Performance testing of extremity dosimeters, Study 2

International Nuclear Information System (INIS)

Harty, R.; Reece, W.D.; Hooker, C.D.

1990-04-01

The Health Physics Society Standards Committee (HPSSC) Working Group on Performance Testing of Extremity Dosimeters has issued a draft of a proposed standard for extremity dosimeters. The draft standard proposes methods to be used for testing dosimetry systems that determine occupational radiation dose to the extremities and the performance criterion used to determine compliance with the standard. Pacific Northwest Laboratory (PNL) has conducted two separate evaluations of the performance of extremity dosimeter processors to determine the appropriateness of the draft standard, as well as to obtain information regarding the performance of extremity dosimeters. Based on the information obtained during the facility visits and the results obtained from the performance testing, it was recommended that changes be made to ensure that the draft standard is appropriate for extremity dosimeters. The changes include: subdividing the mixture category and the beta particle category; eliminating the neutron category until appropriate flux-to-dose equivalent conversion factors are derived; and changing the tolerance level for the performance criterion to provide consistency with the performance criterion for whole body dosimeters, and to avoid making the draft standard overly difficult for processors of extremity dosimeters to pass. 20 refs., 10 figs., 6 tabs

Qualification of Fiber Optic Cables for Martian Extreme Temperature Environments

Science.gov (United States)

Ramesham, Rajeshuni; Lindensmith, Christian A.; Roberts, William T.; Rainen, Richard A.

2011-01-01

Means have been developed for enabling fiber optic cables of the Laser Induced Breakdown Spectrometer instrument to survive ground operations plus the nominal 670 Martian conditions that include Martian summer and winter seasons. The purpose of this development was to validate the use of the rover external fiber optic cabling of ChemCam for space applications under the extreme thermal environments to be encountered during the Mars Science Laboratory (MSL) mission. Flight-representative fiber optic cables were subjected to extreme temperature thermal cycling of the same diurnal depth (or delta T) as expected in flight, but for three times the expected number of in-flight thermal cycles. The survivability of fiber optic cables was tested for 600 cumulative thermal cycles from -130 to +15 C to cover the winter season, and another 1,410 cumulative cycles from -105 to +40 C to cover the summer season. This test satisfies the required 3 times the design margin that is a total of 2,010 thermal cycles (670 x 3). This development test included functional optical transmission tests during the course of the test. Transmission of the fiber optic cables was performed prior to and after 1,288 thermal cycles and 2,010 thermal cycles. No significant changes in transmission were observed on either of the two representative fiber cables subject through the 3X MSL mission life that is 2,010 thermal cycles.

Heatshield for Extreme Entry Environment Technology (HEEET) Development and Maturation Status for NF Missions

Science.gov (United States)

Ellerby, D.; Blosser, M.; Boghozian, T.; Chavez-Garcia, J.; Chinnapongse, R.; Fowler, M.; Gage, P.; Gasch, M.; Gonzales, G.; Hamm, K.;

Flexible Electronics-Based Transformers for Extreme Environments

Science.gov (United States)

Quadrelli, Marco B.; Stoica, Adrian; Ingham, Michel; Thakur, Anubhav

2015-01-01

This paper provides a survey of the use of modular multifunctional systems, called Flexible Transformers, to facilitate the exploration of extreme and previously inaccessible environments. A novel dynamics and control model of a modular algorithm for assembly, folding, and unfolding of these innovative structural systems is also described, together with the control model and the simulation results.

Biofilms and planktonic cells of Deinococcus geothermalis in extreme environments

Science.gov (United States)

Panitz, Corinna; Reitz, Guenther; Rabbow, Elke; Rettberg, Petra; Flemming, Hans-Curt; Wingender, Jost; Froesler, Jan

radiation. D. geothermalis besides others, like co-cultures of Halomonas muralis and Halococcus morrhuae, Bacillus horneckiae, Chroococcidiopsis CCMEE 029 and Streptomyces + Polaromonas and Arthrobacter strains from volcanic rocks, was involved in the several preparatory test runs at the Planetary and Space Simulation facilities at the German Aerospace Center in Cologne. Results of the already carried out EVTs (Experiment Verification Test) and the SVT (Science verification test) as EXPOSE-R2 mission pre-paration tests, where investigated parameters like dehydration, temperature extremes, extraterrestrial UV radiation, simulated Martian atmosphere, and a Mars-like UV climate were tested individually as well as in combination will be presented. Following exposure to the parameters listed above, the survival of both biofilms and planktonic cells of D. geothermalis was assessed in terms of (i) culturability by colony counts on R2A medium, (ii) membrane integrity by using the Live/Dead differential staining kit, (iii) ATP content by using a commercial luminometric assay, and (iv) the presence of 16S rRNA by fluorescence in situ hybridization. So far, the results suggest that Deinococcus geothermalis remains viable in the desiccated state over weeks to months, whereas culturability, intracellular ATP levels, and membrane integrity were preserved in biofilm cells at a significantly higher level than in planktonic cells. Furthermore, cells of both sample types were able to survive simulated space and Martian conditions and showed high resistance after irradiation with monochromatic and polychromatic UV. The results will contribute to the fundamental understanding of the opportunities and limitations of viability of microorganisms organized in biofilms or as planktonic cells under the extreme environ-mental conditions of space or other planets.

EXTREMELY METAL-POOR GALAXIES: THE ENVIRONMENT

Energy Technology Data Exchange (ETDEWEB)

Filho, M. E. [Universidad de Las Palmas de Gran Canaria–Universidad de La Laguna, CIE Canarias: Tri-Continental Atlantic Campus, Canary Islands (Spain); Almeida, J. Sánchez; Muñoz-Tuñón, C. [Instituto Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain); Nuza, S. E.; Kitaura, F.; Heß, S., E-mail: mfilho@astro.up.pt [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany)

2015-04-01

We have analyzed bibliographical observational data and theoretical predictions, in order to probe the environment in which extremely metal-poor dwarf galaxies (XMPs) reside. We have assessed the H i component and its relation to the optical galaxy, the cosmic web type (voids, sheets, filaments and knots), the overdensity parameter and analyzed the nearest galaxy neighbors. The aim is to understand the role of interactions and cosmological accretion flows in the XMP observational properties, particularly the triggering and feeding of the star formation. We find that XMPs behave similarly to Blue Compact Dwarfs; they preferably populate low-density environments in the local universe: ∼60% occupy underdense regions, and ∼75% reside in voids and sheets. This is more extreme than the distribution of irregular galaxies, and in contrast to those regions preferred by elliptical galaxies (knots and filaments). We further find results consistent with previous observations; while the environment does determine the fraction of a certain galaxy type, it does not determine the overall observational properties. With the exception of five documented cases (four sources with companions and one recent merger), XMPs do not generally show signatures of major mergers and interactions; we find only one XMP with a companion galaxy within a distance of 100 kpc, and the H i gas in XMPs is typically well-behaved, demonstrating asymmetries mostly in the outskirts. We conclude that metal-poor accretion flows may be driving the XMP evolution. Such cosmological accretion could explain all the major XMP observational properties: isolation, lack of interaction/merger signatures, asymmetric optical morphology, large amounts of unsettled, metal-poor H i gas, metallicity inhomogeneities, and large specific star formation.

Mitochondrial Plasticity With Exercise Training and Extreme Environments

DEFF Research Database (Denmark)

Boushel, Robert; Lundby, Carsten; Qvortrup, Klaus

2014-01-01

Mitochondria form a reticulum in skeletal muscle. Exercise training stimulates mitochondrial biogenesis, yet an emerging hypothesis is that training also induces qualitative regulatory changes. Substrate oxidation, oxygen affinity and biochemical coupling efficiency may be differentially regulated...... with training and exposure to extreme environments. Threshold training doses inducing mitochondrial up-regulation remain to be elucidated considering fitness level. SUMMARY: Muscle mitochondrial are responsive to training and environment, yet thresholds for volume vs. regulatory changes and their physiological...

TransFormers for Ensuring Long-Term Operations in Lunar Extreme Environments

Science.gov (United States)

Mantovani, J. G.; Stoica, A.; Alkalai, L.; Wilcox, B.; Quadrelli, M.

2016-01-01

"Surviving Extreme Space Environments" (EE) is one of NASA's Space Technology Grand Challenges. Power generation and thermal control are the key survival ingredients that allow a robotic explorer to cope with the EE using resources available to it, for example, by harvesting the local solar energy or by utilizing an onboard radioisotope thermoelectric generator (RTG). TransFormers (TFs) are a new technology concept designed to transform a localized area within a harsh extreme environment into a survivable micro-environment by projecting energy to the precise location where robots or humans operate. For example, TFs placed at a location on the rim of Shackleton Crater, which is illuminated by solar radiation for most of the year, would be able to reflect solar energy onto robots operating in the dark cold crater. TFs utilize a shape transformation mechanism to un-fold from a compact volume to a large reflective surface, and to control how much-and where-the energy is projected, and by adjusting for the changing position of the sun. TFs would enable in-situ resource utilization (ISRU) activities within locations of high interest that would normally be unreachable because of their extreme environment

Fabrication of Diamond Based Sensors for Use in Extreme Environments

Directory of Open Access Journals (Sweden)

Gopi K. Samudrala

2015-04-01

Full Text Available Electrical and magnetic sensors can be lithographically fabricated on top of diamond substrates and encapsulated in a protective layer of chemical vapor deposited single crystalline diamond. This process when carried out on single crystal diamond anvils employed in high pressure research is termed as designer diamond anvil fabrication. These designer diamond anvils allow researchers to study electrical and magnetic properties of materials under extreme conditions without any possibility of damaging the sensing elements. We describe a novel method for the fabrication of designer diamond anvils with the use of maskless lithography and chemical vapor deposition in this paper. This method can be utilized to produce diamond based sensors which can function in extreme environments of high pressures, high and low temperatures, corrosive and high radiation conditions. We demonstrate applicability of these diamonds under extreme environments by performing electrical resistance measurements during superconducting transition in rare earth doped iron-based compounds under high pressures to 12 GPa and low temperatures to 10 K.

Test fields cannot destroy extremal black holes

International Nuclear Information System (INIS)

Natário, José; Queimada, Leonel; Vicente, Rodrigo

2016-01-01

We prove that (possibly charged) test fields satisfying the null energy condition at the event horizon cannot overspin/overcharge extremal Kerr–Newman or Kerr–Newman–anti de Sitter black holes, that is, the weak cosmic censorship conjecture cannot be violated in the test field approximation. The argument relies on black hole thermodynamics (without assuming cosmic censorship), and does not depend on the precise nature of the fields. We also discuss generalizations of this result to other extremal black holes. (paper)

Automated Precision Maneuvering and Landing in Extreme and Constrained Environments

Data.gov (United States)

National Aeronautics and Space Administration — Autonomous, precise maneuvering and landing in extreme and constrained environments is a key enabler for future NASA missions. Missions to map the interior of a...

Advances in hybrid optics physical sensors for extreme environments

Science.gov (United States)

Riza, Nabeel A.

2010-04-01

Highlighted are novel innovations in hybrid optical design physical sensors for extreme environments. Various hybrid design compositions are proposed that are suited for a particular sensor application. Examples includes combining freespace (wireless) and fiber-optics (wired) for gas turbine sensing and combining single crystal and sintered Silicon Carbide (SiC) materials for robust extreme environment Coefficent of Thermal Expansion (CTE) matched frontend probe design. Sensor signal processing also includes the hybrid theme where for example Black-Body radiation thermometry (pyrometry) is combined with laser interferometry to provide extreme temperature measurements. The hybrid theme also operates on the optical device level where a digital optical device such as a Digital Micromirror Device (DMD) is combined with an analog optical device such as an Electronically Controlled Variable Focal Length Lens (ECVFL) to deliver a smart and compressive Three Dimensional (3-D) imaging sensor for remote scene and object shape capture including both ambient light (passive) mode and active laser targeting and receive processing. Within a device level, the hybrid theme also operates via combined analog and digital control such as within a wavelength-coded variable optical delay line. These powerful hybrid design optical sensors have numerous applications in engineering and science applications from the military to the commercial/industrial sectors.

Quest for the QCD phase diagram in extreme environments

Energy Technology Data Exchange (ETDEWEB)

Fukushima, Kenji, E-mail: fuku@rk.phys.keio.ac.jp [Keio University, Department of Physics (Japan)

2013-03-15

We review the state-of-the-art status of the research on the phase diagram of QCD matter out of quarks and gluons. Our discussions particularly include the extreme environments such as the high temperature, the high baryon density, and the strong magnetic field.

Rapid adaptation of microalgae to bodies of water with extreme pollution from uranium mining: An explanation of how mesophilic organisms can rapidly colonise extremely toxic environments

Energy Technology Data Exchange (ETDEWEB)

García-Balboa, C.; Baselga-Cervera, B. [Genetica, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid (Spain); García-Sanchez, A.; Igual, J.M. [Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA-CSIC), PO Box 257, 37071 Salamanca (Spain); Lopez-Rodas, V. [Genetica, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid (Spain); Costas, E., E-mail: ecostas@vet.ucm.es [Genetica, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid (Spain)

2013-11-15

Highlights: •Some microalgae species survive to extreme environments in ponds of residual waters from uranium mining. •Adaptation of microalgae to U arose very fast. •Spontaneous mutations that confer large adaptive value were able to produce the adaptation to residual waters of U mining. •Adaptation to more extreme waters of U mining is only possible after the recombination subsequent to sexual mating. •Resistant microalgae bio-adsorbs uranium to the cell wall and internalises uranium inside the cytoplasm. -- Abstract: Extreme environments may support communities of microalgae living at the limits of their tolerance. It is usually assumed that these extreme environments are inhabited by extremophile species. However, global anthropogenic environmental changes are generating new extreme environments, such as mining-effluent pools of residual waters from uranium mining with high U levels, acidity and radioactivity in Salamanca (Spain). Certain microalgal species have rapidly adapted to these extreme waters (uranium mining in this area began in 1960). Experiments have demonstrated that physiological acclimatisation would be unable to achieve adaptation. In contrast, rapid genetic adaptation was observed in waters ostensibly lethal to microalgae by means of rare spontaneous mutations that occurred prior to the exposure to effluent waters from uranium mining. However, adaptation to the most extreme conditions was only possible after recombination through sexual mating because adaptation requires more than one mutation. Microalgae living in extreme environments could be the descendants of pre-selective mutants that confer significant adaptive value to extreme contamination. These “lucky mutants” could allow for the evolutionary rescue of populations faced with rapid environmental change.

Rapid adaptation of microalgae to bodies of water with extreme pollution from uranium mining: An explanation of how mesophilic organisms can rapidly colonise extremely toxic environments

International Nuclear Information System (INIS)

García-Balboa, C.; Baselga-Cervera, B.; García-Sanchez, A.; Igual, J.M.; Lopez-Rodas, V.; Costas, E.

2013-01-01

Highlights: •Some microalgae species survive to extreme environments in ponds of residual waters from uranium mining. •Adaptation of microalgae to U arose very fast. •Spontaneous mutations that confer large adaptive value were able to produce the adaptation to residual waters of U mining. •Adaptation to more extreme waters of U mining is only possible after the recombination subsequent to sexual mating. •Resistant microalgae bio-adsorbs uranium to the cell wall and internalises uranium inside the cytoplasm. -- Abstract: Extreme environments may support communities of microalgae living at the limits of their tolerance. It is usually assumed that these extreme environments are inhabited by extremophile species. However, global anthropogenic environmental changes are generating new extreme environments, such as mining-effluent pools of residual waters from uranium mining with high U levels, acidity and radioactivity in Salamanca (Spain). Certain microalgal species have rapidly adapted to these extreme waters (uranium mining in this area began in 1960). Experiments have demonstrated that physiological acclimatisation would be unable to achieve adaptation. In contrast, rapid genetic adaptation was observed in waters ostensibly lethal to microalgae by means of rare spontaneous mutations that occurred prior to the exposure to effluent waters from uranium mining. However, adaptation to the most extreme conditions was only possible after recombination through sexual mating because adaptation requires more than one mutation. Microalgae living in extreme environments could be the descendants of pre-selective mutants that confer significant adaptive value to extreme contamination. These “lucky mutants” could allow for the evolutionary rescue of populations faced with rapid environmental change

Rapid adaptation of microalgae to bodies of water with extreme pollution from uranium mining: an explanation of how mesophilic organisms can rapidly colonise extremely toxic environments.

Science.gov (United States)

García-Balboa, C; Baselga-Cervera, B; García-Sanchez, A; Igual, J M; Lopez-Rodas, V; Costas, E

2013-11-15

Extreme environments may support communities of microalgae living at the limits of their tolerance. It is usually assumed that these extreme environments are inhabited by extremophile species. However, global anthropogenic environmental changes are generating new extreme environments, such as mining-effluent pools of residual waters from uranium mining with high U levels, acidity and radioactivity in Salamanca (Spain). Certain microalgal species have rapidly adapted to these extreme waters (uranium mining in this area began in 1960). Experiments have demonstrated that physiological acclimatisation would be unable to achieve adaptation. In contrast, rapid genetic adaptation was observed in waters ostensibly lethal to microalgae by means of rare spontaneous mutations that occurred prior to the exposure to effluent waters from uranium mining. However, adaptation to the most extreme conditions was only possible after recombination through sexual mating because adaptation requires more than one mutation. Microalgae living in extreme environments could be the descendants of pre-selective mutants that confer significant adaptive value to extreme contamination. These "lucky mutants" could allow for the evolutionary rescue of populations faced with rapid environmental change. Copyright © 2013 Elsevier B.V. All rights reserved.

LiDAR in extreme environment: surveying in Antarctica

Directory of Open Access Journals (Sweden)

D. Abate

2013-10-01

Full Text Available This study was performed under the patronage of the Italian National Research Programme in Antarctica (PNRA with the aim to realize a high resolution Digital Elevation Model (DEM of the moraine named "Boulder Clay" which insists approximately 7 km far from the Italian Research Base "Mario Zucchelli Station" in the Terra Nova Bay area. The DEM will be included in the project for the construction of two runways to be used as support facilities for the scientific research campaigns which take place on regular basis each year. Although the research efforts to realize a detailed cartography of the area is on-going, for the specific aim and urgency of this project it was decided to perform a laser scanning survey in this extreme environment in order to obtain contour lines describing the terrain elevation each 50 cm and volume analysis. The final result will be super imposed on a photogrammetric DEM with contour lines each 2.5 m and satellite images. This paper focus both on the final scientific data and on all the challenges have to be faced in such extreme and particular environment during the laser scanning survey.

Evidence of Molecular Adaptation to Extreme Environments and Applicability to Space Environments

Directory of Open Access Journals (Sweden)

Filipović, M. D.

2008-06-01

Full Text Available This is initial investigation of gene signatures responsible for adapting microscopic life to the extreme Earth environments. We present preliminary results on identification of the clusters of orthologous groups (COGs common to several hyperthermophiles and exclusion of those common to a mesophile (non-hyperthermophile: {it Escherichia coli (E. coli K12}, will yield a group of proteins possibly involved in adaptation to life under extreme temperatures. Comparative genome analyses represent a powerful tool in discovery of novel genes responsible for adaptation to specific extreme environments. Methanogens stand out as the only group of organisms that have species capable of growth at 0D C ({it Metarhizium frigidum (M.~frigidum} and {it Methanococcoides burtonii (M.~burtonii} and 110D C ({it Methanopyrus kandleri (M.~kandleri}. Although not all the components of heat adaptation can be attributed to novel genes, the {it chaperones} known as heat shock proteins stabilize the enzymes under elevated temperature. However, highly conserved {it chaperons} found in bacteria and eukaryots are not present in hyperthermophilic Archea, rather, they have a unique {it chaperone TF55}. Our aim was to use software which we specifically developed for extremophile genome comparative analyses in order to search for additional novel genes involved in hyperthermophile adaptation. The followinghyperthermophile genomes incorporated in this software were used forthese studies: {it Methanocaldococcus jannaschii (M.~jannaschii, M.~kandleri, Archaeoglobus fulgidus (A.~fulgidus} and threespecies of {it Pyrococcus}. Common genes were annotated and groupedaccording to their roles in cellular processes where such informationwas available and proteins not previously implicated in theheat-adaptation of hyperthermophiles were identified. Additionalexperimental data are needed in order to learn more about theseproteins. To address non-gene based components of thermaladaptation

Evidence of molecular adaptation to extreme environments and applicability to space environments

Directory of Open Access Journals (Sweden)

Filipović M.

2008-01-01

Full Text Available This is initial investigation of gene signatures responsible for adapting microscopic life to the extreme Earth environments. We present preliminary results on identification of the clusters of orthologous groups (COGs common to several hyperthermophiles and exclusion of those common to a mesophile (non-hyperthermophile: Escherichia coli (E. coli K12, will yield a group of proteins possibly involved in adaptation to life under extreme temperatures. Comparative genome analyses represent a powerful tool in discovery of novel genes responsible for adaptation to specific extreme environments. Methanogens stand out as the only group of organisms that have species capable of growth at 0ºC (Metarhizium frigidum (M. frigidum and Methanococcoides burtonii (M. burtonii and 110ºC (Methanopyrus kandleri (M. kandleri. Although not all the components of heat adaptation can be attributed to novel genes, the chaperones known as heat shock proteins stabilize the enzymes under elevated temperature. However, highly conserved chaperons found in bacteria and eukaryots are not present in hyperthermophilic Archea, rather, they have a unique chaperone TF55. Our aim was to use software which we specifically developed for extremophile genome comparative analyses in order to search for additional novel genes involved in hyperthermophile adaptation. The following hyperthermophile genomes incorporated in this software were used for these studies: Methanocaldococcus jannaschii (M. jannaschii, M. kandleri, Archaeoglobus fulgidus (A. fulgidus and three species of Pyrococcus. Common genes were annotated and grouped according to their roles in cellular processes where such information was available and proteins not previously implicated in the heat-adaptation of hyperthermophiles were identified. Additional experimental data are needed in order to learn more about these proteins. To address non-gene based components of thermal adaptation, all sequenced extremophiles were

Motor Controller for Extreme Environments Based on SiGe, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The proposed innovation is a motor-control subsystem capable of operation in extreme environments, including those to be encountered on the Moon and Mars....

Relations Between Self-Reported and Linguistic Monitoring Assessments of Affective Experience in an Extreme Environment.

Science.gov (United States)

Smith, Nathan

2018-03-01

Approaches for monitoring psychosocial health in challenging environments are needed to maintain the performance and safety of personnel. The purpose of the present research was to examine the relationship between 2 candidate methods (self-reported and linguistics) for monitoring affective experience during extreme environment activities. A single-subject repeated-measures design was used in the present work. The participant was a 46-year-old individual scheduled to complete a self-supported ski expedition across Arctic Greenland. The expedition lasted 28 days, and conditions included severe cold, low stimulation, whiteouts, limited habitability, and threats to life and limb. During the expedition, the participant completed a daily self-report log including assessment of psychological health (perceptions of control and affect) and a video diary (emotion). Video diary entries were subjected to linguistic inquiry and word count analyses before the links between self-report and linguistic data across the expedition period were tested. Similarities in the pattern of self-reported and linguistic assessments emerged across the expedition period. A number of predictable correlations were identified between self-reported and linguistic assessments of affective/emotional experience. Overall, there was better agreement between self-reports and linguistic analytics for indicators of negative affect/emotion. Future research should build on this initial study to further test the links between self-reported affect and emotional states monitored via linguistics. This could help develop methods for monitoring psychological health in extreme environments and support organizational decision making. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Copahue Geothermal System: A Volcanic Environment with Rich Extreme Prokaryotic Biodiversity.

Science.gov (United States)

Urbieta, María Sofía; Porati, Graciana Willis; Segretín, Ana Belén; González-Toril, Elena; Giaveno, María Alejandra; Donati, Edgardo Rubén

2015-07-08

The Copahue geothermal system is a natural extreme environment located at the northern end of the Cordillera de los Andes in Neuquén province in Argentina. The geochemistry and consequently the biodiversity of the area are dominated by the activity of the Copahue volcano. The main characteristic of Copahue is the extreme acidity of its aquatic environments; ponds and hot springs of moderate and high temperature as well as Río Agrio. In spite of being an apparently hostile location, the prokaryotic biodiversity detected by molecular ecology techniques as well as cultivation shows a rich and diverse environment dominated by acidophilic, sulphur oxidising bacteria or archaea, depending on the conditions of the particular niche studied. In microbial biofilms, found in the borders of the ponds where thermal activity is less intense, the species found are completely different, with a high presence of cyanobacteria and other photosynthetic species. Our results, collected during more than 10 years of work in Copahue, have enabled us to outline geomicrobiological models for the different environments found in the ponds and Río Agrio. Besides, Copahue seems to be the habitat of novel, not yet characterised autochthonous species, especially in the domain Archaea.

The Future of Coral Reefs Subject to Rapid Climate Change: Lessons from Natural Extreme Environments

Directory of Open Access Journals (Sweden)

Emma F. Camp

2018-02-01

Full Text Available Global climate change and localized anthropogenic stressors are driving rapid declines in coral reef health. In vitro experiments have been fundamental in providing insight into how reef organisms will potentially respond to future climates. However, such experiments are inevitably limited in their ability to reproduce the complex interactions that govern reef systems. Studies examining coral communities that already persist under naturally-occurring extreme and marginal physicochemical conditions have therefore become increasingly popular to advance ecosystem scale predictions of future reef form and function, although no single site provides a perfect analog to future reefs. Here we review the current state of knowledge that exists on the distribution of corals in marginal and extreme environments, and geographic sites at the latitudinal extremes of reef growth, as well as a variety of shallow reef systems and reef-neighboring environments (including upwelling and CO2 vent sites. We also conduct a synthesis of the abiotic data that have been collected at these systems, to provide the first collective assessment on the range of extreme conditions under which corals currently persist. We use the review and data synthesis to increase our understanding of the biological and ecological mechanisms that facilitate survival and success under sub-optimal physicochemical conditions. This comprehensive assessment can begin to: (i highlight the extent of extreme abiotic scenarios under which corals can persist, (ii explore whether there are commonalities in coral taxa able to persist in such extremes, (iii provide evidence for key mechanisms required to support survival and/or persistence under sub-optimal environmental conditions, and (iv evaluate the potential of current sub-optimal coral environments to act as potential refugia under changing environmental conditions. Such a collective approach is critical to better understand the future survival of

Consideration of Task Performance for Robots Engaged in Extremely Dangerous Environment in Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Hong, Seung Mo; Han, Kee Soo; Yi, Sung Deok; Kim, Seoung Rae [Nuclear Engineering Service and Solution Co. Ltd., Daejeon (Korea, Republic of); Choi, Young [KAERI, Daejeon (Korea, Republic of)

2015-05-15

After Fukushima Daiichi Nuclear Accident, it is started to pay more attention to operation and accident of nuclear power plants (NPPs). For domestic nuclear industry, it was recommended to establish corresponding strategies against accidents due to extremely dangerous natural disasters. Each nuclear power plant is also preparing to establish strategies to secure nuclear safety functions by estimating the counterplans for extreme accidents. Robots are particularly being used to access the areas where those are dangerous for human beings to access or to restore the accident. Robot technologies in NPPs are emerging cutting-edge technologies that are just a start except the developed countries like USA, Japan, etc. But they are carefully considered because they have the advantages of performing tasks in extremely dangerous environment in NPPs instead of human beings. In this study, the applicability of robots will be considered in extremely dangerous environment in NPPs. Accurate judgment of the inside situation of the plant and quick actions in the extreme condition like earthquake accompanied by loss of all AC powers should be considered as major function in terms of prevention of accident spread. According to the reported stress test results of domestic NPPs, the difficult things for operators to carry out in extreme conditions can be predictable, therefore the active use of robots as accident mitigation strategies will be helpful to reduce the unnecessary spending for facility improvement. Current trend of domestic and foreign robot technology development focuses on the information search of the inside of the plant and development of preventive maintenance of NPPs. As seen actually in Fukushima Daiichi, main roles of robots place emphasis on measuring the inside radiation level accessing to the area where operator cannot access and delivering information which can support operator's decision-making and actions. Therefore, it is considered that development of

Copahue Geothermal System: A Volcanic Environment with Rich Extreme Prokaryotic Biodiversity

Directory of Open Access Journals (Sweden)

María Sofía Urbieta

2015-07-01

Full Text Available The Copahue geothermal system is a natural extreme environment located at the northern end of the Cordillera de los Andes in Neuquén province in Argentina. The geochemistry and consequently the biodiversity of the area are dominated by the activity of the Copahue volcano. The main characteristic of Copahue is the extreme acidity of its aquatic environments; ponds and hot springs of moderate and high temperature as well as Río Agrio. In spite of being an apparently hostile location, the prokaryotic biodiversity detected by molecular ecology techniques as well as cultivation shows a rich and diverse environment dominated by acidophilic, sulphur oxidising bacteria or archaea, depending on the conditions of the particular niche studied. In microbial biofilms, found in the borders of the ponds where thermal activity is less intense, the species found are completely different, with a high presence of cyanobacteria and other photosynthetic species. Our results, collected during more than 10 years of work in Copahue, have enabled us to outline geomicrobiological models for the different environments found in the ponds and Río Agrio. Besides, Copahue seems to be the habitat of novel, not yet characterised autochthonous species, especially in the domain Archaea.

Creating and Understanding Hybrid Interfaces of Multifunctional Composite Laminates for Extreme Environments

Data.gov (United States)

National Aeronautics and Space Administration — Due to increasing needs for lightweight and multifunctional structures and materials that can operate at and sustain the extreme environment such as high temperature...

Extreme-Environment Silicon-Carbide (SiC) Wireless Sensor Suite

Science.gov (United States)

Yang, Jie

2015-01-01

Phase II objectives: Develop an integrated silicon-carbide wireless sensor suite capable of in situ measurements of critical characteristics of NTP engine; Compose silicon-carbide wireless sensor suite of: Extreme-environment sensors center, Dedicated high-temperature (450 deg C) silicon-carbide electronics that provide power and signal conditioning capabilities as well as radio frequency modulation and wireless data transmission capabilities center, An onboard energy harvesting system as a power source.

Prevention through policy: Urban macroplastic leakages to the marine environment during extreme rainfall events.

Science.gov (United States)

Axelsson, Charles; van Sebille, Erik

2017-11-15

The leakage of large plastic litter (macroplastics) into the ocean is a major environmental problem. A significant fraction of this leakage originates from coastal cities, particularly during extreme rainfall events. As coastal cities continue to grow, finding ways to reduce this macroplastic leakage is extremely pertinent. Here, we explore why and how coastal cities can reduce macroplastic leakages during extreme rainfall events. Using nine global cities as a basis, we establish that while cities actively create policies that reduce plastic leakages, more needs to be done. Nonetheless, these policies are economically, socially and environmentally cobeneficial to the city environment. While the lack of political engagement and economic concerns limit these policies, lacking social motivation and engagement is the largest limitation towards implementing policy. We recommend cities to incentivize citizen and municipal engagement with responsible usage of plastics, cleaning the environment and preparing for future extreme rainfall events. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Constructing and Screening a Metagenomic Library of a Cold and Alkaline Extreme Environment.

Science.gov (United States)

Glaring, Mikkel A; Vester, Jan K; Stougaard, Peter

2017-01-01

Natural cold or alkaline environments are common on Earth. A rare combination of these two extremes is found in the permanently cold (less than 6 °C) and alkaline (pH above 10) ikaite columns in the Ikka Fjord in Southern Greenland. Bioprospecting efforts have established the ikaite columns as a source of bacteria and enzymes adapted to these conditions. They have also highlighted the limitations of cultivation-based methods in this extreme environment and metagenomic approaches may provide access to novel extremophilic enzymes from the uncultured majority of bacteria. Here, we describe the construction and screening of a metagenomic library of the prokaryotic community inhabiting the ikaite columns.

Quantitative Sensory Testing and Current Perception Threshold Testing in Patients With Chronic Pain Following Lower Extremity Fracture.

Science.gov (United States)

Griffioen, Mari A; Greenspan, Joel D; Johantgen, Meg; Von Rueden, Kathryn; O'Toole, Robert V; Dorsey, Susan G; Renn, Cynthia L

2018-01-01

Chronic pain is a significant problem for patients with lower extremity injuries. While pain hypersensitivity has been identified in many chronic pain conditions, it is not known whether patients with chronic pain following lower extremity fracture report pain hypersensitivity in the injured leg. To quantify and compare peripheral somatosensory function and sensory nerve activation thresholds in persons with chronic pain following lower extremity fractures with a cohort of persons with no history of lower extremity fractures. This was a cross-sectional study where quantitative sensory testing and current perception threshold testing were conducted on the injured and noninjured legs of cases and both legs of controls. A total of 14 cases and 28 controls participated in the study. Mean time since injury at the time of testing for cases was 22.3 (standard deviation = 12.1) months. The warmth detection threshold ( p = .024) and nerve activation thresholds at 2,000 Hz ( p sensory nerve function at the site of injury in patients with chronic pain following lower extremity fractures using quantitative sensory testing and current perception threshold testing.

Magnetic Reconnection in Extreme Astrophysical Environments

Science.gov (United States)

Uzdensky, Dmitri

Magnetic reconnection is a fundamental plasma physics process of breaking ideal-MHD's frozen-in constraints on magnetic field connectivity and of dramatic rearranging of the magnetic topol-ogy, which often leads to a violent release of the free magnetic energy. Reconnection has long been acknowledged to be of great importance in laboratory plasma physics (magnetic fusion) and in space and solar physics (responsible for solar flares and magnetospheric substorms). In addition, its importance in Astrophysics has been increasingly recognized in recent years. However, due to a great diversity of astrophysical environments, the fundamental physics of astrophysical magnetic reconnection can be quite different from that of the traditional recon-nection encountered in the solar system. In particular, environments like the solar corona and the magnetosphere are characterized by relatively low energy densities, where the plasma is ad-equately described as a mixture of electrons and ions whose numbers are conserved and where the dissipated magnetic energy basically stays with the plasma. In contrast, in many high-energy astrophysical phenomena the energy density is so large that photons play as important a role as electrons and ions and, in particular, radiation pressure and radiative cooling become dominant. In this talk I focus on the most extreme case of high-energy-density astrophysical reconnec-tion — reconnection of magnetar-strength (1014 - 1015 Gauss) magnetic fields, important for giant flares in soft-gamma repeaters (SGRs), and for rapid magnetic energy release in either the central engines or in the relativistic jets of Gamma Ray Bursts (GRBs). I outline the key relevant physical processes and present a new theoretical picture of magnetic reconnection in these environments. The corresponding magnetic energy density is so enormous that, when suddenly released, it inevitably heats the plasma to relativistic temperatures, resulting in co-pious production of electron

Magnetic-Field-Assisted Assembly of Ordered Multifunctional Ceramic Nanocomposites for Extreme Environments

Science.gov (United States)

2016-04-01

SUBJECT TERMS carbon nanotubes, composite, electromagnetic shielding , extreme environments, magnetism, fibers, woven composite, boron nitride...The samples were sealed in glass vial and exposed to the magnetic field immediately after deposition prior to crystallization of PEG that allowed

Individual Traits, Personal Values, and Conflict Resolution in an Isolated, Confined, Extreme Environment.

Science.gov (United States)

Corneliussen, Jesper G; Leon, Gloria R; Kjærgaard, Anders; Fink, Birgit A; Venables, Noah C

2017-06-01

The study of personality traits, personal values, and the emergence of conflicts within groups performing in an isolated, confined, and extreme environment (ICE) may provide insights helpful for the composition and support of space crews for long duration missions. Studied pre/post and over the 2-yr period of the investigation were 10 Danish military personnel deployed to stations in Greenland on a 26-mo staggered rotation. Subjects completed the NEO PI-R, Triarchic Psychopathy Measure, and Portrait Values Questionnaire, and participated in structured interviews. During deployment, questionnaires were completed biweekly and a cognitive function test once a month. Personality findings indicated a generally well-adjusted group, above average in positive personality traits [Conscientiousness T-score = 59.4 (11.41); Agreeableness T-score = 54.4 (9.36)] and boldness. Personal values of benevolence and self-direction were highly rated. The decision when to "pick sides" and intervene during disagreements between group members was viewed as an important component of conflict resolution. There were no changes in positive/negative affect or cognitive function over the annual light/dark cycle. The personal values of group members appear highly compatible for living in a small group ICE environment for an extended period. Disagreements between group members impact the functioning of the entire group, particularly in regard to decisions whether to support one of the individuals or let the argument run its course. Extended training in strategies for conflict resolution are needed in planning for future long duration missions to avoid fault lines forming within the group.Corneliussen JG, Leon GR, Kjærgaard A, Fink BA, Venables NC. Individual traits, personal values, and conflict resolution in an isolated, confined, extreme environment. Aerosp Med Hum Perform. 2017; 88(6):535-543.

Construction of a Thermal Vacuum Chamber for Environment Test of Triple CubeSat Mission TRIO-CINEMA

Science.gov (United States)

Jeon, Jeheon; Lee, Seongwhan; Yoon, Seyoung; Seon, Jongho; Jin, Ho; Lee, Donghun; Lin, Robert P.

2013-12-01

TRiplet Ionospheric Observatory-CubeSat for Ion, Neutron, Electron & MAgnetic fields (TRIO-CINEMA) is a CubeSat with 3.14 kg in weight and 3-U (10 × 10 × 30 cm) in size, jointly developed by Kyung Hee University and UC Berkeley to measure magnetic fields of near Earth space and detect plasma particles. When a satellite is launched into orbit, it encounters ultrahigh vacuum and extreme temperature. To verify the operation and survivability of the satellite in such an extreme space environment, experimental tests are conducted on the ground using thermal vacuum chamber. This paper describes the temperature control device and monitoring system suitable for CubeSat test environment using the thermal vacuum chamber of the School of Space Research, Kyung Hee University. To build the chamber, we use a general purpose thermal analysis program and NX 6.0 TMG program. We carry out thermal vacuum tests on the two flight models developed by Kyung Hee University based on the thermal model of the TRIO-CINEMA satellite. It is expected from this experiment that proper operation of the satellite in the space environment will be achieved.

Construction of a Thermal Vacuum Chamber for Environment Test of Triple CubeSat Mission TRIO-CINEMA

Directory of Open Access Journals (Sweden)

Jeheon Jeon

2013-09-01

Full Text Available TRiplet Ionospheric Observatory-CubeSat for Ion, Neutron, Electron & MAgnetic fields (TRIO-CINEMA is a CubeSat with 3.14 kg in weight and 3-U (10 × 10 × 30 cm in size, jointly developed by Kyung Hee University and UC Berkeley to measure magnetic fields of near Earth space and detect plasma particles. When a satellite is launched into orbit, it encounters ultrahigh vacuum and extreme temperature. To verify the operation and survivability of the satellite in such an extreme space environment, experimental tests are conducted on the ground using thermal vacuum chamber. This paper describes the temperature control device and monitoring system suitable for CubeSat test environment using the thermal vacuum chamber of the School of Space Research, Kyung Hee University. To build the chamber, we use a general purpose thermal analysis program and NX 6.0 TMG program. We carry out thermal vacuum tests on the two flight models developed by Kyung Hee University based on the thermal model of the TRIO-CINEMA satellite. It is expected from this experiment that proper operation of the satellite in the space environment will be achieved.

Alteration of a human intestinal microbiota under extreme life environment in the Antarctica.

Science.gov (United States)

Jin, Jong-Sik; Touyama, Mutsumi; Yamada, Shin; Yamazaki, Takashi; Benno, Yoshimi

2014-01-01

The human intestinal microbiota (HIM) settles from birth and continues to change phenotype by some factors (e.g. host's diet) throughout life. However, the effect of extreme life environment on human HIM composition is not well known. To understand HIM fluctuation under extreme life environment in humans, fecal samples were collected from six Japanese men on a long Antarctic expedition. They explored Antarctica for 3 months and collected their fecal samples at once-monthly intervals. Using terminal restriction fragment length polymorphism (T-RFLP) and real time polymerase chain reaction (PCR) analysis, the composition of HIM in six subjects was investigated. Three subjects presented restoration of HIM after the expedition compared versus before and during the expedition. Two thirds samples collected during the expedition belonged to the same cluster in dendrogram. However, all through the expedition, T-RFLP patterns showed interindividual variability. Especially, Bifidobacterium spp. showed a tendency to decrease during and restore after the expedition. A reduction of Bifidobacterium spp. was observed in five subjects the first 1 month of the expedition. Bacteroides thetaiotaomicron, which is thought to proliferate during emotional stress, significantly decreased in one subject, indicating that other factors in addition to emotional stress may affect the composition of HIM in this study. These findings could be helpful to understand the effect of extreme life environment on HIM.

Maritime Military Decision Making in Environments of Extreme Information Ambiguity: An Initial Exploration

National Research Council Canada - National Science Library

Reeves, Andrew T

2005-01-01

... to make effective decisions. An environment of extreme information ambiguity, a dependent variable, is one of the most difficult components of a battle where the decision maker may reach a confusing and debilitating point...

Vertical GaN Devices for Power Electronics in Extreme Environments

Science.gov (United States)

2016-03-31

Vertical GaN Devices for Power Electronics in Extreme Environments Isik C. Kizilyalli (1), Robert J. Kaplar (2), O. Aktas (1), A. M. Armstrong (2...electronics applications. In this paper vertical p-n diodes and transistors fabricated on pseudo bulk low defect density (104 to 106 cm-2) GaN substrates are...discussed. Homoepitaxial MOCVD growth of GaN on its native substrate and being able to control doping has allowed the realization of vertical

Solid Lubricants and Coatings for Extreme Environments: State-of-the-Art Survey

Science.gov (United States)

Miyoshi, Kazuhisa

2007-01-01

An investigation was conducted to survey anticipated requirements for solid lubricants in lunar and Martian environments, as well as the effects of these environments on lubricants and their performance and durability. The success of habitats and vehicles on the Moon and Mars, and ultimately, of the human exploration of and permanent human presence on the Moon and Mars, are critically dependent on the correct and reliable operation of many moving mechanical assemblies and tribological components. The coefficient of friction and lifetime of any lubricant generally vary with the environment, and lubricants have very different characteristics under different conditions. It is essential, therefore, to select the right lubrication technique and lubricant for each mechanical and tribological application. Several environmental factors are hazardous to performance integrity on the Moon and Mars. Potential threats common to both the Moon and Mars are low ambient temperatures, wide daily temperature swings (thermal cycling), solar flux, cosmic radiation, and large quantities of dust. The surface of Mars has the additional challenges of dust storms, winds, and a carbon dioxide atmosphere. Solid lubricants and coatings are needed for lunar and Martian applications, where liquid lubricants are ineffective and undesirable, and these lubricants must perform well in the extreme environments of the Moon, Mars, and space, as well as on Earth, where they will be assembled and tested. No solid lubricants and coatings and their systems currently exist or have been validated that meet these requirements, so new solid lubricants must be designed and validated for these applications.

Cryogenic Fiber Optic Assemblies for Spaceflight Environments: Design, Manufacturing, Testing, and Integration

Science.gov (United States)

Thomes, W. Joe; Ott, Melanie N.; Chuska, Richard; Switzer, Robert; Onuma, Eleanya; Blair, Diana; Frese, Erich; Matyseck, Marc

2016-01-01

Fiber optic assemblies have been used on spaceflight missions for many years as an enabling technology for routing, transmitting, and detecting optical signals. Due to the overwhelming success of NASA in implementing fiber optic assemblies on spaceflight science-based instruments, system scientists increasingly request fibers that perform in extreme environments while still maintaining very high optical transmission, stability, and reliability. Many new applications require fiber optic assemblies that will operate down to cryogenic temperatures as low as 20 Kelvin. In order for the fiber assemblies to operate with little loss in optical throughput at these extreme temperatures requires a system level approach all the way from how the fiber assembly is manufactured to how it is held, routed, and integrated. The NASA Goddard Code 562 Photonics Group has been designing, manufacturing, testing, and integrating fiber optics for spaceflight and other high reliability applications for nearly 20 years. Design techniques and lessons learned over the years are consistently applied to developing new fiber optic assemblies that meet these demanding environments. System level trades, fiber assembly design methods, manufacturing, testing, and integration will be discussed. Specific recent examples of ground support equipment for the James Webb Space Telescope (JWST); the Ice, Cloud and Land Elevation Satellite-2 (ICESat-2); and others will be included.

Plants as extreme environments? Ni-resistant bacteria and Ni-hyperaccumulators of serpentine flora.

NARCIS (Netherlands)

Mengoni, A.; Schat, H.; Vangronsveld, J.

2010-01-01

During recent years there has been an increasing interest in the bacterial communities occurring in unusual, often extreme, environments. On serpentine outcrops around the world, a high diversity of plant species showing the peculiar features of metal hyperaccumulation is present. These metal

Extreme Programming: Maestro Style

Science.gov (United States)

Norris, Jeffrey; Fox, Jason; Rabe, Kenneth; Shu, I-Hsiang; Powell, Mark

2009-01-01

"Extreme Programming: Maestro Style" is the name of a computer programming methodology that has evolved as a custom version of a methodology, called extreme programming that has been practiced in the software industry since the late 1990s. The name of this version reflects its origin in the work of the Maestro team at NASA's Jet Propulsion Laboratory that develops software for Mars exploration missions. Extreme programming is oriented toward agile development of software resting on values of simplicity, communication, testing, and aggressiveness. Extreme programming involves use of methods of rapidly building and disseminating institutional knowledge among members of a computer-programming team to give all the members a shared view that matches the view of the customers for whom the software system is to be developed. Extreme programming includes frequent planning by programmers in collaboration with customers, continually examining and rewriting code in striving for the simplest workable software designs, a system metaphor (basically, an abstraction of the system that provides easy-to-remember software-naming conventions and insight into the architecture of the system), programmers working in pairs, adherence to a set of coding standards, collaboration of customers and programmers, frequent verbal communication, frequent releases of software in small increments of development, repeated testing of the developmental software by both programmers and customers, and continuous interaction between the team and the customers. The environment in which the Maestro team works requires the team to quickly adapt to changing needs of its customers. In addition, the team cannot afford to accept unnecessary development risk. Extreme programming enables the Maestro team to remain agile and provide high-quality software and service to its customers. However, several factors in the Maestro environment have made it necessary to modify some of the conventional extreme

Reliability of a New Lower-Extremity Motor Coordination Test

Directory of Open Access Journals (Sweden)

Antosiak-Cyrak Katarzyna

2015-12-01

Full Text Available Introduction. Motor coordination is a basic motor ability necessary for daily life, which also allows athletes to win a sports rivalry and patients to assess their recovery progress after therapy and rehabilitation. The aim of the present study was to assess the reliability of a new lower-extremity rate of movements test and testing apparatus.

Constructing and screening a metagenomic library of a cold and alkaline extreme environment

DEFF Research Database (Denmark)

Glaring, Mikkel Andreas; Vester, Jan Kjølhede; Stougaard, Peter

2017-01-01

Natural cold or alkaline environments are common on Earth. A rare combination of these two extremes is found in the permanently cold (less than 6 °C) and alkaline (pH above 10) ikaite columns in the Ikka Fjord in Southern Greenland. Bioprospecting efforts have established the ikaite columns...

Competition and facilitation structure plant communities under nurse tree canopies in extremely stressful environments.

Science.gov (United States)

Al-Namazi, Ali A; El-Bana, Magdy I; Bonser, Stephen P

2017-04-01

Nurse plant facilitation in stressful environments can produce an environment with relatively low stress under its canopy. These nurse plants may produce the conditions promoting intense competition between coexisting species under the canopy, and canopies may establish stress gradients, where stress increases toward the edge of the canopy. Competition and facilitation on these stress gradients may control species distributions in the communities under canopies. We tested the following predictions: (1) interactions between understory species shift from competition to facilitation in habitats experiencing increasing stress from the center to the edge of canopy of a nurse plant, and (2) species distributions in understory communities are controlled by competitive interactions at the center of canopy, and facilitation at the edge of the canopy. We tested these predictions using a neighbor removal experiment under nurse trees growing in arid environments. Established individuals of each of four of the most common herbaceous species in the understory were used in the experiment. Two species were more frequent in the center of the canopy, and two species were more frequent at the edge of the canopy. Established individuals of each species were subjected to neighbor removal or control treatments in both canopy center and edge habitats. We found a shift from competitive to facilitative interactions from the center to the edge of the canopy. The shift in the effect of neighbors on the target species can help to explain species distributions in these canopies. Canopy-dominant species only perform well in the presence of neighbors in the edge microhabitat. Competition from canopy-dominant species can also limit the performance of edge-dominant species in the canopy microhabitat. The shift from competition to facilitation under nurse plant canopies can structure the understory communities in extremely stressful environments.

Improving diversity in cultures of bacteria from an extreme environment

DEFF Research Database (Denmark)

Vester, Jan Kjølhede; Glaring, Mikkel Andreas; Stougaard, Peter

2013-01-01

The ikaite columns in the Ikka Fjord in Greenland represent one of the few permanently cold and alkaline environments on Earth, and the interior of the columns is home to a bacterial community adapted to these extreme conditions. The community is characterized by low cell numbers imbedded in a ca...... the diversity of the culture and many hitherto uncharacterized genera could be brought into culture by extended incubation time. Extended incubation time also gave rise to a more diverse community with a significant number of rare species not detected in the initial community....

Test-retest and interrater reliability of the functional lower extremity evaluation.

Science.gov (United States)

Haitz, Karyn; Shultz, Rebecca; Hodgins, Melissa; Matheson, Gordon O

2014-12-01

Repeated-measures clinical measurement reliability study. To establish the reliability and face validity of the Functional Lower Extremity Evaluation (FLEE). The FLEE is a 45-minute battery of 8 standardized functional performance tests that measures 3 components of lower extremity function: control, power, and endurance. The reliability and normative values for the FLEE in healthy athletes are unknown. A face validity survey for the FLEE was sent to sports medicine personnel to evaluate the level of importance and frequency of clinical usage of each test included in the FLEE. The FLEE was then administered and rated for 40 uninjured athletes. To assess test-retest reliability, each athlete was tested twice, 1 week apart, by the same rater. To assess interrater reliability, 3 raters scored each athlete during 1 of the testing sessions. Intraclass correlation coefficients were used to assess the test-retest and interrater reliability of each of the FLEE tests. In the face validity survey, the FLEE tests were rated as highly important by 58% to 71% of respondents but frequently used by only 26% to 45% of respondents. Interrater reliability intraclass correlation coefficients ranged from 0.83 to 1.00, and test-retest reliability ranged from 0.71 to 0.95. The FLEE tests are considered clinically important for assessing lower extremity function by sports medicine personnel but are underused. The FLEE also is a reliable assessment tool. Future studies are required to determine if use of the FLEE to make return-to-play decisions may reduce reinjury rates.

Solar Probe Plus MAG Sensor Thermal Design for Low Heater Power and Extreme Thermal Environment

Science.gov (United States)

Choi, Michael K.

2015-01-01

The heater power available for the Solar Probe Plus FIELDS MAG sensor is less than half of the heritage value for other missions. Nominally the MAG sensors are in the spacecraft's umbra. In the worst hot case, approximately 200 spacecraft communication downlinks, up to 10 hours each, are required at 0.7 AU. These downlinks require the spacecraft to slew 45 deg. about the Y-axis, exposing the MAG sensors and boom to sunlight. This paper presents the thermal design to meet the MAG sensor thermal requirements in the extreme thermal environment and with low heater power. A thermal balance test on the MAG sensor engineering model has verified the thermal design and correlated the thermal model for flight temperature predictions.

Enabling Structured Exploration of Workflow Performance Variability in Extreme-Scale Environments

Energy Technology Data Exchange (ETDEWEB)

Kleese van Dam, Kerstin; Stephan, Eric G.; Raju, Bibi; Altintas, Ilkay; Elsethagen, Todd O.; Krishnamoorthy, Sriram

2015-11-15

Workflows are taking an Workflows are taking an increasingly important role in orchestrating complex scientific processes in extreme scale and highly heterogeneous environments. However, to date we cannot reliably predict, understand, and optimize workflow performance. Sources of performance variability and in particular the interdependencies of workflow design, execution environment and system architecture are not well understood. While there is a rich portfolio of tools for performance analysis, modeling and prediction for single applications in homogenous computing environments, these are not applicable to workflows, due to the number and heterogeneity of the involved workflow and system components and their strong interdependencies. In this paper, we investigate workflow performance goals and identify factors that could have a relevant impact. Based on our analysis, we propose a new workflow performance provenance ontology, the Open Provenance Model-based WorkFlow Performance Provenance, or OPM-WFPP, that will enable the empirical study of workflow performance characteristics and variability including complex source attribution.

Generalist feeding strategies in Arctic freshwater fish: A mechanism for dealing with extreme environments

Science.gov (United States)

Laske, Sarah M.; Rosenberger, Amanda E.; Wipfli, Mark S.; Zimmerman, Christian E.

2018-01-01

Generalist feeding strategies are favoured in stressful or variable environments where flexibility in ecological traits is beneficial. Species that feed across multiple habitat types and trophic levels may impart stability on food webs through the use of readily available, alternative energy pools. In lakes, generalist fish species may take advantage of spatially and temporally variable prey by consuming both benthic and pelagic prey to meet their energy demands. Using stomach content and stable isotope analyses, we examined the feeding habits of fish species in Alaska's Arctic Coastal Plain (ACP) lakes to determine the prevalence of generalist feeding strategies as a mechanism for persistence in extreme environments (e.g. low productivity, extreme cold and short growing season). Generalist and flexible feeding strategies were evident in five common fish species. Fish fed on benthic and pelagic (or nektonic) prey and across trophic levels. Three species were clearly omnivorous, feeding on fish and their shared invertebrate prey. Dietary differences based on stomach content analysis often exceeded 70%, and overlap in dietary niches based on shared isotopic space varied from zero to 40%. Metrics of community‐wide trophic structure varied with the number and identity of species involved and on the dietary overlap and niche size of individual fishes. Accumulation of energy from shared carbon sources by Arctic fishes creates redundancy in food webs, increasing likely resistance to perturbations or stochastic events. Therefore, the generalist and omnivorous feeding strategies employed by ACP fish may maintain energy flow and food web stability in extreme environments.

Microbial ecology of extreme environments: Antarctic yeasts and growth in substrate-limited habitats

Science.gov (United States)

Vishniac, H. S.

1985-01-01

The high, dry valleys of the Ross Desert of Antarctic, characterized by extremely low temperatures, aridity and a depauperate biota, are used as an analog of the postulated extreme climates of other planetary bodies of the Solar System to test the hypothesis that if life could be supported by Ross, it might be possible where similar conditions prevail. The previously considered sterility of the Ross Desert soil ecosystem has yielded up an indigenous yeast, Cryptoccus vishniacci, which is able to resist the extremes of cold, wet and dry freezing, and long arid periods, while making minimal nutritional demands on the soil.

Magnetotactic Bacteria from Extreme Environments

Directory of Open Access Journals (Sweden)

Christopher T. Lefèvre

2013-03-01

Full Text Available Magnetotactic bacteria (MTB represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4 or greigite (Fe3S4 and cause cells to align along the Earth’s geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic–anoxic interface (OAI in water columns or sediments of aquatic habitats and it is currently thought that magnetosomes function as a means of making chemotaxis more efficient in locating and maintaining an optimal position for growth and survival at the OAI. Known cultured and uncultured MTB are phylogenetically associated with the Alpha-, Gamma- and Deltaproteobacteria classes of the phylum Proteobacteria, the Nitrospirae phylum and the candidate division OP3, part of the Planctomycetes-Verrucomicrobia-Chlamydiae (PVC bacterial superphylum. MTB are generally thought to be ubiquitous in aquatic environments as they are cosmopolitan in distribution and have been found in every continent although for years MTB were thought to be restricted to habitats with pH values near neutral and at ambient temperature. Recently, however, moderate thermophilic and alkaliphilic MTB have been described including: an uncultured, moderately thermophilic magnetotactic bacterium present in hot springs in northern Nevada with a probable upper growth limit of about 63 °C; and several strains of obligately alkaliphilic MTB isolated in pure culture from different aquatic habitats in California, including the hypersaline, extremely alkaline Mono Lake, with an optimal growth pH of >9.0.

Toxicity at the Edge of Life: A Review on Cyanobacterial Toxins from Extreme Environments.

Science.gov (United States)

Cirés, Samuel; Casero, María Cristina; Quesada, Antonio

2017-07-24

Cyanotoxins are secondary metabolites produced by cyanobacteria, of varied chemical nature and toxic effects. Although cyanobacteria thrive in all kinds of ecosystems on Earth even under very harsh conditions, current knowledge on cyanotoxin distribution is almost restricted to freshwaters from temperate latitudes. In this review, we bring to the forefront the presence of cyanotoxins in extreme environments. Cyanotoxins have been reported especially in polar deserts (both from the Arctic and Antarctica) and alkaline lakes, but also in hot deserts, hypersaline environments, and hot springs. Cyanotoxins detected in these ecosystems include neurotoxins-anatoxin-a, anatoxin-a (S), paralytic shellfish toxins, β-methylaminopropionic acid, N -(2-aminoethyl) glycine and 2,4-diaminobutyric acid- and hepatotoxins -cylindrospermopsins, microcystins and nodularins-with microcystins being the most frequently reported. Toxin production there has been linked to at least eleven cyanobacterial genera yet only three of these ( Arthrospira , Synechococcus and Oscillatoria ) have been confirmed as producers in culture. Beyond a comprehensive analysis of cyanotoxin presence in each of the extreme environments, this review also identifies the main knowledge gaps to overcome (e.g., scarcity of isolates and -omics data, among others) toward an initial assessment of ecological and human health risks in these amazing ecosystems developing at the very edge of life.

Challenges and Opportunities of Centrifugal Microfluidics for Extreme Point-of-Care Testing

Directory of Open Access Journals (Sweden)

Issac J. Michael

2016-02-01

Full Text Available The advantages offered by centrifugal microfluidic systems have encouraged its rapid adaptation in the fields of in vitro diagnostics, clinical chemistry, immunoassays, and nucleic acid tests. Centrifugal microfluidic devices are currently used in both clinical and point-of-care settings. Recent studies have shown that this new diagnostic platform could be potentially used in extreme point-of-care settings like remote villages in the Indian subcontinent and in Africa. Several technological inventions have decentralized diagnostics in developing countries; however, very few microfluidic technologies have been successful in meeting the demand. By identifying the finest difference between the point-of-care testing and extreme point-of-care infrastructure, this review captures the evolving diagnostic needs of developing countries paired with infrastructural challenges with technological hurdles to healthcare delivery in extreme point-of-care settings. In particular, the requirements for making centrifugal diagnostic devices viable in developing countries are discussed based on a detailed analysis of the demands in different clinical settings including the distinctive needs of extreme point-of-care settings.

Summary of presentation for research on social structure, agreement, and conflict in groups in extreme and isolated environments

Science.gov (United States)

1990-01-01

Despite a vast amount of research, little is known concerning the effect of group structure, and individuals' understanding of that structure, on conflict in Antarctic groups. The overall objective of the research discussed is to determine the interrelationships of group structure, social cognition, and group function and conflict in isolated and extreme environments. In the two decades following WWII, a large body of research focused on the physiological, psychological, and social psychological factors affecting the functioning of individuals and groups in a variety of extreme and isolated environments in both the Arctic and Antarctic. There are two primary reasons for further research of this type. First, Antarctic polar stations are considered to be natural laboratories for the social and behavioral sciences and provide an opportunity to address certain theoretical and empirical questions concerned with agreement and conflict in social groups in general and group behavior in extreme, isolated environments in particular. Recent advances in the analysis of social networks and intracultural variation have improved the methods and have shifted the theoretical questions. The research is motivated by three classes of questions: (1) What are the characteristics of the social relations among individuals working and living together in extreme and isolated environments?; (2) What do individuals understand about their group, how does that understanding develop, and how is it socially distributed?; and (3) What is the relationship between that understanding and the functioning of the social group? Answers to these questions are important if we are to advance our knowledge of how individuals and groups adapt to extreme environments. Second, although Antarctic winter-over candidates may be evaluated as qualified on the basis of individual characteristics, they may fail to adapt because of certain characteristics of the social group. Consequently, the ability of winter

Voltage, Temperature, Frequency Margin Test Report

DEFF Research Database (Denmark)

Denver, Troelz

1999-01-01

The purpose of the tests is to establish the camera functionality when it is exposed to an extreme environment for prolonged periods, thus simulating the end of life performance. This environment covers temperature, input clock frequency and supply voltage variation......The purpose of the tests is to establish the camera functionality when it is exposed to an extreme environment for prolonged periods, thus simulating the end of life performance. This environment covers temperature, input clock frequency and supply voltage variation...

47 CFR 2.1503 - Test environment.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Test environment. 2.1503 Section 2.1503 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL... Radiobeacons (EPIRBs) General § 2.1503 Test environment. (a) Measurement sites. Radiated emission tests for...

Results from the European Integrated Project '' New Materials for Extreme Environments (ExtreMat) ''

International Nuclear Information System (INIS)

Bolt, H.; Linsmeier, Ch.; Baluc, N.; Garcia-Rosales, G.; Gualco, G. C.; Simancik, F.

2006-01-01

The goal of the European Integrated Project '' ExtreMat '' is to provide and to industrialize new materials and their compounds for applications in extreme environments that are beyond reach with incremental materials development only. The R(and)D activities in this project aim to provide a) self-passivating protection materials for sensitive structures operated in physico-chemically aggressive environments at high temperatures; b) new heat sink materials with the capability of very efficient heat removal, often at very high temperature level; c) radiation resistant materials for very high operation temperatures; d) new processing routes for complex heterogeneous compounds that can be operated in extreme environments. Key applications for these new materials are in the sectors of fusion, advanced fission, space, and electronic applications. Further use of these materials is expected in spin-off fields, such as brake applications and energy conversion. The project started in December 2004 for a duration of five years and is supported by the European Community. The 37 project participants are from 13 EU member states and include 6 universities, 7 research institutes, 10 research centres and 14 industrial companies. Research results regarding the development of materials for application in nuclear fusion, especially on protection, heat sink, and radiation resistant materials will be presented. A view to other applications of these materials in the fields of fission, space and electronics will be given in the presentation. ExtreMat Project Partners: see http://www.extremat.org/. (author)

INTERSESSION RELIABILITY OF UPPER EXTREMITY ISOKINETIC PUSH-PULL TESTING.

Science.gov (United States)

Riemann, Bryan L; Davis, Sarah E; Huet, Kevin; Davies, George J

2016-02-01

Based on the frequency pushing and pulling patterns are used in functional activities, there is a need to establish an objective method of quantifying the muscle performance characteristics associated with these motions, particularly during the later stages of rehabilitation as criteria for discharge. While isokinetic assessment offers an approach to quantifying muscle performance, little is known about closed kinetic chain (CKC) isokinetic testing of the upper extremity (UE). To determine the intersession reliability of isokinetic upper extremity measurement of pushing and pulling peak force and average power at slow (0.24 m/s), medium (0.43 m/s) and fast (0.61 m/s) velocities in healthy young adults. The secondary purpose was to compare pushing and pulling peak force (PF) and average power (AP) between the upper extremity limbs (dominant, non-dominant) across the three velocities. Twenty-four physically active men and women completed a test-retest (>96 hours) protocol in order to establish isokinetic UE CKC reliability of PF and AP during five maximal push and pull repetitions at three velocities. Both limb and speed orders were randomized between subjects. High test-retest relative reliability using intraclass correlation coefficients (ICC2, 1) were revealed for PF (.91-.97) and AP (.85-.95) across velocities, limbs and directions. PF typical error (% coefficient of variation) ranged from 6.1% to 11.3% while AP ranged from 9.9% to 26.7%. PF decreased significantly (p pushing were significantly greater than pulling at all velocities, however the push-pull differences in PF became less as velocity increased. There were no significant differences identified between the dominant and nondominant limbs. Isokinetically derived UE CKC push-pull PF and AP are reliable measures. The lack of limb differences in healthy normal participants suggests that clinicians can consider bilateral comparisons when interpreting test performance. The increase in pushing PF and

The push-off test: development of a simple, reliable test of upper extremity weight-bearing capability.

Science.gov (United States)

Vincent, Joshua I; MacDermid, Joy C; Michlovitz, Susan L; Rafuse, Richard; Wells-Rowsell, Christina; Wong, Owen; Bisbee, Leslie

2014-01-01

Longitudinal clinical measurement study. The push-off test (POT) is a novel and simple measure of upper extremity weight-bearing that can be measured with a grip dynamometer. There are no published studies on the validity and reliability of the POT. The relationship between upper extremity self-report activity/participation and impairment measures remain an unexplored realm. The primary purpose of this study is to estimate the intra and inter-rater reliability and construct validity of the POT. The secondary purpose is to estimate the relationship between upper extremity self-report activity/participation questionnaires and impairment measures. A convenience sample of 22 patients with wrist or elbow injuries were tested for POT, wrist/elbow range of motion (ROM), isometric wrist extension strength (WES) and grip strength; and completed two self-report activity/participation questionnaires: Disability of the Arm, Shoulder and the Hand (DASH) and Work Limitations Questionnaire (WLQ-26). POT's inter and intra-rater reliability and construct validity was tested. Pearson's correlations were run between the impairment measures and self-report questionnaires to look into the relationship amongst them. The POT demonstrated high inter-rater reliability (ICC affected = 0.97; 95% C.I. 0.93-0.99; ICC unaffected = 0.85; 95% C.I. 0.68-0.94) and intra-rater reliability (ICC affected = 0.96; 95% C.I. 0.92-0.97; ICC unaffected = 0.92; 95% C.I. 0.85-0.97). The POT was correlated moderately with the DASH (r = -0.47; p = 0.03). While examining the relationship between upper extremity self-reported activity/participation questionnaires and impairment measures the strongest correlation was between the DASH and the POT (r = -0.47; p = 0.03) and none of the correlations with the other physical impairment measures reached significance. At-work disability demonstrated insignificant correlations with physical impairments. The POT test provides a reliable and easily

Anhydrobiotic insect Polypedilum vanderplanki: molecular mechanisms of DNA and protein protection against extreme environments.

Science.gov (United States)

Gusev, Oleg; Nakahara, Yuichi; Kikawada, Takahiro; Levinskikh, Margarita; Sychev, Vladimir; Okuda, Takashi

Some organisms showing no sign of living due to complete desiccation are nevertheless able to resume active life after rehydration. This peculiar biological state is referred to as "anhydrobiosis". Larvae of the sleeping chironomid, P. vanderplanki living in temporary pools in semi-arid areas on the African continent become completely desiccated upon drought, but can revive after water becomes available upon the next rain. The dried larvae can stand other extreme conditions, such as exposure to 100˚C, -270˚C, 100We have adopted several methods to evaluated DNA damage in cells of P. vanderplanki and cloned and analyzed expression of the main agent of genetic stress response showing that the larvae possess highly developed anti-stress genetic system, involving anti-oxidative stress genes, hsp and DNA reparation enzymes acting together to provide stability of proteins and DNA in the absence of water. From 2005, dried larvae were included in a number of research programs, including exposition to space environments onboard ISS and long-term exposure to outer space environment outside of ISS ("Expose-R" and"Biorisk" projects) and now are being considered for including into the Phobos-Grunt mission as a testing organism to analyze capability of resting stages of multicellular organism to interplanetary flights.

Astrobiology: Life in Extreme Environments

Science.gov (United States)

Kaur, Preeti

2011-01-01

Astrobiology is the study of the origin, evolution and distribution of life in the universe. It seeks to answer two important scientific questions: how did we get here and are we alone in the universe? Scientists begin by studying life on Earth and its limits. The discovery of extremophiles on Earth capable of surviving extremes encourages the…

Colors of extreme exo-Earth environments.

Science.gov (United States)

Hegde, Siddharth; Kaltenegger, Lisa

2013-01-01

The search for extrasolar planets has already detected rocky planets and several planetary candidates with minimum masses that are consistent with rocky planets in the habitable zone of their host stars. A low-resolution spectrum in the form of a color-color diagram of an exoplanet is likely to be one of the first post-detection quantities to be measured for the case of direct detection. In this paper, we explore potentially detectable surface features on rocky exoplanets and their connection to, and importance as, a habitat for extremophiles, as known on Earth. Extremophiles provide us with the minimum known envelope of environmental limits for life on our planet. The color of a planet reveals information on its properties, especially for surface features of rocky planets with clear atmospheres. We use filter photometry in the visible as a first step in the characterization of rocky exoplanets to prioritize targets for follow-up spectroscopy. Many surface environments on Earth have characteristic albedos and occupy a different color space in the visible waveband (0.4-0.9 μm) that can be distinguished remotely. These detectable surface features can be linked to the extreme niches that support extremophiles on Earth and provide a link between geomicrobiology and observational astronomy. This paper explores how filter photometry can serve as a first step in characterizing Earth-like exoplanets for an aerobic as well as an anaerobic atmosphere, thereby prioritizing targets to search for atmospheric biosignatures.

Advanced Life Systems for Extreme Environments: An Arctic Application

Science.gov (United States)

Lewis, Carol E.; Stanford, Kerry L.; Bubenheim, David L.; Covington, Alan (Technical Monitor)

1995-01-01

The problems of obtaining adequate pure drinking water and disposing of liquid and solid waste in the U.S. Arctic, a region where virtually all water is frozen solid for much of the year, has led to unsanitary solutions (U.S. Arctic Research Commission). These solutions are also damaging to the environment. Sanitation and a safe water supply are particularly problems in rural villages. About one-fourth of Alaska's 86.000 Native residents live in these communities. They are without running water and use plastic buckets for toilets. The outbreak of diseases is believed to be partially attributable to exposure to human waste. Villages with the most frequent outbreaks of disease are those in which running water is difficult to obtain (Office of Technology Assessment, 1994). Waste is emptied into open lagoons, rivers, or onto the sea coast. It does not degrade rapidly and in addition to affecting human health, can be harmful to the fragile ecology of the Arctic and the indigenous wildlife and fish populations. Advanced Life Systems for Extreme Environments (ALSEE) provides a solution to sanitation and safe water problems. The system uses an advanced integrated technology developed for Antarctic and space applications. ALSEE uses the systems approach to address more than waste and water problems. By incorporating hydroponic horticulture and aquaculture into the waste treatment system, ALSEE addresses the quality and quantity of fresh foods available to Arctic residents. A temperate climate is required for year-round plant growth. ALSEE facilities can be designed to include a climate controlled area within the structure. This type of environment is a change from the long periods of darkness and cold found in the Arctic and can help alleviate stress so often associated with these extremes. While the overall concept of ALSEE projects is advanced, system facilities can be operated by village residents with appropriate training. ALSEE provides continuing training and

Lower extremity functional tests and risk of injury in division iii collegiate athletes.

Science.gov (United States)

Brumitt, Jason; Heiderscheit, Bryan C; Manske, Robert C; Niemuth, Paul E; Rauh, Mitchell J

2013-06-01

Functional tests have been used primarily to assess an athlete's fitness or readiness to return to sport. The purpose of this prospective cohort study was to determine the ability of the standing long jump (SLJ) test, the single-leg hop (SLH) for distance test, and the lower extremity functional test (LEFT) as preseason screening tools to identify collegiate athletes who may be at increased risk for a time-loss sports-related low back or lower extremity injury. A total of 193 Division III athletes from 15 university teams (110 females, age 19.1 ± 1.1 y; 83 males, age 19.5 ± 1.3 y) were tested prior to their sports seasons. Athletes performed the functional tests in the following sequence: SLJ, SLH, LEFT. The athletes were then prospectively followed during their sports season for occurrence of low back or LE injury. Female athletes who completed the LEFT in $118 s were 6 times more likely (OR=6.4, 95% CI: 1.3, 31.7) to sustain a thigh or knee injury. Male athletes who completed the LEFT in #100 s were more likely to experience a time-loss injury to the low back or LE (OR=3.2, 95% CI: 1.1, 9.5) or a foot or ankle injury (OR=6.7, 95% CI: 1.5, 29.7) than male athletes who completed the LEFT in 101 s or more. Female athletes with a greater than 10% side-to-side asymmetry between SLH distances had a 4-fold increase in foot or ankle injury (cut point: >10%; OR=4.4, 95% CI: 1.2, 15.4). Male athletes with SLH distances (either leg) at least 75% of their height had at least a 3-fold increase (OR=3.6, 95% CI: 1.2, 11.2 for the right LE; OR=3.6, 95% CI: 1.2, 11.2 for left LE) in low back or LE injury. The LEFT and the SLH tests appear useful in identifying Division III athletes at risk for a low back or lower extremity sports injury. Thus, these tests warrant further consideration as preparticipatory screening examination tools for sport injury in this population. The single-leg hop for distance and the lower extremity functional test, when administered to Division III

From Local to EXtreme Environments (FLEXE): Promoting Earth Systems Science Literacy Through Student Inquiry and Real Data

Science.gov (United States)

Goehring, E. C.; Carlsen, W.; Larsen, J.; Simms, E.; Smith, M.

2007-12-01

From Local to EXtreme Environments (FLEXE) is an innovative new project of the GLOBE Program that involves middle and high school students in systematic, facilitated analyses and comparisons of real environmental data. Through FLEXE, students collect and analyze data from various sources, including the multi-year GLOBE database, deep-sea scientific research projects, and direct measurements of the local environment collected by students using GLOBE sampling protocols. Initial FLEXE materials and training have focused on student understanding of energy transfer through components of the Earth system, including a comparison of how local environmental conditions differ from those found at deep-sea hydrothermal vent communities. While the importance of data acquisition, accuracy and replication is emphasized, FLEXE is also uniquely structured to deepen students' understanding of multiple aspects of the process and nature of science, including written communication of results and on-line peer review. Analyses of data are facilitated through structured, web-based interactions and culminating activities with at-sea scientists through an online forum. The project benefits from the involvement of a professional evaluator, and as the model is tested and refined, it may serve as a template for the inclusion of additional "extreme" earth systems. FLEXE is a partnership of the international GLOBE web- based education program and the NSF Ridge 2000 mid-ocean ridge and hydrothermal vent research program, and includes the expertise of the Center for Science and the Schools at Penn State University. International collaborators also include the InterRidge and ChEss international research programs.

A low cost, high precision extreme/harsh cold environment, autonomous sensor data gathering and transmission platform.

Science.gov (United States)

Chetty, S.; Field, L. A.

2014-12-01

SWIMS III, is a low cost, autonomous sensor data gathering platform developed specifically for extreme/harsh cold environments. Arctic ocean's continuing decrease of summer-time ice is related to rapidly diminishing multi-year ice due to the effects of climate change. Ice911 Research aims to develop environmentally inert materials that when deployed will increase the albedo, enabling the formation and/preservation of multi-year ice. SWIMS III's sophisticated autonomous sensors are designed to measure the albedo, weather, water temperature and other environmental parameters. This platform uses low cost, high accuracy/precision sensors, extreme environment command and data handling computer system using satellite and terrestrial wireless solution. The system also incorporates tilt sensors and sonar based ice thickness sensors. The system is light weight and can be deployed by hand by a single person. This presentation covers the technical, and design challenges in developing and deploying these platforms.

Improving diversity in cultures of bacteria from an extreme environment.

Science.gov (United States)

Vester, Jan Kjølhede; Glaring, Mikkel Andreas; Stougaard, Peter

2013-08-01

The ikaite columns in the Ikka Fjord in Greenland represent one of the few permanently cold and alkaline environments on Earth, and the interior of the columns is home to a bacterial community adapted to these extreme conditions. The community is characterized by low cell numbers imbedded in a calcium carbonate matrix, making extraction of bacterial cells and DNA a challenge and limiting molecular and genomic studies of this environment. To utilize this genetic resource, cultivation at high pH and low temperature was studied as a method for obtaining biomass and DNA from the fraction of this community that would not otherwise be amenable to genetic analyses. The diversity and community dynamics in mixed cultures of bacteria from ikaite columns was investigated using denaturing gradient gel electrophoresis and pyrosequencing of 16S rDNA. Both medium composition and incubation time influenced the diversity of the culture and many hitherto uncharacterized genera could be brought into culture by extended incubation time. Extended incubation time also gave rise to a more diverse community with a significant number of rare species not detected in the initial community.

CAN UPPER EXTREMITY FUNCTIONAL TESTS PREDICT THE SOFTBALL THROW FOR DISTANCE: A PREDICTIVE VALIDITY INVESTIGATION

Science.gov (United States)

Hanney, William J.; Kolber, Morey J.; Davies, George J.; Riemann, Bryan

2011-01-01

Introduction: Understanding the relationships between performance tests and sport activity is important to the rehabilitation specialist. The purpose of this study was two- fold: 1) To identify if relationships exist between tests of upper body strength and power (Single Arm Seated Shot Put, Timed Push-Up, Timed Modified Pull-Up, and The Davies Closed Kinetic Chain Upper Extremity Stability Test, and the softball throw for distance), 2) To determine which variable or group of variables best predicts the performance of a sport specific task (the softball throw for distance). Methods: One hundred eighty subjects (111 females and 69 males, aged 18-45 years) performed the 5 upper extremity tests. The Pearson product moment correlation and a stepwise regression were used to determine whether relationships existed between performance on the tests and which upper extremity test result best explained the performance on the softball throw for distance. Results: There were significant correlations (r=.33 to r=.70, p=0.001) between performance on all of the tests. The modified pull-up test was the best predictor of the performance on the softball throw for distance (r2= 48.7), explaining 48.7% of variation in performance. When weight, height, and age were added to the regression equation the r2 values increased to 64.5, 66.2, and 67.5 respectively. Conclusion: The results of this study indicate that several upper extremity tests demonstrate significant relationships with one another and with the softball throw for distance. The modified pull up test was the best predictor of performance on the softball throw for distance. PMID:21712942

Toxicity at the Edge of Life: A Review on Cyanobacterial Toxins from Extreme Environments

OpenAIRE

Cir?s, Samuel; Casero, Mar?a Cristina; Quesada, Antonio

2017-01-01

Cyanotoxins are secondary metabolites produced by cyanobacteria, of varied chemical nature and toxic effects. Although cyanobacteria thrive in all kinds of ecosystems on Earth even under very harsh conditions, current knowledge on cyanotoxin distribution is almost restricted to freshwaters from temperate latitudes. In this review, we bring to the forefront the presence of cyanotoxins in extreme environments. Cyanotoxins have been reported especially in polar deserts (both from the Arctic and ...

Predictive characterization of aging and degradation of reactor materials in extreme environments. Final report, December 20, 2013 - September 20, 2017

Energy Technology Data Exchange (ETDEWEB)

Qu, Jianmin [Northwestern Univ., Evanston, IL (United States)

2017-09-20

Understanding of reactor material behavior in extreme environments is vital not only to the development of new materials for the next generation nuclear reactors, but also to the extension of the operating lifetimes of the current fleet of nuclear reactors. To this end, this project conducted a suite of unique experimental techniques, augmented by a mesoscale computational framework, to understand and predict the long-term effects of irradiation, temperature, and stress on material microstructures and their macroscopic behavior. The experimental techniques and computational tools were demonstrated on two distinctive types of reactor materials, namely, Zr alloys and high-Cr martensitic steels. These materials are chosen as the test beds because they are the archetypes of high-performance reactor materials (cladding, wrappers, ducts, pressure vessel, piping, etc.). To fill the knowledge gaps, and to meet the technology needs, a suite of innovative in situ transmission electron microscopy (TEM) characterization techniques (heating, heavy ion irradiation, He implantation, quantitative small-scale mechanical testing, and various combinations thereof) were developed and used to elucidate and map the fundamental mechanisms of microstructure evolution in both Zr and Cr alloys for a wide range environmental boundary conditions in the thermal-mechanical-irradiation input space. Knowledge gained from the experimental observations of the active mechanisms and the role of local microstructural defects on the response of the material has been incorporated into a mathematically rigorous and comprehensive three-dimensional mesoscale framework capable of accounting for the compositional variation, microstructural evolution and localized deformation (radiation damage) to predict aging and degradation of key reactor materials operating in extreme environments. Predictions from this mesoscale framework were compared with the in situ TEM observations to validate the model.

Predictive characterization of aging and degradation of reactor materials in extreme environments. Final report, December 20, 2013 - September 20, 2017

International Nuclear Information System (INIS)

Qu, Jianmin

2017-01-01

Understanding of reactor material behavior in extreme environments is vital not only to the development of new materials for the next generation nuclear reactors, but also to the extension of the operating lifetimes of the current fleet of nuclear reactors. To this end, this project conducted a suite of unique experimental techniques, augmented by a mesoscale computational framework, to understand and predict the long-term effects of irradiation, temperature, and stress on material microstructures and their macroscopic behavior. The experimental techniques and computational tools were demonstrated on two distinctive types of reactor materials, namely, Zr alloys and high-Cr martensitic steels. These materials are chosen as the test beds because they are the archetypes of high-performance reactor materials (cladding, wrappers, ducts, pressure vessel, piping, etc.). To fill the knowledge gaps, and to meet the technology needs, a suite of innovative in situ transmission electron microscopy (TEM) characterization techniques (heating, heavy ion irradiation, He implantation, quantitative small-scale mechanical testing, and various combinations thereof) were developed and used to elucidate and map the fundamental mechanisms of microstructure evolution in both Zr and Cr alloys for a wide range environmental boundary conditions in the thermal-mechanical-irradiation input space. Knowledge gained from the experimental observations of the active mechanisms and the role of local microstructural defects on the response of the material has been incorporated into a mathematically rigorous and comprehensive three-dimensional mesoscale framework capable of accounting for the compositional variation, microstructural evolution and localized deformation (radiation damage) to predict aging and degradation of key reactor materials operating in extreme environments. Predictions from this mesoscale framework were compared with the in situ TEM observations to validate the model.

Optimization of multi-channel neutron focusing guides for extreme sample environments

International Nuclear Information System (INIS)

Di Julio, D D; Lelièvre-Berna, E; Andersen, K H; Bentley, P M; Courtois, P

2014-01-01

In this work, we present and discuss simulation results for the design of multichannel neutron focusing guides for extreme sample environments. A single focusing guide consists of any number of supermirror-coated curved outer channels surrounding a central channel. Furthermore, a guide is separated into two sections in order to allow for extension into a sample environment. The performance of a guide is evaluated through a Monte-Carlo ray tracing simulation which is further coupled to an optimization algorithm in order to find the best possible guide for a given situation. A number of population-based algorithms have been investigated for this purpose. These include particle-swarm optimization, artificial bee colony, and differential evolution. The performance of each algorithm and preliminary results of the design of a multi-channel neutron focusing guide using these methods are described. We found that a three-channel focusing guide offered the best performance, with a gain factor of 2.4 compared to no focusing guide, for the design scenario investigated in this work.

Extreme environments select for reproductive assurance: evidence from evening primroses (Oenothera).

Science.gov (United States)

Evans, Margaret E K; Hearn, David J; Theiss, Kathryn E; Cranston, Karen; Holsinger, Kent E; Donoghue, Michael J

2011-07-01

Competing evolutionary forces shape plant breeding systems (e.g. inbreeding depression, reproductive assurance). Which of these forces prevails in a given population or species is predicted to depend upon such factors as life history, ecological conditions, and geographical context. Here, we examined two such predictions: that self-compatibility should be associated with the annual life history or extreme climatic conditions. We analyzed data from a clade of plants remarkable for variation in breeding system, life history and climatic conditions (Oenothera, sections Anogra and Kleinia, Onagraceae). We used a phylogenetic comparative approach and Bayesian or hybrid Bayesian tests to account for phylogenetic uncertainty. Geographic information system (GIS)-based climate data and ecological niche modeling allowed us to quantify climatic conditions. Breeding system and reproductive life span are not correlated in Anogra and Kleinia. Instead, self-compatibility is associated with the extremes of temperature in the coldest part of the year and precipitation in the driest part of the year. In the 60 yr since this pattern was anticipated, this is the first demonstration of a relationship between the evolution of self-compatibility and climatic extremes. We discuss possible explanations for this pattern and possible implications with respect to anthropogenic climate change. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

Summary of Research Issues in Behavior and Performance in Isolated and Confined Extreme (ICE) Environments

Science.gov (United States)

Palinkas, Lawrence A.

2000-01-01

The papers presented in this section describe changes in behavior and performance in various isolated and confined extreme (ICE) environments, including Antarctic expeditions and research stations, space simulators and isolation chambers, and submarines. Each of these environments possesses characteristics that are in some way analogous to those found on long-duration space missions. Despite differences in length of mission, characteristics of mission personnel or crew, and characteristics in the physical environment, the various ICE environments described in this collection of papers appear to produce similar changes in behavior and performance. These changes include increased disturbances of mood, increased rates of psychiatric disorder, increased interpersonal tension, and a disruption of circadian rhythms. However, these environments do not inherently produce decrements in performance. Palinkas and colleagues suggest that prolonged exposure to the isolation and confinement in the Antarctic can actually have positive or "salutogenic" effects as well, evidenced by a decrease in mood disturbances and increase in performance measures.

PRELIMINARY BIOGEOCHEMICAL DATA ON MICROBIAL CARBONATOGENESIS IN ANCIENT EXTREME ENVIRONMENTS (KESS-KESS MOUNDS, MOROCCO

Directory of Open Access Journals (Sweden)

ADRIANO GUIDO

2013-03-01

Full Text Available The Devonian Kess-Kess mounds, cropping out in the Hamar Laghdad Ridge (SE Morocco, provide a useful case-study for understanding the relationships between the microbial metabolic activities and micrite precipitation in an extreme environment. Very fine dark and white wrinkled laminae record microbial activity and the geochemistry of the organic matter allows the  characterization of the source organisms. The biogeochemical characterization of extracted organic matter was performed through the functional group analyses by FT-IR Spectroscopy. FT-IR parameters indicate a marine origin and low thermal evolution for the organic material. The organic matter is characterized by the presence of stretching ?C=C vibrations attributable to alkene and/or unsaturated carboxylic acids. Preliminary analysis with GC-MS provides evidence for an autochthonous (extreme environment may have implications in astrobiological research considering the recent discovery of carbonate deposits on Mars. 

Four newly isolated fuselloviruses from extreme geothermal environments reveal unusual morphologies and a possible interviral recombination mechanism

DEFF Research Database (Denmark)

Redder, Peter; Peng, Xu; Brügger, Kim

2009-01-01

Spindle-shaped virus-like particles are abundant in extreme geothermal environments, from which five spindle-shaped viral species have been isolated to date. They infect members of the hyperthermophilic archaeal genus Sulfolobus, and constitute the Fuselloviridae, a family of double-stranded DNA...

Superior radiation-resistant nanoengineered austenitic 304L stainless steel for applications in extreme radiation environments.

Science.gov (United States)

Sun, C; Zheng, S; Wei, C C; Wu, Y; Shao, L; Yang, Y; Hartwig, K T; Maloy, S A; Zinkle, S J; Allen, T R; Wang, H; Zhang, X

2015-01-15

Nuclear energy provides more than 10% of electrical power internationally, and the increasing engagement of nuclear energy is essential to meet the rapid worldwide increase in energy demand. A paramount challenge in the development of advanced nuclear reactors is the discovery of advanced structural materials that can endure extreme environments, such as severe neutron irradiation damage at high temperatures. It has been known for decades that high dose radiation can introduce significant void swelling accompanied by precipitation in austenitic stainless steel (SS). Here we report, however, that through nanoengineering, ultra-fine grained (UFG) 304 L SS with an average grain size of ~100 nm, can withstand Fe ion irradiation at 500 °C to 80 displacements-per-atom (dpa) with moderate grain coarsening. Compared to coarse grained (CG) counterparts, swelling resistance of UFG SS is improved by nearly an order of magnitude and swelling rate is reduced by a factor of 5. M(23)C(6) precipitates, abundant in irradiated CG SS, are largely absent in UFG SS. This study provides a nanoengineering approach to design and discover radiation tolerant metallic materials for applications in extreme radiation environments.

Genomes in Turmoil: Frugality Drives Microbial Community Structure in Extremely Acidic Environments

Science.gov (United States)

Holmes, D. S.

2016-12-01

Extremely acidic environments (To gain insight into these issues, we have conducted deep bioinformatic analyses, including metabolic reconstruction of key assimilatory pathways, phylogenomics and network scrutiny of >160 genomes of acidophiles, including representatives from Archaea, Bacteria and Eukarya and at least ten metagenomes of acidic environments [Cardenas JP, et al. pp 179-197 in Acidophiles, eds R. Quatrini and D. B. Johnson, Caister Academic Press, UK (2016)]. Results yielded valuable insights into cellular processes, including carbon and nitrogen management and energy production, linking biogeochemical processes to organismal physiology. They also provided insight into the evolutionary forces that shape the genomic structure of members of acidophile communities. Niche partitioning can explain diversity patterns in rapidly changing acidic environments such as bioleaching heaps. However, in spatially and temporally homogeneous acidic environments genome flux appears to provide deeper insight into the composition and evolution of acidic consortia. Acidophiles have undergone genome streamlining by gene loss promoting mutual coexistence of species that exploit complementarity use of scarce resources consistent with the Black Queen hypothesis [Morris JJ et al. mBio 3: e00036-12 (2012)]. Acidophiles also have a large pool of accessory genes (the microbial super-genome) that can be accessed by horizontal gene transfer. This further promotes dependency relationships as drivers of community structure and the evolution of keystone species. Acknowledgements: Fondecyt 1130683; Basal CCTE PFB16

Weightless environment simulation test; Mujuryo simulation shiken

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, K.; Yamamoto, T.; Kato, F. [Kawasaki Heavy Industries, Ltd., Kobe (Japan)

1997-07-20

Kawasaki Heavy Industries, Ltd., delivered a Weightless Environment Test System (WETS) to National Space Development Agency of Japan in 1994. This system creates a weightless environment similar to that in space by balancing gravity and buoyancy in the water, and is constituted of a large water tank, facilities to supply air and cooling water to space suits worn in the water, etc. In this report, a weightless environment simulation test and the facilities to supply air and cooling water are described. In the weightless environment simulation test, the astronaut to undergo tests and training wears a space suit quite similar to the suit worn on the orbit, and performs EVA/IVA (extravehicular activities/intravehicular activities) around a JEM (Japanese Experimental Module) mockup installed in the water verifying JEM design specifications, preparing manuals for operations on the orbit, or receives basic space-related drill and training. An EVA weightless environment simulation test No. 3 was accomplished with success in January, 1997, when the supply of breathing water and cooling water to the space suit, etc., were carried out with safety and reliability. 2 refs., 8 figs., 2 tabs.

In-Situ Acoustic Measurements of Temperature Profile in Extreme Environments

Energy Technology Data Exchange (ETDEWEB)

Skliar, Mikhail [Univ. of Utah, Salt Lake City, UT (United States)

2015-03-31

A gasifier’s temperature is the primary characteristic that must be monitored to ensure its performance and the longevity of its refractory. One of the key technological challenges impacting the reliability and economics of coal and biomass gasification is the lack of temperature sensors that are capable of providing accurate, reliable, and long-life performance in an extreme gasification environment. This research has proposed, demonstrated, and validated a novel approach that uses a noninvasive ultrasound method that provides real-time temperature distribution monitoring across the refractory, especially the hot face temperature of the refractory. The essential idea of the ultrasound measurements of segmental temperature distribution is to use an ultrasound propagation waveguide across a refractory that has been engineered to contain multiple internal partial reflectors at known locations. When an ultrasound excitation pulse is introduced on the cold side of the refractory, it will be partially reflected from each scatterer in the US propagation path in the refractory wall and returned to the receiver as a train of partial echoes. The temperature in the corresponding segment can be determined based on recorded ultrasonic waveform and experimentally defined relationship between the speed of sound and temperature. The ultrasound measurement method offers a powerful solution to provide continuous real time temperature monitoring for the occasions that conventional thermal, optical and other sensors are infeasible, such as the impossibility of insertion of temperature sensor, harsh environment, unavailable optical path, and more. Our developed ultrasound system consists of an ultrasound engineered waveguide, ultrasound transducer/receiver, and data acquisition, logging, interpretation, and online display system, which is simple to install on the existing units with minimal modification on the gasifier or use with new units. This system has been successfully tested

Reliability of 4-meter and 10-meter walk tests after lower extremity surgery.

Science.gov (United States)

Unver, Bayram; Baris, Refik Hilmi; Yuksel, Ertugrul; Cekmece, Senol; Kalkan, Serpil; Karatosun, Vasfi

2017-12-01

To investigate the test-retest reliability of the 4-meter walk test (4 MWT) and 10-meter walk test (10 MWT) in patients undergoing lower extremity surgery during inpatient rehabilitation. In all, 102 patients with total hip arthroplasty (THA), total knee arthroplasty (TKA), lower extremity fracture (LEF) and soft tissue operation were recruited. Patients performed two 4 MWT and two 10 MWT trials on the same day. The same researcher performed all the measurements to avoid inter-rater variability. The 4 MWT and 10 MWT were shown to have excellent test-retest reliability. The ICCs for the 4 MWT and 10 MWT were found as 0.94 and 0.95, respectively. The SEMs for the 4 MWT and 10 MWT were 2.0 and 5.5 seconds, respectively. The smallest real difference at the 95% confidence level (SRD95) was 5.5 seconds for the 4 MWT and 12.2 seconds for 10 MWT and SRD95 percentage was 31.2 for the 4 MWT and 28.5 for the 10 MWT. Both the 4 MWT and the 10 MWT have excellent reliability in patients undergoing lower extremity surgery such as TKA, THA, LEF and soft tissue operation during inpatient rehabilitation. Clinicians and researchers can be confident that changes above the SRD95s for the different patient groups, for both sexes and with regard to weight-bearing status, represent a real clinical change in rehabilitation process. Implications for Rehabilitation The 4 MWT and the 10 MWT are simple methods and were also shown to be reliable measurement methods in many patient groups. This study illustrates that the test-retest reliability of the 4 MWT and 10 MWT are excellent in patients undergoing lower extremity surgery during inpatient rehabilitation (ICC: 0.94 for 4 MWT, ICC: 0.95 for 10 MWT). Clinicians and researchers can be confident that changes above the SRD95s for the different patient groups, for both sexes and with regard to weight-bearing status represent a real clinical change in rehabilitation process.

Transformers For Extreme Environments

Data.gov (United States)

National Aeronautics and Space Administration — Imagine a revolutionary way to remotely control the environment surrounding one or more roving vehicles exploring remote and unexplored areas of the Solar System,...

Biota and biomolecules in extreme environments on Earth: implications for life detection on Mars.

Science.gov (United States)

Aerts, Joost W; Röling, Wilfred F M; Elsaesser, Andreas; Ehrenfreund, Pascale

2014-10-13

The three main requirements for life as we know it are the presence of organic compounds, liquid water, and free energy. Several groups of organic compounds (e.g., amino acids, nucleobases, lipids) occur in all life forms on Earth and are used as diagnostic molecules, i.e., biomarkers, for the characterization of extant or extinct life. Due to their indispensability for life on Earth, these biomarkers are also prime targets in the search for life on Mars. Biomarkers degrade over time; in situ environmental conditions influence the preservation of those molecules. Nonetheless, upon shielding (e.g., by mineral surfaces), particular biomarkers can persist for billions of years, making them of vital importance in answering questions about the origins and limits of life on early Earth and Mars. The search for organic material and biosignatures on Mars is particularly challenging due to the hostile environment and its effect on organic compounds near the surface. In support of life detection on Mars, it is crucial to investigate analogue environments on Earth that resemble best past and present Mars conditions. Terrestrial extreme environments offer a rich source of information allowing us to determine how extreme conditions affect life and molecules associated with it. Extremophilic organisms have adapted to the most stunning conditions on Earth in environments with often unique geological and chemical features. One challenge in detecting biomarkers is to optimize extraction, since organic molecules can be low in abundance and can strongly adsorb to mineral surfaces. Methods and analytical tools in the field of life science are continuously improving. Amplification methods are very useful for the detection of low concentrations of genomic material but most other organic molecules are not prone to amplification methods. Therefore, a great deal depends on the extraction efficiency. The questions "what to look for", "where to look", and "how to look for it" require more of

Biota and Biomolecules in Extreme Environments on Earth: Implications for Life Detection on Mars

Directory of Open Access Journals (Sweden)

Joost W. Aerts

2014-10-01

Full Text Available The three main requirements for life as we know it are the presence of organic compounds, liquid water, and free energy. Several groups of organic compounds (e.g., amino acids, nucleobases, lipids occur in all life forms on Earth and are used as diagnostic molecules, i.e., biomarkers, for the characterization of extant or extinct life. Due to their indispensability for life on Earth, these biomarkers are also prime targets in the search for life on Mars. Biomarkers degrade over time; in situ environmental conditions influence the preservation of those molecules. Nonetheless, upon shielding (e.g., by mineral surfaces, particular biomarkers can persist for billions of years, making them of vital importance in answering questions about the origins and limits of life on early Earth and Mars. The search for organic material and biosignatures on Mars is particularly challenging due to the hostile environment and its effect on organic compounds near the surface. In support of life detection on Mars, it is crucial to investigate analogue environments on Earth that resemble best past and present Mars conditions. Terrestrial extreme environments offer a rich source of information allowing us to determine how extreme conditions affect life and molecules associated with it. Extremophilic organisms have adapted to the most stunning conditions on Earth in environments with often unique geological and chemical features. One challenge in detecting biomarkers is to optimize extraction, since organic molecules can be low in abundance and can strongly adsorb to mineral surfaces. Methods and analytical tools in the field of life science are continuously improving. Amplification methods are very useful for the detection of low concentrations of genomic material but most other organic molecules are not prone to amplification methods. Therefore, a great deal depends on the extraction efficiency. The questions “what to look for”, “where to look”, and “how to

Development and performance test of a system available for generating multiple extreme conditions for neutron scattering experiments

International Nuclear Information System (INIS)

Kawano, Shinji; Fukui, Susumu; Moriai, Atsushi; Ohtomo, Akitoshi; Ichimura, Shigeki; Onodera, Akifumi; Amita, F.; Katano, Susumu

1998-01-01

We have developed unique system available for controlling sample environment during the neutron scattering experiments. The system can simultaneously generate triple extreme conditions of low temperature, high magnetic field and high pressure. The system consists of: (i) a liquid-helium cryostat variable for sample temperature from 1.7 K to 200 K, (ii) a superconducting magnet providing a vertical field up to ±5 T with an antisymmetric split-coil geometry for polarized-beam experiments, and (iii) a non-magnetic piston-cylinder high-pressure cell designed with the aim of generating hydrostatic pressure up to 2.5 GPa. In the presentation, we will report the outline of the system and some results of performance tests at KURRI and JRR-3M of JAERI. (author)

Prediction of software operational reliability using testing environment factors

International Nuclear Information System (INIS)

Jung, Hoan Sung; Seong, Poong Hyun

1995-01-01

For many years, many researches have focused on the quantification of software reliability and there are many models developed to quantify software reliability. Most software reliability models estimate the reliability with the failure data collected during the test assuming that the test environments well represent the operation profile. The experiences show that the operational reliability is higher than the test reliability User's interest is on the operational reliability rather than on the test reliability, however. With the assumption that the difference in reliability results from the change of environment, testing environment factors comprising the aging factor and the coverage factor are defined in this study to predict the ultimate operational reliability with the failure data. It is by incorporating test environments applied beyond the operational profile into testing environment factors. The application results are close to the actual data

Silicon-Carbide Power MOSFET Performance in High Efficiency Boost Power Processing Unit for Extreme Environments

Science.gov (United States)

Ikpe, Stanley A.; Lauenstein, Jean-Marie; Carr, Gregory A.; Hunter, Don; Ludwig, Lawrence L.; Wood, William; Del Castillo, Linda Y.; Fitzpatrick, Fred; Chen, Yuan

2016-01-01

Silicon-Carbide device technology has generated much interest in recent years. With superior thermal performance, power ratings and potential switching frequencies over its Silicon counterpart, Silicon-Carbide offers a greater possibility for high powered switching applications in extreme environment. In particular, Silicon-Carbide Metal-Oxide- Semiconductor Field-Effect Transistors' (MOSFETs) maturing process technology has produced a plethora of commercially available power dense, low on-state resistance devices capable of switching at high frequencies. A novel hard-switched power processing unit (PPU) is implemented utilizing Silicon-Carbide power devices. Accelerated life data is captured and assessed in conjunction with a damage accumulation model of gate oxide and drain-source junction lifetime to evaluate potential system performance at high temperature environments.

Predictors of Behavior and Performance in Extreme Environments: The Antarctic Space Analogue Program

Science.gov (United States)

Palinkas, Lawrence A.; Gunderson, E K. Eric; Holland, A. W.; Miller, Christopher; Johnson, Jeffrey C.

2000-01-01

To determine which, if any, characteristics should be incorporated into a select-in approach to screening personnel for long-duration spaceflight, we examined the influence of crewmember social/ demographic characteristics, personality traits, interpersonal needs, and characteristics of station physical environments on performance measures in 657 American men who spent an austral winter in Antarctica between 1963 and 1974. During screening, subjects completed a Personal History Questionnaire which obtained information on social and demographic characteristics, the Deep Freeze Opinion Survey which assessed 5 different personality traits, and the Fundamental Interpersonal Relations Orientation-Behavior (FIRO-B) Scale which measured 6 dimensions of interpersonal needs. Station environment included measures of crew size and severity of physical environment. Performance was assessed on the basis of combined peer-supervisor evaluations of overall performance, peer nominations of fellow crewmembers who made ideal winter-over candidates, and self-reported depressive symptoms. Social/demographic characteristics, personality traits, interpersonal needs, and characteristics of station environments collectively accounted for 9-17% of the variance in performance measures. The following characteristics were significant independent predictors of more than one performance measure: military service, low levels of neuroticism, extraversion and conscientiousness, and a low desire for affection from others. These results represent an important first step in the development of select-in criteria for personnel on long-duration missions in space and other extreme environments. These criteria must take into consideration the characteristics of the environment and the limitations they place on meeting needs for interpersonal relations and task performance, as well as the characteristics of the individuals and groups who live and work in these environments.

UAS-NAS Flight Test Series 3: Test Environment Report

Science.gov (United States)

Hoang, Ty; Murphy, Jim; Otto, Neil

2016-01-01

The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration in the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability (SSI), Human Systems Integration (HSI), and Communications (Comm), and Certification to support reducing the barriers of UAS access to the NAS. This research is broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Detect and Avoid (DAA) performance standards, command and control performance standards, and human systems integration. The focus of Test Infrastructure is to enable development and validation of airspace integration procedures and performance standards, including integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project will develop an adaptable, scalable, and schedulable relevant test environment capable of evaluating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project is conducting a series of human-in-the-loop (HITL) and flight test activities that integrate key concepts, technologies and/or procedures in a relevant air traffic environment. Each of the integrated events will build on the technical achievements, fidelity, and

Prediction of safety critical software operational reliability from test reliability using testing environment factors

International Nuclear Information System (INIS)

Jung, Hoan Sung; Seong, Poong Hyun

1999-01-01

It has been a critical issue to predict the safety critical software reliability in nuclear engineering area. For many years, many researches have focused on the quantification of software reliability and there have been many models developed to quantify software reliability. Most software reliability models estimate the reliability with the failure data collected during the test assuming that the test environments well represent the operation profile. User's interest is however on the operational reliability rather than on the test reliability. The experiences show that the operational reliability is higher than the test reliability. With the assumption that the difference in reliability results from the change of environment, from testing to operation, testing environment factors comprising the aging factor and the coverage factor are developed in this paper and used to predict the ultimate operational reliability with the failure data in testing phase. It is by incorporating test environments applied beyond the operational profile into testing environment factors. The application results show that the proposed method can estimate the operational reliability accurately. (Author). 14 refs., 1 tab., 1 fig

Design, implementation and test of the XSC extreme shape controller in JET

International Nuclear Information System (INIS)

Albanese, R.; Ambrosino, G.; Ariola, M.; Cenedese, A.; Crisanti, F.; Tommasi, G. De; Mattei, M.; Piccolo, F.; Pironti, A.; Sartori, F.; Villone, F.

2005-01-01

A new model-based plasma current and shape controller has been set up and tested on the JET Tokamak with the existing active circuits and control. The installation has been carried out without causing any interference to the plasma operation and without requiring a long commissioning time. Eventually, the new controller was used on really extremely shaped internal transport barrier experiments at high poloidal beta and in the presence of quite large variations of the plasma current density profile (variation range Δβ pol up to 1.5 and Δl i up to 0.5). The extreme shape controller (XSC) controller architecture and philosophy also offer new interesting opportunities, e.g., the separatrix sweeping on the divertor plates without significantly affecting the overall plasma shape, and the possibility of improving the overall tokamak performance via combined control of plasma shape, current and profile. The adopted methodology constitutes also an important test bed for feedback control strategies of ITER relevance

Composite Materials under Extreme Radiation and Temperature Environments of the Next Generation Nuclear Reactors

International Nuclear Information System (INIS)

Simos, N.

2011-01-01

In the nuclear energy renaissance, driven by fission reactor concepts utilizing very high temperatures and fast neutron spectra, materials with enhanced performance that exceeds are expected to play a central role. With the operating temperatures of the Generation III reactors bringing the classical reactor materials close to their performance limits there is an urgent need to develop and qualify new alloys and composites. Efforts have been focused on the intricate relations and the high demands placed on materials at the anticipated extreme states within the next generation fusion and fission reactors which combine high radiation fluxes, elevated temperatures and aggressive environments. While nuclear reactors have been in operation for several decades, the structural materials associated with the next generation options need to endure much higher temperatures (1200 C), higher neutron doses (tens of displacements per atom, dpa), and extremely corrosive environments, which are beyond the experience on materials accumulated to-date. The most important consideration is the performance and reliability of structural materials for both in-core and out-of-core functions. While there exists a great body of nuclear materials research and operating experience/performance from fission reactors where epithermal and thermal neutrons interact with materials and alter their physio-mechanical properties, a process that is well understood by now, there are no operating or even experimental facilities that will facilitate the extreme conditions of flux and temperature anticipated and thus provide insights into the behaviour of these well understood materials. Materials, however, still need to be developed and their interaction and damage potential or lifetime to be quantified for the next generation nuclear energy. Based on material development advances, composites, and in particular ceramic composites, seem to inherently possess properties suitable for key functions within the

Adaptation strategies of endolithic chlorophototrophs to survive the hyperarid and extreme solar radiation environment of the Atacama Desert

Czech Academy of Sciences Publication Activity Database

Wierzchos, J.; DiRuggiero, J.; Vítek, Petr; Artieda, O.; Souza-Egipsy, V.; Škaloud, P.; Tisza, M.; Davilla, A. F.; Vilchez, C.; Garbayo, I.; Ascaso, C.

2015-01-01

Roč. 6, č. 934 (2015), s. 1-17 ISSN 1664-302X R&D Projects: GA MŠk EE2.3.20.0246 Institutional support: RVO:67179843 Keywords : Atacama Desert * carotenoids * endolithic chlorophototrophs * extreme environment * gypsum * scytonemin Subject RIV: EF - Botanics Impact factor: 4.165, year: 2015

An Overview of 2014 SBIR Phase I and Phase II Materials Structures for Extreme Environments

Science.gov (United States)

Nguyen, Hung D.; Steele, Gynelle C.; Morris, Jessica R.

2015-01-01

NASA's Small Business Innovation Research (SBIR) program focuses on technological innovation by investing in development of innovative concepts and technologies to help NASA mission directorates address critical research needs for Agency programs. This report highlights nine of the innovative SBIR 2014 Phase I and Phase II projects that emphasize one of NASA Glenn Research Center's six core competencies-Materials and Structures for Extreme Environments. The technologies cover a wide spectrum of applications such as high temperature environmental barrier coating systems, deployable space structures, solid oxide fuel cells, and self-lubricating hard coatings for extreme temperatures. Each featured technology describes an innovation, technical objective, and highlights NASA commercial and industrial applications. This report provides an opportunity for NASA engineers, researchers, and program managers to learn how NASA SBIR technologies could help their programs and projects, and lead to collaborations and partnerships between the small SBIR companies and NASA that would benefit both.

TRACING MOLECULAR GAS MASS IN EXTREME EXTRAGALACTIC ENVIRONMENTS: AN OBSERVATIONAL STUDY

International Nuclear Information System (INIS)

Zhu Ming; Papadopoulos, Padeli P.; Xilouris, Emmanuel M.; Kuno, Nario; Lisenfeld, Ute

2009-01-01

We present a new observational study of the 12 CO(1-0) line emission as an H 2 gas mass tracer under extreme conditions in extragalactic environments. Our approach is to study the full neutral interstellar medium (H 2 , H I, and dust) of two galaxies whose bulk interstellar medium (ISM) resides in environments that mark (and bracket) the excitation extremes of the ISM conditions found in infrared luminous galaxies, the starburst NGC 3310, and the quiescent spiral NGC 157. Our study maintains a robust statistical notion of the so-called X = N(H 2 )/I CO factor (i.e., a large ensemble of clouds is involved) while exploring its dependence on the very different average ISM conditions prevailing within these two systems. These are constrained by fully sampled 12 CO(3-2) and 12 CO(1-0) observations, at a matched beam resolution of half-power beam width ∼15'', obtained with the James Clerk Maxwell Telescope (JCMT) on Mauna Kea (Hawaii) and the 45 m telescope of the Nobeyama Radio Observatory in Japan, combined with sensitive 850 μm and 450 μm dust emission and H I interferometric images which allow a complete view of all the neutral ISM components. Complementary 12 CO(2-1) observations were obtained with the JCMT toward the center of the two galaxies. We found an X factor varying by a factor of 5 within the spiral galaxy NGC 157 and about two times lower than the Galactic value in NGC 3310. In addition, the dust emission spectrum in NGC 3310 shows a pronounced submillimeter 'excess'. We tried to fit this excess by a cold dust component but very low temperatures were required (T C ∼ 5-11 K) with a correspondingly low gas-to-dust mass ratio of ∼5-43. We furthermore show that it is not possible to maintain the large quantities of dust required at these low temperatures in this starburst galaxy. Instead, we conclude that the dust properties need to be different from Galactic dust in order to fit the submillimeter 'excess'. We show that the dust spectral energy

Automated corrosion fatigue crack growth testing in pressurized water environments

International Nuclear Information System (INIS)

Ceschini, L.J.; Liaw, P.K.; Rudd, G.E.; Logsdon, W.A.

1984-01-01

This paper describes in detail a novel approach to construct a test facility for developing corrosion fatigue crack growth rate (FCGR) properties in aggressive environments. The environment studied is that of a pressurized water reactor (PWR) at 288 0 C (550 0 F) and 13.8 MPa (200 psig). To expedite data generation, each chamber was designed to accommodate two test specimens. A common water recirculation and pressurization system was employed to service two test chambers. Thus, four fatigue crack propagation rate tests could be conducted simultaneously in the pressurized water environment. The data analysis was automated to minimize the typically high labor costs associated with corrosion fatigue crack propagation testing. Verification FCGR tests conducted on an ASTM A469 rotor steel in a room temperature air environment as well as actual PWR environment FCGR tests performed on an ASTM A533 Grade B Class 2 pressure vessel steel demonstrated that the dual specimen test facility is an excellent system for developing the FCGR properties of materials in adverse environments

How Do Modern Extreme Hydrothermal Environments Inform the Identification of Martian Habitability? The Case of the El Tatio Geyser Field

Directory of Open Access Journals (Sweden)

Roberto Barbieri

2014-11-01

Full Text Available Despite the success in knowledge gained by the Mars missions in the last two decades, the search for traces of life on Mars is still in progress. The reconstruction of (paleo- environments on Mars have seen a dramatic increase, in particular with regard to the potentially habitable conditions, and it is now possible to recognize a significant role to subaerial hydrothermal processes. For this reason, and because the conditions of the primordial Earth—when these extreme environments had to be common—probably resembled Mars during its most suitable time to host life, research on terrestrial extreme hydrothermal habitats may assist in understanding how to recognize life on Mars. A number of geological and environmental reasons, and logistics opportunities, make the geothermal field of El Tatio, in the Chilean Andes an ideal location to study.

Extremely environment-hard and low work function transfer-mold field emitter arrays

Energy Technology Data Exchange (ETDEWEB)

Nakamoto, Masayuki, E-mail: m-nakamoto@rie.shizuoka.ac.jp [Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, Shizuoka 432-8011 (Japan); Moon, Jonghyun [Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, Shizuoka 432-8011 (Japan)

2013-06-15

Extremely environment-hard and low work function field-emitter arrays (FEAs) were fabricated by a transfer-mold emitter fabrication method to produce highly reliable vacuum nanoelectronic devices able to operate stably at low voltage in highly oxidizing atmospheres. Amorphous carbon (a-C) having a work function of 3.6 eV and sp{sup 3} fraction of 85.6% prepared by plasma-enhanced chemical vapor deposition was used as the emitter material. The field-emission characteristics of the obtained transfer-mold FEAs strongly depended on their work function and morphology. The environment-hard characteristics of the transfer-mold a-C FEAs were compared with those of the transfer-mold titanium nitride FEAs and nickel FEAs. X-ray photoelectron spectroscopy was used to confirm the stable chemical states of the FEAs after oxygen radical treatment. The small amount of material oxidized (6.3%) at the surface of the a-C FEAs compared with 11.8% for the TiN-FEAs and 39.0% for Ni FEAs after oxygen radical treatment explained their almost constant work function in oxidizing atmospheres. The emission fluctuation rates of transfer-mold a-C FEAs without resistive layers under in situ radical treatment were as low as ±5.0%, compared with 5–100% for conventional FEAs with resistive layers not under highly oxidizing atmospheres. Therefore, the present environment-hard and low work function transfer-mold a-C FEAs are expected to be useful for reliable vacuum nanoelectronic devices.

Effects of service environments on aluminum-brazed titanium (ABTi)

Science.gov (United States)

Cotton, W. L.

1978-01-01

Aluminum brazed titanium (ABTi) structures were evaluated during prolonged exposure to extreme environments: elevated temperature exposure to airline service fluids, hydraulic fluid, and seawater, followed by laboratory corrosion tests. Solid-face and perforated face honeycomb sandwich panel specimens, stressed panel assemblies, and faying surface brazed joints were tested. The corrosion resistance of ABTi is satisfactory for commercial airline service. Unprotected ABTi proved inherently resistant to attack by all of the extreme service aircraft environments except: seawater at 700 K (800 F) and above, dripping phosphate ester hydraulic fluid at 505 K (450 F), and a marine environment at ambient temperature. The natural oxides and deposits present on titanium surfaces in airline service provide protection against hot salt corrosion pitting. Coatings are required to protect titanium dripping phosphate ester fluid at elevated temperatures and to protect exposed acoustic honeycomb parts against corrosion in a marine environment.

Microbial ecology of extreme environments: Antarctic yeasts and growth in substrate-limited habitats

Science.gov (United States)

Vishniac, H. S.

1984-01-01

An extreme environment is by definition one with a depauperate biota. While the Ross Desert is by no means homogeneous, the most exposed and arid habitats, soils in the unglaciated high valleys, do indeed contain a very sparse biota of low diversity. So sparse that the natives could easily be outnumbered by airborne exogenous microbes. Native biota must be capable of overwintering as well as growing in the high valley summer. Tourists may undergo a few divisions before contributing their enzymes and, ultimately, elements to the soil - or may die before landing. The simplest way to demonstrate the indigenicity of a particular microbe is therefore to establish unique distribution; occurrence only in the habitat in question precludes foreign origin.

Solar Weather Ice Monitoring Station (SWIMS). A low cost, extreme/harsh environment, solar powered, autonomous sensor data gathering and transmission system

Science.gov (United States)

Chetty, S.; Field, L. A.

2013-12-01

The Arctic ocean's continuing decrease of summer-time ice is related to rapidly diminishing multi-year ice due to the effects of climate change. Ice911 Research aims to develop environmentally respectful materials that when deployed will increase the albedo, enhancing the formation and/preservation of multi-year ice. Small scale deployments using various materials have been done in Canada, California's Sierra Nevada Mountains and a pond in Minnesota to test the albedo performance and environmental characteristics of these materials. SWIMS is a sophisticated autonomous sensor system being developed to measure the albedo, weather, water temperature and other environmental parameters. The system (SWIMS) employs low cost, high accuracy/precision sensors, high resolution cameras, and an extreme environment command and data handling computer system using satellite and terrestrial wireless communication. The entire system is solar powered with redundant battery backup on a floating buoy platform engineered for low temperature (-40C) and high wind conditions. The system also incorporates tilt sensors, sonar based ice thickness sensors and a weather station. To keep the costs low, each SWIMS unit measures incoming and reflected radiation from the four quadrants around the buoy. This allows data from four sets of sensors, cameras, weather station, water temperature probe to be collected and transmitted by a single on-board solar powered computer. This presentation covers the technical, logistical and cost challenges in designing, developing and deploying these stations in remote, extreme environments. Image captured by camera #3 of setting sun on the SWIMS station One of the images captured by SWIMS Camera #4

Evaluation of the Physiological Challenges in Extreme Environments: Implications for Enhanced Training, Operational Performance and Sex-Specific Responses

Science.gov (United States)

2017-10-01

Operational Performance and Sex -Specific Responses PRINCIPAL INVESTIGATOR: Brent C. Ruby CONTRACTING ORGANIZATION: The University of Montana Missoula...Implications for Enhanced Training, Operational Performance and Sex -Specific Responses 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...Evaluation of the physiological challenges in extreme environments: Implications for enhanced training, operational performance and sex -specific

Vegetation Cover and Furrow Erosion due to Extreme Rain Events in Semiarid Environments

Directory of Open Access Journals (Sweden)

Belén Cárceles-Rodríguez

2017-05-01

Full Text Available The conservation of the soil resource in semi-arid environments is one of the major challenges of agricultural systems, particularly in the Mediterranean region. In the present study, two types of soil management were compared: minimum tillage (ML and minimum tillage with spontaneous vegetation cover (MLVE. The comparison was conducted in a rainfed almond plantation at slope (35%, under an extraordinary event in 2015 (91.3 mm and EI30 of 2,719.89 mm ha-1 h-1. In this situation in MLVE plots, the development of furrows in contrast to ML were not recorded; the total soil loss was more than 12 times lower than that recorded in the latter. This fact demonstrated the effectiveness of the vegetal cover in the protection of the agricultural soil against the erosion during extreme events. Also, for ML management, furrow erosion represented more than 60% of the total soil loss, demonstrating the dominance of this type of erosion. Finally, it should be noted that this event represents the almost total loss of soil recorded in the experimental plots during the period 2012-2015; and this consequently shows the significant impact of extreme events on erosion rates in the Mediterranean region.

Extreme Environment High Temperature Communication Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The purpose of this project is to develop and demonstrate a communications system capable of operation at extreme temperatures and pressures in hostile and corrosive...

Magnetic Logic Circuits for Extreme Environments, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The program aims to demonstrate a new genre of all-magnetic logic circuits which are radiation-tolerant and capable of reliable operation in extreme environmental...

Effects of aquatic PNF lower extremity patterns on balance and ADL of stroke patients.

Science.gov (United States)

Kim, Eun-Kyung; Lee, Dong-Kyu; Kim, Young-Mi

2015-01-01

[Purpose] This study investigated the effect of aquatic proprioceptive neuromuscular facilitation (PNF) patterns in the lower extremity on balance and activities of daily living (ADL) in stroke patients. [Subjects] Twenty poststroke participants were randomly assigned to an experimental group (n = 10) or a control group (n = 10). The experimental group performed lower extremity patterns in an aquatic environment, and the control group performed lower extremity patterns on the ground. Both exercises were conducted for 30 minutes/day, 5 days/week for 6 weeks. Balance was measured with the Berg Balance Scale (BBS), Timed Up and Go Test (TUGT), Functional Reach Test (FRT), and One Leg Stand Test (OLST). Activities of daily living were measured with the Functional Independence Measure (FIM). A paired t-test was used to measure pre- and post-experiment differences, and an independent t-test was used to measure between-group differences. [Results] The experimental and control groups showed significant differences for all pre- and post-experiment variables. In the between-group comparison, the experimental group was significantly difference from the control group. [Conclusion] These results indicate that performing aquatic proprioceptive neuromuscular facilitation patterns in the lower extremity enhances balance and ADL in stroke patients.

The Reliability of Quality of Upper Extremity Skills Test in Children with Cerebral Palsy

Directory of Open Access Journals (Sweden)

Nazila Akbar-Fahimi

2012-01-01

Full Text Available Objective: The aim of this study was to survey the reliability of Intra-rater and Inter-rater with and without video camera assessment in children with spastic cerebral palsy. Materials & Methods: In this cross-sectional study, we validate the Quality of Upper Extremity Skill Test questionnaire. Fifty children with hemiplegia aged 19 to 95 months (mean age 61.31 ± 25.7 month were enrolled in our study using non random available approach. After obtaining parents’ consent, intra-rater assessment was performed in one session and intera rater assessment with camera after 10 days. Then, the third examiner did the reassessment using film observation of 46 children from 50. Spearman correlation for survey the reliability of intra-rater & inter rater with & without video recording assessment & gross motor function classification system 66 for determined functionality of child were used. Results: Intra-rater correlation was 0.774-0.996, Inter-rater correlation was 0.663-0.998 and correlation for video camera assessment was 0.710-0.974 for the first and third evaluation and 0.652-0.938 for second and third evaluation. P value for sub scales and total score was P<0.01. Conclusion: There is a high correlation in Intra rater and inter rater assessment with and without video recording in Quality of Upper Extremity Skill Test in children with cerebral palsy. So that it can be used as a reliable test to evaluate Quality of Upper Extremity Skills in these children.

NASA Extreme Environment Mission Operations: Science Operations Development for Human Exploration

Science.gov (United States)

Bell, Mary S.

2014-01-01

The purpose of NASA Extreme Environment Mission Operations (NEEMO) mission 16 in 2012 was to evaluate and compare the performance of a defined series of representative near-Earth asteroid (NEA) extravehicular activity (EVA) tasks under different conditions and combinations of work systems, constraints, and assumptions considered for future human NEA exploration missions. NEEMO 16 followed NASA's 2011 Desert Research and Technology Studies (D-RATS), the primary focus of which was understanding the implications of communication latency, crew size, and work system combinations with respect to scientific data quality, data management, crew workload, and crew/mission control interactions. The 1-g environment precluded meaningful evaluation of NEA EVA translation, worksite stabilization, sampling, or instrument deployment techniques. Thus, NEEMO missions were designed to provide an opportunity to perform a preliminary evaluation of these important factors for each of the conditions being considered. NEEMO 15 also took place in 2011 and provided a first look at many of the factors, but the mission was cut short due to a hurricane threat before all objectives were completed. ARES Directorate (KX) personnel consulted with JSC engineers to ensure that high-fidelity planetary science protocols were incorporated into NEEMO mission architectures. ARES has been collaborating with NEEMO mission planners since NEEMO 9 in 2006, successively building upon previous developments to refine science operations concepts within engineering constraints; it is expected to continue the collaboration as NASA's human exploration mission plans evolve.

Prediction of software operational reliability using testing environment factor

International Nuclear Information System (INIS)

Jung, Hoan Sung

1995-02-01

Software reliability is especially important to customers these days. The need to quantify software reliability of safety-critical systems has been received very special attention and the reliability is rated as one of software's most important attributes. Since the software is an intellectual product of human activity and since it is logically complex, the failures are inevitable. No standard models have been established to prove the correctness and to estimate the reliability of software systems by analysis and/or testing. For many years, many researches have focused on the quantification of software reliability and there are many models developed to quantify software reliability. Most software reliability models estimate the reliability with the failure data collected during the test assuming that the test environments well represent the operation profile. User's interest is on the operational reliability rather than on the test reliability, however. The experiences show that the operational reliability is higher than the test reliability. With the assumption that the difference in reliability results from the change of environment, testing environment factor comprising the aging factor and the coverage factor are defined in this work to predict the ultimate operational reliability with the failure data. It is by incorporating test environments applied beyond the operational profile into testing environment factor Test reliability can also be estimated with this approach without any model change. The application results are close to the actual data. The approach used in this thesis is expected to be applicable to ultra high reliable software systems that are used in nuclear power plants, airplanes, and other safety-critical applications

Complex Plasma Research Under Extreme Conditions

International Nuclear Information System (INIS)

Ishihara, Osamu

2008-01-01

Complex plasma research under extreme conditions is described. The extreme conditions include low-dimensionality for self-organized structures of dust particles, dust magnetization in high magnetic field, criticality in phase transition, and cryogenic environment for Coulomb crystals and dust dynamics.

Study on the interaction mechanism between the special geological environment and their extreme geo-microbes in Dagang Oilfield by combined methods

Science.gov (United States)

Yao, Jun

2010-05-01

Geo-microbes and their function were widespread ever since life appeared on the earth. Geo-microbiological process has left a rich and colorful material record in the geological body of earth, the most critical record of which is all sorts of organic hieroglyph and various forms of organic matter derived from bio-organisms, and oil field is the most ideal geological location to preserve these organic matters. It have already produced or might produce petroleum and natural gas sedimentary rocks under natural conditions, also known as olefiant (gas) rock or the parent rock, which is the product of the interaction between the life-system and earth environmental system in the specific geological conditions and integrate the whole microbial ecosystem in the geological time. The microbial community under extreme geological environment of Dagang Oilfield is relatively simple, therefore it is quite easy to investigate the special relationship between geo-microbes and biogeochemistry. We have mastered a large number of information related with the geological condition and biological species of Dagang Oilfield; what's more we also have isolated a number of archimycetes strains with different extremophiles capacity from the core samples collected in the Dagang oil field. At present, we are to proceed with the cooperative research at Environment School of Yale University and Institute of the Earth's biosphere using these strains. In the future, we will work together to carry out geological surveys in the field using international first-class equipment and methods and study the geological environment of Dagang Oilfield utilizing isotope techniques and mineral phase analysis method. Meanwhile we are going to undertake the on-line monitoring of the overall microbial activity of these collected geological samples, the specific metabolic activity of these extreme strains of microorganisms and the biomarkers produced during their metabolic processes under laboratory conditions

Correlating Microbial Diversity Patterns with Geochemistry in an Extreme and Heterogeneous Environment of Mine Tailings

Science.gov (United States)

Liu, Jun; Hua, Zheng-Shuang; Chen, Lin-Xing; Kuang, Jia-Liang; Li, Sheng-Jin; Shu, Wen-Sheng

2014-01-01

Recent molecular surveys have advanced our understanding of the forces shaping the large-scale ecological distribution of microbes in Earth's extreme habitats, such as hot springs and acid mine drainage. However, few investigations have attempted dense spatial analyses of specific sites to resolve the local diversity of these extraordinary organisms and how communities are shaped by the harsh environmental conditions found there. We have applied a 16S rRNA gene-targeted 454 pyrosequencing approach to explore the phylogenetic differentiation among 90 microbial communities from a massive copper tailing impoundment generating acidic drainage and coupled these variations in community composition with geochemical parameters to reveal ecological interactions in this extreme environment. Our data showed that the overall microbial diversity estimates and relative abundances of most of the dominant lineages were significantly correlated with pH, with the simplest assemblages occurring under extremely acidic conditions and more diverse assemblages associated with neutral pHs. The consistent shifts in community composition along the pH gradient indicated that different taxa were involved in the different acidification stages of the mine tailings. Moreover, the effect of pH in shaping phylogenetic structure within specific lineages was also clearly evident, although the phylogenetic differentiations within the Alphaproteobacteria, Deltaproteobacteria, and Firmicutes were attributed to variations in ferric and ferrous iron concentrations. Application of the microbial assemblage prediction model further supported pH as the major factor driving community structure and demonstrated that several of the major lineages are readily predictable. Together, these results suggest that pH is primarily responsible for structuring whole communities in the extreme and heterogeneous mine tailings, although the diverse microbial taxa may respond differently to various environmental conditions

Metaorganisms in extreme environments: do microbes play a role in organismal adaptation?

KAUST Repository

Bang, Corinna

2018-02-15

From protists to humans, all animals and plants are inhabited by microbial organisms. There is an increasing appreciation that these resident microbes influence the fitness of their plant and animal hosts, ultimately forming a metaorganism consisting of a uni- or multicellular host and a community of associated microorganisms. Research on host–microbe interactions has become an emerging cross-disciplinary field. In both vertebrates and invertebrates a complex microbiome confers immunological, metabolic and behavioural benefits; conversely, its disturbance can contribute to the development of disease states. However, the molecular and cellular mechanisms controlling the interactions within a metaorganism are poorly understood and many key interactions between the associated organisms remain unknown. In this perspective article, we outline some of the issues in interspecies interactions and in particular address the question of how metaorganisms react and adapt to inputs from extreme environments such as deserts, the intertidal zone, oligothrophic seas, and hydrothermal vents.

Metaorganisms in extreme environments: do microbes play a role in organismal adaptation?

KAUST Repository

Bang, Corinna; Dagan, Tal; Deines, Peter; Dubilier, Nicole; Duschl, Wolfgang J.; Fraune, Sebastian; Hentschel, Ute; Hirt, Heribert; Hü lter, Nils; Lachnit, Tim; Picazo, Devani; Pita, Lucia; Pogoreutz, Claudia; Radecker, Nils; Saad, Maged; Schmitz, Ruth A.; Schulenburg, Hinrich; Voolstra, Christian R.; Weiland-Brä uer, Nancy; Ziegler, Maren; Bosch, Thomas C.G.

2018-01-01

From protists to humans, all animals and plants are inhabited by microbial organisms. There is an increasing appreciation that these resident microbes influence the fitness of their plant and animal hosts, ultimately forming a metaorganism consisting of a uni- or multicellular host and a community of associated microorganisms. Research on host–microbe interactions has become an emerging cross-disciplinary field. In both vertebrates and invertebrates a complex microbiome confers immunological, metabolic and behavioural benefits; conversely, its disturbance can contribute to the development of disease states. However, the molecular and cellular mechanisms controlling the interactions within a metaorganism are poorly understood and many key interactions between the associated organisms remain unknown. In this perspective article, we outline some of the issues in interspecies interactions and in particular address the question of how metaorganisms react and adapt to inputs from extreme environments such as deserts, the intertidal zone, oligothrophic seas, and hydrothermal vents.

Genomic insights into microbial iron oxidation and iron uptake strategies in extremely acidic environments.

Science.gov (United States)

Bonnefoy, Violaine; Holmes, David S

2012-07-01

This minireview presents recent advances in our understanding of iron oxidation and homeostasis in acidophilic Bacteria and Archaea. These processes influence the flux of metals and nutrients in pristine and man-made acidic environments such as acid mine drainage and industrial bioleaching operations. Acidophiles are also being studied to understand life in extreme conditions and their role in the generation of biomarkers used in the search for evidence of existing or past extra-terrestrial life. Iron oxidation in acidophiles is best understood in the model organism Acidithiobacillus ferrooxidans. However, recent functional genomic analysis of acidophiles is leading to a deeper appreciation of the diversity of acidophilic iron-oxidizing pathways. Although it is too early to paint a detailed picture of the role played by lateral gene transfer in the evolution of iron oxidation, emerging evidence tends to support the view that iron oxidation arose independently more than once in evolution. Acidic environments are generally rich in soluble iron and extreme acidophiles (e.g. the Leptospirillum genus) have considerably fewer iron uptake systems compared with neutrophiles. However, some acidophiles have been shown to grow as high as pH 6 and, in the case of the Acidithiobacillus genus, to have multiple iron uptake systems. This could be an adaption allowing them to respond to different iron concentrations via the use of a multiplicity of different siderophores. Both Leptospirillum spp. and Acidithiobacillus spp. are predicted to synthesize the acid stable citrate siderophore for Fe(III) uptake. In addition, both groups have predicted receptors for siderophores produced by other microorganisms, suggesting that competition for iron occurs influencing the ecophysiology of acidic environments. Little is known about the genetic regulation of iron oxidation and iron uptake in acidophiles, especially how the use of iron as an energy source is balanced with its need to take up

Standard Test Method for Measuring Extreme Heat-Transfer Rates from High-Energy Environments Using a Transient, Null-Point Calorimeter

CERN Document Server

American Society for Testing and Materials. Philadelphia

2008-01-01

1.1 This test method covers the measurement of the heat-transfer rate or the heat flux to the surface of a solid body (test sample) using the measured transient temperature rise of a thermocouple located at the null point of a calorimeter that is installed in the body and is configured to simulate a semi-infinite solid. By definition the null point is a unique position on the axial centerline of a disturbed body which experiences the same transient temperature history as that on the surface of a solid body in the absence of the physical disturbance (hole) for the same heat-flux input. 1.2 Null-point calorimeters have been used to measure high convective or radiant heat-transfer rates to bodies immersed in both flowing and static environments of air, nitrogen, carbon dioxide, helium, hydrogen, and mixtures of these and other gases. Flow velocities have ranged from zero (static) through subsonic to hypersonic, total flow enthalpies from 1.16 to greater than 4.65 × 101 MJ/kg (5 × 102 to greater than 2 × 104 ...

An Overview of SBIR Phase 2 Materials Structures for Extreme Environments

Science.gov (United States)

Nguyen, Hung D.; Steele, Gynelle C.

2015-01-01

Technological innovation is the overall focus of NASA's Small Business Innovation Research (SBIR) program. The program invests in the development of innovative concepts and technologies to help NASA's mission directorates address critical research and development needs for agency projects. This report highlights innovative SBIR Phase II projects from 2007-2012 specifically addressing Areas in Materials and Structures for Extreme Environments which is one of six core competencies at NASA Glenn Research Center. There are twenty three technologies featured with emphasis on a wide spectrum of applications such as fine-filament superconductor wire, composite oxide cathode materials, nano-composites, high radiation solar cell, wrapped multilayer insulation, thin aerogel, and much more. Each article in this booklet describes an innovation, technical objective, and highlights NASA commercial and industrial applications. This report serves as an opportunity for NASA personnel including engineers, researchers, and program managers to learn of NASA SBIR's capabilities that might be crosscutting into this technology area. As the result, it would cause collaborations and partnerships between the small companies and NASA Programs and Projects resulting in benefit to both SBIR companies and NASA.

Insertion sequences enrichment in extreme Red sea brine pool vent

KAUST Repository

Elbehery, Ali H. A.

2016-12-03

Mobile genetic elements are major agents of genome diversification and evolution. Limited studies addressed their characteristics, including abundance, and role in extreme habitats. One of the rare natural habitats exposed to multiple-extreme conditions, including high temperature, salinity and concentration of heavy metals, are the Red Sea brine pools. We assessed the abundance and distribution of different mobile genetic elements in four Red Sea brine pools including the world’s largest known multiple-extreme deep-sea environment, the Red Sea Atlantis II Deep. We report a gradient in the abundance of mobile genetic elements, dramatically increasing in the harshest environment of the pool. Additionally, we identified a strong association between the abundance of insertion sequences and extreme conditions, being highest in the harshest and deepest layer of the Red Sea Atlantis II Deep. Our comparative analyses of mobile genetic elements in secluded, extreme and relatively non-extreme environments, suggest that insertion sequences predominantly contribute to polyextremophiles genome plasticity.

Is southwestern China experiencing more frequent precipitation extremes?

International Nuclear Information System (INIS)

Liu, Meixian; Xu, Xianli; Wang, Kelin; Sun, Alexander Y; Liu, Wen; Zhang, Xiaoyan

2014-01-01

Climate extremes have and will continue to cause severe damages to buildings and natural environments around the world. A full knowledge of the probability of the climate extremes is important for the management and mitigation of natural hazards. Based on Mann–Kendall trend test and copulas, this study investigated the characteristics of precipitation extremes as well as their implications in southwestern China (Yunnan, Guangxi and Guizhou Province), through analyzing the changing trends and probabilistic characteristics of six indices, including the consecutive dry days, consecutive wet days, annual total wet day precipitation, heavy precipitation days (R25), max 5 day precipitation amount (Rx5) and the rainy days (RDs). Results showed that the study area had generally become drier (regional mean annual precipitation decreased by 11.4 mm per decade) and experienced enhanced precipitation extremes in the past 60 years. Relatively higher risk of drought in Yuanan and flood in Guangxi was observed, respectively. However, the changing trends of the precipitation extremes were not spatially uniform: increasing risk of extreme wet events for Guangxi and Guizhou, and increasing probability of concurrent extreme wet and dry events for Yunnan. Meanwhile, trend analyses of the 10 year return levels of the selected indices implied that the severity of droughts decreased in Yunnan but increased significantly in Guangxi and Guizhou, and the severity of floods increased in Yunnan and Guangxi in the past decades. Hence, the policy-makers need to be aware of the different characterizations and the spatial heterogeneity of the precipitation extremes. (letters)

Design, conception, and metrology of Extreme Ultraviolet multilayers mirrors resistant environments of space and EUV sources

International Nuclear Information System (INIS)

Hecquet, Ch.

2009-03-01

The Extreme Ultraviolet Spectrum (EUV) wavelengths, which range between 13 nm and 40 nm, have many applications in science and technology. These have been developed for example in plasma physics (high order harmonics sources, X ray lasers). The work presented is about the design, the fabrication and the metrology of periodic multilayer mirrors. The main motivation of this study is to establish a cycle of development taking into account both the optical properties of reflective coatings (reflectivity, spectral selectivity, attenuation) and their behaviour under various environments. To improve the spectral selectivity, new multilayer periodic structures have been developed. They are characterized by a bimodal reflectance profile with adjustable attenuation. The effect of environment on the stability of performance is especially critical for the optical collection. The addition of material barriers has stabilized the performance of the peak reflectivity for over 200 h at 400 C deg. and it reduces the influence of other factors of instability on the reflectance. In addition, all structures have been fabricated successfully and evaluated in severe environments. (author)

Liquid salt environment stress-rupture testing

Science.gov (United States)

Ren, Weiju; Holcomb, David E.; Muralidharan, Govindarajan; Wilson, Dane F.

2016-03-22

Disclosed herein are systems, devices and methods for stress-rupture testing selected materials within a high-temperature liquid salt environment. Exemplary testing systems include a load train for holding a test specimen within a heated inert gas vessel. A thermal break included in the load train can thermally insulate a load cell positioned along the load train within the inert gas vessel. The test specimen can include a cylindrical gage portion having an internal void filled with a molten salt during stress-rupture testing. The gage portion can have an inner surface area to volume ratio of greater than 20 to maximize the corrosive effect of the molten salt on the specimen material during testing. Also disclosed are methods of making a salt ingot for placement within the test specimen.

Conservatism implications of shock test tailoring for multiple design environments

Science.gov (United States)

Baca, Thomas J.; Bell, R. Glenn; Robbins, Susan A.

1987-01-01

A method for analyzing shock conservation in test specifications that have been tailored to qualify a structure for multiple design environments is discussed. Shock test conservation is qualified for shock response spectra, shock intensity spectra and ranked peak acceleration data in terms of an Index of Conservation (IOC) and an Overtest Factor (OTF). The multi-environment conservation analysis addresses the issue of both absolute and average conservation. The method is demonstrated in a case where four laboratory tests have been specified to qualify a component which must survive seven different field environments. Final judgment of the tailored test specification is shown to require an understanding of the predominant failure modes of the test item.

Unit Testing Using Design by Contract and Equivalence Partitions, Extreme Programming and Agile Processes in Software Engineering

DEFF Research Database (Denmark)

Madsen, Per

2003-01-01

Extreme Programming [1] and in particular the idea of Unit Testing can improve the quality of the testing process. But still programmers need to do a lot of tiresome manual work writing test cases. If the programmers could get some automatic tool support enforcing the quality of test cases then t...... then the overall quality of the software would improve significantly....

Radiation diagnostics in extremely harsh environments

International Nuclear Information System (INIS)

Dona, H.; Lee, P.H.Y.; Williams, A.H.; McGurn, J.L.; Veeser, L.R.

1986-01-01

Some recent Trailmaster experiments have required to use of rather delicate radiation diagnostics in hostile environments. We have developed instrumentation for use high-explosive magnetic flux compression generators and near the noisy environment of high energy capacitor banks. These include some rather unique ''fly-away'' designs for x-ray imaging and spectroscopy, and other optical techniques for plasma temperature and field measurements. We will show some representative data and will also discuss an on-going program for the determination of magnetic field via atomic spectral line splitting and/or broadening

Extreme Environment Electronics based on Silicon Carbide, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Radiation tolerant, extreme temperature capable electronics are needed for a variety of planned NASA missions. For example, in-situ exploration of Venus and long...

Extreme Environment Electronics based on Silicon Carbide, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Radiation tolerant, extreme temperature capable electronics are needed for a variety of planned NASA missions. For example, in-situ exploration of Venus and long...

New insights into microbial adaptation to extreme saline environments

Directory of Open Access Journals (Sweden)

Vauclare P.

2014-02-01

Full Text Available Extreme halophiles are microorganisms adapted to low water activity living at the upper salt concentration that life can tolerate. We review here recent data that specify the main factors, which determine their peculiar salt-dependent biochemistry. The data suggested that evolution proceeds by stage to modify the molecular dynamics properties of the entire proteome. Extreme halophiles therefore represent tractable models to understand how fast and to what extent microorganisms adapt to environmental changes. Halophiles are also robust organisms, capable to resist multiple stressors. Preliminary studies indicated that they have developed a cellular response specifically aimed to survive when the salt condition fluctuates. Because of these properties halophilic organisms deserve special attention in the search for traces of life on other planets.

Reliability and validity of a low load endurance strength test for upper and lower extremities in patients with fibromyalgia.

Science.gov (United States)

Munguía-Izquierdo, Diego; Legaz-Arrese, Alejandro

2012-11-01

To evaluate the reliability, standard error of the mean (SEM), clinical significant change, and known group validity of 2 assessments of endurance strength to low loads in patients with fibromyalgia syndrome (FS). Cross-sectional reliability and comparative study. University Pablo de Olavide, Seville, Spain. Middle-aged women with FS (n=95) and healthy women (n=64) matched for age, weight, and body mass index (BMI) were recruited for the study. Not applicable. The endurance strength to low loads tests of the upper and lower extremities and anthropometric measures (BMI) were used for the evaluations. The differences between the readings (tests 1 and 2) and the SDs of the differences, intraclass correlation coefficient (ICC) model (2,1), 95% confidence interval for the ICC, coefficient of repeatability, intrapatient SD, SEM, Wilcoxon signed-rank test, and Bland-Altman plots were used to examine reliability. A Mann-Whitney U test was used to analyze the differences in test values between the patient group and the control group. We hypothesized that patients with FS would have an endurance strength to low loads performance in lower and upper extremities at least twice as low as that of the healthy controls. Satisfactory test-retest reliability and SEMs were found for the lower extremity, dominant arm, and nondominant arm tests (ICC=.973-.979; P.05 for all). The Bland-Altman plots showed 95% limits of agreement for the lower extremity (4.7 to -4.5), dominant arm (3.8 to -4.4), and nondominant arm (3.9 to -4.1) tests. The endurance strength to low loads test scores for the patients with FS were 4-fold lower than for the controls in all performed tests (P<.001 for all). The endurance strength to low loads tests showed good reliability and known group validity and can be recommended for evaluating endurance strength to low loads in patients with FS. For individual evaluation, however, an improved score of at least 4 and 5 repetitions for the upper and lower extremities

Has the "Equal Environments" assumption been tested in twin studies?

Science.gov (United States)

Eaves, Lindon; Foley, Debra; Silberg, Judy

2003-12-01

A recurring criticism of the twin method for quantifying genetic and environmental components of human differences is the necessity of the so-called "equal environments assumption" (EEA) (i.e., that monozygotic and dizygotic twins experience equally correlated environments). It has been proposed to test the EEA by stratifying twin correlations by indices of the amount of shared environment. However, relevant environments may also be influenced by genetic differences. We present a model for the role of genetic factors in niche selection by twins that may account for variation in indices of the shared twin environment (e.g., contact between members of twin pairs). Simulations reveal that stratification of twin correlations by amount of contact can yield spurious evidence of large shared environmental effects in some strata and even give false indications of genotype x environment interaction. The stratification approach to testing the equal environments assumption may be misleading and the results of such tests may actually be consistent with a simpler theory of the role of genetic factors in niche selection.

Towards a Development Environment for Model Based Test Design

OpenAIRE

Jing, Han

2008-01-01

Within the UP IP I&V organization there is high focus on increasing the ability to predict product quality in a cost efficient way. Test automation has therefore been an important enabler for us. The IP test design environment is continuously evolving and the investigations will show which improvements that is most important to implement in short and long term. In Ericsson UP IP I&V, the test automation framework environments are severed to complete some process by automated method, f...

Optical diagnostics in the advanced test accelerator (ATA) environment

International Nuclear Information System (INIS)

Chong, Y.P.; Cornish, J.P.; Donnelly, D.

1987-05-01

The ATA is a 50-MeV, 10-kA, 70-ns pulsed electron beam accelerator that generates an extremely harsh environment for diagnostic measurements. Diagnostic targets placed in the beamline are subject to damage, frequently being destroyed by a single pulse. High radiation (x-ray, gamma, and neutron) and electromagnetic interference levels preclude placing components near the beamline that are susceptible to radiation damage. Examples of such components are integrated circuit elements, hydrocarbons such as Teflon insulation, and optical components that darken, resulting in transmission loss. Optical diagnostics play an important part in measuring experimental parameters such as the beam current density profile. A large number of optical lines of sight (LOS) are routinely deployed along the experimental beamlines that use the ATA beam. Gated TV cameras are located outside the accelerator tunnel, because the tunnel is inaccessible during operations. We will describe and discuss the difficulties, problems, and solutions encountered in making optical measurements in the ATA environment

The U.S. Department of Energy Laboratory Accreditation Program for testing the performance of extremity dosimetry systems: a summary of the program status

International Nuclear Information System (INIS)

Cummings, F.M.; Carlson, R.D.; Gesell, T.F.; Loesch, R.M.

1992-01-01

In 1986, The U.S. Department of Energy (DOE) implemented a program to test the performance of its personnel whole-body dosimetry systems. This program was the DOE Laboratory Accreditation Program (DOELAP). The program parallels the performance testing program specified in the American National Standard for Dosimetry - Personnel Dosimetry Performance -Criteria for Testing (ANSI N13.11-1983), but also addresses the additional dosimetry needs of DOE facilities. As an extension of the whole-body performance testing program, the DOE is now developing a program to test the performance of personnel extremity dosimetry systems. The draft DOE standard for testing extremity dosimetry systems is much less complex than the whole-body dosimetry standard and reflects the limitations imposed on extremity dosimetry by dosimeter design and irradiation geometry. A pilot performance test session has been conducted to evaluate the proposed performance-testing standard. (author)

Gene adaptation to extreme environments

International Nuclear Information System (INIS)

Marlaire, P.; Rodriguez, V.; Kerner, N.

2005-01-01

Full text: This work is oriented to the study of gene adaptation to extreme conditions, such as the hydrothermal system located in Copahue, Neuquen, Argentina. The organisms living there develop under two pressure selection conditions: the high temperature of thermal water and the strong impact of ultraviolet (UV) radiation. Several microorganisms found in this region were isolated and different colonies resistant to UV radiation were selected, a Geobacillus thermoleovorans strain identified through 16S RNA sequence, being the most remarkable. A gene library was prepared out of this strain with UV sensitive bacteria BH200 (uvrA::Tn10). A number of clones were isolated by means of UV selection, the most outstanding being a gene carrier able to codify for the guanosine monophosphate synthetase enzyme (GMPs). The suitability of said enzyme was proved by means of additional assays performed on ght 1 bacteria (guaA26::Tn 10) which lacked the enzyme. A transcript of 1100 pb was detected through Northern Blot. The result was consistent with that obtained for the mapping of the starting transcription site. The cloned GMPs produces an increase in growth speed and a greater biomass in BH200 bacteria. (author)

Simulating extreme environments: Ergonomic evaluation of Chinese pilot performance and heat stress tolerance.

Science.gov (United States)

Li, Jing; Tian, Yinsheng; Ding, Li; Zou, Huijuan; Ren, Zhaosheng; Shi, Liyong; Feathers, David; Wang, Ning

2015-06-05

High-temperatures in the cockpit environment can adversely influence pilot behavior and performance. To investigate the impact of high thermal environments on Chinese pilot performance in a simulated cockpit environment. Ten subjects volunteered to participate in the tests under 40°C and 45°C high-temperature simulations in an environmentally controlled chamber. Measures such as grip strength, perception, dexterity, somatic sense reaction, and analytical reasoning were taken. The results were compared to the Combined Index of Heat Stress (CIHS). CIHS exceeded the heat stress safety limit after 45 min under 40°C, grip strength decreased by 12% and somatic perception became 2.89 times larger than the initial value. In the case of 45°C, CIHS exceeded the safety limit after only 20 min, while the grip strength decreased just by 3.2% and somatic perception increased to 4.36 times larger than the initial value. Reaction and finger dexterity were not statistically different from baseline measurements, but the error rate of analytical reasoning test rose remarkably. Somatic perception was the most sensitive index to high-temperature, followed by grip strength. Results of this paper may help to improve environmental control design of new fighter cockpit and for pilot physiology and cockpit environment ergonomics research for Chinese pilots.

Robust Tests for Additive Gene-Environment Interaction in Case-Control Studies Using Gene-Environment Independence

DEFF Research Database (Denmark)

Liu, Gang; Lee, Seunggeun; Lee, Alice W

2018-01-01

test with case-control data. Our simulation studies suggest that the EB approach uses the gene-environment independence assumption in a data-adaptive way and provides power gain compared to the standard logistic regression analysis and better control of Type I error when compared to the analysis......There have been recent proposals advocating the use of additive gene-environment interaction instead of the widely used multiplicative scale, as a more relevant public health measure. Using gene-environment independence enhances the power for testing multiplicative interaction in case......-control studies. However, under departure from this assumption, substantial bias in the estimates and inflated Type I error in the corresponding tests can occur. This paper extends the empirical Bayes (EB) approach previously developed for multiplicative interaction that trades off between bias and efficiency...

Digital Learning Network Education Events of NASA's Extreme Environments Mission Operations

Science.gov (United States)

Paul, Heather; Guillory, Erika

2007-01-01

NASA's Digital Learning Network (DLN) reaches out to thousands of students each year through video conferencing and web casting. The DLN has created a series of live education videoconferences connecting NASA s Extreme Environment Missions Operations (NEEMO) team to students across the United States. The programs are also extended to students around the world live web casting. The primary focus of the events is the vision for space exploration. During the programs, NEEMO Crewmembers including NASA astronauts, engineers and scientists inform and inspire students about the importance of exploration and share the impact of the project as it correlates with plans to return to the moon and explore the planet Mars. These events highlight interactivity. Students talk live with the aquanauts in Aquarius, the National Oceanic and Atmospheric Administration s underwater laboratory. With this program, NASA continues the Agency s tradition of investing in the nation's education programs. It is directly tied to the Agency's major education goal of attracting and retaining students in science, technology, and engineering disciplines. Before connecting with the aquanauts, the students conduct experiments of their own designed to coincide with mission objectives. This paper describes the events that took place in September 2006.

Massive stars dying alone: Extremely remote environments of SN2009ip and SN2010jp

Science.gov (United States)

Smith, Nathan

2014-10-01

We propose an imaging study of the astonishingly remote environments of two recent supernovae (SNe): SN2009ip and SN2010jp. Both were unusual Type IIn explosions that crashed into dense circumstellar material (CSM) ejected by the star shortly before explosion. The favored progenitors of these SNe are very massive luminous blue variable (LBV) stars. In fact, SN2009ip presents an extraordinay case where the LBV-like progenitor was actually detected directly in archival HST data, and where we obtained spectra and photometry for numerous pre-SN eruptions. No other SN has this treasure trove of detailed information about the progenitor (not even SN1987A). SN2010jp represents a possible collapsar-powered event, since it showed evidence of a fast bipolar jet in spectra and a low 56Ni mass; this would be an analog of the black-hole forming explosions that cause gamma ray bursts, but where the relativistic jet is damped by a residual H envelope on the star. In both cases, the only viable models for these SNe involve extremely massive (initial masses of 40-100 Msun) progenitor stars. This seems at odds with their extremely remote environments in the far outskirts of their host galaxies, with no detected evidence for an underlying massive star population in ground-based data (nor in the single shallow WFPC2/F606W image of SN2009ip). Here we propose deep UV HST images to search for any mid/late O-type stars nearby, deep red images to detect any red supergiants, and an H-alpha image to search for any evidence of ongoing star formation in the vicinity. These observations will place important and demanding constraints on the initial masses and ages of these progenitors.

An extreme magneto-ionic environment associated with the fast radio burst source FRB 121102

Science.gov (United States)

Michilli, D.; Seymour, A.; Hessels, J. W. T.; Spitler, L. G.; Gajjar, V.; Archibald, A. M.; Bower, G. C.; Chatterjee, S.; Cordes, J. M.; Gourdji, K.; Heald, G. H.; Kaspi, V. M.; Law, C. J.; Sobey, C.; Adams, E. A. K.; Bassa, C. G.; Bogdanov, S.; Brinkman, C.; Demorest, P.; Fernandez, F.; Hellbourg, G.; Lazio, T. J. W.; Lynch, R. S.; Maddox, N.; Marcote, B.; McLaughlin, M. A.; Paragi, Z.; Ransom, S. M.; Scholz, P.; Siemion, A. P. V.; Tendulkar, S. P.; van Rooy, P.; Wharton, R. S.; Whitlow, D.

2018-01-01

Fast radio bursts are millisecond-duration, extragalactic radio flashes of unknown physical origin. The only known repeating fast radio burst source—FRB 121102—has been localized to a star-forming region in a dwarf galaxy at redshift 0.193 and is spatially coincident with a compact, persistent radio source. The origin of the bursts, the nature of the persistent source and the properties of the local environment are still unclear. Here we report observations of FRB 121102 that show almost 100 per cent linearly polarized emission at a very high and variable Faraday rotation measure in the source frame (varying from +1.46 × 105 radians per square metre to +1.33 × 105 radians per square metre at epochs separated by seven months) and narrow (below 30 microseconds) temporal structure. The large and variable rotation measure demonstrates that FRB 121102 is in an extreme and dynamic magneto-ionic environment, and the short durations of the bursts suggest a neutron star origin. Such large rotation measures have hitherto been observed only in the vicinities of massive black holes (larger than about 10,000 solar masses). Indeed, the properties of the persistent radio source are compatible with those of a low-luminosity, accreting massive black hole. The bursts may therefore come from a neutron star in such an environment or could be explained by other models, such as a highly magnetized wind nebula or supernova remnant surrounding a young neutron star.

Genomic selection improves response to selection in resilience by exploiting genotype by environment interactions

Directory of Open Access Journals (Sweden)

Han Mulder

2016-10-01

Full Text Available Genotype by environment interactions (GxE are very common in livestock and hamper genetic improvement. On the other hand, GxE is a source of genetic variation: genetic variation in response to environment, e.g. environmental perturbations such as heat stress or disease. In livestock breeding, there is tendency to ignore GxE because of increased complexity of models for genetic evaluations and lack of accuracy in extreme environments. GxE, however, creates opportunities to increase resilience of animals towards environmental perturbations. The main aim of the paper is to investigate to which extent GxE can be exploited with traditional and genomic selection methods. Furthermore, we investigated the benefit of reaction norm models compared to conventional methods ignoring GxE. The questions were addressed with selection index theory. GxE was modelled according to a linear reaction norm model in which the environmental gradient is the contemporary group mean. Economic values were based on linear and non-linear profit equations.Accuracies of environment-specific (GEBV were highest in intermediate environments and lowest in extreme environments. Reaction norm models had higher accuracies of (GEBV in extreme environments than conventional models ignoring GxE. Genomic selection always resulted in higher response to selection in all environments than sib or progeny testing schemes. The increase in response was with genomic selection between 9% and 140% compared to sib testing and between 11% and 114% compared to progeny testing when the reference population consisted of 1 million animals across all environments. When the aim was to decrease environmental sensitivity, the response in slope of the reaction norm model with genomic selection was between 1.09 and 319 times larger than with sib or progeny testing and in the right direction in contrast to sib and progeny testing that still increased environmental sensitivity. This shows that genomic selection

Functional studies in 79-year-olds. II. Upper extremity function.

Science.gov (United States)

Lundgren-Lindquist, B; Sperling, L

1983-01-01

As part of the Gerontological and Geriatric Population Study of 79-year-old people in Göteborg, a representative subsample comprising 112 women and 93 men took part in a study of upper extremity function. Thirty-eight per cent of the women and 37% of the men had disorders in the upper extremities. The investigation included tests of co-ordination, static strength in the key-grip and the transversal volar grip, power capacity in opening jars and a bottle, basal movements in the upper extremities in personal hygiene and dressing activities, function in the kitchen e.g. reaching shelves, manual tasks including tests of pronation and supination of the forearm. In the key-grip as well as in the transversal volar grip men showed a generally larger decrease in strength with age than women compared to 70-year-olds in a previous population study. Significant correlations were found between strength in the key-grip and the performance time in the test of co-ordination. Women produced about 66% of the muscular force of the men when opening jars. Significant correlations were found between strength in the transversal volar grip and the maximal torque for opening the jars. Female and male subjects who were not capable of handling the electric plug in the manual ability test had significantly weaker strength in the key-grip. The importance of designing products and adapting the environment so as to correspond to the functional capacity of the elderly, is emphasized.

Global patterns of NDVI-indicated vegetation extremes and their sensitivity to climate extremes

International Nuclear Information System (INIS)

Liu Guo; Liu Hongyan; Yin Yi

2013-01-01

Extremes in climate have significant impacts on ecosystems and are expected to increase under future climate change. Extremes in vegetation could capture such impacts and indicate the vulnerability of ecosystems, but currently have not received a global long-term assessment. In this study, a robust method has been developed to detect significant extremes (low values) in biweekly time series of global normalized difference vegetation index (NDVI) from 1982 to 2006 and thus to acquire a global pattern of vegetation extreme frequency. This pattern coincides with vegetation vulnerability patterns suggested by earlier studies using different methods over different time spans, indicating a consistent mechanism of regulation. Vegetation extremes were found to aggregate in Amazonia and in the semi-arid and semi-humid regions in low and middle latitudes, while they seldom occurred in high latitudes. Among the environmental variables studied, extreme low precipitation has the highest slope against extreme vegetation. For the eight biomes analyzed, these slopes are highest in temperate broadleaf forest and temperate grassland, suggesting a higher sensitivity in these environments. The results presented here contradict the hypothesis that vegetation in water-limited semi-arid and semi-humid regions might be adapted to drought and suggest that vegetation in these regions (especially temperate broadleaf forest and temperate grassland) is highly prone to vegetation extreme events under more severe precipitation extremes. It is also suggested here that more attention be paid to precipitation-induced vegetation changes than to temperature-induced events. (letter)

Implementation of a control system test environment in UNIX

International Nuclear Information System (INIS)

Brittain, C.R.; Otaduy, P.J.; Rovere, L.A.

1990-01-01

This paper discusses how UNIX features such as shared memory, remote procedure calls, and signalling have been used to implement a distributed computational environment ideal for the development and testing of digital control systems. The resulting environment -based on features commonly available in commercial workstations- is flexible, allows process simulation and controller development to proceed in parallel, and provides for testing and validation in a realistic environment. In addition, the use of shared memory to exchange data allows other tasks such as user interfaces and recorders to be added without affecting the process simulation or controllers. A library of functions is presented which provides a simple interface to using the features described. These functions can be used in either C or FORTRAN programs and have been tested on a network of Sun workstations and an ENCORE parallel computer. 6 refs., 2 figs

Thermosyphon Flooding in Reduced Gravity Environments Test Results

Science.gov (United States)

Gibson, Marc A.; Jaworske, Donald A.; Sanzi, Jim; Ljubanovic, Damir

2013-01-01

The condenser flooding phenomenon associated with gravity aided two-phase thermosyphons was studied using parabolic flights to obtain the desired reduced gravity environment (RGE). The experiment was designed and built to test a total of twelve titanium water thermosyphons in multiple gravity environments with the goal of developing a model that would accurately explain the correlation between gravitational forces and the maximum axial heat transfer limit associated with condenser flooding. Results from laboratory testing and parabolic flights are included in this report as part I of a two part series. The data analysis and correlations are included in a follow on paper.

Imaging of neuro-cognitive performance in extreme Environments—A (p)review

Science.gov (United States)

Schneider, Stefan; Bubeev, Juri A.; Choukèr, Alexander; Morukov, Boris; Johannes, Bernd; Strüder, Heiko K.

2012-12-01

Living in extreme environments is accompanied by a number of stressors, which can be classified either as physiological stressors (e.g. microgravity, missing sunlight) or psychological stressors (e.g. confinement). From earth bound studies a negative impact of stress on mental health and cognitive performance is well known and both factors might impair mission success and mission safety during longer inhabitation of space. Accordingly there is the need to identify adequate countermeasures. Nevertheless causal research of neuro-cognitive impairments in space remains speculative due to missing possibilities of brain imaging. Furthermore the reliability of current psychological tests used to assess and monitor cognitive performance in extreme environments seems to be vulnerable due to a lack of compliance. With on-going plans of international space agencies to send people to moon and/or mars, this manuscript aims to summarize and review research attempts of the past two decades and to identify methodological shortcomings. Finally, following the guideline that research has no legacy for its own but must serve the self-concept and well-being of man, this manuscript presents a number of recommendations to enhance future neuro-cognitive research in extreme environments. A deeper insight into neuro-cognitive coherence is not only desirable to understand the effects of stress on mental health, which seems to be a major issue for our current society, and to develop adequate countermeasures but will also help to maintain and improve mission success and mission safety in manned space flight.

Design and performance of capping layers for extreme-ultraviolet multilayer mirrors

International Nuclear Information System (INIS)

Bajt, Sasa; Chapman, Henry N.; Nguyen, Nhan; Alameda, Jennifer; Robinson, Jeffrey C.; Malinowski, Michael; Gullikson, Eric; Aquila, Andrew; Tarrio, Charles; Grantham, Steven

2003-01-01

Multilayer lifetime has emerged as one of the major issues for the commercialization of extreme-ultraviolet lithography (EUVL). We describe the performance of an oxidation-resistant capping layer of Ru atop multilayers that results in a reflectivity above 69% at 13.2 nm, which is suitable for EUVL projection optics and has been tested with accelerated electron-beam and extreme-ultraviolet (EUV) light in a water-vapor environment. Based on accelerated exposure results, we calculated multilayer lifetimes for all reflective mirrors in a typical commercial EUVL tool and concluded that Ru-capped multilayers have ∼40x longer lifetimes than Si-capped multilayers, which translates to 3 months to many years, depending on the mirror dose

Prediction of software operational reliability using testing environment factors

International Nuclear Information System (INIS)

Jung, Hoan Sung; Seong, Poong Hyun

1995-01-01

A number of software reliability models have been developed to estimate and to predict software reliability. However, there are no established standard models to quantify software reliability. Most models estimate the quality of software in reliability figures such as remaining faults, failure rate, or mean time to next failure at the testing phase, and they consider them ultimate indicators of software reliability. Experience shows that there is a large gap between predicted reliability during development and reliability measured during operation, which means that predicted reliability, or so-called test reliability, is not operational reliability. Customers prefer operational reliability to test reliability. In this study, we propose a method that predicts operational reliability rather than test reliability by introducing the testing environment factor that quantifies the changes in environments

Adaptation strategies of endolithic chlorophototrophs to survive the hyperarid and extreme solar radiation environment of the Atacama Desert.

Science.gov (United States)

Wierzchos, Jacek; DiRuggiero, Jocelyne; Vítek, Petr; Artieda, Octavio; Souza-Egipsy, Virginia; Škaloud, Pavel; Tisza, Michel; Davila, Alfonso F; Vílchez, Carlos; Garbayo, Inés; Ascaso, Carmen

2015-01-01

The Atacama Desert, northern Chile, is one of the driest deserts on Earth and, as such, a natural laboratory to explore the limits of life and the strategies evolved by microorganisms to adapt to extreme environments. Here we report the exceptional adaptation strategies of chlorophototrophic and eukaryotic algae, and chlorophototrophic and prokaryotic cyanobacteria to the hyperarid and extremely high solar radiation conditions occurring in this desert. Our approach combined several microscopy techniques, spectroscopic analytical methods, and molecular analyses. We found that the major adaptation strategy was to avoid the extreme environmental conditions by colonizing cryptoendolithic, as well as, hypoendolithic habitats within gypsum deposits. The cryptoendolithic colonization occurred a few millimeters beneath the gypsum surface and showed a succession of organized horizons of algae and cyanobacteria, which has never been reported for endolithic microbial communities. The presence of cyanobacteria beneath the algal layer, in close contact with sepiolite inclusions, and their hypoendolithic colonization suggest that occasional liquid water might persist within these sub-microhabitats. We also identified the presence of abundant carotenoids in the upper cryptoendolithic algal habitat and scytonemin in the cyanobacteria hypoendolithic habitat. This study illustrates that successful lithobiontic microbial colonization at the limit for microbial life is the result of a combination of adaptive strategies to avoid excess solar irradiance and extreme evapotranspiration rates, taking advantage of the complex structural and mineralogical characteristics of gypsum deposits-conceptually called "rock's habitable architecture." Additionally, self-protection by synthesis and accumulation of secondary metabolites likely produces a shielding effect that prevents photoinhibition and lethal photooxidative damage to the chlorophototrophs, representing another level of adaptation.

Test and analysis of indoor environment of dormitories of universities in autumn

Science.gov (United States)

Chen, Shijia

2017-03-01

In this paper, the indoor thermal and humid environment, luminous environment and acoustic environment of college dormitories in Baoding are tested and conducted a questionnaire survey. From the test, the subjective feelings and the objective evaluation parameters of the students in the dormitory were obtained. At last, the differences of thermal comfort, luminous environment and acoustic environment caused by students' different living habits and adaptability were analyzed.

Independent test assessment using the extreme value distribution theory.

Science.gov (United States)

Almeida, Marcio; Blondell, Lucy; Peralta, Juan M; Kent, Jack W; Jun, Goo; Teslovich, Tanya M; Fuchsberger, Christian; Wood, Andrew R; Manning, Alisa K; Frayling, Timothy M; Cingolani, Pablo E; Sladek, Robert; Dyer, Thomas D; Abecasis, Goncalo; Duggirala, Ravindranath; Blangero, John

2016-01-01

The new generation of whole genome sequencing platforms offers great possibilities and challenges for dissecting the genetic basis of complex traits. With a very high number of sequence variants, a naïve multiple hypothesis threshold correction hinders the identification of reliable associations by the overreduction of statistical power. In this report, we examine 2 alternative approaches to improve the statistical power of a whole genome association study to detect reliable genetic associations. The approaches were tested using the Genetic Analysis Workshop 19 (GAW19) whole genome sequencing data. The first tested method estimates the real number of effective independent tests actually being performed in whole genome association project by the use of an extreme value distribution and a set of phenotype simulations. Given the familiar nature of the GAW19 data and the finite number of pedigree founders in the sample, the number of correlations between genotypes is greater than in a set of unrelated samples. Using our procedure, we estimate that the effective number represents only 15 % of the total number of independent tests performed. However, even using this corrected significance threshold, no genome-wide significant association could be detected for systolic and diastolic blood pressure traits. The second approach implements a biological relevance-driven hypothesis tested by exploiting prior computational predictions on the effect of nonsynonymous genetic variants detected in a whole genome sequencing association study. This guided testing approach was able to identify 2 promising single-nucleotide polymorphisms (SNPs), 1 for each trait, targeting biologically relevant genes that could help shed light on the genesis of the human hypertension. The first gene, PFH14 , associated with systolic blood pressure, interacts directly with genes involved in calcium-channel formation and the second gene, MAP4 , encodes a microtubule-associated protein and had already

Trends analysis of rainfall and rainfall extremes in Sarawak, Malaysia using modified Mann-Kendall test

Science.gov (United States)

Sa'adi, Zulfaqar; Shahid, Shamsuddin; Ismail, Tarmizi; Chung, Eun-Sung; Wang, Xiao-Jun

2017-11-01

This study assesses the spatial pattern of changes in rainfall extremes of Sarawak in recent years (1980-2014). The Mann-Kendall (MK) test along with modified Mann-Kendall (m-MK) test, which can discriminate multi-scale variability of unidirectional trend, was used to analyze the changes at 31 stations. Taking account of the scaling effect through eliminating the effect of autocorrelation, m-MK was employed to discriminate multi-scale variability of the unidirectional trends of the annual rainfall in Sarawak. It can confirm the significance of the MK test. The annual rainfall trend from MK test showed significant changes at 95% confidence level at five stations. The seasonal trends from MK test indicate an increasing rate of rainfall during the Northeast monsoon and a decreasing trend during the Southwest monsoon in some region of Sarawak. However, the m-MK test detected an increasing trend in annual rainfall only at one station and no significant trend in seasonal rainfall at any stations. The significant increasing trends of the 1-h maximum rainfall from the MK test are detected mainly at the stations located in the urban area giving concern to the occurrence of the flash flood. On the other hand, the m-MK test detected no significant trend in 1- and 3-h maximum rainfalls at any location. On the contrary, it detected significant trends in 6- and 72-h maximum rainfalls at a station located in the Lower Rajang basin area which is an extensive low-lying agricultural area and prone to stagnant flood. These results indicate that the trends in rainfall and rainfall extremes reported in Malaysia and surrounding region should be verified with m-MK test as most of the trends may result from scaling effect.

Adaptation to extreme environments: structure-function relationships in Emperor penguin haemoglobin.

Science.gov (United States)

Tamburrini, M; Condò, S G; di Prisco, G; Giardina, B

1994-04-15

The functional properties of the single haemoglobin (Hb) of Emperor penguin (Aptenodytes forsteri) have been investigated at different temperatures as a function of proton and organic phosphate concentration. The complete amino acid sequence has been established. Comparison with that of human HbA shows 12 substitutions in the contact regions of alpha beta dimers. In addition to overall similarities shared with most of the avian Hbs previously described, this Hb shows significant differences, which could be related to the peculiar behaviour of this penguin. In particular we may consider that: (1) the shape of the Bohr effect curve seems well adapted for gas exchange during very prolonged dives, preserving penguin Hb from a sudden and not controlled stripping of oxygen; (2) the very minor enthalpy change observed at lower pH could be an example of molecular adaptation, through which oxygen delivery becomes essentially insensitive to exposure to the extremely low temperatures of the environment. Moreover, the small alkaline Bohr effect has been found to be only chloride-linked, since the pH dependence of the oxygen affinity is totally abolished in the absence of this ion. These functional characteristics are discussed on the basis of the primary structure of alpha and beta-chains.

Fiscal 1990 achievement report on next-generation industrial structure technology. Research and development of advanced materials for extreme environments (Research and development of advanced materials for extreme environments); 1990 nendo chotaikankyosei senshin zairyo no kenkyu kaihatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-03-01

Research and development went on for coal pitch derived and PAN (polyacrylonitrile) based carbon fiber/carbon matrix composite materials for use under high temperature environments, and a comprehensive survey was also conducted on the said materials. For the development of C/C (carbon/carbon) composite materials using coal pitch derived or PAN based carbon fibers, the carbonization process and the like were studied for improvement on carbon based matrix material performance, and basic studies were conducted for the compounding and molding of C/C composite materials under ultrahigh temperature/pressure circumstances. Oxidation resistant coatings were fabricated by use of candidate materials expected to present excellent oxidation resistance, and technical problems were isolated and studied for the optimization of the technology of surface coating. In the comprehensive survey, the latest technical trends inside and outside Japan were investigated, and technical issues were studied for the development of materials usable under extreme environments such as ultrahigh temperatures. (NEDO)

Field test of wireless sensor network in the nuclear environment

International Nuclear Information System (INIS)

Li, L.; Wang, Q.; Bari, A.; Deng, C.; Chen, D.; Jiang, J.; Alexander, Q.; Sur, B.

2014-01-01

Wireless sensor networks (WSNs) are appealing options for the health monitoring of nuclear power plants due to their low cost and flexibility. Before they can be used in highly regulated nuclear environments, their reliability in the nuclear environment and compatibility with existing devices have to be assessed. In situ electromagnetic interference tests, wireless signal propagation tests, and nuclear radiation hardness tests conducted on candidate WSN systems at AECL Chalk River Labs are presented. The results are favourable to WSN in nuclear applications. (author)

Field test of wireless sensor network in the nuclear environment

Energy Technology Data Exchange (ETDEWEB)

Li, L., E-mail: lil@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Wang, Q.; Bari, A. [Univ. of Western Ontario, London, Ontario (Canada); Deng, C.; Chen, D. [Univ. of Electronic Science and Technology of China, Chengdu, Sichuan (China); Jiang, J. [Univ. of Western Ontario, London, Ontario (Canada); Alexander, Q.; Sur, B. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

2014-06-15

Wireless sensor networks (WSNs) are appealing options for the health monitoring of nuclear power plants due to their low cost and flexibility. Before they can be used in highly regulated nuclear environments, their reliability in the nuclear environment and compatibility with existing devices have to be assessed. In situ electromagnetic interference tests, wireless signal propagation tests, and nuclear radiation hardness tests conducted on candidate WSN systems at AECL Chalk River Labs are presented. The results are favourable to WSN in nuclear applications. (author)

Overview of the Space Launch System Ascent Aeroacoustic Environment Test Program

Science.gov (United States)

Herron, Andrew J.; Crosby, William A.; Reed, Darren K.

2016-01-01

Characterization of accurate flight vehicle unsteady aerodynamics is critical for component and secondary structure vibroacoustic design. The Aerosciences Branch at the National Aeronautics and Space Administration (NASA) Marshall Space Flight Center has conducted a test at the NASA Ames Research Center (ARC) Unitary Plan Wind Tunnels (UPWT) to determine such ascent aeroacoustic environments for the Space Launch System (SLS). Surface static pressure measurements were also collected to aid in determination of local environments for venting, CFD substantiation, and calibration of the flush air data system located on the launch abort system. Additionally, this test supported a NASA Engineering and Safety Center study of alternate booster nose caps. Testing occurred during two test campaigns: August - September 2013 and December 2013 - January 2014. Four primary model configurations were tested for ascent aeroacoustic environment definition. The SLS Block 1 vehicle was represented by a 2.5% full stack model and a 4% truncated model. Preliminary Block 1B payload and manned configurations were also tested, using 2.5% full stack and 4% truncated models respectively. This test utilized the 11 x 11 foot transonic and 9 x 7 foot supersonic tunnel sections at the ARC UPWT to collect data from Mach 0.7 through 2.5 at various total angles of attack. SLS Block 1 design environments were developed primarily using these data. SLS Block 1B preliminary environments have also been prepared using these data. This paper discusses the test and analysis methodology utilized, with a focus on the unsteady data collection and processing.

Adaptation strategies of endolithic chlorophototrophs to survive the hyperarid and extreme solar radiation environment of the Atacama Desert

Directory of Open Access Journals (Sweden)

Jacek eWierzchos

2015-09-01

Full Text Available The Atacama Desert, northern Chile, is one of the driest deserts on Earth and, as such, a natural laboratory to explore the limits of life and the strategies evolved by microorganisms to adapt to extreme environments. Here we report the exceptional adaptation strategies of chlorophototrophic and eukaryotic algae, and chlorophototrophic and prokaryotic cyanobacteria to the hyperarid and extremely high solar radiation conditions occurring in this desert. Our approach combined several microscopy techniques, spectroscopic analytical methods, and molecular analyses. We found that the major adaptation strategy was to avoid the extreme environmental conditions by colonizing cryptoendolithic, as well as, hypoendolithic habitats within gypsum deposits. The cryptoendolithic colonization occurred a few millimeters beneath the gypsum surface and showed a succession of organized horizons of algae and cyanobacteria, which has never been reported for endolithic microbial communities. The presence of cyanobacteria beneath the algal layer, in close contact with sepiolite inclusions, and their hypoendolithic colonization suggest that occasional liquid water might persist within these sub-microhabitats. We also identified the presence of abundant carotenoids in the upper cryptoendolithic algal habitat and scytonemin in the cyanobacteria hypoendolithic habitat. This study illustrates that successful lithobiontic microbial colonization at the limit for microbial life is the result of a combination of adaptive strategies to avoid excess solar irradiance and extreme evapotranspiration rates, taking advantage of the complex structural and mineralogical characteristics of gypsum deposits – conceptually called rock’s habitable architecture. Additionally self-protection by synthesis and accumulation of secondary metabolites likely produces a shielding effect that prevents photoinhibition and lethal photooxidative damage to the chlorophototrophs, representing another

AEC testing in a CR environment

International Nuclear Information System (INIS)

McLeod, R.

2004-01-01

Full text: Testing of x-ray machine automatic exposure control (AEC) functionality for varying kVp and patient thickness is a fundamental health physics check. Current test protocols tend to be based on testing in a film environment using film optical density as the measure of conformance. With the move into the digital x-ray image age with the use of computed radiography (CR) and digital radiography (DR) equipment and its associated image storage and retrieval system (PACS) a new AEC testing protocol is required. All CR systems provide a dose assessment tool (called Exposure Index or EI by Kodak) that could be used as a surrogate for optical density. However this work aims to derive an efficient means of assessing the functioning of the AEC of x-ray machines in a CR environment using dose measurement alone. This would eliminate the need to process the many image plates normally required for AEC testing in order to obtain and analyse the exposure measure from the CR system. The EI, and other brand's equivalents, is calibrated for a given condition (for Kodak 80kVp 0.5mmCu + 1mmAl). In order to use dose measurement alone the relationship between EI and dose must be known for varying kVp and patient thicknesses (represented by a perspex phantom). This will depend on the response of the CR plate to varying beam energies. This was assessed using a series of paired exposures at various kVp and perspex thicknesses. In the first exposure of each pair a Kodak CR plate was used, processed in the normal way, and the EI noted. In a second identical exposure an Innovision 35050A pancake ionization chamber was placed in the bucky tray within a specially modified film cassette and the dose measured. Over the 50-125kVp range of clinical use the kV response of the Kodak PSP's shown below is essentially flat for a set dose to the image plate and filtered using the standard Kodak method of 0.5mmCu + 1mmAl. Similar data will be presented showing this relationship using a perspex

Evolution caused by extreme events.

Science.gov (United States)

Grant, Peter R; Grant, B Rosemary; Huey, Raymond B; Johnson, Marc T J; Knoll, Andrew H; Schmitt, Johanna

2017-06-19

Extreme events can be a major driver of evolutionary change over geological and contemporary timescales. Outstanding examples are evolutionary diversification following mass extinctions caused by extreme volcanism or asteroid impact. The evolution of organisms in contemporary time is typically viewed as a gradual and incremental process that results from genetic change, environmental perturbation or both. However, contemporary environments occasionally experience strong perturbations such as heat waves, floods, hurricanes, droughts and pest outbreaks. These extreme events set up strong selection pressures on organisms, and are small-scale analogues of the dramatic changes documented in the fossil record. Because extreme events are rare, almost by definition, they are difficult to study. So far most attention has been given to their ecological rather than to their evolutionary consequences. We review several case studies of contemporary evolution in response to two types of extreme environmental perturbations, episodic (pulse) or prolonged (press). Evolution is most likely to occur when extreme events alter community composition. We encourage investigators to be prepared for evolutionary change in response to rare events during long-term field studies.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'. © 2017 The Author(s).

Avoidance behaviour testing of Eisenia andrei in biodegradable plastic environment

Directory of Open Access Journals (Sweden)

Zuzana Tichá

2013-01-01

Full Text Available Avoidance behaviour test with the earthworms (ISO 17512-1:2008 is a rapid screening test for the evaluation of soil and the influence of pollutants and chemicals on the behaviour of earthworms. The purpose of the testing is to determine the avoidance behaviour of earthworm (in this case Eisenia andrei was used which can be used as an organism for the composting and occur naturally in soil environment. The methodology was modified according to the needs of the avoidance behaviour testing of earthworms in biodegradable plastic environment. It is a biodegradable thermoplastic material Mater-Bi, which is produced from corn starch. Californian earthworm (Eisenia andrei was chosen as a test organism. The two-chamber test was used in testing. 10 earthworms were used, which were exposed to a number of concentrations of the test substance, which was mixed into the compost environment. It was recorded both a positive result, avoidance reaction, as well as a negative result, non-avoidance reaction and also there was a case, where individuals prefer both substrates equally. Organisms showed no escape reaction and were fairly evenly distributed in both halves of the test vessel, it can be assessed that organisms prefer both substrates equally. In testing, the mortality was zero, none of the individuals died, at the conclusion of the test there were not found any dead individuals. Avoidance higher than 80 % didn’t occur; it cannot be said that the substrate is toxic or degraded.

VALIDATION OF HANFORD PERSONNEL AND EXTREMITY DOSIMETERS IN PLUTONIUM ENVIRONMENTS

Energy Technology Data Exchange (ETDEWEB)

Scherpelz, Robert I.; Fix, John J.; Rathbone, Bruce A.

2000-02-10

A study was performed in the Plutonium Finishing Plant to assess the performance of Hanford personnel neutron dosimetry. The study was assessed whole body dosimetry and extremity dosimetry performance. For both parts of the study, the TEPC was used as the principle instrument for characterizing workplace neutron fields. In the whole body study, 12.7-cm-diameter TEPCs were used in ten different locations in the facility. TLD and TED personnel dosimeters were exposed on a water-filled phantom to enable a comparison of TEPC and dosimeter response. In the extremity study, 1.27-cm-diameter TEPCs were exposed inside the fingers of a gloveboxe glove. Extremity dosimeters were wrapped around the TEPCs. The glove was then exposed to six different cans of plutonium, simulating the exposure that a worker's fingers would receive in a glovebox. The comparison of TEPC-measured neutron dose equivalent to TLD-measured gamma dose equivalent provided neutron-to-gamma ratios that can be used to estimate the neutron dose equivalent received by a worker's finger based on the gamma readings of an extremity dosimeter. The study also utilized a Snoopy and detectors based on bubble technology for assessing neutron exposures, providing a comparison of the effectiveness of these instruments for workplace monitoring. The study concludes that the TLD component of the HCND performs adequately overall, with a positive bias of 30%, but exhibits excessive variability in individual results due to instabilities in the algorithm. The TED response was less variable but only 20% of the TEPC reference dose on average because of the low neutron energies involved. The neutron response of the HSD was more variable than the TLD component of the HCND and biased high by a factor of 8 overall due to its calibration to unmoderated 252Cf. The study recommends further work to correct instabilities in the HCND algorithm and to explore the potential shown by the bubble-based dosimeters.

Extreme Science (LBNL Science at the Theater)

Energy Technology Data Exchange (ETDEWEB)

Ajo-Franklin, Caroline; Klein, Spencer; Minor, Andrew; Torok, Tamas

2012-02-27

On Feb. 27, 2012 at the Berkeley Repertory Theatre, four Berkeley Lab scientists presented talks related to extreme science - and what it means to you. Topics include: Neutrino hunting in Antarctica. Learn why Spencer Klein goes to the ends of the Earth to search for these ghostly particles. From Chernobyl to Central Asia, Tamas Torok travels the globe to study microbial diversity in extreme environments. Andrew Minor uses the world's most advanced electron microscopes to explore materials at ultrahigh stresses and in harsh environments. And microbes that talk to computers? Caroline Ajo-Franklin is pioneering cellular-electrical connections that could help transform sunlight into fuel.

Male Youth Perceptions of Violent Extremism: towards a Test of Rational Choice Theory.

Science.gov (United States)

Dhami, Mandeep K; Murray, Jennifer

2016-09-20

Understanding how people perceive the pros and cons of risky behaviors such as terrorism or violent extremism represents a first step in developing research testing rational choice theory aiming to explain and predict peoples' intentions to engage in, or support, these behaviors. Accordingly, the present study provides a qualitative, exploratory analysis of a sample of 57 male youths' perceptions of the benefits and drawbacks of: (a) accessing a violent extremist website, (b) joining a violent extremist group, and (c) leaving such a group. Youth perceived significantly more drawbacks than benefits of joining a violent extremist group (p = .001, d = .46) and accessing a violent extremist website (p = .001, d = .46). The perceived benefits of engagement referred to gaining knowledge/awareness, being part of a group/similar people, and fighting the enemy/for a cause. The drawbacks referred to being exposed to negative material and emotions, having violent/criminal beliefs and behaviors, and getting in trouble with the law. The perceived benefits of disengagement referred to no longer committing illegal acts, and regaining independence/not being manipulated. The drawbacks referred to exposing oneself to harm and reprisal. These findings provide an insight into how male youth think about (dis)engagement in violent extremism, and can inform future quantitative research designed to explain and predict (dis)engagement in violent extremism. Eventually, such research may inform the development of evidence-based prevention and intervention strategies.

Mathematical Analysis of Extremity Immersion Cooling for Brain Temperature Management

National Research Council Canada - National Science Library

Xu, Xiaojiang; Santee, William; Berglund, Larry; Gonzalez, Richard

2004-01-01

.... As blood flow rates and surface-to-volume ratios are generally high in the extremities, heat exchange between the body and the environment through the extremities is an important path for heat exchange...

Comparative Performance of Four Single Extreme Outlier Discordancy Tests from Monte Carlo Simulations

Directory of Open Access Journals (Sweden)

Surendra P. Verma

2014-01-01

Full Text Available Using highly precise and accurate Monte Carlo simulations of 20,000,000 replications and 102 independent simulation experiments with extremely low simulation errors and total uncertainties, we evaluated the performance of four single outlier discordancy tests (Grubbs test N2, Dixon test N8, skewness test N14, and kurtosis test N15 for normal samples of sizes 5 to 20. Statistical contaminations of a single observation resulting from parameters called δ from ±0.1 up to ±20 for modeling the slippage of central tendency or ε from ±1.1 up to ±200 for slippage of dispersion, as well as no contamination (δ=0 and ε=±1, were simulated. Because of the use of precise and accurate random and normally distributed simulated data, very large replications, and a large number of independent experiments, this paper presents a novel approach for precise and accurate estimations of power functions of four popular discordancy tests and, therefore, should not be considered as a simple simulation exercise unrelated to probability and statistics. From both criteria of the Power of Test proposed by Hayes and Kinsella and the Test Performance Criterion of Barnett and Lewis, Dixon test N8 performs less well than the other three tests. The overall performance of these four tests could be summarized as N2≅N15>N14>N8.

Older women with dementia can perform fast alternating forearm movements and performance is correlated with tests of lower extremity function

Directory of Open Access Journals (Sweden)

Bramell-Risberg E

2013-02-01

Full Text Available Eva Bramell-Risberg,1 Gun-Britt Jarnlo,2 Sölve Elmståhl11Division of Geriatric Medicine, 2Division of Physiotherapy, Department of Health Sciences, Lund University, Lund, SwedenBackground: The purpose of this work was to study the performance and reliability of a test of fast alternating forearm movements and its relationship with measures of lower extremity function in older women with dementia.Methods: Fast alternating movements was studied in 26 female patients (mean age 81.7 ± 5.9 years with dementia and 34 controls (mean age 87.5 ± 4.7 years. Subgroup analyses for those aged 80–89 years were performed due to significant differences in the mean ages of the study groups. Test–retest reliability for alternating forearm movements was studied in 11 patients (mean age 80.3 ± 6.7 years and 10 controls (mean age 87.4 ± 1.6 years. Pulses generated were transformed to an analog signal shown on a modified electrocardiogram. Numbers of cycles at 10 and 15 seconds were calculated for the right and left hand. Walking 2 × 15 m and the Get-Up-and Go (GUG test were performed at self-selected and maximal speed. Associations between tests of upper and lower extremity function were sought in eight patients (mean age 85 ± 2.7 years and 16 controls (mean age 85.1 ± 2.8 years and also according to types of dementia in nine patients with probable Alzheimer's disease and 10 patients with other types of dementia.Results: Patients with dementia could perform the test and had significantly fewer cycles (P = 0.02–0.006 at both 10 and 15 seconds compared with controls after age adjustment. A higher number of cycles was associated with higher self-selected walking speeds in patients (r = -0.79. Test–retest reliability for alternating forearm movements was high for both patients (intraclass correlation 0.88–0.94 and controls (intraclass correlation 0.74–0.94.Conclusion: Alternating forearm movements at fast speed can be used as a reliable test in both

The interaction of Plutonium with Bacteria in the Repository Environment

International Nuclear Information System (INIS)

Gillow, J. B.; Francis, A. J.; Lucero, D. A.; Papenguth, H. W.

2000-01-01

Microorganisms in the nuclear waste repository environment may interact with plutonium through (1) sorption, (2) intracellular accumulation, and (3) transformation speciation. These interactions may retard or enhance the mobility of Pu by precipitation reactions, biocolloid formation, or production of more soluble species. Current and planned radioactive waste repository environments, such as deep subsurface halite and granite formations, are considered extreme relative to life processes in the near-surface terrestrial environment. There is a paucity of information on the biotransformation of radionuclides by microorganisms present in such extreme environments. In order to gain a better understanding of the interaction of plutonium with microorganisms present in the waste repository sites we investigated a pure culture (Halomonas sp.) and a mixed culture of bacteria (Haloarcula sinaiiensis, Marinobacter hydrocarbonoclasticus, Altermonas sp., and a γ-proteobacterium) isolated from the Waste Isolation Pilot Plant (WIPP) site and an Acetobacterium sp. from alkaline groundwater at the Grimsel Test Site in Switzerland

Reliability Verification of DBE Environment Simulation Test Facility by using Statistics Method

International Nuclear Information System (INIS)

Jang, Kyung Nam; Kim, Jong Soeg; Jeong, Sun Chul; Kyung Heum

2011-01-01

In the nuclear power plant, all the safety-related equipment including cables under the harsh environment should perform the equipment qualification (EQ) according to the IEEE std 323. There are three types of qualification methods including type testing, operating experience and analysis. In order to environmentally qualify the safety-related equipment using type testing method, not analysis or operation experience method, the representative sample of equipment, including interfaces, should be subjected to a series of tests. Among these tests, Design Basis Events (DBE) environment simulating test is the most important test. DBE simulation test is performed in DBE simulation test chamber according to the postulated DBE conditions including specified high-energy line break (HELB), loss of coolant accident (LOCA), main steam line break (MSLB) and etc, after thermal and radiation aging. Because most DBE conditions have 100% humidity condition, in order to trace temperature and pressure of DBE condition, high temperature steam should be used. During DBE simulation test, if high temperature steam under high pressure inject to the DBE test chamber, the temperature and pressure in test chamber rapidly increase over the target temperature. Therefore, the temperature and pressure in test chamber continue fluctuating during the DBE simulation test to meet target temperature and pressure. We should ensure fairness and accuracy of test result by confirming the performance of DBE environment simulation test facility. In this paper, in order to verify reliability of DBE environment simulation test facility, statistics method is used

A Laboratory of Extremophiles: Iceland Coordination Action for Research Activities on Life in Extreme Environments (CAREX Field Campaign

Directory of Open Access Journals (Sweden)

Robert Hänsch

2013-02-01

Full Text Available Existence of life in extreme environments has been known for a long time, and their habitants have been investigated by different scientific disciplines for decades. However, reports of multidisciplinary research are uncommon. In this paper, we report an interdisciplinary three-day field campaign conducted in the framework of the Coordination Action for Research Activities on Life in Extreme Environments (CAREX FP7EU program, with participation of experts in the fields of life and earth sciences. In situ experiments and sampling were performed in a 20 m long hot springs system of different temperature (57 °C to 100 °C and pH (2 to 4. Abiotic factors were measured to study their influence on the diversity. The CO2 and H2S concentration varied at different sampling locations in the system, but the SO2 remained the same. Four biofilms, mainly composed by four different algae and phototrophic protists, showed differences in photosynthetic activity. Varying temperature of the sampling location affects chlorophyll fluorescence, not only in the microbial mats, but plants (Juncus, indicating selective adaptation to the environmental conditions. Quantitative polymerase chain reaction (PCR, DNA microarray and denaturing gradient gel electrophoresis (DGGE-based analysis in laboratory showed the presence of a diverse microbial population. Even a short duration (30 h deployment of a micro colonizer in this hot spring system led to colonization of microorganisms based on ribosomal intergenic spacer (RISA analysis. Polyphasic analysis of this hot spring system was possible due to the involvement of multidisciplinary approaches.

Defining Population Health Vulnerability Following an Extreme Weather Event in an Urban Pacific Island Environment: Honiara, Solomon Islands

Science.gov (United States)

Natuzzi, Eileen S.; Joshua, Cynthia; Shortus, Matthew; Reubin, Reginald; Dalipanda, Tenneth; Ferran, Karen; Aumua, Audrey; Brodine, Stephanie

2016-01-01

Extreme weather events are common and increasing in intensity in the southwestern Pacific region. Health impacts from cyclones and tropical storms cause acute injuries and infectious disease outbreaks. Defining population vulnerability to extreme weather events by examining a recent flood in Honiara, Solomon Islands, can help stakeholders and policymakers adapt development to reduce future threats. The acute and subacute health impacts following the April 2014 floods were defined using data obtained from hospitals and clinics, the Ministry of Health and in-country World Health Organization office in Honiara. Geographical information system (GIS) was used to assess morbidity and mortality, and vulnerability of the health system infrastructure and households in Honiara. The April flash floods were responsible for 21 acute deaths, 33 injuries, and a diarrhea outbreak that affected 8,584 people with 10 pediatric deaths. A GIS vulnerability assessment of the location of the health system infrastructure and households relative to rivers and the coastline identified 75% of the health infrastructure and over 29% of Honiara's population as vulnerable to future hydrological events. Honiara, Solomon Islands, is a rapidly growing, highly vulnerable urban Pacific Island environment. Evaluation of the mortality and morbidity from the April 2014 floods as well as the infectious disease outbreaks that followed allows public health specialists and policy makers to understand the health system and populations vulnerability to future shocks. Understanding the negative impacts natural disaster have on people living in urban Pacific environments will help the government as well as development partners in crafting resilient adaptation development. PMID:27091867

Adventure and Extreme Sports.

Science.gov (United States)

Gomez, Andrew Thomas; Rao, Ashwin

2016-03-01

Adventure and extreme sports often involve unpredictable and inhospitable environments, high velocities, and stunts. These activities vary widely and include sports like BASE jumping, snowboarding, kayaking, and surfing. Increasing interest and participation in adventure and extreme sports warrants understanding by clinicians to facilitate prevention, identification, and treatment of injuries unique to each sport. This article covers alpine skiing and snowboarding, skateboarding, surfing, bungee jumping, BASE jumping, and whitewater sports with emphasis on epidemiology, demographics, general injury mechanisms, specific injuries, chronic injuries, fatality data, and prevention. Overall, most injuries are related to overuse, trauma, and environmental or microbial exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

Survival in extreme environments – on the current knowledge of adaptations in tardigrades

DEFF Research Database (Denmark)

Møbjerg, Nadja; Halberg, Kenneth Agerlin; Jørgensen, Aslak

2011-01-01

of mechanisms explaining this phenomenon is lacking. Importantly, recent research has shown that tardigrades even in their active states may be extremely tolerant to environmental stress, handling extreme levels of ionizing radiation, large fluctuation in external salinity and avoiding freezing by supercooling...

Grouping of Environments for Testing Navy Bean in Ethiopia ...

African Journals Online (AJOL)

Kassaye

bean (Phaseolus vulgaris L.) lines was tested in a multi-environment variety trial ... of methods available for the analysis of GEI and stability. .... parameters in the kth bilinear term are obtained as the kth component of the .... AMMI ANOVA of grain yield for 16 navy bean lines at fourteen environments during 2010 – 2011 main ...

The benefits of integrating Internet technology with standard communications for telemedicine in extreme environments.

Science.gov (United States)

Harnett, B M; Satava, R; Angood, P; Merriam, N R; Doarn, C R; Merrell, R C

2001-12-01

The ability to continuously monitor the vital signs of a person can be beneficial especially if the environment is hazardous or a person simply has general health concerns. We wanted to ascertain if, by integrating the Internet, ubiquitous switching technologies and off-the-shelf tools, this "suite of services" could provide a topology to enable remote monitoring in extreme and remote locations. An evaluation of this approach was conducted at the base camp of Mount Everest in the spring of 1999. Three climbers were outfitted with wireless, wearable sensors and transmitters for 24 h as they ascended through the Khumbu Icefall toward Camp One. The physiologic data was forwarded to the receiving station at Base Camp where it was forwarded to the U.S. mainland. Two of the three devices delivered physiologic data 95%-100% of the time while the third unit operated at only 78%. According to the climbers, the devices were unobtrusive, however, any additional weight while climbing Everest must provide advantage.

Readiness and Adjustments to School for Children with Intrauterine Growth Restriction (IUGR): An Extreme Test Case Paradigm

Science.gov (United States)

Geva, Ronny; Yosipof, Rina; Eshel, Rina; Leitner, Yael; Valevski, Aviva Fattal; Harel, Shaul

2009-01-01

This long-term, prospective study evaluated repeatedly school readiness and adjustment at kindergarten and first grade of children with extreme intrauterine growth restriction (IUGR; n = 20) in relation to controls (n = 19). Methods included individual testing of cognitive competence, self-perception, motivation, loneliness and academic…

In Situ Raman Spectral Characteristics of Carbon Dioxide in a Deep-Sea Simulator of Extreme Environments Reaching 300 ℃ and 30 MPa.

Science.gov (United States)

Li, Lianfu; Du, Zengfeng; Zhang, Xin; Xi, Shichuan; Wang, Bing; Luan, Zhendong; Lian, Chao; Yan, Jun

2018-01-01

Deep-sea carbon dioxide (CO 2 ) plays a significant role in the global carbon cycle and directly affects the living environment of marine organisms. In situ Raman detection technology is an effective approach to study the behavior of deep-sea CO 2 . However, the Raman spectral characteristics of CO 2 can be affected by the environment, thus restricting the phase identification and quantitative analysis of CO 2 . In order to study the Raman spectral characteristics of CO 2 in extreme environments (up to 300 ℃ and 30 MPa), which cover most regions of hydrothermal vents and cold seeps around the world, a deep-sea extreme environment simulator was developed. The Raman spectra of CO 2 in different phases were obtained with Raman insertion probe (RiP) system, which was also used in in situ Raman detection in the deep sea carried by remotely operated vehicle (ROV) "Faxian". The Raman frequency shifts and bandwidths of gaseous, liquid, solid, and supercritical CO 2 and the CO 2 -H 2 O system were determined with the simulator. In our experiments (0-300 ℃ and 0-30 MPa), the peak positions of the symmetric stretching modes of gaseous CO 2, liquid CO 2 , and supercritical CO 2 shift approximately 0.6 cm -1 (1387.8-1388.4 cm -1 ), 0.7 cm -1 (1385.5-1386.2 cm -1 ), and 2.5 cm -1 (1385.7-1388.2 cm -1 ), and those of the bending modes shift about 1.0 cm -1 (1284.7-1285.7 cm -1 ), 1.9 cm -1 (1280.1-1282.0 cm -1 ), and 4.4 cm -1 (1281.0-1285.4 cm -1 ), respectively. The Raman spectral characteristics of the CO 2 -H 2 O system were also studied under the same conditions. The peak positions of dissolved CO 2 varied approximately 4.5 cm -1 (1282.5-1287.0 cm -1 ) and 2.4 cm -1 (1274.4-1276.8 cm -1 ) for each peak. In comparison with our experiment results, the phases of CO 2 in extreme conditions (0-3000 m and 0-300 ℃) can be identified with the Raman spectra collected in situ. This qualitative research on CO 2 can also support the

Modeling extreme PM10 concentration in Malaysia using generalized extreme value distribution

Science.gov (United States)

Hasan, Husna; Mansor, Nadiah; Salleh, Nur Hanim Mohd

2015-05-01

Extreme PM10 concentration from the Air Pollutant Index (API) at thirteen monitoring stations in Malaysia is modeled using the Generalized Extreme Value (GEV) distribution. The data is blocked into monthly selection period. The Mann-Kendall (MK) test suggests a non-stationary model so two models are considered for the stations with trend. The likelihood ratio test is used to determine the best fitted model and the result shows that only two stations favor the non-stationary model (Model 2) while the other eleven stations favor stationary model (Model 1). The return level of PM10 concentration that is expected to exceed the maximum once within a selected period is obtained.

Relationship between upper extremity kinesthetic sense and writing performance by students with low vision.

Science.gov (United States)

Aki, Esra; Atasavun, Songül; Kayihan, Holya

2008-06-01

Kinesthetic sense plays an important role in writing. Children with low vision lack sensory input from the environment given their loss of vision. This study assessed the effect of upper extremity kinesthetic sense on writing function in two groups, one of students with low vision (9 girls and 11 boys, 9.4 +/- 1.9 yr. of age) and one of sighted students (10 girls and 10 boys, 10.1 +/- 1.3 yr. of age). All participants were given the Kinesthesia Test and Jebsen Hand Function Test-Writing subtest. Students with low vision scored lower on kinesthetic perception and writing performance than sighted peers. The correlation between scores for writing performance and upper extremity kinesthetic sense in the two groups was significant (r = -.34). The probability of deficiencies in kinesthetic information in students with low vision must be remembered.

Anaerobic metabolism at thermal extremes: a metabolomic test of the oxygen limitation hypothesis in an aquatic insect.

Science.gov (United States)

Verberk, W C E P; Sommer, U; Davidson, R L; Viant, M R

2013-10-01

Thermal limits in ectotherms may arise through a mismatch between supply and demand of oxygen. At higher temperatures, the ability of their cardiac and ventilatory activities to supply oxygen becomes insufficient to meet their elevated oxygen demand. Consequently, higher levels of oxygen in the environment are predicted to enhance tolerance of heat, whereas reductions in oxygen are expected to reduce thermal limits. Here, we extend previous research on thermal limits and oxygen limitation in aquatic insect larvae and directly test the hypothesis of increased anaerobic metabolism and lower energy status at thermal extremes. We quantified metabolite profiles in stonefly nymphs under varying temperatures and oxygen levels. Under normoxia, the concept of oxygen limitation applies to the insects studied. Shifts in the metabolome of heat-stressed stonefly nymphs clearly indicate the onset of anaerobic metabolism (e.g., accumulation of lactate, acetate, and alanine), a perturbation of the tricarboxylic acid cycle (e.g., accumulation of succinate and malate), and a decrease in energy status (e.g., ATP), with corresponding decreases in their ability to survive heat stress. These shifts were more pronounced under hypoxic conditions, and negated by hyperoxia, which also improved heat tolerance. Perturbations of metabolic pathways in response to either heat stress or hypoxia were found to be somewhat similar but not identical. Under hypoxia, energy status was greatly compromised at thermal extremes, but energy shortage and anaerobic metabolism could not be conclusively identified as the sole cause underlying thermal limits under hyperoxia. Metabolomics proved useful for suggesting a range of possible mechanisms to explore in future investigations, such as the involvement of leaking membranes or free radicals. In doing so, metabolomics provided a more complete picture of changes in metabolism under hypoxia and heat stress.

Prevention through policy: Urban macroplastic leakages to the marine environment during extreme rainfall events

OpenAIRE

Axelsson, Charles; van Sebille, Erik

2017-01-01

The leakage of large plastic litter (macroplastics) into the ocean is a major environmental problem. A significant fraction of this leakage originates from coastal cities, particularly during extreme rainfall events. As coastal cities continue to grow, finding ways to reduce this macroplastic leakage is extremely pertinent. Here, we explore why and how coastal cities can reduce macroplastic leakages during extreme rainfall events. Using nine global cities as a basis, we establish that while c...

Atomic collisions under extreme conditions in space

International Nuclear Information System (INIS)

Itikawa, Yukikazu

1987-01-01

In space, atoms and molecules are often placed under the extreme conditions which are very difficult to be realized on Earth. For instance, extremely hot and dense plasmas are found in and around various stellar objects (e.g., neutron stars) on one hand and extremely cold and diffuse gases prevail in interstellar space on the other. There is so strong a magnetic field that electron clouds in atoms and molecules are distorted. The study of atomic collisions under the extreme conditions is not only helpful in understanding the astrophysical environment but also reveals new aspects of the physics of atoms and molecules. This paper is an invitation to the study. (References are not exhaustive but only provide a clue with which more details can be found.) (author)

Validity and Reliability of Baseline Testing in a Standardized Environment.

Science.gov (United States)

Higgins, Kathryn L; Caze, Todd; Maerlender, Arthur

2017-08-11

The Immediate Postconcussion Assessment and Cognitive Testing (ImPACT) is a computerized neuropsychological test battery commonly used to determine cognitive recovery from concussion based on comparing post-injury scores to baseline scores. This model is based on the premise that ImPACT baseline test scores are a valid and reliable measure of optimal cognitive function at baseline. Growing evidence suggests that this premise may not be accurate and a large contributor to invalid and unreliable baseline test scores may be the protocol and environment in which baseline tests are administered. This study examined the effects of a standardized environment and administration protocol on the reliability and performance validity of athletes' baseline test scores on ImPACT by comparing scores obtained in two different group-testing settings. Three hundred-sixty one Division 1 cohort-matched collegiate athletes' baseline data were assessed using a variety of indicators of potential performance invalidity; internal reliability was also examined. Thirty-one to thirty-nine percent of the baseline cases had at least one indicator of low performance validity, but there were no significant differences in validity indicators based on environment in which the testing was conducted. Internal consistency reliability scores were in the acceptable to good range, with no significant differences between administration conditions. These results suggest that athletes may be reliably performing at levels lower than their best effort would produce. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Millimeter waves or extremely high frequency electromagnetic fields in the environment: what are their effects on bacteria?

Science.gov (United States)

Soghomonyan, Diana; Trchounian, Karen; Trchounian, Armen

2016-06-01

Millimeter waves (MMW) or electromagnetic fields of extremely high frequencies at low intensity is a new environmental factor, the level of which is increased as technology advance. It is of interest that bacteria and other cells might communicate with each other by electromagnetic field of sub-extremely high frequency range. These MMW affected Escherichia coli and many other bacteria, mainly depressing their growth and changing properties and activity. These effects were non-thermal and depended on different factors. The significant cellular targets for MMW effects could be water, cell plasma membrane, and genome. The model for the MMW interaction with bacteria is suggested; a role of the membrane-associated proton FOF1-ATPase, key enzyme of bioenergetic relevance, is proposed. The consequences of MMW interaction with bacteria are the changes in their sensitivity to different biologically active chemicals, including antibiotics. Novel data on MMW effects on bacteria and their sensitivity to different antibiotics are presented and discussed; the combined action of MMW and antibiotics resulted with more strong effects. These effects are of significance for understanding changed metabolic pathways and distinguish role of bacteria in environment; they might be leading to antibiotic resistance in bacteria. The effects might have applications in the development of technique, therapeutic practices, and food protection technology.

E.X.T.R.E.M.E. project. Launch

International Nuclear Information System (INIS)

Eyrolle, F.; Charmasson, S.; Masson, O.

2005-01-01

Due to the drastic decrease in artificial radioactivity levels from primary sources such as atmospheric fallout or industrial releases, radioactive storages constituted in the past within several environmental compartments act today as non negligible secondary sources. These delayed sources are particularly active during extreme weather or climatic events such as rainfalls or atmospheric deposits, floods, storms, etc...that may remove important mass, generate activity levels higher than the predicted ones from modeling based on mean transfer process, and produce in a couple of hours or days fluxes similar to those accrued over several month or years. Extreme aims at assessing the consequences on man and its environment of natural events that generate extreme radioactive stocks and/or fluxes within several environmental compartments (atmosphere, soils, rivers, coastal marine environment and deep sea areas). (authors)

Environmental Testing of Tritium-Phosphor Glass Vials for Use in Long-Life Radioisotope Power Conversion Units

Science.gov (United States)

Zemcov, Michael; Cardona, Pedro; Parkus, James; Patru, Dorin; Yost, Valerie

2017-01-01

Power generation in extreme environments, such as the outer solar system, the night side of planets, or other low-illumination environments, currently presents a technology gap that challenges NASA's ambitious scientific goals. We are developing a radioisotope power cell (RPC) that utilizes commercially available tritium light sources and standard 1.85 eV InGaP2 photovoltaic cells to convert beta particle energy to electric energy. In the test program described here, we perform environmental tests on commercially available borosilicate glass vials internally coated with a ZnS luminescent phosphor that are designed to contain gaseous tritium in our proposed power source. Such testing is necessary to ensure that the glass containing the radioactive tritium is capable of withstanding the extreme environments of launch and space for extended periods of time.

Automaton Rover for Extreme Environments, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Venus, with its sulfuric acid clouds, temperatures of over 450', and surface pressure of 92 bar, is one of the most hostile planetary environments in the solar...

Performance Tests of a Mechanical Pump in Sodium Environment

Energy Technology Data Exchange (ETDEWEB)

Cho, Chungho; Kim, Jong-Man; Ko, Yung Joo; Kim, Byeongyeon; Cho, Youngil; Jung, Min-Hwan; Gam, Da-Young; Lee, Yong Bum; Jeong, Ji-Young; Kim, Jong-Bum [KAERI, Daejeon (Korea, Republic of)

2016-05-15

Water is often selected as a surrogate test fluid because it is not only cheap, easily available and easy to handle but also its important hydraulic properties (density and kinematic viscosity) are very similar to that of the sodium. Nevertheless, to ensure the performance, safety, and operability of major components before its installation in the SFR, a series of demonstration experiments of some components in sodium environment should be positively necessary. So, SFR NSSS System Design Division of Korea Atomic Energy Research Institute (KAERI) built various sodium experimental facilities, especially STELLA-1 in 2012. STELLA-1 (Sodium inTegral Effect test Loop for safety simuLation and Assessment) is a large-scale separated effect test facility for demonstrating the thermal-hydraulic performances of major components such as a Sodium-to-Sodium heat exchanger (DHX), Sodium-to-Air heat exchanger (AHX) of the decay heat removal system, and mechanical sodium pump of the primary heat transport system (PHTS). The mechanical pump in-sodium performance test was successfully performed with good reproducibility of the experiment and data to compare hydraulic characteristic of a mechanical pump in-water was collected. In effect of temperature variation on the pump pressure head, reduction of pump pressure head at 250℃ by 0.57% of that of 300℃ maybe the result of an increase in sodium viscosity by 13.6% according to operating temperature decrease by 50℃. Also, we confirmed that the more flywheel weight, the longer halving time and the more initial flow rate when the pump seized, the shorter halving time. The results of the mechanical pump performance test data in sodium environment will be used to compare with that of the in water environment after the evaluation of measurement uncertainty for tests.

Standard Test Method for Saltwater Pressure Immersion and Temperature Testing of Photovoltaic Modules for Marine Environments

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 This test method provides a procedure for determining the ability of photovoltaic modules to withstand repeated immersion or splash exposure by seawater as might be encountered when installed in a marine environment, such as a floating aid-to-navigation. A combined environmental cycling exposure with modules repeatedly submerged in simulated saltwater at varying temperatures and under repetitive pressurization provides an accelerated basis for evaluation of aging effects of a marine environment on module materials and construction. 1.2 This test method defines photovoltaic module test specimens and requirements for positioning modules for test, references suitable methods for determining changes in electrical performance and characteristics, and specifies parameters which must be recorded and reported. 1.3 This test method does not establish pass or fail levels. The determination of acceptable or unacceptable results is beyond the scope of this test method. 1.4 The values stated in SI units are to be ...

Stationary and non-stationary extreme value modeling of extreme temperature in Malaysia

Science.gov (United States)

Hasan, Husna; Salleh, Nur Hanim Mohd; Kassim, Suraiya

2014-09-01

Extreme annual temperature of eighteen stations in Malaysia is fitted to the Generalized Extreme Value distribution. Stationary and non-stationary models with trend are considered for each station and the Likelihood Ratio test is used to determine the best-fitting model. Results show that three out of eighteen stations i.e. Bayan Lepas, Labuan and Subang favor a model which is linear in the location parameter. A hierarchical cluster analysis is employed to investigate the existence of similar behavior among the stations. Three distinct clusters are found in which one of them consists of the stations that favor the non-stationary model. T-year estimated return levels of the extreme temperature are provided based on the chosen models.

40 CFR 355.12 - What quantities of extremely hazardous substances trigger emergency planning requirements?

Science.gov (United States)

2010-07-01

... EMERGENCY PLANNING AND NOTIFICATION Emergency Planning Who Must Comply § 355.12 What quantities of extremely... 40 Protection of Environment 27 2010-07-01 2010-07-01 false What quantities of extremely hazardous substances trigger emergency planning requirements? 355.12 Section 355.12 Protection of Environment...

Nonhydrostatic and surfbeat model predictions of extreme wave run-up in fringing reef environments

Science.gov (United States)

Lashley, Christopher H.; Roelvink, Dano; van Dongeren, Ap R.; Buckley, Mark L.; Lowe, Ryan J.

2018-01-01

The accurate prediction of extreme wave run-up is important for effective coastal engineering design and coastal hazard management. While run-up processes on open sandy coasts have been reasonably well-studied, very few studies have focused on understanding and predicting wave run-up at coral reef-fronted coastlines. This paper applies the short-wave resolving, Nonhydrostatic (XB-NH) and short-wave averaged, Surfbeat (XB-SB) modes of the XBeach numerical model to validate run-up using data from two 1D (alongshore uniform) fringing-reef profiles without roughness elements, with two objectives: i) to provide insight into the physical processes governing run-up in such environments; and ii) to evaluate the performance of both modes in accurately predicting run-up over a wide range of conditions. XBeach was calibrated by optimizing the maximum wave steepness parameter (maxbrsteep) in XB-NH and the dissipation coefficient (alpha) in XB-SB) using the first dataset; and then applied to the second dataset for validation. XB-NH and XB-SB predictions of extreme wave run-up (Rmax and R2%) and its components, infragravity- and sea-swell band swash (SIG and SSS) and shoreline setup (), were compared to observations. XB-NH more accurately simulated wave transformation but under-predicted shoreline setup due to its exclusion of parameterized wave-roller dynamics. XB-SB under-predicted sea-swell band swash but overestimated shoreline setup due to an over-prediction of wave heights on the reef flat. Run-up (swash) spectra were dominated by infragravity motions, allowing the short-wave (but not wave group) averaged model (XB-SB) to perform comparably well to its more complete, short-wave resolving (XB-NH) counterpart. Despite their respective limitations, both modes were able to accurately predict Rmax and R2%.

Morphological selection in an extreme flow environment: body shape and waterfall-climbing success in the Hawaiian stream fish Sicyopterus stimpsoni.

Science.gov (United States)

Blob, Richard W; Bridges, William C; Ptacek, Margaret B; Maie, Takashi; Cediel, Roberto A; Bertolas, Morgan M; Julius, Matthew L; Schoenfuss, Heiko L

2008-12-01

Flow characteristics are a prominent factor determining body shapes in aquatic organisms, and correlations between body shape and ambient flow regimes have been established for many fish species. In this study, we investigated the potential for a brief period of extreme flow to exert selection on the body shape of juvenile climbing Hawaiian gobiid fishes. Because of an amphidromous life history, juvenile gobies that complete an oceanic larval phase return to freshwater habitats, where they become adults. Returning juveniles often must scale waterfalls (typically with the use of a ventral sucker) in order to reach the habitats they will use as adults, thereby exposing these animals to brief periods of extreme velocities of flow. Hydrodynamic theory predicts that bodies with larger suckers and with lower heights that reduce drag would have improved climbing success and, thus, be well suited to meet the demands of the flows in waterfalls. To test the potential for the flow environment of waterfalls to impose selection that could contribute to differences in body shape between islands, we subjected juvenile Sicyopterus stimpsoni to climbing trials up artificial waterfalls (∼100 body lengths) and measured differences in body shape between successful and unsuccessful climbers. Waterfalls appear to represent a significant selective barrier to these fishes, as nearly 30% failed our climbing test. However, the effects of selection on morphology were not straightforward, as significant differences in shape between successful and unsuccessful climbers did not always match hydrodynamic predictions. In both selection experiments and in adult fish collected from habitats with different prevailing conditions of flow (the islands of Hawai'i versus Kaua'i), lower head heights were associated with exposure to high-flow regimes, as predicted by hydrodynamic theory. Thus, a premium appears to be placed on the reduction of drag via head morphology throughout the ontogeny of this

Extreme low temperature tolerance in woody plants

Directory of Open Access Journals (Sweden)

George Richard Strimbeck

2015-10-01

Full Text Available Woody plants in boreal to arctic environments and high mountains survive prolonged exposure to temperatures below -40˚C and minimum temperatures below -60˚C, and laboratory tests show that many of these species can also survive immersion in liquid nitrogen at -196˚C. Studies of biochemical changes that occur during acclimation, including recent proteomic and metabolomic studies, have identified changes in carbohydrate and compatible solute concentrations, membrane lipid composition, and proteins, notably dehydrins, that may have important roles in survival at extreme low temperature. Consideration of the biophysical mechanisms of membrane stress and strain lead to the following hypotheses for cellular and molecular mechanisms of survival at extreme low temperature: 1. Changes in lipid composition stabilize membranes at temperatures above the lipid phase transition temperature (-20 to 30˚C, preventing phase changes that result in irreversible injury. 2. High concentrations of oligosaccharides promote vitrification or high viscosity in the cytoplasm in freeze-dehydrated cells, which would prevent deleterious interactions between membranes. 3. Dehydrins bind membranes and further promote vitrification or act stearically to prevent membrane-membrane interactions.

The extreme environments and their microbes as models for extraterrestrial life

Science.gov (United States)

Seckbach, J.; Oren, A.; Chela-Flores, J.

2008-09-01

Life exists almost everywhere on Earth. Presence of liquid water is a prerequisite for life (Oren, 2008). Living organisms are not only found in `normal' habitats (from the anthropocentric view). Many types, especially of microorganisms, not only tolerate harsh environmental conditions, but even thive in them. Such organisms that resist very harsh physical and chemical conditions in their habitats are termed `extremophiles'. Some extremophilic microorganisms are able to overcome more than one type of extreme conditions in their environment. For example, some `polyextremophiles' grow under hundreds of atmospheres of hydrostatic pressure (barophiles) and at very low, or alternatively at very high temperatures. In many hot springs there are acido-thermophiles that tolerate elevated temperatures and very low pH levels (e.g. the Cyanidium caldarium group, see Seckbach 1994). Members of Cyanidium are able to thrive in pure CO2, a condition not tolerated by most algae (Seckbach et al., 1970). Some thermophilic Archaea grow at temperatures up to 1130C and possibly even higher. In the Arctic and Antarctic regions and in the permafrost region in Siberia there are cold-loving microorganisms (psychrophiles) which are able to grow at -200C. Many types of Bacteria and Archaea tolerate extreme dryness, and spores of Bacillus and relatives that have been encapsulated within salt crystals may have survived in a dormant state for thousands and even millions of years, and still can be revived today. Other extremophiles tolerate salt concentrations up to saturation. Halophilic microorganisms such as found in the Dead Sea or in the Great Salt Lake have developed different strategies to cope with the high osmotic pressure of their environment. Some (e.g. the unicellular green alga Dunaliella salina) balance the salts in their medium by accumulating organic compounds such as glycerol. Others (halophilic Archaea of the order Halobacteriales, as well as a few representatives of the

TESTING THE APODIZED PUPIL LYOT CORONAGRAPH ON THE LABORATORY FOR ADAPTIVE OPTICS EXTREME ADAPTIVE OPTICS TESTBED

International Nuclear Information System (INIS)

Thomas, Sandrine J.; Dillon, Daren; Gavel, Donald; Soummer, Remi; Macintosh, Bruce; Sivaramakrishnan, Anand

2011-01-01

We present testbed results of the Apodized Pupil Lyot Coronagraph (APLC) at the Laboratory for Adaptive Optics (LAO). These results are part of the validation and tests of the coronagraph and of the Extreme Adaptive Optics (ExAO) for the Gemini Planet Imager (GPI). The apodizer component is manufactured with a halftone technique using black chrome microdots on glass. Testing this APLC (like any other coronagraph) requires extremely good wavefront correction, which is obtained to the 1 nm rms level using the microelectricalmechanical systems (MEMS) technology, on the ExAO visible testbed of the LAO at the University of Santa Cruz. We used an APLC coronagraph without central obstruction, both with a reference super-polished flat mirror and with the MEMS to obtain one of the first images of a dark zone in a coronagraphic image with classical adaptive optics using a MEMS deformable mirror (without involving dark hole algorithms). This was done as a complementary test to the GPI coronagraph testbed at American Museum of Natural History, which studied the coronagraph itself without wavefront correction. Because we needed a full aperture, the coronagraph design is very different from the GPI design. We also tested a coronagraph with central obstruction similar to that of GPI. We investigated the performance of the APLC coronagraph and more particularly the effect of the apodizer profile accuracy on the contrast. Finally, we compared the resulting contrast to predictions made with a wavefront propagation model of the testbed to understand the effects of phase and amplitude errors on the final contrast.

Testing Applications in MANET Environments through Emulation

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Pietro Manzoni

2009-01-01

Full Text Available Mobile Ad Hoc Network solution testing is typically done using simulation. The simulated code is generally a simplified version of the real code, and thus code porting to actual operating systems lacks a strong validation. In this work we present Castadiva, a test-bed architecture that allows validating software solutions for real ad hoc network environments using low-cost, off-the-shelf devices and open source software. Castadiva is also compatible with the ns-2 simulator, allowing a combined and more complete evaluation. In this work we present our tool and the results obtained when evaluating videocalls in different scenarios, both static and dynamic.

Artificial intelligence in a mission operations and satellite test environment

Science.gov (United States)

Busse, Carl

1988-01-01

A Generic Mission Operations System using Expert System technology to demonstrate the potential of Artificial Intelligence (AI) automated monitor and control functions in a Mission Operations and Satellite Test environment will be developed at the National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory (JPL). Expert system techniques in a real time operation environment are being studied and applied to science and engineering data processing. Advanced decommutation schemes and intelligent display technology will be examined to develop imaginative improvements in rapid interpretation and distribution of information. The Generic Payload Operations Control Center (GPOCC) will demonstrate improved data handling accuracy, flexibility, and responsiveness in a complex mission environment. The ultimate goal is to automate repetitious mission operations, instrument, and satellite test functions by the applications of expert system technology and artificial intelligence resources and to enhance the level of man-machine sophistication.

Investigating Extreme Lifestyles through Mangrove Transcriptomics

Science.gov (United States)

Dassanayake, Maheshi

2009-01-01

Mangroves represent phylogenetically diverse taxa in tropical coastal terrestrial habitats. They are extremophiles, evolutionarily adapted to tolerate flooding, anoxia, high temperatures, wind, and high and extremely variable salt conditions in typically resource-poor environments. The genetic basis for these adaptations is, however, virtually…

[The heart in extreme sports: hyperbaric activity and microgravity].

Science.gov (United States)

Berrettini, Umberto; Landolfi, Angelo; Patteri, Giovanna

2008-10-01

The study of the cardiovascular and respiratory modifications in extreme environments could be useful for the understanding of the adaptive mechanisms of the body in particular conditions. The knowledge of how different environmental conditions in terms of extreme pressure, temperature and gravity modify the neurovegetative and cardiovascular system could be useful in daily practice for hypobaric and hyperbaric sports.

Muscle Strength Is a Poor Screening Test for Predicting Lower Extremity Injuries in Professional Male Soccer Players: A 2-Year Prospective Cohort Study.

Science.gov (United States)

Bakken, Arnhild; Targett, Stephen; Bere, Tone; Eirale, Cristiano; Farooq, Abdulaziz; Mosler, Andrea B; Tol, Johannes L; Whiteley, Rod; Khan, Karim M; Bahr, Roald

2018-03-01

Lower extremity muscle strength tests are commonly used to screen for injury risk in professional soccer. However, there is limited evidence on the ability of such tests in predicting future injuries. To examine the association between hip and thigh muscle strength and the risk of lower extremity injuries in professional male soccer players. Case-control study; Level of evidence, 3. Professional male soccer players from 14 teams in Qatar underwent a comprehensive strength assessment at the beginning of the 2013/2014 and 2014/2015 seasons. Testing consisted of concentric and eccentric quadriceps and hamstring isokinetic peak torques, eccentric hip adduction and abduction forces, and bilateral isometric adductor force (squeeze test at 45°). Time-loss injuries and exposure in training and matches were registered prospectively by club medical staff throughout each season. Univariate and multivariate Cox regression analyses were used to calculate hazard ratios (HRs) with 95% CIs. In total, 369 players completed all strength tests and had registered injury and exposure data. Of these, 206 players (55.8%) suffered 538 lower extremity injuries during the 2 seasons; acute muscle injuries were the most frequent. Of the 20 strength measures examined, greater quadriceps concentric peak torque at 300 deg/s (HR, 1.005 [95% CI, 1.00-1.01]; P = .037) was the only strength measure identified as significantly associated with a risk of lower extremity injuries in multivariate analysis. Greater quadriceps concentric peak torque at 60 deg/s (HR, 1.004 [95% CI, 1.00-1.01]; P = .026) was associated with the risk of overuse injuries, and greater bilateral adductor strength adjusted for body weight (HR, 0.75 [95% CI, 0.57-0.97; P = .032) was associated with a lower risk for any knee injury. Receiver operating characteristic curve analyses indicated poor predictive ability of the significant strength variables (area under the curve, 0.45-0.56). There was a weak association with the risk of

Microbial iron management mechanisms in extremely acidic environments: comparative genomics evidence for diversity and versatility

Directory of Open Access Journals (Sweden)

Nieto Pamela A

2008-11-01

uptake systems could reflect their obligatory occupation of extremely low pH environments where high concentrations of soluble iron may always be available and were oxidized sulfur species might not compromise iron speciation dynamics. Presence of bacterioferritin in the Acidithiobacilli, polyphosphate accumulation functions and variants of FieF-like diffusion facilitators in both Acidithiobacilli and Leptospirilla, indicate that they may remove or store iron under conditions of variable availability. In addition, the Fe(II-oxidizing capacity of both A. ferrooxidans and Leptospirilla could itself be a way to evade iron stress imposed by readily available Fe(II ions at low pH. Fur regulatory sites have been predicted for a number of gene clusters including iron related and non-iron related functions in both the Acidithiobacilli and Leptospirilla, laying the foundation for the future discovery of iron regulated and iron-phosphate coordinated regulatory control circuits. Conclusion In silico analyses of the genomes of acidophilic bacteria are beginning to tease apart the mechanisms that mediate iron uptake and homeostasis in low pH environments. Initial models pinpoint significant differences in abundance and diversity of iron management mechanisms between Leptospirilla and Acidithiobacilli, and begin to reveal how these two groups respond to iron cycling and iron fluctuations in naturally acidic environments and in industrial operations. Niche partitions and ecological successions between acidophilic microorganisms may be partially explained by these observed differences. Models derived from these analyses pave the way for improved hypothesis testing and well directed experimental investigation. In addition, aspects of these models should challenge investigators to evaluate alternative iron management strategies in non-acidophilic model organisms.

Extreme ground motions and Yucca Mountain

Science.gov (United States)

Hanks, Thomas C.; Abrahamson, Norman A.; Baker, Jack W.; Boore, David M.; Board, Mark; Brune, James N.; Cornell, C. Allin; Whitney, John W.

2013-01-01

Yucca Mountain is the designated site of the underground repository for the United States' high-level radioactive waste (HLW), consisting of commercial and military spent nuclear fuel, HLW derived from reprocessing of uranium and plutonium, surplus plutonium, and other nuclear-weapons materials. Yucca Mountain straddles the western boundary of the Nevada Test Site, where the United States has tested nuclear devices since the 1950s, and is situated in an arid, remote, and thinly populated region of Nevada, ~100 miles northwest of Las Vegas. Yucca Mountain was originally considered as a potential underground repository of HLW because of its thick units of unsaturated rocks, with the repository horizon being not only ~300 m above the water table but also ~300 m below the Yucca Mountain crest. The fundamental rationale for a geologic (underground) repository for HLW is to securely isolate these materials from the environment and its inhabitants to the greatest extent possible and for very long periods of time. Given the present climate conditions and what is known about the current hydrologic system and conditions around and in the mountain itself, one would anticipate that the rates of infiltration, corrosion, and transport would be very low—except for the possibility that repository integrity might be compromised by low-probability disruptive events, which include earthquakes, strong ground motion, and (or) a repository-piercing volcanic intrusion/eruption. Extreme ground motions (ExGM), as we use the phrase in this report, refer to the extremely large amplitudes of earthquake ground motion that arise at extremely low probabilities of exceedance (hazard). They first came to our attention when the 1998 probabilistic seismic hazard analysis for Yucca Mountain was extended to a hazard level of 10-8/yr (a 10-4/yr probability for a 104-year repository “lifetime”). The primary purpose of this report is to summarize the principal results of the ExGM research program

Corrosion testing of type 304L stainless steel in tuff groundwater environments

International Nuclear Information System (INIS)

Westerman, R.E.; Pitman, S.G.; Haberman, J.H.

1987-11-01

The stress-corrosion cracking (SCC) resistance of Type 304L stainless steel (SS) to elevated temperatures in tuff rock and tuff groundwater environments was determined under irradiated and nonirradiated conditions using U-bend specimens and slow-strain-rate tests. The steel was tested both in the solution-annealed condition and after sensitization heat treatments. The material was found to be susceptible to SCC in both the solution-annealed and solution-annealed-and-sensitized conditions when exposed to an irradiated crushed tuff rock environment containing air and water vapor at 90 0 C. A similar exposure at 50 0 C did not result in failure after a 25-month test duration. Specimens of sensitized 304 SS conditioned with a variety of sensitization heat treatments resisted failure during a test of 1-year duration in which a nonirradiated environment of tuff rock and groundwater held at 200 0 C was allowed to boil to dryness on a cyclical basis. All specimens of sensitized 304 SS exposed to this environment failed. Slow-strain-rate studies were performed on 304L, 304, and 316L SS specimens. The 304L SS was tested in J-13 well water at 150 0 C, and the 316L SS at 95 0 C. Neither material showed evidence of SCC in these tests. Sensitized 304 SS did exhibit SCC in J-13 well water in tests conducted at 150 0 C. 12 refs., 27 figs., 13 tabs

Rotating Arc Jet Test Model: Time-Accurate Trajectory Heat Flux Replication in a Ground Test Environment

Science.gov (United States)

Laub, Bernard; Grinstead, Jay; Dyakonov, Artem; Venkatapathy, Ethiraj

2011-01-01

Though arc jet testing has been the proven method employed for development testing and certification of TPS and TPS instrumentation, the operational aspects of arc jets limit testing to selected, but constant, conditions. Flight, on the other hand, produces timevarying entry conditions in which the heat flux increases, peaks, and recedes as a vehicle descends through an atmosphere. As a result, we are unable to "test as we fly." Attempts to replicate the time-dependent aerothermal environment of atmospheric entry by varying the arc jet facility operating conditions during a test have proven to be difficult, expensive, and only partially successful. A promising alternative is to rotate the test model exposed to a constant-condition arc jet flow to yield a time-varying test condition at a point on a test article (Fig. 1). The model shape and rotation rate can be engineered so that the heat flux at a point on the model replicates the predicted profile for a particular point on a flight vehicle. This simple concept will enable, for example, calibration of the TPS sensors on the Mars Science Laboratory (MSL) aeroshell for anticipated flight environments.

Extreme conditions (p, T, H)

Energy Technology Data Exchange (ETDEWEB)

Mesot, J [Lab. for Neutron Scattering ETH Zurich, Zurich (Switzerland) and Paul Scherrer Institute, Villigen (Switzerland)

1996-11-01

The aim of this paper is to summarize the sample environment which will be accessible at the SINQ. In order to illustrate the type of experiments which will be feasible under extreme conditions of temperature, magnetic field and pressure at the SINQ a few selected examples are also given. (author) 7 figs., 14 refs.

Non-invasive neurosensory testing used to diagnose and confirm successful surgical management of lower extremity deep distal posterior compartment syndrome

Directory of Open Access Journals (Sweden)

Guyton Gregory P

2009-05-01

Full Text Available Abstract Background Chronic exertional compartment syndrome (CECS is characterized by elevated pressures within a closed space of an extremity muscular compartment, causing pain and/or disability by impairing the neuromuscular function of the involved compartment. The diagnosis of CECS is primarily made on careful history and physical exam. The gold standard test to confirm the diagnosis of CECS is invasive intra-compartmental pressure measurements. Sensory nerve function is often diminished during symptomatic periods of CECS. Sensory nerve function can be documented with the use of non-painful, non-invasive neurosensory testing. Methods Non-painful neurosensory testing of the myelinated large sensory nerve fibers of the lower extremity were obtained with the Pressure Specified Sensory Device™ in a 25 year old male with history and invasive compartment pressures consistent with CECS both before and after running on a tread mill. After the patient's first operation to release the deep distal posterior compartment, the patient failed to improve. Repeat sensory testing revealed continued change in his function with exercise. He was returned to the operating room where a repeat procedure revealed that the deep posterior compartment was not completely released due to an unusual anatomic variant, and therefore complete release was accomplished. Results The patient's symptoms numbness in the plantar foot and pain in the distal calf improved after this procedure and his repeat sensory testing performed before and after running on the treadmill documented this improvement. Conclusion This case report illustrates the principal that non-invasive neurosensory testing can detect reversible changes in sensory nerve function after a provocative test and may be a helpful non-invasive technique to managing difficult cases of persistent lower extremity symptoms after failed decompressive fasciotomies for CECS. It can easily be performed before and after

Extreme testing of undiluted e-cigarette aerosol in vitro using an Ames air-agar-interface technique.

Science.gov (United States)

Thorne, D; Hollings, M; Seymour, A; Adamson, J; Dalrymple, A; Ballantyne, M; Gaca, M

2018-04-01

There is a growing consensus that e-cigarettes hold the potential for reducing the harm associated with cigarette smoking. Recently published studies have reported in vitro testing of e-cigarettes, demonstrating reduced toxicological and biological effects. Few studies however have reported the use of e-cigarettes under extreme testing conditions. To assess the full mutagenic potential of a commercially available electronic-cigarette (Vype ePen), this study investigated the delivery of aerosol under extreme conditions, using a scaled-down 35 mm plate Ames bacterial reverse mutagenicity assay. S. typhimurium strains TA98, TA100, TA97, TA104 and E. coli WP2 uvrA pKM101 with or without metabolic activation (S9), were employed. Using a modified Vitrocell VC 10 exposure system 0, 180, 360, 540, 720 or 900 puffs of undiluted e-cigarette aerosol was generated and delivered to bacterial cultures aligned to reported human consumption data. The results demonstrate that no mutagenic activity was observed in any strain under any test condition even when exposed to 900 puffs of undiluted e-cigarette aerosols +/- S9. Positive control responses were observed in all strains +/- S9. Nicotine assessments demonstrated an increased and consistent aerosol delivery, with calculated maximum doses of ∼1 mg/mL delivery of nicotine. These data demonstrate the validity of this unique testing approach and adds further information to the growing weight of evidence that e-cigarettes offer substantially reduced exposure when compared to conventional cigarette smoke. For future in vitro assessments of next generation tobacco and nicotine products, the generation, delivery and testing of undiluted aerosols can now be considered. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Modeling annual extreme temperature using generalized extreme value distribution: A case study in Malaysia

Science.gov (United States)

Hasan, Husna; Salam, Norfatin; Kassim, Suraiya

2013-04-01

Extreme temperature of several stations in Malaysia is modeled by fitting the annual maximum to the Generalized Extreme Value (GEV) distribution. The Augmented Dickey Fuller (ADF) and Phillips Perron (PP) tests are used to detect stochastic trends among the stations. The Mann-Kendall (MK) test suggests a non-stationary model. Three models are considered for stations with trend and the Likelihood Ratio test is used to determine the best-fitting model. The results show that Subang and Bayan Lepas stations favour a model which is linear for the location parameters while Kota Kinabalu and Sibu stations are suitable with a model in the logarithm of the scale parameters. The return level is the level of events (maximum temperature) which is expected to be exceeded once, on average, in a given number of years, is obtained.

Space Launch System Base Heating Test: Environments and Base Flow Physics

Science.gov (United States)

Mehta, Manish; Knox, Kyle S.; Seaford, C. Mark; Dufrene, Aaron T.

2016-01-01

The NASA Space Launch System (SLS) vehicle is composed of four RS-25 liquid oxygen- hydrogen rocket engines in the core-stage and two 5-segment solid rocket boosters and as a result six hot supersonic plumes interact within the aft section of the vehicle during ight. Due to the complex nature of rocket plume-induced ows within the launch vehicle base during ascent and a new vehicle con guration, sub-scale wind tunnel testing is required to reduce SLS base convective environment uncertainty and design risk levels. This hot- re test program was conducted at the CUBRC Large Energy National Shock (LENS) II short-duration test facility to simulate ight from altitudes of 50 kft to 210 kft. The test program is a challenging and innovative e ort that has not been attempted in 40+ years for a NASA vehicle. This presentation discusses the various trends of base convective heat ux and pressure as a function of altitude at various locations within the core-stage and booster base regions of the two-percent SLS wind tunnel model. In-depth understanding of the base ow physics is presented using the test data, infrared high-speed imaging and theory. The normalized test design environments are compared to various NASA semi- empirical numerical models to determine exceedance and conservatism of the ight scaled test-derived base design environments. Brief discussion of thermal impact to the launch vehicle base components is also presented.

CD-Based Microfluidics for Primary Care in Extreme Point-of-Care Settings

Directory of Open Access Journals (Sweden)

Suzanne Smith

2016-01-01

Full Text Available We review the utility of centrifugal microfluidic technologies applied to point-of-care diagnosis in extremely under-resourced environments. The various challenges faced in these settings are showcased, using areas in India and Africa as examples. Measures for the ability of integrated devices to effectively address point-of-care challenges are highlighted, and centrifugal, often termed CD-based microfluidic technologies, technologies are presented as a promising platform to address these challenges. We describe the advantages of centrifugal liquid handling, as well as the ability of a standard CD player to perform a number of common laboratory tests, fulfilling the role of an integrated lab-on-a-CD. Innovative centrifugal approaches for point-of-care in extremely resource-poor settings are highlighted, including sensing and detection strategies, smart power sources and biomimetic inspiration for environmental control. The evolution of centrifugal microfluidics, along with examples of commercial and advanced prototype centrifugal microfluidic systems, is presented, illustrating the success of deployment at the point-of-care. A close fit of emerging centrifugal systems to address a critical panel of tests for under-resourced clinic settings, formulated by medical experts, is demonstrated. This emphasizes the potential of centrifugal microfluidic technologies to be applied effectively to extremely challenging point-of-care scenarios and in playing a role in improving primary care in resource-limited settings across the developing world.

Reducing test-data volume and test-power simultaneously in LFSR reseeding-based compression environment

Energy Technology Data Exchange (ETDEWEB)

Wang Weizheng; Kuang Jishun; You Zhiqiang; Liu Peng, E-mail: jshkuang@163.com [College of Information Science and Engineering, Hunan University, Changsha 410082 (China)

2011-07-15

This paper presents a new test scheme based on scan block encoding in a linear feedback shift register (LFSR) reseeding-based compression environment. Meanwhile, our paper also introduces a novel algorithm of scan-block clustering. The main contribution of this paper is a flexible test-application framework that achieves significant reductions in switching activity during scan shift and the number of specified bits that need to be generated via LFSR reseeding. Thus, it can significantly reduce the test power and test data volume. Experimental results using Mintest test set on the larger ISCAS'89 benchmarks show that the proposed method reduces the switching activity significantly by 72%-94% and provides a best possible test compression of 74%-94% with little hardware overhead. (semiconductor integrated circuits)

Testing Algorithmic Skills in Traditional and Non-Traditional Programming Environments

Science.gov (United States)

Csernoch, Mária; Biró, Piroska; Máth, János; Abari, Kálmán

2015-01-01

The Testing Algorithmic and Application Skills (TAaAS) project was launched in the 2011/2012 academic year to test first year students of Informatics, focusing on their algorithmic skills in traditional and non-traditional programming environments, and on the transference of their knowledge of Informatics from secondary to tertiary education. The…

Genotype-by-Environment Interaction and Testing Environments for Plantain and Banana (Musa spp. L. Breeding in West Africa

Directory of Open Access Journals (Sweden)

Ortiz, R.

1999-01-01

Full Text Available With reduced budgets allocated for international agricultural research, site rationalisation had become an important issue to consider when carrying out multilocational testing of promising selections. The aim of this paper was to determine the importance of the genotype-by-environment interaction in multilocational trials of plantains and bananas (Musa spp. L. in selected sites of West Africa comprising the humid forest and the forest-savanna transition zones. A sample of plantain-banana hybrids, plantain landraces, exotic banana cultivars and diploid parental banana accessions were evaluated in three locations : Mbalmayo and Onne (humid forest and Ibadan (forest-savanna transition. The experimental results of our research suggested that multilocational testing is more profitable than single site evaluation over several years in the Musa breeding station. Furthermore, based on correlated responses across environments for yield potential, we suggest that one of the selection sites in the humid forest (i. e., Mbalmayo be dropped since selections in one site (Onne may be well adapted to the other location in the same agroecozone. Conversely, the relatively poor performance of most genotypes in dry environments (e. g. Ibadan reinforces the importance of early testing across a wide range of environments. In this way selections with broad or specific adaptation may be identified for further release to targeted farmers.

Design of a Realistic Test Simulator For a Built-In Self Test Environment

Directory of Open Access Journals (Sweden)

A. Ahmad

2010-12-01

Full Text Available This paper presents a realistic test approach suitable to Design For Testability (DFT and Built- In Self Test (BIST environments. The approach is culminated in the form of a test simulator which is capable of providing a required goal of test for the System Under Test (SUT. The simulator uses the approach of fault diagnostics with fault grading procedure to provide the tests. The tool is developed on a common PC platform and hence no special software is required. Thereby, it is a low cost tool and hence economical. The tool is very much suitable for determining realistic test sequences for a targeted goal of testing for any SUT. The developed tool incorporates a flexible Graphical User Interface (GUI procedure and can be operated without any special programming skill. The tool is debugged and tested with the results of many bench mark circuits. Further, this developed tool can be utilized for educational purposes for many courses such as fault-tolerant computing, fault diagnosis, digital electronics, and safe - reliable - testable digital logic designs.

Modular SiGe 130 nm Cell Library for Extreme Environments, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — NASA space missions utilizing application-specific integrated circuits (ASICs) under extreme conditions have a critical need for high performance analog cell...

Space Suit Portable Life Support System (PLSS) 2.0 Unmanned Vacuum Environment Testing

Science.gov (United States)

Watts, Carly; Vogel, Matthew

2016-01-01

For the first time in more than 30 years, an advanced space suit Portable Life Support System (PLSS) design was operated inside a vacuum chamber representative of the flight operating environment. The test article, PLSS 2.0, was the second system-level integrated prototype of the advanced PLSS design, following the PLSS 1.0 Breadboard that was developed and tested throughout 2011. Whereas PLSS 1.0 included five technology development components with the balance the system simulated using commercial-off-the-shelf items, PLSS 2.0 featured first generation or later prototypes for all components less instrumentation, tubing and fittings. Developed throughout 2012, PLSS 2.0 was the first attempt to package the system into a flight-like representative volume. PLSS 2.0 testing included an extensive functional evaluation known as Pre-Installation Acceptance (PIA) testing, Human-in-the-Loop testing in which the PLSS 2.0 prototype was integrated via umbilicals to a manned prototype space suit for 19 two-hour simulated EVAs, and unmanned vacuum environment testing. Unmanned vacuum environment testing took place from 1/9/15-7/9/15 with PLSS 2.0 located inside a vacuum chamber. Test sequences included performance mapping of several components, carbon dioxide removal evaluations at simulated intravehicular activity (IVA) conditions, a regulator pressure schedule assessment, and culminated with 25 simulated extravehicular activities (EVAs). During the unmanned vacuum environment test series, PLSS 2.0 accumulated 378 hours of integrated testing including 291 hours of operation in a vacuum environment and 199 hours of simulated EVA time. The PLSS prototype performed nominally throughout the test series, with two notable exceptions including a pump failure and a Spacesuit Water Membrane Evaporator (SWME) leak, for which post-test failure investigations were performed. In addition to generating an extensive database of PLSS 2.0 performance data, achievements included requirements and

Meeting the challenge of extremely corrosive service: A primer on clad oilfield equipment

International Nuclear Information System (INIS)

Pendley, M.R.

1993-01-01

Extremely corrosive environments, such as those often encountered in deep, hot, sour oil and gas wells, are usually characterized by the presence of hydrogen sulfide (H 2 S), carbon dioxide (CO 2 ), chlorides, and other corrosive species coupled with high temperatures (> 400 F/204 C) and high pressures (up to 20,000 psi/138 MPa). Most low alloy and stainless steel materials are not suitable for such environments. Extremely corrosive service conditions dictate the use of a corrosion-resistant alloy (CRA) in areas which are exposed to the hostile environment. However, it is often cost-prohibitive to make an entire component out of CRA material. An alternative strategy is to use a low alloy steel for the bulk of the component and clad critical surfaces with a corrosion-resistant material. Clad equipment can provide excellent corrosion resistance in hostile environments at a fraction of the cost of 100% CRA components. This paper will detail the problems posed by extremely corrosive environments and discuss how clad equipment provides a cost-effective solution

Some new fatigue tests in high temperature water and liquid sodium environment

International Nuclear Information System (INIS)

Hattori, Takahiro; Yamauchi, Takayoshi; Kanasaki, Hiroshi; Kondo, Yoshiyuki; Endo, Tadayoshi.

1987-01-01

To evaluate the fatigue strength of structural materials for PWR or FBR plants, fatigue test data must be obtained in an environment of simulated primary and secondary water for PWR or of high temperature liquid sodium for FBR. Generally, such tests make it necessary to prepare expensive facilities, so when large amount of fatigue data are required, it is necessary to rationalize and simplify the fatigue tests while maintaining high accuracy. At the Takasago Research Development Center, efforts to rationalize facilities and maintain accuracy in fatigue tests have been made by developing new test methods and improving conventional techniques. This paper introduces a new method of low cycle fatigue test in high temperature water, techniques for automatic measurement of crack initiation and propagation in high temperature water environment and a multiple type fatigue testing machine for high temperature liquid sodium. (author)

Effect of pH to adsorption behavior of Pu on bentonite in aqueous environment

International Nuclear Information System (INIS)

Wang Xiaoqiang; Tuo Xianguo; Li Pingchuan; Leng Yangchun; Su Jilong; Yueping

2013-01-01

The effects of pH to the adsorption behavior of Pu in GMZ-bentonite, Lingshou Ca-bentonite, Na-bentonite and bleaching earth were tested by static adsorption experiments in aqueous environment. The results show that the adsorption equilibrium time of Pu is four days in GMZ-bentonite and 5-6 days in bleaching earth, Ca-bentonite and Na-bentonite. In aqueous environment, the adsorption capacity of bentonite to Pu increases with pH in water phase, and it is weak in acidic aqueous environment and strong in alkaline aqueous environment extremely. (authors)

Space Environment Testing of Photovoltaic Array Systems at NASA's Marshall Space Flight Center

Science.gov (United States)

Phillips, Brandon S.; Schneider, Todd A.; Vaughn, Jason A.; Wright, Kenneth H., Jr.

2015-01-01

To successfully operate a photovoltaic (PV) array system in space requires planning and testing to account for the effects of the space environment. It is critical to understand space environment interactions not only on the PV components, but also the array substrate materials, wiring harnesses, connectors, and protection circuitry (e.g. blocking diodes). Key elements of the space environment which must be accounted for in a PV system design include: Solar Photon Radiation, Charged Particle Radiation, Plasma, and Thermal Cycling. While solar photon radiation is central to generating power in PV systems, the complete spectrum includes short wavelength ultraviolet components, which photo-ionize materials, as well as long wavelength infrared which heat materials. High energy electron radiation has been demonstrated to significantly reduce the output power of III-V type PV cells; and proton radiation damages material surfaces - often impacting coverglasses and antireflective coatings. Plasma environments influence electrostatic charging of PV array materials, and must be understood to ensure that long duration arcs do not form and potentially destroy PV cells. Thermal cycling impacts all components on a PV array by inducing stresses due to thermal expansion and contraction. Given such demanding environments, and the complexity of structures and materials that form a PV array system, mission success can only be ensured through realistic testing in the laboratory. NASA's Marshall Space Flight Center has developed a broad space environment test capability to allow PV array designers and manufacturers to verify their system's integrity and avoid costly on-orbit failures. The Marshall Space Flight Center test capabilities are available to government, commercial, and university customers. Test solutions are tailored to meet the customer's needs, and can include performance assessments, such as flash testing in the case of PV cells.

Experimental Results of Thin-Film Photovoltaic Cells in a Low Density LEO Plasma Environment: Ground Tests

Science.gov (United States)

Galofaro, Joel T.; Vayner, Boris V.

2006-01-01

Plasma ground testing results, conducted at the Glenn Research Center (GRC) National Plasma Interaction (N-PI) Facility, are presented for a number of thin-film photovoltaic cells. The cells represent a mix of promising new technologies identified by the Air Force Research Laboratory (AFRL) under the CYGNUS Space Science Technology Experiment (SSTE-4) Program. The current ground tests are aimed at characterizing the performance and survivability of thin film technologies in the harsh low earth orbital space environment where they will be flown. Measurements of parasitic current loss, charging/dielectric breakdown of cover-slide coatings and arcing threshold tests are performed for each individual cell. These measurements are followed by a series of experiments designed to test for catastrophic arc failure mechanisms. A special type of power supply, called a solar array simulator (SAS) with adjustable voltage and current limits on the supply s output, is employed to bias two adjacent cells at a predetermined voltage and current. The bias voltage is incrementally ramped up until a sustained arc results. Sustained arcs are precursors to catastrophic arc failure where the arc current rises to a maximum value for long timescales often ranging between 30 to 100 sec times. Normal arcs by comparison, are short lived events with a timescale between 10 to 30 sec. Sustained arcs lead to pyrolization with extreme cell damage and have been shown to cause the loss of entire array strings in solar arrays. The collected data will be used to evaluate the suitability of thin-film photovoltaic technologies for future space operations.

A prospective comparison of pedal ergometry with conventional treadmill testing in the investigation of lower extremity pain.

LENUS (Irish Health Repository)

Manning, B J

2012-02-03

BACKGROUND: Investigation of lower extremity pain is compromised by comorbid disorders that may interfere with conventional testing. AIMS: To compare pedal ergometry with conventional treadmill testing. METHODS: A prospective study was performed where patients presenting with a diagnosis of intermittent claudication were assessed by both methods of testing. RESULTS: Of 78 patients studied with both tests, no exercise-induced ankle pressure changes occurred in 26, two were unable to complete either test despite normal pressure measurements, while 24 had exercise-induced pressure drop detected by both tests. Of patients who completed pedal ergometry, 21 were unable to complete the treadmill test, 14 of whom had negative ergometry, while seven had a pressure drop detected by pedal ergometry. Three had pressure changes with pedal ergometry, but not with treadmill testing and two had pressure changes on the treadmill not reproduced by pedal ergometry. CONCLUSIONS: Pedal ergometer is more sensitive than treadmill testing in detecting arterial insufficiency, as indicated by a 20% or greater fall in ankle pressure, and more suitable in a subgroup of patients unable to tolerate conventional treadmill testing.

Development and Testing of the Church Environment Audit Tool.

Science.gov (United States)

Kaczynski, Andrew T; Jake-Schoffman, Danielle E; Peters, Nathan A; Dunn, Caroline G; Wilcox, Sara; Forthofer, Melinda

2018-05-01

In this paper, we describe development and reliability testing of a novel tool to evaluate the physical environment of faith-based settings pertaining to opportunities for physical activity (PA) and healthy eating (HE). Tool development was a multistage process including a review of similar tools, stakeholder review, expert feedback, and pilot testing. Final tool sections included indoor opportunities for PA, outdoor opportunities for PA, food preparation equipment, kitchen type, food for purchase, beverages for purchase, and media. Two independent audits were completed at 54 churches. Interrater reliability (IRR) was determined with Kappa and percent agreement. Of 218 items, 102 were assessed for IRR and 116 could not be assessed because they were not present at enough churches. Percent agreement for all 102 items was over 80%. For 42 items, the sample was too homogeneous to assess Kappa. Forty-six of the remaining items had Kappas greater than 0.60 (25 items 0.80-1.00; 21 items 0.60-0.79), indicating substantial to almost perfect agreement. The tool proved reliable and efficient for assessing church environments and identifying potential intervention points. Future work can focus on applications within faith-based partnerships to understand how church environments influence diverse health outcomes.

Variability of extreme wet events over Malawi

Directory of Open Access Journals (Sweden)

Libanda Brigadier

2017-01-01

Full Text Available Adverse effects of extreme wet events are well documented by several studies around the world. These effects are exacerbated in developing countries like Malawi that have insufficient risk reduction strategies and capacity to cope with extreme wet weather. Ardent monitoring of the variability of extreme wet events over Malawi is therefore imperative. The use of the Expert Team on Climate Change Detection and Indices (ETCCDI has been recommended by many studies as an effective way of quantifying extreme wet events. In this study, ETCCDI indices were used to examine the number of heavy, very heavy, and extremely heavy rainfall days; daily and five-day maximum rainfall; very wet and extremely wet days; annual wet days and simple daily intensity. The Standard Normal Homogeneity Test (SNHT was employed at 5% significance level before any statistical test was done. Trend analysis was done using the nonparametric Mann-Kendall statistical test. All stations were found to be homogeneous apart from Mimosa. Trend results show high temporal and spatial variability with the only significant results being: increase in daily maximum rainfall (Rx1day over Karonga and Bvumbwe, increase in five-day maximum rainfall (Rx5day over Bvumbwe. Mzimba and Chileka recorded a significant decrease in very wet days (R95p while a significant increase was observed over Thyolo. Chileka was the only station which observed a significant trend (decrease in extremely wet rainfall (R99p. Mzimba was the only station that reported a significant trend (decrease in annual wet-day rainfall total (PRCPTOT and Thyolo was the only station that reported a significant trend (increase in simple daily intensity (SDII. Furthermore, the findings of this study revealed that, during wet years, Malawi is characterised by an anomalous convergence of strong south-easterly and north-easterly winds. This convergence is the main rain bringing mechanism to Malawi.

When we test, do we stress? Impact of the testing environment on cortisol secretion and memory performance in older adults.

Science.gov (United States)

Sindi, Shireen; Fiocco, Alexandra J; Juster, Robert-Paul; Pruessner, Jens; Lupien, Sonia J

2013-08-01

The majority of studies find that older adults have worse memory performance than young adults. However, contextual features in the testing environment may be perceived as stressful by older adults, increasing their stress hormone levels. Given the evidence that older adults are highly sensitive to the effects of stress hormones (cortisol) on memory performance, it is postulated that a stressful testing environment in older adults can lead to an acute stress response and to memory impairments. The current study compared salivary cortisol levels and memory performance in young and older adults tested in environments manipulated to be stressful (unfavourable condition) or not stressful (favourable condition) for each age group. 28 young adults and 32 older adults were tested in two testing conditions: (1) a condition favouring young adults (constructed to be less stressful for young adults), and (2) a condition favouring older adults (constructed to be less stressful for older adults). The main outcome measure was salivary cortisol levels. Additionally, immediate and delayed memory performances were assessed during each condition. In older adults only, we found significantly high cortisol levels and low memory performance in the condition favouring young adults. In contrast, cortisol levels were lower and memory performance was better when older adults were tested in conditions favouring them. There was no effect of testing condition in young adults. The results demonstrate that older adults' memory performance is highly sensitive to the testing environment. These findings have important implications for both research and clinical settings in which older adults are tested for memory performance. Copyright © 2012 Elsevier Ltd. All rights reserved.

USB HW/SW Co-Simulation Environment with Custom Test Tool Integration

Directory of Open Access Journals (Sweden)

Grigor Y. Zargaryan

2014-06-01

Full Text Available This paper describes a new verification environment for USB 2.0 controller. New methodology is presented, where a co-simulation environment is used as one of the starting points for the embedded hardware/software development and as an accelerator of the overall design process. The verification environment is based on the device emulation/virtualization technique, using USB controller’s real register transfer level (RTL instead of models. This approach is functionally very close to the corresponding real-world devices and allows wider opportunities for hardware debugging. The new software utilities for USB host and device functionality testing are also presented. This tool allows generating custom tests by including various transfer types and modifying parameters such as data payload, interval, number of pipes, etc. It can be used for both hardware (HW and software (SW limitations characterization, as well as debugging.

The Engineering for Climate Extremes Partnership

Science.gov (United States)

Holland, G. J.; Tye, M. R.

2014-12-01

Hurricane Sandy and the recent floods in Thailand have demonstrated not only how sensitive the urban environment is to the impact of severe weather, but also the associated global reach of the ramifications. These, together with other growing extreme weather impacts and the increasing interdependence of global commercial activities point towards a growing vulnerability to weather and climate extremes. The Engineering for Climate Extremes Partnership brings academia, industry and government together with the goals encouraging joint activities aimed at developing new, robust, and well-communicated responses to this increasing vulnerability. Integral to the approach is the concept of 'graceful failure' in which flexible designs are adopted that protect against failure by combining engineering or network strengths with a plan for efficient and rapid recovery if and when they fail. Such an approach enables optimal planning for both known future scenarios and their assessed uncertainty.

Performance testing of waste forms in a tuff environment

International Nuclear Information System (INIS)

Oversby, V.M.

1983-11-01

This paper describes experimental work conducted to establish the chemical composition of water which will have reacted with Topopah Spring Member tuff prior to contact with waste packages. The experimental program to determine the behavior of spent fuel and borosilicate glass in the presence of this water is then described. Preliminary results of experiments using spent fuel segments with defects in the Zircaloy cladding are presented. Some results from parametric testing of a borosilicate glass with tuff and 304L stainless steel are also discussed. Experiments conducted using Topopah Spring tuff and J-13 well water have been conducted to provide an estimate of the post-emplacement environment for waste packages in a repository at Yucca Mountain. The results show that emplacement of waste packages should cause only small changes in the water chemistry and rock mineralogy. The changes in environment should not have any detrimental effects on the performance of metal barriers or waste forms. The NNWSI waste form testing program has provided preliminary results related to the release rate of radionuclides from the waste package. Those results indicate that release rates from both spent fuel and borosilicate glass should be below 1 part in 10 5 per year. Future testing will be directed toward making release rate testing more closely relevant to site specific conditions. 17 references, 7 figures

Assessing The Representative And Discriminative Ability Of Test Environments For Rice Breeding In Malaysia Using GGE Biplot

Directory of Open Access Journals (Sweden)

Yusuff Oladosu

2017-11-01

Full Text Available Identification of outstanding rice genotype for target environments is complicated by genotype environment interactions. Using genotype main effect plus genotype by environment interaction GGE Biplot software fifteen rice genotypes were evaluated at five locations representing the major rice producing areas in peninsula Malaysia in two cropping seasons to i identify ideal test environment for selecting superior rice genotype and ii identify discriminative and representative ability of test locations. Genotypes locations years and genotypes by environment interaction effect revealed high significant difference P 0.01 for number of tillers per hill grains per panicle grain weight per hill and yield per hectare. Grain yield per hectare had a non-repeatable crossover pattern that formed a complex and single mega-environment. Based on the crossover pattern a set of cultivars were selected for the whole region on the merit of mean performance and their stability analysis. The tested environments were divided into two mega-environments. An ideal test environment that measures the discriminative and representative ability of test location reveal that environment Sekinchan SC is the best environment while Kedah KD and Penang PN can also be considered as favorable environment whereas Serdang SS and Tanjung Karang TK were the poorest locations for selecting genotypes adapted to the whole region. This study serves a reference for genotypes evaluation as well as identification of test locations for rice breeding in Malaysia.

TEST-RETEST RELIABILITY OF THE CLOSED KINETIC CHAIN UPPER EXTREMITY STABILITY TEST (CKCUEST) IN ADOLESCENTS: RELIABILITY OF CKCUEST IN ADOLESCENTS.

Science.gov (United States)

de Oliveira, Valéria M A; Pitangui, Ana C R; Nascimento, Vinícius Y S; da Silva, Hítalo A; Dos Passos, Muana H P; de Araújo, Rodrigo C

2017-02-01

The Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST) has been proposed as an option to assess upper limb function and stability; however, there are few studies that support the use of this test in adolescents. The purpose of the present study was to investigate the intersession reliability and agreement of three CKCUEST scores in adolescents and establish clinimetric values for this test. Test-retest reliability. Twenty-five healthy adolescents of both sexes were evaluated. The subjects performed two CKCUEST with an interval of one week between the tests. An intraclass correlation coefficient (ICC 3,3 ) two-way mixed model with a 95% interval of confidence was utilized to determine intersession reliability. A Bland-Altman graph was plotted to analyze the agreement between assessments. The presence of systematic error was evaluated by a one-sample t test. The difference between the evaluation and reevaluation was observed using a paired-sample t test. The level of significance was set at 0.05. Standard error of measurements and minimum detectable changes were calculated. The intersession reliability of the average touches score, normalized score, and power score were 0.68, 0.68 and 0.87, the standard error of measurement were 2.17, 1.35 and 6.49, and the minimal detectable change was 6.01, 3.74 and 17.98, respectively. The presence of systematic error (p test with moderate to excellent reliability when used with adolescents. The CKCUEST is a measurement with moderate to excellent reliability for adolescents. 2b.

Somersault of Paramecium in extremely confined environments

Science.gov (United States)

Jana, Saikat; Eddins, Aja; Spoon, Corrie; Jung, Sunghwan

2015-08-01

We investigate various swimming modes of Paramecium in geometric confinements and a non-swimming self-bending behavior like a somersault, which is quite different from the previously reported behaviors. We observe that Paramecia execute directional sinusoidal trajectories in thick fluid films, whereas Paramecia meander around a localized region and execute frequent turns due to collisions with adjacent walls in thin fluid films. When Paramecia are further constrained in rectangular channels narrower than the length of the cell body, a fraction of meandering Paramecia buckle their body by pushing on the channel walls. The bucking (self-bending) of the cell body allows the Paramecium to reorient its anterior end and explore a completely new direction in extremely confined spaces. Using force deflection method, we quantify the Young’s modulus of the cell and estimate the swimming and bending powers exerted by Paramecium. The analysis shows that Paramecia can utilize a fraction of its swimming power to execute the self-bending maneuver within the confined channel and no extra power may be required for this new kind of self-bending behavior. This investigation sheds light on how micro-organisms can use the flexibility of the body to actively navigate within confined spaces.

Sensor integration and testing in an airborne environment

Science.gov (United States)

Ricks, Timothy P.; Streling, Julie T.; Williams, Kirk W.

2005-11-01

The U.S. Army Redstone Technical Test Center (RTTC) has been supporting captive flight testing of missile sensors and seekers since the 1980's. Successful integration and test of sensors in an airborne environment requires attention to a broad range of disciplines. Data collection requirements drive instrumentation and flight profile configurations, which along with cost and airframe performance factors influence the choice of test aircraft. Installation methods used for instrumentation must take into consideration environmental and airworthiness factors. In addition, integration of test equipment into the aircraft will require an airworthiness release; procedures vary between the government for military aircraft, and the Federal Aviation Administration (FAA) for the use of private, commercial, or experimental aircraft. Sensor mounting methods will depend on the type of sensor being used, both for sensor performance and crew safety concerns. Pilots will require navigation input to permit the execution of accurate and repeatable flight profiles. Some tests may require profiles that are not supported by standard navigation displays, requiring the use of custom hardware/software. Test locations must also be considered in their effect on successful data collection. Restricted airspace may also be required, depending on sensor emissions and flight profiles.

Resistance of Bacillus Endospores to Extreme Terrestrial and Extraterrestrial Environments

Science.gov (United States)

Nicholson, Wayne L.; Munakata, Nobuo; Horneck, Gerda; Melosh, Henry J.; Setlow, Peter

2000-01-01

Endospores of Bacillus spp., especially Bacillus subtilis, have served as experimental models for exploring the molecular mechanisms underlying the incredible longevity of spores and their resistance to environmental insults. In this review we summarize the molecular laboratory model of spore resistance mechanisms and attempt to use the model as a basis for exploration of the resistance of spores to environmental extremes both on Earth and during postulated interplanetary transfer through space as a result of natural impact processes. PMID:10974126

The Rapid Integration and Test Environment - A Process for Achieving Software Test Acceptance

OpenAIRE

Jack, Rick

2010-01-01

Proceedings Paper (for Acquisition Research Program) Approved for public release; distribution unlimited. The Rapid Integration and Test Environment (RITE) initiative, implemented by the Program Executive Office, Command, Control, Communications, Computers and Intelligence, Command and Control Program Office (PMW-150), was born of necessity. Existing processes for requirements definition and management, as well as those for software development, did not consistently deliver high-qualit...

Lower extremity finite element model for crash simulation

Energy Technology Data Exchange (ETDEWEB)

Schauer, D.A.; Perfect, S.A.

1996-03-01

A lower extremity model has been developed to study occupant injury mechanisms of the major bones and ligamentous soft tissues resulting from vehicle collisions. The model is based on anatomically correct digitized bone surfaces of the pelvis, femur, patella and the tibia. Many muscles, tendons and ligaments were incrementally added to the basic bone model. We have simulated two types of occupant loading that occur in a crash environment using a non-linear large deformation finite element code. The modeling approach assumed that the leg was passive during its response to the excitation, that is, no active muscular contraction and therefore no active change in limb stiffness. The approach recognized that the most important contributions of the muscles to the lower extremity response are their ability to define and modify the impedance of the limb. When nonlinear material behavior in a component of the leg model was deemed important to response, a nonlinear constitutive model was incorporated. The accuracy of these assumptions can be verified only through a review of analysis results and careful comparison with test data. As currently defined, the model meets the objective for which it was created. Much work remains to be done, both from modeling and analysis perspectives, before the model can be considered complete. The model implements a modeling philosophy that can accurately capture both kinematic and kinetic response of the lower limb. We have demonstrated that the lower extremity model is a valuable tool for understanding the injury processes and mechanisms. We are now in a position to extend the computer simulation to investigate the clinical fracture patterns observed in actual crashes. Additional experience with this model will enable us to make a statement on what measures are needed to significantly reduce lower extremity injuries in vehicle crashes. 6 refs.

Beyond Comfort in Built Environments

NARCIS (Netherlands)

Bazley, C.M.

2015-01-01

Every person on the planet lives a significant portion of his or her life in a built indoor environment. Ideally, the built environment serves as protection from the extremes of the outdoor environment and is preferably comfortable. The first ‘built environment’ was a painted cave. The cave served

Mars Science Laboratory Rover System Thermal Test

Science.gov (United States)

Novak, Keith S.; Kempenaar, Joshua E.; Liu, Yuanming; Bhandari, Pradeep; Dudik, Brenda A.

2012-01-01

On November 26, 2011, NASA launched a large (900 kg) rover as part of the Mars Science Laboratory (MSL) mission to Mars. The MSL rover is scheduled to land on Mars on August 5, 2012. Prior to launch, the Rover was successfully operated in simulated mission extreme environments during a 16-day long Rover System Thermal Test (STT). This paper describes the MSL Rover STT, test planning, test execution, test results, thermal model correlation and flight predictions. The rover was tested in the JPL 25-Foot Diameter Space Simulator Facility at the Jet Propulsion Laboratory (JPL). The Rover operated in simulated Cruise (vacuum) and Mars Surface environments (8 Torr nitrogen gas) with mission extreme hot and cold boundary conditions. A Xenon lamp solar simulator was used to impose simulated solar loads on the rover during a bounding hot case and during a simulated Mars diurnal test case. All thermal hardware was exercised and performed nominally. The Rover Heat Rejection System, a liquid-phase fluid loop used to transport heat in and out of the electronics boxes inside the rover chassis, performed better than predicted. Steady state and transient data were collected to allow correlation of analytical thermal models. These thermal models were subsequently used to predict rover thermal performance for the MSL Gale Crater landing site. Models predict that critical hardware temperatures will be maintained within allowable flight limits over the entire 669 Sol surface mission.

Interoperable Solution for Test Execution in Various I&T Environments

Science.gov (United States)

Lee, Young H.; Bareh, Magdy S.

2006-01-01

When there is spacecraft collaboration between several industry partners, there is an inherent difference in integration and test (I&T) methodologies, which creates a challenge for verifying flight systems during the development phase. To converge the differing I&T methodologies, considerations were required for multiple project areas such as Flight System Testbed (FST), Assembly, Test, and Launch Operations (ATLO), and Spacecraft Simulator environments. This paper details the challenges and approaches of the JPL's effort in engineering a solution to testing the flight system with the Mission Operations Ground System while maintaining the comparability with testing methods of the industry partners.

High Temperature Testing with Sapphire Fiber White-Light Michelson Interferometers

Science.gov (United States)

Barnes, A.; Pedrazzani, J.; May, R.; Murphy, K.; Tran, T.; Coate, J.

1996-01-01

In the design of new aerospace materials, developmental testing is conducted to characterize the behavior of the material under severe environmental conditions of high stress, temperature, and vibration. But to test these materials under extreme conditions requires sensors that can perform in harsh environments. Current sensors can only monitor high temperature test samples using long throw instrumentation, but this is inherently less accurate than a surface mounted sensor, and provides no means for fabrication process monitoring. A promising alternative is the use of sapphire optical fiber sensors. Sapphire is an incredibly rugged material, being extremely hard (9 mhos), chemically inert, and having a melting temperature (over 2000 C). Additionally, there is a extensive background of optical fiber sensors upon which to draw for sapphire sensor configurations.

Mobile genetic elements, a key to microbial adaptation in extreme environments

Science.gov (United States)

van Houdt, Rob; Mijnendonckx, Kristel; Provoost, Ann; Monsieurs, Pieter; Mergeay, Max; Leys, Natalie

hydrogenotrophy. Five transposons were identified in CH34. Two mercury transposons Tn4378 and Tn4380, respectively located on pMOL28 and pMOL30, were previously described. In addition, 3 novel transposons were identified. The large Tn6048 transposon contained 8 genes highly induced by zinc and lead. Transposon Tn6049 was found in twelve copies in the genome of strain CH34 and is seem-ingly often associated with genomic islands. Finally, Tn6050 was observed twice in the second chromosome with accessory genes not classically associated with transposons, namely a sulfate permease, a universal stress protein (UspA) and a DksA-like DnaK suppressor protein. The role of these genes is unclear but a functional association could be assumed. Finally, a set of 21 IS elements was found, counting in total for 57 copies dispersed over the genome. The number of copies ranged from 1 to 9 (IS1088 ) and 10 (ISRme3 ). The 21 IS elements could be divided into 10 different families. The elements ISRme5 and IS1071 were putatively involved in the recruitment of the genes for hydrogenotrophy and CO2 fixation, with mutants unable to grow on H2 and CO2 appeared to have lost these genes by IS1071 -mediated excision. These data clearly showed that the C. metallidurans CH34 model bacterium and some of it's Cupriavidus and Ralstonia relatives carry a multitude of tools that allowed them to genetically adapt to polluted and extreme soil environments, and that are a key in their success to adapt to the new anthropogenic spacecraft environments. Furthermore, these tools could be exploited to assess and measure genetic effects of spaceflight conditions. Acknowledgements This work was supported by the European Space Agency (ESA-PRODEX) and the Belgian Science Policy (Belspo) through the MISSEX and COMICS projects.

Opportunities and constraints for improved water resources management under increasing hydrological extremes

Science.gov (United States)

Wada, Y.

2017-12-01

Increased occurrence of extreme climate events is one of the most damaging consequences of global climate change today and in the future. Estimating the impacts of such extreme events on global and regional water resources is therefore crucial for quantifying increasing risks from climate change. The quest for water security has been a struggle throughout human history. Only in recent years has the scale of this quest moved beyond the local, to the national and regional scales and to the planet itself. Absent or unreliable water supply, sanitation and irrigation services, unmitigated floods and droughts, and degraded water environments severely impact half of the planet's population. The scale and complexity of the water challenges faced by society, particularly but not only in the world's poorest regions, are now recognized, as is the imperative of overcoming these challenges for a stable and equitable world. IIASA's Water Futures and Solutions Initiative (WFAS) is an unprecedented inter-disciplinary scientific initiative to identify robust and adaptive portfolios of optional solutions across different economic sectors, including agriculture, energy and industry, and to test these solution-portfolios with multi-model ensembles of hydrologic and sector models to obtain a clearer picture of the trade-offs, risks, and opportunities. The results of WFaS scenarios and models provide a basis for long-term strategic planning of water resource development under changing environments and increasing climate extremes. And given the complexity of the water system, WFaS uniquely provides policy makers with optional sets of solutions that work together and that can be easily adapted as circumstances change in the future. As WFaS progresses, it will establish a network involving information exchange, mutual learning and horizontal cooperation across teams of researchers, public and private decision makers and practitioners exploring solutions at regional, national and local

Can MOND type hypotheses be tested in a free fall laboratory environment?

Science.gov (United States)

Das, Saurya; Patitsas, S. N.

2013-05-01

The extremely small accelerations of objects required for the onset of modified Newtonian dynamics, or modified Newtonian dynamics (MOND), makes testing the hypothesis in conventional terrestrial laboratories virtually impossible. This is due to the large background acceleration of Earth, which is transmitted to the acceleration of test objects within an apparatus. We show, however, that it may be possible to test MOND-type hypotheses with experiments using a conventional apparatus capable of tracking very small accelerations of its components but performed in locally inertial frames such as artificial satellites and other freely falling laboratories. For example, experiments involving an optical interferometer or a torsion balance in these laboratories would show nonlinear dynamics and displacement amplitudes larger than expected. These experiments may also be able to test potential violations of the strong equivalence principle by MOND and to distinguish between its two possible interpretations (modified inertia and modified gravity).

14 CFR Appendix J to Part 23 - HIRF Environments and Equipment HIRF Test Levels

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false HIRF Environments and Equipment HIRF Test Levels J Appendix J to Part 23 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF.... 23, App. J Appendix J to Part 23—HIRF Environments and Equipment HIRF Test Levels This appendix...

EPS-LASSO: Test for High-Dimensional Regression Under Extreme Phenotype Sampling of Continuous Traits.

Science.gov (United States)

Xu, Chao; Fang, Jian; Shen, Hui; Wang, Yu-Ping; Deng, Hong-Wen

2018-01-25

Extreme phenotype sampling (EPS) is a broadly-used design to identify candidate genetic factors contributing to the variation of quantitative traits. By enriching the signals in extreme phenotypic samples, EPS can boost the association power compared to random sampling. Most existing statistical methods for EPS examine the genetic factors individually, despite many quantitative traits have multiple genetic factors underlying their variation. It is desirable to model the joint effects of genetic factors, which may increase the power and identify novel quantitative trait loci under EPS. The joint analysis of genetic data in high-dimensional situations requires specialized techniques, e.g., the least absolute shrinkage and selection operator (LASSO). Although there are extensive research and application related to LASSO, the statistical inference and testing for the sparse model under EPS remain unknown. We propose a novel sparse model (EPS-LASSO) with hypothesis test for high-dimensional regression under EPS based on a decorrelated score function. The comprehensive simulation shows EPS-LASSO outperforms existing methods with stable type I error and FDR control. EPS-LASSO can provide a consistent power for both low- and high-dimensional situations compared with the other methods dealing with high-dimensional situations. The power of EPS-LASSO is close to other low-dimensional methods when the causal effect sizes are small and is superior when the effects are large. Applying EPS-LASSO to a transcriptome-wide gene expression study for obesity reveals 10 significant body mass index associated genes. Our results indicate that EPS-LASSO is an effective method for EPS data analysis, which can account for correlated predictors. The source code is available at https://github.com/xu1912/EPSLASSO. hdeng2@tulane.edu. Supplementary data are available at Bioinformatics online. © The Author (2018). Published by Oxford University Press. All rights reserved. For Permissions, please

Spatial Layout of Multi-Environment Test Sites: A Case Study of Maize in Jilin Province

Directory of Open Access Journals (Sweden)

Zuliang Zhao

2018-05-01

Full Text Available Variety regional tests based on multiple environments play a critical role in understanding the high yield and adaptability of new crop varieties. However, the current approach mainly depends on experience from breeding experts and is difficulty to promote because of inconsistency between testing and actual situation. We propose a spatial layout method based on the existing systematic regional test network. First, the method of spatial clustering was used to cluster the planting environment. Then, we used spatial stratified sampling to determine the minimum number of test sites in each type of environment. Finally, combined with the factors such as the convenience of transportation and the planting area, we used spatial balance sampling to generate the layout of multi-environment test sites. We present a case study for maize in Jilin Province and show the utility of the method with an accuracy of about 94.5%. The experimental results showed that 66.7% of sites are located in the same county and the unbalanced layout of original sites is improved. Furthermore, we conclude that the set of operational technical ideas for carrying out the layout of multi-environment test sites based on crop varieties in this paper can be applied to future research.

Extreme hypoxia tolerance of naked mole-rat brain.

Science.gov (United States)

Larson, John; Park, Thomas J

2009-12-09

Mammalian brains have extremely high levels of aerobic metabolism and typically suffer irreversible damage after brief periods of oxygen deprivation such as occur during stroke or cardiac arrest. Here we report that brain tissue from naked mole-rats, rodents that live in a chronically low-oxygen environment, is remarkably resistant to hypoxia: naked mole-rat neurons maintain synaptic transmission much longer than mouse neurons and can recover from periods of anoxia exceeding 30 min. We suggest that brain tolerance to hypoxia may result from slowed or arrested brain development in these extremely long-lived animals.

Reliability of the Quality of Upper Extremity Skills Test for Children with Cerebral Palsy Aged 2 to 12 Years

Science.gov (United States)

Thorley, Megan; Lannin, Natasha; Cusick, Anne; Novak, Iona; Boyd, Roslyn

2012-01-01

Aim: To investigate reliability of the Quality of Upper Extremity Skills Test (QUEST) scores for children with cerebral palsy (CP) aged 2-12 years. Method: Thirty-one QUESTs from 24 children with CP were rated once by two raters and twice by one rater. Internal consistency of total scores, inter- and intra-rater reliability findings for total,…

PREDICTION OF THE EXTREMAL SHAPE FACTOR OF SPHEROIDAL PARTICLES

Directory of Open Access Journals (Sweden)

Daniel Hlubinka

2011-05-01

Full Text Available In the stereological unfolding problem for spheroidal particles the extremal shape factor is predicted. The theory of extreme values has been used to show that extremes of the planar shape factor of particle sections tend to the same limit distribution as extremes of the original shape factor for both the conditional and marginal distribution. Attention is then paid to the extreme shape factor conditioned by the particle size. Normalizing constants are evaluated for a parametric model and the numerical procedure is tested on real data from metallography.

Sample Return Systems for Extreme Environments

Data.gov (United States)

National Aeronautics and Space Administration — The proposed work seeks to design, develop and test a hard impact penetrator/sampler that can withstand the hard impact and enable the sample to be returned to...

Generating realistic environments for cyber operations development, testing, and training

Science.gov (United States)

Berk, Vincent H.; Gregorio-de Souza, Ian; Murphy, John P.

2012-06-01

Training eective cyber operatives requires realistic network environments that incorporate the structural and social complexities representative of the real world. Network trac generators facilitate repeatable experiments for the development, training and testing of cyber operations. However, current network trac generators, ranging from simple load testers to complex frameworks, fail to capture the realism inherent in actual environments. In order to improve the realism of network trac generated by these systems, it is necessary to quantitatively measure the level of realism in generated trac with respect to the environment being mimicked. We categorize realism measures into statistical, content, and behavioral measurements, and propose various metrics that can be applied at each level to indicate how eectively the generated trac mimics the real world.

Use of gas-phase ethanol to mitigate extreme UV/water oxidation of extreme UV optics

Science.gov (United States)

Klebanoff, L. E.; Malinowski, M. E.; Clift, W. M.; Steinhaus, C.; Grunow, P.

2004-03-01

A technique is described that uses a gas-phase species to mitigate the oxidation of a Mo/Si multilayer optic caused by either extreme UV (EUV) or electron-induced dissociation of adsorbed water vapor. It is found that introduction of ethanol (EtOH) into a water-rich gas-phase environment inhibits oxidation of the outermost Si layer of the Mo/Si EUV reflective coating. Auger electron spectroscopy, sputter Auger depth profiling, EUV reflectivity, and photocurrent measurements are presented that reveal the EUV/water- and electron/water-derived optic oxidation can be suppressed at the water partial pressures used in the tests (~2×10-7-2×10-5 Torr). The ethanol appears to function differently in two time regimes. At early times, ethanol decomposes on the optic surface, providing reactive carbon atoms that scavenge reactive oxygen atoms before they can oxidize the outermost Si layer. At later times, the reactive carbon atoms form a thin (~5 Å), possibly self-limited, graphitic layer that inhibits water adsorption on the optic surface. .

Exascale Co-Design Center for Materials in Extreme Environments (ExMatEx) Annual Report - Year 2

Energy Technology Data Exchange (ETDEWEB)

Germann, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Richards, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McPherson, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Belak, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2013-11-25

All activities of the Exascale Co-design Center for Materials in Extreme Environments (Ex- MatEx) are focused on the two ultimate goals of the project: (1) demonstrating and delivering a prototype scale-bridging materials science application based upon adaptive physics refinement, and (2) identifying the requirements for the exascale ecosystem that are necessary to perform computational materials science simulations (both single- and multi-scale). During the first year of ExMatEx, our focus was on establishing how we do computational materials science, by developing an initial suite of flexible proxy applications. These “proxy apps” are the primary vehicle for the co-design process, involving assessments and tradeoff evaluations both within the ExMatEx team, and with the entire exascale ecosystem. These interactions have formed the basis of our second year activities. The set of artifacts from these co-design interactions are the lessons learned, that are used to re-express the applications and algorithms within the context of emerging architectures, programming models, and runtime systems.

Lichensphere: a protected natural microhabitat of the non-lichenised fungal communities living in extreme environments of Antarctica.

Science.gov (United States)

Santiago, Iara F; Soares, Marco Aurélio; Rosa, Carlos A; Rosa, Luiz H

2015-11-01

We surveyed the diversity, distribution and ecology of non-lichenised fungal communities associated with the Antarctic lichens Usnea antarctica and Usnea aurantiaco-atra across Antarctica. The phylogenetic study of the 438 fungi isolates identified 74 taxa from 21 genera of Ascomycota, Basidiomycota and Zygomycota. The most abundant taxa were Pseudogymnoascus sp., Thelebolus sp., Antarctomyces psychrotrophicus and Cryptococcus victoriae, which are considered endemic and/or highly adapted to Antarctica. Thirty-five fungi may represent new and/or endemic species. The fungal communities displayed high diversity, richness and dominance indices; however, the similarity among the communities was variable. After discovering rich and diverse fungal communities composed of symbionts, decomposers, parasites and endemic and cold-adapted cosmopolitan taxa, we introduced the term "lichensphere". We hypothesised that the lichensphere may represent a protected natural microhabitat with favourable conditions able to help non-lichenised fungi and other Antarctic life forms survive and disperse in the extreme environments of Antarctica.

Spatial extreme value analysis to project extremes of large-scale indicators for severe weather.

Science.gov (United States)

Gilleland, Eric; Brown, Barbara G; Ammann, Caspar M

2013-09-01

Concurrently high values of the maximum potential wind speed of updrafts ( W max ) and 0-6 km wind shear (Shear) have been found to represent conducive environments for severe weather, which subsequently provides a way to study severe weather in future climates. Here, we employ a model for the product of these variables (WmSh) from the National Center for Atmospheric Research/United States National Center for Environmental Prediction reanalysis over North America conditioned on their having extreme energy in the spatial field in order to project the predominant spatial patterns of WmSh. The approach is based on the Heffernan and Tawn conditional extreme value model. Results suggest that this technique estimates the spatial behavior of WmSh well, which allows for exploring possible changes in the patterns over time. While the model enables a method for inferring the uncertainty in the patterns, such analysis is difficult with the currently available inference approach. A variation of the method is also explored to investigate how this type of model might be used to qualitatively understand how the spatial patterns of WmSh correspond to extreme river flow events. A case study for river flows from three rivers in northwestern Tennessee is studied, and it is found that advection of WmSh from the Gulf of Mexico prevails while elsewhere, WmSh is generally very low during such extreme events. © 2013 The Authors. Environmetrics published by JohnWiley & Sons, Ltd.

LEVELS OF EXTREMELY LOW-FREQUENCY ELECTRIC AND MAGNETIC FIELDS FROM OVERHEAD POWER LINES IN THE OUTDOOR ENVIRONMENT OF RAMALLAH CITY-PALESTINE.

Science.gov (United States)

Abuasbi, Falastine; Lahham, Adnan; Abdel-Raziq, Issam Rashid

2018-05-01

In this study, levels of extremely low-frequency electric and magnetic fields originated from overhead power lines were investigated in the outdoor environment in Ramallah city, Palestine. Spot measurements were applied to record fields intensities over 6-min period. The Spectrum Analyzer NF-5035 was used to perform measurements at 1 m above ground level and directly underneath 40 randomly selected power lines distributed fairly within the city. Levels of electric fields varied depending on the line's category (power line, transformer or distributor), a minimum mean electric field of 3.9 V/m was found under a distributor line, and a maximum of 769.4 V/m under a high-voltage power line (66 kV). However, results of electric fields showed a log-normal distribution with the geometric mean and the geometric standard deviation of 35.9 and 2.8 V/m, respectively. Magnetic fields measured at power lines, on contrast, were not log-normally distributed; the minimum and maximum mean magnetic fields under power lines were 0.89 and 3.5 μT, respectively. As a result, none of the measured fields exceeded the ICNIRP's guidelines recommended for general public exposures to extremely low-frequency fields.

Modelling of extreme minimum rainfall using generalised extreme value distribution for Zimbabwe

Directory of Open Access Journals (Sweden)

Delson Chikobvu

2015-09-01

Full Text Available We modelled the mean annual rainfall for data recorded in Zimbabwe from 1901 to 2009. Extreme value theory was used to estimate the probabilities of meteorological droughts. Droughts can be viewed as extreme events which go beyond and/or below normal rainfall occurrences, such as exceptionally low mean annual rainfall. The duality between the distribution of the minima and maxima was exploited and used to fit the generalised extreme value distribution (GEVD to the data and hence find probabilities of extreme low levels of mean annual rainfall. The augmented Dickey Fuller test confirmed that rainfall data were stationary, while the normal quantile-quantile plot indicated that rainfall data deviated from the normality assumption at both ends of the tails of the distribution. The maximum likelihood estimation method and the Bayesian approach were used to find the parameters of the GEVD. The Kolmogorov-Smirnov and Anderson-Darling goodnessof- fit tests showed that the Weibull class of distributions was a good fit to the minima mean annual rainfall using the maximum likelihood estimation method. The mean return period estimate of a meteorological drought using the threshold value of mean annual rainfall of 473 mm was 8 years. This implies that if in the year there is a meteorological drought then another drought of the same intensity or greater is expected after 8 years. It is expected that the use of Bayesian inference may better quantify the level of uncertainty associated with the GEVD parameter estimates than with the maximum likelihood estimation method. The Markov chain Monte Carlo algorithm for the GEVD was applied to construct the model parameter estimates using the Bayesian approach. These findings are significant because results based on non-informative priors (Bayesian method and the maximum likelihood method approach are expected to be similar.

Fiscal 1992 achievement report on next-generation industrial structure technology. Research and development of advanced materials for extreme environments (Development of high efficiency power generation component creation technology); 1992 nendo chotaikankyosei senshin zairyo no kenkyu kaihatsu seika hokokusho. Kokoritsu hatsuden'yo buzai no sosei gijutsu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-03-01

Studies were made to develop technologies for creating carbon based advanced composite materials for use under extreme environments, and a comprehensive technology survey was conducted in this connection. Studied in the comprehensive survey were coordination between various technology developing activities, research on trends of relevant technologies, and technical tasks to discharge for the development of materials usable under extreme environments. In addition, interim evaluation was performed. Carried out in the development of C/C (carbon/carbon) composite materials using coal pitch derived fibers were carbon matrix optimization and studies of rupture mechanism, and the fabrication of specimens by compounding and molding under the hot press method and HIP (hot isostatic process). Carried out in the development of C/C composite materials using PAN (polyacrylonitrile) based carbon fibers were studies of rupture mechanism and the like, fabrication of specimens by compounding and molding, and performance enhancement under the high pressure impregnation carbonization method and the like. Oxidation resistant coatings were fabricated and tested for performance, and preliminary experiments were conducted toward the development of a novel coating technology. (NEDO)

High diversity and suggested endemicity of culturable Actinobacteria in an extremely oligotrophic desert oasis

Directory of Open Access Journals (Sweden)

Hector Fernando Arocha-Garza

2017-05-01

Full Text Available The phylum Actinobacteria constitutes one of the largest and anciently divergent phyla within the Bacteria domain. Actinobacterial diversity has been thoroughly researched in various environments due to its unique biotechnological potential. Such studies have focused mostly on soil communities, but more recently marine and extreme environments have also been explored, finding rare taxa and demonstrating dispersal limitation and biogeographic patterns for Streptomyces. To test the distribution of Actinobacteria populations on a small scale, we chose the extremely oligotrophic and biodiverse Cuatro Cienegas Basin (CCB, an endangered oasis in the Chihuahuan desert to assess the diversity and uniqueness of Actinobacteria in the Churince System with a culture-dependent approach over a period of three years, using nine selective media. The 16S rDNA of putative Actinobacteria were sequenced using both bacteria universal and phylum-specific primer pairs. Phylogenetic reconstructions were performed to analyze OTUs clustering and taxonomic identification of the isolates in an evolutionary context, using validated type species of Streptomyces from previously phylogenies as a reference. Rarefaction analysis for total Actinobacteria and for Streptomyces isolates were performed to estimate species’ richness in the intermediate lagoon (IL in the oligotrophic Churince system. A total of 350 morphologically and nutritionally diverse isolates were successfully cultured and characterized as members of the Phylum Actinobacteria. A total of 105 from the total isolates were successfully subcultured, processed for DNA extraction and 16S-rDNA sequenced. All strains belong to the order Actinomycetales, encompassing 11 genera of Actinobacteria; the genus Streptomyces was found to be the most abundant taxa in all the media tested throughout the 3-year sampling period. Phylogenetic analysis of our isolates and another 667 reference strains of the family Streptomycetaceae

High diversity and suggested endemicity of culturable Actinobacteria in an extremely oligotrophic desert oasis

Science.gov (United States)

Arocha-Garza, Hector Fernando; Canales-Del Castillo, Ricardo; Eguiarte, Luis E.; Souza, Valeria

2017-01-01

The phylum Actinobacteria constitutes one of the largest and anciently divergent phyla within the Bacteria domain. Actinobacterial diversity has been thoroughly researched in various environments due to its unique biotechnological potential. Such studies have focused mostly on soil communities, but more recently marine and extreme environments have also been explored, finding rare taxa and demonstrating dispersal limitation and biogeographic patterns for Streptomyces. To test the distribution of Actinobacteria populations on a small scale, we chose the extremely oligotrophic and biodiverse Cuatro Cienegas Basin (CCB), an endangered oasis in the Chihuahuan desert to assess the diversity and uniqueness of Actinobacteria in the Churince System with a culture-dependent approach over a period of three years, using nine selective media. The 16S rDNA of putative Actinobacteria were sequenced using both bacteria universal and phylum-specific primer pairs. Phylogenetic reconstructions were performed to analyze OTUs clustering and taxonomic identification of the isolates in an evolutionary context, using validated type species of Streptomyces from previously phylogenies as a reference. Rarefaction analysis for total Actinobacteria and for Streptomyces isolates were performed to estimate species’ richness in the intermediate lagoon (IL) in the oligotrophic Churince system. A total of 350 morphologically and nutritionally diverse isolates were successfully cultured and characterized as members of the Phylum Actinobacteria. A total of 105 from the total isolates were successfully subcultured, processed for DNA extraction and 16S-rDNA sequenced. All strains belong to the order Actinomycetales, encompassing 11 genera of Actinobacteria; the genus Streptomyces was found to be the most abundant taxa in all the media tested throughout the 3-year sampling period. Phylogenetic analysis of our isolates and another 667 reference strains of the family Streptomycetaceae shows that our

Calculation of neutron fluence-to-dose conversion factors for extremities

International Nuclear Information System (INIS)

Stewart, R.D.; Harty, R.; McDonald, J.C.; Tanner, J.E.

1993-04-01

The Pacific Northwest Laboratory is developing a standard for the performance testing of personnel extremity dosimeters for the US Department of Energy. Part of this effort requires the calculation of neutron fluence-to-dose conversion factors for finger and wrist extremities. This study focuses on conversion factors for two types of extremity models: namely the polymethyl methacrylate (PMMA) phantom (as specified in the draft standard for performance testing of extremity dosimeters) and more realistic extremity models composed of tissue-and-bone. Calculations for each type of model are based on both bare and D 2 O-moderated 252 Cf sources. The results are then tabulated and compared with whole-body conversion factors. More appropriate energy-averaged quality factors for the extremity models have also been computed from the neutron fluence in 50 equally spaced energy bins with energies from 2.53 x 10 -8 to 15 MeV. Tabulated results show that conversion factors for both types of extremity phantom are 15 to 30% lower than the corresponcung whole-body phantom conversion factors for 252 Cf neutron sources. This difference in extremity and whole-body conversion factors is attributable to the proportionally smaller amount of back-scattering that occurs in the extremity phantoms compared with whole-body phantoms

Isolation and characterization of extreme halophilic archaea

Energy Technology Data Exchange (ETDEWEB)

Franze, Madlen; Cherkouk, Andrea [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). HZDR Young Investigator Group

2017-06-01

Extreme halophilic archaea from the family Halobactereacea represent a dominant part of the microbial community present in saline soils as well as rock salts. By using a culture-dependent approach different Haloarchaea could be isolated and were phylogenetic analysed. Interestingly, isolates closely related to different Halobacterium spp. were found in both environments.

Isolation and characterization of extreme halophilic archaea

International Nuclear Information System (INIS)

Franze, Madlen; Cherkouk, Andrea

2017-01-01

Extreme halophilic archaea from the family Halobactereacea represent a dominant part of the microbial community present in saline soils as well as rock salts. By using a culture-dependent approach different Haloarchaea could be isolated and were phylogenetic analysed. Interestingly, isolates closely related to different Halobacterium spp. were found in both environments.

DEVELOPMENT OF KITSAT-1 AND 2 MECHANICAL SYSTEM AND RESULTS OF ENVIRONMENT TEST

Directory of Open Access Journals (Sweden)

J. S. Bae

1996-06-01

Full Text Available The satellite experiences the launch environment such as vibration, acceleration, shock induced by rocket and the orbit environment such as high vacuum, no gravity, high temperature and cryogenic. Therefore, the satellite should be designed and manufactured to endure such environments. Also, special care must be taken on the assembly of parts and subsystem. Finally, we describe the environment test of microsatellite to ensure the reliable operation during launch period as well as in-orbit operation.

Contribution of eukaryotic microbial communities to the formation of Fe-rich accretions in an extreme acidic environment

Science.gov (United States)

Rodrigues, L.; Valente, T.; Correia, A.; Alves, A.; Foing, B.; Davies, G. R.

2012-04-01

In the acid mine drainage of Valdarcas, northern Portugal, Fe-rich tubular and spherical macroaccretions are directly associated with the presence of eukaryotic microorganisms. This raises the question whether they are biogenically-derived or the result of an abiotic process mediated by microeukaryotic phototrophs. The drainage water at Valdarcas is characterized by very low pH values (pHhigh metal solubility and presence of iron colloids. Mineralogical analysis (XRD and SEM) of the precipitates indicates a mixture of goethite, schwertmannite and jarosite. Euglenophyta and Chlorophyta acidophilic algal were previously identified in this site. The spatial distribution of Euglena mutabilis indicated that it has a preference to grow up on schwertmannite-rich precipitates. Field observations demonstrate the existence of oxygenated microenvironments created by algal activity suggesting that algae influence iron minerals precipitation, especially schwertmannite. The mineral-microorganism interactions are relevant to understanding this unique and extreme environment. Further investigations regarding the mineralogical and chemical characterization of these deposits, and the identification of microorganisms involved in the process could be helpful to enhance our knowledge of past Fe formations throughout Earth's primordial environment. It is expectable that this information will contribute to establish a framework for recognition of biosignatures on other planets and extraterrestrial bodies. In this study, results on the chemical and mineralogical composition of the structures are presented. The biological context is characterised based on observations made by optical microscopy complemented with molecular data on the microbial communities obtained by culture independent methods. The results are discussed within the context of two models: the studied Fe-rich stromatolites are microeukaryotic-mediated as described by previous workers from similar environments or are the

Identification of Climate Change with Generalized Extreme Value (GEV) Distribution Approach

International Nuclear Information System (INIS)

Rahayu, Anita

2013-01-01

Some events are difficult to avoid and gives considerable influence to humans and the environment is extreme weather and climate change. Many of the problems that require knowledge about the behavior of extreme values and one of the methods used are the Extreme Value Theory (EVT). EVT used to draw up reliable systems in a variety of conditions, so as to minimize the risk of a major disaster. There are two methods for identifying extreme value, Block Maxima with Generalized Extreme Value (GEV) distribution approach and Peaks over Threshold (POT) with Generalized Pareto Distribution (GPD) approach. This research in Indramayu with January 1961-December 2003 period, the method used is Block Maxima with GEV distribution approach. The result showed that there is no climate change in Indramayu with January 1961-December 2003 period.

Design, conception, and metrology of Extreme Ultraviolet multilayers mirrors resistant environments of space and EUV sources; Conception, realisation et metrologie de miroirs multicouches pour l'extreme ultraviolet resistants aux environnements du spatial et des sources EUV

Energy Technology Data Exchange (ETDEWEB)

Hecquet, Ch.

2009-03-15

The Extreme Ultraviolet Spectrum (EUV) wavelengths, which range between 13 nm and 40 nm, have many applications in science and technology. These have been developed for example in plasma physics (high order harmonics sources, X ray lasers). The work presented is about the design, the fabrication and the metrology of periodic multilayer mirrors. The main motivation of this study is to establish a cycle of development taking into account both the optical properties of reflective coatings (reflectivity, spectral selectivity, attenuation) and their behaviour under various environments. To improve the spectral selectivity, new multilayer periodic structures have been developed. They are characterized by a bimodal reflectance profile with adjustable attenuation. The effect of environment on the stability of performance is especially critical for the optical collection. The addition of material barriers has stabilized the performance of the peak reflectivity for over 200 h at 400 C deg. and it reduces the influence of other factors of instability on the reflectance. In addition, all structures have been fabricated successfully and evaluated in severe environments. (author)

Variations in morphological and life-history traits under extreme ...

Indian Academy of Sciences (India)

Two extremely stressful temperatures (18°C and 32°C) and one standard ... and non-stressful environments on the morphological and life-history traits in males and ... Genetics Laboratory, Department of Zoology, Banaras Hindu University, ...

Evaluation of teleoperated surgical robots in an enclosed undersea environment.

Science.gov (United States)

Doarn, Charles R; Anvari, Mehran; Low, Thomas; Broderick, Timothy J

2009-05-01

The ability to support surgical care in an extreme environment is a significant issue for both military medicine and space medicine. Telemanipulation systems, those that can be remotely operated from a distant site, have been used extensively by the National Aeronautics and Space Administration (NASA) for a number of years. These systems, often called telerobots, have successfully been applied to surgical interventions. A further extension is to operate these robotic systems over data communication networks where robotic slave and master are separated by a great distance. NASA utilizes the National Oceanographic and Atmospheric Administration (NOAA) Aquarius underwater habitat as an analog environment for research and technology evaluation missions, known as NASA Extreme Environment Mission Operations (NEEMO). Three NEEMO missions have provided an opportunity to evaluate teleoperated surgical robotics by astronauts and surgeons. Three robotic systems were deployed to the habitat for evaluation during NEEMO 7, 9, and 12. These systems were linked via a telecommunications link to various sites for remote manipulation. Researchers in the habitat conducted a variety of tests to evaluate performance and applicability in extreme environments. Over three different NEEMO missions, components of the Automated Endoscopic System for Optimal Positioning (AESOP), the M7 Surgical System, and the RAVEN were deployed and evaluated. A number of factors were evaluated, including communication latency and semiautonomous functions. The M7 was modified to permit a remote surgeon the ability to insert a needle into simulated tissue with ultrasound guidance, resulting in the world's first semi-autonomous supervisory-controlled medical task. The deployment and operation of teleoperated surgical systems and semi-autonomous, supervisory-controlled tasks were successfully conducted.

A Multi-Environment Thermal Control System With Freeze-Tolerant Radiator

Science.gov (United States)

Chen, Weibo; Fogg, David; Mancini, Nick; Steele, John; Quinn, Gregory; Bue, Grant; Littibridge, Sean

2013-01-01

Future space exploration missions require advanced thermal control systems (TCS) to dissipate heat from spacecraft, rovers, or habitats operating in environments that can vary from extremely hot to extremely cold. A lightweight, reliable TCS is being developed to effectively control cabin and equipment temperatures under widely varying heat loads and ambient temperatures. The system uses freeze-tolerant radiators, which eliminate the need for a secondary circulation loop or heat pipe systems. Each radiator has a self-regulating variable thermal conductance to its ambient environment. The TCS uses a nontoxic, water-based working fluid that is compatible with existing lightweight aluminum heat exchangers. The TCS is lightweight, compact, and requires very little pumping power. The critical characteristics of the core enabling technologies were demonstrated. Functional testing with condenser tubes demonstrated the key operating characteristics required for a reliable, freeze-tolerant TCS, namely (1) self-regulating thermal conductance with short transient responses to varying thermal loads, (2) repeatable performance through freeze-thaw cycles, and (3) fast start-up from a fully frozen state. Preliminary coolant tests demonstrated that the corrosion inhibitor in the water-based coolant can reduce the corrosion rate on aluminum by an order of magnitude. Performance comparison with state-of-the-art designs shows significant mass and power saving benefits of this technology.

Assessment of the risk of falling with the use of timed up and go test in the elderly with lower extremity osteoarthritis.

Science.gov (United States)

Zasadzka, Ewa; Borowicz, Adrianna Maria; Roszak, Magdalena; Pawlaczyk, Mariola

2015-01-01

Falling in the elderly results in a significant number of admissions to hospitals and long-term care facilities, especially among patients with lower extremity osteoarthritis (OA). The aim of the study was to assess the risk of falling in adults older than 60 years with OA using timed up and go (TUG) test. A total of 187 patients (aged >60 years) were enrolled in the study. The assessment included: basic activities of daily living (ADLs), lower extremity strength with the use of the 30-second chair stand test (30 CST), and assessment of the risk of falling (TUG test). Pain intensity was evaluated with the numeric rating scale (NRS). The TUG test results were significantly better in younger OA patients (aged 60-69 years), as compared with their older peers (aged 70-79 years; P80 years; Pwomen than men (Pfalls was significantly higher in the group of subjects who scored ≥13.5 when compared to risk of falling, which increases with progressing age, pain, and muscle weakness. It seems prudent to identify individuals at a high risk of falling and to propose an adequate treatment for them.

STRUCTURAL SCALE LIFE PREDICTION OF AERO STRUCTURES EXPERIENCING COMBINED EXTREME ENVIRONMENTS

Science.gov (United States)

2017-07-01

complex loading environments. Today’s state of the art methods cannot address structural reliability under combined environment conditions due to...probabilistically assess the structural life under complex loading environments. Today’s state of the art methods cannot address structural reliability...Institute of Aeronautics and Astronautics, San Diego, CA, January 4th‐8th, 2016. Clark, L. D., Bae, H., Gobal, K., and Penmetsa, R., “ Engineering

Evaluation of Extremal Hypotheses as a Criterion to Resolve Channel Indeterminacy

Science.gov (United States)

Tranmer, A.

2012-12-01

Design criteria for river restoration and sustainable development have significantly advanced in recent decades, yet complete deterministic formulations to address channel form and sinuosity still prove elusive. Many hypotheses have been presented to ascertain the dynamic-equilibrium of a stream at both the cross sectional and reach level. These efforts to better understand the functioning of alluvial systems include regime theory, stability theory, perturbation analysis, threshold theory, reference reach comparison, downstream hydraulic geometry, and extremal hypotheses. The latter of these theories, the extremal hypothesis, is based on optimizing one variable or criterion in the alluvial system in order to find closure to the channel design problem. Currently, there is no method to directly compare the various hypotheses at the system scale, understanding of their sensitivity to the various formulae employed or consensus regarding which hypothesis is most appropriate. This study analyzed the various extremal hypotheses in as close to a pristine environment as exists (a remote part of Patagonia, Chile), in order to assess which hypothesis (or collective hypotheses) is most appropriate for channel design. Extremal hypotheses were applied in the longitudinal direction, under the assumption of a space-for-time substitution, to evaluate the geomorphic trends of a river evolving during deglaciation. The space-for-time model assumes the watershed reaches stable, dynamic-equilibrium in its lower meandering reaches and the point of equilibrium extends upstream through its braiding reaches as the watershed adapts to new climatic and environmental conditions. Extremal hypotheses applied in a downstream fashion are then expected to predict chaotic and oversized channel characteristics in the upstream reaches and trend towards a point of equilibrium (minimum/maximum of tested hypothesis). Initial findings indicate that many hypotheses predict similar geometry and sinuosity

Empirical usability testing in a component-based environment : improving test efficiency with component-specific usability measures

NARCIS (Netherlands)

Brinkman, W.P.; Haakma, R.; Bouwhuis, D.G.; Bastide, R.; Palanque, P.; Roth, J.

2005-01-01

This paper addresses the issue of usability testing in a component-based software engineering environment, specifically measuring the usability of different versions of a component in a more powerful manner than other, more holistic, usability methods. Three component-specific usability measures are

Concept for waste package environment tests in the Yucca Mountain exploratory shaft

International Nuclear Information System (INIS)

Yow, J.L. Jr.

1985-05-01

The Nevada Nuclear Waste Storage Investigations (NNWSI) project is studying a tuffaceous rock unit located at Yucca Mountain on the western boundary of the Nevada Test Site, Nye County, Nevada. The objective is to evaluate the suitability of the volcanic rocks located above the water table at Yucca Mountain as a potential location for a repository for high level radioactive waste. As part of the NNWSI project, Lawrence Livermore National Laboratory is responsible for the design of the waste package and for determining the expected performance of the waste package in the repository environment. To design an optimal waste package system for the unsaturated emplacement environment, the mechanisms by which liquid water can return to contact the metal canister after peaking of the thermal load must be established. Definition of these flux and flow mechanisms is essential for estimating canister corrosion modes and rates. Therefore, three waste package environment tests are being designed for the in situ phase of exploratory shaft testing. These tests emphasize measurement techniques that offer the possibility of characterizing the movement of water into and through the pores and fractures of the densely welded Topopah Spring Member. Other measurement techniques will be used to examine the interactions between moisture migration and the thermomechanical rock mass behavior. Three reduced-scale heater tests will use electrical resistive heaters in a horizontal configuration. All three tests are designed to investigate moisture conditions in the rock during heating and cooling phases of a thermal cycle so that the effects of these moisture conditions on the performance of the waste package system may be established. 28 refs., 4 figs., 3 tabs

Species-specific coral calcification responses to the extreme environment of the southern Persian Gulf

DEFF Research Database (Denmark)

Howells, Emily J.; Dunshea, Glenn John; McParland, Dain

2018-01-01

Sustained accretion of calcium carbonate (mostly by scleractinian corals) is fundamental for maintaining the structure and function of coral reef ecosystems, but may be greatly constrained by extreme and rapidly changing environmental conditions. Corals in the southern Persian Gulf already...... experience extreme temperature ranges ( 34°C), chronic hypersalinity (> 43 psu) and frequent light limitation (coral species in the region (Platygyra daedalea and Cyphastrea microphthalma) along marked...... Persian Gulf was lowest at Ras Ghanada, where there was lowest light and highest maximum temperatures. These data reveal striking taxonomic differences in the specific environmental constraints on coral calcification, which will further reinforce changes in the structure of coral assemblages with ongoing...

QUEST/Ada: Query utility environment for software testing of Ada

Science.gov (United States)

Brown, David B.

1989-01-01

Results of research and development efforts are presented for Task 1, Phase 2 of a general project entitled, The Development of a Program Analysis Environment for Ada. A prototype of the QUEST/Ada system was developed to collect data to determine the effectiveness of the rule-based testing paradigm. The prototype consists of five parts: the test data generator, the parser/scanner, the test coverage analyzer, a symbolic evaluator, and a data management facility, known as the Librarian. These components are discussed at length. Also presented is an experimental design for the evaluations, an overview of the project, and a schedule for its completion.

Effects of aquatic PNF lower extremity patterns on balance and ADL of stroke patients

OpenAIRE

Kim, Eun-Kyung; Lee, Dong-Kyu; Kim, Young-Mi

2015-01-01

[Purpose] This study investigated the effect of aquatic proprioceptive neuromuscular facilitation (PNF) patterns in the lower extremity on balance and activities of daily living (ADL) in stroke patients. [Subjects] Twenty poststroke participants were randomly assigned to an experimental group (n = 10) or a control group (n = 10). The experimental group performed lower extremity patterns in an aquatic environment, and the control group performed lower extremity patterns on the ground. Both exe...

Comparing the Effects of Dual-Task Gait Testing in New and Established Ambulators With Lower Extremity Amputations.

Science.gov (United States)

Frengopoulos, Courtney; Payne, Michael W C; Holmes, Jeffrey D; Viana, Ricardo; Hunter, Susan W

2018-04-05

Gait is a complex process that involves coordinating motor and sensory systems through higher-order cognitive processes. Walking with a prosthesis after lower extremity amputation challenges these processes. However, the factors that influence the cognitive-motor interaction in gait among lower extremity amputees has not been evaluated. To assess the interaction of cognition and mobility, individuals must be evaluated using the dual-task paradigm. To investigate the effect of etiology and time with prosthesis on dual-task performance in those with lower extremity amputations. Cross-sectional study. Outpatient and inpatient amputee clinics at an academic rehabilitation hospital. Sixty-four individuals (aged 58.20±12.27 years; 74.5% male) were stratified into 3 groups; 1 group of new prosthetic ambulators with transtibial amputations (NewPA) and 2 groups of established ambulators: transtibial amputations of vascular etiology (TTA-vas), transtibial amputations of nonvascular etiology (TTA-nonvas). Not applicable. Time to complete the L Test measured functional mobility under single and dual-task conditions. A serial arithmetic task (subtraction by 3s) was paired with the L Test to create the dual-task test condition. Single-task performance on the cognitive arithmetic task was also recorded. Dual-task costs (DTCs) were calculated for performance on the cognitive and gait tasks. Analysis of variance determined differences between groups. A performance-resource operating characteristic (POC) graph was used to graphically display DTCs. Gait performance was worse under dual-task conditions for all groups. Gait was significantly slower under dual-task conditions for the TTA-vas (P Dual-task conditions also had a negative impact on cognitive task performance for the TTA-nonvas (P = .02) and NewPA groups (P dual-task conditions and has a positive DTCcog as a result (P = .04). However, no between-group differences were seen for DTCcog. The POC graph demonstrated that many

Ionospheric Response to Extremes in the Space Environment: Establishing Benchmarks for the Space Weather Action Plan.

Science.gov (United States)

Viereck, R. A.; Azeem, S. I.

2017-12-01

One of the goals of the National Space Weather Action Plan is to establish extreme event benchmarks. These benchmarks are estimates of environmental parameters that impact technologies and systems during extreme space weather events. Quantitative assessment of anticipated conditions during these extreme space weather event will enable operators and users of affected technologies to develop plans for mitigating space weather risks and improve preparedness. The ionosphere is one of the most important regions of space because so many applications either depend on ionospheric space weather for their operation (HF communication, over-the-horizon radars), or can be deleteriously affected by ionospheric conditions (e.g. GNSS navigation and timing, UHF satellite communications, synthetic aperture radar, HF communications). Since the processes that influence the ionosphere vary over time scales from seconds to years, it continues to be a challenge to adequately predict its behavior in many circumstances. Estimates with large uncertainties, in excess of 100%, may result in operators of impacted technologies over or under preparing for such events. The goal of the next phase of the benchmarking activity is to reduce these uncertainties. In this presentation, we will focus on the sources of uncertainty in the ionospheric response to extreme geomagnetic storms. We will then discuss various research efforts required to better understand the underlying processes of ionospheric variability and how the uncertainties in ionospheric response to extreme space weather could be reduced and the estimates improved.

Localized corrosion of high performance metal alloys in an acid/salt environment

Science.gov (United States)

Macdowell, L. G.; Ontiveros, C.

1991-01-01

Various vacuum jacketed cryogenic supply lines at the Space Shuttle launch site at Kennedy Space Center use convoluted flexible expansion joints. The atmosphere at the launch site has a very high salt content, and during a launch, fuel combustion products include hydrochloric acid. This extremely corrosive environment has caused pitting corrosion failure in the thin walled 304L stainless steel flex hoses. A search was done to find a more corrosion resistant replacement material. The study focussed on 19 metal alloys. Tests which were performed include electrochemical corrosion testing, accelerated corrosion testing in a salt fog chamber, and long term exposure at a beach corrosion testing site. Based on the results of these tests, several nickel based alloys were found to have very high resistance to this corrosive environment. Also, there was excellent agreement between the electrochemical tests and the actual beach exposure tests. This suggests that electrochemical testing may be useful for narrowing the field of potential candidate alloys before subjecting samples to long term beach exposure.

Design, comparison, and testing of a new user-friendly extremity dosimetry system

Energy Technology Data Exchange (ETDEWEB)

Stadtmann, H.; Schmitzer, C.; Michler, E. [Austrian Research Centre, Seibersdorf (Austria); Fellinger, J.; Velbeck, K.J.; Rotunda, J.E. [BICRON RMP, Solon (United States)

2000-05-01

A new extremity TLD system has been developed and tested that provides for user convenience and automated processing while meeting various accreditation requirements. The design is a result of successful collaboration among organisational entities in different countries and included research centres, users, and the manufacturer. The primary consideration was to meet the needs of the medical market, without losing sight of the needs of research laboratories and power plants. This dosimetry system design provides various detector designs based on the need to measure photons or betas. Beyond the fundamental need for accurate dosimetry, the system meets the customers need for a versatile and comfortable ring and provides for both hot and cold sterilisation. The system represents a unique integration of components comprising the finger ring, dosimeter and dosimeter identification system, and TLD Instruments. The dosimeter identification system in the TLD Reader incorporates a CCD Camera and Machine Vision Technology to interpret the circular bar codes used to quickly and accurately identifies each individual dosimeter. Portability of this dosimetry system has been realised with the adaptation into multiple TLD Instruments. (author)

Design, comparison, and testing of a new user-friendly extremity dosimetry system

International Nuclear Information System (INIS)

Stadtmann, H.; Schmitzer, C.; Michler, E.; Fellinger, J.; Velbeck, K.J.; Rotunda, J.E.

2000-01-01

A new extremity TLD system has been developed and tested that provides for user convenience and automated processing while meeting various accreditation requirements. The design is a result of successful collaboration among organisational entities in different countries and included research centres, users, and the manufacturer. The primary consideration was to meet the needs of the medical market, without losing sight of the needs of research laboratories and power plants. This dosimetry system design provides various detector designs based on the need to measure photons or betas. Beyond the fundamental need for accurate dosimetry, the system meets the customers need for a versatile and comfortable ring and provides for both hot and cold sterilisation. The system represents a unique integration of components comprising the finger ring, dosimeter and dosimeter identification system, and TLD Instruments. The dosimeter identification system in the TLD Reader incorporates a CCD Camera and Machine Vision Technology to interpret the circular bar codes used to quickly and accurately identifies each individual dosimeter. Portability of this dosimetry system has been realised with the adaptation into multiple TLD Instruments. (author)

The Performance test of Mechanical Sodium Pump with Water Environment

International Nuclear Information System (INIS)

Cho, Chungho; Kim, Jong-Man; Ko, Yung Joo; Jeong, Ji-Young; Kim, Jong-Bum; Ko, Bock Seong; Park, Sang Jun; Lee, Yoon Sang

2015-01-01

As contrasted with PWR(Pressurized light Water Reactor) using water as a coolant, sodium is used as a coolant in SFR because of its low melting temperature, high thermal conductivity, the high boiling temperature allowing the reactors to operate at ambient pressure, and low neutron absorption cross section which is required to achieve a high neutron flux. But, sodium is violently reactive with water or oxygen like the other alkali metal. So Very strict requirements are demanded to design and fabricate of sodium experimental facilities. Furthermore, performance testing in high temperature sodium environments is more expensive and time consuming and need an extra precautions because operating and maintaining of sodium experimental facilities are very difficult. The present paper describes performance test results of mechanical sodium pump with water which has been performed with some design changes using water test facility in SAM JIN Industrial Co. To compare the hydraulic characteristic of model pump with water and sodium, the performance test of model pump were performed using vender's experimental facility for mechanical sodium pump. To accommodate non-uniform thermal expansion and to secure the operability and the safety, the gap size of some parts of original model pump was modified. Performance tests of modified mechanical sodium pump with water were successfully performed. Water is therefore often selected as a surrogate test fluid because it is not only cheap, easily available and easy to handle but also its important hydraulic properties (density and kinematic viscosity) are very similar to that of the sodium. Normal practice to thoroughly test a design or component before applied or installed in reactor is important to ensure the safety and operability in the sodium-cooled fast reactor (SFR). So, in order to estimate the hydraulic behavior of the PHTS pump of DSFR (600 MWe Demonstraion SFR), the performance tests of the model pump such as performance

More tornadoes in the most extreme U.S. tornado outbreaks.

Science.gov (United States)

Tippett, Michael K; Lepore, Chiara; Cohen, Joel E

2016-12-16

Tornadoes and severe thunderstorms kill people and damage property every year. Estimated U.S. insured losses due to severe thunderstorms in the first half of 2016 were $8.5 billion (US). The largest U.S. effects of tornadoes result from tornado outbreaks, which are sequences of tornadoes that occur in close succession. Here, using extreme value analysis, we find that the frequency of U.S. outbreaks with many tornadoes is increasing and that it is increasing faster for more extreme outbreaks. We model this behavior by extreme value distributions with parameters that are linear functions of time or of some indicators of multidecadal climatic variability. Extreme meteorological environments associated with severe thunderstorms show consistent upward trends, but the trends do not resemble those currently expected to result from global warming. Copyright © 2016, American Association for the Advancement of Science.

QUEST/Ada (Query Utility Environment for Software Testing of Ada): The development of a prgram analysis environment for Ada, task 1, phase 2

Science.gov (United States)

Brown, David B.

1990-01-01

The results of research and development efforts are described for Task one, Phase two of a general project entitled The Development of a Program Analysis Environment for Ada. The scope of this task includes the design and development of a prototype system for testing Ada software modules at the unit level. The system is called Query Utility Environment for Software Testing of Ada (QUEST/Ada). The prototype for condition coverage provides a platform that implements expert system interaction with program testing. The expert system can modify data in the instrument source code in order to achieve coverage goals. Given this initial prototype, it is possible to evaluate the rule base in order to develop improved rules for test case generation. The goals of Phase two are the following: (1) to continue to develop and improve the current user interface to support the other goals of this research effort (i.e., those related to improved testing efficiency and increased code reliable); (2) to develop and empirically evaluate a succession of alternative rule bases for the test case generator such that the expert system achieves coverage in a more efficient manner; and (3) to extend the concepts of the current test environment to address the issues of Ada concurrency.

Modeling the Gas Dynamics Environment in a Subscale Solid Rocket Test Motor

Science.gov (United States)

Eaton, Andrew M.; Ewing, Mark E.; Bailey, Kirk M.; McCool, Alex (Technical Monitor)

2001-01-01

Subscale test motors are often used for the evaluation of solid rocket motor component materials such as internal insulation. These motors are useful for characterizing insulation performance behavior, screening insulation material candidates and obtaining material thermal and ablative property design data. One of the primary challenges associated with using subscale motors however, is the uncertainty involved when extrapolating the results to full-scale motor conditions. These uncertainties are related to differences in such phenomena as turbulent flow behavior and boundary layer development, propellant particle interactions with the wall, insulation off-gas mixing and thermochemical reactions with the bulk flow, radiation levels, material response to the local environment, and other anomalous flow conditions. In addition to the need for better understanding of physical mechanisms, there is also a need to better understand how to best simulate these phenomena using numerical modeling approaches such as computational fluid dynamics (CFD). To better understand and model interactions between major phenomena in a subscale test motor, a numerical study of the internal flow environment of a representative motor was performed. Simulation of the environment included not only gas dynamics, but two-phase flow modeling of entrained alumina particles like those found in an aluminized propellant, and offgassing from wall surfaces similar to an ablating insulation material. This work represents a starting point for establishing the internal environment of a subscale test motor using comprehensive modeling techniques, and lays the groundwork for improving the understanding of the applicability of subscale test data to full-scale motors. It was found that grid resolution, and inclusion of phenomena in addition to gas dynamics, such as two-phase and multi-component gas composition are all important factors that can effect the overall flow field predictions.

Hydrologic extremes - an intercomparison of multiple gridded statistical downscaling methods

Science.gov (United States)

Werner, Arelia T.; Cannon, Alex J.

2016-04-01

Gridded statistical downscaling methods are the main means of preparing climate model data to drive distributed hydrological models. Past work on the validation of climate downscaling methods has focused on temperature and precipitation, with less attention paid to the ultimate outputs from hydrological models. Also, as attention shifts towards projections of extreme events, downscaling comparisons now commonly assess methods in terms of climate extremes, but hydrologic extremes are less well explored. Here, we test the ability of gridded downscaling models to replicate historical properties of climate and hydrologic extremes, as measured in terms of temporal sequencing (i.e. correlation tests) and distributional properties (i.e. tests for equality of probability distributions). Outputs from seven downscaling methods - bias correction constructed analogues (BCCA), double BCCA (DBCCA), BCCA with quantile mapping reordering (BCCAQ), bias correction spatial disaggregation (BCSD), BCSD using minimum/maximum temperature (BCSDX), the climate imprint delta method (CI), and bias corrected CI (BCCI) - are used to drive the Variable Infiltration Capacity (VIC) model over the snow-dominated Peace River basin, British Columbia. Outputs are tested using split-sample validation on 26 climate extremes indices (ClimDEX) and two hydrologic extremes indices (3-day peak flow and 7-day peak flow). To characterize observational uncertainty, four atmospheric reanalyses are used as climate model surrogates and two gridded observational data sets are used as downscaling target data. The skill of the downscaling methods generally depended on reanalysis and gridded observational data set. However, CI failed to reproduce the distribution and BCSD and BCSDX the timing of winter 7-day low-flow events, regardless of reanalysis or observational data set. Overall, DBCCA passed the greatest number of tests for the ClimDEX indices, while BCCAQ, which is designed to more accurately resolve event

Development and psychometric testing of the Nursing Workplace Relational Environment Scale (NWRES).

Science.gov (United States)

Duddle, Maree; Boughton, Maureen

2009-03-01

The aim of this study was to develop and test the psychometric properties of the Nursing Workplace Relational Environment Scale (NWRES). A positive relational environment in the workplace is characterised by a sense of connectedness and belonging, support and cooperation among colleagues, open communication and effectively managed conflict. A poor relational environment in the workplace may contribute to job dissatisfaction and early turnover of staff. Quantitative survey. A three-stage process was used to design and test the NWRES. In Stage 1, an extensive literature review was conducted on professional working relationships and the nursing work environment. Three key concepts; collegiality, workplace conflict and job satisfaction were identified and defined. In Stage 2, a pool of items was developed from the dimensions of each concept and formulated into a 35-item scale which was piloted on a convenience sample of 31 nurses. In Stage 3, the newly refined 28-item scale was administered randomly to a convenience sample of 150 nurses. Psychometric testing was conducted to establish the construct validity and reliability of the scale. Exploratory factor analysis resulted in a 22-item scale. The factor analysis indicated a four-factor structure: collegial behaviours, relational atmosphere, outcomes of conflict and job satisfaction which explained 68.12% of the total variance. Cronbach's alpha coefficient for the NWRES was 0.872 and the subscales ranged from 0.781-0.927. The results of the study confirm the reliability and validity of the NWRES. Replication of this study with a larger sample is indicated to determine relationships among the subscales. The results of this study have implications for health managers in terms of understanding the impact of the relational environment of the workplace on job satisfaction and retention.

Fiscal 1991 achievement report on next-generation industrial structure technology. Research and development of advanced materials for extreme environments; 1991 nendo chotaikankyosei senshin zairyo no kenkyu kaihatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1992-03-01

Research and development was carried out for coal pitch derived and PAN (polyacrylonitrile) based carbon fiber/carbon matrix composite materials for use under high temperature environments. A comprehensive survey was also conducted on the same. For the development of C/C (carbon/carbon) composite materials using coal pitch derived or PAN based carbon fibers, fiber characteristics, surface treatment, matrix characteristics, and the like were studied for the optimization of fibers and matrices. In addition, studies were conducted of rupture mechanism and oxidation resistance and of compounding and molding technologies. An effort was made to study detailed conditions for systems of materials and methods for coating them, oxidation resistant coatings were fabricated and tested for performance, and basics were studied for the development of novel coating technologies. In the comprehensive survey, the latest technical trends inside and outside Japan were investigated, and studies were conducted about technical tasks necessary to discharge for the development of materials for use under extreme circumstances such as ultrahigh temperatures. (NEDO)

Radioassay for hydrogenase activity in viable cells and documentation of aerobic hydrogen-consuming bacteria living in extreme environments

International Nuclear Information System (INIS)

Schink, B.; Lupton, F.S.; Zeikus, J.G.

1983-01-01

An isotopic tracer assay based on the hydrogenase-dependent formation of tritiated water from tritium gas was developed for in life analysis of microbial hydrogen transformation. This method allowed detection of bacterial hydrogen metabolism in pure cultures or in natural samples obtained from aquatic ecosystems. A differentiation between chemical-biological and aerobic-anaerobic hydrogen metabolism was established by variation of the experimental incubation temperature or by addition of selective inhibitors. Hydrogenase activity was shown to be proportional to the consumption or production of hydrogen by cultures of Desulfovibrio vulgaris, Clostridium pasteurianum, and Methanosarcina barkeri. This method was applied, in connection with measurements of free hydrogen and most-probable-number enumerations, in aerobic natural source waters to establish the activity and document the ecology of hydrogen-consuming bacteria in extreme acid, thermal, or saline environments. The utility of the assay is based in part on the ability to quantify bacterial hydrogen transformation at natural hydrogen partial pressures, without the use of artificial electron acceptors

Prototype heater test of the environment around a simulated waste package

International Nuclear Information System (INIS)

Ramirez, A.L.; Buscheck, T.A.; Carlson, R.; Daily, W.; Latorre, V.R.; Lee, K; Lin, Wunan; Mao, Nai-hsien; Towse, D.; Ueng, Tzou-Shin; Watwood, D.

1991-01-01

This paper presents selected results obtained during the 301 day duration of the Prototype Engineered Barrier System Field Test (PEBSFT) performed in G-Tunnel within the Nevada Test Site. The test described is a precursor to the Engineered Barrier Systems Field Tests (EBSFT) planned for the Exploratory Shaft Facility in Yucca Mountain. The EBSFT will consist of in situ tests of the geohydrologic and geochemical environment in the near field (within a few meters) of heaters emplaced in welded tuff to simulate the thermal effects of waste packages. The paper discusses the evolution of hydrothermal behavior during the prototype test, including rock temperatures, changes in rock moisture content, air permeability of fractures and gas-phase humidity in the heater borehole

Temperature extremes: Effect on plant growth and development

Directory of Open Access Journals (Sweden)

Jerry L. Hatfield

2015-12-01

Full Text Available Temperature is a primary factor affecting the rate of plant development. Warmer temperatures expected with climate change and the potential for more extreme temperature events will impact plant productivity. Pollination is one of the most sensitive phenological stages to temperature extremes across all species and during this developmental stage temperature extremes would greatly affect production. Few adaptation strategies are available to cope with temperature extremes at this developmental stage other than to select for plants which shed pollen during the cooler periods of the day or are indeterminate so flowering occurs over a longer period of the growing season. In controlled environment studies, warm temperatures increased the rate of phenological development; however, there was no effect on leaf area or vegetative biomass compared to normal temperatures. The major impact of warmer temperatures was during the reproductive stage of development and in all cases grain yield in maize was significantly reduced by as much as 80−90% from a normal temperature regime. Temperature effects are increased by water deficits and excess soil water demonstrating that understanding the interaction of temperature and water will be needed to develop more effective adaptation strategies to offset the impacts of greater temperature extreme events associated with a changing climate.

Testing Single and Combinations of Amendments for Stabilization of Metals in Contrasting Extremely Contaminated Soils

Directory of Open Access Journals (Sweden)

Siebielec G.

2013-04-01

Full Text Available Metals can be stabilized by soil amendments that increase metals adsorption or alter their chemical forms. Such treatments may limit the risk related to the contamination through reduction of metal transfer to the food chain (reduction of metal uptake by plants and its availability to soil organisms and metals migration within the environment. There is a need for experiments comparing various soil amendments available at reasonable amounts under similar environmental conditions. The other question is whether all components of soil environment or soil functions are similarly protected after remediation treatment. We conducted a series of pot studies to test some traditional and novel amendments and their combinations. The treatments were tested for several highly Zn/Cd/Pb contaminated soils. Among traditional amendments composts were the most effective – they ensured plant growth, increased soil microbial activity, reduced Cd in earthworms, reduced Pb bioaccessibility and increased share of unavailable forms of Cd and Pb.

Gravo-Aeroelastic Scaling for Extreme-Scale Wind Turbines

Energy Technology Data Exchange (ETDEWEB)

Fingersh, Lee J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Loth, Eric [University of Virginia; Kaminski, Meghan [University of Virginia; Qin, Chao [University of Virginia; Griffith, D. Todd [Sandia National Laboratories

2017-06-09

A scaling methodology is described in the present paper for extreme-scale wind turbines (rated at 10 MW or more) that allow their sub-scale turbines to capture their key blade dynamics and aeroelastic deflections. For extreme-scale turbines, such deflections and dynamics can be substantial and are primarily driven by centrifugal, thrust and gravity forces as well as the net torque. Each of these are in turn a function of various wind conditions, including turbulence levels that cause shear, veer, and gust loads. The 13.2 MW rated SNL100-03 rotor design, having a blade length of 100-meters, is herein scaled to the CART3 wind turbine at NREL using 25% geometric scaling and blade mass and wind speed scaled by gravo-aeroelastic constraints. In order to mimic the ultralight structure on the advanced concept extreme-scale design the scaling results indicate that the gravo-aeroelastically scaled blades for the CART3 are be three times lighter and 25% longer than the current CART3 blades. A benefit of this scaling approach is that the scaled wind speeds needed for testing are reduced (in this case by a factor of two), allowing testing under extreme gust conditions to be much more easily achieved. Most importantly, this scaling approach can investigate extreme-scale concepts including dynamic behaviors and aeroelastic deflections (including flutter) at an extremely small fraction of the full-scale cost.

Risk Factors for Lower-Extremity Injuries Among Contemporary Dance Students.

Science.gov (United States)

van Seters, Christine; van Rijn, Rogier M; van Middelkoop, Marienke; Stubbe, Janine H

2017-10-10

To determine whether student characteristics, lower-extremity kinematics, and strength are risk factors for sustaining lower-extremity injuries in preprofessional contemporary dancers. Prospective cohort study. Codarts University of the Arts. Forty-five first-year students of Bachelor Dance and Bachelor Dance Teacher. At the beginning of the academic year, the injury history (only lower-extremity) and student characteristics (age, sex, educational program) were assessed using a questionnaire. Besides, lower-extremity kinematics [single-leg squat (SLS)], strength (countermovement jump) and height and weight (body mass index) were measured during a physical performance test. Substantial lower-extremity injuries during the academic year were defined as any problems leading to moderate or severe reductions in training volume or in performance, or complete inability to participate in dance at least once during follow-up as measured with the Oslo Sports Trauma Research Center (OSTRC) Questionnaire on Health Problems. Injuries were recorded on a monthly basis using a questionnaire. Analyses on leg-level were performed using generalized estimating equations to test the associations between substantial lower-extremity injuries and potential risk factors. The 1-year incidence of lower-extremity injuries was 82.2%. Of these, 51.4% was a substantial lower-extremity injury. Multivariate analyses identified that ankle dorsiflexion during the SLS (OR 1.25; 95% confidence interval, 1.03-1.52) was a risk factor for a substantial lower-extremity injury. The findings indicate that contemporary dance students are at high risk for lower-extremity injuries. Therefore, the identified risk factor (ankle dorsiflexion) should be considered for prevention purposes.

Exploring societal solidarity in the context of extreme prematurity.

Science.gov (United States)

Hendriks, Manya J; Bucher, Hans Ulrich; Klein, Sabine D; Streuli, Jürg C; Baumann-Hölzle, Ruth; Fauchère, Jean-Claude

2017-03-21

Extreme prematurity can result in long-term disabilities. Its impact on society is often not taken into account and deemed controversial. Our study examined attitudes of the Swiss population regarding extreme prematurity and people's perspectives regarding the question of solidarity with disabled people. We conducted a nationwide representative anonymous telephone survey with 1210 Swiss residents aged 18 years or older. We asked how people estimate their own personal solidarity, the solidarity of their social environment and the solidarity across the country with disabled persons. Spearman's correlation calculations were used to assess if a correlation exists between solidarity and setting financial limits to intensive care and between solidarity and withholding neonatal intensive care. According to 36.0% of the respondents intensive medical care should not be withheld from extremely preterm infants, even if their chances for an acceptable quality of life were poor. For 28.8%, intensive care should be withheld from these infants, and 26.9% held an intermediate position depending on the situation. A total of 31.5% were against setting a financial limit to treatment of extremely preterm newborns with an uncertain future quality of life, 34.2% were in favour and 26.9% were deliberating. A majority (88.8%) considered their solidarity toward disabled people as substantial; the solidarity of their personal environment and of the society at large was estimated as high by 79.1% and 48.6%, respectively. The Swiss population expressed a high level of solidarity which may alleviate some pressure on parents and health care providers in the decision-making process in neonatal intensive care units. In addition, there was no relationship between solidarity and people's willingness to pay for the care or withholding treatment of extremely preterm babies.

Hardware-in-the-Loop environment for testing and commissioning of space controllers; Hardware-in-the-Loop Umgebung zum Test und zur Inbetriebnahme von Raumreglern

Energy Technology Data Exchange (ETDEWEB)

Adlhoch, Alexander; Becker, Martin [Hochschule Biberach (Germany). Inst. fuer Gebaeude- und Energiesysteme

2012-07-01

The energy-efficient and optimal functioning of room controllers in terms of indoor air climates is influenced mainly by the control algorithm and the optimal adjustment of the parameters of controllers used in terms of space requirements. In the practical operation, deficits in the function or parameters of the controller are hardly or only with great effort metrological detectable, but have a significant impact on the energy consumption and / or the indoor climate comfort. In a hardware-in-the-loop (HIL) environment, room controllers can be examined in terms of the function under defined conditions, and different controllers can be evaluated comparatively. It is also possible to adjust the parameters of the controller before the commissioning. The HiL environment presented in the contribution under consideration consists of a model of the controlled system, a hardware coupler and a real controller to be tested. Among the spatial models, it can be selected from a plurality of different types of space which in turn can be assigned by means of different spatial parameters and environmental models. These combinations enable a replication of a test scenario corresponding to the later application. The hardware coupler provides a selection of physical inputs and outputs as well as interfaces to different bus systems (for example KNX, LON, EnOcean) for connecting different types of controllers. The construction and operation of a HIL test stand for space controller is presented based on first practical control tests. At this, the focus is on the suitability of this test environment for a variety of different controllers as well as development assistance and assistance for the adjustment of parameters. The HiL environments developed in the joint research project HiL RHK1 for the testing of space controllers, controllers for HVAC systems and refrigeration technology controllers have been developed so that the HiL environments can be coupled to a multi-HIL environment. This

Thermomechanical scoping calculations for the waste package environment tests

International Nuclear Information System (INIS)

Butkovich, T.R.; Yow, J.L. Jr.

1986-03-01

During the site characterization phase of the Nevada Nuclear Waste Storage Investigation Project, tests are planned to provide field information on the hydrological and thermomechanical environment. These results are needed for assessing performance of stored waste packages emplaced at depth in excavations in a rock mass. Scoping calculations were performed to provide information on displacements and stress levels attained around excavations in the rock mass from imposing a thermal load designed to simulate the heat produced by radioactive decay. In this way, approximate levels of stresses and displacements are available for choosing instrumentation type and sensitivity as well as providing indications for optimizing instrument emplacement during the test. 7 refs., 9 figs., 1 tab

Playing by the rules? Phenotypic adaptation to temperate environments in an American marsupial

Science.gov (United States)

Harrigan, Ryan J.; Wayne, Robert K.

2018-01-01

Phenotypic variation along environmental gradients can provide evidence suggesting local adaptation has shaped observed morphological disparities. These differences, in traits such as body and extremity size, as well as skin and coat pigmentation, may affect the overall fitness of individuals in their environments. The Virginia opossum (Didelphis virginiana) is a marsupial that shows phenotypic variation across its range, one that has recently expanded into temperate environments. It is unknown, however, whether the variation observed in the species fits adaptive ecogeographic patterns, or if phenotypic change is associated with any environmental factors. Using phenotypic measurements of over 300 museum specimens of Virginia opossum, collected throughout its distribution range, we applied regression analysis to determine if phenotypes change along a latitudinal gradient. Then, using predictors from remote-sensing databases and a random forest algorithm, we tested environmental models to find the most important variables driving the phenotypic variation. We found that despite the recent expansion into temperate environments, the phenotypic variation in the Virginia opossum follows a latitudinal gradient fitting three adaptive ecogeographic patterns codified under Bergmann’s, Allen’s and Gloger’s rules. Temperature seasonality was an important predictor of body size variation, with larger opossums occurring at high latitudes with more seasonal environments. Annual mean temperature predicted important variation in extremity size, with smaller extremities found in northern populations. Finally, we found that precipitation and temperature seasonality as well as low temperatures were strong environmental predictors of skin and coat pigmentation variation; darker opossums are distributed at low latitudes in warmer environments with higher precipitation seasonality. These results indicate that the adaptive mechanisms underlying the variation in body size, extremity

Playing by the rules? Phenotypic adaptation to temperate environments in an American marsupial

Directory of Open Access Journals (Sweden)

Sergio F. Nigenda-Morales

2018-03-01

Full Text Available Phenotypic variation along environmental gradients can provide evidence suggesting local adaptation has shaped observed morphological disparities. These differences, in traits such as body and extremity size, as well as skin and coat pigmentation, may affect the overall fitness of individuals in their environments. The Virginia opossum (Didelphis virginiana is a marsupial that shows phenotypic variation across its range, one that has recently expanded into temperate environments. It is unknown, however, whether the variation observed in the species fits adaptive ecogeographic patterns, or if phenotypic change is associated with any environmental factors. Using phenotypic measurements of over 300 museum specimens of Virginia opossum, collected throughout its distribution range, we applied regression analysis to determine if phenotypes change along a latitudinal gradient. Then, using predictors from remote-sensing databases and a random forest algorithm, we tested environmental models to find the most important variables driving the phenotypic variation. We found that despite the recent expansion into temperate environments, the phenotypic variation in the Virginia opossum follows a latitudinal gradient fitting three adaptive ecogeographic patterns codified under Bergmann’s, Allen’s and Gloger’s rules. Temperature seasonality was an important predictor of body size variation, with larger opossums occurring at high latitudes with more seasonal environments. Annual mean temperature predicted important variation in extremity size, with smaller extremities found in northern populations. Finally, we found that precipitation and temperature seasonality as well as low temperatures were strong environmental predictors of skin and coat pigmentation variation; darker opossums are distributed at low latitudes in warmer environments with higher precipitation seasonality. These results indicate that the adaptive mechanisms underlying the variation in

The test-retest reliability of anatomical co-ordinate axes definition for the quantification of lower extremity kinematics during running.

Science.gov (United States)

Sinclair, Jonathan; Taylor, Paul John; Greenhalgh, Andrew; Edmundson, Christopher James; Brooks, Darrell; Hobbs, Sarah Jane

2012-12-01

Three-dimensional (3-D) kinematic analyses are used widely in both sport and clinical examinations. However, this procedure depends on reliable palpation of anatomical landmarks and mal-positioning of markers between sessions may result in improperly defined segment co-ordinate system axes which will produce in-consistent joint rotations. This had led some to question the efficacy of this technique. The aim of the current investigation was to assess the reliability of the anatomical frame definition when quantifying 3-D kinematics of the lower extremities during running. Ten participants completed five successful running trials at 4.0 m·s(-1) ± 5%. 3-D angular joint kinematics parameters from the hip, knee and ankle were collected using an eight camera motion analysis system. Two static calibration trials were captured. The first (test) was conducted prior to the running trials following which anatomical landmarks were removed. The second was obtained following completion of the running trials where anatomical landmarks were re-positioned (retest). Paired samples t-tests were used to compare 3-D kinematic parameters quantified using the two static trials, and intraclass correlations were employed to examine the similarities between the sagittal, coronal and transverse plane waveforms. The results indicate that no significant (p>0.05) differences were found between test and retest 3-D kinematic parameters and strong (R(2)≥0.87) correlations were observed between test and retest waveforms. Based on the results obtained from this investigation, it appears that the anatomical co-ordinate axes of the lower extremities can be defined reliably thus confirming the efficacy of studies using this technique.

Development and Testing of the Healthy Work Environment Inventory: A Reliable Tool for Assessing Work Environment Health and Satisfaction.

Science.gov (United States)

Clark, Cynthia M; Sattler, Victoria P; Barbosa-Leiker, Celestina

2016-10-01

Fostering healthy work environments that enhance job satisfaction and reflect high levels of employee engagement and productivity is imperative for all organizations. This is especially true for health care organizations where unhealthy work conditions can lead to poor patient outcomes. A convenience sample of 520 nursing faculty and practice-based nurses in the United States participated in a study to test the psychometric properties of the Healthy Work Environment Inventory (HWEI). A factor analysis and other reliability analyses support the use of the HWEI as a valid and reliable instrument to measure perceptions of work environment health. The HWEI is a 20-item psychometrically sound instrument to measure perceptions of the health of the work environment. It may be completed either as an individual exercise or by all members of a team to compare perceptions of work environment health, to determine areas of strength and improvement, and to form the basis for interviewing. [J Nurs Educ. 2016;55(10):555-562.]. Copyright 2016, SLACK Incorporated.

The quality of visual information about the lower extremities influences visuomotor coordination during virtual obstacle negotiation.

Science.gov (United States)

Kim, Aram; Kretch, Kari S; Zhou, Zixuan; Finley, James M

2018-05-09

Successful negotiation of obstacles during walking relies on the integration of visual information about the environment with ongoing locomotor commands. When information about the body and environment are removed through occlusion of the lower visual field, individuals increase downward head pitch angle, reduce foot placement precision, and increase safety margins during crossing. However, whether these effects are mediated by loss of visual information about the lower extremities, the obstacle, or both remains to be seen. Here, we used a fully immersive, virtual obstacle negotiation task to investigate how visual information about the lower extremities is integrated with information about the environment to facilitate skillful obstacle negotiation. Participants stepped over virtual obstacles while walking on a treadmill with one of three types of visual feedback about the lower extremities: no feedback, end-point feedback, or a link-segment model. We found that absence of visual information about the lower extremities led to an increase in the variability of leading foot placement after crossing. The presence of a visual representation of the lower extremities promoted greater downward head pitch angle during the approach to and subsequent crossing of an obstacle. In addition, having greater downward head pitch was associated with closer placement of the trailing foot to the obstacle, further placement of the leading foot after the obstacle, and higher trailing foot clearance. These results demonstrate that the fidelity of visual information about the lower extremities influences both feed-forward and feedback aspects of visuomotor coordination during obstacle negotiation.

A Study of Mars Dust Environment Simulation at NASA Johnson Space Center Energy Systems Test Area Resource Conversion Test Facility

Science.gov (United States)

Chen, Yuan-Liang Albert

1999-01-01

The dust environment on Mars is planned to be simulated in a 20 foot thermal-vacuum chamber at the Johnson Space Center, Energy Systems Test Area Resource Conversion Test Facility in Houston, Texas. This vacuum chamber will be used to perform tests and study the interactions between the dust in Martian air and ISPP hardware. This project is to research, theorize, quantify, and document the Mars dust/wind environment needed for the 20 foot simulation chamber. This simulation work is to support the safety, endurance, and cost reduction of the hardware for the future missions. The Martian dust environment conditions is discussed. Two issues of Martian dust, (1) Dust Contamination related hazards, and (2) Dust Charging caused electrical hazards, are of our interest. The different methods of dust particles measurement are given. The design trade off and feasibility were studied. A glass bell jar system is used to evaluate various concepts for the Mars dust/wind environment simulation. It was observed that the external dust source injection is the best method to introduce the dust into the simulation system. The dust concentration of 30 Mg/M3 should be employed for preparing for the worst possible Martian atmosphere condition in the future. Two approaches thermal-panel shroud for the hardware conditioning are discussed. It is suggested the wind tunnel approach be used to study the dust charging characteristics then to be apply to the close-system cyclone approach. For the operation cost reduction purpose, a dehumidified ambient air could be used to replace the expensive CO2 mixture for some tests.

Digital mapping in extreme and remote environments

Science.gov (United States)

Andersson, Joel; Bauer, Tobias; Sarlus, Zimer; Zainy, Maher; Brethes, Anais

2017-04-01

During the last few years, Luleå University of Technology has performed a series of research projects in remote areas with extreme climatic conditions using digital mapping technologies. The majority of past and ongoing research projects focus on the arctic regions of the Fennoscandian Shield and Greenland but also on the Zagros fold-and-thrust belt in northern Iraq. Currently, we use the Midland Valley application FieldMove on iPad mini devices with ruggedized casings. As all projects have a strong focus on geological field work, harsh climatic conditions are a challenge not only for the geologists but also for the digital mapping hardware. In the arctic regions especially cold temperatures affect battery lifetime and performance of the screens. But also high temperatures are restricting digital mapping. From experience, a typical temperature range where digital mapping, using iPad tablets, is possible lies between -20 and +40 degrees. Furthermore, the remote character of field areas complicates access but also availability of electricity. By a combination of robust solar chargers and ruggedized batteries we are able to work entirely autarkical. Additionally, we are currently installing a drone system that allows us to map outcrops normally inaccessible because of safety reasons or time deficiency. The produced data will subsequently be taken into our Virtual Reality studio for interpretation and processing. There we will be able to work also with high resolution DEM data from Lidar scanning allowing us to interpret structural features such as post-glacial faults in areas that are otherwise only accessible by helicopter. By combining digital field mapping with drone technique and a Virtual Reality studio we are able to work in hardly accessible areas, improve safety during field work and increase efficiency substantially.

Detection of Stress Levels from Biosignals Measured in Virtual Reality Environments Using a Kernel-Based Extreme Learning Machine.

Science.gov (United States)

Cho, Dongrae; Ham, Jinsil; Oh, Jooyoung; Park, Jeanho; Kim, Sayup; Lee, Nak-Kyu; Lee, Boreom

2017-10-24

Virtual reality (VR) is a computer technique that creates an artificial environment composed of realistic images, sounds, and other sensations. Many researchers have used VR devices to generate various stimuli, and have utilized them to perform experiments or to provide treatment. In this study, the participants performed mental tasks using a VR device while physiological signals were measured: a photoplethysmogram (PPG), electrodermal activity (EDA), and skin temperature (SKT). In general, stress is an important factor that can influence the autonomic nervous system (ANS). Heart-rate variability (HRV) is known to be related to ANS activity, so we used an HRV derived from the PPG peak interval. In addition, the peak characteristics of the skin conductance (SC) from EDA and SKT variation can also reflect ANS activity; we utilized them as well. Then, we applied a kernel-based extreme-learning machine (K-ELM) to correctly classify the stress levels induced by the VR task to reflect five different levels of stress situations: baseline, mild stress, moderate stress, severe stress, and recovery. Twelve healthy subjects voluntarily participated in the study. Three physiological signals were measured in stress environment generated by VR device. As a result, the average classification accuracy was over 95% using K-ELM and the integrated feature (IT = HRV + SC + SKT). In addition, the proposed algorithm can embed a microcontroller chip since K-ELM algorithm have very short computation time. Therefore, a compact wearable device classifying stress levels using physiological signals can be developed.

Stigma associated with sexually transmissible infection testing in an online testing environment: examining the perspectives of youth in Vancouver, Canada.

Science.gov (United States)

Karamouzian, Mohammad; Knight, Rod; Davis, Wendy M; Gilbert, Mark; Shoveller, Jean

2018-02-01

Background Online sexually transmissible infection (STI) testing is increasingly available and has shown promising results across different settings. However, evidence on how stigma associated with STI testing may be experienced by youth in the context of these online services is limited. A convenience sample of 71 youth (aged 15-24 years) both male and female was engaged through online and offline recruitment strategies in Vancouver, Canada. Through semistructured and exploratory interviews, participants were asked about their perceptions of stigma associated with STI testing in an online testing environment. Data were analysed using a thematic analysis approach. Youth came from a diverse set of sociodemographic backgrounds and most (n=46, 65%) had previously accessed STI testing in clinic-based settings. Participants' perceptions pointed to the benefits of online testing for reducing the external stigma despite the potential persistence of internalised stigma. Notions of hegemonic masculinity and emphasised femininity were also present in the participants' descriptions of the role of gender in accessing online STI testing. Online STI testing could potentially ameliorate the experiences of participants in regards to the stigma associated with STI testing; however, participants' internalised feelings of shame and stigma around testing for STI may continue to persist. Our findings underscore the need to revisit and re-evaluate existing STI testing services to provide less anxiety-inducing testing environments for youth.

Investigating NARCCAP Precipitation Extremes via Bivariate Extreme Value Theory (Invited)

Science.gov (United States)

Weller, G. B.; Cooley, D. S.; Sain, S. R.; Bukovsky, M. S.; Mearns, L. O.

2013-12-01

We introduce methodology from statistical extreme value theory to examine the ability of reanalysis-drive regional climate models to simulate past daily precipitation extremes. Going beyond a comparison of summary statistics such as 20-year return values, we study whether the most extreme precipitation events produced by climate model simulations exhibit correspondence to the most extreme events seen in observational records. The extent of this correspondence is formulated via the statistical concept of tail dependence. We examine several case studies of extreme precipitation events simulated by the six models of the North American Regional Climate Change Assessment Program (NARCCAP) driven by NCEP reanalysis. It is found that the NARCCAP models generally reproduce daily winter precipitation extremes along the Pacific coast quite well; in contrast, simulation of past daily summer precipitation extremes in a central US region is poor. Some differences in the strength of extremal correspondence are seen in the central region between models which employ spectral nudging and those which do not. We demonstrate how these techniques may be used to draw a link between extreme precipitation events and large-scale atmospheric drivers, as well as to downscale extreme precipitation simulated by a future run of a regional climate model. Specifically, we examine potential future changes in the nature of extreme precipitation along the Pacific coast produced by the pineapple express (PE) phenomenon. A link between extreme precipitation events and a "PE Index" derived from North Pacific sea-surface pressure fields is found. This link is used to study PE-influenced extreme precipitation produced by a future-scenario climate model run.

Plutonium in the desert environment of the Nevada Test Site and the Tonopah Test Range

International Nuclear Information System (INIS)

Romney, E.M.; Essington, E.H.; Fowler, E.B.; Tamura, T.; Gilbert, R.O.

1987-01-01

Several safety shot tests were conducted in the desert environment of the Nevada Test Site and the Tonopah Test Range during the period 1955 to 1963. Follow-up studies were conducted in fallout areas resulting from these tests to investigate the distribution in soils and the availability to animals and plants of plutonium (and americium) after residence times of 10 to 20 years. Soil profile studies disclosed that more than 95% of the plutonium (and americium) dispersed as fallout to the environment had remained in the top 5 cm of soil in undisturbed areas. Significant amounts had been redistributed into blow-sand mounds formed underneath clumps of vegetation. That redistribution should be expected because the contaminant was associated primarily with the coarse silt and fine sand particle size fractions. Resuspension factors were calculated that varied from 9.1 x 10 -11 m -1 to 5.4 x 10 -9 m -1 with geometric mean and arithmetic averages of 2.9 x 10 -10 m -1 and 6.8 x 10 -10 m -1 , respectively; however, the plutonium essentially remained in place when the soil surface was left undisturbed. Vegetation in the fallout areas was contaminated primarily by resuspendable material deposited on the surface of plant foliage; plutonium concentration ratios ranged from 10 -3 to 10 0 . Carcass samples of small vertebrate animals collected from fallout areas contained only trace amounts of plutonium compared to the environmental exposure levels. Furthermore, only trace amounts of plutonium (and americium) were found in muscle and organ tissues of grazing cattle during a 3-year on-site residence experiment. 36 references, 4 figures

Force Myography for Monitoring Grasping in Individuals with Stroke with Mild to Moderate Upper-Extremity Impairments: A Preliminary Investigation in a Controlled Environment

Directory of Open Access Journals (Sweden)

Gautam P. Sadarangani

2017-07-01

% the size of the testing set resulted in 91.7% (σ = 3.9% accuracy for participants with stroke and 95.6% (σ = 1.6% for healthy participants. These promising results indicate that FMG may be feasible for monitoring grasping, in the presence of upper-extremity movements, in individuals with stroke with mild to moderate upper-extremity impairments.

Two spatial scales in a bleaching event: Corals from the mildest and the most extreme thermal environments escape mortality

KAUST Repository

Pineda, Jesús

2013-07-28

In summer 2010, a bleaching event decimated the abundant reef flat coral Stylophora pistillata in some areas of the central Red Sea, where a series of coral reefs 100–300 m wide by several kilometers long extends from the coastline to about 20 km offshore. Mortality of corals along the exposed and protected sides of inner (inshore) and mid and outer (offshore) reefs and in situ and satellite sea surface temperatures (SSTs) revealed that the variability in the mortality event corresponded to two spatial scales of temperature variability: 300 m across the reef flat and 20 km across a series of reefs. However, the relationship between coral mortality and habitat thermal severity was opposite at the two scales. SSTs in summer 2010 were similar or increased modestly (0.5°C) in the outer and mid reefs relative to 2009. In the inner reef, 2010 temperatures were 1.4°C above the 2009 seasonal maximum for several weeks. We detected little or no coral mortality in mid and outer reefs. In the inner reef, mortality depended on exposure. Within the inner reef, mortality was modest on the protected (shoreward) side, the most severe thermal environment, with highest overall mean and maximum temperatures. In contrast, acute mortality was observed in the exposed (seaward) side, where temperature fluctuations and upper water temperature values were relatively less extreme. Refuges to thermally induced coral bleaching may include sites where extreme, high-frequency thermal variability may select for coral holobionts preadapted to, and physiologically condition corals to withstand, regional increases in water temperature.

USB environment measurements based on full-scale static engine ground tests

Science.gov (United States)

Sussman, M. B.; Harkonen, D. L.; Reed, J. B.

1976-01-01

Flow turning parameters, static pressures, surface temperatures, surface fluctuating pressures and acceleration levels were measured in the environment of a full-scale upper surface blowing (USB) propulsive lift test configuration. The test components included a flightworthy CF6-50D engine, nacelle, and USB flap assembly utilized in conjunction with ground verification testing of the USAF YC-14 Advanced Medium STOL Transport propulsion system. Results, based on a preliminary analysis of the data, generally show reasonable agreement with predicted levels based on model data. However, additional detailed analysis is required to confirm the preliminary evaluation, to help delineate certain discrepancies with model data, and to establish a basis for future flight test comparisons.

Testing effective quantum gravity with gravitational waves from extreme mass ratio inspirals

International Nuclear Information System (INIS)

Yunes, N; Sopuerta, C F

2010-01-01

Testing deviation of GR is one of the main goals of the proposed Laser Interferometer Space Antenna. For the first time, we consistently compute the generation of gravitational waves from extreme-mass ratio inspirals (stellar compact objects into supermassive black holes) in a well-motivated alternative theory of gravity, that to date remains weakly constrained by double binary pulsar observations. The theory we concentrate on is Chern-Simons (CS) modified gravity, a 4-D, effective theory that is motivated both from string theory and loop-quantum gravity, and which enhances the Einstein-Hilbert action through the addition of a dynamical scalar field and the parity-violating Pontryagin density. We show that although point particles continue to follow geodesics in the modified theory, the background about which they inspiral is a modification to the Kerr metric, which imprints a CS correction on the gravitational waves emitted. CS modified gravitational waves are sufficiently different from the General Relativistic expectation that they lead to significant dephasing after 3 weeks of evolution, but such dephasing will probably not prevent detection of these signals, but instead lead to a systematic error in the determination of parameters. We end with a study of radiation-reaction in the modified theory and show that, to leading-order, energy-momentum emission is not CS modified, except possibly for the subdominant effect of scalar-field emission. The inclusion of radiation-reaction will allow for tests of CS modified gravity with space-borne detectors that might be two orders of magnitude larger than current binary pulsar bounds.

Mechanisms of interfacial reactivity in near surface and extreme environments

Energy Technology Data Exchange (ETDEWEB)

Chen, Ying [Univ. of California, San Diego, CA (United States); Balaska, Eric [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weare, John [Univ. of California, San Diego, CA (United States); Fulton, John [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bogatko, Stuart [Univ. of California, San Diego, CA (United States); Balasubramanian, Mahalingam [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cauet, Emilie [Univ. of California, San Diego, CA (United States); Kerisit, Sebastien [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Felmy, Andrew [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schenter, Gregory [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weare, Jonathan [U of Chicago

2017-01-09

+, Co²⁺, Mn²⁺, Fe³⁺, Cr³⁺. Calculations on these systems are demanding because of their open electronic shells, and high ionic charge. Principal Investigator: Professor John Weare (University of California, San Diego) The prediction of the interactions of geochemical fluids with minerals, nanoparticles, and colloids under extreme near surface conditions of temperature (T) and pressure (P) is a grand challenge research need in geosciences (U.S. DOE 2007, Basic Research Needs for Geosciences: Facilitating the 21st Energy Systems.). To evaluate the impact of these processes on energy production and management strategies it is necessary to have a high level of understanding of the interaction between complex natural fluids and mineral formations. This program emphasizes 1st principle parameter free simulations of complex chemical processes in solutions, in the mineral phase, and in the interfaces between these phases The development of new computational tools (with emphasis on oxide materials and reaction dynamics) tailored to treat wide range of conditions and time scales experienced in such geochemical applications is has been developed. Because of the sensitivity of the interaction in these systems to electronic structure and local bonding environments, and of the need to describe bond breaking/formation, our simulations are based on interactions calculated at the electronic structure level (ab-initio molecular dynamics, AIMD). The progress in the computational aspects of program may be summarized in terms of the following themes (objectives); Development of efficient parameter free dynamical simulation technology based on 1st principles force and energy calculations especially adapted for geochemical applications (e.g., mineral, interfaces and aqueous solutions) (continuing program); Calculation of the dynamics of water structure of in the surface-water interface of transition metal oxides and oxihydroxides; and

Altered lower extremity joint mechanics occur during the star excursion balance test and single leg hop after ACL-reconstruction in a collegiate athlete.

Science.gov (United States)

Samaan, Michael A; Ringleb, Stacie I; Bawab, Sebastian Y; Greska, Eric K; Weinhandl, Joshua T

2018-03-01

The effects of ACL-reconstruction on lower extremity joint mechanics during performance of the Star Excursion Balance Test (SEBT) and Single Leg Hop (SLH) are limited. The purpose of this study was to determine if altered lower extremity mechanics occur during the SEBT and SLH after ACL-reconstruction. One female Division I collegiate athlete performed the SEBT and SLH tasks, bilaterally, both before ACL injury and 27 months after ACL-reconstruction. Maximal reach, hop distances, lower extremity joint kinematics and moments were compared between both time points. Musculoskeletal simulations were used to assess muscle force production during the SEBT and SLH at both time points. Compared to the pre-injury time point, SEBT reach distances were similar in both limbs after ACL-reconstruction except for the max anterior reach distance in the ipsilateral limb. The athlete demonstrated similar hop distances, bilaterally, after ACL-reconstruction compared to the pre-injury time point. Despite normal functional performance during the SEBT and SLH, the athlete exhibited altered lower extremity joint mechanics during both of these tasks. These results suggest that measuring the maximal reach and hop distances for these tasks, in combination with an analysis of the lower extremity joint mechanics that occur after ACL-reconstruction, may help clinicians and researchers to better understand the effects of ACL-reconstruction on the neuromuscular system during the SEBT and SLH.

Modeling the distribution of extreme share return in Malaysia using Generalized Extreme Value (GEV) distribution

Science.gov (United States)

Hasan, Husna; Radi, Noor Fadhilah Ahmad; Kassim, Suraiya

2012-05-01

Extreme share return in Malaysia is studied. The monthly, quarterly, half yearly and yearly maximum returns are fitted to the Generalized Extreme Value (GEV) distribution. The Augmented Dickey Fuller (ADF) and Phillips Perron (PP) tests are performed to test for stationarity, while Mann-Kendall (MK) test is for the presence of monotonic trend. Maximum Likelihood Estimation (MLE) is used to estimate the parameter while L-moments estimate (LMOM) is used to initialize the MLE optimization routine for the stationary model. Likelihood ratio test is performed to determine the best model. Sherman's goodness of fit test is used to assess the quality of convergence of the GEV distribution by these monthly, quarterly, half yearly and yearly maximum. Returns levels are then estimated for prediction and planning purposes. The results show all maximum returns for all selection periods are stationary. The Mann-Kendall test indicates the existence of trend. Thus, we ought to model for non-stationary model too. Model 2, where the location parameter is increasing with time is the best for all selection intervals. Sherman's goodness of fit test shows that monthly, quarterly, half yearly and yearly maximum converge to the GEV distribution. From the results, it seems reasonable to conclude that yearly maximum is better for the convergence to the GEV distribution especially if longer records are available. Return level estimates, which is the return level (in this study return amount) that is expected to be exceeded, an average, once every t time periods starts to appear in the confidence interval of T = 50 for quarterly, half yearly and yearly maximum.

Extreme Radiation Hardness and Space Qualification of AlGaN Optoelectronic Devices

International Nuclear Information System (INIS)

Sun, Ke-Xun; MacNeil, Lawrence; Balakrishnan, Kathik; Hultgren, Eric; Goebel, John; Bilenko, Yuri; Yang, Jinwei; Sun, Wenhong; Shatalov, Max; Hu, Xuhong; Gaska, Remis

2010-01-01

Unprecedented radiation hardness and environment robustness are required in the new generation of high energy density physics (HEDP) experiments and deep space exploration. National Ignition Facility (NIF) break-even shots will have a neutron yield of 10 15 or higher. The Europa Jupiter System Mission (EJSM) mission instruments will be irradiated with a total fluence of 10 12 protons/cm 2 during the space journey. In addition, large temperature variations and mechanical shocks are expected in these applications under extreme conditions. Hefty radiation and thermal shields are required for Si and GaAs based electronics and optoelectronics devices. However, for direct illumination and imaging applications, shielding is not a viable option. It is an urgent task to search for new semiconductor technologies and to develop radiation hard and environmentally robust optoelectronic devices. We will report on our latest systematic experimental studies on radiation hardness and space qualifications of AlGaN optoelectronic devices: Deep UV Light Emitting Diodes (DUV LEDs) and solarblind UV Photodiodes (PDs). For custom designed AlGaN DUV LEDs with a central emission wavelength of 255 nm, we have demonstrated its extreme radiation hardness up to 2 x 10 12 protons/cm 2 with 63.9 MeV proton beams. We have demonstrated an operation lifetime of over 26,000 hours in a nitrogen rich environment, and 23,000 hours of operation in vacuum without significant power drop and spectral shift. The DUV LEDs with multiple packaging styles have passed stringent space qualifications with 14 g random vibrations, and 21 cycles of 100K temperature cycles. The driving voltage, current, emission spectra and optical power (V-I-P) operation characteristics exhibited no significant changes after the space environmental tests. The DUV LEDs will be used for photoelectric charge management in space flights. For custom designed AlGaN UV photodiodes with a central response wavelength of 255 nm, we have

Standard test method for determining a threshold stress intensity factor for environment-assisted cracking of metallic materials

CERN Document Server

American Society for Testing and Materials. Philadelphia

2003-01-01

1.1 This test method covers the determination of the environment-assisted cracking threshold stress intensity factor parameters, KIEAC and KEAC, for metallic materials from constant-force testing of fatigue precracked beam or compact fracture specimens and from constant-displacement testing of fatigue precracked bolt-load compact fracture specimens. 1.2 This test method is applicable to environment-assisted cracking in aqueous or other aggressive environments. 1.3 Materials that can be tested by this test method are not limited by thickness or by strength as long as specimens are of sufficient thickness and planar size to meet the size requirements of this test method. 1.4 A range of specimen sizes with proportional planar dimensions is provided, but size may be variable and adjusted for yield strength and applied force. Specimen thickness is a variable independent of planar size. 1.5 Specimen configurations other than those contained in this test method may be used, provided that well-established stress ...

Extreme values, regular variation and point processes

CERN Document Server

Resnick, Sidney I

1987-01-01

Extremes Values, Regular Variation and Point Processes is a readable and efficient account of the fundamental mathematical and stochastic process techniques needed to study the behavior of extreme values of phenomena based on independent and identically distributed random variables and vectors It presents a coherent treatment of the distributional and sample path fundamental properties of extremes and records It emphasizes the core primacy of three topics necessary for understanding extremes the analytical theory of regularly varying functions; the probabilistic theory of point processes and random measures; and the link to asymptotic distribution approximations provided by the theory of weak convergence of probability measures in metric spaces The book is self-contained and requires an introductory measure-theoretic course in probability as a prerequisite Almost all sections have an extensive list of exercises which extend developments in the text, offer alternate approaches, test mastery and provide for enj...

OBSERVER RATING VERSUS THREE-DIMENSIONAL MOTION ANALYSIS OF LOWER EXTREMITY KINEMATICS DURING FUNCTIONAL SCREENING TESTS: A SYSTEMATIC REVIEW.

Science.gov (United States)

Maclachlan, Liam; White, Steven G; Reid, Duncan

2015-08-01

Functional assessments are conducted in both clinical and athletic settings in an attempt to identify those individuals who exhibit movement patterns that may increase their risk of non-contact injury. In place of highly sophisticated three-dimensional motion analysis, functional testing can be completed through observation. To evaluate the validity of movement observation assessments by summarizing the results of articles comparing human observation in real-time or video play-back and three-dimensional motion analysis of lower extremity kinematics during functional screening tests. Systematic review. A computerized systematic search was conducted through Medline, SPORTSdiscus, Scopus, Cinhal, and Cochrane health databases between February and April of 2014. Validity studies comparing human observation (real-time or video play-back) to three-dimensional motion analysis of functional tasks were selected. Only studies comprising uninjured, healthy subjects conducting lower extremity functional assessments were appropriate for review. Eligible observers were certified health practitioners or qualified members of sports and athletic training teams that conduct athlete screening. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) was used to appraise the literature. Results are presented in terms of functional tasks. Six studies met the inclusion criteria. Across these studies, two-legged squats, single-leg squats, drop-jumps, and running and cutting manoeuvres were the functional tasks analysed. When compared to three-dimensional motion analysis, observer ratings of lower extremity kinematics, such as knee position in relation to the foot, demonstrated mixed results. Single-leg squats achieved target sensitivity values (≥ 80%) but not specificity values (≥ 50%>%). Drop-jump task agreement ranged from poor ( 80%). Two-legged squats achieved 88% sensitivity and 85% specificity. Mean underestimations as large as 198 (peak knee flexion) were found in

A combination test for detection of gene-environment interaction in cohort studies.

Science.gov (United States)

Coombes, Brandon; Basu, Saonli; McGue, Matt

2017-07-01

Identifying gene-environment (G-E) interactions can contribute to a better understanding of disease etiology, which may help researchers develop disease prevention strategies and interventions. One big criticism of studying G-E interaction is the lack of power due to sample size. Studies often restrict the interaction search to the top few hundred hits from a genome-wide association study or focus on potential candidate genes. In this paper, we test interactions between a candidate gene and an environmental factor to improve power by analyzing multiple variants within a gene. We extend recently developed score statistic based genetic association testing approaches to the G-E interaction testing problem. We also propose tests for interaction using gene-based summary measures that pool variants together. Although it has recently been shown that these summary measures can be biased and may lead to inflated type I error, we show that under several realistic scenarios, we can still provide valid tests of interaction. These tests use significantly less degrees of freedom and thus can have much higher power to detect interaction. Additionally, we demonstrate that the iSeq-aSum-min test, which combines a gene-based summary measure test, iSeq-aSum-G, and an interaction-based summary measure test, iSeq-aSum-I, provides a powerful alternative to test G-E interaction. We demonstrate the performance of these approaches using simulation studies and illustrate their performance to study interaction between the SNPs in several candidate genes and family climate environment on alcohol consumption using the Minnesota Center for Twin and Family Research dataset. © 2017 WILEY PERIODICALS, INC.

New grid based test bed environment for carrying out ad-hoc networking experiments

CSIR Research Space (South Africa)

Johnson, D

2006-09-01

Full Text Available and the third is to do analysis on a real test bed network which has implemented the ad-hoc networking protocol. This paper concerns the third option. Most researchers who have done work on test bed environments have used either indoor Wifi inter-office links...

Observed changes in seasonal heat waves and warm temperature extremes in the Romanian Carpathians

Science.gov (United States)

Micu, Dana; Birsan, Marius-Victor; Dumitrescu, Alexandru; Cheval, Sorin

2015-04-01

Extreme high temperature have a large impact on environment and human activities, especially in high elevation areas particularly sensitive to the recent climate warming. The climate of the Romanian Carpathians became warmer particularly in winter, spring and summer, exibiting a significant increasing frequency of warm extremes. The paper investigates the seasonal changes in the frequency, duration and intensity of heat waves in relation to the shifts in the daily distribution of maximum temperatures over a 50-year period of meteorological observations (1961-2010). The paper uses the heat wave definition recommended by the Expert Team on Climate Change Detection and Indices (ETCCDI) and exploits the gridded daily dataset of maximum temperature at 0.1° resolution (~10 km) developed in the framework of the CarpatClim project (www.carpatclim.eu). The seasonal changes in heat waves behavior were identified using the Mann-Kendall non-parametric trend test. The results suggest an increase in heat wave frequency and a lengthening of intervals affected by warm temperature extremes all over the study region, which are explained by the shifts in the upper (extreme) tail of the daily maximum temperature distribution in most seasons. The trends are consistent across the region and are well correlated to the positive phases of the East Atlantic Oscillation. Our results are in good agreement with the previous temperature-related studies concerning the Carpathian region. This study was realized within the framework of the project GENCLIM, financed by UEFISCDI, code PN-II 151/2014.

UAS-NAS Integrated Human in the Loop: Test Environment Report

Science.gov (United States)

Murphy, Jim; Otto, Neil; Jovic, Srba

2015-01-01

The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration in the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability (SSI), Human Systems Integration (HSI), and Communication to support reducing the barriers of UAS access to the NAS. This research was broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Sense and Avoid (SAA) performance standards, command and control performance standards, and human systems integration. The focus of the Test Infrastructure theme was to enable development and validation of airspace integration procedures and performance standards, including the execution of integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project developed an adaptable, scalable, and schedulable relevant test environment incorporating live, virtual, and constructive elements capable of validating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project planned to conduct three integrated events: a Human-in-the-Loop simulation and two Flight Test series that integrated key concepts, technologies and/or procedures in a relevant air traffic environment. Each of

Measurement and Analysis of the Extreme Physical Shock Environment Experienced by Crane-Mounted Radiation Detection Systems.

Energy Technology Data Exchange (ETDEWEB)

Boyd, M [Texas A & M Univ., College Station, TX (United States); Erchinger, J [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Marianno, C [Texas A & M Univ., College Station, TX (United States); Kallenbach, Gene A. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Grypp, M [US Dept. of the Navy

2017-09-01

Potentially, radiation detectors at ports of entry could be mounted on container gantry crane spreaders to monitor cargo containers entering and leaving the country. These detectors would have to withstand the extreme physical environment experienced by these spreaders during normal operations. Physical shock data from the gable ends of a spreader were recorded during the loading and unloading of a cargo ship with two Lansmont SAVER 9X30 units (with padding) and two PCB Piezotronics model 340A50 accelerometers (hard mounted). Physical shocks in the form of rapid acceleration were observed in all accelerometer units with values ranging from 0.20 g’s to 199.99 g’s. The majority of the shocks for all the Lansmont and PCB accelerometers were below 50 g’s. The Lansmont recorded mean shocks of 21.83 ± 13.62 g’s and 24.78 ± 11.49 g’s while the PCB accelerometers experienced mean shocks of 34.39 ± 25.51 g’s and 41.77 ± 22.68 g’s for the landside and waterside units, respectively. Encased detector units with external padding should be designed to withstand at least 200 g’s of acceleration without padding and typical shocks of 30 g’s with padding for mounting on a spreader.

Containment bellows testing under extreme loads

International Nuclear Information System (INIS)

Splezter, B.L.; Lambert, L.D.; Parks, M.B.

1993-01-01

Sandia National Laboratories (SNL) is conducting several research programs to help develop validated methods for the prediction of the ultimate pressure capacity, at elevated temperatures, of light water reactor (LWR) containment structures. To help understand the ultimate pressure of the entire containment pressure boundary, each component must be evaluated. The containment pressure boundary consists of the containment shell and many access, piping, and electrical penetrations. The focus of the current research program is to study the ultimate behavior of flexible metal bellows that are used at piping penetrations. Bellows are commonly used at piping penetrations in steel containments; however, they have very few applications in concrete (reinforced or prestressed) containments. The purpose of piping bellows is to provide a soft connection between the containment shell and the pipe are attached while maintaining the containment pressure boundary. In this way, piping loads caused by differential movement between the piping and the containment shell are minimized. SNL is conducting a test program to determine the leaktight capacity of containment bellows when subjected to postulated severe accident conditions. If the test results indicate that containment bellows could be a possible failure mode of the containment pressure boundary, then methods will be developed to predict the deformation, pressure, and temperature conditions that would likely cause a bellows failure. Results from the test program would be used to validate the prediction methods. This paper provides a description of the use and design of bellows in containment piping penetrations, the types of possible bellows loadings during a severe accident, and an overview of the test program, including available test results at the time of writing

Silicified virus-like nanoparticles in an extreme thermal environment: implications for the preservation of viruses in the geological record.

Science.gov (United States)

Peng, X; Xu, H; Jones, B; Chen, S; Zhou, H

2013-11-01

Biofilms that grow around Gumingquan hot spring (T = 71 °C, pH = 9.2) in the Rehai geothermal area, Tengchong, China, are formed of various cyanobacteria, Firmicutes, Aquificae, Thermodesulfobacteria, Desulfurococcales, and Thermoproteales. Silicified virus-like nanoparticles, 40-200 nm in diameter, are common inside the microbial cells and the extracellular polymeric substances around the cells. These nanoparticles, which are formed of a core encased by a silica cortex, are morphologically akin to known viruses and directly comparable to silicified virus-like particles that were produced in biofilms cultured in the laboratory. The information obtained from examination of the natural and laboratory-produced samples suggests that viruses can be preserved by silicification, especially while they are still encased in their host cells. These results expand our views of virus-host mineral interaction in extreme thermal environments and imply that viruses can be potentially preserved and identified in the geological record. © 2013 John Wiley & Sons Ltd.

Extreme Geohazards: Reducing the Disaster Risk and Increasing Resilience

Science.gov (United States)

Plag, Hans-Peter; Stein, Seth; Brocklebank, Sean; Jules-Plag, Shelley; Marsh, Stuart; Campus, Paola

2013-04-01

Extreme geohazards have the potential to escalate the global sustainability crisis and put us close to the boundaries of the safe operating space for humanity. Exposure of human assets to geohazards has increased dramatically in recent decades, and the sensitivity of the built environment and the embedded socio-economic fabric have changed. We are putting the urban environment, including megacities, in harm's way. Paradoxically, innovation during recent decades, in particular, urban innovation, has increased the disaster risk and coupled this risk to the sustainability crisis. Only more innovation can reduce disaster risk and lead us out of the sustainability crisis. Extreme geohazards (volcanic eruptions, earthquakes, tsunamis) that occurred regularly throughout the last few millennia mostly did not cause major disasters because population density was low and the built environment was not sprawling into hazardous areas to the same extent as today. Similar extreme events today would cause unparalleled damage on a global scale and could worsen the sustainability crisis. Simulation of these extreme hazards under present conditions can help to assess the disaster risk. The Geohazards Community of Practice of the Group on Earth Observations (GEO) with support from the European Science Foundation is preparing a white paper assessing the contemporary disaster risks associated with extreme geohazards and developing a vision for science and society to engage in deliberations addressing this risk (see http://www.geohazcop.org/projects/extgeowp). Risk awareness and monitoring is highly uneven across the world, and this creates two kinds of problems. Firstly, potential hazards are much more closely monitored in wealthy countries than in the developing world. But the largest hazards are global in nature, and it is critical to get as much forewarning as possible to develop an effective response. The disasters and near-misses of the past show that adherence to scientific

Probability distribution of extreme share returns in Malaysia

Science.gov (United States)

Zin, Wan Zawiah Wan; Safari, Muhammad Aslam Mohd; Jaaman, Saiful Hafizah; Yie, Wendy Ling Shin

2014-09-01

The objective of this study is to investigate the suitable probability distribution to model the extreme share returns in Malaysia. To achieve this, weekly and monthly maximum daily share returns are derived from share prices data obtained from Bursa Malaysia over the period of 2000 to 2012. The study starts with summary statistics of the data which will provide a clue on the likely candidates for the best fitting distribution. Next, the suitability of six extreme value distributions, namely the Gumbel, Generalized Extreme Value (GEV), Generalized Logistic (GLO) and Generalized Pareto (GPA), the Lognormal (GNO) and the Pearson (PE3) distributions are evaluated. The method of L-moments is used in parameter estimation. Based on several goodness of fit tests and L-moment diagram test, the Generalized Pareto distribution and the Pearson distribution are found to be the best fitted distribution to represent the weekly and monthly maximum share returns in Malaysia stock market during the studied period, respectively.

77 FR 48527 - National Customs Automation Program (NCAP) Test Concerning Automated Commercial Environment (ACE...

Science.gov (United States)

2012-08-14

... National Customs Automation Program (NCAP) test concerning the simplified entry functionality in the... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection National Customs Automation Program (NCAP) Test Concerning Automated Commercial Environment (ACE) Simplified Entry: Modification of...

Biodegradation of petroleum hydrocarbons in hypersaline environments

Directory of Open Access Journals (Sweden)

Luiz Fernando Martins

2012-09-01

Full Text Available Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review.

Evaluation of COTS Electronic Parts for Extreme Temperature Use in NASA Missions

Science.gov (United States)

Patterson, Richard L.; Hammoud, Ahmad; Elbuluk, Malik

2008-01-01

Electronic systems capable of extreme temperature operation are required for many future NASA space exploration missions where it is desirable to have smaller, lighter, and less expensive spacecraft and probes. Presently, spacecraft on-board electronics are maintained at about room temperature by use of thermal control systems. An Extreme Temperature Electronics Program at the NASA Glenn Research Center focuses on development of electronics suitable for space exploration missions. The effects of exposure to extreme temperatures and thermal cycling are being investigated for commercial-off-the-shelf components as well as for components specially developed for harsh environments. An overview of this program along with selected data is presented.

QUEST/Ada (query utility environment for software testing of Ada: The development of a program analysis environment for Ada, task 1, phase 3

Science.gov (United States)

Brown, David B.

1991-01-01

The results of research and development efforts of the first six months of Task 1, Phase 3 of the project are presented. The goals of Phase 3 are: (1) to further refine the rule base and complete the comparative rule base evaluation; (2) to implement and evaluate a concurrency testing prototype; (3) to convert the complete (unit-level and concurrency) testing prototype to a workstation environment; and (4) to provide a prototype development document to facilitate the transfer of research technology to a working environment. These goals were partially met and the results are summarized.

Mandelbrot's Extremism

NARCIS (Netherlands)

Beirlant, J.; Schoutens, W.; Segers, J.J.J.

2004-01-01

In the sixties Mandelbrot already showed that extreme price swings are more likely than some of us think or incorporate in our models.A modern toolbox for analyzing such rare events can be found in the field of extreme value theory.At the core of extreme value theory lies the modelling of maxima

Regional estimation of extreme suspended sediment concentrations using watershed characteristics

Science.gov (United States)

Tramblay, Yves; Ouarda, Taha B. M. J.; St-Hilaire, André; Poulin, Jimmy

2010-01-01

SummaryThe number of stations monitoring daily suspended sediment concentration (SSC) has been decreasing since the 1980s in North America while suspended sediment is considered as a key variable for water quality. The objective of this study is to test the feasibility of regionalising extreme SSC, i.e. estimating SSC extremes values for ungauged basins. Annual maximum SSC for 72 rivers in Canada and USA were modelled with probability distributions in order to estimate quantiles corresponding to different return periods. Regionalisation techniques, originally developed for flood prediction in ungauged basins, were tested using the climatic, topographic, land cover and soils attributes of the watersheds. Two approaches were compared, using either physiographic characteristics or seasonality of extreme SSC to delineate the regions. Multiple regression models to estimate SSC quantiles as a function of watershed characteristics were built in each region, and compared to a global model including all sites. Regional estimates of SSC quantiles were compared with the local values. Results show that regional estimation of extreme SSC is more efficient than a global regression model including all sites. Groups/regions of stations have been identified, using either the watershed characteristics or the seasonality of occurrence for extreme SSC values providing a method to better describe the extreme events of SSC. The most important variables for predicting extreme SSC are the percentage of clay in the soils, precipitation intensity and forest cover.

Ecological-economical approach to assessment of environment state at the Semipalatinsk test site

International Nuclear Information System (INIS)

Chugunova, N.S.; Balykbaeva, S.Y.

2002-01-01

The paper presents methods used for ecological-economical assessment of the environment condition at the former Semipalatinsk Test Site. It also presents methodology of calculating ecological and economical parameters for different options. Besides, the paper provides data describing assessment of ecological and economical damage caused by defense establishment activities at the Semipalatinsk Test Site. (author)

Use of extremity insulation during whole body hyperthermia to reduce temperature nonuniformity

International Nuclear Information System (INIS)

Thrall, D.E.; Page, R.L.

1987-01-01

The author previously documented during whole body hyperthermia in dogs using a radiant heating device that temperature at superficial sites, including tibial bone marrow, falls below systemic arterial temperature during the plateau phase of heating. This may be due to direct heat loss to the environment. Sites where temperature is lower than systemic arterial temperature during the plateau phase may become sanctuary sites where tumor deposits are spared because they do not receive the prescribed thermal dose. In an attempt to decrease temperature nonuniformity and increase thermal dose delivered to such superficial sites, extremity insulation has been employed during whole body hyperthermia in dogs. The author measured temperature at cutaneous and subcutaneous sites and within tibial bone marrow in insulated and noninsulated extremities of dogs undergoing whole body hyperthermia in the radiant heating device. The author found that extremity insulation is effective in reducing extremity temperature nonuniformity. Specific results are presented. Extremity insulation may be necessary during whole body hyperthermia to assure that extremity tumor deposits receive a thermal dose similar to that prescribed for the entire body

Prevention through policy : Urban macroplastic leakages to the marine environment during extreme rainfall events

NARCIS (Netherlands)

Axelsson, Charles; van Sebille, Erik

2017-01-01

The leakage of large plastic litter (macroplastics) into the ocean is a major environmental problem. A significant fraction of this leakage originates from coastal cities, particularly during extreme rainfall events. As coastal cities continue to grow, finding ways to reduce this macroplastic

Automatic residue removal for high-NA extreme illumination

Science.gov (United States)

Moon, James; Nam, Byong-Sub; Jeong, Joo-Hong; Kong, Dong-Ho; Nam, Byung-Ho; Yim, Dong Gyu

2007-10-01

An epidemic for smaller node has been that, as the device architecture shrinks, lithography process requires high Numerical Aperture (NA), and extreme illumination system. This, in turn, creates many lithography problems such as low lithography process margin (Depth of Focus, Exposure Latitude), unstable Critical Dimension (CD) uniformity and restricted guideline for device design rule and so on. Especially for high NA, extreme illumination such as immersion illumination systems, above all the related problems, restricted design rule due to forbidden pitch is critical and crucial issue. This forbidden pitch is composed of numerous optical effects but majority of these forbidden pitch compose of photo resist residue and these residue must be removed to relieve some room for already tight design rule. In this study, we propose automated algorithm to remove photo resist residue due to high NA and extreme illumination condition. This algorithm automatically self assembles assist patterns based on the original design layout, therefore insuring the safety and simplicity of the generated assist pattern to the original design and removes any resist residue created by extreme illumination condition. Also we tested our automated algorithm on full chip FLASH memory device and showed the residue removal effect by using commercial verification tools as well as on actual test wafer.

(When and where) Do extreme climate events trigger extreme ecosystem responses? - Development and initial results of a holistic analysis framework

Science.gov (United States)

Hauber, Eva K.; Donner, Reik V.

2015-04-01

In the context of ongoing climate change, extremes are likely to increase in magnitude and frequency. One of the most important consequences of these changes is that the associated ecological risks and impacts are potentially rising as well. In order to better anticipate and understand these impacts, it therefore becomes more and more crucial to understand the general connection between climate extremes and the response and functionality of ecosystems. Among other region of the world, Europe presents an excellent test case for studies concerning the interaction between climate and biosphere, since it lies in the transition region between cold polar and warm tropical air masses and thus covers a great variety of different climatic zones and associated terrestrial ecosystems. The large temperature differences across the continent make this region particularly interesting for investigating the effects of climate change on biosphere-climate interactions. However, previously used methods for defining an extreme event typically disregard the necessity of taking seasonality as well as seasonal variance appropriately into account. Furthermore, most studies have focused on the impacts of individual extreme events instead of considering a whole inventory of extremes with their respective spatio-temporal extents. In order to overcome the aforementioned research gaps, this work introduces a new approach to studying climate-biosphere interactions associated with extreme events, which comprises three consecutive steps: (1) Since Europe exhibits climatic conditions characterized by marked seasonality, a novel method is developed to define extreme events taking into account the seasonality in all quantiles of the probability distribution of the respective variable of interest. This is achieved by considering kernel density estimates individually for each observation date during the year, including the properly weighted information from adjacent dates. By this procedure, we obtain

Manual muscle testing: a method of measuring extremity muscle strength applied to critically ill patients.

Science.gov (United States)

Ciesla, Nancy; Dinglas, Victor; Fan, Eddy; Kho, Michelle; Kuramoto, Jill; Needham, Dale

2011-04-12

Survivors of acute respiratory distress syndrome (ARDS) and other causes of critical illness often have generalized weakness, reduced exercise tolerance, and persistent nerve and muscle impairments after hospital discharge. Using an explicit protocol with a structured approach to training and quality assurance of research staff, manual muscle testing (MMT) is a highly reliable method for assessing strength, using a standardized clinical examination, for patients following ARDS, and can be completed with mechanically ventilated patients who can tolerate sitting upright in bed and are able to follow two-step commands. (7, 8) This video demonstrates a protocol for MMT, which has been taught to ≥ 43 research staff who have performed >800 assessments on >280 ARDS survivors. Modifications for the bedridden patient are included. Each muscle is tested with specific techniques for positioning, stabilization, resistance, and palpation for each score of the 6-point ordinal Medical Research Council scale. Three upper and three lower extremity muscles are graded in this protocol: shoulder abduction, elbow flexion, wrist extension, hip flexion, knee extension, and ankle dorsiflexion. These muscles were chosen based on the standard approach for evaluating patients for ICU-acquired weakness used in prior publications. (1,2).

Cell-Sediment Separation and Elemental Stoichiometries in Extreme Environments

Science.gov (United States)

Neveu, M.; Poret-peterson, A. T.; Lee, Z. M.; Anbar, A. D.; Elser, J. J.

2012-12-01

counting by epifluorescence microscopy indicated a cell recovery yield between 6 and 40% in field-collected samples (95% for cultured E. coli). Aluminum, assumed to be non-biological in origin, was used to estimate the extent of mineral contamination of isolated cell communities. These results show that our method is successful at separating microbial cells from sediment collected in extreme environments and preserving them for analysis of a broad suite of elements. Photosynthetic sites yielded much more cell material than hotter, chemosynthetic sites (Cox et al., 2011). We are currently measuring cellular elemental abundances and ratios in samples from relatively low-temperature (25 to 65°C), photosynthetic areas, spanning a wide range of pH (2 to 9.5) and composition. These measurements will be compared to existing datasets on the bulk sediment stoichiometry of these ecosystems, and to previous observations of cellular elemental composition. References: Redfield, A.C. (1934) In Daniel, R.J. [Ed.], James Johnstone Memorial Volume, pp. 176-192, Univ. Press Liverpool. Sterner, R.W., Elser, J.J. (2002) Ecological Stoichiometry Princeton Univ. Press, 441p. Havig, J.R., et al. (2011) JGR 116, G01005. Amalfitano, S., Fazi, S. (2008) J. of Microbiol. Methods 75, 237-243. Cox, A., et al. (2011) Chem. Geol. 280, 344-351.

Phenotypic Tests for the Detection of β-Lactamase-Producing Enterobacteriaceae Isolated from Different Environments.

Science.gov (United States)

de Oliveira, Daniele V; Van Der Sand, Sueli T

2016-07-01

Some bacteria from the Enterobacteriaceae family are showing a significant capability to disseminate β-lactams resistance mechanisms among them, and these same mechanisms can be carried out from the hospital environment to superficial water. The aim of this study was to evaluate different phenotypic methods for the detection β-lactamases production by enterobacteria isolated from the anthropogenic environment: hospital wastewater and from a stream that cross the city of Porto Alegre. The applied tests were the modified Hodge test (MHT) and phenotypic tests with the following inhibitors: carbapenemase-phenylboronic acid (APB), metallo-β-lactamase-EDTA, AmpC β-lactamase-cloxacillin, and the confirmatory test for extended-spectrum β-lactamase (ESBL)-clavulanic acid. For this evaluation, 131 isolates were initially subjected to antibiogram using the following antimicrobials: cefotaxime (30 µg), cefpodoxime (10 μg), ceftazidime (30 µg), ertapenem (10 μg), meropenem (10 μg), and aztreonam (30 μg). After this first screening, 62 isolates showed a profile resistance for at least one antimicrobial. These isolates were subjected to all phenotypic tests. Of those, 40 isolates were positive for at least one phenotypic test. In MHT test, one isolate was positive and five were with inconclusive results. The results achieved with the inhibitors are as follows: APB 25/40 positive strains; EDTA 8/40 positive strains; and with CLOXA 2/40 positive strains. ESBL production was observed for 34/40 strains. This assessment shows a high level of bacteria which can produce enzymes that inactivate β-lactams present in the different environment like the stream waters and from the hospital settings.

How extreme is extreme hourly precipitation?

Science.gov (United States)

Papalexiou, Simon Michael; Dialynas, Yannis G.; Pappas, Christoforos

2016-04-01

The importance of accurate representation of precipitation at fine time scales (e.g., hourly), directly associated with flash flood events, is crucial in hydrological design and prediction. The upper part of a probability distribution, known as the distribution tail, determines the behavior of extreme events. In general, and loosely speaking, tails can be categorized in two families: the subexponential and the hyperexponential family, with the first generating more intense and more frequent extremes compared to the latter. In past studies, the focus has been mainly on daily precipitation, with the Gamma distribution being the most popular model. Here, we investigate the behaviour of tails of hourly precipitation by comparing the upper part of empirical distributions of thousands of records with three general types of tails corresponding to the Pareto, Lognormal, and Weibull distributions. Specifically, we use thousands of hourly rainfall records from all over the USA. The analysis indicates that heavier-tailed distributions describe better the observed hourly rainfall extremes in comparison to lighter tails. Traditional representations of the marginal distribution of hourly rainfall may significantly deviate from observed behaviours of extremes, with direct implications on hydroclimatic variables modelling and engineering design.

Extreme Environment Circuit Blocks for Spacecraft Power & Propulsion System & Other High Reliability Applications, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Chronos Technology (DIv of FMI, Inc.) proposes to design, fabricate, and deliver a performance proven, and commercially available set of extreme high operating...

What are extreme environmental conditions and how do organisms cope with them?

Directory of Open Access Journals (Sweden)

John C. WINGFIELD, J. Patrick KELLEY, Frédéric ANGELIER

2011-06-01

Full Text Available Severe environmental conditions affect organisms in two major ways. The environment may be predictably severe such as in deserts, polar and alpine regions, or individuals may be exposed to temporarily extreme conditions through weather, presence of predators, lack of food, social status etc. Existence in an extreme environment may be possible, but then to breed or molt in addition can present major bottlenecks that have resulted in the evolution of hormone-behavior adaptations to cope with unpredictable events. Examples of hormone-behavior adaptations in extreme conditions include attenuated testosterone secretion because territoriality and excess courtship may be too costly when there is one opportunity to reproduce. The individual may even become insensitive to testosterone when target areas of the brain regulating reproductive behavior no longer respond to the hormone. A second example is reduced sensitivity to glucocorticoids following acute stress during the breeding season or molt that allows successful reproduction and/or a vital renewal of the integument to endure extreme conditions during the rest of the year. Reduced sensitivity could involve: (a modulated response of the hypothalamo-pituitary-adrenal axis, (b reduced sensitivity to high glucocorticoid levels, or (c a combination of (a and (b. Moreover, corticosteroid binding proteins (CBP buffer responses to stress by reducing the movement of glucocorticoids into target cells. Finally, intracellular enzymes (11b-hydroxysteroid dehydrogenase and variants can deactivate glucocorticoids entering cells thus reducing interaction with receptors. These mechanisms have important implications for climate change and increasing extremes of weather [Current Zoology 57 (3: 363–374, 2011].

Presence in a Three-Dimensional Test Environment: Benefit or Threat to Market Research?

OpenAIRE

Alma Berneburg

2008-01-01

In market research, the adoption of interactive virtual reality-techniques could be expected to contain many advantages: artificial lab environments could be designed in a more realistic manner and the consideration of “time to the market”-factors could be improved. On the other hand, with an increasing degree of presence and the notional attendance in a simulated test environment, the market research task could fall prey to the tensing virtual reality adventure. In...

Clinical application of lower extremity CTA and lower extremity perfusion CT as a method of diagnostic for lower extremity atherosclerotic obliterans

Energy Technology Data Exchange (ETDEWEB)

Moon, Il Bong; Dong, Kyung Rae [Dept. Radiological Technology, Gwangju Health University, Gwangju (Korea, Republic of); Goo, Eun Hoe [Dept. Radiological Science, Cheongju University, Cheongju (Korea, Republic of)

2016-11-15

The purpose of this study was to assess clinical application of lower extremity CTA and lower extremity perfusion CT as a method of diagnostic for lower extremity atherosclerotic obliterans. From January to July 2016, 30 patients (mean age, 68) were studied with lower extremity CTA and lower extremity perfusion CT. 128 channel multi-detector row CT scans were acquired with a CT scanner (SOMATOM Definition Flash, Siemens medical solution, Germany) of lower extremity perfusion CT and lower extremity CTA. Acquired images were reconstructed with 3D workstation (Leonardo, Siemens, Germany). Site of lower extremity arterial occlusive and stenosis lesions were detected superficial femoral artery 36.6%, popliteal artery 23.4%, external iliac artery 16.7%, common femoral artery 13.3%, peroneal artery 10%. The mean total DLP comparison of lower extremity perfusion CT and lower extremity CTA, 650 mGy-cm and 675 mGy-cm, respectively. Lower extremity perfusion CT and lower extremity CTA were realized that were never be two examination that were exactly the same legions. Future through the development of lower extremity perfusion CT soft ware programs suggest possible clinical applications.

Performance of Portable Ventilators Following Storage at Temperature Extremes.

Science.gov (United States)

Blakeman, Thomas C; Rodriquez, Dario; Britton, Tyler J; Johannigman, Jay A; Petro, Michael C; Branson, Richard D

2016-05-01

In the current theater of operation, medical devices are often shipped and stored at ambient conditions. The effect of storage at hot and cold temperature extremes on ventilator performance is unknown. We evaluated three portable ventilators currently in use or being evaluated for use by the Department of Defense (731, Impact Instrumentation; T1, Hamilton Medical; and Revel, CareFusion) at temperature extremes in a laboratory setting. The ventilators were stored at temperatures of 60°C and -35°C for 24 hours and were allowed to acclimate to room temperature for 30 minutes before evaluation. The T1 required an extra 15 to 30 minutes of acclimation to room temperature before the ventilator would deliver breaths. All delivered tidal volumes at room temperature and after storage at temperature extremes were less than the ±10% American Society for Testing and Materials standard with the Revel. Delivered tidal volumes at the pediatric settings were less than the ±10% threshold after storage at both temperatures and at room temperature with the 731. Storage at extreme temperature affected the performance of the portable ventilators tested. This study showed that portable ventilators may need an hour or more of acclimation time at room temperature after storage at temperature extremes to operate as intended. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Thermodynamics of extremal rotating thin shells in an extremal BTZ spacetime and the extremal black hole entropy

Science.gov (United States)

Lemos, José P. S.; Minamitsuji, Masato; Zaslavskii, Oleg B.

2017-02-01

In a (2 +1 )-dimensional spacetime with a negative cosmological constant, the thermodynamics and the entropy of an extremal rotating thin shell, i.e., an extremal rotating ring, are investigated. The outer and inner regions with respect to the shell are taken to be the Bañados-Teitelbom-Zanelli (BTZ) spacetime and the vacuum ground state anti-de Sitter spacetime, respectively. By applying the first law of thermodynamics to the extremal thin shell, one shows that the entropy of the shell is an arbitrary well-behaved function of the gravitational area A+ alone, S =S (A+). When the thin shell approaches its own gravitational radius r+ and turns into an extremal rotating BTZ black hole, it is found that the entropy of the spacetime remains such a function of A+, both when the local temperature of the shell at the gravitational radius is zero and nonzero. It is thus vindicated by this analysis that extremal black holes, here extremal BTZ black holes, have different properties from the corresponding nonextremal black holes, which have a definite entropy, the Bekenstein-Hawking entropy S (A+)=A/+4G , where G is the gravitational constant. It is argued that for extremal black holes, in particular for extremal BTZ black holes, one should set 0 ≤S (A+)≤A/+4G;i.e., the extremal black hole entropy has values in between zero and the maximum Bekenstein-Hawking entropy A/+4 G . Thus, rather than having just two entropies for extremal black holes, as previous results have debated, namely, 0 and A/+4 G , it is shown here that extremal black holes, in particular extremal BTZ black holes, may have a continuous range of entropies, limited by precisely those two entropies. Surely, the entropy that a particular extremal black hole picks must depend on past processes, notably on how it was formed. A remarkable relation between the third law of thermodynamics and the impossibility for a massive body to reach the velocity of light is also found. In addition, in the procedure, it

A Generalized Framework for Non-Stationary Extreme Value Analysis

Science.gov (United States)

Ragno, E.; Cheng, L.; Sadegh, M.; AghaKouchak, A.

2017-12-01

Empirical trends in climate variables including precipitation, temperature, snow-water equivalent at regional to continental scales are evidence of changes in climate over time. The evolving climate conditions and human activity-related factors such as urbanization and population growth can exert further changes in weather and climate extremes. As a result, the scientific community faces an increasing demand for updated appraisal of the time-varying climate extremes. The purpose of this study is to offer a robust and flexible statistical tool for non-stationary extreme value analysis which can better characterize the severity and likelihood of extreme climatic variables. This is critical to ensure a more resilient environment in a changing climate. Following the positive feedback on the first version of Non-Stationary Extreme Value Analysis (NEVA) Toolbox by Cheng at al. 2014, we present an improved version, i.e. NEVA2.0. The upgraded version herein builds upon a newly-developed hybrid evolution Markov Chain Monte Carlo (MCMC) approach for numerical parameters estimation and uncertainty assessment. This addition leads to a more robust uncertainty estimates of return levels, return periods, and risks of climatic extremes under both stationary and non-stationary assumptions. Moreover, NEVA2.0 is flexible in incorporating any user-specified covariate other than the default time-covariate (e.g., CO2 emissions, large scale climatic oscillation patterns). The new feature will allow users to examine non-stationarity of extremes induced by physical conditions that underlie the extreme events (e.g. antecedent soil moisture deficit, large-scale climatic teleconnections, urbanization). In addition, the new version offers an option to generate stationary and/or non-stationary rainfall Intensity - Duration - Frequency (IDF) curves that are widely used for risk assessment and infrastructure design. Finally, a Graphical User Interface (GUI) of the package is provided, making NEVA

Standard Test Methods for Photovoltaic Modules in Cyclic Temperature and Humidity Environments

CERN Document Server

American Society for Testing and Materials. Philadelphia

2009-01-01

1.1 These test methods provide procedures for stressing photovoltaic modules in simulated temperature and humidity environments. Environmental testing is used to simulate aging of module materials on an accelerated basis. 1.2 Three individual environmental test procedures are defined by these test methods: a thermal cycling procedure, a humidity-freeze cycling procedure, and an extended duration damp heat procedure. Electrical biasing is utilized during the thermal cycling procedure to simulate stresses that are known to occur in field-deployed modules. 1.3 These test methods define mounting methods for modules undergoing environmental testing, and specify parameters that must be recorded and reported. 1.4 These test methods do not establish pass or fail levels. The determination of acceptable or unacceptable results is beyond the scope of these test methods. 1.5 Any of the individual environmental tests may be performed singly, or may be combined into a test sequence with other environmental or non-envir...

Rain Characteristics and Large-Scale Environments of Precipitation Objects with Extreme Rain Volumes from TRMM Observations

Science.gov (United States)

Zhou, Yaping; Lau, William K M.; Liu, Chuntao

2013-01-01

This study adopts a "precipitation object" approach by using 14 years of Tropical Rainfall Measuring Mission (TRMM) Precipitation Feature (PF) and National Centers for Environmental Prediction (NCEP) reanalysis data to study rainfall structure and environmental factors associated with extreme heavy rain events. Characteristics of instantaneous extreme volumetric PFs are examined and compared to those of intermediate and small systems. It is found that instantaneous PFs exhibit a much wider scale range compared to the daily gridded precipitation accumulation range. The top 1% of the rainiest PFs contribute over 55% of total rainfall and have 2 orders of rain volume magnitude greater than those of the median PFs. We find a threshold near the top 10% beyond which the PFs grow exponentially into larger, deeper, and colder rain systems. NCEP reanalyses show that midlevel relative humidity and total precipitable water increase steadily with increasingly larger PFs, along with a rapid increase of 500 hPa upward vertical velocity beyond the top 10%. This provides the necessary moisture convergence to amplify and sustain the extreme events. The rapid increase in vertical motion is associated with the release of convective available potential energy (CAPE) in mature systems, as is evident in the increase in CAPE of PFs up to 10% and the subsequent dropoff. The study illustrates distinct stages in the development of an extreme rainfall event including: (1) a systematic buildup in large-scale temperature and moisture, (2) a rapid change in rain structure, (3) explosive growth of the PF size, and (4) a release of CAPE before the demise of the event.

The International Space Station: A Low-Earth Orbit (LEO) Test Bed for Advancements in Space and Environmental Medicine

Science.gov (United States)

Ruttley, Tara M.; Robinson, Julie A.

2010-01-01

Ground-based space analog projects such as the NASA Extreme Environment Mission Operations (NEEMO) can be valuable test beds for evaluation of experimental design and hardware feasibility before actually being implemented on orbit. The International Space Station (ISS) is an closed-system laboratory that orbits 240 miles above the Earth, and is the ultimate extreme environment. Its inhabitants spend hours performing research that spans from fluid physics to human physiology, yielding results that have implications for Earth-based improvements in medicine and health, as well as those that will help facilitate the mitigation of risks to the human body associated with exploration-class space missions. ISS health and medical experiments focus on pre-flight and in-flight prevention, in-flight treatment, and postflight recovery of health problems associated with space flight. Such experiments include those on enhanced medical monitoring, bone and muscle loss prevention, cardiovascular health, immunology, radiation and behavior. Lessons learned from ISS experiments may not only be applicable to other extreme environments that face similar capability limitations, but also serve to enhance standards of care for everyday use on Earth.

76 FR 34246 - Automated Commercial Environment (ACE); Announcement of National Customs Automation Program Test...

Science.gov (United States)

2011-06-13

... Environment (ACE); Announcement of National Customs Automation Program Test of Automated Procedures for In... Customs Automation Program (NCAP) test relating to highway movements of commercial goods that are transported in-bond through the United States from one point in Canada to another point in Canada. The NCAP...

Predictive testing of performance of metals in HTR service environments

International Nuclear Information System (INIS)

Kondo, T.; Shindo, M.; Tamura, M.; Tsuji, H.; Kurata, Y.; Tsukada, T.

1982-01-01

Status of the material testing in simulated HTGR environment is reviewed with special attention focused on the methodology of the prediction of performance in long time. Importance of controlling effective chemical potentials relations in the material-environmental interface is stressed in regard of the complex inter-dependent kinetic relation between oxidation and carbon transport. Based on the recent experimental observations, proposals are made to establish some procedures for conservative prediction of the metal performance

Extreme value distributions

CERN Document Server

Ahsanullah, Mohammad

2016-01-01

The aim of the book is to give a through account of the basic theory of extreme value distributions. The book cover a wide range of materials available to date. The central ideas and results of extreme value distributions are presented. The book rwill be useful o applied statisticians as well statisticians interrested to work in the area of extreme value distributions.vmonograph presents the central ideas and results of extreme value distributions.The monograph gives self-contained of theory and applications of extreme value distributions.

An Overview of Materials Structures for Extreme Environments Efforts for 2015 SBIR Phases I and II

Science.gov (United States)

Nguyen, Hung D.; Steele, Gynelle C.

2017-01-01

Technological innovation is the overall focus of NASA's Small Business Innovation Research (SBIR) program. The program invests in the development of innovative concepts and technologies to help NASA's mission directorates address critical research and development needs for Agency projects. This report highlights innovative SBIR 2015 Phase I and II projects that specifically address areas in Materials and Structures for Extreme Environments, one of six core competencies at NASA Glenn Research Center. Each article describes an innovation, defines its technical objective, and highlights NASA applications as well as commercial and industrial applications. Ten technologies are featured: metamaterials-inspired aerospace structures, metallic joining to advanced ceramic composites, multifunctional polyolefin matrix composite structures, integrated reacting fluid dynamics and predictive materials degradation models for propulsion system conditions, lightweight inflatable structural airlock (LISA), copolymer materials for fused deposition modeling 3-D printing of nonstandard plastics, Type II strained layer superlattice materials development for space-based focal plane array applications, hydrogenous polymer-regolith composites for radiation-shielding materials, a ceramic matrix composite environmental barrier coating durability model, and advanced composite truss printing for large solar array structures. This report serves as an opportunity for NASA engineers, researchers, program managers, and other personnel to learn about innovations in this technology area as well as possibilities for collaboration with innovative small businesses that could benefit NASA programs and projects.

Are extreme hydro-meteorological events a prerequisite for extreme water quality impacts? Exploring climate impacts on inland and coastal waters

Science.gov (United States)

Michalak, A. M.; Balaji, V.; Del Giudice, D.; Sinha, E.; Zhou, Y.; Ho, J. C.

2017-12-01

Questions surrounding water sustainability, climate change, and extreme events are often framed around water quantity - whether too much or too little. The massive impacts of extreme water quality impairments are equally compelling, however. Recent years have provided a host of compelling examples, with unprecedented harmful algal blooms developing along the West coast, in Utah Lake, in Lake Erie, and off the Florida coast, and huge hypoxic dead zones continuing to form in regions such as Lake Erie, the Chesapeake Bay, and the Gulf of Mexico. Linkages between climate change, extreme events, and water quality impacts are not well understood, however. Several factors explain this lack of understanding, including the relative complexity of underlying processes, the spatial and temporal scale mismatch between hydrologists and climatologists, and observational uncertainty leading to ambiguities in the historical record. Here, we draw on a number of recent studies that aim to quantitatively link meteorological variability and water quality impacts to test the hypothesis that extreme water quality impairments are the result of extreme hydro-meteorological events. We find that extreme hydro-meteorological events are neither always a necessary nor a sufficient condition for the occurrence of extreme water quality impacts. Rather, extreme water quality impairments often occur in situations where multiple contributing factors compound, which complicates both attribution of historical events and the ability to predict the future incidence of such events. Given the critical societal importance of water quality projections, a concerted program of uncertainty reduction encompassing observational and modeling components will be needed to examine situations where extreme weather plays an important, but not solitary, role in the chain of cause and effect.

Time-varying Concurrent Risk of Extreme Droughts and Heatwaves in California

Science.gov (United States)

Sarhadi, A.; Diffenbaugh, N. S.; Ausin, M. C.

2016-12-01

Anthropogenic global warming has changed the nature and the risk of extreme climate phenomena such as droughts and heatwaves. The concurrent of these nature-changing climatic extremes may result in intensifying undesirable consequences in terms of human health and destructive effects in water resources. The present study assesses the risk of concurrent extreme droughts and heatwaves under dynamic nonstationary conditions arising from climate change in California. For doing so, a generalized fully Bayesian time-varying multivariate risk framework is proposed evolving through time under dynamic human-induced environment. In this methodology, an extreme, Bayesian, dynamic copula (Gumbel) is developed to model the time-varying dependence structure between the two different climate extremes. The time-varying extreme marginals are previously modeled using a Generalized Extreme Value (GEV) distribution. Bayesian Markov Chain Monte Carlo (MCMC) inference is integrated to estimate parameters of the nonstationary marginals and copula using a Gibbs sampling method. Modelled marginals and copula are then used to develop a fully Bayesian, time-varying joint return period concept for the estimation of concurrent risk. Here we argue that climate change has increased the chance of concurrent droughts and heatwaves over decades in California. It is also demonstrated that a time-varying multivariate perspective should be incorporated to assess realistic concurrent risk of the extremes for water resources planning and management in a changing climate in this area. The proposed generalized methodology can be applied for other stochastic nature-changing compound climate extremes that are under the influence of climate change.

The effects of test environment and cyclic stretching on the failure properties of human patellar tendons

International Nuclear Information System (INIS)

Haut, R.C.; Powlison, A.C.

1990-01-01

There is a need to document the mechanical properties of patellar tendon allografts used for reconstructive surgery of the damaged anterior cruciate ligament, especially the effects of irradiation sterilization. The purpose of this study was to investigate the influences of in vitro test environment and low-level cyclic stretching prior to failure tests on nonirradiated and irradiated human graft tissues. Bilateral patellar tendons were split and each half processed accordingly. Some graft tissues were stretched cyclically at 2.5 mm deformation before failure. Experiments were performed in a 37 degrees C saline bath or with tissues moistened with a drip of the same. The irradiated grafts relaxed less and generated less slack length in the drip environment than the nonirradiated controls. Cyclic stretching did not alter failure characteristics of either graft tissue. While no significant differences in the tensile responses or failure characteristics were noted for irradiated and nonirradiated grafts in the drip, in the bath environment the nonirradiated tissues had greater strength and modulus. This resulted in there being a significant difference between irradiated and nonirradiated tissue responses in a heated saline bath environment. These experimental results exemplify the need to control in vitro test environments in the evaluation of various sterilization and preservation protocols for soft tissue allografts

Bell Test over Extremely High-Loss Channels: Towards Distributing Entangled Photon Pairs between Earth and the Moon

Science.gov (United States)

Cao, Yuan; Li, Yu-Huai; Zou, Wen-Jie; Li, Zheng-Ping; Shen, Qi; Liao, Sheng-Kai; Ren, Ji-Gang; Yin, Juan; Chen, Yu-Ao; Peng, Cheng-Zhi; Pan, Jian-Wei

2018-04-01

Quantum entanglement was termed "spooky action at a distance" in the well-known paper by Einstein, Podolsky, and Rosen. Entanglement is expected to be distributed over longer and longer distances in both practical applications and fundamental research into the principles of nature. Here, we present a proposal for distributing entangled photon pairs between Earth and the Moon using a Lagrangian point at a distance of 1.28 light seconds. One of the most fascinating features in this long-distance distribution of entanglement is as follows. One can perform the Bell test with human supplying the random measurement settings and recording the results while still maintaining spacelike intervals. To realize a proof-of-principle experiment, we develop an entangled photon source with 1 GHz generation rate, about 2 orders of magnitude higher than previous results. Violation of Bell's inequality was observed under a total simulated loss of 103 dB with measurement settings chosen by two experimenters. This demonstrates the feasibility of such long-distance Bell test over extremely high-loss channels, paving the way for one of the ultimate tests of the foundations of quantum mechanics.

Mechanical properties test program on structural materials in a sodium environment

International Nuclear Information System (INIS)

Natesan, K.; Chopra, O.K.; Kassner, T.F.

1979-10-01

This document describes in detail the ongoing and planned US Test program on the mechanical properties of sodium-exposed Type 316 austenitic stainless and Fe-2 1/4 Cr-1 Mo ferritic steels. The test program is based on the Development Requirement Specifications (DRS) established by the DOE/Clinch River Breeder Reactor Project (CRBRP) Program Office, the general need for the development of LMFBR structural-design criteria established by the Nuclear Systems Materials Handbook, and the need for a fundamental understanding of materials behavior in a sodium environment, which is generic to LMFBR systems. The planned test program is an extension of work based on current knowledge of sodium chemistry and the influence of sodium purity on the mechanical properties of structural materials

Relationships of Functional Tests Following ACL Reconstruction: Exploratory Factor Analyses of the Lower Extremity Assessment Protocol.

Science.gov (United States)

DiFabio, Melissa; Slater, Lindsay V; Norte, Grant; Goetschius, John; Hart, Joseph M; Hertel, Jay

2018-03-01

After ACL reconstruction (ACLR), deficits are often assessed using a variety of functional tests, which can be time consuming. It is unknown whether these tests provide redundant or unique information. To explore relationships between components of a battery of functional tests, the Lower Extremity Assessment Protocol (LEAP) was created to aid in developing the most informative, concise battery of tests for evaluating ACLR patients. Descriptive, cross-sectional. Laboratory. 76 ACLR patients (6.86±3.07 months postoperative) and 54 healthy participants. Isokinetic knee flexion and extension at 90 and 180 degrees/second, maximal voluntary isometric contraction for knee extension and flexion, single leg balance, 4 hopping tasks (single, triple, crossover, and 6-meter timed hop), and a bilateral drop vertical jump that was scored with the Landing Error Scoring System (LESS). Peak torque, average torque, average power, total work, fatigue indices, center of pressure area and velocity, hop distance and time, and LESS score. A series of factor analyses were conducted to assess grouping of functional tests on the LEAP for each limb in the ACLR and healthy groups and limb symmetry indices (LSI) for both groups. Correlations were run between measures that loaded on retained factors. Isokinetic and isometric strength tests for knee flexion and extension, hopping, balance, and fatigue index were identified as unique factors for all limbs. The LESS score loaded with various factors across the different limbs. The healthy group LSI analysis produced more factors than the ACLR LSI analysis. Individual measures within each factor had moderate to strong correlations. Isokinetic and isometric strength, hopping, balance, and fatigue index provided unique information. Within each category of measures, not all tests may need to be included for a comprehensive functional assessment of ACLR patients due to the high amount of shared variance between them.

Hardware-in-the-loop environment for the design and test of regulators in the refrigeration technology; Hardware-in-the-Loop Umgebung fuer den Entwurf und Test von kaeltetechnischen Reglern

Energy Technology Data Exchange (ETDEWEB)

Koeberle, Thomas; Becker, Martin [Hochschule Biberach (Germany). Inst. fuer Gebaeude- und Energiesysteme

2012-07-01

In its Directive on energy efficiency, The European Commission has specified a target value for saving primary energy by 20 % up the year 2020. According to current projections, the target will be failed by half. This is why significantly more efforts are needed. The energy consumption of the technical supply of coldness amounts nearly 14 % of the total consumption of electrical power in Germany. The Research Council Coldness specifies that the potential for energy conservation in the refrigeration engineering amounts up to 40 %. Thus, more effort must be made in the refrigeration engineering in order to reach the energy saving targets of the European Commission. Thereby, the major portion of the potential of energy saving consists of the establishment of the requirements in regard to system concepts and components as well as the control. The control of refrigeration systems provides a simple possibility of intervention to optimize the energy efficiency. The optimization of control parameters is usually achieved only with great experience and knowledge. There are any tools which facilitate an objective comparison of optimization measures of control concepts, strategies and settings. In order to facilitate the evaluation and comparison of refrigeration controls, a hardware-in-the-loop test environment was set up at the University of Applied Sciences in Biberach (Federal Republic of Germany). The test environment facilitates an implementation of a controller in a simulation environment so that the controller drives the simulation model of the chiller. Due to this procedure, tests are possible under standardized and reproducible conditions. The impact of modified control parameters, disturbances and modifications in the regulatory approach can be investigated by means of the possibility of a targeted impacting of individual disturbances. The test rig was designed, built and tested at the University of Applied Sciences in Biberach. Simulation models were adapted to the

Extremely Low Mass: The Circumstellar Envelope of a Potential Proto-Brown Dwarf

Science.gov (United States)

Wiseman, Jennifer

2011-01-01

What is the environment for planet formation around extremely low mass stars? Is the environment around brown dwarfs and extremely low mass stars conducive and sufficiently massive for planet production? The determining conditions may be set very early in the process of the host object's formation. IRAS 16253-2429, the source of the Wasp-Waist Nebula seen in Spitzer IRAC images, is an isolated, very low luminosity ("VeLLO") Class 0 protostar in the nearby rho Ophiuchi cloud. We present VLA ammonia mapping observations of the dense gas envelope feeding the central core accreting system. We find a flattened envelope perpendicular to the outflow axis, and gas cavities that appear to cradle the outflow lobes as though carved out by the flow and associated (apparently precessing) jet, indicating environmental disruption. Based on the NH3 (1,1) and (2,2) emission distribution, we derive the mass, velocity fields and temperature distribution for the envelope. We discuss the combined evidence for this source to be one of the youngest and lowest mass sources in formation yet known, and discuss the ramifications for planet formation potential in this extremely low mass system.

Plant Responses to Extreme Climatic Events: A Field Test of Resilience Capacity at the Southern Range Edge

Science.gov (United States)

Herrero, Asier; Zamora, Regino

2014-01-01

The expected and already observed increment in frequency of extreme climatic events may result in severe vegetation shifts. However, stabilizing mechanisms promoting community resilience can buffer the lasting impact of extreme events. The present work analyzes the resilience of a Mediterranean mountain ecosystem after an extreme drought in 2005, examining shoot-growth and needle-length resistance and resilience of dominant tree and shrub species (Pinus sylvestris vs Juniperus communis, and P. nigra vs J. oxycedrus) in two contrasting altitudinal ranges. Recorded high vegetative-resilience values indicate great tolerance to extreme droughts for the dominant species of pine-juniper woodlands. Observed tolerance could act as a stabilizing mechanism in rear range edges, such as the Mediterranean basin, where extreme events are predicted to be more detrimental and recurrent. However, resistance and resilience components vary across species, sites, and ontogenetic states: adult Pinus showed higher growth resistance than did adult Juniperus; saplings displayed higher recovery rates than did conspecific adults; and P. nigra saplings displayed higher resilience than did P. sylvestris saplings where the two species coexist. P. nigra and J. oxycedrus saplings at high and low elevations, respectively, were the most resilient at all the locations studied. Under recurrent extreme droughts, these species-specific differences in resistance and resilience could promote changes in vegetation structure and composition, even in areas with high tolerance to dry conditions. PMID:24489971

Plant responses to extreme climatic events: a field test of resilience capacity at the southern range edge.

Directory of Open Access Journals (Sweden)

Asier Herrero

Full Text Available The expected and already observed increment in frequency of extreme climatic events may result in severe vegetation shifts. However, stabilizing mechanisms promoting community resilience can buffer the lasting impact of extreme events. The present work analyzes the resilience of a Mediterranean mountain ecosystem after an extreme drought in 2005, examining shoot-growth and needle-length resistance and resilience of dominant tree and shrub species (Pinus sylvestris vs Juniperus communis, and P. nigra vs J. oxycedrus in two contrasting altitudinal ranges. Recorded high vegetative-resilience values indicate great tolerance to extreme droughts for the dominant species of pine-juniper woodlands. Observed tolerance could act as a stabilizing mechanism in rear range edges, such as the Mediterranean basin, where extreme events are predicted to be more detrimental and recurrent. However, resistance and resilience components vary across species, sites, and ontogenetic states: adult Pinus showed higher growth resistance than did adult Juniperus; saplings displayed higher recovery rates than did conspecific adults; and P. nigra saplings displayed higher resilience than did P. sylvestris saplings where the two species coexist. P. nigra and J. oxycedrus saplings at high and low elevations, respectively, were the most resilient at all the locations studied. Under recurrent extreme droughts, these species-specific differences in resistance and resilience could promote changes in vegetation structure and composition, even in areas with high tolerance to dry conditions.

Dissociating indifferent, directional, and extreme responding in personality data

DEFF Research Database (Denmark)

Zettler, Ingo; Lang, Jonas W B; Hülsheger, Ute R

2015-01-01

- and observer reports of personality traits. The three-process model captures indifferent, directional, and extreme responding. Substantively, we hypothesize that, and test whether, trait Honesty-Humility is negatively linked to extreme responding. METHOD: We applied the three-process model to personality data......-process model. Second, we show that the various response processes show a pattern of correlations across traits and rating sources which is in line with the idea that indifferent and extreme responding are person-specific tendencies, whereas directional responding is content-specific. Third, we report findings...... of N = 577 dyads (self- and observer reports of the HEXACO Personality Inventory-Revised) of Dutch and German respondents. RESULTS: First, we provide evidence that indifferent, directional, and extreme responding can be separated from each other in personality data through the use of the three...

The Mesoscale Science of the Matter-Radiation Interactions in Extremes (MaRIE) project

Energy Technology Data Exchange (ETDEWEB)

Kippen, Karen Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Montoya, Donald Raymond [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-08-17

The National Nuclear Security Administration (NNSA) requires the ability to understand and test how material structures, defects, and interfaces determine performance in extreme environments such as in nuclear weapons. To do this, MaRIE will be an x-ray source that is laser-like and brilliant with very fl exible and fast pulses to see at weapons-relevant time scales, and with high enough energy to study critical materials. The Department of Energy (DOE) has determined there is a mission need for MaRIE to deliver this capability. MaRIE can use some of the existing infrastructure of the Los Alamos Neutron Science Center (LANSCE) and its accelerator capability. MaRIE will be built as a strategic partnership of DOE national laboratories and university collaborators.

A social cybernetic analysis of simulation-based, remotely delivered medical skills training in an austere environment: developing a test bed for spaceflight medicine.

Science.gov (United States)

Musson, David M; Doyle, Thomas E

2012-01-01

This paper describes analysis of medical skills training exercises that were conducted at an arctic research station. These were conducted as part of an ongoing effort to establish high fidelity medical simulation test bed capabilities in remote and extreme "space analogue" environments for the purpose studying medical care in spaceflight. The methodological orientation followed by the authors is that of "second order cybernetics," or the science of studying human systems where the observer is involved within the system in question. Analyses presented include the identification of three distinct phases of the training activity, and two distinct levels of work groups-- termed "first-order teams" and "second-order teams." Depending on the phase of activity, first-order and second-order teams are identified, each having it own unique structure, composition, communications, goals, and challenges. Several specific teams are highlighted as case examples. Limitations of this approach are discussed, as are potential benefits to ongoing and planned research activity in this area.

Test-retest reliability of the Clinical Learning Environment, Supervision and Nurse Teacher (CLES + T) scale.

Science.gov (United States)

Gustafsson, Margareta; Blomberg, Karin; Holmefur, Marie

2015-07-01

The Clinical Learning Environment, Supervision and Nurse Teacher (CLES + T) scale evaluates the student nurses' perception of the learning environment and supervision within the clinical placement. It has never been tested in a replication study. The aim of the present study was to evaluate the test-retest reliability of the CLES + T scale. The CLES + T scale was administered twice to a group of 42 student nurses, with a one-week interval. Test-retest reliability was determined by calculations of Intraclass Correlation Coefficients (ICCs) and weighted Kappa coefficients. Standard Error of Measurements (SEM) and Smallest Detectable Difference (SDD) determined the precision of individual scores. Bland-Altman plots were created for analyses of systematic differences between the test occasions. The results of the study showed that the stability over time was good to excellent (ICC 0.88-0.96) in the sub-dimensions "Supervisory relationship", "Pedagogical atmosphere on the ward" and "Role of the nurse teacher". Measurements of "Premises of nursing on the ward" and "Leadership style of the manager" had lower but still acceptable stability (ICC 0.70-0.75). No systematic differences occurred between the test occasions. This study supports the usefulness of the CLES + T scale as a reliable measure of the student nurses' perception of the learning environment within the clinical placement at a hospital. Copyright © 2015 Elsevier Ltd. All rights reserved.

Perception, Action, and Cognition of Football Referees in Extreme Temperatures: Impact on Decision Performance

Science.gov (United States)

Gaoua, Nadia; de Oliveira, Rita F.; Hunter, Steve

2017-01-01

Different professional domains require high levels of physical performance alongside fast and accurate decision-making. Construction workers, police officers, firefighters, elite sports men and women, the military and emergency medical professionals are often exposed to hostile environments with limited options for behavioral coping strategies. In this (mini) review we use football refereeing as an example to discuss the combined effect of intense physical activity and extreme temperatures on decision-making and suggest an explicative model. In professional football competitions can be played in temperatures ranging from -5°C in Norway to 30°C in Spain for example. Despite these conditions, the referee’s responsibility is to consistently apply the laws fairly and uniformly, and to ensure the rules are followed without waning or adversely influencing the competitiveness of the play. However, strenuous exercise in extreme environments imposes increased physiological and psychological stress that can affect decision-making. Therefore, the physical exertion required to follow the game and the thermal strain from the extreme temperatures may hinder the ability of referees to make fast and accurate decisions. Here, we review literature on the physical and cognitive requirements of football refereeing and how extreme temperatures may affect referees’ decisions. Research suggests that both hot and cold environments have a negative impact on decision-making but data specific to decision-making is still lacking. A theoretical model of decision-making under the constraint of intense physical activity and thermal stress is suggested. Future naturalistic studies are needed to validate this model and provide clear recommendations for mitigating strategies. PMID:28912742

Perception, Action, and Cognition of Football Referees in Extreme Temperatures: Impact on Decision Performance

Directory of Open Access Journals (Sweden)

Nadia Gaoua

2017-08-01

Full Text Available Different professional domains require high levels of physical performance alongside fast and accurate decision-making. Construction workers, police officers, firefighters, elite sports men and women, the military and emergency medical professionals are often exposed to hostile environments with limited options for behavioral coping strategies. In this (mini review we use football refereeing as an example to discuss the combined effect of intense physical activity and extreme temperatures on decision-making and suggest an explicative model. In professional football competitions can be played in temperatures ranging from -5°C in Norway to 30°C in Spain for example. Despite these conditions, the referee’s responsibility is to consistently apply the laws fairly and uniformly, and to ensure the rules are followed without waning or adversely influencing the competitiveness of the play. However, strenuous exercise in extreme environments imposes increased physiological and psychological stress that can affect decision-making. Therefore, the physical exertion required to follow the game and the thermal strain from the extreme temperatures may hinder the ability of referees to make fast and accurate decisions. Here, we review literature on the physical and cognitive requirements of football refereeing and how extreme temperatures may affect referees’ decisions. Research suggests that both hot and cold environments have a negative impact on decision-making but data specific to decision-making is still lacking. A theoretical model of decision-making under the constraint of intense physical activity and thermal stress is suggested. Future naturalistic studies are needed to validate this model and provide clear recommendations for mitigating strategies.

Perception, Action, and Cognition of Football Referees in Extreme Temperatures: Impact on Decision Performance.

Science.gov (United States)

Gaoua, Nadia; de Oliveira, Rita F; Hunter, Steve

2017-01-01

Different professional domains require high levels of physical performance alongside fast and accurate decision-making. Construction workers, police officers, firefighters, elite sports men and women, the military and emergency medical professionals are often exposed to hostile environments with limited options for behavioral coping strategies. In this (mini) review we use football refereeing as an example to discuss the combined effect of intense physical activity and extreme temperatures on decision-making and suggest an explicative model. In professional football competitions can be played in temperatures ranging from -5°C in Norway to 30°C in Spain for example. Despite these conditions, the referee's responsibility is to consistently apply the laws fairly and uniformly, and to ensure the rules are followed without waning or adversely influencing the competitiveness of the play. However, strenuous exercise in extreme environments imposes increased physiological and psychological stress that can affect decision-making. Therefore, the physical exertion required to follow the game and the thermal strain from the extreme temperatures may hinder the ability of referees to make fast and accurate decisions. Here, we review literature on the physical and cognitive requirements of football refereeing and how extreme temperatures may affect referees' decisions. Research suggests that both hot and cold environments have a negative impact on decision-making but data specific to decision-making is still lacking. A theoretical model of decision-making under the constraint of intense physical activity and thermal stress is suggested. Future naturalistic studies are needed to validate this model and provide clear recommendations for mitigating strategies.

Topographical mapping system for radiological and hazardous environments acceptance testing

International Nuclear Information System (INIS)

Armstrong, G.A.; Dochat, G.R.

1997-01-01

During the summer of 1996, the Topographical Mapping System (TMS) for hazardous and radiological environments and its accompanying three-dimensional (3-D) visualization tool, the Interactive Computer-Enhanced Remote-Viewing System (ICERVS), were delivered to Oak Ridge National Laboratory (ORNL). ORNL and Mechanical Technology, Inc., performed final acceptance testing of the TMS during the next eight months. The TMS was calibrated and characterized during this period. This paper covers the calibration, characterization, and acceptance testing of the TMS. Development of the TMS and ICERVS was initiated by the US Department of Energy (DOE) for the purpose of characterization and remediation of underground storage tanks (USTs) at DOE sites across the country. DOE required a 3-D, topographical mapping system suitable for use in hazardous and radiological environments. The intended application is the mapping of the interior of USTs as part of DOE's waste characterization and remediation efforts and to obtain baseline data on the content of the storage tank interiors as well as data on changes in the tank contents and levels brought about by waste remediation steps. Initially targeted for deployment at the Hanford Washington site, the TMS is designed to be a self-contained, compact, and reconfigurable system that is capable of providing rapid, variable-resolution mapping information in poorly characterized workspaces with a minimum of operator intervention

Topographical mapping system for radiological and hazardous environments acceptance testing

Science.gov (United States)

Armstrong, Gary A.; Dochat, G. R.

1997-09-01

During the summer of 1996, the topographical mapping system (TMS) for hazardous and radiological environments and its accompanying three-dimensional (3-D) visualization tool, the interactive computer-enhanced remote-viewing system (ICERVS), were delivered to Oak Ridge National Laboratory (ORNL). ORNL and Mechanical Technology, Inc., performed final acceptance testing of the TMS during the next eight months. The TMS was calibrated and characterized during this period. This paper covers the calibration, characterization, and acceptance testing of the TMS. Development of the TMS and the ICERVS was initiated by the U.S. Department of Energy (DOE) for the purpose of characterization and remediation of underground storage tanks (USTs) at DOE sites across the country. DOE required a 3-D, topographical mapping system suitable for use in hazardous and radiological environments. The intended application is the mapping of the interior of USTs as part of DOE's waste characterization and remediation efforts and to obtain baseline data on the content of the storage tank interiors as well as data on changes in the tank contents and levels brought about by waste remediation steps. Initially targeted for deployment at the Hanford Washington site, the TMS is designed to be a self-contained, compact, reconfigurable system that is capable of providing rapid, variable-resolution mapping information in poorly characterized workspaces with a minimum of operator intervention.

A computational environment for creating and testing reduced chemical kinetic mechanisms

Energy Technology Data Exchange (ETDEWEB)

Montgomery, C.J.; Swensen, D.A.; Harding, T.V.; Cremer, M.A.; Bockelie, M.J. [Reaction Engineering International, Salt Lake City, UT (USA)

2002-02-01

This paper describes software called computer assisted reduced mechanism problem solving environment (CARM-PSE) that gives the engineer the ability to rapidly set up, run and examine large numbers of problems comparing detailed and reduced (approximate) chemistry. CARM-PSE integrates the automatic chemical mechanism reduction code CARM and the codes that simulate perfectly stirred reactors and plug flow reactors into a user-friendly computational environment. CARM-PSE gives the combustion engineer the ability to easily test chemical approximations over many hundreds of combinations of inputs in a multidimensional parameter space. The demonstration problems compare detailed and reduced chemical kinetic calculations for methane-air combustion, including nitrogen oxide formation, in a stirred reactor and selective non-catalytic reduction of NOx, in coal combustion flue gas.

Extremely Preterm Birth

Science.gov (United States)

... Events Advocacy For Patients About ACOG Extremely Preterm Birth Home For Patients Search FAQs Extremely Preterm Birth ... Spanish FAQ173, June 2016 PDF Format Extremely Preterm Birth Pregnancy When is a baby considered “preterm” or “ ...

Critical care at extremes of temperature: effects on patients, staff and equipment.

Science.gov (United States)

Hindle, Elise M; Henning, J D

2014-12-01

Modern travel and military operations have led to a significant increase in the need to provide medical care in extreme climates. Presently, there are few data on what happens to the doctor, their drugs and equipment when exposed to these extremes. A review was undertaken to find out the effects of 'extreme heat or cold' on anaesthesia and critical care; in addition, subject matter experts were contacted directly. Both extreme heat and extreme cold can cause a marked physiological response in a critically ill patient and the doctor treating these patients may also suffer a decrement in both physical and mental functioning. Equipment can malfunction when exposed to extremes of temperature and should ideally be stored and operated in a climatically controlled environment. Many drugs have a narrow range of temperatures in which they remain useable though some have been shown to remain effective if exposed to extremes of temperature for a short period of time. All personnel embarking on an expedition to an extreme temperature zone should be of sufficient physical robustness and ideally should have a period of acclimatisation which may help mitigate against some of the physiological effects of exposure to extreme heat or extreme cold. Expedition planners should aim to provide climatic control for drugs and equipment and should have logistical plans for replenishment of drugs and medical evacuation of casualties. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Measuring risk of crude oil at extreme quantiles

Directory of Open Access Journals (Sweden)

Saša Žiković

2011-06-01

Full Text Available The purpose of this paper is to investigate the performance of VaR models at measuring risk for WTI oil one-month futures returns. Risk models, ranging from industry standards such as RiskMetrics and historical simulation to conditional extreme value model, are used to calculate commodity market risk at extreme quantiles: 0.95, 0.99, 0.995 and 0.999 for both long and short trading positions. Our results show that out of the tested fat tailed distributions, generalised Pareto distribution provides the best fit to both tails of oil returns although tails differ significantly, with the right tail having a higher tail index, indicative of more extreme events. The main conclusion is that, in the analysed period, only extreme value theory based models provide a reasonable degree of safety while widespread VaR models do not provide adequate risk coverage and their performance is especially weak for short position in oil.

SRB thermal protection systems materials test results in an arc-heated nitrogen environment

Science.gov (United States)

Wojciechowski, C. J.

1979-01-01

The external surface of the Solid Rocket Booster (SRB) will experience imposed thermal and shear environments due to aerodynamic heating and radiation heating during launch, staging and reentry. This report is concerned with the performance of the various TPS materials during the staging maneuver. During staging, the wash from the Space Shuttle Main Engine (SSME) exhust plumes impose severe, short duration, thermal environments on the SRB. Five different SRB TPS materials were tested in the 1 MW Arc Plasma Generator (APG) facility. The maximum simulated heating rate obtained in the APG facility was 248 Btu/sq ft./sec, however, the test duration was such that the total heat was more than simulated. Similarly, some local high shear stress levels of 0.04 psia were not simulated. Most of the SSME plume impingement area on the SRB experiences shear stress levels of 0.02 psia and lower. The shear stress levels on the test specimens were between 0.021 and 0.008 psia. The SSME plume stagnation conditions were also simulated.

Tethered Contactless Mobile Nuclear Environment Monitoring Robot

International Nuclear Information System (INIS)

Choi, S. Y.; Lee, E. S.; Lee, Kun J.; Kim, Su H.; Rim, C. T.

2013-01-01

In fact, the nuclear environment monitoring is significantly crucial for early detection of NPP accident, radiological emergency, the estimation of radiation exposure to nearby residents as well as the long term radioactivity. In the UAE, the nuclear environment monitoring is, however, quite challenging because sampling locations are far from NPPs and the outdoor temperature and humidity are very high for NPP workers to collect soil, air, and water samples. Therefore, nuclear environment monitoring robots (Nubos) are strongly needed for the NPPs in the UAE. The Nubos can be remotely controlled to collect samples in extreme environment instead of NPP workers. Moreover, the Nubos can be unmanned ground vehicles (UGVs), unmanned aerial vehicles (UAVs) and unmanned marine vehicles (UMVs) to collect soil, air, and water samples, respectively. In this paper, the prototype development of UGV type Nubos using power cable for a long distance power delivery, called Tethered contactless mobile Nubo is introduced and validated by experiments. In this paper, the prototype development of Tethered Contactless Mobile (TeCoM) Nubo, which can be powered continuously within several km distance and avoid tangled cable, and the indoor test are finished. As further works, outdoor demonstration and a grand scale R and D proposal of practical Nubo will be proceeded

Tethered Contactless Mobile Nuclear Environment Monitoring Robot

Energy Technology Data Exchange (ETDEWEB)

Choi, S. Y.; Lee, E. S.; Lee, Kun J.; Kim, Su H.; Rim, C. T. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2013-05-15

In fact, the nuclear environment monitoring is significantly crucial for early detection of NPP accident, radiological emergency, the estimation of radiation exposure to nearby residents as well as the long term radioactivity. In the UAE, the nuclear environment monitoring is, however, quite challenging because sampling locations are far from NPPs and the outdoor temperature and humidity are very high for NPP workers to collect soil, air, and water samples. Therefore, nuclear environment monitoring robots (Nubos) are strongly needed for the NPPs in the UAE. The Nubos can be remotely controlled to collect samples in extreme environment instead of NPP workers. Moreover, the Nubos can be unmanned ground vehicles (UGVs), unmanned aerial vehicles (UAVs) and unmanned marine vehicles (UMVs) to collect soil, air, and water samples, respectively. In this paper, the prototype development of UGV type Nubos using power cable for a long distance power delivery, called Tethered contactless mobile Nubo is introduced and validated by experiments. In this paper, the prototype development of Tethered Contactless Mobile (TeCoM) Nubo, which can be powered continuously within several km distance and avoid tangled cable, and the indoor test are finished. As further works, outdoor demonstration and a grand scale R and D proposal of practical Nubo will be proceeded.

SiC Sensors in Extreme Environments: Real-time Hydrogen Monitoring for Energy Plant Applications

Science.gov (United States)

Ghosh, Ruby

2008-03-01

Clean, efficient energy production, such as the gasification of coal (syngas), requires physical and chemical sensors for exhaust gas monitoring as well as real-time control of the combustion process. Wide-bandgap semiconducting materials systems can meet the sensing demands in these extreme environments consisting of chemically corrosive gases at high temperature and pressure. We have developed a SiC based micro-sensor for detection of hydrogen containing species with millisecond response at 600 C. The sensor is a Pt-SiO2-SiC device with a dense Pt catalytic sensing film, capable of withstanding months of continuous high temperature operation. The device was characterized in robust sensing module that is compatible with an industrial reactor. We report on the performance of the SiC sensor in a simulated syngas ambient at 370 C containing the common interferants CO2, CH4 and CO [1]. In addition we demonstrate that hours of exposure to >=1000 ppm H2S and 15% water vapor does not degrade the sensor performance. To elucidate the mechanisms responsible for the hydrogen response of the sensor we have modeled the hydrogen adsorptions kinetics at the internal Pt-SiO2 interface, using both the Tempkin and Langmuir isotherms. Under the conditions appropriate for energy plant applications, the response of our sensor is significantly larger than that obtained from ultra-high vacuum electrochemical sensor measurements at high temperatures. We will discuss the role of morphology, at the nano to micro scale, on the enhanced catalytic activity observed for our Pt sensing films in response to a heated hydrogen gas stream at atmospheric pressure. [1] R. Loloee, B. Chorpening, S. Beers & R. Ghosh, Hydrogen monitoring for power plant applications using SiC sensors, Sens. Actuators B:Chem. (2007), doi:10.1016/j.snb.2007.07.118

The Relationship Between Lower Extremity Wingate Anaerobic Test (WAnT and 50m Freestyle Swimming Performance

Directory of Open Access Journals (Sweden)

Ayşegül YAPICI

2015-07-01

Full Text Available The aim of this study is to analyze the relationship between 50mt freestyle swimming performance and lower extremity Wingate anaerobic power and capacity test. 11 male (age: 13.45 ± 1.0 3 years, height: 166.18 ± 10.12 cm, weight: 55.00 ± 11.13 kg, experience: 6.2 ± 1.1 years swimmers participated in this study voluntarily. The players participated in anthropometric measurements followed by Wingate anaerobic test on the first day. They p erformed 50mt freestyle swimming performance tests on the second day (one days later. In this study, 50mt freestyle swimming performance has not been done from a standart jump. All the swimmers started their performance in the water with a 2 - leg - ged push away from the wall. Also 10mt lap periods were recorded. Data were expressed as mean ± standard deviation. Correlation between anaerobic performance tests and swimming performance tests were studied with Pearson correlation analysis. All analysis were exec uted in SPSS 17.0 and the statistical significance was set at p 0.05. The statistically s ignificant relationship between f atigue index and relative average power, relative minumum peak power and minumum peak power (p0.05. On looking at the relationship between the 10 mt lap period time in swimming and wingate anaerobic test performance, a statistically s ignificant relationship between both relative and absolute values maximum swimming speed and paek power, average speed swimming and average power, minimum swimming speed and minumum power (p0.05. The factors like experience, the level of profession, the difference of fricton between activities in water and land, air conditions (moisture, temperature may have effected the re sults.

Committee VI.1. Extreme Hull Girder Loading

DEFF Research Database (Denmark)

Jensen, Jørgen Juncher

2000-01-01

Committee Mandate. Evaluate and develop direct calculation procedures for extreme wawe loads on ship hull girders. Due consideration shall be given to stochastic and non-linear effects. The procedures shall be assessed by comparison with in-service experiences, model tests and more refined...

Political extremism predicts belief in conspiracy theories

NARCIS (Netherlands)

van Prooijen, J.W.; Krouwel, A.P.M.; Pollet, T. V.

2015-01-01

Historical records suggest that the political extremes—at both the “left” and the “right”—substantially endorsed conspiracy beliefs about other-minded groups. The present contribution empirically tests whether extreme political ideologies, at either side of the political spectrum, are positively

Bias and spread in extreme value theory measurements of probability of error

Science.gov (United States)

Smith, J. G.

1972-01-01

Extreme value theory is examined to explain the cause of the bias and spread in performance of communications systems characterized by low bit rates and high data reliability requirements, for cases in which underlying noise is Gaussian or perturbed Gaussian. Experimental verification is presented and procedures that minimize these effects are suggested. Even under these conditions, however, extreme value theory test results are not particularly more significant than bit error rate tests.

Mapping the Far Right: Geomedia in an Educational Response to Right-Wing Extremism

Directory of Open Access Journals (Sweden)

Thomas Jekel

2017-09-01

Full Text Available Across Europe, and probably the world, messages of the extreme right surface with increasing and alarming regularity in both public and virtual space. Within the virtual space, geomedia are increasingly used in nationalist propaganda, a trend which is embedded in a wider development in public discourse, election results, and policies. In Austria and Germany, particular sensibilities due to the responsibility for the Holocaust have developed, leading to various specific education initiatives that address this part of history. This paper presents an activist learning environment using geomedia to deconstruct right-wing extremist discourses, and has been tested used in university settings in Salzburg and Vienna. Using a combination of Instagram and geospatial technologies not visible to learners, results of reflection and learning processes are analyzed qualitatively across two slightly different enactments of the learning environment. Experiences suggest an encouraging potential of geomedia use in critical learning processes, as long as the technology is hidden from learners, forming an incentive, support, and contextualization of the learning process.

Geodetic antenna calibration test in the Antarctic environment

Science.gov (United States)

Grejner-Brzezinska, A.; Vazquez, E.; Hothem, L.

2006-01-01

TransAntarctic Mountain DEFormation (TAMDEF) Monitoring Network is the NSF-sponsored OSU and USGS project, aimed at measuring crustal motion in the Transantarctic Mountains of Victoria Land using GPS carrier phase measurements. Station monumentation, antenna mounts, antenna types, and data processing strategies were optimized to achieve mm-level estimates for the rates of motion. These data contributes also to regional Antarctic frame definition. Significant amount of data collected over several years allow the investigation of unique aspects of GPS geodesy in Antarctica, to determine how the error spectrum compares to the mid-latitude regions, and to identify the optimum measurement and data processing schemes for Antarctic conditions, in order to test the predicted rates of motion (mm-level w.r.t. time). The data collection for the TAMDEF project was initiated in 1996. The primary antenna used has been the Ashtech L1/L2 Dorne Margolin (D/M) choke ring. A few occupations involved the use of a Trimble D/M choke ring. The data were processed using the antenna calibration data available from the National Geodetic Survey (NGS). The recent developments in new antenna designs that are lighter in weight and lower in cost are being considered as a possible alternative to the bulkier and more expensive D/M choke ring design. In November 2003, in situ testing of three alternative models of L1/L2 antennas was conducted at a site located in the vicinity of McMurdo Station, Antarctica (S77.87, E166.56). The antenna models used in this test were: Ashtech D/M choke ring, Trimble D/M choke ring, Trimble Zephyr, and the NovAtel GPS-702. Two stations, spaced within 30 meters, were used in the test. Both had the characteristics similar to the stations of the TAMDEF network, i.e., the UNAVCO fixed-height, force-centered level mounts with a constant antenna offset were used, ensuring extreme stability of the antenna/ mount/pin set up. During each of the four 3-day test data collection

Bioprospecting Archaea: Focus on Extreme Halophiles

KAUST Repository

Antunes, André

2016-12-12

In 1990, Woese et al. divided the Tree of Life into three separate domains: Eukarya, Bacteria, and Archaea. Archaea were originally perceived as little more than “odd bacteria” restricted to extreme environmental niches, but later discoveries challenged this assumption. Members of this domain populate a variety of unexpected environments (e.g. soils, seawater, and human bodies), and we currently witness ongoing massive expansions of the archaeal branch of the Tree of Life. Archaea are now recognized as major players in the biosphere and constitute a significant fraction of the earth’s biomass, yet they remain underexplored. An ongoing surge in exploration efforts is leading to an increase in the (a) number of isolated strains, (b) associated knowledge, and (c) utilization of Archaea in biotechnology. They are increasingly employed in fields as diverse as biocatalysis, biocomputing, bioplastic production, bioremediation, bioengineering, food, pharmaceuticals, and nutraceuticals. This chapter provides a general overview on bioprospecting Archaea, with a particular focus on extreme halophiles. We explore aspects such as diversity, ecology, screening techniques and biotechnology. Current and future trends in mining for applications are discussed.

Cognitive evaluation for the diagnosis of Alzheimer's disease based on Turing Test and Virtual Environments.

Science.gov (United States)

Fernandez Montenegro, Juan Manuel; Argyriou, Vasileios

2017-05-01

Alzheimer's screening tests are commonly used by doctors to diagnose the patient's condition and stage as early as possible. Most of these tests are based on pen-paper interaction and do not embrace the advantages provided by new technologies. This paper proposes novel Alzheimer's screening tests based on virtual environments and game principles using new immersive technologies combined with advanced Human Computer Interaction (HCI) systems. These new tests are focused on the immersion of the patient in a virtual room, in order to mislead and deceive the patient's mind. In addition, we propose two novel variations of Turing Test proposed by Alan Turing as a method to detect dementia. As a result, four tests are introduced demonstrating the wide range of screening mechanisms that could be designed using virtual environments and game concepts. The proposed tests are focused on the evaluation of memory loss related to common objects, recent conversations and events; the diagnosis of problems in expressing and understanding language; the ability to recognize abnormalities; and to differentiate between virtual worlds and reality, or humans and machines. The proposed screening tests were evaluated and tested using both patients and healthy adults in a comparative study with state-of-the-art Alzheimer's screening tests. The results show the capacity of the new tests to distinguish healthy people from Alzheimer's patients. Copyright © 2017. Published by Elsevier Inc.

Testing of CFC replacement fluids for arc-induced toxic by-products

Energy Technology Data Exchange (ETDEWEB)

Cravey, W.R.; Goerz, D.A.; Hawley-Fedder, R.A.

1993-06-01

The authors have developed a unique test-stand for quantifying the generation of perfluoroisobutylene (PFIB) in chlorofluorocarbon (CFC) replacement fluids when they are subjected to high electrical stress/breakdown environments. PFIB is an extremely toxic gas with a threshold limit value of 10 ppbv as set by the American Conference of Governmental Industrial Hygienists. They have tested several new fluids from various manufacturers for their potential to generate PFIB. Their goal is to determine breakdown characteristics and quantify toxic by-products of these replacement fluids to determine a safe, usable alternative for present CFC`s.

An overview on extremity dosimetry in medical applications

International Nuclear Information System (INIS)

Vanhavere, F.; Carinou, E.; Donadille, L.; Ginjaume, M.; Jankowski, J.; Rimpler, A.; Sans Merce, M.

2008-01-01

Some activities of EURADOS Working Group 9 (WG9) are presently funded by the European Commission (CONRAD project). The objective of WG9 is to promote and co-ordinate research activities for the assessment of occupational exposures to staff at workplaces in interventional radiology (IR) and nuclear medicine. For some of these applications, the skin of the fingers is the limiting organ for individual monitoring of external radiation. Therefore, sub-group 1 of WG9 deals with the use of extremity dosemeters in medical radiation fields. The wide variety of radiation field characteristics present in a medical environment together with the difficulties in measuring a local dose that is representative for the maximum skin dose, usually with one single detector, makes it difficult to perform accurate extremity dosimetry. Sub-group 1 worked out a thorough literature review on extremity dosimetry issues in diagnostic and therapeutic nuclear medicine and positron emission tomography, interventional radiology and interventional cardiology and brachytherapy. Some studies showed that the annual dose limits could be exceeded if the required protection measures are not taken, especially in nuclear medicine. The continuous progress in new applications and techniques requires an important effort in radiation protection and training. (authors)

The Relation Between Visual Impairment and Extremity Fractures

Directory of Open Access Journals (Sweden)

Berrak Şekeryapan

2013-08-01

Full Text Available Purpose: To evaluate the association between the development of extremity fracture and visual impairment in adults. Material and Method: This study included 56 patients (patient group aged 18 years or older who had extremity fractures due to a fall. The control group (n=42 was selected from visitors who had regular medical check-ups at our hospital. Each participant underwent a full ophthalmologic examination. Mean age was compared by Student’s t test. The other variables were compared by chi-square test. Results: The prevalence of subjects with visual impairment was significantly higher in the patients group (78.6% than in the control group (38.1% (p<0.05. The prevalence of treatable eye diseases such as cataract and refractive errors were significantly higher in the patient group than in the control group (p<0.05 for both. Twenty-eight patients (50% in the patient group and 8 subjects in the control group had visual acuities lower than 0.5 (p<0.05. Discussion: We have found that the prevalence of visual impairment was significantly higher in adults with extremity fractures due to falls than in the control group. Hence, we believe that regular ophthalmological examination in adults, providing regular use of eyeglasses in patients with refractive errors, and timely treatment of treatable eye diseases such as cataract could decrease the extremity fractures from falls in adults. (Turk J Ophthalmol 2013; 43: 250-2

Extreme value theory in emerging markets

Directory of Open Access Journals (Sweden)

Anđelić Goran

2010-01-01

Full Text Available This paper investigates the performance of extreme value theory (EVT with the daily stock index returns of four different emerging markets. The research covers the sample representing the Serbian (BELEXline, Croatian (CROBEX, Slovenian (SBI20, and Hungarian (BUX stock indexes using the data from January 2006 - September 2009. In the paper a performance test was carried out for the success of application of the extreme value theory in estimating and forecasting of the tails of daily return distribution of the analyzed stock indexes. Therefore the main goal is to determine whether EVT adequately estimates and forecasts the tails (2.5% and 5% at the tail of daily stock index return distribution in the emerging markets of Serbia, Croatia, Slovenia, and Hungary. The applied methodology during the research includes analysis, synthesis and statistical/mathematical methods. Research results according to estimated Generalized Pareto Distribution (GPD parameters indicate the necessity of applying market risk estimation methods, i.e. extreme value theory (EVT in the framework of a broader analysis of investment processes in emerging markets.

Gray QB-sing-faced version 2 (SF2) open environment test report

Energy Technology Data Exchange (ETDEWEB)

Plummer, J. [Savannah River Site (SRS), Aiken, SC (United States); Immel, D. [Savannah River Site (SRS), Aiken, SC (United States); Bobbitt, J. [Savannah River Site (SRS), Aiken, SC (United States); Negron, M. [Savannah River Site (SRS), Aiken, SC (United States)

2015-02-16

This report details the design upgrades incorporated into the new version of the GrayQbTM SF2 device and the characterization testing of this upgraded device. Results from controlled characterization testing in the Savannah River National Laboratory (SRNL) R&D Engineering Imaging and Radiation Lab (IRL) and the Savannah River Site (SRS) Health Physics Instrument Calibration Laboratory (HPICL) is presented, as well as results from the open environment field testing performed in the E-Area Low Level Waste Storage Area. Resultant images presented in this report were generated using the SRNL developed Radiation Analyzer (RAzerTM) software program which overlays the radiation contour images onto the visual image of the location being surveyed.

Methodology for featuring and assessing extreme climatic events

International Nuclear Information System (INIS)

Malleron, N.; Bernardara, P.; Benoit, M.; Parey, S.; Perret, C.

2013-01-01

The setting up of a nuclear power plant on a particular site requires the assessment of risks linked to extreme natural events like flooding or earthquakes. As a consequence of the Fukushima accident EDF proposes to take into account even rarer events in order to improve the robustness of the facility all over its operating life. This article presents the methodology used by EDF to analyse a set of data in a statistical way in order to extract extreme values. This analysis is based on the theory of extreme values and is applied to the extreme values of the flow rate in the case of a river overflowing. This methodology is made of 6 steps: 1) selection of the event, of its featuring parameter and of its probability, for instance the question is what is the flow rate of a flooding that has a probability of 10 -3 to happen, 2) to collect data over a long period of time (or to recover data from past periods), 3) to extract extreme values from the data, 4) to find an adequate statistical law that fits the spreading of the extreme values, 5) the selected statistical law must be validated through visual or statistical tests, and 6) the computation of the flow rate of the event itself. (A.C.)

Using Upper Extremity Skin Temperatures to Assess Thermal Comfort in Office Buildings in Changsha, China.

Science.gov (United States)

Wu, Zhibin; Li, Nianping; Cui, Haijiao; Peng, Jinqing; Chen, Haowen; Liu, Penglong

2017-09-21

Existing thermal comfort field studies are mainly focused on the relationship between the indoor physical environment and the thermal comfort. In numerous chamber experiments, physiological parameters were adopted to assess thermal comfort, but the experiments' conclusions may not represent a realistic thermal environment due to the highly controlled thermal environment and few occupants. This paper focuses on determining the relationships between upper extremity skin temperatures (i.e., finger, wrist, hand and forearm) and the indoor thermal comfort. Also, the applicability of predicting thermal comfort by using upper extremity skin temperatures was explored. Field studies were performed in office buildings equipped with split air-conditioning (SAC) located in the hot summer and cold winter (HSCW) climate zone of China during the summer of 2016. Psychological responses of occupants were recorded and physical and physiological factors were measured simultaneously. Standard effective temperature (SET*) was used to incorporate the effect of humidity and air velocity on thermal comfort. The results indicate that upper extremity skin temperatures are good indicators for predicting thermal sensation, and could be used to assess the thermal comfort in terms of physiological mechanism. In addition, the neutral temperature was 24.7 °C and the upper limit for 80% acceptability was 28.2 °C in SET*.

Using Upper Extremity Skin Temperatures to Assess Thermal Comfort in Office Buildings in Changsha, China

Directory of Open Access Journals (Sweden)

Zhibin Wu

2017-09-01

Full Text Available Existing thermal comfort field studies are mainly focused on the relationship between the indoor physical environment and the thermal comfort. In numerous chamber experiments, physiological parameters were adopted to assess thermal comfort, but the experiments’ conclusions may not represent a realistic thermal environment due to the highly controlled thermal environment and few occupants. This paper focuses on determining the relationships between upper extremity skin temperatures (i.e., finger, wrist, hand and forearm and the indoor thermal comfort. Also, the applicability of predicting thermal comfort by using upper extremity skin temperatures was explored. Field studies were performed in office buildings equipped with split air-conditioning (SAC located in the hot summer and cold winter (HSCW climate zone of China during the summer of 2016. Psychological responses of occupants were recorded and physical and physiological factors were measured simultaneously. Standard effective temperature (SET* was used to incorporate the effect of humidity and air velocity on thermal comfort. The results indicate that upper extremity skin temperatures are good indicators for predicting thermal sensation, and could be used to assess the thermal comfort in terms of physiological mechanism. In addition, the neutral temperature was 24.7 °C and the upper limit for 80% acceptability was 28.2 °C in SET*.

Mechanosensitivity during lower extremity neurodynamic testing is diminished in individuals with Type 2 Diabetes Mellitus and peripheral neuropathy: a cross sectional study

Directory of Open Access Journals (Sweden)

Boyd Benjamin S

2010-08-01

Full Text Available Abstract Background Type 2 Diabetes Mellitus (T2DM and diabetic symmetrical polyneuropathy (DSP impact multiple modalities of sensation including light touch, temperature, position sense and vibration perception. No study to date has examined the mechanosensitivity of peripheral nerves during limb movement in this population. The objective was to determine the unique effects T2DM and DSP have on nerve mechanosensitivity in the lower extremity. Methods This cross-sectional study included 43 people with T2DM. Straight leg raise neurodynamic tests were performed with ankle plantar flexion (PF/SLR and dorsiflexion (DF/SLR. Hip flexion range of motion (ROM, lower extremity muscle activity and symptom profile, intensity and location were measured at rest, first onset of symptoms (P1 and maximally tolerated symptoms (P2. Results The addition of ankle dorsiflexion during SLR testing reduced the hip flexion ROM by 4.3° ± 6.5° at P1 and by 5.4° ± 4.9° at P2. Individuals in the T2DM group with signs of severe DSP (n = 9 had no difference in hip flexion ROM between PF/SLR and DF/SLR at P1 (1.4° ± 4.2°; paired t-test p = 0.34 or P2 (0.9° ± 2.5°; paired t-test p = 0.31. Movement induced muscle activity was absent during SLR with the exception of the tibialis anterior during DF/SLR testing. Increases in symptom intensity during SLR testing were similar for both PF/SLR and DF/SLR. The addition of ankle dorsiflexion induced more frequent posterior leg symptoms when taken to P2. Conclusions Consistent with previous recommendations in the literature, P1 is an appropriate test end point for SLR neurodynamic testing in people with T2DM. However, our findings suggest that people with T2DM and severe DSP have limited responses to SLR neurodynamic testing, and thus may be at risk for harm from nerve overstretch and the information gathered will be of limited clinical value.

Development of a system for simultaneously generating triple extreme conditions for neutron scattering experiments

Energy Technology Data Exchange (ETDEWEB)

Ichimura, Shigeju [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-10-01

We have developed new system available for controlling sample environment during the neutron scattering experiments. The system can simultaneously generate triple extreme conditions of low temperature, high magnetic field and high pressure. The system consists of : (1) a liquid-helium cryostat which enables the sample temperature range of 1.7 K to 200 K, (2) a superconducting magnet providing a vertical field up to 5 Tesla with antisymmetric split-coil geometry for polarized-beam experiments, and (3) a non-magnetic clamping high-pressure cell designed with the aim of generating hydrostatic pressure up to 2.5 Gpa. In the workshop, we will report the outline of the system and some results of performance tests using the system at JRR-3M of JAERI. (author)

Sialyte(TM)-Based Composite Pressure Vessels for Extreme Environments, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — While traveling to Venus, electronics and instruments go through enormous pressure, temperature, and atmospheric environment changes. In the past, this has caused...

Influence of Test Section Geometry on the Blast Environment in an Explosively Driven Conical Shock Tube

Science.gov (United States)

2018-03-30

ARL-TR-8335•MAR 2018 US Army Research Laboratory Influence of Test Section Geometry on theBlast Environment in an Explosively DrivenConical Shock...ARL-TR-8335•MAR 2018 US Army Research Laboratory Influence of Test Section Geometry on theBlast Environment in an Explosively DrivenConical Shock...TITLE AND SUBTITLE    5a. CONTRACT NUMBER  5b. GRANT NUMBER  5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S)    5d.  PROJECT  NUMBER  5e. TASK NUMBER  5f

Orion Exploration Flight Test Reaction Control System Jet Interaction Heating Environment from Flight Data

Science.gov (United States)

White, Molly E.; Hyatt, Andrew J.

2016-01-01

The Orion Multi-Purpose Crew Vehicle (MPCV) Reaction Control System (RCS) is critical to guide the vehicle along the desired trajectory during re-­-entry. However, this system has a significant impact on the convective heating environment to the spacecraft. Heating augmentation from the jet interaction (JI) drives thermal protection system (TPS) material selection and thickness requirements for the spacecraft. This paper describes the heating environment from the RCS on the afterbody of the Orion MPCV during Orion's first flight test, Exploration Flight Test 1 (EFT-1). These jet plumes interact with the wake of the crew capsule and cause an increase in the convective heating environment. Not only is there widespread influence from the jet banks, there may also be very localized effects. The firing history during EFT-1 will be summarized to assess which jet bank interaction was measured during flight. Heating augmentation factors derived from the reconstructed flight data will be presented. Furthermore, flight instrumentation across the afterbody provides the highest spatial resolution of the region of influence of the individual jet banks of any spacecraft yet flown. This distribution of heating augmentation across the afterbody will be derived from the flight data. Additionally, trends with possible correlating parameters will be investigated to assist future designs and ground testing programs. Finally, the challenges of measuring JI, applying this data to future flights and lessons learned will be discussed.

Properties of Extreme Precipitation and Their Uncertainties in 3-year GPM Precipitation Radar Data

Science.gov (United States)

Liu, N.; Liu, C.

2017-12-01

Extreme high precipitation rates are often related to flash floods and have devastating impacts on human society and the environments. To better understand these rare events, 3-year Precipitation Features (PFs) are defined by grouping the contiguous areas with nonzero near-surface precipitation derived using Global Precipitation Measurement (GPM) Ku band Precipitation Radar (KuPR). The properties of PFs with extreme precipitation rates greater than 20, 50, 100 mm/hr, such as the geographical distribution, volumetric precipitation contribution, seasonal and diurnal variations, are examined. In addition to the large seasonal and regional variations, the rare extreme precipitation rates often have a larger contribution to the local total precipitation. Extreme precipitation rates occur more often over land than over ocean. The challenges in the retrieval of extreme precipitation might be from the attenuation correction and large uncertainties in the Z-R relationships from near-surface radar reflectivity to precipitation rates. These potential uncertainties are examined by using collocated ground based radar reflectivity and precipitation retrievals.

An overview of environment Canada's National Incinerator Testing and Evaluation Program (NITEP)

International Nuclear Information System (INIS)