Science.gov

Sample records for toivo univer ao

  1. La matiere noire dans l'Univers.

    NASA Astrophysics Data System (ADS)

    Mamon, G.

    Parmi les mille questions que l'on peut se poser sur l'Univers, les plus fondamentales concernent son contenu : De quoi est faite la matière de l'Univers ? Est-ce que la matière de l'Univers est principalement constituée d'étoiles, ou bien de gaz interstellaire, de poussières interstellaires, de planètes, petits astéroïdes, ou de trous noirs ? Ou doit-on admettre que l'Univers est composé d'une autre forme de matière que l'on ne connaît pas, qui serait basée sur des particules élémentaires plus exotiques que les protons, neutrons et électrons qui constituent la matière ordinaire, dite baryonique?

  2. 73. Photocopy of Photograph (original located in Univ. of Denver ...

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

    73. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, March, 1905. SILT FILTERING 'THROUGH NORTH DAM; NORTH DAM FROM DOWNSTREAM SHOWING DIRT FILL FILTERING THROUGH DAM. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  3. 41. Photocopy of Photograph (original located in Univ. of Denver ...

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

    41. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, March, 1905. NORTH DAM OF MILNER DAM; DOWNSTREAM AFTER TUNNEL CLOSURE; SILT BERM COMING THROUGH DAM. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  4. 38. Photocopy of Photograph (original located in Univ. of Denver ...

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

    38. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, March, 1905. NORTH DAM AT MILNER DAM; NORTH VIEW, UPPER SLOPE OF MAIN CHANNEL DAM, DIRT FILL CONTINUING. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  5. 52. Photocopy of Photograph (original located in Univ. of Denver ...

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

    52. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, March, 1905. MILNER TUNNEL CLOSURE GATES AND GROUP. GROUP ON GATE PLATFORM JUST BEFORE LOWERING GATES. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  6. 81. Photocopy of Photograph (original located in Univ. of Denver ...

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

    81. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, date unknown. DRY CREEK DAM, TWIN FALLS COUNTY, SOUTH OF MURTAUGH, IDAHO; DRIVING SHEET PILING TO SHUT OFF SEEPAGE. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  7. 72. Photocopy of Photograph (original located in Univ. of Denver ...

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

    72. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, March, 1905. CONTRACTOR'S DAM BELOW MILNER DAM USED TO RAISE WATER TO POWER DITCH. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  8. 64. Photocopy of Photograph (original located in Univ. of Denver ...

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

    64. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, March, 1905. MILNER DAM. WATER FLOODING OVER SPILLWAY FOR FIRST TIME. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  9. 80. Photocopy of Photograph (original located in Univ. of Denver ...

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

    80. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, March, 1905. WASTE GATES ON MAIN CANAL. F.H. BUHL OVERLOOKS THE NEWLY OPENED CANAL AT GATES ONE MILE BELOW DAM. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  10. 47. Photocopy of Photograph (original located in Univ. of Denver ...

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

    47. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, March, 1905. MILNER DAM; RIP-RAPPED UPPER SLOPE OF CENTER DAM; CROWD ALONG CHANNEL TO TUNNELS. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  11. 50. Photocopy of Photograph (original located in Univ. of Denver ...

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

    50. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, March, 1905. MILNER DAM TUNNELS. CHANNEL APPROACHING TUNNELS; SNAKE RIVER PASSING THROUGH. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  12. 53. Photocopy of Photograph (original located in Univ. of Denver ...

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

    53. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, March, 1905. MILNER DAM TUNNEL CHANNEL AND APPROACH TO TUNNEL GATES. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  13. 59. Photocopy of Photograph (original located in Univ. of Denver ...

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

    59. Photocopy of Photograph (original located in Univ. of Denver collection) C.R. Savage, Photographer, date unknown. MILNER DAM; TUNNEL OUTLETS WITH SNAKE RIVER PASSING THROUGH. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  14. 70. Photocopy of Photograph (original located in Univ. of Denver ...

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

    70. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, March, 1905. SNAKE RIVER SHALLOWS AFTER TUNNEL CLOSURE; DOWNSTREAM FROM MILNER DAM. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  15. 48. Photocopy of Photograph (original located in Univ. of Denver ...

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

    48. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, March, 1905. MILNER DAM; WEST VIEW ACROSS DAM FROM MIDDLE DAM; SNAKE RIVER EXITING FROM TUNNELS. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  16. 45. Photocopy of Photograph (original located in Univ. of Denver ...

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

    45. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, March 1905. SNAKE RIVER BEHIND MILNER DAM; MILNER RESERVOIR RISING. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  17. 75. Photocopy of Photograph (original located in Univ. of Denver ...

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

    75. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, March, 1905. SNAKE RIVER GOING DRY AT MILNER. POWER DITCH AT RIGHT; RIVER IN POOLS FOLLOWING GATE CLOSURE. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  18. Jayant Narlikar : dernier rempart de l'Univers stationnaire

    NASA Astrophysics Data System (ADS)

    Bonnet-Bidaud, J. M.

    2005-04-01

    "Travailler dans une seule direction ne prouve pas que cela soit la bonne". L'astrophysicien indien, Jayant Narlikar prone la diversité des approches en recherche fondamentale - c'est bien le moins pour ce tenant de l'Univers stationnaire, théorie alternative à celle du Big Bang. Mais, selon lui, une telle démarche devient rare en cosmologie, malheureusement.

  19. Planetes, etoiles, galaxies, trous noirs : comment peser l'Univers ?

    NASA Astrophysics Data System (ADS)

    Bonnet-Bidaud, J. M.

    2001-05-01

    Depuis plus de trois siècles, les astronomes affinent leurs méthodes pour `peser' à distance les astres qui peuplent l'Univers. Après avoir décortiqué les orbites, étudié les décalages vers le rouge, épluché la luminosité, les scientifiques ont ajouté les lentilles gravitationnelles à la liste de leurs `balances' cosmiques. Outils et moyens de ceux qui évaluent la masse des objets célestes.

  20. Retinal AO OCT

    NASA Astrophysics Data System (ADS)

    Zawadzki, Robert J.; Miller, Donald T.

    The last two decades have witnessed extraordinary advances in optical technology to image noninvasively and at high resolution the posterior segment of the eye. Two of the most impactful technological advancements over this period have arguably been optical coherence tomography (OCT) and adaptive optics (AO). The strengths of these technologies complement each other and when combined have been shown to provide unprecedented, micron-scale resolution (<3 μm) in all three dimensions and sensitivity to image the cellular retina in the living eye. This powerful extension of OCT, that is AO-OCT, is the focus of this chapter. It presents key aspects of designing and implementing AO-OCT systems. Particular attention is devoted to the relevant optical properties of the eye that ultimately define these systems, AO componentry and operation tailored for ophthalmic use, and of course use of the latest technologies and methods in OCT for ocular imaging. It surveys the wide range of AO-OCT designs that have been developed for retinal imaging, with AO integrated into every major OCT design configuration. Finally, it reviews the scientific and clinical studies reported to date that show the exciting potential of AO-OCT to image the microscopic retina and fundus in ways not previously possible with other noninvasive methods and a look to future developments in this rapidly growing field.

  1. A Needs Assessment for the Introduction of a Food Science Program at the Univ. of Guyana

    ERIC Educational Resources Information Center

    Morrison, Donna

    2012-01-01

    This research describes the outcome of a needs assessment to determine whether the Univ. of Guyana should introduce a Food Science program. The research design utilized interviews and questionnaires to large manufacturing organizations and agroprocessors to determine if the required skills are available for the manufacturing process. Results…

  2. 37. Photocopy of Photograph(original located in Univ. of Denver collection). ...

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

    37. Photocopy of Photograph(original located in Univ. of Denver collection). C.R. Savage, Photographer, March, 1905. NORTH AND MIDDLE DAMS, MILNER DAM, MAIN CHANNEL DAM, FOREGROUND; MIDDLE DAM AND TUNNEL REGULATORS, BACKGROUND. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  3. AO Group Annual Report

    SciTech Connect

    Olivier, S

    2005-10-04

    The Adaptive Optics (AO) Group in I Division develops and tests a broad range of advanced wavefront control technologies. Current applications focus on: Remote sensing, High power lasers, Astronomy, and Human vision. In the area of remote sensing, the AO Group leads a collaborative effort with LLNL's Nonproliferation, Arms Control & International Security (NAI) Directorate on Enhanced Surveillance Imaging. The ability to detect and identify individual people or vehicles from long-range is an important requirement for proliferation detection and homeland security. High-resolution imaging along horizontal paths through the atmosphere is limited by turbulence, which blurs and distorts the image. For ranges over {approx}one km, visible image resolution can be reduced by over an order of magnitude. We have developed an approach based on speckle imaging that can correct the turbulence-induced blurring and provide high resolution imagery. The system records a series of short exposure images which freeze the atmospheric effects. We can then estimate the image magnitude and phase using a bispectral estimation algorithm which cancels the atmospheric effects while maintaining object information at the diffraction limit of the imaging system.

  4. All-in-one 3D printed microscopy chamber for multidimensional imaging, the UniverSlide.

    PubMed

    Alessandri, Kevin; Andrique, Laetitia; Feyeux, Maxime; Bikfalvi, Andreas; Nassoy, Pierre; Recher, Gaëlle

    2017-02-10

    While live 3D high resolution microscopy techniques are developing rapidly, their use for biological applications is partially hampered by practical difficulties such as the lack of a versatile sample chamber. Here, we propose the design of a multi-usage observation chamber adapted for live 3D bio-imaging. We show the usefulness and practicality of this chamber, which we named the UniverSlide, for live imaging of two case examples, namely multicellular systems encapsulated in sub-millimeter hydrogel shells and zebrafish larvae. We also demonstrate its versatility and compatibility with all microscopy devices by using upright or inverted microscope configurations after loading the UniverSlide with fixed or living samples. Further, the device is applicable for medium/high throughput screening and automatized multi-position image acquisition, providing a constraint-free but stable and parallelized immobilization of the samples. The frame of the UniverSlide is fabricated using a stereolithography 3D printer, has the size of a microscopy slide, is autoclavable and sealed with a removable lid, which makes it suitable for use in a controlled culture environment. We describe in details how to build this chamber and we provide all the files necessary to print the different pieces in the lab.

  5. All-in-one 3D printed microscopy chamber for multidimensional imaging, the UniverSlide

    PubMed Central

    Alessandri, Kevin; Andrique, Laetitia; Feyeux, Maxime; Bikfalvi, Andreas; Nassoy, Pierre; Recher, Gaëlle

    2017-01-01

    While live 3D high resolution microscopy techniques are developing rapidly, their use for biological applications is partially hampered by practical difficulties such as the lack of a versatile sample chamber. Here, we propose the design of a multi-usage observation chamber adapted for live 3D bio-imaging. We show the usefulness and practicality of this chamber, which we named the UniverSlide, for live imaging of two case examples, namely multicellular systems encapsulated in sub-millimeter hydrogel shells and zebrafish larvae. We also demonstrate its versatility and compatibility with all microscopy devices by using upright or inverted microscope configurations after loading the UniverSlide with fixed or living samples. Further, the device is applicable for medium/high throughput screening and automatized multi-position image acquisition, providing a constraint-free but stable and parallelized immobilization of the samples. The frame of the UniverSlide is fabricated using a stereolithography 3D printer, has the size of a microscopy slide, is autoclavable and sealed with a removable lid, which makes it suitable for use in a controlled culture environment. We describe in details how to build this chamber and we provide all the files necessary to print the different pieces in the lab. PMID:28186188

  6. All-in-one 3D printed microscopy chamber for multidimensional imaging, the UniverSlide

    NASA Astrophysics Data System (ADS)

    Alessandri, Kevin; Andrique, Laetitia; Feyeux, Maxime; Bikfalvi, Andreas; Nassoy, Pierre; Recher, Gaëlle

    2017-02-01

    While live 3D high resolution microscopy techniques are developing rapidly, their use for biological applications is partially hampered by practical difficulties such as the lack of a versatile sample chamber. Here, we propose the design of a multi-usage observation chamber adapted for live 3D bio-imaging. We show the usefulness and practicality of this chamber, which we named the UniverSlide, for live imaging of two case examples, namely multicellular systems encapsulated in sub-millimeter hydrogel shells and zebrafish larvae. We also demonstrate its versatility and compatibility with all microscopy devices by using upright or inverted microscope configurations after loading the UniverSlide with fixed or living samples. Further, the device is applicable for medium/high throughput screening and automatized multi-position image acquisition, providing a constraint-free but stable and parallelized immobilization of the samples. The frame of the UniverSlide is fabricated using a stereolithography 3D printer, has the size of a microscopy slide, is autoclavable and sealed with a removable lid, which makes it suitable for use in a controlled culture environment. We describe in details how to build this chamber and we provide all the files necessary to print the different pieces in the lab.

  7. Univers: The construction of an internet-wide descriptive naming system

    NASA Technical Reports Server (NTRS)

    Bowman, C. Mic

    1990-01-01

    Descriptive naming systems allow clients to identify a set of objects by description. Described here is the construction of a descriptive naming system, called Univers, based on a model in which clients provide both an object description and some meta-information. The meta-information describes beliefs about the query and the naming system. Specifically, it is an ordering on a set of perfect world approximations, and it describes the preferred methods for accommodating imperfect information. The description is then resolved in a way that respects the preferred approximations.

  8. AmeriFlux US-UMB Univ. of Mich. Biological Station

    DOE Data Explorer

    Curtis, Peter [Ohio State University; Gough, Christopher [Virginia Commonwealth University

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-UMB Univ. of Mich. Biological Station. Site Description - The UMBS site is located within a protected forest owned by the University of Michigan. Arboreal composition of the forest consists of mid-aged northern hardwoods, conifer understory, aspen, and old growth hemlock. Logging of local white pines began in 1879. In successive years, several other species were harvested. Logging was discontinued in 1980 when the land became protected under the private ownership of the University of Michigan. Patchy low- to high-intensity wildfires occurred yearly from 1880 - 1920, essentially burning the entire region.

  9. Centre d'Observacio de l'Univers: first year of activities

    NASA Astrophysics Data System (ADS)

    Ribas, S. J.

    2011-11-01

    The Centre d'Observacio de l'Univers is one of the parts of the Parc Astronomic Montsec (PAM). PAM is an initiative of the Catalan government, through the Consorci del Montsec (Montsec Consortium), to take advantage of the capabilities and potential of the Montsec region to develop scientific research, training, and outreach activities, particularly in the field of astronomy. The choice of the Montsec mountains to install the PAM was motivated by the magnificent conditions for observing the sky at night; the sky above Montsec is the best (natural sky free of light pollution) in Catalonia for astronomical observations. The PAM has two main parts: the Observatori Astronomic del Montsec (OAdM) and the Centre d'Observacio del'Univers (COU). The OAdM is a professional observatory with an 80 cm catadioptric telescope (Joan Oro Telescope). The COU is a large multipurpose center which is intended to become an educational benchmark for teaching and communicate astronomy and other sciences in Catalonia. Since the opening more than 50000 visitors went to this center to enjoy science with Montsec dark skies and an special natural environment.

  10. Status Report and Lessons Learned from the Univ. of Arizona NMSD

    NASA Technical Reports Server (NTRS)

    Baiocchi, Dave; Burge, Jim

    2003-01-01

    We will present the latest generation of space mirror technology being developed at the Univ. of Arizona (UA). Unlike conventional monolithic mirrors, the UA mirrors are completely active in their operation. This allows greater flexibility in the mass, volume and performance specifications. The UA mirror design uses a thin flexible substrate for the optical surface and an actuated lightweight structure for surface accuracy and support. We provide an update on the UA NGST Mirror System Demonstrator (NMSD). The 2-m, f/5 NMSD mirror uses a 2 mm thick glass substrate and weighs 86 pounds. We review the mirror's design, discuss the mythology schemes used to actuate the figure, and present a list of the lessons learned.

  11. Cometas: Das Lendas aos Fatos

    NASA Astrophysics Data System (ADS)

    Voelzke, M. R.

    O descobrimento de cometas, devido ao seu aparecimento espetacular, tem registro nas mais antigas culturas humanas. A primeira referência situa-se no ano de 1095 antes de Cristo [a.C.; HO; HO, 1962]. A quantidade de registros de descobrimentos cometários, principalmente provenientes do território chinês em particular e do oriente em geral, aumentou gradualmente a partir do quarto século depois de Cristo (d.C.). É de origem chinesa a primeira referência ao cometa P/Halley no ano de 240 a.C. [VOELZKE, 1993]. Com o desenvolvimento da astronomia relativamente às técnicas observacionais os descobrimentos bem como as observações cometárias aumentaram sensivelmente a partir do século XVII, sendo que a partir do século XIX um novo incremento ocorreu devido ao emprego da fotografia e a resultante melhora de sensibilidade na observação.

  12. Aerosol Observing System (AOS) Handbook

    SciTech Connect

    Jefferson, A

    2011-01-17

    The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earth’s radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

  13. Transformation en ondelettes et applications en sciences de l'Univers

    NASA Astrophysics Data System (ADS)

    Bijaoui, A.

    2002-03-01

    La transformation en ondelettes est apparue au début des années 1980. Elle permet le déploiement de l'information en échelles. Cette transformation est bien adaptée à l'étude des structures hiérarchisées que nous montrent les images des astres. Elle peut être perçue comme résultant de l'analyse multirésolution, un banc de filtres ou une suite de filtrages passe-bande. Ces trois aspects sont successivement analysés. L'analyse résultante dérive de la notion de coefficients significatifs. Plusieurs types de bruit sont examinés. Diverses applications au traitement et à l'analyse des signaux et des images en sciences de l'univers sont passées en revue: compression des images, réduction du bruit, amélioration de la résolution, synthèse d'ouverture, détection des structures, analyse des signaux, vision multiéchelle et indicateurs statistiques.

  14. SRAO: the first southern robotic AO system

    NASA Astrophysics Data System (ADS)

    Law, Nicholas M.; Ziegler, Carl; Tokovinin, Andrei

    2016-08-01

    We present plans for SRAO, the first Southern Robotic AO system. SRAO will use AO-assisted speckle imaging and Robo-AO-heritage high efficiency observing to confirm and characterize thousands of planet candidates produced by major new transit surveys like TESS, and is the first AO system to be capable of building a comprehensive several-thousand-target multiplicity survey at sub-AU scales across the main sequence. We will also describe results from Robo-AO, the first robotic LGS-AO system. Robo-AO has observed tens of thousands of Northern targets, often using a similar speckle or Lucky-Imaging assisted mode. SRAO will be a moderate-order natural-guide-star adaptive optics system which uses an innovative photoncounting wavefront sensor and EMCCD speckle-imaging camera to guide on faint stars with the 4.1m SOAR telescope. The system will produce diffraction-limited imaging in the NIR on targets as faint as mν = 16. In AO-assisted speckle imaging mode the system will attain the 30-mas visible diffraction limit on targets at least as faint as mν = 17. The system will be the first Southern hemisphere robotic adaptive optics system, with overheads an order of magnitude smaller than comparable systems. Using Robo-AO's proven robotic AO software, SRAO will be capable of observing overheads on sub-minute scales, allowing the observation of at least 200 targets per night. SRAO will attain three times the angular resolution of the Palomar Robo-AO system in the visible.

  15. MagAO: status and science

    NASA Astrophysics Data System (ADS)

    Morzinski, Katie M.; Close, Laird M.; Males, Jared R.; Hinz, Phil M.; Esposito, Simone; Riccardi, Armando; Briguglio, Runa; Follette, Katherine B.; Pinna, Enrico; Puglisi, Alfio; Vezilj, Jennifer; Xompero, Marco; Wu, Ya-Lin

    2016-07-01

    "MagAO" is the adaptive optics instrument at the Magellan Clay telescope at Las Campanas Observatory, Chile. MagAO has a 585-actuator adaptive secondary mirror and 1000-Hz pyramid wavefront sensor, operating on natural guide stars from R-magnitudes of -1 to 15. MagAO has been in on-sky operation for 166 nights since installation in 2012. MagAO's unique capabilities are simultaneous imaging in the visible and infrared with VisAO and Clio, excellent performance at an excellent site, and a lean operations model. Science results from MagAO include the first ground-based CCD image of an exoplanet, demonstration of the first accreting protoplanets, discovery of a new wide-orbit exoplanet, and the first empirical bolometric luminosity of an exoplanet. We describe the status, report the AO performance, and summarize the science results. New developments reported here include color corrections on red guide stars for the wavefront sensor; a new field stop stage to facilitate VisAO imaging of extended sources; and eyepiece observing at the visible-light diffraction limit of a 6.5-m telescope. We also discuss a recent hose failure that led to a glycol coolant leak, and the recovery of the adaptive secondary mirror (ASM) after this recent (Feb. 2016) incident.

  16. Freva - Freie Univ Evaluation System Framework for Scientific Infrastructures in Earth System Modeling

    NASA Astrophysics Data System (ADS)

    Kadow, Christopher; Illing, Sebastian; Kunst, Oliver; Schartner, Thomas; Kirchner, Ingo; Rust, Henning W.; Cubasch, Ulrich; Ulbrich, Uwe

    2016-04-01

    The Freie Univ Evaluation System Framework (Freva - freva.met.fu-berlin.de) is a software infrastructure for standardized data and tool solutions in Earth system science. Freva runs on high performance computers to handle customizable evaluation systems of research projects, institutes or universities. It combines different software technologies into one common hybrid infrastructure, including all features present in the shell and web environment. The database interface satisfies the international standards provided by the Earth System Grid Federation (ESGF). Freva indexes different data projects into one common search environment by storing the meta data information of the self-describing model, reanalysis and observational data sets in a database. This implemented meta data system with its advanced but easy-to-handle search tool supports users, developers and their plugins to retrieve the required information. A generic application programming interface (API) allows scientific developers to connect their analysis tools with the evaluation system independently of the programming language used. Users of the evaluation techniques benefit from the common interface of the evaluation system without any need to understand the different scripting languages. Facilitation of the provision and usage of tools and climate data automatically increases the number of scientists working with the data sets and identifying discrepancies. The integrated web-shell (shellinabox) adds a degree of freedom in the choice of the working environment and can be used as a gate to the research projects HPC. Plugins are able to integrate their e.g. post-processed results into the database of the user. This allows e.g. post-processing plugins to feed statistical analysis plugins, which fosters an active exchange between plugin developers of a research project. Additionally, the history and configuration sub-system stores every analysis performed with the evaluation system in a database

  17. PSF reconstruction for AO photometry and astrometry

    NASA Astrophysics Data System (ADS)

    Ascenso, J.; Neichel, B.; Silva, M.; Fusco, T.; Garcia, P.

    2015-12-01

    Extracting accurate photometry (and astrometry) from images taken with adaptive optics assisted instruments is particularly challenging. Current post-processing tools are not prepared to achieve high accuracy from AO data, especially in limiting cases of crowded fields and marginally resolved sources. We quantify the limitations of these tools with synthetic images, and present a proof-of-concept study showing the potential of using reconstructed PSFs from the (GL)AO system telemetry to increase the measured photometric accuracy. We show that the photometric accuracy is significantly improved with a good PSF reconstruction in considerably crowded regions. We demonstrate the need for a dedicated post-processing tool that incorporates available information about the PSF, as well as the ability to adjust to the spatial variations of the PSF characteristic of AO data.

  18. Twelve thousand laser-AO observations: first results from the Robo-AO large surveys

    NASA Astrophysics Data System (ADS)

    Law, Nicholas M.; Baranec, Christoph; Riddle, Reed L.

    2014-07-01

    Robo-AO is the first AO system which can feasibly perform surveys of thousands of targets. The system has been operating in a fully robotic mode on the Palomar 1.5m telescope for almost two years. Robo-AO has completed nearly 12,000 high-angular-resolution observations in almost 20 separate science programs including exoplanet characterization, field star binarity, young star binarity and solar system observations. We summarize the Robo-AO surveys and the observations completed to date. We also describe the data-reduction pipeline we developed for Robo-AO—the first fully-automated AO data-reduction, point-spread-function subtraction and companion-search pipeline.

  19. Characterization of an AO-OCT system

    SciTech Connect

    Evans, J W; Zawadzki, R J; Jones, S; Olivier, S; Werner, J S

    2007-07-26

    Adaptive optics (AO) and optical coherence tomography (OCT) are powerful imaging modalities that, when combined, can provide high-volumetric-resolution, images of the retina. The AO-OCT system at UC Davis has been under development for 2 years and has demonstrated the utility of this technology for microscopic, volumetric, in vivo retinal imaging [1]. The current system uses an AOptix bimorph deformable mirror (DM) for low-order, high-stroke correction [2] and a 140-actuator Boston Micromachines DM for high-order correction [3]. We are beginning to investigate the potential for increasing the image contrast in this system using higher-order wavefront correction. The first step in this analysis is to quantify the residual wavefront error (WFE) in the current system. Developing an error budget is a common tool for improved performance and system design in astronomical AO systems [4, 5]. The process for vision science systems is also discussed in several texts e.g. [6], but results from this type of analysis have rarely been included in journal articles on AO for vision science. Careful characterization of the AO system will lead to improved performance and inform the design of a future high-contrast system. In general, an AO system error budget must include an analysis of three categories of residual WFE: errors in measuring the phase, errors caused by limitations of the DM(s), and errors introduced by temporal variation. Understanding the mechanisms and relative size of these errors is critical to improving system performance. In this paper we discuss the techniques for characterizing these error sources in the AO-OCT system. It is useful to first calculate an error budget for the simpler case using a model eye, and then add the additional errors introduced for the case of a human subject. Measurement error includes calibration error, wavefront sensor (WFS) CCD noise, and sampling errors. Calibration errors must be measured by an external system. Typically this

  20. MEMS DM development at Iris AO, Inc.

    NASA Astrophysics Data System (ADS)

    Helmbrecht, Michael A.; He, Min; Kempf, Carl J.; Besse, Marc

    2011-03-01

    Iris AO is actively developing piston-tip-tilt (PTT) segmented MEMS deformable mirrors (DM) and adaptive optics (AO) controllers for these DMs. This paper discusses ongoing research at Iris AO that has advanced the state-of-the-art of these devices and systems over the past year. Improvements made to open-loop operation and mirror fabrication enables mirrors to open-loop flatten to 4 nm rms. Additional testing of an anti snap-in technology was conducted and demonstrates that the technology can withstand 100 million snap-in events without failure. Deformable mirrors with dielectric coatings are shown that are capable of handling 630 W/cm2 of incident laser power. Over a localized region on the segment, the dielectric coatings can withstand 100kW/cm2 incident laser power for 30 minutes. Results from the first-ever batch of PTT489 DMs that were shipped to pilot customers are reported. Optimizations made to the open-loop PTT controller are shown to have latencies of 157.5 μs and synchronous array update rates of nearly 6.5 kHz. Finally, plans for the design and fabrication of the next-generation PTT939 DM are presented.

  1. Experimental study on the thorium-loaded accelerator-driven system at the Kyoto Univ. critical assembly

    SciTech Connect

    Pyeon, C. H.; Yagi, T.; Lim, J. Y.; Misawa, T.

    2012-07-01

    The experimental study on the thorium-loaded accelerator-driven system (ADS) is conducted in the Kyoto Univ. Critical Assembly (KUCA). The experiments are carried out in both the critical and subcritical states for attaining the reaction rates of the thorium capture and fission reactions. In the critical system, the thorium plate irradiation experiment is carried out for the thorium capture and fission reactions. From the results of the measurements, the thorium fission reactions are obtained apparently in the critical system, and the C/E values of reaction rates show the accuracy of relative difference of about 30%. In the ADS experiments with 14 MeV neutrons and 100 MeV protons, the subcritical experiments are carried out in the thorium-loaded cores to obtain the capture reaction rates through the measurements of {sup 115}In(n, {gamma}){sup 116m}In reactions. The results of the experiments reveal the difference between the reaction rate distributions for the change in not only the neutron spectrum but also the external neutron source. The comparison between the measured and calculated reaction rate distributions demonstrates a discrepancy of the accuracy of reaction rate analyses of thorium capture reactions through the thorium-loaded ADS experiments with 14 MeV neutrons. Hereafter, kinetic experiments are planned to be carried out to deduce the delayed neutron decay constants and subcriticality using the pulsed neutron method. (authors)

  2. Deformable mirror designs for extreme AO (XAO)

    NASA Astrophysics Data System (ADS)

    Cavaco, Jeffrey; Wirth, Allan

    2014-08-01

    One of the science missions for the next generation of extremely large ground based telescopes (30-42m apertures) is the imaging and spectroscopy of exoplanets. To achieve that goal an Adaptive Optics (AO) subsystem with a very large number of corrected modes is required. To provide contrast ratios in the range of 10-9 or better for a 42m telescope an AO system with 25,000 to 60,000 channels will be needed. This is approximately an order of magnitude beyond the current state of the art. Adaptive Optics Associates Xinetics has developed the Photonex Module Deformable Mirror (DM) technology specifically to address the needs of extreme AO for high contrast applications. A Photonex Module is a monolithic block of electrostrictive ceramic in which a high density of individually addressable actuators are formed by screen printing of electrodes and partial wire saw cutting of the ceramic. The printed electrode structures also allow all electrical connections to be made at the back surface of the module via flex circuits. Actuator spacings of 1mm or less have been achieved using this approach. The individual modules can be edge butted and bonded to achieve high actuator count. The largest DMs fabricated to date have 4096 actuators in a 64X64mm array. In this paper the engineering challenges in extending this technology by a factor of ten or more in actuator count will be discussed. A conceptual design for a DM suitable for XAO will be presented. Approaches for a support structure that will maintain the low spatial frequency surface figure of this large (~0.6m) DM and for the electrical interface to the tens of thousands of actuators will be discussed. Finally, performance estimates will be presented.

  3. AO corrected satellite imaging from Mount Stromlo

    NASA Astrophysics Data System (ADS)

    Bennet, F.; Rigaut, F.; Price, I.; Herrald, N.; Ritchie, I.; Smith, C.

    2016-07-01

    The Research School of Astronomy and Astrophysics have been developing adaptive optics systems for space situational awareness. As part of this program we have developed satellite imaging using compact adaptive optics systems for small (1-2 m) telescopes such as those operated by Electro Optic Systems (EOS) from the Mount Stromlo Observatory. We have focused on making compact, simple, and high performance AO systems using modern high stroke high speed deformable mirrors and EMCCD cameras. We are able to track satellites down to magnitude 10 with a Strehl in excess of 20% in median seeing.

  4. AO Observations of Three Powerful Radio Galaxies

    SciTech Connect

    de Vries, W; van Bruegel, W; Quirrenbach, A

    2002-08-01

    The host galaxies of powerful radio sources are ideal laboratories to study active galactic nuclei (AGN). The galaxies themselves are among the most massive systems in the universe, and are believed to harbor supermassive black holes (SMBH). If large galaxies are formed in a hierarchical way by multiple merger events, radio galaxies at low redshift represent the end-products of this process. However, it is not clear why some of these massive ellipticals have associated radio emission, while others do not. Both are thought to contain SMBHs, with masses proportional to the total luminous mass in the bulge. It either implies every SMBH has recurrent radio-loud phases, and the radio-quiet galaxies happen to be in the ''low'' state, or that the radio galaxy nuclei are physically different from radio-quiet ones, i.e. by having a more massive SMBH for a given bulge mass. Here we present the first results from our adaptive optics imaging and spectroscopy pilot program on three nearby powerful radio galaxies. Initiating a larger, more systematic AO survey of radio galaxies (preferentially with Laser Guide Star equipped AO systems) has the potential of furthering our understanding of the physical properties of radio sources, their triggering, and their subsequent evolution.

  5. Diferentes Metodologias Aplicadas ao Ensino de Astronomia

    NASA Astrophysics Data System (ADS)

    Albrecht, E.; Voelzke, M. R.

    2007-08-01

    Espera-se que o educando ao final da educação básica, adquira uma compreensão atualizada das hipóteses, modelos e formas de investigação sobre a origem e evolução do Universo em que vive. O presente trabalho tem como principal objetivo compreender dentre três práticas pedagógicas adotadas no Ensino de Astronomia, na terceira série do Ensino Médio, da Escola Estadual Colônia dos Pescadores, qual melhor cumpre o papel de formação e aprendizagem para vida. A pesquisa preliminar foi através de um questionário onde o intuito foi diagnosticar o conhecimento já existente acerca do tema em questão. O questionário é composto de vinte questões dissertativas e objetivas, onde os educandos das três turmas envolvidas o responderam. Este trabalho utiliza as seguintes metodologias: a tradicional, onde o professor é um repassador de informações, fazendo uso exclusivo de lousa e giz; a segunda também de forma tradicional, porém com auxílio de multimídia para desenvolvimento das aulas e aterceira sob forma de seminários, elaborados e apresentados pelos educandos, no qual o educador faz apenas as intervenções necessárias. Ao final do trabalho os alunos responderão novamente o questionário inicial para diagnosticar dentre as três metodologias utilizadas qual apresentou melhor resultado. Os resultados preliminares obtidos, já podem ser observados e, dos 119 alunos entrevistados, as respostas obtidas são as mais diversas e evidenciam que a grande maioria nunca teve em sua vida escolar o tema Astronomia. Ao serem questionados se já haviam estudado Astronomia as respostas foram: turma A: sim 43%; turma B: sim: 21%; turma C: sim: 24%. Porém quando questionados a respeito do significado de Astronomia observou-se que: turma A: 100% de acertos; turma B: 64% acertos; turma C: 84% de acertos, demonstrando claramente a aprendizagem em diferentes esferas, não dependendo unicamente da escola. Até o presente momento, verificou-se que há interesse em

  6. AO Infrared Imaging of M71 Core

    NASA Astrophysics Data System (ADS)

    Ruberg, Andres; Richer, H.; Brewer, J.; Davis, S.; Hickson, P.; Knigge, C.; Dieball, A.; Hurley, J.; Shara, M.; Hansen, B.; Gebhardt, K.; Fahlman, G.

    2007-05-01

    In this poster we present infrared H and K AO data taken with ALTAIR/NIRI on Gemini North of the globular cluster Messier 71. This data represents approximately 22ks of observations in H and 17ks in K, in a field 22x22 arcsec centered on the core of the cluster. These data were secured under superb conditions and will provide an excellent opportunity to pursue our scientific goals. These goals include the observation of the end of hydrogen-burning main sequence in a moderately metal-rich globular cluster and, by fitting the brightness profile and looking for deviations from a King model, we will search for evidence for a central black hole in this cluster.

  7. LGS-AO Imaging of Every Kepler Planet Candidate: the Robo-AO KOI Survey

    NASA Astrophysics Data System (ADS)

    Baranec, Christoph; Law, Nicholas; Morton, Timothy; Ziegler, Carl; Nofi, Larissa; Atkinson, Dani; Riddle, Reed

    2015-12-01

    The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star with laser adaptive optics imaging, to search for blended nearby stars which may be physically associated companions and/or responsible for transit false positives. We will present the results from searching for companions around over 3,000 Kepler planet hosts in 2012-2015. We will describe our first data release covering 715 planet candidate hosts, and give a preview of ongoing results including improved statistics on the likelihood of false positive planet detections in the Kepler dataset, many new planets in multiple star systems, and new exotic multiple star systems containing Kepler planets. We will also describe the automated Robo-AO survey data reduction methods, including a method of using the large ensemble of target observations as mutual point-spread-function references, along with a new automated companion-detection algorithm designed for extremely large adaptive optics surveys. Our first data release covered 715 objects, searching for companions from 0.15” to 2.5” separation with contrast up to 6 magnitudes. We measured the overall nearby-star-probability for Kepler planet candidates to be 7.4+/-1.0%, and we will detail the variations in this number with stellar host parameters. We will also discuss plans to extend the survey to other transiting planet missions such as K2 and TESS as Robo-AO is in the process of being re-deployed to the 2.1-m telescope at Kitt Peak for 3 years and a higher-contrast Robo-AO system is being developed for the 2.2-m UH telescope on Maunakea.

  8. Review of AO calibrations, or how to best educate your AO system

    NASA Astrophysics Data System (ADS)

    Kolb, Johann

    2016-07-01

    If the Real-Time Computer is the heart of an AO system, the Wavefront Sensor (WFS) its eyes, the Deformable Mirror (DM) its hands and the control strategy its nervous system, the sum of all those parts is made into a harmonious entity thanks to calibrations. This paper does not have the ambition to provide an overview of all the currently existing calibration strategies, but rather to focus on a few challenging problems and their recent evolution in the era of adaptive telescopes, mostly based on the experience of ESO's Adaptive Optics Instruments in general and the AO Facility in particular. Single most important calibration in post-focal AO system, the recording of the Interaction Matrix (IM) between WFS and DM has since long evolved to use fast modulation techniques, has shown to be feasible on-sky and is now almost free from measurements thanks to its pseudo-synthetic generation, quasi-mandatory solution in an adaptive telescope. Pseudo- because it requires an unprecedented knowledge of the components' characteristics, especially the WFS, DM and the optical registration between the two. Bigger telescopes and the use of Laser Guide Stars (LGS) also mean that the properties of the system will change in time and thus need to be constantly updated thanks to online diagnosis tools for spot size measurement, atmosphere monitoring, Wavefront Sensing and control optimization. New loops come into play like the one to minimize LGS Jitter and the one taking over the telescope active optics by means of offloading the DM low orders, and they all require calibration. More calibration means more time and one has to carefully balance the calibrations that require precious telescope night time, day time or for the best, no telescope time at all. Their importance sometimes underestimated, calibrations have repeatedly shown to be a vital part in the optimum functioning of present and future AO systems.

  9. Directly Imaging Planets with SCExAO: First Results

    NASA Astrophysics Data System (ADS)

    Currie, Thayne M.; Guyon, Olivier; Jovanovic, Nemanja; Lozi, Julien; Tamura, Motohide; Kudo, Tomoyuki; Uyama, Taichi; Garcia, Eugenio

    2017-01-01

    We present the first science results from the newly commissioned Subaru Coronagraphic Extreme Adaptive Optics project, an experimental system dedicated to image faint jovian planets around nearby stars. SCExAO is now achieving true extreme AO capability. We describe the typical performance of SCExAO, the first images of benchmark exoplanets and planet-forming disks, and SCExAO’s first science results. Finally, we briefly chart the path forward for SCExAO to achieve its full scientific capability, including imaging mature planets in reflected light.

  10. Electromagnetic DM technology meets future AO demands

    NASA Astrophysics Data System (ADS)

    Hamelinck, Roger; Rosielle, Nick; Steinbuch, Maarten; Doelman, Niek

    New deformable mirror technology is developed by the Technische Universiteit Eindhoven, Delft University of Technology and TNO Science and Industry. Several prototype adaptive deformable mirrors are realized mirrors, up to 427 actuators and ∅150mm diameter, with characteristics suitable for future AO systems. The prototypes consist of a 100µm thick, continuous facesheet on which low voltage, electromagnetic, push-pull actuators impose out-of-plane displacements. The variable reluctance actuators with ±10µm stroke and nanometer resolution are located in a standard actuator module. Each module with 61 actuators connects to a single PCB with dedicated, 16 bit, PWM based, drivers. A LVDS multi-drop cable connects up to 32 actuator modules. With the actuator module, accompanying PCB and multi-drop system the deformable mirror technology is made modular in its mechanics and electronics. An Ethernet-LVDS bridge enables any commercial PC to control the mirror using the UDP standard. Latest results of the deformable mirror technology development are presented.

  11. NFIRAOS Multiconjugate AO System for TMT

    NASA Astrophysics Data System (ADS)

    Herriot, Glen; Andersen, David; Atwood, Jenny; Byrnes, Peter; Boyer, Corinne; Caputa, Kris; Correia, Carlos; Dunn, Jennifer; Ellerbroek, Brent; Fitzsimmons, Joeleff; Gilles, Luc; Hickson, Paul; Hill, Alexis; Pazder, John; Reshetov, Vlad; Smith, Malcolm; Véran, Jean-Pierre; Wang, Lianqi; Wevers, Ivan

    2011-09-01

    NFIRAOS, the Adaptive Optics system for the Thirty Meter Telescope, is a Multiconjugate Adaptive Optics System of order 60x60 with two deformable mirrors and six laser guide star wavefront sensors. NFIRAOS is 8 x 10 x 5 m (L x W x H) on a Nasmyth Platform and supports three client instruments operating over 0.8 - 2.5 μm wavelength range. In this paper we discuss: NFIRAOS' requirements and architecture; changes to NFIRAOS since the last AO4ELT conference; interior details of NFIRAOS; interfaces to instruments; integration and verification plans. Top-level science requirements include 50% sky coverage at the galactic pole with <187 nm wavefront error. Astrometry is an important science driver - to minimize image distortion, we have recently revised the optical design to use four off-axis paraboloidal mirrors. We have vastly simplified the laser WFS zoom optics and moved them inside the cold enclosure. To control image magnification, differential magnification and tip/tilt/focus, NFIRAOS' client instruments have three low-order warfront sensors monitoring near-infrared natural guide stars. These stars are sharpened by NFIRAOS, which assists sky coverage. NFIRAOS will have high throughput and low thermal background - it will be cooled to -30 °C. The insulated walls have a buried cold plate to intercept heat leakage and isothermalize the interior of NFIRAOS. Instruments have stringent requirements on heat leakage and must provide their own rotator and interface to NFIRAOS, including a rotating seal. For wavelength and flat field calibration of client instruments, a NFIRAOS Science Calibration Unit (NSCU) feeds light in the entrance window, through NFIRAOS, to instruments. Inside NFIRAOS are deployable light sources simulating natural and laser guide stars, a focal plane mask with pinholes illuminated by the NSCU, as well as a turbulence phase screen. A prototype screen has been manufactured by magneto-rheological machining. We are currently updating the NFIRAOS

  12. WIYN active optics: a platform for AO

    NASA Astrophysics Data System (ADS)

    Code, Arthur D.; Claver, Charles F.; Goble, Larry W.; Jacoby, George H.; Sawyer, David G.

    1998-09-01

    The WIYN 3.5 meter telescope is situated on the southwest ridge of Kitt Peak yielding excellent atmosphere seeing conditions. As such, the telescope and enclosure design was directed towards exploiting this feature. The primary mirror was spun cast and figured by the Steward Observatory Mirror Laboratory and the secondary mirror by Contraves. In both cases the performance exceeded the design specifications. The borosilicate primary is actively temperature controlled to within 0.2 C of the desired temperature, typically 0.5 degrees C below the ambient air. The telescope structure is also temperature controlled and the enclosure is opened to the outside ion all sides, which all heat sources are vented to ducts carrying air downwind of the facility. The primary mirror is actively controlled for low order aberrations by 66 axial actuators which are adjusted open loop via force matrix look-up tables and closed loop via real-time wavefront curvature sensing measurements. The active optics also included real-time collimation and focus control. The telescope drive and guider are capable of providing tracking to a few hundredths of a second of arc. By employing active telescope control at this level, it is possible to maintain telescope and local wavefront distortion to a level where atmospheric effects dominate the image quality. Since a significant fraction of the power in the atmospheric disturbances is contained in image motion the first step in adaptive optics control will be simple tip tilt. Studies of higher order AO system are being carried out, as well as additional test characterizing the telescope and site. It is intended to continue such studies in an attempt to establish long term variances.

  13. Robo-AO: Performance and Characterization at Palomar Observatory

    NASA Astrophysics Data System (ADS)

    Tendulkar, Shriharsh P.; Baranec, C.; Riddle, R. L.; Ramaprakash, A. N.; Law, N. M.; Kulkarni, S. R.; Dekany, R.; Bui, K.; Davis, J.; Burse, M.; Das, H.; Punnadi, S.; Chordia, P.

    2013-01-01

    Hosted at the Palomar 60-inch telescope, Robo-AO is the world's first completely autonomous, laser-beacon supported adaptive optics (AO) system, delivering diffraction-limited images in the visible and IR wavelengths. With simultaneous turbulence monitoring using a MASS-DIMM instrument, we have characterized the performance of Robo-AO as a function of local seeing, turbulence profile, laser return power and the brightness of the tip-tilt star. We shall present the various AO metrics: The full-width at half maxima of the point spread function, the Strehl ratio, the isoplanatic angle and their variations with the atmospheric and operating conditions. Strategies for optimizing robotic AO observations based on varying conditions will be discussed.

  14. The path to visible extreme adaptive optics with MagAO-2K and MagAO-X

    NASA Astrophysics Data System (ADS)

    Males, Jared R.; Close, Laird M.; Guyon, Olivier; Morzinski, Katie M.; Hinz, Philip; Esposito, Simone; Pinna, Enrico; Xompero, Marco; Briguglio, Runa; Riccardi, Armando; Puglisi, Alfio; Mazin, Ben; Ireland, Michael J.; Weinberger, Alycia; Conrad, Al; Kenworthy, Matthew; Snik, Frans; Otten, Gilles; Jovanovic, Nemanja; Lozi, Julien

    2016-07-01

    The next generation of extremely large telescopes (ELTs) have the potential to image habitable rocky planets, if suitably optimized. This will require the development of fast high order "extreme" adaptive optics systems for the ELTs. Located near the excellent site of the future GMT, the Magellan AO system (MagAO) is an ideal on-sky testbed for high contrast imaging development. Here we discuss planned upgrades to MagAO. These include improvements in WFS sampling (enabling correction of more modes) and an increase in speed to 2000 Hz, as well as an H2RG detector upgrade for the Clio infrared camera. This NSF funded project, MagAO-2K, is planned to be on-sky in November 2016 and will significantly improve the performance of MagAO at short wavelengths. Finally, we describe MagAO-X, a visible-wavelength extreme-AO "afterburner" system under development. MagAO-X will deliver Strehl ratios of over 80% in the optical and is optimized for visible light coronagraphy.

  15. AO 0235+164 and Surrounding Field: Surprising HST Results

    NASA Technical Reports Server (NTRS)

    Burbidge, E. M.; Beaver, E. A.; Cohen, Ross D.; Junkkarinen, V. T.; Lyons, R. W.

    1996-01-01

    Results obtained with the Hubble Space Telescope on the highly variable radio, x-ray, and gamma-ray emitting QSO (or BL Lac object) AO 0235 + 164 are presented and analyzed. WFPC2 images were obtained in 1994 June, when AO 0235 + 164 was bright (m approx. 17), and the results are described in Sec. 3. After subtraction of the PSF of the QSO, hereafter called AO following the nomenclature of Yanny et al. (1989), the companion object named A, 2 sec south of AO, is discovered not to be an elliptical galaxy as hypothesized earlier, but to be an AGN object, with a central UV-bright point-source nucleus and faint surrounding nebulosity extending to AO. The second companion object 1.3 sec east of AO discovered by Yanny et al. (1989) and named object Al, appears more like a normal spiral galaxy. We have measured the positions, luminosities, and colors of some 30 faint objects in the field around AO 0235 + 16; most are extended and may be star-forming galaxies in a loose group or cluster. Our most surprising result of the HST observations comes from FOS spectra obtained in 1995 July, discussed in Sec. 4. Because of a positioning error of the telescope and AO's faintness at that time (m approx. 20), object A was observed instead of the intended target AO. Serendipitously, we discovered A to have broad deep BALQSO-type absorptions of C IV, Si IV, N V shortward of broad emissions. A is thus ejecting high velocity, highly ionized gas into the surrounding IGM. We discuss in Sec. 5 the relationship of the objects in the central 10 sec X 1O sec region around AO, where redshifts z(sub e) = 0.94, z(sub a) = 0.524, 0.851 in AO, (sub e) = 0.524 and Z(sub BAL)=0.511 in A, are found. We hypothesize that some of the 30 faint objects in the 77 sec. x 77 sec. field may be part of a large star-forming region at z approx. 0.5, as suggested for a few objects by Yanny et al. (1989). The proximity of two highly active extragalactic objects, AO 0235+164 and its AGN companion A, is remarkable and

  16. The Subaru Coronagraphic Extreme AO Project: Progress and Upgrades

    NASA Astrophysics Data System (ADS)

    Jovanovic, Nemanja; Martinache, F.; Guyon, O.; Clergeon, C.; Garrel, V.

    2013-01-01

    The Subaru Coronagraphic Extreme AO (SCExAO) instrument consists of a high performance Phase Induced Amplitude Apodisation (PIAA) coronagraph combined with an extreme Adaptive Optics (AO) system operating in the near-infrared (H band). The extreme AO system driven by the 2000 element deformable mirror will allow for Strehl ratios>90% to be achieved in the H-band when it goes closed loop. This makes the SCExAO instrument a powerful platform for high contrast imaging down to angular separations of the order of 1 λ/D. In this paper we report on the recent progress in regards to the development of the instrument, which includes the addition of a visible bench that makes use of the light at shorter wavelengths not currently utilized by SCExAO and closing the loop on the tip/tilt wavefront sensor. We will also discuss two exciting guest instruments which will expand the capabilities of SCExAO over the next few years; namely CHARIS which is a integral field spectrograph as well as VAMPIRES, a visible aperture masking experiment based on polarimetric analysis of circumstellar disks.

  17. SCExAO: First Results and On-Sky Performance

    NASA Astrophysics Data System (ADS)

    Currie, Thayne; Guyon, Olivier; Martinache, Frantz; Clergeon, Christophe; McElwain, Michael; Thalmann, Christian; Jovanovic, Nemanja; Singh, Garima; Kudo, Tomoyuki

    2014-01-01

    We present new on-sky results for the Subaru Coronagraphic Extreme Adaptive Optics imager (SCExAO) verifying and quantifying the contrast gain enabled by key components: the closed-loop coronagraphic low-order wavefront sensor (CLOWFS) and focal plane wavefront control (``speckle nulling''). SCExAO will soon be coupled with a high-order, Pyramid wavefront sensor which will yield > 90% Strehl ratio and enable 106-107 contrast at small angular separations allowing us to image gas giant planets at solar system scales. Upcoming instruments like VAMPIRES, FIRST, and CHARIS will expand SCExAO's science capabilities.

  18. SCExAO: First Results and On-Sky Performance

    NASA Technical Reports Server (NTRS)

    Currie, Thayne; Guyon, Olivier; Martinache, Frantz; Clergeon, Christophe; McElwain, Michael; Thalmann, Christian; Jovanovic, Nemanja; Singh, Garima; Kudo, Tomoyuki

    2013-01-01

    We present new on-sky results for the Subaru Coronagraphic Extreme Adaptive Optics imager (SCExAO) verifying and quantifying the contrast gain enabled by key components: the closed-loop coronagraphic low-order wavefront sensor (CLOWFS) and focal plane wavefront control ("speckle nulling"). SCExAO will soon be coupled with a high-order, Pyramid wavefront sensor which will yield greater than 90% Strehl ratio and enable 10(exp 6) -10(exp 7) contrast at small angular separations allowing us to image gas giant planets at solar system scales. Upcoming instruments like VAMPIRES, FIRST, and CHARIS will expand SCExAO's science capabilities.

  19. The Robo-AO automated intelligent queue system

    NASA Astrophysics Data System (ADS)

    Riddle, Reed L.; Hogstrom, Kristina; Papadopoulos, Athanasios; Baranec, Christoph; Law, Nicholas M.

    2014-07-01

    Robo-AO is the first automated laser adaptive optics instrument. In just its second year of scientific operations, it has completed the largest adaptive optics surveys to date, each comprising thousands of targets. Robo-AO uses a fully automated queue scheduling system that selects targets based on criteria entered on a per observing program or per target basis, and includes the ability to coordinate with US Strategic Command automatically to avoid lasing space assets. This enables Robo-AO to select among thousands of targets at a time, and achieve an average observation rate of approximately 20 targets per hour.

  20. LGS-AO Imaging of Every Kepler Planet Candidate: the Robo-AO KOI Survey

    NASA Astrophysics Data System (ADS)

    Law, Nicholas Michael; Baranec, Christoph; Morton, Timothy; Ziegler, Carl; Atkinson, Dani; Riddle, Reed

    2015-08-01

    The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star with laser adaptive optics imaging, to search for blended nearby stars which may be physically associated companions and/or responsible for transit false positives. We will present the results from searching for companions around over 3,000 Kepler planet hosts in 2012-2015. We will describe our first data release covering 715 planet candidate hosts, and give a preview of ongoing results including improved statistics on the likelihood of false positive planet detections in the Kepler dataset, many new planets in multiple star systems, and new exotic multiple star systems containing Kepler planets.We will also describe the automated Robo-AO survey data reduction methods, including a method of using the large ensemble of target observations as mutual point-spread-function references, along with a new automated companion-detection algorithm designed for extremely large adaptive optics surveys.Our first data release covered 715 objects, searching for companions from 0.15” to 2.5” separation with contrast up to 6 magnitudes. We measured the overall nearby-star-probability for Kepler planet candidates to be 7.4+/-1.0%, and we will detail the variations in this number with stellar host parameters. We will also discuss several KOIs of particular interest, including KOI-191 and KOI-1151, which are both multi-planet systems with detected stellar companions whose unusual planetary system architecture might be best explained if they are ``coincident multiple'' systems, with several transiting planets shared between the two stars. Finally, we will discuss and update the 98%-confidence evidence from our survey that third bodies in star/planet systems produce an excess of close-in giant planets.

  1. Real-time processing for the ATST AO system

    NASA Astrophysics Data System (ADS)

    Richards, K.; Rimmele, T.

    The real-time processing requirements for the four meter Advanced Technology Solar Telescope extended source high order adaptive optics system will be approximately 15 times that of the Dunn Solar Telescope AO systems on which the ATST AO system is based. The ATST AO, with its approximately 1232 subapertures, will use massively parallel processing and is based on Analog Devices TigerSHARC DSPs as the central processing units. We will discuss the requirements for processing and data handling and the architecture of the correlating Shack-Hartmannn and reconstructor processing unit and present the results of bench-mark testing of the DSP hardware that was selected for the ATST AO system.

  2. Visible AO Observations at Halpha for Accreting Young Planets

    NASA Astrophysics Data System (ADS)

    Close, L. M.; Follette, K.; Males, J. R.; Morzinski, K.; Rodigas, T. J.; Hinz, P.; Wu, Y.-L.; Apai, D.; Najita, J.; Puglisi, A.; Esposito, S.; Riccardi, A.; Bailey, V.; Xompero, M.; Briguglio, R.; Weinberger, A.

    2014-01-01

    We utilized the new high-order (250-378 mode) Magellan Adaptive Optics system (MagAO) to obtain very high-resolution science in the visible with MagAO's VisAO CCD camera. In the good-median seeing conditions of Magellan (0.5-0.7'') we find MagAO delivers individual short exposure images as good as 19 mas optical resolution. Due to telescope vibrations, long exposure (60s) r' (0.63μm) images are slightly coarser at FWHM = 23-29 mas (Strehl ~ 28%) with bright (R < 9 mag) guide stars. These are the highest resolution filled-aperture images published to date. Images of the young (~ 1 Myr) Orion Trapezium θ1 Ori A, B, and C cluster members were obtained with VisAO. In particular, the 32 mas binary θ1 Ori C 1 C 2 was easily resolved in non-interferometric images for the first time. Relative positions of the bright trapezium binary stars were measured with ~ 0.6-5 mas accuracy. In the second commissioning run we were able to correct 378 modes and achieved good contrasts (Strehl>20% on young transition disks at Hα). We discuss the contrasts achieved at Hα and the possibility of detecting low mass (~ 1-5 Mjup) planets (past 5AU) with our new SAPPHIRES survey with MagAO at Hα.

  3. Beyond the Blur: Construction and Characterization of the First Autonomous AO System, and, An AO Survey of Magnetar Proper Motions

    NASA Astrophysics Data System (ADS)

    Tendulkar, Shriharsh Prakash

    Adaptive optics (AO) corrects distortions created by atmospheric turbulence and delivers diffraction-limited images on ground-based telescopes. The vastly improved spatial resolution and sensitivity has been utilized for studying everything from the magnetic fields of sunspots upto the internal dynamics of high-redshift galaxies. This thesis about AO science from small and large telescopes is divided into two parts: Robo-AO and magnetar kinematics. In the first part, I discuss the construction and performance of the world's first fully autonomous visible light AO system, Robo-AO, at the Palomar 60-inch telescope. Robo-AO operates extremely efficiently with an overhead < 50s, typically observing about 22 targets every hour. We have performed large AO programs observing a total of over 7,500 targets since May 2012. In the visible band, the images have a Strehl ratio of about 10% and achieve a contrast of upto 6 magnitudes at a separation of 1‧‧. The full-width at half maximum achieved is 110-130 milli-arcsecond. I describe how Robo-AO is used to constrain the evolutionary models of low-mass pre-main-sequence stars by measuring resolved spectral energy distributions of stellar multiples in the visible band, more than doubling the current sample. I conclude this part with a discussion of possible future improvements to the Robo-AO system. In the second part, I describe a study of magnetar kinematics using high-resolution near-infrared (NIR) AO imaging from the 10-meter Keck II telescope. Measuring the proper motions of five magnetars with a precision of upto 0.7 milli-arcsecond/yr -1, we have more than tripled the previously known sample of magnetar proper motions and proved that magnetar kinematics are equivalent to those of radio pulsars. We conclusively showed that SGR 1900+14 and SGR 1806-20 were ejected from the stellar clusters with which they were traditionally associated. The inferred kinematic ages of these two magnetars are 6 +/- 1.8 kyr and 650 +/-3 00

  4. Characterizing and mitigating vibrations for SCExAO

    NASA Astrophysics Data System (ADS)

    Lozi, Julien; Guyon, Olivier; Jovanovic, Nemanja; Singh, Garima; Goebel, Sean; Norris, Barnaby; Okita, Hirofumi

    2016-07-01

    The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument, under development for the Subaru Telescope, has currently the fastest on-sky wavefront control loop, with a pyramid wavefront sensor running at 3.5 kHz. But even at that speed, we are still limited by low-frequency vibrations. The current main limitation was found to be vibrations attributed mainly to the rotation of the telescope. Using the fast wavefront sensors, cameras and accelerometers, we managed to identify the origin of most of the vibrations degrading our performance. Low-frequency vibrations are coming from the telescope drive in azimuth and elevation, as well as the elevation encoders when the target is at transit. Other vibrations were found at higher frequency coming from the image rotator inside Subaru's adaptive optics facility AO188. Different approaches are being implemented to take care of these issues. The PID control of the image rotator has been tuned to reduce their high-frequency contribution. We are working with the telescope team to tune the motor drives and reduce the impact of the elevation encoder. A Linear Quadratic Gaussian controller (LQG, or Kalman filter) is also being implemented inside SCExAO to control these vibrations. These solutions will not only improve significantly SCExAOs performance, but will also help all the other instruments on the Subaru Telescope, especially the ones behind AO188. Ultimately, this study will also help the development of the TMT, as these two telescopes share very similar drives.

  5. Second generation Robo-AO instruments and systems

    NASA Astrophysics Data System (ADS)

    Baranec, Christoph; Riddle, Reed; Law, Nicholas M.; Chun, Mark R.; Lu, Jessica R.; Connelley, Michael S.; Hall, Donald; Atkinson, Dani; Jacobson, Shane

    2014-07-01

    The prototype Robo-AO system at the Palomar Observatory 1.5-m telescope is the world's first fully automated laser adaptive optics instrument. Scientific operations commenced in June 2012 and more than 12,000 observations have since been performed at the ~0.12" visible-light diffraction limit. Two new infrared cameras providing high-speed tip-tilt sensing and a 2' field-of-view will be integrated in 2014. In addition to a Robo-AO clone for the 2-m IGO and the natural guide star variant KAPAO at the 1-m Table Mountain telescope, a second generation of facility-class Robo-AO systems are in development for the 2.2-m University of Hawai'i and 3-m IRTF telescopes which will provide higher Strehl ratios, sharper imaging, ~0.07", and correction to λ = 400 nm.

  6. Initial Performance of the Keck AO Wavefront Controller System

    SciTech Connect

    Johansson, E M; Acton, D S; An, J R; Avicola, K; Beeman, B V; Brase, J M; Carrano, C J; Gathright, J; Gavel, D T; Hurd, R L; Lai, O; Lupton, W; Macintosh, B A; Max, C E; Olivier, S S; Shelton, J C; Stomski, P J; Tsubota, K; Waltjen, K E; Watson, J A; Wizinowich, P L

    2001-03-01

    The wavefront controller for the Keck Observatory AO system consists of two separate real-time control loops: a tip-tilt control loop to remove tilt from the incoming wavefront, and a deformable mirror control loop to remove higher-order aberrations. In this paper, we describe these control loops and analyze their performance using diagnostic data acquired during the integration and testing of the AO system on the telescope. Disturbance rejection curves for the controllers are calculated from the experimental data and compared to theory. The residual wavefront errors due to control loop bandwidth are also calculated from the data, and possible improvements to the controller performance are discussed.

  7. High-Performance CCSDS AOS Protocol Implementation in FPGA

    NASA Technical Reports Server (NTRS)

    Clare, Loren P.; Torgerson, Jordan L.; Pang, Jackson

    2010-01-01

    The Consultative Committee for Space Data Systems (CCSDS) Advanced Orbiting Systems (AOS) space data link protocol provides a framing layer between channel coding such as LDPC (low-density parity-check) and higher-layer link multiplexing protocols such as CCSDS Encapsulation Service, which is described in the following article. Recent advancement in RF modem technology has allowed multi-megabit transmission over space links. With this increase in data rate, the CCSDS AOS protocol implementation needs to be optimized to both reduce energy consumption and operate at a high rate.

  8. Initial performance of the Keck AO wavefront controller system

    NASA Astrophysics Data System (ADS)

    Johansson, Erik M.; Acton, D. Scott; An, Jong R.; Avicola, Kenneth; Beeman, Bart V.; Brase, James M.; Carrano, Carmen J.; Gathright, John; Gavel, Donald T.; Hurd, Randall L.; Lai, Olivier; Lupton, William; Macintosh, Bruce A.; Max, Claire E.; Olivier, Scot S.; Shelton, J. Christopher; Stomski, Paul J.; Tsubota, Kevin; Waltjen, Kenneth E.; Watson, James A.; Wizinowich, Peter L.

    2000-07-01

    The wavefront controller for the Keck Observatory AO system consists of two separate real-time control loops: a tip-tilt control loop to remove tilt from the incoming wavefront, and a deformable mirror control loop to remove higher-order aberrations. In this paper, we describe these control loops and analyze their performance using diagnostic data acquired during the integration and testing of the AO system on the telescope. Disturbance rejection curves for the controllers are calculated from the experimental data and compared to theory. The residual wavefront errors due to control loop bandwidth are also calculated from the data, and possible improvements to the controller performance are discussed.

  9. A Prediction of the Damping Properties of Hindered Phenol AO-60/polyacrylate Rubber (AO-60/ACM) Composites through Molecular Dynamics Simulation

    NASA Astrophysics Data System (ADS)

    Yang, Da-Wei; Zhao, Xiu-Ying; Zhang, Geng; Li, Qiang-Guo; Wu, Si-Zhu

    2016-05-01

    Molecule dynamics (MD) simulation, a molecular-level method, was applied to predict the damping properties of AO-60/polyacrylate rubber (AO-60/ACM) composites before experimental measures were performed. MD simulation results revealed that two types of hydrogen bond, namely, type A (AO-60) -OH•••O=C- (ACM), type B (AO-60) - OH•••O=C- (AO-60) were formed. Then, the AO-60/ACM composites were fabricated and tested to verify the accuracy of the MD simulation through dynamic mechanical thermal analysis (DMTA). DMTA results showed that the introduction of AO-60 could remarkably improve the damping properties of the composites, including the increase of glass transition temperature (Tg) alongside with the loss factor (tan δ), also indicating the AO-60/ACM(98/100) had the best damping performance amongst the composites which verified by the experimental.

  10. Course Material Model in A&O Learning Environment.

    ERIC Educational Resources Information Center

    Levasma, Jarkko; Nykanen, Ossi

    One of the problematic issues in the content development for learning environments is the process of importing various types of course material into the environment. This paper describes a method for importing material into the A&O open learning environment by introducing a material model for metadata recognized by the environment. The first…

  11. Real-time control system verification for ELT AO systems

    NASA Astrophysics Data System (ADS)

    Basden, Alastair; Myers, Richard; Morris, Tim; Bharmal, Nazim; Bitenc, Urban; Dipper, Nigel; Reeves, Andrew; Gendron, Eric; Rousset, Gérard; Hubert, Zoltan; Vidal, Fabrice; Matin, Olivier; Gratadour, Damien; Chemla, Fanny

    2013-12-01

    ELT AO systems have demanding computational requirements for real-timecontrol. These systems are required to be fully tested and robustbefore commissioning so that valuable on-sky time is not wasted. Inthis talk I will report recent work at Durham on our ELT AO real-timecontrol system, algorithms that we use to improve robustness, anddevelopment of an end-to-end testing environment that will allow fulltesting of real-time control systems, including both Monte-Carlosimulation and hardware approaches. The talk will include experiencegained with CANARY, how the robustness of this system has beenimproved, and our experience operating with four laser guide stars. Workcarried out in this area on the DRAGON test-bench will also bedescribed.

  12. High-Resolution Imaging of Asteroids/Satellites with AO

    NASA Astrophysics Data System (ADS)

    Merline, William

    2012-02-01

    We propose to make high-resolution observations of asteroids using AO, to measure size, shape, and pole position (spin vectors), and/or to search for satellites. We have demonstrated that AO imaging allows determination of the pole/dimensions in 1 or 2 nights on a single target, rather than the years of observations with lightcurve inversion techniques that only yield poles and axial ratios, not true dimensions. Our new technique (KOALA) combines AO imaging with lightcurve and occultation data for optimum size/shape determinations. We request that LGS be available for faint targets, but using NGS AO, we will measure several large and intermediate asteroids that are favorably placed in spring/summer of 2012 for size/shape/pole. Accurately determining the volume from the often-irregular shape allows us to derive densities to much greater precision in cases where the mass is known, e.g., from the presence of a satellite. We will search several d! ozen asteroids for the presence of satellites, particularly in under-studied populations, particularly NEOs (we have recently achieved the first-ever optical image of an NEO binary [Merline et al. 2008b, IAUC 8977]). Satellites provide a real-life lab for testing collisional models. We will search for satellites around special objects at the request of lightcurve observers, and we will make a search for debris in the vicinity of Pluto, in support of the New Horizons mission. Our shape/size work requires observations over most of a full rotation period (typically several hours).

  13. LDEF results for polymer matrix composite experiment AO 180

    NASA Technical Reports Server (NTRS)

    Tennyson, R. C.

    1992-01-01

    This report represents a summary of the results obtained to-date on a polymer matrix composite experiment (AO 180) located at station D-12, about 82 deg off the 'ram' direction. Different material systems comprised of graphite, boron, and aramid (Kevlar) fiber reinforcements were studied. Although previous results were presented on in-situ thermal-vacuum cycling effects, particularly dimensional changes associated with outgassing, additional comparative data will be shown from ground-based tests on control and flight samples. The system employed was fully automated for thermal-vacuum cycling using a laser interferometer for monitoring displacements. Erosion of all three classes of materials due to atomic oxygen (AO) will also be discussed, including angle of incidence effects. Data from this experiment will be compared to published results for similar materials in other LDEF experiments. Composite materials' erosion yields will be presented on an AO design nomogram useful for estimating total material loss for given exposure conditions in low Earth orbit (LEO). Optical properties of these materials will also be compared with control samples. A survey of the damage caused by micrometeoroids/debris impacts will be addressed as they relate to polymer matrix composites. Correlations between hole size and damage pattern will be given. Reference to a new nomogram for estimating the number distribution of micrometeoroid/debris impacts for a given space structure as a function of time in LEO will be addressed based on LDEF data.

  14. Single-shot retinal imaging with AO spectral OCT

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Rha, Jungtae; Jonnal, Ravi S.; Miller, Donald T.

    2005-04-01

    We demonstrate for the first time an adaptive optics (AO) spectral OCT retina camera that acquires with unprecedented 3D resolution (2.9 μm lateral; 5.5 μm axial) single shot B-scans of the living human retina. The camera centers on a Michelson interferometer that consists of a superluminescent diode for line illuminating the subject's retinal; voice coil translator for controlling the optical path length of the reference channel; and an imaging spectrometer that is cascaded with a 12-bit area CCD array. The imaging spectrometer was designed with negligible off-axis aberrations and was constructed from stock optical components. AO was integrated into the detector channel of the interferometer and dynamically compensated for most of the ocular aberration across a 6 mm pupil. Short bursts of B-scans, with 100 Ascans each, were successfully acquired at 1 msec intervals. Camera sensitivity was found sufficient to detect reflections from all major retinal layers. Individual outer segments of photoreceptors at different retinal eccentricities were observed in vivo. Periodicity of the outer segments matched cone spacing as measured from AO flood illuminated images of the same patches of retina.

  15. AO Distal Radius Fracture Classification: Global Perspective on Observer Agreement.

    PubMed

    Jayakumar, Prakash; Teunis, Teun; Giménez, Beatriz Bravo; Verstreken, Frederik; Di Mascio, Livio; Jupiter, Jesse B

    2017-02-01

    Background The primary objective of this study was to test interobserver reliability when classifying fractures by consensus by AO types and groups among a large international group of surgeons. Secondarily, we assessed the difference in inter- and intraobserver agreement of the AO classification in relation to geographical location, level of training, and subspecialty. Methods A randomized set of radiographic and computed tomographic images from a consecutive series of 96 distal radius fractures (DRFs), treated between October 2010 and April 2013, was classified using an electronic web-based portal by an invited group of participants on two occasions. Results Interobserver reliability was substantial when classifying AO type A fractures but fair and moderate for type B and C fractures, respectively. No difference was observed by location, except for an apparent difference between participants from India and Australia classifying type B fractures. No statistically significant associations were observed comparing interobserver agreement by level of training and no differences were shown comparing subspecialties. Intra-rater reproducibility was "substantial" for fracture types and "fair" for fracture groups with no difference accounting for location, training level, or specialty. Conclusion Improved definition of reliability and reproducibility of this classification may be achieved using large international groups of raters, empowering decision making on which system to utilize. Level of Evidence Level III.

  16. SIMS chemical and isotopic analysis of impact features from LDEF experiments AO187-1 and AO187-2

    NASA Technical Reports Server (NTRS)

    Stadermann, Frank J.; Amari, Sachiko; Foote, John; Swan, Pat; Walker, Robert M.; Zinner, Ernst

    1995-01-01

    Previous secondary ion mass spectrometry (SIMS) studies of extended impact features from LDEF capture cell experiment AO187-2 showed that it is possible to distinguish natural and man-made particle impacts based on the chemical composition of projectile residues. The same measurement technique has now been applied to specially prepared gold target impacts from experiment AO187-1 in order to identify the origins of projectiles that left deposits too thin to be analyzed by conventional energy-dispersive x-ray (EDX) spectroscopy. The results indicate that SIMS may be the method of choice for the analysis of impact deposits on a variety of sample surfaces. SIMS was also used to determine the isotopic compositions of impact residues from several natural projectiles. Within the precision of the measurements all analyzed residues show isotopically normal compositions.

  17. Histoire du télescope, la contemplation de l'Univers, des premiers instruments aux actuelles machines célestes

    NASA Astrophysics Data System (ADS)

    Nazé, Yaël

    2009-01-01

    Alors que la plupart des scientifiques réalisent leurs expérimentations en laboratoire, les astronomes sont condamnés à ne jamais pouvoir toucher l'objet de leurs travaux: le ciel se laisse contempler mais demeure hors d'atteinte. Pour déchiffrer le message céleste, l'oeil ne suffit pas. Il fallut attendre la naissance de la première lunette astronomique pour ouvrir une nouvelle voie à notre insatiable désir de savoir. Ancêtre de tous les télescopes petits et grands, ce tout premier instrument d'observation allait en effet étendre vers l'infini le pouvoir de nos yeux. Quatre cents ans après, ce sont d'immenses machines qui scrutent pour nous l'Univers, en nous permettant même de remonter le temps. C'est leur histoire qui nous est racontée ici mais, par deçà les engins les plus complexes, ce livre nous parle de leurs bâtisseurs. Démontant au passage certaines idées reçues, ce livre nous plonge dans les balbutiements de ces instruments avant de nous emmener côtoyer les premiers géants et découvrir les révolutions en cours. Illustré de nombreux documents historiques et techniques, ce récit est également pourvu d'encadrés expliquant en profondeur le fonctionnement des instruments.

  18. Identification of system misregistrations during AO-corrected observations

    NASA Astrophysics Data System (ADS)

    Béchet, C.; Thiébaut, É.; .; Tallon, M.; Kolb, J.; Madec, P.-Y.

    2011-09-01

    The E-ELT will be equipped with a deformable mirror inside the telescope. The performance of reconstruction and control depends on the calibration of the interaction matrix- or a model of the interaction matrix- , which characterizes the system and the relationship between the commands sent to the deformable mirrors (DM) and the wavefront sensors (WFS) slopes. Such a calibration will be more complex than for the current systems at the VLT since it will have to be at least partly measured on sky and for a much larger number of degrees of freedom (more than 5000). In addition, gravity or temperature variations for instance are likely to introduce slow evolution of the matching between the M4 Deformable mirror and the WFS geometry. This can occur during observations and therefore degrade the adaptive optics (AO) correction. To relax the need of frequent painful calibrations and to prevent a loss of performance due to misregistrations, we investigate how to track the evolution of the interaction matrix errors in closed-loop without introducing any degradation in the observations. This is done thanks to identification methods and optimization theory. First, we formally describe the problem and the difficulties of such an identification in closed-loop configuration. Then, we present 2 solutions, based on the optimization of the error of estimates of the WFS slopes, at the output of the closed-loop AO. The performance of the methods and their limitations are discussed formally and thanks to numerical simulations of a high order AO system. We finally explore to which extent these methods currently studied for the Adaptive Optics Facility (AOF) at the VLT can be applied to the E-ELT.

  19. Green FLASH: energy efficient real-time control for AO

    NASA Astrophysics Data System (ADS)

    Gratadour, D.; Dipper, N.; Biasi, R.; Deneux, H.; Bernard, J.; Brule, J.; Dembet, R.; Doucet, N.; Ferreira, F.; Gendron, E.; Laine, M.; Perret, D.; Rousset, G.; Sevin, A.; Bitenc, U.; Geng, D.; Younger, E.; Andrighettoni, M.; Angerer, G.; Patauner, C.; Pescoller, D.; Porta, F.; Dufourcq, G.; Flaischer, A.; Leclere, J.-B.; Nai, A.; Palazzari, P.; Pretet, D.; Rouaud, C.

    2016-07-01

    The main goal of Green Flash is to design and build a prototype for a Real-Time Controller (RTC) targeting the European Extremely Large Telescope (E-ELT) Adaptive Optics (AO) instrumentation. The E-ELT is a 39m diameter telescope to see first light in the early 2020s. To build this critical component of the telescope operations, the astronomical community is facing technical challenges, emerging from the combination of high data transfer bandwidth, low latency and high throughput requirements, similar to the identified critical barriers on the road to Exascale. With Green Flash, we will propose technical solutions, assess these enabling technologies through prototyping and assemble a full scale demonstrator to be validated with a simulator and tested on sky. With this R&D program we aim at feeding the E-ELT AO systems preliminary design studies, led by the selected first-light instruments consortia, with technological validations supporting the designs of their RTC modules. Our strategy is based on a strong interaction between academic and industrial partners. Components specifications and system requirements are derived from the AO application. Industrial partners lead the development of enabling technologies aiming at innovative tailored solutions with potential wide application range. The academic partners provide the missing links in the ecosystem, targeting their application with mainstream solutions. This increases both the value and market opportunities of the developed products. A prototype harboring all the features is used to assess the performance. It also provides the proof of concept for a resilient modular solution to equip a large scale European scientific facility, while containing the development cost by providing opportunities for return on investment.

  20. 76 FR 4726 - Avaya Global Services, AOS Service Delivery, Worldwide Services Group, Including Workers Whose...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-26

    ... insurance (UI) tax account under the name Nortel Networks, Inc. and Avaya Global Services, AOS Service... unemployment (UI) wages are reported through Nortel Networks, Inc. and Avaya Global Services, AOS Service... Nortel Networks, Inc., Billerica, Massachusetts (TA-W-74,411B); Avaya Global Services, AOS...

  1. Measuring Geosynchronous Satellites from Stellar Appulses with AO

    DTIC Science & Technology

    2014-09-01

    geosynchronous satellites using adaptive optics on our 3.5 m telescope with a Laser Guide Star (LGS) and without a laser (Natural Guide Star, NGS), we found two...adaptive optics on our 3.5 m telescope with a Laser Guide Star (LGS) and without a laser (Natural Guide Star, NGS), we found two satellites in the... telescope using NGS AO, we targeted a geo, satellite 28868 ANIK F1-R, for study. We imaged it intermittently for 23 minutes, noticing 7 passing stars in

  2. Intramedullary locking femoral nails. Experience with the AO nail.

    PubMed Central

    Fogarty, A. B.; Yeates, H. A.

    1991-01-01

    The AO interlocking nail was introduced to the Ulster Hospital, Dundonald in 1988 and since then has been used in over 50 patients with femoral shaft fractures. We have reviewed 45 patients with 46 femoral shaft fractures treated between June 1988 and April 1990. These included four compound fractures and 13 comminuted fractures. The results compare favourably with other series. The union rate was 98% and there were no instances of deep infection. The alternative treatment methods available are discussed along with a review of the relevant literature. Images Fig 3 Fig 5 PMID:1785145

  3. LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray C03

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray C03 The IDE mounting plate and the detector frames are coated with a brown stain similiar to that seen on the other experiments in this and other trays located nearby. The stain seems to be slightly darker along the lower edge of the solar sensor mounting plate. The colors and designs seen on the detectors are reflections of the surrounding area. The thin brown film on the detectors metallic surface has resulted in a duller reflection of a technician, in the upper left, and other items.

  4. Titanium alloys (AoN) and their involvement in osseointegration

    PubMed Central

    Danza, Matteo; Zollino, Ilaria; Candotto, Valentina; Cura, Francesca; Carinci, Francesco

    2012-01-01

    Background: Osseointegration is essential for a long-term successful and inflammation-free dental implant. Such a result depends on osteoblastic cells growth and differentiation at the tissue-implant interface. The aim of this study was to compare two different AoN titanium layers (GR4 and GR5) to investigate which one had a greater osteoconductive power using human osteoblasts (HOb) culture at two different time-points. Materials and Methods: The expression levels of some bone-related (ALPL, COL1A1, COL3A1, SPP1, RUNX2, and SPARC) were analyzed using real time reverse transcription-polymerase chain reaction (real time RT-PCR). Results: Real-time RT-PCR data showed that after 3 days of treatment with TiA4GR, the genes up-regulated were COL3A1, ALPL, SPP1, and RUNX2. Moreover, no difference in gene expression was noticed 4 days later. On the other hand, the genes that overexpressed after 3 days of treatment with AoN5GR were ALPL, SPP1, and RUNX2. In both cases, the expression of COL1A1 and SPARC was negatively regulated. Conclusion: Our data showed that both titanium surfaces led to osteoblasts recruitment, maturation, and differentiation, thus promoting osseointegration at the tissue-implant interface. PMID:23814585

  5. Illuminating Free-floating Planet Demographics with Keck AO

    NASA Astrophysics Data System (ADS)

    Henderson, Calen B.

    2017-01-01

    The frequency and mass function of free-floating planets (FFPs) are unknown. Gravitational microlensing is able to explore the demographics of FFPs, which are identifiable as short-timescale microlensing events, lasting of-order 1 day for Jupiter-mass planets. In 2011, the MOA ground-based microlensing survey group announced the discovery of an excess of short-timescale microlensing events over what was expected from Galactic models that incorporate stellar densities and kinematics. They account for this excess by positing a population of Jupiter-mass FFPs that outnumbers stars by a ratio of nearly 2:1. However, there are several other possible astrophysical explanations for short-timescale microlensing events, including bound planets on wide orbits and high-velocity stars. Although the specific events identified by MOA lack mass measurements, high-resolution imaging can determine whether the lens systems are luminous, which would exclude the FFP conclusion through proof by contradiction. We have taken H-band adaptive optics (AO) observations of the MOA FFP candidates using NIRC2 on Keck II in order to test this result. Here I will present preliminary results from these AO observations, which will help inform our understanding of the demographics of FFPs.

  6. Robo-AO: autonomous and replicable laser-adaptive-optics and science system

    NASA Astrophysics Data System (ADS)

    Baranec, C.; Riddle, R.; Ramaprakash, A. N.; Law, N.; Tendulkar, S.; Kulkarni, S.; Dekany, R.; Bui, K.; Davis, J.; Burse, M.; Das, H.; Hildebrandt, S.; Punnadi, S.; Smith, R.

    2012-07-01

    We have created a new autonomous laser-guide-star adaptive-optics (AO) instrument on the 60-inch (1.5-m) telescope at Palomar Observatory called Robo-AO. The instrument enables diffraction-limited resolution observing in the visible and near-infrared with the ability to observe well over one-hundred targets per night due to its fully robotic operation. Robo-AO is being used for AO surveys of targets numbering in the thousands, rapid AO imaging of transient events and long-term AO monitoring not feasible on large diameter telescope systems. We have taken advantage of cost-effective advances in deformable mirror and laser technology while engineering Robo-AO with the intention of cloning the system for other few-meter class telescopes around the world.

  7. LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray H11

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray H11 The Interplanetary Dust Experiment hardware has a thin brown stain on the exposed surfaces. A deeper brown stain, probably from the material underneath the small electrical cover plate of the detector frame, can be seen in the upper right corner of some of the detectors. Stain that was seen on the solar sensor base plate in the flight photograph cannot be seen because of reflected light. The colors seen in the detector's mirror like surface are reflections of the surrounding area. A dark spot seen on a detector in the third row from the top in the flight photograph, was not found in a postflight inspection. A close inspection of this photograph does reveal several impact damage locations.

  8. Experience And Results With Preoperatively Shaped AO Mandibular Reconstruction Plates

    NASA Astrophysics Data System (ADS)

    Reuters, Ulrich; Prein, Joachim; Muller, Werner

    1989-04-01

    As a rule continuous bony defects of the mandible after tumour resection are temporarily bridged with the AO reconstruction plate. To precontour the plate, CT-scans of the mandible at a scale of 1:1 6 mm above and parallel to the inferior margin are needed. Corresponding layers further cranial show the anatomy of the chin. Using a lateral cephalograph, the mandibular angle and the length of the plate in the ascending ramus are measured. Of the 19 preshaped reconstruction plates implanted, 11 did not need any intraoperative adjustment of shape. The other 8 plates needed only slight modifications of contour. Preoperative bending of the reconstruction plate reduces the time taken for the operation, protects the material and the plate is precisely shaped.

  9. The 1987 outburst of the BL Lacertid AO 0235 + 164

    NASA Astrophysics Data System (ADS)

    Webb, J. R.; Smith, A. G.

    1989-08-01

    The violently variable BL Lacertid AO 0235 + 164 displayed a 3.24 magnitude outburst in early 1987. This outburst was observed intensively from Rosemary Hill Observatory in three colors. Long term monitoring observations made at Rosemary Hill are examined in an effort to find any recurring timescales associated with this outburst and previous large amplitude outbursts. The energetics of the 1987 outburst are analyzed in terms of the Shields and Wheeler model of a magnetized accretion disk. The timescales identified in the power spectrum (2.8 and 1.6 yr) are input into the model as the storage timescales. Since the emitted energy calculated from the optical burst cannot be stored in a magnetized disk at an allowable radius, it is concluded that either the storage timescales are longer than those identified in the power spectrum, or relativistic beaming effects must be considered, with a Doppler factor of 1.3 to 1.6.

  10. LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray C09

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray C09 The postflight photograph was taken prior to the experiment tray being removed from the LDEF. The tray corner clamp blocks are un-anodized aluminum and that alone accounts for the major difference in color between the corner clamp blocks and the center clamp blocks. The IDE mounting plate and the detector frames and detectors seem to be in excellent condition. Close inspection of the photograph reveals several locations where impacts on detector surfaces are visible. A faint gold or tan stain can be seen around several of the fasteners and in a rectangular configuration, near the center, along the bottom edge of the detector mounting plate. Stains can also be seen near the top right edge of the solar sensor, on the mounting plate, and around the extreme edges of the solar sensor baseplate. The colors and designs seen on the detectors are reflections of the surrounding area.

  11. The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF)

    PubMed Central

    Joeris, Alexander; Lutz, Nicolas; Blumenthal, Andrea; Slongo, Theddy; Audigé, Laurent

    2017-01-01

    Background and purpose To achieve a common understanding when dealing with long bone fractures in children, the AO Pediatric Comprehensive Classification of Long Bone Fractures (AO PCCF) was introduced in 2007. As part of its final validation, we present the most relevant fracture patterns in the upper extremities of a representative population of children classified according to the PCCF. Patients and methods We included children and adolescents (0–17 years old) diagnosed with 1 or more long bone fractures between January 2009 and December 2011 at the university hospitals in Bern and Lausanne (Switzerland). Patient charts were retrospectively reviewed and fractures were classified from standard radiographs. Results Of 2,292 upper extremity fractures in 2,203 children and adolescents, 26% involved the humerus and 74% involved the forearm. In the humerus, 61%, and in the forearm, 80% of single distal fractures involved the metaphysis. In adolescents, single humerus fractures were more often epiphyseal and diaphyseal fractures, and among adolescents radius fractures were more often epiphyseal fractures than in other age groups. 47% of combined forearm fractures were distal metaphyseal fractures. Only 0.7% of fractures could not be classified within 1 of the child-specific fracture patterns. Of the single epiphyseal fractures, 49% were Salter-Harris type-II (SH II) fractures; of these, 94% occurred in schoolchildren and adolescents. Of the metaphyseal fractures, 58% showed an incomplete fracture pattern. 89% of incomplete fractures affected the distal radius. Of the diaphyseal fractures, 32% were greenstick fractures. 24 Monteggia fractures occurred in pre-school children and schoolchildren, and 2 occurred in adolescents. Interpretation The pattern of pediatric fractures in the upper extremity can be comprehensively described according to the PCCF. Prospective clinical studies are needed to determine its clinical relevance for treatment decisions and prognostication

  12. The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF)

    PubMed Central

    Joeris, Alexander; Lutz, Nicolas; Blumenthal, Andrea; Slongo, Theddy; Audigé, Laurent

    2017-01-01

    Background and purpose To achieve a common understanding when dealing with long bone fractures in children, the AO Pediatric Comprehensive Classification of Long Bone Fractures (AO PCCF) was introduced in 2007. As part of its final validation, we present the most relevant fracture patterns in the lower extremities of a representative population of children classified according to the PCCF. Patients and methods We included patients up to the age of 17 who were diagnosed with 1 or more long bone fractures between January 2009 and December 2011 at either of 2 tertiary care university hospitals in Switzerland. Patient charts were retrospectively reviewed. Results More lower extremity fractures occurred in boys (62%, n = 341). Of 548 fractured long bones in the lower extremity, 25% involved the femur and 75% the lower leg. The older the patients, the more combined fractures of the tibia and fibula were sustained (adolescents: 50%, 61 of 123). Salter-Harris (SH) fracture patterns represented 66% of single epiphyseal fractures (83 of 126). Overall, 74 of the 83 SH patterns occurred in the distal epiphysis. Of all the metaphyseal fractures, 74 of 79 were classified as incomplete or complete. Complete oblique spiral fractures accounted for 57% of diaphyseal fractures (120 of 211). Of all fractures, 7% (40 of 548) were classified in the category "other", including 29 fractures that were identified as toddler’s fractures. 5 combined lower leg fractures were reported in the proximal metaphysis, 40 in the diaphysis, 26 in the distal metaphysis, and 8 in the distal epiphysis. Interpretation The PCCF allows classification of lower extremity fracture patterns in the clinical setting. Re-introduction of a specific code for toddler’s fractures in the PCCF should be considered. PMID:27882811

  13. The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF)

    PubMed Central

    Audigé, Laurent; Slongo, Theddy; Lutz, Nicolas; Blumenthal, Andrea; Joeris, Alexander

    2017-01-01

    Background and purpose The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF) describes the localization and morphology of fractures, and considers severity in 2 categories: (1) simple, and (2) multifragmentary. We evaluated simple and multifragmentary fractures in a large consecutive cohort of children diagnosed with long bone fractures in Switzerland. Patients and methods Children and adolescents treated for fractures between 2009 and 2011 at 2 tertiary pediatric surgery hospitals were retrospectively included. Fractures were classified according to the AO PCCF. Severity classes were described according to fracture location, patient age and sex, BMI, and cause of trauma. Results Of all trauma events, 3% (84 of 2,730) were diagnosed with a multifragmentary fracture. This proportion was age-related: 2% of multifragmentary fractures occurred in school­children and 7% occurred in adolescents. In patients diagnosed with a single fracture only, the highest percentage of multifragmentation occurred in the femur (12%, 15 of 123). In fractured paired radius/ulna bones, multifragmentation occurred in 2% (11 of 687); in fractured paired tibia/fibula bones, it occurred in 21% (24 of 115), particularly in schoolchildren (5 of 18) and adolescents (16 of 40). In a multivariable regression model, age, cause of injury, and bone were found to be relevant prognostic factors of multifragmentation (odds ratio (OR) > 2). Interpretation Overall, multifragmentation in long bone fractures in children was rare and was mostly observed in adolescents. The femur was mostly affected in single fractures and the lower leg was mostly affected in paired-bone fractures. The clinical relevance of multifragmentation regarding growth and long-term functional recovery remains to be determined. PMID:27882814

  14. HST and Keck AO Images of Vortices on Jupiter

    NASA Astrophysics Data System (ADS)

    de Pater, Imke; Wong, M.; Luszcz-Cook, S.; Adamkovics, M.; Marcus, P.; Asay-Davis, X.; Conrad, A.; Go, C.

    2009-09-01

    Observations of Jupiter were conducted in April 2006 and May 2008 with both HST (250-890 nm) and the 10-m Keck telescope. On Keck we used the near-infrared camera NIRC2, coupled to the AO system, at 1.2 to 5 micrometers. At 5 um we are sensitive to Jupiter's thermal emission in cloud-free regions of the atmosphere, while at 1.2 um we see reflected sunlight from hazes and clouds in the troposphere-stratosphere. All small ovals (i.e., all except for Oval BA and the GRS) appear to be surrounded by bright rings at 5 mu, with typical brightness temperatures of 225-250 K, and hence probing depths to 2.5-4 bar. We argue that the small vortices are columnar structures, extending down into the water cloud. Air is rising along the center of these vortices, and descending around the outer periphery; the storm systems are likely fueled by the latent heat released from the water cloud. The descending part of the vertical circulation in the larger ovals is within the ovals, likely at the location of the red ring in Oval BA, which may indicate the maximum radial distance where such return flows can take place. On 19 July 2009, amateur observer Anthony Wesley (Australia) reported a dark spot/streak on Jupiter, near a southern latitude of 56 deg, which he attributed to an impact (analogous to the SL9 impact on Jupiter). We are scheduled to observe Jupiter with the Keck AO system on 24 July 2009 UT; if observations are successful, we will report preliminary results.

  15. The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF).

    PubMed

    Joeris, Alexander; Lutz, Nicolas; Blumenthal, Andrea; Slongo, Theddy; Audigé, Laurent

    2017-04-01

    Background and purpose - To achieve a common understanding when dealing with long bone fractures in children, the AO Pediatric Comprehensive Classification of Long Bone Fractures (AO PCCF) was introduced in 2007. As part of its final validation, we present the most relevant fracture patterns in the upper extremities of a representative population of children classified according to the PCCF. Patients and methods - We included children and adolescents (0-17 years old) diagnosed with 1 or more long bone fractures between January 2009 and December 2011 at the university hospitals in Bern and Lausanne (Switzerland). Patient charts were retrospectively reviewed and fractures were classified from standard radiographs. Results - Of 2,292 upper extremity fractures in 2,203 children and adolescents, 26% involved the humerus and 74% involved the forearm. In the humerus, 61%, and in the forearm, 80% of single distal fractures involved the metaphysis. In adolescents, single humerus fractures were more often epiphyseal and diaphyseal fractures, and among adolescents radius fractures were more often epiphyseal fractures than in other age groups. 47% of combined forearm fractures were distal metaphyseal fractures. Only 0.7% of fractures could not be classified within 1 of the child-specific fracture patterns. Of the single epiphyseal fractures, 49% were Salter-Harris type-II (SH II) fractures; of these, 94% occurred in schoolchildren and adolescents. Of the metaphyseal fractures, 58% showed an incomplete fracture pattern. 89% of incomplete fractures affected the distal radius. Of the diaphyseal fractures, 32% were greenstick fractures. 24 Monteggia fractures occurred in pre-school children and schoolchildren, and 2 occurred in adolescents. Interpretation - The pattern of pediatric fractures in the upper extremity can be comprehensively described according to the PCCF. Prospective clinical studies are needed to determine its clinical relevance for treatment decisions and

  16. The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF).

    PubMed

    Audigé, Laurent; Slongo, Theddy; Lutz, Nicolas; Blumenthal, Andrea; Joeris, Alexander

    2017-04-01

    Background and purpose - The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF) describes the localization and morphology of fractures, and considers severity in 2 categories: (1) simple, and (2) multifragmentary. We evaluated simple and multifragmentary fractures in a large consecutive cohort of children diagnosed with long bone fractures in Switzerland. Patients and methods - Children and adolescents treated for fractures between 2009 and 2011 at 2 tertiary pediatric surgery hospitals were retrospectively included. Fractures were classified according to the AO PCCF. Severity classes were described according to fracture location, patient age and sex, BMI, and cause of trauma. Results - Of all trauma events, 3% (84 of 2,730) were diagnosed with a multifragmentary fracture. This proportion was age-related: 2% of multifragmentary fractures occurred in school-children and 7% occurred in adolescents. In patients diagnosed with a single fracture only, the highest percentage of multifragmentation occurred in the femur (12%, 15 of 123). In fractured paired radius/ulna bones, multifragmentation occurred in 2% (11 of 687); in fractured paired tibia/fibula bones, it occurred in 21% (24 of 115), particularly in schoolchildren (5 of 18) and adolescents (16 of 40). In a multivariable regression model, age, cause of injury, and bone were found to be relevant prognostic factors of multifragmentation (odds ratio (OR) > 2). Interpretation - Overall, multifragmentation in long bone fractures in children was rare and was mostly observed in adolescents. The femur was mostly affected in single fractures and the lower leg was mostly affected in paired-bone fractures. The clinical relevance of multifragmentation regarding growth and long-term functional recovery remains to be determined.

  17. The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF).

    PubMed

    Joeris, Alexander; Lutz, Nicolas; Blumenthal, Andrea; Slongo, Theddy; Audigé, Laurent

    2017-04-01

    Background and purpose - To achieve a common understanding when dealing with long bone fractures in children, the AO Pediatric Comprehensive Classification of Long Bone Fractures (AO PCCF) was introduced in 2007. As part of its final validation, we present the most relevant fracture patterns in the lower extremities of a representative population of children classified according to the PCCF. Patients and methods - We included patients up to the age of 17 who were diagnosed with 1 or more long bone fractures between January 2009 and December 2011 at either of 2 tertiary care university hospitals in Switzerland. Patient charts were retrospectively reviewed. Results - More lower extremity fractures occurred in boys (62%, n = 341). Of 548 fractured long bones in the lower extremity, 25% involved the femur and 75% the lower leg. The older the patients, the more combined fractures of the tibia and fibula were sustained (adolescents: 50%, 61 of 123). Salter-Harris (SH) fracture patterns represented 66% of single epiphyseal fractures (83 of 126). Overall, 74 of the 83 SH patterns occurred in the distal epiphysis. Of all the metaphyseal fractures, 74 of 79 were classified as incomplete or complete. Complete oblique spiral fractures accounted for 57% of diaphyseal fractures (120 of 211). Of all fractures, 7% (40 of 548) were classified in the category "other", including 29 fractures that were identified as toddler's fractures. 5 combined lower leg fractures were reported in the proximal metaphysis, 40 in the diaphysis, 26 in the distal metaphysis, and 8 in the distal epiphysis. Interpretation - The PCCF allows classification of lower extremity fracture patterns in the clinical setting. Re-introduction of a specific code for toddler's fractures in the PCCF should be considered.

  18. Robo-AO KP: A new era in robotic adaptive optics

    NASA Astrophysics Data System (ADS)

    Riddle, Reed L.; Baranec, Christoph; Law, Nicholas M.; Kulkarni, Shrinivas R.; Duev, Dmitry; Ziegler, Carl; Jensen-Clem, Rebecca M.; Atkinson, Dani Eleanor; Tanner, Angelle M.; Zhang, Celia; Ray, Amy

    2016-01-01

    Robo-AO is the first and only fully automated adaptive optics laser guide star AO instrument. It was developed as an instrument for 1-3m robotic telescopes, in order to take advantage of their availability to pursue large survey programs and target of opportunity observations that aren't possible with other AO systems. Robo-AO is currently the most efficient AO system in existence, and it can achieve an observation rate of 20+ science targets per hour. In more than three years of operations at Palomar Observatory, it has been quite successful, producing technology that is being adapted by other AO systems and robotic telescope projects, as well as several high impact scientific publications. Now, Robo-AO has been selected to take over operation of the Kitt Peak National Observatory 2.1m telescope. This will give Robo-AO KP the opportunity to pursue multiple science programs consisting of several thousand targets each during the three years it will be on the telescope. One-sixth of the observing time will be allocated to the US community through the NOAO TAC process. This presentation will discuss the process adapting Robo-AO to the KPNO 2.1m telescope, the plans for integration and initial operations, and the science operations and programs to be pursued.

  19. LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray G10

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray G10 The IDE experiment appears to be in excellent condition in the postflight photograph. All bond joints seem to have survived the space environment and the experiment hardware seems to be intact. The direction and intensity of the artificial light source has caused hot spots and reflections that tend to wash out the brown stain on the exposed surfaces. A close inspection of individual detectors reveal locations where impacts have occurred and damage is present. In the detector layout in the lower left corner of the tray, two detectors continue to show the discolorations observed in the flight photograph. A triangular shape can be seen in the detector located in the second horizontal row from the bottom and the second vertical row from the left. The other detector, located in the third horizontal row from the bottom and the fourth vertical row from the left has an irregular shaped, very faint, discolora tion. The blue color in the detectors metallic surface is caused by reflections of the surrounding area.

  20. Atomic oxygen effects on LDEF experiment AO171

    NASA Technical Reports Server (NTRS)

    Whitaker, Ann F.; Kamenetzky, Rachel R.; Finckenor, Miria M.; Norwood, Joseph K.

    1993-01-01

    The Solar Array Materials Passive Long Duration Exposure Facility (LDEF) Experiment (SAMPLE), AO171, contained in total approximately 100 materials and materials processes with a 300 specimen complement. With the exception of experiment solar cell and solar cell modules, all test specimens were weighed before flight, thus allowing an accurate determination of mass loss as a result of space exposure. Since almost all of the test specimens were thermal vacuum baked before flight, the mass loss sustained can be attributed principally to atomic oxygen attack. The atomic oxygen effects observed and measured in five classes of materials is documented. The atomic oxygen reactivity values generated for these materials are compared to those values derived for the same materials from exposures on short term shuttle flights. An assessment of the utility of predicting long term atomic oxygen effects from short term exposures is given. This experiment was located on Row 8 position A which allowed all experiment materials to be exposed to an atomic oxygen fluence of 6.93 x 10(exp 21) atoms/cm(sup 2) as a result of being positioned 38 degrees off the RAM direction.

  1. LDEF (Flight), AO201 : Interplanetary Dust Experiment, Tray G10

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO201 : Interplanetary Dust Experiment, Tray G10 The flight/on-orbit photograph of the G10 experi ment tray was taken from the Orbiter aft flight deck during the LDEF retrieval. A light brown stain can be seen on the experiment tray flanges and to a lesser degree on the IDE Chemglaze Z tained their integrity. A light tan stain on the solar sensor base plate, located in the center of the tray, is more easily seen than that on the IDE mounting plate. Surface defects are highly visible due to the lighting conditions existing at the time the photograph was taken. The lighting angle is such that many impact craters can be seen. Two (2) detectors, located in the twenty (20) detector layout in the lower left corner of the tray, seem to have defects. A triangular shaped discoloration appears on the second detector from the left and in the second row from the bottom. Another irregular shaped discoloration can be seen on the fourth detector from the left and in the third row from the bottom. These discolorations appear to be due to material and/or fabrication defects and not reflected light. The blue colors on the detector's mirror like surface are caused by reflections of the LDEF surroundings.

  2. LDEF (Flight), AO038 : Interstellar Gas Experiment, Tray H09

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO038 : Interstellar Gas Experiment, Tray H09 The flight photograph of the Interstellar Gas Experiment was taken from the Orbiter aft flight deck during the LDEF retrieval. A very light contamination stain is present on the experiment tray flanges and on the most of the visible LDEF structure. The exception being a darker stain on the structure adjacent to thermal covers that provide venting for the LDEF interior. Both paint dots appear to be heavily coated with the brown contamination stain. The color of the white thermal control paint on the IGE has changed and now varies from off-white to a dark brown. The darker brown areas on the experiment baseplate, around the grid voltage cable connectors, appear to have come from contaminants flowing from inside the LDEF. A dark stain area can be seen on the lower half of the tray's right sidewall but a shadow hides most of the dark stain in the upper left corner of the tray. A lighter stain coats portions of the experiment baseplate and the outside of the canister housing. A beryllium copper collector foil is clearly visible in the lower left canister housing as are the baffles and reflected light from the fine wire mesh grid near the top of the canister housing. Due to an experi- ment system malfunction, the canister collector foils that are visible were exposed for the total mission.

  3. SCExAO as a precursor to an ELT exoplanet direct imaging instrument

    NASA Astrophysics Data System (ADS)

    Jovanovic, Nemanja; Guyon, Olivier; Martinache, Frantz; Clergeon, Christophe; Singh, Garima; Vievard, Sebastien; Kudo, Tomoyuki; Garrel, Vincent; Norris, Barnaby; Tuthill, Peter; Stewart, Paul; Huby, Elsa; Perrin, Guy; Lacour, Sylvestre

    2013-12-01

    The Subaru Coronagraphic Extreme AO (SCExAO) instrument consists of a high performance Phase Induced Amplitude Apodisation (PIAA) coronagraph combined with an extreme Adaptive Optics (AO) system operating in the near-infrared (H band). The extreme AO system driven by the 2000 element deformable mirror will allow for Strehl ratios>90% to be achieved in the H-band when it goes closed loop. This makes the SCExAO instrument a powerful platform for high contrast imaging down to angular separations of the order of 1 lambda/D and an ideal testbed for exploring coronagraphic techniques for ELTs. In this paper we report on the recent progress in regards to the development of the instrument, which includes the addition of a visible bench that makes use of the light at shorter wavelengths not currently utilized by SCExAO and closing the loop on the tip/tilt wavefront sensor. We will also discuss several exciting guest instruments which will expand the capabilities of SCExAO over the next few years; namely CHARIS which is a integral field spectrograph as well as VAMPIRES, a visible aperture masking experiment based on polarimetric analysis of circumstellar disks. In addition we will elucidate the unique role extreme AO systems will play in enabling high precision radial velocity spectroscopy for the detection of small companions.

  4. Patterns of Impairments in AOS and Mechanisms of Interaction between Phonological and Phonetic Encoding

    ERIC Educational Resources Information Center

    Laganaro, Marina

    2012-01-01

    Purpose: One reason why the diagnosis of apraxia of speech (AOS) and its underlying impairment are often debated may lie in the fact that most patients do not display pure patterns of AOS. Mixed patterns are clearly acknowledged at other levels of impairment (e.g., lexical-semantic and lexical-phonological), and they have contributed to debate…

  5. LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray B12

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray B12 The postflight photograph shows little change of the exposed surfaces when compared with the prelaunch photograph. Although not noticable in the photograph, a light coating of contamination was seen on all experiment surfaces in this location. The difference in colors of the IDE detectors, located on the right hand mounting plate, is a result of the reflected surroundings and not related to space exposure. A close observation of the detector surfaces reveal that some damage has occured from meteroid and/or debris impacts. One impact crater can be seen, upper right quadrant, on the detector located in the sixth (6th) row down from the top and the fifth (5th) row from the right. Other impacts, smaller in size, show as small white dots on the detector surface. The solar sensor seems to have changed little, if any. However, the color of the solar array baseplate, showing indications of contamination, appears to be darker than the detector mounting plate. The center section cover plate shows little change when compared with the pre-launch photograph. However, during inspection, a light coat of the brown contamination has been observed on all surfaces. The color of the bonding material (RTV) used to secure several thin specimen, sapphire, to individual mounting plates has changed from pink to gold. At one location, that of a single specimen, the bonding material is more gray than gold in color. This has been attributed to the specimen being considerably thicker. The EPDS thermal cover in the right hand side of the tray shows a light coating of brown contamination on the Chemglaze II A-276 white paint.

  6. LDEF (Postflight), AO038 : Interstellar Gas Experiment, Tray H06

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO038 : Interstellar Gas Experiment, Tray H06 The post landing photograph was taken from the Orbiter's cargo bay access hatch during post landing operations to prepare the Orbiter for the ferry flight from the Dryden Flight Research Center to the Kennedy Space Center. A very light contamination stain is present on the experiment tray flanges and on the most of the visible LDEF structure. The exception being a much darker stain on the structure adjacent to thermal covers that provide venting for the LDEF interior. The paint dot adjacent to the thermal cover vent area is heavily coated with the brown contamination stain while the paint dot adjacent to the center end cover plate has a very light coating. The color of the white thermal control paint on the IGE has changed and now varies from offwhite to a dark brown. The darker brown areas on the experiment baseplate, around the grid voltage cable connectors, appear to have come from contaminants flowing from inside the LDEF. A dark stain area can be seen on the tray's lower sidewall and in the upper left corner of the tray. A lighter stain coats portions of the experiment baseplate and the outside of the canister housing. A beryllium copper collector foil is clearly visible within the canister housings as are the baffles and reflected light from the fine wire mesh grid near the top of the canister housing. Due to an experi- ment system malfunction, the canister collector foils that are visible were exposed for the total mission.

  7. Multi-conjugate AO for the European Solar Telescope

    NASA Astrophysics Data System (ADS)

    Montilla, I.; Béchet, C.; Le Louarn, M.; Tallon, M.; Sánchez-Capuchino, J.; Collados Vera, M.

    2012-07-01

    The European Solar Telescope (EST) will be a 4-meter diameter world-class facility, optimized for studies of the magnetic coupling between the deep photosphere and upper chromosphere. It will specialize in high spatial resolution observations and therefore it has been designed to incorporate an innovative built-in Multi-Conjugate Adaptive Optics system (MCAO). It combines a narrow field high order sensor that will provide the information to correct the ground layer and a wide field low order sensor for the high altitude mirrors used in the MCAO mode. One of the challenging particularities of solar AO is that it has to be able to correct the turbulence for a wide range of observing elevations, from zenith to almost horizon. Also, seeing is usually worse at day-time, and most science is done at visible wavelengths. Therefore, the system has to include a large number of high altitude deformable mirrors. In the case of the EST, an arrangement of 4 high altitude DMs is used. Controlling such a number of mirrors makes it necessary to use fast reconstruction algorithms to deal with such large amount of degrees of freedom. For this reason, we have studied the performance of the Fractal Iterative Method (FriM) and the Fourier Transform Reconstructor (FTR), to the EST MCAO case. Using OCTOPUS, the end-to-end simulator of the European Southern Observatory, we have performed several simulations with both algorithms, being able to reach the science requirement of a homogeneous Strehl higher that 50% all over the 1 arcmin field of view.

  8. Lick Observatory's Shane telescope adaptive optics system (ShaneAO): research directions and progress

    NASA Astrophysics Data System (ADS)

    Gavel, Donald T.; Kupke, Renate; Rudy, Alexander R.; Srinath, Srikar; Dillon, Daren; Poyneer, Lisa A.

    2016-07-01

    We present a review of the ongoing research activity surrounding the adaptive optics system at the Shane telescope (ShaneAO) particularly the R&D efforts on the technology and algorithms for that will advance AO into wider application for astronomy. We are pursuing the AO challenges for whole sky coverage diffraction-limited correction down to visible science wavelengths. This demands high-order wavefront correction and bright artificial laser beacons. We present recent advancements in the development of MEMS based AO correction, woofer-tweeter architecture, wind-predictive wavefront control algorithms, atmospheric characterization, and a pulsed fiber amplifier guide star laser tuned for optical pumping of the sodium layer. We present the latest on-sky results from the new AO system and present status and experimental plans for the optical pumping guide star laser.

  9. Robo-AO: Initial results from the first autonomous laser guide star adaptive optics instrument

    NASA Astrophysics Data System (ADS)

    Riddle, R. L.; Baranec, C.; Law, N. M.; Ramaprakash, A. N.; Tendulkar, S.; Hogstrom, K.; Bui, K.; Burse, M.; Chordia, P.; Das, H.; Dekany, R.; Kulkarni, S.; Punnadi, S.; Smith, R.

    2014-12-01

    Large surveys are discovering thousands of objects which require further characterization at high angular resolution. The demands on space-based observatories and large telescopes with AO systems leave them generally unavailable for large high angular resolution surveys. To address this gap, we have developed Robo-AO, the first robotic laser AO system, as an economical and efficient imaging instrument for 1-3 m class telescopes. Observations of over 200 stellar objects per night have routinely been performed, with target-to-target observation overheads of less than 1.5 minutes. Scientific programs of several thousands of targets can be executed in mere weeks, and Robo-AO has already completed the three largest AO surveys to date.

  10. Bringing the Visible Universe into Focus with Robo-AO

    PubMed Central

    Baranec, Christoph; Riddle, Reed; Law, Nicholas M.; Ramaprakash, A.N.; Tendulkar, Shriharsh P.; Bui, Khanh; Burse, Mahesh P.; Chordia, Pravin; Das, Hillol K.; Davis, Jack T.C.; Dekany, Richard G.; Kasliwal, Mansi M.; Kulkarni, Shrinivas R.; Morton, Timothy D.; Ofek, Eran O.; Punnadi, Sujit

    2013-01-01

    focus a high-power laser beam in the direction of the astronomical target to create an artificial reference of known shape, also known as a 'laser guide star'. The Robo-AO laser adaptive optics system2,3 employs a 10-W ultraviolet laser focused at a distance of 10 km to generate a laser guide star. Wavefront sensor measurements of the laser guide star drive the adaptive optics correction resulting in diffraction-limited images that have an angular resolution of ~0.1 arc seconds on a 1.5-m telescope. PMID:23426078

  11. Bringing the visible universe into focus with Robo-AO.

    PubMed

    Baranec, Christoph; Riddle, Reed; Law, Nicholas M; Ramaprakash, A N; Tendulkar, Shriharsh P; Bui, Khanh; Burse, Mahesh P; Chordia, Pravin; Das, Hillol K; Davis, Jack T C; Dekany, Richard G; Kasliwal, Mansi M; Kulkarni, Shrinivas R; Morton, Timothy D; Ofek, Eran O; Punnadi, Sujit

    2013-02-12

    a high-power laser beam in the direction of the astronomical target to create an artificial reference of known shape, also known as a 'laser guide star'. The Robo-AO laser adaptive optics system, employs a 10-W ultraviolet laser focused at a distance of 10 km to generate a laser guide star. Wavefront sensor measurements of the laser guide star drive the adaptive optics correction resulting in diffraction-limited images that have an angular resolution of ~0.1 arc seconds on a 1.5-m telescope.

  12. LDEF: Dosimetric measurement results (AO 138-7 experiment)

    NASA Astrophysics Data System (ADS)

    Bourrieau, J.

    1993-04-01

    One of the objectives of the AO 138-7 experiment on board the Long Duration Exposure Facility (LDEF) was a total dose measurement with Thermo Luminescent Detectors (TLD 100). Two identical packages, both of them including five TLD's inside various aluminum shields, are exposed to the space environment in order to obtain the absorbed dose profile. Radiation fluence received during the total mission length was computed, taking into account the trapped particles (AE8 and AP8 models during solar maximum and minimum periods) and the cosmic rays; due to the magnetospheric shielding the solar proton fluences are negligible on the LDEF orbit. The total dose induced by these radiations inside a semi infinite plane shield of aluminum are computed with the radiation transport codes available at DERTS. The dose profile obtained is in good agreement with the evaluation by E.V. Benton. TLD readings are performed after flight; due to the mission duration increase a post flight calibration was necessary in order to cover the range of the in flight induced dose. The results obtained, similar (plus or minus 30 percent) for both packages, are compared with the dose profile computation. For thick shields it seems that the measurements exceed the forecast (about 40 percent). That can be due to a cosmic ray and trapped proton contributions coming from the backside (assumed as perfectly shielded by the LDEF structure in the computation), or to an underestimate of the proton or cosmic ray fluences. A fine structural shielding analysis should be necessary in order to determine the origin of this slight discrepancy between forecast and in flight measurements. For the less shielded dosimeters, mainly exposed to the trapped electron flux, a slight overestimation of the dose (less than 40 percent) appears. Due to the dispersion of the TLD's response, this cannot be confirmed. In practice these results obtained on board LDEF, with less than a factor 1.4 between measurements and forecast

  13. Bringing the Visible Universe into Focus with Robo-AO

    NASA Astrophysics Data System (ADS)

    Baranec, Christoph; Riddle, Reed; Law, Nicholas M.; Ramaprakash, A. N.; Tendulkar, Shriharsh P.; Bui, Khanh; Burse, Mahesh P.; Chordia, Pravin; Das, Hillol K.; Davis, Jack T. C.; Dekany, Richard G.; Kasliwal, Mansi M.; Kulkarni, Shrinivas R.; Morton, Timothy D.; Ofek, Eran O.; Punnadi, Sujit

    2013-02-01

    focus a high-power laser beam in the direction of the astronomical target to create an artificial reference of known shape, also known as a 'laser guide star'. The Robo-AO laser adaptive optics system employs a 10-W ultraviolet laser focused at a distance of 10 km to generate a laser guide star. Wavefront sensor measurements of the laser guide star drive the adaptive optics correction resulting in diffraction-limited images that have an angular resolution of ~0.1 arc seconds on a 1.5-m telescope.

  14. Robo-AO: The First Autonomous Laser Guide Star Adaptive Optics System for Small Telescopes

    NASA Astrophysics Data System (ADS)

    Riddle, Reed L.; Baranec, C.; Ramaprakash, A. N.; Law, N.; Tendulkar, S.; Kulkarni, S.; Bui, K.; Burse, M.; Chordia, P.; Das, H.; Dekany, R.; Kasliwal, M.; Ofek, E.; Zolkower, J.

    2011-01-01

    Robo-AO will be the first fully autonomous laser guide star adaptive optics and science system. Specifically designed to take advantage of small (1 to 3 meter) telescopes, Robo-AO will deliver high angular resolution science in the visible and near infrared for up to hundreds of targets per night. This will enable the exploration of science programs not practical for larger aperture adaptive optics systems. This presentation discusses the current status of the Robo-AO project, including the laboratory testbed, laser guide star facility and plans for a demonstration of the fully autonomous system next year.

  15. Vibrations in MagAO: resonance sources identification and first approaches for modeling and control

    NASA Astrophysics Data System (ADS)

    Garcés, Javier; Zúñiga, Sebastián.; Close, Laird; Males, Jared; Morzinski, Katie; Escárate, Pedro; Castro, Mario; Marchioni, José; Rojas, Diego

    2016-07-01

    The Magellan Telescope Adaptive Optics System (MagAO) is subject to resonance effects induced by elements within the system instrumentation, such as fans and cooling pumps. Normalized PSDs are obtained through frequency-based analysis of closed-loop on-sky data, detecting and measuring vibration effects. Subsequently, a space-state model for the AO loop is obtained, using a standard AO loop scheme with an integrator-based controller and including the vibration effects as disturbances. Finally, a new control alternative is proposed, focusing on residual phase variance minimization through the design and simulation of an optimal LQG control approach.

  16. LDEF (Prelaunch), AO201 : Interplanetary Dust Experiment, Tray B12

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), AO201 : Interplanetary Dust Experiment, Tray B12 The prelaunch photograph shows the six (6) inch deep Interplanetary Dust Experiment (IDE) master control tray. The tray has three (3) mounting/cover plates elevated on fiberglass stand-offs to provide clearance and protection for hardware and electronics located underneath. The stand-offs also raise the plates to a level that minimizes shading of detectors by the tray sidewalls. The mounting plate located at the left hand end of the tray is populated with eighty (80) metaloxide-silicon (MOS) capacitor-type impact sensors and one (1) solar sensor that is located approximately in the center of the mounting plate. The IDE sensors are two (2) inch diameter MOS capacitor structures approximately 250 um thick. The detectors are formed by growing either 0.4um or 1.0um thick silicon oxide, SiO2, layer on the 250um thick, B-doped polished silicon wafer. The top metal contact, the visible surface, was formed by vapor deposition of 1000A of aluminum on the SiO2 surface. Aluminum was also vapor deposited on the backside to form the contact with the silicon substrate. Gold wires are bonded to the front and back aluminum layers for use in connecting the detectors to the circuits. The complete wafers, IDE detectors, are mounted on chromic anodized aluminum frames by bonding the detector backside to the aluminum frame with a space qualified RTV silicon adhesive, de-volatized RTV-511. The difference in colors of the detectors is caused by reflections in the metallized surfaces. A reflection of one of the technicians is visible in the three (3) rows of detector on the left hand side of the mounting plate. The solar sensor, located at the mounting plate center, consist of four (4) silicon solar cells connected in series and associated circuity bonded to an aluminum baseplate. The solar sensor registered each orbital sunrise independant of LDEF orientation at the time of sunrise. When IDE solar sensor data from the six

  17. Closeup of CO172AO8, showing section of building 211 closest to ...

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

    Close-up of CO-172-AO-8, showing section of building 211 closest to building 206. - Fitzsimons General Hospital, Quartermaster's Storehouse, Southwest Corner of East I Avenue & North Twelfth Street, Aurora, Adams County, CO

  18. Robo-AO: An Autonomous Laser Adaptive Optics and Science System

    NASA Astrophysics Data System (ADS)

    Baranec, Christoph; Riddle, Reed; Ramaprakash, A. N.; Law, Nicholas; Tendulkar, Shriharsh; Kulkarni, Shrinivas; Dekany, Richard; Bui, Khanh; Davis, Jack; Zolkower, Jeff; Fucik, Jason; Burse, Mahesh; Das, Hillol; Chordia, Pravin; Kasliwal, Mansi; Ofek, Eran; Morton, Timothy; Johnson, John

    2011-07-01

    Robo-AO, a fully autonomous, laser guide star adaptive optics and science system, is being commissioned at Palomar Observatory's 60-inch telescope. Here we discuss the instrument, scientific goals and results of initial on-sky operation.

  19. Te Ao Kori as Expressive Movement in Aotearoa New Zealand Physical Education Teacher Education (PETE): A Narrative Account

    ERIC Educational Resources Information Center

    Legge, Maureen

    2011-01-01

    A unique aspect of Aotearoa/New Zealand physical education is the inclusion of Maori culture in the form of te ao kori. Te ao kori translates to mean the world of movement and is represented by the interpretation of indigenous movement, games and pastimes. Participation in te ao kori means the sports-based normative frame of reference for physical…

  20. VizieR Online Data Catalog: Robo-AO Kepler planetary candidate survey. II. (Baranec+, 2016)

    NASA Astrophysics Data System (ADS)

    Baranec, C.; Ziegler, C.; Law, N. M.; Morton, T.; Riddle, R.; Atkinson, D.; Schonhut, J.; Crepp, J.

    2016-10-01

    We selected targets that we had not previously observed from the KOI Catalog based on the Q1-Q12 Kepler data (Rowe et al. 2015, Cat. J/ApJS/217/16). These targets were added to the Robo-AO intelligent observing queue and observed during the summer of 2013. We obtained high angular resolution images of 956 Kepler planet candidate host stars with the Robo-AO robotic laser AOs system over the course of 19 nights between 2013 July 21 and 2013 October 25, detailed in Table5. We also include 13 images from 2012 (2012 July 16-September 13) that required additional confirmation of the KOI position in the Robo-AO field of view. All the observations were performed in a queue-scheduled mode in combination with other science programs using the Robo-AO autonomous laser AO system mounted on the robotic 1.5m telescope at Palomar Observatory (exposure time: 90s; observation wavelengths: 600-950nm; FWHM resolution: 0.12''-0.15''; field of view: 44''*44''; pixel scale: 43.1mas/pix; detector format: 10242 pixels; targets observed/hour: 20). We obtained images of 50 KOIs with the NIRC2 instrument behind the Keck II AO system that were previously observed with Robo-AO and had evidence of a companion. Observations were conducted on 2013 June 25, 2013 August 24 and 25, 2014 August 17, and 2015 July 25 in the K, Ks, or Kp filters, and in the narrow mode of NIRC2 (9.952mas/pixel). (4 data files).

  1. OPERA, an automatic PSF reconstruction software for Shack-Hartmann AO systems: application to Altair

    NASA Astrophysics Data System (ADS)

    Jolissaint, Laurent; Veran, Jean-Pierre; Marino, Jose

    2004-10-01

    When doing high angular resolution imaging with adaptive optics (AO), it is of crucial importance to have an accurate knowledge of the point spread function associated with each observation. Applications are numerous: image contrast enhancement by deconvolution, improved photometry and astrometry, as well as real time AO performance evaluation. In this paper, we present our work on automatic PSF reconstruction based on control loop data, acquired simultaneously with the observation. This problem has already been solved for curvature AO systems. To adapt this method to another type of WFS, a specific analytical noise propagation model must be established. For the Shack-Hartmann WFS, we are able to derive a very accurate estimate of the noise on each slope measurement, based on the covariances of the WFS CCD pixel values in the corresponding sub-aperture. These covariances can be either derived off-line from telemetry data, or calculated by the AO computer during the acquisition. We present improved methods to determine 1) r0 from the DM drive commands, which includes an estimation of the outer scale L0 2) the contribution of the high spatial frequency component of the turbulent phase, which is not corrected by the AO system and is scaled by r0. This new method has been implemented in an IDL-based software called OPERA (Performance of Adaptive Optics). We have tested OPERA on Altair, the recently commissioned Gemini-North AO system, and present our preliminary results. We also summarize the AO data required to run OPERA on any other AO system.

  2. East Asian winter temperature variation associated with the combined effects of AO and WP pattern

    NASA Astrophysics Data System (ADS)

    Park, Hye-Jin; Ahn, Joong-Bae

    2016-04-01

    The combined effects of the Arctic Oscillation (AO) and Western Pacific (WP) teleconnection pattern on the East Asian winter monsoon (EAWM) over the last 56 years (1958/59-2013/2014) were investigated using NCEP/NCAR reanalysis data (Park and Ahn, 2015). The study results revealed that the effect of the AO on winter temperature in East Asia could be changed depending on the phases of the WP pattern in the North Pacific. The negative relationship between the EAWM and the AO increased when the AO and WP were in-phase with each other. Hence, when winter negative (positive) AO was accompanied by negative (positive) WP, negative (positive) temperature anomalies were dominant across the entire East Asia region. Conversely, when the AO and WP were of-of-phase, the winter temperature anomaly in East Asia did not show distinct changes. Furthermore, from the perspective of stationary planetary waves, the zonal wavenumber-2 patterns of sea level pressure and geopotential height at 500hPa circulation strengthened when the AO and WP were in-phase but were not significant for the out-of-phase condition. It explained the possible mechanism of the combined effects of the AO and WP on the circulation related to EAWM. Reference Park, H.-J., and J.-B. Ahn (2015) Combined effect of the Arctic Oscillation and the Western Pacific pattern on East Asia winter temperature, Clim. Dyn. DOI:10.1007/s00382-015-2763-2. Acknowledgements This work was funded by the Korea Meteorological Administration Research and Development Program under grant KMIPA2015-2081.

  3. Robo-AO: Initial results from the first autonomous laser guide star adaptive optics instrument

    NASA Astrophysics Data System (ADS)

    Riddle, R.; Baranec, C.; Law, N. M.; Ramaprakash, A. N.; Tendulkar, S.; Hogstrom, K.; Bui, K.; Burse, M.; Chordia, P.; Das, H.; Dekany, R.; Kulkarni, S.; Punnadi, S.; Smith, R.

    2014-03-01

    Large surveys, such as the Kepler mission and Palomar Transient Factory, are discovering upwards of thousands of objects which require further characterization at angular resolutions significantly finer than normally allowed by atmospheric seeing. The demands on precious space-based observatories (i.e. Hubble Space Telescope) and large telescopes with adaptive optics (AO) systems (i.e. Keck, VLT, Gemini) leave them generally unavailable for high angular resolution surveys of more than a few hundred targets at a time. To address the gap between scientific objects and available telescopes, we have developed Robo-AO, the first robotic laser AO system, as an economical and efficient imaging instrument for the more readily available 1-3 m class telescopes. The Robo-AO system system demonstrates angular resolutions approaching the visible diffraction limit of the Palomar 60-inch telescope. Observations of over 200 stellar objects per night have routinely been performed, with target-to-target observation overheads of less than 1.5 minutes. Scientific programs requiring high-resolution follow-up characterization of several thousands of targets can thus be executed in mere weeks, and Robo-AO has already completed the three largest AO surveys to date.

  4. Snow-(N)AO relationship revisited over the whole twentieth century

    NASA Astrophysics Data System (ADS)

    Douville, H.; Peings, Y.; Saint-Martin, D.

    2017-01-01

    Several studies suggest that the Siberian snow cover in fall is a source of predictability of the Arctic Oscillation (AO) in winter. Although a plausible dynamical mechanism was proposed, the robustness of this relationship was recently challenged. Here we use two atmospheric reanalyses to revisit the snow-AO relationship and its modulation across the whole twentieth century. While our results support a stratospheric pathway mechanism, they show that the snow-AO relationship has only emerged in the 1970s and should be rather analyzed as a contrasted multidecadal behavior of the North Atlantic Oscillation (NAO) and Pacific North America pattern. They confirm that the quasi-biennial oscillation is a plausible candidate for the modulation of the snow-(N)AO relationship across the twentieth century, but they further show that this modulation might be a purely stochastic effect. Therefore, they emphasize the limitations of any empirical prediction of the (N)AO only based on snow and/or sea ice predictors.

  5. SAXO, the SPHERE extreme AO system: on-sky final performance and future improvements

    NASA Astrophysics Data System (ADS)

    Fusco, T.; Sauvage, J.-F.; Mouillet, D.; Costille, A.; Petit, C.; Beuzit, J.-L.; Dohlen, K.; Milli, J.; Girard, J.; Kasper, M.; Vigan, A.; Suarez, M.; Soenke, C.; Downing, M.; N'Diaye, M.; Baudoz, P.; Sevin, A.; Baruffolo, A.; Schmid, H.-M.; Salasnich, B.; Hugot, E.; Hubin, N.

    2016-07-01

    The SPHERE (Spectro-Polarimetric High-contrast Exoplanet Research) instrument aims at detecting extremely faint sources (giant extrasolar planets) in the vicinity of bright stars1. Such a challenging goal requires the use of a very-high-order performance Adaptive Optics [AO] system feeding the scientific instruments with a quasi-perfect flat wave front corrected from all the atmospheric turbulence and internal defects. This AO system, called SAXO (Sphere Ao for eXoplanet Observation) is the heart of the instrument, a heart beating 1200 time per second and providing unprecedented image quality for a large ground based telescope at optical/near infrared wavelength. We will present the latest results obtained on-sky, demonstrating its exceptional performance (in terms of correction quality, stability and robustness) and tremendous potentiality for high contrast imaging and more specifically for exoplanet discovery.

  6. Deep-water sponges (Porifera) from Bonaire and Klein Curaçao, Southern Caribbean.

    PubMed

    Van Soest, Rob W M; Meesters, Erik H W G; Becking, Leontine E

    2014-10-29

    Four submersible dives off the coast of Bonaire (Caribbean Netherlands) and Klein Curaçao (Curaçao) to depths of 99.5-242 m, covering lower mesophotic and upper dysphotic zones, yielded 52 sponge specimens belonging to 31 species. Among these we identified 13 species as new to science. These are Plakinastrella stinapa n. sp., Pachastrella pacoi n. sp., Characella pachastrelloides n. sp., Geodia curacaoensis n. sp., Caminus carmabi n. sp., Discodermia adhaerens n. sp., Clathria (Microciona) acarnoides n. sp., Antho (Acarnia) pellita n. sp., Parahigginsia strongylifera n. sp., Calyx magnoculata n. sp., Neopetrosia dutchi n. sp., Neopetrosia ovata n. sp. and Neopetrosia eurystomata n. sp. We also report an euretid hexactinellid, which belongs to the rare genus Verrucocoeloidea, recently described (2014) as V. liberatorii Reiswig & Dohrmann. The remaining 18 already known species are all illustrated by photos of the habit, either in situ or 'on deck', but only briefly characterized in an annotated table to confirm their occurrence in the Southern Caribbean. The habitat investigated-steep limestone rocks, likely representing Pleistocene fossil reefs--is similar to deep-water fossil reefs at Barbados of which the sponges were sampled and studied by Van Soest and Stentoft (1988). A comparison is made between the two localities, showing a high degree of similarity in sponge composition: 53% of the present Bonaire-Klein Curaçao species were also retrieved at Barbados. At the level of higher taxa (genera, families) Bonaire-Klein Curaçao shared approximately 80% of its lower mesophotic and upper dysphotic sponge fauna with Barbados, despite a distance between them of 1000 km, indicating high faunal homogeneity. We also preliminarily compared the shallow-water (euphotic) sponge fauna of Curaçao with the combined data available for the Barbados, Bonaire and Klein Curaçao mesophotic and upper dysphotic sponges, which resulted in the conclusion that the two faunas show only

  7. Novel algorithm implementations in DARC: the Durham AO real-time controller

    NASA Astrophysics Data System (ADS)

    Basden, Alastair; Bitenc, Urban; Jenkins, David

    2016-07-01

    The Durham AO Real-time Controller has been used on-sky with the CANARY AO demonstrator instrument since 2010, and is also used to provide control for several AO test-benches, including DRAGON. Over this period, many new real-time algorithms have been developed, implemented and demonstrated, leading to performance improvements for CANARY. Additionally, the computational performance of this real-time system has continued to improve. Here, we provide details about recent updates and changes made to DARC, and the relevance of these updates, including new algorithms, to forthcoming AO systems. We present the computational performance of DARC when used on different hardware platforms, including hardware accelerators, and determine the relevance and potential for ELT scale systems. Recent updates to DARC have included algorithms to handle elongated laser guide star images, including correlation wavefront sensing, with options to automatically update references during AO loop operation. Additionally, sub-aperture masking options have been developed to increase signal to noise ratio when operating with non-symmetrical wavefront sensor images. The development of end-user tools has progressed with new options for configuration and control of the system. New wavefront sensor camera models and DM models have been integrated with the system, increasing the number of possible hardware configurations available, and a fully open-source AO system is now a reality, including drivers necessary for commercial cameras and DMs. The computational performance of DARC makes it suitable for ELT scale systems when implemented on suitable hardware. We present tests made on different hardware platforms, along with the strategies taken to optimise DARC for these systems.

  8. Rise of the Machines: Automated Laser Guide Star Adaptive Optics Observations of Thousands of Objects with Robo-AO

    NASA Astrophysics Data System (ADS)

    Riddle, Reed L.; Baranec, C.; Law, N. M.; Tendulkar, S. P.; Ramaprakash, A. N.; Kulkarni, S. R.; Dekany, R.; Bui, K.; Burse, M.; Das, H.; Punnadi, S.; Chordia, P.

    2013-01-01

    Robo-AO is the first fully automated laser guide star adaptive optics instrument. Robo-AO has completed thousands of automated AO observations at the visible diffraction limit for several scientific programs during its first semester of science observations. These programs include: the Ultimate Binarity Survey to examine stellar binarity properties across the main sequence and beyond; a survey of 1,000 Kepler objects of interest; the multiplicity of solar type stars; and several programs for high precision astrometric observations. A new infrared camera is under development for Robo-AO, and a clone of the system is in the planning stages. This presentation will discuss the Robo-AO instrument capabilities, summarize the science programs undertaken, and discuss the future of Robo-AO.

  9. The Robo-AO software: fully autonomous operation of a laser guide star adaptive optics and science system

    NASA Astrophysics Data System (ADS)

    Riddle, Reed L.; Burse, Mahesh P.; Law, Nicholas M.; Tendulkar, Shriharsh P.; Baranec, Christoph; Rudy, Alexander R.; Sitt, Marland; Arya, Ankit; Papadopoulos, Athanasios; Ramaprakash, A. N.; Dekany, Richard G.

    2012-07-01

    Robo-AO is the first astronomical laser guide star adaptive optics (AO) system designed to operate completely independent of human supervision. A single computer commands the AO system, the laser guide star, visible and near-infrared science cameras (which double as tip-tip sensors), the telescope, and other instrument functions. Autonomous startup and shutdown sequences as well as concatenated visible observations were demonstrated in late 2011. The fully robotic software is currently operating during a month long demonstration of Robo- AO at the Palomar Observatory 60-inch telescope.

  10. Is the BL Lacertae object AO 0235 + 164 being lensed by its intervening MG II absorber?

    NASA Astrophysics Data System (ADS)

    Abraham, Roberto G.; Crawford, Carolin S.; Merrifield, Michael R.; Hutchings, John B.; McHardy, Ian M.

    1993-09-01

    We report the results of deep CFHT imaging of the BL Lac object AO 0235 + 164. This object exhibits Mg II absorption features and has been considered to be the best candidate for a microlensed BL Lac on the basis of its multiple redshift systems, decentered host, and extreme apparent superluminal motion. We test the microlensing hypothesis by modeling our images with a two-dimensional image fitting routine. The resulting best-fit models allow us to put strong constraints on lensing scenarios for this object, and to put limits on the mass-to-light ratio of the foreground Mg II absorbing galaxy. We conclude that, while AO 0235 + 164 is almost certainly being weakly amplified by macrolensing, microlensing by stars in the foreground lens is unnecessary in order to explain the observed properties of AO 0235 + 164. These results are combined with the work of previous authors to suggest that the (probably lensing) Mg II absorbing galaxy in the foreground of AO 0235 + 164 is embedded in a cooling flow.

  11. Atomic Oxygen (AO) and Nitrogen (AN) In-situ Flux Sensor

    DTIC Science & Technology

    2016-03-10

    Grant # FA9550-01-1-0433 M. R. Beasley, PI Stanford University Project Title: Atomic Oxygen (AO) and Nitrogen (AN) In-situ Flux Sensor ...intensity. The major technological challenge is the VUV nature of the relevant spectral lines in the case of oxygen and nitrogen. A LabVIEW™-based data

  12. Performance of a MEMS-based AO-OCT system using Fourier Reconstruction

    SciTech Connect

    Evans, J; Zawadzki, R; Jones, S; Olivier, S; Werner, J S

    2009-01-21

    Adaptive optics (AO) and optical coherence tomography (OCT) are powerful imaging modalities that, when combined, can provide high-resolution (3.5 {micro}m isotropic), 3-D images of the retina. The AO-OCT system at UC Davis has demonstrated the utility of this technology for microscopic, volumetric, in vivo retinal imaging. The current system uses an AOptix bimorph deformable mirror (DM) for low-order, high-stroke correction and a 140-actuator Boston Micromachines DM for high-order correction. Developments to improve performance or functionality of the instrument are on-going. Based on previous work in system characterization we have focused on improved AO control. We present preliminary results and remaining challenges for a newly implemented Fourier transform reconstructor (FTR). The previously reported error budget analysis is also reviewed and updated, with consideration of how to improve both the amount of residual error and the robustness of the system. Careful characterization of the AO system will lead to improved performance and inform the design of future systems.

  13. GPS-Based Navigation And Orbit Determination for the AMSAT AO-40 Satellite

    NASA Technical Reports Server (NTRS)

    Davis, George; Moreau, Michael; Carpenter, Russell; Bauer, Frank

    2002-01-01

    The AMSAT OSCAR-40 (AO-40) spacecraft occupies a highly elliptical orbit (HEO) to support amateur radio experiments. An interesting aspect of the mission is the attempted use of GPS for navigation and attitude determination in HEO. Previous experiences with GPS tracking in such orbits have demonstrated the ability to acquire GPS signals, but very little data were produced for navigation and orbit determination studies. The AO-40 spacecraft, flying two Trimble Advanced Navigation Sensor (TANS) Vector GPS receivers for signal reception at apogee and at perigee, is the first to demonstrate autonomous tracking of GPS signals from within a HEO with no interaction from ground controllers. Moreover, over 11 weeks of total operations as of June 2002, the receiver has returned a continuous stream of code phase, Doppler, and carrier phase measurements useful for studying GPS signal characteristics and performing post-processed orbit determination studies in HEO. This paper presents the initial efforts to generate AO-40 navigation solutions from pseudorange data reconstructed from the TANS Vector code phase, as well as to generate a precise orbit solution for the AO-40 spacecraft using a batch filter.

  14. Effects of adrenergic agents on the expression of zebrafish (Danio rerio) vitellogenin Ao1

    SciTech Connect

    Yin Naida; Jin Xia; He Jiangyan; Yin Zhan

    2009-07-01

    Teleost vitellogenins (VTGs) are large multidomain apolipoproteins, traditionally considered to be estrogen-responsive precursors of the major egg yolk proteins, expressed and synthesized mainly in hepatic tissue. The inducibility of VTGs has made them one of the most frequently used in vivo and in vitro biomarkers of exposure to estrogen-active substances. A significant level of zebrafish vtgAo1, a major estrogen responsive form, has been unexpectedly found in heart tissue in our present studies. Our studies on zebrafish cardiomyopathy, caused by adrenergic agonist treatment, suggest a similar protective function of the cardiac expressed vtgAo1. We hypothesize that its function is to unload surplus intracellular lipids in cardiomyocytes for 'reverse triglyceride transportation' similar to that found in lipid transport proteins in mammals. Our results also demonstrated that zebrafish vtgAo1 mRNA expression in heart can be suppressed by both {alpha}-adrenergic agonist, phenylephrine (PE) and {beta}-adrenergic agonist, isoproterenol (ISO). Furthermore, the strong stimulation of zebrafish vtgAo1 expression in plasma induced by the {beta}-adrenergic antagonist, MOXIsylyl, was detected by Enzyme-Linked ImmunoSorbent Assay (ELISA). Such stimulation cannot be suppressed by taMOXIfen, an antagonist to estrogen receptors. Thus, our present data indicate that the production of teleost VTG in vivo can be regulated not only by estrogenic agents, but by adrenergic signals as well.

  15. Extreme AO: The future of high-contrast imaging with adaptive optics

    NASA Astrophysics Data System (ADS)

    Macintosh, B.

    2001-05-01

    Title: Extreme AO: The future of high-contrast-imaging with adaptive optics. Adaptive optics (AO) partially cancels wavefront aberrations caused by atmospheric turbulence and can allow ground-basd telescope to reach their full diffraction-limited resolution. A fundamental limitation of all AO systems is that they have little effect on the atmospheric scattered light halo beyond a control radius roughly given by the wavelength of interest divided by the effective actuator spaceing d; for typical modern AO systems, d=60 cm and the control radius is about 0.6 arcseconds at H band. AO can still enhance contrast even beyond this radius, especially for point-source companions, by concentrating the light from the companion into a diffraction-limited spike, but the residual light remains a limitation on our ability to carry out high-contrast imaging from the ground. We will discuss potential improvements to AO over the next decade and the science they will enable. First, in the near term, high-order AO systems will soon be operational on most 8-10 m telescopes; such systems are theoretically capable of directly detecting extrasolar planets in wide (20-150 AU) orbits, and the capabilities and limitations of these systems will be discussed. Second, in the moderate term, new instrument technologies could substantially increase the performance of these systems, including exotic phase-based coronagraphs or "dark speckle" techniques. Third, it will soon be possible to construct "extreme" adaptive optics (EAO) systems, with many thousand actuators and d=5-20cm, capable of more deeply surpressing the atmospheric halo out to a much larger radius than current systems. Coronagraphs and EAO will substantially increase our sensitivity to diffuse circumstellar dust and could conceivably reach the contrast levels necessary to see giant plants around a handful of nearby stars. Finally, within a decade construction should be underway on next-generation extremely large (25-100 m) telescopes

  16. Termination of Pregnancy in Curaçao: Need for Improvement of Sexual and Reproductive Healthcare

    PubMed Central

    Boersma, Adriana A.; Alberts, Jantina F.; de Bruijn, Jeanne; Jong, Betty Meyboom-de; Kleiverda, Gunilla

    2012-01-01

    Background: In Curaçao Termination of Pregnancy (TOP) is still forbidden by law, although a policy of tolerance has been stipulated since 1999. This paper is about the prevalence of TOP and about its health complications. These data on TOP are officially unknown but are suspected to be rather high. Methods: One year registration of illegal performed termination of pregnancy cases by all general physicians (GPs) practicing TOP in Curaçao. The registration included patient characteristics according to the model of the National Abortion Registration in The Netherlands, adjusted to the local Curaçao situation. Socio demographic characteristics, number of previous pregnancies and TOPs, pregnancy duration, contraception methods and reason for failure were registered. The comparative part of the research compares TOP rates of Curaçao with those of Antillean women in the Netherlands. The gynaecologists in the referral hospital registered complications requiring hospital admission after TOP. Results: All GPs performing TOP participated and the majority registered extensively. The total number of registered TOP was 1126. 666 of the 1126 were registered using the local adjusted Abortion Registration Model. With 30.000 women aged between 15 and 45 living in Curaçao, the TOP rate was at least 38 (per 1000 in that age category), comparable to rates for Antillean women in the Netherlands. Mean age was 26.9 years. Nearly half (47%) had one or more TOPs before; the majority (53%) was less than 7 weeks pregnant and two third (67%) had one or more children. Two third of the women did not use contraception (63%). For those using contraception, main reason for failure was inconsistent use (50%). There were 14 hospital admissions due to complications of TOP. Conclusion: The number of TOP is high in Curaçao and comparable to (first generation) Antillean women living abroad in the Netherlands. Most unintended pregnancies originated from no or inconsistent use of reliable

  17. Identification and calibration of the interaction matrix parameters for AO and MCAO systems

    NASA Astrophysics Data System (ADS)

    Neichel, Benoit; Parisot, Amelie; Petit, Cyril; Fusco, Thierry; Rigaut, François

    2012-07-01

    New tomographic Adaptive Optics (AO) concepts require a good knowledge of the system geometry and characteristics. These parameters are used to feed the tomographic reconstructors. In this paper we present a method to precisely identify the parameters required to construct an accurate synthetic set of models such as inuence functions, mis-registrations, directions of analysis or altitude of the DMs. The method is based on a multiparameter t of the interaction matrix. This identication method nds also its application in high contrast AO systems, such as SPHERE : in that case it is used as a diagnostic tool in order to precisely realign the system. The method has been tested and successfully implemented on HOMER, SPHERE and GeMS. Experimental results for these three systems are presented.

  18. The role of AO external fixation in proximal femoral osteotomies in the pediatric neuromuscular population.

    PubMed

    Handelsman, John E; Weinberg, Jacob; Razi, Afshin; Mulley, Debra A

    2004-09-01

    Internal fixation in proximal femoral osteotomies using traditional devices may be sub-optimal in children with neuromuscular disorders who have small or osteopenic bone. In this population, between 1988 and 2000, we performed 36 proximal femoral varus osteotomies in 28 patients. These were controlled by the AO external fixator. The average age at surgery was 7 years (range, 2-13 years). A mean varus correction of 34 degrees (range, 15-90 degrees) was obtained. Complications consisted of one superficial pin tract infection, one skin breakdown, and one non-union. Other than the non-union, all osteotomies were stable at the time of the fixator removal. The AO external fixator is an effective alternative in maintaining corrective proximal femoral osteotomies in children with fragile bones.

  19. Analysis of Alternatives (AoA) for KC-135 Recapitalization. Executive Summary

    DTIC Science & Technology

    2006-01-01

    Integrative research projects and work on modeling and simulation are conducted on a PAF-wide basis. The research reported here was prepared within the...Electric and Pratt & Whitney. The Air Force’s Aeronautical Systems Center, part of Air Force Materiel Command, proposed three new- design tankers that were...and Analysis Division (AMC/A59) made significant contributions to the AoA’s effectiveness analysis, especially in the detailed modeling of tanker

  20. Real-time control for the high order, wide field DRAGON AO test bench

    NASA Astrophysics Data System (ADS)

    Basden, Alastair; Bharmal, Nazim A.; Bitenc, Urban; Dipper, Nigel; Morris, Tim; Myers, Richard; Reeves, Andrew; Younger, Eddy

    2014-07-01

    DRAGON is a high order, wide field AO test-bench at Durham. A key feature of DRAGON is the ability to be operated at real-time rates, i.e. frame rates of up to 1kHz, with low latency to maintain AO performance. Here, we will present the real-time control architecture for DRAGON, which includes two deformable mirrors, eight wavefront sensors and thousands of Shack-Hartmann sub-apertures. A novel approach has been taken to allow access to the wavefront sensor pixel stream, reducing latency and peak computational load, and this technique can be implemented for other similar wavefront sensor cameras with no hardware costs. We report on experience with an ELT-suitable wavefront sensor camera. DRAGON will form the basis for investigations into hardware acceleration architectures for AO real-time control, and recent work on GPU and many-core systems (including the Xeon Phi) will be reported. Additionally, the modular structure of DRAGON, its remote control capabilities, distribution of AO telemetry data, and the software concepts and architecture will be reported. Techniques used in DRAGON for pixel processing, slope calculation and wavefront reconstruction will be presented. This will include methods to handle changes in CN2 profile and sodium layer profile, both of which can be modelled in DRAGON. DRAGON software simulation techniques linking hardware-in-the-loop computer models to the DRAGON real-time system and control software will also be discussed. This tool allows testing of the DRAGON system without requiring physical hardware and serves as a test-bed for ELT integration and verification techniques.

  1. Assessment of Assembling Objects (AO) for Improving Predictive Performance of the Armed Forces Qualification Test

    DTIC Science & Technology

    2011-04-01

    Although the ASVAB has not historically been predictive of attrition ( Laurence , Naughton, & Harris, 1996), the AO subtest has indeed shown...internal consistency (e.g., Earles & Ree , 1992). Alderton and colleagues (1997) found that PC had fairly low test-retest reliability, which was well... Ree (1992) found that WK is a slightly better predictor of course grades than PC across a variety of job types. Mirroring the research on the two

  2. Bridging FPGA and GPU technologies for AO real-time control

    NASA Astrophysics Data System (ADS)

    Perret, Denis; Lainé, Maxime; Bernard, Julien; Gratadour, Damien; Sevin, Arnaud

    2016-07-01

    Our team has developed a common environment for high performance simulations and real-time control of AO systems based on the use of Graphics Processors Units in the context of the COMPASS project. Such a solution, based on the ability of the real time core in the simulation to provide adequate computing performance, limits the cost of developing AO RTC systems and makes them more scalable. A code developed and validated in the context of the simulation may be injected directly into the system and tested on sky. Furthermore, the use of relatively low cost components also offers significant advantages for the system hardware platform. However, the use of GPUs in an AO loop comes with drawbacks: the traditional way of offloading computation from CPU to GPUs - involving multiple copies and unacceptable overhead in kernel launching - is not well suited in a real time context. This last application requires the implementation of a solution enabling direct memory access (DMA) to the GPU memory from a third party device, bypassing the operating system. This allows this device to communicate directly with the real-time core of the simulation feeding it with the WFS camera pixel stream. We show that DMA between a custom FPGA-based frame-grabber and a computation unit (GPU, FPGA, or Coprocessor such as Xeon-phi) across PCIe allows us to get latencies compatible with what will be needed on ELTs. As a fine-grained synchronization mechanism is not yet made available by GPU vendors, we propose the use of memory polling to avoid interrupts handling and involvement of a CPU. Network and Vision protocols are handled by the FPGA-based Network Interface Card (NIC). We present the results we obtained on a complete AO loop using camera and deformable mirror simulators.

  3. The investigation of determination asteroids positions errors by observations of telescope SBG AO UFU

    NASA Astrophysics Data System (ADS)

    Kaizer, G. T.; Skripnichenko, P. V.

    2013-07-01

    The article is about investigation of influence astrometric CCD image processing conditions on the accuracy of determining the positions of asteroids. The main this research's problem is dependence of calculatedasteroids coordinates error from used in the processing mathematical model that approximated the image of the objects on the CCD image. In thearticle described of the effect of Lorentz and Moffatt profiles on the accuracy ofasteroids positions determining by the observation from SBG AO UFU.

  4. World-wide deployment of Robo-AO visible-light robotic laser adaptive optics systems

    NASA Astrophysics Data System (ADS)

    Baranec, Christoph; Riddle, Reed; Law, Nicholas Michael; Lu, Jessica R.; Tonry, John; Tully, R. Brent; Wright, Shelley; Kulkarni, Shrinivas; Severson, Scott; Choi, Philip; Ramaprakash, A.; Chun, Mark; Connelley, Mike; Tokunaga, Alan; Hall, Donald

    2015-08-01

    In the next few years, several modest-sized telescopes around the world will be upgraded with autonomous laser adaptive optics systems based on the Robo-AO prototype deployed at the Palomar Observatory 1.5-m telescope. The prototype commenced scientific operations in June 2012 and more than 19,000 observations have since been performed at the ~0.12" visible-light diffraction limit. We are planning to move the prototype system to the 2.1-m telescope at Kitt Peak for a 3-year deployment which will serve a consortium of users including Caltech, the University of Hawai`i, IUCAA, NCU and institutions in China. Additionally, 2 months per year will be made available to the US astronomical community.New Robo-AO systems are in various stages of development: a clone by IUCAA for the 2-m IGO telescope in India; a natural guide star variant, KAPAO, by Pomona College at the 1-m Table Mountain telescope in California; and second generation Robo-AO systems are planned for the 3-m IRTF and 2.2-m University of Hawai'i telescopes on Maunakea, Hawai`i. The latter will exploit Maunakea's excellent observing conditions to provide higher Strehl ratios, sharper imaging, ~0.07", and correction to lambda = 400 nm. An additional infrared integral-field spectrograph will be fed by the UH 2.2-m Robo-AO system to quickly classify transients, such as supernovae and asteroids, discovered by the ATLAS system in Hawai`i.

  5. AOS: adaptive offset time scheduling for TCP fairness in optical burst-switched network

    NASA Astrophysics Data System (ADS)

    Zheng, Hongyun; Zhao, Yongxiang; Chen, Changjia

    2005-11-01

    Optical Burst-switched (OBS) is a promising switching technology and expected to support the future Internet backbone with dramatically increasing bandwidth demand. In an OBS network, burst contention causes burst loss due to bufferless nature of OBS core network. This kind of burst loss will interact with the above TCP layer. In this paper, we study the impact of this interaction on TCP fairness. We find significant unfairness among TCP flows that share the OBS core network, i.e. one flow obtains higher throughput while any others with much lower throughputs. The cause is the phenomenon called "the bigger eats the smaller (BES)", in which a TCP flow with higher rate occasionally will "see" less burst contentions and increase its rate further, while a TCP with lower rate will see more burst contentions and decrease its rate continually. Discuss a simple model to explain BES and verify that a continuous sequence of bursts will enhance BES. Then observe that offset time will be a good choice to control TCP fairness by a curve of unfairness control with offset time adjustment. Finally an adaptive offset time scheduling (AOS) algorithm is proposed. AOS assigns burst offset time value adaptive to the rate of TCP flow. The simulation results show that the fairness can be significantly improved by our AOS scheme.

  6. AO modelling for wide-field E-ELT instrumentation using Monte-Carlo simulation

    NASA Astrophysics Data System (ADS)

    Basden, Alastair; Morris, Simon; Morris, Tim; Myers, Richard

    2014-08-01

    Extensive simulations of AO performance for several E-ELT instruments (including EAGLE, MOSAIC, HIRES and MAORY) have been ongoing using the Monte-Carlo Durham AO Simulation Package. We present the latest simulation results, including studies into DM requirements, dependencies of performance on asterism, detailed point spread function generation, accurate telescope modelling, and studies of laser guide star effects. Details of simulations will be given, including the use of optical models of the E-ELT to generate wave- front sensor pupil illumination functions, laser guide star modelling, and investigations of different many-layer atmospheric profiles. We discuss issues related to ELT-scale simulation, how we have overcome these, and how we will be approaching forthcoming issues such as modelling of advanced wavefront control, multi-rate wavefront sensing, and advanced treatment of extended laser guide star spots. We also present progress made on integrating simulation with AO real-time control systems. The impact of simulation outcomes on instrument design studies will be discussed, and the ongoing work plan presented.

  7. SCExAO: the most complete instrument to characterize exoplanets and stellar environments

    NASA Astrophysics Data System (ADS)

    Lozi, Julien; Guyon, Olivier; Jovanovic, Nemanja; Singh, Garima; Doughty, Danielle; Pathak, Prashant; Goebel, Sean; Kudo, Tomoyuki

    2015-12-01

    The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument, currently under development for the Subaru Telescope, optimally combines state-of-the-art technologies to directly study exoplanets and stellar environments at the diffraction limit, both in visible and infrared light (0.6 to 2.4 um). The instrument already includes an ultra-fast visible pyramid wavefront sensor operating at 3.5 kHz, a 2k-actuator deformable mirror, a set of optimal coronagraphs that can work as close as 1 l/D, a low-order wavefront sensor, a high-speed speckle control, and two visible interferometric modules, VAMPIRES and FIRST. Stability of the wavefront correction has already been demonstrated on sky, and SCExAO is already producing scientific results. After the integration of the Integral Field Spectrograph (IFS) CHARIS and a Microwave Kinetic Inductance Detector (MKID) in 2016, SCExAO will be one of the most powerful and effective tools for characterizing exoplanets and disks.

  8. AO/NAO Response to Climate Change. 1; Respective Influences of Stratospheric and Tropospheric Climate Changes

    NASA Technical Reports Server (NTRS)

    Rind, D.; Perlwitz, J.; Lonergan, P.

    2005-01-01

    We utilize the GISS Global Climate Middle Atmosphere Model and 8 different climate change experiments, many of them focused on stratospheric climate forcings, to assess the relative influence of tropospheric and stratospheric climate change on the extratropical circulation indices (Arctic Oscillation, AO; North Atlantic Oscillation, NAO). The experiments are run in two different ways: with variable sea surface temperatures (SSTs) to allow for a full tropospheric climate response, and with specified SSTs to minimize the tropospheric change. The results show that tropospheric warming (cooling) experiments and stratospheric cooling (warming) experiments produce more positive (negative) AO/NAO indices. For the typical magnitudes of tropospheric and stratospheric climate changes, the tropospheric response dominates; results are strongest when the tropospheric and stratospheric influences are producing similar phase changes. Both regions produce their effect primarily by altering wave propagation and angular momentum transports, but planetary wave energy changes accompanying tropospheric climate change are also important. Stratospheric forcing has a larger impact on the NAO than on the AO, and the angular momentum transport changes associated with it peak in the upper troposphere, affecting all wavenumbers. Tropospheric climate changes influence both the A0 and NAO with effects that extend throughout the troposphere. For both forcings there is often vertical consistency in the sign of the momentum transport changes, obscuring the difference between direct and indirect mechanisms for influencing the surface circulation.

  9. Using the Fingerprinting Method to Customize RTLS Based on the AoA Ranging Technique

    PubMed Central

    Jachimczyk, Bartosz; Dziak, Damian; Kulesza, Wlodek J.

    2016-01-01

    Real-time Locating Systems (RTLSs) have the ability to precisely locate the position of things and people in real time. They are needed for security and emergency applications, but also for healthcare and home care appliances. The research aims for developing an analytical method to customize RTLSs, in order to improve localization performance in terms of precision. The proposed method is based on Angle of Arrival (AoA), a ranging technique and fingerprinting method along with an analytically defined uncertainty of AoA, and a localization uncertainty map. The presented solution includes three main concerns: geometry of indoor space, RTLS arrangement, and a statistical approach to localization precision of a pair of location sensors using an AoA signal. An evaluation of the implementation of the customized RTLS validates the analytical model of the fingerprinting map. The results of simulations and physical experiments verify the proposed method. The research confirms that the analytically established fingerprint map is the valid representation of RTLS’ performance in terms of precision. Furthermore, the research demonstrates an impact of workspace geometry and workspace layout onto the RTLS’ performance. Moreover, the studies show how the size and shape of a workspace and the placement of the calibration point affect the fingerprint map. Withal, the performance investigation defines the most effective arrangement of location sensors and its influence on localization precision. PMID:27314354

  10. Correction of shortening and/or angular deformities by distraction osteogenesis using AO-tubular fixator.

    PubMed

    Sangkaew, Chanchit

    2003-01-01

    Eighteen patients (20 bony segments) who had shortening and/or angular deformities were treated by distraction osteogenesis using AO-tubular external fixator. The mean angular correction was 18.9 degrees (range, 8-40 degrees). Of the group in whom shortening and angulation was corrected, the mean length gained was 4.2 cm (3-6 cm). The mean treatment time was 4.9 months (range, 2-13 months) and the mean follow-up was 12 months after removal of the fixator (range, 3-30 months). Delayed union with loosening of the fixator occurred in one patient which resulted in residual shortening of 1.5 cm. The author's technique of distraction osteogenesis using AO-tubular fixator with the new distraction rate of 1 mm/48 h (1 mm/step) could adequately correct shortening and/or angular deformities. No extra equipment was needed other than the readily-available AO-tubular fixation systems. No serious complications such as neurovascular injury were encountered.

  11. New classification system for long-bone fractures supplementing the AO/OTA classification.

    PubMed

    Garnavos, Christos; Kanakaris, Nikolaos K; Lasanianos, Nikolaos G; Tzortzi, Paraskevi; West, Robert M

    2012-05-01

    This article describes a novel, clinically oriented classification system for long-bone fractures that is simple, reliable, and useful to predict treatment method, complications, and outcome. The reliability and memorability of the new classification were statistically tested and compared with the AO-Müller/Orthopaedic Trauma Association (AO/OTA) long-bone fracture classification. The proposed classification system was also clinically validated with a targeted pilot study designed for content and clinical outcome retrospectively reviewing 122 closed tibial shaft fractures, which were used as a representative paradigm of long-bone fractures. Statistical evaluation showed that the proposed classification system had improved inter- and intraobserver variation agreement and easier memorability compared with the AO/OTA classification system. The clinical validation study showed its predictive value regarding selection of treatment method, complication rate, and injury outcome.The proposed classification system proved simple, reliable, and memorable. Its clinical value appeared strong enough to justify the organization of larger studies for a complete assessment of its clinical usefulness for all long-bone fractures.

  12. Using the Fingerprinting Method to Customize RTLS Based on the AoA Ranging Technique.

    PubMed

    Jachimczyk, Bartosz; Dziak, Damian; Kulesza, Wlodek J

    2016-06-14

    Real-time Locating Systems (RTLSs) have the ability to precisely locate the position of things and people in real time. They are needed for security and emergency applications, but also for healthcare and home care appliances. The research aims for developing an analytical method to customize RTLSs, in order to improve localization performance in terms of precision. The proposed method is based on Angle of Arrival (AoA), a ranging technique and fingerprinting method along with an analytically defined uncertainty of AoA, and a localization uncertainty map. The presented solution includes three main concerns: geometry of indoor space, RTLS arrangement, and a statistical approach to localization precision of a pair of location sensors using an AoA signal. An evaluation of the implementation of the customized RTLS validates the analytical model of the fingerprinting map. The results of simulations and physical experiments verify the proposed method. The research confirms that the analytically established fingerprint map is the valid representation of RTLS' performance in terms of precision. Furthermore, the research demonstrates an impact of workspace geometry and workspace layout onto the RTLS' performance. Moreover, the studies show how the size and shape of a workspace and the placement of the calibration point affect the fingerprint map. Withal, the performance investigation defines the most effective arrangement of location sensors and its influence on localization precision.

  13. PHOTOMETRIC EVOLUTION OF SNe Ib/c 2004ao, 2004gk, AND 2006gi

    SciTech Connect

    Elmhamdi, Abouazza; Kordi, Ayman; Tsvetkov, Dmitry; Danziger, I. John

    2011-04-20

    Photometric observations of three core collapse supernovae (SNe 2004ao, 2004gk, and 2006gi), covering about 200 days of evolution, are presented and analyzed. The photometric behavior of the three objects is consistent with their membership in the envelope-stripped Type Ib/c class. Pseudobolometric light curves are constructed. The corresponding measured e-folding times are found to be faster compared to the {sup 56}Co decay (i.e., 111.3 days), suggesting that a proportion of {gamma}-rays increasing with time have escaped without thermalization, owing to the low-mass nature of the ejecta. SN 2006gi has almost identical post-maximum decline phase luminosities as SN 1999ex and found to be similar to both SNe 1999dn and 1999ex in terms of the quasi-bolometric shape, placing it among the fast decliner Ib objects. SN 2004ao appears to fit within the slow decliner Ib SNe. SNe 2004ao and 2004gk display almost identical luminosities in the [50-100] day time interval, similar to SN 1993J. A preliminary simplified {gamma}-ray deposition model is described and applied to the computed pseudobolometric light curves, allowing one to find a range in the ejecta and {sup 56}Ni masses. The optical and quasi-bolometric light curves and the B - V color evolution of SN 2004gk are found to show a sudden drop after day 150. Correlating this fact to dust formation is premature and requires further observational evidence.

  14. L'univers clos de Stephen Hawking.

    NASA Astrophysics Data System (ADS)

    Andrillat, H.

    Einstein had curved space, Hawking will curve time. Hawking's universe is a closed model, a 4-sphere, which encloses its own space and its own time. Nothing exists outside and without any time overlapping this 4-sphere, it cannot have a beginning, an evolution or an end. It only is. But such an absolute existence of this type of universe implies that its 3-dimensional sclices - which are our physical space - cannot have the same absolute state of being. Thus, they are necessarily transitory, with a beginning and an end, in time which is the 4th remaining dimension of the 4-sphere. Hawking absolute universe is the cause of time.

  15. [Activities of Psychology Dept., California Univ.

    NASA Technical Reports Server (NTRS)

    Bridgeman, Bruce

    1998-01-01

    We have completed two studies during the grant period, with manuscripts published or ready for submission for publication: (1) Dual adaptation and adaptive generalization in the human vestibuloocular reflex and (2) Frequency vs. acceleration specificity in human VOR adaptation. In the 1st study two studies examined the possibility that rotational VOR plasticity is subject to dual adaptation and adaptive generalization. Subjects in the experimental condition were exposed to an altered visual-vestibular environment for about four minutes every day for five consecutive days. The working hours between these testing sessions constituted re-exposure to the normal visual environment. Thus, subjects were repeatedly adapting and re-adapting to both environments which is a condition designed to produce dual adaptation. In each training session a measure of baseline VOR gain was obtained (in the dark). A small laser spot (the only visual stimulus) was systematically moved in the same direction as the subject's head, but by half the angle of rotation (target/head gain = 0.5). This resulted in adaptation values relativized to the non-adapted gain of each subject. These values were then analyzed using an analysis of variance with day and session (within a day) as factors. In the 2nd study human VOR adaption has been assumed to be frequency specific, despite the fact that the semicircular canals are simulated by rotational acceleration and not frequency per se.

  16. Improving Laser-Guide Star AO Observations via Mesospheric Sodium Enhancement

    NASA Astrophysics Data System (ADS)

    Whiteley, R.; Yavorski, J.; Jelks, C.; Colburn, W.; Berner, K.

    The use of modern Adaptive Optics (AO) systems allows large telescopes to approach diffraction limited seeing. This technique can improve the imaging resolution of a large telescope by more than an order of magnitude. Such a capability provides real improvement in ground-based space situational awareness (SSA) observations. The drawback to current adaptive optics systems is that they only improve resolution over small imaging regions, sometimes as small as a few tens of arc seconds. Such small imaging regions limit the availability of suitable guide stars, which in turn limits the availability and duty cycle of an AO system. This limitation has led to the development of systems for producing artificial guide stars, which can be created along a line of sight coincident with that of the telescope. The most commonly used artificial guide stars are created by tuning a laser to the frequency of the Sodium D1/D2 line complex, and exciting sodium atoms in the Earth's mesosphere. The mesospheric sodium layer is exceptionally rarified, and has densities that vary diurnally, seasonally, and geographically. Our investigation centers on the use of sounding rockets to deliver substantial quantities of atomic sodium to the mesospheric layer. This direct enhancement of the sodium layer could increase the number of nights that laser-guide star AO observations could be performed, as well as increasing guide star brightness. These improvements should yield better AO wavefront correction and faster imaging frame rates. For the SSA application, these improvements will lead to more and better imaging opportunities. We will present a basic overview of the relevant mesospheric dynamics, with emphasis on sodium dwell times and replenishment rates. We will present several possible mechanisms for delivery and deployment of atomic sodium in the mesosphere, and demonstrate the trade-offs in their use. We will present a possible concept of operation for notional delivery systems. Finally, we

  17. Increasing Efficiency at the NTF by Optimizing Model AoA Positioning

    NASA Technical Reports Server (NTRS)

    Crawford, Bradley L.; Spells, Courtney

    2006-01-01

    The National Transonic Facility (NTF) at NASA Langley Research Center (LaRC) is a national resource for aeronautical research and development. The government, military and private industries rely on the capability of this facility for realistic flight data. Reducing the operation costs and keeping the NTF affordable is essential for aeronautics research. The NTF is undertaking an effort to reduce the time between data points during a pitch polar. This reduction is being driven by the operating costs of a cryogenic facility. If the time per data point can be reduced, a substantial cost savings can be realized from a reduction in liquid nitrogen (LN2) consumption. It is known that angle-of-attack (AoA) positioning is the longest lead-time item between points. In January 2005 a test was conducted at the NTF to determine the cause of the long lead-time so that an effort could be made to improve efficiency. The AoA signal at the NTF originates from onboard instrumentation then travels through a number of different systems including the signal conditioner, digital voltmeter, and the data system where the AoA angle is calculated. It is then fed into a closed loop control system that sets the model position. Each process along this path adds to the time per data point affecting the efficiency of the data taking process. Due to the nature of the closed loop feed back AoA control and the signal path, it takes approximately 18 seconds to take one pitch pause point with a typical AoA increment. Options are being investigated to reduce the time delay between points by modifying the signal path. These options include: reduced signal filtering, using analog channels instead of a digital volt meter (DVM), re-routing the signal directly to the AoA control computer and implementing new control algorithms. Each of these has potential to reduce the positioning time and together the savings could be significant. These timesaving efforts are essential but must be weighed against

  18. LDEF (Prelaunch), AO135 : Effect of Space Exposure on Pyroelectric Infrared Detectors, Tray E05

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), AO135 : Effect of Space Exposure on Pyroelectric Infrared Detectors, Tray E05 The prelaunch photograph was taken in SAEF II at KSC prior to installation of the integrated tray on the LDEF. The Space Exposure on Pyroelectric Infrared Detectors Experiment (AO135) consist of twenty detectors of three different types of materials, lithium-tantalate, strontium-barium-niobate and triglycine-sulfide. The Pyroelectric infrered detector experiment is an integral part of the Active Optical System Component Experiment (S0050) that contains 136 test specimen and is located in a six (6) inch deep LDEF peripheral experiment tray. The experiment tray is divided into six sections, each consisting of a 1/4 inch thick chromic anodized aluminum base plate and a 1/16th inch thick aluminum hat shaped structure for mounting the test specimen. The test specimen are typi- cally placed in fiberglass-epoxy retainer strip assemblies prior to installation on the hat shaped mounting structure. Five of the six sections are covered by a 1/8 inch thick anodized aluminum sun screen with openings that allowed 56 percent transmission over the central region. Two subexperiments, The Optical Materials and UV Detectors Experiment (S0050-01) consist of 15 optical windows, filters and detectors and occupies one of the trays six sub-sections and The Optical Substrates and Coatings Experiment (S0050-02 ) that includes 12 substrates and coatings and a secondary experiment, The Holographic Data Storage Crystal Experiment (AO044) with four crystals, are also mounted in the integrated tray. The experiment structure was assembled with non-magnetic stainless steel fasteners.

  19. An overview of the first results on the solar array passive LDEF experiment (sample), AO171

    NASA Technical Reports Server (NTRS)

    Whitaker, Ann F.; Young, Leighton E.

    1991-01-01

    Space environmental effects were visibly obvious on components of experiment AO171 which contained solar cells, composites, polymeric thin films, solar reflectors, protective coatings, metals, paints , and elastomers. Micrometeoroid/space debris impacts were observed on all experiment elements. Luminescence of polyimide, silicone, and polyurethane materials occurred under black light examination. Outgassing of RTV511 occurred mainly as a result of insufficient thermal vacuum bakeout. Solar cell degradation was predominantly below 10 percent. Elastomers lost mass and discolored; composites showed evidence of atomic oxygen attack, and unprotected thin polymer films eroded away.

  20. Preliminary results from the chemistry of micrometeoroid experiment (AO 187-1)

    NASA Technical Reports Server (NTRS)

    Horz, Friedrich; Bernhard, R. P.; See, Thomas H.; Warren, J.; Brownlee, Don E.; Laurance, M.

    1991-01-01

    The purpose of experiment AO 187-1 was to expose high purity substrates of suitable cratering properties to obtain detailed crater statistics that may be converted into projectile masses and fluxes and to chemically characterize as many impactors as possible. The latter information would hopefully reveal distinct classes of natural and man-made particles in low-Earth orbit. It was found that crater that yield residues show that natural and man-made impactors may be differentiated and that diversity exists within each group. 'Chondritic' compositions dominate among natural particles, yet some craters contain unmelted fragments of minerals (Olivine and pyroxene).

  1. Future use of silicon photomultipliers for K AOS at MAMI and P¯ANDA at FAIR

    NASA Astrophysics Data System (ADS)

    Achenbach, P.; Lorente, A. Sanchez; Majos, S. Sánchez; Pochodzalla, J.

    2009-10-01

    A characterization of scintillating fibres with silicon photomultiplier read-out was performed in view of their possible application in fibre tracking detector systems. Such a concept is being considered for the K AOS spectrometer at the Mainz Microtron MAMI and as a time-of-flight start detector for the hypernuclear physics programme at the P¯ANDA experiment of the FAIR project. Results on particle detection efficiency and time resolution are discussed. In summary, the silicon devices are very suitable for the detection of the low light yield from scintillating fibres insofar a trigger scheme is found to cope with the noise rate characteristics.

  2. The AIROPA software package: milestones for testing general relativity in the strong gravity regime with AO

    NASA Astrophysics Data System (ADS)

    Witzel, Gunther; Lu, Jessica R.; Ghez, Andrea M.; Martinez, Gregory D.; Fitzgerald, Michael P.; Britton, Matthew; Sitarski, Breann N.; Do, Tuan; Campbell, Randall D.; Service, Maxwell; Matthews, Keith; Morris, Mark R.; Becklin, E. E.; Wizinowich, Peter L.; Ragland, Sam; Doppmann, Greg; Neyman, Chris; Lyke, James; Kassis, Marc; Rizzi, Luca; Lilley, Scott; Rampy, Rachel

    2016-07-01

    General relativity can be tested in the strong gravity regime by monitoring stars orbiting the supermassive black hole at the Galactic Center with adaptive optics. However, the limiting source of uncertainty is the spatial PSF variability due to atmospheric anisoplanatism and instrumental aberrations. The Galactic Center Group at UCLA has completed a project developing algorithms to predict PSF variability for Keck AO images. We have created a new software package (AIROPA), based on modified versions of StarFinder and Arroyo, that takes atmospheric turbulence profiles, instrumental aberration maps, and images as inputs and delivers improved photometry and astrometry on crowded fields. This software package will be made publicly available soon.

  3. Tomographic separation of composite spectra - The components of the O-star spectroscopic binary AO Cassiopeiae

    NASA Technical Reports Server (NTRS)

    Bagnuolo, William G., Jr.; Gies, Douglas R.

    1991-01-01

    The UV photospheric lines of the short-period, double-lined O-star spectroscopic binary AO Cas are analyzed. Archival data from IUE (16 spectra uniformly distributed in orbital phase) were analyzed with a tomography algorithm to produce the separate spectra of the two stars in six spectral regions. The spectral classifications of the primary and secondary, O9.5 III and O8 V, respectively, were estimated through a comparison of UV line ratios with those in spectral standard stars. An intensity ratio of 0.5-0.7 (primary brighter) at 1600 A is compatible with the data.

  4. Monitoring Io volcanism with AO telescopes during and after the NH flyby

    NASA Astrophysics Data System (ADS)

    Marchis, F.; Spencer, J. R.; Lopes, R. M.; Davies, A. G.; Dumas, C.

    2007-12-01

    To support the New Horizons (NH) Jupiter encounter we monitored Io's volcanic activity using high angular resolution images in the near infrared (1-5 microns) provided by adaptive optics (AO) systems available on 8-10m class telescopes. We initiated the campaign on Feb. 25 2007 with data obtained with the VLT-Yepun telescope (ESO, Paranal, Chile), just before NH closest approach. We continued monitoring with the Gemini North telescope (Hawaii, USA). The last observation was taken on May 28 2007. Numerous active volcanoes are visible in the data but the Tvashtar eruption is by far the most energetic. Extremely high angular resolution data from NH revealed fine detail of the eruption, such as the presence of an active plume [1]. This volcano has an interesting past history. It was seen as a powerful eruption from Nov. 26 1999 during the Galileo I25 [2] flyby to Feb. 19 2001 from the ground [3]. It was dormant or below our ground-based limit of detection (T<330 K assuming an area of 460 km2) between Dec 2001 and May 2004 [4,5]. The re-awakening of the volcano was reported by Laver et al. [6] in April 2006 based on Keck Adaptive Optics (AO) observations. Our last Gemini AO observation taken on May 26 shows that Tvashtar was still very active. Based on the previous behavior of this volcano [7] it is very likely that the activity reported in 2007 is a continuation of the Tvashtar-2006 eruption. Other hot spots, such as Loki Patera, Pele, and a new hot spot located north of Loki Patera, were seen in our data. We will describe the global picture of Io's volcanic activity derived from our observations, comparing it with previous observations from the Galileo spacecraft and using ground-based AO. 1. Spencer et al., AGU, this session, 2007 2. McEwen et al., Science, 288, 1193-1198, 2000 3. Marchis et al. Icarus, 160, 124-131, 2002 4. Marchis et al., Icarus, 176, 1, 2005 5. Marchis et al., AGU Fall meeting, V33C-1483, 2004 6. Laver et al., Icarus, in press, 2006 7. Milazzo et

  5. The adaptive optics modes for HARMONI: from Classical to Laser Assisted Tomographic AO

    NASA Astrophysics Data System (ADS)

    Neichel, B.; Fusco, T.; Sauvage, J.-F.; Correia, C.; Dohlen, K.; El-Hadi, K.; Blanco, L.; Schwartz, N.; Clarke, F.; Thatte, N. A.; Tecza, M.; Paufique, J.; Vernet, J.; Le Louarn, M.; Hammersley, P.; Gach, J.-L.; Pascal, S.; Vola, P.; Petit, C.; Conan, J.-M.; Carlotti, A.; Vérinaud, C.; Schnetler, H.; Bryson, I.; Morris, T.; Myers, R.; Hugot, E.; Gallie, A. M.; Henry, David M.

    2016-07-01

    HARMONI is a visible and NIR integral field spectrograph, providing the E-ELT's core spectroscopic capability at first light. HARMONI will work at the diffraction limit of the E-ELT, thanks to a Classical and a Laser Tomographic AO system. In this paper, we present the system choices that have been made for these SCAO and LTAO modules. In particular, we describe the strategy developed for the different Wave-Front Sensors: pyramid for SCAO, the LGSWFS concept, the NGSWFS path, and the truth sensor capabilities. We present first potential implementations. And we asses the first system performance.

  6. LDEF (Prelaunch), AO187-01 : The Chemistry of Micrometeoroids, Tray A03

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 The prelaunch photograph shows the two (2) clam shell type canisters in their closed position. The canister shells are made of aluminum sheet material with end caps of diecast aluminum. The baseplate and support structure are fabricated from 6000 series aluminum. Fasteners are non-magnetic stainless steel. The electrical box and the stainless steel tubing located on the baseplate protect the drive system wiring. The experiment contains a timing mechanism that provides the intelligence to open the canisters after the Orbiter has departed the area and any initial outgassing or offgassing has occurred.

  7. Using DARC in a multi-object AO bench and in a dome seeing instrument

    NASA Astrophysics Data System (ADS)

    Sáez, Norman; Basden, Alistair; Guzmán, Dani; Dubost, Nicolás.; Berdja, Amokrane

    2014-07-01

    The Durham adaptive Optics Real Time Controller (DARC)1 is a real-time system for astronomical adaptive optics systems originally developed at Durham University and in use for the CANARY instrument. One of its main strengths is to be a generic and high performance real-time controller running on an off-the-shelf Linux computer. We are using DARC for two different implementations: BEAGLE,2 a Multi-Object AO (MOAO) bench system to experiment with novel tomographic reconstructors and LOTUCE2,3 an in-dome turbulence instrument. We present the software architecture for each application, current benchmarks and lessons learned for current and future DARC developers.

  8. COMPASS: an efficient, scalable and versatile numerical platform for the development of ELT AO systems

    NASA Astrophysics Data System (ADS)

    Gratadour, D.; Puech, M.; Vérinaud, C.; Kestener, P.; Gray, M.; Petit, C.; Brulé, J.; Clénet, Y.; Ferreira, F.; Gendron, E.; Lainé, M.; Sevin, A.; Rousset, G.; Hammer, F.; Jégouzo, I.; Paillous, Michele; Taburet, S.; Yang, Y.; Beuzit, J.-L.; Carlotti, A.; Westphal, M.; Epinat, B.; Ferrari, M.; Gautrais, T.; Lambert, J. C.; Neichel, B.; Rodionov, S.

    2014-08-01

    The main objective of the COMPASS project is to provide a full scale end-to-end AO development platform, able to address the E-ELT scale and designed as a free, open source numerical tool with a long term maintenance plan. The development of this platform is based on a full integration of software with hardware and relies on an optimized implementation on heterogeneous hardware using GPUs as accelerators. In this paper, we present the overall platform, the various work packages of this project, the milestones to be reached, the results already obtained and the first output of the ongoing collaborations.

  9. On random walk de Lévy aplicado aos mapas de variâncias

    NASA Astrophysics Data System (ADS)

    Klafke, J. C.

    2003-08-01

    Uma pergunta que surge ao nos confrontarmos com os mapas de variâncias, ou s-Maps [Klafke, J. C. "Estudo da Difusão Caótica em Ressonâncias Asteroidais", Tese de Doutorado, IAG/USP, 2002] diz respeito ao conteúdo físico de tais representações do espaço de fase. Ou seja, o que representa as variâncias das ações obtidas para uma determinada condição inicial e como relacioná-las com o tempo de difusão das órbitas, supondo-se que estas de fato estejam envolvidas em um processo difusivo? Para discutirmos essa questão, lançamos mão da modelagem dos processos estocásticos subjacentes às variâncias determinadas e implementamos uma série de simulações do tipo Monte Carlo a partir das informações registradas nos s-Maps calculados para algumas ressonâncias asteroidais bem estudadas (p.ex. 3: 1, 2: 1 e 3: 2). Para tanto, temos usado uma função de densidade de probabilidade gaussiana ao definir os n passos que permitirão estabelecer uma relação direta entre o Mapa de Difusão e o Mapa de Variâncias. Contudo, os resultados obtidos até agora tem subestimado o tempo de difusão esperado para os fenômenos conhecidos. Tal se deve ao fato de que, no processo difusivo real, é possível existirem passos de comprimento consideravelmente maiores que a média estabelecida pelas distribuições gaussiana ou normal, sobretudo quando se cruza uma região caótica. Neste trabalho, apresentamos os resultados comparativos de simulações de Monte Carlo com base no random walk de Lévy [Klafter, J. et al. 2002. "Beyond Brownian motion", Phys. Today, Feb, 33-39.], o qual possibilita passos esporádicos de comprimento acima do valor médio (saltos) permitindo estabelecer uma escala de tempo mais próxima da esperada para a difusão.

  10. Optical Photometry of the flaring gamma-ray blazar AO 0235+164

    NASA Astrophysics Data System (ADS)

    Pursimo, Tapio; Losada, Illa R.; Messa, Matteo; Gafton, Emanuel; Ojha, Roopesh

    2016-03-01

    We report optical photometry of the blazar AO 0235+164 obtained with the 2.56m Nordic Optical Telescope in La Palma to look for any enhanced optical activity associated with a recent flare in the daily averaged gamma-ray flux seen in the public lightcurve of the Fermi/LAT instrument: http://fermi.gsfc.nasa.gov/FTP/glast/data/lat/catalogs/asp/current/lightcurves/0235+164_86400.png Fermi/LAT first reported a detection of gamma-ray activity from this source in Sep, 2008 (ATel#1744) and a short timescale flare in Oct 14, 2008 (ATel#1784).

  11. LDEF (Prelaunch), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09

    NASA Technical Reports Server (NTRS)

    1983-01-01

    LDEF (Prelaunch), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 EL-1994-00302 LDEF (Prelaunch), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 The prelaunch photograph was taken in SAEF II at KSC prior to installation of the Cascade Variable Conductance Heat Pipe Experiment (CVCHPE) on the LDEF. The Cascade Variable Conductance Heat Pipe Experiment (CVCHPE) occupies a 6 inch deep LDEF peripheral experiment tray and consist of two series connected variable conductance heatpipes, a black chrome solar collector panel and a silvered TEFLON® radiator panel, a power source to support six thermistor-type temperature monitoring sensors and actuations of two valves. Fiberglass standoffs and internal insulation blankets thermally isolated the experiment from the experiment tray and the LDEF interior. The outside of the CVCHPE, except the collector and radiator panels, was covered with an aluminumized Kapton multilayer insulation (MLI) blanket with an outer layer of 0.076 mm thick Kapton. The two patches of thin film materials, part of Experiment S1001 by NASA GSFC, were attached to the cover of the external thermal blanket with Kapton tape. The experiment was assembled and mounted in the experiment tray with non-magnetic stainless steel fasteners.

  12. AO WFS detector developments at ESO to prepare for the E-ELT

    NASA Astrophysics Data System (ADS)

    Downing, Mark; Casali, Mark; Finger, Gert; Lewis, Steffan; Marchetti, Enrico; Mehrgan, Leander; Ramsay, Suzanne; Reyes, Javier

    2016-07-01

    ESO has a very active on-going AO WFS detector development program to not only meet the needs of the current crop of instruments for the VLT, but also has been actively involved in gathering requirements, planning, and developing detectors and controllers/cameras for the instruments in design and being proposed for the E-ELT. This paper provides an overall summary of the AO WFS Detector requirements of the E-ELT instruments currently in design and telescope focal units. This is followed by a description of the many interesting detector, controller, and camera developments underway at ESO to meet these needs; a) the rationale behind and plan to upgrade the 240x240 pixels, 2000fps, "zero noise", L3Vision CCD220 sensor based AONGC camera; b) status of the LGSD/NGSD High QE, 3e- RoN, fast 700fps, 1760x1680 pixels, Visible CMOS Imager and camera development; c) status of and development plans for the Selex SAPHIRA NIR eAPD and controller. Most of the instruments and detector/camera developments are described in more detail in other papers at this conference.

  13. Closed-loop focal plane wavefront control with the SCExAO instrument

    NASA Astrophysics Data System (ADS)

    Martinache, Frantz; Jovanovic, Nemanja; Guyon, Olivier

    2016-09-01

    Aims: This article describes the implementation of a focal plane based wavefront control loop on the high-contrast imaging instrument SCExAO (Subaru Coronagraphic Extreme Adaptive Optics). The sensor relies on the Fourier analysis of conventional focal-plane images acquired after an asymmetric mask is introduced in the pupil of the instrument. Methods: This absolute sensor is used here in a closed-loop to compensate for the non-common path errors that normally affects any imaging system relying on an upstream adaptive optics system.This specific implementation was used to control low-order modes corresponding to eight zernike modes (from focus to spherical). Results: This loop was successfully run on-sky at the Subaru Telescope and is used to offset the SCExAO deformable mirror shape used as a zero-point by the high-order wavefront sensor. The paper details the range of errors this wavefront-sensing approach can operate within and explores the impact of saturation of the data and how it can be bypassed, at a cost in performance. Conclusions: Beyond this application, because of its low hardware impact, the asymmetric pupil Fourier wavefront sensor (APF-WFS) can easily be ported in a wide variety of wavefront sensing contexts, for ground- as well space-borne telescopes, and for telescope pupils that can be continuous, segmented or even sparse. The technique is powerful because it measures the wavefront where it really matters, at the level of the science detector.

  14. LDEF (Postflight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 EL-1994-00266 LDEF (Postflight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 The experiment is shown in the postflight configuration before closing the canisters with ground support equipment that bypassed the experiments onboard electronics circuitry. Three full panels and approximately 3/4th of the other panel are covered with gold foil (>99.99 percent pure). The remaining area on the fourth panel is covered with strips of other detector materials: zirconium, beryllium, titanium, platium, aluminum, carbon, Kapton, polyethylene and TEFLON®. A brown stain is visible on the experiment tray flanges, however, most of the stains observed in the flight photograph are obscured by reflected light. All materials remain intact with no visual evidence of damage to the experiment. The reflection of a video camera on a tripod and light sources can be seen on the gold foil covered panels. The experiment canisters are shown after being closed by using the experiments ground support equipment. The stain buildup can be clearly seen at the vertical center of the right tray flange. The clean area was located under the experiment tray clamp block and was not exposed to the staining medium. The stain also coats other areas that were exposed during the mission but are not as noticeable. The experiment hardware seems to be intact and have no damage.

  15. LDEF (Flight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 EL-1994-00680 LDEF (Flight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 The flight photograph was taken with the LDEF on the Orbiter's RMS arm prior to berthing the spacecraft in the cargo bay. The canisters are in their open condition (they were expected to open about two (2) weeks after launch and close about eleven (11) months into the mission) with three (3) full panels and 3/4th of the fourth panel covered with a highly reflective gold foil (>99.99 percent pure).The remaining area is covered with strips of other detector materials: zirconium, beryllium, titanium, platium, aluminum, carbon, Kapton, polyethylene and TEFLON®. The exposed fasteners are non-magnetic stainless steel. All of the exposed materials seem to be secure and no damage is evident. The contamination stain that has changed the white paint dot on the tray clamp blocks to brown also coats the tray flanges and the aluminum canister hardware. The end support beam scuff plate in the photograph was a bright yellow prior to launch but is a much darker, mustard yellow after the space exposure.

  16. Instrument control software development process for the multi-star AO system ARGOS

    NASA Astrophysics Data System (ADS)

    Kulas, M.; Barl, L.; Borelli, J. L.; Gässler, W.; Rabien, S.

    2012-09-01

    The ARGOS project (Advanced Rayleigh guided Ground layer adaptive Optics System) will upgrade the Large Binocular Telescope (LBT) with an AO System consisting of six Rayleigh laser guide stars. This adaptive optics system integrates several control loops and many different components like lasers, calibration swing arms and slope computers that are dispersed throughout the telescope. The purpose of the instrument control software (ICS) is running this AO system and providing convenient client interfaces to the instruments and the control loops. The challenges for the ARGOS ICS are the development of a distributed and safety-critical software system with no defects in a short time, the creation of huge and complex software programs with a maintainable code base, the delivery of software components with the desired functionality and the support of geographically distributed project partners. To tackle these difficult tasks, the ARGOS software engineers reuse existing software like the novel middleware from LINC-NIRVANA, an instrument for the LBT, provide many tests at different functional levels like unit tests and regression tests, agree about code and architecture style and deliver software incrementally while closely collaborating with the project partners. Many ARGOS ICS components are already successfully in use in the laboratories for testing ARGOS control loops.

  17. Demonstration of the suitability of GPUs for AO real-time control at ELT scales

    NASA Astrophysics Data System (ADS)

    Bitenc, Urban; Basden, Alastair G.; Dipper, Nigel A.; Myers, Richard M.

    2016-07-01

    We have implemented the full AO data-processing pipeline on Graphics Processing Units (GPUs), within the framework of Durham AO Real-time Controller (DARC). The wavefront sensor images are copied from the CPU memory to the GPU memory. The GPU processes the data and the DM commands are copied back to the CPU. For a SCAO system of 80x80 subapertures, the rate achieved on a single GPU is about 700 frames per second (fps). This increases to 1100 fps (1565 fps) if we use two (four) GPUs. Jitter exhibits a distribution with the root-mean-square value of 20 μs-30 μs and a negligible number of outliers. The increase in latency due to the pixel data copying from the CPU to the GPU has been reduced to the minimum by copying the data in parallel to processing them. An alternative solution in which the data would be moved from the camera directly to the GPU, without CPU involvement, could be about 10%-20% faster. We have also implemented the correlation centroiding algorithm, which - when used - reduces the frame rate by about a factor of 2-3.

  18. Risk Factors Associated with Campylobacter jejuni Infections in Curaçao, Netherlands Antilles

    PubMed Central

    Endtz, Hubert P.; van West, Hanneke; Godschalk, Peggy C. R.; de Haan, Lidewij; Halabi, Yaskara; van den Braak, Nicole; Kesztyüs, Barbara I.; Leyde, Ewald; Ott, Alewijn; Verkooyen, Roel; Price, Lawrence J.; Woodward, David L.; Rodgers, Frank G.; Ang, C. Wim; van Koningsveld, Rinske; van Belkum, Alex; Gerstenbluth, Izzy

    2003-01-01

    A steady increase in the incidence of Guillain-Barré syndrome (GBS) with a seasonal preponderance, almost exclusively related to Campylobacter jejuni, and a rise in the incidence of laboratory-confirmed Campylobacter enteritis have been reported from Curaçao, Netherlands Antilles. We therefore investigated possible risk factors associated with diarrhea due to epidemic C. jejuni. Typing by pulsed-field gel electrophoresis identified four epidemic clones which accounted for almost 60% of the infections. One hundred six cases were included in a case-control study. Infections with epidemic clones were more frequently observed in specific districts in Willemstad, the capital of Curaçao. One of these clones caused infections during the rainy season only and was associated with the presence of a deep well around the house. Two out of three GBS-related C. jejuni isolates belonged to an epidemic clone. The observations presented point toward water as a possible source of Campylobacter infections. PMID:14662945

  19. Evaluating the Reliability and Reproducibility of the AO and Lauge-Hansen Classification Systems for Ankle Injuries.

    PubMed

    Yin, Meng-Chen; Yuan, Xue-Fei; Ma, Jun-Ming; Xia, Ye; Wang, Tao; Xu, Xiao-Li; Yan, Yin-Jie; Xu, Jin-Hai; Ye, Jie; Tong, Zheng-Yi; Feng, Yan-Qi; Wang, Hong-Bo; Wu, Xue-Qun; Mo, Wen

    2015-07-01

    Ankle injuries are responsible for more than 5 million emergency department visits each year. The AO and Lauge-Hansen classification systems are widely used in the clinical diagnosis of ankle injuries. This study aimed to analyze the intraobserver reliability and interobserver reproducibility of the AO and Lauge-Hansen classification systems. In addition, the authors explored the differences among physicians' classification responses and evaluated the clinical value for diagnosis. Fifty-six patients with an ankle injury with complete clinical and radiologic data were enrolled. The definition of injury type, the index score typing methods, and the specific study criteria were explained in detail. Five observers, who were orthopedic surgeons, determined the classifications according to both the AO and Lauge-Hansen systems. The classification was repeated 1 month later. Cronbach's alpha and Cohen's kappa test were used to determine interobserver reliability and intraobserver reproducibility. The physicians conducted 560 classifications (56 cases × 5 physicians × 2 times per patient). Average inter- and intraobserver kappa values for the AO system were 0.708 and 0.608, respectively. Average inter- and intraobserver kappa values for the Lauge-Hansen system were 0.402 and 0.398, respectively. Cronbach's alpha coefficient was 96.7% for the AO system and 76.0% for the Lauge-Hansen system. The Lauge-Hansen classification system is a comprehensive yet cumbersome system. Comparatively, the AO classification system is easier to understand. This study shows that the AO classification system has more reliability and reproducibility, and thus has more value in clinical practice, than the Lauge-Hansen classification system.

  20. The MeJA-inducible copper amine oxidase AtAO1 is expressed in xylem tissue and guard cells.

    PubMed

    Ghuge, Sandip A; Carucci, Andrea; Rodrigues-Pousada, Renato A; Tisi, Alessandra; Franchi, Stefano; Tavladoraki, Paraskevi; Angelini, Riccardo; Cona, Alessandra

    2015-01-01

    Copper amine oxidases oxidize the polyamine putrescine to 4-aminobutanal with the production of the plant signal molecule hydrogen peroxide (H2O2) and ammonia. The Arabidopsis (Arabidopsis thaliana) gene At4g14940 (AtAO1, previously referred to as ATAO1) encodes an apoplastic copper amine oxidase expressed in lateral root cap cells and developing xylem, especially in root protoxylem and metaxylem precursors. In our recent study, we demonstrated that AtAO1 expression is strongly induced in the root vascular tissues by the wound-signal hormone methyl jasmonate (MeJA). Furthermore, we also demonstrated that the H2O2 derived by the AtAO1-driven oxidation of putrescine, mediates the MeJA-induced early protoxylem differentiation in Arabidopsis roots. H2O2 may contribute to protoxylem differentiation by signaling developmental cell death and by acting as co-substrate in peroxidase-mediated cell wall stiffening and lignin polymerization. Here, by the means of AtAO1 promoter::green fluorescent protein-β-glucuronidase (AtAO1::GFP-GUS) fusion analysis, we show that a strong AtAO1 gene expression occurs also in guard cells of leaves and flowers. The high expression levels of AtAO1 in tissues or cell types regulating water supply and water loss may suggest a role of the encoded protein in water balance homeostasis, by modulating coordinated adjustments in anatomical and functional features of xylem tissue and guard cells during acclimation to adverse environmental conditions.

  1. The new Arecibo Observatory Remote Optical Facility (AO-ROF) in Culebra Island, Puerto Rico: Current Status and Future Projects

    NASA Astrophysics Data System (ADS)

    Santos, P. T.

    2015-12-01

    The idea of establishing the Arecibo Observatory Remote Optical Facility (AO-ROF) in the island of Culebra is a solution to mitigate the ever cumulative quantity of cloud, fog, and rain that has distressed observations at the Arecibo Observatory (AO) during major optical campaigns and observations. Given Culebra Island's favorable geographical and climatological characteristics as its low elevation and geographic location, it appears to have more steady weather conditions than Arecibo, so therefore it provides more availability for optical observations. Placed on Culebra, optical instruments can observe the same thermospheric volume over AO sampled by the Incoherent Scatter Radar (ISR). This capability will become especially important during the High Frequency (HF) facility is on operation. Small and large scale irregularities created by that HF can be readily observed and tracked from the Culebra site, and simultaneous observations from AO of the same atmospheric volume will permit direct vector measurements of dynamical evolution of the irregularities. This work presents a discussion of the current status of AO-ROF facility, as well the future projects.

  2. GOALS, STRATEGIES AND FIRST DISCOVERIES OF AO327, THE ARECIBO ALL-SKY 327 MHz DRIFT PULSAR SURVEY

    SciTech Connect

    Deneva, J. S.; Stovall, K.; Martinez, J. G.; Jenet, F.; McLaughlin, M. A.; Bates, S. D.; Bagchi, M.; Freire, P. C. C.

    2013-09-20

    We report initial results from AO327, a drift survey for pulsars with the Arecibo telescope at 327 MHz. The first phase of AO327 will cover the sky at declinations of –1° to 28°, excluding the region within 5° of the Galactic plane, where high scattering and dispersion make low-frequency surveys sub-optimal. We record data from a 57 MHz bandwidth with 1024 channels and 125 μs sampling time. The 60 s transit time through the AO327 beam means that the survey is sensitive to very tight relativistic binaries even with no acceleration searches. To date we have detected 44 known pulsars with periods ranging from 3 ms to 2.21 s and discovered 24 new pulsars. The new discoveries include 3 ms pulsars, three objects with periods of a few tens of milliseconds typical of young as well as mildly recycled pulsars, a nuller, and a rotating radio transient. Five of the new discoveries are in binary systems. The second phase of AO327 will cover the sky at declinations of 28°-38°. We compare the sensitivity and search volume of AO327 to the Green Bank North Celestial Cap survey and the GBT350 drift survey, both of which operate at 350 MHz.

  3. Eutrophication threatens Caribbean seagrasses - An example from Curaçao and Bonaire.

    PubMed

    Govers, Laura L; Lamers, Leon P M; Bouma, Tjeerd J; de Brouwer, Jan H F; van Katwijk, Marieke M

    2014-12-15

    Seagrass beds are globally declining due to human activities in coastal areas. We here aimed to identify threats from eutrophication to the valuable seagrass beds of Curaçao and Bonaire in the Caribbean, which function as nursery habitats for commercial fish species. We documented surface- and porewater nutrient concentrations, and seagrass nutrient concentrations in 6 bays varying in nutrient loads. Water measurements only provided a momentary snapshot, due to timing, tidal stage, etc., but Thalassia testudinum nutrient concentrations indicated long-term nutrient loads. Nutrient levels in most bays did not raise any concern, but high leaf % P values of Thalassia in Piscadera Bay (∼0.31%) and Spanish Water Bay (∼0.21%) showed that seagrasses may be threatened by eutrophication, due to emergency overflow of waste water and coastal housing. We thus showed that seagrasses may be threatened and measures should be taken to prevent loss of these important nursery areas due to eutrophication.

  4. LDEF (Postflight), AO139A : Growth of Crystals From Solutions in Low Gravity, Tray G06

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO139A : Growth of Crystals From Solutions in Low Gravity, Tray G06 The postflight photograph was taken in the SAEF II at KSC after the experiment tray was removed from the LDEF. The experiment tray flanges have become discolored with a light tan stain except where the tray clamp blocks were located. A darker stain appears to exist at the intersection of the white cover plate and the upper left flange of the experiment tray. The Crystal Growth experiment appears to have survived the extended mission with no visible damage. The experiment cover plate, originally white, appears to be discolored by a very light brown stain but is intact and securely in place.

  5. LDEF (Postflight), AO015 : Free-Flyer Biostack Experiment, Tray G02

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO015 : Free-Flyer Biostack Experiment, Tray G02 The post flight photograph was taken in the SAEF II at KSC after the experiment tray was removed from the LDEF. The experiment tray flanges and sidewalls have become discolored with a light tan stain except where the tray clamp blocks were located. The Biostack experiment appears to have survived the extended mission with no visible damage. The experiment housings are intact and all hardware is securely in place. The detector housings appear to be discolored with a stain similar to that on the tray hardware. The exposed Kapton H foil covering windows in two (2) detector housings do not appear to have sustained damage dur ing the extended mission. The perforated dome on two (2) of the detector housings has a slight tan discoloration but no indication of damage.

  6. Development and operation of an off-limb solar AO system

    NASA Astrophysics Data System (ADS)

    Taylor, Gregory Edward

    2014-01-01

    An Adaptive Optics system capable of locking-on to off-limb prominence structure has been proven successful. It has been shown to allow for diffraction limited spectroscopy and polarimetry of prominence structure. Spectroscopic data obtained using the Off-Limb AO system have been shown to contain a trove of information regarding the nature of solar prominences. In particular a Rayleigh-Taylor instability was seen in part of this data set. Such instabilities, and the rising plumes that result from them, are thought to be critical clues to the longterm persistence of quiescent solar prominences. This adaptive optics system will allow scientists to come one step closer to understanding the true nature of solar prominences.

  7. NIX, the imager for ERIS: the AO instrument for the VLT

    NASA Astrophysics Data System (ADS)

    Pearson, David; Taylor, William; Davies, Ric; MacIntosh, Mike; Henry, David; Lunney, David; Waring, Chris; Gao, Xiaofeng; Lightfoot, John; Glauser, Adrian M.; Quanz, Sascha P.; Meyer, Michael R.; Schmid, Hans Martin; March, Stephen; Bachmann, Walter; Feuchtgruber, Helmut; George, Elizabeth; Sturm, Eckhard; Biller, Beth; Hinckley, Sasha; Kenworthy, Matthew; Amico, Paola; Glindemann, Andreas; Kasper, Marcus; Kuntschner, Harald; Dorn, Reinhold; Egner, Sebastian

    2016-08-01

    ERIS will be the next-generation AO facility on the VLT, combining the heritage of NACO imaging, with the spectroscopic capabilities of an upgraded SINFONI. Here we report on the all-new NIX imager that will deliver diffraction-limited imaging from the J to M band. The instrument will be equipped with both Apodizing Phase Plates and Sparse Aperture Masks to provide high-angular resolution imagery, especially suited for exoplanet imaging and characterization. This paper provides detail on the instrument's design and how it is suited to address a broad range of science cases, from detailed studies of the galactic centre at the highest resolutions, to studying detailed resolved stellar populations.

  8. Toward a large lightweight mirror for AO: development of a 1m Ni coated CFRP mirror

    NASA Astrophysics Data System (ADS)

    Thompson, S. J.; Doel, A. P.; Brooks, D.; Strangwood, M.

    2008-07-01

    We present our recent developments towards the construction of a large, thin, single-piece mirror for adaptive optics (AO). Our current research program aims to have completed fabrication and testing of a 1m diameter, nickel coated carbon-fibre reinforced cyanate ester resin mirror by the last quarter of 2009. This composite mirror material is being developed to provide a lightweight and robust alternative to thin glass shell mirrors, with the challenge of future large deformable mirrors such as the 2.5m M4 on the E-ELT in mind. A detailed analysis of the material properties of test mirror samples is being performed at the University of Birmingham (UK), the first results of which are discussed and presented here. We discuss the project progress achieved so far, including fabrication of the 1m flat moulds for the replication process, manufacturing and testing methods for 20 cm diameter sample mirrors and system simulations.

  9. Interdecadal changes in the Asian winter monsoon variability and its relationship with ENSO and AO

    NASA Astrophysics Data System (ADS)

    Yun, Kyung-Sook; Seo, Ye-Won; Ha, Kyung-Ja; Lee, June-Yi; Kajikawa, Yoshiyuki

    2014-08-01

    Interdecadal changes in the Asian winter monsoon (AWM) variability are investigated using three surface air temperature datasets for the 55-year period of 1958-2012 from (1) the National Centers for Environmental Prediction-National Center for Atmospheric Research reanalysis 1 (NCEP), (2) combined datasets from the European Centre for Medium-range Weather Forecasts (ECMWF) 40-yr reanalysis and interim data (ERA), and (3) Japanese 55-year reanalysis (JRA). Particular attention has been paid to the first four empirical orthogonal function (EOF) modes of the AWM temperature variability that together account for 64% of the total variance and have been previously identified as predictable modes. The four modes are characterized as follows: the first mode by a southern warming over the Indo-western Pacific Ocean associated with a gradually increasing basin-wide warming trend; the second mode by northern warming with the interdecadal change after the late 1980s; the third and fourth modes by north-south triple pattern, which reveal a phase shift after the late 1970s. The three reanalyses agree well with each other when producing the first three modes, but show large discrepancy in capturing both spatial and temporal characteristics of the fourth mode. It is therefore considered that the first three leading modes are more reliable than the rest higher modes. Considerable interdecadal changes are found mainly in the first two modes. While the first mode shows gradually decreasing variance, the second mode exhibits larger interannual variance during the recent decade. In addition, after the late 1970s, the first mode has a weakening relationship with the El Niño-Southern Oscillation (ENSO) whereas the second mode has strengthening association with the Artic Oscillation (AO). This indicates an increasing role of AO but decreasing role of ENSO on the AWM variability. A better understanding of the interdecadal change in the dominant modes would contribute toward advancing in

  10. Robotic laser adaptive optics imaging of 715 Kepler exoplanet candidates using Robo-AO

    SciTech Connect

    Law, Nicholas M.; Ziegler, Carl; Morton, Tim; Riddle, Reed; Tendulkar, Shriharsh P.; Bui, Khanh; Dekany, Richard G.; Kulkarni, Shrinivas; Punnadi, Sujit; Baranec, Christoph; Ravichandran, Ganesh; Johnson, John Asher; Burse, Mahesh P.; Das, H. K.; Ramaprakash, A. N.

    2014-08-10

    The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star with laser adaptive optics imaging to search for blended nearby stars, which may be physically associated companions and/or responsible for transit false positives. In this paper, we present the results from the 2012 observing season, searching for stars close to 715 Kepler planet candidate hosts. We find 53 companions, 43 of which are new discoveries. We detail the Robo-AO survey data reduction methods including a method of using the large ensemble of target observations as mutual point-spread-function references, along with a new automated companion-detection algorithm designed for large adaptive optics surveys. Our survey is sensitive to objects from ≈0.''15 to 2.''5 separation, with magnitude differences up to Δm ≈ 6. We measure an overall nearby-star probability for Kepler planet candidates of 7.4% ± 1.0%, and calculate the effects of each detected nearby star on the Kepler-measured planetary radius. We discuss several Kepler Objects of Interest (KOIs) of particular interest, including KOI-191 and KOI-1151, which are both multi-planet systems with detected stellar companions whose unusual planetary system architecture might be best explained if they are 'coincident multiple' systems, with several transiting planets shared between the two stars. Finally, we find 98% confidence evidence that short-period giant planets are two to three times more likely than longer-period planets to be found in wide stellar binaries.

  11. Keck II laser guide star AO system and performance with the TOPTICA/MPBC laser

    NASA Astrophysics Data System (ADS)

    Chin, Jason C. Y.; Wizinowich, Peter; Wetherell, Ed; Lilley, Scott; Cetre, Sylvain; Ragland, Sam; Medeiros, Drew; Tsubota, Kevin; Doppmann, Greg; Otarola, Angel; Wei, Kai

    2016-07-01

    The Keck II Laser Guide Star (LGS) Adaptive Optics (AO) System was upgraded from a dye laser to a TOPTICA/MPBC Raman-Fibre Amplification (RFA) laser in December 2015. The W. M. Keck Observatory (WMKO) has been operating its AO system with a LGS for science since 2004 using a first generation 15 W dye laser. Using the latest diode pump laser technology, Raman amplification, and a well-tuned second harmonic generator (SHG), this Next Generation Laser (NGL) is able to produce a highly stable 589 nm laser beam with the required power, wavelength and mode quality. The beam's linear polarization and continuous wave format along with optical back pumping are designed to improve the sodium atom coupling efficiency over previously operated sodium-wavelength lasers. The efficiency and operability of the new laser has also been improved by reducing its required input power and cooling, size, and the manpower to operate and maintain it. The new laser has been implemented on the telescope's elevation ring with its electronics installed on a new Nasmyth sub-platform, with the capacity to support up to three laser systems for future upgrades. The laser is projected from behind the telescope's secondary mirror using the recently implemented center launch system (CLS) to reduce LGS spot size. We will present the new laser system and its performance with respect to power, stability, wavelength, spot size, optical repumping, polarization, efficiency, and its return with respect to pointing alignment to the magnetic field. Preliminary LGSAO performance is presented with the system returning to science operations. We will also provide an update on current and future upgrades at the WMKO.

  12. Robotic Laser Adaptive Optics Imaging of 715 Kepler Exoplanet Candidates Using Robo-AO

    NASA Astrophysics Data System (ADS)

    Law, Nicholas M.; Morton, Tim; Baranec, Christoph; Riddle, Reed; Ravichandran, Ganesh; Ziegler, Carl; Johnson, John Asher; Tendulkar, Shriharsh P.; Bui, Khanh; Burse, Mahesh P.; Das, H. K.; Dekany, Richard G.; Kulkarni, Shrinivas; Punnadi, Sujit; Ramaprakash, A. N.

    2014-08-01

    The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star with laser adaptive optics imaging to search for blended nearby stars, which may be physically associated companions and/or responsible for transit false positives. In this paper, we present the results from the 2012 observing season, searching for stars close to 715 Kepler planet candidate hosts. We find 53 companions, 43 of which are new discoveries. We detail the Robo-AO survey data reduction methods including a method of using the large ensemble of target observations as mutual point-spread-function references, along with a new automated companion-detection algorithm designed for large adaptive optics surveys. Our survey is sensitive to objects from ≈0.''15 to 2.''5 separation, with magnitude differences up to Δm ≈ 6. We measure an overall nearby-star probability for Kepler planet candidates of 7.4% ± 1.0%, and calculate the effects of each detected nearby star on the Kepler-measured planetary radius. We discuss several Kepler Objects of Interest (KOIs) of particular interest, including KOI-191 and KOI-1151, which are both multi-planet systems with detected stellar companions whose unusual planetary system architecture might be best explained if they are "coincident multiple" systems, with several transiting planets shared between the two stars. Finally, we find 98% confidence evidence that short-period giant planets are two to three times more likely than longer-period planets to be found in wide stellar binaries.

  13. Interannual variations of the blocking high over the Ural Mountains and its association with the AO/NAO in boreal winter

    NASA Astrophysics Data System (ADS)

    Li, Chao; Zhang, Qingyun; Ji, Liren; Peng, Jingbei

    2012-04-01

    This paper analyzes interannual variations of the blocking high over the Ural Mountains in the boreal winter and their association with the Arctic Oscillation/North Atlantic Oscillation (AO/NAO). In January, the relationship between the Ural blocking high (UR) and the AO index is statistically significant. The UR tends to occur more frequently and with greater strength during negative AO periods. Some strong URs also occur during positive AO phases (positive UR-AO events), as in January 2008. This paper discusses the characteristics of atmospheric circulation in the cases of positive UR-AO events and contrast cases (negative UR-AO events). The eastward extending of the Icelandic Low (IL) center and the associated NAO dipole anomaly pattern in the upstream region may play a more important role for the UR-AO events. When the center of the IL shifts eastward to 30°W, the amplitude of zonal wavenumber 2 (wavenumber 3) is intensified in the positive (negative) UR-AO events, which favors positive (negative) height anomalies over the Urals. Further analyses indicate that the intensified zonal wind in high latitudes and weakened zonal wind in midlatitudes over the North Atlantic Ocean render the eastward shift of the IL and the NAO dipole anomaly pattern. The Ural blocking in January 2008 bears similar characteristics to the positive UR-AO events.

  14. Winter AO/NAO modifies summer ocean heat content and monsoonal circulation over the western Indian Ocean

    NASA Astrophysics Data System (ADS)

    Gong, Dao-Yi; Guo, Dong; Li, Sang; Kim, Seong-Joong

    2017-02-01

    This paper analyzes the possible influence of boreal winter Arctic Oscillation/North Atlantic Oscillation (AO/ NAO) on the Indian Ocean upper ocean heat content in summer as well as the summer monsoonal circulation. The strong interannual co-variation between winter 1000-hPa geopotential height in the Northern Hemisphere and summer ocean heat content in the uppermost 120 m over the tropical Indian Ocean was investigated by a singular decomposition analysis for the period 1979-2014. The second paired-modes explain 23.8% of the squared covariance, and reveal an AO/NAO pattern over the North Atlantic and a warming upper ocean in the western tropical Indian Ocean. The positive upper ocean heat content enhances evaporation and convection, and results in an anomalous meridional circulation with ascending motion over 5°S-5°N and descending over 15°-25°N. Correspondingly, in the lower troposphere, significantly anomalous northerly winds appear over the western Indian Ocean north of the equator, implying a weaker summer monsoon circulation. The off-equator oceanic Rossby wave plays a key role in linking the AO/NAO and the summer heat content anomalies. In boreal winter, a positive AO/NAO triggers a down-welling Rossby wave in the central tropical Indian Ocean through the atmospheric teleconnection. As the Rossby wave arrives in the western Indian Ocean in summer, it results in anomalous upper ocean heating near the equator mainly through the meridional advection. The AO/NAO-forced Rossby wave and the resultant upper ocean warming are well reproduced by an ocean circulation model. The winter AO/NAO could be a potential season-lead driver of the summer atmospheric circulation over the northwestern Indian Ocean.

  15. Bioremediation of bisphenol-A polluted soil by Sphingomonas bisphenolicum AO1 and the microbial community existing in the soil.

    PubMed

    Matsumura, Yoshinobu; Akahira-Moriya, Ayako; Sasaki-Mori, Miho

    2015-01-01

    Bisphenol A (BPA, 2,2'-Bis (4-hydroxyphenyl) propane) is an artificial pollutant that is easily detected in soil and water environments. BPA decomposition and removal from the environment is relatively difficult due to its stability. This study evaluated the BPA decomposition and removal activities of the microbial community existing in the soil with or without Sphingomonas bisphenolicum AO1, and revealed the toxic effects of BPA towards the microbial community. The microbial community in soil was able to degrade BPA at 1.0 mg·g(-1) soil or lower, although its degradation was slow. On the other hand, BPA at more than 10 mg·g(-1) soil was not only degraded by the microbial community but also decreased its diversity, suggesting that BPA is harmful to many microorganisms. PCR-TTGE analysis and the cloned 16S rRNA gene sequence analysis indicated that Sphingomonadales, Xanthomonadales, Burkholderiales and Pseudomonadales in the microbial community might independently or cooperatively degrade BPA. On the other hand, supplementation with strain AO1 was able to significantly improve the BPA decomposition activity of the microbial community in soil even at 10 mg BPA·g(-1) soil, although BPA at 100 mg·g(-1) soil overwhelmed the BPA decomposition activity of strain AO1. Furthermore, it was also concluded that strain AO1 could not inhabit BPA purified soil after decomposition of BPA by strain AO1 and the soil microbial community, suggesting that the application of strain AO1 could be a low-burden method for the decomposition and removal of BPA from the natural environment.

  16. LDEF (Flight), AO171 : Solar-Array-Materials Passive LDEF Experiment, Tray A08

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO171 : Solar-Array-Materials Passive LDEF Experiment, Tray A08 EL-1994-00666 LDEF (Flight), AO171 : Solar-Array-Materials Passive LDEF Experiment, Tray A08 The flight photograph was taken from the Orbiter aft flight deck during the LDEF retrieval prior to berthing the LDEF in the Orbiter cargo bay and shows the Solar Array Materials Passive LDEF Experiment (SAMPLE) on the LDEF. Six (6) plates of passive components, provided by various experiment organizations and designated plate I thru plate VI, are shown mounted in a three (3) inch deep LDEF peripheral tray. All six plates are aluminum and attach to the LDEF experiment tray with non-magnetic stainless steel fasteners. Plate I, located in the upper left corner, consist of a combination of solar cells with and without covers, solar cell modules and solar arrays assembled on the baseplate. Two of the four solar arrays are missing and one appears to be attached at only one corner. Other components appear to be secure. Plate II in the left center section, has twenty-seven (27) composite samples, carbon fiber and glass fiber, mounted on the baseplate. The composites appear to be intact with no physical damage. Plate III, in the lower left corner, consist mostly of metallized and thin polymeric films (Kapton, Mylar, TEFLON® , white Tedlar,etc.). The thin films without protective coatings sustained significant damage and most were destroyed. The metallized film apparently survived with minimum damage. Plate IV located in the upper right corner consist of metals and coatings mounted in an aluminum baseplate and covered with a thin aluminum coverplate that partially mask the specimen. Several of the coatings appear to have changed to a darker color and a light brown discoloration appears around the outer edges of the mounting plate and along the right edge of the coverplates. Plate V, in the right center section, contained thermal plastics and structural film configured into tensile and shear specimen. All

  17. LDEF (Postflight), AO171 : Solar-Array-Materials Passive LDEF Experiment, Tray A08

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO171 : Solar-Array-Materials Passive LDEF Experiment, Tray A08 EL-1994-00147 LDEF (Postflight), AO171 : Solar-Array-Materials Passive LDEF Experiment, Tray A08 The post flight photograph was taken in the SAEF II at KSC prior to removal of the experiment tray from the LDEF and shows the Solar Array Materials Passive LDEF Experiment (SAMPLE) on the LDEF. Six (6) plates of passive components, provided by various experiment organizations and designated plate I thru plate VI, are shown mounted in a three (3) inch deep LDEF peripheral tray. All six plates are aluminum and attach to the LDEF experiment tray with non-magnetic stainless steel fasteners. Plate I, located in the upper right corner, consist of a combination of solar cells with and without covers, solar cell modules and solar arrays assembled on the baseplate. Three of the four solar arrays are missing. Other components appear to be secure. Plate II in the top center section, has twenty seven (27) composite samples, carbon fiber and glass fiber, mounted on the baseplate. The composites appear to be intact with no physical damage. Plate III, in the upper left corner, consist of metallized and thin polymeric films (Kapton, Mylar, TEFLON® , white Tedlar,etc.). The thin films without protective coatings sustained significant damage and most were destroyed. The thin film specimen hanging by one end in the flight photograph is missing. The metallized film apparently survived the mission with minimum damage. Plate IV located in the lower right corner consist of metals and coatings mounted in an aluminum baseplate and covered with a thin aluminum coverplate that partially mask the specimen. Several of the coatings appear to have darkened and a unique pattern of light brown discoloration appears around the outer edges of the mounting plate and along the lower edge of the coverplates. Plate V, in the lower center section, contained thermal plastics and structural film configured into tensile and

  18. Ionic Polymer-Coated Laccase with High Activity and Enhanced Stability: Application in the Decolourisation of Water Containing AO7

    PubMed Central

    Zhang, Xiaolin; Hua, Ming; Lv, Lu; Pan, Bingcai

    2015-01-01

    Eliminating dyes in environmental water purification remains a formidable challenge. Laccase is a unique, environmentally friendly and efficient biocatalyst that can degrade pollutants. However, the use of laccase for the degradation of pollutants is considerably limited by its susceptibility to environmental changes and its poor reusability. We fabricated a novel biocatalyst (LacPG) by coating polyethylenimine onto the native laccase (Lac) followed by crosslinking with glutaraldehyde. The stability of the resulting LacPG was highly enhanced against pH variations, thermal treatments and provided better long-term storage with a negligible loss in enzymatic activity. Compared to Lac, LacPG exhibited significantly higher decolourisation efficiency in the degradation of a representative azo dye, acid orange 7 (AO7), which resulted from the electrostatic attraction between the coating and AO7. LacPG was separated from the AO7 solution using an ultrafiltration unit. The increased size and modified surface chemistry of LacPG facilitated ultrafiltration and reduced membrane fouling. LacPG exhibited enhanced stability, high catalytic activity and favourable properties for membrane separation; therefore, LacPG could be continuously reused in an enzymatic membrane reactor with a high efficiency for decolourising water containing AO7. The developed strategy appears to be promising for enhancing the applicability of laccase in practical water treatment. PMID:25652843

  19. Project summary: Emerging technology assessment of phostrip, a/o, and bardenpho processes for biological phosphorus removal

    SciTech Connect

    1985-03-01

    This technology assessment addresses the process capabilities and limitations of three proprietary processes (PhoStrip, A/O, and Bardenpho) to biologically remove phosphorus from municipal wastewaters. The primary objective of this report is to provide guidance to individuals involved with reviewing new processes as part of the Innovative and Alternative Technology Program.

  20. The approbation of rejection method for positional observations of asteroids performed by SBG-telescope AO UFU

    NASA Astrophysics Data System (ADS)

    Galushina, T. Yu.; Skripnichenko, P. V.

    2013-12-01

    The main idea of this investigation has been connected with positional observations rejection method which founded on the analysis of results of the orbit elements improvement. This article contains approbation instances for positional observations per-formed by authors with help of SBG-telescope of AO UFU.

  1. Ionic Polymer-Coated Laccase with High Activity and Enhanced Stability: Application in the Decolourisation of Water Containing AO7

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaolin; Hua, Ming; Lv, Lu; Pan, Bingcai

    2015-02-01

    Eliminating dyes in environmental water purification remains a formidable challenge. Laccase is a unique, environmentally friendly and efficient biocatalyst that can degrade pollutants. However, the use of laccase for the degradation of pollutants is considerably limited by its susceptibility to environmental changes and its poor reusability. We fabricated a novel biocatalyst (LacPG) by coating polyethylenimine onto the native laccase (Lac) followed by crosslinking with glutaraldehyde. The stability of the resulting LacPG was highly enhanced against pH variations, thermal treatments and provided better long-term storage with a negligible loss in enzymatic activity. Compared to Lac, LacPG exhibited significantly higher decolourisation efficiency in the degradation of a representative azo dye, acid orange 7 (AO7), which resulted from the electrostatic attraction between the coating and AO7. LacPG was separated from the AO7 solution using an ultrafiltration unit. The increased size and modified surface chemistry of LacPG facilitated ultrafiltration and reduced membrane fouling. LacPG exhibited enhanced stability, high catalytic activity and favourable properties for membrane separation; therefore, LacPG could be continuously reused in an enzymatic membrane reactor with a high efficiency for decolourising water containing AO7. The developed strategy appears to be promising for enhancing the applicability of laccase in practical water treatment.

  2. CHOUGH: implementation and performance of a high-order 4m AO demonstrator

    NASA Astrophysics Data System (ADS)

    Bharmal, Nazim A.; Basden, Alastair G.; Bourgenot, Cyril J.; Black, Martin; Dubbeldam, Cornelis M.; Henry, David M.; Hölck-Santibanez, Daniel; Morris, Timothy J.; Robertson, David J.; Schmoll, Jürgen; Talbot, Robert G.; Younger, Eddy J.; Myers, Richard M.

    2016-07-01

    CHOUGH is a small, fast project to provide an experimental on-sky high-order SCAO capability to the 4.2m WHT telescope. The basic goal has r0-sized sub- apertures with the aim of achieving high-Strehl ratios (> 0:5) in the visible (> 650 nm). It achieves this by including itself into the CANARY experiment: CHOUGH is mounted as a breadboard and intercepts the beam within CANARY via a periscope. In doing so, it takes advantage of the mature CANARY infrastructure, but add new AO capabilities. The key instruments that CHOUGH brings to CANARY are: an atmospheric dispersion compensator; a 32 × 32 (1000 actuator) MEMS deformable mirror; 31 × 31 wavefront sensor; and a complementary (narrow-field) imager. CANARY provides a 241-actuator DM, tip/tilt mirror, and comprehensive off-sky alignment facility together with a RTC. In this work, we describe the CHOUGH sub-systems: backbone, ADC, MEMS-DM, HOWFS, CAWS, and NFSI.

  3. Characterization, Expression Profile, and Promoter Analysis of the Rhodeus uyekii Vitellogenin Ao1 Gene

    PubMed Central

    Kong, Hee Jeong; Kim, Ju Lan; Moon, Ji Young; Kim, Woo-Jin; Kim, Hyung Soo; Park, Jung Youn; Cho, Hyun Kook; An, Cheul Min

    2014-01-01

    The fish Vitellogenin (Vg) gene has been applied as a biomarker for exposure to estrogenic compounds in the aquatic environment. In this study, we cloned and characterized Vg cDNA from the Korean rose bitterling Rhodeus uyekii (Ru-Vg). The Ru-Vg cDNA encodes a 1424-amino-acid polypeptide that belongs to the VgAo1 family and contains a putative signal peptide, lipovitellin I, phosvitin, and lipovitellin II, but does not contain the vWFD domain or the C-terminal peptide. The deduced Ru-Vg protein has high amino acid identity (73.97%–32.17%) with fish Vg proteins. Pairwise alignment and phylogenetic analysis revealed that Ru-Vg is most closely related to Acheilognathus yamatsutae Vg. Ru-Vg transcripts were detected using quantitative polymerase chain reaction in all tissues tested, with the highest level of expression observed in the ovary. Ru-Vg mRNA was upregulated in R. uyekii hepatopancreas cells in response to treatment with 17β-estradiol (E2) or 17α-ethinylestradiol (EE2). Luciferase reporter expression, driven by the 5'-regulatory region of the Ru-Vg gene spanning from −1020 bp to the start codon was induced by the estrogen receptor and was synergistically activated by treatment with E2 or EE2. These results suggest that R. uyekii and the Ru-Vg gene may be useful as biomarkers for exposure to E2 or EE2. PMID:25329620

  4. Laser testing of an Iris AO dielectric-coated segmented MEMS DM

    NASA Astrophysics Data System (ADS)

    Helmbrecht, Michael A.; He, Min; Norton, Andrew P.; Gavel, Donald T.

    2011-09-01

    Iris AO has been developing dielectric-coated segmented MEMS deformable mirrors (DM) for use in laser applications that range from 355-1540 nm. In order to mitigate deformation from residual stress in the thick dielectric coatings, a stress-compensation layer has been added to the underside if the DM segments. This paper describes fabrication results of DMs with high reflectance dielectric coatings for 532 nm, 1064 nm, and 1540 nm. Additionally, a DM with a 532 nm coating has been tested with a 2 W, 532 nm CW laser. Laser testing shows the DM can handle 300 W/cm2 with off-theshelf packaging. Projections show that with good heat sinking, the same DM can handle laser power densities of 2800 W/cm2. The coatings showed no signs of damage after exposure to a w0=25 μm beam with a power density of 205 kW/cm2 for 105 minutes at the center of a segment and at segment edges exposed to 180 kW/cm2 for 45 minutes.

  5. High-power visible-laser effect on a 37-segment Iris AO deformable mirror

    NASA Astrophysics Data System (ADS)

    Norton, Andrew; Gavel, Donald; Dillon, Daren

    2010-02-01

    We have tested an aluminum-coated Iris AO Micro-Electrical Mechanical System (MEMS) segmented Deformable Mirror (DM) for its behavior in the presence of high energy 532 nm laser light. The DM was subject to several tests in which the laser power and the duration of its incidence was varied. The DM experienced an irradiance of 94.5 W cm-2 at the maximum laser power of 2 W. A slight permanent reduction in the amount of bow in each segment was observed. This is most likely due to annealing. The mirror remained fully functional during and after the tests. Measurements of the mirror's temporal stability and position repeatability were performed before the laser test. We found a 1.28 nm rms variation in the bow of segments that is highly correlated over the 16 minute test. The mirror's ability to return to its initial position was within the 1.34 nm rms instrument noise. These results are encouraging for applications such as the laser uplink correction of the Visible Light Laser Guidestar Experiment (Villages) and future multi-Laser Guidestar systems (LGS).

  6. Ultraviolet spectral behavior of AO Psc and V1223 Sgr from the HST and IUE satellites

    NASA Astrophysics Data System (ADS)

    Sanad, M. R.

    2015-03-01

    We present a spectroscopic study of two intermediate polar systems, AO Psc and V1223 Sgr observed with the Hubble Space Telescope Space Telescope Imaging Spectrograph (HST STIS) and International Ultraviolet Explorer (IUE) during the period 1980-2000. The reddening of two systems is determined from the 2200 Å feature. The ultraviolet emission lines are originating in the accretion disk as a result of existing an extra component of emission in the EUV/soft X-ray range with luminosity comparable to the accretion luminosity which reprocessed to produce the observed ultraviolet line strengths. Different spectra for both systems showing the variations in line fluxes at different orbital phases are presented. We concentrated on calculating the line fluxes of C IV 1550 Å & He II 1640 Å emission lines. From HST and IUE data, we derived an accretion luminosities and an accretion rates for two systems. Our results show that there are variations in line fluxes, accretion luminosities and accretion rates with time for two systems. These variations are attributed to the variations of both density and temperature as a result of a changing rate of mass transfer from the secondary star to the white dwarf. These results from the IUE and HST observations are consistent with the models of Ko et al. (Astrophys. J., 457:363K, 1996).

  7. Long-term stability and temperature variability of Iris AO segmented MEMS deformable mirrors

    NASA Astrophysics Data System (ADS)

    Helmbrecht, M. A.; He, M.; Kempf, C. J.; Marchis, F.

    2016-07-01

    Long-term stability of deformable mirrors (DM) is a critical performance requirement for instruments requiring open-loop corrections. The effects of temperature changes in the DM performance are equally critical for such instruments. This paper investigates the long-term stability of three different Iris AO PTT111 DMs that were calibrated at different times ranging from 13 months to nearly 29 months prior to subsequent testing. Performance testing showed that only a small increase in positioning errors occurred from the initial calibration date to the test dates. The increases in errors ranged from as little as 1.38 nm rms after 18 months to 5.68 nm rms after 29 months. The paper also studies the effects of small temperature changes, up to 6.2°C around room temperature. For three different arrays, the errors ranged from 0.62-1.42 nm rms/°C. Removing the effects of packaging shows that errors are <=0.50 nm rms/°C. Finally, measured data showed that individual segments deformed <=0.11 nm rms/°C when heated.

  8. Lifestyle in Curaçao. Smoking, alcohol consumption, eating habits and exercise.

    PubMed

    Grol, M E; Halabi, Y T; Gerstenbluth, I; Alberts, J F; O'Niel, J

    1997-03-01

    The Curaçao Health Study was carried out among a randomized sample (n = 2248, response rate = 85%) of the adult non-institutionalized population in order to assess aspects of lifestyle that may pose health risks. Factors examined were tobacco and alcohol use, eating habits and exercise behaviour. Outcome variables were cross-tabulated by gender, age and socioeconomic status. 17.1% of the participants were smokers and 20.5% were regular drinkers, including 6.3% of the men who consumed alcohol excessively (4 or more glasses of alcohol a day). 75% of the participants did not exercise regularly, 37% did not eat vegetables daily, and half did not eat fruit daily. Other poor eating habits were the addition of extra sugar and salt to prepared food by 33% and 20% of the participants, respectively. On the whole, men had less healthy lifestyles than women, with the exception of exercise behaviour. People of high socioeconomic status (SES) drank less alcohol, and exercised more often than those of low SES. Considering the high prevalence of diabetes mellitus and hypertension in the Caribbean, research on lifestyle factors in other Caribbean countries is required to facilitate the development of regional prevention and intervention programmes.

  9. Laser pointing camera: a valuable tool for the LGS-AO operations

    NASA Astrophysics Data System (ADS)

    Centrone, M.; Bonaccini Calia, D.; Pedichini, F.; Cerruto, A.; Ricciardi, A.; Ambrosino, F.

    2016-07-01

    We describe the design, functionalities and commissioning results of the Laser Pointing Camera, developed at INAF-OAR in collaboration with ESO and Astrel for the 4LGSF of the ESO Adaptive Optics Facility. The LPC has proven a fundamental tool during commissioning and operation of the 4LGSF. It allows to calibrate the pointing and focusing models of the four LGS, to reduce to zero the overhead time for the open-loop acquisition of the LGS in the wavefront sensor. During LGS-AO operation it collects regularly the LGS photometry, the LGS fwhm and the cirrus clouds scattering levels. By recognizing via astrometric software the field stars as well as the multiple LGS, LPC is insensitive to flexures of the laser launch telescope or of the receiver telescope opto-mechanics. We present the Commissioning results of the Laser Pointing Camera, obtained at the ESO VLT during the all 4LGSF Laser Guide Star Units Commissioning, and will discuss its possible extension for the ELT operations.

  10. Variability and Period Analysis for BL Lac AO 0235+164

    NASA Astrophysics Data System (ADS)

    Fan, J. H.; Kurtanidze, O.; Liu, Y.; Liu, X.; Yang, J. H.; Richter, G. M.; Nikolashvili, M. G.; Kurtanidze, S. O.; Wang, H. T.; Sasada, M.; Zhou, A. Y.; Lin, C.; Yuan, Y. H.; Zhang, Y. T.; Costantin, D.

    2017-03-01

    Variability is one of the extreme observational properties of BL Lacertae objects. AO 0235+164 is a well-studied BL Lac throughout all electromagnetic wavebands. In the present work, we show its optical R-band photometric observations carried out during the period from 2006 November to 2012 December using the Ap6E CCD camera attached to the primary focus of the 70 cm meniscus telescope at Abastumani Observatory, Georgia. During our monitoring period, it showed a large variation of {{Δ }}R=4.88 {mag} (14.19–19.07 mag) and a short timescale of {{Δ }}{T}v=73.5 {minutes}. During the period of 2006 December to 2009 November, we made radio observations of the source using the 25 m radio telescope at Xinjiang Astronomical Observatory. By adopting a discrete correlation function to the optical and radio observations we found that the optical variation leads a radio variation of 23.2 ± 12.9 days.

  11. The Robo-AO KOI Survey: Laser Adaptive Optics Imaging of Every Kepler Exoplanet Candidate

    NASA Astrophysics Data System (ADS)

    Ziegler, Carl; Law, Nicholas M.; Baranec, Christoph; Morton, Tim; Riddle, Reed L.

    2016-01-01

    The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star (KOI) with laser adaptive optics imaging to hunt for blended nearby stars which may be physically associated companions. With the unparalleled efficiency provided by the first fully robotic adaptive optics system, we perform the critical search for nearby stars (0.15" to 4.0" separation with contrasts up to 6 magnitudes) that pollute the observed planetary transit signal, contributing to inaccurate planetary characteristics or astrophysical false positives. We present approximately 3300 high resolution observations of Kepler planetary hosts from 2012-2015, with ~500 observed nearby stars. We measure an overall nearby star probability rate of 16.2±0.8%. With this large dataset, we are uniquely able to explore broad correlations between multiple star systems and the properties of the planets which they host. We then use these clues for insight into the formation and evolution of these exotic systems. Several KOIs of particular interest will be discussed, including possible quadruple star systems hosting planets and updated properties for possible rocky planets orbiting in the habitable zone.

  12. The Robo-AO KOI survey: laser adaptive optics imaging of every Kepler exoplanet candidate

    NASA Astrophysics Data System (ADS)

    Ziegler, Carl; Law, Nicholas M.; Baranec, Christoph; Morton, Tim; Riddle, Reed; Atkinson, Dani; Nofi, Larissa

    2016-07-01

    The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star (KOI) with laser adaptive optics imaging to hunt for blended nearby stars which may be physically associated companions. With the unparalleled efficiency provided by the first fully robotic adaptive optics system, we perform the critical search for nearby stars (0.15" to 4.0" separation with contrasts up to 6 magnitudes) that dilute the observed planetary transit signal, contributing to inaccurate planetary characteristics or astrophysical false positives. We present 3313 high resolution observations of Kepler planetary hosts from 2012-2015, discovering 479 nearby stars. We measure an overall nearby star probability rate of 14.5+/-0.8%. With this large data set, we are uniquely able to explore broad correlations between multiple star systems and the properties of the planets which they host, providing insight into the formation and evolution of planetary systems in our galaxy. Several KOIs of particular interest will be discussed, including possible quadruple star systems hosting planets and updated properties for possible rocky planets orbiting with in their star's habitable zone.

  13. Subaru/SCExAO First-light Direct Imaging of a Young Debris Disk around HD 36546

    NASA Astrophysics Data System (ADS)

    Currie, Thayne; Guyon, Olivier; Tamura, Motohide; Kudo, Tomoyuki; Jovanovic, Nemanja; Lozi, Julien; Schlieder, Joshua E.; Brandt, Timothy D.; Kuhn, Jonas; Serabyn, Eugene; Janson, Markus; Carson, Joseph; Groff, Tyler; Kasdin, N. Jeremy; McElwain, Michael W.; Singh, Garima; Uyama, Taichi; Kuzuhara, Masayuki; Akiyama, Eiji; Grady, Carol; Hayashi, Saeko; Knapp, Gillian; Kwon, Jung-mi; Oh, Daehyeon; Wisniewski, John; Sitko, Michael; Yang, Yi

    2017-02-01

    We present H-band scattered light imaging of a bright debris disk around the A0 star HD 36546 obtained from the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system with data recorded by the HiCIAO camera using the vector vortex coronagraph. SCExAO traces the disk from r ∼ 0.″3 to r ∼ 1″ (34–114 au). The disk is oriented in a near east–west direction (PA ∼ 75°), is inclined by i ∼ 70°–75°, and is strongly forward-scattering (g > 0.5). It is an extended disk rather than a sharp ring; a second, diffuse dust population extends from the disk’s eastern side. While HD 36546 intrinsic properties are consistent with a wide age range (t ∼ 1–250 Myr), its kinematics and analysis of coeval stars suggest a young age (3–10 Myr) and a possible connection to Taurus-Auriga’s star formation history. SCExAO’s planet-to-star contrast ratios are comparable to the first-light Gemini Planet Imager contrasts; for an age of 10 Myr, we rule out planets with masses comparable to HR 8799 b beyond a projected separation of 23 au. A massive icy planetesimal disk or an unseen super-Jovian planet at r > 20 au may explain the disk’s visibility. The HD 36546 debris disk may be the youngest debris disk yet imaged, is the first newly identified object from the now-operational SCExAO extreme AO system, is ideally suited for spectroscopic follow-up with SCExAO/CHARIS in 2017, and may be a key probe of icy planet formation and planet–disk interactions.

  14. Revolutionary visible and infrared sensor detectors for the most advanced astronomical AO systems

    NASA Astrophysics Data System (ADS)

    Feautrier, Philippe; Gach, Jean-Luc; Guieu, Sylvain; Downing, Mark; Jorden, Paul; Rothman, Johan; de Borniol, Eric D.; Balard, Philippe; Stadler, Eric; Guillaume, Christian; Boutolleau, David; Coussement, Jérome; Kolb, Johann; Hubin, Norbert; Derelle, Sophie; Robert, Clélia; Tanchon, Julien; Trollier, Thierry; Ravex, Alain; Zins, Gérard; Kern, Pierre; Moulin, Thibaut; Rochat, Sylvain; Delpoulbé, Alain; Lebouqun, Jean-Baptiste

    2014-07-01

    We report in this paper decisive advance on the detector development for the astronomical applications that require very fast operation. Since the CCD220 and OCAM2 major success, new detector developments started in Europe either for visible and IR wavelengths. Funded by ESO and the FP7 Opticon European network, the NGSD CMOS device is fully dedicated to Natural and Laser Guide Star AO for the E-ELT with strong ESO involvement. The NGSD will be a 880x840 pixels CMOS detector with a readout noise of 3 e (goal 1e) at 700 Hz frame rate and providing digital outputs. A camera development, based on this CMOS device and also funded by the Opticon European network, is ongoing. Another major AO wavefront sensing detector development concerns IR detectors based on Avalanche Photodiode (e- APD) arrays within the RAPID project. Developed by the SOFRADIR and CEA/LETI manufacturers, the latter offers a 320x255 8 outputs 30 microns IR array, sensitive from 0.4 to 3 microns, with less than 2 e readout noise at 1600 fps. A rectangular window can also be programmed to speed up even more the frame rate when the full frame readout is not required. The high QE response, in the range of 70%, is almost flat over this wavelength range. Advanced packaging with miniature cryostat using pulse tube cryocoolers was developed in the frame of this programme in order to allow use on this detector in any type of environment. The characterization results of this device are presented here. Readout noise as low as 1.7 e at 1600 fps has been measured with a 3 microns wavelength cut-off chip and a multiplication gain of 14 obtained with a limited photodiode polarization of 8V. This device also exhibits excellent linearity, lower than 1%. The pulse tube cooling allows smart and easy cooling down to 55 K. Vibrations investigations using centroiding and FFT measurements were performed proving that the miniature pulse tube does not induce measurable vibrations to the optical bench, allowing use of this

  15. LDEF (Flight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 EL-1994-00020 LDEF (Flight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 The flight photograph of the Cascade Variable Conductance Heat Pipe Experiment (CVCHPE) was taken while the LDEF was attached to the Orbiter's RMS arm prior to berthing in the Orbiter's cargo bay. The white paint dots on the center clamp blocks of the experiment trays right flange and lower flange appear to be slightly discolored. The LDEF structure, top intercostal, has a dark brown discoloration adjacent to the black thermal panel. Aluminum particles from the degraded CVCHPE thermal blanket are also visible in this area. The Cascade Variable Conductance Heat Pipe Experiment (CVCHPE) occupies a 6 inch deep LDEF peripheral experiment tray and consist of two series connected variable conductance heatpipes, a black chrome solar collector panel and a silvered TEFLON® radiator panel, a power source to support six thermistor-type temperature monitoring sensors and actuations of two valves. Fiberglass standoffs and internal insulation blankets thermally isolated the experiment from the experiment tray and the LDEF interior. The outside of the CVCHPE, except the collector and radiator panels, was covered with an aluminumized Kapton multilayer insulation (MLI) blanket with an outer layer of 0.076 mm thick Kapton. The two patches of thin film materials, part of an atomic oxygen experiment (see S1001) by NASA GSFC, were attached to the cover of the external thermal blanket with Kapton tape. The experiment was assembled and mounted in the experiment tray with non-magnetic stainless steel fasteners. The external CVCHPE materials have changed significantly. The Kapton on the thermal blanket aluminized Kapton cover appears to be completely eroded, except under Kel-F buttons used to secure the blanket, leaving only the very thin vapor deposited aluminum coating as a cover. Parts of the aluminum coating residue has moved to

  16. LDEF (Postflight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 EL-1994-00354 LDEF (Postflight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 The postflight photograph was taken in the SAEF II at KSC prior to removal of the experiment from the LDEF. The color of the white paint dots on the exper- iment tray clamp blocks appear to be unchanged. The LDEF structure, the intercostal on the right, has a dark brown discoloration adjacent to the black Earth end thermal panel. Aluminum pieces of the degraded CVCHPE thermal cover that were shown lodged in the vent area between the intercostal and the black thermal panel in the flight photograph are gone. The Cascade Variable Conductance Heat Pipe Experiment (CVCHPE) occupies a 6 inch deep LDEF peripheral experiment tray and consist of two series connected variable conductance heatpipes, a black chrome solar collector panel and a silvered TEFLON® radiator panel, a power source to support six thermistor-type temperature monitoring sensors and actuations of two valves. Fiberglass standoffs and internal insulation blankets thermally isolated the experiment from the experiment tray and the LDEF interior. The outside of the CVCHPE, except the collector and radiator panels, was covered with an aluminized Kapton multilayer insulation (MLI) blanket with an outer layer of 0.076 mm thick Kapton. The two patches of thin film materials, part of Experiment S1001 by NASA GSFC, were attached to the cover of the external thermal blanket with Kapton tape. The experiment was assembled and mounted in the experiment tray with non-magnetic stainless steel fasteners. The external surface of the CVCHPE has changed from that observed in the flight photograph. The thin vapor deposited aluminum coating, left after the Kapton eroded, is essentially gone with only fragments left near the edges of the thermal blanket. Pieces of a layer of Dacron mesh (bridle vail) material, used to separate the thermal cover from the thermal

  17. Deriving the True Mass of an Unresolved Brown Dwarf Companion with AO Aided Astrometry

    NASA Astrophysics Data System (ADS)

    Meyer, Eva; Kürster, M.

    2010-01-01

    From radial velocity detections alone one does not get all orbital parameters needed to derive the true mass of a non-transiting, unresolved substellar companion to a star. Additional astrometric measurements are needed to calculate the inclination and the longitude of the ascending node. Until today only few true companion masses have been determined by this method with the HST fine guidance sensor (Benedict 2006, Benedict 2002). We aim to derive the true mass of a brown dwarf candidate companion to an early M 2.5V dwarf with groundbased high-resolution astrometry aided by adaptive optics. We found this unique brown dwarf desert object, which distance to the host star is only 0.42 AU, in our UVES precision radial velocity survey of M dwarfs, inferring a minimum companion mass of 27 Jupiter masses (Kuerster 2008). Combining the data with HIPPARCOS astrometry, we found a probability of only 2.9% that the companion is stellar. We are therefore observing the host star and a reference star within a monitoring program with VLT/NACO to derive the true mass of the companion and establish its nature (BD vs. star). Simultaneous observations of a reference field in a globular cluster are performed to determine the stability of the AO plus detector system and check its suitability for such high-precision astrometric measurements over several epochs which are needed to find and analyse extrasolar planet systems. We present preliminary results of the analysis of the astrometric displacements of the host star due to the unseen companion after correcting for differential refraction and differential aberration, as well as a first orbit fit and mass estimation.

  18. Climate Factors as Important Determinants of Dengue Incidence in Curaçao.

    PubMed

    Limper, M; Thai, K T D; Gerstenbluth, I; Osterhaus, A D M E; Duits, A J; van Gorp, E C M

    2016-03-01

    Macro- and microclimates may have variable impact on dengue incidence in different settings. We estimated the short-term impact and delayed effects of climate variables on dengue morbidity in Curaçao. Monthly dengue incidence data from 1999 to 2009 were included to estimate the short-term influences of climate variables by employing wavelet analysis, generalized additive models (GAM) and distributed lag nonlinear models (DLNM) on rainfall, temperature and relative humidity in relation to dengue incidence. Dengue incidence showed a significant irregular 4-year multi-annual cycle associated with climate variables. Based on GAM, temperature showed a U-shape, while humidity and rainfall exhibited a dome-shaped association, suggesting that deviation from mean temperature increases and deviation from mean humidity and rainfall decreases dengue incidence, respectively. Rainfall was associated with an immediate increase in dengue incidence of 4.1% (95% CI: 2.2-8.1%) after a 10-mm increase, with a maximum increase of 6.5% (95% CI: 3.2-10.0%) after 1.5 month lag. A 1 °C decrease of mean temperature was associated with a RR of 17.4% (95% CI: 11.2-27.0%); the effect was inversed for a 1°C increase of mean temperature (RR= 0.457, 95% CI: 0.278-0.752). Climate variables are important determinants of dengue incidence and provide insight into its short-term effects. An increase in mean temperature was associated with lower dengue incidence, whereas lower temperatures were associated with higher dengue incidence.

  19. Resolving M-dwarf Binaries in Young Moving Groups (YMGs) with MagAO

    NASA Astrophysics Data System (ADS)

    Shan, Yutong; Yee, Jennifer C.; Bowler, Brendan P.

    2017-01-01

    With relatively well-determined ages and uniform histories, YMGs are sparse ensembles of stars that serve as benchmarks for the transition of stellar populations from their birth clusters to the field. We present data and analysis from our Magellan Adaptive Optics (MagAO) campaign to image more than 100 K- and M-dwarf members of several YMGs in the southern sky, revealing ~30 previously unresolved visual stellar companions at separations of ~3 — 300 AU. Knowledge of their binarity is instrumental to interpreting their measured properties for a variety of applications. The tighter of these systems also represent opportunities for future monitoring and dynamical mass inference.Due to faintness and lack of clarity in their YMG memberships (until recently), the multiplicity of PMS M-dwarfs in young associations is hitherto unconstrained. Our study provides statistics for such young M-dwarf multiples in an intermediate regime of orbital distance (across the hard-soft boundary) to populate this little-explored region in the parameter space of multiple star systems. Among the ensemble properties of interest are distributions in physical separations and mass ratios for the binary components. When combined with the SACY survey (Elliott et al. 2015), whose focus is on YMG systems with earlier type primaries, we are able to provide an updated measurement of young-star multiplicity as a function of stellar mass, age, and environment, with significantly more statistical power at lower masses. We discuss implications for the universality and scalability of star formation and evolution processes, as well as comparison to measurements in related populations (e.g. cluster, field, young, old, FGK stars) which form a storyline that theory must explain.

  20. Sea Ice Trends in the AO-UMUKCA model: Interplay of Forcing and Internal Variability

    NASA Astrophysics Data System (ADS)

    Jrrar, Amna; Abraham, Luke; Holland, David; Pyle, John

    2016-04-01

    While Arctic Sea is showing a declining trend particularly in summer. Antarctic sea is showing a modest increase, a very controversial observation in a warming climate. Several studies have attributed these changes to internal variability. Hence in this paper we investigate sea ice trends in both hemispheres as simulated in a version of the Atmosphere-Ocean coupled chemistry climate model AO-UMUKCA under two different atmospheric forcing scenarios. One simulation is a pre-industrial control, where atmospheric forcing is fixed at 1850 level. The second simulation is also a time slice experiment but forced with the year 2000 atmospheric forcing (TS2000). The model simulates a significant reduction in NH Sea Ice Extent (SIE) under the TS2000 scenario, but shows negligible difference in SH SIE between the two scenarios. In agreement with observational studies, we find that NH SIE and distribution are connected to the Arctic Oscillation and the Dipole Anomaly in both simulations, particularly in summer time. While SH winter SIE shows a high correlation with zonal wave-3 pattern and the Pacific South American mode, particularly in TS2000. Connections between SIE and oceanic modes of variability in both hemispheres are also detected. Total NH SIE shows significant correlation with Atlantic Multidecadal Oscillation (AMO) on interannual and decadal timescales, but shows significant correlation with the Inter Pacific Decadal Oscillation (IPO) on multi-decadal timescale only. However, total SH SIE shows significant correlation only with IPO on decadal and multi-decadal scales. The SIE response to oceanic modes is comparable in both simulations.

  1. Interaction of Lamb mode (A(o)) with structural discontinuity and generation of "Turning modes" in a T-joint.

    PubMed

    Ramadas, C; Balasubramaniam, Krishnan; Joshi, M; Krishnamurthy, C V

    2011-07-01

    In the present work, the interaction of the fundamental anti-symmetric guided Lamb mode (A(o)) with a structural discontinuity in a composite structure was studied through Finite Element numerical simulations and experiments. The structural component selected for this study was a T-joint section made from glass/epoxy material. This co-cured composite structure is made-up of an upper shell (skin) and a spar as the sub-components. It was observed that when A(o) mode interacts with the junction (structural discontinuity) of these sub-components, a mode-converted S(o) mode is generated. Experiments were conducted using air-coupled ultrasound to validate the numerical simulations. The back-propagating "Turning modes", which propagate from the thin region to the spar web and vice versa, were also numerically simulated and experimentally verified.

  2. Relativistic blast-wave model for the rapid flux variations of AO 0235+164 and other compact radio sources

    NASA Technical Reports Server (NTRS)

    Marscher, A. P.

    1978-01-01

    A relativistic blast-wave version of a signal-screen model is developed which can adequately explain the details of the flux-density and structural variations of compact extragalactic radio sources. The relativistic motion implied by flux variations is analyzed with respect to the synchrotron spectrum of the BL Lac object AO 0235+164 observed during outbursts, and a signal-screen model for rapidly expanding shells produced by ultrarelativistic blast waves is examined. The approximate observed structure of the blast wave at three stages in its evolution is illustrated, each stage is described, and the model is applied to the flux density outburst in AO 0235+164 observed in late 1975. The results show that a relativistic blast-wave model can in general reproduce the main features of the observed flux variations in compact sources. Some problems with the proposed model are briefly discussed.

  3. First light curve analyses of binary systems AO Aqr, CW Aqr and ASAS 012206-4924.7

    NASA Astrophysics Data System (ADS)

    Ulaş, B.; Ulusoy, C.

    2015-11-01

    Using the data from the public database of the All Sky Automated Survey (ASAS) we performed the very first light curve analyses of the three eclipsing binary systems AO Aqr, CW Aqr and ASAS 012206-4924.7. The physical parameters of the systems were determined by the PHOEBE (Prša and Zwitter, 2005) software. From an analysis of the ASAS data it was concluded that AO Aqr was found to be a contact binary system while CW Aqr and ASAS 012206-4924.7 were found to be near-contact and detached binaries, respectively. Finally, the locations of the components, corresponding to the estimated physical parameters, in the HR diagram were also discussed.

  4. Knee Osteochondritis Dissecans Treated by the AO Hook Fixation System: A Four Year Follow-Up of an Alternative Technique

    PubMed Central

    Pengas, Ioannis P; Assiotis, Angelos; Kokkinakis, Michail; Khan, Wasim S; Meyers, Paul; Arbuthnot, James; Mcnicholas, Michael J

    2014-01-01

    Surgical fixation is recommended for stable osteochondritis dissecans (OCD) lesions that have failed nonoperative management and for all unstable lesions. In this study we set out to describe and evaluate an alternative method of surgical fixation for such lesions. Five knees with unstable OCD lesions in four male adolescent patients with open physes were treated with the AO Hook Fixation System. The outcome was evaluated both clinically and with three separate outcome systems (IKDC 2000, KOOS, Lysholm) at one and a mean four year follow-up. We demonstrated excellent clinical results in all patients. At four years, all scoring systems demonstrated statistically significant improvement when compared to the preoperative status. Our study suggests that the AO Hook Fixation System is an alternative method of surgical intervention with comparable medium term results with other existing modes of fixation and the added biomechanical advantage of the absence of distracting forces during hardware removal. PMID:25067976

  5. Robo-AO Kepler Planetary Candidate Survey. II. Adaptive Optics Imaging of 969 Kepler Exoplanet Candidate Host Stars

    NASA Astrophysics Data System (ADS)

    Baranec, Christoph; Ziegler, Carl; Law, Nicholas M.; Morton, Tim; Riddle, Reed; Atkinson, Dani; Schonhut, Jessica; Crepp, Justin

    2016-07-01

    We initiated the Robo-AO Kepler Planetary Candidate Survey in 2012 to observe each Kepler exoplanet candidate host star with high angular resolution, visible light, laser adaptive optics (AOs) imaging. Our goal is to find nearby stars lying in Kepler's photometric apertures that are responsible for the relatively high probability of false-positive exoplanet detections and that cause underestimates of the size of transit radii. Our comprehensive survey will also shed light on the effects of stellar multiplicity on exoplanet properties and will identify rare exoplanetary architectures. In this second part of our ongoing survey, we observed an additional 969 Kepler planet candidate hosts and we report blended stellar companions up to {{Δ }}m≈ 6 that contribute to Kepler's measured light curves. We found 203 companions within ˜4″ of 181 of the Kepler stars, of which 141 are new discoveries. We measure the nearby star probability for this sample of Kepler planet candidate host stars to be 10.6% ± 1.1% at angular separations up to 2.″5, significantly higher than the 7.4% ± 1.0% probability discovered in our initial sample of 715 stars; we find the probability increases to 17.6% ± 1.5% out to a separation of 4.″0. The median position of Kepler Objects of Interest (KOIs) observed in this survey are 1.°1 closer to the galactic plane, which may account for some of the nearby star probability enhancement. We additionally detail 50 Keck AO images of Robo-AO observed KOIs in order to confirm 37 companions detected at a <5σ significance level and to obtain additional infrared photometry on higher significance detected companions.

  6. Impact of Cn2 profile on tomographic reconstruction performance: application to E-ELT wide field AO systems

    NASA Astrophysics Data System (ADS)

    Costille, A.; Fusco, T.

    2012-07-01

    New techniques of Adaptive Optics (AO), generically called Wide Field AO, have been developed in the frame of the design study for new instruments for Extremely Large Telescopes (ELI). Concepts such as Multi-Conjugate AO are based on a tomographic reconstruction of the turbulent volume followed by a projection onto DM(s) in order to ensure a good correction in a large Field of View. These systems require a 3D phase reconstruction and a statistical representation of the turbulent volume through the knowledge of the Cn2 profile, which has a strong impact on performance. We focus our study on the analysis of the impact of the structure and the parameters, which define the Cn2 profile, on the performance of a given tomographic system for an ELI. In this article, we perform simulation to emphasize the terms which are directly linked to the knowledge of the true input Cn2 profile, which simulates the input turbulent perturbations, and to the Cn2 profile which is used as a model in the reconstruction process. We determine and discuss the level of the accuracy needed on the Cn2 profile to limit the tomographic error term and to ensure a good performance. We show that a good sampling of the input turbulence is required to ensure performance of the system.

  7. Orbital-period variations of the Algol-type eclipsing binaries RW CrB and AO ser

    NASA Astrophysics Data System (ADS)

    Khaliullina, A. I.

    2016-09-01

    Orbital-period variations of the Algol-type eclipsing binaries RW CrB and AO Ser are analyzed. It is shown that the period variations of these systems are due mainly to the light-time effect due to the eclipsing binary's motion in its long-period orbit. The period variations of RW CrB are reproduced by motion of the eclipsing binary with a period of 55.8 years around a third body with the mass M 3 > 0.36 M⊙. The period variations of AO Ser can be reproduced either solely with the light-time effect, or by a superposition of the light-time effect and a slow secular decrease in the period. In the former case, the period of the long-period orbit is 111.5 years; in the latter case, it is 108 years. Both cases imply the same mass for the third body in the AO Ser system: M 3 > 0.35 M⊙. The residual small-amplitude orbitalperiod variations of the two systems can be due to magnetic cycles.

  8. Preparation of AO-related observations and post-processing recipes for E-ELT HARMONI-SCAO

    NASA Astrophysics Data System (ADS)

    Schwartz, Noah; Sauvage, Jean-François; Correia, Carlos; Neichel, Benoît; Blanco, Léonardo; Fusco, Thierry; Pécontal-Rousset, Arlette; Jarno, Aurélien; Piqueras, Laure; Dohlen, Kjetil; El Hadi, Kacem; Thatte, Niranjan; Bryson, Ian; Clarke, Fraser; Schnetler, Hermine

    2016-07-01

    HARMONI is a visible and near-infrared integral field spectrograph designed to be a first-light instrument on the European extremely large telescope. It will use both single-conjugate and laser tomographic adaptive optics to fully exploit high-performance and sky coverage. Using a fast AO modelling toolbox, we simulate anisoplanatism effects on the point spread function of the single-conjugate adaptive optics of HARMONI. We investigate the degradation of the correction performance with respect to the off-axis distance in terms of Strehl ratio and ensquared energy. In addition, we analyse what impact the natural guide source magnitude, AO sampling frequency and number of sub-apertures have on performance. We show, in addition to the expected PSF degradation with the field direction, that the PSF retains a coherent core even at large off-axis distances. We demonstrated the large performance improvement of fine tuning the sampling frequency for dimer natural guide stars and an improvement of approx. 50% in SR can be reached above the nominal case. We show that using a smaller AO system with only 20x20 sub-apertures it is possible to further increase performance and maintain equivalent performance even for large off-axis angles.

  9. HIGH RESOLUTION H{alpha} IMAGES OF THE BINARY LOW-MASS PROPLYD LV 1 WITH THE MAGELLAN AO SYSTEM

    SciTech Connect

    Wu, Y.-L.; Close, L. M.; Males, J. R.; Follette, K.; Morzinski, K.; Kopon, D.; Rodigas, T. J.; Hinz, P.; Puglisi, A.; Esposito, S.; Pinna, E.; Riccardi, A.; Xompero, M.; Briguglio, R.

    2013-09-01

    We utilize the new Magellan adaptive optics system (MagAO) to image the binary proplyd LV 1 in the Orion Trapezium at H{alpha}. This is among the first AO results in visible wavelengths. The H{alpha} image clearly shows the ionization fronts, the interproplyd shell, and the cometary tails. Our astrometric measurements find no significant relative motion between components over {approx}18 yr, implying that LV 1 is a low-mass system. We also analyze Large Binocular Telescope AO observations, and find a point source which may be the embedded protostar's photosphere in the continuum. Converting the H magnitudes to mass, we show that the LV 1 binary may consist of one very-low-mass star with a likely brown dwarf secondary, or even plausibly a double brown dwarf. Finally, the magnetopause of the minor proplyd is estimated to have a radius of 110 AU, consistent with the location of the bow shock seen in H{alpha}.

  10. LDEF (Postflight), AO044 : Holographic Data Storage Crystals for LDEF, Tray E05

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The postflight photograph was taken in SAEF II at KSC prior to removal of the experiment tray from the LDEF. The Holographic Data Storage Crystals for LDEF Experiment (AO044) consist of four crystals of lithium niobate, three crystals contain recorded holograms and one crystal is an unrecorded control sample. The Holographic Data Storage experiment is an integral part of the Active Optical System Component Experiment (S0050) that contains 136 test specimen and is located in a six (6) inch deep LDEF peripheral experiment tray. The experiment tray is divided into six sections, each consisting of a 1/4 inch thick chromic anodized aluminum base plate and a 1/16th inch thick aluminum hat shaped structure for mounting the test specimen. The test specimen are typically placed in fiberglass-epoxy retainer strip assemblies prior to installation on the hat shaped mounting structure. Five of the six sections are covered by a 1/8 inch thick anodized aluminum sun screen with openings that allowed 56 percent transmission over the central region. Two subexperiments, The Optical Materials and UV Detectors Experiment (S0050-01) consist of 15 optical windows, filters and detectors and occupies one of the trays six sub-sections and The Optical Substrates and Coatings Experiment (S0050-02 ) that includes 12 substrates and coatings and a secondary experiment, ThePyroelectric Infrared Detectors Experiment with twenty detectors, are also mounted in the integrated tray. The experiment structure was assembled with non-magnetic stainless steel fasteners. The experiment hardware appears to be intact with no apparent damage. The excess blue color in the flight photograph is no longer present. The paint dots on the tray clamp blocks, initially white, are brown and tray flanges appear to have a light tan discoloration. The experiment sun screens and base plate also appear to have the same discoloration. The exposed experiment test specimen and their fiberglass-epoxy mountings appear to have

  11. Future change of water vaiables from HadGEM2-AO simulation

    NASA Astrophysics Data System (ADS)

    Kim, Moon-Hyun; Kang, Hyun-Suk; Lee, Johan; Baek, Hee-Jeong; Cho, Chunho

    2013-04-01

    hydrology-atmosphere for water resource planning. Arora et al. (1999) and Oki and Sud (1998) developed a method for routing river flows through GCM grid cells. Accordingly, reliable forecasts are expected to help water managers and users with long lead time decisions, leading to greater water use efficiency and better risk management (Wang, 2012). SO, we analysed hydrological cycle and drought index from precipitation, evaporation, runoff, soil moisture, river outflow, and so on using atmosphere-ocean coupled model which called by HadGEM2-AO. Details and added information by this climate projection system about the future water cycle's change will be presented at the workshop. Acknowledgments: This research has been supported by project NIMR-2013-B-2 of the National Institute of Meteorological Research in Korea Meteorological Administration.

  12. Diferentes metodologias aplicadas ao ensino de astronomia no Ensino Médio

    NASA Astrophysics Data System (ADS)

    Albrecht, E.; Voelzke, M. R.

    2009-03-01

    O presente trabalho de intervenção foi realizado junto à Escola Estadual Colònia dos Pescadores na cidade de Caraguatatuba, com très turmas do terceiro ano do Ensino Médio, envolvendo 119 alunos com idades entre 16 e 19 anos. A fase inicial foi composta de um questionário de vinte questíes dissertativas e objetivas, aplicado pelo professor titular da sala, que era o mesmo nas très turmas, para diagnosticar nos educandos os conceitos prévios sobre Astronomia e, partindo destes realizar um trabalho de intervenção nas classes envolvidas utilizando, em cada uma, metodologias diferentes: (A) sob forma de seminários, elaborados e apresentados pelos educandos, no qual o educador faz apenas as intervençíes necessárias; (B) de forma tradicional, com auxílio de multimídias para desenvolvimento das aulas e a terceira (C) tradicional, fazendo uso exclusivo de lousa e giz. Ao final do trabalho os alunos responderam novamente o questionário inicial para diagnosticar dentre as très metodologias utilizadas qual apresentou melhores aplicaçíes, os resultados iniciais foram comparados com os finais. Quando questionados a respeito do significado de Astronomia observou-se inicialmente que os acertos na turma A foram de 100%, turma B: 64%, turma C: 84%, após a intervenção os acertos foram: 100%, 97% e 85% respectivamente, demonstrando que houve um avanço significativo na turma B, a turma A manteve seu índice e a turma C evoluiu, porém não tanto quanto a B. Quando interrogados sobre quantos planetas vocè acha que existem em nosso Sistema Solar? os acertos foram: turma A: 39%, turma B: 48% e turma C: 46%, após o desenvolvimento do trabalho os acertos foram 94%, 97% e 90% respectivamente. Dentro das respostas obtidas observa-se que a metodologia tradicional com o auxílio de multimeios, aplicada na turma B, demonstrou melhores resultados, sendo a mais significativa. Outra conclusão muito importante é que apesar de o tema Astronomia ser amplamente

  13. Deep Uranus Cloud Structure and Methane Mixing Ratio as Constrained by Keck AO Imaging Observations.

    NASA Astrophysics Data System (ADS)

    Sromovsky, Lawrence A.; Fry, P. M.

    2006-09-01

    Keck AO imaging of Uranus in 2004 with H and H-continuum filters provide deep views of scattered light in the Uranian atmosphere with different sensitivities to methane absorption and collision-induced absorption by Hydrogen. After deconvolution, these images provide accurate low-latitude center-to-limb (east-west) profiles out to view angles of nearly 80 degrees, permitting solutions for both cloud properties and the methane mixing ratio. After accounting for a very small high-altitude haze contribution, the observed central disk I/F values for H and H-continuum filters can be modeled using an opaque semi-infinite cloud of very low albedo (near 0.04), a broken cloud of high albedo (fractional coverage near 0.04-.06), or a continuous cloud of low optical depth (0.2-1.0) containing particles of high single-scattering albedo. For low methane mixing ratios (0.5-1 percent) the central disk I/F values require a deep cloud (near 8 bars), while for the high methane mixing ratios (2-4 percent) a higher altitude solution is possible (near 3 bars). However, the observed slightly limb-brightened and relatively flat center-to-limb H-continuum profile is only consistent with an optically thin cloud. The best-fit solution is a low methane mixing ratio (0.75-1.0 percent vmr), and a deep low opacity cloud (optical depth ranging from 0.2 to 0.4 for scattering asymmetry parameters ranging from 0 to 0.3). This CH4 mixing ratio is slightly below the lower limit of the Baines et al. (1995, Icarus 114, 328-340) result of 1.6(+0.7/-0.5) percent. This work was supported by NASA's Planetary Astronomy and Planetary Atmospheres programs and the W.M. Keck Observatory. We thank those of Hawaiian ancestry whose generous hospitality in allowing use of their sacred mountain made the observations possible.

  14. LDEF (Postflight), AO054 : Space Plasma High-Voltage Drainage Experiment, Tray D10

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO054 : Space Plasma High-Voltage Drainage Experiment, Tray D10 The postflight photograph was taken in the SAEF II at KSC prior to removal of the experiment from the LDEF. The experiment trays upper, lower and right flanges have light tan discolorations. The paint dots on clamp blocks located at the centers of the trays upper and right flanges and at the left end of the lower flange have changed from their original white color to a light tan. The SP HVD experiment consist of two identical sets of experiment hardware mounted in three (3) inch deep LDEF experiment trays, one tray is located in the LDEF position B04 adjacent to the LDEF trailing edge and the other is located at LDEF position D10 adjacent to the LDEF leading edge. Each set of SP HVD experiment hardware, self-contained within the experiment tray, consist of six (6) fiberglass reinforced epoxy modules carrying charged dielectric samples on top and the power supplies and electronics below. Four (4) dielectric samples, Kapton with Vapor Deposited Aluminum on one side (VDA-Kapton), are bonded to each of the fiberglass modules with a silver filled conductive epoxy. The spaces between the dielectric sample covered modules and between the modules and the tray flanges are covered by strips of VDA-Kapton attached with acrylic transfer adhesive and Kapton tape. Each experiment tray also contain two solar cell modules. Power for the experiment is provided by LiSO2 batteries supplied by the LDEF Project. The experiment was assembled using non-magnetic stainless steel fasteners. The SP HVD experiment in this tray was severely degraded by impingement of atomic oxygen during the long exposure to the space environment. Most of the Kapton polyimide material making up the dielectric samples was completely eroded leaving only the 2000-3000 angstrom Vapor Deposited Aluminum (VDA) layer bonded to the module. The edges of the dielectric surface that survived were taped over by Kapton tape with a silicone

  15. STAT3 contributes to NK cell recognition by modulating expression of NKG2D ligands in adriamycin-resistant K562/AO2 cells.

    PubMed

    Cai, Xiaohui; Lu, Xuzhang; Jia, Zhuxia; Zhang, Xiuwen; Han, Wenmin; Rong, Xiao; Ma, Lingdi; Zhou, Min; Chen, Baoan

    2015-11-01

    Leukemic cells can survive after chemotherapy by acquisition of multidrug resistance genes, but other phenotypes related to escape from immune recognition remain elusive. Adriamycin-resistant K562/AO2 cells are less susceptible to elimination by NK cells compared with wild type K562 cells due to lower expression of NKG2D ligands. Treatment of K562/AO2 cells with STAT3 inhibitor VII resulted in reduced expression of multidrug resistance gene P-glycoprotein, and up-regulation of NKG2D ligands on K562/AO2 cells. Meanwhile, K562/AO2 cells treated with STAT3 inhibitor proliferated less and were more susceptible to killing by NK cells than untreated K562/AO2 cells. The enhanced cytotoxicity of NK cells against K562/AO2 cells was partly blocked by treatment of NK cells with anti-NKG2D antibodies. These data suggest that STAT3 contributes to NK cell recognition by modulating NKG2D ligands in K562/AO2 cells, which may a mechanism by which cells survive and cause relapse of leukemia.

  16. Novel UNC-44 AO13 ankyrin is required for axonal guidance in C. elegans, contains six highly repetitive STEP blocks separated by seven potential transmembrane domains, and is localized to neuronal processes and the periphery of neural cell bodies.

    PubMed

    Otsuka, Anthony J; Boontrakulpoontawee, Pratumtip; Rebeiz, Natalie; Domanus, Marc; Otsuka, Dawn; Velamparampil, Nena; Chan, Sabrina; Vande Wyngaerde, Marshall; Campagna, Sarah; Cox, Andrea

    2002-03-01

    Conventional ankyrins are cortical cytoskeletal proteins that form an ankyrin-spectrin meshwork underlying the plasma membrane. We report here the unusual structure of a novel ankyrin (AO13 ankyrin, 775,369 Da, 6994 aa, pI = 4.45) that is required for proper axonal guidance in Caenorhabditis elegans. AO13 ankyrin contains the ANK repeat and spectrin-binding domains found in other ankyrins, but differs from all others in that the acidic carboxyl region contains six blocks of serine/threonine/glutamic acid/proline rich (STEP) repeats separated by seven hydrophobic domains. The STEP repeat blocks are composed primarily of sequences related to ETTTTTTVTREHFEPED(E/D)X(n)VVESEEYSASGSPVPSE (E/K)DVE(H/R)VI, and the hydrophobic domains contain sequences related to PESGEESDGEGFGSKVLGFAKK[AGMVAGGVVAAPVALAAVGA]KAAYDALKKDDDEE, which includes a potential transmembrane domain (in brackets). Recombinant protein fragments of AO13 ankyrin were used to prepare polyclonal antisera against the spectrin-binding domain (AO271 Ab), the conventional ankyrin regulatory domain (AO280 Ab), the AO13 ankyrin STEP domain (AO346 Ab), the AO13 ankyrin STEP + hydrophobic domain (AO289 Ab), and against two carboxyl terminal domain fragments (AO263 Ab and AO327 Ab). Western blot analysis with these Ab probes demonstrated multiple protein isoforms. By immunofluorescence microscopy, the antispectrin-binding and regulatory domain (AO271 and AO280) antibodies recognized many cell types, including neurons, and stained the junctions between cells. The AO13 ankyrin-specific (AO289 and AO346) antibodies showed a neurally restricted pattern, staining nerve processes and the periphery of neural cell bodies. These results are consistent with a role for AO13 ankyrin in neural development.

  17. AO/NAO Response to Climate Change. 2; Relative Importance of Low- and High-Latitude Temperature Changes

    NASA Technical Reports Server (NTRS)

    Rind, D.; Perlwitz, J.; Lonergan, P.; Lerner, J.

    2005-01-01

    Using a variety of GCM experiments with various versions of the GISS model, we investigate how different aspects of tropospheric climate changes affect the extratropical Arctic Oscillation (AO)/North Atlantic Oscillation (NAO) circulation indices. The results show that low altitude changes in the extratropical latitudinal temperature gradient can have a strong impact on eddy forcing of the extratropical zonal wind, in the sense that when this latitudinal temperature gradient increases, it helps force a more negative AO/NAO phase. In addition, local conditions at high latitudes can stabilize/destabilize the atmosphere, inducing negative/positive phase changes. To the extent that there is not a large temperature change in the tropical upper troposphere (either through reduced tropical sensitivity at the surface, or limited transport of this change to high levels), the changes in the low level temperature gradient can provide the dominate influence on the extratropical circulation, so that planetary wave meridional refraction and eddy angular momentum transport changes become uncorrelated with potential vorticity transports. In particular, the climate change that produces the most positive NAO phase change would have substantial warming in the tropical upper troposphere over the Pacific Ocean, with high latitude warming in the North Atlantic. An increase in positive phase of these circulation indices is still more likely than not, but it will depend on the degree of tropical and high latitude temperature response and the transport of low level warming into the upper troposphere. These are aspects that currently differ among the models used for predicting the effects of global warning, contributing to the lack of consensus of future changes in the AO/NAO.

  18. Imaging the living retina at the cellular level with AO parallel spectral-domain optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Miller, Donald T.; Zhang, Yan; Rha, Jungtae; Jonnal, Ravi S.; Gao, Weihua

    2005-12-01

    We investigate a novel camera that incorporates adaptive optics (AO) and optical coherence tomography (OCT) to determine if it can achieve the necessary 3-D resolution, sensitivity, and speed for imaging individual cells in the living human retina. An AO spectral-domain OCT system was constructed that is based on a free-space Michelson interferometer design. The OCT sub-system consists of a broadband superluminescent diode whose beam passes through an astigmatic lens to form a line illumination pattern on the retina, which is then imaged onto the slit of an imaging spectrometer. The detector of the spectrometer is a scientific-grade areal CCD. Conventional flood illumination, also with AO, was integrated into the camera and provided confirmation of the focus position in the retina. Short bursts of narrow B-scans (100x560 microns) of the living retina were subsequently acquired at 500 Hz during dynamic compensation that corrected the most significant ocular aberrations across a dilated 6 mm pupil. Camera sensitivity (up to 94 dB) was sufficient for observing reflections from essentially all neural layers of the retina. The 3-D resolution of the B-scans (3.0x3.0x5.7 microns) is the highest reported to date in the living human eye. It was sufficient to observe the interface between the inner and outer segments of individual photoreceptor cells, resolved in both lateral and axial dimensions. The waveguiding nature of the photoreceptors is suggestive at multiple reflective sites. Micro-movements of the retina during short burst imaging allow averaging to reduce speckle contrast, but they appear insufficient for significant speckle reduction.

  19. Removal of surfactants nonylphenol ethoxylates from municipal sewage-comparison of an A/O process and biological aerated filters.

    PubMed

    Gao, Dawen; Li, Zhe; Guan, Junxue; Li, Yifan; Ren, Nanqi

    2014-02-01

    The concentrations of nonylphenol ethoxylates (NPnEO, n=1 to 2) and nonylphenol (NP) in water and sludge samples were measured from a full scale sewage treatment plant (STP) with an Anaerobic/Oxic (A/O) and a Biological Aerated Filter (BAF) process. The A/O process was found to exhibit improved performance in comparison to the BAF process. Mean values of NP, NP1EO and NP2EO concentrations in influents from the STP were similar, ranging from 1.8 to 2.0×10(3)ngL(-1). In the A/O process, the removal efficiency of NP, NP1EO and NP2EO from the aqueous phase was 78%, 84%, and 89%, respectively. In contrast, the removal efficiencies of NP, NP1EO, and NP2EO were relatively lower for the BAF process, at 55%, 76%, and 79%, respectively. High concentrations of NP, NP1EO and NP2EO detected in the sludge samples had a maximum value of 2.7μgg(-1) dw, which indicates that improvement in the overall elimination of NP, NP1EO and NP2EO may be associated with adsorption by the sludge. To further investigate the fate of NP, NP1EO and NP2EO in the STP, our research assessed the degradation characteristics of NP by calculating its transformational loss in the STP. The results demonstrate that the quantity of NP measured in the effluent from the oxic unit increased by 32%, which indicates that NP1EO and NP2EO may undergo degradation in the oxic conditions.

  20. pAO1 of Arthrobacter nicotinovorans and the spread of catabolic traits by horizontal gene transfer in gram-positive soil bacteria.

    PubMed

    Mihasan, Marius; Brandsch, Roderich

    2013-08-01

    The 165-kb megaplasmid pAO1 of Arthrobacter nicotinovorans carries two large gene clusters, one involved in nicotine catabolism (nic-gene cluster) and one in carbohydrate utilization (ch-gene cluster). Here, we propose that both gene clusters were acquired by A. nicotinovorans by horizontal gene transfer mediated by pAO1. Protein-protein blast search showed that none of the published Arthrobacter genomes contains nic-genes, but Rhodococcus opacus carries on its chromosome a nic-gene cluster highly similar to that of pAO1. Analysis of the nic-genes in the two species suggested a recombination event between their nic-gene clusters. Apparently, there was a gene exchange between pAO1, or a precursor plasmid, and a nic-gene cluster of an as yet unidentified Arthrobacter specie or other soil bacterium, possibly related to Rhodococcus, leading to the transfer by pAO1 of this catabolic trait to A. nicotinovorans. Analysis of the pAO1 ch-gene cluster revealed a virtually identical counterpart on the chromosome of Arthrobacter phenanthrenivorans. Moreover, the sequence analysis of the genes flanking the ch-gene cluster suggested that it was acquired by pAO1 by Xer-related site directed recombination and transferred via the plasmid to A. nicotinovorans. The G+C content, the level of sequence identity, gene co-linearity of nic- and ch-gene clusters as well as the signs of recombination events clearly supports the notion of pAO1 and its precursor plasmids as vehicles in HGT among Gram + soil bacteria.

  1. THE FIRST CIRCUMSTELLAR DISK IMAGED IN SILHOUETTE AT VISIBLE WAVELENGTHS WITH ADAPTIVE OPTICS: MagAO IMAGING OF ORION 218-354

    SciTech Connect

    Follette, Katherine B.; Close, Laird M.; Males, Jared R.; Wu, Ya-Lin; Morzinski, Katie M.; Hinz, Philip; Rodigas, Timothy J.; Kopon, Derek; Puglisi, Alfio; Esposito, Simone; Riccardi, Armando; Pinna, Enrico; Xompero, Marco; Briguglio, Runa

    2013-09-20

    We present high-resolution adaptive optics (AO) corrected images of the silhouette disk Orion 218-354 taken with Magellan AO (MagAO) and its visible light camera, VisAO, in simultaneous differential imaging mode at Hα. This is the first image of a circumstellar disk seen in silhouette with AO and is among the first visible light AO results in the literature. We derive the disk extent, geometry, intensity, and extinction profiles and find, in contrast with previous work, that the disk is likely optically thin at Hα. Our data provide an estimate of the column density in primitive, ISM-like grains as a function of radius in the disk. We estimate that only ∼10% of the total submillimeter derived disk mass lies in primitive, unprocessed grains. We use our data, Monte Carlo radiative transfer modeling, and previous results from the literature to make the first self-consistent multiwavelength model of Orion 218-354. We find that we are able to reproduce the 1-1000 μm spectral energy distribution with a ∼2-540 AU disk of the size, geometry, small versus large grain proportion, and radial mass profile indicated by our data. This inner radius is a factor of ∼15 larger than the sublimation radius of the disk, suggesting that it is likely cleared in the very interior.

  2. Property of Cu2O-CuO/ZSM-5 nanocomposite and degradation process of azo dye AO7 without sacrificial agent (H2O2).

    PubMed

    Kong, Wusong; Qu, Hongxia; Chen, Peng; Ma, Weihua; Xie, Huifang

    2016-01-01

    In this study, Cu2O-CuO/ZSM-5 nanocomposite was synthesized by the impregnation method, and its catalytic performance for the destruction of AO7 in aqueous solutions was investigated. The morphology, structure and surface element valence state of Cu2O-CuO/ZSM-5 were characterized by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The operating conditions on the degradation of AO7 by Cu2O-CuO/ZSM-5, such as initial pH values, concentration of AO7 and catalyst dosage were investigated and optimized. The results showed that the sample had good catalytic activity for destruction of AO7 in the absence of a sacrificial agent (e.g. H2O2): it could degrade 91% AO7 in 140 min at 25 °C and was not restricted by the initial pH of the AO7 aqueous solutions. Cu2O-CuO/ZSM-5 exhibited stable catalytic activity with little loss after three successive runs. The total organic carbon and chemical oxygen demand removal efficiencies increased rapidly to 69.36% and 67.3% after 120 min of treatment by Cu2O-CuO/ZSM-5, respectively.

  3. Simultaneous removal of nutrients from milking parlor wastewater using an AO2 sequencing batch reactor (SBR) system.

    PubMed

    Wu, Xiao; Zhu, Jun

    2015-01-01

    The feasibility of using a lab-scale, anaerobic-aerobic-anoxic-aerobic sequencing batch reactor ((AO)2 SBR) to simultaneously remove biological organics, nitrogen and phosphorus from dairy milking parlor wastewater was investigated in this study. Three hydraulic retention times (HRT = 2.1, 2.7, and 3.5 days) and three mixing-to-process time ratios (TM/TP = 0.43, 0.57, and 0.68) were evaluated as two controlling factors using a 3 × 3 experimental design to determine the optimal combination. Results showed that the HRT of 2.7 days with TM/TP = 0.57 was the best to achieve simultaneous nutrients removal for the influent with initial soluble chemical oxygen demand (SCOD) of about 2000 mg L(-1) (only 0.55 mg L(-1) NH4-N, < 0.1 mg L(-1) nitrate, and 0.14 mg L(-1) soluble phosphorus in the effluent). Good correlations between pH and ORP, and ORP and DO, were also obtained with correlation coefficients all higher than or equal to 0.975. These relationships could be used to develop real-time control strategies to optimize the duration of each operating phase in the (AO)2 SBR system to save energy and enhance treatment efficiency.

  4. The Triaxial Ellipsoid Diameters and Rotational Pole of Asteroid (9) Metis from AO at Gemini and Keck

    NASA Astrophysics Data System (ADS)

    Drummond, Jack D.; Merline, W. J.; Conrad, A.; Dumas, C.; Tamblyn, P.; Christou, J.; Carry, B.; Chapman, C.

    2012-10-01

    From Adaptive Optics (AO) images of (9) Metis at 14 epochs over 2008 December 8 and 9 at Gemini North, triaxial ellipsoid diameters of 218x175x112 km are derived with fitting uncertainties of 3x3x47 km. However, by including just two more AO images from Keck-II in June and August of 2003 in a global fit, the fitting uncertainty of the small axis drops by more than a third because of the lower sub-Earth latitude afforded in 2003 (-28°) compared to 2008 (+47°), and the triaxial ellipsoid diameters become 218x175x129 km with fitting uncertainties of 3x3x14 km. We have estimated the systematic uncertainty of our method to be 4.1, 2.7, and 3.8%, respectively, for the three diameters. These values were recently derived (Drummond et al., in prep) from a comparison of KOALA (Carry et al, Planetary and Space Science 66, 200-212) and our triaxial ellipsoid analysis of four asteroids. Quadratically adding this systematic error with the fitting error, the total uncertainty for Metis becomes 9x5x15 km. Concurrently, we find an EQJ2000 rotational pole at [RA; Dec]=[185° +19°] or in ecliptic coordinates, [λ ; β ]=[176° +20°] (ECJ2000).

  5. Insights into Ubiquitination from the Unique Clamp-like Binding of the RING E3 AO7 to the E2 UbcH5B*

    PubMed Central

    Li, Shengjian; Liang, Yu-He; Mariano, Jennifer; Metzger, Meredith B.; Stringer, Daniel K.; Hristova, Ventzislava A.; Li, Jess; Randazzo, Paul A.; Tsai, Yien Che; Ji, Xinhua; Weissman, Allan M.

    2015-01-01

    RING proteins constitute the largest class of E3 ubiquitin ligases. Unlike most RINGs, AO7 (RNF25) binds the E2 ubiquitin-conjugating enzyme, UbcH5B (UBE2D2), with strikingly high affinity. We have defined, by co-crystallization, the distinctive means by which AO7 binds UbcH5B. AO7 contains a structurally unique UbcH5B binding region (U5BR) that is connected by an 11-amino acid linker to its RING domain, forming a clamp surrounding the E2. The U5BR interacts extensively with a region of UbcH5B that is distinct from both the active site and the RING-interacting region, referred to as the backside of the E2. An apparent paradox is that the high-affinity binding of the AO7 clamp to UbcH5B, which is dependent on the U5BR, decreases the rate of ubiquitination. We establish that this is a consequence of blocking the stimulatory, non-covalent, binding of ubiquitin to the backside of UbcH5B. Interestingly, when non-covalent backside ubiquitin binding cannot occur, the AO7 clamp now enhances the rate of ubiquitination. The high-affinity binding of the AO7 clamp to UbcH5B has also allowed for the co-crystallization of previously described and functionally important RING mutants at the RING-E2 interface. We show that mutations having marked effects on function only minimally affect the intermolecular interactions between the AO7 RING and UbcH5B, establishing a high degree of complexity in activation through the RING-E2 interface. PMID:26475854

  6. H-alpha as a Probe of Very Low-mass Planets: The GAPplanetS Survey With the MagAO System

    NASA Astrophysics Data System (ADS)

    Close, L.; MagAO Team

    2014-03-01

    We utilized the new high-order 585 actuator Magellan Adaptive Optics system (MagAO) to obtain very high-resolution visible light images of young Transitional Disk with MagAO's VisAO science camera. In the median seeing conditions of the 6.5m Magellan telescope (0.5 - 0.7''), we find MagAO delivers 24-19% Strehl at Ha (0.656 mm). We detect a faint companion embedded in this young transitional disk system at just 86.3±1.9 mas (~12 AU) from the star. The companion is detected in both Ha and a continuum filter (Dmag=6.33±0.20 mag at Ha and 7.50±0.25 mag in the continuum filter). The Ha emission from the ~0.25 solar mass companion (EW=180 Angstroms) implies a mass accretion rate of ~5.9x10-10 Msun/yr, and a total accretion luminosity of 1.2% Lsun. Assuming a similar accretion rate, we estimate that a 1 Jupiter mass gas giant could have considerably better (50-1,000x) planet/star contrasts at Ha than at H band (COND models) for a range of optical extinctions (3.4-0 mag). We suggest that ~0.5-5 Mjup extrasolar planets in their gas accretion phase could be much more luminous at Ha than in the NIR. This is the motivation for our new MagAO GAPplanetS survey for directly imaging lowmass exoplanets in the gaps of transitional disks in the light of H-alpha with MagAO's unique SDI AO camera.

  7. ROSAT guest investigator program (AO-1). On a search for coronal x ray emissions from white dwarfs

    NASA Technical Reports Server (NTRS)

    Musielak, Z. E.

    1992-01-01

    We have suggested that cool magnetic white dwarfs may be sources of X-ray coronal emission and proposed several prominent candidates for this emission. One of these candidates (EG 250) was approved for the C-category observation by the National and International Committee and was observed by ROSAT on April 17, 1991. Unfortunately, the granted exposure time (1071 s) was much shorter than that which was required by theoretical predictions to observe coronal X-ray emission from this object. The tape containing the data was send to us in November 1991. Since then we have analyzed the data visiting the ROSAT Science Center at NASA Goddard Space Flight Center. The analysis of the data taken during this short observation show, as expected, no X-rays. It is our hope that EG 250 will be observed again during the AO-2 phase of pointed observations, as 10,000 s of observing time was granted to V. Trimble for the C-category observation of this star. We have a close contact with Dr. Trimble regarding this matter. Because our all targets (GD 90, KUV 2316-123 and GD 356) proposed for the observation during the AO-2 phase of pointed observations have been approved by the National and International Committee, we have installed the required software at NASA/MSFC to be able to carry out the data analysis in Huntsville. Two of our targets have already been observed (KUV 2316-123 was observed on Dec. 3, 1991 with 10,000 s of the exposure time, and GD 356 was observed on Jan 4, 1992 with 5,000 s of the exposure time). We just received the data and will begin the analysis soon. The results of our analysis will be reported to the scientific community by publishing papers in the Astrophysical Journal Letters. Our intention is to submit a paper when the analysis of the data taken during AO2 is completed. The data taken during the observation of EG 250 will be a part of this paper.

  8. A1Ao-ATP synthase of Methanobrevibacter ruminantium couples sodium ions for ATP synthesis under physiological conditions.

    PubMed

    McMillan, Duncan G G; Ferguson, Scott A; Dey, Debjit; Schröder, Katja; Aung, Htin Lin; Carbone, Vincenzo; Attwood, Graeme T; Ronimus, Ron S; Meier, Thomas; Janssen, Peter H; Cook, Gregory M

    2011-11-18

    An unresolved question in the bioenergetics of methanogenic archaea is how the generation of proton-motive and sodium-motive forces during methane production is used to synthesize ATP by the membrane-bound A(1)A(o)-ATP synthase, with both proton- and sodium-coupled enzymes being reported in methanogens. To address this question, we investigated the biochemical characteristics of the A(1)A(o)-ATP synthase (MbbrA(1)A(o)) of Methanobrevibacter ruminantium M1, a predominant methanogen in the rumen. Growth of M. ruminantium M1 was inhibited by protonophores and sodium ionophores, demonstrating that both ion gradients were essential for growth. To study the role of these ions in ATP synthesis, the ahaHIKECFABD operon encoding the MbbrA(1)A(o) was expressed in Escherichia coli strain DK8 (Δatp) and purified yielding a 9-subunit protein with an SDS-stable c oligomer. Analysis of the c subunit amino acid sequence revealed that it consisted of four transmembrane helices, and each hairpin displayed a complete Na(+)-binding signature made up of identical amino acid residues. The purified MbbrA(1)A(o) was stimulated by sodium ions, and Na(+) provided pH-dependent protection against inhibition by dicyclohexylcarbodiimide but not tributyltin chloride. ATP synthesis in inverted membrane vesicles lacking sodium ions was driven by a membrane potential that was sensitive to cyanide m-chlorophenylhydrazone but not to monensin. ATP synthesis could not be driven by a chemical gradient of sodium ions unless a membrane potential was imposed. ATP synthesis under these conditions was sensitive to monensin but not cyanide m-chlorophenylhydrazone. These data suggest that the M. ruminantium M1 A(1)A(o)-ATP synthase exhibits all the properties of a sodium-coupled enzyme, but it is also able to use protons to drive ATP synthesis under conditions that favor proton coupling, such as low pH and low levels of sodium ions.

  9. A SURVEY OF THE HIGH ORDER MULTIPLICITY OF NEARBY SOLAR-TYPE BINARY STARS WITH Robo-AO

    SciTech Connect

    Riddle, Reed L.; Bui, Khanh; Dekany, Richard G.; Kulkarni, Shrinivas; Tendulkar, Shriharsh P.; Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.; Roberts, Lewis C. Jr.; Baranec, Christoph; Law, Nicholas M.; Burse, Mahesh P.; Das, H. K.; Punnadi, Sujit; Ramaprakash, A. N.

    2015-01-20

    We conducted a survey of nearby binary systems composed of main sequence stars of spectral types F and G in order to improve our understanding of the hierarchical nature of multiple star systems. Using Robo-AO, the first robotic adaptive optics instrument, we collected high angular resolution images with deep and well-defined detection limits in the Sloan Digital Sky Survey i' band. A total of 695 components belonging to 595 systems were observed. We prioritized observations of faint secondary components with separations over 10'' to quantify the still poorly constrained frequency of their subsystems. Of the 214 secondaries observed, 39 contain such subsystems; 19 of those were discovered with Robo-AO. The selection-corrected frequency of secondary subsystems with periods from 10{sup 3.5} to 10{sup 5} days is 0.12 ± 0.03, the same as the frequency of such companions to the primary. Half of the secondary pairs belong to quadruple systems where the primary is also a close pair, showing that the presence of subsystems in both components of the outer binary is correlated. The relatively large abundance of 2+2 quadruple systems is a new finding, and will require more exploration of the formation mechanism of multiple star systems. We also targeted close binaries with periods less than 100 yr, searching for their distant tertiary components, and discovered 17 certain and 2 potential new triples. In a subsample of 241 close binaries, 71 have additional outer companions. The overall frequency of tertiary components is not enhanced, compared to all (non-binary) targets, but in the range of outer periods from 10{sup 6} to 10{sup 7.5} days (separations on the order of 500 AU), the frequency of tertiary components is 0.16 ± 0.03, exceeding the frequency of similar systems among all targets (0.09) by almost a factor of two. Measurements of binary stars with Robo-AO allowed us to compute first orbits for 9 pairs and to improve orbits of another 11 pairs.

  10. A Survey of the High Order Multiplicity of Nearby Solar-type Binary Stars with Robo-AO

    NASA Astrophysics Data System (ADS)

    Riddle, Reed L.; Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.; Roberts, Lewis C., Jr.; Baranec, Christoph; Law, Nicholas M.; Bui, Khanh; Burse, Mahesh P.; Das, H. K.; Dekany, Richard G.; Kulkarni, Shrinivas; Punnadi, Sujit; Ramaprakash, A. N.; Tendulkar, Shriharsh P.

    2015-01-01

    We conducted a survey of nearby binary systems composed of main sequence stars of spectral types F and G in order to improve our understanding of the hierarchical nature of multiple star systems. Using Robo-AO, the first robotic adaptive optics instrument, we collected high angular resolution images with deep and well-defined detection limits in the Sloan Digital Sky Survey i' band. A total of 695 components belonging to 595 systems were observed. We prioritized observations of faint secondary components with separations over 10'' to quantify the still poorly constrained frequency of their subsystems. Of the 214 secondaries observed, 39 contain such subsystems; 19 of those were discovered with Robo-AO. The selection-corrected frequency of secondary subsystems with periods from 103.5 to 105 days is 0.12 ± 0.03, the same as the frequency of such companions to the primary. Half of the secondary pairs belong to quadruple systems where the primary is also a close pair, showing that the presence of subsystems in both components of the outer binary is correlated. The relatively large abundance of 2+2 quadruple systems is a new finding, and will require more exploration of the formation mechanism of multiple star systems. We also targeted close binaries with periods less than 100 yr, searching for their distant tertiary components, and discovered 17 certain and 2 potential new triples. In a subsample of 241 close binaries, 71 have additional outer companions. The overall frequency of tertiary components is not enhanced, compared to all (non-binary) targets, but in the range of outer periods from 106 to 107.5 days (separations on the order of 500 AU), the frequency of tertiary components is 0.16 ± 0.03, exceeding the frequency of similar systems among all targets (0.09) by almost a factor of two. Measurements of binary stars with Robo-AO allowed us to compute first orbits for 9 pairs and to improve orbits of another 11 pairs.

  11. Electrothermal Annealing (ETA) Method to Enhance the Electrical Performance of Amorphous-Oxide-Semiconductor (AOS) Thin-Film Transistors (TFTs).

    PubMed

    Kim, Choong-Ki; Kim, Eungtaek; Lee, Myung Keun; Park, Jun-Young; Seol, Myeong-Lok; Bae, Hagyoul; Bang, Tewook; Jeon, Seung-Bae; Jun, Sungwoo; Park, Sang-Hee K; Choi, Kyung Cheol; Choi, Yang-Kyu

    2016-09-14

    An electro-thermal annealing (ETA) method, which uses an electrical pulse of less than 100 ns, was developed to improve the electrical performance of array-level amorphous-oxide-semiconductor (AOS) thin-film transistors (TFTs). The practicality of the ETA method was experimentally demonstrated with transparent amorphous In-Ga-Zn-O (a-IGZO) TFTs. The overall electrical performance metrics were boosted by the proposed method: up to 205% for the trans-conductance (gm), 158% for the linear current (Ilinear), and 206% for the subthreshold swing (SS). The performance enhancement were interpreted by X-ray photoelectron microscopy (XPS), showing a reduction of oxygen vacancies in a-IGZO after the ETA. Furthermore, by virtue of the extremely short operation time (80 ns) of ETA, which neither provokes a delay of the mandatory TFTs operation such as addressing operation for the display refresh nor demands extra physical treatment, the semipermanent use of displays can be realized.

  12. VizieR Online Data Catalog: K2 LC of HD 3167 and Robo-AO image (Vanderburg+, 2016)

    NASA Astrophysics Data System (ADS)

    Vanderburg, A.; Bieryla, A.; Duev, D. A.; Jensen-Clem, R.; Latham, D. W.; Mayo, A. W.; Baranec, C.; Berlind, P.; Kulkarni, S.; Law, N. M.; Nieberding, M. N.; Riddle, R.; Maissa, S.

    2016-11-01

    Kepler observed HD 3167 between 2016 January 3 and March 23 during Campaign 8 of its K2 mission. We observed HD 3167 with the Tillinghast Reflector Echelle Spectrograph (TRES) on the 1.5m telescope at the Fred L. Whipple Observatory on Mt. Hopkins, AZ. We acquired one spectrum with a spectral resolving power of R=44000 on 2016 July 11. We observed HD 3167 with the Robo-AO adaptive optics system installed at the 2.1m telescope at Kitt Peak National Observatory. We observed HD 3167 with an i'-band filter on 2016 July 11, taking images at a rate of 8.6Hz for a total of 120s. (2 data files).

  13. A new Huffmanela species, H. schouteni sp. n. (Nematoda: Trichosomoididae) from flying fishes in Curaçao.

    PubMed

    Moravec, F; Campbell, B G

    1991-01-01

    A new nematode species, Huffmanela schouteni sp. n., has been established on the basis of its egg morphology and biological characters (adult nematodes are unknown). The dark-shelled eggs of this histozoic parasite occur in masses in the abdominal cavity, serose covers of internal organs and in the liver of the flying fishes Hirundichthys affinis Günther (type host) and Cypselurus cyanopterus Cuvier et Valenciennes in Curaçao. The eggs of H. schouteni sp. n. differ from those in other congeneric species mainly in the absence of small spines on the surface of the transparent envelope enclosing the egg proper, measurements (size of eggs 0.069-0.075 x 0.027-0.030 mm) and their localization in the host. A key to Huffmanela species based on egg morphology has been provided.

  14. Anomalous pressure dependence of the superconducting transition temperature of beta-pyrochlore AOs2O6 oxides.

    PubMed

    Muramatsu, T; Takeshita, N; Terakura, C; Takagi, H; Tokura, Y; Yonezawa, S; Muraoka, Y; Hiroi, Z

    2005-10-14

    High-pressure effects on the superconducting transitions of beta-pyrochlore oxide superconductors AOs(2)O(6) (A = Cs,Rb,K) are studied by measuring resistivity under high pressures up to 10 GPa. The superconducting transition temperature T(c) first increases with increasing pressure in every compound and then exhibits a broad maximum at 7.6 K (6 GPa), 8.2 K (2 GPa), and 10 K (0.6 GPa) for A = Cs, Rb, and K, respectively. Finally, the superconductivity is suppressed completely at a critical pressure near 7 GPa and 6 GPa for A = Rb and K and probably above 10 GPa for A = Cs. Characteristic changes in the coefficient A of the T(2) term in resistivity and residual resistivity are observed, both of which are synchronized with the corresponding change in T(c).

  15. The First AO Classification System for Fractures of the Craniomaxillofacial Skeleton: Rationale, Methodological Background, Developmental Process, and Objectives.

    PubMed

    Audigé, Laurent; Cornelius, Carl-Peter; Di Ieva, Antonio; Prein, Joachim

    2014-12-01

    Validated trauma classification systems are the sole means to provide the basis for reliable documentation and evaluation of patient care, which will open the gateway to evidence-based procedures and healthcare in the coming years. With the support of AO Investigation and Documentation, a classification group was established to develop and evaluate a comprehensive classification system for craniomaxillofacial (CMF) fractures. Blueprints for fracture classification in the major constituents of the human skull were drafted and then evaluated by a multispecialty group of experienced CMF surgeons and a radiologist in a structured process during iterative agreement sessions. At each session, surgeons independently classified the radiological imaging of up to 150 consecutive cases with CMF fractures. During subsequent review meetings, all discrepancies in the classification outcome were critically appraised for clarification and improvement until consensus was reached. The resulting CMF classification system is structured in a hierarchical fashion with three levels of increasing complexity. The most elementary level 1 simply distinguishes four fracture locations within the skull: mandible (code 91), midface (code 92), skull base (code 93), and cranial vault (code 94). Levels 2 and 3 focus on further defining the fracture locations and for fracture morphology, achieving an almost individual mapping of the fracture pattern. This introductory article describes the rationale for the comprehensive AO CMF classification system, discusses the methodological framework, and provides insight into the experiences and interactions during the evaluation process within the core groups. The details of this system in terms of anatomy and levels are presented in a series of focused tutorials illustrated with case examples in this special issue of the Journal.

  16. Complex AO type C3 distal femur fractures: Results after fixation with a lateral locked plate using modified swashbuckler approach

    PubMed Central

    Agrawal, Anuj; Kiyawat, Vivek

    2017-01-01

    Background: Complex AO type C3 fractures of the distal femur are challenging injuries, fraught with complications such as malunion and stiffness. We prospectively evaluated a consecutive series of patients with complex AO type C3 distal femur fractures to determine the clinicoradiological outcome after fixation with a single locked plate using modified swashbuckler approach. Materials and Methods: 12 patients with C3 type distal femur fractures treated with a lateral locked plate, using a modified swashbuckler approach, were included in the study. The extraarticular component was managed either by compression plating or bridge plating (transarticular approach and retrograde plate osteosynthesis) depending on the fracture pattern. Primary bone grafting was not done in any case. The clinical outcome at 1 year was determined using the Knee Society Score (KSS). The presence of any secondary osteoarthritis in the knee joint was noted at final followup. Results: All fractures united at a mean of 14.3 ± 4.7 weeks (range 6–26 weeks). There were no significant complications such as nonunion, deep infection, and implant failure. One of the patients underwent secondary bone grafting at 3 months. The mean range of motion of the knee was 120° ± 14.8° (range 105°–150°). Seven patients had excellent, three patients had good and two patients had a fair outcome according to the KSS at 1 year. At a mean followup of 17.6 months, three patients showed radiological evidence of secondary osteoarthritis of the knee joint. However, only one of these patients was symptomatic. Conclusion: The results of complex C3 type distal femur fractures, fixed with a single lateral locked plate using a modified swashbuckler approach, are encouraging, with a majority of patients achieving good to excellent outcome at 1 year. PMID:28216747

  17. The First AO Classification System for Fractures of the Craniomaxillofacial Skeleton: Rationale, Methodological Background, Developmental Process, and Objectives

    PubMed Central

    Audigé, Laurent; Cornelius, Carl-Peter; Ieva, Antonio Di; Prein, Joachim

    2014-01-01

    Validated trauma classification systems are the sole means to provide the basis for reliable documentation and evaluation of patient care, which will open the gateway to evidence-based procedures and healthcare in the coming years. With the support of AO Investigation and Documentation, a classification group was established to develop and evaluate a comprehensive classification system for craniomaxillofacial (CMF) fractures. Blueprints for fracture classification in the major constituents of the human skull were drafted and then evaluated by a multispecialty group of experienced CMF surgeons and a radiologist in a structured process during iterative agreement sessions. At each session, surgeons independently classified the radiological imaging of up to 150 consecutive cases with CMF fractures. During subsequent review meetings, all discrepancies in the classification outcome were critically appraised for clarification and improvement until consensus was reached. The resulting CMF classification system is structured in a hierarchical fashion with three levels of increasing complexity. The most elementary level 1 simply distinguishes four fracture locations within the skull: mandible (code 91), midface (code 92), skull base (code 93), and cranial vault (code 94). Levels 2 and 3 focus on further defining the fracture locations and for fracture morphology, achieving an almost individual mapping of the fracture pattern. This introductory article describes the rationale for the comprehensive AO CMF classification system, discusses the methodological framework, and provides insight into the experiences and interactions during the evaluation process within the core groups. The details of this system in terms of anatomy and levels are presented in a series of focused tutorials illustrated with case examples in this special issue of the Journal. PMID:25489387

  18. On-sky Performance Analysis of the Vector Apodizing Phase Plate Coronagraph on MagAO/Clio2

    NASA Astrophysics Data System (ADS)

    Otten, Gilles P. P. L.; Snik, Frans; Kenworthy, Matthew A.; Keller, Christoph U.; Males, Jared R.; Morzinski, Katie M.; Close, Laird M.; Codona, Johanan L.; Hinz, Philip M.; Hornburg, Kathryn J.; Brickson, Leandra L.; Escuti, Michael J.

    2017-01-01

    We report on the performance of a vector apodizing phase plate coronagraph that operates over a wavelength range of 2–5 μm and is installed in MagAO/Clio2 at the 6.5 m Magellan Clay telescope at Las Campanas Observatory, Chile. The coronagraph manipulates the phase in the pupil to produce three beams yielding two coronagraphic point-spread functions (PSFs) and one faint leakage PSF. The phase pattern is imposed through the inherently achromatic geometric phase, enabled by liquid crystal technology and polarization techniques. The coronagraphic optic is manufactured using a direct-write technique for precise control of the liquid crystal pattern and multitwist retarders for achromatization. By integrating a linear phase ramp to the coronagraphic phase pattern, two separated coronagraphic PSFs are created with a single pupil-plane optic, which makes it robust and easy to install in existing telescopes. The two coronagraphic PSFs contain a 180° dark hole on each side of a star, and these complementary copies of the star are used to correct the seeing halo close to the star. To characterize the coronagraph, we collected a data set of a bright (mL = 0–1) nearby star with ∼1.5 hr of observing time. By rotating and optimally scaling one PSF and subtracting it from the other PSF, we see a contrast improvement by 1.46 magnitudes at 3.5 λ /D. With regular angular differential imaging at 3.9 μm, the MagAO vector apodizing phase plate coronagraph delivers a 5σ {{Δ }}{mag} contrast of 8.3 (={10}-3.3) at 2 λ /D and 12.2 (={10}-4.8) at 3.5 λ /D.

  19. Use of the AO veterinary mini 'T'-plate for stabilisation of distal radius and ulna fractures in toy breed dogs.

    PubMed

    Hamilton, M H; Langley Hobbs, S J

    2005-01-01

    The use of the AO (Arbeitsgemeinschaft für Osteosynthesefragen) veterinary mini 'T'-plate for stabilisation of distal radius and ulna fractures in toy breed dogs was evaluated in a retrospective study. All of the 14 dogs in the study weighed 3.5 kg or less. The AO mini 'T'-plate was used as the final means of fixation in all cases. It was used as the primary form of stabilisation in ten dogs, and in four dogs it was used at revision surgery. In all cases, of the fractures healed. Return to function was graded 'as excellent' in six cases, 'good' in four and 'fair' in two. Two dogs were lost to long-term follow up. It was concluded that the AO veterinary mini 'T'-plate is a suitable choice of implant for stabilisation of distal radius and ulna fractures in toy breed dogs, especially when the distal fragment is very small.

  20. Robo-AO Kitt Peak: status of the system and deployment of a sub-electron readnoise IR camera to detect low-mass companions

    NASA Astrophysics Data System (ADS)

    Salama, Maïssa; Baranec, Christoph; Jensen-Clem, Rebecca; Riddle, Reed; Duev, Dmitry; Kulkarni, Shrinivas; Law, Nicholas M.

    2016-07-01

    We have started an initial three-year deployment of Robo-AO at the 2.1-m telescope at Kitt Peak, Arizona as of November 2015. We report here on the project status and two new developments with the Robo-AO KP system: the commissioning of a sub-electron readnoise SAPHIRA near-infrared camera, which will allow us to widen the scope of possible targets to low-mass stellar and substellar objects; and, performance analysis and tuning of the adaptive optics system, which will improve the sensitivity to these objects. Commissioning of the near-infrared camera and optimizing the AO performance occur in parallel with ongoing visible-light science programs.

  1. Promoter isolation and characterization of GhAO-like1, a Gossypium hirsutum gene similar to multicopper oxidases that is highly expressed in reproductive organs.

    PubMed

    Lambret-Frotté, Julia; Artico, Sinara; Muniz Nardeli, Sarah; Fonseca, Fernando; Brilhante Oliveira-Neto, Osmundo; Grossi-de-Sá, Maria Fatima; Alves-Ferreira, Marcio

    2016-01-01

    Cotton is one of the most economically important cultivated crops. It is the major source of natural fiber for the textile industry and an important target for genetic modification for both biotic stress and herbicide tolerance. Therefore, the characterization of genes and regulatory regions that might be useful for genetic transformation is indispensable. The isolation and characterization of new regulatory regions is of great importance to drive transgene expression in genetically modified crops. One of the major drawbacks in cotton production is pest damage; therefore, the most promising, cost-effective, and sustainable method for pest control is the development of genetically resistant cotton lines. Considering this scenario, our group isolated and characterized the promoter region of a MCO (multicopper oxidase) from Gossypium hirsutum, named GhAO-like1 (ascorbate oxidase-like1). The quantitative expression, together with the in vivo characterization of the promoter region reveals that GhAO-like1 has a flower- and fruit-specific expression pattern. The GUS activity is mainly observed in stamens, as expected considering that the GhAO-like1 regulatory sequence is enriched in cis elements, which have been characterized as a target of reproductive tissue specific transcription factors. Both histological and quantitative analyses in Arabidopsis thaliana have confirmed flower (mainly in stamens) and fruit expression of GhAO-like1. In the present paper, we isolated and characterized both in silico and in vivo the promoter region of the GhAO-like1 gene. The regulatory region of GhAO-like1 might be useful to confer tissue-specific expression in genetically modified plants.

  2. Research in elementary particle physics. [Ohio State Univ. , Columbus

    SciTech Connect

    Not Available

    1992-01-01

    Experimental and theoretical work on high energy physics is reviewed. Included are preparations to study high-energy electron-proton interactions at HERA, light-cone QCD, decays of charm and beauty particles, neutrino oscillation, electron-positron interactions at CLEO II, detector development, and astrophysics and cosmology.

  3. Triangular covariance factorizations for. Ph.D. Thesis. - Calif. Univ.

    NASA Technical Reports Server (NTRS)

    Thornton, C. L.

    1976-01-01

    An improved computational form of the discrete Kalman filter is derived using an upper triangular factorization of the error covariance matrix. The covariance P is factored such that P = UDUT where U is unit upper triangular and D is diagonal. Recursions are developed for propagating the U-D covariance factors together with the corresponding state estimate. The resulting algorithm, referred to as the U-D filter, combines the superior numerical precision of square root filtering techniques with an efficiency comparable to that of Kalman's original formula. Moreover, this method is easily implemented and involves no more computer storage than the Kalman algorithm. These characteristics make the U-D method an attractive realtime filtering technique. A new covariance error analysis technique is obtained from an extension of the U-D filter equations. This evaluation method is flexible and efficient and may provide significantly improved numerical results. Cost comparisons show that for a large class of problems the U-D evaluation algorithm is noticeably less expensive than conventional error analysis methods.

  4. Research in particle physics. [Dept. of Physics, Boston Univ

    SciTech Connect

    Whitaker, Scott J.

    1992-09-01

    Research accomplishments and current activities of Boston University researchers in high energy physics are presented. Principal areas of activity include the following: detectors for studies of electron[endash]positron annihilation in colliding beams; advanced accelerator component design, including the superconducting beam inflector, electrostatic quadrupoles, and the electrostatic muon kicker''; the detector for the MACRO (Monopole, Astrophysics, and Cosmic Ray Observatory) experiment; neutrino astrophysics and the search for proton decay; theoretical particle physics (electroweak and flavor symmetry breaking, hadron collider phenomenology, cosmology and astrophysics, new field-theoretic models, nonperturbative investigations of quantum field theories, electroweak interactions); measurement of the anomalous magnetic moment of the muon; calorimetry for the GEM experiment; and muon detectors for the GEM experiment at the Superconducting Super Collider.

  5. Wright St Univ Participation in AFRL University Engineering Design Challenge

    DTIC Science & Technology

    2014-12-23

    significant. The issues with this design arose with the coefficient of friction between the Mylar and the wall, and the large surface area needed to generate...the force. While coating the Mylar with various materials enhanced the coefficient of friction, it also increased the separation of the aluminum and...control was lost and it landed on the power lines. Also this was never tested in a storm in case of lightning. Being aware of what was going on was the

  6. Experimental particle physics. [Dept. of Physics, Drexel Univ

    SciTech Connect

    Steinberg, R.I.; Lane, C.E.

    1992-09-01

    The goals of this research are the experimental testing of fundamental theories of physics beyond the standard model and the exploration of cosmic phenomena through the techniques of particle physics. We are working on the MACRO experiment, which employs a large-area underground detector to search fore grand unification magnetic monopoles and dark matter candidates and to study cosmic ray muons as well as low- and high-energy neutrinos; the Chooz experiment to search for reactor neutrino oscillations at a distance of 1 km from the source; a new proposal (the Perry experiment) to construct a one-kiloton liquid scintillator in the Fairport, Ohio underground facility IMB to study neutrino oscillations with a 13 km baseline; and development of technology for improved liquid scintillators and for very-low-background materials in support of the MACRO and Perry experiments and for new solar neutrino experiments.

  7. Nuclear structure studies with medium energy probes. [Northwestern Univ

    SciTech Connect

    Seth, Kamal K.

    1980-01-01

    Progress in the continuing program of experimental research in nuclear structure with medium-energy probes during the year 1979-1980 is reviewed, and the research activities planned for the year 1980-1981 are discussed. In the study of pion-induced reactions emphasis is placed on investigation of isovector characteristics of nuclear excitations and on double charge exchange reactions. Pion production studies form the major part of the program of experiments with proton beams of 400 to 800 MeV at LAMPF. Current emphasis is on the bearing of these investigations on di-baryon existence. The study of high-spin states and magnetic scattering constitute the main goals of the electron scattering program at Bates. Representative results are presented; completed work is reported in the usual publications. (RWR)

  8. Studies of high energy phenomena using muons. [Northern Illinois Univ

    SciTech Connect

    Hedin, D.; Kaplan, D.; Green, J.

    1993-02-01

    The NIU high energy physics group has three main efforts. The first is the D0 experiment at the Fermilab proton-antiproton collider, with major emphasis on its muon system. The second is the involvement of a portion of the group in Fermilab Experiment 789. Finally, members of the group participate in the SDC collaboration at the SSC.

  9. Deexcitation processes in nuclear reactions. [Dept. of Chemistry, Purdue Univ

    SciTech Connect

    Porile, N.T.

    1992-09-01

    During the past year, our research program has involved continuing analysis of Fermilab E-735, search for quark-gluon plasma (QGP) in {bar p}-p collisions; continuing study of target fragments produced in the interaction of copper with intermediate-energy heavy ions; an exclusive study of multifragmentation using reverse kinematics at the Bevalac; and detector development for the STAR detector at RHIC.

  10. Capillary discharge extreme ultraviolet lasers. [Colorado State Univ. , Ft. Collins

    SciTech Connect

    Rocca, J.J.

    1992-08-01

    The project objective is to explore the generation of soft X-ray laser radiation in a plasma column created by a fast capillary discharge. The proposed capillary lasing scheme offers the potential for compact, simple and efficient soft X-ray laser sources. For this purpose a compact, fast pulse generator which produces 100 kA current pulses with a risetime of 11 ns was constructed. Initial experiments were conducted in evacuated capillaries, in which the plasma is produced by ablation of the capillary walls. The soft X-ray emission from discharges in polyethylene capillary channels was studied to investigate the possibility of amplification in the 3-2 transition of C VI, at {lambda} = 18.2 nm. Time-resolved spectra in which this transition appears anomalously intense with respect to the 4--2 transition of the same ion were obtained. To date, however, this phenomenoa could not be confirmed as gain, as the intensity of the 18.2 nm line has not been observed to increase exponentially as a function of the capillary length. Encouraging results were obtained by fast pulse discharge excitation of capillaries filled with preionized gas. High temperature (Te > 150 eV), small diameter ({approximately}200 {mu}m) plasma columns were efficiently generated. Fast current pulse excitation of a selected low mass density of uniformly preionized material Mag the capillary was observed to detach rapidly the plasma from the capillary walls, and form a plasma channel of a diameter much smaller and significantly hotter than those produced by a similar current pulse in evacuated capillaries of the same size. Discharges in argon-filled capillaries at currents between 20 and 60 kA produced plasmas with ArX-Ar{sub XIV} line emission, and with spectra that are similar to those of plasmas generated by > I MA current implosions in large pulsed power machines. The characteristic of these plasmas approach those necessary for soft X-ray amplification in low Z elements.

  11. Present Status of Networking Conditions in Univ. of South Pacific

    NASA Astrophysics Data System (ADS)

    Takahashi, Fujinobu

    Three years program of Japanese Info-Communication Technology (ICT) Capacity Building Project in the University of South Pacific (USP) will terminate in June 2005. Japanese government has a plan of the new Pacific ICT Center program in USP from 2006. The author will introduce the recent status of USP networking conditions both of satellite and marine cable. The present global VLBI (and even GPS/IGS) network has a weak point of asymmetric distribution by very few number or luck of stations in the huge south Pacific/water hemisphere because of many difficulties such as narrow/poor telecommunication line. It is very important and urgent matters to enhance the space geodetic activities in USP.

  12. Teaching applied optics at the Univ. of Minho

    NASA Astrophysics Data System (ADS)

    Costa, Manuel F. M.

    1995-10-01

    In this communication we make a brief presentation of the branch of Applied Optics of the University of Mihno's undergraduate course of Applied Physics. The course of Applied Physics began in the year 1988/89. Previously we had just a course devoted to the formation of future physics and chemistry teachers at high school level. The Applied Physics course specialized in Optics appeared due to the growth of the physics department and due to request from the industry. The Applied Physics course has two specialization's on the field of applied optics: Optometry; and Optics and Lasers. The topics covered in the two first years of the course ar common to the two branches. On the second semester of the third year the students must choose between either one. The number of students on the Optometry branch was usually almost four times the number of Applied Optics and Lasers students. Nevertheless this tendency is rapidly changing. A short analysis of the result obtained will be presented focusing on last couple of years' advances. Presented will also be the results of an inquest made on students's opinions about the quality of the course, and their own performance and expectations.

  13. Baylor, Univ. of North Texas Students Win EPA Fellowship Grant

    EPA Pesticide Factsheets

    DALLAS - (April 1, 2015) One undergraduate student at Baylor University and another at the University of North Texas were both awarded research fellowship grants by the U.S. Environmental Protection Agency (EPA). The grants were given to students pu

  14. Univ. of Arkansas Student Wins EPA Fellowship Grant

    EPA Pesticide Factsheets

    DALLAS - (April 1, 2015) A student from the University of Arkansas in Fayetteville has received a research fellowship grant from the U.S. Environmental Protection Agency (EPA). EPA issued fellowship grants to students pursuing environmental science

  15. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D05

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D05 EL-1994-00311 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D05 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC after removal of the experiment tray from the LDEF. The experiment tray flanges appear discolored by a brown stain. Outlines of experiment tray clamp blocks are clearly visible on the upper and lower tray flanges. The experiment tray holding fixture hardware covers the clamp block areas on the end flanges. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays lower flange is a copper coated pressure sensitive tape used to provide an electrical ground between the

  16. SRT Evaluation of AIRS Version-6.02 and Version-6.02 AIRS Only (6.02 AO) Products

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Iredell, Lena; Molnar, Gyula; Blaisdell, John

    2012-01-01

    Version-6 contains a number of significant improvements over Version-5. This report compares Version-6 products resulting from the advances listed below to those from Version-5. 1. Improved methodology to determine skin temperature (T(sub s)) and spectral emissivity (Epsilon(sub v)). 2. Use of Neural-net start-up state. 3. Improvements which decrease the spurious negative Version-5 trend in tropospheric temperatures. 4. Improved QC methodology. Version-6 uses separate QC thresholds optimized for Data Assimilation (QC=0) and Climate applications (QC=0,1) respectively. 5. Channel-by-channel clear-column radiances R-hat(sub tau) QC flags. 6. Improved cloud parameter retrieval algorithm. 7. Improved OLR RTA. Our evaluation compared V6.02 and V6.02 AIRS Only (V6.02 AO) Quality Controlled products with those of Version-5.0. In particular we evaluated surface skin temperature T(sub s), surface spectral emissivity Epsilon(sub v), temperature profile T(p), water vapor profile q(p), OLR, OLR(sub CLR), effective cloud fraction alpha-Epsilon, and cloud cleared radiances R-hat(sub tau) . We conducted two types of evaluations. The first compared results on 7 focus days to collocated ECMWF truth. The seven focus days are: September 6, 2002; January 25, 2003; September 29, 2004; August 5, 2005; February 24, 2007; August 10, 2007; and May 30, 2010. In these evaluations, we show results for T(sub s), Epsilon(sub v), T(p), and q(p) in terms of yields, and RMS differences and biases with regard to ECMWF. We also show yield trends as well as bias trends of these quantities relative to ECMWF truth. We also show yields and accuracy of channel by channel QC d values of R-hat(sub tau) for V6.02 and V6.02 AO. Version-5 did not contain channel by channel QC d values of R-hat(sub tau). In the second type of evaluation, we compared V6.03 monthly mean Level-3 products to those of Version-5.0, for four different months: January, April, July, and October; in 3 different years 2003, 2007, and 2011

  17. AO-assisted observations of G61.48+0.09. Massive star formation at high resolution

    NASA Astrophysics Data System (ADS)

    Puga, E.; Alvarez, C.; Feldt, M.; Henning, Th.; Wolf, S.

    2004-10-01

    The characterisation of the stellar populations of ultra-compact HII (UCHII{}) regions is one of the key means of understanding the formation and evolution of massive stars. Adaptive Optics (AO) assisted near-infrared (NIR) observations provide sufficient resolution and sensitivity to detect such populations at moderate extinction values. We present NIR high-resolution observations of G61.48+0.09, a morphologically complex UCHII region with two components, whose accessible stellar content in the NIR has been widely studied before. A polarimetric map in the K' band, as well as H2(1-0) S(1) and Brγ narrow-band images of the region have been obtained with the AO system ALFA at the Calar Alto Observatory's 3.5 m telescope. We also present high-resolution imaging of the same region in the L' band with NAOS+CONICA at the VLT (UT4). The study of the nebular scattered light points to an internal-illumination model for the eastern component (B2). This model is confirmed by the detection of a point-like source in the L'-band data. In the western component (B1) the observed NIR colours of star 82 are consistent with spectral types BIa or early OV, while star 83 is reproduced by a B0V. Therefore, we identify these objects as the main detected ionising sources. However, in terms of illumination, our polarimetric map indicates that these two stars are not the dominating illuminators of the reflection nebula. Illumination from multiple sources (possibly still undetected) seems to influence the polarisation pattern for this component. Geometric considerations in the calculation of the energetics of this region, combined with the knowledge of the detected stellar content, also points to the presence of other ionising sources. Our study reinforces the hypothesis that there is a champagne flow towards the south-west part of the region. Visiting Astronomer, German-Spanish Astronomical Centre, Calar Alto, operated by the Max-Planck-Institute for Astronomy, Heidelberg, jointly with the

  18. Since When or How Often? Dissociating the Roles of Age of Acquisition (AoA) and Lexical Frequency in Early Visual Word Processing

    ERIC Educational Resources Information Center

    Adorni, Roberta; Manfredi, Mirella; Proverbio, Alice Mado

    2013-01-01

    The aim of the study was to investigate the effect of both word age of acquisition (AoA) and frequency of occurrence on the timing and topographical distribution of ERP components. The processing of early- versus late-acquired words was compared with that of high-frequency versus low-frequency words. Participants were asked to perform an…

  19. Sea-level history of past interglacial periods: New evidence from uranium-series dating of corals from Curaçao, Leeward Antilles islands

    USGS Publications Warehouse

    Muhs, Daniel R.; Pandolfi, John M.; Simmons, Kathleen R.; Schumann, R. Randall

    2012-01-01

    Curaçao has reef terraces with the potential to provide sea-levelhistories of interglacialperiods. Ages of the Hato (upper) unit of the "Lower Terrace" indicate that this reef dates to the last interglacialperiod, Marine Isotope Stage (MIS) 5.5. On Curaçao, this high sea stand lasted at least 8000 yr (~ 126 to ~ 118 ka). Elevations and age of this reef show that late Quaternary uplift rates on Curaçao are low, 0.026–0.054 m/ka, consistent with its tectonic setting. Ages of ~ 200 ka for corals from the older Cortalein unit of the Lower Terrace correlate this reef to MIS 7, with paleo-sea level estimates ranging from - 3.3 m to + 2.3 m. The estimates are in agreement with those for MIS 7 made from other localities and indicate that the penultimate interglacialperiod was a time of significant warmth, on a par with the present interglacialperiod. The ~ 400 ka (MIS 11) Middle Terrace I on Curaçao, dated by others, may have formed from a paleo-sea level of + 8.3 to + 10.0 m, or (less likely) + 17 m to + 20 m. The lower estimates are conservative compared to previous studies, but still require major ice sheet loss from Greenland and Antarctica.

  20. LDEF (Postflight), AO133 : Effect of Space Environment on Space-Based Radar Phased-Array Antenna, Tr

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO133 : Effect of Space Environment on Space-Based Radar Phased-Array Antenna, Tray H07 The postflight photograph was taken in the KSC SAEF II facility after the experiment was removed from the LDEF. The Space-Based Radar (SBR) Phased-Array Antenna occupies a six (6) inch deep LDEF end corner tray located on the space end of the LDEF. A light tan discoloration is visible on the left and lower flanges of the experiment tray and also on the unpainted aluminum filler to the left of the passive part of the experiment. A darker stain has discolored the lower corners of the tray structure. The SBR Phased-Array Antenna experiment, consisting of an active part in the upper half of the tray and a passive part located in the lower half of the experiment tray, appears to be intact with no apparent physical damage. The black thermal coating on the active part of the experiment appears to have changed from a flat black to a dark gray while the coating on the passive part of the experiment appears less degraded. The exposed Kapton specimen surfaces in both the active and passive parts of the experiment appear to have changed from specular to diffuse from exposure to the space environment.

  1. Electronic structure properties and superconductivity of the β-pyrochlore Os oxides, AOs2O6 (A=alkali metal)

    NASA Astrophysics Data System (ADS)

    Saniz, R.

    2005-03-01

    The recently discoveredootnotetextT. Muramatsu et al. J. Phys. Soc. Jpn. 73, 10 (2004). family of superconducting β-pyrochlores AOs2O6 (A=alkali metal) represents a particularly interesting example of the interplay between superconductivity and orbital and crystal structure degrees of freedom. Indeed, the pyrochlore lattice formed by the Os-O staggered chains appears to lead to very high Sommerfeld coefficients, increasing of Tc under positive pressure, and other intriguing properties. We present results of a first-principles study of the electronic structure and superconducting properties of these materials (A=Na, K, Rb, and Cs) using the highly precise full-potential linearized augmented plane wave (FLAPW) method.ootnotetextWimmer, Krakauer, Weinert, Freeman, Phys. Rev. B 24, 864 (1981). We show that the observed increase of Tc with decreasing mass of A as well as under positive hydrostatic pressure can both be well understood within a conventional phonon-mediated pairing picture. Furthermore, the density of states at EF depends critically on spin-orbit coupling, due to a van Hove singularity near EF, with a direct effect on Tc; the Fermi surface shows strong nesting, which is reflected in the dynamic susceptibility and thus indicates that spin fluctuations may play an important role in these materials.

  2. Extreme Exoplanet Direct Imaging: New Results with GPI and SCExAO and the Path to Imaging Another Earth

    NASA Astrophysics Data System (ADS)

    Currie, Thayne

    2015-12-01

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

  3. Intracavity KTP optical parametric oscillator driven by a KLM Nd:GGG laser with a single AO modulator

    NASA Astrophysics Data System (ADS)

    Chu, Hongwei; Zhao, Shengzhi; Yang, Kejian; Zhao, Jia; Li, Yufei; Li, Tao; Li, Guiqiu; Li, Dechun; Qiao, Wenchao

    2015-05-01

    An intracavity KTiOPO4 (KTP) optical parametric oscillator (OPO) pumped by a Kerr lens mode-locking (KLM) Nd:GGG laser near 1062 nm with a single AO modulator was realized for the first time. The mode-locking pulses of the signal wave were obtained with a short duration of subnanosecond and a repetition rate of several kilohertz (kHz). Under a diode pump power of 8.25 W, a maximum output power of 104 mW at signal wavelength near 1569 nm was obtained at a repetition rate of 2 kHz. The highest pulse energy and peak power were estimated to be 80 μJ and 102 kW at a repetition rate of 1 kHz, respectively. The shortest pulse duration was measured to be 749 ps. By considering the Gaussian spatial distribution of the photon density and the Kerr-lens effect in the gain medium, a set of the coupled rate equations for QML intracavity optical parametric oscillator are given and the numerical simulations are basically fitted with the experimental results.

  4. Robo-AO Kepler Planetary Candidate Survey. III. Adaptive Optics Imaging of 1629 Kepler Exoplanet Candidate Host Stars

    NASA Astrophysics Data System (ADS)

    Ziegler, Carl; Law, Nicholas M.; Morton, Tim; Baranec, Christoph; Riddle, Reed; Atkinson, Dani; Baker, Anna; Roberts, Sarah; Ciardi, David R.

    2017-02-01

    The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star with laser adaptive optics imaging to search for blended nearby stars, which may be physically associated companions and/or responsible for transit false positives. In this paper, we present the results of our search for stars nearby 1629 Kepler planet candidate hosts. With survey sensitivity to objects as close as ∼0.″15, and magnitude differences Δm ≤slant 6, we find 223 stars in the vicinity of 206 target KOIs; 209 of these nearby stars have not been previously imaged in high resolution. We measure an overall nearby-star probability for Kepler planet candidates of 12.6 % +/- 0.9 % at separations between 0.″15 and 4.″0. Particularly interesting KOI systems are discussed, including 26 stars with detected companions that host rocky, habitable zone candidates and five new candidate planet-hosting quadruple star systems. We explore the broad correlations between planetary systems and stellar binarity, using the combined data set of Baranec et al. and this paper. Our previous 2σ result of a low detected nearby star fraction of KOIs hosting close-in giant planets is less apparent in this larger data set. We also find a significant correlation between detected nearby star fraction and KOI number, suggesting possible variation between early and late Kepler data releases.

  5. [Optimization of nitrate recirculation flow and external carbon dosage integrated control for A/O biological nitrogen removal process].

    PubMed

    Ma, Yong; Peng, Yong-Zhen; Sun, Hong-Wei

    2008-05-01

    In order to improve A/O process denitrification efficiency, five integrated control strategies of nitrate recirculation flow and external carbon dosage for denitrification were proposed and evaluated using the COST/IWA simulation Benchmark. Results show that control strategy No.1 is the best integrated control strategies from both external carbon consumption, effluent quality, and the stability of controller. It comprises two feedback control loops: one is to determine the flow rate of external carbon source, keeping the nitrate concentration at the end of anoxic zone at a pre-specified level 2 mg/L, and the other is to adjust the flow rates of the nitrate recirculation to keep the nitrate concentration at the end of the aerobic zone at a pre-specified level based on the effluent quality (usually 8-12 mg/L). This strategy can guarantee highly effective use of anoxic denitrification capacity in the low-load condition, and meet effluent discharge standards through carbon dosage in the high-load condition.

  6. Rise of The Machines: First Year Operations of The Robo-AO Visible-Light Laser-Adaptive-Optics Instrument

    NASA Astrophysics Data System (ADS)

    Baranec, C.; Riddle, R.; Law, N.; Ramaprakash, A. N.; Tendulkar, S.; Hogstrom, K.; Bui, K.; Burse, M.; Chordia, P.; Das, H.; Dekany, R.

    2013-09-01

    Robo-AO is the first autonomous laser adaptive optics system and science instrument operating on sky. With minimal human oversight, the system robotically executes large scale surveys, monitors long-term astrophysical dynamics and characterizes newly discovered transients, all at the visible diffraction limit. The average target-to-target operational overhead, including slew time, is a mere 86 s, enabling up to ~200 observations per night. The first of many envisioned systems went live in June 2012, and has since finished 51 nights of science observing at the Palomar Observatory 60-inch (1.5 m) telescope, with over 5,600 robotic observations executed as of March 2013. The system will be augmented in late 2013 with a low-noise wide field infrared camera, which will double as a tip-tilt sensor, to widen the spectral bandwidth of observations, increase available sky coverage as well as enable deeper visible imaging using adaptive-optics sharpened infrared tip-tilt guide sources.

  7. Rejuvenation of a ten-year old AO curvature sensor: combining obsolescence correction and performance upgrade of MACAO

    NASA Astrophysics Data System (ADS)

    Haguenauer, P.; Fedrigo, E.; Pettazzi, L.; Reinero, C.; Gonte, F.; Pallanca, L.; Frahm, R.; Woillez, J.; Lilley, P.

    2016-07-01

    The MACAO curvature wavefront sensors have been designed as a generic adaptive optics sensor for the Very Large Telescope. Six systems have been manufactured and implemented on sky: four installed in the UTs Coudé train as an AO facility for the VLTI, and two in UT's instruments, SINFONI and CRIRES. The MACAO-VLTI have now been in use for scientific operation for more than a decade and are planned to be operated for at least ten more years. As second generation instruments for the VLTI were planned to start implementation in end of 2015, accompanied with a major upgrade of the VLTI infrastructure, we saw it as a good time for a rejuvenation project of these systems, correcting the obsolete components. This obsolescence correction also gave us the opportunity to implement improved capabilities: the correction frequency was pushed from 420 Hz to 1050 Hz, and an automatic vibrations compensation algorithm was added. The implementation on the first MACAO was done in October 2014 and the first phase of obsolescence correction was completed in all four MACAO-VLTI systems in October 2015 with the systems delivered back to operation. The resuming of the scientific operation of the VLTI on the UTs in November 2015 allowed to gather statistics in order to evaluate the improvement of the performances through this upgrade. A second phase of obsolescence correction has now been started, together with a global reflection on possible further improvements to secure observations with the VLTI.

  8. Multi-wavelength Observations of Blazar AO 0235+164 in the 2008-2009 Flaring State

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bottacini, E.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cutini, S.; D'Ammando, F.; de Palma, F.; Dermer, C. D.; Silva, E. do Couto e.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Fortin, P.; Fuhrmann, L.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Guiriec, S.; Hadasch, D.; Hayashida, M.; Hughes, R. E.; Itoh, R.; Jóhannesson, G.; Johnson, A. S.; Katagiri, H.; Kataoka, J.; Knödlseder, J.; Kuss, M.; Lande, J.; Larsson, S.; Lee, S.-H.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Mazziotta, M. N.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Nishino, S.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Pelassa, V.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Rastawicki, D.; Razzano, M.; Readhead, A.; Reimer, A.; Reimer, O.; Reyes, L. C.; Richards, J. L.; Sbarra, C.; Sgrò, C.; Siskind, E. J.; Spandre, G.; Spinelli, P.; Szostek, A.; Takahashi, H.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Waite, A. P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Zimmer, S.; Fermi-LAT Collaboration; Moderski, R.; Nalewajko, K.; Sikora, M.; Villata, M.; Raiteri, C. M.; Aller, H. D.; Aller, M. F.; Arkharov, A. A.; Benítez, E.; Berdyugin, A.; Blinov, D. A.; Boettcher, M.; Bravo Calle, O. J. A.; Buemi, C. S.; Carosati, D.; Chen, W. P.; Diltz, C.; Di Paola, A.; Dolci, M.; Efimova, N. V.; Forné, E.; Gurwell, M. A.; Heidt, J.; Hiriart, D.; Jordan, B.; Kimeridze, G.; Konstantinova, T. S.; Kopatskaya, E. N.; Koptelova, E.; Kurtanidze, O. M.; Lähteenmäki, A.; Larionova, E. G.; Larionova, L. V.; Larionov, V. M.; Leto, P.; Lindfors, E.; Lin, H. C.; Morozova, D. A.; Nikolashvili, M. G.; Nilsson, K.; Oksman, M.; Roustazadeh, P.; Sievers, A.; Sigua, L. A.; Sillanpää, A.; Takahashi, T.; Takalo, L. O.; Tornikoski, M.; Trigilio, C.; Troitsky, I. S.; Umana, G.; GASP-WEBT Consortium; Angelakis, E.; Krichbaum, T. P.; Nestoras, I.; Riquelme, D.; F-GAMMA; Krips, M.; Trippe, S.; Iram-PdBI; Arai, A.; Kawabata, K. S.; Sakimoto, K.; Sasada, M.; Sato, S.; Uemura, M.; Yamanaka, M.; Yoshida, M.; Kanata; Belloni, T.; Tagliaferri, G.; RXTE; Bonning, E. W.; Isler, J.; Urry, C. M.; SMARTS; Hoversten, E.; Falcone, A.; Pagani, C.; Stroh, M.; (Swift-XRT

    2012-06-01

    The blazar AO 0235+164 (z = 0.94) has been one of the most active objects observed by Fermi Large Area Telescope (LAT) since its launch in Summer 2008. In addition to the continuous coverage by Fermi, contemporaneous observations were carried out from the radio to γ-ray bands between 2008 September and 2009 February. In this paper, we summarize the rich multi-wavelength data collected during the campaign (including F-GAMMA, GASP-WEBT, Kanata, OVRO, RXTE, SMARTS, Swift, and other instruments), examine the cross-correlation between the light curves measured in the different energy bands, and interpret the resulting spectral energy distributions in the context of well-known blazar emission models. We find that the γ-ray activity is well correlated with a series of near-IR/optical flares, accompanied by an increase in the optical polarization degree. On the other hand, the X-ray light curve shows a distinct 20 day high state of unusually soft spectrum, which does not match the extrapolation of the optical/UV synchrotron spectrum. We tentatively interpret this feature as the bulk Compton emission by cold electrons contained in the jet, which requires an accretion disk corona with an effective covering factor of 19% at a distance of 100 R g. We model the broadband spectra with a leptonic model with external radiation dominated by the infrared emission from the dusty torus.

  9. Determining the Area of Review (AoR) in Carbon Capture and Storage: A tiered, probabilistic methodology to generate risk map

    NASA Astrophysics Data System (ADS)

    Cihan, A.; Siirila-Woodburn, E. R.; Birkholzer, J. T.

    2015-12-01

    The effects and related risks to potable aquifers due to pressure increases and brine leakage through abandoned wells is a poorly understood phenomena and a potentially significant contributor to the risk profile in Geologic Carbon Capture and Storage. Numerical models are used to investigate the evolution of brine leakage (during and post-injection) through wells located in the region where plugged and abandoned (P&A) wellbores leakage could occur. This area, termed tier 3, builds on a 3-tier methodology to define the Area of Review (AoR) proposed by Birkholzer et al. (2013). This work, in conjunction with a quantitative assessment of tier 1 AoR (an area encompassing the CO2 plume) and tier 2 AoR (an are encompassing the extent where open well-bore brine leakage could occur), will lead to a quantitative understanding of potential risks and a metric for the complete spatial extent of environmental risk in Carbon Capture and Storage. Here, we develop a probabilistic methodology to generate "risk maps" related to tier 3 AoR. The risk maps are based on the premise that the two greatest sources of uncertainty in P&A leakage are 1) the location of the unknown well with respect to the injection well and 2) the permeability of the leaky P&A (which can span over several orders of magnitude). The methodology utilizes numerical simulations and probability theory to generate spatial distributions of risk, defined with no-impact or MCL thresholds. Probabilistic risk maps can be used to provide risk-based descriptions of the AoR to inform site selection and monitoring during and post-injection.

  10. A Diffraction-limited Survey for Direct Detection of Halpha Emitting/Accreting ExtraSolar Planets with the 6.5m Magellan Telescope and the MagAO Visible AO system

    NASA Astrophysics Data System (ADS)

    Close, Laird

    TECHNICAL BACKGROUND: An advanced adaptive secondary mirror (ASM) with 585 actuators was commissioned at the 6.5-m Magellan Telescope at one of the world’s best sites (Las Campanas Observatory; LCO) in Chile. By the end of the commissioning run (April 2013) the MagAO system was regularly producing the highest spatial resolution deep images to date (0.023” deep images at Halpha (0.656 microns); Close et al. 2013). This is due to its 378 corrective modes at 1kHz on a 6.5-m telescope. Strehl ratis>20% at Halpha were obtained in 75% of the seeing statistics at the site. We propose here to utilize MagAO’s absolutely unique ability to take Halpha, continuum (0.643 microns), and L’ (3.8 microns) thermal images (all simultaneously) to carry out a novel survey to: Discover a population of the lowest mass young accreting extrasolar planets imaged to date. to characterize the spatial distribution, and estimate accretion rates, of young extrasolar planets >5AU, to understand the influence of planets on transitional disk gaps. THEORY BACKGROUND: Extrasolar planets are very difficult to image directly since planets become very faint below ~8 Mjup (Jupiter masses) for ages >1 Myr and such massive planets are rare. There is a class of young stars that are still accreting yet have SED (and often imaging) evidence of a lack of dust and gas inside a r=5-140 AU “gap”. These “transitional disks” are believed to be transitioning into “disk free” stars. These gaps are believed to be maintained by planets that continuously clear (though scattering or accretion) the optically thin gaps. Indeed large >10 AU gaps (>few Hill spheres) must be maintained by multiple ~1 Mjup planets (Dodson-Robinson & Salyk 2011). Since gas must pass through each of these gaps to continuously supply the accreting star, simulations suggest that these “gap planets” are also crossing points for these gas streamers on their way to the star. These streamers “force-feed” these planets a

  11. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C11

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C11 EL-1994-00299 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C11 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC after removal of the experiment tray from the LDEF. The experiment tray flanges appear discolored by a light brown stain. Outlines of experiment tray clamp blocks are faint but visible on the upper and lower experiment tray flanges.The experiment tray holding fixture hardware covers the clamp block areas on the end flanges. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays lower flange is a copper coated pressure sensitive tape used to provide an electrical ground

  12. Customization of UWB 3D-RTLS Based on the New Uncertainty Model of the AoA Ranging Technique.

    PubMed

    Jachimczyk, Bartosz; Dziak, Damian; Kulesza, Wlodek J

    2017-01-25

    The increased potential and effectiveness of Real-time Locating Systems (RTLSs) substantially influence their application spectrum. They are widely used, inter alia, in the industrial sector, healthcare, home care, and in logistic and security applications. The research aims to develop an analytical method to customize UWB-based RTLS, in order to improve their localization performance in terms of accuracy and precision. The analytical uncertainty model of Angle of Arrival (AoA) localization in a 3D indoor space, which is the foundation of the customization concept, is established in a working environment. Additionally, a suitable angular-based 3D localization algorithm is introduced. The paper investigates the following issues: the influence of the proposed correction vector on the localization accuracy; the impact of the system's configuration and LS's relative deployment on the localization precision distribution map. The advantages of the method are verified by comparing them with a reference commercial RTLS localization engine. The results of simulations and physical experiments prove the value of the proposed customization method. The research confirms that the analytical uncertainty model is the valid representation of RTLS' localization uncertainty in terms of accuracy and precision and can be useful for its performance improvement. The research shows, that the Angle of Arrival localization in a 3D indoor space applying the simple angular-based localization algorithm and correction vector improves of localization accuracy and precision in a way that the system challenges the reference hardware advanced localization engine. Moreover, the research guides the deployment of location sensors to enhance the localization precision.

  13. Deriving the true mass of an unresolved Brown Dwarf companion to an M-Dwarf with AO aided astrometry

    NASA Astrophysics Data System (ADS)

    Meyer, E.; Kürster, M.

    2011-07-01

    From radial velocity (RV) detections alone one does not get all orbital parameters needed to derive the true mass of a non-transiting, unresolved substellar companion to a star. Additional astrometric measurements are needed to calculate the inclination and the longitude of the ascending node. Until today only few true substellar companion masses have been determined by this method with the HST fine guidance sensor [1, 2]. We aim to derive the true mass of a brown dwarf candidate companion to an early M 2.5V dwarf with groundbased high-resolution astrometry aided by adaptive optics. We found this unique brown dwarf desert object, whose distance to the host star is only 0.42 AU, in our UVES precision RV survey of M dwarfs, inferring a minimum companion mass of 27 Jupiter masses [3]. Combining the data with HIPPARCOS astrometry, we found a probability of only 2.9% that the companion is stellar. We therefore observed the host star together with a reference star within a monitoring program with VLT/NACO to derive the true mass of the companion and establish its nature (brown dwarf vs. star). Simultaneous observations of a reference field in a globular cluster are performed to determine the stability of the adaptive optics (AO) plus detector system and check its suitability for such high-precision astrometric measurements over several epochs which are needed to find and analyse extrasolar planet systems. Based on observations collected at the European Southern Observatory, Paranal, Chile, programmes 381.C-0235, 281.C-5057 and 383.C-0248.

  14. Customization of UWB 3D-RTLS Based on the New Uncertainty Model of the AoA Ranging Technique

    PubMed Central

    Jachimczyk, Bartosz; Dziak, Damian; Kulesza, Wlodek J.

    2017-01-01

    The increased potential and effectiveness of Real-time Locating Systems (RTLSs) substantially influence their application spectrum. They are widely used, inter alia, in the industrial sector, healthcare, home care, and in logistic and security applications. The research aims to develop an analytical method to customize UWB-based RTLS, in order to improve their localization performance in terms of accuracy and precision. The analytical uncertainty model of Angle of Arrival (AoA) localization in a 3D indoor space, which is the foundation of the customization concept, is established in a working environment. Additionally, a suitable angular-based 3D localization algorithm is introduced. The paper investigates the following issues: the influence of the proposed correction vector on the localization accuracy; the impact of the system’s configuration and LS’s relative deployment on the localization precision distribution map. The advantages of the method are verified by comparing them with a reference commercial RTLS localization engine. The results of simulations and physical experiments prove the value of the proposed customization method. The research confirms that the analytical uncertainty model is the valid representation of RTLS’ localization uncertainty in terms of accuracy and precision and can be useful for its performance improvement. The research shows, that the Angle of Arrival localization in a 3D indoor space applying the simple angular-based localization algorithm and correction vector improves of localization accuracy and precision in a way that the system challenges the reference hardware advanced localization engine. Moreover, the research guides the deployment of location sensors to enhance the localization precision. PMID:28125056

  15. Practical experience with test-driven development during commissioning of the multi-star AO system ARGOS

    NASA Astrophysics Data System (ADS)

    Kulas, M.; Borelli, Jose Luis; Gässler, Wolfgang; Peter, Diethard; Rabien, Sebastian; Orban de Xivry, Gilles; Busoni, Lorenzo; Bonaglia, Marco; Mazzoni, Tommaso; Rahmer, Gustavo

    2014-07-01

    Commissioning time for an instrument at an observatory is precious, especially the night time. Whenever astronomers come up with a software feature request or point out a software defect, the software engineers have the task to find a solution and implement it as fast as possible. In this project phase, the software engineers work under time pressure and stress to deliver a functional instrument control software (ICS). The shortness of development time during commissioning is a constraint for software engineering teams and applies to the ARGOS project as well. The goal of the ARGOS (Advanced Rayleigh guided Ground layer adaptive Optics System) project is the upgrade of the Large Binocular Telescope (LBT) with an adaptive optics (AO) system consisting of six Rayleigh laser guide stars and wavefront sensors. For developing the ICS, we used the technique Test- Driven Development (TDD) whose main rule demands that the programmer writes test code before production code. Thereby, TDD can yield a software system, that grows without defects and eases maintenance. Having applied TDD in a calm and relaxed environment like office and laboratory, the ARGOS team has profited from the benefits of TDD. Before the commissioning, we were worried that the time pressure in that tough project phase would force us to drop TDD because we would spend more time writing test code than it would be worth. Despite this concern at the beginning, we could keep TDD most of the time also in this project phase This report describes the practical application and performance of TDD including its benefits, limitations and problems during the ARGOS commissioning. Furthermore, it covers our experience with pair programming and continuous integration at the telescope.

  16. Spatiotemporal and species-specific patterns of diseases affecting crustose coralline algae in Curaçao

    NASA Astrophysics Data System (ADS)

    Quéré, G.; Steneck, R. S.; Nugues, M. M.

    2015-03-01

    Distribution and abundance of coral diseases have been well documented, but only a few studies considered diseases affecting crustose coralline algae (CCA), particularly at the species level. We investigated the spatiotemporal dynamics of diseases affecting CCA along the south coast of Curaçao, southern Caribbean. Two syndromes were detected: the Coralline White Band Syndrome (CWBS) previously described and the Coralline White Patch Disease (CWPD) reported here for the first time. Diseases were present at all six study sites, and our results did not reveal a relationship between disease occurrence and human influence. Both diseases were more prevalent on the shallower reef flat than on the deeper reef slope, and during the warm/rainy season than during the cold/dry season. The patterns observed were consistent with a positive link between temperature and disease occurrence. Reef flat communities were dominated by Neogoniolithon mamillare and Paragoniolithon solubile, whereas deeper habitats were dominated by Hydrolithon boergesenii. Diseases affected all the species encountered, and no preferable host was detected. There was a significant relationship between both disease occurrences and CCA cover. Monitoring of affected patches revealed that 90 % of lesions in CWBS increased in size, whereas 88 % of CWPD lesions regenerated over time. CWBS linear progression rate did not vary between seasons or species and ranged from 0.15 to 0.36 cm month-1, which is in the same order of magnitude as rates previously documented. We conclude that diseases have the potential to cause major loss in CCA cover, particularly in shallow waters. As CCA play a key role in reef ecosystems, our study suggests that the emergence of diseases affecting these algae may pose a real threat to coral reef ecosystems. The levels of disease reported here will provide a much-needed local baseline allowing future comparisons.

  17. Magellan adaptive optics first-light observations of the exoplanet β PIC b. I. Direct imaging in the far-red optical with MagAO+VisAO and in the near-IR with NICI {sup ,}

    SciTech Connect

    Males, Jared R.; Close, Laird M.; Morzinski, Katie M.; Skemer, Andrew J.; Kopon, Derek; Follette, Katherine B.; Hinz, Philip M.; Rodigas, Timothy J.; Wahhaj, Zahed; Liu, Michael C.; Nielsen, Eric L.; Chun, Mark; Puglisi, Alfio; Esposito, Simone; Riccardi, Armando; Pinna, Enrico; Xompero, Marco; Briguglio, Runa; Hayward, Thomas L. [Gemini Observatory, Southern Operations Center, c and others

    2014-05-01

    We present the first ground-based CCD (λ < 1 μm) image of an extrasolar planet. Using the Magellan Adaptive Optics system's VisAO camera, we detected the extrasolar giant planet β Pictoris b in Y-short (Y{sub S} , 0.985 μm), at a separation of 0.470 ± 0.''010 and a contrast of (1.63 ± 0.49) × 10{sup –5}. This detection has a signal-to-noise ratio of 4.1 with an empirically estimated upper limit on false alarm probability of 1.0%. We also present new photometry from the Gemini Near-Infrared Coronagraphic Imager instrument on the Gemini South telescope, in CH {sub 4S,1%} (1.58 μm), K{sub S} (2.18 μm), and K {sub cont} (2.27 μm). A thorough analysis of our photometry combined with previous measurements yields an estimated near-IR spectral type of L2.5 ± 1.5, consistent with previous estimates. We estimate log (L {sub bol}/L {sub ☉}) = –3.86 ± 0.04, which is consistent with prior estimates for β Pic b and with field early-L brown dwarfs (BDs). This yields a hot-start mass estimate of 11.9 ± 0.7 M {sub Jup} for an age of 21 ± 4 Myr, with an upper limit below the deuterium burning mass. Our L {sub bol}-based hot-start estimate for temperature is T {sub eff} = 1643 ± 32 K (not including model-dependent uncertainty). Due to the large corresponding model-derived radius of R = 1.43 ± 0.02 R {sub Jup}, this T {sub eff} is ∼250 K cooler than would be expected for a field L2.5 BD. Other young, low-gravity (large-radius), ultracool dwarfs and directly imaged EGPs also have lower effective temperatures than are implied by their spectral types. However, such objects tend to be anomalously red in the near-IR compared to field BDs. In contrast, β Pic b has near-IR colors more typical of an early-L dwarf despite its lower inferred temperature.

  18. Start-up of a two-stage bioaugmented anoxic-oxic (A/O) biofilm process treating petrochemical wastewater under different DO concentrations.

    PubMed

    Guo, Jingbo; Ma, Fang; Chang, Chein-Chi; Cui, Di; Wang, Li; Yang, Jixian; Wang, Liang

    2009-07-01

    The traditional two-stage anoxic-oxic (A/O) activated sludge process might be inefficient in pollutants removal and could not ensure the effluent quality. By installing polyurethane foams as carriers and inoculating specialized bacteria in the oxic compartments, the activated sludge systems could be transformed into bioaugmented biofilm processes to enhance the removal efficiency to recalcitrant pollutants. Optimal environment should be provided for the bioaugmented bacteria during systems' start-up. In the present research, dissolved oxygen (DO) concentration was studied as a crucial environmental factor on the performances of the bioagumented systems. The results indicated that the system adopted lower DO concentration took less time to start-up, performed higher pollutants removal efficiency and stronger resistance to shock loadings compared to the system with higher DO level. This was the first attempt to evaluate the importance of DO concentration on the start-up of the two-stage bioaugmented A/O biofilm process.

  19. Interfragmentary compression and pull-out properties of 6.5-mm AO cancellous lag screws in a uniform synthetic material during tightening procedures.

    PubMed

    Sun, Peidong; Xu, Daqiang; Zhao, Weidong; Jiao, Peifeng; Li, Zeyu; Liu, Chang; Ouyang, Jun

    2017-04-01

    AO lag screws are widely used in surgical intra-articular fracture treatment for anatomical reduction and rigid fixation. Interfragmentary compressive force (IFCF) and pull-out strength (POS) are two critical parameters generated by AO lag screws during tightening, and both of these parameters could be used to estimate screw insert conditions to prevent screw stripping. The aim of this study is to evaluate the IFCF and POS of AO cancellous screws inserted into uniform synthetic cancellous bone during tightening procedures. Seven synthetic cancellous bone blocks were used for this research. Each test contained two continuous portions as follows: the rotation test portion and the pull-out test portion. IFCF and POS were captured by the pressure transducer and the sensor of the test machine. The properties of IFCF and POS based on tightening degrees were obtained in this study. The ideal balance between POS and IFCF during screw tightening exists, and the peak values of these parameters cannot be simultaneously achieved. Moreover, rotation angles of 100-150° appear to serve as the optimum balance between IFCF and POS in the present study.

  20. SIMS chemical analysis of extended impacts on the leading and trailing edges of LDEF experiment AO187-2

    NASA Technical Reports Server (NTRS)

    Amari, S.; Foote, J.; Simon, Charles G.; Swan, P.; Walker, R. M.; Zinner, E.; Jessberger, E. K.; Lange, G.; Stadermann, F.

    1992-01-01

    The Long Duration Exposure Facility (LDEF) Experiment AO187-2 consisted of 237 capture cells, 120 on the leading edge and 117 on the trailing edge. Each cell was made of polished Ge plates covered with 2.5 micron thick mylar foil at 200 microns from the Ge. Although all leading edge cells and 105 trailing edge cells had lost their plastic covers during flight, optical and electron microscope examination revealed extended impacts in bare cells from either edge that apparently were produced by high velocity projectiles while the plastic foils were still in place. Detailed optical scanning yielded 53 extended impacts on 100 bare cells from the trailing edge that were selected for SIMS chemical analysis. Lateral multi-element ion probe profiles were obtained on 40 of these impacts. Material that can be attributed to the incoming projectiles was found in all analyzed extended compact features and most seem to be associated with cosmic dust particles. However, LDEF deposits are systematically enriched in the refractory elements Al, Ca, and Ti relative to Mg and Fe when compared to IDP's collected in the stratosphere and to chondritic compositions. These differences are most likely due to elemental fractionation effects during the high velocity impact but real differences between interplanetary particles captured on LDEF and stratospheric IDP's cannot be excluded. Recently we extended our studies to cells from the leading edge and the covered cells from the trailing edge. The 12 covered cells contain 20 extended impact candidates. Ion probe analysis of 3 yielded results similar to those obtained for impacts on the bare cells from the trailing edge. Optical scanning of the bare leading edge cell also reveals many extended impacts (42 on 22 cells scanned to date), demonstrating that the cover foils remained intact at least for some time. However, SIMS analysis showed elements that can reasonably be attributed to micrometeoroids in only 2 out of 11 impacts. Eight impacts

  1. HIGH-RESOLUTION IMAGES OF ORBITAL MOTION IN THE ORION TRAPEZIUM CLUSTER WITH THE LBT AO SYSTEM

    SciTech Connect

    Close, L. M.; Males, J. R.; Skemer, A.; McCarthy, D. W.; Xompero, M.; Kulesa, C.; Puglisi, A.; Busoni, L.; Pinna, E.; Riccardi, A.; Quiros-Pacheco, F.; Argomedo, J.; Esposito, S.; Mannucci, F.; Arcidiacono, C.; Guerra, J. C.; Brusa, G.; Miller, D. L.; Brynnel, J.; Boutsia, K.; and others

    2012-04-20

    The new 8.4 m LBT adaptive secondary AO system, with its novel pyramid wavefront sensor, was used to produce very high Strehl ({approx}> 75% at 2.16 {mu}m) near-infrared narrowband (Br{gamma}: 2.16 {mu}m and [Fe II]: 1.64 {mu}m) images of 47 young ({approx}1 Myr) Orion Trapezium {theta}{sup 1} Ori cluster members. The inner {approx}41 Multiplication-Sign 53'' of the cluster was imaged at spatial resolutions of {approx}0.''050 (at 1.64 {mu}m). A combination of high spatial resolution and high S/N yielded relative binary positions to {approx}0.5 mas accuracies. Including previous speckle data, we analyze a 15 year baseline of high-resolution observations of this cluster. We are now sensitive to relative proper motions of just {approx}0.3 mas yr{sup -1} (0.6 km s{sup -1} at 450 pc); this is a {approx}7 Multiplication-Sign improvement in orbital velocity accuracy compared to previous efforts. We now detect clear orbital motions in the {theta}{sup 1} Ori B{sub 2} B{sub 3} system of 4.9 {+-} 0.3 km s{sup -1} and 7.2 {+-} 0.8 km s{sup -1} in the {theta}{sup 1} Ori A{sub 1} A{sub 2} system (with correlations of P.A. versus time at >99% confidence). All five members of the {theta}{sup 1} Ori B system appear likely a gravitationally bound 'mini-cluster'. The very lowest mass member of the {theta}{sup 1} Ori B system (B{sub 4}; mass {approx}0.2 M{sub Sun }) has, for the first time, a clearly detected motion (at 4.3 {+-} 2.0 km s{sup -1}; correlation = 99.7%) w.r.t. B{sub 1}. However, B{sub 4} is most likely in a long-term unstable (non-hierarchical) orbit and may 'soon' be ejected from this 'mini-cluster'. This 'ejection' process could play a major role in the formation of low-mass stars and brown dwarfs.

  2. Tracing The Origin Of Methane And Water On Mars: Mapping Regions Of Active Release At Ultra-high Spatial Resolution Using Keck And VLT Under AO Control.

    NASA Astrophysics Data System (ADS)

    Mumma, Michael J.; Villanueva, G. L.; Campbell, R.; Lyke, J.; Conrad, A.; Encrenaz, T.; Hartogh, P.; Kauefl, U.; Novak, R. E.; Tokunaga, A.

    2009-09-01

    Strong release of methane from active regions on Mars has been reported in northern summer (1) and southern spring (2). The spatial resolution of these measurements was about 500 km, sufficient to reveal discrete active regions. Regions of methane release appear mainly over ancient terrain (Noachian/Hesperian) known to have a rich hydration history, and often marked by fossae or other scarps. However, higher resolution is needed to test whether methane release is confined to a small number of narrowly defined vents or is widely distributed over the 500 km footprint. If narrowly confined, the plume should have correspondingly higher local density, enhancing spectral searches for water, methane, their isotopologues, and other trace gases that could reveal aspects of methane generation and depth of release. Ground-based telescopes equipped with both adaptive optics (AO) and high dispersion infrared spectrometers have delivered much higher spatial resolution on planetary bodies, but until now have not been applied to Mars. We acquired images and spectra of Mars under AO control at infrared wavelengths, using Keck-2 and ESO-VLT. In June 2009, we acquired test images with NIRC2/Keck-2 using AO in the natural guide star mode and achieved 0.12” FWHM resolution at 3.0 µm wavelength (Mars diameter was 4.7"). Diffraction-limited performance (0.06” at 3 µm) is expected during follow-up observations in September 2009. We observed Mars with UT1 under AO control (MACAO) in August and September 2009, and acquired spectra with CRIRES. We expect to achieve spatial resolution approaching 40 km in November-December 2009, representing a reduction in area by nearly a factor of 100 compared with earlier non-AO searches. Preliminary results will be presented. This work was funded by NASA grants 08-PAST08-0034 (Planetary Astronomy) and 08-PATM080-0031 (Planetary Atmospheres). 1. Mumma, Villanueva, Novak et al., Science 323, 1041 (2009) 2. Villanueva, Mumma, Novak, (in prep) 2009.

  3. A randomised study in all cervical hip fractures osteosynthesis with Hansson hook-pins versus AO-screws in 199 consecutive patients followed for two years.

    PubMed

    Mjørud, Jan; Skaro, Olav; Solhaug, Jan Helge; Thorngren, Karl-Göran

    2006-08-01

    A consecutive series of patients with all types of cervical hip fracture (both undisplaced and displaced) were randomised to osteosynthesis with Hansson hook-pins (n = 98) or AO-screws (n = 101). Background parameters, fracture type and reduction of the fracture did not differ significantly between the groups. Fifty-seven percent of the patients were operated on within 6 h of admission to hospital, 74% within 12 h and 92% within 24 h. The mean (median) time for operation was 36 (30) min for the hook-pins and 40 (35) min for the AO-screws. The devices were significantly better positioned in the hook-pin group (81% of cases good) compared to the AO-screws (66% good) (p = 0.04). In all, 72% of the patients had no deficiency either in reduction of the fracture, positioning of the implants or had drill penetration of the femoral head. Direct unrestricted weight bearing was encouraged in 92% of the hook-pin and 90% of the AO-screws group. The mean (median) hospital time was 13 (10) days with no significant difference between the groups. Following treatment, 5% walked without aids, 76% of the patients walked with some aids, and 16% could not walk. The walking ability was not known for 4%. At four months, 59% of the patients were living in their own home (64% before fracture), 18% (25% before) in a nursing home, 5% (11% before) in other accommodation and 18% were dead. After two years, 77% of the hook-pin patients had not needed any re-operation compared to 73% in the AO-screw group. In total a secondary hemi-arthroplasty had been performed in 7% and total hip arthroplasty in 12% of the patients. Extraction only of osteosynthesis material had been performed in 5%. The difference in the reoperation rates between the two methods was not significant. In the undisplaced fractures, 84% of the patients had not needed any reoperation after two years compared to 70% among the displaced fractures. Major reoperation had been performed in 10% (1% hemi and 9% total hip arthroplasty

  4. Dose-dependent exposure and metabolism of GNE-892, a β-secretase inhibitor, in monkeys: contributions by P450, AO, and P-gp.

    PubMed

    Takahashi, Ryan; Ma, Shuguang; Yue, Qin; Kim-Kang, Heasook; Yi, Yijun; Lyssikatos, Joseph P; Regal, Kelly; Hunt, Kevin W; Kallan, Nicholas C; Siu, Michael; Hop, Cornelis E C A; Liu, Xingrong; Khojasteh, S Cyrus

    2015-06-01

    (R)-2-Amino-1,3',3'-trimethyl-7'-(pyrimidin-5-yl)-3',4'-dihydro-2'H-spiro[imidazole-4,1'-naphthalen]-5(1H)-one (GNE-892) is an orally administered inhibitor of β-secretase 1 (β-site amyloid precursor protein cleaving enzyme 1, BACE1) that was developed as an intervention therapy against Alzheimer's disease. A clinical microdosing strategy was being considered for de-risking the potential pharmacokinetic liabilities of GNE-892. We tested whether dose-proportionality was observed in cynomolgus monkey as proof-of-concept for a human microdosing study. With cryopreserved monkey hepatocytes, concentration-dependency for substrate turnover and the relative contribution of P450- versus AO-mediated metabolism were observed. Characterization of the kinetics of these metabolic pathways demonstrated differences in the affinities of P450 and AO for GNE-892, which supported the metabolic profiles that had been obtained. To test if this metabolic shift occurred in vivo, mass balance studies in monkeys were conducted at doses of 0.085 and 15 mg/kg. Plasma exposure of GNE-892 following oral administration was more than 20-fold greater than dose proportional at the high-dose. P-gp-mediated efflux was unable to explain the discrepancy. The profiles of metabolites in circulation and excreta were indicative that oxidative metabolism limited the exposure to unchanged GNE-892 at the low dose. Further, the in vivo data supported the concentration-dependent metabolic shift between P450 and AO. In conclusion, microdosing of GNE-892 was not predictive of pharmacokinetics at a more pharmacologically relevant dose due to saturable absorption and metabolism. Therefore, it is important to consider ADME liabilities and their potential concentration-dependency when deciding upon a clinical microdosing strategy.

  5. Backside-illuminated, high-QE, 3e- RoN, fast 700fps, 1760x1680 pixels CMOS imager for AO with highly parallel readout

    NASA Astrophysics Data System (ADS)

    Downing, Mark; Kolb, Johann; Baade, Dietrich; Balard, Philippe; Dierickx, Bart; Defernez, Arnaud; Dupont, Benoit; Feautrier, Philippe; Finger, Gert; Fryer, Martin; Gach, Jean-Luc; Guillaume, Christian; Hubin, Norbert; Iwert, Olaf; Jerram, Paul; Jorden, Paul; Pike, Andrew; Pratlong, Jerome; Reyes, Javier; Stadler, Eric; Walker, Andrew

    2012-07-01

    The success of the next generation of instruments for 8 to 40-m class telescopes will depend upon improving the image quality (correcting the distortion caused by atmospheric turbulence) by exploiting sophisticated Adaptive Optics (AO) systems. One of the critical components of the AO systems for the E-ELT has been identified as the Laser/Natural Guide Star (LGS/NGS) WaveFront Sensing (WFS) detector. The combination of large format, 1760x1680 pixels to finely sample (84x84 sub-apertures) the wavefront and the spot elongation of laser guide stars, fast frame rate of 700 (up to 1000) frames per second, low read noise (< 3e-), and high QE (> 90%) makes the development of such a device extremely challenging. Design studies by industry concluded that a thinned and backside-illuminated CMOS Imager as the most promising technology. This paper describes the multi-phased development plan that will ensure devices are available on-time for E-ELT first-light AO systems; the different CMOS pixel architectures studied; measured results of technology demonstrators that have validated the CMOS Imager approach; the design explaining the approach of massive parallelism (70,000 ADCs) needed to achieve low noise at high pixel rates of ~3 Gpixel/s ; the 88 channel LVDS data interface; the restriction that stitching (required due to the 5x6cm size) posed on the design and the solutions found to overcome these limitations. Two generations of the CMOS Imager will be built: a pioneering quarter sized device of 880x840 pixels capable of meeting first light needs of the E-ELT called NGSD (Natural Guide Star Detector); followed by the full size device, the LGSD (Laser Guide Star Detector). Funding sources: OPTICON FP6 and FP7 from European Commission and ESO.

  6. Variation characteristics and influences of climate factors on aridity index and its association with AO and ENSO in northern China from 1961 to 2012

    NASA Astrophysics Data System (ADS)

    Zhang, Kexin; Qian, Xiaoqing; Liu, Puxing; Xu, Yihong; Cao, Liguo; Hao, Yongpei; Dai, Shengpei

    2016-08-01

    Analyses of the variation characteristics for aridity index (AI) can further enhance the understanding of climate change and have effect on hydrology and agriculture. In this paper, based on the data of 283 standard meteorological stations, the temporal-spatial variations and the influences of climate factors on AI were investigated and the relationship between AI and two climate indices (the Arctic Oscillation (AO); El Nino-Southern Oscillation (ENSO)) were also assessed in northern China (NC) during the period from 1961 to 2012. The results revealed that the annual mean AI decreased at the rate of -0.031 per decade in the past 52 years and the trend was statistically significant at the 0.01 level. The Mann-Kendall (M-K) test presented that the percentages of stations with positive trends and negative trends for AI were 10 and 81.9 % (22.6 % statistically significant), respectively. Spatially, in the western part of 100° E, the extremely dry area declined and the climate tended to become wet obviously. In the eastern part of 100° E, dry area moved toward the east and the south, which resulted in the enhancement of semiarid area and the shrinkage of subhumid area. The contributions of sunshine duration and precipitation to the decline of AI are more than those of other meteorological variables in NC. Moreover, the average temperature has risen significantly and AI decreased in NC, which indicated the existence of "paradox." Relationship between climate indices (AO and ENSO) and AI demonstrated that the influence of ENSO on AI overweight the AO on AI in NC.

  7. [Effects of dissolved oxygen in the oxic parts of A/O reactor on degradation of organic pollutants and analysis of microbial community for treating petrochemical wastewater].

    PubMed

    Ding, Peng-Yuan; Chu, Li-Bing; Zhang, Nan; Wang, Xing; Wang, Jian-Long

    2015-02-01

    Effects of dissolved oxygen (DO) on the biodegradation of organic pollutants were investigated using A/O reactors for the treatment of actual petrochemical wastewater. Two A/O reactors, DO were controlled at 2-3 mg x L(-1) in the oxic parts of reactor A and 5-6 mg x L(-1) of reactor B, were operated in parallel for comparison. The nearly a half of year operation results showed that the effluent COD in reactor A (72.5 ± 14.8 mg x L(-1)) was slightly higher than that in reactor B (68.7 ± 14.6 mg x L(-1)) at a HRT of 20 h. The average COD removal efficiencies were 67.0% and 68.8%, respectively. The effluent ammonium concentration was maintained at 0.8 mg x L(-1) and approximately 95% of ammonium removal was achieved. The effluent BOD, concentration was lower than 5 mg x L(-1). This indicated that the organic pollutants could be degraded thoroughly by the A/O processes, which were affected slightly by DO. Results of 454 pyrosequencing analysis of the sludge in oxic parts showed that at the phylum levels, sequences belonged to Proteobacteria, Planctomycetes and Bacteroidetes were abundant with 58.7% and 59.2%, 14.7% and 12.7%, 10.8% and 12.4% of total bacterial sequences in reactor A and B, respectively. Ammonium oxidation bacteria Nitrosomonas, nitrite oxidizing bacteria Nitrospira and obligate aerobic bacteria were highly enriched in reactor B with high DO levels, while the anaerobic denitrifiers Azospira and Acidovora were highly enriched in reactor A with low DO levels. The identified bacteria belonged to genera Novosphingobium, Comamonas, Sphingobium and Altererythrobacter were reported to degrade PAHs, chloronitrobenzene, pesticides and petroleum, which contributed to the degradation of petrochemical wastewater.

  8. Asteroid (16) Psyche: Triaxial Ellipsoid Dimensions and Rotational Pole from Keck II NIRC2 AO Images and Keck I OSIRIS Images

    NASA Astrophysics Data System (ADS)

    Drummond, Jack D.; Conrad, Al; Reddy, Vishnu; de Kleer, Katherine R.; Adamkovics, Mate; de Pater, Imke; Merline, William J.; Tamblyn, Peter

    2016-10-01

    Adaptive optics (AO) images of asteroid (16) Psyche obtained at 4 epochs with the NIRC2 camera at the 10m W. M. Keck Observatory (Keck II) on UT 2015 December 25 lead to triaxial ellipsoid diameters of 279±4 x 230±2 x 195±14 km, and a rotational pole at RA=29° and Dec=-2°. Adding 6 more epochs obtained nearly simultaneously with the OSIRIS system at Keck I, as well as two more epochs from Keck II in 2009, yields diameters of 273±2 x 232±2 x 165±3 km, and a pole at RA=37° and Dec=+1°. (Errors are formal fit parameter uncertainties; an additional 4% uncertainty is possible from systematic biases.) The differing perspectives between 2015 (sub-Earth latitude Θ=-50°) and 2009 (Θ=-6°) improves primarily the c dimension and the location of the rotational pole, but illustrates how well images from even a single night can determine the size, shape, and pole of an asteroid. The 2015 observations were obtained as part of a campaign to study Psyche with many techniques over a few months, including radar from Arecibo and images from Magellan.These handful of images show the same rugged outline as the radius vector model available on the DAMIT website, constructed from many lightcurves and scaled by previous Keck AO images. In fact Psyche has rotated some 125,350 times between the first lightcurve in 1955 and our 2015 AO images, exactly 60 years apart to the day. Since the asteroid has such a high obliquity, these lightcurves have scanned well into both northern and southern hemispheres. The difference between the pole derived from our images and the radius vector model pole is only 7°, and the mean diameters of Psyche are 219 and 211 km, respectively.

  9. Kahua A'o: A Learning Foundation: Using Hawaiian Language Newspaper Articles for Place and Culture-based Geoscience Teacher Education and Curriculum Development

    NASA Astrophysics Data System (ADS)

    Ellinwood, I.; Stone, K.; Spencer, L.

    2012-12-01

    Kahua A'o is a collaborative project funded by the National Science Foundation aimed at developing science curriculum grounded in Hawaiian culture and place-based education. The project team is composed of members who contribute expertise in meteorology, geology, curriculum development, and Hawaiian language. To date, six lessons have been produced, four with a focus in meteorology and two with a focus in geology. The lessons are geared towards the middle school level, but can easily be adapted for other levels. Each lesson combines a scientific topic with relevant Hawaiian language resources. Serving as the main source for resources is the Hawaiian language newspaper archive, which is an online database of 75,000 pages from newspapers that were published between 1834 and 1948. By incorporating Hawaiian language newspaper articles into science lessons, we aim to teach science through culture and show a history of scientific inquiry intrinsic to Hawaiian culture in order to generate more interest in science among Hawai'i students, especially native Hawaiian students, who are underrepresented in scientific fields. Since most of the articles are specific to the Hawaiian Islands, all students will find more relevance with the lesson through place-based education. Kahua A'o lessons are currently being piloted with groups of public school teachers. Bishop Museum is also incorporating elements of the meteorology lessons into their science education curriculum. The goal of Kahua A'o is to become the first of many such interdisciplinary collaborations, especially those that utilize the rich repository of untapped knowledge in the Hawaiian language newspaper archive.

  10. Amorphization of Al[sub 6]Mn phase in an Al-14 a/o Mn alloy during low energy helium ion bombardment

    SciTech Connect

    Nair, K.G.M.; Krishan, K. . Materials Science Division); Vijayalakshmi, M. . Metallurgy Division)

    1993-10-01

    Amorphization of ordered intermetallic compounds has been observed during ion, electron and neutron irradiations. Investigations have been carried out in a number of systems. It has been generally observed that intermetallic compounds with a narrow range of homogeneity (line compounds) amorphize on irradiation. The present paper reports the observation of irradiation-induced amorphization in the Al[sub 6]Mn phase in an Al-14 a/o Mn alloy. The dose and energy dependence of the amorphization process are discussed. The present studies suggest that the defects produced during irradiation rather than the implanted atoms (helium) play a major role in the crystalline to amorphous transition.

  11. Pleurolucina from the western Atlantic and eastern Pacific Oceans: a new intertidal species from Curaçao with unusual shell microstructure (Mollusca, Bivalvia, Lucinidae)

    PubMed Central

    Glover, Emily A.; Taylor, John D.

    2016-01-01

    Abstract A new shallow water species of the lucinid bivalve Pleurolucina is described from Curaçao in the southern Caribbean Sea and compared with known species of the genus from the western Atlantic and eastern Pacific Oceans. Although confused with the Floridian species Pleurolucina leucocyma, it is most similar to the eastern Pacific Pleurolucina undata. As in all studied lucinids, the new species possesses symbiotic bacteria housed in the ctenidia. The shell microstructure is unusual with repeated and intercalated conchiolin layers that have sublayers of ‘tulip-shaped’ calcareous spherules. Predatory drillings by naticid gastropods frequently terminate at the conchiolin layers. PMID:27853404

  12. A new Liopropoma sea bass (Serranidae, Epinephelinae, Liopropomini) from deep reefs off Curaçao, southern Caribbean, with comments on depth distributions of western Atlantic liopropomins.

    PubMed

    Baldwin, Carole C; Robertson, D Ross

    2014-01-01

    Collecting reef-fish specimens using a manned submersible diving to 300 m off Curaçao, southern Caribbean, is resulting in the discovery of numerous new fish species. The new Liopropoma sea bass described here differs from other western Atlantic members of the genus in having VIII, 13 dorsal-fin rays; a moderately indented dorsal-fin margin; a yellow-orange stripe along the entire upper lip; a series of approximately 13 white, chevron-shaped markings on the ventral portion of the trunk; and a reddish-black blotch on the tip of the lower caudal-fin lobe. The new species, with predominantly yellow body and fins, closely resembles the other two "golden basses" found together with it at Curaçao: L. aberrans and L. olneyi. It also shares morphological features with the other western Atlantic liopropomin genus, Bathyanthias. Preliminary phylogenetic data suggest that western Atlantic liopropomins, including Bathyanthias, are monophyletic with respect to Indo-Pacific Liopropoma, and that Bathyanthias is nested within Liopropoma, indicating a need for further study of the generic limits of Liopropoma. The phylogenetic data also suggest that western Atlantic liopropomins comprise three monophyletic clades that have overlapping depth distributions but different depth maxima (3-135 m, 30-150 m, 133-411 m). The new species has the deepest depth range (182-241 m) of any known western Atlantic Liopropoma species. Both allopatric and depth-mediated ecological speciation may have contributed to the evolution of western Atlantic Liopropomini.

  13. A new Haptoclinus blenny (Teleostei, Labrisomidae) from deep reefs off Curaçao, southern Caribbean, with comments on relationships of the genus.

    PubMed

    Baldwin, Carole C; Robertson, D Ross

    2013-01-01

    A second species of the blenniiform genus Haptoclinus is described from deep reefs off Curaçao, southern Caribbean. Haptoclinus dropi sp. n. differs from the northwestern Caribbean Haptoclinus apectolophus Böhlke and Robins, 1974, in having 29 total dorsal-fin elements-III-I-XIII, 12 (vs. 31-III-I-XIV, 13 or III-I-XIII, 14); 19 anal-fin soft rays (vs. 20-21); 12 pectoral-fin rays (vs. 13); 12 precaudal vertebrae (vs. 13); and the first dorsal-fin spine longer than the second (vs. the second longer than the first). It further differs from Haptoclinus apectolophus in lacking scales (vs. three-quarters of body densely scaled), in having a distinctive pattern of spotting on the trunk and fins in preservative (vs. no spotting), and in lacking a fleshy flap on the anterior rim of the posterior nostril (vs. flap present). Color in life is unknown for Haptoclinus apectolophus, and the color description presented for the new species constitutes the first color information for the genus. Familial placement of Haptoclinus remains questionable, but the limited relevant information obtained from morphological examination of the new species provides additional support for a close relationship with the Chaenopsidae. Haptoclinus dropi represents one of numerous new teleost species emerging from sampling to 300 m off Curaçao as part of the Smithsonian Institution's Deep Reef Observation Project (DROP).

  14. Construction of a mouse Aos1-Uba2 chimeric SUMO-E1 enzyme, mAU, and its expression in baculovirus-insect cells

    PubMed Central

    Nakayama, Tomofumi; Yuasa, Eri; Kanemaru, Ayumi; Saito, Masayuki; Saitoh, Hisato

    2014-01-01

    Small ubiquitin-related modifier (SUMO) is a highly conserved protein that is covalently attached to target proteins. This posttranslational modification, designated SUMOylation, is a major protein-conjugation-driven strategy designed to regulate structure and function of cellular proteins. SUMOylation consists of an enzymatic cascade involving the E1-activating enzyme and the E2-conjugating enzyme. The SUMO-E1 enzyme consists of two subunits, a heterodimer of activation of Smt3p 1 (Aos1) and ubiquitin activating enzyme 2 (Uba2), which resembles the N- and C-terminal halves of ubiquitin E1 (Uba1). Herein, we describe the rational design of a single polypeptide version of SUMO-E1, a chimera of mouse Aos1 and Uba2 subunits, termed mAU, in which the functional domains appear to be arranged in a fashion similar to Uba1. We also describe the construction of a mAU plasmid for expression in a baculovirus-insect cell system and present an in situ SUMOylation assay using the recombinant mAU. Our results showed that mAU has SUMO-E1 activity, thereby indicating that mAU can be expressed in baculovirus-insect cells and represents a suitable source of SUMO-E1. PMID:24637489

  15. The stimulating role of subunit F in ATPase activity inside the A1-complex of the Methanosarcina mazei Gö1 A1AO ATP synthase.

    PubMed

    Singh, Dhirendra; Sielaff, Hendrik; Sundararaman, Lavanya; Bhushan, Shashi; Grüber, Gerhard

    2016-02-01

    A1AO ATP synthases couple ion-transport of the AO sector and ATP synthesis/hydrolysis of the A3B3-headpiece via their stalk subunits D and F. Here, we produced and purified stable A3B3D- and A3B3DF-complexes of the Methanosarcina mazei Gö1 A-ATP synthase as confirmed by electron microscopy. Enzymatic studies with these complexes showed that the M. mazei Gö1 A-ATP synthase subunit F is an ATPase activating subunit. The maximum ATP hydrolysis rates (Vmax) of A3B3D and A3B3DF were determined by substrate-dependent ATP hydrolysis experiments resulting in a Vmax of 7.9 s(-1) and 30.4 s(-1), respectively, while the KM is the same for both. Deletions of the N- or C-termini of subunit F abolished the effect of ATP hydrolysis activation. We generated subunit F mutant proteins with single amino acid substitutions and demonstrated that the subunit F residues S84 and R88 are important in stimulating ATP hydrolysis. Hybrid formation of the A3B3D-complex with subunit F of the related eukaryotic V-ATPase of Saccharomyces cerevisiae or subunit ε of the F-ATP synthase from Mycobacterium tuberculosis showed that subunit F of the archaea and eukaryotic enzymes are important in ATP hydrolysis.

  16. Telescópio de pequeno porte como suporte ao ensino em cidades com intensa poluição luminosa II

    NASA Astrophysics Data System (ADS)

    Pereira, P. C. R.; Santos-Júnior, J. M.; Cruz, W. S.

    2003-08-01

    Para a maioria dos estudantes, sua passagem pelo ensino formal fundamental envolve a transmissão de fatos que devem ser guardados para um exame, a habilidade para lembrar fórmulas e, eventualmente, a repetição de experimentos que devem produzir resultados exigidos pelo professor. O resultado deste modelo de ensino, ao longo dos anos, é conhecido por todos: desconhecimento e descontentamento, por parte dos estudantes, de temas relativos ao papel e aos processos da ciência. Acreditamos que a Astronomia, pelo seu caráter observacional, é uma das áreas do conhecimento que pode contribuir neste cenário. A Fundação Planetário da Cidade do Rio de Janeiro possui um telescópio Meade LX-200 (25cm) que, juntamente com as câmeras CCD ST-7E e ST8E, tem sido utilizado em projetos voltados aos estudantes do ensino médio desde o ano 2000. Tais projetos envolvem a condução de um projeto de pesquisa observacional num nível apropriado, e possibilitam o contato com técnicas e novas tecnologias: computador, software para manipulação de dados e gráficos, programas de tratamento e redução de dados, uso de equipamentos óptico-eletrônicos (telescópio e CCD), bem como o processo de aquisição de conhecimento. Dentro da proposta dos anos anteriores, priorizamos projetos de uma noite, ou seja, procuramos trabalhar com fenômenos que apresentem variabilidade com intervalo de recorrência relativamente curto. Em todos os casos, optamos pela fotometria diferencial, que tem se mostrado bastante eficiente para o céu luminoso como o da cidade do Rio de Janeiro. Neste painel, apresentamos alguns dos projetos desenvolvidos no último ano, com 25 estudantes. Apresentamos os resultados da observação da variável pulsante AI Vel (V = 6,6) e da variável cataclísmica FO Aqr (V = 13,5), e do monitoramento do trânsito da lua de Júpiter, Europa, ocorrido em 30 de abril de 2003. As curvas de luz produzidas para as primeiras estão concordantes com as da literatura, assim

  17. DIFFRACTION-LIMITED VISIBLE LIGHT IMAGES OF ORION TRAPEZIUM CLUSTER WITH THE MAGELLAN ADAPTIVE SECONDARY ADAPTIVE OPTICS SYSTEM (MagAO)

    SciTech Connect

    Close, L. M.; Males, J. R.; Morzinski, K.; Kopon, D.; Follette, K.; Rodigas, T. J.; Hinz, P.; Wu, Y-L.; Puglisi, A.; Esposito, S.; Riccardi, A.; Pinna, E.; Xompero, M.; Briguglio, R.; Uomoto, A; Hare, T.

    2013-09-10

    We utilized the new high-order (250-378 mode) Magellan Adaptive Optics system (MagAO) to obtain very high spatial resolution observations in ''visible light'' with MagAO's VisAO CCD camera. In the good-median seeing conditions of Magellan (0.''5-0.''7), we find MagAO delivers individual short exposure images as good as 19 mas optical resolution. Due to telescope vibrations, long exposure (60 s) r' (0.63 {mu}m) images are slightly coarser at FWHM = 23-29 mas (Strehl {approx}28%) with bright (R < 9 mag) guide stars. These are the highest resolution filled-aperture images published to date. Images of the young ({approx}1 Myr) Orion Trapezium {theta}{sup 1} Ori A, B, and C cluster members were obtained with VisAO. In particular, the 32 mas binary {theta}{sup 1} Ori C{sub 1} C{sub 2} was easily resolved in non-interferometric images for the first time. The relative positions of the bright trapezium binary stars were measured with {approx}0.6-5 mas accuracy. We are now sensitive to relative proper motions of just {approx}0.2 mas yr{sup -1} ({approx}0.4 km s{sup -1} at 414 pc)-this is a {approx}2-10 Multiplication-Sign improvement in orbital velocity accuracy compared to previous efforts. For the first time, we see clear motion of the barycenter of {theta}{sup 1} Ori B{sub 2} B{sub 3} about {theta}{sup 1} Ori B{sub 1}. All five members of the {theta}{sup 1} Ori B system appear likely to be a gravitationally bound ''mini cluster'', but we find that not all the orbits can be both circular and co-planar. The lowest mass member of the {theta}{sup 1} Ori B system (B{sub 4}; mass {approx}0.2 M{sub Sun }) has a very clearly detected motion (at 4.1 {+-} 1.3 km s{sup -1}; correlation = 99.9%) w.r.t. B{sub 1}. Previous work has suggested that B{sub 4} and B{sub 3} are on long-term unstable orbits and will be ejected from this ''mini cluster''. However, our new ''baseline'' model of the {theta}{sup 1} Ori B system suggests a more hierarchical system than previously thought, and so

  18. Determinação de regiões de órbitas diretas estáveis ao redor da Lua

    NASA Astrophysics Data System (ADS)

    de Melo, C. F.; Winter, O. C.; Vieira Neto, E.

    2003-08-01

    Neste Trabalho estamos investigando regiões do sistema Terra-Lua que contêm órbitas diretas estáveis ao redor da Lua visando a utilização destas órbitas em futuras missões de veículos espaciais como alternativas de trajetórias com baixo custo de manutenção. Adotando-se o problema restrito de três corpos, Terra-Lua-partícula, a localização e a extensão destas regiões de estabilidade foram investigadas numericamente considerando como estável toda órbita que permanece ao redor a Lua por, no mínimo, 1000 dias com energia de dois corpos da partícula em relação à Lua negativa. A estabilidade de tais regiões está associada a duas famílias de órbitas periódicas simples H1 e H2 e a órbitas quase-periódicas associadas a elas. Uma vez identificadas as regiões de estabilidade passamos a analisá-las introduzindo, paulatinamente, outras interações relevantes ao sistema como as perturbações do Sol (via problema restrito de quatro corpos), das marés, da pressão de radiação e do achatamento terrestre. Os resultados encontrados até o momento mostram que a perturbação do Sol é a única que reduz significativamente o tamanho das regiões de estabilidade. Também estamos investigando o comportamento de tais regiões quando características intrínsecas do sistema como as excentricidades das órbitas da Terra e da Lua e a inclinação da órbita Lua são consideradas. Com este estudo estamos reunindo informações que nos permitirão compreender a evolução das regiões de estabilidade no sistema Terra-Lua, bem como estabelecer parâmetros adequados para a utilização das trajetórias estáveis em futuras missões espaciais. Agradecimentos: Este projeto conta com o apoio do CNPq, da Capes e da Fapesp.

  19. NEARLY PERIODIC FLUCTUATIONS IN THE LONG-TERM X-RAY LIGHT CURVES OF THE BLAZARS AO 0235+164 AND 1ES 2321+419

    SciTech Connect

    Rani, Bindu; Gupta, Alok C.; Wiita, Paul J. E-mail: acgupta30@gmail.com

    2009-05-10

    We have performed a structure function analysis of the Rossi X-Ray Timing Explorer All-Sky Monitor data to search for variability in 24 blazars using data trains that each exceed 12 yr. Although 20 of them show nominal periods through this technique, the great majority of these 'periods' are clearly related to yearly variations arising from the instrument. Nonetheless, an apparently real periodic component of about 17 days was detected for the blazar AO 0235+164 and it was confirmed by discrete correlation function and periodogram analyses. For 1ES 2321+419, a component of variability with a near periodicity of about 420 days was detected by all of these methods. We discuss several possible explanations for these nearly periodic components and conclude that they most likely arise from the intersections of a shock propagating down a relativistic jet that possesses a helical structure.

  20. Levels, composition profiles and sources of polycyclic aromatic hydrocarbons in surface sediments from Nan'ao Island, a representative mariculture base in South China.

    PubMed

    Gu, Yang-Guang; Lin, Qin; Lu, Teng-Teng; Ke, Chang-Liang; Sun, Run-Xia; Du, Fei-Yan

    2013-10-15

    Levels, composition profiles and sources of 16 polycyclic aromatic hydrocarbons (PAHs) in surface sediments from Nan'ao Island, one of the largest mariculture bases in South China were investigated. The total PAHs concentrations ranged from 265.49 to 951.27 ng/g (dry weight) with a mean of 515.90 ng/g, and seven possible carcinogenic PAHs accounted for 76.94% of total PAHs. Among various mariculture sections, the highest PAHs level was found in the large seaweed culture; while the lowest concentration was detected in the abandoned culture. The composition of PAHs was characterized by low molecular weight PAHs, and Phe Ant and Pyr were the dominant constituent. PAHs may be mainly originated from petroleum and combustion of biomass and coal. Risk assessments suggested that the probability of adverse effect was lower than 25% and PAHs exposure was moderately carcinogenic.

  1. Dynamic hip screw versus proximal femur locking compression plate in intertrochanteric femur fractures (AO 31A1 and 31A2): A prospective randomized study

    PubMed Central

    Agrawal, Prabhat; Gaba, Sahil; Das, Saubhik; Singh, Ranjit; Kumar, Arvind; Yadav, Gajanand

    2017-01-01

    Introduction: Intertrochanteric fractures are common in elderly population and pose a significant financial burden to the society. Anatomically contoured proximal femur locking compression plate (PFLCP) is the latest addition in the surgeons’ armamentarium to deal with these fractures. It creates an angular stable construct, which will theoretically lessen the risk of failure by screw cut-out and varus collapse, the common mode of DHS failure. We compared DHS with PFLCP in AO type 31A1 and 31A2 intertrochanteric fractures. Materials and Methods: A randomized prospective study was carried out between June 2011 and June 2013. 26 cases each of DHS and PFLCP were included. Results: Functional and radiological outcome was similar in both groups. Conclusion: Both DHS and PFLCP are good choices for stable intertrochanteric fractures, and both lead to excellent functional outcomes, but non-union might be more common with PFLCP.

  2. Cluster Glimpses with RAVEN: AO-corrected Near and Mid-infrared Images of GLIMPSE C01 and GLIMPSE C02

    NASA Astrophysics Data System (ADS)

    Davidge, T. J.; Andersen, D. R.; Lardière, O.; Bradley, C.; Blain, C.; Oya, S.; Terada, H.; Hayano, Y.; Lamb, M.; Akiyama, M.; Ono, Y. H.; Suzuki, G.

    2016-12-01

    We discuss images of the star clusters GLIMPSE C01 (GC01) and GLIMPSE C02 (GC02) that were recorded with the Subaru IRCS. Distortions in the wavefront were corrected with the RAVEN adaptive optics (AO) science demonstrator, allowing individual stars in the central regions of both clusters—where the fractional contamination from non-cluster objects is lowest—to be imaged. In addition to J, H, and K‧ images, both clusters were observed through a narrow-band filter centered near 3.05 μm GC01 was also observed through two other narrow-band filters that sample longer wavelengths. Stars in the narrow-band images have an FWHM that is close to the telescope diffraction limit, demonstrating that open-loop AO systems like RAVEN can deliver exceptional image quality. The near-infrared color-magnitude diagram of GC01 is smeared by non-uniform extinction with a 1σ dispersion ΔA K = ±0.13 mag. Spatial variations in A K are not related in a systematic way to location in the field. The Red Clump is identified in the K luminosity function (LF) of GC01, and a distance modulus of 13.6 is found. The K LF of GC01 is consistent with a system that is dominated by stars with an age >1 Gyr. As for GC02, the K LF is flat for K > 16, and the absence of a sub-giant branch argues against an old age if the cluster is at a distance of ˜7 kpc. Archival SPITZER [3.6] and [4.5] images of the clusters are also examined, and the red giant branch-tip is identified. It is demonstrated in the Appendix that the [3.6] surface brightness profiles of both clusters can be traced out to radii of at least 100 arcsec.

  3. A new Liopropoma sea bass (Serranidae, Epinephelinae, Liopropomini) from deep reefs off Curaçao, southern Caribbean, with comments on depth distributions of western Atlantic liopropomins

    USGS Publications Warehouse

    Baldwin, Carole C.; Robertson, D. Ross

    2014-01-01

    Collecting reef-fish specimens using a manned submersible diving to 300 m off Curaçao, southern Caribbean, is resulting in the discovery of numerous new fish species. The new Liopropoma sea bass described here differs from other western Atlantic members of the genus in having VIII, 13 dorsal-fin rays; a moderately indented dorsal-fin margin; a yellow-orange stripe along the entire upper lip; a series of approximately 13 white, chevron-shaped markings on the ventral portion of the trunk; and a reddish-black blotch on the tip of the lower caudal-fin lobe. The new species, with predominantly yellow body and fins, closely resembles the other two “golden basses” found together with it at Curaçao: L. aberransand L. olneyi. It also shares morphological features with the other western Atlantic liopropomin genus,Bathyanthias. Preliminary phylogenetic data suggest that western Atlantic liopropomins, includingBathyanthias, are monophyletic with respect to Indo-Pacific Liopropoma, and that Bathyanthias is nested within Liopropoma, indicating a need for further study of the generic limits of Liopropoma. The phylogenetic data also suggest that western Atlantic liopropomins comprise three monophyletic clades that have overlapping depth distributions but different depth maxima (3–135 m, 30–150 m, 133–411 m). The new species has the deepest depth range (182–241 m) of any known western Atlantic Liopropomaspecies. Both allopatric and depth-mediated ecological speciation may have contributed to the evolution of western Atlantic Liopropomini.

  4. A Worldwide Analysis of the Reliability and Perceived Importance of an Injury to the Posterior Ligamentous Complex in AO Type A Fractures

    PubMed Central

    Schroeder, Gregory D.; Kepler, Christopher K.; Koerner, John D.; Oner, F. Cumhur; Fehlings, Michael G.; Aarabi, Bizhan; Dvorak, Marcel F.; Reinhold, Max; Kandziora, Frank; Bellabarba, Carlo; Chapman, Jens R.; Vialle, Luiz R.; Vaccaro, Alexander R.

    2015-01-01

    Study Design Survey of spine surgeons. Objective To determine the reliability with which international spine surgeons identify a posterior ligamentous complex (PLC) injury in a patient with a compression-type vertebral body fracture (type A). Methods A survey was sent to all AOSpine members from the six AO regions of the world. The survey consisted of 10 cases of type A fractures (2 subtype A1, 2 subtype A2, 3 subtype A3, and 3 subtype A4 fractures) with appropriate imaging (plain radiographs, computed tomography, and/or magnetic resonance imaging), and the respondent was asked to identify fractures with a PLC disruption, as well as to indicate if the integrity of the PLC would affect their treatment recommendation. Results Five hundred twenty-nine spine surgeons from all six AO regions of the world completed the survey. The overall interobserver reliability in determining the integrity of the PLC was slight (kappa = 0.11). No substantial regional or experiential difference was identified in determining PLC integrity or its absence; however, a regional difference was identified (p < 0.001) in how PLC integrity influenced the treatment of type A fractures. Conclusion The results of this survey indicate that there is only slight international reliability in determining the integrity of the PLC in type A fractures. Although the biomechanical importance of the PLC is not in doubt, the inability to reliably determine the integrity of the PLC may limit the utility of the M1 modifier in the AOSpine Thoracolumbar Spine Injury Classification System. PMID:26430591

  5. A Worldwide Analysis of the Reliability and Perceived Importance of an Injury to the Posterior Ligamentous Complex in AO Type A Fractures.

    PubMed

    Schroeder, Gregory D; Kepler, Christopher K; Koerner, John D; Oner, F Cumhur; Fehlings, Michael G; Aarabi, Bizhan; Dvorak, Marcel F; Reinhold, Max; Kandziora, Frank; Bellabarba, Carlo; Chapman, Jens R; Vialle, Luiz R; Vaccaro, Alexander R

    2015-10-01

    Study Design Survey of spine surgeons. Objective To determine the reliability with which international spine surgeons identify a posterior ligamentous complex (PLC) injury in a patient with a compression-type vertebral body fracture (type A). Methods A survey was sent to all AOSpine members from the six AO regions of the world. The survey consisted of 10 cases of type A fractures (2 subtype A1, 2 subtype A2, 3 subtype A3, and 3 subtype A4 fractures) with appropriate imaging (plain radiographs, computed tomography, and/or magnetic resonance imaging), and the respondent was asked to identify fractures with a PLC disruption, as well as to indicate if the integrity of the PLC would affect their treatment recommendation. Results Five hundred twenty-nine spine surgeons from all six AO regions of the world completed the survey. The overall interobserver reliability in determining the integrity of the PLC was slight (kappa = 0.11). No substantial regional or experiential difference was identified in determining PLC integrity or its absence; however, a regional difference was identified (p < 0.001) in how PLC integrity influenced the treatment of type A fractures. Conclusion The results of this survey indicate that there is only slight international reliability in determining the integrity of the PLC in type A fractures. Although the biomechanical importance of the PLC is not in doubt, the inability to reliably determine the integrity of the PLC may limit the utility of the M1 modifier in the AOSpine Thoracolumbar Spine Injury Classification System.

  6. Identification of Jasmonic Acid and Jasmonoyl-Isoleucine, and Characterization of AOS, AOC, OPR and JAR1 in the Model Lycophyte Selaginella moellendorffii.

    PubMed

    Pratiwi, Putri; Tanaka, Genta; Takahashi, Tomohiro; Xie, Xiaonan; Yoneyama, Koichi; Matsuura, Hideyuki; Takahashi, Kosaku

    2017-03-13

    Jasmonic acid (JA) is involved in a variety of physiological responses in seed plants. However, the detection and role of JA in lycophytes, a group of seedless vascular plants, have remained elusive until recently. This study provides the first evidence of 12-oxo-phytodienoic acid (OPDA), JA and jasmonoyl-isoleucine (JA-Ile) in the model lycophyte Selaginella moellendorffii. Mechanical wounding stimulated the accumulation of OPDA, JA and JA-Ile. These data were corroborated by the detection of enzymatically active allene oxide synthase (AOS), allene oxide cyclase (AOC), 12-oxo-phytodienoic acid reductase 3 (OPR3) and JA-Ile synthase (JAR1) in S. moellendorffii. SmAOS2 is involved in the first committed step of JA biosynthesis. SmAOC1 is a crucial enzyme for generating the basic structure of jasmonates and is actively involved in the formation of OPDA. SmOPR5, a functionally active OPR3-like enzyme, is also vital for the reduction of (+)-cis-OPDA, the only isomer of the JA precursor. The conjugation of JA to Ile by SmJAR1 demonstrates that S. moellendorffii produces JA-Ile. Thus, the four active enzymes have characteristics similar to those in seed plants. Wounding and JA treatment induced the expression of SmAOC1 and SmOPR5. Furthermore, JA inhibited the growth of shoots in S. moellendorffii, which suggests that JA functions as a signaling molecule in S. moellendorffii. This study proposes that JA evolved as a plant hormone for stress adaptation, beginning with the emergence of vascular plants.

  7. Insights on germinability and desiccation tolerance in developing neem seeds (Azadirachta indica): Role of AOS, antioxidative enzymes and dehydrin-like protein.

    PubMed

    Sahu, Balram; Sahu, Alok Kumar; Chennareddy, Srinivasa Rao; Soni, Avinash; Naithani, Subhash Chandra

    2017-03-01

    The germinability and desiccation tolerance (DT) in developing seed are regulated by cellular metabolism involving active oxygen species (AOS) and protective proteins during maturation drying. The aim of the present investigation was to unravel the functions of AOS (superoxide, H2O2 and OH-radical), antioxidative enzymes (SOD, CAT and APX) and dehydrin-like proteins in regulating the germinability and DT in undried and artificially desiccated developing neem seeds. Germination was first observed in seeds of 8 weeks after anthesis (waa) whereas DT was noticed from 9 waa. High levels of superoxide in undried and artificially desiccated seeds of 9 waa were rapidly declined up to 15 waa with simultaneous increase in levels of SOD (quantitative and isoenzymes) that dismutates superoxide with corresponding formation and accumulation of H2O2. Activities and isoenzymes of APX and CAT were promoted in seeds from 9 to 12 waa. Intensity of dehydrin-like proteins increased as development progressed in seeds with higher intensities in slow dried (SD) seeds. Desiccation modulated the metabolism for the acquisition of germinability and DT in the developing neem seeds from 8 to 15 waa by altering the levels of superoxide, H2O2 and OH-radical those possibly act as signalling molecules for reprogramming protective proteins. Desiccation mediated the expression of new bands of SOD and APX in undried as well as SD seeds during 9-12 waa but the bands were more intense in SD seeds. The superoxide and H2O2-regulated intensity of dehydrin-like protein in SD seeds further validated our conclusion.

  8. Spatial, temporal, and speciation variations of heavy metals in sediments of Nan'ao Island, a representative mariculture base in Guangdong coast, China.

    PubMed

    Gu, Yangguang; Yang, Yufeng; Lin, Qin; Li, Qusheng; Wang, Zenghuan; Wang, Xunuo

    2012-07-01

    Heavy metals in sediments from Baisha Bay, Nan'ao Island, one of Guangdong Province's largest mariculture bases in Southern China, were investigated. The results display that the concentrations of 6 heavy metals from surface sediments were 0.040-0.220 (Cd), 24.22-39.61 (Pb), 25.30-42.66 (Cr), 10.83-19.54 (Ni), 15.06-39.24 (Cu) and 55.12-141.73 mg kg(-1) (Zn), respectively. The highest concentrations and the greatest increasing rates of heavy metals were found in a sediment core in a fish cage culture area due to receiving sewage discharge, uneaten fish bait, and boat gasoline combustion. Cd was preferentially associated with the acid-soluble fraction and Pb mainly with the reducible fraction in surface sediments. Meanwhile, Cd and Pb displayed greatest labile fractions, indicating anthropogenic origin. A principal component analysis (PCA) revealed three groupings (Cd; Cr, Ni and Cu; Pb and Zn) that mainly result from different distributions of the metals in the various fractions. The ecological risk of the polluted sediments stemmed mainly from Cd, and from Pb and Cu to a lesser degree. It is suggested that the density of fish-stocking be controlled, periodic movement of rafts (cages) be introduced, and the total numbers of net-cages and human activities in the mariculture zones be restricted. in order to facilitate the recovery of the polluted sediment.

  9. Summary Report of the First International Symposium on Strain Gauge Balances and Workshop on AoA/Model Deformation Measurement Techniques

    NASA Technical Reports Server (NTRS)

    Tripp, John S.; Tcheng, Ping; Burner, Alpheus W.; Finley, Tom D.

    1999-01-01

    The first International Symposium on Strain Gauge Balances was sponsored under the auspices of the NASA Langley Research Center (LaRC), Hampton, Virginia during October 22-25, 1996. Held at the LaRC Reid Conference Center, the Symposium provided an open international forum for presentation, discussion, and exchange of technical information among wind tunnel test technique specialists and strain gauge balance designers. The Symposium also served to initiate organized professional activities among the participating and relevant international technical communities. The program included a panel discussion, technical paper sessions, tours of local facilities, and vendor exhibits. Over 130 delegates were in attendance from 15 countries. A steering committee was formed to plan a second international balance symposium tentatively scheduled to be hosted in the United Kingdom in 1998 or 1999. The Balance Symposium was followed by the half-day Workshop on Angle of Attack and Model Deformation on the afternoon of October 25. The thrust of the Workshop was to assess the state of the art in angle of attack (AoA) and model deformation measurement techniques and to discuss future developments.

  10. Soft X-ray spectrum of BL Lacertae object AO 0235+164 as a tracer of elemental abundances at z approximately 0.5

    NASA Technical Reports Server (NTRS)

    Madejski, Greg

    1994-01-01

    We report the soft X-ray spectrum of BL Lac object AO 0235+164, observed with the Einstein Observatory Imaging Proportional Counter (IPC). This object (z = 0.94) has an intervening galaxy (or a protogalactic disk) at z = 0.524 present in the line of sight, producing both radio and optical absorption lines in the background BL Lac continuum. The X-ray spectrum exhibits a substantial soft X-ray cutoff, corresponding to several times that expected from our own Galaxy; we interpret that excess cutoff as due to the intervening galaxy. The comparison of the hydrogen column density inferred from the 21 cm radio data and the X-ray absorption allows, in principle, the determination of the elemental abundances in the intervening galaxy. However, the uncertainties in both the H I spin temperature and X-ray spectral parameters only loosely restrict these abundances to be 2 +/- 1 solar, which even at the lower limit appears higher than that inferred from studies of samples of optical absoprtion-line systems.

  11. NEW EXTINCTION AND MASS ESTIMATES FROM OPTICAL PHOTOMETRY OF THE VERY LOW MASS BROWN DWARF COMPANION CT CHAMAELEONTIS B WITH THE MAGELLAN AO SYSTEM

    SciTech Connect

    Wu, Ya-Lin; Close, Laird M.; Males, Jared R.; Morzinski, Katie M.; Follette, Katherine B.; Bailey, Vanessa; Rodigas, Timothy J.; Hinz, Philip; Barman, Travis S.; Puglisi, Alfio; Xompero, Marco; Briguglio, Runa

    2015-03-01

    We used the Magellan adaptive optics system and its VisAO CCD camera to image the young low mass brown dwarf companion CT Chamaeleontis B for the first time at visible wavelengths. We detect it at r', i', z', and Y{sub S}. With our new photometry and T {sub eff} ∼ 2500 K derived from the shape of its K-band spectrum, we find that CT Cha B has A{sub V} = 3.4 ± 1.1 mag, and a mass of 14-24 M{sub J} according to the DUSTY evolutionary tracks and its 1-5 Myr age. The overluminosity of our r' detection indicates that the companion has significant Hα emission and a mass accretion rate ∼6 × 10{sup –10} M {sub ☉} yr{sup –1}, similar to some substellar companions. Proper motion analysis shows that another point source within 2'' of CT Cha A is not physical. This paper demonstrates how visible wavelength adaptive optics photometry (r', i', z', Y{sub S}) allows for a better estimate of extinction, luminosity, and mass accretion rate of young substellar companions.

  12. [Heavy metal accumulation during last hundred years and its assessment of potential ecological risk in the coastal wetland of Qi'ao Island, Pearl River Estuary of China].

    PubMed

    Wang, Ai-jun; Ye, Xiang; Li, Tuan-jie; Huang, Cai-bin

    2011-05-01

    The processes of fine sediment transport and deposition can record some relative anthropogenic information in estuarine environments. Grain size analysis of the sediment core collected from coastal wetland of Qi'ao Island in the Pearl River Estuary of China show that the sediment is mainly composed by clayey silt, and the mean grain size, contents of clay and silt increase upward gradually. Chronology analysis show that the sedimentation rate above 59 cm is about 4.15 cm x a(-1), and 0.97 cm x a(-1) beneath 59 cm. Heavy metal analysis indicate that the contents of the each heavy metal increased slowly with a slight intensity of potential ecological risk; however, from 1966 to 1992, the heavy metal contents increased obviously because of the quick social-economy development around the Pearl River Estuary area, and the order of polluting degree of these heavy metals in core sediment is Cd > Ni > Pb > Cu > Cr > Zn. The potential ecological risk intensity of Cd increased from slight risk before 1966 to strong risk since 1992, and the potential ecological risk intensities other heavy metal are slight risk; the potential ecological risk index is weak level. The variations of core sediment heavy metal contents and its ecological risk assessments along the vertical profile reveal the interaction processes and intent of anthropogenic influences from the areas around the Pearl River Estuary and the catchments.

  13. Traditional healing practices originating in Aruba, Bonaire, and Curaçao: A review of the literature on psychiatry and Brua.

    PubMed

    Blom, Jan Dirk; Poulina, Igmar T; van Gellecum, Trevor L; Hoek, Hans W

    2015-12-01

    Brua is an Afro-Caribbean religion and healing tradition from the southern part of the former Netherlands Antilles. Like other Caribbean healing traditions, it plays a significant role in shaping how individuals experience and express disorders which Western health professionals consider to require psychiatric care. Because little has been published on Brua, and because patients from Aruba, Bonaire, and Curaçao are often reluctant to discuss their commitment to this tradition, they are often misdiagnosed and either over- or undertreated by biomedically trained health professionals. The present paper provides a review of the literature on Brua and its relation to psychiatry. A systematic search was carried out in PubMed, the Ovid database, Google Scholar, and the historical literature. Our search yielded 35 texts on Brua, including three peer-reviewed scientific papers and eight academic theses. From those texts Brua emerges as a holistic patchwork of creolized beliefs and practices which are considered to be both cause and remedy for a wide variety of ailments. Despite the fact that tension between the Brua discourse and Western-oriented psychiatric practice is significant, adherence to Brua does not seem to cause much patient delay in help-seeking. However, belief in Brua as a possible source of mental and physical complaints, as well as patients' frequent recourse to Brua practices, including the use of hallucinogens, may affect the diagnosis and treatment of mental disorders.

  14. On the Location of the gamma-Ray Outburst Emission in the BL Lacertae Object AO 0235 + 164 Through Observations Across the Electromagnetic Spectrum

    NASA Technical Reports Server (NTRS)

    Agudo, Ivan; Marscher, Alan P.; Jorstad, Svetlana G.; Larionov, Valeri M.; Gomez, Jose L.; Laehteenmaeki, Anne; Smith, Paul S.; Nilsson, Kari; Readhead, Anthony C. S.; Aller, Margo F.; Heidt, Jochien; Gurwell, Mark; Thum, Clemens; Wehrle, Ann E.; Nikolashvili, Maria G.; Aller, Hugh D.; Benitez, Erika; Blinov, Dmitriy A.; Hagen-Thorn, Vladimir A.; Hiriart, David; Jannuzi, Buell T.; Joshi, Manasvita; Kimeridze, Givi N.; Kurtanidze, Omar M.; Kurtanidze, Sofia O.

    2011-01-01

    We present observations of a major outburst at centimeter, millimeter, optical, X-ray, and gamma-ray wavelengths of the BL Lacertae object AO 0235+164. We analyze the timing of multi-waveband variations in the flux and linear polarization, as well as changes in Very Long Baseline Array images at A = 7 mm with approx.0.15 milliarcsec resolution. The association of the events at different wavebands is confirmed at high statistical significance by probability arguments and Monte Carlo simulations. A series of sharp peaks in optical linear polarization, as well as a pronounced maximum in the 7 mm polarization of a superluminal jet knot, indicate rapid fluctuations in the degree of ordering of the magnetic field. These results lead us to conclude that the outburst occurred in the jet both in the quasi-stationary "core" and in the superluminal knot, both parsecs downstream of the supermassive black hole. We interpret the outburst as a consequence of the propagation of a disturbance, elongated along the line of sight by light-travel time delays, that passes through a standing recollimation shock in the core and propagates down the jet to create the superluminal knot. The multi-wavelength light curves vary together on long timescales (months/ years), but the correspondence is poorer on shorter timescales. This, as well as the variability of the polarization and the dual location of the outburst, agrees with the expectations of a multi-zone emission model in which turbulence plays a major role in modulating the synchrotron and inverse Compton fluxes.

  15. Aquecimento alfvênico viscoso-resistivo em discos de acresção ao redor de estrelas T Tauri clássicas

    NASA Astrophysics Data System (ADS)

    Santana, W. M.; Vasconcelos, M. J.

    2003-08-01

    Com a crescente disponibilidade de dados observacionais sobre estrelas T Tauri, a busca por modelos mais precisos vem se tornando cada vez maior. Estes modelos devem explicar, entre outras coisas, o mecanismo dissipativo responsável pelo transporte de momento angular no disco de acresção que acredita-se, circunda estas estrelas. O mecanismo mais viável, do ponto de vista teórico, é uma instabilidade MHD conhecida como "instabilidade magnetorotacional ou Balbus-Hawley" (IBH). Esta instabilidade veio mostrar que o campo magnético desempenha um papel importante na evolução destes objetos mas requer, no entanto, um acoplamento mínimo entre o gás e o campo magnético no disco que não é atingido para os valores de temperatura obtidos do modelo padrão. Contudo, alguns mecanismos de aquecimento para o disco precisam ser examinados. Neste trabalho, propomos a dissipação de ondas Alfvén como uma fonte de aquecimento para o disco. Se o gás apresentar uma condutividade elétrica finita e viscosidade, teremos um tipo de amortecimento para as ondas denominado amortecimento viscoso-resistivo que será aqui considerado. Este mecanismo é aplicado ao modelo de disco em camadas. Calculam-se as taxas de aquecimento Alfvênico, a temperatura efetiva do disco bem como as taxas de ionização decorrentes deste aquecimento e do aquecimento gerado pela absorção de raios cósmicos. Comparações com os dados observacionais de Kitamura et. al. (2001) são efetuadas, ressaltando-se os pontos comuns entre suas observações e nossos dados teóricos.

  16. Using UPLC-QTOF-MS to analyze the chemical changes between traditional and dispensing granule decoctions of San-Ao-Tang.

    PubMed

    Ma, Chunhua; Qian, Yefei; Fan, Xinsheng; Shang, ErXin; Yao, Xin; Ma, Shiping

    2014-04-01

    In the present study, a chemical profiling approach based on ultra-performance liquid chromatography coupled with photodiode array detection and time-of-flight mass spectrometry (UPLC-PDA-TOF-MS) was proposed to rapidly evaluate the chemical consistency between traditional and dispensing granule decoctions of traditional medicine combinatorial formulae and validated using San-Ao-Tang (SAT) as a model combinatorial formula. SAT is an effective traditional Chinese medicine, which is usually used in treating asthma and other diseases of the respiratory system. Two decoctions were prepared: traditional decoction, which is a water extract of three mixed constituent herbs of SAT; and dispensing granule decoction, which is a mixed water extract of each individual herb of SAT. Batches of these two decoction samples were subjected to UPLC-PDA-TOF-MS analysis and the data sets of t(R)-m/z pairs, ion intensities and sample codes were processed with supervised orthogonal partial least squared discriminant analysis to holistically compare their differences. Once a clear classification trend was found in the score plot, further statistics were performed to generate points at the two ends of S, and the components that correlated to these ions were regarded as the most changed components during decoction of the combinatorial formula. The changed components were identified by comparing the mass/ultraviolet spectra and retention times with those of reference compounds and/or tentatively assigned by matching empirical molecular formulae with those of the known compounds published in the literature. Using the proposed approach, global chemical differences were found between traditional and dispensing granule decoctions, like ephedrine, pseudoephedrine, norpseudoephedrine, licorice saponine H2, licorice saponine G2 and amygdalin.

  17. MOSE: a feasibility study for optical turbulence forecast with the Meso-Nh mesoscale model to support AO facilities at ESO sites (Paranal and Armazones)

    NASA Astrophysics Data System (ADS)

    Masciadri, Elena; Lascaux, Franck

    2012-07-01

    We present very encouraging preliminary results obtained in the context of the MOSE project, an on-going study aiming at investigating the feasibility of the forecast of the optical turbulence and meteorological parameters (in the free atmosphere as well as in the boundary and surface layer) at Cerro Paranal (site of the Very Large Telescope - VLT) and Cerro Armazones (site of the European Extremely Large Telescope - E-ELT), both in Chile. The study employs the Meso-Nh atmospheric mesoscale model and aims at supplying a tool for optical turbulence forecasts to support the scheduling of the scientific programs and the use of AO facilities at the VLT and the E-ELT. In this study we take advantage of the huge amount of measurements performed so far at Paranal and Armazones by ESO and the TMT consortium in the context of the site selection for the E-ELT and the TMT to constraint / validate the model. A detailed analysis of the model performances in reproducing the atmospheric parameters (T, V, p, H, ...) near the ground as well as in the free atmosphere, is critical and fundamental because the optical turbulence depends on most of these parameters. This approach permits us to provide an exhaustive and complete analysis of the model performances and to better define the model operational application. This also helps us to identify the sources of discrepancies with optical turbulence measurements (when they appear) and to discriminate between different origins of the problem: model parameterization, initial conditions, ... Preliminary results indicate a great accuracy of the model in reproducing most of the main meteorological parameters in statistical terms as well as in each individual night in the free atmosphere and in proximity of the surface. The study is co-funded by ESO and INAF-Arcetri (Italy).

  18. Studies of the Canadian Arctic Archipelago water transport and its relationship to basin-local forcings: Results from AO-FVCOM

    NASA Astrophysics Data System (ADS)

    Zhang, Yu; Chen, Changsheng; Beardsley, Robert C.; Gao, Guoping; Lai, Zhigang; Curry, Beth; Lee, Craig M.; Lin, Huichan; Qi, Jianhua; Xu, Qichun

    2016-06-01

    A high-resolution (up to 2 km), unstructured-grid, fully coupled Arctic sea ice-ocean Finite-Volume Community Ocean Model (AO-FVCOM) was employed to simulate the flow and transport through the Canadian Arctic Archipelago (CAA) over the period 1978-2013. The model-simulated CAA outflow flux was in reasonable agreement with the flux estimated based on measurements across Davis Strait, Nares Strait, Lancaster Sound, and Jones Sounds. The model was capable of reproducing the observed interannual variability in Davis Strait and Lancaster Sound. The simulated CAA outflow transport was highly correlated with the along-strait and cross-strait sea surface height (SSH) difference. Compared with the wind forcing, the sea level pressure (SLP) played a dominant role in establishing the SSH difference and the correlation of the CAA outflow with the cross-strait SSH difference can be explained by a simple geostrophic balance. The change in the simulated CAA outflow transport through Davis Strait showed a negative correlation with the net flux through Fram Strait. This correlation was related to the variation of the spatial distribution and intensity of the slope current over the Beaufort Sea and Greenland shelves. The different basin-scale surface forcings can increase the model uncertainty in the CAA outflow flux up to 15%. The daily adjustment of the model elevation to the satellite-derived SSH in the North Atlantic region outside Fram Strait could produce a larger North Atlantic inflow through west Svalbard and weaken the outflow from the Arctic Ocean through east Greenland.

  19. Analysis of LDEF experiment AO187-2 chemical and isotopic measurements of micrometeoroids by secondary ion mass spectrometry. Final report

    SciTech Connect

    Zinner, E.

    1995-11-01

    Experiment AO187-2, that was flown on board the Long Duration Exposure Facility (LDEF), was designed to measure the chemical and isotopic compositions of interplanetary dust impinging on the spacecraft from outer space. Information on the nature and composition of orbital debris was also anticipated. The spacecraft maintained a constant orientation with respect to its velocity vector thereby defining leading and trailing edges that faced respectively into and away from the direction of motion. Arrays of individual capture cells each 80.8 sq cm in size and totaling 237 in number were exposed on both the leading and trailing edges of LDEF. Each cell consisted of a pure Ge target surface slightly separated from a thin (2.5 micrometers) metallized plastic `entrance foil.` The basic concept was that incoming projectiles would penetrate the foil, strike the Ge target plate at high velocity producing a vapor-liquid cloud that would re-deposit material on the underside of the plastic foil. This material would then be analyzed using the sensitive surface analysis technique of Secondary Ion Mass Spectrometry (SIMS). In practice, most of the plastic entrance foils failed during the extended period of orbital exposure probably due to a combination of UV embrittlement, large densities of impact events and (for the leading edge) the effects of atomic oxygen erosion in orbit. However the foils failed gradually and most remained in place on the capture cells for a significant fraction of the duration of the flight. Because most of the impactors were small (less than 10 micrometers) they were heated and dispersed in traversing the entrance foils producing clouds of molten droplets and vapor that produced easily identifiable `extended impacts` on the Ge target plates.

  20. [Alimentary, nutritional and health aspects of elderly women in attendance at the Núcleo de Atenção ao Idoso, Recife/2005].

    PubMed

    Amado, Tânia Campos Fell; Arruda, Ilma Kruze Grande de; Ferreira, Rogério Anderson Rodrigues

    2007-12-01

    Aging has become a worldwide problem. In order to identify food, nutritional and health aspects of elderly women, a across-sectional study was carried out in 2005 with 106 women over 60 years of age cared for at Núcleo de Atenção ao idoso-NAI at Federal University of Pernambuco. Clinical and social-demographic variables, along with the nutritional status by BMI (OMS and Lipschtz) were assessed, and the frequency of food intake according to food groups. The results disclosed that 38% of the elderly were pre-obese (WHO) and 47.2% were overweight (Lipschitz). As for blood pressure (BP) 69% was found to be hypertensive and 31% normotensive. The BMI mean of hypertensive and normal elderly women was statistically significant (p=0.027). Cereal and bread groups were reported to have been the highest consumption on a daily basis by the elderly women, 89% and 82% respectively. Legumes were present in 53% of the women's meals followed by vegetables with 61% and fruits with 66%. Concerning water intake, 51.9% stated to have ingested one to four glasses of water daily. There was a positive correlation between BMI and systolic (SP) and diastolic pressure (DP) (p<0.001). SP and DP levels showed no correlation with the food intake studied. The results are indicative of an overweight and not conscientious population as regards adequate food intake and point to the necessity of more effective actions in control and/or prevention, particularly for those still young.

  1. Prevalence of Pediculus humanus capitis among school girls of Chuang-Wei and Nan-Ao Districts in I-Lan County and Man-Chow District in Ping-Tung County, Taiwan.

    PubMed

    Chao, D; Liu, H Y; Fan, P C

    1981-03-01

    By using the naked eye examination and comb method, a field survey and combing collection of head louse (Pediculus humanus capitis) among school girls in three different area (Man-Chow, Nan-Ao and Chuang-Wei) of Taiwan were performed from July 1979 to February, 1980. The general infestation rate of head louse was 39.8% (or 998/2,509). In the primary schools, comparatively, the rate at Man-Chow (66.7%) was highest, the next at Nan-Ao (55.4%) and the lowest at Chuang-Wei (39.4%). While in the junior high schools, the rate was apparently higher at Nan-Ao (38.4%) than that at Man-Chow (15.6%) and Chang-Wei (12.0%). The highest rate in the primary schools was found in 3rd graders except at Chuang-Wei in 5th graders. The corresponding figure in the junior high schools was found in 1st graders except at Nan-Ao in 2nd graders. Of 774 infested girls studied, according to the number of lice per infested girl, the percentages of infestation in the 5 groups were: the very light (nits only) 54.5, light (1-10) 38.5, moderate (11-50) 6.5, heavy (51-100) 0.4 and very heavy (over 100) 0.1 respectively. Of 2,178 head lice examined, 53.0% was nymphs; 28.7% females; 18.2% males. The average number of head louse in each infested girl 6.2.

  2. Steppingstones to the implementation of an inhospital fracture and dislocation registry using the AO/OTA classification: compliance, completeness and commitment

    PubMed Central

    2010-01-01

    Background Musculoskeletal trauma represents a considerable global health burden, however reliable population-based incidence data are scarce. A fracture and dislocation registry was established within a well-defined population. An audit of the establishment process, feasibility of the registry work and report of the collected data is given. Methods Demographic data, fracture type and location, mode of treatment, and the reasons for the secondary procedures were collected and scored using recognized systems, such as the AO/OTA classification and the Gustilo-Anderson classification for open fractures. The reporting was done in the operation planning program by the involved orthopaedic surgeon. Both inpatient and day-case procedures were collected. Data were collected prospectively from 2006 until 2010. Compliance among the surgeons and completeness and accuracy of the data was continuously assured by an orthopaedic surgeon. Results During the study period, 39 orthopaedic surgeons were involved in the recording of a total of 8,188 procedures, consisting of primary treatment of 4,986 long bone fractures, 467 non long bone fractures, 123 dislocations and 2,612 secondary treatments. In the study period 532 fractures or dislocations were treated at least once for one or more serious complications. For the index year of 2009, a total of 5710 fractures or dislocations were treated in the emergency department or hospitalized, of which the 1594 (28%) were treated at the inpatient or day-case operation rooms, thus registered in the FDR. Quality assurance, educational incentives and continuous feedback between coders and controller in the integrated electronic system are available and used through the features of the electronic database. Conclusions Implementing an integrated registry of fractures and dislocations with the electronic hospital system has been possible despite several users involved. The electronic system and the data controller provide for completeness and

  3. Application of 'Six Sigma{sup TM}' and 'Design of Experiment' for Cementation - Recipe Development for Evaporator Concentrate for NPP Ling AO, Phase II (China) - 12555

    SciTech Connect

    Fehrmann, Henning; Perdue, Robert

    2012-07-01

    Cementation of radioactive waste is a common technology. The waste is mixed with cement and water and forms a stable, solid block. The physical properties like compression strength or low leach ability depends strongly on the cement recipe. Due to the fact that this waste cement mixture has to fulfill special requirements, a recipe development is necessary. The Six Sigma{sup TM}' DMAIC methodology, together with the Design of experiment (DoE) approach, was employed to optimize the process of a recipe development for cementation at the Ling Ao nuclear power plant (NPP) in China. The DMAIC offers a structured, systematical and traceable process to derive test parameters. The DoE test plans and statistical analysis is efficient regarding the amount of test runs and the benefit gain by getting a transfer function. A transfer function enables simulation which is useful to optimize the later process and being responsive to changes. The DoE method was successfully applied for developing a cementation recipe for both evaporator concentrate and resin waste in the plant. The key input parameters were determined, evaluated and the control of these parameters were included into the design. The applied Six Sigma{sup TM} tools can help to organize the thinking during the engineering process. Data are organized and clearly presented. Various variables can be limited to the most important ones. The Six Sigma{sup TM} tools help to make the thinking and decision process trace able. The tools can help to make data driven decisions (e.g. C and E Matrix). But the tools are not the only golden way. Results from scoring tools like the C and E Matrix need close review before using them. The DoE is an effective tool for generating test plans. DoE can be used with a small number of tests runs, but gives a valuable result from an engineering perspective in terms of a transfer function. The DoE prediction results, however, are only valid in the tested area. So a careful selection of input

  4. OGLE-2012-BLG-0563Lb: A Saturn-mass Planet around an M Dwarf with the Mass Constrained by Subaru AO Imaging

    NASA Astrophysics Data System (ADS)

    Fukui, A.; Gould, A.; Sumi, T.; Bennett, D. P.; Bond, I. A.; Han, C.; Suzuki, D.; Beaulieu, J.-P.; Batista, V.; Udalski, A.; Street, R. A.; Tsapras, Y.; Hundertmark, M.; Abe, F.; Bhattacharya, A.; Freeman, M.; Itow, Y.; Ling, C. H.; Koshimoto, N.; Masuda, K.; Matsubara, Y.; Muraki, Y.; Ohnishi, K.; Philpott, L. C.; Rattenbury, N.; Saito, T.; Sullivan, D. J.; Tristram, P. J.; Yonehara, A.; MOA Collaboration; Choi, J.-Y.; Christie, G. W.; DePoy, D. L.; Dong, Subo; Drummond, J.; Gaudi, B. S.; Hwang, K.-H.; Kavka, A.; Lee, C.-U.; McCormick, J.; Natusch, T.; Ngan, H.; Park, H.; Pogge, R. W.; Shin, I.-G.; Tan, T.-G.; Yee, J. C.; μFUN Collaboration; Szymański, M. K.; Pietrzyński, G.; Soszyński, I.; Poleski, R.; Kozłowski, S.; Pietrukowicz, P.; Ulaczyk, K.; Wyrzykowski, Ł.; OGLE Collaboration; Bramich, D. M.; Browne, P.; Dominik, M.; Horne, K.; Ipatov, S.; Kains, N.; Snodgrass, C.; Steele, I. A.; RoboNet Collaboration

    2015-08-01

    We report the discovery of a microlensing exoplanet OGLE-2012-BLG-0563Lb with the planet-star mass ratio of ˜ 1× {10}-3. Intensive photometric observations of a high-magnification microlensing event allow us to detect a clear signal of the planet. Although no parallax signal is detected in the light curve, we instead succeed at detecting the flux from the host star in high-resolution JHK‧-band images obtained by the Subaru/AO188 and Infrared Camera and Spectrograph instruments, allowing us to constrain the absolute physical parameters of the planetary system. With the help of spectroscopic information about the source star obtained during the high-magnification state by Bensby et al., we find that the lens system is located at 1.3{}-0.8+0.6 kpc from us, and consists of an M dwarf (0.34 {}-0.20+0.12M{}⊙ ) orbited by a Saturn-mass planet (0.39 {}-0.23+0.14MJup) at the projected separation of 0.74{}-0.42+0.26 AU (close model) or 4.3{}-2.5+1.5 AU (wide model). The probability of contamination in the host star’s flux, which would reduce the masses by a factor of up to three, is estimated to be 17%. This possibility can be tested by future high-resolution imaging. We also estimate the (J-{K}{{s}}) and (H-{K}{{s}}) colors of the host star, which are marginally consistent with a low metallicity mid-to-early M dwarf, although further observations are required for the metallicity to be conclusive. This is the fifth sub-Jupiter-mass (0.2\\lt {m}{{p}}/{M}{Jup}\\lt 1) microlensing planet around an M dwarf with the mass well constrained. The relatively rich harvest of sub-Jupiters around M dwarfs is contrasted with a possible paucity of ˜1-2 Jupiter-mass planets around the same type of star, which can be explained by the planetary formation process in the core-accretion scheme.

  5. Estimation from incomplete multinomial data. Ph.D. Thesis - Harvard Univ.

    NASA Technical Reports Server (NTRS)

    Credeur, K. R.

    1978-01-01

    The vector of multinomial cell probabilities was estimated from incomplete data, incomplete in that it contains partially classified observations. Each such partially classified observation was observed to fall in one of two or more selected categories but was not classified further into a single category. The data were assumed to be incomplete at random. The estimation criterion was minimization of risk for quadratic loss. The estimators were the classical maximum likelihood estimate, the Bayesian posterior mode, and the posterior mean. An approximation was developed for the posterior mean. The Dirichlet, the conjugate prior for the multinomial distribution, was assumed for the prior distribution.

  6. A new approach to telemetry data processing. Ph.D. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Broglio, C. J.

    1973-01-01

    An approach for a preprocessing system for telemetry data processing was developed. The philosophy of the approach is the development of a preprocessing system to interface with the main processor and relieve it of the burden of stripping information from a telemetry data stream. To accomplish this task, a telemetry preprocessing language was developed. Also, a hardware device for implementing the operation of this language was designed using a cellular logic module concept. In the development of the hardware device and the cellular logic module, a distributed form of control was implemented. This is accomplished by a technique of one-to-one intermodule communications and a set of privileged communication operations. By transferring this control state from module to module, the control function is dispersed through the system. A compiler for translating the preprocessing language statements into an operations table for the hardware device was also developed. Finally, to complete the system design and verify it, a simulator for the collular logic module was written using the APL/360 system.

  7. Resonance tube hazards in oxygen systems. Ph.D. Thesis - Toledo Univ., 1975

    NASA Technical Reports Server (NTRS)

    Phillips, B. R.

    1982-01-01

    An experimental and analytical program was carried out to determine whether fluid dynamic oscillations could create a hazard in gaseous oxygen flow systems. The particular fluid dynamic oscillation studied was the resonance tube phenomena as it was excited in a tee-shaped configuration characteristic of configurations found in many industrial high pressure gas flow systems. The types of hazards that could be caused by the oscillations were direct heating and ignition of the piping system by the gas, the greatly augmented heating that could occur if inert contaminants were present, and the ignition of metallic contaminants. Asbestos was used as the inert contaminant; titanium, aluminum, magnesium and steel were chosen as ignitable metallic contaminants. The oscillations in the tee-shaped configuration were compared to oscillations driven by choked convergent nozzles and were found to differ markedly. Temperature generated at the end or base of the resonance tube exceeded 1089 K for both gaseous oxygen and nitrogen and reached 1645 K when asbestos was added. Aluminum in both powder and fiber form was readily ignited within the resonance tube when the supply pressures were less than 8270 kPa whereas at higher supply pressures the mixture exploded with enough violence to destory the apparatus in less than 10 sec. In addition to aluminum, magnesium, and titanium, samples of 400 series stainless steels were also ignited within the resonance tube. The ignition occurred within a few seconds after the oxygen flow began.

  8. Robust fault diagnosis of physical systems in operation. Ph.D. Thesis - Rutgers - The State Univ.

    NASA Technical Reports Server (NTRS)

    Abbott, Kathy Hamilton

    1991-01-01

    Ideas are presented and demonstrated for improved robustness in diagnostic problem solving of complex physical systems in operation, or operative diagnosis. The first idea is that graceful degradation can be viewed as reasoning at higher levels of abstraction whenever the more detailed levels proved to be incomplete or inadequate. A form of abstraction is defined that applies this view to the problem of diagnosis. In this form of abstraction, named status abstraction, two levels are defined. The lower level of abstraction corresponds to the level of detail at which most current knowledge-based diagnosis systems reason. At the higher level, a graph representation is presented that describes the real-world physical system. An incremental, constructive approach to manipulating this graph representation is demonstrated that supports certain characteristics of operative diagnosis. The suitability of this constructive approach is shown for diagnosing fault propagation behavior over time, and for sometimes diagnosing systems with feedback. A way is shown to represent different semantics in the same type of graph representation to characterize different types of fault propagation behavior. An approach is demonstrated that threats these different behaviors as different fault classes, and the approach moves to other classes when previous classes fail to generate suitable hypotheses. These ideas are implemented in a computer program named Draphys (Diagnostic Reasoning About Physical Systems) and demonstrated for the domain of inflight aircraft subsystems, specifically a propulsion system (containing two turbofan systems and a fuel system) and hydraulic subsystem.

  9. On the Physical Environment in the Galactic Nuclei. Ph.D. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Beall, J. H.

    1979-01-01

    Galactic nuclei and quasars emit radiation over the entire electromagnetic spectrum. This suggests that concurrent observations over a wide frequency range may provide useful information in determining appropriate models for the physical environment in which the radiation is produced. In conjunction with observations by the high energy spectrometer on OSO-8, four sources have been studied in this manner; the nucleus of the elliptical galaxy, Centaurus A (NGG 5128); the quasar, 30273; the Seyfert galaxy, NGC 4151 and the nucleus of the Milky Way (GCX). Concurrent observations are used to construct the composite spectra (from radio to X-ray) for Cen A and NGC 4151 while the composite spectra of 30273 and GCX are derived from the OSO-8 data and from other observers. A skymap technique used to analyze observations of the galactic center region yielded data consistent with a significant, hard X-ray source at the radio and infrared position of the nucleus of the Milky Way. A theoretical analysis of the temporal variability of the Cen A data is undertaken and its implications discussed. Similarities between the composite spectra of the observed sources suggest that radio-bright and radio-quiet quasars may represent the emission from galactic nuclei with elliptical and Seyfert-like morphologies, respectively.

  10. Univ. of New Haven Student Selected for EPA Fellowships to Support Next Generation of Environmental Scientists

    EPA Pesticide Factsheets

    A student at University of New Haven in West Haven was among five New England students and 34 students nationwide studying environmental science and related fields of study at universities and colleges across the nation awarded grants to work at the US Env

  11. Compressible flows with periodic vortical disturbances around lifting airfoils. Ph.D. Thesis - Notre Dame Univ.

    NASA Technical Reports Server (NTRS)

    Scott, James R.

    1991-01-01

    A numerical method is developed for solving periodic, three-dimensional, vortical flows around lifting airfoils in subsonic flow. The first-order method that is presented fully accounts for the distortion effects of the nonuniform mean flow on the convected upstream vortical disturbances. The unsteady velocity is split into a vortical component which is a known function of the upstream flow conditions and the Lagrangian coordinates of the mean flow, and an irrotational field whose potential satisfies a nonconstant-coefficient, inhomogeneous, convective wave equation. Using an elliptic coordinate transformation, the unsteady boundary value problem is solved in the frequency domain on grids which are determined as a function of the Mach number and reduced frequency. The numerical scheme is validated through extensive comparisons with known solutions to unsteady vortical flow problems. In general, it is seen that the agreement between the numerical and analytical results is very good for reduced frequencies ranging from 0 to 4, and for Mach numbers ranging from .1 to .8. Numerical results are also presented for a wide variety of flow configurations for the purpose of determining the effects of airfoil thickness, angle of attack, camber, and Mach number on the unsteady lift and moment of airfoils subjected to periodic vortical gusts. It is seen that each of these parameters can have a significant effect on the unsteady airfoil response to the incident disturbances, and that the effect depends strongly upon the reduced frequency and the dimensionality of the gust. For a one-dimensional (transverse) or two-dimensional (transverse and longitudinal) gust, the results indicate that airfoil thickness increases the unsteady lift and moment at the low reduced frequencies but decreases it at the high reduced frequencies. The results show that an increase in airfoil Mach number leads to a significant increase in the unsteady lift and moment for the low reduced frequencies, but a significant decrease for the high reduced frequencies.

  12. A numerical study of fundamental shock noise mechanisms. Ph.D. Thesis - Cornell Univ.

    NASA Technical Reports Server (NTRS)

    Meadows, Kristine R.

    1995-01-01

    The results of this thesis demonstrate that direct numerical simulation can predict sound generation in unsteady aerodynamic flows containing shock waves. Shock waves can be significant sources of sound in high speed jet flows, on helicopter blades, and in supersonic combustion inlets. Direct computation of sound permits the prediction of noise levels in the preliminary design stage and can be used as a tool to focus experimental studies, thereby reducing cost and increasing the probability of a successfully quiet product in less time. This thesis reveals and investigates two mechanisms fundamental to sound generation by shocked flows: shock motion and shock deformation. Shock motion is modeled by the interaction of a sound wave with a shock. During the interaction, the shock wave begins to move and the sound pressure is amplified as the wave passes through the shock. The numerical approach presented in this thesis is validated by the comparison of results obtained in a quasi-one dimensional simulation with linear theory. Analysis of the perturbation energy demonstrated for the first time that acoustic energy is generated by the interaction. Shock deformation is investigated by the numerical simulation of a ring vortex interacting with a shock. This interaction models the passage of turbulent structures through the shock wave. The simulation demonstrates that both acoustic waves and contact surfaces are generated downstream during the interaction. Analysis demonstrates that the acoustic wave spreads cylindrically, that the sound intensity is highly directional, and that the sound pressure level increases significantly with increasing shock strength. The effect of shock strength on sound pressure level is consistent with experimental observations of shock noise, indicating that the interaction of a ring vortex with a shock wave correctly models a dominant mechanism of shock noise generation.

  13. Physics of Nonmagnetic Relativistic Thermal Plasmas. Ph.D. Thesis - Calif. Univ., San Diego

    NASA Technical Reports Server (NTRS)

    Dermer, C. D.

    1984-01-01

    A detailed treatment of the kinematics of relativistic systems of particles and photons is presented. In the case of a relativistic Maxwell-Boltzmann distribution of particles, the reaction rate and luminosity are written as single integrals over the invariant cross section, and the production spectrum is written as a double integral over the cross section differential in the energy of the produced particles (or photons) in the center-of-momentum system of two colliding particles. The results are applied to the calculation of the annihilation spectrum of a thermal electron-positron plasma, confirming previous numerical and analytic results. Relativistic thermal electron-ion and electron-electron bremsstrahlung are calculated exactly to lowest order, and relativistic thermal electron-positron bremsstrahlung is calculated in an approximate fashion. An approximate treatment of relativistic Comptonization is developed. The question of thermalization of a relativistic plasma is considered. A formula for the energy loss or exchange rate from the interaction of two relativistic Maxwell-Boltzmann plasmas at different temperatures is derived. Application to a stable, uniform, nonmagnetic relativistic thermal plasma is made. Comparison is made with other studies.

  14. Research program in elementary particle theory. Progress report for period ending June 30, 1980. [Syracuse Univ

    SciTech Connect

    Not Available

    1980-01-01

    The High Energy Theory Group at Syracuse conducted basic research in several areas of current interest. A great deal of progress was made in the understanding of systems with unusual topological properties. A variational formulation of the equations that govern spinning particles in general relativity was accomplished. Perturbative as well as nonperturbative properties (incorporated in an effective Lagrangian) of quantum chromodynamics aspects were investigated. The question concerning gauge fixing in non-Abelian gauge theories was studied. Several new phenomenological aspects of unified electroweak interactions were explored with the object of finding experimental tests for models other than the currently accepted Salam-Weinberg theory. A unified electroweak model based on the group (SU(2) x U(1)) x U'(1) was investigated to account for the repeated fermionic generations and to incorporate CP violations and explain the CP violation as well as the Cabibbo-like angles in terms of the quark masses. A unified theory for all interactions (with the exception of gravitational interactions) based on the group SU(5) x SU(5) was proposed. Finally, axially symmetric multi-instanton solutions were shown to be generated from a set of conformal mappings. The work performed is described briefly; references are given.

  15. Free-Swinging Failure Tolerance for Robotic Manipulators. Degree awarded by Purdue Univ.

    NASA Technical Reports Server (NTRS)

    English, James

    1997-01-01

    Under this GSRP fellowship, software-based failure-tolerance techniques were developed for robotic manipulators. The focus was on failures characterized by the loss of actuator torque at a joint, called free-swinging failures. The research results spanned many aspects of the free-swinging failure-tolerance problem, from preparing for an expected failure to discovery of postfailure capabilities to establishing efficient methods to realize those capabilities. Developed algorithms were verified using computer-based dynamic simulations, and these were further verified using hardware experiments at Johnson Space Center.

  16. Gravitational radiation theory. M.A. Thesis - Rice Univ.; [survey of current research

    NASA Technical Reports Server (NTRS)

    Wilson, T. L.

    1973-01-01

    A survey is presented of current research in the theory of gravitational radiation. The mathematical structure of gravitational radiation is stressed. Furthermore, the radiation problem is treated independently from other problems in gravitation. The development proceeds candidly through three points of view - scalar, rector, and tensor radiation theory - and the corresponding results are stated.

  17. Random Process Simulation for stochastic fatigue analysis. Ph.D. Thesis - Rice Univ., Houston, Tex.

    NASA Technical Reports Server (NTRS)

    Larsen, Curtis E.

    1988-01-01

    A simulation technique is described which directly synthesizes the extrema of a random process and is more efficient than the Gaussian simulation method. Such a technique is particularly useful in stochastic fatigue analysis because the required stress range moment E(R sup m), is a function only of the extrema of the random stress process. The family of autoregressive moving average (ARMA) models is reviewed and an autoregressive model is presented for modeling the extrema of any random process which has a unimodal power spectral density (psd). The proposed autoregressive technique is found to produce rainflow stress range moments which compare favorably with those computed by the Gaussian technique and to average 11.7 times faster than the Gaussian technique. The autoregressive technique is also adapted for processes having bimodal psd's. The adaptation involves using two autoregressive processes to simulate the extrema due to each mode and the superposition of these two extrema sequences. The proposed autoregressive superposition technique is 9 to 13 times faster than the Gaussian technique and produces comparable values for E(R sup m) for bimodal psd's having the frequency of one mode at least 2.5 times that of the other mode.

  18. Elementary particle physics and high energy phenomena. [Dept. of Physics, Univ. of Colorado, Boulder, Colorado

    SciTech Connect

    Barker, A.R.; Cumalat, J.P.; De Alwis, S.P.; DeGrand, T.A.; Ford, W.T.; Mahanthappa, K.T.; Nauenberg, U.; Rankin, P.; Smith, J.G.

    1992-06-01

    Experimental and theoretical high-energy physics programs at the University of Colorado are reported. Areas of concentration include the following: study of the properties of the Z[sup 0] with the SLD detector; fixed-target K-decay experiments; the R D program for the muon system: the SDC detector; high-energy photoproduction of states containing heavy quarks; electron--positron physics with the CLEO II detector at CESR; lattice QCD; and spin models and dynamically triangulated random surfaces. 24 figs., 2 tabs., 117 refs.

  19. Research in nuclear physics. Progress report, August 1, 1979-July 31, 1980. [Tennessee Technological Univ

    SciTech Connect

    Kozub, R L

    1980-01-01

    Research during the contract year is summarized. Results are shown for lifetimes of levels in /sup 20/F, /sup 21/F, and /sup 22/Ne, along with a decay scheme for /sup 52/Cr (with spin-parity assignments) and the relative yield of gamma-ray transitions vs average energy of coincident alpha particles from Li + /sup 51/V reactions. Completed work will be published. 6 figures. (RWR)

  20. Quantization noise in digital speech. M.S. Thesis- Houston Univ.

    NASA Technical Reports Server (NTRS)

    Schmidt, O. L.

    1972-01-01

    The amount of quantization noise generated in a digital-to-analog converter is dependent on the number of bits or quantization levels used to digitize the analog signal in the analog-to-digital converter. The minimum number of quantization levels and the minimum sample rate were derived for a digital voice channel. A sample rate of 6000 samples per second and lowpass filters with a 3 db cutoff of 2400 Hz are required for 100 percent sentence intelligibility. Consonant sounds are the first speech components to be degraded by quantization noise. A compression amplifier can be used to increase the weighting of the consonant sound amplitudes in the analog-to-digital converter. An expansion network must be installed at the output of the digital-to-analog converter to restore the original weighting of the consonant sounds. This technique results in 100 percent sentence intelligibility for a sample rate of 5000 samples per second, eight quantization levels, and lowpass filters with a 3 db cutoff of 2000 Hz.

  1. [High energy physics research]: Annual performance report, December 1, 1991--November 30, 1992. [Northwestern Univ

    SciTech Connect

    Rosen, J; Block, M; Buchholz, D; Gobbi, B; Schellman, H; Buchholz, D; Rosen, J; Miller, D; Braaten, E; Chang, D; Oakes, R; Schellman, H

    1992-01-01

    The various segments of the Northwestern University high energy physics research program are reviewed. Work is centered around experimental studies done primarily at FNAL; associated theoretical efforts are included.

  2. Annual Report for Contract Number N00014-88-K-0641 (Carnegie Mellon Univ)

    DTIC Science & Technology

    1991-09-30

    labor -intensive process of data conversion. " The described mechanism might provide a course of action for coping with the Software Release Problem, i.e...8217 reover alorihm wll uarmet:thedatbaseis estred All subsequent setq operations to variable will change the bind- to aprevousy saed onsiten stae. ng

  3. PLUM: Parallel Load Balancing for Unstructured Adaptive Meshes. Degree awarded by Colorado Univ.

    NASA Technical Reports Server (NTRS)

    Oliker, Leonid

    1998-01-01

    Dynamic mesh adaption on unstructured grids is a powerful tool for computing large-scale problems that require grid modifications to efficiently resolve solution features. By locally refining and coarsening the mesh to capture physical phenomena of interest, such procedures make standard computational methods more cost effective. Unfortunately, an efficient parallel implementation of these adaptive methods is rather difficult to achieve, primarily due to the load imbalance created by the dynamically-changing nonuniform grid. This requires significant communication at runtime, leading to idle processors and adversely affecting the total execution time. Nonetheless, it is generally thought that unstructured adaptive- grid techniques will constitute a significant fraction of future high-performance supercomputing. Various dynamic load balancing methods have been reported to date; however, most of them either lack a global view of loads across processors or do not apply their techniques to realistic large-scale applications.

  4. [Investigations in dynamics of gauge theories in theoretical particle physics]. [Virginia Polytechnic Institute State Univ. , Blacksburg

    SciTech Connect

    Not Available

    1993-01-01

    The major theme of the theoretical physics research conducted under DOE support over the past several years has been within the rubric of the standard model, and concerned the interplay between symmetries and dynamics. The research was thus carried out mostly in the context of gauge field theories, and usually in the presence of chiral fermions. Dynamical symmetry breaking was examined both from the point of view of perturbation theory, as well as from non-perturbative techniques associated with certain characteristic features of specific theories. Among the topics of research were: the implications of abelian and non-abelian anomalies on the spectrum and possible dynamical symmetry breaking in any theory, topological and conformal properties of quantum fields in two and higher dimensions, the breaking of global chiral symmetries by vector-like gauge theories such as QCD, the phenomenological implications of a strongly interacting Higgs sector in the standard model, and the application of soliton ideas to the physics to be explored at the SSC.

  5. (Calorimeter based detectors for high energy hadron colliders). [State Univ. of New York

    SciTech Connect

    Not Available

    1992-08-04

    This document provides a progress report on research that has been conducted under DOE Grant DEFG0292ER40697 for the past year, and describes proposed work for the second year of this 8 year grant starting November 15, 1992. Personnel supported by the contract include 4 faculty, 1 research faculty, 4 postdocs, and 9 graduate students. The work under this grant has in the past been directed in two complementary directions -- DO at Fermilab, and the second SSC detector GEM. A major effort has been towards the construction and commissioning of the new Fermilab Collider detector DO, including design, construction, testing, the commissioning of the central tracking and the central calorimeters. The first DO run is now underway, with data taking and analysis of the first events. Trigger algorithms, data acquisition, calibration of tracking and calorimetry, data scanning and analysis, and planning for future upgrades of the DO detector with the advent of the FNAL Main Injector are all involved. The other effort supported by this grant has been towards the design of GEM, a large and general-purpose SSC detector with special emphasis on accurate muon measurement over a large solid angle. This effort will culminate this year in the presentation to the SSC laboratory of the GEM Technical Design Report. Contributions are being made to the detector design, coordination, and physics simulation studies with special emphasis on muon final states. Collaboration with the RD5 group at CERN to study muon punch through and to test cathode strip chamber prototypes was begun.

  6. Theory of electron induced reactions. Progress report, May 1, 1980-April 30, 1981. [Ohio Univ

    SciTech Connect

    Onley, D.S.; Wright, L.E.

    1981-02-01

    (I) The problem of finite-size effects in virtual photon spectra was studied from several directions. It was found that a model-independent correction to the spectrum could be defined for energies up to 200 MeV. It is shown, however, that drastically different current distributions for an M1 transition all share the same transition radius and produce the same correction to the M1 virtual spectrum. This insensitivity to details of the transition is evidently due to a predominance of low-momentum-transfer components, which selects only comparatively low moments of the corresponding form factors. Simultaneous correction for finite size and Coulomb forces (finite charge) was studied, and an alarming interaction between the two corrections was found. (II) Coulomb distortion effects in pair production were also calculated. The distortion factor, which is the ratio of the total pair production cross section with Coulomb distortion to the plane-wave (Bethe-Heitler) result, is shown as a function of photon energy for Z = 92. (III) Some work was also done on pion electroproduction. The model showed good agreement with available experimental data. 8 figures. (RWR)

  7. A Hybrid Numerical Method for Turbulent Mixing Layers. Degree awarded by Case Western Reserve Univ.

    NASA Technical Reports Server (NTRS)

    Georgiadis, Nicholas J.

    2001-01-01

    A hybrid method has been developed for simulations of compressible turbulent mixing layers. Such mixing layers dominate the flows in exhaust systems of modern day aircraft and also those of hypersonic vehicles currently under development. The method configurations in which a dominant structural feature provides an unsteady mechanism to drive the turbulent development in the mixing layer. The hybrid method uses a Reynolds-averaged Navier-Stokes (RANS) procedure to calculate wall bounded regions entering a mixing section, and a Large Eddy Simulation (LES) procedure to calculate the mixing dominated regions. A numerical technique was developed to enable the use of the hybrid RANS-LES method on stretched, non-Cartesian grids. Closure for the RANS equations was obtained using the Cebeci-Smith algebraic turbulence model in conjunction with the wall-function approach of Ota and Goldberg. The wall-function approach enabled a continuous computational grid from the RANS regions to the LES region. The LES equations were closed using the Smagorinsky subgrid scale model. The hybrid RANS-LES method is applied to a benchmark compressible mixing layer experiment. Preliminary two dimensional calculations are used to investigate the effects of axial grid density and boundary conditions. Vortex shedding from the base region of a splitter plate separating the upstream flows was observed to eventually transition to turbulence. The location of the transition, however, was much further downstream than indicated by experiments. Actual LES calculations, performed in three spatial directions, also indicated vortex shedding, but the transition to turbulence was found to occur much closer to the beginning of the mixing section. which is in agreement with experimental observations. These calculations demonstrated that LES simulations must be performed in three dimensions. Comparisons of time-averaged axial velocities and turbulence intensities indicated reasonable agreement with experimental data.

  8. The shock process and light element production in supernovae envelopes. Ph.D. Thesis - Chicago Univ.

    NASA Technical Reports Server (NTRS)

    Brown, Lawrence E.; Dearborn, David S.; Schramm, David N.; Larsen, Jon T.; Kurokawa, Shin

    1990-01-01

    Detailed hydrodynamic modeling of the passage of supernova shocks through the hydrogen envelopes of blue and red progenitor stars was carried out to explore the sensitivity to model conditions of light element production (specifically Li-7 and B-11) which was noted by Dearborn, Schramm, Steigman and Truran (1989) (DSST). It is found that, for stellar models with M is less than or approximately 100 M solar mass, current state of the art supernova shocks do not produce significant light element yields by hydrodynamic processes alone. The dependence of this conclusion on stellar models and on shock strengths is explored. Preliminary implications for Galactic evolution of lithium are discussed, and it is suspected that intermediate mass red giant stars may be the most consistent production site for lithium.

  9. Pulmonary Edema and Plasma Volume Changes in Dysbarism. M.S. Thesis - Texas Univ.

    NASA Technical Reports Server (NTRS)

    Joki, J. A.

    1972-01-01

    Two groups of anesthetized, fasted pigs were utilized. One group of 13 animals (8.5 to 16.6 kilograms) was exposed to a high-pressure environment, and the other group of eight animals (6.9 to 20.0 kilograms) constituted the control group. The experimental group was subjected to an atmosphere of 90 percent nitrogen and 10 percent oxygen at a pressure of 50 psig for 30 minutes and then decompressed at a rate 10 psi/min. Plasma volumes, using both iodine-125-tagged-albumin and chromium-51-tagged-cell dilution techniques, were measured before, immediately after, and at 30 and 60 minutes after decompression. Aortic and right-ventricular systolic pressures were also recorded. At 60 minutes after decompression, blood samples were taken, the animals were sacrificed, and the water content of the lungs, kidneys, livers, and spleens was estimated by measuring tissue wet weight and dry weight. Protein extravasation and tissue blood volumes were determined by measuring the iodine-125-tagged-albumin and chromium-51-tagged-cell spaces in homo-genates of the organs under investigation.

  10. The effects of context on multidimensional spatial cognitive models. Ph.D. Thesis - Arizona Univ.

    NASA Technical Reports Server (NTRS)

    Dupnick, E. G.

    1979-01-01

    Spatial cognitive models obtained by multidimensional scaling represent cognitive structure by defining alternatives as points in a coordinate space based on relevant dimensions such that interstimulus dissimilarities perceived by the individual correspond to distances between the respective alternatives. The dependence of spatial models on the context of the judgments required of the individual was investigated. Context, which is defined as a perceptual interpretation and cognitive understanding of a judgment situation, was analyzed and classified with respect to five characteristics: physical environment, social environment, task definition, individual perspective, and temporal setting. Four experiments designed to produce changes in the characteristics of context and to test the effects of these changes upon individual cognitive spaces are described with focus on experiment design, objectives, statistical analysis, results, and conclusions. The hypothesis is advanced that an individual can be characterized as having a master cognitive space for a set of alternatives. When the context changes, the individual appears to change the dimension weights to give a new spatial configuration. Factor analysis was used in the interpretation and labeling of cognitive space dimensions.

  11. Liver Full Reference Set Application: David Lubman - Univ of Michigan (2011) — EDRN Public Portal

    Cancer.gov

    In this work we will perform the next step in the biomarker development and validation. This step will be the Phase 2 validation of glycoproteins that have passed Phase 1 blinded validation using ELISA kits based on target glycoproteins selected based on our previous work. This will be done in a large Phase 2 sample set obtained in a multicenter study funded by the EDRN. The assays will be performed in our research lab located in the Center for Cancer Proteomics in the University of Michigan Medical Center. This study will include patients in whom serum was stored for future validation and includes samples from early HCC (n = 158), advanced cases (n=214) and cirrhotic controls (n = 417). These samples will be supplied by the EDRN (per Dr. Jo Ann Rinaudo) and will be analyzed in a blinded fashion by Dr. Feng from the Fred Hutchinson Cancer Center. This phase 2 study was designed to have above 90% power at one-sided 5% type-I error for comparing the joint sensitivity and specificity for differentiating early stage HCC from cirrhotic patients between AFP and a new marker. Sample sizes of 200 for early stage HCC and 400 for cirrhotics were required to achieve the stated power (14). We will select our candidates for this larger phase validation set based on the results of previous work. These will include HGF and CD14 and the results of these assays will be used to evaluate the performance of each of these markers and combinations of HGF and CD14 and AFP and HGF. It is expected that each assay will be repeated three times for each marker and will also be performed for AFP as the standard for comparison. 250 uL of each sample is requested for analysis.

  12. Braided Carbon Fiber Rope Flow Characteristics. Degree awarded by Utah Univ.

    NASA Technical Reports Server (NTRS)

    Heman, J. R. C.; McCool, A. (Technical Monitor)

    2000-01-01

    I am submitting the following technical subject for consideration as a thesis topic for the master degree: The reusable solid rocket motor (RSRM) nozzle internal joints are being evaluated for the incorporation of a carbon fiber rope (CFR) as a thermal barrier. The CFR is approximately 0.260 in. diameter and is composed of approximately 12,000 carbon fibers, woven in ten sheaths or layers. The CFR is manufactured by a sub-tier vendor and subsequently several of its manufacturing details are proprietary to that vendor. The CFR design intent is to prevent hot motor combustion products and slag from intruding into the joint scaling area while still approaching a vented joint design to avoid the detriments of gas jet impingement. As a member of the Heat Transfer section at Thiokol Propulsion, two main goals exist as part of this NASA funded design effort: (1) development of flow model through the CFR and (2) development of a heat transfer model through the CFR. While both models are needed and most probably interrelated, the gas flow model is being targeted as the subject matter. Essentially, the topic would be "Modeling of Gas Flow through a Braided Carbon Fiber Rope". An AIAA journal or conference paper is being considered through Thiokol/NASA as well. A sub-scale CFR flow test fixture was designed to simulate the relative levels of CFR compression. The test fixture provides the means to measure gas mass flow rate upstream of the CFR and the pressure and temperature both upstream and downstream of the CFR. The test fixture was designed to eliminate the possibility of dynamic gapping at the CFR location and provide minimal flow resistance to ambient for gases exiting the rope. The data collected in the experiment will be evaluated to define a permeability/flow resistance model. Two possibilities exist for the flow characteristics through the CFR from choked flow to strictly friction driven. A test matrix for evaluating the CFR has been compiled, which addresses both of these characteristics. The range of pressures to be tested covers a relatively low delta pressure where non-choked flow is impossible, while the high pressure shown is dictated by the RSRM joint operating pressure where choking is possible. The test matrix, was also designed for a range of rope compressions or test fixture gaps ranging from 0.025" to 0.070". These gaps are controlled by the range of RSRM full-scale hardware joint gaps that will be expected by virtue of the joint design.

  13. Analysis of pressure spectra measurements in a ducted combustion system. Ph.D. Thesis - Toledo Univ.

    NASA Technical Reports Server (NTRS)

    Miles, J. H.

    1980-01-01

    Combustion noise propagation in an operating ducted liquid fuel combustion system is studied in relation to the development of combustion noise prediction and suppression techniques. The presence of combustor emissions in the duct is proposed as the primary mechanism producing the attenuation and dispersion of combustion noise propagating in an operating liquid fuel combustion system. First, a complex mathematical model for calculating attenuation and dispersion taking into account mass transfer, heat transfer, and viscosity effects due to the presence of liquid fuel droplets or solid soot particles is discussed. Next, a simpler single parameter model for calculating pressure auto-spectra and cross-spectra which takes into account dispersion and attenuation due to heat transfer between solid soot particles and air is developed. Then, auto-spectra and cross-spectra obtained from internal pressure measurements in a combustion system consisting of a J-47 combustor can, a spool piece, and a long duct are presented. Last, analytical results obtained with the single parameter model are compared with the experimental measurements. The single parameter model results are shown to be in excellent agreement with the measurements.

  14. Elementary particle interactions. [Dept. of Physics and Astronomy, Univ. of Tennessee, Knoxville, Tennessee

    SciTech Connect

    Bugg, W.M.; Condo, G.T.; Handler, T.; Hart, E.L.; Read, K.; Ward, B.F.L.

    1992-10-01

    Work continues on strange particle production in weak interactions using data from a high-energy neutrino exposure in a freon bubble chamber. Meson photoproduction has also consumed considerable effort. Detector research and development activities have been carried out.

  15. Workshop Report: Distributive Education Project Development Workshop. (Wisconsin Univ., Madison, July 30-August 11, 1967).

    ERIC Educational Resources Information Center

    Wisconsin Univ., Madison. School of Education.

    This report of a 2-week workshop contains four papers presented by their authors, eight business presentations, and 1 group and 24 individual projects developed by the workshop participants. The papers pertain to project evaluation, project information, project training and distributive programs. The business presentations relate to new products,…

  16. The project scientist's role in scientific spacecraft project management. M.S. Thesis - George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Eller, E. L.

    1976-01-01

    The project scientists is in a position which rates very high in terms of behavioral study recommendations. His influence over objectives is generally considered to be important. He is highly autonomous in a moderately coordinated environment. He has diverse managerial and technical functions and the performance of these functions require him to grow beyond his role as an experimenter. However, the position within the line organization for those interviewed is also very stimulating, rating almost as high by the same criteria. The role of project scientist may not be the dominant means of professional growth for the experienced scientific investigators. The influence which the project scientist exerts on the project and the stimulation of that position for him are determined largely by his position outside the defined project scientist role. The role of the project scientist is changing because the environment of those who become project scientists is changing.

  17. An Analysis of NASA Technology Transfer. Degree awarded by Pennsylvania State Univ.

    NASA Technical Reports Server (NTRS)

    Bush, Lance B.

    1996-01-01

    A review of previous technology transfer metrics, recommendations, and measurements is presented within the paper. A quantitative and qualitative analysis of NASA's technology transfer efforts is performed. As a relative indicator, NASA's intellectual property performance is benchmarked against a database of over 100 universities. Successful technology transfer (commercial sales, production savings, etc.) cases were tracked backwards through their history to identify the key critical elements that lead to success. Results of this research indicate that although NASA's performance is not measured well by quantitative values (intellectual property stream data), it has a net positive impact on the private sector economy. Policy recommendations are made regarding technology transfer within the context of the documented technology transfer policies since the framing of the Constitution. In the second thrust of this study, researchers at NASA Langley Research Center were surveyed to determine their awareness of, attitude toward, and perception about technology transfer. Results indicate that although researchers believe technology transfer to be a mission of the Agency, they should not be held accountable or responsible for its performance. In addition, the researchers are not well educated about the mechanisms to perform, or policies regarding, technology transfer.

  18. Optical sensors; Proceedings of the Meeting, National Chiao Tung Univ., Hsinchu, Taiwan, Dec. 16, 1992

    NASA Astrophysics Data System (ADS)

    Chen, Chih-Hong; Wang, Tieh-Chu

    1992-10-01

    This volume presents papers grouped under general topics of photon detectors and related technology, imaging sensor technology, and electrooptical sensing technology. Papers are presented on optoelectronics high-power control devices, quantum-effect and functional high-speed devices, the development of InSb staring image sensors, an interdigited dual-cell position-sensitive device, and the effect of temperature on the I-V characteristic of a-Si:H photodiode. Attention is given to a two-waveband thermal imaging system, bistable fiber-optic temperature sensors with high accuracy, and a new phase-reading detection method for signal processing in optical interferometric sensors. Other papers are on bias instability in the polarization-maintaining fiber gyro with imperfect polarization couplers and splices, fiber-optic electronic speckle pattern interferometry and its application to sensors, a new pressure sensor, and interface properties of passivation layers on HgCdTe. (No individual items are abstracted in this volume)

  19. Experimental investigations in particle physics at intermediate energies. [Physics Dept. , Temple Univ

    SciTech Connect

    Auerbach, L.B.; Highland, V.L.; McFarlane, K.W.; Kettell, S.H.

    1992-07-12

    The major emphasis of this project continues to be on fundamental symmetries and parameters of the Standard Model. A test of a quark model prediction was also done. The projects in the current period have been the following: LSND, a neutrino oscillation experiment at LAMPF; E791, a search for the decays K{sub L}{sup 0} {yields} {mu}e and K{sub L}{sup 0} {yields} ee; E871, tests and preparations for an upgrade proposal; and E888, a search for the H dibaryon. The LSND (Large Scintillator Neutrino Detector) is under construction at this time. Progress in the construction schedule has been accelerated with the expectation of being ready to accept beam in March 1993. The automated system for testing photomultiplier tubes is in full production, and should be able to certify a fun complement of tubes for installation by October 1992. Results of an earlier LAMPF experiment, E764, on the interaction of muon neutrinos with carbon nuclei have been submitted for publication. A thorough 'blind' analysis of the E791 data set has just been brought to completion. Final results for the upper limits (90% C.L.) on the branching ratios for the decays K{sub L}{sup 0} {yields} {mu}e and K{sub L}{sup 0} {yields} ee are 3.3 {times} 10{sup {minus}11} and 4.1 {times} 10{sup {minus}11}, respectively. The final result for the branching ratio for K{sub L}{sup 0} {yields} {mu}{mu} from all the data (720 events) is (7.0 {plus minus} 0.4 {plus minus} 0.2) {times} 10{sup {minus}9}. The potential of the E791 detector for rare K decays has reached its limit. Before disassembly it was used to mount a search (E888) for a possible long-lived six-quark state, the H. At the same time studies have been made of an upgraded version of the experiment (E871) that will make use of a portion of the existing apparatus.

  20. Stability of large horizontal-axis axisymmetric wind turbines. Ph.D. Thesis - Delaware Univ.

    NASA Technical Reports Server (NTRS)

    Hirschbein, M. S.; Young, M. I.

    1980-01-01

    The stability of large horizontal axis, axi-symmetric, power producing wind turbines was examined. The analytical model used included the dynamic coupling of the rotor, tower and power generating system. The aerodynamic loading was derived from blade element theory. Each rotor blade was permitted tow principal elastic bending degrees of freedom, one degree of freedom in torsion and controlled pitch as a rigid body. The rotor hub was mounted in a rigid nacelle which may yaw freely or in a controlled manner. The tower can bend in two principal directions and may twist. Also, the rotor speed can vary and may induce perturbation reactions within the power generating equipment. Stability was determined by the eigenvalues of a set of linearized constant coefficient differential equations. All results presented are based on a 3 bladed, 300 ft. diameter, 2.5 megawatt wind turbine. Some of the parameters varied were; wind speed, rotor speed structural stiffness and damping, the effective stiffness and damping of the power generating system and the principal bending directions of the rotor blades. Unstable or weakly stable behavior can be caused by aerodynamic forces due to motion of the rotor blades and tower in the plane of rotation or by mechanical coupling between the rotor system and the tower.

  1. Satellite Observations of Rapidly Varying Cosmic X-ray Sources. Ph.D. Thesis - Catholic Univ.

    NASA Technical Reports Server (NTRS)

    Maurer, G. S.

    1979-01-01

    The X-ray source data obtained with the high energy celestial X-ray detector on the Orbiting Solar Observatory -8 are presented. The results from the 1977 Crab observation show nonstatistical fluctuations in the pulsed emission and in the structure of the integrated pulse profile which cannot be attributed to any known systematic effect. The Hercules observations presented here provide information on three different aspects of the pulsed X-ray emission: the variation of pulsed flux as a function of the time from the beginning of the ON-state, the variation of pulsed flux as a function of binary phase, and the energy spectrum of the pulse emission.

  2. A contracting-interval program for the Danilewski method. Ph.D. Thesis - Va. Univ.

    NASA Technical Reports Server (NTRS)

    Harris, J. D.

    1971-01-01

    The concept of contracting-interval programs is applied to finding the eigenvalues of a matrix. The development is a three-step process in which (1) a program is developed for the reduction of a matrix to Hessenberg form, (2) a program is developed for the reduction of a Hessenberg matrix to colleague form, and (3) the characteristic polynomial with interval coefficients is readily obtained from the interval of colleague matrices. This interval polynomial is then factored into quadratic factors so that the eigenvalues may be obtained. To develop a contracting-interval program for factoring this polynomial with interval coefficients it is necessary to have an iteration method which converges even in the presence of controlled rounding errors. A theorem is stated giving sufficient conditions for the convergence of Newton's method when both the function and its Jacobian cannot be evaluated exactly but errors can be made proportional to the square of the norm of the difference between the previous two iterates. This theorem is applied to prove the convergence of the generalization of the Newton-Bairstow method that is used to obtain quadratic factors of the characteristic polynomial.

  3. [Research programs on elementary particle and field theories and superconductivity]. [Rockefeller Univ

    SciTech Connect

    Khuri, N.N.

    1992-01-01

    Research of staff members in theoretical physics is presented in the following areas: super string theory, a new approach to path integrals, new ideas on the renormalization group, nonperturbative chiral gauge theories, the standard model, K meson decays, and the CP problem. Work on high-[Tc] superconductivity and protein folding is also related.

  4. Development of a grid-independent approximate Riemannsolver. Ph.D. Thesis - Michigan Univ.

    NASA Technical Reports Server (NTRS)

    Rumsey, Christopher Lockwood

    1991-01-01

    A grid-independent approximate Riemann solver for use with the Euler and Navier-Stokes equations was introduced and explored. The two-dimensional Euler and Navier-Stokes equations are described in Cartesian and generalized coordinates, as well as the traveling wave form of the Euler equations. The spatial and temporal discretization are described for both explicit and implicit time-marching schemes. The grid-aligned flux function of Roe is outlined, while the 5-wave grid-independent flux function is derived. The stability and monotonicity analysis of the 5-wave model are presented. Two-dimensional results are provided and extended to three dimensions. The corresponding results are presented.

  5. Hydrodynamic models of a cepheid atmosphere. Ph.D. Thesis - Maryland Univ., College Park

    NASA Technical Reports Server (NTRS)

    Karp, A. H.

    1974-01-01

    A method for including the solution of the transfer equation in a standard Henyey type hydrodynamic code was developed. This modified Henyey method was used in an implicit hydrodynamic code to compute deep envelope models of a classical Cepheid with a period of 12(d) including radiative transfer effects in the optically thin zones. It was found that the velocity gradients in the atmosphere are not responsible for the large microturbulent velocities observed in Cepheids but may be responsible for the occurrence of supersonic microturbulence. It was found that the splitting of the cores of the strong lines is due to shock induced temperature inversions in the line forming region. The adopted light, color, and velocity curves were used to study three methods frequently used to determine the mean radii of Cepheids. It is concluded that an accuracy of 10% is possible only if high quality observations are used.

  6. Performance of finned thermal capacitors. Ph.D. Thesis - Texas Univ., Austin

    NASA Technical Reports Server (NTRS)

    Humphries, W. R.

    1974-01-01

    The performance of typical thermal capacitors, both in earth and orbital environments, was investigated. Techniques which were used to make predictions of thermal behavior in a one-g earth environment are outlined. Orbital performance parameters are qualitatively discussed, and those effects expected to be important under zero-g conditions are outlined. A summary of thermal capacitor applications are documentated, along with significant problem areas and current configurations. An experimental program was conducted to determine typical one-g performance, and the physical significance of these data is discussed in detail. Numerical techniques were employed to allow comparison between analytical and experimental data.

  7. Relativistic heavy ion research. [Dept. of Physics and Astronomy, Wayne State Univ. , Detroit, Michigan

    SciTech Connect

    Not Available

    1992-01-01

    Experimental work is reported on the following topics: transverse energy production in 10.7-GeV/c/u Au on Au collisions; first results on delta ray production and charged particle multiplicities with the Au beam at 10.7 GeV/c/A; preliminary studies on the feasibility of flow measurement with the E814 participant calorimeter; preliminary results from the E877 telescope; and low-p[sub t] baryon distribution in Si+Al, Pb collisions at the AGS. Then the status of the Hadronic Calorimeter project of AGS Experiment E864 (ECOS--Exotic Composite Object Spectrometer) is reviewed. Next, the same is done for work of the STAR RHIC collaboration (Silicon Vertex Tracker (SVT) project evolution and development in FY92, SVT software results from 1992, SVT instrumentation, FY93 SVT pion test beam). The instrumentation section deals with the design and installation of a target rapidity telescope for BNL experiment 814/877 and a repair scheme for the E814/E877 participant calorimeter. Finally, the theory part addresses bosonic kinetics: thermalization of mesons and the pion p[sub perpendicular] spectrum in ultrarelativistic heavy-ion collisions and non-equilibrium properties of hadronic mixtures.

  8. The Numerical Analysis of a Turbulent Compressible Jet. Degree awarded by Ohio State Univ., 2000

    NASA Technical Reports Server (NTRS)

    DeBonis, James R.

    2001-01-01

    A numerical method to simulate high Reynolds number jet flows was formulated and applied to gain a better understanding of the flow physics. Large-eddy simulation was chosen as the most promising approach to model the turbulent structures due to its compromise between accuracy and computational expense. The filtered Navier-Stokes equations were developed including a total energy form of the energy equation. Subgrid scale models for the momentum and energy equations were adapted from compressible forms of Smagorinsky's original model. The effect of using disparate temporal and spatial accuracy in a numerical scheme was discovered through one-dimensional model problems and a new uniformly fourth-order accurate numerical method was developed. Results from two- and three-dimensional validation exercises show that the code accurately reproduces both viscous and inviscid flows. Numerous axisymmetric jet simulations were performed to investigate the effect of grid resolution, numerical scheme, exit boundary conditions and subgrid scale modeling on the solution and the results were used to guide the three-dimensional calculations. Three-dimensional calculations of a Mach 1.4 jet showed that this LES simulation accurately captures the physics of the turbulent flow. The agreement with experimental data was relatively good and is much better than results in the current literature. Turbulent intensities indicate that the turbulent structures at this level of modeling are not isotropic and this information could lend itself to the development of improved subgrid scale models for LES and turbulence models for RANS simulations. A two point correlation technique was used to quantify the turbulent structures. Two point space correlations were used to obtain a measure of the integral length scale, which proved to be approximately 1/2 D(sub j). Two point space-time correlations were used to obtain the convection velocity for the turbulent structures. This velocity ranged from 0.57 to 0.71 U(sub j).

  9. An indirect optimization method with improved convergence characteristics. Ph.D. Thesis - Houston Univ.

    NASA Technical Reports Server (NTRS)

    Doiron, H. H.

    1972-01-01

    A method is presented for obtaining numerical solutions to a certain class of two-point boundary value problems which arise in optimal control theory. The problems are characterized by systems of nonlinear ordinary differential equations with nonlinear boundary conditions.

  10. Nuclear analytical techniques with neutron beams at the Univ. of Texas at Austin

    SciTech Connect

    Uenlue, K.; Wehring, B.W.

    1996-12-31

    Neutron beams produced by nuclear research reactors can be used for analytical chemical analysis by measuring nuclear radiation produced by neutron capture. Prompt gamma activation analysis (PGAA) and neutron depth profiling (NDP) are two such analytical techniques. For the last three decades, these techniques have been applied at a number of research reactors around the world. Within the last 4 yr, we have developed NDP and PGAA facilities at The University of Texas at Austin research reactor, a 1-MW TRIGA Mark II reactor. Brief descriptions of the facilities and summaries of activities for these analytical techniques at the University of Texas at Austin are provided in this paper.

  11. Dynamics of a class of vortex rings. Ph.D. Thesis - Stanford Univ.

    NASA Technical Reports Server (NTRS)

    Shariff, Karim; Leonard, Anthony; Ferziger, Joel H.

    1989-01-01

    The contour dynamics method is extended to vortex rings with vorticity varying linearly from the symmetry axis. An elliptic core model is also developed to explain some of the basic physics. Passage and collisions of two identical rings are studied focusing on core deformation, sound generation and stirring of fluid elements. With respect to core deformation, not only the strain rate but how rapidly it varies is important and accounts for greater susceptibility to vortex tearing than in two dimensions. For slow strain, as a passage interaction is completed and the strain relaxes, the cores return to their original shape while permanent deformations remain for rapidly varying strain. For collisions, if the strain changes slowly the core shapes migrate through a known family of two-dimensional steady vortex pairs up to the limiting member of the family. Thereafter energy conservation does not allow the cores to maintain a constant shape. For rapidly varying strain, core deformation is severe and a head-tail structure in good agreement with experiments is formed. With respect to sound generation, good agreement with the measured acoustic signal for colliding rings is obtained and a feature previously thought to be due to viscous effects is shown to be an effect of inviscid core deformation alone. For passage interactions, a component of high frequency is present. Evidence for the importance of this noise source in jet noise spectra is provided. Finally, processes of fluid engulfment and rejection for an unsteady vortex ring are studied using the stable and unstable manifolds. The unstable manifold shows excellent agreement with flow visualization experiments for leapfrogging rings suggesting that it may be a good tool for numerical flow visualization in other time periodic flows.

  12. Evolution of domain walls in the early universe. Ph.D. Thesis - Chicago Univ.

    NASA Technical Reports Server (NTRS)

    Kawano, Lawrence

    1989-01-01

    The evolution of domain walls in the early universe is studied via 2-D computer simulation. The walls are initially configured on a triangular lattice and then released from the lattice, their evolution driven by wall curvature and by the universal expansion. The walls attain an average velocity of about 0.3c and their surface area per volume (as measured in comoving coordinates) goes down with a slope of -1 with respect to conformal time, regardless of whether the universe is matter or radiation dominated. The additional influence of vacuum pressure causes the energy density to fall away from this slope and steepen, thus allowing a situation in which domain walls can constitute a significant portion of the energy density of the universe without provoking an unacceptably large perturbation upon the microwave background.

  13. Liquid jet impingement normal to a disk in zero gravity. Ph.D. Thesis - Toledo Univ.

    NASA Technical Reports Server (NTRS)

    Labus, T. L.

    1976-01-01

    An experimental and analytical investigation was conducted to determine the free surface shapes of circular liquid jets impinging normal to sharp-edged disks under both normal and zero gravity conditions. An order of magnitude analysis was conducted indicating regions where viscous forces were not significant when computing free surface shapes. The demarcation between the viscous and inviscid region was found to depend upon the flow Reynolds number and the ratio between the jet and disk radius.

  14. An Empirical Method for Determining the Lunar Gravity Field. Ph.D. Thesis - George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Ferrari, A. J.

    1971-01-01

    A method has been devised to determine the spherical harmonic coefficients of the lunar gravity field. This method consists of a two-step data reduction and estimation process. In the first step, a weighted least-squares empirical orbit determination scheme is applied to Doppler tracking data from lunar orbits to estimate long-period Kepler elements and rates. Each of the Kepler elements is represented by an independent function of time. The long-period perturbing effects of the earth, sun, and solar radiation are explicitly modeled in this scheme. Kepler element variations estimated by this empirical processor are ascribed to the non-central lunar gravitation features. Doppler data are reduced in this manner for as many orbits as are available. In the second step, the Kepler element rates are used as input to a second least-squares processor that estimates lunar gravity coefficients using the long-period Lagrange perturbation equations.

  15. Solid state polymerization and crystallography of polyimide precursors. Ph.D. Thesis - Va. Univ.

    NASA Technical Reports Server (NTRS)

    Wakelyn, N. T.

    1974-01-01

    Although the production of crystallinity in a polymeric system has historically led to commerically useful properties, the polyimides, prized for their high temperature characteristics, as customarily synthesized by melt or solution casting, are amorphous. It is shown that polymide containing residual crystallinity can be synthesized by isothermal annealing of crystals of the salt of the diisopropyl ester of pyromellitic acid and phenylene diamine. The reaction is topochemical in that the geometry of the polymer product is dependent upon that of the crystalline precursor. Infrared spectroscopy reveals the presence of imide absorption in the polymer, while powder diffractometry suggests residual crystallinity. Single crystal X-ray analysis of the monomer yields a structure of chains of alternating acid and base suggesting that the monomer is amenable to polymerization with a minimum of geometrical disruption.

  16. Liver Rapid Reference Set Application: Timothy Block - Drexel Univ (2008) — EDRN Public Portal

    Cancer.gov

    The goal of this application is to determine if the levels of serum GP73 and fucosylated kininogen/acute phase proteins can be used to detect hepatocellular carcinoma (HCC) in the background of liver cirrhosis. The use of the validation set would allow us to directly compare GP73 and fucosylated markers against AFP, AFP-L3 and DCP as well as test them in combination with these markers

  17. Active feed array compensation for reflector antenna surface distortions. Ph.D. Thesis - Akron Univ., Ohio

    NASA Technical Reports Server (NTRS)

    Acosta, Roberto J.

    1988-01-01

    The feasibility of electromagnetic compensation for reflector antenna surface distortions is investigated. The performance characteristics of large satellite communication reflector antenna systems degrade as the reflector surface distorts, mainly due to thermal effects from solar radiation. The technique developed can be used to maintain the antenna boresight directivity and sidelobe level independent of thermal effects on the reflector surface. With the advent of monolithic microwave integrated circuits (MMIC), a greater flexibility in array fed reflector antenna systems can be achieved. MMIC arrays provide independent control of amplitude and phase for each of the many radiating elements in the feed array. By assuming a known surface distortion profile, a simulation study is carried out to examine the antenna performance as a function of feed array size and number of elements. Results indicate that the compensation technique can effectively control boresight directivity and sidelobe level under peak surface distortion in the order of tenth of a wavelength.

  18. Elastohydrodynamic lubrication of point contacts. Ph.D. Thesis - Leeds Univ.

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.

    1976-01-01

    A procedure for the numerical solution of the complete, isothermal, elastohydrodynamic lubrication problem for point contacts is given. This procedure calls for the simultaneous solution of the elasticity and Reynolds equations. By using this theory the influence of the ellipticity parameter and the dimensionless speed, load, and material parameters on the minimum and central film thicknesses was investigated. Thirty-four different cases were used in obtaining the fully flooded minimum- and central-film-thickness formulas. Lubricant starvation was also studied. From the results it was possible to express the minimum film thickness for a starved condition in terms of the minimum film thickness for a fully flooded condition, the speed parameter, and the inlet distance. Fifteen additional cases plus three fully flooded cases were used in obtaining this formula. Contour plots of pressure and film thickness in and around the contact have been presented for both fully flooded and starved lubrication conditions.

  19. Liquid crystal point diffraction interferometer. Ph.D. Thesis - Arizona Univ., 1995

    NASA Technical Reports Server (NTRS)

    Mercer, Carolyn R.

    1995-01-01

    A new instrument, the liquid crystal point diffraction-interferometer (LCPDI), has been developed for the measurement of phase objects. This instrument maintains the compact, robust design of Linnik's point diffraction interferometer (PDI) and adds to it phase stepping capability for quantitative interferogram analysis. The result is a compact, simple to align, environmentally insensitive interferometer capable of accurately measuring optical wavefronts with very high data density and with automated data reduction. This dissertation describes the theory of both the PDI and liquid crystal phase control. The design considerations for the LCPDI are presented, including manufacturing considerations. The operation and performance of the LCPDI are discussed, including sections regarding alignment, calibration, and amplitude modulation effects. The LCPDI is then demonstrated using two phase objects: defocus difference wavefront, and a temperature distribution across a heated chamber filled with silicone oil. The measured results are compared to theoretical or independently measured results and show excellent agreement. A computer simulation of the LCPDI was performed to verify the source of observed periodic phase measurement error. The error stems from intensity variations caused by dye molecules rotating within the liquid crystal layer. Methods are discussed for reducing this error. Algorithms are presented which reduce this error; they are also useful for any phase-stepping interferometer that has unwanted intensity fluctuations, such as those caused by unregulated lasers.

  20. Thermal behavior spiral bevel gears. Ph.D. Thesis - Case Western Univ., Aug. 1993

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.

    1995-01-01

    An experimental and analytical study of the thermal behavior of spiral bevel gears is presented. Experimental data were taken using thermocoupled test hardware and an infrared microscope. Many operational parameters were varied to investigate their effects on the thermal behavior. The data taken were also used to validate the boundary conditions applied to the analytical model. A finite element-based solution sequence was developed. The three-dimensional model was developed based on the manufacturing process for these gears. Contact between the meshing gears was found using tooth contact analysis to describe the location, curvatures, orientations, and surface velocities. This information was then used in a three-dimensional Hertzian contact analysis to predict contact ellipse size and maximum pressure. From these results, an estimate of the heat flux magnitude and the location on the finite element model was made. The finite element model used time-averaged boundary conditions to permit the solution to attain steady state in a computationally efficient manner.Then time- and position-varying boundary conditions were applied to the model to analyze the cyclic heating and cooling due to the gears meshing and transferring heat to the surroundings, respectively. The model was run in this mode until the temperature behavior stabilized. The transient flash temperature on the surface was therefore described. The analysis can be used to predict the overall expected thermal behavior of spiral bevel gears. The experimental and analytical results were compared for this study and also with a limited number of other studies. The experimental and analytical results attained in the current study were basically within 10% of each other for the cases compared. The experimental comparison was for bulk thermocouple locations and data taken with an infrared microscope. The results of a limited number of other studies were compared with those obtained herein and predicted the same basic behavior.

  1. Education Research and Teaching in Astrophysical & Planetary Sciences at the Univ. of Colorado

    NASA Astrophysics Data System (ADS)

    Duncan, D. K.; Arthurs, L.

    2009-12-01

    The Department of Astrophysical and Planetary sciences at the University of Colorado has increasingly been incorporating research-based science education practices. The Colorado physics education research (PER) group is now one of the largest and most productive in the nation. It includes the work of Nobel laureate Carl Wieman's Science Education Initiative. Discipline-based education researchers in physics, astronomy, geology, and other departments meet weekly. Like physics, essentially all large courses in Astrophysical and Planetary Sciences are now taught using peer instruction and "clickers." Approximately 17,000 clickers are in use at CU. A new diagnostic instrument whose subject is (modern) solar system astronomy has been developed and is available for testing. The first-ever departmental Ph.D. in astronomy education research (AER) is under way. A curriculum that encourages students to use more scientific thinking in everyday life and to distinguish good science from bad has been successfully tested. It can be used as part of any introductory geology or astronomy course. Two faculty members are conducting AER, supported by NSF Grant No. 0715517, a CCLI Phase III Grant for the Collaboration of Astronomy Teaching Scholars (CATS) Program. Neither of these two faculty members are in tenure-track lines.

  2. An investigation of gear mesh failure prediction techniques. M.S. Thesis - Cleveland State Univ.

    NASA Technical Reports Server (NTRS)

    Zakrajsek, James J.

    1989-01-01

    A study was performed in which several gear failure prediction methods were investigated and applied to experimental data from a gear fatigue test apparatus. The primary objective was to provide a baseline understanding of the prediction methods and to evaluate their diagnostic capabilities. The methods investigated use the signal average in both the time and frequency domain to detect gear failure. Data from eleven gear fatigue tests were recorded at periodic time intervals as the gears were run from initiation to failure. Four major failure modes, consisting of heavy wear, tooth breakage, single pits, and distributed pitting were observed among the failed gears. Results show that the prediction methods were able to detect only those gear failures which involved heavy wear or distributed pitting. None of the methods could predict fatigue cracks, which resulted in tooth breakage, or single pits. It is suspected that the fatigue cracks were not detected because of limitations in data acquisition rather than in methodology. Additionally, the frequency response between the gear shaft and the transducer was found to significantly affect the vibration signal. The specific frequencies affected were filtered out of the signal average prior to application of the methods.

  3. Contribution to the Performance Determination of Microjets. Ph.D. Thesis - Technical Univ., Feb. 1983

    NASA Technical Reports Server (NTRS)

    Hayn, D.

    1984-01-01

    Theoretical investigations are made on the performance of microjets. A description is given of experiments with micropropulsion units to correlate the results obtained in the first part of the report. Execution of performance measurements is discussed, and error calculations are presented.

  4. Dynamics of a split torque helicopter transmission. M.S. Thesis - Cleveland State Univ.

    NASA Technical Reports Server (NTRS)

    Krantz, Timothy L.

    1994-01-01

    Split torque designs, proposed as alternatives to traditional planetary designs for helicopter main rotor transmissions, can save weight and be more reliable than traditional designs. This report presents the results of an analytical study of the system dynamics and performance of a split torque gearbox that uses a balance beam mechanism for load sharing. The Lagrange method was applied to develop a system of equations of motion. The mathematical model includes time-varying gear mesh stiffness, friction, and manufacturing errors. Cornell's method for calculating the stiffness of spur gear teeth was extended and applied to helical gears. The phenomenon of sidebands spaced at shaft frequencies about gear mesh fundamental frequencies was simulated by modeling total composite gear errors as sinusoid functions. Although the gearbox has symmetric geometry, the loads and motions of the two power paths differ. Friction must be considered to properly evaluate the balance beam mechanism. For the design studied, the balance beam is not an effective device for load sharing unless the coefficient of friction is less than 0.003. The complete system stiffness as represented by the stiffness matrix used in this analysis must be considered to precisely determine the optimal tooth indexing position.

  5. Calculation of Propulsive Nozzle Flowfields in Multidiffusing Chemically Reacting Environments. Ph.D. Thesis - Purdue Univ.

    NASA Technical Reports Server (NTRS)

    Kacynski, Kenneth John

    1994-01-01

    An advanced engineering model has been developed to aid in the analysis and design of hydrogen/oxygen chemical rocket engines. The complete multispecies, chemically reacting and multidiffusing Navier-Stokes equations are modelled, including the Soret thermal diffusion and the Dufour energy transfer terms. In addition to the spectrum of multispecies aspects developed, the model developed in this study is also conservative in axisymmetric flow for both inviscid and viscous flow environments and the boundary conditions employ a viscous, chemically reacting, reference plane characteristics method. Demonstration cases are presented for a 1030:1 area ratio nozzle, a 25 lbf film cooled nozzle, and a transpiration cooled plug and spool rocket engine. The results indicate that the thrust coefficient predictions of the 1030:1 and the 25 lbf film cooled nozzle are within 0.2 to 0.5 percent, respectively, of experimental measurements when all of the chemical reaction and diffusion terms are considered. Further, the model's predictions agree very well with the heat transfer measurements made in all of the nozzle test cases. The Soret thermal diffusion term is demonstrated to have a significant effect on the predicted mass fraction of hydrogen along the wall of the nozzle in both the laminar flow 1030:1 nozzle and the turbulent flow plug and spool nozzle analysis cases performed. Further, the Soret term was shown to represent an important fraction of the diffusion fluxes occurring in a transpiration cooled rocket engine.

  6. Pulsed multiwavelength laser ranging system. Ph.D. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Abshire, J. B.

    1982-01-01

    A pulsed multiwavelength laser ranging system for measuring atmospheric delay was built and tested, and its theoretical performance limits were calculated. The system uses a dye modelocked ND:YAG laser, which transmits 70 psec wide pulses simultaneously at 1064, 532, and 355 nm. The differential delay of the 1064 and 355 nm pulses is measured by a specially calibrated waveform digitizer to estimate the dry atmospheric delay. The delay time of the 532 nm pulse is used to measure the target distance. Static crossed field photomultipliers are used as detectors for all wavelengths. Theoretical analysis shows that path curvature and atmospheric turbulence are fundamental limits to the ranging accuracy of both single and multicolor systems operating over horizontal paths. For two color systems, an additional error is caused by the uncertainty in the path averaged water vapor. The standard deviation of the multicolor instrument's timing measurements is directly proportional to the laser pulse width plus photomultiplier jitter divided by the square root of the received photoelectron number. The prototype system's maximum range is km, which is limited by atmospheric and system transmission losses at 355 nm. System signal detection and false alarm calculations are also presented.

  7. [Electromagnetic studies of nuclear structure and reactions]. [Nuclear Physics Group, Univ. of New Hampshire

    SciTech Connect

    Not Available

    1992-01-01

    The experimental goals are focused on developing an understanding of strong interactions and the structure of hadronic systems by determination of the electromagnetic response; these goals will be accomplished through coincidence detection of final states. Nuclear modeling objectives are to organize and interpret the data through a consistent description of a broad spectrum of reaction observables; calculations are performed in a nonrelativistic diagrammatic framework as well as a relativistic QHD approach. Work is described according to the following arrangement: direct knockout reactions (completion of [sup 16]O(e,e[prime]p), [sup 12]C(e,e[prime]pp) progress, large acceptance detector physics simulations), giant resonance studies (intermediate-energy experiments with solid-state detectors, the third response function in [sup 12]C(e,e[prime]p[sub 0]) and [sup 16]O(e,e[prime]p[sub 0]), comparison of the [sup 12]C(e, e[prime]p[sub 0]) and [sup 16]O(e,e[prime]p[sub 3]) reactions, quadrupole strength in the [sup 16]O(e,e[prime][alpha][sub 0]) reaction, quadrupole strength in the [sup 12]C(e,e[prime][alpha]) reaction, analysis of the [sup 12]C(e,e[prime]p[sub 1]) and [sup 16]O(e,e[prime]p[sub 3]) angular distributions, analysis of the [sup 40]Ca(e,e[prime]x) reaction at low q, analysis of the higher-q [sup 12]C(e,e[prime]x) data from Bates), models of nuclear structure (experimental work, Hartree-Fock calculations, phonon excitations in spherical nuclei, shell model calculations, variational methods for relativistic fields), and instrumentation development efforts (developments at CEBAF, CLAS contracts, BLAST developments).

  8. Numerical simulation of separated flows. Ph.D. Thesis - Stanford Univ., Calif.

    NASA Technical Reports Server (NTRS)

    Spalart, P. R.; Leonard, A.; Baganoff, D.

    1983-01-01

    A new numerical method, based on the Vortex Method, for the simulation of two-dimensional separated flows, was developed and tested on a wide range of gases. The fluid is incompressible and the Reynolds number is high. A rigorous analytical basis for the representation of the Navier-Stokes equation in terms of the vorticity is used. An equation for the control of circulation around each body is included. An inviscid outer flow (computed by the Vortex Method) was coupled with a viscous boundary layer flow (computed by an Eulerian method). This version of the Vortex Method treats bodies of arbitrary shape, and accurately computes the pressure and shear stress at the solid boundary. These two quantities reflect the structure of the boundary layer. Several versions of the method are presented and applied to various problems, most of which have massive separation. Comparison of its results with other results, generally experimental, demonstrates the reliability and the general accuracy of the new method, with little dependence on empirical parameters. Many of the complex features of the flow past a circular cylinder, over a wide range of Reynolds numbers, are correctly reproduced.

  9. Photogrammetry and Videogrammetry Methods Development for Solar Sail Structures. Masters Thesis awarded by George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Pappa, Richard S. (Technical Monitor); Black, Jonathan T.

    2003-01-01

    This report discusses the development and application of metrology methods called photogrammetry and videogrammetry that make accurate measurements from photographs. These methods have been adapted for the static and dynamic characterization of gossamer structures, as four specific solar sail applications demonstrate. The applications prove that high-resolution, full-field, non-contact static measurements of solar sails using dot projection photogrammetry are possible as well as full-field, non-contact, dynamic characterization using dot projection videogrammetry. The accuracy of the measurement of the resonant frequencies and operating deflection shapes that were extracted surpassed expectations. While other non-contact measurement methods exist, they are not full-field and require significantly more time to take data.

  10. Boundary-layer separation on isolated boattail nozzles. M.S. Thesis - George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Abeyounis, W. K.

    1978-01-01

    An angle of attack of 0 deg was investigated in the Langley 16 foot transonic tunnel at free-stream Mach numbers from 0.40 to 0.95 to study the phenomenon of separated flow on a series of circular-arc afterbodies. Both high-pressure air and solid circular cylinders with the cylinder diameter equal to the nozzle-exit diameter were used to simulate jet exhausts. The results indicate that boundary-layer separation is most extensive on steep boattails at high Mach numbers. The jet total-pressure ratio changes (jet total pressure to free-stream static pressure) affected the extent of separation very little; however, comparison of the separation data obtained by using the two jet-simulation techniques indicate that entrainment associated with the presence of a jet had a significant effect on the extent of separation. The solid-simulator separation data were also used to evaluate the predictions of eight separation criteria.

  11. Microgravity vibration isolation technology: Development to demonstration. Ph.D. Thesis - Case Western Reserve Univ.

    NASA Technical Reports Server (NTRS)

    Grodsinsky, Carlos M.

    1993-01-01

    The low gravity environment provided by space flight has afforded the science community a unique area for the study of fundamental and technological sciences. However, the dynamic environment observed on space shuttle flights and predicted for Space Station Freedom has complicated the analysis of prior 'microgravity' experiments and prompted concern for the viability of proposed space experiments requiring long term, low gravity environments. Thus, isolation systems capable of providing significant improvements to this random environment have been developed. This dissertation deals with the design constraints imposed by acceleration sensitive, microgravity experiment payloads in the unique environment of space. A theoretical background for the inertial feedback and feedforward isolation of a payload was developed giving the basis for two experimental active inertial isolation systems developed for the demonstration of these advanced active isolation techniques. A prototype six degree of freedom digital active isolation system was designed and developed for the ground based testing of an actively isolated payload in three horizontal degrees of freedom. A second functionally equivalent system was built for the multi-dimensional testing of an active inertial isolation system in a reduced gravity environment during low gravity aircraft trajectories. These multi-input multi-output control systems are discussed in detail with estimates on acceleration noise floor performance as well as the actual performance acceleration data. The attenuation performance is also given for both systems demonstrating the advantages between inertial and non-inertial control of a payload for both the ground base environment and the low gravity aircraft acceleration environment. A future goal for this area of research is to validate the technical approaches developed to the 0.01 Hz regime by demonstrating a functional active inertial feedforward/feedback isolation system during orbital flight. A NASA IN-STEP flight experiment has been proposed to accomplish this goal, and the expected selection for the IN-STEP program has been set for Jul. of 1993.

  12. Residual Stress Reversal in Highly Strained Shot Peened Structural Elements. Degree awarded by Florida Univ.

    NASA Technical Reports Server (NTRS)

    Mitchell, William S.; Throckmorton, David (Technical Monitor)

    2002-01-01

    The purpose of this research was to further the understanding of a crack initiation problem in a highly strained pressure containment housing. Finite Element Analysis methods were used to model the behavior of shot peened materials undergoing plastic deformation. Analytical results are in agreement with laboratory tensile tests that simulated the actual housing load conditions. These results further validate the original investigation finding that the shot peened residual stress had reversed, changing from compressive to tensile, and demonstrate that analytical finite element methods can be used to predict this behavior.

  13. Topics in Astrophysical X-Ray and Gamma Ray Spectroscopy. Ph.D. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Bussard, R. W.

    1978-01-01

    A number of topics relating to astrophysical observations that have already been made or are currently planned of spectral features, mostly emission lines, in the X-ray and gamma ray region of the electromagnetic spectrum are investigated. These topics include: the production of characteristic X-ray and gamma ray lines by nonthermal ions, spectral features induced by processes occurring in strong magnetic fields, and the positron annihilation line at 0.5 MeV. The rate of X-ray production at 6.8 keV by the 2p to 1s transition in fast hydrogen- and helium-like iron ions, following both electron capture to excited levels and collisional excitation is calculated. The cross section for electron-ion Coulomb collisions in strong fields is also calculated.

  14. [Experimental and theoretical high energy physics program]. [Purdue Univ. , West Lafayette, Indiana

    SciTech Connect

    Finley, J.; Gaidos, J.A.; Loeffler, F.J.; McIlwain, R.L.; Miller, D.H.; Palfrey, T.R.; Shibata, E.I.; Shipsey, I.P.

    1993-04-01

    Experimental and theoretical high-energy physics research at Purdue is summarized in a number of reports. Subjects treated include the following: the CLEO experiment for the study of heavy flavor physics; gas microstrip detectors; particle astrophysics; affine Kac[endash]Moody algebra; nonperturbative mass bounds on scalar and fermion systems due to triviality and vacuum stability constraints; resonance neutrino oscillations; e[sup +]e[sup [minus

  15. Theory and Development of Position-Sensitive Quantum Calorimeters. Degree awarded by Stanford Univ.

    NASA Technical Reports Server (NTRS)

    Figueroa-Feliciano, Enectali; White, Nicholas E. (Technical Monitor)

    2001-01-01

    Quantum calorimeters are being developed as imaging spectrometers for future X-ray astrophysics observatories. Much of the science to be done by these instruments could benefit greatly from larger focal-plane coverage of the detector (without increasing pixel size). An order of magnitude more area will greatly increase the science throughput of these future instruments. One of the main deterrents to achieving this goal is the complexity of the readout schemes involved. We have devised a way to increase the number of pixels from the current baseline designs by an order of magnitude without increasing the number of channels required for readout. The instrument is a high energy resolution, distributed-readout imaging spectrometer called a Position-Sensitive Transition-Edge Sensor (POST). A POST is a quantum calorimeter consisting of two Transition-Edge Sensors (TESS) on the ends of a long absorber capable of one-dimensional imaging spectroscopy. Comparing rise time and energy information from the two TESS, the position of the event in the POST is determined. The energy of the event is inferred from the sum of the two pulses. We have developed a generalized theoretical formalism for distributed-readout calorimeters and apply it to our devices. We derive the noise theory and calculate the theoretical energy resolution of a POST. Our calculations show that a 7-pixel POST with 6 keV saturation energy can achieve 2.3 eV resolution, making this a competitive design for future quantum calorimeter instruments. For this thesis we fabricated 7- and 15-pixel POSTS using Mo/Au TESs and gold absorbers, and moved from concept drawings on scraps of napkins to a 32 eV energy resolution at 1.5 keV, 7-pixel POST calorimeter.

  16. Technical progress report, November 1, 1979-October 31, 1980. Report NPL-865. [Univ. of Colorado

    SciTech Connect

    Not Available

    1980-11-01

    Work carried out at the Nuclear Physics Laboratory of the University of Colorado from November 1, 1979 through October 31, 1980 is summarized. Emphasis was on light ion reaction studies with the AVF cyclotron. The high resolution magnetic spectrometer has allowed studies of nucleon transfer, scattering, and charge exchange reactions throughout the periodic table. More experiments have been run with solid state counters this year than has been the case recently, as a broad range spectra of the light nuclei where only moderate resolution is demanded were examined. Several of these experiments were undertaken for more detailed studies of excitations seen with higher energy probes. Multiple coincidence measurements with neutron and gamma-ray counters have opened a new program in pre-equilibrium reactions and provided a new signature for the study of neutron-deficient final nuclei. The neutron time of flight program has expanded to higher excitation and to use of the (d,n) and (..cap alpha..,n) direct nucleon transfer reactions. Three important experiments were completed at the EPICS pion scattering facility at LAMPF, and other low energy pion scattering data were obtained at TRIUMF. Several (p,d) runs at high energies were accomplished, some with polarized beams at TRIUMF. High-lying structures in medium mass nuclei were studied by the (p,n) reaction at Indiana. Interest in the use of polarized beams has been prompted by the theoretical successes in this area. This interest has led to the study of one- and two-nucleon transfer reactions on a range of nuclei at the Los Alamos tandem and at IUCF.

  17. Generalized Reliability Methodology Applied to Brittle Anisotropic Single Crystals. Degree awarded by Washington Univ., 1999

    NASA Technical Reports Server (NTRS)

    Salem, Jonathan A.

    2002-01-01

    A generalized reliability model was developed for use in the design of structural components made from brittle, homogeneous anisotropic materials such as single crystals. The model is based on the Weibull distribution and incorporates a variable strength distribution and any equivalent stress failure criteria. In addition to the reliability model, an energy based failure criterion for elastically anisotropic materials was formulated. The model is different from typical Weibull-based models in that it accounts for strength anisotropy arising from fracture toughness anisotropy and thereby allows for strength and reliability predictions of brittle, anisotropic single crystals subjected to multiaxial stresses. The model is also applicable to elastically isotropic materials exhibiting strength anisotropy due to an anisotropic distribution of flaws. In order to develop and experimentally verify the model, the uniaxial and biaxial strengths of a single crystal nickel aluminide were measured. The uniaxial strengths of the <100> and <110> crystal directions were measured in three and four-point flexure. The biaxial strength was measured by subjecting <100> plates to a uniform pressure in a test apparatus that was developed and experimentally verified. The biaxial strengths of the single crystal plates were estimated by extending and verifying the displacement solution for a circular, anisotropic plate to the case of a variable radius and thickness. The best correlation between the experimental strength data and the model predictions occurred when an anisotropic stress analysis was combined with the normal stress criterion and the strength parameters associated with the <110> crystal direction.

  18. A Marriage of Minds: James R. Jacobs & Shinjoung Yeo Univ. of California-San Diego

    ERIC Educational Resources Information Center

    Library Journal, 2005

    2005-01-01

    Their personalities and backgrounds are very different, but James R. Jacobs and Shinjoung Yeo are passionate about the same causes: librarianship, open government, and empowerment through information. They balance each other. Yeo is focused, realistic, critical, and an excellent researcher. Her superhero alter ego is Wet Blanket Woman, able to…

  19. Early impact basins and the onset of plate tectonics. Ph.D. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Frey, H.

    1977-01-01

    The fundamental crustal dichotomy of the Earth (high and low density crust) was established nearly 4 billion years ago. Therefore, subductable crust was concentrated at the surface of the Earth very early in its history, making possible an early onset for plate tectonics. Simple thermal history calculations spanning 1 billion years show that the basin forming impact thins the lithosphere by at least 25%, and increases the sublithosphere thermal gradients by roughly 20%. The corresponding increase in convective heat transport, combined with the highly fractured nature of the thinned basin lithosphere, suggest that lithospheric breakup or rifting occurred shortly after the formation of the basins. Conditions appropriate for early rifting persisted from some 100,000,000 years following impact. We suggest a very early stage of high temperature, fast spreading "microplate" tectonics, originating before 3.5 billion years ago, and gradually stabilizing over the Archaean into more modern large plate or Wilson Cycle tectonics.

  20. Collider Physics: SDC/SSC liquified fiber calorimetry. [Physics Dept. , Texas A M Univ

    SciTech Connect

    White, J.T.; Huson, F.R.

    1992-01-01

    Most effort was directed toward the D-Zero experiment at Fermilab. Over 3 pb[sup [minus]1] of high-quality physics data have been obtained. Analysis of the results (wino-zino physics, squark physics), D-zero data acquisition systems efforts, and level-1 and level-2 trigger work are described. Other work concerned detector development for use at the SSC. This technology consists of using liquid scintillator-filled tubes as scintillating fibers for a calorimeter.'' The key issues were to demonstrate that the liquid fibers were sufficiently rad-hard and to demonstrate that fibers with sufficiently long attenuation length could be found to satisfy the resolution requirements; both constraints could be satisfied.

  1. Vehicle integration effects on hypersonic waveriders. M.S. Thesis - George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Cockrell, Charles Edward, Jr.

    1994-01-01

    The integration of a class of hypersonic high-lift configurations known as waveriders into hypersonic cruise vehicles was evaluated. Waveriders offer advantages in aerodynamic performance and propulsion/airframe integration (PAI) characteristics over conventional hypersonic shapes. A wind-tunnel model was developed which integrates realistic vehicle components with two waverider shapes, referred to as the 'straight-wing' and 'cranked-wing' shapes. Both shapes were conical-flow-derived waveriders at a design Mach number of 4.0. The cranked-wing shape was designed to provide advantages in subsonic performance and directional stability over conventional waveriders. Experimental data and limited computational fluid dynamics (CFD) predictions were obtained over a Mach number range of 2.3 to 4.63 at a Reynolds number of 2.0x10(exp 6) per foot. The CFD predictions and flow visualization data confirmed the shock attachment characteristics of the baseline waverider shapes and illustrated the waverider flow-field properties. Both CFD predictions and experimental data showed that no significant performance degradations occur at off-design Mach numbers for the waverider shapes and the integrated configurations. The experimental data showed that the effects of adding a realistic canopy were minimal. The effects of adding engine components were to increase the drag and thus degrade the aerodynamic performance of the configuration. A significant degradation in aerodynamic performance was observed when 0 degree control surfaces were added to close the blunt base of the waverider to a sharp trailing edge. A comparison of the fully-integrated waverider models to the baseline shapes showed that the performance was significantly degraded when all of the components were added to the waveriders. The fully-integrated configurations studied here do not offer significant performance advantages over conventional hypersonic vehicles, but still offer advantages in air-breathing propulsion integration. Additionally, areas are identified in this study where improvements could be made to enhance the performance. Both fully-integrated configurations are longitudinally unstable over the Mach number range studied for unpowered conditions. The cranked-wing fully-integrated configuration provided significantly better lateral-directional stability characteristics than the straight-wing configuration.

  2. Advanced propulsion for LEO-Moon transport. 3: Transportation model. M.S. Thesis - California Univ.

    NASA Technical Reports Server (NTRS)

    Henley, Mark W.

    1992-01-01

    A simplified computational model of low Earth orbit-Moon transportation system has been developed to provide insight into the benefits of new transportation technologies. A reference transportation infrastructure, based upon near-term technology developments, is used as a departure point for assessing other, more advanced alternatives. Comparison of the benefits of technology application, measured in terms of a mass payback ratio, suggests that several of the advanced technology alternatives could substantially improve the efficiency of low Earth orbit-Moon transportation.

  3. Optical measurements of soot in premixed flames. Ph.D. Thesis - California Univ.

    NASA Technical Reports Server (NTRS)

    Lyons, Valerie J.

    1988-01-01

    Two laser diagnostic techniques were used to measure soot volume fractions, number densities and soot particle radii in premixed propane/oxygen flat flames. The two techniques were two wavelength extinction, using 514.5 to 632.8 nm and 457.9 to 632.8 nm wavelength combinations, and extinction/scattering using 514.5 nm light. The flames were fuel rich and had cold gas velocities varying from 3.4 to 5.5 cm/s. Measurements were made at various heights above the sintered bronze, water colored flat flame burner with the equivalence ratio and cold gas velocity fixed. Also, measurements were made at a fixed height above the burner and fixed cold gas velocity while varying the equivalence ratio. Both laser techniques are based on the same underlying assumptions of particle size distribution and soot optical properties. Full Mie theory was used to determine the extinction coefficients and the scattering efficiencies. Temperature measurements in the flame were made using infrared radiometry and fine wire thermocouples. Good agreement between the two techniques in terms of soot particle radii, number density and volume fraction was found for intensity ratios between 0.1 and 0.8.

  4. Research in elementary particle physics. [Dept. of Physics and Astronomy, Louisiana State Univ,. Baton Rouge, Louisiana

    SciTech Connect

    Chan, L.H; Haymaker, R.; Imlay, R.; McNeil, R.; Metcalf, W.; Svoboda, R.

    1992-01-01

    Theoretical work on effective action expansion on an effective low; energy theory of hadron, dynamical symmetry breaking, and lattice gauge theories is described. The high-energy experimental group at Louisiana State University has analyzed data on a neutrino oscillation experiment at LAMPF. Preparations for the LSND neutrino experiment have stated. IMB data have also been analyzed. On the ZEUS electron n-proton colliding bean experiment, the production of the barrel calorimeter has been completed. Several modules of the calorimeter have been tested at Fermilab, and preparations for data taking are underway.

  5. TUNL XIX. Annual report, January 1-December 31, 1980. [North Carolina State Univ. activities at TUNL

    SciTech Connect

    1980-12-31

    Research performed by North Carolina State University personnel at TUNL is highlighted in this report, which is actually the complete TUNL progress report for 1980. Studies in the areas of neutron cross sections, neutron polarization, radiative capture, atomic physics and development activities are included. One may expect completed projects to be reported in physics journals or conference proceedings. (RWR)

  6. Studies of nuclei using radioactive beams. [Space Astronomy Lab. , Univ. of Florida, Gainesville, Florida

    SciTech Connect

    Piercey, R.B.

    1989-07-01

    The 12 month period from May 1988 to July 1989 represents the first full year of our 18 month pilot program in nuclear structure research. In this period, research was initiated to develop a capability for radioactive secondary beams at Argonne National Laboratory using the Atlas and the new Fragment Mass Analyzer (FMA), which is currently under construction. Two major new detector facilities are currently in the final stages of design and testing. The Large-Area, Scintillator Telescope (LAST) detector is fully operational and will be shipped to Argonne National Laboratory in August for fit-tests and in-beam calibrations. The first segments of a new sixteen-segment neutron multiplicity detector have been built and tested. The remaining segments are currently being constructed. Research was continued in the areas of (1) Coulomb excitation studies of rare earth and actinide nuclei; (2) In-beam, gamma-ray spectroscopy of nuclei in the mass 100 region, and (3) Advanced detector design. Several journal articles and abstracts were published or submitted for publication in the reporting period, and others are currently in preparation. Three graduate students participated in the program, one from the University of Florida and two from the Royal Institute of Technology, Stockholm, Sweden.

  7. Nitridation of silicon. M.S. Thesis Case Western Reserve Univ.

    NASA Technical Reports Server (NTRS)

    Shaw, N. J.

    1981-01-01

    Silicon powders with three levels of impurities, principally Fe, were sintered in He or H2. Non-densifying mechanisms of material transport were dominant in all cases. High purity Si showed coarsening in He while particle growth was suppressed in H2. Lower purity powder coarsened in both He and H2. The same three Si powders and Si /111/ single crystal wafers were nitrided in both N2 and N2/H2 atmospheres. Hydrogen increased the degree of nitridation of all three powders and the alpha/beta ratio of the lower purity powder. Some Si3N4 whiskers and open channels through the surface nitride layer were observed in the presence of Fe, correlating with the nitridation-enhancing effects of Fe. Thermodynamic calculations showed that when SiO2 is present on the Si, addition of H2 to the nitriding atmosphere decreases the amount of SiO2 and increases the partial pressure of Si-containing vapor species, that is, Si and SiO. Large amounts of NH3 and SiH4 were also predicted to form.

  8. On the Nature of Navier-stokes Turbulence. Ph.D. Thesis - Case Western Reserve Univ.

    NASA Technical Reports Server (NTRS)

    Deissler, Robert G.

    1989-01-01

    Several turbulent and nonturbulent solutions of the Navier-Stokes equations are obtained. The unaveraged equations are used numerically in conjunction with tools and concepts from nonlinear dynamics, including time series, phase portraits, Poincare sections, largest Liapunov exponents, power spectra, and strange attractors. Initially neighboring solutions for a low-Reynolds-number fully developed turbulence are compared. The solutions, separate exponentially with time, having a positive Liapunov exponent. Thus the turbulence is characterized as chaotic. In a search for solutions which contrast with the turbulent ones, the Reynolds number is reduced. Several qualitatively different flows are noted. These are, fully chaotic, complex period, weakly chaotic, simple periodic, and fixed-point. Of these, only the fully chaotic flows are classified as turbulent. Those flows have both a positive Liapunov exponent and Poincare sections without pattern. By contrast, the weakly chaotic flows have some pattern in their Poincare sections. The fixed-point and periodic flows are nonturbulent, since turbulence, is both time-dependent and aperiodic. Turbulent solutions are obtained in which energy cascades from large to small-scale motions. In general, the spectral energy transfer takes place between wavenumber bands that are considerably separated. The special transfer can occur either as a result of nonlinear turbulence self-interaction or by interaction of turbulence with mean gradients. Turbulent systems are compared with those studied in kinetic theory. The two types of systems are fundamentally different (continuous and dissipative as opposed to discrete and conservative), but there are similarities. For instance, both are nonlinear and show sensitive dependence on initial conditions. Also, the turbulent and molecular stress tensors are identical if the macroscopic velocities for the turbulent stress are replaced by molecular velocities.

  9. General Theory of the Double Fed Synchronous Machine. Ph.D. Thesis - Swiss Technological Univ., 1950

    NASA Technical Reports Server (NTRS)

    El-Magrabi, M. G.

    1982-01-01

    Motor and generator operation of a double-fed synchronous machine were studied and physically and mathematically treated. Experiments with different connections, voltages, etc. were carried out. It was concluded that a certain degree of asymmetry is necessary for the best utilization of the machine.

  10. Flight-management strategies for escape from microburst encounters. M.S. Thesis - George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Hinton, David A.

    1988-01-01

    An effort is underway by NASA, FAA, and industry to reduce the threat of convective microburst wind shear phenomena to aircraft. The goal is to develop and test a candidate set of strategies for recovery from inadvertent microburst encounters during takeoff. Candidate strategies were developed and evaluated using a fast-time simulation consisting of a simple point-mass performance model of a transport-category airplane and an analytical microburst model. The results indicate that the recovery strategy characteristics that best utilize available airplane energy include an initial reduction in pitch attitude to reduce the climb rate, followed by an increase in pitch up to the stick shaker angle of attack. The stick shaker angle of attack should be reached just as the airplane is exiting the microburst. The shallowest angle of climb necessary for obstacle clearance should be used. If the altitude is higher than necessary, an intentional descent to reduce the airspeed deceleration should be used. Of the strategies tested, two flight-path-angle based strategies had the highest recovery altitudes and the least sensitivity to variations in the encounter scenarios.

  11. Submillimeter wave survey of the galactic plane. Ph.D. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Cheung, L. H.

    1980-01-01

    The survey measured, over virtually the entire galactic plane, the distribution and basic physical conditions of the coolest dust component of the interstellar medium. The instrument designed for observations of extended, low surface brightness continuum emission consisted of a balloon borne, gyro stablized, 1.2 m Cassegrain telescope and a liquid cooled photometer. The design, integration, tests, and flight operation of the survey are presented.

  12. The sound of moving bodies. Ph.D. Thesis - Cambridge Univ.

    NASA Technical Reports Server (NTRS)

    Brentner, Kenneth Steven

    1990-01-01

    The importance of the quadrupole source term in the Ffowcs, Williams, and Hawkings (FWH) equation was addressed. The quadrupole source contains fundamental components of the complete fluid mechanics problem, which are ignored only at the risk of error. The results made it clear that any application of the acoustic analogy should begin with all of the source terms in the FWH theory. The direct calculation of the acoustic field as part of the complete unsteady fluid mechanics problem using CFD is considered. It was shown that aeroelastic calculation can indeed be made with CFD codes. The results indicate that the acoustic field is the most susceptible component of the computation to numerical error. Therefore, the ability to measure the damping of acoustic waves is absolutely essential both to develop acoustic computations. Essential groundwork for a new approach to the problem of sound generation by moving bodies is presented. This new computational acoustic approach holds the promise of solving many problems hitherto pushed aside.

  13. Analysis of objects in binary images. M.S. Thesis - Old Dominion Univ.

    NASA Technical Reports Server (NTRS)

    Leonard, Desiree M.

    1991-01-01

    Digital image processing techniques are typically used to produce improved digital images through the application of successive enhancement techniques to a given image or to generate quantitative data about the objects within that image. In support of and to assist researchers in a wide range of disciplines, e.g., interferometry, heavy rain effects on aerodynamics, and structure recognition research, it is often desirable to count objects in an image and compute their geometric properties. Therefore, an image analysis application package, focusing on a subset of image analysis techniques used for object recognition in binary images, was developed. This report describes the techniques and algorithms utilized in three main phases of the application and are categorized as: image segmentation, object recognition, and quantitative analysis. Appendices provide supplemental formulas for the algorithms employed as well as examples and results from the various image segmentation techniques and the object recognition algorithm implemented.

  14. Intermediate-energy nuclear theory. [Physics Dept. , Texas A and M Univ

    SciTech Connect

    Bryan, R.A.; VerWest, B.J.; Dominguez, C.A.

    1980-12-01

    Investigations on the nucleon-nucleon interaction at medium energies are reported. A major program to extract the experimental scattering amplitudes from the NN data over the 0 to 850 MeV energy range was begun. Special subprograms were set up to handle the large amount of data involved, and to estimate the total reaction cross sections. A program to project out partial-wave amplitudes of a tree-graph model for NN ..-->.. NN..pi.., in order to supplement the data in the higher angular momentum states, was completed. Work was also carried out on the three-body problem, particularly ..pi..-deuteron scattering, and on setting up an appropriate formalism for the two-to-three particle process NN ..-->.. NN..pi... In strong-interaction-related work, the pion-nucleon sigma term was investigated, and the dual-model prediction for factorizable three-hadron form factors was confirmed. Finally, a study of isospin as a dynamical operator in an extended space was continued. Individual summaries in this report are of only abstract length with no data. References are given.

  15. Experimental and Theoretical Studies of Interstellar Grains. Ph.D. Thesis - Maryland Univ., College Park, 1982

    NASA Technical Reports Server (NTRS)

    Nuth, J. A., III

    1981-01-01

    Steady state vibrational populations of SiO and CO in dilute black body radiation fields were calculated as a function of total pressure, kinetic temperature and chemical composition of the gas. Approximate calculations for polyatomic molecules are presented. Vibrational disequilibrium becomes increasingly significant as total pressure and radiation density decrease. Many regions of postulated grain formation are found to be far from thermal equilibrium before the onset of nucleation. Calculations based upon classical nucleation theory or equilibrium thermodynamics are expected to be of dubious value in such regions. Laboratory measurements of the extinction of small iron and magnetite grains were made from 195 nm to 830 nm and found to be consistent with predictions based upon published optical constants. This implies that small iron particles are not responsible for the 220 nm interstellar extinction features. Additional measurements are discussed.

  16. Finite Element A Posteriori Error Estimation for Heat Conduction. Degree awarded by George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Lang, Christapher G.; Bey, Kim S. (Technical Monitor)

    2002-01-01

    This research investigates residual-based a posteriori error estimates for finite element approximations of heat conduction in single-layer and multi-layered materials. The finite element approximation, based upon hierarchical modelling combined with p-version finite elements, is described with specific application to a two-dimensional, steady state, heat-conduction problem. Element error indicators are determined by solving an element equation for the error with the element residual as a source, and a global error estimate in the energy norm is computed by collecting the element contributions. Numerical results of the performance of the error estimate are presented by comparisons to the actual error. Two methods are discussed and compared for approximating the element boundary flux. The equilibrated flux method provides more accurate results for estimating the error than the average flux method. The error estimation is applied to multi-layered materials with a modification to the equilibrated flux method to approximate the discontinuous flux along a boundary at the material interfaces. A directional error indicator is developed which distinguishes between the hierarchical modeling error and the finite element error. Numerical results are presented for single-layered materials which show that the directional indicators accurately determine which contribution to the total error dominates.

  17. Characterization of the multifragment decay channel in highly excited nuclei. [Indiana Univ. , Bloomington, Indiana

    SciTech Connect

    de Souza, R.T.

    1992-10-01

    Characteristics of multifragment decay in heavy-ion induced reactions at intermediate energies are explored. Evolution of the timescale for emission of intermediate mass fragments (IMF: 3[le]Z[le]20) is investigated. Fragments associated with central collisions in the reactions [sup 36]Ar + [sup 197]Au at E/A = 50, 80, and 110 MeV are emitted on an extremely fast timescale, [tau] [le] 75 fm/c, comparable to the transit time of the projectile past the target nucleus. With increasing incident energy, mean fragment emission times decrease, consistent with statistical decay from highly excited systems or fast dynamical processes. To examine the importance of expansion effects in multifragmentation, the transverse kinetic energy of fragments was investigated. Evidence for expansion effects in the system [sup 36]Ar + [sup 197]Au at E/A = 50, 80, and 110 MeV was indicated by the charge dependence of the mean isotropic kinetic energy. At the highest incident energy the data suggest the onset of volume emission. Construction and performance of low-threshold high-resolution detector telescopes is discussed. Three-body Coulomb trajectory calculations are being used to probe kinematical correlations associated with neck emission of IMFs during fission. Initial design and testing of position sensitive parallel plate avalanche counters for upcoming ternary fission experiments is discussed.

  18. Liver Rapid Reference Set Application ( #2): Lubman - Univ of Michigan (2010) — EDRN Public Portal

    Cancer.gov

    We are requesting the reference set, which includes 50 HCC cases and 50 cirrhotic controls. In our preliminary study, AFP had a AUROC of 0.66 while the AUROC for the 5 glycoproteins was 0.81. The sensitivity and specificity for the 5 glycoproteins was 79% and 72% at the point that maximizes sensitivity+specificity in the ROC curve, and it was 79% and 35%, respectively, for AFP at the same point in the ROC curve. The reference set will allow us to determine the best performance of the 5 glycoproteins by themselves or whether their combination has a better sensitivity and/or specificity and AUROC. While a direct comparison with AFP will be made, the reference set will not allow a robust comparison due to the low sample size. If the glycoproteins are complementary or have better performance than AFP, then the next step would be to test them in the entire phase 2 hepatocellular carcinoma set.

  19. Liver Rapid Reference Set Application (#1): David Lubman - Univ of Michigan (2009) — EDRN Public Portal

    Cancer.gov

    We are requesting the reference set, which includes 50 HCC cases and 50 cirrhotic controls. In our preliminary study, AFP had a AUROC of 0.66 while the AUROC for the 5 glycoproteins was 0.81. The sensitivity and specificity for the 5 glycoproteins was 79% and 72% at the point that maximizes sensitivity+specificity in the ROC curve, and it was 79% and 35%, respectively, for AFP at the same point in the ROC curve. The reference set will allow us to determine the best performance of the 5 glycoproteins by themselves or whether their combination has a better sensitivity and/or specificity and AUROC. While a direct comparison with AFP will be made, the reference set will not allow a robust comparison due to the low sample size. If the glycoproteins are complementary or have better performance than AFP, then the next step would be to test them in the entire phase 2 hepatocellular carcinoma set.

  20. Liver Full Reference Set Application :Timothy Block - Drexel Univ (2010) — EDRN Public Portal

    Cancer.gov

    The goal of this application is to determine if the levels of serum GP73 and fucosylated kininogen/acute phase proteins can be used to detect hepatocellular carcinoma (HCC) in the background of liver cirrhosis. The use of the validation set would allow us to directly compare GP73 and fucosylated markers against AFP, AFP-L3 and DCP as well as test them in combination with these markers

  1. Connectivity across the Caribbean Sea: DNA barcoding and morphology unite an enigmatic fish larva from the Florida straits with a new species of sea bass from deep reefs off Curaçao.

    PubMed

    Baldwin, Carole C; Johnson, G David

    2014-01-01

    Integrative taxonomy, in which multiple disciplines are combined to address questions related to biological species diversity, is a valuable tool for identifying pelagic marine fish larvae and recognizing the existence of new fish species. Here we combine data from DNA barcoding, comparative morphology, and analysis of color patterns to identify an unusual fish larva from the Florida Straits and demonstrate that it is the pelagic larval phase of a previously undescribed species of Liopropoma sea bass from deep reefs off Curaçao, southern Caribbean. The larva is unique among larvae of the teleost family Serranidae, Tribe Liopropomini, in having seven elongate dorsal-fin spines. Adults of the new species are similar to the golden bass, Liopropoma aberrans, with which they have been confused, but they are distinct genetically and morphologically. The new species differs from all other western Atlantic liopropomins in having IX, 11 dorsal-fin rays and in having a unique color pattern-most notably the predominance of yellow pigment on the dorsal portion of the trunk, a pale to white body ventrally, and yellow spots scattered across both the dorsal and ventral portions of the trunk. Exploration of deep reefs to 300 m using a manned submersible off Curaçao is resulting in the discovery of numerous new fish species, improving our genetic databases, and greatly enhancing our understanding of deep-reef fish diversity in the southern Caribbean. Oh the mother and child reunion is only a moment away. Paul Simon.

  2. Manifestation of screening effects and A-O covalency in the core level spectra of A site elements in the ABO3 structure of Ca1-xSrxRuO3

    NASA Astrophysics Data System (ADS)

    Singh, Ravi Shankar; Maiti, Kalobaran

    2007-08-01

    We investigate the evolution of Ca2p and Sr3d core level spectra in Ca1-xSrxRuO3 using photoemission spectroscopy. Core level spectra in this system exhibit multiple features and unusual evolution with the composition and temperatures. Analysis of the core level spectra in conjunction with the band structure results indicates final state effects due to different core hole screening channels. Such screening in the photoemission final states can be attributed to the large A-O covalency in these systems. Changes in the core level spectra with temperature and composition suggest significant modification in A-O (A=Ca/Sr) covalency in Ca-dominated samples, which gradually reduces with the increase in Sr content and becomes insignificant in SrRuO3 . This study thus provides a direct evidence of cation-oxygen covalency and its evolution with temperature, which may be useful in understanding the unusual ground state properties of these materials.

  3. Expression of Cry1Ac in transgenic tobacco plants under the control of a wound-inducible promoter (AoPR1) isolated from Asparagus officinalis to control Heliothis virescens and Manduca sexta.

    PubMed

    Gulbitti-Onarici, Selma; Zaidi, Mohsin Abbas; Taga, Ibrahim; Ozcan, Sebahattin; Altosaar, Illimar

    2009-07-01

    Expression of cry1Ac gene from Bacillus thuringiensis (Bt) was evaluated under the control of a wound-inducible AoPR1 promoter from Asparagus officinalis in transgenic tobacco plants. The leaves of transgenic plants were mechanically wounded to evaluate the activity of the AoPR1 promoter in driving the expression of Cry1Ac protein at the wound site. Our results indicate that mechanical wounding of transgenic plants was effective in inducing the expression of Cry1Ac protein. As a result of this induction, the accumulated levels of Cry1Ac protein increased during 6-72 h post-wounding period. The leaves of transgenic tobacco plants were evaluated for resistance against Heliothis virescens and Manduca sexta in insect bioassays in two different ways. The detached tobacco leaves were either fed directly to the insect larvae or they were first mechanically wounded followed by a 72 h post-wounding feeding period. Complete protection of mechanically wounded leaves of transgenic plants was observed within 24 h of the bioassay. The leaves of transgenic plants fed directly (without pre-wounding) to the larvae achieved the same level of protection between 24 and 72 h of the bioassay.

  4. Compilação de dados atômicos e moleculares do UV ao IV próximo para uso em síntese espectral

    NASA Astrophysics Data System (ADS)

    Coelho, P.; Barbuy, B.; Melendez, J.; Allen, D. M.; Castilho, B.

    2003-08-01

    Espectros sintéticos são utéis em uma grande variedade de aplicações, desde análise de abundâncias em espectros estelares de alta resolução ao estudo de populações estelares em espectros integrados. A confiabilidade de um espectro sintético depende do modelo de atmosfera adotado, do código de formação de linhas e da qualidade dos dados atômicos e moleculares que são determinantes no cálculo das opacidades da fotosfera. O nosso grupo no departamento de Astronomia no IAG tem utilizado espectros sintéticos há mais de 15 anos, em aplicações voltadas principalmente para a análise de abundâncias de estrelas G, K e M e populações estelares velhas. Ao longo desse tempo, as listas de linhas vieram sendo construídas e atualizadas continuamente, e alguns acréscimos recentes podem ser citados: Castilho (1999, átomos e moléculas no UV), Schiavon (1998, bandas moleculares de TiO) e Melendez (2001, átomos e moléculas no IV próximo). Com o intuito de calcular uma grade de espectros do UV ao IV próximo para uso no estudo de populações estelares velhas, se fazia necessário compilar e homogeneizar as diversas listas em apenas uma lista atômica e uma molecular. Nesse processo, a nova lista compilada foi correlacionada com outras bases de dados (NIST, Kurucz Database, O' Brian et al. 1991) para atualização dos parâmetros que caracterizam a transição atômica (comprimento de onda, log gf e potencial de excitação). Adicionalmente as constantes de interação C6 foram calculadas segundo a teoria de Anstee & O'Mara (1995) e artigos posteriores. As bandas moleculares de CH e CN foram recalculadas com o programa LIFBASE (Luque & Crosley 1999). Nesse poster estão detalhados os procedimentos citados acima, as comparações entre espectros calculados com as novas listas e espectros observados em alta resolução do Sol e de Arcturus, e uma análise do impacto decorrente da utilização de diferentes modelos de atmosfera no espectro sintético. Ao

  5. The maximum overlap method: A general and efficient scheme for reducing basis sets. Application to the generation of approximate AO's for the 3 d transition metal atoms and ions

    NASA Astrophysics Data System (ADS)

    Francisco, E.; Seijo, L.; Pueyo, L.

    1986-07-01

    The method of maximum overlap, often applied to the problem of basis set reduction, is formulated in terms of weighted least squares with orthogonality restrictions. An analytical solution for the linear parameters of the reduced set is given. In this form, the method is a general and efficient scheme for reducing basis sets. As an application, orthogonal radial wavefunctions of the STO type have been obtained for the 3 d transition metal atoms and ions by simulation of the high-quality sets of Clementi and Roetti. The performance of the reduction has been evaluated by examining several one- and two-electron interactions. Results of these tests reveal that the new functions are highly accurate simulations of the reference AO's. They appear to be appropriate for molecular and solid state calculations.

  6. Genetic data on nine STRs (CSF1PO, TPOX, THO1, F13AO1, FESFPS, vWA, D16S539, D7S820 and D13S317) and two VNTRs (D1S80 and D17S5) in Rosario population, Santa Fe Argentine.

    PubMed

    Tenaglia, Mariano; Scollo, Adriana; Tripaldi, Regina; Grappiolo, Irene; Perichón, Armando M

    2004-05-10

    Allele frequencies for nine short tandem repeats (STRs) loci (CSF1PO, TPOX, THO1, F13AO1, FES/FPS, vWA, D16S539, D7S820 and D13S317) and two variable number tandem repeats (VNTRs) were obtained from a sample of 270 unrelated individuals born in the Rosario city, Santa Fe province of Argentina.

  7. On-sky AO test bench

    NASA Astrophysics Data System (ADS)

    Brousseau, Denis; Thibault, Simon; Lavigne, Jean-François; Véran, Jean-Pierre

    2016-07-01

    With the upcoming construction of ELTs, several existing technologies are being pushed beyond their performance limit and it became essential to develop and evaluate alternatives. We present a specifically designed focal plane box which will allow to evaluate, directly on-sky, the performance of a number of next generation adaptive optics related technologies The system will able us to compare the performance of several new wavefront sensors in contrast to a Shack-Hartman wavefront sensor. The system has been designed for the "Observatoire du Mont Mégantic" (OMM) which hosts a telescope having a 1.6-meter diameter primary. The OMM telescope, located halfway between Montreal and Quebec City, is known to be an excellent location to develop and test precursor instruments which can then be upscaled to larger telescopes (ex. SPIOMM which led to SITELLE at the CFHT). We present the results of the first run made at the telescope and also identify problems that were encountered. We also propose a series of modifications to the system that will help to solve these issues.

  8. Life and Death Decision Analysis.

    DTIC Science & Technology

    1979-12-01

    LIFE SMOKING: CANCER, EMPHYSEMA, SHORTENED LIFE BATHING: FALLING, ELECTROCUTION CONTRACEPTION: DEATH , ILLNESS PREGNANCY: DEATH , ILLNESS ABORTION ...economic effect is the one with the highest probability of causing my death . -13- EXPECTED NET SYSTEM DESIGN BENEFIT TO ME DEATH DEATH (r A(excluding death ...0-AO81 424 STANFORD UNIV CALIF DEPT OF ENGtNEERING-ECONOM!C SYSTEMS F/6 12/1 LIFE ANDI DEATH DECISION ANALYSIS.CU) DEC 79 R A HOWARD N0OOIN-79-C-0036

  9. Organizational and Non-Organizational Influences on Job Attitudes of Part-Time and Full-Time Employees.

    DTIC Science & Technology

    1980-02-01

    AD-AO82 568 ILLINOIS UNIV AT URBANA-CHAMPAIGN DEPT OF PSYCHOLOGY F/S 5/10 ORGANIZATIONAL AND NON-ORGANIZATIONAL INFLUENCES ON JOB ATTITUD-.ETC(U) FEB...Department of Psychology Urbana -Champaign II ~ ~ 1. 7-~ c~.6 so03..31� ORGANIZATIONAL AND NON-ORGANIZATIONAL INFLUENCES ON JOB ATTITUDES OF PART-TIME...organization. Finally, relations of non-organizational social influences with measures of psychological attachment were equivalently high for both part

  10. Memory Organization and Search Processes for Narratives.

    DTIC Science & Technology

    1980-04-01

    AD-AO8 141 YALE UNIV NEW HAVEN CT DEPT OF COMPUTER SCIENCE F/6 5/7 MEMORY ORGANIZATION AND SEARCH PROCESSES FOR NARRATIVES.(U) APR 80 M 6 DYER, W O ... o ........... . . .... Memory Organization and Search...all a hoax. Some representative BORIS I/ O appears below. The questions are verbatim input to BORIS and the answers are verbatim computer output

  11. Galactic background maps at 3.93 and 6.55 MHz. M.S. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Novaco, J. C.

    1973-01-01

    The Radio Astronomy Explorer Satellite (RAE-1), its hardware and its data processing are discussed. The data from the prime mapping antenna are discussed with emphasis on the problems involved in reducing the data. Particular attention is drawn to two problems - receiver instability and ground breakthrough - and their influence on the data. Galactic background maps of the nonthermal radiation at 3.93 and 6.55 MHz are produced. It is demonstrated that the positional uncertainity of the maps is about 20 deg. The maps at 3.93 and 6.55 MHz are compared to two ground based maps made at higher frequencies that are smoothed to the larger RAE antenna patterns.

  12. Spherical Earth analysis and modeling of lithospheric gravity and magnetic anomalies. Ph.D. Thesis - Purdue Univ.

    NASA Technical Reports Server (NTRS)

    Vonfrese, R. R. B.; Hinze, W. J.; Braile, L. W.

    1980-01-01

    A comprehensive approach to the lithospheric analysis of potential field anomalies in the spherical domain is provided. It has widespread application in the analysis and design of satellite gravity and magnetic surveys for geological investigation.

  13. Very Long Baseline Interferometry Applied to Polar Motion, Relativity and Geodesy. Ph.D. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Ma, C.

    1978-01-01

    The causes and effects of diurnal polar motion are described. An algorithm is developed for modeling the effects on very long baseline interferometry observables. Five years of radio-frequency very long baseline interferometry data from stations in Massachusetts, California, and Sweden are analyzed for diurnal polar motion. It is found that the effect is larger than predicted by McClure. Corrections to the standard nutation series caused by the deformability of the earth have a significant effect on the estimated diurnal polar motion scaling factor and the post-fit residual scatter. Simulations of high precision very long baseline interferometry experiments taking into account both measurement uncertainty and modeled errors are described.

  14. Finite Element Analysis of Active and Sensory Thermopiezoelectric Composite Materials. Degree awarded by Northwestern Univ., Dec. 2000

    NASA Technical Reports Server (NTRS)

    Lee, Ho-Jun

    2001-01-01

    Analytical formulations are developed to account for the coupled mechanical, electrical, and thermal response of piezoelectric composite materials. The coupled response is captured at the material level through the thermopiezoelectric constitutive equations and leads to the inherent capability to model both the sensory and active responses of piezoelectric materials. A layerwise laminate theory is incorporated to provide more accurate analysis of the displacements, strains, stresses, electric fields, and thermal fields through-the-thickness. Thermal effects which arise from coefficient of thermal expansion mismatch, pyroelectric effects, and temperature dependent material properties are explicitly accounted for in the formulation. Corresponding finite element formulations are developed for piezoelectric beam, plate, and shell elements to provide a more generalized capability for the analysis of arbitrary piezoelectric composite structures. The accuracy of the current formulation is verified with comparisons from published experimental data and other analytical models. Additional numerical studies are also conducted to demonstrate additional capabilities of the formulation to represent the sensory and active behaviors. A future plan of experimental studies is provided to characterize the high temperature dynamic response of piezoelectric composite materials.

  15. Integrating Oil Debris and Vibration Measurements for Intelligent Machine Health Monitoring. Degree awarded by Toledo Univ., May 2002

    NASA Technical Reports Server (NTRS)

    Dempsey, Paula J.

    2003-01-01

    A diagnostic tool for detecting damage to gears was developed. Two different measurement technologies, oil debris analysis and vibration were integrated into a health monitoring system for detecting surface fatigue pitting damage on gears. This integrated system showed improved detection and decision-making capabilities as compared to using individual measurement technologies. This diagnostic tool was developed and evaluated experimentally by collecting vibration and oil debris data from fatigue tests performed in the NASA Glenn Spur Gear Fatigue Rig. An oil debris sensor and the two vibration algorithms were adapted as the diagnostic tools. An inductance type oil debris sensor was selected for the oil analysis measurement technology. Gear damage data for this type of sensor was limited to data collected in the NASA Glenn test rigs. For this reason, this analysis included development of a parameter for detecting gear pitting damage using this type of sensor. The vibration data was used to calculate two previously available gear vibration diagnostic algorithms. The two vibration algorithms were selected based on their maturity and published success in detecting damage to gears. Oil debris and vibration features were then developed using fuzzy logic analysis techniques, then input into a multi sensor data fusion process. Results show combining the vibration and oil debris measurement technologies improves the detection of pitting damage on spur gears. As a result of this research, this new diagnostic tool has significantly improved detection of gear damage in the NASA Glenn Spur Gear Fatigue Rigs. This research also resulted in several other findings that will improve the development of future health monitoring systems. Oil debris analysis was found to be more reliable than vibration analysis for detecting pitting fatigue failure of gears and is capable of indicating damage progression. Also, some vibration algorithms are as sensitive to operational effects as they are to damage. Another finding was that clear threshold limits must be established for diagnostic tools. Based on additional experimental data obtained from the NASA Glenn Spiral Bevel Gear Fatigue Rig, the methodology developed in this study can be successfully implemented on other geared systems.

  16. Progress report on research program in elementary particle theory, 1979-1980. [Univ. of Texas at Austin

    SciTech Connect

    Sudarshan, E.C.G.; Ne'eman, Y.

    1980-01-01

    A qualitative description is given of research in the following areas: particle physics in relativistic astrophysics and cosmology; phenomenology of weak and electromagnetic interactions; strong interaction physics and quark-parton physics; quantum mechanics, quantum field theory, and fundamental problems; and groups, gauges, and grand unified theories. Reports on this work have already been published, or will be, when it is completed. (RWR)

  17. Arbitrarily Curved and Twisted Space Beams. Ph.D. Thesis - Va. Polytech. Inst. and State Univ.; [Elastic Deformation, Stress Analysis

    NASA Technical Reports Server (NTRS)

    Hunter, W. F.

    1974-01-01

    A derivation of the equations which govern the deformation of an arbitrarily curved and twisted space beam is presented. These equations differ from those of the classical theory in that (1) extensional effects are included; (2) the strain-displacement relations are derived; and (3) the expressions for the stress resultants are developed from the strain displacement relations. It is shown that the torsional stress resultant obtained by the classical approach is basically incorrect except when the cross-section is circular. The governing equations are given in the form of first-order differential equations. A numerical algorithm is given for obtaining the natural vibration characteristics and example problems are presented.

  18. One-Dimensional Shock Wave Formation by an Accelerating Piston. Ph.D. Thesis - Ohio State Univ.

    NASA Technical Reports Server (NTRS)

    Mann, M. J.

    1970-01-01

    The formation of a shock wave by a solid accelerating piston was studied. A theoretical solution using the method of characteristics for a perfect gas showed that a complex wave system exists, and that the compressed gas can have large gradients in temperature, density and entropy. Experiments were performed with a piston tube where piston speed, shock speed and pressure were measured. The comparison of theory and experiment was good.

  19. Adhesion of a bimetallic interface. Ph.D. Thesis - Case Western Reserve Univ.; [for Al, Mg, and Zn

    NASA Technical Reports Server (NTRS)

    Ferrante, J.

    1978-01-01

    The Hohenberg-Kohn and Kohn-Sham formalisms are used to examine binding (binding energy as a function of separation) for combinations of the simple metals Al(111), Zn(0001), Mg(0001), and Na(110) in contact. Similar metal contacts between Al, Zn, Mg, and Na are examined self-consistently in an ab initio calculation using the Kohn-Sham formalism. Crystallinity is included using the Aschroft pseudopotential via first order perturbation theory for the electron-ion interaction; and the ion-ion interaction is included exactly via a lattice sum. Binding energy was determined both in the local-density approximation and including gradient corrections to the exchange and correlation energy. Binding was found in all cases. In dissimilar metal contacts, interfacial bonding was greater than that in the weaker material predicting the possibility of metallic transfer. The nonzero position of the energy minimum in like metal contacts is explained in terms of consistency between the Ashcroft pseudopotential and the bulk charge density. Good agreement with experimental surface energies is obtained in the self-consistent calculation when nonlocal terms are included.

  20. Fine Structure in 3C 120 and 3C 84. Ph.D. Thesis - Maryland Univ., 24 Aug. 1976

    NASA Technical Reports Server (NTRS)

    Hutton, L. K.

    1976-01-01

    Seven epochs of very long baseline radio interferometric observations of the Seyfert galaxies 3C 120 and 3C 84, at 3.8-cm wave length using stations at Westford, Massachusetts, Goldstone, California, Green Bank, West Virginia, and Onsala, Sweden, have been analyzed for source structure. An algorithm for reconstructing the brightness distribution of a spatially confined source from fringe amplitude and so called closure phase data has been developed and successfully applied to artificially generated test data and to data on the above mentioned sources. Over the two year time period of observation, 3C 120 was observed to consist of a double source showing apparent super relativistic expansion and separation velocities. The total flux changes comprising one outburst can be attributed to one of these components. 3C 84 showed much slower changes, evidently involving flux density changes in individual stationary components rather than relative motion.

  1. A federated information management system for the Deep Space Network. M.S. Thesis - Univ. of Southern California

    NASA Technical Reports Server (NTRS)

    Dobinson, E.

    1982-01-01

    General requirements for an information management system for the deep space network (DSN) are examined. A concise review of available database management system technology is presented. It is recommended that a federation of logically decentralized databases be implemented for the Network Information Management System of the DSN. Overall characteristics of the federation are specified, as well as reasons for adopting this approach.

  2. Theoretical studies in medium-energy nuclear and hadronic physics. [Indiana Univ. Nuclear Theory Center and Department of Physics

    SciTech Connect

    Horowitz, C J; Macfarlane, M H; Matsui, T; Serot, B D

    1993-01-01

    A proposal for theoretical nuclear physics research is made for the period April 1, 1993 through March 31, 1996. Research is proposed in the following areas: relativistic many-body theory of nuclei and nuclear matter, quasifree electroweak scattering and strange quarks in nuclei, dynamical effects in (e,e[prime]p) scattering at large momentum transfer, investigating the nucleon's parton sea with polarized leptoproduction, physics of ultrarelativistic nucleus[endash]nucleus collisions, QCD sum rules and hadronic properties, non-relativistic models of nuclear reactions, and spin and color correlations in a quark-exchange model of nuclear matter. Highlights of recent research, vitae of principal investigators, and lists of publications and invited talks are also given. Recent research dealt primarily with medium-energy nuclear physics, relativistic theories of nuclei and the nuclear response, the nuclear equation of state under extreme conditions, the dynamics of the quark[endash]gluon plasma in relativistic heavy-ion collisions, and theories of the nucleon[endash]nucleon force.

  3. Design of the Wind Tunnel Model Communication Controller Board. Degree awarded by Christopher Newport Univ. on Dec. 1998

    NASA Technical Reports Server (NTRS)

    Wilson, William C.

    1999-01-01

    The NASA Langley Research Center's Wind Tunnel Reinvestment project plans to shrink the existing data acquisition electronics to fit inside a wind tunnel model. Space limitations within a model necessitate a distributed system of Application Specific Integrated Circuits (ASICs) rather than a centralized system based on PC boards. This thesis will focus on the design of the prototype of the communication Controller board. A portion of the communication Controller board is to be used as the basis of an ASIC design. The communication Controller board will communicate between the internal model modules and the external data acquisition computer. This board is based around an Field Programmable Gate Array (FPGA), to allow for reconfigurability. In addition to the FPGA, this board contains buffer Random Access Memory (RAM), configuration memory (EEPROM), drivers for the communications ports, and passive components.

  4. Le conte Africain: L'univers de l'oralite dans le systeme de l'enseignement

    NASA Astrophysics Data System (ADS)

    Belpassi, Paola

    1994-05-01

    According to current interpretations, the stories preserved in the African oral tradition constitute a rich source of themes for the purposes of moral education. The stories focusing on the relationship between brother and sister, for example, develop the theme of how each individual must find a balance between consanguineous and marital relationships. The author also explores other keys to the interpretation of these stories and argues that they could profitably be used within the framework of a multicultural educational programme, on account of their linguistic, narrative and thematic richness.

  5. [Reaction mechanism studies of heavy ion induced nuclear reactions]. [Dept. of Chemistry and Biochemistry, Univ. of Maryland, College Park, Maryland

    SciTech Connect

    Mignerey, A.C.

    1993-02-01

    Completed work is summarized on the topics of excitation energy division in deep-inelastic reactions and the onset of multifragmentation in La-induced reactions at E/A = 45 MeV. Magnetic fields are being calculated for the PHOBOS detector system, a two-arm multiparticle spectrometer for studying low-transverse-momentum particles produced at the Relativistic Heavy Ion Collider. The Maryland Forward Array is being developed for detection of the reaction products from very peripheral collisions; it consists of two individual units of detectors: the annular silicon detector in front and the plastic phoswich detector at back.

  6. Effects of Control Hysteresis on the Space Shuttle Orbiter's Entry. M.S. Thesis - George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Powell, R. W.

    1975-01-01

    There are six degree-of-freedom simulations of the space shuttle orbiter entry with aerodynamic control hysteresis conducted on the NASA Langley Research Center interactive simulator known as the Automatic Reentry Flight Dynamics Simulator. These were performed to determine if the presence of aerodynamic control hysteresis would endanger the mission, either by making the vehicle unable to maintain proper attitude for a safe entry, or by increasing the amount of the reaction control system's fuel consumption beyond that carried.

  7. Combustion of solid carbon rods in zero and normal gravity. Ph.D. Thesis - Toledo Univ., Ohio

    NASA Technical Reports Server (NTRS)

    Spuckler, C. M.

    1981-01-01

    In order to investigate the mechanism of carbon combustion and to assess the importance of gravitational induced convection on the process, zero and normal gravity experiments were conducted in which spectroscopic carbon rods were resistance ignitied and burned in dry oxygen environments. In the zero-gravity drop tower tests, a blue flame surrounded the rod, showing that a gas phase reaction in which carbon monoxide was oxidized to carbon dioxide was taking place. The ratio of flame diameter to rod diameter was obtained as a function of time. It was found that this ratio was inversely proportional to both the oxygen pressure and the rod diameter. In the normal gravity tests, direct mass spectrometric sampling was used to measure gas phase concentrations. The gas sampling probe was positioned near the circumference of a horizontally mounted 0.615 cm diameter carbon rod, either at the top or at angles of 45 deg to 90 deg from the top, and yielded concentration profiles of CO2, CO, and O2 as a function of distance from the surface. The mechanism controlling the combustion process was found to change from chemical process control at the 90 deg and 45 deg probe positions to mass transfer control at the 0 deg probe position at the top of the rod. Under the experimental conditions used, carbon combustion was characterized by two surface reactions, 2C + O2 yields 2CO and CO2 + C yields 2CO, and a gas phase reaction, 2CO + O2 yields 2CO2.

  8. An investigation of satellites to the resonance lines in some hydrogen-like ions. Ph.D. Thesis - Colo. Univ.

    NASA Technical Reports Server (NTRS)

    Jalufka, N. W.

    1972-01-01

    An experimental and theoretical investigation was conducted on the origin of satellite to resonance lines of the hydrogen-like ions of boron, carbon, and nitrogen. A theta pinch was employed with a grazing incidence spectrograph to measure the wavelengths of the satellites. The spectroscopic data also provided an estimate of the satellite/resonance line intensity ratio. Wavelengths of spectral lines due to transition from doubly excited states were calculated by a Hartree-Fock computer program. Wave functions were also calculated and were used to obtain the oscillator strengths of the transitions. Experimental work confirmed that the lines investigated were not satellites but were due to highly ionized argon which was present as an impurity in the filling gas.

  9. Creep-Rupture Data Analysis - Engineering Application of Regression Techniques. Ph.D. Thesis - North Carolina State Univ.

    NASA Technical Reports Server (NTRS)

    Rummler, D. R.

    1976-01-01

    The results are presented of investigations to apply regression techniques to the development of methodology for creep-rupture data analysis. Regression analysis techniques are applied to the explicit description of the creep behavior of materials for space shuttle thermal protection systems. A regression analysis technique is compared with five parametric methods for analyzing three simulated and twenty real data sets, and a computer program for the evaluation of creep-rupture data is presented.

  10. The physiological effects of simultaneous exposures to heat and vibration. Ph.D. Thesis - California Univ., Berkeley

    NASA Technical Reports Server (NTRS)

    Spaul, W. A.

    1983-01-01

    Determination of the effects of exposure to vibration on the body's ability to handle heat stress, and, if so, identification of the specific vibration parameters (frequency and intensity) for both whole-body (wbv) and segmental-body vibration (sbv) that would have the most detrimental effect on the body's ability to maintain thermal homeostasis were studied. Rectal and skin temperatures, heart rates, localized sweat rates, arm-segment blood perfusion rates, respiration rates, oxygen uptakes, and respiratory exchange ratios were measured in six men (22 to 33 yr) during simultaneous exposures to heat and vibration - either wbv or sbv, and during a heated 50 min recovery period. The heat conditions were T (sub db) = 43.5 + or - 0.5 C (mean + or S.E.M.), and RH = 20 + or - 4%. All vibration exposures were divided into two exposure conditions - identical frequencies but at a high intensity (HI) and a low intensity (LI) level. The HI wbv exposure was for 25 min/day at 5 Hz, 0.37 g-rms; 10 Hz, 0.46 g-rms; 16 Hz, 0.72 g-rms; 30 Hz, 1.40 g-rms; 80 Hz, 3.70 g-rms. The LI wbv exposure was for 2.5 hr/day at the same frequencies but at the following accelerations: 0.14 g-rms; 0.18 g-rms; 0.28 g-rms; 0.55 g-rms; 1.44 g-rms. During the sbv the subject stood and grasped a vibrating, in the Z-axis, hand grip with both hands.

  11. The Impact of Educational Interventions on Organizational Culture at an Urban Federal Agency. Ph.D. Thesis - Old Dominion Univ.

    NASA Technical Reports Server (NTRS)

    Mckenzie, Janet Myrick

    1994-01-01

    This study on the impact of educational interventions on organizational culture is an evaluation of a major educational initiative undertaken by an urban federal agency, namely the National Aeronautics and Space Administration's Langley Research Center (NASA-LaRC). The design of this educational evaluation captures the essence of NASA-LaRC's efforts to continue its distinguished and international stature in the aeronautical research community following the Challenger tragedy. More specifically, this study is an evaluation of the educational initiative designed to ameliorate organizational culture via educational interventions, with emphasis on communications, rewards and recognition, and career development. After completing a review of the related literature, chronicling the educational initiative, interviewing senior managers and employees, and critically examining thousands of free responses on employee perceptions of organizational culture, it is found that previous definitions of organizational culture are more accurately classified as manifestations of organizational culture. This research has endeared to redefine 'organizational culture' by offering a more accurate and diagnostic perspective.

  12. Design and Performance Calculations of a Propeller for Very High Altitude Flight. Degree awarded by Case Western Univ.

    NASA Technical Reports Server (NTRS)

    Koch, L. Danielle

    1998-01-01

    Reported here is a design study of a propeller for a vehicle capable of subsonic flight in Earth's stratosphere. All propellers presented were required to absorb 63.4 kW (85 hp) at 25.9 km (85,000 ft) while aircraft cruise velocity was maintained at Mach 0.40. To produce the final design, classic momentum and blade-element theories were combined with two and three-dimensional results from the Advanced Ducted Propfan Analysis Code (ADPAC), a numerical Navier-Stokes analysis code. The Eppler 387 airfoil was used for each of the constant section propeller designs compared. Experimental data from the Langley Low-Turbulence Pressure Tunnel was used in the strip theory design and analysis programs written. The experimental data was also used to validate ADPAC at a Reynolds numbers of 60,000 and a Mach number of 0.20. Experimental and calculated surface pressure coefficients are compared for a range of angles of attack. Since low Reynolds number transonic experimental data was unavailable, ADPAC was used to generate two-dimensional section performance predictions for Reynolds numbers of 60,000 and 100,000 and Mach numbers ranging from 0.45 to 0.75. Surface pressure coefficients are presented for selected angles of attack. in addition to the variation of lift and drag coefficients at each flow condition. A three-dimensional model of the final design was made which ADPAC used to calculated propeller performance. ADPAC performance predictions were compared with strip-theory calculations at design point. Propeller efficiency predicted by ADPAC was within 1.5% of that calculated by strip theory methods, although ADPAC predictions of thrust, power, and torque coefficients were approximately 5% lower than the strip theory results. Simplifying assumptions made in the strip theory account for the differences seen.

  13. Particle-laden weakly swirling free jets: Measurements and predictions. Ph.D. Thesis - Pennsylvania State Univ.

    NASA Technical Reports Server (NTRS)

    Bulzan, Daniel L.

    1988-01-01

    A theoretical and experimental investigation of particle-laden, weakly swirling, turbulent free jets was conducted. Glass particles, having a Sauter mean diameter of 39 microns, with a standard deviation of 15 microns, were used. A single loading ratio (the mass flow rate of particles per unit mass flow rate of air) of 0.2 was used in the experiments. Measurements are reported for three swirl numbers, ranging from 0 to 0.33. The measurements included mean and fluctuating velocities of both phases, and particle mass flux distributions. Measurements were also completed for single-phase non-swirling and swirling jets, as baselines. Measurements were compared with predictions from three types of multiphase flow analysis, as follows: (1) locally homogeneous flow (LHF) where slip between the phases was neglected; (2) deterministic separated flow (DSF), where slip was considered but effects of turbulence/particle interactions were neglected; and (3) stochastic separated flow (SSF), where effects of both interphase slip and turbulence/particle interactions were considered using random sampling for turbulence properties in conjunction with random-walk computations for particle motion. Single-phase weakly swirling jets were considered first. Predictions using a standard k-epsilon turbulence model, as well as two versions modified to account for effects of streamline curvature, were compared with measurements. Predictions using a streamline curvature modification based on the flux Richardson number gave better agreement with measurements for the single-phase swirling jets than the standard k-epsilon model. For the particle-laden jets, the LHF and DSF models did not provide very satisfactory predictions. The LHF model generally overestimated the rate of decay of particle mean axial and angular velocities with streamwise distance, and predicted particle mass fluxes also showed poor agreement with measurements, due to the assumption of no-slip between phases. The DSF model also performed quite poorly for predictions of particle mass flux because turbulent dispersion of the particles was neglected. The SSF model, which accounts for both particle inertia and turbulent dispersion of the particles, yielded reasonably good predictions throughout the flow field for the particle-laden jets.

  14. The effect of grain boundaries on the resistivity of polycrystalline silicon. Ph.D. Thesis - Va. Univ.

    NASA Technical Reports Server (NTRS)

    Fripp, A. L., Jr.

    1974-01-01

    The electrical resistivity of polycrystalline silicon films was investigated. The films were grown by the chemical vapor decomposition of silane on oxidized silicon wafers. The resistivity was found to be independent of dopant atom concentration in the lightly doped regions but was a strong function of dopant levels in the more heavily doped regions. A model, based on high dopant atom segregation in the grain boundaries, is proposed to explain the results.

  15. Thermomechanical and Thermochemical Behavior of a Hafnium-20 Percent Tantalum Alloy. Ph.D. Thesis - North Carolina State Univ., Raleigh

    NASA Technical Reports Server (NTRS)

    Howell, J. P.

    1971-01-01

    An investigation was conducted to determine the thermomechanical and thermochemical behavior of a high temperature, oxidation resistant, hafnium-20 percent tantalum alloy. The elastic and shear moduli of this alloy were determined in air up to 1000 C and in vacuum up to 2000 C using a mechanical resonance technique. The internal friction of the alloy was measured up to temperatures greater than 1400 C. Room temperature stress-strain behavior of the oxidized and unoxidized alloy was established. The effect of annealing on the elastic and shear moduli of the extruded rod material was investigated. The martensitic-type phase transformation occurring in the alloy was studied using hot stage metallography and electron microscopy. Static oxidation tests were conducted on the alloy at temperatures from 1000 C to 1700 C with weight gain measurements made as a function of time and temperatures. Surface morphology studies were conducted on the oxide coatings formed at the different temperatures using scanning electron microscopy and X-ray diffraction techniques.

  16. Thermomechanical deformation testing and modeling in the presence of metallurgical instabilities. M.S. Thesis - Akron Univ. Final Report

    NASA Technical Reports Server (NTRS)

    Castelli, Michael G.

    1990-01-01

    A number of viscoplastic constitutive models were developed to describe deformation behavior under complex combinations of thermal and mechanical loading. Questions remain, however, regarding the validity of procedures used to characterize these models for specific structural alloys. One area of concern is that the majority of experimental data available for this purpose are determined under isothermal conditions. This experimental study is aimed at determining whether viscoplastic constitutive theories characterized using an isothermal data base can adequately model material response under the complex thermomechanical loading conditions typical of power generation service. The approach adopted was to conduct a series of carefully controlled thermomechanical experiments on a nickel-based superalloy, Hastelloy Alloy X. Previous investigations had shown that this material experiences metallurgical instabilities leading to complex hardening behavior, termed dynamic strain aging. Investigating this phenomenon under full thermomechanical conditions leads to a number of challenging experimental difficulties which up to the present work were unresolved. To correct this situation, a number of advances were made in thermomechanical testing techniques. Advanced methods for dynamic temperature gradient control, phasing control and thermal strain compensation were developed and incorporated into real time test control software. These advances allowed the thermomechanical data to be analyzed with minimal experimental uncertainty. The thermomechanical results were evaluated on both a phenomenological and microstructural basis. Phenomenological results revealed that the thermomechanical hardening trends were not bounded by those displayed under isothermal conditions. For the case of Hastelloy Alloy X (and similar dynamic strain aging materials), this strongly suggests that some form of thermomechanical testing is necessary when characterizing a thermoviscoplastic deformation model. Transmission electron microscopy was used to study the microstructural physics, and analyze the unique phenomenological behavior.

  17. Study of potential aerodynamic benefits from spanwise blowing at wingtip. Ph.D. Thesis - George Washington Univ., 1992

    NASA Technical Reports Server (NTRS)

    Mineck, Raymond E.

    1995-01-01

    Comprehensive experimental and analytical studies have been conducted to assess the potential aerodynamic benefits from spanwise blowing at the tip of a moderate-aspect-ratio swept wing. Previous studies on low-aspect-ratio wings indicated that blowing from the wingtip can diffuse the tip vortex and displace it outward. The diffused and displaced vortex will induce a smaller downwash at the wing, and consequently the wing will have increased lift and decreased induced drag at a given angle of attack. Results from the present investigation indicated that blowing from jets with a short chord had little effect on lift or drag, but blowing from jets with a longer chord increased lift near the tip and reduced drag at low Mach numbers. A Navier-Stokes solver with modified boundary conditions at the tip was used to extrapolate the results to a Mach number of 0.72. Calculations indicated that lift and drag increase with increasing jet momentum coefficient. Because the momentum of the jet is typically greater than the reduction in the wing drag and the increase in the wing lift due to spanwise blowing is small, spanwise blowing at the wingtip does not appear to be a practical means of improving the aerodynamic efficiency of moderate-aspectratio swept wings at high subsonic Mach numbers.

  18. Solution of an eigenvalue problem for the Laplace operator on a spherical surface. M.S. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Walden, H.

    1974-01-01

    Methods for obtaining approximate solutions for the fundamental eigenvalue of the Laplace-Beltrami operator (also referred to as the membrane eigenvalue problem for the vibration equation) on the unit spherical surface are developed. Two specific types of spherical surface domains are considered: (1) the interior of a spherical triangle, i.e., the region bounded by arcs of three great circles, and (2) the exterior of a great circle arc extending for less than pi radians on the sphere (a spherical surface with a slit). In both cases, zero boundary conditions are imposed. In order to solve the resulting second-order elliptic partial differential equations in two independent variables, a finite difference approximation is derived. The symmetric (generally five-point) finite difference equations that develop are written in matrix form and then solved by the iterative method of point successive overrelaxation. Upon convergence of this iterative method, the fundamental eigenvalue is approximated by iteration utilizing the power method as applied to the finite Rayleigh quotient.

  19. Small-Scale Spatial Fluctuations in the Soft X-Ray Background. Degree awarded by Maryland Univ., 2000

    NASA Technical Reports Server (NTRS)

    Kuntz, K. D.; White, Nicolas E. (Technical Monitor)

    2001-01-01

    In order to isolate the diffuse extragalactic component of the soft X-ray background, we have used a combination of ROSAT All-Sky Survey and IRAS 100 micron data to separate the soft X-ray background into five components. We find a Local Hot Bubble similar to that described by Snowden et al (1998). We make a first calculation of the contribution by unresolved Galactic stars to the diffuse background. We constrain the normalization of the Extragalactic Power Law (the contribution of the unresolved extragalactic point sources such as AGN, QSO'S, and normal galaxies) to 9.5 +/- 0.9 keV/(sq cm s sr keV), assuming a power-law index of 1.46. We show that the remaining emission, which is some combination of Galactic halo emission and the putative diffuse extragalactic emission, must be composed of at least two components which we have characterized by thermal spectra. The softer component has log T - 6.08 and a patchy distribution; thus it is most probably part of the Galactic halo. The harder component has log T - 6.46 and is nearly isotropic; some portion may be due to the Galactic halo and some portion may be due to the diffuse extragalactic emission. The maximum upper limit to the strength of the emission by the diffuse extragalactic component is the total of the hard component, approx. 7.4 +/- 1.0 keV/(sq cm s sr keV) in the 3/4 keV band. We have made the first direct measure of the fluctuations due to the diffuse extragalactic emission in the 3/4 keV band. Physical arguments suggest that small angular scale (approx. 10') fluctuations in the Local Hot Bubble or the Galactic halo will have very short dissipation times (about 10(exp 5) years). Therefore, the fluctuation spectrum of the soft X-ray background should measure the distribution of the diffuse extragalactic emission. Using mosaics of deep, overlapping PSPC pointings, we find an autocorrelation function value of approx. 0.0025 for 10' < theta < 20', and a value consistent with zero on larger scales. Measurement of the fluctuations with a delta I/I method produces consistent results.

  20. [Research in two-dimensional critical phenomena and conformal field theory]. [Rutgers, The State Univ. , New Brunswick, New Jersey

    SciTech Connect

    Not Available

    1990-01-01

    A very theoretical description is given of research in two- dimensional critical phenomena and conformal field theory. Major progress is reported in the field of fluctuating two-dimensional surfaces. A discretized representation of fluctuating geometry is used where surfaces are represented by triangulations; continuum surfaces are recovered by taking the size of the triangles to zero. One of the central goals of the theory of critical phenomena is to find all possible universality classes of n-dimensional critical phenomena; this goal has been translated into the problem of clasifying all possible scale-invariant euclidean quantum field theories. (RWR)

  1. Mathematical crew motion disturbance models for spacecraft control system design. M.S. Thesis - George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Conway, B. A.

    1974-01-01

    Several techniques for modeling the disturbances to a spacecraft's attitude caused by moving crew members are presented. These disturbances can be the largest moments acting on a manned spacecraft, and knowledge of their effect is important in the sizing, design, and analysis/simulation of spacecraft attitude control systems. The modeling techniques are identified as two principal types: deterministic and stochastic. Three techniques of each type are presented. The deterministic models include point-mass motion derivatives and a discussion on dynamic models of moving crew members. The stochastic techniques are highlighted by a Fourier transform method and the representation of long-term crew disturbance activities as outputs from appropriately designed filters. A z-transform technique is developed to obtain a difference-equation form of stochastic models for use on digital computers. An appendix derives spacecraft equations of motion which can be used with many of the models discussed.

  2. [List and drag forces on droplets and particles in wall-bounded shear flows]. [Progress report, Clarkson Univ

    SciTech Connect

    McLaughlin, J.B.

    1992-01-01

    This project has two goals, to calculate the lift force on a spherical droplet or particle that translates through a shear flow, and to measure the inertial migration velocity that is caused by the lift force. The focus of the study is on a range of Reynolds numbers that has been shown to be of importance in the inertial deposition of aerosols from turbulent shear flows. Aspects of current technical progress summarized are the asymptotic analysis, computer simulations, and experimental measurements. Future plans and resulting publications are given.

  3. Optical computing and neural networks; Proceedings of the Meeting, National Chiao Tung Univ., Hsinchu, Taiwan, Dec. 16, 17, 1992

    NASA Technical Reports Server (NTRS)

    Hsu, Ken-Yuh (Editor); Liu, Hua-Kuang (Editor)

    1992-01-01

    The present conference discusses optical neural networks, photorefractive nonlinear optics, optical pattern recognition, digital and analog processors, and holography and its applications. Attention is given to bifurcating optical information processing, neural structures in digital halftoning, an exemplar-based optical neural net classifier for color pattern recognition, volume storage in photorefractive disks, and microlaser-based compact optical neuroprocessors. Also treated are the optical implementation of a feature-enhanced optical interpattern-associative neural network model and its optical implementation, an optical pattern binary dual-rail logic gate module, a theoretical analysis for holographic associative memories, joint transform correlators, image addition and subtraction via the Talbot effect, and optical wavelet-matched filters. (No individual items are abstracted in this volume)

  4. Correlation of finite element free vibration predictions using random vibration test data. M.S. Thesis - Cleveland State Univ.

    NASA Technical Reports Server (NTRS)

    Chambers, Jeffrey A.

    1994-01-01

    Finite element analysis is regularly used during the engineering cycle of mechanical systems to predict the response to static, thermal, and dynamic loads. The finite element model (FEM) used to represent the system is often correlated with physical test results to determine the validity of analytical results provided. Results from dynamic testing provide one means for performing this correlation. One of the most common methods of measuring accuracy is by classical modal testing, whereby vibratory mode shapes are compared to mode shapes provided by finite element analysis. The degree of correlation between the test and analytical mode shapes can be shown mathematically using the cross orthogonality check. A great deal of time and effort can be exhausted in generating the set of test acquired mode shapes needed for the cross orthogonality check. In most situations response data from vibration tests are digitally processed to generate the mode shapes from a combination of modal parameters, forcing functions, and recorded response data. An alternate method is proposed in which the same correlation of analytical and test acquired mode shapes can be achieved without conducting the modal survey. Instead a procedure is detailed in which a minimum of test information, specifically the acceleration response data from a random vibration test, is used to generate a set of equivalent local accelerations to be applied to the reduced analytical model at discrete points corresponding to the test measurement locations. The static solution of the analytical model then produces a set of deformations that once normalized can be used to represent the test acquired mode shapes in the cross orthogonality relation. The method proposed has been shown to provide accurate results for both a simple analytical model as well as a complex space flight structure.

  5. Computational aspects of sensitivity calculations in linear transient structural analysis. Ph.D. Thesis - Virginia Polytechnic Inst. and State Univ.

    NASA Technical Reports Server (NTRS)

    Greene, William H.

    1990-01-01

    A study was performed focusing on the calculation of sensitivities of displacements, velocities, accelerations, and stresses in linear, structural, transient response problems. One significant goal of the study was to develop and evaluate sensitivity calculation techniques suitable for large-order finite element analyses. Accordingly, approximation vectors such as vibration mode shapes are used to reduce the dimensionality of the finite element model. Much of the research focused on the accuracy of both response quantities and sensitivities as a function of number of vectors used. Two types of sensitivity calculation techniques were developed and evaluated. The first type of technique is an overall finite difference method where the analysis is repeated for perturbed designs. The second type of technique is termed semi-analytical because it involves direct, analytical differentiation of the equations of motion with finite difference approximation of the coefficient matrices. To be computationally practical in large-order problems, the overall finite difference methods must use the approximation vectors from the original design in the analyses of the perturbed models. In several cases this fixed mode approach resulted in very poor approximations of the stress sensitivities. Almost all of the original modes were required for an accurate sensitivity and for small numbers of modes, the accuracy was extremely poor. To overcome this poor accuracy, two semi-analytical techniques were developed. The first technique accounts for the change in eigenvectors through approximate eigenvector derivatives. The second technique applies the mode acceleration method of transient analysis to the sensitivity calculations. Both result in accurate values of the stress sensitivities with a small number of modes and much lower computational costs than if the vibration modes were recalculated and then used in an overall finite difference method.

  6. Procedures for Computing Transonic Flows for Control of Adaptive Wind Tunnels. Ph.D. Thesis - Technische Univ., Berlin, Mar. 1986

    NASA Technical Reports Server (NTRS)

    Rebstock, Rainer

    1987-01-01

    Numerical methods are developed for control of three dimensional adaptive test sections. The physical properties of the design problem occurring in the external field computation are analyzed, and a design procedure suited for solution of the problem is worked out. To do this, the desired wall shape is determined by stepwise modification of an initial contour. The necessary changes in geometry are determined with the aid of a panel procedure, or, with incident flow near the sonic range, with a transonic small perturbation (TSP) procedure. The designed wall shape, together with the wall deflections set during the tunnel run, are the input to a newly derived one-step formula which immediately yields the adapted wall contour. This is particularly important since the classical iterative adaptation scheme is shown to converge poorly for 3D flows. Experimental results obtained in the adaptive test section with eight flexible walls are presented to demonstrate the potential of the procedure. Finally, a method is described to minimize wall interference in 3D flows by adapting only the top and bottom wind tunnel walls.

  7. On the Age of Cosmic Rays as Derived from the Abundance of Be-10. Ph.D. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Hagen, F. A.

    1976-01-01

    The isotopic composition of cosmic ray Be, B, C, and N was studied using a new range versus total light technique. Special emphasis was placed on the Be isotopes and in particular, on the radioactive isotope Be-10 due to its mean lifetime against decay. The experiment consisted of a thin trigger scintillator, an acrylic plastic Cerenkov detector and a spark chamber, followed by a totally active stack of 14 scintillation detectors. This stack of scintillators made possible the measurement of range, and also permitted the removal of interacting events by continuously monitoring their identities along their trajectories. The experiment was carried by balloon to atmospheric depths ranging from 3.5 to 5.0 g sq cm residual atmosphere for a total exposure time of 23 hr. Results indicate the survival of ( 55 + or -21) % of the Be-10 in the arriving cosmic rays; the data were interpreted using the leaky box model of cosmic ray propagation.

  8. Stress concentration factors for circular, reinforced penetrations in pressurized cylindrical shells. Ph.D. Thesis - Virginia Univ.

    NASA Technical Reports Server (NTRS)

    Ramsey, J. W., Jr.

    1975-01-01

    The effect on stresses in a cylindrical shell with a circular penetration subject to internal pressure was investigated in thin, shallow linearly, elastic cylindrical shells. Results provide numerical predictions of peak stress concentration factors around nonreinforced and reinforced penetrations in pressurized cylindrical shells. Analytical results were correlated with published formulas, as well as theoretical and experimental results. An accuracy study was made of the finite element program for each of the configurations considered important in pressure vessel technology. A formula is developed to predict the peak stress concentration factor for analysis and/or design in conjunction with the ASME Boiler and Pressure Vessel Code.

  9. Taxonomic classification of soils using digital information from LANDSAT data. Huayllamarca and eucaliptus areas. M.S. Thesis - Bolivia Univ.

    NASA Technical Reports Server (NTRS)

    Quiroga, S. Q.

    1977-01-01

    The applicability of LANDSAT digital information to soil mapping is described. A compilation of all cartographic information and bibliography of the study area is made. LANDSAT MSS images on a scale of 1:250,000 are interpreted and a physiographic map with legend is prepared. The study area is inspected and a selection of the sample areas is made. A digital map of the different soil units is produced and the computer mapping units are checked against the soil units encountered in the field. The soil boundaries obtained by automatic mapping were not substantially changed by field work. The accuracy of the automatic mapping is rather high.

  10. Static stability of a three-dimensional space truss. M.S. Thesis - Case Western Reserve Univ., 1994

    NASA Technical Reports Server (NTRS)

    Shaker, John F.

    1995-01-01

    In order to deploy large flexible space structures it is necessary to develop support systems that are strong and lightweight. The most recent example of this aerospace design need is vividly evident in the space station solar array assembly. In order to accommodate both weight limitations and strength performance criteria, ABLE Engineering has developed the Folding Articulating Square Truss (FASTMast) support structure. The FASTMast is a space truss/mechanism hybrid that can provide system support while adhering to stringent packaging demands. However, due to its slender nature and anticipated loading, stability characterization is a critical part of the design process. Furthermore, the dire consequences surely to result from a catastrophic instability quickly provide the motivation for careful examination of this problem. The fundamental components of the space station solar array system are the (1) solar array blanket system, (2) FASTMast support structure, and (3) mast canister assembly. The FASTMast once fully deployed from the canister will provide support to the solar array blankets. A unique feature of this structure is that the system responds linearly within a certain range of operating loads and nonlinearly when that range is exceeded. The source of nonlinear behavior in this case is due to a changing stiffness state resulting from an inability of diagonal members to resist applied loads. The principal objective of this study was to establish the failure modes involving instability of the FASTMast structure. Also of great interest during this effort was to establish a reliable analytical approach capable of effectively predicting critical values at which the mast becomes unstable. Due to the dual nature of structural response inherent to this problem, both linear and nonlinear analyses are required to characterize the mast in terms of stability. The approach employed herein is one that can be considered systematic in nature. The analysis begins with one and two-dimensional failure models of the system and its important components. From knowledge gained through preliminary analyses a foundation is developed for three-dimensional analyses of the FASTMast structure. The three-dimensional finite element (FE) analysis presented here involves a FASTMast system one-tenth the size of the actual flight unit. Although this study does not yield failure analysis results that apply directly to the flight article, it does establish a method by which the full-scale mast can be evaluated.

  11. A modal aeroelastic analysis scheme for turbomachinery blading. M.S. Thesis - Case Western Reserve Univ. Final Report

    NASA Technical Reports Server (NTRS)

    Smith, Todd E.

    1991-01-01

    An aeroelastic analysis is developed which has general application to all types of axial-flow turbomachinery blades. The approach is based on linear modal analysis, where the blade's dynamic response is represented as a linear combination of contributions from each of its in-vacuum free vibrational modes. A compressible linearized unsteady potential theory is used to model the flow over the oscillating blades. The two-dimensional unsteady flow is evaluated along several stacked axisymmetric strips along the span of the airfoil. The unsteady pressures at the blade surface are integrated to result in the generalized force acting on the blade due to simple harmonic motions. The unsteady aerodynamic forces are coupled to the blade normal modes in the frequency domain using modal analysis. An iterative eigenvalue problem is solved to determine the stability of the blade when the unsteady aerodynamic forces are included in the analysis. The approach is demonstrated by applying it to a high-energy subsonic turbine blade from a rocket engine turbopump power turbine. The results indicate that this turbine could undergo flutter in an edgewise mode of vibration.

  12. Numerical solution of the incompressible Navier-Stokes equations. Ph.D. Thesis - Stanford Univ., Mar. 1989

    NASA Technical Reports Server (NTRS)

    Rogers, Stuart E.

    1990-01-01

    The current work is initiated in an effort to obtain an efficient, accurate, and robust algorithm for the numerical solution of the incompressible Navier-Stokes equations in two- and three-dimensional generalized curvilinear coordinates for both steady-state and time-dependent flow problems. This is accomplished with the use of the method of artificial compressibility and a high-order flux-difference splitting technique for the differencing of the convective terms. Time accuracy is obtained in the numerical solutions by subiterating the equations in psuedo-time for each physical time step. The system of equations is solved with a line-relaxation scheme which allows the use of very large pseudo-time steps leading to fast convergence for steady-state problems as well as for the subiterations of time-dependent problems. Numerous laminar test flow problems are computed and presented with a comparison against analytically known solutions or experimental results. These include the flow in a driven cavity, the flow over a backward-facing step, the steady and unsteady flow over a circular cylinder, flow over an oscillating plate, flow through a one-dimensional inviscid channel with oscillating back pressure, the steady-state flow through a square duct with a 90 degree bend, and the flow through an artificial heart configuration with moving boundaries. An adequate comparison with the analytical or experimental results is obtained in all cases. Numerical comparisons of the upwind differencing with central differencing plus artificial dissipation indicates that the upwind differencing provides a much more robust algorithm, which requires significantly less computing time. The time-dependent problems require on the order of 10 to 20 subiterations, indicating that the elliptical nature of the problem does require a substantial amount of computing effort.

  13. Triangulation Error Analysis for the Barium Ion Cloud Experiment. M.S. Thesis - North Carolina State Univ.

    NASA Technical Reports Server (NTRS)

    Long, S. A. T.

    1973-01-01

    The triangulation method developed specifically for the Barium Ion Cloud Project is discussed. Expression for the four displacement errors, the three slope errors, and the curvature error in the triangulation solution due to a probable error in the lines-of-sight from the observation stations to points on the cloud are derived. The triangulation method is then used to determine the effect of the following on these different errors in the solution: the number and location of the stations, the observation duration, east-west cloud drift, the number of input data points, and the addition of extra cameras to one of the stations. The pointing displacement errors, and the pointing slope errors are compared. The displacement errors in the solution due to a probable error in the position of a moving station plus the weighting factors for the data from the moving station are also determined.

  14. Assessment of Potential Aerodynamic Benefits from Spanwise Blowing at the Wing Tip. Ph.D. Thesis - George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Mineck, Raymond Edward

    1992-01-01

    A comprehensive set of experimental and analytical investigations have been conducted to assess the potential aerodynamic benefits from spanwise blowing at the tip of a moderate aspect ratio, swept wing. An analytical model has been developed to simulate a jet exhausting from the wing tip. An experimental study of a subsonic jet exhausting from the wing tip was conducted to investigate the effect of spanwise blowing from the tip on the aerodynamic characteristics of a moderate aspect ratio, swept wing. Wing force and moment data and surface pressure data were measured at Mach numbers up to 0.72. Results indicate that small amounts of blowing from small jets increase the lift curve slope a small amount, but have no effect on drag. Larger amounts of blowing from longer jets blowing increases lift near the tip and reduce drag at low Mach numbers. These benefits decrease with increasing Mach number, and vanish at Mach 0.5. A Navier-Stokes solver with modified boundary conditions at the tip was used to extrapolate the results to a Mach number of 0.72. With current technology and conventional wing shapes, spanwise blowing at the wing tip does not appear to be a practical means of reducing drag of moderate aspect ratio wings at high subsonic Mach numbers.

  15. Wallops Station and the Creation of an American Space Program. Master's Degree awarded by Univ. of Maryland-Baltimore County

    NASA Technical Reports Server (NTRS)

    Wallace, Harold D., Jr.

    1997-01-01

    As part of the NASA history series a detailed history of Wallops Space Flight Facility from 1957 to 1966 is given. Discussions of Sputnik, NASA, Piloted Space Flight, Space Science Research, and comments on the changes the facility went through during the period are presented. Several appendices are attached as well covering R&D Launches, the NACA Era, organizational charts, Wallops' complement, and selected international cooperative programs.

  16. Charge composition of high energy heavy primary cosmic ray nuclei. Ph.D. Thesis - Catholic Univ. of Am.

    NASA Technical Reports Server (NTRS)

    Price, R. D.

    1974-01-01

    A detailed study of the charge composition of primary cosmic radiation for about 5000 charged nuclei from neon to iron with energies greater than 1.16 GeV/nucleon is presented. Values are obtained after corrections were made for detector dependences, atmospheric attenuation, and solar modulation. New values of 38.5, 32.4, 23.7, and 16.8 g/sq cm for the attenuation mean free paths in air for the same charge groups are presented.

  17. UNIV 83. A Student's Work. Proceedings of the International University Congress (15th, Rome, Italy, March 26-April 4, 1983).

    ERIC Educational Resources Information Center

    Cooperation in Education: International Quarterly of the Institute for University Cooperation, 1983

    1983-01-01

    In this proceedings, attention is focused on career preparation and the relationship between general and specialized studies, as well as the link between theoretical knowledge and practical experience. The preparatory study for the congress was conducted in about 300 universities, primarily in Europe and America. Nearly 15,000 interviews were…

  18. Continuation of support for the intercampus Institute for research at particle accelerators. [Univ. of California, San Diego

    SciTech Connect

    Vernon, W.

    1992-01-01

    The dominant Institute activity was preparation of hardware and software for the LSND experiment at Los Alamos, which concerns a search for neutrino oscillations in three different ways and a measurement of the contribution ([Delta]s) of strange quarks to the spin of the proton. Much of the effort dealt with particle detectors, the liquid scintillation detector for LSND and the detectors for the B Factory at SLAC.

  19. Experimental investigation of turbulent flow through a circular-to-rectangular transition duct. Ph.D. Thesis - Washington Univ.

    NASA Technical Reports Server (NTRS)

    Davis, David O.

    1991-01-01

    Steady, incompressible, turbulent, swirl-free flow through a circular-to-rectangular transition duck was studied experimentally. The cross-sectional area remains the same at the exit as at the inlet, but varies through the transition section to a maximum value approximately 15 percent above the inlet value. The cross-sectional geometry everywhere along the duct is defined by the equation of a superellipse. Mean and turbulence data were accumulated utilizing pressure and hot-wire instrumentation at five stations along the test section. Data are presented for operating bulk Reynolds numbers of 88,000 and 390,000. Measured quantities include total and static pressure, the three components of the mean velocity vector, and the six components of the Reynolds stress tensor. In addition to the transition duct measurements, a hot-wire technique which relies on the sequential use of single rotatable normal and slant-wire probes was proposed. The technique is applicable for measurement of the total mean velocity vector and the complete Reynolds stress tensor when the primary flow is arbitrarily skewed relative to a plane which lies normal to the probe axis of rotation.

  20. An analytical and experimental study to investigate flutter suppression via piezoelectric actuation. M.S. Thesis - George Washington Univ., 1991

    NASA Technical Reports Server (NTRS)

    Heeg, Jennifer

    1991-01-01

    The objective was to analytically and experimentally study the capabilities of adaptive material plate actuators for suppressing flutter. The validity of analytical modeling techniques for piezoelectric materials was also investigated. Piezoelectrics are materials which are characterized by their ability to produce voltage when subjected to a mechanical strain. The converse piezoelectric effect can be utilized to actuate a structure by applying a voltage. For this investigation, a two degree of freedom wind tunnel model was designed, analyzed, and tested. The model consisted of a rigid airfoil and a flexible mount system which permitted a translational and a rotational degree of freedom. It was designed such that flutter was encounted within the testing envelope of the wind tunnel. Actuators, made of piezoelectric material were affixed to leaf springs of the mount system. Each degree of freedom was controlled by a separate leaf spring. Command signals, applied to the piezoelectric actuators, exerted control over the damping and stiffness properties. A mathematical aeroservoelastic model was constructed using finite element methods, laminated plate theory, and aeroelastic analysis tools. Plant characteristics were determined from this model and verified by open loop experimental tests. A flutter suppression control law was designed and implemented on a digital control computer. Closed loop flutter testing was conducted. The experimental results represent the first time that adaptive materials have been used to actively suppress flutter. It demonstrates that small, carefully placed actuating plates can be used effectively to control aeroelastic response.