2,395 research outputs found
Emission processes and dynamics of hot gases in astrophysics
A detailed model was developed for Kepler's supernova remnant (SNR). Observations of the SNR revealed a strong interaction with the surrounding circumstellar medium, which was studied through both analytical and numerical calculations. Effects were studied of electron thermal conduction on the structure of radiative interstellar shock waves. An explanation is sought for the observed line emission from metal rich ejecta in SNR, incorporating atomic data. Light echoes around SN 1987A was also studied. Analysis of infrared and scattered circumstellar light echoes was accomplished with early observations to set limits on the mass of circumstellar dust. Work was completed on the emission from heavy element gas ejected in the supernova explosion of massive stars. It was assumed that a radioactive energy source was present and calculated the detailed heating and ionization of the gas. The evolution was studied of SNR in the very high pressure environment of a starburst galaxy
Investigation of aerothermodynamics and optical radiation in the AFE hypersonic flow field
Research for the radiation experiments on the Aeroassist Flight Experiment (AFE) was performed to obtain a data base for development of engineering requirements for aerobrakes. Due to funding restrictions, the necessary Aerobrake design data were obtained from ground based experiments, specifically arc-jet wind tunnels. Except for the instrument windows, final development of the AFE radiometers was completed. Window definition included several designs to be flight validated in arc-jets. This work was completed, and successful designs have evolved which will yield full scientific return from the flight experiment. The theoretical work includes final code development to describe the spacecraft environment to support instrument definition, optical radiation codes that operate at significantly improved speeds, and calculation of radiation forebody loads and effects on experiment objectives for varying AFE weights and trajectories. Furthermore, radiant flux vectors at the AFE base were predicted to be used for afterbody instrument definition. The Vacuum Ultraviolet Experiment for the Arc-Jet was completed, and arc-jet experiment conditions and experiment objectives were refined to incorporate the most current thinking. Ballistic range experiments were completed. Several shadowgraphs indicating corner turning angles and waviness structures were obtained, and the results were used to estimate the compression region location for the AFE flight. The waviness measured has helped to model the temporal variations of wake radiation for purposes of defining radiometers to measure the energy content of wake dynamics
Queensland Cloud Seeding Research Program - QCSRP
Due to increasing demands on water supplies and the negative effects of climate variability and change, south east Queensland frequently suffers severe water shortages. Based on recent scientific advances in cloud seeding techniques, a research project was commissioned by the Queensland Government in 2007. The aim of the project is to investigate the potential for cloud seeding technologies in the Somerset and Wivenhoe catchments of south east Queensland as part of the solution to the regions water shortages.
The ongoing project has involved over 40 dedicated personnel, research aircraft and the Bureau of Meteorology’s advanced weather radar facilities located at Redbank Plains and Mt Stapylton. During the first season, which took place from December 2007 to March 2008, randomised seeding experiments were carried out to quantify the effect of hygroscopic seeding using pyrotechnic flares which release small particles of potassium chloride at the base of convective clouds (Bruintjes, 1999).
Research into the climatological characteristics of precipitation in the target area including the frequency of cumulus clouds suitable for seeding has also been undertaken. The CP2 polarimetric radar at Redbank Plains and the local Bureau of Meteorology radar network are used to evaluate the effects of seeding on precipitation flux, duration and storm dynamics including secondary cell initiation. Radar estimates of precipitation are calibrated using a ground-based video disdrometer. Cloud microphysical data was collected by the research aircraft which was equipped with over 20 microphysical recording instruments.
The program has been highly successful in providing cloud statistical data for the target area in addition to evaluating aircraft based hygroscopic seeding activities. Sub-tropical maritime warm shallow convective clouds rather than the more potentially suitable deep convective cloud systems were a feature of the first seasons weather. Although positive trends in terms of increased cell duration are apparent in the data, the number of randomised cases (27) is not sufficient to draw statistically significant conclusions regarding the efficacy of hygroscopic seeding of these clouds. This important scientific research program has continued into the 2008-2009 season. Based on results to date there is strong incentive for further research into the hygroscopic seeding of deep convective clouds throughout south east Queensland and its potential for inland catchments
Planetary entry experiments
The final report summarizes the results from three research areas: (1) window design for the radiometric measurement of the forebody radiative heating experienced by atmospheric entry spaceraft; (2) survey of the current understanding of chemical species on selected solar system bodies and assess the importance of measurements with regard to vehicle environment and with regard to understanding of planetary atmospheres with emphasis on Venus, Mars, and Titan; and (3) measure and analyze the radiation (VUV to near-IR) from the shock heated gas cap of a blunt body in an Ames arc Jet wind-tunnel facility
Venusian atmospheric equilibrium chemistry at the Pioneer Venus anomalous event altitude
No convincing explanation for the anomalous behavior of the Atmospheric Structure Experiment temperature sensors at approximately 13 km altitude has been found. It occurred on all of the widely-spaced probes, in a similar fashion. A preliminary effort has been made to determine atmospheric chemical species which might be present at 13 km. The purpose of this effort is to initiate suggestions of possible chemical interactions and to explore the effects of the presence of possible metal reactants including condensation. Equilibrium fractions of chemical species were calculated at a variety of conditions. Baseline calculations were made for the altitudes near 13 km. For comparison calculations were also made at 13 km but with the introduction of plausible metal atoms
Design in the Real world
Social design highlights design-based practices towards collective and social ends rather than predominately commercial or consumer-oriented objectives. In this paper we share staff and students experiences of participating in an interdisciplinary approach to social design and describe the key learning that arose from the implementation of a pioneering approach to the teaching of social design practice on the MA/MFA Design Programme at Sheffield Hallam University.
Taking the conference theme holistically this paper highlights the values of situating learning beyond the classroom in real-world contexts. Holism here relates to the recognition that learning is socially situated, that it draws on the individual strengths and resources students bring and that by involving practitioners from different specialisms, learning has the potential to bring about real-world transformation and change beyond the boundaries of the subject discipline.
The authors believe that social design has a place in design education as threats including precarious economies, social and financial inequities, global warming, war and mass migration are real-world issues impacting on world citizens and the planet. Opening up the right forums for discussion and experimentation, including the right mix of skills and knowledge to enrich discussion needs careful consideration and facilitation. Our initial work focused on placing social design within a module and employing cross-disciplinary and interdisciplinary working and learning. Our current projects widen the learning experience taking place over a year-long period with dual entry and multiple points. This work includes the local City Council, city residents and our DeSIS Lab.
Keywords: Holism, social design, student engagement
Getting into the thick (and thin) of it
The heart is a highly regulated system in which a combination of mechanisms work together to match cardiac output to the needs of the body. Loss of this regulation characterizes many cardiomyopathies, where muscle is either hypo- or hypercontractile. For many years, x-ray diffraction has been used to study the structural basis of myofilament length-dependent activation..
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