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Sample records for 10exp 5 torr

  1. A vacuum (10(exp -9) Torr) friction apparatus for determining friction and endurance life of MoSx films

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa; Honecy, Frank S.; Abel, Phillip B.; Pepper, Stephen V.; Spalvins, Talivaldis; Wheeler, Donald R.

    1992-01-01

    The first part of this paper describes an ultrahigh vacuum friction apparatus (tribometer). The tribometer can be used in a ball-on-disk configuration and is specifically designed to measure the friction and endurance life of solid lubricating films such as MoS(x) in vacuum at a pressure of 10 exp -7 Pa. The sliding mode is typically unidirectional at a constant rotating speed. The second part of this paper presents some representative friction and endurance life data for magnetron sputtered MoS(x) films (110 nm thick) deposited on sputter-cleaned 440 C stainless-steel disk substrates, which were slid against a 6-mm-diameter 440 C stainless-steel bearing ball. All experiments were conducted with loads of 0.49 to 3.6 N (average Hertzian contact pressure, 0.33 to 0.69 GPa), at a constant rotating speed of 120 rpm (sliding velocity ranging from 31 to 107 mm/s due to the range of wear track radii involved in the experiments), in a vacuum of 7 x 10 exp -7 Pa and at room temperature. The results indicate that there are similarities in friction behavior of MoS(x) films overs their life cycles regardless of load applied. The coefficient of friction (mu) decreases as load W increases according to mu = kW exp -1/3. The endurance life E of MoS(x) films decreases as the load W increases according to E = KW exp -1.4 for the load range. The load- (or contract-pressure-) dependent endurance life allows us to reduce the time for wear experiments and to accelerate endurance life testing of MoS(x) films. For the magnetron-sputtered MoS(x) films deposited on 440 C stainless-steel disks: the specific wear rate normalized to the load and the number of revolutions was 3 x 10 exp -8 mm exp 3/N-revolution; the specific wear rate normalized to the load and the total sliding distance was 8 x 10 exp -7 mm exp 3/N-m; and the nondimensional wear coefficient of was approximately 5 x 10 exp -6. The values are almost independent of load in the range 0.49 to 3.6 N (average Hertzian contact

  2. Laboratory Demonstration of Phase Induced Amplitude Apodization (PIAA) Coronagraph with Better than 10(exp -9) Contrast

    NASA Technical Reports Server (NTRS)

    Kern, Brian; Guyon, Olivier; Kuhnert, Andreas; Niessner, Albert; Martinache, Frantz; Balasubramanian, Kunjithapatham

    2013-01-01

    We present coronagraphic images from the Phase Induced Amplitude Apodization (PIAA) coronagraph on NASA's High Contrast Imaging Testbed (HCIT) at the Jet Propulsion Lab, showing contrasts of 5x10(exp -1) averaged from 2-4 lambda/D, in monochromatic light at 808 nm. In parallel with the coronagraph and its deformable mirror and coronagraphic wavefront control, we also demonstrate a low-order wavefront control system, giving 100 x rms suppression of introduced tip/tilt disturbances down to residual levels of 10(exp -3) lambda/D. Current limitations, as well as broadband (10% fractional bandpass) preliminary results are discussed.

  3. Heat-Transfer and Pressure Measurements from a Flight Test of the Third 1/18-Scale Model of the Titan Intercontinental Ballistic Missile up to a Mach Number of 3.86 and Reynolds Number per Foot of 23.5 x 10(exp 6) and a Comparison with Heat Transfer

    NASA Technical Reports Server (NTRS)

    Graham, John B., Jr.

    1958-01-01

    Heat-transfer and pressure measurements were obtained from a flight test of a 1/18-scale model of the Titan intercontinental ballistic missile up to a Mach number of 3.86 and Reynolds number per foot of 23.5 x 10(exp 6) and are compared with the data of two previously tested 1/18-scale models. Boundary-layer transition was observed on the nose of the model. Van Driest's theory predicted heat-transfer coefficients reasonably well for the fully laminar flow but predictions made by Van Driest's theory for turbulent flow were considerably higher than the measurements when the skin was being heated. Comparison with the flight test of two similar models shows fair repeatability of the measurements for fully laminar or turbulent flow.

  4. Enhanced low-temperature CO oxidation on a stepped platinum surface for oxygen pressures above 10(-5) Torr.

    PubMed

    Lewis, Henry D; Burnett, Daniel J; Gabelnick, Aaron M; Fischer, Daniel A; Gland, John L

    2005-11-24

    The rate of CO oxidation has been characterized on the stepped Pt(411) surface for oxygen pressures up to 0.002 Torr, over the 100-1000 K temperature range. CO oxidation was characterized using both temperature-programmed reaction spectroscopy (TPRS) and in situ soft X-ray fluorescence yield near-edge spectroscopy (FYNES). New understanding of the important role surface defects play in accelerating CO oxidation for oxygen pressure above 10(-5) Torr is presented in this paper for the first time. For saturated monolayers of CO, the oxidation rate increases and the activation energy decreases significantly for oxygen pressures above 10(-5) Torr. This enhanced CO oxidation rate is caused by a change in the rate-limiting step to a surface reaction limited process above 10(-5) Torr oxygen from a CO desorption limited process at lower oxygen pressure. For example, in oxygen pressures above 0.002 Torr, CO(2) formation begins at 275 K even for the CO saturated monolayer, which is well below the 350 K onset temperature for CO desorption. Isothermal kinetic measurements in flowing oxygen for this stepped surface indicate that activation energies and preexponential factors depend strongly on oxygen pressure, a factor that has not previously been considered critical for CO oxidation on platinum. As oxygen pressure is increased from 10(-6) to 0.002 Torr, the oxidation activation energies for the saturated CO monolayer decrease from 24.1 to 13.5 kcal/mol for reaction over the 0.95-0.90 ML CO coverage range. This dramatic decrease in activation energy is associated with a simple increase in oxygen pressure from 10(-5) to 10(-3) Torr. Activation energies as low as 7.8 kcal/mol were observed for oxidation of an initially saturated CO layer reacting over the 0.4-0.25 ML coverage range in oxygen pressure of 0.002 Torr. These dramatic changes in reaction mechanism with oxygen pressure for stepped surfaces are consistent with mechanistic models involving transient low activation energy

  5. Space and time structure of helium pulsed surface-wave discharges at intermediate pressures (5-50 Torr)

    NASA Astrophysics Data System (ADS)

    Hamdan, Ahmad; Valade, Fabrice; Margot, Joëlle; Vidal, François; Matte, Jean-Pierre

    2017-01-01

    In this paper, the ignition and development of a plasma created by pulsed surface wave discharges (PSWDs) was experimentally investigated using time-resolved imaging techniques and optical spectroscopy in helium at intermediate gas pressures between 5 and 50 Torr. We found that the ionization front moves at a few km s-1 during the ignition phase and decreases to hundreds of m s-1 after only some tens of µs. Once the plasma has reached a sufficient length, a standing wave pattern is observed in the light emission of the discharge. We attribute its formation to the reflection of the surface wave on the ionization front, which results in a pattern of nodes and antinodes. We have also determined the time and space evolution of the gas temperature. It is shown that the gas temperature increases from the room temperature value to a plateau at several hundreds of degrees over a short time (typically 100 µs). These results supports those obtained by light emission imaging and also show that the standing wave pattern does not affect the gas temperature.

  6. An Instrument to Measure Elemental Energy Spectra of Cosmic Ray Nuclei Up to 10(exp 16) eV

    NASA Technical Reports Server (NTRS)

    Adams, J.; Bashindzhagyan, G.; Chilingarian, A.; Drury, L.; Egorov, N.; Golubkov,S.; Korotkova, N.; Panasyuk, M.; Podorozhnyi, D.; Procqureur, J.

    2000-01-01

    A longstanding goal of cosmic ray research is to measure the elemental energy spectra of cosmic rays up to and through the "knee" (approx. equal to 3 x 10 (exp 15) eV. It is not currently feasible to achieve this goal with an ionization calorimeter because the mass required to be deployed in Earth orbit is very large (at least 50 tonnes). An alternative method will be presented. This is based on measuring the primary particle energy by determining the angular distribution of secondaries produced in a target layer using silicon microstrip detector technology. The proposed technique can be used over a wide range of energies (10 (exp 11)- 10 (exp 16) eV) and gives an energy resolution of 60% or better. Based on this technique, a design for a new lightweight instrument with a large aperture (KLEM) will be described.

  7. A direct gravitational lensing test for 10 exp 6 solar masses black holes in halos of galaxies

    NASA Technical Reports Server (NTRS)

    Wambsganss, Joachim; Paczynski, Bohdan

    1992-01-01

    We propose a method that will be able to detect or exclude the existence of 10 exp 6 solar masses black holes in the halos of galaxies. VLBA radio maps of two milliarcsecond jets of a gravitationally lensed quasar will show the signature of these black holes - if they exist. If there are no compact objects in this mass range along the line of sight, the two jets should be linear mappings of each other. If they are not, there must be compact objects of about 10 exp 6 solar masses in the halo of the galaxy that deform the images by gravitational deflection. We present numerical simulations for the two jets A and B of the double quasar 0957 + 561, but the method is valid for any gravitationally lensed quasar with structure on milliarcsecond scales. As a by-product from high-quality VLBA maps of jets A and B, one will be able to tell which features in the maps are intrinsic in the original jet and which are only an optical illusion, i.e., gravitational distortions by black holes along the line of sight.

  8. Heat Transfer and Boundary-Layer Transition on a Highly Polished Hemisphere-Cone in Free Flight at Mach Numbers Up to 3.14 and Reynolds Numbers Up to 24 x 10(exp 6)

    NASA Technical Reports Server (NTRS)

    Buglia, James J.

    1961-01-01

    A highly polished hemisphere-cone having a ratio of nose radius to base radius of 0.74 and a half-angle of 14.5 was flight tested at Mach numbers up to 4.70. Temperature and pressure data were obtained at Mach numbers up to 3.14 and a free-stream Reynolds number of 24 x 10(exp 6) based on body diameter. The nose of the model had a surface roughness of 2 to 5 microinches as measured with an interferometer. The measured Stanton numbers were in good agreement with theory. Transition Reynolds numbers based on the laminar boundary-layer momentum thickness at transition ranged from 2,190 to 794. Comparison with results from previous tests of blunt shapes having a surface roughness of 20 to 40 microinches showed that the high degree of polish was instrumental in delaying the transition from laminar to turbulent flow.

  9. Study of the Reaction Cl + Ethyl Formate at 700-950 Torr and 297 to 435 K: Product Distribution and the Kinetics of the Reaction C2H5OC(═O) → CO2 + C2H5.

    PubMed

    Kaiser, E W

    2016-05-26

    The kinetics and mechanism of the reaction of atomic chlorine with ethyl formate [Cl + CH3CH2O(C═O)H, reaction 1] have been examined. These experiments were performed at pressures of 760-950 Torr and temperatures from 297 to 435 K. Reactants and products were quantified by gas chromatography-flame ionization detector (GC/FID) analysis. The initial mixture contained ethyl formate, Cl2, and N2. Cl atoms were generated by UV photolysis of this initial mixture at 360 nm, which dissociates Cl2. The rate constant of reaction 1 was measured at 297 K relative to that of the reaction Cl + C2H5Cl (reaction 2), yielding the rate constant ratio k1/k2 = 1.09 ± 0.05. The final products formed from reaction 1 are ethyl chloroformate, 1-chloroethyl formate, and 2-chloroethyl formate. These products result from the reactions with Cl2 of the three free radicals formed by H atom abstraction from ethylformate in reaction 1. Based on the molar yields of these three chlorinated products, the yields of the three radicals formed from reaction 1 at 297 K are (25 ± 3) mole percent of CH3CH2O(C═O); (67 ± 5) mole percent of CH3CHO(C═O)H; and (8 ± 2) mole percent of CH2CH2O(C═O)H. A second phase of this experiment measured the rate constant of the decarboxylation of the ethoxy carbonyl radical [CH3CH2O(C═O) → CO2 + C2H5, reaction 4] relative to the rate constant of its reaction with Cl2 [CH3CH2O(C═O) + Cl2 → CH3CH2O(C═O)Cl + Cl, reaction 3a]. Over the temperature range 297 to 404 K at 1 atm total pressure, this ratio can be expressed by k4/k3a = 10(23.56±0.22) e(-(12700±375)/RT) molecules cm(-3). Estimating the value of k3a (which has not been measured) based on similar reactions, the expression k4 = 5.8 × 10(12) e(-(12700)/RT) s(-1) is obtained. The estimated error of this rate constant is ± a factor of 2 over the experimental temperature range. This rate expression is compared with recent ab initio calculations of the decarboxylation of the analogous methoxy

  10. Depression and diabetes in the remote Torres Strait Islands.

    PubMed

    Taylor, Sean; McDermott, Robyn; Thompson, Fintan; Usher, Kim

    2016-07-20

    Issue addressed: Diabetes is associated with significant depression, which can result in poorer clinical outcomes, including increased mortality. Little is known about the prevalence of depression among Torres Strait Islander adults with diabetes.Methods: Self-reported depression was measured using the Patient Health Questionnaire (PHQ)-9 translated into Torres Strait Creole, and associations with socioeconomic, behavioural and clinical indicators in Torres Strait Islander adults with diabetes in five remote Torres Strait Islands were examined.Results: Seventy-three men and 115 women completed interviews. The median PHQ-9 score was 5.5 (IQR 0-7); 42% of respondents scored 0-4 (none-minimal), 46% scored 5-9 (mild) and 12% scored 10+ (moderate-severe). Mean HbA1c was 8.3% (67.4mmol). HbA1c was not related to PHQ-9 scores (β=0.20, P=0.323), however exercise in hours (β=-0.34, P<0.001) and screen time in hours (β=0.11, P<0.001) were significant predictors of depression after adjusting for other study variables.Conclusions: This sample of remote living Torres Strait Islanders reported relatively low rates of depression compared with national samples, and depression was not related to glycaemic control. Exercise and screen time were the strongest predictors of depression based on PHQ-9 scores. This represents an opportunity for health promotion.So what?: These findings provide an indication of the health impact of physical activity in rural and remote communities. Local health and education services, councils and sporting bodies should work collaboratively to promote sustainable physical activity programs.

  11. The Rate Constant for the Reaction H + C2H5 at T = 295 - 150K

    NASA Technical Reports Server (NTRS)

    Pimentel, Andre S.; Payne, Walter A.; Nesbitt, Fred L.; Cody, Regina J.; Stief, Louis J.

    2004-01-01

    The reaction between the hydrogen atom and the ethyl (C2H3) radical is predicted by photochemical modeling to be the most important loss process for C2H5 radicals in the atmospheres of Jupiter and Saturn. This reaction is also one of the major sources for the methyl radicals in these atmospheres. These two simplest hydrocarbon radicals are the initial species for the synthesis of larger hydrocarbons. Previous measurements of the rate constant for the H + C2H5 reaction varied by a factor of five at room temperature, and some studies showed a dependence upon temperature while others showed no such dependence. In addition, the previous studies were at higher temperatures and generally higher pressures than that needed for use in planetary atmospheric models. The rate constant for the reaction H + C2H5 has been measured directly at T = 150, 202 and 295 K and at P = 1.0 Torr He for all temperatures and additionally at P = 0.5 and 2.0 Torr He at T = 202 K. The measurements were performed in a discharge - fast flow system. The decay of the C2H5 radical in the presence of excess hydrogen was monitored by low-energy electron impact mass spectrometry under pseudo-first order conditions. H atoms and C2H5 radicals were generated rapidly and simultaneously by the reaction of fluorine atoms with H2 and C2H6, respectively. The total rate constant was found to be temperature and pressure independent. The measured total rate constant at each temperature are: k(sub 1)(295K) = (1.02+/-0.24)x10(exp -10), k(sub 1)(202K) = (1.02+/-0.22)x10(exp -10) and k(sub 1)(150K) = (0.93+/-0.21)x10(exp -10), all in units of cu cm/molecule/s. The total rate constant derived from all the combined measurements is k(sub 1) = (l.03+/-0.17)x10(exp -10) cu cm/molecule/s. At room temperature our results are about a factor of two higher than the recommended rate constant and a factor of three lower than the most recently published study.

  12. The net water circulation through Torres strait

    NASA Astrophysics Data System (ADS)

    Wolanski, Eric; Lambrechts, Jonathan; Thomas, Christopher; Deleersnijder, Eric

    2013-08-01

    The extensive existing data set on the oceanography of Torres Strait (separating Australia and Papua New Guinea) is reviewed and is used to show that the long-term east to west water flux through Torres Strait is about 0.04 Sv. To explain this finding, a high resolution, finite element, depth-integrated (2D) model of Torres Strait is set-up. The model is driven by the wind and the open boundary conditions that are prescribed in the Coral Sea, the northern Great Barrier Reef continental shelf, the Gulf of Papua, and the Gulf of Carpentaria. The latter/open boundary conditions were taken from field data. The model suggests that the wind alone over Torres Strait generates negligible net currents; the net currents are instead generated by the wind setting up a water slope across Torres Strait through its opposing influence on the mean sea levels in the Gulf of Carpentaria and in the Coral Sea. The model predicts that the long-term, net east-west flow through Torres Strait is small to negligible, in agreement with field data. The model also reveals that large scale flow dynamics are largely restricted to reef passages and open waters, and that areas of shallow waters and areas densely populated with reefs and islands are poorly flushed. Finally, the model also reveals the prevalence of highly energetic tidal flows around shoals, reefs, islands and reef passages, and these swift tidal currents are responsible for the small net flow through Torres Strait through the sticky water effect. These findings enable us to propose a general water circulation model for the whole Great Barrier Reef during southeast winds.

  13. Hemostatic factors in Australian Aboriginal and Torres Strait Islander populations.

    PubMed

    Wang, Zaimin; Rowley, Kevin; Best, James; McDermott, Robyn; Taylor, Michael; O'Dea, Kerin

    2007-05-01

    Hemostatic processes are important in precipitating myocardial infarction and stroke. Elevated plasma fibrinogen is considered a risk factor for cardiovascular diseases (CVDs), but the results of previous studies on the association of plasma factor VIIc activity with CVD and diabetes have been inconsistent. The aim of the present study was to explore the association of plasma fibrinogen and factor VIIc to clinical characteristics and estimated coronary heart disease (CHD) risk in Aboriginal and Torres Strait Islander peoples. Cross-sectional surveys of Australian Aboriginal people (n = 852) and Torres Strait Islanders (n = 276) aged 15 years and older were conducted from 1993 to 1995. Anthropometric characteristics, blood pressure, fasting plasma fibrinogen, factor VIIc, total and high-density lipoprotein cholesterol, triglycerides, and glucose were measured. Levels of fibrinogen (mean, 95% confidence interval) for Aboriginal (3.52, 3.44-3.59 g/L) and Torres Strait Islander people (3.62, 3.49-3.75 g/L) were higher compared with previous reports from other populations. Factor VIIc (mean, 95% confidence interval) was especially high in Torres Strait Islanders (116%, 111%-122%) compared with Aboriginal people (99%, 97%-102%). Fibrinogen increased with age in both ethnic groups and sexes. Fibrinogen was independently associated with female sex, body mass index, renal dysfunction, low levels of high-density lipoprotein cholesterol and diabetes, whereas the independent predictors for factor VIIc were Torres Strait Islander ethnicity, female sex, body mass index, renal dysfunction, and total cholesterol. Average fibrinogen levels were high (>3.5 mg/dL) even for people considered "below average risk of coronary heart disease" according to conventional risk factor levels. For Aboriginal women, levels of fibrinogen and factor VIIc were significantly higher for persons at high risk than those at below average risk. The data suggest that plasma fibrinogen and factor VIIc might

  14. Preliminary Investigation of Molybdenum Disulfide-air-mist Lubrication for Roller Bearings Operating to DN Values of 1 x 10(exp 6) and Ball Bearings Operating to Temperatures of 1000 F

    NASA Technical Reports Server (NTRS)

    Macks, E F; Nemeth, Z N; Anderson, W J

    1951-01-01

    The effectiveness of molybdenum disulfide MoS2 as a bearing lubricant was determined at high temperature and at high speeds. A 1-inch-bore ball bearing operated at temperatures to 1000 F, a speed of 1725 rpm, and a thrust load of 20 pounds when lubricated only with MoS2-air mist. A 75-millimeter-bore cageless roller bearing, provided with a MoS2-syrup coating before operation, operated at DN values to 1 x 10(exp 6) with a load of 368 pounds.

  15. Spatially Controlled Fe Isotope Variations at Torres del Paine

    NASA Astrophysics Data System (ADS)

    Gajos, N.; Lundstrom, C.

    2013-12-01

    Recent advances in mass-spectrometry have identified systematic trends of non-traditional stable isotope variation in igneous rocks with differentiation index. We present new Fe isotope data for the Torres del Paine igneous complex in southern Chile. The multi-composition pluton consists of a 1 km vertical exposure of homogenous granite overlying a contemporaneous and possibly cogenetic 0.5 km mafic gabbro suite. Whereas previous isotopic investigations do little to address variations across important magmatic contacts, this study focuses on a first-of-its-kind spatially dependent non-traditional stable isotope investigation of an igneous pluton. Samples were collected at Torres del Paine in spatially significant transects, focusing on major contacts between country rock, granite and mafic units. Results collected by bracketed double spike MC-ICP-MS (2s precision of ×0.03) show an increase in δ56Fe towards the high silica margins of the pluton with values as high as δ56Fe 0.36. Additionally, the data show a decrease in δ56Fe toward the mafic center of the pluton with δ56Fe values ranging from δ56Fe -0.05 to 0.18. Samples collected on the contact between the granite and mafic complex show intermediate values of δ56Fe= 0.18(×) 0.03. Country rock samples in contact with granite show an isotopically light signature of δ56Fe=0.04 (×) 0.03. Analysis of 50 samples in total show a trend of increasing δ56Fe with SiO2 content. The process responsible for Fe isotope variations remains debated but is suggested to reflect four mechanisms: (1) crustal assimilation, (2) fractional crystallization, (3) late stage fluid exsolution [1] and (4) thermal migration [3]. Preliminary results show that mechanisms #1 and #2 would produce isotopic signatures opposite of those seen at Torres del Paine and other plutonic rocks. Isotopically light Torres country rock samples reveal that assimilation of rocks would not produce the isotopically heavy granites seen at Torres. Based on

  16. Jaime Torres Bodet: Centenario de su Natalicio (Jaime Torres Bodet: 100th Anniversary of His Birth).

    ERIC Educational Resources Information Center

    Revista Interamericana de Educacion de Adultos, 2002

    2002-01-01

    Articles in this issue, written in Spanish, focus on the following: the philosophy of Jaime Torres Bodet (humanistic vision of adult education; objectives of public education in Mexico; Mexico and the issue of culture; The Mexican National Museum of History; Enrique Gonzalez Martinez, poet of all hours; Marti, Cuba's champion; educational…

  17. Measurements of Local Heat Transfer and Pressure on Six 2-Inch-Diameter Blunt Bodies at a Mach Number of 4.95 and at Reynolds Numbers Per Foot up to 81 x 10(exp 6)

    NASA Technical Reports Server (NTRS)

    Cooper, Morton; Mayo, Edward E.

    1959-01-01

    Measurements of the local heat transfer and pressure distribution have been made on six 2-inch-diameter, blunt, axially symmetric bodies in the Langley gas dynamics laboratory at a Mach number of 4.95 and at Reynolds numbers per foot up to 81 x 10(exp 6). During the investigation laminar flow was observed over a hemispherical-nosed body having a surface finish from 10 to 20 microinches at the highest test Reynolds number per foot (for this configuration) of 77.4 x 10(exp 6). Though it was repeatedly possible to measure completely laminar flow at this Reynolds number for the hemisphere, it was not possible to observe completely laminar flow on the flat-nosed body for similar conditions. The significance of this phenomenon is obscured by the observation that the effects of particle impacts on the surface in causing roughness were more pronounced on the flat-nosed body. For engineering purposes, a method developed by M. Richard Dennison while employed by Lockheed Aircraft Corporation appears to be a reasonable procedure for estimating turbulent heat transfer provided transition occurs at a forward location on the body. For rearward-transition locations, the method is much poorer for the hemispherical nose than for the flat nose. The pressures measured on the hemisphere agreed very well with those of the modified Newtonian theory, whereas the pressures on all other bodies, except on the flat-nosed body, were bracketed by modified Newtonian theory both with and without centrifugal forces. For the hemisphere, the stagnation-point velocity gradient agreed very well with Newtonian theory. The stagnation-point velocity gradient for the flat- nosed model was 0.31 of the value for the hemispherical-nosed model. If a Newtonian type of flow is assumed, the ratio 0.31 will be independent of Much number and real-gas effects.

  18. Calculational and Experimental Investigations of the Pressure Effects on Radical - Radical Cross Combinations Reactions: C2H5 + C2H3

    NASA Technical Reports Server (NTRS)

    Fahr, Askar; Halpern, Joshua B.; Tardy, Dwight C.

    2007-01-01

    of C-C and C-H bond ruptures, cyclization, decyclization, and complex decompositions are discussed in terms of energetics and structural properties. The pressure dependence of the product yields were computed and dominant reaction paths in this chemically activated system were determined. Both modeling and experiment suggest that the observed pressure dependence of [1-C4H8]/[C4H10] is due to decomposition of the chemically activated combination adduct 1-C4H8* in which the weaker allylic C-C bond is broken: H2C=CHCH2CH3 yields C3H5 + CH3. This reaction occurs even at moderate pressures of approx.200 Torr (26 kPa) and becomes more significant at lower pressures. The additional products detected at lower pressures are formed from secondary radical-radical reactions involving allyl, methyl, ethyl, and vinyl radicals. The modeling studies have extended the predictions of product distributions to different temperatures (200-700 K) and a wider range of pressures (10(exp -3) - 10(exp 5) Torr). These calculations indicate that the high-pressure [1-C4H8]/[C4H10] yield ratio is 1.3 +/- 0.1.

  19. Intellectual Disability in Australia's Aboriginal and Torres Strait Islander Peoples

    ERIC Educational Resources Information Center

    Journal of Intellectual & Developmental Disability, 2007

    2007-01-01

    In mid-2001, the Aboriginal and Torres Strait Islander population in Australia was approximately 458,500 people (2.4% of the national population). Aboriginal and Torres Strait Islander peoples in Australia experience disadvantage compared to non-Indigenous Australians in a number of areas, including greater prevalence of health risk factors, early…

  20. Modeling of the initiation and evolution of a laser-ionized column in the lower atmosphere - 314.5 nm wavelength resonant multiphoton ionization of naturally occurring argon

    NASA Technical Reports Server (NTRS)

    Fetzer, G. J.; Stockley, J. E.

    1992-01-01

    A 3+1 resonant multiphoton ionization process in naturally occurring argon is studied at 314.5 nm as a candidate for providing a long ionized channel through the atmosphere. Results are presented which indicate peak electron densities up to 10 exp 8/cu cm can be created using laser intensities on the order of 10 exp 8 W/sq cm.

  1. The role of immunohistochemistry in the Muir-Torre Syndrome*

    PubMed Central

    Oliveira, Cláudia Marina Puga Barbosa; de Campos, Jullyene Gomes; Maia, Maiko Ramacos; Lobo, Larissa Eva dos Santos; do Valle, Fábio Francesconi

    2015-01-01

    Muir-Torre Syndrome is defined by the coexistence of sebaceous skin tumors and internal malignancies. Mutations in the DNA mismatch repair genes are found in the inherited form of the disease, resulting in the absence of crucial enzymes involved with DNA replication process. This case describes a patient with sebaceous adenoma and colorectal carcinoma, meeting the criteria for Muir-Torre Syndrome. The immunohistochemical analysis of the skin lesion was an important tool to confirm the diagnosis, as it revealed nuclear negativity for MSH2 and MSH6. PMID:26312706

  2. Vaccine preventable diseases and vaccination coverage in Aboriginal and Torres Strait Islander people, Australia 2006-2010.

    PubMed

    Naidu, Latika; Chiu, Clayton; Habig, Andrew; Lowbridge, Christopher; Jayasinghe, Sanjay; Wang, Han; McIntyre, Peter; Menzies, Robert

    2013-12-31

    This report outlines the major positive impacts of vaccines on the health of Aboriginal and Torres Strait Islander people from 2007 to 2010, as well as highlighting areas that require further attention. Hepatitis A disease is now less common in Aboriginal and Torres Strait Islander children than in their non-Indigenous counterparts. Hepatitis A vaccination for Aboriginal and Torres Strait Islander children was introduced in 2005 in the high incidence jurisdictions of the Northern Territory, Queensland, South Australia and Western Australia. In 2002–2005, there were 20 hospitalisations for hepatitis A in Aboriginal and Torres Strait Islander children aged<5 years--over 100 times more common than in other children--compared to none in 2006/07–2009/10. With respect to invasive pneumococcal disease (IPD), there has been a reduction of 87% in notifications of IPD caused by serotypes contained in 7-valent pneumococcal conjugate vaccine (7vPCV) since the introduction of the childhood 7vPCV program among Aboriginal and Torres Strait Islander children. However, due to a lower proportion of IPD caused by 7vPCV types prior to vaccine introduction, the decline in total IPD notifications has been less marked in Aboriginal and Torres Strait Islander children than in other children. Higher valency vaccines (10vPCV and 13vPCV) which replaced 7vPCV from 2011 are likely to result in a greater impact on IPD and potentially also non-invasive disease, although disease caused by non-vaccine serotypes appears likely to be an ongoing problem. Among Aboriginal and Torres Strait Islander people aged ≥50 years, there have been recent increases in IPD, which appear related to low vaccination coverage and highlight the need for improved coverage in this high-risk target group. Since routine meningococcal C vaccination for infants and the high-school catch-up program were implemented in 2003, there has been a significant decrease in cases caused by serogroup C. However, the predominant

  3. The dwarf saltwort (Salicornia bigelovii Torr.): Evaluation of breeding populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Breeding populations of the dwarf saltwort (Salicornia bigelovii Torr. [Chenopodiaceae]) have been evaluated under high seawater salinity (45 dS m-1) for phenotypic, morphometric, biomass and seed traits in an effort to select suitable families and genotypes within families for breeding purposes and...

  4. Kapua Gutchen: Educator, Mentor and Innovator of Torres Strait Islander Music, Dance and Language at Erub (Darnley Island), Torres Strait

    ERIC Educational Resources Information Center

    Costigan, Lyn; Neuenfeldt, Karl

    2011-01-01

    The contributions of local community members to Indigenous education can be an important component in curriculum programs. This article explores the contributions of one such dedicated and talented Torres Strait Islander community member: Meuram tribal elder Kapua Gutchen. He teaches at the Erub (Darnley Island) Campus of Tagai College in the…

  5. Social determinants and psychological distress among Aboriginal and Torres Strait islander adults in the Australian state of Victoria: a cross-sectional population based study.

    PubMed

    Markwick, Alison; Ansari, Zahid; Sullivan, Mary; McNeil, John

    2015-03-01

    Aboriginal and Torres Strait Islander adults in the Australian state of Victoria have a higher prevalence of psychological distress than their non-Aboriginal and Torres Strait Islander counterparts. We sought to explain this inequality, focussing on the social determinants of health. We used population-based survey data from the 2008 Victorian Population Health Survey; a cross-sectional landline computer-assisted telephone survey of 34,168 randomly selected adults. We defined psychological distress as a score of 22 or more on the Kessler 10 Psychological Distress scale. We used logistic regression to identify socio-demographic characteristics and social capital indicators that were associated with psychological distress. We then created multivariable models to explore the association between psychological distress and Aboriginal and Torres Strait Islander status that incorporated all significant socioeconomic status (SES) and social capital variables, adjusting for all non-SES socio-demographic characteristics. Aboriginal and Torres Strait Islander Victorians (24.5%) were more than twice as likely than their non-Aboriginal and Torres Strait Islander counterparts (11.3%) to have psychological distress (odds ratio (OR) = 2.56, 95% confidence interval; 1.67-3.93). Controlling for SES, negative perceptions of the residential neighbourhood, lack of social support from family, social and civic distrust, and all non-SES socio-demographic variables (age, sex, marital status, household composition, and rurality), rendered the previously statistically significant inequality in the prevalence of psychological distress, between Aboriginal and Torres Strait Islander Victorians and their non-Aboriginal and Torres Strait Islander counterparts, insignificant at the p = 0.05 level (OR = 1.50; 0.97-2.32). Psychological distress is an important health risk factor for Aboriginal and Torres Strait Islander adults that has yet to be widely acknowledged and addressed. Addressing the

  6. Improving the Bevatron vacuum to 10/sup -10/ torr

    SciTech Connect

    Avery, R.; Elioff, T.; Grunder, H.

    1981-03-01

    Pressure of approx. 10/sup -10/ torr is needed in the Bevatron to accelerate partially-stripped very-heavy ions (e.g. U/sup 69 +/) in the Bevatron without significant loss due to interactions with the residual gas. This ultra-high vacuum will be achieved by installing (summer and fall 1981) a cryogenic liner, mostly 12/sup 0/K, surrounding the Bevatron circulating beam. The novel construction features are presented along with results from successful tests of prototype sections. This is believed to be the largest application of cryogenic pumping to particle accelerators yet undertaken.

  7. Driver licensing: descriptive epidemiology of a social determinant of Aboriginal and Torres Strait Islander health

    PubMed Central

    Hunter, Kate; Clapham, Kathleen; Helps, Yvonne; Senserrick, Teresa; Byrne, Jake; Martiniuk, Alexandra; Daniels, John; Harrison, James E.

    2016-01-01

    Abstract Objective: Education, employment and equitable access to services are commonly accepted as important underlying social determinants of health. For most Australians, access to health, education and other services is facilitated by private transport and a driver licence. This study aimed to examine licensing rates and predictors of licensing in a sample of Aboriginal and Torres Strait Islander people, as these have previously been poorly described. Methods: Interviewer‐administered surveys were conducted with 625 people 16 years or older in four Aboriginal Community Controlled Health Services in New South Wales and South Australia over a two‐week period in 2012–2013. Results: Licensing rates varied from 51% to 77% by site. Compared to not having a licence, having a driver licence was significantly associated with higher odds of full‐time employment (adjusted OR 4.0, 95%CI 2.5–6.3) and educational attainment (adjusted OR 1.9, 95%CI 1.2–2.8 for trade or certificate; adjusted OR 4.0, 95%CI 1.6–9.5 for degree qualification). Conclusions: Variation in driver licensing rates suggests different yet pervasive barriers to access. There is a strong association between driver licensing, education and employment. Implications: Licensing inequality has far‐reaching impacts on the broader health and wellbeing of Aboriginal and Torres Strait Islander people, reinforcing the need for appropriate and accessible pathways to achieving and maintaining driver licensing. PMID:27481274

  8. Bedload parting in western Torres Strait, northern Australia

    NASA Astrophysics Data System (ADS)

    Daniell, James J.

    2015-02-01

    This paper presents a new style of bedload parting from western Torres Strait, northern Australia. Outputs from a hydrodynamic model identified an axis of bedload parting centred on the western Torres Strait islands (~142°15‧E). This bedload parting is similar to others documented from mixed tidal regimes as it is driven dominantly by the O1, K1 and M2 tidal constituents. However, parting is aided by overtides on the eastern, mixed semidiurnal side of the strait. Bedload parting is also strongly impacted by wind-driven currents. Wind-driven currents during the trade wind season lead to the average estimates of bedload transport to be directed west, through the strait, over the 8 year model duration. As a result, east and west directed bedload parting is only active during the monsoon season when the influence of wind-driven circulation is negligible. A simulation of bedload transport using a range of sediment grain sizes indicated that sediments with a grainsize greater than ~2 mm were transported in a direction consistent with tidally driven bedload parting, as opposed to residual wind-driven flow.

  9. An innovative nurse education program in the Torres Strait Islands.

    PubMed

    Usher, Kim; Lindsay, David; Mackay, Wendy

    2005-08-01

    As the most numerous and geographically dispersed professional group, registered nurses in Australia work with Aboriginal and Torres Strait Islander health workers and other members of the multidisciplinary team in a variety of practice contexts to provide health care to Indigenous and non-Indigenous people. Despite the introduction of a variety of recruitment and proactive support strategies by employers, universities and State and Commonwealth governments, few Indigenous people in Australia enrol in, and graduate from, entry level higher education courses in the health professions. The reasons for this are complex and, as yet, not well understood or described; however, it is clear that the well-documented execrable health status of Indigenous Australians demands a response from universities, which are largely responsible for the education of health professionals. An innovative model of registered nurse education in the Torres Strait region of Australia is reported in this paper. A satellite campus established by James Cook University (JCU) on Thursday Island delivers the undergraduate nursing course by mixed mode, supplemented by specific strategies designed to improve Indigenous student recruitment and retention and thus increase the likelihood of graduation. The course and the strategies implemented are discussed in this paper.

  10. Torres strait islanders and Australian nationhood: Some educational perspectives

    NASA Astrophysics Data System (ADS)

    Williamson, Alan

    1992-01-01

    This article analyses the role of education in incorporating Australia's Melanesian minority, the Torres Strait Islanders, into the Australian nation. The analysis begins with the introduction of Queensland government schooling into Torres Strait in 1892, which fostered expectations of Queensland citizenship and employment opportunities available to other races in the economy of the Strait. From 1904 to the outbreak of world war II in the Pacific in 1942 these early directions were altered by educational policies which initially sought to train Islanders for a life in the Islands as a "race apart" from the rest of Australia. Subsequent syllabus reforms, paralleling but not equalling regular schooling offered in Queensland, did not meet Islanders' aspirations for "proper schooling" and the jobs they expected would flow from it. Following world war II, regulations confining Islanders to the Strait were relaxed and many migrated to the Queensland mainland in search of better jobs, better pay, and better education for their children. Those who remained in the Islands received an education which, by 1985, had been brought up to the mainland standard. Yet, neither group's educational aspirations were satisfied despite initiatives and financial incentives of the Commonwealth government aimed at keeping Islander children at school. The article concludes that the way ahead for Islanders in staking out their educational future in the Australian nation on a basis of equality with other Australians lies in educational developments in the Islands themselves, where Islanders are playing an active role in developing, managing, and guiding schooling in directions which recognise their identity and their citizenship aspirations.

  11. Tests to Reduce TorreCat™ Technology to Practice

    SciTech Connect

    Westover, Tyler; Emerson, Rachel Marie

    2016-02-26

    Torrefaction is the thermal treatment of materials in the absence of oxygen in the temperature range of 200 to 300 °C and has been shown to improve handling and grinding properties, hydrophobicity, volatiles content, energy density, and combustion performance of renewable energy biomass feedstock materials. The disadvantages of torrefaction are its relative high cost compared to the low value input feedstock material and the energy that can be lost to volatized gases. This work will demonstrate a new technology developed by Advanced Torrefaction Systems (ATS), known as TorreCat™ Technology, that uses an oxidation catalyst in a closed system to combust and destroy volatile organic compounds (VOCs) and other byproducts produced in the torrefaction process. An oxidation catalyst is a substance, or a combination of substances, that accelerate the rate of a chemical reaction without being consumed by the reaction. Catalytic combustion is a reaction that occurs at temperatures 50% lower than traditional combustion, such that essentially no NOx is created. The output of the oxidation catalyst (flue gas) consists mainly of superheated steam and inert gases (carbon dioxide and nitrogen), which can be used for heat in the thermal treatment process. INL has previously developed a pilot-scale Continuous-Feed Thermal Treatment System (CFTTS) that has 10 kg/hr capacity but does not reform the flue gas to reduce environmental concerns or capture all available heat from the biomass material. Using the TorreCat™ technology in INL’s thermal treatment system will demonstrate increased thermal efficiencies during the treatment process as well as reduced environmental impact and clean-up costs. The objective of this project is to determine the effectiveness of the Torrecat™ technology to reform the flue gas and capture as much of its heat content as possible.

  12. Effective Teaching Practices for Aboriginal and Torres Strait Islander Students: A Review of the Literature

    ERIC Educational Resources Information Center

    Lloyd, Natalie J.; Lewthwaite, Brian Ellis; Osborne, Barry; Boon, Helen J.

    2015-01-01

    This paper presents a review of the literature pertaining to the teacher actions that influence Aboriginal and/or Torres Strait Islander student learning outcomes. This review investigates two foci: the identification of teacher actions influencing learning outcomes for Aboriginal and/or Torres Strait Islander students and the methodological…

  13. Improving the Participation and Engagement of Aboriginal and Torres Strait Islander Students in Business Education

    ERIC Educational Resources Information Center

    Dang, Thi Kim Anh; Vitartas, Peter; Ambrose, Kurt; Millar, Hayley

    2016-01-01

    Most Australian universities have among their goals to increase the number of Aboriginal and Torres Strait Islander students at their institutions. In the Australian higher education context, Aboriginal and Torres Strait Islander students are seriously under-represented, particularly in business education compared to other disciplines. An…

  14. 76 FR 66968 - Abelardo E. Lecompte-Torres, M.D. Decision and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-28

    ... Enforcement Administration Abelardo E. Lecompte-Torres, M.D. Decision and Order On April 29, 2010, the Deputy... Show Cause to Abelardo E. Lecompte-Torres, M.D. (Respondent), of Ponce, Puerto Rico. The Show Cause... well as 28 CFR 0.100(b) and 0.104, I order that the pending application by Abelardo E....

  15. 25 CFR 162.602 - Cabazon, Augustine, and Torres-Martinez Reservations, California.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Cabazon, Augustine, and Torres-Martinez Reservations... Torres-Martinez Reservations, California. (a) Upon a determination by the Secretary that the owner or...-Martinez Indian Reservations which are or may be irrigated from distribution facilities administered by...

  16. 25 CFR 162.502 - Cabazon, Augustine, and Torres-Martinez Reservations, California.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Cabazon, Augustine, and Torres-Martinez Reservations... Torres-Martinez Reservations, California. (a) Upon a determination by the Secretary that the owner or...-Martinez Indian Reservations which are or may be irrigated from distribution facilities administered by...

  17. 25 CFR 162.502 - Cabazon, Augustine, and Torres-Martinez Reservations, California.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Cabazon, Augustine, and Torres-Martinez Reservations... Torres-Martinez Reservations, California. (a) Upon a determination by the Secretary that the owner or...-Martinez Indian Reservations which are or may be irrigated from distribution facilities administered by...

  18. 25 CFR 162.502 - Cabazon, Augustine, and Torres-Martinez Reservations, California.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Cabazon, Augustine, and Torres-Martinez Reservations... Torres-Martinez Reservations, California. (a) Upon a determination by the Secretary that the owner or...-Martinez Indian Reservations which are or may be irrigated from distribution facilities administered by...

  19. 25 CFR 162.502 - Cabazon, Augustine, and Torres-Martinez Reservations, California.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Cabazon, Augustine, and Torres-Martinez Reservations... Torres-Martinez Reservations, California. (a) Upon a determination by the Secretary that the owner or...-Martinez Indian Reservations which are or may be irrigated from distribution facilities administered by...

  20. High precision ages from the Torres del Paine Intrusion, Chile

    NASA Astrophysics Data System (ADS)

    Michel, J.; Baumgartner, L.; Cosca, M.; Ovtcharova, M.; Putlitz, B.; Schaltegger, U.

    2006-12-01

    The upper crustal bimodal Torres del Paine Intrusion, southern Chile, consists of the lower Paine-Mafic- Complex and the upper Paine-Granite. Geochronologically this bimodal complex is not well studied except for a few existing data from Halpern (1973) and Sanchez (2006). The aim of this study is to supplement the existing data and to constrain the age relations between the major magmatic pulses by applying high precision U-Pb dating on accessory zircons and 40Ar/39Ar-laser-step-heating-ages on biotites from the Torres del Paine Intrusion. The magmatic rocks from mafic complex are fine to medium-grained and vary in composition from quartz- monzonites to granodiorites and gabbros. Coarse-grained olivine gabbros have intruded these rocks in the west. The granitic body is represented by a peraluminous, biotite-orthoclase-granite and a more evolved leucocratic granite in the outer parts towards the host-rock. Field observations suggest a feeder-zone for the granite in the west and that the granite postdates the mafic complex. Two granite samples of the outermost margins in the Northeast and South were analyzed. The zircons were dated by precise isotope-dilution U-Pb techniques of chemically abraded single grains. The data are concordant within the analytical error and define weighted mean 206/238U ages of 12.59 ± 0.03 Ma and 12.58 ± 0.01 Ma for the two samples respectively. A 40Ar/39Ar-age for the second sample yield a date of 12.37 ± 0.11 Ma. Three 40Ar/39Ar -ages of biotites were obtained for rocks belonging to the mafic complex. A hbl-bio- granodiorite from the central part, approximately 150 m below the subhorizontal contact with the granite, gives an age of 12.81 ± 0.11 Ma. A hbl-bio-granodiorite and an olivine-gabbro west of the feeder-zone date at 12.42 ± 0.14 Ma and 12.49 ± 0.11 Ma, respectively. The obtained older age of 12.81 Ma for the granodiorite in the central part is consistent with structural relationships of brittle fracturing of the mafic

  1. An Atomic Clock with 10 (exp -18) Instability

    DTIC Science & Technology

    2013-09-13

    from the effects of strong initial density fluctuations in quench up experi ments and finite temperature (20). The space time dependence of the...experimental tools to address exciting topics in cosmology and gravitational physics such as Hawking radiation (13) or Unruh effect (27). References...3.2 x 10- 16/y’t (red solid lile). The blue dashed line represents the estimated combined instabiliy contributions from the Dick effect (1.4 x 10-16

  2. Diagnostic error: what Muir-Torre syndrome has taught us

    PubMed Central

    Hackett, Caitriona Bridget; Healy, Vourneen; Ramsay, Bart

    2015-01-01

    A low-grade sebaceous carcinoma was excised from a 55-year-old woman's neck. At follow-up, 11 months later, a recent diagnosis of mucinous adenocarcinoma of the colon and history of clear cell endometrial carcinoma were identified. A strong family history of bowel cancer suggested Muir-Torre syndrome. Unexpectedly, hereditary non-polyposis colorectal cancer had previously been genetically confirmed; the results were found loosely filed in the paper chart. The patient had not informed us about her diagnosis; having discussed the case with other physicians she felt the diagnosis would be common knowledge. In 1999, US National Institute of Medicine estimated that preventable medical error resulted in the deaths of 44–98 000 people yearly in US hospitals. Four categories of medical error, including diagnosis, treatment, preventive and ‘other’ were described, while the reasoning processes that result in these errors are outlined by Reason et al. We utilise this rare case to illustrate these important concepts. PMID:25795746

  3. Reconciling Mixed Methods Approaches with a Community Narrative Model for Educational Research Involving Aboriginal and Torres Strait Islander Families

    ERIC Educational Resources Information Center

    Dakich, Eva; Watt, Tony; Hooley, Neil

    2016-01-01

    Researching the education of Aboriginal and Torres Strait Islander children in Australian schools is an exceedingly difficult and uncompromising task. Working respectfully with local Aboriginal and Torres Strait Islander communities must remain top priority with any research project regarding Aboriginal and Torres Strait Islander viewpoints of…

  4. Adha Gara Tidi: Cultural Sensitivity in Western Torres Strait. Work Papers of SIL-AAIB, Series B Volume 14.

    ERIC Educational Resources Information Center

    Kennedy, Rod; Kennedy, Judy

    This series of articles, focusing on the Western Torres Strait Islander people, presents the following: "A Brief Introduction to Torres Strait Culture" (Rod Kennedy); "Some Guidelines for Relating to Torres Strait Islanders" (Rod Kennedy); "One Mouth Two Hands" (Rod Kennedy); "My Trading Friend in the Village of…

  5. High mountain soils and periglacial features at the Torres del Paine, National Park Torres del Paine, Chile.

    NASA Astrophysics Data System (ADS)

    Senra, Eduardo; Schaefer, Carlos; Simas, Felipe; Gjorup, Davi

    2015-04-01

    The Torres del Paine National Park (TPNP) is located on the southern limit of the Andean Southern Ice Field, part of the Magallanes and Antartica Chilena region, in the province of Ultima Esperanza. The TPNP has a very heterogeneous climate due to orographic influence and wet air masses from the Pacific. The geology is basically Cretaceous metasedimentary rocks and Miocene granitic plutons and batholiths. We studied the main soils and geoenvironments of Mt Ferrier mountain and its surroundings, based on soils , landforms and vegetation aspects. The geoenvironmental stratification was based on the combined variation and integration of pedo-litho-geomorphological features with the vegetation. WE used detailed geological maps, a DEM and slope maps and WorlView II satellite images. Fifteen soils profiles were sampled and classified according to Soil Taxonomy (2010) at all genovironments, ranging from 50 m a.s.l to the at high plateau just below the permanent snowline, under periglacial conditions (~1004m asl). Three soil temperature and moisture monitoring sites were set, allowing for 24 consecutive months (2011 to 2013). Seven geoenvironments were identified with distinct soil and landform characteristics, all with a similar geological substrate. The landform and vegetation have a strong connection with the landscape dynamic, controlling erosional and depositional processes, resulting from glacier advances and retreats in the Late Quaternary. Wind blown materials is widespread, in the form of loess material, accumulating in the higher parts of the landscape. On the other hand, accumulation of organic matter in the water-saturated depressions is common in all altitudes. Generally the soils are acidic and dystrophic, with little exceptions. The following geoenvironments were identified: Periglacial Tundra, Loess slopes, Talus and scarpmentd, Fluvio-glacial terraces, Fluvio-lacustrine plains, Moraines and Paleodunes. The regional pedology show the occurrence of five soil

  6. Managing Aboriginal and Torres Strait Islander Data for Public Health Research

    PubMed Central

    van Gaans, D.; Ahmed, S.; D’Onise, K.; Taylor, S. M.; McDermott, R.

    2016-01-01

    Good quality data on Aboriginal and Torres Strait Islander peoples are needed to assess the effectiveness of programs and interventions, and to evaluate policies that are designed to improve the status of, and service delivery to, Aboriginal and Torres Strait Islander peoples. Due to the lack of longitudinal data it is difficult to gain knowledge on the specific causes or consequences of changes in indigenous outcomes. Variables such as name, date of birth and address for Aboriginal and Torres Strait Islanders may be subject to more variation and be less consistently reported than other Australians. Improving the collection and management of key identifying variables for Aboriginal and Torres Strait Islanders are key to providing more quality information on this population group. PMID:28210423

  7. Essential service standards for equitable national cardiovascular care for Aboriginal and Torres Strait Islander people.

    PubMed

    Brown, Alex; O'Shea, Rebekah L; Mott, Kathy; McBride, Katharine F; Lawson, Tony; Jennings, Garry L R

    2015-02-01

    Cardiovascular diseases (CVD) constitute the largest cause of death for Aboriginal and Torres Strait Islander people and remain the primary contributor to life expectancy differentials between Aboriginal and Torres Strait Islander and non-Indigenous Australians. As such, CVD remains the most critical target for reducing the life expectancy gap. The Essential Service Standards for Equitable National Cardiovascular Care for Aboriginal and Torres Strait Islander people (ESSENCE) outline elements of care that are necessary to reduce disparity in access and outcomes for five critical cardiovascular conditions. The ESSENCE approach builds a foundation on which the gap in life expectancy between Aboriginal and Torres Strait Islander and non-Indigenous Australians can be reduced. The standards purposefully focus on the prevention and management of CVD extending across the continuum of risk and disease. Each of the agreed essential service standards are presented alongside the most critical targets for policy development and health system reform aimed at mitigating population disparity in CVD and related conditions.

  8. Making every Australian count: challenges for the National Disability Insurance Scheme (NDIS) and the equal inclusion of homeless Aboriginal and Torres Strait Islander Peoples with neurocognitive disability.

    PubMed

    Townsend, Clare; White, Paul; Cullen, Jennifer; Wright, Courtney J; Zeeman, Heidi

    2017-03-30

    This article highlights the dearth of accurate evidence available to inform the National Disability Insurance Scheme (NDIS) regarding the extent and nature of neurocognitive disability amongst homeless Aboriginal and Torres Strait Islander people. Without accurate prevalence rates of neurocognitive disability, homeless Aboriginal and Torres Strait Islander people are in danger of not being counted by the NDIS and not receiving supports to which they are entitled. Addressing this knowledge gap is challenged by a range of factors, including: (1) the long-term effect of profound intergenerational disenfranchisement of Aboriginal and Torres Strait Islander people; (2) Aboriginal and Torres Strait Islander cultural perspectives around disability; (3) the generally unrecognised and poorly understood nature of neurocognitive disability; (4) the use of research methods that are not culturally safe; (5) research logistics; and (6) the absence of culturally appropriate assessment tools to identify prevalence. It is argued that an accurate evidence base that is informed by culturally safe research methods and assessment tools is needed to accurately guide the Commonwealth government and the National Disability Insurance Agency about the expected level of need for the NDIS. Research within this framework will contribute to the realisation of a truly inclusive NDIS.

  9. Measured and predicted temperature profiles along MEMS bridges at pressures from 0.05 to 625 torr.

    SciTech Connect

    Gallis, Michail A.; Torczynski, John Robert; Piekos, Edward Stanley; Serrano, Justin Raymond; Gorby, Allen D.; Phinney, Leslie Mary

    2010-10-01

    We will present experimental and computational investigations of the thermal performance of microelectromechanical systems (MEMS) as a function of the surrounding gas pressure. Lowering the pressure in MEMS packages reduces gas damping, providing increased sensitivity for certain MEMS sensors; however, such packaging also dramatically affects their thermal performance since energy transfer to the environment is substantially reduced. High-spatial-resolution Raman thermometry was used to measure the temperature profiles on electrically heated, polycrystalline silicon bridges that are nominally 10 microns wide, 2.25 microns thick, 12 microns above the substrate, and either 200 or 400 microns long in nitrogen atmospheres with pressures ranging from 0.05 to 625 Torr. Finite element modeling of the thermal behavior of the MEMS bridges is performed and compared to the experimental results. Noncontinuum gas effects are incorporated into the continuum finite element model by imposing temperature discontinuities at gas-solid interfaces that are determined from noncontinuum simulations. The experimental and simulation results indicate that at pressures below 0.5 Torr the gas-phase heat transfer is negligible compared to heat conduction through the thermal actuator legs. As the pressure increases above 0.5 Torr, the gas-phase heat transfer becomes more significant. At ambient pressures, gas-phase heat transfer drastically impacts the thermal performance. The measured and simulated temperature profiles are in qualitative agreement in the present study. Quantitative agreement between experimental and simulated temperature profiles requires accurate knowledge of temperature-dependent thermophysical properties, the device geometry, and the thermal accommodation coefficient.

  10. Risk factors for cancer in the Australian Aboriginal and Torres Strait Islander population: a systematic review.

    PubMed

    Castles, Simon; Wainer, Zoe; Jayasekara, Harindra

    2016-01-01

    Cancer incidence in the Australian Aboriginal and Torres Strait Islander population is higher and survival lower compared with non-Indigenous Australians. A proportion of these cancers are potentially preventable if factors associated with carcinogenesis are known and successfully avoided. We conducted a systematic review of the published literature to examine risk factors for cancer in the Australian Aboriginal and Torres Strait Islander population. Electronic databases Medline, Web of Science and the Australian Aboriginal and Torres Strait Islander Health Bibliographic Index were searched through August 2014 using broad search terms. Studies reporting a measure of association between a risk factor and any cancer site in the Australian Aboriginal and Torres Strait Islander population were eligible for inclusion. Ten studies (1991-2014) were identified, mostly with small sample sizes, showing marked heterogeneity in terms of methods used to assess exposure and capture outcomes, and often using descriptive comparative analyses. Relatively young (as opposed to elderly) and geographically remote Aboriginal and Torres Strait Islanders were found to be at increased risk for selected cancers while most modifiable lifestyle and behavioural risk factors were rarely assessed. Further studies examining associations between potential risk factors and cancer will help define public health policy for cancer prevention in the Australian Aboriginal and Torres Strait Islander population.

  11. Childhood lead poisoning from the smelter in Torreón, México.

    PubMed

    Soto-Jiménez, Martin F; Flegal, Arthur R

    2011-05-01

    Lead concentrations and isotopic compositions in blood samples of 34 children (ages 2-17 years) living within a 113 km(2) area of a silver-zinc-lead smelter plant in Torreón, México were compared to those of associated environmental samples (soil, aerosols, and outdoor and indoor dust) to identify the principal source(s) of environmental and human lead contamination in the area. Lead concentrations of soil and outdoor dust ranged 130-12,050 and 150-14,365 μg g(-1), respectively. Concentrations were greatest near the smelter, with the highest levels corresponding with the prevailing wind direction, and orders of magnitude above background concentrations of 7.3-33.3 μg g(-1). Atmospheric lead depositions in the city varied between 130 and 1350 μg m(-2) d(-1), again with highest rates <1 km from the smelter. Blood lead (PbB) concentrations (11.0±5.3 μg dl(-1)) levels in the children ranged 5.0-25.8 μg dl(-1), which is 3-14 times higher than the current average (1.9 μg dl(-1)) of children (ages 1-5 years) in the US. Lead isotopic ratios ((206)Pb/(207)Pb, (208)Pb/(207)Pb) of the urban dust and soil (1.200±0.009, 2.467±0.003), aerosols (1.200±0.002, 2.466±0.002), and PbB (1.199±0.001, 2.468±0.002) were indistinguishable from each other, as well as those of the lead ores processed at the smelter (1.199±0.007, 2.473±0.007). Consequently, an elevated PbB concentrations of the children in Torreón, as well as in their environment, are still dominated by industrial emissions from the smelter located within the city, in spite of new controls on atmospheric releases from the facility.

  12. Temporal variability in the life history and reproductive biology of female dugongs in Torres Strait: The likely role of sea grass dieback

    NASA Astrophysics Data System (ADS)

    Marsh, Helene; Kwan, Donna

    2008-09-01

    The extensive sea grass meadows in Torres Strait enable it to be a globally important habitat for the dugong, Dugong dugon, a marine mammal of cultural and dietary significance to Torres Strait Islanders and the basis for the substantial island-based fishery in the Torres Strait Protected Zone. Torres Strait sea grass communities are subjected to episodic diebacks which are now believed to be largely natural events. Information on dugong life history was obtained from specimens obtained from female dugongs as they were butchered for food by Indigenous hunters at two major dugong hunting communities in Torres Strait: Daru (9.04°S, 143.21°E) in 1978-1982 (a time of sea grass dieback and recovery) and Mabuiag Island (9.95°S, 142.15°E) in 1997-1999 (when sea grasses were abundant). Dugongs sampled in 1997-1999 had their first calf at younger ages (minimum of 6 cf. 10 years), and more frequently (interbirth interval based on all possible pregnancies 2.6±0.4 (S.E.) yr cf. 5.8±1.0 yr) than the dugongs sampled in 1978-1982. Pregnancy rates increased monotonically during 1978-1982, coincident with sea grass recovery. The age distribution of the female dugongs collected in 1997-1999 also suggested a low birth rate between 1973 and 1983 and/or or a high level of mortality for animals born during this period. These results add to the evidence from other regions that the life history and reproductive rate of female dugongs are adversely affected by sea grass loss, the effect of which cannot be separated from a possible density-dependent response to changes in dugong population size. Many green turtles in Torres Strait were also in poor body condition coincident with the 1970s sea grass dieback. The impacts of future sea grass diebacks need to be anticipated when management options for the traditional Torres Strait fisheries for dugongs and green turtles are evaluated.

  13. The Last Glacial Maximum and Termination in the Torres del Paine Region, Southern South America

    NASA Astrophysics Data System (ADS)

    Garcia, J.; Hall, B. L.; Kaplan, M. R.; Vega, R. M.; Binnie, S.; Gómez, G.; Santana, F.

    2012-12-01

    Deciphering the timing, structure and termination of the local last glacial maximum (LGM) throughout Patagonia (42-55 S) remains one of the key unsolved paleoclimate questions in Quaternary sciences. During the last glaciation, the Patagonian ice sheet formed one ice body along the Patagonian Andes (42-55 S) in southern South America, but previous work has revealed different spatiotemporal ice dynamics along the eastern and western ice margins. The Patagonian Andes is the only landmass that exists at this latitude confronting the southern westerly wind belt, which seems to have played a key role in past glacial and climate changes. Therefore, reconstructing southern Andes glacier history constitutes a key element for understanding the causes of glaciations in the Southern Hemisphere. Major progress has been made to document the local Late-Pleistocene glacier history, particularly in response to recent application of exposure-cosmogenic dating technique in the region, although only sparse well-dated paleoclimate records exist in this vast area. LGM moraine-based records in south Patagonia (~48-55 S) have been developed for the Strait of Magellan area, where full glacial conditions seems to have occurred between ~28.0 - 17.5 ka. Despite that these data seem to confirm previous glacial chronologies developed in north Patagonia and the Chilean Lake District (40-42 S), recent works in Torres del Paine and Última Esperanza basins (50-51 S), suggest that glacial maximum conditions may have occurred earlier (i.e., during Marine Isotope Stage 3) and that ice extent could have been twice the size of previously thought. Here, we discuss paleoclimatological implications from our 10Be and 26Al-dating program of moraines in the Torres del Paine region in southern Patagonia. We focused our efforts in the previously undated Río de las Viscachas (RV) I and II moraines, which occur distal to the late-glacial TDP II, III and IV moraines that enclose present lake bodies at the

  14. Photosynthetic responses of subtidal seagrasses to a daily light cycle in Torres Strait: A comparative study

    NASA Astrophysics Data System (ADS)

    Campbell, Stuart J.; Kerville, Simon P.; Coles, Robert G.; Short, Fred

    2008-09-01

    In this study, we examined the photosynthetic responses of five common seagrass species from a typical mixed meadow in Torres Strait at a depth of 5-7 m using pulse amplitude modulated (PAM) fluorometry. The photosynthetic response of each species was measured every 2 h throughout a single daily light cycle from dawn (6 am) to dusk (6 pm). PAM fluorometry was used to generate rapid light curves from which measures of electron transport rate (ETR max), photosynthetic efficiency ( α), saturating irradiance ( E k) and light-adapted quantum yield (Δ F/ F' m) were derived for each species. The amount of light absorbed by leaves (absorption factor) was also determined for each species. Similar diurnal patterns were recorded among species with 3-4 fold increases in maximal electron rate from dawn to midday and a maintenance of ETR max in the afternoon that would allow an optimal use of low light by all species. Differences in photosynthetic responses to changes in the daily light regime were also evident with Syringodium isoetifolium showing the highest photosynthetic rates and saturating irradiances suggesting a competitive advantage over other species under conditions of high light. In contrast Halophila ovalis, Halophila decipiens and Halophila spinulosa were characterised by comparatively low photosynthetic rates and minimum light requirements (i.e. low E k) typical of shade adaptation. The structural makeup of each species may explain the observed differences with large, structurally complex species such as Syringodium isoetifolium and Cymodocea serrulata showing high photosynthetic effciciencies ( α) and therefore high-light-adapted traits (e.g. high ETR max and E k) compared with the smaller Halophila species positioned lower in the canopy. For the smaller Halophila species these shade-adapted traits are features that optimise their survival during low-light conditions. Knowledge of these characteristics and responses improves our understanding of the underlying

  15. Instantaneous stroke volume by PDE during and after constant LBNP (-50 torr)

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Six male subjects were exposed to -50 torr lower body negative pressure (LBNP) for 10 min while stroke volume was recorded beat by beat at regular intervals before, during and after release of LBNP. Stroke volume was calculated from the systolic velocity integral in the ascending aorta by pulsed Doppler echocardiography (PDE) and the cross sectional area of the vessel by M mode echocardiography. Changes in leg volume were recorded continuously and blood pressure was taken every minute. Stroke volume dropped by 51% of the control in the first 33 sec of LBNP and continued to decline slowly to -62% toward the end. Heart rate increased by 15% in the first 10 sec and was 22% above control at the end of exposure. The resulting cardiac output closely followed the course of stroke volume (-47% at 33 sec, -53% at 8 min) showing that the modest increase in heart rate did little to offset the drop in stroke volume. Leg volume increased markedly within the first 10 sec with a more gradual rise reaching +3.5% at the end. Upon sudden release of LBNP, leg volume dropped significantly during the first 3 sec simultaneously with an increase in stroke volume followed by a substantial decline in heart rate below the baseline.

  16. Effective communication tools to engage Torres Strait Islanders in scientific research

    NASA Astrophysics Data System (ADS)

    Jones, A.; Barnett, B.; Williams, A. J.; Grayson, J.; Busilacchi, S.; Duckworth, A.; Evans-Illidge, E.; Begg, G. A.; Murchie, C. D.

    2008-09-01

    Often, research activities in Torres Strait have not delivered full benefit to Torres Strait Islanders due to a lack of consultation, ineffectual communication of research information and lack of empathy for the needs of Islander communities. As for other stakeholder groups, integration of Islanders into the research process through practical involvement in research may overcome these problems. Three case studies from research projects conducted in Torres Strait are discussed to highlight a variety of communication and engagement activities carried out by non-Indigenous researchers. How these communication and extension activities facilitate collaboration between Torres Strait Islander and non-Indigenous researchers provides insight in the importance of these activities to the relative success of research projects. The benefits for Islanders in collaborating with researchers may be: improved understanding of the research and how it contributes to natural resource management; a sense of control in future management decisions; a greater likelihood of successful self-regulatory management systems; enhanced skills; and increased employment opportunities. The potential benefits for researchers are enhanced support for research projects resulting in increased access to data and logistic support that may ultimately impact the successful completion of projects. Such an approach will require researchers to take time to develop relationships with Torres Strait Islanders, effectively involve Islanders in research on an equitable basis and be flexible. This will ultimately require funding organisations to recognise the importance of such activities in research proposals and provide support through sufficient funding to enable these activities to be carried out.

  17. Measurements of Aerodynamic Heat Transfer and Boundary-Layer Transition on a 15 deg. Cone in Free Flight at Supersonic Mach Numbers up to 5.2

    NASA Technical Reports Server (NTRS)

    Rumsey, Charles B.; Lee, Dorothy B.

    1961-01-01

    Measurements of aerodynamic heat transfer have been made at several stations on the 15 deg total-angle conical nose of a rocket-propelled model in free flight at Mach numbers up to 5.2. Data are presented for a range of local Mach number just outside the boundary layer from 1.40 to 4.65 and a range of local Reynolds number from 3.8 x 10(exp 6) to 46.5 x 10(exp 6), based on length from the nose tip to a measurement station. Laminar, transitional, and turbulent heat-transfer coefficients were measured. The laminar data were in agreement with laminar theory for cones, and the turbulent data agreed well with turbulent theory for cones using Reynolds number based on length from the nose tip. At a nearly constant ratio of wall to local static temperature of 1.2 the Reynolds number of transition increased from 14 x 10(exp 6) to 30 x 10(exp 6) as Mach number increased from 1.4 to 2.9 and then decreased to 17 x 10(exp 6) as Mach number increased to 3.7. At Mach numbers near 3.5, transition Reynolds numbers appeared to be independent of skin temperature at skin temperatures very cold with respect to adiabatic wall temperature. The transition Reynolds number was 17.7 x 10(exp 6) at a condition of Mach number and ratio of wall to local static temperature near that for which three-dimensional disturbance theory has been evaluated and has predicted laminar boundary-layer stability to very high Reynolds numbers (approximately 10(exp 12)).

  18. Acceptability of Mental Health Apps for Aboriginal and Torres Strait Islander Australians: A Qualitative Study

    PubMed Central

    Mills, Patj Patj Janama Robert; Dingwall, Kylie Maree; Lowell, Anne; Singer, Judy; Rotumah, Darlene; Bennett-Levy, James; Nagel, Tricia

    2016-01-01

    Background Aboriginal and Torres Strait Islander Australians experience high rates of mental illness and psychological distress compared to their non-Indigenous counterparts. E-mental health tools offer an opportunity for accessible, effective, and acceptable treatment. The AIMhi Stay Strong app and the ibobbly suicide prevention app are treatment tools designed to combat the disproportionately high levels of mental illness and stress experienced within the Aboriginal and Torres Strait Islander community. Objective This study aimed to explore Aboriginal and Torres Strait Islander community members’ experiences of using two culturally responsive e-mental health apps and identify factors that influence the acceptability of these approaches. Methods Using qualitative methods aligned with a phenomenological approach, we explored the acceptability of two culturally responsive e-mental health apps through a series of three 3-hour focus groups with nine Aboriginal and Torres Strait Islander community members. Thematic analysis was conducted and coresearcher and member checking were used to verify findings. Results Findings suggest strong support for the concept of e-mental health apps and optimism for their potential. Factors that influenced acceptability related to three key themes: personal factors (eg, motivation, severity and awareness of illness, technological competence, and literacy and language differences), environmental factors (eg, community awareness, stigma, and availability of support), and app characteristics (eg, ease of use, content, graphics, access, and security and information sharing). Specific adaptations, such as local production, culturally relevant content and graphics, a purposeful journey, clear navigation, meaningful language, options to assist people with language differences, offline use, and password protection may aid uptake. Conclusions When designed to meet the needs of Aboriginal and Torres Strait Islander Australians, e-mental health

  19. Introducing Torres Strait Island Dance to the Australian High School Physical Education Curriculum

    ERIC Educational Resources Information Center

    Williams, John

    2014-01-01

    This study was carried out within the context of a requirement for every Australian Capital Territory Education and Training Directorate (ACT ETD) high school to include Indigenous perspectives across all areas of the curriculum. For the first time ever in the case study school reported in this article, two Torres Strait Island dances were taught…

  20. Guide to Success for Organisations in Achieving Employment Outcomes for Aboriginal and Torres Strait Islander People

    ERIC Educational Resources Information Center

    Giddy, Kristine; Lopez, Jessica; Redman, Anne

    2009-01-01

    Helping Aboriginal and Torres Strait Islander job-seekers find and keep a job has been the focus of recent reforms announced by the Australian Government. This guide describes seven essential characteristics of employment service organisations that lead to successful employment outcomes for their Indigenous clients. Based on a selection of…

  1. Contextualising the Teaching and Learning of Measurement within Torres Strait Islander Schools

    ERIC Educational Resources Information Center

    Ewing, Bronwyn; Cooper, Thomas J.; Baturo, Annette R.; Matthews, Chris; Sun, Huayu

    2010-01-01

    A one-year mathematics project that focused on measurement was conducted with six Torres Strait Islander schools and communities. Its key focus was to contextualise the teaching and learning of measurement within the students' culture, communities and home languages. Six teachers and two teacher aides participated in the project. This paper…

  2. Developing Future Health Professionals' Capacities for Working with Aboriginal and Torres Strait Islander Peoples

    ERIC Educational Resources Information Center

    Hendrick, Antonia; Britton, Katherine Frances; Hoffman, Julie; Kickett, Marion

    2014-01-01

    This article details reflections of an interdisciplinary team of educators working with groups of health sciences students in preparing them for working with Aboriginal and Torres Strait Islander peoples. The first-year common core unit discussed here is one attempt to equip future health practitioners with skills and knowledges to work adequately…

  3. Mathematics Funds of Knowledge: "Sotmaute" and "Sermaute" Fish in a Torres Strait Islander Community

    ERIC Educational Resources Information Center

    Ewing, Bronwyn

    2012-01-01

    The purpose of this article is to describe a project with one Torres Strait Islander Community. It provides some insights into parents' funds of knowledge that are mathematical in nature, such as sorting shells and giving fish. The idea of funds of knowledge is based on the premise that people are competent and have knowledge that has been…

  4. Indigenous Language Learning and Maintenance among Young Australian Aboriginal and Torres Strait Islander Children

    ERIC Educational Resources Information Center

    Verdon, Sarah; McLeod, Sharynne

    2015-01-01

    Internationally, cultural renewal and language revitalisation are occurring among Indigenous people whose lands were colonised by foreign nations. In Australia, the Aboriginal and Torres Strait Islander people are striving for the re-voicing of their mother tongue and the re-practicing of their mother culture to achieve cultural renewal in the…

  5. MSH-6: extending the reliability of immunohistochemistry as a screening tool in Muir-Torre syndrome.

    PubMed

    Chhibber, Vishes; Dresser, Karen; Mahalingam, Meera

    2008-02-01

    The subtype of Muir-Torre syndrome, allelic to hereditary nonpolyposis colorectal cancer is typically associated with germline mutations in the mismatch repair proteins MSH-2 and/or MLH-1. More recently, mutation in an additional mismatch repair protein MSH-6 has been documented in a patient with Muir-Torre syndrome. Given this, the aim of the present study was to ascertain the frequency of the same in unselected sebaceous gland neoplasms. Overall, we found that 59% of sebaceous neoplasms exhibited a mutation in at least one mismatch repair protein gene -- a prevalence rate similar to that reported previously by others. Of interest, we found MSH-6 to be the mismatch repair protein most commonly lost 17/41 (41%), followed by MSH-2 14/41 (34%) and MLH-18/41 (20%) and the positive predictive value of each were as follows: MLH-1 88%, MSH-6 67% and MSH-2 55%. The frequency of a MSH-6 germline mutation in our cohort indicates that it is not a rare finding. Evidence indicating microsatellite stability in three of 17 patients with a clinical history indicative of Muir-Torre syndrome and a mutation in only MSH-6 suggests that the phenotype of a germline MSH-6 mutation differs from that of MLH-1 and MSH-2 mutations and further supports the use of immunohistochemistry as a screening tool in patients with Muir-Torre syndrome with an extended panel that includes MSH-6.

  6. The Education of Australian Aboriginal and Torres Strait Islander Students: Repair or Radical Change

    ERIC Educational Resources Information Center

    Reynolds, Richard J.

    2005-01-01

    Australia's indigenous population is made up of Aboriginal and Torres Strait Islander peoples, who each have distinctly different cultures. The former can be found in cities and towns and cross the vast reaches of rural and remote Australia; the latter inhabit the coastal islands off the northeast coast and adjacent mainland areas. According to…

  7. Supporting Australian Torres Strait Islander and Aboriginal Nursing Students Using Mentoring Circles: An Action Research Study

    ERIC Educational Resources Information Center

    Mills, Jane; Felton-Busch, Catrina; Park, Tanya; Maza, Karen; Mills, Frances; Ghee, McCauley; Hitchins, Marnie; Chamberlain-Salaun, Jennifer; Neuendorf, Nalisa

    2014-01-01

    Attempts to recruit Aboriginal and Torres Strait Islander students into nursing degrees have made minimal impact on the number of registered nurses working in Australia's healthcare sector. Yet increasing the number of Indigenous nurses remains one of the most important objectives in strategies to close the health gap between Indigenous and…

  8. New species of Nuuanu (Amphipoda: Nuuanuidae) from Norfolk Island, Torres Strait and the Cocos (Keeling) Islands.

    PubMed

    Hughes, L E; Bopiah, A

    2013-01-01

    Three new species of Nuuanu, N. quintalana sp. nov., N. stuckeyorun sp. nov. and N. titaseyi sp. nov. are described from Norfolk Island, Tasman Sea; Cocos (Keeling) Islands, Indian Ocean and the Torres Strait, Australia, respectively. There are currently 17 described species of Nuuanu with the genus distributed world-wide.

  9. A Profile of the Aboriginal and Torres Strait Islander Higher Education Student Population

    ERIC Educational Resources Information Center

    Wilks, Judith; Wilson, Katie

    2015-01-01

    This paper brings together recent statistics relating to the participation of Aboriginal and Torres Strait Islander students in higher education. A number of key statistical realities relating to their enrolment into, retention during, and completion of, their university courses are depicted. Foremost among these realities is that despite…

  10. Evaluation of the pilot phase of an Aboriginal and Torres Strait Islander Male Health Module.

    PubMed

    Tsey, Komla; Chigeza, Philemon; Holden, Carol A; Bulman, Jack; Gruis, Hilton; Wenitong, Mark

    2014-01-01

    This article evaluates the pilot phase of an Aboriginal and Torres Strait Islander Male Health Module. Although men experience higher levels of illness and die younger than women, educational programs to support health workers utilise a gender-based approach to increase participation of Aboriginal and Torres Strait Islander males in health care are rare and lack appropriate content. Recognising this gap in service provision, and under the guidance of a Reference Group comprising community leaders in Aboriginal and Torres Strait male health, a comprehensive and culturally appropriate Male Health Module has been developed to enhance the capacity of health workers to improve access to services for Aboriginal and Torres Strait Islander males. Methods used were: in-depth interviews with Module developers, pilot workshops for trainers and health workers, questionnaires and focus group discussions with workshop participants, and participant observations. As well as enhancing capacity to facilitate access to health services for men, the Module was deemed relevant because of its potential to promote health worker empowerment and wellbeing. Findings revealed that improving access to services for men required male and female health workers working in partnership. Despite overall enthusiasm for the Module, the findings also revealed deep fear that it would end up 'collecting dust on shelves'. Strategies to improve the Module quality and accessibility are highlighted.

  11. Structural compartmentalisation of a geothermal system, the Torre Alfina field (central Italy)

    NASA Astrophysics Data System (ADS)

    Vignaroli, Gianluca; Pinton, Annamaria; De Benedetti, Arnaldo A.; Giordano, Guido; Rossetti, Federico; Soligo, Michele; Berardi, Gabriele

    2013-11-01

    Recent surging of renewed industrial interest in the exploration of low and medium enthalpy geothermal fields makes the accurate assessment of the geothermal potential essential to minimise uncertainties during both exploration and exploitation. The Torre Alfina field is a case of abandoned, but promising, geothermal field of central Italy where the roles of the internal structural setting and of the recharge areas on the hydrothermal circulation are largely unconstrained. In this paper, field structural data integrated with geomorphic lineament analysis document the occurrence of post-orogenic deformation structures controlling the compartmentalisation of the Torre Alfina geothermal field. Strike-slip and subordinate normal fault systems (with associated network fractures) cut and dislocate the internal architecture of the reservoir and prevent its hydraulic connection with Mount Cetona, considered to be the recharge area and where hydrothermal manifestation, including travertine deposition, occurs. 230Th/234U radiometric dating of superposed travertine units gives 200, 120 and 90 ka respectively, inferred to correspond to the age of the fossil hydrothermal circulation during tectonic activity. The results have been used for illustrating a new geological conceptual model for the Torre Alfina area where the geothermal system is composed of different compartments. Tectonic structures define the main boundaries between compartments, helping the understanding of why productive and non-productive wells were found in apparently similar structural settings within the Torre Alfina field.

  12. The origin of oriented lakes in the Andean foreland, Parque Nacional Torres del Paine (Chilean Patagonia)

    NASA Astrophysics Data System (ADS)

    Gonzales, Joseph; Aydin, Atilla

    2008-05-01

    The Parque Nacional Torres Del Paine and surrounding area in the Magallanes foreland basin in Chilean Patagonia is the site for numerous lakes fed by glaciers and rivers in the Andean highlands to the west. The lakes are elongate and have conspicuously systematic orientations. We hypothesize that the origin of the oriented lakes lies in the fault system, composed of a right-lateral strike-slip fault set oriented 58° from north, a left-lateral strike-slip set oriented 87°, and a thrust fault set oriented 167°, that exists within the underlying rocks. To test this hypothesis quantitatively, we determined the shape and orientation of the lakes by fitting each lake with an ellipse of appropriate aspect ratio, and later with multiple ellipses consistent with the composite geometry of some lakes. We then examined the faults in the area in terms of their kinematics, orientation and distribution. The distribution of lake orientations showed three distinct groups which appear to correspond to the three main fault groups. For lakes fitted with multiple ellipses, the difference in means between the right-lateral, left-lateral, and thrust faults and their corresponding groups of lakes are 3.05°, 1.57°, and 5.17°. Using a Kolmogorov-Smirnov (K-S) statistical test to compare the orientations of faults with respect to the lakes suggests that there is not a strongly significant difference between the fault orientations and the corresponding lake groups. These results indicate that the faults have a profound control on the orientation, shape, and distribution of the lakes. We attribute this to faults and their damage zones being weaker and therefore prone to a faster rate of erosion, and to stress perturbations associated with discontinuous faults resulting in localized high density fracturing and surface subsidence. These results have implications for lake and drainage system morphologies in other foreland basins along the Andes and other similar settings.

  13. Introduced marine species: Management arrangements of consideration for the Torres Strait

    NASA Astrophysics Data System (ADS)

    Neil, Kerry M.; Hilliard, Robert; Russell, Barry; Clark, Paul

    2008-09-01

    Introduced marine species (IMS) can have significant impacts on economic, ecological, social and cultural aspects of coastal marine environments. There is, therefore, a need to minimise these impacts through the implementation of comprehensive and consistent management strategies and monitoring processes that work towards preventing introductions, detecting introductions if they were to occur and managing incursions should they be detected. There is also the need to ensure that approaches taken are comparable to provide consistency of IMS management effort, particularly across areas that are multi-jurisdictional (e.g. spanning State or Territory borders). A number of studies have examined IMS, their vectors and management arrangements for the Torres Strait region, a multi-jurisdictional area between Queensland, Australia and Papua New Guinea. This paper presents information from a baseline survey conducted in the Torres Strait for marine pests in conjunction with a synthesis of information from other studies on IMS risks, their vectors and management strategies of relevance to the Torres Strait region. A number of strengths, but also gaps, between the various jurisdictions have been identified and discussed. Processes such as the establishment of Biosecurity Queensland as a specialist group and the development of the National System for the Prevention and Management of Marine Pest Incursions are occurring. However, the Torres Strait region is at current risk of marine pest inoculation, particularly for species such as Perna viridis, and management strategies to minimise this risk are lacking. The information presented here will assist management groups in their ability to work towards mitigating the risk of an IMS being translocated to and negatively impacting the unique and diverse ecology of the marine systems, and the industries, people and customs that rely on the coastal marine environment for food, recreation and commerce in the Torres Strait.

  14. Consultation with Aboriginal and Torres Strait Islander People in Early Childhood Education: The Impact of Colonial Discourses

    ERIC Educational Resources Information Center

    Miller, Melinda G.

    2015-01-01

    In Australian early years education, consultation and partnerships with Aboriginal and Torres Strait Islander people are central to embedding Indigenous perspectives. Building sustained and reciprocal partnerships with Aboriginal and Torres Strait Islander people supports access to local knowledges and perspectives to inform curriculum planning,…

  15. Characteristics and outcomes of critically ill Aboriginal and/or Torres Strait Islander patients in North Queensland.

    PubMed

    Trout, M I; Henson, G; Senthuran, S

    2015-03-01

    A retrospective cohort analysis of an admission database for the intensive care unit at The Townsville Hospital was undertaken to describe the characteristics and short-term outcomes of critically ill Aboriginal and Torres Strait Islander patients. The Townsville Hospital is the tertiary referral centre for Northern Queensland and services a region in which Aboriginal and Torres Strait Islander people constitute 9.6% of the population. Aboriginal and Torres Strait Islander patients were significantly younger and had higher rates of invasive mechanical ventilation, emergency admissions and transfers from another hospital. Despite these factors, intensive care mortality did not differ between groups (9.4% versus 7.7%, P=0.1). Higher Acute Physiology and Chronic Health Evaluation III-j scores were noted in the Aboriginal and Torres Strait Islander population requiring emergency admission (65 versus 60, P=0.022) but were lower for elective admission (38 versus 42, P <0.001). Despite higher predicted hospital mortality for Aboriginal and Torres Strait Islander patients requiring emergency admission, no significant difference was observed (20.1% versus 19.1%, P=0.656). In a severity adjusted model, Aboriginal and/or Torres Strait Islander status did not statistically significantly alter the risk of death (odds ratio 0.88, 95% confidence interval 0.65, 1.2, P=0.398). Though Aboriginal and Torres Strait Islander patients requiring intensive care differed in admission characteristics, mortality was comparable to other critically ill patients.

  16. Population biology of coral trout species in eastern Torres Strait: Implications for fishery management

    NASA Astrophysics Data System (ADS)

    Williams, Ashley J.; Currey, Leanne M.; Begg, Gavin A.; Murchie, Cameron D.; Ballagh, Aaron C.

    2008-09-01

    Coral trout ( Plectropomus spp.) are the main target species for commercial fishers in the eastern Torres Strait Reef Line Fishery (ETS RLF). The four species of coral trout known to occur in Torres Strait: Plectropomus leopardus, Plectropomus maculatus, Plectropomus areolatus and Plectropomus laevis are currently managed as a single species in Torres Strait, as there is no species-specific biological information available for the region which could be used to assess whether species differ in their response to fishing pressure. The aim of our study was to determine whether it is appropriate (biologically) to manage coral trout in the ETS RLF as a single species group or whether different management arrangements are required for some species. We used catch data and biological data from samples collected by commercial fishers to examine the distribution within Torres Strait and estimate a range of biological parameters for P. leopardus, P. maculatus and P. areolatus. Insufficient P. laevis samples were collected to reliably examine this species. Results indicated that the population biology, particularly the reproductive biology, of P. areolatus was substantially different to both P. leopardus and P. maculatus. Although it is difficult to predict the response to fishing, P. areolatus may be more vulnerable to fishing than P. leopardus and P. maculatus, due to the larger size at sex change observed for this species and the very low proportion of males protected by the current minimum size limit. Therefore, while the common management arrangements for P. leopardus and P. maculatus appear to be adequate for these species, separate management arrangements are needed for the sustainable harvest of P. areolatus populations in the ETS. Specifically, we recommend the introduction of a maximum size limit for P. areolatus, in addition to the current minimum size limit, which may allow a proportion of males some protection from fishing.

  17. UP-TORR: online tool for accurate and Up-to-Date annotation of RNAi Reagents.

    PubMed

    Hu, Yanhui; Roesel, Charles; Flockhart, Ian; Perkins, Lizabeth; Perrimon, Norbert; Mohr, Stephanie E

    2013-09-01

    RNA interference (RNAi) is a widely adopted tool for loss-of-function studies but RNAi results only have biological relevance if the reagents are appropriately mapped to genes. Several groups have designed and generated RNAi reagent libraries for studies in cells or in vivo for Drosophila and other species. At first glance, matching RNAi reagents to genes appears to be a simple problem, as each reagent is typically designed to target a single gene. In practice, however, the reagent-gene relationship is complex. Although the sequences of oligonucleotides used to generate most types of RNAi reagents are static, the reference genome and gene annotations are regularly updated. Thus, at the time a researcher chooses an RNAi reagent or analyzes RNAi data, the most current interpretation of the RNAi reagent-gene relationship, as well as related information regarding specificity (e.g., predicted off-target effects), can be different from the original interpretation. Here, we describe a set of strategies and an accompanying online tool, UP-TORR (for Updated Targets of RNAi Reagents; www.flyrnai.org/up-torr), useful for accurate and up-to-date annotation of cell-based and in vivo RNAi reagents. Importantly, UP-TORR automatically synchronizes with gene annotations daily, retrieving the most current information available, and for Drosophila, also synchronizes with the major reagent collections. Thus, UP-TORR allows users to choose the most appropriate RNAi reagents at the onset of a study, as well as to perform the most appropriate analyses of results of RNAi-based studies.

  18. [The effects of TorR protein on initiation of DNA replication in Escherichia coli].

    PubMed

    Yuan, Yao; Jiaxin, Qiao; Jing, Li; Hui, Li; Morigen, Morigen

    2015-03-01

    The two-component systems, which could sense and respond to environmental changes, widely exist in bacteria as a signal transduction pathway. The bacterial CckA/CtrA, ArcA/ArcB and PhoP/PhoQ two-component systems are associated with initiation of DNA replication and cell division, however, the effects of the TorS/TorR system on cell cycle and DNA replication remains unknown. The TorS/TorR system in Escherichia coli can sense changes in trimethylamine oxide (TMAO) concentration around the cells. However, it is unknown if it also affects initiation of DNA replication. We detected DNA replication patterns in ΔtorS and ΔtorR mutant strains by flow cytometry. We found that the average number of replication origins (oriCs) per cell and doubling time in ΔtorS mutants were the same while the average number of oriCs in ΔtorR mutants was increased compared with that in wild-type cells. These results indicated that absence of TorR led to an earlier initiation of DNA replication than that in wild-type cells. Strangely, neither overexpression of TorR nor co-expression of TorR and TorS could restore ΔtorR mutant phenotype to the wild type. However, overexpression of SufD in both wild type and ΔtorR mutants promoted initiation of DNA replication, while mutation of SufD delayed it in ΔtorR mutants. Thus, TorR may affect initiation of DNA replication indirectly through regulating gene expression of sufD.

  19. Measurements of Aerodynamic Heat Transfer and Boundary-Layer Transition on a 10 deg Cone in Free Flight at Supersonic Mach Numbers up to 5.9

    NASA Technical Reports Server (NTRS)

    Rumsey, Charles B.; Lee, Dorothy B.

    1961-01-01

    Measurements of aerodynamic heat transfer have been made at six stations on the 40-inch-long 10 deg. total-angle conical nose of a rocket- propelled model which was flight tested at Mach numbers up to 5.9. are presented for a range of local Mach number just outside the bound- ary layer on the cone from 1.57 to 5.50, and a range of local Reynolds number from 6.6 x 10(exp 6) to 55.2 x 10(exp 6) based on length from the nose tip.

  20. Architectural patterns in a multistorey mixed carbonate siliciclastic submarine channel, Porto Torres Basin, Miocene, Sardinia, Italy

    NASA Astrophysics Data System (ADS)

    Vigorito, Mario; Murru, Marco; Simone, Lucia

    2006-05-01

    In the Sassari area, the analysis of extensive exposures of the Porto Torres sub-basin fill sequences have facilitated a detailed reconstruction of a complex multistorey mixed carbonate-siliciclastic submarine channel, the Sassari Channel. The exposed sequences, dated as Burdigalian-Serravallian, comprise channel complexes up to 4 km wide and 250-300 m thick fringed by marly sheet deposits. Channels are erosional or mixed erosional-depositional type and show multiple, stacked partly nested channel-fill sequences which relate to different filling phases. Individual channel-fills include sand- to cobble-sized deposits which are locally capped by thin-bedded, intensely bioturbated, hemipelagic marls which are related to temporary abandon of the channel, possibly in relation to sea level rise. Architectural elements recognised at outcrop include distinct mid-channel, margin-levee and overbank complexes as well as sheets and drapes of marly basinal deposits. Channel margins, which are locally characterised by very complex depositional architectures, also include up to 15- to 20-m-high lateral bars. Mid-channel complexes are commonly parallel to concave up stratified and locally exhibit minor order nested channel bodies. These erode, overlap or lie alongside each other and suggest repeated channel thalweg digressions and avulsions. Channel-fill architectures are locally complicated by the presence of megabreccias which include up to a few tens of metres high and hundreds of metres wide displaced and/or tilted blocks. Megabreccias are commonly associated with sand injections and/or minor faults and resulted from channel-margin collapses boosted by tectonics and/or by pore water overpressures generated in horizons hydrologically confined between early-cemented bed packages. Channel-fill sequences consist of carbonate- and siliciclastic-dominated deposits. Carbonate deposits are made up of cobbly to sandy rhodalgal debris and also exhibit 5- to 20-m-thick well

  1. D Model of the Torres Syncline in the PARANÁ-ETENDEKA Province, South Atlantic Margin

    NASA Astrophysics Data System (ADS)

    Jerram, D. A.; Waichel, B. L.; Lima, E. F. D.; Rossetti, L. D. M. M.; Bueno, G. V.; Viana, A. R.; Barreto, C. J.

    2015-12-01

    The Paraná-Etendeka Volcanic Province (PEVP) is Early Cretaceous in age and precedes the fragmentation of the south Gondwana. These volcanic rocks cover an area in excess of 1,200,000 km2 and can reach a maximum thickness of 1,700 m. The PEVP is composed mainly of tholeiitic basalts and subordinately by andesites and rhyolites/quartz-latites. Recently new models considering physical characteristics of the lava flow stratigraphy on both sides, Africa and South America, have been built providing a new vision of the volcanic stratigraphy and flow morphologies inside the province. This work presents a 3D model of the volcanic sequence at theTorres Syncline (Brazil). The 3D model was build using the PETREL E&P Software Platform. Geological sections based on field data and Log data from Paraná Basin (Gama-ray and soniclogs) were used to build the model. The Torres Syncline is a tectonic structure located in southern Brazil with the main orientation NW-SE. In Torres Syncline the basal portion is characterized by pahoehoe lava flows in a compound braided architecture, followed by rubbly lavas in a tabular classic architecture, and in the upper portions silicic units interbedded with basaltic lavas. The central portion of the volcanic pile is characterized by thick tabular lavas with rubbly tops (25-50 m thick). These flows have an internal structure divided in four parts: a smooth vesicular base, aphanitic massive cores with irregular joints, upper vesicular portion and a rubbly top. This unit is thicker along of the Torres Syncline and represents the main phase of the volcanism. Silicic units occur in the upper parts of the PEVP stratigraphy and include lava domes interbedded with rubbly flows and thick tabular flows. The Torres Syncline and Huab constituted one Basin features single active structure in the Early Cretaceous and during the main rifting phase. The onset of the volcanism was characterized by low effusion rate eruptions over the paleoerg, forming pahoehoe

  2. Specific Volumes of the Zr(41.2)Ti(13.8)Cu(12.5)Ni(10.0)Be(22.5) Alloy in the Liquid, Glass, and Crystalline States

    NASA Technical Reports Server (NTRS)

    Ohsaka, K.; Chung, S. K.; Rhim, W. K.; Johnson, W. L.; Peker, A.; Scruggs, D.

    1997-01-01

    The specific volumes of the Zr(41.2)Ti(3.8)Cu(2.5)Ni(10.0)Be(22.5) alloy as a function of temperature, T, are determined by employing an image digitizing technique and numerical calculation methods applied to the electrostatically levitated spherical alloy. The linear fitting of the volumes of the alloy in the liquid, V(sub l), glass, V(sub g) and crystalline V(sub c), states in the temperature ranges shown in parentheses are V(sub l)(T) = 0.1583 + 8.877 x 10(exp -6) T(cu cm/g) (700-1300 K);V(sub g)(T) = 0.1603 + 5.528 x 10(exp -6) T (400-550 K);V(sub c)(T) = 0.1583 + 6.21 x 10(exp -6)T(400-850 K). The average volume thermal expansion coefficients within the temperature ranges are determined to be 5.32, 3.39. and 3.83 x 10(exp -5) (1/K) for the liquid, glass, and crystalline states, respectively.

  3. The Torres del Paine intrusion as a model for a shallow magma chamber

    NASA Astrophysics Data System (ADS)

    Baumgartner, Lukas; Bodner, Robert; Leuthold, Julien; Muntener, Othmar; Putlitz, Benita; Vennemann, Torsten

    2014-05-01

    The shallow magmatic Torres del Paine Intrusive Complex (TPIC) belongs to a series of sub-volcanic and plutonic igneous bodies in Southern Chile and Argentina. This trench-parallel belt is located in a transitional position between the Patagonia Batholith in the West, and the alkaline Cenozoic plateau lavas in the East. While volumetrically small amounts of magmatism started around 28 my ago in the Torres del Paine area, and a second period occurred between 17-16 Ma, it peaked with the TPIC 12.59-12.43 Ma ago. The spectacular cliffs of the Torres del Paine National park provide a unique opportunity to study the evolution of a very shallow magma chamber and the interaction with its host rocks. Intrusion depth can be estimated based on contact metamorphic assemblages and granite solidus thermobarometry to 750±250 bars, corresponding to an intrusion depth of ca. 3km, ca. 500m above the base of the intrusion. Hornblende thermobarometry in mafic rocks agrees well with these estimates (Leuthold et al., 2014). The TPIC is composed of a granitic laccolith emplaced over 90ka (Michel et al., 2008) in 3 major, several 100m thick sheets, forming an overall thickness of nearly 2 km. Contacts are sharp between sheets, with the oldest sheet on the top and the youngest on the bottom (Michel et al., 2008). The granitic laccolith is under-plated by a ca. 400m thick mafic laccolith, built up over ca. 50ka (Leuthold et al. 2012), constructed from the bottom up. Granitic and mafic sheets are themselves composed of multiple metric to decametric pulses, mostly with ductile contacts between them, resulting in outcrop patterns resembling braided stream sediments. The contact of the TPIC with the Cretaceous flysch sediments document intrusion mechanism. Pre-existing sub-horizontal fold axes are rotated in the roof of the TPIC, clearly demonstrating ballooning of the roof; no ballooning was observed in the footwall of the intrusion. Extension during ballooning of the roof is indicated by

  4. Using participatory action research to prevent suicide in Aboriginal and Torres Strait Islander communities.

    PubMed

    Cox, Adele; Dudgeon, Pat; Holland, Christopher; Kelly, Kerrie; Scrine, Clair; Walker, Roz

    2014-01-01

    The National Empowerment Project is an innovative Aboriginal-led community empowerment project that has worked with eight Aboriginal and Torres Strait Islander communities across Australia over the period 2012-13. The aim of the Project was to develop, deliver and evaluate a program to: (1) promote positive social and emotional well-being to increase resilience and reduce the high reported rates of psychological distress and suicide among Aboriginal and Torres Strait Islander people; and (2) empower communities to take action to address the social determinants that contribute to psychological distress, suicide and self-harm. Using a participatory action research approach, the communities were supported to identify the risk factors challenging individuals, families and communities, as well as strategies to strengthen protective factors against these challenges. Data gathered during Stage 1 were used to develop a 12-month program to promote social and emotional well-being and build resilience within each community. A common framework, based on the social and emotional well-being concept, was used to support each community to target community-identified protective factors and strategies to strengthen individual, family and community social and emotional well-being. Strengthening the role of culture is critical to this approach and marks an important difference between Aboriginal and Torres Strait Islander and non-Indigenous mental health promotion and prevention activities, including suicide prevention. It has significant implications for policy makers and service providers and is showing positive impact through the translation of research into practice, for example through the development of a locally run empowerment program that aims to address the social determinants of health and their ongoing negative impact on individuals, families and communities. It also provides a framework in which to develop and strengthen culture, connectedness and foster self

  5. A snapshot of physical activity programs targeting Aboriginal and Torres Strait Islander people in Australia.

    PubMed

    Macniven, Rona; Elwell, Michelle; Ride, Kathy; Bauman, Adrian; Richards, Justin

    2017-01-19

    Issue addressed: Participation in physical activity programs can be an effective strategy to reduce chronic disease risk factors and improve broader social outcomes. Health and social outcomes are worse among Aboriginal and Torres Strait Islanders than non-Indigenous Australians, who represent an important group for culturally specific programs. The extent of current practice in physical activity programs is largely unknown. This study identifies such programs targeting this population group and describes their characteristics.Methods: Bibliographic and Internet searches and snowball sampling identified eligible programs operating between 2012 and 2015 in Australia (phase 1). Program coordinators were contacted to verify sourced information (phase 2). Descriptive characteristics were documented for each program.Results: A total of 110 programs were identified across urban, rural and remote locations within all states and territories. Only 11 programs were located through bibliographic sources; the remainder through Internet searches. The programs aimed to influence physical activity for health or broader social outcomes. Sixty five took place in community settings and most involved multiple sectors such as sport, health and education. Almost all were free for participants and involved Indigenous stakeholders. The majority received Government funding and had commenced within the last decade. More than 20 programs reached over 1000 people each; 14 reached 0-100 participants. Most included process or impact evaluation indicators, typically reflecting their aims.Conclusion: This snapshot provides a comprehensive description of current physical activity program provision for Aboriginal and Torres Strait Islander people across Australia. The majority of programs were only identified through the grey literature. Many programs collect evaluation data, yet this is underrepresented in academic literature.So what?: Capturing current practice can inform future efforts to

  6. Delayed Alumina Scale Spallation on Rene'n5+y: Moisture Effects and Acoustic Emission

    NASA Technical Reports Server (NTRS)

    Smialek, James L.; Morscher, Gregory N.

    2001-01-01

    The single crystal superalloy Rene'N5 (with or without Y-doping and hydrogen annealing) was cyclically oxidized at 1150 C for 1000 hours. After considerable scale growth (>= 500 hours), even the adherent alumina scales formed on Y-doped samples exhibited delayed interfacial spallation during subsequent water immersion tests, performed up to one year after oxidation. Spallation was characterized by weight loss, the amount of spalled area, and acoustic emission response. Hydrogen annealing (prior to oxidation) reduced spallation both before and after immersion, but without measurably reducing the bulk sulfur content of the Y-doped alloys. The duration and frequency of sequential, co-located acoustic emission events implied an interfacial crack growth rate at least 10(exp -3) m/s, but possibly higher than 10(exp 2) m/s. This is much greater than classic moisture-assisted slow crack growth rates in bulk alumina (10(exp -6) to 10(exp -3) m/s), which may still have occurred undetected by acoustic emission. An alternative failure sequence is proposed: an incubation process for preferential moisture ingress leads to a local decrease in interfacial toughness, thus allowing fast fracture driven by stored strain energy.

  7. Reticulated acanthoma with sebaceous differentiation: another sebaceous neoplasm associated with Muir-Torre syndrome?

    PubMed

    Shon, Wonwoo; Wolz, Michael M; Newman, Catherine C; Bridges, Alina G

    2014-11-01

    Reticulated acanthoma with sebaceous differentiation (RASD) represents a rare benign cutaneous epithelial neoplasm with sebaceous differentiation. There has been much speculation about the relationship between RASD and Muir-Torre syndrome (MTS). We report a 53 year-old man who presented with RASD in addition to a prior history of sebaceous adenomas. Immunohistochemically, the tumour cells in the RASD and sebaceous adenomas showed a significantly reduced MSH6 protein expression, whereas there was no loss of MLH1, MSH2 and PMS2. This benign neoplasm, which can be mistaken for various other cutaneous lesions with sebaceous differentiation, deserves wider recognition for its possible association with MTS.

  8. Reticulated acanthoma with sebaceous differentiation. Lack of association with Muir-Torre syndrome.

    PubMed

    Haake, Dana L; Minni, John P; Nowak, Michael; Abenoza, Pascual; Nousari, Carlos H

    2009-06-01

    We hereby report a case of a reticulated acanthoma with sebaceous differentiation (RASD), a rare and often mislabeled benign lesion that is characterized by epidermal acanthosis and clusters of sebocytes in a reticulated seborrheic keratosis-like pattern. The presence of multiple sebaceous tumors, most notably cystic sebaceous adenomas and keratoacanthomas, has been associated with Muir-Torre syndrome (MTS). Although very rare, cases of RASD have been reported with MTS, which potentially offers profound clinical significance to this neoplasm. This case further supports the lack of association of MTS with RASD.

  9. Biogeography of Burkholderia pseudomallei in the Torres Strait Islands of Northern Australia

    PubMed Central

    Baker, Anthony; Mayo, Mark; Owens, Leigh; Burgess, Graham; Norton, Robert; McBride, William John Hannan; Currie, Bart J.

    2013-01-01

    It has been hypothesized that biogeographical boundaries are a feature of Burkholderia pseudomallei ecology, and they impact the epidemiology of melioidosis on a global scale. This study examined the relatedness of B. pseudomallei sourced from islands in the Torres Strait of Northern Australia to determine if the geography of isolated island communities is a determinant of the organisms' dispersal. Environmental sampling on Badu Island in the Near Western Island cluster recovered a single clone. An additional 32 clinical isolates from the region were sourced. Isolates were characterized using multilocus sequence typing and a multiplex PCR targeting the flagellum gene cluster. Gene cluster analysis determined that 69% of the isolates from the region encoded the ancestral Burkholderia thailandensis-like flagellum and chemotaxis gene cluster, a proportion significantly lower than that reported from mainland Australia and consistent with observations of isolates from southern Papua New Guinea. A goodness-of-fit test indicated that there was geographic localization of sequence types throughout the archipelago, with the exception of Thursday Island, the economic and cultural hub of the region. Sequence types common to mainland Australia and Papua New Guinea were identified. These findings demonstrate for the first time an environmental reservoir for B. pseudomallei in the Torres Strait, and multilocus sequence typing suggests that the organism is not randomly distributed throughout this region and that seawater may provide a barrier to dispersal of the organism. Moreover, these findings support an anthropogenic dispersal hypothesis for the spread of B. pseudomallei throughout this region. PMID:23698533

  10. Striking association between urinary cadmium level and albuminuria among Torres Strait Islander people with diabetes

    SciTech Connect

    Haswell-Elkins, Melissa Satarug, Soisungwan; O'Rourke, Peter; Moore, Michael; Ng, Jack; McGrath, Victor; Walmby, Maria

    2008-03-15

    Objectives: Indigenous people of the Torres Strait (Australia) have greater potential for cadmium exposure and renal damage than other Australians due to high cadmium in some traditional seafood and a high prevalence of Type 2 diabetes, hypertension, smoking, and obesity. This study explored associations between albuminuria and an index of cadmium exposure (urinary cadmium excretion) in the presence and absence of Type 2 diabetes. Research design and methods: Two population-based, cross-sectional studies were undertaken in the Torres Strait to obtain data on body mass index (BMI), blood pressure, chronic disease, smoking, urinary cadmium, and albumin creatinine ratio (ACR). Results: Age- and BMI-adjusted urinary cadmium levels were significantly higher (p<0.01) among people with diabetes and albuminuria (n=22, geometric mean (GM) 1.91 {mu}g Cd/g creatinine) compared to those with diabetes and normal ACR (n=21, GM 0.74 {mu}g Cd/g creatinine). Urinary cadmium was also strongly associated (p<0.001) with ACR among people with diabetes in regression models and remained significant after controlling for age, sex, BMI, smoking status, and hypertension (or continuous systolic and diastolic measurements). Conclusions: While the study has methodological limitations and the nature of the association is unclear, the striking dose-dependent links between markers of cadmium exposure and of Type 2 diabetic nephropathy highlight the need for further definitive research on the health effects of cadmium in the presence of diabetes.

  11. Biogeography of Burkholderia pseudomallei in the Torres Strait Islands of Northern Australia.

    PubMed

    Baker, Anthony; Mayo, Mark; Owens, Leigh; Burgess, Graham; Norton, Robert; McBride, William John Hannan; Currie, Bart J; Warner, Jeffrey

    2013-08-01

    It has been hypothesized that biogeographical boundaries are a feature of Burkholderia pseudomallei ecology, and they impact the epidemiology of melioidosis on a global scale. This study examined the relatedness of B. pseudomallei sourced from islands in the Torres Strait of Northern Australia to determine if the geography of isolated island communities is a determinant of the organisms' dispersal. Environmental sampling on Badu Island in the Near Western Island cluster recovered a single clone. An additional 32 clinical isolates from the region were sourced. Isolates were characterized using multilocus sequence typing and a multiplex PCR targeting the flagellum gene cluster. Gene cluster analysis determined that 69% of the isolates from the region encoded the ancestral Burkholderia thailandensis-like flagellum and chemotaxis gene cluster, a proportion significantly lower than that reported from mainland Australia and consistent with observations of isolates from southern Papua New Guinea. A goodness-of-fit test indicated that there was geographic localization of sequence types throughout the archipelago, with the exception of Thursday Island, the economic and cultural hub of the region. Sequence types common to mainland Australia and Papua New Guinea were identified. These findings demonstrate for the first time an environmental reservoir for B. pseudomallei in the Torres Strait, and multilocus sequence typing suggests that the organism is not randomly distributed throughout this region and that seawater may provide a barrier to dispersal of the organism. Moreover, these findings support an anthropogenic dispersal hypothesis for the spread of B. pseudomallei throughout this region.

  12. Theoretical modeling of GHRS observations of the Of/WN-type star R136a5

    NASA Technical Reports Server (NTRS)

    Koter, Alex DE; Hubeny, Ivan; Heap, Sara R.; Lanz, Thierry

    1994-01-01

    We present a theoretical analysis of the Hubble Space Telescope (HST) Goddard High Resolution Spectrograph (GHRS) spectrum of R136a5, an O3fWN star in the R136a cluster in 30 Doradus. Using non-LTE extended and expanding model atmospheres, we find a surprisingly high mass-loss rate dot-M = 1.8 +/- 0.5 x 10(exp -5) solar mass/yr and an effective temperature T(sub eff) = 42.5 +/- 2.5 kK. With the observed visual magnitude, this implies a radius R(sub *) = 17 +/- 2 solar radius and a solar luminosity L = 8.5 +/- 1 x 10(exp 5) solar luminosity. We discuss possible sources of the uncertainties in the derived stellar parameters and conclude that the effective temperature may be underestimated; however, if so, the value of the mass-loss rate would not be affected.

  13. The genetic basis of Muir-Torre syndrome includes the hMLH1 locus

    SciTech Connect

    Bapat, B.; Xia, L.; Mitri, A.

    1996-09-01

    Muir-Torre syndrome (MTS) (McKusick 158320) is an autosomal dominant disorder characterized by the development of sebaceous gland tumors and skin cancers, including keratoacanthomas and basal cell carcinomas. Affected family members may manifest a wide spectrum of internal malignancies, which include colorectal, endometrial, urologic, and upper gastrointestinal neoplasms. Sebaceous gland tumors, which are rare in the general population, are considered to be the hallmark of MTS and may arise prior to the development of other visceral cancers. Despite the high incidence of synchronous and metachronous tumors, prognosis is often favorable. Hereditary nonpolyposis colorectal cancer (HNPCC) is one of the most common autosomal dominantly inherited colorectal cancer susceptibility syndromes. In some HNPCC families, extracolonic tumors of the endometrium, ovary, small bowel, and renal and biliary tract occur at an increased frequency. On the basis of similarities in clinical symptoms of MTS and HNPCC, it is proposed that these two syndromes may have a common genetic basis. 24 refs., 2 figs.

  14. Antitumor Activity of Prosopis glandulosa Torr. on Ehrlich Ascites Carcinoma (EAC) Tumor Bearing Mice

    PubMed Central

    Senthil Kumar, Raju; Rajkapoor, Balasubramanian; Perumal, Perumal; Dhanasekaran, Thangavel; Alvin Jose, Manonmani; Jothimanivannan, Chennakesavalu

    2011-01-01

    The antitumor activity of ethanol extract of Prosopis glandulosa Torr. (EPG) was evaluated against Ehrlich ascites carcinoma (EAC) tumor model in Swiss albino mice on dose dependent manner. The activity was assessed using survival time, average increase in body weight, hematological parameters and solid tumor volume. Oral administration of EPG at the dose of 100, 200 and 400 mg/Kg, significantly (p < 0.001) increased the survival time and decreased the average body weight of the tumor bearing mice. After 14 days of inoculation, EPG was able to reverse the changes in the hematological parameters, protein and PCV consequent to tumor inoculation. Oral administration of EPG was effective in reducing solid tumor mass development induced by EAC cells. The results indicate that EPG possess significant antitumor activity on dose dependent manner. PMID:24250382

  15. Later Middle Pleistocene human remains from the Almonda Karstic system, Torres Novas, Portugal.

    PubMed

    Trinkaus, Erik; Marks, Anthony E; Brugal, Jean Philip; Bailey, Shara E; Rink, W Jack; Richter, Daniel

    2003-09-01

    Later Middle Pleistocene archeological deposits of the Galeria Pesada (Gruta da Aroeira), Almonda Karstic System, Torres Novas, Portugal, yielded two archaic human teeth, a mandibular canine and a maxillary third molar. The C(1)presents moderate and asymmetrical shoveling with a stout root. The slightly worn M(3)exhibits at least four cusps with a large hypocone, three roots with large radicular plates, and an absence of taurodontism. They are moderately large for later Middle Pleistocene humans in their buccolingual crown diameters, although the M(3)mesiodistal diameter is modest. The C(1)exhibits labial calculus and multiple linear hypoplastic defects, but the M(3)is lesion free. Both teeth are morphologically similar to those of other Middle Pleistocene European humans and reinforce a pattern of dental hypertrophy among these archaic Homo.

  16. Macrovascular disease risk factors and insulin resistance in Aboriginal and Torres Strait Islander people.

    PubMed

    O'Dea, Kerin; Rowley, Kevin G

    2002-01-01

    It has been proposed that insulin resistance (IR) underlies a cluster of cardiovascular disease (CVD) risk factors constituting a "metabolic syndrome." CVD is a leading cause of premature mortality among indigenous Australians. In a group of younger (15-44 years, fasting glucose <7.8 mmol/l) Aboriginal (n=643) and Torres Strait Islander (n=220) people participating in community-based risk factor surveys, we identified high prevalences of metabolic syndrome components: glucose intolerance, dyslipidaemia, hypertension, and IR. There were inconsistent associations of IR with other risk factors, and the data do not support a direct causal relationship between insulin and other metabolic variables. Rather, metabolic syndrome components may arise from social and environmental factors interacting with behavioural and biochemical factors in individuals.

  17. High risk alcohol-related trauma among the Aboriginal and Torres Strait Islanders in the Northern Territory

    PubMed Central

    2012-01-01

    High risk drinking is linked with high rates of physical harm. The reported incidence of alcohol - related trauma among Aboriginal and Torres Strait Islander people in the Northern Territory is the highest in the world. Facial fractures are common among young Aboriginal and Torres Strait Islanders. They are often linked with misuse of alcohol in the Northern Territory and are frequently secondary to assault. This review focuses on alcohol-related trauma in the Territory and draws attention to an urgent need for preventative health approach to address this critical issue. PMID:22862897

  18. Development of a Humane Slaughter Device for Green Turtles for Use by Traditional Owners in the Torres Strait Islands, Australia.

    PubMed

    Flint, Mark; Mills, Paul C; Loban, Frank; Simpson, Tristan; Lui, Stan; Fujii, Ronald; Whap, Don; Flint, Jaylene B; Owen, Helen

    2017-01-01

    Marine turtles are caught and slaughtered for consumption as part of traditional indigenous community harvest in Australia as well as in many countries in which marine turtles can be found. However, changes to the Animal Care and Protection Act 2001 in 2012 resulted in Australian indigenous hunters becoming potentially liable to prosecution for using traditional practices to slaughter marine turtles. To provide indigenous hunters with an alternative scientifically tested method to hunt, we developed and tested a humane method as an option to use in indigenous communities. Between 2012 and 2015, a device was developed, tested on 11 carcasses to determine effectiveness and repeatability, used on 5 anaesthetised animals independently diagnosed as candidates for euthanasia, and ultimately used on 2 healthy, conscious animals as part of normal indigenous community subsistence harvesting under observation before being left with the communities for use. Feedback was sought from the communities on the suitability and potential adoption of the device. The device effectively ablated the hind brain and severed the spinal cord when deployed in 81% (9/11) of the tested carcasses, with death in 100% (5/5) of turtles, on average, within 78 seconds of deployment on anaesthetised turtles and death in 100% (2/2) of turtles, on average, within 144 seconds when deployed on healthy turtles within community. Failure to ablate the hindbrain and sever the spinal cord in the cadaver cases was due to incorrect deployment of the device. This device showed promise as an alternative euthanasia method available to indigenous communities of the Torres Straits. Further work is required to encourage acceptance by hunters.

  19. Development of a Humane Slaughter Device for Green Turtles for Use by Traditional Owners in the Torres Strait Islands, Australia

    PubMed Central

    Flint, Mark; Mills, Paul C.; Loban, Frank; Simpson, Tristan; Lui, Stan; Fujii, Ronald; Whap, Don; Flint, Jaylene B.; Owen, Helen

    2017-01-01

    Marine turtles are caught and slaughtered for consumption as part of traditional indigenous community harvest in Australia as well as in many countries in which marine turtles can be found. However, changes to the Animal Care and Protection Act 2001 in 2012 resulted in Australian indigenous hunters becoming potentially liable to prosecution for using traditional practices to slaughter marine turtles. To provide indigenous hunters with an alternative scientifically tested method to hunt, we developed and tested a humane method as an option to use in indigenous communities. Between 2012 and 2015, a device was developed, tested on 11 carcasses to determine effectiveness and repeatability, used on 5 anaesthetised animals independently diagnosed as candidates for euthanasia, and ultimately used on 2 healthy, conscious animals as part of normal indigenous community subsistence harvesting under observation before being left with the communities for use. Feedback was sought from the communities on the suitability and potential adoption of the device. The device effectively ablated the hind brain and severed the spinal cord when deployed in 81% (9/11) of the tested carcasses, with death in 100% (5/5) of turtles, on average, within 78 seconds of deployment on anaesthetised turtles and death in 100% (2/2) of turtles, on average, within 144 seconds when deployed on healthy turtles within community. Failure to ablate the hindbrain and sever the spinal cord in the cadaver cases was due to incorrect deployment of the device. This device showed promise as an alternative euthanasia method available to indigenous communities of the Torres Straits. Further work is required to encourage acceptance by hunters. PMID:28076432

  20. MSH-2 and MLH-1 Protein Expression in Muir Torre Syndrome-Related and Sporadic Sebaceous Neoplasms

    PubMed Central

    Morales-Burgos, Adisbeth; Sánchez, Jorge L.; Figueroa, Luz D.; De Jesús-Monge, Wilfredo E.; Cruz-Correa, Marcia R.; González-Keelan, Carmen; Nazario, Cruz María

    2009-01-01

    Background Muir-Torre Syndrome (MTS) is a rare autosomal-dominant disorder characterized by the predisposition to both sebaceous neoplasm and internal malignancies. MTS-associated sebaceous neoplasms reveal mutations in DNA mismatch repair (MMR) genes and microsatellite instability. A significant part of MTS patients represents a phenotypic variant, the hereditary nonpolyposis colorectal cancer (HNPCC). A strong correlation between microsatellite instability and immunostaining has been demonstrated. The early recognition of sebaceous neoplasm as part of MTS, and their differentiation from sporadic sebaceous neoplasm may have an important application in a clinical setting. The absence of MLH-1 or MSH-2 expression by immunostaining identifies tumors with mismatch repair deficiency. Objectives Our aim is to determine whether an immunohistochemical approach, targeting DNA repair proteins MSH-2 and MLH-1 in MTS-related sebaceous neoplasm and their sporadic counterparts, can be used for their identification. Methods We examined 15 sebaceous neoplasms (including 6 internal malignancy- associated sebaceous neoplasms and 8 sporadic sebaceous neoplasms) from 11 patients for the expression of MSH-2 and MLH-1 by immunohistochemistry. Results Four of 5 internal malignancy-associated sebaceous neoplasms showed loss of expression of MSH-2 or MLH-1. Correlation of the immunostaining pattern of the sebaceous neoplasms and the patients’ positive history of colon carcinoma was 80%. Seven of 8 sporadic sebaceous neoplasms showed a positive expression of MSH-2 and MLH-1. The prevalence for loss of expression of MMR proteins in sebaceous neoplasms was 38.5%. MMR immunostaining had 87.5% specificity and 80% sensitivity. Limitations This study is limited by a small sample size, and by bias selection due to the use of non nationwide data-base as the resource of cases. Conclusions Our findings demonstrate that immunohistochemical testing for internal malignancy-associated sebaceous

  1. The potential impact of bedform migration on seagrass communities in Torres Strait, northern Australia

    NASA Astrophysics Data System (ADS)

    Daniell, James J.; Harris, Peter T.; Hughes, Michael G.; Hemer, Mark; Heap, Andrew

    2008-09-01

    Seagrass communities in the northwest of Torres Strait are known to disappear episodically over broad areas. Sediment mobility surveys were undertaken within two study areas during the monsoon and trade wind seasons, in the vicinity of Turnagain Island, to find out if the migration of bedforms could explain this disappearance. The two study areas covered sand bank and sand dune environments to compare and contrast their migration characteristics. Repeat multibeam sonar surveys were used to measure dune-crest migration during each season. Our results show that seagrass beds occur in the troughs of sediment-starved dunes, but no seagrass occurs in association with full-bedded dunes that are superimposed on large sand bank features. The coincidence of seagrass beds with the sediment-starved dunes is in spite of the fact that they migrate faster (0.59 m day -1) than full-bedded dunes (0.13 m day -1), which indicates that some other factor (other than dune migration rate) limits seagrass growth within Torres Strait. We suggest that seagrasses are unable to colonise full-bedded dunes because of the semi-continuously transported sand that characterises this environment. In contrast, the troughs of sediment-starved dunes experience only limited bedload transport and are less hostile for seagrasses. A conceptual model is presented to explain the occurrence of seagrass beds in relation to their proximity to migrating sand dunes. Based on our analysis, we conclude that the widespread dieback of seagrasses documented for the Turnagain Island region was not caused by dune migration.

  2. Seagrass-Watch: Engaging Torres Strait Islanders in marine habitat monitoring

    NASA Astrophysics Data System (ADS)

    Mellors, Jane E.; McKenzie, Len J.; Coles, Robert G.

    2008-09-01

    Involvement in scientifically structured habitat monitoring is a relatively new concept to the peoples of Torres Strait. The approach we used was to focus on awareness, and to build the capacity of groups to participate using Seagrass-Watch as the vehicle to provide education and training in monitoring marine ecosystems. The project successfully delivered quality scientifically rigorous baseline information on the seasonality of seagrasses in the Torres Strait—a first for this region. Eight seagrass species were identified across the monitoring sites. Seagrass cover varied within and between years. Preliminary evidence indicated that drivers for seagrass variability were climate related. Generally, seagrass abundance increased during the north-west monsoon ( Kuki), possibly a consequence of elevated nutrients, lower tidal exposure times, less wind, and higher air temperatures. Low seagrass abundance coincided with the presence of greater winds and longer periods of exposure at low tides during the south-east trade wind season ( Sager). No seasonal patterns were apparent when frequency of disturbance from high sedimentation and human impacts was high. Seagrass-Watch has been incorporated in to the Thursday Island High School's Marine Studies Unit ensuring continuity of monitoring. The students, teachers, and other interested individuals involved in Seagrass-Watch have mastered the necessary scientific procedures to monitor seagrass meadows, and developed skills in coordinating a monitoring program and skills in mentoring younger students. This has increased the participants' self-esteem and confidence, and given them an insight into how they may participate in the future management of their sea country.

  3. Heterogeneous Reaction of ClONO2(g) + NaCl(s) to Cl2(g) + NaNO3(s)

    NASA Technical Reports Server (NTRS)

    Timonen, Raimo S.; Chu, Liang T.; Leu, Ming-Taun; Keyser, Leon F.

    1994-01-01

    The heterogeneous reaction of ClON02 + NaCl yields Cl2 + NaNO3 (eq 1) was investigated over a temperature range 220-300 K in a flow-tube reactor interfaced with a differentially pumped quadrupole mass spectrometer. Partial pressures of ClON02 in the range 10(exp -8) - 10(exp -5) Torr were used. Granule sizes and surface roughness of the NaCl substrates were determined by using a scanning electron microscope, and in separate experiments, surface areas of the substrates were measured by using BET analysis of gas-adsorption isotherms. For dry NaCl substrates, both the decay rates of ClON02 and the growth rates Of C12 were used to obtain reaction probabilities, gamma(sub l) = (4.6 +/- 3.0) x 10(exp -3) at 296 K and (6.7 +/- 3.2) x 10(exp -1) at 225 K, after considering the internal surface area, The error bars represent 1 standard deviation. The Cl2 yield based on the ClONO2 reacted was measured to be 1.0 +/- 0.2. In order to mimic the conditions encountered in the lower stratosphere, the effect of water vapor pressures between 5 x 10(exp -5) and 3 x 10(exp -4) Torr on reaction 1 was also studied. With added H20, reaction probabilities, gamma = (4.1 +/- 2.1) x 10(exp -3) at 296 K and (4.7 +/- 2.9) x 10(exp -3) at 225 K, were obtained. A trace of HOCl, the reaction product from the ClON02 + H20 yield HOCl + HN03 reaction, was observed in addition to the C12 product from reaction 1. The implications of this result for the enhancement of hydrogen chloride in the stratosphere after the El Chichon volcanic eruption and for the marine troposphere are discussed.

  4. Evolution of Intrinsic Scatter in the SFR-Stellar Mass Correlation at 0.5 less than z Less Than 3

    NASA Technical Reports Server (NTRS)

    Kurczynski, Peter; Gawiser, Eric; Acquaviva, Viviana; Bell, Eric F.; Dekel, Avishai; De Mello, Duilia F.; Ferguson, Henry C.; Gardner, Jonathan P.; Grogin, Norman A.

    2016-01-01

    We present estimates of intrinsic scatter in the star formation rate (SFR)--stellar mass (M*) correlation in the redshift range 0.5 less than z less than 3.0 and in the mass range 10(exp 7) less than M* less than 10(exp 11) solar mass. We utilize photometry in the Hubble Ultradeep Field (HUDF12) and Ultraviolet Ultra Deep Field (UVUDF) campaigns and CANDELS/GOODS-S and estimate SFR, M* from broadband spectral energy distributions and the best-available redshifts. The maximum depth of the UDF photometry (F160W 29.9 AB, 5 sigma depth) probes the SFR--M* correlation down to M* approximately 10(exp 7) solar mass, a factor of 10-100 x lower in M* than previous studies, and comparable to dwarf galaxies in the local universe. We find the slope of the SFR-M* relationship to be near unity at all redshifts and the normalization to decrease with cosmic time. We find a moderate increase in intrinsic scatter with cosmic time from 0.2 to 0.4 dex across the epoch of peak cosmic star formation. None of our redshift bins show a statistically significant increase in intrinsic scatter approximately 100 Myr. Our results are consistent with a picture of gradual and self-similar assembly of galaxies across more than three orders of magnitude in stellar mass from as low as 10(exp 7) solar mass.

  5. Everywhere and Nowhere: Invisibility of Aboriginal and Torres Strain Islander Contact Languages in Education and Indigenous Language Contexts

    ERIC Educational Resources Information Center

    Sellwood, Juanita; Angelo, Denise

    2013-01-01

    The language ecologies of Aboriginal and Torres Strait Islander communities in Queensland are characterised by widespread language shift to contact language varieties, yet they remain largely invisible in discourses involving Indigenous languages and education. This invisibility--its various causes and its many implications--are explored through a…

  6. Establishing a Community-Controlled Multi-Institutional Centre for Clinical Research Excellence in Aboriginal and Torres Strait Islander Health

    ERIC Educational Resources Information Center

    Pearce, Leilani; Fredericks, Bronwyn

    2007-01-01

    The Queensland Aboriginal and Islander Health Council (QAIHC) lead and govern the Centre for Clinical Research Excellence (CCRE), which has a focus on circulatory and associated conditions in urban Aboriginal and Torres Strait Islander communities. The CCRE is a partnership between QAIHC and Monash University, the Queensland University of…

  7. Effects of Community Singing Program on Mental Health Outcomes of Australian Aboriginal and Torres Strait Islander People: A Meditative Approach.

    PubMed

    Sun, Jing; Buys, Nicholas

    2015-05-14

    Purpose . To evaluate the impact of a meditative singing program on the health outcomes of Aboriginal and Torres Strait Islander people. Design . The study used a prospective intervention design. Setting . The study took place in six Aboriginal and Torres Strait Islander communities and Community Controlled Health Services in Queensland, Australia. Subjects . Study participants were 210 Australian Aboriginal and Torres Strait Islander adults aged 18 to 71 years, of which 108 were in a singing intervention group and 102 in a comparison group. Intervention . A participative community-based community singing program involving weekly singing rehearsals was conducted over an 18-month period. Measures . Standardized measures in depression, resilience, sense of connectedness, social support, and singing related quality of life were used. Analysis . The general linear model was used to compare differences pre- and postintervention on outcome variables, and structural equation modeling was used to examine the pathway of the intervention effect. Results . Results revealed a significant reduction in the proportion of adults in the singing group classified as depressed and a concomitant significant increase in resilience levels, quality of life, sense of connectedness, and social support among this group. There were no significant changes for these variables in the comparison group. Conclusions . The participatory community singing approach linked to preventative health services was associated with improved health, resilience, sense of connectedness, social support, and mental health status among Aboriginal and Torres Strait Islander adults.

  8. Hearing the Voice of Remote Aboriginal and Torres Strait Islander Training Stakeholders Using Research Methodologies and Theoretical Frames of Reference

    ERIC Educational Resources Information Center

    Guenther, John; Osborne, Sam; Arnott, Allan; McRae-Williams, Eva

    2017-01-01

    Researchers in remote Aboriginal and Torres Strait Islander contexts within Australia are frequently faced with the challenges of working in an intercultural space where channels of communication are garbled with interference created by the complexities of misunderstood worldviews, languages, values and expectations. A concern of many researchers…

  9. The Fallacy of the Bolted Horse: Changing Our Thinking about Mature-Age Aboriginal and Torres Strait Islander University Students

    ERIC Educational Resources Information Center

    Plater, Suzanne; Mooney-Somers, Julie; Lander, Jo

    2015-01-01

    The aim of this article is to critically review and analyse the public representations of mature-age university students in developed and some developing nations and how they compare to the public representations of mature-age Aboriginal and Torres Strait Islander university students in Australia ("students" also refers to graduates…

  10. Diabetic Foot Care: Developing Culturally Appropriate Educational Tools for Aboriginal and Torres Strait Islander Peoples in the Northern Territory, Australia.

    ERIC Educational Resources Information Center

    Watson, Jennifer; Obersteller, Elizabeth A.; Rennie, Linda; Whitbread, Cherie

    2001-01-01

    Participatory research in Australia's Northern Territory sought opinions from nurses, general practitioners, Aboriginal health workers, and Aboriginal and Torres Strait Islanders on the development of culturally relevant foot care education for Indigenous people with diabetes. They decided to use a visual approach (posters and flip charts) to…

  11. Mobile Devices for Tertiary Study--Philosophy Meets Pragmatics for Remote Aboriginal and Torres Strait Islander Women

    ERIC Educational Resources Information Center

    Townsend, Philip

    2015-01-01

    This paper outlines PhD research which suggests mobile learning fits the cultural philosophies and roles of Aboriginal and Torres Strait Islander women who are preservice teachers in the very remote Australian communities where the research was conducted. The problem which the research addresses is the low completion rates for two community-based…

  12. Glacial geomorphology of the Torres del Paine region (southern Patagonia): Implications for glaciation, deglaciation and paleolake history

    NASA Astrophysics Data System (ADS)

    García, Juan-Luis; Hall, Brenda L.; Kaplan, Michael R.; Vega, Rodrigo M.; Strelin, Jorge A.

    2014-01-01

    The processes affecting paleoclimate variability and Pleistocene glacial landscape development in the southern mid-latitudes remain poorly understood, in part because of the scarcity of comprehensive, well-studied records. Glacial landforms are invaluable for reconstructing past ice-sheet, climate, and associated environmental changes along the southern Andes, but there are significant spatial and temporal gaps in existing data. In this paper, we present new geomorphic and sedimentologic analyses, including surficial maps, for the Torres del Paine region (51°S, 73°W), southern South America. Our findings provide a new framework for understanding changes in the regional glacier history and Pleistocene landscape development. Glacial extent during the local last glacial maximum (LGM) remains unknown but new chronological data supported by geomorphic evidence afford evidence for a larger ice sheet at Torres del Paine than previously assumed. Deglaciation from the local LGM was underway by 17,400 ± 200 (1σ) cal. yr. BP. As opposed to previous suggestions, we have found that most of the moraines fringing the lakes in the Torres del Paine national park were deposited during a late-glacial expansion that occurred between 14,100 and 12,500 cal. yr. BP. Late-glacial advances also have been documented recently for the Última Esperanza and Lago Argentino basins to the south and north of Torres del Paine, respectively, suggesting an overall regional ice response to a climate signal. The Tehuelche paleolake accompanied each of the ice-sheet fluctuations in Torres del Paine. New data document at least three main phases of this paleolake, which drained eastward to the Atlantic Ocean, while the Andes gaps were blocked with ice. During the late phase of glacial lake formation, when water levels reached 125-155 m a.s.l., the lake likely merged with paleolake Consuelo in the Última Esperanza area at the end of the last glaciation. Lake Tehuelche in Torres del Paine had drained

  13. Observations of Environmental Quenching in Groups in the 11 GYR Since z = 2.5: Different Quenching For Central and Satellite Galaxies

    NASA Technical Reports Server (NTRS)

    Tal, Tomer; Dekel, Avishai; Marchesini, Danilo; Momcheva, Ivelina; Nelson, Erica J.; Patel, Shannon G.; Quadri, Ryan F.; Rix, Hans-Walter; Skelton, Rosalind E.; Wake, David A.; Whitaker, Katherine E.; Oesch, Pascal; Muzzin, Adam; Brammer, Gabriel B.; vanDokkum, Peter G.; Franx, Marijn; Illingworth, Garth D.; Leja, Joel; Magee, Daniel

    2014-01-01

    We present direct observational evidence for star formation quenching in galaxy groups in the redshift range 0 less than z less than 2.5. We utilize a large sample of nearly 6000 groups, selected by fixed cumulative number density from three photometric catalogs, to follow the evolving quiescent fractions of central and satellite galaxies over roughly 11 Gyr. At z approximately 0, central galaxies in our sample range in stellar mass from Milky Way/M31 analogs (M=6.5x10(exp 10) M/solar mass) to nearby massive ellipticals (M=1.5x10(exp 11) M/solar mass). Satellite galaxies in the same groups reach masses as low as twice that of the Large Magellanic Cloud (M=6.5x10(exp 9) M/solar mass). Using statistical background subtraction, we measure the average rest-frame colors of galaxies in our groups and calculate the evolving quiescent fractions of centrals and satellites over seven redshift bins. Our analysis shows clear evidence for star formation quenching in group halos, with a different quenching onset for centrals and their satellite galaxies. Using halo mass estimates for our central galaxies, we find that star formation shuts off in centrals when typical halo masses reach between 10(exp 12) and 10(exp 13) M/solar mass, consistent with predictions from the halo quenching model. In contrast, satellite galaxies in the same groups most likely undergo quenching by environmental processes, whose onset is delayed with respect to their central galaxy. Although star formation is suppressed in all galaxies over time, the processes that govern quenching are different for centrals and satellites. While mass plays an important role in determining the star formation activity of central galaxies, quenching in satellite galaxies is dominated by the environment in which they reside.

  14. Kinetics study of reactions of α-pinene and β-pinene with hydroxyl radical at 1-8 Torr and 240-340 K using the relative rate/discharge flow/mass spectrometry method.

    PubMed

    Montenegro, Anthony; Ishibashi, Jacob S A; Lam, Phuong; Li, Zhuangjie

    2012-12-13

    The kinetics of reactions of α-pinene and β-pinene with hydroxyl radicals (OH) has been investigated at 1-8 Torr and 240-340 K using the relative rate/discharge flow/mass spectrometry (RR/DF/MS) technique. Our kinetic results indicate that at 298 K the rate constant of the reactions of α-pinene and β-pinene with hydroxyl radicals has little pressure dependence over the 1-8 Torr pressure range, suggesting that the high pressure limit of these reactions has been reached at 1 Torr. The rate constant of these reactions was found to negatively depend on the temperature at 240-340 K, which is consistent with previous investigations using different techniques. The Arrhenius equation for α-pinene and β-pinene with hydroxyl radical was determined to be k(α-pinene) = (1.21 ± 0.20) × 10(-11)exp[(441 ± 46)/T] cm(3) molecule(-1) s(-1) and k(β-pinene) = (1.65 ± 0.10) × 10(-11)exp[(470 ± 17)/T] cm(3) molecule(-1) s(-1), respectively. Using the rate constant determined at 277 K in this work and the average global hydroxyl radical concentration, the atmospheric lifetime of α-pinene and β-pinene was estimated to be 5.8 and 3.8 h, respectively.

  15. Aboriginal and Torres Strait Islander Worldviews and Cultural Safety Transforming Sexual Assault Service Provision for Children and Young People

    PubMed Central

    Funston, Leticia

    2013-01-01

    Child Sexual Assault (CSA) in Aboriginal and Torres Strait Islander communities is a complex issue that cannot be understood in isolation from the ongoing impacts of colonial invasion, genocide, assimilation, institutionalised racism and severe socio-economic deprivation. Service responses to CSA are often experienced as racist, culturally, financially and/or geographically inaccessible. A two-day forum, National Yarn Up: Sharing the Wisdoms and Challenges of Young People and Sexual Abuse, was convened by sexual assault services to identify the main practice and policy concerns regarding working with Aboriginal and Torres Strait Islander children and young people (C&YP), families and communities in the context of CSA. The forum also aimed to explore how services can become more accountable and better engaged with the communities they are designed to support. The forum was attended by eighty invited Aboriginal and Torres Strait Islander and non-Aboriginal youth sexual assault managers and workers representing both “victim” and “those who sexually harm others” services. In keeping with Aboriginal Community-Based Research methods forum participants largely directed discussions and contributed to the analysis of key themes and recommendations reported in this article. The need for sexual assault services to prioritise cultural safety by meaningfully integrating Aboriginal and Torres Strait Islander Worldviews emerged as a key recommendation. It was also identified that collaboration between “victims” and “those who sexually harm” services are essential given Aboriginal and Torres Strait Islander C&YP who sexually harm others may have also been victims of sexual assault or physical violence and intergenerational trauma. By working with the whole family and community, a collaborative approach is more likely than the current service model to develop cultural safety and thus increase the accessibility of sexual assault services. PMID:23975109

  16. Using Participatory Action Research to Share Knowledge of the Local Environment and Climate Change: Case Study of Erub Island, Torres Strait

    ERIC Educational Resources Information Center

    McNamara, Karen Elizabeth; McNamara, John Patrick

    2011-01-01

    Reading seasons and environments has been a long-held practice for Torres Strait Islanders through their close relationships with their islands and seas. This research project worked with elders on Erub (Darnley) Island, in the eastern group of islands in the Torres Strait, to document and synthesise their knowledge of seasonal patterns and…

  17. Stratigraphical framework of basaltic lavas in Torres Syncline main valley, southern Parana-Etendeka Volcanic Province

    NASA Astrophysics Data System (ADS)

    Rossetti, Lucas M.; Lima, Evandro F.; Waichel, Breno L.; Scherer, Claiton M.; Barreto, Carla J.

    2014-12-01

    The Paraná-Etendeka Volcanic Province records the volcanism of the Early Cretaceous that precedes the fragmentation of the South-Gondwana supercontinent. Traditionally, investigations of these rocks prioritized the acquisition of geochemical and isotopic data, considering the volcanic stack as a monotonous succession of tabular flows. Torres Syncline is a tectonic structure located in southern Brazil and where the Parana-Etendeka basalts are well preserved. This work provides a detailed analysis of lithofacies and facies architecture, integrated to petrographic and geochemical data. We identified seven distinct lithofacies grouped into four facies associations related to different flow morphologies. The basaltic lava flows in the area can be divided into two contrasting units: Unit I - pahoehoe flow fields; and Unit II - simple rubbly flows. The first unit is build up by innumerous pahoehoe lava flows that cover the sandstones of Botucatu Formation. These flows occur as sheet pahoehoe, compound pahoehoe, and ponded lavas morphologies. Compound lavas are olivine-phyric basalts with intergranular pyroxenes. In ponded lavas and cores of sheet flows coarse plagioclase-phyric basalts are common. The first pahoehoe lavas are more primitive with higher contents of MgO. The emplacement of compound pahoehoe flows is related to low volume eruptions, while sheet lavas were emplaced during sustained eruptions. In contrast, Unit II is formed by thick simple rubbly lavas, characterized by a massive core and a brecciated/rubbly top. Petrographically these flows are characterized by plagioclase-phyric to aphyric basalts with high density of plagioclase crystals in the matrix. Chemically they are more differentiated lavas, and the emplacement is related to sustained high effusion rate eruptions. Both units are low TiO2 and have geochemical characteristics of Gramado magma type. The Torres Syncline main valley has a similar evolution when compared to other Large Igneous Provinces

  18. Vacancy related defects in La{sub 0.5}Sr{sub 0.5}CoO{sub 3-{delta}} thin films

    SciTech Connect

    Keeble, D.J.; Krishnan, A.; Nielsen, B.

    1996-12-31

    Laser ablated La{sub 0.5}Sr{sub 0.5}CoO{sub 3-{delta}} thin films have been studied by Doppler-broadening-detected positron annihilation using a variable-energy positron beam. The oxygen partial pressure during cooling from the growth temperature was altered through the range 760 torr to 10{sup -5} torr to change the oxygen non-stoichiometry of the films. The measured Doppler broadened lineshape parameter S was found to increase with increasing oxygen nonstoichiometry. For films cooled with an oxygen partial pressure of {le} 10{sup -4} Torr positron trapping to monovacancy type defects is inferred. For the film cooled in 10{sup -5} torr oxygen the magnitude of the increase in S, with respect to that measured from the film cooled in 760 Torr oxygen, showed positron trapping to vacancy cluster defects was occurring.

  19. Removal of lead ions from aqueous solution by the dried aquatic plant, Lemna perpusilla Torr.

    PubMed

    Tang, Yankui; Chen, Ling; Wei, Xingren; Yao, Qiuyan; Li, Ting

    2013-01-15

    The aquatic plant, Lemna perpusilla Torr. strain, was dried, pulverized and used for Pb(II) removal from aqueous solution. Batch experiments were conducted to investigate the effects of pH, contact time, initial metal concentration and temperature on Pb(II) adsorption. A dose of 4 g L(-1) of dried L. perpusilla in a solution with an initial pH of 4.6, an initial Pb(II) concentration of 50 mg L(-1) and a contact time of 210 min resulted in the maximum Pb(II) removal efficiency (above 95%). The equilibrium adsorption capacities increased with increasing initial Pb(II) concentration. The adsorption isotherm was better described by a Langmuir model rather than a Freundlich model. Further, the adsorption kinetics followed a pseudo-second-order model. An FTIR examination revealed changes between the natural and Pb(II)-loaded plant material. Scanning electron micrograph (SEM) also revealed changes in the surface morphology of the biomass as a result of lead adsorption. Based on these results, it can be concluded that the dried L. perpusilla is effective in removing lead from aqueous solution and merits consideration for scaled-up trials.

  20. Evaluating ecosystem-based management options: Effects of trawling in Torres Strait, Australia

    NASA Astrophysics Data System (ADS)

    Ellis, Nick; Pantus, Francis; Welna, Andrzej; Butler, Alan

    2008-09-01

    A suite of management options for a prawn trawl fishery in Torres Strait, Australia was assessed for impacts on the benthic fauna using a dynamic management strategy evaluation approach. The specification of the management options was gained through consultation with stakeholders. Data for the model was drawn from several sources: the fleet data from fishery logbooks and satellite vessel monitoring systems, benthic depletion rates from trawl-down experiments, benthic recovery rates from post-experiment recovery monitoring studies, and benthic distribution from large-scale benthic surveys. Although there were large uncertainties in the resulting indicators, robust measures relevant to management were obtained by taking ratios relative to the status quo. The management control with the biggest effect was total effort; reducing trawl effort always led to increases in benthic faunal density of up to 10%. Spatial closures had a smaller benefit of up to 2%. The effect of closing a set of buffer zones around reefs to trawling was indistinguishable from the status quo option. Closing a larger area, however, was largely beneficial especially for sea cucumbers. When the spatial distributions of fauna prior to fishing were accounted for, fauna with distributions positively correlated with effort improved relative to those negatively correlated. The reduction in prawn catch under effort reduction scenarios could be ameliorated by introducing temporal closures over the full-moon period.

  1. Photosynthetic Rates of Sun versus Shade Leaves of Hyptis emoryi Torr. 1

    PubMed Central

    Nobel, Park S.

    1976-01-01

    Leaves on a bush of Hyptis emoryi Torr. varied in length from less than 1 cm when development occurred in full sunlight (e.g. 40 Mjoules m−2) to over 7 cm when the total daily solar irradiance was less than 3 Mjoules m−2. The 1-cm sun leaves were 3-fold higher than the 7-cm shade leaves in chlorophyll per unit area, mesophyll thickness, and the internal to external leaf area ratio (Ames/A). The higher Ames/A caused a 1.2-cm leaf to have a 3-fold lower CO2 liquid phase resistance than did a 7.1-cm leaf. Large thin shade leaves captured photosynthetically active radiation effectively (less than 7% passed through), but were not adapted to full sunlight. Specifically, when a 6.9-cm leaf was placed at 910 w m−2 for 30 min, its temperature exceeded that of the air by nearly 8 C. For the common daytime air temperatures above 30 C for this desert shrub, large shade leaves would have temperatures far in excess of that optimum for photosynthesis for H. emoryi, 29 to 32 C. PMID:16659651

  2. Screening for Muir-Torre syndrome using mismatch repair protein immunohistochemistry of sebaceous neoplasms.

    PubMed

    Roberts, Maegan E; Riegert-Johnson, Douglas L; Thomas, Brittany C; Thomas, Colleen S; Heckman, Michael G; Krishna, Murli; DiCaudo, David J; Bridges, Alina G; Hunt, Katherine S; Rumilla, Kandelaria M; Cappel, Mark A

    2013-06-01

    Screening for the Muir-Torre variant of Lynch Syndrome (LS) using Mismatch Repair (MMR) gene immunohistochemistry (IHC) on sebaceous neoplasms (SNs) is technically feasible. To date, research into the clinical utility of MMR IHC for this indication is limited. We conducted a retrospective chart review of 90 patients with MMR IHC completed on at least one SN from January 2005 to May 2010. SNs included were adenomas, epitheliomas, carcinomas and basal and squamous cell carcinomas with sebaceous differentiation. Of the 90 patients, 13 (14 %) had genetically confirmed or fulfilled clinical criteria for a diagnosis of MTS and 51 patients (57 %) presented with an abnormal MMR IHC result (loss of one or more MMR proteins) on at least one SN. Abnormal IHC had a sensitivity of 85 %, specificity of 48 %, positive predictive value (PPV) of 22 % and negative predictive value (NPV) of 95 % when evaluating for MTS. When personal or family history of colorectal cancer (≥2 family members with a history of colorectal cancer) was taken into consideration, ignoring IHC results, sensitivity was 92 %, specificity was 99 %, PPV was 92 % and NPV was 99 %. MMR IHC on SNs when used to screen for MTS has poor diagnostic utility. We recommend that MMR IHC not be performed routinely on SNs when the patient does not have either personal or family history of colorectal cancer.

  3. Childhood disability in Aboriginal and Torres Strait Islander peoples: a literature review

    PubMed Central

    2013-01-01

    Introduction Aboriginal and Torres Strait Islander children have higher rates of disability than non-Indigenous children and are considered doubly disadvantaged, yet there is very little data reflecting prevalence and service access to inform design and delivery of services. Failing to address physical, social, and psychological factors can have life-long consequences and perpetuate longstanding health disparities. Methods A narrative literature review was undertaken to identify peer reviewed literature describing factors impacting on the prevention, recognition, and access to support and management of disability in Indigenous Australian children. Results Twenty-seven peer-reviewed journal articles met inclusion criteria. The majority of articles focused on the hearing loss and learning disabilities consequent of otitis media. Few articles reported data on urban or metropolitan Indigenous populations or described interventions. Individual/community-, provider-, and systems level factors were identified as impacting on recognition and management of disability in young Indigenous children. Conclusions Given the burden of childhood disability, the limited literature retrieved is concerning as this is a barometer of activity and investment. Solutions addressing childhood disability will require collaboration between health, social and educational disciplines as well as an increased investment in prevention, identification and promotion of access. PMID:23327694

  4. Pathological findings in wild harvested dugongs Dugong dugon of central Torres Strait, Australia.

    PubMed

    Woolford, L; Franklin, C; Whap, T; Loban, F; Lanyon, J M

    2015-03-09

    The dugong Dugong dugon is classified as Vulnerable to extinction but may be endangered in some regions. Cause of death in stranded dugongs has not been determined in a large proportion of animals examined, with investigations hindered by limited information on dugong health and diseases, and paucity of knowledge of common or endemic pathological findings. Here we describe pathological findings in harvested dugongs from the relatively pristine area of central Torres Strait, and we characterise lesions attributable to drowning. Other recorded lesions were mild and predominated by host reaction to the presence of trematodes within the gastrointestinal tracts, liver and pancreas. Ascarid worm burdens were low in comparison to dugongs from developed coastlines. Hepatocellular lipofuscin and ferritin pigmentation were commonly observed, more pronounced in livers of older animals and concurrent with periportal and bridging fibrosis. Lesions attributable to drowning included incomplete collapse of lungs, dorsal or diffuse pulmonary congestion, mild intra-alveolar haemorrhage and oedema, mild interstitial oedema and rupture of peripheral alveolar septae with acute myofibre fragmentation and degeneration. No accumulation of foam or aspiration of water or particulate matter was observed, suggesting that dugongs 'dry drown'. Morphometric features of normal spleen are also presented. Characterisation of common pathological findings and those attributable to drowning in this species will aid in the interpretation of post mortem findings for the significant number of dugongs found deceased along urbanised coastlines.

  5. DNA-based identifications reveal multiple introductions of the vegetable leafminer Liriomyza sativae (Diptera: Agromyzidae) into the Torres Strait Islands and Papua New Guinea.

    PubMed

    Blacket, M J; Rice, A D; Semeraro, L; Malipatil, M B

    2015-10-01

    Leafmining flies (Diptera: Agromyzidae) can be serious economic pests of horticultural crops. Some genera such as Liriomyza are particularly problematic with numerous species, some of which are highly polyphagous (wide host range), which can only be confidently identified morphologically from adult males. In our study, DNA barcoding was employed to establish new locality records of the vegetable leafminer fly, Liriomyza sativae, from the islands of Torres Strait (Queensland, Australia) and the central highlands of Papua New Guinea (PNG). These records represent significant range extensions of this highly invasive plant pest. Specimens of immature leafminers (from leaf mines) were collected over a 5-year period during routine plant health surveys in ethanol or on FTA® filter paper cards, both methods proved effective at preserving and transporting insect DNA under tropical conditions, with FTA cards possessing some additional logistical benefits. Specimens were identified through sequencing two sections of the cytochrome oxidase I gene and the utility of each was assessed for the identification of species and intra-specific genetic lineages. Our study indicates that multiple haplotypes of L. sativae occur in PNG, while a different haplotype is present in the Torres Strait, with genetic regionalization between these areas apart from a single possible instance - one haplotype 'S.7' appears to be common between these two regions - interestingly this has also been the most common haplotype detected in previous studies of invasive L. sativae populations. The DNA barcoding methods employed here not only identified multiple introductions of L. sativae, but also appear generally applicable to the identification of other agromyzid leafminers (Phytomyzinae and Agromyzinae) and should decrease the likelihood of potentially co-amplifying internal hymenopteran parasitoids. Currently, L. sativae is still not recorded from the Australian mainland; however, further sampling of

  6. Simulation of a non-equilibrium helium plasma bullet emerging into oxygen at high pressure (250-760 Torr) and interacting with a substrate

    NASA Astrophysics Data System (ADS)

    Yan, Wen; Economou, Demetre J.

    2016-09-01

    A two-dimensional computational study of a plasma bullet emanating from a helium gas jet in oxygen ambient at high pressure (250-760 Torr) was performed, with emphasis on the bullet interaction with a substrate. Power was applied in the form of a trapezoidal +5 kV pulse lasting 150 ns. A neutral gas transport model was employed to predict the concentration distributions of helium and oxygen in the system. These were then used in a plasma dynamics model to investigate the characteristics of the plasma bullet during its propagation and interaction with a substrate. Upon ignition, the discharge first propagated as a surface wave along the inner wall of the containing tube, and then exited the tube with a well-defined ionization front (streamer or plasma bullet). The plasma bullet evolved from a hollow (donut-shaped) feature to one where the maximum of ionization was on axis. The bullet propagated in the gap between the tube exit and the substrate with an average speed of ˜2 × 105 m/s. Upon encountering a metal substrate, the bullet formed a conductive channel to the substrate. Upon encountering a dielectric substrate, the bullet turned into an ionization wave propagating radially along the substrate surface. For a conductive substrate, the radial species fluxes to the surface peaked on the symmetry axis. For a dielectric substrate, a ring-shaped flux distribution was observed. The "footprint" of plasma-surface interaction increased either by decreasing the gap between tube exit and substrate, decreasing the relative permittivity of an insulating substrate, or decreasing pressure. As the system pressure was lowered from 760 to 250 Torr, the discharge was initiated earlier, and the plasma bullet propagation speed increased. A reverse electric field developed during the late stages of the ramp-down of the pulse, which accelerated electrons forming a brief backward discharge.

  7. Making tuba in the Torres Strait Islands: the cultural diffusion and geographic mobility of an alcoholic drink.

    PubMed

    Brady, Maggie; McGrath, Vic

    2010-01-01

    There is relatively scant evidence of the Indigenous production and consumption of intoxicating drinks on the Australian mainland prior to the arrival of outsiders. Although Australian Aboriginal peoples had mastered fermentation in some regions, the Indigenous manufacture of much stronger drinks by distillation was unknown on the Australian mainland. However, following contact with Pacific Island and Southeast Asian peoples in the 19th century, Islanders in the Torres Strait adopted techniques for fermenting and distilling what became a quasi-indigenous alcoholic drink known as tuba. This paper discusses the historical process of the diffusion of this substance as a result of labour migration and internationalisation in the Strait, and provides present-day accounts of tuba production from Torres Strait Islanders.

  8. La meridiana di Egnazio Danti nella Torre dei Venti in Vaticano: un'icona della riforma Gregoriana del calendario

    NASA Astrophysics Data System (ADS)

    Sigismondi, Costantino

    2014-05-01

    La Torre dei Venti domina l’angolo Sud Ovest del cortile della Pigna (nell'area dei Musei Vaticani), ed è inclusa negli ambienti dell'Archivio Segreto Vaticano. Non è aperta al pubblico, ma è universalmente nota per la fama che da oltre quattrocento anni la circonda, legata alle vicende della riforma Gregoriana del calendario. La meridiana tracciata da padre Egnazio Danti (1536-1586) nella torre dei Venti, fu visitata anche da Gregorio XIII, probabilmente il 21 marzo 1581 come suppone il padre Stein, per convincersi dell'anticipo ormai arrivato a dieci giorni dell'equinozio di primavera sulla data che il concilio di Nicea aveva fissato al 21 marzo per il computo pasquale. La ricognizione astrometrica del febbraio-marzo 2009 fatta dall'autore viene qui presentata.

  9. Prevalence of Hepatitis C Among Australian Aboriginal and Torres Strait Islander people: A Systematic Review and Meta-Analysis

    PubMed Central

    Graham, Simon; Harrod, Mary-Ellen; Iversen, Jenny; Simone Hocking, Jane

    2016-01-01

    Context Aboriginal and Torres Strait Islanders (Aboriginal) account for approximately 3% of the Australian population. They have the poorest health, economic and social outcomes. Higher notification rates of hepatitis C antibodies (anti-HCV) have been reported among Aboriginal compared with non-Aboriginal people. The identification of Aboriginal people in national surveillance has some weaknesses, with only four of the eight jurisdictions included in national reporting. To address some of these limitations, we aim to estimate the pooled prevalence of anti-HCV among Aboriginal people in Australia. Evidence Acquisition We searched the databases: Pubmed, Web of Science and Informit, and the New South Wales and Northern Territory Public Health Bulletins. A study was included if it reported the number of Aboriginal people testing positive for anti-HCV and the number tested for anti-HCV. A meta-analysis by population-group was conducted if three or more studies reported a prevalence estimate. Variables included: author, year of publication, study design, study period, gender (female, male), age, population group (Aboriginal people in prison, Aboriginal people who inject drugs), number testing anti-HCV positive, number tested for anti-HCV and prevalence (%). Due to a long time period, we separated the studies estimating the prevalence anti-HCV among Aboriginal people in prison into two time periods, 1994 - 2004 and 2005 - 2012. Results Overall, 15 studies met our inclusion criteria. Among Aboriginal people in prison, the pooled prevalence of anti-HCV was 18.1% (95%CI: 6.6 - 29.7). The pooled prevalence among Aboriginal people in prison was 25.7% (95%CI: 4.1-47.3) in studies published between 1994 - 2004 and 14.5% (95%CI: 1.7 - 27.3) in studies published from 2005 - 2012. The pooled prevalence of anti-HCV was 58.7% (95%CI: 53.9 - 63.5) among Aboriginal people who inject drugs and 2.9% (95%CI: 0.30 - 6.1) among Aboriginal people who did not inject drugs, however there was

  10. A Review of Programs That Targeted Environmental Determinants of Aboriginal and Torres Strait Islander Health

    PubMed Central

    Johnston, Leah; Doyle, Joyce; Morgan, Bec; Atkinson-Briggs, Sharon; Firebrace, Bradley; Marika, Mayatili; Reilly, Rachel; Cargo, Margaret; Riley, Therese; Rowley, Kevin

    2013-01-01

    Objective: Effective interventions to improve population and individual health require environmental change as well as strategies that target individual behaviours and clinical factors. This is the basis of implementing an ecological approach to health programs and health promotion. For Aboriginal People and Torres Strait Islanders, colonisation has made the physical and social environment particularly detrimental for health. Methods and Results: We conducted a literature review to identify Aboriginal health interventions that targeted environmental determinants of health, identifying 21 different health programs. Program activities that targeted environmental determinants of health included: Caring for Country; changes to food supply and/or policy; infrastructure for physical activity; housing construction and maintenance; anti-smoking policies; increased workforce capacity; continuous quality improvement of clinical systems; petrol substitution; and income management. Targets were categorised according to Miller’s Living Systems Theory. Researchers using an Indigenous community based perspective more often identified interpersonal and community-level targets than were identified using a Western academic perspective. Conclusions: Although there are relatively few papers describing interventions that target environmental determinants of health, many of these addressed such determinants at multiple levels, consistent to some degree with an ecological approach. Interpretation of program targets sometimes differed between academic and community-based perspectives, and was limited by the type of data reported in the journal articles, highlighting the need for local Indigenous knowledge for accurate program evaluation. Implications: While an ecological approach to Indigenous health is increasingly evident in the health research literature, the design and evaluation of such programs requires a wide breadth of expertise, including local Indigenous knowledge. PMID

  11. The ideas of Frantz Fanon and culturally safe practices for aboriginal and Torres Strait Islander people in Australia.

    PubMed

    Molloy, Luke; Grootjans, John

    2014-03-01

    Mainstream mental health services in Australia have failed to provide culturally appropriate care for Aboriginal and Torres Strait Islander people despite several national reports and policies that have attempted to promote positive service development in response to the calls for change from the Aboriginal and Torres Strait Islander communities. In light of this situation, this article considers the ideas of Frantz Fanon and their potential for promoting cultural safety (Ramsden, 2002) in mainstream mental health services. This article argues that Fanon's ideas provide a conceptual strategy for nurses that prompts reflection and establishes a critical theoretical perspective linking power imbalance and inequitable social relationships in health care, thus complementing the aims of cultural safety. The purpose of this critical reflection is to guide nurses' understanding of the relationship between colonization and health status in order to change their attitudes from those that continue to support current hegemonic practices and systems of health care to those that support the health of Aboriginal and Torres Strait Islander people.

  12. Bedform facies in western Torres Strait and the influence of hydrodynamics, coastal geometry, and sediment supply on their distribution

    NASA Astrophysics Data System (ADS)

    Daniell, James J.

    2015-04-01

    This study uses outputs from hydrodynamic and bedload transport models combined with satellite imagery, aerial photography, and bathymetric data to understand the distributions and mechanisms maintaining six spatially extensive bedform facies in western Torres Strait. Changes in bedform morphology occur along north-south variations in coastal geometry and east-west variations in hydrodynamic regime. Numerous islands create an environment that favours the formation of banner banks in the south, while other sandbank morphologies occur on an extensive and comparatively 'flat' basement to the north. The western side of Torres Strait experiences net bedload transport that is directed to the west throughout the year and favours the formation of bedforms that prefer unidirectional bedload transport regimes (i.e. barchan-shaped sandbanks and sand ribbons). The eastern side of the strait experiences seasonal changes in the direction of net bedload transport and maintains 'S' and 'V' shaped sandbanks. Sediment availability also influences the bedform facies. Western Torres Strait experiences net westward bedload transport through the Strait. However, sandbanks (indicating high sediment availability) are found in the central shallow and high current velocity areas, while sand ribbons (indicating low sediment availability) are a distal facies on the western side of the Strait. This sequence of bedforms indicates that sediments are preferentially trapped within the central portion of the Strait and not transported further west into the Gulf of Carpentaria.

  13. Toward 10(exp 9) GPS geodesy: Vector baselines, Earth rotation and reference frames

    NASA Technical Reports Server (NTRS)

    Schutz, Bob E.

    1993-01-01

    The University of Texas Center for Space Research research efforts under NASA Grant No. NAG-1936 from 1 Jan. 1992 - 31 Dec. 1992 were in the following areas: GPS orbit accuracy assessments and efforts to improve the accuracy; analysis of global GPS data collected during the first three months of the IGS campaign, and analysis of regional data. A brief summary of each of the above activities is presented in the following.

  14. Towards 10(exp 9) GPS geodesy: Vector baselines, Earth rotation and reference frames

    NASA Technical Reports Server (NTRS)

    Schutz, Bob E.

    1994-01-01

    Effort during the period form January 1, 1993 to December 31, 1993 were in the following areas: GPS orbit accuracy assessments and efforts to improve the accuracy; analysis and effects of GPS receiver antenna phase center variation; analysis of global GPS data being collected for the IGS campaign; and analysis of regional (south west Pacific) campaign data. A brief summary of each of the above activities is presented.

  15. Friction, Wear, and Evaporation Rates of Various Materials in Vacuum to 10(exp -7) mm Hg

    NASA Technical Reports Server (NTRS)

    Buckley, Donald H.; Swikert, Max; Johnson, Robert L.

    1961-01-01

    The requirements for bearings and seals to operate in the environment of space dictate a new area for lubrication research. The low ambient pressures encountered in space can be expected to influence the behavior of oil, grease, and solid-film lubricants. The property of these materials most significantly affected by low ambient pressures is the evaporation rate. Various investigators have therefore measured the evaporation rates of oils and greases in vacuum as one method of establishing their relative merit for space applications (1-3). The results of this work have given some indication as to the oils and greases with the greatest stability at reduced ambient pressures. Only limited experimental work, however, has been reported in the literature for inorganic solids and soft metals which have potential use as solid lubricant films or coatings for hard alloy substrates [e.g. Reference ( 4 )]. In general, the evaporation rates of these materials would be lower than those of oils and greases. These films might therefore be very attractive as lubricants for high vacuum service.

  16. Directional Limits on Persistent Gravitational Waves Using LIGO S5 Science Data

    NASA Technical Reports Server (NTRS)

    Abadie, J.; Abbott, B. P.; Abbott, R.; Abernathy, M.; Accadia, T.; Acernese, F.; Adams, C.; Adhikari, R.; Ajith, P.; Allen, B.; Allen, G. S.; Amador Ceron, E.; Amin, R. S.; Anderson, S. B.; Anderson, W. G.; Antonucci, F.; Arain, M. A.; Araya, M. C.; Aronsson, M.; Arun, K. G.; Aso, Y.; Aston, S. M.; Astone, P.; Cannizzo, J.; Stroeer, A. S.

    2011-01-01

    The gravitational-wave (GW) sky may include nearby pointlike sources as well as astrophysical and cosmological stochastic backgrounds. Since the relative strength and angular distribution of the many possible sources of GWs are not well constrained, searches for GW signals must be performed in a model-independent way. To that end we perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. The latter result is the first of its kind. Finding no evidence to support the detection of GWs, we present 90% confidence level (CL) upper-limit maps of GW strain power with typical values between 2 - 20 X 10 (exp -50) strain2Hz(exp -1) and 5 - 35 X 10 (exp -49) strain2Hz(exp -1)/sr for pointlike and extended sources respectively. The limits on pointlike sources constitute a factor of 30 improvement over the previous best limits. We also set 90% CL limits on the narrow-band root-mean-square GW strain from interesting targets including Sco X-1, SN1987A and the Galactic Center as low as approximately equal 7 X 10(exp -25) in the most sensitive frequency range near 160Hz. These limits are the most constraining to date and constitute a factor of 5 improvement over the previous best limits.

  17. Observations of 13.5 micron rotation-vibration lines of SiS in IRC +10216

    NASA Technical Reports Server (NTRS)

    Boyle, R. J.; Keady, J. J.; Jennings, D. E.; Hirsch, K. L.; Wiedemann, G. R.

    1994-01-01

    We report the first observations of the 13.5 micron fundamental band of SiS in the spectrum of the heavily obscured carbon star IRC +10216. The lines are formed in the inner region of the circumstellar envelope where the gas is accerlerating and where the temperature ranges from 800-500 K. We have carried out a detailed model of the observed line profiles. Our observations are best fit by a gradient in the abundance of SiS. We derive an abundance relative to molecular hydrogen of x(SiS) = 4.3 x 10(exp -6) at a distance of twelve stellar radii from the central star rising to x(SiS) = 4.3 x 10(exp -5) at a few stellar radii from the surface of the star.

  18. Spatially controlled Fe and Si isotope variations: an alternative view on the formation of the Torres del Paine pluton

    NASA Astrophysics Data System (ADS)

    Gajos, Norbert A.; Lundstrom, Craig C.; Taylor, Alexander H.

    2016-11-01

    We present new Fe and Si isotope ratio data for the Torres del Paine igneous complex in southern Chile. The multi-composition pluton consists of an approximately 1 km vertical exposure of homogenous granite overlying a contemporaneous 250-m-thick mafic gabbro suite. This first-of-its-kind spatially dependent Fe and Si isotope investigation of a convergent margin-related pluton aims to understand the nature of granite and silicic igneous rock formation. Results collected by MC-ICP-MS show a trend of increasing δ56Fe and δ30Si with increasing silica content as well as a systematic increase in δ56Fe away from the mafic base of the pluton. The marginal Torres del Paine granites have heavier Fe isotope signatures (δ56Fe = +0.25 ± 0.02 2se) compared to granites found in the interior pluton (δ56Fe = +0.17 ± 0.02 2se). Cerro Toro country rock values are isotopically light in both Fe and Si isotopic systems (δ56Fe = +0.05 ± 0.02 ‰; δ30Si = -0.38 ± 0.07 ‰). The variations in the Fe and Si isotopic data cannot be accounted for by local assimilation of the wall rocks, in situ fractional crystallization, late-stage fluid exsolution or some combination of these processes. Instead, we conclude that thermal diffusion or source magma variation is the most likely process producing Fe isotope ratio variations in the Torres del Paine pluton.

  19. Vicariance and dispersal across an intermittent barrier: population genetic structure of marine animals across the Torres Strait land bridge

    NASA Astrophysics Data System (ADS)

    Mirams, A. G. K.; Treml, E. A.; Shields, J. L.; Liggins, L.; Riginos, C.

    2011-12-01

    Biogeographic barriers, some transitory in duration, are likely to have been important contributing factors to modern marine biodiversity in the Indo-Pacific region. One such barrier was the Torres Strait land bridge between continental Australia and New Guinea that persisted through much of the late Pleistocene and separated Indian and Pacific Ocean taxa. Here, we examine the patterns of mitochondrial DNA diversity for marine animals with present-day distributions spanning the Torres Strait. Specifically, we investigate whether there are concordant signatures across species, consistent with either vicariance or recent colonization from either ocean basin. We survey four species of reef fishes ( Apogon doederleini, Pomacentrus coelestis, Dascyllus trimaculatus, and Acanthurus triostegus) for mtDNA cytochrome oxidase 1 and control region variation and contrast these results to previous mtDNA studies in diverse marine animals with similar distributions. We find substantial genetic partitioning (estimated from F-statistics and coalescent approaches) between Indian and Pacific Ocean populations for many species, consistent with regional persistence through the late Pleistocene in both ocean basins. The species-specific estimates of genetic divergence, however, vary greatly and for reef fishes we estimate substantially different divergence times among species. It is likely that Indian and Pacific Ocean populations have been isolated for multiple glacial cycles for some species, whereas for other species genetic connections have been more recent. Regional estimates of genetic diversity and directionality of gene flow also vary among species. Thus, there is no apparent consistency among historical patterns across the Torres Strait for these co-distributed marine animals.

  20. Translating E-Mental Health Into Practice: What Are the Barriers and Enablers to E-Mental Health Implementation by Aboriginal and Torres Strait Islander Health Professionals?

    PubMed Central

    Singer, Judy; DuBois, Simon; Hyde, Kelly

    2017-01-01

    Background With increasing evidence for the effectiveness of e-mental health interventions for enhancing mental health and well-being, a growing challenge is how to translate promising research findings into service delivery contexts. A 2012 e-mental health initiative by the Australian Federal Government (eMHPrac) has sought to address the issue through several strategies, one of which has been to train different health professional workforces in e-mental health (e-MH). Objective The aim of the study was to report on the barriers and enablers of e-MH uptake in a cohort of predominantly Aboriginal and Torres Strait Islander health professionals (21 Indigenous, 5 non-Indigenous) who occupied mainly support or case management roles within their organizations. Methods A 3- or 2-day e-MH training program was followed by up to 5 consultation sessions (mean 2.4 sessions) provided by the 2 trainers. The trainer-consultants provided written reports on each of the 30 consultation sessions for 7 consultation groups. They were also interviewed as part of the study. The written reports and interview data were thematically analyzed by 2 members of the research team. Results Uptake of e-MH among the consultation group was moderate (22%-30% of participants). There were significant organizational barriers to uptake resulting from procedural and administrative problems, demanding workloads, prohibitive policies, and a lack of fit between the organizational culture and the introduction of new technologies. Personal barriers included participant beliefs about the applicability of e-MH to certain populations, and workers’ lack of confidence and skills. However, enthusiastic managers and tech-savvy champions could provide a counter-balance as organizational enablers of e-MH; and the consultation sessions themselves appear to have enhanced skills and confidence, shifted attitudes to new technologies, and seeded a perception that e-MH could be a valuable health education resource

  1. Association of Arsenic and Metals with Concentrations of 25-Hydroxyvitamin D and 1,25-Dihydroxyvitamin D among Adolescents in Torreón, Mexico

    PubMed Central

    Zamoiski, Rachel D.; Guallar, Eliseo; García-Vargas, Gonzalo G.; Rothenberg, Stephen J.; Resnick, Carol; Andrade, Marisela Rubio; Steuerwald, Amy J.; Parsons, Patrick J.; Weaver, Virginia M.; Navas-Acien, Ana

    2014-01-01

    Background: Limited data suggest that lead (Pb), cadmium (Cd), and uranium (U) may disrupt vitamin D metabolism and inhibit production of 1,25-dihydroxyvitamin D [1,25(OH)2D], the active vitamin D metabolite, from 25-hydroxyvitamin D [25(OH)D] in the kidney. Objectives: We evaluated the association between blood lead (BPb) and urine arsenic (As), Cd, molybdenum (Mo), thallium (Tl), and U with markers of vitamin D metabolism [25(OH)D and 1,25(OH)2D]. Methods: We conducted a cross-sectional study of 512 adolescents in Torreón, a town in Mexico with a Pb smelter near residential areas. BPb was measured using atomic absorption spectrometry. Urine As, Cd, Mo, Tl, and U were measured using inductively coupled plasma mass spectrometry. Serum 25(OH)D and 1,25(OH)2D were measured using a chemiluminescent immunoassay and a radioimmunoassay, respectively. Multivariable linear models with vitamin D markers as the outcome were used to estimate associations of BPb and creatinine-corrected urine As and metal concentrations with serum vitamin D concentrations, controlling for age, sex, adiposity, smoking, socioeconomic status, and time outdoors. Results: Serum 25(OH)D was positively associated with urine Mo and Tl [1.5 (95% CI: 0.4, 2.6) and 1.2 (95% CI: 0.3, 2.1) ng/mL higher with a doubling of exposure, respectively]. Serum 1,25(OH)2D was positively associated with urine As and U [3.4 (95% CI: 0.9, 5.9) and 2.2 (95% CI: 0.7, 3.7) pg/mL higher, respectively], with little change in associations after additional adjustment for serum 25(OH)D. Pb and Cd were not associated with 25(OH)D or 1,25(OH)2D concentrations. Conclusions: Overall, our findings did not support a negative effect of As or metal exposures on serum 1,25(OH)2D concentrations. Additional research is needed to confirm positive associations between serum 1,25(OH)2D and urine U and As concentrations and to clarify potential underlying mechanisms. Citation: Zamoiski RD, Guallar E, García-Vargas GG, Rothenberg SJ

  2. Trail impacts and trail impact management related to ecotourism visitation at Torres del Paine National Park, Chile

    USGS Publications Warehouse

    Farrell, T.A.; Marion, J.L.

    2002-01-01

    Ecotourism and protected area visitation in Central and South America are largely dependent upon a relatively undisturbed quality of natural resources. However, visitation may impact vegetation, soil, water and wildlife resources, and degrade visitor facilities such as recreation sites and trails. Findings are reported from trail impact research conducted at Torres del Paine National Park in Patagonia, Chile. The frequency and magnitude of selected trail impacts and the relative effect of the amount of use, vegetation type, trail position and trail grade are investigated. Findings differed from previous studies in that amount of use was significantly related to both trail width increases and trail erosion. Management actions to minimize trail impacts are offered.

  3. Spatial patterns of sub-tidal seagrasses and their tissue nutrients in the Torres Strait, northern Australia: Implications for management

    NASA Astrophysics Data System (ADS)

    Sheppard, James K.; Carter, Alex B.; McKenzie, Len J.; Pitcher, C. Roland; Coles, Robert G.

    2008-09-01

    The distribution and nutritional profiles of sub-tidal seagrasses from the Torres Strait were surveyed and mapped across an area of 31,000 km 2. Benthic sediment composition, water depth, seagrass species type and nutrients were sampled at 168 points selected in a stratified representative pattern. Eleven species of seagrass were present at 56 (33.3%) of the sample points. Halophila spinulosa, Halophila ovalis, Cymodocea serrulata and Syringodium isoetifolium were the most common species and these were nutrient profiled. Sub-tidal seagrass distribution (and associated seagrass nutrient concentrations) was generally confined to northern-central and south-western regions of the survey area (Torres Strait. There were two regions in Torres Strait (north-central and south-western) where sub-tidal seagrass meadows were prevalent and of relatively higher

  4. Reducing SS 304/316 hydrogen outgassing to 2x10{sup -15} torr l/cm{sup 2} s

    SciTech Connect

    Sasaki, Y. Tito

    2007-07-15

    Significant reduction in the outgassing rate of 300-series stainless steel is routinely attained through combination of electropolishing and vacuum baking. Preferential removal of Ni, Fe, and Mn from the surface of stainless steel by electropolishing creates a chromium-enriched surface. It also reduces the atomic surface area of the work piece closer to its geometric surface area. When the material is vacuum fired to remove interstitial hydrogen, the resultant stainless steel exhibits an outgassing rate of about 2x10{sup -15} torr l/cm{sup 2} s, as well as drastically reduced adsorption, absorption, and catalytic behaviors.

  5. Rapid Rejuvenation of the Source of a Backarc Sheeted Magmatic Complex (Torres del Paine, Patagonia): Evidence From Hf isotopes in Zircon

    NASA Astrophysics Data System (ADS)

    Ewing, T. A.; Muntener, O.; Leuthold, J.; Chiaradia, M.; Baumgartner, L. P.; Putlitz, B.

    2014-12-01

    The Miocene Torres del Paine intrusive complex (TPIC) in Patagonia is a spectacularly exposed example of a bimodal shallow crustal laccolith, made up of a sill complex and a subvertical feeder system. The TPIC was emplaced in a back-arc setting, but slightly older arc-related intrusive units in this area testify to an earlier shift from an arc to a backarc setting. The entire ~88 km3 main complex was emplaced over short time scales of 162 ± 11 ka between ~12.4 and 12.6 Ma, with mafic units from the feeder zone found to be older than mafic units from the sill complex1,2. We aim to assess whether successive pulses of mafic magmatism can tap different geochemical reservoirs in sheeted magmatic complexes emplaced on such short timescales. Hf isotope compositions of individual zircons from mafic units from both the feeder zone and the sill complex were determined by solution MC-ICPMS. Zircons from all units have Hf isotope compositions that indicate a slightly enriched mantle source. Zircons from the mafic sill complex units have higher (more juvenile) initial ɛHf than zircons from feeder zone mafic units. The shift towards more depleted Hf isotope compositions in the sill complex units, which are younger, demonstrates the rapid input of new juvenile material into the source region between ~12.6 Ma and ~12.5 Ma. A similar shift is also seen in bulk rock Nd and Sr isotope data for related samples3. The Hf isotope data demonstrate that significant variability in source geochemistry is possible for sheeted magmatic complexes built up on very short timescales. Analysis of zircons from a range of dikes and intrusive bodies external to the main Torres del Paine complex, with ages that span ~12-29 Ma, will provide a more complete picture in time and space of the geochemical evolution of this magmatic system as it switches between an arc and backarc setting. 1Leuthold et al., 2012, EPSL, 325: 85-92 2Michel et al., 2008, Geology, 36: 459-462 3Leuthold et al., 2013, JPET, 54

  6. Radiation hardness of Ga0.5In0.5 P/GaAs tandem solar cells

    NASA Technical Reports Server (NTRS)

    Kurtz, Sarah R.; Olson, J. M.; Bertness, K. A.; Friedman, D. J.; Kibbler, A.; Cavicchi, B. T.; Krut, D. D.

    1991-01-01

    The radiation hardness of a two-junction monolithic Ga sub 0.5 In sub 0.5 P/GaAs cell with tunnel junction interconnect was investigated. Related single junction cells were also studied to identify the origins of the radiation losses. The optimal design of the cell is discussed. The air mass efficiency of an optimized tandem cell after irradiation with 10(exp 15) cm (-2) 1 MeV electrons is estimated to be 20 percent using currently available technology.

  7. Comparing the role of absolute sea-level rise and vertical tectonic motions in coastal flooding, Torres Islands (Vanuatu)

    NASA Astrophysics Data System (ADS)

    Ballu, Valérie; Bouin, Marie-Noëlle; Siméoni, Patricia; Crawford, Wayne C.; Calmant, Stephane; Boré, Jean-Michel; Kanas, Tony; Pelletier, Bernard

    2011-08-01

    Since the late 1990s, rising sea levels around the Torres Islands (north Vanuatu, southwest Pacific) have caused strong local and international concern. In 2002-2004, a village was displaced due to increasing sea incursions, and in 2005 a United Nations Environment Programme press release referred to the displaced village as perhaps the world's first climate change "refugees." We show here that vertical motions of the Torres Islands themselves dominate the apparent sea-level rise observed on the islands. From 1997 to 2009, the absolute sea level rose by 150 + /-20 mm. But GPS data reveal that the islands subsided by 117 + /-30 mm over the same time period, almost doubling the apparent gradual sea-level rise. Moreover, large earthquakes that occurred just before and after this period caused several hundreds of mm of sudden vertical motion, generating larger apparent sea-level changes than those observed during the entire intervening period. Our results show that vertical ground motions must be accounted for when evaluating sea-level change hazards in active tectonic regions. These data are needed to help communities and governments understand environmental changes and make the best decisions for their future.

  8. Comparing the role of absolute sea-level rise and vertical tectonic motions in coastal flooding, Torres Islands (Vanuatu).

    PubMed

    Ballu, Valérie; Bouin, Marie-Noëlle; Siméoni, Patricia; Crawford, Wayne C; Calmant, Stephane; Boré, Jean-Michel; Kanas, Tony; Pelletier, Bernard

    2011-08-09

    Since the late 1990s, rising sea levels around the Torres Islands (north Vanuatu, southwest Pacific) have caused strong local and international concern. In 2002-2004, a village was displaced due to increasing sea incursions, and in 2005 a United Nations Environment Programme press release referred to the displaced village as perhaps the world's first climate change "refugees." We show here that vertical motions of the Torres Islands themselves dominate the apparent sea-level rise observed on the islands. From 1997 to 2009, the absolute sea level rose by 150 + /-20 mm. But GPS data reveal that the islands subsided by 117 + /-30 mm over the same time period, almost doubling the apparent gradual sea-level rise. Moreover, large earthquakes that occurred just before and after this period caused several hundreds of mm of sudden vertical motion, generating larger apparent sea-level changes than those observed during the entire intervening period. Our results show that vertical ground motions must be accounted for when evaluating sea-level change hazards in active tectonic regions. These data are needed to help communities and governments understand environmental changes and make the best decisions for their future.

  9. Comparing the role of absolute sea-level rise and vertical tectonic motions in coastal flooding, Torres Islands (Vanuatu)

    PubMed Central

    Ballu, Valérie; Bouin, Marie-Noëlle; Siméoni, Patricia; Crawford, Wayne C.; Calmant, Stephane; Boré, Jean-Michel; Kanas, Tony; Pelletier, Bernard

    2011-01-01

    Since the late 1990s, rising sea levels around the Torres Islands (north Vanuatu, southwest Pacific) have caused strong local and international concern. In 2002–2004, a village was displaced due to increasing sea incursions, and in 2005 a United Nations Environment Programme press release referred to the displaced village as perhaps the world’s first climate change “refugees.” We show here that vertical motions of the Torres Islands themselves dominate the apparent sea-level rise observed on the islands. From 1997 to 2009, the absolute sea level rose by 150 + /-20 mm. But GPS data reveal that the islands subsided by 117 + /-30 mm over the same time period, almost doubling the apparent gradual sea-level rise. Moreover, large earthquakes that occurred just before and after this period caused several hundreds of mm of sudden vertical motion, generating larger apparent sea-level changes than those observed during the entire intervening period. Our results show that vertical ground motions must be accounted for when evaluating sea-level change hazards in active tectonic regions. These data are needed to help communities and governments understand environmental changes and make the best decisions for their future. PMID:21795605

  10. Angle-resolved environmental X-ray photoelectron spectroscopy: A new laboratory setup for photoemission studies at pressures up to 0.4 Torr

    NASA Astrophysics Data System (ADS)

    Mangolini, F.; Åhlund, J.; Wabiszewski, G. E.; Adiga, V. P.; Egberts, P.; Streller, F.; Backlund, K.; Karlsson, P. G.; Wannberg, B.; Carpick, R. W.

    2012-09-01

    The paper presents the development and demonstrates the capabilities of a new laboratory-based environmental X-ray photoelectron spectroscopy system incorporating an electrostatic lens and able to acquire spectra up to 0.4 Torr. The incorporation of a two-dimensional detector provides imaging capabilities and allows the acquisition of angle-resolved data in parallel mode over an angular range of 14° without tilting the sample. The sensitivity and energy resolution of the spectrometer have been investigated by analyzing a standard Ag foil both under high vacuum (10-8 Torr) conditions and at elevated pressures of N2 (0.4 Torr). The possibility of acquiring angle-resolved data at different pressures has been demonstrated by analyzing a silicon/silicon dioxide (Si/SiO2) sample. The collected angle-resolved spectra could be effectively used for the determination of the thickness of the native silicon oxide layer.

  11. Search for Gravitational Waves from Compact Binary Coalescence in LIGO and Virgo Data from S5 and VSR1

    NASA Technical Reports Server (NTRS)

    Abadie, J.; Abbott, B. P.; Abbott, R.; Accadia, T.; Acernese, F.; Adams, C.; Adhikari, R.; Ajith, P.; Allen, B.; Allen, G.; Ceron, E. Amador; Amin, R. S.; Anderson, S. B.; Anderson, W. G.; Antonucci, F.; Arain, M. A.; Araya, M.; Aronsson, M.; Arun, K. G.; Aso, Y.; Aston, S.; Astone, P.; Atkinson, D. E.; Camp, J. B.; Cannizzo, J.

    2010-01-01

    We report the results of the first search for gravitational waves from compact binary coalescence using data from the Laser Interferometer Gravitational-wave Observatory (LIGO) and Virgo detectors. Five months of data were collected during the concurrent S5 (UGO) and VSRI (Virgo) science runs. The search focused on signals from binary mergers with a total mass between 2 and 35 Solar Mass. No gravitational waves are identified. The cumulative 90%-confidence upper limits on the rate of compact binary coalescence are calculated for non-spinning binary neutron stars, black hole-neutron star systems, and binary black holes to be 8.7 x 10(exp -3) / yr-1/L(sub 10) 2.2 x 10-3 yr-1L101, and 4.4 x 10(exp -4)3) / yr-1/L(sub 10) respectively, where L (sub 10) is 10(exp 10) times the blue solar luminosity. These upper limits are compared with astrophysical expectations.

  12. Epidemiology, etiology, and motivation of alcohol misuse among Australian Aboriginal and Torres Strait Islanders of the Northern Territory: a descriptive review.

    PubMed

    Ramamoorthi, Ramya; Jayaraj, Rama; Notaras, Leonard; Thomas, Mahiban

    2015-01-01

    The per capita alcohol consumption of the Northern Territory, Australia, is second highest in the world, estimated 15.1 liters of pure alcohol per year. Alcohol abuse is a major public health concern among Aboriginal and Torres Strait Islander people in Australia. The Aboriginal and Torres Strait Islanders in the Northern Territory consume approximately 16.9 liters of pure alcohol per year. This descriptive review is based on current published and grey literature in the context of high risk alcohol use, with a special focus on the epidemiological, etiological, and social factors, to predict alcohol misuse among the Australian Aboriginal and Torres Strait Islanders in Northern Territory. The methodology involved a descriptive search on PubMed, Northern Territory government reports, health databases, and Web sites with an emphasis on the etiology and epidemiology of high-risk alcohol consumption among the Australian Aboriginal and Torres Strait Islanders of the Northern Territory. This review has its own limitations because it does not rely on systematic review methodologies. However, it presents real data on the motives for binge drinking and alcohol-related violent assaults of this vulnerable population. Alcohol abuse and alcohol-related harms are considerably high among the rural and remote communities where additional research is needed. High-risk alcohol misuse within Australian Aboriginal and Torres Strait Islanders communities often leads to a series of physical and social consequences. This review highlights the need for culturally appropriate intervention approaches focusing on alcohol misuse among the Aboriginal and Torres Strait Islanders population of the Northern Territory.

  13. LIBS-based detection of geological samples at low pressures (<0.001 torr) for moon and asteroid exploration.

    SciTech Connect

    Harris, R. D.; Cremers, D. A.; Khoo, C.; Benelli, K. M.

    2005-01-01

    LIBS is under development for future use on surface probes to Mars. Under simulated Mars atmospheric composition and pressure (7 torr, predominately CO{sub 2}), LIBS has been shown useful for qualitative and quantitative analysis of geological samples at close and stand-off distances (19 m). Because of its many advantages compared to previously deployed and current in-use methods of elemental analysis (e.g. x-ray fluorescence, APXS), LIBS has potential for application to other planetary bodies. Of particular interest are the Moon and asteroids having very low ambient gas pressures at the surface. Because the laser plasma used by LIBS is sensitive to the surrounding atmosphere, it is important to determine analysis capabilities under these conditions. The results of a study of LIBS capabilities at low pressure is presented here for both in-situ and stand-off analysis.

  14. Urinary excretion of cadmium among Torres Strait Islanders (Australia) at risk of elevated dietary exposure through traditional foods.

    PubMed

    Haswell-Elkins, Melissa; Imray, Paula; Satarug, Soisungwan; Moore, Michael R; O'dea, Kerin

    2007-07-01

    This study explored urinary cadmium levels among Torres Strait Islanders in response to concerns about potential health impact of high levels of cadmium in some traditional seafood (dugong and turtle liver and kidney). Cadmium levels were measured by inductively coupled mass spectrometry in de-identified urine samples collected during general screening programs in 1996 in two communities with varying dugong and turtle catch statistics. Statistical analysis was performed to identify links between cadmium levels and demographic and background health information. Geometric mean cadmium level among the sample group was 0.83 mug/g creatinine with 12% containing over 2 microg/g creatinine. Cadmium level was most strongly associated with age (46% of variation), followed by sex (females >males, 7%) and current smoking status (smokers >non-smokers, 4.7%). Adjusting model conditions suggested further positive associations between cadmium level and diabetes (p=0.05) and residence in the predicted higher exposure community (p=0.07). Positive correlations between cadmium and body fat in bivariate analysis were eliminated by control for age and sex. This study found only suggestive differences in cadmium levels between two communities with predicted variation in exposure from traditional foods. However, the data indicate that factors linked with higher cadmium accumulation overlap with those of renal disease risk (i.e. older, females, smokers, diabetes) and suggest that levels may be sufficient to contribute to renal pathology. More direct assessment of exposure and health risks of cadmium to Torres Strait Islanders is needed given the disproportionate level of diet-related disease and the cultural importance of dugong and turtle. This study highlights the need to consider social and cultural variation in exposure and to define "safe" cadmium levels during diabetes given its rising global prevalence.

  15. Fourier transform infrared studies of the interaction of HCl with model polar stratospheric cloud films

    NASA Technical Reports Server (NTRS)

    Koehler, Birgit G.; Mcneill, Laurie S.; Middlebrook, Ann M.; Tolbert, Margaret A.

    1993-01-01

    Heterogeneous reactions involving hydrochloric acid adsorbed on the surfaces of polar stratospheric clouds (PSCs) are postulated to contribute to polar ozone loss. Using FTIR spectroscopy to probe the condensed phase, we have examined the interaction of HCl with ice and nitric acid trihydrate (NAT) films representative of types II and I PSCs, respectively. For HCl pressures in the range of 10 exp -7 to 10 exp -5 Torr, our FTIR studies show that a small amount of crystalline HCl-6H2O formed on or in ice at 155 K. However, for higher HCl pressures, we observed that the entire film of ice rapidly converted into an amorphous 4:1 H2O:HCl mixture. From HCl-uptake experiments with P(HCl) = 8 x 10 exp -7 Torr, we estimate roughly that the diffusion coefficient of HCl in ice is around 2 x 10 exp -12 sq cm/s at 158 K. For higher temperatures more closely approximating those found in the stratosphere, we were unable to detect bulk HCl uptake by ice. Indirect evidence suggests that HCl adsorption onto the surface of model PSC films inhibited the evaporation of both ice and NAT by 3-5 K.

  16. Epistemological Considerations for Approaching Teaching in an On-Line Environment Aboriginal and Torres Strait Islander Teacher Education Program: Reconsidering TPACK

    ERIC Educational Resources Information Center

    Lewthwaite, Brian Ellis; Knight, Cecily; Lenoy, Max

    2015-01-01

    This research inquiry explores teacher educator knowledge, understandings and beliefs informing their teaching in a web-based Australian teacher education program for Aboriginal and Torres Strait Islander students. Through the use of a phenomenologically aligned interview process, the study investigates instructors' consideration of practice for…

  17. What's in a Name?: Exploring the Implications of Eurocentric (Re)naming Practices of Aboriginal and Torres Strait Islander Nomenclature in Australian Education Practices

    ERIC Educational Resources Information Center

    Weuffen, Sara; Cahir, Fred; Zeegers, Margaret

    2016-01-01

    The aim of this article is to provide teachers with knowledge of ways in which Eurocentric (re)naming practices inform contemporary pedagogical approaches, while providing understandings pertinent to the mandatory inclusion of the cross-curriculum priority area: "Aboriginal and Torres Strait Islander histories and cultures" (Australian…

  18. Best Practice in Aboriginal and Torres Strait Islander Education. Proceedings of the Conference (Canberra, Australian Capital Territory, Australia, November 17-18, 1993).

    ERIC Educational Resources Information Center

    Australian National Languages and Literacy Inst., Deakin.

    Papers from the conference on the education of Australian Aborigines and Torres Strait Islanders include: "English Language and Numeracy Program for Aboriginal Students" (Alison Jarred); "The Aboriginal Identity Course: A Midstream Evaluation" (Simon Vaughan); "Making the Curriculum Your Own: The Senior Girls at Lajamanu…

  19. Growth of nitric acid hydrates on thin sulfuric acid films

    NASA Technical Reports Server (NTRS)

    Iraci, Laura T.; Middlebrook, Ann M.; Wilson, Margaret A.; Tolbert, Margaret A.

    1994-01-01

    Type I polar stratospheric clouds (PSCs) are thought to nucleate and grow on stratospheric sulfate aerosols (SSAs). To model this system, thin sulfuric acid films were exposed to water and nitric acid vapors (1-3 x 10(exp -4) Torr H2O and 1-2.5 x 10(exp -6) Torr HNO3) and subjected to cooling and heating cycles. Fourier Transform Infrared (FTIR) spectroscopy was used to probe the phase of the sulfuric acid and to identify the HNO3/H2O films that condensed. Nitric acid trihydrate (NAT) was observed to grow on crystalline sulfuric acid tetrahydrate (SAT) films. NAT also condensed in/on supercooled H2SO4 films without causing crystallization of the sulfuric acid. This growth is consistent with NAT nucleation from ternary solutions as the first step in PSC formation.

  20. Middle Paleolithic human remains from the Gruta Da Oliveira (Torres Novas), Portugal.

    PubMed

    Willman, John C; Maki, Julia; Bayle, Priscilla; Trinkaus, Erik; Zilhão, João

    2012-09-01

    Additional Middle Paleolithic human remains from layers 17, 18, and 22 of the Gruta da Oliveira, Portugal consist of a proximal manual phalanx 2 (Oliveira 5), a partial postcanine tooth (Oliveira 6), a humeral diaphysis (Oliveira 7), a distal mandibular molar (Oliveira 8), and a mandibular premolar (P(3) ) (Oliveira 9). Oliveira 5, 6, and 8 are unremarkable for Late Pleistocene humans. The Oliveira 7 right humerus is moderately robust or the individual had the stocky body proportions of other European (including Iberian) Neandertals. The Oliveira 9 P(3) has a large and symmetrical crown and lacks a distal accessory ridge and accessory lingual cusps, overlapping both Neandertal and recent human ranges of variation. It contrasts with at least recent human P(3) s in having relatively thin enamel. These join the Oliveira 1 to 4 remains in further documenting early MIS 3 Neandertal morphology in western Iberia.

  1. Building better systems of care for Aboriginal and Torres Strait Islander people: findings from the Kanyini health systems assessment

    PubMed Central

    2012-01-01

    Background Australian federal and jurisdictional governments are implementing ambitious policy initiatives intended to improve health care access and outcomes for Aboriginal and Torres Strait Islander people. In this qualitative study we explored Aboriginal Medical Service (AMS) staff views on factors needed to improve chronic care systems and assessed their relevance to the new policy environment. Methods Two theories informed the study: (1) ‘candidacy’, which explores “the ways in which people’s eligibility for care is jointly negotiated between individuals and health services”; and (2) kanyini or ‘holding’, a Central Australian philosophy which describes the principle and obligations of nurturing and protecting others. A structured health systems assessment, locally adapted from Chronic Care Model domains, was administered via group interviews with 37 health staff in six AMSs and one government Indigenous-led health service. Data were thematically analysed. Results Staff emphasised AMS health care was different to private general practices. Consistent with kanyini, community governance and leadership, community representation among staff, and commitment to community development were important organisational features to retain and nurture both staff and patients. This was undermined, however, by constant fear of government funding for AMSs being withheld. Staff resourcing, information systems and high-level leadership were perceived to be key drivers of health care quality. On-site specialist services, managed by AMS staff, were considered an enabling strategy to increase specialist access. Candidacy theory suggests the above factors influence whether a service is ‘tractable’ and ‘navigable’ to its users. Staff also described entrenched patient discrimination in hospitals and the need to expend considerable effort to reinstate care. This suggests that Aboriginal and Torres Strait Islander people are still constructed as ‘non-ideal users

  2. Entomological and ecological studies in a new potential zoonotic leishmaniasis focus in Torres Novas municipality, Central Region, Portugal.

    PubMed

    Branco, S; Alves-Pires, C; Maia, C; Cortes, S; Cristovão, J M S; Gonçalves, L; Campino, L; Afonso, M O

    2013-03-01

    In Portugal human and canine leishmaniasis are caused by Leishmania infantum, and Phlebotomus perniciosus and P. ariasi are the proven vectors. Three main foci were identified in eighty's decade: Trás-os-Montes and Alto Douro region, Lisbon region and Algarve region, but according to OnLeish observatory data, canine leishmaniasis cases have been reported from several other regions, for which sand fly species and their infection rates are unknown. This study is the first phlebotomine survey in Torres Novas municipality, Santarém District, Portugal. The main objectives were to identify the phlebotomine species, their bioecological aspects, Leishmania infection rate and the risk factors for the presence of phlebotomine species in the municipality. From June to November, 2010, 275 biotopes were surveyed with CDC light-traps. Captures covered the 17 parishes of the municipality and included domestic, peridomestic and sylvatic biotopes. Specimens were identified morphologically and females were used for molecular detection of Leishmania and bloodmeal identification. Simple and multiple logistic regression analysis were used to identify risk factors for phlebotomine presence. Nonparametric tests were used to compare densities of independent groups. A total of 1262 sand flies were captured and identified, and four species detected: P. perniciosus (73.69%), P. ariasi (8.16%), P. sergenti (6.58%) and Sergentomyia minuta (11.57%). In 71.4% localities at least one L. infantum proven vector species was present. Risk factors were identified as: high average temperatures and low relative humidities, sheltered locations and absence of strong wind, presence of pine trees as dominant vegetation, peridomestic biotopes, particularly sheep pens or proximity of sheep, poultry and house martin nests. L. infantum infection rate was 4% for P. ariasi and 0.48% for the total of Larroussius females. P. perniciosus females exhibited an opportunistic behavior, feeding in a wide variety of

  3. Middle Paleolithic human remains from the Gruta da Oliveira (Torres Novas), Portugal.

    PubMed

    Trinkaus, Erik; Maki, Julia; Zilhão, João

    2007-10-01

    Ongoing excavations in the Middle Paleolithic levels at the Gruta da Oliveira, Portugal have yielded four fragmentary human remains, a manual phalanx and an ulna from levels 9 and 10, and a humerus and a tibia from levels 18 and 19. The first two remains date to approximately 39 ka 14C BP ( approximately 43.5 ka cal BP), whereas the latter two derive from earlier in oxygen isotope stage 3. The preserved portions of the phalanx, humerus, and tibia align them morphologically with the Neandertals. In addition, the Oliveira 4 tibial diaphysis shows evidence of carnivore (probably canid) gnawing.

  4. VizieR Online Data Catalog: Photometry and spectroscopy of V501 Mon (Torres+, 2015)

    NASA Astrophysics Data System (ADS)

    Torres, G.; Lacy, C. H. S.; Pavlovski, K.; Fekel, F. C.; Muterspaugh, M. W.

    2016-06-01

    Spectroscopic observations of V501 Mon were carried out with three different instruments. They began at the Harvard-Smithsonian Center for Astrophysics (CfA) in 2005 November, using the now decommissioned Digital Speedometer (DS) mounted on the 1.5m Tillinghast reflector at the Fred L. Whipple Observatory on Mount Hopkins (AZ). Seven spectra were recorded through 2009 March with an intensified photon-counting Reticon detector, and cover a narrow span of 45Å centered at 5190Å (MgIb triplet). The resolving power of this instrument was R~35000, and the signal-to-noise ratios of the spectra range from 13 to 22 per resolution element of 8.5km/s. Thirty seven additional spectra were gathered from 2009 November to 2015 February with the Tillinghast Reflector Echelle Spectrograph (TRES) on the same telescope. This bench-mounted, fiber-fed instrument provides a resolving power of R~44000 in 51 orders over the wavelength span 3900-9100Å. The signal-to-noise ratios of the 37 spectra range from 8 to 56 per resolution element of 6.8km/s. The heliocentric velocities we obtained from the DS and TRES spectra are listed in Table2. Between 2011 October and 2015 February we also obtained 57 usable spectra of V501 Mon with the Tennessee State University 2m Automatic Spectroscopic Telescope (AST) and a fiber-fed echelle spectrograph at Fairborn Observatory in southeast Arizona. The detector for these observations was a Fairchild 486 CCD, with 15μm pixels in a 4096*4096 format. The spectrograms have 48 orders ranging from 3800 to 8260Å. Because of the faintness of V501 Mon (V=12.32), we used a fiber that produced a spectral resolution of 0.4Å, corresponding to a resolving power of 15000 at 6000Å. Our spectra have typical signal-to-noise ratios per resolution element of 40 at 6000Å. We list the final values in Table3. An extensive program of CCD photometry was carried out using the NFO WebScope ear Silver City, New Mexico, for the purpose of gathering an accurate V-band light

  5. Anaerobic glycolysis and specific gravity of the red blood cells of rats exposed to pure oxygen at 600 torr.

    NASA Technical Reports Server (NTRS)

    Sabine, J. C.; Leon, H. A.

    1971-01-01

    Rats were exposed to 100% oxygen at 600 torr for up to 8 days. Highly significant increases in RBC anaerobic glycolysis occurred during the first 4 days of exposure and then subsided. Two significant peaks were found, one on days 1 and 2 and one on day 4. The first peak is attributed to reticulocytosis, which was maximal after 90 minutes and had disappeared by day 3. A second mechanism must account for the peak on day 4. An interpretation of the second peak is provided by existing evidence that selective removal of older RBCs occurs during the first few days of exposure to hypobaric oxygen, with maximum effect on day 4. Results in splenectomized, sham-operated and intact animals were indistinguishable from each other. A significant decrease in RBC specific gravity was found in exposed animals with spleens intact, but not in splenectomized animals. Theoretical aspects of age-related parameters as an aid to continuous detection and evaluation of changes in RBC populations are discussed.

  6. Early formation of gnammas (weathering pits) in a recently glaciated area of Torres del Paine, southern Patagonia (Chile)

    NASA Astrophysics Data System (ADS)

    Domínguez-Villar, David

    2006-06-01

    Incipient gnammas (weathering pits) were identified and measured in the Francés Valley of Torres del Paine, southern Patagonia. The gnammas were located on the granite blocks of a lateral moraine deposited during a Late Holocene neoglacial advance. The gnammas were measured for maximum and minimum depth, length, and width in addition to other observations. Based on these measurements, the surface area and the volume of the gnammas were calculated. Most of the gnammas have < 1 L of rock volume eroded, and the maximum depth is always < 10 cm. The gnammas do not develop erosional spillways. A high correlation exists between maximum and minimum depths, indicating these values are not completely independent. Thus, the depth ratio has been used to characterize the gnammas for discrete locations. The gnammas from Francés Valley belong to a unique normal population and a δ-value based on the depth ratio was defined to represent this population. The δ of Francés Valley is 1.33 ± 0.07, comparable with the lowest values of other stations around the globe. I suggest that the δ-value could be used as an indicator of gnamma evolution.

  7. EPIC Study of Two Enigmatic Sources: The Mouse and SNR 359.1-0.5

    NASA Technical Reports Server (NTRS)

    Pavlov, George

    2004-01-01

    The objective of the original proposal was to observe the Mouse pulsar wind nebula (associated with PSR J1744-2958) and the nearby supernova remnant G359.1-0.5, where the pulsar was probably born, with the XMM-Newton observatory to study the properties of these objects. SNR G359.1-0.5 was accepted as a Category C target and has not been observed. The Mouse was observed on April 27,2003 for 52 ks. The image analysis has shown that the Mouse is extended in the East-West direction, possibly along the direction of the pulsar's proper motion. The spectrum of this pulsar wind nebula can be described as an absorbed power law with the photon index GAMMA = 1.9 plus or minus 0.1, effective hydrogen column density n(sub H) = (2.6 plus or minus 0.1) x 10(exp 22) per square centimeter, and flux F = 1.8 x 10(exp -11) erg per square centimeter per second in the 1-10 keV energy range. Based on the n(sub H) value, the distance to the source is about 5 kpc, which results in the luminosity 3.7 x 10(exp 34) erg per second. We conclude that PSR J1744-2958 and the Mouse are not physically associated with G359.1-0.5, which lies at a larger distance. In addition to the Mouse, we also detected two Low-Mass X-ray Binaries, SLX 1744-299 and 1744-300, in the EPIC MOS and PN fields of view. The latter of these objects showed a Type I X-ray burst during our observation, with a rise time of 5 s and decay time of 60 s. A very strong pileup during the burst made the analysis of the burst properties unreliable. The spectral analysis of the persistent radiation from SLX 1744-299 and 1744-300 yields the hydrogen column densities of 3.2 plus or minus 0.1 and (3.6 plus or minus 0.2) x 10(exp 22) per square centimeter, respectively, which suggests that the sources are close to the Galactic center (d = 8-9 kpc). The spectra can be reasonably well fitted with a blackbody plus thin disk model, with the blackbody temperatures of 1.7 plus or minus 0.2 and 1.8 plus or minus 0.2 keV, respectively.

  8. A strategy for translating evidence into policy and practice to close the gap - developing essential service standards for Aboriginal and Torres Strait Islander cardiovascular care.

    PubMed

    Brown, Alex; O'Shea, Rebekah L; Mott, Kathy; McBride, Katharine F; Lawson, Tony; Jennings, Garry L R

    2015-02-01

    The development and application of essential standards for cardiovascular care for Aboriginal and Torres Strait Islander people creates a strategic platform on which to systematically close the gap in the health outcomes and life expectancy between Aboriginal and Torres Strait Islander and non-Indigenous people in Australia. We outline six developmental stages that can be used to enhance the effective translation of evidence into practice that reduces life expectancy differentials. Focussing efforts where the biggest gain can be made; considering how to make a policy-relevant difference with an emphasis on translation into policy and practice; establishing a foundation for action by engaging with stakeholders throughout the process; developing a framework to guide action; drafting policy-relevant and framework-appropriate essential service standards; and defining standards that help policy decision makers achieve current priority policy targets.

  9. Evolution of the mantle source in an evolving arc-backarc system (Torres del Paine, Patagonia): Evidence from Hf isotopes in zircon

    NASA Astrophysics Data System (ADS)

    Ewing, T. A.; Muntener, O.; Leuthold, J.; Baumgartner, L. P.; Putlitz, B.; d'Abzac, F. X.; Chiaradia, M.

    2015-12-01

    The Miocene Torres del Paine intrusive complex (TPIC) in Patagonia is a transitional alkaline backarc intrusion1 emplaced on short timescales of 162 ± 11 ka2. It is subdivided into two units with distinct ages of ~12.6 Ma and ~12.45 Ma1. Smaller intrusive bodies in the area record a change in chemistry from calc-alkaline at ~16 Ma, to transitional alkaline at ~12.5 Ma. Zircons from ~16 Ma intrusives and the 12.6 Ma part of the TPIC have remarkably consistent, slightly enriched Hf isotope compositions with ɛHf(i) of -1 to +2. An abrupt shift towards more juvenile Hf isotope compositions is observed in the ~12.45 Ma part of the TPIC, with ɛHf(i) of +3 to +6. Bulk rock Nd and Sr isotopes for the TPIC show the same shift towards more juvenile compositions at this time1. The long-term consistency of ɛHf(i) from 16 to 12.6 Ma is surprising, given that in the same period the bulk rock chemistry changes from calc-alkaline to transitional alkaline. Conversely, the major shift in ɛHf(i) is not correlated with any change in bulk rock chemistry, which remains transitional alkaline from 12.6 to 12.45 Ma. The decoupling of major element chemical evolution and Hf isotope signatures suggests that the subsequent rapid influx of juvenile material recorded by our Hf isotope data must have occurred by renewed mantle melting. Subduction of the Chile ridge at ~12.5 Ma in this area caused arc magmatism to move westwards and back-arc extension to initiate. We propose that the first TPIC magmas (12.6 Ma) came from a mantle wedge with a residual subduction signature. Subsequent melting of more juvenile mantle, less contaminated by a subduction component, generated the 12.45 Ma TPIC magmas. These results demonstrate that magmatic complexes such as the TPIC may tap distinct mantle sources even on very short timescales, fingerprinting arc-backarc transition processes. 1Leuthold et al., 2013, JPET, 54: 273-303 2Leuthold et al., 2012, EPSL, 325: 85-92

  10. ‘Choice, culture and confidence’: key findings from the 2012 having a baby in Queensland Aboriginal and Torres Strait Islander survey

    PubMed Central

    2014-01-01

    Background To describe the maternity care experiences of Aboriginal and/or Torres Strait Islander women in Queensland, Australia and to identify areas for policy and practice improvements. Methods A culturally-tailored survey requesting both quantitative and qualitative information was completed by respondents either independently (online or in hard copy) or with the assistance of a trained peer-interviewer. Data were analysed using descriptive statistics and thematic analysis. Eligible women were over 16 years of age, identified as Aboriginal and/or Torres Strait Islander, resided in Queensland, and had a live, singleton birth between the first of July 2011 and the first of July 2012. Results 187 women of 207 respondents were included in analyses. Women reported high rates of stressful life events in pregnancy, low levels of choice in place of birth and model of care and limited options to carry out cultural practices. High levels of confidence in parenting were also reported. Women were less likely to report being treated with kindness, understanding and respect by maternity care staff than women answering a similar mainstream survey. Conclusions Aboriginal and Torres Strait Islander women have additional needs to mainstream Australian women. This study identified a number of recommendations to improve services including the need to enhance the cultural competence of maternity services; increase access to continuity of midwifery care models, facilitate more choices in care, work with the strengths of Aboriginal and Torres Strait Islander women, families and communities, and engage women in the design and delivery of care. PMID:24884930

  11. Spatial clustering of toxic trace elements in adolescents around the Torreón, Mexico lead-zinc smelter.

    PubMed

    Garcia-Vargas, Gonzalo G; Rothenberg, Stephen J; Silbergeld, Ellen K; Weaver, Virginia; Zamoiski, Rachel; Resnick, Carol; Rubio-Andrade, Marisela; Parsons, Patrick J; Steuerwald, Amy J; Navas-Acién, Ana; Guallar, Eliseo

    2014-11-01

    High blood lead (BPb) levels in children and elevated soil and dust arsenic, cadmium, and lead were previously found in Torreón, northern Mexico, host to the world's fourth largest lead-zinc metal smelter. The objectives of this study were to determine spatial distributions of adolescents with higher BPb and creatinine-corrected urine total arsenic, cadmium, molybdenum, thallium, and uranium around the smelter. Cross-sectional study of 512 male and female subjects 12-15 years of age was conducted. We measured BPb by graphite furnace atomic absorption spectrometry and urine trace elements by inductively coupled plasma-mass spectrometry, with dynamic reaction cell mode for arsenic. We constructed multiple regression models including sociodemographic variables and adjusted for subject residence spatial correlation with spatial lag or error terms. We applied local indicators of spatial association statistics to model residuals to identify hot spots of significant spatial clusters of subjects with higher trace elements. We found spatial clusters of subjects with elevated BPb (range 3.6-14.7 μg/dl) and urine cadmium (0.18-1.14 μg/g creatinine) adjacent to and downwind of the smelter and elevated urine thallium (0.28-0.93 μg/g creatinine) and uranium (0.07-0.13 μg/g creatinine) near ore transport routes, former waste, and industrial discharge sites. The conclusion derived from this study was that spatial clustering of adolescents with high BPb and urine cadmium adjacent to and downwind of the smelter and residual waste pile, areas identified over a decade ago with high lead and cadmium in soil and dust, suggests that past and/or present plant operations continue to present health risks to children in those neighborhoods.

  12. Blue light differentially represses mesophyll conductance in high vs low latitude genotypes of Populus trichocarpa Torr. & Gray.

    PubMed

    Momayyezi, Mina; Guy, Robert D

    2017-03-16

    To explore what role chloroplast positioning might have in relation to latitudinal variation in mesophyll conductance (gm) of Populus trichocarpa Torr. & Gray (black cottonwood), we examined photosynthetic response to different blue light treatments in six representative genotypes (three northern and three southern). The proportion of blue (B) to red light was varied from 0:100, 10:90, 20:80, 40:60, and 60:40 while keeping the total photosynthetic photon flux density constant. Mesophyll conductance was estimated by monitoring chlorophyll fluorescence in combination with gas exchange. Compared to the control (10% B), gm was significantly lower with increasing blue light. Consistent with a change in chloroplast positioning, there was a simultaneous but reversible decrease in chlorophyll content index (CCI), as measured by foliar greenness, while the extracted, actual chlorophyll content (ACC) remained unchanged. Blue-light-induced decreases in gm and CCI were greater in northern genotypes than in southern genotypes, both absolutely and proportionally, consistent with their inherently higher photosynthetic rate. Treatment of leaves with cytochalasin D, an inhibitor of actin-based chloroplast motility, reduced both CCI and ACC but had no effect on the CCI/ACC ratio and fully blocked any effect of blue light on CCI. Cytochalasin D reduced gm by ∼56% under 10% B, but did not block the effect of 60% B on gm, which was reduced a further 20%. These results suggest that the effect of high blue light on gm is at least partially independent of chloroplast repositioning. High blue light reduced carbonic anhydrase activity by 20% (P<0.05), consistent with a possible reduction in protein-mediated facilitation of CO2 diffusion.

  13. Spatial clustering of toxic trace elements in adolescents around the Torreón, Mexico lead–zinc smelter

    PubMed Central

    Garcia-Vargas, Gonzalo G.; Rothenberg, Stephen J.; Silbergeld, Ellen K.; Weaver, Virginia; Zamoiski, Rachel; Resnick, Carol; Rubio-Andrade, Marisela; Parsons, Patrick J.; Steuerwald, Amy J.; Navas-Acién, Ana; Guallar, Eliseo

    2016-01-01

    High blood lead (BPb) levels in children and elevated soil and dust arsenic, cadmium, and lead were previously found in Torreón, northern Mexico, host to the world’s fourth largest lead–zinc metal smelter. The objectives of this study were to determine spatial distributions of adolescents with higher BPb and creatinine-corrected urine total arsenic, cadmium, molybdenum, thallium, and uranium around the smelter. Cross-sectional study of 512 male and female subjects 12–15 years of age was conducted. We measured BPb by graphite furnace atomic absorption spectrometry and urine trace elements by inductively coupled plasma-mass spectrometry, with dynamic reaction cell mode for arsenic. We constructed multiple regression models including sociodemographic variables and adjusted for subject residence spatial correlation with spatial lag or error terms. We applied local indicators of spatial association statistics to model residuals to identify hot spots of significant spatial clusters of subjects with higher trace elements. We found spatial clusters of subjects with elevated BPb (range 3.6–14.7 µg/dl) and urine cadmium (0.18–1.14 µg/g creatinine) adjacent to and downwind of the smelter and elevated urine thallium (0.28–0.93 µg/g creatinine) and uranium (0.07–0.13 µg/g creatinine) near ore transport routes, former waste, and industrial discharge sites. The conclusion derived from this study was that spatial clustering of adolescents with high BPb and urine cadmium adjacent to and downwind of the smelter and residual waste pile, areas identified over a decade ago with high lead and cadmium in soil and dust, suggests that past and/or present plant operations continue to present health risks to children in those neighborhoods. PMID:24549228

  14. A network approach to policy framing: A case study of the National Aboriginal and Torres Strait Islander Health Plan.

    PubMed

    Browne, Jennifer; de Leeuw, Evelyne; Gleeson, Deborah; Adams, Karen; Atkinson, Petah; Hayes, Rick

    2017-01-01

    Aboriginal health policy in Australia represents a unique policy subsystem comprising a diverse network of Aboriginal-specific and "mainstream" organisations, often with competing interests. This paper describes the network structure of organisations attempting to influence national Aboriginal health policy and examines how the different subgroups within the network approached the policy discourse. Public submissions made as part of a policy development process for the National Aboriginal and Torres Strait Islander Health Plan were analysed using a novel combination of network analysis and qualitative framing analysis. Other organisational actors in the network in each submission were identified, and relationships between them determined; these were used to generate a network map depicting the ties between actors. A qualitative framing analysis was undertaken, using inductive coding of the policy discourses in the submissions. The frames were overlaid with the network map to identify the relationship between the structure of the network and the way in which organisations framed Aboriginal health problems. Aboriginal organisations were central to the network and strongly connected with each other. The network consisted of several densely connected subgroups, whose central nodes were closely connected to one another. Each subgroup deployed a particular policy frame, with a frame of "system dysfunction" also adopted by all but one subgroup. Analysis of submissions revealed that many of the stakeholders in Aboriginal health policy actors are connected to one another. These connections help to drive the policy discourse. The combination of network and framing analysis illuminates competing interests within a network, and can assist advocacy organisations to identify which network members are most influential.

  15. Muir-Torre Syndrome

    MedlinePlus

    ... inner lining of the uterus CA-125 blood test to look for a protein found to be elevated in the blood of some women with ovarian cancer Screening options may change over time as new technologies are developed and more is learned about Muir- ...

  16. Summary of Data from the Sixth AIAA CFD Drag Prediction Workshop: CRM Cases 2 to 5

    NASA Technical Reports Server (NTRS)

    Tinoco, Edward N.; Brodersen, Olaf P.; Keye, Stefan; Laflin, Kelly R.; Feltrop, Edward; Vassberg, John C.; Mani, Mori; Rider, Ben; Wahls, Richard A.; Morrison, Joseph H.; Hue, David; Gariepy, Martin; Roy, Christopher J.; Mavriplis, Dimitri J.; Murayama, Mitsuhiro

    2017-01-01

    Results from the Sixth AIAA CFD Drag Prediction Workshop Common Research Model Cases 2 to 5 are presented. As with past workshops, numerical calculations are performed using industry-relevant geometry, methodology, and test cases. Cases 2 to 5 focused on force/moment and pressure predictions for the NASA Common Research Model wing-body and wing-body-nacelle-pylon configurations, including Case 2 - a grid refinement study and nacelle-pylon drag increment prediction study; Case 3 - an angle-of-attack buffet study; Case 4 - an optional wing-body grid adaption study; and Case 5 - an optional wing-body coupled aero-structural simulation. The Common Research Model geometry differed from previous workshops in that it was deformed to the appropriate static aeroelastic twist and deflection at each specified angle-of-attack. The grid refinement study used a common set of overset and unstructured grids, as well as user created Multiblock structured, unstructured, and Cartesian based grids. For the supplied common grids, six levels of refinement were created resulting in grids ranging from 7x10(exp 6) to 208x10(exp 6) cells. This study (Case 2) showed further reduced scatter from previous workshops, and very good prediction of the nacelle-pylon drag increment. Case 3 studied buffet onset at M=0.85 using the Medium grid (20 to 40x10(exp 6) nodes) from the above described sequence. The prescribed alpha sweep used finely spaced intervals through the zone where wing separation was expected to begin. Although the use of the prescribed aeroelastic twist and deflection at each angle-of-attack greatly improved the wing pressure distribution agreement with test data, many solutions still exhibited premature flow separation. The remaining solutions exhibited a significant spread of lift and pitching moment at each angle-of-attack, much of which can be attributed to excessive aft pressure loading and shock location variation. Four Case 4 grid adaption solutions were submitted. Starting

  17. Changes in exposure to ‘life stressors’ in the Aboriginal and Torres Strait Islander population, 2002 to 2008

    PubMed Central

    2014-01-01

    Background The Negative Life Events Scale (NLES) has been included in nationally representative surveys of the Indigenous and Australian population since 2002 as a measure of exposure to a range of ‘life stressors’. There has been limited reporting or analysis of estimates of the NLES from these surveys. This paper reports changes in exposure to stressors from 2002 to 2008 for the Indigenous population, and examines inter-relationships between eleven NLES items. Data for the 2006 Australian population is also included for comparative purposes. Methods Data from the 2002 and 2008 National Aboriginal and Torres Strait Islander Social Surveys (NATSISS) and the 2006 General Social Survey (GSS) were accessed from the Australia Bureau of Statistics in order to determine significant changes in exposure to stressors for the 2002 and 2008 Indigenous population by remoteness and to compare this with the 2006 Australian population. Factor analysis was used to assess the inter-relationships between stressors for the Indigenous and Australian population by remoteness. Results In remote locations, between 2002 and 2008, exposure to life stressors decreased significantly for the Indigenous population across seven of the eleven stressors. In non-remote locations, exposure to four of the stressors increased significantly. Exposure to stressors in the 2002 and 2008 non-remote Indigenous population were significantly higher than those for the 2006 Australian population for all items, except ‘alcohol and/or drug problems’ and ‘trouble with the police’, which showed no evidence of a difference. The factor analysis of the NLES for the 2002 and 2008 remote and non-remote Indigenous populations and the 2006 Australian population showed a consistent clustering of items into three groups: social transgressions; grief and trauma; and labour market stressors. Conclusions The reduction in exposure to life stressors for the remote Indigenous population may be related to policy and

  18. High-temperature metal purification using a compact, portable rf heating and levitation system on the wake shield

    NASA Technical Reports Server (NTRS)

    Hahs, C. A.

    1990-01-01

    The potential use of a compact, battery-operated rf levitator and heating system to purify high-temperature melting materials in space is described. The wake shield now being fabricated for the Space Vacuum Epitaxy Center will provide an Ultra-high vacuum (10(exp -14) Torr hydrogen, 10(exp -14) Torr helium, 10(exp -30) Torr oxygen). The use of the wake shield to purify Nb, Ti, W, Ir, and other metals to a purity level not achievable on earth is described.

  19. Toward 10(exp 10) Contrast for Terrestrial Exoplanet Detection: Demonstration of Wavefront Correction in a Shaped Pupil Coronagraph

    NASA Technical Reports Server (NTRS)

    Belikov, Ruslan; Give'on, Amir; Trauger, John T.; Carr, Michael; Kasdin, Jeremy N.; Vanderbei, Robert J.; Shi, Fang; Balasubramanian, Kunjithapatham; Kuhnert, Andreas

    2006-01-01

    Experimental demonstration of wavefront control with shaped pupils. Contrast level is maintained across different wavelengths and 10% broadband light. Further improvements in contrast believed to have been possible with more time and parameter optimizations.

  20. The morphology of 20 x 10 exp 6 K plasma in large non-impulsive solar flares

    NASA Technical Reports Server (NTRS)

    Acton, Loren W.; Feldman, Uri; Bruner, Marilyn E.; Doschek, George A.; Hirayama, Tadashi; Hudson, Hugh S.; Lemen, James R.; Ogawara, Yoshiaki; Strong, Keith T.; Tsuneta, Saku

    1992-01-01

    We have examined images of 10 flares observed by the Soft X-ray Telescope on-board the Yohkoh spacecraft. These images show that the hottest portion of the soft X-ray flare is located in compact regions that appear to be situated at the tops of loops. These compact regions form at, or shortly after, flare onset, and persist well into the decay phase of the flares. In some cases, the compact regions are only a few thousand kilometers in size and are small compared to the lengths of flaring loops. This is inconsistent with the smoother intensity distribution along the loops expected from models of chromospheric evaporation.

  1. Measurements of anisotropy in the cosmic microwave background radiation at 0.5 deg angular scales near the star gamma ursae minoris

    NASA Technical Reports Server (NTRS)

    Devlin, M. J.; Clapp, A. C.; Gundersen, J. O.; Hagmann, C. A.; Hristov, V. V.; Lange, A. E.; Lim, M. A.; Lubin, P. M.; Mauskopf, P. D.; Meinhold, P. R.

    1994-01-01

    We present results from a four-frequency observation of a 6 deg x 0.6 deg strip of the sky centered near the star Gamma Ursae Minoris (GUM) during the fourth flight of the Millimeter-wave Anistropy experiment(MAX). The observation was made with a 1.4 deg peak-to-peak sinusoidal chop in all bands. The FWHM beam sizes were 0.55 deg +/- 0.05 deg at 3.5 per cm and 0.75 deg +/- 0.05 deg at 6, 9, and 14 per cm. During this observation significant correlated structure was observed at 3.5, 6 and 9 per cm with amplitudes similar to those observed in the GUM region during the second and third fligts of MAX. The frequency spectrum is consistent with cosmic microwave background (CMB) and inconsistent with thermal emission from interstellar dust. The extrapolated amplitudes of synchrotron and free-free emission are too small to account for the amplitude of the observed structure, If all of the structure is attributed to CMB anisotropy with a Gaussian autocorrelation function and a coherence angle of 25 min, then the most probable values of delta T/T(sub CMB) in the 3.5, 6 and 9 per cm bads are (4.3 +2.7/-1.6) x 10(exp -5), 2.8 (+4.3/-1/1) x 10(exp -5), and 3.5 (+3.0/-1.6) x 10(exp -5) (95% confidence upper and lower limits), respectively.

  2. Magma Pulsing and Internal Structure of the Torres del Paine Laccolith (Patagonia) Constrained by High Precision Zircon U-Pb Dating, and Thermal and Crystal Size Modeling of its Contact Aureole.

    NASA Astrophysics Data System (ADS)

    Baumgartner, L. P.; Bodner, R.; Leuthold, J.; Muntener, O.; Putlitz, B.

    2014-12-01

    The shallow Torres del Paine Intrusive Complex (TPIC) belongs to a trench-parallel belt of igneous bodies in Southern Chile and Argentina. It is located in a transitional position between the Patagonia Batholith in the West, and the alkaline Cenozoic plateau lavas in the East. Volumetrically small amounts of magmatism started around 28 my ago in the Torres del Paine area. A second period occurred between 17-16 Ma, and igneous activity peaked with the TPIC 12.59-12.43 Ma ago. Finally, very minor magmatism occurred less than a million year ago. Intrusion depth, estimated based on contact metamorphic assemblages, decreased from ca. 10-12km at 17 Ma to ca. 3km at 12.5 Ma, the latter depth corresponding well with hornblende thermobarometry in mafic rocks and the water saturated granite solidus compositions observed. The TPIC is composed of a granitic laccolith emplaced over 90ka (1) in 3 several 100m thick sheets, forming an overall thickness of nearly 2 km. The granitic laccolith is under-plated by a ca. 400m thick mafic laccolith, built up over 50ka (2), constructed bottom up. Each sheet is itself composed of a multitude (>10) of metric to decametric pulses with mostly ductile contacts, resulting in outcrop patterns resembling braided stream sediments. Thermal modeling of the contact metamorphism, including heat of crystallization and the enthalpy of metamorphic reactions constrains the granite intrusion temperature to ca. 1000°C. Peak metamorphic temperatures suggest that intrusion of magma had to occur in a rapid succession of pulses, preferentially along the granite-host rock contact. Enthalpy released due to hydration of the biotite and feldspar of the immature sediments in the outer aureole contributed significantly to the far-field temperatures in the host-rock. Numerical crystal growth models matching the crystal size distribution indicate significant overstepping during onset of the contact metamorphic reactions. Nevertheless, sharp isogrades are predicted by

  3. Effect of Nb2O5 and V2O5 addition on the superconducting properties of YBa2Cu3O(y) thin films

    SciTech Connect

    Srinivas, S.; Bhatnagar, A.K.; Pinto, R.; Pai, S.P.; Apte, P.R.; Purandare, S.C.; Souza, C.P.D.

    1995-04-01

    The effect of Nb2O5 and V2O5 addition on the superconducting properties and microstructure of YBa2Cu3O(y) has been studied in thin films. Polycrystalline targets for laser ablation were prepared by mixing high purity V2O5 or Nb2O5 powders with a well characterized YBa2Cu3O(y) powder in the range 0 to 4 wt percent by solid state reaction method. Thin films (approximately 1500 A thickness) of the above targets were grown on (100) SrTiO3 (STO) and (100) LaAlO3 (LAO) substrates at 700 C temperature by pulsed laser deposition (PLD) technique. In the case of Nb2O5 addition the authors have noticed an increase in J(sub c) up to 0.5 wt percent and higher additive concentration (greater than 0.5 wt percent) have degraded the superconducting properties. However, in the case of V2O3 addition, there is an improvement in current density and microstructural properties up to 1 wt percent and the superconducting properties degrade for concentrations greater than 1 wt percent. The best J{sub c} for 0.5 wt percent of Nb2O5 added to YBCO thin film is 1.6 x 10(exp 6) A/sq cm and for that of V2O5 added sample is 3.4 x 10(exp 6) A/sq cm at 77 K as compared to the pure YBa2Cu3O(y) (YBCO) film J{sub c} (1.2 x 10(exp 6) A/sq cm) observed on STO substrates. The reason for improvement in J{sub c} and microstructural properties in the case of V2O5 addition could be due to the low melting of V2O5 (690 C) which can act as a very good surfactant during deposition. Over all, the authors have realized that Nb2O5 addition or V2O5 addition to YBCO have shown significant improvement over the undoped YBa2Cu3O(7-x) films grown under identical conditions.

  4. Effect of Nb2O5 and V2O5 addition on the superconducting properties of YBa2Cu3O(y) thin films

    NASA Technical Reports Server (NTRS)

    Srinivas, S.; Bhatnagar, A. K.; Pinto, R.; Pai, S. P.; Apte, P. R.; Purandare, S. C.; Souza, C. P. D.

    1995-01-01

    The effect of Nb2O5 and V2O5 addition on the superconducting properties and microstructure of YBa2Cu3O(y) has been studied in thin films. Polycrystalline targets for laser ablation were prepared by mixing high purity V2O5 or Nb2O5 powders with a well characterized YBa2Cu3O(y) powder in the range 0 to 4 wt percent by solid state reaction method. Thin films (approximately 1500 A thickness) of the above targets were grown on (100) SrTiO3 (STO) and (100) LaAlO3 (LAO) substrates at 700 C temperature by pulsed laser deposition (PLD) technique. In the case of Nb2O5 addition we have noticed an increase in J(sub c) up to 0.5 wt percent and higher additive concentration (greater than 0.5 wt percent) have degraded the superconducting properties. However, in the case of V2O3 addition, there is an improvement in current density and microstructural properties up to 1 wt percent and the superconducting properties degrade for concentrations greater than 1 wt percent. The best J(sub c) for 0.5 wt percent of Nb2O5 added YBCO thin film is 1.6 x 10(exp 6) A/sq cm and for that of V2O5 added sample is 3.4 x 10(exp 6) A/sq cm at 77 K as compared to the pure YBa2Cu3O(y) (YBCO) film J(sub c) (1.2 x 10(exp 6) A/sq cm) observed on STO substrates. The reason for improvement in J(sub c) and microstructural properties in the case of V2O5 addition could be due to the low melting of V2O5 (690 C) which can act as a very good surfactant during deposition. Over all, we have realized that Nb2O5 addition or V2O5 addition to YBCO have shown significant improvement over the undoped YBa2Cu3O(7-x) films grown under identical conditions.

  5. Tabulated Pressure Coefficient Data from a Tail Loads Investigation on a 1/15-Scale Model of the Goodyear XZP5K Airship

    NASA Technical Reports Server (NTRS)

    Cannon, Michael D.

    1956-01-01

    This paper contains tail and hull loads data obtained in an investigation of a l/15-scale model of the Goodyear XZP5K airship. Data are presented in the form of tabulated pressure coefficients over a pitch and yaw range of +/-20 deg and 0 deg to 30 deg respectively, with various rudder and elevator deflections. Two tail configurations of different plan forms were tested on the model. The investigation was conducted in the Langley full-scale tunnel at a Reynolds number of approximately 16.5 x 10(exp 6) based on hull length, which corresponds to a Mach number of about 0.12.

  6. Measurements of the anisotropy of the cosmic background radiation at 0.5 deg scale near the star Mu Pegasi

    NASA Technical Reports Server (NTRS)

    Meinhold, P.; Clapp, A.; Devlin, M.; Fischer, M.; Gundersen, J.; Holmes, W.; Lange, A.; Lubin, P.; Richards, P.; Smoot, G.

    1993-01-01

    Results are presented from the third flight of the MAX experiment, an attitude-controlled balloon-borne millimeter-wave telescope with a 0.5 deg beam, a 1 deg chop, and a three-channel bolometric photometer. Several hours of high-quality data were obtained during a flight on 1991 June 5, including long integrations to search for CBR anisotropy, two separate measurements of dust in the Galactic plane, a brief scan of the Coma Cluster to search for the Sunyaev-Zel'dovich (SZ) effect, and a number of important systematic tests. Data from one of the long CBR integrations, carried out in a region of sky near the star Mu Pegasi, are presented. The primary structure in the data is shown to be emission from Galactic dust via its spectrum and correlation with the IRAS 100/micron map. Several approaches are used to fit this dust component and remove it from the data. An upper limit to CBR anisotropy of deltaT/T less than 2.5 x 10 exp -5 is obtained for a Gaussian autocorrelation function with coherence angle omega(c) = 25'. This limit is significantly higher than the measurement sensitivity of deltaT/T about 1 x 10 exp -5 due to the presence of residual structure in the data after removal of the dust component.

  7. So far, so good: Maintenance of prevention is required to stem HIV incidence in Aboriginal and Torres Strait Islander communities in Australia.

    PubMed

    Ward, James; Costello-Czok, Michael; Willis, Jon; Saunders, Mark; Shannon, Cindy

    2014-06-01

    Indigenous people globally remain resilient yet vulnerable to the threats of HIV. Although Australian Aboriginal and Torres Strait Islander peoples experience the worst health status of any identifiable group in Australia, with a standardized morbidity rate three times that of non-Indigenous Australians, the Australian response to HIV has resulted in relatively low and stable rates of HIV infection among Australia's Indigenous peoples. This paper examines the reasons for the success of HIV prevention efforts. These include early recognition by Indigenous peoples of the potential effect that HIV could have on their communities; the supply of health hardware (needle and syringe programs and condoms); the development and implementation of culturally-appropriate health promotion messages such as the internationally-recognized Condoman campaign; the inclusion of dedicated Aboriginal and Torres Strait Islander Sexual Health Workers in communities; and an inclusive policy and partnership approach. Furthermore, the efforts of peak Aboriginal health organizations including NACCHO and its member services and Indigenous programs in peak mainstream organizations like AFAO and its member organizations, have all contributed to prevention success. Efforts need to be maintained however to ensure an escalated epidemic does not occur, particularly among heterosexual people, especially women, and people who inject drugs. New ideas are required as we enter a new era of HIV prevention within the context of the new paradigm of treatment as prevention, and getting to zero new infections.

  8. Upper limits to the detection of ammonia from protoplanetary disks around HL Tauri and L1551-IRS 5

    NASA Technical Reports Server (NTRS)

    Gomez, Jose F.; Torrelles, Jose M.; Ho, Paul T. P.; Rodriguez, Luis F.; Canto, Jorge

    1993-01-01

    We present NH3(1, 1) and (2, 2) observations of the young stellar sources HL Tau and L1551-IRS 5 using the VLA in its B-configuration, which provides an angular resolution of about 0.4 arcsec (about 50 AU at 140 pc) at 1.3 cm wavelength. Our goal was to detect and resolve circumstellar molecular disks with radius of the order of 100 AU around these two sources. No ammonia emission was detected toward either of them. The 3-sigma levels were 2.7 mJy/beam and 3.9 mJy/beam for HL Tau and L1551-IRS 5, respectively, with a velocity resolution of about 5 km/s. With this nondetection, we estimate upper limits to the mass of the proposed protoplanetary molecular disks (within a radius of 10 AU from the central stars) on the order of 0.02/(X(NH3)/10 exp -8) solar mass for HL Tau and 0.1/(X(NH3)/10 exp -8) solar mass for L1551-IRS 5.

  9. HCl dissolved in solid mixtures of nitric acid and ice - Implications for the polar stratosphere

    NASA Technical Reports Server (NTRS)

    Marti, James; Mauersberger, Konrad; Hanson, David

    1991-01-01

    The solubility of HCl in polar stratospheric cloud (PSC) particles plays an important role in the heterogeneous chemistry of the lower polar stratosphere. New laboratory studies are reported showing a strong dependence of the HCl solubility on the HNO3 content in ice particles. At 200 K and a partial HCl pressure of 10 exp -6 torr, the HCl content in NAT is 0.35 mol pct, decreasing about a factor of 3 for every ten-fold decrease in the substrate's HNO3 content. At an HCl pressure of 10 exp -7 torr, the content is about 40 percent of that at 10 exp -6 torr. HCL dissolved in pure water ice at these partial pressures is less than 0.002 mol pct. The surface coverage of HCl on small ice samples was estimated to be about 0.1 monolayer at 10 exp -6 torr exposure.

  10. Kinetics of the Reactions of IO Radicals with NO and NO2

    NASA Technical Reports Server (NTRS)

    Daykin, E. P.; Wine, P. H.

    1997-01-01

    A laser flash photolysis-long path absorption technique has been employed to study the kinetics of the reactions of IO radicals with NO and NO2 as a function of temperature and pressure. The IO and NO rate coefficient is independent of pressure over the range 40-200 Torr of N2, and its temperature dependence over the range 242-359 K is adequately described by the Arrhenius expression k(sub 1) = (6.9 +/- 1.7) x 10(exp -12) exp[(328 +/- 71)/T] cu cm/(molecule.s) (errors are 2 sigma, precision only). These Arrhenius parameters are similar to those determined previously for the ClO + NO and BrO + NO reactions. The IO and NO2 association reaction is found to be in the falloff regime over the temperature and pressure ranges investigated (254-354 K and 40-750 Torr of N2). Assuming F(sub c) = 0.4 independent of temperature, a physically reasonable set of falloff parameters which adequately describe the data are k(sub 0) = 7.7 x 10(exp -31)(T/300)(exp -5.0) cm(exp 6)/(molecule(exp 2).s) and k(sub infinity) = 1.55 x 10(exp -11)cu cm/(molecule.s) independent of temperature. The IO + NO2 rate coefficients determined in this study are about a factor of 2 faster than those reported in the only previous study of this reaction.

  11. RXTE and BeppoSAX Observations of MCG-5-23-16: Reflection From Distant Cold Material

    NASA Technical Reports Server (NTRS)

    Mattson, B. J.; Weaver, K. A.

    2003-01-01

    We examine the spectral variability of the Seyfert 1.9 galaxy MCG-5-23-16 using RXTE and BeppoSAX observations spanning 2 years from April 1996 to April 1998. During the first year the X-ray source brightens by a factor of approximately 25% on timescales of days to months. During this time, the reprocessed continuum emission seen with RXTE does not respond measurably to the continuum increase. However, by the end of the second year during the BeppoSAX epoch the X-ray source has faded again. This time, the reprocessed emission has also faded, indicating that the reprocessed flux has responded to the continuum. If these effects are caused by time delays due to the distance between the X-ray source and the reprocessing region, we derive a light crossing time of between approximately 1 light day and approximately 1.5 light years. This corresponds to a distance of 0.001 pc to 0.55 pc, which implies that the reprocessed emission originates between 3 x 10(exp 15) cm and 1.6 x 10(exp l8) cm from the X-ray source. In other words, the reprocessing in MCG-5-23-16 is not dominated by the inner regions of a standard accretion disk.

  12. Low earth orbit durability evaluation of Haynes 188 solar receiver material

    SciTech Connect

    De groh, K.K.; Rutledge, S.K.; Burke, C.A.; Dever, T.M.; Olle, R.M.; Terlep, J.A. Cleveland State University, OH Ohio Aerospace Institute, Cleveland )

    1992-01-01

    The effects of elevated-temperature vacuum and elevated-temperature atomic oxygen exposure on the mass, surface chemistry, surface morphology, and optical properties of Haynes 188, a possible heat receiver material for space-based solar dynamic power systems, have been studied. Pristine and surface modified Haynes 188 were exposed to vacuum less than or equal to 10 exp -6 torr at 820 C for 5215.5 h, and to atomic oxygen in an air plasma asher at 34 and 827 C for fluences up to 5.6 x 10 exp 21 atoms/sq cm. Results obtained indicate that vacuum heat treatment caused surface morphology and chemistry changes with corresponding optical property changes. Atomic oxygen exposure caused optical property changes which diminished with time. Mass changes are considered to be negligible for both exposures. 11 refs.

  13. Low earth orbit durability evaluation of Haynes 188 solar receiver material

    NASA Technical Reports Server (NTRS)

    De Groh, Kim K.; Rutledge, Sharon K.; Burke, Christopher A.; Dever, Therese M.; Olle, Raymond M.; Terlep, Judith A.

    1992-01-01

    The effects of elevated-temperature vacuum and elevated-temperature atomic oxygen exposure on the mass, surface chemistry, surface morphology, and optical properties of Haynes 188, a possible heat receiver material for space-based solar dynamic power systems, have been studied. Pristine and surface modified Haynes 188 were exposed to vacuum less than or equal to 10 exp -6 torr at 820 C for 5215.5 h, and to atomic oxygen in an air plasma asher at 34 and 827 C for fluences up to 5.6 x 10 exp 21 atoms/sq cm. Results obtained indicate that vacuum heat treatment caused surface morphology and chemistry changes with corresponding optical property changes. Atomic oxygen exposure caused optical property changes which diminished with time. Mass changes are considered to be negligible for both exposures.

  14. Lithofacies analysis of basic lava flows of the Paraná igneous province in the south hinge of Torres Syncline, Southern Brazil

    NASA Astrophysics Data System (ADS)

    Barreto, Carla Joana Santos; de Lima, Evandro Fernandes; Scherer, Claiton Marlon; Rossetti, Lucas de Magalhães May

    2014-09-01

    The Paraná igneous province records the volcanism of the earlier Cretaceous that preceded the fragmentation of the Gondwana supercontinent. Historically, investigations of these rocks prioritized the acquisition of geochemical and isotopic data, considering the volcanic pile as a monotonous succession of tabular flows. This work provides a detailed analysis of the emplacement conditions of these basic volcanic rocks, applying the facies analysis method integrated to petrographic and geochemical data. The Torres Syncline is a NW-SE tectonic structure, located in southern Brazil, where a thick sequence of the Paraná-Etendeka volcanic rocks is well preserved. This study was performed in the south hinge of the syncline, where the basaltic lava flows are divided into three lithofacies associations: early compound pahoehoe, early simple pahoehoe and late simple rubbly. The first lavas that erupted were more primitive compound pahoehoe flow fields composed of olivine basalts with higher MgO contents and covered the sandstones of the Botucatu Formation. The emplacement of compound pahoehoe flow fields is possibly related to intermittent low effusion rates, whereas the emplacement of simple pahoehoe is related to sustained low effusion rates with continuous supply. The thick simple rubbly lavas are associated with high effusion rates and were formed during the main phase of volcanism in the area. The absence of paleosoils between the lavas and lithofacies associations suggests that the successive emplacement of the lava flows occurred in a relatively short time gap. Geochemically, the lithofacies associations are low-TiO2 and belong to Gramado magma type. The lavas of the south hinge of the Torres Syncline have a similar evolution when compared to other Continental Basaltic Provinces with earlier compound flows at the base and thicker simple flows in the upper portions.

  15. The sealing capacity of the cap rock above the Torre Alfina geothermal reservoir (Central Italy) revealed by soil CO2 flux investigations

    NASA Astrophysics Data System (ADS)

    Carapezza, Maria Luisa; Ranaldi, Massimo; Gattuso, Alessandro; Pagliuca, Nicola Mauro; Tarchini, Luca

    2015-01-01

    Torre Alfina is a medium enthalpy (T = 140 °C) geothermal field in Central Italy, hosted in buried fractured Mesozoic limestones, extensively explored in the 1970s and 1980s, but which so far has not been exploited. A detailed diffuse soil CO2 flux investigation (1336 measurements over a surface of 12.6 km2) and the periodic monitoring of soil CO2 flux from target areas indicate that in most of the area, even above a pressurized gas cap existing at the reservoir top, the soil CO2 flux is low and mostly within the background threshold (48 g m- 2 day- 1) and is likely generated by biological soil respiration. Anomalous values (up to 30.250 g m- 2 day- 1) are found only in the proximity of a small zone with gas vents whose composition is identical to that of the gas produced by the geothermal wells tapping the reservoir. This is the only zone where a fault connecting the deep geothermal reservoir with the surface does exist. These data are compared with those of the near Latera high enthalpy geothermal field (T = 210 °C), where anomalous soil CO2 flux is recorded above the productive reservoir. The difference of soil CO2 release in the two fields is attributed to the differences in the impervious cover (allochthonous flysch deposits) above the carbonate reservoir, which is thin and locally lacking at Latera, and continuous and thick (> 400 m) at Torre Alfina. Results demonstrate that soil CO2 flux investigations are useful in geothermal exploration, but only high flux values likely indicate the presence of a geothermal reservoir at depth, whereas low flux values can indicate either the lack of an active geothermal reservoir at depth or the presence of a very effective impervious cover above the reservoir.

  16. Exploring potential dietary contributions including traditional seafood and other determinants of urinary cadmium levels among indigenous women of a Torres Strait Island (Australia).

    PubMed

    Haswell-Elkins, Melissa; McGrath, Victor; Moore, Michael; Satarug, Soisungwan; Walmby, Maria; Ng, Jack

    2007-05-01

    Indigenous people of the Torres Strait Islands have been concerned about the safety of their traditional seafoods since the discovery of high cadmium levels in the liver and kidney of dugong and turtle in 1996. This study explored links between urinary cadmium levels and consumption frequency of these traditional foods and piloted a community-based methodology to identify potential determinants of cadmium exposure and accumulation. Consultations led to selection of one community for study from which 60 women aged 30 to 50 years participated in health and food frequency survey, urine collection and a routine health check. Urinary cadmium levels were determined by inductively coupled plasma-mass spectrometry; data were analysed using SPSS-14. The geometric mean cadmium level in this group of women was 1.17 (arithmetic mean 1.86) microg/g creatinine with one-third exceeding 2.0 microg/g creatinine. Heavy smoking (>or=300 pack years) was linked to higher cadmium in urine, as was increasing age and waist circumference. Analysis of age-adjusted residuals revealed significant associations (P<0.05) between cadmium level and higher consumption of turtle liver and kidney, locally gathered clams, peanuts, coconut, chocolate and potato chips. Dugong kidney consumption approached significance (P=0.06). Multiple regression revealed that 40% (adjusted r(2)) of variation in cadmium level was explained by the sum of these associated foods plus heavy smoking, age and waist circumference. No relationships between cadmium and pregnancy history were found. This paper presents a novel approach to explore contributions of foods and other factors to exposure to toxins at community level and the first direct evidence that frequent turtle (and possibly dugong) liver and kidney and wild clam consumption is linked to higher urinary cadmium levels among Torres Strait Islander women.

  17. The 5 Hour Pulse Period and Broadband Spectrum of the Symbiotic X-Ray Binary 3A 1954+319

    NASA Technical Reports Server (NTRS)

    Marcu, Diana M.; Fuerst, Felix; Pottschmidt, Katja; Grinberg, Victoria; Miller, Sebstian; Wilms, Joern; Postnov, Konstantin A.; Corbet, Robin H. D.; Markwardt, Craig B.; Cadolle Bel, Marion

    2011-01-01

    We present an analysis of the highly variable accreting X-ray pulsar 3A 1954+319 using 2005-2009 monitoring data obtained with INTEGRAL and Swift. This considerably extends the pulse period history and covers flaring episodes in 2005 and 2008. In 2006 the source was identified as one of only a few known symbiotic X-ray binaries, Le" systems composed of a neutron star accreting from the inhomogeneous medium around an M-giant star. The extremely long pulse period of approximately 5.3 h is directly visible in the 2008 INTEGRAL-ISGRI outburst light curve. The pulse profile is double peaked and not significantly energy dependent. During the outburst a strong spin-up of -1.8 x 10(exp -4) h h(exp -1) occurred. Between 2005 and 2008 a long term spin-down trend of 2.1 x 10(exp -5) h h(exp -1) was observed for the first time for this source. The 3-80 keV pulse peak spectrum of 3A 1954+319 during the 2008 flare could be well described by a thermal Comptonization model. We interpret the results within the framework of a recently developed quasi-spherical accretion model for symbiotic X-ray binaries.

  18. Experimental aerodynamic characteristics of a generic hypersonic accelerator configuration at Mach numbers 1.5 and 2.0. [conducted in the Langley Unitary Plan Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Walker, Ira J.; Covell, Peter F.; Forrest, Dana K.

    1993-01-01

    An experimental investigation of the static longitudinal and lateral-directional aerodynamic characteristics of a generic hypersonic research vehicle was conducted in the Langley Unitary Plan Wind Tunnel (UPWT). A parametric study was performed to determine the interference effects of various model components. Configuration variables included delta and trapezoidal canards; large and small centerline-mounted vertical tails, along with a set of wing-mounted vertical tails; and a set of model noses with different degrees of bluntness. Wing position was varied by changing the longitudinal location and the incidence angle. The test Mach numbers were 1.5 and 2.0 at Reynolds numbers of 1 x 10(exp 6) per foot, 2 x 10(exp 6) per foot, and 4 x 10(exp 6) per foot. Angle of attack was varied from -4 degrees to 27 degrees, and sideslip angle was varied from -8 degrees to 8 degrees. Generally, the effect of Reynolds number did not deviate from conventional trends. The longitudinal stability and lift-curve slope decreased with increasing Mach number. As the wing was shifted rearward, the lift-curve slope decreased and the longitudinal stability increased. Also, the wing-mounted vertical tails resulted in a more longitudinally stable configuration. In general, the lift-drag ratio was not significantly affected by vertical-tail arrangement. The best lateral-directional stability was achieved with the large centerline-mounted tail, although the wing-mounted vertical tails exhibited the most favorable characteristics at the higher angles of attack.

  19. Correlating metastable-atom density, reduced electric field, and electron energy distribution in the post-transient stage of a 1-Torr argon discharge

    NASA Astrophysics Data System (ADS)

    Franek, J. B.; Nogami, S. H.; Demidov, V. I.; Koepke, M. E.; Barnat, E. V.

    2015-06-01

    Temporal measurement of electron density, metastable-atom density, and reduced electric field are used to infer the dynamic behavior of the excitation rates describing electron-atom collision-induced excitation in the positive column of a 1 Torr argon plasma by invoking plausible assumptions regarding the shape of the electron energy distribution function performed in Adams et al (2012 Phys. Plasmas 19 023510). These inferred rates are used to predict the 420.1 nm to 419.8 nm argon emission ratio, which agree with experimental results when the assumptions are applicable. Thus the observed emission ratio is demonstrated to be dependent on the metastable-atom density, electron density, and reduced electric field. The established confidence in the validity of this emission-line-ratio model allows us to predict metastable argon-atom density during the post-transient phase of the pulse as suggested by De Joseph et al (2005 Phys. Rev. E 72 036410). Similar inferences of electron density and reduced electric field based on readily available diagnostic signatures may also be afforded by this model.

  20. Alcohol-Related Violence among the Australian Aboriginal and Torres Strait Islanders of the Northern Territory: Prioritizing an Agenda for Prevention-Narrative Review Article.

    PubMed

    Ramamoorthi, Ramya; Jayaraj, Rama; Notaras, Leonard; Thomas, Mahiban

    2014-05-01

    Alcohol - related violence among Australian Aboriginal and Torres Strait Islanders (also called as "Indigenous") is a major public health concern in Northern Territory of Australia. There is dearth of epidemiological data that link three contributing epidemics: alcohol misuse, violence, and trauma in the Northern Territory. In this review, we aimed to concentrate on how these epidemics intersect among the Indigenous people in the Northern Territory. In our descriptive review, we have searched published papers, publicly available government and health department reports web sites reporting relevant data on these three risk factors in the Northern Territory. The high rate of family and domestic violence and assaults in the Australian Territory indicates an increased correlation with high risk alcohol use compared to unintentional injuries. Heavy drinking pattern and harmful use of alcohol among Indigenous people are more likely to be associated with the incidence of violent assaults and physical injuries in the Northern Territory. We are trying to emphasize our understanding of co-occurring risk factors on the alcohol - violence relationship and urging a need for interventional approaches to reduce the public health issues in the Northern Territory.

  1. Nodular trombiculinosis caused by Apolonia tigipioensis, Torres and Braga (1938), in an ostrich (Struthio camelus) and a house sparrow (Passer domesticus).

    PubMed

    Ornelas-Almeida, Maria Angela; de Oliveira, Flávio Ramos Bastos; da Silva, Alessandra Estrela; Moreira, Eduardo Luiz Trindade; Maia, Paulo César Costa; de Fátima Cardoso Duarte, Larissa; Murphy, Gleeson; Ayres, Maria Consuelo Caribe

    2007-12-25

    Nodular trombiculinosis has been reported in Brazil in chickens [Torres, S., Braga, W., 1939. Apolonia tigipioensis, g. e sp. n. (Trombiculinae) parasito de Gallus gallus dom. Chave para determinação de gêneros. Boletim da S.A.I.C. 4, 37-44] and humans [Carneiro, L.S., 1952. Uma nova acaríase humana - Contribuição ao seu estudo. Imprensa Industrial, Recife. Faculdade de Medicina da Universidade do Recife, Tese Livre Docência, p. 56]. In this report, a juvenile ostrich and a house sparrow, both originating from a riverside property in the town of Petrolina in the state of Pernambuco, presented 87 and eight nodules, respectively, on various locations of their bodies. Physical expression of the nodules liberated parasites that were morphologically identified as mites from the family Trombiculidae. The mites were further identified as Apolonia tigipioensis by the presence of an elongated body form and transversely striated, three pairs of long legs each with seven segments, primary coxae with a single seta, each tarsus terminating with three claws, and a scutum with an anteromedian projection and paired anteromedian setae. Histopathologic examination of skin biopsies from these birds, stained with hematoxilin-eosin, revealed acute parasitic cystic lymphoplasmacytic dermatitis.

  2. Rapid Activation of Phenylpropanoid Metabolism in Elicitor-Treated Hybrid Poplar (Populus trichocarpa Torr. & Gray × Populus deltoides Marsh) Suspension-Cultured Cells 1

    PubMed Central

    de Sá, Mário Moniz; Subramaniam, Rajgopal; Williams, Frank E.; Douglas, Carl J.

    1992-01-01

    Elicitor induction of phenylpropanoid metabolism was investigated in suspension-cultured cells of the fast-growing poplar hybrid (Populus trichocarpa Torr. & Gray × Populus deltoides Marsh) H11-11. Treatment of cells with polygalacturonic acid lyase or two fungal elicitors resulted in rapid and transient increases in extractable l-phenylalanine ammonia lyase and 4-coumarate:coenzyme A ligase enzyme activities. The substrate specificity of the inducible 4-coumarate:coenzyme A ligase enzyme activity appeared to differ from substrate specificity of 4-coumarate:coenzyme A ligase enzyme activity in untreated control cells. Large and transient increases in the accumulation of l-phenylalanine ammonia-lyase and 4-coumarate:coenzyme A ligase mRNAs preceded the increases in enzyme activities and were detectable by 30 minutes after the start of elicitor treatment. Chalcone synthase, cinnamyl alcohol dehydrogenase, and coniferin β-glucosidase enzyme activities were unaffected by the elicitors, but a large and transient increase in β-glucosidase activity capable of hydrolyzing 4-nitrophenyl-β-glucoside was observed. Subsequent to increases in l-phenylalanine ammonialyase and 4-coumarate:coenzyme A ligase enzyme activities, cell wall-bound thioglycolic acid-extractable compounds accumulated in elicitor-treated cultures, and these cells exhibited strong staining with phloroglucinol, suggesting the accumulation of wall-bound phenolic compounds. ImagesFigure 7Figure 9 PMID:16668702

  3. RX J1856.5-3754: A Strange Star with Solid Quark Surface?

    NASA Technical Reports Server (NTRS)

    Zhang, Xiaoling; Xu, Renxin; Zhang, Shuangnan

    2003-01-01

    The featureless spectra of isolated 'neutron stars' may indicate that they are actually bare strange stars but a definitive conclusion on the nature of the compact objects cannot be reached until accurate and theoretically calculated spectra of the bare quark surface are known. However due to the complex nonlinearity of quantum chromodynamics it is almost impossible to present a definitive and accurate calculation of the density-dominated quark-gluon plasma from the first principles. Nevertheless it was suggested that cold quark matter with extremely high baryon density could be in a solid state. Within the realms of this possibility we have fitted the 500ks Chandra LETG/HRC data for the brightest isolated neutron star RX 51856.5-3754 with a phenomenological spectral model and found that electric conductivity of quark matter on the stellar surface is about 1.5 x 10(exp 16)/s.

  4. X-ray Spectra and Pulse Frequency Changes in SAX J2103.5+4545

    NASA Technical Reports Server (NTRS)

    Baykal, A.; Stark, M. J.; Swank, J. H.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    The November 1999 outburst of the transient pulsar SAX J2103.5+4545 was monitored with the large area detectors of the Rossi X-Ray Timing Explorer until the pulsar faded after a year. The 358 s pulsar was spun up for 150 days, at which point the flux dropped quickly by a factor of approximately 7, the frequency saturated and, as the flux continued to decline, a weak spin-down began. The pulses remained strong during the decay and the spin-up/flux correlation can be fit to the Ghosh and Lamb derivations for the spin-up caused by accretion from a thin, pressure-dominated disk, for a distance approximately 3.2 kpc and a surface magnetic field approximately 1.2 x 10(exp 13) Gauss. During the bright spin-up part of the outburst, the flux was subject to strong orbital modulation, peaking approximately 3 days after periastron of the eccentric 12.68 day orbit, while during the faint part, there was little orbital modulation. The X-ray spectra were typical of accreting pulsars, describable by a cut-off power-law, with an emission line near the 6.4 keV of Kappa(sub alpha) fluorescence from cool iron. The equivalent width of this emission did not share the orbital modulation, but nearly doubled during the faint phase, despite little change in the column density. The outburst could have been caused by an episode of increased wind from a Be star, such that a small accretion disk is formed during each periastron passage. A change in the wind and disk structure apparently occurred after 5 months such that the accretion rate was no longer modulated or the diffusion time was longer. The distance estimate implies the X-ray luminosity observed was between 1 X 10(exp 36) ergs s(exp -1) and 6 x 10(exp 34) ergs s(exp -1), with a small but definite correlation of the intrinsic power-law spectral index.

  5. The effective thermal conductivity of an adsorbent - Praseodymium cerium oxide

    NASA Technical Reports Server (NTRS)

    Secary, J. J.; Tong, T. W.

    1992-01-01

    The results of an experimental study to determine the effective thermal conductivity of praseodymium cerium oxide are reported. Praseodymium cerium oxide is an adsorbent used in the development of adsorption compressors for spaceborne refrigeration systems. A guarded-hot-plate apparatus was built for this study. Measurements were carried out for mean temperatures ranging from 300 to 600 C under a vacuum of 10 exp -5 torr. For the temperature range studied, the effective thermal conductivity increased from 0.14 to 0.76 W/m per C with increasing temperature, while displaying a cubic temperature dependency.

  6. Preferential polarization and its reversal in polycrystalline BiFeO3/La0.5Sr0.5CoO3 heterostructures

    NASA Astrophysics Data System (ADS)

    Roy Choudhury, Palash; Parui, Jayanta; Chiniwar, Santosh; Krupanidhi, S. B.

    2015-04-01

    Polycrystalline BiFeO3 thin films were grown on La0.5Sr0.5CoO3 buffered Pt (200)/TiO2/SiO2/Si substrates under different oxygen partial pressures (10, 25, 50 and 100 mTorr) by pulsed laser ablation. Piezoresponse Force Microscopy and Piezo-Force Spectroscopy have shown that all the films are ferroelectric in nature with locally switchable domains. It has also revealed a preferential downward domain orientation in as-grown films grown under lower oxygen partial pressure (10 and 25 mTorr) with a reversal of preferential domain orientation as the oxygen partial pressure is increased to 100 mTorr during laser ablation. Such phenomena are atypical of multi-grained polycrystalline ferroelectric films and have been discussed on the basis of defect formation with changing growth conditions. For the 50 mTorr grown film, asymmetric domain stability and retention during write-read studies has been observed which is attributed to grain-size-related defect concentration, affecting pinning centres that inhibit domain wall motion.

  7. Ammonia adsorption and its effects on framework stability of MOF-5 and MOF-177.

    PubMed

    Saha, Dipendu; Deng, Shuguang

    2010-08-15

    Ammonia adsorption equilibrium and kinetics on MOF-5 and MOF-177 were measured volumetrically at 298 K and ammonia pressures up to 800 torr. This study allowed us to determine the ammonia adsorption properties and stability of both MOFs after exposure to ammonia. MOF-177 adsorbed more ammonia than MOF-5 at ammonia pressures below 150 torr and the ammonia adsorption capacity on both MOFs at 800 torr was about the same (12.2 mmol/g). It can be inferred from the adsorption results that physical adsorption of ammonia on both MOFs dominated at ammonia pressures below 150 torr after which chemical reactions between ammonia and MOF frameworks take place. After exposure to ammonia both MOFs lost majority of their pore textures as evidenced by a drastic decrease of specific surface area and pore volume. The X-ray diffraction study suggested a complete loss of crystallinity of both MOFs, and the FT-IR and Raman spectral analyses showed the generation of free organic ligands within both MOF-5 and MOF-177 after they were exposed to ammonia. Ammonia molecules are proposed to destroy the MOF frameworks by forming hydrogen bonds with Zn(4)O clusters of MOFs.

  8. Rate Constant for the Reaction CH3 + CH3 Yields C2H6 at T = 155 K and Model Calculation of the CH3 Abundance in the Atmospheres of Saturn and Neptune

    NASA Technical Reports Server (NTRS)

    Cody, Regina J.; Romani, Paul N.; Nesbitt, Fred L.; Iannone, Mark A.; Tardy, Dwight C.; Stief, Louis J.

    2003-01-01

    The column abundances of CH3 observed by the Infrared Space Observatory (ISO) satellite on Saturn and Neptune were lower than predicted by atmospheric photochemical models, especially for Saturn. It has been suggested that the models underestimated the loss of CH3 due to poor knowledge of the rate constant k of the CH3 + CH3 self-reaction at the low temperatures and pressures of these atmospheres. Motivated by this suggestion, we undertook a combined experimental and photochemical modeling study of the CH3 + CH3 reaction and its role in determining planetary CH3 abundances. In a discharge flow-mass spectrometer system, k was measured at T = 155 K and three pressures of He. The results in units of cu cm/molecule/s are k(0.6 Torr) = 6.82 x 10(exp -11), k(1.0 Torr) = 6.98 x 10(exp -11), and k(1.5 Torr) = 6.91 x 10(exp -11). Analytical expressions for k were derived that (1) are consistent with the present laboratory data at T = 155 K, our previous data at T = 202 K and 298 K, and those of other studies in He at T = 296-298 K and (2) have some theoretical basis to provide justification for extrapolation. The derived analytical expressions were then used in atmospheric photochemical models for both Saturn and Neptune. These model results reduced the disparity with observations of Saturn, but not with observations of Neptune. However, the disparity for Neptune is much smaller. The solution to the remaining excess CH3 prediction in the models relative to the ISO observations lies, to a large extent, elsewhere in the CH3 photochemistry or transport, not in the CH3 + CH3 rate.

  9. NuSTAR Observations of Heavily Obscured Quasars at z Is Approximately 0.5

    NASA Technical Reports Server (NTRS)

    Lansbury, G. B.; Alexander, D. M.; Del Moro, A.; Gandhi, P.; Assef, R. J.; Stern, D.; Aird, J.; Ballantyne, D. R.; Balokovic, M.; Bauer, F. E.; Boggs, S. E.; Brandt, W. N.; Christensen, F. E.; Craig, W. W.; Elvis, M.; Grefenstette, B. W.; Hailey, C. J.; Harrison, F. A.; Hickox, R. C.; Koss, M.; LaMassa, S. M.; Luo, B.; Mullaney, J. R.; Teng, S. H.; Urry, C. M.; Zhang, W. W.

    2014-01-01

    We present NuSTAR hard X-ray observations of three Type 2 quasars at z approx. = 0.4-0.5, optically selected from the Sloan Digital Sky Survey. Although the quasars show evidence for being heavily obscured, Compton-thick systems on the basis of the 2-10 keV to [O(sub III)] luminosity ratio and multiwavelength diagnostics, their X-ray absorbing column densities (N(sub H)) are poorly known. In this analysis, (1) we study X-ray emission at greater than 10 keV, where X-rays from the central black hole are relatively unabsorbed, in order to better constrain N(sub H). (2) We further characterize the physical properties of the sources through broad-band near-UV to mid-IR spectral energy distribution analyses. One of the quasars is detected with NuSTAR at greater than 8 keV with a no-source probability of less than 0.1%, and its X-ray band ratio suggests near Compton-thick absorption with N(sub H) is approximately greater than 5 × 10(exp 23) cm(exp -2). The other two quasars are undetected, and have low X-ray to mid-IR luminosity ratios in both the low-energy (2-10 keV) and high-energy (10-40 keV) X-ray regimes that are consistent with extreme, Compton-thick absorption (N(sub H) is approximately greater than 10(exp 24) cm(exp -2)). We find that for quasars at z is approximately 0.5, NuSTAR provides a significant improvement compared to lower energy (less than 10 keV) Chandra and XMM-Newton observations alone, as higher column densities can now be directly constrained.

  10. Direct effects of soil amendments on field emergence and growth of the invasive annual grass Bromus tectorum L. and the native perennial grass Hilaria jamesii (Torr.) Benth

    USGS Publications Warehouse

    Newingham, B.A.; Belnap, J.

    2006-01-01

    Bromus tectorum L. is a non-native, annual grass that has invaded western North America. In SE Utah, B. tectorum generally occurs in grasslands dominated by the native perennial grass, Hilaria jamesii (Torr.) Benth. and rarely where the natives Stipa hymenoides Roem. and Schult. and S. comata Trin. & Rupr. are dominant. This patchy invasion is likely due to differences in soil chemistry. Previous laboratory experiments investigated using soil amendments that would allow B. tectorum to germinate but would reduce B. tectorum emergence without affecting H. jamesii. For this study we selected the most successful treatments (CaCl2, MgCl2, NaCl and zeolite) from a previous laboratory study and applied them in the field in two different years at B. tectorum-dominated field sites. All amendments except the lowest level of CaCl2 and zeolite negatively affected B. tectorum emergence and/or biomass. No amendments negatively affected the biomass of H. jamesii but NaCl reduced emergence. Amendment effectiveness depended on year of application and the length of time since application. The medium concentration of zeolite had the strongest negative effect on B. tectorum with little effect on H. jamesii. We conducted a laboratory experiment to determine why zeolite was effective and found it released large amounts of Na+, adsorbed Ca2+, and increased Zn2+, Fe2+, Mn2+, Cu2+, exchangeable Mg2+, exchangeable K, and NH 4+ in the soil. Our results suggest several possible amendments to control B. tectorum. However, variability in effectiveness due to abiotic factors such as precipitation and soil type must be accounted for when establishing management plans. ?? Springer 2006.

  11. Sloshing Gas in the Core of the Most Luminous Galaxy Cluster RXJ1347.5-1145

    NASA Technical Reports Server (NTRS)

    Johnson, Ryan E.; Zuhone, John; Jones, Christine; Forman, William R.; Markevitvh, Maxim

    2011-01-01

    We present new constraints on the merger history of the most X-ray luminous cluster of galaxies, RXJ1347.5-1145, based on its unique multiwavelength morphology. Our X-ray analysis confirms the core gas is undergoing "sloshing" resulting from a prior, large scale, gravitational perturbation. In combination with extensive multiwavelength observations, the sloshing gas points to the primary and secondary clusters having had at least two prior strong gravitational interactions. The evidence supports a model in which the secondary subcluster with mass M=4.8+/-2.4x10(exp 14) solar Mass has previously (> or approx.0.6 Gyr ago) passed by the primary cluster, and has now returned for a subsequent crossing where the subcluster's gas has been completely stripped from its dark matter halo. RXJ1347 is a prime example of how core gas sloshing may be used to constrain the merger histories of galaxy clusters through multiwavelength analyses.

  12. Sloshing Gas in the Core of the Most Luminous Galaxy Cluster RXJ1347.5-1145

    NASA Technical Reports Server (NTRS)

    Markevitch, Maxim; Giacintucci, S.; Dallacasa, D.; Venturi, T.; Brunetti, G.; Cassano, R.; Athreya, R. M.; Johnson, Ryan E.; Zuhone, John; Jones, Christine; Forman, William R.

    2011-01-01

    We present new constraints on the merger history of the most X-ray luminous cluster of galaxies, RXJ1347.5-1145, based its unique multiwavelength morphology. Our X-ray analysis confirms the core gas is undergoing "sloshing" resulting from a prior, large scale, gravitational perturbation. In combination with extensive multiwavelength observations, the sloshing gas points to the primary and secondary clusters having had at least two prior strong gravitational interactions. The evidence supports a model in which the secondary subcluster with mass M=4.8+/-2.4 x 10(exp 14) Stellar Mass has previously (> or approx.=0.6 Gyr ago) passed by the primary cluster, and has now returned for a subsequent crossing where the subcluster's gas has been completely stripped from its dark matter halo. RXJ1347 is a prime example of how core gas sloshing may be used to constrain the merger histories of galaxy clusters through multiwavelength analyses.

  13. Transonic Aerodynamic Loading Characteristics of a Wing-Body-Tail Combination Having a 52.5 deg. Sweptback Wing of Aspect Ratio 3 With Conical Wing Camber and Body Indentation for a Design Mach Number of Square Root of 2

    NASA Technical Reports Server (NTRS)

    Cassetti, Marlowe D.; Re, Richard J.; Igoe, William B.

    1961-01-01

    An investigation has been made of the effects of conical wing camber and body indentation according to the supersonic area rule on the aerodynamic wing loading characteristics of a wing-body-tail configuration at transonic speeds. The wing aspect ratio was 3, taper ratio was 0.1, and quarter-chord-line sweepback was 52.5 deg. with 3-percent-thick airfoil sections. The tests were conducted in the Langley 16-foot transonic tunnel at Mach numbers from 0.80 to 1.05 and at angles of attack from 0 deg. to 14 deg., with Reynolds numbers based on mean aerodynamic chord varying from 7 x 10(exp 6) to 8 x 10(exp 6). Conical camber delayed wing-tip stall and reduced the severity of the accompanying longitudinal instability but did not appreciably affect the spanwise load distribution at angles of attack below tip stall. Body indentation reduced the transonic chordwise center-of-pressure travel from about 8 percent to 5 percent of the mean aerodynamic chord.

  14. Properties Data for Adhesion and Surface Chemistry of Aluminum: Sapphire-Aluminum, Single-Crystal Couple

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa; Pohlchuck, Bobby; Whitle, Neville C.; Hector, Louis G., Jr.; Adams, Jim

    1998-01-01

    An investigation was conducted to examine the adhesion and surface chemistry of single-crystal aluminum in contact with single-crystal sapphire (alumina). Pull-off force (adhesion) measurements were conducted under loads of 0. I to I mN in a vacuum of 10(exp -1) to 10(exp -9) Pa (approx. 10(exp -10) to 10(exp -11) torr) at room temperature. An Auger electron spectroscopy analyzer incorporated directly into an adhesion-measuring vacuum system was primarily used to define the chemical nature of the surfaces before and after adhesion measurements. The surfaces were cleaned by argon ion sputtering. With a clean aluminum-clean -sapphire couple the mean value and standard deviation of pull-off forces required to separate the surfaces were 3015 and 298 micro-N, respectively. With a contaminated aluminum-clean sapphire couple these values were 231 and 241 micro-N. The presence of a contaminant film on the aluminum surface reduced adhesion by a factor of 13. Therefore, surfaces cleanliness, particularly aluminum cleanliness, played an important role in the adhesion of the aluminum-sapphire couples. Pressures on the order of 10(exp -8) to 10(exp -9) Pa (approx. 10(exp -10) to 10(exp -11) torr) maintained a clean aluminum surface for only a short time (less then 1 hr) but maintained a clean sapphire surface, once it was achieved, for a much longer time.

  15. Petrological constraints on the recycling of mafic crystal mushes, magma ascent and intrusion of braided sills in the Torres del Paine mafic complex (Patagonia)

    NASA Astrophysics Data System (ADS)

    Leuthold, Julien; Müntener, Othmar; Baumgartner, Lukas; Putlitz, Benita

    2014-05-01

    Cumulate and crystal mush disruption and reactivation are difficult to recognise in coarse grained shallow plutonic rocks. Mafic minerals included in hornblende and zoned plagioclase provide snapshots of early crystallization and cumulate formation, but are difficult to interpret in terms of the dynamics of magma ascent and possible links between silicic and mafic rock emplacement. We will present the field relations, the microtextures and the mineral chemistry of the Miocene mafic sill complex of the Torres del Paine intrusive complex (Patagonia, Chile) and its sub-vertical feeder-zone. The mafic sill complex was built up by a succession of braided sills of shoshonitic and high-K calc-alkaline porphyritic hornblende-gabbro and fine grained monzodioritic sills. The mafic units were over-accreted over 41±11 ka, underplating the overlying granite. Local diapiric structures and felsic magma accumulation between sills indicate limited separation of intercumulus liquid from the mafic sills. Anhedral hornblende cores, with olivine + clinopyroxene ± plagioclase ± apatite inclusions, crystallized at temperatures >900°C and pressures of ~300 to ~500 MPa. The corresponding rims and monzodiorite matrix crystallized at <830°C, ~70 MPa. This abrupt compositional variation suggests stability and instability of hornblende during mafic roots recycling and subsequent decompression. The near lack of intercumulus crystals in the sub-vertical feeder zone layered gabbronorite and pyroxene-hornblende gabbronorite stocks testifies that melt is more efficiently extracted than in sills, resulting in a cumulate signature in the feeding system. The emplacement age of the sill complex topmost granitic unit is identical, within uncertainties, to the feeder zone mafic cumulates. Granitic liquids formed by AFC processes and were extracted at high temperature (T>950°C) from the middle crust reservoir to the emplacement level. We show that hornblende-plagioclase thermobarometry is a useful

  16. Patterns and correlates of self-reported racial discrimination among Australian Aboriginal and Torres Strait Islander adults, 2008–09: analysis of national survey data

    PubMed Central

    2013-01-01

    Background There is now considerable evidence that racism is a pernicious and enduring social problem with a wide range of detrimental outcomes for individuals, communities and societies. Although indigenous people worldwide are subjected to high levels of racism, there is a paucity of population-based, quantitative data about the factors associated with their reporting of racial discrimination, about the settings in which such discrimination takes place, and about the frequency with which it is experienced. Such information is essential in efforts to reduce both exposure to racism among indigenous people and the harms associated with such exposure. Methods Weighted data on self-reported racial discrimination from over 7,000 Indigenous Australian adults participating in the 2008–09 National Aboriginal and Torres Strait Islander Survey, a nationally representative survey conducted by the Australian Bureau of Statistics, were analysed by socioeconomic, demographic and cultural factors. Results More than one in four respondents (27%) reported experiencing racial discrimination in the past year. Racial discrimination was most commonly reported in public (41% of those reporting any racial discrimination), legal (40%) and work (30%) settings. Among those reporting any racial discrimination, about 40% experienced this discrimination most or all of the time (as opposed to a little or some of the time) in at least one setting. Reporting of racial discrimination peaked in the 35–44 year age group and then declined. Higher reporting of racial discrimination was associated with removal from family, low trust, unemployment, having a university degree, and indicators of cultural identity and participation. Lower reporting of racial discrimination was associated with home ownership, remote residence and having relatively few Indigenous friends. Conclusions These data indicate that racial discrimination is commonly experienced across a wide variety of settings, with public

  17. Fitting Vibrational Energy Parameters to Falloff Experiments: CH3 + CH3 + He (0.6-2 Torr 200-298 K)

    NASA Technical Reports Server (NTRS)

    Tardy, Dwight C.; Cody, Regina J.; Payne, Walter A.; Thorn, R. Peyton; Nesbitt, Fred L.; Iannone, Mark A.; Stief, Louis J.; Vondrak, Richard R. (Technical Monitor)

    2001-01-01

    There are many reported experiments and theoretical calculations for the combination of methyl free radicals diluted in a non-reactive 'deactivator. At high pressure the ethane (C2H6) combination product is the sole product; with decreasing pressure the chemically activated C2H6 will decompose. The falloff in the observed rate coefficient is the result of the competition between collisional stabilization of the chemically activated CA and unimolecular decomposition. The dependence of the rate coefficient on pressure, temperature and collision properties is complex and can not be calculated from first principles. The understanding of this system is not only of fundamental importance but is relevant to the recent detection of methyl free radicals in the atmospheres of Saturn - and Neptune. The temperatures of these outer planet atmospheres are in the 140-200 K region with total pressures (predominately H2 and He) less than 0.2 Torr. Experimentally determined rate coefficients have been reported for this reaction at T = 296-906 K and T = 200-408 K mostly with argon as the deactivator. At T = 200 K only the high pressure rate coefficient has been determined. Complete falloff curves over a wide temperature range (200-1600 K) with a variety of weak collider models used to simulate argon as the deactivator have also been reported by Klippenstein and Harding (KH). More recently we have reported the experimental rate coefficients in the falloff region with helium as the deactivator at 200 and 298 K. In this paper we have used the calculated falloff curves reported by KH for argon to determine the average energy transferred per collision for helium in our recently reported experiments. Collision rates were converted using Lennard Jones parameters; the temperature dependence of this conversion factor is noted. The helium experiments were consistent with a down of approximately 100 cm (exp-1); the temperature dependence was slight. The magnitude of down and

  18. Soil amendment effects on the exotic annual grass Bromus tectorum L. and facilitation of its growth by the native perennial grass Hilaria jamesii (Torr.) Benth

    USGS Publications Warehouse

    Belnap, J.; Sherrod, S.K.

    2009-01-01

    Greenhouse experiments were undertaken to identify soil factors that curtail growth of the exotic annual grass Bromus tectorum L. (cheatgrass) without significantly inhibiting growth of native perennial grasses (here represented by Hilaria jamesii [Torr.] Benth). We grew B. tectorum and H. jamesii alone (monoculture pots) and together (combination pots) in soil treatments that manipulated levels of soil phosphorus, potassium, and sodium. Hilaria jamesii showed no decline when its aboveground biomass in any of the applied treatments was compared to the control in either the monoculture or combination pots. Monoculture pots of B. tectorum showed a decline in aboveground biomass with the addition of Na2HPO4 and K2HPO4. Interestingly, in pots where H. jamesii was present, the negative effect of these treatments was ameliorated. Whereas the presence of B. tectorum generally decreased the aboveground biomass of H. jamesii (comparing aboveground biomass in monoculture versus combination pots), the presence of H. jamesii resulted in an enhancement of B. tectorum aboveground biomass by up to 900%. We hypothesize that B. tectorum was able to obtain resources from H. jamesii, an action that benefited B. tectorum while generally harming H. jamesii. Possible ways resources may be gained by B. tectorum from native perennial grasses include (1) B. tectorum is protected from salt stress by native plants or associated soil biota; (2) when B. tectorum is grown with H. jamesii, the native soil biota is altered in a way that favors B. tectorum growth, including B. tectorum tapping into the mycorrhizal network of native plants and obtaining resources from them; (3) B. tectorum can take advantage of root exudates from native plants, including water and nutrients released by natives via hydraulic redistribution; and (4) B. tectorum is able to utilize some combination of the above mechanisms. In summary, land managers may find adding soil treatments can temporarily suppress B. tectorum

  19. Arcjet system integration development

    NASA Astrophysics Data System (ADS)

    Zafran, Sidney

    1994-03-01

    Compatibility between an arcjet propulsion system and a communications satellite was verified by testing a Government-furnished, 1.4 kW hydrazine arcjet system with the FLTSATCOM qualification model satellite in a 9.1-meter (30-foot) diameter thermal-vacuum test chamber. Background pressure was maintained at 10(exp -5) torr during arcjet operation by cryopumping the thruster exhaust with an array of 5 K liquid helium cooled panels. Power for the arcjet system was obtained from the FLTSATCOM battery simulator. Spacecraft telemetry was monitored during each thruster firing period. No changes in telemetry data attributable to arcjet operation were detected in any of the tests. Electromagnetic compatibility data obtained included radiated emission measurements, conducted emission measurements, and cable coupling measurements. Significant noise was observed at lower frequencies. Above 500 MHz, radiated emissions were generally within limits, indicating that communication links at S-band and higher frequencies will not be affected. Other test data taken with a diagnostic array of calorimeters, radiometers, witness plates, and a residual gas analyzer evidenced compatible operation, and added to the data base for arcjet system integration. Two test series were conducted. The first series only included the arcjet and diagnostic array operating at approximately 0.1 torr background pressure. The second series added the qualification model spacecraft, a solar panel, and the helium cryopanels. Tests were conducted at 0.1 torr and 10(exp-5) torr. The arcjet thruster was canted 20 degrees relative to the solar panel axis, typical of the configuration used for stationkeeping thrusters on geosynchronous communications satellites.

  20. Arcjet system integration development

    NASA Technical Reports Server (NTRS)

    Zafran, Sidney

    1994-01-01

    Compatibility between an arcjet propulsion system and a communications satellite was verified by testing a Government-furnished, 1.4 kW hydrazine arcjet system with the FLTSATCOM qualification model satellite in a 9.1-meter (30-foot) diameter thermal-vacuum test chamber. Background pressure was maintained at 10(exp -5) torr during arcjet operation by cryopumping the thruster exhaust with an array of 5 K liquid helium cooled panels. Power for the arcjet system was obtained from the FLTSATCOM battery simulator. Spacecraft telemetry was monitored during each thruster firing period. No changes in telemetry data attributable to arcjet operation were detected in any of the tests. Electromagnetic compatibility data obtained included radiated emission measurements, conducted emission measurements, and cable coupling measurements. Significant noise was observed at lower frequencies. Above 500 MHz, radiated emissions were generally within limits, indicating that communication links at S-band and higher frequencies will not be affected. Other test data taken with a diagnostic array of calorimeters, radiometers, witness plates, and a residual gas analyzer evidenced compatible operation, and added to the data base for arcjet system integration. Two test series were conducted. The first series only included the arcjet and diagnostic array operating at approximately 0.1 torr background pressure. The second series added the qualification model spacecraft, a solar panel, and the helium cryopanels. Tests were conducted at 0.1 torr and 10(exp-5) torr. The arcjet thruster was canted 20 degrees relative to the solar panel axis, typical of the configuration used for stationkeeping thrusters on geosynchronous communications satellites.

  1. Investigation of a Light Gas Helicon Plasma Source for the VASIMR Space Propulsion System

    NASA Technical Reports Server (NTRS)

    Squire, J. P.; Chang-Diaz, F. R.; Jacobson, V. T.; Glover, T. W.; Baity, F. W.; Carter, M. D.; Goulding, R. H.; Bengtson, R. D.; Bering, E. A., III

    2003-01-01

    An efficient plasma source producing a high-density (approx.10(exp 19/cu m) light gas (e.g. H, D, or He) flowing plasma with a high degree of ionization is a critical component of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) concept. We are developing an antenna to apply ICRF power near the fundamental ion cyclotron resonance to further accelerate the plasma ions to velocities appropriate for space propulsion applications. The high degree of ionization and a low vacuum background pressure are important to eliminate the problem of radial losses due to charge exchange. We have performed parametric (e.g. gas flow, power (0.5 - 3 kW), magnetic field , frequency (25 and 50 MHz)) studies of a helicon operating with gas (H2 D2, He, N2 and Ar) injected at one end with a high magnetic mirror downstream of the antenna. We have explored operation with a cusp and a mirror field upstream. Plasma flows into a low background vacuum (<10(exp -4) torr) at velocities higher than the ion sound speed. High densities (approx. 10(exp 19/cu m) have been achieved at the location where ICRF will be applied, just downstream of the magnetic mirror.

  2. Confirmation of a Steep Luminosity Function for Ly alpha Emitters at z 5.7: a Major Component of Reionization

    NASA Technical Reports Server (NTRS)

    Dressler, Alan; Henry, Alaina L.; Martin, Crystal L.; Sawicki, Marcin; McCarthy, Patrick; Villaneuva, Edward

    2014-01-01

    We report the first direct and robust measurement of the faint-end slope of the Ly-alpha emitter (LAE) luminosity function at z = 5.7. Candidate LAEs from a low-spectral-resolution blind search with IMACS on Magellan- Baade were targeted at higher resolution to distinguish high redshift LAEs from foreground galaxies. All but 2 of our 42 single-emission-line systems are fainter than F = 2.0×10(exp-17) ergs s(exp-1) cm(exp-2), making these the faintest emission-lines observed for a z = 5.7 sample with known completeness, an essential property for determining the faint end slope of the LAE luminosity function. We find 13 LAEs as compared to 29 foreground galaxies, in very good agreement with the modeled foreground counts predicted in Dressler et al. (2011a) that had been used to estimate a faint-end slope of alpha = -2.0 for the LAE luminosity function. A 32% LAE fraction, LAE/(LAE+foreground) within the flux interval F = 2-20 × 10(exp-18) ergs s(exp-1) cm(exp-2) constrains the faint end slope of the luminosity function to -1.95 greater than alpha greater than -2.35 (1 delta). We show how this steep LF should provide, to the limit of our observations, more than 20% of the flux necessary to maintain ionization at z = 5.7, with a factor-of-ten extrapolation in flux reaching more than 55%. We suggest that this bodes well for a comparable contribution by similar, low-mass star forming galaxies at higher-redshift - within the reionization epoch at z greater than approximately 7, only 250 Myr earlier - and that such systems provide a substantial, if not dominant, contribution to the late-stage reionization of the IGM.

  3. The National Aeronautics and Space Administration's Gilmore Load Cell Machine: Load Cell Calibrations to 2.22 x 10(exp 7) Newtons

    NASA Technical Reports Server (NTRS)

    Haynes, Michael W.

    2000-01-01

    Designed in 1964 and erected in 1966, the mission of the Gilmore Load Cell Machine was to provide highly accurate calibrations for large capacity load cells in support of NASA's Apollo Program. Still in use today, the Gilmore Machine is a national treasure with no equal.

  4. Initial Results from a Search for Lunar Radio Emission from Interactions of >= 10(exp 19) eV Neutrinos and Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Gorham, P. W.; Liewer, K. M.; Naudet, C. J.

    2000-01-01

    Using the NASA Goldstone 70m antenna DSS 14 both singly and in coincidence with the 34 m antenna DSS 13 (21.7 km to the southeast), we have acquired approximately 12 hrs of livetime in a search for predicted pulsed radio emission from extremely-high energy cascades induced by neutrinos or cosmic rays in the lunar regolith. In about 4 hrs of single antenna observations, we reduced our sensitivity to impulsive terrestrial interference to a negligible level by use of a veto afforded by the unique capability of DSS 14. In the 8 hrs of dual-antenna observations, terrestrial interference is eliminated as a background. In both observing modes the thermal noise floor limits the sensitivity. We detected no events above statistical background. We report here initial limits based on these data which begin to constrain several predictions of the flux of EHE neutrinos.

  5. A Giant Radio Halo in a Low-Mass Sz-selected Galaxy Cluster: ACT-CLJ0256.5+0006

    NASA Technical Reports Server (NTRS)

    Knowles, Kendra; Intema, H. T.; Baker, A. J.; Bharadwaj, V.; Bond, J. R.; Cress, C.; Gupta, N.; Hajian, A.; Hilton, M.; Hincks, A. D.; Hlozek, R.; Hughes, J. P.; Lindner, R. R.; Marriage, T. A.; Menanteau, F.; Moodley, K.; Niemack, M. D.; Reese, E. D.; Sievers, J.; Sifon, C.; Srianand, R.; Wollack, Edward J.

    2016-01-01

    We present the detection of a giant radio halo (GRH) in the Sunyaev-Zel'dovich (SZ)- selected merging galaxy cluster ACT-CL J0256.5+ 0006 (z = 0.363), observed with the Giant Metrewave Radio Telescope at 325 and 610 MHz. We find this cluster to host a faint (S610 = 5.6 +/- 1.4mJy) radio halo with an angular extent of 2.6 arcmin, corresponding to 0.8 Mpc at the cluster redshift, qualifying it as a GRH. J0256 is one of the lowest mass systems, M500, SZ = (5.0 +/- 1.2) × 10(exp14) M, found to host a GRH. We measure the GRH at lower significance at 325 MHz (S325 = 10.3 +/- 5.3mJy), obtaining a spectral index measurement of a610 325 = 1.0+ 0.7 - 0.9. This result is consistent with the mean spectral index of the population of typical radio haloes, alpha = 1.2 +/- 0.2. Adopting the latter value, we determine a 1.4 GHz radio power of P1.4 GHz = (1.0 +/- 0.3) × 10(exp 24)W/Hz, placing this cluster within the scatter of known scaling relations. Various lines of evidence, including the intracluster medium morphology, suggest that ACT-CL J0256.5+ 0006 is composed of two subclusters. We determine a merger mass ratio of 7:4, and a line-of-sight velocity difference of v? = 1880 +/- 210 km/s. We construct a simple merger model to infer relevant time-scales in the merger. From its location on the P1.4GHz-LX scaling relation, we infer that we observe ACT-CL J0256.5+ 0006 just before first core crossing.

  6. Thermal decomposition of explosives studied by chemiluminescence techniques. [Hexanitrostilbene, 2-(5-cyanotetrazolato)pentaumine cobalt perchlorate

    SciTech Connect

    Volltrauer, H.N.

    1982-01-01

    The thermal decomposition rates of pentaerythritol-tetranitrate, PETN; hexanitrostilbene, HNS; and 2-(5-cyanotetrazolato)pentaamminecobalt(III) perchlorate, CP, have been investigated using a chemiluminescence NO/NO/sub x/ analyzer to detect decomposition products from these substances in real time. For PETN two samples were tested over the 50 to 105/sup 0/C temperature range. The results are interpreted in terms of two NO/sub x/ evolution mechanisms; one appears to be desorption of NO/sub x/ and the other is due to decomposition for which the rate coefficients are 1.3 x 10/sup 14/ exp(-37800/RT)s/sup -1/ and 8.3 x 10/sup 14/ exp(-40800/RT)s/sup -1/ for the two samples. Over the 160 to 250/sup 0/C temperature range the rate coefficient describing the NO evolution from HNSI is k(T) = 3 x 10/sup 10/ exp(-42000/RT)s/sup -1/. For two HNSII samples k(T) = 1.6 x 10/sup 10/ exp(-42000/RT)s/sup -1/. Much larger NO evolution rates than predicted by the k(T) (as well as NO/sub 2/ evolution) are obtained with fresh samples. Increasing NO evolution rates were measured at fixed temperatures above 250/sup 0/C. The k(T) for NH/sub 3/ evolution from CP is k(T) = 5.2 x 10/sup 8/ exp(-32000/RT)s/sup -1/ over the 90 to 185/sup 0/C temperature range. Increasing NH/sub 3/ evolution rates were measured at fixed temperatures of 185/sup 0/C or above. The units of k(T) are moles NO/sub x/ (or NH/sub 3/) evolved per mole of substance investigated per second.

  7. File Specification for GEOS-5 FP-IT (Forward Processing for Instrument Teams)

    NASA Technical Reports Server (NTRS)

    Lucchesi, R.

    2013-01-01

    The GEOS-5 FP-IT Atmospheric Data Assimilation System (GEOS-5 ADAS) uses an analysis developed jointly with NOAA's National Centers for Environmental Prediction (NCEP), which allows the Global Modeling and Assimilation Office (GMAO) to take advantage of the developments at NCEP and the Joint Center for Satellite Data Assimilation (JCSDA). The GEOS-5 AGCM uses the finite-volume dynamics (Lin, 2004) integrated with various physics packages (e.g, Bacmeister et al., 2006), under the Earth System Modeling Framework (ESMF) including the Catchment Land Surface Model (CLSM) (e.g., Koster et al., 2000). The GSI analysis is a three-dimensional variational (3DVar) analysis applied in grid-point space to facilitate the implementation of anisotropic, inhomogeneous covariances (e.g., Wu et al., 2002; Derber et al., 2003). The GSI implementation for GEOS-5 FP-IT incorporates a set of recursive filters that produce approximately Gaussian smoothing kernels and isotropic correlation functions. The GEOS-5 ADAS is documented in Rienecker et al. (2008). More recent updates to the model are presented in Molod et al. (2011). The GEOS-5 system actively assimilates roughly 2 × 10(exp 6) observations for each analysis, including about 7.5 × 10(exp 5) AIRS radiance data. The input stream is roughly twice this volume, but because of the large volume, the data are thinned commensurate with the analysis grid to reduce the computational burden. Data are also rejected from the analysis through quality control procedures designed to detect, for example, the presence of cloud. To minimize the spurious periodic perturbations of the analysis, GEOS-5 FP-IT uses the Incremental Analysis Update (IAU) technique developed by Bloom et al. (1996). More details of this procedure are given in Appendix A. The analysis is performed at a horizontal resolution of 0.625-degree longitude by 0.5-degree latitude and at 72 levels, extending to 0.01 hPa. All products are generated at the native resolution of the

  8. Preparation and Dielectric Measurements of the Rare Earth Green Phases R2BaCuO(5-x) (R = Y, Sm, Gd, Dy, Ho, Er, Yb)

    NASA Technical Reports Server (NTRS)

    Gonzalez-Titman, Carlos

    1994-01-01

    It has been demonstrated that R2BaCuO(5-x) (R = Y, Sm, Gd, Dy, Ho, Er, Yb) does not undergo significant densification unless the sintering temperatures are near the incongruent melting point or the sintering times are long. Good quality powders of Y2BaCuO(5-x) have been synthesized by using oxide raw materials or precursors such as acetates and nitrates. The acetates- and the nitrates-derived yttrium green phase resulted in finer particle sizes, acceptable dielectric properties and lower melting temperatures than those processed via oxide raw materials. The hot pressing technique has been employed to produce a dense R2BaCuO(5-x) (R=Y,Gd) substrate with satisfactory dielectric properties. Reactivity to reducing conditions, i.e. graphite die, limited the optimization of the properties. A high sensitivity to the annealing atmosphere has been demonstrated in Y2BaCuO,.,,. Oxygen treatment at 950 OC has been shown to improve the dielectric properties while treatment in nitrogen, at the same temperature, degraded desirable properties. A high sensitivity to the annealing atmosphere has been demonstrated in Y2BaCuO(5-x). Oxygen treatment at 950 C has been shown to improve the dielectric properties while treatment in nitrogen, at the same temperature, degraded desirable properties. The dielectric constants of the rare earth green phases R2BaCuO(5-x) were found to be low. Relaxation peaks were detected at low temperatures (T less than 150 K) and at high temperatures (150 less than T greater than 420 K). The dielectric losses and conductivities at 77 K were measured to be in the range of 10(exp -4) and 10(exp -12) (Omega-cm)(exp -1), respectively. Many parameters were found to exhibit dependencies on the rare earth cation sizes.

  9. Getting it Right: study protocol to determine the diagnostic accuracy of a culturally-specific measure to screen for depression in Aboriginal and/or Torres Strait Islander people

    PubMed Central

    Hackett, Maree L; Farnbach, Sara; Glozier, Nick; Skinner, Timothy; Teixeira-Pinto, Armando; Askew, Deborah; Gee, Graham; Cass, Alan; Brown, Alex

    2016-01-01

    Introduction A freely available, culturally valid depression screening tool is required for use by primary care services across Australia to screen for depression in Aboriginal and/or Torres Strait Islander populations. This is the protocol for a study aiming to determine the validity, sensitivity and specificity of the culturally adapted 9-item Patient Health Questionnaire (aPHQ-9). Methods and analysis Cross-sectional validation study. A total of 500 people who self-identify as Aboriginal and/or Torres Strait Islander, are ≥18 years of age, attending 1 of 10 primary healthcare services or service events across Australia and able to communicate sufficiently to answer study questions will be recruited. All participants will complete the aPHQ-9 and the criterion standard MINI International Neuropsychiatric Interview (MINI) 6.0.0. The primary outcome is the criterion validity of the aPHQ-9. Process outcomes related to acceptability and feasibility of the aPHQ-9 will be analysed only if the measure is found to be valid. Ethics and dissemination Lead ethical approval was obtained jointly from the University of Sydney Human Research Ethics Committee (project 2014/361) and the Aboriginal Health and Medical Research Council of New South Wales (project 1044/14). Results will be disseminated via the usual scientific forums, including peer-reviewed publications and presentations at international conferences following presentation to, discussion with and approval by participating primary healthcare service staff and community. Trial registration number ACTRN12614000705684. PMID:27927669

  10. Kinetics and Mechanism of the Reaction of Hydoxyl Radicals with Acetonitrile under Atmospheric Conditions

    NASA Technical Reports Server (NTRS)

    Hynes, A. J.; Wine, P. H.

    1997-01-01

    The pulsed laser photolysis-pulsed laser induced fluorescence technique has been employed to determine absolute rate coefficients for the reaction OH + CH3CN (1) and its isotopic variants, OH + CD3CN (2), OD + CH3CN (3), and OD + CD3CN (4). Reactions 1 and 2 were studied as a function of pressure and temperature in N2, N2/O2, and He buffer gases. In the absence of O2 all four reactions displayed well-behaved kinetics with exponential OH decays and pseudo-first rate constants which were proportional to substrate concentration. Data obtained in N2 over the range 50-700 Torr at 298 K are consistent with k(sub 1), showing a small pressure dependence. The Arrhenius expression obtained by averaging data at all pressures in k(sub 1)(T) = (1.1(sup +0.5)/(sub -0.3)) x 10(exp -12) exp[(-1130 +/- 90)/T] cu cm /(molecule s). The kinetics of reaction 2 are found to be pressure dependent with k(sub 2) (298 K) increasing from (1.21 +/- 0.12) x 10(exp -14) to (2.16 +/- 0.11) x 10(exp -14) cm(exp 3)/ (molecule s) over the pressure range 50-700 Torr of N2 at 298 K. Data at pressures greater than 600 Torr give k(sub 2)(T) = (9.4((sup +13.4)(sub -5.0))) x 10(exp -13) exp[(-1180 +/- 250)/T] cu cm/(molecule s). The rates of reactions 3 and 4 are found to be independent of pressure over the range 50-700 Torr of N2 with 298 K rate coefficient given by k(sub 3) =(3.18 +/- 0.40) x 10(exp -14) cu cm/(molecule s) and k(sub 4) = (2.25 +/-0.28) x 10(exp -14) cu cm/(molecule s). In the presence of O2 each reaction shows complex (non-pseudo-first-order) kinetic behavior and/or an apparent decrease in the observed rate constant with increasing [O2], indicating the presence of significant OH or OD regeneration. Observation of regeneration of OH in (2) and OD in (3) is indicative of a reaction channel which proceeds via addition followed by reaction of the adduct, or one of its decomposition products, with O2. The observed OH and OD decay profiles have been modeled by using a simple mechanistic

  11. Laser Induced Fluorescence Measurements in a Hall Thruster Plume as a Function of Background Pressure

    NASA Technical Reports Server (NTRS)

    Spektor, R.; Tighe, W. G.; Kamhawi, H.

    2016-01-01

    A set of Laser Induced Fluorescence (LIF) measurements in the near-field region of the NASA- 173M Hall thruster plume is presented at four background pressure conditions varying from 9.4 x 10(exp -6) torr to 3.3 x 10(exp -5) torr. The xenon ion velocity distribution function was measured simultaneously along the axial and radial directions. An ultimate exhaust velocity of 19.6+/-0.25 km/s achieved at a distance of 20 mm was measured, and that value was not sensitive to pressure. On the other hand, the ion axial velocity at the thruster exit was strongly influenced by pressure, indicating that the accelerating electric field moved inward with increased pressure. The shift in electric field corresponded to an increase in measured thrust. Pressure had a minor effect on the radial component of ion velocity, mainly affecting ions exiting close to the channel inner wall. At that radial location the radial component of ion velocity was approximately 1000 m/s greater at the lowest pressure than at the highest pressure. A reduction of the inner magnet coil current by 0.6 A resulted in a lower axial ion velocity at the channel exit while the radial component of ion velocity at the channel inner wall location increased by 1300 m/s, and at the channel outer wall location the radial ion velocity remained unaffected. The ultimate exhaust velocity was not significantly affected by the inner magnet current.

  12. Erosion Results of the MISSE 7 Polymers Experiment and Zenith Polymers Experiment After 1.5 Years of Space Exposure

    NASA Technical Reports Server (NTRS)

    De Groh, Kim K.; Banks, Bruce A.; Yi, Grace T.; Haloua, Athena; Imka, Emily C.; Mitchell, Gianna G.; Asmar, Olivia C.; Leneghan, Halle A.; Sechkar, Edward A.

    2016-01-01

    Polymers and other oxidizable materials on the exterior of spacecraft in the low Earth orbit (LEO) space environment can be eroded due to reaction with atomic oxygen (AO). Therefore, in order to design durable spacecraft it is important to know the LEO AO erosion yield (E(sub y), volume loss per incident oxygen atom) of materials susceptible to AO reaction. Two spaceflight experiments, the Polymers Experiment and the Zenith Polymers Experiment, were developed to determine the AO E(sub y) of various polymers flown in ram, wake or zenith orientations in LEO. These experiments were flown as part of the Materials International Space Station Experiment 7 (MISSE 7) mission for 1.5 years on the exterior of the International Space Station (ISS). The experiments included Kapton H(TradeMark) witness samples for AO fluence determination in ram and zenith orientations. The Polymers Experiment also included samples to determine whether AO erosion of high and low ash containing polymers is dependent on fluence. This paper provides an overview of the MISSE 7 mission, a description of the flight experiments with details on the polymers flown, the characterization techniques used, the AO fluence for each exposure orientation, and the LEO E(sub y) results. The E(sub y) values ranged from 7.99x10(exp -28)cu cm/atom for TiO2/Al2O3 coated Teflon(TradeMark) fluorinated ethylene propylene (FEP) flown in the ram orientation to 1.22x10(exp -23cu cm/atom for polyvinyl alcohol (PVOH) flown in the zenith orientation. The E(sub y) of similar samples flown in different orientations has been compared to help determine solar exposure and associated heating effects on AO erosion. The E(sub y) data from these ISS spaceflight experiments provides valuable information for LEO spacecraft design purposes.

  13. A Novel Tungsten-Nickel Alloy Ohmic Contact to SiC at 900 C

    NASA Technical Reports Server (NTRS)

    Okojie, Robert S.; Evans, Laura J.; Lukco, Dorothy; Morris, Joseph P.

    2010-01-01

    A novel tungsten-nickel ohmic contact metallization on 4H-SiC and 6H-SiC capable of surviving temperatures as high as 900 C is reported. Preliminary results revealed the following: 1) ohmic contact on n-type 4H-SiC having net doping levels (Nd's) of 1.4 and 2 x 10(exp 19) per cubic centimeter, with specific contact resistances rhosNd's of 7.69 x 10(exp -4) and 5.81 x 10(exp -4) OMEGA (raised dot) square centimeters, respectively, after rapid thermal annealing (RTA), and 5.9 x 10(exp -3) and 2.51 x 10(exp -4) OMEGA (raised dot) square centimeters, respectively, after subsequent soak at 900 C for 1 h in argon, and 2) ohmic contact on n- and p-type 6H-SiC having Nd > 2 x 10(exp 19) and Na > 1 x 10(exp 20) per cubic centimeter, with rhosNd = 5 x 10(exp -5) and rhosNa = 2 X 10(exp -4) OMEGA (raised dot) square centimeter, respectively, after RTA, and rhosNd = 2.5 x 10 (exp -5) and rhosNa = 1.5 x 10(exp -4) OMEGA (raised dot) square centimeter after subsequent treatment at 900 C for 1 h in argon, respectively.

  14. Recovery Temperature, Transition, and Heat Transfer Measurements at Mach 5

    NASA Technical Reports Server (NTRS)

    Brinich, Paul F.

    1961-01-01

    Schlieren, recovery temperature, and heat-transfer measurements were made on a hollow cylinder and a cone with axes alined parallel to the stream. Both the cone and cylinder were equipped with various bluntnesses, and the tests covered a Reynolds number range up to 20 x 10(exp 6) at a free-stream Mach number of 4.95 and wall to free-stream temperature ratios from 1.8 to 5.2 (adiabatic). A substantial transition delay due to bluntness was found for both the cylinder and the cone. For the present tests (Mach 4.95), transition was delayed by a factor of 3 on the cylinder and about 2 on the cone, these delays being somewhat larger than those observed in earlier tests at Mach 3.1. Heat-transfer tests on the cylinder showed only slight effects of wall temperature level on transition location; this is to be contrasted to the large transition delays observed on conical-type bodies at low surface temperatures at Mach 3.1. The schlieren and the peak-recovery-temperature methods of detecting transition were compared with the heat-transfer results. The comparison showed that the first two methods identified a transition point which occurred just beyond the end of the laminar run as seen in the heat-transfer data.

  15. The Orbits of Meteorites from Natural Thermoluminescence. Attachment 5

    NASA Technical Reports Server (NTRS)

    Benoit, P. H.; Sears, D. W. G.

    1997-01-01

    The natural thermoluminescence (TL) of meteorites reflects their irradiation and thermal histories. Virtually all ordinary chondrites have been irradiated long enough to reach saturation natural TL levels, and thus natural TL levels in these meteorites are determined largely by thermal history. The primary heat source for most meteorites is the Sun, and thus natural TL levels are determined primarily by the closest approach to the Sun, i.e., perihelion. By converting natural TL levels to perihelia, using an assumed albedo typical of meteoroid bodies, it is found that most ordinary chondrites had perihelia of 0.85 to 1.0 AU prior to reaching Earth. This range is similar to that calculated from meteor and fireball observations. All common classes of ordinary chondrites exhibit similar perihelia distributions; however, H and LL chondrites that fell in the local morning differ in their natural TL distribution from those that fell in the local afternoon or evening. This is consistent with earlier suggestions that time of fall reflects orbital distribution. The data also suggest that the orbits of some of the H chondrites cluster and may have come from a debris 'stream' of meteoroids. If meteorites can exist in "orbital groups," significant changes in the types and number of meteorites reaching Earth could occur on the less than 10(exp 5)-year time scale.

  16. Aerogel Beads as Cryogenic Thermal Insulation System

    NASA Technical Reports Server (NTRS)

    Fesmire, J. E.; Augustynowicz, S. D.; Rouanet, S.; Thompson, Karen (Technical Monitor)

    2001-01-01

    An investigation of the use of aerogel beads as thermal insulation for cryogenic applications was conducted at the Cryogenics Test Laboratory of NASA Kennedy Space Center. Steady-state liquid nitrogen boiloff methods were used to characterize the thermal performance of aerogel beads in comparison with conventional insulation products such as perlite powder and multilayer insulation (MLI). Aerogel beads produced by Cabot Corporation have a bulk density below 100 kilograms per cubic meter (kg/cubic m) and a mean particle diameter of 1 millimeter (mm). The apparent thermal conductivity values of the bulk material have been determined under steady-state conditions at boundary temperatures of approximately 293 and 77 kelvin (K) and at various cold vacuum pressures (CVP). Vacuum levels ranged from 10(exp -5) torr to 760 torr. All test articles were made in a cylindrical configuration with a typical insulation thickness of 25 mm. Temperature profiles through the thickness of the test specimens were also measured. The results showed the performance of the aerogel beads was significantly better than the conventional materials in both soft-vacuum (1 to 10 torr) and no-vacuum (760 torr) ranges. Opacified aerogel beads performed better than perlite powder under high-vacuum conditions. Further studies for material optimization and system application are in progress.

  17. Preliminary Heat-Transfer Measurements on a Hypersonic Glide Configuration Having 79.5 degree Sweepback and 45 degree Dihedral at a Mach Number of 4.95

    NASA Technical Reports Server (NTRS)

    Stainback, Calvin

    1960-01-01

    An experimental investigation was conducted to evaluate the heat-transfer characteristics of a hypersonic glide configuration having 79.5 deg of sweepback (measured in the plane of the leading edges) and 45 of dihedral. The tests were conducted at a nominal Mach number of 4.95 and a stagnation temperature of 400 F. The test-section unit Reynolds number was varied from 1.95 x 10(exp 6) to 12.24 x 10(exp 6) per foot. The results indicated that the laminar-flow heat-transfer rate to the lower surface of the model decreased as the distance from the ridge line increased except for thermocouples located near the semispan at an angle of attack of 00 with respect to the plane of the leading edges. The heat-transfer distribution (local heating rate relative to the ridge-line heating rate) was similar to the theoretical heat-transfer distribution for a two-dimensional blunt body, if the ridge line was assumed to be the stagnation line, and could be predicted by this theory provided a modified Newtonian pressure distribution was used. Except in the vicinity of the apex, the ridge-line heat-transfer rate could also be predicted from two-dimensional blunt-body heat-transfer theory provided it was assumed that the stagnation-line heat-transfer rate varied as the cosine of the effective sweep (sine of the angle of attack of the ridge line). The heat-transfer level on the lower surface and the nondimensional heat-transfer distribution around the body on the lower surface were in qualitative agreement with the results of a geometric study of highly swept delta wings with large positive dihedrals made in reference 1.

  18. File Specification for GEOS-5 FP (Forward Processing)

    NASA Technical Reports Server (NTRS)

    Lucchesi, R.

    2013-01-01

    The GEOS-5 FP Atmospheric Data Assimilation System (GEOS-5 ADAS) uses an analysis developed jointly with NOAA's National Centers for Environmental Prediction (NCEP), which allows the Global Modeling and Assimilation Office (GMAO) to take advantage of the developments at NCEP and the Joint Center for Satellite Data Assimilation (JCSDA). The GEOS-5 AGCM uses the finite-volume dynamics (Lin, 2004) integrated with various physics packages (e.g, Bacmeister et al., 2006), under the Earth System Modeling Framework (ESMF) including the Catchment Land Surface Model (CLSM) (e.g., Koster et al., 2000). The GSI analysis is a three-dimensional variational (3DVar) analysis applied in grid-point space to facilitate the implementation of anisotropic, inhomogeneous covariances (e.g., Wu et al., 2002; Derber et al., 2003). The GSI implementation for GEOS-5 FP incorporates a set of recursive filters that produce approximately Gaussian smoothing kernels and isotropic correlation functions. The GEOS-5 ADAS is documented in Rienecker et al. (2008). More recent updates to the model are presented in Molod et al. (2011). The GEOS-5 system actively assimilates roughly 2 × 10(exp 6) observations for each analysis, including about 7.5 × 10(exp 5) AIRS radiance data. The input stream is roughly twice this volume, but because of the large volume, the data are thinned commensurate with the analysis grid to reduce the computational burden. Data are also rejected from the analysis through quality control procedures designed to detect, for example, the presence of cloud. To minimize the spurious periodic perturbations of the analysis, GEOS-5 FP uses the Incremental Analysis Update (IAU) technique developed by Bloom et al. (1996). More details of this procedure are given in Appendix A. The assimilation is performed at a horizontal resolution of 0.3125-degree longitude by 0.25- degree latitude and at 72 levels, extending to 0.01 hPa. All products are generated at the native resolution of the

  19. How Dead are Dead Galaxies? Mid-Infrared Fluxes of Quiescent Galaxies at Redshift 0.3< Z< 2.5: Implications for Star Formation Rates and Dust Heating

    NASA Technical Reports Server (NTRS)

    Fumagalli, Mattia; Labbe, Ivo; Patel, Shannon G.; Franx, Marijn; vanDokkum, Pieter; Brammer, Gabriel; DaCunha, Elisabete; FoersterSchreiber, Natascha M.; Kriek, Mariska; Quadri, Ryan; Rix, Hans-Walter; Wake, David; Whitaker, Katherine E.; Lundgren, Britt; Marchesini, Danilo; Maseda, Michael; Momcheva, Ivelina; Nelson, Erica; Pacifici, Camilla; Skelton, Rosalind E.

    2013-01-01

    We investigate star formation rates of quiescent galaxies at high redshift (0.3 < z < 2.5) using 3D-HST WFC3 grism spectroscopy and Spitzer mid-infrared data. We select quiescent galaxies on the basis of the widely used UVJ color-color criteria. Spectral energy distribution fitting (rest frame optical and near-IR) indicates very low star formation rates for quiescent galaxies (sSFR approx. 10(exp -12)/yr. However, SED fitting can miss star formation if it is hidden behind high dust obscuration and ionizing radiation is re-emitted in the mid-infrared. It is therefore fundamental to measure the dust-obscured SFRs with a mid-IR indicator. We stack the MIPS-24 micron images of quiescent objects in five redshift bins centered on z = 0.5, 0.9, 1.2, 1.7, 2.2 and perform aperture photometry. Including direct 24 micron detections, we find sSFR approx. 10(exp -11.9) × (1 + z)(sup 4)/yr. These values are higher than those indicated by SED fitting, but at each redshift they are 20-40 times lower than those of typical star forming galaxies. The true SFRs of quiescent galaxies might be even lower, as we show that the mid-IR fluxes can be due to processes unrelated to ongoing star formation, such as cirrus dust heated by old stellar populations and circumstellar dust. Our measurements show that star formation quenching is very efficient at every redshift. The measured SFR values are at z > 1.5 marginally consistent with the ones expected from gas recycling (assuming that mass loss from evolved stars refuels star formation) and well above that at lower redshifts.

  20. Chemical and mechanical interactions of interstitials in V-5%Cr-5%Ti

    SciTech Connect

    DeVan, J.H.; DiStefano, J.R.; Hendricks, J.W.

    1994-09-01

    Gas-metal reaction studies of V-5Cr-5Ti were conducted to determine the kinetics of reactions with H{sub 2} and O{sub 2}, respectively, at 400-500{degrees}C. Reaction rates were determined through weight change measurements and chemical analysis, and effects on mechanical properties were evaluated by room temperature tensile tests. Exposure to hydrogen at pressures between 10{sup {minus}4} to 10{sup {minus}2} torr lowered the tensile ductility in the case of coarse-grained specimens but had little effect on finer-grained specimens. Similarly oxygen uptake at 500{degrees}C, at concentrations as low as 200 ppm (by weight), significantly lowered the ductility of the coarser-grained but not the finer-grained material.

  1. NuSTAR Detection of the Blazar B2 1023+25 at Redshift 5.3

    NASA Technical Reports Server (NTRS)

    Sbarrato, T.; Tagliaferri, G.; Ghisellini, G.; Perri, M.; Puccetti, S.; Balokovic, M.; Nardini, M.; Stern, D.; Boggs, S. E.; Brandt, W. N.; Christensen, F. E.; Giommi, P.; Greiner, J.; Hailey, C. J.; Harrison, F. A.; Hovatta, T.; Madejski, G. M.; Rau, A.; Schady, P.; Sudilovsky, V.; Urry, C. M.; Zhang, William W.

    2013-01-01

    B2 1023+25 is an extremely radio-loud quasar at zeta = 5.3 that was first identified as a likely high-redshift blazar candidate in the SDSS+FIRST quasar catalog. Here, we use the Nuclear Spectroscopic Telescope Array (NuSTAR) to investigate its non-thermal jet emission, whose high-energy component we detected in the hard X-ray energy band. The X-ray flux is approximately 5.5 × 10 (exp -14) erg cm(exp -2) s(exp -1) (5-10 keV) and the photon spectral index is Gamma(x) approx. =1.3-1.6. Modeling the full spectral energy distribution, we find that the jet is oriented close to the line of sight, with a viewing angle of approximately 3deg, and has significant Doppler boosting, with a large bulk Lorentz factor approximately 13, which confirms the identification of B2 1023+25 as a blazar. B2 1023+25 is the first object at redshift larger than 5 detected by NuSTAR, demonstrating the ability of NuSTAR to investigate the early X-ray universe and to study extremely active supermassive black holes located at very high redshift.

  2. Performance Evaluation of the SPT-140

    NASA Technical Reports Server (NTRS)

    Manzella, David; Sarmiento, Charles; Sankovic, John; Haag, Tom

    1997-01-01

    As part of an on-going cooperative program with industry, an engineering model SPT-140 Hall thruster, which may be suitable for orbit insertion and station-keeping of geosynchronous communication satellites, was evaluated with respect to thrust and radiated electromagnetic interference at the NASA Lewis Research Center. Performance measurements were made using a laboratory model propellant feed system and commercial power supplies. The engine was operated in a space simulation chamber capable of providing background pressures of 4 x 10(exp -6) Torr or less during thruster operation. Thrust was measured at input powers ranging from 1.5 to 5 kilowatts with two different output filter configurations. The broadband electromagnetic emission spectra generated by the engine was also measured for a range of frequencies from 0.01 to 18,000 Mhz. These results are compared to the noise threshold of the measurement system and MIL-STD-461C where appropriate.

  3. A model for heterogeneous chemical processes on the surfaces of ice and nitric acid trihydrate particles

    NASA Technical Reports Server (NTRS)

    Tabazadeh, Azadeh; Turco, Richard P.

    1993-01-01

    The study presents a model that incorporates the physics and physical chemistry of ice surfaces relevant to polar stratospheric clouds. Surface concentrations of H2O, HCl, HOCl, ClONO2, and N2O5 on ice and nitric acid trihydrate (NAT) crystals are computed, and surface reaction rates and reaction probabilities (sticking coefficients) are determined. For gas pressures of about 10 exp -7 torr and temperatures in the range of 180-200 K, HCl completely coats ice and water-rich NAT surfaces, while HOCl, ClOHO2, and N2O5 may cover 0.01-1 percent of these surfaces. The energy parameters are used to calculate surface temperatures such as adsorption and desorption constants, surface coverages, reaction rate coefficients, surface diffusion coefficients, and reaction probabilities for various species and chemical interactions on ice and NAT surfaces. Implications for chemical processing on polar stratospheric clouds are discussed.

  4. A model for heterogeneous chemical processes on the surfaces of ice and nitric acid trihydrate particles

    NASA Astrophysics Data System (ADS)

    Tabazadeh, Azadeh; Turco, Richard P.

    1993-07-01

    The study presents a model that incorporates the physics and physical chemistry of ice surfaces relevant to polar stratospheric clouds. Surface concentrations of H2O, HCl, HOCl, ClONO2, and N2O5 on ice and nitric acid trihydrate (NAT) crystals are computed, and surface reaction rates and reaction probabilities (sticking coefficients) are determined. For gas pressures of about 10 exp -7 torr and temperatures in the range of 180-200 K, HCl completely coats ice and water-rich NAT surfaces, while HOCl, ClOHO2, and N2O5 may cover 0.01-1 percent of these surfaces. The energy parameters are used to calculate surface temperatures such as adsorption and desorption constants, surface coverages, reaction rate coefficients, surface diffusion coefficients, and reaction probabilities for various species and chemical interactions on ice and NAT surfaces. Implications for chemical processing on polar stratospheric clouds are discussed.

  5. The effect of 1 to 5 keV electrons on the reproductive integrity of microorganisms

    NASA Technical Reports Server (NTRS)

    Barengoltz, J. B.; Brady, J.

    1977-01-01

    Microorganisms were exposed to simulated space environment in order to assess the effect of electrons in the energy range 1 to 5 keV on their colony-forming ability. The test system consisted of an electron gun and power supply, a dosimetry subsystem, and a vacuum subsystem. The system was capable of current densities ranging from 0.1 nA/sq cm to 5 micro A/sq cm on a 25 sq on target and an ultimate vacuum of 0.0006 N/sq m (0.000004 torr). The results of the experimental program show a significant reduction in microbial reproductive integrity.

  6. Thermal dissociation and relaxation in vinyl fluoride, 1,1-difluoroethane and 1,3,5-triazine

    NASA Astrophysics Data System (ADS)

    Xu, Hui

    This study reports measurements of the thermal dissociation of 1,1-difluoroethane in the shock tube. The experiments employ laser schlieren measurements of rate for the dominant HF elimination using 10% 1,1-difluoroethane in Kr over 1500--2000 K and 43 < P < 424 torr. The product vinyl then dissociates affecting the late density gradient. We include a laser schlieren study (1717--2332 K, 75 < P < 482 torr in 10% and 4% vinyl fluoride in Kr) of this dissociation. This latter work also includes a set of experiments using shock-tube time-of-flight mass-spectrometry (4% vinyl fluoride in neon, 1500--1980 K, 500 < P < 1300 torr), which confirm the theoretical expectation that the only reaction in vinyl fluoride is HF elimination. The relaxation experiments (1--20% C2H3F in Kr, 415--1975 K, 5 < P < 50 torr, and 2% and 5% C2H4F2 in Kr, 700--1350 K, 6 < P < 22 torr) exhibit very rapid relaxation, and incubation delays should be negligible in dissociation. A RRKM model of dissociation in 1,1-difluoroethane based on a G3B3 calculation of barrier and other properties fits the experiments but requires a very large down of 1600cm-1 . Dissociation of vinyl fluoride has two parallel HF eliminations both three-center and four-center with nearly equal barriers. An RRKM fit to the observed falloff again requires an unusually large down and the experiments actually support a slightly reduced barrier. Both 1,3,5-triazine and pyrazine relax extremely rapidly with energy transfer in a few collisions, any incubation delay can be confidently discounted in dissociation. 1,3,5-triazine dissociation experiments show fall-off with a clear pressure dependence. The three body product dissociation mechanism models this dissociation perfectly. Experimental data agree well with an RRKM calculation using a down of 1200cm-1 and a barrier E0 = 84.66 kcal/mol. Dyakov et al. suggested lower barrier of E0 = 81 kcal/mole. The new RRKM calculation using this barrier seems a better

  7. The Effect of Stress and TiC Coated Balls on Lifetime of a Perfluoropolyalkylether Using a Vacuum Rolling Contact Tribometer

    NASA Technical Reports Server (NTRS)

    Jones, William R., Jr.; Pepper, Stephen; Jansen, Mark J.; Nguyen, QuynhGiao; Wheeler, Donald R.; Schroeer, Achim

    2000-01-01

    A vacuum spiral orbit tribometer (SOT) was used to determine the relative lifetimes of a branched perfluoropolyalkylether (PFPAE) on 440 C stainless steel. The effect of varying the mean Hertzian stress (0.75, 1.0, 1.5 and 2.0 GPa) and the use of TiC coated balls on lubricant lifetime was studied. Other conditions included: approx. 100 rpm, approx. 50 micro-g of lubricant, an initial vacuum level of less than 1.3 x 10(exp -6) Pa (less than 10 x 10(exp -8) Torr), and room temperature (approx. 23 C). Increasing the mean Hertzian stress from 0.75 to 2.0 GPa results in an exponential decrease in lubricant lifetime for both material combinations. However, substituting a TiC ball for the 440 C ball quadrupled lifetime at low stress levels (0.75 and 1.0 GPa) and doubled life at higher stresses (1.5 and 2.0 GPa), The reduced reactivity of the TiC surface with the PFPAE lubricant is considered to be the reason for this enhancement. Decreasing lifetime with increasing stress levels correlated well with energy dissipation calculations.

  8. HST Observations of Star Formation in Interacting Galaxies: NGC 4194, the "Medusa"

    NASA Technical Reports Server (NTRS)

    Weistrop, D.; Eggers, D.; Nelson, C. H.; Kaiser, M. E.

    2001-01-01

    Ultraviolet and visible imaging of the blue compact galaxy NGC4194 was obtained to survey the star-forming knots in the center of this galaxy. Photometry and image analysis were performed on these regions. Comparison with evolutionary tracks indicates many of the knots are reddened with a typical E(B-V)approx.0.3. The knot ages range from 10(exp 6-10(exp 8)years. Some of the knots may have masses 3-5x10(exp 5) solar mass. The FUV fluxes correspond to the flux from 60-3.8x10(exp 3) O5V stars.

  9. Post-Flight Analysis of Selected Fluorocarbon and Other Thin Film Polymer Specimens Flown on MISSE-5

    NASA Technical Reports Server (NTRS)

    DeGroh, Kim; Finckenor, Miria; Minton, Tim; Brunsvold, Amy; Pippin, Gary

    2007-01-01

    Twenty thin film specimens were flown on M1SSE-5 as a cooperative effort between several organizations. This presentation will report results of initial inspections and post-flight measurements of the optical properties and recession of these materials due to the approx.13 month exposure period on the exterior of the International Space Station. These specimens were located on the "anti-solar" side of the MISSE-5 container and received a low number of Equivalent Sun Hours of solar UV exposure. Profilometry and/or ATF measurements will be conducted to determine thickness changes and atomic oxygen-induced recession rates Six of the specimens were covered with thin Kapton films, 0.1 and 0.3 mil in thickness. The 0.1 mil Kapton was almost completely eroded, suggesting that the atomic oxygen fluence is <8 x 10(exp 19) atoms/sq cm, similar to levels experienced during Space Shuttle materials experiments in the 1980's and 1990's. A comparison of results from MISSE-5 and Space Shuttle experiments will be included for those materials common to both the short and long-term exposures.

  10. Photodissociation of Peroxynitric Acid in the Near-IR

    NASA Technical Reports Server (NTRS)

    Roehl, Coleen M.; Nizkorodov, Sergey A.; Zhang, Hui; Blake, Geoffrey A.; Wennberg, Paul O.

    2002-01-01

    Temperature-dependent near-IR photodissociation spectra were obtained for several vibrational overtone transitions of peroxynitric acid (HNO4) with a tunable OPO photolysis/OH laser-induced-fluorescence system. Band-integrated photodissociation cross-sections (definity integral of sigma(sub diss)), determined relative to that for the 3nu(sub 1), OH stretching overtone, were measured for three dissociative bands. Assuming unit quantum efficiency for photodissociation of 3nu(sub 1), we find 2nu(sub 1) + nu(sub 3)(8242/cm) = (1.21 x 10(exp -20) (independent of temperature), 2nu(sub 1) (6900/cm) = 4.09 x 10(exp 18) * e(sup (-826,5/T)) (295 K greater than T greater than 224 K), and nu(sub 1) + 2nu(sub 3) (6252/cm) = 1.87 x 10(exp -19) * e(sup (- 1410.7/T)) (278 K greater than T greater than 240 K) sq cm/molecule cm. The photodissociation cross-sections are independent of pressure over the range 2 to 40 Torr. Temperature-dependent quantum yields (phi) for these transitions were obtained using integrated absorption cross-sections (definity integral of sigma(sub abs)) of HNO4 overtone vibrations measured with a FTIR spectrometer. In the atmosphere, photodissociation in the infrared is dominated by excitation of the first overtone of the OH stretching vibration (2nu((sub 1)). Inclusion of all dissociative HNO4 overtone and combination transitions yields a daytime IR photolysis rate of approximately 1 x 10(esp -1)/s. This process significantly shortens the estimated lifetime of HNO4 in the upper troposphere and lower stratosphere.

  11. Sulfuric Acid Monohydrate: Formation and Heterogeneous Chemistry in the Stratosphere

    NASA Technical Reports Server (NTRS)

    Zhang, Renyi; Leu, Ming-Taun; Keyser, Leon F.

    1995-01-01

    We have investigated some thermodynamic properties (i.e., freezing/melting points) and heterogeneous chemistry of sulfuric acid monohydrate (SAM, H2SO4.H2O), using a fast flow reactor coupled to a quadrupole mass spectrometer. The freezing point observations of thin liquid sulfuric acid films show that for acid contents between 75 and 85 wt % the monohydrate crystallizes readily at temperatures between 220 and 240 K on a glass substrate. Once formed, SAM can be thermodynamically stable in the H2O partial pressure range of (1-4) x 10(exp -4) torr and in the temperature range of 220-240 K. For a constant H2O partial pressure, lowering the temperature causes SAM to melt when the temperature and water partial pressure conditions are out of its stability regime. The reaction probability measurements indicate that the hydrolysis of N2O5 is significantly suppressed owing to the formation of crystalline SAM: The reaction probability on water-rich SAM (with higher relative humidity, or RH) is of the order of 10(exp -3) at 210 K and decreases by more than an order of magnitude for the acid-rich form (with lower RH). The hydrolysis rate of ClONO2 on water-rich SAM is even smaller, of the order of 10(exp -4) at 195 K. These reported values on crystalline SAM are much smaller than those on liquid solutions. No enhancement of these reactions is observed in the presence of HCl vapor at the stratospheric concentrations. In addition, Brunauer, Emmett, and Teller analysis of gas adsorption isotherms and photomicrography have been performed to characterize the surface roughness and porosities of the SAM substrate. The results suggest the possible formation of SAM in some regions of the middle- or low-latitude stratosphere and, consequently, much slower heterogeneous reactions on the frozen aerosols.

  12. Kinetics and Thermochemistry of ClCO Formation from the Cl + CO Association Reaction

    NASA Technical Reports Server (NTRS)

    Nicovich, J. M.; Kreutter, K. D.; Wine, P. H.

    1997-01-01

    Laser flash photolysis of Cl2/CO/M mixtures (M = N2, CO, Ar, CO2) has been employed in conjunction with Cl((sup 2)P(sub J)) detection by time-resolved resonance fluorescence spectroscopy to investigate equilibration kinetics in the reactions Cl((sup 2)P(sub J)) + CO ClCO as a function of temperature (185-260 K) and pressure (14-200 Torr). The association and dissociation reactions are found to be in the low-pressure limit over the range of experimental conditions investigated. In N2 and/or CO buffer gases, the temperature dependences of the ClCO formation and dissociation reaction rate constants are described by the Arrhenius expressions k(sub 1) = (1.05 +/- 0.36) x 10(exp -34) exp[(810 +/- 70)/T] cm(exp 6)/molecules(exp 2).s and k(sub -1) = (4.1 +/- 3.1) x 10(exp -10) exp[(-2960 +/- 60)/T]cu cm/(molecule.s) (errors are 2 sigma). Second- and third-law analyses of the temperature dependence of the equilbrium constant (k/k-1) lead to the following thermodynamic parameters for the association reaction: Delta-H(sub 298) = -7.7 +/- 0.6 kcal/mol, Delta-H(sub 0) = -6.9 +/- 0.7 kcal/mol, Delta-S(sub 298) = -23.8 +/- 2.0 cal/mole.K, Delta-H(sub f,298)(ClCO) = 5.2 +/- 0.6 kcal/mol (errors are 2 sigma). The results repported in this study significantly reduce the uncertainties in all reported kinetic and thermodynamic parameters.

  13. Cable Bundle Wire Derating

    NASA Technical Reports Server (NTRS)

    Lundquist, Ray A.; Leidecker, Henning

    1999-01-01

    The allowable operating currents of electrical wiring when used in the space vacuum environment is predominantly determined by the maximum operating temperature of the wire insulation. For Kapton insulated wire this value is 200 degree C. Guidelines provided in the Goddard Space Flight Center (GSFC) Preferred Parts List (PPL) limit the operating current of wire within vacuum to ensure the maximum insulation temperature is not exceeded. For 20 AWG wire, these operating parameters are: (1) 3.7 amps per wire (2) bundle of 15 or more wires (3) 70 C environment (4) vacuum of 10(exp -5) torr or less To determine the behavior and temperature of electrical wire at different operating conditions, a thermal vacuum test was performed on a representative electrical harness of the Hubble Space Telescope (HST) power distribution system. This paper describes the test and the results.

  14. Amorphous to Amorphous Form Transitions of Water Ice and Astrophysical Implications

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Blake, David F.; Chang, Sherwood (Technical Monitor)

    1994-01-01

    We have combined Selected Area Electron Diffraction (SAED) and cryogenic techniques in an instrumental configuration that allows observing the structure of vapor deposited ice as it evolves during warmup. The ice is deposited in-situ inside an Hitachi H-500 H transmission electron microscope at a base pressure of 1-5 x 10(exp -7) torr on a thin amorphous carbon substrate at 15K or 86K and warmed up at a rate of 1-2 K/min. We find a progression of amorphous forms and well defined amorphous to amorphous transitions. Apart from the well known low-density form of ice, we confirm the presence of a high-density form and find a third amorphous form that coexists with cubic ice. We will report too on the amorphous to crystalline transition and the implications of these results for radical diffusion and gas retention observed in laboratory analog studies of interstellar and cometary ices.

  15. Experimental studies of an ECR plasma thruster

    NASA Technical Reports Server (NTRS)

    Kaufman, D. A.; Goodwin, D. G.; Sercel, J. C.

    1993-01-01

    The Electron Cyclotron Resonance (ECR) thruster is a proposed electrodeless space electric propulsion device with interesting and little understood physics. A laboratory ECR thruster was run in a vacuum tank at pressures in the 10 exp -5 torr range using 2.12 GHz microwave beam and Ar gas propellant. Movable diagnostic probes (a Faraday cup and a gridded energy analyzer) measured plasma characteristics as propellant gas flow rate and input microwave power level were varied. Ion energy and flux data were used to calculate I(sp), propulsive efficiency, and thrust. The ion flux profiles show an unexpected depression on the thruster axis for low tank pressures that disappears as the tank pressure increases. Ion energies decrease as the flow rate and pressure increase, but the microwave power level affects the energy only negligibly. The calculated propulsion parameters demonstrate that the efficiency of the laboratory device is low, and that tank pressure greatly changes the performance.

  16. Experimental studies of an ECR plasma thruster

    NASA Astrophysics Data System (ADS)

    Kaufman, D. A.; Goodwin, D. G.; Sercel, J. C.

    1993-06-01

    The Electron Cyclotron Resonance (ECR) thruster is a proposed electrodeless space electric propulsion device with interesting and little understood physics. A laboratory ECR thruster was run in a vacuum tank at pressures in the 10 exp -5 torr range using 2.12 GHz microwave beam and Ar gas propellant. Movable diagnostic probes (a Faraday cup and a gridded energy analyzer) measured plasma characteristics as propellant gas flow rate and input microwave power level were varied. Ion energy and flux data were used to calculate I(sp), propulsive efficiency, and thrust. The ion flux profiles show an unexpected depression on the thruster axis for low tank pressures that disappears as the tank pressure increases. Ion energies decrease as the flow rate and pressure increase, but the microwave power level affects the energy only negligibly. The calculated propulsion parameters demonstrate that the efficiency of the laboratory device is low, and that tank pressure greatly changes the performance.

  17. Cable Bundle Wire Derating

    NASA Technical Reports Server (NTRS)

    Lundquist, Ray A.; Leidecker, Henning

    1998-01-01

    The allowable operating currents of electrical wiring when used in the space vacuum environment is predominantly determined by the maximum operating temperature of the wire insulation. For Kapton insulated wire this value is 200 C. Guidelines provided in the Goddard Space Flight Center (GSFC) Preferred Parts List (PPL) limit the operating current of wire within vacuum to ensure the maximum insulation temperature is not exceeded. For 20 AWG wire, these operating parameters are: (1) 3.7 amps per wire; (2) bundle of 15 or more wires; (3) 70 C environment: and (4) vacuum of 10(exp -5) torr or less. To determine the behavior and temperature of electrical wire at different operating conditions, a thermal vacuum test was performed on a representative electrical harness of the Hubble Space Telescope (HST) power distribution system. This paper describes the test and the results.

  18. Chloryl nitrate - A novel product of the OClO + NO3 + M recombination

    NASA Technical Reports Server (NTRS)

    Friedl, Randall R.; Sander, Stanley P.; Yung, Yuk L.

    1992-01-01

    The products of the reaction of OClO with NO3 were investigated between 220 and 298 K using a flow reactor and infrared, visible, and ultraviolet analysis. At temperatures below 250 K new infrared and ultraviolet absorption features were observed and assigned to the novel compound chloryl nitrate (O2ClONO2). Additionally, ClO and NO2 were observed as reaction products, indicating the existence of a second reaction channel. O2ClONO2 formation predominates at temperatures below 230 K. The reaction rate constant at 220 K is estimated to be on the order of 10 exp -14 cu cm/molecule s in 1-5 Torr of helium. These observations suggest that O2ClONO2 may exist in the terrestrial stratosphere.

  19. Cable Bundle Wire Derating

    NASA Technical Reports Server (NTRS)

    Lundquist, Ray A.; Leidecker, Henning

    1998-01-01

    The allowable operating currents of electrical wiring when used in the space vacuum environment is predominantly determined by the maximum operating temperature of the wire insulation. For Kapton insulated wire this value is 200 C. Guidelines provided in the Goddard Space Flight Center (GSFC) Preferred Parts List (PPL) limit the operating current of wire within vacuum to ensure the maximum insulation temperature is not exceeded. For 20 AWG wire, these operating parameters are: 3.7 amps per wire, bundle of 15 or more wires, 70 C environment, and vacuum of 10(exp -5) torr or less. To determine the behavior and temperature of electrical wire at different operating conditions, a thermal vacuum test was performed on a representative electrical harness of the Hubble Space Telescope (HST) power distribution system. This paper describes the test and the results.

  20. Acoustic isolation vessel for measurement of the background noise in microphones

    NASA Technical Reports Server (NTRS)

    Ngo, Kim C. T.; Zuckerwar, Allan J.

    1993-01-01

    An acoustic isolation vessel has been developed to measure the background noise in microphones. The test microphone is installed in an inner vessel, which is suspended within an outer vessel, and the intervening air space is evacuated to a high vacuum. An analytical expression for the transmission coefficient is derived, based on a five-media model, and compared to experiment. At an isolation vacuum of 5 x 10 exp -6 Torr the experimental transmission coefficient was found to be lower than -155 dB at frequencies ranging from 40 to 1200 Hz. Measurements of the A-weighted noise levels of commercial condenser microphones of four different sizes show good agreement with published values.

  1. Vacancy defects in thin-film La{sub 0.5}Sr{sub 0.5}CoO{sub 3{minus}{delta}} observed by positron annihilation

    SciTech Connect

    Keeble, D.J.; Krishnan, A.; Friessnegg, T.; Nielsen, B.; Madhukar, S.; Aggarwal, S.; Ramesh, R.; Poindexter, E.H.

    1998-07-01

    Vacancy-related defects in laser ablated thin films of the conducting metal{endash}oxide La{sub 0.5}Sr{sub 0.5}CoO{sub 3{minus}{delta}} were detected using a variable-energy positron beam. The nonstoichiometry, {delta}, was altered by varying the oxygen partial pressure within the deposition chamber present during cooling. Conductivity measurements confirmed the change in oxygen content. Increased positron trapping at vacancy defects was observed with increasing nonstoichiometry. It is proposed that vacancy clusters were present in the film cooled in 10{sup {minus}5}thinspTorr oxygen. {copyright} {ital 1998 American Institute of Physics.}

  2. Radio Detections During Two State Transitions of the Intermediate-Mass Black Hole HLX-1

    NASA Technical Reports Server (NTRS)

    Webb, Natalie; Cseh, David; Lenc, Emil; Godet, Olivier; Barret, Didier; Corbel, Stephane; Farrell, Sean; Fender, Robert; Gehrels, Neil; Heywood, Ian

    2012-01-01

    Relativistic jets are streams of plasma moving at appreciable fractions of the speed of light. They have been observed from stellar-mass black holes (approx. 3 to 20 solar masses) as well as supermassive black holes (approx.. 10(exp 6) to 10(exp 9) Solar Mass) found in the centers of most galaxies. Jets should also be produced by intermediate-mass black holes (approx. 10(exp 2) to 10(exp 5) Solar Mass), although evidence for this third class of black hole has, until recently, been weak. We report the detection of transient radio emission at the location of the intermediate-mass black hole candidate ESO 243-49 HLX-1, which is consistent with a discrete jet ejection event. These observations also allow us to refine the mass estimate of the black hole to be between approx. 9 × 10(exp 3) Solar Mass and approx. 9 × 10(exp 4) Solar Mass.

  3. Properties of large area ErBa2Cu3O(7-x) thin films deposited by ionized cluster beams

    NASA Technical Reports Server (NTRS)

    Levenson, L. L.; Stan, Mark A.; Bhasin, Kul B.

    1991-01-01

    ErBa2Cu3O(7-x) films have been produced by simultaneous deposition of Er, Ba, and Cu from three ionized cluster beam (ICB) sources at acceleration voltages of 0.3 to 0.5 kV. Combining ozone oxidation with ICB deposition at 650 C eliminated any need of post annealing processing. The substrates were rotated at 10 rotations per minute during the deposition which took place at a rate of about 3 to 4 nm. Films with areas up to 70 mm in diameter have been made by ICB deposition. These films, 100 nm thick, were deposited on SrTiO3 (100) substrates at 650 C in a mixture of six percent O3 in O2 at a total pressure of 4 x 10(exp -4) Torr. They had T(sub c) ranging from 84.3 K to 86.8 K over a 70 mm diameter and J(sub c) above 10(exp 6) A/sq cm at 77 K. X ray diffraction measurements of the three samples showed preferential c-axis orientation normal to the substrate surface. Scanning electron micrographs (SEM) of the three samples also show some texture dependence on sample position. For the three samples, there is a correlation between SEM texture, full width at half-maximum of rocking curves and J(sub c) versus temperature curves.

  4. Carbon Nanotube-Based Digital Vacuum Electronics and Miniature Instrumentation for Space Exploration

    NASA Technical Reports Server (NTRS)

    Manohara, H.; Toda, R.; Lin, R. H.; Liao, A.; Mojarradi, M.

    2010-01-01

    JPL has developed high performance cold cathodes using arrays of carbon nanotube bundles that produce > 15 A/sq cm at applied fields of 5 to 8 V/micron without any beam focusing. They have exhibited robust operation in poor vacuums of 10(exp -6) to 10(exp -4) Torr- a typically achievable range inside hermetically sealed microcavities. Using these CNT cathodes JPL has developed miniature X-ray tubes capable of delivering sufficient photon flux at acceleration voltages of <20kV to perform definitive mineralogy on planetary surfaces; mass ionizers that offer two orders of magnitude power savings, and S/N ratio better by a factor of five over conventional ionizers. JPL has also developed a new class of programmable logic gates using CNT vacuum electronics potentially for Venus in situ missions and defense applications. These digital vacuum electronic devices are inherently high-temperature tolerant and radiation insensitive. Device design, fabrication and DC switching operation at temperatures up to 700 C are presented in this paper.

  5. Laboratory Experiments on Rotation of Micron Size Cosmic Dust Grains with Radiation

    NASA Technical Reports Server (NTRS)

    Abbas, M. M.; Craven, P. D.; Spann, J. F.; Tankosic, D.; LeClair, A.; Gallagher, D. L.; West, E.; Weingartner, J.; Witherow, W. K.

    2004-01-01

    The processes and mechanisms involved in the rotation and alignment of interstellar dust grains have been of great interest in astrophysics ever since the surprising discovery of the polarization of starlight more than half a century ago. Numerous theories, detailed mathematical models and numerical studies of grain rotation and alignment along the Galactic magnetic field have been presented in the literature. In particular, the subject of grain rotation and alignment by radiative torques has been shown to be of particular interest in recent years. However, despite many investigations, a satisfactory theoretical understanding of the processes involved in grain rotation and alignment has not been achieved. As there appears to be no experimental data available on this subject, we have carried out some unique experiments to illuminate the processes involved in rotation of dust grains in the interstellar medium. In this paper we present the results of some preliminary laboratory experiments on the rotation of individual micron/submicron size nonspherical dust grains levitated in an electrodynamic balance evacuated to pressures of approx. 10(exp -3) to 10(exp -5) torr. The particles are illuminated by laser light at 5320 A, and the grain rotation rates are obtained by analyzing the low frequency (approx. 0-100 kHz) signal of the scattered light detected by a photodiode detector. The rotation rates are compared with simple theoretical models to retrieve some basic rotational parameters. The results are examined in the light of the current theories of alignment.

  6. Laboratory Experiments on Rotation and Alignment of the Analogs of Interstellar Dust Grains by Radiation

    NASA Technical Reports Server (NTRS)

    Abbas, M. M.; Craven, P. D.; Spann, J. F.; Tankosic, D.; LeClair, A.; Gallagher, D. L.; West, E. A.; Weingartner, J. C.; Witherow, W. K.; Tielens, A. G. G. M.

    2004-01-01

    The processes and mechanisms involved in the rotation and alignment of interstellar dust grains have been of great interest in astrophysics ever since the surprising discovery of the polarization of starlight more than half a century ago. Numerous theories, detailed mathematical models and numerical studies of grain rotation and alignment with respect to the Galactic magnetic field have been presented in the literature. In particular, the subject of grain rotation and alignment by radiative torques has been shown to be of particular interest in recent years. However, despite many investigations, a satisfactory theoretical understanding of the processes involved in grain rotation and alignment has not been achieved. As there appears to be no experimental data available on this subject, we have carried out some unique experiments to illuminate the processes involved in rotation of dust grains in the interstellar medium. In this paper we present the results of some preliminary laboratory experiments on the rotation of individual micron/submicron size nonspherical dust grains levitated in an electrodynamic balance evacuated to pressures of approximately 10(exp -3) to 10(exp -5) torr. The particles are illuminated by laser light at 5320 Angstroms, and the grain rotation rates are obtained by analyzing the low frequency (approximately 0-100 kHz) signal of the scattered light detected by a photodiode detector. The rotation rates are compared with simple theoretical models to retrieve some basic rotational parameters. The results are examined in the light of the current theories of alignment.

  7. Laboratory Experiments on Rotation and Alignment of the Analogs of Interstellar Dust Grains by Radiation

    NASA Technical Reports Server (NTRS)

    Abbas, M. M.; Craven, P. D.; Spann, J. F.; Tankosic, D.; LeClair, A.; Gallagher, D. L.; West, E. A.; Weingartner, J. C.; Witherow, W. K.; Tielens, A. G. G. M.

    2004-01-01

    The processes and mechanisms involved in the rotation and alignment of interstellar dust grains have been of great interest in astrophysics ever since the surprising discovery of the polarization of starlight more than half a century ago. Numerous theories, detailed mathematical models, and numerical studies of grain rotation and alignment with respect to the Galactic magnetic field have been presented in the literature. In particular, the subject of grain rotation and alignment by radiative torques has been shown to be of particular interest in recent years. However, despite many investigations, a satisfactory theoretical understanding of the processes involved in subject, we have carried out some unique experiments to illuminate the processes involved in the rotation of dust grains in the interstellar medium. In this paper we present the results of some preliminary laboratory experiments on the rotation of individual micron/submicron-sized, nonspherical dust grains levitated in an electrodynamic balance evacuated to pressures of approximately 10(exp -3) to 10(exp -5) torr. The particles are illuminated by laser light at 5320 A, and the grain rotation rates are obtained by analyzing the low-frequency (approximately 0 - 100 kHz) signal of the scattered light detected by a photodiode detector. The rotation rates are compared with simple theoretical models to retrieve some basic rotational parameters. The results are examined in light of the current theories of alignment.

  8. Piezoelectrically Actuated Shutter for High Vacuum

    NASA Technical Reports Server (NTRS)

    Thompson, Robert; Klose, Gerhard

    2003-01-01

    A piezoelectrically actuated shutter is undergoing development for use in experiments on laser cooling of atoms. The shutter is required to be compatible with ultrahigh vacuum [pressure of 10(exp -9) torr (.1.3 x 10(exp -7) Pa) or less] and to be capable of performing reliably in the vacuum for at least one year. In operation, the shutter would enable the collection and launch of successive samples of cold atoms and would enable the interrogation of the immediately preceding sample while preventing disturbance of the atoms of that sample by light from the collection region. A major constraint is imposed on the design and operation of the shutter by a requirement that it not generate a magnetic field large enough to perturb an atomic clock. An electromagnetically actuated shutter could satisfy all requirements except this one. Hence, it was decided to use piezoelectric instead of electromagnetic actuation. The shutter (see figure) includes two commercial piezoelectrically driven flexure stages that produce a travel of 0.5 mm. Levers mechanically amplify the travel to the required level of 1 cm. Problems that remained to be addressed at the time of reporting the information for this article included lifetime testing and correction of a tendency for shutter blades to bounce open.

  9. Kinetics of the Cl(2)P(J)) + CH4 Reaction: Effects of Secondary Chemistry Below 300 K

    NASA Technical Reports Server (NTRS)

    Wang, J. J.; Keyser, Leon F.

    2000-01-01

    Absolute rate data for the Cl(2)P(J) + CH4 yields HCl + CH3 reaction have been obtained from 218 to 298 K by using the discharge-flow resonance fluorescence technique at I Torr total pressure. The result at 298 K is (10.1 +/- 0.6) x 10(exp -14) cu cm/molecule/s. The temperature dependence in Arrhenius form is (6.5 +/- 0.9 ) x 10(exp -12) exp[(-1235 +/- 34 )/T]. The errors given are one standard deviation; overall experimental error is estimated at +/- 15%. Because of the relatively large disagreement among earlier measurements at low temperatures, the results were examined for possible effects of non-Boltzmann spin distribution and vibrational excitation of CH4, secondary chemistry of CH3 radicals, and impurities in the CH4 source. There was no significant change in the observed rate constant when an efficient spin quencher, CF4, was added and estimates indicate that vibrational partitioning in CH4 should be at the ambient reactor temperature before the start of the reaction. The results were also independent of the source of Cl atoms (microwave discharge or thermal decomposition of Cl2) and whether CH4 was purified in-situ. However, the observed rate constant did depend on initial Cl atom concentrations and to a lesser extent on CH4 concentrations. Numerical simulations were used to assess the importance of secondary chemistry over a range of reactant concentrations

  10. Spectroscopic studies of model polar stratospheric cloud films

    NASA Technical Reports Server (NTRS)

    Tolbert, Margaret A.; Koehler, Birgit G.; Middlebrook, Ann M.

    1993-01-01

    Fourier transform infrared (FTIR) spectroscopy has been used to study nitric-acid/ice films representative of type I polar stratospheric clouds (PSCs). These studies reveal that in addition to amorphous nitric acid/ice mixtures, there are three stable stoichiometric hydrates of nitric acid: nitric-acid monohydrate (NAM), dihydrate (NAD), and trihydrate (NAT). We also observe two distinct crystalline forms of the trihydrate, which we denote alpha- and beta-NAT. These two forms appear to differ in their concentration of crystalline defects, but not in their chemical composition. In addition to probing the composition of type I PSCs, we have also used FTIR spectroscopy to study the interaction of HCl with model PSC films. In this work we find that for HCl pressures in the range 10 exp -5 to 10 exp -7 Torr, HCl is taken up by ice at 155 K to form a thin layer of HCl.6H2O. At 193 K, the uptake of HCl by ice was consistent with less than or equal to monolayer coverage. Uptake of HCl by alpha and beta-NAT at 175 K was also consistent with less than or equal to monolayer coverage.

  11. Accelerators (5/5)

    ScienceCinema

    None

    2016-07-12

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  12. Tracking performance and cycle slipping in the all-digital symbol synchronizer loop of the block 5 receiver

    NASA Technical Reports Server (NTRS)

    Aung, M.

    1992-01-01

    Computer simulated noise performance of the symbol synchronizer loop (SSL) in the Block 5 receiver is compared with the theoretical noise performance. Good agreement is seen at the higher loop SNR's (SNR(sub L)'s), with gradual degradation as the SNR(sub L) is decreased. For the different cases simulated, cycle slipping is observed (within the simulation time of 10(exp 4) seconds) at SNR(sub L)'s below different thresholds, ranging from 6 to 8.5 dB, comparable to that of a classical phase-locked loop. An important point, however, is that to achieve the desired loop SNR above the seemingly low threshold to avoid cycle slipping, a large data-to-loop-noise power ratio, P(sub D)/(N(sub 0)B(sub L)), is necessary (at least 13 dB larger than the desired SNR(sub L) in the optimum case and larger otherwise). This is due to the large squaring loss (greater than or equal to 13 dB) inherent in the SSL. For the special case of symbol rates approximately equaling the loop update rate, a more accurate equivalent model accounting for an extra loop update period delay (characteristic of the SSL phase detector design) is derived. This model results in a more accurate estimation of the noise-equivalent bandwidth of the loop.

  13. Operating characteristics of the Russian D-55 thruster with anode layer

    NASA Technical Reports Server (NTRS)

    Sankovic, John M.; Haag, Thomas W.; Manzella, David H.

    1994-01-01

    Performance measurements of a Russian engineering-model Thruster with Anode Layer (TAL) were obtained as part of a program to evaluate the operating characteristics of Russian Hall-thruster technology. The TAL model D-55 was designed to operate in the 1-2 kW power range on xenon. When received, the thruster had undergone only a few hours of acceptance testing by the manufacturer. Direct thrust measurements were obtained at a background pressure of 0.0003 Pa (2 x 10(exp -6) torr) at power levels ranging from 0.3 kW to 2.1 kW. At the nominal power level of 1.3 kW, a specific impulse level of 1600 s with a corresponding efficiency of 0.48 was attained. At all flow rates tested, the efficiency increased linearly with specific impulse until a maximum was reached, and then the efficiency leveled off. Increasing the anode flow rate shifted the efficiency upward, reaching 0.50 at 1850 s specific impulse. The thruster was equipped with inner and outer electromagnets which were isolated from the discharge and from each other. Variation of the magnetic field, obtained by changing the currents through the magnets, had little effect on performance, except at current levels below 70 percent of nominal. For a given operating condition, the performance was slightly affected by facility pressure. As the pressure was increased by a factor of thirty to 0.008 Pa (6 x 10(exp -5) torr), the current steadily increased by 4 percent, and the thrust increased by 2 percent. Performance comparisons were made with the Stationary Plasma Thruster, and the efficiency and specific impulse values were similar at power levels ranging from 0.9 kW to 1.5 kW. Endurance testing was not performed, and comparisons of lifetime were not made.

  14. Kinetic study of IO radical with RO2 (R = CH(3), C2H5, and CF3) using cavity ring-down spectroscopy.

    PubMed

    Enami, Shinichi; Yamanaka, Takashi; Hashimoto, Satoshi; Kawasaki, Masahiro; Nakano, Yukio; Ishiwata, Takashi

    2006-08-17

    The reactions of iodine monoxide radical, IO, with alkyl peroxide radicals, RO(2) (R = CH(3), C(2)H(5), and CF(3)), have been studied using cavity ring-down spectroscopy. The rate constant of the reaction of IO with CH(3)O(2) was determined to be (7.0 +/- 3.0) x 10(-11) cm(3) molecule(-1) s(-1) at 298 K and 100 Torr of N(2) diluent. The quoted uncertainty is two standard deviations. No significant pressure dependence of the rate constant was observed at 30-130 Torr total pressure of N(2) diluent. The temperature dependence of the rate constants was also studied at 213-298 K. The upper limit of the branching ratio of OIO radical formation from IO + CH(3)O(2) was estimated to be <0.1. The reaction rate constants of IO + C(2)H(5)O(2) and IO + CF(3)O(2) were determined to be (14 +/- 6) x 10(-11) and (6.3 +/- 2.7) x 10(-11) cm(3) molecule(-1) s(-1) at 298 K, 100 Torr of N(2) diluent, respectively. The upper limit of the reaction rate constant of IO with CH(3)I was <4 x 10(-14) cm(3) molecule(-1) s(-1).

  15. The C IV Mass Density of the Universe at Redshift 5(exp 1)

    NASA Technical Reports Server (NTRS)

    Pettini, Max; Madau, Piero; Bolte, Michael; Prochaska, Jason X.; Ellison, Sara L.; Fan, Xiao-Hui

    2003-01-01

    In order to search for metals in the Ly alpha forest at redshifts z(sub abs) > 4, we have obtained spectra of high signal-to-noise ratio and moderately high resolution of three QSOs at z(sub em) > 5.4 discovered by the Sloan Digital Sky Survey. These data allow us to probe to metal enrichment of the intergalactic medium at early times with higher sensitivity than previous studies. We find 16 C IV absorption systems with column densities logN(C IV) = 12.50-13.98 over a total redshift path Delta X = 3.29. In the redshift interval z = 4.5-5.0, where our statistics are most reliable, we deduce a comoving mass density of C(3+) ions Omega(sub C IV) = (4.3 +/- 2.5) x 10(exp -8) (90% confidence limits) for absorption systems with log N(C IV) > or = 13.0 (for an Einstein-de Sitter cosmology with h = 0.65). This value of Omega(sub C IV) is entirely consistent with those measured at z < 4; we confirm the earlier finding by Songaila that neither the column density distribution of C IV absorbers nor its integral show significant redshift evolution over a period of time that stretches from approx. 1.25 to approx. 4.5 Gyr after the big bang. This somewhat surprising conclusion may be an indication that the intergalactic medium was enriched in metals at z >> 5, perhaps by the sources responsible for its reionization. Alternatively, the C IV systems we see may be associated with outflows from massive star-forming galaxies at later times, while the truly intergalactic metals may reside in regions of the Ly alpha forest of lower density than those probed up to now.

  16. Carbon Dioxide Adsorption on a 5A Zeolite Designed for CO2 Removal in Spacecraft Cabins

    NASA Technical Reports Server (NTRS)

    Mulloth, Lila M.; Finn, John E.

    1998-01-01

    Carbon dioxide adsorption data were obtained for a 5A zeolite manufactured by AlliedSignal Inc. (Des Plaines, Illinois). The material is planned for use in the Carbon Dioxide Removal Assembly (CDRA) for U.S. elements of the International Space Station. The family of adsorption isotherms covers a temperature range of O to 250 C, and a pressure range of 0.001 to 800 torr. Coefficients of the Toth equation are fit to the data. Isosteric heats of adsorption are derived from the equilibrium loading data.

  17. Performance of Soviet and US hydrogen masers

    NASA Technical Reports Server (NTRS)

    Uljanov, Adolph A.; Demidov, Nikolai A.; Mattison, Edward M.; Vessot, Robert F. C.; Allan, David W.; Winkler, Gernot M. R.

    1990-01-01

    The frequencies of Soviet- and U.S.-built hydrogen masers located at the Smithsonian Astrophysical Observatory and at the United States Naval Observatory (USNO) were compared with each other and, via Global Positioning System (GPS) common-view measurements, with three primary frequency-reference scales. The best masers were found to have fractional frequency stabilities as low as 6 times 10(exp -16) for averaging times of approximately 10(exp 4) s. Members of the USNO maser ensemble provided frequency prediction better than 1 times 10(exp 14) for periods up to a few weeks. The frequency residuals of these masers, after removal of frequency drift and rate of change of drift, had stabilities of a few parts in 10(exp -15), with serveral masers achieving residual stabilities well below 1 times 10(exp -15) for intervals from 10(exp 5)s to 2 times 10(exp 6)s. The fractional frequency drifts of the 13 masers studied, relative to the primary reference standards, ranged from -0.2 times 10(exp -15)/day to +9.6 times 10(exp -15)/day.

  18. Exploration of the Eltanin Impact Area (Bellingshausen Sea): Expedition ANT XVIII5a

    NASA Technical Reports Server (NTRS)

    Gersonde, Rainer; Kyte, Frank T.

    2001-01-01

    The impact of the Eltanin asteroid into the Bellingshausen Sea (2.15 Ma) is the only known impact in a deep-ocean (approx. 5 km) basin. On 26 March 2001, the FS Polarstern returned to the impact area during expedition ANT XVIII/5a. Over a period of 14 days, this region was explored by detailed bathymetric mapping, acoustic profiling of sediment deposits, and direct sampling with 18 piston cores and four gravity cores. Preliminary shipboard examination of microfossils showed that sixteen of the piston cores and three gravity cores contained sediments at least as old as the impact event and have a high probability of containing a record of the disturbances caused by the impact. During the expedition, portions of eleven piston cores were opened for preliminary examination of the impact deposits. Visual examination of cores and microscopic identification of suspect impact melt particles were were used to identify ejecta and X-ray radiographs of the opened core segments permitted analysis of sediment structures. Impact deposits were found in nine of the eleven opened cores, and a similar success rate is anticipated in the seven cores remaining to be opened. These preliminary observations indicate that the highest concentrations of meteoritic ejecta and the largest particle sizes appear to occur in the region north of the San Martin seamounts. Recovered debris includes cm-sized melt rocks and a 2.5 cm meteorite. This expedition has confirmed the presence of high concentrations of meteoritic ejecta across a region at least as large as 10(exp 5) sq km. Quantitative analyses of ejecta distribution within this region will require further study, but previous estimates of 1 km for the minimum diameter of the Eltanin asteroid, appear safe.

  19. Stellar Laboratories: 3. New Ba 5, Ba 6, and Ba 7 Oscillator Strengths and the Barium Abundance in the Hot White Dwarfs G191-B2B and RE 0503-289

    NASA Technical Reports Server (NTRS)

    Rauch, T.; Werner, K.; Quinet, P.; Kruk, Jeffrey Walter

    2014-01-01

    Context. For the spectral analysis of high-resolution and high-signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. Reliable Ba 5-7 oscillator strengths are used to identify Ba lines in the spectra of the DA-type white dwarf G191-B2B and the DO-type white dwarf RE 0503-289 and to determine their photospheric Ba abundances. Methods. We newly calculated Ba v-vii oscillator strengths to consider their radiative and collisional bound-bound transitions in detail in our NLTE stellar-atmosphere models for the analysis of Ba lines exhibited in high-resolution and high-S/N UV observations of G191-B2B and RE 0503-289. Results. For the first time, we identified highly ionized Ba in the spectra of hot white dwarfs. We detected Ba vi and Ba vii lines in the Far Ultraviolet Spectroscopic Explorer (FUSE) spectrum of RE 0503-289. The Ba vi/Ba vii ionization equilibrium is well reproduced with the previously determined effective temperature of 70 000 K and surface gravity of log g=7.5. The Ba abundance is 3.5 +/- 0.5 × 10(exp-4) (mass fraction, about 23 000 times the solar value). In the FUSE spectrum of G191-B2B, we identified the strongest Ba vii line (at 993.41 Å) only, and determined a Ba abundance of 4.0 +/- 0.5 × 10(exp-6) (about 265 times solar). Conclusions. Reliable measurements and calculations of atomic data are a pre-requisite for stellar-atmosphere modeling. Observed Ba vi-vii line profiles in two white dwarfs' (G191-B2B and RE 0503-289) far-ultraviolet spectra were well reproduced with our newly calculated oscillator strengths. This allowed to determine the photospheric Ba abundance of these two stars precisely.

  20. Gas-phase reactions of nopinone, 3-isopropenyl-6-oxo-heptanal, and 5-methyl-5-vinyltetrahydrofuran-2-ol with OH, NO{sub 3}, and ozone

    SciTech Connect

    Calogirou, A.; Jensen, N.R.; Nielsen, C.J.; Kotzias, D.; Hjorth, J.

    1999-02-01

    In the troposphere, {alpha}-pinene, {beta}-pinene, limonene, and linalool are mainly oxidized to pinonaldehyde, nopinone, 3-isopropenyl-6-oxoheptanal (IPOH), and 5-methyl-5-vinyltetrahydrofuran-2-ol (MVT), respectively. The rate constant of the reactions of nopinone, IPOH, and MVT with OH, NO{sub 3}, and O{sub 3} were determined by long path FT-IR spectroscopy, and the oxidation products from the reactions between the OH radical and pinonaldehyde, nopinone, IPOH, and MVT were investigated using GC-MS and HPLC. The reaction rate constants (k) for the reactions have been determined at 740 {+-} 5 Torr and 298 {+-} 5 K, and a number of reaction products were identified. From the results obtained in this investigation and previous studies, it was concluded that a typical atmospheric lifetime with respect to chemical reactions was only a few hours for pinonaldehyde, IPOH, and MVT but was much longer for nopinone with a lifetime of about 10 h.

  1. A calibration of the production rate ratio P-21/P-26 by low energy secondry neutrons: Identification of Ne spallation components at the 10(exp 6) atoms/g level in terrestrial samples

    NASA Technical Reports Server (NTRS)

    Graf, TH.; Niedermann, S.; Marti, K.

    1993-01-01

    The spallation ratio (Ne-22/Ne-21)(sub c) from Si was determined as 1.243 plus or minus 0.022 in a terrestrial quartz sample. We carried out a calibration of the in-situ production rate ratio P-21/P-26 in quartz samples for which Be-10 and Al-26 production rates were previously measured. A ratio P-21/P-26 of 0.67 plus or minus 0.12 is obtained.

  2. Emplacement of a Debris Ocean on Mars by Regional-Scale Collapse and Flow at the Crustal Dichotomy

    NASA Technical Reports Server (NTRS)

    Hoffman, N.; Tanaka, K. L.; Kargel, J. S.; Banerdt, W. B.

    2001-01-01

    Giant debris flows could have filled the northern lowlands with approx. 2 km of sediment in 10(exp 3) to 10(exp 5) years by catastrophic regional terrain collapse. The outburst floods and chaos zones are probably the waning stage of this process. Additional information is contained in the original extended abstract.

  3. A YBCO RF-squid variable temperature susceptometer and its applications

    NASA Technical Reports Server (NTRS)

    Zhou, Luwei; Qiu, Jinwu; Zhang, Xianfeng; Tang, Zhimin; Cai, Yimin; Qian, Yongjia

    1991-01-01

    The Superconducting QUantum Interference Device (SQUID) susceptibility using a high-temperature radio-frequency (rf) SQUID and a normal metal pick-up coil is employed in testing weak magnetization of the sample. The magnetic moment resolution of the device is 1 x 10(exp -6) emu, and that of the susceptibility is 5 x 10(exp -6) emu/cu cm.

  4. Picosecond CARS measurements of nitrogen rotational/translational and vibrational temperature in a nonequilibrium Mach 5 flow

    NASA Astrophysics Data System (ADS)

    Montello, A.; Nishihara, M.; Rich, J. W.; Adamovich, I. V.; Lempert, W. R.

    2012-12-01

    Picosecond Unstable-resonator Spatially Enhanced Detection Coherent Anti-Stokes Raman Scattering (USED-CARS) is used for the measurement of nitrogen Q-branch (Δ J = 0) spectra in the subsonic plenum and supersonic flow of a highly nonequilibrium Mach 5 wind tunnel. Spectra are processed to infer rotational/translational ( T rot) and first-level vibrational ( T vib) temperatures in the 200-370 torr plenum simultaneously. Operation of the nominally high reduced electric field ( E/ n peak ~ 500 Td), nsec pulsed discharge alone results in fairly significant vibrational loading, T vib ~ 720 K/ T rot ~ 380 K; addition of an orthogonal low E/ n (~10 Td) DC sustainer discharge produces substantial vibrational loading, T vib ~ 2,000 K/ T rot ~ 450 K. Effects of injection of CO2, NO, and H2 downstream of the pulser-sustainer discharge are examined, which result in vibrational relaxation accompanied by simultaneous gas heating, T vib ~ 800-1,000 K/ T rot ~ 600 K. CARSk measurements within very low-density flows in the Mach 5 expansion nozzle are also performed, with T vib measured in both the supersonic free-stream and downstream of a bow shock created by a 5-mm-diameter cylindrical test object in the Mach 5 flow. Measurements within 300 μm of the cylinder leading edge show that for pure N2, or N2 with 0.25 torr CO2 injection, no vibrational relaxation is observed behind the bow shock.

  5. Picosecond CARS measurements of nitrogen rotational/translational and vibrational temperature in a nonequilibrium Mach 5 flow

    NASA Astrophysics Data System (ADS)

    Montello, A.; Nishihara, M.; Rich, J. W.; Adamovich, I. V.; Lempert, W. R.

    2013-01-01

    Picosecond Unstable-resonator Spatially Enhanced Detection Coherent Anti-Stokes Raman Scattering (USED-CARS) is used for the measurement of nitrogen Q-branch (Δ J = 0) spectra in the subsonic plenum and supersonic flow of a highly nonequilibrium Mach 5 wind tunnel. Spectra are processed to infer rotational/translational ( T rot) and first-level vibrational ( T vib) temperatures in the 200-370 torr plenum simultaneously. Operation of the nominally high reduced electric field ( E/ n peak ~ 500 Td), nsec pulsed discharge alone results in fairly significant vibrational loading, T vib ~ 720 K/ T rot ~ 380 K; addition of an orthogonal low E/ n (~10 Td) DC sustainer discharge produces substantial vibrational loading, T vib ~ 2,000 K/ T rot ~ 450 K. Effects of injection of CO2, NO, and H2 downstream of the pulser-sustainer discharge are examined, which result in vibrational relaxation accompanied by simultaneous gas heating, T vib ~ 800-1,000 K/ T rot ~ 600 K. CARSk measurements within very low-density flows in the Mach 5 expansion nozzle are also performed, with T vib measured in both the supersonic free-stream and downstream of a bow shock created by a 5-mm-diameter cylindrical test object in the Mach 5 flow. Measurements within 300 μm of the cylinder leading edge show that for pure N2, or N2 with 0.25 torr CO2 injection, no vibrational relaxation is observed behind the bow shock.

  6. Evidence for Live Cl-36 in Ca-Al-rich Inclusions from the Ningqiang Carbonaceous Chondrite

    NASA Technical Reports Server (NTRS)

    Lin, Y.; Guan, Y.; Leshin, L. A.; Ouyang, Z.; Wang, D.

    2004-01-01

    The short-lived radionuclide Cl-36 decays to either Ar-36 (98.1%, beta(sup -)) or S-36 (1.9%, epsilon and beta(sup +)), with a half life of 3.01 x 10(exp 5) yr. Both the nucleosynthetic and spallation models suggest high initial Cl-36/Cl-35 ratios ((Cl-36/Cl-35)o up to approximately 10(exp -4)) in the early solar system. Previous observed excess Ar-36 in Efremovka matrix has been interpreted to represent a much lower (Cl-36/Cl-35)o ratio of approximately 1 x 10(exp -6). From the observed S-36 excesses in sodalite in calcium aluminum-rich inclusions (CAIs), we report in this study the first direct evidence of the presence of Cl-36 in primitive meteorites. The inferred (Cl-36/Cl-35)o ratios range from approximately 5 x 10(exp -6) to approximately 1 x 10(exp -5).

  7. Anomalous Variability in Antarctic Sea Ice Extents During the 1960s With the Use of Nimbus Data

    NASA Technical Reports Server (NTRS)

    Gallaher, David W.; Campbell, G. Garrett; Meier, Walter N.

    2013-01-01

    The Nimbus I, II, and III satellites provide a new opportunity for climate studies in the 1960s. The rescue of the visible and infrared imager data resulted in the utilization of the early Nimbus data to determine sea ice extent. A qualitative analysis of the early NASA Nimbus missions has revealed Antarctic sea ice extents that are significant larger and smaller than the historic 1979-2012 passive microwave record. The September 1964 ice mean area is 19.7x10(exp 6) sq. km +/- 0.3x10(exp 6) sq. km. This is more the 250,000 sq. km greater than the 19.44x10(exp 6) sq. km seen in the new 2012 historic maximum. However, in August 1966 the maximum sea ice extent fell to 15.9x10(exp 6) sq. km +/- 0.3x10(exp 6) sq. km. This is more than 1.5x10(exp 6) sq. km below the passive microwave record of 17.5x10(exp 6) sq. km set in September of 1986. This variation between 1964 and 1966 represents a change of maximum sea ice of over 3x10(exp 6) sq. km in just two years. These inter-annual variations while large, are small when compared to the Antarctic seasonal cycle.

  8. Properties of the Flight Model Gas Electron Multiplier for the GEMS Mission

    NASA Technical Reports Server (NTRS)

    Takeuchi, Yoko; Kitaguchi, Takao; Hayato, Asami; Tamagawa, Toru; Iwakiri, Wataru; Asami, Fumi; Yoshikawa, Akifumi; Kaneko, Kenta; Enoto, Teruaki; Black, Kevin; Hill, Joanne E.; Jahoda, Keith

    2014-01-01

    We present the gain properties of the gas electron multiplier (GEM) foil in pure dimethyl ether (DME) at 190 Torr. The GEM is one of the micro pattern gas detectors and it is adopted as a key part of the X-ray polarimeter for the GEMS mission. The X-ray polarimeter is a time projection chamber operating in pure DME gas at 190 Torr. We describe experimental results of (1) the maximum gain the GEM can achieve without any discharges, (2) the linearity of the energy scale for the GEM operation, and (3) the two-dimensional gain variation of the active area. First, our experiment with 6.4 keV X-ray irradiation of the whole GEM area demonstrates that the maximum effective gain is 2 x 10(exp 4) with the applied voltage of 580 V. Second, the measured energy scale is linear among three energies of 4.5, 6.4, and 8.0 keV. Third, the two-dimensional gain mapping test derives the standard deviation of the gain variability of 7% across the active area.

  9. Temperature Dependence of the O + HO2 Rate Coefficient

    NASA Technical Reports Server (NTRS)

    Nicovich, J. M.; Wine, P. H.

    1997-01-01

    A pulsed laser photolysis technique has been employed to investigate the kinetics of the radical-radical reaction O((sup 3)P) + HO2 OH + O2 over the temperature range 266-391 K in 80 Torr of N2 diluent gas. O((sup 3)P) was produced by 248.5-nm KrF laser photolysis of O3 followed by rapid quenching of O(1D) to O((sup 3)P) while HO2 was produced by simultaneous photolysis of H2O2 to create OH radicals which, in turn, reacted with H2O2 to yield HO2. The O((sup 3)P) temporal profile was monitored by using time-resolved resonance fluorescence spectroscopy. The HO2 concentration was calculated based on experimentally measured parameters. The following Arrhenius expression describes our experimental results: k(sub 1)(T) equals (2.91 +/- 0.70) x 10(exp -11) exp[(228 +/- 75)/T] where the errors are 2 sigma and represent precision only. The absolute uncertainty in k, at any temperature within the range 266-391 K is estimated to be +/- 22 percent. Our results are in excellent agreement with a discharge flow study of the temperature dependence of k(sub 1) in 1 Torr of He diluent reported by Keyser, and significantly reduce the uncertainty in the rate of this important stratospheric reaction at subambient temperatures.

  10. Relic gravitational waves and extended inflation

    NASA Technical Reports Server (NTRS)

    Turner, Michael S.; Wilczek, Frank

    1990-01-01

    In extended inflation, a new version of inflation where the transition from the false-vacuum phase to a radiation-dominated Universe is accomplished by bubble nucleation and percolation, bubble collisions supply a potent-and potentially detectable-source of gravitational waves. The present energy density in relic gravity waves from bubble collisions is expected to be about 10(exp -5) of closure density-many orders of magnitude greater than that of the gravity waves produced by quantum fluctuations. Their characteristic wavelength depends upon the reheating temperature T(sub RH): lambda is approximately 10(exp 4) cm (10(exp 14) GeV/T(sub RH)). If large numbers of black holes are produced, a not implausible outcome, they will evaporate producing comparable amounts of shorter wavelength waves, lambda is approximately 10(exp -6) cm (T(sub RH)/10(exp 14) GeV).

  11. C5HIO5W

    NASA Astrophysics Data System (ADS)

    Mikhova, B. M.

    This document is part of Subvolume D5 `Chemical Shifts and Coupling Constants for Carbon-13. Part 5: Organometallic Compounds' of Volume 35 `Nuclear Magnetic Resonance Data' of Landolt-Börnstein Group III: `Condensed Matter'.

  12. Highly ionized gas absorption in the disk and halo toward HD 167756 at 3.5 kilometers per second resolution

    NASA Technical Reports Server (NTRS)

    Savage, Blair D.; Sembach, Kenneth R.; Cardelli, Jason A.

    1994-01-01

    High-resolution spectra of interstellar Si IV, C IV, and N V absorption lines along the 4 kpc path to the inner Galaxy star HD 167756 at z = -0.85 kpc are presented. The spectra were obtained with the echelle mode of Goddard High Resolution Spectrograph (GHRS) aboard the Hubble Space Telescope (HST) and have signal-to-noise ratios ranging from 23 to 38. The high resolution of the measurements full width at half maximum (FWHM = 3.5 km/s) results in fully resolved line profiles for the highly ionized gas absorption. The measurements provide information on the column density per unit velocity, N(v), as a function of velocity for Si IV, C IV, and N V. The C IV and N V profiles extend from -70 to +70 km/s, while the Si IV profiles extend from -40 to +70 km/s. The integrated logarithmic column densities are long N(Si IV) = 13.09 +/- 0.02, log N(C IV) = 13.83 +/- 0.02, and log N(N V) = 13.56 +/- 0.03. The N V profile is broad, asymmetric, and featureless, while the Si IV profile contains narrow absorption components near V(sub LSR) = -19, 0, +20, and +52 km/s with Doppler spread parameters, b about = 10-12 km/s. The C IV profile contains both broad and narrow structure. The high ion feature near +52 km/s is also detected in the low-ionization lines of Ca II, O I, Si II, and Fe II. The other narrow Si IV and C IV components occur within several km/s of components seen in low-ionization species. The sight line contains at least two types of highly ionized gas. One type gives rise to a broad N V profile, and the other results in the more structured Si IV profile. The C IV profile contains contributions from both types of highly ionized gas. The broad but asymmetric N V profile is well represented by a large Galactic scale height gas which is participating in Galactic rotation and has a combination of thermal and turbulent broadening with b(sub tot) about = 42 km/s. The C IV to N V abundance ratio of 1.0 +/- 0.3 for the gas implies T about 1.6 x 10(exp 5) K or about 8 x 10

  13. Discovery of a Similar to 5 Day Characteristic Timescale in the Kepler Power Spectrum of Zw 229-15

    NASA Technical Reports Server (NTRS)

    Edelson, R.; Vaughan, S.; Malkan, M.; Kelly, B. C.; Smith, K. L.; Boyd, P. T.; Mushotzky, R.

    2014-01-01

    We present time series analyses of the full Kepler dataset of Zw 229- 15. This Kepler light curve- with a baseline greater than three years, composed of virtually continuous, evenly sampled 30-minute measurements - is unprecedented in its quality and precision. We utilize two methods of power spectral analysis to investigate the optical variability and search for evidence of a bend frequency associated with a characteristic optical variability timescale. Each method yields similar results. The first interpolates across data gaps to use the standard Fourier periodogram. The second, using the CARMA-based time-domain modeling technique of Kelly et al., does not need evenly-sampled data. Both methods find excess power at high frequencies that may be due to Kepler instrumental effects. More importantly both also show strong bends (delta alpha is approx. 2) at timescales of approx. 5 days, a feature similar to those seen in the X-ray PSDs of AGN but never before in the optical. This observed approx. 5 day timescale may be associated with one of several physical processes potentially responsible for the variability. A plausible association could be made with light -crossing, dynamical or thermal timescales, depending on the assumed value of the accretion disk size and on unobserved disk parameters such as alpha and H¬R. This timescale is not consistent with the viscous timescale, which would be years in a approx. 10(exp7) solar mass AGN such as Zw 229- 15. However there must be a second bend on long (& 1 year) timescales, and that feature could be associated with the viscous timescale.

  14. Morphology, Structural and Dielectric Properties of Vacuum Evaporated V2O5 Thin Films

    NASA Astrophysics Data System (ADS)

    Sengodan, R.; Shekar, B. Chandar; Sathish, S.

    Vanadium pentoxide (V2O5) thin films were deposited on well cleaned glass substrate using evaporation technique under the pressure of 10-5 Torr. The thickness of the films was measured by the multiple beam interferometry technique and cross checked by using capacitance method. Metal-Insulator-Metal (MIM) structure was fabricated by using suitable masks to study dielectric properties. The dielectric properties were studied by employing LCR meter in the frequency range 12 Hz to 100 kHz for various temperatures. The temperature co- efficient of permittivity (TCP), temperature co-efficient of capacitance (TCC) and dielectric constant (ɛ) were calculated. The activation energy was calculated and found to be very low. The activation energy was found to be increasing with increase in frequency. The obtained low value of activation energy suggested that the hopping conduction may be due to electrons rather than ions.

  15. Carbon Nanotube Vacuum Gauges Utilizing Long, Dissipative Tubes

    NASA Technical Reports Server (NTRS)

    Kaul, Anupama B.; Manohara, Harish M.

    2008-01-01

    CNT Vacuum Gauges: a) have a broad range of pressure response from 760 - 10(exp -6) Torr. b) have current changes approx. 100's nA in high vacuum regime (10(exp -6) Torr) and sensitivity increases with power and substrate removal. c) have a negative dR/dT (TCR negative) where a thermal hopping energy E(sub a) was determined to be approx. 40 meV. d) have compatible fabrication requirements for their integration with micromachined structures. e) can be operated at low power (nW - micro-W). f) have an active device region footprint of < 10 sq microns. g) are non-intrusive due to small size and passive operation.

  16. Thermal Performance of Biological Substance Systems in Vitro Under Static and Dynamic Conditions at the Cryogenic Test Laboratory, NASA Kennedy Space Center, USA

    NASA Technical Reports Server (NTRS)

    Augustynowicz, S. D.; Fesmire, James E.; Steinrock, T. (Technical Monitor)

    2001-01-01

    A unique research program, including a comprehensive study of thermal performance at cryogenic vacuum insulation systems, was performed at the NASA Kennedy Space Center. The main goal was to develop a new soft vacuum system (from 1 torr to 10 torr) that provides an intermediate level of performance (k-value below 4.8 mW/m-K). Liquid nitrogen boil-off methods were used to test conventional materials, novel materials, and certain combinations. The test articles included combinations of aluminum foil, fiberglass paper, polyester fabric, silica aerogel composite blanket, fumed silica, silica aerogel powder, and syntactic foam. A new LCI system was developed at the Cryogenics Test Laboratory. This system performs exceptionally well at soft vacuum levels and nearly as good as an MLI at high vacuum levels. Apparent thermal conductivities for the LCI range from 2 mW/m-K at soft vacuum to 0.1 mW/m-K at high vacuum. Several cryostats were designed, constructed, and calibrated by the Cryogenics Test Laboratory at KSC NASA as part of this research program. The cryostat test apparatus is a liquid nitrogen boil-off calorimeter system for direct measurement of the apparent thermal conductivity at a fixed vacuum level between 5 x 10(exp -5) and 760 torr. The apparatus is also used for transient measurements of temperature profiles. The development of efficient, robust cryogenic insulation systems has been a targeted area of research for a number of years. Improved methods of characterization, testing, and evaluation of complex biological substance systems for cryosurgery and cryobiology are the focus of this paper.

  17. 5-HTP

    MedlinePlus

    ... taking 5-HTP with D-phenylalanine and L-glutamine for 40 days can reduce alcohol withdrawal symptoms. ... 6 days together with tyrosine, phosphatidylcholine, and L-glutamine, might reduce insomnia and withdrawal symptoms in recovering ...

  18. Thermal electron attachment to SO3

    SciTech Connect

    Miller, T.M.; Viggiano, A.A.; Arnold, S.T.; Jayne, J.T.

    1995-04-15

    The rate constant for electron attachment to SO3 is 3 + or - 1 x 10(exp-9) cu cm/s at 300 K, measured in helium gas at pressures from 53 to 160 Pa (0.4 to 1.2 torr). The sole product of attachment is SO3(-) under these conditions. The same rate constant and ionic product were obtained at 400 and 505 K. The measurements were carried out using a flowing-afterglow Langmuir-probe apparatus.

  19. X-5

    NASA Technical Reports Server (NTRS)

    1957-01-01

    This NACA High-Speed Flight Research Station photograph of the X-5 was taken at Edwards Air Force Base in the mid 1950s. The photograph shows the aircraft in flight with the wings swept back. The Bell, X-5 was flight tested at the NACA High-Speed Flight Research Station (now the NASA Dryden Flight Research Center, Edwards, California) from 1952 to 1955. The X-5 was the first aircraft capable of sweeping its wings in flight. It helped provide data about wing-sweep at angles of up to 60 degrees at subsonic and transonic speeds. There were two X-5 vehicles. Ship 1 was flown at the NACA High-Speed Flight Research Station (High-Speed Flight Station, as it was redesignated in 1954) from 1951 to 1955. Ship 2 was operated by Bell and the U.S. Air Force and was lost in a spin accident in 1953. Following the conclusion of the contractor's test program, the X-5 was grounded for installation of a NACA instrument package. The Air Force conducted a short, six-flight, evaluation program. Since the Air Force evaluation program included data collection, it was considered as part of the overall NACA effort and flights were logged as AF/NACA. In the NACA test program, the X-5 demonstrated severe stall-spin instability. The X-5 was also used as a chase plane for other research aircraft because it could vary its flying characteristics to suit the airplane it was chasing. Ship 1 flew a total of 133 flights during its three years of service. In spite of the problems with the aircraft, the X-5 provided a significant full-scale verification of NACA wind-tunnel predictions for reduced drag and improved performance that resulted from this configuration's increasing the wing sweep as the speed of the aircraft approached the speed of sound. The X-5 flight tests provided some of the design data for the Air Force F-111 and Navy F-14 tactical aircraft. Although the mechanism by which the X-5 changed its wing sweep made this particular design impractical, development of a viable variable

  20. 5 experiments in 5 minutes

    NASA Astrophysics Data System (ADS)

    Hut, Rolf

    2015-04-01

    Show, don't tell. When kids ask about your research, show, don't tell. We, the ambassadors of science, shouldn't be boring our nieces and nephews at family dinners with parameter distributions, we should make them excited about science. Getting people excited: show, don't tell. In 5 minutes, I will perform 5 experiments that anyone can do using everyday household items to get kids interested in science. Bring safety glasses.

  1. High-Sensitivity, Broad-Range Vacuum Gauge Using Nanotubes for Micromachined Cavities

    NASA Technical Reports Server (NTRS)

    Manohara, Harish; Kaul, Anupama B.

    2011-01-01

    A broad-range vacuum gauge has been created by suspending a single-walled carbon nanotube (SWNT) (metallic or semiconducting) in a Schottky diode format or in a bridge conductor format, between two electrically charged mesas. SWNTs are highly sensitive to molecular collisions because of their extremely small diameters in the range of 1 to 3 nanometers. The measurement parameter will be the change in conductivity of SWNT due to decreasing rate of molecular collisions as the pressure inside a chamber decreases. The rate of heat removal approaches a saturation limit as the mean free path (m.f.p.) lengths of molecules increase due to decreasing pressure. Only those sensing elements that have a long relaxation time can produce a measureable response when m.f.p. of molecules increases (or time between two consecutive collisions increases). A suspended SWNT offers such a capability because of its one-dimensional nature and ultrasmall diameter. In the initial approach, similar architecture was used as that of a SWNT-Schottky diode that has been developed at JPL, and has its changing conductivity measured as the test chamber is pumped down from atmospheric pressure to high vacuum (10(exp -7) Torr). Continuous response of decreasing conductivity has been measured as a function of decreasing pressure (SWNT is a negative thermal coefficient material) from atmosphere to less than 10(exp -6) Torr. A measureable current change in the hundreds of nA range has been recorded in the 10(exp -6) Torr regime.

  2. All-Sky Search for Periodic Gravitational Waves in the Full S5 LIGO Data

    NASA Technical Reports Server (NTRS)

    Abadie, J.; Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M.; Accadia, T.; Acernese, F.; Adams, C.; Adhikari, R.; Affeldt, C.; Ajith, P.; Allen, B.; Allen, G. S.; Amador Ceron, E.; Amariutei, D.; Amin, R. S.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Arain, M. S.; Araya, M. C.; Aston, S. M.; Blackburn, L.; Camp, J. B.; Cannizzo, J.

    2011-01-01

    We report on an all-sky search for periodic gravitational waves in the frequency band 50-800 Hz and with the frequency time derivative in the range of 0 through -6 x 10(exp -9) Hz/s. Such a signal could be produced by a nearby spinning and slightly non-axisymmetric isolated neutron star in our galaxy. After recent improvements in the search program that yielded a 10x increase in computational efficiency, we have searched in two years of data. collected during LIGO's fifth science run and have obtained the most sensitive all-sky upper limits on gravitational wave strain to date. Near 150 Hz our upper limit on worst-case linearly polarized strain amplitude h(sub 0) is 1 x 10(exp -24), while at the high end of our frequency ra.nge we achieve a worst-case upper limit of 3.8 x 10(exp -24) for all polarizations and sky locations. These results constitute a factor of two improvement upop. previously published data. A new detection pipeline utilizing a Loosely Coherent algorithm was able to follow up weaker outliers, increasing the volume of space where signals can be detected by a factor of 10, but has not revealed any gravitational wave signals. The pipeline has been tested for robustness with respect to deviations from the model of an isolated neutron star, such as caused by a low-mass or long.period binary companion.

  3. Effect of Particle Non-Sphericity on Satellite Monitoring of Drifting Volcanic Ash Clouds

    NASA Technical Reports Server (NTRS)

    Krotkov, Nicholay A.; Flittner, D. E.; Krueger, A. J.; Kostinski, A.; Riley, C.; Rose, W.

    1998-01-01

    Volcanic eruptions loft gases and ash particles into the atmosphere and produce effects that are both short term (aircraft hazards, interference with satellite measurements) and long term (atmospheric chemistry, climate). Large (greater than 0.5mm) ash particles fall out in minutes [Rose et al, 1995], but fine ash particles can remain in the atmosphere for many days. This fine volcanic ash is a hazard to modem jet aircraft because the operating temperatures of jet engines are above the solidus temperature of volcanic ash, and because ash causes abrasion of windows and airframe, and disruption of avionics. At large distances(10(exp 2)-10(exp 4) km or more) from their source, drifting ash clouds are increasingly difficult to distinguish from meteorological clouds, both visually and on radar [Rose et al., 1995]. Satellites above the atmosphere are unique platforms for viewing volcanic clouds on a global basis and measuring their constituents and total mass. Until recently, only polar AVHRR and geostationary GOES instruments could be used to determine characteristics of drifting volcanic ash clouds using the 10-12 micron window [Prata 1989; Wen and Rose 1994; Rose and Schneider 1996]. The NASA Total Ozone Mapping Spectrometer (TOMS) instruments aboard the Nimbus-7, Meteor3, ADEOS, and Earth Probe satellites have produced a unique data set of global SO2 volcanic emissions since 1978 (Krueger et al., 1995). Besides SO2, a new technique has been developed which uses the measured spectral contrast of the backscattered radiances in the 330-380nm spectral region (where gaseous absorption is negligible) in conjunction with radiative transfer models to retrieve properties of volcanic ash (Krotkov et al., 1997) and other types of absorbing aerosols (Torres et al., 1998).

  4. [5]Radialene.

    PubMed

    Mackay, Emily G; Newton, Christopher G; Toombs-Ruane, Henry; Lindeboom, Erik Jan; Fallon, Thomas; Willis, Anthony C; Paddon-Row, Michael N; Sherburn, Michael S

    2015-11-25

    The [n]radialenes are a unique family of fundamental [n]-membered carbocyclic structures with radiating alkenes, which have attracted significant synthetic and theoretical attention. Whereas [3]-, [4]-, and [6]radialenes have been prepared and studied, all efforts to synthesize the five-membered ring compound have thus far met with failure. Here we describe the first synthesis of the fundamental hydrocarbon [5]radialene, C10H10. Our approach was a departure from previous radialene syntheses in that it utilized a low-temperature decomplexation of a stable organometallic compound, rather than high-temperature elimination or rearrangement. Our strategy was guided by analysis of previous radialene syntheses, which indicated rapid decomposition in oxygen, and ab initio calculations, which revealed an extraordinary susceptibility of [5]radialene to undergo Diels-Alder dimerization/polymerization. The origin of this susceptibility was traced to a small distortion energy associated with the formation of the transition structure geometry from the relaxed reactant monomers and to a narrow HOMO-LUMO gap.

  5. Population of Nitrifying Bacteria and Nitrification in Ammonium Saturated Clinoptilolite

    NASA Technical Reports Server (NTRS)

    McGilloway, R. L.; Weaver, R. W.; Ming, Douglas W.; Gruener, J.

    1999-01-01

    As humans begin to spend longer periods of time in space, plants will be incorporated into life support systems. Ammonium saturated clinoptilolite is one plant growth substrate but a balance between ammonium and nitrate is needed. A laboratory study was conducted to determine effects of nitrifying bacteria on ammonium concentrations and kinetics of nitrification. Columns containing clinoptilolite substrate amended with nitrifying bacteria obtained from soil enrichment were analyzed weekly for a 90 day period. The enrichment culture initially contained 1 x 10(exp 5) ammonium oxidizing bacteria and 1 x 10(exp 2) nitrite oxidizing bacteria per gram of substrate. Populations of ammonium oxidizing bacteria increased to 1 x 10(exp 6) and nitrite oxidizing bacteria increased to 1 x 10(exp 3) per gram of substrate. The nitrification rate was approximately 0.25mg NO3(-)-N/kg.hr. Experiments were also conducted to enumerate nitrifying bacteria in a clinoptilolite substrate used to grow wheat (Triticum aestivum L.). Seventy days following the initial inoculation with an unknown number of commercial nitrifying bacteria, 1 x 10(exp 5) ammonium oxidizing bacteria per gram of substrate were present. The number of nitrite oxidizing bacteria was between 1 x 10(exp 3) to 10(exp 4) per gram of substrate as measured by the most probable number method. Nitrification rates were approximately 0.20mg NO3(-)-N/kg.hr. Clinoptilolite readily exchanged sufficient concentrations of ammonium to support nitrifying bacteria and they survived well in this medium.

  6. The Composition of Titan's Lower Atmosphere and Simple Surface Volatiles as Measured by the Cassini-Huygens Probe Gas Chromatograph Mass Spectrometer Experiment

    NASA Technical Reports Server (NTRS)

    Niemann, H. B.; Atreya, S. K.; Demick, J. E.; Gautier, D.; Haberman, J. A.; Harpold, D. N.; Kasprzak, W. T.; Lunine, J. I.; Owen, T. C.; Raulin, F.

    2010-01-01

    The Cassini-Huygens Probe Gas Chromatograph Mass Spectrometer (GCMS) determined the composition of the Titan atmosphere from 140km altitude to the surface. After landing, it returned composition data of gases evaporated from the surface. Height profiles of molecular nitrogen (N2), methane (CH4) and molecular hydrogen (H2) were determined. Traces were detected on the surface of evaporating methane, ethane (C2H6), acetylene (C2H2), cyanogen (C2N2) and carbon dioxide (CO2). The methane data showed evidence that methane precipitation occurred recently. The methane mole fraction was (1.48+/-0.09) x 10(exp -2) in the lower stratosphere (139.8 km to 75.5 km) and (5.65+/-0.18) x 10(exp -2) near the surface (6.7 km to the surface). The molecular hydrogen mole fraction was (1.01+/-0.16) x 10(exp -3) in the atmosphere and (9.90+/-0.17) x 10(exp -4) on the surface. Isotope ratios were 167.7+/-0.6 for N-14/N-15 in molecular nitrogen, 91.1+/-1.4 for C-12/C-13 in methane and (1.35+/-0.30) x 10(exp -4) for D/H in molecular hydrogen. The mole fractions of Ar-36 and radiogenic Ar-40 are (2.1+/-0.8) x 10(exp -7) and (3.39 +/-0.12) x 10(exp -5) respectively. Ne-22 has been tentatively identified at a mole fraction of (2.8+/-2.1) x 10(exp -7) Krypton and xenon were below the detection threshold of 1 x 10(exp -8) mole fraction. Science data were not retrieved from the gas chromatograph subsystem as the abundance of the organic trace gases in the atmosphere and on the ground did not reach the detection threshold. Results previously published from the GCMS experiment are superseded by this publication.

  7. Kinetics and Thermochemistry of Reversible Adduct Formation in the Reaction of Cl((sup 2)P(sub J)) with CS2

    NASA Technical Reports Server (NTRS)

    Nicovich, J. M.; Shackelford, C. J.; Wine, P. H.

    1997-01-01

    Reversible adduct formation in the reaction of Cl((sup 2)P(sub J)) with CS2 has been observed over the temperature range 193-258 K by use of time-resolved resonance fluorescence spectroscopy to follow the decay of pulsed-laser-generated Cl((sup 2)P(sub J)) into equilbrium with CS2Cl. Rate coefficients for CS2Cl formation and decomposition have been determined as a function of temperature and pressure; hence, the equilbrium constant has been determined as a function of temperature. A second-law analysis of the temperature dependence of Kp and heat capacity corrections calculated with use of an assumed CS2Cl structure yields the following thermodynamic parameters for the association reaction: Delta-H(sub 298) = -10.5 +/- 0.5 kcal/mol, Delta-H(sub 0) = -9.5 +/- 0.7 kcal/mol, Delta-S(sub 298) = -26.8 +/- 2.4 cal/mol.deg., and Delta-H(sub f,298)(CS2Cl) = 46.4 +/- 0.6 kcal/mol. The resonance fluorescence detection scheme has been adapted to allow detection of Cl((sup 2)P(sub J)) in the presence of large concentrations of O2, thus allowing the CS2Cl + Cl + O2 reaction to be investigated. We find that the rate coefficient for CS2Cl + O2 reaction via all channels that do not generate Cl((sup 2)P(sub J)) is less than 2.5 x 10(exp-16) cu cm/(molecule.s) at 293 K and 300-Torr total pressure and that the total rate coefficient is less than 2 x 10 (exp -15) cu cm/(molecule.s) at 230 K and 30-Torr total pressure. Evidence for reversible adduct formation in the reaction of Cl((sup 2)P(sub J)) with COS was sought but not observed, even at temperatures as low as 194 K.

  8. Optical pumping of chemical HF lasers on the basis of NF{sub 3}-H{sub 2} and ClF{sub 5}-H{sub 2} mixtures by an open surface discharge in the bleaching-wave mode

    SciTech Connect

    Artem'ev, Mikhail Yu; Mikheev, L D; Nesterov, V M; Cheremiskin, V I; Bashkin, A S; Sentis, M L

    2001-07-31

    Lasing on HF upon optical pumping by emission of an open discharge, using NF{sub 3} and ClF{sub 5} as donors of fluorine atoms, was obtained for the first time in a chemical laser and the bleaching-wave mode was realised in a chemical HF laser. An open surface discharge was used as a pump source. The velocity of the bleaching wave, which was formed under its action, reached {approx}8 km s{sup -1}. The formation of this wave leads to a rapid (with an ultrasonic velocity) replacement of the working medium in the lasing region, which provides a quantum laser efficiency close to unity. The optimum compo-sition of the working mixture was found to be NF{sub 3}:H{sub 2}:Kr =6:10:125 Torr. For this composition, the output laser energy in a 3.2-{mu}s pulse reached {approx}0.4 J and the specific output energy was 3.5 J litre{sup -1}. Approximately the same output characteristics of laser emission (0.35 J in a 3.5-{mu}s pulse in the ClF{sub 5}:H{sub 2}:Kr=3:20:50 Torr mixture) were obtained in the system using ClF{sub 5} as donors of fluorine atoms. (lasers, active media)

  9. Herman-Wallis factors in the C2H2nu5 infrared fundamental near 14 microns

    NASA Technical Reports Server (NTRS)

    Maguire, William C.; Hillman, John J.; Weber, Mark; Blass, William E.

    1991-01-01

    The presence of acetylene has been confirmed for some time in the atmospheres of the outer planets Jupiter, Saturn, Neptune, and Saturn's satellite Titan. For these atmospheres, the determination of C2H2 abundances using its strong nu5 fundamental requires laboratory line position and intensity measurements. The 1-m Fourier transform spectrometer at McMath solar telescope of Kitt Peak National Observatory was used to measure C2H2 at an unapodized spectral resolution of 0.0025/cm. Synthetic spectra are generated by convolving a Voigt line shape with an instrument function and varying intensity parameters by means of a nonlinear least squares technique. Intensities of 37 nu5 lines spanning P18 through R20 were measured using 0.123 torr of gas in a 1-cm cell. A Herman-Wallis intensity correction parameter of 1.3(4) x 10 to the -3rd has been derived using a least squares linear fit.

  10. Environmental Perturbations Caused by the Impacts of Comets and Asteroids on Earth

    NASA Technical Reports Server (NTRS)

    Toon, Owen B.; Lawless, James G. (Technical Monitor)

    1994-01-01

    The extinction mechanisms proposed at the Cretaceous-Tertiary geological boundary are reviewed and related to the impact of asteroids or comets in general. For impact energies below 10(exp 4) Megatons (less than 6 x 10(exp 4) years; asteroid diameter less than 650 m), blast, earthquake, and fire may destroy local areas up to 10(exp 5) square m. Tidal waves could flood a kilometer inland over entire ocean basins. The energy range from 105 to 106 Megatons (less than 2 x 10(exp 6) years; asteroid diameter less than 3 km) is transitional. Dust lifted, sulfur released from within impacting asteroids, and soot from fires started by comets can produce climatologically significant optical depths of 10. At energies beyond 10(exp 7) Megatons, blast and earthquake damage is regional (10(exp 6) square cm). Tsunami cresting to 100 m and flooding 20 km inland will sweep the coastal zones of the world's oceans. Fires will be set globally. Light levels may drop so low from the smoke, dust and sulfate that vision is not possible. At energies approaching 10(exp 9) Megatons the ocean surface waters may be acidified by sulfur. The combination of these effects would be devastating.

  11. The electrical conductivities of the DSS-13 beam-waveguide antenna shroud material and other antenna reflector surface materials

    NASA Technical Reports Server (NTRS)

    Otoshi, T. Y.; Franco, M. M.; Reilly, H. F., Jr.

    1992-01-01

    A significant amount of noise temperature can potentially be generated by currently unknown dissipative losses in the beam waveguide (BWG) shroud. The amount of noise temperature contribution from this source is currently being studied. In conjunction with this study, electrical conductivity measurements were made on samples of the DSS-13 BWG shroud material at 8.420 GHz. The effective conductivities of unpainted and painted samples of the BWG shroud were measured to be 0.01 x 10(exp 7) and 0.0036 x 10(exp 7) mhos/m, respectively. This value may be compared with 5.66 x 10(exp 7) mhos/m for high conductivity copper.

  12. Pulsed high-energy gamma-radiation from Geminga (1E0630 + 178)

    NASA Technical Reports Server (NTRS)

    Bertsch, D. L.; Brazier, K. T. S.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mattox, J. R.

    1992-01-01

    The detection of pulsed gamma rays with energy above 50 MeV from the soft X-ray source 1E0630 + 178 is reported, confirming the identification of Geminga with this X-ray source. The period derivative (11.4 +/- 1.7) x 10 exp -15 s/s suggests that Geminga is a nearby isolated rotating neutron star with a magnetic field of 1.6 x 10 exp 12 gauss, a characteristic age of 300,000 yr, and a spin-down energy loss rate of 3.5 x 10 exp 34 erg/s.

  13. Excitation rate and background measurements during LIF studies on krypton

    NASA Astrophysics Data System (ADS)

    Whitehead, C. A.; Cannon, B. D.; Wacker, J. F.

    1993-04-01

    The Krypton Isotope Laser Analysis (KILA) method is being developed at the Pacific Northwest Laboratory (PNL) to measure Kr-85 concentrations in small air samples. The technique uses high-resolution lasers to excite individual isotopes of krypton specifically to induce Kr-85 to fluorescence for detection by optical means. Production of krypton metastables via two-photon excitation to the 2p(sub 6) state has been shown to be 0.15% efficient in 0.13 mTorr of krypton--sufficiently high to demonstrate overall feasibility of the KILA method. Since this goal was met, focus has been directed toward development of a working vacuum ultraviolet (VUV) fluorescence detection system and toward understanding the VUV background. This report describes the progress made in these two areas. The second step of the KILA process is to optically pump all except the Kr-85 isotopes from the metastable state back to the ground state using laser-induced fluorescence (LIF). The rate of this process and the VUV background afterward will determine the sensitivity and selectivity of the KILA approach. De-excitation of the metastable population was accomplished via one-photon absorption of a continuous-wave (c-w) laser to the 2p(sub 8) energy level. Non-isotopically selective de-excitation rates as high as 5 x 10(exp 5)/sec have been measured, yielding a signal-to-background ratio of g reater than 10(exp 6). The lifetime of the metastables is 1.2 msec in 200 mTorr of neon--much longer than the time required to de-excite krypton metastables and to detect fluorescence produced by Kr-85. After attaining these high de-excitation rates, a gated VUV detection system was built with a dynamic range large enough to measure a small background following de-excitation of large metastable populations. Future experiments will focus on reducing the background level by another 2-3 orders of magnitude and perfecting the isotopically selective de-excitation technique with known samples.

  14. Coating Thermoelectric Devices To Suppress Sublimation

    NASA Technical Reports Server (NTRS)

    Sakamoto, Jeffrey; Caillat, Thierry; Fleurial, Jean-Pierre; Snyder, G. Jeffrey

    2007-01-01

    A technique for suppressing sublimation of key elements from skutterudite compounds in advanced thermoelectric devices has been demonstrated. The essence of the technique is to cover what would otherwise be the exposed skutterudite surface of such a device with a thin, continuous film of a chemically and physically compatible metal. Although similar to other sublimation-suppression techniques, this technique has been specifically tailored for application to skutterudite antimonides. The primary cause of deterioration of most thermoelectric materials is thermal decomposition or sublimation - one or more elements sublime from the hot side of a thermoelectric couple, changing the stoichiometry of the device. Examples of elements that sublime from their respective thermoelectric materials are Ge from SiGe, Te from Pb/Te, and now Sb from skutterudite antimonides. The skutterudite antimonides of primary interest are CoSb3 [electron-donor (n) type] and CeFe(3-x)Co(x)Sb12 [electron-acceptor (p) type]. When these compounds are subjected to typical operating conditions [temperature of 700 C and pressure <10(exp -5) torr (0.0013 Pa)], Sb sublimes from their surfaces, with the result that Sb depletion layers form and advance toward their interiors. As the depletion layer advances in a given device, the change in stoichiometry diminishes the thermal-to-electric conversion efficiency of the device. The problem, then, is to prevent sublimation, or at least reduce it to an acceptably low level. In preparation for an experiment on suppression of sublimation, a specimen of CoSb3 was tightly wrapped in a foil of niobium, which was selected for its chemical stability. In the experiment, the wrapped specimen was heated to a temperature of 700 C in a vacuum of residual pressure <10(exp -5) torr (0.0013 Pa), then cooled and sectioned. Examination of the sectioned specimen revealed that no depletion layer had formed, indicating the niobium foil prevented sublimation of antimony at 700 C

  15. Measurement of the cosmic microwave background spectrum by the COBE FIRAS instrument

    NASA Technical Reports Server (NTRS)

    Mather, J. C.; Cheng, E. S.; Cottingham, D. A.; Eplee, R. E., Jr.; Fixsen, D. J.; Hewagama, T.; Isaacman, R. B.; Jensen, K. A.; Meyer, S. S.; Noerdlinger, P. D.

    1994-01-01

    The cosmic microwave background radiation (CMBR) has a blackbody spectrum within 3.4 x 10(exp -8) ergs/sq cm/s/sr cm over the frequency range from 2 to 20/cm (5-0.5 mm). These measurements, derived from the Far-Infrared Absolute Spectrophotomer (FIRAS) instrument on the Cosmic Background Explorer (COBE) satellite, imply stringent limits on energy release in the early universe after t approximately 1 year and redshift z approximately 3 x 10(exp 6). The deviations are less than 0.30% of the peak brightness, with an rms value of 0.01%, and the dimensionless cosmological distortion parameters are limited to the absolute value of y is less than 2.5 x 10(exp -5) and the absolute value of mu is less than 3.3 x 10(exp -4) (95% confidence level). The temperature of the CMBR is 2.726 +/- 0.010 K (95% confidence level systematic).

  16. Case Study Report #10. Ernie and Ilene Torres.

    ERIC Educational Resources Information Center

    Myers, Douglas D.; And Others

    This document presents one in a series of twenty-three case studies derived from in-depth interviews using a sampling of former participants in the Mountain-Plains program, a residential, family-based education program developed to improve the economic potential and lifestyle of selected student families in a six-state area. Each case study…

  17. The genome of black cottonwood, Populus trichocarpa (Torr.&Gray)

    SciTech Connect

    Tuskan, G.A.; DiFazio, S.; Jansson, S.; Bohlmann, J.; Grigoriev,I.; Hellsten, U.; Putnam, N.; Ralph, S.; Rombauts, S.; Salamov, A.; Schein, J.; Sterck, L.; Aerts, A.; Bhalerao, R.R.; Bhalerao, R.P.; Blaudez, D.; Boerjan, W.; Brun, A.; Brunner, A.; Busov, V.; Campbell, M.; Carlson, J.; Chalot, M.; Chapman, J.; Chen, G.-L.; Cooper, D.; Coutinho,P.M.; Couturier, J.; Covert, S.; Cronk, Q.; Cunningham, R.; Davis, J.; Degroeve, S.; Dejardin, A.; dePamphillis, C.; Detter, J.; Dirks, B.; Dubchak, I.; Duplessis, S.; Ehiting, J.; Ellis, B.; Gendler, K.; Goodstein, D.; Gribskov, M.; Grimwood, J.; Groover, A.; Gunter, L.; Hamberger, B.; Heinze, B.; Helariutta, Y.; Henrissat, B.; Holligan, D.; Holt, R.; Huang, W.; Islam-Faridi, N.; Jones, S.; Jones-Rhoades, M.; Jorgensen, R.; Joshi, C.; Kangasjarvi, J.; Karlsson, J.; Kelleher, C.; Kirkpatrick, R.; Kirst, M.; Kohler, A.; Kalluri, U.; Larimer, F.; Leebens-Mack, J.; Leple, J.-C.; Locascio, P.; Lou, Y.; Lucas, S.; Martin,F.; Montanini, B.; Napoli, C.; Nelson, D.R.; Nelson, D.; Nieminen, K.; Nilsson, O.; Peter, G.; Philippe, R.; Pilate, G.; Poliakov, A.; Razumovskaya, J.; Richardson, P.; Rinaldi, C.; Ritland, K.; Rouze, P.; Ryaboy, D.; Schmutz, J.; Schrader, J.; Segerman, B.; Shin, H.; Siddiqui,A.; Sterky, F.; Terry, A.; Tsai, C.; Uberbacher, E.; Unneberg, P.; Vahala, J.; Wall, K.; Wessler, S.; Yang, G.; Yin, T.; Douglas, C.; Marra,M.; Sandberg, G.; Van der Peer, Y.; Rokhsar, D.

    2006-09-01

    We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. Over 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event, with approximately 8,000 pairs of duplicated genes from that event surviving in the Populus genome. A second, older duplication event is indistinguishably coincident with the divergence of the Populus and Arabidopsis lineages. Nucleotide substitution, tandem gene duplication and gross chromosomal rearrangement appear to proceed substantially slower in Populus relative to Arabidopsis. Populus has more protein-coding genes than Arabidopsis, ranging on average between 1.4-1.6 putative Populus homologs for each Arabidopsis gene. However, the relative frequency of protein domains in the two genomes is similar. Overrepresented exceptions in Populus include genes associated with disease resistance, meristem development, metabolite transport and lignocellulosic wall biosynthesis.

  18. Severe Weather Guide - Mediterranean Ports - 28. Porto Torres

    DTIC Science & Technology

    1989-06-01

    Command Ship LANT (2) 31B1 Amphibious Cargo Ship LANT 31G1 Amphibious Transport Ship LANT 31H1 Amphibious Assault Ship LANT (2) 3111 Dock Landing Ship...Reports Section La Jolla, CA 92037 Oceanroutes, Inc. 680 W. Maude Ave. Sunnyvale, CA 94086-3518 Istituto Universitario Navale Facilta Di Scienze

  19. The Genome of Black Cottonwood, Populus trichocarpa (Torr. & Gray)

    NASA Astrophysics Data System (ADS)

    Tuskan, G. A.; DiFazio, S.; Jansson, S.; Bohlmann, J.; Grigoriev, I.; Hellsten, U.; Putnam, N.; Ralph, S.; Rombauts, S.; Salamov, A.; Schein, J.; Sterck, L.; Aerts, A.; Bhalerao, R. R.; Bhalerao, R. P.; Blaudez, D.; Boerjan, W.; Brun, A.; Brunner, A.; Busov, V.; Campbell, M.; Carlson, J.; Chalot, M.; Chapman, J.; Chen, G.-L.; Cooper, D.; Coutinho, P. M.; Couturier, J.; Covert, S.; Cronk, Q.; Cunningham, R.; Davis, J.; Degroeve, S.; Déjardin, A.; dePamphilis, C.; Detter, J.; Dirks, B.; Dubchak, I.; Duplessis, S.; Ehlting, J.; Ellis, B.; Gendler, K.; Goodstein, D.; Gribskov, M.; Grimwood, J.; Groover, A.; Gunter, L.; Hamberger, B.; Heinze, B.; Helariutta, Y.; Henrissat, B.; Holligan, D.; Holt, R.; Huang, W.; Islam-Faridi, N.; Jones, S.; Jones-Rhoades, M.; Jorgensen, R.; Joshi, C.; Kangasjärvi, J.; Karlsson, J.; Kelleher, C.; Kirkpatrick, R.; Kirst, M.; Kohler, A.; Kalluri, U.; Larimer, F.; Leebens-Mack, J.; Leplé, J.-C.; Locascio, P.; Lou, Y.; Lucas, S.; Martin, F.; Montanini, B.; Napoli, C.; Nelson, D. R.; Nelson, C.; Nieminen, K.; Nilsson, O.; Pereda, V.; Peter, G.; Philippe, R.; Pilate, G.; Poliakov, A.; Razumovskaya, J.; Richardson, P.; Rinaldi, C.; Ritland, K.; Rouzé, P.; Ryaboy, D.; Schmutz, J.; Schrader, J.; Segerman, B.; Shin, H.; Siddiqui, A.; Sterky, F.; Terry, A.; Tsai, C.-J.; Uberbacher, E.; Unneberg, P.; Vahala, J.; Wall, K.; Wessler, S.; Yang, G.; Yin, T.; Douglas, C.; Marra, M.; Sandberg, G.; Van de Peer, Y.; Rokhsar, D.

    2006-09-01

    We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. More than 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event; about 8000 pairs of duplicated genes from that event survived in the Populus genome. A second, older duplication event is indistinguishably coincident with the divergence of the Populus and Arabidopsis lineages. Nucleotide substitution, tandem gene duplication, and gross chromosomal rearrangement appear to proceed substantially more slowly in Populus than in Arabidopsis. Populus has more protein-coding genes than Arabidopsis, ranging on average from 1.4 to 1.6 putative Populus homologs for each Arabidopsis gene. However, the relative frequency of protein domains in the two genomes is similar. Overrepresented exceptions in Populus include genes associated with lignocellulosic wall biosynthesis, meristem development, disease resistance, and metabolite transport.

  20. Generation and release of molecular markers for Poa Arachnifera Torr

    Technology Transfer Automated Retrieval System (TEKTRAN)

    DNA based molecular markers can be utilized in a wide array of plant genetic studies, marker-trait associations, seed purity evaluations and cultivar protection. However, for the genus Poa, the use of molecular markers is limited by the current lack of informative DNA based markers. This report r...

  1. Discovery of Soft Spectral Component and Transient 22.7s Quasi Periodic Oscillations of SAX J2103.5+4545

    NASA Technical Reports Server (NTRS)

    Inam, S. C.; Baykal, A.; Swank, J.; Stark, M. J.

    2003-01-01

    XMM-Newton observed SAX J2103.5+4545 on January 6, 2003, while RXTE was monitoring the source. Using RXTE-PCA dataset between December 3, 2002 and January 29, 2003, the spin period and average spin-up rate during the XMM-Newton observations were found to be 354.7940+/-0.0008 s and (7.4 +/- 0.9) x 10(exp -13) Hz/s respectively. In the power spectrum of the 0.9-11 keV EPIC-PN lightcurve, we found quasi periodic oscillations around 0.044 Hz (22.7 s) with an rms fractional amplitude approx. 6.6 %. We interpreted this QPO feature as the Keplerian motion of inhomogeneities through the inner disk. In the X-ray spectrum, in addition to the power law component with high energy cutoff and approx. 6.4 keV fluorescent iron emission line, we discovered a soft component consistent with a blackbody emission with kT approx. 1.9 keV. The pulse phase spectroscopy of the source revealed that the blackbody flux peaked at the peak of the pulse with an emission radius approx. 0.3 km, suggesting the polar cap on the neutron star approx. 6.42 keV was shown to peak at the off-pulse phase, supporting the idea that this feature arises from fluorescent emission of the circumstellar material around the neutron star rather than the hot region in the vicinity of the neutron star polar cap.

  2. Supersonic Disk Gap Band Parachute Performance in the Wake of a Viking-Type Aeroshell from Mach 2 to 2.5

    NASA Technical Reports Server (NTRS)

    Sengupta, Anita; Roeder, James; Kelsch, Richard; Wernet, Mark; Machalick, Walt; Reuter, James; Witkowski, Al

    2008-01-01

    Supersonic wind tunnel testing of 0.813 m diameter Disk-Gap-Band parachutes is being conducted in the NASA Glenn Research Center (GRC) 10' x 10' wind-tunnel. The tests are conducted in support of the Mars Science Laboratory Parachute Decelerator System development and qualification. Four percent of full-scale parachutes were constructed similarly to the flight-article in material and construction techniques. The parachutes are attached to a 4% scale MSL entry-vehicle to simulate the free-flight configuration. The parachutes are tested from Mach 2 to 2.5 over a Reynolds number (Re) range of 1 to 3 x 10(exp 6), representative of the MSL deployment envelope. Constrained and unconstrained test configurations are investigated to quantify the effects of parachute trim, suspension line interaction, and alignment with the capsule wake. The parachute is constrained horizontally through the vent region, to measure canopy breathing and wake interaction for fixed trim angles of 0 and 10 degrees from the velocity vector. In the unconstrained configuration the parachute is permitted to trim and cone, similar to the free-flight varying its alignment relative to the entry-vehicle wake. Test diagnostics were chosen to quantify parachute performance and to provide insight into the flow field structure. An in-line load cell provided measurement of unsteady and mean drag as a function of Mach and Re. High-speed shadowgraph video of the upstream parachute flow field was used to capture bow-shock motion and stand of distance. Particle image velocimetry of the upstream parachute flow field provides spatially and temporally resolved measurement velocity and turbulent statistics. Multiple high speed video views of targets placed in the interior of the canopy enable photo-grammetric measurement of the fabric motion in time and space from reflective. High speed video is also used to document the supersonic inflation and measure trim angle, projected area, and frequency of area oscillations.

  3. Microbiological characterization of a regenerative life support system

    NASA Technical Reports Server (NTRS)

    Koenig, D. W.; Bruce, R. J.; Mishra, S. K.; Barta, D. J.; Pierson, D. L.

    1994-01-01

    A Variable Pressure Plant Growth Chamber (VPGC), at the Johnson Space Center's (JSC) ground based Regenerative Life Support Systems (RLSS) test bed, was used to produce crops of soil-grown lettuce. The crops and chamber were analyzed for microbiological diversity during lettuce growth and after harvest. Bacterial counts for the rhizosphere, spent nutrient medium, heat exchanger condensate, and atmosphere were approximately 10(exp 11) Colony Forming Units (CFU)/g, 10(exp 5) CFU/ml, 10(exp 5)CFU/ml, and 600 CFU/m sq, repectively. Pseudomonas was the predominant bacterial genus. Numbers of fungi were about 10(exp 5) CFU/g in the rhizosphere, 4-200 CFU/ml in the spent nutient medium, 110 CFU/ml in the heat exchanger condensate, and 3 CFU/cu m in the atmosphere. Fusarium and Trichoderma were the predominant fungal genera.

  4. Comparison of the impact of volcanic eruptions and aircraft emissions on the aerosol mass loading and sulfur budget in the stratosphere

    NASA Technical Reports Server (NTRS)

    Yue, Glenn K.; Poole, Lamont R.

    1992-01-01

    Data obtained by the Stratospheric Aerosol and Gas Experiment (SAGE) 1 and 2 were used to study the temporal variation of aerosol optical properties and to assess the mass loading of stratospheric aerosols from the eruption of volcanos Ruiz and Kelut. It was found that the yearly global average of optical depth at 1.0 micron for stratospheric background aerosols in 1979 was 1.16 x 10(exp -3) and in 1989 was 1.66 x 10(exp -3). The eruptions of volcanos Ruiz and Kelut ejected at least 5.6 x 10(exp 5) and 1.8 x 10(exp 5) tons of materials into the stratosphere, respectively. The amount of sulfur emitted per year from the projected subsonic and supersonic fleet is comparable to that contained in the background aerosol particles in midlatitudes from 35 deg N to 55 deg N.

  5. Quartz-enhanced photoacoustic detection of ethylene using a 10.5 μm quantum cascade laser.

    PubMed

    Wang, Zhen; Li, Zhili; Ren, Wei

    2016-02-22

    A quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor has been developed for the sensitive detection of ethylene (C2H4) at 10.5 µm using a continuous-wave distributed-feedback quantum cascade laser. At this long-wavelength infrared, the key acoustic elements of quartz tuning fork and micro-resonators were optimized to improve the detection signal-to-noise ratio by a factor of >4. The sensor calibration demonstrated an excellent linear response (R2>0.999) to C2H4 concentration at the selected operating pressure of 500 and 760 Torr. With a minimum detection limit of 50 parts per billion (ppb) achieved at an averaging time of 70 s, the sensor has been deployed for measuring the C2H4 efflux during the respiration of biological samples in an agronomic environment.

  6. Discovery of X-ray emission associated with the Gum Nebula

    NASA Technical Reports Server (NTRS)

    Leahy, D. A.; Nousek, J.; Garmire, G.

    1992-01-01

    The Gum Nebula was observed by the A-2 LED proportional counters on the HEAO-1 satellite as part of the all-sky survey. The first detection of X-ray emission associated with the Gum Nebula is reported. Soft X-ray spectra were constructed from the A-2 LED PHA data. Single temperature Raymond-Smith models were fitted to the observed spectra to yield temperature, column density and emission measure. The temperature is 6 x 10 exp 5 K, the column density 4 x 10 exp 20/sq cm, and the emission measure 5 cm exp-6 pc. The X-ray and optical properties of the Gum Nebula are consistent with a supernova remnant in the shell stage of evolution, which was the product of an energetic (3 x 10 exp 51 ergs) supernova explosion which occurred about 2 x 10 exp 6 yr ago.

  7. Observations of X-ray jets with the Yohkoh Soft X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Shibata, Kazunari; Ishido, Yoshinori; Acton, Loren W.; Strong, Keith T.; Hirayama, Tadashi; Uchida, Yutaka; Mcallister, Alan H.; Matsumoto, Ryoji; Tsuneta, Saku; Shimizu, Toshifumi

    1992-01-01

    The features of the multiple X-ray jets in the solar corona, revealed by the time series of the Yohkoh Soft X-ray Telescope images are described. The typical size of a jet was from 5 x 10 exp 3 to 4 x 10 exp 5 km, the translational velocity was 30-300 km/s, and the corresponding kinetic energy was estimated to be from 10 exp 25 to 10 exp 28 erg. Many of the jets were found to be associated with flares in X-ray bright points, emerging flux regions, or active regions, and they sometimes occurred several times from the same X-ray feature. One of the jets associated with a flaring bright point was identified as being an H-alpha surge.

  8. 4H-SiC UV Photo Detector with Large Area and Very High Specific Detectivity

    NASA Technical Reports Server (NTRS)

    Yan, Feng; Shahid, Aslam; Franz, David; Xin, Xiaobin; Zhao, Jian H.; Zhao, Yuegang; Winer, Maurice

    2004-01-01

    Pt/4H-SiC Schottky photodiodes have been fabricated with the device areas up to 1 sq cm. The I-V characteristics and photo-response spectra have been measured and analyzed. For a 5 mm x 5 mm area device leakage current of 1 x 10(exp 15)A at zero bias and 1.2 x 10(exp 14)A at -IV have been established. The quantum efficiency is over 30% from 240nm to 320nm. The specific detectivity, D(sup *), has been calculated from the directly measured leakage current and quantum efficiency data and are shown to be higher than 10(exp 15) cmHz(sup 1/2)/W from 210nm to 350nm with a peak D(sup *) of 3.6 x 10(exp 15)cmH(sup 1/2)/W at 300nm.

  9. A performance comparison of two small rocket nozzles

    NASA Technical Reports Server (NTRS)

    Arrington, Lynn A.; Reed, Brian D.; Rivera, Angel, Jr.

    1996-01-01

    An experimental study was conducted on two small rockets (110 N thrust class) to directly compare a standard conical nozzle with a bell nozzle optimized for maximum thrust using the Rao method. In large rockets, with throat Reynolds numbers of greater than 1 x 10(exp 5), bell nozzles outperform conical nozzles. In rockets with throat Reynolds numbers below 1 x 10(exp 5), however, test results have been ambiguous. An experimental program was conducted to test two small nozzles at two different fuel film cooling percentages and three different chamber pressures. Test results showed that for the throat Reynolds number range from 2 x 10(exp 4) to 4 x 10(exp 4), the bell nozzle outperformed the conical nozzle. Thrust coefficients for the bell nozzle were approximately 4 to 12 percent higher than those obtained with the conical nozzle. As expected, testing showed that lowering the fuel film cooling increased performance for both nozzle types.

  10. Development and Testing of an ISRU Soil Mechanics Vacuum Test Facility

    NASA Technical Reports Server (NTRS)

    Kleinhenz, Julie E.; Wilkinson, R. Allen

    2014-01-01

    For extraterrestrial missions, earth based testing in relevant environments is key to successful hardware development. This is true for both early component level development and system level integration. For In-Situ Resource Utilization (ISRU) on the moon, hardware must interface with the surface material, or regolith, in a vacuum environment. A relevant test environment will therefore involve a vacuum chamber with a controlled, properly conditioned bed of lunar regolith simulant. However, in earth-based granular media, such as lunar regolith simulant, gases trapped within the material pore structures and water adsorbed to all particle surfaces will release when exposed to vacuum. Early vacuum testing has shown that this gas release can occur violently, which loosens and weakens the simulant, altering the consolidation state. A mid-size chamber (3.66 m tall, 1.5 m inner diameter) at the NASA Glenn Research Center has been modified to create a soil mechanics test facility. A 0.64 m deep by 0.914 m square metric ton bed of lunar simulant was placed under vacuum using a variety of pumping techniques. Both GRC-3 and LHT-3M simulant types were used. Data obtained from an electric cone penetrometer can be used to determine strength properties at vacuum including: cohesion, friction angle, bulk density and shear modulus. Simulant disruptions, caused by off-gassing, affected the strength properties, but could be mitigated by reducing pump rate. No disruptions were observed at pressures below 2.5 Torr, regardless of the pump rate. The slow off-gassing of the soil at low pressure lead to long test times; a full week to reach 10(exp -5) Torr. Robotic soil manipulation would enable multiple ISRU hardware test within the same vacuum cycle. The feasibility of a robotically controlled auger and tamper was explored at vacuum conditions.

  11. Formation, early evolution, and gravitational stability of protoplanetary disks

    NASA Technical Reports Server (NTRS)

    Nakamoto, Taishi; Nakagawa, Yoshitsugo

    1994-01-01

    The formation, viscous evolution, and gravitational stability of protoplanetary disks are investigated. The formation process is parameterized by the angular velocity of the molecular cloud core omega, while the viscous evolution is parameterized by the viscosity parameter alpha in the disk; in this study we consider a range of (0.4-6) x 10(exp -14)/s for omega and from 10(exp -5) to 10(exp -1) for alpha. The axisymmetric gravitational stabilities of the disks are checked using Toomre's criterion. The resulting disk surface temperature distribution, (d log T(sub s)/d log R) approximately = -0.6 (R is the cylindrical radius), can be attributed to two heating sources: the viscous heating dominant in the inner disk region, and the accretion shock heating dominant in the outer disk region. This surface temperature distribution matches that observed in many disks around young stellar objects. During the infall stage, disks with alpha less than 10(exp -1.5) become gravitationally unstable independent of omega. The gravitational instabilities occur at radii ranging from 5 to 40 AU. The ratio of the disk mass to the central star mass ranges from 0.2 to 0.5 at the times of instability, about 4 x 10(exp -5) x (omega/10(exp -14)/s)(exp -0.67) yr. Most disks with low alpha and high omega become gravitationally unstable during their formation phase.

  12. Synchrotron Photoionization Mass Spectrometry Measurements of Kinetics and Product Formation in the Allyl Radical (H2CCHCH2)Self Reaction

    NASA Technical Reports Server (NTRS)

    Selby, Talitha M.; Melini, giovanni; Goulay, Fabien; Leone, Stephen R.; Fahr, Askar; Taatjes, Craig A.; Osborn, David L.

    2008-01-01

    Product channels for the self-reaction of the resonance-stabilized allyl radical, C3H5 + C3H5, have been studied with isomeric specificity at temperatures from 300-600 K and pressures from 1-6 Torr using time-resolved multiplexed photoionization mass spectrometry. Under these conditions 1,5-hexadiene was the only C6H10 product isomer detected. The lack of isomerization of the C6H10 product is in marked contrast to the C6H6 product in the related C3H3 + C3H3 reaction, and is due to the more saturated electronic structure of the C6H10 system. The disproportionation product channel, yielding allene + propene, was also detected, with an upper limit on the branching fraction relative to recombination of 0.03. Analysis of the allyl radical decay at 298 K yielded a total rate coefficient of (2.7 +/- 0.8) x 10(exp -11) cu cm/molecule/s, in good agreement with pre.vious experimental measurements using ultraviolet kinetic absorption spectroscopy and a recent theoretical determination using variable reaction coordinate transition state theory. This result provides independent indirect support for the literature value of the allyl radical ultraviolet absorption cross-section near 223 nm.

  13. Thermochemistry and Kinetics of the Cl+O2 Association Reaction

    NASA Technical Reports Server (NTRS)

    Nicovich, J. M.; Kreutter, K. D.; Shackelford, C. J.; Wine, P. H.

    1997-01-01

    Laser flash photolysis of Cl2/O2 mixtures has been employed in conjunction with Cl((sup 2)P(sub 3/2)) detection by time-resolved fluorescence spectroscopy to investigate equilibration kinetics for the reactions Cl + O2 + O is in equilibrium with ClOO + O2 at temperatures of 181-200 K and O2 pressures of 15-40 Torr. The third-order rate coefficient for the association reaction at 186.5 +/- 5.5 K is (8.9 +/- 2.9) x 10(exp -33) cm(exp 6) molecule(exp -2) s(exp -1) and the equilibrium constant (K(p)) at 185.4 K is 18.9 atm(exp -1) (factor of 1.7 uncertainty). A third law analysis of our data leads to a value for the Cl-OO bond dissociation energy of 4.76 +/- 0.49 kcal mol(exp -1).

  14. Electrical Breakdown of Anodized Structures in a Low Earth Orbital Environmental

    NASA Technical Reports Server (NTRS)

    Galofaro, J. T.; Doreswamy, C. V.; Vayner, B. V.; Snyder, D. B.; Ferguson, D. C.

    1999-01-01

    A comprehensive set of investigations involving arcing on a negatively biased anodized aluminum plate immersed in a low density argon plasma at low pressures (P(sub O), 7.5 x 10(exp -5) Torr) have been performed. These arcing experiments were designed to simulate electrical breakdown of anodized coatings in a Low Earth Orbital (LEO) environment. When electrical breakdown of an anodized layer occurs, an arc strikes, and there is a sudden flux of electrons accelerated into the ambient plasma. This event is directly followed by ejection of a quasi-neutral plasma cloud consisting of ejected material blown out of the anodized layer. Statistical analysis of plasma cloud expansion velocities have yielded a mean propagation velocity, v = (19.4 +/- 3.5) km/s. As the plasma cloud expands into the ambient plasma, energy in the form of electrical noise is generated. The radiated electromagnetic noise is detected by means of an insulated antenna immersed in the ambient plasma. The purpose of the investigations is (1) to observe and record the electromagnetic radiation spectrum resulting from the arcing process. (2) Make estimates of the travel time of the quasi-neutral plasma cloud based on fluctuations to several Langmuir probes mounted in the ambient plasma. (3) To study induced arcing between two anodized aluminum structures in close proximity.

  15. Validation of High Speed Earth Atmospheric Entry Radiative Heating from 9.5 to 15.5 km/s

    NASA Technical Reports Server (NTRS)

    Brandis, A. M.; Johnston, C. O.; Cruden, B. A.; Prabhu, D. K.

    2016-01-01

    This paper presents an overview of the analysis and measurements of equilibrium radiation obtained in the NASA Ames Research Center's Electric Arc Shock Tube (EAST) facility as a part of recent testing aimed at reaching shock velocities up to 15.5 km/s. The goal of these experiments was to measure the level of radiation encountered during high speed Earth entry conditions, such as would be relevant for an asteroid, inter-planetary or lunar return mission. These experiments provide the first spectrally and spatially resolved data for high speed Earth entry and cover conditions ranging from 9.5 to 15.5 km/s at 13.3 and 26.6 Pa (0.1 and 0.2 Torr). The present analysis endeavors to provide a validation of shock tube radiation measurements and simulations at high speed conditions. A comprehensive comparison between the spectrally resolved absolute equilibrium radiance measured in EAST and the predictive tools, NEQAIR and HARA, is presented. In order to provide a more accurate representation of the agreement between the experimental and simulation results, the integrated value of radiance has been compared across four spectral regions (VUV, UV/Vis, Vis/NIR and IR) as a function of velocity. Results have generally shown excellent agreement between the two codes and EAST data for the Vis through IR spectral regions, however, discrepancies have been identified in the VUV and parts of the UV spectral regions. As a result of the analysis presented in this paper, an updated parametric uncertainty for high speed radiation in air has been evaluated to be [9.0%, -6.3%]. Furthermore, due to the nature of the radiating environment at these high shock speeds, initial calculations aimed at modeling phenomena that become more significant with increasing shock speed have been performed. These phenomena include analyzing the radiating species emitting ahead of the shock and the increased significance of radiative cooling mechanisms.

  16. 44 CFR 5.5 - Exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Exemptions. 5.5 Section 5.5 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY GENERAL PRODUCTION OR DISCLOSURE OF INFORMATION General Provisions § 5.5 Exemptions. Requests for...

  17. 34 CFR 5.5 - Records.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Records. 5.5 Section 5.5 Education Office of the.... until 7-14-10) Definitions § 5.5 Records. As used in this part: (a) Record includes books, brochures, punch cards, magnetic tapes, paper tapes, sound recordings, maps, pamphlets, photographs, slides,...

  18. Adhesion between Polymers and Evaporated Gold and Nickel Films.

    DTIC Science & Technology

    1984-08-01

    on PTFE, about 5.49x10(exp 6) N/sq m on UHMWPE , and 6.54 x 10(exp 6) N/sq m on 6/6 nylon. The adhesion strengths for nickel films evaporated on PTFE... UHMWPE , and 6/6 nylon were found to be a factor of 1.7 higher than those for the gold-coated PTFE, UHMWPE , and 6/6 nylon. To confirm quantitatively

  19. Optical interferometer in space

    NASA Technical Reports Server (NTRS)

    Bender, Peter L.; Faller, J. E.; Hall, J. L.; Hils, D.; Stebbins, R. T.; Vincent, Mark A.

    1989-01-01

    The present design concepts for a Laser Gravitational Wave Observatory in Space are described. Laser heterodyne distance measurements are made between test masses located in three spacecraft separated by roughly 10(exp 6) km. The major technology issues are: the reduction of spurious acceleration noise for the test masses to below 2 x 10(exp -15) cm/sq sec/Hz(0.5) from 10(exp -5) to 10(exp -3) Hz; and the measurement of changes in the difference of the antenna arm lengths to 5 x 10(exp -11) cm/Hz(0.5) from 10(exp -3) to 1 Hz with high reliability. The science objectives are: to measure discrete sinusoidal gravitational wave signals from individual sources with periods of 1 second to 1 day; to measure the stochastic background due to unresolved binaries; and to search for gravitational wave pulses with periods longer than 1 sec from possible exotic sources such as gravitational collapse of very massive objects.

  20. Energetic particle-induced enhancements of stratospheric nitric acid

    NASA Technical Reports Server (NTRS)

    Aikin, Arthur C.

    1994-01-01

    Inclusion of complete ion chemistry in the calculation of minor species production during energetic particle deposition events leads to significant enhancement in the calculated nitric acid concentration during precipitation. An ionization rate of 1.2 x 10(exp 3)/cu cm/s imposed for 1 day increases HNO3 from 3 x 10(exp 5) to 6 x 10(exp 7)/cu cm at 50 km. With an ionization rate of 600 cu cm/s, the maximum HNO3 is 3 x 10(exp 7)/cu cm. Calculations which neglect negative ions predict the nitric acid will fall during precipitation events. The decay time for converting HNO3 into odd nitrogen and hydrogen is more than 1 day for equinoctial periods at 70 deg latitude. Examination of nitric acid data should yield important information on the magnitude and frequency of charged particle events.

  1. Stratospheric OClO and NO2 measured by groundbased UV/Vis-spectroscopy in Greenland in January and February 1990 and 1991

    NASA Technical Reports Server (NTRS)

    Roth, A.; Perner, D.

    1994-01-01

    Groundbased UV/Vis-spectroscopy of zenith scattered sunlight was performed at Sondre Stromfjord (Greenland) during Jan/Feb 1990 and Jan/Feb 1991. Considerable amounts of OClO were observed during both campaigns. Maximum OClO vertical column densities at 92 deg solar zenith angle (SZA) were 7.4 x 10(exp 13) molec/sq cm in 1990 and 5.7 x 10(exp 13) molec/sq cm in 1991 (chemical enhancement is included in the calculation of the air mass factor (AMF)). A threshold seems to exist for OClO detection: OClO was detected on every day when the potential vorticity at the 475 K level of potential temperature was higher than 35 x 10(exp -6)Km(exp 2)kg(exp -1)s(exp -1). NO2 vertical columns lower than 1 x 10(exp 15) molec/sq cm were frequently observed in both winters.

  2. Rosat Observations of Nine Globular Clusters

    NASA Technical Reports Server (NTRS)

    Rappaport, S.; Dewey, D.; Levine, A.; Macri, L.

    1994-01-01

    The ROSAT HRI was used to image fields around nine Galactic globular clusters that have central densities in the range of 10(exp 4) - 10(exp 5) solar mass pc(exp -3) and that had not previously been observed with the Einstein Observatory. We detected X-ray sources associated with Pal 2 and NGC 6304 with luminosities of 1.1 x 10(exp 34) ergs/s and 1.2 x 10(exp 33) ergs/s, respectively. No X-ray emission was detected from the source in Ter 6, thus confirming its transient nature. In all, there were 23 serendipitous sources found in the nine fields; none was apparently associated with any of the other seven clusters. The results are discussed in the context of low-luminosity cluster X-ray sources, in general.

  3. Model atmospheres and radiation of magnetic neutron stars. I - The fully ionized case

    NASA Technical Reports Server (NTRS)

    Shibanov, Iu. A.; Zavlin, V. E.; Pavlov, G. G.; Ventura, J.

    1992-01-01

    Model neutron star atmospheres are calculated for typical cooling stars with a strong magnetic field and effective temperatures of 10 exp 5 to 10 exp 6 K. The effect of anisotropic photon diffusion in two normal modes are examined under the assumption that the opacity is due solely to the bremsstrahlung and Thomson scattering processes under conditions of LTE that are expected to prevail at the temperatures and densities obtained. The main aspects of anisotropic photon diffusion, and an original procedure for calculating model atmospheres and emitted spectra are discussed. Representative calculated spectra are given, and it is found that the hard spectral excess characterizing the nonmagnetic case, while still present, becomes less prominent in the presence of magnetic fields in the range of 10 exp 11 to 10 exp 13 G.

  4. Design of Refractory Metal Heat Pipe Life Test Environment Chamber, Cooling System, and Radio Frequency Heating System

    NASA Technical Reports Server (NTRS)

    Martin, J. J.; Bragg-Sitton, S. M.; Reid, R. S.; Stewart, E. T.; Davis, J. D.

    2011-01-01

    A series of 16 Mo-44.5%Re alloy/sodium heat pipes will be experimentally tested to examine heat pipe aging. To support this evaluation, an environmental test chamber and a number of auxiliary subsystems are required. These subsystems include radio frequency (RF) power supplies/inductive coils, recirculation water coolant loops, and chamber gas conditioning. The heat pipes will be grouped, based on like power and gas mixture requirements, into three clusters of five units each, configured in a pentagonal arrangement. The highest powered heat pipe will be tested separately. Test chamber atmospheric purity is targeted at <0.3 ppb oxygen at an approximate operating pressure of 76 torr (.1.5 psia), maintained by active purification (oxygen level is comparable to a 10(exp -6) torr environment). Treated water will be used in two independent cooling circuits to remove .85 kW. One circuit will service the RF hardware while the other will maintain the heat pipe calorimetry. Initial procedures for the startup and operation of support systems have been identified. Each of these subsystems is outfitted with a variety of instrumentation, integrated with distributed real-time controllers and computers. A local area network provides communication between all devices. This data and control network continuously monitors the health of the test hardware, providing warning indicators followed by automatic shutdown should potentially damaging conditions develop. During hardware construction, a number of checkout tests.many making use of stainless steel prototype heat pipes that are already fabricated.will be required to verify operation.

  5. Lakshita - Mining and research hub at L5

    NASA Astrophysics Data System (ADS)

    Sharma, Navdeep; Mahajan, Aman

    2013-09-01

    In this paper, the design of an orbital space settlement named Lakshita located at L5 for 10,000 residents having area of 1 × 106 m2 has been proposed, with the aim of fulfilling mining activities and space research in micro - g. All calculations are made in the perspective of a dynamic demography which could lead to the doubling of the population in next 25 years with initial population of 4500. The settlement consists of one residential torus, one agricultural torus, industrial cylinder and two docking cylinders rotating coaxially at 1 rpm. 2.3% of the total volume of settlement is provided for two docking cylinders with 6 docking ports enabling the elastic flow of space traffic, thereby providing continuous loading and unloading of cargo and passengers. Four pressurized sliding cylinders with 5.7 × 105 m3 volume above the down surface area moving along the spokes fulfill the need of adaptation of visitors at half the gravity level of primary settlement volumes, as well provide wobble control. 1.1 × 105 torr of pressure is provided above the down surface area of the residential torus. The power generation of 400 Mw, required for the functional need of Lakshita, will be obtained through SPS located at L4. The 14 h day and 10 h night cycle will be maintained by four mirrors attached on either side from the central cylinder. The walls of the settlement will be made up of three consecutive layers of super adobe, Nextel and Kevler-49 respectively to provide radiation and debris protection. An assortment of various facilities like appropriate distribution and management of water through an intended network of pipelines, accurate management of waste within the settlement has been provided.

  6. A new thermal vacuum facility at the Martin Marietta Waterton plant

    NASA Technical Reports Server (NTRS)

    Watson, Robert N.; Bonn, John W.

    1992-01-01

    A new thermal-vacuum facility has been recently completed at the Martin Marietta Waterton plant near Denver, Colorado. The facility was designed, fabricated, installed, and tested as a turn-key project by Pitt-Des Moines Inc. and CVI Inc. The chamber has a 5.49 M by 6.10 M (18 ft by 20 ft) flat floor and a half-cylindrical roof with a diameter of 5.49 M (18 ft). Both ends of the chamber have full cross section doors, with one equipped with translating motors for horizontal motion. The chamber is provided with four 0.91 M (36 inches) cryopumps to obtain an ultimate pressure of 9 x 10(exp -8) Torr (Clean-Dry-Empty). The thermal shroud is designed to operate at a maximum of -179 C (-290 F) with an internal heat input of 316 MJ/Hr (300,000 BTU/Hr) using liquid nitrogen. The shroud is also designed to operate at any temperature between -156 C (-250 F) and 121 C (+250 F) using gaseous nitrogen, and heat or cool at a rate of 1.1 C (2 F) per minute.

  7. The Effect of Stress and TiC Coated Balls on Lubricant Lifetimes Using a Vacuum Ball-on-Plate Rolling Contact Tribometer

    NASA Technical Reports Server (NTRS)

    Jones, William R., Jr.; Jansen, Mark J.; Helmick, Larry H.; Nguyen, QuynhGiao; Wheeler, Donald R.; Boving, Hans J.

    1999-01-01

    A vacuum ball-on-plate rolling contact tribometer was used to determine the relative lifetimes of a perfluoropolyether (Krytox 143 AC) on 440C stainless steel. The effect of mean Hertzian stresses (0.75, 1.0, 1.5, and 2.0 GPa) and the use of TiC-coated balls on lubricant lifetime was studied. Other conditions included: 100 rpm, 50 micro-g of lubricant, an initial vacuum level of less than 1.0 x 10(exp -8) Torr, and room temperature (23 C). Increasing the mean Hertzian stress from 0.75 to 2.0 GPa results in an exponential decrease in lubricant lifetime for both material combinations. However, substituting a TiC ball for the 440C ball quadrupled lifetime at low stress levels (0.75 and 1.0 GPa) and doubled life at higher stresses (1.5 and 2.0 GPa). The reduced reactivity of the TiC surface with the PFPE lubricant is considered to be the reason for this enhancement. Decreasing lifetime with increasing stress levels correlated well with energy dissipation calculations.

  8. Evaluation of Boundary-Enhancement Additives for Perfluoropolyethers

    NASA Technical Reports Server (NTRS)

    Shogrin, Bradley A.; Jones, William R. , Jr.; Herrera-Fierro, Pilar; Lin, Tzuhn-Yuan; Kawa, Hajimu

    1996-01-01

    Six additives were synthesized and evaluated as boundary lubrication enhancers for perfluoropolyethers. These additives included a phosphonate, a thiophosphonate, a beta-diketone, a benzothiazole, an amide and a sulfite. These additives were evaluated in a vacuum four-ball apparatus, at a one weight percent concentration in a perfluoropolyether based on hexafluoropropene oxide. Tests were performed in vacuum (less than 5.0 x 10(exp 6) Torr), at room temperature (approx. 23 C), at an initial Hertzian stress of 3.5 GPa (200N load), and a sliding velocity of 28.8 mm/sec (100 rpm). Infrared (IR) and Raman spectroscopies were used to analyze the 440 C specimens after testing. Wear rates for each formulation were determined from the slope of wear volume as a function of sliding distance. All additives yielded reductions in mean wear rates of at least 55 percent, with the exception of the benzothiazole which had no effect. Two of the additives, an amide and a sulfite, reduced the mean wear rate by at least 80 percent. IR and Raman analysis indicated the severity of wear can be correlated to the amount of surface fluorinated polymeric acid species (R(sub f)COOH) and amorphous carbon, in and around the wear scar.

  9. Intramolecular and intermolecular N-H...C(5)H(5)(-) hydrogen bonding in magnesocene adducts of alkylamines. Implications for chemical vapor deposition using cyclopentadienyl source compounds.

    PubMed

    Xia, Aibing; Heeg, Mary Jane; Winter, Charles H

    2002-09-25

    Magnesocene adducts of alkylamines were prepared and characterized. Treatment of 3-amino-2,4-dimethylpentane, isopropylamine, tert-butylamine, benzylamine, or N-isopropylbenzylamine with magnesocene at ambient temperature in toluene afforded the amine adducts Cp2Mg(NH2CH(CH(CH3)2)2) (91%), Cp2Mg(NH2iPr) (80%), Cp2Mg(NH2tBu) (67%), Cp2Mg(NH2CH2Ph) (80%), and Cp2Mg(NH(CH(CH3)2)(CH2C6H5)) (91%). These adducts are stable at ambient temperature, and Cp2Mg(NH2CH(CH(CH3)2)2) can be sublimed at 60 degrees C/0.05 Torr without any evidence for reversion to magnesocene. The solid-state structure of Cp2Mg(NH2CH(CH(CH3)2)2) contains eta5- and eta2-cyclopentadienyl ligands, and the hydrogen atoms on the coordinated amine nitrogen atom participate in intramolecular and intermolecular hydrogen bonding to the eta2-cyclopentadienyl ligand. The observed hydrogen bonding is relevant to the path by which cyclopentadiene is eliminated from metal cyclopentadienyl CVD source compounds during film growth employing acidic element hydrides as co-reactants.

  10. Processing of U-2.5Zr-7.5Nb and U-3Zr-9Nb alloys by sintering process

    SciTech Connect

    Dos Santos, A. M. M.; Ferraz, W. B.; Lameiras, F. S.; Mazzeu, T. D. O.

    2012-07-01

    To minimize the risk of nuclear proliferation, there is worldwide interest in reducing fuel enrichment of research and test reactors. To achieve this objective while still guaranteeing criticality and cycle length requirements, there is need of developing high density uranium metallic fuels. Alloying elements such as Zr, Nb and Mo are added to uranium to improve fuel performance in reactors. In this context, the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN) is developing the U-2.5Zr-7.5Nb and U-3Zr-9Nb (weight %) alloys by the innovative process of sintering that utilizes raw materials in the form of powders. The powders were pressed at 400 MPa and then sintered under a vacuum of about 1x10{sup -4} Torr at temperatures ranging from 1050 deg. to 1500 deg.C. The densities of the alloys were measured geometrically and by hydrostatic method and the phases identified by X ray diffraction (XRD). The microstructures of the pellets were observed by scanning electron microscopy (SEM) and the alloying elements were analyzed by energy dispersive X-ray spectroscopy (EDS). The results obtained showed the fuel density to slightly increase with the sintering temperature. The highest density achieved was approximately 80% of theoretical density. It was observed in the pellets a superficial oxide layer formed during the sintering process. (authors)

  11. ROSAT X-ray observations of late-type evolved stars: On the relationship between coronal temperatures and luminosities

    NASA Technical Reports Server (NTRS)

    Maggio, A.; Sciortino, S.; Harnden, F. R., Jr.

    1994-01-01

    We present ROSAT Position Sensitive Proportional Counters (PSPC) X-ray observations of three near-solar-mass stars, in different evolutionary phases beyond the main sequence: eta Sco (F3 III-IV), iota Vir (F6 III), and HD 74772 (G5 III). All three of these nearby, presumably single stars have been detected, and we have collected enough counts to perform a detailed analysis of their soft X-ray spectra. While the X-ray spectra of eta Sco and HD 74772 can be fitted with Raymond-Smith thermal models with temperatures around 2 x 10(exp 6) K, the high signal-to-noise spectrum of iota Vir provides unambiguous evidence of a multitemperature plasma, with a two-temperature best-fit model with components at approximately 2 x 10(exp 6) K and 8 x 10(exp 6) K. Evidence of some hot plasma (T approximately 10(exp 7) K) has been also found for HD 74772. The present data, compared with spectral fitting results for other late-type stars observed with the Einstein Observatory, indicate that the low X-ray luminosity giants (L(sub x) is less than 5 x 10(exp 28) ergs/s) do not share with the higher X-ray luminosity stars of the same class the property of having substantial amount of 10(exp 7) K plasma. Moreover, our results confirm the trend of increasing X-ray luminosities with increasing coronal temperatures.

  12. Reaction of N2O5 with H2O on carbonaceous surfaces

    NASA Technical Reports Server (NTRS)

    Brouwer, L.; Rossi, M. J.; Golden, D. M.

    1986-01-01

    The heterogeneous reaction of N2O5 with commercially available ground charcoal in the absence of H2O revealed a physisorption process (gamma = 0.003), together with a redox reaction generating mostly NO. Slow HNO3 formation was the result of the interaction of N2O5 with H2O that was still adsorbed after prolonged pumping at 0.0001 torr. In the presence of H2O, the same processes with gamma = 0.005 are observed. The redox reaction dominates in the early stages of the reaction, whereas the hydrolysis gains importance later at the expense of the redox reaction. The rate law for HNO3 generation was found to be d(HNO3)/dt = k(bi)(H2O)(N2O5) with k(bi), the effective bimolecular rate constants, for 10 mg of carbon being (1.6 + or - 0.3) x 10 to the -13th cu cm/s.

  13. Thermal electron attachment to NF3, PF3, and PF5

    NASA Astrophysics Data System (ADS)

    Miller, Thomas M.; Friedman, Jeffrey F.; Stevens Miller, Amy E.; Paulson, John F.

    1995-11-01

    A flowing-afterglow Langmuir-probe apparatus was used to measure rate constants (ka) for electron attachment to NF3 and PF5 over the temperature range T = 300-550 K. Electron attachment to NF3 is dissociative and produces only F- ionic product in the temperature range studied. At room temperature, ka(NF3) = 7 ± 4 × 10-12 cm3 s-1. The temperature dependence of ka(NF3) above 340 K is characterized by an activation energy of 0.30 ± 0.06 eV. Attachment to PF5 is nondissociative in a helium buffer at pressures in the range 53-160 Pa (0.4-1.2 Torr). The rate constant ka(PF5) is 1.0 ± 0.4 × 10-10 cm3 s-1 at 300 K and is approximately temperature independent over much of the temperature range studied. PF3 does not attach electrons in this temperature range. Upper limits to ka(PF3) were determined (and attributed to impurities): ka < 1 × 10-12 cm3 s-1 at 296 K and ka < 1 × 10-10 cm3 s-1 at 550 K. The electron attachment rate constants measured in the present work are so small that corrections were required to account for electron/ion recombination contribution to the observed decay of the electron density in the plasma.

  14. 15 CFR 5.5 - Vending machines.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Vending machines. 5.5 Section 5.5... machines. (a) The income from any vending machines which are located within reasonable proximity to and are... shall be assigned to the operator of such stand. (b) If a vending machine vends articles of a...

  15. 15 CFR 5.5 - Vending machines.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false Vending machines. 5.5 Section 5.5... machines. (a) The income from any vending machines which are located within reasonable proximity to and are... shall be assigned to the operator of such stand. (b) If a vending machine vends articles of a...

  16. 15 CFR 5.5 - Vending machines.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Vending machines. 5.5 Section 5.5... machines. (a) The income from any vending machines which are located within reasonable proximity to and are... shall be assigned to the operator of such stand. (b) If a vending machine vends articles of a...

  17. 15 CFR 5.5 - Vending machines.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Vending machines. 5.5 Section 5.5... machines. (a) The income from any vending machines which are located within reasonable proximity to and are... shall be assigned to the operator of such stand. (b) If a vending machine vends articles of a...

  18. 15 CFR 5.5 - Vending machines.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Vending machines. 5.5 Section 5.5... machines. (a) The income from any vending machines which are located within reasonable proximity to and are... shall be assigned to the operator of such stand. (b) If a vending machine vends articles of a...

  19. 5 CFR 1650.5 - Returned funds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Returned funds. 1650.5 Section 1650.5 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD METHODS OF WITHDRAWING FUNDS FROM THE THRIFT SAVINGS PLAN General § 1650.5 Returned funds. If a withdrawal is returned as undeliverable, the TSP...

  20. 36 CFR 5.5 - Commercial photography.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Commercial photography. 5.5 Section 5.5 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR... motion picture may be filmed or any television production or sound track may be made, which involves...

  1. 36 CFR 5.5 - Commercial photography.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Commercial photography. 5.5 Section 5.5 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR... motion picture may be filmed or any television production or sound track may be made, which involves...

  2. 36 CFR 5.5 - Commercial photography.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Commercial photography. 5.5... COMMERCIAL AND PRIVATE OPERATIONS § 5.5 Commercial photography. (a) Motion pictures, television. Before any... Federal Regulations. (b) Still photography. The taking of photographs of any vehicle, or other articles...

  3. 5 CFR 2500.5 - Derivative classification.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Derivative classification. 2500.5 Section 2500.5 Administrative Personnel OFFICE OF ADMINISTRATION, EXECUTIVE OFFICE OF THE PRESIDENT INFORMATION SECURITY REGULATION § 2500.5 Derivative classification. The Office of Administration serves only as...

  4. 5 CFR 2500.5 - Derivative classification.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Derivative classification. 2500.5 Section 2500.5 Administrative Personnel OFFICE OF ADMINISTRATION, EXECUTIVE OFFICE OF THE PRESIDENT INFORMATION SECURITY REGULATION § 2500.5 Derivative classification. The Office of Administration serves only as...

  5. 5 CFR 2500.5 - Derivative classification.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Derivative classification. 2500.5 Section 2500.5 Administrative Personnel OFFICE OF ADMINISTRATION, EXECUTIVE OFFICE OF THE PRESIDENT INFORMATION SECURITY REGULATION § 2500.5 Derivative classification. The Office of Administration serves only as...

  6. 5 CFR 2500.5 - Derivative classification.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Derivative classification. 2500.5 Section 2500.5 Administrative Personnel OFFICE OF ADMINISTRATION, EXECUTIVE OFFICE OF THE PRESIDENT INFORMATION SECURITY REGULATION § 2500.5 Derivative classification. The Office of Administration serves only as...

  7. 5 CFR 2500.5 - Derivative classification.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Derivative classification. 2500.5 Section 2500.5 Administrative Personnel OFFICE OF ADMINISTRATION, EXECUTIVE OFFICE OF THE PRESIDENT INFORMATION SECURITY REGULATION § 2500.5 Derivative classification. The Office of Administration serves only as...

  8. 36 CFR 5.5 - Commercial photography.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Commercial photography. 5.5... COMMERCIAL AND PRIVATE OPERATIONS § 5.5 Commercial photography. (a) Motion pictures, television. Before any... Federal Regulations. (b) Still photography. The taking of photographs of any vehicle, or other articles...

  9. .beta.-glucosidase 5 (BGL5) compositions

    SciTech Connect

    Dunn-Coleman, Nigel; Goedegebuur, Frits; Ward, Michael; Yao, Jian

    2010-06-01

    The present invention provides a novel .beta.-glucosidase nucleic acid sequence, designated bgl5, and the corresponding BGL5 amino acid sequence. The invention also provides expression vectors and host cells comprising a nucleic acid sequence encoding BGL5, recombinant BGL5 proteins and methods for producing the same.

  10. Review of the High Performance Antiproton Trap (HiPAT) Experiment

    NASA Technical Reports Server (NTRS)

    Martin, James J.; Lewis, Raymond A.; Pearson, J. Boise; Sims, W. Herb; Chakrabarti, Suman; Fant, Wallace E.; McDonald, Stan

    2003-01-01

    Many space propulsion concepts exist that use matter-antimatter reactions. Current antiproton production rates are enough to conduct proof-of-principle evaluation of these concepts. One enabling technology for such experiments is portable storage of low energy antiprotons, to transport antiprotons to experimental facilities. To address this need, HiPAT is being developed, with a design goal of containing 10(exp 12) particles for up to 18 days. HiPAT is a Penning-Malmberg trap with a 4 Tesla superconductor, 20kV electrodes, radio frequency (RF) network, and 10(exp -13) Torr vacuum. 'Normal' matter is being used to evaluate the system. An electron beam ionizes background gas in situ, and particle beams are captured dynamically. The experiment examines ion storage lifetimes, RF plasma diagnostics, charge exchange with background gases, and dynamic ion beam capture.

  11. Space Power Facility Readiness for Space Station Power System Testing

    NASA Technical Reports Server (NTRS)

    Smith, Roger L.

    1995-01-01

    This document provides information which shows that the NASA Lewis Research Center's Space Power Facility (SPF) will be ready to execute the Space Station electric power system thermal vacuum chamber testing. The SPF is located at LeRC West (formerly the Plum Brook Station), Sandusky, Ohio. The SPF is the largest space environmental chamber in the world, having an inside horizontal diameter of 100 ft. and an inside height at the top of the hemisphere of 122 ft. The vacuum system can achieve a pressure lower than 1 x 10(exp -5) Torr. The cryoshroud, cooled by gaseous nitrogen, can reach a temperature of -250 F, and is 80 ft. long x 40 ft. wide x 22 ft. high. There is access to the chamber through two 50 ft. x 50 ft. doors. Each door opens into an assembly area about 150 ft. long x 70 ft. wide x 80 ft. high. Other available facilities are offices, shop area, data acquisition system with 930 pairs of hard lines, 7 megawatts of power to chamber, 245K gal. liquid nitrogen storage, cooling tower, natural gas, service air, and cranes up to 25 tons.

  12. Helium Pressure Shift of the Hyperfine Clock Transition in Hg-201(+)

    NASA Technical Reports Server (NTRS)

    Larigani, S. Taghavi; Burt, E. A.; Tjoelker, R. L.

    2010-01-01

    There are two stable odd isotopes of mercury with singly ionized hyperfine structure suitable for a microwave atomic clock: Hg-199(+) and Hg-201(+). We are investigating the viability of a trapped ion clock based on Hg-201(+) in a configuration that uses a buffer gas to increase ion loading efficiency and counter ion heating from rf trapping fields. Traditionally, either helium or neon is used as the buffer gas at approx. 10(exp -5) torr to confine mercury ions near room temperature. In addition to the buffer gas, other residual background gasses such as H2O, N2, O2, CO, CO2, and CH2 may be present in trace quantities. Collisions between trapped ions and buffer gas or background gas atoms/molecules produce a momentary shift of the ion clock transition frequency and constitute one of the largest systematic effects in this type of clock. Here we report an initial measurement of the He pressure shift in Hg-201(+) and compare this to Hg-199(+).

  13. Photoemission Experiments for Charge Characteristics of Individual Dust Grains

    NASA Technical Reports Server (NTRS)

    Abbas, M. M.; Craven, P. D.; Spann, J. F.; West, E.; Pratico, J.; Tankosic, D.; Venturini, C. C.; Six, N. Frank (Technical Monitor)

    2001-01-01

    Photoemission experiments with UV radiation have been performed to investigate the microphysics and charge characteristics of individual isolated dust grains of various compositions and sizes by using the electrodynamic balance facility at NASA Marshall Space Flight Center. Dust particles of 2-10 gm diameter are levitated in a vacuum chamber at pressures approximately 10(exp-5) torr and exposed to a collimated beam of UV radiation in the 120-200 nm spectral range from a deuterium lamp source with a MgF2 window. A monochromator is used to select the UV wavelength with a spectral resolution of 8 nm. The electrodynamic facility permits measurements of the charge and diameters of particles of known composition, and monitoring of photoemission rates with the incident UV radiation. Experiments have been conducted on test particles of silica and polystyrene to determine the photoelectric yields and surface equilibrium potentials when exposed to UV radiation. A brief description of an experimental procedure for photoemission studies is given and some preliminary laboratory measurements of the photoelectric yields of individual dust particles are presented.

  14. Photoemission Experiments for Charge Characteristics of Individual Dust Grains

    NASA Technical Reports Server (NTRS)

    Abbas, M. M.; Spann, James F., Jr.; Craven, Paul D.; West, E.; Pratico, Jared; Scheianu, D.; Tankosic, D.; Venturini, C. C.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Photoemission experiments with UV radiation have been performed to investigate the microphysics and charge characteristics of individual isolated dust grains of various compositions and sizes by using the electrodynamic balance facility at NASA Marshall Space Flight Center. Dust particles of 1 - 100 micrometer diameter are levitated in a vacuum chamber at pressures approx. 10(exp -5) torr and exposed to a collimated beam of UV radiation in the 120-300 nanometers spectral range from a deuterium lamp source with a MgF2 window. A monochromator is used to select the UV radiation wavelength with a spectral resolution of 8 nanometers. The electrodynamic facility permits measurements of the charge and diameters of particles of known composition, and monitoring of photoemission rates with the incident UV radiation. Experiments have been conducted on Al2O3 and silicate particles, and in particular on JSC-1 Mars regolith simulants, to determine the photoelectron yields and surface equilibrium potentials of dust particles when exposed to UV radiation in the 120-250 micrometers spectral range. A brief discussion of the experimental procedure, the results of photoemission experiments, and comparisons with theoretical models will be presented.

  15. Extraction of Thermal Performance Values from Samples in the Lunar Dust Adhesion Bell Jar

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Siamidis, John; Larkin, Elizabeth M. G.

    2010-01-01

    A simulation chamber has been developed to test the performance of thermal control surfaces under dusty lunar conditions. The lunar dust adhesion bell jar (LDAB) is a diffusion pumped vacuum chamber (10(exp -8) Torr) built to test material samples less than about 7 cm in diameter. The LDAB has the following lunar dust simulant processing capabilities: heating and cooling while stirring in order to degas and remove adsorbed water; RF air-plasma for activating the dust and for organic contaminant removal; RF H/He-plasma to simulate solar wind; dust sieving system for controlling particle sizes; and a controlled means of introducing the activated dust to the samples under study. The LDAB is also fitted with an in situ Xe arc lamp solar simulator, and a cold box that can reach 30 K. Samples of thermal control surfaces (2.5 cm diameter) are introduced into the chamber for calorimetric evaluation using thermocouple instrumentation. The object of this paper is to present a thermal model of the samples under test conditions and to outline the procedure to extract the absorptance, emittance, and thermal efficiency from the pristine and sub-monolayer dust covered samples.

  16. Extraction of Thermal Performance Values from Samples in the Lunar Dust Adhesion Bell Jar

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Siamidis, John; Larkin, Elizabeth M. G.

    2008-01-01

    A simulation chamber has been developed to test the performance of thermal control surfaces under dusty lunar conditions. The lunar dust adhesion bell jar (LDAB) is a diffusion pumped vacuum chamber (10(exp -8) Torr) built to test material samples less than about 7 cm in diameter. The LDAB has the following lunar dust simulant processing capabilities: heating and cooling while stirring in order to degas and remove adsorbed water; RF air-plasma for activating the dust and for organic contaminant removal; RF H/He-plasma to simulate solar wind; dust sieving system for controlling particle sizes; and a controlled means of introducing the activated dust to the samples under study. The LDAB is also fitted with an in situ Xe arc lamp solar simulator, and a cold box that can reach 30 K. Samples of thermal control surfaces (2.5 cm diameter) are introduced into the chamber for calorimetric evaluation using thermocouple instrumentation. The object of this paper is to present a thermal model of the samples under test conditions and to outline the procedure to extract the absorptance, emittance, and thermal efficiency from the pristine and sub-monolayer dust covered samples.

  17. Radiance Measurement for Low Density Mars Entry

    NASA Technical Reports Server (NTRS)

    Cruden, Brett A.

    2012-01-01

    We report measurements of radiance behind a shock wave in Martian simulant (96% CO2, 4% N2) atmosphere at conditions relevant for aerodynamic decelerators. Shock waves are generated in the NASA Ames Electric Arc Shock Tube (EAST) facility at velocities from 6-8 km/s and freestream densities from 1.2-5.9 x 10(exp -4) kilograms per cubic meter (0.05-0.25 Torr, corresponding to 35-50 km altitude). Absolute radiance is measured as a function of wavelength and position in the shock. Radiance measurements extend from the vacuum ultraviolet to near infrared (120-1650 nm). As at higher density/velocity, radiation is dominate by CO 4th positive radiation in the vacuum ultraviolet, though CN contribution is also significant. At most low density conditions, the shock does not relax to equilibrium over several centimeters. A small number of measurements in the mid-infrared were performed to quantify radiation from the fundamental vibrational transition in CO, and this is found to be a minor contributor to the overall radiance at these speeds. Efforts to extend test time and reliability in the 60 cm (24) shock tube will be discussed in the full paper.

  18. Performance of the Satellite Test Assistant Robot in JPL's Space Simulation Facility

    NASA Technical Reports Server (NTRS)

    Mcaffee, Douglas; Long, Mark; Johnson, Ken; Siebes, Georg

    1995-01-01

    An innovative new telerobotic inspection system called STAR (the Satellite Test Assistant Robot) has been developed to assist engineers as they test new spacecraft designs in simulated space environments. STAR operates inside the ultra-cold, high-vacuum, test chambers and provides engineers seated at a remote Operator Control Station (OCS) with high resolution video and infrared (IR) images of the flight articles under test. STAR was successfully proof tested in JPL's 25-ft (7.6-m) Space Simulation Chamber where temperatures ranged from +85 C to -190 C and vacuum levels reached 5.1 x 10(exp -6) torr. STAR's IR Camera was used to thermally map the entire interior of the chamber for the first time. STAR also made several unexpected and important discoveries about the thermal processes occurring within the chamber. Using a calibrated test fixture arrayed with ten sample spacecraft materials, the IR camera was shown to produce highly accurate surface temperature data. This paper outlines STAR's design and reports on significant results from the thermal vacuum chamber test.

  19. Modeling of life limiting phenomena in the discharge chamber of an electron bombardment ion thruster

    NASA Technical Reports Server (NTRS)

    Handoo, Arvind K.; Ray, Pradosh K.

    1991-01-01

    An experimental facility to study the low energy sputtering of metal surfaces with ions produced by an ion gun is described. The energy of the ions ranged from 10 to 500 eV. Cesium ions with energies from 100 to 500 eV were used initially to characterize the operation of the ion gun. Next, argon and xenon ions were used to measure the sputtering yields of cobalt (Co), Cadmium (Cd), and Chromium (Cr) at an operating temperature of 2x10(exp -5) Torr. The ion current ranged from 0.0135 micro-A at 500 eV. The targets were electroplated on a copper substrate. The surface density of the electroplated material was approx. 50 micro-g/sq cm. The sputtered atoms were collected on an aluminum foil surrounding the target. Radioactive tracers were used to measure the sputtering yields. The sputtering yields of Cr were found to be much higher than those of Co and Cd. The yields of Co and Cd were comparable, with Co providing the higher yields. Co and Cd targets were observed to sputter at energies as low as 10 eV for both argon and xenon ions. The Cr yields could not be measured below 20 eV for argon ions and 15 eV for xenon ions. On a linear scale the yield energy curves near the threshold energies exhibit a concave nature.

  20. 43 CFR 1610.5-5 - Amendment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., DEPARTMENT OF THE INTERIOR GENERAL MANAGEMENT (1000) PLANNING, PROGRAMMING, BUDGETING Resource Management Planning § 1610.5-5 Amendment. A resource management plan may be changed through amendment. An...

  1. 5 CFR 1653.5 - Payment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Payment. 1653.5 Section 1653.5 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD COURT ORDERS AND LEGAL PROCESSES AFFECTING... other, or a legal separation is terminated, a new court order will be required to prevent...

  2. 5 CFR 1320.5 - General requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false General requirements. 1320.5 Section 1320.5 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES CONTROLLING PAPERWORK... use of automated, electronic, mechanical, or other technological collection techniques or other...

  3. 41 CFR 51-5.5 - Prices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... in § 51-5.6. (c) Price changes for commodities and services shall usually apply to orders received by... the views of the contracting activity, the Committee may make price changes applicable to orders... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Prices. 51-5.5 Section...

  4. Rate Constant and RRKM Product Study for the Reaction Between CH3 and C2H3 at T = 298K

    NASA Technical Reports Server (NTRS)

    Thorn, R. Peyton, Jr.; Payne, Walter A., Jr.; Chillier, Xavier D. F.; Stief, Louis J.; Nesbitt, Fred L.; Tardy, D. C.

    2000-01-01

    The total rate constant k1 has been determined at P = 1 Torr nominal pressure (He) and at T = 298 K for the vinyl-methyl cross-radical reaction CH3 + C2H3 yields products. The measurements were performed in a discharge flow system coupled with collision-free sampling to a mass spectrometer operated at low electron energies. Vinyl and methyl radicals were generated by the reactions of F with C2H4 and CH4, respectively. The kinetic studies were performed by monitoring the decay of C2H3 with methyl in excess, 6 < |CH3|(sub 0)/|C2H3|(sub 0) < 21. The overall rate coefficient was determined to be k1(298 K) = (1.02 +/- 0.53)x10(exp -10) cubic cm/molecule/s with the quoted uncertainty representing total errors. Numerical modeling was required to correct for secondary vinyl consumption by reactions such as C2H3 + H and C2H3 + C2H3. The present result for k1 at T = 298 K is compared to two previous studies at high pressure (100-300 Torr He) and to a very recent study at low pressure (0.9-3.7 Torr He). Comparison is also made with the rate constant for the similar reaction CH3 + C2H5 and with a value for k1 estimated by the geometric mean rule employing values for k(CH3 + CH3) and k(C2H3 + C2H3). Qualitative product studies at T = 298 K and 200 K indicated formation of C3H6, C2H2, and C2H5 as products of the combination-stabilization, disproportionation, and combination-decomposition channels, respectively, of the CH3 + C2H3 reaction. We also observed the secondary C4H8 product of the subsequent reaction of C3H5 with excess CH3; this observation provides convincing evidence for the combination-decomposition channel yielding C3H5 + H. RRKM calculations with helium as the deactivator support the present and very recent experimental observations that allylic C-H bond rupture is an important path in the combination reaction. The pressure and temperature dependencies of the branching fractions are also predicted.

  5. Comparative Studies for the Sodium and Potassium Atmospheres of the Moon and Mercury

    NASA Technical Reports Server (NTRS)

    Smyth, William H.

    1999-01-01

    A summary discussion of recent sodium and potassium observations for the atmospheres of the Moon and Mercury is presented with primary emphasis on new full-disk images that have become available for sodium. For the sodium atmosphere, image observations for both the Moon and Mercury are fitted with model calculations (1) that have the same source speed distribution, one recently measured for electron-stimulated desorption and thought to apply equally well to photon-stimulated desorption, (2) that have similar average surface sodium fluxes, about 2.8 x 10(exp 5) to 8.9 x 10(exp 5) atoms cm(exp -2)s(exp -1) for the Moon and approximately 3.5 x 10(exp 5) to 1.4 x 10(exp 6) atoms cm(exp -2)s(exp -1) for Mercury, but (3) that have very different distributions for the source surface area. For the Moon, a sunlit hemispherical surface source of between approximately 5.3 x 10(exp 22) to 1.2 x 10(exp 23) atoms/s is required with a spatial dependence at least as sharp as the square of the cosine of the solar zenith angle. For Mercury, a time dependent source that varies from 1.5 x 10(exp 22) to 5.8 x l0(exp 22) atoms/s is required which is confined to a small surface area located at, but asymmetrically distributed about, the subsolar point. The nature of the Mercury source suggest that the planetary magnetopause near the subsolar point acts as a time varying and partially protective shield through which charged particles may pass to interact with and liberate gas from the planetary surface. Suggested directions for future research activities are discussed.

  6. Initial Thrust Measurements of Marshall's Ion-ioN Thruster

    NASA Technical Reports Server (NTRS)

    Caruso, Natalie R. S.; Scogin, Tyler; Liu, Thomas M.; Walker, Mitchell L. R.; Polzin, Kurt A.; Dankanich, John W.

    2015-01-01

    Electronegative ion thrusters are a variation of traditional gridded ion thruster technology differentiated by the production and acceleration of both positive and negative ions. Benefits of electronegative ion thrusters include the elimination of lifetime-limiting cathodes from the thruster architecture and the ability to generate appreciable thrust from both charge species. While much progress has been made in the development of electronegative ion thruster technology, direct thrust measurements are required to unambiguously demonstrate the efficacy of the concept and support continued development. In the present work, direct thrust measurements of the thrust produced by the MINT (Marshall's Ion-ioN Thruster) are performed using an inverted-pendulum thrust stand in the High-Power Electric Propulsion Laboratory's Vacuum Test Facility-1 at the Georgia Institute of Technology with operating pressures ranging from 4.8 x 10(exp -5) and 5.7 x 10(exp -5) torr. Thrust is recorded while operating with a propellant volumetric mixture ratio of 5:1 argon to nitrogen with total volumetric flow rates of 6, 12, and 24 sccm (0.17, 0.34, and 0.68 mg/s). Plasma is generated using a helical antenna at 13.56 MHz and radio frequency (RF) power levels of 150 and 350 W. The acceleration grid assembly is operated using both sinusoidal and square waveform biases of +/-350 V at frequencies of 4, 10, 25, 125, and 225 kHz. Thrust is recorded for two separate thruster configurations: with and without the magnetic filter. No thrust is discernable during thruster operation without the magnetic filter for any volumetric flow rate, RF forward Power level, or acceleration grid biasing scheme. For the full thruster configuration, with the magnetic filter installed, a brief burst of thrust of approximately 3.75 mN +/- 3 mN of error is observed at the start of grid operation for a volumetric flow rate of 24 sccm at 350 W RF power using a sinusoidal waveform grid bias at 125 kHz and +/- 350 V

  7. Cryogenic Insulation System for Soft Vacuum

    NASA Technical Reports Server (NTRS)

    Augustynowicz, S. D.; Fesmire, J. E.

    1999-01-01

    The development of a cryogenic insulation system for operation under soft vacuum is presented in this paper. Conventional insulation materials for cryogenic applications can be divided into three levels of thermal performance, in terms of apparent thermal conductivity [k-value in milliwatt per meter-kelvin (mW/m-K)]. System k-values below 0.1 can be achieved for multilayer insulation operating at a vacuum level below 1 x 10(exp -4) torr. For fiberglass or powder operating below 1 x 10(exp -3) torr, k-values of about 2 are obtained. For foam and other materials at ambient pressure, k-values around 30 are typical. New industry and aerospace applications require a versatile, robust, low-cost thermal insulation with performance in the intermediate range. The target for the new composite insulation system is a k-value below 4.8 mW/m-K (R-30) at a soft vacuum level (from 1 to 10 torr) and boundary temperatures of approximately 77 and 293 kelvin (K). Many combinations of radiation shields, spacers, and composite materials were tested from high vacuum to ambient pressure using cryostat boiloff methods. Significant improvement over conventional systems in the soft vacuum range was demonstrated. The new layered composite insulation system was also shown to provide key benefits for high vacuum applications as well.

  8. High Resolution and Large Dynamic Range Resonant Pressure Sensor Based on Q-Factor Measurement

    NASA Technical Reports Server (NTRS)

    Gutierrez, Roman C. (Inventor); Stell, Christopher B. (Inventor); Tang, Tony K. (Inventor); Vorperian, Vatche (Inventor); Wilcox, Jaroslava (Inventor); Shcheglov, Kirill (Inventor); Kaiser, William J. (Inventor)

    2000-01-01

    A pressure sensor has a high degree of accuracy over a wide range of pressures. Using a pressure sensor relying upon resonant oscillations to determine pressure, a driving circuit drives such a pressure sensor at resonance and tracks resonant frequency and amplitude shifts with changes in pressure. Pressure changes affect the Q-factor of the resonating portion of the pressure sensor. Such Q-factor changes are detected by the driving/sensing circuit which in turn tracks the changes in resonant frequency to maintain the pressure sensor at resonance. Changes in the Q-factor are reflected in changes of amplitude of the resonating pressure sensor. In response, upon sensing the changes in the amplitude, the driving circuit changes the force or strength of the electrostatic driving signal to maintain the resonator at constant amplitude. The amplitude of the driving signals become a direct measure of the changes in pressure as the operating characteristics of the resonator give rise to a linear response curve for the amplitude of the driving signal. Pressure change resolution is on the order of 10(exp -6) torr over a range spanning from 7,600 torr to 10(exp -6) torr. No temperature compensation for the pressure sensor of the present invention is foreseen. Power requirements for the pressure sensor are generally minimal due to the low-loss mechanical design of the resonating pressure sensor and the simple control electronics.

  9. THERM 5 / WINDOW 5 NFRC simulation manual

    SciTech Connect

    Mitchell, Robin; Kohler, Christian; Arasteh, Dariush; Carmody, John; Huizenga, Charlie; Curcija, Dragan

    2003-06-01

    This document, the ''THERM 5/WINDOW 5 NFRC Simulation Manual', discusses how to use the THERM and WINDOW programs to model products for NFRC certified simulations and assumes that the user is already familiar with those programs. In order to learn how to use these programs, it is necessary to become familiar with the material in both the ''THERM User's Manual'' and the ''WINDOW User's Manual''. In general, this manual references the User's Manuals rather than repeating the information. If there is a conflict between either of the User Manual and this ''THERM 5/''WINDOW 5 NFRC Simulation Manual'', the ''THERM 5/WINDOW 5 NFRC Simulation Manual'' takes precedence. In addition, if this manual is in conflict with any NFRC standards, the standards take precedence. For example, if samples in this manual do not follow the current taping and testing NFRC standards, the standards not the samples in this manual, take precedence.

  10. Reactions of Fe+ coordinated to the [pi]-donating ligands C2H4, c-C5H5, C6H6 and C60 with N2O and CO: probing the bonding in (C60)Fe+

    NASA Astrophysics Data System (ADS)

    Baranov, Vladimir; Bohme, Diethard K.

    1995-11-01

    Experimental results are reported for gas-phase reactions of Fe+ coordinated to the [pi]-donating ligands C2H4, c-C5H5, C6H6 and C60 with N2O and CO. Reaction rate coefficients and product distributions were measured with the selected-ion flow tube (SIFT) technique operating at 294 ± 3 K and a helium buffer gas pressure of 0.35 ± 0.01 Torr. The measurements provide intrinsic efficiencies for the primary and higher-order ligation of these XFe+ cations with CO and N2O and their corresponding coordination numbers. The coordination numbers are consistent with known ground state electronic structures. Many of the ligated ions were synthesized by ion/molecule ligation reactions in the gas phase for the first time, including XFe(CO)n+ and XFe(N2O)+ with X = C2H4, c-C5H5 and C6H6, (C60)Fe(N2O)+, (C60)FeO+ and (C60)FeO(N2O)+. Also, the measurements provided an experimental assessment of the mode of bonding in (C60)Fe+.

  11. Pursuing reliable thermal analysis techniques for energetic materials: decomposition kinetics and thermal stability of dihydroxylammonium 5,5'-bistetrazole-1,1'-diolate (TKX-50).

    PubMed

    Muravyev, Nikita V; Monogarov, Konstantin A; Asachenko, Andrey F; Nechaev, Mikhail S; Ananyev, Ivan V; Fomenkov, Igor V; Kiselev, Vitaly G; Pivkina, Alla N

    2016-12-21

    Thermal decomposition of a novel promising high-performance explosive dihydroxylammonium 5,5'-bistetrazole-1,1'-diolate (TKX-50) was studied using a number of thermal analysis techniques (thermogravimetry, differential scanning calorimetry, and accelerating rate calorimetry, ARC). To obtain more comprehensive insight into the kinetics and mechanism of TKX-50 decomposition, a variety of complementary thermoanalytical experiments were performed under various conditions. Non-isothermal and isothermal kinetics were obtained at both atmospheric and low (up to 0.3 Torr) pressures. The gas products of thermolysis were detected in situ using IR spectroscopy, and the structure of solid-state decomposition products was determined by X-ray diffraction and scanning electron microscopy. Diammonium 5,5'-bistetrazole-1,1'-diolate (ABTOX) was directly identified to be the most important intermediate of the decomposition process. The important role of bistetrazole diol (BTO) in the mechanism of TKX-50 decomposition was also rationalized by thermolysis experiments with mixtures of TKX-50 and BTO. Several widely used thermoanalytical data processing techniques (Kissinger, isoconversional, formal kinetic approaches, etc.) were independently benchmarked against the ARC data, which are more germane to the real storage and application conditions of energetic materials. Our study revealed that none of the Arrhenius parameters reported before can properly describe the complex two-stage decomposition process of TKX-50. In contrast, we showed the superior performance of the isoconversional methods combined with isothermal measurements, which yielded the most reliable kinetic parameters of TKX-50 thermolysis. In contrast with the existing reports, the thermal stability of TKX-50 was determined in the ARC experiments to be lower than that of hexogen, but close to that of hexanitrohexaazaisowurtzitane (CL-20).

  12. Environmental Perturbations Caused by the Impacts of Asteroids and Comets

    NASA Technical Reports Server (NTRS)

    Toon, Owen B.; Zahnle, Kevin; Morrison, David; Turco, Richard; Covey, Curt

    1997-01-01

    We review the major mechanisms proposed to cause extinctions at the Cretaceous-Tertiary geological boundary following an asteroid impact. We then discuss how the proposed extinction may relate to the impact of asteroids or comets in general. We discuss the limitations of these mechanisms in terms of the spatial scale that may be affected, and the time scale over which the effects may last. Our goal is to provide relatively simple prescriptions for evaluating the importance of colliding objects having a range of energies and compositions. We also identify the many uncertainties concerning the environmental effects of impacts. We conclude that, for impact energies below about 10(exp 4) Mts (megatons of TNT equivalent) - i.e., impact frequencies less than in 6 x 10(exp 4) yr, corresponding to comets and asteroids with diameters smaller than about 400 m and 650 m, respectively - blast damage, earthquakes, and fires should be important on a scale of 10(exp 4) or 10(exp 5) km (exp 2), which corresponds to the area damaged in many natural disasters of recent history. However, tsunami could be more damaging, flooding a kilometer of coastal plane over entire ocean basins. In the energy range of 10(exp 4) to 10 (exp 5) Mts (intervals up to 3 x 10(exp 5) yr; comets and asteroids with sizes up to 800 m and 1.5 km, respectively) water vapor injections and ozone loss become significant on the global scale. In the submicrometer dust injection fraction from the pulverized target material is much higher than is presently thought to be most likely, then dust injection could be important in this energy range.

  13. Technical Evaluation Motor no. 5 (TEM-5)

    NASA Technical Reports Server (NTRS)

    Cook, M.

    1990-01-01

    Technical Evaluation Motor No. 5 (TEM-5) was static test fired at the Thiokol Corporation Static Test Bay T-97. TEM-5 was a full scale, full duration static test fire of a high performance motor (HPM) configuration solid rocket motor (SRM). The primary purpose of TEM static tests is to recover SRM case and nozzle hardware for use in the redesigned solid rocket motor (RSRM) flight program. Inspection and instrumentation data indicate that the TEM-5 static test firing was successful. The ambient temperature during the test was 41 F and the propellant mean bulk temperature (PMBT) was 72 F. Ballistics performance values were within the specified requirements. The overall performance of the TEM-5 components and test equipment was nominal. Dissembly inspection revealed that joint putty was in contact with the inner groove of the inner primary seal of the ignitor adapter-to-forward dome (inner) joint gasket; this condition had not occurred on any previous static test motor or flight RSRM. While no qualification issues were addressed on TEM-5, two significant component changes were evaluated. Those changes were a new vented assembly process for the case-to-nozzle joint and the installation of two redesigned field joint protection systems. Performance of the vented case-to-nozzle joint assembly was successful, and the assembly/performance differences between the two field joint protection system (FJPS) configurations were compared.

  14. Use of space ultra-vacuum for high quality semiconductor thin film growth

    NASA Technical Reports Server (NTRS)

    Ignatiev, A.; Sterling, M.; Sega, R. M.

    1992-01-01

    The utilization of space for materials processing is being expanded through a unique concept of epitaxial thin film growth in the ultra-vacuum of low earth orbit (LEO). This condition can be created in the wake of an orbiting space vehicle; and assuming that the vehicle itself does not pertub the environment, vacuum levels of better than 10 exp -14 torr can be attained. This vacuum environment has the capacity of greatly enhancing epitaxial thin film growth and will be the focus of experiments conducted aboard the Wake Shield Facility (WSF) currently being developed by the Space Vacuum Epitaxy Center (SVEC), Industry, and NASA.

  15. Absolute intensities for the Q-branch of the 3 nu(sub 2) (-) nu(sub 1) (465.161/cm) band of nitrous oxide

    NASA Technical Reports Server (NTRS)

    Sirota, J. Marcos; Reuter, Dennis C.

    1993-01-01

    The absolute intensities of four lines, Q 15-Q 18 in the 03(sup 1)0-10(sup 0)0 band, of N2O have been measured using a tunable diode laser spectrometer at temperatures between 380 and 420 K and pressures between 4 and 15 torr. Even though these transitions are weak and produced only about 2% of absorption at the line center for a pathlength of 52 m, they were measured with a signal to noise ratio of about 20 due to the high sensitivity of the instrument. The band strength derived is 1.03 x 10(exp -24) cm/molec at 296 K.

  16. Low energy sputtering of cobalt by cesium ions

    NASA Technical Reports Server (NTRS)

    Handoo, A.; Ray, Pradosh K.

    1989-01-01

    An experimental facility to investigate low energy (less than 500 eV) sputtering of metal surfaces with ions produced by an ion gun is described. Results are reported on the sputtering yield of cobalt by cesium ions in the 100 to 500 eV energy range at a pressure of 1 times 10(exp -6) Torr. The target was electroplated on a copper substrate. The sputtered atoms were collected on a cobalt foil surrounding the target. Co-57 was used as a tracer to determine the sputtering yield.

  17. Scaling of Electron Beam Switches

    DTIC Science & Technology

    1983-06-01

    BEAM CURRENT DENSITY (AFTER FOIL). N2 760 Torr N2+0.038Torr C3F8 ~15 N2+0. l’T orr C3F8 N2+0. 124Torr C2F6 Ql L L 310 \\ ~ \\\\ ~ 5 h...Time [sec] FIG 5. CURRENT DECAYS FOR NITROGEN AND NITROGEN WITH ADDED ATTACHING GASES. CH4 760 Torr CH4+0. lTorr C2F6 CH4+0. lTorr C3F8 CH4

  18. STAT5 acetylation

    PubMed Central

    Kosan, Christian; Ginter, Torsten; Heinzel, Thorsten; Krämer, Oliver H

    2013-01-01

    The cytokine-inducible transcription factors signal transducer and activator of transcription 5A and 5B (STAT5A and STAT5B) are important for the proper development of multicellular eukaryotes. Disturbed signaling cascades evoking uncontrolled expression of STAT5 target genes are associated with cancer and immunological failure. Here, we summarize how STAT5 acetylation is integrated into posttranslational modification networks within cells. Moreover, we focus on how inhibitors of deacetylases and tyrosine kinases can correct leukemogenic signaling nodes involving STAT5. Such small molecules can be exploited in the fight against neoplastic diseases and immunological disorders. PMID:24416653

  19. Is HL Tauri and FU Orionis system in quiescence?

    NASA Technical Reports Server (NTRS)

    Lin, D. N. C.; Hayashi, M.; Bell, K. R.; Ohashi, N.

    1994-01-01

    A recent Nobeyama map of HL Tau reveals that gas is infalling in a flattened region approximately 1400 AU around the central star. The apparent motion of the gas provides the necessary condition for the formation of a Keplerian disk with a radius comparable to the size of the primordial solar nebula. The inferred mass infall rate onto the disk is approximately equal to 5 x 10(exp -6) solar mass/yr, which greatly exceeds the maximum estimate of the accretion rate onto the central star (approximately 7 x 10(exp -7) solar mass/yr). Consequently, mass must currently be accumulating in the disk. The estimated age and disk mass of HL Tau suggest that the accumulated matter has been flushed repeatedly on a timescale less than 10(exp 4) yr. Based on the similarites between their evolution patterns, we propose that HL Tau is an FU Orionis system in quiescence. In addition to HL Tau, 14 out of 86 pre-main-sequence stars in the Taurus-Auriga dark clouds have infrared luminosities much greater than their otherwise normal extinction-corrected stellar luminosities. These sources also tend to have flat spectra which may be due to the reprocessing of radiation by dusty, flattened, collapsing envelopes with infall rates a few 10(exp -6) solar mass/yr. Such rates are much larger than estimated central accretion rates for these systems, which suggests that mass must also be accumulating in these disks. If these sources are FU Orionis stars in quiescence, similar to HL Tau, their age and relative abundance imply that the FU Orionis phase occurs over a timescale of approixmately 10(exp 5) yr, and the quiescent phase between each outburst lasts approximately 10(exp 3) =10(exp 4) yr. These inferred properties are compatible with the scenario that FU Orionis outbursts are regulated by a thermal instability in the inner region of the disk.

  20. Microorganisms, Organic Carbon, and Their Relationship with Oxidant Activity in Hyper-Arid Mars-Like Soils: Implications for Soil Habitability

    NASA Technical Reports Server (NTRS)

    Valdivia-Silva, Julio E.; Karouia, Fathi; Navarro-Gonzalez, Rafael; McKay, Christopher

    2016-01-01

    Soil samples from the hyper-arid region in the Atacama 23 Desert in Southern Peru (La Joya Desert) were analyzed for total and labile organic carbon (TOC & LOC), phospholipid fatty acids analysis (PLFA), quantitative real time polymerase chain reaction (qRT-PCR), 4',6- diamidino-2-phenylindole (DAPI)-fluorescent microscopy, culturable microorganisms, and oxidant activity, in order to understand the relationship between the presence of organic matter and microorganisms in these types of soils. TOC content levels were similar to the labile pool of carbon suggesting the absence of recalcitrant carbon in these soils. The range of LOC was from 2 to 60 micro-g/g of soil. PLFA analysis indicated a maximum of 2.3 x 10(exp 5) cell equivalents/g. Culturing of soil extracts yielded 1.1 x 10(exp 2)-3.7 x 10(exp 3) CFU/g. qRT-PCR showed between 1.0 x 10(exp 2) and 8 x 10(exp 3) cells/g; and DAPI fluorescent staining indicated bacteria counts up to 5 x 104 cells/g. Arid and semiarid samples (controls) showed values between 10(exp 7) and 10(exp 11) cells/g with all of the methods used. Importantly, the concentration of microorganisms in hyper-arid soils did not show any correlation with the organic carbon content; however, there was a significant dependence on the oxidant activity present in these soil samples evaluated as the capacity to decompose sodium formate in 10 hours. We suggest that the analysis of oxidant activity could be a useful indicator of the microbial habitability in hyper-arid soils, obviating the need to measure water activity over time. This approach could be useful in astrobiological studies on other worlds.

  1. Photochemistry of Triton's Atmosphere and Ionosphere

    NASA Technical Reports Server (NTRS)

    Krasnopolsky, Vladimir A.; Cruikshank, Dale P.

    1995-01-01

    The photochemistry of 32 neutral and 21 ion species in Triton's atmosphere is considered. Parent species N2, CH4, and CO (with a mixing ratio of 3 x 10(exp -4) in our basic model) sublime from the ice with rates of 40, 208, and 0.3 g/sq cm/b.y., respectively. Chemistry below 50 km is driven mostly by photolysis of methane by the solar and interstellar medium Lyman-alpha photons, producing hydrocarbons C2H4, C2H6, and C2H2 which form haze particles with precipitation rates of 135, 28, and 1.3 g/sq cm/b.y., respectively. Some processes are discussed which increase the production of HCN (by an order of magnitude to a value of 29 g/sq cm/b.y.) and involve indirect photolysis of N2 by neutrals. Reanalysis of the measured methane profiles gives an eddy diffusion coefficient K = 4 x 10(exp 3) sq cm/s above the tropopause and a more accurate methane number density near the surface, (3.1 +/- 0.8) x 10(exp 11)/cc cm. Chemistry above 200 km is driven by the solar EUV radiation (lambda less than 1000 A)) and by precipitation of magnetospheric electrons with a total energy input of 10(exp 8) W (based on thermal balance calculations). The most abundant photochemical species are N, H2, H, O, and C. They escape with the total rates of 7.7 x 10(exp 24)/ s, 4.5 x 10(exp 25)/ s, 2.4 x 10(exp 25)/ s, 4.4 x 10(exp 22)/ s, and 1.1 x 10(exp 24)/ s, respectively. Atomic species are transported to a region of 50-200 km and drive the chemistry there. Iono- spheric chemistry explains the formation of an E region at 150-240 km with HCO(+) as a major ion, and of an F region above 240 km with a peak at 320 km and C(+) as a major ion. The ionosphere above 500 km consists of almost equal densities of C(+) and N(+) ions. The model profiles agree with the measured atomic nitrogen and electron density profiles. A number of other models with varying rate coefficients of some reactions, differing properties of the haze particles (chemically passive or active), etc., were developed. These models show

  2. 5 CFR 1632.5 - Exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD RULES REGARDING PUBLIC OBSERVATION OF MEETINGS § 1632.5 Exemptions. (a) Except in a case where the Board finds that the public interest requires...), provided that such statute: (i) Requires that the matters be withheld from the public in such a manner...

  3. Baltimore PM2.5 Supersite: highly time-resolved organic compounds--sampling duration and phase distribution--implications for health effects studies.

    PubMed

    Rogge, Wolfgang F; Ondov, John M; Bernardo-Bricker, Anna; Sevimoglu, Orhan

    2011-12-01

    As part of the Baltimore PM2.5 Supersite study, intensive three-hourly continuous PM2.5 sampling was conducted for nearly 4 weeks in summer of 2002 and as well in winter of 2002/2003. Close to 120 individual organic compounds have been quantified separately in filter and polyurethane foam (PUF) plug pairs for 17 days for each sampling period. Here, the focus is on (1) describing briefly the new sampling system, (2) discussing filter/PUF plugs breakthrough experiments for semi-volatile compounds, (3) providing insight into phase distribution of semi-volatile organic species, and (4) discussing the impact of air pollution sampling time on human exposure with information on maximum 3- and 24-h averaged ambient concentrations of potentially adverse health effects causing organic pollutants. The newly developed sampling system consisted of five electronically controlled parallel sampling channels that are operated in a sequential mode. Semi-volatile breakthrough experiments were conducted in three separate experiments over 3, 4, and 5 h each using one filter and three PUF plugs. Valuable insight was obtained about the transfer of semi-volatile organic compounds through the sequence of PUF plugs and a cut-off could be defined for complete sampling of semi-volatile compounds on only one filter/PUF plug pair, i.e., the setup finally used during the seasonal PM2.5 sampling campaign. Accordingly, n-nonadecane (C19) with a vapor pressure (vp) of 3.25 × 10(-4) Torr is collected with > 95% on the filter/PUF pair. Applied to phenanthrene, the most abundant the PAH sampled, phenanthrene (vp, 6.2 × 10(-5) Torr) was collected completely in wintertime and correlates very well with three-hourly PM2.5 ambient concentrations. Valuable data on the fractional partitioning for semi-volatile organics as a function of season is provided here and can be used to differentiate the human uptake of an organic pollutant of interest via gas- and particle-phase exposure. Health effects studies

  4. Rosat observations of FK comae berenices

    NASA Technical Reports Server (NTRS)

    Welty, Alan D.; Ramsey, Lawrence W.

    1994-01-01

    We obtained ROSAT PSPC observations of FK Com over a period of 24.4 h, or 0.42 rotation. During the observations the x-ray flux increased by a factor of at least 5 before declining toward its previous level. A single temperature Raymond-Smith model is adequate to model the low signal-to-noise ratio spectrum from each observation interval. Initially the spectrum was that of a 8.5 x 10(exp 6) K plasma, with L9sub x)=0.66 x 10(exp 31) erg s(exp -1). When the x-ray flux was greatest, the model plasma temperature rose to 2.5 x 10(exp 7) K, and L(sub x)=3.46 x 10(exp 31) ergs(exp -1). During the post-maximum decline in luminosity the plasma temperature was approximately 12 x 10(exp 6) K. We conclude that the increase of x-ray flux recorded by ROSAT was due to an x-ray flare with a 1.5 h decline time scale.

  5. Microwave Conductivity of Laser Ablated YBa2Cu3O7-delta Superconducting Films and Its Relation to Microstrip Transmission Line Performance

    NASA Technical Reports Server (NTRS)

    Bhasin, K. B.; Warner, J. D.; Chorey, C. M.; Ebihara, B. T.; Romanofsky, R. R.; Heinen, V. O.

    1990-01-01

    We report on the values of the microwave conductivity in the normal (sigma(subN)) and superconducting (sigma*=sigma(sub1)-j sigma(sub2)) states of two laser ablated YBa2CU3O7(sigma) thin films at 35 GHz, in the temperature range from 20 to 300 K. The films 0.7 and 0.4 micrometers) were deposited on LaA10(sub3) by laser ablation. The conductivity was obtained from the microwave power transmitted through the films and assuming a two-fluid model. Values of sigma(subN) approximately 2.3 X 10(exp5) S/m at room temperature for both films, and of sigma(sub1) approximately 6.3 X 10(exp5) and 4.6 X 10(exp5) S/m at temperatures around 80 K were obtained for the 0.7 and 0.4 micrometer films respectively. For sigma(sub2) values of 4.9 X 10(exp6) and 5.4 X 10(exp6) S/m were obtained for the 0.7 and 0.4 micrometer films at 80 K. The expected conductor losses and Q-factor of a superconducting ring resonator were calculated using these conductivity values. The theoretical values were then compared with the experimental results obtained for a resonator fabricated from one of these films.

  6. 5-HIAA Test

    MedlinePlus

    ... this page helpful? Also known as: HIAA; Serotonin Metabolite Formal name: 5-hydroxyindoleacetic Acid Related tests: Serotonin ; ... chromogranin A level . 5-HIAA is the primary metabolite of serotonin that is excreted in the urine. ...

  7. GEOS-5 Modeled Clouds

    NASA Video Gallery

    This visualization shows clouds from a simulation using the Goddard Earth Observing System Model, Verison 5 (GEOS-5). The global atmospheric simulation covers a period from Feb 3, 2010 through Feb ...

  8. 5-HIAA urine test

    MedlinePlus

    HIAA; 5-hydroxyindole acetic acid; Serotonin metabolite ... This test measures the level of 5-HIAA in the urine. It is often done to detect certain tumors in the digestive tract ( carcinoid tumors ) ...

  9. Electrical characterization of 6H crystalline silicon carbide. M.S. Thesis Final Report

    NASA Technical Reports Server (NTRS)

    Lempner, Stephen E.

    1994-01-01

    Crystalline silicon carbide (SiC) substrates and epilayers, undoped as well as n- and p-doped, have been electrically characterized by performing Hall effect and resistivity measurements (van der Pauw) over the temperature range of approximately 85 K to 650 K (200 K to 500 K for p-type sample). By fitting the measured temperature dependent carrier concentration data to the single activation energy theoretical model: (1) the activation energy for the nitrogen donor ranged from 0.078 eV to 0.101 eV for a doping concentration range of 10(exp 17) cm(exp -3) to 10(exp 18) cm(exp -3) and (2) the activation energy for the aluminum acceptor was 0.252 eV for a doping concentration of 4.6 x 10(exp 18) cm(exp -3). By fitting the measured temperature dependent carrier concentration data to the double activation energy level theoretical model for the nitrogen donor: (1) the activation energy for the hexagonal site was 0.056 eV and 0.093 eV corresponding to doping concentrations of 3.33 x 10 (exp 17) cm(exp -3) and 1.6 x 10(exp 18) cm(exp -3) and (2) the activation energy for the cubic site was 0.113 and 0.126 eV corresponding to doping concentrations of 4.2 x 10(exp 17) cm(exp -3) and 5.4 x 10(exp 18) cm(exp -3).

  10. Characterization of voids formed during liquid impregnation of nonwoven multifilament glass networks as related to composite processing

    NASA Technical Reports Server (NTRS)

    Mahale, Anant D.; Prudhomme, Robert K.; Rebenfeld, Ludwig

    1993-01-01

    A technique based on matching the refractive index of an invading liquid to that of a fiber mat was used to study entrapment of air ('voids') that occurs during forced in-plane radial flow into nonwoven multifilament glass networks. The usefulness of this technique is demonstrated in quantifying and mapping the air pockets. Experiments with a series of fluids with surface tensions varying from 28 x 10(exp -3) to 36 x 10(exp -3) N/m, viscosities from 45 x 10(exp -3) to 290 x 10(exp -3) Pa.s, and inlet flow rates from 0.15 x 10(exp -6) to 0.75 x 10(exp -6) m(exp 3)/s, showed that void content is a function of the capillary number characterizing the flow process. A critical value of capillary number, Ca = 2.5 x 10(exp -3), identifies a zone below which void content increases exponentially with decreasing capillary number. Above this critical value, negligible entrapment of voids is observed. Similar experiments carried out on surface treated nonwoven mats spanning a range of equilibrium contact angles from 20 deg to 78 deg showed that there is a critical contact angle above which negligible entrapment is observed. Below this value, there is no apparent effect of contact angle on the void fraction - capillary number relationship described earlier. Studies on the effect of filament wettability, and fluid velocity and viscosity on the size of the entrapment (voids) were also carried out. These indicate that larger sized entrapments which envelop more than one pore are favored by a low capillary number in comparison to smaller, pore level bubbles. Experiments were carried out on deformed mats - imposing high permeability spots at regular intervals on a background of low permeability. The effect of these spatial fluctuations in heterogeneity of the mat on entrapment is currently being studied.

  11. A burst from a thermonuclear runaway on an ONeMg white dwarf

    NASA Technical Reports Server (NTRS)

    Starrfield, S.; Politano, M.; Truran, J. W.; Sparks, W. M.

    1992-01-01

    Studies which examine the consequences of accretion, at rates of 10(exp -9) solar mass/yr and 10(exp -10) solar mass/yr, onto an ONeMg white dwarf with a mass of 1.35 solar masses are performed. In these studies, a Lagrangian, hydrodynamic, one-dimensional computer code was used. The code now includes a network with 89 nuclei up to Ca-40, elemental diffusion, new opacities, and new equation of state. The initial abundance distribution corresponded to a mixture that was enriched to either 25, 50, or 75 percent in products of carbon burning. The remaining material in each case is assumed to have a solar composition. The evolution of the thermonuclear runaway in the 1.35 solar mass white dwarf, with M = 10(exp -9) solar mass, produced peak temperatures in the shell source exceeding 300 million degrees. The sequence produced significant amounts of Na-22 from proton captures onto Ne-20 and significant amounts of Al-26 from proton captures on Mg-24. This sequence ejected 5.2 x 10(exp -6) solar mass moving with speeds from approximately 100 km/s to 2300 km/s. When the mass accretion rate was decreased to 10(exp -10) solar mass, the resulting thermonuclear runaway produced a shock that moved through the outer envelope of the white dwarf and raised the surface luminosity to L greater than 10(exp 7) solar luminosity and the effective temperature to values exceeding 10(exp 7) K. The interaction of the material expanding from off of the white dwarf with the accretion disk should produce a burst of gamma-rays.

  12. LAURA Users Manual: 5.5-64987

    NASA Technical Reports Server (NTRS)

    Mazaheri, Alireza; Gnoffo, Peter A.; Johnston, Christopher O.; Kleb, William L.

    2013-01-01

    This users manual provides in-depth information concerning installation and execution of LAURA, version 5. LAURA is a structured, multi-block, computational aerothermodynamic simulation code. Version 5 represents a major refactoring of the original Fortran 77 LAURA code toward a modular structure afforded by Fortran 95. The refactoring improved usability and maintain ability by eliminating the requirement for problem dependent recompilations, providing more intuitive distribution of functionality, and simplifying interfaces required for multi-physics coupling. As a result, LAURA now shares gas-physics modules, MPI modules, and other low-level modules with the Fun3D unstructured-grid code. In addition to internal refactoring, several new features and capabilities have been added, e.g., a GNU standard installation process, parallel load balancing, automatic trajectory point sequencing, free-energy minimization, and coupled ablation and flowfield radiation.

  13. 5.5 billion -- and growing.

    PubMed

    Robey, B

    1992-07-17

    On World Population Day in 1992 the total world population reached 5.5 billion, 100 million more than on July 11, 1991, and it is expected to pass the 6 billion figure by 2000. In developed countries the average number of children is 2/family, while in developing countries the norm is 4 children, a substantial drop from 6 children in the 1960s. The 2 billion level was reached in 1930, the world population doubled from 1 billion in 100 years. The billion mark in 1960 took only 30 years, the 4 billion figure was reached in 1975 in only 15 years, and to grow to 5 billion in 1987 took only 12 years. A 20-year delay to reach replacement level adds another 1 billion to the population size. If the 2-children-per family size had been reached in 1990, the total would still have increased to 8 billion by 2100. Provided the present trend of 3.4 children/couple continues, there will be 102 billion people in 2100. Some claim that the resources of the Earth are already overtaxed with ever-worsening environmental pollution. Family planning information and services have to me made available to those millions who want to avoid pregnancy and ensure a better future for fewer children.

  14. 5-Second Rule

    MedlinePlus

    ... A Week of Healthy Breakfasts Shyness The 5-Second Rule KidsHealth > For Teens > The 5-Second Rule Print A A A Almost everyone has ... to eat it. Some people apply the "5-second rule" — that random saying about how food won' ...

  15. The 5-Second Rule

    MedlinePlus

    ... What Happens in the Operating Room? The 5-Second Rule KidsHealth > For Kids > The 5-Second Rule Print A A A en español La ... it, he or she might have yelled, "5-second rule!" This so-called rule says food is ...

  16. Duplex Oxide Formation during Transient Oxidation of Cu-5%Ni(001) Investigated by In situ UHV-TEM and XPS

    SciTech Connect

    Yang, J.C.; Starr, D.; Kang, Y.; Luo, L.; Tong, X.; Zhou, G.

    2012-05-20

    The transient oxidation stage of a model metal alloy thin film was characterized with in situ ultra-high vacuum (UHV) transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and analytic high-resolution TEM. We observed the formations of nanosized NiO and Cu{sub 2}O islands when Cu-5a5%Ni(100) was exposed to oxygen partial pressure, pO{sub 2} = 1 x 10{sup -4} Torr and various temperatures in situ. At 350 C epitaxial Cu{sub 2}O islands formed initially and then NiO islands appeared on the surface of the Cu{sub 2}O island, whereas at 750 C NiO appeared first. XPS and TEM was used to reveal a sequential formation of NiO and then Cu{sub 2}O islands at 550 C. The temperature-dependant oxide selection may be due to an increase of the diffusivity of Ni in Cu with increasing temperature.

  17. Aerodynamic characteristics and pressure distributions for an executive-jet baseline airfoil section

    NASA Technical Reports Server (NTRS)

    Allison, Dennis O.; Mineck, Raymond E.

    1993-01-01

    A wind tunnel test of an executive-jet baseline airfoil model was conducted in the adaptive-wall test section of the NASA Langley 0.3-Meter Transonic Cryogenic Tunnel. The primary goal of the test was to measure airfoil aerodynamic characteristics over a wide range of flow conditions that encompass two design points. The two design Mach numbers were 0.654 and 0.735 with corresponding Reynolds numbers of 4.5 x 10(exp 6) and 8.9 x 10(exp 6) based on chord, respectively, and normal-force coefficients of 0.98 and 0.51, respectively. The tests were conducted over a Mach number range from 0.250 to 0.780 and a chord Reynolds number range from 3 x 10(exp 6) to 18 x 10(exp 6). The angle of attack was varied from -2 deg to a maximum below 10 deg with one exception in which the maximum was 14 deg for a Mach number of 0.250 at a chord Reynolds number of 4.5 x 10(exp 6). Boundary-layer transition was fixed at 5 percent of chord on both the upper and lower surfaces of the model for most of the test. The adaptive-wall test section had flexible top and bottom walls and rigid sidewalls. Wall interference was minimized by the movement of the adaptive walls, and the airfoil aerodynamic characteristics were corrected for any residual top and bottom wall interference.

  18. Synthesis of CORONA 5 (Ti-4.5Al-5Mo-1.5Cr)

    NASA Astrophysics Data System (ADS)

    Froes, F. H.; Highberger, W. T.

    1980-05-01

    The synthesis of CORONA 5 (Ti-4.5Al-5Mo-1.5Cr) is described from the viewpoints of alloy chemistry and microstructure. Lenticular alpha is shown to maximize fracture resistance parameters, while a globular alpha optimizes hightemperature flow characteristics. The processing and application of CORONA 5 as forging, plate, sheet and powder metallurgy products are presented. The weldability of the alloy is described and potential use of the alloy for engine applications discussed. The improved mechanical property behavior over the "workhorse" Ti-6Al-4V alloy combined with cost-effective production should result in use of CORONA 5 in many applications. Future developments for CORONA 5 are suggested both in terms of further mechanical property optimization and in light of the economics of producing the alloy.

  19. QCD for Postgraduates (5/5)

    ScienceCinema

    None

    2016-07-12

    Modern QCD - Lecture 5 We will introduce and discuss in some detail the two main classes of jets: cone type and sequential-recombination type. We will discuss their basic properties, as well as more advanced concepts such as jet substructure, jet filtering, ways of optimizing the jet radius, ways of defining the areas of jets, and of establishing the quality measure of the jet-algorithm in terms of discriminating power in specific searches. Finally we will discuss applications for Higgs searches involving boosted particles.

  20. Infrared Measurements of Atmospheric Gases Above Mauna Loa, Hawaii, in February 1987

    NASA Technical Reports Server (NTRS)

    Rinsland, C. P.; Goldman, A.; Murcray, F. J.; Murcray, F. H.; Blatherwick, R. D.; Murcray, D. G.

    1988-01-01

    Infrared solar absorption spectra recorded at 0.02/ cm resolution from the National Oceanic and Atmospheric Administration (NOAA) Geophysical Monitoring for Climate Change (GMCC) program station at Mauna Loa, Hawaii (latitude 19.5 deg N, longitude 155.6 deg W, elevation 3.40 km), in February 1997 have been analyzed to determine simultaneous total vertical column amounts for 13 atmospheric gases. Average tropospheric concentrations of CO2, N2O, CH4, and CHCIF2 and the daytime diurnal variations or the total columns of NO and NO2 have also been inferred. The retrieved total columns (in molecules /sq cm) of the nondiurnally varying gases are 1.6 +/- 0.2 x 10(exp 15) for HCl, 5.9 +/- 1.2 x 10(exp 15) for HNO3, 2.0 +/- 0.2 x 10(exp 21) for H2O16, 4.4 +/- 0.7 x 10(exp 18) for H2O18, 2.7 +/- 0.1 x 10(exp 17) for HDO, 2.3 +/- 0.2 x 10(exp 19) for CH4, 5.0 +/- 0.5 x 10(exp 21) for CO2, 6.7 +/- 0.8 x 10(exp 18) for O3, 4.3 +/- 0.4 x 10(exp 18) for N2O, 1.0 +/- 0.2 x 10(exp 16) for C2H6, and 9.7 +/- 2.5 x 10(exp 14) for CHClF2. We compare the total column measurements of HCl and HNO3 with previously reported ground-based, aircraft, and satellite measurements. The results for HCl are or particular interest because of the expected temporal increase in the concentration of this gas in the stratosphere. However, systematic differences among stratospheric HCl total column measurements from 1978 to 1980 and the absence of observations of free tropospheric HCl above Mauna Loa make it impossible to obtain a reliable estimate of the trend in the total burden of HCl. The measured HNO3 total column is consistent with aircraft measurements from approx. 12 km altitude. The O3 total column deduced from the IR spectra agrees with correlative Mauna Loa Umkehr measurements within the estimated error limits. The column-averaged D/H ratio of water vapor is (68 +/- 9) x- 10(exp -6), which is 0.44 +/- 0.06 times the reference value of 155.76 x 10(exp -6) for standard mean ocean water (SMOW). This

  1. Sensitive detection of nitric oxide using a 5.26 μm external cavity quantum cascade laser based QEPAS sensor

    NASA Astrophysics Data System (ADS)

    Tittel, Frank K.; Dong, Lei; Lewicki, Rafal; Lee, George; Peralta, Adjani; Spagnolo, Vincenzo

    2012-01-01

    The development and performance of a continuous wave (CW), thermoelectrically cooled (TEC) external cavity quantum cascade laser (EC-QCL) based sensor for quantitative measurements of nitric oxide (NO) concentrations in exhaled breath will be reported. Human breath contains ~ 400 different chemical species, usually at ultra low concentration levels, which can serve as biomarkers for the identification and monitoring of human diseases or wellness states. By monitoring exhaled NO concentration levels, a fast non-invasive diagnostic method for treatment of patients with asthma and chronic obstructive pulmonary disease (COPD) is feasible. The NO concentration measurements are performed with a 2f wavelength modulation based quartz enhanced photoacoustic spectroscopy (QEPAS) technique, which is very suitable for real time breath measurements, due to the fast gas exchange inside a compact QEPAS gas cell (<5 mm3 typical volume). In order to target the optimal interference free NO R (6.5) absorption doublet at 1900.08 cm-1(λ~5.263 μm) a Daylight Solutions Inc. widely tunable, mode-hop free 100 mW EC-QCL was used. The sensor reference channel includes a 10 cm long reference cell, filled with a 0.5% NO in N2 at 150 Torr, which is used for line-locking purpose. A minimum detection limit (1σ) for the EC-QCL based line locked NO sensor is ~5 ppbv with a 1 sec update time by a custom built control QCL compatible electronics unit.

  2. Chemical Kinetic Studies Using Ultraviolet Cavity Ring-Down=20 Spectroscopic Detection: Self-Reaction of Ethyl and Ethylperoxy Radicals=20 and the Reaction, O2 + C_2H_5arrow C_2H_5O_2

    NASA Astrophysics Data System (ADS)

    Atkinson, Dean B.; Hudgens, Jeffrey W.

    1997-04-01

    A laser-photolysis reactor that uses cavity ring-down spectroscopic (CRDS) detection was characterized and used to measure the rate coefficients of three benchmark reactions of known importance to ethane oxidation. At 295 K and approximately 700 Pa (5.5 torr) total pressure we obtained the self-reaction rate coefficients of k =3D 1.99(±0.44)×10-11=A0cm^3s-1 for C_2H5 + C_2H5 and k =3D 7.26(±2.4)×10-14=A0cm^3s-1 for C_2H_5O2 + C_2H_5O_2. We obtained k =3D 2.7(±0.3)×10-12=A0cm^3s-1 for the pseudo-first order association reaction, O2 + C_2H5 + Ar. We also measured the absorption cross-sections of the ethyl radical, σ _220 =3D 252(±42)×10-20 cm^2 and σ _222 =3D 206(±42)×10-20 cm^2. Stated uncertainties are ±2σ. The new rate coefficients agree with those obtained previously by other methods. The agreement confirms that ultraviolet CRDS detection is a viable tool for experimental determinations of gas-phase radical-radical and radical-molecule reaction rate coefficients.

  3. FIFI: The MPE Garching/UC Berkeley Far-Infrared Imaging Fabry-Perot Interferometer

    NASA Technical Reports Server (NTRS)

    Geis, Norbert; Genzel, Reinhard; Haggerty, M.; Herrmann, F.; Jackson, J.; Madden, Suzanne C.; Nikola, T.; Poglitsch, Albrecht; Rumitz, M.; Stacey, G. J.

    1995-01-01

    We describe the performance characteristics of the MPE Garching/UC Berkeley Far-Infrared Imaging Fabry-Perot Interferometer (FIFI) for the Kuiper Airborne Observatory (KAO). The spectrometer features two or three cryogenic tunable Fabry-Perot filters in series giving spectral resolution R of up to 10(exp 5) in the range of 40 microns less than lambda less than 200 microns, and an imaging 5x5 array of photoconductive detectors with variable focal plane plate scale. The instrument works at background limited sensitivity of up to 2 x 10(exp -19) W cm(exp -2) Hz(exp -1/2) per pixel per resolution element at R = 10(exp 5) on the KAO.

  4. Space Environmental Effects on Thermal Control Coatings

    NASA Technical Reports Server (NTRS)

    OBrien, Susan K.; Workman, Gary L.

    1997-01-01

    The study of long term near ultra-violet (NUV) effects in a vacuum atmosphere, is a crucial element for space applications. NUV radiation causes significant changes in the reflectance of many coatings and types of materials. An ultra high vacuum NUV system was assembled in order to investigate various coatings and materials in this hostile environment. The vacuum is an ion pump that maintains a minimum vacuum in the mid 10(exp -9) range. The system has a base pressure of 10(exp -9) torr and this base pressure is maintained with the ion pump. The NUV exposure was maintained at 2-3 suns which allows accelerated NUV exposure without overheating the samples. The goal of this test was to maintain an intensity of 3.4 x 10(exp -2) Watts/cm(exp 2) which equals 2.9 NUV suns. An NUV sun is defined as 1.16 Watts/cm(exp 2) integrated over wavelength of 200-400 nanometers.

  5. Installing scientific instruments into a cold LHe dewar - The Gravity Probe B approach

    NASA Technical Reports Server (NTRS)

    Parmley, Richard T.; Kusunic, Keith; Reynolds, Gary; Stephenson, Sam; Alexander, Keith

    1990-01-01

    Gravity Probe B is an orbital test of Einstein's general theory of relativity using gyroscopes. The precession of the gyroscopes will measure both the geodetic effect (6.6 arcsec/yr) through the curved space-time surrounding the earth and the motional effect (0.042 arcsec/yr) due to the rotating earth dragging space-time around with it. To achieve the extraordinary accuracies needed to measure these small precessions, it is necessary to have the gyroscopes operating in the following environments: a vacuum of less than 10 exp -10 torr; an acceleration level of less than 10 exp -10 g's; a magnetic field of less than 10 exp -7 gauss; and a temperature near 2 K. This paper discusses designs that allow scientific instruments to be installed into a dewar at 4.2 K. Methods for structurally supporting the instruments, transferring heat across joints at low temperature in vacuum, and excluding air during the insertion process are discussed. The structural support method is designed for Shuttle launch loads.

  6. Radioimmunoassay for 5-methyltetrahydrohomofolate

    SciTech Connect

    Fong, K.L.; Ho, D.H.; Benjamin, R.S.; Yang, F.; Sickler, J.; Brown, N.S.; Bodey, G.P.

    1981-08-01

    A radioimmunoassay for 5-methyltetrahydrohomofolate has been developed by using antibody induced in rabbits by 5-methyltetrahydrohomofolate-bovine serum albumin conjugates. The labeled drug was prepared by condensing it with (/sub 3/H)histamine or (/sub 125/I)histamine. The assay employing either isotope was simple and reproducible and had identical sensitivities. The specificity of the antibody was characterized by comparing the effectiveness of various related compounds in displacing labeled 5-methyltetrahydrohomofolate from the binding site of the antisera. At concentrations up to 1000 microgram/ml, homofolate acid, tetrahydrohomofolic acid, folic acid and methotrexate showed no competition for the binding. 5-methyltetrahydrofolic acid and 5-formyltetrahydrofolic acid cross-reacted with the antisera; the concentrations producing 50% binding inhibition were 2.8 and 24 microgram, respectively, as compared to 0.01 microgram for 5-methyltetrahydrohomofolate. The assay can be used for measuring the drug in plasma and tissues. This study supports its usability for clinical pharmacologic studies.

  7. Adenosine(5') oligophospho-(5') guanosines and guanosine(5') oligophospho-(5') guanosines in human platelets.

    PubMed Central

    Schlüter, H; Grobeta, I; Bachmann, J; Kaufmann, R; van der Giet, M; Tepel, M; Nofer, J R; Assmann, G; Karas, M; Jankowski, J; Zidek, W

    1998-01-01

    We isolated and identified nucleoside(5') oligophospho-(5') nucleosides containing adenosine and guanosine (ApnG; n = 3-6) as well as diguanosine polyphosphates (GpnG; n = 3-6) in human platelets. For identification, UV spectrometry, matrix-assisted laser desorption/ionization, postsource decay matrix-assisted laser desorption/ionization mass spectrometry, and enzymatic cleavage experiments were used. The adenosine(5') oligophospho-(5') guanosines act as vasoconstrictors and growth factors. The diguanosine polyphosphates are potent modulators of growth in vascular smooth muscle cells, but do not affect vascular tone. PMID:9449703

  8. Neuropharmacology of 5-hydroxytryptamine

    PubMed Central

    Richard Green, A

    2006-01-01

    This review outlines the history of our knowledge of the neuropharmacology of 5-hydroxytryptamine (5-HT; serotonin), focusing primarily on the work of U.K. scientists. The existence of a vasoconstrictive substance in the blood has been known for over 135 years. The substance was named serotonin and finally identified as 5-HT in 1949. The presence of 5-HT in the brain was reported by Gaddum in 1954 and it was Gaddum who also demonstrated that the action of 5-HT (in the gut) was antagonised by the potent hallucinogen lysergic acid diethylamide. This provoked the notion that 5-HT played a pivotal role in the control of mood and subsequent investigations have generally confirmed this hypothesis. Over the last 50 years a good understanding has been gained of the mechanisms involved in control of the storage, synthesis and degradation of 5-HT in the brain. Knowledge has also been gained on control of the functional activity of this monoamine, often by the use of behavioural models. A considerable literature also now exists on the mechanisms by which many of the drugs used to treat psychiatric illness alter the functional activity of 5-HT, particularly the drugs used to treat depression. Over the last 20 years the number of identified 5-HT receptor subtypes has increased from 2 to 14, or possibly more. A major challenge now is to utilise this knowledge to develop receptor-specific drugs and use the information gained to better treat central nervous system disorders. PMID:16402098

  9. Adsorption of CO(2), CH(4), N(2)O, and N(2) on MOF-5, MOF-177, and zeolite 5A.

    PubMed

    Saha, Dipendu; Bao, Zongbi; Jia, Feng; Deng, Shuguang

    2010-03-01

    Adsorption equilibrium and kinetics of CO(2), CH(4), N(2)O, and N(2) on two newly discovered adsorbents, metal-organic frameworks MOF-5 and MOF-177 and one traditional adsorbent, zeolite 5A were determined to assess their efficacy for CO(2), CH(4), and N(2)O removal from air and separation of CO(2) from CH(4) in pressure swing adsorption processes. Adsorption equilibrium and kinetics data for CO(2), CH(4), N(2)O, and N(2) on all three adsorbents were measured volumetrically at 298K and gas pressures up to 800 Torr. Adsorption equilibrium capacities of CO(2) and CH(4) on all three adsorbents were determined gravimetrically at 298 K and elevated pressures (14 bar for CO(2) and 100 bar for CH(4)). The Henry's law and Langmuir adsorption equilibrium models were applied to correlate the adsorption isotherms, and a classical micropore diffusion model was used to analyze the adsorption kinetic data. The adsorption equilibrium selectivity was calculated from the ratio of Henry's constants, and the adsorbent selection parameter for pressure swing adsorption processes were determined by combining the equilibrium selectivity and working capacity ratio. Based on the selectivity and adsorbent selection parameter results, zeolite 5A is a better adsorbent for removing CO(2) and N(2)O from air and separation of CO(2) from CH(4), whereas MOF-177 is the adsorbent of choice for removing CH(4) from air. However, both MOF adsorbents have larger adsorption capacities for CO(2) and CH(4) than zeolite 5A at elevated pressures, suggesting MOF-5 and MOF-177 are better adsorbents for CO(2) and CH(4) storage. The CH(4) adsorption capacity of 22 wt.% on MOF-177 at 298K and 100 bar is probably the largest adsorption uptake of CH(4) on any dry adsorbents. The average diffusivity of CO(2), CH(4) and N(2)O in MOF-5 and MOF-177 is in the order of 10(-9) m(2)/s, as compared to 10(-11) m(2)/s for CO(2), CH(4) and N(2)O in zeolite 5A. The effects of gas pressure on diffusivity for different adsorabte

  10. Heat Transfer Modeling and Validation for Optically Thick Alumina Fibrous Insulation

    NASA Technical Reports Server (NTRS)

    Daryabeigi, Kamran

    2009-01-01

    Combined radiation/conduction heat transfer through unbonded alumina fibrous insulation was modeled using the diffusion approximation for modeling the radiation component of heat transfer in the optically thick insulation. The validity of the heat transfer model was investigated by comparison to previously reported experimental effective thermal conductivity data over the insulation density range of 24 to 96 kg/cu m, with a pressure range of 0.001 to 750 torr (0.1 to 101.3 x 10(exp 3) Pa), and test sample hot side temperature range of 530 to 1360 K. The model was further validated by comparison to thermal conductivity measurements using the transient step heating technique on an insulation sample at a density of 144 kg/cu m over a pressure range of 0.001 to 760 torr, and temperature range of 290 to 1090 K.

  11. Spark-hdf5

    SciTech Connect

    Asplund, Joshua; Jiang, Ming; Gallagher, Brian; Miller, Mark; Harrison, Cyrus

    2016-07-05

    The spark-hdf5 package is an extension to the Apache Spark program to allow native access to HDF5 files. It allows users to query the structured files using SQL-like syntax, and can parallelize large queries across several workers.

  12. 14 CFR 5 - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Section 5 Section Section 5 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS UNIFORM SYSTEM OF ACCOUNTS AND REPORTS FOR LARGE CERTIFICATED AIR CARRIERS Balance Sheet Classifications Section...

  13. Geostationary Meteorological Satellite-5 (GMS-5)

    NASA Technical Reports Server (NTRS)

    Horii, M.

    1991-01-01

    The Geostationary Meteorological Satellite (GMS-5), which is being developed by the National Space Development Agency of Japan (NASDA), is the fifth geostationary, spin stabilized, weather satellite. Its purposes are to observe cataclysmic events such as hurricanes, typhoons, and regional weather phenomena; to relay meteorological data from surface collection points to the Data Processing Center in Japan; and to transmit processing imaging data for facsimile reproduction. The satellite will be launched from the Tanegashima Space Center (TaSC) in Japan by a type H-II launch vehicle. The Deep Space Network (DSN) will support the transfer and drift orbit mission phases. The coverage will consist of the 26-m antennas as prime and the 34-m antenna at Madrid as backup support for launch through drift orbit. Maximum support will consist of two 8-hour tracks per station for a seven day period, plus 23 days of contingency support from all complexes. Information is given in tabular form for DSN support, frequency assignments, telemetry, command and tracking station responsibility.

  14. Photochemistry of Triton's Atmosphere and Ionosphere

    NASA Technical Reports Server (NTRS)

    Krasnopolsky, Vladimir A.; Cruikshank, Dale P.

    1995-01-01

    The photochemistry of 32 neutral and 21 ion species in Triton's atmosphere is considered. Parent species N2, CH4, and CO (with a mixing ratio of 3 x 10(exp -4) in our basic model) sublime from the ice with rates of 40, 208, and 0.3 g/sq cm/b.y., respectively. Chemistry below 50 km is driven mostly by photolysis of methane by the solar and interstellar medium Lyman-alpha photons, producing hydrocarbons C2H4, C2H6, and C2H2 which form haze particles with precipitation rates of 135, 28, and 1.3 g/sq cm/b.y., respectively. Some processes are discussed which increase the production of HCN (by an order of magnitude to a value of 29 g/sq cm/b.y.) and involve indirect photolysis of N2 by neutrals. Reanalysis of the measured methane profiles gives an eddy diffusion coefficient K = 4 x 10(exp 3)sq cm/s above the tropopause and a more accurate methane number density near the surface, (3.1 +/- 0.8)x IO(exp 11)/cu cm. Chemistry above 200 km is driven by the solar EUV radiation (lambda less than 1000 A) and by precipitation of magnetospheric electrons with a total energy input of 10(exp 8) W (based on thermal balance calculations). The most abundant photochemical species are N, H2, H, 0, and C. They escape with the total rates of 7.7 x 10(exp 24)/ s, 4.5 x 10(exp 25)/s, 2.4 x 10(exp 25)/s, 4.4 x 10(exp 22)/s, and 1.1 x 10(exp 24), respectively. Atomic species are transported to a region of 50-200 km and drive the chemistry there. Ionospheric chemistry explains the formation of an E region at 150-240 km with HCO(+) as a major ion, and of an F region above 240 km with a peak at 320 km and C(+) as a major ion. The ionosphere above 500 km consists of almost equal densities of C(+) and N(+) ions. The model profiles agree with the measured atomic nitrogen and electron density profiles. A number of other models with varying rate coefficients of some reactions, differing properties of the haze particles (chemically passive or active), etc., were developed. These models show that there

  15. Chromosome 5 workshop.

    PubMed

    Crowe, R R; Vieland, V

    1998-01-01

    In schizophrenia, evidence consistent with linkage in the 5q23.3-q31.1 region emerged from three independent samples. In addition, a moderately retarded woman with schizophrenia with an interstitial deletion overlapping this region was reported at the workshop. A second region of interest for schizophrenia is the 5p14.1-p13.1 region, where lod scores as high as 4.37 were found in one pedigree. Chromosome 5p15 gave a non-parametric linkage (NPL) score of 2.18 (p < 0.02) in one study. Several genome scans have not found evidence of excess allele sharing in these regions, although in most cases the genome scans did not include the markers that had resulted in provisional evidence of linkage. A large pedigree of bipolar illness has shown provisional evidence of linkage at, or near, the dopamine transporter locus at 5p15.3; the maximum lod score obtained was 2.72 at D5S417. In other regions, a genome scan of bipolar disorder gave NPL scores of 2.98 at D5S812 and 3.76 at D5S423. The third disorder of interest is attention deficit hyperactivity disorder (ADHD) because two studies have reported an association with the 480 bp allele at the dopamine transporter locus. A poster presented at the Congress reported a failure to replicate the association in a sample with considerable power to detect the effect size previously reported.

  16. The E5 Proteins

    PubMed Central

    DiMaio, Daniel; Petti, Lisa

    2013-01-01

    The E5 proteins are short transmembrane proteins encoded by many animal and human papillomaviruses. These proteins display transforming activity in cultured cells and animals, and they presumably also play a role in the productive virus life cycle. The E5 proteins are thought to act by modulating the activity of cellular proteins. Here, we describe the biological activities of the best-studied E5 proteins and discuss the evidence implicating specific protein targets and pathways in mediating these activities. The primary target of the 44-amino acid BPV1 E5 is the PDGF β receptor, whereas the EGF receptor appears to be an important target of the 83-amino acid HPV16 E5 protein. Both E5 proteins also bind to the vacuolar ATPase and affect MHC class I expression and cell-cell communication. Continued studies of the E5 proteins will elucidate important aspects of transmembrane protein-protein interactions, cellular signal transduction, cell biology, virus replication, and tumorigenesis. PMID:23731971

  17. 5-fluorouracil induced pericarditis.

    PubMed

    Killu, Ammar; Madhavan, Malini; Prasad, Kavita; Prasad, Abhiram

    2011-04-15

    Cardiac toxicity is an infrequent, but potentially serious side effect of 5-fluorouracil (5-FU). The reported incidence of 5-FU-induced cardiotoxicity is approximately 3%, although estimates vary from 1.2% to 18%. Cardiac death occurs in less than 1%. The prompt recognition of cardiac toxicity demands a thorough understanding of the myriad of potential cardiac manifestations and a high index of suspicion. The most common presentation is angina pectoris while other manifestations, namely myocardial infarction, left ventricular dysfunction, arrhythmias and sudden death have been recognised. The authors report an unusual case of myopericarditis masquerading as myocardial infarction.

  18. X-ray-emitting gas surrounding the spiral galaxy NGC 891

    NASA Technical Reports Server (NTRS)

    Bregman, Joel N.; Pidis, Rachel A.

    1994-01-01

    We observed the edge-on spiral galaxy NGC 891 with the Position Sensitive Proportional Counter (PSPC) on Roentgen Satellite (ROSAT) to search for how extraplanar gas expected in the galactic fountain model. Diffuse X-ray emission surrounds the disk with a Half Width at Half Maximum (HWHM) for the surface brightness perpendicular to the disk of 50 sec (2.4 kpc) and a radial extent of approximately 6.5 kpc, both of which are similar in extent to the extended H(alpha) and radio halo component; the implied density scale height for the hot gas is 7 kpc. The spectrum is best fitted with a hard stellar component and a soft diffuse gas component of temperature 3.6 x 10(exp 6) K. The density of this gas is 2 x 10(exp -3)/cu cm, the luminosity is 4.4 x 10(exp 39) ergs/s, the mass is 1 x 10(exp 8) solar mass, and the pressure (P/k) is 1.4 10(exp 4) K/cu cm. These data are consistent with this gas participating in a galactic fountain, where the material approaches hydrostatic equilibrium before cooling at a rate of 0.12 solar mass/yr. The cooled material may be responsible for some of the H(alpha) emission.

  19. Volatility and Wear Characteristics of a Variety of Liquid Lubricants for Space Applications

    NASA Technical Reports Server (NTRS)

    Nguyen, Quynhgiao N.; Jones, William R., Jr.

    2001-01-01

    The vapor pressures and near characteristics are critical properties for liquid lubricants to assure long-term reliability and performance in space applications. Vapor pressures, obtained using a Knudsen cell technique, and near properties, obtained using a vacuum four-ball apparatus, were measured for a series of unformulated liquid lubricants. These include: two multiple alkylated cyclopentanes (MACs) (X-1000 and X-2000), two linear perfluoropolyalkylethers (PFPAEs) (Z-25 and 815Z), and four silahydrocarbons (a tri-, a tetra-, and two pentas). Vapor pressures were measured at three elevated temperatures (423, 448, and 498 K) and extrapolated to room temperature 298 K. The lowest 298 K vapor pressure of 5.7 x 10(exp -14) Pa, was obtained with the PFPAE fluid (815Z) and the highest value with the low molecular weight MAC (X-1000) at 3.6 x 10(exp -7) Pa. In addition, vacuum near rates were determined for some of the lubricants. The lowest wear rates (approximately 3 x 10(exp -11) cubic mm/mm) were observed for three of the silahydrocarbons while the highest wear rate (approximately 2 x 10(exp-9) cubic mm/mm) were observed with the two PFPAE fluids (Z-25 and 815Z). The MAC (X-2000) yielded a wear rate of about 10(exp -10) cubic mm/mm. The results indicated that the silahydrocarbon class of liquid lubricants offers the better potential for space applications.

  20. Volatility and Wear Characteristics of a Variety of Liquid Lubricants for Space Applications

    NASA Technical Reports Server (NTRS)

    Nguyen, QuynhGiao N.; Jones, William R., Jr.

    2001-01-01

    The vapor pressures and wear characteristics are critical properties for liquid lubricants to assure long-term reliability and performance in space applications. Vapor pressures, obtained using a Knudsen cell technique, and wear properties, obtained using a vacuum four-ball apparatus, were measured for a series of unformulated liquid lubricants. These included two multiply alkylated cyclopentanes (MACs) (X-1000 and X2000), two linear perfluoropolyalkylethers (PFPAEs) (Z-25 and 815Z), and four silahydrocarbons (a tri, a tetra, and two pentas). Vapor pressures were measured at three elevated temperatures (423, 448, and 498 K) and extrapolated to room temperature 298 K. The lowest 298 K vapor pressure of 5.7 x 10(exp -14) Pa was obtained with the PFPAE fluid (815Z) and the highest value with the low molecular weight MAC (X-1000) at 3.6 x 10(exp -7) Pa. In addition, vacuum wear rates were determined for some of the lubricants. The lowest wear rates (approximately 3 x 10(exp -11) cubic mm/mm) were observed for three of the silahydrocarbons while the highest wear rates (approximately 2 x 10(exp -9) cubic mm/mm) were observed with the two PFPAE fluids (Z-25 and 815Z). The MAC (X-2000) yielded a wear rate of about 10(exp -10) cubic mm/mm. The results indicated that the silahydrocarbon class of liquid lubricants offers the better potential for space applications.

  1. X-ray Characterization of Detached-Grown Germanium Crystals

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Schweizer, M.; Raghothamachar, B.; Dudley, M.; Szoke, J.; Cobb, S. D.; Szofran, F. R.

    2005-01-01

    Germanium (111)-oriented crystals have been grown by the vertical Bridgman technique, in both detached and attached configurations. Microstructural characterization of these crystals has been performed using synchrotron white beam x-ray topography (SWBXT) and double axis x-ray diffraction. Dislocation densities were measured from x-ray topographs obtained using the reflection geometry. For detached-grown crystals, the dislocation density is 4-6 x 10(exp 4) per square centimeter in the seed region, and decreases in the direction of growth to less than 10(exp 3) per square centimeter, and in some crystals reaches less than 10(exp 2) per square centimeter. For crystals grown in the attached configuration, dislocation densities were on the order of 10(exp 4) per square centimeter in the middle of the crystals, increasing to greater than 10(exp 5) per square centimeter near the edge. The measured dislocation densities are in excellent agreement with etch pit density results. The rocking curve linewidths were relatively insensitive to the dislocation densities. However, broadening and splitting of the rocking curves were observed in the vicinity of subgrain boundaries identified by x-ray topography in some of the attached-grown crystals.

  2. Absorption of water and lubricating oils into porous nylon

    NASA Technical Reports Server (NTRS)

    Bertrand, P. A.

    1995-01-01

    Oil and water absorption from air into sintered porous nylon can be described by infiltration into the pores of the material. This process can be modeled by a diffusion-like mechanism. For water absorption, we find a formal diffusion coefficient of 1.5 x 10(exp -4)sq cm/min when the nylon is initially dry. The diffusion coefficient is 4 x 10(exp -6)sq cm/min when the nylon is oil-impregnated prior to air exposure. In a 52% RH atmosphere, dry nylon absorbs 3% w/w water, and oil-impregnated nylon absorbs 0.6% w/w water. For oil absorption there are three steps: (1) surface absorption and infiltration into (2) larger and (3) smaller pores. Surface absorption is too fast to be measured in these experiments. The diffusion coefficient for the second step is 6 x 10(exp -4)sq cm/min for SRG-60 oil into dry nylon and 4 x 10(exp -4)sq cm/min for air-equilibrated nylon. The diffusion coefficient for the third step is about 1 x 10(exp -6)sq cm/min for both cases. The total amount of oil absorbed is 31% w/w. The interaction between water and nylon is not as strong as that between water and cotton-phenolic: oil can replace water, and only a small amount of water can enter previously oil-impregnated nylon.

  3. The Observed Galactic Annihilation Line: Possible Signature of Accreting Small Mass Black Holes in the Galactic Center

    NASA Technical Reports Server (NTRS)

    Titarchuk, Lev; Chardonnet, Pascal

    2006-01-01

    Various balloon and satellite observatories have revealed what appears to be an extended source of 0.511 MeV annihilation radiation with flux of approx. 10(exp -3) photons/sq cm/s centered on the Galactic Center. Positrons from radioactive products of stellar explosions can account for a significant fraction of the emission. We discuss an additional source for this emission: namely e(+)e(-) pairs produced when X-rays generated from the approx. 2.6 x 10(exp 6) solar mass Galactic Center Black Hole interact with approx. 10 MeV temperature blackbody emission from 10(exp 17) g black holes within 10(exp 14-l5) cm of the center. The number of such Small Mass Black Holes (SMMBHs) can account for the production of the 10(exp 42) e(+)/s that produces the observed annihilation in the inner Galaxy when transport effects are taken into account. We consider the possibility for confirming the presence of these SMMBHs in the Galactic Center region with future generations of gamma-ray instruments if a blackbody like emission of approx. 10 MeV temperature would be detected by them. Small Mass Black Hole can be a potential candidate for dark (invisible) matter hal

  4. The 5-Second Rule

    MedlinePlus

    ... to know about the 5-second rule: A clean-looking floor isn't necessarily clean. A floor that looks dirty is usually worse, but even dry floors that look clean can contain bacteria. Why? Some germs can survive ...

  5. Kinetics and Thermochemistry of the Br((sup 2)P3/2) + NO2 Association Reaction

    NASA Technical Reports Server (NTRS)

    Kreutter, K. D.; Nicovich, J. M.; Wine, P. H.

    1997-01-01

    A laser flash photolysis-resonance fluorescence technique has been employed to study the kinetics of the Br((sup 2)P3/2) + NO2 association reaction as a function of temperature (259-432 K) pressure (12.5 - 700 Torr), and buffer gas identity (He, Ar, H2, N2, CO2, CF4, SF6). The reaction is found to be in the falloff regime between third and second order over the entire range of conditions investigated. At temperatures below 350 K, the association reaction is found to be irreversible on the time scale of the experiment (approximately 30 ms). At higher temperatures reversible addition is observed, allowing equilibrium constants for BrNO2 formation and dissociation to be determined. Second- and third-law analyses of the equilibrium data are in only fair agreement and lead to the following thermochemical parameters for the association reaction: Delta-H(298) = 19.6 +/- 1.7 kcal/mol, Delta-H(0) = -18.6 +/- 2.0 kcal/mol, Delta-S(298) = 29.3 +/- 4.2 cal/mol/K, Delta-H(sub f)(sub 298)(BrNO2) = 17.0 +/-1.8 kcal/mol(uncertainties are 2 sigma estimates of absolute accuracy). The value for Delta-H(0) determined in this study has been employed to calculate k(sub 0)(sup SC), the low-pressure third-order rate coefficient in the strong collision limit, by using the method of Troe; calculated values of k(sub 0)(sup SC) are inconsistent with experimental results unless Delta-H(0) is assigned a value near the lower limit derived from analysis of the high-temperature approach to equilibrium data, i.e. delta-H(0) approximately equals -16.6 kcal/mol. A potential source of systematic error in the calculation of both k(sub 0)(sup SC) and the absolute entropy of BrNO2 results from the complete lack of knowledge of the energies and degeneracies of the electronic states of BrNO3. The procedure developed by Troe and co-workers has been employed to extrapolate experimental falloff curves to the low- and high-pressure limits. Derived values for k(sub 0)(M,298K) in units of 10(exp -31) cm(exp 6

  6. The Deep Space Network stability analyzer

    NASA Technical Reports Server (NTRS)

    Breidenthal, Julian C.; Greenhall, Charles A.; Hamell, Robert L.; Kuhnle, Paul F.

    1995-01-01

    A stability analyzer for testing NASA Deep Space Network installations during flight radio science experiments is described. The stability analyzer provides realtime measurements of signal properties of general experimental interest: power, phase, and amplitude spectra; Allan deviation; and time series of amplitude, phase shift, and differential phase shift. Input ports are provided for up to four 100 MHz frequency standards and eight baseband analog (greater than 100 kHz bandwidth) signals. Test results indicate the following upper bounds to noise floors when operating on 100 MHz signals: -145 dBc/Hz for phase noise spectrum further than 200 Hz from carrier, 2.5 x 10(exp -15) (tau =1 second) and 1.5 x 10(exp -17) (tau =1000 seconds) for Allan deviation, and 1 x 10(exp -4) degrees for 1-second averages of phase deviation. Four copies of the stability analyzer have been produced, plus one transportable unit for use at non-NASA observatories.

  7. Electron-Ion Recombination Rate Coefficient Measurements in a Flowing Afterglow Plasma

    NASA Technical Reports Server (NTRS)

    Gougousi, Theodosia; Golde, Michael F.; Johnsen, Rainer

    1996-01-01

    The flowing-afterglow technique in conjunction with computer modeling of the flowing plasma has been used to determine accurate dissociative-recombination rate coefficients alpha for the ions O2(+), HCO(+), CH5(+), C2H5(+), H3O(+), CO2(+), HCO2(+), HN2O(+), and N2O(+) at 295 K. We find that the simple form of data analysis that was employed in earlier experiments was adequate and we largely confirm earlier results. In the case of HCO(+) ions, published coefficients range from 1.1 X 10(exp -7) to 2.8 x 10(exp -7) cu cm/S, while our measurements give a value of 1.9 x 10(exp -7) cu cm/S.

  8. X-ray spectra from convective photospheres of neutron stars

    NASA Technical Reports Server (NTRS)

    Zavlin, V. E.; Pavlov, G. G.; Shibanov, Yu. A.; Rogers, F. J.; Iglesias, C. A.

    1996-01-01

    The preliminary results from the simulation of convective photospheres of neutron stars are presented. It is shown that in photospheres composed of light elements, convection arises at relatively low effective temperatures of between 3 x 10(exp 4) and 5 x 10(exp 4) K, whereas, in the case of iron composition, it arises at temperatures of less than or equal to 3 x 10(exp 5) K. Convection changes the depth dependence of the photosphere temperature and the shapes of the emergent spectra. It is concluded that depth should be taken into account for the correct interpretation of extreme ultraviolet/soft X-ray observations of the thermal radiation from neutron stars.

  9. A Numerical Method for Solving the Equations of Compressible Viscous Flow

    NASA Technical Reports Server (NTRS)

    MacCormack, R. W.

    1982-01-01

    Although much progress has already been made In solving problems in aerodynamic design, many new developments are still needed before the equations for unsteady compressible viscous flow can be solved routinely. This paper describes one such development. A new method for solving these equations has been devised that 1) is second-order accurate in space and time, 2) is unconditionally stable, 3) preserves conservation form, 4) requires no block or scalar tridiagonal inversions, 5) is simple and straightforward to program (estimated 10% modification for the update of many existing programs), 6) is more efficient than present methods, and 7) should easily adapt to current and future computer architectures. Computational results for laminar and turbulent flows at Reynolds numbers from 3 x 10(exp 5) to 3 x 10(exp 7) and at CFL numbers as high as 10(exp 3) are compared with theory and experiment.

  10. The GRADIO spaceborne gravity gradiometer: Development and accommodation

    NASA Astrophysics Data System (ADS)

    Bernard, A.

    1989-06-01

    The European ARISTOTELES mission aims at the determination of the Earth's gravity field at short wavelength with a global coverage. Gravity gradient measurements will be achieved during six months by the GRADIO instrument onboard a dedicated satellite in a near dawn-dusk sun-synchronous orbit at an altitude of 200 km. The objective is an accuracy of better than 5 mgals for gravity anomalies, at ground level for blocks of 1 x 1 deg. According to present knowledge of the potential, the recovery of higher spherical harmonics (degree and order greater than 30) is of main importance. This leads to focus on the variations of the measured components T(sub ij) of the gravity gradient tensor, at frequencies greater than 5 x 10(exp -3) Hz. The resolution, required for the gradiometer is 10(exp -2) Eotvos (i.e., 10(exp -11)/s squared) with an averaging time of 4 s.

  11. Survey of electronics capability for SP-100 space reactor power system applications

    NASA Technical Reports Server (NTRS)

    Manvi, Ram; Fujita, Tosh

    1991-01-01

    Because of reports indicating improvements in the radiation tolerance of some electronic parts, a survey was recently performed by SP-100 project personnel to determine the advisability of revising SP-100 SRPS (space reactor power systems) allowable neutron and gamma dose rates in order to reduce the size and mass of the radiation shield and thereby achieve system mass reductions. The survey results indicate that recent developments to increase the radiation tolerance of a limited set of electronics parts do not justify increasing the allowable SP-100 dose rates for electronic components. Specifically, the recent improvements on a limited set of parts do not justify increasing the current SP-100 allowable specifications of 5 x 10 exp 5 rads gamma dose and 1 x 10 exp 13 neutrons/sq cm fluence. However, if the improvements of 108 rads for gammas and 10 exp 15 neutrons/sq cm can be extended to a wide range of parts, significant mass savings would result.

  12. Real-Tme Boron Nitride Erosion Measurements of the HiVHAc Thruster via Cavity Ring-Down Spectroscopy

    NASA Technical Reports Server (NTRS)

    Lee, Brian C.; Yalin, Azer P.; Gallimore, Alec; Huang, Wensheng; Kamhawi, Hani

    2013-01-01

    Cavity ring-down spectroscopy was used to make real-time erosion measurements from the NASA High Voltage Hall Accelerator thruster. The optical sensor uses 250 nm light to measure absorption of atomic boron in the plume of an operating Hall thruster. Theerosion rate of the High Voltage Hall Accelerator thruster was measured for discharge voltages ranging from 330 to 600 V and discharge powers ranging from 1 to 3 kW. Boron densities as high as 6.5 x 10(exp 15) per cubic meter were found within the channel. Using a very simple boronvelocity model, approximate volumetric erosion rates between 5.0 x 10(exp -12) and 8.2 x 10(exp -12) cubic meter per second were found.

  13. The GRADIO spaceborne gravity gradiometer: Development and accommodation

    NASA Technical Reports Server (NTRS)

    Bernard, A.

    1989-01-01

    The European ARISTOTELES mission aims at the determination of the Earth's gravity field at short wavelength with a global coverage. Gravity gradient measurements will be achieved during six months by the GRADIO instrument onboard a dedicated satellite in a near dawn-dusk sun-synchronous orbit at an altitude of 200 km. The objective is an accuracy of better than 5 mgals for gravity anomalies, at ground level for blocks of 1 x 1 deg. According to present knowledge of the potential, the recovery of higher spherical harmonics (degree and order greater than 30) is of main importance. This leads to focus on the variations of the measured components T(sub ij) of the gravity gradient tensor, at frequencies greater than 5 x 10(exp -3) Hz. The resolution, required for the gradiometer is 10(exp -2) Eotvos (i.e., 10(exp -11)/s squared) with an averaging time of 4 s.

  14. Compressible Boundary Layer Predictions at High Reynolds Number using Hybrid LES/RANS Methods

    NASA Technical Reports Server (NTRS)

    Choi, Jung-Il; Edwards, Jack R.; Baurle, Robert A.

    2008-01-01

    Simulations of compressible boundary layer flow at three different Reynolds numbers (Re(sub delta) = 5.59x10(exp 4), 1.78x10(exp 5), and 1.58x10(exp 6) are performed using a hybrid large-eddy/Reynolds-averaged Navier-Stokes method. Variations in the recycling/rescaling method, the higher-order extension, the choice of primitive variables, the RANS/LES transition parameters, and the mesh resolution are considered in order to assess the model. The results indicate that the present model can provide good predictions of the mean flow properties and second-moment statistics of the boundary layers considered. Normalized Reynolds stresses in the outer layer are found to be independent of Reynolds number, similar to incompressible turbulent boundary layers.

  15. Experimental and theoretical study of the ion-ion mutual neutralization reactions Ar++SFn- (n=6, 5, and 4)

    NASA Astrophysics Data System (ADS)

    Bopp, Joseph C.; Miller, Thomas M.; Viggiano, Albert A.; Troe, Jürgen

    2008-08-01

    The ion-ion mutual neutralization reactions Ar++SFn--->Ar+SFn (n=6, 5, and 4) have been studied in a flowing afterglow-Langmuir probe (FALP) apparatus at 300 K and 1 Torr of He buffer gas. Electron concentrations and product ion fractions were measured, and neutralization rate constants of 4.0×10-8, 3.8×10-8, and 4×10-8 cm3 s-1 for SF6-, SF5-, and SF4-, respectively, were derived, with uncertainties of +/-25% (+/-35% for SF4-). During the neutralization process, excited neutrals are generated that are able to dissociate to neutral fragments. In the case of SF6, the formation of SF5 and SF4, and similarly in the case of SF5, the formation of SF4 and SF3 were observed and quantified. The mechanism of primary and secondary reaction was analyzed in detail, and rate constants for the dissociative electron attachments e-+SF5-->F-+SF4 (k=3×10-9 cm3 s-1,+/-40%) and e-+SF3-->F-+SF2 (k=2×10-8 cm3 s-1,+400%,-75%) were also derived. The experimental ion-ion neutralization rate constants were found to be in good agreement with estimates from an optimum two-state double-passage Landau-Zener model. It was also found that energy partitioning in the neutralization is related to the extent of electronic excitation of Ar generated by the electron transfer processes.

  16. Shock-tube thermochemistry tables for high-temperature gases. Volume 5: Carbon dioxide

    NASA Technical Reports Server (NTRS)

    Menard, W. A.; Horton, T. E.

    1971-01-01

    Equilibrium thermodynamic properties and species concentrations for carbon dioxide are tabulated for moving, standing, and reflected shock waves. Initial pressures range from 6.665 to 6665 N/sq m (0.05 to 50.0 torr), and temperatures from 2,000 to over 80,000K. In this study, 20 molecular and atomic species were considered.

  17. Rapid Chill and Fill of a Liquid Hydrogen Tank Demonstrated

    NASA Technical Reports Server (NTRS)

    Kudlac, Maureen T.

    1999-01-01

    The NASA Lewis Research Center, in conjunction with Boeing North American, has been supporting the High Energy Upper Stage (HEUS) program by performing feasibility studies at Lewis Supplemental Multilayer Insulation Research Facility (SMIRF). These tests were performed to demonstrate the feasibility of chilling and filling a tank with liquid hydrogen in under 5 minutes. The goal of the HEUS program is to release a satellite from the shuttle cargo bay and then use a cryogenic (high-energy) upper stage to allow the satellite to achieve final orbit. Because of safety considerations, the propellant tanks for the upper stage will be launched warm and dry. They will be filled from the shuttle's external tank during the mission phase after the solid rocket boosters have jettisoned and prior to jettison of the external tank. Data from previous shuttle missions have been analyzed to ensure that sufficient propellant would be available in the external tank to fill the propellant tank of the proposed vehicle upper stage. Because of mission time-line considerations, the propellant tanks for the upper stage will have to be chilled down and filled in approximately 5 minutes. An existing uninsulated flight weight test tank was installed inside the vacuum chamber at SMIRF, and the chamber was evacuated to the 10(exp -5) torr range to simulate space vacuum conditions in the cargo bay with the doors open. During prerun operations, the facility liquid hydrogen (LH2) supply piping was prechilled with the vent gas bypassing the test article. The liquid hydrogen supply dewar was saturated at local ambient pressure and then pressurized with ambient temperature gaseous helium to the test pressure. A control system was used to ensure that the liquid hydrogen supply pressure was maintained at the test pressure.

  18. Snow White 5 Trench

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image was acquired by NASA's Phoenix Mars Lander's Robotic Arm Camera on the 35th Martian day of the mission, or Sol 34 (June 29, 2008), after the May 25, 2008, landing. This image shows the trench informally called 'Snow White 5.' The trench is 4-to-5 centimeters (about 1.5-to-1.9 inches) deep, 24 centimeters (about 9 inches) wide and 33 centimeters (13 inches) long.

    Snow White 5 is Phoenix's current active digging area after additional trenching, grooming, and scraping by Phoenix's Robotic Arm in the last few sols to trenches informally called Snow White 1, 2, 3, and 4. Near the top center of the image is the Robotic Arm's Thermal and Electrical Conductivity Probe.

    Snow White 5 is located in a patch of Martian soil near the center of a polygonal surface feature, nicknamed 'Cheshire Cat.' The digging site has been named 'Wonderland.'

    This image has been enhanced to brighten shaded areas.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  19. Multilayer Thin Film Polarizer Design for Far Ultraviolet using Induced Transmission and Absorption Technique

    NASA Technical Reports Server (NTRS)

    Kim, Jongmin; Zukic, Muamer; Wilson, Michele M.; Park, Jung Ho; Torr, Douglas G.

    1994-01-01

    Good theoretical designs of far ultraviolet polarizers have been reported using a MgF2/Al/MgF2 three layer structure on a thick Al layer as a substrate. The thicknesses were determined to induce transmission and absorption of p-polarized light. In these designs Al optical constants were used from films produced in ultrahigh vacuum (UHV: 10(exp -10) torr). Reflectance values for polarizers fabricated in a conventional high vacuum (p approx. 10(exp -6 torr)) using the UHV design parameters differed dramatically from the design predictions. Al is a highly reactive material and is oxidized even in a high vacuum chamber. In order to solve the problem other metals have been studied. It is found that a larger reflectance difference is closely related to higher amplitude and larger phase difference of Fresnel reflection coefficients between two polarizations at the boundary of MgF2/metal. It is also found that for one material a larger angle of incidence from the surface normal brings larger amplitude and phase difference. Be and Mo are found good materials to replace Al. Polarizers designed for 121.6 nm with Be at 60 deg and with Mo at 70 deg are shown as examples.

  20. Kinetic and theoretical study of the reaction of Cl atoms with a series of linear thiols

    SciTech Connect

    Garzon, Andres; Albaladejo, Jose

    2008-11-21

    The reactions of Cl with a series of linear thiols: 1-propanethiol (k{sub 1}), 1-butanethiol (k{sub 2}), and 1-pentanethiol (k{sub 3}) were investigated as a function of temperature (in the range of 268-379 K) and pressure (in the range of 50-200 Torr) by laser photolysis-resonance fluorescence. Only 1-propanethiol has previously been studied, but at 1 Torr of total pressure. The derived Arrhenius expressions obtained using our kinetic data were as follows: k{sub 1}=(3.97{+-}0.44)x10{sup -11} exp[(410{+-}36)/T], k{sub 2}=(1.01{+-}0.16)x10{sup -10} exp[(146{+-}23)/T], and k{sub 3}=(1.28{+-}0.10)x10{sup -10} exp[(129{+-}25)/T] (in units of cm{sup 3} molecule{sup -1} s{sup -1}). Moreover, a theoretical insight into mechanisms of these reactions has also been pursued through ab initio Moeller-Plesset second-order perturbation treatment calculations with 6-311G** basis set. Optimized geometries have been obtained for transition states and molecular complexes appearing along the different reaction pathways. Furthermore, molecular energies have been calculated at QCISD(T) level in order to get an estimation of the activation energies. Finally, the nature of the molecular complexes and transitions states is analyzed by using kinetic-potential and natural bond orbital total energy decomposition schemes.

  1. [Photodissociation of Acetylene and Acetone using Step-Scan Time-Resolved FTIR Emission Spectroscopy

    NASA Technical Reports Server (NTRS)

    McLaren, Ian A.; Wrobel, Jacek D.

    1997-01-01

    The photodissociation of acetylene and acetone was investigated as a function of added quenching gas pressures using step-scan time-resolved FTIR emission spectroscopy. Its main components consist of Bruker IFS88, step-scan Fourier Transform Infrared (FTIR) spectrometer coupled to a flow cell equipped with Welsh collection optics. Vibrationally excited C2H radicals were produced from the photodissociation of acetylene in the unfocused experiments. The infrared (IR) emission from these excited C2H radicals was investigated as a function of added argon pressure. Argon quenching rate constants for all C2H emission bands are of the order of 10(exp -13)cc/molecule.sec. Quenching of these radicals by acetylene is efficient, with a rate constant in the range of 10(exp -11) cc/molecule.sec. The relative intensity of the different C2H emission bands did not change with the increasing argon or acetylene pressure. However, the overall IR emission intensity decreased, for example, by more than 50% when the argon partial pressure was raised from 0.2 to 2 Torr at fixed precursor pressure of 160mTorr. These observations provide evidence for the formation of a metastable C2H2 species, which are collisionally quenched by argon or acetylene. Problems encountered in the course of the experimental work are also described.

  2. Implications of Adhesion Studies for Dust Mitigation on Thermal Control Surfaces

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Berkebile, Stephen P.

    2012-01-01

    Experiments measuring the adhesion forces under ultrahigh vacuum conditions (10 (exp -10) torr) between a synthetic volcanic glass and commonly used space exploration materials have recently been described. The glass has a chemistry and surface structure typical of the lunar regolith. It was found that Van der Waals forces between the glass and common spacecraft materials was negligible. Charge transfer between the materials was induced by mechanically striking the spacecraft material pin against the glass plate. No measurable adhesion occurred when striking the highly conducting materials, however, on striking insulating dielectric materials the adhesion increased dramatically. This indicates that electrostatic forces dominate over Van der Waals forces under these conditions. The presence of small amounts of surface contaminants was found to lower adhesive forces by at least two orders of magnitude, and perhaps more. Both particle and space exploration material surfaces will be cleaned by the interaction with the solar wind and other energetic processes and stay clean because of the extremely high vacuum (10 (exp -12) torr) so the atomically clean adhesion values are probably the relevant ones for the lunar surface environment. These results are used to interpret the results of dust mitigation technology experiments utilizing textured surfaces, work function matching surfaces and brushing. They have also been used to reinterpret the results of the Apollo 14 Thermal Degradation Samples experiment.

  3. Determination of the de-excitation probability of argon metastable (1s5 and 1s3) atoms on aluminum, stainless steel, silicon, quartz and Pyrex surfaces

    NASA Astrophysics Data System (ADS)

    Wang, Zhen-Bin; Li, Jiang-Tao; Zhu, Xi-Ming; Pu, Yi-Kang

    2015-03-01

    The de-excitation probability of argon 1s5 and 1s3 metastable atoms on aluminum (alloy 2024), stainless steel (304), silicon (100), quartz (JGS1) and Pyrex surfaces is measured with a low pressure (1-5 mTorr) pulsed capacitively coupled plasma. The de-excitation probability is deduced from the loss rate of the metastable atoms in the late afterglow, which is obtained from the temporal evolution of the metastable atom density measured by laser absorption. Under the low pressure condition, the loss of the metastable atoms is mainly due to volume diffusion and de-excitation on the surface. The measured de-excitation probability for both Ar*(1s5) and Ar*(1s3) atoms ranges from 0.74 to 0.88 on these five materials, with an uncertainty of ±0.11. The measured probabilities on the Pyrex surface are in good agreement with those reported in previous work, and those on aluminum, stainless steel, silicon and quartz surfaces are reported here for the first time.

  4. A study of liquid boric oxide particle growth rates in a gas stream from a simulated jet engine combustor

    NASA Technical Reports Server (NTRS)

    Setze, Paul C

    1957-01-01

    It was experimentally determined that the liquid boric oxide particles leaving a jet engine combustor, burning a boron-containing fuel, will have diameters of 1.0 x 10(exp -5) to 2.0 x 10(exp -5) centimeter. For this size range the particle heat-transfer and drag coefficients are essentially infinite. The results may be applied to any boron-containing fuel. Equations are developed that enable the calculation of the particle size-time history. A study of boric oxide deposition mechanisms is included, and suggestions for decreading deposition rates given.

  5. The Prolate Solar Chromosphere

    NASA Technical Reports Server (NTRS)

    Auchere, F.; Boulade, S.; Koutchmy, S.; Smartt, R. N.; Delaboudiniere, J. P.; Georgakilas, A.; Gurman, J. B.; Artzner, G. E.

    1998-01-01

    We present a comparative analysis of the chromospheric solar limb prolateness, using strictly simultaneous H-alpha, ground-based observations and HeII space-based observations. The typical prolateness is found to be DeltaD/D = 5.5 x 10(exp -3) in HeII and 1.2 x 10(exp -3) in H-alpha. The first measurements in the 30.4 nm HeII line over a period of two years. as well as coronal data, are discussed to explore further the origin of the prolateness and its possible consequences.

  6. RADTRAN 5 user guide.

    SciTech Connect

    Kanipe, Frances L.; Neuhauser, Karen Sieglinde

    2003-07-01

    This User Guide for the RADTRAN 5 computer code for transportation risk analysis describes basic risk concepts and provides the user with step-by-step directions for creating input files by means of either the RADDOG input file generator software or a text editor. It also contains information on how to interpret RADTRAN 5 output, how to obtain and use several types of important input data, and how to select appropriate analysis methods. Appendices include a glossary of terms, a listing of error messages, data-plotting information, images of RADDOG screens, and a table of all data in the internal radionuclide library.

  7. Tests of the Rockwell Si:As Back-Illuminated Blocked-Impurity Band (BIBIB) detectors

    NASA Technical Reports Server (NTRS)

    Wolf, J.; Groezinger, U.; Burgdorf, M.; Salama, A.

    1989-01-01

    Two arrays of Rockwell's Si:As back-illuminated blocked-impurity-band detectors were tested at the Max-Planck-Institute for Astronomy (MPIA) at low background and low temperature for possible use in the astronomical space experiment ISOPHOT. For these measurements special test equipment was put together. A cryostat was mechanically modified to accommodate the arrays and special peripheral electronics was added to a microprocessor system to drive the cold multiplexer and to acquire the output data. The first device, a 16x50 element array on a fan-out board was used to test individual pixels with a trans-impedance-amplifier at a photon background of 10(exp 8) Ph s(-1)cm(-2) and at temperatures of 2.7 to 4.4 K. The noise-equivalent-power NEP is in the range 5 - 7 x 10(exp -18) WHz(exp -1/2), the responsivity is less than or equal to 100 AW(exp -1)(f = 10 Hz). The second device was a 10x50 array including a cold readout electronics of switched FETs (SWIFET). Measurements of this array were done in a background range of 5 x 10(exp 5) to 5 x 10(exp 11) Ph s(exp-1)cm(exp-2) and at operating temperatures between 3.0 and 4.8 K. The NEP ranges from less than 10(exp -18) at the lowest background to 2 x 10(exp -16) WHz(exp -1/2) at the highest flux.

  8. Developmental milestones record - 5 years

    MedlinePlus

    ... Childhood growth milestones - 5 years; Growth milestones for children - 5 years; Well child - 5 years ... skill milestones for a typical 5-year-old child include: Gains about 4 to 5 pounds (1. ...

  9. The EDP-5E

    ERIC Educational Resources Information Center

    Lottero-Perdue, Pamela; Bolotin, Sonja; Benyameen, Ruth; Brock, Erin; Metzger, Ellen

    2015-01-01

    Many preservice and practicing elementary teachers are familiar with the 5E learning cycle. This cycle provides a relatively simple, alliteratively memorable framework for teaching science in which lessons (or even entire units of instruction) consist of five distinct phases: Engagement, Exploration, Explanation, Elaboration/Extension (hereafter,…

  10. SU(5) gravitating monopoles

    NASA Astrophysics Data System (ADS)

    Brihaye, Yves; Ioannidou, Theodora

    2005-03-01

    Spherically symmetric and purely magnetic (i.e. A0 = 0) solutions of the full second-order SU(5) Einstein Yang Mills Higgs equations are constructed using the harmonic map ansatz [1, 2]. In this way the problem reduces to solving a set of ordinary differential equations for the appropriate profile functions.

  11. 5-Year Budget Forecasting.

    ERIC Educational Resources Information Center

    Conyers, John G.; Lingel, George; Piekarski, Robert

    2000-01-01

    Financial planning is the key to providing a high-quality instructional plan. A 5-year financial plan is typically updated by looking at district financial history, future instructional plans, staffing requirements, and revenue projections. Planning assumptions must be clearly understood by the financial team and the community. (MLH)

  12. Sociology 5 Study.

    ERIC Educational Resources Information Center

    Garlock, Jerry C.

    In order to deal with the problem of increasing failures and dropouts and the negative impact of large numbers of students lacking basic reading and language skills on instructional activities and materials, the Sociology Department at El Camino College made eligibility for English 1A a prerequisite for its Sociology 5 course in fall 1975. This…

  13. Accelerators (3/5)

    ScienceCinema

    None

    2016-07-12

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  14. 5-Second Rule

    MedlinePlus

    ... feel tempted by the 5-second rule: A clean-looking floor isn't necessarily clean. A shiny linoleum floor ... cleaner than a 1970s-era carpet. But even clean, dry floors can harbor bacteria. Newly washed floors are only ...

  15. Accelerators (4/5)

    ScienceCinema

    None

    2016-07-12

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  16. Elementary Science: Grade 5.

    ERIC Educational Resources Information Center

    Carroll County Public Schools, Westminster, MD.

    This grade 5 science curriculum guide contains four activity units: (1) mineral identification; (2) earth science; (3) soil analysis; and (4) small friends community. Each unit contains a letter to the parents to introduce the unit, lesson plans, and word searches. The lesson plans list the science processes involved, content objectives,…

  17. Anxiety and DSM-5

    PubMed Central

    Kupfer, David J.

    2015-01-01

    The DSM-5 process, and the publication of DSM-5 in 2013, have had a considerable impact on the classification of anxiety disorders. Major changes included the reorganization of the chapter structure, individual groupings of disorders within each chapter from a life span viewpoint, and the use of specifiers. The DSM-5 chapter on anxiety disorders does not include obsessive-compulsive disorder or post-traumatic stress disorder. The chapter itself now reflects a developmental approach. The text of each disorder has been enhanced with short sections on development and course, risk and prognostic factors, etc. It is expected that the reformulation of anxiety disorders in DSM-5 will lead to greater precision in a variety of ways, as illustrated in the papers in this issue of Dialogues in Clinical Neuroscience. In summary, these changes in the way we classify anxiety disorders reflect our best view on the clinical empirical data and should prove useful in the assessment of specific anxiety disorders. PMID:26487805

  18. BLG and M5

    NASA Astrophysics Data System (ADS)

    Pasti, Paolo; Samsonov, Igor; Sorokin, Dmitri; Tonin, Mario

    2011-05-01

    We discuss the interpretation of the three-dimensional N = 8 superconformal Chern-Simons-matter theory with the gauge group of volume preserving diffeomorphisms as a model describing a six-dimensional self-dual gauge field coupled to scalars and spinors and its possible relation to the M5-brane

  19. Effects of 5-FU.

    PubMed

    Wigmore, Peter M; Mustafa, Sarah; El-Beltagy, Maha; Lyons, Laura; Umka, Jariya; Bennett, Geoff

    2010-01-01

    5-fluorouracil (5-FU) is a chemotherapeutical agent used to treat cancers including breast and colorectal. Working as an antimetabolite to prevent cell proliferation, it primarily inhibits the enzyme thymidylate synthase blocking the thymidine formation required for DNA synthesis. Although having a relatively short half-life (< 30 mins) it readily enters the brain by passive diffusion. Clinically, it is used both as a single agent or in combination with other chemotherapies and has been associated with the long-term side effects of cognitive impairment, known as "chemo brain" or "chemo fog" These accounts have come primarily from patients undergoing treatment for breast cancer who report symptoms including confusion and memory impairment, which can last for months to years. Psychometric studies of patients have suffered from confounding variables, which has led to the use of rodent models to assess the cognitive effects of this drug. Researchers have used behavioral and physiological tests including the Morris water maze, novel object location/recognition tests, shock motivated T-maze, sensory gating and conditioning, to investigate the effect of this drug on cognition. The variety of cognitive tests and the difference in dosing and administration of 5-FU has led to varied results, possibly due to the different brain regions associated with each test and the subtlety of the drug's effect, but overall these studies indicates that 5-FU has a negative effect on memory, executive function and sensory gating. 5-FU has also been demonstrated to have biochemical and structural changes on specific regions of the brain. Evidence shows it can induce apoptosis and depress cell proliferation in the neurogenic regions of the adult brain including the sub granular zone (SGZ) within the hippocampus and in oligodendrocyte precursor populations within white matter tracts. Furthermore, investigations indicate levels ofdoublecortin, a marker for newly formed neurons and brain derived

  20. 4 CFR 5.5 - Travel, transportation, and subsistence.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 4 Accounts 1 2013-01-01 2013-01-01 false Travel, transportation, and subsistence. 5.5 Section 5.5 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM COMPENSATION § 5.5 Travel, transportation, and subsistence. The provisions of chapter 57 of title 5, U.S. Code and the implementing regulations for...

  1. 4 CFR 5.5 - Travel, transportation, and subsistence.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 4 Accounts 1 2010-01-01 2010-01-01 false Travel, transportation, and subsistence. 5.5 Section 5.5 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM COMPENSATION § 5.5 Travel, transportation, and subsistence. The provisions of chapter 57 of title 5, U.S. Code and the implementing regulations for...

  2. 4 CFR 5.5 - Travel, transportation, and subsistence.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 4 Accounts 1 2012-01-01 2012-01-01 false Travel, transportation, and subsistence. 5.5 Section 5.5 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM COMPENSATION § 5.5 Travel, transportation, and subsistence. The provisions of chapter 57 of title 5, U.S. Code and the implementing regulations for...

  3. 4 CFR 5.5 - Travel, transportation, and subsistence.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 4 Accounts 1 2014-01-01 2013-01-01 true Travel, transportation, and subsistence. 5.5 Section 5.5 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM COMPENSATION § 5.5 Travel, transportation, and subsistence. The provisions of chapter 57 of title 5, U.S. Code and the implementing regulations for...

  4. 4 CFR 5.5 - Travel, transportation, and subsistence.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 4 Accounts 1 2011-01-01 2011-01-01 false Travel, transportation, and subsistence. 5.5 Section 5.5 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM COMPENSATION § 5.5 Travel, transportation, and subsistence. The provisions of chapter 57 of title 5, U.S. Code and the implementing regulations for...

  5. Decamethylcyclopentasiloxane (D5).

    PubMed

    2017-01-01

    Decamethylcyclopentasiloxane (D5; CAS No. 541-02-6) is a precursor in the production of siloxane polymers for industry and medicine and is a carrier ingredient in many toiletries and cosmetics. D5 has a relatively low order of toxicity following acute administration via the oral, dermal, and inhalation routes of exposure. It is not considered to be a dermal or eye irritant or a dermal sensitizer. There is no appreciable dermal absorption of D5 based on results from in vivo and in vitro studies. It has not been shown to be genotoxic/mutagenic when tested in a number of short-term in vitro and in vivo assays and did not cause reproductive or developmental toxicity in rats. Inhalation exposure of rats to 160 ppm D5 for up to 24 months produced adverse effects in the liver (weight changes and hepatocellular hypertrophy) and uterus (increased incidence of endometrial adenocarcinoma, endometrial adenoma, and adenomatous polyps in several animals); however, the results of recent mode-of-action studies are consistent with a uterine tumorigenesis mechanism that is not relevant for humans. Based on the results of the chronic inhalation study, 160 ppm was determined to be the no-observed-adverse-effect level (NOAEL) and was selected as the point of departure for the derivation of the workplace environmental exposure level (WEEL®) value. This NOAEL was adjusted to account for interindividual variability and residual uncertainty regarding upper respiratory tract changes still occurring at 160 ppm. The resulting 8-h time-weighted average WEEL value of 10 ppm is expected to provide a significant margin of safety against any potential adverse health effects in workers exposed to airborne D5.

  6. ADCY5-related dyskinesia

    PubMed Central

    Chen, Dong-Hui; Méneret, Aurélie; Friedman, Jennifer R.; Korvatska, Olena; Gad, Alona; Bonkowski, Emily S.; Stessman, Holly A.; Doummar, Diane; Mignot, Cyril; Anheim, Mathieu; Bernes, Saunder; Davis, Marie Y.; Damon-Perrière, Nathalie; Degos, Bertrand; Grabli, David; Gras, Domitille; Hisama, Fuki M.; Mackenzie, Katherine M.; Swanson, Phillip D.; Tranchant, Christine; Vidailhet, Marie; Winesett, Steven; Trouillard, Oriane; Amendola, Laura M.; Dorschner, Michael O.; Weiss, Michael; Eichler, Evan E.; Torkamani, Ali; Roze, Emmanuel

    2015-01-01

    Objective: To investigate the clinical spectrum and distinguishing features of adenylate cyclase 5 (ADCY5)–related dyskinesia and genotype–phenotype relationship. Methods: We analyzed ADCY5 in patients with choreiform or dystonic movements by exome or targeted sequencing. Suspected mosaicism was confirmed by allele-specific amplification. We evaluated clinical features in our 50 new and previously reported cases. Results: We identified 3 new families and 12 new sporadic cases with ADCY5 mutations. These mutations cause a mixed hyperkinetic disorder that includes dystonia, chorea, and myoclonus, often with facial involvement. The movements are sometimes painful and show episodic worsening on a fluctuating background. Many patients have axial hypotonia. In 2 unrelated families, a p.A726T mutation in the first cytoplasmic domain (C1) causes a relatively mild disorder of prominent facial and hand dystonia and chorea. Mutations p.R418W or p.R418Q in C1, de novo in 13 individuals and inherited in 1, produce a moderate to severe disorder with axial hypotonia, limb hypertonia, paroxysmal nocturnal or diurnal dyskinesia, chorea, myoclonus, and intermittent facial dyskinesia. Somatic mosaicism is usually associated with a less severe phenotype. In one family, a p.M1029K mutation in the C2 domain causes severe dystonia, hypotonia, and chorea. The progenitor, whose childhood-onset episodic movement disorder almost disappeared in adulthood, was mosaic for the mutation. Conclusions: ADCY5-related dyskinesia is a childhood-onset disorder with a wide range of hyperkinetic abnormal movements. Genotype-specific correlations and mosaicism play important roles in the phenotypic variability. Recurrent mutations suggest particular functional importance of residues 418 and 726 in disease pathogenesis. PMID:26537056

  7. A search for gamma-ray lines from the decay of Fe-59 in Supernova 1987A

    NASA Technical Reports Server (NTRS)

    Harris, M. J.; Leising, M. D.

    1994-01-01

    We have searched spectra of Supernova (SN) 1987A, accumulated during several 35-day intervals after the explosion by the Solar Maximum Mission (SMM) Gamma Ray Spectrometer (GRS), for gamma-ray lines at 1.099 and 1.292 MeV from the decay of Fe-59 which may have been produced in the progenitor's helium shell. We find no evidence for these lines, down to 3-sigma upper limits approximately = 7 x 10(exp -4) gamma/sq cm/s for the 1.099 MeV line, or approximately = 4.5 x 10(exp -4) gamma/sq cm/s for the 1.292 MeV line, in any 35-day interval. We derive a conservative 3-sigma upper limit on the mass fraction of Fe-59 in the helium shell of 2.9 x 10(exp -3).

  8. Origin of pulsed emission from the young supernova remnant SN 1987A

    NASA Technical Reports Server (NTRS)

    Ruderman, M.; Kluzniak, W.; Shaham, Jacob

    1989-01-01

    To overcome difficulties in understanding the origin of the submillisecond optical pulses from SN 1987A a model similar to that of Kundt and Krotscheck for pulsed synchrotron emission from the Crab was applied. The interaction of the expected ultrarelativistic e(sup + or -) pulsar wind with the pulsar dipole electromagnetic wave reflected from the walls of a pulsar cavity within the SN 1987A nubula can generate pulsed optical emission with efficiency at most eta(sub max) is approximately equal to 10(exp -3). The maximum luminosity of the source is reproduced and other observational constraints can be satisfied for an average wind energy flow is approximately equal to 10(exp 38) erg/(s steradian) and for electron Lorentz factor gamma is approximately equal to 10(exp 5). This model applied to the Crab yields pulsations of much lower luminosity and frequency.

  9. Possible applications of atomic frequency standards with an internal high resolution digital synthesizer

    NASA Technical Reports Server (NTRS)

    Detoma, E.; Stern, A.

    1993-01-01

    The applications of Atomic Frequency Standards with an internal synthesizer (thereafter referred as 'Synthesized Frequency Standards or Oscillators') with a special emphasis on the Rb oscillator are reviewed. A fractional frequency synthesizer, developed by SEPA, was incorporated in the Frequency Locked Loop of a TFL Rubidium Frequency Standard. This combination allows a frequency settability in steps of 1.5 x 10(exp -12) (optional 1 x 10(exp -13) over a range of 6 x 10(exp -9) without having to resort to change the C-field to tune the output frequency of the device. This capability, coupled to the excellent short term stability of the Rb frequency standard, opens new possibilities for time and frequency users in the various fields (time metrology, navigation, communication, etc.) in which stable frequency standards find their application.

  10. Material properties and device evaluations of ECR-deposited a-Si:H and a-SiC:H films

    NASA Technical Reports Server (NTRS)

    Shing, Y. H.; Pool, F. S.; Essick, J. M.

    1991-01-01

    Device-quality a-Si:H and a-SiC:H films have been deposited using electron cyclotron resonance (ECR) microwave plasmas of SiH4, CH4, and H2 mixtures. Typical material properties of ECR-deposited, photosensitive a-Si:H films are: (1) high photosensitivity up to 2 x 106 with a photoconductivity of 10 exp -5 to 10 exp -4/(Ohm-cm), (2) a Tauc gap of 1.75 to 1.85 eV, (3) an Urbach slope of 50-60 meV determined by the constant photocurrent method, and (4) an integrated defect density of 1-2 x 10 exp 16/cu cm determined by junction capacitance measurements. Highly conductive, p-type a-SiC:H films have been produced by ECR plasmas with a conductivity of 0.2/(Ohm-cm).

  11. The effects of electron and proton radiation on GaSb infrared solar cells

    NASA Technical Reports Server (NTRS)

    Gruenbaum, P. E.; Avery, J. E.; Fraas, L. M.

    1991-01-01

    Gallium antimonide (GaSb) infrared solar cells were exposed to 1 MeV electrons and protons up to fluences of 1 times 10(exp 15) cm (-2) and 1 times 10(exp 12) cm (-2) respectively. In between exposures, current voltage and spectral response curves were taken. The GaSb cells were found to degrade slightly less than typical GaAs cells under electron irradiation, and calculations from spectral response curves showed that the damage coefficient for the minority carrier diffusion length was 3.5 times 10(exp 8). The cells degraded faster than GaAs cells under proton irradiation. However, researchers expect the top cell and coverglass to protect the GaSb cell from most damaging protons. Some annealing of proton damage was observed at low temperatures (80 to 160 C).

  12. A Noachian/Hesperian Hiatus and Erosive Reactivation of Martian Valley Networks

    NASA Technical Reports Server (NTRS)

    Irwin, R. P., III.; Maxwell, T. A.; Howard, A. D.; Craddock, R. A.; Moore, J. M.

    2005-01-01

    Despite new evidence for persistent flow and sedimentation on early Mars, it remains unclear whether valley networks were active over long geologic timescales (10(exp 5)-10(exp 8) yr), or if flows were persistent only during multiple discrete episodes of moderate (approx. 10(exp 4) yr) to short (<10 yr) duration. Understanding the long-term stability/variability of valley network hydrology would provide an important control on paleoclimate and groundwater models. Here we describe geologic evidence for a hiatus in highland valley network activity while the fretted terrain formed, followed by a discrete reactivation of persistent (but possibly variable) erosive flows. Additional information is included in the original extended abstract.

  13. Gamma-Ray, Cosmic Ray and Neutrino Tests of Lorentz Invariance and Quantum Gravity Models

    NASA Technical Reports Server (NTRS)

    Stecker, Floyd

    2011-01-01

    High-energy astrophysics observations provide the best possibilities to detect a very small violation of Lorentz invariance such as may be related to the structure of space-time near the Planck scale of approximately 10(exp -35) m. I will discuss here the possible signatures of Lorentz invariance violation (LIV) from observations of the spectra, polarization, and timing of gamma-rays from active galactic nuclei and gamma-ray bursts. Other sensitive tests are provided by observations of the spectra of ultrahigh energy cosmic rays and neutrinos. Using the latest data from the Pierre Auger Observatory one can already derive an upper limit of 4.5 x 10(exp -23) to the amount of LIV of at a proton Lorentz factor of approximately 2 x 10(exp 11). This result has fundamental implications for quantum gravity models. I will also discuss the possibilities of using more sensitive space based detection techniques to improve searches for LIV in the future.

  14. Optical absorption by free holes in heavily doped GaAs

    NASA Technical Reports Server (NTRS)

    Huberman, M. L.; Ksendzov, A.; Larsson, A.; Terhune, R.; Maserjian, J.

    1991-01-01

    Optical absorption in p-type GaAs with hole concentrations between 10 exp 19 and 10 exp 20/cu cm has been measured for wavelengths between 2 and 20 microns and compared with results of theoretical calculations. In contrast to previous measurements at lower doping levels, the occupied hole states are far from the zone center, where the heavy- and light-hole bands become parallel. This gives rise to a large joint density of states for optical transitions. It is found that the overall magnitude of the observed absorption is explained correctly by the theory, with both the free-carrier (indirect) and the inter-valence-band (direct) transitions contributing significantly to the total absorption. The strength of the absorption (a about 20,000/cm for N(A) = 5 x 10 exp 19/cu cm) is attractive for long-wavelength infrared-detector applications.

  15. InGaAs/InP solar cells for space application

    NASA Technical Reports Server (NTRS)

    Karlina, L. B.; Kazantsev, A. B.; Kozlovskii, V. V.; Mokina, I. A.; Shvarts, M. Z.

    1995-01-01

    The effects of irradiation of In(0.53)Ga(0.47)As/InP (InGaAs/InP) solar cells illuminated through a transparent InP substrate with 1 MeV electrons were measured. These solar cells were developed for bottom cells in tandem solar photovoltaic cell structures. Some InGaAs/InP heterostructures with four layers were grown by liquid phase epitaxy. The structure of the solar cells allowed lightly doped materials in n and p photoactive layers to be used. The base dopant levels ranged from 1.10(exp 17) to 5.10(exp 17) cm(exp -3). The open circuit voltage and the short circuit current were moderately degraded after irradiation with 10(exp 16) cm(exp-2) 1 MeV electrons. This behavior is explained in terms of the device structure and the n and p layer thicknesses.

  16. An accurate Galactic N(sub H) map of the north ecliptic pole

    NASA Technical Reports Server (NTRS)

    Elvis, Martin; Lockman, Felix J.; Fassnacht, C.

    1994-01-01

    The Galactic HI column density was measured at 21 min angular resolution over an 8 deg x 9 deg region centered on the north ecliptic pole. Over the region N(sub H) varies smoothly between 3 x 10(exp 20) atoms/sq cm and 8 x 10(exp 20) atoms/sq cm; some structure is seen over most of the map on an 0.5 - 1 deg scale. There are other possible sources of interstellar opacity in this direction which may add an equivalent 10(exp 20)/sq cm of HI. We evaluate the effect of uncertainties in the HI column density on implied X-ray fluxes of extragalactic objects.

  17. A Preliminary Model for Spacecraft Propulsion Performance Analysis Based on Nuclear Gain and Subsystem Mass-Power Balances

    NASA Technical Reports Server (NTRS)

    Chakrabarti, S.; Schmidt, G. R.; Thio, Y. C.; Hurst, C. M.

    1999-01-01

    Rapid transportation of human crews to destinations throughout the solar system will require propulsion systems having not only very high exhaust velocities (i.e., I(sub sp) >= 10(exp 4) to 10(exp 5) sec) but also extremely low mass-power ratios (i.e., alpha <= 10(exp -2) kg/kW). These criteria are difficult to meet with electric propulsion and other power-limited systems, but may be achievable with propulsion concepts that use onboard power to produce a net gain in energy via fusion or some other nuclear process. This paper compares the fundamental performance of these gain-limited systems with that of power-limited systems, and determines from a generic power balance the gains required for ambitious planetary missions ranging up to 100 AU. Results show that energy gain reduces the required effective mass-power ratio of the system, thus enabling shorter trip times than those of power-limited concepts.

  18. Documenting Surface and Sub-surface Volatiles While Drilling in Frozen Lunar Simulant

    NASA Technical Reports Server (NTRS)

    Roush, T. L.; Cook, A. M.; Colaprete, A.; Bielawski, R.; Fritzler, E.; Benton, J.; White, B.; Forgione, J.; Kleinhenz, J.; Smith, J.; Paulsen, G.; Zacny, K.; McMurray, R.

    2017-01-01

    NASA's Resource Prospector (RP) mission is intended to characterize the three-dimensional nature of volatiles in lunar polar regions and permanently shadowed regions. RP is slated to carry two instruments for prospecting purposes. These include the Neutron Spectrometer System (NSS) and Near-Infrared Volatile Spectrometer System (NIRVSS). A Honybee Robotics drill (HRD) is intended to sample to depths of 1 m, and deliver a sample to a crucible that is processed by the Oxygen Volatile Extraction Node (OVEN) where the soil is heated and evolved gas is delivered to the gas chromatograph / mass spectrometer of the Lunar Advanced Volatile Analysis system (LAVA). For several years, tests of various sub-systems have been undertaken in a large cryo-vacuum chamber facility (VF-13) located at Glenn Research Center. In these tests a large tube (1.2 m high x 25.4 cm diameter) is filled with lunar simulant, NU-LHT-3M, prepared with known abundances of water. There are thermo-couples embedded at different depths, and also across the surface of the soil tube. The soil tube is placed in the chamber and cooled with LN2 as the pressure is reduced to approx.5-6x10(exp -6) Torr. Here we discuss May 2016 tests where two soil tubes were prepared and placed in the chamber. Also located in the chamber were 5 crucibles, an Inficon mass spectrometer, and a trolly permitting x-y translation, where the HRD and NIRVSS, were mounted. The shroud surrounding the soil tube was held at different temperatures for each tube to simulate a warm and cold lunar environment.

  19. Spiral Orbit Tribometer

    NASA Technical Reports Server (NTRS)

    Pepper, Stephen V.; Jones, William R., Jr.; Kingsbury, Edward; Jansen, Mark J.

    2007-01-01

    The spiral orbit tribometer (SOT) bridges the gap between full-scale life testing and typically unrealistic accelerated life testing of ball-bearing lubricants in conjunction with bearing ball and race materials. The SOT operates under realistic conditions and quickly produces results, thereby providing information that can guide the selection of lubricant, ball, and race materials early in a design process. The SOT is based upon a simplified, retainerless thrust bearing comprising one ball between flat races (see figure). The SOT measures lubricant consumption and degradation rates and friction coefficients in boundary lubricated rolling and pivoting contacts. The ball is pressed between the lower and upper races with a controlled force and the lower plate is rotated. The combination of load and rotation causes the ball to move in a nearly circular orbit that is, more precisely, an opening spiral. The spiral s pitch is directly related to the friction coefficient. At the end of the orbit, the ball contacts the guide plate, restoring the orbit to its original radius. The orbit is repeatable throughout the entire test. A force transducer, mounted in-line with the guide plate, measures the force between the ball and the guide plate, which directly relates to the friction coefficient. The SOT, shown in the figure, can operate in under ultra-high vacuum (10(exp -9) Torr) or in a variety of gases at atmospheric pressure. The load force can be adjusted between 45 and 450 N. By varying the load force and ball diameter, mean Hertzian stresses between 0.5 and 5.0 GPa can be obtained. The ball s orbital speed range is between 1 and 100 rpm.

  20. TANK 5 SAMPLING

    SciTech Connect

    Vrettos, N; William Cheng, W; Thomas Nance, T

    2007-11-26

    Tank 5 at the Savannah River Site has been used to store high level waste and is currently undergoing waste removal processes in preparation for tank closure. Samples were taken from two locations to determine the contents in support of Documented Safety Analysis (DSA) development for chemical cleaning. These samples were obtained through the use of the Drop Core Sampler and the Snowbank Sampler developed by the Engineered Equipment & Systems (EES) group of the Savannah River National Laboratory (SRNL).