Science.gov

Sample records for toivo univer ao

  1. Cosmicflows Constrained Local UniversE Simulations

    NASA Astrophysics Data System (ADS)

    Sorce, Jenny G.; Gottlöber, Stefan; Yepes, Gustavo; Hoffman, Yehuda; Courtois, Helene M.; Steinmetz, Matthias; Tully, R. Brent; Pomarède, Daniel; Carlesi, Edoardo

    2016-01-01

    This paper combines observational data sets and cosmological simulations to generate realistic numerical replicas of the nearby Universe. The latter are excellent laboratories for studies of the non-linear process of structure formation in our neighbourhood. With measurements of radial peculiar velocities in the local Universe (cosmicflows-2) and a newly developed technique, we produce Constrained Local UniversE Simulations (CLUES). To assess the quality of these constrained simulations, we compare them with random simulations as well as with local observations. The cosmic variance, defined as the mean one-sigma scatter of cell-to-cell comparison between two fields, is significantly smaller for the constrained simulations than for the random simulations. Within the inner part of the box where most of the constraints are, the scatter is smaller by a factor of 2 to 3 on a 5 h-1 Mpc scale with respect to that found for random simulations. This one-sigma scatter obtained when comparing the simulated and the observation-reconstructed velocity fields is only 104 ± 4 km s-1, i.e. the linear theory threshold. These two results demonstrate that these simulations are in agreement with each other and with the observations of our neighbourhood. For the first time, simulations constrained with observational radial peculiar velocities resemble the local Universe up to a distance of 150 h-1 Mpc on a scale of a few tens of megaparsecs. When focusing on the inner part of the box, the resemblance with our cosmic neighbourhood extends to a few megaparsecs (<5 h-1 Mpc). The simulations provide a proper large-scale environment for studies of the formation of nearby objects.

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

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

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

    83. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, date unknown. DRY CREEK GATES, TWIN FALLS COUNTY, SOUTH OF MURTAUGH, IDAHO; GATES FROM THE LOWER SIDE. - 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. 87. Photocopy of Photograph (original located in Univ. of Denver ...

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

    87. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, date unknown. ROCK CREEK SIPHON, LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; UPPER END OF THE SIPHON. - 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. 82. Photocopy of Photograph (original located in Univ. of Denver ...

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

    82. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, date unknown. DRY CREEK HEADGATES, TWIN FALLS COUNTY, SOUTH OF MURTAUGH, IDAHO; CHECK GATES ACROSS THE MAIN CANAL BELOW DRY CREEK. - 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. 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

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

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

    86. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, date unknown. ROCK CREEK SIPHON, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; MEN WORKING ON THE EAST END OF THE SIPHON. - 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. 84. Photocopy of Photograph (original located in Univ. of Denver ...

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

    84. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, date unknown. ROCK CREEK SIPHON, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; WEST VIEW OF SIPHON PIPE. - 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. 85. Photocopy of Photograph (original located in Univ. of Denver ...

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

    85. Photocopy of Photograph (original located in Univ. of Denver collection). C.R. Savage, Photographer, date unknown. ROCK CREEK SIPHON, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; EAST VIEW OF SIPHON PIPE. - 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. 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

  18. 56. Photocopy of Photograph (original located in Univ. of Denver ...

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

    56. Photocopy of Photograph (original located in Univ. of Denver collection) C.R. Savage, Photographer, March, 1905. MILNER DAM SPILLWAY AND GATES; BATTERY OF REGULATING GATES FROM DOWNSTREAM SIDE. - 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

  19. Multirate LQG AO control

    NASA Astrophysics Data System (ADS)

    Raynaud, H. F.; Kulcsár, C.; Correia da Silva, C.; Conan, J. M.

    2008-07-01

    All thing being equal, increasing the sampling rate of a computer-controlled feedback loop extends its effective bandwidth, and thus the achievable performance in terms of disturbance rejection. This applies to AO systems, where deformable mirror's (DM) control voltages are computed from wavefront sensor's (WFS) measurements. However, faster sampling, i.e. shorter exposure time for the WFS's CCD, results (especially for low-flux astronomical applications) in higher measurement noise, thereby degrading overall performance. A way to circumvent this limitation is to increase only the DM's control rate. However, standard integral AO control is inherently ill-suited for such multirate mode, because integrators require an uninterrupted measurement stream to maintain closed-loop stability. On the other hand, Linear Quadratic Gaussian (LQG) AO control, where DM controls are computed from explicit predictions of future values of the turbulent phase provided by a Kalman filter, can be easily adapted to multirate configurations where the WFS sampling period is a multiple of the DM's one, provided that a stochastic model of the turbulent phase at the fast (DM) rate is available. The Kalman filter, between two successive measurements, operates in (observer) open-loop mode, with predictions updated by extrapolating current trends in the turbulent phase's trajectory. Thus, while simple vector-valued AR(1) turbulence models are sufficient for single-rate LQG AO loops, more complex stochastic models are likely to be needed to achieve good performance in multirate configurations.

  20. 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

  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. 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.

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

    SciTech Connect

    Curtis, Peter; Gough, Christopher

    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.

  4. MEMS AO for Planet Finding

    NASA Technical Reports Server (NTRS)

    Rao, Shanti; Wallace, J. Kent; Shao, Mike; Schmidtlin, Edouard; Levine, B. Martin; Samuele, Rocco; Lane, Benjamin; Chakrabarti, Supriya; Cook, Timothy; Hicks, Brian; Jung, Paul

    2008-01-01

    This slide presentation reviews a method for planet finding using microelectromechanical systems (MEMS) Adaptive Optics (AO). The use of a deformable mirror (DM) is described as a part of the instrument that was designed with a nulling interferometer. The strategy that is used is described in detail.

  5. 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.

  6. FALCON: multi-object AO

    NASA Astrophysics Data System (ADS)

    Gendron, Eric; Assémat, François; Hammer, François; Jagourel, Pascal; Chemla, Fanny; Laporte, Philippe; Puech, Mathieu; Marteaud, Michel; Zamkotsian, Frédéric; Liotard, Arnaud; Conan, Jean-Marc; Fusco, Thierry; Hubin, Norbert

    2005-12-01

    FALCON is a wide-field, multi-object integral field spectrograph equipped with adaptive optics. It is dedicated to the study of the formation process of primordial galaxies. The AO system uses natural guide stars, and the high sky coverage required for these studies is obtained using tomographic techniques for the wavefront analysis. The structure of the OA system is very new, and particularly suited for a future implementation on extremely large telescopes. To cite this article: E. Gendron et al., C. R. Physique 6 (2005).

  7. Effect of sowing dates and vernalization on Beta vulgaris L. cv. Univers C-leaf structure.

    PubMed

    Sakr, Mohammed M; Almaghrabi, Omar A

    2011-07-01

    This research was conducted to study the effect of three different sowing dates (15th October, 15th November and 15th December) and two vernalization treatments (5C and -20C) on leaf structure of Beta vulgaris L. cv. Univers. The obtained data are summarized as follows: The maximum values of the most studied parameters; lower epidermis+spongy tissue thickness, midrib, mesophyll tissue, vascular bundle, collenchymatous tissue and number of xylem vessels per arm were found as a result of 15th October sowing date treatment compared with the two other sowing dates. Furthermore, effect of the cooling treatments varied according to the recorded character, sowing date and cooling degree. Most of the vernalization treatments at early sowing dates increased the mesophyll tissue, midrib, number of vascular bundles per transverse section, vascular bundle thickness and number of xylem arms per transverse section. The two studied cooling treatments at 15th October sowing date increased both stomatal index and average number of stomata: average number of epidermis cells compared with the control. Furthermore, 15th October under -20C treatment led to small epidermal cells and stomata formation, straight epidermal cell walls and closed stomata in comparison to the control. PMID:23961134

  8. 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.

  9. Experiments on the nuclear interactions of pions and electrons. [Dept. of Physics, Univ. of Virginia

    SciTech Connect

    Minehart, R.C.; Ziock, K.O.H.

    1992-08-01

    The analysis of the deuterium content in the CD target used in an experiment to study the [pi] + d [yields] 2p reaction at incident pion energies from 4 to 20 MeV was completed. The final paper describing this experiment will be submitted for publication this summer. Analysis of LAMPF Exp. on pion absorption in [sup 4]He is continuing. In 1991, we collaborated with D. Pocanic from the Univ. of Virginia on a measurement at LAMPF of the [pi][sup 0] production in [pi] + p interactions. This run proved the validity of the method and additional data were obtained in a second run during the summer of 1992, using a new target. Current collaborations at LAMPF include the search for the decay [mu][sup +] [yields] e[sup +] + [gamma](MEGA) and a measurement of the Michel [rho] parameter in the decay [mu] [yields] e + v + v. A U.Va.--PSI collaboration is measuring pion beta decay to an accuracy of less than 1%, using a large acceptance CsI detector to measure the [pi][sup 0] following decay of stopped [pi][sup +] mesons. Most of the U.Va. effort is devoted to the CEBAF Large Acceptance Spectrometer (CLAS) program to the construction of the CLAS forward calorimeter. An apparatus to measure the properties of the scintillators with light from a N[sub 2] laser was built in the spring of 1992. The electronic circuitry for the energy signal from the EGN detector and the circuitry needed to route the signals from the all the photomultipliers to the TDC and ADC circuits are being developed. Experimental proposals for the study of electroproduction of nucleon resonances at CEBAF, including measurements with polarized beam and targets, are being developed.

  10. The New Frontiers Academic AO Experiment

    NASA Astrophysics Data System (ADS)

    Benfield, M. P. J.; Turner, M. W.; Runyon, C. J.; Hakkila, J.

    2010-03-01

    The University of Alabama in Huntsville and the College of Charleston have embarked on an educational experiment called the Academic AO Project. This project seeks to simulate the NASA Announcement of Opportunity response process in the classroom.

  11. Next generation AO system of Subaru Telescope

    NASA Astrophysics Data System (ADS)

    Hayano, Y.

    2011-09-01

    A laser guide star adaptive optics system with 188 elements is under commissioning at Subaru Telescope. The system has been opened to every astronomer with risk from July, 2011. In parallel, we have started a conceptual study of the next generation AO system for Subaru Telescope. Based on the analysis of the line-up of other instruments at Subaru Telescope, such as Hyper Supreme Camera and Prime Focus Spectrograph, the wide coverage of field of view is the most important characteristics for our next generation AO system. Secondly, a wide field AO at 8-m class telescope will be still competitive at the era of extreme large telescopes. A conceptual study of a ground-layer AO and multi-object AO at Subaru Telescope is introduced in this presentation. It includes performance simulation of both GLAO and MOAO with Subaru Telescope and expected gain in sensitivity and angular resolution for various astronomical targets. Instruments, which match well to a wide field AO system, in infrared wavelength are introduced as well.

  12. Standard Triaxial Ellipsoid Asteroids from AO Observations

    NASA Astrophysics Data System (ADS)

    Drummond, Jack D.; Merline, W. J.; Conrad, A.; Dumas, C.; Carry, B.

    2008-09-01

    As part of our study of resolved asteroids using adaptive optics (AO) on large telescopes (>8; m), we have identified several that can serve as Standard Triaxial Ellipsoid Asteroids (STEAs), suitable for radar and thermo-physical calibration. These objects are modeled well as triaxial ellipsoids, having: 1) small uncertainties on their three dimensions as determined with AO; 2) rotational poles well determined from both lightcurves and AO; and 3) good sidereal periods from lightcurves. Although AO allows the opportunity to find an asteroid's dimensions and rotational pole in one night, we have developed a method to combine AO observations from different oppositions to pool into a global solution. The apparent orientation and sizes of STEAs can be predicted to within a few degrees and a few km over decades. Currently, we consider 511 Davida, 52 Europa, 2 Pallas, and 15 Eunomia as STEAs. Asteroids that are not well modeled as ellipsoids, clearly showing departures from ellipsoid figures in AO images, include 129 Antigone and 41 Daphne. We will show movies of images and models of these asteroids.

  13. The Magellan Telescope adaptive secondary AO system

    NASA Astrophysics Data System (ADS)

    Close, Laird M.; Gasho, Victor; Kopon, Derek; Hinz, Phil M.; Hoffmann, William F.; Uomoto, Alan; Hare, Tyson

    2008-07-01

    The Magellan Clay telescope is a 6.5m Gregorian telescope located in southern Chile at Las Campanas Observatory. The Gregorian design allows for an adaptive secondary mirror that can be tested off-sky in a straight-forward manner. We have fabricated a 85 cm diameter aspheric adaptive secondary with our subcontractors and partners. This secondary has 585 actuators with <1 msec response times. The chopping adaptive secondary will allow low emissivity AO science. We will achieve very high Strehls (~98%) in the Mid-IR AO (8-26 microns) with the BLINC/MIRAC4 Mid-IR science camera. This will allow the first "super-resolution" and nulling Mid-IR studies of dusty southern objects. We will employ a high order (585 mode) pyramid wavefront sensor similar to that used in the Large Binocular Telescope AO systems. The relatively high actuator count will allow modest Strehls to be obtained in the visible (~0.8?m). Our visible light AO (Vis AO) science camera is fed by an advanced ADC and beamsplitter piggy-backed on the WFS optical table. The system science and performance requirements, and an overview the design, interface and schedule for the Magellan AO system are presented here.

  14. ATST and Solar AO state of art

    NASA Astrophysics Data System (ADS)

    Rimmele, Thomas; Woeger, Friedrich; Marino, Jose

    2013-12-01

    The 4 meter aperture Advanced Technology Solar Telescope (ATST) is an ELT for solar astronomy, and as such will address a broad range of science questions that require its AO system to operate in several different observing scenarios. We review the science drivers that lead to the most demanding ATST AO system requirements, such as high Strehl ratios at visible wavelengths, MCAO correction, and photon starved, extended FOV wavefront sensing using large, faint structures at the limb of the Sun. Within the context of exisiting high-order AO systems for solar telescopes we present an overview over the current ATST AO system design and capabilities. Finally, we will describe the widely used post-facto image processing techniques of AO corrected solar imaging and spectroscopic data that are required to achieve the desired spatial resolution especially at the short end (380 nm) of the visible spectrum over ATST's full FOV. We will lay out how these techniques will be supported in the AO system to help ATST achieve its scientific goals.

  15. Into the blue: AO science with MagAO in the visible

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    We review astronomical results in the visible (λ<1μm) with adaptive optics. Other than a brief period in the early 1990s, there has been little astronomical science done in the visible with AO until recently. The most productive visible AO system to date is our 6.5m Magellan telescope AO system (MagAO). MagAO is an advanced Adaptive Secondary system at the Magellan 6.5m in Chile. This secondary has 585 actuators with < 1 msec response times (0.7 ms typically). We use a pyramid wavefront sensor. The relatively small actuator pitch (~23 cm/subap) allows moderate Strehls to be obtained in the visible (0.63-1.05 microns). We use a CCD AO science camera called "VisAO". On-sky long exposures (60s) achieve <30mas resolutions, 30% Strehls at 0.62 microns (r') with the VisAO camera in 0.5" seeing with bright R < 8 mag stars. These relatively high visible wavelength Strehls are made possible by our powerful combination of a next generation ASM and a Pyramid WFS with 378 controlled modes and 1000 Hz loop frequency. We'll review the key steps to having good performance in the visible and review the exciting new AO visible science opportunities and refereed publications in both broad-band (r,i,z,Y) and at Halpha for exoplanets, protoplanetary disks, young stars, and emission line jets. These examples highlight the power of visible AO to probe circumstellar regions/spatial resolutions that would otherwise require much larger diameter telescopes with classical infrared AO cameras.

  16. Adaptive optics (AO) and ground-layer AO for Dome C: numerical simulation results

    NASA Astrophysics Data System (ADS)

    Carbillet, M.; Maire, A.-L.; Le Roux, B.; Aristidi, E.; Giordano, C.; Pasqueron de Fommervault, O.; Gautier, J.; Trinquet, H.

    We present the latest results of our on-going closed-loop “end-to-end” numerical adaptive optics (AO) simulations concerning both a standard-AO and a three-star ground-layer AO system for a near-infrared 2-m class telescope at Dome C, Antarctica. We demonstrate that Dome C is an ideal site for wide-field AO-aided astronomy, define in details the AO system(s) optimized for the median turbulence profile considered, and finally show that a 0.3 Strehl ratio and 200-mas-wide stable point-spread function is reached in band J on at least a 15^prime-diameter field.

  17. 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.

  18. Blazar AO 0235+164 brightens in optical

    NASA Astrophysics Data System (ADS)

    Larionov, V. M.; Borman, G. A.; Jorstad, S. G.

    2014-08-01

    We perform optical photometric and polarimetric monitoring of selected gamma-ray blazars using 0.7-m AZT-8 telescope (Crimean Obs.,, Russia), LX-200 0.4-m telescope (St.Petersburg Univ., Russia) (see http://vo.astro.spbu.ru/program ) and 1.8-m Perkins telescope (Lowell Obs., AZ, USA) (http://www.bu.edu/blazars/VLBAproject.html ), partly in the frames of WEBT/GASP project.

  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 error is inferred from measurements of the point spread function (PSF). It can also be estimated by measuring known wavefront errors and comparing to the WFS measurement. Both methods will be used in the AO-OCT system. In this particular system measurement error introduced by the WFS can be caused by low light levels, poor camera sensitivity at the operating wavelength and noise introduced by heat in the uncooled CCD. Also, the gaussian beam profile of the system causes centroids near the edges of the pupil to be dimmer, and thus noisier. The easiest way to estimate measurement error is to compare successive wavefront measurements when the system is stable. This techniques will include vibrations and other systematic errors. Alternatively the measurement error can be estimated from measured signal to noise. This is more complicated but will decouple measurement errors from stability measurements. Ultimately, even if the phase is measured perfectly, performance will still be limited by the fitting error [7]. This error is inversely proportional to the number of actuators of the DM. Basically wavefront errors with spatial frequencies greater than half the number of actuators across the aperture cannot be corrected. For DMs with modal influence functions (like the AOptix Bimorph in the AO-OCT system), this translates to the number of modes which can be corrected. The AO-OCT system over-samples the wavefront, so to some extent, we can measure these out-of-band errors directly. In addition to fitting error, the DM will introduce errors based on the ability of each individual actuator to go to the position demanded by the control system. Generally this voltage step size is limited by the resolution of the drive electronics and can be calculated analytically.

  20. The Subaru Coronagraphic Extreme AO Project

    NASA Astrophysics Data System (ADS)

    Martinache, Frantz; Guyon, O.; Lozi, J.; Tamura, M.; Hodapp, K.; Suzuki, R.; Hayano, Y.; McElwain, M. W.

    2009-01-01

    While the existence of large numbers of extrasolar planets around solar type stars has been unambiguously demonstrated by radial velocity, transit and microlensing surveys, attempts at direct imaging with AO-equipped large telescopes remain unsuccessful. Because they supposedly offer more favorable contrast ratios, young systems consitute prime targets for imaging. Such observations will provide key insights on the formation and early evolution of planets and disks. Current surveys are limited by modest AO performance which limits inner working angle to 0.2", and only reach maximum sensitivity outside 1". This translates into orbital distances greater than 10 AU even on most nearby systems, while only 5 % of the known exoplanets have a semimajor axis greater than 10 AU. This calls for a major change of approach in the techniques used for direct imaging of the direct vicinity of stars. A sensible way to do the job is to combine coronagraphy and Extreme AO. Only accurate and fast control of the wavefront will permit the detection of high contrast planetary companions within 10 AU. The SCExAO system, currently under assembly, is an upgrade of the HiCIAO coronagraphic differential imaging camera, mounted behind the 188-actuator curvature AO system on Subaru Telescope. This platform includes a 1000-actuator MEMS deformable mirror for high accuracy wavefront correction and a PIAA coronagraph which delivers high contrast at 0.05" from the star (5 AU at 100 pc). Key technologies have been validated in the laboratory: high performance wavefront sensing schemes, spider vanes and central obstruction removal, and lossless beam apodization. The project is designed to be highly flexible to continuously integrate new technologies with high scientific payoff. Planned upgrades include an integral field unit for spectral characterization of planets/disks and a non-redundant aperture mask to push the performance of the system toward separations less than lambda/D.

  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. Experimental comparison of Wide Field AO control schemes using the Homer AO bench.

    NASA Astrophysics Data System (ADS)

    Parisot, Amélie; Petit, Cyril; Fusco, Thierry

    2011-09-01

    Wide Field Adaptive Optics (WFAO) concepts, such as Laser Tomography AO (LTAO) or Multi-Conjugate AO (MCAO) have been developed in order to overcome the anisoplanatism limit of classical AO. Most of the future AO-assisted instruments of ELTs rely on such concepts which have raised critical challenges such as tomographic estimation and from laser and natural guide star combined with efficient DM(s) control. In that context, the experimental validation of the various clever control solutions proposed by several teams in the past years is now essential to reach a level of maturity compatible with their implementation in future WFAO developments for ELT. The ONERA wide field AO facility (HOMER bench) has been developed for these very issues. Gathering a 3D turbulence generator, laser and natural guide stars, two deformable mirrors with variable altitude positions and a PC-based flexible and user-friendly RTC , HOMER allows the implementation and comparison of control schemes from the simplest least-square to the optimal Linear Quadratic Gaussian solutions including Virtual DM and Pseudo-closed loop approaches. After a description of the bench internal calibrations and ultimate performance, all the control schemes are compared experimentally. Their evolutions as a function of wavefront sensors SNR as well as their robustness to calibration / model errors are particularly emphasised. Finally, we derive from the previous works some specific calibrations and identifications procedures ensuring both robustness and efficiency of WFAO systems and we extrapolate their applications to the future ELT AO systems.

  3. 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.

  4. Into the Blue: AO Science in the Visible with MagAO

    NASA Astrophysics Data System (ADS)

    Close, Laird; Males, Jared; Morzinski, Katie; Kopon, Derek; Follette, Kate; Rodigas, Timothy; Hinz, Philip; Wu, Ya-Lin; Puglisi, Alfio; Esposito, Simone; Riccardi, Armando; Pinna, Enrico; Xompero, Marco; Briguglio, Runa; Uomoto, Alan; Hare, Tison

    2013-12-01

    The Magellan Clay telescope is a 6.5m Gregorian telescope located in Chile at Las Campanas Observatory. We have fabricated an 85 cm diameter aspheric adaptive secondary with our subcontractors and partners, MagAO passed acceptance tests in spring 2012, and the entire System was commissioned from Nov 17 to Dec 7, 2012. This secondary has 585 actuators with < 1 msec response times (0.7 ms typically). We fabricated a high order (585 mode) pyramid wavefront sensor (similar to that of LBT's FLAO). The relatively high actuator count allows moderate Strehls to be obtained in the visible (0.63-1.05 microns). We have built an CCD science camera called "jVisAO". On-sky long exposures (60s) achieve 30% Strehls at 0.62 microns (r') with the VisAO camera in 0.5" seeing with bright R < 8 mag stars. These relatively high optical wavelength Strehls are made possible by our powerful combination of a next generation ASM and a Pyramid WFS with 200-400 controlled modes and 1000 Hz loop frequencies. To minimize non-common path errors and enable visible AO the VisAO science camera is fed by an advanced triplet ADC and is piggy-backed on the WFS optical board itself. Despite the ability to make 25 mas images we still have ~4 mas of resolution loss to residual vibrations. We will discuss what the most difficult aspects are for visible AO on ELTs scaling from our experience with MagAO.

  5. On-sky speckle nulling with the Subaru Coronagraphic Extreme AO (SCExAO) instrument

    NASA Astrophysics Data System (ADS)

    Martinache, Frantz; Guyon, Olivier; Jovanovic, Nemanja; Clergeon, Christophe; Singh, Garima; Kudo, Tomoyuki

    2014-08-01

    Contrast limit for the direct imaging of extrasolar planets from ground based adaptive optics (AO) observations is set by the presence of static and slow-varying aberrations in the optical path that lead to the science instrument. To complement the otherwise highly successful angular differential imaging (ADI) technique toward small angular separation, we propose to employ additional wavefront control to modulate the diffraction. This flexible approach introduces enough diversity to discriminate genuine structures of the observed target from spurious diffraction features in the image. One possible implementation of such form of coherence differential imaging (CDI) is a speckle nulling algorithm that iteratively suppresses diffraction features inside a region constrained by the number of active elements of the deformable mirror modulating the wavefront, and the coronagraph. This paper presents on-sky results obtained with this approach, on the Subaru Coronagraphic Extreme AO (SCExAO) instrument.

  6. The Magellan Telescope Adaptive Secondary AO System: a visible and mid-IR AO facility

    NASA Astrophysics Data System (ADS)

    Close, Laird M.; Gasho, Victor; Kopon, Derek; Males, Jared; Follette, Katherine B.; Brutlag, Kevin; Uomoto, Alan; Hare, Tyson

    2010-07-01

    The Magellan Clay telescope is a 6.5m Gregorian telescope located in Chile at Las Campanas Observatory. The Gregorian design allows for an adaptive secondary mirror that can be tested off-sky in a straightforward manner. We have fabricated a 85 cm diameter aspheric adaptive secondary with our subcontractors and partners, the ASM passed acceptance tests in July 2010. This secondary has 585 actuators with <1 msec response times (0.7 ms typically). This adaptive secondary will allow low emissivity AO science. We will achieve very high Strehls (~98%) in the Mid-IR (3-26 microns) with the BLINC/MIRAC4 Mid-IR science camera. This will allow the first "super-resolution" and nulling Mid-IR studies of dusty southern objects. We will employ a high order (585 mode) pyramid wavefront sensor similar to that now successfully used at the Large Binocular Telescope. The relatively high actuator count will allow modest Strehls to be obtained in the visible (0.63-1.05 ?m). Moderate (~20%) Strehls have already been obtained at 0.8 ?m at the LBT with the same powerful combination of a next generation ASM and Pyramid WFS as we are providing for Magellan. Our visible light AO (VisAO) science camera is fed by an advanced triplet ADC and is piggy-backed on the WFS optical board. We have designed an additional "clean-up" very fast (2 kHz) tilt stabilization system for VisAO. Also a high-speed shutter will be used to block periods of poor correction. The VisAO facility can be reconfigured to feed an optical IFU spectrograph with 20 mas spaxels. The entire system passed CDR in June 2009, and is now finished the fabrication phase and is entering the integration phase. The system science and performance requirements, and an overview the design, interface and schedule for the Magellan AO system are presented here.

  7. 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 estudar o tema Astronom! ia entre os educandos.

  8. Measuring Atmospheric Dynamics on Titan with AO

    NASA Astrophysics Data System (ADS)

    Adamkovics, Mate; de Pater, I.; Hartung, M.

    2009-05-01

    The cycling of fluid methane between Titan's atmosphere and surface, via seemingly familiar meteorological phenomena, is often compared to Earth's hydrology. Near-IR observations with AO resolve the moon's 1" disk, measure spatial variation in both the surface reflectivity and scattering in the atmosphere, and constrain the methane cycle. Forward models of the atmosphere are compared to observations and used to identify and quantify sources and altitudes of atmospheric opacity; including aerosols, clouds, and precipitation. The ubiquitous submicron aerosol hazes are tracers of global stratospheric dynamics over yearly timescales. Cloud properties may constrain the tropospheric circulation and are observed to change on hourly, daily, and seasonal timescales. Here we present observations of the daily life-cycle of a cloud system, a signature of tropospheric precipitation, seasonal changes in aerosol, and discuss the models that are used to quantify the observed meteorology.

  9. 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.

  10. Low-order AO system in LAMOST

    NASA Astrophysics Data System (ADS)

    Yuan, Xiangyan; Cui, Xiangqun; Liu, Genrong; Zhang, Yong; Qi, Yongjun

    2006-06-01

    The large sky area multi-object fiber spectroscopic telescope (LAMOST) is a special reflecting Schmidt telescope with its main optical axis on the meridian plane tilted by an angle of 25° to the horizontal. The clear aperture is 4m, working in optical band. The light path is 60m long when working in observing mode and it will be doubled if work in auto-collimation mode. So the image quality is affected clearly by the ground seeing and the dome seeing. In order to improve the seeing condition of the long light path, we enclosed the spherical primary and the focus unit in a tunnel enclosure and cooled the tunnel. This is an effective but passive method. Corresponding experiments and simulations show the main part of the aberrations caused by the ground seeing and dome seeing is slowly changed low order items such as tip-tilt, defocus, astigmatism, coma and spherical aberration. Thus we plan to develop the low-order AO system based on the low-cost 37-channel OKO deformable mirror for the telescope to better the ground seeing and the dome seeing, not aimed to reach diffraction limited image. This work is being carried on now.

  11. 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.

  12. Io's Corona: Asymmetries and AO Observations

    NASA Astrophysics Data System (ADS)

    Schneider, N. M.; Burger, M. H.; Sutton, S. E.; Dubson, M. A.

    2003-05-01

    Io's corona is the critical link between Io's atmosphere and the plasma torus. This region, from the exobase to the Hill sphere at about 6 RIo, has now been studied in enough detail to search for temporal variations, spatial asymmetries, and differences between atomic species. Our mutual eclipse observations reveal a relatively stable sodium corona with a significant asymmetry: Io's sub-Jupiter side is 50% brighter than the anti-Jupiter side (Burger et al., ApJ 563, 2001). We also find that Io's sodium corona falls off more steeply than the oxygen corona (measured by HST, Wolven et al., JGR 106, 2001). This effect exceeds that expected from their different ionization potentials, and is better explained by electron cooling near Io. Despite the promise of coronal studies, observations to date have required either the UV capability of HST or satellite mutual eclipses occurring every six years. We have undertaken an adaptive optics study of sodium in Io's corona to allow more routine diagnostic observations. Standard groundbased imaging suffers from the inevitable blurring of Io's 1.2"-wide disk with the 6" corona, fainter by up to 4 orders of magnitude. AO has the potential of imaging the corona by limiting the blurring of Io's disk. We will report on observations using the Air Force's 3.67m AEOS telescope at Haleakala, Maui, and our efforts to measure coronal emissions through rigorous differencing of on-band and off-band images. This work has been supported by NASA's Planetary Astronomy program and NSF's Advanced Technology and Instrumentation program.

  13. 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 preliminary design.

  14. First closed-loop visible AO test results for the advanced adaptive secondary AO system for the Magellan Telescope: MagAO's performance and status

    NASA Astrophysics Data System (ADS)

    Close, Laird M.; Males, Jared R.; Kopon, Derek A.; Gasho, Victor; Follette, Katherine B.; Hinz, Phil; Morzinski, Katie; Uomoto, Alan; Hare, Tyson; Riccardi, Armando; Esposito, Simone; Puglisi, Alfio; Pinna, Enrico; Busoni, Lorenzo; Arcidiacono, Carmelo; Xompero, Marco; Briguglio, Runa; Quiros-Pacheco, Fernando; Argomedo, Javier

    2012-07-01

    The heart of the 6.5 Magellan AO system (MagAO) is a 585 actuator adaptive secondary mirror (ASM) with <1 msec response times (0.7 ms typically). This adaptive secondary will allow low emissivity and high-contrast AO science. We fabricated a high order (561 mode) pyramid wavefront sensor (similar to that now successfully used at the Large Binocular Telescope). The relatively high actuator count (and small projected ~23 cm pitch) allows moderate Strehls to be obtained by MagAO in the “visible” (0.63-1.05 μm). To take advantage of this we have fabricated an AO CCD science camera called "VisAO". Complete “end-to-end” closed-loop lab tests of MagAO achieve a solid, broad-band, 37% Strehl (122 nm rms) at 0.76 μm (i’) with the VisAO camera in 0.8” simulated seeing (13 cm ro at V) with fast 33 mph winds and a 40 m Lo locked on R=8 mag artificial star. These relatively high visible wavelength Strehls are enabled by our powerful combination of a next generation ASM and a Pyramid WFS with 400 controlled modes and 1000 Hz sample speeds (similar to that used successfully on-sky at the LBT). Currently only the VisAO science camera is used for lab testing of MagAO, but this high level of measured performance (122 nm rms) promises even higher Strehls with our IR science cameras. On bright (R=8 mag) stars we should achieve very high Strehls (>70% at H) in the IR with the existing MagAO Clio2 (λ=1-5.3 μm) science camera/coronagraph or even higher (~98% Strehl) the Mid-IR (8-26 microns) with the existing BLINC/MIRAC4 science camera in the future. To eliminate non-common path vibrations, dispersions, and optical errors the VisAO science camera is fed by a common path advanced triplet ADC and is piggy-backed on the Pyramid WFS optical board itself. Also a high-speed shutter can be used to block periods of poor correction. The entire system passed CDR in June 2009, and we finished the closed-loop system level testing phase in December 2011. Final system acceptance (“pre-ship” review) was passed in February 2012. In May 2012 the entire AO system is was successfully shipped to Chile and fully tested/aligned. It is now in storage in the Magellan telescope clean room in anticipation of “First Light” scheduled for December 2012. An overview of the design, attributes, performance, and schedule for the Magellan AO system and its two science cameras are briefly presented here.

  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 one of the authors (EMB) suggests it may require consideration of a non-cosmological component of redshift in AO 0235+164.

  16. 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.

  17. 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.

  18. A Tilted-Trough Mechanism for AO/NAO

    NASA Astrophysics Data System (ADS)

    Jin, F.; Kimoto, M.; Watanabe, M.; Pan, L.; Yasutomi, N.

    2001-12-01

    The least damped mode of the linear atmospheric dynamic system with the zonal mean flow interacting with stationary waves is shown to bear much resemblance to the observed Arctic Oscillation (AO)in terms of both zonal and associated stationary wave components. This AO-like mode results from the dynamic self-organization among the components of zonal mean flow and the associated stationary waves through a so-called tilted-trough positive feedback. Namely, the anomalous AO-like sheared zonal flow generates the associated anomaly in stationary waves in such a way that the tilts of the total stationary waves are altered to reinforce the sheared zonal-flow anomaly through the anomalous momentum flux convergence. Thus the AO-like least damped mode, which can be excited by surface or other forcing, is expected to be dominant over monthly and longer time scales.

  19. A Large-Telescope Natural Guide Star AO System

    NASA Technical Reports Server (NTRS)

    Redding, David; Milman, Mark; Needels, Laura

    1994-01-01

    None given. From overview and conclusion:Keck Telescope case study. Objectives-low cost, good sky coverage. Approach--natural guide star at 0.8um, correcting at 2.2um.Concl- Good performance is possible for Keck with natural guide star AO system (SR>0.2 to mag 17+).AO-optimized CCD should b every effective. Optimizing td is very effective.Spatial Coadding is not effective except perhaps at extreme low light levels.

  20. 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 yr respectively. These ages are a factor of three to four times greater than their respective characteristic ages. The calculated braking index is close to unity as compared to three for the vacuum dipole model and 2.5--2.8 as measured for young pulsars. I conclude this section by describing a search for NIR counterparts of new magnetars and a future promise of polarimetric investigation of a magnetars' NIR emission mechanism.

  1. 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.

  2. 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.

  3. 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

  4. LGS-AO: the making of a star for astronomy.

    NASA Astrophysics Data System (ADS)

    Le Mignant, D.

    2005-12-01

    For astronomers, it all started in 1985 when Foy and Labeyrie (1985, A&A, 152, L29)published the concept of creating a laser guide star (LGS) in the mesospheric layer of the atmosphere to extend the use of adaptive optics (AO) to a much larger fraction of the astronomical sky. Shortly thereafter, the first sodium wavelength laser beam was propagated from Mauna Kea to validate the LGS concept (Thompson & Gardner 1987, Nature, 328, 229). In 1991, the results from the research undertaken by the U.S. Dept. of Defence were published in the open literature (Fugate et al. 1991, Nature, 353, 144). Experiments were subsequently performed at a number of Observatories (Apache Point, MMT, Calar Alto & Lick) resulting in one operational LGS-AO facility on the Lick 3-m telescope (Max et al. 1997, Science, 277, 1649). Today, Keck II LGS-AO, the first operational LGS-AO facility on an 8-10-m class telescope, is paving a new road for astronomical science by providing very high angular resolution (FWHMs of 50-60 mas with Strehls of 20-35% at K) over half of the sky. AO-corrected imagers and spectrographs at Keck and elsewhere will soon be used by a wider community of astronomers to complement and frequently surpass the observations obtained from space. We will present a review and a discussion of this powerful new instrumentation: the exciting scientific showcases and the challenges for combining complicated dynamic systems into productive, reliable and user-friendly instrumentation. We will provide an update on the forthcoming LGSAO intruments at other major observatories. We will report on the image quality performance, as well as on-sky observing efficiency, for the Keck II system (Wizinowich et al. 2005, PASP, submitted). As many astronomers plan for "AO all-the-time" on large and extremely large telescope, this talk will provide some information and lessons learned for how to best prepare for the bright LGS-AO future.

  5. 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).

  6. On random walk de Lvy aplicado aos mapas de varincias

    NASA Astrophysics Data System (ADS)

    Klafke, J. C.

    2003-08-01

    Uma pergunta que surge ao nos confrontarmos com os mapas de varincias, ou s-Maps [Klafke, J. C. "Estudo da Difuso Catica em Ressonncias Asteroidais", Tese de Doutorado, IAG/USP, 2002] diz respeito ao contedo fsico de tais representaes do espao de fase. Ou seja, o que representa as varincias das aes obtidas para uma determinada condio inicial e como relacion-las com o tempo de difuso das rbitas, supondo-se que estas de fato estejam envolvidas em um processo difusivo? Para discutirmos essa questo, lanamos mo da modelagem dos processos estocsticos subjacentes s varincias determinadas e implementamos uma srie de simulaes do tipo Monte Carlo a partir das informaes registradas nos s-Maps calculados para algumas ressonncias asteroidais bem estudadas (p.ex. 3: 1, 2: 1 e 3: 2). Para tanto, temos usado uma funo de densidade de probabilidade gaussiana ao definir os n passos que permitiro estabelecer uma relao direta entre o Mapa de Difuso e o Mapa de Varincias. Contudo, os resultados obtidos at agora tem subestimado o tempo de difuso esperado para os fenmenos conhecidos. Tal se deve ao fato de que, no processo difusivo real, possvel existirem passos de comprimento consideravelmente maiores que a mdia estabelecida pelas distribuies gaussiana ou normal, sobretudo quando se cruza uma regio catica. Neste trabalho, apresentamos os resultados comparativos de simulaes de Monte Carlo com base no random walk de Lvy [Klafter, J. et al. 2002. "Beyond Brownian motion", Phys. Today, Feb, 33-39.], o qual possibilita passos espordicos de comprimento acima do valor mdio (saltos) permitindo estabelecer uma escala de tempo mais prxima da esperada para a difuso.

  7. 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.

  8. Laboratory demonstration of real time frame selection with Magellan AO

    NASA Astrophysics Data System (ADS)

    Males, Jared R.; Close, Laird M.; Kopon, Derek; Quiros-Pacheco, Fernando; Riccardi, Armando; Xompero, Marco; Puglisi, Alfio; Gasho, Victor; Morzinski, Katie M.; Follette, Katherine B.

    2012-07-01

    The Magellan AO system combines a pyramid wavefront sensor and high-order adaptive secondary mirror, and will see first light on the Magellan Clay telescope in November 2012. With a 24 cm projected actuator pitch, this powerful system will enable good correction in the optical (0.5 to 1 μm). Realistic laboratory testing has produced Strehl ratios greater than 40% in i’ (0.765 μm) on bright simulated stars. On fainter stars our visible AO camera, VisAO, will work in the partially corrected regime with only short moments of good correction. We have developed a form of lucky imaging, called real time frame selection, which uses a fast shutter to block moments of bad correction, and quickly opens the shutter when the correction is good, enabling long integrations on a conventional CCD while maximizing Strehl ratio and resolution. The decision to open or shut is currently based on reconstructed WFS telemetry. Here we report on our implementation and testing of this technique in the Arcetri test tower in Florence, Italy, where we showed that long exposure i’ Strehl could be improved from 16% to 26% when the selection threshold was set to the best 10% of instantaneous Strehl.

  9. 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.

  10. 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.

  11. Physical characteristics of the Blazar AO 0235+164

    NASA Astrophysics Data System (ADS)

    Vol'vach, A. E.; Larionov, M. G.; Vol'vach, L. N.; Lähteenmäki, A.; Tornikoski, M.; Aller, M. F.; Aller, H. D.; Sasada, M.

    2015-02-01

    Long series of multi-frequency monitoring data of the active galactic nucleus (AGN) AO 0235+164 from the radio to the gamma-ray are analyzed. AO 0235+164 may be a close binary system comprised of two supermassive black holes (SMBHs). A harmonic analysis has established the presence of orbital and precessional periods of two and eight years, respectively. These values are close to the analogous periods found in other AGNs that have been proposed to be close SMBH binary systems in a stage of their evolution close to coalescence. A cross-correlation analysis is used to find the time delay between corresponding flares occurring in different wavebands. The empirical dependence found earlier for a number of other AGNS relating the delay in the flux variations with the frequency is observed for this object, and has the form of an inverse logarithmic dependence, providing evidence that the flux variability of AGNs at centimeter and shorter wavelengths is intrinsic. The standard picture of jet activity of AGNs supposes plasma formations that move from the central regions along outflows, becoming optically thin at longer and longer wavelengths as they do so. The physical and dynamical characteristics of AO 0235+164 suggest it is a close binary with SMBHs with similar masses of the order of 1010 M ⊙. This is one of the most massive systems of two SMBHs. The velocities of the companion and central black hole about their common center of mass are estimated to be 104 and 5×103 km/s. The results obtained suggest that observed bright AGNs form a relatiavely rare population among massive elliptical galaxies, due to their narrowly directed emission and their short lifetimes.

  12. Aspect-Oriented Business Process Modeling with AO4BPMN

    NASA Astrophysics Data System (ADS)

    Charfi, Anis; Müller, Heiko; Mezini, Mira

    Many crosscutting concerns in business processes need to be addressed already at the business process modeling level such as compliance, auditing, billing, and separation of duties. However, existing business process modeling languages including OMG's Business Process Modeling Notation (BPMN) lack appropriate means for expressing such concerns in a modular way. In this paper, we motivate the need for aspect-oriented concepts in business process modeling languages and propose an aspect-oriented extension to BPMN called AO4BPMN. We also present a graphical editor supporting that extension.

  13. 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

  14. Stream-Field Interactions in the Magnetic Accretor AO Piscium

    NASA Astrophysics Data System (ADS)

    Hellier, Coel; van Zyl, Liza

    2005-06-01

    UV spectra of the magnetic accretor AO Psc show absorption features for half the binary orbit. The absorption is unlike the wind-formed features often seen in similar stars. Instead, we attribute it to a fraction of the stream that overflows the impact with the accretion disk. Rapid velocity variations can be explained by changes in the trajectory of the stream depending on the orientation of the white dwarf's magnetic field. Hence, we are directly observing the interaction of an accretion stream with a rotating field. We compare this behavior to that seen in other intermediate polars and in SW Sex stars.

  15. d-AO spherical aromaticity in Ce6 O8.

    PubMed

    Yu, Xiaohu; Oganov, Artem R; Popov, Ivan A; Boldyrev, Alexander I

    2016-01-01

    After the first introduction of ? aromaticity in chemistry to explain the bonding, structure, and reactivity of benzene and its derivatives, this concept was further applied to many other compounds featuring other types of aromaticity (i.e., ?, ?). Thus far, there have been no reports on d-AO-based spherical ? aromaticity. Here, we predict a highly stable bare Ce6 O8 cluster of a spherical shape using evolutionary algorithm USPEX and DFT?+?U calculations. Natural bond orbital analysis, adaptive natural density partitioning algorithm, electron localization function, and partial charge plots demonstrate that bare Ce6 O8 cluster exhibits d-AO spherical ? aromaticity, thus explaining its exotic geometry and stability. Ce6 O8 complex plays an important role in many reactions and is known to exist in many forms, such as in NH4 [Ce6 (?(3) O)5 (?(3) OH)3 (?(2) -C6 H5 COO)9 (NO3 )3 (DMF)3 ]*DMF*H2 O compound, which is prepared under room temperature, and acts as an oxidizing agent. 2015 Wiley Periodicals, Inc. PMID:26284694

  16. 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

  17. Development of a dichroic beam splitter for Subaru AO188

    NASA Astrophysics Data System (ADS)

    Minowa, Yosuke; Takami, Hideki; Watanabe, Makoto; Hayano, Yutaka; Miyake, Masaaki; Iye, Masanori; Oya, Shin; Hattori, Masayuki; Murakami, Naoshi; Guyon, Olivier; Saito, Yoshihiko; Itoh, Meguru; Colley, Stephen; Dinkins, Matthew; Eldred, Michael; Golota, Taras

    2008-07-01

    We have developed a dichroic beam splitter for the Subaru AO188, which reflects optical light (0.4-0.9 μm) for wavefront sensing and transmits near-infrared light (0.93-5.2 μm) for science observations. The beam splitter is made of 145mm × 200mm calcium fluoride substrate coated by fluoride and metal chalcogen compound multilayer, which should be a best way to realize high transmittance over wide wavelength range in the near infrared. However, since typical fluoride soft coating is less resistant to the moisture in the air, the fluoride coating become damaged as we use on the AO188 optical bench which is placed in the room temperature condition. We have performed several accelerated endurance tests of the beam splitter under high-humidity condition by changing the design of the coatings, and found an optimal solution with an oxide protection layer which prevents the damage of the dichroic coating and keeps high transmittance at near-infrared wavelength. In this paper, we report the results of the endurance tests and the performance of our dichroic beam splitter.

  18. Nao/ao Variability In The Coupled Bergen Climate Model

    NASA Astrophysics Data System (ADS)

    Sorteberg, A.; Furevik, T.; Bentsen, M.; Drange, H.; Kvamsto, N. G.; Thorstensen-Kindem, I.

    A new fully coupled atmosphere-ocean-sea ice model, known as the Bergen Climate Model (BCM), has been developed. The coupled model can be run with stretched co- ordinates both in the atmosphere and ocean and consists of the atmospheric model ARPEGE/IFS, and a global version of the isopycnal ocean model MICOM, including a sea ice model. The atmospheric model ARPEGE/IFS (c22) is a spectral model devel- oped jointly by Meteo-France and the European Centre for Medium-Range Weather Forecasts (ECMWF). The ocean circulation model is the Miami Isopycnic Coordinate Ocean Model (MI- COM). Several modifications have been done to the MICOM model including the incorporation of a thermodynamic and dynamic sea ice model, the use of tempera- ture as a prognostic variable instead of salinity, and the use of a metric scale factor in both lateral, so the model can easily be configured on a general orthogonal grid. Also,the thickness diffusion has been modified to better handle diffusion near bottom topography and the base of the mixed layer. Coupling has been done with the library OASIS where 14 different fields are ex- changed using Montecarlo mapping and subgrid interpolation. Continental runoff into the correct rivers and discharge into the correct ocean grid cells are performed using the Total Runoff Integrating Pathways (TRIP) data set. Results will be present from a 300 years flux adjusted control integration of BCM with todays climate, using a unstretched T63 truncation in the atmosphere and a 0.8 by 2.4 degree resolution (near the equator gradually transforming to approximate square grid cells towards the poles) in the ocean. The model output has been analysed for large scale variability in both the ocean and atmosphere, with emphasise on the North Atlantic and Arctic climate. Statistical properties of the NAO/AO signal, and its im- pacts on the climate components, are identified and compared with observations. The NAO/AO mode of variability show up in the model with realistic amplitudes and fre- quencies in both 2m temperature and SLP and emphasis will be placed on evaluation of the models ability to reproduce known relations between different meteorological variables and the NAO/AO signal.

  19. NFIRAOS: first facility AO system for the Thirty Meter Telescope

    NASA Astrophysics Data System (ADS)

    Herriot, Glen; Andersen, David; Atwood, Jenny; Boyer, Corinne; Byrnes, Peter; Caputa, Kris; Ellerbroek, Brent; Gilles, Luc; Hill, Alexis; Ljusic, Zoran; Pazder, John; Rosensteiner, Matthias; Smith, Malcolm; Spano, Paolo; Szeto, Kei; Véran, Jean-Pierre; Wevers, Ivan; Wang, Lianqi; Wooff, Robert

    2014-07-01

    NFIRAOS, the Thirty Meter Telescope's first adaptive optics system is an order 60x60 Multi-Conjugate AO system with two deformable mirrors. Although most observing will use 6 laser guide stars, it also has an NGS-only mode. Uniquely, NFIRAOS is cooled to -30 °C to reduce thermal background. NFIRAOS delivers a 2-arcminute beam to three client instruments, and relies on up to three IR WFSs in each instrument. We present recent work including: robust automated acquisition on these IR WFSs; trade-off studies for a common-size of deformable mirror; real-time computing architectures; simplified designs for high-order NGS-mode wavefront sensing; modest upgrade concepts for high-contrast imaging.

  20. 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.

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

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The prelaunch photograph shows the Inter planetary Dust Experiment (IDE) in a three (3) inch deep corner tray. The IDE is an active exper iment and is located on the earth facing end of the LDEF in the G10 location. AO201 - The Interplanetary Dust Experiment (IDE) is an active experiment consisting of impact detectors, detector frames, a solar sensor and the necessary mounting hardware. The eighty (80) detectors, metal-oxide-silicon (MOS) capacitor-type impact sensors, bonded into anodized alumi num frames, are attached to the aluminum mounting plate with non-magnetic stainless steel fas teners. A solar sensor, four (4) silicon solar cells in series mounted on an aluminum baseplate, is shown in the approximate center of the IDE mounting plate. The different colors seen on the detectors are the reflections of LDEF technicians and the surrounding clean room work area.

  2. 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.

  3. Le contenu baryonique de l'univers révélé par les raies d'absorption dans le spectre des quasars

    NASA Astrophysics Data System (ADS)

    Petitjean, P.

    The baryons in the universe from quasar absorption line systems. Although steady progress is made towards detecting faint objects in emission, the high-redshift objects detected this way up to now are drawn from a particular population of powerful emitters. On the contrary, any standard object such as normal galaxies or intergalactic gaseous clouds close enough to the line of sight to high redshift quasars may be detectable by the absorption that it produces in the spectrum of the background quasar. The complete range of redshift is accessible from zero to the highest QSO redshift z=4.897. Absorption line systems observed in QSO spectra are generally classified into three categories. (1) The metal-line systems in which a large number of elements, in different ionization stages, is observed, from C{I} to C{IV} or O{I} to O{VI}. The Lyman limit systems (LLS) are optically thick at the H{I} Lyman limit (912 Å) and have therefore H{I} column densities N(H{I}) > 2× 10^{17} cm^{-2}. They are closely related, at any redshift, to galaxies. The latter have been detected by direct imaging and follow-up spectroscopy at low and intermediate redshift. Studying their number density and physical properties (kinematics, ionization state, abundances) is then a unique tool to trace galaxy formation. Among these systems, the rare damped systems, characterized by a very large H I column density (N(H{I}) > 2× 10^{20} cm^{-2}) are often considered to be associated with galactic or proto-galactic disks. (2) The hydrogen Ly α lines with no or very few metals detected at the same redshift, are of intergalactic origin at high redshift but could somehow be associated with galaxies at low redshift. Information about these systems (column density, Doppler parameter, kinematics, clustering) is derived from line-profile fitting. The latter requires high-resolution high-quality spectra that are difficult to obtain on 4m-class telescopes. Recent studies of absorptions coincident in redshift in the spectra of gravitationally lensed QSO images or QSO pairs have shown that the mean radius of the absorbers perpendicular to the line of sight is surprizingly large (up to 500 kpc). The idea that the Ly gas could trace the potential wells of dark matter and thus reveal its characteristical filamentary structure has been successfully investigated using N-body simulations. This has opened the prospect to study the cosmological evolution of the spatial distribution of the diffuse baryonic matter. (3) The broad absorption line (BAL) systems are characterized by impressive absorption troughs from different ions of low and high excitation, extending from 0 up to 60000 km s^{-1} outflow velocity relative to the QSO emission redshift. It is widely accepted that the gas is very close to the centre of the QSO host-galaxy and may be part of the broad emission line region. These systems are intimately related to the AGN phenomenon which is an important ingredient of galaxy formation. The amount of information derived from studies of QSO absorption line systems has increased tremendously in the last few years. This largely results from improvement of instrumental sensitivity, and spectral resolution and extension of the accessible wavelength range. Coupled with the development of sophisticated N-body simulations, this progress has favored the emergence of a consistent picture in which not only the intergalactic medium is the baryonic reservoir for galaxy formation but also galaxy formation strongly influences the evolution of the intergalactic medium through metal enrichment and ionizing radiation emission. One of the most exciting and promizing projects for the next few years may be to probe the 3D spatial distribution of the diffuse gas at high redshift. A number of large surveys are underway or planed, which will provide a large number of bright (m{V}<19) quasars for investigation of large scales. A few small fields will be searched for deeper samples of quasars (m{V}<23). If a hundred of lines of sight can be observed in one square degree, the probability distribution function of the matter density could be investigated at high redshift. This would be a unique way to study how galaxy formation is related to the distribution and dynamics of the underlying matter field. Même si des progrès considérables ont été faits ces dernières années dans l'observation d'objets à grand décalage spectral, ceux qui sont détectés par leur émission sont issus d'une population d'émetteurs puissants. Au contraire, n'importe quel objet aussi anodin qu'une galaxie normale ou un nuage intergalactique, se trouvant interposé entre nous et un quasar de grand décalage spectral, engendre une absorption dans le spectre du quasar. Ainsi, les raies d'absorption dans le spectre des quasars permettent de sonder l'univers sur toute la ligne de visée de notre époque (z=0) jusqu'au décalage spectral du plus éloigné des quasars (actuellement z=4,897). Les systèmes d'absorption sont généralement classés en trois catégories. (1) Les systèmes contenant des éléments lourds (différents de l'hydrogène et l'hélium) pour lesquels des raies de nombreux ions peuvent être détectées, de C{I} à C{IV} ou de O{I} à O{VI}. Parmi ceux-ci, les systèmes optiquement épais à la limite de Lyman sont souvent associés à des galaxies que l'on détecte facilement jusqu'à des décalages spectraux de l'ordre de z thicksim 1. Les systèmes plus rares possédant une très forte densité de colonne (N(H{I}) > 2× 10^{20} cm^{-2}), que l'on appelle les systèmes lorentziens sont, à grand décalage spectral, probablement associés à des disques proto-galactiques. (2) Les systèmes de la forêt Lyman α sont très nombreux et ne contiennent que très peu d'éléments lourds. Ils sont associés à du gaz remplissant le milieu intergalactique. Les caractéristiques physiques des raies (paramètre Doppler, densité de colonne, regroupement) sont dérivées à partir de la modélisation de leur profil. Cela ne peut se faire que sur des données de très bonne qualité qu'il est difficile d'obtenir sur les télescopes de la classe des 4m. En utilisant des lignes de visée proches (images gravitationnelles multiples de quasars ; groupes de quasars rapprochés dans le ciel), on peut évaluer la dimension transversale des nuages qui se révèle être étonnamment grande, de l'ordre de 500 kpc. L'idée que le gaz puisse tracer le potentiel de la matière noire et se répartir le long des structures filamentaires dessinées par celle-ci a été approfondie avec succès grâce à des simulations N-corps récentes. La perspective est ouverte de pouvoir étudier l'évolution cosmologique des grandes structures de l'univers en cartographiant la matière baryonique diffuse. (3) Les systèmes à raies larges (BAL) sont caractérisés par des absorptions s'étendant sur plusieurs dizaines de milliers de kilomètres par seconde. Il s'agit certainement de gaz éjecté par le quasar, qui pourrait faire partie de la région qui émet les raies en émission larges, caractéristiques du spectre des quasars. Ces systèmes sont des sources d'information unique sur les noyaux actifs de galaxie. La quantité d'information déduite des études des systèmes de raies d'absorption dans le spectre des quasars a augmenté de façon considérable ces dernières années. Ceci est dû à l'amélioration de la sensibilité instrumentale et donc de la résolution spectrale des observations, mais aussi à l'élargissement du domaine spectral qu'il est possible d'observer. Ces progrès ont été accompagnés par le développement de simulations numériques détaillées qui ont permis l'émergence d'un modèle cohérent dans lequel le milieu intergalactique est le réservoir de gaz pour la formation des galaxies. Cette dernière en retour influence l'évolution du milieu intergalactique à travers l'éjection des éléments lourds et l'émission de rayonnements ionisants. Un des projets les plus prometteurs de ces prochaines années est de cartographier la distribution spatiale du gaz à grand décalage spectral. Les grands relevés de quasars, maintenant planifiés, vont permettre d'augmenter de façon considérable le nombre de quasars brillants connus qui seront utilisés pour révéler, grâce aux absorptions produites par le gaz, les grandes structures de l'univers. Quelques champs vont être étudiés plus en détail, dans lesquels les quasars seront recherchés jusqu'aux plus faibles luminosités. Si une centaine de lignes de visée peuvent être observées dans un degré carré, le champ de densité de la matière pourrait être reconstruit. C'est un moyen unique d'étudier comment la formation des galaxies est liée à la distribution et la dynamique du gaz dans le milieu intergalactique.

  4. 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.

  5. Ruled and holographic experiment (AO 138-5)

    NASA Technical Reports Server (NTRS)

    Bonnemason, Francis

    1993-01-01

    The AO 138-5 experiment was designed, via the FRECOPA (FRench COoperative PAyload) experiment with the aim to study the optical behavior of different diffraction gratings submitted to space vacuum long exposure and solar irradiation. Samples were ruled and holographic gratings, masters or replica, and some additional control mirrors with various coatings. The experiment was located on the B3, trailing edge of the LDEF and was protected against Atomic Oxygen flux. The experienced thermal cycling was evaluated from -23 C to 66 C during the flight, 34,000 orbits. The samples (two batches of four pieces) were located on a dedicated plate, by a pair of equivalent gratings or mirrors; optical faces were located on the external side. The plate was inside a canister, which had been opened in space for ten months. When the satellite returned to Kennedy Space Center, the remaining vacuum in the canister was still correct. The analysis focused on the triple point characterization including light efficiency, wavefront flatness quality and stray light level. Tests were conducted on control mirrors and gratings (rules and holographic master or replica) loaded but not exposed to cosmic dust or direct solar irradiations. They did not show any significant variations. Solar exposure had damaged the coating (aluminum and platinum) reflectivity in the Ultra-Violet region; the degradation is higher with the gratings, in terms of efficiency. However, wavefront flatness quality and stray light level tests revealed no additional changes.

  6. EEV CCD39 wavefront sensor cameras for AO and interferometry

    NASA Astrophysics Data System (ADS)

    DuVarney, Raymond C.; Bleau, Charles A.; Motter, Garry T.; Shaklan, Stuart B.; Kuhnert, Andreas C.; Brack, Gary; Palmer, Dean; Troy, Mitchell; Kieu, Thangh; Dekany, Richard G.

    2000-07-01

    SciMeasure, in collaboration with Emory University and the Jet Propulsion Laboratory (JPL), has developed an extremely versatile CCD controller for use in adaptive optics, optical interferometry, and other applications requiring high-speed readout rates and/or low read noise. The overall architecture of this controller system will be discussed and its performance using both EEV CCD39 and MIT/LL CCID-19 detectors will be presented. Initially developed for adaptive optics applications, this controller is used in the Palomar Adaptive Optics program (PALAO), the AO system developed by JPL for the 200' Hale telescope at Palomar Mountain. An overview of the PALAO system is discussed and diffraction-limited science results will be shown. Recently modified under NASA SBIR Phase II funding for use in the Space Interferometry Mission testbeds, this controller is currently in use on the Micro- Arcsecond Metrology testbed at JPL. Details of a new vacuum- compatible remote CCD enclosure and specialized readout sequence programming will also be presented.

  7. 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.

  8. 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.

  9. AO Capabilities at the MMT for the User

    NASA Astrophysics Data System (ADS)

    Lloyd-Hart, Michael M.

    2009-05-01

    The MMT operates a facility natural guide star (NGS) AO system. Diffraction limited imaging and medium and high resolution spectroscopy in the near IR are offered over the full isoplanatic field with the ARIES instrument.The system also offers imaging with unique sensitivity in the thermal IR from 3 to 10 microns thanks to its use of an adaptive secondary mirror. L and M band imaging is offered with Clio which has a 12x15 arcsec field of view with Nyquist sampling if the diffraction limt. Recent M band images from Clio show the planetary system around HR8799. In addition, 10 - 25 micron imaging is offered with the MIRAC camera, which may also be operated as a Bracewell nulling interferometer. In this mode, two large subapertures are defined within the pupil. Light from the two is combined so as to cancel the light from an unresolved star through destructive interference, while the environs are imaged in constructive interference. In this way, dust disks and planetary systems may be imaged with greatly improved contrast. The MMT also operates the first astronomical adaptive optics system to employ multiple laser guide stars (LGS). Its initial operational mode, ground-layer adaptive optics (GLAO), provides uniform stellar wavefront correction within the 2 arcmin diameter laser beacon constellation, routinely reducing the stellar image widths to < 0.3 arcsec in the J - K bands. An imaging camera,PISCES, is available for these bands with 2 arcmin field of view sampled at 0.1 arcsec/pixel. In addition, L and M band imaging will be available with Clio in the fall of 2009, opening up near all-sky coverage with near-diffraction limited image quality and emissivity of just 7%.

  10. 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.

  11. 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…

  12. MagAO: Status and on-sky performance of the Magellan adaptive optics system

    NASA Astrophysics Data System (ADS)

    Morzinski, Katie M.; Close, Laird M.; Males, Jared R.; Kopon, Derek; Hinz, Phil M.; Esposito, Simone; Riccardi, Armando; Puglisi, Alfio; Pinna, Enrico; Briguglio, Runa; Xompero, Marco; Quirós-Pacheco, Fernando; Bailey, Vanessa; Follette, Katherine B.; Rodigas, T. J.; Wu, Ya-Lin; Arcidiacono, Carmelo; Argomedo, Javier; Busoni, Lorenzo; Hare, Tyson; Uomoto, Alan; Weinberger, Alycia

    2014-07-01

    MagAO is the new adaptive optics system with visible-light and infrared science cameras, located on the 6.5-m Magellan "Clay" telescope at Las Campanas Observatory, Chile. The instrument locks on natural guide stars (NGS) from 0th to 16th R-band magnitude, measures turbulence with a modulating pyramid wavefront sensor binnable from 28×28 to 7×7 subapertures, and uses a 585-actuator adaptive secondary mirror (ASM) to provide at wavefronts to the two science cameras. MagAO is a mutated clone of the similar AO systems at the Large Binocular Telescope (LBT) at Mt. Graham, Arizona. The high-level AO loop controls up to 378 modes and operates at frame rates up to 1000 Hz. The instrument has two science cameras: VisAO operating from 0.5-1μm and Clio2 operating from 1-5 μm. MagAO was installed in 2012 and successfully completed two commissioning runs in 2012-2013. In April 2014 we had our first science run that was open to the general Magellan community. Observers from Arizona, Carnegie, Australia, Harvard, MIT, Michigan, and Chile took observations in collaboration with the MagAO instrument team. Here we describe the MagAO instrument, describe our on-sky performance, and report our status as of summer 2014.

  13. 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

  14. 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.

  15. 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

    2013-01-01

    The angular resolution of ground-based optical telescopes is limited by the degrading effects of the turbulent atmosphere. In the absence of an atmosphere, the angular resolution of a typical telescope is limited only by diffraction, i.e., the wavelength of interest, λ, divided by the size of its primary mirror's aperture, D. For example, the Hubble Space Telescope (HST), with a 2.4-m primary mirror, has an angular resolution at visible wavelengths of ~0.04 arc seconds. The atmosphere is composed of air at slightly different temperatures, and therefore different indices of refraction, constantly mixing. Light waves are bent as they pass through the inhomogeneous atmosphere. When a telescope on the ground focuses these light waves, instantaneous images appear fragmented, changing as a function of time. As a result, long-exposure images acquired using ground-based telescopes--even telescopes with four times the diameter of HST--appear blurry and have an angular resolution of roughly 0.5 to 1.5 arc seconds at best. Astronomical adaptive-optics systems compensate for the effects of atmospheric turbulence. First, the shape of the incoming non-planar wave is determined using measurements of a nearby bright star by a wavefront sensor. Next, an element in the optical system, such as a deformable mirror, is commanded to correct the shape of the incoming light wave. Additional corrections are made at a rate sufficient to keep up with the dynamically changing atmosphere through which the telescope looks, ultimately producing diffraction-limited images. The fidelity of the wavefront sensor measurement is based upon how well the incoming light is spatially and temporally sampled. Finer sampling requires brighter reference objects. While the brightest stars can serve as reference objects for imaging targets from several to tens of arc seconds away in the best conditions, most interesting astronomical targets do not have sufficiently bright stars nearby. One solution is to 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. PMID:23426078

  16. 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

    The angular resolution of ground-based optical telescopes is limited by the degrading effects of the turbulent atmosphere. In the absence of an atmosphere, the angular resolution of a typical telescope is limited only by diffraction, i.e., the wavelength of interest, λ, divided by the size of its primary mirror's aperture, D. For example, the Hubble Space Telescope (HST), with a 2.4-m primary mirror, has an angular resolution at visible wavelengths of ~0.04 arc seconds. The atmosphere is composed of air at slightly different temperatures, and therefore different indices of refraction, constantly mixing. Light waves are bent as they pass through the inhomogeneous atmosphere. When a telescope on the ground focuses these light waves, instantaneous images appear fragmented, changing as a function of time. As a result, long-exposure images acquired using ground-based telescopes - even telescopes with four times the diameter of HST - appear blurry and have an angular resolution of roughly 0.5 to 1.5 arc seconds at best. Astronomical adaptive-optics systems compensate for the effects of atmospheric turbulence. First, the shape of the incoming non-planar wave is determined using measurements of a nearby bright star by a wavefront sensor. Next, an element in the optical system, such as a deformable mirror, is commanded to correct the shape of the incoming light wave. Additional corrections are made at a rate sufficient to keep up with the dynamically changing atmosphere through which the telescope looks, ultimately producing diffraction-limited images. The fidelity of the wavefront sensor measurement is based upon how well the incoming light is spatially and temporally sampled1. Finer sampling requires brighter reference objects. While the brightest stars can serve as reference objects for imaging targets from several to tens of arc seconds away in the best conditions, most interesting astronomical targets do not have sufficiently bright stars nearby. One solution is to 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

  17. 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 (6) orthogonal faces of the LDEF was correlated, the Interplanetary Dust Experiment clock could be precisely calibrated. The center 1/3rd tray cover is a chromic anodized aluminum plate that protects the IDE data conditioning and control electronics mounted underneath. The cover plate also serves as a mounting platform for ten (10) individual specimen holders provided by one of the IDE investigators.The material specimen, consisting of germanium, sapphire and zinc sulfide of different sizes, shapes and colors, are bonded to the specimen holders with an RTV adhesive. The specimen holders are attached to the cover plate with stainless steel non-magnetic fasteners. The 1/3rd tray cover plate in the right hand end of the experiment tray is an aluminum plate painted white with Chemglaze II A-276 paint and used as a thermal cover for the Experiment Power and Data System (EPDS). The EPDS is a system provided by the LDEF Project Office that processes and stores, on magnetic tape, the orbital experiment and housekeeping data from six (6) experiment locations on the LDEF.

  18. 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

  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. On the relationship between age-of-air (AoA) changes and changes in residual circulation and eddy mixing

    NASA Astrophysics Data System (ADS)

    Riese, Martin; Mueller, Rolf; Stiller, Gabriele; Konopka, Paul; Ploeger, Felix

    We analyze the effects of the stratospheric residual circulation and eddy mixing on the variability of mean age of air (AoA) within the framework of the isentropic zonal mean continuity equation, based on AoA simulations with the Lagrangian chemistry transport model CLaMS. We find that throughout the stratosphere the effects of residual circulation and eddy mixing on AoA are opposite and cancel to a large degree, with the net AoA changes resulting from this delicate balance. Mixing increases AoA equatorwards of about 40 deg N, by mixing in aged mid-latitude air, and decreases AoA at higher latitudes. In the tropical and polar upper stratosphere AoA variability is dominated by the residual circulation. In the subtropics and midlatitudes AoA variability is dominated by eddy mixing and AoA is not a unique proxy for varibility in the residual circulation. The simulated AoA change during the last decade (2002-2012) shows a nonuniform pattern, with a significant AoA increase in the NH consistent with recent satellite observations obtained by MIPAS-Envisat, and decreasing AoA in the lowest stratosphere.

  1. Status update and closed-loop performance of the Magellan adaptive optics VisAO camera

    NASA Astrophysics Data System (ADS)

    Kopon, Derek; Close, Laird M.; Males, Jared; Gasho, Victor; Morzinski, Katie; Follette, Katherine

    2012-07-01

    We present laboratory results of the closed-loop performance of the Magellan Adaptive Optics (AO) Adaptive Secondary Mirror (ASM), pyramid wavefront sensor (PWFS), and VisAO visible adaptive optics camera. The Magellan AO system is a 585-actuator low-emissivity high-throughput system scheduled for first light on the 6.5 meter Magellan Clay telescope in November 2012. Using a dichroic beamsplitter near the telescope focal plane, the AO system will be able to simultaneously perform visible (500-1000 nm) AO science with our VisAO camera and either 10 μm or 3-5 μm science using either the BLINC/MIRAC4 or CLIO cameras, respectively. The ASM, PWS, and VisAO camera have undergone final system tests in the solar test tower at the Arcetri Institute in Florence, Italy, reaching Strehls of 37% in i'-band with 400 modes and simulated turbulence of 14 cm ro at v-band. We present images and test results of the assembled VisAO system, which includes our prototype advanced Atmospheric Dispersion Corrector (ADC), prototype calcite Wollaston prisms for SDI imaging, and a suite of beamsplitters, filters, and other optics. Our advanced ADC performs in the lab as designed and is a 58% improvement over conventional ADC designs. We also present images and results of our unique Calibration Return Optic (CRO) test system and the ASM, which has successfully run in closedloop at 1kHz. The CRO test is a retro reflecting optical test that allows us to test the ASM off-sky in close-loop using an artificial star formed by a fiber source.

  2. Importance of combined winter and summer Arctic Oscillation (AO) on September sea ice extent

    NASA Astrophysics Data System (ADS)

    Ogi, Masayo; Rysgaard, Søren; Barber, David G.

    2016-03-01

    We examine the influence of winter and summer Arctic Oscillation (AO) on variations in the September Arctic sea ice extent (SIE). The winter and summer atmospheric patterns associated with year-to-year variations and detrended September SIE correlate with the positive winter AO and the negative summer AO, respectively. However, the interannual variations of winter and summer AO indices after 2007 are more weakly connected with year-to-year variations in the September SIE. Since 2007, the surface air temperatures over the Beaufort, Chukchi and East Siberian Seas are related to the interannual variations of the September SIE. Recent summer atmospheric patterns associated with the September SIE correlate with the summer AO pattern, but the summer anticyclonic circulation over the Arctic favours the recent low September SIE more than the seesaw pattern between mid- and high- latitudes. Recent winters’ positive AO have not contributed to the recent low September SIE because winter anticyclonic circulation over northern Eurasia is more directly connected with recent September SIE.

  3. Building a reliable, scalable and affordable RTC for AO instruments on ELTs

    NASA Astrophysics Data System (ADS)

    Gratadour, Damien; Sevin, Arnaud; Perret, Denis; Brule, Julien

    2013-12-01

    Addressing the unprecedented amount of computing power needed by the ELTs AO instruments real-time controllers (RTC) is one of the key technological developments required for the design of the next generation AO systems. Throughput oriented architectures such as GPUs, providing orders of magnitude greater computational performance than high-end CPUs, have recently appeared as attractive and economically viable candidates since the fast emergence of devices capable of general purpose computing. However, using for real-time applications a I/0 device which cannot be scheduled nor controlled internally by the operating system but is sent commands through a closed source driver comes with a number of challenges. Building on the experience of almost real-time end-to-end simulations using GPUs, and relying on the development of the COMPASS platform, a unified and optimized framework for AO simulations and real-time control, our team has engaged into the development of a scalable, heterogeneous GPU-based prototype for an AO RTC. In this paper, we review the main challenges arising when utilizing GPUs in real-time systems for AO and rank them in terms of impact significance and available solutions. We present our strategy, to mitigate these issues including the general architecture of our prototype, the real-time core and additional dedicated components for data acquisition and distribution. Finally, we discuss the expected performance in terms of latency and jitter on the basis of realistic benchmarks and focusing on the dimensioning of the MICADO AO module RTC.

  4. First light AO system for LBT: toward on-sky operation

    NASA Astrophysics Data System (ADS)

    Esposito, S.; Tozzi, A.; Puglisi, A.; Pinna, E.; Riccardi, A.; Busoni, S.; Busoni, L.; Stefanini, P.; Xompero, M.; Zanotti, D.; Pieralli, F.

    2006-06-01

    The paper is describing the present status of the LBT first light AO system. The system design started in January 2002 and is now approaching the final test in the Arcetri solar tower. Two key features of this single conjugate AO system are the use of an adaptive secondary mirror having 672 actuators and a pyramid wavefront sensor with a maximum sampling of 30x30 subapertures. The paper is reporting about the adaptive secondary mechanical electrical and optical integration, and the wavefront sensor unit integration and acceptance test. Finally some lab test of the AO system done using an adaptive secondary prototype with 45 actuators, the so called P45 are described. The aim of these test was to get an estimate of the system limiting magnitude and to demonstrate the feasibility of a new technique able to measure AO system interaction matrix in a shortest time and with higher SNR with respect to the classical interaction matrix measurement. We are planning to use such a technique to calibrate the AO system in Arcetri and later at the LBT telescope.

  5. Toward an experimental validation of new AO concepts for future E-ELT instrumentation

    NASA Astrophysics Data System (ADS)

    El Hadi, K.; Fusco, T.; Le Roux, B.

    2012-07-01

    For the last few years, LAM has been carrying out several R&D activities in Adaptive Optics (AO) instrumentation for Extremely Large Telescopes (ELTs). In the European ELT framework, a multi-purpose AO bench is developed to allow the experimental validation of new instrumental concepts dedicated to the next generation of ELTs. It is based on the use of a Shack-Hartmann wave-front sensor in front of a 140 actuators micro-deformable mirror (Boston Micromachines), dedicated to “low orders” modes, while a Pyramid wave-front sensor (PWFS) will be combined to a Liquid Crystal Spatial Light Modulator for “high orders” correction. Both systems could be merged in a two stages AO concept allowing to study the coupling of a telescope pre-correction using a dedicated large M4 deformable mirror and a post focal high order AO system. Analysis and optimisation of the spatial and temporal splits of the AO correction between the two systems is therefore essential. Finally, we will use the world’s fastest and most sensitive camera system OCAM (developed at LAM) coupled with the pyramid , to demonstrate the concept of a fast and hyper-sensitive PWFS (up to 100x100 sub-pupils) dedicated to the first generation instruments for ELTs.

  6. Requirements Modeling with the Aspect-oriented User Requirements Notation (AoURN): A Case Study

    NASA Astrophysics Data System (ADS)

    Mussbacher, Gunter; Amyot, Daniel; Araújo, João; Moreira, Ana

    The User Requirements Notation (URN) is a recent ITU-T standard that supports requirements engineering activities. The Aspect-oriented URN (AoURN) adds aspect-oriented concepts to URN, creating a unified framework that allows for scenario-based, goal-oriented, and aspect-oriented modeling. AoURN is applied to the car crash crisis management system (CCCMS), modeling its functional and non-functional requirements (NFRs). AoURN generally models all use cases, NFRs, and stakeholders as individual concerns and provides general guidelines for concern identification. AoURN handles interactions between concerns, capturing their dependencies and conflicts as well as the resolutions. We present a qualitative comparison of aspect-oriented techniques for scenario-based and goal-oriented requirements engineering. An evaluation carried out based on the metrics adapted from literature and a task-based evaluation suggest that AoURN models are more scalable than URN models and exhibit better modularity, reusability, and maintainability.

  7. Dynamic SPECT of the brain using a lipophilic technetium-99m complex, PnAO

    SciTech Connect

    Holm, S.; Andersen, A.R.; Vorstrup, S.; Lassen, N.A.; Paulson, O.B.; Holmes, R.A.

    1985-10-01

    The lipophilic /sup 99m/Tc-labeled oxime propylene amine oxime (PnAO) should, according to recent reports behave like TTXe in the human brain. This study compares SPECT images of the two tracers in six subjects: four stroke cases, one transitory ischemic attack case and one normal subject. Technetium-99m PnAO was injected i.v. as a bolus of 15 to 25 mCi. The distribution was followed over 10-sec intervals using a highly sensitive, rapidly rotating SPECT (Tomomatic 64) and compared to 133Xe flow maps. Upon arrival of the PnAO bolus to the brain, a high uptake was found in brain tissue with high cerebral blood flow followed by rapid washout. In the stroke cases, low flow areas were equally well visualized by both tracers. Two dissimilarities were seen in the initial pictures: PnAO visualized the cerebral veins and showed a lesser contrast of gray:white matter uptake. The results suggest that PnAO has a high yet incomplete brain extraction yielding a flow dominated initial distribution with limitations mentioned.

  8. U B V RC IC photometry and modelling of AO Ser

    NASA Astrophysics Data System (ADS)

    Hambálek, Ľ.

    2015-12-01

    AO Ser is an eclipsing binary of the Algol type. We aim to present a new model of AO Ser and to justify the presence and the mode of pulsations of its primary component. We achieved these objectives by modelling our original U,B,V,RC,IC light-curves. Pulsations were investigated by means of the periodic analysis. In this way we determined fundamental (L,R,T) parameters of the binary components, their masses and the distance d=671+3-4pc to AO Ser. Our mass-ratio q=0.396 of the components is not consistent with previous estimates. We also argue that a suspected third component is not present in this system. Finally, we confirmed pulsations of the primary component and derived its more accurate period Ppuls=0.040 d. The primary pulsates in the first non-radial mode l=3.

  9. From NAOS to the SPHERE AO System for Exoplanet Detection at the VLT

    NASA Astrophysics Data System (ADS)

    Fusco, T.; Rousset, G.; Mouillet, D.; Beuzit, J.; Puget, P.; Lagrange, A.; Lacombe, F.

    The adaptive optics (AO) system NAOS has been installed at the Very Large Telescope (VLT) since end of 2001. It delivers a Strehl ratio of 60 % under average seeing conditions and bright guide stars. It can also be operated with guide stars of magnitude as high as MV > 17. Major astrophysics results have been obtained such as the first direct observation of an extra solar planet. The SPHERE instrument under study, is optimised for the regular observation of extra solar planet at the VLT. It is equipped with an extreme AO system providing a 106 contrast when coupled to a coronagraph and a differential imaging technique. The SPHERE AO system corresponds to a major technological step. The instrument should be on sky in 5 years.

  10. Gas Permeability of Foam Films Stabilized by an Alpha Olefin Sulfonate (AOS) Surfactant

    NASA Astrophysics Data System (ADS)

    Farajzadeh, R.; Krastev, R.; Zitha, P. L. J.

    2008-07-01

    In the present study we examine the basic properties of single foam films prepared from alpha (C14-C16) olefin sulfonate (AOS). The film thickness was measured as a function of the electrolyte (NaCl) concentration. Special attention was focused on the gas permeability of the films defined by permeability coefficient kf(cm/s). The influence of the film thickness and surfactant adsorption on kf was followed. Supporting surface tension experiments at different surfactant concentrations were performed to obtain the adsorption of AOS at air/aqueous solution interface at different surfactant and salt concentrations.

  11. The Subaru Coronagraphic Extreme AO High Speed and High Sensitivity Wavefront Sensors

    NASA Astrophysics Data System (ADS)

    Clergeon, Christophe; Guyon, O.; Martinache, F.; Veran, J.; Correia, C.; Garrel, V.; Jovanovic, N.

    2013-01-01

    The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system uses advanced coronagraphic technique for high contrast imaging of exoplanets and disks as close as 1 lambda/D from the host star. In addition to unusual optics, achieving high contrast at this small angular separation requires a wavefront sensing and control architecture which is optimized for exquisite control and calibration of low order aberrations. To complement the current near-IR wavefront control system driving a single MEMS type deformable mirror mounted on a tip-tilt mount, two high order and high sensitivity visible wavefront sensors have been integrated to SCEXAO: - a non modulated Pyramid wavefront sensor (CHEOPS) which is a sensitivity improvement over modulated Pyramid systems now used in high performant astronomical AO, - a non linear wavefront sensor designed in 2012 by Subaru Telescope with the collaboration of the NRC-CNRC which is expected to improve significantly the achieved sensitivity of low order aberations measurements. I will present the Cheops on sky results acquired during last SCEXAO run (November 2012) downstream the Subaru AO188 AO system and then introduce its primary laboratory performances comparison with the first built non linear curvature wavefront sensor.

  12. Repruducibility of tronzo and ao/asif classifications for transtrochanteric fractures

    PubMed Central

    Behrendt, Christian; Faleiro, Thiago Batista; Schulz, Renata Da Silva; Silva, Bianca Ortiz Da; Paula, Erivaldo Queiróz De

    2014-01-01

    Objective: To assess the reproducibility of Tronzo and AO/ASIF classifications for transtrochanteric fractures, in order to determine the most appropriate classification for clinical application, and to evaluate the influence of the level of experience of the observers in the agreement between evaluations. Methods: We selected 30 radiographic images of transtrochanteric fractures of the femur, which were presented to two groups of observers, one formed by expert physicians and the other by resident physicians. Results: When evaluated together, Tronzo classification obtained a Kappa value of 0.44. The same classification assessed by the expert group obtained a value of 0.46, while the group of residents' value was 0.44. Evaluating the AO/ASIF classification of the complete pool analysis the value found was 0.42. For the same classification, analyzed by the expert group, obtained a value of 0.41, and by the group of residents, the Kappa value achieved was 0.42. However, when analyzed in its simplified form, the AO/ASIF classification obtained Kappa values of 0.70 (pooled analysis), 0.68 (experts) and 0.72 (residents), considered concurrent. Conclusion: The AO/ASIF simplified classification showed substantial reproducibility and is, therefore, recommended as the most suitable for clinical application. The level of experience of the observers did not influence significantly the agreement between evaluations. Level of Evidence III, Diagnostic Study - Investigating a Diagnostic Test. PMID:25328437

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

    PubMed

    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. PMID:19371759

  14. Development of vibration source requirements for TMT to ensure AO performance

    NASA Astrophysics Data System (ADS)

    MacMartin, Doug; Thompson, Hugh

    2013-12-01

    In order for TMT to deliver the required adaptive optics (AO) image quality, vibrationsources throughout the observatory need to be understood and their resulting optical response characterized.The sensitivity to vibration has been determined using a finite element model of the telescopestructure and mirror segments coupled to optical models. Frequency dependent models of the AO, activeoptics and mount control systems are included allowing end-to-end assessment of vibration sourceson AO-corrected image quality; future work will improve estimates of the propagation of vibrationsfrom equipment in the summit support building and enclosure to the telescope pier. Modeling separatelypredicts effects on image jitter caused by relative rigid body motion of main optical elements, and thedynamic motion of the 492 individual primary mirror segments. These results have been used to developallocated requirements on source amplitudes at different locations and as a function of frequency, whichwill lead to subsystem design requirements (e.g. for isolation systems at various locations both in thesupport building and enclosure and on the telescope structure). In order to meet an aggressive target forthis contribution to the AO error budget, vibration forces on the telescope itself must be limited to a fewNewtons in the most sensitive frequency range of 5-20Hz; larger forces of order 100N can be toleratedfor equipment mounted off the telescope in the summit facilities building.

  15. 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.

  16. 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.

  17. 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.

  18. Improved tilt sensing in an LGS-based tomographic AO system based on instantaneous PSF estimation

    NASA Astrophysics Data System (ADS)

    Veran, Jean-Pierre

    2013-12-01

    Laser guide star (LGS)-based tomographic AO systems, such as Multi-Conjugate AO (MCAO), Multi-Object AO (MOAO) and Laser Tomography AO (LTAO), require natural guide stars (NGSs) to sense tip-tilt (TT) and possibly other low order modes, to get rid of the LGS-tilt indetermination problem. For example, NFIRAOS, the first-light facility MCAO system for the Thirty Meter Telescope requires three NGSs, in addition to six LGSs: two to measure TT and one to measure TT and defocus. In order to improve sky coverage, these NGSs are selected in a so-called technical field (2 arcmin in diameter for NFIRAOS), which is much larger than the on-axis science field (17x17 arcsec for NFIRAOS), on which the AO correction is optimized. Most times, the NGSs are far off-axis and thus poorly corrected by the high-order AO loop, resulting in spots with low contrast and high speckle noise. Accurately finding the position of such spots is difficult, even with advanced methods such as matched-filtering or correlation, because these methods rely on the knowledge of an average spot image, which is quite different from the instantaneous spot image, especially in case of poor correction. This results in poor tilt estimation, which, ultimately, impacts sky coverage. We propose to improve the estimation of the position of the NGS spots by using, for each frame, a current estimate of the instantaneous spot profile instead of an average profile. This estimate can be readily obtained by tracing wavefront errors in the direction of the NGS through the turbulence volume. The latter is already computed by the tomographic process from the LGS measurements as part of the high order AO loop. Computing such a wavefront estimate has actually already been proposed for the purpose of driving a deformable mirror (DM) in each NGS WFS, to optically correct the NGS spot, which does lead to improved centroiding accuracy. Our approach, however, is much simpler, because it does not require the complication of extra DMs, which would need to be driven in open-loop. Instead, it can be purely implemented in software, does not increase the real-time computational burden significantly, and can still provide a significant improvement in tilt measurement accuracy, and therefore in sky-coverage. In this paper, we illustrate the benefit of this new tilt measurement strategy in the specific case of NFIRAOS, under various observing conditions, in comparison with the more traditional approaches that ignore the instantaneous variations of the NGS spot profiles.

  19. 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 contraception. Improvement of sex education is necessary in order to bring down the number of TOP, as well as realizing accessible and affordable contraception, including sterilization. The number of complications around TOPs was equal to other countries where TOP is illegal. PMID:22980230

  20. Isolation and Characterization of an Agaro-Oligosaccharide (AO)-Hydrolyzing Bacterium from the Gut Microflora of Chinese Individuals

    PubMed Central

    Li, Miaomiao; Li, Guangsheng; Zhu, Liying; Yin, Yeshi; Zhao, Xiaoliang; Xiang, Charlie; Yu, Guangli; Wang, Xin

    2014-01-01

    Agarose (AP) from red algae has a long history as food ingredients in East Asia. Agaro-oligosaccharides (AO) derived from AP have shown potential prebiotic effects. However, the human gut microbes responsible for the degradation of AO and AP have not yet been fully investigated. Here, we reported that AO and AP can be degraded and utilized at various rates by fecal microbiota obtained from different individuals. Bacteroides uniformis L8 isolated from human feces showed a pronounced ability to degrade AO and generate D-galactose as its final end product. PCR-DGGE analysis showed B. uniformis to be common in the fecal samples, but only B. uniformis L8 had the ability to degrade AO. A synergistic strain, here classified as Escherichia coli B2, was also identified because it could utilize the D-galactose as the growth substrate. The cross-feeding interaction between B. uniformis L8 and E. coli B2 led to exhaustion of the AO supply. Bifidobacterium infantis and Bifidobacterium adolescentis can utilize one of the intermediates of AO hydrolysis, agarotriose. Growth curves indicated that AO was the substrate that most favorably sustained the growth of B. uniformis L8. In contrast, κ-carrageenan oligosaccharides (KCO), guluronic acid oligosaccharides (GO), and mannuronic acid oligosaccharides (MO) were found to be unusable to B. uniformis L8. Current results indicate that B. uniformis L8 is a special degrader of AO in the gut microbiota. Because B. uniformis can mitigate high-fat-diet-induced metabolic disorders, further study is required to determine the potential applications of AO. PMID:24622338

  1. One-month lead predictability of the wintertime AO using a realistic initial solar constant for a CGCM

    NASA Astrophysics Data System (ADS)

    Ahn, Joong-Bae; Kim, Hae-Jeong

    2013-04-01

    Recently, anomalous warm events and cold surges have been increasing rapidly during the boreal winter. Many investigations reported that these anomalous temperature variations are closely related with the large-scale disturbance associated with the Arctic Oscillation (AO), thus implying the importance of the AO forecasting during the season. According to previous studies, the AO is caused by various reasons such as the variations of tropical and subtropical sea surface temperature, snow cover and solar activity. This study investigates the impact of solar constant variation on the predictability of the AO in terms of one-month lead predictability of boreal winter season (DJF) AO using Pusan National University (PNU) CGCM, a participant model of APEC Climate Center (APCC) Multi Model Ensemble Seasonal Prediction System. The one-month lead hindcasts produced from a realistic initial solar constant experiment (Solar Run, SR) and from a climatological solar constant experiment (Control run, CR) are comparatively analyzed. The one-month lead hindcasts were initiated from mid-November, -December and -January of each year for the period 1980~2009. The hindcast of SR showed better skill than that of CR in terms of forecasting not only the AO index but also the atmospheric circulation pattern related with AO. The significantly improved AO forecast skill in SR resulted from the enhanced daily forecast skill of polar vortex by the SR. That is, a more realistic atmospheric response in the upper level to the realistically varying initial solar constant affected all levels of the atmosphere via stratosphere-troposphere coupling, thereby improving the AO forecast. It is worth noting that the model can raise the predictability of the AO forecast by imposing a realistic solar constant as the initial condition. Acknowledgments This work was funded by "The Korea Meteorological Administration Research and Development Program under Grant CATER 2012-3083" of South Korea.

  2. Progress report. [Dept. of Chemistry, Howard Univ

    SciTech Connect

    Not Available

    1980-01-01

    CN radicals produced in the collisions C + NO and C + N/sub 2/O were studied by laser-induced spectroscopy. Effects of an excimer laser on a CS/sub 2/ beam were also observed. The work performed is only summarized here; completed work has been published. (RWR)

  3. [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.

  4. 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.

  5. CANARY phase B: on-sky open-loop tomographic LGS AO results

    NASA Astrophysics Data System (ADS)

    Morris, Tim; Gendron, Eric; Basden, Alastair; Martin, Olivier; Osborn, James; Henry, David; Hubert, Zoltan; Sivo, Gaetano; Gratadour, Damien; Chemla, Fanny; Sevin, Arnaud; Cohen, Matthieu; Younger, Eddy; Vidal, Fabrice; Wilson, Richard; Butterley, Tim; Bitenc, Urban; Reeves, Andrew; Bharmal, Nazim; Raynaud, Henri-François; Kulcsar, Caroline; Conan, Jean-Marc; Huet, Jean-Michel; Perret, Denis; Dickson, Colin; Atkinson, David; Bailie, Tom; Longmore, Andy; Todd, Stephen; Talbot, Gordon; Morris, Simon; Rousset, Gérard; Myers, Richard

    2014-07-01

    CANARY is an on-sky Laser Guide Star (LGS) tomographic AO demonstrator that has been in operation at the 4.2m William Herschel Telescope (WHT) in La Palma since 2010. In 2013, CANARY was upgraded from its initial configuration that used three off-axis Natural Guide Stars (NGS) through the inclusion of four off-axis Rayleigh LGS and associated wavefront sensing system. Here we present the system and analysis of the on-sky results obtained at the WHT between May and September 2014. Finally we present results from the final `Phase C' CANARY system that aims to recreate the tomographic configuration to emulate the expected tomographic AO configuration of both the AOF at the VLT and E-ELT.

  6. 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.

  7. The 384-channel prototype of DM Electronics for ELT AO systems

    NASA Astrophysics Data System (ADS)

    Caputa, Kris; Atwood, Jenny; Herriot, Glen; Veran, Jean-Pierre; Spanò, Paolo; Zielinski, Adam

    2014-08-01

    High order AO subsystems of the ELT require technological advancements in the Deformable Mirror (DM) construction and corresponding improvements in the drive electronics. Advanced prototyping is currently under way at NSI-Herzberg to reduce risks of deploying untried technology in the TMT AO subsystem NFIRAOS. We have developed a 96-channel output module and constructed a sub-scale DM Electronics prototype NDME384 with 384 output channels based on 4 such modules. French DM vendor Cilas has fabricated the NFIRAOS DM Breadoboard with 360 piezoelectric actuators in a 60×6 matrix, to demonstrate the DM technology to be deployed in NFIRAOS wavefront correctors. We present the results of testing our NDME384 prototype while driving the NFIRAOS DM Breadoboard.

  8. Efficient control schemes with limited computation complexity for Tomographic AO systems on VLTs and ELTs

    NASA Astrophysics Data System (ADS)

    Petit, C.; Le Louarn, M.; Fusco, T.; Madec, P.-Y.

    2011-09-01

    Various tomographic control solutions have been proposed during the last decades to ensure efficient or even optimal closed-loop correction to tomographic Adaptive Optics (AO) concepts such as Laser Tomographic AO (LTAO), Multi-Conjugate AO (MCAO). The optimal solution, based on Linear Quadratic Gaussian (LQG) approach, as well as suboptimal but efficient solutions such as Pseudo-Open Loop Control (POLC) require multiple Matrix Vector Multiplications (MVM). Disregarding their respective performance, these efficient control solutions thus exhibit strong increase of on-line complexity and their implementation may become difficult in demanding cases. Among them, two cases are of particular interest. First, the system Real-Time Computer architecture and implementation is derived from past or present solutions and does not support multiple MVM. This is the case of the AO Facility which RTC architecture is derived from the SPARTA platform and inherits its simple MVM architecture, which does not fit with LTAO control solutions for instance. Second, considering future systems such as Extremely Large Telescopes, the number of degrees of freedom is twenty to one hundred times bigger than present systems. In these conditions, tomographic control solutions can hardly be used in their standard form and optimized implementation shall be considered. Single MVM tomographic control solutions represent a potential solution, and straightforward solutions such as Virtual Deformable Mirrors have been already proposed for LTAO but with tuning issues. We investigate in this paper the possibility to derive from tomographic control solutions, such as POLC or LQG, simplified control solutions ensuring simple MVM architecture and that could be thus implemented on nowadays systems or future complex systems. We theoretically derive various solutions and analyze their respective performance on various systems thanks to numerical simulation. We discuss the optimization of their performance and stability issues with respect to classic control solutions. We finally discuss off-line computation and implementation constraints.

  9. Enabling technologies for visible adaptive optics: the Magellan adaptive secondary VisAO camera

    NASA Astrophysics Data System (ADS)

    Kopon, Derek; Males, Jared; Close, Laird M.; Gasho, Victor

    2009-08-01

    Since its beginnings, diffraction-limited ground-based adaptive optics (AO) imaging has been limited to wavelengths in the near IR (λ>1μm) and longer. Visible AO (λ>1μm) has proven to be difficult because shorter wavelengths require wavefront correction on very short spatial and temporal scales. The pupil must be sampled very finely, which requires dense actuator spacing and fine wavefront sampling with large dynamic range. In addition, atmospheric dispersion is much more significant in the visible than in the near-IR. Imaging over a broad visible band requires a very good Atmospheric Dispersion Corrector (ADC). Even with these technologies, our AO simulations using the CAOS code, combined with the optical and site parameters for the 6.5m Magellan telescope, demonstrate a large temporal variability of visible (λ=0.7μm) Strehl on timescales of 50 ms. Over several hundred milliseconds, the visible Strehl can be as high at 50% and as low as 10%. Taking advantage of periods of high Strehl requires either the ability to read out the CCD very fast, thereby introducing significant amounts of read-noise, or the use of a fast asynchronous shutter that can block the low-Strehl light. Our Magellan VisAO camera will use an advanced ADC, a high-speed shutter, and our 585 actuator adaptive secondary to achieve broadband (0.5-1.0 μm) diffraction limited images on the 6.5m Magellan Clay telescope in Chile at Las Campanas Observatory. These will be the sharpest and deepest visible direct images taken to date with a resolution of 17 mas, a factor of 2.7 better than the diffraction limit of the Hubble Space Telescope.

  10. 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.

  11. Intensity of climate variability derived from the satellite and MERRA reanalysis temperatures: AO, ENSO, and QBO

    NASA Astrophysics Data System (ADS)

    Yoo, Jung-Moon; Won, Young-In; Jeong, Myeong-Jae; Kim, Kyu-Myong; Shin, Dong-Bin; Lee, Yu-Ri; Cho, Young-Jun

    2013-04-01

    Satellite measurements (Atmospheric InfraRed Sounder/Advanced Microwave Sounding Unit-A, MODerate resolution Imaging Spectroradiometer) and the Modern Era Retrospective-analysis for Research and Applications (MERRA) reanalysis have been utilized to analyze the relative influence of the climate variability (AO: Arctic Oscillation, ENSO: El Niño-Southern Oscillation, QBO: Quasi-Biennial Oscillation) on the zonal-mean temperature and wind variations over the globe from September 2002 to August 2011. We also extended the usage of MERRA data for the period of 1979-2011; furthermore, three climate indices of AO, NINO3.4, and QBO were used as the corresponding climate indicators. The correlations between the temperature anomalies and the climate indices indicate that the tropospheric temperature variability in the mid-latitude (30-60N) linked to both AO and ENSO has been more pronounced over ocean than over land. However, the low stratospheric temperature variability in the mid-latitude is mainly associated with ENSO and QBO. The north-south symmetric patterns over the globe are seen in the wind anomaly distributions for ENSO and QBO, but not for AO. The ENSO events are globally vigorous but also localized during the recent 9 years compared with those based on the period of 1979-2011. The tropospheric warming and stratospheric cooling phenomena during this period are more remarkable in the recent 9 years, although according to IPCC (2012). their linkage to the ENSO variability is still uncertain. The ENSO is found to have more significant impact on the tropospheric and low stratosphere temperature variability over the tropics in the recent period, consistent with more active zonal wind meridional circulations. The discrepancies between satellite observations and MERRA are also discussed. The estimated relative impact of the three major concurrent large-scale climate phenomena on regional temperature variability can be of great use in its long-term predictability.

  12. 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.

  13. The Subaru Coronagraphic Extreme AO High Speed and High Sensitivity Wavefront Sensors

    NASA Astrophysics Data System (ADS)

    Clergeon, Christophe; Guyon, Olivier; Martinache, Frantz; Veran, Jean-Pierre; Gendron, Eric; Rousset, Grard; Correia, Carlos; Garrel, Vincent

    2013-12-01

    The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system uses advanced coronagraphic technique for high contrast imaging of exoplanets and disks as close as 1 lambda/D from the host star. In addition to unusual optics, achieving high contrast at this small angular separation requires a wavefront sensing and control architecture which is optimized for exquisite control and calibration of low order aberrations. To complement the current near-IR wavefront control system driving a single MEMS type deformable mirror mounted on a tip-tilt mount, two high order and high sensitivity visible wavefront sensors have been integrated to SCEXAO: - a non modulated Pyramid wavefront sensor (CHEOPS) which is a sensitivity improvement over modulated Pyramid systems now used in high performant astronomical AO, - a non linear wavefront sensor designed in 2012 by Subaru Telescope with the collaboration of the NRC-CNRC which is expected to improve significantly the achieved sensitivity of low order aberations measurements. I will present the CHEOPS last results measured downstream the Subaru AO188 system highlighting limits of our instrument and then introduce the primary laboratory images of the first built prototype of the non linear curvature wavefront sensor.

  14. Microwelding of various metallic materials under ultravacuum (AO 138-10)

    NASA Technical Reports Server (NTRS)

    Assie, Jean Pierre; Conde, Eric

    1991-01-01

    The first finding from the AO 138-10 is that cold welding never occurred, and that microwelds didn't even affect the reference (presumably microweld prone) pairs of metals consisting of gold, silver, and chromium. The scientific disappointment from these results must be tempered by the notion of a static AO 138-10 experiment, reflecting the passive character of the global Long Duration Exposure Facility (LDEF) flight. Thus far, it has been theorized that cold welding results from the peeling of the oxide layer, that is formed in an earth environment, by the space environment since such a layer no longer grows in space. In fact, such stripping of the oxide layer supposes relative motion of the contacting materials. In the absence of such motion, as in this experiment, oxidation will preserve its integrity and continue to prevent microwelding. More bewildering is that there was no microwelding of the reference pairs. Even though AO 138-10 failed scientific expectations, as did the LDEF structure with cold welding, the positive, functional aspect to keep in mind is the safe operation of single-shot (appendage releasing and/or latching) mechanisms, unhindered by microwelding in a space vacuum, as now demonstrated by the statically representative pairs of materials. Other aspects of the experiment are discussed.

  15. 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.

  16. 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.

  17. 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.

  18. Relationship among SSW, PJO and AO in an Idealized Stratosphere-Troposphere Coupled Model

    NASA Astrophysics Data System (ADS)

    Yoden, S.; Kohma, M.; Nishizawa, S.

    2009-04-01

    Internal intraseasonal variability in the stratosphere-troposphere coupled system contains multiple time-scale variation from stratospheric sudden warming (SSW) to polar-night jet oscillation (PJO) and Arctic oscillation (AO) in the northern hemisphere winter. Relationship among SSW, PJO and AO is investigated with a 14,000-year dataset originally obtained by Nishizawa and Yoden (2005), who performed numerical time integrations of an idealized stratosphere-troposphere global circulation model with sinusoidal surface topography of zonal wavenumber one under a purely periodic annual forcing. Deviation of the pole temperature at 2.6 hPa from the minimum value for each calendar day is analyzed to identify an SSW event with two threshold temperatures, following the analysis procedure introduced by Naito et al. (2003). Statistics of some characteristic values such as the maximum temperature during each SSW event and length of the event are calculated and their seasonal dependence is clarified. As for PJOs, fundamentally the same analysis method as Kodera and Kuroda (2000) is adopted; an EOF analysis is done for the temperature field averaged in the polar region with multiple levels from the surface to the lower mesosphere, after applying a low-pass filter of 15 days for the deviation from the climatological seasonal march. Contributions of EOF1 and EOF2 are 73.8% and 20.5%, respectively. PJOs are identified in a normalized PC1-PC2 phase space, and their statistics are obtained to identify the seasonal dependence. AOs are also studied by a similar EOF analysis on the area-weighted zonal mean sea-level pressure in the northern hemisphere. One of the novel aspects of the present study is the statistical significance of the analyzed results based on the long enough dataset. Seasonal dependence of the features of SSW, PJO and AO is clearly obtained. Another is the finding of statistically significant relationship among SSW, PJO and AO. Both SSW and PJO events are observed in over 8,000 years out of 14,000 years, and the relationship between SSW and PJO is classified into three groups; (1) an SSW event over 10 days before the maximum of PJO, (2) nearly the same timing of SSW and PJO, and (3) PJO without any precursor of SSW. Downward propagation of signals with time is largely different between the groups. Significant increase of the AO index is also obtained before the occurrence date of SSW events. References: Kodera, K. and Y. Kuroda, 2000: Stratospheric and tropospheric aspects of the Arctic Oscillation. Geophys.Res.Lett., 27, 3349-3352. Naito, Y., M. Taguchi and S. Yoden, 2003: A parameter sweep experiment on the effects of the equatorial QBO on stratospheric sudden warming events. J.Atmos.Sci, 60-11, 1380-1394. Nishizawa, S. and S. Yoden, 2005: Distribution functions of a spurious trend in a finite length data set with natural variability: Statistical considerations and a numerical experiment with a global circulation model. J.Geophys.Res., 110, D12105, doi:10.1029/2004JD005714

  19. Relative importance of the AO, NAO and Aleutian Low in predicting regional climate change

    NASA Astrophysics Data System (ADS)

    Paeth, H.; Rauthe, M.; Hense, A.

    2003-04-01

    In recent years, several observational and climate model studies have drawn a picture of Northern Hemisphere circulation modes which are largely sensitive to the greenhouse forcing with implications for regional climate change. The dominant candidates are the Arctic Oscillation (AO), the North Atlantic Oscillation (NAO) and the Aleutian Low (AL). Here, we consider all these modes equally and try to get insight into their relative importance with respect to temperature and rainfall variability over the Northern Hemisphere. The relative importance of AO, NAO and AL time series is determined by stepwise multiple regression with cross validation at every grid point of the globe. This tool is appropriate to sort the predictors - AO, NAO and AL - by their relative contribution to temperature and rainfall predictability and to evaluate the predictability with respect to an independent control data set. This allows to cut off the number of predictors as soon as the mean square error between the multiple regression model and the control data set is increasing. For better reliability of our results, the procedure is applied many times with 100 permutations. This part is based on the NCEP reanalysis data set. For estimating future temperature and rainfall anomalies, a broad model intercomparison study has been carried out, including most state-of-the-art models of the international modeler community. For each circulation mode superensemble-mean time series under greenhouse-gas (GHG) only and GHG plus sulphate aerosol conditions are determined respectively. Concerning annual-mean temperature, the total explained variance by an optimal number of predictors amounts to 60% over northern Europe, Siberia and North America. At most grid points of the Northern Hemisphere, the AO is the most prominent mode, also in the European-Atlantic sector where the NAO is supposed to be the main player. In the North Pacific sector and in some regions of the low latitudes the AL is dominating. The NAO mainly occupies rank 2 in the surroundings of the North Atlantic, the AO holds the same rank in the North Pacific region. This picture is largely independent of the 100 permutations. In terms of the year-to-year precipitation changes, the impact of the circulation modes is less striking, probably due to the high amount of internal variability. However, large-scale anomalies over northern Europe and the western Mediterranean, induced by the AO, as well as the western United States, induced by the AL, are statistically significant. Inserting the superensemble-mean index values, representative of the late 21st century, in the regression equation with optimal numbers of predictors leads to an estimate of future circulation-induced temperature and rainfall anomalies. This contribution is found to be considerable, amounting to around 25% of the total expected mean change as depicted in the IPCC 2001 report.

  20. 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 possible loss of data quality. For example, a reduction in filtering can introduce noise into the signal and using analog channels could result in some loss of accuracy. Data quality assessments need to be performed concurrently with timesaving techniques since data quality parameters are essential in maintaining facility integrity. This paper will highlight time saving efforts being undertaken or studied at the NTF. It will outline the instrumentation and computer systems involved in setting of the model pitch attitude then suggest changes to the process and discuss how these system changes would effect the time between data points. It also discusses the issue of data quality and how the potential efficiency changes in the system could affect it. Lastly, it will discuss the possibility of using an open loop control system and give some pros and cons of this method.

  1. Development and validation of the AO pediatric comprehensive classification of long bone fractures by the Pediatric Expert Group of the AO Foundation in collaboration with AO Clinical Investigation and Documentation and the International Association for Pediatric Traumatology.

    PubMed

    Slongo, Theddy; Audigé, Laurent; Schlickewei, Wolfgang; Clavert, Jean-Michel; Hunter, James

    2006-01-01

    A series of four agreement studies (classification sessions) were conducted to support the development and validation of a comprehensive pediatric long bone fracture classification system. This system follows the principle of the Müller-AO classification for long bones in adults and integrates most relevant existing pediatric classification systems. The diagnosis includes the distinction between epiphyseal (E), metaphyseal (M), or diaphyseal (D) fractures, as well as identification of child-specific features. This article describes the proposed system in some detail. Digital standard preoperative anteroposterior and lateral radiographs from 267 consecutive pediatric patients (<16 years old and open physis) with single fractures of the distal humerus, radius, or tibia were collected at a single university children's hospital. Fractures were classified independently by five experienced pediatric surgeons. The classification process was assessed for reliability using the kappa coefficient and accuracy using latent class modeling separately for each bone for bone type, and separately for each bone type for child codes. At the last classification session, kappa values for E-M-D and child code classifications were mostly above 0.90, and accuracy estimates were between 75% and 100% for different surgeons, types, and bones. Disagreement and misclassification of fractures were overall very low; hence, experienced and trained surgeons can classify pediatric long bone fractures using the proposed system with high accuracy based on standard radiographic views. The authors encourage wide consultation and further evaluation of this proposed pediatric long bone classification system with a larger number of future users with different training before being used for documentation and clinical studies. PMID:16439900

  2. Closed-loop tomographic control on HOMER wide-field AO bench: experimental results and identification issues

    NASA Astrophysics Data System (ADS)

    Parisot, Amelie; Costille, Anne; Petit, Cyril; Fusco, Thierry

    2010-07-01

    Adaptive Optics (AO) has a limited corrected field of view because of the anisoplanatism effect. Wide Field AO (WFAO) concepts, such as Multi-Conjugate AO (MCAO), have been developed to overcome this limitation. These complex WFAO systems raise critical challenges such as tomographic control and calibrations. We present new results obtained in closed-loop configuration with the laboratory bench HOMER which is devoted to implementation and validation of these WFAO concepts in the perspective of future VLT/ELT AO systems. Turbulence is generated with rotating phase screens and multi-directional analysis is performed. Tomographic control relies on Linear Quadratic Gaussian control (LQG). The correction can be applied thanks to two Deformable Mirrors (DM). We also focus on calibration issues and models identification. We investigate in particular identification of relative geometry of the wave front sensors, DM altitude and asterism and its impact on performance.

  3. High-contrast imaging with ELTs: effects of cophasing and AO residual errors on the PSF contrast

    NASA Astrophysics Data System (ADS)

    Lardiere, Olivier; Carbillet, Marcel; Riccardi, Armando; Salinari, Piero

    2004-10-01

    Direct detection and characterization of terrestrial extrasolar planets are now a high-priority scientific program where new major results from extremely large telescopes (ELTs) are expected. This application is also the most demanding for the adaptive optics (AO) and the mirror segment cophasing. To optimize the fundamental performances of an ELT in high-contrast imaging, we compare the effects of segment cophasing errors with the effects of each AO residual phase errors (wavefront sensor noise, fitting, aliasing, servo-lag) on the long-exposure point-spread function halo. We emphasize that an adaptive correction of the differential segment piston at a nanometric level is needed to keep the contrast gain provided by a high-order AO. We show the potential advantages of an adaptive primary mirror for this purpose. Lastly, we present the planet detection performances in the photon-noise-limited case for different telescopes, AO parameters, and observational conditions (star magnitudes and sites).

  4. Effects of The NAO/ao Fluctuations Upon Precipitation Over Sardinia In The 20th Century.

    NASA Astrophysics Data System (ADS)

    Delitala, A.

    The effects at regional scale of decadal fluctuation of the NAO/AO on the 20th cen- tury precipitation over Sardinia will be analyzed. Decadal variations of precipitation will initially be described, by use of the Standardized Anomaly Index (Katz &Glantz, 1986) based on two indicators: the cumulated precipitation (the classical approach) and the number of rainy days. A clear decreasing trend in the last two deacdes, statis- tically significant at the 1% level, will be highlighted. A short survey of connections with MSLP and 500hPA Geopotential Height fields will be used to give an overview of dependence of Sardinia (regional) precipitation on synoptic-scale and planetary scale features. In the following part, three different paradigms of the NAO/AO will be used: the classical two point obscillation, the PCA analysis of MSLP (Thompson &Wallace, 1998) and the centers of action approach (Machel et al., 1998). The results of the anal- ysis of the effects of NAO/AO (described in the former three ways) on precipitation will enable to discuss how such a teleconnection influences regional precipitation on this part of the Mediterranean. Statistical significance of each result will be provided during the presentation. Katz, R., Glantz, M., 1986. "Anatomy of a Rainfall Index". Mon. Wea. Rev., 114, 764-771. Mächel, M., Kapala, A., Flohn, H., 1998. "Behaviour of the Centers of Action above the Atlantic since 1881. Part I: Characteristics of seasonal and interannual Variability". Int. Jou. of Climatol., 18, 1-22. Thopson, D. W. J., Wallace, J. M., 1998. "The Arctic Oscillation signature in the wintertime geopotential height and temperature fields". Geoph. Res. Let., 25, 1297- 1300.

  5. Harmonic QPOs and Thick Accretion Disk Oscillations in the BL Lacertae Object AO 0235+164

    NASA Astrophysics Data System (ADS)

    Liu, F. K.; Zhao, G.; Wu, Xue-Bing

    2006-10-01

    Periodic outbursts are observed in many active galactic nuclei (AGNs) and are usually explained with a supermassive black hole binary (SMBHB) scenario. However, multiple periods are observed in some AGNs and cannot be explained in this way. Here we analyze the periodicity of the radio light curves of AO 0235+164 at multiple frequencies and report the discovery of six quasi-periodic oscillations (QPOs) in the integer frequency ratio 1:2:3:4:5:6, of which the second, with period P2=5.46+/-0.47 yr, is the strongest. We fit the radio light curves and show that the initial phases of the six QPOs have differences of 0 or π relative to each other. We suggest a harmonic relationship among the QPOs. The centroid frequency, relative strength, harmonic relationship, and relative initial phases of the QPOs are independent of radio frequency. The harmonic QPOs are likely due to quasi-periodic injection of plasma from an oscillating accretion disk into the jet. We estimate a supermassive black hole mass of MBH~=(4.72+/-2.04)×108 Msolar and an accretion rate m˙~=0.007. With knowledge of the accretion disk, this implies that the inner region of the AO 0235+164 accretion disk is a radiatively inefficient accretion flow. The oscillatory accretion is due to p-mode oscillations of the thick disk, probably excited by a SMBHB. Theoretical predictions for the fundamental oscillation frequency and the harmonics show good consistency with the observations. Harmonic QPOs would disappear if the thick disk became geometrically thin as the result of an increase in accretion rate. We discuss the observations of AO 0235+164 in the context of the SMBHB-thick disk oscillation scenario.

  6. 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.

  7. 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.

  8. 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).

  9. 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.

  10. LDEF (Postflight), AO180 : The Effect of Space Environment Exposure on the Properties of Polymer Mat

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO180 : The Effect of Space Environment Exposure on the Properties of Polymer Matrix Composite Materials, Tray D12 The postflight photograph was taken in the SAEF-II facility prior to removal of experiment trays from the LDEF. The Polymer Matrix Composite Materials experiment appears the same as in the flight photograph. The composite containing the aramid (Kevlar) fibers has changed from a yellow to a light brown color and the cylinderical tubes containing the boron and carbon fiber materials have changed from a light green tint to a brown color. The experiment mounting hardware and fasteners seem to be intact and in very good condition.

  11. 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).

  12. 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.

  13. Optical calibration of capacitive sensors for AO: strategy and preliminary results

    NASA Astrophysics Data System (ADS)

    Briguglio, Runa; Xompero, Marco; Riccardi, Armando; Biasi, Roberto; Andrighettoni, Mario

    2012-07-01

    LBT contactless, voice-coil actuators working point ranges from 10 to 100 μm, with a typical position noise of a few nm. To fully take advantage of such large working range in AO operations, an absolute calibration of their capacitive sensor is requested. We implemented and tested an optical calibration technique that is based on a fast interferometer detection of a differential piston superimposed to a low order mirror mode. This procedure has been tested in dome environment at the Large Binocular Telescope.

  14. 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.

  15. The COWL pattern identified with a large AO index and its impact on annular surface temperature anomalies

    NASA Astrophysics Data System (ADS)

    Shi, Ning; Bueh, Cholaw

    2012-08-01

    In this study, the cold ocean/warm land (COWL) pattern was identified from the leading empirical orthogonal function (EOF) of the monthly 1000-hPa geopotential height field poleward of 20°N. Traditionally, the leading EOF has been recognized as the Arctic Oscillation (AO), or Northern Annular Mode (NAM), which causes annular surface air temperature (SAT) anomalies over high-latitude regions of the Northern Hemisphere. A new finding of the present study is that the total AO events defined by the large AO index actually include a distinct type of events that are characterized by a less-annular spatial structure, i.e., the COWL pattern, which shows an NAO-like distribution in the Atlantic sector and a center of action over the North Pacific with the same sign as that over the Arctic. In addition, unlike canonical AO events, the COWL events also show a less-annular pattern in the stratosphere. Statistically, at least one-third of the AO events can be categorized as the COWL events. The SAT anomalies associated with the COWL pattern have an annular distribution over the high-latitude region of the two continents in the Northern Hemisphere. In contrast, if the COWL events are removed from the total AO events, the remainder shows less annular SAT anomalies. Thus, the typical annular SAT anomalies associated with AO events are in large part due to the contribution of the COWL pattern. Furthermore, the monthly variability and the interannual variability of all the AO events are equally important.

  16. The Influence of Dominant Global Climate Phenomena ENSO, NAO, and AO on Climate in Serbia

    NASA Astrophysics Data System (ADS)

    Jovanovic, G.; Reljin, I.; Reljin, B.

    2010-09-01

    The relationship between El Niňo and temperatures in Serbia has been proved. Certain correlation among the average monthly temperatures in Serbia and in Niňo 3,4 region, with three months delay, has been found. The fractal analysis of these temperature series was performed via R/S statistic indicating fractal and multifractal (MF) nature of processes. The calculation of cross-correlation coefficients between NAO index and precipitation, temperature, and pressure data in Serbia has proved considerable NAO influence on Serbia region, especially during winter. The following correlation values were obtained between NAO Index and: pressure 0.60, temperature 0,64, both for Belgrade, while for Niksic negative cross-correlation was obtained for precipitation -0,53. The fractal and multifractal analyses of pressure data series on a number of stations in a wide region from Azores to Iceland and Serbia were done. The obtained results showed that each station in the region has characteristic multifractal spectra of pressure data. The teleconnection with NAO has been also proved by the comparisons of EOF analysis of pressure field in Serbia with the EOF for the north Atlantic domain. The analyses of NAO influence based on daily precipitation data on stations in Serbia and NAO daily index plus AO daily index were prepared, too. These results suggest that AO influence in Serbia is more prominent than the one obtained for NAO.

  17. 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.

  18. OCam with CCD220, the Fastest and Most Sensitive Camera to Date for AO Wavefront Sensing

    NASA Astrophysics Data System (ADS)

    Feautrier, Philippe; Gach, Jean-Luc; Balard, Philippe; Guillaume, Christian; Downing, Mark; Hubin, Norbert; Stadler, Eric; Magnard, Yves; Skegg, Michael; Robbins, Mark; Denney, Sandy; Suske, Wolfgang; Jorden, Paul; Wheeler, Patrick; Pool, Peter; Bell, Ray; Burt, David; Davies, Ian; Reyes, Javier; Meyer, Manfred; Baade, Dietrich; Kasper, Markus; Arsenault, Robin; Fusco, Thierry; Diaz Garcia, José Javier

    2011-03-01

    For the first time, subelectron readout noise has been achieved with a camera dedicated to astronomical wavefront-sensing applications. The OCam system demonstrated this performance at a 1300 Hz frame rate and with 240 × 240 pixel frame size. ESO and JRA2 OPTICON jointly funded e2v Technologies to develop a custom CCD for adaptive optics (AO) wavefront-sensing applications. The device, called CCD220, is a compact Peltier-cooled 240 × 240 pixel frame-transfer eight-output back-illuminated sensor using the EMCCD technology. This article demonstrates, for the first time, subelectron readout noise at frame rates from 25 Hz to 1300 Hz and dark current lower than 0.01 e- pixel-1 frame-1. It reports on the quantitative performance characterization of OCam and the CCD220, including readout noise, dark current, multiplication gain, quantum efficiency, and charge transfer efficiency. OCam includes a low-noise preamplifier stage, a digital board to generate the clocks, and a microcontroller. The data acquisition system includes a user-friendly timer file editor to generate any type of clocking scheme. A second version of OCam, called OCam2, has been designed to offer enhanced performance, a completely sealed camera package, and an additional Peltier stage to facilitate operation on a telescope or environmentally challenging applications. New features of OCam2 are presented in this article. This instrumental development will strongly impact the performance of the most advanced AO systems to come.

  19. 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.

  20. Using the vector vortex coronagraph in the ExAO regime at Palomar: lessons learned

    NASA Astrophysics Data System (ADS)

    Mawet, D.; Serabyn, E.; Burruss, R.

    2010-10-01

    We have been using the vector vortex coronagraph intensively on sky behind the 1.5-meter well-corrected subaperture on the 5-m Hale telescope at the Palomar observatory. This configuration allowed us to experiment the use of this small inner working angle, high throughput, clear and symmetric off-axis discovery space coronagraph in the ExAO regime. We will discuss the system level issues we had to tackle to make the most of this instrumental setup: low-frequency and high frequency pointing stabilization, focus removal, non-common path wavefront errors calibrations using the modified Gerchberg-Saxton phase retrieval technique, synchronized observing strategy. Without the availability of differential imaging capabilities such as angular or spectral differential imaging, we had to rely on the well-proven reference star subtraction. While not ideal, this method will be the only way to get to close separations since both ADI and SDI fail at very small angles. Fast and reproducible AO target acquisition allowed us to implement an efficient target-reference nodding method which is the key to achieving a high degree of correlation in the quasi-static speckle pattern required by smart data processing methods such as the locally optimized combination of images (LOCI).

  1. 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.

  2. Risk factors associated with Campylobacter jejuni infections in Curaçao, Netherlands Antilles.

    PubMed

    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

    2003-12-01

    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

  3. 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.

  4. 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-?-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. PMID:26241131

  5. Volcanic Activity of Io Monitored with Keck-10m AO in 2003-2004

    NASA Astrophysics Data System (ADS)

    Marchis, F.; Davies, A. G.; Gibbard, S. G.; Le Mignant, D.; Lopes, R. M.; Macintosh, B.; de Pater, I.

    2004-12-01

    With the demise of the Galileo mission, the monitoring of Io volcanic activity lies in the hands of ground-based observers. Our group regularly observed Io with the Keck-10m Adaptive Optics (AO) system and its NIRC-2 camera at 1-5 microns wavelength range. The angular resolution achieved is 0.05" in Kc band (2.2 microns), i.e. 120-140 km on Io at opposition. Approximately 5 to 8 active volcanic centers are usually detected on one 3 or 5 microns AO image with a T between 500 and 1000 K. On rare occasions, we detected the thermal output at shorter wavelength (1-2.5 micron) indicating a colour temperature >1300 K. For instance, our data revealed the presence on Jan. 26, 2003, of a bright eruption close to Janus Patera (53S, 393W) with intensity in Lp band (3.8 micron) of 111 GW/sr/micron and 2 GW/sr/micron in Kc band (2.2 micron). Another bright eruption close to Tupan Patera (164S, 1374W) was seen on Mar. 8, 2003 (UT) with a I(Lp)=18 1 GW/sr/micron and I(Kc) 3 GW/sr/micron. More recently, data taken on May 28 and 30, 2004, show the thermal emission of an eruptive center (called 0405A) located at 172 S, 61W (close to Ilmarinera Patera which has never been seen active) with a I(Kc) 7 GW/sr/micron and I(Lp)=1666 GW/sr/micron. This energetic eruption was also detected in H band (1.6 micron) with I(H) 3 GW/sr/micron. Because we obtained the brightness of these eruptions in at least three different wavelengths, we can perform a more precise analysis of their activity using a basaltic cooling lava flow model (Davies, 1996). In the case of 0405A, we can conclude that we are observing an episode of fire-fountaining (a young, hot event) whose total output is estimated to 9E12 W (i.e. 10% of Io average total output), more energetic than Tvashtar 2001. The source of these active centers and their activity will be compared with previous Galileo NIMS/SSI observations. We will conclude describing how the future use of AO technique will help to monitor and understand this extraterrestrial and exotic volcanism.

  6. 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.

  7. Aspergillus oryzae AoSO is a novel component of stress granules upon heat stress in filamentous fungi.

    PubMed

    Huang, Hsiang-Ting; Maruyama, Jun-ichi; Kitamoto, Katsuhiko

    2013-01-01

    Stress granules are a type of cytoplasmic messenger ribonucleoprotein (mRNP) granule formed in response to the inhibition of translation initiation, which typically occurs when cells are exposed to stress. Stress granules are conserved in eukaryotes; however, in filamentous fungi, including Aspergillus oryzae, stress granules have not yet been defined. For this reason, here we investigated the formation and localization of stress granules in A. oryzae cells exposed to various stresses using an EGFP fusion protein of AoPab1, a homolog of Saccharomyces cerevisiae Pab1p, as a stress granule marker. Localization analysis showed that AoPab1 was evenly distributed throughout the cytoplasm under normal growth conditions, and accumulated as cytoplasmic foci mainly at the hyphal tip in response to stress. AoSO, a homolog of Neurospora crassa SO, which is necessary for hyphal fusion, colocalized with stress granules in cells exposed to heat stress. The formation of cytoplasmic foci of AoSO was blocked by treatment with cycloheximide, a known inhibitor of stress granule formation. Deletion of the Aoso gene had effects on the formation and localization of stress granules in response to heat stress. Our results suggest that AoSO is a novel component of stress granules specific to filamentous fungi. The authors would specially like to thank Hiroyuki Nakano and Kei Saeki for generously providing experimental and insightful opinions. PMID:23991062

  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. LDEF (Flight), AO180 : The Effect of Space Environment Exposure on the Properties of Polymer Matrix

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO180 : The Effect of Space Environment Exposure on the Properties of Polymer Matrix Composite Materials, Tray D12 The flight photograph was taken from the Orbiter aft flight deck during the LDEF retrieval. During the mission, the tray surface was at an angle of approximately ninety-eight (98) degrees to the orbital velocity vector and therefore exposed to a lower atomic oxygen flux than if parallel with the velocity vector. A very light stain is present on white paint dots on experiment tray clamps along the lower edge of the tray. The Polymer Matrix Composite Materials experiment has several changes to material colors. The composite containing the aramid (Kevlar) fibers has changed from a yellow to a light brown color and the cylindrical tubes containing the boron and carbon fiber materials have changed from a light green tint to a brown color.

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

    NASA Astrophysics Data System (ADS)

    Taylor, Gregory Edward

    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.

  11. 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. PMID:25256296

  12. Sub-rubble communities of Curaçao and Bonaire coral reefs

    NASA Astrophysics Data System (ADS)

    Meesters, E.; Knijn, R.; Willemsen, P.; Pennartz, R.; Roebers, G.; van Soest, R. W. M.

    1991-12-01

    The distribution and abundance of sessile organisms under coral rubble has been studied at Bonaire and Curaçao, Netherlands Antilles. Species richness under rubble is extremely high with at least 367 species of which sponges, tunicates and bryozoans are the most important. Shallow sub-rubble communities can be considered refuges as the majority of these species are crypt-obligate. Sub-rubble communities may also have a preserve function for sponges, but do not harbour enough corals to ensure a quick coral recolonization of the reef surface after a major disaster. Cryptic community composition is affected by depth and pollution, and differs substantially between the two neighbouring islands, possibly as a result of different bottom characteristics. Biomass of the sub-rubble communities may contribute considerably to total reef biomass. Diversity varies inversely with increased depth and increased rubble size, possibly indicating abiotic control (e.g. physical disturbance by wave action and reef slope substrate collapse).

  13. The variability and periods in the BL Lac AO 0235+164

    NASA Astrophysics Data System (ADS)

    Fan, J. H.; Kurtanidze, O.; Liu, X.; Liu, Y.; Wang, H. T.; Yuan, Y. H.; Hao, J. M.; Wu, D. X.; Cai, W.; Xiao, H. B.; Pei, Z. Y.

    2015-03-01

    Variability is one of the extreme observational properties of BL Lacertae objects. AO 0235+164 is a well studied BL Lac through the whole electro-magnetic wavebands, it is violently variable in the optical bands. In the present work, we show its optical R band photometric observations carried out during the period of Nov. 2006 to Dec. 2012 using the Ap6E CCD camera attached to the primary focus of the 70 cm meniscus telescope at Abastumani Observatory, Georgia. It shows a large variation of ?R = 4.88 mag (14.20 - 19.08 mag) during our monitoring period. When periodicity analysis methods are adopted to its R observations from our Abastumani monitoring programme and those in the literature, the signs of some periods, P 1 = 8.26 yr, P 2 = 0.55 yr, P 3 = 0.85 yr, P 4 = 1.99 yr are found.

  14. LDEF (Postflight), AO187-02 : Chemical and Isotropic Measurements of Micrometeoroids by Secondary Io

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO187-02 : Chemical and Isotropic Measurements of Micrometeoroids by Secondary Ion Mass Spectrometry, Tray E08 This postflight photograph shows an experiment that has been severely degraded due to orbital exposure on the leading edge of the LDEF. The metallic coated thin Mylar film has been lost on each of the capture cells. As the thin Mylar film failed, the material curled tightly into small conical shapes and can be seen still attached to the aluminum mounting structure edges of many capture cells. Close examination of capture cells near the tray center clearly show the four individual high purity germanium plates with some of the bonding material exposed between plates. The green tint on the germanium plate at the right edge of the experiment tray is a reflection from the lights in the high bay area of SAEF II at KFC. Dim reflections from various sources can be seen on other sections of the experiment.

  15. 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.

  16. 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.

  17. User perceptions on coastal resource state and management options in Curaçao.

    PubMed

    Debrot, A O; Nagelkerken, I

    2000-12-01

    Public environmental awareness and support for management measures are key determinants of the scope for successful implementation of natural resource management. To assess user perceptions and opinions on resource state and potential management options for the coastal zone of Curaçao, we queried 250 coastal resource users from around the island (sport divers, part-time artisanal fishermen and recreational boaters) using questionnaires. There is wide awareness of a long-term decline in coastal resource condition as measured by various indicators. Even among fishermen there was wide awareness of anthropogenic contributors to the decline, broad agreement of management measures required and a general willingness to contribute to management by means of annual license fees. Some of the more salient findings include the endorsement by fishermen of the current ban on spearfishing (81%), the regulation of the beach seine fishery for scad (77%), the introduction of fish reserves (72%), special protection for sea turtles (90%), conch (82%), and lobsters (72%), and notable support for gradual elimination of trap fisheries (45%). Also, both divers (65%) and boaters (92%) expressed the importance to them of an attractive coastline, with both groups expressing preference for natural (un-built) coastline (>74%) above other categories. Management based on the concept "user pays", as already implemented in the Netherlands Antilles on Saba and Bonaire, is well supported by the resource user public. A review of other main constraints such as finances and institutional capacity, shows that conditions are quite favorable for implementation of new legislation. Modem coral reef management is urgently needed in Curaçao to safeguard a key natural resource and concerted action is called for on the part of government agencies, legislators and elected officials. PMID:15266797

  18. 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.

  19. Subaru Strategic Exploration of Exoplanets and Disks with HiCIAO/AO188 (SEEDS)

    NASA Astrophysics Data System (ADS)

    Tamura, Motohide

    2009-08-01

    Since the first detection of exoplanets orbiting normal stars in 1995, many exciting discoveries have been made, but our understanding of planetary systems and their formation is far from complete. A census of companions to stars over a wide range of ages will provide important clues to the formation and evolution of stars, brown dwarfs, and planets. Armed with a much better performance than that of the previous coronagraphic imager with adaptive optics (CIAO and AO36 combination), we will conduct a Subaru+High-Contrast Coronographic Imager for Adaptive Optics (HiCIAO)+AO188 imaging survey, searching for giant planets (1 Mj

  20. 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.

  1. 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.

  2. Comparative analysis of the main bioactive components of San-ao decoction and its series of formulations.

    PubMed

    Shu, Xiaoyun; Tang, Yuping; Jiang, Chenxue; Shang, Erxing; Fan, Xinshen; Ding, Anwei

    2012-01-01

    A high performance liquid chromatographic (HPLC) method with diode array detection (DAD) was established for simultaneous determination of seven main bioactive components in San-ao decoction and its series of formulae (San-ao decoction, Wu-ao decoction, Qi-ao decoction and Jia-wei San-ao decoction). Seven compounds were analyzed simultaneously with a XTerra C(18) column (4.6 mm × 250 mm, 5 µm) using a linear gradient elution of a mobile phase containing acetonitrile (A) and a buffer solution (0.02 mol/L potassium dihydrogen phosphate and adjusted to pH 3 using phosphoric acid) (B); the flow rate was 1.0 mL/min. The sample was detected with DAD at 210, 254 and 360 nm and the column was maintained at 30 °C. All the compounds showed good linearity (r2 > 0.9984) in the tested concentration range. The precisions were evaluated by intra-day and inter-day tests, and relative standard deviation (R.S.D.) values within the range of 0.83%–2.53% and 0.64%–2.77% were reported, respectively. The recoveries of the quantified compounds were observed to cover a range from 95.34% and 104.82% with R.S.D. values less than 2.72%. The validated method was successfully applied for the simultaneous determination of seven main bioactive components including ephedrine (1), amygdalin (2), liquiritin (3), benzoic acid (4), isoliquiritin (5), formononetin (6) and glycyrrhizic acid (7) in San-ao decoction and its series of formulae. The results also showed a wide variation in the content of the identified active compounds in these samples, which could also be helpful to illustrate the drug interactions after some herbs combined in different formulations. PMID:23117432

  3. 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 shear specimen. All specimen, including the tape holding down the small specimen in the lower right corner, have darkened significantly during the extended time in space. Plate VI, in the lower left corner, is populated with solar cells and associated components such as covers, encapsulants,adhesives, etc. The solar cell components appear to be intact with no apparent physical damage.The colors of the specimen, however, appear to have darkened. The photographic lighting angle has significantly highlighted abrasions on the mounting plate surface.

  4. 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 specimens, including the tape holding down the small specimen in the lower right corner, have darkened significantly during the extended time in space. Plate VI, in the lower right corner, is populated with solar cells and associated components such as covers, encapsulants,adhesives, etc.. The solar cell components appear to be intact with no apparent physical damage.The colors of the specimen, however, appear to have darkened.

  5. The Early Cretaceous evolution of SE China: Insights from the Changle-Nan'ao Metamorphic Belt

    NASA Astrophysics Data System (ADS)

    Li, Ye; Ma, Chang-Qian; Xing, Guang-Fu; Zhou, Han-Wen

    2015-08-01

    The Mesozoic geology in SE China is characterized by widespread Jurassic-Cretaceous magmatism. There appears, however, an episode of "magmatic quiescence" at ca. 130-110 Ma in terms of increasing high-precision isotopic age data. The causes and regional tectonic significance of this magmatic quiescence are unclear. In this paper, we report integrated in situ U-Pb, Hf and O isotope analyses of zircons from four mica schist samples along Changle-Nan'ao Metamorphic Belt in SE China coast, and use these data to discuss the provenances of these metasedimentary rocks, the timing of the regional metamorphism and their implications for the regional tectonic evolution. The majority of zircons from the mica schists are euhedral to anhedral crystals showing clear concentric zoning under cathodoluminescence (CL) images. Metamorphic zircon rims with bright luminescence are overgrown on the some of the euhedral to anhedral zoned zircons. The zoned zircons from all mica schist samples are homogeneous in U-Pb age zircon ages (between 131 and 148 Ma, peaking at 141 Ma), O isotopes (δ18O = 5.6 ± 0.8‰, 2SD, n = 106), and, to the less extent, Hf isotopes (εHf(T) = - 4.7 to - 1.4 for the Dongshan mica schists, and - 1.4 to 2.2 for the Putian mica schists). They are most likely detrital zircons sourced from the regional Early Cretaceous felsic volcanic rocks (the Nanyuan Formation) and/or coeval intrusions in Fujian Province. The sedimentary protoliths of these mica schists were likely deposited in fore-arc basins. The metamorphic zircon overgrowths have relatively low Th/U ratios; they are dated at ~ 130-100 Ma, with two peaks at ~ 125 Ma and ~ 108 Ma. The first metamorphic age of ~ 125 Ma is coincident with the timing of regional Early Cretaceous magmatic quiescence, while the second metamorphic age of ~ 108 Ma is consistent with the timing of reinitiation of regional Cretaceous magmatism. We use a model of collision between the West Philippines and SE China blocks to interpret our new results. According to this model, the intensive Early Cretaceous (ca. 140-130 Ma) magmatism along the coastal region of SE China was attributed to the subduction of the Paleo-Pacific plate beneath SE China. Collision between the West Philippines and SE China blocks at ~ 130-120 Ma resulted in the regional "magmatic quiescence" and formation of the Changle-Nan'ao Metamorphic Belt. Post-collisional extension triggered the reinitiation of magmatism associated with amphibolite-facies metamorphism at ~ 110 Ma.

  6. 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.

  7. Effect of misalignment of air-coupled probes on Ao Lamb mode propagating in a metal plate.

    PubMed

    Ramadas, C; Hood, Avinash; Khan, Irfan; Balasubramaniam, Krishnan

    2014-07-01

    Proper alignment of air-coupled ultrasonic transducers for generation and reception of Lamb waves is vital in order to acquire a high amplitude wave group. Any misalignment with either the transmitter or the receiver or both adversely influences the amplitude of a Lamb mode. This paper reports a systematic attempt to quantify the reduction in the amplitude of the fundamental anti-symmetric Lamb mode (Ao) in a metal plate caused by misalignments in air-coupled probes. Three different types of misalignments - linear, orientation and synchronised orientation were deliberately introduced in the transducers, and experiments were performed on a 6mm thick aluminium plate. Amplitudes of Ao mode measured at various configurations were normalised with that of Ao mode, captured in a reference configuration. Suitable curves fitted over the experimental data points revealed that Gaussian curves represent appropriately the variations in normalised amplitudes of Ao mode. Moreover, analytical expressions were derived to predict the difference in arrival times of Lamb mode(s) due to orientation and synchronised orientation misalignments. PMID:24630155

  8. Tighter multipole-based integral estimates and parallel implementation of linear-scaling AO-MP2 theory.

    PubMed

    Doser, Bernd; Lambrecht, Daniel S; Ochsenfeld, Christian

    2008-06-21

    Within an atomic-orbital-based (AO-based) formulation of second-order Møller-Plesset perturbation theory (MP2), we present a novel screening procedure which allows us to preselect numerically significant two-electron integrals more efficiently, especially for large basis sets. The screening is based on our recently introduced multipole-based integral estimates (MBIE) method [J. Chem. Phys., 2005, 123, 184102], that allows to exploit the 1/R(4) or 1/R(6) coupling between electronic charge distributions in transformed integral products within AO-MP2. In this way, linear scaling is attained with fully-controlled numerical accuracy. Furthermore, a parallel implementation of our linear-scaling AO-MP2 method is described, which also allows us to perform calculations with larger basis sets. First calculations reveal that for e.g. linear alkanes the scaling of the number of required transformed integral products is almost equal for 6-31G* and cc-pVTZ basis sets. Using the improved MBIE screening, the largest parallel calculation was performed for a ribozyme fragment consisting of 497 atoms and 5697 basis functions, while our largest AO-MP2 calculation was performed for a stacked DNA system (16 base pairs) comprising 1052 atoms and 10 674 basis functions on a single processor. PMID:18535715

  9. Na+ Transport by the A1AO-ATP Synthase Purified from Thermococcus onnurineus and Reconstituted into Liposomes*

    PubMed Central

    Mayer, Florian; Lim, Jae Kyu; Langer, Julian D.; Kang, Sung Gyun; Müller, Volker

    2015-01-01

    The ATP synthase of many archaea has the conserved sodium ion binding motif in its rotor subunit, implying that these A1AO-ATP synthases use Na+ as coupling ion. However, this has never been experimentally verified with a purified system. To experimentally address the nature of the coupling ion, we have purified the A1AO-ATP synthase from T. onnurineus. It contains nine subunits that are functionally coupled. The enzyme hydrolyzed ATP, CTP, GTP, UTP, and ITP with nearly identical activities of around 40 units/mg of protein and was active over a wide pH range with maximal activity at pH 7. Noteworthy was the temperature profile. ATP hydrolysis was maximal at 80 °C and still retained an activity of 2.5 units/mg of protein at 45 °C. The high activity of the enzyme at 45 °C opened, for the first time, a way to directly measure ion transport in an A1AO-ATP synthase. Therefore, the enzyme was reconstituted into liposomes generated from Escherichia coli lipids. These proteoliposomes were still active at 45 °C and coupled ATP hydrolysis to primary and electrogenic Na+ transport. This is the first proof of Na+ transport by an A1AO-ATP synthase and these findings are discussed in light of the distribution of the sodium ion binding motif in archaea and the role of Na+ in the bioenergetics of archaea. PMID:25593316

  10. 76 FR 52972 - United States v. Regal Beloit Corp. and A.O. Smith Corp.; Proposed Final Judgment and Competitive...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-24

    ... the market for draft inducers used in furnaces having a thermal efficiency of 90 percent or greater... in the markets for electric motors for pool pumps and electric motors for spa pumps in the United.... Combined, RBC and AOS would supply approximately 85 percent of the U.S. market for electric motors for...

  11. Reproducibility of the AO/ASIF and Gartland classifications for supracondylar fractures of the humerus in children?

    PubMed Central

    Rocha, Igor Tadeu Silveira; Faria, Andr de Siqueira; Filho, Carlos Fontoura; Rocha, Murilo Antnio

    2015-01-01

    Objective To evaluate the reproducibility of the radiographic classifications of Gartland and the Association for Osteosynthesis/Association for the Study of Internal Fixation (AO/ASIF) for supracondylar fractures of the humerus in children. Methods On two occasions, 50 radiographs in anteroposterior and lateral views were evaluated by three pediatric orthopedists in accordance with the Gartland and AO/ASIF pediatric classifications. Their responses were subjected to statistical analysis consisting of calculation of the ? coefficient to assess the intra- and interobserver concordance, in both classifications. Results The strength of the intraobserver concordance was high or near perfect for the three examiners in the two classification systems. The strength of the interobserver concordance was high in the two systems, with ? coefficients of 0.756 for the Gartland classification and 0.766 for the AO/ASIF classification. Conclusion The Gartland and AO/ASIF classification systems showed similar reproducibility and performance. High strength of concordance was seen in the intra- and interobserver analyses. PMID:26229928

  12. 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

  13. Ruled and holographic experiment (AO 138-5). [long duration exposure facility

    NASA Technical Reports Server (NTRS)

    Bonnemason, Francis

    1992-01-01

    The AO 138-5 experiment has been designed, via the French Cooperative Payload (FRECOPA) experiment with the aim to study the optical behavior of different diffraction gratings submitted to space vacuum long exposure and solar radiation. Samples were rules and holographic gratings, masters or replica, and some additional control mirrors with various coatings. The experiment was located on the B3, trailing edge of the Long Duration Exposure Facility (LDEF) and has been protected against atomic oxygen flux. The experienced thermal cycling has been evaluated from -23 C to 66 C during the flight, 34,000 orbits. The analysis has been focused on the triple point characterization including light efficiency, wavefront flatness quality and stray light level. Tests were conducted on control mirrors and gratings loaded but not exposed to cosmic dust or solar irradiations. They did not show any significant variations. Solar exposure has damaged the coating reflectivity in the ultraviolet region, the degradation is higher with the gratings, in terms of efficiency. However, wavefront flatness quality and stray light level tests revealed no additional changes.

  14. Factors contributing to inconsistent condom use among heterosexual men in Curaçao.

    PubMed

    Stutterheim, Sarah E; Bertens, Madelief G B C; Mevissen, Fraukje E F; Schaalma, Herman P

    2013-01-01

    This study explored, from a public health perspective, factors that contribute to inconsistent condom use by men in Curaçao through semi-structured face-to-face interviews with 21 heterosexual men. The findings show that there is an important disconnect between what is considered culturally appropriate sexual behaviour for men and women and condom use, that diverging from prescribed notions of masculinity and femininity in order to use condoms consistently is difficult, and that condom use is particularly problematic in the context of concurrent partnerships and sexual economic exchanges. Participants further reported that Caribbean family structures, whereby mothers assume the role as primary caregiver and fathers contribute biologically but, to a much lesser extent socially, also have an impact on condom use. Additionally, consistent condom use was reported to be impeded by a cultural taboo on talking seriously about sex and sexual health. In their totality, findings provide important input from men for the development of sexual health promotion interventions that are cognizant of the cultural context in which inconsistent condom use occurs, and that are geared not only to the individual level but also to the interpersonal and structural levels. PMID:23350609

  15. LDEF (Prelaunch), AO015 : Free-Flyer Biostack Experiment, Tray G02

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), AO015 : Free-Flyer Biostack Experiment, Tray G02 The prelaunch photograph shows the Bio stack experiment containers mounted on a baseplate and installed in a six (6) inch deep LDEF end corner experiment tray. Non-magnetic stainless steel fasteners were used in all mechanical joint assemblies. The Biostack experiment consist of twenty (20) detector units in hermetically sealed aluminum housings mounted on aluminum baseplates. Eight (8) detector units are mounted on a baseplate and installed in a six (6) inch peripheral tray adjacent to the LDEF trailing edge and twelve (12) detector units mounted on a baseplate are located in the tray shown and will be installed on the earth facing end of the LDEF. The experiment housings and the mounting plate have a thin chro mic anodize surface coating to meet thermal requirements. Two (2) housings have windows cov ered with Kapton H foil that provides a light filter with low radiation absorption. Two (2) additional housings have windows covered with Kapton H foil but also have perforated aluminum domes to limit incoming earth albedo.

  16. The L3Vision CCD220 with its OCam test camera for AO applications in Europe

    NASA Astrophysics Data System (ADS)

    Feautrier, Philippe; Gach, Jean-Luc; Balard, Philippe; Guillaume, Christian; Downing, Mark; Stadler, Eric; Magnard, Yves; Denney, Sandy; Suske, Wolfgang; Jorden, Paul; Wheeler, Patrick; Skegg, Michael; Pool, Peter; Bell, Ray; Burt, David; Reyes, Javier; Meyer, Manfred; Hubin, Norbert; Baade, Dietrich; Kasper, Markus; Arsenault, Robin; Fusco, Thierry; Diaz Garcia, Jose Javier

    2008-07-01

    ESO and JRA2 OPTICON have jointly funded e2v technologies to develop a custom CCD for Adaptive Optic Wave Front Sensor (AO WFS) applications. The device, called CCD220, is a compact Peltier-cooled 240×240 pixel frametransfer 8-output back-illuminated sensor. Using the electron-multiplying technology of L3Vision detectors, the device is designed to achieve sub-electron read noise at frame rates from 25 Hz to 1,500 Hz and dark current lower than 0.01 e-/pixel/frame. The development has many unique features. To obtain high frame rates, multiple EMCCD gain registers and metal buttressing of row clock lines are used. The baseline device is built in standard silicon. In addition, two speculative variants have been built; deep depletion silicon devices to improve red response and devices with an electronic shutter to extend use to Rayleigh and Pulsed Laser Guide Star applications. These are all firsts for L3Vision CCDs. These CCD220 detectors have now been fabricated by e2v technologies. This paper describes the design of the device, technology trade-offs, and progress to date. A Test Camera, called "OCam", has been specially designed and built for these sensors. Main features of the OCam camera are extensively described in this paper, together with first light images obtained with the CCD220.

  17. [The AO external clamp fixator. New techniques in external stabilization of tibial fractures].

    PubMed

    Haas, N P; Schütz, M; Frigg, R; Südkamp, N P; Hoffmann, R

    1994-11-01

    A serious disadvantage of conventional external fixators is the opening of the medullary canal. This creates a direct communication between the canal and the exterior. The new pinless external fixator does not have this disadvantage. The clamps of the new fixator system do not penetrate cortical bone, they simply rest on the cortical surface. The clinical indications of this easily managed system are fractures of the tibial shaft in cases in which primary internal fixation is precluded either by precarious local or general conditions, or even by a lack of infrastructure. In such situations the pinless external fixator is an excellent device to achieve a good fracture stabilisation rapidly, while leaving open all subsequent alteration of treatment. In case of secondary change to an intramedullary nail the pinless fixator facilitates the procedure, because this fixator can be also used as an distractor during nailing. Furthermore this fixator can be combined with any intramedullary nail to increase the stability in case of very proximal or distal as well as highly instable shaft fractures. The clamps of the pinless external fixator set are used in combination with the standard AO fixator system. PMID:7821065

  18. Integration of SAXO, the VLT-SPHERE extreme AO : final performance

    NASA Astrophysics Data System (ADS)

    Fusco, Thierry; Sauvage, Jean-François; Petit, Cyril; Costille, Anne; Dohlen, Kjetil; Beuzit, Jean-Luc; Mouillet, David; Puget, Pascal; Gluck, Laurence; Rochat, Sylvain; Baruffolo, Andrea; Salasnich, Bernardo; Kasper, Markus; Suarez, Marcos; Soenke, Christian; Fedrigo, Enrico; Baudoz, Pierre; Sevin, Arnaud; Perret, Denis; Wildi, François

    2013-12-01

    The direct imaging of exoplanet is an up to date instrumental challenge, as well as a scientific exciting goal. Contrary to indirect methods, the study of exoplanet's own light witnesses for biomarkers presence in their atmosphere. Observing such a faint object close to its bright host star requires dedicated instrumental observation from the ground. SPHERE and GPI are two of these instruments, currently on final AIT phase, for a very first light during this year. Both instruments developed during the last 5 years are composed of extremely high performance AO system (XAO) able to compensate for the optical deformation caused by the turbulence of earth atmosphere. Moreover, the final performance of such a system is limited by the static light residuals present in the imaging focal plane, caused by uncorrected static optical aberrations. The direct imaging of exoplanet therefore also requires to perform self-calibration in order to attenuate these residual and enhance the coronagraphic extinction. This paper presents the final ongoing AIT results of the SPHERE instrument, and mainly focuses on XAO aspects. An exhaustive view of last SAXO performance in lab is shown. In particular, such improvement as the Optimised Modal Gain, optimized Kalman filtering of vibration, and Garbage collection are the key point to reach the final performance. The behavior of the instrument with realistic turbulence strength, wind speed, flux conditions are studied. The self-calibration module, based on phase diversity measurement of NCPA, demonstrates the ultimate performance of the instrument, in term of flux extinction and future scientific results.

  19. First light AO (FLAO) system for LBT: performance analysis and optimization

    NASA Astrophysics Data System (ADS)

    Quirós-Pacheco, Fernando; Busoni, Lorenzo; Agapito, Guido; Esposito, Simone; Pinna, Enrico; Puglisi, Alfio; Riccardi, Armando

    2010-07-01

    We will present in this paper the performance analysis and optimization of the First Light AO (FLAO) system of the Large Binocular Telescope (LBT). The system comprises an adaptive secondary mirror (ASM) with 672 actuators (LBT672a unit) and a pyramid wavefront sensor (PWFS) with adjustable sampling of the telescope pupil from 30×30 down to 4×4 subapertures. The performances have been estimated by means of end-to-end simulations, scanning a range of reference star magnitudes and looking for the optimal set of parameters maximizing the on-axis Strehl Ratio. Specific additional error sources have been accounted for and analyzed separately, such as mis-registration errors, mis-calibration issues, and the effect of telescope vibrations. Taking into account the considered error sources we defined the baseline and goal performances of the FLAO system. The acceptance test of the FLAO system took place in December 2009, demonstrating actual FLAO performances between baseline and goal estimates. The commissioning of the FLAO system to the LBT telescope is currently ongoing until December 2010.

  20. 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

  1. Lycibarbarspermidines A-O, New Dicaffeoylspermidine Derivatives from Wolfberry, with Activities against Alzheimer's Disease and Oxidation.

    PubMed

    Zhou, Zheng-Qun; Fan, Hong-Xia; He, Rong-Rong; Xiao, Jia; Tsoi, Bun; Lan, Kang-Hua; Kurihara, Hiroshi; So, Kwok-Fai; Yao, Xin-Sheng; Gao, Hao

    2016-03-23

    Fifteen new dicaffeoylspermidine derivatives, lycibarbarspermidines A-O (1-15), were isolated from the fruit of Lycium barbarum (wolfberry). The structures were unambiguously determined by spectroscopic analyses and chemical methods. Dicaffeoylspermidine derivatives, a rare kind of plant secondary metabolites, are primarily distributed in the family of Solanaceae. Only six compounds were structurally identified, and all of them are acyclic aglycones. Compounds 1-15 are the first glycosidic products of dicaffeoylspermidine derivatives, and compounds 14-15 are the first cyclization products of dicaffeoylspermidine derivatives. Moreover, dicaffeoylspermidine derivatives were first isolated and identified from wolfberry. The short-term memory assay on a transgenic fly Alzheimer's disease (AD) model showed that 1-15 exhibited different levels of anti-AD activity. The oxygen radical absorbance capacity assay revealed that 1-15 all displayed antioxidant capacity. Both anti-AD and antioxidant functions are related to the effects of wolfberry. Therefore, dicaffeoylspermidine derivatives are considered beneficial constituents responsible for the antiaging, neuroprotective, anti-AD, and antioxidant effects of wolfberry. PMID:26953624

  2. Characterization, expression profile, and promoter analysis of the Rhodeus uyekii vitellogenin Ao1 gene.

    PubMed

    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

  3. 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.

  4. ORBITAL PERIOD CHANGES AND THEIR EVOLUTIONARY STATUS FOR THE WEAK-CONTACT BINARIES. III. AO CAMELOPARDALIS AND AH TAURI

    SciTech Connect

    Yang, Y.-G.; Wei, J.-Y.; Li, H.-L.; Kreiner, J. M. E-mail: sfkreine@cyf-kr.edu.pl

    2010-01-15

    In this paper, we presented multicolor photometric observations for two eclipsing binaries, AO Camelopardalis and AH Tauri, obtained on 2008 December 16 and 17. Using the Wilson-Devinney Code, the photometric solution of AH Tau was determined from our new CCD data. The mass ratio and the fill-out factor are q = 0.503({+-}0.003) and f = 10.8%({+-}0.1%), respectively. This indicates that AH Tau is in weak contact. For the weak-contact binary AO Cam, BVI light curves clearly show a difference in the heights of the maxima (i.e., the O'Connell effect), which may be explained by spot activity. By analyzing the O - C curves for AO Cam and AH Tau, it is found that the orbital periods appear to show a secular period decrease with a cyclic variation. The observed period modulation is {delta}P/P {approx} 10{sup -6}. For AO Cam, the cyclic oscillation with a short period of 7.63({+-}0.07) yr and a low amplitude of 0fd0019({+-}0fd0003) may be preferably attributed to the cyclic magnetic activity. The period and amplitude of the cyclic variation for AH Tau are 45.8({+-}1.1) yr and 0fd0171({+-}0fd0005), which may more likely result from the light-time effect via a third body. The secular period decrease rates are dP/dt = -1.26({+-}0.04) x 10{sup -7} days yr {sup -1} for AO Cam and dP/dt = -6.98({+-}0.07) x 10{sup -8} days yr {sup -1} for AH Tau. This kind of period decrease can be plausibly explained by the mass transfer from the primary to the secondary, and may result in the system evolving into a deep contact configuration.

  5. 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 cooled device without liquid nitrogen in very demanding environmental conditions. A successful test of this device was performed on sky on the PIONIER 4 telescopes beam combiner on the VLTi at ESOParanal in June 2014. First Light Imaging, which will commercialize a camera system using also APD infrared arrays in its proprietary wavefront sensor camera platform. These programs are held with several partners, among them are the French astronomical laboratories (LAM, OHP, IPAG), the detector manufacturers (e2v technologies, Sofradir, CEA/LETI) and other partners (ESO, ONERA, IAC, GTC, First Light Imaging). Funding is: Opticon FP7 from European Commission, ESO, CNRS and Université de Provence, Sofradir, ONERA, CEA/LETI the French FUI (DGCIS), the FOCUS Labex and OSEO.

  6. Fine Analysis of 121 Hermione, 45 Eugenia, and 90 Antiope Binary Asteroid Systems With AO Observations

    NASA Astrophysics Data System (ADS)

    Marchis, F.; Descamps, P.; Hestroffer, D.; Berthier, J.; de Pater, I.

    2004-11-01

    We report on a campaign of adaptive optics observations which focuses on 121 Hermione, 45 Eugenia, and 90 Antiope binary asteroids performed with ESO-VLT and Keck II telescopes in 2003-2004. A precessing Keplerian model was used to describe the motion of their companion. The orbital elements are determined accurately using data spanning more than 2 years. The satellite of 121 Hermione revolves at a= 775+/-14 km from the primary in P=2.5714+/-0.001 days with a low eccentricity (e=0.008+/-0.004) and retrograde orbit w.r.t. to the primary's equator (i=175+/-4 deg considering a pole solution (1.9,13.2) deg in ecliptic EQJ2000). The sense of revolution was unambiguously estimated from images separated by a few hours. Keck AO data taken in December 2003 revealed the bi-lobated shape of the primary. The nominal bulk density as derived from observed size of the primary and its 209 km IRAS diameter is 1.2+/-0.3 g/cm3 (Marchis et al., Icarus, 2004). Future observations with better angular resolution will allow us to see if 121 Hermione is a triple system. The orbit of Petit-Prince, moonlet of 45 Eugenia, was constrained using Feb. and Mar. 2004 AO data recorded at the VLT (a=1196+/-4 km, P= 4.7244+/-0.001 days, e=0, i=163+/-6 deg with a pole solution (133+/-3,-40+/-3 deg) in ecliptic B1950), leading to a bulk density of 1.17 g/cm3 considering its 215 km IRAS diameter. Both models predict successfully the positions reported for the discovery of Petit-Prince on Nov. 1998 and of S/2001 (121) 1 by Merline et al. (1999 and 2002). We will also present results on the same-size binary asteroid 90 Antiope, using the same analysis. Feb. and Mar. 2004 VLT-NACO data confirmed that both components are similar (with a Dm 2.4 and a diameter of 110+/-16 km). A preliminary analysis of Feb. and Mar. 2004 VLT data confirms that both components, separated by 170+/-1 km, with a revolution period P=16.5268 +- 0.0001h, are quasi-similar (with a Dm 2.4% and a diameter of 110+/-16 km) leading to a low bulk density of 0.6+/-0.2 g/cm3. NIR colors, shape of the primary, and motions of the apsidal lines of these binaries will be discussed. This work supported by the National Science Foundation Science and Technology Center for Adaptive Optics, is based on observations collected at the European Southern Observatory, Chile and Keck telescope, Hawaii.

  7. 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 blanket and between thermal blanket sheets of aluminized Kapton, are visible along the edges of the blanket and near Kel-F buttons used to secure the blanket. A large fragment of the material is folded over the left side of the radiator panel. The large area of discoloration on the right side of the black solar absorber panel appears to be approximately the same shape as the aluminum coating that covered the area in the flight photograph. The orientation of the remaining thin film atomic oxygen experiment patch would indicate that the patch is attached to the Dacron mesh and that the attachment is very fragile. The layer of Kapton tape that covered the ends of the thin film strips appears to be eroded with only the adhesive remaining. The remaining strips of the atomic oxygen experiment materials have changed colors and most appear to be severely degraded. The silvered TEFLON coating of the radiator panel appears diffuse with a light brown discoloration over most of the surface. The white, evenly spaced, discolorations along the horizontal centerline and along the edges of the panel appear to be above counter sunk flat head screws used to assemble the experiment. The black spots on the radiator panel appear to be impact craters that penetrated the TEFLON material and exposed the silver beneath to the atomic oxygen flux. Particles of the degraded thermal blanket material that appeared to adhere to the surface of the radiator panel in the flight photograph are gone.

  8. 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 cover a portion of the black solar absorber panel and also areas of the trays upper and lower flanges. The shadow on the tray lower flange would indicate that the aluminum extends several inches out of the tray envelope. One of the two thin film atomic oxygen experiment patches is gone and the other does not appear to be securely attached. The layer of Kapton tape over the thin film strips appears to be eroded with only the adhesive remaining. The remaining atomic oxygen experiment materials have changed colors and most appear to be severely degraded. The silvered TEFLON coating of the radiator panel appears diffuse with a light brown discoloration over most of the surface. The white, evenly spaced, discolorations along the vertical centerline and across the top of the panel appear to be above counter sunk flat head screws used to assemble the experiment. The black spots on the radiator panel appear to be impact craters where the impact penetrated the TEFLON material and exposed the silver beneath to the atomic oxygen flux. Particles of the degraded thermal blanket material appear to be adhered to the surface of the radiator panel.

  9. 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 blanket and between thermal blanket sheets of aluminized Kapton, are visible along the edges of the blanket and near Kel-F buttons used to secure the blanket. A large fragment of the material is folded over the left side of the radiator panel. The large area of discoloration on the right side of the black solar absorber panel appears to be approximately the same shape as the aluminum coating that covered the area in the flight photograph. The orientation of the remaining thin film atomic oxygen experiment patch would indicate that the patch is attached to the Dacron mesh and that the attachment is very fragile. The layer of Kapton tape that covered the ends of the thin film strips appears to be eroded with only the adhesive remaining. The remaining strips of the atomic oxygen experiment materials have changed colors and most appear to be severely degraded. The silvered TEFLON® coating of the radiator panel appears diffuse with a light brown discoloration over most of the surface. The white, evenly spaced, discolorations along the horizontal centerline and along the edges of the panel appear to be above counter sunk flat head screws used to assemble the experiment. The black spots on the radiator panel appear to be impact craters that penetrated the TEFLON® material and exposed the silver beneath to the atomic oxygen flux. Particles of the degraded thermal blanket material that appeared to adhere to the surface of the radiator panel in the flight photograph are gone.

  10. 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 cover a portion of the black solar absorber panel and also areas of the trays upper and lower flanges. The shadow on the tray lower flange would indicate that the aluminum extends several inches out of the tray envelope. One of the two thin film atomic oxygen experiment patches is gone and the other does not appear to be securely attached. The layer of Kapton tape over the thin film strips appears to be eroded with only the adhesive remaining. The remaining atomic oxygen experiment materials have changed colors and most appear to be severely degraded. The silvered TEFLON® coating of the radiator panel appears diffuse with a light brown discoloration over most of the surface. The white, evenly spaced, discolorations along the vertical centerline and across the top of the panel appear to be above counter sunk flat head screws used to assemble the experiment. The black spots on the radiator panel appear to be impact craters where the impact penetrated the TEFLON® material and exposed the silver beneath to the atomic oxygen flux. Particles of the degraded thermal blanket material appear to be adhered to the surface of the radiator panel.

  11. 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. PMID:26122819

  12. 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.

  13. Hybrid External Fixation for Arbeitsgemeinschaft fr Osteosynthesefragen (AO) 43-C Tibial Plafond Fractures.

    PubMed

    Abd-Almageed, Emad; Marwan, Yousef; Esmaeel, Ali; Mallur, Amarnath; El-Alfy, Barakat

    2015-01-01

    Arbeitsgemeinschaft fr Osteosynthesefragen (AO) type 43-C tibial plafond/pilon fractures represent a challenge for the treating orthopedic surgeon. We assessed the outcomes of using hybrid external fixation for this fracture type. The present prospective cohort study was started in August 2009 and ended by July 2012. Thirty consecutive patients (mean age37.410.7years) with a type C tibial plafond fracture who had presented to our tertiary care orthopedic hospital were included. Motor vehicle accidents and fall from height were the cause of the fracture in 14 (46.7%) and 13 (43.3%) patients, respectively. A type C3 fracture was present in 25 patients (83.3%), and type C1 and C2 fractures were present in 2 (6.7%) and 3 (10.0%) patients, respectively. Nine fractures (30.0%) were open. Hybrid external fixation was used for all fractures. All fractures were united; clinical healing was achieved by a mean of 18.12.2weeks postoperatively and radiologic healing at a mean of 18.91.9weeks. The fixator was removed at a mean of 20.42.0weeks postoperatively. At a mean follow-up point of 13.42.6months, the mean modified Mazur ankle score was 84.610.4. It was not associated with wound classification (p = .256). The most commonly seen complication was ankle osteoarthritis (17 patients; 56.7%); however, it was mild in >50.0% of the affected patients. In conclusion, using hybrid external fixation for type C tibial plafond fractures resulted in good outcomes. However, this should be investigated further in studies with a higher level of evidence. PMID:26215549

  14. An Analysis of Characteristics of Education Institutions Supported by AoA for Planning and Development of Instructional Programs in Aging.

    ERIC Educational Resources Information Center

    Craig, Bruce M.

    The institutional characteristics of postsecondary colleges and universities that were successful in all Administration on Aging (AoA) grant program competitions for career training or personnel in aging through the 1980-81 academic year are analyzed. The sustaining ability of first-time grantees in new AoA program competitions are compared to see…

  15. High energy resolution observation of the Crab and AO535 plus 26 in the hard X-ray range

    NASA Technical Reports Server (NTRS)

    Hameury, J. M.; Boclet, D.; Durouchoux, P.; Cline, T.; Teegarden, B.; Tueller, J.; Paciesas, W.; Haymes, R.

    1982-01-01

    A number of uncertainties exist currently regarding the existence of gamma-ray lines in the Crab spectrum. An investigation was, therefore, conducted, and the Crab was observed for eight hours during a balloon flight from Palestine, TX, on September 26, 1980. It appeared that the binary source AO535 plus 26 contaminated the Crab data. It was, however, possible to separate the two sources. The obtained results are discussed and evaluated. It is found that the possibility of a line at 73 keV with the intensity reported by Ling et al. (1979) can be excluded for the obtained data. The 400 keV line cannot be ruled out. The results concerning AO535 plus 26 are very different from those previously obtained.

  16. 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

  17. High energy resolution observation of the Crab and AO535 plus 26 in the hard X-ray range

    NASA Astrophysics Data System (ADS)

    Hameury, J. M.; Boclet, D.; Durouchoux, P.; Cline, T.; Teegarden, B.; Tueller, J.; Paciesas, W.; Haymes, R.

    A number of uncertainties exist currently regarding the existence of gamma-ray lines in the Crab spectrum. An investigation was, therefore, conducted, and the Crab was observed for eight hours during a balloon flight from Palestine, TX, on September 26, 1980. It appeared that the binary source AO535 plus 26 contaminated the Crab data. It was, however, possible to separate the two sources. The obtained results are discussed and evaluated. It is found that the possibility of a line at 73 keV with the intensity reported by Ling et al. (1979) can be excluded for the obtained data. The 400 keV line cannot be ruled out. The results concerning AO535 plus 26 are very different from those previously obtained.

  18. Laser guidestar uplink correction using a MEMS deformable mirror: on-sky test results and implications for future AO systems

    NASA Astrophysics Data System (ADS)

    Norton, Andrew P.; Gavel, Donald T.; Helmbrecht, Michael; Kempf, Carl; Gates, Elinor; Chloros, Kostas; Redel, Donnie; Kupke, Renate; Dillon, Daren

    2014-07-01

    By inserting a MEMS deformable mirror-based adaptive optics system into the beam transfer optics of the Shane 3-meter telescope at Mt. Hamilton, we actively controlled the wavefront of the outgoing sodium laser guidestar beam. It was possible to show that a purposefully aberrated beam resulted in poorer performance of the Adaptive Optics system located behind the primary, though bad seeing conditions prevented us from improving the system's performance over its nominal state. A silver-coated Iris AO deformable mirror was subjected to approximately 9.5 hours of exposure to a sodium laser guidestar of 3.5 Watts average output power and showed no signs of permanent damage or degradation in performance. Future applications of the uplink-AO system for correcting atmospheric turbulence and in generating custom laser guidestar asterisms are also discussed.

  19. 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.

  20. Tolerancing the fabrication errors of static optical elements for ELT-size wide-field AO systems

    NASA Astrophysics Data System (ADS)

    Véran, Jean-Pierre; Pazder, John; Herriot, Glen; Andersen, David

    2012-07-01

    Advanced wide-field AO systems, such as Multi-Conjugate AO (MCAO) systems often require many static optical elements (mirror and lenses) in addition to the active ones (deformable mirrors). These static elements induce additional wave-front errors due to random fabrication errors such as polishing errors. For ELT-size AO systems, these optical elements can be very large, and thus their cost and availability critically depends on how of much fabrication error can be tolerated. Therefore, a rigorous tolerance analysis is absolutely critical. Requirements can, in principle be relaxed, on account that fabrication errors with spatial scales larger than the inter-actuator spacing of the deformable mirrors (DMs) can be corrected. However, this process is significantly complicated by the fact that these optical elements are often conjugated far away from the DMs, and therefore DM correction cannot be achieved over a wide field of view (FOV). In this paper, we present our tolerance analysis in the context of NFIRAOS, the first-light MCAO system for the Thirty Meter Telescope. We start from two top-level error budgets: the “on-axis” error budget, which specifies the acceptable residual wave-front error in the narrow 17”x17” science FOV; and the “off-axis” error budget, which specifies the acceptable residual wave-front error at the edge of the 2’ diameter technical FOV. The former directly relates to science image quality, whereas the latter directly relates to sky coverage. For different assumptions on the spatial power spectrum of the polishing errors, we derive the requirements on each optical element in NFIRAOS using a Monte-Carlo analysis of the predicted off-axis performance of the system with on axis AO correction.

  1. AoRim15 is involved in conidial stress tolerance, conidiation and sclerotia formation in the filamentous fungus Aspergillus oryzae.

    PubMed

    Nakamura, Hidetoshi; Kikuma, Takashi; Jin, Feng Jie; Maruyama, Jun-Ichi; Kitamoto, Katsuhiko

    2016-04-01

    The serine-threonine kinase Rim15p is a master regulator of stress signaling and is required for stress tolerance and sexual sporulation in the yeast Saccharomyces cerevisiae. However, in filamentous fungi that reproduce asexually via conidiation, the physiological function of Rim15p homologs has not been extensively analyzed. Here, we functionally characterized the protein homolog of Rim15p in the filamentous fungus Aspergillus oryzae, by deleting and overexpressing the corresponding Aorim15 gene and examining the role of this protein in stress tolerance and development. Deletion of Aorim15 resulted in an increase in the sensitivity of conidia to oxidative and heat stresses, whereas conidia of the Aorim15 overexpressing strain were more resistant to these stresses. These results indicated that AoRim15 functions in stress tolerance, similar to S. cerevisiae Rim15p. Phenotypic analysis revealed that conidiation was markedly reduced by overexpression of Aorim15 in A. oryzae, and was completely abolished in the deletion strain. In addition, the formation of sclerotia, which is another type of developmental structure in filamentous fungi, was decreased by the deletion of Aorim15, whereas Aorim15 overexpression increased the number of sclerotia. These results indicated that AoRim15 is a positive regulator of sclerotia formation and that overexpression of AoRim15 shifts the developmental balance from conidiation towards sclerotia formation. Collectively, we demonstrated that AoRim15 is involved in the stress tolerance of conidia and differentially regulates between the two developmental fates of conidiation and sclerotia formation. PMID:26467693

  2. 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 survived the mission. The fiberglass-epoxy mounting strip colors have changed from the typical greenish-gray to a slate gray and the colors of the test specimen appear to be much darker than in the prelaunch photograph.

  3. 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 recomendado, este não é ensinado, nem no Ensino Fundamental, nem no Ensino Médio.

  4. 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.

  5. 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

    Complex global models developed for climate prediction are now applied to the future climate projection in a number of global modeling centers around the world. In climate prediction aspects, an atmosphere-ocean coupled model (one-tier climate system) has been recognized to exhibit useful skill for a global or certain regions (Graham et al., 2005). Wang et al. (2005) demonstrates that an AGCM coupled with an ocean model, simulates realistic SST-rainfall relationships for the Asia during the summer period. Also the transition from two-tier to one-tier approach in climate prediction are mainly caused by recent progresses in development of coupled climate models and enlargement of understanding air-sea interactions obtained from international collaborative efforts such as TOGA (the Tropical Ocean-Global Atmosphere) program (Wang et al., 2009). Meanwhile, water resource including river outflow in association with surface and sub-surface water flow is an important part of the global hydrological cycle, and is affected by climate variability and change through recharge processes (Chen et al., 2002), as well as by human interventions in many locations (Petheram et al., 2001). Also, water is critical resource to the social, economic and environmental aspects, and advances of these core elements requires improved water resource management. Better management and use of water need to abundant real time hydro-meteorological (river and weather) information as well as accurate water resource forecasting (Barrett, 1990). For this reason, many studies have recently carrying out the water resource prediction and estimation using hydrology and climate model. For example, Shiklomanov et al. (2011) predicted that water resource in Russian territory increases about 8-10% during 2010-2020 using the unit hydrograph (UH) model based on hydrologic rainfall-runoff model. Anderson et al. (2000) explained the probabilistic seasonal prediction of drought with a simplified climate model coupled 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.

  6. 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}.

  7. Immunohistochemical analysis of the A4 and AO10 (gp110) cell-surface antigens of human astrocytoma.

    PubMed Central

    Garin-Chesa, P.; Beresford, H. R.; Walker, S.; Rettig, W. J.

    1990-01-01

    The A4 and AO10 (110 kd glycoprotein) cell-surface antigens are biochemically distinct markers of cultured human astrocytomas that are expressed by only a limited number of other cultured cell types. To further characterize these two antigens, the authors used immunohistochemical methods to determine their expression in normal human tissues, astrocytomas, and over 100 tumors of other histologic types. They found that A4 is expressed 1) throughout the central (CNS), but not peripheral nervous system (PNS); 2) in smooth muscle and a small number of epithelial tissues; and 3) in reactive glia and in astrocytomas, but not in most tumors of other histologic types. In contrast, the AO10 antigen is expressed 1) in a small subset of CNS neurons, but not in astrocytes, PNS neurons, or other normal tissues; 2) in astrocytomas and reactive glia; and 3) in some additional neuroectodermal tumors, but not melanomas, carcinomas, or sarcomas. These findings show that A4 and AO10 are restricted markers for human astrocytomas in vivo. Furthermore, the antigens show distinct patterns of expression in normal human CNS but appear to be coordinately expressed in astrocytomas and astrocytoma-derived cell lines. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:2183624

  8. ShaneAO: an enhanced adaptive optics and IR imaging system for the Lick Observatory 3-meter telescope

    NASA Astrophysics Data System (ADS)

    Kupke, Renate; Gavel, Donald; Roskosi, Constance; Cabak, Gerald; Cowley, David; Dillon, Daren; Gates, Elinor L.; McGurk, Rosalie; Norton, Andrew; Peck, Michael; Ratliff, Christopher; Reinig, Marco

    2012-07-01

    The Lick Observatory 3-meter telescope has a history of serving as a testbed for innovative adaptive optics techniques. In 1996, it became one of the first astronomical observatories to employ laser guide star (LGS) adaptive optics as a facility instrument available to the astronomy community. Work on a second-generation LGS adaptive optics system, ShaneAO, is well underway, with plans to deploy on telescope in 2013. In this paper we discuss key design features and implementation plans for the ShaneAO adaptive optics system. Once again, the Shane 3-m will host a number of new techniques and technologies vital to the development of future adaptive optics systems on larger telescopes. Included is a woofer-tweeter based wavefront correction system incorporating a voice-coil actuated, low spatial and temporal bandwidth, high stroke deformable mirror in conjunction with a high order, high bandwidth MEMs deformable mirror. The existing dye laser, in operation since 1996, will be replaced with a fiber laser recently developed at Lawrence Livermore National Laboratories. The system will also incorporate a high-sensitivity, high bandwidth wavefront sensor camera. Enhanced IR performance will be achieved by replacing the existing PICNIC infrared array with an Hawaii 2RG. The updated ShaneAO system will provide opportunities to test predictive control algorithms for adaptive optics. Capabilities for astronomical spectroscopy, polarimetry, and visible-light adaptive optical astronomy will be supported.

  9. Open-loop control of SCExAO's MEMS deformable mirror using the Fast Iterative Algorithm: speckle control performances

    NASA Astrophysics Data System (ADS)

    Blain, Célia; Guyon, Olivier; Martinache, Frantz; Bradley, Colin; Clergeon, Christophe

    2012-07-01

    Micro-Electro-Mechanical Systems (MEMS) deformable mirrors (DMs) are widely utilized in astronomical Adaptive Optics (AO) instrumentation. High precision open-loop control of MEMS DMs has been achieved by developing a high accuracy DM model, the Fast Iterative Algorithm (FIA), a physics-based model allowing precise control of the DM shape. Accurate open-loop control is particularly critical for the wavefront control of High- Contrast Imaging (HCI) instruments to create a dark hole area free of most slow and quasi-static speckles which remain the limiting factor for direct detection and imaging of exoplanets. The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system is one of these high contrast imaging instruments and uses a 1024-actuator MEMS deformable mirror (DM) both in closed-loop and open-loop. The DM is used to modulate speckles in order to distinguish (i) speckles due to static and slow-varying residual aberrations from (ii) speckles due to genuine structures, such as exoplanets. The FIA has been fully integrated into the SCExAO wavefront control software and we report the FIA’s performance for the control of speckles in the focal plane.

  10. Design, Implementation, and On-Sky Performance of an Advanced Apochromatic Triplet Atmospheric Dispersion Corrector for the Magellan Adaptive Optics System and VisAO Camera

    NASA Astrophysics Data System (ADS)

    Kopon, Derek; Close, Laird M.; Males, Jared R.; Gasho, Victor

    2013-08-01

    We present the novel design, laboratory verification, and on-sky performance of our advanced triplet atmospheric dispersion corrector (ADC), an important component of the Magellan Adaptive Optics system (MagAO), which recently achieved first light in December 2012. High-precision broadband (0.5-1.0 μm) atmospheric dispersion correction at visible wavelengths is essential both for wavefront sensing (WFS) on fainter guide stars, and for performing visible AO science using our VisAO science camera. At 2 airmasses (60° from zenith) and over the waveband 500-1000 nm, our triplet design produces a 57% improvement in geometric rms spot size, a 33% improvement in encircled energy at 20'' radius, and a 62% improvement in Strehl ratio when compared to a conventional doublet design. This triplet design has been fabricated, tested in the lab, and integrated into the MagAO WFS and the VisAO science camera. We present on-sky results of the ADC in operation with the MagAO system. We also present a zero-beam-deviation triplet ADC design, which will be important to future AO systems that require precise alignment of the optical axis over a large range of airmasses in addition to diffraction-limited broadband dispersion correction.

  11. 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. PMID:11891667

  12. Clinical Utility of Electrocochleography in the Diagnosis and Management of Meniere's Disease: AOS and ANS Membership Survey Data

    PubMed Central

    Nguyen, Linda T.; Harris, Jeffrey P.; Nguyen, Quyen T.

    2010-01-01

    Objective Evaluate the clinical utility of electrocochleography (ECoG) for diagnosis/treatment of Meniere’s disease among members of the American Otological Society (AOS) and American Neurotology Society (ANS). Subjects Clinically active members of the AOS/ANS. Main Outcome Measure Survey responses. Results A total of 143 responses were received from 344 possible respondents (41.6%). In suspected cases of Meniere’s disease, 45.5% of respondents did not use ECoG at all, 17.5 % used ECoG routinely, and 37.1% used it only in questionable cases. ECoG users differed widely in electrode approach and stimulus modality used, with extratympanic approach and click stimuli used most frequently. A majority of respondents (73.2%) believed that ECoG is a test of indeterminate value. Only 3.6% required an abnormal ECoG to diagnose endolymphatic hydrops. An abnormal test was a requirement to proceed with ablative therapy for just 8.6% of respondents. Still, 77.9% believe that ECoG findings do fluctuate with activity of the disorder, but only 18.0% agree that when the ECoG reverts to normal, one can predict remission of symptoms. Almost half of respondents (46.7%) reported that they have now stopped ordering ECoG due to variability in results and lack of correlation with their patients’ symptoms. Conclusion Among AOS/ANS members, there is low clinical utility of ECoG in diagnosis/management of Meniere’s disease. For approximately half of respondents, ECoG has no role in their clinical practice. ECoG was used routinely by only one in six respondents. Those who used ECoG differed widely in electrode placement and type of stimuli paradigm used. PMID:20104195

  13. Laboratory results and status update for Pathfinder, the LINC-NIRVANA NGS ground-layer AO subsystem

    NASA Astrophysics Data System (ADS)

    Kopon, Derek; Conrad, Al; Bertram, Thomas; Herbst, Tom; Kürster, Martin; Berwein, Juergen; Ragazzoni, Roberto; Farinato, Jacopo; Viotto, Valentina; Bergomi, Maria; Rohloff, Ralf-Rainer; Baumeister, Harald; De Bonis, Fulvio; Hofferbert, Ralph; Brunelli, Alessandro; Arcidiacono, Carmelo; Pott, Jörg-Uwe; Bizenberger, Peter; Briegel, Florian; Meschke, Daniel; Mohr, Lars; Zhang, Xianyu; Kittmann, Frank

    2013-12-01

    The full LINC-NIRVANA instrument will be one of the most complex ground-based astronomical systems ever built. It will consist of multiple subsystems, including two multi-conjugate ground layer AO systems (MCAO) that drive the LBT adaptive secondaries, two mid-high layer AO systems with their own Xynetics 349 actuator DM's, a fringe tracker, and a beam combiner. In order to mitigate risk, we take a modular approach to instrument testing and commissioning by decoupling these subsystems individually. The first subsystem tested on-sky will be one of the ground-layer AO systems, part of a test-bed known as the Pathfinder. The Pathfinder consists of a 12-star pyramid WFS that drives one of the LBT's adaptive secondaries, a support structure known as "The Foot," and the infrared test camera (IRTC), which is used for acquisition and alignment. The 12 guide stars are acquired by moveable arms called "star enlargers," each of which contains its own optical path. The Pathfinder will be shipped from MPIA in Heidelberg, Germany to the LBT mountain lab on Mt. Graham, Arizona in February. The system will be unpacked, assembled in the LBT clean room, and internally optically aligned. We present the results of our system tests, including star enlarger alignment and system alignment. We also present our immediate plans for on-sky closed loop tests on the LBT scheduled for early Fall. Because plans for all ELTs call for ground layer correction, the Pathfinder provides valuable preliminary information not only for the full LINC-NIRVANA system, but also for future advanced MCAO systems.

  14. 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.

  15. 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.

  16. Intra and interobserver concordance of the AO classification system for fractures of the long bones in the pediatric population☆

    PubMed Central

    Utino, Artur Yudi; de Alencar, Douglas Rene; Fernadez Maringolo, Leonardo; Negrão, Julia Machado; Blumetti, Francesco Camara; Dobashi, Eiffel Tsuyoshi

    2015-01-01

    Objective The AO classification for fractures of the long bones in the pediatric population was developed and validated in 2006. However, the complexity of this system has limited its use in clinical practice and few studies in the literature have evaluated its reproducibility and applicability. The present study had the objective of determining the intra and interobserver agreement using the pediatric AO system, among physicians with different levels of experience. Methods After making the sample calculation, 108 consecutive radiographs on long-bone fractures in patients aged 0–16 years, coming from the digital files of the quaternary-level hospital, were selected. The radiographs were classified by five examiners with different levels of experience after prior explanations about the system. A chart containing images from the classification was made available for consultation. The evaluations were made at two different times by each observer. The Fleiss kappa index was used to ascertain the intra and interobserver agreement. Results Intraobserver agreement that was at least substantial was obtained for all the items of the classification and it reached excellent levels for all observers in relation to five of the seven items considered. The interobserver evaluation presented excellent levels of agreement in two items, substantial in two items, moderate to substantial in one item and poor to moderate in one item. No influence from the observer's experience was observed with regard to obtaining higher or lower levels of agreement, either in the intraobserver or in the interobserver evaluation. Conclusions In this study, the intra and interobserver agreement was considered to be good or excellent for the pediatric AO classification system, for the parameters of bone, segment, paired bone, subsegment, standard and deviation. However, the intra and interobserver agreement was statistically unsatisfactory for the parameter of severity/side of avulsion. The levels of agreement obtained did not depend on the observer's level of experience within pediatric orthopedics. PMID:26535194

  17. Optimal sensor arrangements in Angle of Arrival (AoA) and range based localization with linear sensor arrays.

    PubMed

    Herath, Sanvidha C K; Pathirana, Pubudu N

    2013-01-01

    This paper investigates the linear separation requirements for Angle-of-Arrival (AoA) and range sensors, in order to achieve the optimal performance in estimating the position of a target from multiple and typically noisy sensor measurements. We analyse the sensor-target geometry in terms of the Cramer-Rao inequality and the corresponding Fisher information matrix, in order to characterize localization performance with respect to the linear spatial distribution of sensors. Here in this paper, we consider both fixed and adjustable linear sensor arrays. PMID:24036585

  18. Optimal Sensor Arrangements in Angle of Arrival (AoA) and Range Based Localization with Linear Sensor Arrays

    PubMed Central

    Herath, Sanvidha C. K.; Pathirana, Pubudu N.

    2013-01-01

    This paper investigates the linear separation requirements for Angle-of-Arrival (AoA) and range sensors, in order to achieve the optimal performance in estimating the position of a target from multiple and typically noisy sensor measurements. We analyse the sensor-target geometry in terms of the Cramer–Rao inequality and the corresponding Fisher information matrix, in order to characterize localization performance with respect to the linear spatial distribution of sensors. Here in this paper, we consider both fixed and adjustable linear sensor arrays. PMID:24036585

  19. Production and characterisation of AoSOX2 from Aspergillus oryzae, a novel flavin-dependent sulfhydryl oxidase with good pH and temperature stability.

    PubMed

    Faccio, Greta; Kruus, Kristiina; Buchert, Johanna; Saloheimo, Markku

    2011-05-01

    Sulfhydryl oxidases have found application in the improvement of both dairy and baking products due to their ability to oxidise thiol groups in small molecules and cysteine residues in proteins. A genome mining study of the available fungal genomes had previously been performed by our group in order to identify novel sulfhydryl oxidases suitable for industrial applications and a representative enzyme was produced, AoSOX1 from Aspergillus oryzae (Faccio et al. BMC Biochem 11:31, 2010). As a result of the study, a second gene coding for a potentially secreted sulfhydryl oxidase, AoSOX2, was identified in the genome of A. oryzae. The protein AoSOX2 was heterologously expressed in Trichoderma reesei and characterised with regard to both biochemical properties as well as preliminary structural analysis. AoSOX2 showed activity on dithiothreitol and glutathione, and to a lesser extent on D/L-cysteine and beta-mercaptoethanol. AoSOX2 was a homodimeric flavin-dependent protein of approximately 78 kDa (monomer 42412 Da) and its secondary structure presents alpha-helical elements. A. oryzae AoSOX2 showed a significant stability to pH and temperature. PMID:21327412

  20. 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.

  1. Evaluation of a novel integrated bioreactor--AOS system for treating oil-containing restaurant wastewater on site in Hong Kong.

    PubMed

    Wang, L; Zhou, Q; Chua, H

    2005-01-01

    AOS system is an anaerobic digestion reactor (A-section, UASB or UBF), oxidation degradation reactor (O-section, aerobic biofilm reactor), and physical sedimentation tank (S-section) 3-in-1 integrated reactor. The compact bioreactor was applied to treat oil-containing restaurant's wastewater on site in Hong Kong. The treatment efficiency was observed at different HRT. Experimental results indicated that the AOS system for treating oil-containing restaurant wastewater on site was feasible when HRT at 0.6 days above. During the running period, the net sludge generation rate of the AOS system was only about 0.08-0.09 g g(-1)removed COD, and the utmost COD specific volumetric removal rate (SVRR) of the system reached 2.77 gL(-1) d(-1). The utmost specific biomass substrate utilization rate (SBSUR) of COD in O-section and A-section reached 1.22 d(-1) and 0.128 d(-1), respectively. In addition, the experiment results showed that the AOS system with a filter in UASB (that is UBF's AOS system) could bear much more great HLR comparing with UASB's AOS and was more efficient for treating oil-containing restaurant's wastewater on site. PMID:15663313

  2. Evidence of a plasmid-encoded oxidative xylose-catabolic pathway in Arthrobacter nicotinovorans pAO1.

    PubMed

    Mihasan, Marius; Stefan, Marius; Hritcu, Lucian; Artenie, Vlad; Brandsch, Roderich

    2013-01-01

    Due to its high abundance, the D-xylose fraction of lignocellulose provides a promising resource for production of various chemicals. Examples of efficient utilization of d-xylose are nevertheless rare, mainly due to the lack of enzymes with suitable properties for biotechnological applications. The genus Arthrobacter, which occupies an ecological niche rich in lignocellulosic materials and containing species with high resistance and tolerance to environmental factors, is a very suitable candidate for finding D-xylose-degrading enzymes with new properties. In this work, the presence of the pAO1 megaplasmid in cells of Arthrobacter nicotinovorans was directly linked to the ability of this microorganism to ferment D-xylose and to sustain longer log growth. Three pAO1 genes (orf32, orf39, orf40) putatively involved in degradation of xylose were identified and cloned, and the corresponding proteins purified and characterized. ORF40 was shown to be a homotetrameric NADP(+)/NAD(+) sugar dehydrogenase with a strong preference for d-xylose; ORF39 is a monomeric aldehyde dehydrogenase with wide substrate specificity and ORF32 is a constitutive expressed transcription factor putatively involved in control of the entire catabolic pathway. Based on analogies with other pentose degradation pathways, a putative xylose oxidative pathway similar to the Weimberg pathway is postulated. PMID:23063486

  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. PMID:25723066

  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. Use of a single 2.0-mm locking AO reconstruction titanium plate in linear, non-comminuted, mandible fractures

    PubMed Central

    Parmar, Babu S.; Makwana, Kalpesh G.; Patel, Aditi M.; Tandel, Ramanuj C.; Shah, Jay

    2014-01-01

    Purpose: The aim of the following study is to prospectively evaluate the use of a single Arbeitsgemeinschaft für Osteosynthesefragen (AO) 2.0-mm locking reconstruction plate for linear non-comminuted mandibular fractures without the use of a second plate. Materials and Methods: This study consisted of a sample of 10 patients who reported to the department with fractures of the mandible and were treated over a period of 24 months from November 2010 to November 2012. Out of these, there were 8 male patients and 2 female patients. There were four cases of isolated parasymphysis fractures, 1 of the case had a parasymphysis fracture associated with subcondylar fracture, 4 had a body fracture and 2 had a symphysis fracture. Results: All patients had satisfactory fracture reduction and a successful treatment outcome without major complications. Only one patient (10%) developed minor complications. Conclusion: The study has demonstrated that treating linear non-comminuted mandibular fractures with a single AO 2.0-mm locking reconstruction plate provides excellent stability at the fracture site which in turn leads to sound bone healing and early functional rehabilitation. PMID:24987599

  6. Degradation of typical N-nitrosodimethylamine (NDMA) precursors and its formation potential in anoxic-aerobic (AO) activated sludge system.

    PubMed

    Wang, Lin; Li, Yongmei; He, Guodong

    2014-01-01

    N-nitrosodimethylamine (NDMA) is an emerging disinfection byproduct. Removal of its potential precursors is considered as an effective method to control NDMA. In this study, four typical NDMA precursors (dimethylamine (DMA), trimethylamine (TMA), dimethylformamide (DMFA) and dimethylaminobenzene (DMAB)) were selected, and their removal capacities by activated sludge were investigated. Batch experiments indicated that removal of NDMA precursors was better under aerobic condition than anoxic condition; and their specific degradation rates follow the order of DMA > TMA > DMFA > DMAB. In anoxic-aerobic (AO) activated sludge system, the optimal hydraulic retention time and sludge retention time were 10 h and 20 d, respectively, for the removal of both NDMA precursors (four selected NDMA precursors and NDMA formation potential (NDMA FP)) and nutrients. Our results also suggested that there was a positive correlation between NDMA FP and dissolved organic nitrogen (DON) in wastewater. The removal efficiency of NDMA FP was in the range of 46.8-72.5% in the four surveyed wastewater treatment plants except the one which adopted chemically enhanced primary process. The results revealed that the AO system had the advantage of removing NDMA FP. Our results are helpful for the knowledge of the removals of NDMA precursors during activated sludge treatment processes. PMID:25320860

  7. Tetrahedral tilting and ferroelectricity in Bi2AO5 (A=Si, Ge) from first principles calculations

    NASA Astrophysics Data System (ADS)

    Park, Janghee; Kim, Bog G.; Mori, Shigeo; Oguchi, Tamio

    2016-03-01

    The properties of a tetrahedron containing Bi2AO5 (A=Si, Ge) are examined using Ab initio calculations and symmetry mode analysis. Stabilization of the polar phase is observed in both compounds with a monoclinic Cc phase. In the monoclinic ground state, the tilting angle (ϕ1) of tetrahedron is 7.21° and 21.94° for the Si and Ge compound, respectively. The relationship between a primary order parameter and the tetrahedral tilting is identified and an analytical formula between them is proposed by analyzing the structure. The detailed layer-by-layer polarization calculations shows that the main polarization component originates from the tetrahedron tilting of the AO4 unit, and the analytical relationship between the primary order parameter and spontaneous polarization is also calculated. This B3LYP hybrid functional calculation provides a band gap of 4.44 eV and 4.18 eV for Bi2SiO5 and Bi2GeO5, respectively. The main difference between the two compounds is also analyzed based on the electronic structure and electron localization function analysis.

  8. Prolonged plume volcanism in the Caribbean Large Igneous Province: New insights from Curaçao and Haiti

    NASA Astrophysics Data System (ADS)

    Loewen, Matthew W.; Duncan, Robert A.; Kent, Adam J. R.; Krawl, Kyle

    2013-10-01

    We present 36 new 40Ar-39Ar incremental heating age determinations from the Caribbean Large Igneous Province (CLIP) providing evidence for extended periods of volcanic activity and suggest a new tectonomagmatic model for the province's timing and construction. These new 40Ar-39Ar ages for the Curaçao Lava Formation (CLF) and Haiti's Dumisseau Formation show evidence for active CLIP volcanism from 94 to 63 Ma. No clear changes in geochemical character are evident over this period. The CLF has trace element signatures (e.g., Zr/Nb = 10-20) and flat rare earth element (REE) trends consistent with plume volcanism. The Dumisseau Formation also has plume-like geochemistry and steeper REE trends similar to ocean island basalts. Volcanism in the Dumisseau Formation appears to have largely ceased by 83 Ma while at Curaçao it continued until 63 Ma. A rapidly surfacing and melting plume head alone does not fit this age distribution. Instead, we propose that the residual Galapagos plume head, following initial ocean plateau construction, was advected eastward by asthenospheric flow induced by subducting oceanic lithosphere. Slab rollback at the Lesser Antilles and Central America subduction zones created an extensional regime within the Caribbean plate. Mixing of plume with upwelling asthenospheric mantle provided a source for intermittent melting and eruption through the original plateau over a ˜30 Ma period.

  9. Implications of 187Os isotopic heterogeneities in a mantle plume: evidence from Gorgona Island and Curaçao

    NASA Astrophysics Data System (ADS)

    Walker, Richard J.; Storey, Michael; Kerr, Andrew C.; Tarney, John; Arndt, Nicholas T.

    1999-03-01

    Recent work has suggested that the mafic-ultramafic volcanism in evidence throughout portions of the Caribbean, Central America, and northern South America, including the islands of Gorgona and Curaçao, was generated as part of a middle-Cretaceous, large igneous province. New Re-Os isochron results for tholeiitic basalts from Gorgona and Curaçao indicate crystallization ages of 89.2 ± 5.2 and 85.6 ± 8.1 Ma, respectively, consistent with reported Ar ages. The Gorgona ultramafic suite shows a large range in initial Os isotopic composition, with γ Os values ranging from -0.5 to +12.4. This large range reflects isotopic heterogeneities in the mantle source similar to those observed for modern ocean island basalts. In contrast to ocean island basalts, however, Os isotopic compositions do not correlate with variations in Nd, Sr, or Pb isotopic compositions, which are within the range of depleted mid-ocean ridge basalts. The processes that produced these rocks evidently resulted in the decoupling of Os isotopes from the Nd, Sr, and Pb isotopic systems. Picrites from Curaçao have very uniform, chondritic initial Os isotopic compositions, with initial γ Os values ranging only from -0.4 to ±1.4. Basalts from Curaçao, however, define an isochron with a 187Os-enriched initial isotopic composition (γ Os = +9.5). In contrast to the 187Os-enriched ultramafic rocks from Gorgona, the enrichment in these basalts could have resulted from lithospheric contamination. If the Gorgona and Curaçao rocks were derived from the same plume, Os results, combined with Sr, Nd, and Pb data indicate a heterogeneous plume, with multiple compositionally and isotopically distinct domains. The Os isotopic results require derivation of Os from a minimum of two distinct reservoirs, one with a composition very similar to the chondritic average and one with long-term enriched Re/Os. Oceanic crustal recycling has been invoked to explain most of the 187Os enrichments that have been observed in ocean island basalt sources and could potentially apply to the Gorgona suite. Crustal recycling, however, requires large proportions of very ancient recycled basaltic crust in the sources of the 187Os-enriched ultramafic rocks to explain the magnitude of 187Os enrichments observed. For example, addition of 20% oceanic crust to fertile mantle, and nearly 3 billion years are necessary to generate a reservoir with the Os isotopic composition of the most radiogenic komatiites. If the recycled oceanic crust was added to basalt-depleted mantle, as may be indicated by ɛ Nd values for the komatiites averaging about +10, even larger proportions of older crust are required. Large proportions of oceanic mafic crust in the sources of the 187Os-enriched komatiites, although petrologically conceivable under certain melting conditions, is unlikely here given the limited trace element and lithophile isotope system variations. These results raise questions about the efficacy of using Os isotopes to constrain the proportion of recycled oceanic crust in other plumes. Other possible mechanisms for generating 187Os-enriched mantle include invoking the existence of a 187Os-enriched lower mantle, and minor outer core-lower mantle interactions.

  10. 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.

  11. 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.

  12. Clinical therapeutic effects of AO/ASIF clavicle hook plate on distal clavicle fractures and acromioclavicular joint dislocations

    PubMed Central

    Dou, Qingjun; Ren, Xiaofeng

    2014-01-01

    Objective: The aim of this study was to evaluate the security and effectiveness of AO/ASIF clavicle hook plate in the treatment of distal clavicle fractures and acromioclavicular joint dislocations. Methods: One hundred patients with distal clavicle fractures and acromioclavicular joint dislocations who were admitted in our hospital from January 2012 to January 2013 were selected as the study subjects. They were then randomly divided into a control group and an observation group (n=50). The observation group was treated with AO/ASIF clavicle hook plates, and the control group was treated with Kirschner-wire tension bands. The outcomes were recorded and compared. Results: The JOA scores of the two groups were similar before surgery (P>0.05). The two groups both had obviously increased JOA scores in the postoperative 6th and 12th weeks, and the score in the postoperative 12th week was higher. There were statistically significant intra-group differences (P<0.05). The postoperative 6th-week and 12th-week JOA scores of the observation group were (83.2±1.8) and (97.4±1.5) respectively, and those of the control group were (71.6±2.2) and (82.3±2.6) respectively, with statistically significant inter-group differences (P<0.05). Significantly more patients in the observation group (100%) were evaluated as excellent or good outcomes after fixation than those in the control group (60%). After removal of the surgical apparatus, the recurrence rates of bone fracture and joint dislocation in the observation group were significantly lower than those of the control group (P<0.05). Conclusion: AO/ASIF clavicle hook plate functioned more effectively than Kirschner-wire tension band in clinical treatment of distal clavicle fractures and acromioclavicular joint dislocations. The former protocol enjoyed small incisions, firm fixation and early shoulder mobility. Therefore, it is a safe and effective surgical method that is worthy of being widely applied in clinical practice. PMID:25097534

  13. 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.

  14. 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.

  15. Swimming with ShARCS: comparison of on-sky sensitivity with model predictions for ShaneAO on the Lick Observatory 3-meter telescope

    NASA Astrophysics Data System (ADS)

    Srinath, Srikar; McGurk, Rosalie; Rockosi, Constance; Kupke, Renate; Gavel, Donald; Cabak, Gerald; Cowley, David; Peck, Michael; Ratliff, Christopher; Gates, Elinor; Dillon, Daren; Norton, Andrew; Reining, Marc

    2014-08-01

    The Lick Observatory's Shane 3-meter telescope has been upgraded with a new infrared instrument (ShARCS - Shane Adaptive optics infraRed Camera and Spectrograph) and dual-deformable mirror adaptive optics (AO) system (ShaneAO). We present first-light measurements of imaging sensitivity in the Ks band. We compare mea- sured results to predicted signal-to-noise ratio and magnitude limits from modeling the emissivity and throughput of ShaneAO and ShARCS. The model was validated by comparing its results to the Keck telescope adaptive optics system model and then by estimating the sky background and limiting magnitudes for IRCAL, the pre- vious infra-red detector on the Shane telescope, and comparing to measured, published results. We predict that the ShaneAO system will measure lower sky backgrounds and achieve 20% higher throughput across the JHK bands despite having more optical surfaces than the current system. It will enable imaging of fainter objects (by 1-2 magnitudes) and will be faster to reach a fiducial signal-to-noise ratio by a factor of 10-13. We highlight the improvements in performance over the previous AO system and its camera, IRCAL.

  16. Faint Field Galaxies from z ˜1 to 0.5 - New Merger Results from Keck AO and NIRC2

    NASA Astrophysics Data System (ADS)

    Barczys, M.; Larkin, J. E.; Glassman, T. M.; LaFreniere, D.; Matthews, K.; Althouse, W. E.; Campbell, R. D.; Conrad, A.; Egami, E.; Goodrich, R. W.; Honey, A.; Lin, S.; McLean, I. S.; Le Mignant, D.; Neugebauer, G.; Sawicki, M.; Soifer, B. T.; Spencer, M.; Thompson, D. M.; Wizinowich, P.

    2004-12-01

    We have used the Keck Adaptive Optics System and its wide-field, near-infrared imager (NIRC2) to image nearly 300 faint field galaxies at high spatial resolution (50 to 80 milliarcseconds). The imaged galaxies lie within the isoplanatic regions of several natural AO guide stars, and are as faint as H≈23 mag (Vega). In this sample, we find that over 20 companions within 2" (≤ 15 kpc at z ˜ 0.6). Within 0.5 - 1.0", there is a three-fold overdensity of companions compared to random galaxy fields. Moreover, the relative magnitude of the galaxy pairs indicates that all are likely to be minor merger events. Unlike related optical studies, we find no evidence for major merger activity in this sample.

  17. Open Reduction for AO/OTA 81-B3 (Hawkins 3) Talar Neck Fractures: The Natural Delivery Method.

    PubMed

    Simpson, R B; Auston, Darryl A

    2016-03-01

    Fractures of the talar neck with subtalar and tibiotalar joint dislocation (AO/OTA 81-B3) represent a treatment challenge for the orthopedic surgeon. The magnitude of deformity and complexity of the pathoanatomy adds to concerns for soft tissue embarrassment to convey an urgency of surgical intervention. Previous studies have described the several techniques for talar reduction, including medial malleolar osteotomy, posterior Schanz pin manipulation, or posteromedial incision to facilitate relocation at the time of definitive open treatment. We describe a simple technique for stepwise surgical intervention using adjuncts to reduction on the surgical field that facilitate an atraumatic relocation of the displaced body fragment through a standard lateral incision, simplifying fixation of the residual talar neck fracture. A reasonable metaphor for the technique is its similarity to reducing an obstetric shoulder dystocia in the delivery of a newborn infant. PMID:26709817

  18. Long-term dynamics of the brown macroalga Lobophora variegata on deep reefs in Curaçao

    NASA Astrophysics Data System (ADS)

    Nugues, M. M.; Bak, R. P. M.

    2008-06-01

    Lobophora variegata occurs in the eulittoral zone and in deep water on coral reefs in Curaçao. An analysis of the long-term (1979-2006) changes in the vertical distribution of the macroalga in permanent quadrats indicated a significant increase in cover of the deepwater community. In 1998, Lobophora covered 1 and 5% of the quadrats at 20 and 30 m, respectively. By 2006, these values had risen to 25 and 18%, precipitating a shift in abundance of corals and macroalgae at both depths. This increase coincided with losses in coral cover, possibly linked to bleaching, disease and storm-related mortality in deep water plating Agaricia corals. In contrast, macroalgae remained relatively rare (<6% cover) on shallower (10 m) and deeper (40 m) reefs despite declines in coral cover also occurring at these depths, illustrating the depth-dependent dynamics of coral reefs. Several hypotheses are suggested to explain these changes.

  19. 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

  20. Characterization of OCam and CCD220: the fastest and most sensitive camera to date for AO wavefront sensing

    NASA Astrophysics Data System (ADS)

    Feautrier, Philippe; Gach, Jean-Luc; Balard, Philippe; Guillaume, Christian; Downing, Mark; Hubin, Norbert; Stadler, Eric; Magnard, Yves; Skegg, Michael; Robbins, Mark; Denney, Sandy; Suske, Wolfgang; Jorden, Paul; Wheeler, Patrick; Pool, Peter; Bell, Ray; Burt, David; Davies, Ian; Reyes, Javier; Meyer, Manfred; Baade, Dietrich; Kasper, Markus; Arsenault, Robin; Fusco, Thierry; Diaz-Garcia, José Javier

    2010-07-01

    For the first time, sub-electron read noise has been achieved with a camera suitable for astronomical wavefront-sensing (WFS) applications. The OCam system has demonstrated this performance at 1300 Hz frame rate and with 240×240-pixel frame rate. ESO and JRA2 OPTICON2 have jointly funded e2v technologies to develop a custom CCD for Adaptive Optics (AO) wavefront sensing applications. The device, called CCD220, is a compact Peltier-cooled 240×240 pixel frame-transfer 8-output back-illuminated sensor using the EMCCD technology. This paper demonstrates sub-electron read noise at frame rates from 25 Hz to 1300 Hz and dark current lower than 0.01 e-/pixel/frame. It reports on the comprehensive, quantitative performance characterization of OCam and the CCD220 such as readout noise, dark current, multiplication gain, quantum efficiency, charge transfer efficiency... OCam includes a low noise preamplifier stage, a digital board to generate the clocks and a microcontroller. The data acquisition system includes a user friendly timer file editor to generate any type of clocking scheme. A second version of OCam, called OCam2, was designed offering enhanced performances, a completely sealed camera package and an additional Peltier stage to facilitate operation on a telescope or environmentally rugged applications. OCam2 offers two types of built-in data link to the Real Time Computer: the CameraLink industry standard interface and various fiber link options like the sFPDP interface. OCam2 includes also a modified mechanical design to ease the integration of microlens arrays for use of this camera in all types of wavefront sensing AO system. The front cover of OCam2 can be customized to include a microlens exchange mechanism.

  1. Prolonged Mantle Melting Revealed in the Curaçao Lava Formation: Implications for the Origin of the Caribbean Plateau

    NASA Astrophysics Data System (ADS)

    Krawl, K.; Duncan, R. A.; Kent, A. J.; Loewen, M.

    2013-12-01

    The Curaçao Lava Formation (CLF), a ~5 km thick section of submarine-erupted lava flows, hyaloclastites, dikes and sills, provides a ~30 Ma record of the magmatic processes involved in the formation of the Caribbean Large Igneous Province (CLIP). The CLF presents ol-tholeiitic and picritic compositions, exposed along the southern transform margin of the CLIP, that are typical of other in situ and tectonized pieces of this ocean plateau. The wide range of recently acquired 40Ar-39Ar ages (62 to 93 Ma) obtained for the Curaçao lavas contradicts previous proposals that the CLF formed over a relatively short period (1-2 million years), but is similar to extended volcanic histories recorded in Haiti (Dumisseau Fm) and at the Beata Ridge. Petrochemical modeling using MELTS indicates that the CLF rock compositions could have formed by fractional crystallization of high-MgO parental magmas with broadly similar major element contents, generated during multiple melting events over this prolonged period. The persistently flat rare earth element patterns in rocks spanning the full age range of the CLF can be reproduced by 10-30% partial melting of a predominantly depleted mantle source with a minor enriched component. The geochemical and age data and modeling results are consistent with a mantle dynamic model for the CLIP in which lateral displacement of mantle plume head material beneath the Caribbean plateau results from subduction-driven mantle flow, which allows for the generation of magmas from a continuously replenished mantle source over approximately 30 million years. While no subduction influence is seen in CLF compositions, the island does record intrusive, arc-related rocks.

  2. A useful surgical strategy for proximal tibial fractures (AO/OTA type 41-C) with diaphyseal involvement

    PubMed Central

    Wu, Dankai; Reng, Guangkai; Shrivastava, Ankit; Yu, Ying; Zhang, Yueyang; Peng, Chuangang

    2015-01-01

    Relatively few studies have addressed surgical strategy for complex proximal tibial fractures by now. The purpose of this study was to assess the results of a single lateral locking plate using minimally invasive plate osteosynthesis (MIPO) for proximal tibia fractures (AO/OTA type 41-C) with diaphyseal involvement. From Jun 2009 to Jun 2014, 20 patients (fifteen women and five men, mean age 35.8 years) were managed for proximal tibial fractures which extend into the diaphyseal region of the bone, including three 41-C1, eleven 41-C2, and six 41-C3. Twelve patients were open fractures. A single lateral locking plate characterized by percutaneous technology was used with or without additional lag screws. Mobilization was started immediately after the procedure, and non-weight-bearing was maintained for at least 6 weeks, then progressively weight bearing depends on both clinical and x-ray findings. Primary union was achieved by 16 of the 20 study subjects. Early bone grafting was performed in 4 cases with a massive initial bone defect and staged bone grafting was used in one to treat nonunion. The mean articular step off was 1.0 mm (range, 0-3 mm). No patient had misalignment greater than 10°. Acceptable range of knee motion of ≥120° was achieved in sixteen, and the mean knee Hass score was 87.4 at final follow-up visits. The complications included superficial infection in one patient. In conclusion, the surgical strategy can provide favorable results in the treatment of proximal tibial fractures (AO/OTA type 41-C) with diaphyseal involvement. PMID:26550282

  3. Dealing with the forecast of the optical turbulence as a tool to support astronomy assisted by AO facilities

    NASA Astrophysics Data System (ADS)

    Masciadri, Elena; Lascaux, Franck; Fini, Luca

    2015-04-01

    In the context of the research activities related to the forecast of the optical turbulence and the atmospherical parameters being relevant for ground-based astronomy we focus here our attention on two specific topics: 1. pros and cons of different solutions to supply wind speed and direction stratification on the whole atmosphere all along a night to support AO facilities; 2. the necessity of instrumentation for optical turbulence monitoring (vertical profiles on the whole atmosphere) to be used operationally. In the last two decades the development and the use of different vertical profilers covering the whole atmosphere or part of it in application to the astronomy took place. Several instruments based on different principles (with associated pros and cons) have been applied in different contexts in astronomy with a main use in the site characterization and site selection. Time changed and the necessity of the astronomy supported by AO facilities is much more demanding with a diversification of applications. Recently, motivated by a precise necessity related to the identification of an absolute reference to carry out studies on optical turbulence forecasts (MOSE project), we carried out a verification of the reliability of a few instruments that lead us to put in evidence some limitations for a few of them. At the same time such a detailed analysis permitted us to clarify the nature of some astroclimatic parameters. The main conclusion at which we arrived is two-fold. From one side we could trace a list of warnings related to different uses of such instruments. On the other side we could identify open problems that indicate that there is still space for research in the field of turbulence monitoring in application to the astronomy. Some suggestions are proposed.

  4. 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. PMID:26692462

  5. 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.

  6. Constrained Local UniversE Simulations: a Local Group factory

    NASA Astrophysics Data System (ADS)

    Carlesi, Edoardo; Sorce, Jenny G.; Hoffman, Yehuda; Gottlöber, Stefan; Yepes, Gustavo; Libeskind, Noam I.; Pilipenko, Sergey V.; Knebe, Alexander; Courtois, Hélène; Tully, R. Brent; Steinmetz, Matthias

    2016-05-01

    Near-field cosmology is practised by studying the Local Group (LG) and its neighbourhood. This paper describes a framework for simulating the `near field' on the computer. Assuming the Λ cold dark matter (ΛCDM) model as a prior and applying the Bayesian tools of the Wiener filter and constrained realizations of Gaussian fields to the Cosmicflows-2 (CF2) survey of peculiar velocities, constrained simulations of our cosmic environment are performed. The aim of these simulations is to reproduce the LG and its local environment. Our main result is that the LG is likely a robust outcome of the ΛCDMscenario when subjected to the constraint derived from CF2 data, emerging in an environment akin to the observed one. Three levels of criteria are used to define the simulated LGs. At the base level, pairs of haloes must obey specific isolation, mass and separation criteria. At the second level, the orbital angular momentum and energy are constrained, and on the third one the phase of the orbit is constrained. Out of the 300 constrained simulations, 146 LGs obey the first set of criteria, 51 the second and 6 the third. The robustness of our LG `factory' enables the construction of a large ensemble of simulated LGs. Suitable candidates for high-resolution hydrodynamical simulations of the LG can be drawn from this ensemble, which can be used to perform comprehensive studies of the formation of the LG.

  7. Theoretical Studies in Nuclear Physics. [Oregon State Univ. , Corvallis, Oregon

    SciTech Connect

    Landau, R.H.; Madsen, V.A.

    1992-01-01

    Work in nuclear structure and reaction theory, specifically, the relation of reactions to the nuclear structure. Other work was in intermediate energy physics, few-body problems, and computational physics that heavy ions can be used to measure simultaneously both neutron and proton multipole matrix elements of the target nucleus has added new interest to this area of nuclear structure. Considerable attention to the is therefore paid to the to the methods for calculating multiple matrix elements.

  8. Nuclear structure studies. [Dept. of Chemistry, Univ. of Maryland

    SciTech Connect

    Walters, W.B.

    1992-08-31

    New results are reported for the decay and nuclear orientation of [sup 114,116]I and [sup 114]Sb as well as data for the structure of daughter nuclides [sup 114,116]Te. New results for IBM-2 calculations for the structure of [sup 126]Xe are also reported. A new approach to the problem of the underproduction of A = 120 nuclides in the astrophysical r-process is reported.

  9. 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.

  10. Constrained Local UniversE Simulations: A Local Group Factory

    NASA Astrophysics Data System (ADS)

    Carlesi, Edoardo; Sorce, Jenny G.; Hoffman, Yehuda; Gottlöber, Stefan; Yepes, Gustavo; Libeskind, Noam I.; Pilipenko, Sergey V.; Knebe, Alexander; Courtois, Hélène; Tully, R. Brent; Steinmetz, Matthias

    2016-02-01

    Near field cosmology is practiced by studying the Local Group (LG) and its neighbourhood. The present paper describes a framework for simulating the "near field" on the computer. Assuming the ΛCDM model as a prior and applying the Bayesian tools of the Wiener filter (WF) and constrained realizations of Gaussian fields to the Cosmicflows-2 (CF2) survey of peculiar velocities, constrained simulations of our cosmic environment are performed. The aim of these simulations is to reproduce the LG and its local environment. Our main result is that the LG is likely a robust outcome of the LCDM scenario when subjected to the constraint derived from CF2 data, emerging in an environment akin to the observed one. Three levels of criteria are used to define the simulated LGs. At the base level, pairs of halos must obey specific isolation, mass and separation criteria. At the second level the orbital angular momentum and energy are constrained and on the third one the phase of the orbit is constrained. Out of the 300 constrained simulations 146 LGs obey the first set of criteria, 51 the second and 6 the third. The robustness of our LG `factory' enables the construction of a large ensemble of simulated LGs. Suitable candidates for high resolution hydrodynamical simulations of the LG can be drawn from this ensemble, which can be used to perform comprehensive studies of the formation of the nature of the LG.

  11. 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.

  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. 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)

  14. Dust and Diffuse Interstellar Bands in the za = 0.524 Absorption System toward AO 0235+164

    NASA Astrophysics Data System (ADS)

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

    2004-10-01

    We present new Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) NUV-MAMA and STIS CCD observations of the BL Lac object AO 0235+164 and the intervening damped Lyα (DLA) line at za=0.524. The line profile gives N(HI)=(5+/-1)×1021 cm-2 and, combined with the H I 21 cm absorption data, leads to a spin temperature of Ts=220+/-60 K. Those spectra also show a strong, broad feature at the expected position of the 2175 Å graphitic dust feature at za=0.524. Assuming a Galactic-type dust extinction curve at za=0.524 gives a dust-to-gas ratio of 0.19 times the Galactic value, but the fit, assuming that the underlying, unreddened spectrum is a single power law, is poor in the far-UV. A dust-to-gas ratio of 0.19 times the Galactic value is similar to the LMC, but the AO 0235+164 spectrum does not fit either the LMC extinction curve or the SMC extinction curve (which has practically no 2175 Å feature). A possible interpretation includes dust similar to that in the Galaxy, but with fewer of the small particles that produce the far-UV extinction. The metallicity of the za=0.524 absorber, estimated from the observed N(HI) and excess X-ray absorption (beyond Galactic) derived from contemporaneous and archival ASCA and ROSAT X-ray data, is Z=0.72+/-0.28 Zsolar, implying in turn a dust-to-metals ratio of 0.27 times the Galactic value. If the dust mass density is the same in the za=0.524 DLA system as in our Galaxy, only 14% (+/-6%) of the metals (by mass) are in dust, compared to 51%, 36%, and 46% for the Galaxy, LMC, and SMC, respectively. Such a dusty za=0.524 AO 0235+164 absorption system is a good example of the kind of DLA system that will be missed because of selection effects, which in turn can bias the measurement of the comoving density of interstellar gas (in units of the closure density), Ωg, as a function of z. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  15. 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. In particular, we compared V6.03 and V5.0 trends of T(p), q(p), alpha-Epsilon, OLR, and OLR(sub CLR) computed based on results for these 12 time periods

  16. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04 EL-1994-00391 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC prior to removal of the experiment tray from the LDEF. The paint dots on the experiment tray clamp blocks, originally white, appearsDE:to be discolored by a brown stain. The experiment tray flanges also appear to be coated but with a lighter colored stain. The UHCRE detectors were contained in 16 peripheral LDEF trays with at leastDE: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 experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be specular and intact with no apparent damage. It appears less taut than in the flight photograph. The uniformly located oval spots on the thermal cover are areas where Velcro pads attach the thermal cover to the support frame and appear more visible than in the prelaunch photograph. The scallop effect around the cover edges occurs between the cover attach points and shows the upper edge of the support frame. The ground strap appears to be in place with no visible damage.

  17. 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 experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears specular and intact with no apparent damage. A vertical strip of discoloration, approximately six inches wide and with a grain pattern, extends from top to bottom along the left side of the thermal cover. The cover appears less taut than in the flight photograph and locations of the Velcro attach pads are not as prominent. The ground strap appears to be in place with no visible damage, however, the color appears darked than in the prelaunch photograph.

  18. LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C08

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C08 EL-1994-00661 LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C08 The flight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) 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 block of the experiment trays upper flange and the right end of the experiment trays lower flange appear to be slightly discolored. The tray flanges appear to be discolored by a light brown stain and the ground strap located in the center of the lower flange appears intact but a much darker copper color than in the prelaunch photograph. 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 experiments thermal cover and the LDEF structure. The UHCRE thermal covers surface appears to have changed from specular to opaque (glossy white) marked with many black dots of various sizes that appear to be impact craters. Many of the craters appear to have a black center encircled by a brown halo. The cover appears to be stretched more than in the prelaunch photograph with the locations of Velcro attach pads showing as oblong indentations in the thermal cover.

  19. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E02

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E02 EL-1994-00385 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E02 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC prior to removal of the experiment tray from the LDEF. The white paint dot on the experiment tray clamp blocks located at the center of the trays lower and left flanges and at the right end of the trays upper flange appear to be discolored by a brown stain. The experiment tray flanges also appear to be coated but with a lighter colored stain. 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 experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be specular and intact with no apparent damage. It appears less taut than in the flight photograph. The uniformly located oval spots on the thermal cover are areas where Velcro pads attach the thermal cover to the support frame and appear more visible than in the prelaunch photograph. The scallop effect around the cover edges occurs between the cover attach points and shows the upper edge of the support frame. The ground strap appears to be in place with no visible damage but is a darker color.

  20. LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B05

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B05 EL-1994-00088 LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B05 The flight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) 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 block of the experiment trays lower flange appears to be discolored by a dark brown stain. The tray flanges also appear to be discolored but with a lighter stain. 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 upper flange is a copper coated pressure sensitive tape used to provide an electrical ground between the experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be intact with no apparent damage but is stretched more taut than in the prelaunch photograph. The glossy black appearance of the thermal cover is apparently due to lighting conditions and not a change in the material optical properties. The bright spots on the dark thermal cover background are areas where Velcro pads are bonded to the back- side of the cover. The scalloped edge effect across the top, bottom and left side of the cover occurs between attach points. The ground strap appears to be in place with no visible damage.

  1. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04 EL-1994-00272 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC after the experiment tray was removed from the LDEF and the silvered TEFLON® thermal cover removed. 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. A copper coated pressure sensitive tape was used to provide an electrical ground strap between the thermal cover and the LDEF structure. All experiment hardware appears to be in prelaunch condition and securely in place. The three cylindrical pressure vessels containing the experiment detectors are shown mounted in the experiment tray with the frame for mounting the thermal cover in the foreground. The white rectangles on the frame are Velcro pads bonded to the frame for attaching the thermal cover and appear in excellent condition. The top half of the cylinders and the thermal cover frame were painted black to meet thermal control requirements.

  2. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A10

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A10 EL-1994-00122 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A10 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in the Orbiter Processing Facility (OPF) at KSC during removal of the LDEF from the Orbiters cargo bay. 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 upper flange is a copper coated pressure sensitive tape used to provide an electrical ground between the experiments thermal cover and the LDEF structure. The UHCRE thermal covers surface appears to have changed from specular to opaque (glossy white) with many black dots of various sizes that appear to be impact craters. An impact crater with a large area of discoloration is clearly visible in the upper right quadrant of the thermal cover. The dark discoloration is probably the results of an impact penetration of the 5 mil TEFLON® film allowing atomic oxygen to oxidize and erode the vapor deposited silver layer beneath. White dots of varying sizes can be seen on the cover, many appear to be encircling impact craters. The cover is not stretched as taut as in the flight photograph and locations of Velcro attach pads are not as prominent. The ground strap appears to be in place with no visible damage but appears to be a deeper copper color.

  3. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B05

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B05 EL-1994-00184 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B05 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC prior to removal of the experiment tray from the LDEF. The paint dots on the experiment tray clamp blocks, originally white, appears to be discolored by a brown stain. The experiment tray flanges also appear to be coated but with a lighter colored stain. 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 experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be specular and intact with no apparent damage. The cover appears less taut than in the flight photograph and the locations of Velcro attach pads are not as prominent. The scallop effect around the cover edges occurs between the cover attach points and shows the upper edge of the support frame. The ground strap appears to be in place with no visible damage.

  4. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray F04

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray F04 EL-1994-00171 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray F04 The postflight photograph was taken in the SAEF II at KSC after the experiment was removed from the LDEF. 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 experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be specular and intact. The circular damaged locations that appeared to to be impact points in the flight photograph are not as apparent in the reflections and is less taut cover. The wrinkled spots on the thermal cover are areas where Velcro pads are bonded to the backside of the cover. The scalloped effect around the cover edges occurs between the cover attach points. The ground strap appears to be in place with no visible damage, but it appears darker.

  5. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C06

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C06 EL-1994-00206 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C06 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 clearly visible on the 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 upper flange is a copper coated pressure sensitive tape used to provide an electrical ground between the experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be specular and intact with no apparent damage. The greenish colors on the left one third of the thermal cover are reflections from the surroundings. The ground strap appears to be in place with no visible damage but appears to be a deeper copper color than in the prelaunch photograph..

  6. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A02

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A02 EL-1994-00387 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A02 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC prior to removal of the experiment tray from the LDEF. The white paint dot on the experiment tray clamp blocks located at the center of the trays upper and right flanges and at the left end of the trays lower flange appear to be discolored by a brown stain. The experiment tray flanges also appear to be coated but with a lighter colored stain. 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 with 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 experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be specular and intact with no apparent damage. It appears less taut than in the flight photograph. The uniformly located oval spots on the thermal cover are areas where Velcro pads attach the thermal cover to the support frame and appear more visible than in the prelaunch photograph. The scallop effect around the cover edges occurs between the cover attach points and shows the upper edge of the support frame. The ground strap appears to be in place with no visible damage but is a darker color.

  7. LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04 EL-1994-00089 LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A04 The flight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) 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 left flange and lower flange appear to be discolored by a dark brown stain. 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 upper flange is a copper coated pressure sensitive tape used to provide an electrical ground between the experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be specular and intact with no apparent damage but is more taut than in the prelaunch photograph. The wrinkled spots on the thermal cover are areas where Velcro pads are bonded to the backside of the cover. The scalloped effect around the cover edges occurs between the cover attach points. The ground strap appears to be in place with no visible damage.

  8. LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E02

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E02 EL-1994-00131 LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E02 The flight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) 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 left flange and lower flange appear to be slightly discolored. 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 experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be intact with out visible damage but more taut than in the prelaunch photograph. The wrinkled spots on the thermal cover are over areas where Velcro pads are bonded to the backside of the cover. The waffle discoloration along the right edge appears to be from preflight processing and not from the space environment. The rippled effect around the cover edges occurs between the cover attach points.

  9. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C05

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C05 EL-1994-00205 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C05 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 that provides outlines of the experiment tray clamp blocks that 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 experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be specular and intact with no apparent damage. The cover appears less taut than in the flight photograph and the locations of Velcro attach pads are less prominent. The greenish colors on the left one third of the thermal cover are reflections from the surroundings. The scallop effect around the cover edges occurs between the cover attach points and shows the upper edge of the support frame. The ground strap appears to be in place with no visible damage but appears to be a deeper copper color than in the prelaunch photograph..

  10. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E10

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E10 EL-1994-00162 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray E10 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in the Orbiter Processing Facility during removal of the LDEF from the Orbiter's payload bay. 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 experiments thermal cover and the LDEF structure. The UHCRE thermal covers surface appears to have changed from specular to opaque with numerous black dots of various sizes that appear to be impact craters. Many of the craters appear to have a black center encircled by a brown halo. Other circular discolorations also appear on the cover surface. The darker discolorations probably result from an impact that penetrates the 5 mil TEFLON® film and allows atomic oxygen to oxidize and/or erode the vapor deposited silver layer beneath. The cover is taut and the locations of Velcro attach pads are prominent. The pinkish green tint on the thermal cover is caused by the lighting and reflections from the surroundings.The ground strap appears to be intact with no visible damage but appears to be a deeper copper color.

  11. A proposed adhesin AoMad1 helps nematode-trapping fungus Arthrobotrys oligospora recognizing host signals for life-style switching.

    PubMed

    Liang, Lianming; Shen, Renfei; Mo, Yuanyuan; Yang, Jinkui; Ji, Xinglai; Zhang, Ke-Qin

    2015-08-01

    The nematode-trapping fungus Arthrobotrys oligospora is an important natural enemy of nematodes. It can capture nematodes by producing a special mycelial structure called adhesive network or trap. The trap is also a signature of the fungus switching from the saprophytic lifestyle to the predacious lifestyle. At present, little is known about the mechanism of lifestyle switch in nematode-trapping fungi. Here we describe the effect of a cell wall protein called AoMad1 on lifestyle switch. The disruption of the AoMad1-encoding gene in A. oligospora resulted in the formation of more traps in the presence of nematodes. Interestingly, the mutant strain was more sensitive to certain nitrogen sources as trap inducers than the wild type strain. The microscopic examinations revealed that the AoMad1-deletion mutant lacked cell surface adhesive materials and the cell wall structures were more porous than wild-type strains. A great of genes were differentially expressed by transcriptomic analysis when trap formation was induced by sodium nitrate compared to the wild type strain, many of them were related to nitrogen metabolism, host-pathogen interaction and mycelia development. The results suggest that AoMad1 plays an important role in life style switching in A. oligospora. PMID:25724687

  12. 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

  13. Sea-level history of past interglacial periods from uranium-series dating of corals, Curaçao, Leeward Antilles islands

    NASA Astrophysics Data System (ADS)

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

    2012-09-01

    Curaçao has reef terraces with the potential to provide sea-level histories of interglacial periods. Ages of the Hato (upper) unit of the "Lower Terrace" indicate that this reef dates to the last interglacial period, 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 interglacial period was a time of significant warmth, on a par with the present interglacial period. 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.

  14. 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…

  15. 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.

  16. A spectroscopic search for colliding stellar winds in O-type close binary systems. I - AO Cassiopeiae

    NASA Technical Reports Server (NTRS)

    Gies, Douglas R.; Wiggs, Michael S.

    1991-01-01

    AO Cas, a short-period, double-lined spectroscopic binary, is studied as part of a search for spectroscopic evidence of colliding stellar winds in binary systems of O-type stars. High S/N ratio spectra of the H-alpha and He I 6678-A line profiles are presented, and their orbital-phase-related variations are examined in order to derive the location and motions of high-density circumstellar gas in the system. These profile variations are compared with those observed in the UV stellar wind lines in IUE archival spectra. IUE spectra are also used to derive a system mass ratio by constructing cross-correlation functions of a single-lined phase spectrum with each of the other spectra. The resulting mass ratio is consistent with the rotational line broadening of the primary star, if the primary is rotating synchronously with the binary system. The best-fit models were found to have an inclination of 61.1 deg + or - 3.0 deg and have a primary which is close to filling its critical Roche lobe.

  17. A Keck/AO deep luminosity function of the Galactic Bulge in Baade's Window obtained using the NIRC2 camera

    NASA Astrophysics Data System (ADS)

    Barczys, M.; Rich, R. M.; Larkin, J.; Matthews, K.; Althouse, W. E.; Campbell, R. D.; Conrad, A.; Egami, E.; Goodrich, R. W.; Honey, A.; Lin, S.; McLean, I. S.; Le Mignant, D.; Neugebauer, G.; Sawicki, M.; Soifer, B. T.; Spencer, M.; Thompson, D. M.; Wizinowich, P.

    2001-12-01

    We report analysis of deep, diffraction-limited infrared H and K band images of the Galactic bulge field of Baade's Window (l,b =1, -4o) obtained using the Keck II telescope and the newly commissioned NIRC2 camera. AO correction using a natural guide star was achieved using a bright V=7 mag foreground star. The field is well corrected over a radius of ~ 20'' and we are easily avoiding the confusion limit; all of the detected images are well resolved. We reach a limiting magnitude near H=23, corresponding to MH=+9 which is within 1-2 mag of the end of the hydrogen burning main sequence, and reaching to stellar masses in the range of 0.15 Msun. We compare our photometry with deep images obtained by NICMOS on board HST and confirm that the luminosity function is continuing to rise at the faint end just as was found in the HST data. The large numbers of low mass stars suggest that they, rather than a large population of brown dwarfs are the lenses responsible for the majority of microlensing events observed toward the Galactic bulge.

  18. [Combination of the Ilizarov ring fixator with the unilateral AO tube fixator. Initial clinical experiences with the hybrid system].

    PubMed

    Raschke, M J; Hoffmann, R; Khodadadyan, C; von Fournier, C; Südkamp, N P; Haas, N P

    1995-12-01

    Ring fixation of the tibia is difficult because of soft tissue transfixation and the size and weight of the external fixator. To increase the patients comfort K-wire and half-pin fixation are combined in a new hybrid configuration. The Ilizarov ring fixator with K-wire or Schanz screw fixation is combined with the unilateral AO fixator. This configuration has so far been used in 17 cases: in the proximal and intraarticular tibia in 7 cases, in the distal tibia in 8 cases and in the femur in 2 cases. As experience with the hybrid system widens indications accepted are metaphyseal and intraarticular fractures of the tibia with severe soft tissue damage, open fractures, segmental defects and fractures of the tibia that cannot be nailed. Loosening of the hybrid construction requiring an additional operative procedure has not occurred. The hybrid system is minimally invasive and allows early weight-bearing. It has the advantages of less transfixation of the soft tissue, an easy operative technique and more comfort with higher patient compliance, and the options for corrective procedures are the same as with the conventional Ilizarov technique. Our preliminary first experience with this system is encouraging; it is especially useful for problematic epi- and metaphyseal fractures with severe soft tissue damage. PMID:8584944

  19. Weighing black holes using open-loop focus corrections for LGS-AO observations of galaxy nuclei at Gemini Observatory

    NASA Astrophysics Data System (ADS)

    McDermid, Richard M.; Krajnovic, Davor; Cappellari, Michele; Trujillo, Chadwick; Christou, Julian; Davies, Roger L.

    2010-07-01

    We present observations of early-type galaxies with laser guide star adaptive optics (LGS AO) obtained at Gemini North telescope using the NIFS integral field unit (IFU). We employ an innovative technique where the focus compensation due to the changing distance to the sodium layer is made 'open loop', allowing the extended galaxy nucleus to be used only for tip-tilt correction. The purpose of these observations is to determine high spatial resolution stellar kinematics within the nuclei of these galaxies to determine the masses of the super-massive black holes. The resulting data have spatial resolution of 0.2" FWHM or better. This is sufficient to positively constrain the presence of the central black hole in even low-mass early-type galaxies, suggesting that larger samples of such objects could be observed with this technique in the future. The open-loop focus correction technique is a supported queue-observing mode at Gemini, significantly extending the sky coverage in particular for faint, extended guide sources. We also provide preliminary results from tests combining tip/tilt correction from the Gemini peripheral guider with on-axis LGS. The current test system demonstrates feasibility of this mode, providing about a factor 2-3 improvement over natural seeing. With planned upgrades to the peripheral wave-front sensor, we hope to provide close to 100% sky coverage with low Strehl corrections, or 'improved seeing', significantly increasing flux concentration for deep field and extended object studies.

  20. 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.

  1. 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.

  2. 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 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. 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 can be seen on the left and lower flanges of the experiment tray and a darker stain has discolored the originally white paint dots on the experiment tray clamp blocks. Dark brown stains on the LDEF structure are vis- ible in areas adjacent to the edge of thermal end panels that were designed to facilitate venting of the LDEF interior. The SBR Phased-Array Antenna experiment, consisting of an active part in the left half of the tray and a passive part located in the right half of the experiment tray, appears to be intact with no apparent physical damage. The black thermal coating on the passive part of the experiment appears unchanged while the black thermal coating on the active part of the experiment appears dark gray. The passive experiment Kapton specimen surfaces appear to have changed from specular to diffuse after exposure to the space environment.

  3. LDEF (Flight), AO133 : Effect of Space Environment on Space-Based Radar Phased-Array Antenna, Tray H

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO133 : Effect of Space Environment on Space-Based Radar Phased-Array Antenna, Tray H07 The flight photograph was taken from the Orbiter aft flight deck during the LDEF retrieval. 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 shadow cast by the Orbiter covers most of the right half of the tray containing the active part of the experiment. Even in the shadow, a light tan discoloration can be seen on the left and lower flanges of the experiment tray and a darker stain has discolored the originally white paint dots on the experiment tray clamp blocks. Dark brown stains on the LDEF structure are visible in areas adjacent to the edge of thermal end panels designed to facilitate venting of the LDEF interior. The SBR Phased-Array Antenna experiment, consisting of an active part in the left half of the tray and a passive part located in the right half of the experiment tray, appears to be intact with no apparent physical damage. The black thermal coating on the passive part of the experiment appears unchanged while the black thermal coating on the active part of the experiment appears a dark gray. The passive experiment Kapton specimen surfaces appear to have changed from specular to diffuse when exposed to the space environment.

  4. LDEF (Prelaunch), AO175 : Evaluation of Long-Duration Exposure to the Natural Space Environment on G

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), AO175 : Evaluation of Long-Duration Exposure to the Natural Space Environment on Graphite-Polyimide and Graphite-Epoxy Mechanical Properties, Tray A01 The Graphite-Polyimide and Graphite-Epoxy Mechanical Properties experiment is located in two (2) three (3) inch deep peripheral trays, A01 and A07. The experiment hardware configuration in the A01 tray consists of a graph- ite-epoxy honeycomb sandwich panel in the lower one half (1/2) of the tray, a graphite-epoxy panel in the upper right one third (1/3rd) section and two (2) graphite-polyimide panels, one in the upper center and one in the upper left sections of the experiment tray. The panels are supported by a substructure and held in place with aluminum strips and non-magnetic stainless steel fasteners. The mounting system, designed to allow for differential thermal expansion, minimizes the risk of inducing high stresses into the test panels.

  5. 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.; Jhannesson, G.; Johnson, A. S.; Katagiri, H.; Kataoka, J.; Kndlseder, 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.; Rain, S.; Rando, R.; Rastawicki, D.; Razzano, M.; Readhead, A.; Reimer, A.; Reimer, O.; Reyes, L. C.; Richards, J. L.; Sbarra, C.; Sgr, 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.; Bentez, 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.; Forn, E.; Gurwell, M. A.; Heidt, J.; Hiriart, D.; Jordan, B.; Kimeridze, G.; Konstantinova, T. S.; Kopatskaya, E. N.; Koptelova, E.; Kurtanidze, O. M.; Lhteenmki, 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.; Sillanp, 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 ?-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 ?-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.

  6. [Clinical results of primary intramedullary osteosynthesis with the unreamed AO/ASIF tibial intramedullary nail of open tibial shaft fractures].

    PubMed

    Mller, C A; Dietrich, M; Morakis, P; Pfister, U

    1998-11-01

    From 04/91 to 06/96 sixty-nine open fractures of the tibia were primarily treated on the day of the accident with unreamed nailing (UTN, Synthese). The distributions of fracture type according to the AO classification and of soft tissue injury according to Gustilo were as follows: fracture type: A: 28%, B: 52%, C: 20%; soft tissue injury: I: 30%, II: 28%, IIIA: 12%, IIIB: 12%, IIIC: 6%. Of the 65 fractures assessed 46 (71%) healed within 18 weeks without secondary intervention. There was delayed healing in three fractures requiring secondary conversion to reamed nailing. Eight fractures (12%) developed pseudarthrosis of which five (8%) healed uneventfully. Deep infections was manifest in four fractures (6%). Three of these infections developed after secondary intervention to treat pseudarthrosis. Seven of the eight pseudarthroses and three of the four infections healed eventually. Revision procedures were necessary in 11 patients (17%) to deal with disturbed fracture healing or infection (10 reamed nailing procedures, three cancellous bone grafts, and one of each of the following: sequestrectomy, fibular osteotomy, plate fixation, external fixator, monorail procedure). The results show that the same good infection rates were achieved for the UTN as for the external fixator. The advantages of the UTN are, however, a lesser need for secondary intervention and greater patient comfort. Therefore, we find the UTN to be a good alternative to the external fixator in the treatment of open fractures with severe soft tissue damage. PMID:9865165

  7. 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.

  8. A negative phase shift of the winter AO/NAO due to the recent Arctic sea-ice reduction in late autumn

    NASA Astrophysics Data System (ADS)

    Nakamura, Tetsu; Yamazaki, Koji; Iwamoto, Katsushi; Honda, Meiji; Miyoshi, Yasunobu; Ogawa, Yasunobu; Ukita, Jinro

    2015-04-01

    This paper examines the possible linkage between the recent reduction in Arctic sea-ice extent and the wintertime Arctic Oscillation (AO)/North Atlantic Oscillation (NAO). Observational analyses using the ERA interim reanalysis and merged Hadley/Optimum Interpolation Sea Surface Temperature data reveal that a reduced (increased) sea-ice area in November leads to more negative (positive) phases of the AO and NAO in early and late winter, respectively. We simulate the atmospheric response to observed sea-ice anomalies using a high-top atmospheric general circulation model (AGCM for Earth Simulator, AFES version 4.1). The results from the simulation reveal that the recent Arctic sea-ice reduction results in cold winters in mid-latitude continental regions, which are linked to an anomalous circulation pattern similar to the negative phase of AO/NAO with an increased frequency of large negative AO events by a factor of over two. Associated with this negative AO/NAO phase, cold air advection from the Arctic to the mid-latitudes increases. We found that the stationary Rossby wave response to the sea-ice reduction in the Barents Sea region induces this anomalous circulation. We also found a positive feedback mechanism resulting from the anomalous meridional circulation that cools the mid-latitudes and warms the Arctic, which adds an extra heating to the Arctic air column equivalent to about 60% of the direct surface heat release from the sea-ice reduction. The results from this high-top model experiment also suggested a critical role of the stratosphere in deepening the tropospheric annular mode and modulation of the NAO in mid to late winter through stratosphere-troposphere coupling.

  9. 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 steady diet of hydrogen gas. Such planets should then be quite bright in Halpha accretion emission. The key point is that: instead of a steep drop off in the luminosity of the planet’s atmosphere, the accretion luminosity of these planets will just linearly decrease with decreasing mass. At an accretion rate=6e-10 Msun/yr we find low mass (~1 Mjup) accreting gap planets are much (50-1000x) brighter (for 0-3.4 mag of Halpha extinction) in Halpha than at H band. PROOF-OF_CONCEPT: A 3 hour MagAO observation at Halpha of a transitional disk in April 2013 was made. The resulting deep diffraction-limited images discovered (at 10.5 sigma) an Halpha source that was 295% above the continuum just 0.083” from the star (edge of the inner 10 AU disk gap). We also detected (at 5 sigma) an excellent (though much fainter) ~1 Mjup mass Halpha planet candidate located auspiciously at the outer edge (145 AU) of the gap. If confirmed by our “second epoch” follow-up as common proper motion then this would be the lowest mass (~1 Mjup) planet ever imaged. SURVEY: Scaling off of this exciting success we propose to deeply image (120 min) all 14 nearby (D<250pc), bright (R<11 mag) , not edge-on (i<80 deg) , young (~5 Myr) transitional disks with MagAO simultaneously at Halpha and L’. In addition, we will use BrGamma instead of Halpha for 8 additional fainter (111 Mjup in mass, we integrate across our target list and find that, in the worst case of minimal masses (1+/-0.5 Mjup), and 3.4 mag extinction, at least seven ~1 Mjup planets should be discovered by this survey --meeting all three of our science goals above.

  10. 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 between the experiments thermal cover and the LDEF structure. The UHCRE thermal covers surface appears to have changed from specular to opaque with many black dots of various sizes that appear to be impact craters. Many of the craters appear to have a black center encircled by a brown halo and then by a white halo. Other white circular discolorations also appear on the cover surface. The darker discolorations probably result from an impact that penetrates the 5 mil TEFLON film and allows atomic oxygen to oxidize and/or erode the vapor deposited silver layer beneath. The black feather shaped discoloration in the lower center of the thermal cover did not appear in the flight photograph and appears to be a particle from a degraded experiment that has attached itself to the cover. The cover is not stretched as taut as in the flight photograph and locations of Velcro attach pads are not as prominent. The ground strap appears to be in place with no visible damage but appears to be a deeper copper color.

  11. A classification manager for compositional concept systems exemplarily shown by the AO/ASIF classification of fractures of long bones.

    PubMed

    Schoop, M; Schoop, D; Bernauer, J

    1995-01-01

    Conventional classification and coding systems represent concept systems by strict hierarchical enumeration and are supported by meaningful codes. Compositional classification is a means for representing concept systems by semantic descriptions. Classification is based on the structure of concept descriptions and explicit hierarchical relationships between their constituents. A classification manager will be presented which is based on the BERNWARD model [1]. BERNWARD is a conceptual graphs formalism and allows the constrained composition of concept descriptions by primitive concepts and roles. It stresses the distinction between generic and partitive relations. Concept descriptions can be classified on the basis of structural criteria for subsumption and part-whole relation. The capabilities of the model, compared to the principles of conventional classification and coding systems, will be exemplified by the AO/ASIF classification of fractures of long bones [2]. This classification is based on 2 axes: topography (long bone and segment) and morphology (type, group, subgroup and quality). It consists of the enumeration of all relevant fractures of long bones which are represented by a compositional meaningful code and by a line drawing. In the demonstrated system, the composition of fracture descriptions is supported by lists of terms and by graphics. The interactive selection of concepts from the space of concepts defined by the implemented classifications is supported by combining the following strategies: entering terms, selecting graphics, adding relevant characteristics to a concept selected before, and navigating through various hierarchies e.g.,generic or partitive hierarchies. These strategies are controlled by different types of compositional restrictions which are: role restrictions, hierarchical restrictions, and coordination restrictions. Role restrictions constrain the addition of specializing characteristics to elements of concept descriptions e.g., the possible complexities of fractures are simple, wedge, and multifragmented. Hierarchical restrictions constrain the generic or partitive refinement of concept elements. For example, every long bone can have the segment "proximal metaphyseal," but only tibia/fibula can have the region "malleolar." Coordination restrictions constrain the coordination of concepts e.g., a frontal fracture of the capitellum can affect the trochlea. Therefore, it is allowed to define a frontal fracture of capitellum and trochlea. Medical observations can be documented by association of selected concepts e.g., a fracture of radius and ulna can be associated to the patient Mr. X. The tools implemented for interactive selection of concepts can be used to rescan documented cases. In contrast to common classification systems, a case can be selected by combining different criteria in BERNWARD. It is possible to look for all female patients with a complex fracture of a long bone of the left upper extremity or to look for all bifocal fractures of the forearm with a wedge fracture of the radius. There is no problem to add new knowledge to the classification manager in the form of another classification. A new classification can be built by using elements of old ones e.g., the classification of the human skeleton is also useful for the AO/ASIF classification. Therefore, parts of classifications can be stored on and loaded from the disk by the demonstrated system. he user environment does not have to be changed to document a different area of medicine because of the conceptual representation of medical knowledge in BERNWARD. The user front-end can be used for all classifications e.g., a relational DBMS for Apple Macintosh systems. Some recursive functions are implemented in a linked Prolog system for effective computation of formal relations between concepts. PMID:8591528

  12. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D07

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D07 EL-1994-00207 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D07 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 to be discolored by a light brown stain. An outline of experiment tray clamp block locations is clearly visible on the experiment trays upper flange and to a lesser extent on its lower flange. The 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 experiments thermal cover and the LDEF structure. The UHCRE thermal covers surface appears specular with green and white discolorations associated with photo lights and reflections of the surrounding area. The black and/or brown dots of various sizes appear to be points of impact and penetration of the TEFLON® cover. The impact point discoloration is probably the results of a penetration in the 5 mil TEFLON® film that affected the vapor deposited silver and inconel layers beneath.. The cover is not as taut as in the flight photograph and locations of the Velcro attach pads are not as prominent. The ground strap appears to be intact with no visible damage but appears to be a darker copper color than in the prelaunch photograph.

  13. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B07

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B07 EL-1994-00312 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B07 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 outline of the experiment tray clamp blocks is clearly visible on the upper tray flange and to a lesser extent on the lower flange. The holding fixture hardware covers the clamp block areas on the end flanges. The prelaunch photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC prior to installation of the experiment tray on the LDEF. 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 experiments thermal cover and the LDEF structure. The UHCRE thermal covers surface appears to have changed from specular to opaque with black dots of various sizes that appear to be impact craters. An impact crater with a large area of white discoloration is clearly visible in the upper left quadrant of the thermal cover. The discoloration is probably the results of an impact penetration of the 5 mil TEFLON® film affecting the vapor deposited silver layer beneath. Many dots, black or brown in color and of varying sizes, can be seen on the cover. The cover is not stretched as taut as in the flight photograph and locations of Velcro attach pads are not as prominent. The ground strap appears to be in place with no visible damage but appears to be a deeper copper color than in the prelaunch photograph.

  14. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D01

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D01 EL-1994-00188 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D01 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC prior to removal of the experiment tray from the LDEF. The white paint dot on the experiment tray clamp block located at the center of the trays lower flange appears to be discolored by a brown stain. The experiment trays lower flange also appear to be coated but with a lighter colored stain. The white paint dots on clamp blocks at each end of the trays upper flange appear to be discolored very little. 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 experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears specular and intact with no visible damage. The bright irregular shaped discoloration located above the grounding strap and about one third of the height of the thermal cover from its bottom edge did not appear in the flight photograph and appears to be a piece of material from a degraded experiment that has attached itself to the cover. The cover has numerous white dots visible on its surface that may also be debris from other degraded experiments. The cover is less taut than in the flight photograph but locations of the Velcro attach pads are still easily detected. The scalloped effect around the thermal cover outer edges occurs between the cover attach points. The grounding strap in the center of the experiment tray lower flange appears to be a darker color than in the prelaunch photograph.

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

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C11 EL-1994-00010 LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C11 The flight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) 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 block of the experiment trays left flange and on the clamp blocks located at the upper and lower ends of the experiment trays right flange appear to be in near prelaunch condition. 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 experiments thermal cover and the LDEF structure. The UHCRE thermal covers surface appears to have changed from specular to opaque with many impacts or penetrations of various sizes clearly visible. Two impacts appear larger and appear to have penetrated the TEFLON® cover. One is located at the right edge of the cover at about the vertical midpoint. The other penetration is near the lower edge of the cover about one third of the cover width from the lower left corner. The cover appears to be stretched more than in the prelaunch photograph and the locations of Velcro attach pads are apparent. The ground strap appears to be in place with no visible damage but appears to be a darker color.

  16. LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B07

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B07 EL-1994-00087 LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray B07 The flight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) 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 left flange and lower flange appear to be slightly discolored but the paint dot on the clamp block located at the right end of the upper flange appears to be stained less. 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 experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be intact with no apparent damage but is stretched more taut than in the prelaunch photograph. The dark blue appearance of the thermal cover in this photograph is apparently due to lighting conditions and not a change in the material optical properties. The oblong indentations on the dark thermal cover background are areas where Velcro pads are bonded to the backside of the cover. The thermal covers surface appears to have small brown circular discolorations of various sizes that appear to be impact craters. An impact crater surrounded by a large light blue area of discoloration is clearly visible in the lower right quadrant of the thermal cover. The discoloration is probably the results of an impact crater penetrating the 5 mil TEFLON® film and upsetting the vapor deposited silver layer beneath. The scalloped edge effect along the left side of the thermal cover occurs between attach points. The ground strap appears to be in place with no visible damage but appears to be a deeper copper color than in the prelaunch photograph.

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

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D05 EL-1994-00038 LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D05 The flight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) 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 block of the experiment trays upper flange and on the tray clamp blocks at each end of the trays lower flange appear to be discolored by a brown stain. The experiment tray flanges also appear to be discolored by the stain. 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 experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be intact with no apparent damage but is stretched more taut than in the prelaunch photograph. The glossy blue-black appearance of the thermal cover in this photograph is apparently due to lighting conditions and not a change in the material optical properties. A vertical strip of discoloration, approximately six inches wide and with a grain pattern, extends from top to bottom along the right edge of the thermal cover. The oblong indentations in the thermal cover are in areas where Velcro pads are bonded to the backside of the cover. The irregular shaped discolorations on the cover surface appear to from lighting and reflections. The several white dots and the circular indents in the right center of the cover may be impact locations. The ground strap appears to be in place with no visible damage.

  18. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C08

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C08 EL-1994-00212 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C08 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 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 between the experiments thermal cover and the LDEF structure. The UHCRE thermal covers surface appears to have changed from specular to opaque (glossy white) with many black dots of various sizes that appear to be impact craters. Many of the craters appear to have a black center encircled by a brown halo and then by a white halo. Other white circular discolorations also appear on the cover surface. The darker discolorations are probably the results of an craters penetrating the 5 mil TEFLON® film allowing atomic oxygen to oxidize and/or erode the vapor deposited silver layer beneath. An item of interest is the impact crater in the lower right corner of the cover that has a spray pattern originating from the point of impact. The cover is not stretched as taut as in the flight photograph and locations of Velcro attach pads are not as prominent. The ground strap appears to be in place with no visible damage but appears to be a deeper copper color.

  19. LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D01

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D01 EL-1994-00134 LDEF (Flight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D01 The flight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken while the LDEF was attached to the Orbiter's RMS arm prior to berthing in the Orbiter's cargo bay. The paint dot , originally white, on the experiment tray clamp block located at the center of the trays lower flange appears to be discolored by a brown stain. The experiment trays lower flange also appears to be coated but with a much lighter stain. The paint dots on clamp blocks at each end of the trays upper flange appear to be discolored very little. 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 experiments thermal cover and the LDEF structure. The UHCRE thermal cover appears to be intact with no apparent damage but is stretched more taut than in the prelaunch photograph. The glossy blue appearance of the thermal cover in this photograph is apparently due to lighting conditions and not a change in the material optical properties. The white dots and circular indentations on the cover surface are probable impact locations. The oblong indentations in the thermal cover are indicative of where Velcro pads are bonded to the backside of the cover. The scalloped edge effect around the periphery of the thermal cover occurs between attach points. The ground strap appears to be in place with no visible damage however the color has darkened significantly.

  20. 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 between the experiments thermal cover and the LDEF structure. The UHCRE thermal covers surface appears to have changed from specular to opaque with many black dots of various sizes that appear to be impact craters. Many of the craters appear to have a black center encircled by a brown halo and then by a white halo. Other white circular discolorations also appear on the cover surface. The darker discolorations probably result from an impact that penetrates the 5 mil TEFLON® film and allows atomic oxygen to oxidize and/or erode the vapor deposited silver layer beneath. The black feather shaped discoloration in the lower center of the thermal cover did not appear in the flight photograph and appears to be a particle from a degraded experiment that has attached itself to the cover. The cover is not stretched as taut as in the flight photograph and locations of Velcro attach pads are not as prominent. The ground strap appears to be in place with no visible damage but appears to be a deeper copper color.

  1. LDEF (Prelaunch), AO133 : Effect of Space Environment on Space-Based Radar Phased-Array Antenna, Tra

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), AO133 : Effect of Space Environment on Space-Based Radar Phased-Array Antenna, Tray H07 The prelaunch photograph was taken in SAEF II at KSC prior to installation of the integrated tray on the LDEF. The Space-Based Radar (SBR) Phased-Array Antenna Experiment occupies a six (6) inch deep LDEF end corner tray located on the space end of the LDEF. The SBR Phased-Array Antenna experiment consists of both passive and active parts. The passive part , shown in the left half of the experiment tray, investigates the dimensional stability of Kapton when exposed to induced stresses in the space environment. Continuous and spliced specimen of both plain Kapton (127 um thick) and glass reinforced Kapton (196 um thick) will be exposed for the entire mission. The Kapton specimen array contains eight 2.54-cm-wide specimen and sixteen (16) 1.27-cm-wide specimen. The specimen are stretched over an aluminum roller assembly and utilize a spring loaded mechanism to provide preselected stresses. An aluminum support structure houses two (2) identical set of specimen, one exposed to the total environment and one shadowed. The fasteners are non-magnetic stainless steel and the black surface is a thermal control coating, 3M-Nextel 401-610 (Black Velvet). The active part of the experiment, located in the right half of the tray, investigates the interaction between high voltage and low-Earth-orbit plasma. A fourteen (14) inch wide by twenty eight (28) inch long section of the Grumman SBR Phased-Array antenna consisting of two Kapton antenna planes and a perforated aluminum ground plane mounted on an aluminum support structure. Cop- per dipole elements deposited on the Kapton antenna plane provide the high voltage electrodes. The fasteners are non-magnetic stainless steel and the black surface is a thermal control coating, 3M-Nextel 401-610 (Black Velvet).

  2. 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.

  3. Color changes in the red-green plates of the 50-year-old AO HRR color vision test.

    PubMed

    Lee, David Y

    2006-01-01

    The original AO HRR color vision test has been considered by many as one of the best plate tests. It is still accepted by many governmental agencies for color vision certification. In their 1954 publication, Hardy, Rand, and Rittler stated that specially compounded inks were used for printing to avoid color changes with time. Fifty years later, it is both important and interesting to determine whether the wear and tear cause significant color changes. The chance finding of a never-used second edition offers an opportunity to evaluate the color changes. A GretagMacbeth Spectrolino spectrophotometer was used to measure the chromaticities of the never-used book, and an extensively used book. Four plates (#4, 7, 13, 16), selected randomly from the four red-green sections, were analyzed. The colored dots from each of the eight plates were plotted on a CIE chromaticity diagram. Isocolor lines were drawn to evaluate chromatic alignment. Chromaticities for plates #4 and 7 are significantly different between the two books. With regard to alignment with isocolor lines, the extensively used book is better than the never-used book for plate #4. There is significant misalignment on plate #7 for both books. Chromaticities for plates #13 and 16 are essentially identical between books, all with good alignment with isocolor lines. The overall comparison shows that the chromatic alignment characteristics of the extensively used book are not worse than the never-used book. Since colors in these plates have to be aligned with both the protan and deutan axes, any significant color changes would have disturbed this delicate requirement. The findings of many plates with good alignment, and the lack of differences on plates #13 and 16 between books, suggest that there are no significant color changes over time. Differences between books on plates #4 and 7 were likely the result of the original printing process. PMID:16962013

  4. 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.

  5. Laser Tomographic AO system for an Integral Field Spectrograph on the E-ELT : the ATLAS project

    NASA Astrophysics Data System (ADS)

    Fusco, Thierry; Meimon, Serge; Thatte, N.; Shnetler, H.; Clénet, Yann; Cohen, M.; Paufique, J.; Ammans, J. P.; Clarke, F.; Dournaux, J. L.; Ferrari, M.; Gratadour, D.; Hubin, N.; Jagourel, P.; Michau, V.; Petit, C.; Tecza, M.

    2011-09-01

    ATLAS (Advanced Tomography with Laser for AO system) is the LTAO module of the E-ELT. It should be combined with an Integral Field Spectrograph (HARMONI). It aims at providing a diffraction limited PSF (SR around 50% in K band) in a small scientific FoV for a very significant part of the sky (more than 60% of the whole sky). 6 Laser Guide Stars (located on a 4.3 arcmin ring) will be used together with 2 Natural Guide Stars to be picked off in a 2 arcmin FoV. A MMSE-based RTC algorithm will be considered to obtain an optimal tomographic reconstruction of the turbulent volume and correct for Laser defects (cone effects). A first concept of the module combined with opto-mechanical implementation and associated performance has been proposed in the frame of the E-ELT instrumentation phase A study. Further modifications and optimisations have been proposed to account for IFS-HARMONI specificities. In this presentation, the main ATLAS components are described and their specificities and innovation highlighted. In particular, a new concept for the natural guide star wavefront sensor (based on a focal plane measurement scheme) is proposed providing extremely good sky coverage. In addition, the impact of Cn^2 mis-calibrations is analyzed and solutions to mitigate this error are proposed. In addition, the specific HARMONI requirements are presented as well as their impacts on ATLAS design, calibration procedures and operational concept. An integrated approach for a common implementation of ATLAS-HARMONI is presented. Results show the feasibility of the concept, its versatility and a relative simplicity which is a good first step toward a potential implementation in the early years of the E-ELT.

  6. Effect of temperature downshifts on a bench-scale hybrid A/O system: Process performance and microbial community dynamics.

    PubMed

    Zhou, Hexi; Li, Xiangkun; Chu, Zhaorui; Zhang, Jie

    2016-06-01

    Effect of temperature downshifts on process performance and bacterial community dynamics was investigated in a bench-scale hybrid A/O system treating real domestic wastewater. Results showed that the average COD removal in this system reached 90.5%, 89.1% and 90.3% for Run 1 (25 °C), Run 2 (15 °C) and Run 3 (10 °C), respectively, and variations in temperature barely affected the effluent COD concentration. The average removal efficiencies of NH4(+)-N were 98.4%, 97.8%, 95.7%, and that of TN were 77.1%, 61.8%, 72% at 25 °C, 15 °C and 10 °C, respectively. Although the hybrid system was subjected to low temperature, this process effectively removed NH4(+)-N and TN even at 10 °C with the average effluent concentrations of 2.4 mg/L and 14.3 mg/L, respectively. Results from high-throughput sequencing analysis revealed that when the operation temperature decreased from 25 °C to 10 °C, the richness and diversity indexes of the system decreased in the sludge samples, while underwent an increase in the biofilm samples. Furthermore, the major heterotrophic bacteria consisted of Lewinella, Lutimonas, Chitinophaga and Fluviicola at 10 °C, which could be central to effective COD removal at low temperature. Additionally, Azospira, one denitrifying-related genus increased from 0.4% to 4.45% in the biofilm samples, with a stable TN removal in response to temperature downshifts. Nitrosomonas and Nitrospira increased significantly in the biofilm samples, implying that the attached biofilm contributed to more nitrification at low temperature. PMID:27035388

  7. Climate change in the 21st century simulated by HadGEM2-AO under representative concentration pathways

    NASA Astrophysics Data System (ADS)

    Baek, Hee-Jeong; Lee, Johan; Lee, Hyo-Shin; Hyun, Yu-Kyung; Cho, ChunHo; Kwon, Won-Tae; Marzin, Charline; Gan, Sun-Yeong; Kim, Min-Ji; Choi, Da-Hee; Lee, Jonghwa; Lee, Jaeho; Boo, Kyung-On; Kang, Hyun-Suk; Byun, Young-Hwa

    2013-11-01

    We present climate responses of Representative Concentration Pathways (RCPs) using the coupled climate model HadGEM2-AO for the Coupled Model Intercomparison Project phase 5 (CMIP5). The RCPs are selected as standard scenarios for the IPCC Fifth Assessment Report and these scenarios include time paths for emissions and concentrations of greenhouse gas and aerosols and land-use/land cover. The global average warming and precipitation increases for the last 20 years of the 21st century relative to the period 1986-2005 are +1.1°C/+2.1% for RCP2.6, +2.4°C/+4.0% for RCP4.5, +2.5°C/+3.3% for RCP6.0 and +4.1°C/+4.6% for RCP8.5, respectively. The climate response on RCP 2.6 scenario meets the UN Copenhagen Accord to limit global warming within two degrees at the end of 21st century, the mitigation effect is about 3°C between RCP2.6 and RCP8.5. The projected precipitation changes over the 21st century are expected to increase in tropical regions and at high latitudes, and decrease in subtropical regions associated with projected poleward expansions of the Hadley cell. Total soil moisture change is projected to decrease in northern hemisphere high latitudes and increase in central Africa and Asia whereas near-surface soil moisture tends to decrease in most areas according to the warming and evaporation increase. The trend and magnitude of future climate extremes are also projected to increase in proportion to radiative forcing of RCPs. For RCP 8.5, at the end of the summer season the Arctic is projected to be free of sea ice.

  8. 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.

  9. Study of the blazar AO 0235+164 during the multi-wavelength observation period from October 2008 to February 2009

    NASA Astrophysics Data System (ADS)

    Rain, S.; Madejski, G.; do Couto e Silva, E.; Gargano, F.; Reyes, L.; Nalewajko, K.; Sikora, M.

    2013-06-01

    AO 0235+164 is one of the most studied and monitored BL Lac objects in the sky. Since the launch of Fermi, the source has been monitored in the gamma-ray band by Fermi Large Area Telescope. Starting in October 2008, AO 0235+164 showed an increasing activity in gamma-rays that led to a multi-wavelength campaign with instruments in the radio, near-infrared, optical, UV and X-ray bands. We present here the results of the analysis of the multi-wavelength data collected during the flaring period: the high variability properties of this source and the SED built from radio frequencies to gamma-rays are shown, and are interpreted in the context of well-known blazar emission models [Ackermann, M. et al. 2012, ApJ 751, 159].

  10. Site symmetry of AO{sub 4} complexes (A are s- or p-elements of periods III and IV) in crystal structures

    SciTech Connect

    Serezhkin, V. N. Savchenkov, A. V.; Urusov, V. S.

    2010-03-15

    The symmetry of the sites occupied in crystal structures by 17 405 crystallographically different A atoms (A are s or p elements of periods III and IV) entering the composition of AO{sub 4}{sup z-} complexes has been analyzed. A periodicity in the ability of A atoms for implementing a certain site symmetry is established. Some features of the stereochemistry of A elements in the dependence of their position in the periodic table are discussed.

  11. 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 have residues dominated by Al and one dominated by Ti, indicating a preponderance of orbital debris in leading edge impacts.

  12. 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.

  13. LDEF (Prelaunch), AO175 : Evaluation of Long-Duration Exposure to the Natural Space Environment on G

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), AO175 : Evaluation of Long-Duration Exposure to the Natural Space Environment on Graphite-Polyimide and Graphite-Epoxy Mechanical Properties, Tray A07 The Graphite-Polyimide and Graphite-Epoxy Mechanical Properties experiment fills two (2) three (3) inch deep peripheral trays, A01 and A07. The experiment in the A07 experiment tray, shown in this photograph, consist of three (3) Graphite-Polyimide laminate panels and associated mounting hardware. Each panel occupies one third (1/3) of the LDEF experiment tray; a PMR-15 precured graphite-polyimide panel (T40T30060-009) in the right one third section, a F-178/T300 cocured graphite-polyimide panel (T40T30060-005) in the center one third section and a F-178/T300 precured graphite-polyimide panel (T40T30060-001) is in the left one third section of the tray. The panels are held in place with aluminum strips and non-magnetic stainless steel fasteners. The aluminum strips are covered with a dull gold coating over most of the exposed surface. The coating has been scraped from the aluminum mounting strip near the upper left tray corner. The mounting system, designed to allow for differential thermal expansion, minimizes the risk of inducing high stresses into the test panels. PMR-15 Graphite-Polyimide Panel (precured) - The PMR-15 graphite-polyimide laminated panel (T40T30060-009) is a uniform dark brown with a yellow identification number. The panel has several off-white marks in the lower right corner and light grayish-brown discolorations can be seen behind the identification number and behind the off-white marks. F-178/T300 Graphite-Polyimide Panel (cocured) - The F178/T300 graphite-polyimide laminated panel (T40T30060-005) is also a dark brown with a yellow identification number and small offwhite marks in the lower right corner. F-178/300 Graphite-Polyimide Panel (precured) - The F178/300 graphite-polyimide laminated panel (T40T30060-001) is a dark brown color with a yellow identification number and small offwhite marks in the panels upper left corner. The panel appears to have a lighter brown area along its vertical center that extends from the bottom to the top of the panel.

  14. Time Differential Electrical Resistivity for Water Resource Assessment: A Case Study in Cura‡ao, Netherlands Antilles

    NASA Astrophysics Data System (ADS)

    Coles, D.; Vichabian, Y.; Sogade, J.; Spiertz, P.; Morgan, F. D.

    2003-12-01

    A method of groundwater prospecting is presented that capitalizes on changes in electrical resistivity arising from annual variability in subsurface fluid flow. According to Archie's Law, effective resistivity is a function of pore fluid resistivity, saturation, and porosity. For competent Earth materials, short-term temporal changes in near-surface porosity are negligible because changes in effective pressure are small with respect to the bulk moduli of the materials. Therefore, annual variability in effective resistivity is dependent only on fluid flow via changes in saturation and, to a lesser extent, pore fluid resistivity. Aquifer detection is but the first step; thereafter, it is necessary to estimate permeability, capacity, and, importantly, sustainability. Time differential resistivity is well matched to the task because it detects prospective aquifers and also illuminates their natural hydrodynamics. Explicitly, this method captures an undeveloped aquifer's seasonal volumetric variability, which is important as engineers reconcile monthly demand with monthly supply. The best scenario would be to detect a capacious, intermediate-resistivity (high pore fluid resistivity and high porosity) zone that is invariant from season to season (clays and ore bodies excepted). Less desirable, but still manageable, is the case where a large, porous formation undergoes significant seasonal resistivity variation; it behaves as a subterranean river with little lag-time between meteoric water input and groundwater throughput; carefully timed extraction and storage would be required in this case. A suite of thirty-eight electrical resistivity soundings were collected from the wet and dry seasons at Plantages PortoMari, an ecotourist plantation on the semiarid island of Cura‡ao, N.A. The data were analyzed with special attention paid to wet-to-dry season resistivity ratios. The results suggest two possible courses of action. (1) A hypothetical limestone terrace was detected whose estimated minimum water volume fluctuates between approximately 1200m3 and 2300m3; this terrace may be tapped with several boreholes descending to an elevation of 25m ASL. (2) A shallow subsurface dam and extraction fence (10m BGS) might be installed where the watershed corridor converges onto a flat plain whose surficial lithology is comprised of poorly sorted alluvia atop an impermeable clayey unit. Both extraction scenarios require storage facilities, as neither hydrogeologic setting indicates a persistent aquifer.

  15. Identification of a copper-responsive promoter and development of a copper biosensor in the soil bacterium Achromobacter sp. AO22.

    PubMed

    Ng, Shee Ping; Palombo, Enzo A; Bhave, Mrinal

    2012-05-01

    A number of human activities result in environmental contamination with copper compounds that can cause severe detrimental effects on the ecosystem as well as human health. The physico-chemical methods of metal detection have limitations such as inability to distinguish between total versus bio-available metals and differences in metal uptake in different organisms. The heavy metal resistance-encoding genetic systems of certain bacteria provide critical tools for development of biosensors for these purposes. This study reports a copper biosensor utilizing the cop operon of the heavy metal resistant bacterial isolate, Achromobacter sp. AO22, isolated from a contaminated site in Australia. A section located between the divergently transcribed putative response regulator gene copR and multicopper oxidase gene copA that included a palindromic cop box was identified as a copper-responsive promoter using a lacZ reporter construct, pCOPRP, in E. coli. The expression was found to be enhanced by inclusion of copR. Another engineered strain, AO22(pCOPRP), showed stronger induction, and the lacZ expression in both backgrounds was enhanced significantly (250-400 fold) by copper but minimally by other metals. The construct in Achromobacter sp. AO22 thus has a high potential as biosensor for detecting copper bioavailability (hence potential toxicity) in a soil bacterial background, while the construct in E. coli is ideal for laboratory-based testing. PMID:22806045

  16. 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.

  17. 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.

  18. Characterization of PmfR, the Transcriptional Activator of the pAO1-Borne purU-mabO-folD Operon of Arthrobacter nicotinovorans

    PubMed Central

    Chiribau, Calin B.; Sandu, Cristinel; Igloi, Gabor L.; Brandsch, Roderich

    2005-01-01

    Nicotine catabolism by Arthrobacter nicotinovorans is linked to the presence of the megaplasmid pAO1. Genes involved in this catabolic pathway are arranged on the plasmid into gene modules according to function. During nicotine degradation γ-N-methylaminobutyrate is formed from the pyrrolidine ring of nicotine. Analysis of the pAO1 open reading frames (ORF) resulted in identification of the gene encoding a demethylating γ-N-methylaminobutyrate oxidase (mabO). This gene was shown to form an operon with purU- and folD-like genes. Only in bacteria grown in the presence of nicotine could transcripts of the purU-mabO-folD operon be detected, demonstrating that this operon constitutes part of the pAO1 nicotine regulon. Its transcriptional start site was determined by primer extension analysis. Transcription of the operon was shown to be controlled by a new transcriptional regulator, PmfR, the product of a gene that is transcribed divergently from the purU, mabO, and folD genes. PmfR was purified, and electromobility shift assays and DNase I-nuclease digestion experiments were used to determine that its DNA binding site is located between −48 and −88 nucleotides upstream of the transcriptional start site of the operon. Disruption of pmfR by homologous recombination with a chloramphenicol resistance cassette demonstrated that PmfR acts in vivo as a transcriptional activator. Mutagenesis of the PmfR target DNA suggested that the sequence GTTT-14 bp-AAAC is the core binding site of the regulator upstream of the −35 promoter region of the purU-mabO-folD operon. PMID:15838033

  19. The geochemistry and petrogenesis of the late-Cretaceous picrites and basalts of Curaçao, Netherlands Antilles: a remnant of an oceanic plateau

    NASA Astrophysics Data System (ADS)

    Kerr, A. C.; Tarney, John; Marriner, Giselle F.; Klaver, Gerard T.; Saunders, Andrew D.; Thirlwall, Matthew F.

    1996-06-01

    The island of Curaçao in the southern Caribbean Sea is composed mainly of a thick sequence (>5 km) of pillow lavas, grading upwards from picrites at the base of the exposed section, to basalts nearer the top. Modelling suggests that picrites are related to the basalts by fractional crystallisation. Initial radiogenic isotope ratios of the picrites have a restricted compositional range: ɛNd=+6.1 to +6.6, 87Sr/86Sr=0.70296 0.70319; whereas the basalts display a wider range of compositions: ɛNd=+6.6 to +7.6, 87Sr/86Sr=0.70321 0.70671. This variation in isotope ratios between basalts and picrites may be due to the assimilation of altered oceanic crust (or possibly partial melts of such crust) by a picritic magma along with fractional crystallisation. The relatively narrow range of Nd and Pb isotopic compositions in the Curaçao lavas suggests either that the source region was homogeneous, or that melts from a heterogeneous mantle source were well mixed before eruption. Chondritic to slightly light rare earth element enriched patterns, combined with long-term light rare earth element depletion (positive ɛNd), suggest that the lavas were formed by polybaric melting of spinel lherzolite, with small a contribution from garnet lherzolite melts. High-MgO lavas, the absence of a subduction related chemistry, and the chemical similarity to other oceanic plateaux, suggest a mantle plume origin for the Curaçao lava succession. The Curaçao volcanic sequence is part of an oceanic plateau formed at about 88 90 Ma, fragments of which are dispersed around the Caribbean as well as being obducted onto the western margin of Colombia and Ecuador. The occurrence of high-Mg lavas throughout this Cretaceous Caribbean Colombian igneous province requires anomalously hot mantle (>200° C hotter than ambient upper mantle) over a large part of a putative plume head, which is inconsistent with some mantle plume models.

  20. Dust and Diffuse Interstellar Bands in the z{sub a} = 0.524 Absorption System toward AO 0235+164

    SciTech Connect

    Junkkarinen, V.

    2004-08-06

    The authors present new HST STIS NUV-MAMA and STIS CCD observations of the BL Lac object AO 0235+164 and the intervening damped Ly {alpha} (DLA) line at z{sub {alpha}} = 0.524. The line profile gives N(HI) = 5 {+-} 1 x 10{sup 21} cm{sup -2} and, combined with the H I 21 cm absorption data leads to a spin temperature of Ts = 220 K {+-} 60 K. Those spectra also show a strong, broad feature at the expected position of the 2175 {angstrom} graphitic dust feature at z{sup {alpha}} = 0.524. Assuming a Galactic type dust extinction curve at z{sub {alpha}} = 0.524 gives a dust-to-gas ratio of 0.19 Galactic, but the fit, assuming the underlying, un-reddened spectrum is a single power-law, is poor in the far-UV. A dust-to-gas ratio of 0.19 Galactic is similar to the LMC, but the AO 0235+164 spectrum does not fit the LMC extinction curve, or the SMC extinction curve (which has practically no 2175 {angstrom} feature). A possible interpretation includes dust similar to Galactic, but with less of the small particles that produce the far-UV extinction. The metallicity of the z{sub {alpha}} = 0.524 absorber, estimated from the observed N(HI) and excess X-ray absorption (beyond Galactic) derived from contemporaneous and archival ASCA and ROSAT.

  1. Comparison of Clinical Outcomes of Phalangeal Fracture Treated with Dorsolateral Approach or Post-middle Approach Using AO Mini Titanium Plate.

    PubMed

    Li, Guang; Liu, Shen; Chen, Guoting; Li, Zengchun; Liu, Yangzhou; Sun, Guixin; Lu, Qingyou; Li, Xia; Tan, Jun; Guan, Ming

    2015-12-01

    The aim of this study is to investigate the clinical outcomes of various fixation methods for proximal phalangeal fractures with Arbeitsgemeinschaft für Osteosynthesefragen (AO) mini titanium plate by dorsolateral approach or post-middle approach. Clinical results of 62 fingers of 53 patients with proximal phalangeal fracture were evaluated. For dorsolateral approach, the lateral bundle of the extensor tendon was drawn away to expose the fracture part of the bone. After reduction, the plate was located at the dorsolateral side of the bone. For post-middle approach, the extensor tendon was split to expose the fracture part of the bone. After reduction, the plate was fixed to the proximal phalangeal side of the bone, and the extensor tendon was repaired with 3-0 nonabsorbable silk sutures. We found low overall complication rates in both groups. The mean total active motion (TAM) for the dorsolateral group and post-middle group was 234.60° ± 22.63° and 221.08° ± 25.69°, respectively. There was a statistical significance between the two groups (P = 0.037 < 0.05), indicating that TAM was notably affected by various fixation methods. With AO mini titanium plate, movement in dorsolateral approach group was significantly higher than in post-middle approach group. Dorsolateral approach is an acceptable technique of incision for proximal phalangeal fractures. PMID:26730082

  2. The a subunit of the A1AO ATP synthase of Methanosarcina mazei G1 contains two conserved arginine residues that are crucial for ATP synthesis.

    PubMed

    Gloger, Carolin; Born, Anna-Katharina; Antosch, Martin; Mller, Volker

    2015-01-01

    Like the evolutionary related F1FO ATP synthases and V1VO ATPases, the A1AO ATP synthases from archaea are multisubunit, membrane-bound transport machines that couple ion flow to the synthesis of ATP. Although the subunit composition is known for at least two species, nothing is known so far with respect to the function of individual subunits or amino acid residues. To pave the road for a functional analysis of A1AO ATP synthases, we have cloned the entire operon from Methanosarcina mazei into an expression vector and produced the enzyme in Escherichia coli. Inverted membrane vesicles of the recombinants catalyzed ATP synthesis driven by NADH oxidation as well as artificial driving forces. [Formula: see text] as well as ?pH were used as driving forces which is consistent with the inhibition of NADH-driven ATP synthesis by protonophores. Exchange of the conserved glutamate in subunit c led to a complete loss of ATP synthesis, proving that this residue is essential for H+ translocation. Exchange of two conserved arginine residues in subunit a has different effects on ATP synthesis. The role of these residues in ion translocation is discussed. PMID:25724672

  3. 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 the ejection of B{sub 4} may not occur for many orbits, and B{sub 3} may be stable against ejection in the long-term. This ''ejection'' process of the lowest mass member of a ''mini cluster'' could play a major role in the formation of low-mass stars and brown dwarfs.

  4. 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 como os respectivos períodos encontrados (1h20min e 4h48min). No caso do FO Aqr, ficou evidente, também, a modulação decorrente da rotação da anã branca receptora (21min). O erro estimado é de 0,01 magnitude. Propomos uma maior utilização de telescópios de pequeno porte, como suporte ao ensino (médio e superior) em cidades com poluição luminosa. Escolas e Planetários seriam ambientes propícios para a localização do telescópio. Os critérios adotados na escolha dos objetos e o método observacional empregado são também apresentados.

  5. Prolonged volcanic history for the Curaçao Lava Formation inferred from new 40Ar-39Ar ages and trace phase geochemistry

    NASA Astrophysics Data System (ADS)

    Loewen, M. W.; Duncan, R. A.; Krawl, K.; Kent, A. J.; Sinton, C. W.; Lackey, J.

    2011-12-01

    Popular models have suggested that the Caribbean Large Igneous Province (CLIP) formed from the initial plume head of the Galapagos hotspot. A key exposure of CLIP lavas is the Curaçao Lava Formation (CLF), a 5 km section of lavas and sills on the island of Curaçao. The CLF contains a broad compositional range of submarine lavas from picrite pillows at the base of the identified section to plagioclase-clinopyroxene tholeiitic lavas, hyaloclastites, and poikilitic sills at the top. Despite the regional significance of the CLF to the tectonic interpretation of the CLIP, only whole rock geochemistry and a few 40Ar-39Ar ages exist for Curaçao. These ages suggest formation of the lavas around 89 Ma and the poikilitic sills around 75 Ma. However, Mid-Albian (~110 Ma) fossil ammonites from a single locality of intercalated sediments suggest a considerably older formation for the CLF. This older age of formation has been used to justify alternate formation models for the CLIP to a Galapagos plume initiation. Here we present new 40Ar-39Ar ages for the lavas and sills of the CLF that indicate a younger and more extended volcanic history than previously recognized. We have identified lava sequences from several localities on the island that erupted 62-66 Ma as well as lavas and sills that fall within previously recognized age ranges. The youngest ages are obtained on samples directly adjacent to the Mid-Albian ammonite locality. These results suggest that large portions of the CLF (1) significantly postdate initiation of the CLIP, and (2) may not be compatible with an origin related to the initiation of the Galapagos hotspot. It is important to note, however, that the previous 89 Ma ages from Curaçao lavas are closer to ages from CLIP lavas on Haiti that reach 90-94 Ma and are spatially located near the picrites on Curaçao. These diverse ages also require significant reinterpretation of the CLF as a complex association of lavas potentially spanning 30 million years. Considering this complex history, we have examined both the whole rock geochemistry of the CLF and added major and trace element chemistry for major phases (olivine, clinopyroxene, plagioclase) present throughout the CLF using EMPA and LA-ICP-MS. These include both picritic lavas of up to 28 wt. % MgO and olivine with Fo 82-89. The bulk of the tholeiitic lavas and sills, however, have a more restricted range in MgO from 6-10 wt. % and a broad range of plagioclase compositions. We use trace element chemistry preserved in phenocrysts to help identify changing tectonic signatures over the newly identified ~30 million year history of the CLF.

  6. 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. PMID:23941805

  7. Multi-watt 589-nm Na D II-line generation via frequency doubling of a Raman fiber amplifier: a source for LGS-assisted AO

    NASA Astrophysics Data System (ADS)

    Taylor, L.; Feng, Y.; Bonaccini Calia, D.; Hackenberg, W.

    2006-06-01

    We develop a novel solid state fibre laser system, AFIRE, for the purposes of laser guidestar (LGS) assisted adaptive optics (AO), based on the second harmonic generation (SHG) from a high-power (P 1178 ~25W) CW narrowband (Δυ < 3GHz) Raman fibre amplifier developed by IPF. We present what we believe to be the highest power, narrowband single-pass CW 589nm SHG result reported to date, P 589 ~ 4.2W from P 1178 ~ 19W (ηVIS > 22%). We demonstrate our understanding of the arising absorption-induced thermal effects (namely, dephasing and degradation of the conversion), offer predictions towards higher powers and conversion levels, and show that our current results are essentially pump-power limited. We are confident of the scalability of both the IR and visible parts of our system, to these higher output powers and conversion efficiencies.

  8. An extreme-AO search for giant planets around a white dwarf. VLT/SPHERE performance on a faint target GD 50

    NASA Astrophysics Data System (ADS)

    Xu, S.; Ertel, S.; Wahhaj, Z.; Milli, J.; Scicluna, P.; Bertrang, G. H.-M.

    2015-07-01

    Context. Little is known about the planetary systems around single white dwarfs, although there is strong evidence that they do exist. Aims: We performed a pilot study with the extreme-AO system on the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) on the Very Large Telescopes (VLT) to look for giant planets around a young white dwarf, GD 50. Methods: We were awarded science verification time on the new ESO instrument SPHERE. Observations were made with the InfraRed Dual-band Imager and Spectrograph in classical imaging mode in H band. Results: Despite the faintness of the target (14.2 mag in R band), the AO loop was closed and a strehl of 37% was reached in H band. No objects were detected around GD 50. We achieved a 5-sigma contrast of 6.2, 8.0, and 8.25 mag at 0.̋2, 0.̋4, and 0.̋6 and beyond, respectively. We exclude any substellar objects more massive than 4.0 MJ at 6.2 au, 2.9 MJ at 12.4 au, and 2.8 MJ at 18.6 au and beyond. This rivals the previous upper limit set by Spitzer. We further show that SPHERE is the most promising instrument available to search for close-in substellar objects around nearby white dwarfs. Based on observations made with European Southern Observatory (ESO) telescopes at the La Silla Paranal Observatory under program 60.A-9373(A).Figure 4 is available in electronic form at http://www.aanda.org

  9. 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. PMID:26430591

  10. Near-IR bispectrum speckle interferometry, AO imaging polarimetry, and radiative transfer modeling of the proto-planetary nebula Frosty Leonis

    NASA Astrophysics Data System (ADS)

    Murakawa, K.; Ohnaka, K.; Driebe, T.; Hofmann, K.-H.; Oya, S.; Schertl, D.; Weigelt, G.

    2008-10-01

    Aims: We combined bispectrum speckle interferometry, adaptive optics (AO) imaging polarimetry, and radiative transfer modeling of polarized light to derive various physical properties of the proto-planetary nebula Frosty Leo. Methods: We performed bispectrum K'-band speckle interferometry and H- and K-band imaging polarimetry of Frosty Leo using the ESO 3.6 m telescope and the AO-equipped CIAO instrument of the 8 m Subaru telescope, respectively. Two-dimensional radiative transfer modeling was carried out in order to obtain a quantitative interpretation of our observations. Results: Our diffraction-limited speckle image shows distinct hourglass-shaped, point-symmetric bipolar lobes, an equatorial dust lane, and complex clumpy structures in the lobes. Our polarimetric data display a centro-symmetric polarization vector pattern with P~30-50% in the bipolar lobes and a polarization disk between them. The polarization images also reveal an elongated region with low polarization along a position angle of -45°. The observations suggest that this region has a low dust density and was carved out by a jet-like outflow. Our radiative transfer modeling can simultaneously explain the observed spectral energy distribution, the intensity distribution of the hourglass-shaped lobes, and our polarization images if we use two grain species with sizes of 0.005 ≤ a ≤ 2.0 μm at latitudes between -2° and +2°, and 0.005 ≤ a ≤ 0.7 μm in the bipolar lobes. Assuming a distance of 3 kpc, an expansion velocity of 25 km s-1, and a gas-to-dust mass ratio of 160, we derive a dust mass of the disk of 2.85×10-3 M⊙, a gas mass-loss rate of 8.97×10-3 M⊙ yr-1, and a total envelope mass of 4.23 M⊙.

  11. Volcanic activity of Io observed in December 2001 with the Keck AO system: 2-5μ m sunlit and eclipse observations

    NASA Astrophysics Data System (ADS)

    Marchis, F.; de Pater, I.; Le Mignant, D.; Roe, H.; Fusco, T.; Graham, J. R.; Prange, R.; Macintosh, B.; Keck Science Team

    2002-09-01

    Volcanically active Io remains a mysterious and intriguing moon, despite numerous spacecraft flybys. Groundbased monitoring programs help characterize the time evolution of Io's volcanic activity, such as the frequency, spatial distribution and temperature of hot spots and outbursts. The satellite was observed intensively in December 2001 with the Keck II Adaptive Optics (AO) system and its recently installed near-infrared camera NIRC2. The spatial resolution after applying the MISTRAL myopic deconvolution method (130 km in K band and 200 km in L band) is better than that of the global images from the Galileo/NIMS instrument. A movie produced from 12 pictures taken every 30o in Ionian longitude provides a complete survey of Io's surface during one full rotation. A total of 26 active hot spots were detected in L band (3.8μ m), and approximatively three times more in M band (4.7μ m). One active hot spot is seen in K band (2.2μ m) in the Pele area. While Io is in Jupiter's shadow, it is invisible to the wavefront sensor, but its hot spots are easily visible in the near-infrared. We imaged Io during the 18 Dec. 2001 eclipse using Ganymede (30" from Io, moving relative to Io at 0.5"/min) as a reference source. Although isoplanatic effects limited AO performance, numerous spots are detected at both K' and L'. We will show the results of detailed studies (temperature, emission area, nature) for several of the hot spots. Keck Science team is composed of S. Kwok, P. Amico, R. Campbell, F. Chaffee, A. Conrad, A. Contos, B. Goodrich, G. Hill, D. Sprayberry, P. Stomski, P. Wizinowich (W.M. Keck Observatory). This work has been supported in part by the National Science Foundation Science and Technology Center for Adaptive Optics, managed by the University of California at Santa Cruz under cooperative agreement No. AST-9876783.

  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

    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.

  13. Health Care Usage and Related Costs in Fibular Plating for AO Type 44-B Ankle Fractures in a Belgian University Hospital: An Exploratory Analysis.

    PubMed

    Smeets, Bart; Nijs, Stefaan; Nderlita, Meri; Vandoren, Cindy; Hoekstra, Harm

    2016-01-01

    Open reposition and internal fixation (ORIF) is the reference standard for unstable Arbeitsgemeinschaft für Osteosynthesefragen (AO)-type 44-B ankle fractures. Age, comorbidity, delayed-staged surgery, and length-of-stay (LOS) are all factors that presumably correlate positively with health care costs. We performed an exploratory analysis of the health care costs associated with the treatment of this type of fracture and hypothesized that these costs will be significantly greater for the elderly. A total of 217 patients with an acute AO type 44-B ankle fracture were included. We studied 14 variables, and 5 main cost categories were defined. The health care costs associated with the treatment of ankle fractures in the present study constituted more than one half (53%) of the hospitalization costs, which, in turn, were strongly related to the LOS. Delayed-staged surgery and age were the most important clinical variables driving the total health care costs and LOS (p < .001). The median LOS before ORIF was 6 times greater (12 versus 2 days) for patients treated using a delayed-staged surgery protocol. The cutoff age above which the costs differed significantly was 65 years. Thus, the median total health care costs for the treatment of these fractures were doubled in the older group ($9207 versus $4559), mainly owing to a 2 times greater LOS before ORIF (2 versus 4 days) and 3 times greater total LOS (4 versus 12.5 days) in the elderly. Surprisingly, the complication rate was equal (27.7% versus 29.3%) in the 2 groups. Therefore, to decrease the total health care costs, we should focus on a reduction of the costly LOS before ORIF in the elderly population. PMID:26993827

  14. Collective Mode of Rattling Ions: Origin of Anomalous Lattice Specific Heat of β-Pyrochlores AOs2O6 (A=K, Rb, Cs)

    NASA Astrophysics Data System (ADS)

    Hinokihara, Taichi; Miyake, Kazumasa

    2012-08-01

    The lattice specific heat of AOs2O6 (A=K, Rb, Cs) does not follow the T3 law, but follows an approximate T5 law (precisely speaking, the T4.7 law when A=K) at low temperatures. In order to explain this unusual property, not only the anharmonic and anisotropic potential for the guest ion A, but also the interaction among guest ions plays a crucial role. We adopt a guest ion-dipole interaction as the interaction, after introducing a simplified one-dimensional model for the cage. By extending the method of Pines and Bohm for plasma oscillations, the eigen frequency of the Heisenberg equation of motion for the collective mode is obtained. The dispersion shows anisotropic behavior in the \\mbi{k}-space in such a manner that the gap of the dispersion becomes zero when \\mbi{k} is perpendicular to the direction of the guest ion's motion. Collective modes are quantized by a conventional method, giving rise to the T4 dependence of specific heat. The effect of the local quantized levels of the ion in the cage is simulated using a quantum well-potential model, and the harmonic potential near the bottom of the quantum well. Adding these effects, we obtain the T dependence of the specific heat that can explain the anomalous specific heat behavior fairly well. The effect of screening the collective mode dispersion due to conduction electrons is shown to be almost irrelevant. The difference in T dependence of the specific heat for different A ions in AOs2O6 can also be explained qualitatively by considering the difference in model parameters.

  15. Reconstruction of High Dynamic Range Images: Simulations of LBT Observations of a Stellar Jet, a Pathfinder Study for Future AO-Assisted Giant Telescopes

    NASA Astrophysics Data System (ADS)

    La Camera, A.; Antoniucci, S.; Bertero, M.; Boccacci, P.; Lorenzetti, D.; Nisini, B.; Arcidiacono, C.

    2014-02-01

    We present simulated Large Binocular Telescope (LBT) infrared narrow-band observations of a star-jet system, in conjunction with improved and optimized deconvolution and image reconstruction algorithms, considering two cases of interest: single-dish direct imaging with an AO-assisted camera and imaging through a Fizeau interferometer that combines the beams of the two mirrors of LBT. We aim at understanding what accuracy can be obtained with the use of present AO-assisted large telescopes (such as LBT) and what improvements an interferometric instrument (such as LINC-NIRVANA) will be able to provide. The proposed deconvolution method is based on the target decomposition as a sum of a point source (the star) and an extended source (the jet). By assuming Poisson noise we add to the negative logarithm of the likelihood a regularization term enforcing smoothness of the jet component. Finally, we use a Richardson-Lucy-like method for the minimization of this function. This approach is an improvement of a method proposed by Lucy in 1994 for accurate photometric restoration of HST images and called two channel photometric restoration. We denote the new method as the multi-component Richardson-Lucy (MC-RL) method. The analysis of the reconstructed objects shows that the MC-RL method applied to the interferometric observations allows us to evaluate the width and the spatial intensity profile of the jet down to 20 mas with an accuracy better than about 20% in the best case of a central star fainter than 10 mag. These limits allow us to obtain a very good reconstruction of the jet acceleration region very close to the exciting source, which would provide fundamental scientific information on the jet collimation degree and eventually on its launching mechanism. As concerns the proposed MC-RL method, it demonstrates a good performance in the reconstruction of images with a very high dynamic range. It can be improved in several directions, by increasing both its efficiency, thanks to recently proposed acceleration techniques, and its accuracy by means of more sophisticated regularization terms. We are also planning to apply the method to simulated observations of upcoming super giant earth-based telescopes.

  16. Characteristics of sodium guidestars created by the 50-watt FASOR and first closed-loop AO results at the Starfire Optical Range

    NASA Astrophysics Data System (ADS)

    Denman, Craig A.; Drummond, Jack D.; Eickhoff, Mark L.; Fugate, Robert Q.; Hillman, Paul D.; Novotny, Steven J.; Telle, John M.

    2006-06-01

    A computer-automated cw sodium guidestar FASOR (Frequency Addition Source of Optical Radiation) producing a single frequency 589-nm beam with up to 50 W for mesospheric beacon generation has been integrated with the 3.5-m telescope at the Starfire Optical Range, Kirtland AFB, New Mexico. Radiance tests have produced a peak guidestar V I magnitude = 5.1 (~7000 photons/s/cm2 at zenith) for 30 W of circularly polarized pump power in November 2005. Estimated theoretical maximum guidestar radiance is about 3 times greater than measured values indicating saturation due to atoms possibly becoming trapped in F'=1 and/or atomic recoil. From sky tests over 3.5 years, we have tracked the annual variation of the sodium column density by measuring the return flux as a function of fasor power and determining the slope at zero power. The maximum occurs on October 30 and the minimum on May 30, with corresponding predicted returns of 8000 (V I = 4.8) and 3000 (V I = 5.8) ph/s/cm2 with 50 W of fasor power and circular polarization. The effect of the Earth's magnetic field on the radiance of the sodium laser guidestar (LGS) from various azimuths and elevations has been measured. The peak return flux over our observatory occurs at [az=198 °; el=+71 °], compared with the direction of the magnetic field lines at [190 °; +62 °], and it can vary by a factor of 3 over the sky above el = 30 °. First results for non-optimized sodium LGS adaptive optics (AO) closed-loop operation have been obtained using binary stars. Strehl ratios of 0.03 have been measured at 850 nm and a 0.14 arc second binary star has been resolved during first closed loop observations. Guidestar characteristics, including radiance, size, and Rayleigh backscatter, the sodium LGS wavefront sensor (WFS) AO system, and recent closed-loop results on binary stars are presented.

  17. Superfund explanation of significant difference for the record of decision (EPA region 2): A.O. Polymer, Sparta Township, NJ, September 17, 1996

    SciTech Connect

    1997-03-01

    The Record of Decision (ROD) for the A.O. Polymer Superfund Site (the Site), signed on June 28, 1991, called for the use of a soil vapor extraction system to remove contaminants from the soils that act as the source of groundwater contamination. The groundwater component of the ROD called for extraction of the contaminated groundwater, treatment with a powdered activated carbon treatment (PACT) system, and discharge of the treated water back into the groundwater aquifer. Results from a treatability study performed on the PACT system with groundwater taken from the Site indicate that the effluent from the PACT system exceeds the surface water discharge limitations. In addition, information gathered since the issuance of the ROD has shown that the aquifer does not have sufficient capacity to accept the treatment system effluent without adversely affecting the groundwater plume and surrounding properties. Therefore, the treated groundwater will be discharged to the Wallkill River located 500 feet southeast of the Site. Further, air stripping will be used instead of PACT to remove contaminants from the groundwater.

  18. 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. PMID:26062555

  19. New Extinction and Mass Estimates from Optical Photometry of the Very Low Mass Brown Dwarf Companion CT Chamaeleontis B with the Magellan AO System

    NASA Astrophysics Data System (ADS)

    Wu, Ya-Lin; Close, Laird M.; Males, Jared R.; Barman, Travis S.; Morzinski, Katie M.; Follette, Katherine B.; Bailey, Vanessa; Rodigas, Timothy J.; Hinz, Philip; 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 YS . With our new photometry and T eff ~ 2500 K derived from the shape of its K-band spectrum, we find that CT Cha B has AV = 3.4 ± 1.1 mag, and a mass of 14-24 MJ 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 × 10-10 M ⊙ yr-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', YS ) allows for a better estimate of extinction, luminosity, and mass accretion rate of young substellar companions. This paper includes data gathered with the 6.5 m Magellan Clay Telescope at Las Campanas Observatory, Chile.

  20. Electron spin resonance and radiocarbon dating of coral deposited by Holocene tsunami events on Curaçao, Bonaire and Aruba (Netherlands Antilles)

    NASA Astrophysics Data System (ADS)

    Radtke, Ulrich; Schellmann, Gerhard; Scheffers, Anja; Kelletat, Dieter; Kromer, Bernd; Uwe Kasper, Haino

    2003-05-01

    Electron spin resonance (ESR) dating of coral has become an efficient geochronological tool for studying the last 500,000 years. This study presents results of ESR dating of Holocene coral from Curaçao, Bonaire and Aruba, Leeward Netherlands Antilles. The coral accumulated in rubble ridges and ramparts onshore and the depositional process is attributed to a series of tsunami events. In addition to the calculation of equivalent dose ( DE) values, it is crucial for ESR dating to obtain the correct D0 value for each sample. The annual dose rate ( D0) estimation of the samples in this study is uncertain as the timing of the tsunami event and the residence time of a component of the dated sediment in different environments (marine versus terrestrial) is difficult to quantify. Assuming that the tsunami event deposited coral shortly after death, the ESR and 14C ages of 22 samples reaching from 3650 to 128 years correspond well with each other. This confirms the idea that the living coral reef was partly destroyed by tsunami events. The ESR dating uncertainties coincide with the variability of 14C ages caused by the marine reservoir effect. The local marine reservoir effect was estimated using four recent samples from 1920 and provided values between 375 and 595 yr BP.

  1. Back-thrusting response of continental collision: Early Cretaceous NW-directed thrusting in the Changle-Nan'ao belt (Southeast China)

    NASA Astrophysics Data System (ADS)

    Wei, Wei; Faure, Michel; Chen, Yan; Ji, Wenbin; Lin, Wei; Wang, Qingchen; Yan, Quanren; Hou, Quanlin

    2015-03-01

    The SE coastal area of the South China Block (SCB) is generally interpreted as a Cretaceous active continental margin due to subduction of the Paleo-Pacific plate beneath the Eurasian plate. There, the NE-SW striking Changle-Nan'ao belt was previously considered as a major strike-slip fault zone with a large displacement accommodating the northward subduction of the Paleo-Pacific plate. Our new field and laboratory investigations document a NW-directed ductile thrust zone that placed gneiss upon Early Cretaceous foliated volcanic rocks. Structural analyses and Anisotropy of Magnetic Susceptibility results indicate that the ductile fabrics in both units are represented by a NE-SW striking foliation and a NW-SE stretching lineation with top-to-the-NW shear sense. This deformation occurred at ca. 130-105 Ma, before the deposition of undeformed (ca. 104 Ma) volcanic rocks, and the intrusion of ca. 90 Ma isotropic plutons. This continent-ward structure is tentatively interpreted as a back-thrust resulting of the collision of the West Philippines microcontinent with the SCB rather than an effect of a simple oceanic subduction.

  2. Long-term monitoring of the blazars AO 0235+164 and S5 0716+714 in the optical and radio ranges

    NASA Astrophysics Data System (ADS)

    Bychkova, V. S.; Vol'vach, A. E.; Kardashev, N. S.; Larionov, M. G.; Vlasyuk, V. V.; Spiridonova, O. I.; Vol'vach, L. N.; Lähteenmäki, A.; Tornikoski, M.; Aller, M. F.; Aller, H. D.

    2015-09-01

    Long-term, multi-frequency optical and radio monitoring data for the Active Galactic Nuclei (AGNs) AO 0235+164 and S5 0716+714 are used to derive the characteristics of their radiation on time scales from hours to decades. Structure-function and harmonic analyses are carried out to determine the parameters of the radiation of these AGNs and explain their physical characteristics. Periodic components that could be associated with the motion of companions along an orbit in a close binary system of two supermassive black holes are identified. Both of the analysis methods used yield consistent results for the harmonic components. The results obtained are consistent with the idea that we are viewing systems of two supermassive black holes in a stage of their evolution that is close to coalescence. The substantial energy release of these AGNs can be interpreted as dynamical losses arising during the motion of the companion about the common center of gravity in a dense accreting medium, sometimes crossing through the accretion disk.

  3. 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.

  4. 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.

    1998-01-01

    The first International Symposium on Strain Gauge Balances was sponsored under the auspices of the NASA Langley Research Center (LaRC), Hampton, Virginia. 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 bv 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.

  5. 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.

  6. 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. PMID:23572319

  7. 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).

  8. ON THE LOCATION OF THE {gamma}-RAY OUTBURST EMISSION IN THE BL LACERTAE OBJECT AO 0235+164 THROUGH OBSERVATIONS ACROSS THE ELECTROMAGNETIC SPECTRUM

    SciTech Connect

    Agudo, Ivan; Gomez, Jose L.; Marscher, Alan P.; Jorstad, Svetlana G.; Larionov, Valeri M.; Blinov, Dmitriy A.; Hagen-Thorn, Vladimir A.; Laehteenmaeki, Anne; Smith, Paul S.; Nilsson, Kari; Readhead, Anthony C. S.; Aller, Margo F.; Aller, Hugh D.; Heidt, Jochen; Gurwell, Mark; Thum, Clemens; Wehrle, Ann E.; Nikolashvili, Maria G.; BenItez, Erika; Hiriart, David

    2011-07-01

    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 {lambda} = 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.

  9. 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.

  10. A measurement of the systematic astrometric error in GeMS and the short-term astrometric precision in ShaneAO

    NASA Astrophysics Data System (ADS)

    Ammons, S. M.; Neichel, Benoit; Lu, Jessica; Gavel, Donald T.; Srinath, Srikar; McGurk, Rosalie; Rudy, Alex; Rockosi, Connie; Marois, Christian; Macintosh, Bruce; Savransky, Dmitry; Galicher, Raphael; Bendek, Eduardo; Guyon, Olivier; Marin, Eduardo; Garrel, Vincent; Sivo, Gaetano

    2014-08-01

    We measure the long-term systematic component of the astrometric error in the GeMS MCAO system as a function of field radius and Ks magnitude. The experiment uses two epochs of observations of NGC 1851 separated by one month. The systematic component is estimated for each of three field of view cases (15'' radius, 30'' radius, and full field) and each of three distortion correction schemes: 8 DOF/chip + local distortion correction (LDC), 8 DOF/chip with no LDC, and 4 DOF/chip with no LDC. For bright, unsaturated stars with 13 < Ks < 16, the systematic component is < 0.2, 0.3, and 0.4 mas, respectively, for the 15'' radius, 30'' radius, and full field cases, provided that an 8 DOF/chip distortion correction with LDC (for the full-field case) is used to correct distortions. An 8 DOF/chip distortion-correction model always outperforms a 4 DOF/chip model, at all field positions and magnitudes and for all field-of-view cases, indicating the presence of high-order distortion changes. Given the order of the models needed to correct these distortions (~8 DOF/chip or 32 degrees of freedom total), it is expected that at least 25 stars per square arcminute would be needed to keep systematic errors at less than 0.3 milliarcseconds for multi-year programs. We also estimate the short-term astrometric precision of the newly upgraded Shane AO system with undithered M92 observations. Using a 6-parameter linear transformation to register images, the system delivers ~0.3 mas astrometric error over short-term observations of 2-3 minutes.

  11. Future changes in summer precipitation in regional climate simulations over the Korean peninsula forced by multi-RCP scenarios of HadGEM2-AO

    NASA Astrophysics Data System (ADS)

    Cha, Dong-Hyun; Lee, Dong-Kyou; Jin, Chun-Sil; Kim, Gayoung; Choi, Yonghan; Suh, Myoung-Seok; Ahn, Joong-Bae; Hong, Song-You; Min, Seung-Ki; Park, Seong-Chan; Kang, Hyun-Suk

    2016-05-01

    In this study, the regional climate of the Korean Peninsula (KP) was dynamically downscaled using a high-resolution regional climate model (RCM) forced by multi- representative concentration pathways (RCP) scenarios of HadGEM2-AO, and changes in summer precipitation were investigated. Through the evaluation of the present climate, the RCM reasonably reproduced long-term climatology of summer precipitation over the KP, and captured the sub-seasonal evolution of Changma rain-band. In future projections, all RCP experiments using different RCP radiative forcings (i.e., RCP2.6, RCP4.5, RCP6.0, and RCP8.5 runs) simulated an increased summer precipitation over the KP. However, there were some differences in changing rates of summer precipitation among the RCP experiments. Future increases in summer precipitation were affected by future changes in moisture convergence and surface evaporation. Changing ranges in moisture convergences among RCP experiments were significantly larger than those in surface evaporation. This indicates that the uncertainty of changes in summer precipitation is related to the projection of the monsoon circulation, which determines the moisture convergence field through horizontal advection. Changes in the sub-seasonal evolution of Changma rain-band were inconsistent among RCP experiments. However, all experiments showed that Changma rain-band was enhanced during late June to early July, but it was weakened after mid-July due to the expansion of the western North Pacific subtropical high. These results indicate that precipitation intensity related to Changma rain-band will be increased, but its duration will be reduced in the future.

  12. SPHERE eXtreme AO control scheme: final performance assessment and on sky validation of the first auto-tuned LQG based operational system

    NASA Astrophysics Data System (ADS)

    Petit, C.; Sauvage, J.-F.; Fusco, T.; Sevin, A.; Suarez, M.; Costille, A.; Vigan, A.; Soenke, C.; Perret, D.; Rochat, S.; Barrufolo, A.; Salasnich, B.; Beuzit, J.-L.; Dohlen, K.; Mouillet, D.; Puget, P.; Wildi, F.; Kasper, M.; Conan, J.-M.; Kulcsár, C.; Raynaud, H.-F.

    2014-08-01

    The SPHERE (Spectro-Polarimetry High-contrast Exoplanet Research) instrument is an ESO project aiming at the direct detection of extra-solar planets. SPHERE has been successfully integrated and tested in Europe end 2013 and has been re-integrated at Paranal in Chile early 2014 for a first light at the beginning of May. The heart of the SPHERE instrument is its eXtreme Adaptive Optics (XAO) SAXO (SPHERE AO for eXoplanet Observation) subsystem that provides extremely high correction of turbulence and very accurate stabilization of images for coronagraphic purpose. However, SAXO, as well as the overall instrument, must also provide constant operability overnights, ensuring robustness and autonomy. An original control scheme has been developed to satisfy this challenging dichotomy. It includes in particular both an Optimized Modal Gain Integrator (OMGI) to control the Deformable Mirror (DM) and a Linear Quadratic Gaussian (LQG) control law to manage the tip-tilt (TT) mirror. LQG allows optimal estimation and prediction of turbulent angle of arrival but also of possible vibrations. A specific and unprecedented control scheme has been developed to continuously adapt and optimize LQG control ensuring a constant match to turbulence and vibrations characteristics. SPHERE is thus the first operational system implementing LQG, with automatic adjustment of its models. SAXO has demonstrated performance beyond expectations during tests in Europe, in spite of internal limitations. Very first results have been obtained on sky last May. We thus come back to SAXO control scheme, focusing in particular on the LQG based TT control and the various upgrades that have been made to enhance further the performance ensuring constant operability and robustness. We finally propose performance assessment based on in lab performance and first on sky results and discuss further possible improvements.

  13. 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. PMID:7261698

  14. Magellan Adaptive Optics First-light Observations of the Exoplanet β Pic b. II. 3-5 μm Direct Imaging with MagAO+Clio, and the Empirical Bolometric Luminosity of a Self-luminous Giant Planet

    NASA Astrophysics Data System (ADS)

    Morzinski, Katie M.; Males, Jared R.; Skemer, Andy J.; Close, Laird M.; Hinz, Phil M.; Rodigas, T. J.; Puglisi, Alfio; Esposito, Simone; Riccardi, Armando; Pinna, Enrico; Xompero, Marco; Briguglio, Runa; Bailey, Vanessa P.; Follette, Katherine B.; Kopon, Derek; Weinberger, Alycia J.; Wu, Ya-Lin

    2015-12-01

    Young giant exoplanets are a unique laboratory for understanding cool, low-gravity atmospheres. A quintessential example is the massive extrasolar planet β Pic b, which is 9 AU from and embedded in the debris disk of the young nearby A6V star β Pictoris. We observed the system with first light of the Magellan Adaptive Optics (MagAO) system. In Paper I we presented the first CCD detection of this planet with MagAO+VisAO. Here we present four MagAO+Clio images of β Pic b at 3.1 μm, 3.3 μm, L‧, and {M}\\prime , including the first observation in the fundamental CH4 band. To remove systematic errors from the spectral energy distribution (SED), we re-calibrate the literature photometry and combine it with our own data, for a total of 22 independent measurements at 16 passbands from 0.99 to 4.8 μm. Atmosphere models demonstrate the planet is cloudy but are degenerate in effective temperature and radius. The measured SED now covers >80% of the planet's energy, so we approach the bolometric luminosity empirically. We calculate the luminosity by extending the measured SED with a blackbody and integrating to find log({{L}}{bol}/{{L}}⊙ ) \\=\\-3.78+/- 0.03. From our bolometric luminosity and an age of 23 ± 3 Myr, hot-start evolutionary tracks give a mass of 12.7 ± 0.3 {{M}}{Jup}, radius of 1.45 ± 0.02 {{R}}{Jup}, and Teff of 1708 ± 23 K (model-dependent errors not included). Our empirically determined luminosity is in agreement with values from atmospheric models (typically -3.8 dex), but brighter than values from the field-dwarf bolometric correction (typically -3.9 dex), illustrating the limitations in comparing young exoplanets to old brown dwarfs.

  15. 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 parameter and their limits for setting up a DoE is very important. An extrapolation of results is not recommended because the results are not reliable out of the tested area. (authors)

  16. 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 validity. The FDR has become an indispensable tool for the department for planning and education and will serve as a prerequisite for the conduct and execution of future prospective trials within the department. Further, other departments with similar electronic patient files may fairly easily adopt this system for implementation. PMID:20955572

  17. Constitutive activation of the fucAO operon and silencing of the divergently transcribed fucPIK operon by an IS5 element in Escherichia coli mutants selected for growth on L-1,2-propanediol.

    PubMed Central

    Chen, Y M; Lu, Z; Lin, E C

    1989-01-01

    L-1,2-Propanediol is an irretrievable end product of L-fucose fermentation by Escherichia coli. Selection for increased aerobic growth rate on propanediol results in the escalation of basal synthesis of the NAD+-linked oxidoreductase encoded by fucO, a member of the fuc regulon for the utilization of L-fucose. In general, when fucO becomes constitutively expressed, two other simultaneous changes occur: the fucA gene encoding fuculose-1-phosphate aldolase becomes constitutively expressed and the fucPIK operon encoding fucose permease, fucose isomerase, and fuculose kinase becomes noninducible. In the present study, we show that fucO and fucA form an operon which is divergently transcribed from the adjacent fucPIK operon. In propanediol-positive and fucose-negative mutants the cis-controlling region shared by the operons fucAO and fucPIK is lengthened by 1.2 kilobases. DNA hybridization identified the insertion element to be IS5. This element, always oriented in the same direction with the left end (the BglII end) proximal to fucA, apparently causes constitutive expression of fucAO and noninducibility of fucPIK. The DNA of the fucAO operon and a part of the adjacent fucP was sequenced. Images PMID:2553671

  18. Is the lag screw sliding effective in the intramedullary nailing in A1 and A2 AO-OTA intertrochanteric fractures? A prospective study of Sliding and None-sliding lag screw in Gamma-III nail

    PubMed Central

    2012-01-01

    Object To compare the Sliding with Non-sliding lag screw of a gamma nail in the treatment of A1 and A2 AO-OTA intertrochanteric fractures. Materials and methods 80 patients were prospectively collected. In each group, AO/OTA 31-A were classified into group A. AO/OTA 31-A2.1 was classified as group B. We classified the A2.2 and A2.3 as group C. According to the set-screw locking formation of Gamma-III, the cases were randomly allocated to Sliding subgroup and Non-sliding subgroup in A, B and C groups. Follow-ups were performed 1, 3, 6 and 12 months postoperatively. Results In the Sliding group, the bone healing rate 3, 6, 12 months postoperatively reached 85.00%, 97.50%, 100% in group A, B and C. Meanwhile, in Non-sliding group, postoperatively, bone healing rate were 90.00%, 95.00% and 97.50% in group A, B and C, respectively. Both differences were not significant. Lower limb discrepancy between Sliding and Non-sliding pattern was significantly different in group C which represent fracture types of AO/OTA 31-A2.2 and A2.3 (0.573 ± 0.019 mm in Non-sliding group, 0.955 mm ± 0.024 mm in Sliding group, P < 0.001 ). Difference of sliding distance among the three groups was significant among group A, B and C: 0.48 mm ± 0.04 mm, 0.62 mm ± 0.07 mm and 0.92 mm ± 0.04 mm (P < 0.001). Differences in average healing time and Harris scores also presented no significance in the three groups. Conclusions As a result, we can conclude that the sliding distance is minimal in Gamma nails and it is related to the comminuted extent of the intertrochanteric area in A1 and A2 AO-OTA intertrochanteric fractures. For treating these kinds of fractures, the sliding of the lag screw of an Gamma nail does not improve any clinical results and in certain cases, such as highly comminuted A1 and A2 fractures, can therefore even benefit from a locked lag screw by tightening the set-screw. PMID:22938031

  19. A prediction model for lift-fan simulator performance. M.S. Thesis - Cleveland State Univ.

    NASA Technical Reports Server (NTRS)

    Yuska, J. A.

    1972-01-01

    The performance characteristics of a model VTOL lift-fan simulator installed in a two-dimensional wing are presented. The lift-fan simulator consisted of a 15-inch diameter fan driven by a turbine contained in the fan hub. The performance of the lift-fan simulator was measured in two ways: (1) the calculated momentum thrust of the fan and turbine (total thrust loading), and (2) the axial-force measured on a load cell force balance (axial-force loading). Tests were conducted over a wide range of crossflow velocities, corrected tip speeds, and wing angle of attack. A prediction modeling technique was developed to help in analyzing the performance characteristics of lift-fan simulators. A multiple linear regression analysis technique is presented which calculates prediction model equations for the dependent variables.

  20. Nuclear structure studies at intermediate energy. [School of Physics and Astronomy, Univ. of Minnesota

    SciTech Connect

    Hintz, N.M.; Sethi, A.; Starodubsky, V.; Yang, Xin hua; Franey, M.; Mihaildis, D.

    1992-09-01

    New experimental results are given for proton elastic and inelastic cross sections for [sup 182,186]W at 650 MeV, [sup 208]Pb and [sup 60]Ni(p,t) cross sections at 120 MeV, a coincidence study of the [sup 40]Ca([rvec p],2p) reaction. In addition to the above, data reduction and analysis are also being carried out as follows: global analysis of [sup 28]Si and [sup 58]Ni([rvec p],p[prime]) data at 135, 178, 333, 500, and 800 MeV for high-spin stretched states using medium modified interactions (conventional and QCD effective mass modifications); analysis of [sup 206,207,208]Pb([rvec p],p) elastic data at 650 MeV. Work on development of techniques to study relativistic effects of proton[endash]nucleus scattering at forward angles and extended angular range of S[sub nn] measurements in [sup 40]Ca was also carried out.

  1. Theory of elementary particles and accelerator theory: Task C: Experimental high energy physics. [Univ. of Oregon

    SciTech Connect

    Brau, J.E.

    1992-01-01

    The experimental high energy physics group at the University of Oregon broadened its effort during the past year. The SLD effort extends from maintaining and operating the SLD luminosity monitor which was built at Oregon, to significant responsibility in physics analysis, such as event selection and background analysis for the left-right asymmetry measurement. The OPAL work focussed on the luminosity monitor upgrade to a silicon-tungsten calorimeter. Building on the work done at Oregon for SLD, the tungsten for this upgrade was machined by the Oregon shops and shipped to CERN for assembly. The Oregon GEM effort now concentrates on tracking, specifically silicon tracking. Oregon also has developed a silicon strip preradiator prototype, and tested it in a Brookhaven beam.

  2. 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.

  3. 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.

  4. [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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Condensed matter research using the UCSB FEL. [Univ. of California, Santa Barbara Free Electron Laser project

    SciTech Connect

    Not Available

    1992-01-01

    The University of California, Santa Barbara (UCSB) Free Electron Laser (FEL) project was initiated in 1981 to test the idea of using an electrostatic accelerator in a recirculating beam mode to produce high-power, continuously tunable, coherent far infrared radiation. The development and application of this device to condensed matter research are briefly recounted. Emphasis was on semiconductor research and two-photon experiments. (RWR)

  11. Contribution to the study of composite materials and their damage. Thesis - Paris VI Univ. - 1984

    NASA Technical Reports Server (NTRS)

    Lene, F.

    1987-01-01

    Chapter 1 describes the homogenization techniques used for defining the overall behavior of composite materials for conventional cases of linear and perfectly glued elastic constituents. Chapters 2 and 3 focus on solving the problems inherent in two types of degenerated situations: elastic media with microcavities, and elastic media containing rigid inclusions. Through suitable definitions of deformation concepts and macroscopic stresses it is shown that conventional theory results apply naturally to these limits.

  12. 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.

  13. 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.

  14. 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.

  15. Study of effects of small perturbations on chaotic systems. [Univ. of Maryland, College Park, Maryland

    SciTech Connect

    Grebogi, C.; Yorke, J.A.

    1993-01-01

    Very brief summaries are given of work on the following topics: prevalence, border crossing bifurcations, numerical procedure for computing the dimension, generalized saddle straddle trajectories methods, and finding typical trajectories numerically.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Studies in Medium Energy Physics. [Dept. of Physics, Univ. of Texas at Austin, Austin, Texas

    SciTech Connect

    Hoffmann, G.W.; McDonough, J.; Purcell, M.J.; Ray, R.L.; Read, D.M.; Worm, S.D.

    1992-12-01

    Progress is briefly reported in the following areas: p + A precision elastic forward-angle cross sections for 500- to 800-MeV p on [sup 40]Ca; precision measurement of D[sub NN] for [sup 13]C([rvec p], [rvec p]) at 500 MeV; design of a polarized nuclear target; search for very rare K[sub L] decays; search for the H dibaryon; experimental search for quark -- gluon plasma; and theoretical work on proton -- nucleus scattering.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Laboratory EXAFS facilities-1980. [Univ. of Washington, Seattle, April 28-30, 1980

    SciTech Connect

    Stern, E.A.

    1980-01-01

    Individual abstracts were prepared for the papers given at this conference. One of these papers has already been cited in ERA, and may be located by reference to the entry CONF-800487--1 in the Report Number Index. The remaining papers will be added to the data base when they are received on tape from AIP. (RWR)

  8. 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.

  9. 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.

  10. [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.

  11. 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.

  12. Chaotic dynamics in accelerator physics. [Dept. of Astrophysical, Planetary, and Atmospheric Sciences, Univ. of Colorado, Boulder

    SciTech Connect

    Cary, J.R.

    1992-11-30

    Substantial progress was in several areas of accelerator dynamics. For developing understanding of longitudinal adiabatic dynamics, and for creating efficiency enhancements of recirculating free-electron lasers, was substantially completed. A computer code for analyzing the critical KAM tori that bound the dynamic aperture in circular machines was developed. Studies of modes that arise due to the interaction of coating beams with a narrow-spectrum impedance have begun. During this research educational and research ties with the accelerator community at large have been strengthened.

  13. 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.

  14. (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.

  15. Liquid jet impingement normal to a disk in zero gravity. Ph.D. Thesis Toledo Univ.

    NASA Technical Reports Server (NTRS)

    Labus, T. L.

    1977-01-01

    The free surface shapes of circular liquid jets impinging normal to sharp-edged disks in zero gravity are determined. Zero gravity drop tower experiments yielded three distinct flow patterns that were classified in terms of the relative effects of surface tension and inertial forces. An order of magnitude analysis was conducted that indicated regions where viscous forces were not significant in the computation of free surface shapes. The free surface analysis was simplified by transforming the governing potential flow equations and boundary conditions into the inverse plane, where the stream function and velocity potential became the coordinates. The resulting nonlinear equations were solved by standard finite difference methods, and comparisons were made with the experimental data for the inertia dominated regime.

  16. 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)

  17. Curved descending landing approach guidance and control. M.S. Thesis - George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Crawford, D. J.

    1974-01-01

    Linear optimal regulator theory is applied to a nonlinear simulation of a transport aircraft performing a helical landing approach. A closed form expression for the quasi-steady nominal flight path is presented along with the method for determining the corresponding constant nominal control inputs. The Jacobian matrices and the weighting matrices in the cost functional are time varying. A method of solving for the optimal feedback gains is reviewed. The control system is tested on several alternative landing approaches using both three and six degree flight path angles. On each landing approach, the aircraft was subjected to large random initial state errors and to randomly directed crosswinds. The system was also tested for sensitivity to changes in the parameters of the aircraft and of the atmosphere. Performance of the optimal controller on all the three degree approaches was very good, and the control system proved to be reasonably insensitive to parametric uncertainties.

  18. 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.

  19. 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.

  20. 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.

  1. Improved Interlock System at the Nuclear Structure Lab at Univ. of Notre Dame

    NASA Astrophysics Data System (ADS)

    Lor, Xao; Lesher, Shelly; Stech, Ed

    2010-11-01

    The current interlock system at the Nuclear Structure Lab (NSL) at the University of Notre Dame requires multiple procedures to be performed in order to start up one of the three accelerators. New features and equipment will be added to the current interlock system to allow access into the experimental rooms safely. This change is necessary because the planned addition of experimental equipment will allow beams from two accelerators to enter the same target hall. In order to minimize the impact of one experiment on another, access will be determined by active monitoring of the radiation levels in the rooms instead of the possibility of accelerated beam being present. New equipment planned to be used in the laboratory are personal dosimeter badges, with a monitor reader for a pass-by data exchange and monitor screens to display live radiation levels and access levels in all of the experimental rooms. This poster will present this procedure and explain how personnel can access the NSL rooms safely while the ion beams are on.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  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. [Theoretical studies in elementary particle physics]. [Physics Dept. , Pennsylvania State Univ

    SciTech Connect

    Collins, J.

    1992-01-01

    Work on the following topics is summarized: polarized hard scattering, hard diffraction, gauge-invariant operators, fundamental QCD, heavy quarks, strongly interacting Ws, and instanton-induced effects in QCD. Some attention is given to the factorization theorem.

  10. Metrology results and lessons learned from the Univ. of Arizona NGST mirror system demonstrator

    NASA Astrophysics Data System (ADS)

    Baiocchi, Dave; Burge, James H.; Cuerden, Brian

    2004-01-01

    The University of Arizona has built a 2-m lightweight active mirror prototype for the next generation of space telescopes. This paper briefly reviews the mirror's opto-mechanical design, and it describes the three different metrology systems that were used to measure it during the actuation process. We also present a list of lessons learned while working on this project. We conclude by discussing one of the successful projects that has come out of this technology.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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…

  1. 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.

  2. 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.

  3. Intermediate/high energy nuclear physics. [Iowa State Univ. , Ames, Iowa

    SciTech Connect

    Vary, J.P.

    1992-01-01

    Progress during the last year is reviewed under the following topics: relativistic hadron--nucleus and nucleus--nucleus collisions (heavy meson production, photon production and fragmentation functions--direct photon production with the QCM and photon fragmentation functions, Cronin efffect and multiple scattering, effective nuclear parton distributions); solving quantum field theories in nonperturbative regime; light-front dynamics and high-spin states (soft form factor of the pion and nucleon for transverse and longitudinal momentum transfers, light front spinors for high-spin objects); high-energy spin physics; relativistic wave equations, quarkonia, and e[sup +]e[sup [minus

  4. Plasma armature railgun launcher simulations at the Univ. of Texas at Austin

    SciTech Connect

    Weeks, D.A.; Weldon, W.F.; Zowarka, R.C. Jr. . Center for Electromechanics)

    1989-01-01

    The Center for Electromechanics at the University of Texas at Austin (CEM-UT) has developed, while performing research associated with several Defense Advanced Research Projects Agency (DARPA) contracts, a velocity dependent friction model that accurately predicts the losses associated with a plasma armature railgun. Test results from CEM-UT's 1 m long, 1.27 cm square bore, plasma-armature railgun have been used to determine the validity of the model. Deviation between calculated and measured performance is typically less than 5% at railgun currents below 500 kA, however, at currents greater than 500 kA, the deviation increases. Experimental evidence suggests that the railguns lack of stiffness and subsequent venting of driving pressure rather than the electromechanical model is primarily responsible for the divergence between predicted and measured results. To test this theory a railgun was built using external preloading rings (Ringfeder) to increase its stiffness. On the first test of the Ringfeder railgun, 625 kA was discharged into the gun and the projectile was accelerated to 5.9 km/s. Test data indicates that the projectile accelerated through the entire length of the railgun and that a minimum amount of plasma leakage occurred during the test. An analysis of the 625-kA test was done to compare the results of CEM-UT's frictional loss model to ablation and viscous drag loss models.

  5. Application of finite element substructuring to composite micromechanics. M.S. Thesis - Akron Univ., May 1984

    NASA Technical Reports Server (NTRS)

    Caruso, J. J.

    1984-01-01

    Finite element substructuring is used to predict unidirectional fiber composite hygral (moisture), thermal, and mechanical properties. COSMIC NASTRAN and MSC/NASTRAN are used to perform the finite element analysis. The results obtained from the finite element model are compared with those obtained from the simplified composite micromechanics equations. A unidirectional composite structure made of boron/HM-epoxy, S-glass/IMHS-epoxy and AS/IMHS-epoxy are studied. The finite element analysis is performed using three dimensional isoparametric brick elements and two distinct models. The first model consists of a single cell (one fiber surrounded by matrix) to form a square. The second model uses the single cell and substructuring to form a nine cell square array. To compare computer time and results with the nine cell superelement model, another nine cell model is constructed using conventional mesh generation techniques. An independent computer program consisting of the simplified micromechanics equation is developed to predict the hygral, thermal, and mechanical properties for this comparison. The results indicate that advanced techniques can be used advantageously for fiber composite micromechanics.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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).

  13. 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.

  14. 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.

  15. Theoretical particle physics. Progress report, December 1, 1079-November 30, 1980. [Physics Dept. , Indiana Univ

    SciTech Connect

    Hendry, A.W.; Lichtenberg, D.B.; Weingarten, D.H.

    1980-08-01

    Work during the past year ranged from phenomenological studies of various quark systems to applications of quantum chromodynamics and lattice gauge theories. On the phenomenological side for mesons, studies of the charmonium and bottomonium families as well as the spectrum of states containing a single b-quark continued. As a result of some improved measurements, the topic of baryon magnetic moments was reconsidered. At the same time the properties of highly excited 3-quark systems were considered in view of the recent confirmation of resonances with spins up through 21/2. Quark configurations allowing for N colors were also studied, where N was varied. In the area of gauge field theories on a lattice, several interesting connections between gauge theories and interacting string models were found. Monte Carlo techniques were developed to study the problem of quark confinement, by means of a lattice version of QCD. Lastly, a new approach to the problem of quantizing gravity was started.

  16. 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.

  17. 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.

  18. High energy hadron-hadron collisions. [Dept. of Physics and Astronomy, Univ. of Georgia, Athens, Georgia

    SciTech Connect

    Chou, T.T.

    1992-01-01

    Results of a study on high energy collisions with the geometrical model are summarized in three parts: (1) the elastic hadron-hadron collision, (2) the inelastic hadron-hadron collision, and (3) e[sup +]e[sup [minus

  19. Simulator investigation of wind shear recovery techniques. M.S. Thesis - George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Hinton, David A.

    1988-01-01

    The objective was the development of practical flight procedures and guidance for near-optimal trajectories during inadvertent wind shear encounters following takeoff. The approach was to conduct preliminary development of candidate strategies using batch simulation of the point mass B737-100 performance model and to evaluate candidate guidance strategies in piloted, real time, six degrees of freedom simulation.

  20. Line-blanketed model stellar atmospheres applied to Sirius. Ph.D. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Fowler, J. W.

    1972-01-01

    The primary goal of this analysis is to determine whether the effects of atomic bound-bound transitions on stellar atmospheric structure can be represented well in models. The investigation is based on an approach which is called the method of artificial absorption edges. The method is described, developed, tested, and applied to the problem of fitting a model stellar atmosphere to Sirius. It is shown that the main features of the entire observed spectrum of Sirius can be reproduced to within the observational uncertainty by a blanketed flux-constant model with T sub eff = 9700 K and Log g = 4.26. The profile of H sub gamma is reproduced completely within the standard deviations of the measurements except near line center, where non-LTE effects are expected to be significant. The equivalent width of H sub gamma, the Paschen slope, the Balmer jump, and the absolute flux at 5550 A all agree with the observed values.

  1. [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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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)

  8. Semiempirical studies of atomic structure. [Dept. of Physics and Astronomy, Univ. of Toledo

    SciTech Connect

    Curtis, L.J.

    1992-01-01

    The energy level structure, transition probabilities, and general spectroscopic properties of highly ionized many-electron systems are studied through the combined use of sensitive semiempirical data systematizations, selected precision experimental measurements, and specialized theoretical computations. Measurements are made primarily through the use of fast ion beam excitation methods, which are combined with available data from laser-and tokamak-produced plasmas, astrophysical sources, and conventional light sources. The experimental studies are strengthened through large-scale ab initio calculations. Typical examples are the following: lifetime measurements in the neon isoelectronic sequence; multiplexed decay curve measurements of Li-like Si XII; and isoelectronic specification of intershell resonance and intercombination decay rates using measured transition probabilities and spectroscopically determined singlet-mixing amplitudes.

  9. Nuclear structure theory. Annual technical progress report, October 1, 1979-August 31, 1980. [Univ. of Rochester

    SciTech Connect

    French, J.B.; Koltun, D.S.

    1980-01-01

    This report summarizes progress during the past year in the following areas of nuclear structure and reaction theory: statistical spectroscopy (including random matrix methods, with applications to fluctuations in spectra and in strength distributions, and to problems of ergodicity; group symmetries in spectral-distribution theory; electromagnetic and ..beta.. transitions); meson scattering and absorption by nuclei (including general scattering theory with absorption, multiple scattering theory and its reactive content, statistical theory of absorption); and meson currents in electromagnetic transitions.

  10. 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.

  11. 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

  12. 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.

  13. Annual Conference in Rhetorical Criticism: Commended Papers (6th, California State Univ., Hayward, May, 1972).

    ERIC Educational Resources Information Center

    Chalip, Alice Grace, Ed.

    At this 1972 conference, upper division and graduate students from nine western colleges submitted papers on the theory, history, and criticism of rhetoric. Three of them are published in this conference report, along with the principal address. In "Rhetorical Criticism as Argument," the principal address, Wayne Brockriede suggests that useful…

  14. 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.

  15. Optimal feedback control for nonlinear control moment gyro systems. Ph.D. Thesis - Virginia Univ.

    NASA Technical Reports Server (NTRS)

    Kyle, R. G.

    1969-01-01

    A study was made, leading to development and analysis of a technique allowing the control moment gyro (CMG) momentum vectors to avoid adverse orientations and thus to provide optimal control for the Apollo Telescope Mount. The technique was formulated in terms of a feedback scheme using a check factor, K, formed as the product of the dot products of the three CMG momentum unit vectors. The parameter K approaches unity for all adverse orientations and was used to initiate a single correction maneuver to rotate the CMG momenta away from a pending adverse orientation and to reduce K to an acceptable value. A digital computer program for ATM simulations was modified to incorporate this correction maneuver and performance was evaluated in simulated cases. Antiparallelism was used as the primary example for the evaluation of the feedback optimization technique.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Modulation of low energy cosmic rays. Ph.D. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Sari, J. W.

    1972-01-01

    The power spectrum of the interplanetary magnetic field were tested, as well as the power spectrum-cosmic diffusion ray coefficient relation at low energies. A first order perturbation solution of the Fokker-Planck equation governing the diffusion, convection, and adiabatic deceleration of galactic cosmic rays in the solar medium was found to relate intensity fluctuations of low energy cosmic rays to local changes in the propagation parameters. Diffusion coefficients and their day to day variations were calculated from interplanetary magnetic field data obtained by Pioneer 6 in 1965/1966. These are compared to simultaneous observations by IMP 3 of the proton flux in three energy channels (20 to 40, 40 to 60, 60 to 80 MeV).

  4. [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.

  5. 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.

  6. [Research in theoretical nuclear physics]. [School of Physics and Astronomy, Univ. of Minnesota

    SciTech Connect

    Not Available

    1989-01-01

    Research in progress and plans for future investigations are summarized briefly for the following topics: microscopic cluster or resonating-group theory (multiconfiguration studies, effects of antisymmetrization in the nucleon-nucleus interaction, application to p + [alpha] bremsstrahlung), RPA ground state correlations, collisions of deformed nuclei, energy dependence of charge-pickup reactions, alpha-capture reactions in medium-weight nuclei, quantum hydrodynamic approach to nuclear matter, neutron stars and pulsars, transverse momentum distributions, intermittency and other correlations, photon and dilepton production, electroweak theory at high temperature, and fractional statistics.

  7. 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 Central

    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. PMID:24825118

  8. The long-term effect of carbon source on the competition between polyphosphorus accumulating organisms and glycogen accumulating organism in a continuous plug-flow anaerobic/aerobic (A/O) process.

    PubMed

    Wang, Yayi; Jiang, Fan; Zhang, Zhaoxiang; Xing, Meiyan; Lu, Zhibo; Wu, Min; Yang, Jiang; Peng, Yongzhen

    2010-01-01

    Laboratory experiments were conducted in a continuous plug-flow anaerobic/aerobic (A/O) process to kinetically investigate the long-term effect of the different carbon sourc