Multi-directional polymer matrix composite materials are increasingly used in load-bearing structural applications ranging from primary aircraft structures and automotive parts to rehabilitation of bridges. Long-term durability, characterized by time-dependent degradation in strength (known as creep-rupture) and modulus (known as creep), is an important concern in these applications. Despite the experimental evidence on the influence of time-dependent damage on creep and creep rupture of multi-directional composites, current level of understanding of this is very limited. Hence, the focus of this thesis is to develop a clear understanding of the time dependent evolution of various damage modes and their influence on creep rupture of polymer matrix composite laminates.Three laminates [0/90/0], [±45/902]s, and [0/902]s were subjected to a wide range of constant stresses at various test temperatures and creep rupture time was recorded.The various damage modes that developed, with stress during tensile testing, and with time during constant stress creep rupture testing were transverse cracking, vertical cracking, delamination, vertical splitting and fiber fracture.The appearance of these damages were time dependent confirming that the FPF stress is time-dependent, while the conventional wisdom is to consider it to be time-independent in design. Beyond FPF, the damage continued to evolve for a certain period of time beyond which additional damage modes started to evolve influencing the evolution rate of one-another.The percentage of creep rupture time during which a single mode of damage was evolving decreased with increase in applied stress and test temperature.Based on these results it is concluded that creep rupture of multidirectional laminates is influenced by contributions from a complex interaction of various damage modes that evolve with time, suggesting that creep rupture predictions could be good approximations only. / May 2008

Thesis (Ph. D.)--Columbia College, 1894. / Translation of: De mundi sensibilis atque intelligibilis forma et principiis. Vita.

Thesis (M.S.)--Kent State University, 2008. / Title from PDF t.p. (viewed Oct. 5, 2009). Advisor: Peter Dahl. Keywords: Geochronology; Radiometric Dating; Plate Tectonics. Includes bibliographical references (p. 106-109).

Thesis (Ph.D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on March 6, 2009) Includes bibliographical references.

The relative magnitude of an event (number magnitude) can have direct implications on timing judgments. Previous studies have found that large magnitude numbers are perceived to have longer durations than those of smaller numbers. This bias can be accounted for in several ways; first, the internal clock model theorizes that stimulus magnitude directly interacts with the components of a dedicated cognitive timer by increasing pacemaker speed. Another explanation posits that different quantitative dimensions (space, time, size, intensity and number) are all represented within a common cortical metric thus facilitating interactions within and across dimensions. I have expanded on this framework by proposing that perceived duration is inferred using flexibly applied rules of thumbs (heuristics) in which information from a more accessible dimension (e.g., number magnitude) is substituted for duration. Three paradigms were used to test this theory. First, commonalities in how the intervals separating discrete stimuli of different magnitudes were judged was examined across a variety of quantitative dimensions (number, size, and colour saturation). Perceived duration judgments increased systematically as the magnitude difference between the stimuli increased. This finding was robust against manipulations to sequence direction, and order, suggesting that interval duration was estimated by substituting information regarding the absolute magnitude difference. Second, the impact of number magnitude on sound intensity judgments was examined. When target sounds were presented simultaneously with large digits, they were categorized as loud more frequently, suggesting that participants substituted number magnitude when performing difficult sound intensity judgments in a manner similar to when judging duration. Third, the repetition of magnitude information presented in either symbolic (Arabic digits) or non symbolic (numerosities) formats was manipulated prior to the presentation of a target number, whose duration was judged. The results demonstrated that large numbers were judged to last for longer durations relative to small numbers. Furthermore, context had an effect in which a greater discrepancy in the target’s numerical magnitude from the initial context sequence resulted in a longer perceived duration. The results across all three paradigms suggest that people generally employ information regarding one magnitude dimension (number) when making difficult perceptual decisions in a related dimension (time, sound intensity). / February 2016

The subject of this thesis is the economics of working time in Great Britain and Australia, with special reference to the length and timing of working hours. First, the incidence of and trends in work patterns, in Great Britain and Australia, are examined. The incidence of and trends in, normal hours, actual hours, overtime and part-time work in Britain and Australia, show a great deal of similarity. It is more difficult to compare "non-standard working hours" (hours outside of the normal spread of hours, e.g. shift work) because of problems with the data. It is clear, however, that non-standard hours of work are important in both countries.

Dissertação (mestrado) - Universidade Federal de Santa Catarina. Centro Tecnologico / Made available in DSpace on 2012-10-16T05:13:58Z (GMT). No. of bitstreams: 0Bitstream added on 2016-01-08T18:05:31Z : No. of bitstreams: 1 93250.pdf: 3382933 bytes, checksum: 0bc99eb6c1f2ee26b192039cdd2ffe45 (MD5) / O layout industrial é um elemento de grande importância para os sistemas de produção. Com um layout eficiente é possível racionalizar os esforços para a agregação de valor aos produtos, através da diminuição de atividades que não contribuem para esta adição de valor. Exemplos destas atividades são o transporte de produtos em processamento, o fluxo de produção em contra corrente e os estoques intermediários. No sistema de produção Just in Time, o layout industrial, além de reduzir o número de atividades que não agregam valor, deve também possibilitar a flexibilização dos meios de produção e a integração da manufatura, atributos que podem implicar em vantagem competitiva em relação a empresas concorrentes, pois dotam a fábrica de uma grande velocidade de resposta frente as exigências do mercado. O uso do computador para o projeto do layout industrial deve-se ao fato de que por meio deste é possível sistematizar o processo de projeto, permitindo que as tomadas de decisão sejam feitas de acordo com regras claras e bem definidas, além de ser possível contar com extensas bases de dados. O modelo computacional desenvolvido neste trabalho visa superar alguns pontos fracos apresentados por softwares já existentes que se dedicam ao projeto do layout industrial, além de inserir este projeto no contexto do sistema Just in Time.

Dissertação (mestrado) - Universidade Federal de Santa Catarina. Centro Socio-Economico / Made available in DSpace on 2012-10-16T22:44:01Z (GMT). No. of bitstreams: 0Bitstream added on 2016-01-08T17:35:49Z : No. of bitstreams: 1 87961.pdf: 6206279 bytes, checksum: 6d657c892c435aae2543fb472bac52ca (MD5) / O objetivo desta pesquisa é verificar "in loco" o impacto da adoção de uma inovação tecnológica, especificamente o just-in-time, na configuração do sistema de controle organizacional. Para este fim, foi empregado o método do estudo de caso que possibilitou analisar em detalhes os controles sobre o processo produtivo, sobre o controle de qualidade, bem como o controle sobre as pessoas. Através de uma avaliação longitudinal, foram focalizados os momentos anterior e posterior à introdução do just-in-time na área operacional da Hering Têxtil S/A. Os resultados obtidos demonstram a ocorrência de uma série de alterações no sistema de controle organizacional, como a intensificação dos controles sobre o processo e sobre as pessoas, a modificação nos mecanismos de controle de qualidade e, por último, a diminuição dos níveis hierárquicos, paralelamente, ao aumento da amplitude de controle dos supervisores, no nível operacional.

Thesis (Ed.M.)--Boston University / The purpose of this study was to determine the kinds of exercises using time concepts found in the textbooks in history for children in Grades IV, V and VI.

No description available.