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Sample records for lightcurves preliminary study

  1. Variability and Lightcurves Studies in the Outer Solar System Origins Survey

    NASA Astrophysics Data System (ADS)

    Benecchi, Susan D.; Chen, Ying-Tung; Schwamb, Meg; Wang, Shiang-Yu; Lehner, Matthew; Alexandersen, Mike

    2015-11-01

    Lightcurves provide a powerful mechanism for learning about the history of the collisional and/or gravitational processes acting on small bodies since the formation, and subsequent migration, of our solar nebula. At the extremes, they can provide constraints on the material properties (and interior structure) of individual objects and perhaps in quantity can provide information about their source populations. Our project consists of two datasets: (1) the Outer Solar System Origins Survey (OSSOS) discovery and recovery magnitudes, and (2) observations from a 6-hour pilot study on a subset of (17) OSSOS objects using the Subaru and Hyper Suprime-Cam (HSC) instrument. The OSSOS objects span a full range of sizes, from as large as several hundreds of km to as small as a few tens of km in diameter. Because of the telescope diameter and the wide field of view of HSC, we are able to obtain measurements on multiple objects covering a range of magnitudes with a single telescope pointing within the first two years following object discovery. The OSSOS survey is well calibrated photometrically and as such we use the very sparce sampling in the discovery and recovery magnitudes to identify which objects might have the largest amplitude lightcruves, indicating that they are likely elongated or in potentially interesting spin states. We then select the HSC fields containing these objects and the highest density of surrounding objects to obtain more densely sampled lightcurves. In this way we optimize the telescope time and the potential scientific return. We will present our analysis of the OSSOS dataset and some preliminary results from HSC.

  2. Potentially Hazardous Asteroid (85989) 1999 JD6: Radar, Infrared, and Lightcurve Observations and a Preliminary Shape Model

    NASA Astrophysics Data System (ADS)

    Marshall, Sean E.; Howell, Ellen S.; Brozović, Marina; Taylor, Patrick A.; Campbell, Donald B.; Benner, Lance A. M.; Naidu, Shantanu P.; Giorgini, Jon D.; Jao, Joseph S.; Lee, Clement G.; Richardson, James E.; Rodriguez-Ford, Linda A.; Rivera-Valentin, Edgard G.; Ghigo, Frank; Kobelski, Adam; Busch, Michael W.; Pravec, Petr; Warner, Brian D.; Reddy, Vishnu; Hicks, Michael D.; Crowell, Jenna L.; Fernandez, Yanga R.; Vervack, Ronald J.; Nolan, Michael C.; Magri, Christopher; Sharkey, Benjamin; Bozek, Brandon

    2015-11-01

    We report observations of potentially hazardous asteroid (85989) 1999 JD6, which passed 0.048 AU from Earth (19 lunar distances) during its close approach on July 25, 2015. During eleven days between July 15 and August 4, 2015, we observed 1999 JD6 with the Goldstone Solar System Radar and with Arecibo Observatory's planetary radar, including bistatic reception of some Goldstone echoes at Green Bank. We obtained delay-Doppler radar images at a wide range of latitudes, with range resolutions varying from 7.5 to 150 meters per pixel, depending on the observing conditions. We acquired near-infrared spectra from the NASA InfraRed Telescope Facility (IRTF) on two nights in July 2015, at wavelengths from 0.75 to 5.0 microns, showing JD6's thermal emission. We also obtained optical lightcurves from Ondrejov Observatory (in 1999), Table Mountain Observatory (in 2000), and Palmer Divide Station (in 2015). Previous observers had suggested that 1999 JD6 was most likely an elongated object, based on its large lightcurve amplitude of 1.2 magnitudes (Szabo et al. 2001; Polishook and Brosch 2008; Warner 2014). The radar images reveal an elongated peanut-shaped object, with two lobes separated by a sharp concavity. JD6's maximum diameter is about two kilometers, and its larger lobe is approximately 50% longer than its smaller lobe. The larger lobe has a concavity on its end. We will present more details on the shape and rotation state of 1999 JD6, as well as its surface properties from optical and infrared data and thermal modeling.

  3. Study of GRB Light-curve Decay Indices in the Afterglow Phase

    NASA Astrophysics Data System (ADS)

    Del Vecchio, Roberta; Giovanna Dainotti, Maria; Ostrowski, Michał

    2016-09-01

    In this work, we study the distribution of temporal power-law decay indices, α, in the gamma-ray burst (GRB) afterglow phase, fitted for 176 GRBs (139 long GRBs, 12 short GRBs with extended emission, and 25 X-ray flashes) with known redshifts. These indices are compared with the temporal decay index, α W , derived with the light-curve fitting using the Willingale et al. model. This model fitting yields similar distributions of α W to the fitted α, but for individual bursts a difference can be significant. Analysis of (α, L a ) distribution, where L a is the characteristic luminosity at the end of the plateau, reveals only a weak correlation of these quantities. However, we discovered a significant regular trend when studying GRB α values along the Dainotti et al. correlation between L a and the end time of the plateau emission in the rest frame, {T}a* , hereafter LT correlation. We note a systematic variation of the α parameter distribution with luminosity for any selected {T}a* . We analyze this systematics with respect to the fitted LT correlation line, expecting that the presented trend may allow us to constrain the GRB physical models. We also attempted to use the derived correlation of α ({T}a) versus {L}a({T}a) to diminish the luminosity scatter related to the variations of α along the LT distribution, a step forward in the effort of standardizing GRBs. A proposed toy model accounting for this systematics applied to the analyzed GRB distribution results in a slight increase of the LT correlation coefficient.

  4. Physical studies of small asteroids. I - Lightcurves and taxonomy of 10 asteroids

    NASA Technical Reports Server (NTRS)

    Wisniewski, W. Z.

    1991-01-01

    Photometric observations of 10 small asteroids (10 km or less in diameter), obtained using the 1.5-m Mt. Lemmon and 2.3-m Kitt Peak telescopes of the University of Arizona during 1986-1987, are reported. The instrumentation and data-reduction techniques employed are described, and the results are presented in tables and light-curve plots and briefly characterized.

  5. The asteroid lightcurve database

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Harris, Alan W.; Pravec, Petr

    2009-07-01

    The compilation of a central database for asteroid lightcurve data, i.e., rotation rate and amplitude along with ancillary information such as diameter and albedo (known or estimated), taxonomic class, etc., has been important to statistical studies for several decades. Having such a compilation saves the researcher hours of effort combing through any number of journals, some obvious and some not, to check on prior research. Harris has been compiling such data in the Asteroid Lightcurve Database (LCDB) for more than 25 years with Warner and Pravec assisting the past several years. The main data included in the LCDB are lightcurve rotation periods and amplitudes, color indices, H-G parameters, diameters (actual or derived), basic binary asteroid parameters, and spin axis and shape models. As time permits we are reviewing existing entries to enter data not previously recorded ( e.g., phase angle data). As of 2008 December, data for 3741 asteroids based on more than 10650 separate detail records derived from entries in various journals were included in the LCDB. Of those 3741 asteroids, approximately 3100 have data of sufficient quality for statistical analysis, including 7 that have "dual citizenship" - meaning that they have (or had) asteroid designations as well comet designations. Here we present a discussion of the nature of LCDB data, i.e., which values are actually measured and which are derived. For derived data, we give our justification for specific values. We also present some analysis based on the LCDB data, including new default albedo ( p) and phase slope parameter ( G) values for the primary taxonomic classes and a review of the frequency-diameter distribution of all asteroids as well as some selected subsets. The most recent version of data used in this analysis is available for download from the Collaborative Asteroid Lightcurve Link (CALL) site at http://www.MinorPlanetObserver.com/astlc/default.htm. Other data sets, some only subsets of the full

  6. Lightcurve Results for Eleven Asteroids

    NASA Astrophysics Data System (ADS)

    Gartrelle, Gordon M.

    2012-04-01

    Differential photometry techniques were used to develop lightcurves, rotation periods and amplitudes for eleven main-belt asteroids: 833 Monica, 962 Aslog, 1020 Arcadia, 1082 Pirola, 1097 Vicia, 1122 Lugduna, 1145 Robelmonte, 1253 Frisia, 1256 Normannia, 1525 Savolinna, and 2324 Janice. Ground-based observations from Badlands Observatory (BLO) in Quinn, SD, as well as the University of North Dakota Observatory (UND) in Grand Forks, ND, provided the data for the project. A search of the asteroid lightcurve database (LCDB) did not reveal any previously reported results for seven of the eleven targets in this study.

  7. Asteroid lightcurve observations from 1981

    NASA Technical Reports Server (NTRS)

    Harris, A. W.; Young, J. W.; Dockweiler, Thor; Gibson, J.; Poutanen, M.; Bowell, E.

    1992-01-01

    Photoelectric lightcurve observations in the V band, together with estimates of the mean and maximum reduced magnitudes, are presented for 59 different asteroids; 15 new or significantly revised periods are reported. While fits are generally good for objects with moderate phase-relation slope, poor quality fits remain among the highest and lowest albedo objects studied in virtue of their respectively shallow and steep sloping-phase curves.

  8. Asteroid Lightcurves from Estcorn Observatory

    NASA Astrophysics Data System (ADS)

    Klinglesmith, Daniel A., III; Hendrickx, Sebastian; Madden, Karl; Montgomery, Samuel

    2016-07-01

    We obtained lightcurves and amplitudes for 17 asteroids, 8 of which had unknown or poorly determined periods. The other 9 have known lightcurves at several oppositions and so are candidates for spin/shape analysis.

  9. Save the Lightcurves

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Stephens, Robert D.; Harris, Alan W.

    2011-07-01

    The lack of a central repository for asteroid time-series (lightcurve) photometry has put large amounts of data at risk of being forever lost as computers crash and the original researchers pass on. These data are vital to critical current work on theories regarding the origin and evolution of the asteroid population as a whole and of specific families/groups or types of asteroids. A first step toward creating such a repository is defining a minimum set of data and format for submitting current and future observations. The Asteroid Lightcurve Data Exchange Format (ALCDEF) has been proposed by the authors for this first step. In a recent development, the Minor Planet Center, long the recognized central repository for asteroid astrometry data, has agreed to host a site where researchers can upload and download asteroid photometry using the ALCDEF standard. We outline other steps that have been taken to have the ALCDEF standard generally accepted as well as describe a new gateway web site that leads to the ALCDEF pages as well as the Collaborative Asteroid Lightcurve Link (CALL) site commonly used by many asteroid photometrists.

  10. Lightcurves of Extreme Debris Disks

    NASA Astrophysics Data System (ADS)

    Rieke, George; Meng, Huan; Su, Kate

    2012-12-01

    We have recently discovered that some planetary debris disks with extreme fractional luminosities are variable on the timescale of a few years. This behavior opens a new possibility to understand planet building. Two of the known variable disks are around solar-like stars in the age range of 30 to 100+ Myr, which is the expected era of the final stages of terrestrial planet building. Such variability can be attributed to violent collisions (up to ones on the scale of the Moon-forming event between the proto-Earth and another proto-planet). The collisional cascades that are the aftermaths of these events can produce large clouds of tiny dust grains, possibly even condensed from silica vapor. A Spitzer pilot program has obtained the lightcurve of such a debris disk and caught two minor outbursts. Here we propose to continue the lightcurve monitoring with higher sampling rates and to expand it to more disks. The proposed time domain observations are a new dimension of debris disk studies that can bring unique insight to their evolution, providing important constraints on the collisional and dynamical models of terrestrial planet formation.

  11. Potential Biases In Future Asteroid Lightcurve Surveys

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Harris, A. W.

    2010-10-01

    A goal of recent and upcoming surveys is securing a large number of asteroid rotation periods via lightcurves. While a worthwhile effort, the "shotgun” approach being applied in many cases may not add significant new information about rotation rates and be biased against critical types of objects: fast/slow rotators, binary and multiple asteroids, and tumblers. We examined different observing strategies to determine the success rate for finding the correct period and how they might be biased against critical objects by generating 11,000 synthetic lightcurves combined into 2,500 composite curves covering a range of periods from 0.3 to 400 hours and amplitudes from 0.1 to 2.0 magnitudes and included random noise. These lightcurves were "sampled” to approximate existing and planned strategies. As with studies by Mann et al. and Masiero et al., we found a high success rate with lightcurves of relatively short periods and moderate to high amplitudes - P ≤ 8 h, A ≥ 0.3 mag - especially if "success” included finding a period that was 0.5x or 2.0x the true period. On the other hand, many lightcurves of low amplitude and long period - P ≥ 24 h, A ≤ 0.1 mag - were initially found to have periods of P ≤ 1 h which, if adopted, would badly skew rotational statistics. Overall, we found that relying on minimum of data, even if obtained over one more weeks, did not produce a significant percentage of statistically useful periods and there was a strong potential for biases against critical types of objects. A better method to advance our understanding of rotation rate and evolution and the underlying causes appears to be to concentrate on a more limited number of objects and follow each one until a reasonable solution is found.

  12. Lightcurve Analysis of Six Asteroids

    NASA Astrophysics Data System (ADS)

    Garceràn, Alfonso Carreño; Macias, Amadeo Aznar; Mansego, Enrique Arce; Rodriguez, Pedro Brines; de Haro, Juan Lozano

    2015-10-01

    Photometric observations of six asteroids were made from 2015 March to May. We report the results of our lightcurve analysis for 425 Cornelia, 625 Xenia, 664 Judith, 785 Bredichina, 910 Anneliese, and 1831 Nicholson.

  13. Asteroid Lightcurve Photometry

    NASA Astrophysics Data System (ADS)

    Harris, A. W.

    2004-05-01

    With the advent of modestly priced CCD cameras and computer controller and reduction software, amateurs can now do photometry on fainter targets than was possible even from large observatories only a decade or so ago. This has led to an explosion of lightcurve data that in turn has yielded rich results. We now have rotation periods for more than 1500 asteroids, extending down to objects only tens of meters in diameter, and well determined shapes and pole orientations of more than 100 objects. Among smaller asteroids, the dispersion in rotation rates ranges from minutes to months, with the slower ones mostly "tumbling," or in states of non-principal axis rotation. The fastest ones must be monolithic, as centrifugal force exceeds their gravity. But among those larger than a few hundred meters diameter, there is a "rotation barrier" at the rate where gravity and centrifugal force match, suggesting that most asteroids this large or larger are "rubble piles." The broad dispersion in spin rates, almost a bimodal distribution, has long been a mystery, but now appears likely to be due to thermal radiation torques from the randomly asymmetric shapes of small asteroids. This is a major paradigm shift from the past, where mutual collisions were considered to be the dominant (or only) evolutionary process affecting spins. Amateur observations have already contributed a great deal leading to this new view, and much remains to be done, providing abundant opportunities for amateur-professional collaborations.

  14. Initial Efforts at Asteroid Lightcurve Inversion

    NASA Astrophysics Data System (ADS)

    Warner, B. D.

    2007-05-01

    The problem of determining the shape of an asteroid from its lightcurve has been studied for many years. Henry Norris Russell presented a paper in 1906 that said it couldn't be done with any certainty. However, further study during the 20th century said otherwise and several methods were developed that had various levels of success. In the last several years, many asteroid shape and spin axis models have been produced using methods pioneered by Mikko Kaasalainen and others. The author has converted the original FORTRAN and C code of Kaasalainen and Durech so that it is available to anyone wanting to develop their own inversion program. Models based on lightcurves the author and others have obtained are shown.

  15. Inversion methods for interpretation of asteroid lightcurves

    NASA Technical Reports Server (NTRS)

    Kaasalainen, Mikko; Lamberg, L.; Lumme, K.

    1992-01-01

    We have developed methods of inversion that can be used in the determination of the three-dimensional shape or the albedo distribution of the surface of a body from disk-integrated photometry, assuming the shape to be strictly convex. In addition to the theory of inversion methods, we have studied the practical aspects of the inversion problem and applied our methods to lightcurve data of 39 Laetitia and 16 Psyche.

  16. SuperWASP Lightcurves of Subdwarf Stars

    NASA Astrophysics Data System (ADS)

    Maxted, P. F. L.; Norton, A. J.; West, R. G.; Copperwheat, C.; Marsh, T. R.

    SuperWASP is a wide angle survey for transiting hot-Jupiter exoplanets around bright (V<13) solar-type stars. Lightcurves for millions of stars with a few thousand observations per star are available in the SuperWASP archive. We report the results of a search for periodic variable subdwarf stars in the data from the 2004 observing season. A Fourier transform of the SuperWASP lightcurve for Balloon 090100001 recovers the main pulsation frequency of this star. No new pulsators are found among the stars studied (about 200 objects). The binary sdB star HS 2333+3927 with a large reflection effect was recovered. We find that the hot subdwarf PG 1348+369 is variable with a period of 3.316days and a semi-amplitude of 13%. Follow-up spectroscopy shows that this variation is due to irradiation of a cool companion star in a binary system.

  17. Lightcurve Analysis of 1654 Bojeva

    NASA Astrophysics Data System (ADS)

    Hayes-Gehrke, Melissa N.; Austin, Devona; Bowers, Carl; Cleary, Andrew; Dilks, Andrew; Dzurilla, Anne; Friedenberg, Meir; Isakower, Sadie; Davy-Coore, Kaydra; Kee, Andrew; Leonhartt, Greg; Rajpara, Sumit; Ricciardi, Christine; Wolf, Jacob; Zohery, Vivian

    2016-04-01

    Photometric observations of main-belt asteroid 1654 Bojeva were made over six nights during 2015 October and November. Remote observations were made using iTelescope Observatory (MPC H06) in Mayhill, New Mexico. Lightcurve analysis using MPO Canopus found a possible rotation period of 10.5559 ± 0.0137 h with an amplitude of 0.27 mag.

  18. Lightcurve Analysis of 2813 Zappala

    NASA Astrophysics Data System (ADS)

    Franco, Lorenzo; Klinglesmith, Daniel A., III; Marchini, Alessandro

    2016-07-01

    Photometric observations of the main-belt asteroid 2813 Zappala were made over ten nights in 2016 Jan-Feb. Lightcurve analysis shows a bimodal solution with a synodic period of 18.231 ± 0.001 hours and an amplitude of 0.28 ± 0.03 mag. From photometric sparse data, we also derived H = 10.99 ± 0.05 and G = 0.31 ± 0.06.

  19. Supernova Photometric Lightcurve Classification

    NASA Astrophysics Data System (ADS)

    Zaidi, Tayeb; Narayan, Gautham

    2016-01-01

    This is a preliminary report on photometric supernova classification. We first explore the properties of supernova light curves, and attempt to restructure the unevenly sampled and sparse data from assorted datasets to allow for processing and classification. The data was primarily drawn from the Dark Energy Survey (DES) simulated data, created for the Supernova Photometric Classification Challenge. This poster shows a method for producing a non-parametric representation of the light curve data, and applying a Random Forest classifier algorithm to distinguish between supernovae types. We examine the impact of Principal Component Analysis to reduce the dimensionality of the dataset, for future classification work. The classification code will be used in a stage of the ANTARES pipeline, created for use on the Large Synoptic Survey Telescope alert data and other wide-field surveys. The final figure-of-merit for the DES data in the r band was 60% for binary classification (Type I vs II).Zaidi was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program (AST-1262829).

  20. Near-Earth Asteorid Lightcurve Analysis at CS3-Palmer Divide Station: 2016 January-April

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.

    2016-07-01

    Lightcurves for 38 near-Earth asteroids (NEAs) were obtained at the Center for Solar System Studies-Palmer Divide Station (CS3-PDS) from 2016 January-April. Also reported are 4 lightcurves obtained from 2014-2015 that were not previously published.

  1. Lightcurve Photometry Opportunities: 2016 July-September

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Harris, Alan W.; Durech, Josef; Benner, Lance A. M.

    2016-07-01

    We present lists of asteroid photometry opportunities for objects reaching a favorable apparition and having either none or poorly-defined lightcurve parameters. Additional data on these objects will help with shape and spin axis modeling via lightcurve inversion. We also include lists of objects that will be the target of radar observations. Lightcurves for these objects can help constrain pole solutions and/or remove rotation period ambiguities that might not come from using radar data alone.

  2. The complex lightcurve of 1992 NA

    NASA Technical Reports Server (NTRS)

    Wisniewski, Wieslaw Z.; Harris, A. W.

    1994-01-01

    Amor asteroid 1992 NA was monitored during three nights at a large phase angle of -65 deg. The lightcurves obtained did not reveal a repeatable curve with two maxima and two minima. However, some features suggested a periodicity with three maxima and three minima. A satisfactory composite lightcurve of this form was obtained by means of an 'eyeball' fit and by Fourier analysis. Individual and composite lightcurves are presented. The observed colors are consistent with the C class.

  3. Lightcurve Photometry Opportunities: 2016 April-June

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Harris, Alan W.; Durech, Josef; Benner, Lance A. M.

    2016-04-01

    We present lists of asteroid photometry opportunities for objects reaching a favorable apparition and having either none or poorly-defined lightcurve parameters. Additional data on these objects will help with shape and spin axis modeling via lightcurve inversion. We also include lists of objects that will be the target of radar observations. Lightcurves for these objects can help constrain pole solutions and/or remove rotation period ambiguities that might not come from using radar data alone.

  4. Rotation lightcurves of small jovian Trojan asteroids

    NASA Astrophysics Data System (ADS)

    French, Linda M.; Stephens, Robert D.; Coley, Daniel; Wasserman, Lawrence H.; Sieben, Jennifer

    2015-07-01

    Several lines of evidence support a common origin for, and possible hereditary link between, cometary nuclei and jovian Trojan asteroids. Due to their distance and low albedos, few comet-sized Trojans have been studied. We present new lightcurve information for 19 Trojans ≲ 30 km in diameter, more than doubling the number of objects in this size range for which some rotation information is known. The minimum densities for objects with complete lightcurves are estimated and are found to be comparable to those measured for cometary nuclei. A significant fraction (∼40%) of this observed small Trojan population rotates slowly (P > 24 h), with measured periods as long as 375 h (Warner, B.D., Stephens, R.D. [2011]. Minor Planet Bull. 38, 110-111). The excess of slow rotators may be due to the YORP effect. Results of the Kolmogorov-Smirnov test suggest that the distribution of Trojan rotation rates is dissimilar to those of Main Belt Asteroids of the same size. Concerted observations of a large number of Trojans could establish the spin barrier (Warner, B.D., Harris, A.W., Pravec, P. [2009]. Icarus 202, 134-146), making it possible to estimate densities for objects near the critical period.

  5. The unusual lightcurve of 1990 TR

    NASA Technical Reports Server (NTRS)

    Wisniewski, Wieslaw Z.

    1992-01-01

    Amor asteroid 1990 TR was monitored during three nights shortly after discovery. Obtained lightcurves did not reveal a repeatable curve with two maxima and two minima. However, some features suggest periodicity, and a synodic rotational period P = 6.25 hours was determined. Individual and composite lightcurves are presented. The colors are best represented by the class S.

  6. Dielectric cure monitoring: Preliminary studies

    NASA Technical Reports Server (NTRS)

    Goldberg, B. E.; Semmel, M. L.

    1984-01-01

    Preliminary studies have been conducted on two types of dielectric cure monitoring systems employing both epoxy resins and phenolic composites. An Audrey System was used for 23 cure monitoring runs with very limited success. Nine complete cure monitoring runs have been investigated using a Micromet System. Two additional measurements were performed to investigate the Micromet's sensitivity to water absorption in a post-cure carbon-phenolic material. While further work is needed to determine data significance, the Micromet system appears to show promise as a feedback control device during processing.

  7. Pluto's lightcurve: Results from four oppositions

    NASA Technical Reports Server (NTRS)

    Tholen, David J.; Tedesco, Edward F.

    1994-01-01

    The rotational lightcurve, phase function, and orbital lightcurve of the Pluto-Charon system were measured in blue light over four consecutive oppositions spanning 1980 to 1983. Compared with observations made in the three previous decades, our lightcurve shows a higher amplitude of 0.29 mag, as well as a fainter rotationally averaged brightness, which provide constraints on the surface albedo distribution of the two bodies. The synodic rotational period of 6.38726 +/- 0.00007 days is consistent with the orbital period of Charon, which provides evidence for a completely tidally evolved system. The phase coefficient is 0.0372 +/- 0.0016 mag/deg, indicating a very shallow opposition surge compared with asteroids, but consistent with a high albedo surface. The orbital lightcurve shows substantially less fading than the earlier observations, which suggests that there is not a gross difference in average albedo between the southern and northern hemispheres.

  8. KBO Binarity and Spin from Visible Lightcurves

    NASA Astrophysics Data System (ADS)

    Stansberry, John A.; Trilling, David; Grundy, Will; Muller, Michael; Muller, Thomas

    2008-08-01

    We propose to obtain rotational lightcurves for a sample of cold- classical KBOs using GMOS-N and/or GMOS-S during a total of 2 nights in ``poor weather'' conditions. We have completed a pilot program (using GMOS-S DD time) showing that we can take advantage of such conditions to do lightcurve work using background sources in the images to track transparency and seeing variations. The (detected) lightcurves will provide the rotational period. If the amplitudes are large, they also give a rough constraint on the pole position. Rotational lightcurves can also be used to discover binary systems, as seen for main-belt asteroids. Our measurements will significantly improve our ability to model thermal observations of the targets, either from Spitzer or to be obtained through an approved Herschel program. Modeling of those thermal data will produce diameters and albedos, but the results depend on the rotation rate (through the thermal parameter), and pole orientation, so constraints on either or both help reduce systematic uncertainties. The derived size also depends critically on whether the object is binary. The cold-classicals contain a very high fraction (~eq 30%) of binaries: we are more likely to discover binaries there (the first discovered by lightcurve signature), and more likely to provide a useful input (i.e. confirmed binary, or upper limit on companion size) to our Spitzer and Herschel programs.

  9. Assessment of stochastic and deterministic models of 6304 quasar lightcurves from SDSS Stripe 82

    NASA Astrophysics Data System (ADS)

    Andrae, R.; Kim, D.-W.; Bailer-Jones, C. A. L.

    2013-06-01

    The optical lightcurves of many quasars show variations of tenths of a magnitude or more on timescales of months to years. This variation often cannot be described well by a simple deterministic model. We perform a Bayesian comparison of over 20 deterministic and stochastic models on 6304 quasi-steller object (QSO) lightcurves in SDSS Stripe 82. We include the damped random walk (or Ornstein-Uhlenbeck [OU] process), a particular type of stochastic model, which recent studies have focused on. Further models we consider are single and double sinusoids, multiple OU processes, higher order continuous autoregressive processes, and composite models. We find that only 29 out of 6304 QSO lightcurves are described significantly better by a deterministic model than a stochastic one. The OU process is an adequate description of the vast majority of cases (6023). Indeed, the OU process is the best single model for 3462 lightcurves, with the composite OU process/sinusoid model being the best in 1706 cases. The latter model is the dominant one for brighter/bluer QSOs. Furthermore, a non-negligible fraction of QSO lightcurves show evidence that not only the mean is stochastic but the variance is stochastic, too. Our results confirm earlier work that QSO lightcurves can be described with a stochastic model, but place this on a firmer footing, and further show that the OU process is preferred over several other stochastic and deterministic models. Of course, there may well exist yet better (deterministic or stochastic) models, which have not been considered here.

  10. Analysis from Stellar Occultation and Lightcurve Observation of 582 Olympia

    NASA Astrophysics Data System (ADS)

    Matsuoka, Y.; Okamoto, R.; Sugimoto, S.; Mayu Shibata; Watanabe, D.

    2012-05-01

    Our aim is to estimate 3D shape of an asteroid. We tried to find the shape of 582 Olympia. We conducted two observations: stellar occulation and lightcurve of an asteroid. We have observed lightcurves and occultations of several asteroid.

  11. Asteroid Lightcurve Analysis at Riverland Dingo Observatory (RDO)

    NASA Astrophysics Data System (ADS)

    Hills, Kevin

    2016-01-01

    Lightcurves for four asteroids selected from the Collaborative Asteroid Lightcurve Link (CALL) were obtained at RDO in the period 2014 May-November: 1794 Finsen, 2476 Andersen, 3296 Bosque Alegre, and 8159 Fukuoka.

  12. Analysis of the Lightcurve of 1101 Clematis

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Stephens, Robert D.

    2010-04-01

    We report on our collaboration to obtain photometric data on the outer main-belt asteroid, 1101 Clematis. Data obtained in 2009 September yield a synodic rotation period of 34.3 ± 0.1 h and lightcurve amplitude of 0.16 ± 0.02 mag. The period spectrum shows a possible period at ~18.4 h but the phased lightcurve plot shows this solution is unlikely. The period of 34.3 h differs significantly from previously reported results.

  13. The BVRI and methane lightcurve of Triton in 2003

    NASA Astrophysics Data System (ADS)

    Schmidt, B.; Herbert, B.; Bauer, J. M.; Hicks, M. D.; Buratti, B. J.; Young, J.

    2003-12-01

    Photometric measurements of Triton in the BVRI and 890 nm filter system were obtained in June, July, and (tentatively) early August 2003. The motivation for these measurements was to confirm the recent observation that the lightcurve of Triton has increased markedly in amplitude (Cobb et al. B.A.A.S 33, 1130 (2001)). If the albedo patterns on Triton remained unchanged since the Voyager encounter in 1989, the current amplitude of Triton's visual lightcurve should be less than 0.05 magnitudes (Hillier et al., JGR 96, 19211). Measurements in 2001 showed an amplitude of nearly 0.20 magnitudes (Cobb et al., op. cit.), indicating volatile transport on the surface. Changes in Triton's color (Hicks et al., 2003, accepted for publication in Icarus), and atmospheric pressure and temperature (Elliot et al., Icarus 148, 347 (2000)) also support the existence of sublimation and possible movement of volatiles and associated changes in albedo patterns. The preliminary analysis of data from the summer of 2003 shows a visual amplitude of 0.17 +/- 0.05 magnitudes, in good agreement with the results from 2001, and far larger than that expected if there were no change in the albedo patterns on Triton's surface. Work carried out at Jet Propulsion Laboratory, California Inst. of Technology, with funding from NASA.

  14. Spin Axis Distribution of the Hungaria Asteroids via Lightcurve Inversion

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Harris, Alan W.; Stephens, Robert D.; Coley, Daniel

    2014-11-01

    Since 2005, we have conducted a dedicated campaign to obtain dense lightcurves of members of the Hungaria asteroid population. As a result, the number of Hungarias in the asteroid lightcurve database (LCDB; Warner et al., 2009; Icarus 202, 134-146) with a statistically valid rotation rate rose from less than 50 to almost 300. The particular value of the Hungarias is that they are smallest and closest-to-sun main belt objects that can be studied with modest-sized telescopes. As such, they are more likely subject to YORP-altered spin states. We have previously verified highly-evolved rotation rates (Warner et al., 2009; Icarus 204, 172-182). This study takes the next step of tracing the evolution of spin orientations. We combined the dense lightcurves from our campaign with so-called “sparse data” from the NEA surveys to model the spin axis orientation using lightcurve inversion methods (see works by Kaasalainen, Torppa, Durech, and Hanus). Because high-dispersion sparse data are of little use for low amplitude objects, we limited the Hungarias to be modeled to those with a maximum amplitude of A ≥ 0.15 mag, an LCDB reliability code of U ≥ 2, the period in the LCDB summary was unambiguous, and the asteroid did not show signs of tumbling (non-principal axis rotation). The result as of mid-August 2014 was a list of 231 Hungaria candidates for modeling. Using a bank of five independent desktop computers and customized software, we first determined the likely sidereal period of the asteroid. That period was then used for a spin axis (pole) search involving 315 discrete longitude-latitude pairs. We report on the results of our searches, including weighting solutions when a unique solution was not found (often the case in lightcurve inversion), and how the results compare to similar studies using a more general asteroid population. BDW and AWH acknowledge funding from NASA NNX13AP56G and NSF grant AST-1210099. RDS acknowledges NASA grant NNX13AP56G and the

  15. Lightcurve and period determination for 582 Olympia

    NASA Astrophysics Data System (ADS)

    Higgins, David; Menke, John; Pozzoli, Valentino; Sheridan, Edwin; Dymock, Roger

    2004-03-01

    Minor planet 582 Olympia was observed over a period of 40 days from 9 February to 20 March 2003. More than 3000 data points from 42 sessions were obtained by 5 observers. The lightcurve obtained shows a rotational (synodic) period of 72.0 ± 0.5 hrs with amplitude of 0.20 ± 0.05 mag.

  16. Lightcurves for 25 Irregular Satellites of Saturn

    NASA Astrophysics Data System (ADS)

    Denk, Tilmann; Mottola, Stefano

    2015-11-01

    This abstract reports rotational-lightcurve observations of irregular moons of Saturn based on disk-integrated observations with the Narrow-Angle Camera of the Cassini spacecraft. For 16 objects, synodic rotation periods have been derived at <1% accuracy, for 6 others at lower accuracy or with an ambiguity with respect to the amount of maxima and minima. The average of all 22 measured periods lies between 16 and 19 h. For the 19 objects with periods faster than 24 h, the average is ~12.5 h.The objects were observed at phase angles between 2° and 143°. Among the lightcurves obtained at low phases (< ~45°), ~85% exhibit 2 maxima and 2 minima, while only ~15% show 3max/3min. For mid-phase lightcurves (~45° to ~90°), the ratio between 2max/2min and 3max/3min lightcurves is almost equal. At high phases (> ~90°), only ~1/3 of the lightcurves display 2max/2min, while ~2/3 show 3max/3min or even 4max/4min. For low- and mid-phase angles, the lightcurve amplitudes clearly increase with increasing phase. While ~50% of the objects show lightcurves with amplitudes below ~0.4 mag at low phases, we found almost no such small amplitudes for mid and high phases. Between mid- and high-phase angles, the trend of magnitude increase lessens. The most extreme measured amplitudes were ~2.5 mag.No object with a period close to the spin barrier for Main Belt asteroids (~2.3 h) was detected. By assuming a bulk density of the Saturnian irregulars of ~1 g cm-3, the fastest measured period of 5.5 h would be close to the spin barrier for these objects.A comparison of the irregular moons' rotation periods with five orbit parameters indicates possible weak correlations with two of them: Periapses and co-latitude of the orbit pole (i' with i' = i for prograde, i' = 180°-i for retrograde moons; i is the object's orbit inclination). For moons with orbits of high i' > ~27°, no fast rotator (P < 10 h) has been found, and their average rotation period is ~1.7x longer than for the low-i' objects

  17. Properties of GRB Lightcurves from Magnetic Reconnection

    NASA Astrophysics Data System (ADS)

    Beniamini, Paz; Granot, Jonathan

    2016-04-01

    The energy dissipation mechanism within Gamma-Ray Burst (GRB) outflows, driving their extremely luminous prompt γ-ray emission is still uncertain. The leading candidates are internal shocks and magnetic reconnection. While the emission from internal shocks has been extensively studied, that from reconnection still has few quantitative predictions. We study the expected prompt-GRB emission from magnetic reconnection and compare its temporal and spectral properties to observations. The main difference from internal shocks is that for reconnection one expects relativistic bulk motions with Lorentz factors Γ' ≳ a few in the jet's bulk frame. We consider such motions of the emitting material in two anti-parallel directions (e.g. of the reconnecting magnetic-field lines) within an ultra-relativistic (with Γ ≫ 1) thin spherical reconnection layer. The emission's relativistic beaming in the jet's frame greatly affects the light-curves. For emission at radii R0 < R < R0 + ΔR (with Γ = const) the observed pulse width is ΔT ˜ (R0/2cΓ2) max (1/Γ', ΔR/R0), i.e. up to ˜Γ' times shorter than for isotropic emission in the jet's frame. We consider two possible magnetic reconnection modes: a quasi steady-state with continuous plasma flow into and out of the reconnection layer, and sporadic reconnection in relativistic turbulence that produces relativistic plasmoids. Both of these modes can account for many observed prompt-GRB properties: variability, pulse asymmetry, the very rapid declines at their end and pulse evolutions that are either hard to soft (for Γ' ≲ 2) or intensity tracking (for Γ' > 2). However, only the relativistic turbulence mode can naturally account also for the following correlations: luminosity-variability, peak luminosity - peak frequency and pulse width energy dependence / spectral lags.

  18. Lightcurve photometry of asteroid 808 Merxia

    NASA Astrophysics Data System (ADS)

    Koff, Robert A.; Brown, Janel; Menke, John

    2003-09-01

    This is a report on a lightcurve measurement project at Antelope Hills Observatory and Starlight Farm Observatory. Observations for this project were carried out for a science fair project by high school student Janel Brown. Asteroid 808 Merxia was found to have a synodic period of 30.631 hours ± 0.001 hours and an amplitude of 0.81 ± 0.02 magnitude.

  19. Preliminary study for the OFFELO

    SciTech Connect

    Hao, Y.; Litvinenko, V.N.

    2010-08-23

    X-ray Optics-Free FEL Oscillator (OFFELO) has potential of becoming a choice for next generation light sources. Using electron beam for the feedback allows OFFELO to be completely tunable and to combine the peak power of high-gain SASE FELs with extremely narrow bandwidth of the oscillator. While the high-gain X-ray FELs has been studied in depth and has been successfully demonstrated, two other concepts (the transport and the feed-back) involved in OFFELO still need detail studies. In this short paper we focus on the simulation of the feedback process and the evolution of FEL spectrum in X-ray OFFELO. In our initial studies of OFFELO studied the saturation of the system and also its evolution using Genesis 2.0 code with a homemade wrapping code. While and lattice design from the modulator to the radiator, in order to minimize the feedback information loss in transporting the beam.

  20. Cuban Identity: A Preliminary Study.

    ERIC Educational Resources Information Center

    Alvarez, Carlos; Bliss, Linda A.; Vigil, Peter

    This study explored patterns of differences and commonalities in the constructions of identity by Cuban Americans, focusing on the pain of their experiencing "Paradise Lost," a theme identified in earlier research in which Cuban American college students reported: strong Cuban connections; value for the Spanish language, food, and culture; and a…

  1. Preliminary design study of lunar housing configurations

    NASA Technical Reports Server (NTRS)

    Reynolds, K. H.

    1992-01-01

    A preliminary design study assesses various configurations for habitation of the lunar surface. The study assumes an initial 4-man habitation module expandable to a 48-man concept. Through the numerous coupling combinations of identical modules, five basic configuration types are identified. A design model presents each configuration in light of certain issues. The issues include circulation, internal and external spatial characteristics, functional organizations, and future growth potential. The study discusses the attributes, potentials, and unique requirements of each configuration.

  2. Galaxy collisions - A preliminary study

    NASA Technical Reports Server (NTRS)

    Miller, R. H.; Smith, B. F.

    1980-01-01

    Collisions of spherical galaxies were studied in a series of numerical experiments to see what happens when galaxies collide. Each experiment starts with two model galaxies, each consisting of 50,000 stars, moving toward each other along a specified orbit. The series of experiments provides a systematic sampling of the parameter space spanned by the initial orbital energy and the initial angular momentum. Deeply penetrating collisions are emphasized. The collisions reported here scale to relative velocities as great as 500 km/s, well into the range for collisions within clusters of galaxies. It is found that: (1) the galaxies contract momentarily to about half their original sizes shortly after close passage; and (2) the initial galaxies blend into a single dynamical system while they are near each other.

  3. The Lightcurve Legacy of COS and STIS

    NASA Astrophysics Data System (ADS)

    Ely, Justin

    2014-10-01

    The Cosmic Origin Spectrograph {COS} and Space Telescope Imaging Spectrograph {STIS} have been advancing astronomy with high quality spectroscopic products for years, and in the case of STIS, more than a decade. Though already incredibly productive, there remains an untapped potential of discovery in the data of these instruments. Due to their detector designs, both of these instruments can operate in a mode where each indivudal photon's arrival time is recorded and saved. Though this TIME-TAG ability is typically utilized to provide second-by-second calibrations to the final spectral data, this mode can also be exploited to re-examine the data in the time domain, turning spectra into lightcurves. With the appropriate knowledge and software, the time-resolved spectra can instead be extracted into photometric lightcurves with high temporal and spectral resolution.We propose here to expand our current software tool into a community-ready pipeline and to deliver a collection of high-level science lightcurves for the entire COS and STIS TIME-TAG archives. By providing this tool and data archive to the community we will lower the barrier to time domain research with these two instruments. This will demonstrate to the community not only the potential contained in re-analysis of existing datasets, but also the exquisite time-series capabilities of the instruments available for future cycles. The enabling and demonstration of this so far underutilized technique should be done now. At a time when HST and its UV capabilities are nearing their end, it's vital that all possible avenues for exploration are made readily available to the scientific community.

  4. Lightcurve Photometry Opportunities: January-March 2009

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Harris, Alan W.; Pravec, Petr; Durech, Josef; Benner, Lance A. M.

    2009-01-01

    We present here four lists of “targets of opportunity” for the period 2009 January - March. The first list is those asteroids reaching a favorable apparition during this period, are <15m at brightest, and have either no or poorly constrained lightcurve parameters. By “favorable” we mean the asteroid is unusually brighter than at other times and, in many cases, may not be so for many years. The goal for these asteroids is to find a welldetermined rotation rate. Don’t hesitate to solicit help from other observers at widely spread longitudes should the initial findings show that a single station may not be able to finish the job.

  5. Lightcurve Photometry Opportunities: 2009 October-December

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Harris, Alan W.; Pravec, Petr; Durech, Josef; Benner, Lance A. M.

    2009-10-01

    We present four lists of “targets of opportunity” for the period 2009 October-September. The first list is those asteroids reaching <15m at brightest during the period and have either no or poorly constrained lightcurve parameters. In some cases, the asteroid may not be favorably positioned again for many years, if ever. The goal for these asteroids is to find a well-determined rotation rate. Don’t hesitate to solicit help from other observers at widely spread longitudes should the initial findings show that a single station may not be able to finish the job.

  6. Asteroid Lightcurve Analysis at Riverland Dingo Observatory (RDO)

    NASA Astrophysics Data System (ADS)

    Hills, Kevin

    2014-07-01

    Lightcurves for five asteroids selected from the Collaborative Asteroid Lightcurve Link (CALL) were obtained at RDO in the period 2013 September 15 - 2014 March 30: 3992 Wagner, 4511 Rembrandt, (6652) 1991 SJ1, (16009) 1999 CM8, and (98889) 2001 BL38.

  7. Lightcurves from the Initial Discovery of Four Hungaria Binary Asteroids

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Pravec, Petr; Kusnirak, Peter; Harris, Alan W.; Cooney, Walter R., Jr.; Gross, John; Terrell, Dirk; Nudds, Shannon; Vilagi, Josef; Gajdos, Stefan; Masi, Gianluca; Pray, Donald P.; Dyvig, Ron; Reddy, Vishnu

    2011-04-01

    Lightcurves from the initial discovery of four Hungaria binary asteroids are presented: 3309 Brorfeld, (5477) 1989 UH2, 9069 Hovland, and (76818) 2000 RG79. Announcements and some web postings were made at the time of the discoveries but the lightcurves were not formally published.

  8. Asteroid Lightcurve Analysis at Isaac Aznar Observatory Aras De Los Olmos, Valencia, Spain

    NASA Astrophysics Data System (ADS)

    Macias, Amadeo Aznar

    2015-01-01

    The Isaac Aznar Observatory conducts astrometric and photometric studies of asteroids. This paper contains the photometric results of four asteroids obtained from 2014 April to August. These asteroids were selected from the Collaborative Asteroid Lightcurve Link (CALL) web site: 1088 Mitaka, 2956 Yeomans, 3894 Williamcooke, and (4555) 1974QL.

  9. The Lightcurve Legacy of COS and STIS

    NASA Astrophysics Data System (ADS)

    Ely, Justin; Bourque, Matthew; Debes, John; Kriss, Gerard; McCullough, Peter R.

    2015-08-01

    The Cosmic Origin Spectrograph (COS) and Space Telescope Imaging Spectrograph (STIS) onboard the Hubble Space Telescope (HST) have been advancing astronomy with high quality spectroscopic products for years, and in the case of STIS, more than a decade. Though already incredibly productive, there remains an untapped potential of discovery in the data of these instruments. Due to their specific detector designs, both of these instruments can operate in a TIME-TAG mode where each individual photon's arrival time is recorded. Though this ability is typically utilized to provide second-by-second calibrations to the final spectral data, this mode can also be exploited to re-examine the data in the time domain, turning spectra into lightcurves with high temporal and spectral resolution.Nearly all COS and many STIS observations are taken in TIME-TAG mode. For observations that were not specifically designed to carry out time-resolved spectroscopy, the archived data represent an untapped space for discovery. We present here the current status of our on-going efforts to produce a collection of high-level science lightcurves for the entire COS and STIS TIME-TAG archives. Included are details of the time-series reduction software, instrument capabilities in the time-domain, and demonstrations of the current reduced products for a wide range of variable targets such as transits, stellar flares, and white dwarf pulsations.

  10. Preliminary summary of the ETF conceptual studies

    NASA Technical Reports Server (NTRS)

    Seikel, G. R.; Bercaw, R. W.; Pearson, C. V.; Owens, W. R.

    1978-01-01

    Power plant studies have shown the attractiveness of MHD topped steam power plants for baseload utility applications. To realize these advantages, a three-phase development program was initiated. In the first phase, the engineering data and experience were developed for the design and construction of a pilot plant, the Engineering Test Facility (ETF). Results of the ETF studies are reviewed. These three parallel independent studies were conducted by industrial teams led by the AVCO Everett Research Laboratory, the General Electric Corporation, and the Westinghouse Corporation. A preliminary analysis and the status of the critical evaluation of these results are presented.

  11. Spin-axis distribution of the Hungaria asteroids via lightcurve inversion

    NASA Astrophysics Data System (ADS)

    Warner, B.; Harris, A.; Stephens, R.; Coley, D.

    2014-07-01

    Since 2005, we have conducted a dedicated campaign to obtain dense lightcurves of members of the Hungaria asteroid population. As a result, the number of Hungarias in the asteroid lightcurve database (LCDB; Warner et al. [1]) with a statistically valid rotation rate rose from less than 50 to almost 300. The particular value of the Hungarias is that they are smallest and closest-to-sun main belt objects that can be studied with modest-sized telescopes. As such, they are more likely subject to YORP-altered spin states. We have previously verified highly-evolved rotation rates within the Hungarias (Warner et al. [2]). This study takes the next step of tracing the evolution of spin orientations. We combined the dense lightcurves from our campaign with so-called "sparse data" from the NEA surveys to model the spin axis orientation using lightcurve inversion methods (see works by Kaasalainen, Torppa, Durech, and Hanus). Because high-dispersion sparse data are of little use for low amplitude objects, we limited the Hungarias to be modeled to those with a maximum amplitude of A >= 0.15 mag, an LCDB reliability code of U >= 2, the period in the LCDB summary was unambiguous, and the asteroid did not show signs of tumbling (non-principal axis rotation). The result as of early February 2014 was a list of 227 of Hungaria candidates for modeling. Using a bank of five independent desktop computers and customized software, we first determined the likely sidereal period of the asteroid. That period was then used for spin axis (pole) search involving 315 discrete longitude-latitude pairs. The result of one such search is shown in the figure. We report on the results of our searches, including weighting solutions when a unique solution was not found (often the case in lightcurve inversion), and how the results compare to similar studies using a more general asteroid population.

  12. Lightcurve Photometry Opportunities: 2009 April-June

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Harris, Alan W.; Pravec, Petr; Durech, Josef; Benner, Lance A. M.

    2009-04-01

    We present here four lists of “targets of opportunity” for the period 2009 April-June. The first list is those asteroids reaching a favorable apparition during this period, are <15m at brightest, and have either no or poorly constrained lightcurve parameters. By “favorable” we mean the asteroid is unusually brighter than at other times and, in many cases, may not be so for many years. The goal for these asteroids is to find a well-determined rotation rate. Don’t hesitate to solicit help from other observers at widely spread longitudes should the initial findings show that a single station may not be able to finish the job.

  13. Lightcurve Photometry Opportunities: April-May 2008

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Harris, Alan W.; Pravec, Petr; Kaasalainen, Mikko; Benner, Lance A. M.

    2008-06-01

    We present here four lists of “targets of opportunity” for the period 2008 April-June. The first list is those asteroids reaching a favorable apparition during this season, are <15m at brightest, and have either no or poorly constrained lightcurve parameters. By “favorable” we mean the asteroid is unusually brighter than at other times and, in many cases, may not be so for many years. The goal for these asteroids is to find a well-determined rotation rate. Don’t hesitate to solicit help from other observers at widely spread longitudes should the initial findings show that a single station may not be able to finish the job.

  14. Lightcurve Photometry Opportunities: October-December 2008

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Harris, Alan W.; Pravec, Petr; Durech, Josef; Benner, Lance A. M.

    2008-10-01

    We present here four lists of “targets of opportunity” for the period 2008 October-December. The first list is those asteroids reaching a favorable apparition during this period, are <15m at brightest, and have either no or poorly constrained lightcurve parameters. By “favorable” we mean the asteroid is unusually brighter than at other times and, in many cases, may not be so for many years. The goal for these asteroids is to find a welldetermined rotation rate. Don’t hesitate to solicit help from other observers at widely spread longitudes should the initial findings show that a single station may not be able to finish the job.

  15. Lightcurve Photometry Opportunities: 2009 July-September

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Harris, Alan W.; Pravec, Petr; Durech, Josef; Benner, Lance A. M.

    2009-07-01

    We present here four lists of “targets of opportunity” for the period 2009 July-September. The first list is those asteroids reaching a favorable apparition during this period, are <15m at brightest, and have either no or poorly constrained lightcurve parameters. By “favorable” we mean that the asteroid is brighter than 14m regardless of circumstances and/or that it is unusually bright. In some cases, a favorable apparition may not occur again for many years, if ever. The goal for these asteroids is to find a well-determined rotation rate. Don’t hesitate to solicit help from other observers at widely spread longitudes should the initial findings show that a single station may not be able to finish the job.

  16. Lightcurve Photometry Opportunities: July-September 2008

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Harris, Alan W.; Pravec, Petr; Durech, Josef; Benner, Lance A. M.

    2008-09-01

    We present here four lists of “targets of opportunity” for the period 2008 July-September. The first list is those asteroids reaching a favorable apparition during this period, are <15m at brightest, and have either no or poorly constrained lightcurve parameters. By “favorable” we mean the asteroid is unusually brighter than at other times and, in many cases, may not be so for many years. The goal for these asteroids is to find a welldetermined rotation rate. Don’t hesitate to solicit help from other observers at widely spread longitudes should the initial findings show that a single station may not be able to finish the job.

  17. Lightcurve Photometry Opportunities January-March 2008

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Harris, Alan W.; Pravec, Petr; Kaasalainen, Mikko; Benner, Lance A. M.

    2008-03-01

    We present here four lists of “targets of opportunity” for the period 2008 January-March. The first list is those asteroids reaching a favorable apparition during this period, are <15m at brightest, and have either no or poorly constrained lightcurve parameters. By “favorable” we mean the asteroid is unusually brighter than at other times and, in many cases, may not come again for many years. The goal for these asteroids is to find a well-determined rotation rate, if at all possible. Don’t hesitate to solicit help from other observers at widely spread longitudes should the initial findings show that a single station may not be able to finish the job.

  18. Lightcurve Analysis of NEA 2009 FG19

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Pray, Donald P.; Pollock, Joseph T.; Reichart, Daniel E.; Haislip, Joshua B.; LaCluyze, Aaron P.; Verveer, Ariee; Spuck, Tim; Harris, Alan W.

    2015-01-01

    CCD photometric observations of the near-Earth asteroid 2009 FG19 were made in 2014 September and October to supplement radar observations made at the same time. Analysis of the CCD data from September only found several possible periods, all commensurate with an Earth day. The most likely period was 8.00 ± 0.02 h with an amplitude of 0.80 ± 0.05 mag with an alternate solution of 9.61 ± 0.02 h being possible. The addition of data from October, even though the lightcurve had evolved noticeably, removed the 9.6 hour alias and confirmed the 8-hour solution. There were no obvious signs of nonprinciple axis rotation (NAPR; tumbling) but that cannot be formally excluded.

  19. Photometric geodesy of main-belt asteroids. III. Additional lightcurves

    SciTech Connect

    Weidenschilling, S.J.; Chapman, C.R.; Davis, D.R.; Greenberg, R.; Levy, D.H. )

    1990-08-01

    A total of 107 complete or partial lightcurves are presented for 59 different asteroids over the 1982-1989 period. Unusual lightcurves with unequal minima and maxima at large amplitudes are preferentially seen for M-type asteroids. Some asteroids, such as 16 Psyche and 201 Penelope, exhibit lightcurves combining large amplitude with very unequal brightness for both maxima and both minima, even at small phase angles. An M-type asteroid is believed to consist of a metal core of a differentiated parent body that has had its rocky mantle completely removed by one or more large impacts. 39 refs.

  20. Asteroid Lightcurve Analysis at Riverland Dingo Observatory (RDO): 2013 Results

    NASA Astrophysics Data System (ADS)

    Hills, Kevin

    2014-01-01

    Lightcurves for three asteroids selected from the Collaborative Asteroid Lightcurve Link (CALL; Warner, 2011) were obtained at the Riverland Dingo Observatory (RDO) from 2013 January 16 - July 7: 3138 Ciney, 10502 Armagahobs, and 11441 Anadiego. In addition a lightcurve for (285263) 1998 QE2 was obtained following a request for data from Lance Benner posted on the Minor Planet Mailing List (MPML) Yahoo Group on the basis that it was a radar imaging target at Arecibo and Goldstone in late 2013 May and early June.

  1. Photometric geodesy of main-belt asteroids. III - Additional lightcurves

    NASA Technical Reports Server (NTRS)

    Weidenschilling, S. J.; Chapman, C. R.; Davis, D. R.; Greenberg, R.; Levy, D. H.

    1990-01-01

    A total of 107 complete or partial lightcurves are presented for 59 different asteroids over the 1982-1989 period. Unusual lightcurves with unequal minima and maxima at large amplitudes are preferentially seen for M-type asteroids. Some asteroids, such as 16 Psyche and 201 Penelope, exhibit lightcurves combining large amplitude with very unequal brightness for both maxima and both minima, even at small phase angles. An M-type asteroid is believed to consist of a metal core of a differentiated parent body that has had its rocky mantle completely removed by one or more large impacts.

  2. Preliminary neutron crystallographic study of human transthyretin

    PubMed Central

    Haupt, Melina; Blakeley, Matthew P.; Teixeira, Susana C. M.; Mason, Sax A.; Mitchell, Edward P.; Cooper, Jonathan B.; Forsyth, V. Trevor

    2011-01-01

    Preliminary studies of perdeuterated crystals of human transthyretin (TTR) have been carried out using the LADI-III and D19 diffractometers at the Institut Laue–Langevin in Grenoble. The results demonstrate the feasibility of a full crystallographic analysis to a resolution of 2.0 Å using Laue diffraction and also illustrate the potential of using monochromatic instruments such as D19 for higher resolution studies where larger crystals having smaller unit cells are available. This study will yield important information on hydrogen bonding, amino-acid protonation states and hydration in the protein. Such information will be of general interest for an understanding of the factors that stabilize/destabilize TTR and for the design of ligands that may be used to counter TTR amyloid fibrillogenesis. PMID:22102249

  3. A preliminary neutron crystallographic study of thaumatin

    SciTech Connect

    Teixeira, Susana C. M.; Blakeley, Matthew P.; Leal, Ricardo M. F.; Mitchell, Edward P.; Forsyth, V. Trevor

    2008-05-01

    Preliminary neutron crystallographic data from the sweet protein thaumatin have been recorded using the LADI-III diffractometer at the Institut Laue Langevin (ILL). The results illustrate the feasibility of a full neutron structural analysis aimed at further understanding the molecular basis of the perception of sweet taste. Such an analysis will exploit the use of perdeuterated thaumatin. A preliminary neutron crystallographic study of the sweet protein thaumatin is presented. Large hydrogenated crystals were prepared in deuterated crystallization buffer using the gel-acupuncture method. Data were collected to a resolution of 2 Å on the LADI-III diffractometer at the Institut Laue Langevin (ILL). The results demonstrate the feasibility of a full neutron crystallographic analysis of this structure aimed at providing relevant information on the location of H atoms, the distribution of charge on the protein surface and localized water in the structure. This information will be of interest for understanding the specificity of thaumatin–receptor interactions and will contribute to further understanding of the molecular mechanisms underlying the perception of taste.

  4. Asteroid 532 Herculina - Lightcurves, pole orientation and a model

    NASA Technical Reports Server (NTRS)

    Taylor, R. C.; Birch, P. V.; Drummond, J.; Pospieszalska-Surdej, A.; Surdej, J.

    1987-01-01

    While photoelectric lightcurves obtained for 532 Herculina in 1984 exhibit two maxima and two minima, the lightcurve has shown only one maximum and one minimum over the same rotation period in some other oppositions. The use of photometric astronomy yields a sidereal period of 0.3918711 + or 0.0000001 day, with a retrograde rotation for the north pole at 276 deg longitude and +1 deg latitude. A model consisting of a sphere with two dark regions that are each about 0.13 times the brightness of the surrounding surface is developed for Herculina, and it is shown that its generated lightcurves are consistent with both the observed amplitudes and the timings of extrema over the 28,630 sidereal rotations of 30 years. The lightcurves for the next four oppositions are predicted on the basis of the photometric astrometry pole and the two dark region model.

  5. Lightcurve Analysis of Ten Main-belt Asteroids

    NASA Astrophysics Data System (ADS)

    Fauerbach, Michael; Marks, Scott A.; Lucas, Michael P.

    2008-06-01

    We report lightcurve periods for ten main-belt asteroids observed at the Evelyn L. Egan Observatory: 26 Proserpina, 78 Diana, 242 Kriemhild, 287 Nephthys, 348 May, 368 Haidea, 446 Aeternitas, 872 Holda, 905 Universitas, and 1013 Tombecka.

  6. Lightcurve Analysis of Five Taxonomic A-class Asteroids

    NASA Astrophysics Data System (ADS)

    Lucas, Michael P.; Ryan, Jeffrey G.; Fauerbach, Michael; Grasso, Salvatore

    2011-10-01

    We report lightcurve rotational periods for five taxonomic A-class asteroids observed at the Evelyn L. Egan Observatory: 246 Asporina, 289 Nenetta, 446 Aeternitas, 1600 Vyssotsky, and the Mars-crosser 1951 Lick.

  7. Asteroid Lightcurve Analysis at the Danhenge Observatory Apr - Aug 2011

    NASA Astrophysics Data System (ADS)

    Coley, Daniel

    2012-01-01

    The lightcurves for three main-belt asteroids, 1413 Roucarie, 3385 Bronnina, and 39890 Bobstephens. All observations were taken from the DanHenge Observatory, one of 13 observatories at Goat Mountain Astronomical Research Station (GMARS - MPC G79).

  8. Lightcurves and pole position of asteroid 3 Juno

    NASA Technical Reports Server (NTRS)

    Birch, P. V.; Taylor, R. C.

    1989-01-01

    Thirteen lightcurves of asteroid 3 Juno from three different oppositions are given. The pole of Juno is less than 10 deg from ecliptic longitude 104 deg and latitude + 36 deg (or 316 and + 62 deg). The sidereal period is 0.3003969 + or - 0.0000003 (1 sigma) day and the rotation is prograde. There is little similarity between the Juno lightcurves from 8 oppositions which is unexplained at this time.

  9. Longterm lightcurves of X-ray binaries

    NASA Astrophysics Data System (ADS)

    Clarkson, William

    The X-ray Binaries (XRB) consist of a compact object and a stellar companion, which undergoes large-scale mass-loss to the compact object by virtue of the tight ( P orb usually hours-days) orbit, producing an accretion disk surrounding the compact object. The liberation of gravitational potential energy powers exotic high-energy phenomena, indeed the resulting accretion/ outflow process is among the most efficient energy-conversion machines in the universe. The Burst And Transient Source Experiment (BATSE) and RXTE All Sky Monitor (ASM) have provided remarkable X-ray lightcurves above 1.3keV for the entire sky, at near-continuous coverage, for intervals of 9 and 7 years respectively (with ~3 years' overlap). With an order of magnitude increase in sensitivity compared to previous survey instruments, these instruments have provided new insight into the high-energy behaviour of XRBs on timescales of tens to thousands of binary orbits. This thesis describes detailed examination of the long-term X-ray lightcurves of the neutron star XRB X2127+119, SMC X-1, Her X- 1, LMC X-4, Cyg X-2 and the as yet unclassified Circinus X-1, and for Cir X-1, complementary observations in the IR band. Chapters 1 & 2 introduce X-ray Binaries in general and longterm periodicities in particular. Chapter 3 introduces the longterm datasets around which this work is based, and the chosen methods of analysis of these datasets. Chapter 4 examines the burst history of the XRB X2127+119, suggesting three possible interpretations of the apparently contradictory X-ray emission from this system, including a possible confusion of two spatially distinct sources (which was later vindicated by high-resolution imaging). Chapters 5 and 6 describe the characterisation of accretion disk warping, providing observational verification of the prevailing theoretical framework for such disk-warps. Chapters 7 & 8 examine the enigmatic XRB Circinus X-1 with high-resolution IR spectroscopy (chapter 7) and the RXTE

  10. Lightcurve Based Classification Of Transients Events

    NASA Astrophysics Data System (ADS)

    Donalek, Ciro; Graham, M. J.; Mahabal, A.; Djorgovski, S. G.; Drake, A. J.; Moghaddam, B.; Turmon, M.; Chen, Y.; Sharma, N.

    2012-01-01

    In many scientific fields, a new generation of instruments is generating exponentially growing data streams, that may enable significant new discoveries. The requirement to perform the analysis rapidly and objectively, coupled with the huge amount of data available, implies a need for an automated event detection, classification, and decision making. In astronomy, this is the case with the new generation of synoptic sky surveys, that discover an ever increasing number of transient events. However, not all of them are equally interesting and worthy of a follow-up with limited resources. This presents some unusual classification challenges: the data are sparse, heterogeneous and incomplete; evolving in time; and most of the relevant information comes from a variety of archival data and contextual information. We are exploring a variety of machine learning techniques, using the ongoing CRTS sky survey as a testbed: Bayesian Network, [dm,dt] histograms, Decision Trees, Neural Networks, Symbolic Regression. In this work we focus on the lightcurve based classification using an hierarchical approach where some astrophysically motivated major features are used to separate different groups of classes. Proceeding down the classification hierarchy every node uses those classifiers that are demonstrated to work best for that particular task.

  11. Nonlinear Analysis of Pulsating White Dwarf Lightcurves

    NASA Astrophysics Data System (ADS)

    Provencal, J. L.; Montgomery, M. H.; Shipman, H.; WET TEam

    2015-06-01

    Convection remains one of the largest sources of theoretical uncertainty in our understanding of stellar physics. For example, Bergeron (1995) show that basic parameters such as flux, line profiles, energy distribution, color indices, and equivalent widths are extremely sensitive to the assumed convective parameterization. This is compelling, since we use our knowledge of these basic parameters to calibrate white dwarf cooling sequences, provide detailed estimates for the ages of individual white dwarfs, and determine the age of the Galactic disk. The Whole Earth Telescope (WET) is engaged in a long term project to empirically calibrate the physical properties of convection in pulsating white dwarfs by combining asteroseismology and analysis of nonlinear light curves. Nonsinusoidal distortions, in the form of narrow peaks and wider valleys, are observed in many pulsating white dwarf light curves. These are a reflection of the local depth of the convection zone, a value which varies during a pulsation cycle. Applying asteroseismology and convective light curve fitting to a wide sample of pulsating white dwarfs provides an empirical map of how the convective response time (the convection zone “depth”) varies as a function of effective temperature, and this can be compared with theoretical models, both MLT and hydrodynamic. This project has resulted in a large database of white dwarf lightcurves and pulsation frequencies. We present current results for DA and DB pulsators, and provide a few examples of interesting pulsation behavior seen along the way.

  12. Lightcurves of the Karin family asteroids

    NASA Astrophysics Data System (ADS)

    Yoshida, Fumi; Ito, Takashi; Dermawan, Budi; Nakamura, Tsuko; Takahashi, Shigeru; Ibrahimov, Mansur A.; Malhotra, Renu; Ip, Wing-Huen; Chen, Wen-Ping; Sawabe, Yu; Haji, Masashige; Saito, Ryoko; Hirai, Masanori

    2016-05-01

    The Karin family is a young asteroid family formed by an asteroid breakup 5.8 Myr ago. Since the members of this family probably have not experienced significant orbital or collisional evolution yet, it is possible that they still preserve properties of the original family-forming event in terms of their spin state. We carried out a series of photometric observations of the Karin family asteroids, and here we report on the analysis of the lightcurves including the rotation period of eleven members. The mean rotation rate of the Karin family members turned out to be much lower than those of near-Earth asteroids or small main belt asteroids (diameter D < 12 km), and even lower than that of large main belt asteroids (D > 130 km). We investigated a correlation between the peak-to-trough variation and the rotation period of the eleven Karin family asteroids, and found a possible trend that elongated members have lower spin rates, and less elongated members have higher spin rates. However, this trend has to be confirmed by another series of future observations.

  13. The Evolving Photometric Lightcurve of Comet 1P/Halley’s Coma during the 1985/86 Apparition

    NASA Astrophysics Data System (ADS)

    Schleicher, David G.; Bair, Allison N.; Sackey, Siobhan; Alciatore Stinnett, Lorinda A.; Williams, Rebecca M. E.; Smith-Konter, Bridget R.

    2015-09-01

    We present new analyses of the photometric lightcurve of Comet 1P/Halley during its 1985/86 apparition. As part of a worldwide campaign coordinated by the International Halley Watch (IHW), narrowband photometry using standardized filters was obtained with telescopes at 18 observatories. Following submissions to and basic reductions by the Photometry and Polarimetry Network of the IHW, we further reduced the resulting fluxes to production rates and, following temporal binning, created composite lightcurves for each species. These were used to measure how the apparent rotational period (˜7.35 days), along with its shape, evolved with time during the apparition. The lightcurve shape systematically varied from double-peaked to triple-peaked and back again every 8-9 weeks, due to Halley's non-principal axis (complex) rotation and the associated component periods. Unexpectedly, we found that a phase shift of one-half cycle also took place during this interval, and therefore the actual beat frequency between the component periods is twice this interval or 16-18 weeks. Preliminary modeling suggests that a single source might produce the entire post-perihelion lightcurve variability and associated evolution, and an additional source is probably also required to explain additional features before perihelion. The detailed evolution of the apparent period varied in a nonsmooth manner between 7.2 and 7.6 days, likely due to a combination of synodic effects and the interaction of solar illumination with isolated source regions on a body in complex rotation. The need to simultaneously reproduce each of these characteristics will provide very strong additional constraints on Halley's component periods associated with its complex rotation. To assist in these and future analyses, we created a synthetic lightcurve based directly on the measured data and how the lightcurve shape evolved week to week. This synthetic lightcurve was successfully compared to other data sets of Halley and

  14. Impromptu Speaking and Interpretation Studies: A Preliminary Study

    ERIC Educational Resources Information Center

    Heinz, Michael

    2013-01-01

    The purpose of this preliminary study was to look at forensics-based competition events and determine what, if any, impact they could have on the language learning and public speaking skills of interpreters in training. This paper details the nature of the impromptu and extemporaneous speaking events in forensics competitions and introduces a…

  15. Analysis of Gaspra lightcurves using Galileo shape and photometric models

    NASA Technical Reports Server (NTRS)

    Simonelli, Damon P.; Veverka, J.; Thomas, P. C.; Helfenstein, P.; Belton, M. J. S.

    1995-01-01

    Galileo-based models for the shape of 951 Gaspra and the global-average photometric behavior of its surface have been used to model a representative subset of the asteroid's telescopic lightcurves. Fitting the synthetic lightcurves to the observed timing of lightcurve extrema, and knowing the orientation of Gaspra's axes at the time of the Galileo flyby, leads to a sidereal rotation period for the asteroid of 7.042024 +/- 0.000020 hr, a slight change from the period reported by Magnusson et al. (1992). Initially, the shapes, amplitudes, and absolute photometry of the synthetic and observed lightcurves agree with each other to within 0.05-0.1 mag. Small modifications to the Gaspra shape model on sides of the asteroid poorly imaged by Galileo (changes of 700 m or less in the southern hemisphere at longitudes 90 deg-270 deg W) reduce the typical discrepancies to approximately 0.05 mag in lightcurve shape and less than 0.03 mag in absolute photometry. The result demonstrates that Earth-based lightcurves can be used to refine the shape of a spacecraft-imaged irregular object in areas that are poorly constrained by the spacecraft observations. The consistency and phase-angle dependence of the Galileo-based model for Gaspra photometry, supports the accuracy of the absolute calibration of the Galileo SSI camera, and confirms the Earth-based determination of the V-filter geometric albedo of the asteroid (0.22 +/- 0.03; Tholen et al., submitted for publication). Remaining discrepancies between the synthetic and observed lightcurves show no indication of systematic latitudinal variations in albedo and also cannot be explained entirely by isolated albedo spots. These discrepancies are most likely caused by (1) small, remaining, hard-to-constrain errors in the Gaspra shape model and/or (2) moderate variations in macroscopic roughness across the asteroid's surface, in particular making longitudes 130 deg to 300 deg W moderately rougher than the opposite hemisphere.

  16. Preliminary design study for an atomospheric science facility

    NASA Technical Reports Server (NTRS)

    Hutchison, R.

    1972-01-01

    The activities and results of the Atmospheric Science Facility preliminary design study are reported. The objectives of the study were to define the scientific goals, to determine the range of experiment types, and to develop the preliminary instrument design requirements for a reusable, general purpose, optical research facility for investigating the earth's atmosphere from a space shuttle orbital vehicle.

  17. Preliminary simulation study of a coincidence Avalanche Pixel Sensor

    NASA Astrophysics Data System (ADS)

    Vignetti, M. M.; Calmon, F.; Cellier, R.; Pittet, P.; Quiquerez, L.; Savoy-Navarro, A.

    2015-06-01

    In this paper a preliminary study of coincidence Avalanche Pixel Sensors (APiX) for High Energy Physics (HEP) applications is presented. In this preliminary work, some PEB prevention techniques found in literature have been studied by TCAD simulations adopting 2D Cylindrical geometrical models and 130nm CMOS process technological data.

  18. Long-term lightcurves from combined unified very high energy γ-ray data

    NASA Astrophysics Data System (ADS)

    Tluczykont, M.; Bernardini, E.; Satalecka, K.; Clavero, R.; Shayduk, M.; Kalekin, O.

    2010-12-01

    Context. Very high-energy (VHE, E > 100 GeV) γ-ray data are a valuable input for multi-wavelength and multi-messenger (e.g. combination with neutrino data) studies. Aims: We aim at the conservation and homogenization of historical, current, and future VHE γ-ray-data on active galactic nuclei (AGN). Methods: We have collected lightcurve data taken by major VHE experiments since 1991 and combined them into long-term lightcurves for several AGN, and now provide our collected datasets for further use. Due to the lack of common data formats in VHE γ-ray astronomy, we have defined relevant datafields to be stored in standard data formats. The time variability of the combined VHE lightcurve data was investigated, and correlation with archival X-ray data collected by RXTE/ASM tested. Results: The combination of data on the prominent blazar Mrk 421 from different experiments yields a lightcurve spanning more than a decade. From this combined dataset we derive an integral baseline flux from Mrk 421 that must be lower than 33% of the Crab Nebula flux above 1 TeV. The analysis of the time variability yields log-normal flux variations in the VHE-data on Mrk 421. Conclusions: Existing VHE data contain valuable information concerning the variability of AGN and can be an important ingredient for multi-wavelength or multi-messenger studies. In the future, upcoming and planned experiments will provide more data from many transient objects, and the interaction of VHE astronomy with classical astronomy will intensify. In this context a unified and exchangeable data format will become increasingly important. Our data collection is available at the url: http://nuastro-zeuthen.desy.de/magic_experiment/projects/light_curve_archive/index_eng.html

  19. Minimizing follow-up for space-based transit surveys using full lightcurve analysis

    NASA Astrophysics Data System (ADS)

    Nefs, S. V.; Snellen, I. A. G.; de Mooij, E. J. W.

    2012-07-01

    CoRoT team, for which the lightcurves alone rule out blended light at 14% (2σ) and 31% (2σ). One system possesses a M-dwarf secondary, one a candidate Neptune. Conclusions: We show that in the first CoRoT field, IRa01, 85% of the planet candidates can be rejected from the lightcurves alone, if a cut in impact parameter of b < 0.85 is applied, at the cost of a <15% loss in planet yield. We propose to use this method on the Kepler database to study the fraction of real planets and to potentially increase the efficiency of follow-up. Appendix A is available in electronic form at http://www.aanda.org

  20. Figure of the double Asteroid 90 Antiope from adaptive optics and lightcurve observations

    NASA Astrophysics Data System (ADS)

    Descamps, P.; Marchis, F.; Michalowski, T.; Vachier, F.; Colas, F.; Berthier, J.; Assafin, M.; Dunckel, P. B.; Polinska, M.; Pych, W.; Hestroffer, D.; Miller, K. P. M.; Vieira-Martins, R.; Birlan, M.; Teng-Chuen-Yu, J.-P.; Peyrot, A.; Payet, B.; Dorseuil, J.; Léonie, Y.; Dijoux, T.

    2007-04-01

    A long-term adaptive optics (AO) campaign of observing the double Asteroid (90) Antiope has been carried out in 2003-2005 using 8-10-m class telescopes, allowing prediction of the circumstances of mutual events occurring during the July 2005 opposition [Marchis, F., Descamps, P., Hestroffer, D., Berthier, J., de Pater, I., 2004. Bull. Am. Astron. Soc. 36, 1180]. This is the first opportunity to use complementary lightcurve and AO observations to extensively study the (90) Antiope system, an interesting visualized binary doublet system located in the main belt. The orbital parameters derived from the AO observations have served as input quantities for the derivation of a whole set of other physical parameters (namely shapes, surface scattering, bulk density, and internal properties) from analysis of collected lightcurves. To completely model the observed lightcurves, we employed Roche figures to construct an overall shape solution. The combination of these complementary observations has enabled us to derive a reliable physical and orbital solution for the system. Our model is consistent with a system of slightly non-spherical components, having a size ratio of 0.95 (with R=42.9±0.5 km, separation =171±1 km), and exhibiting equilibrium figures for homogeneous rotating bodies. A comparison with grazing occultation event lightcurves suggests that the real shapes of the components do not depart from Roche equilibrium figures by more than 10%. The J2000 ecliptic coordinates of the pole of the system are λ=200°±2° and α=38°±2°. The orbital period was refined to P=16.5051±0.0001 h, and the density is found to be slightly lower than previous determinations, with a value of 1.25±0.05 g/cm, leading to a significant macro-porosity of 30%. Possible scenarios for the origin of the system are also discussed.

  1. Spin vectors in the Koronis family: comprehensive results from two independent analyses of 213 rotation lightcurves

    NASA Astrophysics Data System (ADS)

    Slivan, Stephen M.; Binzel, Richard P.; Crespo da Silva, Lucy D.; Kaasalainen, Mikko; Lyndaker, Mariah M.; Krčo, Marko

    2003-04-01

    Observations of Koronis asteroid family members (158) Koronis, (277) Elvira, (311) Claudia, (321) Florentina, and (720) Bohlinia made during the period 1998-2001 yielded 61 new individual rotation lightcurves to augment previous surveys (R.P. Binzel, 1987, Icarus 72, 135-208; S.M. Slivan, R.P. Binzel, 1996, Icarus 124, 452-470) and allow determination of the senses of rotation and spin vector orientations for these objects. Spin vector reductions were performed on these five objects and also on family members (167) Urda, (208) Lacrimosa, (534) Nassovia, and (1223) Neckar using both a combination of amplitude-magnitude and epoch methods and a convex inversion method. A total of 213 individual lightcurves were analyzed to determine sidereal rotation periods, pole solutions and obliquities, associated photometric parameters, and model shapes for each object. We checked our methods and results using the (243) Ida Master Dataset of lightcurves (R. P. Binzel et al., 1993, Icarus 105, 310-325) and found that the true pole determined from the Galileo fly by of this irregularly shaped member of the Koronis family falls just at the edge of the estimated uncertainty of our own solution. Our findings for the spin vector distribution of 10 members within the Koronis family represent the first systematic study of spin states within a well-established Hirayama family, and provide observational constraints for models of the physics of family formation and spin vector evolution in the main belt.

  2. Lightcurves and the axis of rotation of 433 Eros

    NASA Technical Reports Server (NTRS)

    Dunlap, J. L.

    1976-01-01

    Ten lightcurves and UBV photometry of 433 Eros were obtained between August 1972 and May 1975. The absolute magnitude of the lightcurve maximum is 10.75 and the phase coefficient is 0.025 mag/deg. There may be a small difference in B-V color between the northern and southern hemispheres. The pole of the axis of rotation is directed toward 16 deg, ecliptic longitude and 12 deg ecliptic latitude, respectively, and the rotation is direct with a sidereal period of 5 hr 16 min 13.4 sec. The dimensions derived from the polarimetric albedo and the lightcurve amplitudes are 12 km by 12 km by 31 km for a smooth cylinder with hemispherical ends.

  3. First photometric lightcurve observations from the Evelyn L. Egan Observatory

    NASA Astrophysics Data System (ADS)

    Fauerbach, Michael; Bennett, Thomas

    2005-06-01

    The first photometric lightcurve results from the Evelyn L. Egan Observatory [MPC Code H72] are reported. Despite a wildfire on campus and four land falling hurricanes, we were able to obtain detailed lightcurve measurements over a period of several nights for two main-belt asteroids: 287 Nephthys and 479 Caprera. The following synodic periods and amplitudes were determined: 287 Nephthys: 7.6065h±0.0002h with an amplitude of 0.20m; 479 Caprera: 9.4250h±0.0003h with an amplitude of 0.11m.

  4. Photometry and Lightcurve Analysis of 7 Main-Belt Asteroids

    NASA Astrophysics Data System (ADS)

    Violante, Renata; Leake, M. A.

    2013-01-01

    We report the synodic periods and lightcurves for three main-belt asteroids and provide lightcurves for four other main-belt asteroids. 676 Melitta has a period of 8.35 ± 0.05 hours, with an amplitude of 0.056 ± 0.026 magnitude; 688 Melanie has a period of 16.10 ± 0.05 hours, and an amplitude of 0.091 ± 0.019 magnitude; 1677 Tycho Brahe has a period of 3.89 ± 0.06 hours, and an amplitude of 0.564 ± 0.011 magnitude.

  5. Photometry and Lightcurve Analysis of 7 Main-Belt Asteroids

    NASA Astrophysics Data System (ADS)

    Violante, R.; Leake, M. A.

    2012-12-01

    We report the synodic periods and lightcurves for three main-belt asteroids and provide lightcurves for four other main-belt asteroids. 676 Melitta has a period of 8.35 ± 0.05 hours, with an amplitude of 0.056 ± 0.026 magnitude; 688 Melanie has a period of 16.10 ± 0.05 hours, and an amplitude of 0.091 ± 0.019 magnitude; 1677 Tycho Brahe has a period of 3.89 ± 0.06 hours, and an amplitude of 0.564 ± 0.011 magnitude.

  6. MALLARD REPRODUCTIVE TESTING IN A POND ENVIRONMENT: A PRELIMINARY STUDY

    EPA Science Inventory

    A 2-year preliminary study was conducted on mallard ducks to determine the feasibility of using outdoor pond enclosures for reproductive studies and to evaluate the effects of the insecticide chlorpyrifos on mallard reproduction. No significant reproductive effects were observed ...

  7. Lightcurve Analysis of Asteroids from Blue Mountains Observatory in 2014

    NASA Astrophysics Data System (ADS)

    Oey, Julian

    2016-01-01

    Photometric observations of a number of asteroids were done from Blue Mountains Observatory in 2014. The observations were made in support of the binary asteroid and asteroid pairs campaigns by Petr Pravec, and to obtain new data at favorable apparitions for asteroids with poorly defined lightcurves.

  8. Steven J. Ostro: Pioneer in Asteroid Lightcurve Inversion

    NASA Astrophysics Data System (ADS)

    Harris, Alan W.

    2009-09-01

    In 1906, Henry Norris Russell wrote a landmark paper (Astrophys. J. 24, 1-18, 1906) that set the field of lightcurve inversion back by more than three quarters of a century, until Steve Ostro and Robert Connolly published a paper on "convex profile inversion” (Icarus 57, 443-463, 1984). Russell's stifling contribution was innocent enough, and entirely correct: he showed that with "two cans of paint", one can decorate any arbitrarily shaped body in an infinite number of ways to yield any particular lightcurve, even, for example, a cigar shape that is brightest viewed end-on. This sufficed to discourage serious mathematical attack on the problem until Ostro & Connolly's landmark paper of 1984. They showed that if you have only "one can of paint", that is, in the absence of albedo variegation, the problem is tractable and one can make remarkable progress in lightcurve inversion to obtain shapes, or at least the "convex profile” of the real shape. As we now know, nature appears to have only one can of paint (per asteroid), that is, asteroids seem to paint themselves grey so that the uniform reflectivity assumption is quite excellent. Both radar and optical lightcurve inversion techniques are now quite mature, thanks to Steve's pioneering insights.

  9. Lightcurves and Rotational Periods of Three Main-belt Asteroids

    NASA Astrophysics Data System (ADS)

    Cantu, Sarah A.; Kozdon, Janus; Montgomery, Kent; Lyons, Vanessa

    2016-07-01

    Lightcurves were measured for three asteroids: 800 Kressmania, 3494 Purple Mountain, and (25891) 2000 WK9. Respectively, the rotational periods determined were 4.465 ± 0.002 hours, 2.929 ± 0.001 hours, and 4.1375 ± 0.0015 hours.

  10. Lightcurve Analysis of 1489 Attila and 1696 Nurmela

    NASA Astrophysics Data System (ADS)

    Stephens, Robert D.; Malcolm, Glenn

    2007-09-01

    Observations of 1489 Attila and 1696 Nurmela were made in early 2007 with period and lightcurve amplitude results of 11.28 ± 0.01 hours, 0.42 mag. and 3.1587 ± 0.0001 hours, 0.33 mag., respectively.

  11. Reconstruction of stellar surface features via matrix lightcurve inversion

    NASA Astrophysics Data System (ADS)

    Harmon, Robert Olin, II

    1999-11-01

    Matrix Lightcurve Inversion (MLI) is a technique for deducing the surface brightness distributions of rapidly rotating spotted stars or the surface albedo distributions of planets (in particular Pluto) from their rotational lightcurves. When applied to the stellar problem it has the significant advantage over ``spot models'' that it makes no a priori assumptions about the number of spots on the stellar surface or their shapes. We demonstrate the viability of the method for determining the shapes and locations of dark spots on stellar surfaces and explore its potential and its limitations by presenting the results of inversions of synthetic lightcurves corresponding to model stars with known surface features. We show that when lightcurves acquired through different photometric filters are simultaneously inverted, significant improvements can be achieved compared to when only a single filter is used. In particular, it becomes possible to more reliably deduce the presence of high-latitude activity, presenting the possibility of corroborating Doppler images which imply high-latitude spots. We apply MLI to the inversion of V and B lightcurves of the RS CVn binary II Pegasi acquired from September 1995 to January 1996, and show that two major spots or active regions were present. Initially they were separated by almost 180° in longitude, but over time the larger spot drifted forward in longitude in the direction of rotation relative to the orbital ephemeris while the smaller spot remained nearly stationary. This may be due to differential rotation. There is evidence that the larger spot was at a higher latitude than the smaller spot, which would imply that the differential rotation has the opposite sense of that on the Sun.

  12. Preliminary design studies of an advanced general aviation aircraft

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Preliminary design studies are presented for an advanced general aviation aircraft. Advanced guidance and display concepts, laminar flow, smart structures, fuselage and wing structural design and manufacturing, and preliminary configuration design are discussed. This project was conducted as a graduate level design class under the auspices of the KU/NASA/USRA Advanced Design Program in Aeronautics. The results obtained during the fall semester of 1990 (Phase 1) and the spring semester of 1991 (Phase 2) are presented.

  13. Preliminary design study. Shuttle modular scanning spectroradiometer

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Fundamental concepts on which to base a detailed design for a Shuttle Modular Scanning Spectroradiometer were developed, and a preliminary design is presented. The recommended design features modularity and flexibility. It includes a 75-cm f/1.7-telescope assembly in an all-reflective Schmidt configuration, a solid state scan system (pushbroom) with high resolution over a 15 deg field of view, and ten detector channels covering the spectral range from 0.45 to 12.5 micrometers. It uses charge transfer device techniques to accommodate a large number of detector elements for earth observation measurements. Methods for in-flight radiometric calibration, for image motion compensation, and for data processing are described. Recommendations for ground support equipment are included, and interfaces with the shuttle orbiter vehicle are illustrated.

  14. Lightcurve Photometry and Search for Cometary Activity of NEA 2007 PU11

    NASA Astrophysics Data System (ADS)

    Carbognani, Albino; Pravec, Petr; Krugly, Yurij N.; Pray, Donald P.; Gajdos, Stefan; Gaftonyuk, Ninel M.; Slyusarev, Ivan

    2008-06-01

    The lightcurve period and amplitude, color indices, and absolute magnitude from a collaborative study are reported for Amor asteroid 2007 PU11: P = 56.8 ± 0.1 h; A = 0.98 ± 0.03 mag; B-V = 0.85 ± 0.05; V-R = 0.44 ± 0.03; R-I = 0.34 ± 0.03; H = 16.39 ± 0.12. A search for a cometary activity was made with negative results.

  15. Asteroid lightcurve analysis at the NAO Rozhen: 2014 March - December

    NASA Astrophysics Data System (ADS)

    Apostolovska, Gordana; Kostov, Andon; Donchev, Zahary; Kuzmanovska, Olgica

    2016-03-01

    Lightcurve analysis of five main belt asteroids 339 Dorothea, 549 Jessonda, 2445 Blazhko, 4528 Berg and 5317 Vero-lacqua observed at Bulgarian National Astronomical Observatory (NAO) Rozhen since March to December 2014 is presented. The choice of the asteroids was made according to their visibility in allocated observing time on the 50/70cm Schmidt and 60cm Cassegrain telescope and in the frame of our long term photometry program for determining the shape and poles of asteroids.

  16. The Photometric lightcurve of Comet 1P/Halley

    NASA Astrophysics Data System (ADS)

    Bair, Allison N.; Schleicher, David G.

    2014-11-01

    Comet 1P/Halley is considered an important object for a number of reasons. Not only is it the first-identified and brightest periodic comet, being the only periodic comet visible to the naked eye at every apparition, but in 1986 Halley became the first comet to be imaged by fly-by spacecraft. The NASA-funded International Halley Watch (IHW) directly supported the spacecraft by providing narrowband filters for groundbased photometric observations, and until the arrival of Hale-Bopp (1995 O1), Halley was the subject of the largest groundbased observational campaign in history. Following considerable controversy regarding its rotation period, it was eventually determined to be in complex rotation -- the first comet to be so identified. While the overall brightness variations of the coma repeated with a period of about 7.4 days, the detailed period and shape of the lightcurve constantly evolved. The determination of the specific characteristics of each of the two components of its non-principal axis rotational state has remained elusive.To resolve this situation we have now incorporated all of the narrowband photometry, taken by 21 telescopes from around the world and submitted to the IHW archive, to create the most complete homogeneous lightcurve possible. Using measurements of three gas species and the dust, the lightcurve was investigated and found to alternate between a double- and triple-peaked shape, with no single feature being present throughout the entire duration of our dataset (316 days). The apparent period as a function of time was extracted and seen to vary in a step-wise manner between 7.27 and 7.60 days. Taken together, these results were used to produce a synthetic lightcurve revealing Halley's behavior even when no data were available. Details of this and other results, to be used to constrain future detailed modeling, will be presented. This research is supported by NASA's Planetary Atmospheres Program.

  17. Lightcurve Analysis of Near-Earth Asteroid 2010 TN54

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Benishek, Vladimir; Ferrero, Andrea

    2014-01-01

    CCD photometry observations of the near-Earth asteroid (NEA) 2010 TN 54 indicate a period of either 6.14 h or 12.12 h, depending on whether a monomodal or bimodal lightcurve is adopted. The amplitude was only 0.07 ± 0.01 mag, which - along with the period being nearly commensurate with an Earth day - made finding a definitive solution difficult, despite being observed from locations in North America and Europe.

  18. Lightcurve Analysis Collaboration for 561 Ingwelde and 621 Werdandi

    NASA Astrophysics Data System (ADS)

    Strabla, Luca; Quadri, Ulisse; Girelli, Roberto; Pilcher, Frederick

    2012-07-01

    Lightcurves of 621 Werdandi and 561 Ingwelde were obtained by a collaboration between Bassano Bresciano Observatory and Organ Mesa Observatory. Thanks to this collaboration, it was possible to cover the full rotation cycle for both objects, both of which had periods close to half of an Earth day. For 561 Ingwelde we found P = 12.012 ± 0.001 h and for 621 Werdandi, P = 11.776 ± 0.001 h.

  19. TRANSIT LIGHTCURVES OF EXTRASOLAR PLANETS ORBITING RAPIDLY ROTATING STARS

    SciTech Connect

    Barnes, Jason W.

    2009-11-01

    Main-sequence stars earlier than spectral-type approxF6 or so are expected to rotate rapidly due to their radiative exteriors. This rapid rotation leads to an oblate stellar figure. It also induces the photosphere to be hotter (by up to several thousand kelvin) at the pole than at the equator as a result of a process called gravity darkening that was first predicted by von Zeipel. Transits of extrasolar planets across such a non-uniform, oblate disk yield unusual and distinctive lightcurves that can be used to determine the relative alignment of the stellar rotation pole and the planet orbit normal. This spin-orbit alignment can be used to constrain models of planet formation and evolution. Orderly planet formation and migration within a disk that is coplanar with the stellar equator will result in spin-orbit alignment. More violent planet-planet scattering events should yield spin-orbit misaligned planets. Rossiter-McLaughlin measurements of transits of lower-mass stars show that some planets are spin-orbit aligned, and some are not. Since Rossiter-McLaughlin measurements are difficult around rapid rotators, lightcurve photometry may be the best way to determine the spin-orbit alignment of planets around massive stars. The Kepler mission will monitor approx10{sup 4} of these stars within its sample. The lightcurves of any detected planets will allow us to probe the planet formation process around high-mass stars for the first time.

  20. Spin Axis Distribution of the Hungaria Asteroids via Lightcurve Inversion

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.

    2015-05-01

    In the past decade or so, the influence on small asteroids of the YORP (Yarkovsky-O'Keefe-Radzievskii-Paddack) effect, which is the asymmetric thermal emission of received sunlight, has been firmly established. The two strongest pieces of evidence are the nearly flat distribution of rotation rates of small asteroids and the distribution of spin axes (poles). YORP theory says that the spin axes, barring outside influences, are eventually forced to low obliquities, i.e., the poles are located near the north or south ecliptic poles. This would seem natural for objects with low orbital inclinations. However, for objects with high orbital inclinations, such as the Hungarias, there are some questions if this would still be the case. The authors and other observers have accumulated dense lightcurves of the Hungaria asteroids for more than a decade. The combination of these dense lightcurves and sparse data from asteroid search surveys has allowed using lightcurve inversion techniques to determine the spin axes for almost 75 Hungaria asteroids. The results confirm earlier works that show an anisotropic distribution of spin axes that favors the ecliptic poles and, as predicted for the Hungarias, a preponderance of retrograde rotators.

  1. Applying for Your Own Job: A Preliminary Study

    ERIC Educational Resources Information Center

    Boyd, Elizabeth Reid

    2008-01-01

    This study undertook a small preliminary investigation of the contemporary employment practice of "applying for your own job". There has not yet been a specific study into the effect upon individuals and organisations of the practice of existing employees being required to apply for the same or a similar position in a competitive application…

  2. Spirituality and the Events of September 11: A Preliminary Study

    ERIC Educational Resources Information Center

    Briggs, Michele Kielty; Apple, Kevin J.; Aydlett, Ann E.

    2004-01-01

    Personal crises have been associated with spiritual growth. Sparked by the global response to the crisis of September 11, 2001, this study examined the relationship of spirituality and the September 11 tragedy using a sample of convenience from a college student population. This preliminary study used an experimental design to examine various…

  3. A Preliminary Study of Career Education in Middle School

    ERIC Educational Resources Information Center

    Ting, S. R.; Leung, Y. F.; Stewart, K.; Smith, A. C.; Roberts, G. L.; Dees, S.

    2012-01-01

    This article reports a preliminary study on the Geosciences in Middle School, which was a career education program in the Southeastern U.S focusing on science based on Super's (1990) theory. The students (n = 80) were found to improve their interests in studying science, increase science knowledge, skills and awareness and highly satisfied with…

  4. Support Observations For New Horizons: Pluto's Solar Phase Curve As Measured By The Cassini Spacecraft And A New Ground-based Optical Lightcurve.

    NASA Astrophysics Data System (ADS)

    Hicks, Michael D.; Buratti, B. J.; Gillam, S. D.; Young, J. W.; Somers, J. F.

    2008-09-01

    Sequence planning for the New Horizons flyby of Pluto on 2015 July 14 requires an accurate estimation of the surface scattering properties at high solar phase angles ( 90 deg). As seen from the Earth, however, the solar phase angle of Pluto never exceeds 1.9 deg. We are fortunate to have been afforded the opportunity to begin to regularly integrate Cassini-ISS imaging of Pluto into Cassini Optical Navigation (Op-Nav) sequencing. We report on space-based photometric observations of Pluto on the following dates, with the solar phase angles listed in parenthesis: 2007 March 31 (11.94 deg), 2008 March 01 (13.63 deg), 2008 July 09 (14.21 deg). Additional Cassini Op-Nav imaging of Pluto was scheduled for 2007 September 12 and 2007 October 05 but were lost due to spacecraft safing and a data overrun event, respectively. Reduction of the Op-Nav imaging of Pluto is made complex by the extremely dense stellar background: near-simultaneous observations of the Pluto fields at the JPL Table Mountain Observatory (TMO) 0.6-meter telescope allows for proper subtraction of faint background sources. Combined data from Cassini-ISS and TMO data gives a preliminary phase coefficient in the R band of Beta = 0.06 +/- 0.02 mag per deg. We shall present results that incorporate a more detailed analysis. In order to constrain potential volatile transport on the surface of Pluto due to changing solar illumination geometry and heliocentric distance, we have recently measured (2007 October-2008 March) a Bessel R-band rotational lightcurve of the planet at TMO which exhibits a lightcurve amplitude of 0.15 +/- 0.02 mag. We shall compare our new lightcurve to historical Pluto lightcurve measurements and to the expected secular lightcurve changes based on the HST albedo map.

  5. Some Suggestions for Writing up Asteroid Lightcurve Observations for Publication

    NASA Astrophysics Data System (ADS)

    Harris, A. W.

    2005-05-01

    Over the years I have spent many hours re-constructing photometric observa- tions from published works that would have been much easier if the authors had provided full and accurate details of the observations being reported. In this paper I will present the essential elements of reporting that render the photometric observations reported most useful and convenient for future analysis. The underlying principle to keep in mind is that the composite lightcurve you construct may not be right, or may not serve the purposes of some future research project, such that someone may need to recover your original observations as a time series rather than just the composite lightcurve presented. Other ancillary information should be provided to assist in using the data in combination with observations at other times, e.g. the aspect data (sky position, phase angle, light time correction if applied, etc.), and the color band and magnitude scale information. In a composite lightcurve figure, vertical (magnitude) offsets applied night to night should be indicated (in the figure or in a data table), days of obser- vation should be plotted with different symbols and identified, and if cov- erage on a single night exceeds the rotation period such that the time series is "wrapped", it should be possible to determine the actual time of obser- vation of each datum. In constructing a composite, it is essential that the period used to fold the data be the exact value stated so that the exact observation times can be reconstructed from the composite. Ideally, all data presented should also be made available in electronic form in a public archive (this will be a topic of considerable discussion at the meeting). Another essential feature is to reference and critically evaluate any pre- vious lightcurves of an object that can be found in the literature. In addi- tion to checking for consistency of results and possibly incorporating other observations in the analysis, the task of

  6. Observations of Io's Active Volcanoes from IRTF: Imaging and Occultation Lightcurves

    NASA Astrophysics Data System (ADS)

    Rathbun, J. A.; Spencer, J. R.

    2014-12-01

    We have been observing Ionian volcanism from NASA's Infrared Telescope Facility (IRTF) for more than two decades. The frequency of our observations increases dramatically when spacecraft are observing Io in order to complement the data returned by the spacecraft. The Japanese Space Agency's (JAXA) Hisaki (Sprint-A) mission recently observd the Jupiter system from earth orbit, monitoring the Io Plasma Torus and Jovian aurora. In order to investigate the possible influence of Io volcanism on the torus, we observed Io's volcanoes from the IRTF in Hawaii between September 2013 and May 2014. We imaged Io at 2.2, 3.5, and 4.8 microns in eclipse and reflected sunlight. We also observed Io during occultation by Jupiter, which allows us to locate and characterize individual volcanic eruptions, with greater spatial accuracy, on the Jupiter-facing hemisphere. The 2013 3.5 micron images of a sunlit Io showed no obvious bright volcanic features. However, further increases in spatial resolution is possible with shift-and-add processing of short exposure images. Preliminary occultation lightcurves from 2013 show moderate levels of activity at Kaneheliki/Janus and Loki, the two volcanic centers most often observed in occultation lightcurves. Loki was much brighter in 2013 than during the New Horizons flyby in 2007, but not as bright as during the Galileo era (see figure). From February 2014 through May 2014, due to a planned upgrade on the SPEX instrument and an unplanned required repair on the NSFCam2 instrument (both of which we have used previously), we exclusively used the CSHELL instrument as an imager. Unfortunately, CSHELL was not designed for imaging and has limited spatial resolution and photometric precision, complicating image analysis.

  7. Preliminary design studies of an advanced general aviation aircraft

    NASA Technical Reports Server (NTRS)

    Barrett, Ron; Demoss, Shane; Dirkzwager, AB; Evans, Darryl; Gomer, Charles; Keiter, Jerry; Knipp, Darren; Seier, Glen; Smith, Steve; Wenninger, ED

    1991-01-01

    The preliminary design results are presented of the advanced aircraft design project. The goal was to take a revolutionary look into the design of a general aviation aircraft. Phase 1 of the project included the preliminary design of two configurations, a pusher, and a tractor. Phase 2 included the selection of only one configuration for further study. The pusher configuration was selected on the basis of performance characteristics, cabin noise, natural laminar flow, and system layouts. The design was then iterated to achieve higher levels of performance.

  8. Twenty-one Asteroid Lightcurves at Group Observadores de Asteroides (OBAS): Late 2015 to Early 2016

    NASA Astrophysics Data System (ADS)

    Aznar Macias, Amadeo; Carreno Garcerain, Alfonso; Arce Masego, Enrique; Brines Rodriguez, Pedro; Lozano de Haro, Juan; Fornas Silva, Alvaro; Fornas Silva, Gonzalo; Mas Martinez, Vicente; Rodrigo Chiner, Onofre; Herrero Porta, David

    2016-07-01

    We report on the photometric analysis result of 21 mainbelt asteroids (MBA) done by Observadores de Asteroides (OBAS). This work is part of the Minor Planet Photometric Database task initiated by a group of Spanish amateur astronomers. We have managed to obtain a number of accurate and complete lightcurves as well as additional incomplete lightcurves to help analysis at future oppositions. This is a compilation of lightcurves obtained during last quarter of 2015 and first quarter of 2016.

  9. Decreasing Public Smoking among Youth: A Preliminary Study

    ERIC Educational Resources Information Center

    Jason, Leonard A.; Pokorny, Steven B.; Turner, Paul L.; Freeland, Margaret; Corbin, Sara; Driscoll, Mark

    2005-01-01

    This brief paper reports the results of two observational studies examining the impact of fines for youth tobacco possession on public smoking among youth. Preliminary findings are presented that suggest that when police issued warnings and tickets to reduce underage youth possession of tobacco, in both towns the number of youth smoking in public…

  10. PTSD and Impaired Eye Expression Recognition: A Preliminary Study

    ERIC Educational Resources Information Center

    Schmidt, Jakob Zeuthen; Zachariae, Robert

    2009-01-01

    This preliminary study examined whether posttraumatic stress disorder (PTSD) was related to difficulties in identifying the mental states of others in a group of refugees. Sixteen Bosnian refugees, referred to treatment in an outpatient treatment center for survivors of torture and war-related trauma in Denmark (CETT), were compared to 16 non-PTSD…

  11. Preliminary Design Study of a Hybrid Airship for Flight Research

    NASA Technical Reports Server (NTRS)

    Browning, R. G. E.

    1981-01-01

    The feasibility of using components from four small helicopters and an airship envelope as the basis for a quad-rotor research aircraft was studied. Preliminary investigations included a review of candidate hardware and various combinations of rotor craft/airship configurations. A selected vehicle was analyzed to assess its structural and performance characteristics.

  12. Student Matriculation: A Proposal to Study a Preliminary Model.

    ERIC Educational Resources Information Center

    Farland, Ronnald W.; Berg, Ernest

    Developed for the Board of Governors of the California Community Colleges (CCC) as part of a larger study of academic quality, this report presents a preliminary analysis of student matriculation, a guidance process which brings the student into an agreement with the college for the purpose of achieving the student's educational objectives through…

  13. Caregivers with Visual Impairments: A Preliminary Study

    ERIC Educational Resources Information Center

    Fuhr, Patti; Martinez, Bethany; Williams, Michael

    2008-01-01

    Persons who are elderly, visually impaired, and primary caregivers for ailing or disabled spouses or significant others are a unique population that has not been studied previously. By definition, "informal caregivers" are family members or friends who provide unpaid day-to-day assistance with activities of daily living and are familiar with the…

  14. Preliminary design study of a baseline MIUS

    NASA Technical Reports Server (NTRS)

    Wolfer, B. M.; Shields, V. E.; Rippey, J. O.; Roberts, H. L.; Wadle, R. C.; Wallin, S. P.; Gill, W. L.; White, E. H.; Monzingo, R.

    1977-01-01

    Results of a conceptual design study to establish a baseline design for a modular integrated utility system (MIUS) are presented. The system concept developed a basis for evaluating possible projects to demonstrate an MIUS. For the baseline study, climate conditions for the Washington, D.C., area were used. The baseline design is for a high density apartment complex of 496 dwelling units with a planned full occupancy of approximately 1200 residents. Environmental considerations and regulations for the MIUS installation are discussed. Detailed cost data for the baseline MIUS are given together with those for design and operating variations under climate conditions typified by Las Vegas, Nevada, Houston, Texas, and Minneapolis, Minnesota. In addition, results of an investigation of size variation effects, for 300 and 1000 unit apartment complexes, are presented. Only conceptual aspects of the design are discussed. Results regarding energy savings and costs are intended only as trend information and for use in relative comparisons. Alternate heating, ventilation, and air conditioning concepts are considered in the appendix.

  15. [Preliminary study of early sexual abuse].

    PubMed

    Gauthier, M C; Saucier, J F

    1991-08-01

    The long term effects of sexual abuse are often measured by measuring behaviours such as social adjustment, job stability and marriage. This study was conducted to add to these internal measures. Using a semi-prospective instrument adapted from G. Kelly's repertory grid, the adolescents' perceptions of themselves and significant others are measured. Three hundred and twelve female adolescents between the ages of 13 and 19 (average age = 16) participated in the study; 79 presented with non sexual behaviour disorders (delinquency, stealing, etc.), 56 presented with serious sexual behaviour disorders (prostitution, persistent sexual promiscuity) and 177 presented with no problems requiring psychosocial intervention. Various analyses (descriptive, multiple variance, regression analysis) showed that sexual abuse significantly affects many of the adolescents' perceptions. Sexually abused adolescents perceived their two real parents as less competent and their ideal mother and father as less protective than adolescents who had not been abused. In contrast, their perception of self and the ideal self was not affected by the sexual abuse, a finding which will spark discussion. PMID:1933745

  16. Preliminary systems design study assessment report

    SciTech Connect

    Mayberry, J.L.; Feizollahi, F.; Del Signore, J.C.

    1991-10-01

    The System Design Study (SDS), part of the Waste Technology Development Department of the Idaho National Engineering Laboratory (INEL), examined techniques available for the remediation of hazardous and transuranic waste stored at the Radioactive Waste Management Complex's Subsurface Disposal Area at the INEL. Using specific technologies, system concepts for treating the buried waste and the surrounding contaminated soil were evaluated. Evaluation included implementability, effectiveness, and cost. The SDS resulted in the development of technology requirements including demonstration, testing, and evaluation activities needed for implementing each concept. The SDS results are published in eight volumes. Volume I contains an executive summary. The SDS summary and analysis of results are presented in Volume II. Volumes III through VII contain descriptions of twelve system and four subsystem concepts. Volume VIII contains the appendixes.

  17. A Preliminary Immunologic Study of Urinary Proteins

    PubMed Central

    Barcelo, Raymond; Pollak, Victor E.

    1966-01-01

    The clearances of seven different proteins were measured by a quantitative immunodiffusion technique in 15 patients with proteinuria. All urines were also studied by immunoelectrophoresis. The renal histology was evaluated in each case, and no correlation was found between histologic changes and the urinary protein excretion. This observation was confirmed by both immunodiffusion and immunoelectrophoretic techniques. No specific urinary protein excretion pattern was found in six patients with systemic lupus erythematosus. High-molecular-weight proteins were rarely found in urine, even when the glomerular basement membrane was definitely thickened. Low-molecular-weight proteins were often observed, but their clearances were variable. The results do not support the suggestion that protein clearances are valuable diagnostic and prognostic tools in renal diseases. They also do not support the view that glomerular filtration is the sole factor responsible for the final patterns of urinary proteins; tubular reabsorption is probably another important factor. ImagesFig. 1Fig. 4Fig. 5 PMID:20328484

  18. Preliminary Photomicrographic Studies of Fuel Sprays

    NASA Technical Reports Server (NTRS)

    Lee, Dana W; Spencer, Robert C

    1932-01-01

    Photomicrographs were taken of fuel sprays injected into air at various densities for the purpose of studying the spray structure and the stages in the atomization of the fuel. The photomicrographs were taken at magnifying powers of 2.5, 3.25, and 10, using a spark discharge of very short duration for illumination. The results indicate that the theory advanced by Dr. R. A. Castleman, Jr., on the atomization of fuel in carburetors may also be applied to the atomization of fuel sprays of the solid-injection type. The fuel leaves the nozzle as a solid column, is ruffled and then torn into small, irregular ligaments by the action of the air. These ligaments are then quickly broken up into drops by the surface tension of the fuel. The photomicrographs also show that the dispersion of a fuel spray at a given distance from the nozzle increases with an increase in the jet velocity or an increase in the air density. The first portions of fuel sprays injected from an automatic injection valve into air at atmospheric density have a much greater dispersion than the later portions, but this difference decreases rapidly as the air density is increased.

  19. Spectral detection of thalassemia: a preliminary study

    PubMed Central

    2014-01-01

    Background Thalassemias (Thal) are forms of inherited autosomal recessive blood disorders arising out of mutations in the chromosomes 11 or 16. These disorders lead to poor oxygen delivery to blood vessels and consequent splenomegaly, bone deformities, and shorter life spans. The most common detection methods for Thal are complete blood count (CBC) followed by electrophoresis and molecular diagnosis methods, such as high-performance liquid chromatography (HPLC) and polymerase chain reaction (PCR) genotyping. These methods involve sophisticated instrumentations and are cumbersome and expensive. Results In this study an innovative spectral detection method, based on the fluorescence spectra of a set of biomolecules (tyrosine, tryptophan, nicotinamide adenine dinucleotide, and flavin adenine dinucleotide and porphyrins) found in blood components is presented. An algorithm based on the spectral features of such biomolecules of blood components of 20 Thal patients (10 female and 10 male) and 18 age adjusted normal controls (4 female and 14 male) demonstrate reasonable level of classification with sensitivity and specificity values exceeding 90%. Conclusion This new technique could be of significant value for Thal detection, diagnosis, and subsequent genetic counselling and could be adapted for use in small primary health centres. PMID:24679334

  20. Sleep education in college: a preliminary study.

    PubMed

    Tsai, Ling-Ling; Li, Sheng-Ping

    2004-12-01

    In this study we evaluated the effect of a two-credit (100 min./week) "Sleep Management" course on the sleep patterns of college students as the course progressed over an 18-wk. semester. Curricular activity included lectures, group discussions, and practice of self-evaluation of sleep. Instead of giving the students the whole list of sleep hygiene at the outset of the course, each concept of sleep hygiene was introduced and discussed under related lecture topics. A total of 241 students (131 men and 110 women) took the course and kept 7-day sleep logs three times. Concurrently, sleep-log data were collected from 65 students (32 men and 33 women) who were not taking the course. Both groups showed similar varieties of academic backgrounds and characteristics of sleep patterns at the beginning. Similarly, their sleep patterns, namely, rise time, nighttime awakenings, time asleep, time in bed, sleep efficiency, and rise time regularity, changed over the semester. Women in both groups had more nighttime awakenings. In contrast, sleep quality was progressively better for the group in the course but not for the control group. Only women in the course decreased their nap time in the second and third months. Thus, the course of "Sleep Management" only had a mild and limited effect on sleep patterns. The course content needs refinement to maximize influence on students' sleep patterns and habits, particularly, on reduction of insufficient sleep and daytime sleepiness which are the highest ranking sleep problems among college students. PMID:15648478

  1. Constraints on Pluto's Hazes from 2-Color Occultation Lightcurves

    NASA Astrophysics Data System (ADS)

    Hartig, Kara; Barry, T.; Carriazo, C. Y.; Cole, A.; Gault, D.; Giles, B.; Giles, D.; Hill, K. M.; Howell, R. R.; Hudson, G.; Loader, B.; Mackie, J. A.; Olkin, C. B.; Rannou, P.; Regester, J.; Resnick, A.; Rodgers, T.; Sicardy, B.; Skrutskie, M. F.; Verbiscer, A. J.; Wasserman, L. H.; Watson, C. R.; Young, E. F.; Young, L. A.; Buie, M. W.; Nelson, M.

    2015-11-01

    The controversial question of aerosols in Pluto's atmosphere first arose in 1988, when features in a Pluto occultation lightcurve were alternately attributed to haze opacity (Elliot et al. 1989) or a thermal inversion (Eshleman 1989). A stellar occultation by Pluto in 2002 was observed from several telescopes on Mauna Kea in wavelengths ranging from R- to K-bands (Elliot et al. 2003). This event provided compelling evidence for haze on Pluto, since the mid-event baseline levels were systematically higher at longer wavelengths (as expected if there were an opacity source that scattered more effectively at shorter wavelengths). However, subsequent occultations in 2007 and 2011 showed no significant differences between visible and IR lightcurves (Young et al. 2011).The question of haze on Pluto was definitively answered by direct imaging of forward-scattering aerosols by the New Horizons spacecraft on 14-JUL-2015. We report on results of a bright stellar occultation which we observed on 29-JUN-2015 in B- and H-bands from both grazing and central sites. As in 2007 and 2011, we see no evidence for wavelength-dependent extinction. We will present an analysis of haze parameters (particle sizes, number density profiles, and fractal aggregations), constraining models of haze distribution to those consistent with and to those ruled out by the occultation lightcurves and the New Horizons imaging.References:Elliot, J.L., et al., "Pluto's Atmosphere." Icarus 77, 148-170 (1989)Eshleman, V.R., "Pluto's Atmosphere: Models based on refraction, inversion, and vapor pressure equilibrium." Icarus 80 439-443 (1989)Elliot, J.L., et al., "The recent expansion of Pluto's atmosphere." Nature 424 165-168 (2003)Young, E.F., et al., "Search for Pluto's aerosols: simultaneous IR and visible stellar occultation observations." EPSC-DPS Joint Meeting 2011, held 2-7 October 2011 in Nantes, France (2011)

  2. Save the Lightcurves! An Update on the ALCDEF Project

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.

    2016-01-01

    The Asteroid Lightcurve Data Exchange Format (ALCDEF) project has been in development for more than five years. To date, almost 2.5 million time-series data points for more than 11400 asteroids have been submitted to the ALCDEF database hosted on the Minor Planet Center web site. These raw time-series observations have helped researchers produce hundreds of shape and spin axis models. The recent introduction of the S-ALCDEF (Simple-ALCDEF) page is hoped to encourage that even more data be submitted and so expedite and facilitate research efforts that depend on these type of data.

  3. Asteroid 45 Eugenia - Lightcurves and the pole orientation

    NASA Technical Reports Server (NTRS)

    Taylor, R. C.; Birch, P. V.; Surdej, J.; Pospieszalska-Surdej, A.

    1988-01-01

    Three lightcurves obtained in 1969 and six from 1984 are presented for the 250-km U-type asteroid Eugenia. The asteroid's north pole is within + or - 10 deg of ecliptic longitude 106 deg and a latitude of +26 deg, in keeping with an amplitude-aspect pole analysis. While only one maximum and one minimum are present when observations are closest to both the north and south poles, there are two of each at other oppositions. It is suggested that this effect may be due to the surface albedo features of Eugenia.

  4. Lightcurves and periods for asteroids 2103 Laverna and 3445 Pinson

    NASA Astrophysics Data System (ADS)

    Klinglesmith, Daniel A.; Jamieson, Quentin; Pilcher, Frederick

    2005-12-01

    Two asteroids were selected from the CALL list for asteroids with unknown periods. Data were obtained on 8 nights between March 30 and April 8, 2005. The period and amplitude results are: 2103 Laverna 9.249±0.003 hr, 0.27 mag; 3445 Pinson 7.801±0.002 hr, 0.37 mag. Laverna shows a bump on the second rising branch of its bimodal light curve while Pinson exhibits a more or less symmetrical bimodal lightcurve.

  5. Lightcurve and Rotation Period Determination for 2616 Lesya and (28910) 2000 NH11

    NASA Astrophysics Data System (ADS)

    Salvaggio, Fabio; Franco, Lorenzo; Marchini, Alessandro; Papini, Riccardo

    2016-04-01

    Photometric observations of the main-belt asteroids 2616 Lesya and (28910) 2000 NH11 were made in 2015 December. For 2616 Lesya, analysis found a bimodal lightcurve with a period of 9.219 ± 0.001 h. For (28910) 2000 NHA, the result was a bimodal lightcurve with a period of 5.970 ± 0.002 h.

  6. Twenty-three Asteroids Lightcurves at Observadores de Asteroides (OBAS): 2015 October - December

    NASA Astrophysics Data System (ADS)

    Aznar Macias, Amadeo; Carreno Garcerain, Alfonso; Arce Mansego, Enrique; Brines Rodriguez, Pedro; Lozano de Haro, Juan; Fornas Silva, Alvaro; Fornas Silva, Gonzalo; Mas Martinez, Vicente; Rodrigo Chiner, Onofre

    2016-04-01

    We report on the photometric analysis results for 23 main-belt asteroids (MBA) done by Observadores de Asteroides (OBAS). This work is part of the Minor Planet Photometric Database that was initiated by a group of Spanish amateur astronomers. We have managed to obtain a number of accurate, complete lightcurves as well as some additional incomplete lightcurves to help analysis at future oppositions.

  7. Lightcurves for Shape Modeling: 852 Wladilena, 1089 Tama, and 1180 Rita

    NASA Astrophysics Data System (ADS)

    Polishook, David

    2012-10-01

    The folded lightcurves and synodic periods of 852 Wladilena, 1089 Tama, and 1180 Rita are reported. The data are used by Hanus et al. (2012) to derive the rotation axis and to construct a shape model by applying the inversion lightcurve technique.

  8. Preliminary study of niobium alloy contamination by transport through helium

    NASA Technical Reports Server (NTRS)

    Scheuermann, C. M.; Moore, T. J.; Wheeler, D. R.

    1987-01-01

    Transport of gaseous contaminants through the working fluid to or from sensitive refractory alloys is theoretically possible during long time operation of Brayton and Stirling space power generation systems which use a gas as the working fluid. A test was designed which could give an answer to whether transport of contaminants through the working fluid was a potential major problem. The findings of that preliminary study are summarized.

  9. Preliminary dose comparisons for the MRS Systems Study

    SciTech Connect

    Pelto, P.J.; Lavender, J.C.

    1989-04-01

    This report provides preliminary information on the radiological doses to the public and the workers for alternative system configurations proposed in the MRS Systems Study. Information published in the MRS Environmental Assessment (DOE 1986) was used as a basis for this analysis. The risk differences between alternative configurations were found to be small and should not be viewed as a major factor in selecting alternative configurations. 1 ref.

  10. Deproteinated palm kernel cake-derived oligosaccharides: A preliminary study

    NASA Astrophysics Data System (ADS)

    Fan, Suet Pin; Chia, Chin Hua; Fang, Zhen; Zakaria, Sarani; Chee, Kah Leong

    2014-09-01

    Preliminary study on microwave-assisted hydrolysis of deproteinated palm kernel cake (DPKC) to produce oligosaccharides using succinic acid was performed. Three important factors, i.e., temperature, acid concentration and reaction time, were selected to carry out the hydrolysis processes. Results showed that the highest yield of DPKC-derived oligosaccharides can be obtained at a parameter 170 °C, 0.2 N SA and 20 min of reaction time.

  11. Designing Information Measures for Real-time Lightcurve Classification

    NASA Astrophysics Data System (ADS)

    Jones, David Edward; Chen, Yang; Meng, Xiao-Li; Siemiginowska, Aneta; Kashyap, Vinay

    2016-01-01

    Since telescope time is limited, real-time lightcurve classification involves carefully selecting future time points at which sources must be observed in order to maximize the information that will be gained for classification. We propose a framework for constructing measures of information for testing/classification/model-selection and demonstrate their use in experimental design. Degroot (1962) developed a general framework for constructing Bayesian measures of the expected information that an experiment will provide for estimation, and our framework analogously constructs measures of information for hypothesis testing. Such test information measures are most useful for model selection and classification problems. Indeed, our framework suggests a probability based measure of test information, which in decision problems has more appealing properties than variance based measures. In the case of lightcurve classification, we adapt our designs to penalize long waits until the next observation time. Lastly, we consider ways to address other aspects of the problem, such as uncertainty estimation arising due to contamination from nearby contaminating sources or background diffuse emission. We acknowledge support from Smithsonian Competitive Grants Fund 40488100HH0043 and NSF grant DMS 1208791.

  12. Applying Gaussian processes to Spitzer/IRAC transit lightcurves

    NASA Astrophysics Data System (ADS)

    Evans, Thomas

    2015-08-01

    For the past decade, transit and eclipse measurements made with Spitzer/IRAC have been used to characterize dozens of exoplanet atmospheres. However, lightcurves obtained with IRAC are affected by systematics that swamp the faint atmosphere signals being sought, as the instrument was not designed for ~100ppm photometry over >3hr timescales. Robustly quantifying the degeneracies between these systematics and the planet signal is therefore crucial for obtaining realistic uncertainty estimates, to avoid over-interpreting what the data have to tell us. This is challenging, because the nature of the instrumental systematics are not well-understood from a first principles standpoint. I will describe the application of Gaussian process (GPs) models to this problem, which is a relatively new approach in the exoplanet literature. Specifically, I will present transmission and emission results for the hot Jupiter HD209458b, and summarise how the new GP analysis draws into question a number of previous results, including inferences of strong water absorption in transmission and an inverted pressure-temperature profile for the dayside hemisphere. I will also outline the main challenges in applying GP models to datasets like the IRAC lightcurves, which typically contain well over 1000 data points and exhibit non-stationary systematics.

  13. A fast ellipsoid model for asteroids inverted from lightcurves

    NASA Astrophysics Data System (ADS)

    Lu, Xiao-Ping; Zhao, Hai-Bin; You, Zhong

    2013-04-01

    Research about asteroids has recently attracted more and more attention, especially focusing on their physical structures, such as their spin axis, rotation period and shape. The long distance between observers on Earth and asteroids makes it impossible to directly calculate the shape and other parameters of asteroids, with the exception of Near Earth Asteroids and others that have passed by some spacecrafts. Photometric measurements are still generally the main way to obtain research data on asteroids, i.e. the lightcurves recording the brightness and positions of asteroids. Supposing that the shape of the asteroid is a triaxial ellipsoid with a stable spin, a new method is presented in this article to reconstruct the shape models of asteroids from the lightcurves, together with other physical parameters. By applying a special curvature function, the method calculates the brightness integration on a unit sphere and Lebedev quadrature is employed for the discretization. Finally, the method searches for the optimal solution by the Levenberg-Marquardt algorithm to minimize the residual of the brightness. By adopting this method, not only can related physical parameters of asteroids be obtained at a reasonable accuracy, but also a simple shape model of an ellipsoid can be generated for reconstructing a more sophisticated shape model.

  14. Tree STEM Reconstruction Using Vertical Fisheye Images: a Preliminary Study

    NASA Astrophysics Data System (ADS)

    Berveglieri, A.; Tommaselli, A. M. G.

    2016-06-01

    A preliminary study was conducted to assess a tree stem reconstruction technique with panoramic images taken with fisheye lenses. The concept is similar to the Structure from Motion (SfM) technique, but the acquisition and data preparation rely on fisheye cameras to generate a vertical image sequence with height variations of the camera station. Each vertical image is rectified to four vertical planes, producing horizontal lateral views. The stems in the lateral view are rectified to the same scale in the image sequence to facilitate image matching. Using bundle adjustment, the stems are reconstructed, enabling later measurement and extraction of several attributes. The 3D reconstruction was performed with the proposed technique and compared with SfM. The preliminary results showed that the stems were correctly reconstructed by using the lateral virtual images generated from the vertical fisheye images and with the advantage of using fewer images and taken from one single station.

  15. Preliminary Study of a Hybrid Helicon-ECR Plasma Source

    NASA Astrophysics Data System (ADS)

    M. Hala, A.; Oksuz, L.; Ximing, Zhu

    2016-08-01

    A new type of hybrid discharge is experimentally investigated in this work. A helicon source and an electron cyclotron resonance (ECR) source were combined to produce plasma. As a preliminary study of this type of plasma, the optical emission spectroscopy (OES) method was used to obtain values of electron temperature and density under a series of typical conditions. Generally, it was observed that the electron temperature decreases and the electron density increases as the pressure increased. When increasing the applied power at a certain pressure, the average electron density at certain positions in the discharge does not increase significantly possibly due to the high degree of neutral depletion. Electron temperature increased with power in the hybrid mode. Possible mechanisms of these preliminary observations are discussed.

  16. DEEP-South: Preliminary Photometric Results from the KMTNet-CTIO

    NASA Astrophysics Data System (ADS)

    Kim, Myung-Jin; Moon, Hong-Kyu; Choi, Young-Jun; Yim, Hong-Suh; Bae, Young-Ho; Roh, Dong-Goo; Park, Jin Tae; Moon, Bora

    2016-01-01

    Korea Astronomy and Space Science Institute (KASI) successfully completed the development of Korea Microlensing Telescope Network (KMTNet, Park et al. 2012) in mid-2015, following which it conducted test runs for several months. `DEep Ecliptic Patrol of the Southern sky' (DEEP-South, Moon et al. 2015), which will be used for asteroid and comet studies, will not only characterize targeted asteroids, carrying out blind surveys toward the sweet spots, but will also mine the data of such bodies using the KMTNet archive. We report preliminary lightcurves of four Potentially Hazardous Asteroids (PHAs) from test runs at KMTNet-CTIO in the February - May 2015 period.

  17. Online gaming dependency: a preliminary study in China.

    PubMed

    Peng, Wei; Liu, Ming

    2010-06-01

    Based on theories and previous studies on problematic Internet use, we propose a model to better understand the contributors to and consequences of online gaming dependency. A preliminary study was conducted through a survey of online gamers in China. The results of path analysis found that maladaptive cognitions, shyness, and depression are positively related to online gaming dependency. Online gaming dependency was also positively related to different types of negative life outcomes. The findings of this study have implications for the prevention and treatment of addictive online gaming. PMID:20557254

  18. Preliminary Study for a Tetrahedron Formation: Quality Factors and Visualization

    NASA Technical Reports Server (NTRS)

    Guzman, Jose J.; Schiff, Conrad; Bauer, Frank (Technical Monitor)

    2002-01-01

    Spacecraft flying in tetrahedron formations are excellent for electromagnetic and plasma studies. The quality of the science recorded is strongly affected by the tetrahedron evolution. This paper is a preliminary study on the computation of quality factors and visualization for a formation of four or five satellites. Four of the satellites are arranged geometrically in a tetrahedron shape. If a fifth satellite is present, it is arbitrarily initialized at the geometric center of the tetrahedron. The fifth satellite could act as a collector or as a spare spacecraft. Tetrahedron natural coordinates are employed for the initialization. The natural orbit evolution is visualized in geocentric equatorial inertial and in geocentric solar magnetospheric coordinates.

  19. Light-Curve Survey of Jupiter Trojan Asteroids

    NASA Astrophysics Data System (ADS)

    Duffard, R.; Melita, M.; Ortiz, J. L.; Licandro, J.; Williams, I. P.; Jones, D.

    2008-09-01

    Trojan asteroids are an interesting population of minor bodies due to their dynamical characteristics, their physical properties and that they are relatively isolated located at the snow-line The main hypotheses about the origin of the Jupiter Trojans assumed that they formed either during the final stages of the planetary formation (Marzari & Scholl 1998), or during the epoch of planetary migration (Morbidelli et al. 2005), in any case more than 3.8 Gy. ago. The dynamical configuration kept the Trojans isolated from the asteroid Main Belt throughout the history of the Solar System. In spite of eventual interactions with other populations of minor bodies like the Hildas, the Jupiter family comets, and the Centaurs, their collisional evolution has been dictated mostly by the intrapopulation collisions (Marzari et al. 1996, 1997). Therefore, the Jupiter Trojans may be considered primordial bodies, whose dynamical and physical properties can provide important clues about the environment of planetary formation. The available sample of Jupiter Trojans light-curves is small and mainly restricted to the largest objects. According to the MPC-website (updated last in March 2006), the present sample of rotation periods and light-curve-amplitudes of the Jupiter Trojan asteroids is composed by 25 objects with some information about their periods and by 10 of them with only an amplitude estimation. A survey of contact binary Trojan asteroids has been done by Mann et al. 2007, where they have recorded more than 100 amplitudes from sparse-sampled light-curves and very-wellresolved rotational periods. More than 2000 Trojan asteroids have been discovered up to date, so, there is an urgent need to enlarge the sample of intrinsic rotation periods and accurate light-curve amplitudes and to extend it to smaller sizes. Results and Discusions We requested 26 nights of observation in the second semester of 2007, to begin with the survey. They were scheduled for the following instruments

  20. Imaging Starspots on LO Pegasi via Light-curve Inversion

    NASA Astrophysics Data System (ADS)

    Harmon, Robert O.; Deskins, R.; Vutisalchavakul, N.

    2007-12-01

    We present maps of the star LO Pegasi obtained via Light-curve Inversion, a computational technique which produces an image of a star's surface features based on variations in the star's observed brightness as dark starspots rotate into and out of view from Earth. LO Pegasi is a rapidly rotating (P=10.17 hr) K8V young solar analog. We inverted BVRI light curves obtained from CCD images acquired on July 7-9 and July 22-23, 2007 at Perkins Observatory in Delaware, OH. Using multiple filters significantly improves the latitude resolution of our maps. Our inversions revealed the presence of a large mid-latitude spot or spotted region on the map from July 7-9, which appears to have evolved into a more complex two-spot configuration by July 22-23. The authors wish to acknowledge the support of the NSF REU Program and the Ohio Wesleyan University Summer Science Research Program.

  1. Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2015 June-September

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.

    2016-01-01

    Lightcurves for 46 near-Earth asteroids (NEAs) were obtained at the Center for Solar System Studies-Palmer Divide Station (CS3-PDS) from 2015 June-September. Four of the asteroids showed indications of non-principal axis rotation (NPAR), or tumbling, (9400) 1994 TW1, (86666) 2000 FL10, (154807) 2004 PP97, and (206378) 2003 RB, but there were insufficient data for full analysis. On the other hand, 2015 JY1 is a confirmed tumbler with a dominate period of 6.442 h and a likely second period of 11.42 h. Evidence of the satellite for the known binary system (385186) 1994 AW1 was found. The estimated size ratio of Ds/Dp >= 0.25 is in good agreement with earlier results. A third period was also found but its origin is not confirmed.

  2. Biocontamination Control for Spacesuit Garments - A Preliminary Study

    NASA Technical Reports Server (NTRS)

    Rhodes, Richard A.; Orndoff, Evelyne; Korona, F. Adam; Poritz, Darwin; Smith, Jelanie; Wong, Wing

    2011-01-01

    This paper outlines a preliminary study that was conducted to review, test, and improve on current space suit biocontamination control. Biocontamination from crew members can cause space suit damage and objectionable odors and lead to crew member health hazards. An understanding of the level of biocontamination is necessary to mitigate its effects. A series of tests were conducted with the intent of evaluating current suit materials, ground and on-orbit disinfectants, and potential commercial off-the-shelf antimicrobial materials. Included in this paper is a discussion of the test methodology, results, and analysis method.

  3. Energy efficient engine: Preliminary design and integration studies

    NASA Technical Reports Server (NTRS)

    Johnston, R. P.; Hirschkron, R.; Koch, C. C.; Neitzel, R. E.; Vinson, P. W.

    1978-01-01

    Parametric design and mission evaluations of advanced turbofan configurations were conducted for future transport aircraft application. Economics, environmental suitability and fuel efficiency were investigated and compared with goals set by NASA. Of the candidate engines which included mixed- and separate-flow, direct-drive and geared configurations, an advanced mixed-flow direct-drive configuration was selected for further design and evaluation. All goals were judged to have been met except the acoustic goal. Also conducted was a performance risk analysis and a preliminary aerodynamic design of the 10 stage 23:1 pressure ratio compressor used in the study engines.

  4. Experimental Studies of Ion Beam Neutralization: Preliminary Results

    SciTech Connect

    Ding, N.; Polansky, J.; Downey, R.; Wang, J.

    2011-05-20

    A testing platform is designed to study ion beam neutralization in the mesothermal, collisionless region. In the experimental setup, argon neutrals were ionized in a microwave cavity and accelerated by a plasma lens system which was biased to 2500 V above the system ground. Electrons were boiled off from two hot tungsten filaments to neutralize the ion beam. The plasma is diagnosed using Langmuir probe and Faraday probe. A 3-D traversing system and a complete data acquisition loop were developed to efficiently measure 3-D beam profile. Preliminary measurements of beam profiles are presented for different operating conditions.

  5. Preliminary Study of a Pull Plug Friction Weld

    NASA Technical Reports Server (NTRS)

    Buchanan, George R.

    1999-01-01

    A pull plug friction weld, simply defined, comprises inserting a rotating cone-shaped cylinder into a somewhat cone-shaped hole in a plate. The rotating plug makes contact with the edge of the plate and the resulting friction generates heat. The temperature of the plate material eventually reaches a magnitude that will cause the plate material at the edge of the hole to flow. This can be termed a temperature dependent plastic flow. The rotation of the plug is terminated, additional pressure is applied and the metal at the interface of the two materials cools and welding occurs. This preliminary study addresses only three aspects of a complete analysis that is multi-faceted. The transient temperature distribution for different pull plug configurations has been studied in some detail even though the initial conditions and boundary conditions may still be deemed tentative. The stress distribution within the pull plug caused by the heating pressure was studied along with a preliminary analysis of the thermoelastic stress distribution caused by friction heating. There are no definitive results for the stress analysis. Additional study will be required.

  6. Preliminary design study of the TMT Telescope structure system: overview

    NASA Astrophysics Data System (ADS)

    Usuda, Tomonori; Ezaki, Yutaka; Kawaguchi, Noboru; Nagae, Kazuhiro; Kato, Atsushi; Takaki, Junji; Hirano, Masaki; Hattori, Tomoya; Tabata, Masaki; Horiuchi, Yasushi; Saruta, Yusuke; Sofuku, Satoru; Itoh, Noboru; Oshima, Takeharu; Takanezawa, Takashi; Endo, Makoto; Inatani, Junji; Iye, Masanori; Sadjadpour, Amir; Sirota, Mark; Roberts, Scott; Stepp, Larry

    2014-07-01

    We present an overview of the preliminary design of the Telescope Structure System (STR) of Thirty Meter Telescope (TMT). NAOJ was given responsibility for the TMT STR in early 2012 and engaged Mitsubishi Electric Corporation (MELCO) to take over the preliminary design work. MELCO performed a comprehensive preliminary design study in 2012 and 2013 and the design successfully passed its Preliminary Design Review (PDR) in November 2013 and April 2014. Design optimizations were pursued to better meet the design requirements and improvements were made in the designs of many of the telescope subsystems as follows: 1. 6-legged Top End configuration to support secondary mirror (M2) in order to reduce deformation of the Top End and to keep the same 4% blockage of the full aperture as the previous STR design. 2. "Double Lower Tube" of the elevation (EL) structure to reduce the required stroke of the primary mirror (M1) actuators to compensate the primary mirror cell (M1 Cell) deformation caused during the EL angle change in accordance with the requirements. 3. M1 Segment Handling System (SHS) to be able to make removing and installing 10 Mirror Segment Assemblies per day safely and with ease over M1 area where access of personnel is extremely difficult. This requires semi-automatic sequence operation and a robotic Segment Lifting Fixture (SLF) designed based on the Compliance Control System, developed for controlling industrial robots, with a mechanism to enable precise control within the six degrees of freedom of position control. 4. CO2 snow cleaning system to clean M1 every few weeks that is similar to the mechanical system that has been used at Subaru Telescope. 5. Seismic isolation and restraint systems with respect to safety; the maximum acceleration allowed for M1, M2, tertiary mirror (M3), LGSF, and science instruments in 1,000 year return period earthquakes are defined in the requirements. The Seismic requirements apply to any EL angle, regardless of the

  7. Preliminary design study of advanced multistage axial flow core compressors

    NASA Technical Reports Server (NTRS)

    Wisler, D. C.; Koch, C. C.; Smith, L. H., Jr.

    1977-01-01

    A preliminary design study was conducted to identify an advanced core compressor for use in new high-bypass-ratio turbofan engines to be introduced into commercial service in the 1980's. An evaluation of anticipated compressor and related component 1985 state-of-the-art technology was conducted. A parametric screening study covering a large number of compressor designs was conducted to determine the influence of the major compressor design features on efficiency, weight, cost, blade life, aircraft direct operating cost, and fuel usage. The trends observed in the parametric screening study were used to develop three high-efficiency, high-economic-payoff compressor designs. These three compressors were studied in greater detail to better evaluate their aerodynamic and mechanical feasibility.

  8. R&D Requirements, RF Gun Mode Studies, FEL-2 Steady-StateStudies, Preliminary FEL-1 Time-Dependent Studies, and Preliminary LayoutOption Investigation

    SciTech Connect

    Byrd, John; Corlett, John; Doolittle, Larry; Fawley, William; Lidia, Steven; Penn, Gregory; Ratti, Alex; Staples, John; Wilcox Russell; Wurtele, Jonathan; Zholents, Alexander

    2005-10-01

    This report constitutes the third deliverable of LBNLs contracted role in the FERMI {at} Elettra Technical Optimization study. It describes proposed R&D activities for the baseline design of the Technical Optimization Study, initial studies of the RF gun mode-coupling and potential effects on beam dynamics, steady-state studies of FEL-2 performance to 10 nm, preliminary studies of time-dependent FEL-1 performance using electron bunch distribution from the start-to-end studies, and a preliminary investigation of a configuration with FEL sinclined at a small angle from the line of the linac.

  9. Preliminary paleomagnetic study of the Thetford Mines Ordovician Ophiolite (Canada)

    NASA Astrophysics Data System (ADS)

    Di Chiara, Anita; Morris, Antony; Anderson, Mark

    2016-04-01

    Extension associated with oceanic ridges at divergent plate boundaries is characterized by normal faulting and episodic magma supply. Studies in modern oceanic settings suggest locally along ridges both lower crust and upper mantle peridotites may be exhumed to the seafloor in features known as oceanic core complexes (OCC). OCC are characterized by long-lived low-angle detachment faults that extend for 10s of km, and that are crosscut by high-angle normal faults oriented parallel to the rift axis. Here we present preliminary results from 12 paleomagnetic sites sampled on an example of fossilized Ordovician OCC preserved in the in the Canadian Appalachians, the Southern Quebec ophiolites. These were obducted and subjected to polyphase deformation during Palaeozoic orogeny along the Laurentian margin of Iapetus. Although locally obscured by tectonic fabrics and structures, the original relationships between the ophiolitic mantle, the overlying plutonic section, and onlapping Ordovician siliciclastic rocks can be reconstructed within the Thetford-Mines ophiolite. Preliminary results from AMS and Thermal demagnetization experiments record a remarkably consistent overprint from the youngest (Acadian) phase of Paleozoic orogeny. Although complicating further study of intra-oceanic deformation along the detachment fault in the original OCC, the results provide further insights into the progressive overprint of deformation events as recorded by AMS.

  10. Nevada potential repository preliminary transportation strategy Study 2. Volume 1

    SciTech Connect

    1996-02-01

    The objectives of this study were to build on the findings of the Nevada Potential Repository Preliminary Transportation Strategy Study 1 (CRWMS M&O 1995b), and to provide additional information for input to the repository environmental impact statement (EIS) process. In addition, this study supported the future selection of a preferred rail corridor and/or heavy haul route based on defensible data, methods, and analyses. Study research did not consider proposed legislation. Planning was conducted according to the Civilian Radioactive Waste Management Program Plan (DOE 1994a). The specific objectives of Study 2 were to: eliminate or reduce data gaps, inconsistencies, and uncertainties, and strengthen the analysis performed in Study 1; develop a preliminary list of rail route evaluation criteria that could be used to solicit input from stakeholders during scoping meetings. The evaluation criteria will be revised based on comments received during scoping; restrict and refine the width of the four rail corridors identified in Study 1 to five miles or less, based on land use constraints and engineering criteria identified and established in Study 2; evaluate national-level effects of routing spent nuclear fuel and high-level waste to the four identified branch lines, including the effects of routing through or avoiding Las Vegas; continue to gather published land use information and environmental data to support the repository EIS; continue to evaluate heavy haul truck transport over three existing routes as an alternative to rail and provide sufficient information to support the repository EIS process; and evaluate secondary uses for rail (passenger use, repository construction, shared use).

  11. Lightcurve Determination at the Bigmuskie Observatory from 2011 July-December

    NASA Astrophysics Data System (ADS)

    Ferrero, Andrea

    2012-04-01

    Lightcurves for eight asteroids were obtained at the Bigmuskie Observatory, Italy, during 2011 July- December: 613 Ginevra, 987 Wallia, 1718 Namibia, 1771 Makover, 2423 Ibarruri, 7750 McEwen, 6306 Nishimura, and (16959) 1998 QE17.

  12. Sampling the probability distribution of Type Ia Supernova lightcurve parameters in cosmological analysis

    NASA Astrophysics Data System (ADS)

    Dai, Mi; Wang, Yun

    2016-06-01

    In order to obtain robust cosmological constraints from Type Ia supernova (SN Ia) data, we have applied Markov Chain Monte Carlo (MCMC) to SN Ia lightcurve fitting. We develop a method for sampling the resultant probability density distributions (pdf) of the SN Ia lightcuve parameters in the MCMC likelihood analysis to constrain cosmological parameters, and validate it using simulated data sets. Applying this method to the `joint lightcurve analysis (JLA)' data set of SNe Ia, we find that sampling the SN Ia lightcurve parameter pdf's leads to cosmological parameters closer to that of a flat Universe with a cosmological constant, compared to the usual practice of using only the best-fitting values of the SN Ia lightcurve parameters. Our method will be useful in the use of SN Ia data for precision cosmology.

  13. Preliminary Studies for Three Experiments at Treiman-Yang Criterion

    NASA Astrophysics Data System (ADS)

    Kres, I. V.; Kondratyev, V. N.; Cherubini, S.; Spitaleri, C.

    2016-05-01

    Nuclear reactions with three bodies in their final state may proceed through different reaction mechanisms. The Feynman graph technique has been widely used to describe such reactions. However, it is very difficult in general to select the graphs that dominate in given process. The Treiman-Yang criterion is one of the most powerful experimental tests for verifying the pole approximation prediction when describing a quasi-free reaction mechanism. We propose the theoretical study of the H2(B10, α Be7)ns, H1(B11, α1α2)αs, He3(Be9, α1α2)αs reactions at different energies. The preliminary study helps to check the existence of a QF channel by using the TY creterion.

  14. Characterization of burns using hyperspectral imaging technique - a preliminary study.

    PubMed

    Calin, Mihaela Antonina; Parasca, Sorin Viorel; Savastru, Roxana; Manea, Dragos

    2015-02-01

    Surgical burn treatment depends on accurate estimation of burn depth. Many methods have been used to asses burns, but none has gained wide acceptance. Hyperspectral imaging technique has recently entered the medical research field with encouraging results. In this paper we present a preliminary study (case presentation) that aims to point out the value of this optical method in burn wound characterization and to set up future lines of investigation. A hyperspectral image of a leg and foot with partial thickness burns was obtained in the fifth postburn day. The image was analyzed using linear spectral unmixing model as a tool for mapping the investigated areas. The article gives details on the mathematical bases of the interpretation model and correlations with clinical examination pointing out the advantages of hyperspectral imaging technique. While the results were encouraging, further more extended and better founded studies are being prepared before recognizing hyperspectral imaging technique as an applicable method of burn wound assessment. PMID:24997530

  15. Preliminary study: isotopic safeguards techniques (IST) LMFBR fuel cycles

    SciTech Connect

    Persiani, P. J.; Kroc, T. K.

    1980-06-01

    This memorandum presents the preliminary results of the effort to investigate the applicability of isotope correlation techniques (ICT), formulated for the LWR system, to the LMFBR fuel cycle. The detailed isotopic compositional changes with burnup developed for the CRBR was utilized as the reference case. This differs from the usual LMFBR design studies in that the core uranium is natural uranium rather than depleted. Nevertheless, the general isotopic behavior should not differ significantly and does allow an initial insight into the expected behavior of isotopic correlations for the LMFBR power systems such as: the U.K. PFR and reprocessing plant; the French Phenix and Superphenix; and the US reference conceptual design studies (CDS) of homogeneous and heterogeneous LMFBR systems as they are developed.

  16. Possession experiences in dissociative identity disorder: a preliminary study.

    PubMed

    Ross, Colin A

    2011-01-01

    Dissociative trance disorder, which includes possession experiences, was introduced as a provisional diagnosis requiring further study in the Diagnostic and Statistical Manual of Mental Disorders (4th ed.). Consideration is now being given to including possession experiences within dissociative identity disorder (DID) in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.), which is due to be published in 2013. In order to provide empirical data relevant to the relationship between DID and possession states, I analyzed data on the prevalence of trance, possession states, sleepwalking, and paranormal experiences in 3 large samples: patients with DID from North America; psychiatric outpatients from Shanghai, China; and a general population sample from Winnipeg, Canada. Trance, sleepwalking, paranormal, and possession experiences were much more common in the DID patients than in the 2 comparison samples. The study is preliminary and exploratory in nature because the samples were not matched in any way. PMID:21667381

  17. Reactivity to sensations in borderline personality disorder: a preliminary study.

    PubMed

    Rosenthal, M Zachary; Ahn, Roianne; Geiger, Paul J

    2011-10-01

    Individuals with borderline personality disorder (BPD) are widely considered to have problems with emotional reactivity. However, the specific kinds of stimuli that are associated with heightened emotional reactivity in BPD have not been well characterized. Thus, it is unclear whether the emotional dysfunction in BPD occurs in response to any emotionally evocative stimuli, or to specific classes of stimuli. In this study, we used subjective measures (self-report and interview-based) to compare reactivity to sensations (auditory, gustatory, olfactory, tactile, visual) between participants with BPD (n = 30) and healthy controls (n = 50). Controlling for trait negative emotional reactivity, individuals with BPD reported being significantly more reactive across sensory stimuli. However, the difference between controls and BPD was significantly greater for reactivity to auditory stimuli compared to other sensory stimuli. Findings from this study provide preliminary data suggesting individuals with BPD may be characterized by heightened self-reported reactivity to aversive sounds. PMID:22023306

  18. Asteroid lightcurve inversion using Lommel-Seeliger ellipsoids

    NASA Astrophysics Data System (ADS)

    Muinonen, K.; Wilkman, O.; Wang, X.; Cellino, A.

    2014-07-01

    The rotational period, pole orientation, and convex three-dimensional shape of an asteroid can be derived from photometric lightcurves observed in a number of apparitions with varying illumination and observation geometries (e.g., Kaasalainen et al. 2001, Torppa et al. 2008, Durech et al. 2009). It is customary to estimate the rotational period with a simplified shape model and a small number of trial pole orientations. Once the period is available, the pole orientation can be refined with a general convex shape model represented by the spherical harmonics expansion for the Gaussian surface density. Once the Gaussian surface density is available, the actual convex shape is constructed as a solution of the Minkowski problem. We focus on the initial derivation of the rotational period and pole orientation with the help of the Lommel-Seeliger ellipsoid (LS-ellipsoid), a triaxial ellipsoid with a Lommel-Seeliger surface scattering law. The disk-integrated photometric brightness for the LS-ellipsoid is available in a closed form (Muinonen and Lumme, in preparation), warranting efficient direct computation of lightcurves. With modern computers and the LS-ellipsoid, the rotation period, pole orientation, and ellipsoidal shape can be derived, in principle, simultaneously (see Cellino et al., present meeting). However, here we choose to proceed systematically as follows. First, the rotation period is scanned systematically across its relevant range with a resolution of P_0^2/2T dictated by a tentative period estimate P_0 and the time interval spanned by the photometric data T. This is typically carried out for a small number of pole orientations distributed uniformly on a unit sphere. For each pole orientation, the ellipsoid pole orientation, rotational phase, and axial ratios are optimized with the help of the Nelder-Mead downhill simplex method. Although the shape optimization can suffer from getting stuck in local minima, overall, the rotation period is fairly accurately

  19. Preliminary studies of electromagnetic sounding of cometary nuclei

    NASA Technical Reports Server (NTRS)

    Gabriel, A.; Warne, L.; Bednarczyk, S.; Elachi, C.

    1978-01-01

    The internal structure of a comet could be determined with a spacecraft borne electromagnetic sounder. A dielectric profile of the comet could be produced in direct analogy with terrestrial glacier and ice sheet sounding experiments. This profile would allow the detection of a rocky core or ice layers if they exist, just as layers in the ice and the bedrock interface have been clearly observed through the Greenland ice sheet. It would also provide a gross estimate of the amount of dust in the icy region. Models for the response of the nucleus and cometary plasma to electromagnetic sounding are developed and used to derive experimental parameters. A point system design was completed. Preliminary engineering study results indicate that the sounder is well within the bounds of current space technology.

  20. Mathematical modeling of normal pharyngeal bolus transport: a preliminary study.

    PubMed

    Chang, M W; Rosendall, B; Finlayson, B A

    1998-07-01

    Dysphagia (difficulty in swallowing) is a common clinical symptom associated with many diseases, such as stroke, multiple sclerosis, neuromuscular diseases, and cancer. Its complications include choking, aspiration, malnutrition, cachexia, and dehydration. The goal in dysphagia management is to provide adequate nutrition and hydration while minimizing the risk of choking and aspiration. It is important to advance the individual toward oral feeding in a timely manner to enhance the recovery of swallowing function and preserve the quality of life. Current clinical assessments of dysphagia are limited in providing adequate guidelines for oral feeding. Mathematical modeling of the fluid dynamics of pharyngeal bolus transport provides a unique opportunity for studying the physiology and pathophysiology of swallowing. Finite element analysis (FEA) is a special case of computational fluid dynamics (CFD). In CFD, the flow of a fluid in a space is modeled by covering the space with a grid and predicting how the fluid moves from grid point to grid point. FEA is capable of solving problems with complex geometries and free surfaces. A preliminary pharyngeal model has been constructed using FEA. This model incorporates literature-reported, normal, anatomical data with time-dependent pharyngeal/upper esophageal sphincter (UES) wall motion obtained from videofluorography (VFG). This time-dependent wall motion can be implemented as a moving boundary condition in the model. Clinical kinematic data can be digitized from VFG studies to construct and test the mathematical model. The preliminary model demonstrates the feasibility of modeling pharyngeal bolus transport, which, to our knowledge, has not been attempted before. This model also addresses the need and the potential for CFD in understanding the physiology and pathophysiology of the pharyngeal phase of swallowing. Improvements of the model are underway. Combining the model with individualized clinical data should potentially

  1. Preliminaries toward studying resonant extraction from the Debuncher

    SciTech Connect

    Michelotti, Leo; Johnstone, John; /Fermilab

    2009-06-01

    A recent proposal to detect {mu} {yields} e direct conversion at Fermilab asks for slow extraction of protons from the antiproton source, specifically from the Debuncher. [1] A third-integer resonance originally was considered for this, partly because of the Debuncher's three-fold symmetry and partly because its operational horizontal tune, {nu}{sub x} {approx} 9.765, is already within 0.1 of {nu}{sub x} = 29/3. Using a half integer resonance, {nu}{sub x} = 19/2, though not part of the original proposal, has been suggested more recently because (a) Fermilab has had a good deal of experience with half-integer extraction from the Tevatron, the Main Injector and the erstwhile Main Ring, and (b) for reasons we shall examine later, it depopulates the entire bunch without an abort at the end. This memo presents considerations preliminary to studying both possibilities. It is meant only as a starting point for investigations to be carried out in the future. The working constraints and assumptions have oscillated between two extremes: (1) making minimal changes in the antiproton source to minimize cost and (2) building another machine in the same tunnel. In this memo we adopt an attitude aligned more toward the first. The assumed parameters are listed in Table 1. A few are not (easily) subject to change, such as those related to the beam's momentum and revolution frequency and the acceptance of the debuncher. Two resonance exemplars are presented in the next section, with an explanation of the analytic and semi-analytic calculations that can be done for each. Section 3 contains preliminary numerical work that was done to validate the exemplars within the context of extraction from the Debuncher. A final section contains a summary. Following the bibliography, appendices contain (a) a qualitative, conceptual discussion of extraction for the novice, (b) a telegraphic review of the perturbative incantations used to filter the exemplars as principal resonances of quadrupole

  2. A photoelectric lightcurve survey of small main belt asteroids

    NASA Technical Reports Server (NTRS)

    Binzel, R. P.; Mulholland, J. D.

    1983-01-01

    A survey to obtain photoelectric lightcurves of small main-belt asteroids was conducted from November 1981 to April 1982 using the 0.91- and 2.1-m telescopes at the University of Texas McDonald Observatory. A total of 18 main-belt asteroids having estimated dimaters under 30 km were observed with over half of these being smaller than 15 km. Rotational periods were determined or estimated from multiple nights of observation for nearly all of these yielding a sample of 17 small main-belt asteroids which is believed to be free of observational selection effects. All but two of these objects were investigated for very short periods in the range of 1 min to 2 hr using power spectrum analysis of a continuous set of integrations. No evidence for such short periods was seen in this sample. Rotationally averaged B(1,0) magnitudes were determined for most of the surveyed asteroids, allowing diameter estimates to be made. Imposing the suspected selection effects of photogaphic photometry on the results of this survey gives excellent agreement with the results from that technique. This shows that the inability of photographic photometry to obtain results for many asteroids is indeed due to the rotational parameter of those asteroids.

  3. Imaging Starspots on II Pegasi via Light-curve Inversion

    NASA Astrophysics Data System (ADS)

    Vutisalchavakul, Nalin; Deskins, Ryan; Harmon, Robert

    2007-10-01

    Starspots on the star II Pegasi were mapped via the method of Light-curve Inversion, which infers the appearance of the dark spots based on the brightness variations they produce as the star rotates. Our data were obtained with the 0.4-meter Vanderbilt/Tennessee State University Automated Photometric Telescope from September 1995 to January 1996 and from November 1988 to September 1992 (Henry, et al. 1995, ApJSS, 97, 513). For the first data set our results suggest that II Peg has opposite differential rotation to that of the Sun, with higher latitude spots having shorter rotation periods. We analyzed the second data set in an attempt to confirm this, but found that no definite conclusion could be drawn, though differential rotation is clearly present. The difficulty arises in part because the data were obtained through only two photometric filters (B and V), which limits the resolution in latitude. Future observations of the star through a larger set of filters might resolve this ambiguity.

  4. Archaeoastronomical Information in the Study of Cremation Necropolis: Preliminary Study

    NASA Astrophysics Data System (ADS)

    Mejuto, J.; Cerde, M. L.; Rodríguez, C.

    2009-08-01

    This work remarks the significance that archaeoastronomical studies have for archaeological research. These studies provide us data about the perception that ancient societies had about astronomical events and how these facts were added to their religious and ideological world. Thus, archaeoastronomy become a valuable source of information when aimed to solve any question involving the ancient societies. We take as reference in this work some of the Late Bronze Age{'}s cremation necropolis, representatives of usually called Urnfields, to check if their design can be related to some celestial phenomena: Can Bech de Baix (Gerona), Can Pitieu-Can Roqueta(Barcelona), Molá (Tarragona), Can Missert (Tarragona), Les Obagues (Tarragona), La Colomina (Lleida) and La Torraza (Navarra). Likewise a new standard in archaeological excavations maps is proposed. This will allow getting the information more available and improving further studies.

  5. Lightcurves of Type Ia Supernovae from Near the Time of Explosion

    SciTech Connect

    Garg, A; Stubbs, C W; Challis, P; Wood-Vasey, M; Blondin, S; Huber, M E; Cook, K; Nikolaev, S; Rest, A; Smith, R C; Olsen, K; Suntzeff, N B; Aguilera, C; Prieto, J L; Becker, A; Miceli, A; Miknaitis, G; Clocchiatti, A; Minniti, D; Morelli, L; Welch, D

    2006-08-30

    We present a set of 11 type Ia supernova (SN Ia) lightcurves with dense, pre-maximum sampling. These supernovae (SNe), in galaxies behind the Large Magellanic Cloud (LMC), were discovered by the SuperMACHO survey. The SNe span a redshift range of z = 0.11-0.35. Our lightcurves contain some of the earliest pre-maximum observations of SNe Ia to date. We also give a functional model that describes the SN Ia lightcurve shape (in our V R-band). Our function uses the ''expanding fireball'' model of Goldhaber et al. (1998) to describe the rising lightcurve immediately after explosion but constrains it to smoothly join the remainder of the lightcurve. We fit this model to a composite observed V R-band lightcurve of three SNe between redshifts of 0.135 to 0.165. These SNe have not been K-corrected or adjusted to account for reddening. In this redshift range, the observed V R-band most closely matches the rest frame V-band. Using the best fit to our functional description of the lightcurve, we find the time between explosion and observed V R-band maximum to be 19.2 {+-} 1.3-1.6 {+-} 0.07(red.) rest-frame days for a SN Ia with a V R-band {Delta}m{sub -10} of 0.52. For the redshifts sampled, the observed V R-band time-of-maximum brightness should be the same as the rest-frame V -band maximum to within 1.1 rest-frame days.

  6. Preliminary studies to determine the shelf life of HEPA filters

    SciTech Connect

    Gilbert, H.; Fretthold, J.K.; Rainer, F.; Bergman, W.; Beason, D.

    1994-07-18

    We have completed a preliminary study using filter media tests and filter qualification tests to investigate the effect of shelf-life on HEPA filter performance. Our media studies showed that the tensile strength decreased with age, but the data were not sufficient to establish a shelf-life. Thermogravimetric analyses demonstrated that one manufacturer had media with low tensile strength due to insufficient binder. The filter qualification tests (heated air and overpressure) conducted on different aged filters showed that filter age is not the primary factor affecting filter performance; materials and the construction design have a greater effect. An unexpected finding of our study was that sub-standard HEPA filters have been installed in DOE facilities despite existing regulations and filter qualification tests. We found that the filter with low tensile strength failed the overpressure test. The same filter had passed the heated air test, but left the filter so structurally weak, it was prone to blowout. We recommend that DOE initiate a filter qualification program to prevent this occurrence.

  7. Preliminary Study of a Model Rotor in Descent

    NASA Technical Reports Server (NTRS)

    McAlister, K. W.; Tung, C.; Sharpe, D. L.; Huang, S.; Hendley, E. M.

    2000-01-01

    Within a program designed to develop experimental techniques for measuring the trajectory and structure of vortices trailing from the tips of rotor blades, the present preliminary study focuses on a method for quantifying the trajectory of the trailing vortex during descent flight conditions. This study also presents rotor loads and blade surface pressures for a range of tip-path plane angles and Mach numbers. Blade pressures near the leading edge and along the outer radius are compared with data obtained on the same model rotor, but in open jet facilities. A triangulation procedure based on two directable laser-light sheets, each containing an embedded reference, proved effective in defining the spatial coordinates of the trailing vortex. When interrogating a cross section of the flow that contains several trailing vortices, the greatest clarity was found to result when the flow is uniformly seeded. Surface pressure responses during blade-vortex interactions appeared equally sensitive near the leading edge and along the outer portion of the blade, but diminished rapidly as the distance along the blade chord increased. The pressure response was virtually independent of whether the tip-path plane angle was obtained through shaft tilt or cyclic pitch. Although the shape and frequency of the pressure perturbations on the advancing blade during blade-vortex interaction are similar to those obtained in open-jet facilities, the angle of the tip-path plane may need to be lower than the range covered in this study.

  8. Preliminary studies to determine the shelf life of HEPA filters

    SciTech Connect

    Gilbert, H.; Fretthold, J.K.; Rainer, F.

    1995-02-01

    We have completed a preliminary study using filter media tests and filter qualification tests to investigate the effect of shelf-life on HEPA filter performance. Our media studies showed that the tensile strength decreased with age, but the data were not sufficient to establish a shelf-life. Thermogravimetric analyses demonstrated that one manufacturer had media with low tensile strength due to insufficient binder. The filter qualification tests (heated air and overpressure) conducted on different aged filters showed that filter age is not the primary factor affecting filter performance; materials and the construction design have a greater effect. An unexpected finding of our study was that sub-standard HEPA filters have been installed in DOE facilities despite existing regulations and filter qualification tests. We found that the filter with low tensile strength failed the overpressure test. The same filter had passed the heated air test, but left the filter so structurally weak, it was prone to blow-out. We recommend that DOE initiate a filter qualification program to prevent this occurrence.

  9. Preliminary Trade Study of Phase Change Heat Sinks

    NASA Technical Reports Server (NTRS)

    Anderson, Molly; Leimkeuhler, Thomas; Quinn, Gregory; Golliher, Eric

    2006-01-01

    For short durations, phase change based heat rejection systems are a very effective way of removing heat from spacecraft. Future NASA vehicles, such as the Crew Exploration Vehicle (CEV), will require non-radiative heat rejection systems during at least a portion of the planned mission, just as their predecessors have. While existing technologies are available to modify, such as Apollo era sublimators, or the Space Shuttle Flash Evaporator System (FES), several new technologies are under development or investigation to progress beyond these existing heat rejection systems. Examples include the Multi-Fluid Evaporator developed by Hamilton Sundstrand, improvements upon the Contaminant Insensitive Sublimator originally developed for the X-38 program, and a Compact Flash Evaporator System (CFES). Other possibilities evaluate new ways of operating existing designs. The new developments are targeted at increasing operating life, expanding the environments in which the system can operate, improving the mass and volume characteristics, or some combination of these or other improvements. This paper captures the process and results of a preliminary trade study performed at Johnson Space Center to compare the various existing and proposed phase change based heat rejection systems for the CEV. Because the new systems are still in development, and the information on existing systems is extrapolation, this trade study is not meant to suggest a final decision for future vehicles. The results of this early trade study are targeted to aid the development efforts for the new technologies by identifying issues that could reduce the chances of selection for the CEV.

  10. Experience from the Argentine Pegvisomant Observational Study: preliminary data.

    PubMed

    García Basavilbaso, N; Guitelman, M; Nagelberg, A; Stalldecker, G; Carabelli, A; Bruno, O; Danilowitz, K; Manavela, M; Mallea Gil, S; Ballarino, C; Guelman, R; Katz, D; Fidalgo, S; Leal, R; Fideleff, H; Servidio, M; Bruera, D; Librandi, F; Chervin, A; Vitale, M; Basso, A

    2010-01-01

    The GH receptor antagonist pegvisomant is an efficient agent to achieve biochemical control of acromegaly in those cases refractory to surgery and medical therapy with somatostatin analogs. We conducted an observational multicenter study consisting of data collection in accordance with the standard management of patients with acromegaly in everyday practice. We reviewed the medical records of 28 patients, 23 females, who were treated with pegvisomant due to the lack of biochemical response or intolerance to the somatostatin analogs. The objective was to monitor long-term safety and efficacy of the antagonist. 82% of the patients had previous pituitary surgery, 53.6% radiotherapy and 96.4% received medical therapy for acromegaly. Only 19.2% of the patients had pituitary residual tumor size larger than 1 cm, the remainder harbored a microadenoma or no visible tumor in the pituitary images. In terms of biochemical efficacy, IGF-I levels decreased to normal ranges in 45% and 58.8% of patients after 3 and 6 months of treatment, respectively, the daily mean dose of pegvisomant being 9.6+/-1.1 mg. Adverse events, potentially related to pegvisomant were reported in 6 patients (21.4%), local injection site reaction and elevated liver enzymes being the most frequent. Tumor size did not show enlargement in the evaluated population (15 patients) during the period of the study. This paper presents preliminary data from a small observational study in Argentina which represents the first database in our country. PMID:20616494

  11. Titan Lake Probe: The Ongoing NASA Decadal Study Preliminary Report

    NASA Astrophysics Data System (ADS)

    Waite, J. Hunter; Brockwell, Tim; Elliot, John; Reh, Kim; Spencer, John; Outer Planets Satellites Decadal Subpanel, The

    2010-05-01

    This talk provides an update on the scientific requirements and preliminary design of a Titan Lake Probe for a future NASA Flagship mission. The starting point for this study is the joint NASA ESA TSSM mission. Using this as a starting point we have revisited the scientific requirements and expanded them to include the possibility of a lake floater and a submersible. The preliminary results of this ongoing study will be presented. The scientific objectives of a Titan Lake Probe mission are: 1) to understand the formation and evolution of Titan and its atmosphere through measurement of the composition of the target lake (e.g., Kraken Mare), with particular emphasis on the isotopic composition of dissolved minor species and on dissolved noble gases, 2) to study the lake-atmosphere interaction in order to determine the role of Titan's lakes in the methane cycle, 3) to investigate the target lake as a laboratory for both pre-biotic organic chemistry in both water (or ammonia-enriched water) solutions and non-water solvents, and 4) to determine if Titan has an interior ocean by measuring tidal changes in the level of the lake over the course of Titan's sixteen-day orbit. The driving requirements for the mission are: 1) the need to land on and explore the lake at depth while adequately communicating the data back to Earth via either direct to Earth or relay communications, 2) thermal design that allows sustained (>32 days) sampling of the 94K lake environment, and 3) a mass spectrometer inlet system that allows sampling of gas, liquid, and solids from the 94K environment. The primary payload is an analytical chemistry laboratory that includes an inlet system for sampling gas, liquid, and solids in and above the lake feeding two capable mass spectrometers that determine the organic and isotopic composition of the sampled materials. The instrumentation also includes a meteorological package that can measure the rate of gas exchange between the lake and the atmosphere, and

  12. On the shape and albedo variegation of asteroids - Results from Fourier analysis of synthetic and observed asteroid lightcurves

    NASA Technical Reports Server (NTRS)

    Barucci, M. Antonietta; Capria, M. Teresa; Harris, Alan W.; Fulchignoni, Marcello

    1989-01-01

    Fourier analyses have been conducted of those asteroids in the Lagerkvist et al. (1987) lightcurves with substantially complete phase coverage and point density, and for which a unique period has been identified. Fourier coefficients are thereby obtained for 188 lightcurves of 91 asteroids, as well as for 868 synthetic lightcurves from a set of models different in shape and albedo markings; by comparing model and asteroid lightcurve coefficients, the possible shape and albedo variations for 18 asteroids are derived. An attempt is made to define the general distribution of shapes of all asteroid samples analyzed.

  13. Preliminary design studies on the Broad Application Test Reactor

    SciTech Connect

    Terry, W.J.; Terry, W.K.; Ryskamp, J.M.; Jahshan, S.N.; Fletcher, C.D.; Moore, R.L.; Leyse, C.F.; Ottewitte, E.H.; Motloch, C.G.; Lacy, J.M.

    1992-08-01

    This report describes progress made at the Idaho National Engineering Laboratory during the first three quarters of Fiscal Year (FY) 1992 on the Laboratory-Directed Research and Development (LDRD) project to perform preliminary design studies on the Broad Application Test Reactor (BATR). This work builds on the FY-92 BATR studies, which identified anticipated mission and safety requirements for BATR and assessed a variety of reactor concepts for their potential capability to meet those requirements. The main accomplishment of the FY-92 BATR program is the development of baseline reactor configurations for the two conventional conceptual test reactors recommended in the FY-91 report. Much of the present report consists of descriptions and neutronics and thermohydraulics analyses of these baseline configurations. In addition, we considered reactor safety issues, compared the consequences of steam explosions for alternative conventional fuel types, explored a Molten Chloride Fast Reactor concept as an alternate BATR design, and examined strategies for the reduction of operating costs. Work planned for the last quarter of FY-92 is discussed, and recommendations for future work are also presented.

  14. Physico-Chemical profile of Puga Khanda: A Preliminary Study

    PubMed Central

    Baragi, Pramod C.; Baragi, Umapati C.; Bhat, Sathyanarayana; Prajapati, Pradeep Kumar

    2014-01-01

    Background: Herbal medicines are the oldest known form of medicine in the world. However, the quality control and the assurance still remains a challenge because of the high variability of chemical components. Herbal drugs, singlely or in combinations, contain numerous compounds in complex matrices in which no single active constituent is responsible for the overall efficacy. This creates a challenge in establishing quality control standards and the standardization of finished herbal products. Many formulations have been mentioned in Ayurvedic text for Vrushyatwa (aphrodisiac). Puga Khanda is one among such formulations. Aim: To develop preliminary physico-chemical profile of Puga Khanda. Materials and Methods: Puga Khanda was prepared in three batches as per the classical reference mentioned in Bhaishajya Ratnavali. The formulation was subjected for physico-chemical analysis, phytochemical analysis and Thin Layer Chromatography (TLC). Results and Conclusion: The study revealed that organoleptic characters, pH and extractive values of all 3 samples were almost equal. All the samples had 60% of sugar needed for preservation and 2/3rd of it was non reducing sugar. The total alkaloids ranged from 0.002 to 0.004% w/w. In TLC study the entire samples showed similar pattern except the 2nd sample of Puga Khanda. PMID:25364209

  15. A Preliminary Study of a Solar-Probe Mission

    NASA Technical Reports Server (NTRS)

    Dugan, Duane W.

    1961-01-01

    A preliminary study is made of some problems associated with the sending of an instrumented probe close to the Sun for the purpose of gathering and telemetering back to Earth information concerning solar phenomena and circumsolar space. The problems considered are primarily those relating to heating and to launch requirements. A nonanalytic discussion of the communications problem of a solar-probe mission is presented to obtain order-of-magnitude estimates of the output and weight of an auxiliary power supply which might be required. From the study it is believed that approaches to the Sun as close as about 4 or 5 million miles do not present insuperable difficulties insofar as heating and communications are concerned. Guidance requirements, in general, do not appear to be stringent. However, in terms of current experience, velocity requirements may be large. It is found, for example, that to achieve perihelion distances between the orbit of Mercury and the visible disc of the Sun, total burnout velocities ranging between 50,000 and 100,000 feet per second are required.

  16. Energy efficient engine preliminary design and integration study

    NASA Technical Reports Server (NTRS)

    Gray, D. E.

    1978-01-01

    The technology and configurational requirements of an all new 1990's energy efficient turbofan engine having a twin spool arrangement with a directly coupled fan and low-pressure turbine, a mixed exhaust nacelle, and a high 38.6:1 overall pressure ratio were studied. Major advanced technology design features required to provide the overall benefits were a high pressure ratio compression system, a thermally actuated advanced clearance control system, lightweight shroudless fan blades, a low maintenance cost one-stage high pressure turbine, a short efficient mixer and structurally integrated engine and nacelle. A conceptual design analysis was followed by integration and performance analyses of geared and direct-drive fan engines with separate or mixed exhaust nacelles to refine previously designed engine cycles. Preliminary design and more detailed engine-aircraft integration analysis were then conducted on the more promising configurations. Engine and aircraft sizing, fuel burned, and airframe noise studies on projected 1990's domestic and international aircraft produced sufficient definition of configurational and advanced technology requirements to allow immediate initiation of component technology development.

  17. Intraarterial Ultrasound in Pancreatic Cancer: Feasibility Study and Preliminary Results

    SciTech Connect

    Larena-Avellaneda, Axel; Timm, Stephan; Kickuth, Ralph; Kenn, Werner; Steger, Ulrich; Jurowich, Christian; Germer, Christoph-Thomas

    2010-08-15

    Despite technological advances in computed tomography (CT) and magnetic resonance imaging, the involvement of the celiac or mesenteric artery in pancreatic cancer remains uncertain in many cases. Infiltration of these vessels is important in making decisions about therapy choices but often can only be definitively determined through laparotomy. Local (intraarterial) ultrasound may increase diagnostic accuracy. Using the Volcano intravascular ultrasound (IVUS) system, we applied a transfemoral method to scan the celiac and mesenteric arteries directly intraarterial. This technique was used in five patients with suspected pancreatic cancer. Technical success was achieved in all cases. In one case, a short dissection of the mesenteric artery occurred but could be managed interventionally. In tumors that did not contact with the vessels, IVUS was unable to display the tissue pathology. Our main interest was the infiltration of the arteries. In one case, infiltration was certain in the CT scan but uncertain in two patients. In the latter two cases, IVUS correctly predicted infiltration in one and freedom from tumor in the other case. In our preliminary study, IVUS correctly predicted arterial infiltration in all cases. IVUS did not provide new information when the tumor was far away from the vessel. Compared with IVUS in the portal vein, the information about the artery is more detailed, and the vessel approach is easier. These results encouraged us to design a prospective study to evaluate the sensitivity and specificity of this method.

  18. Gasoline on hands: preliminary study on collection and persistence.

    PubMed

    Darrer, Melinda; Jacquemet-Papilloud, Joëlle; Delémont, Olivier

    2008-03-01

    The identification of an arsonist remains one of the most difficult challenges a fire investigation has to face. Seeking and detection of traces of gasoline could provide a valuable information to link a suspect with an arson scene where gasoline was used to set-up the fire. In this perspective, a first study was undertaken to evaluate a simple, fast and efficient method for collecting gasoline from hands, and to assess its persistence over time. Four collection means were tested: PVC, PE and Latex gloves, as well as humidified filter paper. A statistical assessment of the results indicates that Latex and PVC gloves worn for about 20 min, as well as paper filter rubbed on hands, allow an efficient collection of gasoline applied to hands. Due to ease of manipulation and to a reduced amount of volatile compounds detected from the matrix, PVC gloves were selected for the second set of experiments. The evaluation of the persistence of gasoline on hands was then carried out using two initial quantities (500 and 1000 microl). Collection was made with PVC gloves after 0, 30 min, 1, 2 and 4h, on different volunteers. The results show a common tendency of massive evaporation of gasoline during the first 30 min: a continued but non-linear decrease was observed along different time intervals. The results of this preliminary study are in agreement with other previous researches conducted on the detection of flammable liquid residues on clothes, shoes and skin. PMID:17714900

  19. A preliminary study of Mars rover/sample return missions

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The Solar System Exploration Committee (SSEC) of the NASA Advisory Council recommends that a Mars Sample Return mission be undertaken before the year 2000. Comprehensive studies of a Mars Sample Return mission have been ongoing since 1984. The initial focus of these studies was an integrated mission concept with the surface rover and sample return vehicle elements delivered to Mars on a single launch and landed together. This approach, to be carried out as a unilateral U.S. initiative, is still a high priority goal in an Augmented Program of exploration, as the SSEC recommendation clearly states. With this background of a well-understood mission concept, NASA decided to focus its 1986 study effort on a potential opportunity not previously examined; namely, a Mars Rover/Sample Return (MRSR) mission which would involve a significant aspect of international cooperation. As envisioned, responsibility for the various mission operations and hardware elements would be divided in a logical manner with clearly defined and acceptable interfaces. The U.S. and its international partner would carry out separately launched but coordinated missions with the overall goal of accomplishing in situ science and returning several kilograms of surface samples from Mars. Important considerations for implementation of such a plan are minimum technology transfer, maximum sharing of scientific results, and independent credibility of each mission role. Under the guidance and oversight of a Mars Exploration Strategy Advisory Group organized by NASA, a study team was formed in the fall of 1986 to develop a preliminary definition of a flight-separable, cooperative mission. The selected concept assumes that the U.S. would undertake the rover mission with its sample collection operations and our international partner would return the samples to Earth. Although the inverse of these roles is also possible, this study report focuses on the rover functions of MRSR because rover operations have not

  20. Preliminary study of a scale measuring depression and somatic symptoms.

    PubMed

    Hung, Ching-I; Weng, Li-Jen; Su, Yi-Jen; Liu, Chia-Yih

    2006-10-01

    This description concerns the development of a scale measuring depression and somatic symptoms and the selection of its items for a Taiwanese sample. 102 Taiwanese outpatients (28 men, 74 women) with major depressive disorder completed a 44-item preliminary scale. All had experienced a major depressive episode but had not been treated by antidepressants within the prior two weeks. The Hamilton Depression Rating Scale was administered to evaluate the validity of the Depression and Somatic Symptoms Scale (DSSS). Items, 12 for the Depression Subscale and 10 for the Somatic Subscale, were selected for the Depression and Somatic Symptoms Scale according to their frequency and their association with rated severity of depression and clinical practices. The mean Hamilton Depression score was 23.9 (SD = 5.2) versus 38.4 (SD = 11.3) for the total DSSS; means for the Depression subscale were 23.5 +/- 6.0 and the Somatic subscale 14.9 +/- 6.8. Cronbach alpha was .88 for the total DSSS, .78 for the Depression subscale, and .86 for the Somatic subscale. The Pearson correlation coefficient for the two scales was .59 (p <.01). The new scale had adequate internal consistency reliability and convergent validity. Much study is required to assess its structure, item characteristics, and in judging its applicability and limitations, and sensitivity to cultural differences in clinical settings. PMID:17153806

  1. ECG response of koalas to tourists proximity: a preliminary study.

    PubMed

    Ropert-Coudert, Yan; Brooks, Lisa; Yamamoto, Maki; Kato, Akiko

    2009-01-01

    Koalas operate on a tight energy budget and, thus, may not always display behavioral avoidance reaction when placed in a stressful condition. We investigated the physiological response of captive koalas Phascolarctos cinereus in a conservation centre to the presence of tourists walking through their habitat. We compared, using animal-attached data-recorders, the electrocardiogram activity of female koalas in contact with tourists and in a human-free area. One of the koalas in the tourist zone presented elevated heart rate values and variability throughout the recording period. The remaining female in the exhibit area showed a higher field resting heart rates during the daytime than that in the isolated area. In the evening, heart rate profiles changed drastically and both the koalas in the exhibit and in the tourist-free zones displayed similar field resting heart rates, which were lower than those during the day. In parallel, the autonomic nervous systems of these two individuals evolved from sympathetic-dominant during the day to parasympathetic-dominant in the evening. Our results report ECG of free-living koalas for the first time. Although they are preliminary due to the difficulty of having sufficient samples of animals of the same sex and age, our results stress out the importance of studies investigating the physiological reaction of animals to tourists. PMID:19823679

  2. Relationship between electrohysterogram and internal uterine pressure: a preliminary study.

    PubMed

    Rabotti, C; Mischi, M; van Laar, J O E H; Aelen, P; Oei, S G; Bergmans, J W M

    2006-01-01

    Electrohysterography (EHG) is a promising technique for monitoring the uterine activity, based on electrical recordings on the abdominal surface. However, a quantitative estimation of the internal uterine pressure (IUP) by means of EHG is not available for clinical practice. In this paper we present a preliminary study on the estimation of the mechanical uterine activity from abdominal EHG measurements. For the EHG analysis we use two different Time Frequency Distributions (TFD): the spectrogram and the Wigner-Ville Distribution. We assume the EHG to be the sum of frequency modulated signals. Based on this assumption, the IUP is estimated from the unnormalized first moment of the TFD. Eventually, a third order polynomial model is applied to the estimated IUP in order to improve the estimate accuracy. A recent method for detection of uterine contraction by EHG is employed for comparison of the performance. The algorithms were tested on two patient recordings. The results were compared with a reference IUP which is simultaneously measured by an intrauterine catheter. The IUP estimated by our method showed a correlation coefficient with the reference IUP (R=0.93) higher than that achieved by the comparison method (R=0.85). Therefore the proposed method may be considered as a promising clinical technique for accurate non invasive IUP measurements. PMID:17946058

  3. The treatment of nonstreptococcal pharyngitis with erythromycin: a preliminary study.

    PubMed

    Marlow, R A; Torrez, A J; Haxby, D

    1989-01-01

    This preliminary study evaluated the effectiveness of enteric-coated erythromycin in the treatment of adults with nonstreptococcal pharyngitis. Twenty-six patients, aged 12 or older, with nonstreptococcal pharyngitis were randomly assigned in a double-blind fashion to receive either enteric-coated erythromycin or placebo for 10 days. Each day the patients rated the soreness of their throats and how sick they felt. The use of erythromycin appeared to decrease the median number of days for the feeling of sickness to improve (two days versus four days, P less than .01) as well as to decrease the median number of days for the feeling of sickness to resolve (three-and-a-half days versus five days, P less than .05). This apparent improvement in sickness occurred even though there was no significant decrease in the soreness of the throat in patients treated with erythromycin compared to those patients treated with placebo. Treatment with enteric-coated erythromycin appeared to shorten the time until improvement in this group of adults with nonstreptococcal pharyngitis. PMID:2612797

  4. Predicting use of hearing protection: a preliminary study.

    PubMed

    Lusk, S L; Kelemen, M J

    1993-09-01

    The National Institute of Occupational Safety and Health targeted noise-induced hearing loss as one of the top 10 occupational hazards. Research has been directed toward reducing noise exposure rather than identifying the factors associated with workers' decision consistently to use hearing protection. The long-term goal of this program of research is to develop a causal model explaining workers' use of hearing protection to guide development of nursing interventions. This study was a preliminary one to prepare for testing Pender's health-promotion model (HPM) as a causal model. Ninety-eight skilled tradesmen completed written questionnaires at their work site. Although 98% indicated they were supposed to wear protection, their reported use averaged 50.3% of the time. Reported use significantly and positively correlated with workers' perceptions of the benefits and self-efficacy of use, value of outcomes regarding keeping out noise and increased well-being, and health-promoting behaviors in the areas of self-actualization and stress management. Perceptions of barriers of use were significantly and negatively related to use. In regression analyses of use of hearing protection on components of the HPM and dimensions of health behavior and lifestyle, one component of the HPM (benefits) and two dimensions of health behavior and lifestyle (self-actualization and interpersonal support) significantly predicted use, accounting for 24% of the variance in use of protection. Knowledge of the predictors of hearing protection use will ultimately aid nurses in implementing interventions, increasing use, and decreasing hearing losses. PMID:8234157

  5. A Preliminary Study of Sex Differences in Emotional Experience.

    PubMed

    Reyes-Aguilar, Azalea; Barrios, Fernando A

    2016-04-01

    Evolutionary approaches have proposed that women possess an advantage over men in emotional functioning to promote attachment for child-rearing. Likewise, sex differences have been reported in traits such as personality and empathy, traits that likely modulate emotional processing. In this preliminary study, sex differences in emotional processing were analyzed, including empathy as a social emotion and personality traits, as well as whether there exist relationships between those measures. Young volunteers (N = 105) indicated the emotional valence, activation, and dominance that they experience in situations categorized as emotionally positive, negative, or neutral. The results of comparison between sexes supported the approach that women showed more sensitivity to high activation and dominance for positive emotions and empathy, and men were more sensitive to negative situations. Correlation analysis showed only one positive relationship between scores of Self-transcendence, a subscale of Temperament and Character Inventory, with activation scores of neutral situations, but not with emotionally charged situations, perhaps because emotions are context-dependent processes while personality traits are considered context-independent descriptions of habits. These findings should be replicated to enrich knowledge about problems in emotional processing. PMID:27154367

  6. A Preliminary Study of Functional Connectivity in Comorbid Adolescent Depression

    PubMed Central

    Cullen, Kathryn R.; Gee, Dylan G.; Klimes-Dougan, Bonnie; Gabbay, Vilma; Hulvershorn, Leslie; Mueller, Bryon A.; Camchong, Jazmin; Bell, Christopher J.; Houri, Alaa; Kumra, Sanjiv; Lim, Kelvin O.; Castellanos, F. Xavier; Milham, Michael P.

    2009-01-01

    Major Depressive Disorder (MDD) begins frequently in adolescence and is associated with severe outcomes, but the developmental neurobiology of MDD is not well understood. Research in adults has implicated fronto-limbic neural networks in the pathophysiology of MDD, particularly in relation to the subgenual anterior cingulate cortex (ACC). Developmental changes in brain networks during adolescence highlight the need to examine MDD-related circuitry in teens separately from adults. Using resting state functional magnetic resonance imaging (fMRI), this study examined functional connectivity in adolescents with MDD (n=12) and healthy adolescents (n=14). Seed-based connectivity analysis revealed that adolescents with MDD have decreased functional connectivity in a subgenual ACC-based neural network that includes the supragenual ACC (BA 32), the right medial frontal cortex (BA 10), the left inferior (BA 47) and superior frontal cortex (BA 22), superior temporal gyrus (BA 22), and the insular cortex (BA 13). These preliminary data suggest that MDD in adolescence is associated with abnormal connectivity within neural circuits that mediate emotion processing. Future research in larger, un-medicated samples will be necessary to confirm this finding. We conclude that hypothesis-driven, seed-based analyses of resting state fMRI data hold promise for advancing our current understanding of abnormal development of neural circuitry in adolescents with MDD. PMID:19446602

  7. Preliminary design studies on a nuclear seawater desalination system

    SciTech Connect

    Wibisono, A. F.; Jung, Y. H.; Choi, J.; Kim, H. S.; Lee, J. I.; Jeong, Y. H.; No, H. C.

    2012-07-01

    Seawater desalination is one of the most promising technologies to provide fresh water especially in the arid region. The most used technology in seawater desalination are thermal desalination (MSF and MED) and membrane desalination (RO). Some developments have been done in the area of coupling the desalination plant with a nuclear reactor to reduce the cost of energy required in thermal desalination. The coupling a nuclear reactor to a desalination plant can be done either by using the co-generation or by using dedicated heat from a nuclear system. The comparison of the co-generation nuclear reactor with desalination plant, dedicated nuclear heat system, and fossil fueled system will be discussed in this paper using economical assessment with IAEA DEEP software. A newly designed nuclear system dedicated for the seawater desalination will also be suggested by KAIST (Korea Advanced Inst. of Science and Technology) research team and described in detail within this paper. The suggested reactor system is using gas cooled type reactor and in this preliminary study the scope of design will be limited to comparison of two cases in different operating temperature ranges. (authors)

  8. Textual appropriation in engineering master's theses: a preliminary study.

    PubMed

    Eckel, Edward J

    2011-09-01

    In the thesis literature review, an engineering graduate student is expected to place original research in the context of previous work by other researchers. However, for some students, particularly those for whom English is a second language, the literature review may be a mixture of original writing and verbatim source text appropriated without quotations. Such problematic use of source material leaves students vulnerable to an accusation of plagiarism, which carries severe consequences. Is such textual appropriation common in engineering master's writing? Furthermore, what, if anything, can be concluded when two texts have been found to have textual material in common? Do existing definitions of plagiarism provide a sufficient framework for determining if an instance of copying is transgressive or not? In a preliminary attempt to answer these questions, text strings from a random sample of 100 engineering master's theses from the ProQuest Dissertations and Theses database were searched for appropriated verbatim source text using the Google search engine. The results suggest that textual borrowing may indeed be a common feature of the master's engineering literature review, raising questions about the ability of graduate students to synthesize the literature. The study also illustrates the difficulties of making a determination of plagiarism based on simple textual similarity. A context-specific approach is recommended when dealing with any instance of apparent copying. PMID:20521174

  9. Bio-Contamination Control for Spacesuit Garments - A Preliminary Study

    NASA Technical Reports Server (NTRS)

    Rhodes, Richard; Korona, Adam; Orndoff, Evelyn; Ott, Mark; Poritz, Darwin

    2010-01-01

    This paper outlines a preliminary study to review, test, and improve upon the current state of spacesuit bio-contamination control. The study includes an evaluation of current and advanced suit materials, ground and on-orbit cleaning methods, and microbial test and analysis methods. The first aspect of this study was to identify potential anti-microbial textiles and cleaning agents, and to review current microbial test methods. The anti-microbial cleaning agent and textile market survey included a review of current commercial-off-the-shelf (COTS) products that could potentially be used as future space flight hardware. This review included replacements for any of the softgood layers that may become contaminated during an extravehicular activity (EVA), including the pressure bladder, liquid cooling garment, and ancillary comfort undergarment. After a series of COTS anti-microbial textiles and clean ing agents were identified, a series of four tests were conducted: (1) a stacked configuration test that was conducted in order to review how bio-contamination would propagate through the various suit layers, (2) a individual materials test that evaluated how well each softgood layer either promoted or repressed growth, (3) a cleaning agent test that evaluated the efficacy on each of the baseline bladders, and (4) an evaluation of various COTS anti-microbial textiles. All antimicrobial COTS materials tested appeared to control bacteria colony forming unit (CFU) growth better than the Thermal Comfort Undergarment (TCU) and ACES Liquid Cooling Garment (LCG)/EMU Liquid Cooling Ventilation Garment (LCVG) materials currently in use. However, a comparison of fungi CFU growth in COTS to current suit materials appeared to vary per material. All cleaning agents tested in this study appeared to inhibit the level of bacteria and fungi growth to acceptable levels for short duration tests. While several trends can be obtained from the current analysis, a series of test improvements are

  10. Progress in preliminary studies at Ottana Solar Facility

    NASA Astrophysics Data System (ADS)

    Demontis, V.; Camerada, M.; Cau, G.; Cocco, D.; Damiano, A.; Melis, T.; Musio, M.

    2016-05-01

    The fast increasing share of distributed generation from non-programmable renewable energy sources, such as the strong penetration of photovoltaic technology in the distribution networks, has generated several problems for the management and security of the whole power grid. In order to meet the challenge of a significant share of solar energy in the electricity mix, several actions aimed at increasing the grid flexibility and its hosting capacity, as well as at improving the generation programmability, need to be investigated. This paper focuses on the ongoing preliminary studies at the Ottana Solar Facility, a new experimental power plant located in Sardinia (Italy) currently under construction, which will offer the possibility to progress in the study of solar plants integration in the power grid. The facility integrates a concentrating solar power (CSP) plant, including a thermal energy storage system and an organic Rankine cycle (ORC) unit, with a concentrating photovoltaic (CPV) plant and an electrical energy storage system. The facility has the main goal to assess in real operating conditions the small scale concentrating solar power technology and to study the integration of the two technologies and the storage systems to produce programmable and controllable power profiles. A model for the CSP plant yield was developed to assess different operational strategies that significantly influence the plant yearly yield and its global economic effectiveness. In particular, precise assumptions for the ORC module start-up operation behavior, based on discussions with the manufacturers and technical datasheets, will be described. Finally, the results of the analysis of the: "solar driven", "weather forecasts" and "combined storage state of charge (SOC)/ weather forecasts" operational strategies will be presented.

  11. A preliminary magnetic study of Sawa lake sediments, Southern Iraq

    NASA Astrophysics Data System (ADS)

    Ameen, Nawrass

    2016-04-01

    A preliminary magnetic study combined with chemical analyses was carried out in Sawa Lake in Al-Muthanna province, southern Iraq, about 22 km south west of Samawa city (31°18'48.80"N, 45°0'25.25"E). The lake is about 4.74 km length, 1.75 km width and 5.5 m height, it is surrounded by a salt rim which is higher than the lake water by about 2.8 m and sea water by about 18.5 m (Naqash et al., 1977 in Hassan, 2007). The lake is an elongated closed basin with no surface water available to it, it may be fed by groundwater of the Euphrates and Dammam aquifers through system of joints and cracks. This study aims to investigate the concentrations of selected heavy metals as pollutants and magnetic susceptibility (MS) and other magnetic properties of sediment samples from fifty sites collected from the bottom of the lake, the study area lies in an industrial area. The results show spatial variations of MS with mean value of about 4.58 x 10‑8 m3 kg‑1. Scanning electron microscopy and magnetic mineralogy parameters indicate the dominance of soft magnetic phase like magnetite and presence of hard magnetic phase like hematite. Spatial variations of MS combined with the concentrations of heavy metals suggests the efficiency of magnetic methods as effective, inexpensive and non-time consuming method to outlining the heavy metal pollution. References: Hassan W.F., 2007. The Physio-chemical characteristic of Sawa lake water in Samawa city-Iraq. Marine Mesopotamica, 22(2), 167-179.

  12. Nevada potential repository preliminary transportation strategy: Study 1

    SciTech Connect

    None,

    1995-04-01

    Limited feasible options exist when considering the shipment of spent nuclear fuel and high-level radioactive waste. These options are rail or truck; because of the weight associated with transportation casks (68.0 to 113.4 tonnes/75 to 125 tons), heavy-haul trucks are also considered. Yucca Mountain currently lacks rail service or an existing right-of-way for rail; it also lacks a dedicated highway suitable for heavy-haul trucks. Approximately 11,230 shipments by rail are planned from waste producer sites to Nevada, with an additional 1,041 shipments by legal-weight truck from four reactor sites not capable of upgrading for rail shipment. This study identifies the reasonable alternatives for waste transport to the potential repository site, describes the evaluation process performed to identify those alternatives, and discusses the reasons for elimination of transportation routes deemed to be not reasonable. The study concluded that heavy haul truck transportation is feasible-cost is very favorable when compared to rail-but route restrictions must be further evaluated. In addition to restrictions due to seasonal weather conditions, specific routes have additional restrictions, including no travel on holidays or weekends, and travel during daylight hours only. Further restrictions will be imposed by the U.S. Department of Transportation based on routing of radioactive materials by highway. Operation and maintenance costs for heavy-haul over a 24-year period, based on preliminary information, were calculated on an estimated operational cost of $15,000 per trip, with an estimated 468 trips per year average (11,230 total trips), for an estimated cost of $171 million to $173 million, depending on the route used. Because the initial costs and the total system life cycle costs of heavy-haul are approximately 50 percent lower than the lowest rail cost, this option will continue to be evaluated.

  13. A Preliminary Feasibility Study On Seismic Monitoring Of Polymer Flooding

    NASA Astrophysics Data System (ADS)

    Nguyen, P. K.; Park, C.; Lim, B.; Nam, M.

    2012-12-01

    Polymer flooding using water with soluble polymers is an enhanced oil recovery technique, which intends to maximize oil-recovery sweep efficiency by minimizing fingering effects and as a result creating a smooth flood front; polymer flooding decreases the flow rates within high permeability zone while enhances those of lower permeabilities. Understanding of fluid fronts and saturations is critical to not only optimizing polymer flooding but also monitoring the efficiency. Polymer flooding monitoring can be made in single well scale with high-resolution wireline logging, in inter-well scale with tomography, and in reservoir scale with surface survey. For reservoir scale monitoring, this study makes a preliminary feasibility study based on constructing rock physics models (RPMs), which can bridge variations in reservoir parameters to the changes in seismic responses. For constructing RPMs, we change reservoir parameters with consideration of polymer flooding to a reservoir. Time-lapse seismic data for corresponding RPMs are simulated using a time-domain staggered-finite-difference modeling with implementation of a boundary condition of conventional perfect match layer. Analysis on time-lapse seismic data with respect to the changes in fluid front and saturation can give an insight on feasibility of surface seismic survey to polymer flooding. Acknowledgements: This work was supported by the Energy Efficiency & Resources of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No. 2012T100201588). Myung Jin Nam was partially supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MEST) (No. 2011-0014684).

  14. Preliminary study of the CRRES magnetospheric barium releases

    NASA Technical Reports Server (NTRS)

    Huba, J. D.; Bernhardt, P. A.; Lyon, J. G.

    1992-01-01

    Preliminary theoretical and computational analyses of the Combined Release and Radiation Effects Satellite (CRRES) magnetospheric barium releases are presented. The focus of the studies is on the evolution of the diamagnetic cavity which is formed by the barium ions as they expand outward, and on the structuring of the density and magnetic field during the expansion phase of the releases. Two sets of simulation studies are discussed. The first set is based upon a 2D ideal MHD code and provides estimates of the time and length scales associated with the formation and collapse of the diamagnetic cavity. The second set uses a nonideal MHD code; specifically, the Hall term is included. This additional term is critical to the dynamics of sub-Alfvenic plasma expansions, such as the CRRES barium releases, because it leads to instability of the expanding plasma. Detailed simulations of the G4 and G10 releases were performed. In both cases the expanding plasma rapidly structured: the G4 release structured at time t less than about 3 s and developed scale sizes of about 1-2 km, while the G10 release structured at time t less than about 22 s and developed scale sizes of about 10-15 km. It is also found that the diamagnetic cavity size is reduced from those obtained from the ideal MHD results because of the structure. On the other hand, the structuring allows the formation of plasma blobs which appear to free stream across the magnetic field; thus, the barium plasma can propagate to larger distances traverse to the magnetic field than the case where no structuring occurs. Finally, a new normal mode of the system was discovered which may be excited at the leading edge of the expanding barium plasma.

  15. TYPE Ia SUPERNOVA LIGHT-CURVE INFERENCE: HIERARCHICAL BAYESIAN ANALYSIS IN THE NEAR-INFRARED

    SciTech Connect

    Mandel, Kaisey S.; Friedman, Andrew S.; Kirshner, Robert P.; Wood-Vasey, W. Michael

    2009-10-10

    We present a comprehensive statistical analysis of the properties of Type Ia supernova (SN Ia) light curves in the near-infrared using recent data from Peters Automated InfraRed Imaging TELescope and the literature. We construct a hierarchical Bayesian framework, incorporating several uncertainties including photometric error, peculiar velocities, dust extinction, and intrinsic variations, for principled and coherent statistical inference. SN Ia light-curve inferences are drawn from the global posterior probability of parameters describing both individual supernovae and the population conditioned on the entire SN Ia NIR data set. The logical structure of the hierarchical model is represented by a directed acyclic graph. Fully Bayesian analysis of the model and data is enabled by an efficient Markov Chain Monte Carlo algorithm exploiting the conditional probabilistic structure using Gibbs sampling. We apply this framework to the JHK{sub s} SN Ia light-curve data. A new light-curve model captures the observed J-band light-curve shape variations. The marginal intrinsic variances in peak absolute magnitudes are sigma(M{sub J}) = 0.17 +- 0.03, sigma(M{sub H}) = 0.11 +- 0.03, and sigma(M{sub Ks}) = 0.19 +- 0.04. We describe the first quantitative evidence for correlations between the NIR absolute magnitudes and J-band light-curve shapes, and demonstrate their utility for distance estimation. The average residual in the Hubble diagram for the training set SNe at cz > 2000kms{sup -1} is 0.10 mag. The new application of bootstrap cross-validation to SN Ia light-curve inference tests the sensitivity of the statistical model fit to the finite sample and estimates the prediction error at 0.15 mag. These results demonstrate that SN Ia NIR light curves are as effective as corrected optical light curves, and, because they are less vulnerable to dust absorption, they have great potential as precise and accurate cosmological distance indicators.

  16. Two-Pole Caustic Model for High-Energy Lightcurves of Pulsars

    NASA Technical Reports Server (NTRS)

    Dyks, J.; Rudak, B.

    2003-01-01

    We present a new model of high-energy lightcurves from rotation powered pulsars. The key ingredient of the model is the gap region (i.e. the region where particle acceleration is taking place and high-energy photons originate) which satisfies the following assumptions: i) the gap region extends from each polar cap to the light cylinder; ii) the gap is thin and confined to the surface of last open magnetic-field lines; iii) photon emissivity is uniform within the gap region. The model lightcurves are dominated by strong peaks (either double or single) of caustic origin. Unlike in other pulsar models with caustic effects, the double peaks arise due to crossing two caustics, each of which is associated with a different magnetic pole. The generic features of the lightcurves are consistent with the observed characteristics of pulsar lightcurves: 1) the most natural (in terms of probability) shape consists of two peaks (separated by 0.4 to 0.5 in phase for large viewing angles); 2) the peaks possess well developed wings; 3) there is a bridge (inter-peak) emission component; 4) there is a non-vanishing off-pulse emission level; 5) the radio pulse occurs before the leading high-energy peak. The model is well suited for four gamma-ray pulsars - Crab, Vela, Geminga and B1951+32 - with double-peak lightcurves exhibiting the peak separation of 0.4 to 0.5 in phase. Hereby, we apply the model to the Vela pulsar. Moreover, we indicate the limitation of the model in accurate reproducing of the lightcurves with single pulses and narrowly separated (about 0.2 in phase) pulse peaks. We also discuss the optical polarization properties for the Crab pulsar in the context of the two-pole caustic model.

  17. Adsorption of Roxarsone onto Drinking Water Treatment Residuals: Preliminary Studies

    NASA Astrophysics Data System (ADS)

    Salazar, J.; Sarkar, D.; Datta, R.; Sharma, S.

    2006-05-01

    above parameters were varied one at a time to study their effects on roxarsone adsorption. Desorption studies were carried out using 125 mg/L phosphorous at predetermined interval of time. In addition to analyzing for total As by an ICP-MS, aqueous speciation of As was performed using a coupled HPLC-ICP-MS system. Preliminary studies show significant roxarsone adsorption capacity of the WTRs.

  18. Preliminary study of volcano monitoring using geochemical composition of lichen

    NASA Astrophysics Data System (ADS)

    KUAN, S.

    2012-12-01

    Taipei City, the capital of Taiwan, is bounded with Tatun Volcano Group (TVG), which is not active since 200 ka. However, some evidences indicate that the latest explosion of volcanic ash was dated to 5-6 ka as well as TVG is so close to metropolis. The monitoring on TVG is crucial for crisis management. For monitoring TVG, changes of geochemical signal in some volcanic gases and hot springs are currently assessed by monthly sampling. The geochemistry of volcanic gas and hot spring represents a short-term condition on sampling time and is highly controlled by temperature and precipitation on the surface. A long-term average geochemistry will be very helpful to be compared with the results of volcanic gas and hot spring. A bioindicator not only has the ability to store geochemical compositions in their tissues but also has a wide geographical distribution. It is very suitable in this kind of study and lichen is one of the best bioindicators mainly because lichens grow slowly and have a large-scale dependence upon the environment for their nutrition, In TVG, the high SO2 content in the atmosphere results in the absence of fruticose lichen. On the contrary, crustos lichen is the most common species in the study area. For the preliminary analysis, one fruticose, four foliose and four crustos lichens were collected around the major emission centers of volcanic gas. According to the results of ICP-MS analysis, the abundances of heavy metals are generally in the order of Zn, Fe, Mn, Cu, Cr, Pb, Cd, Ni, V, Co and U. Factor analysis (FA) demonstrates that most of the metals show very high loadings in the first factor. This means that the fractionation of metals among different lichen species is minor and the geochemical compositions of lichen are possibly controlled by the same source (atmosphere). The second factor of FA includes Mn, Sr and Ba, which share the same oxidation state of +2 in acidic environment. This factor can describe the variation of Mn, Sr and Ba in the

  19. Asteroid Lightcurve Analysis at Riverland Dingo Observatory (RDO): 501 Urhixidur, 1897 Hind, 1928 Summa, 6261 Chione, and (68216) 2001 CV 26.

    NASA Astrophysics Data System (ADS)

    Hills, Kevin

    2013-01-01

    Lightcurves for five asteroids selected from the Collaborative Asteroid Lightcurve Link (CALL) were obtained at Riverland Dingo Observatory (RDO) from 2012 July-September: 501 Urhixidur, 1897 Hind, 1928 Summa, 6261 Chione, and (68216) 2001 CV26.

  20. Infrared laser sealing of porcine tissues: preliminary in vivo studies

    NASA Astrophysics Data System (ADS)

    Cilip, Christopher M.; Hutchens, Thomas C.; Kerr, Duane; Latimer, Cassandra; Rosenbury, Sarah B.; Giglio, Nicholas C.; Schweinsberger, Gino R.; Perkins, William C.; Wilson, Christopher R.; Ward, Arlen; Nau, William H.; Fried, Nathaniel M.

    2015-02-01

    We are exploring infrared (IR) lasers as an alternative energy modality to radiofrequency (RF) and ultrasonic (US) devices intended to provide rapid surgical hemostasis with minimal collateral zones of thermal damage and tissue necrosis. Previously, a 1470-nm IR laser sealed and cut ex vivo porcine renal arteries of 1-8 mm in 2 s, yielding burst pressures < 1200 mmHg (compared to normal systolic blood pressure of 120 mmHg) and thermal coagulation zones < 3 mm (including the seal). This preliminary study describes in vivo testing of a laser probe in a porcine model. A prototype, fiber optic based handheld probe with vessel/tissue clasping mechanism was tested on blood vessels < 6 mm diameter using incident 1470-nm laser power of 35 W for 1-5 s. The probe was evaluated for hemostasis after sealing isolated and bundled vasculature of abdomen and hind leg, as well as liver and lung parenchyma. Sealed vessel samples were collected for histological analysis of lateral thermal damage. Hemostasis was achieved in 57 of 73 seals (78%). The probe consistently sealed vasculature in small bowel mesentery, mesometrium, and gastro splenic and epiploic regions. Seal performance was less consistent on hind leg vasculature including saphenous arteries and bundles and femoral and iliac arteries. Collagen denaturation averaged 1.6 mm in 8 samples excised for histologic examination. A handheld laser probe sealed porcine vessels in vivo. With further improvements in probe design and laser parameter optimization, IR lasers may provide an alternative to RF and US vessel sealing devices.

  1. Preliminary results of spectral reflectance studies of tycho crater

    NASA Technical Reports Server (NTRS)

    Hawke, B. R.; Coombs, C. R.; Lucey, P. G.; Bell, J. F.; Jaumann, R.; Neukum, G.; Pieters, Carle M.

    1987-01-01

    The preliminary analysis and interpretation of near infrared spectra obtained for both the interior and exterior deposits associated with the Tycho crater is presented. Specific objectives were: (1) to determine the composition and stratigraphy of the highland crust in the Tycho target site; (2) to determine the likely composition of the primary ejecta which may be present in ray deposits; (3) to investigate the nature of spectral units defined in previous studies; (4) to further investigate the nature and origin of both the bright and dark haloes around the rim crest; and (5) to compare the compositions determined for the Tycho units with those of the Aristarchus crater as well as typical highland deposits. The spectra obtained for the interior areas exhibit similar spectral features. These include relatively strong 1 micron absorption bands whose minima are centered between 0.97 and 0.99 microns and shallow to intermediate continuum slopes. The spectra generally exhibit indications of a 1.3 micron feature consistent with the presence of Fe(2+) bearing plagioclase feldspar. The strong 1 micron absorption features indicate a dominant high Ca clinopyroxene component. Results obtained from the ejecta deposits show that the spectrum of the inner, bright halo is almost identical with those obtained for interior units. The spectrum of the dark halo exhibits a wide, relatively shallow absorption feature centered at 1.01 microns, a 1.3 micron absorption, and a steep continuum slope. This spectrum is interpreted as indicating the presence of pyroxene, Fe-bearing feldspar, and a significant component of Fe-bearing impact melt glass. Finally, the spectra of spots inside Tycho show similarity with certain spectra for Aristarchus. However, the suite of spectra obtained for Tycho exhibits a different trend in terms of band center versus width.

  2. Asteroid Lightcurve Analysis at Riverland Dingo Observatory (RDO): 185 Eunike, (17252) 2000 GJ127, and (152858) 1999 XN35

    NASA Astrophysics Data System (ADS)

    Hills, Kevin

    2013-04-01

    Lightcurves for three asteroids selected from the Collaborative Asteroid Lightcurve Link (CALL; Warner 2011) were obtained at Riverland Dingo Observatory (RDO) in the period October 13 through December 5, 2012: 185 Eunike, (17252) 2000 GJ127, and (152858) 1999 XN35.

  3. A Preliminary Outcome Study of Response Ability Pathways Training

    ERIC Educational Resources Information Center

    Forthun, Larry F.; McCombie, Jeff W.

    2007-01-01

    Approximately 68 classroom teachers participated in a preliminary evaluation of Response Ability Pathways (RAP), a reclaiming training course for adults who work with children and youth. RAP offers basic training in the Circle of Courage Model and provides participants with general strategies for assisting youth who are experiencing challenges.…

  4. Preliminary design study of astronomical detector cooling system

    NASA Technical Reports Server (NTRS)

    Norman, R. H.

    1976-01-01

    The preliminary design of an astronomical detector cooling system for possible use in the NASA C-141 Airborne Infrared Observatory is presented. The system consists of the following elements: supercritical helium tank, Joule-Thomson supply gas conditioner, Joule-Thomson expander (JTX), optical cavity dewar, optical cavity temperature controller, adjustable J-T discharge gas pressure controller, and vacuum pump.

  5. Technology User Groups and Early Childhood Education: A Preliminary Study

    ERIC Educational Resources Information Center

    Parette, Howard P.; Hourcade, Jack J.; Blum, Craig; Watts, Emily H.; Stoner, Julia B.; Wojcik, Brian W.; Chrismore, Shannon B.

    2013-01-01

    This article presents a preliminary examination of the potential of Technology User Groups as a professional development venue for early childhood education professionals in developing operational and functional competence in using hardware and software components of a Technology toolkit. Technology user groups are composed of varying numbers of…

  6. The X-ray Lightcurve of Eta Carinae, 1996-2014

    NASA Astrophysics Data System (ADS)

    Corcoran, Michael F.; Hamaguchi, Kenji; Liburd, Jamar; Gull, Theodore R.; Madura, Thomas; Teodoro, Mairan; Moffat, Anthony F. J.; Richardson, Noel; Russell, Christopher Michael Post; Pollock, A.; Owocki, Stanley P.

    2015-01-01

    Eta Carinae is the nearest example of a supermassive, superluminous, unstable star. Mass loss from the system is important in shaping its circumstellar medium and in determining the ultimate fate of the star. Eta Car loses mass via a dense, slow stellar wind and possesses one of the largest mass loss rates known. It is prone to episodes of extreme mass ejection via eruptions from some as-yet unspecified cause; the best examples of this are the large-scale eruptions which occurred in the mid-19th century, and then again about 50 years later. Eta Car is a colliding wind binary in which strong variations in X-ray emission and in other wavebands are driven by the violent collision of the wind of Eta Car and the fast, less dense wind of an otherwise hidden companion star. X-ray variations are the simplest diagnostic we have to study the wind-wind collision and allow us to measure the state of the stellar mass loss from both stars. We present the X-ray lightcurve over the last 20 years from monitoring observations with the Rossi X-ray Timing Explorer and the X-ray Telescope on the Swift satellite, and compare and contrast the behavior of the X-ray emission from the system over that timespan, including surprising variations during the 2014 X-ray minimum.

  7. IMAGING STARSPOT EVOLUTION ON KEPLER TARGET KIC 5110407 USING LIGHT-CURVE INVERSION

    SciTech Connect

    Roettenbacher, Rachael M.; Monnier, John D.; Harmon, Robert O.; Barclay, Thomas; Still, Martin

    2013-04-10

    The Kepler target KIC 5110407, a K-type star, shows strong quasi-periodic light curve fluctuations likely arising from the formation and decay of spots on the stellar surface rotating with a period of 3.4693 days. Using an established light-curve inversion algorithm, we study the evolution of the surface features based on Kepler space telescope light curves over a period of two years (with a gap of .25 years). At virtually all epochs, we detect at least one large spot group on the surface causing a 1%-10% flux modulation in the Kepler passband. By identifying and tracking spot groups over a range of inferred latitudes, we measured the surface differential rotation to be much smaller than that found for the Sun. We also searched for a correlation between the 17 stellar flares that occurred during our observations and the orientation of the dominant surface spot at the time of each flare. No statistically significant correlation was found except perhaps for the very brightest flares, suggesting that most flares are associated with regions devoid of spots or spots too small to be clearly discerned using our reconstruction technique. While we may see hints of long-term changes in the spot characteristics and flare statistics within our current data set, a longer baseline of observation will be needed to detect the existence of a magnetic cycle in KIC 5110407.

  8. Preliminary design studies for the DESCARTES and CIDER codes

    SciTech Connect

    Eslinger, P.W.; Miley, T.B.; Ouderkirk, S.J.; Nichols, W.E.

    1992-12-01

    The Hanford Environmental Dose Reconstruction (HEDR) project is developing several computer codes to model the release and transport of radionuclides into the environment. This preliminary design addresses two of these codes: Dynamic Estimates of Concentrations and Radionuclides in Terrestrial Environments (DESCARTES) and Calculation of Individual Doses from Environmental Radionuclides (CIDER). The DESCARTES code will be used to estimate the concentration of radionuclides in environmental pathways, given the output of the air transport code HATCHET. The CIDER code will use information provided by DESCARTES to estimate the dose received by an individual. This document reports on preliminary design work performed by the code development team to determine if the requirements could be met for Descartes and CIDER. The document contains three major sections: (i) a data flow diagram and discussion for DESCARTES, (ii) a data flow diagram and discussion for CIDER, and (iii) a series of brief statements regarding the design approach required to address each code requirement.

  9. Preliminary experimental study of a carbon fiber array cathode

    NASA Astrophysics Data System (ADS)

    Li, An-kun; Fan, Yu-wei

    2016-08-01

    The preliminary experimental results of a carbon fiber array cathode for the magnetically insulated transmission line oscillator (MILO) operations are reported. When the diode voltage and diode current were 480 kV and 44 kA, respectively, high-power microwaves with a peak power of about 3 GW and a pulse duration of about 60 ns were obtained in a MILO device with the carbon fiber array cathode. The preliminary experimental results show that the shot-to-shot reproducibility of the diode current and the microwave power is stable until 700 shots. No obvious damage or deterioration can be observed in the carbon fiber surface morphology after 700 shots. Moreover, the cathode performance has no observable deterioration after 700 shots. In conclusion, the maintain-free lifetime of the carbon fiber array cathode is more than 700 shots. In this way, this carbon fiber array cathode offers a potential replacement for the existing velvet cathode.

  10. (D, L) polylactide microspheres as embolic agent. A preliminary study.

    PubMed

    Flandroy, P; Grandfils, C; Collignon, J; Thibaut, A; Nihant, N; Barbette, S; Jerome, R; Teyssie, P

    1990-01-01

    Owing to their shape, accurately calibrated microspheres appear to be very suitable material for distal embolization. Moreover, the biocompatible (D, L) polyactide (PLA) microspheres possess two other valuable advantages: easy adjustment of their biodegradation rate, and incorporation of chemotherapeutic agents during their production. The authors describe the preparation of these (D, L) PLA microspheres and their clinical applications as a preliminary step to arterial chemoembolization. PMID:2234391

  11. Thermoluminescent Dosimetry: A Preliminary Study for microCT Applications

    SciTech Connect

    Montano Garcia, C.; Rodriguez-Villafuerte, M.; Martinez-Davalos, A.; Brandan, M. E.; Ruiz-Trejo, C.

    2006-09-08

    Preliminary measurements for microCT dosimetry are reported in this work, using TLD-100 crystals (1x1x1 mm3) within a solid water phantom specially designed with approximate dimensions of a mouse. A dose dependence as a function of radial distance and position along the axis of the phantom was found. Because of the smaller doses used in this work we can say that it is feasible to perform dosimetry measurements with high accuracy using TLD-100 microcubes.

  12. Preliminary Fatigue Studies on Aluminum Alloy Aircraft Engines

    NASA Technical Reports Server (NTRS)

    1938-01-01

    Preliminary information on the complex subject of the fatigue strength of fabricated structural members for aircraft is presented in the test results obtained on several different types of airship girders subjected to axial tension and compression in a resonance fatigue machine. A description of this machine as well as numerous photographs of the fatigue failures are given. There is also presented an extended bibliography on the subject of fatigue strength.

  13. Computing and information sciences preliminary engineering design study

    SciTech Connect

    Schroeder, J O; Pearson, E W; Thomas, J J; Brothers, J W; Campbell, W K; DeVaney, D M; Jones, D R; Littlefield, R J; Peterson, M J

    1991-04-01

    This document presents the preliminary design concept for the integrated computing and information system to be included in the Environmental and Molecular Sciences Laboratory (EMSL) at the Pacific Northwest Laboratory, Richland, Washington, for the US Department of Energy (DOE). The EMSL is scheduled for completion and occupancy in 1994 or 1995 and will support the DOE environmental mission, in particular hazardous waste remediation. The focus of the report is on the Computing and Information Sciences engineering task of providing a fully integrated state-of-the-art computing environment for simulation, experimentation and analysis in support of molecular research. The EMSL will house two major research organizations, the Molecular Sciences Research Center (MSRC) and part of the Environmental Sciences Research Center (ESRC). Included in the report is a preliminary description of the computing and information system to be included. The proposed system architecture is based on a preliminary understanding of the EMSL users' needs for computational resources. As users understand more about the scientific challenges they face, the definition of the functional requirements will change. At the same time, the engineering team will be gaining experience with new computing technologies. Accordingly, the design architecture must evolve to reflect this new understanding of functional requirements and enabling technologies. 3 figs., 2 tabs.

  14. Finding the Lightcurve and Rotation Period of Minor Planet 7694 Krasetin

    NASA Astrophysics Data System (ADS)

    Odden, Caroline; Dear, Anna; Nix, Sabine

    2016-07-01

    The lightcurve of 7694 Krasetin was determined using images taken on twenty-one nights at the Philips Academy from 2015 September through November. Analysis of the data found a rotational period of 117.755 ± 0.017 h.

  15. Asteriod lightcurve analysis at Hunters Hill Observatory and collaborating stations - autumn 2006

    NASA Astrophysics Data System (ADS)

    Higgins, David; Pravec, Petr; Kusnirak, Peter; Galad, Adrian; Kornos, Leos; Pray, Donald; Koff, Robert A.

    2006-12-01

    Lightcurves for the following asteroids were obtained at Hunters Hill Observatory and one or more collaborating stations: 2195 Tengstrom, 2501 Lohja, 4580 Child, 9423 Abt, (9992) 1997 TG19, (10909) 1997 XB10, (12271) 1998 RC2, (12290) 1991 LZ, 12317 MadiCampbell, (31383) 1998 XJ94, (33116) 1998 BO12, (34442) 2000 SS64.

  16. Asteroid Lightcurve Analysis at the Via Capote Observatory: 1st Quarter 2011

    NASA Astrophysics Data System (ADS)

    Brinsfield, James W.

    2011-07-01

    Five asteroids were observed and their lightcurves measured at the Via Capote Observatory in early 2011: 862 Franzia (5.014 ± 0.001 h), 1383 Limburgia (> 5.0 h), 2802 Weisell (14.683 ± 0.002 h), 3577 Putilin (18.270 ± 0.002 h), and 52266 Van Flandern (9.89 ± 0.01 h).

  17. Asteroid Lightcurve Analysis at Hunters Hill Observatory and Collaborating Stations: November 2007 - March 2008

    NASA Astrophysics Data System (ADS)

    Higgins, David; Pravec, Petr; Kusnirak, Peter; Hornoch, Kamil; Brinsfield, James W.; Allen, Bill; Warner, Brian D.

    2008-09-01

    Lightcurves for the following asteroids were obtained at Hunters Hill Observatory and collaborating stations and then analysed to determine the synodic period and amplitude: 332 Siri, 443 Photographica, 547 Praxedis, 1650 Heckmann, 1620 Geographos, 1664 Felix, 1685 Toro, 1797 Schamasse, 2378 Pannekoek, 2606 Odessa, 2709 Sagan. 5783 Kumagaya, 6411 Tamaga, (7281) 1988 RX4, (8828) 1988 RC7, and (24114) 1999 VV23.

  18. Summary of the Preliminary Optical ICHMI Design Study: A Preliminary Engineering Design Study for a Standpipe Viewport

    SciTech Connect

    Anheier, Norman C.; Qiao, Hong; Berglin, Eric J.; Hatchell, Brian K.

    2013-12-26

    This summary report examines an in-vessel optical access concept intended to support standoff optical instrumentation, control and human-machine interface (ICHMI) systems for future advanced small modular reactor (AdvSMR) applications. Optical-based measurement and sensing systems for AdvSMR applications have several key benefits over traditional instrumentation and control systems used to monitor reactor process parameters, such as temperature, flow rate, pressure, and coolant chemistry (Anheier et al. 2013). Direct and continuous visualization of the in-vessel components can be maintained using external cameras. Many optical sensing techniques can be performed remotely using open optical beam path configurations. Not only are in-vessel cables eliminated by these configurations, but also sensitive optical monitoring components (e.g., electronics, lasers, detectors, and cameras) can be placed outside the reactor vessel in the instrument vault, containment building, or other locations where temperatures and radiation levels are much lower. However, the extreme AdvSMR environment present challenges for optical access designs and optical materials. Optical access is not provided in any commercial nuclear power plant or featured in any reactor design, although successful implementation of optical access has been demonstrated in test reactors (Arkani and Gharib 2009). This report outlines the key engineering considerations for an AdvSMR optical access concept. Strict American Society of Mechanical Engineers (ASME) construction codes must be followed for any U.S. nuclear facility component (ASME 2013); however, the scope of this study is to evaluate the preliminary engineering issues for this concept, rather than developing a nuclear-qualified design. In addition, this study does not consider accident design requirements. In-vessel optical access using a standpipe viewport concept serves as a test case to explore the engineering challenges and performance requirements

  19. Crystallization and preliminary X-ray diffraction study of thermostable RNase HIII from Bacillus stearothermophilus

    SciTech Connect

    Chon, Hyongi; Matsumura, Hiroyoshi; Koga, Yuichi; Takano, Kazufumi; Kanaya, Shigenori

    2005-03-01

    A thermostable ribonuclease HIII from B. stearothermophilus (Bst RNase HIII) was crystallized and preliminary crystallographic studies were performed. Plate-like overlapping polycrystals were grown by the sitting-drop vapour-diffusion method at 283 K.

  20. Characterizing the V-band Light-curves of Hydrogen-rich Type II Supernovae

    NASA Astrophysics Data System (ADS)

    Anderson, Joseph P.; González-Gaitán, Santiago; Hamuy, Mario; Gutiérrez, Claudia P.; Stritzinger, Maximilian D.; Olivares E., Felipe; Phillips, Mark M.; Schulze, Steve; Antezana, Roberto; Bolt, Luis; Campillay, Abdo; Castellón, Sergio; Contreras, Carlos; de Jaeger, Thomas; Folatelli, Gastón; Förster, Francisco; Freedman, Wendy L.; González, Luis; Hsiao, Eric; Krzemiński, Wojtek; Krisciunas, Kevin; Maza, José; McCarthy, Patrick; Morrell, Nidia I.; Persson, Sven E.; Roth, Miguel; Salgado, Francisco; Suntzeff, Nicholas B.; Thomas-Osip, Joanna

    2014-05-01

    We present an analysis of the diversity of V-band light-curves of hydrogen-rich type II supernovae. Analyzing a sample of 116 supernovae, several magnitude measurements are defined, together with decline rates at different epochs, and time durations of different phases. It is found that magnitudes measured at maximum light correlate more strongly with decline rates than those measured at other epochs: brighter supernovae at maximum generally have faster declining light-curves at all epochs. We find a relation between the decline rate during the "plateau" phase and peak magnitudes, which has a dispersion of 0.56 mag, offering the prospect of using type II supernovae as purely photometric distance indicators. Our analysis suggests that the type II population spans a continuum from low-luminosity events which have flat light-curves during the "plateau" stage, through to the brightest events which decline much faster. A large range in optically thick phase durations is observed, implying a range in progenitor envelope masses at the epoch of explosion. During the radioactive tails, we find many supernovae with faster declining light-curves than expected from full trapping of radioactive emission, implying low mass ejecta. It is suggested that the main driver of light-curve diversity is the extent of hydrogen envelopes retained before explosion. Finally, a new classification scheme is introduced where hydrogen-rich events are typed as simply "SN II" with an "s 2" value giving the decline rate during the "plateau" phase, indicating its morphological type. Based on observations obtained with the du-Pont and Swope telescopes at LCO, and the Steward Observatory's CTIO60, SO90 and CTIO36 telescopes.

  1. Characterizing the V-band light-curves of hydrogen-rich type II supernovae

    SciTech Connect

    Anderson, Joseph P.; González-Gaitán, Santiago; Hamuy, Mario; Gutiérrez, Claudia P.; Antezana, Roberto; De Jaeger, Thomas; Förster, Francisco; González, Luis; Stritzinger, Maximilian D.; Contreras, Carlos; Olivares E, Felipe; Phillips, Mark M.; Campillay, Abdo; Castellón, Sergio; Hsiao, Eric; Schulze, Steve; Bolt, Luis; Folatelli, Gastón; Freedman, Wendy L.; Krzemiński, Wojtek; and others

    2014-05-01

    We present an analysis of the diversity of V-band light-curves of hydrogen-rich type II supernovae. Analyzing a sample of 116 supernovae, several magnitude measurements are defined, together with decline rates at different epochs, and time durations of different phases. It is found that magnitudes measured at maximum light correlate more strongly with decline rates than those measured at other epochs: brighter supernovae at maximum generally have faster declining light-curves at all epochs. We find a relation between the decline rate during the 'plateau' phase and peak magnitudes, which has a dispersion of 0.56 mag, offering the prospect of using type II supernovae as purely photometric distance indicators. Our analysis suggests that the type II population spans a continuum from low-luminosity events which have flat light-curves during the 'plateau' stage, through to the brightest events which decline much faster. A large range in optically thick phase durations is observed, implying a range in progenitor envelope masses at the epoch of explosion. During the radioactive tails, we find many supernovae with faster declining light-curves than expected from full trapping of radioactive emission, implying low mass ejecta. It is suggested that the main driver of light-curve diversity is the extent of hydrogen envelopes retained before explosion. Finally, a new classification scheme is introduced where hydrogen-rich events are typed as simply 'SN II' with an 's {sub 2}' value giving the decline rate during the 'plateau' phase, indicating its morphological type.

  2. Decontamination of Johnston Island Coral: a preliminary study

    SciTech Connect

    Kochen, R.L.

    1986-02-17

    A preliminary investigation was completed on the characterization and decontamination of coral samples from Johnston Island. These samples were found to contain individual particles (2 to 0.25 mm) of contaminated coral as well as a piece of contaminated magnetic metal. They ranged in activity from about 70 to 811 nCi Am-241. The decontamination methods investigated were froth flotation, ferrite treatment, attrition scrubbing, ultrasonic treatment and dry sieving. Dry sieving, the more effective technique, separated about 42 wt % of the coral into a decontaminated fraction. This fraction (>4 mm) contained about 0.5% of the total activity. 7 refs., 3 tabs.

  3. Lightcurves of Type Ia Supernovae from the La Silla-QUEST Survey and the Carnegie Supernova Project

    NASA Astrophysics Data System (ADS)

    Walker, Emma S.; Baltay, C.; Rabinowitz, D. L.; Mckinnon, R.; Contreras, C.; Hsiao, E.; Phillips, M.; Morrell, N.; Campillay, A.; Gonzalez, C.; Seron, J.; Krisciunas, K.; Tucker, B. E.

    2014-01-01

    We present the first analysis of Type Ia supernovae found by the La Silla-QUEST (LSQ) survey and followed-up by the Carnegie Supernova Project (CSP) using the 1m SWOPE telescope. LSQ uses the 1m ESO Schmidt telescope on La Silla with a wide-band filter (4000-7000 Angstrom) to search for transient events with the aim of discovering and obtaining lightcurves for 500 low-redshift (z<0.1) supernovae over the 5-year lifetime of the project. The supernovae we present here are followed in a number of different filters, selected from BVugri, and will contribute towards the goal of a well-studied local sample for cosmology.

  4. A Preliminary Case Study for Rectenna Sites in Indonesia

    NASA Astrophysics Data System (ADS)

    Purwanto, Y.; Collins, P.

    2004-12-01

    Electricity power generation using alternative energy sources in Indonesia has become an important policy. Until now, the contribution from alternative energy sources (especially from renewable energy sources) is very small, only about 1% of the total energy supply. It is expected that in the next 10 years this contribution will be raised to 20%. The development of renewable energy sources is primarily performed in remote areas, that are poor in infrastructure facilities. This is considered to be a good policy since there are many such remote areas in Indonesia that need development programs. The existence of Solar Power Satellite system will open a new horizon in alternative energy supply, including Indonesia, because of its higher efficiency compared to conventional terrestrial solar cells, with almost no influence from either climate or solar position. Like other countries in the world, Indonesia, although one of the largest mineral energy producers in the world (i.e. oil, coal, and natural gas), still gives attention to energy diversification programs, including solar energy utilization. SPS, being based on solar energy, could be a good choice. The Indonesian archipelago consists of thousands of islands (more than 13,000) and is the equatorial country with the longest equatorial extent (more than 5000 km). This condition is very good for energy reception from the SPS 2000 pilot plant since the energy transmitting system (spacetenna) will orbit above the equator. Along the equator there could be placed more than four receiving stations (rectenna), especially in remote areas. Thus, it is very important to consider the involvement of Indonesia in SPS energy reception research. This paper describes a preliminary study of the development possibilities in SPS energy reception in Indonesia. To define the rectenna sites and physical development aspect, this study considers some major aspects: environmental, technical, social, and economic aspects. Environmental aspects

  5. A preliminary study of the modified Ericsson for space power

    NASA Technical Reports Server (NTRS)

    Berner, J.; Louis, J. F.; Juhasz, A.

    1985-01-01

    Simple modifications of the Ericsson cycle are analyzed for their application as high power, compact and reliable space power systems. They use the same components as the technologically advanced and reliable Brayton system. These modifications approximate the Ericsson cycle's isothermal expansion by several stages of expansion with reheat and the isothermal compression by several compression stages with intercooling. Preliminary cycle analysis including non-ideal components indicates potential advantages in both power per unit area and efficiency over the Brayton system. Evaluation of the system mass indicates a significant mass and radiator area advantage of a Modified Ericsson cycle using one reheat and one expansion stage when a high temperature titanium radiator is used. Whereas the configuration using one reheat and one intercooling with two stages of compression and expansion provided the lowest mass per unit power using a lower temperature aluminum radiator.

  6. Preliminary study of niobium alloy contamination by transport through helium

    NASA Technical Reports Server (NTRS)

    Scheuermann, Coulson M.; Moore, Thomas J.; Wheeler, Donald R.

    1987-01-01

    Preliminary tests were conducted to determine if interstitial element transport through a circulating helium working fluid was a potential problem in Brayton and Stirling space power systems. Test specimens exposed to a thermal gradient for up to 3000-hr included Nb-1%Zr, a Sm-Co alloy (referred to as SmCo in this paper), Hiperco 50 steel, and alumina to simulate various engine components of the Brayton and Stirling systems. Results indicate that helium transport of interstitial contaminants can be minimized over a 7-yr life with a monometallic Nb-1%Zr design. Exposure with other materials indicated a potential for interstitial contaminant transport. Determination of contamination kinetics and the effects on structural integrity will require additional testing.

  7. Characterization and subsequent utilization of microbially solubilized coal: Preliminary studies

    SciTech Connect

    Davison, B.H.; Nicklaus, D.M.; Woodward, C.A.; Lewis, S.N.; Faison, B.D.

    1989-01-01

    The solubilization of low-ranked coals by fungi, such as Paecilomyces and Candida, in defined submerged culture systems has been demonstrated. Current efforts focus on the characterization of the aqueous solubilized coal products and the development of technologies for their subsequent utilization. Solubilized coal products have been fractionated, and preliminary characterizations performed. Differences in product composition have been detected with respect to the organism used in culture duration. Prospects for the conversion of the aerobically-solubilized coal into less-oxidized products have been developed which can remain active and viable in the presence of the aqueous coal product or vanillin, a coal model compound. The results suggest that a methanogenic consortium was able to produce methane and carbon dioxide from the product of coal biosolubilization by Paecilomyces as a sole carbon source. Work continues on the development of cultures able to convert the aqueous coal product and its various fractions into methane or fuel alcohols. 17 refs., 8 figs.

  8. Stability Analysis for Cellinoid Shape Model in Inverse Process from Lightcurves

    NASA Astrophysics Data System (ADS)

    Lu, Xiao-Ping; Ip, Wing-Huen; Song, Yun-Lin; Zhao, Hai-Bin

    2016-04-01

    Based on the special shape first introduced by Alberto Cellino, which consists of eight ellipsoidal octants with the constraint that adjacent octants must have two identical semi-axes, an efficient algorithm to derive the physical parameters, such as the rotational period, spin axis, and overall shape from either lightcurves or sparse photometric data of asteroids, is developed by Lu et al.[1]. They call this model 'Cellinoid' shape model. Numerical applications confirm that the cellinoid shape model could derive the best-fit rotational period for the asteroid from several lightcurves observed in one apparition. Furthermore by exploiting more lightcurves observed in various viewing circumstances, the derived spin axis could be refined [2]. Additionally the cellinoid shape model is applied to the sparse Hipparcos data with the average number of measurements being of the order of 70 per object, similar to the future catalog of the ongoing space project, Gaia [3]. The derived rotational periods from 70 sparse measurements are accurate and the spin axes are close to the known results, derived from lightcurves by other methods. With only 3 more parameters than the traditional triaxial ellipsoid, the cellinoid shape model of having the asymmetric morphology could perform efficiently and simulate the real asteroids better. That could be employed for the huge number of photometric sparse data observed by Gaia in the coming future. For thoroughly investigating the relationship between the morphology of the synthetic lightcurves generated by the cellinoid shape model and its six semi-axes, the numerical tests are implemented to compare the synthetic lightcurves generated by various cellinoid models. Furthermore, the sensitivity of the stable spin axis of cellinoid shape model with respect to its semi-axes is analyzed, too. These numerical tests provide important information for optimizing the aforementioned algorithm to search the physical parameters for asteroids based on

  9. Preliminary study of a centrifugal-flow singlet oxygen generator

    SciTech Connect

    Shi, W; Deng, L; Yang, H; Sha, G; Zhang, C

    2008-02-28

    By using the concept of a high-pressure, gravity-independent singlet oxygen generator (SOG) proposed by Emanuel and based on the principle that a rotating fluid is capable of producing an enormous centrifugal force, a novel-type centrifugal-flow singlet oxygen generator (CFSOG) was designed and constructed. In this device, O{sub 2}({sup 1}{delta}) was generated in the reaction of gaseous Cl{sub 2} with a rotating basic hydrogen peroxide (BHP) liquid flow and then was removed from the BHP liquid phase by the centrifugal force. Meanwhile, the microdroplets formed during the Cl{sub 2}+BHP reaction were removed from the O{sub 2}({sup 1}{delta}) gas flow by the centrifugal force produced by the high-speed flow along an arc-shaped channel. Preliminary investigations showed that, because the specific reactive surface area of this SOG was noticeably larger than that of the jet-SOG normally used in current chemical oxygen-iodine lasers (COILs), the O{sub 2}({sup 1}{delta}) yield of {approx}60%, the O{sub 2}({sup 1}{delta}) partial pressure as high as 31 Torr, and chlorine utilisation higher than 96% were realised. Moreover, steady operation was obtained. (laser components)

  10. Analytic study of the Tadoma method: background and preliminary results.

    PubMed

    Norton, S J; Schultz, M C; Reed, C M; Braida, L D; Durlach, N I; Rabinowitz, W M; Chomsky, C

    1977-09-01

    Certain deaf-blind persons have been taught, through the Tadoma method of speechreading, to use vibrotactile cues from the face and neck to understand speech. This paper reports the results of preliminary tests of the speechreading ability of one adult Tadoma user. The tests were of four major types: (1) discrimination of speech stimuli; (2) recognition of words in isolation and in sentences; (3) interpretation of prosodic and syntactic features in sentences; and (4) comprehension of written (Braille) and oral speech. Words in highly contextual environments were much better perceived than were words in low-context environments. Many of the word errors involved phonemic substitutions which shared articulatory features with the target phonemes, with a higher error rate for vowels than consonants. Relative to performance on word-recognition tests, performance on some of the discrimination tests was worse than expected. Perception of sentences appeared to be mildly sensitive to rate of talking and to speaker differences. Results of the tests on perception of prosodic and syntactic features, while inconclusive, indicate that many of the features tested were not used in interpreting sentences. On an English comprehension test, a higher score was obtained for items administered in Braille than through oral presentation. PMID:904318

  11. The Myres Hill remote sensing intercomparison study: preliminary results

    NASA Astrophysics Data System (ADS)

    Clive, P. J. M.; Chindurza, I.; Ravey, I.; Bass, J.; Boyle, R. J.; Jones, P.; Lang, S. J.; Bradley, S.; Hay, L.; Oldroyd, A.; Stickland, M.

    2008-05-01

    Two remote sensing techniques (SODAR and LIDAR) have been developed for measuring wind speed and turbulence from ground level up to altitudes of 300 m or higher. Although originally developed in the defence sector, these techniques are now generating considerable interest in the renewable energy and meteorological sectors. Despite the benefits of these instruments they are not yet generally accepted for due diligence measurements by wind energy developers and financial institutions. There is a requirement for a series of independent assessments of these new metrology techniques, comparing their measurements with the approved cup-type anemometer readings. This is being addressed at TUV NEL's Myres Hill wind turbine test site in a measurement programme supported by the DIUS National Measurement Systems Measurement for Innovators scheme and a consortium of 21 industrial collaborators. Data from SODAR and LIDAR systems are being compared with results from cup-type anemometers mounted at different heights on an 80m meteorological mast. An ultrasonic sensor is also mounted on the mast. The objective of the test programme is to assess the effectiveness of SODAR and LIDAR wind speed measurement techniques under different operating regimes and atmospheric conditions. Results from the measurements will provide definitive data on the performance of the remote wind speed sensing techniques under test on complex terrain typical of many wind farm sites. Preliminary measurements based on data acquired during the initial measurement campaign are presented.

  12. Preliminary study of a dispersed fringe type sensing system

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Liu, Gen-Rong; Wang, Yue-Fei; Li, Ye-Ping; Zhang, Ya-Jun; Zhang, Liang

    2009-08-01

    Telescopes with large aspherical primary mirrors collect more light and are therefore sought after by astronomers. Instead of using a single large one-piece mirror, smaller segments can be assembled into a useable telescopic primary. Because the segments must fit together to create the effect of a single mirror, segmented optics present unique challenges to the fabrication and testing that are absent in monolithic optics. A dispersed fringe sensor (DFS) using a broadband point source is an efficient method for cophasing and is also highly automated and robust. Unlike the widely adopted Shack-Hartmann Wavefront sensor and curvature wavefront sensor with edge sensors for calibration of relative pistons, DFS can estimate the piston between segments by only using the spectrum formed by the transmissive grating's dispersion, and therefore can replace the edge sensors, which are difficult to calibrate. We introduce the theory of the DFS and Dispersed Hartmann Sensor (DHS) for further utilization of the coarse phasing method of DFS. According to the theory, we bring out the preliminary system design of the cophasing experimental system based on DFS and DHS which is now established in our institute. Finally, a summary is reached.

  13. Combining asteroid models derived by lightcurve inversion with asteroidal occultation silhouettes

    NASA Astrophysics Data System (ADS)

    Ďurech, Josef; Kaasalainen, Mikko; Herald, David; Dunham, David; Timerson, Brad; Hanuš, Josef; Frappa, Eric; Talbot, John; Hayamizu, Tsutomu; Warner, Brian D.; Pilcher, Frederick; Galád, Adrián

    2011-08-01

    Asteroid sizes can be directly measured by observing occultations of stars by asteroids. When there are enough observations across the path of the shadow, the asteroid's projected silhouette can be reconstructed. Asteroid shape models derived from photometry by the lightcurve inversion method enable us to predict the orientation of an asteroid for the time of occultation. By scaling the shape model to fit the occultation chords, we can determine the asteroid size with a relative accuracy of typically ˜10%. We combine shape and spin state models of 44 asteroids (14 of them are new or updated models) with the available occultation data to derive asteroid effective diameters. In many cases, occultations allow us to reject one of two possible pole solutions that were derived from photometry. We show that by combining results obtained from lightcurve inversion with occultation timings, we can obtain unique physical models of asteroids.

  14. Asteroidal Occultation Silhouettes Combined with Asteroid Models Derived by Lightcurve Inversion

    NASA Astrophysics Data System (ADS)

    Durech, Josef; Kaasalainen, M.; Herald, D.; Dunham, D.; Timerson, B.; Hanus, J.; Frappa, E.; Talbot, J.; Hayamizu, T.; Warner, B. D.; Pilcher, F.; Galad, A.

    2010-10-01

    Asteroid sizes can be directly measured by observing occultations of stars by asteroids. When there are enough observations across the path of the shadow, the asteroid's projected silhouette can be reconstructed. We present our analysis of occultation data we combined with convex asteroid models. Asteroid shape models derived from photometry by the lightcurve inversion method enabled us to compute the orientation of an asteroid for the time of occultation. By scaling the shape models to fit the occultation chords, we determined the asteroid sizes with a relative accuracy of typically 10%. We combined shape and spin state models of 44 asteroids (14 of them were new or updated models) with the available occultation data to derive asteroid effective diameters. In many cases, occultations allowed us to reject one of two possible pole solutions that were derived from photometry. Our results demonstrate the possibility of deriving unique physical models of asteroids by combining shape models obtained from lightcurve inversion with occultation timings.

  15. Lightcurve and Rotation Period Determination for 1492 Oppolzer and (9773) 1993 MG1

    NASA Astrophysics Data System (ADS)

    Salvaggio, Fabio; Franco, Lorenzo; Marchini, Alessandro; Papini, Riccardo

    2015-10-01

    Photometric observations of the main-belt asteroids 1492 Oppolzer and (9773) 1993 MG1 were performed by the authors in 2015 April-July. Analysis of the data revealed bimodal lightcurves for each object. For 1492 Oppolzer, we found a synodic period of P = 3.770 ± 0.001 h; for (9773) 1993 MG1, we found P = 2.746 ± 0.001 h.

  16. Asteroid Lightcurve Analysis at the Palmer Divide Observatory: December 2007 - March 2008

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.

    2008-09-01

    Lightcurves for 17 asteroids were obtained at the Palmer Divide Observatory from December 2007 to early March 2008: 793 Arizona, 1092 Lilium, 2093 Genichesk, 3086 Kalbaugh, 4859 Fraknoi, 5806 Archieroy, 6296 Cleveland, 6310 Jankonke, 6384 Kervin, (7283) 1989 TX15, 7560 Spudis, (7579) 1990 TN1, (13578) 1993 MK, (24819) 1994 XY4, (26471) 2000 AS152, (26916) 1996 RR2, and 2008 CN1.

  17. Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2009 June-September

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.

    2010-01-01

    Lightcurves for 17 asteroids were obtained at the Palmer Divide Observatory (PDO) from 2009 June through September: 434 Hungaria, 790 Pretoria, 950 Ahrensa, 1203 Nanna, 1575 Winifred, (5639) 1989 PE, 6447 Terrycole, (6461) 1993 VB5, 6859 Datemasamune, (8639) 1986 VB1, 15374 Teta, (20614) 1999 SN3, (26916) 1996 RR2, 27776 Cortland, (32209) 2000 OW9, (46818) 1998 MZ24, and (77799) 2001 QV88.

  18. Lightcurve-based search for main-belt comets with the PTF survey

    NASA Astrophysics Data System (ADS)

    Waszczak, A.; Ofek, E.; Kulkarni, S.

    2014-07-01

    Cometary activity in main-belt asteroids remains poorly-understood but has profound implications for our understanding of solar system formation (e.g., Hsieh & Jewit 2006, Science 312). Two methods to detect activity are (1) morphological, i.e., measuring extendedness on a per-observation basis, and (2) photometric, i.e., measuring intrinsic brightness variation over time. Waszczak et al. (2013, MNRAS 433) described initial results on method (1); we now present progress on method (2). We extracted 7.2 million observations of 395,000 asteroids from 5 years (2009--2014) of Palomar Transient Factory (PTF) survey data (Law et al. 2009, PASP 121; Rau et al. 2009, PASP 121). Of these, we fit 2.2 million observations of 63,000 asteroids to a lightcurve model incorporating rotation with 2nd-order Fourier coefficients and the IAU phase-function parameter G. Each fit includes ≥15 observations within a single opposition and filter (92 % r-band, 8 % g-band; multiple fits exist for 4,900 objects seen in multiple oppositions and/or both filters). As a sample, the RMS scatter and reduced χ^2 of our lightcurves are a factor of two smaller than those produced by the fiducial model used by JPL's HORIZONS and the MPC (i.e., no rotational correction and a fixed G=0.15). We describe a statistical search for cometary contributions in the residuals of these lightcurves.

  19. Identification of Emerging Self-Injurious Behavior in Young Children: A Preliminary Study

    ERIC Educational Resources Information Center

    Kurtz, Patricia F.; Chin, Michelle D.; Huete, John M.; Cataldo, Michael F.

    2012-01-01

    Self-injurious behavior (SIB) is a chronic disorder that often begins in early childhood; however, few studies have examined the onset of SIB in young children. This preliminary study reports on the identification, assessment, and observation of SIB in 32 children who had begun to engage in SIB within the previous 6 months. Participants were under…

  20. Preliminary Study: Special Education Doctoral Students' Perceptions of Self-Determination

    ERIC Educational Resources Information Center

    Kim, Kyeong-Hwa; Morningstar, Mary E.; Jung, Sungmin

    2014-01-01

    This preliminary study investigated 118 special education doctoral students' knowledge of and attitudes toward self-determination. In addition, this study examined the relationship between self-determination coursework and special education doctoral students' perceptions of how well they were prepared for implementing self-determination…

  1. A Preliminary Study of Guided Math in Title I Elementary Schools

    ERIC Educational Resources Information Center

    Fielder, Katherine Roberts

    2013-01-01

    This study sought to provide a preliminary examination of the relationship between the implementation of Guided Math and student achievement in Title I schools as measured by the percentage of students who met or exceeded the standard for the Georgia Mathematics CRCT. The study examined data from thirty Title I elementary schools in one suburban…

  2. PRELIMINARY EXPOSURE ASSESSMENT FINDINGS FROM THE TAMPA ASTHMATIC CHILDREN'S STUDY

    EPA Science Inventory

    The Tampa Asthmatic Children's Study (TACS) was a pilot study that focused on developing and evaluating air pollution exposure assessment methods and participant recruiting tools. The four-week study was performed in October and November, 2003. The study involved repeated daily...

  3. The Type IIb SN 2011dh: Two years of observations and modelling of the lightcurves

    NASA Astrophysics Data System (ADS)

    Ergon, M.; Jerkstrand, A.; Sollerman, J.; Elias-Rosa, N.; Fransson, C.; Fraser, M.; Pastorello, A.; Kotak, R.; Taubenberger, S.; Tomasella, L.; Valenti, S.; Benetti, S.; Helou, G.; Kasliwal, M. M.; Maund, J.; Smartt, S. J.; Spyromilio, J.

    2015-08-01

    We present optical and near-infrared (NIR) photometry and spectroscopy as well as modelling of the lightcurves of the Type IIb supernova (SN) 2011dh. Our extensive dataset, for which we present the observations obtained after day 100, spans two years, and complemented with Spitzer mid-infrared (MIR) data, we use it to build an optical-to-MIR bolometric lightcurve between days 3 and 732. To model the bolometric lightcurve before day 400 we use a grid of hydrodynamical SN models, which allows us to determine the errors in the derived quantities, and a bolometric correction determined with steady-state non-local thermodynamic equilibrium (NLTE) modelling. Using this method we find a helium core mass of 3.1+0.7-0.4 M⊙ for SN 2011dh, consistent within error bars with previous results obtained using the bolometric lightcurve before day 80. We compute bolometric and broad-band lightcurves between days 100 and 500 from spectral steady-state NLTE models, presented and discussed in a companion paper. The preferred 12 M⊙ (initial mass) model, previously found to agree well with the observed spectra, shows a good overall agreement with the observed lightcurves, although some discrepancies exist. Time-dependent NLTE modelling shows that after day ~600 a steady-state assumption is no longer valid. The radioactive energy deposition in this phase is likely dominated by the positrons emitted in the decay of 56Co, but seems insufficient to reproduce the lightcurves, and what energy source is dominating the emitted flux is unclear. We find an excess in the K and the MIR bands developing between days 100 and 250, during which an increase in the optical decline rate is also observed. A local origin of the excess is suggested by the depth of the He i 20 581 Å absorption. Steady-state NLTE models with a modest dust opacity in the core (τ = 0.44), turned on during this period, reproduce the observed behaviour, but an additional excess in the Spitzer 4.5 μm band remains. Carbon

  4. PRELIMINARY HEALTH BURDEN ANALYSIS FOR EPIDEMIOLOGIC RECREATIONAL WATER STUDY

    EPA Science Inventory

    Introduction: The National Epidemiological and Environmental Assessment of Recreational Water Study (NEEAR) offers a rare opportunity for researchers. The study's design involves the collection of health data before and after visiting the beach in conjunction with water quality...

  5. The Status of Women in Alaska, 1977. A Preliminary Study.

    ERIC Educational Resources Information Center

    Jones, Dorothy M.; And Others

    To determine the precise nature and extent of the problem confronting Alaskan women, the Legislature in 1976 directed the Human Rights Commission to conduct a study on the status of women in education, employment, health, and the justice system. This publication contains the results of that study. Data for the study were secured through interviews…

  6. Preliminary planning study for safety relief valve experiments in a Mark III BWR pressure suppression system

    SciTech Connect

    McCauley, E.W.; Holman, G.S.

    1980-04-21

    In response to a request from the Water Reactor Safety Research Division of the US NRC, a preliminary study is provided which identifies key features and consideration involved in planning a comprehensive in-plant Safety Relief Valve experimental program for a Mark III containment design. The report provides identification of program objectives, measurement system requirements, and some details quantifying expected system response. In addition, a preliminary test matrix is outlined which involves a supporting philosophy intended to enhance the usefulness of the experimental results for all members of the program team: experimentalists, analysts, and plant operator.

  7. Systems design study of the Pioneer Venus spacecraft. Volume 2. Preliminary program development plan

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The preliminary development plan for the Pioneer Venus program is presented. This preliminary plan treats only developmental aspects that would have a significant effect on program cost. These significant development areas were: master program schedule planning; test planning - both unit and system testing for probes/orbiter/ probe bus; ground support equipment; performance assurance; and science integration Various test planning options and test method techniques were evaluated in terms of achieving a low-cost program without degrading mission performance or system reliability. The approaches studied and the methodology of the selected approach are defined.

  8. Preliminary study of Kelso Dunes using AVIRIS, TM, and AIRSAR

    NASA Technical Reports Server (NTRS)

    Xu, Pung; Blumberg, Dan G.; Greeley, Ronald

    1995-01-01

    Remote sensing of sand dunes helps in the understanding of aeolian process and provides important information about the regional geologic history, environmental change, and desertification. Remotely sensed data combined with field studies are valuable in studying dune morphology, regional aeolian dynamics, and aeolian depositional history. In particular, active and inactive sands of the Kelso Dunes have been studied using landsat TM and AIRSAR. In this report, we describe the use of AVIRIS data to study the Kelso dunes and to compare the AVIRIS information with that from TM and AIRSAR.

  9. Young Children's Perceptions of Scientists: A Preliminary Study

    ERIC Educational Resources Information Center

    Buldu, Mehmet

    2006-01-01

    Background: Since the 1950s, there has been a growing body of research dealing with perceptions children have of scientists. Typically, research studies in this area have utilized children's drawings in an effort to discern what those perceptions are. Studies assessing perceptions children have of scientists have shown that children have…

  10. Supporting Off-Shore Students: A Preliminary Study

    ERIC Educational Resources Information Center

    Hussin, Virginia

    2007-01-01

    This paper reports on the first part of a recent research study into current initiatives to support the learning of non-English speaking background (NESB) transnational students in Asia who are studying off-shore at Australian universities. Learning support and development staff in 12 universities were surveyed using a questionnaire. The survey…