746 research outputs found
Evolving Our Evaluation of Lighting Environments Project
Imagine you are an astronaut on their 100th day of your three year exploration mission. During your daily routine to the small hygiene compartment of the spacecraft, you realize that no matter what you do, your body blocks the light from the lamp. You can clearly see your hands or your toes but not both! What were those design engineers thinking! It would have been nice if they could have made the walls glow instead! The reason the designers were not more innovative is that their interpretation of the system lighting requirements didn't allow them to be so! Currently, our interior spacecraft lighting standards and requirements are written around the concept of a quantity of light illuminating a spacecraft surface. The natural interpretation for the engineer is that a lamp that throws light to the surface is required. Because of certification costs, only one lamp is designed and small rooms can wind up with lamps that may be inappropriate for the room architecture. The advances in solid state light emitting technologies and optics for lighting and visual communication necessitates the evaluation of how NASA envisions spacecraft lighting architectures and how NASA uses industry standards for the design and evaluation of lighting system. Current NASA lighting standards and requirements for existing architectures focus on the separate ability of a lighting system to throw light against a surface or the ability of a display system to provide the appropriate visual contrast. Realization that these systems can be integrated is not realized. The result is that the systems are developed independent from one another and potential efficiencies that could be realized from borrowing from the concept of one technology and applying it for the purpose of the other does not occur. This project investigated the possibility of incorporating large luminous surface lamps as an alternative or supplement to overhead lighting. We identified existing industry standards for architectural luminous or brightness uniformity as part of a lighting system definition. The efficiency of the surface lighting technology was evaluated for uniformity and power consumption. Finally, the team investigated possible performance savings if the walls were made to glow via a self luminous surface system instead of creating brightness by use of direct lighting of a highly reflective diffuse surface
Individual and demographic consequences of reduced body condition following repeated exposure to high temperatures
Although the lethal consequences of extreme heat are increasingly reported in the literature, the fitness costs of exposure to sublethal high air temperatures, typically identified in the 30â40°C range, are poorly understood. We examine the effect of high (â„35°C) daily maxima on body condition of a semiarid population of White-plumed Honeyeaters, Ptilotula penicillatus, monitored between 1986 and 2012. During this 26-yr period, temperature has risen, on average, by 0.06°C each year at the site, the frequency of days with thermal maxima â„35°C has increased and rainfall has declined. Exposure to high temperatures affected body condition of White-plumed Honeyeaters, but only in low-rainfall conditions. There was no effect of a single day of exposure to temperatures â„35°C but repeated exposure was associated with reduced body condition: 3.0% reduction in body mass per day of exposure. Rainfall in the previous 30 d ameliorated these effects, with reduced condition evident only in dry conditions. Heat-exposed males with reduced body condition were less likely to be recaptured at the start of the following spring; they presumably died. Heat-exposed females, regardless of body condition, showed lower survival than exposed males, possibly due to their smaller body mass. The higher mortality of females and smaller males exposed to temperatures â„35°C may have contributed to the increase in mean body size of this population over 23 years. Annual survival declined across time concomitant with increasing frequency of days â„35°C and decreasing rainfall. Our study is one of few to identify a proximate cause of climate change related mortality, and associated long-term demographic consequence. Our results have broad implications for avian communities living in arid and semiarid regions of Australia, and other mid-latitudes regions where daily maximum temperatures already approach physiological limits in regions affected by both decreased precipitation and warming
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Climate-driven changes in body condition
Although the lethal consequences of extreme heat are increasingly reported in the literature, the fitness costs of exposure to sub-lethal high air temperatures, typically identified in the 30- 40°C range, are poorly understood. We examine the effect of high (â„35°C) daily maxima on body condition of a semi-arid population of white-plumed honeyeaters Ptilotula penicillatus monitored between 1986 and 2012. During this 26 year period temperature has risen, on average, by 0.06°C each year at the site, the frequency of days with thermal maxima â„35°C has increased and rainfall has declined. Exposure to high temperatures affected body condition of white-plumed honeyeaters, but only in low rainfall conditions. There was no effect of a single day of exposure to temperatures â„35°C but repeated exposure was associated with reduced body condition: 3.0% reduction in body mass per day of exposure. Rainfall in the previous 30 days ameliorated these effects, with reduced condition evident only in dry conditions. Heat-exposed males with reduced body condition were less likely to be recaptured at the start of the following spring; they presumably died. Heat-exposed females, regardless of body condition, showed lower survival than exposed males, possibly due to their smaller body mass. The higher mortality of females and smaller males exposed to temperatures â„35°C may have contributed to the increase in mean body size of this population over 23 years. Annual survival declined across time concomitant with increasing frequency of days â„35°C and decreasing rainfall. Our study is one of few to identify a proximate cause of climate change related mortality, and associated long-term demographic consequence. Our results have broad implications for avian communities living in arid and semi-arid regions of Australia, and other mid-latitudes regions where daily maximum temperatures already approach physiological limits in regions affected by both decreased precipitation and warming.The work was conducted under permits SL100167 and SL100825 issued by the Office of Environment and Heritage, National Parks and Wildlife Service (NPWS), NSW and bands were supplied by the Australian Bird and Bat Banding Scheme. We thank the many volunteer banders and NPWS staff for support. Jim Thompson provided initial statistical advice and Loeske Kruuk, Peter Marsack and Katherine Selwood useful discussion or comments on the manuscript. The work received funding from the Norman Wettenhall Foundation and the Australian Research Council (ARC, Discovery grant DP120102651). Sutherland is funded by Arcadia, Peters by an ARC Future Fellowship (FT110100505) and Amano by a Marie Curie International Incoming Fellowship.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1890/15-064
Community Seismic Network
The article describes the design of the Community Seismic Network, which is a dense open seismic network based on low cost sensors. The inputs are from sensors hosted by volunteers from the community by direct connection to their personal computers, or through sensors built into mobile devices. The server is cloud-based for robustness and to dynamically handle the load of impulsive earthquake events. The main product of the network is a map of peak acceleration, delivered within seconds of the ground shaking. The lateral variations in the level of shaking will be valuable to first responders, and the waveform information from a dense network will allow detailed mapping of the rupture process. Sensors in buildings may be useful for monitoring the state-of-health of the structure after major shaking
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