The aim of this thesis is to provide a design tool for the engineering analysis of the dynamics of a flexible riser system. The design tool is piovided in the form of a computer program. The two main requirements of such a program are that it is realistic and practical to use. The necessary theory is developed to allow these requirements to be satisfied. To ensure accuracy checks are made against model tests and known analytical solutions. How the computer program may be used is shown by analysing a particular riser configuration.

This thesis describes a study that aimed to assess the psychophysiological effects of offshore survival training, and to investigate whether responses of trainees differed according to age. A group of 99 subjects, randomly selected from across a wide age range, volunteered and subsequently were monitored during the training. The sample population were split into 2 groups according to the training course attended, refresher or combined survival and fire fighting course. Physiological and psychological measurements, chosen as indicators of stress, were performed on these subjects. Attention was centred on 4 particular events: helicopter underwater escape training (HUET); simulated platform abandonment using totally enclosed motor propelled survival craft; simulated platform abandonment into liferafts; and self rescue from a smoke filled room. State anxiety and urinary free cortisol were assessed early on each morning. Anxiety was also measured before the 4 chosen events. Early morning anxiety and urinary free cortisol were observed to peak on the first day of training, then each showed a very similar pattern of a decline to a plateau. On assessing all combined subjects' anxiety scores in sequence, values were found to be relatively lower towards the end of the course. These results suggested that subjects suffered from pre-course apprehensions that may have caused elevations in anxiety scores during the course. It was also found that subjects with high urinary free cortisol values on day 1, had relatively higher heart rates later in the course. Despite variation between the training courses, very similar mean heart rates were recorded in combined and refresher subjects. Relatively elevated heart rates were detected during the HUET brief. This was proposed to be the result of psychological activation, probably anxiety. Indicators of links among physiological and psychological measures were thus detected. Stronger and more consistent relationships may have been observed had more extensive data been available. Age effects were also detected, older refreshers had lower levels of anxiety, but found the course relatively more demanding. The lower anxiety levels were proposed to result from older refreshers having more training experience.

No description available.

The effects of wave directionality on the loads and motions of long structures is investigated in this thesis. A numerical method based on Green's theorem is developed to compute the exciting forces and hydrodynamic coefficients due to the interaction of a regular oblique wave train with an infinitely long, semi-immersed floating cylinder of arbitrary shape. Comparisons are made with previous results obtained using other solution techniques. The results obtained from the solution of the oblique wave diffraction problem are used to determine the transfer functions and response amplitude operators for a structure of finite length and hence the loads and amplitudes of motion of the structure in short-crested seas. The wave loads and body motions in short-crested seas are compared to corresponding results for long-crested seas. This is expressed as a directionally averaged, frequency dependent reduction factor for the wave loads and a response ratio for the body motions. Numerical results are presented for the force reduction factor and response ratio of a long floating box subject to a directional wave spectrum with a cosine power type energy spreading function. Applications of the results of the present procedure include such long structures as floating bridges and breakwaters. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

A numerical method is described to study directional wave effects on large offshore structures of arbitrary shape, based on an extension of linear diffraction wave theory for regular waves. A computer program has been developed to compute loading transfer functions and response amplitude operators and hence the loading and response spectra for both long- and short-crested random waves. Cosine powered directional spreading functions which are independent of frequency have been used to account for the shortcrestedness of waves. Comparisions of the results for long- and short-crested seas show that there is a significant reduction in the loading, and hence in the response, due to shortcrestedness of waves. The probabilistic properties of the components of the loading and response are described. Since the sea surface is assumed to follow a Gaussian distribution, these are also random Gaussian variables. In short-crested waves, the loading and response components occur both in-line and transverse to the principal wave direction. Thus the maximum horizontal loading and response may occur in an arbitrary horizontal direction. An analytical method is developed to describe also the probabilistic properties of the maxima of the components and the maxima of their horizontal resultants. In the present study, results are described for a freely floating box. Comparisons are made with published results and are found to be quite favourable. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

The present investigation considers the hydrodynamic forces acting on a slender structure subjected to a combined wave and current flow regime. The experimental aspect of the study measured the in-line peak-to-peak forces on a vertical cylinder mounted in a wave-current flume. Although there were some inconsistencies in the data, the general trend indicated a substantial increase in the force with a positive underlying current and a less pronounced increase for a negative current. A numerical analysis of the problem evaluated Morison's equation using the current-invariant force transfer coefficients and flow kinematics obtained through Stokes Fifth Order Wave Theory. The results of this analysis revealed a trend qualitatively similar to that found experimentally. The important distinction between the results obtained through the experimental investigation and those obtained numerically was the consistent over-prediction observed in the numerical analysis. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

This thesis asks why the Australian Labor Party was opposed to the policy of offshore detention for unauthorized maritime arrivals from 2002 to 2008, when they ended it, only to bring it back a few years later in 2011? The Australian Labor Party, the major left-wing party in Australia, campaigned against offshore detention as being antithetical to Australia's liberal values, which proclaimed human rights as an Australian value. After winning the 2007 federal election the policy of offshore detention was ended. By 2009, the Australian Labor Party changed its position on the issue going into the 2010 federal election. In 2011, the Australian Labor Party announced that it was looking to bring back offshore detention. The explanation for this change I find is that the Australian Labor Party wanted to hold political power. As the minority party the Australian Labor Party used the policy of offshore detention for unauthorized maritime arrivals to attack the Liberal-National Coalition-controlled government as being a financial waste and cruelly inhumane. After ending the policy, the rates of unauthorized maritime arrivals increased drastically, creating pressure on the Australian Labor Party to find a solution or risk losing control of the Australian government, which it did in 2011. / Master of Arts / This thesis asks why the Australian Labor Party was opposed to the policy of offshore detention for unauthorized maritime arrivals from 2002 to 2008, when they ended it, only to bring it back a few years later in 2011? The explanation for this change I find is that the Australian Labor Party wanted to hold political power. As the minority party the Australian Labor Party used the policy of offshore detention for unauthorized maritime arrivals to attack the Liberal-National Coalition-controlled government as being a financial waste and cruelly inhumane. After ending the policy, the rates of unauthorized maritime arrivals increased drastically, creating pressure on the Australian Labor Party to find a solution or risk losing control of the Australian government, which it did in 2011.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Submitted by Mateus Gomes (mateussg@msn.com) on 2018-05-25T17:01:45Z No. of bitstreams: 2 Dissertacao Mateus Gomes.pdf: 6830547 bytes, checksum: 47179b5d6a73fd8cdb299c49042f908c (MD5) Carta comprovante Mateus Gomes.jpg: 517376 bytes, checksum: 897b93ae582b7da42bf02be5122cf5a6 (MD5) / Approved for entry into archive by Milena Rubi ( ri.bso@ufscar.br) on 2018-06-04T13:13:11Z (GMT) No. of bitstreams: 2 Dissertacao Mateus Gomes.pdf: 6830547 bytes, checksum: 47179b5d6a73fd8cdb299c49042f908c (MD5) Carta comprovante Mateus Gomes.jpg: 517376 bytes, checksum: 897b93ae582b7da42bf02be5122cf5a6 (MD5) / Approved for entry into archive by Milena Rubi ( ri.bso@ufscar.br) on 2018-06-04T13:13:24Z (GMT) No. of bitstreams: 2 Dissertacao Mateus Gomes.pdf: 6830547 bytes, checksum: 47179b5d6a73fd8cdb299c49042f908c (MD5) Carta comprovante Mateus Gomes.jpg: 517376 bytes, checksum: 897b93ae582b7da42bf02be5122cf5a6 (MD5) / Made available in DSpace on 2018-06-04T13:13:34Z (GMT). No. of bitstreams: 2 Dissertacao Mateus Gomes.pdf: 6830547 bytes, checksum: 47179b5d6a73fd8cdb299c49042f908c (MD5) Carta comprovante Mateus Gomes.jpg: 517376 bytes, checksum: 897b93ae582b7da42bf02be5122cf5a6 (MD5) Previous issue date: 2018-02-26 / Não recebi financiamento / Electricity generation is a global challenge to be faced by several countries. This has led to the pursuit and development of new clean technologies to sustainable supply of the growing world demand for energy. Currently the main sources of renewable energy are: biomass, solar, geothermal, tidal, wind on and offshore (land and sea). Among these sources, wind energy presents worldwide growth and recently a significant increase in its use in the offshore segment. Brazil is among the ten largest onshore wind power producers in the world, however it does not have yet any offshore wind farms. The country has great potential for exploration of offshore wind power, since there are large population concentrations with increasing energy demands in coastal areas and an Exclusive Economic Zone (EEZ) of approximately 3.5 × 10^6 km^2. The objective of this work was to develop a methodology for the use of offshore wind energy through the proposal of an offshore wind farm on the Southeast coast of Brazil. The study was carried out for the Southeast region of Brazil in order to complement the energy matrix of the region, which today is mostly composed of hydroelectric power plants. The offshore wind farm proposal was carried out following the methodology developed in this work, which is based on two different types of data collection sources: ocean buoys and automatic meteorological stations. Weibull frequency distributions were calculated for each data collection source, power curve and capacity factor for the selected wind turbines in each locality, in order to identify the best location for the utilization of offshore wind energy in the Southeast region. The location of the collection point Cabo Frio 2 presented the best wind characteristics for offshore wind energy production, however its installation would require great complexity, so the selected collection point for the installation of an offshore wind farm in this work was the station A606 - Arraial do Cabo. The capacity factor calculated in the selected region was 0,51 for the wind turbine with lower power and 0,39 for the wind turbine with higher power, and the calculated wind speed at the reference height was 7,77 m/s, which is an adequate value for wind energy production. The wind farm proposed for this region is capable of supplying annually 604.461 MWh through 39 wind turbines, which are enough to supply the energy demand of approximately 115,870 residences during the whole year in a county located in the state of Rio de Janeiro. / A geração de energia elétrica é um desafio mundial a ser enfrentado por vários países. Isso tem levado a busca e desenvolvimento de novas tecnologias limpas para o abastecimento de forma sustentável da crescente demanda mundial por energia. As principais fontes de energia renováveis da atualidade são: biomassa, solar, geotérmica, maremotriz, eólica on e offshore (terra e mar). Dentre essas fontes, a energia eólica sinaliza crescimento mundial e recentemente um aumento significativo na sua utilização no segmento offshore. O Brasil está entre os dez maiores produtores mundiais de energia eólica onshore, entretanto ainda não possui empreendimentos eólicos offshore. O país possui grande potencial para exploração da fonte eólica offshore, visto que existem grandes concentrações populacionais com crescentes demandas energéticas em áreas costeiras e uma Zona Econômica Exclusiva (ZEE) de aproximadamente 3.5 × 10^6 km^2. O objetivo deste trabalho foi desenvolver uma metodologia para utilização da energia eólica offshore através da proposta de um parque eólico offshore no litoral Sudeste do Brasil. O estudo foi realizado para a região Sudeste do Brasil com intuito de complementar a matriz energética elétrica da região, que hoje é em sua maioria composta por hidroelétricas. A proposta do parque eólico offshore foi realizada seguindo a metodologia desenvolvida neste trabalho, que se baseia em dois diferentes tipos de fontes de coleta de dados: boias oceânicas e estações meteorológicas automáticas. Foram calculadas as distribuições de frequência de Weibull para cada fonte de coleta de dados, curva de potência e o fator de capacidade para os aerogeradores selecionados em cada localidade, com objetivo de identificar a melhor localização para utilização de energia eólica offshore na região sudeste. Os resultados mostram que, dentre os pontos de coleta de dados analisados, o local do ponto de coletas Cabo Frio 2 apresentou as melhoras características de ventos para exploração de energia eólica offshore, entretanto sua instalação demandaria grande complexidade, por isso o ponto de coleta selecionado para instalação de um parque eólico offshore neste trabalho foi a estação A606 - Arraial do Cabo. O fator de capacidade calculado na região selecionada foi de 0, 51 para o aerogerador com menor potência e 0,39 para o aerogerador com maior potência, e a velocidade no local calculada na altura de referência foi de 7,77 m/s, que é um valor adequado para produção de energia eólica. O parque proposto para esta região é capaz de fornecer anualmente 604.461 MWh, utilizando 39 aerogeradores, que são suficientes para abastecer cerca de 115.870 domicílios durante todo o ano para um município localizado no estado do Rio de Janeiro.

Thesis. 1977. Ocean E.--Massachusetts Institute of Technology. Dept. of Ocean Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / Ocean E.