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. PMID:17797089

  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. Photographer: JPL P-21752 C Range: 1.2 million kilometers This image of Europa shows detail about 20

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Photographer: JPL P-21752 C Range: 1.2 million kilometers This image of Europa shows detail about 20 kilometers across and is somewhat higher resolution than the best Voyager 1 image. The part of Europa shown is the hemisphere that will be viewed at even higher resolution during another Voyager 2 encounter with Europa. Color reconstruction in this image was slightly enhanced to bring out detail in the complicated mottled region on the west limb, containing some of the linear fracture-like features discovered by Voyager 1. The regions in the north and south polar areas which appear bluish in this version are in fact white.

  5. Kuiper Belt Objects (Invited)

    NASA Astrophysics Data System (ADS)

    Tegler, S. C.; Romanishin, W.

    1999-09-01

    The Kuiper belt represents an exciting, new frontier in solar system research. About 200 Kuiper belt objects (KBOs) with diameters larger than 100 km are known to exist between 30 and 50 AU from the Sun. Surveys indicate that there may be as many as 100,000 KBOs larger than 100 km and perhaps billions of KBOs larger than 1 km between 30 and 50 AU. Although the total mass in these bodies is perhaps a few tenths of an Earth mass, accretion calculations indicate that the primordial Kuiper belt must have contained 10 to 30 Earth masses of material between 30 and 50 AU in order to explain the growth of large KBOs and the Pluto and Charon system in the 100 million years before the onset of the disruptive influence of Neptune. Once Neptune reached a fraction of its current mass, dynamical studies indicate that a combination of erosional collisions and mean motion and secular resonances sculpted the belt into its present day mass and structure. The influence of the resonances can be seen in the belt today as about one-third of the known KBOs are in a stable 2:3 mean motion resonance with Neptune, i.e. eccentric and inclined orbits, that approach or cross the orbit of Neptune, and semi-major axes, a, about 39.4 AU. Many KBOs with a > 42 AU are sufficiently far from Neptune that they are on stable, low inclination, low eccentricity, non-resonant orbits. A combination of resonances and disruptive collisions continue to deplete the Kuiper belt today as they inject KBOs or collision fragments inward into the solar system as Centaur objects and Jupiter family comets. Physical studies of KBOs are in their infancy. Perhaps one of the most surprising results is the observation that KBO colors and hence their surface compositions divide neatly into a grey and an extraordinarily red population. The red population suggests some surfaces are rich in complex carbon-bearing molecules. The colors exhibit no trend with resonant or non-resonant orbits or object size and suggest that

  6. 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)...

  7. 49 CFR 179.100-20 - Stamping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... plates in conformance with the applicable requirements prescribed in § 179.24(a). Tank cars built before... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100-20 Stamping. (a) To certify that...

  8. Alternations in plasma volume and protein during and after a continuous 110-kilometer march with 20-kilogram backpack load.

    PubMed

    Ashkenazi, I; Epshtein, Y

    1998-10-01

    The purpose of this study was to determine the effect of a continuous 110-km march with a 20-kg backpack load on plasma volume and intravascular protein content. Twenty-two healthy male volunteers, aged 19 to 20 years (mean, 19.4 years), physically conditioned for continuous strenuous exercise, with a mean (+/- SD) maximal oxygen consumption of 59.1 (+/- 7.9) ml/kg/min, participated in the study. The march was performed under ambient conditions of 17 to 32 degrees C dry temperature and 45 to 85% relative humidity. Venous blood samples were obtained before, during, and after the march. The average calculated oxygen consumption during the march was about 30% of maximal oxygen consumption. Mean body weight loss was 3.4% of the premarch weight, mean water ingestion was 14,250 ml, and mean urine volume was 2,687 ml. Relative changes of plasma volume and total content of plasma protein were calculated from hematocrit ratio and hemoglobin concentration. A significant reduction (-6.1 +/- 1.7%, mean +/- SE) in plasma volume and a minimal elevation in intravascular protein content (1.6 +/- 2.5%) were observed during the march. During the first 24 hours of recovery, plasma volume was further reduced (-8.4 +/- 1.8%), with a significant reduction in protein content (-6.6 +/- 1.8%), mainly albumin (-9.3 +/- 1.7%). During the second day of recovery, peak elevations in plasma volume (3.7 +/- 1.4%) and protein content (6.0 +/- 1.6%) were observed. The changes in protein content were related to elevations in albumin (3.7 +/- 1.3%) and globulin (10.7 +/- 3.2%) content. The elevated plasma volume and protein content were also maintained 96 hours after the end of the march. Although the changes in plasma volume during the march were associated with changes in serum albumin and globulin content, during the recovery period there was association only with the changes in serum globulin content. The possible mechanism of these findings is discussed.

  9. A Possible Divot in the Size Distribution of the Kuiper Belt's Scattering Objects

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

    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°.

  10. 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 .

  11. Kuiper Express: a sciencecraft

    NASA Astrophysics Data System (ADS)

    Rodgers, David H.; Alkalai, Leon; Beauchamp, Patricia M.; Chen, Gun-Shing; Crisp, Michael P.; Brown, Robert H.; Davidson, J. M.; Huxtable, Douglas D.; Penzo, P. A.; Petrick, Stanley W.; Soderblom, Laurance A.; Stewart, A.; Vane, Gregg; Yelle, Roger V.

    1996-10-01

    The Kuiper Express is a mission to achieve the first reconnaissance of one of the primitive objects that reside in the Kuiper Belt. The objects in the Kuiper Belt are the remnants of the planetesimal swarm that formed the four giant planets of the outer Solar System. These objects, because they are far from the Sun, have not been processed by solar heating and are essentially in their primordial state. This makes them unique objects and their study will provide information on the composition of the solar nebula that cannot be extracted from a study of other objects in the Solar System. The Kuiper Express is a sciencecraft mission. A sciencecraft is an integrated unit that combines into a single system the essential elements (but no more) necessary to achieve the science objectives of the mission, including science instruments, electronics, telecommunications, power, and propulsion. The design of a sciencecraft begins with the definition of mission science objectives and cost constraint. An observational sequence and sensor subsystem are then designed. This sensor subsystem in turn becomes the design driver for the sciencecraft architecture and hardware subsystems needed to deliver the sensor to its target and return the science data to the earth. Throughout the design process, shared functionality, shared redundancy, and reduced cost are strongly emphasized. The Kuiper Express will be launched using a Delta vehicle and will use solar electric propulsion to add velocity and shape its trajectory in the inner Solar System, executing two earth gravity-assist flybys. It will also execute flybys of main belt asteroids, Mars, Uranus, and Neptune/Triton en route to its target in the Kuiper belt, where it will arrive about ten years after launch. It will use no nuclear power. The surface constituents and morphology of the objects visited will be measured and their atmospheres will be characterized. The cost of the detailed design, fabrication, and launch of the Kuiper

  12. Distant Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Allen, R. Lynne; Bernstein, Gary; Malhotra, Renu

    2001-02-01

    Kuiper Belt Object surveys indicate a lack of objects with semi- major axis a⪆50 AU in low eccentricity, low inclination orbits. This presents a problem for the simplest theories of Kuiper Belt evolution, which predict a dense, primordial outer Kuiper Belt. A possible solution is that the outer Belt is very dynamically cold, appearing as a razor-thin plane on the sky. If this disk was inclined only 0.5° from the ecliptic, present surveys could fail to detect it since the deep surveys (limiting magnitude R~26) lack sufficient sky coverage and the shallow surveys (limiting mag R~24.4) lack sufficient depth to see small (radius ⪉130 km) objects beyond 50 AU. If this cold, dense disk were to cross a Mosaic field with a limiting magnitude R=25.8, we would expect to see at least 15 distant KBOs. By observing strategically placed large fields we could detect any cold, dense distant disk inclined at up to 0.7° from the invariable plane. This would place a strong constraint on the location of a cold, dense outer Kuiper Belt.

  13. 49 CFR 179.100-20 - Stamping.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... outside heads as follows: Example of required stamping Specification DOT-105A100W Material ASTM A 516 Cladding material (if any) ASTM A240-304 Tank builder's initials Clad Date of original test ABC...

  14. 20 CFR 638.100 - General.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR JOB CORPS PROGRAM UNDER TITLE IV-B OF THE JOB TRAINING PARTNERSHIP ACT Purpose and Scope § 638.100 General. (a) Purpose and scope. The... Job Corps program, authorized under title IV-B of the Job Training Partnership Act (Act). Job Corps...

  15. 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...

  16. 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...

  17. 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...

  18. 20 CFR 411.100 - Scope.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...' 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...

  19. 20 CFR 411.100 - Scope.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...' 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...

  20. 31 CFR 20.100 - What does this part do?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 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...

  1. 38 CFR 20.100 - Rule 100. Name, business hours, and mailing address of the Board.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Rule 100. Name, business hours, and mailing address of the Board. 20.100 Section 20.100 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) BOARD OF VETERANS' APPEALS: RULES OF PRACTICE The Board §...

  2. 20 CFR 664.100 - What is the youth council?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... section 117(h) and 20 CFR 661.335 and 661.340. (b) The purpose of the youth council is to provide... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false What is the youth council? 664.100 Section...) YOUTH ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Youth Councils § 664.100 What is...

  3. 20 CFR 664.100 - What is the youth council?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... section 117(h) and 20 CFR 661.335 and 661.340. (b) The purpose of the youth council is to provide... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false What is the youth council? 664.100 Section...) YOUTH ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Youth Councils § 664.100 What is...

  4. 20 CFR 664.100 - What is the youth council?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... section 117(h) and 20 CFR 661.335 and 661.340. (b) The purpose of the youth council is to provide... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false What is the youth council? 664.100 Section...) YOUTH ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Youth Councils § 664.100 What is...

  5. 20 CFR 498.100 - Basis and purpose.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Basis and purpose. 498.100 Section 498.100 Employees' Benefits SOCIAL SECURITY ADMINISTRATION CIVIL MONETARY PENALTIES, ASSESSMENTS AND RECOMMENDED EXCLUSIONS § 498.100 Basis and purpose. (a) Basis. This part implements sections 1129 and 1140 of the...

  6. 20 CFR 498.100 - Basis and purpose.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Basis and purpose. 498.100 Section 498.100 Employees' Benefits SOCIAL SECURITY ADMINISTRATION CIVIL MONETARY PENALTIES, ASSESSMENTS AND RECOMMENDED EXCLUSIONS § 498.100 Basis and purpose. (a) Basis. This part implements sections 1129 and 1140 of the...

  7. 20 CFR 498.100 - Basis and purpose.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Basis and purpose. 498.100 Section 498.100 Employees' Benefits SOCIAL SECURITY ADMINISTRATION CIVIL MONETARY PENALTIES, ASSESSMENTS AND RECOMMENDED EXCLUSIONS § 498.100 Basis and purpose. (a) Basis. This part implements sections 1129 and 1140 of the...

  8. 20 CFR 498.100 - Basis and purpose.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Basis and purpose. 498.100 Section 498.100 Employees' Benefits SOCIAL SECURITY ADMINISTRATION CIVIL MONETARY PENALTIES, ASSESSMENTS AND RECOMMENDED EXCLUSIONS § 498.100 Basis and purpose. (a) Basis. This part implements sections 1129 and 1140 of the...

  9. 20 CFR 498.100 - Basis and purpose.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Basis and purpose. 498.100 Section 498.100 Employees' Benefits SOCIAL SECURITY ADMINISTRATION CIVIL MONETARY PENALTIES, ASSESSMENTS AND RECOMMENDED EXCLUSIONS § 498.100 Basis and purpose. (a) Basis. This part implements sections 1129 and 1140 of the...

  10. 20 CFR 652.100 - Services for veterans.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Services for veterans. 652.100 Section 652.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR ESTABLISHMENT AND FUNCTIONING OF STATE EMPLOYMENT SERVICES Services for Veterans § 652.100 Services for veterans. Services...

  11. 20 CFR 652.100 - Services for veterans.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Services for veterans. 652.100 Section 652.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR ESTABLISHMENT AND FUNCTIONING OF STATE EMPLOYMENT SERVICES Services for Veterans § 652.100 Services for veterans. Services...

  12. 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

  13. 20 CFR 61.100 - General reimbursement provisions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false General reimbursement provisions. 61.100 Section 61.100 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR COMPENSATION FOR INJURY, DISABILITY, DEATH, OR ENEMY DETENTION OF EMPLOYEES OF CONTRACTORS WITH THE...

  14. Euclid Asteroseismology and Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Gould, Andrew; Huber, Daniel; Stello, Dennis

    2016-02-01

    Euclid, which is primarily a dark-energy/cosmology mission, may have a microlensing component, consisting of perhaps four dedicated one-month campaigns aimed at the Galactic bulge. We show that such a program would yield excellent auxilliary science, including asteroseismology detections for about 100,000 giant stars, and detection of about 1000 Kuiper Belt Objects (KBOs), down to 2--2.5 mag below the observed break in the KBO luminosity function at I˜ 26. For the 400 KBOs below the break, Euclid will measure accurate orbits, with fractional period errors ≲ 2.5%.

  15. 20 CFR 664.100 - What is the youth council?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... success of youth in the labor market. (WIA sec. 117(h).) ... 664.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR YOUTH...) and 20 CFR 661.335 and 661.340. (b) The purpose of the youth council is to provide expertise in...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Purpose and Coverage § 20.100 What does this part do? This part carries out the portion of the Drug-Free Workplace Act of 1988 (41 U.S.C. 701 et seq... agreements and other financial assistance awards, as a matter of Federal Government policy....

  17. 31 CFR 20.100 - What does this part do?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Purpose and Coverage § 20.100 What does this part do? This part carries out the portion of the Drug-Free Workplace Act of 1988 (41 U.S.C. 701 et seq... agreements and other financial assistance awards, as a matter of Federal Government policy....

  18. 31 CFR 20.100 - What does this part do?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Purpose and Coverage § 20.100 What does this part do? This part carries out the portion of the Drug-Free Workplace Act of 1988 (41 U.S.C. 701 et seq... agreements and other financial assistance awards, as a matter of Federal Government policy....

  19. 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.

  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. PMID:11961547

  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. The Kuiper Belt Recovery Program

    NASA Astrophysics Data System (ADS)

    Parker, Joel; Allen, Lynne; Gladman, Brett; Hergenrother, Carl; Kavelaars, J. J.

    2002-08-01

    The number of known Kuiper belt objects continues to increase each year, and the rate will soon accelerate significantly due to new and continuing wide-field projects dedicated to the discovery of these outer solar system bodies. A focused program dedicated to the recovery of these objects is necessary if the considerable effort and observing time spent on the discoveries are to have any long-term scientific significance. Our project explicitly addresses that need by providing reliable recovery observations (integrated with a CFHT survey we are conducting) at sufficient frequency to keep pace with the discoveries that need follow-up, as well as to provide photometric data for use in analysis of Kuiper belt physical properties such as size distribution, dynamics, formation, and structure. This NOAO proposal requests two KPNO observing runs at the end of semester 2002B to continue our successful recovery project. Our measurements will assure that the calculated orbits are determined well enough for future photometric and spectroscopic observations for physical studies. We have an efficient and proven pipeline to: find objects, provide sub- arcsecond absolute astrometry and calibrated photometry, determine orbits, and report results to the Minor Planet Center to refine the orbital elements.

  3. The Kuiper Belt Recovery Program

    NASA Astrophysics Data System (ADS)

    Parker, Joel; Allen, Lynne; Gladman, Brett; Grav, Tommy; Hergenrother, Carl; Holman, Matthew; Kavelaars, J. J.

    2002-02-01

    The number of known Kuiper belt related objects is increasing at an accelerated rate due to many wide-field projects dedicated to the discovery of these outer solar system bodies. A focused and dedicated recovery program is necessary and urgent if the considerable effort and observing time spent on the discoveries are to have any long-term scientific significance. This project (integrated with a CFHT survey we are conducting) will address that need by providing reliable recovery observations at sufficient frequency to keep pace with the discoveries that need follow-up, as well as to provide photometric data for use in analysis of Kuiper belt physical properties such as size distribution, dynamics, formation, and structure. Our measurements will assure that the calculated orbits are determined well enough for future photometric and spectroscopic observations for physical studies. We have an efficient and proven pipeline to: find objects, provide sub-arcsecond absolute astrometry and calibrated photometry, determine orbits, and report results to the Minor Planet Center to refine the orbital elements.

  4. 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.

  5. Collisions in the Kuiper belt

    NASA Astrophysics Data System (ADS)

    Brown, Michael

    2007-07-01

    For most of the 15 year history of observations of Kuiper belt objects, it has been speculated that impacts must have played a major role in shaping the physical and chemical characteristics of these objects, yet little direct evidence of the effects of such impacts has been seen. The past 18 months, however, have seen an explosion of major new discoveries giving some of the first insights into the influence of this critical process. From a diversity of observations we have been led to the hypotheses that: {1} satellite-forming impacts must have been common in the Kuiper belt; {2} such impacts led to significant chemical modification; and {3} the outcomes of these impacts are sufficiently predictable that we can now find and study these impact-derived systems by the chemical and physical attributes of both the satellites and the primaries. If our picture is correct, we now have in hand for the first time a set of incredibly powerful tools to study the frequency and outcome of collisions in the outer solar system. Here we propose three linked projects that would answer questions critical to the multiple prongs of our hypothesis. In these projects we will study the chemical effects of collisions through spectrophotometric observations of collisionally formed satellites and through the search for additional satellites around primaries with potential impact signatures, and we will study the physical effects of impacts through the examination of tidal evolution in proposed impact systems. The intensive HST program that we propose here will allow us to fully test our new hypotheses and will provide the ability to obtain the first extensive insights into outer solar system impact processes.

  6. 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.

  7. 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.

  8. 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,...

  9. 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,...

  10. 20 CFR 653.100 - Purpose and scope of subpart.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 653.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR SERVICES OF THE EMPLOYMENT SERVICE SYSTEM Services for Migrant and Seasonal Farmworkers (MSFWs) § 653.100 Purpose... Employment Service (USES) for counseling, testing, and job and training referral services for migrant...

  11. 20 CFR 653.100 - Purpose and scope of subpart.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... THE EMPLOYMENT SERVICE SYSTEM Services for Migrant and Seasonal Farmworkers (MSFWs) § 653.100 Purpose... Employment Service (USES) for counseling, testing, and job and training referral services for migrant...

  12. 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

  13. 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.

  14. 20 CFR 664.100 - What is the youth council?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) and 20 CFR 661.335 and 661.340. (b) The purpose of the youth council is to provide expertise in youth... incorporate a youth development perspective; (3) Establishing linkages with other organizations serving...

  15. 20 CFR 439.100 - What does this part do?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... out the portion of the Drug-Free Workplace Act of 1988 (41 U.S.C. 701 et seq., as amended) that....100 Employees' Benefits SOCIAL SECURITY ADMINISTRATION GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE... assistance awards, as a matter of Federal Government policy....

  16. 20 CFR 637.100 - Scope and purpose.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... THE JOB TRAINING PARTNERSHIP ACT General Provisions § 637.100 Scope and purpose. (a) This part...-sufficiency, to increase child support payments, and to increase employment and earnings (section 501). (b) This part applies to programs operated with funds under Title V of the Job Training Partnership Act....

  17. 20 CFR 637.100 - Scope and purpose.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... THE JOB TRAINING PARTNERSHIP ACT General Provisions § 637.100 Scope and purpose. (a) This part...-sufficiency, to increase child support payments, and to increase employment and earnings (section 501). (b) This part applies to programs operated with funds under Title V of the Job Training Partnership Act....

  18. 20 CFR 637.100 - Scope and purpose.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... THE JOB TRAINING PARTNERSHIP ACT General Provisions § 637.100 Scope and purpose. (a) This part...-sufficiency, to increase child support payments, and to increase employment and earnings (section 501). (b) This part applies to programs operated with funds under Title V of the Job Training Partnership Act....

  19. 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

  20. 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

  1. Structure of the Atmosphere of Venus up to 110 Kilometers: Preliminary Results from the Four Pioneer Venus Entry Probes.

    PubMed

    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

    1979-02-23

    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 degrees south latitude than at 5 degrees or 60 degrees 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.

  2. 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.

  3. [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. PMID:15754756

  4. [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.

  5. 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.

  6. Conglomeration of Kilometer-sized Planetesimals

    NASA Astrophysics Data System (ADS)

    Shannon, Andrew; Wu, Yanqin; Lithwick, Yoram

    2015-03-01

    We study the efficiency of forming large bodies, starting from a sea of equal-sized planetesimals. This is likely one of the earlier steps of planet formation and relevant for the formation of the asteroid belt, the Kuiper Belt, and extrasolar debris disks. Here we consider the case that the seed planetesimals do not collide frequently enough for collisions to be dynamically important (the collisionless limit), using a newly constructed conglomeration code, and by carefully comparing numerical results with analytical scalings. In the absence of collisional cooling, as large bodies grow by accreting small bodies, the velocity dispersion of the small bodies (u) is increasingly excited. Growth passes from the well-known runaway stage (when u is higher than the big bodies’ hill velocity) to the newly discovered trans-hill stage (when u and big bodies both grow, but u remains at the big bodies’ hill velocity). We find, concurring with the analytical understandings developed by Lithwick, as well as previous numerical studies, that a size spectrum dn/dR\\propto {{R}-4} results, and that the formation efficiency, defined as the mass fraction in bodies much larger than the initial size, is ˜ a few× {{R}⊙ }/a, or ˜ {{10}-3} at the distance of the Kuiper Belt. We argue that this extreme inefficiency invalidates the conventional conglomeration model for the formation of both our Kuiper Belt and extrasolar debris disks. New theories, possibly involving direct gravitational collapse, or strong collisional cooling of small planetesimals, are required.

  7. 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.

  8. 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...

  9. 21 CFR 20.100 - Applicability; cross-reference to other regulations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... this chapter. (19) Data and information submitted for OTC drug review, in § 330.10(a)(2) 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...

  10. 21 CFR 20.100 - Applicability; cross-reference to other regulations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... this chapter. (19) Data and information submitted for OTC drug review, in § 330.10(a)(2) of this... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Applicability; cross-reference to other regulations. 20.100 Section 20.100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND...

  11. 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

  12. 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

  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. 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

  16. 20 CFR 10.0 - What are the provisions of the FECA, in general?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... benefits to volunteers in the Civil Air Patrol (5 U.S.C. 8141), members of the Reserve Officers' Training... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false What are the provisions of the FECA, in general? 10.0 Section 10.0 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT...

  17. 20 CFR 10.0 - What are the provisions of the FECA, in general?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... benefits to volunteers in the Civil Air Patrol (5 U.S.C. 8141), members of the Reserve Officers' Training... 20 Employees' Benefits 1 2014-04-01 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...

  18. 20 CFR 10.0 - What are the provisions of the FECA, in general?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... benefits to volunteers in the Civil Air Patrol (5 U.S.C. 8141), members of the Reserve Officers' Training... 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...

  19. 20 CFR 10.0 - What are the provisions of the FECA, in general?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... benefits to volunteers in the Civil Air Patrol (5 U.S.C. 8141), members of the Reserve Officers' Training... 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...

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

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... benefits to volunteers in the Civil Air Patrol (5 U.S.C. 8141), members of the Reserve Officers' Training... 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...

  1. 20 CFR 662.100 - What is 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 One-Stop delivery system? 662.100...) DESCRIPTION OF THE ONE-STOP SYSTEM UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT General Description of the One-Stop Delivery System § 662.100 What is the One-Stop delivery system? (a) In general, the...

  2. 20 CFR 662.100 - What is 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 One-Stop delivery system? 662.100...) DESCRIPTION OF THE ONE-STOP SYSTEM UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT General Description of the One-Stop Delivery System § 662.100 What is the One-Stop delivery system? (a) In general, the...

  3. 20 CFR 662.100 - What is 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 One-Stop delivery system? 662.100... DESCRIPTION OF THE ONE-STOP SYSTEM UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT General Description of the One-Stop Delivery System § 662.100 What is the One-Stop delivery system? (a) In general, the...

  4. 20 CFR 662.100 - What is 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 One-Stop delivery system? 662.100...) DESCRIPTION OF THE ONE-STOP SYSTEM UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT General Description of the One-Stop Delivery System § 662.100 What is the One-Stop delivery system? (a) In general, the...

  5. 20 CFR 661.100 - What is the workforce investment system?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What is the workforce investment system? 661.100 Section 661.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR..., dislocated workers, youth, incumbent workers, new entrants to the workforce, veterans, persons...

  6. 20 CFR 667.100 - When do Workforce Investment Act grant funds become available?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false When do Workforce Investment Act grant funds become available? 667.100 Section 667.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION.... (b) Youth fund availability. Fiscal year appropriations for a program year's youth...

  7. 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...

  8. 20 CFR 10.100 - How and when is a notice of traumatic injury filed?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true 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...

  9. 20 CFR 10.100 - How and when is a notice of traumatic injury filed?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 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...

  10. 20 CFR 667.100 - When do Workforce Investment Act grant funds become available?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false When do Workforce Investment Act grant funds become available? 667.100 Section 667.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION... April 1 of the fiscal year for which the appropriation is made....

  11. 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... LINES DOMESTIC AND FOREIGN VOYAGES BY SEA Freeboards § 42.20-8 Flooding standard: Type “B” vessel, 100...-11 as applied to the following flooding standards: (1) If the vessel is 225 meters (738 feet) or...

  12. 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.

  13. 46 CFR 42.20-8 - Flooding standard: Type “B” vessel, 100 percent reduction.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Flooding standard: Type âBâ vessel, 100 percent... LINES DOMESTIC AND FOREIGN VOYAGES BY SEA Freeboards § 42.20-8 Flooding standard: Type “B” vessel, 100...-11 as applied to the following flooding standards: (1) If the vessel is 225 meters (738 feet) or...

  14. 46 CFR 42.20-8 - Flooding standard: Type “B” vessel, 100 percent reduction.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Flooding standard: Type âBâ vessel, 100 percent... LINES DOMESTIC AND FOREIGN VOYAGES BY SEA Freeboards § 42.20-8 Flooding standard: Type “B” vessel, 100...-11 as applied to the following flooding standards: (1) If the vessel is 225 meters (738 feet) or...

  15. 46 CFR 42.20-8 - Flooding standard: Type “B” vessel, 100 percent reduction.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Flooding standard: Type âBâ vessel, 100 percent... LINES DOMESTIC AND FOREIGN VOYAGES BY SEA Freeboards § 42.20-8 Flooding standard: Type “B” vessel, 100...-11 as applied to the following flooding standards: (1) If the vessel is 225 meters (738 feet) or...

  16. 46 CFR 42.20-8 - Flooding standard: Type “B” vessel, 100 percent reduction.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Flooding standard: Type âBâ vessel, 100 percent... LINES DOMESTIC AND FOREIGN VOYAGES BY SEA Freeboards § 42.20-8 Flooding standard: Type “B” vessel, 100...-11 as applied to the following flooding standards: (1) If the vessel is 225 meters (738 feet) or...

  17. 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... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What is the One-Stop delivery system? 662.100 Section 662.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF...

  18. 20 CFR 220.100 - Evaluation of disability for any regular employment.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... the Social Security Administration and as amended from time to time (20 CFR part 404, subpart P... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Evaluation of disability for any regular... RAILROAD RETIREMENT ACT DETERMINING DISABILITY Evaluation of Disability § 220.100 Evaluation of...

  19. 20 CFR 220.100 - Evaluation of disability for any regular employment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... the Social Security Administration and as amended from time to time (20 CFR part 404, subpart P... 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...

  20. 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.

  1. Formation of Kuiper Belt Binaries by Gravitational Collapse

    NASA Astrophysics Data System (ADS)

    Nesvorny, David; Youdin, A. N.; Richardson, D. C.

    2010-10-01

    A large fraction of 100-km-class low-inclination objects in the classical Kuiper Belt (KB) are binaries with comparable mass and wide separation of components. A favored model for their formation was capture during the coagulation growth of bodies in the early KB. Instead, recent studies suggested that large, 100-km and larger 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 QW322 and multiples such as (47171) 1999 TC36. Notably, the gravitational collapse is capable of producing 100% binary fraction for a wide range of the swarm's initial angular momentum values. The binary components have similar masses ( 80% have the secondary-over-primary radius ratio >0.7) and their separation ranges from 1,000 to 100,000 km. The binary orbits have eccentricities from e=0 to 1, with the majority having e<0.6. The model inclinations are consistent with the observed general preference for prograde binary orbits. 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.

  2. 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

  3. 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

  4. 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

  5. 25 CFR 20.100 - What definitions clarify the meaning of the provisions of this part?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... SERVICES FINANCIAL ASSISTANCE AND SOCIAL SERVICES PROGRAMS Definitions, Purpose and Policy § 20.100 What... individual by or on whose behalf an application for financial assistance and/or social services has been made... financial assistance or social services. Assistant Secretary means the Assistant Secretary—Indian...

  6. 25 CFR 20.100 - What definitions clarify the meaning of the provisions of this part?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... SERVICES FINANCIAL ASSISTANCE AND SOCIAL SERVICES PROGRAMS Definitions, Purpose and Policy § 20.100 What... individual by or on whose behalf an application for financial assistance and/or social services has been made... financial assistance or social services. Assistant Secretary means the Assistant Secretary—Indian...

  7. 20 CFR 402.100 - Exemption six: Clearly unwarranted invasion of personal privacy.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Exemption six: Clearly unwarranted invasion... AVAILABILITY OF INFORMATION AND RECORDS TO THE PUBLIC § 402.100 Exemption six: Clearly unwarranted invasion of... mandatory disclosure under Exemption Six. (c) Examples. Some of the information that we frequently...

  8. 20 CFR 402.100 - Exemption six: Clearly unwarranted invasion of personal privacy.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Exemption six: Clearly unwarranted invasion... AVAILABILITY OF INFORMATION AND RECORDS TO THE PUBLIC § 402.100 Exemption six: Clearly unwarranted invasion of... mandatory disclosure under Exemption Six. (c) Examples. Some of the information that we frequently...

  9. 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... mandatory disclosure under Exemption Six. (c) Examples. Some of the information that we frequently...

  10. 20 CFR 402.100 - Exemption six: Clearly unwarranted invasion of personal privacy.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Exemption six: Clearly unwarranted invasion... AVAILABILITY OF INFORMATION AND RECORDS TO THE PUBLIC § 402.100 Exemption six: Clearly unwarranted invasion of... mandatory disclosure under Exemption Six. (c) Examples. Some of the information that we frequently...

  11. 20 CFR 402.100 - Exemption six: Clearly unwarranted invasion of personal privacy.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Exemption six: Clearly unwarranted invasion... AVAILABILITY OF INFORMATION AND RECORDS TO THE PUBLIC § 402.100 Exemption six: Clearly unwarranted invasion of... mandatory disclosure under Exemption Six. (c) Examples. Some of the information that we frequently...

  12. 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...

  13. 33 CFR 100.20 - Action on application for event assigned to State regulation by Coast Guard-State agreement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Action on application for event 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...

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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).

  20. Formation of Kuiper Belt Binaries by Gravitational Collapse

    NASA Astrophysics Data System (ADS)

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

    2010-09-01

    A large fraction of ~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, gsim100 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 QW322 and multiples such as (47171) 1999 TC36. Notably, the gravitational collapse is capable of producing ~100% binary fraction for a wide range of the swarm's initial angular momentum values. The binary components have similar masses (~80% have a secondary-over-primary radius ratio >0.7) and their separation ranges from ~1000 to ~100,000 km. The binary orbits have eccentricities from e = 0 to ~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 ~90°, with most cases having i < 50°. The total binary mass represents a characteristic fraction of the collapsing swarm's total initial mass, M tot, suggesting M tot equivalent to that of a radius ~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-Menoetius, and (90) Antiope binary systems.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. The Warped Plane of the Classical Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Chiang, Eugene; Choi, Hyomin

    2008-07-01

    By numerically integrating the orbits of the giant planets and of test particles over a period of four billion years, we follow the evolution of the location of the midplane of the Kuiper belt. The Classical Kuiper belt conforms to a warped sheet that precesses with a 1.9 Myr period. The present-day location of the Kuiper belt plane can be computed using linear secular perturbation theory: the local normal to the plane is given by the theory's forced inclination vector, which is specific to every semimajor axis. The Kuiper belt plane does not coincide with the invariable plane, but deviates from it by up to a few degrees in stable zones. For example, at a semimajor axis of 38 AU, the local Kuiper belt plane has an inclination of 1.9 degrees and a longitude of ascending node of 149.9 degrees when referred to the mean ecliptic and equinox of J2000. At a semimajor axis of 43 AU, the local plane has an inclination of 1.9 degrees and a nodal longitude of 78.3 degrees. Only at infinite semimajor axis does the Kuiper belt plane merge with the invariable plane, whose inclination is 1.6 degrees and nodal longitude is 107.7 degrees. A Classical Kuiper belt object keeps its inclination relative to the Kuiper belt plane nearly constant, even while the plane departs from the trajectory predicted by linear theory. The constancy of relative inclination reflects the undamped amplitude of free oscillation; that is, the homogeneous solution to the forced harmonic oscillator equation retains constant amplitude, even while the inhomogeneous solution cannot be written down accurately because the planetary forcing terms are chaotic. Current observations of Classical Kuiper belt objects are consistent with the plane being warped by the giant planets alone, but the sample size will need to increase by a few times before confirmation exceeds 3σ in confidence. In principle, differences between the theoretically expected plane and the observed plane could be used to infer as yet unseen

  6. 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

  7. 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.

  8. Modes of zonal mean temperature variability 20-100 km from the TIMED/SABER observations

    NASA Astrophysics Data System (ADS)

    Jiang, Y.; Sheng, Z.; Shi, H. Q.

    2014-03-01

    In this study we investigate the spatial variabilities of the zonal mean temperature (20-100 km) from the TIMED (Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics)/SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) satellite using the empirical orthogonal functions (EOFs). After removing the climatological annual mean, the first three EOFs are able to explain 87.0% of temperature variabilities. The primary EOF represents 74.1% of total anomalies and is dominated by the north-south contrast. Patterns in the second and third EOFs are related to the semiannual oscillations (SAO) and mesospheric temperature inversions (MTI), respectively. The quasi-biennial oscillation (QBO) component is also decomposed into the seventh EOF with contributions of 1.2%. Last, we use the first three modes and annual mean temperature to reconstruct the data. The result shows small differences are in low latitude, which increase with latitude in the middle stratosphere and upper mesosphere.

  9. 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, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false Do the core indicators described in 20 CFR... indicators described in 20 CFR 666.100(a)(3) apply to participation in summer employment activities? Yes, the... of performance are met. Program operators can help ensure positive outcomes for youth participants...

  10. 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 described in 20 CFR 666.100(a)(3) apply to participation in summer employment activities? Yes, the...

  11. 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.

  12. A STRONG EXCESS IN THE 20-100 keV EMISSION OF NGC 1365

    SciTech Connect

    Risaliti, G.; Elvis, M.; Fabbiano, G.; Wang, J.; Braito, V.; Laparola, V.; Bianchi, S.; Matt, G.; Maiolino, R.; Reeves, J.; Salvati, M.

    2009-11-01

    We present a new Suzaku observation of the obscured active galactic nucleus in NGC 1365, revealing an unexpected excess of X-rays above 20 keV of at least a factor approx2 with respect to the extrapolation of the best-fitting 3-10 keV model. Additional Swift-BAT and Integral-IBIS observations show that the 20-100 keV is concentrated within approx1.5 arcmin from the center of the galaxy, and is not significantly variable on timescales from days to years. A comparison of this component with the 3-10 keV emission, which is characterized by a rapidly variable absorption, suggests a complex structure of the circumnuclear medium, consisting of at least two distinct components with rather different physical properties, one of which covers >80% of the source with a column density N {sub H} approx 3-4x10{sup 24} cm{sup -2}. An alternative explanation is the presence of a double active nucleus in the center of NGC 1365.

  13. 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

  14. 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

  15. Effects of 20-100 nm particles on liquid clouds in the clean summertime Arctic

    NASA Astrophysics Data System (ADS)

    Leaitch, W. Richard; Korolev, Alexei; Aliabadi, Amir A.; Burkart, Julia; Willis, Megan D.; Abbatt, Jonathan P. D.; Bozem, Heiko; Hoor, Peter; Köllner, Franziska; Schneider, Johannes; Herber, Andreas; Konrad, Christian; Brauner, Ralf

    2016-09-01

    Observations addressing effects of aerosol particles on summertime Arctic clouds are limited. An airborne study, carried out during July 2014 from Resolute Bay, Nunavut, Canada, as part of the Canadian NETCARE project, provides a comprehensive in situ look into some effects of aerosol particles on liquid clouds in the clean environment of the Arctic summer. Median cloud droplet number concentrations (CDNC) from 62 cloud samples are 10 cm-3 for low-altitude cloud (clouds topped below 200 m) and 101 cm-3 for higher-altitude cloud (clouds based above 200 m). The lower activation size of aerosol particles is ≤ 50 nm diameter in about 40 % of the cases. Particles as small as 20 nm activated in the higher-altitude clouds consistent with higher supersaturations (S) for those clouds inferred from comparison of the CDNC with cloud condensation nucleus (CCN) measurements. Over 60 % of the low-altitude cloud samples fall into the CCN-limited regime of Mauritsen et al. (2011), within which increases in CDNC may increase liquid water and warm the surface. These first observations of that CCN-limited regime indicate a positive association of the liquid water content (LWC) and CDNC, but no association of either the CDNC or LWC with aerosol variations. Above the Mauritsen limit, where aerosol indirect cooling may result, changes in particles with diameters from 20 to 100 nm exert a relatively strong influence on the CDNC. Within this exceedingly clean environment, as defined by low carbon monoxide and low concentrations of larger particles, the background CDNC are estimated to range between 16 and 160 cm-3, where higher values are due to activation of particles ≤ 50 nm that likely derive from natural sources. These observations offer the first wide-ranging reference for the aerosol cloud albedo effect in the summertime Arctic.

  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. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

    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 (Cooper et al., Plan. Sp. Sci., 2009) 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.

  19. 20 CFR 1010.100 - What is the purpose and scope of this part?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...? 1010.100 Section 1010.100 Employees' Benefits OFFICE OF THE ASSISTANT SECRETARY FOR VETERANS... Purpose and Definitions § 1010.100 What is the purpose and scope of this part? (a) Part 1010 contains the... in § 1010.210, this part applies to all qualified job training programs....

  20. 20 CFR 660.100 - What is the purpose of title I of the Workforce Investment Act of 1998?

    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 title I of the Workforce Investment Act of 1998? 660.100 Section 660.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) INTRODUCTION TO THE REGULATIONS FOR WORKFORCE INVESTMENT SYSTEMS UNDER TITLE I OF THE WORKFORCE...

  1. 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.

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

    NASA Astrophysics Data System (ADS)

    Holman, Matthew J.; Alcock, Charles; Kenter, Almus T.; Kraft, Ralph P.; Nulsen, Paul; Payne, Matthew John; Vrtilek, Jan M.; Murray, Stephen S.; Murray-Clay, Ruth; Schlichting, Hilke; Brown, Michael E.; Livingston, John H.; Trangsrud, Amy R.; Werner, Michael W.

    2015-01-01

    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 earlysolar 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 upcoming Announcement of Opportunity. The mission is being developed jointly by the Smithsonian Astrophysical Observatory, Jet Propulsion Laboratory, and Ball Aerospace & Technologies, with telescope optics from L-3 Integrated Optical Systems.

  3. 20 CFR 666.100 - What performance indicators must be included in a State's plan?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... who enter unsubsidized employment. (3) For the Youth program, these indicators are: (i) For eligible... training, military service, employment, or qualified apprenticeships. (ii) For eligible youth aged 19... in a State's plan? 666.100 Section 666.100 Employees' Benefits EMPLOYMENT AND TRAINING...

  4. 20 CFR 10.100 - How and when is a notice of traumatic injury filed?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... filed? 10.100 Section 10.100 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF... submitting a notice shall include the Social Security Number (SSN) of the injured employee. (b) For injuries..., of the causal relationship between the disability and the employment (see 5 U.S.C. 8122(b))....

  5. 20 CFR 666.100 - What performance indicators must be included in a State's plan?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... in a State's plan? 666.100 Section 666.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION... States submitting a State Plan under WIA title I, subtitle B must propose expected levels of performance...) Entry into unsubsidized employment; (ii) Retention in unsubsidized employment six months after...

  6. 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 .

  7. 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.

  8. 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.

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

    PubMed

    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.

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

    PubMed

    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. PMID:15637267

  11. 25 CFR 20.100 - What definitions clarify the meaning of the provisions of this part?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... non-medical personal care and supervision due to advanced age, infirmity, physical condition or mental... threat to life, safety, or health as specified in §§ 20.327 and 20.328. Emergency means a situation where... standards when the parent or guardian is unable to resolve the issues that require out-of-home placement...

  12. 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.

  13. 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.

  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. 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.

  16. A binary system in the Kuiper Belt: 1998_WW31

    NASA Astrophysics Data System (ADS)

    Veillet, Christian

    2002-07-01

    1998_WW31 is the first Kuiper Belt Object, outside the pair Pluto/Charon, to be discovered as a binary object. Though only preliminary results are available from two orbits of HST DDT observation when this proposal is submitted, the pair exhibits a very high eccentricity {larger than 0.5} and a period of 570 days. The purpose of this proposal is to complete the monitoring of the pair on a full orbit, up to February 2003. Monitoring will then have to cease {Sun too close}. The binarity of an asteroid allows the determination of the total mass of the system and provides important information on the past Kuiper Belt environment {formation/collisions/capture processes}. If size can be obtained from albedo determination, the mass will give the density, a key parameter for any study of the origin and evolution of the Kuiper Belt. Hubble's unparalleled resolution provides the unique way to acquire observations of the pair good enough to access the physical characteristics of this system with a high degree of confidence, as the high eccentricity of the orbit keeps the two components less than 1 arc-second apart for most of the orbit. The observations would be made public immediately to allow the continuation of the education program offering to follow the pair on a regular basis to illustrate the prediction/verification iterative process of science and the direct use of simple laws for the determination of key parameters.

  17. 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

    ... Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR YOUTH ACTIVITIES UNDER TITLE... described in 20 CFR 666.100(a)(3) apply to participation in summer employment activities? Yes, the summer employment opportunities element is one of a number of activities authorized by the WIA youth program....

  18. Energetics of vertical kilometer foot races; is steeper cheaper?

    PubMed

    Giovanelli, Nicola; Ortiz, Amanda Louise Ryan; Henninger, Keely; Kram, Rodger

    2016-02-01

    Vertical kilometer foot races consist of a 1,000-m elevation gain in <5,000 m of overall distance, and the inclines of the fastest courses are ∼30°. Previous uphill locomotion studies have focused on much shallower angles. We aimed to quantify the metabolic costs of walking and running on very steep angles and to biomechanically distinguish walking from running. Fifteen runners (10 male, 5 female, 32.9 ± 7.5 yr, 1.75 ± 0.09 m, 64.3 ± 9.1 kg) walked and ran for 5 min at seven different angles (9.4, 15.8, 20.4, 24.8, 30.0, 35.0, and 39.2°) all at a fixed vertical velocity (0.35 m/s). We measured the metabolic rates and calculated the vertical costs of walking (Cwvert) and running (Crvert). Using video analysis, we determined stride frequency, stride length, and duty factor (fraction of stride that each foot is in ground contact). At all angles other than 9.4°, Cwvert was cheaper than Crvert (average -8.45 ± 1.05%; P < 0.001). Further, broad minima for both Cwvert and Crvert existed between 20.4 and 35.0° (average Cwvert 44.17 ± 0.41 J·kg(-1)·m(-1) and average Crvert 48.46 ± 0.35 J·kg(-1)·m(-1)). At all angles and speeds tested, both walking and running involved having at least one foot on the ground at all times. However, in walking, stride frequency and stride length were ∼28% slower and longer, respectively, than in running. In conclusion, we found that there is a range of angles for which energy expenditure is minimized. At the vertical velocity tested, on inclines steeper than 15.8°, athletes can reduce their energy expenditure by walking rather than running. PMID:26607247

  19. 11 CFR 100.24 - Federal election activity (2 U.S.C. 431(20)).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... (ii) Generic campaign activity, as defined in 11 CFR 100.25. (iii) Get-out-the-vote activity. (3) A.... The mailer concludes by reminding recipients, “Don't forget to register to vote for X by October 1st... donations, and concludes by reminding listeners, “Don't forget to register to vote.” (3)...

  20. 11 CFR 100.24 - Federal election activity (2 U.S.C. 431(20)).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... (ii) Generic campaign activity, as defined in 11 CFR 100.25. (iii) Get-out-the-vote activity. (3) A.... The mailer concludes by reminding recipients, “Don't forget to register to vote for X by October 1st... donations, and concludes by reminding listeners, “Don't forget to register to vote.” (3)...

  1. 11 CFR 100.24 - Federal election activity (2 U.S.C. 431(20)).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... (ii) Generic campaign activity, as defined in 11 CFR 100.25. (iii) Get-out-the-vote activity. (3) A...-recorded telephone calls, phone banks and messaging such as SMS and MMS), or by any other means; (B... calls, phone banks and messaging such as SMS and MMS), or by any other means; (B) Informing...

  2. 11 CFR 100.24 - Federal election activity (2 U.S.C. 431(20)).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... (ii) Generic campaign activity, as defined in 11 CFR 100.25. (iii) Get-out-the-vote activity. (3) A...-recorded telephone calls, phone banks and messaging such as SMS and MMS), or by any other means; (B... calls, phone banks and messaging such as SMS and MMS), or by any other means; (B) Informing...

  3. 20 CFR 628.100 - Scope and purpose of part 628.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... employability. (c) Title II-B Summer Youth Employment and Training programs are to provide eligible youth with... completion or enrollment in alternative school programs; to increase the employment and earnings of youth; to... Section 628.100 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR...

  4. 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..., and the prohibitions on public service employment, relocation assistance, displacement, and employment... levels. (f) Subpart F establishes the procedures that apply to the filing, handling, and review...

  5. 11 CFR 100.24 - Federal election activity (2 U.S.C. 431(20)).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... defined in 11 CFR 100.25. (iii) Get-out-the-vote activity. (3) A public communication that refers to a... polling places; and (ii) Offering to transport or actually transporting voters to the polls. (4) Voter..., or local committee of a political party for any of the following activities: (1) A...

  6. The Era of Kilometer-Scale Neutrino Detectors

    DOE PAGESBeta

    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. 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

  8. 20 CFR 220.100 - Evaluation of disability for any regular employment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... or mental ability to do basic work activities, the Board will find that the claimant is not disabled... consider factors such as the nature and limiting effects of the impairment(s); the effects of the treatment... the Social Security Administration and as amended from time to time (20 CFR part 404, subpart...

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

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... or mental ability to do basic work activities, the Board will find that the claimant is not disabled... consider factors such as the nature and limiting effects of the impairment(s); the effects of the treatment... the Social Security Administration and as amended from time to time (20 CFR part 404, subpart...

  10. 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...

  11. 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...

  12. 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...

  13. 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.

  14. 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

  15. 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

  16. 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].

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Resonant and Secular Families of the Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Chiang, E. I.; Lovering, J. R.; Millis, R. L.; Buie, M. W.; Wasserman, L. H.; Meech, K. J.

    2003-06-01

    We review ongoing efforts to identify occupants of mean-motion resonances (MMRs) and collisional families in the Edgeworth-Kuiper belt. Direct integrations of trajectories of Kuiper belt objects (KBOs) reveal the 1:1 (Trojan), 5:4, 4:3, 3:2 (Plutino), 5:3, 7:4, 9:5, 2:1 (Twotino), and 5:2 MMRs to be inhabited. Apart from the Trojan, resonant KBOs typically have large orbital eccentricities and inclinations. The observed pattern of resonance occupation is consistent with resonant capture and adiabatic excitation by a migratory Neptune; however, the dynamically cold initial conditions prior to resonance sweeping that are typically assumed by migration simulations are probably inadequate. Given the dynamically hot residents of the 5:2 MMR and the substantial inclinations observed in all exterior MMRs, a fraction of the primordial belt was likely dynamically pre-heated prior to resonance sweeping. A pre-heated population may have arisen as Neptune gravitationally scattered objects into trans-Neptunian space. The spatial distribution of Twotinos offers a unique diagnostic of Neptune's migration history. The Neptunian Trojan population may rival the Jovian Trojan population, and the former's existence is argued to rule out violent orbital histories for Neptune. Finally, lowest-order secular theory is applied to several hundred non-resonant KBOs with well-measured orbits to update proposals of collisional families. No convincing family is detected.

  3. 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. PMID:17361177

  4. 47 CFR 73.186 - Establishment of effective field at one kilometer.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... kilometer. 73.186 Section 73.186 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST... at one kilometer. (a) Section 73.189 provides that certain minimum field strengths are acceptable in... be made on six or more radials, at intervals of approximately 0.2 kilometer up to 3 kilometers...

  5. 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.

  6. 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. PMID:17745405

  7. 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.

  8. A Comparative Study on the Adsorption of Triton X-100 and Tween 20 onto Latexes with Different Interfacial Properties

    PubMed

    Martín-Rodríguez; Cabrerizo-Vílchez; Hidalgo-Álvarez

    1997-03-01

    In this paper we have studied the adsorption of two nonionic surfactants, Triton X-100 and Tween 20 (polyoxyethylene (20) sorbitan monolaurate) onto latexes with different interfacial properties. Four different samples of polystyrene beads were used in this study. A hydrophobic sample was prepared by conventional emulsion polymerization of styrene. Hydrophilic polymer colloids were prepared by the emulsifier-free emulsion copolymerization of styrene and 2-hydroxyethylmethacrylate in different proportions and acrylic acid. In all cases potassium persulfate was used as initiator. In order to consider the mechanism of the adsorption at the different liquid-solid interfaces, adsorption isotherms under different pH and ionic strength conditions were performed. Electrokinetic characterization and colloidal stability of bare hydrophobic and hydrophilic latexes and the surfactant-latex complexes were compared to understand the effect of the nonionic surfactant on the electric double layer structure. The results showed that Tween 20 and Triton X-100 are adsorbed in the same way on surfaces with different polarity but in different amounts. Hydrophobic interaction is the main driving force in the adsorption. The effect of the adsorption on the electrokinetic properties and stability of the latexes was found to be different for hydrophobic and hydrophilic latexes as a consequence of the dissimilar interfacial properties of these two latex samples. PMID:9245323

  9. Kilometer scale telescope collector deployable in a shuttle payload

    NASA Astrophysics Data System (ADS)

    Ditto, Thomas D.

    2004-10-01

    We propose a space telescope that has a diffraction grating as its primary objective element. A membrane grating in the shape of a ribbon could enjoy aperture length above a kilometer. This novel configuration would be particularly useful for very high resolution spectrographic astronomy as required in Doppler shift searches for extra-solar planets due to its very wide aperture in the one dimension used for dispersion and its unprecedented spectral resolving power. Rolls can be stowed in the payload bay for Shuttle delivery into orbit, then unfurled and kept flat using inertial guidance from gyroscopes and centrifugal forces. The large primary collector would not require formation flying since the membrane would provide a mechanical tether. We suggest experiments to establish feasibility of the deployment. We also suggest studies for the tensile mechanics and environmental stresses on the device. Our analysis investigates the parameters of surface flatness, membrane thickness, metallic coating conductivity, grating period, groove blaze and depth. We analyze options for fabrication such as roll embossing of multiple-kilometer length membrane substrates. We also consider an evanescent mode grating in a transmission medium which can be formed using methods now commonplace in telecommunication fiber optics.

  10. Characterization of the low-background Hamamatsu R11410- 20 cryogenic PMTs for the RED100 detector

    NASA Astrophysics Data System (ADS)

    Akimov, D. Yu; Bolozdynya, A. I.; Efremenko, Yu V.; Kaplin, V. A.; Khromov, A. V.; Melikyan, Yu A.; Sosnovtsev, V. V.

    2016-02-01

    The RED100 two-phase liquid xenon emission detector for neutrino coherent scattering experiments is equipped with 38 Hamamatsu R11410-20 photomultiplier tubes capable to operate at cryogenic temperatures and made of low background materials. A dedicated characterization procedure has been carried out for each PMT unit to be installed into the detector. The results presented here include single photoelectron analysis, gain curves for a wide range of the bias voltage values, data on dark count rate for 34 PMT samples. Peculiar noise characteristics of selected PMT units are analysed and discussed.

  11. 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.

  12. 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

  13. The color-magnitude distribution of small Kuiper Belt objects

    NASA Astrophysics Data System (ADS)

    Wong, Ian; Brown, Michael E.

    2015-11-01

    Occupying a vast region beyond the ice giants is an extensive swarm of minor bodies known as the Kuiper Belt. Enigmatic in their formation, composition, and evolution, these Kuiper Belt objects (KBOs) lie at the intersection of many of the most important topics in planetary science. Improved instruments and large-scale surveys have revealed a complex dynamical picture of the Kuiper Belt. Meanwhile, photometric studies have indicated that small KBOs display a wide range of colors, which may reflect a chemically diverse initial accretion environment and provide important clues to constraining the surface compositions of these objects. Notably, some recent work has shown evidence for bimodality in the colors of non-cold classical KBOs, which would have major implications for the formation and subsequent evolution of the entire KBO population. However, these previous color measurements are few and mostly come from targeted observations of known objects. As a consequence, the effect of observational biases cannot be readily removed, preventing one from obtaining an accurate picture of the true color distribution of the KBOs as a whole.We carried out a survey of KBOs using the Hyper Suprime-Cam instrument on the 8.2-meter Subaru telescope. Our observing fields targeted regions away from the ecliptic plane so as to avoid contamination from cold classical KBOs. Each field was imaged in both the g’ and i’ filters, which allowed us to calculate the g’-i’ color of each detected object. We detected more than 500 KBOs over two nights of observation, with absolute magnitudes from H=6 to H=11. Our survey increases the number of KBOs fainter than H=8 with known colors by more than an order of magnitude. We find that the distribution of colors demonstrates a robust bimodality across the entire observed range of KBO sizes, from which we can categorize individual objects into two color sub-populations -- the red and very-red KBOs. We present the very first analysis of the

  14. Photographer: JPL P-21752 BW Range: 1.2 million kilometers This image of Europa shows detail about

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Photographer: JPL P-21752 BW Range: 1.2 million kilometers This image of Europa shows detail about 20 kilometers across and is somewhat higher resolution than the best Voyager 1 image. The part of Europa shown is the hemisphere that will be viewed at even higher resolution during another Voyager 2 encounter with Europa. Color reconstruction in this image was slightly enhanced to bring out detail in the complicated mottled region on the west limb, containing some of the linear fracture-like features discovered by Voyager 1. The regions in the north and south polar areas which appear bluish in this version are in fact white.

  15. 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.

  16. 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.

  17. Explaining the Kuiper Belt with a Jumping Planet

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-09-01

    A feature of the Kuiper Belt known as the kernel has yet to be adequately explained by solar system formation models. In a recent study, a theorist at the Southwest Research Institute proposes a new explanation for how Neptune arrived at its current orbit and how this planets migration in the early years of the solar system might have created the kernel.Orbital JumpThe kernel is a concentration of orbits within the Kuiper Belt that all have semimajor axes of roughly a 44 AU, low eccentricities, and low inclinations. How this collection of objects formed and why they exist where they do is difficult to explain with current models, however. Kernel objects arent in resonance with any of the larger bodies, so why are they concentrated at that specific distance? In this study, David Nesvorn proposes that the kernel resulted from Neptunes outward migration through the solar system.In the currently favored model of our solar systems formation, the outermost gas giant planets formed closer to the Sun and then migrated out to their current locations. Nesvorn ran a series of simulations of this migration to test the theory that a discontinuity in Neptunes movement outward i.e., a sudden jump in the planets orbital distance could explain the presence of the Kuiper Belts kernel.Results from a previous study, in which the authors evolved the four gas giant planets plus a fifth giant planet (blue) initially on an orbit between Saturn and Uranus. At 18.3 Myr, a close encounter with the fifth planet causes Neptunes orbit (pink) to jump outwards by ~0.4 AU, and the fifth planet is then ejected from the solar system by Jupiter. [Nesvorn 2015]Resonant PopulationNesvorn was successful in finding a model that reproduced the kernel, as well as other observed features of the solar system today. In his model, Neptune began its journey closer to the Sun, at a distance of roughly 24 AU, and it migrated fairly rapidly outward to about 28 AU. As it traveled, it swept up bodies in the outer

  18. 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.

  19. An exploration of the Kozai resonance in the Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Wan, X.-S.; Huang, T.-Y.

    2007-05-01

    The Kozai resonance of Kuiper Belt objects is explored using a model of a circular-restricted three-body problem. We use an analytical approach to find the topological structure of the plane of the eccentricity and the argument of perihelion. We find that objects inside the 2:3 and 1:2 resonances can be inside the Kozai resonance, with their arguments of perihelion ω librating around 90° or 270°. This is consistent with the fact that Pluto is inside both the 2:3 resonance and the Kozai resonance. Furthermore, objects outside the mean-motion resonances are also found to be inside the Kozai resonance. We discover that there are stable equilibrium points of ω at 90° and 270°, but not at 0° and 180° as was shown in the work of Thomas & Morbidelli. To verify our results, numerical experiments are carried out with various longitudes of the node and mean anomalies. In these experiments, some test particles are found to be in the Kozai resonance around 90° for one billion years, and the libration amplitudes of their arguments of perihelion are small. This is in agreement with our analytical results. No particles are found to stay inside the Kozai resonance around ω = 0° or 180°, although some particles exist temporarily in the Kozai resonance around ω = 0° or 180°. We conclude that the Kozai resonance around ω = 90° or 270° exists both inside and outside the mean-motion resonance for Kuiper Belt objects.

  20. Shepherding the Kuiper Belt Via Ragged Planet-Migration

    NASA Astrophysics Data System (ADS)

    Hahn, J.; Malhotra, R.

    2000-10-01

    N-body simulations have shown that the orbits of the giant planets would migrate away from each other as they cleared the natal planetesimal disk. The evidence for orbital migration is in the Kuiper Belt; had Neptune's orbit expanded outwards by 8 AU, its sweeping 3:2 resonance would have captured numerous Kuiper Belt Objects (KBOs) and pumped eccentricities up to up to the observed value of e 0.3. Early simulations of this phenomenon effected planet-migration by applying a smooth torque to the planets' orbits (Malhotra 1995). Resonance capture is extremely efficient at depositing nearly all KBOs into eccentric, low-inclination, resonant orbits. However these models are not in full agreement with observations showing that about a third of all known KBOs reside in the Classical Disk which lies between Neptune's 2:1 and 3:2. However it should be recognized that planet-migration is driven by the stochastic scatterings of planetesimals at the planets. To mimic this, we add some random `jitter' to the planet-migration torque. This causes Neptune's orbit to dance to-and-fro as it expands. When sufficient jitter is applied, the resonance capture efficiency is reduced to 50 which allows some KBOs to slip through the advancing 2:1. These bodies enter the Classical disk with eccentricities of e 0.1, which is comparable to the observed e. Jitter also increases the KBO inclinations. We also suspect that the observed underabundance of KBOs at the 2:1 resonance (and beyond) is due to a radial gradient in the KBO size-distribution, namely, that smaller KBOs formed at greater distances from the Sun.

  1. 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.

  2. 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

    ... partners described in 20 CFR part 662. Consistent with those provisions: (1) Core services for adults and... worker programs in the One-Stop delivery system? 663.100 Section 663.100 Employees' Benefits EMPLOYMENT... the One-Stop Delivery System § 663.100 What is the role of the adult and dislocated worker programs...

  3. 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

    ... partners described in 20 CFR part 662. Consistent with those provisions: (1) Core services for adults and... worker programs in the One-Stop delivery system? 663.100 Section 663.100 Employees' Benefits EMPLOYMENT... the One-Stop Delivery System § 663.100 What is the role of the adult and dislocated worker programs...

  4. 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

    ... partners described in 20 CFR part 662. Consistent with those provisions: (1) Core services for adults and... worker programs in the One-Stop delivery system? 663.100 Section 663.100 Employees' Benefits EMPLOYMENT... the One-Stop Delivery System § 663.100 What is the role of the adult and dislocated worker programs...

  5. 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.

  6. 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.

  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. The Allen Telescope Array as Square Kilometer Array Pathfinder

    NASA Astrophysics Data System (ADS)

    Bower, Geoffrey C.

    2007-12-01

    The Allen Telescope Array (ATA) is a new radio interferometer that has begun scientific operations in 2007. Many of the technologies, techniques, and observing modes developed for the ATA are directly applicable to the Square Kilometer Array (SKA). The ATA is a pioneer of the LNSD, which refers to a large number (LN) of small diameter (SD) dishes to create the array. This concept underlies nearly all SKA designs. Other relevant technologies are the offset Gregorian ATA antenna, the ATA wideband log periodic feed, transport of broadband data over fiber optic cables, and flexible digital signal processing electronics. The small dishes of the ATA gives it extraordinary wide-field imaging and survey capability but also require new solutions for calibration and imaging. Real time imaging, rapid response to transients, and thinking telescope technology are also under development. Finally, the ATA is developing commensal observing modes, which enable multiple simultaneous science programs, such as SETI, transient surveys, and HI surveys. Opportunities exist for community members to perform scientific investigations as well as develop techniques and technology for the SKA through use of the ATA.

  9. 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

  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. 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. PMID:26601169

  13. 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.

  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. 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.

  16. Spitzer Thermal Radiometry of Kuiper Belt Objects and Centaurs

    NASA Astrophysics Data System (ADS)

    Stansberry, John; Mueller, Michael; Cruikshank, Dale; Grundy, Will; Noll, Keith; Spencer, John; Trilling, David

    2006-05-01

    About 10 Kuiper Belt Objects (KBOs) have been detected at both 24 and 70um with Spitzer at high enough signal-to-noise ratio (SNR) to allow determinations of their of their albedos and diameters. While these physical parameters can be estimated from a detection at a single thermal wavelength, they are then subject to large uncertainties stemming from the assumed model for the temperature distribution on the surface. A two-color thermal detection eliminates most of the model uncertainty, and the accuracy of the derived parameters is then limited primarily by measurement and calibration errors. An added benefit of a two-color detection is that it yields some information about the temperature distribution, and therefore about the thermal parameter (or thermal inertia, if the rotation period is known) of the surface materials. We propose to use MIPS to detect 8 KBOs and 8 Centaurs at both 24 and 70um, at SNR > 5 in both bands. We base our predictions of their thermal emission, our sensitivity estimates, and our observing strategy on our past observations of KBOs with Spitzer. Our sample size is chosen to double the sample of both KBOs and Centaurs with two-color data, significantly improving our knowledge of their physical parameters, and providing enough objects to allow us to begin to look for trends in albedo vs. size and color.

  17. 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.

  18. 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.

  19. 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.

  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

    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.

  2. 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.

  3. 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.

  4. WFIRST Ultra-Precise Astrometry I: Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Gould, Andrew

    2014-12-01

    I show that the WFIRST microlensing survey will enable detection and precision orbit determination of Kuiper Belt Objects (KBOs) down to H_{vega}=28.2 over an effective area of &sim 17 deg^2. Typical fractional period errors will be ˜ 1.5%× 10^{0.4(H-28.2)} with similar errors in other parameters for roughly 5000 KBOs. Binary companions to detected KBOs can be detected to even fainter limits, H_{vega}=29, corresponding to R˜ 30.5 and effective diameters D˜ 7 km. For KBOs H˜ 23, binary companions can be found with separations down to 10 mas. This will provide an unprecedented probe of orbital resonance and KBO mass measurements. More than a thousand stellar occultations by KBOs can be combined to determine the mean size as a function of KBO magnitude down to H˜ 25. Current ground-based microlensing surveys can make a significant start on finding and characterizing KBOs using existing and soon-to-be-acquired data.

  5. 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.

  6. 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 CFR part 662. Consistent with those provisions: (1) Core services for adults and dislocated... 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...

  7. Fabrication and properties of kilometer level, Nb reinforced, 6 filamentary MgB2 wires

    NASA Astrophysics Data System (ADS)

    Li, C. S.; Yan, G.; Wang, Q. Y.; Jiao, G. F.; Sulpice, A.; Yang, F.; Xiong, X. M.; Liu, G. Q.; Feng, J. Q.; Feng, Y.; Zhang, P. X.

    2013-11-01

    Kilometer level 6 + 1 filamentary MgB2 wires sheathed with Nb/Cu composite tube was fabricated by in situ powder-in-tube (PIT) method, nonferromagnetic Nb was employed as the centre reinforced materials. There is no any annealing in the whole fabrication process due to the excellent ductility of Nb/Cu based tube. The (Mg, B)/Nb/Cu composite wire was fabricated to the target size of 1.4 mm in diameter and heat treated at 680 °C for 2 h in a vacuum furnace. Microstructure, superconductivity, mechanical properties and homogeneity of critical current were measured respectively. The transport engineering critical current density (Jce) reaches 2.5 × 104 A/cm2 at 20 K, 1 T. The results show a good potential to fabricate high performance MgB2 wires at ambient pressure for practical application.

  8. 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.

  9. 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

    ... 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 training activities for adults and dislocated workers, as described in WIA section 134(a), and Statewide...

  10. 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.

  11. Translating aboveground cosmic-ray neutron intensity to high-frequency soil moisture profiles at sub-kilometer scale

    NASA Astrophysics Data System (ADS)

    Rosolem, R.; Hoar, T.; Arellano, A.; Anderson, J. L.; Shuttleworth, W. J.; Zeng, X.; Franz, T. E.

    2014-11-01

    Above-ground cosmic-ray neutron measurements provide an opportunity to infer soil moisture at the sub-kilometer scale. Initial efforts to assimilate those measurements have shown promise. This study expands such analysis by investigating (1) how the information from aboveground cosmic-ray neutrons can constrain the soil moisture at distinct depths simulated by a land surface model, and (2) how changes in data availability (in terms of retrieval frequency) impact the dynamics of simulated soil moisture profiles. We employ ensemble data assimilation techniques in a "nearly-identical twin" experiment applied at semi-arid shrubland, rainfed agricultural field, and mixed forest biomes in the USA. The performance of the Noah land surface model is compared with and without assimilation of observations at hourly intervals, as well as every 2 days. Synthetic observations of aboveground cosmic-ray neutrons better constrain the soil moisture simulated by Noah in root-zone soil layers (0-100cm), despite the limited measurement depth of the sensor (estimated to be 12-20cm). The ability of Noah to reproduce a "true" soil moisture profile is remarkably good, regardless of the frequency of observations at the semi-arid site. However, soil moisture profiles are better constrained when assimilating synthetic cosmic-ray neutron observations hourly rather than every 2 days at the cropland and mixed forest sites. This indicates potential benefits for hydrometeorological modeling when soil moisture measurements are available at a relatively high frequency. Moreover, differences in summertime meteorological forcing between the semi-arid site and the other two sites may indicate a possible controlling factor to soil moisture dynamics in addition to differences in soil and vegetation properties.

  12. 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.

  13. 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

  14. 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:…

  15. 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}.

  16. 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

    ... established to serve Native American peoples (INA programs) under section 166 of the Workforce Investment Act... Policies § 668.100 What is the purpose of the programs established to serve Native American peoples (INA... training services to Native American peoples and their communities. Services should be provided in...

  17. 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.

  18. Dynamics of the Kuiper belt and the Origin of the Planets

    NASA Astrophysics Data System (ADS)

    Levison, H. F.

    2003-05-01

    A little over 10 years ago, our perception of the Solar System changed drastically with the discovery of the first Kuiper belt object. As the number of known objects increased (it is now well over 500), a picture has emerged which shows a Kuiper belt with two major components: a cold population --made of objects on orbits with inclination i< 4deg -- and a hot population --whose inclinations can be as large as 30deg, and possibly larger. These populations have also been found to have different physical properties. In addition, there is a small population (roughly 10%) of objects trapped in mean motion resonances with Neptune. All of these populations are confined to have semi-major axes within 50AU from the Sun, where the whole Kuiper belt seems to have an abrupt end, even if observational biases are accounted for. In addition, the trans-Neptunian region is the home of the 'scattered disk', which consists of objects with very large semi-major axes, but with perihelia typically less than 40AU. The complex structure in the trans-neptunian region is the result of the early dynamical evolution of the planets and thus it may be possible to put strong constraints on the formation of the planets by studying it. Indeed, just within the last few months a picture has emerged about the late stages of solar system formation that explains much of the Kuiper belt's structure. I will review this picture in this talk.

  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. Radioactive plume from the Three Mile Island accident: xenon-133 in air at a distance of 375 kilometers.

    PubMed

    Wahlen, M; Kunz, C O; Matuszek, J M; Mahoney, W E; Thompson, R C

    1980-02-01

    The transit of an air mass containing radioactive gas released from the Three Mile Island reactor was recorded in Albany, New York, by measuring xenon-133. These measurements provide an evaluation of Three Mile Island effluents to distances greater than 100 kilometers. Two independent techniques identified xenon-133 in ambient air at concentrations as high as 3900 picocuries per cubic meter. The local gamma-ray whole-body dose from the passing radioactivity amounted to 0.004 millirem, or 0.004 percent of the annual dose from natural sources. PMID:7352276

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. Green's function approximation from cross-correlations of 20-100 Hz noise during a tropical storm.

    PubMed

    Brooks, Laura A; Gerstoft, Peter

    2009-02-01

    Approximation of Green's functions through cross-correlation of acoustic signals in the ocean, a method referred to as ocean acoustic interferometry, is potentially useful for estimating parameters in the ocean environment. Travel times of the main propagation paths between hydrophone pairs were estimated from interferometry of ocean noise data that were collected on three L-shaped arrays off the New Jersey coast while Tropical Storm Ernesto passed nearby. Examination of the individual noise spectra and their mutual coherence reveals that the coherently propagating noise is dominated by signals of less than 100 Hz. Several time and frequency noise normalization techniques were applied to the low frequency data in order to determine the effectiveness of each technique for ocean acoustic applications. Travel times corresponding to the envelope peaks of the noise cross-correlation time derivatives of data were extracted from all three arrays, and are shown to be in agreement with the expected direct, surface-reflected, and surface-bottom-reflected interarray hydrophone travel times. The extracted Green's function depends on the propagating noise. The Green's function paths that propagate horizontally are extracted from long distance shipping noise, and during the storm the more vertical paths are extracted from breaking waves.

  7. 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.

  8. 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…

  9. 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.

  10. 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.

  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. 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.

  13. Signatures of Planets: Observations and Modeling of Structure in the Zodiacal Cloud and Kuiper Disk

    NASA Astrophysics Data System (ADS)

    Holmes, E. K.; Dermott, S. F.

    2001-12-01

    There is a possible connection between structure in evolved circumstellar disks and the presence of planets. Asymmetries in such a disk (such as the zodiacal cloud in the inner solar system or the Kuiper disk in the outer solar system) could be diagnostic of planets that would be otherwise undetectable. At least three different types of asymmetries can serve to indicate bodies orbiting a star in a disk: (1) a warp in the plane of symmetry of the disk, (2) an offset in the center of symmetry of the disk with respect to the central star, and (3) density anomalies in the plane of the disk such as dust bands or resonant rings. Structure in the zodiacal cloud, namely the warp and offset of the cloud, are linked to the presence of planets using secular perturbation theory. A Kuiper disk would most likely have a resonant structure, with two concentrations in brightness along the ecliptic longitude. This structure arises because 10-15% of the Kuiper belt objects, the Plutinos, are in the 3:2 mean motion resonance with Neptune (Jewitt 1999, Malhotra 1995). A size-frequency distribution of particles in the Plutino disk based on the percentage of particles that are trapped in the 3:2 resonance is determined by running numerical integrations of particles in Pluto-like orbits. The dynamical evolution of the particles is followed from source to sink with Poynting-Robertson light drag, solar wind drag, radiation pressure, the Lorentz force, neutral interstellar gas drag, and the effects of planetary gravitational perturbations included. In addition, a search is conducted in COBE DIRBE data for far-infrared emission from the Kuiper disk, which is predicted to be, at most, a few percent of the brightness of the zodiacal cloud from COBE upper limits (Dermott et al. 1999, Backman et al. 1995, Teplitz et al. 1999).

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. Conceptual design of electrical balance of plant for advanced battery energy storage facility. Annual report, March 1979. [20-MW, 100 MWh

    SciTech Connect

    1980-01-01

    Large-scale efforts are in progress to develop advanced batteries for utility energy storage systems. Realization of the full benefits available from those systems requires development, not only of the batteries themselves, but also the ac/dc power converter, the bulk power interconnecting equipment, and the peripheral electric balance of plant equipment that integrate the battery/converter into a properly controlled and protected energy system. This study addresses these overall system aspects; although tailored to a 20-MW, 100-MWh lithium/sulfide battery system, the technology and concepts are applicable to any battery energy storage system. 42 figures, 14 tables. (RWR)

  3. Preliminary evaluation of the /sup 235/U(n,f) cross-section from 100 keV to 20 MeV

    SciTech Connect

    Bhat, M.R.

    1983-01-01

    A preliminary evaluation of the fission cross-section of /sup 235/U from 100 keV to 20 MeV is described. Variance-covariance matrices for a number of experimental data sets were constructed and used to evaluate the fission cross-section following a Bayesian procedure. The evaluated fission cross-section is compared with experimental data including the /sup 252/Cf fission neutron spectrum averages and some of the problems encountered in carrying out the fit are discussed.

  4. 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.

  5. 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}.

  6. 700, 100, and 20 hp combustion test facility yearly activity report for the period April 1, 1979 to April 1, 1980

    SciTech Connect

    Not Available

    1980-01-01

    Management and Technical Services Co./ General Electric was awarded the contract to operate, modify and maintain the DOE/PETC 700 hp, 100 hp, and 20 hp Combustion Test Facility. These facilities were designed and built by the Department of Energy at Pittsburgh Energy Technology Center and its ultimate success is the responsibility of DOE/PETC. MATSCO/GE will provide support to assist in the goal of successful operation of this pilot plant facility. The primary objective of the DOE/PETC 700 hp and 100 hp CTF is to establish the practicality of coal oil slurry combustion as a technically, economically and environmentally feasible retrofit technology. The 20 hp CTF is to provide a test bed to evaluate synthetic fuels for its technical feasibility and its effect on the environment. Four series of combustion tests were completed. Coal-oil mixes for all tests were number 6 fuel oil and Pittsburgh Seam Coal. The tests were executed successfully. Operational problems were handled as required without excessive delay of the testing program. Additional studies performed concurrently with the combustion testing included flame studies, stack emissions studies during all tests, standard measurements of equipment wear after each test series and extensive erosion and corrosion analyses of boiler test coupons and the burner section of the fuel train after the 500 h endurance test. Testing activity and required facility modifications were coordinated through Department of Energy personnel.

  7. Seeing Double -- The Discovery of Binaries in the Edgeworth-Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Stephens, Denise

    2007-10-01

    The demotion of Pluto as a planet really started in 1978 with the discovery of its moon Charon. Once it was known to be in a binary system, it was just a matter of time before the determination of Pluto's mass, along with the discovery of other transneptunian objects (TNOs), would lead to its declassification. This example highlights the fact that binary discoveries are critical for determining the mass of TNOs in the Kuiper belt. If we can determine the orbit of a binary system, we can find the mass. An independent measurement of the size of the components then leads to a determination of the bulk density. From the bulk density we can deduce the characteristic composition and structure of these objects. The successful measurement of these fundamental quantities has and will continue to advance our theories on the formation, structure, and evolution of bodies in the outer solar system. This talk focuses on the discovery of binary systems in the Kuiper belt and the current state of our knowledge. To date there are over 50 confirmed binary systems, a number that is an extreme lower limit to the true binary population. In this talk, I'll highlight past and current searches led by Keith Noll (STScI) to find binary systems using the Hubble Space Telescope (HST). My role in this research will be discussed and will lead to a discussion on some of the techniques we are using to identify binary systems at extremely small angular resolutions. Members of our group led by Will Grundy (Lowell Observatory) are calculating orbits for a few of the binary systems, and highlights of his results will be presented. The talk will then conclude with some statistics relating the binary frequency of TNOs to their dynamical classes, and explore what this could imply about the structure and formation of the Kuiper belt.

  8. 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

  9. The evolution of comets in the Oort cloud and Kuiper belt.

    PubMed

    Alan Stern, S

    2003-08-01

    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.

  10. The evolution of comets in the Oort cloud and Kuiper belt.

    PubMed

    Alan Stern, S

    2003-08-01

    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. PMID:12904784

  11. Mid-Infrared Spectroscopy of Mercury from the Kuiper Airborne Observatory

    NASA Astrophysics Data System (ADS)

    Sprague, A. L.; Witteborn, F. C.; Kozlowski, R. W. H.; Wooden, D. H.

    1996-03-01

    We present mid-infrared (5 - 10mic) spectroscopic measurements of the planet Mercury obtained from the Kuiper Airborne Observatory (KAO) using the High Efficiency Infrared Faint Object Grating Spectrograph (HIFOGS). Spectra show features characteristic of plagioclase feldspar that was previously observed near 120 deg mercurian longitude. The spectra also show spectral features that could be interpreted indicative of the presence of pyrrhotite (pyrr). An analysis that fully accounts for the effects of large field of view (FOV), thermal gradients, rough surface and absolute calibration is still underway.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. Searching for a Kuiper-belt flyby target for the New Horizons spacecraft

    NASA Astrophysics Data System (ADS)

    Kavelaars, J.; Spencer, J.; Susan, B.; Borncamp, D.; Buie, M.; Fuentes, C.; Parker, A.; Tholen, D.; Osip, D.

    2014-07-01

    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 (less than 50 km) KBOs. This first flyby of a typical small 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 (spring 2014), however, no known KBOs are reachable by the spacecraft. For the past 4 years we have been conducting a dedicated search for suitable targets, using the Subaru, Magellan and CFH 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. We are now requesting 150 orbits with HST to continue our search to fainter limiting magnitudes. We have discovered dozens of 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.

  17. 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).

  18. 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.

  19. 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. PMID:20559381

  20. ALICE: The Ultraviolet Imaging Spectrograph Aboard the New Horizons Pluto-Kuiper Belt Mission

    NASA Astrophysics Data System (ADS)

    Stern, S. Alan; Slater, David C.; Scherrer, John; Stone, John; Dirks, Greg; Versteeg, Maarten; Davis, Michael; Gladstone, G. Randall; Parker, Joel W.; Young, Leslie A.; Siegmund, Oswald H. W.

    2008-10-01

    The ALICE instrument is a lightweight (4.4 kg), low-power (4.4 watt) imaging spectrograph aboard the New Horizons mission to the Pluto system and the Kuiper Belt. Its primary job is to determine the relative abundances of various species in Pluto’s atmosphere. ALICE will also be used to search for an atmosphere around Pluto’s moon, Charon, as well as the Kuiper Belt Objects (KBOs) that New Horizons is expected to fly by after Pluto-Charon, and it will make UV surface reflectivity measurements of all of these bodies, as well as of Pluto’s smaller moons Nix and Hydra. The instrument incorporates an off-axis telescope feeding a Rowland-circle spectrograph with a 520-1870 Å spectral passband, a spectral point spread function of 3-6 Å FWHM, and an instantaneous spatial field-of-view that is 6 degrees long. Two different input apertures that feed the telescope allow for both airglow and solar occultation observations during the mission. The focal plane detector is an imaging microchannel plate (MCP) double delay-line detector with dual solar-blind opaque photocathodes (KBr and CsI) and a focal surface that matches the instrument’s 15-cm diameter Rowland-circle. In this paper, we describe the instrument in greater detail, including descriptions of its ground calibration and initial in flight performance. New Horizons launched on 19 January 2006.

  1. 1998 SM165: a large Kuiper belt object with an irregular shape.

    PubMed

    Romanishin, W; Tegler, S C; Rettig, T W; Consolmagno, G; Botthof, B

    2001-10-01

    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 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. PMID:11572937

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. Signatures of planets: Observations and modeling of structure in the zodiacal cloud and Kuiper disk

    NASA Astrophysics Data System (ADS)

    Holmes, Elizabeth Katherine

    2002-12-01

    There is a possible connection between structure in evolved circumstellar disks and the presence of planets, our own zodiacal cloud being a proven example. Asymmetries in such a disk could be diagnostic of planets which would be otherwise undetectable. Using COBE DIRBE observations, we link structure in the zodiacal cloud, namely the warp and offset of the cloud, to the presence of planets using secular perturbation theory. In addition, we obtain supplementary ISO observations and determine a scale factor for the data which we apply to calibrate the data to the observed COBE brightness. A Kuiper dust disk will have a resonant structure, with two concentrations in brightness along the ecliptic longitude arising because 10 15% of the Kuiper belt objects are in the 3:2 mean motion resonance with Neptune. We run numerical integrations of particles originating from source bodies trapped in the 3:2 resonance and we determine what percentage of particles remain in the resonance for a variety of particle and source body sizes. The dynamical evolution of the particles is followed from source to sink with Poynting- Robertson light drag, solar wind drag, radiation pressure, the Lorentz force, neutral interstellar gas drag, and the effects of planetary gravitational perturbations included. We then conduct an observational search in the 60 μm COBE data for the Kuiper disk, which is predicted to be, at most, a few percent of the brightness of the zodiacal cloud. By removing emission due to the background zodiacal cloud and the dust bands, we expect to see the trailing/leading signature of Earth's resonant ring. However, when subtracted from the data, we find that none of the empirical background zodiacal cloud models give the residuals predicted by theory. We conclude that a dynamical two-component (both inner and outer) zodiacal cloud model must be created to complete the search. Lastly, we extend our work outside the solar system and obtain upper limits on the flux around ten

  7. Evidence for 115 kilometers of right slip on the san gregorio-hosgri fault trend.

    PubMed

    Graham, S A; Dickinson, W R

    1978-01-13

    The San Gregorio-Hosgri fault trend is a component of the San Andreas fault system on which there may have been about 115 kilometers of post-early Miocene right-lateral strike slip. If so, right slip on the San Andreas and San Gregorio-Hosgri faults accounts for most of the movement between the Pacific and North American plates since mid-Miocene time. Furthermore, the magnitude of right slip on a Paleogene proto-San Andreas fault inferred from the present distribution of granitic basement is reduced considerably when Neogene-Recent San Gregorio-Hosgri right slip is taken into account.

  8. Enhancement of cation diffusion rates across the 410-kilometer discontinuity in Earth's mantle

    PubMed

    Chakraborty; Knoche; Schulze; Rubie; Dobson; Ross; Angel

    1999-01-15

    Rates of cation diffusion (magnesium, iron, and nickel) have been determined in olivine and its high-pressure polymorph, wadsleyite, at 9 to 15 gigapascals and 1100 degrees to 1400 degreesC for compositions that are relevant to Earth's mantle. Diffusion in olivine becomes strongly dependent on composition at high pressure. In wadsleyite, diffusion is one to two orders of magnitude faster than in olivine, depending on temperature. Homogenization of mantle heterogeneities (chemical mixing) and mineral transformations involving a magnesium-iron exchange will therefore occur considerably faster in the transition zone than at depths of less than 410 kilometers. PMID:9888846

  9. Seismic evidence for olivine phase changes at the 410- and 660-kilometer discontinuities.

    PubMed

    Lebedev, Sergei; Chevrot, Sébastien; van der Hilst, Rob D

    2002-05-17

    The view that the seismic discontinuities bounding the mantle transition zone at 410- and 660-kilometer depths are caused by isochemical phase transformations of the olivine structure is debated. Combining converted-wave measurements in East Asia and Australia with seismic velocities from regional tomography studies, we observe a correlation of the thickness of, and wavespeed variations within, the transition zone that is consistent with olivine structural transformations. Moreover, the seismologically inferred Clapeyron slopes are in agreement with the mineralogical Clapeyron slopes of the (Mg,Fe)2SiO4 spinel and postspinel transformations. PMID:12016311

  10. 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

  11. Photographer : JPL Range : 6 million kilometers (3.7 million miles) Central Longitude 120 degrees

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Photographer : JPL Range : 6 million kilometers (3.7 million miles) Central Longitude 120 degrees west, North is up. and 3rd from the planet. Photo taken after midnight Ganymede is slightly larger than Mercury but much less dense (twice the density of water). Its surface brightness is 4 times of Earth's Moon. Mare regions (dark features) are like the Moon's but have twice the brightness, and believed to be unlikely of rock or lava as the Moon's are. It's north pole seems covered with brighter material and may be water frost. Scattered brighter spots may be related to impact craters or source of fresh ice.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. Jupiter's decameter and kilometer emissions: satellite effects and long term periodicities

    SciTech Connect

    St. Cyr, O.C.

    1985-01-01

    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. Concepts of electromagnetic induction in planet-sized bodies are reviewed and 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 emissions, the author addresses the problem of orbital resonance among the Galilean satellites. When IO's influence in the emissions is eliminated from more than two decades of ground-based observation, no significant enhancements or deficiencies in the detection probability were found for the phases of Europa, Ganymede, or Callisto. A secondary goal was to search for long term periodicities and other effects in the ground-based DAM data. As expected, a strong tendency toward an increase or decrease, respectively, in D/sub E/ was found.

  2. Kilometer-scale topographic roughness of Mercury: Correlation with geologic features and units

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    We present maps of the topographic roughness of the northern circumpolar area of 30 Mercury at kilometer scales. The maps are derived from range profiles obtained by the 31 Mercury Laser Altimeter (MLA) instrument onboard the MErcury Surface, Space 32 ENvironment, Geochemistry, and Ranging (MESSENGER) mission. As measures of 33 roughness, we used the interquartile range of profile curvature at three baselines: 0.7 km, 34 2.8 km, and 11 km. The maps provide a synoptic overview of variations of typical 35 topographic textures. They show a dichotomy between the smooth northern plains and 36 rougher, more heavily cratered terrains. Analysis of the scale dependence of roughness 37 indicates that the regolith on Mercury is thicker than on the Moon by approximately a 38 factor of three. Roughness contrasts within northern volcanic plains of Mercury indicate a 39 younger unit inside Goethe basin and inside another unnamed stealth basin. These new 40 data permit interplanetary comparisons of topographic roughness.

  3. Preliminary Design, Feasibility and Cost Evaluation of 1- to 15-Kilometer Height Steel Towers

    NASA Technical Reports Server (NTRS)

    Shanker, Ajay

    2003-01-01

    Design and construction of tall towers is an on-going research program of NASA. The agency has already done preliminary review in this area and has determined that multi-kilometer height towers are technically and economically feasible. The proposed towers will provide high altitude launch platforms reaching above eighty percent of Earth's atmosphere and provide tremendous gains in the potential energy as well as substantial reduction in aerodynamic drag. NASA has also determined that a 15-KM tower will have many useful applications in: (i)Meteorology,(ii)Oceanography, (iii)Astronomy, (iv)High Altitude Launch, (v)Physics Drop Tower, (vi) Biosphere Research, (vii) Nanotechnology, (viii) Energy/Power, (ix)Broadband Wireless Technology, (x)Space Transportation and (xi)Space Tourism.

  4. Swarm observations of kilometer-scale low-altitude cusp/cleft ion upflow and downflow

    NASA Astrophysics Data System (ADS)

    Burchill, J. K.; Knudsen, D. J.; Buchert, S. C.

    2015-12-01

    The European Space Agency's Swarm mission is used to study the physics of the F region cusp/cleft ion fountain. In brief, the cleft ion fountain is a region where large fluxes of terrestrial plasma, including relatively heavy ions such as oxygen, are observed to escape into space. Such atmospheric loss is driven by and can influence magnetospheric processes. The three Swarm satellites are well-suited for investigating the properties of the low-altitude ionospheric reservoir thought to be significant in supplying plasma for high-altitude outflows. Each satellite is instrumented to measure ion velocity, plasma density and temperature, and electric and magnetic fields at cadences of 2 samples/s and higher. We probe the structuring of ion upflow and downflow at kilometer scales by investigating the relationship between upflow and ion heating, electron heating, and field-aligned electric currents.

  5. A 920-kilometer optical fiber link for frequency metrology at the 19th decimal place.

    PubMed

    Predehl, K; Grosche, G; Raupach, S M F; Droste, S; Terra, O; Alnis, J; Legero, Th; Hänsch, T W; Udem, Th; Holzwarth, R; Schnatz, H

    2012-04-27

    Optical clocks show unprecedented accuracy, surpassing that of previously available clock systems by more than one order of magnitude. Precise intercomparisons will enable a variety of experiments, including tests of fundamental quantum physics and cosmology and applications in geodesy and navigation. Well-established, satellite-based techniques for microwave dissemination are not adequate to compare optical clocks. Here, we present phase-stabilized distribution of an optical frequency over 920 kilometers of telecommunication fiber. We used two antiparallel fiber links to determine their fractional frequency instability (modified Allan deviation) to 5 × 10(-15) in a 1-second integration time, reaching 10(-18) in less than 1000 seconds. For long integration times τ, the deviation from the expected frequency value has been constrained to within 4 × 10(-19). The link may serve as part of a Europe-wide optical frequency dissemination network.

  6. Intense sub-kilometer-scale boundary layer rolls observed in hurricane fran

    PubMed

    Wurman; Winslow

    1998-04-24

    High-resolution observations obtained with the Doppler On Wheels (DOW) mobile weather radar near the point of landfall of hurricane Fran (1996) revealed the existence of intense, sub-kilometer-scale, boundary layer rolls that strongly modulated the near-surface wind speed. It is proposed that these structures are one cause of geographically varying surface damage patterns that have been observed after some landfalling hurricanes and that they cause much of the observed gustiness, bringing high-velocity air from aloft to the lowest observable levels. High-resolution DOW radar observations are contrasted with lower-resolution observations obtained with an operational weather radar, which underestimated peak low-level wind speeds.

  7. Evaluating the effect of internal aperture variability on transport in kilometer scale discrete fracture networks

    NASA Astrophysics Data System (ADS)

    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 field-scale fracture networks has been under a matter of debate for a long time because 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]. A recently developed discrete fracture network (DFN) simulation capability, dfnWorks, is used to generate 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. It is observed that due to local flow channeling early particle travel times are more sensitive to in-fracture variability than the tails of travel time distributions, where no significant effect of the in-fracture transmissivity variations and spatial correlation length is observed.

  8. Evaluating the effect of internal aperture variability on transport in kilometer scale discrete fracture networks

    DOE PAGESBeta

    Makedonska, Nataliia; Hyman, Jeffrey D.; Karra, Satish; Painter, Scott L.; Gable, Carl W.; Viswanathan, Hari S.

    2016-06-17

    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 kilometer18 scale field–scale fracture networks has been under a matter of debate for a long time because 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 withinmore » large-scale fracture networks. We address this question by incorporating internal heterogeneity of individual fractures into 23 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]. A recently developed discrete fracture network (DFN) simulation capability, dfnWorks, is used to generate 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. It is observed that due to local flow channeling early particle travel times are more sensitive to in-fracture variability than the tails of travel time distributions, where no significant effect of the in-fracture transmissivity variations and spatial correlation length is observed.« less

  9. 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

    ... 20 CFR part 662. Consistent with those provisions: (1) Core services for adults and dislocated... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What is the role of the adult and dislocated... AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE...

  10. Structure of the Edgeworth-Kuiper Belt (EKB) Dust Disk and Implications for Extrasolar Planet(s) epsilon Eridani

    NASA Technical Reports Server (NTRS)

    Liou, J. -C.; Zook, H. A.; Greaves, J. S.; Holland, W. S.; Boehnhardt, H.; Hahn, J. M.

    2000-01-01

    Numerical simulations of the orbital evolution of dust particles from Edgeworth-Kuiper Belt (EKB) objects show that the three giant planets, Neptune, Jupiter, and Saturn impose distinct and dramatic signatures on the overall distribution of EKB dust particles. The features are very similar to those observed in the dust disk around the nearby star Eridani. Numerical simulations of dust particles in the epsilon Eridani system show that planetary perturbations may be responsible for the observed features

  11. RETENTION OF A PRIMORDIAL COLD CLASSICAL KUIPER BELT IN AN INSTABILITY-DRIVEN MODEL OF SOLAR SYSTEM FORMATION

    SciTech Connect

    Batygin, Konstantin; Brown, Michael E.; Fraser, Wesley C.

    2011-09-01

    The cold classical population of the Kuiper Belt exhibits a wide variety of unique physical characteristics, which collectively suggest that its dynamical coherence has been maintained throughout the solar system's lifetime. Simultaneously, the retention of the cold population's relatively unexcited orbital state has remained a mystery, especially in the context of a solar system formation model, that is driven by a transient period of instability, where Neptune is temporarily eccentric. Here, we show that the cold belt can survive the instability, and its dynamical structure can be reproduced. We develop a simple analytical model for secular excitation of cold Kuiper Belt objects and show that comparatively fast apsidal precession and nodal recession of Neptune, during the eccentric phase, are essential for preservation of an unexcited state in the cold classical region. Subsequently, we confirm our results with self-consistent N-body simulations. We further show that contamination of the hot classical and scattered populations by objects of similar nature to that of cold classicals has been instrumental in shaping the vast physical diversity inherent to the Kuiper Belt.

  12. A CHANGE IN THE LIGHT CURVE OF KUIPER BELT CONTACT BINARY (139775) 2001 QG{sub 298}

    SciTech Connect

    Lacerda, Pedro

    2011-09-15

    New observations show that the light curve of Kuiper Belt contact binary (139775) 2001 QG{sub 298} has changed substantially since the first observations in 2003. The 2010 light curve has a peak-to-peak photometric range of {Delta}m{sub 2010} = 0.7 {+-} 0.1 mag, significantly lower than in 2003, {Delta}m{sub 2003} = 1.14 {+-} 0.04 mag. This change is most simply interpreted if 2001 QG{sub 298} has an obliquity near 90{sup 0}. The observed decrease in {Delta}m is caused by a change in viewing geometry, from equator-on in 2003 to nearly 16{sup 0} (the orbital angular distance covered by the object between the observations) off the equator in 2010. The 2003 and 2010 light curves have the same rotation period and appear in phase when shifted by an integer number of full rotations, also consistent with high obliquity. Based on the new 2010 light curve data, we find that 2001 QG{sub 298} has an obliquity of {epsilon} = 90{sup 0} {+-} 30{sup 0}. Current estimates of the intrinsic fraction of contact binaries in the Kuiper Belt are debiased assuming that these objects have randomly oriented spins. If, as 2001 QG2{sub 98}, Kuiper Belt Object contact binaries tend to have large obliquities, a larger correction is required. As a result, the abundance of contact binaries may be larger than previously believed.

  13. Bioinspired design and macroscopic assembly of poly(vinyl alcohol)-coated graphene into kilometers-long fibers

    NASA Astrophysics Data System (ADS)

    Kou, Liang; Gao, Chao

    2013-05-01

    Nacre is characterized by its excellent mechanical performance due to the well-recognized ``brick and mortar'' structure. Many efforts have been applied to make nacre-mimicking materials, but it is still a big challenge to realize their continuous production. Here, we prepared sandwich-like building blocks of poly(vinyl alcohol) (PVA)-coated graphene, and achieved high-nanofiller-content kilometers-long fibers by continuous wet-spinning assembly technology. The fibers have a strict ``brick and mortar'' layered structure, with graphene sheet as rigid brick and PVA as soft mortar. The mortar thickness can be precisely tuned from 2.01 to 3.31 nm by the weight feed ratio of PVA to graphene, as demonstrated by both atomic force microscopy and X-ray diffraction measurements. The mechanical strength of the nacre-mimicking fibers increases with increasing the content of PVA, and it rises gradually from 81 MPa for the fiber with 53.1 wt% PVA to 161 MPa for the fiber with 65.8 wt% PVA. The mechanical performance of our fibers was independent of the molecular weight (MW) of PVA in the wide range of 2-100 kDa, indicating that low MW polymers can also be used to make strong nanocomposites. The tensile stress of fibers immersed in PVA 5 wt% solution reached ca. 200 MPa, surpassing the values of nacre and most of other nacre-mimicking materials. The nacre-mimicking fibers are highly electrically conductive (~350 S m-1) after immersing in hydroiodic acid, enabling them to connect a circuit to illuminate an LED lamp.Nacre is characterized by its excellent mechanical performance due to the well-recognized ``brick and mortar'' structure. Many efforts have been applied to make nacre-mimicking materials, but it is still a big challenge to realize their continuous production. Here, we prepared sandwich-like building blocks of poly(vinyl alcohol) (PVA)-coated graphene, and achieved high-nanofiller-content kilometers-long fibers by continuous wet-spinning assembly technology. The fibers

  14. THE CANADA-FRANCE ECLIPTIC PLANE SURVEY-L3 DATA RELEASE: THE ORBITAL STRUCTURE OF THE KUIPER BELT

    SciTech Connect

    Kavelaars, J. J.; Jones, R. L.; Murray, I.; Gladman, B. J.; Petit, J.-M.; Van Laerhoven, C.; Parker, Joel Wm.; Bieryla, A.; Nicholson, P.; Margot, J. L.; Rousselot, P.; Mousis, O.; Scholl, H.; Marsden, B.; Benavidez, P.; Campo Bagatin, A.; Doressoundiram, A.; Veillet, C.

    2009-06-15

    We report the orbital distribution of the trans-Neptunian comets discovered during the first discovery year of the Canada-France Ecliptic Plane Survey (CFEPS). CFEPS is a Kuiper Belt object survey based on observations acquired by the Very Wide component of the Canada-France-Hawaii Telescope Legacy Survey (LS-VW). The first year's detections consist of 73 Kuiper Belt objects, 55 of which have now been tracked for three years or more, providing precise orbits. Although this sample size is small compared to the world-wide inventory, because we have an absolutely calibrated and extremely well-characterized survey (with known pointing history) we are able to de-bias our observed population and make unbiased statements about the intrinsic orbital distribution of the Kuiper Belt. By applying the (publically available) CFEPS Survey Simulator to models of the true orbital distribution and comparing the resulting simulated detections to the actual detections made by the survey, we are able to rule out several hypothesized Kuiper Belt object orbit distributions. We find that the main classical belt's so-called 'cold' component is confined in semimajor axis (a) and eccentricity (e) compared to the more extended 'hot' component; the cold component is confined to lower e and does not stretch all the way out to the 2:1 resonance but rather depletes quickly beyond a = 45 AU. For the cold main classical belt population we find a robust population estimate of N(H{sub g} < 10) = 50 {+-} 5 x 10{sup 3} and find that the hot component of the main classical belt represents {approx}60% of the total population. The inner classical belt (sunward of the 3:2 mean-motion resonance) has a population of roughly 2000 trans-Neptunian objects with absolute magnitudes H{sub g} < 10, and may not share the inclination distribution of the main classical belt. We also find that the plutino population lacks a cold low-inclination component, and so, the population is somewhat larger than recent estimates

  15. A Chemical and Dynamical Link Between Red Centaur Objects and the Cold Classical Kuiper Belt

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    We present new B-V, V-R, and B-R colors for 32 Centaurs objects using the 4.3-meter Discovery Channel Telescope (DCT) near Happy Jack, AZ and the 1.8-meter Vatican Advanced Technology Telescope on Mt. Graham, AZ. Combining these new colors with our previously reported colors, we now have optical broad-band colors for 58 Centaur objects.Application of the non-parametric Dip Test to our previous sample of only 26 objects showed Centaurs split into gray and red groups at the 99.5% confidence level, and application of the Wilcoxon Rank Sum Test to the same sample showed that red Centaurs have a higher median albedo than gray Centaurs at the 99% confidence level (Tegler et al., 2008, Solar System Beyond Neptune, U Arizona Press, pp. 105-114).Here we report application of the Wilcoxon Rank Sum Test to our sample of 58 Centaurs. We confirm red Centaurs have a higher median albedo than gray Centaurs at the 99.7% level. In addition, we find that red Centaurs have a lower median inclination angle than gray Centaurs at the 99.5% confidence level. Because of their red colors and lower inclination angles, we suggest red Centaurs originate in the cold classical Kuiper belt. We thank the NASA Solar System Observations Program for its support.

  16. Kuiper Airborne Observatory's Telescope Stabilization System: Disturbance Sensitivity Reduction Via Velocity Loop Feedback

    NASA Technical Reports Server (NTRS)

    Lawrence, David P.; Tsui, K. C.; Tucker, John; Mancini, Ronald E. (Technical Monitor)

    1995-01-01

    In July of 1994 the Kuiper Airborne Observatory's (KAO) Telescope Stabilization System (TSS) was upgraded to meet performance goals necessary to view the Shoemaker-Levy 9 comet collision with Jupiter. The KAO is a modified C-141 Aircraft supporting a 36 inch Infrared telescope used to gather and analyze astronomical data. Before the upgrade, the TSS exhibited approximately a 10 arc-second resolution pointing accuracy. The majority of the inaccuracy was attributable to aircraft vibration and wind buffeting entering through the aircraft's telescope door opening; in other words, the TSS was overly sensitive to external disturbances. Because of power limitations and noise requirements, improving the pointing accuracy of the telescope required more sophistication than simply raising the bandwidth as some classical control strategies might suggest. Instead, relationships were developed between the disturbance sensitivity and closed loop transfer functions. These relationships suggested that employing velocity feedback along with an increase in current loop gain would dramatically improve the pointing resolution of the TSS by decreasing the control system's sensitivity to external disturbances. With the implementation of some classical control techniques and the above philosophy, the KAO's TSS's resolution was improved to approximately 2-3 arc-seconds.

  17. DYNAMICAL HEATING INDUCED BY DWARF PLANETS ON COLD KUIPER BELT–LIKE DEBRIS DISKS

    SciTech Connect

    Muñoz-Gutiérrez, M. A.; Pichardo, B.; Peimbert, A.; Reyes-Ruiz, M.

    2015-10-01

    With the use of long-term numerical simulations, we study the evolution and orbital behavior of cometary nuclei in cold Kuiper belt–like debris disks under the gravitational influence of dwarf planets (DPs); we carry out these simulations with and without the presence of a Neptune-like giant planet. This exploratory study shows that in the absence of a giant planet, 10 DPs are enough to induce strong radial and vertical heating on the orbits of belt particles. On the other hand, the presence of a giant planet close to the debris disk, acts as a stability agent reducing the radial and vertical heating. With enough DPs, even in the presence of a Neptune-like giant planet some radial heating remains; this heating grows steadily, re-filling resonances otherwise empty of cometary nuclei. Specifically for the solar system, this secular process seems to be able to provide material that, through resonant chaotic diffusion, increase the rate of new comets spiraling into the inner planetary system, but only if more than the ∼10 known DP sized objects exist in the trans-Neptunian region.

  18. A giant impact origin for Pluto's small moons and satellite multiplicity in the Kuiper belt.

    PubMed

    Stern, S A; Weaver, H A; Steffl, A J; Mutchler, M J; Merline, W J; Buie, M W; Young, E F; Young, L A; Spencer, J R

    2006-02-23

    The two newly discovered satellites of Pluto (P1 and P2) have masses that are small compared to both Pluto and Charon-that is, between 5 x 10(-4) and 1 x 10(-5) of Pluto's mass, and between 5 x 10(-3) and 1 x 10(-4) of Charon's mass. This discovery, combined with the constraints on the absence of more distant satellites of Pluto, reveal that Pluto and its moons comprise an unusual, highly compact, quadruple system. These facts naturally raise the question of how this puzzling satellite system came to be. Here we show that P1 and P2's proximity to Pluto and Charon, the fact that P1 and P2 are on near-circular orbits in the same plane as Pluto's large satellite Charon, along with their apparent locations in or near high-order mean-motion resonances, all probably result from their being constructed from collisional ejecta that originated from the Pluto-Charon formation event. We also argue that dust-ice rings of variable optical depths form sporadically in the Pluto system, and that rich satellite systems may be found--perhaps frequently--around other large Kuiper belt objects. PMID:16495992

  19. A giant impact origin for Pluto's small moons and satellite multiplicity in the Kuiper belt

    NASA Astrophysics Data System (ADS)

    Stern, S. A.; Weaver, H. A.; Steffl, A. J.; Mutchler, M. J.; Merline, W. J.; Buie, M. W.; Young, E. F.; Young, L. A.; Spencer, J. R.

    2006-02-01

    The two newly discovered satellites of Pluto (P1 and P2) have masses that are small compared to both Pluto and Charon-that is, between 5 × 10-4 and 1 × 10-5 of Pluto's mass, and between 5 × 10-3 and 1 × 10-4 of Charon's mass. This discovery, combined with the constraints on the absence of more distant satellites of Pluto, reveal that Pluto and its moons comprise an unusual, highly compact, quadruple system. These facts naturally raise the question of how this puzzling satellite system came to be. Here we show that P1 and P2's proximity to Pluto and Charon, the fact that P1 and P2 are on near-circular orbits in the same plane as Pluto's large satellite Charon, along with their apparent locations in or near high-order mean-motion resonances, all probably result from their being constructed from collisional ejecta that originated from the Pluto-Charon formation event. We also argue that dust-ice rings of variable optical depths form sporadically in the Pluto system, and that rich satellite systems may be found-perhaps frequently-around other large Kuiper belt objects.

  20. Migration of Matter from the Edgeworth-Kuiper and Main Asteroid Belts to the Earth

    NASA Technical Reports Server (NTRS)

    Ipatov. S. I.; Oegerle, William (Technical Monitor)

    2002-01-01

    The main asteroid belt (MAB), the Edgeworth-Kuiper belt (EKB), and comets belong to the main sources of dust in the Solar System. Most of Jupiter-family comets came from the EKB. Comets can be distracted due to close encounters with planets and the Sun, collisions with small bodies, a nd internal forces. We support the Eneev's idea that the largest objects in the ELB and MAB could be formed directly by the compression of rarefied dust condensations of the protoplanetary cloud but not by the accretion of small (for example, 1-km) planetesimals. The total mass of planetesimals that entered the EKB from the feeding zone of the giant planets during their accumulation could exceed tens of Earth's masses. These planetesimals increased eccentricities of 'local' trans-Neptunian objects (TNOs) and swept most of these TNOs. A small portion of such planetesimals could left beyond Neptune's orbit in highly eccentric orbits. The results of previous investigations of migration and collisional evolution of minor bodies were summarized. Mainly our recent results are presented.

  1. Prerequisites for explosive cryovolcanism on dwarf planet-class Kuiper belt objects

    NASA Astrophysics Data System (ADS)

    Neveu, M.; Desch, S. J.; Shock, E. L.; Glein, C. R.

    2015-01-01

    Explosive extrusion of cold material from the interior of icy bodies, or cryovolcanism, has been observed on Enceladus and, perhaps, Europa, Triton, and Ceres. It may explain the observed evidence for a young surface on Charon (Pluto's surface is masked by frosts). Here, we evaluate prerequisites for cryovolcanism on dwarf planet-class Kuiper belt objects (KBOs). We first review the likely spatial and temporal extent of subsurface liquid, proposed mechanisms to overcome the negative buoyancy of liquid water in ice, and the volatile inventory of KBOs. We then present a new geochemical equilibrium model for volatile exsolution and its ability to drive upward crack propagation. This novel approach bridges geophysics and geochemistry, and extends geochemical modeling to the seldom-explored realm of liquid water at subzero temperatures. We show that carbon monoxide (CO) is a key volatile for gas-driven fluid ascent; whereas CO2 and sulfur gases only play a minor role. N2, CH4, and H2 exsolution may also drive explosive cryovolcanism if hydrothermal activity produces these species in large amounts (a few percent with respect to water). Another important control on crack propagation is the internal structure: a hydrated core makes explosive cryovolcanism easier, but an undifferentiated crust does not. We briefly discuss other controls on ascent such as fluid freezing on crack walls, and outline theoretical advances necessary to better understand cryovolcanic processes. Finally, we make testable predictions for the 2015 New Horizons flyby of the Pluto-Charon system.

  2. Dispersal of Disks Around Young Stars: Constraints on Kuiper Belt Formation

    NASA Technical Reports Server (NTRS)

    Hollenbach, David; DeVincenzi, Donald (Technical Monitor)

    2002-01-01

    We review the evidence pertaining to the lifetimes of planet-forming disks and discuss possible disk dispersal mechanisms: 1) viscous accretion of material onto the central source; 2) close stellar encounters; 3) stellar winds; and 4) photoevaporation by ultraviolet radiation. We focus on 3) and 4) and describe the quasi-steady state appearance and the overall evolution of disks under the influence of winds and radiation from the central star and of radiation from external OB stars. Viscous accretion likely dominates disk dispersal in the inner disk (r approx. <= 10 AU), while photoevaporation is the principal process of disk dispersal outside of r approx. >= 10 AU for low mass stars. Disk dispersal timescales are compared and discussed in relation to theoretical estimates for planet formation timescales. Photoevaporation may explain the large differences in the hydrogen content of the giant planets in the solar system. The commonly held belief that our early sun's stellar wind dispersed the solar nebula is called into question. Finally, we study the constraints that the evaporation of the outer disk has on the formation of Kuiper belts in extrasolar planetary systems.

  3. Environmental Impact Specification for Direct Space Weathering of Kuiper Belt and Oort Cloud Objects

    NASA Technical Reports Server (NTRS)

    Cooper, John F.

    2010-01-01

    The Direct Space Weathering Project of NASA's Outer Planets Research Program addresses specification of the plasma and energetic particle environments for irradiation and surface chemical processing of icy bodies in the outer solar system and the local interstellar medium. Knowledge of the radiation environments is being expanded by ongoing penetration of the twin Voyager spacecraft into the heliosheath boundary region of the outer heliosphere and expected emergence within the next decade into the very local interstellar medium. The Voyager measurements are being supplemented by remote sensing from Earth orbit of energetic neutral atom emission from this boundary region by NASA's Interstellar Boundary Explorer (IBEX). Although the Voyagers long ago passed the region of the Classical Kuiper Belt, the New Horizons spacecraft will encounter Pluto in 2015 and thereafter explore one or more KBOs, meanwhile providing updated measurements of the heliospheric radiation environment in this region. Modeling of ion transport within the heliosphere allows specification of time-integrated irradiation effects while the combination of Voyager and IBEX data supports projection of the in-situ measurements into interstellar space beyond the heliosheath. Transformation of model ion flux distributions into surface sputtering and volume ionization profiles provides a multi-layer perspective for space weathering impact on the affected icy bodies and may account for some aspects of color and compositional diversity. Other important related factors may include surface erosion and gardening by meteoritic impacts and surface renewal by cryovolcanism. Chemical products of space weathering may contribute to energy resources for the latter.

  4. Fiber-coupled high resolution infrared array spectrometer for the Kuiper Airborne Observatory

    NASA Technical Reports Server (NTRS)

    Glenar, D. A.; Reuter, D.; Mumma, M. J.; Chin, G.; Wiedemann, G.; Jennings, D.

    1990-01-01

    A novel cryogenic grating spectrometer (FCAS) is being designed for observations of volatiles in cometary and planetary atmospheres, and in newly forming planetary systems. The instrument features two-dimensional detector arrays coupled to a high-dispersion echelle by infrared fibers, and will achieve a spectral resolving power of about 40,000. The primary observational platform for this instrument will be the Kuiper Airborne Observatory, but it will also be configured for use at ground-based observatories. Initially, the spectrometer will use a 58 x 62, 1- to 5-micron InSb array. Larger-format IR arrays and arrays of different composition, will later be incorporated as they become available. The instrument will be used in two modes. The first uses a large format IR array in the spectral image plane for the customary one-dimensional spectral-one-dimensional spatial coverage. In the second mode, a massive, coherent bundle of infrared transmitting ZrF4 fibers will be installed after the dispersive element, to reformat the two-dimensional array into an elongated one-dimensional array for wide spectral coverage, allowing multiple lines to be measured in a single integration with high sensitivity. The overall instrument design is discussed, and the system sensitivity is estimated.

  5. A giant impact origin for Pluto's small moons and satellite multiplicity in the Kuiper belt.

    PubMed

    Stern, S A; Weaver, H A; Steffl, A J; Mutchler, M J; Merline, W J; Buie, M W; Young, E F; Young, L A; Spencer, J R

    2006-02-23

    The two newly discovered satellites of Pluto (P1 and P2) have masses that are small compared to both Pluto and Charon-that is, between 5 x 10(-4) and 1 x 10(-5) of Pluto's mass, and between 5 x 10(-3) and 1 x 10(-4) of Charon's mass. This discovery, combined with the constraints on the absence of more distant satellites of Pluto, reveal that Pluto and its moons comprise an unusual, highly compact, quadruple system. These facts naturally raise the question of how this puzzling satellite system came to be. Here we show that P1 and P2's proximity to Pluto and Charon, the fact that P1 and P2 are on near-circular orbits in the same plane as Pluto's large satellite Charon, along with their apparent locations in or near high-order mean-motion resonances, all probably result from their being constructed from collisional ejecta that originated from the Pluto-Charon formation event. We also argue that dust-ice rings of variable optical depths form sporadically in the Pluto system, and that rich satellite systems may be found--perhaps frequently--around other large Kuiper belt objects.

  6. Orbital clustering of distant Kuiper belt objects by hypothetical Planet 9. Secular or resonant?

    NASA Astrophysics Data System (ADS)

    Beust, H.

    2016-05-01

    Context. Statistical analysis of the orbits of distant Kuiper belt objects (KBOs) has led to the suggestion that an additional planet should reside in the solar system. According to recent models, the secular action of this body should cause orbital alignment of the KBOs. Aims: It was recently claimed that the KBOs affected by these dynamics are presumably trapped in mean-motion resonances with the suspected planet. I reinvestigate here the secular model underlying this idea. Methods: The original analysis was carried out by expanding and truncating the secular Hamiltonian. I show that this is inappropriate, as the series expansion is not convergent. I present a study based on numerical computation of the Hamiltonian with no expansion. Results: I show in phase-space diagrams the existence of apsidally anti-aligned, high eccentricity libration islands that were not present in the original modelling, but match numerical simulations. These island were claimed to correspond to bodies trapped in mean-motion resonances with the hypothetical planet and match the characteristics of the distant KBOs observed. Conclusions: My main result is that regular secular dynamics can account for the anti-aligned particles itself as well as mean-motion resonances. I also perform a semi-analytical study of resonant motion and show that some resonance are actually capable of producing the same libration islands. I then discuss the relative importance of both mechanisms.

  7. ON A POSSIBLE SIZE/COLOR RELATIONSHIP IN THE KUIPER BELT

    SciTech Connect

    Pike, R. E.; Kavelaars, J. J.

    2013-10-01

    Color measurements and albedo distributions introduce non-intuitive observational biases in size-color relationships among Kuiper Belt Objects (KBOs) that cannot be disentangled without a well characterized sample population with systematic photometry. Peixinho et al. report that the form of the KBO color distribution varies with absolute magnitude, H. However, Tegler et al. find that KBO color distributions are a property of object classification. We construct synthetic models of observed KBO colors based on two B-R color distribution scenarios: color distribution dependent on H magnitude (H-Model) and color distribution based on object classification (Class-Model). These synthetic B-R color distributions were modified to account for observational flux biases. We compare our synthetic B-R distributions to the observed ''Hot'' and ''Cold'' detected objects from the Canada-France Ecliptic Plane Survey and the Meudon Multicolor Survey. For both surveys, the Hot population color distribution rejects the H-Model, but is well described by the Class-Model. The Cold objects reject the H-Model, but the Class-Model (while not statistically rejected) also does not provide a compelling match for data. Although we formally reject models where the structure of the color distribution is a strong function of H magnitude, we also do not find that a simple dependence of color distribution on orbit classification is sufficient to describe the color distribution of classical KBOs.

  8. A hardware/software simulation for the video tracking system of the Kuiper Airborne Observatory telescope

    NASA Technical Reports Server (NTRS)

    Boozer, G. A.; Mckibbin, D. D.; Haas, M. R.; Erickson, E. F.

    1984-01-01

    This simulator was created so that C-141 Kuiper Airborne Observatory investigators could test their Airborne Data Acquisition and Management System software on a system which is generally more accessible than the ADAMS on the plane. An investigator can currently test most of his data acquisition program using the data computer simulator in the Cave. (The Cave refers to the ground-based computer facilities for the KAO and the associated support personnel.) The main Cave computer is interfaced to the data computer simulator in order to simulate the data-Exec computer communications. However until now, there has been no way to test the data computer interface to the tracker. The simulator described here simulates both the KAO Exec and tracker computers with software which runs on the same Hewlett-Packard (HP) computer as the investigator's data acquisition program. A simulator control box is hardwired to the computer to provide monitoring of tracker functions, to provide an operator panel similar to the real tracker, and to simulate the 180 deg phase shifting of the chopper squre-wave reference with beam switching. If run in the Cave, one can use their Exec simulator and this tracker simulator.

  9. 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...

  10. The nature of the 660-kilometer discontinuity in Earth's mantle from global seismic observations of PP precursors.

    PubMed

    Deuss, Arwen; Redfern, Simon A T; Chambers, Kit; Woodhouse, John H

    2006-01-13

    The 660-kilometer discontinuity, which separates Earth's upper and lower mantle, has been detected routinely on a global scale in underside reflections of precursors to SS shear waves. Here, we report observations of this discontinuity in many different regions, using precursors to compressional PP waves. The apparent absence of such precursors in previous studies had posed major problems for models of mantle composition. We find a complicated structure, showing single and double reflections ranging in depth from 640 to 720 kilometers, that requires the existence of multiple phase transitions at the base of the transition zone. The results are consistent with a pyrolite mantle composition.

  11. CPR evolution of kilometer-scale craters on the lunar mare

    NASA Astrophysics Data System (ADS)

    King, Isabel; Fassett, Caleb; Thomson, Bradley J.; Minton, David A.; Watters, Wesley A.

    2016-10-01

    This study analyzes the 12.6-cm radar signature of kilometer-scale craters using data from the Mini-RF instrument on the Lunar Reconnaissance Orbiter. We examine the circular polarization ratio (CPR), which is sensitive to rockiness and surface roughness at the decimeter scale, to determine if there is a relationship between CPR signature and age for craters on the lunar mare. The craters come from an existing dataset of >13,000 craters ranging 800 m to 5 km in diameter that have previously determined degradation states based on their topography. The locations of craters in the original data set were manually co-registered to Mini-RF level 2 observations from the PDS, and for each crater, radial CPR profiles were extracted. In total, there were 5,142 unique craters with Mini-RF observations; 914 craters had repeat measurements that were used to assess uncertainties in CPR profiles. To characterize the time evolution of CPR, the craters were analyzed by finding the median profiles for groups of craters sorted by age and diameter. The highest CPR values are found in the interiors of the craters, and for craters ≤2 km, the freshest craters have the highest CPR values. In the ejecta, fresh craters exhibit the highest CPR, and this decreases with time until an equilibrium is reached. As expected from theory, larger craters' profiles evolve less quickly, with only minor changes in CPR inside their rim and a slower decrease of CPR in their ejecta. In conjunction with other datasets like topography, optical maturity, and rockiness, these data are important for constraining models of regolith evolution and crater degradation on the Moon.

  12. Radiation Products in Processed Ices Relevant to Edgeworth-Kuiper-Belt Objects

    NASA Astrophysics Data System (ADS)

    Moore, M. H.; Hudson, R. L.; Ferrante, R. F.

    2003-06-01

    Near the inner edge of the Edgeworth-Kuiper Belt (EKB) are Pluto and Charon, which are known to have N2- and H2O-dominated surface ices, respectively. Such non-polar and polar ices, and perhaps mixtures of them, also may be present on other trans-Neptunian objects. Pluto, Charon, and all EKB objects reside in a weak, but constant UV-photon and energetic ion radiation environment that drives chemical reactions in their surface ices. Effects of photon and ion processing include changes in ice composition, volatility, spectra, and albedo, and these have been studied in a number of laboratories. This paper focuses on ice processing by ion irradiation and is aimed at understanding the volatiles, ions, and residues that may exist on outer solar system objects. We summarize radiation chemical products of N2-rich and H2O-rich ices containing CO or CH4, including possible volatiles such as alcohols, acids, and bases. Less-volatile products that could accumulate on EKB objects are observed to form in the laboratory from acid-base reactions, reactions promoted by warming, or reactions due to radiation processing of a relatively pure ice (e.g., CO --> C3O2). New IR spectra are reported for the 1-5 mu;m region, along with band strengths for the stronger features of carbon suboxide, carbonic acid, the ammonium and cyanate ions, polyoxymethylene, and ethylene glycol. These six materials are possible contributors to EKB surfaces, and will be of interest to observers and future missions.

  13. Comet-like mineralogy of olivine crystals in an extrasolar proto-Kuiper belt.

    PubMed

    de Vries, B L; Acke, B; Blommaert, J A D L; Waelkens, C; Waters, L B F M; Vandenbussche, B; Min, M; Olofsson, G; Dominik, C; Decin, L; Barlow, M J; Brandeker, A; Di Francesco, J; Glauser, A M; Greaves, J; Harvey, P M; Holland, W S; Ivison, R J; Liseau, R; Pantin, E E; Pilbratt, G L; Royer, P; Sibthorpe, B

    2012-10-01

    Some planetary systems harbour debris disks containing planetesimals such as asteroids and comets. Collisions between such bodies produce small dust particles, the spectral features of which reveal their composition and, hence, that of their parent bodies. A measurement of the composition of olivine crystals (Mg(2-2x)Fe(2x)SiO(4)) has been done for the protoplanetary disk HD 100546 (refs 3, 4) and for olivine crystals in the warm inner parts of planetary systems. The latter compares well with the iron-rich olivine in asteroids (x ≈ 0.29). In the cold outskirts of the β Pictoris system, an analogue to the young Solar System, olivine crystals were detected but their composition remained undetermined, leaving unknown how the composition of the bulk of Solar System cometary olivine grains compares with that of extrasolar comets. Here we report the detection of the 69-micrometre-wavelength band of olivine crystals in the spectrum of β Pictoris. Because the disk is optically thin, we can associate the crystals with an extrasolar proto-Kuiper belt a distance of 15-45 astronomical units from the star (one astronomical unit is the Sun-Earth distance), determine their magnesium-rich composition (x = 0.01 ± 0.001) and show that they make up 3.6 ± 1.0 per cent of the total dust mass. These values are strikingly similar to those for the dust emitted by the most primitive comets in the Solar System, even though β Pictoris is more massive and more luminous and has a different planetary system architecture. PMID:23038467

  14. Resonant Dynamics of Kuiper Belt Objects and Induced Biases in Surveys

    NASA Astrophysics Data System (ADS)

    Gladman, Brett

    2008-05-01

    A significant fraction of known trans-neptunian objects (TNOs) are known to inhabit mean-motion resonances with Neptune. (Pluto, in the 3:2 resonance, is the best known example). Recent work has shown that many other resonances are also populated (most especially the 6:5, 4:3, 7:4, 2:1, and 5:2). The resonance dynamics cause TNOs librating in the resonance to be distributed non-uniformly on the sky in the sense that the heliocentric distance becomes strongly correlated with the separation in longitude relative to Neptune. This has a strong dependence on the detectibility of resonant TNOs in observational surveys. An important piece of the dynamics is the study of how the libration amplitude of the resonant argument enters into the observability question, since the distribution of these resonant amplitudes can be a diagnostic of how the resonance may have been populated due to planetary migration allowing the capture of non-resonant objects into the resonances early in Solar System history. The libration amplitude distribution couples with the size and eccentricity distributions to determine the sensitivity of detection when a TNO search is conducted in a certain sky direction. I will show how these considerations can be used with calibrated TNO surveys to constrain the orbital element and size distributions of resonant objects in the Kuiper Belt. This goal is considerably complicated by the fact that many high-inclination resonant TNOs also co-inhabit the Kozai resonance. Such objects have a further strong effect introduced into their detectibility. This work is supported by NSERC, CFI, NASA-Planetary Astronomy, and the Canada Research Chairs program.

  15. OBSERVED BINARY FRACTION SETS LIMITS ON THE EXTENT OF COLLISIONAL GRINDING IN THE KUIPER BELT

    SciTech Connect

    Nesvorny, David; Vokrouhlicky, David; Bottke, William F.; Levison, Harold F.; Noll, Keith

    2011-05-15

    The size distribution in the cold classical Kuiper Belt (KB) can be approximated by two idealized power laws: one with steep slope for radii R > R* and one with shallow slope for R < R*, where R* {approx} 25-50 km. Previous works suggested that the size frequency distribution (SFD) rollover at R* can be the result of extensive collisional grinding in the KB that led to the catastrophic disruption of most bodies with R < R*. Here, we use a new code to test the effect of collisions in the KB. We find that the observed rollover could indeed be explained by collisional grinding provided that the initial mass in large bodies was much larger than the one in the present KB and was dynamically depleted. In addition to the size distribution changes, our code also tracks the effects of collisions on binary systems. We find that it is generally easier to dissolve wide binary systems, such as the ones existing in the cold KB today, than to catastrophically disrupt objects with R {approx} R*. Thus, the binary survival sets important limits on the extent of collisional grinding in the KB. We find that the extensive collisional grinding required to produce the SFD rollover at R* would imply a strong gradient of the binary fraction with R and separation, because it is generally easier to dissolve binaries with small components and/or those with wide orbits. The expected binary fraction for R {approx}< R* is {approx}<0.1. The present observational data do not show such a gradient. Instead, they suggest a large binary fraction of {approx}0.4 for R = 30-40 km. This may indicate that the rollover was not produced by disruptive collisions, but is instead a fossil remnant of the KB object formation process.

  16. Optical Spectra of the Large Kuiper Belt Objects 2003 EL61 and 2005 FY9

    NASA Astrophysics Data System (ADS)

    Tegler, Stephen C.; Grundy, W.; Consolmagno, G.; Romanishin, W.; Mogren, K.

    2006-09-01

    We present optical spectra (0.40 - 0.95 micron; fwhm 0.0020 micron) of the large Kuiper belt objects 2003 EL61 and 2005 FY9. The spectra were obtained with the Red Channel Spectrograph and the 6.5 meter MMT telescope on Mt Hopkins, AZ. Five 600-sec spectra of 2003 EL61 span 40 % of its rotational period. We find no evidence of ice absorption bands in any of the spectra nor any evidence of differences between the spectra. By combining the five spectra, we achieve a continuum signal to noise ratio of 200 near 0.577 and 0.627 micron. Such a signal to noise ratio enables us to rule out the presence of O2-ice on 2003 EL61 at an abundance seen on the surface of Ganymede (Spencer et al. 1995). In addition, the lack of the 0.890 micron CH4-ice band in our spectrum allows us to set an upper limit on the thickness of a global glaze of CH 4-ice at 0.3 mm. Our spectrum of 2005 FY9 exhibits deep CH 4-ice absorption at 0.620, 0.730, 0.786, 0.799, 0.844, 0.869, 0.890, and 0.902 micron in agreement with spectra of Licandro et al. 2006. The wavelengths of these absorption bands are consistent with pure CH4-ice. In addition, our spectrum exhibits weak CH 4-ice bands at 0.54, 0.58, and 0.60 micron. This is the first detection of these weak ice bands in laboratory or astrophysical spectra. We thank the NASA Planetary Astronomy Program for financial support of this research and the Steward Telescope Allocation Committee for allocation of telescope time.

  17. Evidence for Recent Resurfacing of the Binary Kuiper Belt Object 1997 CS29

    NASA Astrophysics Data System (ADS)

    Rabinowitz, David L.; Schaefer, B.; Schaefer, M.; Tourtellotte, S.

    2009-09-01

    At solar phase angles less than 0.1 deg, some icy bodies exhibit an extraordinary opposition surge, suddenly brightening by 50% at near zero phase. Verbiscer et al [1] observed this phenomena for the icy Galilean satellites Mimas, Enceladus, Tethys, Dione, and Rhea and suggest the surge results from the light-scattering properties of freshly resurfaced icy regoliths. Buratti et al [2] and Earle et al [3] observed a similarly sharp opposition surge on Neptune's icy satellite Triton, which is known to have active cryovolcanoes. Here we examine the solar phase curves of 9 Trans-Neptunian Objects that we have measured at phase angles smaller than 0.1 deg (Rabinowitz et al [4], Schaefer et al [5]), including previously unpublished observations 1997 CS29 and 2005 UJ438. This sample includes hot and cold classical Kuiper-Belt objects, Plutinos, Centaurs, and three binary TNOs. Of all these targets, only 1997 CS29 has a sharp surge at near zero phase, and a nearly flat phase curve at large angles. Since this target is also a binary with an unusually large and close companion [6], we suggest that both 1997 CS29 and its companion have been resurfaced by each other's impact ejecta via the mechanism proposed by Stern [7], with fresh surface material producing the opposition spike. [1] Verbiscer, A., et al. 2007, Science, 315, 815; [2] Buratti, B. et al. 2007, Workshop on Ices, Oceans, and Fire: Satellites of the Outer Solar System, Boulder Colorado; [3] Earle, D., et al. 2008, BAAS, 40, 480; [4] Rabinowitz, D. et al. 2007, AJ, 133, 26; [5] Schaefer, B., et al. 2009, AJ, 137, 129; [6] Stephens, D. & Knoll, K. 2006, AJ, 131,1142;[7] Stern, S. A. 2009, Icarus, 199, 571.

  18. THE ROTATION PERIOD AND LIGHT-CURVE AMPLITUDE OF KUIPER BELT DWARF PLANET 136472 MAKEMAKE (2005 FY9)

    SciTech Connect

    Heinze, A. N.; DeLahunta, Daniel E-mail: ddelahun@mail.rochester.edu

    2009-08-15

    Kuiper Belt dwarf planet 136472 Makemake, formerly known as 2005 FY9, is currently the third-largest known object in the Kuiper Belt, after the dwarf planets Pluto and Eris. It is currently second only to Pluto in apparent brightness, due to Eris' much larger heliocentric distance. Makemake shows very little photometric variability, which has prevented confident determination of its rotation period until now. Using extremely precise time-series photometry, we find that the rotation period of Makemake is 7.7710 {+-} 0.0030 hr, where the uncertainty is a 90% confidence interval. An alias period is detected at 11.41 hr, but is determined with approximately 95% confidence not to be the true period. Makemake's 7.77 hr rotation period is in the typical range for Kuiper Belt objects, consistent with Makemake's apparent lack of a substantial satellite to alter its rotation through tides. The amplitude of Makemake's photometric light curve is 0.0286 {+-} 0.0016 mag in V. This amplitude is about 10 times less than Pluto's, which is surprising given the two objects' similar sizes and spectral characteristics. Makemake's photometric variability is instead similar to that of Eris, which is so small that no confident rotation period has yet been determined. It has been suggested that dwarf planets such as Makemake and Eris, both farther from the Sun and colder than Pluto, exhibit lower photometric variability because they are covered with a uniform layer of frost. Such a frost is probably the correct explanation for Eris. However, it may be inconsistent with the spectrum of Makemake, which resembles reddish Pluto more than neutrally colored Eris. Makemake may instead be a more Pluto-like object that we observe at present with a nearly pole-on viewing geometry-a possibility that can be tested with continuing observations over the coming decades.

  19. Snow depth estimation, structure, prediction, and hydrologic modeling at the kilometer scale in the Colorado Rocky Mountains

    NASA Astrophysics Data System (ADS)

    McCreight, James L.

    Research focuses on observing and predicting spatial distribution of snow depth at the kilometer scale. Observation of spatial snow depth distribution is considered by its estimation from random, sparse observations and important factors affecting this estimation. Predicting spatial distribution of both snow depth and melt rates begins from simple hypothesis wherein the spatial distribution of snow depth is structured by the spatial distribution of controlling variables. Predictions made by this structured view are evaluated in spatial modeling of peak-accumulation snow depth and applied to spatial distribution of a point-scale, temperature-index model of snowmelt runoff using minimal parameter complexity. High-resolution light detection and ranging (LiDAR) measurements provide a rich backdrop for understanding estimation from sparse observations and developing our structured view of snow distribution. The data are used to illuminate the effects of sample size on estimation skill, the uncertainty in estimation due to random sampling, the effect of model resolution on estimation skill, and the difference between cross-validated skill and skill based on the entire distribution. None of these topics have previously been explored in the literature. The effect of predictor quality is also investigated. LiDAR derived predictors are compared to readily available predictors downloaded from the internet. Hierarchical cluster analysis is used to decompose spatial non-stationarity of snow depth and results match qualitative understanding of the spatial distribution of physical controls. The same methodology is then used to decompose spatial non-stationarity of physical controls and infer patterns of snow depth distribution independent of observations. Even when using readily-available predictors, predicted patterns require at least 100--200 observations to be matched by standard estimation methods. Predicted patterns are then applied to formulate a parameterized spatial

  20. Measuring 20-100 T B-fields using Zeeman splitting of sodium emission lines on a 500 kA pulsed power machine

    NASA Astrophysics Data System (ADS)

    Banasek, J. T.; Engelbrecht, J. T.; Pikuz, S. A.; Shelkovenko, T. A.; Hammer, D. A.

    2016-11-01

    We have shown that Zeeman splitting of the sodium (Na) D-lines at 5890 and 5896 Å can be used to measure the magnetic field (B-field) produced in high current pulsed power experiments. We have measured the B-field next to a return current conductor in a hybrid X-pinch experiment near a peak current of about 500 kA. Na is deposited on the conductor and then is desorbed and excited by radiation from the hybrid X-pinch. The D-line emission spectrum implies B-fields of about 20 T with a return current post of 4 mm diameter or up to 120 T with a return current wire of 0.455 mm diameter. These measurements were consistent or lower than the expected B-field, thereby showing that basic Zeeman splitting can be used to measure the B-field in a pulsed-power-driven high-energy-density (HED) plasma experiment. We hope to extend these measurement techniques using suitable ionized species to measurements within HED plasmas.

  1. An Icy Kuiper Belt Around the Young Solar-type Star HD 181327

    NASA Technical Reports Server (NTRS)

    Lebreton, J.; Augereau, J.-C.; Thi, W.-F.; Roberge, A.; Donaldson, J; Schneider, G.; Maddison, S. T.; Menard, F.; Riviere-Marichalar, P.; Matthews, G. S.; Kamp, I.; Pinte, C.; Dent, W. R. F.; Barrado, D.; Duchene, G.; Gonzalez, J.-F.; Grady C. A.; Meeus,G.; Pantin, E.; Williams, J. P.; Woitke, P.

    2012-01-01

    constraints on the gas disk, the age of HD 181327 and the properties of the dust disk suggest that it has passed the stage of gaseous planets formation. The dust reveals a population of icy planetesimals, similar to the primitive Edgeworth-Kuiper belt, that may be a source for the future delivery of water and volatiles onto forming terrestrial planets.

  2. An Icy Kuiper-Belt Around the Young Solar-Type Star HD 181327

    NASA Technical Reports Server (NTRS)

    Lebreton, J.; Augereau, J.-C.; Thi, W.-F.; Roberge, A.; Donaldson, J.; Schneider, G.; Maddison, S. T.; Menard, F.; Riviere-Marichalar, P.; Mathews, G. S.; Kamp, I.; Pinte, C.; Dent, W. R. F.; Barrado, D.; Duchene, G.; Gonzalez, J.-F.; Grady, C. A.; Meeus, G.; Pantin, E.; Williams, J. P.; Woitke, P.

    2011-01-01

    dust disk suggest that it has passed the stage of gaseous planets formation. The dust reveals a population of icy planetesimals, similar to the primitive Edgeworth-Kuiper Belt, that may be a source for the future delivery of water and volatiles onto forming terrestrial planets.

  3. A Low Density for Binary Kuiper Belt Object (26308) 1998 SM165

    NASA Astrophysics Data System (ADS)

    Spencer, John R.; Stansberry, J. A.; Grundy, W. M.; Noll, K. S.

    2006-09-01

    The densities of Kuiper Belt objects provide valuable clues to their composition, internal structure, and origin. To extend our limited knowledge of KBO densities, we have been attempting to obtain radiometric diameters for binary KBOs, which have masses determined from the satellite orbits, using the MIPS mid-IR imager on the Spitzer Space Telescope. Due to higher than expected KBO albedos, and MIPS's lower than expected 70 µm sensitivity, our 2006 campaign concentrated on long exposures on a single target, (26308) 1998 SM165, one of the brightest and warmest known KBO binaries. 7.5 hour integration times at both 24 and 70 µm yielded monochromatic fluxes of 0.11 ± 0.01 mJy at 23.7 microns and 6.1 ± 1.1 mJy at 71.4 microns. From these we derive a relatively model-independent diameter of 287 ± 36 km for the primary and 96 ± 12 km for the satellite, assuming similar albedos. The derived V geometric albedo (using HV = 6.13, Romanishin and Tegler 2006 Icarus 179 523) is 0.07 ± 0.02. The system mass from HST (Margot et al. 2004, DPS 36, 08.03) then yields a system density of 0.51 +0.29 -0.14 g cm-3, comparable to that for KBO (47171) 1999 TC36 (Stansberry et al. 2006, Ap. J. 643, 556). This density is also comparable to that of the similarly-sized planetary satellites Amalthea (D=200 km, ρ=0.86) and Hyperion (D=250 km, ρ=0.6), but much lower than the density of Phoebe (D=200 km, ρ=1.63), and suggests both high porosity and a dominantly water ice composition for this KBO, despite its low albedo and red color. Supporting visible-wavelength lightcurve observations obtained at Lowell Observatory also yielded a revised rotation rate of 8.40 ± 0.05 hours for 1998 SM165.

  4. Corralling a distant unseen planet with extreme resonant Kuiper belt objects

    NASA Astrophysics Data System (ADS)

    Malhotra, Renu; Volk, Kathryn; Wang, Xianyu

    2016-10-01

    Several recent studies have appealed to the clustering of the angular orbital elements of very distant, extreme Kuiper belt objects (eKBOs) to argue for the existence of a large planet in the distant solar system. We identify other properties of eKBOs that may support the existence of such an unseen planet. We observe that several eKBOs have orbital periods close to integer ratios with each other. These would be dynamically significant only if the eKBOs are in mean motion resonances (MMRs) with an unseen massive planet. If such MMRs are true, then their resonant dynamics can provide constraints on the planet's parameters and its current location in its orbital path. We calculate that a hypothetical planet with orbital period ~17,117 years (semimajor axis ~665 AU), could have small integer period ratios (of the form N/1 or N/2) with the four longest period eKBOs. Our calculations suggest two possibilities for the planet's orbit plane: a plane moderately close to the ecliptic (i~18°) or an inclined plane (i~48°). The former offers dynamical stability of the high-eccentricity eKBOs by means of libration of the relative longitudes, and the latter offers enhanced dynamical stability by means of additional libration of the argument of perihelion, ω. Standard theory of MMRs breaks down for the extremely high orbital eccentricities (~0.7–0.9) of the eKBOs. We developed asymptotic analytical approximations, supported by numerical analysis of the circular restricted three body problem, to estimate that a planet of mass >~10 M♀ has MMR widths large enough that the current orbital uncertainties of the eKBOs allow libration in the hypothesized MMRs, as well as libration of ω in the inclined planet case. Our calculations indicate that the planet's orbital eccentricity is unlikely to exceed ~0.3 for stable resonant librations of the eKBOs. Libration of critical resonant angles of the hypothesized MMRs of the eKBOs define exclusion zones of the current location of the

  5. Simulated MERTIS observation of the Rudaki-Kuiper craters area on Mercury

    NASA Astrophysics Data System (ADS)

    D'Amore, M.; Helbert, J.; Maturilli, A.; Ferrari, S.; Bauch, K.; D'Incecco, P.; Hiesinger, H.; Head, J. W.; Holsclaw, G. M.; Lorin, D. D.; Denevi, B. W.; Stockstill-Cahill, K. R.

    2013-12-01

    The MErcury Radiometer and Thermal infrared Imaging Spectrometer (MERTIS) is part of the payload of the BepiColombo mission. The mission is scheduled for launch in 2015 with arrival at Mercury in 2021. To achieve MERTIS's scientific goals the instrument maps the surface of Mercury with a spatial resolution of 500m for the spectrometer channel and 2km for the radiometer channel. MERTIS spans wavelength ranges of 7-14 and 7-40 μm with its two channels. Among it scientific goals, MERTIS will infer rock-forming minerals, map surface composition, and study surface temperature variations on Mercury with an uncooled microbolometer detector. To exploit the full potential of the unique MERTIS dataset, an extensive calibration campaign has been performed. This includes radiometric, spectral, and geometric calibration. In addition we have performed measurement of analog materials at temperatures of up to 500°C - similar to the peak temperatures expected at Mercury - with the MERTIS qualification model in the Planetary Emissivity Laboratory. These measurements allow for the evaluation of the MERTIS performance in direct comparison with the laboratory spectrometer. They also enable the creation of synthetic MERTIS datasets. For this purpose we use data from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft as baseline. MESSENGER can provide geological information as well as spectral information in the UV, visible and near-infrared wavelengths range. For a first test we have selected the Kuiper-Rudaki region. The region has been extensively covered by measurements from the MESSENGER spacecraft. Recent analysis of observations by the Mercury Atmospheric and Surface Composition Spectrometer (MASCS) instrument on the MESSENGER spacecraft with an unsupervised hierarchical clustering method shows at global scales two major units: a Polar region (PR) spectrally flat and redder than the equatorial region (ER). The study area is primarily

  6. Let's Dense - Modifying densities and compositions through collisions of Kuiper belt objects

    NASA Astrophysics Data System (ADS)

    Sarid, Gal; Stewart, Sarah T.; Grundy, Will

    2016-10-01

    Ice-rock bodies in the outer solar system preserve crucial information on past dynamical and physical conditions, through compositions and structure. Known dwarf planets have a large range of ice/rock ratios and maintain diverse satellite counterparts. Specific modification processes have not yet been demonstrated numerically and identification of intermediate evolution stages is lacking in simulations and observations.Barr & Schwamb (2016) hypothesized on how to interpret densities in the Kuiper belt according to different collision conditions, pointing to a two-mode process. We show how to reconstruct their distribution of primary density and satellite-to-total mass ratio, as a function of varying collision regimes, in similar and marginally-similar-sized collisions (dependent on target/impactor mass ratio). We varied the initial mass ratios, impact velocities and angles and differentiation state of large and mid-sized (300-1200 km in radius) colliding objects, in SPH-based shock physics simulations (using GADGET2 with EOS implementation). Fully, partial and non-differentiated initial configurations of each object are derived from a consistent calculation of thermal evolution histories and a pre-selected range in initial compositions and material properties.We will discuss the scaling of these simulations, as it informs our predictions for the survival and current presence of water and other volatile ice species. Intermediate-size KBOs (radii ~300-500 km) should be most amenable for buried ices to be resurfaced by impacts. A preliminary scaling relation between collision conditions and global shock processed state of the ice (H2O) and rock (silicate, serpentine) components will be discussed as well. We also predict the satellite-to-total mass ratio and primary density of objects that have not yet been observed to maintain a stable satellite system. These would be observations of massive satellites around ice-rich bodies. The predicted collision regime, between

  7. MICROWAVE EMISSION FROM THE EDGEWORTH-KUIPER BELT AND THE ASTEROID BELT CONSTRAINED FROM THE WILKINSON MICROWAVE ANISOTROPY PROBE

    SciTech Connect

    Ichikawa, Kazuhide; Fukugita, Masataka

    2011-08-01

    Objects in the Edgeworth-Kuiper Belt and the main asteroid belt should emit microwaves that may give rise to extra anisotropy signals in the multipole of the cosmic microwave background (CMB) experiment. Constraints are derived from the absence of positive detection of such anisotropies for l {approx}< 50, meaning the total mass of Edgeworth-Kuiper Belt objects is smaller than 0.2 M{sub +}. This limit is consistent with the mass extrapolated from the observable population with the size of a {approx}> 15 km, assuming that the small-object population follows the power law in size dN/da {approx} a{sup -q} with the canonical index expected for collisional equilibrium, q {approx_equal} 3.5, with which 23% of the mass is ascribed to objects smaller than are observationally accessible down to grains. A similar argument applied to the main asteroid belt indicates that the grain population should not increase more quickly than q {approx_equal} 3.6 toward smaller radii, if the grain population follows the power law that continues to observed asteroids with larger radii. Both cases are at or only slightly above the limit that can be physically significant, implying the importance of further tightening the CMB anisotropy limit, which may be attained with observation at higher radio frequencies.

  8. The Evolution of Saturn's Rings Under the Influence of the Edgeworth-Kuiper Belt Micrometeoroid Flux: Tightening the Constraints on Ring Age

    NASA Astrophysics Data System (ADS)

    Estrada, Paul R.; Durisen, Richard H.; Cuzzi, Jeffrey N.

    2016-10-01

    Results of the Cassini Dust Analyzer (CDA) experiment indicate that the determined range of the micrometeoroid flux at infinity for Saturn (Altobelli et al., 2015) may be comparable to the nominal value of the incident, flat-plate and one-sided meteoroid flux value currently adopted for use in ballistic transport applications and models (e.g., Estrada et al., 2015). Moreover, the source of the micrometeoroid flux has been localized to the Edgeworth-Kuiper Belt (EKB) and is not cometary in origin as previously assumed. Apart from suggesting an altogether different composition for the ring pollutant, a major consequence of these new measurements is that the EKB flux is much more gravitationally focused than the cometary case because it is isotropic in the planet rather than the heliocentric frame. Thus, the lower velocities at infinity that characterize the EKB flux can increase the impact flux on the rings by a factor of ˜25. This means that even for the lower bound of the range of the newly measured flux, the amount of material hitting the rings may be considerably higher and thus the process of micrometeoroid bombardment and ballistic transport is likely even more influential in the rings' structural and compositional evolution over time. Here, we calculate the new EKB ejecta distribution using the model of Cuzzi and Durisen (1990) and compare this with the nominal cometary one, and then demonstrate using new simulations the consequences of the EKB flux on the evolution of ring composition and structure. The constraining of the micrometeoroid flux represents a very important step in being able to associate an absolute age for the rings. We argue that the new EKB flux poses a serious problem for "primordial" or "old" ring origin scenarios and favors more a scenario in which the rings, at least the way we see them today, cannot be much older than a few 100 Myrs.

  9. First light from a kilometer-baseline Scintillation Auroral GPS Array

    PubMed Central

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

    2015-01-01

    We introduce and analyze the first data from an array of closely spaced Global Positioning System (GPS) scintillation receivers established in the auroral zone in late 2013 to measure spatial and temporal variations in L band signals at 100–1000 m and subsecond scales. The seven receivers of the Scintillation Auroral GPS Array (SAGA) are sited at Poker Flat Research Range, Alaska. The receivers produce 100 s scintillation indices and 100 Hz carrier phase and raw in-phase and quadrature-phase samples. SAGA is the largest existing array with baseline lengths of the ionospheric diffractive Fresnel scale at L band. With an initial array of five receivers, we identify a period of simultaneous amplitude and phase scintillation. We compare SAGA power and phase data with collocated 630.0 nm all-sky images of an auroral arc and incoherent scatter radar electron precipitation measurements, to illustrate how SAGA can be used in multi-instrument observations for subkilometer-scale studies. Key Points A seven-receiver Scintillation Auroral GPS Array (SAGA) is now at Poker Flat, Alaska SAGA is the largest subkilometer array to enable phase/irregularities studies Simultaneous scintillation, auroral arc, and electron precipitation are observed PMID:26709318

  10. Photographer: JPL P-21741 BW Range: 2.6 million kilometers (1.6 million miles) This picture of Io,

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Photographer: JPL P-21741 BW Range: 2.6 million kilometers (1.6 million miles) This picture of Io, taken by Voyager 1, shows the region of the Jovian moon which will be monitored for volcanic eruptions by Voyager 2 during the 'Io movie' sequence. The white and orange patches probably are deposits of sulphur compounds and other volcanic materials. The Voyager 2 pictures of this region will be much more detailed.

  11. Photographer: JPL P-21741 C Range: 2.6 million kilometers (1.6 million miles) This picture of Io,

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Photographer: JPL P-21741 C Range: 2.6 million kilometers (1.6 million miles) This picture of Io, taken by Voyager 1, shows the region of the Jovian moon which will be monitored for volcanic eruptions by Voyager 2 during the 'Io movie' sequence. The white and orange patches probably are deposits of sulphur compounds and other volcanic materials. The Voyager 2 pictures of this region will be much more detailed.

  12. 24 CFR 100.20 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., and Secretary are defined in 24 CFR part 5. Aggrieved person includes any person who— (a) Claims to... Housing Act. Dwelling means any building, structure or portion thereof which is occupied as, or designed... in cases under title 11 U.S.C., receivers, and fiduciaries. Person in the business of selling...

  13. 50 CFR 20.100 - General provisions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... Migratory game bird population levels, including production and habitat conditions, vary annually. These... gathering programs to determine migratory game bird population status and trends, evaluations of habitat... PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Annual Seasons, Limits, and Shooting Hours Schedules §...

  14. 50 CFR 20.100 - General provisions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... Migratory game bird population levels, including production and habitat conditions, vary annually. These... gathering programs to determine migratory game bird population status and trends, evaluations of habitat... PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Annual Seasons, Limits, and Shooting Hours Schedules §...

  15. 50 CFR 20.100 - General provisions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... General provisions. (a) The taking, possession, transportation, and other uses of migratory game birds by.... Migratory game bird population levels, including production and habitat conditions, vary annually. These... migratory game birds to permissible levels. (b) The development of these schedules involves annual...

  16. 50 CFR 20.100 - General provisions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... General provisions. (a) The taking, possession, transportation, and other uses of migratory game birds by.... Migratory game bird population levels, including production and habitat conditions, vary annually. These... migratory game birds to permissible levels. (b) The development of these schedules involves annual...

  17. 'Everest' Panorama; 20-20 Vision

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] 'Everest' Panorama 20-20 Vision (QTVR)

    [figure removed for brevity, see original site] 'Everest' Panorama Animation

    If a human with perfect vision donned a spacesuit and stepped onto the martian surface, the view would be as clear as this sweeping panorama taken by NASA's Mars Exploration Rover Spirit. That's because the rover's panoramic camera has the equivalent of 20-20 vision. Earthlings can take a virtual tour of the scenery by zooming in on their computer screens many times to get a closer look at, say, a rock outcrop or a sand drift, without losing any detail. This level of clarity is unequaled in the history of Mars exploration.

    It took Spirit three days, sols 620 to 622 (Oct. 1 to Oct. 3, 2005), to acquire all the images combined into this mosaic, called the 'Everest Panorama,' looking outward in every direction from the true summit of 'Husband Hill.' During that period, the sky changed in color and brightness due to atmospheric dust variations, as shown in contrasting sections of this mosaic. Haze occasionally obscured the view of the hills on the distant rim of Gusev Crater 80 kilometers (50 miles) away. As dust devils swooped across the horizon in the upper right portion of the panorama, the robotic explorer changed the filters on the camera from red to green to blue, making the dust devils appear red, green, and blue. In reality, the dust devils are similar in color to the reddish-brown soils of Mars. No attempt was made to 'smooth' the sky in this mosaic, as has been done in other panoramic-camera mosaics to simulate the view one would get by taking in the landscape all at once. The result is a sweeping vista that allows viewers to observe weather changes on Mars.

    The summit of Husband Hill is a broad plateau of rock outcrops and windblown drifts about 100 meters (300 feet) higher than the surrounding plains of Gusev Crater. In the distance, near the center of the mosaic, is

  18. De-biased populations of Kuiper belt objects from the deep ecliptic survey

    SciTech Connect

    Adams, E. R.; Benecchi, S. D.; Gulbis, A. A. S.; Elliot, J. L.; Buie, M. W.; Trilling, D. E.; Wasserman, L. H.

    2014-09-01

    The Deep Ecliptic Survey (DES) was a survey project that discovered hundreds of Kuiper Belt objects from 1998 to 2005. Extensive follow-up observations of these bodies has yielded 304 objects with well-determined orbits and dynamical classifications into one of several categories: Classical, Scattered, Centaur, or 16 mean-motion resonances with Neptune. The DES search fields are well documented, enabling us to calculate the probability on each frame of detecting an object with its particular orbital parameters and absolute magnitude at a randomized point in its orbit. The detection probabilities range from a maximum of 0.32 for the 3:2 resonant object 2002 GF {sub 32} to a minimum of 1.5 × 10{sup –7} for the faint Scattered object 2001 FU {sub 185}. By grouping individual objects together by dynamical classes, we can estimate the distributions of four parameters that define each class: semimajor axis, eccentricity, inclination, and object size. The orbital element distributions (a, e, and i) were fit to the largest three classes (Classical, 3:2, and Scattered) using a maximum likelihood fit. Using the absolute magnitude (H magnitude) as a proxy for the object size, we fit a power law to the number of objects versus H magnitude for eight classes with at least five detected members (246 objects). The Classical objects are best fit with a power-law slope of α = 1.02 ± 0.01 (observed from 5 ≤ H ≤ 7.2). Six other dynamical classes (Scattered plus five resonances) have consistent magnitude distribution slopes with the Classicals, provided that the absolute number of objects is scaled. Scattered objects are somewhat more numerous than Classical objects, while there are only a quarter as many 3:2 objects as Classicals. The exception to the power law relation is the Centaurs, which are non-resonant objects with perihelia closer than Neptune and therefore brighter and detectable at smaller sizes. Centaurs were observed from 7.5 < H < 11, and that population is best

  19. Reality and origin of the Kernel of the classical Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Petit, J.-M.; Gladman, B.; Kavelaars, J. J.

    2012-04-01

    The Canada-France Ecliptic Plane Survey (CFEPS) obtained characterized observations of 321 sq.deg. of sky to depths in the range g=23.5--24.4 AB mag, providing a database of 169 trans-neptunian objects (TNOs) with high-precision dynamical classification and known discovery efficiency. Our data demand that the main classical Kuiper belt (a=40--47 AU) is represented by a `hot' population with a wide inclination distribution superposed on top of a `cold' population with narrow inclination component. With the qualifier that there will be mixing from the low-i tail from the hot component, we must split the `cold' population of the main classical belt into two sub-components to account the transition in the e/i distribution beyond a = 44.4 AU clearly visible in the data. The `stirred' population have orbits with a narrow-inclination distribution with semi-major axes starting at a=42.5 AU and extending to roughly 47 AU, with a range of eccentricities that increases with increasing a. There are more low-i and moderate-e TNOs per unit semimajor axis at a=44--44.5 AU than at smaller and larger semi-major axis, indicating that a third component is required. We thus insert a dense low-inclination concentration, which we call the `kernel', near a=44 AU to account for this intrinsic population. We favor the idea that this cold component is primordial. The primordial distance range of the cold population is difficult to constrain. The inner boundary at a=42.4 AU may have been eroded via scattering by massive bodies and resonance migration; any sequence of events cannot allow either the inner belt, or the mean-motion and secular resonances that probably migrated through it, to have preserved a cold component today. The coincidence of the stirred population's outer edge with the 2:1 resonance suggests to us that the kernel marks the original outer edge and that the larger-a cold objects have either (i) been dragged out of the a<44.4 AU region via trapping and then drop-off in the 2

  20. Experimentally determined volumetric properties of CO{sub 2} + CH{sub 4} + N{sub 2} mixtures at 20-100 MPa and 323-573 K. Chapter 3

    SciTech Connect

    Seitz, J.C.; Blencoe, J.G.; Bodnar, R.J.

    1994-12-31

    The densities of C0{sub 2}+CH{sub 4}+N{sub 2} mixtures were measured at 20--100 MPa, 323--573 K using a custom-designed high-pressure, high-temperature vibrating-tube densimeter. Molar volumes and excess molar volumes (V{sub m}{sup E}) were calculated from the experimental data. Although (V{sub m}{sup E}) is generally positive, negative deviations are observed in ternary mixtures with compositions close to those of binary mixtures that exhibit negative deviations. (V{sub m}{sup E}) generally decreases as pressure increases from 20 to 100 MPa. As temperature increases, (V{sub m}{sup E}) increases until it reaches a maximum around 473 K, and then it decreases moderately as temperature is further increased. (V{sub m}{sup E}) is typically between 0 and 4 per cent of the total volume of the mixture. Predictions of (V{sub m}{sup E}) for ternary mixtures may be made from experimental data for the binary subsystems. Comparison with experimental data indicates that these methods are reasonably accurate for predicting the volumetric properties of ternary gas mixtures.

  1. Atmospheric density variations at 140 kilometers deduced from precise satellite radar tracking data.

    NASA Technical Reports Server (NTRS)

    Devries, L. L.; Schusterman, L.; Bruce, R. W.

    1972-01-01

    Discussion of the technique of evaluating density values from precise radar-tracking data of satellites in the altitude region from 130 to 140 km. Inclinations of these satellites were between 106 and 112 deg. A detailed examination of all elements of the density-reduction techniques was conducted, and consideration was given to recent advances in geodesy, drag-coefficient modeling, and orbit-determination techniques. Ten days of high-resolution density data deduced from orbital decay of each of three satellites are presented. Three types of density variations at 140 km are discernible in these data: periodic daily density variations with a density amplitude of about 10%; density increases of up to 35% associated with enhanced geomagnetic activity during which the planetary geomagnetic index Kp reached a value of 8 units; and an observed semiannual variation of about 20%, which indicates a total semiannual variation of 35 to 40%.

  2. A perceptual channel for information transfer over kilometer distances Historical perspective and recent research. [extrasensory perception

    NASA Technical Reports Server (NTRS)

    Puthoff, H. E.; Targ, R.

    1976-01-01

    For more than 100 years, scientists have attempted to determine the truth or falsity of claims for the existence of a perceptual channel whereby certain individuals are able to perceive and describe remote data not presented to any known sense. This paper presents an outline of the history of scientific inquiry into such so-called paranormal perception and surveys the current state of the art in parapsychological research in the United States and abroad. The nature of this perceptual channel is examined in a series of experiments carried out in the Electronics and Bioengineering Laboratory of Stanford Research Institute. The perceptual modality most extensively investigated is the ability of both experienced subjects and inexperienced volunteers to view, by innate mental processes, remote geographical or technical targets including buildings, roads, and laboratory apparatus. The accumulated data indicate that the phenomenon is not a sensitive function of distance, and Faraday cage shielding does not in any apparent way degrade the quality and accuracy of perception. On the basis of this research, some areas of physics are suggested from which a description or explanation of the phenomenon could be forthcoming.

  3. Impact of Universal Plasma and Energetic Particle Processes on Icy Bodies of the Kuiper Belt and the Oort Cloud

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

    Modeling of space plasma and energetic particle interactions with icy bodies of the outer solar system is simplified when there is commonality of the underlying source, acceleration, and transport processes in spatially distinct regions from the supersonic heliosphere through the heliosheath into the local interstellar medium (LISM). Current trends in the Voyager heliosheath measurements suggest strong commonality to processes in the LISM. The Fisk-Gloeckler "universal" spectrum at suprathermal energies apparently plays a strong role in coupling the plasma and high energy particle regimes in the spatial and energetic transitions from the outer heliosphere to the LISM. Dominant processes in consecutive energy regimes project to varying effects versus irradiation depth on exposed upper surfaces of airless small icy bodies and to upper atmospheres of larger bodies such as Titan and Pluto. Relative absence of the universal suprathermal spectrum in the mid-heliospheric region of the classical Kuiper Belt may profoundly affect surface color diversity of icy bodies in this region.

  4. On the use of Video Camera Systems in the Detection of Kuiper Belt Objects by Stellar Occultations

    NASA Astrophysics Data System (ADS)

    Subasinghe, Dilini

    2012-10-01

    Due to the distance between us and the Kuiper Belt, direct detection of Kuiper Belt Objects (KBOs) is not currently possible for objects less than 10 km in diameter. Indirect methods such as stellar occultations must be employed to remotely probe these bodies. The size, shape, as well as atmospheric properties and ring system information of a body (if any), can be collected through observations of stellar occultations. This method has been previously used with some success - Roques et al. (2006) detected 3 Trans-Neptunian objects; Schlichting et al. (2009) detected a single object in archival data. However, previous assessments of KBO occultation detection rates have been calculated only for telescopes - we extend this method to video camera systems. Building on Roques & Moncuquet (2000), we present a derivation that can be applied to any video camera system, taking into account camera specifications and diffraction effects. This allows for a determination of the number of observable KBO occultations per night. Example calculations are presented for some of the automated meteor camera systems currently in use at the University of Western Ontario. The results of this project will allow us to refine and improve our own camera system, as well as allow others to enhance their systems for KBO detection. Roques, F., Doressoundiram, A., Dhillon, V., Marsh, T., Bickerton, S., Kavelaars, J. J., Moncuquet, M., Auvergne, M., Belskaya, I., Chevreton, M., Colas, F., Fernandez, A., Fitzsimmons, A., Lecacheux, J., Mousis, O., Pau, S., Peixinho, N., & Tozzi, G. P. (2006). The Astronomical Journal, 132(2), 819-822. Roques, F., & Moncuquet, M. (2000). Icarus, 147(2), 530-544. Schlichting, H. E., Ofek, E. O., Wenz, M., Sari, R., Gal-Yam, A., Livio, M., Nelan, E., & Zucker, S. (2009). Nature, 462(7275), 895-897.

  5. Numerical Simulations Of Catastrophic Disruption Of Porous Bodies: Application To Dark-type Asteroids And Kuiper-belt Family Formation

    NASA Astrophysics Data System (ADS)

    Michel, Patrick; Jutzi, M.; Richardson, D. C.; Benz, W.

    2010-10-01

    Asteroids of dark (e.g. C, D) taxonomic classes as well as Kuiper Belt objects and comets are believed to have high porosity, not only in the form of large voids but also in the form of micro-pores. The presence of such microscale porosity introduces additional physics in the impact process. We have enhanced our 3D SPH hydrocode, used to simulate catastrophic breakups, with a model of porosity [1] and validated it at small scale by comparison with impact experiments on pumice targets [2]. Our model is now ready to be applied to a large range of problems. In particular, accounting for the gravitational phase of an impact, we can study the formation of dark-type asteroid families, such as Veritas, and Kuiper-Belt families, such as Haumea. Recently we characterized for the first time the catastrophic impact energy threshold, usually called Q*D, as a function of the target's diameter, porosity, material strength and impact speed [3]. Regarding the mentioned families, our preliminary results show that accounting for porosity leads to different outcomes that may better represent their properties and constrain their definition. In particular, for Veritas, we find that its membership may need some revision [4]. The parameter space is still large, many interesting families need to be investigated and our model will be applied to a large range of cases. PM, MJ and DCR acknowledge financial support from the French Programme National de Planétologie, NASA PG&G "Small Bodies and Planetary Collisions" and NASA under Grant No. NNX08AM39G issued through the Office of Space Science, respectively. [1] Jutzi et al. 2008. Icarus 198, 242-255; [2] Jutzi et al. 2009. Icarus 201, 802-813; [3] Jutzi et al. 2010. Fragment properties at the catastrophic disruption threshold: The effect of the parent body's internal structure, Icarus 207, 54-65; [4] Michel et al. 2010. Icarus, submitted.

  6. Successful 2,000-Kilometer International Transfer of an Infant Receiving Extracorporeal Membrane Oxygenation for Severe Respiratory Failure.

    PubMed

    Brown, Kilian; Dunne, Ben; Festa, Marino; La Hei, Erik; Karpelowsky, Jonathan; Dando, Hayden; Orr, Yishay

    2016-08-01

    There is minimal reported experience with long-range retrieval of pediatric patients receiving extracorporeal membrane oxygenation (ECMO) support. We report the case of a 10-month old boy with necrotizing staphylococcal pneumonia complicated by a bronchopleural fistula, who was successfully retrieved and transported while receiving ECMO to our unit in Sydney, Australia, from a referring hospital 2,000 kilometers away in the Pacific Islands. He was successfully weaned from ECMO to receive single-lung ventilation after 13 days, and he underwent surgical repair of his bronchopleural fistula through a thoracotomy 3 days after decannulation. He has made a full recovery.

  7. Successful 2,000-Kilometer International Transfer of an Infant Receiving Extracorporeal Membrane Oxygenation for Severe Respiratory Failure.

    PubMed

    Brown, Kilian; Dunne, Ben; Festa, Marino; La Hei, Erik; Karpelowsky, Jonathan; Dando, Hayden; Orr, Yishay

    2016-08-01

    There is minimal reported experience with long-range retrieval of pediatric patients receiving extracorporeal membrane oxygenation (ECMO) support. We report the case of a 10-month old boy with necrotizing staphylococcal pneumonia complicated by a bronchopleural fistula, who was successfully retrieved and transported while receiving ECMO to our unit in Sydney, Australia, from a referring hospital 2,000 kilometers away in the Pacific Islands. He was successfully weaned from ECMO to receive single-lung ventilation after 13 days, and he underwent surgical repair of his bronchopleural fistula through a thoracotomy 3 days after decannulation. He has made a full recovery. PMID:27449448

  8. Eltanin: Ground Truth for Kilometer-Sized Deep-Ocean Impacts (Invited)

    NASA Astrophysics Data System (ADS)

    Kyte, F. T.; Gersonde, R.; Kuhn, G.

    2009-12-01

    Deposits of the late Pliocene (2.5 Ma) Eltanin impact are unique in the known geological record. The only known example of a km-sized asteroid to impact a deep-ocean (5 km) basin, is the most meterorite-rich locality known on Earth. This was discovered as an Ir anomaly in sediments from three cores collected in the SE Pacific in 1965 by the USNS Eltanin. Subsequently, two expeditions of the R/V Polarstern in 1995 and 2001 have conducted geological and geophysical investigations in the impact region. An area of ~80,000 km2 has been mapped in some detail, and deposits from the impact are found in 23 cores spanning a region extending 660 (E-W) by 250 km (N-S). We find a central region 50 to 100 km across, near the Freeden Seamounts (57.3S, 90.5W), where sediments as old as Eocene have been ripped up (perhaps to basement) and redeposited by the impact into a chaotic mix of pebble to boulder-sized fragments. This is overlain by a fining upward sequence of sediments with laminations and some cross-bedding consistent with deposition in a high-energy flow regime. Near the top of this impact deposit, sub mm- to cm-sized meteoritic ejecta is mixed into the disturbed sediment. This ejecta is composed of 90% shock-melted asteroid and 10% unmelted meteorite fragments from the lo-metal mesosiderite asteroid. The amount of meteoritic ejecta in 13 cores from the central region record deposition of 3 to 50 kg of asteroid material per square meter. Km-sized impacts are fairly common on geological timescales, occurring a few times per m.y., so one or two other similar-sized, and several smaller projectiles likely hit the Pacific basin since the Late Pliocene. Undoubtedly, this is not the only such impact collected in deep-sea cores; it is unique only in that it has been recognized. Eltanin thus serves as type section for identifying ocean-impact deposits at other localities. Projectiles of this size cannot penetrate to the ocean floor and indeed there is no chemical evidence in the

  9. Properties of the +70 kilometers per second cloud toward HD 203664

    NASA Technical Reports Server (NTRS)

    Sembach, Kenneth R.

    1995-01-01

    I present high-resolution International Ultraviolet Explorer (IUE) spectra of the ultraviolet absorption in an intermediate-velocity interstellar cloud (nu(sub LSR) approximately equal to +70 km/s) toward HD 203664. The combined, multiple IUE images result in spectra with S/N = 15-40 and resolutions of approximately 20-25 km/s. The intermediate-velocity cloud absorption is present in ultraviolet lines of C II, C II(sup *), C IV, N I, O I, Mg I, Mg II, Al II, Al III, Si II, Si III, Si IV, S II, Cr II, Mn II, Fe II, and Zn II. The relative abundances of low-ionization species suggest an electron density of 0.15-0.34/cu cm and a temperature of 5300-6100 K in the neutral and weakly ionized gas. Given the presence of high-ionization gas tracers such as Si IV and C IV, ionized portions of the cloud probably contribute to the relatively large values of n(sub e) derived from measurements of the lower ionization species. The high-ionization species in the cloud have an abundance ratio, N(C IV)/N(Si IV) approximately equal to 4.5, similar to that inferred for collisionally ionized cloud interfaces at temperatures near 10(exp 5) K along other sight lines. When referenced to sulfur, the abundances of most elements in the cloud are within a factor of 5 of their solar values, which suggests that the +70 km/s gas has a previous origin in the Galactic disk despite a recent determination by Little et al. that the cloud lies at a distance of 200-1500 pc below the Galactic plane. I have checked this result against a model of the ionization for the diffuse ionized gas layer of the Galaxy and find that this conclusion is essentially unchanged as long as the ionization parameter is low as implied by the abundances of adjoining ionization states of aluminum and silicon. The processes responsible for the production of highly ionized gas in the +70 km/s cloud appear to be able to account for the inferred dust grain destruction as well.

  10. The influence of breast support on torso, pelvis and arm kinematics during a five kilometer treadmill run.

    PubMed

    Milligan, Alexandra; Mills, Chris; Corbett, Jo; Scurr, Joanna

    2015-08-01

    Many women wear sports bras due to positive benefits associated with these garments (i.e. reduction in breast movement and breast pain), however the effects these garments have on upper body running kinematics has not been investigated. Ten female participants (32 DD or 34 D) completed two five kilometer treadmill runs (9 km h(-1)), once in a low and once in a high breast support. The range of motion (ROM) and peak torso, pelvis, and upper arm Cardan joint angles were calculated over five gait cycles during a five kilometer run. Peak torso yaw, peak rotation of the pelvis, peak pelvis obliquity, ROM in rotation of the pelvis, and ROM in upper arm extension were significant, but marginally reduced when participants ran in the high breast support. The running kinematics reported in the high breast support condition more closely align with economical running kinematics previously defined in the literature, therefore, running in a high breast support may be more beneficial to female runners, with a high breast support advocated for middle distance runners.

  11. Influence of injection mode on transport properties in kilometer-scale three-dimensional discrete fracture networks

    SciTech Connect

    Hyman, Jeffrey De'Haven; Painter, S. L.; Viswanathan, H.; Makedonska, N.; Karra, S.

    2015-09-12

    We investigate how the choice of injection mode impacts transport properties in kilometer-scale three-dimensional discrete fracture networks (DFN). The choice of injection mode, resident and flux-weighted, is designed to mimic different physical phenomena. It has been hypothesized that solute plumes injected under resident conditions evolve to behave similarly to solutes injected under flux-weighted conditions. Previously, computational limitations have prohibited the large-scale simulations required to investigate this hypothesis. We investigate this hypothesis by using a high-performance DFN suite, dfnWorks, to simulate flow in kilometer-scale three-dimensional DFNs based on fractured granite at the Forsmark site in Sweden, and adopt a Lagrangian approach to simulate transport therein. Results show that after traveling through a pre-equilibrium region, both injection methods exhibit linear scaling of the first moment of travel time and power law scaling of the breakthrough curve with similar exponents, slightly larger than 2. Lastly, the physical mechanisms behind this evolution appear to be the combination of in-network channeling of mass into larger fractures, which offer reduced resistance to flow, and in-fracture channeling, which results from the topology of the DFN.

  12. Influence of injection mode on transport properties in kilometer-scale three-dimensional discrete fracture networks

    DOE PAGESBeta

    Hyman, Jeffrey De'Haven; Painter, S. L.; Viswanathan, H.; Makedonska, N.; Karra, S.

    2015-09-12

    We investigate how the choice of injection mode impacts transport properties in kilometer-scale three-dimensional discrete fracture networks (DFN). The choice of injection mode, resident and flux-weighted, is designed to mimic different physical phenomena. It has been hypothesized that solute plumes injected under resident conditions evolve to behave similarly to solutes injected under flux-weighted conditions. Previously, computational limitations have prohibited the large-scale simulations required to investigate this hypothesis. We investigate this hypothesis by using a high-performance DFN suite, dfnWorks, to simulate flow in kilometer-scale three-dimensional DFNs based on fractured granite at the Forsmark site in Sweden, and adopt a Lagrangian approachmore » to simulate transport therein. Results show that after traveling through a pre-equilibrium region, both injection methods exhibit linear scaling of the first moment of travel time and power law scaling of the breakthrough curve with similar exponents, slightly larger than 2. Lastly, the physical mechanisms behind this evolution appear to be the combination of in-network channeling of mass into larger fractures, which offer reduced resistance to flow, and in-fracture channeling, which results from the topology of the DFN.« less

  13. Electroacupuncture-Like Stimulation at the Baihui (GV20) and Dazhui (GV14) Acupoints Protects Rats against Subacute-Phase Cerebral Ischemia-Reperfusion Injuries by Reducing S100B-Mediated Neurotoxicity

    PubMed Central

    Cheng, Chin-Yi; Lin, Jaung-Geng; Tang, Nou-Ying; Kao, Shung-Te; Hsieh, Ching-Liang

    2014-01-01

    Objectives The purpose of this study was to evaluate the effects of electroacupuncture-like stimulation at the Baihui (GV20) and Dazhui (GV14) acupoints (EA at acupoints) during the subacute phase of cerebral ischemia-reperfusion (I/R) injury and to establish the neuroprotective mechanisms involved in the modulation of the S100B-mediated signaling pathway. Methods The experimental rats were subjected to middle cerebral artery occlusion (MCAo) for 15 min followed by 1 d or 7 d of reperfusion. EA at acupoints was applied 1 d postreperfusion then once daily for 6 consecutive days. Results We observed that 15 min of MCAo caused delayed infarct expansion 7 d after reperfusion. EA at acupoints significantly reduced the cerebral infarct and neurological deficit scores. EA at acupoints also downregulated the expression of the glial fibrillary acidic protein (GFAP), S100B, nuclear factor-κB (NF-κB; p50), and tumor necrosis factor-α (TNF-α), and reduced the level of inducible nitric oxide synthase (iNOS) and apoptosis in the ischemic cortical penumbra 7 d after reperfusion. Western blot analysis showed that EA at acupoints significantly downregulated the cytosolic expression of phospho-p38 MAP kinase (p-p38 MAP kinase), tumor necrosis factor receptor type 1-associated death domain (TRADD), Fas-associated death domain (FADD), cleaved caspase-8, and cleaved caspase-3 in the ischemic cortical penumbra 7 d after reperfusion. EA at acupoints significantly reduced the numbers of GFAP/S100B and S100B/nitrotyrosine double-labeled cells. Conclusion Our study results indicate that EA at acupoints initiated 1 d postreperfusion effectively downregulates astrocytic S100B expression to provide neuroprotection against delayed infarct expansion by modulating p38 MAP kinase-mediated NF-κB expression. These effects subsequently reduce oxidative/nitrative stress and inhibit the TNF-α/TRADD/FADD/cleaved caspase-8/cleaved caspase-3 apoptotic pathway in the ischemic cortical penumbra 7 d

  14. The densities of halite-saturated WIPP-A and NBT-6 brines and their NaCl contents in weight percent, molal, and molar units from 20 to 100 degrees C

    USGS Publications Warehouse

    Chou, I-Ming; Buizinga, B.; Clynne, M.A.; Potter, R.W.

    1982-01-01

    A series of density measurements has been performed at 30?, 50?, 70?, and 90?C for halite-undersaturated WIPP-A and NBT-6 brines with various NaCl contents approaching saturation. The densities of halite-saturated WIPP-A and NBT-6 brines were obtained by extrapolating these measured densities to halite saturation points. The maximum difference between the densities obtained in this Fashion and those calculated from the model of Potter and Haas is 0.015 g/cm3. The NaCl contents in halite-saturated WIPP-A and NBT-6 brines are reported in wt %, molal, and molar units from 20? to 100?C.

  15. Non-isothermal decomposition kinetics, heat capacity and thermal safety of 37.2/44/16/2.2/0.2/0.4-GAP/CL-20/Al/N-100/PCA/auxiliaries mixture.

    PubMed

    Zhang, Jiao-Qiang; Gao, Hong-Xu; Ji, Tie-Zheng; Xu, Kang-Zhen; Hu, Rong-Zu

    2011-10-15

    The specific heat capacity (C(p)) of 37.2/44/16/2.2/0.2/0.4-GAP/CL-20/Al/N-100/PCA/auxiliaries mixture was determined with the continuous C(p) mode of microcalorimeter. The equation of C(p) with temperature was obtained. The standard molar heat capacity of GAP/CL-20/Al/N-100/PCA/auxiliaries mixture was 1.225 J mol(-1)K(-1) at 298.15K. With the help of the peak temperature (T(p)) from the non-isothermal DTG curves of the mixture at different heating rates (β), the apparent activation energy (E(k) and E(o)) and pre-exponential constant (A(K)) of thermal decomposition reaction obtained by Kissinger's method and Ozawa's method. Using density (ρ) and thermal conductivity (λ), the decomposition heat (Q(d), taking half-explosion heat), Zhang-Hu-Xie-Li's formula, the values (T(e0) and T(p0)) of T(e) and T(p) corresponding to β → 0, thermal explosion temperature (T(be) and T(bp)), adiabatic time-to-explosion (t(TIad)), 50% drop height (H(50)) of impact sensitivity, and critical temperature of hot-spot initiation (T(cr,hot spot)) of thermal explosion of the mixture were calculated. The following results of evaluating the thermal safety of the mixture were obtained: T(be) = 441.64K, T(bp) = 461.66 K, t(Tlad) = 78.0 s (n = 2), t(Tlad) = 74.87 s (n = 1), t(Tlad) = 71.85 s (n = 0), H(50) = 21.33 cm. PMID:21820242

  16. Non-isothermal decomposition kinetics, heat capacity and thermal safety of 37.2/44/16/2.2/0.2/0.4-GAP/CL-20/Al/N-100/PCA/auxiliaries mixture.

    PubMed

    Zhang, Jiao-Qiang; Gao, Hong-Xu; Ji, Tie-Zheng; Xu, Kang-Zhen; Hu, Rong-Zu

    2011-10-15

    The specific heat capacity (C(p)) of 37.2/44/16/2.2/0.2/0.4-GAP/CL-20/Al/N-100/PCA/auxiliaries mixture was determined with the continuous C(p) mode of microcalorimeter. The equation of C(p) with temperature was obtained. The standard molar heat capacity of GAP/CL-20/Al/N-100/PCA/auxiliaries mixture was 1.225 J mol(-1)K(-1) at 298.15K. With the help of the peak temperature (T(p)) from the non-isothermal DTG curves of the mixture at different heating rates (β), the apparent activation energy (E(k) and E(o)) and pre-exponential constant (A(K)) of thermal decomposition reaction obtained by Kissinger's method and Ozawa's method. Using density (ρ) and thermal conductivity (λ), the decomposition heat (Q(d), taking half-explosion heat), Zhang-Hu-Xie-Li's formula, the values (T(e0) and T(p0)) of T(e) and T(p) corresponding to β → 0, thermal explosion temperature (T(be) and T(bp)), adiabatic time-to-explosion (t(TIad)), 50% drop height (H(50)) of impact sensitivity, and critical temperature of hot-spot initiation (T(cr,hot spot)) of thermal explosion of the mixture were calculated. The following results of evaluating the thermal safety of the mixture were obtained: T(be) = 441.64K, T(bp) = 461.66 K, t(Tlad) = 78.0 s (n = 2), t(Tlad) = 74.87 s (n = 1), t(Tlad) = 71.85 s (n = 0), H(50) = 21.33 cm.

  17. Enhanced therapeutic anti-inflammatory effect of betamethasone upon topical administration with low frequency, low intensity (20 kHz, 100 mW/cm2) ultrasound exposure on carrageenan-induced arthritis in mice model

    PubMed Central

    Cohen, Gadi; Natsheh, Hiba; Sunny, Youhan; Bawiec, Christopher R.; Touitou, Elka; Lerman, Melissa A.; Lazarovici, Philip; Lewin, Peter A.

    2015-01-01

    The purpose of this work was to investigate whether low frequency, low intensity (LFLI, 20 kHz, <100 mW/cm2, spatial-peak, temporal-peak) ultrasound (US), delivered by a light-weight (<100g), tether-free, fully wearable, battery powered applicator is capable of reducing inflammation in a mouse model of Rheumatoid Arthritis (RA). The therapeutic, acute, anti-inflammatory effect was estimated by the relative swelling induced in mice hind limb paws. In an independent, indirect approach, the inflammation was bio-imaged by measuring glycolytic activity with near infrared labeled 2-deoxy-glucose (2DG). The outcome of the experiments indicated that the combination of US exposure with topical application of 0.1% w/w betamethasone gel, exhibited statistically significant (p<0.05) enhanced anti-inflammatory properties in comparison with the drug or US treatment alone. The present study underscores the potential benefits of LFLI US assisted drug delivery. However, the proof of concept presented indicates the need for additional experiments to systematically evaluate and optimize the potential of, and the conditions for, safe, LFLI ultrasound promoted non-invasive drug delivery. PMID:26003010

  18. THE TAOS PROJECT: UPPER BOUNDS ON THE POPULATION OF SMALL KUIPER BELT OBJECTS AND TESTS OF MODELS OF FORMATION AND EVOLUTION OF THE OUTER SOLAR SYSTEM

    SciTech Connect

    Bianco, F. B.; Zhang, Z.-W.; King, S.-K.; Wang, J.-H.; Lee, T.; Lin, H.-C.; Lehner, M. J.; Mondal, S.; Giammarco, J.; Holman, M. J.; Alcock, C.; Coehlo, N. K.; Axelrod, T.; Byun, Y.-I.; Kim, D.-W.; Chen, W. P.; Cook, K. H.; Dave, R.; De Pater, I.; Lissauer, J. J.

    2010-04-15

    We have analyzed the first 3.75 years of data from the Taiwanese American Occultation Survey (TAOS). TAOS monitors bright stars to search for occultations by Kuiper Belt objects (KBOs). This data set comprises 5 x 10{sup 5} star hours of multi-telescope photometric data taken at 4 or 5 Hz. No events consistent with KBO occultations were found in this data set. We compute the number of events expected for the Kuiper Belt formation and evolution models of Pan and Sari, Kenyon and Bromley, Benavidez and Campo Bagatin, and Fraser. A comparison with the upper limits we derive from our data constrains the parameter space of these models. This is the first detailed comparison of models of the KBO size distribution with data from an occultation survey. Our results suggest that the KBO population is composed of objects with low internal strength and that planetary migration played a role in the shaping of the size distribution.

  19. A Novel Method for Measuring Carbon Dioxide Concentration From 0 to 2.5 Kilometers Above the Ground

    NASA Astrophysics Data System (ADS)

    Tennermann, J.; Helenelund, C.; Quire, C.

    2004-12-01

    This paper describes a combination of novel technologies that enable the collection of atmospheric data, including PTU, wind speed / direction, and carbon dioxide concentration, from ground level to a maximum of 2.5 kilometers height above the ground using temporarily placed equipment. The measurement platform is a portable, highly engineered tethered balloon system that is used to loft and recover one or more instrument packages at controlled ascent and descent rates into the atmospheric boundary layer. Carbon dioxide concentration is measured with a lightweight NDIR instrument that is diffusion aspirated, self contained, and requires only one watt of power for operation. A test flight of the system is described and atmospheric data from the flight is shown.

  20. Continuous gradient temperature Raman spectroscopy of the long chain polyunsaturated fatty acids docosapentaenoic (DPA, 22:5n-6) and docosahexaenoic (DHA; 22:6n-3) from -100 to 20° C

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    The structural, cognitive and visual development of the human brain and retina strictly require long-chain polyunsaturated fatty acids (LC-PUFA). Excluding water, the mammalian brain is about 60% lipid. One of the great unanswered questions with respect to biological science in general is the absolute necessity of the LC-PUFA docosahexaenoic acid (DHA; 22:6n-3) in these fast signal processing tissues. A lipid of the same chain length with just one less diene group, docosapentaenoic acid (DPA; 22:5n-6) 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 to Raman spectroscopy, providing a straightforward technique to identify molecular rearrangements that occur near and at phase transitions. Herein we apply GTRS to DPA, and DHA from -100 to 20°C. 20 Mb three-dimensional data arrays with 1°C increments and first/second derivatives allows complete assignment of solid, liquid and transition state vibrational modes, including low intensity/frequency vibrations that cannot be readily analyzed with conventional Raman. DPA and DHA show significant spectral changes with premelting (-33 and -60°C, respectively) and melting (-27 and -44°C, respectively). The CH2-(HC=CH)-CH2 moieties are not identical in the second half of the DHA and DPA structures. The DHA molecule contains major CH2 twisting (1265 cm-1) with no noticeable CH2 bending, consistent with a flat helical structure with small pitch. Further modeling of neuronal membrane phospholipids must take into account this structure for DHA, which would be configured parallel to the hydrophilic head group line.

  1. The "AS&U" 100

    ERIC Educational Resources Information Center

    Kennedy, Mike

    2006-01-01

    This article presents "American School & University's" 100 largest school districts in the U.S. The top 100 public school districts in the U.S. represent less than 1% of the more than 14,000 school districts, but in 2004-2005, they accounted for more than 20% of the nation's public school enrollment--10,795,068 students. The money spent by the 100

  2. Evidence for a distant unseen solar system planet: Assessing the observational biases in the extreme Kuiper belt population

    NASA Astrophysics Data System (ADS)

    Volk, Kathryn; Malhotra, Renu

    2016-10-01

    Several recent studies have appealed to peculiarities in the observed distribution of very distant, extreme Kuiper belt objects (eKBOs) to argue for the existence of an Earth-mass or larger planet in the distant solar system. Trujillo and Sheppard (2014) noted that the arguments of perihelion of the observed eKBOs cluster near 0, and Batygin & Brown (2016) noted that the eKBOs also have clustered orbit poles and eccentricity vectors (which result in clustered longitudes of perihelion and longitudes of ascending node). Both papers argue that observational biases are unlikely to explain the observed clustering. Because the observed population of eKBOs is far from complete, a thorough assessment of the observational biases in the population is warranted. Very accurate assessment of observational biases is only possible for objects discovered by well-characterized surveys, but the number of eKBOs found by such surveys is small. We instead use the set of observed KBOs in the Minor Planet Center catalog along with published survey pointings and limiting magnitudes to approximately reconstruct the biases in the observed eKBO population. We will report on the role of observational biases in either strengthening or weakening the case for a distant unseen planet in our solar system. This research was supported by NASA (grant NNX14AG93G).

  3. In search of a signature of binary Kuiper Belt Objects in the Pluto-Charon crater population

    NASA Astrophysics Data System (ADS)

    Zangari, Amanda Marie; Parker, Alex; Singer, Kelsi N.; Stern, S. Alan; Young, Leslie; Olkin, Catherine B.; Ennico, Kimberly; Weaver, Harold A.; New Horizons Geology, Geophysics and Imaging Science Theme Team

    2016-10-01

    In July 2015, New Horizons flew by Pluto and Charon, allowing mapping of the encounter hemisphere at high enough resolution to produce crater counts from the surfaces of the pair. We investigate the distribution of craters in search of a signature of binary impactors. The Kuiper Belt -- especially the cold classical region -- has a large fraction of binary objects, many of which are close-in, equal-mass binaries. We will present results on how the distribution of craters seen on Pluto and Charon compares to a random distribution of single body impactors on the surfaces of each. Examining the surfaces of Pluto and Charon proves challenging due to resurfacing, and the presence of tectonic and other geographic features. For example, the informally-named Cthulhu region is among the oldest on Pluto, yet it abuts a craterless region millions of years young. On Charon, chastmata divide the surface into regions informally named Vulcan Planum and Oz terra. In our statistics, we pay careful attention to the boundaries of where craters may appear, and the dependence of our results on crater size. This work was supported by NASA's New Horizons project.

  4. Modeling Kuiper belt objects Charon, Orcus and Salacia by means of a new equation of state for porous icy bodies

    NASA Astrophysics Data System (ADS)

    Malamud, Uri; Prialnik, Dina

    2015-01-01

    We use a one-dimensional adaptive-grid thermal evolution code to model Kuiper belt objects Charon, Orcus and Salacia and compare their measured bulk densities with those resulting from evolutionary calculations at the end of 4.6 Gyr. Our model assumes an initial homogeneous composition of mixed ice and rock, and follows the multiphase flow of water through the porous rocky medium, consequent differentiation and aqueous chemical alterations in the rock. Heating sources include long-lived radionuclides, serpentinization reactions, release of gravitational potential energy due to compaction, and crystallization of amorphous ice. The density profile is calculated by assuming hydrostatic equilibrium to be maintained through changes in composition, pressure and temperature. To this purpose, we construct an equation of state suitable for porous icy bodies with radii of a few hundred km, based on the best available empirical studies of ice and rock compaction, and on comparisons with rock porosities in Earth analog and Solar System silicates. We show that the observed bulk densities can be reproduced by assuming the same set of initial and physical parameters, including the same rock/ice mass ratio for all three bodies. We conclude that the mass of the object uniquely determines the evolution of porosity, and thus explains the observed differences in bulk density. The final structure of all three objects is differentiated, with an inner rocky core, and outer ice-enriched mantle. The degree of differentiation, too, is determined by the object's mass.

  5. Electron Irradiation of Kuiper Belt Surface Ices: Ternary N2-CH4-CO Mixtures as a Case Study

    NASA Astrophysics Data System (ADS)

    Kim, Y. S.; Kaiser, R. I.

    2012-10-01

    The space weathering of icy Kuiper Belt Objects was investigated in this case study by exposing methane (CH4) and carbon monoxide (CO) doped nitrogen (N2) ices at 10 K to ionizing radiation in the form of energetic electrons. Online and in situ Fourier transform infrared spectroscopy was utilized to monitor the radiation-induced chemical processing of these ices. Along with isocyanic acid (HNCO), the products could be mainly derived from those formed in irradiated binary ices of the N2-CH4 and CO-CH4 systems: nitrogen-bearing products were found in the form of hydrogen cyanide (HCN), hydrogen isocyanide (HNC), diazomethane (CH2N2), and its radical fragment (HCN2); oxygen-bearing products were of acetaldehyde (CH3CHO), formyl radical (HCO), and formaldehyde (H2CO). As in the pure ices, the methyl radical (CH3) and ethane (C2H6) were also detected, as were carbon dioxide (CO2) and the azide radical (N3). Based on the temporal evolution of the newly formed products, kinetic reaction schemes were then developed to fit the temporal profiles of the newly formed species, resulting in numerical sets of rate constants. The current study highlights important constraints on the preferential formation of isocyanic acid (HNCO) over hydrogen cyanide (HCN) and hydrogen isocyanide (HNC), thus guiding the astrobiological and chemical evolution of those distant bodies.

  6. OSSOS. II. A Sharp Transition in the Absolute Magnitude Distribution of the Kuiper Belt’s Scattering Population

    NASA Astrophysics Data System (ADS)

    Shankman, C.; Kavelaars, JJ.; Gladman, B. J.; Alexandersen, M.; Kaib, N.; Petit, J.-M.; Bannister, M. T.; Chen, Y.-T.; Gwyn, S.; Jakubik, M.; Volk, K.

    2016-02-01

    We measure the absolute magnitude, H, distribution, dN(H) ∝ 10αH, of the scattering Trans-Neptunian Objects (TNOs) as a proxy for their size-frequency distribution. We show that the H-distribution of the scattering TNOs is not consistent with a single-slope distribution, but must transition around Hg ˜ 9 to either a knee with a shallow slope or to a divot, which is a differential drop followed by second exponential distribution. Our analysis is based on a sample of 22 scattering TNOs drawn from three different TNO surveys—the Canada-France Ecliptic Plane Survey, Alexandersen et al., and the Outer Solar System Origins Survey, all of which provide well-characterized detection thresholds—combined with a cosmogonic model for the formation of the scattering TNO population. Our measured absolute magnitude distribution result is independent of the choice of cosmogonic model. Based on our analysis, we estimate that the number of scattering TNOs is (2.4-8.3) × 105 for Hr < 12. A divot H-distribution is seen in a variety of formation scenarios and may explain several puzzles in Kuiper Belt science. We find that a divot H-distribution simultaneously explains the observed scattering TNO, Neptune Trojan, Plutino, and Centaur H-distributions while simultaneously predicting a large enough scattering TNO population to act as the sole supply of the Jupiter-Family Comets.

  7. Final report on EURAMET key comparison EURAMET.M.M-K2.6 (1345) of mass standards of 100 mg, 2 g, 20 g, 500 g (sub-multiple of the kilogram)

    NASA Astrophysics Data System (ADS)

    Zelenka, Zoltan; Davidson, Stuart; Berry, James; Vámossy, Csilla

    2015-01-01

    This project was a European regional bilateral key comparison of stainless steel standards of 100 mg, 2 g, 20 g, and 500 g as a submultiple of the kilogram carried out under the auspices of EURAMET and designated project 1345. This comparison is also a KCDB Regional Key Comparison, registered as EURAMET.M.M-K2.6. The objectives of the comparison were to check the measurement capabilities in the field of mass of BEV and provide a basis for the review of new calibration measurement capabilities (CMC). Results are linked to the key comparison reference values of CCM.M-K2. BEV (Austria) was the pilot laboratory and the provider of the transfer standards. NPL provided the link to the CCM KC and MKEH collected the measurement data and helped to ensure impartiality. 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 CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  8. 21 CFR 100.100 - Misleading containers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (e.g., where some minimum package size is necessary to accommodate required food labeling (excluding... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Misleading containers. 100.100 Section 100.100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED)...

  9. 21 CFR 100.100 - Misleading containers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (e.g., where some minimum package size is necessary to accommodate required food labeling (excluding... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Misleading containers. 100.100 Section 100.100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED)...

  10. 21 CFR 100.100 - Misleading containers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (e.g., where some minimum package size is necessary to accommodate required food labeling (excluding... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Misleading containers. 100.100 Section 100.100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED)...

  11. 21 CFR 100.100 - Misleading containers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (e.g., where some minimum package size is necessary to accommodate required food labeling (excluding... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Misleading containers. 100.100 Section 100.100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED)...

  12. 21 CFR 100.100 - Misleading containers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (e.g., where some minimum package size is necessary to accommodate required food labeling (excluding... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Misleading containers. 100.100 Section 100.100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED)...

  13. Kuiper Prize Lecture - Present and past climates of the terrestrial planets

    SciTech Connect

    Pollack, J.B. )

    1991-06-01

    An evaluation is undertaken of the current understanding of factors shaping the current climates of Venus, Mars, and the earth, in conjunction with the ways in which these planetary climates may have been different in the past. Attention is given to modeling approaches of various levels of sophistication which both characterize current climates and elucidate prior climatic epochs; these are assessed in light of observational data in order to judge degrees of success thus far and formulate major remaining questions for future investigations. Venus is noted to offer excellent opportunities for modeling the greenhouse effect. 100 refs.

  14. Defect induced mobility enhancement: Gadolinium oxide (100) on Si(100)

    SciTech Connect

    Sitaputra, W.; Tsu, R.

    2012-11-26

    Growth of predominantly single crystal (100)-oriented gadolinium oxide (Gd{sub 2}O{sub 3}) on a p-type Si(100) and growth of a polycrystal with a predominant Gd{sub 2}O{sub 3}(100) crystallite on a n-type Si(100) was performed using molecular beam epitaxy. Despite a poorer crystal structure than Gd{sub 2}O{sub 3}(110), an enhancement in carrier mobility can be found only from the Gd{sub 2}O{sub 3}(100)/n-type Si(100) interface. The mobility of 1715-1780 cm{sup 2}/V {center_dot} s was observed at room temperature, for carrier concentration >10{sup 20} cm{sup -3}. This accumulation of the electrons and the mobility enhancement may arise from the two-dimensional confinement due to charge transfer across the interface similar to transfer doping.

  15. The structure of the distant Kuiper belt in a Nice model scenario

    NASA Astrophysics Data System (ADS)

    Pike, Rosemary E.; Lawler, Samantha; Brasser, Ramon; Shankman, Cory; Alexandersen, Mike; Kavelaars, J. J.

    2016-10-01

    By utilizing a well-sampled migration model and characterized survey detections, we demonstrate that the Nice-model scenario results in consistent populations of scattering trans-Neptunian objects (TNOs) and several resonant TNO populations, but fails to reproduce the large population of 5:1 resonators discovered in surveys. We examine in detail the TNO populations implanted by the Nice model simulation from Brasser and Morbidelli (2013, B&M). This analysis focuses on the region from 25-155 AU, probing the classical, scattering, detached, and major resonant populations. Additional integrations were necessary to classify the test particles and determine population sizes and characteristics. The classified simulation objects are compared to the real TNOs from the Canada-France Ecliptic Plane Survey (CFEPS), CFEPS high latitude fields, and the Alexandersen (2016) survey. These surveys all include a detailed characterization of survey depth, pointing, and tracking efficiency, which allows detailed testing of this independently produced model of TNO populations. In the B&M model, the regions of the outer Solar System populated via capture of scattering objects are consistent with survey constraints. The scattering TNOs and most n:1 resonant populations have consistent orbital distributions and population sizes with the real detections, as well as a starting disk mass consistent with expectations. The B&M 5:1 resonators have a consistent orbital distribution with the real detections and previous models. However, the B&M 5:1 Neptune resonance is underpopulated by a factor of ~100 and would require a starting proto-planetesimal disk with a mass of ~100 Earth masses. The large population in the 5:1 Neptune resonance is unexplained by scattering capture in a Nice-model scenario, however this model accurately produces the TNO subpopulations that result from scattering object capture and provides additional insight into sub-population orbital distributions.

  16. Matching magnetic trends and patterns across the Tintina fault, Alaska and Canada--evidence for offset of about 490 kilometers: Chapter C in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Canada--results of a 5-year project

    USGS Publications Warehouse

    Saltus, Richard W.; Gough, Larry P.; Day, Warren C.

    2007-01-01

    Magnetic anomaly patterns on opposite sides of the mapped Tintina fault in eastern Alaska and western Canada show an apparent offset of about 490 kilometers (km), probably of Eocene age. This estimate is compared with previous geologically based estimates of 400 to 430 km and paleomagnetically based estimates of more than 1,100 km. The apparent geophysical alignments have geologic implications that deserve further study.

  17. The Planet Mercury Surface Spectroscopy and Analysis from the Kuiper Airborne Observatory and Analysis and Modeling to Determine Surface Composition

    NASA Technical Reports Server (NTRS)

    Sprague, Ann

    1997-01-01

    We had two successful flights to observe Mercury from the Kuiper Airborne Observatory (KAO) using High-efficiency Infrared Faint-Object Grating Spectrograph (HIFOGS). Flights were May 8, 1995 (eastern elongation) and July 6, 1995 (western elongation) For the observations one half of the primary mirror was covered to prevent sunlight from entering the telescope. All equipment and the airplane and its crew performed well. These flights were historical firsts for the KAO and for spectroscopy of Mercury in that it was the first time any spectroscopic observations of Mercury from above the Earth's atmosphere had been made. It was the first time the KAO had been used to @bserve an object less than 30 degrees from the Sun. Upon completion of the basic data reduction it became obvious that extensive modeling and analysis would be required to understand the data. It took three years of a graduate student's time and part time the PI to do the thermal modeling and the spectroscopic analysis. This resulted in a lengthy publication. A copy of this publication is attached and has all the data obtained in both KAO flights and the results clearly presented. Notable results are: (1) The observations found an as yet unexplained 5 micron emission enhancement that we think may be a real characteristic of Mercury's surface but could have an instrumental cause; (2) Ground-based measurements or an emission maximum at 7.7 microns were corroborated. The chemical composition of Mercury's surface must be feldspathic in order to explain spectra features found in the data obtained during the KAO flights.

  18. The effect of Rayleigh-Taylor instabilities on the thickness of undifferentiated crust on Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Rubin, Mark E.; Desch, Steven J.; Neveu, Marc

    2014-07-01

    Previous calculations of the internal structure and thermal evolution of Kuiper Belt Objects (KBOs) by Desch et al. (Desch, S.J., Cook, J.C., Doggett, T.C., Porter, S.B. [2009]. Icarus 202, 694-714) have predicted that KBOs should only partially differentiate, with rock and ice separating into a rocky core and icy mantle, below an undifferentiated crust of ice and rock. This crust is thermally insulating and enhances the ability of subsurface liquid to persist within KBOs. A dense rock/ice layer resting on an icy mantle is gravitationally unstable and prone to Rayleigh-Taylor (RT) instabilities, and may potentially overturn. Here we calculate the ability of RT instabilities to act in KBOs, and determine the thickness of undifferentiated crusts. We have used previously calculated growth rates of the RT instability to determine the critical viscosity of ice needed for the RT instability to operate. We calculate the viscosity of ice at the cold temperatures and long timescales relevant to KBOs. We find that crustal overturn is only possible where the temperature exceeds about 150 K, and that RT instabilities cannot act on geological timescales within about 60 km of the surfaces of a KBO like Charon. Although this crustal thickness is less than the 85 km previously calculated by Desch et al. (Desch, S.J., Cook, J.C., Doggett, T.C., Porter, S.B. [2009]. Icarus 202, 694-714), it is still significant, representing ≈25% of the mass of the KBO. We conclude that while RT instabilities may act in KBOs, they do not completely overturn their crusts. We calculate that Saturn’s moon Rhea should only partially differentiate, resulting in a moment of inertia C/MR2≈0.38.

  19. The Effect Off Rayleigh-Taylor Instabilities On The Thickness Of Undifferentiated Crust On Kuiper Belt Objects Like Charon

    NASA Astrophysics Data System (ADS)

    Rubin, Mark

    In this thesis I model the thermal and structural evolution of Kuiper Belt Objects (KBOs) and explore their ability to retain undifferentiated crusts of rock and ice over geologic timescales. Previous calculations by Desch et al. (2009) predicted that initially homogenous KBOs comparable in size to Charon (R ~ 600 km) have surfaces too cold to permit the separation of rock and ice, and should always retain thick (≈ 85 km) crusts, despite the partial differentiation of rock and ice inside the body. The retention of a thermally insulating, undifferentiated crust is favorable to the maintenance of subsurface liquid and potentially cryovolcanism on the KBO surface. A potential objection to these models is that the dense crust of rock and ice overlying an ice mantle represents a gravitationally unstable configuration that should overturn by Rayleigh-Taylor (RT) instabilities. I have calculated the growth rate of RT instabilities at the ice-crust interface, including the effect of rock on the viscosity. I have identified a critical ice viscosity for the instability to grow significantly over the age of the solar system. I have calculated the viscosity as a function of temperature for conditions relevant to marginal instability. I find that RT instabilities on a Charon-sized KBO require temperatures T > 143 K. Including this effect in thermal evolution models of KBOs, I find that the undifferentiated crust on KBOs is thinner than previously calculated, only ≈ 50 km. While thinner, this crustal thickness is still significant, representing ≈ 25% of the KBO mass, and helps to maintain subsurface liquid throughout most of the KBO's history.

  20. A Radio Synoptic Survey Telescope for the Next Decade and Beyond: A Square-Kilometer Array Concept

    NASA Astrophysics Data System (ADS)

    Myers, Steven T.

    2007-12-01

    The "Radio Synoptic Survey Telescope” (RSST) is a concept being developed in the US, in collaboration with the International SKA partners, as a proposal for a mid-frequency Square Kilometer Array (SKA) . This poster presents a preliminary sketch of the concept meant to encourage community feedback. The RSST would have the sensitivity to detect HI in normal galaxies out to a redshift z>1.5 (requiring a "square kilometer” of collecting area or more). It would also have high continuum polarimetric sensitivity for deep imaging and AGN studies. The core frequency coverage is proposed to be 0.4-1.4 GHz to cover HI to z=2.5 (a "Hydrogen Cosmological Evolution Telescope") with the possibility of extension of the upper frequency limit to 3 GHz or higher (a "Gravity Astrophysics Telescope"). Evaluation and costing of the various options will be an area of focus in the next few years. The RSST would operate primarily in Synoptic Survey mode, with the majority of the observing time ( 75% or more) devoted to large surveys that scan the sky on day to week cadences. There would likely be 10%-25% of time available for follow-up targeted observations and general observer projects. Examples of key surveys include (but are not exclusive to): (1) Cosmological HI Large Deep Survey; (2) Deep Continuum Survey; and a (3) Transient Monitoring Program. These surveys would be largely commensal, and would consist of sub-surveys of different regions to different depths. Science targets include "billion galaxy” cosmological redshift surveys (e.g. Baryon Acoustic Oscillations for dark energy studies), HI evolution studies, rotation measure surveys, radio supernova and GRB searches, pulsar searches and studies, and the discovery of new phenomena. Preliminary designs are based on development underway by the US-SKA consortium, the International SKA, and the general US radio astronomy community.

  1. La estructura dinámica del cinturón de Kuiper interior y la formación de Urano y Neptuno

    NASA Astrophysics Data System (ADS)

    Melita, M. D.; Brunini, A.

    De acuerdo a los más recientes estudios sobre la formación de Urano y Neptuno, éstos podrían haber sufrido una importante migración radial hacia el exterior, debido al intercambio de momento angular con los planetesimales presentes en esa región durante las últimas etapas de la formación del Sistema Solar. Esta migración radial habría tenido importantes consecuencias sobre la presente estructura dinámica del cinturón cometario de Kuiper. Tal como lo reflejan las observaciones, la mayoría de los cuerpos observados en el cinturón de Kuiper se encuentran en resonancia de movimientos medios exteriores con Neptuno, hecho que también se refleja en la presente órbita de Plutón. En el presente trabajo se estudia tanto numérica como analíticamente la influencia de la variación de las masas de Urano y Neptuno durante el proceso de migración sobre las probabilidades de captura en algunas de las resonancias exteriores de Neptuno. Se estudia también la influencia de encuentros gravitacionales mutuos sobre la estabilidad de las órbitas resonantes. Este estudio ofrece argumentos de plausibilidad para explicar por qué ninguno de los objetos descubiertos en el cinturón de Kuiper se encontraría en la resonancia 2:1.

  2. Obtaining Seasonal Snow Surface Roughness from Sub-Millimeter to Kilometer Scale Using Plate Photography and Mobile Laser Scanning

    NASA Astrophysics Data System (ADS)

    Anttila, K.; Manninen, T.; Kukko, A.; Kaartinen, H.; Hakala, T.; Kaasalainen, S. M.; Karjalainen, T.; Lahtinen, P.; Krooks, A.; Siljamo, N.; Riihelä, A.

    2013-12-01

    Seasonal snow surface roughness affects the brightness of snow surface and through that the albedo of Earth. It also affects the satellite and radar data of snow surfaces and the wind near the surface. The roughness depends on the direction and distance measured. We have developed a plate-photography method for measuring microscale surface roughness at a resolution of 0.01 mm. The concept is similar to the plate photography method described in Manninen et al. 2012 that can be used to study scales from millimeter to 1-meter scale. Preliminary test measurements were made in different directions daily during one week at the beginning of April 2013. The results have been analysed using multiscale parameters derived from root mean square height (Manninen et al. 1997 &2003). The method proved to be a working concept. For scales longer than one meter we have developed a mobile laser scanning based method for obtaining snow surface roughness (Kukko et al. 2013). In this method we have mounted FGI ROAMER (Kukko et al. 2007) on a sledge driven by a snow mobile. Together these methods will provide means to measure snow surface roughness from sub-millimeter to kilometer scales. Kukko, A., K. Anttila, T. Manninen, H. Kaartinen and S. Kaasalainen (subm.), Snow surface roughness from mobile laser scanning data. Kukko, A., Andrei, C.-O., Salminen, V.-M., Kaartinen, H., Chen, Y., Rönnholm, P., Hyyppä, H., Hyyppä, J., Chen, R., Haggrén, H., Kosonen, I., and Capek K. Road Environment Mapping System of the Finnish Geodetic Institute - FGI Roamer, Int. Arch. Photogramm. Remote Sens., 36, 241-247, 2007. Manninen, A.T. (1997), Surface roughness of Baltic sea ice, Journal of Geophysical Research, Oceans, 102(C1), 1119 -1139. Manninen, A.T. (2003), Multiscale surface roughness description for scattering modeling of bare soil, Physica A, 319, 535 - 551. Manninen, T., K. Anttila, T. Karjalainen, and P. Lahtinen (2012), Automatic snow surface roughness estimation using digital photos

  3. DETECTING COLD GAS AT z = 3 WITH THE ATACAMA LARGE MILLIMETER/SUBMILLIMETER ARRAY AND THE SQUARE KILOMETER ARRAY

    SciTech Connect

    Obreschkow, D.; Heywood, I.; Rawlings, S.

    2011-12-10

    We forecast the abilities of the Atacama Large Millimeter/submillimeter Array (ALMA) and the Square Kilometer Array (SKA) to detect CO and H I emission lines in galaxies at redshift z = 3. A particular focus is set on Milky Way (MW) progenitors at z = 3 since their detection within 24 hr constitutes a key science goal of ALMA. The analysis relies on a semi-analytic model, which permits the construction of an MW progenitor sample by backtracking the cosmic history of all simulated present-day galaxies similar to the real MW. Results are as follows: (1) ALMA can best observe an MW at z = 3 by looking at CO(3-2) emission. The probability of detecting a random model MW at 3{sigma} in 24 hr using 75 km s{sup -1} channels is roughly 50%, and these odds can be increased by co-adding the CO(3-2) and CO(4-3) lines. These lines fall into ALMA band 3, which therefore represents the optimal choice toward MW detections at z = 3. (2) Higher CO transitions contained in the ALMA bands {>=}6 will be invisible, unless the considered MW progenitor coincidentally hosts a major starburst or an active black hole. (3) The high-frequency array of SKA, fitted with 28.8 GHz receivers, would be a powerful instrument for observing CO(1-0) at z = 3, able to detect nearly all simulated MWs in 24 hr. (4) H I detections in MWs at z = 3 using the low-frequency array of SKA will be impossible in any reasonable observing time. (5) SKA will nonetheless be a supreme H I survey instrument through its enormous instantaneous field of view (FoV). A one-year pointed H I survey with an assumed FoV of 410 deg{sup 2} would reveal at least 10{sup 5} galaxies at z = 2.95-3.05. (6) If the positions and redshifts of those galaxies are known from an optical/infrared spectroscopic survey, stacking allows the detection of H I at z = 3 in less than 24 hr.

  4. Latest Results from and Plans for the New Horizons Pluto-Kuiper Belt Mission

    NASA Astrophysics Data System (ADS)

    Weaver, Harold; Stern, Alan

    2016-07-01

    spacecraft remains healthy and was targeted toward the flyby of a small (~30-40 km) KBO in late-2015, enabling the study of an object (2014 MU69) in a completely different dynamical class (cold classical) than Pluto, if NASA approves an Extended Mission phase. In addition to the flyby of 2014 MU69 on 2019-Jan-01, the proposed Extended Mission would also include observations of more than 20 other KBOs at resolutions and geometries not feasible from Earth, and studies of the heliospheric plasma, neutral H and He, and the dust environment out to 50 AU from the Sun.

  5. Signal Coherence and Improved Bandwidth in Kilometer-Scale Water-Pipe Tilt-Meters for Monitoring Slow Earthquakes

    NASA Astrophysics Data System (ADS)

    Bilham, R.; Suszek, N.; Flake, R.; Szeliga, W.; Melbourne, T.

    2005-12-01

    Slow earthquakes have been detected by GPS networks in numerous subduction zones but signals are frequently close to detection levels. Although strain-meters and tilt-meters possess a thousandfold higher resolution (~ 1 nstrain & 1 nrad), noise levels in these instruments tend to be site specific and it is sometimes considered necessary to instal clusters to distinguish tectonic signal from local noise. This approach to strain measurement can more than double the cost of initial installation. We report here first results from a half-km-long water pipe tiltmeter in which a test for signal coherence is an inherent product of the geometry of the instrument. An appealing feature of water-pipe tiltmeters is that they cost 25% less than a borehole strain-meter, assume long good long term stability within days of installation, and unlike the decade-longevity of borehole systems, have an indefinite life span. In a Michelson tilt-meter, tilt of the earth's surface is manifest as a rise in water level at one end of the pipe and an equal and opposite reduction in water level at the other. In newly installed tiltmeters in the Cascadia region we have introduced a central transducer that effectively provides two 250-m-long independent measures of tilt in each 500 m long pipe, and hence a measure of signal coherence for little extra cost. Data from each sensor are telemetered via radio modem to a remote computer at rates of 1-6 samples/minute. Initial results from four 500 m long water pipes installed in the Cascadia region, reveal that a secular drift level of better than 0.1 microradian/yr is established within a week of installation and that the two half-tiltmeters track each other closely at all periods. Noise levels are frequency dependent and vary form 0.2 nrad at hourly periods to 100 nrad at yearly periods. Atmospheric and aperiodic ocean loading appears to be the largest souce of noise at periods of several days to weeks in the bandwidth where slow earthquakes are

  6. THE CANADA-FRANCE ECLIPTIC PLANE SURVEY-FULL DATA RELEASE: THE ORBITAL STRUCTURE OF THE KUIPER BELT

    SciTech Connect

    Petit, J.-M.; Rousselot, P.; Mousis, O.; Kavelaars, J. J.; Gladman, B. J.; Jones, R. L.; Van Laerhoven, C.; Parker, J. Wm.; Bieryla, A.; Nicholson, P.; Mars, G.; Marsden, B.; Ashby, M. L. N.; Taylor, M.; Bernabeu, G.; Benavidez, P.; Campo Bagatin, A.

    2011-10-15

    % confidence). We show how the CFEPS Survey Simulator can be used to compare a cosmogonic model for the orbital element distribution to the real Kuiper Belt.

  7. Statistical Characterization of Kilometer-Scale Topography of Volcanic Units In Daedalia Planum, Mars: New Results From MGS MOLA Data Analysis

    NASA Astrophysics Data System (ADS)

    Kreslavsky, M. A.; Head, J. W.

    2001-12-01

    Mars Orbiter Laser Altimeter (MOLA) onboard MGS spacecraft produced a large set of 300-m-spaced precise measurements of Mars surface elevation. We use this data set to study statistical characteristics of topography. We present new results on kilometer-scale topographic patterns of Daedalia Planum. For all MOLA profiles in the area 35S - 10S, 135W - 105W we calculated a characteristic of profile curvature at a set of baselines from 0.6 km to 10 km. For each cell of a grid covering the area under study we calculated the curvature-frequency distribution at each baseline. The width of the frequency distributions can be considered as a characteristic of roughness at a scale defined by the baseline length. The median curvature characterizes prevalence of convex or concave segments of the profiles. These parameters plotted within the grid form maps of kilometer-scale topographic patterns. Daedalia Planum is volcanic plain formed mainly by lava flows from Arsia Mons. Different generations of the lava flows display distinctively different kilometer-scale topographic patterns. Middle Amazonian flows (unit At5 according to USGS 1:15M geological map by D.H.Scott and K.L.Tanaka) are characterized by the steep increase of roughness at short baselines and by prevalence of convex profiles, while Late Hesperian flows (AHt3, Ht2, Ht1) are relatively rougher at longer baselines and often display prevalence of a concave relief. The roughness maps allow to accurately and reliably outline the units. High-resolution MOC images show high diversity of tens-meter-scale surface patterns within all units, as well as a systematic difference correlating with kilometer-scale topography pattern characteristics. MOC images show various buried and exhumed small-scale features in the areas and evidences for presence and erosion of surficial deposits of various thickness. The difference in kilometer-scale statistics of topography is probably controlled by the presence and characteristics of these

  8. The 100 People Project

    ERIC Educational Resources Information Center

    McLeod, Keri

    2007-01-01

    This article describes the 100 People Project and how the author integrates the project in her class. The 100 People Project is a nonprofit organization based in New York City. The organization poses the question: If there were only 100 people in the world, what would the world look like? Through the project, students were taught about ethics in…

  9. La distribución de objetos en el Cinturón de Kuiper y la posible existencia de un nuevo planeta en el Sistema Solar

    NASA Astrophysics Data System (ADS)

    Brunini, A.

    A pesar de que la capacidad observacional no lo limita, no se han descubierto objetos en el Cinturón de Kuiper más allá de las 50 AU. Recientemente, hemos propuesto que un embrión planetario originalmente formado en la región de Urano-Neptuno, y posteriormente migrado hacia distancias mayores a 50-60 AU, puede explicar este hecho. Presentamos simulaciones numéricas de acreción del Sistema Solar exterior que muestran cómo, naturalmente, podriamos esperar que un planeta de este tipo se encuentre actualmente en regiones distantes del sistema solar. Analizamos además la posibilidad de detectarlo con instrumentos actuales.

  10. Molecular Shocks Associated with Massive Young Stars: CO Line Images with a New Far-Infrared Spectroscopic Camera on the Kuiper Airborne Observatory

    NASA Technical Reports Server (NTRS)

    Watson, Dan M.

    1997-01-01

    Under the terms of our contract with NASA Ames Research Center, the University of Rochester (UR) offers the following final technical report on grant NAG 2-958, Molecular shocks associated with massive young stars: CO line images with a new far-infrared spectroscopic camera, given for implementation of the UR Far-Infrared Spectroscopic Camera (FISC) on the Kuiper Airborne Observatory (KAO), and use of this camera for observations of star-formation regions 1. Two KAO flights in FY 1995, the final year of KAO operations, were awarded to this program, conditional upon a technical readiness confirmation which was given in January 1995. The funding period covered in this report is 1 October 1994 - 30 September 1996. The project was supported with $30,000, and no funds remained at the conclusion of the project.

  11. The First High-phase Observations of a KBO: New Horizons Imaging of (15810) 1994 JR1 from the Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Porter, Simon B.; Spencer, John R.; Benecchi, Susan; Verbiscer, Anne J.; Zangari, Amanda M.; Weaver, H. A.; Lauer, Tod R.; Parker, Alex H.; Buie, Marc W.; Cheng, Andrew F.; Young, Leslie A.; Olkin, Cathy B.; Ennico, Kimberly; Stern, S. Alan; the New Horizons Science Team

    2016-09-01

    NASA’s New Horizons spacecraft observed (15810) 1994 JR1, a 3:2 resonant Kuiper belt object (KBO), using the LOng Range Reconnaissance Imager (LORRI) on 2015 November 2 from a distance of 1.85 au and again on 2016 April 7 from a distance of 0.71 au. These were the first close observations of any KBO other than Pluto. Combining ground-based and Hubble Space Telescope (HST) observations at small phase angles and the LORRI observations at higher phase angles, we produced the first disk-integrated solar phase curve of a typical KBO from α = 0.°6–58°. Observations at these geometries, attainable only from a spacecraft in the outer solar system, constrain surface properties such as macroscopic roughness and the single particle phase function. 1994 JR1 has a rough surface with a 37° ± 5° mean topographic slope angle and has a relatively rapid rotation period of 5.47 ± 0.33 hr. 1994 JR1 is currently 2.7 au from Pluto; our astrometric points enable high-precision orbit determination and integrations that show that it comes this close to Pluto every 2.4 million years (104 heliocentric orbits), causing Pluto to perturb 1994 JR1. During the November spacecraft observation, the KBO was simultaneously observed using HST in two colors, confirming its very red spectral slope. These observations have laid the groundwork for numerous potential future distant KBO observations in the New Horizons–Kuiper belt extended mission.

  12. The First High-phase Observations of a KBO: New Horizons Imaging of (15810) 1994 JR1 from the Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Porter, Simon B.; Spencer, John R.; Benecchi, Susan; Verbiscer, Anne J.; Zangari, Amanda M.; Weaver, H. A.; Lauer, Tod R.; Parker, Alex H.; Buie, Marc W.; Cheng, Andrew F.; Young, Leslie A.; Olkin, Cathy B.; Ennico, Kimberly; Stern, S. Alan; the New Horizons Science Team

    2016-09-01

    NASA’s New Horizons spacecraft observed (15810) 1994 JR1, a 3:2 resonant Kuiper belt object (KBO), using the LOng Range Reconnaissance Imager (LORRI) on 2015 November 2 from a distance of 1.85 au and again on 2016 April 7 from a distance of 0.71 au. These were the first close observations of any KBO other than Pluto. Combining ground-based and Hubble Space Telescope (HST) observations at small phase angles and the LORRI observations at higher phase angles, we produced the first disk-integrated solar phase curve of a typical KBO from α = 0.°6-58°. Observations at these geometries, attainable only from a spacecraft in the outer solar system, constrain surface properties such as macroscopic roughness and the single particle phase function. 1994 JR1 has a rough surface with a 37° ± 5° mean topographic slope angle and has a relatively rapid rotation period of 5.47 ± 0.33 hr. 1994 JR1 is currently 2.7 au from Pluto; our astrometric points enable high-precision orbit determination and integrations that show that it comes this close to Pluto every 2.4 million years (104 heliocentric orbits), causing Pluto to perturb 1994 JR1. During the November spacecraft observation, the KBO was simultaneously observed using HST in two colors, confirming its very red spectral slope. These observations have laid the groundwork for numerous potential future distant KBO observations in the New Horizons-Kuiper belt extended mission.

  13. CO detections and IRAS observations of bright radio spiral galaxies at cz equal or less than 9000 kilometers per second

    NASA Technical Reports Server (NTRS)

    Sanders, D. B.; Mirabel, I. F.

    1985-01-01

    CO emission has been detected from 20 of 21 bright radio spirals with strong extended nuclear sources, including the most distant (NGC 7674) and the most luminous (IC 4553 = Arp 220, NGC 6240) galaxies yet detected in CO. All of these galaxies are rich in molecular gas, with M total(H2) = 3 x 10 to the 8th - 2 x 10 to the 10th solar masses. IRAS observations show that they have a strong far-infrared (FIR) excess, with L(FIR)/L(B) approximately equal to 1-35 and L(FIR) (40-400 microns) approximately equal to 10 to the 10th - 10 to the 12th L solar masses. The primary luminosity source for these radio cores appears to be star formation in molecular clouds. A strong correlation is found between the FIR and extended 21 cm continuum flux, implying that the fraction of massive stars formed is independent of the star formation rate. The ratio L(FIR)/M(H2) provides a measure of the current rate of star formation, which is found to be a factor 3-20 larger in these galaxies than for the ensemble of molecular clouds in the Milky Way. At these rates their molecular gas will be depleted in about 10 to the 8th yr.

  14. A test of water vapor radiometer-based troposphere calibration using VLBI observations on a 21-kilometer baseline

    NASA Technical Reports Server (NTRS)

    Linfield, R. P.; Teitelbaum, L. P.; Skjerve, L. J.; Keihm, S. J.; Walter, S. J.; Mahoney, M. J.; Treuhaft, R. N.

    1995-01-01

    Simultaneous very long baseline interferometry (VLBI) and water vapor radiometer (WVR) measurements on a 21 km baseline showed that calibration by WVRs removed a significant fraction of the effect of tropospheric delay fluctuations for these experiments. From comparison of the residual delay variations within scans and between scans, the total tropospheric contribution t the delay residuals for each of the three 5 to 20 hour sessions was estimated as 1, 17, and 10%, with the first value being uncertain. The observed improvement in rms residual delay from WVR calibration during these three sessions was 4, 16, and 2%, respectively. The improvement is consistent with the estimated 2 to 3 mm path delay precision of current WVRs. The VLBI measurements, of natural radio sources, were conducted in April and May 1993 at Goldstone, California. Dual-frequency (2.3 and 8.4 GHz) observations were employed to remove the effects of charged particles from the data. Measurements with co-pointed WVRs, located within 50 m of the axis of each antenna, were performed to test the ability of the WVRs to calibrate line-of-sight path delays. Factors that made WVR performance assessment difficult included (1) the fact that the level of tropospheric fluctuations was smaller than is typical for Goldstone during these experiments and (2) VLBI delay variations on longer time scales (i.e., over multiple scans) contained uncalibrated instrumental effects (probably a result of slow temperature variations in the VLBI hardware) that were larger than the tropospheric effects.

  15. 11 CFR 100.91 - Recounts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... a Federal election, is not a contribution except that the prohibitions of 11 CFR 110.20 and part 114... Contributions § 100.91 Recounts. A gift, subscription, loan, advance, or deposit of money or anything of...

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  17. 11 CFR 100.82 - Bank loans.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 11 Federal Elections 1 2010-01-01 2010-01-01 false Bank loans. 100.82 Section 100.82 Federal... Contributions § 100.82 Bank loans. (a) General provisions. A loan of money to a political committee or a... prohibitions of 11 CFR 110.4, 110.20, part 114 and part 115; or (2) The lending institution making the loan...

  18. Science at 100 Tesla

    NASA Astrophysics Data System (ADS)

    Harrison, Neil

    2012-10-01

    Within the last year, Los Alamos National Labs produced magnetic fields of 100 tesla strength non-destructively for the first time. Fields of such a strength open up many new possibilities for condensed matter research. I will present some recent examples of condensed matter physics experiments performed in magnetic fields reaching 100 tesla, which includes recent work on high temperature superconductivity, magnetism and low dimensional materials.

  19. Search capability for {eta}{yields}{nu}{sub e,{tau}{nu}e,{tau}}decays in cubic-kilometer neutrino detectors

    SciTech Connect

    Fazely, A. R.; Gunasingha, R. M.; Imlay, R. L.; Muhammad, K. D.; Ter-Antonyan, S. V.; Xu, X.

    2010-06-01

    We investigate the discovery potential of cubic-kilometer neutrino observatories such as IceCube to set stringent limits on the forbidden decays {eta}{yields}{nu}{sub e{nu}e} and {eta}{yields}{nu}{sub {tau}{nu}{tau}.} The signatures for these decays are cascade events resulting from the charged-current reactions of {nu}{sub e}, {nu}{sub {tau},} {nu}{sub e}, and {nu}{sub {tau}}on nuclei in such detectors. Background cascade events are mainly due to {nu}{sub e}'s from atmospheric {mu}, K{sup +}, and K{sub S}{sup 0} decays and to a lesser extent from atmospheric {nu}{sub {mu}}neutral-current interactions with nuclei. A direct upper limit for the branching ratio {eta}{yields}{nu}{sub e,{tau}{nu}e,{tau}}of 6.1x10{sup -4} at 90% CL can be achieved.

  20. [The dynamics of the fungal mycelial content in the soils of stationary posts in a 30-kilometer zone around the Chernobyl Atomic Electric Power Station].

    PubMed

    Vasilevskaia, A I; Zhdanova, N N; Gavriliuk, V I

    1993-01-01

    The paper deals with mycobiota of radionuclide-polluted soils of seven stationary posts in the 30-kilometer zone of the Chernobyl NPP and one in the vicinities of Kiev (Feofaniia). The lengths of light-and dark-coloured fungal mycelium were determined in the soil under study by the method of membrane filters for 1987-1989. Data obtained have been analyzed with the account of the radioactivity level of the soil samples, season and depth of the sampling horizon. The dynamics of mycelium content in soils has been traced which evidences for its seasonal changes and prevalence of dark-pigmented mycelium at the beginning which then was changed by predominance of light-coloured mycelium. It is supposed that radioactive contamination of soil is one of considerable components of the whole complex of ecological factors which determine the dynamics of fungal mycelium content in soil.

  1. Interfacial Tension-Driven Differentiation-(ITDD) may result in a low-density central region inside kilometer-sized bodies

    NASA Astrophysics Data System (ADS)

    Arias, Francisco J.

    2016-03-01

    Interfacial Tension-Driven Differentiation, (ITDD), and its possible significance with regards to the interior structures of kilometer-sized bodies is discussed. Using a simple physical and geometrical model, an analytical expression for the conditions in which ITDD can occur is derived. It is shown that ITDD coupled with internal convection can lead to a counterintuitive result: that central regions may be less dense than outer regions in km-sized, initially melted bodies. ITDD offers an alternative explanation to the formation of microporosity inside of small bodies, (e.g. Churyumov-Gerasimenko-like objects), as well as macroporosity, which is suggested to occur in the interior of Mars' larger satellite Phobos, without recourse to rubble-pile models. Depending on the development of the velocity boundary layer at the solidification front, ITDD allows not just the possibility of central porosity, but also more complex scenarios, such as the formation of internal porosity rings.

  2. Status of aeromagnetic survey coverage of Yucca Mountain and vicinity to a radius of about 140 kilometers, southwestern Nevada and southeastern California, 1992

    SciTech Connect

    Sikora, R.F.; Ponce, D.A.; Oliver, H.W.

    1993-12-31

    Fifty aeromagnetic surveys in the southwestern part of Nevada and the southeastern part of California have been evaluated to assess the quality and coverage of aeromagnetic data within 140 kilometers (km) of a potential nuclear waste repository at Yucca Mountain, Nevada. The compilation shows that all the study area is covered by aeromagnetic surveys, but in some areas, particularly in the Death Valley region, new surveys flown with closer flight line spacing and lower elevations than the existing coverage are needed. In addition, the California part of the study area needs to be analytically continued downward to 305 meters (m) above ground level to provide a consistent data set for interpretation of subsurface geologic structures.

  3. AFR-100 safety analyses

    SciTech Connect

    Sumner, T.; Moisseytsev, A.; Wei, T. Y. C.

    2012-07-01

    The Advanced Fast Reactor-100 (AFR-100) is Argonne National Laboratory's 250 MWth metal-fueled modular sodium-cooled pool-type fast reactor concept. [1] A series of accident sequences that focused on the AFR-100's ability to provide protection against reactor damage during low probability accident sequences resulting from multiple equipment failures were examined. Protected and Unprotected Loss of Flow (PLOF and ULOF) and Unprotected Transient Over-Power (UTOP) accidents were simulated using the SAS4A/SASSYS-1 safety analysis code. The large heat capacity of the sodium in the pool-type reactor allows the AFR-100 to absorb large amounts of energy during a PLOF with relatively small temperature increases throughout the system. During a ULOF with a 25-second flow halving time, coolant and cladding temperatures peak around 720 deg. C within the first minute before reactivity feedback effects decrease power to match the flow. Core radial expansion and fuel Doppler provide the necessary feedback during the UTOP to bring the system back to critical before system temperatures exceed allowable limits. Simulation results indicate that adequate ULOF safety margins exist for the AFR-100 design with flow halving times of twenty-five seconds. Significant safety margins are maintained for PLOF accidents as well as UTOP accidents if a rod stop is used. (authors)

  4. 50 CFR 100.20 - Request for reconsideration.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... file a request for reconsideration with the Board. (c) To file a request for reconsideration, you must notify the Board in writing within sixty (60) days of the effective date or date of publication of the... provide the Board with sufficient narrative evidence and argument to show why the action by the...

  5. 50 CFR 100.20 - Request for reconsideration.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... file a request for reconsideration with the Board. (c) To file a request for reconsideration, you must notify the Board in writing within sixty (60) days of the effective date or date of publication of the... provide the Board with sufficient narrative evidence and argument to show why the action by the...

  6. 20 CFR 672.100 - What is YouthBuild?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... receive education services that may lead to either a high school diploma or General Educational... school drop outs and are either a member of a low-income family, a foster care youth, a youth offender, a... facilities, or in other high wage, high-demand jobs. The program also benefits the larger community...

  7. 20 CFR 672.100 - What is YouthBuild?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... receive education services that may lead to either a high school diploma or General Educational... school drop outs and are either a member of a low-income family, a foster care youth, a youth offender, a... facilities, or in other high wage, high-demand jobs. The program also benefits the larger community...

  8. 20 CFR 672.100 - What is YouthBuild?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... receive education services that may lead to either a high school diploma or General Educational... school drop outs and are either a member of a low-income family, a foster care youth, a youth offender, a... facilities, or in other high wage, high-demand jobs. The program also benefits the larger community...

  9. 20 CFR 1001.100 - Purpose and scope of subpart.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....S.C. 2001-2012, chapters 41 and 42, which require the Secretary of Labor to provide eligible... Vietnam era to job openings listed by Federal contractors pursuant to 38 U.S.C. 2012(a), and (3) Reporting of services provided to eligible veterans and eligible persons pursuant to 38 U.S.C. 2007(c) and...

  10. 20 CFR 641.100 - What does this part cover?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Subpart F of this part provides the rules for projects designed to assure second career training and the placement of eligible individuals into unsubsidized jobs in the private sector. (g) Subpart G of this...

  11. Science 100, 101.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education, Winnipeg.

    This teacher's manual is the approved provincial guide for grade 10 science in Manitoba schools. Part 1 (an overview) discusses rationale, learning theory/design, and goals/objectives for the curriculum; design of Science 100 and 101; effects of metric system on the curriculum; special needs students; and student evaluation. Part 2 discusses…

  12. 100 Essential Signs.

    ERIC Educational Resources Information Center

    Texas School for the Deaf, Austin.

    The booklet contains illustrations of 100 basic signs for use by school employees in working with the deaf. The signs were chosen for inclusion in the booklet by a committee which reviewed hundreds of signs and evaluated their importance in communicating with the deaf. The illustrations, taken in large part from the "Preferred Signs for…

  13. [100 years of ophthalmology].

    PubMed

    Nover, A

    1982-12-16

    100 years ago ophthalmology was already an own special sector of medicine. In 1850, when Hermann von Helmholtz invented the ophthalmoscope, the beginning of modern ophthalmology was established. The "Ophthalmologische Gesellschaft" was founded in 1863. From thereon major advances in all divisions of ophthalmology were achieved. Some outstanding personalities and highlights are mentioned.

  14. Science at 100 T

    SciTech Connect

    Harrison, Neil

    2012-06-01

    100 tesla fields are essential for answering many key questions in condensed matter: (1) Collapse of magnetic length crucial tool for understanding high Tc superconductors; (2) Field can also behave as 'negative pressure' in condensed matter; and (3) Field-tuned emergent phenomena involving commensurability effects.

  15. Tuskegee: 100 Years Later.

    ERIC Educational Resources Information Center

    Higgins, Renelda

    1981-01-01

    Reviews the history and accomplishments of Tuskegee Institute over the past 100 years. Highlights the role played by Booker T. Washington, and W. E. B. DuBois; discusses the career of the school's retiring president, Luther Foster. Provides information on the new president, Dr. Benjamin Payton, and discusses future directions for the college. (APM)

  16. 100 most powerful.

    PubMed

    Romano, Michael

    2002-08-26

    Compiling a list of the 100 Most Powerful People in Healthcare requires some contemplation. Exactly what is power in this industry? C. Thomas Smith, president and CEO of VHA, calls power simply "the ability to make a difference." The influential figures chosen by Modern Healthcare readers represent a broadly varied and diverse group of movers and shakers. But they share the ability to change things.

  17. SP-100 surety evaluation

    SciTech Connect

    Not Available

    1985-06-01

    This report describes surety evaluations conducted during GFY 1985 in support of the General Electric design for a Space Nuclear Power System - SP-100. Those surety evaluations address both safety and safeguards requirements, which are derived from OSNP-1 and supporting documents. The report includes results of neutronics (criticality) calculations performed by Los Alamos. The results have been benchmarked against independent calculations performed by General Electric with different codes. These comparisons show close agreement, and are summarized. Los Alamos has also provided specifications of explosion and fire environments, which have been used in evaluation of the GE SP-100 concept. Following the summary of key results, surety requirements are given and recommendations toward specification of requirements for later SP-100 project phases are presented. A conceptual design summary is presented. To establish a comprehensive background for surety evaluations, a reference mission profile and potential accidents for each phase of the mission are identified. The main body of the report addresses surety of the General Electric Thermoelectric Conversion design. GE has also developed a Stirling Engine concept, and performed comprehensive surety evaluations for it. These evaluations are reported.

  18. The Walkback Test: A Study to Evaluate Suit and Life Support System Performance Requirements for a 10 Kilometer Traverse in a Planetary Suit

    NASA Technical Reports Server (NTRS)

    Vos, Jessica R.; Gernhardt, Michael L.; Lee, Lesley

    2007-01-01

    As planetary suit and planetary life support systems develop, specific design inputs for each system relate to a presently unanswered question concerning operational concepts: What distance can be considered a safe walking distance for a suited EVA crew member exploring the surface of the Moon to "walk-back" to the habitat in the event of a rover breakdown, taking into consideration the planned EVA tasks as well as the possible traverse back to the habitat? It has been assumed, based on Apollo program experience, that 10 kilometers (6.2 mi) will be the maximum EVA excursion distance from the lander or habitat to ensure the crew member s safe return to the habitat in the event of a rover failure. To investigate the feasibility of performing a suited 10 km Walkback, NASA-JSC assembled a multi-disciplinary team to design and implement the Lunar Walkback Test . The test was designed not only to determine the feasibility of a 10 km excursion, but also to collect human performance, biomedical, and biomechanical data relevant to optimizing space suit design and life support system sizing. These data will also be used to develop follow-on studies to understand interrelationships of such key parameters as suit mass, inertia, suit pressure, and center of gravity (CG), and the respective influences of each on human performance.

  19. ELECTRON IRRADIATION OF KUIPER BELT SURFACE ICES: TERNARY N{sub 2}-CH{sub 4}-CO MIXTURES AS A CASE STUDY

    SciTech Connect

    Kim, Y. S.; Kaiser, R. I.

    2012-10-10

    The space weathering of icy Kuiper Belt Objects was investigated in this case study by exposing methane (CH{sub 4}) and carbon monoxide (CO) doped nitrogen (N{sub 2}) ices at 10 K to ionizing radiation in the form of energetic electrons. Online and in situ Fourier transform infrared spectroscopy was utilized to monitor the radiation-induced chemical processing of these ices. Along with isocyanic acid (HNCO), the products could be mainly derived from those formed in irradiated binary ices of the N{sub 2}-CH{sub 4} and CO-CH{sub 4} systems: nitrogen-bearing products were found in the form of hydrogen cyanide (HCN), hydrogen isocyanide (HNC), diazomethane (CH{sub 2}N{sub 2}), and its radical fragment (HCN{sub 2}); oxygen-bearing products were of acetaldehyde (CH{sub 3}CHO), formyl radical (HCO), and formaldehyde (H{sub 2}CO). As in the pure ices, the methyl radical (CH{sub 3}) and ethane (C{sub 2}H{sub 6}) were also detected, as were carbon dioxide (CO{sub 2}) and the azide radical (N{sub 3}). Based on the temporal evolution of the newly formed products, kinetic reaction schemes were then developed to fit the temporal profiles of the newly formed species, resulting in numerical sets of rate constants. The current study highlights important constraints on the preferential formation of isocyanic acid (HNCO) over hydrogen cyanide (HCN) and hydrogen isocyanide (HNC), thus guiding the astrobiological and chemical evolution of those distant bodies.

  20. The First High-Phase Observations of a KBO: New Horizons Imaging of (15810) 1994 JR 1 from the Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Porter, Simon; Spencer, John R.; Benecchi, Susan D.; Verbiscer, Anne J.; Zangari, Amanda Marie; Weaver, Harold A.; Lauer, Tod R.; Parker, Alex; Buie, Marc W.; Cheng, Andrew F.; Young, Leslie; Olkin, Catherine B.; Ennico, Kimberly; Stern, S. Alan; New Horizons Science Team

    2016-10-01

    (15810) 1994 JR1, a 3:2 resonant Kupier Belt Object (KBO), was observed by NASA's New Horizons spacecraft using the LOng Range Reconnaissance Imager (LORRI) on November 2, 2015 from a distance of 1.85 AU, and again on April 7, 2016 from a distance of 0.71 AU. These were the first close observations of any KBO other than Pluto, and the first ever of a small KBO at close range. Combining ground-based and HST observations at small phase angles and the LORRI observations at higher phase angles, we produced the first disk-integrated solar phase curve of a typical in-situ KBO from 0.6 to 58 degrees phase angle. Observations at these geometries, a range only attainable using a spacecraft in the outer Solar System, constrain surface properties such as macroscopic roughness and the single particle phase function. 1994 JR1 has a rough surface with a 37 +/- 5 degrees mean topographic slope angle and has a relatively rapid rotation period of 5.47 +/- 0.33 hours, with a lightcurve amplitude of 0.8 magnitudes from the spacecraft. 1994 JR1 is currently 2.7 AU from Pluto; our astrometric points enable high-precision orbit determination and integrations which show that it comes this close to Pluto every 2.4 million years (10,000 heliocentric orbits), causing Pluto to perturb 1994 JR1. During the November spacecraft observation, the KBO was simultaneously observed using the Hubble Space Telescope in two colors, confirming its very red spectral slope. These observations have laid the groundwork for numerous potential future distant KBO observations in the proposed New Horizons-Kuiper Belt Extended Mission.

  1. Lick optical spectra of quasar HS 1946+7658 at 10 kilometers per second resolution Lyman-alpha forest and metal absorption systems

    NASA Technical Reports Server (NTRS)

    Fan, Xiao-Ming; Tytler, David

    1994-01-01

    We present optical spectra of the most luminous known quasi stellar object (QSO) HS 1946+7658 (z(sub em) = 3.051). Our spectra have both full wavelength coverage, 3240-10570 A, and in selected regions, either high signal-to-noise ratio, SNR approximately equals 40-100, or unusually high approximately 10 km/sec resolution, and in parts of the Ly alpha forest and to the red of Ly alpha emission they are among the best published. We find 113 Ly alpha systems and six metal-line systems, three of which are new. The metal systems at z(sub abs) = 2.844 and 3.050 have complex velocity structure with four and three prominent components, respectively. We find that the system at z(sub abs) = 2.844 is a damped Ly alpha absorption (DLA) system, with a neutral hydrogen column density of log N(H I) = 20.2 +/- 0.4, and it is the cause of the Lyman limit break at lambda approximately equals 3520 A. We believe that most of the H I column density in this system is in z(sub abs) = 2.8443 component which shows the strongest low-ionization absorption lines. The metal abundance in the gas phase of the system is (M/H) approximately equals -2.6 +/- 0.3, with a best estimate of (M/H) = -2.8, with ionizaion parameter log gamma = -2.75, from a photoionization model. The ratios of the logarithmic abundances of C, O, Al, and Si are all within a factor of 2 of solar, which is important for two reasons. First, we believe that the gas abundances which we measure are close to the total abundances, because the ratio of aluminum to other elements is near cosmic, and Al is a refractory element which depletes very readily like chromium, in the interstellar medium. Second, we do not see the enhancement of O with respect to C of (O/C) approximately equals 0.5-0.9 reported in three partial Lyman limit systems by Reimers et al. (1992) and Vogel & Reimers (1993); we measure (O/C) = -0.06 for observed ions and (O/C) approximately equals 0.2 after ionization corrections, which is consistent with solar

  2. 100G Ethernet in the wild - first experiences

    NASA Astrophysics Data System (ADS)

    Hoeft, Bruno; Stoy, Robert; Schröder, Frank; Reymund, Aurelie; Niederberger, Ralf; Mextorf, Olaf; Werner, Sabine

    2011-12-01

    A 100 Gigabit Testbed was established in a collaboration of 6 partners. Three industry partners have contributed the fiber infrastructure, the DWDM equipment, as well as the required routers. 447 kilometer was the distance of the wide area testbed established in collaboration with the German NREN DFN between Karlsruhe Institute of Technology and Forschungszentrum Jülich Before starting, DFN assured the quality of the fiber infrastructure, the operation of the DWDM systems at both locations, as well as the connection of the routers to this WAN link with a bandwidth of 100GE. 12*10GE interfaces were available at each site for connecting the local testnodes to the routers. A monitoring and measurement framework was installed for recording the most important IP network performance metrics, among them the One Way Delay (OWD) and its Variation, Packet Loss and Packet Reordering. The delay measurements were conducted between the GPS time synchronized Hades[1]measurement nodes at each location. Additionally all relevant counters at the routers have been recorded using a SNMP based Network Manangement Station and supplemented special command line interface output gathering and parsing scripts. The interfaces statistics were stored in 60 second intervals. The aim of the testbed was to demonstrate a failure-free transmission of one or more IP datastreams over 100GE during the whole period of 4 weeks.This included the evaluation of the 100 Gbit/s optical transmission system, the 100GE interfaces between the routers and the optical system, and the evaluation of a sustained 100GE transmission as well as the evaluation of the use of 100GE in a production like environment. The evaluation included a circulated (in a routing loop) tunable load between 1 and 100 Gbit/s, measurement of transmission quality of TCP and UDP datastreams between the endsystems, measurements of one way latency, a ramping up data transmission from approx. 8 Gbit/s up to 96 Gbit/s.

  3. The SNL100-02 blade :

    SciTech Connect

    Griffith, Daniel

    2013-11-01

    A series of design studies are performed to investigate the effects of advanced core materials and a new core material strategy on blade weight and performance for large blades using the Sandia 100-meter blade designs as a starting point. The initial core material design studies were based on the SNL100-01 100- meter carbon spar design. Advanced core material with improved performance to weight was investigated with the goal to reduce core material content in the design and reduce blade weight. A secondary element of the core study was to evaluate the suitability of core materials from natural, regrowable sources such as balsa and recyclable foam materials. The new core strategy for the SNL100-02 design resulted in a design mass of 59 tons, which is a 20% reduction from the most recent SNL100-01 carbon spar design and over 48% reduction from the initial SNL100-00 all-glass baseline blade. This document provides a description of the final SNL100-02 design, includes a description of the major design modifications, and summarizes the pertinent blade design information. This document is also intended to be a companion document to the distribution of the NuMAD blade model files for SNL100-02 that are made publicly available.

  4. 11 CFR 100.82 - Bank loans.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... prohibitions of 11 CFR 110.4, 110.20, part 114 and part 115; or (2) The lending institution making the loan has... political committee in accordance with 11 CFR 104.3(a) and (d). (c) Endorsers and guarantors. Each endorser... the candidate's spouse, the provisions of 11 CFR 100.52(b)(4) shall apply. Any reduction in the...

  5. Covering the Last Kilometer: Using GIS to Scale-Up Voluntary Medical Male Circumcision Services in Iringa and Njombe Regions, Tanzania

    PubMed Central

    Mahler, Hally; Plotkin, Marya; Kulindwa, Yusuph; Greenberg, Seth; Mlanga, Erick; Njeuhmeli, Emmanuel; Lija, Gissenje

    2015-01-01

    Background: Based on the established protective effect of voluntary medical male circumcision (VMMC) in reducing female-to-male HIV transmission, Tanzania's Ministry of Health and Social Welfare (MOHSW) embarked on the scale-up of VMMC services in 2009. The Maternal and Child Health Integrated Project (MCHIP) supported the MOHSW to roll out VMMC services in Iringa and Njombe, 2 regions of Tanzania with among the highest HIV and lowest circumcision prevalence. With ambitious targets of reaching 264,990 males aged 10–34 years with VMMC in 5 years, efficient and innovative program approaches were necessary. Program Description: Outreach campaigns, in which mobile teams set up temporary services in facilities or non-facility settings, are used to reach lesser-served areas with VMMC. In 2012, MCHIP began using geographic information systems (GIS) to strategically plan the location of outreach campaigns. MCHIP gathered geocoded data on variables such as roads, road conditions, catchment population, staffing, and infrastructure for every health facility in Iringa and Njombe. These data were uploaded to a central database and overlaid with various demographic and service delivery data in order to identify the VMMC needs of the 2 regions. Findings: MCHIP used the interactive digital maps as decision-making tools to extend mobile VMMC outreach to “the last kilometer.” As of September 2014, the MOHSW with MCHIP support provided VMMC to 267,917 men, 259,144 of whom were men were aged 10–34 years, an achievement of 98% of the target of eligible males in Iringa and Njombe. The project reached substantially more men through rural dispensaries and non-health care facilities each successive year after GIS was introduced in 2012, jumping from 48% of VMMCs performed in rural areas in fiscal year 2011 to 88% in fiscal year 2012 and to 93% by the end of the project in 2014. Conclusion: GIS was an effective tool for making strategic decisions about where to prioritize VMMC

  6. Airborne 20-65 micron spectrophotometry of Comet Halley

    NASA Technical Reports Server (NTRS)

    Glaccum, William; Moseley, S. H.; Campins, Humberto C.; Loewenstein, R. F.

    1988-01-01

    Observations of Comet Halley with a grating spectrometer on board the Kuiper Airborne Observatory on four nights in Dec. 1985 to Apr. 1986 are reported. Low resolution 20 to 65 micrometer spectra of the nucleus with a 40 arcsec FWHM beam was obtained on 17 Dec. 1985, and on 15 and 17 Apr. 1986. On 20 Dec. 1985, only a 20 to 35 micrometer spectrum was obtained. Most of the data have been discussed in a paper where the continuum was dealt with. In that paper, models were fit to the continuum that showed that more micron sized particles of grain similar to amorphous carbon were needed to fit the spectrum than were allowed by the Vega SP-2 mass distribution, or that a fraction of the grains had to be made out of a material whose absorption efficiency fell steeper than lambda sup -1 for lambda greater than 20 micrometers. Spectra was also presented taken at several points on the coma on 15 Apr. which showed that the overall shape to the spectrum is the same in the coma. Tabulated values of the data and calibration curves are available. The spectral features are discussed.

  7. 100 Areas CERCLA ecological investigations

    SciTech Connect

    Landeen, D.S.; Sackschewsky, M.R.; Weiss, S.

    1993-09-01

    This document reports the results of the field terrestrial ecological investigations conducted by Westinghouse Hanford Company during fiscal years 1991 and 1992 at operable units 100-FR-3, 100-HR-3, 100-NR-2, 100-KR-4, and 100-BC-5. The tasks reported here are part of the Remedial Investigations conducted in support of the Comprehensive Environmental Response, compensation, and Liability Act of 1980 studies for the 100 Areas. These ecological investigations provide (1) a description of the flora and fauna associated with the 100 Areas operable units, emphasizing potential pathways for contaminants and species that have been given special status under existing state and/or federal laws, and (2) an evaluation of existing concentrations of heavy metals and radionuclides in biota associated with the 100 Areas operable units.

  8. {100}<100> or 45.degree.-rotated {100}<100>, semiconductor-based, large-area, flexible, electronic devices

    DOEpatents

    Goyal, Amit

    2012-05-15

    Novel articles and methods to fabricate the same resulting in flexible, {100}<100> or 45.degree.-rotated {100}<100> oriented, semiconductor-based, electronic devices are disclosed. Potential applications of resulting articles are in areas of photovoltaic devices, flat-panel displays, thermophotovoltaic devices, ferroelectric devices, light emitting diode devices, computer hard disc drive devices, magnetoresistance based devices, photoluminescence based devices, non-volatile memory devices, dielectric devices, thermoelectric devices and quantum dot laser devices.

  9. Depiction of Kuiper Belt World

    NASA Video Gallery

    Planets in our own solar system have a wide range of properties. They are distinguished by two basic properties, their size and their orbit. The size determines if the planet can have a life-sustai...

  10. The 20-20-20 Airship Challenge

    NASA Astrophysics Data System (ADS)

    Kiessling, Alina; Diaz, Ernesto; Miller, Sarah; Rhodes, Jason

    2014-06-01

    A NASA Centennial Challenge; (http://www.nasa.gov/directorates/spacetech/centennial_challenges/index.html) is in development to spur innovation in stratospheric airships as a science platform. We anticipate a million dollar class prize for the first organization to fly a powered airship that remains stationary at 20km (65,000 ft) altitude for over 20 hours with a 20kg payload. The design must be scalable to longer flights with more massive payloads.In NASA’s constrained budget environment, there are few opportunities for space missions in astronomy and Earth science, and these have very long lead times. We believe that airships (powered, maneuverable, lighter-than-air vehicles) could offer significant gains in observing time, sky and ground coverage, data downlink capability, and continuity of observations over existing suborbital options at competitive prices. We seek to spur private industry (or non-profit institutions, including FFRDCs and Universities) to demonstrate the capability for sustained airship flights as astronomy and Earth science platforms. This poster will introduce the challenge in development and provide details of who to contact for more information.

  11. Fire in the Land of 100,000 Lakes

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Fire season in Manitoba, Canada lasts from April until October, and numerous smoke plumes caused by lightning strikes are captured in these Multi-angle Imaging SpectroRadiometer (MISR) views of the northwestern part of the province. The data were acquired on June 20, 2001 during Terra orbit 8015.

    On the left is a true-color image acquired by MISR's vertical-viewing (nadir) camera. The area covered measures 232 kilometers X 80 kilometers. The greenish area on the right-hand side of the image, partially obscured by clouds, is Southern Indian Lake. This landscape is predominantly boreal, and contains deciduous and evergreen conifer forests, deciduous broadleaved forests, fens, and lakes. Tree species found within the area include white and black spruce, jack pine, tamarack, willow, and birch. Human population density is sparse, averaging about 1 person per 10 square kilometers.

    During the fire season, information is updated daily on the Manitoba Conservation website (http://www.gov.mb.ca/natres/fire/). The large plume northwest of Big Sand Lake, above image center, was reported to be under control on June 20, whereas the plume at lower left, to the west of Gold Sand Lake, was classified 'out of control.' In the next two days, an additional 27 out-of-control fires in the area were started by lightning strikes arriving with as low-moving northerly cold front. By June 29, all but six of the fires had been brought under control.

    The picture on the right is a height field derived using automated computer processing of the data from several of MISR's cameras. The results indicate that the smoke plumes reach altitudes a few kilometers above the surface terrain, nearly as high as the cumulus cloud field in the lower right quadrant. The height retrievals make use of geometric parallax associated with observing the features at multiple angles. A few artifacts are visible in this early version of the MISR stereoscopic product, e.g., linear discontinuities in the

  12. [Analysis of recessive sex-linked lethal mutations in genotypically different strains of Drosophila melanogaster MS and w, exposed in the 5-kilometer zone of the accident at the Chernobyl nuclear reactor].

    PubMed

    Aslanian, M M; Kim, A I; Magomedova, M A; Fatkulbaianova, N L

    1994-09-01

    The frequency of induced and spontaneous recessive sex-linked lethal mutations (RSLLM) in Drosophila melanogaster strains w and ms was estimated after their chronic irradiation in the five-kilometer zone of the Chernobyl' meltdown. The mutagenic effect of relatively low radiation doses was analyzed. In an experiment conducted in 1990, a significant increase in the RSLLM frequency was recorded, while, in 1991, no significant difference between the experiment and control was found.

  13. History of 100-B Area

    SciTech Connect

    Wahlen, R.K.

    1989-10-01

    The initial three production reactors and their support facilities were designated as the 100-B, 100-D, and 100-F areas. In subsequent years, six additional plutonium-producing reactors were constructed and operated at the Hanford Site. Among them was one dual-purpose reactor (100-N) designed to supply steam for the production of electricity as a by-product. Figure 1 pinpoints the location of each of the nine Hanford Site reactors along the Columbia River. This report documents a brief description of the 105-B reactor, support facilities, and significant events that are considered to be of historical interest. 21 figs.

  14. News and Views: Diamond is new head of SKA; Did you read our `A&G' mobile issue? BBC writer wins astro journalism prize; Kavli prize recognizes work on Kuiper Belt objects

    NASA Astrophysics Data System (ADS)

    2012-10-01

    Philip Diamond will become director general of the Square Kilometre Array this month, moving from Australia to the new SKA headquarters at Jodrell Bank Radio Observatory. Technology writer Katia Moskvitch has won the first European Astronomy Journalism Prize for her series of articles on the Very Large Telescope at Paranal, Chile. Moskvitch will be the guest of the ESO at the inauguration of the Atacama Large Millimeter/submillimeter Array (ALMA) in the Atacama desert in March 2013. The 2012 Kavli Prize in Astrophysics is shared between David C Jewitt (University of California, USA), Jane X Luu (Massachusetts Institute of Technology, Lincoln Laboratory, USA), and Michael E Brown (California Institute of Technology, USA) “for discovering and characterizing the Kuiper Belt and its largest members, work that led to a major advance in the understanding of the history of our planetary system”.

  15. Enzyme activity down to -100 degrees C.

    PubMed

    Bragger, J M; Dunn, R V; Daniel, R M

    2000-07-14

    The activities of two enzymes, beef liver catalase (EC 1.11.1.6) and calf intestine alkaline phosphatase (EC 3.1.3.1), have been measured down to -97 degrees C and -100 degrees C, respectively. Enzyme activity has not previously been measured at such low temperatures. For catalase, the cryosolvents used were methanol:ethylene glycol:water (70:10:20) and DMSO:ethylene glycol:water (60:20:20). For alkaline phosphatase, methanol:ethylene glycol:water (70:10:20) was used. All of the Arrhenius plots were linear over the whole of the temperature range examined. Since the lowest temperatures at which activity was measured are well below the dynamic transition observed for proteins, the results indicate that the motions which cease below the dynamic transition are not essential for enzyme activity. In all cases the use of cryosolvent led to substantial increases in Arrhenius activation energies, and this imposed practical limitations on the measurement of enzyme activity below -100 degrees C. At even lower temperatures, enzyme activity may be limited by the effect of solvent fluidity on substrate/product diffusion, but overall there is no evidence that any intrinsic enzyme property imposes a lower temperature limit for enzyme activity. PMID:10899628

  16. Kilometer-thick ice-sheets in the northern mid-latitudes of Mars in the Amazonian: Analogs from the East Antarctic Ice Sheet and the Dry Valleys

    NASA Astrophysics Data System (ADS)

    Head, James W.; Marchant, David R.

    2008-09-01

    involved ice sheets with thicknesses measured in hundreds of meters to several kilometers. Conclusions. Analysis of the distribution of glaciers and glacial deposits that formed during the build up, maturation (glacial overriding of km-high bedrock escarpments), and ultimate sublimation of Miocene-age cold-based glaciers in the Antarctic Dry Valleys (ADV) provides important insight into the interpretation of candidate glacial deposits along the martian dichotomy boundary [4,5]. These analogs strongly suggest that the dichotomy boundary was largely covered by a plateau icefield during parts of the Amazonian. Subsequently, recession caused bedrock to be exposed and debris-covered glaciers to form; the current LVF/LDA configuration represents the terminal stages of this phase. References. [1] J. Head and D. Marchant, Geology, 31, 641, 2003; [2] D. Shean et al., JGR, doi:10.1029/2004 JE002360, 2005; [3] J. Head et al., EPSL, 24, 663, 2006; J. Head et al., GRL, 33 L08S03, 2006; [4] J. Head and D. Marchant, LPSC 37, 1127, 2006; [5] D. Marchant and J. Head, LPSC 34, 1361, 2003; [6] D. Marchant and J. Head, LPSC 35, 1405, 2004; [7] G. Denton et al., Geografiska Annaler 75, 155-204, 1993; [8] D. Marchant et al., Geografiska Annaler 75, 269- 302, 1993; [9] J. Laskar et al., Icarus, 170, 343, 2004; [10] J. Fastook et al, LPSC 36, 1212, 2005; [11] D. Shean et al., LPSC 36, 1339, 2005; [12] D. Shean et al., LPSC 37, 2006; [13] D. Shean et al., LPSC 36, 2190, 2005; [14] D. Marchant et al., GSA Bull. 114, 718-730, 2002; [15] J. Dickson et al., Geology, 36, 411, 2008. [16] J Head et al., B-V Micro 46, 24, 2007.

  17. NETL: The First 100 Years

    SciTech Connect

    2015-07-21

    The National Energy Technology Laboratory celebrates 100 years of innovative energy technology development. NETL has been a leader in energy technology development. This video takes a look back at the many accomplishments over the past 100 years. These advances benefit the American people, enhance our nation's energy security and protect our natural resources.

  18. CV 100--Still Going Strong

    ERIC Educational Resources Information Center

    Abrahams, A. L.

    1976-01-01

    Describes results of a study that used CV 100, a fuel additive for use in oil-fired heating systems, on a trial basis in 12 Ontario schools. The test showed an average 12 percent reduction in fuel costs in the schools using CV 100. (JG)

  19. Six-degree-of-freedom missile simulation using the ADI AD 100 digital computer and ADSIM simulation language

    NASA Technical Reports Server (NTRS)

    Zwaanenburg, Koos

    1989-01-01

    The use of an AD 100 computer and the ADSIM language in the six-degree-of-freedom digital simulation of an air-to-ground missile is illustrated. The missile is launched from a moving platform, typically a helicopter, and is capable of striking a mobile target up to 10 kilometers away. The missile could be any tactical missile. The performance numbers of the AD 100 show that it is possible to implement a high performance missile model in a real-time simulation without the problems associated with an implementation on a general purpose computer using FORTRAN.

  20. 100. Historic American Buildings Survey COVERED WAY TO SECRETARY'S COTTAGE ...

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

    100. Historic American Buildings Survey COVERED WAY TO SECRETARY'S COTTAGE PHOTOCOPY OF PLATE FROM IRVIN L. SCOTT, 'MARALAGO', THE AMERICAN ARCHITECT (JUNE 20, 1928), P. 811 - Mar-a-Lago, 1100 South Ocean Boulevard, Palm Beach, Palm Beach County, FL

  1. BRIC-100VC Biological Research in Canisters (BRIC)-100VC

    NASA Technical Reports Server (NTRS)

    Richards, Stephanie E.; Levine, Howard G. (Compiler); Romero, Vergel

    2016-01-01

    The Biological Research in Canisters (BRIC) is an anodized-aluminum cylinder used to provide passive stowage for investigations of the effects of space flight on small specimens. The BRIC 100 mm petri dish vacuum containment unit (BRIC-100VC) has supported Dugesia japonica (flatworm) within spring under normal atmospheric conditions for 29 days in space and Hemerocallis lilioasphodelus L. (daylily) somatic embryo development within a 5% CO2 gaseous environment for 4.5 months in space. BRIC-100VC is a completely sealed, anodized-aluminum cylinder (Fig. 1) providing containment and structural support of the experimental specimens. The top and bottom lids of the canister include rapid disconnect valves for filling the canister with selected gases. These specialized valves allow for specific atmospheric containment within the canister, providing a gaseous environment defined by the investigator. Additionally, the top lid has been designed with a toggle latch and O-ring assembly allowing for prompt sealing and removal of the lid. The outside dimensions of the BRIC-100VC canisters are 16.0 cm (height) x 11.4 cm (outside diameter). The lower portion of the canister has been equipped with sufficient storage space for passive temperature and relative humidity data loggers. The BRIC- 100VC canister has been optimized to accommodate standard 100 mm laboratory petri dishes or 50 mL conical tubes. Depending on storage orientation, up to 6 or 9 canisters have been flown within an International Space Station (ISS) stowage locker.

  2. Apollo 20

    ERIC Educational Resources Information Center

    Houston Independent School District, 2013

    2013-01-01

    The Apollo 20 project was launched during the 2010-2011 school year to accelerate Houston Independent School District's (HISD's) efforts to improve student performance in every school and close the achievement gap districtwide. This partnership with EdLabs at Harvard University incorporates best practices from successful public and charter schools…

  3. M20

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    M20 is a diffuse nebula in Sagittarius known as the `TRIFID NEBULA' because of its three-lobed appearance. It is situated roughly 2 degrees northwest of M8. Messier described a `cluster of stars', William Herschel assigned different numbers to different parts of the object and John Herschel was the first to use the term `trifid'....

  4. 33 CFR 100.1101 - Southern California annual marine events.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... events. 100.1101 Section 100.1101 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND... annual marine events. (a) Special local regulations will be established for the events listed in Table 1... Local Notice to Mariners at least 20 days prior to each event. To be placed on the mailing list...

  5. High spatial resolution 100 micron observations of the M83 bar

    NASA Technical Reports Server (NTRS)

    Smith, B. J.; Lester, Dan F.; Harvey, P. M.

    1990-01-01

    A program of high spatial resolution far-infrared observations of galaxies using the Kuiper Airborne Observatory (KAO), was conducted to better understand the role of star formation, the general interstellar radiation field, and non-thermal activity in powering the prodigious far-infrared luminosities seen in spiral and interacting galaxies. Here, researchers present observations of the central region of the well-known barred spiral M83 (NGC 5236). The resultant channel 3 scans for M83 and IRC + 10216, after co-addition and smoothing, are shown. These data show that M83 is extended at 100 microns compared to a point source. A simple Gaussian deconvolution of the M83 data with the point source profile from IRC+10216 gives a full width half maximum (FWHM) of about 19 seconds for M83. By comparison with IRC+10216, researchers obtain a flux for the unresolved component in M83 of about 110 Jy. This is about 1/6 the total flux for M83 (Rice et al. 1988) and about 1/2 the PSC flux. The M83 and IRC+10216 profiles in the cross-scan direction (SE-NW) were also compared, and show that M83 is extended in this direction as well, with a width of about 18 seconds. A comparison of the different channel profiles for M83 and IRC+10216 shows that there is an asymmetry in the M83 data, in that the maximum in the profiles shifts from southeast to northwest as channel number increases. This corresponds to the extension in the bar seen in the CO data. Thus the far-infrared emission in the central region of M83 tends to trace the CO bar. The new 100 micron data is also compared with previous H alpha observations from the literature, to determine how well the far-infrared traces the stellar structure, the star formation as measured by H alpha, and the optical colors.

  6. 1-100 Rules Ok?

    ERIC Educational Resources Information Center

    Thompson, Ian

    2003-01-01

    In a recent edition of "Mathematics Teaching" Midge Pasternack argued the case for the use of the 0-99 square with young children rather than the ubiquitous 1-100 square. In this article, the author would like to take the opportunity to mount a defence in favour of the much maligned 1-100 square. His main criticism of the 0-99 square (apart from…

  7. Nanoporosity of Si (100) bars

    NASA Astrophysics Data System (ADS)

    Novikov, S. N.; Timoshenkov, S. P.; Minaev, V. S.; Goryunova, E. P.; Gerasimenko, N. N.; Smirnov, D. I.

    2016-09-01

    Si(100) samples cut from a typical bar (100 mm in diameter) prepared using industrial technology are studied. Measurements of the electron work function (EWF) show that the size effects in these samples (a reduction in thickness along with a sample's area and the EWF) detected earlier were due to nanostructure porosity that was buried by the technological treatment of a bar's surface. This hidden nanoporosity is assumed to be a manifestation of the secondary crystal structure.

  8. Functions of S100 Proteins

    PubMed Central

    Donato, R.; Cannon, B.R.; Sorci, G.; Riuzzi, F.; Hsu, K.; Weber, D.J.; Geczy, C.L.

    2013-01-01

    The S100 protein family consists of 24 members functionally distributed into three main subgroups: those that only exert intracellular regulatory effects, those with intracellular and extracellular functions and those which mainly exert extracellular regulatory effects. S100 proteins are only expressed in vertebrates and show cell-specific expression patterns. In some instances, a particular S100 protein can be induced in pathological circumstances in a cell type that does not express it in normal physiological conditions. Within cells, S100 proteins are involved in aspects of regulation of proliferation, differentiation, apoptosis, Ca2+ homeostasis, energy metabolism, inflammation and migration/invasion through interactions with a variety of target proteins including enzymes, cytoskeletal subunits, receptors, transcription factors and nucleic acids. Some S100 proteins are secreted or released and regulate cell functions in an autocrine and paracrine manner via activation of surface receptors (e.g. the receptor for advanced glycation end-products and toll-like receptor 4), G-protein-coupled receptors, scavenger receptors, or heparan sulfate proteoglycans and N-glycans. Extracellular S100A4 and S100B also interact with epidermal growth factor and basic fibroblast growth factor, respectively, thereby enhancing the activity of the corresponding receptors. Thus, extracellular S100 proteins exert regulatory activities on monocytes/macrophages/microglia, neutrophils, lymphocytes, mast cells, articular chondrocytes, endothelial and vascular smooth muscle cells, neurons, astrocytes, Schwann cells, epithelial cells, myoblasts and cardiomyocytes, thereby participating in innate and adaptive immune responses, cell migration and chemotaxis, tissue development and repair, and leukocyte and tumor cell invasion. PMID:22834835

  9. 100 Years Werner Heisenberg: Works and Impact

    NASA Astrophysics Data System (ADS)

    Papenfuß, Dietrich; Lüst, Dieter; Schleich, Wolfgang P.

    2003-09-01

    Over 40 renowned scientists from all around the world discuss the work and influence of Werner Heisenberg. The papers result from the symposium held by the Alexander von Humboldt-Stiftung on the occasion of the 100th anniversary of Heisenberg's birth, one of the most important physicists of the 20th century and cofounder of modern-day quantum mechanics. Taking atomic and laser physics as their starting point, the scientists illustrate the impact of Heisenberg's theories on astroparticle physics, high-energy physics and string theory right up to processing quantum information.

  10. Geochemical Characteristics of the Contaminant Waste Plume in the F-Area of the Savannah River Site: From Kilometer to Micrometer Scales

    NASA Astrophysics Data System (ADS)

    Dong, W.; Wan, J.; Denham, M.; Seaman, J. C.; Rakshit, S.; Tokunaga, T. K.; Spycher, N.; Hubbard, S. S.

    2010-12-01

    The Savannah River Site (SRS) was a major DOE facility for plutonium production during the Cold War. Low-level radioactivity acidic waste solutions were discharged to a series of unlined seepage basins in the F-Area of the SRS from 1955-1989. Although the site has gone through many years of active remediation, the groundwater remains acidic with pH values as low as 3.2, and the concentrations of U and other radionuclides are still up to ten times higher than their maximum contaminant levels (MCLs). In order to understand the current and predict the future contaminant behavior, a comprehensive investigation is being conducted, funded jointly by the DOE’s offices of Biological and Environmental Resources (BER) and Environmental Management (EM). Five boreholes were drilled outside and within the plume along the groundwater flow path. Samples were collected from varied depths of each borehole, sediment pore-waters were extracted by ultracentrifugation, and the solid phase and pore-water were characterized. We identified the sediment mineralogy as being composed predominantly fine quartz sand with 2 to 12% clay. Kaolinite and goethite are the major minerals of the clay-sized fraction, residing primarily as coatings of varied thicknesses on quartz sand grains, providing reactive surfaces for contaminant adsorption. The measured U “field” distribution coefficients (Kd) and U concentrations in the pore waters are strongly pH dependent. These results are consistent with laboratory equilibrium adsorption studies, where U adsorption onto SRS sediments increases sharply from pH 3 to 5, and reaches ≈100% at pH 6-7. The variability in U adsorption capacity in these sediments is mainly caused by differences in goethite/clay content and effective reactive specific surface area. Measured “field” Kd values are smaller than those obtained from laboratory equilibrium adsorption studies with the same contaminated sediments. The equilibrium pH-dependent U adsorption

  11. THE SPIRAL GALAXY M100

    NASA Technical Reports Server (NTRS)

    2002-01-01

    An image of the grand design of spiral galaxy M100 obtained with NASA's Hubble Space Telescope resolves individual stars within the majestic spiral arms. (These stars typically appeared blurred together when viewed with ground-based telescopes.) Hubble has the ability to resolve individual stars in other galaxies and measure accurately the light from very faint stars. This makes space telescope invaluable for identifying a rare class of pulsating stars, called Cepheid Variable stars embedded within M100's spiral arms. Cepheids are reliable cosmic distance mileposts. The interval it takes for the Cepheid to complete one pulsation is a direct indication of the stars's intrinsic brightness. This value can be used to make a precise measurement of the galaxy's distance, which turns out to be 56 million light-years. M100 (100th object in the Messier catalog of non-stellar objects) is a majestic face-on spiral galaxy. It is a rotating system of gas and stars, similar to our own galaxy, the Milky Way. Hubble routinely can view M100 with a level of clarity and sensitivity previously possible only for the very few nearby galaxies that compose our 'Local Group.'' M100 is a member of the huge Virgo cluster of an estimated 2,500 galaxies. The galaxy can be seen by amateur astronomers as a faint, pinwheel-shaped object in the spring constellation Coma Berenices. Technical Information: The Hubble Space Telescope image was taken on December 31, 1993 with the Wide Field Planetary Camera 2 (WFPC 2). This color picture is a composite of several images taken in different colors of light. Blue corresponds to regions containing hot newborn stars. The Wide Field and Planetary Camera 2 was developed by the Jet Propulsion Laboratory (JPL) and managed by the Goddard Space Flight Center for NASA's Office of Space Science. Credit: J. Trauger, JPL and NASA

  12. The science case and data processing strategy for the Thinned Aperture Light Collector (TALC): a project for a 20m far-infrared space telescope

    NASA Astrophysics Data System (ADS)

    Sauvage, Marc; Chanial, Pierre; Durand, Gilles A.; Rodriguez, Louis R.; Starck, Jean-Luc; Ronayette, Samuel; Aussel, Hervé; Minier, Vincent; Motte, Frédérique; Pantin, Eric J.; Sureau, Florent; Terrisse, Robin

    2014-08-01

    The future of far-infrared observations rests on our capacity to reach sub-arcsecond angular resolution around 100 μm, in order to achieve a significant advance with respect to our current capabilities. Furthermore, by reaching this angular resolution we can bridge the gap between capacities offered by the JWST in the near infrared and those allowed by ALMA in the submillimeter, and thus benefit from similar resolving capacities over the whole wavelength range where interstellar dust radiates and where key atomic and molecular transitions are found. In an accompanying paper,1 we present a concept of a deployable annular telescope, named TALC for Thinned Aperture Light Collector, reaching 20m in diameter. Being annular, this telescope features a main beam width equivalent to that of a 27m telescope, i.e. an angular resolution of 0.92" at 100 μm. In this paper we focus on the science case of such a telescope as well on the aspects of unconventional data processing that come with this unconventional optical configuration. The principal science cases of TALC revolve around its imaging capacities, that allow resolving the Kuiper belt in extra-solar planetary systems, or the filamentary scale in star forming clouds all the way to the Galactic Center, or the Narrow Line Region in Active Galactic Nuclei of the Local Group, or breaking the confusion limit to resolve the Cosmic Infrared Background. Equipping this telescope with detectors capable of imaging polarimetry offers as well the extremely interesting perspective to study the influence of the magnetic field in structuring the interstellar medium. We will then present simulations of the optical performance of such a telescope. The main feature of an annular telescope is the small amount of energy contained in the main beam, around 30% for the studied configuration, and the presence of bright diffraction rings. Using simulated point spread functions for realistic broad-band filters, we study the observing performance

  13. Large Expanses of Kilometer-Scale Waves Predominantly Observed Below the F-peak Encountered by the Electric Field and Plasma Density Probes on the C/NOFS Satellite

    NASA Astrophysics Data System (ADS)

    Pfaff, R. F.; Liebrecht, C.; Freudenreich, H.; Klenzing, J.

    2013-12-01

    The Vector Electric Field Investigation (VEFI) on the C/NOFS equatorial satellite provides a unique data set which includes detailed measurements of irregularities associated with the equatorial ionosphere. We present vector AC electric field and plasma density observations gathered on C/NOFS that reveal vast expanses of kilometer scales along the C/NOFS orbit. In many cases, these waves are observed for 1000's of kilometers along the satellite track and appear most prevalent in cases where the ionosphere F-peak has been elevated above the C/NOFS satellite perigee of 400 km. The vector electric field instrument on C/NOFS clearly shows that the electric field component of these waves is strongest in the zonal direction. The electric field components are strongly correlated with simultaneous observations of plasma density oscillations and appear both with, and without, evidence of larger-scale spread-F depletions. These km-scale, quasi-coherent waves strongly resemble the bottomside, sinusoidal irregularities reported in the Atmosphere Explorer satellite data set by Valladares et al. [JGR, 88, 8025, 1983] and are believed to cause scintillations of VHF radiowaves. Indeed, the observations show that such waves are a common feature in the low latitude ionosphere, particularly below the F-peak. We present detailed analyses of the wave measurements and interpret these new observations in terms of plasma instabilities associated with the nighttime equatorial ionosphere.

  14. SLA at 100: Conference Preview

    ERIC Educational Resources Information Center

    Blumenstein, Lynn

    2009-01-01

    When School Library Association (SLA) convenes its annual conference in Washington, DC, June 14-17, 2009, the association will be celebrating its 100th birthday. This occasion allows for grand gestures--the SLA Salutes! Awards and Leadership Reception will be held in the Library of Congress's Great Hall. The conference also draws upon Washington…

  15. At 100, NAACP Still Kicking

    ERIC Educational Resources Information Center

    Stuart, Reginald

    2009-01-01

    When leaders of the NAACP gather this month to formally begin a year-long recognition of 100 years of civil rights work, they'll be talking as much about the organization's future as they will be honoring its past. On dozens of college campuses across the nation, where plenty of groups have taken on justice issues that for decades only the NAACP…

  16. The Journey toward 100% Proficiency

    ERIC Educational Resources Information Center

    Mindish, Jan; Sullivan, Marianne; Stiklaitis, Angela; Baireuther, Diane

    2008-01-01

    The journey toward 100% proficiency is most successful when a whole school works as a team. School leaders must focus their school's energy and effort on schoolwide initiatives that will make the changes needed to increase student learning and improve students' scores on state tests. The structure of the school and the collaboration of the faculty…

  17. The AS&U 100

    ERIC Educational Resources Information Center

    Kennedy, Mike

    2007-01-01

    In 1986, the Indianapolis and Gwinnett County (Georgia) school districts sat side by side on the list of the 100 largest school districts, each with slightly less than 51,000 students. But the districts were headed in opposite directions. By 2005, enrollment in Indianapolis declined by about 25 percent to 38,142, falling from the 63rd-largest to…

  18. The 2002 Training Top 100.

    ERIC Educational Resources Information Center

    Training, 2002

    2002-01-01

    Identifies the top 100 companies in terms of the amount spent on training and development, the number of hours of training per employee, percentage of payroll spent on training, and tuition allotment per employee. Describes best practices in succession planning and leadership development, mentoring, and job shadowing and provides a detailed…

  19. The 2003 Training Top 100.

    ERIC Educational Resources Information Center

    Galvin, Tammy

    2003-01-01

    Identifies the top 100 U.S. companies in terms of the amount spent on training and development, the number of hours of training per employee, percentage of payroll spent on training, and tuition allotment per employee. Describes best practices in succession planning and leadership development, mentoring, and job shadowing and provides a detailed…

  20. The Top 100: Associate Rankings

    ERIC Educational Resources Information Center

    Blackmon, Olivia

    2009-01-01

    This year, Diverse has added a new addition to its annual Top 100 degree producers series--recognizing, with this edition, the institutions that award the most associate degrees to students of color. More than half of minority undergraduate students start their degree quest at a community college with 55 percent of all Hispanic and Native American…

  1. CX-100 and TX-100 blade field tests.

    SciTech Connect

    Holman, Adam (USDA-Agriculture Research Service, Bushland, TX); Jones, Perry L.; Zayas, Jose R.

    2005-12-01

    In support of the DOE Low Wind Speed Turbine (LWST) program two of the three Micon 65/13M wind turbines at the USDA Agricultural Research Service (ARS) center in Bushland, Texas will be used to test two sets of experimental blades, the CX-100 and TX-100. The blade aerodynamic and structural characterization, meteorological inflow and wind turbine structural response will be monitored with an array of 75 instruments: 33 to characterize the blades, 15 to characterize the inflow, and 27 to characterize the time-varying state of the turbine. For both tests, data will be sampled at a rate of 30 Hz using the ATLAS II (Accurate GPS Time-Linked Data Acquisition System) data acquisition system. The system features a time-synchronized continuous data stream and telemetered data from the turbine rotor. This paper documents the instruments and infrastructure that have been developed to monitor these blades, turbines and inflow.

  2. Design of applicative 100 W Stirling engine

    SciTech Connect

    Kagawa, Noboru; Hirata, Koichi; Takeuchi, Makoto

    1995-12-31

    A small 100 W displacer type Stirling engine is being developed under a project of a JSME committee, RC127. The project consists of sixteen Japanese academic researchers of universities and governmental laboratories and eleven enterprise members related to the Stirling field. The engine has very unique features. Its expansion cylinder is heated by combustion gas or solar energy directly, and a simple cooling system rejects heat from the working fluid. A regenerator is built in the displacer piston with heating and cooling tubes in which the working fluid flows from/to outer tubes. The outer tubes for heating were located at the top of the expansion cylinder and the tubes for cooling are in the middle of the cylinder. The target performance is a 100 W output with 20% thermal efficiency at the operating conditions of 923 K expansion space temperature, 343 K compression space temperature, and 1,000 rpm. The 100 W displacer engine was designed based on a design manual established by a related JSME committee, RC110. It contains several guides to design for cycle, heat exchanger system, and mechanism of most Stirling cycle machines. The engine was designed by using the fundamental method, the second and third-order analyses accomplished with the newly arranged knowledge about each component. This paper presents the engine specifications and the theoretical analysis results. The design method is also introduced briefly.

  3. Changes in single skinfold thickness in 100 km ultramarathoners

    PubMed Central

    Knechtle, Beat; Baumgartner, Sabrina; Knechtle, Patrizia; Rüst, Christoph Alexander; Rosemann, Thomas; Bescós, Raúl

    2012-01-01

    Background Changes in single skinfold thickness and body fat have been investigated in ultraswimmers and ultracyclists, but not in ultrarunners. The present study investigated the changes in single skinfold thickness during a 100 km ultramarathon. Methods Firstly, we investigated associations between prerace preparation and prerace body composition and, secondly, changes in single skinfold thickness during a 100 km ultramarathon in 219 male ultramarathoners. Changes in fat mass and skeletal muscle were estimated using anthropometric methods. Results Kilometers run weekly prerace and running speed during training were negatively associated with all skinfold thicknesses (P < 0.05) except for the front thigh skinfold. During the race, skinfold thickness at the pectoral (−0.1%), suprailiac (−1.8%), and calf (−0.8%) sites decreased (P < 0.05). The subjects lost 1.9 ± 1.4 kg of body mass (P < 0.001), 0.7 ± 1.0 kg of estimated skeletal muscle mass (P < 0.001), and 0.2 ± 1.3 kg of estimated fat mass (P < 0.05). The decrease in body mass was positively related to the decrease in both estimated skeletal muscle mass (r = 0.21, P = 0.0017) and estimated fat mass (r = 0.41, P < 0.0001). Conclusion Firstly, prerace fat mass and prerace skinfold thickness were associated with both volume and speed in running training. Secondly, during the ultramarathon, skinfold thickness decreased at the pectoral, suprailiac, and calf sites, but not at the thigh site. Percent decreases in skinfold thickness for ultrarunners was lower than the percent decreases in skinfold thickness reported for ultraswimmers and ultracyclists. PMID:24198597

  4. Wilson's disease, 100 years later….

    PubMed

    Trocello, J-M; Broussolle, E; Girardot-Tinant, N; Pelosse, M; Lachaux, A; Lloyd, C; Woimant, F

    2013-12-01

    Texts published, in 1912, 100 years ago, by Sir K. Wilson on his eponymous disease in Brain, The Lancet and La Revue Neurologique highlight the relevance of his descriptions in the light of the current knowledge. Wilson's invocation of an "unknown toxin" appears today as a prophetic intuition as the presence of excess copper in the liver was mentioned for the first time a year later whereas the role of copper in this disease was not described until 1929. Progress has been made to better understand the physiology of Wilson's disease (WD). The ATP7B gene implicated in WD is located on chromosome 13 and more than 500 mutations and 100 polymorphisms have been to date identified. The phenotypic expression is highly variable, even within a family. This can partly be explained by environmental factors as nutrition. Modulator genes are also involved in the phenotypic expression of the disease. Most of symptoms observed in WD have already been described in detail by Wilson in 1912, but subsequent progress was made over the following 100 years, helping the physician diagnose WD. Hepatic and neurological symptoms are the most frequent expressions of the disease. Other extrahepatic features include renal manifestations, osteoarticular disorders, myocardial abnormalities, endocrine disturbances, realizing a multisystemic disease. The diagnosis of the disease is based on a combination of clinical symptoms, biological, radiological and genetic data and new tools (Brain MRI, relative exchangeable copper…) allow reducing delay to diagnosis. Therapeutic findings have also changed the disease prognosis. Treatment is based on the use of copper chelators to promote copper excretion from the body (D-penicillamine and Triethylenetetramine) and zinc salts to reduce copper absorption. Tetratiomolybdate appears to be a promising treatment. While significant progress has been made during this century, many physiological aspects of this disease remain unknown and require further research to

  5. Science up to 100 tesla

    SciTech Connect

    Campbell, L.J.

    1995-05-01

    100 Tesla is the highest attainable field that can be held for milli-sec in a non-destructive magnet. The strongest steels turn soft under stresses of 4GPa, which is the magnetic pressure of 100 T. Until there is a breakthrough in materials, magnets having all the low temperature and high pressure trimmings will be limited to about 100 T. Within the field range 1-100 T far more resources are now devoted to producing the highest possible continuous fields (40+5 T) than to producing longer pulsed fields above 50 T. This illustrates that the utility of the field can be more important than the strength of the field to researchers in condensed matter. Discoveries are typically made in new territory, but this can be new combinations of pressure, temperature, and magnetic field, or new probes and new materials. If any activity has kept up with the proliferation of new experiments and new facilities in high magnetic field research it is the listing of experiments that could and should be done in high fields. Part of the reason for the vitality of high field research is that high fields provide a generic environment. Compared to particle accelerators and plasma machines a high field laboratory is a setting for generic science, like synchrotron light sources or neutron scattering centers. Although the latter two installations probes states, while a magnetic field creates a state. Because it is unrealistic to try to list all the science opportunities at high fields, the author list sources for lists in the public domain and gives a few examples.

  6. 100 Years of Reality Learning

    ERIC Educational Resources Information Center

    Zimpher, Nancy L.; Wright Ron, D.

    2006-01-01

    One may have heard of reality TV, but what about reality learning? The latter is probably a term one hasn't seen much, although it is in many ways a clearer and more concise name for a concept that in 2006 marks its 100th anniversary: cooperative education, or "co-op." Co-op, a break-through idea pioneered at the University of Cincinnati by Herman…

  7. Wilson's disease, 100 years later….

    PubMed

    Trocello, J-M; Broussolle, E; Girardot-Tinant, N; Pelosse, M; Lachaux, A; Lloyd, C; Woimant, F

    2013-12-01

    Texts published, in 1912, 100 years ago, by Sir K. Wilson on his eponymous disease in Brain, The Lancet and La Revue Neurologique highlight the relevance of his descriptions in the light of the current knowledge. Wilson's invocation of an "unknown toxin" appears today as a prophetic intuition as the presence of excess copper in the liver was mentioned for the first time a year later whereas the role of copper in this disease was not described until 1929. Progress has been made to better understand the physiology of Wilson's disease (WD). The ATP7B gene implicated in WD is located on chromosome 13 and more than 500 mutations and 100 polymorphisms have been to date identified. The phenotypic expression is highly variable, even within a family. This can partly be explained by environmental factors as nutrition. Modulator genes are also involved in the phenotypic expression of the disease. Most of symptoms observed in WD have already been described in detail by Wilson in 1912, but subsequent progress was made over the following 100 years, helping the physician diagnose WD. Hepatic and neurological symptoms are the most frequent expressions of the disease. Other extrahepatic features include renal manifestations, osteoarticular disorders, myocardial abnormalities, endocrine disturbances, realizing a multisystemic disease. The diagnosis of the disease is based on a combination of clinical symptoms, biological, radiological and genetic data and new tools (Brain MRI, relative exchangeable copper…) allow reducing delay to diagnosis. Therapeutic findings have also changed the disease prognosis. Treatment is based on the use of copper chelators to promote copper excretion from the body (D-penicillamine and Triethylenetetramine) and zinc salts to reduce copper absorption. Tetratiomolybdate appears to be a promising treatment. While significant progress has been made during this century, many physiological aspects of this disease remain unknown and require further research to

  8. CEPHEID VARIABLE STAR IN GALAXY M100

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This NASA Hubble Space Telescope image of a region of the galaxy M100 shows a class of pulsating star called a Cepheid Variable. Though rare, these stars are reliable distance indicators to galaxies. Based on the Hubble observation, the distance to M100 has been measured accurately as 56 million light-years (+/- 6 million light-years), making it the farthest object where intergalactic distances have been determined precisely. Hubble's high resolution pinpoints a Cepheid, which is located in a starbirth region in one of the galaxy's spiral arms (bottom frame). The top three frames were taken on (from left to right) May 9, May 4, May 31, and they reveal that the star (in center of each box) changes brightness. Cepheids go through these changes rhythmically over a few weeks. The interval it takes for the Cepheid to complete one pulsation is a direct indication of the stars's intrinsic brightness. This value can be used to make a precise measurement of the galaxy's distance. Only Hubble Space Telescope has the required sensitivity and resolution to detect these 'cosmic milepost' type stars out to great distances from Earth, according to astronomers. Typically, Cepheids in a crowded region of a distant galaxy are too faint and the resolution too poor, as seen from ground-based telescopes, to be detected clearly. Hubble was used to make twelve one-hour exposures, timed carefully in a two-month observing window, to discover 20 Cepheid variable stars in the M100 galaxy. Though M100 is the most distant galaxy in which Cepheid variables have been discovered, HST must find Cepheids in even more distant galaxies before accurate distances can be used to calculate a definitive size and age for the universe. Technical Information: The Hubble Space Telescope image was taken with the Wide Field Planetary Camera 2 (WFPC 2). This black and white picture was taken at visible light wavelengths. Target Information: M100 (100th object in the Messier catalog of non-stellar objects) is a

  9. 20 CFR 625.20 - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false 625.20 Section 625.20 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR DISASTER UNEMPLOYMENT ASSISTANCE § 625.20...

  10. 20 CFR 625.20 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false 625.20 Section 625.20 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR DISASTER UNEMPLOYMENT ASSISTANCE § 625.20...

  11. [100 years' of clinical electrocardiography].

    PubMed

    Bergovec, Mijo

    2003-01-01

    In 1903 Willem Einthoven published in Pflügers Arch his classic article on the investigation of human electrocardiogram by his string galvanometer. Many historians of medicine, Einthoven also marked that publication as the beginning of clinical electrocardiography. Many investigators like Galvani, Manteucci, Kölliker, Müller, Lipmann, Waller, Ader, Einthoven, Lewis, Wilson and others participated in creation and development of electrocardiogram. From that time electrocardiogram quickly became, and has remained the most essential diagnostic laboratory tool in investigation of heart diseases. The aim of this article is to remind us of the beginning of this part of cardiology 100 years ago. PMID:15209030

  12. 34 CFR 85.100 - What does this part do?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...” (3 CFR 1986 Comp., p. 189), Executive Order 12689, “Debarment and Suspension” (3 CFR 1989 Comp., p... (3 CFR, 1986 Comp., p. 189); E.O 12689 (3 CFR, 1989 Comp., p. 235); 20 U.S.C. 1082, 1094, 1221e-3 and... 34 Education 1 2010-07-01 2010-07-01 false What does this part do? 85.100 Section 85.100...

  13. Absolute optical metrology : nanometers to kilometers

    NASA Technical Reports Server (NTRS)

    Dubovitsky, Serge; Lay, O. P.; Peters, R. D.; Liebe, C. C.

    2005-01-01

    We provide and overview of the developments in the field of high-accuracy absolute optical metrology with emphasis on space-based applications. Specific work on the Modulation Sideband Technology for Absolute Ranging (MSTAR) sensor is described along with novel applications of the sensor.

  14. SKADS: Sub-Kilometer Asteroid Diameter Survey

    NASA Astrophysics Data System (ADS)

    Davis, D. R.; Gladman, B.; Jedicke, R.; Williams, G.

    2004-11-01

    We surveyed 8 sq deg over the course of six nights (March 21-23 and March 29-31 UT, 2001) using the mosaic camera on the KPNO 4m telescope. This survey was designed to sample the mainbelt asteroid size and orbit distribution down to mR ˜ 23 and to obtain V and R band photometry on these objects. Improved understanding of the asteroid size distribution is needed to refine our knowledge of the disruptive scaling law and the collisional evolution of asteroids. On each night, 24 fields were observed 3 times with the fields being shifted by the mean motion of mainbelt asteroids between dates. Data was taken on all six nights with 4 nights being photometric for all or most of the night. A total of 1087 asteroids were detected on 2 or more of the 6 nights while 907 asteroids were detected on at least 4 nights to allow a ``good" orbit to be determined. The 50% detection efficiency was between mR ˜ 22.9 and 23.1 for the photometric nights. Debiasing the detected asteroids will yield the asteroid diameter distribution down to sub-km sizes.

  15. [100 years physical therapy and rehabilitation].

    PubMed

    Heipertz, W

    2001-10-01

    Physical medicine and rehabilitation received powerful impulses from orthopaedic surgery, which organizes its pragmatic and scientific interests since 100 years in its own association. A point of breakthrough was reached at the beginning of the 20th century, when progress in surgical and conservative orthopaedics enabled a comprehensive rehabilitation of physically disabled. On the other hand, the professionalisation of care for the handicapped (Krüppelfürsorge) has decisively supported the advancement of orthopaedics. Next to the storming development of orthopaedic surgery step by step the scientific foundations and clear indications for physiotherapy were achieved. The strategy of treatment was adapted to the increasingly active approach to orthopaedic ailments and traumata. This relates as well to wide ranges of rehabilitation and developed the training of specialists. Orthopaedic surgeons were significantly involved in this development as well as the framing of legal regulations safeguarding the entitlement of the disabled.

  16. 100-B area technical baseline report

    SciTech Connect

    Carpenter, R.W.

    1994-09-01

    This document supports the environmental remediation effort of the 100-B Area by providing remediation planners with key data that characterize the 100-B and 100-C Reactor sites. It provides operational histories of the 100-B and 100-C Reactors and each of their associated liquid and solid waste sites.

  17. Early SP-100 flight mission designs

    NASA Astrophysics Data System (ADS)

    Josloff, Allan T.; Shepard, Neal F.; Kirpich, Aaron S.; Murata, Ronald; Smith, Michael A.; Stephen, James D.

    1993-01-01

    Early flight mission objectives can be met with a Space Reactor Power System (SRPS) using thermoelectric conversion in conjunction with fast spectrum, lithium-cooled reactors. This paper describes two system design options using thermoelectric technology to accommodate an early launch. In the first of these options, radiatively coupled Radioiosotope Thermoelectric Generator (RTG) unicouples are adapted for use with a SP-100-type reactor heat source. Unicouples have been widely used as the conversion technology in RTGs and have demonstrated the long-life characteristics necessary for a highly relible SRPS. The thermoelectric leg height is optimized in conjunction with the heat rejection temperature to provide a mass optimum 6-kWe system configured for launch on a Delta II launch vehicle. The flight-demonstrated status of this conversion technology provides a high confidence that such a system can be designed, assembled, tested, and launched by 1997. The use of a SP-100-type reactor assures compliance with safety requirements and expedites the flight safety approval process while, at the same time, providing flight performance verification for a heat source technology with the growth potential to meet future national needs for higher power levels. A 15-kW2, Atlas IIAS-launched system using the compact, conductively coupled multicouple converters being developed under the SP-100 program to support an early flight system launch also described. Both design concepts have been scaled to 20-kWe in order to support recent studies by DOE/NASA for higher power early launch missions.

  18. 100 Gb/s optical discrete multi-tone transceivers for intra- and inter-datacenter networks

    NASA Astrophysics Data System (ADS)

    Okabe, Ryo; Tanaka, Toshiki; Nishihara, Masato; Kai, Yutaka; Takahara, Tomoo; Liu, Bo; Li, Lei; Tao, Zhenning; Rasmussen, Jens C.

    2016-03-01

    Discrete multi-tone (DMT) technology is an attractive modulation technology for short-reach application due to its high spectral efficiency and simple configuration. In this paper, we first explain the features of DMT technology then discuss the impact of fiber dispersion and chirp on the frequency responses of the DMT signal and the importance in the relationship between chirp and the optical transmission band. Next, we explain our experiments of 100-Gb/s DMT transmission of 10 km in the O-band using directly modulated lasers for low-cost application. In an inter-datacenter network of more than several tens of kilometers, fiber dispersion mainly limits system performance. We also discuss our experiment of 100-Gb/s DMT transmission up to 100 km in the C-band without a dispersion compensator by using vestigial sideband spectrum shaping and nonlinear compensation.

  19. 100-Picometer Interferometry for EUVL

    SciTech Connect

    Sommargren, G E; Phillion, D W; Johnson, M A; Nguyen, N O; Barty, A; Snell, F J; Dillon, D R; Bradsher, L S

    2002-03-18

    Future extreme ultraviolet lithography (EWL) steppers will, in all likelihood, have six-mirror projection cameras. To operate at the diffraction limit over an acceptable depth of focus each aspheric mirror will have to be fabricated with an absolute figure accuracy approaching 100 pm rms. We are currently developing visible light interferometry to meet this need based on modifications of our present phase shifting diffraction interferometry (PSDI) methodology where we achieved an absolute accuracy of 250pm. The basic PSDI approach has been further simplified, using lensless imaging based on computational diffractive back-propagation, to eliminate auxiliary optics that typically limit measurement accuracy. Small remaining error sources, related to geometric positioning, CCD camera pixel spacing and laser wavelength, have been modeled and measured. Using these results we have estimated the total system error for measuring off-axis aspheric EUVL mirrors with this new approach to interferometry.

  20. AGT100 turbomachinery. [for automobiles

    NASA Technical Reports Server (NTRS)

    Tipton, D. L.; Mckain, T. F.

    1982-01-01

    High-performance turbomachinery components have been designed and tested for the AGT100 automotive engine. The required wide range of operation coupled with the small component size, compact packaging, and low cost of production provide significant aerodynamic challenges. Aerodynamic design and development testing of the centrifugal compressor and two radial turbines are described. The compressor achieved design flow, pressure ratio, and surge margin on the initial build. Variable inlet guide vanes have proven effective in modulating flow capacity and in improving part-speed efficiency. With optimum use of the variable inlet guide vanes, the initial efficiency goals have been demonstrated in the critical idle-to-70% gasifier speed range. The gasifier turbine exceeded initial performance goals and demonstrated good performance over a wide range. The radial power turbine achieved 'developed' efficiency goals on the first build.