12,138 research outputs found
Sealing Glasses for Titanium and Titanium Alloys
Glass compositions containing calcium oxide, alumina, boric oxide, strontium oxide and barium oxide in various mole % combinations were studied. These compositions are capable of forming stable glass to metal seals with titanium and titanium alloys for use as seals for battery headers
Automated Retrieval of Non-Engineering Domain Solutions to Engineering Problems
Organised by: Cranfield UniversityBiological inspiration for engineering design has occurred through a variety of techniques such as creation
and use of databases, keyword searches of biological information in natural-language format, prior
knowledge of biology, and chance observations of nature. This research focuses on utilizing the reconciled
Functional Basis function and flow terms to identify suitable biological inspiration for function based design.
The organized search provides two levels of results: (1) associated with verb function only and (2) narrowed
results associated with verb-noun (function-flow). A set of heuristics has been complied to promote efficient
searching using this technique. An example for creating smart flooring is also presented and discussed.Mori Seiki – The Machine Tool Compan
Telemedicine in Space Flight - Summary of a NASA Workshop
The Exploration Medical Capability Element of the Human Research Program at NASA Johnson Space Center hosted the Telemedicine Workshop in January 2011 to discuss the medical operational concept for a crewed mission to a near-Earth asteroid (NEA) and to identify areas for future work and collaboration. With the increased likelihood of a medical incident on a long duration exploration mission to a near-Earth asteroid, as well as the fact that there will likely be limited medical capabilities and resources available to diagnose and treat medical conditions, it is anticipated that a more structured use of telemedicine will become highly desirable. The workshop was convened to solicit expert opinion on current telemedicine practices and on medical care in remote environments. Workshop Objectives: The workshop brought together leaders in telemedicine and remote medicine from The University of Texas Medical Branch, Henry Ford Hospital, Ontario Telemedicine Network, U.S. Army Institute of Surgical Research, University of Miami, American Telemedicine Association, Doctors Without Borders, and the Pan American Health Organization. The primary objectives of the workshop were to document the medical operations concept for a crewed mission to a NEA, to determine gaps between current capabilities and the capabilities outlined in the operations concept, to identify research required to close these gaps, and to discuss potential collaborations with external-to-NASA organizations with similar challenges. Summary of Discussions and Conclusions: The discussions held during the workshop and the conclusions reached by the workshop participants were grouped into seven categories: Crew Medical Officers, Patient Area in Spacecraft, Training, Electronic Medical Records, Intelligent Care Systems, Consultation Protocols, Prophylactic Surgical Procedures, and Data Prioritization. The key points discussed under each category will be presented
Paleocene Cyclic Sedimentation in the Western North Atlantic, ODP Site 1051, Blake Nose
Upper Paleocene (zone CP8b) cyclic sediment from Ocean Drilling Program (ODP) Site 1051 on Blake Nose, western North Atlantic, alternates from white carbonate-rich to green carbonate-poor in response to precessional forcing. Compositional differences between the two bed types are minor: mineral and nannofossil composition of the beds vary subtly, but grain size of the terrigenous component and biogenic silica content remain constant. Iron content determined by sediment magnetic susceptibility and iron intensity determined by a core-scanning XRF correlates negatively with carbonate content and are higher in green beds. Kaolinite content of green beds is slightly higher as well. Green beds exhibit lower evenness values than white beds for nannofossil assemblages and are more dominated by the species Coccolithus. Dominance by Coccolithus indicates more mesotrophic conditions over Blake Nose during deposition of the green beds, which correlates with slightly higher iron and kaolinite contents.
The absence of change in terrigenous grain size and the absence of any indication of planktonic blooms indicate that there was a minor, most likely eolian, input of iron and kaolinite during deposition of the green beds. The source area was most likely northwest Africa, which supplied iron and kaolinite when source areas deflated under drier conditions. With this scenario, kaolinite is an indicator of drier climate and source area erosion, rather than the warmer and/or wetter conditions under which it forms in soils.
During precessional minima or perihelion summer (the opposite of our current configuration), there was an increased range of seasonal temperatures and an increase in the intensity of summer and winter monsoon circulation. As a consequence, there was more rainfall in northern Africa and drier conditions in the continental interiors at mid-latitudes. Green bed deposition occurred during precessional maxima when the North Atlantic was cooler, northwest Africa drier, and the eolian flux to the western North Atlantic slightly increased
Delivering Urban Wellbeing through Transformative Community Enterprise
(c) The Author/sChristchurch, New Zealan
Minor degree of hypohydration adversely influences cognition: a mediator analysis
Background: The assumption that small changes in hydration statusare readily compensated by homeostatic mechanisms has been littlestudied. In this study, the influence of hypohydration on cognition wasexamined.Objectives: We assessed whether a loss of ,1% of body mass dueto hypohydration adversely influenced cognition, and examined thepossible underlying mechanisms.Design: A total of 101 individuals were subjected to a temperature of308C for 4 h and randomly either did or did not consume 300 mLH2O during that period. Changes in body mass, urine osmolality,body temperature, and thirst were monitored. Episodic memory, focusedattention, mood, and the perceived difficulty of tasks weremeasured on 3 occasions. The data were analyzed with the use ofa regression-based approach whereby we looked for variables that mediatedthe influence of hypohydration on psychological functioning.Results: Drinking water improved memory and focused attention.In the short-term, thirst was associated with poorer memory. Later,a greater loss of body mass was associated with poorer memory andattention (mean loss: 0.72%). At 90 min, an increase in thirst wasassociated with a decline in subjective energy and increased anxietyand depression, effects that were reduced by drinking water. At180 min, subjects found the tests easier if they had consumed water.Conclusions: Drinking water was shown, for the first time to ourknowledge, to benefit cognitive functioning when there was a lossof ,1% body mass at levels that may occur during everydayliving. Establishing the variables that generate optimal fluid consumptionwill help to tailor individual advice, particularly in clinicalsituations
Stellar Encounters with Massive Star-Disk Systems
The dense, clustered environment in which massive stars form can lead to
interactions with neighboring stars. It has been hypothesized that collisions
and mergers may contribute to the growth of the most massive stars. In this
paper we extend the study of star-disk interactions to explore encounters
between a massive protostar and a less massive cluster sibling using the
publicly available SPH code GADGET-2. Collisions do not occur in the parameter
space studied, but the end state of many encounters is an eccentric binary with
a semi-major axis ~ 100 AU. Disk material is sometimes captured by the
impactor. Most encounters result in disruption and destruction of the initial
disk, and periodic torquing of the remnant disk. We consider the effect of the
changing orientation of the disk on an accretion driven jet, and the evolution
of the systems in the presence of on-going accretion from the parent core.Comment: 11 pages, 10 figures, accepted to Ap
Nominal Logic Programming
Nominal logic is an extension of first-order logic which provides a simple
foundation for formalizing and reasoning about abstract syntax modulo
consistent renaming of bound names (that is, alpha-equivalence). This article
investigates logic programming based on nominal logic. We describe some typical
nominal logic programs, and develop the model-theoretic, proof-theoretic, and
operational semantics of such programs. Besides being of interest for ensuring
the correct behavior of implementations, these results provide a rigorous
foundation for techniques for analysis and reasoning about nominal logic
programs, as we illustrate via examples.Comment: 46 pages; 19 page appendix; 13 figures. Revised journal submission as
of July 23, 200
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