Science.gov

Sample records for 20 100 kilometer kuiper

  1. MEASURING THE ABUNDANCE OF SUB-KILOMETER-SIZED KUIPER BELT OBJECTS USING STELLAR OCCULTATIONS

    SciTech Connect

    Schlichting, Hilke E.; Ofek, Eran O.; Gal-Yam, Avishay; Sari, Re'em; Nelan, Edmund P.; Livio, Mario; Wenz, Michael; Muirhead, Philip; Javanfar, Nikta

    2012-12-20

    We present here the analysis of about 19,500 new star hours of low ecliptic latitude observations (|b| {<=} 20 Degree-Sign ) obtained by the Hubble Space Telescope's Fine Guidance Sensors over a time span of more than nine years, which is in addition to the {approx}12, 000 star hours previously analyzed by Schlichting et al. Our search for stellar occultations by small Kuiper Belt Objects (KBOs) yielded one new candidate event corresponding to a body with a 530 {+-} 70 m radius at a distance of about 40 AU. Using bootstrap simulations, we estimate a probability of Almost-Equal-To 5% that this event is due to random statistical fluctuations within the new data set. Combining this new event with the single KBO occultation reported by Schlichting et al. we arrive at the following results: (1) the ecliptic latitudes of 6. Degree-Sign 6 and 14. Degree-Sign 4 of the two events are consistent with the observed inclination distribution of larger, 100-km-sized KBOs. (2) Assuming that small, sub-kilometer-sized KBOs have the same ecliptic latitude distribution as their larger counterparts, we find an ecliptic surface density of KBOs with radii larger than 250 m of N(r > 250 m) = 1.1{sup +1.5}{sub -0.7} Multiplication-Sign 10{sup 7} deg{sup -2}; if sub-kilometer-sized KBOs have instead a uniform ecliptic latitude distribution for -20 Degree-Sign < b < 20 Degree-Sign then N(r > 250 m) = 4.4{sup +5.8}{sub -2.8} Multiplication-Sign 10{sup 6} deg{sup -2}. This is the best measurement of the surface density of sub-kilometer-sized KBOs to date. (3) Assuming the KBO size distribution can be well described by a single power law given by N(> r){proportional_to}r{sup 1-q}, where N(> r) is the number of KBOs with radii greater than r, and q is the power-law index, we find q = 3.8 {+-} 0.2 and q = 3.6 {+-} 0.2 for a KBO ecliptic latitude distribution that follows the observed distribution for larger, 100-km-sized KBOs and a uniform KBO ecliptic latitude distribution for -20 Degree

  2. Structure of Mars' Atmosphere up to 100 Kilometers from the Entry Measurements of Viking 2.

    PubMed

    Seiff, A; Kirk, D B

    1976-12-11

    The Viking 2 entry science data on the structure of Mars' atmosphere up to 100 kilometers define a morning atmosphere with an isothermal region near the surface; a surface pressure 10 percent greater than that recorded simultaneously at the Viking 1 site, which implies a landing site elevation lower by 2.7 kilometers than the reference ellipsoid; and a thermal structure to 100 kilometers at least qualitatively consistent with pre-Viking modeling of thermal tides. The temperature profile exhibits waves whose amplitude grows with altitude, to approximately 25 degrees K at 90 kilometers. These waves are believed to be a consequence of layered vertical oscillations and associated heating and cooling by compression and expansion, excited by the daily thermal cycling of the planet surface. As is necessary for gravity wave propagation, the atmosphere is stable against convection, except possibly in some very local regions. Temperature is everywhere appreciably above the carbon dioxide condensation boundary at both landing sites, precluding the occurrence of carbon dioxide hazes in northern summer at latitudes to at least 50 degrees N. Thus, ground level mists seen in these latitudes would appear to be condensed water vapor.

  3. Kuiper Crater

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The Mariner 10 Television-Science Team has proposed the name 'Kuiper' for this very conspicuous bright Mercury crater (top center) on the rim of a larger older crater. Prof. Gerard P. Kuiper, a pioneer in planetary astronomy and a member of the Mariner 10 TV team, died December 23, 1973, while the spacecraft was enroute to Venus and Mercury. Mariner took this picture (FDS 27304) from 88,450 kilometers (55,000 miles) some 2 1/2 hours before it passed Mercury on March 29. The bright-floored crater, 41 kilometers (25 miles) in diameter, is the center of a very large bright are which could be seen in pictures sent from Mariner 10 while Mercury was more than two million miles distant. The larger crater is 80 kilometers (50 miles) across.

    The Mariner 10 mission, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, explored Venus in February 1974 on the way to three encounters with Mercury-in March and September 1974 and in March 1975. The spacecraft took more than 7,000 photos of Mercury, Venus, the Earth and the Moon.

    Image Credit: NASA/JPL/Northwestern University

  4. 100-micron array polarimetry from the Kuiper Airborne Observatory - Instrumentation, techniques, and first results

    NASA Technical Reports Server (NTRS)

    Platt, S. R.; Hildebrand, R. H.; Pernic, R. J.; Davidson, J. A.; Novak, G.

    1991-01-01

    The University of Chicago far-infrared array polarimeter, 'STOKES', is the first multiple-beam polarimeter for far-infrared astronomy. Observations are made from the NASA Kuiper Airborne Observatory. Two orthogonal components of linear polarization are detected simultaneously by corresponding pairs of bolometers in two 32-detector arrays. Novel observing and data-analysis techniques are used to overcome the inherent difficulties of array polarimetry. Results from the first observing flights with the new instrument are reported for the molecular clouds W3 and W51. The measurements show that the magnetic-field structure in both clouds is nonuniform on the scale of 0.5-1.5 pc. This is consistent with molecular line and Zeeman observations that indicate the presence of turbulent velocities and significant small-scale structure. Preliminary results from the second flight series have yielded approximately 40 new measurements in the Sgr A complex. These results indicate that modifications made since the first flights have significantly improved the performance of STOKES.

  5. Distribution and fluxes of aggregates >100 μm in the upper kilometer of the South-Eastern Pacific

    NASA Astrophysics Data System (ADS)

    Guidi, L.; Gorsky, G.; Claustre, H.; Miquel, J. C.; Picheral, M.; Stemmann, L.

    2008-09-01

    Large sinking particles transport organic and inorganic matter into the deeper layers of the oceans. Between 70 and 90% of the aggregates exported from the surface mixed layer are disaggregated within the upper 1000 m. This decrease with depth indicates that fragmentation and remineralization processes are intense during sedimentation. Generally, the estimates of vertical flux rely on sediment trap data but difficulties inherent in their design limit the reliability of this information. During the BIOSOPE study in the south-eastern Pacific, 76 vertical casts using the Underwater Video Profiler (UVP) and deployments of drifting sediment traps provided an opportunity to fit the UVP data to sediment trap flux measurements. We applied the calculated UVP flux in the upper 1000 m to the whole 8000 km BIOSOPE transect. Comparison between the large particulate material (LPM) abundance and the estimated fluxes from both UVP and sediment traps showed different patterns in different regions. On the western end of the BIOSOPE section the standing stock of particles in the surface layer was high but the export between 150 and 250 m was low. Below this layer the flux values increased. High values of about 30% of the calculated UVP maximum surface zone flux were observed below 900 m at the HNLC station. The South Pacific Gyre exported about 2 mg m-2 d-1. While off Chilean coast 95% of the surface mixed layer matter was disaggregated, remineralized or advected in the upper kilometer, 20% of the surface zone flux was observed below 900 m near the Chilean coast. These results suggest that the export to deep waters is spatially heterogeneous and related to the different biotic and abiotic factors.

  6. Community Composition, Toxigenicity, and Environmental Conditions during a Cyanobacterial Bloom Occurring along 1,100 Kilometers of the Murray River

    PubMed Central

    Al-Tebrineh, Jamal; Merrick, Chester; Ryan, David; Humpage, Andrew; Bowling, Lee

    2012-01-01

    A cyanobacterial bloom impacted over 1,100 km of the Murray River, Australia, and its tributaries in 2009. Physicochemical conditions in the river were optimal to support a bloom at the time. The data suggest that at least three blooms occurred concurrently in different sections of the river, with each having a different community composition and associated cyanotoxin profile. Microscopic and genetic analyses suggested the presence of potentially toxic Anabaena circinalis, Microcystis flos-aquae, and Cylindrospermopsis raciborskii at many locations. Low concentrations of saxitoxins and cylindrospermopsin were detected in Anabaena and Cylindrospermopsis populations. A multiplex quantitative PCR was used, employing novel oligonucleotide primers and fluorescent TaqMan probes, to examine bloom toxigenicity. This single reaction method identified the presence of the major cyanotoxin-producing species present in these environmental samples and also quantified the various toxin biosynthesis genes. A large number of cells present throughout the bloom were not potential toxin producers or were present in numbers below the limit of detection of the assay and therefore not an immediate health risk. Potential toxin-producing cells, possessing the cylindrospermopsin biosynthesis gene (cyrA), predominated early in the bloom, while those possessing the saxitoxin biosynthesis gene (sxtA) were more common toward its decline. In this study, the concentrations of cyanotoxins measured via enzyme-linked immunosorbent assay (ELISA) correlated positively with the respective toxin gene copy numbers, indicating that the molecular method may be used as a proxy for bloom risk assessment. PMID:22081581

  7. Comet 103P/Hartley's volatiles within 100 kilometers: Sources of water and volatile dependence on illumination

    NASA Astrophysics Data System (ADS)

    Feaga, L.; Sunshine, J.; Protopapa, S.; A'Hearn, M.; Farnham, T.; Kelley, M.; Besse, S.; Groussin, O.

    2014-07-01

    Deep Impact acquired unique rotational data set during its close flyby of the hyperactive comet 103P/Hartley 2, the target of the extended DIXI mission (A'Hearn et al., 2011). The closest approach, on November 4, 2010, provided an opportunity to study spatial distribution and absolute abundance changes in gas emission very near the nucleus (< 100 km) as a function of rotation and illumination. In particular, the HRI-IR spectrometer was used to monitor the coma from 1.05--4.85 microns throughout the encounter. Spatially-resolved infrared scans were acquired every 2 hours over the 18 hours prior to closest approach and every 30 minutes for 2 days after closest approach. Water vapor at 2.7 microns, carbon dioxide at 4.3 microns, and bulk organics at ˜3.4 microns were the dominant emission bands detected in these spectra and their distribution was found to be highly asymmetric and variable. In particular, the distribution maps and radial profiles from the 8 hours following closest approach, approximately half of the 18.4 hour period of the comet, are unique and provide high spatial resolution ranging from 0.2--3.5 km/pixel. These data allow us to explore correlations among the volatiles and the role of extended sources due to water ice sublimation in the coma. These data will also help to quantify the heterogeneity of the outgassing, explore correlations with illumination, and better locate specific source regions on the nucleus of Hartley 2. Results to date indicate that carbon dioxide production is tied to the small lobe of the nucleus and persists, although reduced, even when this small lobe is on the night side i.e., not illuminated, suggesting that the small lobe is compositionally distinct. Bulk organics are found to be highly correlated to carbon dioxide. In contrast, water is seen to be a balance of up to three sources. The first component is direct sublimation from the waist region of the nucleus and is highly variable and depends on illumination. The waist

  8. 27 CFR 20.100 - General.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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  9. 49 CFR 179.100-20 - Stamping.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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  10. 49 CFR 179.100-20 - Stamping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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  11. 49 CFR 179.100-20 - Stamping.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Stamping. 179.100-20 Section 179.100-20 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for...

  12. 50 CFR 20.100 - General provisions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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  13. 50 CFR 20.100 - General provisions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Annual Seasons, Limits, and Shooting Hours Schedules § 20.100... schedules are established for seasons, daily bag and possession limits, and shooting (or hawking)...

  14. 50 CFR 20.100 - General provisions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Annual Seasons, Limits, and Shooting Hours Schedules § 20.100... schedules are established for seasons, daily bag and possession limits, and shooting (or hawking)...

  15. 50 CFR 20.100 - General provisions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Annual Seasons, Limits, and Shooting Hours Schedules § 20.100... schedules are established for seasons, daily bag and possession limits, and shooting (or hawking)...

  16. 50 CFR 20.100 - General provisions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Annual Seasons, Limits, and Shooting Hours Schedules § 20.100... schedules are established for seasons, daily bag and possession limits, and shooting (or hawking)...

  17. 27 CFR 20.100 - General.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... TREASURY LIQUORS DISTRIBUTION AND USE OF DENATURED ALCOHOL AND RUM Formulas and Statements of Process Approval Policies § 20.100 General. (a) In addiition to the limitations in this part, and if necessary to..., samples, or statements of process means only that they meet the standards of the Alcohol and Tobacco Tax...

  18. 49 CFR 179.100-20 - Stamping.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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  19. Population of the Scattered Kuiper Belt.

    PubMed

    Trujillo; Jewitt; Luu

    2000-02-01

    We present the discovery of three new scattered Kuiper Belt objects (SKBOs) from a wide-field survey of the ecliptic. This continuing survey has to date covered 20.2 deg2 to a limiting red magnitude of 23.6. We combine the data from this new survey with an existing survey conducted at the University of Hawaii 2.2 m telescope to constrain the number and mass of the SKBOs. The SKBOs are characterized by large eccentricities, perihelia near 35 AU, and semimajor axes greater than 50 AU. Using a maximum likelihood model, we estimate the total number of SKBOs larger than 100 km in diameter to be N=&parl0;3.1+1.9-1.3&parr0;x104 (1 sigma errors) and the total mass of SKBOs to be M approximately 0.05 M plus sign in circle, demonstrating that the SKBOs are similar in number and mass to the Kuiper Belt inside 50 AU.

  20. Kuipers in Node 1

    NASA Image and Video Library

    2012-05-15

    ISS031-E-157791 (15 May 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 31 flight engineer, conducts a water sampling analysis in the Unity node of the International Space Station.

  1. Beyond the Kuiper Belt Edge

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott

    2011-01-01

    Of the thousands of known objects beyond Neptune, only one has a perihelion significantly beyond 50 AU, Sedna at 75 AU. Kuiper Belt surveys to date have not been optimized to survey beyond the Kuiper Belt edge at 50 AU. Most of these surveys either did not go faint enough, did not have the required long cadence to detect very slow moving objects or covered too small of an area of sky. The dynamical and physical properties of objects in this region offer key constraints on the formation and evolution of our solar system. In order to probe the Sedna like population of objects with moderate radii (100 km) we propose a deep wide-field outer solar system survey. This survey will allow us to determine if the objects beyond 50 AU are fainter than expected, if there is truly a dearth of objects, or if the Kuiper Belt continues again after some sizable gap possibly caused by a planet sized object. We will be able to examine the origin of Sedna and determine if this eccentric, distant body is unique (as once believed for Pluto) or just the first of a new class of object in the outer Solar System. We will also explore the Neptune Trojans and scattered disk populations through the survey.

  2. Beyond the Kuiper Belt Edge

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott; Trujillo, Chad

    2012-02-01

    Of the thousands of known objects beyond Neptune, only one has a perihelion significantly beyond 50 AU, Sedna at 75 AU. Kuiper Belt surveys to date have not been optimized to survey beyond the Kuiper Belt edge at 50 AU. Most of these surveys either did not go faint enough, did not have the required long cadence to detect very slow moving objects or covered too small of an area of sky. The dynamical and physical properties of objects in this region offer key constraints on the formation and evolution of our solar system. In order to probe the Sedna like population of objects with moderate radii (100 km) we propose a medium wide-field outer solar system survey. This survey will allow us to determine if the objects beyond 50 AU are fainter than expected, if there is truly a dearth of objects, or if the Kuiper Belt continues again after some sizable gap possibly caused by a planet sized object. We will be able to examine the origin of Sedna and determine if this eccentric, distant body is unique (as once believed for Pluto) or just the first of a new class of object in the outer Solar System.

  3. Beyond the Kuiper Belt Edge

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott

    2012-06-01

    Of the thousands of known objects beyond Neptune, only one has a perihelion significantly beyond 50 AU, Sedna at 75 AU. Kuiper Belt surveys to date have not been optimized to survey beyond the Kuiper Belt edge at 50 AU. Most of these surveys either did not go faint enough, did not have the required long cadence to detect very slow moving objects or covered too small of an area of sky. The dynamical and physical properties of objects in this region offer key constraints on the formation and evolution of our solar system. In order to probe the Sedna like population of objects with moderate radii (100 km) we propose a deep wide-field outer solar system survey. This survey will allow us to determine if the objects beyond 50 AU are fainter than expected, if there is truly a dearth of objects, or if the Kuiper Belt continues again after some sizable gap possibly caused by a planet sized object. We will be able to examine the origin of Sedna and determine if this eccentric, distant body is unique (as once believed for Pluto) or just the first of a new class of object in the outer Solar System. We will also explore the Neptune Trojans and scattered disk populations through the survey.

  4. A POSSIBLE DIVOT IN THE SIZE DISTRIBUTION OF THE KUIPER BELT'S SCATTERING OBJECTS

    SciTech Connect

    Shankman, C.; Gladman, B. J.; Kaib, N.; Kavelaars, J. J.; Petit, J. M.

    2013-02-10

    Via joint analysis of a calibrated telescopic survey, which found scattering Kuiper Belt objects, and models of their expected orbital distribution, we explore the scattering-object (SO) size distribution. Although for D > 100 km the number of objects quickly rise as diameters decrease, we find a relative lack of smaller objects, ruling out a single power law at greater than 99% confidence. After studying traditional ''knees'' in the size distribution, we explore other formulations and find that, surprisingly, our analysis is consistent with a very sudden decrease (a divot) in the number distribution as diameters decrease below 100 km, which then rises again as a power law. Motivated by other dynamically hot populations and the Centaurs, we argue for a divot size distribution where the number of smaller objects rises again as expected via collisional equilibrium. Extrapolation yields enough kilometer-scale SOs to supply the nearby Jupiter-family comets. Our interpretation is that this divot feature is a preserved relic of the size distribution made by planetesimal formation, now ''frozen in'' to portions of the Kuiper Belt sharing a ''hot'' orbital inclination distribution, explaining several puzzles in Kuiper Belt science. Additionally, we show that to match today's SO inclination distribution, the supply source that was scattered outward must have already been vertically heated to the of order 10 Degree-Sign .

  5. 49 CFR 179.100-20 - Stamping.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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  6. 20 CFR 411.100 - Scope.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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  7. 20 CFR 638.100 - General.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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  8. 20 CFR 411.100 - Scope.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Introduction § 411.100 Scope. The regulations in this part 411 relate to the provisions of section 1148 of the Social Security Act which establishes the Ticket to Work and Self-Sufficiency Program (hereafter referred to as...

  9. 20 CFR 411.100 - Scope.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Introduction § 411.100 Scope. The regulations in this part 411 relate to the provisions of section 1148 of the Social Security Act which establishes the Ticket to Work and Self-Sufficiency Program (hereafter referred to as...

  10. 20 CFR 411.100 - Scope.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Introduction § 411.100 Scope. The regulations in this part 411 relate to the provisions of section 1148 of the Social Security Act which establishes the Ticket to Work and Self-Sufficiency Program (hereafter referred to as...

  11. The distant Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Gladman, B.; Kavelaars, J. J.; Petit, J. M.; Morbidelli, A.; Holman, M.; Loredo, T.

    2000-10-01

    We present results from a series of deep imaging surveys designed to look for very faint objects in the outer solar system. We find roughly 10-20 percent of our detections outside a heliocentric distance of 48 AU, a much larger fraction than all previously published surveys. The implications of this result for the radial structure of the Kuiper Belt will be discussed, as well as how it interacts with various theories regarding the sculpting of the orbital distribution of the trans-Neptunian region. We find a luminosity function with a continuing steep slope down to the limit of our detections at about 26th magnitude, implying that observations are just on the threshold of reaching the level where the TNO size distribution is exptected to `roll over' to a shallower collisional slope. The size distribution in the observed region is expected to hold information about the time scale and physics of planetesimal building in the early outer Solar System. This work has been supported by a Henri Chretien international research grant (AAS), by NASA Origins grants NAG5-8198 and NAG5-9678, by an ACI Jeune award from the French Research Ministry, and an Observatoire de la Côte d'Azur BQR grant.

  12. 31 CFR 20.100 - What does this part do?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false What does this part do? 20.100 Section 20.100 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Purpose and Coverage § 20.100 What does this...

  13. 31 CFR 20.100 - What does this part do?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false What does this part do? 20.100 Section 20.100 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Purpose and Coverage § 20.100 What does this...

  14. 31 CFR 20.100 - What does this part do?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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  15. 31 CFR 20.100 - What does this part do?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false What does this part do? 20.100 Section 20.100 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Purpose and Coverage § 20.100 What does this...

  16. 31 CFR 20.100 - What does this part do?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false What does this part do? 20.100 Section 20.100 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Purpose and Coverage § 20.100 What does this...

  17. Beyond the Kuiper Belt Edge

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott

    2012-01-01

    Of the thousands of known objects beyond Neptune, only one has a perihelion significantly beyond 50 AU, Sedna at 75 AU. Most Kuiper Belt surveys to date either did not go faint enough, did not have the required long cadence to detect very slow moving objects or covered too small of an area of sky to efficiently detect objects beyond 50 AU. The dynamical and physical properties of objects in this region offer key constraints on the formation and evolution of our solar system. In order to probe the Sedna like population of objects with moderate radii (100 km) we are conducting a deep wide-field outer solar system survey. This survey will allow us to determine if the objects beyond 50 AU are fainter than expected, if there is truly a dearth of objects, or if the Kuiper Belt continues again after some sizable gap possibly caused by a planet sized object. We will be able to examine the origin of Sedna and determine if it is unique (as once believed for Pluto) or one of a new class of object. We request one night in 2012B to recover interesting objects that will be discovered at Subaru in July 2012 and complete the sky coverage needed to constrain the Sedna-like population.

  18. Beyond the Kuiper Belt Edge

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott

    2013-01-01

    Of the thousands of known objects beyond Neptune, only one has a perihelion significantly beyond 50 AU, Sedna at 75 AU. Most Kuiper Belt surveys to date either did not go faint enough, did not have the required long cadence to detect very slow moving objects or covered too small of an area of sky to efficiently detect objects beyond 50 AU. The dynamical and physical properties of objects in this region offer key constraints on the formation and evolution of our solar system. In order to probe the Sedna like population of objects with moderate radii (100 km) we are conducting a deep wide-field outer solar system survey. This survey will allow us to determine if the objects beyond 50 AU are fainter than expected, if there is truly a dearth of objects, or if the Kuiper Belt continues again after some sizable gap possibly caused by a planet sized object. We will be able to examine the origin of Sedna and determine if it is unique (as once believed for Pluto) or one of a new class of object. We request one night in 2013B to recover a very interesting object that we discovered at Subaru in July 2012 and complete the sky coverage needed to constrain the Sedna-like population. This one night was awarded to us in 2012B but lost because of instrument problems.

  19. Kuiper Belt Mapping Radar

    NASA Technical Reports Server (NTRS)

    Freeman, A.; Nilsen, E.

    2001-01-01

    Since their initial discovery in 1992, to date only a relatively small number of Kuiper Belt Objects (KBO's) have been discovered. Current detection techniques rely on frame-to-frame comparisons of images collected by optical telescopes such as Hubble, to detect KBO's as they move against the background stellar field. Another technique involving studies of KBO's through occultation of known stars has been proposed. Such techniques are serendipitous, not systematic, and may lead to an inadequate understanding of the size, range, and distribution of KBO's. In this paper, a future Kuiper Belt Mapping Radar is proposed as a solution to the problem of mapping the size distribution, extent, and range of KBO's. This approach can also be used to recover radar albedo and object rotation rates. Additional information is contained in the original extended abstract.

  20. Infrared Kuiper Belt Constraints

    SciTech Connect

    Teplitz, V.L.; Stern, S.A.; Anderson, J.D.; Rosenbaum, D.; Scalise, R.J.; Wentzler, P.

    1999-05-01

    We compute the temperature and IR signal of particles of radius {ital a} and albedo {alpha} at heliocentric distance {ital R}, taking into account the emissivity effect, and give an interpolating formula for the result. We compare with analyses of {ital COBE} DIRBE data by others (including recent detection of the cosmic IR background) for various values of heliocentric distance {ital R}, particle radius {ital a}, and particle albedo {alpha}. We then apply these results to a recently developed picture of the Kuiper belt as a two-sector disk with a nearby, low-density sector (40{lt}R{lt}50{endash}90 AU) and a more distant sector with a higher density. We consider the case in which passage through a molecular cloud essentially cleans the solar system of dust. We apply a simple model of dust production by comet collisions and removal by the Poynting-Robertson effect to find limits on total and dust masses in the near and far sectors as a function of time since such a passage. Finally, we compare Kuiper belt IR spectra for various parameter values. Results of this work include: (1) numerical limits on Kuiper belt dust as a function of ({ital R}, {ital a}, {alpha}) on the basis of four alternative sets of constraints, including those following from recent discovery of the cosmic IR background by Hauser et al.; (2) application to the two-sector Kuiper belt model, finding mass limits and spectrum shape for different values of relevant parameters including dependence on time elapsed since last passage through a molecular cloud cleared the outer solar system of dust; and (3) potential use of spectral information to determine time since last passage of the Sun through a giant molecular cloud. {copyright} {ital {copyright} 1999.} {ital The American Astronomical Society}

  1. 20. Historic south and west elevation drawing of Building 100. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Historic south and west elevation drawing of Building 100. June 29, 1955. NASA GRC drawing number CE-101443. (On file at NASA Glenn Research Center). - Rocket Engine Testing Facility, GRC Building No. 100, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

  2. 20 CFR 641.100 - What does this part cover?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... GOVERNING THE SENIOR COMMUNITY SERVICE EMPLOYMENT PROGRAM Purpose and Definitions § 641.100 What does this part cover? Part 641 contains the Department of Labor's regulations for the Senior Community Service... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false What does this part cover? 641.100...

  3. 20 CFR 641.100 - What does this part cover?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... GOVERNING THE SENIOR COMMUNITY SERVICE EMPLOYMENT PROGRAM Purpose and Definitions § 641.100 What does this part cover? Part 641 contains the Department of Labor's regulations for the Senior Community Service... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false What does this part cover? 641.100...

  4. Mercury: The Kuiper Melt

    NASA Image and Video Library

    2017-09-27

    Date acquired: April 05, 2013 This striking image of Kuiper shows the crater in a new perspective. This image highlights the crater's smooth impact melt and central peaks. Kuiper, first seen by Mariner 10, is an easily identifiable feature on Mercury's surface due to its bright rays, similar to Hokusai. This image was acquired as a high-resolution targeted observation. Targeted observations are images of a small area on Mercury's surface at resolutions much higher than the 200-meter/pixel morphology base map. It is not possible to cover all of Mercury's surface at this high resolution, but typically several areas of high scientific interest are imaged in this mode each week. The MESSENGER spacecraft is the first ever to orbit the planet Mercury, and the spacecraft's seven scientific instruments and radio science investigation are unraveling the history and evolution of the Solar System's innermost planet. During the first two years of orbital operations, MESSENGER acquired over 150,000 images and extensive other data sets. MESSENGER is capable of continuing orbital operations until early 2015. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

  5. 20 CFR 664.100 - What is the youth council?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... policy and to assist the Local Board in: (1) Developing and recommending local youth employment and training policy and practice; (2) Broadening the youth employment and training focus in the community to... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What is the youth council? 664.100 Section...

  6. Kuipers in the Node 1

    NASA Image and Video Library

    2012-02-03

    ISS030-E-117506 (3 Feb. 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, is pictured near fruit floating freely in the Unity node of the International Space Station.

  7. Kuipers in the Node 1

    NASA Image and Video Library

    2012-02-02

    ISS030-E-116840 (2 Feb. 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, is pictured near fruit floating freely in the Unity node of the International Space Station.

  8. Kuipers exercises on the ARED

    NASA Image and Video Library

    2012-06-05

    ISS031-E-157839 (5 June 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 31 flight engineer, exercises using the advanced Resistive Exercise Device (aRED) in the Tranquility node of the International Space Station.

  9. The Square Kilometer Array

    NASA Astrophysics Data System (ADS)

    Cordes, James M.

    2006-06-01

    The SKA is an observatory for m/cm wavelengths that will provide quantum leaps in studies of the early universe, the high-energy universe, and astrobiology. Key science areas include:(1) Galaxy Evolution and Large-Scale Structure, including Dark Energy;(2) Probing the Dark Ages through studies of highly redshifted hydrogen and carbon monoxide;(3) Cosmic magnetism;(4) Probing Gravity with Pulsars and Black Holes; and(5) The Cradle of Life, including real-time images of protoplanetary disks, inventory of organic molecules, and the search for signals from extraterrestrial intelligence.From a phase-space point of view, the SKA will expand enormously our ability to discover new and known phenomena, including transient sources with time scales from nano-seconds to years. Particular examples include coherent emissions from extrasolar planets and gamma-ray burst afterglows, detectable at levels 100 times smaller than currently. Specifications needed to meet the science requirements are technically quite challenging: a frequency range of approximately 0.1 to 25 GHz; wide field of view, tens of square degrees (frequency dependent); high dynamic range and image fidelity; flexibility in imaging on scales from sub-mas to degrees; and sampling the time-frequency domain as demanded by transient objects. Meeting these specifications requires collaboration of a world-wide group of engineers and scientists. For this and other reasons, the SKA will be realized internationally. Initially, several concepts have been explored for building inexpensive collecting area that provides broad frequency coverage. The Reference Design now specifies an SKA based on a large number of small-diameter dish antennas with "smart feeds." Complementary to the dishes is a phased aperture array that will provide very wide-field capability. I will discuss the Reference Design, along with a timeline for developing the technology, building the first 10% of the SKA, and finishing the full SKA, along with the

  10. The extreme Kuiper Belt binary 2001 QW322.

    PubMed

    Petit, J-M; Kavelaars, J J; Gladman, B J; Margot, J L; Nicholson, P D; Jones, R L; Parker, J Wm; Ashby, M L N; Bagatin, A Campo; Benavidez, P; Coffey, J; Rousselot, P; Mousis, O; Taylor, P A

    2008-10-17

    The study of binary Kuiper Belt objects helps to probe the dynamic conditions present during planet formation in the solar system. We report on the mutual-orbit determination of 2001 QW322, a Kuiper Belt binary with a very large separation whose properties challenge binary-formation and -evolution theories. Six years of tracking indicate that the binary's mutual-orbit period is approximately 25 to 30 years, that the orbit pole is retrograde and inclined 50 degrees to 62 degrees from the ecliptic plane, and, most surprisingly, that the mutual orbital eccentricity is <0.4. The semimajor axis of 105,000 to 135,000 kilometers is 10 times that of other near-equal-mass binaries. Because this weakly bound binary is prone to orbital disruption by interlopers, its lifetime in its present state is probably less than 1 billion years.

  11. Making the cold Kuiper belt in a planetary instability migration model

    NASA Astrophysics Data System (ADS)

    Gomes, Rodney S.

    2017-06-01

    Numerical integrations of the equations of motion of Jupiter, Saturn, three ice cores and a disk of planetesimals are undertaken. Two of the ice planets stand for Uranus and Neptune and a third one is expected to be ejected from the solar system. The planets start in compact cold orbits and each one is in mean motion resonance with its neighbor(s). The disk of planetesimals is placed just outside the outermost planet and is extended to 45 au. Five hundred integrations are done for each of four masses assigned to the disk, which are 25, 30, 35 and 40 Earth masses. The integrations are extended to 100 My. After that, I choose the successful runs in which there are four planets left in closed orbits around the Sun and I separate the good runs among the successful ones, defined by semi-major axes ranges around and not too far from the real ones. Among these good runs, I further choose by visual inspection those that yield an orbital distribution of planetesimals at the Kuiper belt region that resembles the real cold Kuiper belt. I extend these runs to 1 Gy and, after that, to 4.5 Gy. These last integrations for 3.5 Gy are done after replacing the orbits of the planets in the end of the 1 Gy integrations by their current orbits, changing the semi-major axes of the planetesimals so as to keep the same mean motion ratio with Neptune and assigning null masses for the planetesimals. Orbital distributions of the cold Kuiper belt obtained in some of the runs at 4.5 Gy are quite similar to that of the real cold Kuiper belt. The mass in the Kuiper belt region can be dynamically eroded to up to 90% of the original mass. The main conclusion is that the cold Kuiper belt is compatible with a past planetary instability phase even though in some of these runs Neptune's semi-major axis and eccentricity attained values simultaneously larger than 20 au and 0.2 for over 1 My.

  12. Exploration of the Kuiper Belt by serendipitous occultations using Ultraphot and MeFos instruments

    NASA Astrophysics Data System (ADS)

    Roques, F.; Guinouard, I.; Doressoundiram, A.; Felenbok, P.; Boissel, Y.; Sicardy, B.

    2008-09-01

    operated on VLT/UT2, and would have access to the entire field of the Nasmyth focus (25' diameter). The number of fibers of UltraPhot will be determined as a compromise between the camera read-out frequency and the capacity of the positioning system. Our estimates are based on a total of 100 to 200 fibers for a read-out frequency of 100 Hz using a 2 color photometry mode. The expected S/N ratio could be at least 10 3 /√f, where f is the read-out frequency for a magnitude 13. Potential interested scientific fields are numerous : Exploration of Outer Solar System Objects by stellar occultations : The aim is to characterize the small end of size distribution and the outer part of the Solar System population by a collection of serendipitous events. A challenge is the possibility to explore the Oort Cloud (using this method, we estimate a 5-kilometer comet-like object can be positively detected at a distance of 10000 AU). Extrasolar Planets Transits : Ultraphot will allow follow up of the Corot/Kepler targets. High precision photometry associated with a large field of view (1/20 of the Corot Exoplanets FOV) makes Ultraphot a powerful tool to explore the transit exoplanetary systems and to detect small planets. Moreover, precise timing of transits give access to other planets in the system by their perturbations on the orbits parameters. Study of variable objects in Globular Clusters (GC) would also benefit from this instrument. Searching for rapid periodic variations of blue objects might help to identify their nature. In particular Compact Binaries (CB) including Cataclysmic Variables are predicted to be numerous in GC not only in the cores but also in their outskirts. References [1] Roques, F. et Moncuquet M. (2000) A Detection Method for the Small Kuiper Belt Objects: The Stellar Occultations. Icarus, 147, 530-544. [2] F. Roques , A. Doressoundiram et al. (2006) Small and Distant Kuiper Belt Objects revealed by Stellar occultations, AJ, 132, 819 [3] Georgevits G. (2006

  13. Kuipers performs Water Sample Analysis

    NASA Image and Video Library

    2012-05-15

    ISS031-E-084619 (15 May 2012) --- After collecting samples from the Water Recovery System (WRS), European Space Agency astronaut Andre Kuipers, Expedition 31 flight engineer, processes the samples for chemical and microbial analysis in the Unity node of the International Space Station.

  14. WATER ICE IN THE KUIPER BELT

    SciTech Connect

    Brown, M. E.; Fraser, W. C.; Schaller, E. L.

    2012-06-15

    We examine a large collection of low-resolution near-infrared spectra of Kuiper Belt objects (KBOs) and centaurs in an attempt to understand the presence of water ice in the Kuiper Belt. We find that water ice on the surface of these objects occurs in three separate manners: (1) Haumea family members uniquely show surfaces of nearly pure water ice, presumably a consequence of the fragmentation of the icy mantle of a larger differentiated proto-Haumea; (2) large objects with absolute magnitudes of H < 3 (and a limited number to H = 4.5) have surface coverings of water ice-perhaps mixed with ammonia-that appears to be related to possibly ancient cryovolcanism on these large objects; and (3) smaller KBOs and centaurs which are neither Haumea family members nor cold-classical KBOs appear to divide into two families (which we refer to as 'neutral' and 'red'), each of which is a mixture of a common nearly neutral component and either a slightly red or very red component that also includes water ice. A model suggesting that the difference between neutral and red objects due to formation in an early compact solar system either inside or outside, respectively, of the {approx}20 AU methanol evaporation line is supported by the observation that methanol is only detected on the reddest objects, which are those which would be expected to have the most of the methanol containing mixture.

  15. 20 CFR 438.100 - Conditions on use of funds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 438.100 Employees' Benefits SOCIAL SECURITY ADMINISTRATION RESTRICTIONS ON LOBBYING General § 438.100..., grant, loan, or cooperative agreement to pay any person for influencing or attempting to influence an... payment to influence or attempt to influence an officer or employee of SSA, a Member of Congress, an...

  16. 20 CFR 438.100 - Conditions on use of funds.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 438.100 Employees' Benefits SOCIAL SECURITY ADMINISTRATION RESTRICTIONS ON LOBBYING General § 438.100..., grant, loan, or cooperative agreement to pay any person for influencing or attempting to influence an... payment to influence or attempt to influence an officer or employee of SSA, a Member of Congress, an...

  17. 20 CFR 438.100 - Conditions on use of funds.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 438.100 Employees' Benefits SOCIAL SECURITY ADMINISTRATION RESTRICTIONS ON LOBBYING General § 438.100..., grant, loan, or cooperative agreement to pay any person for influencing or attempting to influence an... payment to influence or attempt to influence an officer or employee of SSA, a Member of Congress, an...

  18. 20 CFR 438.100 - Conditions on use of funds.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 438.100 Employees' Benefits SOCIAL SECURITY ADMINISTRATION RESTRICTIONS ON LOBBYING General § 438.100..., grant, loan, or cooperative agreement to pay any person for influencing or attempting to influence an... payment to influence or attempt to influence an officer or employee of SSA, a Member of Congress, an...

  19. 20 CFR 438.100 - Conditions on use of funds.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 438.100 Employees' Benefits SOCIAL SECURITY ADMINISTRATION RESTRICTIONS ON LOBBYING General § 438.100..., grant, loan, or cooperative agreement to pay any person for influencing or attempting to influence an... payment to influence or attempt to influence an officer or employee of SSA, a Member of Congress, an...

  20. The binary Kuiper-belt object 1998 WW31.

    PubMed

    Veillet, Christian; Parker, Joel Wm; Griffin, Ian; Marsden, Brian; Doressoundiram, Alain; Buie, Marc; Tholen, David J; Connelley, Michael; Holman, Matthew J

    2002-04-18

    The recent discovery of a binary asteroid during a spacecraft fly-by generated keen interest, because the orbital parameters of binaries can provide measures of the masses, and mutual eclipses could allow us to determine individual sizes and bulk densities. Several binary near-Earth, main-belt and Trojan asteroids have subsequently been discovered. The Kuiper belt-the region of space extending from Neptune (at 30 astronomical units) to well over 100 AU and believed to be the source of new short-period comets-has become a fascinating new window onto the formation of our Solar System since the first member object, not counting Pluto, was discovered in 1992 (ref. 13). Here we report that the Kuiper-belt object 1998 WW31 is binary with a highly eccentric orbit (eccentricity e approximately 0.8) and a long period (about 570 days), very different from the Pluto/Charon system, which was hitherto the only previously known binary in the Kuiper belt. Assuming a density in the range of 1 to 2 g cm-3, the albedo of the binary components is between 0.05 and 0.08, close to the value of 0.04 generally assumed for Kuiper-belt objects.

  1. Distribution of Dust from Kuiper Belt Objects

    NASA Technical Reports Server (NTRS)

    Gorkavyi, Nick N.; Ozernoy, Leonid; Taidakova, Tanya; Mather, John C.; Fisher, Richard (Technical Monitor)

    2000-01-01

    Using an efficient computational approach, we have reconstructed the structure of the dust cloud in the Solar system between 0.5 and 100 AU produced by the Kuiper belt objects. Our simulations offer a 3-D physical model of the 'kuiperoidal' dust cloud based on the distribution of 280 dust particle trajectories produced by 100 known Kuiper belt objects; the resulting 3-D grid consists of 1.9 x 10' cells containing 1.2 x 10" particle positions. The following processes that influence the dust particle dynamics are taken into account: 1) gravitational scattering on the eight planets (neglecting Pluto); 2) planetary resonances; 3) radiation pressure; and 4) the Poynting-Robertson (P-R) and solar wind drags. We find the dust distribution highly non-uniform: there is a minimum in the kuiperoidal dust between Mars and Jupiter, after which both the column and number densities of kuiperoidal dust sharply increase with heliocentric distance between 5 and 10 AU, and then form a plateau between 10 and 50 AU. Between 25 and 45 AU, there is an appreciable concentration of kuiperoidal dust in the form of a broad belt of mostly resonant particles associated with Neptune. In fact, each giant planet possesses its own circumsolar dust belt consisting of both resonant and gravitationally scattered particles. As with the cometary belts simulated in our related papers, we reveal a rich and sophisticated resonant structure of the dust belts containing families of resonant peaks and gaps. An important result is that both the column and number dust density are more or less flat between 10 and 50 AU, which might explain the surprising data obtained by Pioneers 10 & 11 and Voyager that the dust number density remains approximately distance-independent in this region. The simulated kuiperoidal dust, in addition to asteroidal and cometary dust, might represent a third possible source of the zodiacal light in the Solar system.

  2. 20 CFR 1001.100 - Purpose and scope of subpart.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... TRAINING SERVICE, DEPARTMENT OF LABOR SERVICES FOR VETERANS Purpose and Definitions § 1001.100 Purpose and... the needs of disabled veterans and veterans of the Vietnam era, through the public employment service... staff of the Veterans' Employment and Training Service (VETS). (c) This subpart describes...

  3. 20 CFR 645.100 - What does this part cover?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... GOVERNING WELFARE-TO-WORK GRANTS Scope and Purpose § 645.100 What does this part cover? (a) Subpart A establishes regulatory provisions that apply to the Welfare-to-Work (WtW) programs conducted at the State and... matching requirements and reallotment procedures. (d) Subpart D sets forth the conditions under which...

  4. 20 CFR 641.100 - What does this part cover?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... GOVERNING THE SENIOR COMMUNITY SERVICE EMPLOYMENT PROGRAM Purpose and Definitions § 641.100 What does this part cover? Part 641 contains the Department of Labor's regulations for the Senior Community Service... efforts to provide services through the integration of the SCSEP within the One-Stop Delivery System. (c...

  5. 20 CFR 664.100 - What is the youth council?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... expertise in youth policy and to assist the Local Board in: (1) Developing and recommending local youth employment and training policy and practice; (2) Broadening the youth employment and training focus in the... 664.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR...

  6. 20 CFR 664.100 - What is the youth council?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... expertise in youth policy and to assist the Local Board in: (1) Developing and recommending local youth employment and training policy and practice; (2) Broadening the youth employment and training focus in the... 664.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR...

  7. 20 CFR 664.100 - What is the youth council?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... expertise in youth policy and to assist the Local Board in: (1) Developing and recommending local youth employment and training policy and practice; (2) Broadening the youth employment and training focus in the... 664.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR...

  8. 20 CFR 664.100 - What is the youth council?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... policy and to assist the Local Board in: (1) Developing and recommending local youth employment and training policy and practice; (2) Broadening the youth employment and training focus in the community to... 664.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR...

  9. 20 CFR 637.100 - Scope and purpose.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR PROGRAMS UNDER TITLE V OF THE JOB TRAINING PARTNERSHIP ACT General Provisions § 637.100 Scope and purpose. (a) This part... certain employable dependent individuals with job training to reduce welfare dependency, to promote self...

  10. 20 CFR 637.100 - Scope and purpose.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR PROGRAMS UNDER TITLE V OF THE JOB TRAINING PARTNERSHIP ACT General Provisions § 637.100 Scope and purpose. (a) This part... certain employable dependent individuals with job training to reduce welfare dependency, to promote self...

  11. 20 CFR 637.100 - Scope and purpose.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR PROGRAMS UNDER TITLE V OF THE JOB TRAINING PARTNERSHIP ACT General Provisions § 637.100 Scope and purpose. (a) This part... certain employable dependent individuals with job training to reduce welfare dependency, to promote self...

  12. THE COLLISIONAL DIVOT IN THE KUIPER BELT SIZE DISTRIBUTION

    SciTech Connect

    Fraser, Wesley C.

    2009-11-20

    This paper presents the results of collisional evolution calculations for the Kuiper Belt starting from an initial size distribution similar to that produced by accretion simulations of that region-a steep power-law large object size distribution that breaks to a shallower slope at r approx 1-2 km, with collisional equilibrium achieved for objects r approx< 0.5 km. We find that the break from the steep large object power law causes a divot, or depletion of objects at r approx 10-20 km, which, in turn, greatly reduces the disruption rate of objects with r approx> 25-50 km, preserving the steep power-law behavior for objects at this size. Our calculations demonstrate that the roll-over observed in the Kuiper Belt size distribution is naturally explained as an edge of a divot in the size distribution; the radius at which the size distribution transitions away from the power law, and the shape of the divot from our simulations are consistent with the size of the observed roll-over, and size distribution for smaller bodies. Both the kink radius and the radius of the divot center depend on the strength scaling law in the gravity regime for Kuiper Belt objects. These simulations suggest that the sky density of r approx 1 km objects is approx10{sup 6}-10{sup 7} objects per square degree. A detection of the divot in the size distribution would provide a measure of the strength of large Kuiper Belt objects, and constrain the shape of the size distribution at the end of accretion in the Kuiper Belt.

  13. [The 20th century: 100 years of misfortune and splendor].

    PubMed

    Urdaneta-Carruyo, Eliéxer

    2005-01-01

    The 20th century has been one of the most intense and convulsive periods in the History of humanity. A century of paradoxes and contrasts, it began with optimism, it witnessed the apocalypse of two world wars, and finished with unimaginable scientific progress that gave us a new civilization that we cannot yet grasp. In this century, significant events happened that shaped our time and projected their results toward an immediate future. Some of these were providential in understanding man's life, fighting against illnesses and prolonging life, and others were of undeniable social importance for humanity. Some knowledge was based on the work of others. Philosophy was embedded in mathematics, as was science in philosophy, while politics and the economy exercised so decisive an influence in our way of feeling and living that culture and society were affected to the core. Within that century the biggest technological revolution of all the time was also created, as transcendent as it was unimaginable, which put mankind on the road to the stars with the moon landing and in the process created the information society whose signature symbol, the internet, emerged as a new demiurge. However, the 20th century, with all its misfortune and splendor, paradoxes and contrasts, creation and destruction, was the most transcendent in the whole of history and it bequeaths to the future a promising horizon in the search for a renovated meaning of life and a yearning for peaceful coexistence for the whole humanity.

  14. 28 CFR 100.20 - Confidentiality of trade secrets/proprietary information.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Confidentiality of trade secrets/proprietary information. 100.20 Section 100.20 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) COST RECOVERY REGULATIONS, COMMUNICATIONS ASSISTANCE FOR LAW ENFORCEMENT ACT OF 1994 § 100.20 Confidentiality of...

  15. 28 CFR 100.20 - Confidentiality of trade secrets/proprietary information.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Confidentiality of trade secrets/proprietary information. 100.20 Section 100.20 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) COST RECOVERY REGULATIONS, COMMUNICATIONS ASSISTANCE FOR LAW ENFORCEMENT ACT OF 1994 § 100.20 Confidentiality of...

  16. Gerard Kuiper and the Infrared Detector

    NASA Astrophysics Data System (ADS)

    Sears, Derek

    2013-10-01

    The life and contributions of Gerard Kuiper have been documented by Dale Cruikshank in his National Academy of Sciences biography. I will argue that particularly important in this eventful life was Kuiper's war time experiences. Kuiper's wartime role evolved as the war unfolded, but towards the end he was charged by the US military with reporting German progress with war-related technologies and the activities of scientists under Nazi control. He interviewed a great many scientists, including his own PhD mentor (Ejnar Hertzsprung), and when Kuiper was the only person available, he interviewed concentration-camp victims. He carried briefing sheets that identified the technologies being sought by the allies and the major fraction of these involved infrared equipment. He sent back to the USA boxes of documents, and large amounts of equipment, and he stressed to the military his interest in these for his own research. It seems very likely that in this way an effective PbS infrared detector, so critical to Kuiper's career and the future of planetary science, came to the USA and to Robert Cashman's laboratory at Northwestern University. As the war was winding down, Cashman and Kuiper worked together to develop a practical infrared spectrometer for astronomical use. Within months, Kuiper discovered the C02 atmospheres on Mars and Venus.

  17. A Search for 23rd Magnitude Kuiper Belt Comets

    NASA Technical Reports Server (NTRS)

    Luu, Jane

    1997-01-01

    The goal of the project was to identify a statistically significant sample of large (200 km-sized) Kuiper Belt Objects (KBOs), by covering 10 sq. degrees of the sky to a red limiting magnitude m(sub R) = 23. This work differs from, but builds on, previous surveys of the outer solar system in that it will cover a large area to a limiting magnitude that is deep enough to guarantee positive results. The proposed work should provide us with a significant number of 200 km-size KBOs (approx. 20 are expected) for subsequent studies. Such a sample is crucial if we are to investigate the statistical properties of the Belt and its members. It was modified the original research strategy to accommodate unanticipated problems such as the urgent need for follow-up observations,the original goal was still reached: we have substantially increased the number of Kuiper Belt Objects brighter than 23rd mag.

  18. Water Ice on Kuiper Belt Object 1996 TO66

    NASA Technical Reports Server (NTRS)

    Brown, R. H.; Cruikshank, D. P.; Pendleton, Y.

    1999-01-01

    The 1.40-2.40 micron spectrum of Kuiper Belt object (KBO) 1996 TO66 was measured at the Keck Observatory in September 1998. It's spectrum shows the strong absorptions near 1.5 and 2.0 micron characteristic of water ice--the first such detection on a Kuiper Belt object. The depth of the absorption bands and the continuum reflectance of 1996 TO66 also suggest the presence of a black to slightly blue-colored, spectrally featureless particulate material as a minority component mixed with the water ice. In addition, there is evidence that the intensity of the water bands in the spectrum of 1996 TO66 vary with rotational phase suggesting that it has a "patchy" surface.

  19. Structure of the atmosphere of Venus up to 110 kilometers: Preliminary results from the four Pioneer Venus entry probes

    USGS Publications Warehouse

    Seiff, A.; Kirk, D.B.; Sommer, S.C.; Young, R.E.; Blanchard, R.C.; Juergens, D.W.; Lepetich, J.E.; Intrieri, P.F.; Findlay, J.T.; Derr, J.S.

    1979-01-01

    The four Pioneer Venus entry probes transmitted data of good quality on the structure of the atmosphere below the clouds. Contrast of the structure below an altitude of 50 kilometers at four widely separated locations was found to be no more than a few degrees Kelvin, with slightly warmer temperatures at 30?? south latitude than at 5?? or 60?? north. The atmosphere was stably stratified above 15 or 20 kilometers, indicating that the near-adiabatic state is maintained by the general circulation. The profiles move from near-adiabatic toward radiative equilibrium at altitudes above 40 kilometers. There appears to be a region of vertical convection above the dense cloud deck, which lies at 47.5 to 49 kilometers and at temperature levels near 360 K. The atmosphere is nearly isothermal around 100 kilometers (175 to 180 K) and appears to exhibit a sizable temperature wave between 60 and 70 kilometers. This is where the 4-day wind is believed to occur. The temperature wave may be related to some of the wavelike phenomena seen in Mariner 10 ultraviolet photographs. Copyright ?? 1979 AAAS.

  20. Phobos from 6,800 Kilometers (Color)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Inset

    The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took two images of the larger of Mars' two moons, Phobos, within 10 minutes of each other on March 23, 2008. This is the first, taken from a distance of about 6,800 kilometers (about 4,200 miles). It is presented in color by combining data from the camera's blue-green, red, and near-infrared channels.

    The illuminated part of Phobos seen in the images is about 21 kilometers (13 miles) across. The most prominent feature in the images is the large crater Stickney in the lower right. With a diameter of 9 kilometers (5.6 miles), it is the largest feature on Phobos.

    The color data accentuate details not apparent in black-and-white images. For example, materials near the rim of Stickney appear bluer than the rest of Phobos. Based on analogy with materials on our own moon, this could mean this surface is fresher, and therefore younger, than other parts of Phobos.

    A series of troughs and crater chains is obvious on other parts of the moon. Although many appear radial to Stickney in this image, recent studies from the European Space Agency's Mars Express orbiter indicate that they are not related to Stickney. Instead, they may have formed when material ejected from impacts on Mars later collided with Phobos. The lineated textures on the walls of Stickney and other large craters are landslides formed from materials falling into the crater interiors in the weak Phobos gravity (less than one one-thousandth of the gravity on Earth).

    In the full-resolution version of this image, a pixel encompasses 6.8 meters (22 feet), providing a resolution (smallest visible feature) of about 20 meters (about 65 feet). The image is in the HiRISE catalog as PSP_007769_9010.

    NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance

  1. Phobos from 6,800 Kilometers

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took two images of the larger of Mars' two moons, Phobos, within 10 minutes of each other on March 23, 2008. This is the first, taken from a distance of about 6,800 kilometers (about 4,200 miles). The illuminated part of Phobos seen in the images is about 21 kilometers (13 miles) across.

    The most prominent feature in the images is the large crater Stickney in the lower right. With a diameter of 9 kilometers (5.6 miles), it is the largest feature on Phobos. A series of troughs and crater chains is obvious on other parts of the moon. Although many appear radial to Stickney in this image, recent studies from the European Space Agency's Mars Express orbiter indicate that they are not related to Stickney. Instead, they may have formed when material ejected from impacts on Mars later collided with Phobos. The lineated textures on the walls of Stickney and other large craters are landslides formed from materials falling into the crater interiors in the weak Phobos gravity (less than one one-thousandth of the gravity on Earth).

    In the full-resolution version of this image, a pixel encompasses 6.8 meters (22 feet), providing a resolution (smallest visible feature) of about 20 meters (about 65 feet). Although the image is displayed here in black and white, data from HiRISE's three color channels were used to give higher signal-to-noise, thereby increasing detail. The image is in the HiRISE catalog as PSP_007769_9010.

    NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace

  2. Kuipers during Glovebox Health Check in Columbus

    NASA Image and Video Library

    2012-05-18

    ISS031-E-140316 (18 May 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 31 flight engineer, supports a ground-conducted health check on ESA’s Biolab Glovebox in the Columbus laboratory of the International Space Station.

  3. Kuipers during Glovebox Health Check in Columbus

    NASA Image and Video Library

    2012-05-18

    ISS031-E-140311 (18 May 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 31 flight engineer, supports a ground-conducted health check on ESA’s Biolab Glovebox in the Columbus laboratory of the International Space Station.

  4. Kuipers during Glovebox Health Check in Columbus

    NASA Image and Video Library

    2012-05-18

    ISS031-E-140314 (18 May 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 31 flight engineer, supports a ground-conducted health check on ESA’s Biolab Glovebox in the Columbus laboratory of the International Space Station.

  5. Kuipers works in the ATV-3

    NASA Image and Video Library

    2012-04-06

    ISS030-E-210896 (6 April 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, works in the Automated Transfer Vehicle (ATV-3) currently docked with the International Space Station.

  6. Kuipers floats through the ATV-3

    NASA Image and Video Library

    2012-04-06

    ISS030-E-210842 (6 April 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, floats into the Automated Transfer Vehicle (ATV-3) currently docked with the International Space Station.

  7. Kuipers near food containers in the SM

    NASA Image and Video Library

    2012-03-28

    ISS030-E-178069 (28 March 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, is pictured near food storage containers in the Zvezda Service Module of the International Space Station.

  8. Kuipers performs Potable Water Sample Collection

    NASA Image and Video Library

    2012-05-15

    ISS031-E-079015 (15 May 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 31 flight engineer, collects a sample from the Water Recovery System (WRS) in the Destiny laboratory of the International Space Station.

  9. Kuipers performs Potable Water Sample Collection

    NASA Image and Video Library

    2012-05-15

    ISS031-E-157783 (15 May 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 31 flight engineer, collects a water sample from the Potable Water Dispenser (PWD) in the Destiny laboratory of the International Space Station.

  10. Three steps toward understanding the dynamical structure of the Kuiper belt (and what it means for Neptune's migration)

    NASA Astrophysics Data System (ADS)

    Nesvorny, David

    2015-11-01

    Much of the dynamical structure of the Kuiper belt can be explained if Neptune migrated over several AU, and/or if Neptune was scattered to an eccentric orbit during planetary instability.Step 1: An outstanding problem with the previous migration/instability models is that the distribution of orbital inclinations they predict is narrower than the one inferred from observations. Here we perform numerical simulations of the Kuiper belt formation starting from an initial state with Neptune at 20100 Myr. A small fraction of the disk planetesimals become implanted into the Kuiper belt in the simulations. We find that the inclination constraint implies that Neptune's migration was slow (tau > 10 Myr) and long range (a_N < 25 AU).Step 2: A particularly puzzling and up-to-now unexplained feature of the Kuiper belt is the so-called `kernel', a concentration of orbits with semimajor axes a=44 AU, eccentricities e=0.05, and inclinations i<5 deg. Here we show that the Kuiper belt kernel can be explained if Neptune's migration was interrupted by a discontinuous change of Neptune's semimajor axis when Neptune reached 28 AU (jumping-Neptune model).Step 3: The existing migration/instability models invariably predict an excessively large resonant population, while observations show that the non-resonant orbits are in fact more common (e.g., Plutinos in the 3:2 resonance represent only ~1/3 of the main belt population). Here we show that the observed population statistic implies that Neptune's migration was grainy, as expected from scattering encounters of Neptune with massive planetesimals. Our preferred fit to observations suggests that the outer planetesimal disk below 30 AU contained ~2000 bodies with mass comparable to that of Pluto.Together, these results imply that Neptune's migration was slow, long-range and grainy

  11. OORT-Cloud and Kuiper-Belt Comets

    NASA Technical Reports Server (NTRS)

    Whipple, Fred L.

    1998-01-01

    This paper follows the broadly accepted theory that Oort-Cloud Comets originated in the Solar Nebula in the general region where the major planets, Jupiter and Saturn, were formed while the Kuiper-Belt Comets originated farther out where the temperatures were lower. The Oort-Cloud Comets are identified orbitally by long periods and random inclinations and, including the Halley-type comets, comets with a Tisserand Criterion less than 2.0. Kuiper-Belt comets are identified by short periods, usually much less than 200 years, and small inclinations to the ecliptic. Here two criteria for comet activity are found to separate the two classes of comets. These quantities NG1 and NG2, were intended to measure theoretical nongravitaional effects on comet orbits. They are only, mildly successful in correlations with observed cases of measured non-gravitational forces. But, in fact, their variations with perihelion distance separate the two classes of comets. The results are consistent with the theory that the activity or intrinsic brightness of Oort-Cloud Comets fall off faster with increasing perihelion distance that does the intrinsic brightness of short-period Kuiper-Belt Comets.

  12. Satellite-based entanglement distribution over 1200 kilometers.

    PubMed

    Yin, Juan; Cao, Yuan; Li, Yu-Huai; Liao, Sheng-Kai; Zhang, Liang; Ren, Ji-Gang; Cai, Wen-Qi; Liu, Wei-Yue; Li, Bo; Dai, Hui; Li, Guang-Bing; Lu, Qi-Ming; Gong, Yun-Hong; Xu, Yu; Li, Shuang-Lin; Li, Feng-Zhi; Yin, Ya-Yun; Jiang, Zi-Qing; Li, Ming; Jia, Jian-Jun; Ren, Ge; He, Dong; Zhou, Yi-Lin; Zhang, Xiao-Xiang; Wang, Na; Chang, Xiang; Zhu, Zhen-Cai; Liu, Nai-Le; Chen, Yu-Ao; Lu, Chao-Yang; Shu, Rong; Peng, Cheng-Zhi; Wang, Jian-Yu; Pan, Jian-Wei

    2017-06-16

    Long-distance entanglement distribution is essential for both foundational tests of quantum physics and scalable quantum networks. Owing to channel loss, however, the previously achieved distance was limited to ~100 kilometers. Here we demonstrate satellite-based distribution of entangled photon pairs to two locations separated by 1203 kilometers on Earth, through two satellite-to-ground downlinks with a summed length varying from 1600 to 2400 kilometers. We observed a survival of two-photon entanglement and a violation of Bell inequality by 2.37 ± 0.09 under strict Einstein locality conditions. The obtained effective link efficiency is orders of magnitude higher than that of the direct bidirectional transmission of the two photons through telecommunication fibers. Copyright © 2017, American Association for the Advancement of Science.

  13. The long-term dynamical behavior of small bodies in the Kuiper belt

    NASA Astrophysics Data System (ADS)

    Levison, Harold F.

    1991-08-01

    The results are presented from a new numerical technique to determine the long-term dynamical behavior of objects in the Kuiper belt. According to this model, it is possible for some objects that formed in a well-defined region of the Kuiper belt to have lifetimes of approximately 5 x 10 to the 9th yr, after which they leave the region between 30 and 100 AU. Therefore, the Kuiper belt can be the source of short-period comets. Objects tend to diffuse through a region 70 AU in extent on timescales that are on the order of the age of the solar system. Objects that form close to the orbit of Neptune have a significant chance of evolving to orbits with a greater than 100 AU. These objects can be effectively stored in these orbits for a very long time.

  14. 28 CFR 100.20 - Confidentiality of trade secrets/proprietary information.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Confidentiality of trade secrets/proprietary information. 100.20 Section 100.20 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) COST... trade secrets/proprietary information. With respect to any information provided to the FBI under...

  15. 28 CFR 100.20 - Confidentiality of trade secrets/proprietary information.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Confidentiality of trade secrets/proprietary information. 100.20 Section 100.20 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) COST... trade secrets/proprietary information. With respect to any information provided to the FBI under...

  16. 28 CFR 100.20 - Confidentiality of trade secrets/proprietary information.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Confidentiality of trade secrets/proprietary information. 100.20 Section 100.20 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) COST... trade secrets/proprietary information. With respect to any information provided to the FBI under...

  17. 10 CFR 100.20 - Factors to be considered when evaluating sites.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Section 100.20 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) REACTOR SITE CRITERIA Evaluation Factors for Stationary Power Reactor Site Applications on or After January 10, 1997 § 100.20 Factors to be... determining the acceptability of a site for a stationary power reactor: (a) Population density and use...

  18. 21 CFR 20.100 - Applicability; cross-reference to other regulations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... additive petitions, in § 71.15 of this chapter. (5) Food standard temporary permits, in § 130.17(k) of this... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Applicability; cross-reference to other regulations. 20.100 Section 20.100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN...

  19. Cdc20 mediates D-box-dependent degradation of Sp100

    SciTech Connect

    Wang, Ran; Li, Ke-min; Zhou, Cai-hong; Xue, Jing-lun; Ji, Chao-neng; Chen, Jin-zhong

    2011-12-02

    Highlights: Black-Right-Pointing-Pointer Cdc20 is a co-activator of APC/C complex. Black-Right-Pointing-Pointer Cdc20 recruits Sp100 and mediates its degradation. Black-Right-Pointing-Pointer The D-box of Sp100 is required for Cdc20-mediated degradation. Black-Right-Pointing-Pointer Sp100 expresses consistently at both the mRNA and protein levels in cell cycle. -- Abstract: Cdc20 is a co-activator of the anaphase-promoting complex/cyclosome (APC/C complex), which recruits substrates at particular phases of the cell cycle and mediates their degradation. Sp100 is a PML-NB scaffold protein, which localizes to nuclear particles during interphase and disperses from them during mitosis, participates in viral resistance, transcriptional regulation, and apoptosis. However, its metabolism during the cell cycle has not yet been fully characterized. We found a putative D-box in Sp100 using the Eukaryotic Linear Motif (ELM) predictor database. The putative D-box of Sp100 was verified by mutational analysis. Overexpression of Cdc20 resulted in decreased levels of both endogenous Sp100 protein and overexpressed Sp100 mRNA in HEK 293 cells. Only an overexpressed D-box deletion mutant of Sp100 accumulated in HEK293 cells that also overexpressed Cdc20. Cdc20 knockdown by cdc20 specific siRNA resulted in increased Sp100 protein levels in cells. Furthermore, we discovered that the Cdc20 mediated degradation of Sp100 is diminished by the proteasome inhibitor MG132, which suggests that the ubiquitination pathway is involved in this process. However, unlike the other Cdc20 substrates, which display oscillating protein levels, the level of Sp100 protein remains constant throughout the cell cycle. Additionally, both overexpression and knockdown of endogenous Sp100 had no effect on the cell cycle. Our results suggested that sp100 is a novel substrate of Cdc20 and it is degraded by the ubiquitination pathway. The intact D-box of Sp100 was necessary for this process. These findings expand

  20. 46 CFR 42.20-8 - Flooding standard: Type “B” vessel, 100 percent reduction.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Flooding standard: Type âBâ vessel, 100 percent reduction. 42.20-8 Section 42.20-8 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES DOMESTIC AND FOREIGN VOYAGES BY SEA Freeboards § 42.20-8 Flooding standard: Type “B” vessel, 100 percent reduction. (a) Design calculations...

  1. Ethynilestradiol 20 mcg plus Levonorgestrel 100 mcg: Clinical Pharmacology

    PubMed Central

    2014-01-01

    Estroprogestins (EPs) are combinations of estrogen and progestin with several actions on women's health. The different pharmacological composition of EPs is responsible for different clinical effects. One of the most used low-dose EP associations is ethinylestradiol 20 mcg plus levonorgestrel 100 mcg in monophasic regimen (EE20/LNG100). This review summarizes clinical pharmacology, cycle control, and effects on lipid and glucose metabolism, coagulation, body weight/body composition, acne, and sexuality of EE20/LNG100. Overall, EE20/LNG100 combination is safe and well tolerated, and in several studies the incidence of adverse events in the treated group was comparable to that of the placebo group. Cycle control was effective and body weight/body composition did not vary among treated and untreated groups in most studies. The EE20/LNG100 combination shows mild or no effect on lipid and glucose metabolism. Lastly, EE20/LNG100 is associated with a low risk of venous thromboembolism (VTE). In conclusion, in the process of decision making for the individualization of EPs choice, EE20/LNG100 should be considered for its favorable clinical profile. PMID:25477960

  2. The state of knowledge concerning the Kuiper belt

    NASA Technical Reports Server (NTRS)

    Levison, Harold F.

    1992-01-01

    The arguments for and against the idea that most short-period comets originate in the Kuiper belt are discussed. Observational constraints on the distribution of mass in the Kuiper belt are reviewed as well as a model of the physical conditions that now exist. Finally, predictions from this model about the detectability of the Kuiper belt are compared to optical surveys.

  3. Precise Astrometry for Predicting Kuiper Belt Object Occultations

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott; Person, Michael; Zuluaga, Carlos; Bosh, Amanda

    2011-08-01

    Occultations by Kuiper Belt objects remain elusive events, requiring precision astrometry for these faint bodies in the outer solar system. Monthly astrometry provides data that are crucial for our KBO ephemeris correction models, which then allow accurate shadow track predictions. Through the occultation events the diameters, possible companions and tenuous atmospheres around these objects will be explored by examining how the light from the star varies as the KBO passes in front of it. This promises to be a powerful way of exploring the KBOs. We propose to obtain very precise astrometry on 20 of the brightest known KBOs to determine more accurate orbits and thus reliable occultation predictions.

  4. UNBIASED INCLINATION DISTRIBUTIONS FOR OBJECTS IN THE KUIPER BELT

    SciTech Connect

    Gulbis, A. A. S.; Elliot, J. L.; Adams, E. R.; Benecchi, S. D.; Buie, M. W.; Trilling, D. E.; Wasserman, L. H. E-mail: jle@mit.ed E-mail: lhw@lowell.ed E-mail: buie@boulder.swri.ed

    2010-08-15

    Using data from the Deep Ecliptic Survey (DES), we investigate the inclination distributions of objects in the Kuiper Belt. We present a derivation for observational bias removal and use this procedure to generate unbiased inclination distributions for Kuiper Belt objects (KBOs) of different DES dynamical classes, with respect to the Kuiper Belt plane. Consistent with previous results, we find that the inclination distribution for all DES KBOs is well fit by the sum of two Gaussians, or a Gaussian plus a generalized Lorentzian, multiplied by sin i. Approximately 80% of KBOs are in the high-inclination grouping. We find that Classical object inclinations are well fit by sin i multiplied by the sum of two Gaussians, with roughly even distribution between Gaussians of widths 2.0{sup +0.6}{sub -0.5}{sup 0} and 8.1{sup +2.6}{sub -2.1}{sup 0}. Objects in different resonances exhibit different inclination distributions. The inclinations of Scattered objects are best matched by sin i multiplied by a single Gaussian that is centered at 19.1{sup +3.9}{sub -3.6}{sup 0} with a width of 6.9{sup +4.1}{sub -2.7}{sup 0}. Centaur inclinations peak just below 20{sup 0}, with one exceptionally high-inclination object near 80{sup 0}. The currently observed inclination distribution of the Centaurs is not dissimilar to that of the Scattered Extended KBOs and Jupiter-family comets, but is significantly different from the Classical and Resonant KBOs. While the sample sizes of some dynamical classes are still small, these results should begin to serve as a critical diagnostic for models of solar system evolution.

  5. 20 CFR 10.0 - What are the provisions of the FECA, in general?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true What are the provisions of the FECA, in general? 10.0 Section 10.0 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF... the payment of workers' compensation benefits to civilian officers and employees of all branches of...

  6. 20 CFR 10.0 - What are the provisions of the FECA, in general?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false What are the provisions of the FECA, in general? 10.0 Section 10.0 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF... the payment of workers' compensation benefits to civilian officers and employees of all branches of...

  7. 20 CFR 10.0 - What are the provisions of the FECA, in general?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false What are the provisions of the FECA, in general? 10.0 Section 10.0 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF... the payment of workers' compensation benefits to civilian officers and employees of all branches of...

  8. Cleanup Verification Package for the 100-F-20, Pacific Northwest Laboratory Parallel Pits

    SciTech Connect

    M. J. Appel

    2007-01-22

    This cleanup verification package documents completion of remedial action for the 100-F-20, Pacific Northwest Laboratory Parallel Pits waste site. This waste site consisted of two earthen trenches thought to have received both radioactive and nonradioactive material related to the 100-F Experimental Animal Farm.

  9. 20 CFR 220.100 - Evaluation of disability for any regular employment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Railroad Retirement Act based on disability for any regular employment. Regular employment means... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Evaluation of disability for any regular employment. 220.100 Section 220.100 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE...

  10. 20 CFR 220.100 - Evaluation of disability for any regular employment.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Railroad Retirement Act based on disability for any regular employment. Regular employment means... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Evaluation of disability for any regular employment. 220.100 Section 220.100 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE...

  11. 20 CFR 10.100 - How and when is a notice of traumatic injury filed?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false How and when is a notice of traumatic injury filed? 10.100 Section 10.100 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF... filed? (a) To claim benefits under the FECA, an employee who sustains a work-related traumatic...

  12. The absolute magnitude distribution of cold classical Kuiper belt objects

    NASA Astrophysics Data System (ADS)

    Petit, Jean-Marc; Bannister, Michele T.; Alexandersen, Mike; Chen, Ying-Tung; Gladman, Brett; Gwyn, Stephen; Kavelaars, JJ; Volk, Kathryn

    2016-10-01

    We report measurements of the low inclination component of the main Kuiper Belt showing a size freqency distribution very steep for sizes larger than H_r ~ 6.5-7.0 and then a flattening to shallower slope that is still steeper than the collisional equilibrium slope.The Outer Solar System Origins Survey (OSSOS) is ongoing and is expected to detect over 500 TNOs in a precisely calibrated and characterized survey. Combining our current sample with CFEPS and the Alexandersen et al. (2015) survey, we analyse a sample of ~180 low inclination main classical (cold) TNOs, with absolute magnitude H_r (SDSS r' like flter) in the range 5 to 8.8. We confirm that the H_r distribution can be approximated by an exponential with a very steep slope (>1) at the bright end of the distribution, as has been recognized long ago. A transition to a shallower slope occurs around H_r ~ 6.5 - 7.0, an H_r mag identified by Fraster et al (2014). Faintward of this transition, we find a second exponential to be a good approximation at least until H_r ~ 8.5, but with a slope significantly steeper than the one proposed by Fraser et al. (2014) or even the collisional equilibrium value of 0.5.The transition in the cold TNO H_r distribution thus appears to occur at larger sizes than is observed in the high inclination main classical (hot) belt, an important indicator of a different cosmogony for these two sub-components of the main classical Kuiper belt. Given the largish slope faintward of the transition, the cold population with ~100 km diameter may dominate the mass of the Kuiper belt in the 40 AU < a < 47 au region.

  13. The Curiously Warped Mean Plane of the Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Volk, Kathryn; Malhotra, Renu

    2017-08-01

    We measured the mean plane of the Kuiper Belt as a function of semimajor axis. For the classical Kuiper Belt as a whole (the nonresonant objects in the semimajor axis range 42-48 au), we find a mean plane of inclination {i}m=1\\buildrel{\\circ}\\over{.} {8}-0\\buildrel{\\circ\\over{.} 4}+0\\buildrel{\\circ\\over{.} 7} and longitude of ascending node {{{Ω }}}m=77{^\\circ }-{14^\\circ }+{18^\\circ } (in the J2000 ecliptic-equinox coordinate system), in accord with theoretical expectations of the secular effects of the known planets. With finer semimajor axis bins, we detect a statistically significant warp in the mean plane near semimajor axes 40-42 au. Linear secular theory predicts a warp near this location due to the {ν }18 nodal secular resonance; however, the measured mean plane for the 40.3-42 au semimajor axis bin (just outside the {ν }18) is inclined ˜ 13^\\circ to the predicted plane, a nearly 3σ discrepancy. For the more distant Kuiper Belt objects of semimajor axes in the range 50-80 au, the expected mean plane is close to the invariable plane of the solar system, but the measured mean plane deviates greatly from this: it has inclination {i}m=9\\buildrel{\\circ}\\over{.} {1}-3\\buildrel{\\circ\\over{.} 8}+6\\buildrel{\\circ\\over{.} 6} and longitude of ascending node {{{Ω }}}m=227{^\\circ }-{44^\\circ }+{18^\\circ }. We estimate this deviation from the expected mean plane to be statistically significant at the ˜97%-99% confidence level. We discuss several possible explanations for this deviation, including the possibility that a relatively close-in (a≲ 100 au), unseen, small planetary-mass object in the outer solar system is responsible for the warping.

  14. Kuipers works with Stowage in ATV3

    NASA Image and Video Library

    2012-05-15

    ISS031-E-084591 (15 May 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 31 flight engineer, is pictured during cargo operations in ESA?s "Edoardo Amaldi" Automated Transfer Vehicle-3 (ATV-3) currently docked with the International Space Station.

  15. Kuipers and Kononenko in the Node 1

    NASA Image and Video Library

    2011-12-27

    ISS030-E-033361 (27 Dec. 2011) --- European Space Agency astronaut Andre Kuipers (left) and Russian cosmonaut Oleg Kononenko, both Expedition 30 flight engineers, are pictured near food containers floating freely at the galley in the Unity node of the International Space Station.

  16. Planetary Migration and Kuiper Belt Dynamics

    NASA Astrophysics Data System (ADS)

    Malhotra, Renu

    The Kuiper belt holds memory of the dynamical processes that shaped the architecture of the solar system, including the orbital migration history of the giant planets. We propose studies of the orbital dynamics of the Kuiper Belt in order to understand the origin of its complex dynamical structure and its link to the orbital migration history of the giant planets. By means of numerical simulations, statistical tests, as well as analytical calculations we will (1) investigate the origin of resonant Kuiper belt objects to test alternative scenarios of Neptune's migration history, (2) investigate the long term dynamical evolution of the Haumea family of Kuiper Belt objects in order to improve the age estimate of this family, and (3) investigate resonance-sticking behavior and the Kozai-Lidov mechanism and its role in the origin of the extended scattered disk. These studies directly support the goals of the NASA-OSS program by improving our understanding of the origin of the solar system's architecture. Our results will provide constraints on the nature and timing of the dynamical excitation event that is thought to have occurred in early solar system history and to have determined the architecture of the present-day solar system; our results will also provide deeper theoretical understanding of sticky mean motion resonances which contribute greatly to the longevity of many small bodies, improve our understanding of dynamical transport of planetesimals in planetary systems, and help interpret observations of other planetary systems.

  17. G. P. Kuiper's Early Studies of Planets

    NASA Astrophysics Data System (ADS)

    Cruikshank, D. P.

    2005-08-01

    Gerard P. Kuiper was born on December 7, 1905; this is his centennial year. While he had an early interest in Solar System bodies, writing an extensive review about Mars for the popular Dutch astronomy journal, Hemel en Dampkring in 1931, Kuiper's first important observations began in 1944, when he discovered the atmosphere of Titan. In a letter dated February 29, 1944, to Lick Observatory director Joseph H. Moore, Kuiper noted that, ``The only reason I happened to observe the planets and the 10 brightest satellites was that they were nicely lined up in a region of the sky where I had run out of program stars (stars of large proper motion and parallax)." These spectroscopic observations were obtained with the new McDonald 82-inch telescope during a break from Kuiper's war-time work at Harvard's Radio Research Laboratory. In a letter of congratulations, his friend S. Chandrasekhar wrote, ``It is only on the impact of such discoveries that one realizes afresh the permanent value of science which no war -- not even of Hitler's -- can truly undermine. And it must be of satisfaction to you that if you took a vacation from war-work, it was only to make a fundamental discovery!" Using detectors declassified at the end of World War II, Kuiper began a study of the infrared spectra of planets and stars (with the first publication in 1947) that continued to the time of his death (December 24, 1973). Early in this work, on March 2, 1948, he wrote a lengthy letter to Henry Norris Russell in which he succinctly and enthusiastically summarized his observations and discoveries. Details in this letter give a fascinating perspective on some of the earliest physical studies of Solar System bodies, such as the detection of water ice on Saturn's rings and in the polar cap of Mars, spectral and photometric measurements of Mars' surface and atmospheric haze, and the discovery of Miranda.

  18. The laser radar above 30 kilometers

    NASA Technical Reports Server (NTRS)

    Clemesha, B. R.

    1969-01-01

    A short "state of the art' report on laser radar observations of the atmosphere at heights greater than 30 km is presented. Graphs of recent measurements of the Rayleigh backscattering function between 30 and 70 and above 50 kilometers are included.

  19. Off-Earth Driving Champs in Kilometers

    NASA Image and Video Library

    2009-10-13

    The total distance driven on Mars by NASA Mars Exploration Rover, 34.36 kilometers by early December 2011, is approaching the record total for off-Earth driving, held by the robotic Lunokhod 2 rover operated on Earth moon by the Soviet Union in 1973.

  20. Kuiper Belt Dust Grains as a Source of Interplanetary Dust Particles

    NASA Technical Reports Server (NTRS)

    Liou, Jer-Chyi; Zook, Herbert A.; Dermott, Stanley F.

    1996-01-01

    The recent discovery of the so-called Kuiper belt objects has prompted the idea that these objects produce dust grains that may contribute significantly to the interplanetary dust population. In this paper, the orbital evolution of dust grains, of diameters 1 to 9 microns, that originate in the region of the Kuiper belt is studied by means of direct numerical integration. Gravitational forces of the Sun and planets, solar radiation pressure, as well as Poynting-Robertson drag and solar wind drag are included. The interactions between charged dust grains and solar magnetic field are not considered in the model. Because of the effects of drag forces, small dust grains will spiral toward the Sun once they are released from their large parent bodies. This motion leads dust grains to pass by planets as well as encounter numerous mean motion resonances associated with planets. Our results show that about 80% of the Kuiper belt grains are ejected from the Solar System by the giant planets, while the remaining 20% of the grains evolve all the way to the Sun. Surprisingly, the latter dust grains have small orbital eccentricities and inclinations when they cross the orbit of the Earth. This makes them behave more like asteroidal than cometary-type dust particles. This also enhances their chances of being captured by the Earth and makes them a possible source of the collected interplanetary dust particles; in particular, they represent a possible source that brings primitive/organic materials from the outer Solar System to the Earth. When collisions with interstellar dust grains are considered, however, Kuiper belt dust grains around 9 microns appear likely to be collisionally shattered before they can evolve toward the inner part of the Solar System. The collision destruction can be applied to Kuiper belt grains up to about 50 microns. Therefore, Kuiper belt dust grains within this range may not be a significant part of the interplanetary dust complex in the inner Solar

  1. HST observations of Kuiper Belt binaries

    NASA Astrophysics Data System (ADS)

    Margot, J. L.; Brown, M. E.; Trujillo, C. A.; Sari, R.

    2004-11-01

    We report preliminary results from a Hubble Space Telescope (HST) program designed to characterize the orbital and physical properties of six confirmed KBO binaries [Margot et al. 2003]. Our results show that KBOs in our sample have much smaller sizes and larger albedos than expected, possibly requiring continuous collisional resurfacing and implying a Kuiper Belt that is less massive than previously assumed. Table 1 describes a subset of four KBO binaries that can be clearly resolved only with HST (1999 TC36, 1998 SM165, 2001 QC298, 1997 CQ29). The orbital period P and semi-major axis a yield the total mass of the binary M. Uncertainties listed are three times the formal errors of the fit or 1%, whichever is greater. The primary to secondary radius ratio Rp/R_s is based on flux measurements in HST's F606W filter. We used the absolute magnitudes as reported by JPL's Horizons system, assumed that binary components have identical albedos and densities, and derived the densities corresponding to geometric albedos of 5%, 10%, and 20%. Most KBOs in our sample must have albedos in excess of the radiometric average of 8% [Altenhoff et al., 2004] otherwise their density would be implausibly low. For unit density, the primary radii/geometric albedos are (147 km, 23%), (116 km, 15%), (117 km, 7.6%), and (42 km, 41%). Detection of such small KBOs in the IR/mm is challenging. \\begin{tabular}[h]{rrrrrrrr} & P [days] & a [km] & M [1018 kg]& (Rp)/(R_s) & ρ 5 & ρ 10 & ρ 20 TC& 50.38 ± 0.5 & 7640 ± 460 & 13.9 ± 2.5 & 2.7 & 0.1 & 0.3 & 0.8 SM& 130.1 ± 1 & 11310 ± 110 & 6.78 ± 0.24 & 3.0 & 0.2 & 0.5 & 1.5 QC& 19.23 ± 0.2 & 3690 ± 70 & 10.8 ± 0.7 & 1.2 & 0.5 & 1.5 & 4.3 CQ& 309.2 ± 3 & 8320 ± 240 & 0.48 ± 0.04 & 1.2 & - & 0.1 & 0.3 References Margot, Brown, Trujillo, Sari, HST General Observer Prgm 9746, 2003. Altenhoff, Bertoldi, Menten, A&A 415, 2004.

  2. Formation and Collisional Evolution of Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Kenyon, S. J.; Bromley, B. C.; O'Brien, D. P.; Davis, D. R.

    This chapter summarizes analytic theory and numerical calculations for the formation and collisional evolution of Kuiper belt objects (KBOs) at 20-150 AU. We describe the main predictions of a baseline self-stirring model and show how dynamical perturbations from a stellar flyby or stirring by a giant planet modify the evolution. Although robust comparisons between observations and theory require better KBO statistics and more comprehensive calculations, the data are broadly consistent with KBO formation in a massive disk followed by substantial collisional grinding and dynamical ejection. However, there are important problems reconciling the results of coagulation and dynamical calculations. Contrasting our current understanding of the evolution of KBOs and asteroids suggests that additional observational constraints, such as the identification of more dynamical families of KBOs (like the 2003 EL61 family), would provide additional information on the relative roles of collisional grinding and dynamical ejection in the Kuiper belt. The uncertainties also motivate calculations that combine collisional and dynamical evolution, a "unified" calculation that should give us a better picture of KBO formation and evolution.

  3. Quaoar: A Rock in the Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Fraser, Wesley C.; Brown, Michael E.

    2010-05-01

    Here we report Wide-Field Planetary Camera 2 observations of the Quaoar-Weywot Kuiper Belt binary. From these observations, we find that Weywot is on an elliptical orbit with an eccentricity of 0.14 ± 0.04, a period of 12.438 ± 0.005 days, and a semimajor axis of 1.45 ± 0.08 × 104 km. The orbit reveals a surprisingly high-Quaoar-Weywot system mass of (1.6 ± 0.3) × 1021 kg. Using the surface properties of the Uranian and Neptunian satellites as a proxy for Quaoar's surface, we reanalyze the size estimate from Brown & Trujillo. We find, from a mean of available published size estimates, a diameter for Quaoar of 890 ± 70 km. We find Quaoar's density to be ρ = 4.2 ± 1.3gcm-3, possibly the highest density in the Kuiper Belt.

  4. QUAOAR: A ROCK IN THE KUIPER BELT

    SciTech Connect

    Fraser, Wesley C.; Brown, Michael E.

    2010-05-10

    Here we report Wide-Field Planetary Camera 2 observations of the Quaoar-Weywot Kuiper Belt binary. From these observations, we find that Weywot is on an elliptical orbit with an eccentricity of 0.14 {+-} 0.04, a period of 12.438 {+-} 0.005 days, and a semimajor axis of 1.45 {+-} 0.08 x 10{sup 4} km. The orbit reveals a surprisingly high-Quaoar-Weywot system mass of (1.6 {+-} 0.3) x 10{sup 21} kg. Using the surface properties of the Uranian and Neptunian satellites as a proxy for Quaoar's surface, we reanalyze the size estimate from Brown and Trujillo. We find, from a mean of available published size estimates, a diameter for Quaoar of 890 {+-} 70 km. We find Quaoar's density to be {rho} = 4.2 {+-} 1.3gcm{sup -3}, possibly the highest density in the Kuiper Belt.

  5. 20 CFR 402.100 - Exemption six: Clearly unwarranted invasion of personal privacy.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Exemption six: Clearly unwarranted invasion... AVAILABILITY OF INFORMATION AND RECORDS TO THE PUBLIC § 402.100 Exemption six: Clearly unwarranted invasion of... constitute a clearly unwarranted invasion of their personal privacy. (b) Balancing test. In deciding...

  6. 20 CFR 666.100 - What performance indicators must be included in a State's plan?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false What performance indicators must be included... of Performance § 666.100 What performance indicators must be included in a State's plan? (a) All... for each of the core indicators of performance for the adult, dislocated worker and youth...

  7. 10 CFR 100.20 - Factors to be considered when evaluating sites.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... for Stationary Power Reactor Site Applications on or After January 10, 1997 § 100.20 Factors to be... determining the acceptability of a site for a stationary power reactor: (a) Population density and use... analysis or that may have an impact upon plant design (such as maximum probable wind speed...

  8. 10 CFR 100.20 - Factors to be considered when evaluating sites.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... for Stationary Power Reactor Site Applications on or After January 10, 1997 § 100.20 Factors to be... determining the acceptability of a site for a stationary power reactor: (a) Population density and use... analysis or that may have an impact upon plant design (such as maximum probable wind speed...

  9. 20 CFR 220.100 - Evaluation of disability for any regular employment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Evaluation of disability for any regular... RAILROAD RETIREMENT ACT DETERMINING DISABILITY Evaluation of Disability § 220.100 Evaluation of disability... Railroad Retirement Act based on disability for any regular employment. Regular employment...

  10. 20 CFR 220.100 - Evaluation of disability for any regular employment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Evaluation of disability for any regular... RAILROAD RETIREMENT ACT DETERMINING DISABILITY Evaluation of Disability § 220.100 Evaluation of disability... Railroad Retirement Act based on disability for any regular employment. Regular employment...

  11. 20 CFR 220.100 - Evaluation of disability for any regular employment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Evaluation of disability for any regular... RAILROAD RETIREMENT ACT DETERMINING DISABILITY Evaluation of Disability § 220.100 Evaluation of disability... Railroad Retirement Act based on disability for any regular employment. Regular employment...

  12. The Kuiper Belt of Four Gigayears Ago

    NASA Astrophysics Data System (ADS)

    Malhotra, Renu

    2008-09-01

    The Kuiper belt is largely dynamically stable on gigayear timescales, but weak orbital instabilities - also known as chaotic diffusion - have eroded its population by several tens of percent over the past 4 gigayears. Each of the dynamical subclasses in the Kuiper belt has slightly different loss rates. In this paper, I reconstruct the populations of the different subclasses as they were 4 gigayears ago, an epoch when the presently observed dynamical structure is thought to have been established. This exercise shows that the resonant/classical population ratio was significantly higher in the past, as also the scattered/classical population ratio; the resonant Twotino/Plutino population ratio was also much greater in the past. Such a historical projection is necessary for testing and constraining theories for the origin of the dynamical structure of the Kuiper belt. The differential loss rates of the various KB dynamical classes are also of interest for understanding the sources of impactors that are recorded in the impact craters on solid planetary bodies, as well as for establishing the provenance of transient small bodies, such as the Centaurs and the Jupiter family comets. This research was supported in part by grants from NASA's Origins of Solar Systems and Outer Planets Research programs.

  13. CHAOTIC DIFFUSION OF RESONANT KUIPER BELT OBJECTS

    SciTech Connect

    Tiscareno, Matthew S.; Malhotra, Renu

    2009-09-15

    We carried out extensive numerical orbit integrations to probe the long-term chaotic dynamics of the two strongest mean-motion resonances of Neptune in the Kuiper Belt, the 3:2 (Plutinos) and 2:1 (Twotinos). Our primary results include a computation of the relative volumes of phase space characterized by large- and small-resonance libration amplitudes, and maps of resonance stability measured by mean chaotic diffusion rate. We find that Neptune's 2:1 resonance has weaker overall long-term stability than the 3:2-only {approx}15% of Twotinos are projected to survive for 4 Gyr, compared to {approx}27% of Plutinos, based on an extrapolation from our 1-Gyr integrations. We find that Pluto has only a modest effect, causing a {approx}4% decrease in the Plutino population that survives to 4 Gyr. Given current observational estimates, and assuming an initial distribution of particles proportional to the local phase-space volume in the resonance, we conclude that the primordial populations of Plutinos and Twotinos formerly made up more than half the population of the classical and resonant Kuiper Belt. We also conclude that Twotinos were originally nearly as numerous as Plutinos; this is consistent with predictions from early models of smooth giant planet migration and resonance sweeping of the Kuiper Belt and provides a useful constraint for more detailed models.

  14. IDENTIFYING COLLISIONAL FAMILIES IN THE KUIPER BELT

    SciTech Connect

    Marcus, Robert A.; Ragozzine, Darin; Murray-Clay, Ruth A.; Holman, Matthew J.

    2011-05-20

    The identification and characterization of numerous collisional families-clusters of bodies with a common collisional origin-in the asteroid belt has added greatly to the understanding of asteroid belt formation and evolution. More recent study has also led to an appreciation of physical processes that had previously been neglected (e.g., the Yarkovsky effect). Collisions have certainly played an important role in the evolution of the Kuiper Belt as well, though only one collisional family has been identified in that region to date, around the dwarf planet Haumea. In this paper, we combine insights into collisional families from numerical simulations with the current observational constraints on the dynamical structure of the Kuiper Belt to investigate the ideal sizes and locations for identifying collisional families. We find that larger progenitors (r {approx} 500 km) result in more easily identifiable families, given the difficulty in identifying fragments of smaller progenitors in magnitude-limited surveys, despite their larger spread and less frequent occurrence. However, even these families do not stand out well from the background. Identifying families as statistical overdensities is much easier than characterizing families by distinguishing individual members from interlopers. Such identification seems promising, provided the background population is well known. In either case, families will also be much easier to study where the background population is small, i.e., at high inclinations. Overall, our results indicate that entirely different techniques for identifying families will be needed for the Kuiper Belt, and we provide some suggestions.

  15. The gravitational sculpting of the Kuiper belt

    NASA Astrophysics Data System (ADS)

    Levison, H. F.; Duncan, M. J.

    1993-03-01

    Results are presented of numerical integrations over billion year time scales of the orbital evolution of more than one thousand test particles on initially low-inclination, low-eccentricity orbits within the proposed Kuiper belt beyond Neptune. Particles which eventually crossed Neptune's orbit often showed long periods (up to several billion years) of relatively low-eccentricity oscillations punctuated by a very rapid jump to Neptune-crossing eccentricity. This flux may be the ultimate source of present-day short-period comets. It is found here that there exists a correlation between Liapunov and crossing times in the Kuiper belt. None of the particles in the study with Liapunov time scales greater than about 1 Myr actually became a Neptune-crosser in 4 Gyr. An intricate structure to the region between 35 and 45 AU is found at the end of the billion year simulation. Implications for the origins of short-period comets and the detectability of objects currently in the Kuiper belt are discussed.

  16. Planet Imager Discovers Young Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-07-01

    A debris disk just discovered around a nearby star is the closest thing yet seen to a young version of the Kuiper belt. This disk could be a key to better understanding the interactions between debris disks and planets, as well as how our solar system evolved early on in its lifetime. Hunting for an analog The best way to understand how the Kuiper belt — home to Pluto and thousands of other remnants of early icy planet formation in our solar system — developed would be to witness a similar debris disk in an earlier stage of its life. But before now, none of the disks we've discovered have been similar to our own: the rings are typically too large, the central star too massive, or the stars exist in regions very unlike what we think our Sun's birthplace was like. A collaboration led by Thayne Currie (National Astronomical Observatory of Japan) has changed this using the Gemini Planet Imager (GPI), part of a new generation of extreme adaptive-optics systems. The team discovered a debris disk of roughly the same size as the Kuiper belt orbiting the star HD 115600, located in the nearest OB association. The star is only slightly more massive than our Sun, and it lives in a star-forming region similar to the early Sun's environment. HD 115600 is different in one key way, however: it is only 15 million years old. This means that observing it gives us the perfect opportunity to observe how our solar system might have behaved when it was much younger. A promising future GPI's spatially-resolved spectroscopy, combined with measurements of the reflectivity of the disk, have led the team to suspect that the disk might be composed partly of water ice, just as the Kuiper belt is. The disk also shows evidence of having been sculpted by the motions of giant planets orbiting the central star, in much the same way as the outer planets of our solar system may have shaped the Kuiper belt. The observations of HD 115600 are some of the very first to emerge from GPI and the new

  17. 33 CFR 100.20 - Action on application for event assigned to State regulation by Coast Guard-State agreement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... assigned to State regulation by Coast Guard-State agreement. 100.20 Section 100.20 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.20 Action on application for event assigned to State regulation by Coast...

  18. 33 CFR 100.20 - Action on application for event assigned to State regulation by Coast Guard-State agreement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... assigned to State regulation by Coast Guard-State agreement. 100.20 Section 100.20 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.20 Action on application for event assigned to State regulation by Coast...

  19. New Horizons mission to Pluto and the Kuiper belt

    NASA Astrophysics Data System (ADS)

    McKinnon, W.; Stern, S.; Weaver, H.; Young, L.; Olkin, C.; New Horizons Science Team

    2014-07-01

    two 30--50 kilometer-diameter Kuiper Belt Objects (KBOs) if 1) the spacecraft is in good health, 2) at least one accessible KBO can be located from the Earth or Earth orbit in time, and 3) NASA approves an extended mission. New Horizons previously conducted a successful encounter with Jupiter and the Galilean satellites, has collected and is collecting valuable cruise science data, and became the prototype for NASA's medium-scale, PI-led New Frontiers planetary mission class. The NH flyby of the Pluto system will represent a watershed in the scientific exploration of the Solar System, by exploring a new class of planet in the Solar System --- dwarf planets --- and an accompanying, extensive satellite system. In this review talk we provide a more in-depth overview of the spacecraft, payload, and flyby plans.

  20. Synthesis and characterization of Bi x (Se80Te20)100- x amorphous thin films

    NASA Astrophysics Data System (ADS)

    Abdel-Rahim, F. M.

    2016-05-01

    In this study, amorphous Bi x (Se80Te20)100- x glasses with (0 ≤ x ≤ 12) were prepared by the usual melt quench technique. Thin films of these glasses were deposited onto glass substrates by using thermal evaporation method. The amorphous nature of the as-prepared films was confirmed by X-ray diffraction. Structural investigations were performed using X-ray energy-dispersive spectroscopy, X-ray diffraction and high-resolution transmission electron microscopy. The transmission spectra of these films were measured at normal incidence in the wavelength range 400-2500 nm. Swanepoel's analysis of the maxima and minima of the interference fringes was used to determine the film thickness, the complex index of refraction and the extinction coefficient with high accuracy. The dispersion of the refractive index was well discussed in terms of the single oscillator model (Wemple and DiDomenico). It was found that increasing Bi content led to the increase in refractive index and the extinction coefficient of the Bi x (Se80Te20)100-x films, while the optical band gap decreased. The mechanism of the optical absorption in Bi x (Se80Te20)100- x films obeyed the allowed indirect optical transition. The decrease in optical gap with increasing Bi content was discussed in terms of the chemical bond approach.

  1. High spatial resolution mapping of the Cepheus A region at 20, 50, and 100 microns

    NASA Technical Reports Server (NTRS)

    Ellis, H. B., Jr.; Lester, D. F.; Harvey, P. M.; Joy, M.; Telesco, C. M.; Decher, R.; Werner, M. W.

    1990-01-01

    The Cepheus A region at 20 microns has been mapped, and a bright, unresolved central source with a peak flux of 41 Jy into a 4.0 arcsec x 4.3 arcsec beam has been detected. One-dimensional slit scans have been obtained in two perpendicular directions across Cepheus A at 50 and 100 microns using a high spatial-resolution sampling technique. The temperature and optical depth profile of the far-IR emission are determined, and a peak temperature of 46 K and peak 100 micron optical depth of 0.4 are derived. Maximum entropy deconvolution of the far-IR scans indicate that there is a bright central core with clumpy extended emission. Within errors the position of the 50/100 micron peak is the same as the 20-micron source; this is interpreted as indicating that the 20 micron radiation represents the short-wavelength emission from the core of the dust cloud seen in the far-IR. It is concluded that an embedded source provides the major source of luminosity in the Cepheus A region.

  2. Precise Astrometry for Predicting Kuiper Belt Object Occultations

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott; Person, Michael; Zuluaga, Carlos; Bosh, Amanda

    2012-08-01

    Occultations by Kuiper Belt objects remain elusive events, requiring precision astrometry for these faint bodies in the outer solar system. Routine astrometry provides data that are crucial for our KBO ephemeris correction models, which then allow accurate shadow track predictions. Through the occultation events the diameters, possible companions and tenuous atmospheres around these objects will be explored by examining how the light from the star varies as the KBO passes in front of it. This is a powerful way to determine the physical characteristics of the KBOs. We propose to obtain very precise astrometry on 20 of the brightest known KBOs to determine more accurate orbits and thus reliable occultation predictions. We also require telescope time to obtain precise astrometry on possible stars that will be occulted by a KBO in the future.

  3. Surface composition of Kuiper belt object 1993SC.

    PubMed

    Brown, R H; Cruikshank, D P; Pendleton, Y; Veeder, G J

    1997-05-09

    The 1.42- to 2.40-micrometer spectrum of Kuiper belt object 1993SC was measured at the Keck Observatory in October 1996. It shows a strongly red continuum reflectance and several prominent infrared absorption features. The strongest absorptions in 1993SC's spectrum occur near 1.62, 1.79, 1.95, 2.20, and 2.32 micrometers in wavelength. Features near the same wavelengths in the spectra of Pluto and Neptune's satellite Triton are due to CH4 on their surfaces, suggesting the presence of a simple hydrocarbon ice such as CH4, C2H6, C2H4, or C2H2 on 1993SC. In addition, the red continuum reflectance of 1993SC suggests the presence of more complex hydrocarbons.

  4. Surface composition of Kuiper belt object 1993SC

    NASA Technical Reports Server (NTRS)

    Brown, R. H.; Cruikshank, D. P.; Pendleton, Y.; Veeder, G. J.

    1997-01-01

    The 1.42- to 2.40-micrometer spectrum of Kuiper belt object 1993SC was measured at the Keck Observatory in October 1996. It shows a strongly red continuum reflectance and several prominent infrared absorption features. The strongest absorptions in 1993SC's spectrum occur near 1.62, 1.79, 1.95, 2.20, and 2.32 micrometers in wavelength. Features near the same wavelengths in the spectra of Pluto and Neptune's satellite Triton are due to CH4 on their surfaces, suggesting the presence of a simple hydrocarbon ice such as CH4, C2H6, C2H4, or C2H2 on 1993SC. In addition, the red continuum reflectance of 1993SC suggests the presence of more complex hydrocarbons.

  5. Phobos from 5,800 Kilometers

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took two images of the larger of Mars' two moons, Phobos, within 10 minutes of each other on March 23, 2008. This is the second, taken from a distance of about 5,800 kilometers (about 3,600 miles). The illuminated part of Phobos seen in the images is about 21 kilometers (13 miles) across.

    The most prominent feature in the images is the large crater Stickney in the lower right. With a diameter of 9 kilometers (5.6 miles), it is the largest feature on Phobos. A series of troughs and crater chains is obvious on other parts of the moon. Although many appear radial to Stickney in this image, recent studies from the European Space Agency's Mars Express orbiter indicate that they are not related to Stickney. Instead, they may have formed when material ejected from impacts on Mars later collided with Phobos. The lineated textures on the walls of Stickney and other large craters are landslides formed from materials falling into the crater interiors in the weak Phobos gravity (less than one one-thousandth of the gravity on Earth).

    In the full-resolution version of this image, a pixel encompasses 5.8 meters (19 feet), providing a resolution (smallest visible feature) of about 15 meters (about 50 feet). Previous pictures from NASA's Mars Global Surveyor are of slightly higher resolution, at 4 meters (13 feet) per pixel. However, the HiRISE images have higher signal-to-noise, making the new data some of the best ever for Phobos.

    Although the image is displayed here in black and white, data from HiRISE's three color channels were used to give higher signal-to-noise, thereby increasing detail. The image is in the HiRISE catalog as PSP_007769_9015.

    NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin

  6. Phobos from 5,800 Kilometers (Color)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took two images of the larger of Mars' two moons, Phobos, within 10 minutes of each other on March 23, 2008. This is the second, taken from a distance of about 5,800 kilometers (about 3,600 miles). It is presented in color by combining data from the camera's blue-green, red, and near-infrared channels.

    The illuminated part of Phobos seen in the images is about 21 kilometers (13 miles) across. The most prominent feature in the images is the large crater Stickney in the lower right. With a diameter of 9 kilometers (5.6 miles), it is the largest feature on Phobos.

    The color data accentuate details not apparent in black-and-white images. For example, materials near the rim of Stickney appear bluer than the rest of Phobos. Based on analogy with materials on our own moon, this could mean this surface is fresher, and therefore younger, than other parts of Phobos.

    A series of troughs and crater chains is obvious on other parts of the moon. Although many appear radial to Stickney in this image, recent studies from the European Space Agency's Mars Express orbiter indicate that they are not related to Stickney. Instead, they may have formed when material ejected from impacts on Mars later collided with Phobos. The lineated textures on the walls of Stickney and other large craters are landslides formed from materials falling into the crater interiors in the weak Phobos gravity (less than one one-thousandth of the gravity on Earth).

    In the full-resolution version of this image, a pixel encompasses 5.8 meters (19 feet), providing a resolution (smallest visible feature) of about 15 meters (about 50 feet). Previous pictures from NASA's Mars Global Surveyor are of slightly higher resolution, at 4 meters (13 feet) per pixel. However, the HiRISE images have higher signal-to-noise, making the new data some of the best ever for Phobos. This image is in the Hi

  7. Kuipers trims his hair in the Node 3

    NASA Image and Video Library

    2011-12-30

    ISS030-E-033548 (30 Dec. 2011) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, trims his hair in the Tranquility node of the International Space Station. Kuipers used hair clippers fashioned with a vacuum device to garner freshly cut hair.

  8. Kuipers trims his hair in the Node 3

    NASA Image and Video Library

    2011-12-30

    ISS030-E-033523 (30 Dec. 2011) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, trims his hair in the Tranquility node of the International Space Station. Kuipers used hair clippers fashioned with a vacuum device to garner freshly cut hair.

  9. Intensity interferometry: optical imaging with kilometer baselines

    NASA Astrophysics Data System (ADS)

    Dravins, Dainis

    2016-07-01

    Optical imaging with microarcsecond resolution will reveal details across and outside stellar surfaces but requires kilometer-scale interferometers, challenging to realize either on the ground or in space. Intensity interferometry, electronically connecting independent telescopes, has a noise budget that relates to the electronic time resolution, circumventing issues of atmospheric turbulence. Extents up to a few km are becoming realistic with arrays of optical air Cherenkov telescopes (primarily erected for gamma-ray studies), enabling an optical equivalent of radio interferometer arrays. Pioneered by Hanbury Brown and Twiss, digital versions of the technique have now been demonstrated, reconstructing diffraction-limited images from laboratory measurements over hundreds of optical baselines. This review outlines the method from its beginnings, describes current experiments, and sketches prospects for future observations.

  10. Toxicity of DMSO, Triton X 100 and Tween 20 against Rhipicephalus (Boophilus) annulatus.

    PubMed

    Ravindran, Reghu; Juliet, Sanis; Gopalan, Ajith Kumar Karapparambu; Kavalimakkil, Amithamol Krishnan; Ramankutty, Sunil Athalathil; Nair, Suresh Narayanan; Narayanan, Priya Manakkulamparambil; Ghosh, Srikanta

    2011-10-01

    The problems associated with synthetic chemical pesticides include resistance, residues, pest resurgence and the adverse effects on non-target organisms. Hence, many ecofriendly newer alternatives are being evaluated among which one of the most important is the use of herbal agents. Many of the plant extracts or its fractions are dissolved in polar or non polar solvents or detergents before tested for acaricidal activity. The solvent or detergent used for dissolving the herbal extract should have little or no acaricidal effects. In the present study, laboratory tests were carried out on engorged female Rhipicephalus (Boophilus) annulatus ticks to detect the toxicity of common diluents such as dimethyl sulfoxide (DMSO), Tween 20 and Triton X 100 at 1% concentration. The result of the study revealed that least acaricidal activity was with Triton X 100 while the other two inhibited the hatching of eggs laid by treated ticks.

  11. Microchannel plate pinhole camera for 20 to 100 keV x-ray imaging

    SciTech Connect

    Wang, C.L.; Leipelt, G.R.; Nilson, D.G.

    1984-10-03

    We present the design and construction of a sensitive pinhole camera for imaging suprathermal x-rays. Our device is a pinhole camera consisting of four filtered pinholes and microchannel plate electron multiplier for x-ray detection and signal amplification. We report successful imaging of 20, 45, 70, and 100 keV x-ray emissions from the fusion targets at our Novette laser facility. Such imaging reveals features of the transport of hot electrons and provides views deep inside the target.

  12. Kuiper belt structure around nearby super-Earth host stars

    NASA Astrophysics Data System (ADS)

    Kennedy, Grant M.; Matrà, Luca; Marmier, Maxime; Greaves, Jane S.; Wyatt, Mark C.; Bryden, Geoffrey; Holland, Wayne; Lovis, Christophe; Matthews, Brenda C.; Pepe, Francesco; Sibthorpe, Bruce; Udry, Stéphane

    2015-05-01

    We present new observations of the Kuiper belt analogues around HD 38858 and HD 20794, hosts of super-Earth mass planets within 1 au. As two of the four nearby G-type stars (with HD 69830 and 61 Vir) that form the basis of a possible correlation between low-mass planets and debris disc brightness, these systems are of particular interest. The disc around HD 38858 is well resolved with Herschel and we constrain the disc geometry and radial structure. We also present a probable James Clerk Maxwell Telescope sub-mm continuum detection of the disc and a CO J = 2-1 upper limit. The disc around HD 20794 is much fainter and appears marginally resolved with Herschel, and is constrained to be less extended than the discs around 61 Vir and HD 38858. We also set limits on the radial location of hot dust recently detected around HD 20794 with near-IR interferometry. We present High Accuracy Radial velocity Planet Searcher upper limits on unseen planets in these four systems, ruling out additional super-Earths within a few au, and Saturn-mass planets within 10 au. We consider the disc structure in the three systems with Kuiper belt analogues (HD 69830 has only a warm dust detection), concluding that 61 Vir and HD 38858 have greater radial disc extent than HD 20794. We speculate that the greater width is related to the greater minimum planet masses (10-20 M⊕ versus 3-5 M⊕), arising from an eccentric planetesimal population analogous to the Solar system's scattered disc. We discuss alternative scenarios and possible means to distinguish among them.

  13. Consequences of planetary migration: Kuiper belt dynamics and atmospheric escape from hot Jupiters

    NASA Astrophysics Data System (ADS)

    Murray-Clay, Ruth Ann

    The current resonance structure of the Kuiper belt suggests that during the late stages of planet formation, Neptune migrated outward as it scattered residual planetesimal debris. Extrasolar planetary systems also show evidence for planetary migration. Approximately 1/5 of the extrasolar planets discovered to date are "hot Jupiters," which likely exchanged angular momentum with gas disks, migrating large distances inward to reach their current semi-major axes of ~0.05 AU. In this thesis, I discuss three consequences of planetary migration. (1) During its migration, Neptune captured Kuiper belt objects (KBOs) into mean motion resonances. The current spatial distribution of KBOs in a particular resonance, the 2:1, acts as a celestial speedometer--fast planetary migration generates a larger population of 2:1 resonant KBOs trailing rather than leading Neptune on the sky. We provide an explanation of this phenomenon for the first time. Central to our understanding is how planetary migration shifts the equilibrium points of the superposed direct and indirect potentials felt by a KBO. The currently observed distribution of 2:1 KBOs excludes total migration times < 20 Myr with >99.65% confidence and is statistically consistent with the even population generated by slow migration. However, these observations are beset by systematic uncertainties. Observations with new telescopes such as PanSTARRS or LSST will tell us how quickly Neptune could have migrated. (2) Neptune's migration, powered by scattering planetesimal debris, was stochastic ("noisy"). Extreme stochasticity defeats resonance capture. We construct a theory analogous to Brownian motion for how a planet's orbital semi-major axis fluctuates in response to random planetesimal scatterings. The degree of stochasticity in Neptune's migration depends both on the sizes of the planetesimals driving migration and on their orbital elements and cannot currently be computed using N-body simulations. We find that capture of

  14. Update on the Square Kilometer Array

    NASA Astrophysics Data System (ADS)

    Tarter, Jill

    2002-01-01

    In August 2000 representatives of 24 groups in 10 countries signed a memorandum of understanding to continue cooperative technology development on five different antenna concepts intended to enable the cost-effective construction of a radio telescope array with one million square meters of collecting area; the Square Kilometer Array (SKA). The goal of this MOA is to find innovative ways of solving the many technical challenges posed by this mammouth array, and to drive down the costs so that this can realistically be afforded as a groundbased, international project for radio astronomy. The science drivers for this large instrument are diverse and very exciting; SETI being one of them. However, this means that the technical specifications are extremely challenging. There is historical reason to believe that these goals can be met. For the past six decades, the capability of radio astronomy facilities has been improving exponentially, and the SKA represents the logical extrapolation of this trend. In 2005 a selection of one or more of the current antenna concepts will be made, along with the choice of a suitable site and configuration for the array. Final detailed designs and prototyping will follow. Construction could start by the end of this decade. The SKA will permit SETI observations over a wider range of frequencies, and will offer a sensitivity that is two orders of magnitude better than current arrays. This improved performance justifies all the effort needed to overcome the technological, political, and bureaucratic challenges inherent in this international mega-science project.

  15. 78 FR 68331 - Energy Conservation Program: Request for Exclusion of 100 Watt R20 Short Incandescent Reflector...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-14

    ... marketed for use in pool and spa applications. Specifically, the lamp at issue is a 100-watt R20 short.... Background III. General Discussion A. Authority B. R20 Short Lamp Special Application Design and Impact on Energy Savings 1. Special Application of R20 Short Lamps a. R20 Short Lamp Design for Special...

  16. Beyond the Kuiper Belt Edge: Sednoids and the Inner Oort Cloud

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott S.; Trujillo, C.

    2013-10-01

    The Kuiper Belt is thought to be a relic from the original protoplanetary disk. This region contains some of the least processed material in the solar system and is the suspected source of the Centaurs and short period comets. Currently there are over one thousand Kuiper Belt objects known with perihelion between about 30 and 50 AU. Only one object is known to have a perihelion significantly beyond 50 AU (Sedna at 76 AU) even though shallow surveys to date should have found many such Sednoids if the size distribution beyond this ``edge'' is similar to what has been seen elsewhere in the Kuiper Belt. The strong size and heliocentric distance dependence of the flux density of sunlight scattered from an object requires a survey to obtain very faint magnitudes in order to access the population of objects of size 100 km and less beyond 50 AU. Kuiper Belt surveys to date have not been optimized to survey beyond the Kuiper Belt edge at 50 AU as they have either covered large areas but been to shallow depths (less than 23rd mag), have gone deep but covered a very small area of sky (a few square degrees), or do not have the required cadence to detect the ultra slow moving Sednoids or inner Oort cloud objects that are well beyond 50 AU. We are performing an ultra-deep wide-field outer solar system survey with the wide-field imagers on the large class Magellan 6.5 m and Subaru 8 m telescopes to determine if the objects beyond 50 AU are fainter than expected, if there is truly a dearth of objects, or if the Kuiper Belt continues again after some sizable gap possibly caused by a planet sized object. This survey is the widest deepest survey for such distant objects ever obtained. We will constrain the origin of Sedna and determine if this eccentric, distant body is unique (as once believed for Pluto) or just the first of a new class of object in the outer Solar System.

  17. Dynamical studies of the Kuiper belt and the Centaurs

    NASA Astrophysics Data System (ADS)

    Volk, Kathryn Margaret

    The Kuiper belt is a population of small bodies located outside Neptune's orbit. The observed Kuiper belt objects (KBOs) can be divided into several subclasses based on their dynamical structure. I construct models for these subclasses and use numerical integrations to investigate their long-term evolution. I use these models to quantify the connection between the Kuiper belt and the Centaurs (objects whose orbits cross the orbits of the giant planets) and the short-period comets in the inner solar system. I discuss how these connections could be used to determine the physical properties of KBOs and what future observations could conclusively link the comets and Centaurs to specific Kuiper belt subclasses. The Kuiper belt's structure is determined by a combination of long-term evolution and its formation history. The large eccentricities and inclinations of some KBOs and the prevalence of KBOs in mean motion resonances with Neptune are evidence that much of the Kuiper belt's structure originated during the solar system's epoch of giant planet migration; planet migration can sculpt the Kuiper belt's scattered disk, capture objects into mean motion resonances, and dynamically excite KBOs. Different models for planet migration predict different formation locations for the subclasses of the Kuiper belt, which might result in different size distributions and compositions between the subclasses; the high-inclination portion of the classical Kuiper belt is hypothesized to have formed closer to the Sun than the low-inclination classical Kuiper belt. I use my model of the classical Kuiper belt to show that these two populations remain largely dynamically separate over long timescales, so primordial physical differences could be maintained until the present day. The current Kuiper belt is much less massive than the total mass required to form its largest members. It must have undergone a mass depletion event, which is likely related to planet migration. The Haumea

  18. The small numbers of large Kuiper Belt objects

    SciTech Connect

    Schwamb, Megan E.; Brown, Michael E.; Fraser, Wesley C.

    2014-01-01

    We explore the brightness distribution of the largest and brightest (m(R) < 22) Kuiper Belt Objects (KBOs). We construct a luminosity function of the dynamically excited or hot Kuiper Belt (orbits with inclinations >5°) from the very brightest to m(R) = 23. We find for m(R) ≲ 23, a single slope appears to describe the luminosity function. We estimate that ∼12 KBOs brighter than m(R) ∼ 19.5 are present in the Kuiper Belt today. With nine bodies already discovered this suggests that the inventory of bright KBOs is nearly complete.

  19. Into the Kuiper Belt: New Horizons Post-Pluto

    NASA Astrophysics Data System (ADS)

    Harrison Parker, Alex; Spencer, John; Benecchi, Susan; Binzel, Richard; Borncamp, David; Buie, Marc; Fuentes, Cesar; Gwyn, Stephen; Kavelaars, JJ; Noll, Keith; Petit, Jean-Marc; Porter, Simon; Showalter, Mark; Stern, S. Alan; Sterner, Ray; Tholen, David; Verbiscer, Anne; Weaver, Hal; Zangari, Amanda

    2015-11-01

    New Horizons is now beyond Pluto and flying deeper into the Kuiper Belt. In the summer of 2014, a Hubble Space Telescope Large Program identified two candidate Cold Classical Kuiper Belt Objects (KBOs) that were within reach of New Horizons' remaining fuel budget. Here we present the selection of the Kuiper Belt flyby target for New Horizons' post-Pluto mission, our state of knowledge regarding this target and the potential 2019 flyby, the status of New Horizons' targeting maneuver, and prospects for near-future long-range observations of other KBOs.

  20. Kuiper Belt Objects Along the Pluto-Express Path

    NASA Technical Reports Server (NTRS)

    Jewitt, David (Principal Investigator)

    1997-01-01

    The science objective of this work is to identify objects in the Kuiper Belt which will, in the 5 years following Pluto encounter, be close to the flight path of NASA's Pluto Express. Our hope is that we will find a Kuiper Belt object or objects close enough that a spacecraft flyby will be possible. If we find a suitable object, the science yield of Pluto Express will be substantially enhanced. The density of objects in the Kuiper Belt is such that we are reasonably likely to find an object close enough to the flight path that on-board gas thrusters can effect a close encounter.

  1. Kuiper Belt Objects Along the Pluto-Express Path

    NASA Astrophysics Data System (ADS)

    Jewitt, David C.

    1997-11-01

    The science objective of this work is to identify objects in the Kuiper Belt which will, in the 5 years following Pluto encounter, be close to the flight path of NASA's Pluto Express. Our hope is that we will find a Kuiper Belt object or objects close enough that a spacecraft flyby will be possible. If we find a suitable object, the science yield of Pluto Express will be substantially enhanced. The density of objects in the Kuiper Belt is such that we are reasonably likely to find an object close enough to the flight path that on-board gas thrusters can effect a close encounter.

  2. Spectroscopy of Kuiper Belt Objects and Centaurs

    NASA Technical Reports Server (NTRS)

    Cruikshank, Dale P.; Brown, Robert H.; Pendleton, Y. J.; Veeder, Glenn J.

    1998-01-01

    Recent near-infrared spectroscopy of Kuiper Belt objects and Centaurs indicates considerable spectral diversity among them. Some have entirely bland spectra with no discernible spectral features (e.g., Chiron), while 5145 Pholus has a very active spectrum with absorption bands of H2O, CH3OH, and probably the mineral olivine present. In addition, the strong red color of Pholus indicates the presence of organic solids. Among the KBOs, 1993 SC has an active spectrum with the probably presence of hydrocarbons and possibly the ices of H2O and N2. The diversity among these spectra and the implications that such diversity has for models of the formation of the formation of the planets will be discussed.

  3. Molecular spectroscopy from the Kuiper Airborne Observatory

    NASA Technical Reports Server (NTRS)

    Beckwith, S.

    1985-01-01

    Interstellar and circumstellar molecules are investigated through medium-resolution infrared spectrosocpy of the vibration-rotation and pure rotational transitions. A primary goal was the construction and improvement of instrumentation for the near and middle infrared regions, wavelengths between 2 and 10 microns. The main instrument was a cooled grating spectrometer with an interchangeable detector focal plane which could be used on the Kuiper Airborne Observatory (KAO) for airborne observations, and also at ground-based facilities. Interstellar shock waves were investigated by H2 emission from the Orion Nebula, W51, and the proto-planetary nebulae CRL 2688 and CRL 618. The observations determined the physical conditions in shocked molecular gas near these objects. From these it was possible to characterize the energetic history of mass loss from both pre- and post-main sequence stars in the regions.

  4. Imaging Detectors for 20-100 ke V X-ray Backlighters in HEDES Petawatt Experiments

    SciTech Connect

    Wickersham, J E; Park, H; Bell, P M; Koch, J A; Landen, O L; Moody, J D

    2004-04-16

    We are developing a petawatt laser for use as a high energy backlighter source in the 20{approx} 100 keV range. High energy x-ray backlighters will be essential for radiographing High-Energy- Density Experimental Science (HEDES) targets for NIF projects especially to probe implosions and high areal density planar samples. For these experiments we are employing two types of detectors: a columnar grown CsI scintillator coupled to a 2K x 2K CCD camera and a CdTe crystal with a special ASIC readout electronics in a 508 x 512 format array. We have characterized these sensors using radioactive sources. In addition, we utilized them to measure the Sm K{alpha} source size generated by the short pulse laser, JanUSP, at LLNL. This paper will present the results of our characterizations of these detectors.

  5. INCLINATION MIXING IN THE CLASSICAL KUIPER BELT

    SciTech Connect

    Volk, Kathryn; Malhotra, Renu

    2011-07-20

    We investigate the long-term evolution of the inclinations of the known classical and resonant Kuiper Belt objects (KBOs). This is partially motivated by the observed bimodal inclination distribution and by the putative physical differences between the low- and high-inclination populations. We find that some classical KBOs undergo large changes in inclination over gigayear timescales, which means that a current member of the low-inclination population may have been in the high-inclination population in the past, and vice versa. The dynamical mechanisms responsible for the time variability of inclinations are predominantly distant encounters with Neptune and chaotic diffusion near the boundaries of mean motion resonances. We reassess the correlations between inclination and physical properties including inclination time variability. We find that the size-inclination and color-inclination correlations are less statistically significant than previously reported (mostly due to the increased size of the data set since previous works with some contribution from inclination variability). The time variability of inclinations does not change the previous finding that binary classical KBOs have lower inclinations than non-binary objects. Our study of resonant objects in the classical Kuiper Belt region includes objects in the 3:2, 7:4, 2:1, and eight higher-order mean motion resonances. We find that these objects (some of which were previously classified as non-resonant) undergo larger changes in inclination compared to the non-resonant population, indicating that their current inclinations are not generally representative of their original inclinations. They are also less stable on gigayear timescales.

  6. One arc-minute resolution maps of the Orion Nebula at 20, 50, and 100 microns

    NASA Technical Reports Server (NTRS)

    Werner, M. W.; Gatley, I.; Becklin, E. E.; Harper, D. A.; Loewenstein, R. F.; Telesco, C. M.; Thronson, H. A.

    1976-01-01

    The paper presents maps of the central regions of the Orion Nebula which are based on observations made at wavelengths of 20, 50, and 100 microns with a resolution of 1 arcmin. The 50- and 100-micron observations were made with the NASA 91-cm Airborne Infrared Telescope. The principal far-IR features observed include a sharp emission peak near the position of the IR cluster, about 1 arcmin northwest of the Trapezium; a ridge of emission that is elongated north-south about this peak; and a barlike feature running northeast to southwest about 2 arcmin southeast of the Trapezium. The following conclusions are reached about the nature of the far-IR emission: (1) the total luminosity (between 10 and 1000 microns) of the IR cluster exceeds the solar luminosity by a factor of at least 120,000; (2) heating by both the IR cluster and the Trapezium stars is important in producing the central emission ridge; (3) the IR cluster is located within the molecular cloud; (4) the Trapezium stars are no more than 0.1 pc from that cloud; and (5) the bar of emission southeast of the Trapezium can be identified with an optically visible ionization front.

  7. Sub-kilometer length scales in coastal waters

    NASA Astrophysics Data System (ADS)

    Blackwell, Shelley M.; Moline, Mark A.; Schaffner, Andrew; Garrison, Thomas; Chang, Grace

    2008-02-01

    Patchiness or spatial variability is ubiquitous in marine systems. With increasing anthropogenic impacts to coastal resources and coastal systems being disproportionately large contributors to ocean productivity, identifying the spatial scales of this patchiness, particularly in coastal waters, is of critical importance to understand coastal ecosystem dynamics. The current work focuses on fine scale structure in three coastal regions. More specifically, we utilize variogram analyses to identify sub-kilometer scales of variability in biological and physical parameters measured by an autonomous underwater vehicle (AUV) in the Mid-Atlantic Bight, Monterey Bay, and in San Luis Obispo Bay between 2001 and 2004. Critical scales of variability in density, turbidity, fluorescence, and bioluminescence are examined as a function of depth and distance offshore. Furthermore, the effects of undersampling are assessed using predictive error analysis. Results indicate the presence of scales of variability ranging from 10s to 100s of meters and provide valuable insight for sampling design and resource allocation for future studies.

  8. High-resolution synchrotron data collection for charge-density work at 100 and 20 K.

    PubMed

    Luger, Peter; Messerschmidt, Marc; Scheins, Stephan; Wagner, Armin

    2004-09-01

    For the measurement of very accurate high-resolution X-ray data for charge-density work, synchrotron beamlines provide a bright radiation source of outstanding properties. Most important are the very high primary intensity and the possibility of choosing hard radiation with lambda approximately 0.5 A or even shorter. This together with area detection and a stable low-temperature device means that accurate and large data sets can be measured in a short time. A number of data collections are reported, which were carried out at the beamlines F1 and D3 of Hasylab (DESY, Hamburg) first at 100 K and later at 15-20 K, demonstrating the quality of the measured intensities. A low temperature of around 20 K was obtained at beamline D3 with a double-stage closed-cycle helium cryostat where the standard beryllium cylinder of the vacuum chamber was replaced by a 0.1 mm Kapton film. Comparison of different data sets measured for a strychnine crystal demonstrated how I/sigma ratios favorably improve if synchrotron radiation at a low temperature of 15 K was used. Synchrotron-based studies on several biologically active compounds are briefly summarized and a synchrotron experiment of an otherwise not sufficiently diffracting crystal of a tetraphenyl barbaralane derivative is described in detail. Atomic volumes and charges of a highly substituted C(60) fullerene are reported derived from a synchrotron data set of more than 350000 reflections.

  9. Kuipers using communication equipment in the U.S. Laboratory

    NASA Image and Video Library

    2012-04-24

    ISS030-E-250651 (24 April 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, uses a communication system near a robotic workstation in the Destiny laboratory of the International Space Station.

  10. Kuipers configures the GCP in the ATV-3

    NASA Image and Video Library

    2012-04-06

    ISS030-E-210810 (6 April 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, configures the Gas Control Panel (GCP) in the Automated Transfer Vehicle (ATV-3) currently docked with the International Space Station.

  11. Kuipers holds Velocicalc Meter in the Node 3

    NASA Image and Video Library

    2012-01-28

    ISS030-E-166606 (28 Jan. 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, uses an instrument to measure air velocity in the Tranquility node of the International Space Station.

  12. Kuipers lubricates and cleans the beverage adapter on the PWD

    NASA Image and Video Library

    2012-01-23

    ISS030-E-156300 (23 Jan. 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, lubricates and cleans the beverage adapter on the Potable Water Dispenser (PWD) in the Harmony node of the International Space Station.

  13. Kilometer-scale Kaiser effect identified in Krafla volcano, Iceland

    NASA Astrophysics Data System (ADS)

    Heimisson, Elías Rafn; Einarsson, Páll; Sigmundsson, Freysteinn; Brandsdóttir, Bryndís.

    2015-10-01

    The Krafla rifting episode in 1975-1984, consisted of around 20 inflation-deflation events within the Krafla caldera, where magma accumulated during inflation periods and was intruded into the transecting fissure swarm during brief periods of deflation. We reanalyze geodetic and seismic data from the rifting episode and perform a time-dependent inversion of a leveling time series for a spherical point source in an elastic half-space. Using the volume change as a proxy for stress shows that during inflation periods the seismicity rate remains low until the maximum inflation of previous cycles is exceeded thus exhibiting the Kaiser effect. Our observations demonstrate that this phenomenon, commonly observed in small-scale experiments, is also produced in kilometer-scale volcanic deformation. This behavior sheds new light on the relationship between deformation and seismicity of a deforming volcano. As a consequence of the Kaiser effect, a volcano may inflate rapidly without significant changes in seismicity rate.

  14. Discovery of the candidate Kuiper belt object 1992 QB1

    NASA Technical Reports Server (NTRS)

    Jewitt, David; Luu, Jane

    1993-01-01

    The discovery of a new faint object in the outer solar system, 1992 QB1, moving beyond the orbit of Neptune is reported. It is suggested that the 1992 QB1 may represent the first detection of a member of the Kuiper belt (Edgworth, 1949; Kuiper, 1951), the hypothesized population of objects beyond Neptune and a possible source of the short-period comets, as suggested by Whipple (1964), Fernandez (1980), and Duncan et al. (1988).

  15. Kuiper Belt Objects Along the Pluto Express Path

    NASA Technical Reports Server (NTRS)

    Jewitt, David

    1999-01-01

    The objective of this proposal was to mount a ground-based search for Kuiper Belt objects near the trajectory of the NASA Pluto Express spacecraft. The high density of Kuiper Belt objects established from work on Mauna Kea makes it probable that one or more bodies can be visited by Pluto Express after its encounter with Pluto. The work was funded during its first year through NASA HQ. The second year was funded through Goddard. The third year was never funded.

  16. Kuiper Belt Objects Along the Pluto Express Path

    NASA Technical Reports Server (NTRS)

    Jewitt, David

    1999-01-01

    The objective of this proposal was to mount a ground-based search for Kuiper Belt objects near the trajectory of the NASA Pluto Express spacecraft. The high density of Kuiper Belt objects established from work on Mauna Kea makes it probable that one or more bodies can be visited by Pluto Express after its encounter with Pluto. The work was funded during its first year through NASA HQ. The second year was funded through Goddard. The third year was never funded.

  17. K-(alpha) Radiography at 20-100 keV Using Short-Pulse Lasers

    SciTech Connect

    Park, H S; Chambers, D; Clarke, R; Eagleton, R; Giraldez, E; Goldsack, T; Heathcote, R; Izumi, N; Key, M; King, J; Koch, J; Landen, O L; Mackinnon, A; Nikroo, A; Patel, P; Pasley, J; Remington, B; Robey, H; Snavely, R; Steinman, D; Stephenson, R; Stoeckl, C; Storm, M; Tabak, M; Theobald, W; Town, R J

    2005-08-29

    X-ray radiography is an important tool for diagnosing and imaging planar and convergent hydrodynamics phenomena for laser experiments. Until now, hydrodynamics experiments at Omega and NIF utilize E{sub x-ray} < 9 keV backlighter x-rays emitted by thermal plasmas. However, future experiments will need to diagnose larger and denser targets and will require x-ray probes of energies from 20-100 keV and possibly up to 1 MeV. Hard K-{alpha} x-ray photons can be created through high-energy electron interactions in the target material after irradiation by petawatt-class high-intensity-short-pulse lasers with > 10{sup 17} W/cm{sup 2}. We have performed several experiments on the JanUSP, and the Vulcan 100TW, and Vulcan Petawatt lasers to understand K-{alpha} sources and to test radiography concepts. 1-D radiography using an edge-on foil and 2-D radiography using buried wires and cone-fiber targets were tested. We find that 1-D thin edge-on foils can have imaging resolution better than 10 {micro}m. Micro volume targets produce bright sources with measured conversion efficiency from laser energy to x-ray photons of {approx} 1 x 10{sup -5}. This level of conversion may not be enough for 2-D point projection radiography. A comparison of our experimental measurements of small volume sources with the LSP/PIC simulation show similar K-{alpha} creation profiles but discrepancy in absolute yields.

  18. COLORS OF INNER DISK CLASSICAL KUIPER BELT OBJECTS

    SciTech Connect

    Romanishin, W.; Tegler, S. C.; Consolmagno, G. J. E-mail: Stephen.Tegler@nau.ed

    2010-07-15

    We present new optical broadband colors, obtained with the Keck 1 and Vatican Advanced Technology telescopes, for six objects in the inner classical Kuiper Belt. Objects in the inner classical Kuiper Belt are of interest as they may represent the surviving members of the primordial Kuiper Belt that formed interior to the current position of the 3:2 resonance with Neptune, the current position of the plutinos, or, alternatively, they may be objects formed at a different heliocentric distance that were then moved to their present locations. The six new colors, combined with four previously published, show that the ten inner belt objects with known colors form a neutral clump and a reddish clump in B-R color. Nonparametric statistical tests show no significant difference between the B-R color distribution of the inner disk objects compared to the color distributions of Centaurs, plutinos, or scattered disk objects. However, the B-R color distribution of the inner classical Kuiper Belt Objects does differ significantly from the distribution of colors in the cold (low inclination) main classical Kuiper Belt. The cold main classical objects are predominately red, while the inner classical belt objects are a mixture of neutral and red. The color difference may reveal the existence of a gradient in the composition and/or surface processing history in the primordial Kuiper Belt, or indicate that the inner disk objects are not dynamically analogous to the cold main classical belt objects.

  19. The color of the Kuiper belt Core

    NASA Astrophysics Data System (ADS)

    Gulbis, Amanda A. S.; Elliot, J. L.; Kane, Julia F.

    2006-07-01

    Recent dynamical analyses of the Kuiper belt have introduced a rigorous classification scheme, determined the mean orbital plane, and identified "Core" and "Halo" populations as a function of inclination with respect to this plane (Elliot, J.L., Kern, S.D., Clancy, K.B., Gulbis, A.A.S., Millis, R.L., Buie, M.W., Wasserman, L.H., Chiang, E.I., Jordan, A.B., Trilling, D.E., Meech, K.J., 2005. Astron. J. 129, 1117-1162). Here, we use new observations and existing data to investigate the colors of Kuiper belt objects (KBOs) within this framework. With respect to the bulk KBO color distribution (all objects for which we have B-V and V-R colors; median B-R=1.56), we find that the population of objects classified following (Elliot, J.L., Kern, S.D., Clancy, K.B., Gulbis, A.A.S., Millis, R.L., Buie, M.W., Wasserman, L.H., Chiang, E.I., Jordan, A.B., Trilling, D.E., Meech, K.J., 2005. Astron. J. 129, 1117-1162) as Classical tends to be red ( B-R>1.56) while the Scattered Near population is mostly neutral ( B-R<1.56). Colors of Scattered Extended and Resonant objects are consistent with the bulk distribution. Separating objects into specific resonances demonstrates that the color of the Resonant sample is dominated by KBOs in the 3:2 resonance, which is consistent with previous findings. Unlike the objects in the 3:2 resonance, however, the majority of objects in the 5:2 resonance are neutral and all but one of the objects in the 4:3, 5:3, 7:4, 2:1, and 7:3 resonances are red. In particular, the objects in the 7:4 resonance are remarkably red. We find that the colors of KBOs in the Core (low-inclination) and Halo (high-inclination) are statistically different, with Core objects being primarily red and Halo objects having a slight tendency to be neutral. Notably, virtually all of the non-Resonant Core objects are red. This combination of low inclination, unperturbed orbits and red colors in the Core may be indicative of a relic grouping of objects.

  20. 20 CFR 665.100 - What are the Statewide workforce investment activities under title I of WIA?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false What are the Statewide workforce investment activities under title I of WIA? 665.100 Section 665.100 Employees' Benefits EMPLOYMENT AND TRAINING... training activities for adults and dislocated workers, as described in WIA section 134(a), and...

  1. 20 CFR 665.100 - What are the Statewide workforce investment activities under title I of WIA?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What are the Statewide workforce investment activities under title I of WIA? 665.100 Section 665.100 Employees' Benefits EMPLOYMENT AND TRAINING... title I of WIA? Statewide workforce investment activities include Statewide employment and...

  2. Chiron and the Centaurs: Escapees from the Kuiper Belt

    NASA Technical Reports Server (NTRS)

    Stern, Alan; Campins, Humberto

    1996-01-01

    The outer Solar System has long appeared to be a largely empty place, inhabited only by the four giant planets, Pluto and a transient population of comets. In 1977 however, a faint and enigmatic object - 2060 Chiron - was discovered moving on a moderately inclined, strongly chaotic 51-year orbit which takes it from just inside Saturn's orbit out almost as far as that of Uranus. It was not initially clear from where Chiron originated. these objects become temporarily trapped on Centaur-like orbits Following Chiron's discovery, almost 15 years elapsed before other similar objects were discovered; five more have now been identified. Based on the detection statistics implied by these discoveries, it has become clear that these objects belong to a significant population of several hundred (or possibly several thousand) large icy bodies moving on relatively short-lived orbits between the giant planets. This new class of objects, known collectively as the Centaurs, are intermediate in diameter between typical comets (1-20 km) and small icy planets such as Pluto (approx. 2,300 km) and Triton (approx. 2,700 km). Although the Centaurs are interesting in their own right, they have taken on added significance following the recognition that they most probably originated in the ancient reservoir of comets and larger objects located beyond the orbit of Neptune known as the Kuiper belt.

  3. A Possible Icy Kuiper Belt around HD 181327

    NASA Astrophysics Data System (ADS)

    Chen, Christine H.; Fitzgerald, Michael P.; Smith, Paul S.

    2008-12-01

    We have obtained a Gemini South T-ReCS Qa-band (18.3 μm) image and a Spitzer MIPS SED-mode observation of HD 181327, an F5/F6 V member of the ~12 Myr old β Pictoris moving group. We resolve the disk in thermal emission for the first time and find that the northern arm of the disk is 1.4 times brighter than the southern arm. In addition, we detect a broad peak in the combined Spitzer IRS and MIPS spectra at 60-75 μm that may be produced by emission from crystalline water ice. We model the IRS and MIPS data using a size distribution of amorphous olivine and water ice grains (dn/da propto a-2.25, with amin consistent with the minimum blowout size and amax = 20 μm) located at a distance of 86.3 AU from the central star, as observed in previously published scattered-light images. Since the photodesorption lifetime for the icy particles is ~1400 yr, significantly less than the estimated ~12 Myr age of the system, we hypothesize that we have detected debris that may be steadily replenished by collisions among icy Kuiper Belt object-like parent bodies in a newly forming planetary system.

  4. 20 CFR 10.0 - What are the provisions of the FECA, in general?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... general? 10.0 Section 10.0 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF... the payment of workers' compensation benefits to civilian officers and employees of all branches of... benefits, including compensation for wage loss, schedule awards, medical and related benefits, and...

  5. High-Latitude Ionospheric Structuring at Kilometer Scales

    NASA Astrophysics Data System (ADS)

    Bust, G. S.; Datta-Barua, S.; Su, Y.; Deshpande, K.; Hampton, D.

    2014-12-01

    Ionospheric observations in the polar and auroral zones have been made regularly with radar chains and optical imaging at larger spatio-temporal cadence. However, the observation of kilometer scale variations at sub-second cadence has not been practically realizable until recently. Quantifying the irregularities at these sizes and scales is necessary for an understanding of the dynamics leading to fine scale phenomena in the high latitude environment. We present measurements of kilometer-scale plasma variations made at the northern auroral zone using an array of specialized Global Positioning System (GPS) receivers. These 6 CASES receivers (plus 1 from ASTRA, LLC) are sited at the Poker Flat Research Range, Alaska, and have been collecting data since late 2013. The array monitors for ionospheric scintillations, fluctuations in phase and amplitude of the GPS L-band signals received due to ionospheric variations. The array spans 2 km east-west and about 1 km north-south, with a variety of intermediate baseline lengths down to about 200 m. In addition to measuring amplitude and phase scintillation with the S4 and sigma_phi indices at 100-s cadence, these receivers also record 100 Hz raw power and phase measurements from GPS baseband signal processing. These low-rate data are publicly available for download through a web portal at http://apollo.tbc.iit.edu/~spaceweather/ with high rate available upon request. A detailed case study is presented from the December 8, 2013, 0300-0400 UT time period. During this period several interesting scintillation periods were observed. We use array cross-correlation processing methods to first estimate direct ground parameters of the array including a) estimate the 2D drift velocity on the ground; b) estimate a de-correlation (or turbulent) speed; and c) parameters of correlation elliptical coordinates (axial ratio and tilt angle). We then use these results and cross-correlation measurements to derive the ground 2D spatial spectrum of

  6. Detection of Small Kuiper Belt Objects by Stellar Occultation

    NASA Astrophysics Data System (ADS)

    Georgevits, George

    2006-09-01

    We present here the results for the first attempt to survey the sub-kilometre radius KBO population by stellar occultation. Using the unique capabilities of the 1.2m UK Schmidt Telescope (Anglo Australian Observatory, Australia), in conjunction with the 6df Spectrograph, by simultaneously monitoring 100 suitably selected stars, we were able to embark upon an occultation observation program which yielded 7,000 hours of stellar light curves, with 10 millisecond resolution. Initial data reduction indicates that we have captured many events which resemble occultation events, in so far as the light curves of recorded events typically match that which may be expected when a small KBO occults a distant star. Logged events are spread over many pixels, with 10 pixels (corresponding to 100 milliseconds) being the typical event duration. By simultaneously monitoring many stars in the same field, false events are eliminated. Most runs monitored blue stars located at 2kpcs. As a sanity check, one night's observing monitored close F and G class stars in the same field. The event statistics for the distant and the close star cases are consistent with occultations caused by KBO's. As an additional confirmation, it was found that the observation results at 30o and 60o past opposition give the expected 50% fall in event rate due to the change in observing geometry. It is estimated that many of the events logged correspond to occultations which would be caused by objects down to 300m radius. As the next step, it is hoped to construct a purpose-built 2,000 fibre instrument and to conduct a complete survey of the Kuiper Belt. We wish to express our thanks to the Anglo Australian Observatory for their technical assistance and telescope time.

  7. USING KUIPER BELT BINARIES TO CONSTRAIN NEPTUNE'S MIGRATION HISTORY

    SciTech Connect

    Murray-Clay, Ruth A.; Schlichting, Hilke E.

    2011-04-01

    Approximately 10%-20% of all Kuiper Belt objects (KBOs) occupy mean-motion resonances with Neptune. This dynamical configuration likely resulted from resonance capture as Neptune migrated outward during the late stages of planet formation. The details of Neptune's planetesimal-driven migration, including its radial extent and the concurrent eccentricity evolution of the planet, are the subject of considerable debate. Two qualitatively different proposals for resonance capture have been proposed-migration-induced capture driven by smooth outward evolution of Neptune's orbit and chaotic capture driven by damping of the planet's eccentricity near its current semi-major axis. We demonstrate that the distribution of comparable-mass, wide-separation binaries occupying resonant orbits can differentiate between these two scenarios. If migration-induced capture occurred, this fraction records information about the formation locations of different populations of KBOs. Chaotic capture, in contrast, randomizes the orbits of bodies as they are placed in resonance. In particular, if KBO binaries are formed by dynamical capture in a protoplanetary disk with a surface mass density typical of observed extrasolar disks, then migration-induced capture produces the following signatures. The 2:1 resonance should contain a dynamically cold component, with inclinations less than 5{sup 0}-10{sup 0}, having a binary fraction comparable to that among cold classical KBOs. If the 3:2 resonance also hosts a cold component, its binary fraction should be 20%-30% lower than in the cold classical belt. Among cold 2:1 (and if present 3:2) KBOs, objects with eccentricities e < 0.2 should have a binary fraction {approx}20% larger than those with e>0.2. Other binary formation scenarios and disk surface density profiles can generate analogous signatures but produce quantitatively different results. Searches for cold components in the binary fractions of resonant KBOs are currently practical. The

  8. A comparative structural and magnetic study of Fe100-xPdx(x=15, 20 and 36) thin films deposited on Si (100) and glass substrates

    NASA Astrophysics Data System (ADS)

    Bahamida, S.; Fnidiki, A.; Laggoun, A.; Guittoum, A.

    2015-10-01

    Various structural and magnetic characterization techniques have been used to investigate Fe100-xPdx (x=15, 20 and 36) thin films deposited onto silicon and glass substrates, by thermal evaporation technique. X-ray diffraction analysis shows the presence of supersaturated solid solution with bcc structure for Pd concentrations of 15% and 20%. However, for 36% of Pd, in addition to the supersaturated α-FePd (bcc) phase, another disordered FePd3 phase with fcc structure is present. At 20 at% Pd, the magnetic characterization shows a saturation of the bcc (α-FePd) phase and the appearance of the fcc phase. The correlation between the structure and magnetic properties allows us to compare the two substrates effects on deposited thin films. As results, the measurements indicate that the grain size D, the thin film thickness and the d(110) spacing significantly affect the magnetic coercivity HC. The Fe-Pd alloys deposited on a monocrystalline Si (100) and glass substrate show that the coercivity HC is given by the random anisotropy model.

  9. Observing the Extragalactic Universe with a Square Kilometer Array

    NASA Astrophysics Data System (ADS)

    Blandford, R. D.

    2001-12-01

    The Square Kilometer Array, SKA, is being developed to provide broad, radio survey capability to cm wavelength, with a 1 degree field of view, 1 arcsec resolution and 100 times the VLA sensitivity. In extragalactic astronomy, it will observe unobscured, normal and active galaxies, star formation and mergers, large scale structure and gravitational lenses throughout the universe. It will contribute mightily to our emerging, empirical description of the birth and growth of galaxies of all type. It should also advance our understanding of the conditions that existed prior to galaxy formation at the end of the dark age and help delineate the dark matter skeleton that supports mature galaxies. It will map and monitor, in quite different modes, the same objects as Chandra, SIRTF, HST/ACS, GLAST, SDSS as well as future missions like NGST and Constellation-X. The proposed scientific capability of SKA will be summarized. In addition, the importance of refining its goals and design criteria in a dialog with organizations making complementary plans throughout the electromagnetic spectrum will be emphasized.

  10. Analysis of the sequential fission observed in collisions of100Mo +100Mo and120Sn +120Sn around 20 A·MeV

    NASA Astrophysics Data System (ADS)

    Stefanini, A. A.; Casini, G.; Maurenzig, P. R.; Olmi, A.; Charity, R. J.; Freifelder, R.; Gobbi, A.; Herrmann, N.; Hildenbrand, K. D.; Petrovici, M.; Rami, F.; Stelzer, H.; Wessels, J. P.; Gnirs, M.; Pelte, D.; Galin, J.; Guerreau, D.; Jahnke, U.; Péghaire, A.; Adloff, J. C.; Bilwes, B.; Bilwes, R.; Rudolf, G.

    1995-06-01

    Events with 2, 3 and 4 heavy fragments (A≥20) detected in the reactions100Mo +100Mo at 18.7, 23.7 A·MeV and120Sn +120Sn at 18.4 A·MeV were analyzed by means of an improved version of the kinematic coincidence method. The phase-space distributions prove that 3- (and possibly 4-) body events predominantly originate from a two-step mechanism and are compatible with the hypothesis of a binary deep-inelastic interaction followed by the further fissionlike decay of one (or both) of the primary fragments. The characteristics of the fission step — mass asymmetry, relative velocity, in-plane and out-of-plane angles — have been reconstructed for the 3-body events and indications are found that nonequilibrium effects at the end of the deep-inelastic phase may influence the fissionlike decay.

  11. Neptune's eccentricity and the nature of the kuiper belt

    PubMed

    Ward; Hahn

    1998-06-26

    The small eccentricity of Neptune may be a direct consequence of apsidal wave interaction with the trans-Neptune population of debris called the Kuiper belt. The Kuiper belt is subject to resonant perturbations from Neptune, so that the transport of angular momentum by density waves can result in orbital evolution of Neptune as well as changes in the structure of the Kuiper belt. In particular, for a belt eroded out to the vicinity of Neptune's 2:1 resonance at about 48 astronomical units, Neptune's eccentricity can damp to its current value over the age of the solar system if the belt contains slightly more than an earth mass of material out to about 75 astronomical units.

  12. Neptune's Eccentricity and the Nature of the Kuiper Belt

    NASA Technical Reports Server (NTRS)

    Ward, William R.; Hahn, Joseph M.

    1998-01-01

    The small eccentricity of Neptune may be a direct consequence of apsidal wave interaction with the trans-Neptune population of debris called the Kuiper belt. The Kuiper belt is subject to resonant perturbations from Neptune, so that the transport of angular momentum by density waves can result in orbital evolution of Neptune as well as changes in the structure of the Kuiper belt. In particular, for a belt eroded out to the vicinity of Neptune's 2:1 resonance at about 48 astronomical units, Neptune's eccentricity can damp to its current value over the age of the solar system if the belt contains slightly more than an earth mass of material out to about 75 astronomical units.

  13. The Color of the Kuiper-Belt Core

    NASA Astrophysics Data System (ADS)

    Gulbis, A. A. S.; Elliot, J. L.; Kane, J. F.

    2004-11-01

    The Kuiper belt is thought to be the least thermally modified region in the Solar System and thus provides unique insight into its formation and evolution. Subsets of Kuiper belt objects (KBOs) can be distinguished by correlations between dynamical characteristics and physical properties. This may lead to the identification of a grouping of objects that have undergone minimal processing and are representative of primitive material. Using recent results from the Deep Ecliptic Survey (DES), in which the plane of the Kuiper belt has been calculated (see the abstract by Elliot et al.), we search for correlations between KBO dynamical properties and colors. As a function of inclination with respect to the Kuiper-belt plane, there are distinct ``core" and ``halo" populations -- similar to the hot and cold populations proposed by others (e.g. Brown Astron. J. 121, 2804, 2001; Levison & Stern Astron. J. 121, 1730, 2001). The core objects are represented by a strong peak in object poles located within a few degrees of the pole of the Kuiper-belt plane, while the halo objects have a shallower distribution extending to inclinations beyond 30o. We use previously published data, along with new observations from the 6.5-m Clay telescope at Las Campanas Observatory, to investigate the colors of the core KBOs. We find that non-resonant objects having inclinations less than approximately 1.2o from the Kuiper-belt plane are distinctly redder than the general population. Correlations between color and perihelion distance, and color and inclination for ``Classical" KBOs, have been previously noted (e.g. Tegler et al. Astrophys. J. 599, L49, 2003; Trujillo & Brown Astrophys. J. 566, L125, 2002). However, the core sample contains ``Scattered" objects with low perihelion distances (q < 40) and high eccentricities. Funding for this research is provided by NASA Grant NAG04GF25G and NSF Grant AST-0073447.

  14. ARTIST'S VIEW OF KUIPER BELT OBJECT 1998 WW31

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is an artist's view of a Kuiper Belt binary object, called 1998 WW31. These icy bodies orbit each other at the fringe of our solar system. The illustration depicts one member of the duo in the foreground; its companion - the dark, round object - is in the background. The objects are about the same size. Both are illuminated from behind by the Sun [the white dot at upper left]. Like other Kuiper Belt objects, this duo orbits the Sun, completing a circuit every 301 years. The planet Pluto orbits the Sun every 248 years. Credit: NASA and G. Bacon (Space Telescope Science Institute)

  15. Kuiper Belt Objects Along the Pluto Express Path

    NASA Technical Reports Server (NTRS)

    Jewitt, David C.

    1998-01-01

    The science objective of this work was to identify objects in the Kuiper Belt which will, in the 5 years following Pluto encounter, be close to the flight path of NASA's Pluto-Kuiper Express. Currently, launch is scheduled for 2004 with a flight time of about 1 decade. Early identification of post-Pluto targets is important for mission design and orbit refinement. An object or objects close enough to the flight path can be visited and studied at high resolution, using only residual gas in the thrusters to affect a close encounter.

  16. Kuiper Belt Objects Along the Pluto Express Path

    NASA Technical Reports Server (NTRS)

    Jewitt, David C.

    1998-01-01

    The science objective of this work was to identify objects in the Kuiper Belt which will, in the 5 years following Pluto encounter, be close to the flight path of NASA's Pluto-Kuiper Express. Currently, launch is scheduled for 2004 with a flight time of about 1 decade. Early identification of post-Pluto targets is important for mission design and orbit refinement. An object or objects close enough to the flight path can be visited and studied at high resolution, using only residual gas in the thrusters to affect a close encounter.

  17. FORMATION OF KUIPER BELT BINARIES BY GRAVITATIONAL COLLAPSE

    SciTech Connect

    Nesvorny, David; Youdin, Andrew N.; Richardson, Derek C.

    2010-09-15

    A large fraction of {approx}100 km class low-inclination objects in the classical Kuiper Belt (KB) are binaries with comparable masses and a wide separation of components. A favored model for their formation is that they were captured during the coagulation growth of bodies in the early KB. However, recent studies have suggested that large, {approx}>100 km objects can rapidly form in the protoplanetary disks when swarms of locally concentrated solids collapse under their own gravity. Here, we examine the possibility that KB binaries formed during gravitational collapse when the excess of angular momentum prevented the agglomeration of available mass into a solitary object. We find that this new mechanism provides a robust path toward the formation of KB binaries with observed properties, and can explain wide systems such as 2001 QW{sub 322} and multiples such as (47171) 1999 TC{sub 36}. Notably, the gravitational collapse is capable of producing {approx}100% binary fraction for a wide range of the swarm's initial angular momentum values. The binary components have similar masses ({approx}80% have a secondary-over-primary radius ratio >0.7) and their separation ranges from {approx}1000 to {approx}100,000 km. The binary orbits have eccentricities from e = 0 to {approx}1, with the majority having e < 0.6. The binary orbit inclinations with respect to the initial angular momentum of the swarm range from i = 0 to {approx}90{sup 0}, with most cases having i < 50{sup 0}. The total binary mass represents a characteristic fraction of the collapsing swarm's total initial mass, M{sub tot}, suggesting M{sub tot} equivalent to that of a radius {approx}100-250 km compact object. Our binary formation mechanism also implies that the primary and secondary components in each binary pair should have identical bulk composition, which is consistent with the current photometric data. We discuss the applicability of our results to the Pluto-Charon, Orcus-Vanth, (617) Patroclus

  18. 20 CFR 627.100 - Scope and purpose of this part 627.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Section 627.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR GENERAL... titles I, II, and III of the Job Training Partnership Act. (b) Subpart B provides general program... generating activities. This subpart also sets forth comprehensive rules for on-the-job training for JTPA...

  19. 20 CFR 655.100 - Scope and purpose of subpart B.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... out the procedures established by the Secretary of the United States Department of Labor (the... Section 655.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Temporary Agricultural...

  20. 20 CFR 670.100 - What is the scope of this part?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... by the Secretary” refer to the Policy and Requirements Handbook and other Job Corps directives. ... Section 670.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR THE JOB... this part? The regulations in this part are an outline of the requirements that apply to the Job...

  1. 20 CFR 670.100 - What is the scope of this part?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) THE JOB CORPS UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Scope and Purpose § 670.100 What is the scope of this part? The regulations in this part are an outline of the requirements that apply to the Job Corps program. More detailed policies and procedures are contained in a Policy and...

  2. 20 CFR 670.100 - What is the scope of this part?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) THE JOB CORPS UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Scope and Purpose § 670.100 What is the scope of this part? The regulations in this part are an outline of the requirements that apply to the Job Corps program. More detailed policies and procedures are contained in a Policy and...

  3. 20 CFR 670.100 - What is the scope of this part?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... this part? The regulations in this part are an outline of the requirements that apply to the Job Corps... Section 670.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR THE JOB... by the Secretary” refer to the Policy and Requirements Handbook and other Job Corps directives....

  4. 20 CFR 662.100 - What is the One-Stop delivery system?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... investment, educational, and other human resource programs and funding streams (referred to as One-Stop... Section 662.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR... maintenance of a One-Stop delivery system that enhances the range and quality of workforce development...

  5. Cold Disks around Nearby Stars. A Search for Edgeworth-Kuiper Belt Analogues

    NASA Astrophysics Data System (ADS)

    Eiroa, Carlos

    DUNES (DUst disks around NEarby Stars) is a sensitivity-limited survey programme taking advantage of the unique capabilities of Herschel to detect and characterize with cold disks as faint as Ldust/Lstar 10-6 and temperatures of the order of 30 - 40K, i.e., faint exo-solar analogues to the Edgeworth-Kuiper Belt. DUNES will observe a statistically significant, volume limit 20pc)sample, only constrained by background confusion, of 133 FGK nearby stars. No further biases limit the planets and/or Spitzer-discovered faint debris disks up to larger distances, d < 25pc, are also included in the sample.

  6. Venus - 600 Kilometer Segment of Longest Channel on Venus

    NASA Image and Video Library

    1996-03-13

    This compressed resolution radar mosaic from NASA Magellan spacecraft shows a 600 kilometers 360 mile segment of the longest channel discovered on Venus in 1990. http://photojournal.jpl.nasa.gov/catalog/PIA00245

  7. Physiological and cognitive military related performances after 10-kilometer march.

    PubMed

    Yanovich, Ran; Hadid, Amir; Erlich, Tomer; Moran, Daniel S; Heled, Yuval

    2015-01-01

    Prior operational activities such as marching in diverse environments, with heavy backloads may cause early fatigue and reduce the unit's readiness. The purpose of this preliminary study was to evaluate the effect of 10-kilometer (km) march on selected, military oriented, physiological and cognitive performances. Eight healthy young males (age 25 ± 3 years) performed a series of cognitive and physiological tests, first without any prior physiological strain and then after a 10 km march in comfort laboratory conditions (24°C, 50%RH) consisting a 5 km/h speed and 2-6% incline with backload weighing 30% of their body weight. We found that the subjects' time to exhaustion (TTE) after the march decreased by 27% with no changes in anaerobic performance. Cognitive performance showed a significant (20%) reduction in accuracy and a tendency to reduce reaction time after the march. We conclude that a moderate-intensity march under relatively comfort environmental conditions may differently decrease selected military related physical and cognitive abilities. This phenomenon is probably associated with the type and intensity of the pre-mission physical activity and the magnitude of the associated mental fatigue. We suggest that quantifying these effects, as was presented in this preliminary study, by adopting this practical scientific approach would assist in preserving the soldiers' performance and health during training and military operations.

  8. Spectrophotometry of Kuiper Belt Objects and Centaurs

    NASA Astrophysics Data System (ADS)

    Lederer, S. M.; Vilas, F.

    2002-09-01

    We present an ongoing study of Kuiper Belt Objects (KBOs) and Centaurs. We acquired broadband (UBVRI) and medium band photometry with the 4m Mayall telescope at Kitt Peak and the 1.8m Perkins telescope at Lowell Observatory. We present broadband colors of these objects and discuss the results of our search for absorption bands in the visible spectral region. Vilas (Icarus, 111) demonstrated that the existence of the 0.7um absorption feature in asteroids with solar-like colors was strongly correlated with the presence of the 3.0um water of hydration feature. The broad 0.7um absorption band is attributed to a charge-transfer in Fe-bearing hydrated silicates (phyllosilicates), which are a product of aqueous alteration. For aqueous alteration to take place, one must have water ice present in an object, and an energy source to heat the water ice to a liquid water phase. Water ice has already been discovered in some Centaurs (Luu et al. ApJ, 531; Brown AJ, 119), and Durda and Stern (Icarus, 145) estimate that KBOs experience collisional processing regularly throughout their lifetimes. The estimated impact energies are high enough to induce aqueous alteration. We undertook this study to search for evidence of the 0.7um feature in KBOs and Centaurs. We employed medium band Windhorst filters, located at 0.527, 0.666, 0.705, 0.755 and 0.848 um in conjunction with the Mosaic CCD to search for this absorption band, which extends from 0.57-0.83um. Initial analysis suggests that an absorption feature exists near 0.7um in the greyer objects but not the redder objects, following the correlations observed in asteroids. These data are consistent with the absorption band detected near 0.7um by de Bergh et al. (ACM 2002, Berlin) in visible spectra of 2000 EB173 and 2000 GN171. However, further analysis is required to confirm whether the absorption we see is due to phyllosilicates or another source. We will present the results from this analysis. This research was supported through the

  9. [Statistical analysis of 100 cases of allergic rhinitis in the "20 de Noviembre" regional hospital. ISSSTE].

    PubMed

    Mondragón Pineda, M E

    1990-01-01

    We analyzed 100 patients with allergic rhinitis during a twelve month period. Youngsters represented 59% of the population. There was no sex predominance. 69% of the patients had a positive history of familial atopy and relation with other allergic condition was found in 74%. The nasal eosinophilia and skin tests were important diagnostic tools, not being necessary the measurement of IgE in plasma. Immunotherapy was effective in 88% of the patients.

  10. NEP for a Kuiper Belt Object Rendezvous Mission

    SciTech Connect

    HOUTS,MICHAEL G.; LENARD,ROGER X.; LIPINSKI,RONALD J.; PATTON,BRUCE; POSTON,DAVID I.; WRIGHT,STEVEN A.

    1999-11-03

    Kuiper Belt Objects (KBOs) are a recently-discovered set of solar system bodies which lie at about the orbit of Pluto (40 AU) out to about 100 astronomical units (AU). There are estimated to be about 100,000 KBOS with a diameter greater than 100 km. KBOS are postulated to be composed of the pristine material which formed our solar system and may even have organic materials in them. A detailed study of KBO size, orbit distribution, structure, and surface composition could shed light on the origins of the solar system and perhaps even on the origin of life in our solar system. A rendezvous mission including a lander would be needed to perform chemical analysis of the surface and sub-surface composition of KBOS. These requirements set the size of the science probe at around a ton. Mission analyses show that a fission-powered system with an electric thruster could rendezvous at 40 AU in about 13.0 years with a total {Delta}V of 46 krnk. It would deliver a 1000-kg science payload while providing ample onboard power for relaying data back to earth. The launch mass of the entire system (power, thrusters, propellant, navigation, communication, structure, science payload, etc.) would be 7984 kg if it were placed into an earth-escape trajectory (C=O). Alternatively, the system could be placed into a 700-km earth orbit with more propellant,yielding a total mass in LEO of 8618 kg, and then spiral out of earth orbit to arrive at the KBO in 14.3 years. To achieve this performance, a fission power system with 100 kW of electrical power and a total mass (reactor, shield, conversion, and radiator) of about 2350 kg. Three possible configurations are proposed: (1) a UZrH-fueled, NaK-cooled reactor with a steam Rankine conversion system, (2) a UN-fueled gas-cooled reactor with a recuperated Brayton conversion system, and (3) a UN-fueled heatpipe-cooled reactor with a recuperated Brayton conversion system. (Boiling and condensation in the Rankine system is a technical risk at present

  11. 21 CFR 20.100 - Applicability; cross-reference to other regulations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... file for an antibiotic drug, in § 514.10 of this chapter. (13) Methadone patient records, in § 291.505... chapter. (20) Investigational new drug notice for an antibiotic drug, in § 431.70 of this chapter. (21) Antibiotic drug file, in § 314.430 of this chapter. (22) Data and information submitted for biologics...

  12. 21 CFR 20.100 - Applicability; cross-reference to other regulations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... file for an antibiotic drug, in § 514.10 of this chapter. (13) Methadone patient records, in § 291.505... chapter. (20) Investigational new drug notice for an antibiotic drug, in § 431.70 of this chapter. (21) Antibiotic drug file, in § 314.430 of this chapter. (22) Data and information submitted for biologics...

  13. 21 CFR 20.100 - Applicability; cross-reference to other regulations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... file for an antibiotic drug, in § 514.10 of this chapter. (13) Methadone patient records, in § 291.505... chapter. (20) Investigational new drug notice for an antibiotic drug, in § 431.70 of this chapter. (21) Antibiotic drug file, in § 314.430 of this chapter. (22) Data and information submitted for biologics...

  14. 21 CFR 20.100 - Applicability; cross-reference to other regulations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... file for an antibiotic drug, in § 514.10 of this chapter. (13) Methadone patient records, in § 291.505... chapter. (20) Investigational new drug notice for an antibiotic drug, in § 431.70 of this chapter. (21) Antibiotic drug file, in § 314.430 of this chapter. (22) Data and information submitted for biologics review...

  15. 20 CFR 403.100 - When can an SSA employee testify or produce information or records in legal proceedings?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false When can an SSA employee testify or produce....100 When can an SSA employee testify or produce information or records in legal proceedings? An SSA employee can testify concerning any function of SSA or any information or record created or acquired by SSA...

  16. 20 CFR 403.100 - When can an SSA employee testify or produce information or records in legal proceedings?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false When can an SSA employee testify or produce....100 When can an SSA employee testify or produce information or records in legal proceedings? An SSA employee can testify concerning any function of SSA or any information or record created or acquired by SSA...

  17. 20 CFR 403.100 - When can an SSA employee testify or produce information or records in legal proceedings?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false When can an SSA employee testify or produce....100 When can an SSA employee testify or produce information or records in legal proceedings? An SSA employee can testify concerning any function of SSA or any information or record created or acquired by SSA...

  18. 20 CFR 403.100 - When can an SSA employee testify or produce information or records in legal proceedings?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false When can an SSA employee testify or produce....100 When can an SSA employee testify or produce information or records in legal proceedings? An SSA employee can testify concerning any function of SSA or any information or record created or acquired by SSA...

  19. 20 CFR 403.100 - When can an SSA employee testify or produce information or records in legal proceedings?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false When can an SSA employee testify or produce....100 When can an SSA employee testify or produce information or records in legal proceedings? An SSA employee can testify concerning any function of SSA or any information or record created or acquired by SSA...

  20. Layered Model for Radiation-Induced Chemical Evolution of Icy Surface Composition on Kuiper Belt and Oort Cloud Bodies

    NASA Technical Reports Server (NTRS)

    Cooper, John F.; Hill, Matthew E.; Richardson, John D.; Sturner, Steven J.

    2010-01-01

    The diversity of albedos and surface colors on observed Kuiper Belt and Inner Oort Cloud objects remains to be explained in terms of competition between primordial intrinsic versus exogenic drivers of surface and near-surface evolution. Earlier models have attempted without success to attribute this diversity to the relations between surface radiolysis from cosmic ray irradiation and gardening by meteoritic impacts. A more flexible approach considers the different depth-dependent radiation profiles produced by low-energy plasma, suprathermal, and maximally penetrating charged particles of the heliospheric and local interstellar radiation environments. Generally red objects of the dynamically cold (low inclination, circular orbit) Classical Kuiper Belt might be accounted for from erosive effects of plasma ions and reddening effects of high energy cosmic ray ions, while suprathermal keV-MeV ions could alternatively produce more color neutral surfaces. The deepest layer of more pristine ice can be brought to the surface from meter to kilometer depths by larger impact events and potentially by cryovolcanic activity. The bright surfaces of some larger objects, e.g. Eris, suggest ongoing resurfacing activity. Interactions of surface irradiation, resultant chemical oxidation, and near-surface cryogenic fluid reservoirs have been proposed to account for Enceladus cryovolcanism and may have further applications to other icy irradiated bodies. The diversity of causative processes must be understood to account for observationally apparent diversities of the object surfaces.

  1. Size and Albedo of the Kuiper Belt Object 55636

    NASA Astrophysics Data System (ADS)

    Elliot, James L.; Person, M. J.; Zuluaga, C. A.; Bosh, A. S.; Adams, E. R.; Brothers, T. C.; Gulbis, A. A. S.; Levine, S. E.; Lockhart, M.; Zangari, A. M.; Babcock, B. A.; DuPré, K.; Pasachoff, J. M.; Souza, S. P.; Rosing, W.; Secrest, N.

    2010-10-01

    Due to the small sizes and great distances of Kuiper belt objects (KBOs), it is difficult to determine their diameters. We report multi-chord observations of a KBO stellar occultation, which occurred on 2009 October 9 (Elliot, J. L., et al. 2010, Nature, 465, 897). We set up a network of 21 telescopes at 18 stations, spanning a distance of 5920 km perpendicular to the predicted shadow path for the 2009 October 9 stellar occultation by the KBO 55636. Of these stations, seven could not observe due to weather, nine reported non-detections, and two observed an occultation, both in Hawai'i: the 2.0-m Faulkes North telescope at Haleakala and a 0.36-m portable telescope at the Visitor Information Station at the Onizuka Center for International Astronomy on Mauna Kea (located at the Mauna Kea Mid Level). We find that 55636 (2002 TX300), which is a member of the water-ice rich Haumea KBO collisional family (Brown, M. E., et al. 2007, Nature, 446, 294), has a mean radius of 143 ± 5 km (for a circular solution). Allowing for possible elliptical shapes we find a geometric albedo of 0.88 +0.15/-0.06 in the V photometric band. This firmly establishes that 55636 is smaller than previously thought and like its parent body, Haumea, is among the most highly reflective objects in the Solar System. Dynamical calculations by two groups indicate that the collision that created 55636 occurred at least 1 Gyr ago (Ragozzine, D., & Brown, M. E. 2007, AJ, 134, 2160; Schlichting, H. E., & Sari, R. 2009, ApJ, 700, 1242), which implies either that 55636 has an active resurfacing mechanism, or that fresh water ice in the outer solar system can persist for Gyr timescales. This work was supported, in part by NASA Grants NNX10AB27G (MIT), NNX08AO50G (Williams College), and NNH08AI17I (USNO-FS).

  2. All planetesimals born near the Kuiper belt formed as binaries

    NASA Astrophysics Data System (ADS)

    Fraser, Wesley C.; Bannister, Michele T.; Pike, Rosemary E.; Marsset, Michael; Schwamb, Megan E.; Kavelaars, J. J.; Lacerda, Pedro; Nesvorný, David; Volk, Kathryn; Delsanti, Audrey; Benecchi, Susan; Lehner, Matthew J.; Noll, Keith; Gladman, Brett; Petit, Jean-Marc; Gwyn, Stephen; Chen, Ying-Tung; Wang, Shiang-Yu; Alexandersen, Mike; Burdullis, Todd; Sheppard, Scott; Trujillo, Chad

    2017-04-01

    The cold classical Kuiper belt objects have low inclinations and eccentricities1,2 and are the only Kuiper belt population suspected to have formed in situ3. Compared with the dynamically excited populations, which exhibit a broad range of colours and a low binary fraction of ∼10%4 cold classical Kuiper belt objects typically have red optical colours5 with ∼30% of the population found in binary pairs6; the origin of these differences remains unclear7,8. We report the detection of a population of blue-coloured, tenuously bound binaries residing among the cold classical Kuiper belt objects. Here we show that widely separated binaries could have survived push-out into the cold classical region during the early phases of Neptune's migration9. The blue binaries may be contaminants, originating at ∼38 au, and could provide a unique probe of the formative conditions in a region now nearly devoid of objects. The idea that the blue objects, which are predominantly binary, are the products of push-out requires that the planetesimals formed entirely as multiples. Plausible formation routes include planetesimal formation via pebble accretion10 and subsequent binary production through dynamic friction11 and binary formation during the collapse of a cloud of solids12.

  3. Kuipers during replacement of the Marangoni Surface Fluid Dynamics Experiment

    NASA Image and Video Library

    2012-03-15

    ISS030-E-142827 (15 March 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, works to remove the Marangoni Surface fluid physics experiment from the Fluid Physics Experiment Facility (FPEF) in the Kibo laboratory of the International Space Station.

  4. Kuipers works to remove the Marangoni Suface Fluid Physics Experiment

    NASA Image and Video Library

    2012-03-15

    ISS030-E-142785 (15 March 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, works to remove the Marangoni Surface fluid physics experiment from the Fluid Physics Experiment Facility (FPEF) in the Kibo laboratory of the International Space Station.

  5. Kuipers works to remove the Marangoni Suface Fluid Physics Experiment

    NASA Image and Video Library

    2012-03-15

    ISS030-E-142784 (15 March 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, works to remove the Marangoni Surface fluid physics experiment from the Fluid Physics Experiment Facility (FPEF) in the Kibo laboratory of the International Space Station.

  6. Kuipers exercises on teh COL BERT in the Node 3

    NASA Image and Video Library

    2012-01-18

    ISS030-E-049576 (18 Jan. 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, equipped with a bungee harness, exercises on the Combined Operational Load Bearing External Resistance Treadmill (COLBERT) in the Tranquility node of the International Space Station.

  7. The Chemical Composition of an Extrasolar Kuiper-Belt-Object

    NASA Astrophysics Data System (ADS)

    Xu, S.; Zuckerman, B.; Dufour, P.; Young, E. D.; Klein, B.; Jura, M.

    2017-02-01

    The Kuiper Belt of our solar system is a source of short-period comets that may have delivered water and other volatiles to Earth and the other terrestrial planets. However, the distribution of water and other volatiles in extrasolar planetary systems is largely unknown. We report the discovery of an accretion of a Kuiper-Belt-Object analog onto the atmosphere of the white dwarf WD 1425+540. The heavy elements C, N, O, Mg, Si, S, Ca, Fe, and Ni are detected, with nitrogen observed for the first time in extrasolar planetary debris. The nitrogen mass fraction is ∼2%, comparable to that in comet Halley and higher than in any other known solar system object. The lower limit to the accreted mass is ∼1022 g, which is about one hundred thousand times the typical mass of a short-period comet. In addition, WD 1425+540 has a wide binary companion, which could facilitate perturbing a Kuiper-Belt-Object analog into the white dwarf’s tidal radius. This finding shows that analogs to objects in our Kuiper Belt exist around other stars and could be responsible for the delivery of volatiles to terrestrial planets beyond the solar system. Part of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among Caltech, the University of California and NASA. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

  8. Three Classes of Kuiper Belt Objects: Theory and Observations

    NASA Technical Reports Server (NTRS)

    Holman, Mathew J.; Boyce, J. (Technical Monitor)

    2001-01-01

    As part of the Origins of Solar Systems program our team conducted a dynamically motivated search for three classes of Kuiper belt objects (distant comets near and beyond the orbit of Neptune). Our strategy has been to exploit variations in the sky density of Kuiper belt that result from the gravitational influence of Neptune. By searching two regions of the sky, one nearly 90 degrees from Neptune and one nearly opposite Neptune, and comparing the number of objects discovered in each region we are able to constrain the relative populations of resonant and non-resonant objects, a fundamental quantity in Kuiper belt formation models. In addition, by searching at a variety of angles above the plane of the solar system we have constrained the inclination distribution of Kuiper belt objects. We have conducted four searches for this program. One was in February 1999 and August 2000 at the Canada-France-Hawaii telescope (3.6-meter), and another was in May 1999 and Oct. 2000 at the Kitt Peak National Observatory (4-meter). In addition, a search for Uranian satellites was conducted.

  9. Exploration Missions to the Kuiper Belt and Oort Cloud

    NASA Astrophysics Data System (ADS)

    Stern, S. A.; McKinnon, W. B.; Moore, J. M.; Buie, M. W.; Zangari, A.; Spencer, J. R.; Parker, A. H.; McNutt, R. L.

    2017-02-01

    The Kuiper Belt and Oort Cloud offer deep insights into the origin of our solar system and the workings of small planets. The exploration of these regions beckons for new missions exploring new worlds and returning to explore Pluto in more detail.

  10. Kuipers during second orbital NEUROSPAT Session in the Columbus Module

    NASA Image and Video Library

    2012-02-14

    ISS030-E-116907 (13 Feb. 2012) --- Wearing an Electroencephalogram (EEG) electrode cap, European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, performs a NeuroSpat science session in the Columbus laboratory of the International Space Station. NeuroSpat investigates the ways in which crew members’ three-dimensional visual & space perception is affected by long-duration stays in weightlessness.

  11. Kuipers during second orbital NEUROSPAT Session in the Columbus Module

    NASA Image and Video Library

    2012-02-14

    ISS030-E-116908 (13 Feb. 2012) --- Wearing an Electroencephalogram (EEG) electrode cap, European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, performs a NeuroSpat science session in the Columbus laboratory of the International Space Station. NeuroSpat investigates the ways in which crew members’ three-dimensional visual & space perception is affected by long-duration stays in weightlessness.

  12. Kuipers prepares to insert biological samples in the MELFI

    NASA Image and Video Library

    2012-02-09

    ISS030-E-116886 (9 Feb. 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, prepares to insert biological samples in the Minus Eighty Laboratory Freezer for ISS (MELFI-1) in the Kibo laboratory of the International Space Station.

  13. Kuipers works at the MELFI-1 in the JPM

    NASA Image and Video Library

    2011-12-24

    ISS030-E-033272 (24 Dec. 2011) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, prepares to insert ESA Role of Apoptosis in Lymphocyte Depression 2 (ROALD-2) experiment samples into a Minus Eighty Laboratory Freezer for ISS (MELFI-1) dewar tray located in the International Space Station's Kibo laboratory.

  14. Kuipers prepares to insert biological samples in the MELFI

    NASA Image and Video Library

    2012-02-09

    ISS030-E-116879 (9 Feb. 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, prepares to insert biological samples in the Minus Eighty Laboratory Freezer for ISS (MELFI-1) in the Kibo laboratory of the International Space Station.

  15. Kuipers prepares to insert biological samples in the MELFI

    NASA Image and Video Library

    2012-02-09

    ISS030-E-116878 (9 Feb. 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, prepares to insert biological samples in the Minus Eighty Laboratory Freezer for ISS (MELFI-1) in the Kibo laboratory of the International Space Station.

  16. Far-Infrared Astronomy with The Kuiper Airborne Observatory

    NASA Technical Reports Server (NTRS)

    Hildebrand, Roger, H.

    1997-01-01

    This report summarizes work made possible by NASA's Kuiper Airborne Observatory. The results of the work have appeared in over 80 papers. The publications fall in three main areas: instrumentation, observations, and analysis. Although there is considerable overlap between these categories it will be convenient to group them separately.

  17. Pettit and Kuipers in a run of the SPHERES ZR

    NASA Image and Video Library

    2012-01-23

    ISS030-E-047176 (23 Jan. 2012) --- In the International Space Station?s Kibo laboratory, NASA astronaut Don Pettit (left) and European Space Agency astronaut Andre Kuipers, both Expedition 30 flight engineers, support competing students on the ground in a run of the Synchronized Position Hold, Engage, Reorient, Experimental Satellites Zero Robotics (SPHERES ZR) experiment.

  18. The Whipple Mission: Exploring the Kuiper Belt and the Oort Cloud

    NASA Astrophysics Data System (ADS)

    Alcock, C.; Brown, M. E.; Gauron, T.; Heneghan, C.; Holman, M. J.; Kenter, A.; Kraft, R.; Lee, R.; Livingston, J.; Mcguire, J.; Murray, S. S.; Murray-Clay, R.; Nulsen, P.; Payne, M. J.; Schlichting, H.; Trangsrud, A.; Vrtilek, J.; Werner, M.

    2014-12-01

    Whipple will characterize the small body populations of the Kuiper Belt and the Oort Cloud with a blind occultation survey, detecting objects when they briefly (~1 second) interrupt the light from background stars, allowing the detection of much more distant and/or smaller objects than can be seen in reflected sunlight. Whipple will reach much deeper into the unexplored frontier of the outer solar system than any other mission, current or proposed. Whipple will look back to the dawn of the solar system by discovering its most remote bodies where primordial processes left their imprint. Specifically, Whipple will monitor large numbers of stars at high cadences (~12,000 stars at 20 Hz to examine Kuiper Belt events; as many as ~36,000 stars at 5 Hz to explore deep into the Oort Cloud, where events are less frequent). Analysis of the detected events will allow us to determine the size spectrum of bodies in the Kuiper Belt with radii as small as ~1 km. This will allow the testing of models of the growth and later collisional erosion of planetesimals in the early solar system. Whipple will explore the Oort Cloud, detecting objects as far out as ~10,000 AU. This will be the first direct exploration of the Oort Cloud since the original hypothesis of 1950. Whipple is a Discovery class mission that will be proposed to NASA in response to the 2014 Announcement of Opportunity. The mission is being developed jointly by the Smithsonian Astrophysical Observatory, Jet Propulsion Laboratories, and Ball Aerospace & Technologies, with telescope optics from L-3 Integrated Optical Systems.

  19. The Whipple Mission: Exploring the Kuiper Belt and the Oort Cloud

    NASA Astrophysics Data System (ADS)

    Alcock, Charles; Brown, Michael; Gauron, Tom; Heneghan, Cate; Holman, Matthew; Kenter, Almus; Kraft, Ralph; Livingstone, John; Murray-Clay, Ruth; Nulsen, Paul; Payne, Matthew; Schlichting, Hilke; Trangsrud, Amy; Vrtilek, Jan; Werner, Michael

    2015-11-01

    Whipple will characterize the small body populations of the Kuiper Belt and the Oort Cloud with a blind occultation survey, detecting objects when they briefly (~1 second) interrupt the light from background stars, allowing the detection of much more distant and/or smaller objects than can be seen in reflected sunlight. Whipple will reach much deeper into the unexplored frontier of the outer solar system than any other mission, current or proposed. Whipple will look back to the dawn of the solar system by discovering its most remote bodies where primordial processes left their imprint.Specifically, Whipple will monitor large numbers of stars at high cadences (~12,000 stars at 20 Hz to examine Kuiper Belt events; as many as ~36,000 stars at 5 Hz to explore deep into the Oort Cloud, where events are less frequent). Analysis of the detected events will allow us to determine the size spectrum of bodies in the Kuiper Belt with radii as small as ~1 km. This will allow the testing of models of the growth and later collisional erosion of planetesimals in the early solar system. Whipple will explore the Oort Cloud, potentially detecting objects as far out as ~10,000 AU. This will be the first direct exploration of the Oort Cloud since the original hypothesis of 1950.Whipple is a Discovery class mission that was proposed to NASA in response to the 2014 Announcement of Opportunity. The mission is being developed jointly by the Smithsonian Astrophysical Observatory, Jet Propulsion Laboratories, and Ball Aerospace & Technologies, with telescope optics from L-3 Integrated Optical Systems and imaging sensors from Teledyne Imaging Sensors.

  20. Photographer : JPL Range : 312, 000 kilometers (195,000 miles) This photo of Ganymede (Ice Giant)

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Photographer : JPL Range : 312, 000 kilometers (195,000 miles) This photo of Ganymede (Ice Giant) was taken from Voyager 2 and shows features down to about 5 to 6 kilometers across. Different types of terrain common on Ganymede's surface are visible. The boundary of the largest region of dark ancient terrain on Ganymede can be seen to the east (right), revealing some of the light linear features which may be all that remains of a large ancient impact structure similar to the large ring structure on Callisto. The broad light regions running through the image are the typical grooved structures seen within another example of what might be evidence of large scale lateral motion in Ganymede's crust. The band of grooved terrain (about 100 kilometers wide) in this region appears to be offset by 50 kilometers or more on the left hand edge by a linear feature perpendicular to it. A feature similar to this one was previously discovered by Voyager 1. These are the first clear examples of strike-slip style faulting on any planet other than Earth. Many examples of craters of all ages can be seen in this image, ranging from fresh, bright ray craters to large, subdued circular markings thought to be the 'scars' of large ancient impacts that have been flatteded by glacier-like flows.

  1. Temperature dependence of magnetoelastic properties of Fe100−xSix (5 < x < 20)

    SciTech Connect

    Petculescu, G.; Lambert, P.K.; Clark, A.E.; Hathaway, K.B.; Xing, Qingfeng; Lograsso, Tom; Restorff, J.B.; Wun-Fogle, M.

    2012-02-29

    Tetragonal magnetostriction (λγ,2) and elastic constants (c′, c44, and c11) for Fe100−xSix were measured as a function of temperature (T). Compositions corresponding to the disordered A2 (x = 5), ordered D03 (x = 19.8), and mixed (x = 11.6) phases, were investigated. The magnetoelastic coupling (−b1) was determined for 77 < T < 300 K and compared with those of Fe-Ga, Fe-Ge, and Fe-Al. Both λγ,2(T) and −b1(T) of Fe-Si behave similarly to those of Fe-Ge, while other notable differences exist between the measured properties of Fe-Si and those of the other three alloys. Due to the early establishment of short range order, Fe-Si exhibits a positive, although small, slope in λγ,2(T) at 5 at. % Si, and a remarkable drop in −b1 before the solubility limit. The weaker softening of the tetragonal shear modulus with the addition of Si and the lack of strong anharmonic effects in the Fe-Si lattice inferred from the weak T-dependence of all the moduli suggest that Fe-Si exhibits more structural stability than the other three alloys. The distinctive behavior is likely due to the smaller size of Si compared to the sizes of Ga, Ge and Al, and therefore to the effect of the larger size difference between Fe and Si in the Fe-Si lattice.

  2. Optical properties of (Se80Te20)100-xAgx (0 ≤ x ≤ 4) thin films

    NASA Astrophysics Data System (ADS)

    Singh, D.; Kumar, S.; Sandhu, S.; Thangaraj, R.

    2014-04-01

    Thin films of (Se80Te20)100-xAgx (0 ≤ x ≤ 4) glasses were prepared by thermal evaporation of the bulk samples. The transmittance (T) and reflection (R) spectra of amorphous thin films were obtained in the spectral region in the range 400-2500 nm. The optical band gap (Eg) has been determined by Tauc's extrapolation method. The surface morphology has been determined by the Scanning Electron Microscopy (SEM).

  3. Optimization of un-tethered, low voltage, 20100 kHz flexural transducers for biomedical ultrasonics applications

    PubMed Central

    Sunny, Youhan; Bawiec, Christopher R.; Nguyen, An T.; Samuels, Joshua A.; Weingarten, Michael S.; Zubkov, Leonid A.; Lewin, Peter A.

    2012-01-01

    This paper describes optimization of un-tethered, low voltage, 20100 kHz flexural transducers for biomedical ultrasonics applications. The goal of this work was to design a fully wearable, low weight (<100 g), battery operated, piezoelectric ultrasound applicator providing maximum output pressure amplitude at the minimum excitation voltage. Such implementation of ultrasound applicators that can operate at the excitation voltages on the order of only 10–25 V is needed in view of the emerging evidence that spatial-peak temporal-peak ultrasound intensity (ISPTP) on the order of 100 mW/cm2 delivered at frequencies below 100 kHz can have beneficial therapeutic effects. The beneficial therapeutic applications include wound management of chronic ulcers and non-invasive transdermal delivery of insulin and liposome encapsulated drugs. The early prototypes of the 20 and 100 kHz applicators were optimized using the maximum electrical power transfer theorem, which required a punctilious analysis of the complex impedance of the piezoelectric disks mounted in appropriately shaped metal housings. In the implementation tested, the optimized ultrasound transducer applicators were driven by portable, customized electronics, which controlled the excitation voltage amplitude and facilitated operation in continuous wave (CW) or pulsed mode with adjustable (10–90%) duty cycle. The driver unit was powered by remotely located rechargeable lithium (Li) polymer batteries. This was done to further minimize the weight of the applicator unit making it wearable. With DC voltage of approximately 15 V the prototypes were capable of delivering pressure amplitudes of about 55 kPa or 100 mW/cm2 (ISPTP). This level of acoustic output was chosen as it is considered safe and side effects free, even at prolonged exposure. PMID:22513259

  4. Optimization of un-tethered, low voltage, 20-100kHz flexural transducers for biomedical ultrasonics applications.

    PubMed

    Sunny, Youhan; Bawiec, Christopher R; Nguyen, An T; Samuels, Joshua A; Weingarten, Michael S; Zubkov, Leonid A; Lewin, Peter A

    2012-09-01

    This paper describes optimization of un-tethered, low voltage, 20-100kHz flexural transducers for biomedical ultrasonics applications. The goal of this work was to design a fully wearable, low weight (<100g), battery operated, piezoelectric ultrasound applicator providing maximum output pressure amplitude at the minimum excitation voltage. Such implementation of ultrasound applicators that can operate at the excitation voltages on the order of only 10-25V is needed in view of the emerging evidence that spatial-peak temporal-peak ultrasound intensity (I(SPTP)) on the order of 100mW/cm(2) delivered at frequencies below 100kHz can have beneficial therapeutic effects. The beneficial therapeutic applications include wound management of chronic ulcers and non-invasive transdermal delivery of insulin and liposome encapsulated drugs. The early prototypes of the 20 and 100kHz applicators were optimized using the maximum electrical power transfer theorem, which required a punctilious analysis of the complex impedance of the piezoelectric disks mounted in appropriately shaped metal housings. In the implementation tested, the optimized ultrasound transducer applicators were driven by portable, customized electronics, which controlled the excitation voltage amplitude and facilitated operation in continuous wave (CW) or pulsed mode with adjustable (10-90%) duty cycle. The driver unit was powered by remotely located rechargeable lithium (Li) polymer batteries. This was done to further minimize the weight of the applicator unit making it wearable. With DC voltage of approximately 15V the prototypes were capable of delivering pressure amplitudes of about 55kPa or 100mW/cm(2) (I(SPTP)). This level of acoustic output was chosen as it is considered safe and side effects free, even at prolonged exposure.

  5. Origin Hypotheses for Kilometer-Scale Mounds on Dwarf Planet Ceres

    NASA Astrophysics Data System (ADS)

    Sizemore, Hanna G.; Platz, Thomas; Schmidt, Britney E.; Scully, Jennifer E. C.; Russell, Christopher T.; Mest, Scott C.; Crown, David A.; Sykes, Mark V.; Hughson, Kynan H. G.; Chilton, Heather T.; Williams, David A.; Pieters, Carle M.; Marchi, Simone; Travis, Bryan; Raymond, Carol A.

    2015-11-01

    The Dawn Framing Camera has revealed numerous domical to conical features on Ceres, which may have relevance to the presence and history of near-surface ice. These features fall into two broad classes, large domes 10s to >100 km in diameter exhibiting 1-5 km of positive relief, and small mounds <10 km in diameter exhibiting sub-kilometer relief. Here, we propose three hypotheses for the origin of the ~150 small mounds identified thus far, and discuss morphological observations that could support each hypothesis as higher resolution data becomes available.Hypothesis 1: Kilometer-scale mounds are produced by localized eruption of cryomagma or hydrothermal material. Observational tests: Kilometer and sub-kilometer scale albedo variations; sub-kilometer flow features on individual mounds; localized vents; conical or domical shape. Challenge: Features are smaller than convective plumes expected from thermal evolution modeling.Hypothesis 2: Kilometer-scale mounds are analogous to terrestrial and martian pingos, which grow by drawing liquid water through a silicate matrix as a freezing front propagates downward. Observational tests: Mounds occurring on smooth material that floods or embays large-scale features; little or no local albedo variation; no small flows associated with individual mounds; domical or ring-shape; concentric or radial fractures on dome, or central depression. Challenge: Small Cerean mounds observed thus far are an order of magnitude larger than terrestrial or martian pingos.Hypothesis 3: Kilometer-scale mounds are rootless cones analogous to features observed on the surface of volcanic flows in volatile-rich regions of Earth and Mars. Rootless cones are produced when layers of fluid material inundate a region; localized devolatilization of a layer mobilizes clasts to form cone-shaped deposits. Observational tests: Mounds on smooth material that floods or embays large-scale features; conical, not domical, profile; large central

  6. The Era of Kilometer-Scale Neutrino Detectors

    DOE PAGES

    Halzen, Francis; Katz, Uli

    2013-01-01

    Neutrino astronomy beyond the Sun was first imagined in the late 1950s; by the 1970s, it was realized that kilometer-scale neutrino detectors were required. The first such instrument, IceCube, transforms a cubic kilometer of deep and ultra-transparent Antarctic ice into a particle detector. KM3NeT, an instrument that aims to exploit several cubic kilometers of the deep Mediterranean sea as its detector medium, is in its final design stages. The scientific missions of these instruments include searching for sources of cosmic rays and for dark matter, observing Galactic supernova explosions, and studying the neutrinos themselves. Identifying the accelerators that produce Galacticmore » and extragalactic cosmic rays has been a priority mission of several generations of high-energy gamma-ray and neutrino telescopes; success has been elusive so far. Detecting the gamma-ray and neutrino fluxes associated with cosmic rays reaches a new watershed with the completion of IceCube, the first neutrino detector with sensitivity to the anticipated fluxes. In this paper, we will first revisit the rationale for constructing kilometer-scale neutrino detectors. We will subsequently recall the methods for determining the arrival direction, energy and flavor of neutrinos, and will subsequently describe the architecture of the IceCube and KM3NeT detectors.« less

  7. Neptune on Tiptoes: Dynamical Histories that Preserve the Cold Classical Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Wolff, Schuyler; Dawson, Rebekah I.; Murray-Clay, Ruth A.

    2012-02-01

    The current dynamical structure of the Kuiper Belt was shaped by the orbital evolution of the giant planets, especially Neptune, during the era following planet formation when the giant planets may have undergone planet-planet scattering and/or planetesimal-driven migration. Numerical simulations of this process, while reproducing many properties of the Belt, fail to generate the high inclinations and eccentricities observed for some objects while maintaining the observed dynamically "cold" population. We present the first of a three-part parameter study of how different dynamical histories of Neptune sculpt the planetesimal disk. Here we identify which dynamical histories allow an in situ planetesimal disk to remain dynamically cold, becoming today's cold Kuiper Belt population. We find that if Neptune undergoes a period of elevated eccentricity and/or inclination, it secularly excites the eccentricities and inclinations of the planetesimal disk. We demonstrate that there are several well-defined regimes for this secular excitation, depending on the relative timescales of Neptune's migration, the damping of Neptune's orbital inclination and/or eccentricity, and the secular evolution of the planetesimals. We model this secular excitation analytically in each regime, allowing for a thorough exploration of parameter space. Neptune's eccentricity and inclination can remain high for a limited amount of time without disrupting the cold classical belt. In the regime of slow damping and slow migration, if Neptune is located (for example) at 20 AU, then its eccentricity must stay below 0.18 and its inclination below 6°.

  8. NEPTUNE ON TIPTOES: DYNAMICAL HISTORIES THAT PRESERVE THE COLD CLASSICAL KUIPER BELT

    SciTech Connect

    Wolff, Schuyler; Dawson, Rebekah I.; Murray-Clay, Ruth A. E-mail: rdawson@cfa.harvard.edu

    2012-02-20

    The current dynamical structure of the Kuiper Belt was shaped by the orbital evolution of the giant planets, especially Neptune, during the era following planet formation when the giant planets may have undergone planet-planet scattering and/or planetesimal-driven migration. Numerical simulations of this process, while reproducing many properties of the Belt, fail to generate the high inclinations and eccentricities observed for some objects while maintaining the observed dynamically 'cold' population. We present the first of a three-part parameter study of how different dynamical histories of Neptune sculpt the planetesimal disk. Here we identify which dynamical histories allow an in situ planetesimal disk to remain dynamically cold, becoming today's cold Kuiper Belt population. We find that if Neptune undergoes a period of elevated eccentricity and/or inclination, it secularly excites the eccentricities and inclinations of the planetesimal disk. We demonstrate that there are several well-defined regimes for this secular excitation, depending on the relative timescales of Neptune's migration, the damping of Neptune's orbital inclination and/or eccentricity, and the secular evolution of the planetesimals. We model this secular excitation analytically in each regime, allowing for a thorough exploration of parameter space. Neptune's eccentricity and inclination can remain high for a limited amount of time without disrupting the cold classical belt. In the regime of slow damping and slow migration, if Neptune is located (for example) at 20 AU, then its eccentricity must stay below 0.18 and its inclination below 6 Degree-Sign .

  9. Precise Astrometry for Predicting Kuiper Belt Object Occultations

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott; Elliot, James; Kern, Susan; Zuluaga, Carlos; Gulbis, Amanda

    2008-08-01

    In order to observe an occultation of a bright star by a Kuiper Belt object the event must first be predicted as to where and when it will happen. These predictions require precise astrometry every few months of the largest Kuiper Belt objects. Through the occultation events the diameters, possible companions and possible tenuous atmospheres around these objects will be explored by examining how the light from the star varies as the KBO passes in front of it. This promises to be a completely new and powerful way of exploring the KBOs. We propose to continue to obtain very precise astrometry on the known brightest KBOs to determine more accurate orbits and thus reliable occultation predictions. In addition, we must also obtain accurate astrometry on faint field stars that the KBOs of interest may occult.

  10. Precise Astrometry for Predicting Kuiper Belt Object Occultations

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott; Elliot, James; Kern, Susan; Zuluaga, Carlos; Gulbis, Amanda

    2010-02-01

    In order to observe an occultation of a bright star by a Kuiper Belt object the event must first be predicted as to where and when it will happen. These predictions require precise astrometry every few months of the largest Kuiper Belt objects. Through the occultation events the diameters, possible companions and possible tenuous atmospheres around these objects will be explored by examining how the light from the star varies as the KBO passes in front of it. This promises to be a completely new and powerful way of exploring the KBOs. We propose to continue to obtain very precise astrometry on the known brightest KBOs to determine more accurate orbits and thus reliable occultation predictions. In addition, we must also obtain accurate astrometry on faint field stars that the KBOs of interest may occult. On October 9, 2009 we predict KBO 55636 will occult a 13th magnitude star and this will be our first attempt to observe such an event.

  11. The Kuiper belt and the solar system's comet disk.

    PubMed

    Gladman, Brett

    2005-01-07

    Our planetary system is embedded in a small-body disk of asteroids and comets, vestigial remnants of the original planetesimal population that formed the planets. Once formed, those planets dispersed most of the remaining small bodies. Outside of Neptune, this process has left our Kuiper belt and built the Oort cloud, as well as emplacing comets into several other identifiable structures. The orbits in these structures indicate that our outer solar system's comet disk was shaped by a variety of different physical processes, which teach us about how the giant planets formed. Recent work has shown that the scattered disk is the most likely source of short-period comets. Moreover, a growing body of evidence indicates that the sculpting of the Kuiper belt region may have involved large-scale planetary migration, the presence of other rogue planetary objects in the disk, and/or the close passage of other stars in the Sun's birth cluster.

  12. The Kuiper Belt and the Solar System's Comet Disk

    NASA Astrophysics Data System (ADS)

    Gladman, Brett

    2005-01-01

    Our planetary system is embedded in a small-body disk of asteroids and comets, vestigial remnants of the original planetesimal population that formed the planets. Once formed, those planets dispersed most of the remaining small bodies. Outside of Neptune, this process has left our Kuiper belt and built the Oort cloud, as well as emplacing comets into several other identifiable structures. The orbits in these structures indicate that our outer solar system's comet disk was shaped by a variety of different physical processes, which teach us about how the giant planets formed. Recent work has shown that the scattered disk is the most likely source of short-period comets. Moreover, a growing body of evidence indicates that the sculpting of the Kuiper belt region may have involved large-scale planetary migration, the presence of other rogue planetary objects in the disk, and/or the close passage of other stars in the Sun's birth cluster.

  13. THE DENSITY OF MID-SIZED KUIPER BELT OBJECT 2002 UX25 AND THE FORMATION OF THE DWARF PLANETS

    SciTech Connect

    Brown, M. E.

    2013-12-01

    The formation of the largest objects in the Kuiper belt, with measured densities of ∼1.5 g cm{sup –3} and higher, from the coagulation of small bodies, with measured densities below 1 g cm{sup –3}, is difficult to explain without invoking significant porosity in the smallest objects. If such porosity does occur, measured densities should begin to increase at the size at which significant porosity is no longer supported. Among the asteroids, this transition occurs for diameters larger than ∼350 km. In the Kuiper belt, no density measurements have been made between ∼350 km and ∼850 km, the diameter range where porosities might first begin to drop. Objects in this range could provide key tests of the rock fraction of small Kuiper belt objects (KBOs). Here we report the orbital characterization, mass, and density determination of the 2002 UX25 system in the Kuiper belt. For this object, with a diameter of ∼650 km, we find a density of 0.82 ± 0.11 g cm{sup –3}, making it the largest solid known object in the solar system with a measured density below that of pure water ice. We argue that the porosity of this object is unlikely to be above ∼20%, suggesting a low rock fraction. If the currently measured densities of KBOs are a fair representation of the sample as a whole, creating ∼1000 km and larger KBOs with rock mass fractions of 70% and higher from coagulation of small objects with rock fractions as low as those inferred from 2002 UX25 is difficult.

  14. Surface Color Frequencies and Ratios Within the Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Schwamb, Megan Elizabeth; Fraser, Wesley Cristopher; Bannister, Michele T.; Pike, Rosemary E.; Marsset, Michael; Kavelaars, J. J.; Benecchi, Susan D.; Delsanti, Audrey C.; Lehner, Matthew; Wang, Shiang-Yu; Thirouin, Audrey; Guilbert-Lepoutre, Aurelie; Peixinho, Nuno; Vernazza, Pierre; Nesvorny, David

    2016-10-01

    We have an understanding of the surface properties for the largest Kuiper belt objects (KBOs) which retain their primordial inventory of volatile ices. The vast majority of the known dwarf-planet sized bodies are bright enough to be studied through optical and infrared spectroscopy. For the typically smaller > 22 mag KBO, we must rely instead on what colors reveal by proxy; yet this picture remains incomplete. Most KBO physical property studies examine the hodgepodge set of objects discovered by various surveys with different and varying detection biases that make it difficult if not impossible to accurately estimate the sizes of the different surface color groups residing in the modern-day Kupier belt. The Colours of the Outer Solar System Origins Survey (Col-OSSOS) probes the surface properties within the Kuiper belt primarily through near simultaneous g,r and J colors with the Gemini North Telescope. The survey targets KBOs brighter than 23.6 r‧ mag found by the Outer Solar System Origins Survey (OSSOS). With Col-OSSOS, we have a sample of KBO colors measured for a set of objects detected in a brightness limited survey, with a well-measured detection efficiency. This affords the first opportunity to explore the true frequency of surface colors within the Kuiper belt, subdivided by dynamical classification.Using the ~30 KBOs studied from the first complete OSSOS block, we present the observed and debiased ratio of neutral to red KBOs. We also measure the populations of the three color KBO subgroups (the red and neutral dynamically excited population and the red cold classical belt). Additionally, Kuiper belt formation models predict that the dynamically excited KBOs (hot classical belt, resonant orbits, and scattered disk) were implanted during Neptune's migration. With the true frequency of neutral to red bodies from Col-OSSOS, we examine the implications for the radial color distribution in the primordial planetesimal disk from which the excited KBOs

  15. Corralling a Distant Planet with Extreme Resonant Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Malhotra, Renu; Volk, Kathryn; Wang, Xianyu

    2016-06-01

    The four longest period Kuiper Belt objects have orbital periods close to integer ratios with each other. A hypothetical planet with an orbital period of ∼17,117 years and a semimajor axis ∼665 au would have N/1 and N/2 period ratios with these four objects. The orbital geometries and dynamics of resonant orbits constrain the orbital plane, the orbital eccentricity, and the mass of such a planet as well as its current location in its orbital path.

  16. Cosmic Ray Mantle Visibility on Kuiper Belt Objects

    NASA Technical Reports Server (NTRS)

    Cooper, John F.; Hill, Matt E.; Richardson, J. D.; Sturner, S. J.

    2006-01-01

    Optically red objects constitute the dynamically cold, old component of the Classical Kuiper Belt (40 - 47 AU) with heliocentric orbits of low eccentricity and inclination. The red colors likely arise from primordial mixed ices processed by irradiation to meters in surface depth over the past four billion years, since the time of giant planet migration and Kuiper Belt stirring, at relatively moderate dosages of 60 gigarads provided by galactic cosmic ray protons and heavier ions. The red cosmic ray mantle is uniformly visible on the cold classical objects beneath a minimally thin eroded layer of more neutrally colored material arising from cumulative effects of heliospheric particle irradiation. The radiation fluxes are lowest in the middle heliospheric region containing the Classical Kuiper Belt and increase from there both towards and away from the Sun. Despite increasing irradiation at various times of solar system history from increases in solar and interstellar ion fluxes, the red object region has apparently never reached sufficiently high dosage levels to neutralize in color the red mantle material. Erosion processes, including plasma sputtering and micrometeroid impacts, act continuously to reduce thickness of the upper neutral crust and expose the cosmic ray mantle. A deeper layer at tens of meters and more may consist of relatively unprocessed ices that can erupt to the surface by larger impacts or cryovolcanism and account for brighter surfaces of larger objects such as 2003 UB313. Surface colors among the Kuiper Belt and other icy objects of the outer solar system are then a function, assuming uniform primordial composition, of relative thickness for the three layers and of the resurfacing age dependent on the orbital and impact history of each object.

  17. Cosmic Ray Mantle Visibility on Kuiper Belt Objects

    NASA Technical Reports Server (NTRS)

    Cooper, John F.; Hill, Matt E.; Richardson, J. D.; Sturner, S. J.

    2006-01-01

    Optically red objects constitute the dynamically cold, old component of the Classical Kuiper Belt (40 - 47 AU) with heliocentric orbits of low eccentricity and inclination. The red colors likely arise from primordial mixed ices processed by irradiation to meters in surface depth over the past four billion years, since the time of giant planet migration and Kuiper Belt stirring, at relatively moderate dosages of 60 gigarads provided by galactic cosmic ray protons and heavier ions. The red cosmic ray mantle is uniformly visible on the cold classical objects beneath a minimally thin eroded layer of more neutrally colored material arising from cumulative effects of heliospheric particle irradiation. The radiation fluxes are lowest in the middle heliospheric region containing the Classical Kuiper Belt and increase from there both towards and away from the Sun. Despite increasing irradiation at various times of solar system history from increases in solar and interstellar ion fluxes, the red object region has apparently never reached sufficiently high dosage levels to neutralize in color the red mantle material. Erosion processes, including plasma sputtering and micrometeroid impacts, act continuously to reduce thickness of the upper neutral crust and expose the cosmic ray mantle. A deeper layer at tens of meters and more may consist of relatively unprocessed ices that can erupt to the surface by larger impacts or cryovolcanism and account for brighter surfaces of larger objects such as 2003 UB313. Surface colors among the Kuiper Belt and other icy objects of the outer solar system are then a function, assuming uniform primordial composition, of relative thickness for the three layers and of the resurfacing age dependent on the orbital and impact history of each object.

  18. A HYPOTHESIS FOR THE COLOR DIVERSITY OF THE KUIPER BELT

    SciTech Connect

    Brown, M. E.; Fraser, W. C.; Schaller, E. L.

    2011-10-01

    We propose a chemical and dynamical process to explain the surface colors of the Kuiper belt. In our hypothesis, the initial bulk compositions of the bodies themselves can be quite diverse-as is seen in comets-but the early surface compositions are set by volatile evaporation after the objects are formed. Strong gradients in surface composition, coupled with UV and particle irradiation, lead to the surface colors that are seen today. The objects formed in the inner part of the primordial belt retain only H{sub 2}O and CO{sub 2} as the major ice species on their surfaces. Irradiation of these species plausibly results in the dark neutrally colored centaurs and Kuiper belt objects (KBOs). Object formed further in the disk retain CH{sub 3}OH, which has been shown to lead to brighter redder surfaces after irradiation, as seen in the brighter redder centaurs and KBOs. Objects formed at the current location of the cold classical Kuiper belt uniquely retain NH{sub 3}, which has been shown to affect irradiation chemistry and could plausibly lead to the unique colors of these objects. We propose observational and experimental tests of this hypothesis.

  19. Crystalline water ice on the Kuiper belt object (50000) Quaoar.

    PubMed

    Jewitt, David C; Luu, Jane

    2004-12-09

    The Kuiper belt is a disk-like structure consisting of solid bodies orbiting the Sun beyond Neptune. It is the source of the short-period comets and the likely repository of the Solar System's most primitive materials. Surface temperatures in the belt are low ( approximately 50 K), suggesting that ices trapped at formation should have been preserved over the age of the Solar System. Unfortunately, most Kuiper belt objects are too faint for meaningful compositional study, even with the largest available telescopes. Water ice has been reported in a handful of objects, but most appear spectrally featureless. Here we report near-infrared observations of the large Kuiper belt object (50000) Quaoar, which reveal the presence of crystalline water ice and ammonia hydrate. Crystallinity indicates that the ice has been heated to at least 110 K. Both ammonia hydrate and crystalline water ice should be destroyed by energetic particle irradiation on a timescale of about 10(7) yr. We conclude that Quaoar has been recently resurfaced, either by impact exposure of previously buried (shielded) ices or by cryovolcanic outgassing, or by a combination of these processes.

  20. Ramifications of a Divot in the Kuiper Belt's Size Distribution

    NASA Astrophysics Data System (ADS)

    Gladman, Brett; Shankman, C.; Kaib, N.; Kavelaars, J.; Petit, J.

    2012-10-01

    Our recent detection (see Shankman et al., this meeting) of a divot in the distribution of numbers of Scattering TNOs as a function of absolute magnitude would, if extended to all Kuiper Belt sub-populations, simultaneously explain several outstanding curiosities in the literature. We examine these puzzles in the context of our proposed divot scenario and provide a cohesive picture of the "hot" Trans-Neptunian populations (the scattering, inner belt, hot main belt, outer/detached, and resonant populations). We explore the observed rollover in the Kuiper Belt's luminosity function, the "missing" Neptune Trojans, the source of the Jupiter Family Comets, and patterns seen in the hot/cold ratio as a function of magnitude. Our interpretation is that a detected divot is a preserved relic of the size distribution made by planetesimal formation, now "frozen in" to portions of the Kuiper Belt which share a "hot" orbital inclination distribution. This research was supported by the Canadian National Sciences and Engineering Research Council.

  1. 20-100 keV K(alpha) X-Ray Source Generation by Short Pulse High Intensity Lasers

    SciTech Connect

    Park, H-S; Koch, J A; Landen, O L; Phillips, T W; Goldsack, T

    2003-08-22

    We are studying the feasibility of utilizing K{alpha} x-ray sources in the range of 20 to 100 keV as a backlighters for imaging various stages of implosions and high areal density planar samples driven by the NIF laser facility. The hard x-ray K{alpha} sources are created by relativistic electron plasma interactions in the target material after a radiation by short pulse high intensity lasers. In order to understand K{alpha} source characteristics such as production efficiency and brightness as a function of laser parameters, we have performed experiments using the 10 J, 100 fs JanUSP laser. We utilized single-photon counting spectroscopy and x-ray imaging diagnostics to characterize the K{alpha} source. We find that the K{alpha} conversion efficiency from the laser energy is {approx} 3 x 10{sup -4}.

  2. Design and operational experience of a microwave cavity axion detector for the 20100μeV range

    DOE PAGES

    Al Kenany, S.; Anil, M. A.; Backes, K. M.; ...

    2017-02-09

    We describe a dark matter axion detector designed, constructed, and operated both as an innovation platform for new cavity and amplifier technologies and as a data pathfinder in the 5-25 GHz range (~20-100 eV). The platform is small but flexible to facilitate the development of new microwave cavity and amplifier concepts in an operational environment. The experiment has recently completed its first data production; it is the first microwave cavity axion search to deploy a Josephson parametric amplifier and a dilution refrigerator to achieve near-quantum limited performance.

  3. Design and operational experience of a microwave cavity axion detector for the 20 - 100 μeV range

    NASA Astrophysics Data System (ADS)

    Al Kenany, S.; Anil, M. A.; Backes, K. M.; Brubaker, B. M.; Cahn, S. B.; Carosi, G.; Gurevich, Y. V.; Kindel, W. F.; Lamoreaux, S. K.; Lehnert, K. W.; Lewis, S. M.; Malnou, M.; Palken, D. A.; Rapidis, N. M.; Root, J. R.; Simanovskaia, M.; Shokair, T. M.; Urdinaran, I.; van Bibber, K. A.; Zhong, L.

    2017-05-01

    We describe a dark matter axion detector designed, constructed, and operated both as an innovation platform for new cavity and amplifier technologies and as a data pathfinder in the 5-25 GHz range (∼ 20 - 100 μeV) . The platform is small but flexible to facilitate the development of new microwave cavity and amplifier concepts in an operational environment. The experiment has recently completed its first data production; it is the first microwave cavity axion search to deploy a Josephson parametric amplifier and a dilution refrigerator to achieve near-quantum limited performance.

  4. Experimental demonstration of kilometer-range quantum digital signatures

    NASA Astrophysics Data System (ADS)

    Donaldson, Ross J.; Collins, Robert J.; Kleczkowska, Klaudia; Amiri, Ryan; Wallden, Petros; Dunjko, Vedran; Jeffers, John; Andersson, Erika; Buller, Gerald S.

    2016-01-01

    We present an experimental realization of a quantum digital signature protocol which, together with a standard quantum key distribution link, increases transmission distance to kilometer ranges, three orders of magnitude larger than in previous realizations. The bit rate is also significantly increased compared with previous quantum signature demonstrations. This work illustrates that quantum digital signatures can be realized with optical components similar to those used for quantum key distribution and could be implemented in existing quantum optical fiber networks.

  5. Neptune's Migration into a Stirred-Up Kuiper Belt: A Detailed Comparison of Simulations to Observations

    NASA Astrophysics Data System (ADS)

    Hahn, Joseph M.; Malhotra, Renu

    2005-11-01

    We use N-body simulations to examine the consequences of Neptune's outward migration into the Kuiper Belt, with the simulated end states being compared rigorously and quantitatively to the observations. These simulations confirm the 2003 findings of Chiang and coworkers, who showed that Neptune's migration into a previously stirred-up Kuiper Belt can account for the Kuiper Belt objects (KBOs) known to librate at Neptune's 5:2 resonance. We also find that capture is possible at many other weak, high-order mean-motion resonances, such as 11:6, 13:7, 13:6, 9:4, 7:3, 12:5, 8:3, 3:1, 7:2, and 4:1. The more distant of these resonances, such as the 9:4, 7:3, 5:2, and 3:1, can also capture particles in stable, eccentric orbits beyond 50 AU, in the region of phase space conventionally known as the ``Scattered Disk.'' Indeed, 90% of the simulated particles that persist over the age of the solar system in the Scattered-Disk zone never had a close encounter with Neptune but instead were promoted into these eccentric orbits by Neptune's resonances during the migration epoch. This indicates that the observed Scattered Disk might not be so scattered. This model also produced only a handful of Centaurs, all of which originated at Neptune's mean-motion resonances in the Kuiper Belt. However, a noteworthy deficiency of the migration model considered here is that it does not account for the observed abundance of Main Belt KBOs having inclinations higher than 15°. In order to rigorously compare the model end state with the observed Kuiper Belt in a manner that accounts for telescopic selection effects, Monte Carlo methods are used to assign sizes and magnitudes to the simulated particles that survive over the age of the solar system. If the model considered here is indeed representative of the outer solar system's early history, then the following conclusions are obtained: (1) The observed 3:2 and 2:1 resonant populations are both depleted by a factor of ~20 relative to model

  6. High Resolution, 20-100 keV X-ray Backlighters for ICF and HEDS Experiments

    NASA Astrophysics Data System (ADS)

    Park, Hye-Sook; Koch, J. A.; Landen, O. L.; Phillips, T. W.; Schmid, G. J.

    2002-11-01

    We are studying the feasibility of high resolution radiography using short pulse high intensity lasers. Specifically we wish to better characterize and optimize the Kalpha X-ray production and brightness created by relativistic electron plasma interactions in the target material. We plan to utilize this Kalpha source as a backlighter to image various stages of implosions and planar driven high Z materials. Particularly interesting are the production of Kalpha's in the range 20 100 keV. In order to assess in detail the characteristics of such high energy X-ray backlighters, we are performing experiments using the 10 J, 100 fs JanUSP laser at LLNL. We will measure Kalpha source generation efficiency as function of laser beam parameters such as pulse duration, spot size and laser beam energy. We are also developing a high resolution hard X-ray imaging detector system. This paper will present initial results from the JanUSP experiments. Reference:D.K. Bradley, O.L. Landen, A.B. Bullock, S.G. Glendinning, and R.E. Turner, "Efficient, High Spatial-Temporal Resolution, 1-100 keV X-ray Radiography," Opt. Lett. 27(2002) 134.

  7. Finite Element Static Displacement Optimization of 20100 kHz flexural transducers for fully portable ultrasound applicator

    PubMed Central

    Bawiec, Christopher R.; Sunny, Youhan; Nguyen, An T.; Samuels, Joshua A.; Weingarten, Michael S.; Zubkov, Leonid A.; Lewin, Peter A.

    2012-01-01

    This paper focuses on the development of a finite-element model and subsequent stationary analysis performed to optimize individual flexural piezoelectric elements for operation in the frequency range of 20100 kHz. These elements form the basic building blocks of a viable, un-tethered, and portable ultrasound applicator that can produce intensities on the order of 100 mW/cm2 spatial-peak temporal-peak (ISPTP) with minimum (on the order of 15 V) excitation voltage. The ultrasound applicator can be constructed with different numbers of individual transducer elements and different geometries such that its footprint or active area is adjustable. The primary motivation behind this research was to develop a tether-free, battery operated, fully portable ultrasound applicator for therapeutic applications such as wound healing and non-invasive transdermal delivery of both naked and encapsulated drugs. It is shown that careful selection of the components determining applicator architecture allows the displacement amplitude to be maximized for a specific frequency of operation. The work described here used the finite-element analysis software COMSOL to identify the geometry and material properties that permit the applicator’s design to be optimized. By minimizing the excitation voltage required to achieve the desired output (100 mW/cm2 ISPTP) the power source (rechargeable Li-Polymer batteries) size may be reduced permitting both the electronics and ultrasound applicator to fit in a wearable housing [1]. PMID:23040829

  8. DUst around NEarby Stars (DUNES): searching for Kuiper-belt analogues around solar-type stars

    NASA Astrophysics Data System (ADS)

    Montesinos, B.; Dunes Consortium

    2011-11-01

    In this paper we summarize some of the results of the Herschel Open Time Key Programme DUNES (DUst around NEarby Stars). This project aims at detecting and studying cold dust discs, i.e. Edgeworth-Kuiper-belt analogues, around FGK stars of the solar neighbourhood, in a volume-limited sample. The sensitivity and wavelengths of the two instruments used, namely PACS (70, 100 and 160 micron) and SPIRE (250, 350 and 500 micron) are the appropriate ones for these tasks. Despite of the fact that, at the time of writing these proceedings, only about half of the sample has been observed, new results and increased statistics with respect to previous surveys and observations have emerged. Some new, unexpected results, in the form of very cold discs, pose some challenges to the current modelling paradigms. Note that at the time this paper is published, the results given and some of the conclusions will be obviously out of date.

  9. Observations of Mutual Eclipses by the Binary Kuiper Belt Object Manwe-Thorondor

    NASA Astrophysics Data System (ADS)

    Rabinowitz, David L.; Benecchi, Susan D.; Grundy, William M.; Thirouin, Audrey; Verbiscer, Anne J.

    2016-10-01

    The binary Kuiper Belt Object (385446) Manwe-Thorondor (aka 2003 QW111) is currently undergoing mutual events whereby the two ~100-km bodies alternately eclipse and occult each other as seen from Earth [1]. Such events are extremely rare among KBOs (Pluto-Charon and Sila-Nunam being notable exceptions). For Manwe-Thorondor, the events occur over ~0.5-d periods 4 to 5 times per year until the end of 2019. Here we report the results of observations to be made with the Soar 4m telescope at Cerro Pachon, Chile on 2016 Aug 25 and 26 UT, covering one of the deepest predicted eclipses. We use these observations to constrain the rotational variability of the two bodies, determine their physical properties (size, shape, albedo, density), and set limits on the presence of any prominent surface features.[1] Grundy, W. et al. 2012, Icarus, 220, 74

  10. SKARPS: The Search for Kuiper Belts around Radial-Velocity Planet Stars

    NASA Technical Reports Server (NTRS)

    Bryden, Geoffrey; Marshall, Jonathan; Stapelfeldt, Karl; Su, Kate; Wyatt, Mark

    2011-01-01

    The Search for Kuiper belts Around Radial-velocity Planet Stars - SKARPS -is a Herschel survey of solar-type stars known to have orbiting planets. When complete, the 100-star SKARPS sample will be large enough for a meaningful statistical comparison against stars not known to have planets. (This control sample has already been observed by Herschel's DUst around NEarby Stars - DUNES - key program). Initial results include previously known disks that are resolved for the first time and newly discovered disks that are fainter and colder than those typically detected by Spitzer. So far, with only half of the sample in hand, there is no measured correlation between inner RV planets and cold outer debris. While this is consistent with the results from Spitzer, it is in contrast with the relationship suggested by the prominent debris disks in imaged-planet systems.

  11. Herschel's DEBRIS - An Update on the Search for Kuiper Belts Around the Nearest Stars

    NASA Astrophysics Data System (ADS)

    Butner, Harold M.; Matthews, B.; DEBRIS Survey Team

    2011-01-01

    DEBRIS (Disk Emission via a Bias-free Reconnaissance in the Infrared/Submillimetre) is an open time key project on Herschel that aims to conduct an unbiased statistical survey for debris disks around the nearest stars. The goal is to achieve flux-limited observations at 100 and 160 microns - and thereby reach unprecedented debris disk mass limits. The sample includes 446 primaries, 348 of which are observed by the DEBRIS team and 98 which are covered by another project (DUNES - DUst disks around NEarby Stars). The sample covers spectral types from A0 through M7, and is designed to allow the detection of dust masses similar to those of our own Kuiper belt. The superior resolution of Herschel combined with the fact that our sample are all nearby stars will provide resolved disks for many of the detected disks. We will discuss the status of ongoing Herschel observations for this unique unbiased survey of debris disk candidates.

  12. Kilometer-Spaced GNSS Array for Ionospheric Irregularity Monitoring

    NASA Astrophysics Data System (ADS)

    Su, Yang

    This dissertation presents automated, systematic data collection, processing, and analysis methods for studying the spatial-temporal properties of Global Navigation Satellite Systems (GNSS) scintillations produced by ionospheric irregularities at high latitudes using a closely spaced multi-receiver array deployed in the northern auroral zone. The main contributions include 1) automated scintillation monitoring, 2) estimation of drift and anisotropy of the irregularities, 3) error analysis of the drift estimates, and 4) multi-instrument study of the ionosphere. A radio wave propagating through the ionosphere, consisting of ionized plasma, may suffer from rapid signal amplitude and/or phase fluctuations known as scintillation. Caused by non-uniform structures in the ionosphere, intense scintillation can lead to GNSS navigation and high-frequency (HF) communication failures. With specialized GNSS receivers, scintillation can be studied to better understand the structure and dynamics of the ionospheric irregularities, which can be parameterized by altitude, drift motion, anisotropy of the shape, horizontal spatial extent and their time evolution. To study the structuring and motion of ionospheric irregularities at the sub-kilometer scale sizes that produce L-band scintillations, a closely-spaced GNSS array has been established in the auroral zone at Poker Flat Research Range, Alaska to investigate high latitude scintillation and irregularities. Routinely collecting low-rate scintillation statistics, the array database also provides 100 Hz power and phase data for each channel at L1/L2C frequency. In this work, a survey of seasonal and hourly dependence of L1 scintillation events over the course of a year is discussed. To efficiently and systematically study scintillation events, an automated low-rate scintillation detection routine is established and performed for each day by screening the phase scintillation index. The spaced-receiver technique is applied to cross

  13. THE SIZE, DENSITY, AND FORMATION OF THE ORCUS-VANTH SYSTEM IN THE KUIPER BELT

    SciTech Connect

    Brown, M. E.; Ragozzine, D.; Fraser, W. C.; Stansberry, J.

    2010-06-15

    The Kuiper Belt object (KBO) Orcus and its satellite Vanth form an unusual system in the Kuiper Belt. While most large KBOs have small satellites in circular orbits and smaller KBOs and their satellites tend to be much closer in size, Orcus sits in between these two regimes. Orcus is among the largest objects known in the Kuiper Belt, but the relative size of Vanth is much larger than that of the tiny satellites of the other large objects. Here, we characterize the physical and orbital characteristics of the Orcus-Vanth system in an attempt to distinguish discuss possible formation scenarios. From Hubble Space Telescope observations, we find that Orcus and Vanth have different visible colors and that Vanth does not share the water ice absorption feature seen in the infrared spectrum of Orcus. We also find that Vanth has a nearly face-on circular orbit with a period of 9.5393 {+-} 0.0001 days and semimajor axis of 8980 {+-} 20 km, implying a system mass of (6.32 {+-} 0.01) x 10{sup 20} kg or 3.8% the mass of dwarf planet Eris. From Spitzer Space Telescope observations, we find that the thermal emission is consistent with a single body with diameter 940 {+-} 70 km and a geometric albedo of 0.28 {+-} 0.04. Assuming equal densities and albedos, this measurement implies sizes of Orcus and Vanth of 900 and 280 km, respectively, and a mass ratio of 33. Assuming a factor of 2 lower albedo for the non-icy Vanth, however, implies sizes of 860 km and 380 km and a mass ratio of 12. The measured density depends on the assumed albedo ratio of the two objects but is approximately 1.5 {+-} 0.3 g cm{sup -3}, midway between typical densities measured for larger and smaller objects. The orbit and mass ratio is consistent with formation from a giant impact and subsequent outward tidal evolution, and even consistent with the system having now achieved a double synchronous state. Because of the large angle between the plane of the heliocentric orbit of Orcus and the plane of the orbit

  14. Fission time scales from anisotropic in-plane distributions in 100Mo+100Mo and 120Sn+120Sn collisions around 20A MeV

    NASA Astrophysics Data System (ADS)

    Casini, G.; Bizzeti, P. G.; Maurenzig, P. R.; Olmi, A.; Stefanini, A. A.; Wessels, J. P.; Charity, R. J.; Freifelder, R.; Gobbi, A.; Herrmann, N.; Hildenbrand, K. D.; Stelzer, H.

    1993-10-01

    The characteristics of the fission step following a binary deep-inelastic interaction have been reconstructed for three-body events detected in the reaction 100Mo+100Mo at 18.7A MeV and 12-Sn+120Sn at 18.4A MeV. The observed anisotropy of the in-plane angular distributions points to the fast decay of a rotating (and strongly deformed) nuclear object formed at the end of the deep-inelastic interaction. The derived time scale of the process indicates that asymmetric divisions are faster than symmetric ones.

  15. 25-Hydroxyvitamin D in the Range of 20 to 100 ng/mL and Incidence of Kidney Stones

    PubMed Central

    Nguyen, Stacie; Baggerly, Leo; French, Christine; Heaney, Robert P.; Gorham, Edward D.

    2014-01-01

    Objectives. Increasing 25-hydroxyvitamin D serum levels can prevent a wide range of diseases. There is a concern about increasing kidney stone risk with vitamin D supplementation. We used GrassrootsHealth data to examine the relationship between vitamin D status and kidney stone incidence. Methods. The study included 2012 participants followed prospectively for a median of 19 months. Thirteen individuals self-reported kidney stones during the study period. Multivariate logistic regression was applied to assess the association between vitamin D status and kidney stones. Results. We found no statistically significant association between serum 25-hydroxyvitamin D and kidney stones (P = .42). Body mass index was significantly associated with kidney stone risk (odds ratio = 3.5; 95% confidence interval = 1.1, 11.3). Conclusions. We concluded that a serum 25-hydroxyvitamin D level of 20 to 100 nanograms per milliliter has no significant association with kidney stone incidence. PMID:24134366

  16. An optical study of amorphous (Se80Te20)100-xGex thin films using their transmission spectra

    NASA Astrophysics Data System (ADS)

    Mainika; Sharma, Pankaj; Katyal, S. C.; Thakur, Nagesh

    2008-12-01

    Optical constants (refractive index and extinction coefficient) have been studied for a-(Se80Te20)100-xGex (x = 0, 2, 4, 6) thin films using transmission spectra in the wavelength range 500 2500 nm. It is observed from optical transmission measurements that the optical energy gap (Eg) increases while the refractive index (n) and the extinction coefficient (k) decrease with the incorporation of Ge in the Se Te system. The increase in the optical energy gap is interpreted by correlating the optical energy gap with the decrease in electronegativity and increase in the heat of atomization (Hs). The dispersion of the refractive index is discussed in terms of the single-oscillator Wemple DiDomenico model.

  17. First principles determination of the rhombohedral magnetostriction of Fe100-xGax and Fe100-xAlx (x<20) alloys

    NASA Astrophysics Data System (ADS)

    Wu, Ruqian; Zhang, Yanning

    2012-02-01

    Extensive efforts have been dedicated to investigate the extraordinary magnetostriction of Galfenol (Fe100-xGax) and Alfenal (Fe100-xAlx) alloys, which are very promising magnetostrictive materials for various applications such as sensors, transducers and spintronic devices. In contrast to the strong response of the tetragonal magnetostriction (λ100) to the Ga/Al concentration (x), the rhombohedral magnetostriction,λ111, vs. x curves for both FeGa and FeAl alloys show negative and steady values for 0100-x curves. Through highly-accurate full potential linearized augmented plane-wave method (FLAPW), our theoretical results nicely reproduce the main features of experimental λ111-x curves, except the opposite sign of λ111 of pure Fe. Detailed analyses on the structural and electronic properties of Galfenol provide deeper understandings of the origins of the sign change, as well as the large magnetostriction anisotropy in these alloys. Possible reasons on the disagreement between the calculated and observed rhombohedral magnetostriction of bcc Fe will also be given.

  18. Searching for Chips of Kuiper Belt Objects in Meteorites

    NASA Technical Reports Server (NTRS)

    Zolensky, M. E.; Ohsumi, K.; Briani, G.; Gounelle, M.; Mikouchi, T.; Satake, W.; Kurihara, T.; Weisberg, M. K.; Le, L.

    2009-01-01

    The Nice model [1&2] describes a scenario whereby the Jovian planets experienced a violent reshuffling event approx.3:9 Ga the giant planets moved, existing small body reservoirs were depleted or eliminated, and new reservoirs were created in particular locations. The Nice model quantitatively explains the orbits of the Jovian planets and Neptune [1], the orbits of bodies in several different small body reservoirs in the outer solar system (e.g., Trojans of Jupiter [2], the Kuiper belt and scattered disk [3], the irregular satellites of the giant planets [4], and the late heavy bombardment on the terrestrial planets approx.3:9 Ga [5]. This model is unique in plausibly explaining all of these phenomena. One issue with the Nice model is that it predicts that transported Kuiper Belt Objects (KBOs) (things looking like D class asteroids) should predominate in the outer asteroid belt, but we know only about 10% of the objects in the outer main asteroid belt appear to be D-class objects [6]. However based upon collisional modeling, Bottke et al. [6] argue that more than 90% of the objects captured in the outer main belt could have been eliminated by impacts if they had been weakly-indurated objects. These disrupted objects should have left behind pieces in the ancient regoliths of other, presumably stronger asteroids. Thus, a derived prediction of the Nice model is that ancient regolith samples (regolith-bearing meteorites) should contain fragments of collisionally-destroyed Kuiper belt objects. In fact KBO pieces might be expected to be present in most ancient regolith- bearing meteorites [7&8].

  19. Ultradeep (greater than 300 kilometers), ultramafic upper mantle xenoliths.

    PubMed

    Haggerty, S E; Sautter, V

    1990-05-25

    Geophysical discontinuities in Earth's upper mantle and experimental data predict the structural transformation of pyroxene to garnet and the solid-state dissolution of pyroxene into garnet with increasing depth. These predictions are indirectly verified by omphacitic pyroxene exsolution in pyropic garnet-bearing xenoliths from a diamondiferous kimberlite. Conditions for silicon in octahedral sites in the original garnets are met at pressures greater than 130 kilobars, placing the origin of these xenoliths at depths of 300 to 400 kilometers. These ultradeep xenoliths support the theory that the 400-km seismic discontinuity is marked by a transition from peridotite to eclogite.

  20. Analysis of Polarization Data from the Kuiper Airborne Observatory

    NASA Technical Reports Server (NTRS)

    Hildebrand, Roger H.

    1999-01-01

    The purpose of this grant was to complete the analysis of data obtained with the polarimeter, Hertz, on the Kuiper Airborne Observatory. This has enabled us to complete and publish two student theses (one on Sgr B2 and one on Orion) and a paper on the first results on the far-infrared polarization-spectrum. In addition it has enabled us to analyze data for two additional papers (one on W3 and the other a complete archive of KAO polarization data) which have reached the stage of complete drafts but still need checking and editing before final submission.

  1. Geological mapping of the Kuiper quadrangle (H06) of Mercury

    NASA Astrophysics Data System (ADS)

    Giacomini, Lorenza; Massironi, Matteo; Galluzzi, Valentina

    2017-04-01

    Kuiper quadrangle (H06) is located at the equatorial zone of Mercury and encompasses the area between longitudes 288°E - 360°E and latitudes 22.5°N - 22.5°S. The quadrangle was previously mapped for its most part by De Hon et al. (1981) that, using Mariner10 data, produced a final 1:5M scale map of the area. In this work we present the preliminary results of a more detailed geological map (1:3M scale) of the Kuiper quadrangle that we compiled using the higher resolution of MESSENGER data. The main basemap used for the mapping is the MDIS (Mercury Dual Imaging System) 166 m/pixel BDR (map-projected Basemap reduced Data Record) mosaic. Additional datasets were also taken into account, such as DLR stereo-DEM of the region (Preusker et al., 2016), global mosaics with high-incidence illumination from the east and west (Chabot et al., 2016) and MDIS global color mosaic (Denevi et al., 2016). The preliminary geological map shows that the western part of the quadrangle is characterized by a prevalence of crater materials (i.e. crater floor, crater ejecta) which were distinguished into three classes on the basis of their degradation degree (Galluzzi et al., 2016). Different plain units were also identified and classified as: (i) intercrater plains, represented by densely cratered terrains, (ii) intermediate plains, which are terrains with a moderate density of superposed craters, and (iii) smooth plains, which are poorly cratered volcanic deposits emplaced mainly on the larger crater floors. Finally, several structures were mapped all over the quadrangle. Most of these features are represented by thrusts, some of which appear to form systematic alignments. In particular, two main thrust systems have been identified: i) the "Thakur" system, a 1500 km-long system including several scarps with a NNE-SSW orientation, located at the edge between the Kuiper and Beethoven (H07) quadrangles; ii) the "Santa Maria" system, located at the centre of the quadrangle. It is a 1700 km

  2. Pettit and Kuipers conducting RoBoT Simulator Session

    NASA Image and Video Library

    2012-04-11

    ISS030-E-235593 (11 April 2012) --- In the International Space Station’s Destiny laboratory, NASA astronaut Don Pettit (foreground) and European Space Agency astronaut Andre Kuipers, both Expedition 30 flight engineers, conduct the first of three sessions on the ROBoT simulator in preparation for the arrival of the SpaceX Dragon. Slated for liftoff on April 30, 2012, at 12:22 (EDT) from the Kennedy Space Center, the goal of Dragon’s planned 21-day mission will be to test the unpiloted capsule’s ability to rendezvous with the space station.

  3. Pettit and Kuipers conducting RoBoT Simulator Session

    NASA Image and Video Library

    2012-04-11

    ISS030-E-235592 (11 April 2012) --- In the International Space Station’s Destiny laboratory, NASA astronaut Don Pettit (right) and European Space Agency astronaut Andre Kuipers, both Expedition 30 flight engineers, conduct the first of three sessions on the ROBoT simulator in preparation for the arrival of the SpaceX Dragon. Slated for liftoff on April 30, 2012, at 12:22 (EDT) from the Kennedy Space Center, the goal of Dragon’s planned 21-day mission will be to test the unpiloted capsule’s ability to rendezvous with the space station.

  4. Beyond the Kuiper Belt Edge: New High Perihelion Trans-Neptunian Objects with Moderate Semimajor Axes and Eccentricities

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott S.; Trujillo, Chadwick; Tholen, David J.

    2016-07-01

    We are conducting a survey for distant solar system objects beyond the Kuiper Belt edge (˜50 au) with new wide-field cameras on the Subaru and CTIO telescopes. We are interested in the orbits of objects that are decoupled from the giant planet region to understand the structure of the outer solar system, including whether a massive planet exists beyond a few hundred astronomical units as first reported in 2014 by Trujillo & Sheppard. In addition to discovering extreme trans-Neptunian objects detailed elsewhere, we found several objects with high perihelia (q > 40 au) that differ from the extreme and inner Oort cloud objects due to their moderate semimajor axes (50 < a < 100 au) and eccentricities (e ≲ 0.3). Newly discovered objects 2014 FZ71 and 2015 FJ345 have the third and fourth highest perihelia known after Sedna and 2012 VP113, yet their orbits are not nearly as eccentric or distant. We found several of these high-perihelion but moderate orbit objects and observe that they are mostly near Neptune mean motion resonances (MMRs) and have significant inclinations (i > 20°). These moderate objects likely obtained their unusual orbits through combined interactions with Neptune’s MMRs and the Kozai resonance, similar to the origin scenarios for 2004 XR190. We also find the distant 2008 ST291 has likely been modified by the MMR+KR mechanism through the 6:1 Neptune resonance. We discuss these moderately eccentric distant objects along with some other interesting low inclination outer classical belt objects like 2012 FH84 discovered in our ongoing survey.

  5. A Detailed Comparison of Simulations of Neptune's Migration to Observations of the Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Hahn, J. M.; Malhotra, R.

    2004-11-01

    Nbody simulations are used to examine Neptune's outwards migration and its subsequent dynamical erosion of the Kuiper Belt. Monte Carlo methods are then used to assign sizes and magnitudes so that the simulated and observed Kuiper Belts can be compared in a manner that accounts for telescopic biases. From this comparison we infer that the Belt is inhabited by N ˜ 2 x 105 KBOs orbiting interior to 50 AU with radii > 50 km having a total mass of M ˜ 0.08d(p/0.04)-1.5 earth masses, assuming these bodies have a density d in cgs units and an albedo p. Another interesting result is that the observed KBO populations at the 2:1 and the 3:2 resonances are both underabundant by a factor of ˜ 20 relative to model predictions; this depletion of the resonances is possibly due to unmodeled effects, such as perturbations by large planetesimals. Estimates of the abundances of the Belt's various subpopulations (Main Belt, resonant KBOs, Trojans, Centaurs, etc.) will be reported, as well as upper limits on distant KBOs orbiting beyond 50 AU with e ˜ 0.1. We also confirm the findings of Chiang et. al. (2003), who showed that Neptune's migration into a stirred-up Kuiper Belt having eccentricities of e 0.1 facilitates particle trapping at Neptune's 5:2. In addition, we find that trapping is possible at many other weak resonances, like the 11:6, 13:7, 13:6, 9:4, 7:3, 12:5, 8:3, 3:1, 7:2, and 4:1. The more distant of these resonances, the 9:4, 7:3, 5:2, and 3:1, can also promote KBOs beyond 50 AU into eccentric orbits that reside in the zone known as the Scattered Disk. However 90% of such particles in our simulation never had a close encounter with Neptune; rather they were placed there by Neptune's migrating resonances. This suggests that the so--called Scattered Disk might not be so scattered.

  6. Primary Accretion of Asteroids and Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Cuzzi, Jeff

    Primary accretion is the process by which the first large objects formed from freely- floating nebula particles. Several clues as to the nature of this process are to be found in primitive meteorites and asteroids. The most primitive chondritic meteorites display a characteristic texture: predominance of mm-sized, once-molten chondrules, metal grains, and refractory oxide particles, each surrounded by fine-grained dust rims and all embedded in a granular matrix. The size distribution of the chondrules in all classes of chondrite is quite narrow and nearly universal in shape, but with a mean size distinctive of each class. At least two entire chondrite classes are each thought to derive from only one or two planetesimals, roughly 100 km in radius and originally composed largely of chondrules with very similar properties. This ubiquitous and unusual texture is surely telling us something important about primary accretion, but there is no generally accepted explanation for it at present. Moreover, the extended duration of meteorite parent body formation as revealed in isotopic age-dating, and the scarcity of melted asteroids, suggest that primary accretion went on for a long time. In prior research we have shown how well-sorted, chondrule-sized mineral particles are concentrated, by orders of magnitude, into dense zones in weak nebula turbulence. This "turbulent concentration" explains the characteristic size and size distribution of chondrules in a natural way. We developed a "cascade model" of the statistics of dense zones and their correlation with gas vorticity. The model incorporates the effects of particle mass loading on the gas and predicts the fractional volume of particle-rich zones which can evolve directly into objects with some physical cohesiveness. We derived threshold conditions (combinations of particle density, clump lengthscale, gas density, and local vorticity) which allow dense clumps to proceed to become actual planetesimals. Combination of these

  7. Vildagliptin and its metabolite M20.7 induce the expression of S100A8 and S100A9 in human hepatoma HepG2 and leukemia HL-60 cells

    PubMed Central

    Asakura, Mitsutoshi; Karaki, Fumika; Fujii, Hideaki; Atsuda, Koichiro; Itoh, Tomoo; Fujiwara, Ryoichi

    2016-01-01

    Vildagliptin is a potent, orally active inhibitor of dipeptidyl peptidase-4 (DPP-4) for the treatment of type 2 diabetes mellitus. It has been reported that vildagliptin can cause hepatic dysfunction in patients. However, the molecular-mechanism of vildagliptin-induced liver dysfunction has not been elucidated. In this study, we employed an expression microarray to determine hepatic genes that were highly regulated by vildagliptin in mice. We found that pro-inflammatory S100 calcium-binding protein (S100) a8 and S100a9 were induced more than 5-fold by vildagliptin in the mouse liver. We further examined the effects of vildagliptin and its major metabolite M20.7 on the mRNA expression levels of S100A8 and S100A9 in human hepatoma HepG2 and leukemia HL-60 cells. In HepG2 cells, vildagliptin, M20.7, and sitagliptin – another DPP-4 inhibitor – induced S100A9 mRNA. In HL-60 cells, in contrast, S100A8 and S100A9 mRNAs were significantly induced by vildagliptin and M20.7, but not by sitagliptin. The release of S100A8/A9 complex in the cell culturing medium was observed in the HL-60 cells treated with vildagliptin and M20.7. Therefore, the parental vildagliptin- and M20.7-induced release of S100A8/A9 complex from immune cells, such as neutrophils, might be a contributing factor of vildagliptin-associated liver dysfunction in humans. PMID:27759084

  8. Vildagliptin and its metabolite M20.7 induce the expression of S100A8 and S100A9 in human hepatoma HepG2 and leukemia HL-60 cells.

    PubMed

    Asakura, Mitsutoshi; Karaki, Fumika; Fujii, Hideaki; Atsuda, Koichiro; Itoh, Tomoo; Fujiwara, Ryoichi

    2016-10-19

    Vildagliptin is a potent, orally active inhibitor of dipeptidyl peptidase-4 (DPP-4) for the treatment of type 2 diabetes mellitus. It has been reported that vildagliptin can cause hepatic dysfunction in patients. However, the molecular-mechanism of vildagliptin-induced liver dysfunction has not been elucidated. In this study, we employed an expression microarray to determine hepatic genes that were highly regulated by vildagliptin in mice. We found that pro-inflammatory S100 calcium-binding protein (S100) a8 and S100a9 were induced more than 5-fold by vildagliptin in the mouse liver. We further examined the effects of vildagliptin and its major metabolite M20.7 on the mRNA expression levels of S100A8 and S100A9 in human hepatoma HepG2 and leukemia HL-60 cells. In HepG2 cells, vildagliptin, M20.7, and sitagliptin - another DPP-4 inhibitor - induced S100A9 mRNA. In HL-60 cells, in contrast, S100A8 and S100A9 mRNAs were significantly induced by vildagliptin and M20.7, but not by sitagliptin. The release of S100A8/A9 complex in the cell culturing medium was observed in the HL-60 cells treated with vildagliptin and M20.7. Therefore, the parental vildagliptin- and M20.7-induced release of S100A8/A9 complex from immune cells, such as neutrophils, might be a contributing factor of vildagliptin-associated liver dysfunction in humans.

  9. First ultraviolet reflectance measurements of several Kuiper Belt objects, Kuiper Belt object satellites, and new ultraviolet measurements of A Centaur

    SciTech Connect

    Stern, S. A.; Schindhelm, E.; Cunningham, N. J.

    2014-05-01

    We observed the 2600-3200 Å (hereafter, mid-UV) reflectance of two Kuiper Belt Objects (KBOs), two KBO satellites, and a Centaur, using the Hubble Space Telescope (HST) Cosmic Origins Spectrograph (COS). Other than measurements of the Pluto system, these constitute the first UV measurements obtained of KBOs, and KBO satellites, and new HST UV measurements of the Centaur 2060 Chiron. We find significant differences among these objects, constrain the sizes and densities of Haumea's satellites, and report the detection of a possible spectral absorption band in Haumea's spectrum near 3050 Å. Comparisons of these objects to previously published UV reflectance measurements of Pluto and Charon are also made here.

  10. A collisional family of icy objects in the Kuiper belt.

    PubMed

    Brown, Michael E; Barkume, Kristina M; Ragozzine, Darin; Schaller, Emily L

    2007-03-15

    The small bodies in the Solar System are thought to have been highly affected by collisions and erosion. In the asteroid belt, direct evidence of the effects of large collisions can be seen in the existence of separate families of asteroids--a family consists of many asteroids with similar orbits and, frequently, similar surface properties, with each family being the remnant of a single catastrophic impact. In the region beyond Neptune, in contrast, no collisionally created families have hitherto been found. The third largest known Kuiper belt object, 2003 EL61, however, is thought to have experienced a giant impact that created its multiple satellite system, stripped away much of an overlying ice mantle, and left it with a rapid rotation. Here we report the discovery of a family of Kuiper belt objects with surface properties and orbits that are nearly identical to those of 2003 EL61. This family appears to be fragments of the ejected ice mantle of 2003 EL61.

  11. Forming the Cold Classical Kuiper Belt in a Light Disk

    NASA Astrophysics Data System (ADS)

    Shannon, Andrew; Wu, Yanqin; Lithwick, Yoram

    2016-02-01

    Large Kuiper Belt objects are conventionally thought to have formed out of a massive planetesimal belt that is a few thousand times its current mass. Such a picture, however, is incompatible with multiple lines of evidence. Here, we present a new model for the conglomeration of Cold Classical Kuiper Belt objects, out of a solid belt only a few times its current mass, or a few per cent of the solid density in a Minimum Mass Solar Nebula. This is made possible by depositing most of the primordial mass in grains of centimeter size or smaller. These grains collide frequently and maintain a dynamically cold belt out of which large bodies grow efficiently: an order-unity fraction of the solid mass can be converted into large bodies, in contrast to the ∼ {10}-3 efficiency in conventional models. Such a light belt may represent the true outer edge of the solar system, and it may have effectively halted the outward migration of Neptune. In addition to the high efficiency, our model can also produce a mass spectrum that peaks at an intermediate size, similar to the observed Cold Classicals, if one includes the effect of cratering collisions. In particular, the observed power-law break observed at ∼ 30 {km} for Cold Classicals, one that has been interpreted as a result of collisional erosion, may be primordial in origin.

  12. Insolation and Resulting Surface Temperatures of the Kuiper-Rudaki Study Region on Mercury.

    NASA Astrophysics Data System (ADS)

    Bauch, Karin E.; Hiesinger, Harald; D'Amore, Mario; Helbert, Jörn; Weinauer, Julia

    2016-04-01

    cold poles along the equator. The region shows smooth plains surrounding crater Rudaki (˜120km), as well as cratered terrain around the prominent crater Kuiper (˜60km) and has been extensively covered by measurements during the MESSENGER mission. Temperatures range from about 100K during the night to 570K (cold pole) and 700K (hot pole) at local noon. The floor of Kuiper crater reaches temperatures of ˜660K at local noon, while those at Rudaki crater are 625K (+/-5K). Due to their higher albedo, the rays of Kuiper crater are about 5K colder than the surrounding regions. These temperature estimates will aid the accurate interpretation of future MERTIS spectra of the region obtained during the BepiColombo mission [10]. References: [1] Hiesinger, H. et al. (2010), PSS 58, 144-165. [2] Helbert, J. et al. (2005), LPSC XXXVI, #1753. [3] Keihm, S.J. and Langseth, M.G. (1973), Proc. Lunar Sci. Conf. 4th, 2503-2513. [4] Lawson, S.L. et al. (2000), JGR 105, E5, 4273-4290. [5] Pieters, C.M. et al. (2009), Science 326, 568-572. [6] Paige, D.A. et al. (2010), Space Sci. Rev 150, 125-160. [7] Bauch, K.E. et al. (2014), PSS 101, 27-36. [8] Vasavada, A. et al. (1999), Icarus 141, 179-193. [9] Solomon, S.C. et al. (2008), Science 321, 59-62. [10] D'Amore et al. (2013), AGU, #P13A-1735.

  13. Continuous gradient temperature Raman spectroscopy of N-6DPA and DHA from -100 to 20°C.

    PubMed

    Broadhurst, C Leigh; Schmidt, Walter F; Kim, Moon S; Nguyen, Julie K; Qin, Jianwei; Chao, Kuanglin; Bauchan, Gary L; Shelton, Daniel R

    2016-10-01

    One of the great unanswered questions with respect to biological science in general is the absolute necessity of docosahexaenoic acid (DHA, 22:6n-3) in fast signal processing tissues. N-6 docosapentaenoic acid (n-6DPA, 22:5n-6), with just one less double bond, group, is fairly abundant in terrestrial food chains yet cannot substitute for DHA. Gradient temperature Raman spectroscopy (GTRS) applies the temperature gradients utilized in differential scanning calorimetry (DSC) to Raman spectroscopy, providing a straightforward technique to identify molecular rearrangements that occur near and at phase transitions. Herein we apply GTRS and DSC to n-6DPA and DHA from -100 to 20°C. 20Mb three-dimensional data arrays with 0.2°C increments and first/second derivatives allowed complete assignment of solid, liquid and transition state vibrational modes, including low intensity/frequency vibrations that cannot be readily analyzed with conventional Raman. N-6DPA and DHA show significant spectral changes with premelting (-33 and -60°C, respectively) and melting (-27 and -44°C, respectively). The CH2(HCCH)CH2 moieties are not identical in the second half of the DHA and DPA structures. DPA has bending (1450cm(-1)) over almost the entire temperature range. In contrast, DHA contains major CH2 twisting (1265cm(-1)) with no noticeable CH2 bending, consistent with a flat helical structure with a small pitch. Further modeling of neuronal membrane phospholipids must take into account torsion present in the DHA structure, which essential in determining whether the lipid chain is configured more parallel or perpendicular to the hydrophilic head group. Copyright © 2016. Published by Elsevier Ireland Ltd.

  14. The Silver locus product Pmel17/gp100/Silv/ME20: controversial in name and in function

    PubMed Central

    Theos, Alexander C.; Truschel, Steven T.; Raposo, Graça; Marks, Michael S.

    2009-01-01

    Summary Mouse coat color mutants have led to the identification of more than 120 genes that encode proteins involved in all aspects of pigmentation, from the regulation of melanocyte development and differentiation to the transcriptional activation of pigment genes, from the enzymatic formation of pigment to the control of melanosome biogenesis and movement [Bennett and Lamoreux (2003) Pigment Cell Res. 16, 333]. One of the more perplexing of the identified mouse pigment genes is encoded at the Silver locus, first identified by Dunn and Thigpen [(1930) J. Heredity 21, 495] as responsible for a recessive coat color dilution that worsened with age on black backgrounds. The product of the Silver gene has since been discovered numerous times in different contexts, including the initial search for the tyrosinase gene, the characterization of major melanosome constituents in various species, and the identification of tumor-associated antigens from melanoma patients. Each discoverer provided a distinct name: Pmel17, gp100, gp95, gp85, ME20, RPE1, SILV and MMP115 among others. Although all its functions are unlikely to have yet been fully described, the protein clearly plays a central role in the biogenesis of the early stages of the pigment organelle, the melanosome, in birds, and mammals. As such, we will refer to the protein in this review simply as pre-melanosomal protein (Pmel). This review will summarize the structural and functional aspects of Pmel and its role in melanosome biogenesis. PMID:16162173

  15. Layered Model for Radiation-Induced Chemical Evolution of Icy Surface Composition and Dynamics on Kuiper Belt and Oort Cloud Bodies

    NASA Technical Reports Server (NTRS)

    Cooper, John F.; Richardson, John D.

    2010-01-01

    The diversity of albedos and surface colors on observed Kuiper Belt and Inner Oort Cloud objects remains to be explained in terms of competition between primordial intrinsic versus exogenic drivers of surface and near-surface evolution. Earlier models have attempted without success to attribute this diversity to the relations between surface radiolysis from cosmic ray irradiation and gardening by meteoritic impacts. A more flexible approach considers the different depth-dependent radiation profiles produced by low-energy plasma, suprathermal, and maximally penetrating charged particles of the heliospheric and local interstellar radiation environment. Generally red objects of the dynamically cold (low inclination, circular orbit) Classical Kuiper Belt might be accounted for from erosive effects of plasma ions and reddening effects of high energy cosmic ray ions, while suprathermal keV-MeV ions could alternatively produce more color neutral surfaces. The deepest layer of more pristine ice can be brought to the surface from meter to kilometer depths by larger impact events and potentially by cryovolcanic activity. The bright surfaces of some larger objects, e.g. Eris, suggest ongoing resurfacing activity. Cycles of atmospheric formation and surface freezeout can further account for temporal variation as observed on Pluto. The diversity of causative processes must therefore be understood to account for observationally apparent diversities of the object surfaces.

  16. Sub-kilometer Numerical Weather Prediction in complex urban areas

    NASA Astrophysics Data System (ADS)

    Leroyer, S.; Bélair, S.; Husain, S.; Vionnet, V.

    2013-12-01

    A Sub-kilometer atmospheric modeling system with grid-spacings of 2.5 km, 1 km and 250 m and including urban processes is currently being developed at the Meteorological Service of Canada (MSC) in order to provide more accurate weather forecasts at the city scale. Atmospheric lateral boundary conditions are provided with the 15-km Canadian Regional Deterministic Prediction System (RDPS). Surface physical processes are represented with the Town Energy Balance (TEB) model for the built-up covers and with the Interactions between the Surface, Biosphere, and Atmosphere (ISBA) land surface model for the natural covers. In this study, several research experiments over large metropolitan areas and using observational networks at the urban scale are presented, with a special emphasis on the representation of local atmospheric circulations and their impact on extreme weather forecasting. First, numerical simulations are performed over the Vancouver metropolitan area during a summertime Intense Observing Period (IOP of 14-15 August 2008) of the Environmental Prediction in Canadian Cities (EPiCC) observational network. The influence of the horizontal resolution on the fine-scale representation of the sea-breeze development over the city is highlighted (Leroyer et al., 2013). Then severe storms cases occurring in summertime within the Greater Toronto Area (GTA) are simulated. In view of supporting the 2015 PanAmerican and Para-Pan games to be hold in GTA, a dense observational network has been recently deployed over this region to support model evaluations at the urban and meso scales. In particular, simulations are conducted for the case of 8 July 2013 when exceptional rainfalls were recorded. Leroyer, S., S. Bélair, J. Mailhot, S.Z. Husain, 2013: Sub-kilometer Numerical Weather Prediction in an Urban Coastal Area: A case study over the Vancouver Metropolitan Area, submitted to Journal of Applied Meteorology and Climatology.

  17. 20 CFR 668.100 - What is the purpose of the programs established to serve Native American peoples (INA programs...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...? 668.100 Section 668.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF... Policies § 668.100 What is the purpose of the programs established to serve Native American peoples (INA... support comprehensive employment and training activities for Indian, Alaska Native and Native...

  18. 20 CFR 668.100 - What is the purpose of the programs established to serve Native American peoples (INA programs...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...? 668.100 Section 668.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF... Purposes and Policies § 668.100 What is the purpose of the programs established to serve Native American... programs is to support comprehensive employment and training activities for Indian, Alaska Native...

  19. 20 CFR 668.100 - What is the purpose of the programs established to serve Native American peoples (INA programs...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...? 668.100 Section 668.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF... Purposes and Policies § 668.100 What is the purpose of the programs established to serve Native American... programs is to support comprehensive employment and training activities for Indian, Alaska Native...

  20. 20 CFR 668.100 - What is the purpose of the programs established to serve Native American peoples (INA programs...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...? 668.100 Section 668.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF... Purposes and Policies § 668.100 What is the purpose of the programs established to serve Native American... programs is to support comprehensive employment and training activities for Indian, Alaska Native...

  1. New features in the structure of the classical Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Gladman, Brett; Bannister, Michele T.; Alexandersen, Mike; Chen, Ying-Tung; Gwyn, Stephen; Kavelaars, J. J.; Petit, Jean-Marc; Volk, Kathryn; OSSOS Collaboration

    2016-10-01

    We report fascinating new dynamical structures emerging from a higher precision view of the classical Kuiper belt (the plentiful non-resonant orbits with semimajor axes in roughly the a=35-60 au range). The classical Kuiper Belt divides into multiple sub-populations: an 'inner' classical belt (a small group of non-resonant objects with a<39.4 au where the 3:2 resonance is located), an abundant 'main' classical belt (between the 3:2 and the 2:1 at a=47.4 au), and a difficult to study outer classical belt beyond the 2:1. We examine the dynamical structure, as precisely revealed in the detections from OSSOS (the Outer Solar System Origin's Survey); the data set is of superb quality in terms of orbital element and numbers of detections (Kavelaars et al, this meeting).The previous CFEPS survey showed that the main classical belt requires a complex dynamical substructure that goes beyond a simple 'hot versus cold' division based primarily on orbital inclination; the 'cold' inclination component requires two sub-components in the semimajor axis and perihelion distance q space (Petit et al 2011). CFEPS modelled this as a 'stirred' component present at all a=40-47 AU semimajor axes, with a dense superposed 'kernel' near a=44 AU at low eccentricity; the first OSSOS data release remained consistent with this (Bannister et al 2016). As with the main asteroid belt, as statistics and orbital quality improve we see additional significant substructure emerging in the classical belt's orbital distribution.OSSOS continues to add evidence that the cold stirred component extends smoothly beyond the 2:1 (Bannister et al 2016). Unexpectedly, the data also reveal the clear existence of a paucity of orbits just beyond the outer edge of the kernel; there are significantly fewer TNOs in the narrow semimajor axis band from a=44.5-45.0 AU. This may be related to the kernel population's creation, or it may be an independent feature created by planet migration as resonances moved in the

  2. 20 CFR 1002.100 - Does the five-year service limit include all absences from an employment position that are...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Does the five-year service limit include all absences from an employment position that are related to service in the uniformed services? 1002.100 Section 1002.100 Employees' Benefits OFFICE OF THE ASSISTANT SECRETARY FOR VETERANS' EMPLOYMENT AND TRAINING SERVICE, DEPARTMENT OF LABOR...

  3. 20 CFR 669.100 - What is the purpose of the National Farmworker Jobs Program (NFJP) and the other services and...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false What is the purpose of the National Farmworker Jobs Program (NFJP) and the other services and activities established under WIA section 167? 669.100 Section 669.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR NATIONAL FARMWORKER JOBS PROGRAM UNDER TITLE I...

  4. 20 CFR 669.100 - What is the purpose of the National Farmworker Jobs Program (NFJP) and the other services and...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false What is the purpose of the National Farmworker Jobs Program (NFJP) and the other services and activities established under WIA section 167? 669.100 Section 669.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) NATIONAL FARMWORKER JOBS PROGRAM...

  5. 20 CFR 669.100 - What is the purpose of the National Farmworker Jobs Program (NFJP) and the other services and...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What is the purpose of the National Farmworker Jobs Program (NFJP) and the other services and activities established under WIA section 167? 669.100 Section 669.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR NATIONAL FARMWORKER JOBS PROGRAM UNDER TITLE I...

  6. 20 CFR 669.100 - What is the purpose of the National Farmworker Jobs Program (NFJP) and the other services and...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false What is the purpose of the National Farmworker Jobs Program (NFJP) and the other services and activities established under WIA section 167? 669.100 Section 669.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) NATIONAL FARMWORKER JOBS PROGRAM...

  7. Precise Astrometry for Predicting Kuiper Belt Object Occultations

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott; Person, Michael; Zuluaga, Carlos; Bosh, Amanda

    2013-02-01

    Occultations by Kuiper Belt objects remain elusive events, requiring precision astrometry for these faint bodies in the outer solar system. Routine astrometry provides data that are crucial for our KBO ephemeris correction models, which then allow accurate shadow track predictions. Through the occultation events the diameters, possible companions and tenuous atmospheres around these objects will be explored by examining how the light from the star varies as the KBO passes in front of it. This is a powerful way to determine the physical characteristics of the KBOs. We propose to obtain very precise astrometry on 10 of the brightest known KBOs to determine more accurate orbits and thus reliable occultation predictions. We also require telescope time to obtain precise astrometry on possible stars that will be occulted by a KBO in the future.

  8. Microlensing by Kuiper, Oort, and Free-Floating Planets

    NASA Astrophysics Data System (ADS)

    Gould, Andrew

    2016-08-01

    Microlensing is generally thought to probe planetary systems only out to a few Einstein radii. Microlensing events generated by bound planets beyond about 10 Einstein radii generally do not yield any trace of their hosts, and so would be classified as free floating planets (FFPs). I show that it is already possible, using adaptive optics (AO), to constrain the presence of potential hosts to FFP candidates at separations comparable to the Oort Cloud. With next-generation telescopes, planets at Kuiper-Belt separations can be probed. Next generation telescopes will also permit routine vetting for all FFP candidates, simply by obtaining second epochs 4-8 years after the event.At present, the search for such hosts is restricted to within the ``confusion limit'' of θ_\\confus ˜ 0.25'' but future WFIRST (Wide Field Infrared Survey Telescope) observations will allow one to probe beyond this confusion limit as well.

  9. Pluto/Kuiper Missions with Advanced Electric Propulsion and Power

    NASA Technical Reports Server (NTRS)

    Oleson, S. R.; Patterson, M. J.; Schrieber, J.; Gefert, L. P.

    2001-01-01

    In response to a request by NASA Code SD Deep Space Exploration Technology Program, NASA Glenn Research center performed a study to identify advanced technology options to perform a Pluto/Kuiper mission without depending on a 2004 Jupiter Gravity Assist, but still arriving before 2020. A concept using a direct trajectory with small, sub-kilowatt ion thrusters and Stirling radioisotope power system was shown to allow the same or smaller launch vehicle class (EELV) as the chemical 2004 baseline and allow launch in any year and arrival in the 2014 to 2020 timeframe. With the nearly constant power available from the radioisotope power source such small ion propelled spacecraft could explore many of the outer planetary targets. Such studies are already underway. Additional information is contained in the original extended abstract.

  10. Digital control of the Kuiper Airborne Observatory telescope

    NASA Technical Reports Server (NTRS)

    Mccormack, Ann C.; Snyder, Philip K.

    1989-01-01

    The feasibility of using a digital controller to stabilize a telescope mounted in an airplane is investigated. The telescope is a 30 in. infrared telescope mounted aboard a NASA C-141 aircraft known as the Kuiper Airborne Observatory. Current efforts to refurbish the 14-year-old compensation system have led to considering a digital controller. A typical digital controller is modeled and added into the telescope system model. This model is simulated on a computer to generate the Bode plots and time responses which determine system stability and performance parameters. Important aspects of digital control system hardware are discussed. A summary of the findings shows that a digital control system would result in satisfactory telescope performance.

  11. Pluto/Kuiper Missions with Advanced Electric Propulsion and Power

    NASA Technical Reports Server (NTRS)

    Oleson, S. R.; Patterson, M. J.; Schrieber, J.; Gefert, L. P.

    2001-01-01

    In response to a request by NASA Code SD Deep Space Exploration Technology Program, NASA Glenn Research center performed a study to identify advanced technology options to perform a Pluto/Kuiper mission without depending on a 2004 Jupiter Gravity Assist, but still arriving before 2020. A concept using a direct trajectory with small, sub-kilowatt ion thrusters and Stirling radioisotope power system was shown to allow the same or smaller launch vehicle class (EELV) as the chemical 2004 baseline and allow launch in any year and arrival in the 2014 to 2020 timeframe. With the nearly constant power available from the radioisotope power source such small ion propelled spacecraft could explore many of the outer planetary targets. Such studies are already underway. Additional information is contained in the original extended abstract.

  12. Realistic survey simulations for kilometer class near Earth objects

    NASA Astrophysics Data System (ADS)

    Moon, Hong-Kyu; Byun, Yong-Ik; Raymond, Sean N.; Spahr, Timothy

    2008-01-01

    We present a new Near Earth Object (NEO) survey simulator which incorporates the four-dimensional population model of 4668 NEOs [Bottke, W.F., Morbidelli, A., Jedicke, R., Petit, J.-M., Levison, H.F., Michel, P., Metcalfe, T.S., 2002. Icarus 156, 399-433] and the observing strategies of most asteroid search programs. With the recent expansion of survey capabilities, previous simulators focused on a specific survey facility are no longer useful in predicting the future detection rates. Our simulation is a superposition of simplified search patterns adopted by all major wide-field surveys in operation in both hemispheres. We defined five different simulation periods to follow the evolution of survey efficiencies reflecting changes in either search volume as a result of upgrades of telescopes and instruments or in observing schedules. The simulator makes remarkably good reproductions of actual survey results as of December 2005, not only the total number of detections but also (a,e,i,H) (' H' means absolute magnitude of an asteroid) distributions. An extended experiment provides excellent predictions for discovery statistics of NEOs ( H<18) reported to the Minor Planet Center in 2006. These support that our simulator is a plausible approximation of real surveys. We further confirm that, with the Bottke et al. [Bottke, W.F., Morbidelli, A., Jedicke, R., Petit, J.-M., Levison, H.F., Michel, P., Metcalfe, T.S., 2002. Icarus 156, 399-433] population model and present survey capability, the 90% completeness level of kilometer-sized NEOs will be achieved by 2010 or 2011. However, about 8% of the kilometer-sized or larger NEOs would remain undetected even after 10-year operation (2007-2016) of all current NEO survey facilities. They are apparently faint, with orbits characterized by large semimajor axis and higher eccentricity; these "hardest-to-find" objects tend to elude the search volume of existing NEO survey facilities. Our simulation suggests that 15% of undetectable

  13. Formation of High Mass Hydrocarbons on Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Jones, Brant M.; Bennett, C.; Gu, X.; Kaiser, R.

    2012-10-01

    We present recent results from the newly established W.M. Keck Research Laboratory in Astrochemistry regarding the formation of high molecular weight ( C15) hydrocarbons starting from pure, simple hydrocarbons ices upon interaction of these ices with ionizing radiation: methane (CH4), ethane (C2H6), propane (C3H8) and n-butane (C4H10). Specifically, we have utilized a novel application of reflection time-of-flight mass spectrometry coupled with soft vacuum ultraviolet photoionization to observe the nature of high mass hydro- carbons as a function of their respective sublimation temperature. The Kuiper Belt is estimated to consist of over 70,000 icy bodies, which extend beyond the orbit of Neptune at 30 AU. These bodies are thought to have maintained low temperatures (30-50 K) since the formation of the solar system and are regarded as frozen relics that may preserve a record of the primitive volatiles from which the solar system formed. In particular, methane has been detected on the surfaces of Sedna, Quaoar, Triton (thought to be a captured KBO) and Pluto along with ethane being tentatively assigned to on Quaoar, Pluto, and Orcus. The surfaces of these bodies have undergone 4.5 Gyr of chemical processing due to ionizing radiation from the solar wind and Galactic Cosmic Radiation. Our research has been focused on trying to understand how these ices have evolved over the age of our solar system by simulating the chemical processing via ionizing radiation in an ultrahigh vacuum chamber coupled with a variety of optical analytical spectroscopies (FT-IR, Raman, UV-Vis) and gas phase mass spectroscopy. Our results indicate that larger, more complex hydrocarbons up to C15 are formed easily under conditions relevant to the environment of Kuiper Belt Objects which may help elucidate part of the puzzle regarding the ‘colors’ of these objects along with the formation of carbonaceous material throughout the interstellar medium.

  14. Kilometer scale primary objective telescope with no moving parts

    NASA Astrophysics Data System (ADS)

    Ditto, Thomas

    2003-02-01

    he author proposes the use of a diffraction grating as a primary collector in a very large ground-based telescope. The grating is to be placed at grazing exodus relative to a secondary receiver and will have considerable length relative to width. Collector areas of square kilometers are being considered. Large collectors pose problems for ordinary telescopes, but with the proposed telescope, the rotation of the earth is the only requisite motion. Other than the earth itself, there are no moving parts. In the course of a night's observation, a plurality of stars within a narrow band of right ascension would yield detailed spectra. We anticipate that while acquiring the spectra of a star, the instrument would also acquire the spectra of any planetary system around it, because the high inherent resolving power of the instrument can measure subtle Doppler shifts, and the collecting area is sufficiently large to detect spectra from planets in the full glare of the star that illuminates them. Where signature spectra are available, planets can by typed, including earth-like planets which can be distinguished by their unique spectra and their implied surface temperature as inferred from orbit diameter. Our study investigates several grating arrangements, types and efficiencies including some using reflection gratings and one with a transmission grating in an evanescent mode. We explore options for grating fabrication and mounting

  15. The Square Kilometer Array: Key Science and Technology Development

    NASA Astrophysics Data System (ADS)

    Cordes, J. M.

    2005-12-01

    This paper summarizes the science goals for the Square Kilometer Array and its possible implementation. The SKA is the next generation radio telescope that will revolutionize our knowledge of the universe. The SKA will enable massive surveys of many kinds at meter and centimeter wavelengths. It is being designed to probe fundamental questions in physics, such as the nature of dark energy and dark matter and the properties of gravity in the strong-field limit. The SKA will also lead to a better understanding of complexity in the universe, viz. the origins of magnetic fields, galaxies, stars, planets and life. Currently the purpose and specifications of the SKA are defined in terms of five key science areas, which are summarized here, along with the enormous discovery space that will be opened up by the SKA. The key ``axes of discovery'' for the SKA include a huge boost in sensitivity combined with high angular resolution and wide field of view (FoV). These innovations, combined with those developed in radio astronomy contexts over the last few decades, will open new windows to the universe. It will also provide numerous synergistic studies with telescopes that span the electromagnetic spectrum as well as with non-electromagnetic telescopes, especially gravitational wave detectors.

  16. TAOS: Taiwan-American Occultation Survey of Comet-Sized Objects in the Kuiper Belt

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack; DeVincenzi, Donald (Technical Monitor)

    1999-01-01

    Several dozen minor planets with radii greater than 100 km have been detected beyond Neptune using large telescopes. The TAOS project is to measure directly the number of these KBOs (Kuiper Belt Objects) down to the typical size of cometary nuclei (a few km) and out as far as approximately 100 AU from the Sun. Because of their large distance, small sizes and presumed low albedos, these target objects are extremely faint. Three 50 cm wide field robotic telescopes with 2048 x 2048 CCD cameras will be deployed along a 7 km east-west baseline in or near Jade Mountain National Park in Taiwan. They will monitor approximately 3000 stars for occultations by KBOs in a coincidence mode, so that the sequence and timing of the three separate blinkings can be used to distinguish real events from false alarms. Follow-up imaging observations using large telescopes will yield albedos and orbits for some of the larger objects detected by TAOS. A fourth telescope on a north-south spur to refine the size information on occulting GABON is also being contemplated.

  17. TAOS: Taiwan-American Occultation Survey of Comet-Sized Objects in the Kuiper Belt

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack; DeVincenzi, Donald (Technical Monitor)

    1999-01-01

    Several dozen minor planets with radii greater than 100 km have been detected beyond Neptune using large telescopes. The TAOS project is to measure directly the number of these KBOs (Kuiper Belt Objects) down to the typical size of cometary nuclei (a few km) and out as far as approximately 100 AU from the Sun. Because of their large distance, small sizes and presumed low albedos, these target objects are extremely faint. Three 50 cm wide field robotic telescopes with 2048 x 2048 CCD cameras will be deployed along a 7 km east-west baseline in or near Jade Mountain National Park in Taiwan. They will monitor approximately 3000 stars for occultations by KBOs in a coincidence mode, so that the sequence and timing of the three separate blinkings can be used to distinguish real events from false alarms. Follow-up imaging observations using large telescopes will yield albedos and orbits for some of the larger objects detected by TAOS. A fourth telescope on a north-south spur to refine the size information on occulting GABON is also being contemplated.

  18. Debris On Herschel: An Overview Of The Search For Kuiper Belts Around The Nearest Stars

    NASA Astrophysics Data System (ADS)

    Butner, Harold M.; Matthews, B.; DEBRIS Survey Team

    2010-01-01

    Building on the recent success of Spitzer in detecting debris disks around the nearest stars and the SCUBA instrument at the JCMT in imaging cold disks, DEBRIS (Disk Emission via a Bias-free Reconnaissance in the Infrared/Submillimetre) is an open time key project on Herschel which aims to conduct an unbiased statistical survey for debris disks around the nearest stars to unprecedented mass limits. The survey is driven by 100 and 160 micron observations and is flux-limited. The sample is drawn from a database of nearby stars of spectral types A0 through M7 and totals 446 primaries, 348 of which will be observed by the DEBRIS team and 98 of which are covered by another project, the DUNES (DUst disks around NEarby Stars) team. Each target will be observed to a 100 micron rms of 1.2 mJy, allowing the detection of disks with dust masses comparable that of our own Kuiper belt towar the nearest stars. The superior resolution of Herschel should provide resolved images of many of the closest disks, and even our most distant disks may be resolvable. We will discuss the current state of debris disk research and highlight the areas in which Herschel will make the biggest impacts: establishing the true incidence of debris disks; characterizing the debris disk population, resolving disks and modeling their structure for evidence of long period planets; and the placing of our own Solar System in context

  19. The DEBRIS Project: Searching for Kuiper Belts around the Nearest Stars with Herschel

    NASA Astrophysics Data System (ADS)

    Matthews, Brenda

    Building on the recent success of Spitzer in detecting debris disks around the nearest stars and the SCUBA instrument at the JCMT in imaging cold disks, DEBRIS (Disk Emission via a Bias-free Reconnaissance in the Infrared/Submillimetre) is an open time key project on Herschel which aims to conduct an unbiased statistical survey for debris disks around the nearest stars to unprecedented mass limits. The survey is driven by 100 and 160 micron observations and is flux-limited. The sample is drawn from a database of nearby stars (Phillips et al. in prep) of spectral types A0 through M7 and totals 446 primaries, 348 of which will be observed by the DEBRIS team and 98 of which are covered by another the DUNES (DUst disks around NEarby Stars) team. Each target will be observed to a 100 micron rms of 1.2 mJy, allowing the detection of disks with dust masses comparable that of our own Kuiper belt towar the nearest stars. The superior resolution of Herschel should provide resolved images of many of the closest disks, and even our most distant disks may be resolvable. I will discuss the current state of debris disk research and highlight the areas in which Herschel will make the biggest impacts: establishing the true incidence of debris disks; characterizing the debris disk population, resolving disks and modeling their structure for evidence of long period planets; and the placing of our own Solar System in context.

  20. 20 CFR 664.620 - Do the core indicators described in 20 CFR 666.100(a)(3) apply to participation in summer...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Do the core indicators described in 20 CFR... I OF THE WORKFORCE INVESTMENT ACT Summer Employment Opportunities § 664.620 Do the core indicators... section 136(b)(2) (A)(ii) and(B) provides specific core indicators of performance for youth, and...

  1. 20 CFR 664.620 - Do the core indicators described in 20 CFR 666.100(a)(3) apply to participation in summer...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Do the core indicators described in 20 CFR... I OF THE WORKFORCE INVESTMENT ACT Summer Employment Opportunities § 664.620 Do the core indicators... section 136(b)(2) (A)(ii) and(B) provides specific core indicators of performance for youth, and...

  2. Kuipers conducts a leak check in the SM Transfer Tunnel/ATV Vestibule

    NASA Image and Video Library

    2012-03-29

    ISS030-E-177373 (29 March 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, conducts a leak check in the Zvezda Service Module transfer tunnel/ATV vestibule of the International Space Station.

  3. Kuipers performs routine in-flight maintenance on EMU in the A/L

    NASA Image and Video Library

    2012-03-13

    ISS030-E-148284 (13 March 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, performs routine in-flight maintenance on Extravehicular Mobility Unit (EMU) equipment in the Quest airlock of the International Space Station.

  4. Kuipers retrieves a food locker at mealtime in the SM during EXP 8 / EXP 9

    NASA Image and Video Library

    2004-04-22

    ISS008-E-22009 (22 April 2004) --- European Space Agency (ESA) astronaut Andre Kuipers of the Netherlands is pictured near food storage containers in the Zvezda Service Module of the International Space Station (ISS).

  5. Kuipers works with DSC Hardware in the U.S. Laboratory

    NASA Image and Video Library

    2012-01-16

    ISS030-E-155917 (16 Jan. 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, prepares to place Diffusion Soret Coefficient (DSC) hardware in stowage containers in the Destiny laboratory of the International Space Station.

  6. The formation of the Kuiper belt by the outward transport of bodies during Neptune's migration.

    PubMed

    Levison, Harold F; Morbidelli, Alessandro

    2003-11-27

    The 'dynamically cold Kuiper belt' consists of objects on low-inclination orbits between approximately 40 and approximately 50 au from the Sun. It currently contains material totalling less than a tenth the mass of the Earth, which is surprisingly low because, according to accretion models, the objects would not have grown to their present size unless the cold Kuiper belt originally contained tens of Earth masses of solids. Although several mechanisms have been proposed to produce the observed mass depletion, they all have significant limitations. Here we show that the objects currently observed in the dynamically cold Kuiper belt were most probably formed within approximately 35 au and were subsequently pushed outward by Neptune's 1:2 mean motion resonance during its final phase of migration. Combining our mechanism with previous work, we conclude that the entire Kuiper belt formed closer to the Sun and was transported outward during the final stages of planet formation.

  7. Expedition 30 crew member and ESA astronaut Andre Kuipers training in SSTF

    NASA Image and Video Library

    2011-09-01

    DATE: 9-1-11 LOCATION: Bldg. 5south, SSTF SUBJECT: Expedition 30 crew member and ESA astronaut Andre Kuipers training in SSTF near Columbia module on laptops with trainer Michaela Benda. PHOTOGRAPHER: Lauren Harnett

  8. Kuipers watches food and drink packets float in the Node 1

    NASA Image and Video Library

    2012-01-30

    ISS030-E-166649 (30 Jan. 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, is pictured near food and beverage packages floating freely in the Unity node of the International Space Station.

  9. Comparative Indicators of Education in the United States and Other G-20 Countries: 2015. NCES 2016-100

    ERIC Educational Resources Information Center

    Stephens, Maria; Warren, Laura K.; Harner, Ariana L.

    2015-01-01

    The "Comparative Indicators of Education" report series has been published on a biennial basis since it began in 2002, although this year's is the first to expand its focus to the G-20 countries, having previously been focused on the G-8 countries. "Comparative Indicators of Education in the United States and Other G-20 Countries:…

  10. Structure and Evolution of Kuiper Belt Objects and Dwarf Planets

    NASA Astrophysics Data System (ADS)

    McKinnon, W. B.; Prialnik, D.; Stern, S. A.; Coradini, A.

    Kuiper belt objects (KBOs) accreted from a mélange of volatile ices, carbonaceous matter, and rock of mixed interstellar and solar nebular provenance. The transneptunian region, where this accretion took place, was likely more radially compact than today. This and the influence of gas drag during the solar nebula epoch argue for more rapid KBO accretion than usually considered. Early evolution of KBOs was largely the result of heating due to radioactive decay, the most important potential source being 26Al, whereas long-term evolution of large bodies is controlled by the decay of U, Th, and 40K. Several studies are reviewed dealing with the evolution of KBO models, calculated by means of one-dimensional numerical codes that solve the heat and mass balance equations. It is shown that, depending on parameters (principally rock content and porous conductivity), KBO interiors may have reached relatively high temperatures. The models suggest that KBOs likely lost ices of very volatile species during early evolution, whereas ices of less-volatile species should be retained in cold, less-altered subsurface layers. Initially amorphous ice may have crystallized in KBO interiors, releasing volatiles trapped in the amorphous ice, and some objects may have lost part of these volatiles as well. Generally, the outer layers are far less affected by internal evolution than the inner part, which in the absence of other effects (such as collisions) predicts a stratified composition and altered porosity distribution. Kuiper belt objects are thus unlikely to be "the most pristine objects in the solar system," but they do contain key information as to how the early solar system accreted and dynamically evolved. For large (dwarf planet) KBOs, long-term radiogenic heating alone may lead to differentiated structures -- rock cores, ice mantles, volatile-ice-rich "crusts," and even oceans. Persistence of oceans and (potential) volcanism to the present day depends strongly on body size and

  11. Formation of High Mass Hydrocarbons on Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Jones, B. M.; Bennett, C.; Gu, X.; Kaiser, R. I.

    2012-12-01

    Recent results from the newly established W.M. Keck Research Laboratory in Astrochemistry are presented regarding the formation of high molecular weight (~ C15) hydrocarbons starting from pure, simple saturated hydrocarbons ices: methane (CH4), ethane (C2H6), propane (C3H8) and n-butane (C4H10) upon the interaction of these ices with ionizing radiation. Specifically, we have utilized a novel application of reflection time-of-flight mass spectrometry coupled with soft vacuum ultraviolet photoionization to observe the sublimation of the high mass hydrocarbons as a function of temperature. The Kuiper Belt is estimated to consist of over 70,000 icy bodies, which extend beyond the orbit of Neptune at 30 AU. These bodies are believed to have maintained low temperatures (30-50 K) since the formation of the solar system and are often regarded as frozen relics that may preserve a record of the primitive volatiles from which the solar system formed. In particular, methane has been detected on the surfaces of Sedna, Quaoar, Triton (thought to be a captured KBO) and Pluto along with ethane being tentatively assigned to on Quaoar, Pluto, and Orcus. Throughout the past 4.5 billion years, these surfaces have undergone significant chemical processing due to the barrage of ionizing radiation from solar wind and background Galactic Cosmic Rays. The main focus of our research has been elucidating how the outer planetary icy bodies have evolved over the age of the solar system by simulating the chemical changes induced from ionizing radiation in an ultrahigh vacuum chamber. These changes are monitored with a variety of optical analytical spectroscopies (FT-IR, Raman, UV-Vis) and gas phase mass spectroscopy coupled with soft vacuum ultraviolet photoionization of the subliming products at 10.5 eV. Our results indicate that larger, more complex hydrocarbons up to C15 are formed easily under conditions relevant to the environment of Kuiper Belt Objects which may help elucidate part of the

  12. Resolution dependence of deep convections in a global simulation from over 10-kilometer to sub-kilometer grid spacing

    NASA Astrophysics Data System (ADS)

    Kajikawa, Yoshiyuki; Miyamoto, Yoshiaki; Yoshida, Ryuji; Yamaura, Tsuyoshi; Yashiro, Hisashi; Tomita, Hirofumi

    2016-12-01

    The success of sub-kilometer global atmospheric simulation opens the door for resolving deep convections, which are fundamental elements of cloudy disturbances that drive global circulation. A previous study found that the essential change in the simulated convection properties occurred at a grid spacing of about 2 km as a global mean. In grid-refinement experiments, we conducted further comprehensive analysis of the global-mean state and the characteristics of deep convection, to clarify the difference of the essential change by location and environment. We found that the essential change in convection properties was different in the location and environment for each cloudy disturbance. The convections over the tropics show larger resolution dependence than convections over mid-latitudes, whereas no significant difference was found in convections over land or ocean. Furthermore, convections over cloudy disturbances [(i.e., Madden-Julian oscillation (MJO), tropical cyclones (TCs)] show essential change of convection properties at about 1 km grid spacing, suggesting resolution dependence. As a result, convections not categorized as cloudy disturbances make a large contribution to the global-mean convection properties. This implies that convections in disturbances are largely affected organization processes and hence have more horizontal resolution dependence. In contrast, other categorized convections that are not involved in major cloudy disturbances show the essential change at about 2 km grid spacing. This affects the latitude difference of the resolution dependence of convection properties and hence the zonal-mean outgoing longwave radiation (OLR). Despite the diversity of convection properties, most convections are resolved at less than 1 km grid spacing. In the future, longer integration of global atmosphere, to 0.87 km grid spacing, will stimulate significant discussion about the interaction between the convections and cloudy disturbances.

  13. Nature or nurture of coplanar Tatooines: the aligned circumbinary Kuiper belt analogue around HD 131511

    NASA Astrophysics Data System (ADS)

    Kennedy, Grant M.

    2015-02-01

    A key discovery of the Kepler mission is of the circumbinary planets known as `Tatooines', which appear to be well aligned with their host stars' orbits. Whether this alignment is due to initially coplanar circumbinary planet-forming discs (i.e. nature), or subsequent alignment of initially misaligned discs by warping the inner disc or torquing the binary (i.e. nurture), is not known. Tests of which scenario dominates may be possible by observing circumbinary Kuiper belt analogues (`debris discs'), which trace the plane of the primordial disc. Here, the 140 au diameter circumbinary debris disc around HD 131511 is shown to be aligned to within 10° of the plane of the near edge-on 0.2 au binary orbit. The stellar equator is also consistent with being in this plane. If the primordial disc was massive enough to pull the binary into alignment, this outcome should be common and distinguishing nature versus nurture will be difficult. However, if only the inner disc becomes aligned with the binary, the HD 131511 system was never significantly misaligned. Given an initial misalignment, the ˜ Gyr main-sequence lifetime of the star allows secular perturbations to align the debris disc out to 100 au at the cost of an increased scaleheight. The observed debris disc scaleheight limits any misalignment to less than 25°. With only a handful known, many more such systems need to be characterized to help test whether the alignment of circumbinary planets is nature or nurture.

  14. Growth of asteroids, planetary embryos, and Kuiper belt objects by chondrule accretion

    PubMed Central

    Johansen, Anders; Low, Mordecai-Mark Mac; Lacerda, Pedro; Bizzarro, Martin

    2015-01-01

    Chondrules are millimeter-sized spherules that dominate primitive meteorites (chondrites) originating from the asteroid belt. The incorporation of chondrules into asteroidal bodies must be an important step in planet formation, but the mechanism is not understood. We show that the main growth of asteroids can result from gas drag–assisted accretion of chondrules. The largest planetesimals of a population with a characteristic radius of 100 km undergo runaway accretion of chondrules within ~3 My, forming planetary embryos up to Mars’s size along with smaller asteroids whose size distribution matches that of main belt asteroids. The aerodynamical accretion leads to size sorting of chondrules consistent with chondrites. Accretion of millimeter-sized chondrules and ice particles drives the growth of planetesimals beyond the ice line as well, but the growth time increases above the disc lifetime outside of 25 AU. The contribution of direct planetesimal accretion to the growth of both asteroids and Kuiper belt objects is minor. In contrast, planetesimal accretion and chondrule accretion play more equal roles in the formation of Moon-sized embryos in the terrestrial planet formation region. These embryos are isolated from each other and accrete planetesimals only at a low rate. However, the continued accretion of chondrules destabilizes the oligarchic configuration and leads to the formation of Mars-sized embryos and terrestrial planets by a combination of direct chondrule accretion and giant impacts. PMID:26601169

  15. Growth of asteroids, planetary embryos, and Kuiper belt objects by chondrule accretion.

    PubMed

    Johansen, Anders; Low, Mordecai-Mark Mac; Lacerda, Pedro; Bizzarro, Martin

    2015-04-01

    Chondrules are millimeter-sized spherules that dominate primitive meteorites (chondrites) originating from the asteroid belt. The incorporation of chondrules into asteroidal bodies must be an important step in planet formation, but the mechanism is not understood. We show that the main growth of asteroids can result from gas drag-assisted accretion of chondrules. The largest planetesimals of a population with a characteristic radius of 100 km undergo runaway accretion of chondrules within ~3 My, forming planetary embryos up to Mars's size along with smaller asteroids whose size distribution matches that of main belt asteroids. The aerodynamical accretion leads to size sorting of chondrules consistent with chondrites. Accretion of millimeter-sized chondrules and ice particles drives the growth of planetesimals beyond the ice line as well, but the growth time increases above the disc lifetime outside of 25 AU. The contribution of direct planetesimal accretion to the growth of both asteroids and Kuiper belt objects is minor. In contrast, planetesimal accretion and chondrule accretion play more equal roles in the formation of Moon-sized embryos in the terrestrial planet formation region. These embryos are isolated from each other and accrete planetesimals only at a low rate. However, the continued accretion of chondrules destabilizes the oligarchic configuration and leads to the formation of Mars-sized embryos and terrestrial planets by a combination of direct chondrule accretion and giant impacts.

  16. Could 2003 VB12 (Sedna) Have Formed In Situ Within A Massive, Disk-Like Extension of the Kuiper Belt?

    NASA Astrophysics Data System (ADS)

    Stern, S. A.

    2004-05-01

    The discovery of the large (H=1.7) distant object, 2003 VB12, aka Sedna (Brown, Trujillo, and Rabinowitz 2004), is exciting on several grounds, not the least of which are the implications of its large size (D 2000 km) and distant, excited orbit (q 76 AU, a 532 AU, i 12 deg, e 0.86). Sedna's highly eccentric orbit clearly suggests it has been severely dynamically disturbed since its accretion, which must have occurred with e 0 and i 0. Early commentary on Sedna's origin (e.g., Brown et al., 2004; Morbidelli & Levison 2004) has centered on a formation location at <50 AU, with transport to the present orbit having resulted from a strong scattering event by a massive planet or a nearby star. Here I examine the viability of an alternate, in situ accretion (e.g., near 76 or 500 AU, Sedna's q and a) scenario, which would have been followed by dynamical evolution to the present orbit. Consider first a ``primordial formation" scenario taking 100-300 Myr, consistent with current accretion model results in the Kuiper Belt (e.g., Stern & Colwell 1997; Kenyon 2002). Doing so, we estimate that as little as 10 Earth masses of solids could have been required in a disk stretching from 70 to 100 AU region to produce Sedna-scale objects. If however Sedna formed in a very wide disk extending from 70 to 500 AU, then a significantly less plausible outer disk mass of 80-240 Earth masses in solids is implied. The implications of these results, which would require a more extended and massive Kuiper Disk, reminiscent of some broad extrasolar disks 100s of AU in extent, will be discussed.

  17. Dynamical implantation of objects in the Kuiper Belt

    SciTech Connect

    Brasil, P. I. O.

    2014-09-01

    Several models have been suggested in the past to describe the dynamical formation of hot Kuiper Belt objects (hereafter Hot Classicals or HCs for short). Here, we discuss a dynamical mechanism that allows orbits to evolve from the primordial planetesimal disk at ≲ 35 AU to reach the orbital region now occupied by HCs. We performed three different sets of numerical simulations to illustrate this mechanism. Two of these simulations were based on modern theories for the early evolution of the solar system (the Nice and jumping-Jupiter models). The third simulation was performed with the purpose of increasing the resolution at 41-46 AU. The common aspect of these simulations is that Neptune scatters planetesimals from ≲ 35 AU to >40 AU and then undergoes a long phase of slow residual migration. Our results show that to reach an HC orbit, a scattered planetesimal needs to be captured in a mean motion resonance (MMR) with Neptune where the perihelion distance rises due to the Kozai resonance (which occurs in MMRs even for moderate inclinations). Finally, while Neptune is still migrating, the planetesimal is released from the MMR on a stable HC orbit. We show that the orbital distribution of HCs expected from this process provides a reasonable match to observations. The capture efficiency and the mass deposited into the HC region appears to be sensitive to the maximum eccentricity reached by Neptune during the planetary instability phase. Additional work will be needed to resolve this dependency in detail.

  18. Dynamics of the Most Distant Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Volk, Kathryn; Malhotra, Renu; Wang, Xianyu

    2016-05-01

    We investigate the evolution of the most distant known Kuiper belt objects (KBOs) under the secular and resonant effects of the known planets in the Solar System as well as under the influence of a massive, unseen distant planet. The orbits of these distant KBOs evolve on a wide range of timescales (from millions to billions of years); most important are the changes in the objects’ perihelion distances which can dramatically change the relative domination of secular or resonant effects on their orbital evolution. Motivated by the period ratios of the distant KBOs, which are near simple integer ratios, we examine the properties of mean motion resonances with a hypothetical, unseen planet; we discuss how the uncertainties in the observed objects’ orbits compare to the widths of these hypothesized resonances. We also examine the timescales for secular orbital evolution and the timescales for scattering through close encounters in the models with and without the hypothetical planet to assess the case for such a planet.

  19. COLLISIONAL GROOMING MODELS OF THE KUIPER BELT DUST CLOUD

    SciTech Connect

    Kuchner, Marc J.; Stark, Christopher C. E-mail: starkc@umd.ed

    2010-10-15

    We modeled the three-dimensional structure of the Kuiper Belt (KB) dust cloud at four different dust production rates, incorporating both planet-dust interactions and grain-grain collisions using the collisional grooming algorithm. Simulated images of a model with a face-on optical depth of {approx}10{sup -4} primarily show an azimuthally symmetric ring at 40-47 AU in submillimeter and infrared wavelengths; this ring is associated with the cold classical KB. For models with lower optical depths (10{sup -6} and 10{sup -7}), synthetic infrared images show that the ring widens and a gap opens in the ring at the location of Neptune; this feature is caused by trapping of dust grains in Neptune's mean motion resonances. At low optical depths, a secondary ring also appears associated with the hole cleared in the center of the disk by Saturn. Our simulations, which incorporate 25 different grain sizes, illustrate that grain-grain collisions are important in sculpting today's KB dust, and probably other aspects of the solar system dust complex; collisions erase all signs of azimuthal asymmetry from the submillimeter image of the disk at every dust level we considered. The model images switch from being dominated by resonantly trapped small grains ('transport dominated') to being dominated by the birth ring ('collision dominated') when the optical depth reaches a critical value of {tau} {approx} v/c, where v is the local Keplerian speed.

  20. A Ninth Planet Would Produce a Distinctly Different Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Lawler, Samantha; Shankman, Cory; Kaib, Nathan A.; Bannister, Michele T.; Gladman, Brett; Kavelaars, J. J.

    2016-10-01

    The orbital element distribution of trans-Neptunian objects (TNOs) with large pericenters has been suggested to be influenced by the presence of an undetected, large planet at 200 or more AU from the Sun. We perform 4 Gyr N-body simulations with the currently known Solar System planetary architecture, plus a 10 Earth mass planet with similar orbital parameters to those suggested by Batygin and Brown (2016) or Trujillo and Sheppard (2014), and a hundred thousand test particles in an initial planetesimal disk. We find that including a distant superearth-mass ninth planet produces a substantially different orbital distribution for the scattering and detached TNOs, raising the pericenters and inclinations of moderate semimajor axis (50 < a < 500 AU) objects. We test whether this signature is detectable via a simulator with the observational characteristics of four precisely characterized TNO surveys. We find that the qualitatively very distinct Solar System models that include a ninth planet are essentially observationally indistinguishable from an outer Solar System produced solely by the four giant planets. We also find that the mass of the Kuiper Belt's current scattering and detached populations is required be 3-10 times larger in the presence of an additional planet. Wide-field, deep surveys targeting inclined high-pericenter objects will be required to distinguish between these different scenarios.

  1. Collisional Grooming Models of the Kuiper Belt Dust Cloud

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc J.; Stark, Christopher C.

    2010-01-01

    We modeled the three-dimensional structure of the Kuiper Belt (KB) dust cloud at four different dust production rates, incorporating both planet-dust interactions and grain-grain collisions using the collisional grooming algorithm. Simulated images of a model with a face-on optical depth of approximately 10 (exp -4) primarily show an azimuthally- symmetric ring at 40-47 AU in submillimeter and infrared wavelengths; this ring is associated with the cold classical KB. For models with lower optical depths (10 (exp -6) and 10 (exp-7)), synthetic infrared images show that the ring widens and a gap opens in the ring at the location of Neptune; this feature is caused by trapping of dust grains in Neptune's mean motion resonances. At low optical depths, a secondary ring also appears associated with the hole cleared in the center of the disk by Saturn. Our simulations, which incorporate 25 different grain sizes, illustrate that grain-grain collisions are important in sculpting today's KB dust, and probably other aspects of the solar system dust complex; collisions erase all signs of azimuthal asymmetry from the submillimeter image of the disk at every dust level we considered. The model images switch from being dominated by resonantly trapped small grains ("transport dominated") to being dominated by the birth ring ("collision dominated") when the optical depth reaches a critical value of r approximately v/c, where v is the local Keplerian speed.

  2. VOLATILE LOSS AND CLASSIFICATION OF KUIPER BELT OBJECTS

    SciTech Connect

    Johnson, R. E.; Schmidt, C.; Oza, A.; Young, L. A.; Volkov, A. N.

    2015-08-10

    Observations indicate that some of the largest Kuiper Belt Objects (KBOs) have retained volatiles in the gas phase (e.g., Pluto), while others have surface volatiles that might support a seasonal atmosphere (e.g., Eris). Since the presence of an atmosphere can affect their reflectance spectra and thermal balance, Schaller and Brown examined the role of volatile escape driven by solar heating of the surface. Guided by recent simulations, we estimate the loss of primordial N{sub 2} for several large KBOs, accounting for escape driven by UV/EUV heating of the upper atmosphere as well as by solar heating of the surface. For the latter we present new simulations and for the former we scale recent detailed simulations of escape from Pluto using the energy limited escape model validated recently by molecular kinetic simulations. Unlike what has been assumed to date, we show that unless the N{sub 2} atmosphere is thin (<∼10{sup 18} N{sub 2} cm{sup −2}) and/or the radius small (<∼200–300 km), escape is primarily driven by the UV/EUV radiation absorbed in the upper atmosphere. This affects the discussion of the relationship between atmospheric loss and the observed surface properties for a number of the KBOs examined. Our long-term goal is to connect detailed atmospheric loss simulations with a model for volatile transport for individual KBOs.

  3. The Bimodal Color Distribution of Small Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Wong, Ian; Brown, Michael E.

    2017-04-01

    We conducted a two-night photometric survey of small Kuiper Belt objects (KBOs) near opposition using the wide-field Hyper Suprime-Cam instrument on the 8.2 m Subaru Telescope. The survey covered about 90 deg2 of sky, with each field imaged in the g and i bands. We detected 356 KBOs, ranging in absolute magnitude from 6.5 to 10.4. Filtering for high-inclination objects within the hot KBO population, we show that the g ‑ i color distribution is strongly bimodal, indicative of two color classes—the red and very red subpopulations. After categorizing objects into the two subpopulations by color, we present the first dedicated analysis of the magnitude distributions of the individual color subpopulations and demonstrate that the two distributions are roughly identical in shape throughout the entire size range covered by our survey. Comparing the color distribution of small hot KBOs with that of Centaurs, we find that they have similar bimodal shapes, thereby providing strong confirmation of previous explanations for the attested bimodality of Centaurs. We also show that the magnitude distributions of the two KBO color subpopulations and the two color subpopulations observed in the Jupiter Trojans are statistically indistinguishable. Finally, we discuss a hypothesis describing the origin of the KBO color bimodality based on our survey results. Based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

  4. Atmospheres on Volatile-Bearing Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Young, Leslie; McKinnon, W. B.

    2013-10-01

    Seven large bodies in the outer solar system have volatiles ices detected or inferred on their surfaces (Pluto, Triton, Eris, Makemake, 2007 OR10, Quaoar, and Sedna; Brown et al. 2011, ApJ 738, L26), which may lead to atmospheres over some or most of their orbits (Stern & Trafton 2008, Sol. Sys. Beyond Neptune, 365-380). We have investigated the role of internal heat (e.g., McKinnon et al. 1997, Pluto and Charon, 295-343) and thermal inertia on the seasonally varying surface temperatures and atmospheres. We quantify when atmospheres are global (Pluto-like, with similar pressures over the surface), local but collisional (Io-like, with large pressure gradients), or non-collisional. We conclude that four bodies (Pluto, Triton, Eris and Quaoar) should be global over some or all of their orbits, and that 2007 OR10 should be global near perihelion only for low thermal inertia. Five bodies (Pluto, Triton, Eris, Makemake and Quaoar) should be global or local-collisional over their entire orbits. 2007 OR10 reaches non-collisional pressures at aphelion for low thermal inertia. Sedna is non-collisional for most of its orbit, but may be collisional near perihelion for low thermal inertia. Long-lived radiogenic heat can be important for the atmospheres of larger and/or more distant Kuiper belt objects.

  5. The formation of Kuiper-belt binaries through exchange reactions.

    PubMed

    Funato, Yoko; Makino, Junichiro; Hut, Piet; Kokubo, Eiichiro; Kinoshita, Daisuke

    2004-02-05

    Recent observations have revealed that an unexpectedly high fraction--a few per cent--of the trans-Neptunian objects (TNOs) that inhabit the Kuiper belt are binaries. The components have roughly equal masses, with very eccentric orbits that are wider than a hundred times the radius of the primary. Standard theories of binary asteroid formation tend to produce close binaries with circular orbits, so two models have been proposed to explain the unique characteristics of the TNOs. Both models, however, require extreme assumptions regarding the size distribution of the TNOs. Here we report a mechanism that is capable of producing binary TNOs with the observed properties during the early stages of their formation and growth. The only required assumption is that the TNOs were initially formed through gravitational instabilities in the protoplanetary dust disk. The basis of the mechanism is an exchange reaction in which a binary whose primary component is much more massive than the secondary interacts with a third body, whose mass is comparable to that of the primary. The low-mass secondary component is ejected and replaced by the third body in a wide but eccentric orbit.

  6. Volatile Loss and Classification of Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Johnson, R. E.; Oza, A.; Young, L. A.; Volkov, A. N.; Schmidt, C.

    2015-08-01

    Observations indicate that some of the largest Kuiper Belt Objects (KBOs) have retained volatiles in the gas phase (e.g., Pluto), while others have surface volatiles that might support a seasonal atmosphere (e.g., Eris). Since the presence of an atmosphere can affect their reflectance spectra and thermal balance, Schaller & Brown examined the role of volatile escape driven by solar heating of the surface. Guided by recent simulations, we estimate the loss of primordial N2 for several large KBOs, accounting for escape driven by UV/EUV heating of the upper atmosphere as well as by solar heating of the surface. For the latter we present new simulations and for the former we scale recent detailed simulations of escape from Pluto using the energy limited escape model validated recently by molecular kinetic simulations. Unlike what has been assumed to date, we show that unless the N2 atmosphere is thin (<˜1018 N2 cm-2) and/or the radius small (<˜200-300 km), escape is primarily driven by the UV/EUV radiation absorbed in the upper atmosphere. This affects the discussion of the relationship between atmospheric loss and the observed surface properties for a number of the KBOs examined. Our long-term goal is to connect detailed atmospheric loss simulations with a model for volatile transport for individual KBOs.

  7. Collisional Grooming Models of the Kuiper Belt Dust Cloud

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc J.; Stark, Christopher C.

    2010-01-01

    We modeled the three-dimensional structure of the Kuiper Belt (KB) dust cloud at four different dust production rates, incorporating both planet-dust interactions and grain-grain collisions using the collisional grooming algorithm. Simulated images of a model with a face-on optical depth of approximately 10 (exp -4) primarily show an azimuthally- symmetric ring at 40-47 AU in submillimeter and infrared wavelengths; this ring is associated with the cold classical KB. For models with lower optical depths (10 (exp -6) and 10 (exp-7)), synthetic infrared images show that the ring widens and a gap opens in the ring at the location of Neptune; this feature is caused by trapping of dust grains in Neptune's mean motion resonances. At low optical depths, a secondary ring also appears associated with the hole cleared in the center of the disk by Saturn. Our simulations, which incorporate 25 different grain sizes, illustrate that grain-grain collisions are important in sculpting today's KB dust, and probably other aspects of the solar system dust complex; collisions erase all signs of azimuthal asymmetry from the submillimeter image of the disk at every dust level we considered. The model images switch from being dominated by resonantly trapped small grains ("transport dominated") to being dominated by the birth ring ("collision dominated") when the optical depth reaches a critical value of r approximately v/c, where v is the local Keplerian speed.

  8. Searching for Widely Separated Asymmetric Binaries in the Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Barker, Elizabeth A.; Noll, K. S.

    2007-10-01

    We have searched for widely separated transneptunian binaries in dithered observations using the HST Advanced Camera for Surveys High Resolution Channel. In order to automate the combining of images, we have have developed a pipeline of several scripts, utilizing the power of Python to drive the MultiDrizzle PyRAF task within STSDAS and the accessiblity of IDL to interact with the graphical display. We rely on MultiDrizzle to geometrically correct, sub-pixel shift, and drizzle multiple images of target objects. This process removes cosmic rays; with four images we find no artifacts from multiple cosmic ray hits in the drizzled images. We have examined the drizzled images for possible faint companions that would be missed in cosmic-ray impacted images. However, there are numerous image artifacts that require additional investigation to rule out possible close companions. Searching for distant, faint secondaries allows us to better understand transneptunian populations, since the fraction of binaries is a fundamental and characteristic quality. Asymmetric systems, that is, systems with a large brightness difference between primary and secondary, are common among the brightest (largest) Kuiper Belt objects (Brown et al. 2006, Brown and Suer 2007), and may be the result of collisions. Small satellites appear to be absent among the fainter (smaller) objects. A detailed search, like the one we are performing, can further constrain the roles of collisions and capture in forming binaries among the small body populations of the solar system.

  9. Two Color Populations of Kuiper Belt and Centaur Objects

    NASA Astrophysics Data System (ADS)

    Tegler, Stephen C.; Romanishin, William; Consolmagno, Guy

    2016-10-01

    We present new optical colors for 64 Kuiper belt objects (KBOs) and Centaur objects measured with the 1.8-meter Vatican Advanced Technology Telescope (VATT) and the 4.3-meter Discovery Channel Telescope (DCT). By combining these new colors with our previously published colors, we increase the sample size of our survey to 154 objects. Our survey is unique in that the uncertainties in our color measurements are less than half the uncertainties in the color measurements reported by other researchers in the literature. Small uncertainties are essential for discerning between a unimodal and a bimodal distribution of colors for these objects as well as detecting correlations between colors and orbital elements. From our survey, it appears red Centaurs have a broader color distribution than grey Centaurs. We find red Centaurs have a smaller orbital inclination angle distribution than grey Centaurs at the 99.3% confidence level. Furthermore, we find that our entire sample of KBOs and Centaurs exhibits bimodal colors at the 99.4% confidence level. KBOs and Centaurs with HV > 7.0 have bimodal colors at the 99.96% confidence level and KBOs with HV < 6.0 have bimodal colors at the 96.3% confidence level.We are grateful to the NASA Solar System Observations Program for support, NAU for joining the Discovery Channel Telescope Partnership, and the Vatican Observatory for the consistent allocation of telescope time over the last 12 years of this project.

  10. 1999 KUIPER PRIZE LECTURE. Cometary Origin of the Biosphere

    NASA Astrophysics Data System (ADS)

    Delsemme, Armand H.

    2000-08-01

    Most of the biosphere was brought on the primitive Earth by an intense bombardment of comets. This included the atmosphere, the seawater and those volatile carbon compounds needed for the emergence of life. Comets were thrown into the inner Solar System by the strong perturbation induced by the growth of the giant planets' cores. The bulk of the Earth's bombardment came from those comets that accreted in Jupiter's zone, where the original deuterium enrichment had been diminished by steam coming from the hot, inner parts of the Solar System. This steam had condensed into icy chunks before their accretion into larger cometary nuclei. In contrast, comets that accreted in the zones of the outer giant planets kept their interstellar isotopic enrichments. Those comets contributed to the Earth's bombardment for a small amount only; they were mostly ejected into the Oort cloud and are the major source of the long-period comets observed today. The short-period comets, which come from the Kuiper Belt, should also have the same interstellar enrichment. The deuterium enrichment of seawater, accurately predicted by the previous scenario, has become one of the best telltales for the cometary origin of our biosphere. This cometary origin may have far-reaching cosmological consequences, in particular for the origin of life in other planetary systems.

  11. Exo-Kuiper Belts around Sun-like Stars

    NASA Astrophysics Data System (ADS)

    Koerner, David

    We propose SOFIA/HAWC+ observations of debris disks around two nearby G-type stars. Our goals are to characterize the spectral distribution and temperature of circumstellar dust with photometric observations at wavelengths of 53, 89, 154, and 214 microns (HAWC+ bands A, C, D, and E) and to resolve the dust morphology in the smaller beams of the two shortest wavelengths. Spitzer/MIPS observations of each target revealed strong excess infrared emission (> 200 mJy) at 70 microns but none at 24 microns. These properties strongly indicate that each star is surrounded by a cold outer disk. Neither target was observed at longer wavelengths or with higher resolution by Herschel Space Observatory, so details about ring dimensions and thermal properties are lacking. The cold temperature of the dust (T < 70 K) and proximity of the targets (d < 25 pc) suggest they each possess a large outer ring that could be resolved by SOFIA at 53 and 89 microns. If so, the rings may show evidence of the gravitational influence of an outermost giant planet by analogy with the Kuiper Belt in our solar system and offset rings seen around a small number of other stars with Hubble Space Telescope. HAWC+ is the only instrument currently available to image thermal emission from the rings at wavelengths of peak dust emission and with angular resolution needed to identify spatial structure.

  12. 75 FR 80731 - Request for Exclusion of 120 Volt, 100 Watt R20 Short Incandescent Reflector Lamps

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-23

    ..., which is marketed for use in hot tub spas. Public comment is requested on whether DOE should grant the... watt R20 short, which is marketed exclusively for use in hot tub spas sold into specific jurisdictions that provide pools and ] spas with 120 volt electricity--be excluded from the coverage of energy...

  13. 77 FR 76959 - Energy Conservation Program: Request for Exclusion of 100 Watt R20 Short Incandescent Reflector...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-31

    ... distinctive features, pricing, and application-specific labeling and marketing of R20 short lamps provide a... square foot of water surface area, or equivalent level of illumination, to account for commercial... assure water quality. Therefore, CA Utilities concluded that low-wattage replacement lamps can be used...

  14. 72 FR 7917 - PS-ACE100-2005-50001, Final Policy Statement on Applying Advisory Circular 20-152, “RTCA, Inc...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2007-02-21

    ... TRANSPORTATION Federal Aviation Administration PS-ACE100-2005-50001, Final Policy Statement on Applying Advisory Circular 20-152, ``RTCA, Inc., Document RTCA/DO-254, Design Assurance Guidance for Airborne Electronic... Administration, DOT. ACTION: Notice of issuance of policy. SUMMARY: This notice announces the issuance of...

  15. Remaining Sites Verification Package for the 100-B-20, 1716-B Maintenance Garage Underground Tank, Waste Site Reclassification Form 2006-019

    SciTech Connect

    L. M. Dittmer

    2006-09-27

    The 100-B-20 waste site, located in the 100-BC-1 Operable Unit of the Hanford Site, consisted of an underground oil tank that once serviced the 1716-B Maintenance Garage. The selected action for the 100-B-20 waste site involved removal of the oil tanks and their contents and demonstrating through confirmatory sampling that all cleanup goals have been met. In accordance with this evaluation, a reclassification status of interim closed out has been determined. The results demonstrate that the site will support future unrestricted land uses that can be represented by a rural-residential scenario. These results also show that residual concentrations support unrestricted future use of shallow zone soil and that contaminant levels remaining in the soil are protective of groundwater and the Columbia River.

  16. THE SURFACE COMPOSITION OF LARGE KUIPER BELT OBJECT 2007 OR10

    SciTech Connect

    Brown, M. E.; Fraser, W. C.; Burgasser, A. J.

    2011-09-10

    We present photometry and spectra of the large Kuiper belt object 2007 OR10. The data show significant near-infrared absorption features due to water ice. While most objects in the Kuiper belt with water ice absorption this prominent have the optically neutral colors of water ice, 2007 OR10 is among the reddest Kuiper belt objects known. One other large Kuiper belt object-Quaoar-has similar red coloring and water ice absorption, and it is hypothesized that the red coloration of this object is due to irradiation of the small amounts of methane able to be retained on Quaoar. 2007 OR10, though warmer than Quaoar, is in a similar volatile retention regime because it is sufficiently larger that its stronger gravity can still retain methane. We propose, therefore, that the red coloration on 2007 OR10 is also caused by the retention of small amounts of methane. Positive detection of methane on 2007 OR10 will require spectra with higher signal to noise. Models for volatile retention on Kuiper belt objects appear to continue to do an excellent job reproducing all of the available observations.

  17. A single sub-kilometre Kuiper belt object from a stellar occultation in archival data.

    PubMed

    Schlichting, H E; Ofek, E O; Wenz, M; Sari, R; Gal-Yam, A; Livio, M; Nelan, E; Zucker, S

    2009-12-17

    The Kuiper belt is a remnant of the primordial Solar System. Measurements of its size distribution constrain its accretion and collisional history, and the importance of material strength of Kuiper belt objects. Small, sub-kilometre-sized, Kuiper belt objects elude direct detection, but the signature of their occultations of background stars should be detectable. Observations at both optical and X-ray wavelengths claim to have detected such occultations, but their implied abundances are inconsistent with each other and far exceed theoretical expectations. Here we report an analysis of archival data that reveals an occultation by a body with an approximately 500-metre radius at a distance of 45 astronomical units. The probability of this event arising from random statistical fluctuations within our data set is about two per cent. Our survey yields a surface density of Kuiper belt objects with radii exceeding 250 metres of 2.1(-1.7)(+4.8) x 10(7) deg(-2), ruling out inferred surface densities from previous claimed detections by more than 5sigma. The detection of only one event reveals a deficit of sub-kilometre-sized Kuiper belt objects compared to a population extrapolated from objects with radii exceeding 50 kilometres. This implies that sub-kilometre-sized objects are undergoing collisional erosion, just like debris disks observed around other stars.

  18. Purification of bacterial genomic DNA in less than 20 min using chelex-100 microwave: examples from strains of lactic acid bacteria isolated from soil samples.

    PubMed

    Reyes-Escogido, Lourdes; Balam-Chi, Mario; Rodríguez-Buenfil, Ingrid; Valdés, Jesús; Kameyama, Luis; Martínez-Pérez, Francisco

    2010-11-01

    We established a Chelex 100-Microwave method for the purification of bacterial genomic DNA (gDNA) in less than 20 min with high yield and good quality, useful for multiple purposes. It combines Chelex 100, proteinase K, RNase A and heating in a microwave oven. The resulting gDNA was used directly to identify bacterial species of the Order Lactobacillales by means of PCR amplification of their 16S rDNA gene, isolated from sediments on the Yucatan Peninsula, Mexico. This method produced gDNA free of phenolic and protein residual contaminants from 100 of these isolated bacteria. 16S rDNA amplification and sequencing showed Pediococcus acidilactici to prevail in inland lagoons, and Pediococcus pentosaceus, Lactobacillus plantarum, Lactobacillus sp., and Lactobacillus fermentum to be most abundant in the soils of livestock farms. The combination of Chelex 100, enzymes and microwave heating used in the Chelex 100-Microwave method produced large amounts of highly pure gDNA from Gram-positive and Gram-negative bacteria, in less than 20 min.

  19. Kuiper belt objects: radionuclide impact on internal structure dynamics

    NASA Astrophysics Data System (ADS)

    Shchuko, Oleg; Shchuko, Svetlana; Kartashov, Daniil; Orosei, Roberto

    2010-05-01

    The process of Kuiper Belt objects (KBO) matter formation and its internal structure evolution is investigate as dependent on the factors affecting the intensity of radiogenic heating sources. A solid dust aluminosilicate substance of fringe protosolar cloud regions and amorphous ice H2O have been supposed to be the building material of the KBO matter formation. Radionuclides 26Al, 40K, 232Th, 235U and 238U embedded in solid dust matter particles have been main sources of radiogenic heat for the KBO life time. A spherically symmetric celestial body was being created as a result of accretion. The body's internal structure was determined by the composition and the properties of the accretion material and the evolution of the structure - by internal thermal processes. The dependence of the forming body interior composition and structure on the accretion process rate, on the specific gravities of dust matter and amorphous ice as well as on the possible variations of these parameters along the forming body orbit, has been studied. Parameter variation domains have been determined at which the formed celestial body has its present-day sizes and average density. The impact of the heat-and-power potentials of radiogenic heat sources on H2O phase transition dynamics in the celestial body matter has been investigated. The parameter variation domains of these potentials have been found at which there can be formed areas partly or fully filled with H2O of different phase states. In addition, the dynamic boundaries of areas have been determined where the ice component is presented by amorphous ice or cubic and hexagonal crystal ice. The parameter domains of celestial body accretion and radiogenic heat processes have been determined where the body evolution may have a catastrophic scenario up to its complete destruction.

  20. Interpreting the densities of the Kuiper belt's dwarf planets

    NASA Astrophysics Data System (ADS)

    Barr, Amy C.; Schwamb, Megan E.

    2016-08-01

    Kuiper belt objects (KBOs) with absolute magnitude less than 3 (radius ≳500 km), the dwarf planets, have a range of different ice/rock ratios, and are more rock-rich than their smaller counterparts. Many of these objects have moons, which suggests that collisions may have played a role in modifying their compositions. We show that the dwarf planets fall into two categories when analysed by their mean densities and satellite-to-primary size ratio. Systems with large moons, such as Pluto/Charon and Orcus/Vanth, can form in low-velocity grazing collisions in which both bodies retain their compositions. We propose that these systems retain a primordial composition, with a density of about 1.8 g cm-3. Triton, thought to be a captured KBO, could have lost enough ice during its early orbital evolution to explain its rock-enrichment relative to the primordial material. Systems with small moons, Eris, Haumea, and Quaoar, formed from a different type of collision in which icy material, perhaps a few tens of percent of the total colliding mass, is lost. The fragments would not remain in physical or dynamical proximity to the parent body. The ice loss process has not yet been demonstrated numerically, which could be due to the paucity of KBO origin simulations, or missing physical processes in the impact models. If our hypothesis is correct, we predict that large KBOs with small moons should be denser than the primordial material, and that the mean density of Orcus should be close to the primordial value.

  1. IceCube: A Cubic Kilometer Radiation Detector

    SciTech Connect

    IceCube Collaboration; Klein, Spencer R; Klein, S.R.

    2008-06-01

    IceCube is a 1 km{sup 3} neutrino detector now being built at the Amudsen-Scott South Pole Station. It consists of 4800 Digital Optical Modules (DOMs) which detect Cherenkov radiation from the charged particles produced in neutrino interactions. IceCube will observe astrophysical neutrinos with energies above about 100 GeV. IceCube will be able to separate {nu}{sub {mu}}, {nu}{sub t}, and {nu}{sub {tau}} interactions because of their different topologies. IceCube construction is currently 50% complete.

  2. KEY COMPARISON: Results of the key comparison CCM.FF-K4 for volume of liquids at 20 L and 100 mL

    NASA Astrophysics Data System (ADS)

    Arias, Roberto; Maldonado, Manuel; Wright, John; Jacques, Claude; Lachance, Christian; Lau, Peter; Többen, Helmut; Cignolo, Giorgio; Lorefice, Salvatore; Man, John; Aibe, Valter Y.

    2006-01-01

    A key comparison was performed in order to compare national measurement systems to determine volume of liquids, particularly at fixed volumes of 20 L and 100 mL. The participants were CENAM (Mexico), NIST (United States of America), NRC/MC (Canada), SP (Sweden), PTB (Germany), INRIM (former IMGC, Italy), NMIA (Australia) and INMETRO (Brazil). CENAM acted as pilot laboratory. The measurements were carried out from December 2003 to March 2005. The chosen values of volume (20 L and 100 mL) are both representatives of the Calibration and Measurement Capabilities (CMCs) declared by most of the participating national metrology institutes. The transfer standards (TSs) were three stainless steel pipettes for volume at 20 L and six commercially available glass pycnometers for volume at 100 mL. Prior to the beginning of the key comparison, the 20 L TSs were tested by CENAM, SP and NMIA The results of the test phase showed excellent values for both repeatability and reproducibility. During the CCM.FF-K4, the results of most of the laboratories showed good agreement with the reference values. The best estimation of the measurands, as reported by the participants showed a general agreement better than ±0.0025% for volume of liquids at 100 mL and 20 L. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  3. Kilometer-range nonlinear propagation of femtosecond laser pulses.

    PubMed

    Rodriguez, Miguel; Bourayou, Riad; Méjean, Guillaume; Kasparian, Jérôme; Yu, Jin; Salmon, Estelle; Scholz, Alexander; Stecklum, Bringfried; Eislöffel, Jochen; Laux, Uwe; Hatzes, Artie P; Sauerbrey, Roland; Wöste, Ludger; Wolf, Jean-Pierre

    2004-03-01

    Ultrashort, high-power laser pulses propagating vertically in the atmosphere have been observed over more than 20 km using an imaging 2-m astronomical telescope. This direct observation in several wavelength bands shows indications for filament formation at distances as far as 2 km in the atmosphere. Moreover, the beam divergence at 5 km altitude is smaller than expected, bearing evidence for whole-beam parallelization about the nonlinear focus. We discuss implications for white-light Lidar applications.

  4. Optimization of transistor design including large signal device/circuit interactions at extremely high frequencies (20-100+GHz)

    NASA Technical Reports Server (NTRS)

    Levy, Ralph; Grubin, H. L.

    1991-01-01

    Transistor design for extremely high frequency applications requires consideration of the interaction between the device and the circuit to which it is connected. Traditional analytical transistor models are to approximate at some of these frequencies and may not account for variations of dopants and semiconductor materials (especially some of the newer materials) within the device. Physically based models of device performance are required. These are based on coupled systems of partial differential equations and typically require 20 minutes of Cray computer time for a single AC operating point. A technique is presented to extract parameters from a few partial differential equation solutions for the device to create a nonlinear equivalent circuit model which runs in approximately 1 second of personal computer time. This nonlinear equivalent circuit model accurately replicates the contact current properties of the device as computed by the partial differential solver on which it is based. Using the nonlinear equivalent circuit model of the device, optimization of systems design can be performed based on device/circuit interactions.

  5. Optical properties of polyvinyl alcohol doped (Se80Te20)100-xAgx (0 ≤ x ≤ 4) composites

    NASA Astrophysics Data System (ADS)

    Singh, D.; Kumar, S.; Thangaraj, R.

    2014-02-01

    Polyvinyl alcohol (PVA) doped (Se80Te20)100-xAgx (0 ≤ x ≤ 4) thin films were prepared by the spin-coating technique on a quartz substrate. The optical parameters of PVA-doped (Se80Te20)100-xAgx (0 ≤ x ≤ 4) composites at the same chalcogen concentration (S0 = 0.1 mg ml-1) and PVA/(Se80Te20)96Ag4 composites at three different chalcogen concentrations viz. S1 = 0.3 mg ml-1, S2 = 0.6 mg ml-1 and S3 = 1 mg ml-1 have been studied. The semi-crystalline nature of the as-deposited thin filmsisdetermined by X-ray diffraction. The transmission and reflection spectra of PVA-doped Se-Te-Ag thin films were obtained in a 350-650 nm spectral region. The optical-band gap has been calculated from the transmission and reflection data. The refractive index has been calculated by the measured reflection data. It has been found that the optical-band gap increases, but the refractive index, extinction coefficient, and the real and imaginary parts of the dielectric constant decrease, with increase in Agcontent in PVA-doped (Se80Te20)100-xAgx (0 ≤ x ≤ 4) thin films. Such type of behavior is explained on the basis of decrease in density of the defect states. However, the optical-band gap has been found to be decreased and all other optical parameters show increase in their values with increase in concentration of (Se80Te20)96Ag4 glass in PVA-doped composites. The results have been explained on the basis of cluster-size formation at the time of dissolution. This study shows that the optical properties of new composites are affected by the change in silver and chalcogen concentration.

  6. Effects of 10min vs. 20min passive rest after warm-up on 100m freestyle time-trial performance: A randomized crossover study.

    PubMed

    Neiva, Henrique P; Marques, Mário C; Barbosa, Tiago M; Izquierdo, Mikel; Viana, João L; Marinho, Daniel A

    2017-01-01

    The aim of this study was to compare the effect of 10min vs. 20min passive rest post warm-up on performance in a 100m freestyle time-trial. Randomized crossover. Eleven competitive male swimmers performed two experimental trials on different days, consisting of 100m freestyle time-trials following 10min or 20min passive rest after a standard 1200m warm-up. Performance (time-trial), biomechanical (stroke length, stroke frequency, stroke index, propelling efficiency), physiological (blood lactate concentrations, heart rate, core and tympanic temperature), and psychophysiological (perceived effort) variables were assessed during both trials. Time-trial performance was faster after 10min as opposed to 20min passive rest (58.41±1.99s vs. 59.06±1.86, p<0.01). This was supported by strong effect sizes (d=0.99) and the qualitative indication of "likely" positive effects. Heart rate before the time-trial was also higher after 10min passive rest (89±12bpm vs. 82±13bpm; p<0.01). Furthermore, net core temperature and oxygen uptake values before the time-trial were substantially lower after 20min passive rest. These data suggest that the 10min post warm-up passive rest enhances 100m freestyle performance when compared to a 20min period. An improvement that appears to be mediated by the combined effects of a shorter post warm-up period on core temperature, heart rate and oxygen uptake. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  7. The dust-to-ices ratio in comets and Kuiper belt objects

    NASA Astrophysics Data System (ADS)

    Fulle, M.; Della Corte, V.; Rotundi, A.; Green, S. F.; Accolla, M.; Colangeli, L.; Ferrari, M.; Ivanovski, S.; Sordini, R.; Zakharov, V.

    2017-07-01

    Comet 67P/Churyumov-Gerasimenko (67P hereinafter) is characterized by a dust transfer from the southern hemi-nucleus to the night-side northern dust deposits, which constrains the dust-to-ices mass ratio inside the nucleus to values a factor of 2 larger than that provided by the lost mass of gas and non-volatiles. This applies to all comets because the gas density in all night comae cannot prevent the dust fallback. Taking into account Grain Impact Analyser and Dust Accumulator (GIADA) data collected during the entire Rosetta mission, we update the average dust bulk density to ρ {}{}_D = 785_{-115}^{+520} kg m-3 that, coupled to the 67P nucleus bulk density, confirms an average dust-to-ices mass ratio δ = 7.5 inside 67P. The improved dust densities are consistent with a mixture of (20 ± 8) per cent of ices, (4 ± 1) per cent of Fe sulphides, (22 ± 2) per cent of silicates and (54 ± 5) per cent of hydrocarbons, on average volume abundances. These values correspond to solar chemical abundances, as suggested by the elemental C/Fe ratio observed in 67P. The ice content in 67P matches that inferred in Kuiper belt objects, (20 ± 12) per cent on average volume abundance and suggests a water content in all trans-Neptunian objects lower than in CI chondrites. The 67P icy pebbles and the dust collected by GIADA have a microporosity of (49 ± 5) and (59 ± 8) per cent, respectively.

  8. The Era After the ELT: Optical Interferometry With Kilometer Baselines

    NASA Astrophysics Data System (ADS)

    Bakker, Eric J.

    2007-12-01

    The 8-meter class telescopes seen first light in 1993-1998 (Keck, 1993, VLT 1998). The ELT will see first light in the 2013-2018 time frame. The follow-up of the ELT will see first light around 2023. That is 15 years from today. The sequence from 8-meter to 30 meter telescopes (started as a goal of 100m), will suggest a follow-up telescope with an aperture of 300 meter as initial goal. Cleary a 300 meter or more ambitiously a 1000-meter telescope can no longer be structural one piece that has to point to any point on the sky and track the objects. The more likely scenario is to follow the process applied in radio astronomy and move from single telescopes to interferometers. Optical interferometry is maturing very quickly with the de-commissioning of experimental instruments (COAST, GT2I, IOTA, and probably PTI and ISI in the near future) and the use of precision mechanics and automation. The remaining interferometers are grouped in three categories: large telescopes (VLTI and KECK-I), mid-size interferometers (MROI) and small interferometers (CHARA and NPOI). The Magdalena Ridge Observatory Interferometer (MROI) is scheduled for first light/fringe in 2009 and will provide unique observing capabilities to astronomers with limiting magnitudes in the same range as those currently achieved by Keck-I and VLTI. The Magdalena Ridge Observatory Interferometer (near Socorro, NM) invites interested engineers, scientists, and astronomers to participate in the construction and science program of MRO at all levels. Ranging from visitors instruments, support of large procurements in return for access, to individual contributions related to the science program, shared risk observations, etc. For more information, contact the Project Manager at the Magdalena Ridge Observatory Interferometer.

  9. Volatile Loss and Classification of Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Johnson, Robert E.; Oza, Apurva; Young, Leslie A.; Volkov, Alexey N.; Schmidt, Carl A.

    2014-11-01

    Some of the largest Kuiper Belt Objects (KBOs) appear to have retained volatiles which affect their spectra, thermal energy balance, and atmospheres. Schaller & Brown (2007) (SB) estimated atmospheric escape rates from KBOs using Jeans escape from the surface, which they suggested gives a lower limit to the net atmospheric loss, and Levi & Podolak (2009) (LP) used a hydrodynamic model driven by the surface temperature. Based on recent molecular kinetic simulations, the SB escape rates are not necessarily lower limits and can be hugely in error, while the LP rates are valid only for KBOs with very small Jeans parameters (Volkov et al., 2011a,b). In addition, unless the atmosphere is thin or the body very small, escape can be driven primarily by the UV/EUV radiation absorbed in the upper atmosphere. Here we estimate the N2 loss from several KBOs, guided by recent molecular kinetic simulations that include thermal energy balance at the surface and heating of the upper atmosphere by UV/EUV irradiance. For the latter effect, we extrapolate simulations of escape from Pluto (Erwin et al., 2013; Zhu et al. 2014) using an energy limited escape model, which we have recently validated via molecular kinetic simulations (Johnson et al., 2013). In this way, we improve on current estimates of atmospheric retention and use the results to interpret the spectral differences observed. The longer-term goal is to connect detailed atmospheric loss mechanisms with a model for volatile transport (e.g., Young, 2014) in order to better describe recent KBO observations.ReferencesJohnson, R.E., A.N. Volkov and J.T. Erwin, Astrophys J. Lett. 768:L4, 2013.Levi, A. and M. Podolak, Icarus 202,681-693, 2009.Schaller, E.L. and M. E. Brown Astrophys. J., 659: L61-L64, 2007Volkov, A.N., R.E. Johnson, O.J. Tucker, J.T. Erwin, Astrophys. J. Lett. 729: L24, 2011a.Volkov, A.N, O.J. Tucker, J.T. Erwin, R.E. Johnson, Phys. of Fluids 23, 066601, 2011b.Young, L.A. , Icarus 221, 80-88, 2014Zhu, X., Strobel, D

  10. The absolute magnitude distribution of Kuiper Belt objects

    SciTech Connect

    Fraser, Wesley C.; Brown, Michael E.; Morbidelli, Alessandro; Parker, Alex; Batygin, Konstantin

    2014-02-20

    Here we measure the absolute magnitude distributions (H-distribution) of the dynamically excited and quiescent (hot and cold) Kuiper Belt objects (KBOs), and test if they share the same H-distribution as the Jupiter Trojans. From a compilation of all useable ecliptic surveys, we find that the KBO H-distributions are well described by broken power laws. The cold population has a bright-end slope, α{sub 1}=1.5{sub −0.2}{sup +0.4}, and break magnitude, H{sub B}=6.9{sub −0.2}{sup +0.1} (r'-band). The hot population has a shallower bright-end slope of, α{sub 1}=0.87{sub −0.2}{sup +0.07}, and break magnitude H{sub B}=7.7{sub −0.5}{sup +1.0}. Both populations share similar faint-end slopes of α{sub 2} ∼ 0.2. We estimate the masses of the hot and cold populations are ∼0.01 and ∼3 × 10{sup –4} M {sub ⊕}. The broken power-law fit to the Trojan H-distribution has α{sub 1} = 1.0 ± 0.2, α{sub 2} = 0.36 ± 0.01, and H {sub B} = 8.3. The Kolmogorov-Smirnov test reveals that the probability that the Trojans and cold KBOs share the same parent H-distribution is less than 1 in 1000. When the bimodal albedo distribution of the hot objects is accounted for, there is no evidence that the H-distributions of the Trojans and hot KBOs differ. Our findings are in agreement with the predictions of the Nice model in terms of both mass and H-distribution of the hot and Trojan populations. Wide-field survey data suggest that the brightest few hot objects, with H{sub r{sup ′}}≲3, do not fall on the steep power-law slope of fainter hot objects. Under the standard hierarchical model of planetesimal formation, it is difficult to account for the similar break diameters of the hot and cold populations given the low mass of the cold belt.

  11. The New Horizons Mission to Pluto and the Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Weaver, Harold; Grundy, William; Stern, Alan; Young, Leslie; Bagenal, Fran; Binzel, Richard; Buratti, Bonnie; Cheng, A.; Cruikshan, Dale; Gladstone, Randy; Hinson, David; Horanyi, Mihaly; Jennings, Don; Linscott, Ivan; McComas, Dave; McKinnon, William; McNutt, R.; Moore, Jeffrey; Murchie, S.; Olkin, Cathy; Porco, Carolyn; Reitsema, Harold; Reuter, Dennis; Slater, Dave; Spencer, John; Strobel, Darrell; Summers, Michael; Tyler, Len

    New Horizons (NH) is a NASA mission that will provide the first in situ reconnaissance of Pluto and its moons Charon, Nix, and Hydra. The NH spacecraft was launched on 2006 January 19, received a gravity assist from Jupiter during closest approach on 2007 February 28 at a distance of ˜32 RJ, and is currently heading for a flyby encounter with the Pluto system. Among the many science results at Jupiter were a detection of planet-wide mesoscale waves, eruptions of atmospheric ammonia clouds, unprecedented views of Io's volcanic plumes and Jupiter's tenuous ring system, the first close-up view of the Little Red Spot (LRS), the discovery of polar lightning, and the first trip down the tail of the magnetosphere. In 2015, NH will conduct a seven-month investigation of the Pluto system culminating in a closest approach some 12,500 km from Pluto's surface on 2014 July 14. Planning is presently underway for the Pluto encounter with special emphasis on long-identified science goals of studying the terrain, geology, and composition of the surfaces of Pluto and Charon, examining the composition and structure of Pluto's atmosphere, searching for an atmosphere on Charon, and characterizing Pluto's ionosphere and solar wind interaction. Detailed investigations will also be performed of the smaller satellites Nix and Hydra. Additionally, NH will characterize energetic particles in Pluto's environment, refine the bulk properties of Pluto and Charon, and search for additional satellites and rings. If approved for an extended mission phase after the Pluto encounter, NH will continue on to a flyby encounter with one or more Kuiper belt objects (KBOs). The NH spacecraft and its instruments have continued to perform nominally, as verified by annual checkout (ACO) activities conducted each year. Serendipitously, NH the spacecraft will be occulted by Earth's Moon four different times during 2011-2012, allowing for an in-flight test of the radio uplink occultation technique that will be

  12. KEY COMPARISON: Final report on regional key comparison SIM.M.FF-K4: Volume of liquids at 20 L and 100 mL

    NASA Astrophysics Data System (ADS)

    Arias, Roberto; Maldonado, Manuel; Wright, John; Wallace, Tanisha; Rodríguez, Sandra; Pinzón, Orlando; Morales, Abed; Vega, Maria; Santo, Claudia; Kornblit, Fernando; Malta, Dalni

    2010-01-01

    At its meeting in October 2006 in Querétaro, Mexico, the Interamerican Metrology System (SIM) Technical Committee for Fluid Flow (TCFF) approved a Regional Key Comparison for Volume of Liquids at 20 L and 100 mL, to be piloted by the national metrology institute of Mexico (CENAM). The objective of this comparison was to demonstrate the degree of equivalence of the volume measurement standards held at national measurement institutes (NMIs) and to provide supporting evidence for the Calibration and Measurement Capabilities (CMCs) claimed by the participating laboratories in the Americas. During the comparison, one of the pycnometers suffered irreversible damage, and degrees of equivalence for volume at 100 mL were calculated using the results obtained with one single pycnometer (TS 03.04.04). Conclusions are as follows: The transfer standards for SIM.M.FF-K4 exhibited global good performance all the way along, both in terms of stability and repeatability. Degrees of equivalence have been produced for volumes at 20 L and at 100 mL. The best estimation of the measurands, as reported by the participants, shows a general agreement better than +/-0.0070% for volume of liquids at 100 mL and 20 L. It is advisable to review the uncertainty analysis of some participants. New CMC entries for some NMIs should take into account the information presented in this Report. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  13. Hydrated Silicates on Edgeworth-Kuiper Objects - Probable Ways of Formation

    NASA Astrophysics Data System (ADS)

    Busarev, V. V.; Dorofeeva, V. A.; Makalkin, A. B.

    2003-06-01

    Visible-range absorption bands at 600-750 nm were recently detected on two Edgeworth-Kuiper Belt (EKB) objects (Boehnhardt et al., 2002). Most probably the spectral features may be attributed to hydrated silicates originated in the bodies. We consider possibilities for silicate dressing and silicate aqueous alteration within them. According to present models of the protoplanetary disk, the temperatures and pressures at the EKB distances (30-50 AU) at the time of formation of the EKB objects (106 to 108 yr) were very low (15-30 K and 10-9-10-10 bar). At these thermodynamic conditions all volatiles excluding hydrogen, helium and neon were in the solid state. An initial mass fraction of silicates (silicates/(ices + dust)) in EKB parent bodies may be estimated as 0.15-0.30. Decay of the short-lived 26Al in the bodies at the early stage of their evolution and their mutual collisions (at velocities >=1.5 km s-1) at the subsequent stage were probably two main sources of their heating, sufficient for melting of water ice. Because of the former process, large EKB bodies (R >= 100 km) could contain a large amount of liquid water in their interiors for the period of a few 106 yr. Freezing of the internal ocean might have begun at ~ 5 × 106 yr after formation of the solar nebula (and CAIs). As a result, aqueous alteration of silicates in the bodies could occur. A probable mechanism of silicate dressing was sedimentation of silicates with refractory organics, resulting in accumulation of large silicate-rich cores. Crushing and removing icy covers under collisions and exposing EKB bodies' interiors with increased silicate content could facilitate detection of phyllosilicate spectral features.

  14. EQUILIBRIUM CONFIGURATIONS OF SYNCHRONOUS BINARIES: NUMERICAL SOLUTIONS AND APPLICATION TO KUIPER BELT BINARY 2001 QG{sub 298}

    SciTech Connect

    Gnat, Orly; Sari, Re'em

    2010-08-20

    We present numerical computations of the equilibrium configurations of tidally locked homogeneous binaries rotating in circular orbits. Unlike the classical Roche approximations, we self-consistently account for the tidal and rotational deformations of both components, and relax the assumptions of ellipsoidal configurations and Keplerian rotation. We find numerical solutions for mass ratios q between 10{sup -3} and 1, starting at a small angular velocity for which tidal and rotational deformations are small, and following a sequence of increasing angular velocities. Each series terminates at an appropriate 'Roche limit', above which no equilibrium solution can be found. Even though the Roche limit is crossed before the 'Roche lobe' is filled, any further increase in the angular velocity will result in mass-loss. For close, comparable-mass binaries, we find that local deviations from ellipsoidal forms may be as large as 10%-20%, and departures from Keplerian rotation are significant. We compute the light curves that arise from our equilibrium configurations, assuming their distance is >>1 AU (e.g., in the Kuiper Belt). We consider both backscatter (proportional to the projected area) and diffuse (Lambert) reflections. Backscatter reflection always yields two minima of equal depths. Diffuse reflection, which is sensitive to the surface curvature, generally gives rise to unequal minima. We find detectable intensity differences of up to 10% between our light curves and those arising from the Roche approximations. Finally, we apply our models to Kuiper Belt binary 2001 QG{sub 298}, and find a nearly edge-on binary with a mass ratio q = 0.93{sup +0.07}{sub -0.03}, angular velocity {omega}{sup 2}/G{rho} = 0.333 {+-} 0.001 (statistical errors only), and pure diffuse reflection. For the observed period of 2001 QG{sub 298}, these parameters imply a bulk density {rho} = 0.72 {+-} 0.04 g cm{sup -3}.

  15. 100 Repetitions

    ERIC Educational Resources Information Center

    Benson, Jeffrey

    2012-01-01

    One hundred repetitions--100 "useful" repetitions. This notion has guided the author's work in alternative education programs for almost 20 years, dealing with the most challenging students, from addicts to conduct-disordered adolescents to traumatized 5th graders. There are no magic tricks. The role of educators is to align with the healthy…

  16. 100 Repetitions

    ERIC Educational Resources Information Center

    Benson, Jeffrey

    2012-01-01

    One hundred repetitions--100 "useful" repetitions. This notion has guided the author's work in alternative education programs for almost 20 years, dealing with the most challenging students, from addicts to conduct-disordered adolescents to traumatized 5th graders. There are no magic tricks. The role of educators is to align with the healthy…

  17. Cold DUst around NEarby Stars (DUNES). First results. A resolved exo-Kuiper belt around the solar-like star ζ2 Ret

    NASA Astrophysics Data System (ADS)

    Eiroa, C.; Fedele, D.; Maldonado, J.; González-García, B. M.; Rodmann, J.; Heras, A. M.; Pilbratt, G. L.; Augereau, J.-Ch.; Mora, A.; Montesinos, B.; Ardila, D.; Bryden, G.; Liseau, R.; Stapelfeldt, K.; Launhardt, R.; Solano, E.; Bayo, A.; Absil, O.; Arévalo, M.; Barrado, D.; Beichmann, C.; Danchi, W.; Del Burgo, C.; Ertel, S.; Fridlund, M.; Fukagawa, M.; Gutiérrez, R.; Grün, E.; Kamp, I.; Krivov, A.; Lebreton, J.; Löhne, T.; Lorente, R.; Marshall, J.; Martínez-Arnáiz, R.; Meeus, G.; Montes, D.; Morbidelli, A.; Müller, S.; Mutschke, H.; Nakagawa, T.; Olofsson, G.; Ribas, I.; Roberge, A.; Sanz-Forcada, J.; Thébault, P.; Walker, H.; White, G. J.; Wolf, S.

    2010-07-01

    We present the first far-IR observations of the solar-type stars δ Pav, HR 8501, 51 Peg and ζ2 Ret, taken within the context of the DUNES Herschel open time key programme (OTKP). This project uses the PACS and SPIRE instruments with the objective of studying infrared excesses due to exo-Kuiper belts around nearby solar-type stars. The observed 100 μm fluxes from δ Pav, HR 8501, and 51 Peg agree with the predicted photospheric fluxes, excluding debris disks brighter than Ldust/Lstar 5 × 10-7 (1σ level) around those stars. A flattened, disk-like structure with a semi-major axis of 100 AU in size is detected around ζ2 Ret. The resolved structure suggests the presence of an eccentric dust ring, which we interpret as an exo-Kuiper belt with Ldust/Lstar ≈ 10-5. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  18. Results on two-, three-, and four-body events from the100Mo+100Mo and120Sn+120Sn collisions around E/A=20 MeV

    NASA Astrophysics Data System (ADS)

    Charity, R. J.; Freifelder, R.; Gobbi, A.; Herrmann, N.; Hildenbrand, K. D.; Rami, F.; Stelzer, H.; Wessels, J. P.; Casini, G.; Maurenzig, P. R.; Olmi, A.; Stefanini, A. A.; Galin, J.; Guerreau, D.; Jahnke, U.; Péghaire, A.; Adloff, J. C.; Bilwes, B.; Bilwes, R.; Rudolf, G.; Petrovici, M.; Gnirs, M.; Pelte, D.

    1991-03-01

    Events with 2, 3 and 4 heavy-fragments ( A≧20) have been detected in the reactions100Mo+100Mo at E/A =18.7, 23.7 MeV and120Sn+120Sn at E/A=18.4 MeV. The experiments were performed with an array of 12 detectors which together covered a large fraction of the forward hemisphere and allowed a high detection efficiency for these events. Masses and energies of all fragments have been reconstructed by means of an improved version of the kinematic coincidence method. The probabilities P 3 and P 4 of producing 3- and 4-body events were found to depend mainly on the dissipated energy rather than on the bombarding energy, thus indicating that their origin lies more in the decay properties of the excited fragments than in the dynamics of the interaction. Emission of light particles from the composite system is shown to become more relevant with increasing bombarding energy and may explain the drop of the P 3 and P 4 curves at high energy losses. Small deviations of the P 3 and P 4 curves at 23.7 A · MeV from those at lower bombarding energies were used to estimate the amount of a possible pre-equilibrium light particle emission as a function of impact parameter.

  19. DIRECT IMAGING AND SPECTROSCOPY OF A YOUNG EXTRASOLAR KUIPER BELT IN THE NEAREST OB ASSOCIATION

    SciTech Connect

    Currie, Thayne; Lisse, Carey M.; Kuchner, Marc; Madhusudhan, Nikku; Kenyon, Scott J.; Thalmann, Christian; Carson, Joseph; Debes, John

    2015-07-01

    We describe the discovery of a bright, young Kuiper belt–like debris disk around HD 115600, a ∼1.4–1.5 M{sub ⊙}, ∼15 Myr old member of the Sco–Cen OB Association. Our H-band coronagraphy/integral field spectroscopy from the Gemini Planet Imager shows the ring has a (luminosity-scaled) semimajor axis of (∼22 AU) ∼ 48 AU, similar to the current Kuiper belt. The disk appears to have neutral-scattering dust, is eccentric (e ∼ 0.1–0.2), and could be sculpted by analogs to the outer solar system planets. Spectroscopy of the disk ansae reveal a slightly blue to gray disk color, consistent with major Kuiper belt chemical constituents, where water ice is a very plausible dominant constituent. Besides being the first object discovered with the next generation of extreme adaptive optics systems (i.e., SCExAO, GPI, SPHERE), HD 115600's debris ring and planetary system provide a key reference point for the early evolution of the solar system, the structure, and composition of the Kuiper belt and the interaction between debris disks and planets.

  20. Kuipers during photo documentation of the fluid and electrical interfaces on the UIA

    NASA Image and Video Library

    2012-01-27

    ISS030-E-156468 (27 Jan. 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, is pictured in the Quest airlock of the International Space Station during photo documentation of the fluid and electrical interfaces on the Umbilical Interface Assembly (UIA) Connector Shelf.

  1. Kuipers sets up the CSA-CP in the U.S. Laboratory

    NASA Image and Video Library

    2012-01-26

    ISS030-E-156455 (26 Jan. 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, sets up the Compound Specific Analyzer - Combustion Products (CSA-CP) in the Destiny laboratory of the International Space Station. The purpose of the analyzer is to measure the concentrations of carbon monoxide, hydrogen cyanide, hydrogen chloride and oxygen.

  2. Kuipers sets up the EHS/TEPC Spectrometer and Detector Assembly in the SM

    NASA Image and Video Library

    2012-03-12

    ISS030-E-177101 (12 March 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, sets up the Environmental Health System / Tissue Equivalent Proportional Counter (EHS/TEPC) spectrometer and detector assembly on panel 327 in the Zvezda Service Module of the International Space Station. The TEPC detector assembly is the primary radiation measurement tool on the space station.

  3. Exploration at the Edge of the Solar System: The Pluto-Kuiper Express Mission (Invited)

    NASA Astrophysics Data System (ADS)

    Terrile, R. J.

    1999-09-01

    The Pluto-Kuiper Express mission is one component of the Outer Planets/Solar Probe Project which is part of the exploration strategy laid out in the Solar System Exploration Roadmap. The first three missions of this project are the Europa Orbiter, Pluto-Kuiper Express and the Solar Probe. All require challenging new technologies and the ability to operate in deep space and at Jupiter. Use of common management and design approaches, avionics, and mission software is planned to reduce the costs of the three missions. The Pluto-Kuiper Express mission is planned to launch in 2004 and is designed to provide the first reconnaissance of the Solar System's most distant planet, Pluto, and it, moon Charon. A gravity assist from Jupiter will allow an 8-year flight time to Pluto and the possibility of encountering one or more Edgeworth-Kuiper Belt objects after the Pluto encounter. The primary science objectives for the mission include characterizing the global geology and geomorphology of Pluto and Charon, mapping their surface composition and characterizing Pluto's neutral atmosphere and its escape rate. This mission is currently soliciting scientific investigations through a NASA Announcement of Opportunity.

  4. Padalka and Kuipers review a procedures book in Node 1 during EXP 9 / EXP 8

    NASA Image and Video Library

    2004-04-22

    ISS008-E-21991 (22 April 2004) --- Cosmonaut Gennady I. Padalka (left), Expedition 9 commander, and European Space Agency (ESA) astronaut Andre Kuipers of the Netherlands, work with one of experiments of the Dutch Expedition for Life Science, Technology and Atmospheric (DELTA) Research in the Unity node of the International Space Station (ISS). Padalka represents Russia’s Federal Space Agency.

  5. Kuipers holds the Plasma-03 experiment container as Foale looks on during Expedition 9 / Expedition 8

    NASA Image and Video Library

    2004-04-29

    ISS008-E-22393 (29 April 2004) --- European Space Agency (ESA) astronaut Andre Kuipers of the Netherlands, holds a Complex “Plasma-03” canister in the Zvezda Service Module of the International Space Station (ISS). Astronaut C. Michael Foale, Expedition 8 commander and NASA ISS science officer, is at right.

  6. Kuipers installs and routes RCS Video Cables in the U.S. Laboratory

    NASA Image and Video Library

    2012-02-01

    ISS030-E-060117 (1 Feb. 2012) --- In the International Space Station?s Destiny laboratory, European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, routes video cable for the High Rate Communication System (HRCS). HRCS will allow for two additional space-to-ground audio channels and two additional downlink video channels.

  7. Splitting of the 520-kilometer seismic discontinuity and chemical heterogeneity in the mantle.

    PubMed

    Saikia, Ashima; Frost, Daniel J; Rubie, David C

    2008-03-14

    Seismic studies indicate that beneath some regions the 520-kilometer seismic discontinuity in Earth's mantle splits into two separate discontinuities (at approximately 500 kilometers and approximately 560 kilometers). The discontinuity near 500 kilometers is most likely caused by the (Mg,Fe)2SiO4 beta-to-gamma phase transformation. We show that the formation of CaSiO3 perovskite from garnet can cause the deeper discontinuity, and by determining the temperature dependence for this reaction we demonstrate that regional variations in splitting of the discontinuity arise from variability in the calcium concentration of the mantle rather than from temperature changes. This discontinuity therefore is sensitive to large-scale chemical heterogeneity. Its occurrence and variability yield regional information on the fertility of the mantle or the proportion of recycled oceanic crust.

  8. Kilometer-Scale Topographic Roughness of Mercury: Correlation with Geologic Features and Units

    NASA Technical Reports Server (NTRS)

    Kreslavsky, Mikhail A.; Head, James W.; Neumann, Gregory A.; Zuber, Maria T.; Smith, David E.

    2014-01-01

    We present maps of the topographic roughness of the northern circumpolar area of Mercury at kilometer scales. The maps are derived from range profiles obtained by the Mercury Laser Altimeter (MLA) instrument onboard the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. As measures of roughness, we used the interquartile range of profile curvature at three baselines: 0.7 kilometers, 2.8 kilometers, and 11 kilometers. The maps provide a synoptic overview of variations of typical topographic textures. They show a dichotomy between the smooth northern plains and rougher, more heavily cratered terrains. Analysis of the scale dependence of roughness indicates that the regolith on Mercury is thicker than on the Moon by approximately a factor of three. Roughness contrasts within northern volcanic plains of Mercury indicate a younger unit inside Goethe basin and inside another unnamed stealth basin. These new data permit interplanetary comparisons of topographic roughness.

  9. Kilometer-Scale Topographic Roughness of Mercury: Correlation with Geologic Features and Units

    NASA Technical Reports Server (NTRS)

    Kreslavsky, Mikhail A.; Head, James W.; Neumann, Gregory A.; Zuber, Maria T.; Smith, David E.

    2014-01-01

    We present maps of the topographic roughness of the northern circumpolar area of Mercury at kilometer scales. The maps are derived from range profiles obtained by the Mercury Laser Altimeter (MLA) instrument onboard the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. As measures of roughness, we used the interquartile range of profile curvature at three baselines: 0.7 kilometers, 2.8 kilometers, and 11 kilometers. The maps provide a synoptic overview of variations of typical topographic textures. They show a dichotomy between the smooth northern plains and rougher, more heavily cratered terrains. Analysis of the scale dependence of roughness indicates that the regolith on Mercury is thicker than on the Moon by approximately a factor of three. Roughness contrasts within northern volcanic plains of Mercury indicate a younger unit inside Goethe basin and inside another unnamed stealth basin. These new data permit interplanetary comparisons of topographic roughness.

  10. Lunar textural analysis based on WAC-derived kilometer-scale roughness and entropy maps

    NASA Astrophysics Data System (ADS)

    Li, Bo; Wang, XueQiang; Zhang, Jiang; Chen, Jian; Ling, Zongcheng

    2016-06-01

    In general, textures are thought to be some complicated repeated patterns formed by elements, or primitives which are sorted in certain rules. Lunar surfaces record the interactions between its outside environment and itself, thus, based on high-resolution DEM model or image data, there are some topographic features which have different roughness and entropy values or signatures on lunar surfaces. Textures of lunar surfaces can help us to concentrate on typical topographic and photometric variations and reveal the relationships between obvious features (craters, impact basins, sinuous rilles (SRs) and ridges) with resurfacing processes on the Moon. In this paper, the term surface roughness is an expression of the variability of a topographic or photometric surface at kilometer scale, and the term entropy can characterize the variability inherent in a geological and topographic unit and evaluate the uncertainty of predictions made by a given geological process. We use the statistical moments of gray-level histograms in different-sized neighborhoods (e.g., 3, 5, 10, 20, 40 and 80 pixels) to compute the kilometer-scale roughness and entropy values, using the mosaic image from 70°N to 70°S obtained by Lunar Reconnaissance Orbiter (LRO) Wide Angle Camera (WAC). Large roughness and entropy signatures were only found in the larger scale maps, while the smallest 3-pixel scale map had more disorderly and unsystematic textures. According to the entropy values in 10-pixel scale entropy map, we made a frequency curve and categorized lunar surfaces into three types, shadow effects, maria and highlands. A 2D scatter plot of entropy versus roughness values was produced and we found that there were two point clusters corresponding to the highlands and maria, respectively. In the last, we compared the topographic and photometric signatures derived from Lunar Orbiter Laser Altimeter (LOLA) data and WAC mosaic image. On the lunar surfaces, the ridges have obvious multilevel

  11. Optical properties of (Se{sub 80}Te{sub 20}){sub 100−x}Ag{sub x} (0 ≤ x ≤ 4) thin films

    SciTech Connect

    Singh, D. Kumar, S. Sandhu, S. Thangaraj, R.

    2014-04-24

    Thin films of (Se{sub 80}Te{sub 20}){sub 100−x}Ag{sub x} (0 ≤ x ≤ 4) glasses were prepared by thermal evaporation of the bulk samples. The transmittance (T) and reflection (R) spectra of amorphous thin films were obtained in the spectral region in the range 400–2500 nm. The optical band gap (E{sub g}) has been determined by Tauc’s extrapolation method. The surface morphology has been determined by the Scanning Electron Microscopy (SEM)

  12. The Color Distribution in the Edgeworth-Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Doressoundiram, A.; Peixinho, N.; de Bergh, C.; Fornasier, S.; Thébault, P.; Barucci, M. A.; Veillet, C.

    2002-10-01

    In 1997 we began the Meudon Multicolor Survey of Outer Solar System Objects with the aim of collecting a large and homogeneous set of color data for trans-Neptunian objects (TNOs) and Centaurs. Here we present our latest B-V, V-R, and R-I color measurements obtained with the CFH12K mosaic camera of the 3.6 m Canada-France-Hawaii Telescope. With the colors of 30 objects reported in this work, we have a combined sample of 52 B-R color measurements for eight Centaurs, 22 classical TNOs, 13 Plutinos, eight scattered objects, and one object of unidentified dynamical class. This is the largest single and homogeneous data set published to date, and it is large enough to search for compositional structures, interrelations between dynamical classes of objects, and correlations with physical and orbital parameters. The color-color diagrams show that all the classes of objects share the same wide color diversity. No significant correlations are seen for the whole population of TNOs and Centaurs, or for individual subpopulations, except for the classical objects. Indeed, we found a significant and strong correlation of the colors of classical TNOs with inclination, eccentricity, and perihelion, but nothing with semimajor axis and absolute magnitude. Most of these results are common to previous works and do not seem to be due to sampling bias. Moreover, a strong correlation with mean excitation velocity [VK(e2+i2)1/2] points toward a space weathering or impact origin for the color diversity. However, thorough modeling of the collisional/dynamical environment in the Edgeworth-Kuiper belt needs to be done in order to confirm this scenario. We found also that the classical TNOs are made up of a superposition of two distinct populations: the dynamically cold classical TNOs (red colors, low i, small sizes) and the dynamically hot classical TNOs (diverse colors, moderate and high i, larger sizes). Furthermore, the latter population displays a strong correlation between color and mean

  13. Warm exo-Zodi from cool exo-Kuiper belts: the significance of P-R drag and the inference of intervening planets

    NASA Astrophysics Data System (ADS)

    Kennedy, Grant M.; Piette, Anjali

    2015-05-01

    Poynting-Robertson (P-R) drag has been considered an ineffective mechanism for delivering dust to regions interior to the cool Kuiper belt analogues seen around other Sun-like stars. This conclusion is however based on the very large contrast in dust optical depth between the parent belt and the interior regions that results from the dominance of collisions over drag in systems with detectable cool belts. Here, we show that the levels of habitable zone dust arising from detectable Kuiper belt analogues can be tens to a few hundreds of times greater than the optical depth in the Solar Zodiacal cloud. Dust enhancements of more than a few tens of `zodi' are expected to hinder future Earth-imaging missions, but relatively few undetectable Kuiper belts result in such levels, particularly around stars older than a few Gyr. Thus, current mid- to far-IR photometric surveys have already identified most of the 20-25 per cent of nearby stars where P-R drag from outer belts could seriously impact Earth-imaging. The Large Binocular Telescope Interferometer should easily detect such warm dust around many nearby stars with outer belts, and will provide insight into currently unclear details of the competition between P-R drag and collisions. Given sufficient confidence in future models, the inevitability of P-R drag means that the non-detection of warm dust where detectable levels were expected could be used to infer additional dust removal process, the most likely being the presence of intervening planets.

  14. High-frequency magnetic permeability of single- and multilayered (Co41Fe39B20) x (SiO2)100- x nanocomposites

    NASA Astrophysics Data System (ADS)

    Tarasova, O. S.; Sitnikov, A. V.; Kalinin, Yu. E.; Starostenko, S. N.; Granovskii, A. B.

    2016-12-01

    Thin film single-layered (Co41Fe39B20) x (SiO2)100- x nanocomposites at x = 30-80 at % and multilayered nanocomposites composed of 176 pairs of [(Co41Fe39B20)60(SiO2)40]/[(Co41Fe39B20)60(SiO2)40 + O2] have been prepared via ion-beam sputtering of the complex target. The concentration dependences of the magnetic permeability of single-layered films at a frequency of 50 MHz are characterized by maximum losses near x = 60 at %, whereas the percolation threshold with respect to the electric conductivity is x = 50 at %. The high-frequency magnetic permeability of films has been measured by the resonator method in the frequency range of 0.1—10 GHz. As is shown, while the single-layer film passes to the multilayered structure, the ferromagnetic resonance frequency shifts from 1.5 to 2.5 GHz, and the imaginary part of the magnetic permeability attains 200 that is presumably due to the inhibition of the perpendicular magnetic anisotropy component.

  15. Saturn - Enceladus from a distance of 119,000 kilometers (74,000 miles)

    NASA Technical Reports Server (NTRS)

    1981-01-01

    This Voyager 2 mosaic of Enceladus was made from images taken through the clear, violet and green filters Aug. 25, 1981, from a distance of 119,000 kilometers (74,000 miles). In many ways, the surface of this satellite of Saturn resembles that of Jupiter's Galilean satellite Ganymede. Enceladus, however, is only one-tenth Ganymede's size. Some regions of Enceladus show impact craters up to 35 kilometers (22 miles) in diameter, whereas other areas are smooth and uncratered. Linear sets of grooves tens of kilometers long traverse the surface and are probably faults resulting from deformation of the crust. The uncratered regions are geologically young and suggest that Enceladus has experienced a period of relatively recent internal melting. The rims of several craters near the lower center of the picture have been flooded by the smooth terrain. The satellite is about 500 kilometers (310 miles) in diameter and has the brightest and whitest surface of any of Saturn's satellites. Features as small as 2 kilometers (1.2 miles) are visible in this highest-resolution view of Enceladus. The Voyager project is managed for NASA by the Jet Propulsion Laboratory, Pasadena, Calif.

  16. Final report on APMP key comparison of volume of liquids at 20 L and 100 mL: APMP.M.FF-K4

    NASA Astrophysics Data System (ADS)

    Man, John; Arias, Roberto; Terao, Yoshiya; Lee, Yong Jae; Ligong, Guo; Tulasombut, Verra; Chan, Tak Kin; Thai, Nguyen Hong; Steyn, Ronel; Sampath, H. L. I. S.

    2011-01-01

    This report presents the results of a key comparison of liquid volume measurement conducted between ten participating institutes during the period July 2006 to August 2008 within the framework of the Asia Pacifica Metrology Program (APMP). The transfer standards comprised one 20 L volume measure and two 100 mL glass pycnometers. These transfer standards had been used in a similar CIPM key comparison CCM.FF-K4 in 2003 to 2005. The pilot institute was the National Measurement Institute, Australia (NMIA), which together with CENAM act as link laboratories to the CCM.FF-K4 comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  17. Resting cells of microorganisms in the 20-100 μm fraction of marine sediments in an Antarctic coastal area

    NASA Astrophysics Data System (ADS)

    Ichinomiya, Mutsuo; Nakamachi, Miwa; Fukuchi, Mitsuo; Taniguchi, Akira

    We investigated the morphological features, vertical sinking fluxes, and number densities of the resting cells of ice-associated microorganisms in the 20-100 μm fraction of natural marine sediments collected from ice-covered and ice-free areas around Syowa Station, Lützow-Holm Bay, East Antarctica. We identified the resting cells of various taxonomic groups, including the spores of a diatom, cysts of three dinoflagellates, cysts of five oligotrich ciliates, and the eggs of a mesozooplankton. This is the first report of oligotrich ciliate cysts from Antarctic waters. The resting spores of Thalassiosira australis (diatom), cysts of Polarella glacialis (dinoflagellate), and egg type 1 sink to the bottom sediment during summer. Our results suggest that some planktonic and ice-associated microorganisms in Antarctic coastal areas send their resting cells to the bottom sediments as seed populations for the following generation.

  18. Solubility relations in the ternary system NaCl-CsCl-H2O at 1 atm. 1. Solubilities of halite from 20 to 100 °C

    USGS Publications Warehouse

    Chou, I.-Ming; Lee, R.D.

    1983-01-01

    Solubilities of halite in the ternary system NaCl-CsCl-H2O have been determined by the visual polythermal method at 1 atm from 20 to 100??C along five constant CsCl/(CsCl + H2O) weight ratio lines. These five constant weight ratios are 0.1, 0.2, 0.3, 0.4, and 0.5. The maximum uncertainties in these measurements are ??0.02 wt % NaCl and ??0.15??C. The data along each constant CsCl/(CsCl + H2O) weight ratio line were regressed to a smooth curve. The maximum deviation of the measured solubilities from the smooth curves is 0.06 wt % NaCl. Isothermal solubilities of halite were calculated from smoothed curves at 25, 50, and 75??C.

  19. One-year outcome after Descemet membrane endothelial keratoplasty (DMEK) comparing sulfur hexafluoride (SF6) 20% versus 100% air for anterior chamber tamponade.

    PubMed

    Schaub, Friederike; Enders, Philip; Snijders, Katharina; Schrittenlocher, Silvia; Siebelmann, Sebastian; Heindl, Ludwig M; Bachmann, Björn O; Cursiefen, Claus

    2017-07-01

    To investigate 1-year clinical outcome and complication rates following Descemet membrane endothelial keratoplasty (DMEK) with sulfur hexafluoride 20% (SF620%) anterior chamber tamponade compared with conventionally used 100% air for primary graft attachment during DMEK surgery. Records of 1112 consecutive DMEKs were reviewed retrospectively and grouped by anterior chamber tamponade used during DMEK surgery (SF620% vs 100% air). Outcome measures included intraocular pressure (IOP), best spectacle-corrected visual acuity (BSCVA), endothelial cell density (ECD) and central corneal thickness (CCT) at 1, 3, 6 and 12 months after DMEK surgery. Complication rates were assessed, including intraoperative and postoperative complications, and graft detachment rate requiring rebubbling. A total of 854 cases were included in this study. In 105 cases (12.3%), DMEK was performed with SF620%, and in 749 cases (87.7%) 100% air was used for anterior chamber tamponade. Outcome results for IOP, BSCVA, ECD and CCT at all follow-up time points were comparable for both anterior chamber tamponade groups without statistical significant differences (p≥0.05), but graft detachment rate requiring rebubbling was significantly lower in the SF620% group (p<0.001). Whereas SF620% anterior chamber tamponade does not seem to negatively affect the clinical outcome of DMEK surgery within the first postoperative year, use of SF620% significantly reduces the rate of rebubblings. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  20. Texture descriptions of lunar surface derived from LOLA data: Kilometer-scale roughness and entropy maps

    NASA Astrophysics Data System (ADS)

    Li, Bo; Ling, Zongcheng; Zhang, Jiang; Chen, Jian; Wu, Zhongchen; Ni, Yuheng; Zhao, Haowei

    2015-11-01

    The lunar global texture maps of roughness and entropy are derived at kilometer scales from Digital Elevation Models (DEMs) data obtained by Lunar Orbiter Laser Altimeter (LOLA) aboard on Lunar Reconnaissance Orbiter (LRO) spacecraft. We use statistical moments of a gray-level histogram of elevations in a neighborhood to compute the roughness and entropy value. Our texture descriptors measurements are shown in global maps at multi-sized square neighborhoods, whose length of side is 3, 5, 10, 20, 40 and 80 pixels, respectively. We found that large-scale topographical changes can only be displayed in maps with longer side of neighborhood, but the small scale global texture maps are more disorderly and unsystematic because of more complicated textures' details. Then, the frequency curves of texture maps are made out, whose shapes and distributions are changing as the spatial scales increases. Entropy frequency curve with minimum 3-pixel scale has large fluctuations and six peaks. According to this entropy curve we can classify lunar surface into maria, highlands, different parts of craters preliminarily. The most obvious textures in the middle-scale roughness and entropy maps are the two typical morphological units, smooth maria and rough highlands. For the impact crater, its roughness and entropy value are characterized by a multiple-ring structure obviously, and its different parts have different texture results. In the last, we made a 2D scatter plot between the two texture results of typical lunar maria and highlands. There are two clusters with largest dot density which are corresponded to the lunar highlands and maria separately. In the lunar mare regions (cluster A), there is a high correlation between roughness and entropy, but in the highlands (Cluster B), the entropy shows little change. This could be subjected to different geological processes of maria and highlands forming different landforms.

  1. Five-Kilometers Time Trial: Preliminary Validation of a Short Test for Cycling Performance Evaluation

    PubMed Central

    Dantas, Jose Luiz; Pereira, Gleber; Nakamura, Fabio Yuzo

    2015-01-01

    Background: The five-kilometer time trial (TT5km) has been used to assess aerobic endurance performance without further investigation of its validity. Objectives: This study aimed to perform a preliminary validation of the TT5km to rank well-trained cyclists based on aerobic endurance fitness and assess changes of the aerobic endurance performance. Materials and Methods: After the incremental test, 20 cyclists (age = 31.3 ± 7.9 years; body mass index = 22.7 ± 1.5 kg/m2; maximal aerobic power = 360.5 ± 49.5 W) performed the TT5km twice, collecting performance (time to complete, absolute and relative power output, average speed) and physiological responses (heart rate and electromyography activity). The validation criteria were pacing strategy, absolute and relative reliability, validity, and sensitivity. Sensitivity index was obtained from the ratio between the smallest worthwhile change and typical error. Results: The TT5km showed high absolute (coefficient of variation < 3%) and relative (intraclass coefficient correlation > 0.95) reliability of performance variables, whereas it presented low reliability of physiological responses. The TT5km performance variables were highly correlated with the aerobic endurance indices obtained from incremental test (r > 0.70). These variables showed adequate sensitivity index (> 1). Conclusions: TT5km is a valid test to rank the aerobic endurance fitness of well-trained cyclists and to differentiate changes on aerobic endurance performance. Coaches can detect performance changes through either absolute (± 17.7 W) or relative power output (± 0.3 W.kg-1), the time to complete the test (± 13.4 s) and the average speed (± 1.0 km.h-1). Furthermore, TT5km performance can also be used to rank the athletes according to their aerobic endurance fitness. PMID:26448846

  2. Five-Kilometers Time Trial: Preliminary Validation of a Short Test for Cycling Performance Evaluation.

    PubMed

    Dantas, Jose Luiz; Pereira, Gleber; Nakamura, Fabio Yuzo

    2015-09-01

    The five-kilometer time trial (TT5km) has been used to assess aerobic endurance performance without further investigation of its validity. This study aimed to perform a preliminary validation of the TT5km to rank well-trained cyclists based on aerobic endurance fitness and assess changes of the aerobic endurance performance. After the incremental test, 20 cyclists (age = 31.3 ± 7.9 years; body mass index = 22.7 ± 1.5 kg/m(2); maximal aerobic power = 360.5 ± 49.5 W) performed the TT5km twice, collecting performance (time to complete, absolute and relative power output, average speed) and physiological responses (heart rate and electromyography activity). The validation criteria were pacing strategy, absolute and relative reliability, validity, and sensitivity. Sensitivity index was obtained from the ratio between the smallest worthwhile change and typical error. The TT5km showed high absolute (coefficient of variation < 3%) and relative (intraclass coefficient correlation > 0.95) reliability of performance variables, whereas it presented low reliability of physiological responses. The TT5km performance variables were highly correlated with the aerobic endurance indices obtained from incremental test (r > 0.70). These variables showed adequate sensitivity index (> 1). TT5km is a valid test to rank the aerobic endurance fitness of well-trained cyclists and to differentiate changes on aerobic endurance performance. Coaches can detect performance changes through either absolute (± 17.7 W) or relative power output (± 0.3 W.kg(-1)), the time to complete the test (± 13.4 s) and the average speed (± 1.0 km.h(-1)). Furthermore, TT5km performance can also be used to rank the athletes according to their aerobic endurance fitness.

  3. The structure of NGC at 100, 160, and 200 microns - Continuum dust emission in a quiescent Sb galaxy

    NASA Technical Reports Server (NTRS)

    Engargiola, G.; Harper, D. A.

    1992-01-01

    Observations of NGC 4565 at 100, 160, and 200 microns with the University of Chicago Far-Infrared Camera and the NASA-Kuiper Airborne Observatory are reported. In order to examine the dependence of FIR emission on spiral structure and star formation activity, these observations of NGC 4565, a quiescent Sb galaxy, are compared with observations of NGC 6946, an active Sc galaxy, made by Engargiola (1991) using the same instruments. Warm dust (30 K) in a bisymmetric spiral pattern superposed on an exponential disk of cool dust (20 K) can account for the FIR morphology of NGC 4565. Optical and IR data suggest that there are more embedded sources heating dust locally in the southeast arm region and more UV radiation from unobscured young stellar associations heating the cool, neutral medium in the northeast arm region.

  4. Studies of extra-solar Oort clouds and the Kuiper disk

    NASA Technical Reports Server (NTRS)

    Stern, S. Alan

    1996-01-01

    We are conducting research designed to enhance our understanding of the evolution and detectability of comet clouds and disks. According to 'standard' theory, both the Kuiper Belt and the Oort Cloud are (at least in part) natural products of the planetary accumulation stage of solar system formation. One expects such assemblages to be a common attribute of other solar systems. Therefore, searches for comet disks and clouds orbiting other stars offer a new method for inferring the presence of planetary systems. This project consists of two efforts: (1) observational work to predict and search for the signatures of Oort Clouds and comet disks around other stars; and (2) modelling studies of the formation and evolution of the Kuiper Belt (KB) and similar assemblages that may reside around other stars, including beta Pic.

  5. KUIPER BELT OBJECT OCCULTATIONS: EXPECTED RATES, FALSE POSITIVES, AND SURVEY DESIGN

    SciTech Connect

    Bickerton, S. J.; Welch, D. L.; Kavelaars, J. J. E-mail: welch@physics.mcmaster.ca

    2009-05-15

    A novel method of generating artificial scintillation noise is developed and used to evaluate occultation rates and false positive rates for surveys probing the Kuiper Belt with the method of serendipitous stellar occultations. A thorough examination of survey design shows that (1) diffraction-dominated occultations are critically (Nyquist) sampled at a rate of 2 Fsu{sup -1}, corresponding to 40 s{sup -1} for objects at 40 AU, (2) occultation detection rates are maximized when targets are observed at solar opposition, (3) Main Belt asteroids will produce occultations light curves identical to those of Kuiper Belt Objects (KBOs) if target stars are observed at solar elongations of: 116{sup 0} {approx}< {epsilon} {approx}< 125 deg., or 131 deg. {approx}< {epsilon} {approx}< 141 deg., and (4) genuine KBO occultations are likely to be so rare that a detection threshold of {approx}>7-8{sigma} should be adopted to ensure that viable candidate events can be disentangled from false positives.

  6. Kuiper Belt Object Orbiter Using Advanced Radioisotope Power Sources and Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; McGuire, Melissa L.; Dankanich, John; Colozza, Anthony; Schmitz, Paul; Khan, Omair; Drexler, Jon; Fittje, James

    2011-01-01

    A joint NASA GRC/JPL design study was performed for the NASA Radioisotope Power Systems Office to explore the use of radioisotope electric propulsion for flagship class missions. The Kuiper Belt Object Orbiter is a flagship class mission concept projected for launch in the 2030 timeframe. Due to the large size of a flagship class science mission larger radioisotope power system building blocks were conceptualized to provide the roughly 4 kW of power needed by the NEXT ion propulsion system and the spacecraft. Using REP the spacecraft is able to rendezvous with and orbit a Kuiper Belt object in 16 years using either eleven (no spare) 420 W advanced RTGs or nine (with a spare) 550 W advanced Stirling Radioisotope systems. The design study evaluated integrating either system and estimated impacts on cost as well as required General Purpose Heat Source requirements.

  7. Sub-Kilometer Asteroid Diameter Survey (SKADS) V1.0

    NASA Astrophysics Data System (ADS)

    Gladman, B. J.; Davis, D. R.; Neese, C.; Jedicke, R.; Williams, G.; Kavelaars, J. J.; Petit, J.-M.; Scholl, H.; Holman, M.; Warrington, B.; Esquerdo, G.; Tricarico, P.

    2010-05-01

    The Sub-Kilometer Asteroid Diameter Survey (SKADS) (Gladman et al. 2009) acquired good-quality orbital and absolute magnitude (H) determinations for a sample of small main-belt asteroids in order to study the orbital and size distribution beyond H = 15, down to sub-kilometer sizes (H > 18). Based on six observing nights over an 11-night baseline, SKADS detected, measured photometry for, and linked observations of 1087 asteroids which have one-week time baselines or more. This data set contains the astrometry, photometry, and orbits of the 1087 asteroids detected by SKADS.

  8. A detailed map of the 660-kilometer discontinuity beneath the izu-bonin subduction zone.

    PubMed

    Wicks, C W; Richards, M A

    1993-09-10

    Dynamical processes in the Earth's mantle, such as cold downwelling at subduction zones, cause deformations of the solid-state phase change that produces a seismic discontinuity near a depth of 660 kilometers. Observations of short-period, shear-to-compressional wave conversions produced at the discontinuity yield a detailed map of deformation beneath the Izu-Bonin subduction zone. The discontinuity is depressed by about 60 kilometers beneath the coldest part of the subducted slab, with a deformation profile consistent with the expected thermal signature of the slab, the experimentally determined Clapeyron slope of the phase transition, and the regional tectonic history.

  9. A SOUTHERN SKY AND GALACTIC PLANE SURVEY FOR BRIGHT KUIPER BELT OBJECTS

    SciTech Connect

    Sheppard, Scott S.; Udalski, Andrzej; Kubiak, Marcin; Pietrzynski, Grzegorz; Poleski, Radoslaw; Soszynski, Igor; Szymanski, Michal K.; Ulaczyk, Krzysztof; Trujillo, Chadwick

    2011-10-15

    About 2500 deg{sup 2} of sky south of declination -25{sup 0} and/or near the Galactic Plane were surveyed for bright outer solar system objects. This survey is one of the first large-scale southern sky and Galactic Plane surveys to detect dwarf planets and other bright Kuiper Belt Objects in the trans-Neptunian region. The survey was able to obtain a limiting R-band magnitude of 21.6. In all, 18 outer solar system objects were detected, including Pluto which was detected near the Galactic center using optimal image subtraction techniques to remove the high stellar density background. Fourteen of the detections were previously unknown trans-Neptunian objects, demonstrating that the southern sky had not been well searched to date for bright outer solar system objects. Assuming moderate albedos, several of the new discoveries from this survey could be in hydrostatic equilibrium and thus could be considered dwarf planets. Combining this survey with previous surveys from the northern hemisphere suggests that the Kuiper Belt is nearly complete to around 21st magnitude in the R band. All the main dynamical classes in the Kuiper Belt are occupied by at least one dwarf-planet-sized object. The 3:2 Neptune resonance, which is the innermost well-populated Neptune resonance, has several large objects while the main outer Neptune resonances such as the 5:3, 7:4, 2:1, and 5:2 do not appear to have any large objects. This indicates that the outer resonances are either significantly depleted in objects relative to the 3:2 resonance or have a significantly different assortment of objects than the 3:2 resonance. For the largest objects (H < 4.5 mag), the scattered disk population appears to have a few times more objects than the main Kuiper Belt (MKB) population, while the Sedna population could be several times more than that of the MKB.

  10. A Southern Sky and Galactic Plane Survey for Bright Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott S.; Udalski, Andrzej; Trujillo, Chadwick; Kubiak, Marcin; Pietrzynski, Grzegorz; Poleski, Radoslaw; Soszynski, Igor; Szymański, Michal K.; Ulaczyk, Krzysztof

    2011-10-01

    About 2500 deg2 of sky south of declination -25° and/or near the Galactic Plane were surveyed for bright outer solar system objects. This survey is one of the first large-scale southern sky and Galactic Plane surveys to detect dwarf planets and other bright Kuiper Belt Objects in the trans-Neptunian region. The survey was able to obtain a limiting R-band magnitude of 21.6. In all, 18 outer solar system objects were detected, including Pluto which was detected near the Galactic center using optimal image subtraction techniques to remove the high stellar density background. Fourteen of the detections were previously unknown trans-Neptunian objects, demonstrating that the southern sky had not been well searched to date for bright outer solar system objects. Assuming moderate albedos, several of the new discoveries from this survey could be in hydrostatic equilibrium and thus could be considered dwarf planets. Combining this survey with previous surveys from the northern hemisphere suggests that the Kuiper Belt is nearly complete to around 21st magnitude in the R band. All the main dynamical classes in the Kuiper Belt are occupied by at least one dwarf-planet-sized object. The 3:2 Neptune resonance, which is the innermost well-populated Neptune resonance, has several large objects while the main outer Neptune resonances such as the 5:3, 7:4, 2:1, and 5:2 do not appear to have any large objects. This indicates that the outer resonances are either significantly depleted in objects relative to the 3:2 resonance or have a significantly different assortment of objects than the 3:2 resonance. For the largest objects (H < 4.5 mag), the scattered disk population appears to have a few times more objects than the main Kuiper Belt (MKB) population, while the Sedna population could be several times more than that of the MKB.

  11. New Horizons Science Photos from NASA's Pluto-Kuiper Belt Mission

    DOE Data Explorer

    DOE provided the power supply for NASA's New Horizons Mission, a mission to the Pluto and Charon, a double-planet system, and the Kuiper Belt. There are science photos posted on the New Horizons website, along with mission photos, spacecraft images, launch photos, posters and renderings that are both scientific and artistic. The images can be searched by keywords, by date, or by subject topic. They can also be browsed as an entire list. Each image has a detailed description.

  12. Foale and Kuipers work at the MSG during EXP 8 / EXP 9

    NASA Image and Video Library

    2004-04-22

    ISS008-E-21999 (22 April 2004) --- Astronaut C. Michael Foale (foreground), Expedition 8 commander and NASA ISS science officer, and European Space Agency (ESA) astronaut Andre Kuipers of the Netherlands work with the HEAT experiment in the Microgravity Science Glovebox (MSG) in the Destiny laboratory of the International Space Station (ISS). The main aim of the HEAT technology demonstration is the characterization of the heat transfer performance of a grooved heat pipe in weightlessness.

  13. Studies of extra-solar OORT clouds and the Kuiper disk

    NASA Technical Reports Server (NTRS)

    Stern, S. Alan

    1993-01-01

    This is the second report for NAGW-3023, Studies of Extra-Solar Oort Clouds and the Kuiper Disk. We are conducting research designed to enhance our understanding of the evolution and detectability of comet clouds and disks. This area holds promise for also improving our understanding of outer solar system formation, the bombardment history of the planets, the transport of volatiles and organics from the outer solar system to the inner planets, and the ultimate fate of comet clouds around the Sun and other stars. According to 'standard' theory, both the Kuiper Disk and Oort Cloud are (at least in part) natural products of the planetary accumulation stage of solar system formation. One expects such assemblages to be a common attribute of other solar systems. Therefore, searches for comet disks and clouds orbiting other stars offer a new method for infering the presence of planetary systems. Our three-year effort consists of two major efforts: (1) observational work to predict and search for the signatures of Oort Clouds and comet disks around other stars; and (2) modelling studies of the formation and evolution of the Kuiper Disk (KD) and similar assemblages that may reside around other stars, including Beta Pic. These efforts are referred to as Task 1 and 2, respectively.

  14. Studies of extra-solar Oort Clouds and the Kuiper Disk

    NASA Technical Reports Server (NTRS)

    Stern, Alan

    1995-01-01

    This is the September 1995 Semi-Annual report for Studies of Extra-Solar Oort Clouds and the Kuiper Disk. We are conducting research designed to enhance our understanding of the evolution and detectability of comet clouds and disks. This area holds promise for also improving our understanding of outer solar system formation the bombardment history of the planets, the transport of volatiles and organics from the outer solar system to the inner planets, and to the ultimate fate of comet clouds around the Sun and other stars. According to 'standard' theory, both the Kuiper Disk and the Oort Cloud are (at least in part) natural products of the planetary accumulation stage of solar system formation. One expects such assemblages to be a common attribute of other solar systems. Therefore, searches for comet disks and clouds orbiting other stars offer a new method for inferring the presence of planetary systems. This project consists of two major efforts: (1) observational work to predict and search for the signatures of Oort Clouds and comet disks around other stars; and (2) modelling studies of the formation and evolution of the Kuiper Disk (KD) and similar assemblages that may reside around other stars, including beta Pic. These efforts are referred to as Task 1 and 2.

  15. The impact of accretion material composition and properties on interior structure dynamics of Kuiper belt objects

    NASA Astrophysics Data System (ADS)

    Shchuko, Oleg; Shchuko, Svetlana D.; Kartashov, Daniil; Orosei, Roberto

    The building material of the forming Kuiper belt objects is supposed in the model to consist of solid dust material of protosolar cloud fringe regions and H2 O amorphous ice. A spheri-cally symmetric celestial body was being created as a result of accretion. The body's internal structure was determined by the composition and the properties of the accretion material and the evolution of the structure -by internal thermal processes. The accretion material compo-sition and structure have been studied, which provide now the existence of large icy Kuiper belt objects. Radionuclides 26 Al, 40 K, 232 Th, 235 U and 238 U embedded in solid dust matter particles have been main sources of radiogenic heat for the Kuiper belt object life time. The impact of the heat-and-power potentials of radiogenic heat sources on H2 O phase transition dynamics in the celestial body matter has been investigated. The parameter variation domains of these potentials have been found at which there can be formed areas partly or fully filled with H2 O of different phase states. In addition, the dynamic boundaries of areas have been determined where the ice component is presented by amorphous ice or cubic and hexagonal crystal ice. The parameter domains of celestial body accretion and radiogenic heat processes have been determined where the body evolution may have a catastrophic scenario up to its complete destruction.

  16. Properties of the Distant Kuiper Belt: Results from the Palomar Distant Solar System Survey

    NASA Astrophysics Data System (ADS)

    Schwamb, Megan E.; Brown, Michael E.; Rabinowitz, David L.; Ragozzine, Darin

    2010-09-01

    We present the results of a wide-field survey using the 1.2 m Samuel Oschin Telescope at Palomar Observatory. This survey was designed to find the most distant members of the Kuiper Belt and beyond. We searched ~12,000 deg2 down to a mean limiting magnitude of 21.3 in R. A total number of 52 Kuiper Belt objects and Centaurs have been detected, 25 of which were discovered in this survey. Except for the redetection of Sedna, no additional Sedna-like bodies with perihelia greater than 45 AU were detected despite sensitivity out to distances of 1000 AU. We discuss the implications for a distant Sedna-like population beyond the Kuiper Belt, focusing on the constraints we can place on the embedded stellar cluster environment the early Sun may be have been born in, where the location and distribution of Sedna-like orbits sculpted by multiple stellar encounters is indicative of the birth cluster size. We also report our observed latitude distribution and implications for the size of the plutino population.

  17. Searching for Extreme Kuiper Belt Objects and Inner Oort Cloud Objects

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott S.; Trujillo, Chad; Tholen, Dave

    2015-11-01

    Since late 2012 we have been performing the largest and deepest survey for distant solar system objects. In the nearly one thousand square degrees we have covered so far we have discovered the object with the most distant perihelion known (2012 VP113), several extreme Kuiper Belt objects with moderate perihelia and large eccentricities, one of the top ten intrinsically brightest Trans-Neptunian objects, an ultra-wide Kuiper Belt binary, one of the most distant known active comets and two active asteroids in the main belt of asteroids. The Kuiper Belt population has an outer edge at about 50 AU. Sedna and our recent discovery, 2012 VP113, are the only known objects with perihelia significantly beyond this edge at about 80 AU. These inner Oort cloud objects obtained their orbits when the solar system was vastly different from now. Thus the dynamical and physical properties of objects in this region offer key constraints on the formation and evolution of our solar system. We will discuss the most recent results of our survey.

  18. Formation of Kuiper-belt binaries by dynamical friction and three-body encounters.

    PubMed

    Goldreich, Peter; Lithwick, Yoram; Sari, Re'em

    2002-12-12

    The Kuiper belt is a disk of icy bodies that orbit the Sun beyond Neptune; the largest known members are Pluto and its companion Charon. A few per cent of Kuiper-belt bodies have recently been found to be binaries with wide separations and mass ratios of the order of unity. Collisions were too infrequent to account for the observed number of binaries, implying that these binaries formed through collisionless interactions mediated by gravity. These interactions are likely to have been most effective during the period of runaway accretion, early in the Solar System's history. Here we show that a transient binary forms when two large bodies penetrate one another's Hill sphere (the region where their mutual forces are larger than the tidal force of the Sun). The loss of energy needed to stabilize the binary orbit can then occur either through dynamical friction from surrounding small bodies, or through the gravitational scattering of a third large body. Our estimates slightly favour the former mechanism. We predict that five per cent of Kuiper-belt objects are binaries with apparent separations greater than 0.2 arcsec, and that most are in tighter binaries or systems of higher multiplicity.

  19. The Phase Space Structure Near Neptune Resonances in the Kuiper Belt

    NASA Technical Reports Server (NTRS)

    Malhotra, Renu

    1996-01-01

    The Solar system beyond Neptune is believed to house a population of small primordial bodies left over from the planet formation process. The region up to heliocentric distance -50 AU (a.k.a. the Kuiper Belt) may be the source of the observed short-period comets. In this region, the phase space structure near orbital resonances with Neptune is of special interest for the long-term stability of orbits. There is reason to believe that a significant fraction (perhaps most) of the Kuiper Belt objects reside preferentially in these resonance locations. This paper describes the dynamics of small objects near the major orbital resonances with Neptune. Estimates of the widths of stable resonance zones as well as the properties of resonant orbits are obtained from the circular, planar restricted three-body model. Although this model does not contain the full complexity of the long-term orbital dynamics of Kuiper Belt objects subject to the full N-body perturbations of all the planets, it does provide a baseline for the phase space structure and properties of resonant orbits in the trans-Neptunian Solar system.

  20. PROPERTIES OF THE DISTANT KUIPER BELT: RESULTS FROM THE PALOMAR DISTANT SOLAR SYSTEM SURVEY

    SciTech Connect

    Schwamb, Megan E.; Brown, Michael E.; Rabinowitz, David L.; Ragozzine, Darin

    2010-09-10

    We present the results of a wide-field survey using the 1.2 m Samuel Oschin Telescope at Palomar Observatory. This survey was designed to find the most distant members of the Kuiper Belt and beyond. We searched {approx}12,000 deg{sup 2} down to a mean limiting magnitude of 21.3 in R. A total number of 52 Kuiper Belt objects and Centaurs have been detected, 25 of which were discovered in this survey. Except for the redetection of Sedna, no additional Sedna-like bodies with perihelia greater than 45 AU were detected despite sensitivity out to distances of 1000 AU. We discuss the implications for a distant Sedna-like population beyond the Kuiper Belt, focusing on the constraints we can place on the embedded stellar cluster environment the early Sun may be have been born in, where the location and distribution of Sedna-like orbits sculpted by multiple stellar encounters is indicative of the birth cluster size. We also report our observed latitude distribution and implications for the size of the plutino population.

  1. Observational Bias and the Clustering of Distant Eccentric Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Brown, Michael E.

    2017-08-01

    The hypothesis that a massive Planet Nine exists in the outer solar system on a distant eccentric orbit was inspired by observations showing that the objects with the most distant eccentric orbits in the Kuiper Belt have orbits that are physically aligned, that is, they are clustered in longitude of perihelion and have similar orbital planes. Questions have remained, however, about the effects of observational bias on these observations, particularly on the longitudes of perihelion. Specifically, distant eccentric Kuiper Belt objects (KBOs) tend to be faint and only observable near their perihelia, suggesting that the longitudes of perihelion of the known distant objects could be strongly biased by the limited number of locations in the sky where deep surveys have been carried out. We have developed a method to rigorously estimate the bias in longitude of perihelion for Kuiper Belt observations. We find that the probability that the 10 known KBOs with semimajor axis beyond 230 au are drawn from a population with uniform longitude of perihelion is 1.2%. Combined with the observation that the orbital poles of these objects are also clustered, the overall probability of detecting these two independent clusterings in a randomly distributed sample is 0.025%. While observational bias is clearly present in these observations, it is unlikely to explain the observed alignment of the distant eccentric KBOs.

  2. Studies of extra-solar Oort Clouds and the Kuiper Disk

    NASA Technical Reports Server (NTRS)

    Stern, S. Alan

    1994-01-01

    The March 1994 Semi-Annual report for Studies of Extra-Solar Oort Clouds and the Kuiper Disk is presented. We are conducting research designed to enhance our understanding of the evolution and detectability of comet clouds and disks. This area holds promise for also improving our understanding of outer solar system formation, the bombardment history of the planets, the transport of volatiles and organics from the outer solar system to the inner planets, and to the ultimate fate of comet clouds around the Sun and other stars. According to 'standard' theory, both the Kuiper Disk and Oort Cloud are (at least in part) natural products of the planetary accumulation stage of solar system formation. One expects such assemblages to be a common attribute of other solar systems. Therefore, searches for comet disks and clouds orbiting other stars offer a new method for inferring the presence of planetary systems. Our three-year effort consists of two major efforts: observational work to predict and search for the signatures of Oort Clouds and comet disks around other stars; and modeling studies of the formation and evolution of the Kuiper Disk (KD) and similar assemblages that may reside around other stars, including beta Pic.

  3. The Phase Space Structure Near Neptune Resonances in the Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Malhotra, Renu

    1996-01-01

    The Solar system beyond Neptune is believed to house a population of small primordial bodies left over from the planet formation process. The region up to heliocentric distance ˜50 AU (a.k.a. the Kuiper Belt) may be the source of the observed short-period comets. In this region, the phase space structure near orbital resonances with Neptune is of special interest for the long-term stability of orbits. There is reason to believe that a significant fraction (perhaps most) of the Kuiper Belt objects reside preferentially in these resonance locations. This paper describes the dynamics of small objects near the major orbital resonances with Neptune. Estimates of the widths of stable resonance zones as well as the properties of resonant orbits are obtained from the circular, planar restricted three-body model. Although this model does not contain the full complexity of the long-term orbital dynamics of Kuiper Belt objects subject to the full N-body perturbations of all the planets, it does provide a baseline for the phase space structure and properties of resonant orbits in the trans-Neptunian Solar system.

  4. Automatic Detection of Sub-Kilometer Craters in High Resolution Images of Mars

    NASA Astrophysics Data System (ADS)

    Urbach, E. R.; Stepinski, T. F.

    2008-03-01

    A method for automatic detection of impact craters in high resolution images of Mars is presented. This new method enables detection of sub-kilometer craters that are too small to be cataloged by previous methods and too numerous for manual detection.

  5. 47 CFR 73.186 - Establishment of effective field at one kilometer.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Establishment of effective field at one... RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.186 Establishment of effective field at one kilometer. (a) Section 73.189 provides that certain minimum field strengths are acceptable...

  6. 47 CFR 73.186 - Establishment of effective field at one kilometer.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Establishment of effective field at one... RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.186 Establishment of effective field at one kilometer. (a) Section 73.189 provides that certain minimum field strengths are acceptable...

  7. 47 CFR 73.186 - Establishment of effective field at one kilometer.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Establishment of effective field at one... RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.186 Establishment of effective field at one kilometer. (a) Section 73.189 provides that certain minimum field strengths are acceptable...

  8. 47 CFR 73.186 - Establishment of effective field at one kilometer.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Establishment of effective field at one... RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.186 Establishment of effective field at one kilometer. (a) Section 73.189 provides that certain minimum field strengths are acceptable...

  9. 2007 TY430: A COLD CLASSICAL KUIPER BELT TYPE BINARY IN THE PLUTINO POPULATION

    SciTech Connect

    Sheppard, Scott S.; Ragozzine, Darin; Trujillo, Chadwick

    2012-03-15

    Kuiper Belt object 2007 TY430 is the first wide, equal-sized, binary known in the 3:2 mean motion resonance with Neptune. The two components have a maximum separation of about 1 arcsec and are on average less than 0.1 mag different in apparent magnitude with identical ultra-red colors (g - i = 1.49 {+-} 0.01 mag). Using nearly monthly observations of 2007 TY430 from 2007 to 2011, the orbit of the mutual components was found to have a period of 961.2 {+-} 4.6 days with a semi-major axis of 21000 {+-} 160 km and eccentricity of 0.1529 {+-} 0.0028. The inclination with respect to the ecliptic is 15.68 {+-} 0.22 deg and extensive observations have allowed the mirror orbit to be eliminated as a possibility. The total mass for the binary system was found to be 7.90 {+-} 0.21 Multiplication-Sign 10{sup 17} kg. Equal-sized, wide binaries and ultra-red colors are common in the low-inclination 'cold' classical part of the Kuiper Belt and likely formed through some sort of three-body interactions within a much denser Kuiper Belt. To date 2007 TY430 is the only ultra-red, equal-sized binary known outside of the classical Kuiper Belt population. Numerical simulations suggest 2007 TY430 is moderately unstable in the outer part of the 3:2 resonance and thus 2007 TY430 is likely an escaped 'cold' classical object that later got trapped in the 3:2 resonance. Similar to the known equal-sized, wide binaries in the cold classical population, the binary 2007 TY430 requires a high albedo and very low density structure to obtain the total mass found for the pair. For a realistic minimum density of 0.5 g cm{sup -3} the albedo of 2007 TY430 would be greater than 0.17. For reasonable densities, the radii of either component should be less than 60 km, and thus the relatively low eccentricity of the binary is interesting since no tides should be operating on the bodies at their large distances from each other. The low prograde inclination of the binary also makes it unlikely that the Kozai

  10. Pharmacokinetics and adverse effects of 20-mg/kg/day trimethoprim and 100-mg/kg/day sulfamethoxazole in healthy adult subjects.

    PubMed

    Stevens, R C; Laizure, S C; Williams, C L; Stein, D S

    1991-09-01

    The pharmacokinetics of trimethoprim-sulfamethoxazole were studied in 12 healthy adult subjects receiving trimethoprim at 20 mg/kg of body weight per day and sulfamethoxazole at 100 mg/kg/day, which is the conventional dose for treating Pneumocystis carinii pneumonia (PCP). Daily doses were evenly divided and orally administered every 6 h for 3 days. Trimethoprim, sulfamethoxazole, and N4-acetylsulfamethoxazole concentrations in serum and urine were measured by high-performance liquid chromatography. Five subjects withdrew from the study because of intolerable gastrointestinal and central nervous system toxicities. In the seven subjects that completed the study, the mean maximum serum drug concentrations after the last dose were 13.6 +/- 2.0, 372 +/- 64, and 50.1 +/- 10.9 micrograms/ml for trimethoprim, sulfamethoxazole, and N4-acetylsulfamethoxazole, respectively. The mean half-lives were 13.6 +/- 3.5, 14.0 +/- 2.3, and 18.6 +/- 4.3 h, respectively. Changes in absolute neutrophil count were significantly correlated with the minimum concentrations of trimethoprim and sulfamethoxazole in serum and trimethoprim area under the concentration-time curve (for all three parameters, r2 = 0.6 and P less than 0.05). Our findings add to the evidence that serum drug concentrations in adults following the conventional dose of trimethoprim-sulfamethoxazole for PCP are excessive and contribute to certain adverse reactions. Further studies are indicated in patients to optimize the dosing regimen of trimethoprim-sulfamethoxazole in the treatment of PCP.

  11. Pharmacokinetics and adverse effects of 20-mg/kg/day trimethoprim and 100-mg/kg/day sulfamethoxazole in healthy adult subjects.

    PubMed Central

    Stevens, R C; Laizure, S C; Williams, C L; Stein, D S

    1991-01-01

    The pharmacokinetics of trimethoprim-sulfamethoxazole were studied in 12 healthy adult subjects receiving trimethoprim at 20 mg/kg of body weight per day and sulfamethoxazole at 100 mg/kg/day, which is the conventional dose for treating Pneumocystis carinii pneumonia (PCP). Daily doses were evenly divided and orally administered every 6 h for 3 days. Trimethoprim, sulfamethoxazole, and N4-acetylsulfamethoxazole concentrations in serum and urine were measured by high-performance liquid chromatography. Five subjects withdrew from the study because of intolerable gastrointestinal and central nervous system toxicities. In the seven subjects that completed the study, the mean maximum serum drug concentrations after the last dose were 13.6 +/- 2.0, 372 +/- 64, and 50.1 +/- 10.9 micrograms/ml for trimethoprim, sulfamethoxazole, and N4-acetylsulfamethoxazole, respectively. The mean half-lives were 13.6 +/- 3.5, 14.0 +/- 2.3, and 18.6 +/- 4.3 h, respectively. Changes in absolute neutrophil count were significantly correlated with the minimum concentrations of trimethoprim and sulfamethoxazole in serum and trimethoprim area under the concentration-time curve (for all three parameters, r2 = 0.6 and P less than 0.05). Our findings add to the evidence that serum drug concentrations in adults following the conventional dose of trimethoprim-sulfamethoxazole for PCP are excessive and contribute to certain adverse reactions. Further studies are indicated in patients to optimize the dosing regimen of trimethoprim-sulfamethoxazole in the treatment of PCP. PMID:1952863

  12. Excitation Energy Deposition and the Fission Process in the Reactions COPPER-63 + MOLYBDENUM-92, 100 AT 10, 17, 25 and 35 Amev and NEON-20 + SAMARIUM-144, 148, 154 AT 20 Amev.

    NASA Astrophysics Data System (ADS)

    Lou, Yunian

    Excitation energy deposition and light particle emission for fissioning nuclei with excitation energies from 2 to 6 MeV/nucleon are studied for the reaction of 20 AMeV ^{20}Ne with ^{144,148,154}Sm and 10, 17, 25 and 35 AMeV ^{63}Cu with ^{92,100}Mo using the Texas A&M Neutron Ball detector. Linear momentum transfers (LMT) are determined from fission fragment folding angle measurements and used to estimate excitation energies. The associated multiplicities of neutrons, protons and alpha particles are obtained, together with their average energies. These data are used to reconstruct the initial excitation energies of the compound nucleus. With increasing beam energy, an increasing discrepancy between the excitation energy derived from the LMT measurements and the reconstructed one is observed attributed to intermediate mass fragment (IMF) emission. The measured neutron multiplicities show a strong increase with increasing neutron to proton ratio of composite system, as well as increasing beam energy. The experimental data for particle multiplicities are compared with calculations using the statistical model GEMINI. The effect of the dynamic fission delay on the light particle multiplicities is explored. The neutron multiplicities are relatively insensitive to the dynamic fission delay. The calculated charged particle multiplicities are more sensitive, but the comparisons between the calculation and experiment indicate that the light charged particle multiplicity data are not a good measure of dynamic fission delay.

  13. A SEARCH FOR OCCULTATIONS OF BRIGHT STARS BY SMALL KUIPER BELT OBJECTS USING MEGACAM ON THE MMT

    SciTech Connect

    Bianco, F. B.; Lehner, M. J.; Protopapas, P.; McLeod, B. A.; Alcock, C. R.; Holman, M. J.

    2009-08-15

    We conducted a search for occultations of bright stars by Kuiper Belt Objects (KBOs) to estimate the density of subkilometer KBOs in the sky. We report here the first results of this occultation survey of the outer solar system conducted in 2007 June and 2008 June/July at the MMT Observatory using Megacam, the large MMT optical imager. We used Megacam in a novel shutterless continuous-readout mode to achieve high-precision photometry at 200 Hz, which with point-spread function convolution results in an effective sampling of {approx}30 Hz. We present an analysis of 220 star hours of data at a signal-to-noise ratio of 25 or greater, taken from images of fields within 3 deg. of the ecliptic plane. The survey efficiency is greater than 10% for occultations by KBOs of diameter d {>=} 0.7 km, and we report no detections in our data set. We set a new 95% confidence level upper limit for the surface density {sigma} {sub N}(d) of KBOs larger than 1 km: {sigma} {sub N}(d {>=} 1 km) {<=} 2.0 x 10{sup 8} deg{sup -2}, and for KBOs larger than 0.7 km {sigma} {sub N}(d {>=} 0.7 km) {<=} 4.8 x 10{sup 8} deg{sup -2}.

  14. 20 CFR 663.100 - What is the role of the adult and dislocated worker programs in the One-Stop delivery system?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... worker programs in the One-Stop delivery system? 663.100 Section 663.100 Employees' Benefits EMPLOYMENT... OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the One-Stop Delivery System § 663.100 What is the role of the adult and dislocated worker programs in the...

  15. Energy Drinks Improve Five-Kilometer Running Performance in Recreational Endurance Runners.

    PubMed

    Prins, Philip J; Goss, Fredric L; Nagle, Elizabeth F; Beals, Kim; Robertson, Robert J; Lovalekar, Mita T; Welton, Gary L

    2016-11-01

    Prins, PJ, Goss, FL, Nagle, EF, Beals, K, Robertson, RJ, Lovalekar, MT, and Welton, GL. Energy drinks improve five-kilometer running performance in recreational endurance runners. J Strength Cond Res 30(11): 2979-2990, 2016-The purpose of this study was to evaluate exercise performance time and related physiological and perceptual responses of recreational endurance runners after they had ingested a commercially available energy drink (Red Bull, Red Bull GmbH, Fuschl am See, Austria) containing caffeine, glucose, and taurine. Recreational endurance runners (n = 18; 13 men and 5 women; age: 20.39 ± 3.27 years; weight: 71.25 ± 17.17 kg; height: 178.00 ± 7.57 cm; V[Combining Dot Above]O2max: 55.94 ± 7.66 ml·kg·min) participated in a double-blind, crossover, repeated-measures study where they were randomized to supplement with 500 ml of the commercially available energy drink Red Bull and a noncaffeinated, sugar-free placebo (PLA) 60 minutes before completing a 5-km time trial on a treadmill, separated by 7 days. Heart rate, rating of perceived exertion (RPE) (RPE-Overall; RPE-Chest; RPE-Legs), and affect were recorded at rest, 1 hour before ingestion, at 5-minute intervals during the 5-km time trial, and immediately after exercise. Session RPE and session affect were obtained 5 minutes after completion of the 5-km time trial. The distance covered at each 5-minute interval during the 5-km time trial was recorded. Performance improved with the energy drink compared with placebo (Red Bull: 1,413.2 ± 169.7 vs. PLA: 1,443.6 ± 179.2 seconds; p = 0.016), but there were no differences in RPE, affect, session RPE, session affect, or the distance covered at 5-minute splits between the two 5-km time trials (p > 0.05). These results demonstrate that consuming a commercially available energy drink before exercise can improve 5-km performance. These results may have application for altering pre-exercise nutritional strategies in recreational runners.

  16. Detection of sub-kilometer craters in high resolution planetary images using shape and texture features

    NASA Astrophysics Data System (ADS)

    Bandeira, Lourenço; Ding, Wei; Stepinski, Tomasz F.

    2012-01-01

    Counting craters is a paramount tool of planetary analysis because it provides relative dating of planetary surfaces. Dating surfaces with high spatial resolution requires counting a very large number of small, sub-kilometer size craters. Exhaustive manual surveys of such craters over extensive regions are impractical, sparking interest in designing crater detection algorithms (CDAs). As a part of our effort to design a CDA, which is robust and practical for planetary research analysis, we propose a crater detection approach that utilizes both shape and texture features to identify efficiently sub-kilometer craters in high resolution panchromatic images. First, a mathematical morphology-based shape analysis is used to identify regions in an image that may contain craters; only those regions - crater candidates - are the subject of further processing. Second, image texture features in combination with the boosting ensemble supervised learning algorithm are used to accurately classify previously identified candidates into craters and non-craters. The design of the proposed CDA is described and its performance is evaluated using a high resolution image of Mars for which sub-kilometer craters have been manually identified. The overall detection rate of the proposed CDA is 81%, the branching factor is 0.14, and the overall quality factor is 72%. This performance is a significant improvement over the previous CDA based exclusively on the shape features. The combination of performance level and computational efficiency offered by this CDA makes it attractive for practical application.

  17. Dynamics of the Trans-Neptune Region: Apsidal Waves in the Kuiper Belt

    NASA Technical Reports Server (NTRS)

    Ward, William R.; Hahn, Joseph M.

    1998-01-01

    The role of apsidal density waves propagating in a primordial trans-Neptune disk (i.e., Kuiper belt) is investigated. It is shown that Neptune launches apsidal waves at its secular resonance near 40 AU that propagate radially outward, deeper into the particle disk. The wavelength of apsidal waves is considerably longer than waves that might be launched at Lindblad resonances, because the pattern speed, g(sub s), resulting from the apsis precession of Neptune is much slower than its mean motion, Omega(sub s). If the early Kuiper belt had a sufficient surface density, sigma, the disk's wave response to Neptune's secular perturbation would have spread the disturbing torque radially over a collective scale lambda(sub *) approx. = r(2(mu)(sub d)Omega/ absolute value of r dg/dr)(sup 1/2), where mu(sub d)equivalent pi(sigma)r(exp 2)/(1 solar mass) and Omega(r) and g(r) are respectively the mean motion and precession frequency of the disk particles. This results in considerably smaller eccentricities at resonance than had the disk particles been treated as noninteracting test particles. Consequently, particles are less apt to be excited into planet-crossing orbits, implying that the erosion timescales reported by earlier test-particle simulations of the Kuiper belt may be underestimated. It is also shown that the torque the disk exerts upon the planet (due to its gravitational attraction for the disk's spiral wave pattern) damps the planet's eccentricity and further inhibits the planet's ability to erode the disk. Key words: celestial mechanics, stellar dynamics - comets: general minor planets, asteroids

  18. A Kuiper Belt Pair? Artist's Concept of 2014 MU69 as a Binary Object

    NASA Image and Video Library

    2017-08-03

    This is one artist's concept of Kuiper Belt object 2014 MU69, the next flyby target for NASA's New Horizons mission. This binary concept is based on telescope observations made at Patagonia, Argentina, on July 17, 2017, when MU69 passed in front of a star. New Horizons scientists theorize that it could be a single body with a large chunk taken out of it, or two bodies that are close together or even touching. https://photojournal.jpl.nasa.gov/catalog/PIA21867

  19. Water Ice in 2060 Chiron and Its Implications for Centaurs and Kuiper Belt Objects.

    PubMed

    Luu; Jewitt; Trujillo

    2000-03-10

    We report the detection of water ice in the Centaur 2060 Chiron, based on near-infrared spectra (1.0-2.5 µm) taken with the 3.8 m United Kingdom Infrared Telescope and the 10 m Keck Telescope. The appearance of this ice is correlated with the recent decline in Chiron's cometary activity: the decrease in the coma cross section allows previously hidden solid-state surface features to be seen. We predict that water ice is ubiquitous among Centaurs and Kuiper Belt objects, but its surface coverage varies from object to object and thus determines its detectability and the occurrence of cometary activity.

  20. The evolution of comets in the Oort cloud and Kuiper belt.

    PubMed

    Alan Stern, S

    2003-08-07

    Comets are remnants from the time when the outer planets formed, approximately 4-4.5 billion years ago. They have been in storage since then in the Oort cloud and Kuiper belt-distant regions that are so cold and sparsely populated that it was long thought that comets approaching the Sun were pristine samples from the time of Solar System formation. It is now recognized, however, that a variety of subtle but important evolutionary mechanisms operate on comets during their long storage, so they can no longer be regarded as wholly pristine.

  1. NASA’s Kuiper Airborne Observatory 1974-1995 - Twenty One Years of Discovery

    NASA Astrophysics Data System (ADS)

    Erickson, Edwin F.

    2017-01-01

    The Gerard P. Kuiper Airborne Observatory (KAO) forged a unique record in the annals of astronomy. Teams of scientists developed and flew with their specialized, state-of-the-art instruments to make observations not possible from the ground, at wavelengths from 0.3 µm to 1.6 mm. The talk will describe the KAO and its legacy of scientific findings, infrared instrumentation technology, experience for young astronomers and their impact on the field of infrared astronomy - and the rationale for SOFIA.

  2. Consumption of gluten-free products: should the threshold value for trace amounts of gluten be at 20, 100 or 200 p.p.m.?

    PubMed

    Gibert, Anna; Espadaler, Montserrat; Angel Canela, Miguel; Sánchez, Anna; Vaqué, Cristina; Rafecas, Magda

    2006-11-01

    The threshold of gluten contamination in gluten-free products of both dietary and normal consumption is under debate. The objective of this study was to gather information on consumption of gluten-free products intended for dietary use of people under a gluten-free diet. This information is essential to ascertain the exposure of coeliac patients to gluten through their diet and deduce the maximum gluten content that these products should contain to guarantee a safe diet. A diet diary of consumption of gluten-free products intended for dietary use was distributed to the coeliac societies of two typical Mediterranean countries (Italy and Spain) and two Northern countries (Norway and Germany). The diet diary included a self-weigh table of the selected food items and a 10-day consumption table. Results were reported in percentiles as distributions were clearly right skewed. The respondents included in the study accounted for 1359 in Italy, 273 in Spain, 226 in Norway and 56 in Germany. Gluten-free products intended for dietary use contributed significantly to the diet of coeliac patients in Italy, Germany and Norway and to a lesser degree in Spain. The most consumed gluten-free product in all countries was bread, and it was double consumed in the Northern countries (P<0.001). Mediterranean countries showed consumption of a wider variety of gluten-free foods and pasta was eaten to a large degree in Italy. The differences between Northern and Mediterranean countries were not in the total amount of gluten-free products but in the type of products consumed. The observed daily consumption of gluten-free products results in the exposure to rather large amounts of gluten, thus the limit of 200 p.p.m. should be revised. A limit of 20 p.p.m. for products naturally gluten-free and of 100 p.p.m. for products rendered gluten-free is proposed to guarantee a safe diet and to enable coeliac patients to make an informed choice. These limits should be revised as new data become

  3. A FEATURE MOVIE OF SiO EMISSION 20-100 AU FROM THE MASSIVE YOUNG STELLAR OBJECT ORION SOURCE I

    SciTech Connect

    Matthews, L. D.; Greenhill, L. J.; Goddi, C.; Humphreys, E. M. L.; Chandler, C. J.; Kunz, M. W.

    2010-01-01

    We present multi-epoch Very Long Baseline Array imaging of the {sup 28}SiO v = 1 and v = 2, J = 1-0 maser emission toward the massive young stellar object (YSO) Orion Source I. Both SiO transitions were observed simultaneously with an angular resolution of approx0.5 mas (approx0.2 AU for d = 414 pc) and a spectral resolution of approx0.2 km s{sup -1}. Here we explore the global properties and kinematics of the emission through two 19-epoch animated movies spanning 21 months (from 2001 March 19 to 2002 December 10). These movies provide the most detailed view to date of the dynamics and temporal evolution of molecular material within approx20-100 AU of a massive (approx>8 M{sub sun}) YSO. As in previous studies, we find that the bulk of the SiO masers surrounding Source I lie in an X-shaped locus; the emission in the south and east arms is predominantly blueshifted, and emission in the north and west is predominantly redshifted. In addition, bridges of intermediate-velocity emission are observed connecting the red and blue sides of the emission distribution. We have measured proper motions of over 1000 individual maser features and found that these motions are characterized by a combination of radially outward migrations along the four main maser-emitting arms and motions tangent to the intermediate-velocity bridges. We interpret the SiO masers as arising from a wide-angle bipolar wind emanating from a rotating, edge-on disk. The detection of maser features along extended, curved filaments suggests that magnetic fields may play a role in launching and/or shaping the wind. Our observations appear to support a picture in which stars with masses as high as at least 8 M{sub sun} form via disk-mediated accretion. However, we cannot yet rule out that the Source I disk may have been formed or altered following a recent close encounter.

  4. Crustal Layer of Seismic Velocity 6.9 to 7.6 Kilometers per Second under the Deep Oceans.

    PubMed

    Maynard, G L

    1970-04-03

    Refraction measurements made in the deep ocean between the Marshall and Hawaiian islands reveal a layer of seismic velocity 7.3 kilometers per second between the 6.8 kilometer per second oceanic crustal layer and the mantle. This layer, normally masked as a second arrival, is revealed by continuous air gun refraction data. The layer may be widespread in the deep oceans.

  5. Constraints on impact rates in the pluto-charon system and the population of the Kuiper comet belt

    SciTech Connect

    Weissman, P.R. ); Dobrovolskis, A.R. ); Stern, S.A. )

    1989-11-01

    Impact rates in the Pluto-Charon system are dominated by comets from the proposed Kuiper Belt, 30 to 50 AU from the Sun. Such collisions excite the eccentricity of Charon's orbit, which then decays due to tidal dissipation. Charon's eccentricity approaches a quasi-steady state, which can be used to constrain the total number and mass of comets in the Kuiper Belt. Unfortunately, the current upper limit on Charon's orbital eccentricity must be reduced by more than a factor of ten before useful constraints can be set.

  6. Constraints on impact rates in the Pluto-Charon system and the population of the Kuiper comet belt

    NASA Technical Reports Server (NTRS)

    Weissman, Paul R.; Dobrovolskis, Anthony R.; Stern, S. Alan

    1989-01-01

    Impact rates in the Pluto-Charon system are dominated by comets from the proposed Kuiper Belt, 30 to 50 AU from the sun. Such collisions excite the eccentricity of Charon's orbit, which then decays due to tidal dissipation. Charon's eccentricity approaches a quasi-steady state, which can be used to constrain the total number and mass of comets in the Kuiper Belt. Unfortunately, the current upper limit on Charon's orbital eccentricity must be reduced by more than a factor of ten before useful constraints can be set.

  7. Airborne spectrophotometry of P/Halley from 20 to 65 microns

    NASA Technical Reports Server (NTRS)

    Glaccum, W.; Moseley, S. H.; Campins, H.; Loewenstein, R. F.

    1986-01-01

    Simultaneous 20 to 65 microns spectrometry and 100 microns photometry of P/Halley obtained on board the Kuiper Airborne Observatory (KAO) in 1985 Dec. and 1986 April are discussed. Spectra with resolution 30 to 50 were obtained with the NASA/Goddard 24 channel grating spectrometer. Measurements were made on the nucleus as well as 5 points along and perpendicular to the Sun-tail direction. The observations reveal the absence of any strong spectral features. The color temperature of the dust varies over time scales as short as 2 days, but is higher than that expected for a rapidly rotating blackbody at the same distance from the Sun. The color temperature does not vary within 1 arcmin of the nucleus, but the coma is brighter on the sunward side than on the antisunward side.

  8. Impact Craters on Pluto and Charon Indicate a Deficit of Small Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Singer, Kelsi N.; McKinnon, William B.; Greenstreet, Sarah; Gladman, Brett; Parker, Alex Harrison; Robbins, Stuart J.; Schenk, Paul M.; Stern, S. Alan; Bray, Veronica; Spencer, John R.; Weaver, Harold A.; Beyer, Ross A.; Young, Leslie; Moore, Jeffrey M.; Olkin, Catherine B.; Ennico, Kimberly; Binzel, Richard; Grundy, William M.; New Horizons Geology Geophysics and Imaging Science Theme Team, The New Horizons MVIC and LORRI Teams

    2016-10-01

    The impact craters observed during the New Horizons flyby of the Pluto system currently provide the most extensive empirical constraints on the size-frequency distribution of smaller impactors in the Kuiper belt. These craters also help us understand the surface ages and geologic evolution of the Pluto system bodies. Pluto's terrains display a diversity of crater retention ages and terrain types, indicating ongoing geologic activity and a variety of resurfacing styles including both exogenic and endogenic processes. Charon's informally named Vulcan Planum did experience early resurfacing, but crater densities suggest this is also a relatively ancient surface. We will present and compare the craters mapped across all of the relevant New Horizons LOng Range Reconnaissance Imager (LORRI) and Multispectral Visible Imaging Camera (MVIC) datasets of Pluto and Charon. We observe a paucity of small craters on all terrains (there is a break to a shallower slope for craters below 10 km in diameter), despite adequate resolution to observe them. This lack of small craters cannot be explained by geological resurfacing alone. In particular, the main area of Charon's Vulcan Planum displays no obviously embayed or breached crater rims, and may be the best representation of a production population since the emplacement of the plain. The craters on Pluto and Charon are more consistent with Kuiper belt and solar system evolution models producing fewer small objects.This work was supported by NASA's New Horizons project.

  9. 1998 SM165: A large Kuiper belt object with an irregular shape

    PubMed Central

    Romanishin, W.; Tegler, S. C.; Rettig, T. W.; Consolmagno, G.; Botthof, B.

    2001-01-01

    The recent discovery of an ancient reservoir of icy bodies at and beyond the orbit of Neptune—the Kuiper belt—has opened a new frontier in astronomy. Measurements of the physical and chemical nature of Kuiper belt objects (KBOs) can constrain our ideas of the processes of planet formation and evolution. Our 1.8-m Vatican Advanced Technology Telescope and charge-coupled device camera observations of the KBO 1998 SM165 indicate its brightness periodically varies by 0.56 magnitudes over a 4-h interval. If we assume a uniform albedo of 0.04, which is typical of values found in the literature for a handful of KBOs, and an “equator-on” aspect, we find 1998 SM165 has axes of length 600 × 360 km. If our assumptions are correct, such dimensions put 1998 SM165 among the largest elongated objects known in our solar system. Perhaps long ago, two nearly spherical KBOs of comparable size coalesced to form a compound object, or perhaps 1998 SM165 is the residual core of a catastrophic fragmentation of a larger precursor. PMID:11572937

  10. 1998 SM165: a large Kuiper belt object with an irregular shape.

    PubMed

    Romanishin, W; Tegler, S C; Rettig, T W; Consolmagno, G; Botthof, B

    2001-10-09

    The recent discovery of an ancient reservoir of icy bodies at and beyond the orbit of Neptune-the Kuiper belt-has opened a new frontier in astronomy. Measurements of the physical and chemical nature of Kuiper belt objects (KBOs) can constrain our ideas of the processes of planet formation and evolution. Our 1.8-m Vatican Advanced Technology Telescope and charge-coupled device camera observations of the KBO 1998 SM(165) indicate its brightness periodically varies by 0.56 magnitudes over a 4-h interval. If we assume a uniform albedo of 0.04, which is typical of values found in the literature for a handful of KBOs, and an "equator-on" aspect, we find 1998 SM(165) has axes of length 600 x 360 km. If our assumptions are correct, such dimensions put 1998 SM(165) among the largest elongated objects known in our solar system. Perhaps long ago, two nearly spherical KBOs of comparable size coalesced to form a compound object, or perhaps 1998 SM(165) is the residual core of a catastrophic fragmentation of a larger precursor.

  11. Size and albedo of Kuiper belt object 55636 from a stellar occultation.

    PubMed

    Elliot, J L; Person, M J; Zuluaga, C A; Bosh, A S; Adams, E R; Brothers, T C; Gulbis, A A S; Levine, S E; Lockhart, M; Zangari, A M; Babcock, B A; Dupré, K; Pasachoff, J M; Souza, S P; Rosing, W; Secrest, N; Bright, L; Dunham, E W; Sheppard, S S; Kakkala, M; Tilleman, T; Berger, B; Briggs, J W; Jacobson, G; Valleli, P; Volz, B; Rapoport, S; Hart, R; Brucker, M; Michel, R; Mattingly, A; Zambrano-Marin, L; Meyer, A W; Wolf, J; Ryan, E V; Ryan, W H; Morzinski, K; Grigsby, B; Brimacombe, J; Ragozzine, D; Montano, H G; Gilmore, A

    2010-06-17

    The Kuiper belt is a collection of small bodies (Kuiper belt objects, KBOs) that lie beyond the orbit of Neptune and which are believed to have formed contemporaneously with the planets. Their small size and great distance make them difficult to study. KBO 55636 (2002 TX(300)) is a member of the water-ice-rich Haumea KBO collisional family. The Haumea family are among the most highly reflective objects in the Solar System. Dynamical calculations indicate that the collision that created KBO 55636 occurred at least 1 Gyr ago. Here we report observations of a multi-chord stellar occultation by KBO 55636, which occurred on 9 October 2009 ut. We find that it has a mean radius of 143 +/- 5 km (assuming a circular solution). Allowing for possible elliptical shapes, we find a geometric albedo of in the V photometric band, which establishes that KBO 55636 is smaller than previously thought and that, like its parent body, it is highly reflective. The dynamical age implies either that KBO 55636 has an active resurfacing mechanism, or that fresh water-ice in the outer Solar System can persist for gigayear timescales.

  12. Using Near Infrared Observations and Models to Analyze Surface Compositions of Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    McGuire, Ryan

    Kuiper Belt Objects (KBOs) are primordial icy objects in the outer solar system. Compositional information for KBOs helps us understand the original environment of the solar system as well as identify objects that are compositionally anomalous. Due to the faint nature of KBOs, very few spectroscopic observations have been made of them. Instead, photometric observations at infrared wavelengths are made to partially construct their spectra. I calculate near infrared reflectances for 12 objects using photometric observations from the Gemini North telescope. I combine these near infrared reflectances with data from the Spitzer Space Telescope. This combination of Gemini and Spitzer photometry along with compositional model analysis allows us to find the surface composition (organics, H2O, CO2, CH4, and other hydrated silicates) for these 12 objects. I found that my objects fit into one of four taxonomic classes found in the Kuiper Belt. We have found using the color analysis, that Haumea has water on its surface and Eris is most likely to have methane on its surface. By analyzing this data we measure the compositional mixing in the outer solar system.

  13. Searching for Kuiper Belt Object Flyby Targets for the New Horizons Spacecraft.

    NASA Astrophysics Data System (ADS)

    Kavelaars, J. J.; Spencer, J. R.; Benecchi, S. D.; Binzel, R. P.; Borncamp, D.; Buie, M. W.; DeMeo, F. E.; Fabbro, S.; Fuentes, C. I.; Gay, P. L.; Gwyn, S. D. J.; Holman, M. J.; McLeod, B. A.; Osip, D. J.; Parker, A. H.; Sheppard, S. S.; Stern, S. A.; Tholen, D. J.; Trilling, D. E.; Ragozzine, D. A.; Wasserman, L. H.; Hunters, Ice

    2012-10-01

    The New Horizons spacecraft will fly past Pluto in July 2015 and then continue deeper into the Kuiper Belt, providing an opportunity to encounter one or more small ( 50 km) KBOs. This first flyby of a typical KBO would revolutionize our understanding of these bodies, providing information that can be extrapolated to hundreds of thousands of similar objects in the Kuiper Belt. Statistically, we expect several KBOs with ground based V magnitude less than 26.0 to be accessible with the delta-V available onboard New Horizons. At this point, however, no known KBOs are reachable by the spacecraft. We have therefore begun a dedicated search for suitable targets, using the Subaru, Magellan, and CFHT telescopes. The search is complicated by the fact that targetable objects are currently in the Milky Way, so search depth is limited by confusion with background stars unless seeing is exceptional. As of mid-2012, we have discovered 24 KBOs near the spacecraft trajectory, none of which are accessible to the spacecraft. Several of the targets could be reached with less than twice the available delta-V, and much of the accessible volume has not yet been searched to sufficient depth. Several objects already discovered will be observable at long range from New Horizons, providing opportunities for (for example) searches for binarity with much higher spatial resolution than is possible from Earth. The search has already yielded the second known trailing Neptune Trojan (Parker et al., this conference).

  14. Long-Term Dynamics and the Orbital Inclinations of the Classical Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Kuchner, Marc J.; Brown, Michael E.; Holman, Matthew

    2002-08-01

    We numerically integrated the orbits of 1458 particles in the region of the classical Kuiper belt (41 AU<=a<=47 AU) to explore the role of dynamical instabilities in sculpting the inclination distribution of the classical Kuiper belt objects (KBOs). We find that the selective removal of low-inclination objects by overlapping secular resonances (ν17 and ν18) acts to raise the mean inclination of the surviving population of particles over 4 billion yr of interactions with Jupiter, Saturn, Uranus, and Neptune, though these long-term dynamical effects do not themselves appear to explain the discovery of KBOs with inclinations near 30°. Our integrations also imply that after 3 billion yr of interaction with the massive planets, high-inclination KBOs more efficiently supply Neptune-encountering objects, the likely progenitors of short-period comets, Centaurs, and scattered KBOs. The secular resonances at low inclinations may indirectly cause this effect by weeding out objects unprotected by mean motion resonances during the first 3 billion yr.

  15. Origin of the peculiar eccentricity distribution of the inner cold Kuiper belt

    NASA Astrophysics Data System (ADS)

    Morbidelli, A.; Gaspar, H. S.; Nesvorny, D.

    2014-04-01

    Dawson and Murray-Clay (Dawson and Murray-Clay [2012]. Astrophys. J., 750, 43) pointed out that the inner part of the cold population in the Kuiper belt (that with semi major axis a<43.5 AU) has orbital eccentricities significantly smaller than the limit imposed by stability constraints. Here, we confirm their result by looking at the orbital distribution and stability properties in proper element space. We show that the observed distribution could have been produced by the slow sweeping of the 4/7 mean motion resonance with Neptune that accompanied the end of Neptune’s migration process. The orbital distribution of the hot Kuiper belt is not significantly affected in this process, for the reasons discussed in the main text. Therefore, the peculiar eccentricity distribution of the inner cold population cannot be unequivocally interpreted as evidence that the cold population formed in situ and was only moderately excited in eccentricity; it can simply be the signature of Neptune’s radial motion, starting from a moderately eccentric orbit. We discuss how this agrees with a scenario of giant planet evolution following a dynamical instability and, possibly, with the radial transport of the cold population.

  16. Evaluating the effect of internal aperture variability on transport in kilometer scale discrete fracture networks

    SciTech Connect

    Makedonska, Nataliia; Hyman, Jeffrey D.; Karra, Satish; Painter, Scott L.; Gable, Carl W.; Viswanathan, Hari S.

    2016-08-01

    The apertures of natural fractures in fractured rock are highly heterogeneous. However, in-fracture aperture variability is often neglected in flow and transport modeling and individual fractures are assumed to have uniform aperture distribution. The relative importance of in-fracture variability in flow and transport modeling within kilometer-scale fracture networks has been under debate for a long time, since the flow in each single fracture is controlled not only by in-fracture variability but also by boundary conditions. Computational limitations have previously prohibited researchers from investigating the relative importance of in-fracture variability in flow and transport modeling within large-scale fracture networks. We address this question by incorporating internal heterogeneity of individual fractures into flow simulations within kilometer scale three-dimensional fracture networks, where fracture intensity, P32 (ratio between total fracture area and domain volume) is between 0.027 and 0.031 [1/m]. The recently developed discrete fracture network (DFN) simulation capability, dfnWorks, is used to generate kilometer scale DFNs that include in-fracture aperture variability represented by a stationary log-normal stochastic field with various correlation lengths and variances. The Lagrangian transport parameters, non-reacting travel time, , and cumulative retention, , are calculated along particles streamlines. As a result, it is observed that due to local flow channeling early particle travel times are more sensitive to in-fracture aperture variability than the tails of travel time distributions, where no significant effect of the in-fracture aperture variations and spatial correlation length is observed.

  17. Evaluating the effect of internal aperture variability on transport in kilometer scale discrete fracture networks

    DOE PAGES

    Makedonska, Nataliia; Hyman, Jeffrey D.; Karra, Satish; ...

    2016-08-01

    The apertures of natural fractures in fractured rock are highly heterogeneous. However, in-fracture aperture variability is often neglected in flow and transport modeling and individual fractures are assumed to have uniform aperture distribution. The relative importance of in-fracture variability in flow and transport modeling within kilometer-scale fracture networks has been under debate for a long time, since the flow in each single fracture is controlled not only by in-fracture variability but also by boundary conditions. Computational limitations have previously prohibited researchers from investigating the relative importance of in-fracture variability in flow and transport modeling within large-scale fracture networks. We addressmore » this question by incorporating internal heterogeneity of individual fractures into flow simulations within kilometer scale three-dimensional fracture networks, where fracture intensity, P32 (ratio between total fracture area and domain volume) is between 0.027 and 0.031 [1/m]. The recently developed discrete fracture network (DFN) simulation capability, dfnWorks, is used to generate kilometer scale DFNs that include in-fracture aperture variability represented by a stationary log-normal stochastic field with various correlation lengths and variances. The Lagrangian transport parameters, non-reacting travel time, , and cumulative retention, , are calculated along particles streamlines. As a result, it is observed that due to local flow channeling early particle travel times are more sensitive to in-fracture aperture variability than the tails of travel time distributions, where no significant effect of the in-fracture aperture variations and spatial correlation length is observed.« less

  18. Effective matrix diffusion in kilometer-scale transport in fractured crystalline rock

    USGS Publications Warehouse

    Shapiro, A.M.

    2001-01-01

    Concentrations of tritium (3H) and dichlorodifluoromethane (CFC-12) in water samples taken from glacial drift and fractured crystalline rock over 4 km2 in central New Hampshire are interpreted to identify a conceptual model of matrix diffusion and the magnitude of the diffusion coefficient. Dispersion and mass transfer to and from fractures has affected the 3H concentration to the extent that the peak 3H concentration of the 1960s is no longer distinguishable. Because of heterogeneity in the bedrock the sparsely distributed chemical data do not warrant a three-dimensional transport model. Instead, a one-dimensional model of CFC-12 and 3H migration along flow lines in the glacial drift and bedrock is used to place bounds on the processes affecting kilometer-scale transport, and model parameters are varied to reproduce the measured relation between 3H and CFC-12, rather than their spatial distributions. A model of mass exchange to and from fractures that is dependent on the time-varying concentration gradient at fracture surfaces qualitatively reproduces the measured relation between 3H and CFC-12 with an upper bound for the fracture dispersivity approximately equal to 250 m and a lower bound for the effective matrix diffusion coefficient equal to 1 m2 yr-1. The diffusion coefficient at the kilometer scale is at least 3 orders of magnitude greater than laboratory estimates of diffusion in crystalline rock. The large diffusion coefficient indicates that diffusion into an immobile fluid phase (rock matrix) is masked at the kilometer scale by advective mass exchange between fractures with large contrasts in transmissivity. The measured transmissivity of fractures in the study area varies over more than 6 orders of magnitude. Advective mass exchange from high-permeability fractures to low-permeability fractures results in short migration distances of a chemical constituent in low-permeability fractures over an extended period of time before reentering high

  19. Effective matrix diffusion in kilometer-scale transport in fractured crystalline rock

    NASA Astrophysics Data System (ADS)

    Shapiro, Allen M.

    2001-03-01

    Concentrations of tritium (3H) and dichlorodifluoromethane (CFC-12) in water samples taken from glacial drift and fractured crystalline rock over 4 km2 in central New Hampshire are interpreted to identify a conceptual model of matrix diffusion and the magnitude of the diffusion coefficient. Dispersion and mass transfer to and from fractures has affected the 3H concentration to the extent that the peak 3H concentration of the 1960s is no longer distinguishable. Because of heterogeneity in the bedrock the sparsely distributed chemical data do not warrant a three-dimensional transport model. Instead, a one-dimensional model of CFC-12 and 3H migration along flow lines in the glacial drift and bedrock is used to place bounds on the processes affecting kilometer-scale transport, arid model parameters are varied to reproduce the measured relation between 3H and CFC-12, rather than their spatial distributions. A model of mass exchange to and from fractures that is dependent on the time-varying concentration gradient at fracture surfaces qualitatively reproduces the measured relation between 3H and CFC-12 with an upper bound for the fracture dispersivity approximately equal to 250 m and a lower bound for the effective matrix diffusion coefficient equal to 1 m2 yr-1. The diffusion coefficient at the kilometer scale is at least 3 orders of magnitude greater than laboratory estimates of diffusion in crystalline rock. The large diffusion coefficient indicates that diffusion into an immobile fluid phase (rock matrix) is masked at the kilometer scale by advective mass exchange between fractures with large contrasts in trarismissivity. The measured transmissivity of fractures in the study area varies over more than 6 orders of magnitude. Advective mass exchange from high-permeability fractures to low-permeability fractures results in short migration distances of a chemical constituent in low-permeability fractures over an extended period of time before reentering high

  20. Jupiter's decameter and kilometer emissions: Satellite effects and long term periodicities

    NASA Astrophysics Data System (ADS)

    St. Cyr, O. C.

    1985-12-01

    The results of observational studies of Jupiter's decameter (DAM) and kilometer (KOM) radio emissions are presented. The initial goal was to investigate the role of Jupiter's major satellites in modulating these sporadic emissions. The concepts of electromagnetic induction are reviewed in planet-sized bodies and then the Jovian magnetosphere environment and the physical characteristics of the Galilean satellites and Amalthea are described. Since the phase of Io is known to modulate the DAM emission, the problem of orbital resonance among the Galilean satellites is addressed. A secondary goal was to search for long term periodicities and other effects in the groundbased DAM data.

  1. Photographer : JPL Range : 6.5 million kilometers (4 million miles) Six violet images of Jupiter

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Photographer : JPL Range : 6.5 million kilometers (4 million miles) Six violet images of Jupiter makes the mosaic photo, showing the Great Red Spot as a swirling vortex type motion. This motion is also seen in several nearby white clouds. These bright white clouds and the Red Spot are rotating in a counter clockwise direction, except the peculiar filimentary cloud to the right of the Red Spot is going clockwise. The top of the picture shows the turbulence from the equatorial jet and more northerly atmospheric currents. The smallest clouds shown are only 70 miles (120 km) across.

  2. Spectral line interferometry with independent time standards at stations separated by 845 kilometers.

    PubMed

    Moran, J M; Crowther, P P; Burke, B F; Barrett, A H; Rogers, A E; Ball, J A; Carter, J C; Bare, C C

    1967-08-11

    An upper limit of 0.02 second of arc has been determined for a hydroxyl radical (OH) emission region associated with the radio source W3, with the use of a Michelson interferometer consisting of two radio telescopes 845 kilometers apart. Timing was provided at the stations by independent atomic frequency standards. The 1665-megahertz radiation was translated to video frequency and recorded digitally on magnetic tapes which were later processed by computer, yielding fringe phase and amplitude as a function of frequency over the received bandwidth.

  3. Log and lumber grades as indicators of wood quality in 20- to 100-year-old Douglas-fir trees from thinned and unthinned stands.

    Treesearch

    R. James Barbour; Dean L. Parry

    2001-01-01

    This report examines the differences in wood characteristics found in coastal Pacific Northwest Douglas-fir (Pseudotsuga mensziesii (Mirb.) Franco) trees harvested at the age of 70 to 100 years old to wood characteristics of trees harvested at the age of 40 to 60 years. Comparisons of differences in domestic log grades suggest that the proportion...

  4. Kuiper Crater

    NASA Image and Video Library

    1999-10-08

    NASA Mariner 10 took this picture some 2 1/2 hours before it passed Mercury on March 29, 1974. The bright-floored crater is the center of a very large bright area which could be seen in pictures from more than two million miles distant

  5. Extremely low noise UHF-band amplifiers for square kilometer array

    NASA Astrophysics Data System (ADS)

    Jiang, Nianhua; Garcia, Dominic; Niranjanan, Pat; Halman, Mark; Wevers, Ivan

    2016-07-01

    This paper demonstrates two designs of extremely low noise amplifiers in the low frequency range of 350 MHz to 1070 MHz. Hybrid microwave integrated circuit is adapted for a low noise design at this low frequency range. Discrete passive components with high-Q and large values are selected to integrate with the best low noise transistors to optimize the LNA performance. The first UHF band cryogenic LNA was designed with InP HEMTs in all three stages for Square Kilometer Array - mid telescope band-1 receiver. This LNA extended the low end frequency to 350 MHz, and achieved averaging 1.4 Kelvin of a record low noise temperature, more than 47 dB gain, and good input and output return losses < -10 dB over the broad bandwidth from 350 to 1050 MHz at 15 K. The second UHF band cryogenic LNA was developed for MeerKAT Array, a precursor of Square Kilometer Array. This LNA was designed with InP HEMT transistor at first stage to achieve best low noise performance and GaAs HEMTs for second and third stages to replace InP HEMTs and realize high gain and good amplitude stability at cryogenic temperature. The second LNA achieved a record low noise temperature of averaging 0.6 Kelvin, more than 45 dB gain, and good input and output return losses ≤ -12 dB over the wide bandwidth from 580 to 1070 MHz at 15 K.

  6. The Inchworm Deep Drilling System for Kilometer Scale Subsurface Exploration of Europa (IDDS)

    NASA Astrophysics Data System (ADS)

    Rafeek, S.; Gorevan, S. P.; Bartlett, P. W.; Kong, K. Y.

    2001-01-01

    The Inchworm Deep Drilling System (IDDS) is a compact subsurface transport system capable of accessing regions of astrobiological interest deep below the surface of Jupiter's moon, Europa. The IDDS answers Focus Investigation Area 1 as an innovative concept for implementing subsurface exploration of Europa. The concept is being developed at Honeybee Robotics to reach depths on the order of one kilometer with no tether or umbilical of any kind. The device's unique, inchworm-burrowing method appears capable of achieving this near-term depth goal and it is foreseeable that the IDDS will be capable of autonomously drilling to tens of kilometers below the surface. Logical applications of the concept also include accessing the proposed subsurface oceans on Ganymede and Callisto, subsurface water ice on Mars, and Lake Vostok on Earth. The conference presentation will communicate the IDDS concept and how it can enable the search for prebiotic and biotic chemical processes on Europa by bringing proper instrumentation to the subsurface ocean for in-situ investigation and/or returning samples to the surface. Currently, a proposal for breadboarding the IDDS is pending for the Research Opportunities for Space Science's Astrobiology Science and Technology Instrument Development NRA. Additional information is contained in the original extended abstract.

  7. Sub-Kilometer Scale Basal Roughness of the Siple Coast Ice Streams, West Antarctic Ice Sheet

    NASA Astrophysics Data System (ADS)

    Young, D. A.; Blankenship, D. D.; Peters, M. E.

    2006-12-01

    The anastomosing series of dynamic, basally lubricated ice streams found on the Siple Coast of West Antarctica play an important role in regulating the mass balance of the West Antarctic Ice Sheet (WAIS). Geological controls on lubrication, elucidated by gravity, magnetics and seismic data, have proven important in understanding the evolution of these features. An additional indicator of basal properties, the basal roughness of ice sheets, may be an indicator of crustal geology and glacial modification, as well as a controlling parameter on ice dynamics and subglacial hydrology. For the Siple Coast ice streams, Fourier analysis of > 5 kilometer morphology (Siegert et al. 2004) revealed a correlation between ice streams and low bed roughness. Coherent high resolution data allows analysis of along track roughness at tens of meters resolution (Peters et al. 2005), however these data are limited in coverage. We extend roughness estimates into to the hundreds-of-meters length scale, using both frequency domain and autocorrelation methods, using incoherent 60 MHz radio echo sounding data collected between 1991 and 1996 on a five kilometer grid. The data cover the Bentley Subglacial Trench, Bindschadler Ice Stream, Siple Dome and the onset region of Kamb Ice Stream. SAR-processed coherent sounding data collected in 2001 are used to confirm these methods. We test for confinement of ice stream rapid basal motion to distinct morphological provinces; assess the hypothesis that marine sediments blanket much of interior of the basal WAIS; and look for correlation between ice flow and textural anisotropy.

  8. Determination of the Telluric Water Vapor Absorption Correction for Astronomical Data Obtained from the Kuiper Airborne Observatory

    NASA Technical Reports Server (NTRS)

    Erickson, E. F.; Simpson, J. P.; Kuhn, P. M.; Stearns, L. P.

    1979-01-01

    The amount of telluric water vapor along the line of sight of the Kuiper Airborne Observatory telescope as obtained concommitantly on 23 flights is compared with the NASA-Ames Michelson interferometer and with the NOAA-Boulder radiometer. A strong correlation between the two determinations exists, and a method for computing the atmospheric transmission for a given radiometer reading is established.

  9. INITIAL PLANETESIMAL SIZES AND THE SIZE DISTRIBUTION OF SMALL KUIPER BELT OBJECTS

    SciTech Connect

    Schlichting, Hilke E.; Fuentes, Cesar I.; Trilling, David E.

    2013-08-01

    The Kuiper Belt is a remnant from the early solar system and its size distribution contains many important constraints that can be used to test models of planet formation and collisional evolution. We show, by comparing observations with theoretical models, that the observed Kuiper Belt size distribution is well matched by coagulation models, which start with an initial planetesimal population with radii of about 1 km, and subsequent collisional evolution. We find that the observed size distribution above R {approx} 30 km is primordial, i.e., it has not been modified by collisional evolution over the age of the solar system, and that the size distribution below R {approx} 30 km has been modified by collisions and that its slope is well matched by collisional evolution models that use published strength laws. We investigate in detail the resulting size distribution of bodies ranging from 0.01 km to 30 km and find that its slope changes several times as a function of radius before approaching the expected value for an equilibrium collisional cascade of material strength dominated bodies for R {approx}< 0.1 km. Compared to a single power-law size distribution that would span the whole range from 0.01 km to 30 km, we find in general a strong deficit of bodies around R {approx} 10 km and a strong excess of bodies around 2 km in radius. This deficit and excess of bodies are caused by the planetesimal size distribution left over from the runaway growth phase, which left most of the initial mass in small planetesimals while only a small fraction of the total mass is converted into large protoplanets. This excess mass in small planetesimals leaves a permanent signature in the size distribution of small bodies that is not erased after 4.5 Gyr of collisional evolution. Observations of the small Kuiper Belt Object (KBO) size distribution can therefore test if large KBOs grew as a result of runaway growth and constrained the initial planetesimal sizes. We find that results from

  10. NASA’s Hubble Telescope Finds Potential Kuiper Belt Targets for New Horizons Pluto Mission

    NASA Image and Video Library

    2017-09-28

    This is an artist’s impression of a Kuiper Belt object (KBO), located on the outer rim of our solar system at a staggering distance of 4 billion miles from the Sun. A HST survey uncovered three KBOs that are potentially reachable by NASA’s New Horizons spacecraft after it passes by Pluto in mid-2015. Credit: NASA, ESA, and G. Bacon (STScI) --- Peering out to the dim, outer reaches of our solar system, NASA’s Hubble Space Telescope has uncovered three Kuiper Belt objects (KBOs) the agency’s New Horizons spacecraft could potentially visit after it flies by Pluto in July 2015. The KBOs were detected through a dedicated Hubble observing program by a New Horizons search team that was awarded telescope time for this purpose. “This has been a very challenging search and it’s great that in the end Hubble could accomplish a detection – one NASA mission helping another,” said Alan Stern of the Southwest Research Institute (SwRI) in Boulder, Colorado, principal investigator of the New Horizons mission. The Kuiper Belt is a vast rim of primordial debris encircling our solar system. KBOs belong to a unique class of solar system objects that has never been visited by spacecraft and which contain clues to the origin of our solar system. The KBOs Hubble found are each about 10 times larger than typical comets, but only about 1-2 percent of the size of Pluto. Unlike asteroids, KBOs have not been heated by the sun and are thought to represent a pristine, well preserved deep-freeze sample of what the outer solar system was like following its birth 4.6 billion years ago. The KBOs found in the Hubble data are thought to be the building blocks of dwarf planets such as Pluto. Read more: 1.usa.gov/1vzUcyK NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling

  11. THE COLOR DIFFERENCES OF KUIPER BELT OBJECTS IN RESONANCE WITH NEPTUNE

    SciTech Connect

    Sheppard, Scott S.

    2012-12-01

    The optical colors of 58 objects in mean motion resonance with Neptune were obtained. The various Neptune resonant populations were found to have significantly different surface color distributions. The 5:3 and 7:4 resonances have semimajor axes near the middle of the main Kuiper Belt and both are dominated by ultra-red material (spectral gradient: S {approx}> 25). The 5:3 and 7:4 resonances have statistically the same color distribution as the low-inclination 'cold' classical belt. The inner 4:3 and distant 5:2 resonances have objects with mostly moderately red colors (S {approx} 15), similar to the scattered and detached disk populations. The 2:1 resonance, which is near the outer edge of the main Kuiper Belt, has a large range of colors with similar numbers of moderately red and ultra-red objects at all inclinations. The 2:1 resonance was also found to have a very rare neutral colored object showing that the 2:1 resonance is really a mix of all object types. The inner 3:2 resonance, like the outer 2:1, has a large range of objects from neutral to ultra-red. The Neptune Trojans (1:1 resonance) are only slightly red (S {approx} 9), similar to the Jupiter Trojans. The inner 5:4 resonance only has four objects with measured colors but shows equal numbers of ultra-red and moderately red objects. The 9:5, 12:5, 7:3, 3:1, and 11:3 resonances do not have reliable color distribution statistics since few objects have been observed in these resonances, though it appears noteworthy that all three of the measured 3:1 objects have only moderately red colors, similar to the 4:3 and 5:2 resonances. The different color distributions of objects in mean motion resonance with Neptune are likely a result from the disruption of the primordial Kuiper Belt from the scattering and migration of the giant planets. The few low-inclination objects known in the outer 2:1 and 5:2 resonances are mostly only moderately red. This suggests if the 2:1 and 5:2 have a cold low-inclination component

  12. The Color Differences of Kuiper Belt Objects in Resonance with Neptune

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott S.

    2012-12-01

    The optical colors of 58 objects in mean motion resonance with Neptune were obtained. The various Neptune resonant populations were found to have significantly different surface color distributions. The 5:3 and 7:4 resonances have semimajor axes near the middle of the main Kuiper Belt and both are dominated by ultra-red material (spectral gradient: S >~ 25). The 5:3 and 7:4 resonances have statistically the same color distribution as the low-inclination "cold" classical belt. The inner 4:3 and distant 5:2 resonances have objects with mostly moderately red colors (S ~ 15), similar to the scattered and detached disk populations. The 2:1 resonance, which is near the outer edge of the main Kuiper Belt, has a large range of colors with similar numbers of moderately red and ultra-red objects at all inclinations. The 2:1 resonance was also found to have a very rare neutral colored object showing that the 2:1 resonance is really a mix of all object types. The inner 3:2 resonance, like the outer 2:1, has a large range of objects from neutral to ultra-red. The Neptune Trojans (1:1 resonance) are only slightly red (S ~ 9), similar to the Jupiter Trojans. The inner 5:4 resonance only has four objects with measured colors but shows equal numbers of ultra-red and moderately red objects. The 9:5, 12:5, 7:3, 3:1, and 11:3 resonances do not have reliable color distribution statistics since few objects have been observed in these resonances, though it appears noteworthy that all three of the measured 3:1 objects have only moderately red colors, similar to the 4:3 and 5:2 resonances. The different color distributions of objects in mean motion resonance with Neptune are likely a result from the disruption of the primordial Kuiper Belt from the scattering and migration of the giant planets. The few low-inclination objects known in the outer 2:1 and 5:2 resonances are mostly only moderately red. This suggests if the 2:1 and 5:2 have a cold low-inclination component, the objects likely

  13. A possible divot in the Kuiper belt's scattered-object size distribution

    NASA Astrophysics Data System (ADS)

    Shankman, C.; Kavelaars, J.; Gladman, B.; Petit, J.

    2014-07-01

    The formation and evolution history of the Solar System, while not directly accessible, has measurable signatures in the present-day size distributions of the Trans-Neptunian Object (TNO) populations. The form of the size distribution is modelled as a power law with number going as size to some characteristic slope. Recent works have shown that a single power law does not match the observations across all sizes; the power law breaks to a different form [1, 2, 3]. The large- size objects record the accretion history, while the small-size objects record the collision history. The changes of size-distribution shape and slope as one moves from 'large' to 'medium' to 'small' KBOs are the signature needed to constrain the formation and collision history of the Solar System. The scattering TNOs are those TNOs undergoing strong (scattering) interactions Neptune. The scattering objects can come to pericentre in the giant planet region. This close-in pericentre passage allows for the observation of smaller objects, and thus for the constraint of the small-size end of the size distribution. Our recent analysis of the Canada France Ecliptic Plane Survey's (CFEPS) scattering objects revealed an exciting potential form for the scattering object size distribution - a divot (see Figure). Our divot (a sharp drop in the number of objects per unit size which then returns at a potentially different slope) matches our observations well and can simultaneously explain observed features in other inclined (so-called "hot") Kuiper Belt populations. In this scenario all of the hot populations would share the same source and have been implanted in the outer solar system through scattering processes. If confirmed, our divot would represent a new exciting paradigm for the formation history of the Kuiper Belt. Here we present the results of an extension of our previous work to include a new, deeper, Kuiper Belt survey. By the addition of two new faint scattering objects from this survey which

  14. The effects of B0, B20 and B100 soy biodiesel exhaust on aconitine-induced cardiac arrhythmia in spontaneously hypertensive rats

    EPA Science Inventory

    CONTEXT: Diesel exhaust (DE) has been shown to increase the risk of cardiac arrhythmias. Although biodiesel has been proposed as a "safer" alternative to diesel, it is still uncertain whether it actually poses less threat.OBJECTIVE: We hypothesized that exposure to pure or 20% so...

  15. Military Curricula for Vocational & Technical Education. Basic Electronics School. CANTRAC A-100-0010. Modules 20-22: Power Supplies, Amplifiers, Oscillators. Progress Checks.

    ERIC Educational Resources Information Center

    Chief of Naval Education and Training Support, Pensacola, FL.

    This document contains student progress checks designed for use with individualized modules 20-22 in the military-developed course on basic electricity and electronics. The course is one of a number of military-developed curriculum packages selected for adaptation to vocational instructional and curriculum development in a civilian setting. One…

  16. 20 CFR 663.100 - What is the role of the adult and dislocated worker programs in the One-Stop delivery system?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false What is the role of the adult and dislocated... AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the...

  17. 20 CFR 663.100 - What is the role of the adult and dislocated worker programs in the One-Stop delivery system?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false What is the role of the adult and dislocated... AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services...

  18. 20 CFR 663.100 - What is the role of the adult and dislocated worker programs in the One-Stop delivery system?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false What is the role of the adult and dislocated... AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services...

  19. 20 CFR 663.100 - What is the role of the adult and dislocated worker programs in the One-Stop delivery system?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false What is the role of the adult and dislocated... AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services...

  20. The effects of B0, B20 and B100 soy biodiesel exhaust on aconitine-induced cardiac arrhythmia in spontaneously hypertensive rats

    EPA Science Inventory

    CONTEXT: Diesel exhaust (DE) has been shown to increase the risk of cardiac arrhythmias. Although biodiesel has been proposed as a "safer" alternative to diesel, it is still uncertain whether it actually poses less threat.OBJECTIVE: We hypothesized that exposure to pure or 20% so...

  1. Application of the Shuttle Laser Altimeter in an Accuracy Assessment of Global 1-Kilometer Digital Elevation Data

    NASA Technical Reports Server (NTRS)

    Harding, David J.; Carabajal, Claudia C.; Luthcke, Scott B.; Gesch, Dean B.

    1998-01-01

    Shuttle Laser Altimeter (SLA) data have been used to evaluate the accuracy of GTOPO30, the first comprehensive, 1 km resolution, global topographic data set. GTOPO30 was developed by the USGS Eros Data Center (EDC), in part, to address NASA's needs for a global topographic model in support of remote sensing instruments aboard the Earth Observing System AM-1 spacecraft. SLA flew as a part of the STS-72 mission in January, 1996 observing the latitude band from +/- 28.5 deg, and on STS-85 in August, 1997 extending the observations to +/- 57 deg. Combining the SLA ranging data with shuttle position and pointing knowledge yields surface elevation data of very high vertical accuracy in an Earth-centered, absolute reference frame (2.8 m rms difference for SLA-01 with respect to ocean reference surface). Use of the well-determined mean sea surface reference for calibration allows propagation of high accuracy altimetry onto the continents. 436,635 SLA-01 land elevations were compared to the GTOPO30 grid after conversion to a mean sea level vertical datum using the Earth Geoid Model 96, jointly developed by Goddard and NIMA. The comparison reveals systematic elevation biases in southern Asia, Africa, Australia, and south America on the order 10's to 100 meters in the GTOPO30 compilation on spatial scales of 100's to 1000's of kilometers. These biases are likely due to vertical datum errors in the topographic source materials used to compile GTOPO30, which primarily consist of Defense Mapping Agency (DMA) digital elevation and topographic map products. These biases imply that elevation corrections applied to land gravity measurements using these DMA source materials will be biased, leading to errors in geoid models incorporating these land gravity data.

  2. Measurements of magneto-Rayleigh-Taylor instability growth during the implosion of initially solid Al tubes driven by the 20-MA, 100-ns Z facility.

    PubMed

    Sinars, D B; Slutz, S A; Herrmann, M C; McBride, R D; Cuneo, M E; Peterson, K J; Vesey, R A; Nakhleh, C; Blue, B E; Killebrew, K; Schroen, D; Tomlinson, K; Edens, A D; Lopez, M R; Smith, I C; Shores, J; Bigman, V; Bennett, G R; Atherton, B W; Savage, M; Stygar, W A; Leifeste, G T; Porter, J L

    2010-10-29

    The first controlled experiments measuring the growth of the magneto-Rayleigh-Taylor instability in fast (∼100  ns) Z-pinch plasmas are reported. Sinusoidal perturbations on the surface of an initially solid Al tube (liner) with wavelengths of 25-400  μm were used to seed the instability. Radiographs with 15  μm resolution captured the evolution of the outer liner surface. Comparisons with numerical radiation magnetohydrodynamic simulations show remarkably good agreement down to 50  μm wavelengths.

  3. New Horizons: Long-Range Kuiper Belt Targets Observed by the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Benecchi, S. D.; Noll, K. S.; Weaver, H. A.; Spencer, J. R.; Stern, S. A.; Buie, M. W.; Parker, A. H.

    2014-01-01

    We report on Hubble Space Telescope (HST) observations of three Kuiper Belt Objects (KBOs), discovered in our dedicated ground-based search campaign, that are candidates for long-range observations from the New Horizons spacecraft: 2011 epochY31, 2011 HZ102, and 2013 LU35. Astrometry with HST enables both current and future critical accuracy improvements for orbit precision, required for possible New Horizons observations, beyond what can be obtained from the ground. Photometric colors of all three objects are red, typical of the Cold Classical dynamical population within which they reside; they are also the faintest KBOs to have had their colors measured. None are observed to be binary with HST above separations of approx. 0.02 arcsec (approx. 700 km at 44 AU) and delta m less than or equal to 0.5.

  4. Real Time Data/Video/Voice Uplink and Downlink for Kuiper Airborne Observatory

    NASA Technical Reports Server (NTRS)

    Harper, Doyal A.

    1997-01-01

    LFS was an educational outreach adventure which brought the excitement of astronomical exploration on NASA's Kuiper Airborne Observatory (KAO) to a nationwide audience of children, parents and children through live, interactive television, broadcast from the KAO at an altitude of 41,000 feet during an actual scientific observing mission. The project encompassed three KAO flights during the fall of 1995, including a short practice mission, a daytime observing flight between Moffett Field, California to Houston, Texas, and a nighttime mission from Houston back to Moffett Field. The University of Chicago infrared research team participated in planning the program, developing auxiliary materials including background information and lesson plans, developing software which allowed students on the ground to control the telescope and on-board cameras via the Internet from the Adler Planetarium in Chicago, and acting as on-camera correspondents to explain and answer questions about the scientific research conducted during the flights.

  5. Co1lisional Grooming Models of the Kuiper Belt Dust Cloud

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2010-01-01

    Debris disks around other stars, like the disks around Fomalhaut, Vega, and Epsilon Eridani, are often described as more massive versions of the Kuiper Belt. But for a long time, it's been hard to test this notion, because grain-grain collisions limit the grain lifetimes and we lacked the tools to model the effects of these collisions on the appearance of the disks. I'll describe a new breakthrough that has allowed us to make 3-D models of grain-grain collisions in debris disks for the first time, and I'll show the latest supercomputer simulations of these systems, illustrating how planets and collisions together sculpt the TNO dust.

  6. The Kuiper Belt, Exozodiacal Dust, Debris Disks: It's All About Collisions

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2010-01-01

    Debris disks around other stars, like the disks around Fomalhaut, Vega, and Epsilon Eridani, are often described as more massive versions of the Kuiper Belt. But for a long time, it's been hard to test this notion, because grain-grain collisions dominate the grain lifetimes and we lacked the tools to model the effect of collisions on the appearance of the disks. I'll describe a new breakthrough that has allowed us to make 3-D models of collisions in debris disks and exozodiacal clouds for the first time, and I'll show the latest supercomputer simulations of these systems, illustrating the effects of planets and collisions in sculpting these disks. These models will be the key to interpreting debris disk images from HST, Herschel, SOFIA, JWST, and ALMA, as well as understanding the exozodiacal dust backgrounds for direct imaging of exo-Earths.

  7. The moon of the large Kuiper-belt object 2007 OR 10

    NASA Astrophysics Data System (ADS)

    Marton, Gabor; Kiss, Csaba; Mueller, Thomas G.

    2016-10-01

    We have identified a candidate satellite of the large Kuiper-belt object 2007 OR10. The moon has clearly been observed in one set of images and we obtained a tentative detection in a previous epoch. The moon orbits the central body at a distance of at least 15 000 km. Apart from this satellite no sign of binarity was observed, i.e. 2007 OR10 is likely a single large body. The low brightness of the moon also indicates that it cannot contribute notably to the total thermal emission of the system, i.e. 2007 OR10 has a size of ~1535 km obtained previously from Herschel and K2 data.

  8. Unsupervised clustering analysis of normalized spectral reflectance data for the Rudaki/Kuiper area on Mercury

    NASA Astrophysics Data System (ADS)

    D'Amore, M.; Helbert, J.; Maturilli, A.; D'Incecco, P.; Holsclaw, G. M.; McClintock, W. E.; Solomon, S. C.

    2013-09-01

    We present a study of spectral reflectance data from Mercury focused on an area that encompasses the craters Kuiper-Murasaki, Rudaki, and Waters. The goal is to identify different spectral units and analyze potential relations among them. The study region is geologically and spectrally classified as heavily cratered intermediate terrain (IT) with mixed patches of high-reflectance red plains (HRP) and intermediate plains (IP), on the basis of multispectral images taken by the Mercury Dual Imaging System (MDIS) [1]. Recent analysis of observations by the Mercury Atmospheric and Surface Composition Spectrometer (MASCS) instrument on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft with an unsupervised hierarchical clustering method shows a comparable number of units at global scales [2,3]. Analyses on the local scale reveal a larger number of spectral units with a substantially more complex relationship among units.

  9. The Kuiper Airborne Observatory As an Educational Tool-The FOSTER Project

    NASA Astrophysics Data System (ADS)

    Koch, D.; Hull, G.; Gillespie, C.; Devore, E.

    1993-05-01

    Each research flight of the Kuiper Airborne Observatory (KAO) is a microcosm of the scientific method. A pilot project has been initiated to provide Flight Opportunities for Science Teacher EnRichment (FOSTER) on-board the KAO whereby each teacher will obtain first-hand experience of the scientific process: its excitement, hardships, challenges, discoveries, teamwork, social relevance and educational value. The FOSTER project is providing to each teacher a workshop on contemporary astrophysics and curriculum supplement materials as well as the flight opportunity. The objective is to provide an enriching experience that the teachers will then take back to the classroom, so that each student will have a more meaningful science education. The 1992-93 school year is the first year of the pilot program, which after five years should expand to the national level and be flying 50 teachers per year. The project is supported by the IDEA program of the Astrophysics Division at NASA Headquarters.

  10. The Kuiper Belt, Exozodiacal Dust, Debris Disks: It's All About Collisions

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2010-01-01

    Debris disks around other stars, like the disks around Fomalhaut, Vega, and Epsilon Eridani, are often described as more massive versions of the Kuiper Belt. But for a long time, it's been hard to test this notion, because grain-grain collisions dominate the grain lifetimes and we lacked the tools to model the effect of collisions on the appearance of the disks. I'll describe a new breakthrough that has allowed us to make 3-D models of collisions in debris disks and exozodiacal clouds for the first time, and I'll show the latest supercomputer simulations of these systems, illustrating the effects of planets and collisions in sculpting these disks. These models will be the key to interpreting debris disk images from HST, Herschel, SOFIA, JWST, and ALMA, as well as understanding the exozodiacal dust backgrounds for direct imaging of exo-Earths.

  11. Structure and Evolution of Kuiper Belt Objects: The Case for Compositional Classes

    NASA Astrophysics Data System (ADS)

    McKinnon, William B.; Prialnik, D.; Stern, S. A.

    2007-10-01

    Kuiper belt objects (KBOs) accreted from a mélange of ices, carbonaceous matter, and rock of mixed interstellar and solar nebular provenance. The transneptunian region, where this accretion took place, was likely more radially compact than today. This and the influence of gas drag during the solar nebula epoch argue for more rapid KBO accretion than usually considered. Early evolution of KBOs was largely the result of radiogenic heating, with both short-term and long-term contributions being potentially important. Depending on rock content and porous conductivity, KBO interiors may have reached relatively high temperatures. Models suggest that KBOs likely lost very volatile ices during early evolution, whereas less volatile ices should be retained in cold, less altered subsurface layers; initially amorphous ice may have crystallized in the interior as well, releasing trapped volatiles. Generally, KBOs should be stratified in terms of composition and porosity, albeit subject to impact disruption and collisional stripping. KBOs are thus unlikely to be "the most pristine objects in the Solar System.” Large (dwarf planet) KBOs may be fully differentiated. KBO surface color and compositional classes are usually discussed in terms of "nature vs. nurture,” i.e., a generic primordial composition vs. surface processing, but the true nature of KBOs also depends on how they have evolved. The broad range of albedos now found in the Kuiper belt, deep water-ice absorptions on some objects, evidence for differentiation of Pluto and 2003 EL61, and a range of densities incompatible with a single, primordial composition and variable porosity strongly imply significant, intrinsic compositional differences among KBOs. The interplay of formation zone (accretion rate), body size, and dynamical (collisional) history may yield KBO compositional classes (and their spectral correlates) that recall the different classes of asteroids in the inner Solar System, but whose members are

  12. NEPTUNE'S WILD DAYS: CONSTRAINTS FROM THE ECCENTRICITY DISTRIBUTION OF THE CLASSICAL KUIPER BELT

    SciTech Connect

    Dawson, Rebekah I.; Murray-Clay, Ruth

    2012-05-01

    Neptune's dynamical history shaped the current orbits of Kuiper Belt objects (KBOs), leaving clues to the planet's orbital evolution. In the 'classical' region, a population of dynamically 'hot' high-inclination KBOs overlies a flat 'cold' population with distinct physical properties. Simulations of qualitatively different histories for Neptune, including smooth migration on a circular orbit or scattering by other planets to a high eccentricity, have not simultaneously produced both populations. We explore a general Kuiper Belt assembly model that forms hot classical KBOs interior to Neptune and delivers them to the classical region, where the cold population forms in situ. First, we present evidence that the cold population is confined to eccentricities well below the limit dictated by long-term survival. Therefore, Neptune must deliver hot KBOs into the long-term survival region without excessively exciting the eccentricities of the cold population. Imposing this constraint, we explore the parameter space of Neptune's eccentricity and eccentricity damping, migration, and apsidal precession. We rule out much of parameter space, except where Neptune is scattered to a moderately eccentric orbit (e > 0.15) and subsequently migrates a distance {Delta}a{sub N} = 1-6 AU. Neptune's moderate eccentricity must either damp quickly or be accompanied by fast apsidal precession. We find that Neptune's high eccentricity alone does not generate a chaotic sea in the classical region. Chaos can result from Neptune's interactions with Uranus, exciting the cold KBOs and placing additional constraints. Finally, we discuss how to interpret our constraints in the context of the full, complex dynamical history of the solar system.

  13. Considerations on the magnitude distributions of the Kuiper belt and of the Jupiter Trojans

    NASA Astrophysics Data System (ADS)

    Morbidelli, Alessandro; Levison, Harold F.; Bottke, William F.; Dones, Luke; Nesvorný, David

    2009-07-01

    By examining the absolute magnitude (H) distributions (hereafter HD) of the cold and hot populations in the Kuiper belt and of the Trojans of Jupiter, we find evidence that the Trojans have been captured from the outer part of the primordial trans-neptunian planetesimal disk. We develop a sketch model of the HDs in the inner and outer parts of the disk that is consistent with the observed distributions and with the dynamical evolution scenario known as the 'Nice model'. This leads us to predict that the HD of the hot population should have the same slope of the HD of the cold population for 6.5 < H < 9, both as steep as the slope of the Trojans' HD. Current data partially support this prediction, but future observations are needed to clarify this issue. Because the HD of the Trojans rolls over at H ∼ 9 to a collisional equilibrium slope that should have been acquired when the Trojans were still embedded in the primordial trans-neptunian disk, our model implies that the same roll-over should characterize the HDs of the Kuiper belt populations, in agreement with the results of Bernstein et al. [Bernstein, G.M., and 5 colleagues, 2004. Astron. J. 128, 1364-1390] and Fuentes and Holman [Fuentes, C.I., Holman, M.J., 2008. Astron. J. 136, 83-97]. Finally, we show that the constraint on the total mass of the primordial trans-neptunian disk imposed by the Nice model implies that it is unlikely that the cold population formed beyond 35 AU.

  14. Models of the collisional damping scenario for ice-giant planets and Kuiper belt formation

    NASA Astrophysics Data System (ADS)

    Levison, Harold F.; Morbidelli, Alessandro

    2007-07-01

    Chiang et al. [Chiang, E., Lithwick, Y., Murray-Clay, R., Buie, M., Grundy, W., Holman, M., 2007. In: Protostars and Planets V, pp. 895-911] have recently proposed that the observed structure of the Kuiper belt could be the result of a dynamical instability of a system of ˜5 primordial ice-giant planets in the outer Solar System. According to this scenario, before the instability occurred, these giants were growing in a highly collisionally damped environment according to the arguments in Goldreich et al. [Goldreich, P., Lithwick, Y., Sari, R., 2004. Astrophys. J. 614, 497-507; Annu. Rev. Astron. Astrophys. 42, 549-601]. Here we test this hypothesis with a series of numerical simulations using a new code designed to incorporate the dynamical effects of collisions. We find that we cannot reproduce the observed Solar System. In particular, Goldreich et al. [Goldreich, P., Lithwick, Y., Sari, R., 2004. Astrophys. J. 614, 497-507; Annu. Rev. Astron. Astrophys. 42, 549-601] and Chiang et al. [Chiang, E., Lithwick, Y., Murray-Clay, R., Buie, M., Grundy, W., Holman, M., 2007. In: Protostars and Planets V, pp. 895-911] argue that during the instability, all but two of the ice giants would be ejected from the Solar System by Jupiter and Saturn, leaving Uranus and Neptune behind. We find that ejections are actually rare and that instead the systems spread outward. This always leads to a configuration with too many planets that are too far from the Sun. Thus, we conclude that both Goldreich et al.'s scheme for the formation of Uranus and Neptune and Chiang et al.'s Kuiper belt formation scenario are not viable in their current forms.

  15. Will new horizons see dust clumps in the Edgeworth-Kuiper Belt?

    SciTech Connect

    Vitense, Christian; Krivov, Alexander V.; Löhne, Torsten

    2014-06-01

    Debris disks are thought to be sculptured by neighboring planets. The same is true for the Edgeworth-Kuiper debris disk, yet no direct observational evidence for signatures of giant planets in the Kuiper Belt dust distribution has been found so far. Here we model the dust distribution in the outer solar system to reproduce the dust impact rates onto the dust detector on board the New Horizons spacecraft measured so far and to predict the rates during the Neptune orbit traverse. To this end, we take a realistic distribution of trans-Neptunian objects to launch a sufficient number of dust grains of different sizes and follow their orbits by including radiation pressure, Poynting-Robertson and stellar wind drag, as well as the perturbations of four giant planets. In a subsequent statistical analysis, we calculate number densities and lifetimes of the dust grains in order to simulate a collisional cascade. In contrast to the previous work, our model not only considers collisional elimination of particles but also includes production of finer debris. We find that particles captured in the 3:2 resonance with Neptune build clumps that are not removed by collisions, because the depleting effect of collisions is counteracted by production of smaller fragments. Our model successfully reproduces the dust impact rates measured by New Horizons out to ≈23 AU and predicts an increase of the impact rate of about a factor of two or three around the Neptune orbit crossing. This result is robust with respect to the variation of the vaguely known number of dust-producing scattered disk objects, collisional outcomes, and the dust properties.

  16. Interpretation of the Near-IR Spectra of the Kuiper Belt Object

    NASA Technical Reports Server (NTRS)

    Eluszkiewicz, Janusz; Cady-Pereira, Karen; Brown, Michael E.; Stansberry, John A.

    2007-01-01

    Visible and near-IR observations of the Kuiper Belt Object (136472) 2005 FY(9) have indicated the presence of unusually long (1 cm or more) optical path lengths in a layer of methane ice. Using microphysical and radiative transfer modeling, we show that even at the frigid temperatures in the outer reaches of the solar system, a slab of low porosity methane ice can indeed form by pressureless sintering of micron-sized grains, and it can qualitatively reproduce the salient features of the measured spectra. A good semiquantitative match with the near-IR spectra can be obtained with a realistic slab model, provided the spectra are scaled to a visible albedo of 0.6, at the low end of the values currently estimated from Spitzer thermal measurements. Consistent with previous modeling studies, matching spectra scaled to higher albedos requires the incorporation of strong backscattering effects. The albedo may become better constrained through an iterative application of the slab model to the analysis of the thermal measurements from Spitzer and the visible/near-IR reflectance spectra. The slab interpretation offers two falsifiable predictions (1) Absence of an opposition surge, which is commonly attributed to the fluffiness of the optical surface. This prediction is best testable with a spacecraft, as Earth-based observations at true opposition will not be possible until early next century. (2) Unlikelihood of the simultaneous occurrence of very long spectroscopic path lengths in both methane and nitrogen ice on the surface of any Kuiper Belt Object, as the more volatile nitrogen would hinder densification in methane ice.

  17. A PHOTOMETRIC SYSTEM FOR DETECTION OF WATER AND METHANE ICES ON KUIPER BELT OBJECTS

    SciTech Connect

    Trujillo, Chadwick A.; Sheppard, Scott S.; Schaller, Emily L. E-mail: sheppard@dtm.ciw.edu

    2011-04-01

    We present a new near-infrared photometric system for detection of water ice and methane ice in the solar system. The system consists of two medium-band filters in the K-band region of the near-infrared, which are sensitive to water ice and methane ice, plus continuum observations in the J band and Y band. The primary purpose of this system is to distinguish between three basic types of Kuiper Belt Objects (KBOs)-those rich in water ice, those rich in methane ice, and those with little absorbance. In this work, we present proof-of-concept observations of 51 KBOs using our filter system, 21 of which have never been observed in the near-infrared spectroscopically. We show that our custom photometric system is consistent with previous spectroscopic observations while reducing telescope observing time by a factor of {approx}3. We use our filters to identify Haumea collisional family members, which are thought to be collisional remnants of a much larger body and are characterized by large fractions of water ice on their surfaces. We add 2009 YE{sub 7} to the Haumea collisional family based on our water ice band observations (J - H{sub 2}O = -1.03 {+-} 0.27) which indicate a high amount of water ice absorption, our calculated proper orbital elements, and the neutral optical colors we measured, V - R = 0.38 {+-} 0.04, which are all consistent with the rest of the Haumea family. We identify several objects dynamically similar to Haumea as being distinct from the Haumea family as they do not have water ice on their surfaces. In addition, we find that only the largest KBOs have methane ice, and Haumea itself has significantly less water ice absorption than the smaller Haumea family members. We find no evidence for other families in the Kuiper Belt.

  18. Kuiper: A Discovery-class Observatory for Giant Planets, Satellites, and Small Bodies

    NASA Astrophysics Data System (ADS)

    Bell, James F.; Schneider, Nicholas M.; Brown, Michael E.; Clarke, John T.; Greenhagen, Benjamin T.; Hendrix, Amanda R.; Wong, Michael H.

    2014-11-01

    The recent Planetary Decadal identified important science goals for the study of the outer solar system. However, after the end of the Cassini and Juno missions in 2017, outer solar system science might face over a decade without new U.S. missions. The Survey thus noted the critical role that space-based telescopic observations, especially those enabling significant time-domain and target coverage, can play in advancing key planetary science questions. We propose a dedicated planetary space telescope, implementable in the Discovery program, to conduct three diverse investigations. Named after pioneering planetary astronomer Gerard P. Kuiper, the mission will address 9 of the 10 Decadal's Key Questions by studying 1) the giant planets, 2) their major satellites, and 3) the panoply of small bodies that populate the outer solar system. These three diverse investigations will enable significant advances in outer solar system science, through time-domain observations and substantial time on the targets. Advances in understanding the connections between weather and climate in giant planet atmospheres, as well as the interactions between giant planet atmospheres, satellites, and their external environments (e.g., auroral, solar wind, plumes, impacts), require consistent, well-calibrated, nearly-continuous observations spanning timescales from hours to years. Progress in understanding the ways that small outer solar system bodies can be used to understand the details of early giant planet migration requires compositional knowledge of statistically significant members of key dynamical populations. Observations with the required temporal coverage and fidelity needed to address these and many other important outer solar system Decadal science goals simply cannot be obtained from ground-based telescopes, or existing or planned space telescopes. Kuiper's combination of spatial resolution, spectral resolution, UV to near-IR coverage, and substantial time-domain sampling will

  19. Formation of the extreme Kuiper-belt binary 2001 QW322

    NASA Astrophysics Data System (ADS)

    Farrelly, David; Gamboa Suárez, A.; Hestroffer, D.

    2009-05-01

    Kuiper-belt binaries (KBBs) provide an invaluable window into conditions in the primordial solar system. Several mechanisms for the formation of KBBs have been proposed including; two-body collisions inside the Hill sphere of a larger body (Weidenschilling, Icarus, 160, 212, 2002); strong dynamical friction (Goldreich, et al., Nature, 420, 643, 2002); exchange reactions (Funato, et al., Nature, 427, 518, 2004) and chaos assisted capture (CAC, Astakhov, et al., MNRAS, 360, 401, 2005). The recently characterized mutual orbit of the symmetric (i.e., roughly equal mass) KBB 2001 QW322 is an outlier even among the already unusual population of Kuiper-belt binaries (Petit, et al., Science, 322, 432, 2008): the orbit is extremely large (≈ 105 km or about 30% of the Hill sphere radius), retrograde, inclined ≈ 120° from the ecliptic and with eccentricity e ≤ 0.4 (and possibly e ≤ 0.05). The large, almost circular, orbit probably precludes orbit reduction through tidal dissipation and likely also rules out strong dynamical friction (which predicts much tighter orbits), exchange (which predicts high eccentricities) and CAC (which produces non-circular orbits). While a collisional mechanism is possible, the probability of forming such a large, near-Keplerian, orbit in this way seems unlikely. A study of non-linear dynamics of the system suggests a hybrid formation mechanism as follows: (i) CAC into a long-living orbit close to a periodic orbit in Hill's problem; (ii) stabilization by gravitational scattering; (iii) weak dynamical friction then switches the original orbit ``adiabatically'' into a large, almost circular, retrograde orbit similar to that actually observed. The sense of the orbital angular momentum behaves as an adiabatic invariant (Astakhov, et al., Nature, 423, 264, 2003). Binaries like QW322 may be rare because they are hard to detect. Our calculations suggest that this object may be the harbinger of a larger population of such extreme binaries.

  20. Overview of South‐east Asia land cover using a NOAA AVHRR one kilometer composite

    USGS Publications Warehouse

    Defourny, Pierre; Pradhan, Udai C.; Vinay, Sritharan; Johnson, Gary E.

    1994-01-01

    A cloud free AVHRR composite of South‐East Asia at one kilometer resolution has been produced from 38 selected daily NOAA‐11 AVHRR images. Geometric accuracy of about 1 pixel is achieved using a two‐step rectification algorithm (orbital model and transformation by ground control points). A spatial and spectral enhancement has been performed, the sea masked out and political boundaries included in the final product. This AVHRR composite is particularly useful for a comprehensive overview of land cover at a regional scale. Qualitative comparison between a monthly composite and the existing forest maps highlights the forest cover change and points out the hot spots where the maps have to be updated.