228 resultados para DUCTED PROPELLER
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Mode of access: Internet.
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Phineas Pett, beginnings of English shipbuilding.--Francis Pettit Smith, practical introducer of the screw propeller.--John Harrison, inventor of the marine chronometer.--John Lombe, introducer of the silk industry into England.--William Murdock, his life and inventions.--Frederick Koenig, inventor of the steam-printing machine.--The Walters of the 'Times', invention of the Walter press.--William Clowes, book-printing by steam.--Charles Bianconi, a lesson of self-help in Ireland.--Industry in Ireland, through Connaught and Ulster to Belfast.--Harland, E. J. Ship-building in Belfast.--Astronomers and students in humble life, a new chapter in the 'Pursuit of knowledge under difficulties'.
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From June 1995 to August 2002 we assessed green turtle (Chelonia mydas) population structure and survival, and identified human impact, at Bahia de los Angeles, a large bay that was once the site of the greatest sea turtle harvest rates in the Gulf of California, Mexico. Turtles were captured live with entanglement nets and mortality was quantified through stranding surveys and flipper tag recoveries. A total of 14,820 netting hours (617.5 d) resulted in 255 captures of 200 green turtles. Straight-carapace length and mass ranged from 46.0-100.0 cm (mean = 74.3 +/- 0.7 cm) and 14.5-145.0 kg (mean = 61.5 +/- 1.7 kg), respectively. The size-frequency distribution remained stable during all years and among all capture locations. Anthropogenic-derived injuries ranging from missing flippers to boat propeller scars were present in 4% of captured turtles. Remains of 18 turtles were found at dumpsites, nine stranded turtles were encountered in the study area, and flipper tags from seven turtles were recovered. Survival was estimated at 0.58 for juveniles and 0.97 for adults using a joint live-recapture and dead-recovery model (Burnham model). Low survival among juveniles, declining annual catch per unit effort, and the presence of butchered carcasses indicated human activities continue to impact green turtles at this foraging area.
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The history of human experimentation in the twelve years between Hitler's rise to power and the end of the Second World War is notorious in the annals of the twen- tieth century. The horrific experiments conducted at Dachau, Auschwitz, Ravens- brueck, Birkenau, and other National Socialist concentration camps reflected an extreme indifference to human life and human suffering. Unfortunately, they do not reflect the extent and complexity of the human experiments undertaken in the years between 1933 and 1945. Following the prosecution of twenty-three high-ranking National Socialist physicians and medical administrators for war crimes and crimes against humanity in the Nuremberg Medical Trial (United States v. Karl Brandt et al.), scholars have rightly focused attention on the nightmarish researches con- ducted by a small group of investigators on concentration camp inmates. Less well known are alternative pathways that brought investigators to undertake human ex- perimentation in other laboratories, settings, and nations.
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Decision-making in product quality is an indispensable stage in product development, in order to reduce product development risk. Based on the identification of the deficiencies of quality function deployment (QFD) and failure modes and effects analysis (FMEA), a novel decision-making method is presented that draws upon a knowledge network of failure scenarios. An ontological expression of failure scenarios is presented together with a framework of failure knowledge network (FKN). According to the roles of quality characteristics (QCs) in failure processing, QCs are set into three categories namely perceptible QCs, restrictive QCs, and controllable QCs, which present the monitor targets, control targets and improvement targets respectively for quality management. A mathematical model and algorithms based on the analytic network process (ANP) is introduced for calculating the priority of QCs with respect to different development scenarios. A case study is provided according to the proposed decision-making procedure based on FKN. This methodology is applied in the propeller design process to solve the problem of prioritising QCs. This paper provides a practical approach for decision-making in product quality. Copyright © 2011 Inderscience Enterprises Ltd.
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Background: Oral anticoagulation (OAC) reduces stroke risk in patients with atrial fibrillation (AF); however it is still underutilized and sometimes refused by patients. Two inter-related studies were undertaken to understand the experiences and what influences this un- derutilisation of warfarin treatment in AF patients. These studies explored physician and patient experiences of AF and OAC treatment. The paper focuses on specific sub-themes from the study that explored patients’ experiences will be discussed. Aim: The study in question aimed to explore the experiences which influence patients’ decisions to accept, decline or discontinue OAC. Methods: Semi-structured individual interviews with patients were con- ducted. Three sub-groups of patients (n = 11) diagnosed with AF were interviewed; those who accepted, refused, and who discontinued war- farin. Interpretative phenomenological analysis (IPA) was used to examine the data. IPA is a qualitative method that focuses on how participants make sense of an experiences phenomenon Results: Three over-arching themes comprised patients’ experiences: (i)the initial consultation, (ii) life after the consultation, and (iii) patients’reflections. In the last theme, patients reflected on their perceptions ofaspirin and warfarin. Aspirin was perceived as a natural wonder-drugwhile warfarin was perceived as a dangerous drug usually given to peo-ple at the end of their life. Interestingly they perceive both drugs as‘old’. However, for aspirin it had a positive association, old meaningtried and tested. While for warfarin, old meant ‘has been around fortoo long’.Conclusion: Media had an important role in how patients’ perceptionsof these two drugs were influenced. Literature shows that framingtechniques, i.e. using certain words or phrases such as ‘rat poison’, areprocesses adopted by media to alter medical knowledge into lay per-son’s language. Patients in turn form negative cognitive schemas,between the word ‘poison’ and warfarin, leading to the negative per-ception of warfarin which could influence non-adherence to treatment.This qualitative research highlighted the potential influences of themedia on AF patient perceptions commencing OAC treatment. Theassociation between media stimuli and patient perceptions on OACshould be further explored. The influential power of lay-media couldalso be instrumental in disseminating appropriate educational materialto the public
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To predict the maneuvering performance of a propelled SPAR vessel, a mathematical model was established as a path simulator. A system-based mathematical model was chosen as it offers advantages in cost and time over full Computational Fluid Dynamics (CFD) simulations. The model is intended to provide a means of optimizing the maneuvering performance of this new vessel type. In this study the hydrodynamic forces and control forces are investigated as individual components, combined in a vectorial setting, and transferred to a body-fixed basis. SPAR vessels are known to be very sensitive to large amplitude motions during maneuvers due to the relatively small hydrostatic restoring forces. Previous model tests of SPAR vessels have shown significant roll and pitch amplitudes, especially during course change maneuvers. Thus, a full 6 DOF equation of motion was employed in the current numerical model. The mathematical model employed in this study was a combination of the model introduced by the Maneuvering Modeling Group (MMG) and the Abkowitz (1964) model. The new model represents the forces applied to the ship hull, the propeller forces and the rudder forces independently, as proposed by the MMG, but uses a 6DOF equation of motion introduced by Abkowitz to describe the motion of a maneuvering ship. The mathematical model was used to simulate the trajectory and motions of the propelled SPAR vessel in 10˚/10˚, 20˚/20˚ and 30˚/30˚ standard zig-zag maneuvers, as well as turning circle tests at rudder angles of 20˚ and 30˚. The simulation results were used to determine the maneuverability parameters (e.g. advance, transfer and tactical diameter) of the vessel. The final model provides the means of predicting and assessing the performance of the vessel type and can be easily adapted to specific vessel configurations based on the generic SPAR-type vessel used in this study.
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This work supports the formalist education s improvement of the Brazilian architect and urban designer through a better application and systematization of the computer science s teaching potentialities. The research analyzes the discipline introduction in the Brazilian courses: Computer Science Applied to Architecture and Urbanism (InfoAU) in the Architecture and Urbanism Courses of Brazil (CAUs). It goes since the discipline was obligated by the MEC s Regulation nr. 1.770 from 1994 until the CNE/CES Resolution nr. 6 from 2006; it comprehends the discipline implantation, development and current context, in order to get more detailed, the research analyses three federal universities from the Northeast of the country: UFRN, UFPB and UFPE. Once identified the historical educational needs in the CAUs, the study focus on the computer science s increasing potential as an agent of integration, communication, development and knowledge/data management. It points out new social perspectives for a better use of this tool/mechanism, which adequately structuralized and integrated, creates propitious educational and professional performance/recycling conditions and a propeller instrument of research and extension activities. Among this work, it is suggested the aggregation of elements, which are complementary to the InfoAU discipline s reorganization, throughout a computerization s plan for the CAUs, extensive to the professional formation, generating a virtuous cycle in several activities of the academic, administrative and, research and extension s departments. Therefore, the InfoAU in the Brazilian CAUs context was analyzed; the main solutions and problems found were systemized; the possibilities of computer science s uses inside AU ware structuralized, InfoAU discipline s improvement plan was also defined, as well as strategies for the implementation of the computerization s plan for the CAUs, which would guarantee its maintenance in a continuity perspective
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Dissertação (mestrado)—Universidade de Brasília, Faculdade UnB Gama, Programa de Pós-graduação em Integridade de Materiais da Engenharia, 2015.
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Dissertação (mestrado)—Universidade de Brasília, Brasília, Faculdade de Ciências da Saúde, Departamento de Nutrição, Programa de Pós-Graduação em Nutrição Humana, 2016.
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ASHRAE 34, based on ASTM E681, was improved by identifying and rectifying deficiencies in ASTM E681. An ASTM E681 apparatus and procedure was developed with gaseous refrigerant testing in mind. The plumbing was improved by ensuring that the pressure readings could be constantly monitored while decreasing leakage potential. An original electrical system was designed and constructed for the ignition system. Additionally, a control panel was constructed to isolate hazardous electrical elements, and facilitate the testing, while simultaneously organizing the critical plumbing and ignition components. 3D printing efficiently produced heat-resistant, nonreactive, and structurally stable lower electrode spacers, propellers, and propeller bars. The heating system was designed to ensure even temperature throughout the apparatus. The humidity system was designed to accurately condition the air. Recommendations to improve ASTM E681 are provided. The research can be built on to improve the accuracy and reproducibility of ASTM E681.
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This work supports the formalist education s improvement of the Brazilian architect and urban designer through a better application and systematization of the computer science s teaching potentialities. The research analyzes the discipline introduction in the Brazilian courses: Computer Science Applied to Architecture and Urbanism (InfoAU) in the Architecture and Urbanism Courses of Brazil (CAUs). It goes since the discipline was obligated by the MEC s Regulation nr. 1.770 from 1994 until the CNE/CES Resolution nr. 6 from 2006; it comprehends the discipline implantation, development and current context, in order to get more detailed, the research analyses three federal universities from the Northeast of the country: UFRN, UFPB and UFPE. Once identified the historical educational needs in the CAUs, the study focus on the computer science s increasing potential as an agent of integration, communication, development and knowledge/data management. It points out new social perspectives for a better use of this tool/mechanism, which adequately structuralized and integrated, creates propitious educational and professional performance/recycling conditions and a propeller instrument of research and extension activities. Among this work, it is suggested the aggregation of elements, which are complementary to the InfoAU discipline s reorganization, throughout a computerization s plan for the CAUs, extensive to the professional formation, generating a virtuous cycle in several activities of the academic, administrative and, research and extension s departments. Therefore, the InfoAU in the Brazilian CAUs context was analyzed; the main solutions and problems found were systemized; the possibilities of computer science s uses inside AU ware structuralized, InfoAU discipline s improvement plan was also defined, as well as strategies for the implementation of the computerization s plan for the CAUs, which would guarantee its maintenance in a continuity perspective
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Devido ao crescente aumento do uso de aeradores artificiais em sistema de cultivo de peixes e à carência de estudos nesta área, este trabalho avaliou a influência de um aerador tipo propeller diffuser (AR 120) nas variáveis bióticas e abióticas em um viveiro de engorda de peixe. Foram demarcados três pontos de coleta localizados a 5, 10 e 23 m de distância do aerador, durante 15 dias consecutivos, sendo 5 dias antes do uso do aerador, 5 dias com o aerador ligado e 5 dias com o aerador desligado. As variáveis limnológicas estudadas não apresentaram diferenças significativas (P > 0,05) entre os três pontos de coleta, porém, em relação ao uso do aerador, variáveis como temperatura, transparência, pH, oxigênio dissolvido, bicarbonato, CO2 livre, fósforo total, ortofosfato, amônia, nitrato e nitrito diferiram significativamente (P < 0,05) com a agitação mecânica da água. Já a condutividade, alcalinidade, CO2 total e clorofila a não apresentaram diferenças significativas (P > 0,05) com o uso do aerador. A comunidade fitoplanctônica sofreu influência direta do aerador (P < 0,05), dominada pelas Chlorophyta, representando mais de 70% do total de organismos presentes, seguidas das Cyanophyta e Chrysophyta, porém estas últimas tenderam a aumentar após o uso do aerador, uma vez que estes grupos se adaptam rapidamente às mudanças do ambiente.