1,245 research outputs found
Simplified analytical model for sound level prediction at shielded urban locations involving multiple diffraction and reflections
Apparatus analysis and preliminary design of low gravity porous solids experiment for STS Orbiter mid-deck
The apparatus analysis laboratory equipment design and fabrication and the preliminary design of the Combustion of Porous Solids Experiment for operation in the mid-deck area of the Shuttle are described. The apparatus analysis indicated that the mid-deck region of the STS was a feasible region of the Shuttle for operation. A sixteen tube concept was developed with tubes of 75 cm length and up to 5.6 cm accommodated. The experiment is viewed by IR sensors and a 16 mm camera. Laboratory equipment was designed and fabricated to test the parible injection, mixing and venting concepts. This equipment was delivered to NASA/LeRC. A preliminary design was made for the experiment based upon the apparatus analysis. The design incorporated results from the Phase ""O'' Safety Review. This design utilizes a closed tube concept in which the particles are stored, injected and burned with no coupling to the Shuttle environment. Drawings of the major components and an assembly are given. The electronics are described for the experiment. An equipment list is presented and an experiment weight estimate is determined. The mission operation requirements are outlined
Detection of Cracks Adjacent to Spotwelds by Radiography in Thin Stainless Steel Sheet
Radiographic detection of cracks adjacent to spotwelds in thin stainless steel shee
Blogging about Service-Learning Experiences
Presentation given at the SoTL Commons: A Conference for the Scholarship of Teaching and Learning. This project examines a year-long Honors First Year Experience course in Animal-Assisted Therapy, a course introducing students to the effects of therapy animals on various populations with various conditions in multiple settings. From Fall 2012 to Spring 2013, students were required to participate in service-learning activities with either the local chapter of Therapy Dogs International or the local therapeutic horseback riding program and to blog about their experiences. For their blogs, students had to describe their experiences, their reactions to the experiences, how the experiences related to the course, and any questions or concerns that arose. Qualitative analyses of studentsâ blogs were conducted, using a Grounded Theory approach. Results revealed that students could identify the key role therapy animals can play in enhancing rehabilitation and development. Additionally, service-learning augmented the studentsâ knowledge of, awareness of, and interest in animal-assisted therapy and showed how animals themselves appear to act as crucial learning instruments in certain settings. Session objectives include introducing attendees to service-learning and exploring the lurking implication that animals can enhance learning environments. Attendees will learn how service-learning has the potential to add to all disciplines and will be challenged to think of ways to implement animals into student learning
Level structures of ²â´Na observed in the total neutron cross section of sodium from 300 to 900 keV
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Aerial and surface rivers: Downwind impacts on water availability from land use changes in Amazonia
The abundant evapotranspiration provided by the Amazon forests is an important component of the hydrological cycle, both regionally and globally. Since the last century, deforestation and expanding agricultural activities have been changing the ecosystem and its provision of moisture to the atmosphere. However, it remains uncertain how the ongoing land use change will influence rainfall, runoff, and water availability as findings from previous studies differ. Using moisture tracking experiments based on observational data, we provide a spatially detailed analysis recognizing potential teleconnection between source and sink regions of atmospheric moisture. We apply land use scenarios in upwind moisture sources and quantify the corresponding rainfall and runoff changes in downwind moisture sinks. We find spatially varying responses of water regimes to land use changes, which may explain the diverse results from previous studies. Parts of the Peruvian Amazon and western Bolivia are identified as the sink areas most sensitive to land use change in the Amazon and we highlight the current water stress by Amazonian land use change on these areas in terms of the water availability. Furthermore, we also identify the influential source areas where land use change may considerably reduce a given target sink's water reception (from our example of the Ucayali River basin outlet, rainfall by 5â12ÄâŹ% and runoff by 19â50ÄâŹ% according to scenarios). Sensitive sinks and influential sources are therefore suggested as hotspots for achieving sustainable landâwater management
Comparison of storm damage functions and their performance
Winter storms are the most costly natural hazard for European residential
property. We compare four distinct storm damage functions with respect to
their forecast accuracy and variability, with particular regard to the most
severe winter storms. The analysis focuses on daily loss estimates under
differing spatial aggregation, ranging from district to country level. We
discuss the broad and heavily skewed distribution of insured losses posing
difficulties for both the calibration and the evaluation of damage functions.
From theoretical considerations, we provide a synthesis between the
frequently discussed cubic windâdamage relationship and recent studies that
report much steeper damage functions for European winter storms. The
performance of the storm loss models is evaluated for two sources of wind
gust data, direct observations by the German Weather Service and ERA-Interim
reanalysis data. While the choice of gust data has little impact on the
evaluation of German storm loss, spatially resolved coefficients of variation
reveal dependence between model and data choice. The comparison shows that
the probabilistic models by Heneka et al. (2006) and Prahl et al.
(2012) both provide accurate loss predictions for moderate to extreme losses, with
generally small coefficients of variation. We favour the latter model in
terms of model applicability. Application of the versatile deterministic
model by Klawa and Ulbrich (2003) should be restricted to extreme loss, for which it
shows the least bias and errors comparable to the probabilistic model by
Prahl et al. (2012)
Aerial and surface rivers: downwind impacts on water availability from land use changes in Amazonia
The abundant evapotranspiration provided by the Amazon forests is an important component of the hydrological cycle, both regionally and globally. Since the last century, deforestation and expanding agricultural activities have been changing the ecosystem and its provision of moisture to the atmosphere. However, it remains uncertain how the ongoing land use change will influence rainfall, runoff, and water availability as findings from previous studies differ. Using moisture tracking experiments based on observational data, we provide a spatially detailed analysis recognizing potential teleconnection between source and sink regions of atmospheric moisture. We apply land use scenarios in upwind moisture sources and quantify the corresponding rainfall and runoff changes in downwind moisture sinks. We find spatially varying responses of water regimes to land use changes, which may explain the diverse results from previous studies. Parts of the Peruvian Amazon and western Bolivia are identified as the sink areas most sensitive to land use change in the Amazon and we highlight the current water stress by Amazonian land use change on these areas in terms of the water availability. Furthermore, we also identify the influential source areas where land use change may considerably reduce a given target sink's water reception (from our example of the Ucayali River basin outlet, rainfall by 5â12ÄâŹ% and runoff by 19â50ÄâŹ% according to scenarios). Sensitive sinks and influential sources are therefore suggested as hotspots for achieving sustainable landâwater management
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