tearing failure. Based on these numerical results, a double criterion  ‘Strain Reversal’ and ‘Critical Equivalent Plastic Strain Limit’, were proposed to predict tearing fracture of wrinkled pipe under monotonic loading. Results of these numerical analyses have demonstrated that the proposed criteria predict this failure mode with reasonable accuracy. In the final phase of this research, a parametric study was carried out to consider the effect of different parameters on failure modes of wrinkled pipe. Results of this parametric study describe the range of parameters under which the tearing mechanism can/may exhibit. / Structural Engineering

This thesis aims to analyze the Turkish policy of being an energy hub. Within this context Turkey, as it is geographically very close to the two thirds of the world&#039 / s proven oil and natural gas reserves, has a very big advantage to manage its location and the purpose of this study is to discuss the measures taken to utilize this advantage. Therefore relative weakness of Turkey in comparison to the other actors like Russia, the USA or the EU and the strengths of the Turkish policy like the geopolitical advantage, the ethnic link between Turkey and the newly independent states of the Caspian and the already existing infrastructure for the transportation of oil and natural gas like Kirkuk-Yumurtalik Pipeline, Baku Tblisi Ceyhan Oil Pipeline, Ceyhan Terminal, and Baku Tblisi Erzurum Natural Gas Pipeline are discussed. With this respect, this study argues that, as a result of the existing and planned projects, Ceyhan&#039 / s claim to become a hub is a realistic objective and in addition to BTC and Kirkuk-Yumurtalik Pipeline, the realization of Samsun-Ceyhan Pipeline will increase Ceyhan&#039 / s potential as an energy hub.

The trenchless technology known as pipe ramming for construction of culverts and buried pipes under roadways or other infrastructure has gained significant popularity due to its cost-effectiveness and ability to alleviate surface disruptions associated with open-cut trenching. Although the experience with pipe ramming is increasing, there has been remarkably little technical guidance available for engineers to appropriately specify aspects of a pipeline or culvert installation, including the planning of feasible layouts, rates of penetration, pipe diameters, and hammers. This research provides a comprehensive engineering framework for evaluation of culvert installations at the planning phase to address the gaps in knowledge associated with pipe ramming. Presently there are no existing and proven techniques for prediction of settlement, vibration, driving stresses, soil resistance to ramming, and drivability for pipe ramming installations. This study has adopted existing drivability, soil resistance, settlement, and vibration prediction models from pipe jacking, microtunneling, and pile driving models and examined their applicability in pipe ramming installations, resulting in new and technology-specific design guidance. The development of this comprehensive engineering guidance is based on engineering calculations empirically tuned using a database of actual performance measurements. Field observations of five production installations and a full-scale experiment were conducted to form the performance database employed to understand the mechanics associated with pipe ramming installations, ranging from vertical ground movements, ground vibrations, and installation performance. Settlement prediction was evaluated using the inverted normal probability distribution based models, and these methods over-estimated the observed settlements close to the center of the pipes and under-estimated settlements at radial distances away from the pipe. A pipe-ramming-specific hyperbolic model was developed for better prediction of the vertical settlement induced by pipe ramming in granular soils. Attenuation of observed pipe ramming-induced vibrations was modeled using a simple semi-empirical approach, and the calibrated model resulted in reasonable predictions of the ground vibrations for granular soils. The static soil resistance to ramming was evaluated using the traditional quasi-static pipe jacking models and the models resulted in inaccurate predictions for instrumented pipe ramming installations. Therefore pipe ramming-specific static soil resistance models were developed for both the face and casing resistance in granular soils. Principles of stress wave theory routinely applied in the drivability analyses for pile foundations were adopted for the evaluation of the dynamic response pipes during ramming. Reliable estimates of the static soil resistance and dynamic soil parameters were obtained through signal matching processes. Data-informed drivability analysis were performed to simulate the magnitude of driving stresses and develop drivability curves which relate the penetration resistance of a given pipe and hammer to the range of static soil resistances. The study culminates in the first comprehensive framework and recommendations for the installation of pipes by ramming, and should help owners, consultants, and contractors to appropriately plan pipe ramming installations. / Graduation date: 2013

Lifelines provide the vital utilities for human being in the modern life. They convey a great variety of products in order to meet the general needs. Also, buried continuous pipelines are generally used to transmit energy sources, such as natural gas and crude oil, from production sources to target places. To be able to sustain this energy corridor efficiently and safely, interruption of the flow should be prevented as much as possible. This can be achieved providing target reliability index standing for the desired level of performance and reliability. For natural gas transmission, assessment of earthquake threats to buried continuous pipelines is the primary concern of this thesis in terms of reliability. Operating loads due to internal pressure and temperature changes are also discussed. Seismic wave propagation effects, liquefaction induced lateral spreading, including longitudinal and transverse permanent ground deformation effects, liquefaction induced buoyancy effects and fault crossing effects that the buried continuous pipelines subjected to are explained in detail. Limit state functions are presented for each one of the above mentioned earthquake effects combined with operating loads. Advanced First Order Second Moment method is used in reliability calculations. Two case studies are presented. In the first study, considering only the load effect due to internal pressure, reliability of an existing natural gas pipeline is evaluated. Additionally, safety factors are recommended for achieving the specified target reliability indexes. In the second case study, reliability of another existing natural gas pipeline subjected to above mentioned earthquake effects is evaluated in detail.

Functional verification is a critical problem facing the semiconductor industry: hardware designs are extremely complex and highly optimized, and even a single bug in deployed systems can cost more than $10 billion. We focus on the verification of pipelining, a key optimization that appears extensively in hardware systems such as microprocessors, multicore systems, and cache coherence protocols. Existing techniques for verifying pipelined machines either consume excessive amounts of time, effort, and resources, or are not applicable at the bit-level, the level of abstraction at which commercial systems are designed and functionally verified. We present a highly automated, efficient, compositional, and scalable refinement-based approach for the verification of bit-level pipelined machines. Our contributions include: (1) A complete compositional reasoning framework based on refinement. Our notion of refinement guarantees that pipelined machines satisfy the same safety and liveness properties as their instruction set architectures. In addition, our compositional framework can be used to decompose correctness proofs into smaller, more manageable pieces, leading to drastic reductions in verification times and a high-degree of scalability. (2) The development of ACL2-SMT, a verification system that integrates the popular ACL2 theorem prover (winner of the 2005 ACM Software System Award) with decision procedures. ACL2-SMT allows us to seamlessly take advantage of the two main approaches to hardware verification: theorem proving and decision procedures. (3) A proof methodology based on our compositional reasoning framework and ACL2-SMT that allows us to reduce the bit-level verification problem to a sequence of highly automated proof steps. (4) A collection of general-purpose refinement maps, functions that relate pipelined machine states to instruction set architecture states. These refinement maps provide more flexibility and lead to increased verification efficiency. The effectiveness of our approach is demonstrated by verifying various pipelined machine models, including a bit-level, Intel XScale inspired processor that implements 593 instructions and includes features such as branch prediction, precise exceptions, and predicated instruction execution.