Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 208-217). Also available in electronic version. Access restricted to campus users.

Thesis (M.S.)--University of Michigan, Ann Arbor, 1979. / Typescript (photocopy). eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 53-56).

Thesis (M.S.)--University of Michigan, 1947.

Submitted by João Arthur Martins (joao.arthur@ufpe.br) on 2015-04-16T18:52:34Z No. of bitstreams: 2 Dissertação_DIEGO 05-04-2014 (1).pdf: 2779613 bytes, checksum: 742c6279e64c289d647bb2bbb3b9d135 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-04-16T18:52:34Z (GMT). No. of bitstreams: 2 Dissertação_DIEGO 05-04-2014 (1).pdf: 2779613 bytes, checksum: 742c6279e64c289d647bb2bbb3b9d135 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2013 / CNPq / A busca na otimização dos processos construtivos para a indústria de petróleo e gás é uma preocupação sempre crescente por parte dos executores, visando principalmente ganhos em competitividade através do trinômio prazo, preço e qualidade.O objetivo destapesquisa é simular tensões residuais em juntas soldadas através do software SYSWELD e comparar os resultados com as medições obtidas em um corpo de prova de produção para qualificação de procedimento de soldagem, segundo o código ASME IX. As torres de destilação, atualmente em operação nas diversas unidades de refino de petróleo, são normalmente fabricadas em chapas de aço carbono (casco) com a aplicação de um revestimento do tipo “lining”, utilizando-se chapa de aço inoxidável, unidas através de cordões de soldas contínuos. Após um determinado período de operação de umaunidade surgem trincas na zona termicamente afetada (ZTA) neste revestimento. Experimentos realizados em outros trabalhos acadêmicos, onde foiutilizado um aço inoxidável AISI 317L como “lining” ao invés do aço inoxidável 316L, então usado, têm apresentado bons resultados para as juntas soldadas sem a ocorrência de trincas na ZTA ou no MS. A metodologia aplicada para a solução do problema foi realizar a soldagem de um corpo de prova (CP) com revestimento “lining”, usando osprocessos de soldagem FCAW-G e SMAW, em posição de soldagem equivalente ao casco da torre de destilação, e coletar as variáveis essências do procedimento (corrente, tensão e velocidade de soldagem médias), afim de constituir os inputs para a simulação computacional. Após realizar a soldagem do CP simular um ensaio de fadiga térmica no CP com temperaturas variando de 400°C (673 K) a 300°C (505 K) por um período de 0,5 hora, durante 3 ciclos, constituindo uma batelada e resfriar no forno até atingir a temperatura ambiente. Realizar uma inspeção visual nas juntas e aplicar um ensaio por líquido penetrante, com a finalidade de detectar trincas na ZAT e no MS. Os resultados obtidos pela simulação computacional, utilizando o aporte térmico induzido pelo processo de soldagem, mostraram-se satisfatórios e coerentes com os resultados experimentais. Desta forma foi demonstrada a eficiência da metodologia para obtenção das propriedades mecânicas na soldagem desses revestimentos “lining” com a alteração proposta. Assim, a simulação computacional pode seruma ferramenta importante para o projeto de juntas soldadas, podendo antecipar resultados de possíveis descontinuidades neste tipo de revestimento para equipamentos da indústria de Petróleo e Gás.

Demand for new underground transportation systems and utility networks has increased the use of tunneling in soft ground. Many of these tunnels have to be constructed in difficult soil conditions, with strict constraints on ground movement control. Technological advances, such as the pressurized shield or the New Austrian Tunneling Method (NATM), have, to some extent, overcome these difficulties. But the complex interaction between tunneling procedure, ground response, and liner support is still not fully understood. In this dissertation, the three aspects of tunneling, face stability, liner design, and ground surface settlement are analyzed for conditions that might be experienced on current projects. The study is intended to clarify some of the phenomena associated with the use of advanced tunneling techniques in soft grounds, and help improve the current design practice. The NATM generally uses "hand-mining" equipment for excavation, and shotcrete as temporary support of the tunnel wall. The amount and timing of support is optimized by continuously adapting the construction procedure to the conditions found at the tunnel face. In the present study, the applications of the finite element method to tunneling are reviewed, and it is used to model NATM tunneling projects. Using parametric studies, a simplified design method is proposed which allows an estimate of the liner forces and settlements associated with NATM tunneling to be obtained. Pressurized shields are used in soils with little to zero stand-up time to support the tunnel face during excavation. In this work, the face stability of shield tunnels in cohesionless soils is examined using limit analysis principles. Upper bound estimates of the critical face pressure are found in good agreement with results from centrifuge model tests. Empirical correlations for settlement estimates are re-examined, in view of case history data for shield driven tunnels. The ground movements observed on the F3 and F4 contracts of the Washington Metro are analyzed. Earth pressure balance shields were used on these projects. It is shown that difliculties were common in mixed face conditions, unless adequate techniques were used to prevent ground collapse to occur. / Ph. D.

Corrosion of iron and copper pipes can produce leaks and loss of efficiency in the water distribution system, elevate levels of contaminants at the tap, and cost billions of dollars annually in pipe replacement or rehabilitation. In situ pipe rehabilitation using cement mortar, polyurethane, and epoxy is a commonly employed method of dealing with aging yet structurally sound pipes because it is less expensive and less invasive than replacing pipe infrastructure. Although epoxy has been shown to be an effective solution to pipe corrosion, little research has been conducted regarding its impact on a comprehensive list of water quality parameters. This research addressed that gap in the literature by conducting short-term immersion tests in which new epoxy linings were exposed to reference tap waters containing one of three disinfectant treatments: no disinfectant, free chlorine, or chloramines. As a comparison, an aged epoxy-lined field sample was also tested. Water exposed to the liners under stagnant conditions was analyzed for the following water quality parameters: pH, ammonia, alkalinity, hardness, metals, disinfectant consumption, total organic carbon (TOC), semi-volatile organic compounds (SVOCs), disinfectant byproduct (DBP) formation, and odor. Results of the study showed relatively low impacts on water quality, as all USEPA drinking water regulations were met. Impacts were highest during the first 24 hour exposure period during which time significant disinfectant consumption was shown (> 90% free chlorine consumed, 13% chloramines consumed), high TOC was leached (2.6-6.2 mg/L), trihalomethanes and haloacetic acids were formed (both < 15 ug/L), Bisphenol-A, an endocrine disrupter, was detected (< 35 ug/L), and odor was reported by panelists at a moderate intensity and described as sweet/chemical/burning/chlorinous. Impacts were much less after the initial 24 hours, although odor remained noticeable throughout the 30 day study. Overall, water quality impacts were greatest in chlorinated waters and both new and aged epoxy showed slight differences in results. / Master of Science

The deployment of engineering models and design methods divorced from the effect that mechanised shield tunnelling with tunnel boring machines (TBMs) has on concrete segmental linings (CSLs) can lead to either material waste or structural damage within the tunnel design life. Most research to date on CSL behaviour during construction neglects the sequential ring loading and TBM-lining transverse interactions, which this thesis proved to be key in the short and long term behaviour of CSLs and whose study is essential if the design and maintenance of CSL structures is ever to be optimised. This thesis investigates the longitudinal and transverse behaviour of CSL structures simultaneously backfilled with bicomponent grouts (BGs) during tunnelling, and how this early response influences long term behaviour. The research work is drawn on three pillars that enable cross-validation of conclusions: analytical models, three-dimensional numerical simulations and the interpretation of the Crossrail's Thames tunnel (CTT) field data, which included distributed fibre optic strain (DFOS) data. A theoretical framework ranging from construction loading scenarios to the mechanisms underlying structural damage is described for the future development of limit state design methods. Analytical models of longitudinal behaviour are also proposed. The study of joint geometries, temporary spear bolts and DFOS sensing in CSL construction monitoring is included as ancillary research. The solution developed for a sequential elastic rod subjected to a trilinear temperature profile and in shear interaction with the elastic ground predicts accurately the early tunnel pre-stressing relaxation caused by grout hardening, e.g. ≈50% in the CTT. The proposed sequential elastic beam model, which incorporates the effects of stage-varying net TBM moments, transverse loads and lining pressure gradients within the tunnel unsupported length, estimates satisfactorily the history of tunnel beam response during construction for a realistic expression of the lining stiffness. A potential damage assessment method for the early detection of tunnel sections prone to ring joint damage was proposed. The TBM-lining transverse interaction determines the CSL ring behaviour at the early stages of tunnelling. The ring response resultant from this interaction is irrecoverable and contributes to the long term total deformations and internal forces; in tunnels excavated in grounds with Ko≈1, it becomes the major source of ring distortion. The main transverse actions are the sealing pressures, which are inversely related to the tail clearance, and the transverse load of oblique hydraulic jacks. When the non-bedded rings are eccentric with respect to the shield tail, the ring distortion increases the risk of cracking near the rear corners and spalling at the ram pad interspaces of constrained segments. The ring distortion is directly related to the pressure gradients, the unsupported length and the ring flexibility. When individual segments rotate outwards under the action of transverse ram loads, e.g. the outer springline segment during pronounced TBM steering around a horizontal curve, the localised action of the sealing pressures can result in longitudinal cracking at the intrados of the segment front. This study represents a qualitative leap towards the optimisation of CSL design, shifting the attention of researchers and designers to TBM-lining transverse interactions as the most determinant factor of structural response during construction in CSLs simultaneously backfilled with BGs.

Šiame diplominiame darbe autorė apžvelgia buvusius ir dabartyje taikomus molbertinės tapybos dubliavimo metodus bei naudojamas medžiagas. Aprašomi žinomi paveikslų dubliavimo būdai Europoje.Nagrinėjami molbertinės tapybos paveikslų dubliavimo metodai LDM Prano Gudymo restauraimo centre, taikyti nuo įsikūrimo iki šių dienų. Lyginami įvairūs, skirtingų kūrinių konservavimo, dubliavimo atvejai. Detaliai aprašomas paveikslo "Biblijinė scena" konservavimo, dubliavimo procesas. Šiame darbe senieji žinomi molbertinės tapybos dubliavimo būdai bei panaudotos medžiagos lyginami su dabarties praktika ir metodais. Tyrimas atskleidė, jog kiekvienam darbui reikalingas kūrybiškas, metodiškas, mokslinis paveikslų konservavimo, dubliavimo metodas bei taikomos medžiagos. / Author of this Master’s Thesis reviews former and present methods and techniques of the lining of canvas paintings. Furthermore, all known European lining methods are described. Lining methods of the canv-as painting applied in Pranas Gudynas Center for Restoration since its foundation until present days are reviewed. Author reviews various cases of conservation and lining of the canvas paintings in Lithuania. Thesis describes in details conservation and lining process of the painting “Biblical Scene”. Old canvas paintings methods of lining, including the material used for lining, are compared in this Master’s Thesis. Research made reveals the fact that each piece of art needs creative, methodological, scientific approach to the conservation and lining methods and the materials used.

This diploma thesis topic is cooperation among airlines. Main part focuses on areas and forms of airline cooperation e.g. inter-lining, code-sharing, joint ventures. A chapter is dedicated to the impact on competition and another one analysis the structure of global airline alliances. Basic overview of air transport and legal aspects influencing the nature of cooperation among airlines is also included.

Taiwan Island is surrender by ocean; the ninety percent of raw material for economic development depends on sea transportation. Thus, it is important to keep sea line of communication for using without any obstruction. As known, the most serious threat to sea line of communication of Taiwan is from submarine of PRC. However, the KNOX class frigate is the warship which is designed for ASW especially by USN. She is still the major ASW ship for Taiwan navy so far. For this reason, the officers working on the KNOX is the main objective to this case study for relationship between the job satisfaction and turnover intention. Consequently, the recommendation according to the study conclusion was provided. The method was used in this study were theory review, questionnaires, and statistics analysis which covered t-test, one-way ANOVA, Pearson product-moment correlation, and regression analysis. Accordingly, the study results are follows, A. The job satisfaction of officers was moderate and they were also precious to the current job without significant turnover tendency. B. For the demographic aspect, unexpectedly, female officers had higher job satisfaction than male ones. Unmarried officers had higher job satisfaction than married ones. The age between 26 and 30 years old officers had lower job satisfaction than others. C. The most significant influence of key factors on job satisfaction were career expectation, job perspective, fair reorganization, motivated strategy, and military culture. D. The negative relation was resulted from the job satisfaction and turnover intention of the KNOX officers.