924 resultados para Emerging Technologies
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The Alliance for Coastal Technologies (ACT) Workshop entitled "Technologies for Measuring Currents in Coastal Environments" was held in Portland, Maine, October 26-28, 2005, with sponsorship by the Gulf of Maine Ocean Observing System (GoMOOS), an ACT partner organization. The primary goals of the event were to summarize recent trends in nearshore research and management applications for current meter technologies, identify how current meters can assist coastal managers to fulfill their regulatory and management objectives, and to recommend actions to overcome barriers to use of the technologies. The workshop was attended by 25 participants representing state and federal environmental management agencies, manufacturers of current meter technologies, and researchers from academic institutions and private industry. Common themes that were discussed during the workshop included 1) advantages and limitations of existing current measuring equipment, 2) reliability and ease of use with each instrument type, 3) data decoding and interpretation procedures, and 4) mechanisms to facilitate better training and guidance to a broad user group. Seven key recommendations, which were ranked in order of importance during the last day of the workshop are listed below. 1. Forums should be developed to facilitate the exchange of information among users and industry: a) On-line forums that not only provide information on specific instruments and technologies, but also provide an avenue for the exchange of user experiences with various instruments (i.e. problems encountered, cautions, tips, advantages, etc). (see References for manufacturer websites with links to application and technical forums at end of report) b) Regional training/meetings for operational managers to exchange ideas on methods for measuring currents and evaluating data. c) Organize mini-meetings or tutorial sessions within larger conference venues. 2. A committee of major stakeholders should be convened to develop common standards (similar to the Institute of Electrical and Electronics Engineers (IEEE) committee) that enable users to switch sensors without losing software or display capabilities. (pdf contains 28 pages)
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The Alliance for Coastal Technologies (ACT) Partner University of Michigan convened a workshop on the Applications of Drifting Buoy Technologies for Coastal Watershed and Ecosystem Modeling in Ann Arbor, Michigan on June 5 to 7,2005. The objectives of the workshop were to: (1) educate potential users (managers and scientists) about the current capabilities and uses of drifting buoy technologies; (2) provide an opportunity for users (managers and scientists) to experience first hand the deployment and retrieval of various drifting buoys, as well as experience the capabilities of the buoys' technologies; (3) engage manufacturers with scientists and managers in discussions on drifting buoys' capabilities and their requirements to promote further applications of these systems; (4) promote a dialogue about realistic advantages and limitations of current drifting buoy technologies; and (5) develop a set of key recommendations for advancing both the capabilities and uses of drifting buoy technologies for coastal watershed and ecosystem modeling. To achieve these goals, representatives from research, academia, industry, and resource management were invited to participate in this workshop. Attendees obtained "hands on" experience as they participated in the deployment and retrieval of various drifting buoy systems on Big Portage Lake, a 644 acre lake northwest of Ann Arbor. Working groups then convened for discussions on current commercial usages and environmental monitoring approaches including; user requirements for drifting buoys, current status of drifting buoy systems and enabling technologies, and the challenges and strategies for bringing new drifting buoys "on-line". The following general recommendations were made to: 1). organize a testing program of drifting buoys for marketing their capabilities to resource managers and users. 2). develop a fact sheet to highlight the utility of drifting buoys. 3). facilitate technology transfer for advancements in drifter buoys that may be occurring through military funding and development in order to enhance their technical capability for environmental applications. (pdf contains 18 pages)
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(pdf contains 23 pages)
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Technology generation and dissemination are important components of rural transformation programmes. Nigerian fisheries sub-sector is still hampered by low productivity (especially in aquaculture) and low output (capture fisheries and post-harvest technologies). Research institutions and the Universities have made efforts in developing improved technologies to find solution to these problems, yet the level of adoption of the technologies remain low. This is due to a combination of various factors among which are faulty agricultural policies; institutional framework and unfavourable socio-economic environment. Niger State plays an important role in production in Nigeria and host the only research institute with the mandate in inland fisheries. It is important therefore to know the effectiveness of various extension approaches used in disseminating the technologies developed and their impact on adopters. Forty fishers were randomly selected in Shiroro L.G.A. of the Niger State and interviewed. The study probed into their socio-economic characteristics, traditional practices, extent of awareness and adoption for fisheries technologies and the effectiveness and impact of various approaches used by the extension organizations to disseminate the technologies. The results show that the economically active age group of the fishers was in the range of 20-50 years (87.5%). Males (95%) dominate the fisher population. 47.5% of the respondents have average household size of 6-10 and 57.5% were below primary school in educational attainment. Only 57.5% belonged to cooperative societies, while 90.0% of the fishers have no access to credit other than personal finance. Majority of fish-farmers (60%) operate at homestead level with pond size less than 50 square meter, stock under polyculture fishing methods are at subsistence level, while 67.5% of processors use mud-oven to cure, by smoking, freshly caught fish. Disseminated aquaculture technologies have low level of awareness (5-20%) and adoption (2.5-22.5%). For capture fisheries and post-harvest technologies awareness levels of 47.5-72.5% and adoption levels of 27.5-50.0% were recorded. Method demonstration (87.5%), result demonstration (75.0%) and field days (47.5%) are the major approaches used by the ADP. Respondents were of the opinion that method demonstration (65%), result demonstration (57.5%) and field day (30.0%) are effective. 62.5% of respondents had enhanced income due impact of extension activities
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Among the branches of astronomy, radio astronomy is unique in that it spans the largest portion of the electromagnetic spectrum, e.g., from about 10 MHz to 300 GHz. On the other hand, due to scientific priorities as well as technological limitations, radio astronomy receivers have traditionally covered only about an octave bandwidth. This approach of "one specialized receiver for one primary science goal" is, however, not only becoming too expensive for next-generation radio telescopes comprising thousands of small antennas, but also is inadequate to answer some of the scientific questions of today which require simultaneous coverage of very large bandwidths.
This thesis presents significant improvements on the state of the art of two key receiver components in pursuit of decade-bandwidth radio astronomy: 1) reflector feed antennas; 2) low-noise amplifiers on compound-semiconductor technologies. The first part of this thesis introduces the quadruple-ridged flared horn, a flexible, dual linear-polarization reflector feed antenna that achieves 5:1-7:1 frequency bandwidths while maintaining near-constant beamwidth. The horn is unique in that it is the only wideband feed antenna suitable for radio astronomy that: 1) can be designed to have nominal 10 dB beamwidth between 30 and 150 degrees; 2) requires one single-ended 50 Ohm low-noise amplifier per polarization. Design, analysis, and measurements of several quad-ridged horns are presented to demonstrate its feasibility and flexibility.
The second part of the thesis focuses on modeling and measurements of discrete high-electron mobility transistors (HEMTs) and their applications in wideband, extremely low-noise amplifiers. The transistors and microwave monolithic integrated circuit low-noise amplifiers described herein have been fabricated on two state-of-the-art HEMT processes: 1) 35 nm indium phosphide; 2) 70 nm gallium arsenide. DC and microwave performance of transistors from both processes at room and cryogenic temperatures are included, as well as first-reported measurements of detailed noise characterization of the sub-micron HEMTs at both temperatures. Design and measurements of two low-noise amplifiers covering 1--20 and 8—50 GHz fabricated on both processes are also provided, which show that the 1--20 GHz amplifier improves the state of the art in cryogenic noise and bandwidth, while the 8--50 GHz amplifier achieves noise performance only slightly worse than the best published results but does so with nearly a decade bandwidth.
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In recent years coastal resource management has begun to stand as its own discipline. Its multidisciplinary nature gives it access to theory situated in each of the diverse fields which it may encompass, yet management practices often revert to the primary field of the manager. There is a lack of a common set of “coastal” theory from which managers can draw. Seven resource-related issues with which coastal area managers must contend include: coastal habitat conservation, traditional maritime communities and economies, strong development and use pressures, adaptation to sea level rise and climate change, landscape sustainability and resilience, coastal hazards, and emerging energy technologies. The complexity and range of human and environmental interactions at the coast suggest a strong need for a common body of coastal management theory which managers would do well to understand generally. Planning theory, which itself is a synthesis of concepts from multiple fields, contains ideas generally valuable to coastal management. Planning theory can not only provide an example of how to develop a multi- or transdisciplinary set of theory, but may also provide actual theoretical foundation for a coastal theory. In particular we discuss five concepts in the planning theory discourse and present their utility for coastal resource managers. These include “wicked” problems, ecological planning, the epistemology of knowledge communities, the role of the planner/ manager, and collaborative planning. While these theories are known and familiar to some professionals working at the coast, we argue that there is a need for broader understanding amongst the various specialists working in the increasingly identifiable field of coastal resource management. (PDF contains 4 pages)
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Several technologies have been disseminated to the rural populace of which few were adoptable while others were above their reaches. The adoption-rejection behaviour of the people of Monai community formed the basis for this study. Twenty women fish processors were interviewed using standard questionnaire. The study discovered that the women fish processors used the new introduced Better Life Programme Banda in rotation for even coverage. The use of new Banda has a positive effect on the quantity of fish processed and income. Additional two basins were processed on weekly basis with an income of N1,000.00 over the previous processing technology. No women processor however had the new Banda on individual basis for cost. Hence rural people adopt a technology that is cheap and simple but conforming to their traditional practices and values. Therefore any innovation intended for the rural populace should take cognizance of their socio-economic and cultural factors
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Motivated by recent MSL results where the ablation rate of the PICA heatshield was over-predicted, and staying true to the objectives outlined in the NASA Space Technology Roadmaps and Priorities report, this work focuses on advancing EDL technologies for future space missions.
Due to the difficulties in performing flight tests in the hypervelocity regime, a new ground testing facility called the vertical expansion tunnel is proposed. The adverse effects from secondary diaphragm rupture in an expansion tunnel may be reduced or eliminated by orienting the tunnel vertically, matching the test gas pressure and the accelerator gas pressure, and initially separating the test gas from the accelerator gas by density stratification. If some sacrifice of the reservoir conditions can be made, the VET can be utilized in hypervelocity ground testing, without the problems associated with secondary diaphragm rupture.
The performance of different constraints for the Rate-Controlled Constrained-Equilibrium (RCCE) method is investigated in the context of modeling reacting flows characteristic to ground testing facilities, and re-entry conditions. The effectiveness of different constraints are isolated, and new constraints previously unmentioned in the literature are introduced. Three main benefits from the RCCE method were determined: 1) the reduction in number of equations that need to be solved to model a reacting flow; 2) the reduction in stiffness of the system of equations needed to be solved; and 3) the ability to tabulate chemical properties as a function of a constraint once, prior to running a simulation, along with the ability to use the same table for multiple simulations.
Finally, published physical properties of PICA are compiled, and the composition of the pyrolysis gases that form at high temperatures internal to a heatshield is investigated. A necessary link between the composition of the solid resin, and the composition of the pyrolysis gases created is provided. This link, combined with a detailed investigation into a reacting pyrolysis gas mixture, allows a much needed consistent, and thorough description of many of the physical phenomena occurring in a PICA heatshield, and their implications, to be presented.
Through the use of computational fluid mechanics and computational chemistry methods, significant contributions have been made to advancing ground testing facilities, computational methods for reacting flows, and ablation modeling.