Hot Star Extension to the Hubble Space Telescope Stellar Spectral Library

NASA Astrophysics Data System (ADS)

Khan, Islam; Worthey, Guy

2017-01-01

CCD spectra of 36 stars were obtained from the Space Telescope Imaging Spectrograph (STIS) installed in the Hubble Space Telescope (HST) using three low resolution gratings - G230LB, G430L, and G750L, combined in processing to make single, continuous spectra from 0.2 to 1.0 micrometers. These spectra will be added to the Next Generation Stellar Library (NGSL) after completing the data analysis, reduction, and the required corrections. The stars include normal O-type stars, helium-burning stars, and post-asymptotic giant branch (PAGB) stars. Difficult steps in the data reduction process were removing the cosmic rays from the raw images and defringing of the G750L spectra using fringe flats. Most stars have detectable dust extinction. To aid in analysis, synthetic spectra were generated with various effective temperatures and surface gravities. A five parameter analytic model for the dust extinction correction was adopted. The parameters were varied in order to fit especially the ultraviolet portion of the observed and comparison synthetic spectra. Cross-correlation was used to bring the spectra to a common, final, zero velocity wavelength scale. Some star temperatures obtained from fitting synthetic versus observed spectra vary significantly from literature values. The dust extinction correction parameters also varied for several stars, mostly O stars, indicating variations in dust properties for different lines of sight. Analysis of scattered light effects showed that it was significant only for our two coolest stars.Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555.Support for this work was provided by NASA through grant number HST-GO-14141 from the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

Determination of composition of non-homogeneous GaInNAs layers

NASA Astrophysics Data System (ADS)

Pucicki, D.; Bielak, K.; Ściana, B.; Radziewicz, D.; Latkowska-Baranowska, M.; Kováč, J.; Vincze, A.; Tłaczała, M.

2016-01-01

Dilute nitride GaInNAs alloys grown on GaAs have become perspective materials for so called low-cost GaAs-based devices working within the optical wavelength range up to 1.6 μm. The multilayer structures of GaInNAs/GaAs multi-quantum well (MQW) samples usually are analyzed by using high resolution X-ray diffraction (HRXRD) measurements. However, demands for precise structural characterization of the GaInNAs containing heterostructures requires taking into consideration all inhomogeneities of such structures. This paper describes some of the material challenges and progress in structural characterization of GaInNAs layers. A new algorithm for structural characterization of dilute nitrides which bounds contactless electro-reflectance (CER) or photo-reflectance (PR) measurements and HRXRD analysis results together with GaInNAs quantum well band diagram calculation is presented. The triple quantum well (3QW) GaInNAs/GaAs structures grown by atmospheric-pressure metalorganic vapor-phase epitaxy (AP-MOVPE) were investigated according to the proposed algorithm. Thanks to presented algorithm, more precise structural data including the nonuniformity in the growth direction of GaInNAs/GaAs QWs were achieved. Therefore, the proposed algorithm is mentioned as a nondestructive method for characterization of multicomponent inhomogeneous semiconductor structures with quantum wells.

Star Formation Driven Outflows In Edge-On Spiral Galaxies Based on HST/ACS Observations

NASA Astrophysics Data System (ADS)

Rossa, Joern; Dahlem, M.; Dettmar, R.; van der Marel, R. P.

2007-12-01

We present new results on extraplanar diffuse ionized gas (eDIG) in four late-type, actively star-forming edge-on spirals. The high spatial resolution narrowband imaging observations were obtained with ACS on-board HST. Our H-alpha observations reveal a multitude of structures on both small and large scales. Whereas all four galaxies have been studied with ground-based telescopes before, here the small scale structure of the extended emission line gas is presented for the very first time at a spatial resolution of 0.05", corresponding to 5 pc at the mean distance to our galaxies. The eDIG morphology is very different for all four targets, as a result of their different star formation activity and galaxy mass. There is a very smooth DIG morphology observed in two of the galaxies (NGC4634 and NGC5775), whereas the other two (NGC4700 and NGC7090) show a much more complex morphology with intricate filaments, bubbles and supershells. We discuss how the morphology of the eDIG, in particular the break-up of diffuse emission into filaments in galaxy halos, depends on physical parameters such as galaxy mass and SF activity and other tracers as well as the galactic environment. Support for proposal 10416 was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

HD 202206: A Circumbinary Brown Dwarf System

NASA Astrophysics Data System (ADS)

Benedict, G. Fritz; Harrison, Thomas E.

2017-06-01

Using Hubble Space Telescope Fine Guidance Sensor astrometry and previously published radial velocity measures, we explore the exoplanetary system HD 202206. Our modeling results in a parallax, {π }{abs}=21.96+/- 0.12 milliseconds of arc, a mass for HD 202206 B of {{ M }}B={0.089}-0.006+0.007 {{ M }}⊙ , and a mass for HD 202206 c of {{ M }}c={17.9}-1.8+2.9 {{ M }}{Jup}. HD 202206 is a nearly face-on G + M binary orbited by a brown dwarf. The system architecture that we determine supports past assertions that stability requires a 5:1 mean motion resonance (we find a period ratio, {P}c/{P}B=4.92+/- 0.04) and coplanarity (we find a mutual inclination, {{Φ }}=6^\\circ +/- 2^\\circ ). Based on observations made 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.

NAS Parallel Benchmark. Results 11-96: Performance Comparison of HPF and MPI Based NAS Parallel Benchmarks. 1.0

NASA Technical Reports Server (NTRS)

Saini, Subash; Bailey, David; Chancellor, Marisa K. (Technical Monitor)

1997-01-01

High Performance Fortran (HPF), the high-level language for parallel Fortran programming, is based on Fortran 90. HALF was defined by an informal standards committee known as the High Performance Fortran Forum (HPFF) in 1993, and modeled on TMC's CM Fortran language. Several HPF features have since been incorporated into the draft ANSI/ISO Fortran 95, the next formal revision of the Fortran standard. HPF allows users to write a single parallel program that can execute on a serial machine, a shared-memory parallel machine, or a distributed-memory parallel machine. HPF eliminates the complex, error-prone task of explicitly specifying how, where, and when to pass messages between processors on distributed-memory machines, or when to synchronize processors on shared-memory machines. HPF is designed in a way that allows the programmer to code an application at a high level, and then selectively optimize portions of the code by dropping into message-passing or calling tuned library routines as 'extrinsics'. Compilers supporting High Performance Fortran features first appeared in late 1994 and early 1995 from Applied Parallel Research (APR) Digital Equipment Corporation, and The Portland Group (PGI). IBM introduced an HPF compiler for the IBM RS/6000 SP/2 in April of 1996. Over the past two years, these implementations have shown steady improvement in terms of both features and performance. The performance of various hardware/ programming model (HPF and MPI (message passing interface)) combinations will be compared, based on latest NAS (NASA Advanced Supercomputing) Parallel Benchmark (NPB) results, thus providing a cross-machine and cross-model comparison. Specifically, HPF based NPB results will be compared with MPI based NPB results to provide perspective on performance currently obtainable using HPF versus MPI or versus hand-tuned implementations such as those supplied by the hardware vendors. In addition we would also present NPB (Version 1.0) performance results for

UAS in the NAS Project: Large-Scale Communication Architecture Simulations with NASA GRC Gen5 Radio Model

NASA Technical Reports Server (NTRS)

Kubat, Gregory

2016-01-01

This report provides a description and performance characterization of the large-scale, Relay architecture, UAS communications simulation capability developed for the NASA GRC, UAS in the NAS Project. The system uses a validated model of the GRC Gen5 CNPC, Flight-Test Radio model. Contained in the report is a description of the simulation system and its model components, recent changes made to the system to improve performance, descriptions and objectives of sample simulations used for test and verification, and a sampling and observations of results and performance data.

Neonatal Abstinence Syndrome (NAS) in Southwestern Border States: Examining Trends, Population Correlates, and Implications for Policy.

PubMed

Hussaini, Khaleel S; Garcia Saavedra, Luigi F

2018-03-23

Introduction Neonatal abstinence syndrome (NAS) is withdrawal syndrome in newborns following birth and is primarily caused by maternal drug use during pregnancy. This study examines trends, population correlates, and policy implications of NAS in two Southwest border states. Materials and Methods A cross-sectional analysis of Hospital Inpatient Discharge Data (HIDD) was utilized to examine the incidence of NAS in the Southwest border states of Arizona (AZ) and New Mexico (NM). All inpatient hospital births in AZ and NM from January 1, 2008 through December 31, 2013 with ICD9-CM codes for NAS (779.5), cocaine (760.72), or narcotics (760.75) were extracted. Results During 2008-2013 there were 1472 NAS cases in AZ and 888 in NM. The overall NAS rate during this period was 2.83 per 1000 births (95% CI 2.68-2.97) in AZ and 5.31 (95% CI 4.96-5.66) in NM. NAS rates increased 157% in AZ and 174% in NM. NAS newborns were more likely to have low birth weight, have respiratory distress, more likely to have feeding difficulties, and more likely to be on state Medicaid insurance. AZ border region (border with Mexico) had NAS rates significantly higher than the state rate (4.06 per 1000 births [95% CI 3.68-4.44] vs. 2.83 [95% CI 2.68-2.97], respectively). In NM, the border region rate (2.09 per 1000 births [95% CI 1.48-2.69]) was significantly lower than the state rate (5.31 [95% CI 4.96-5.66]). Conclusions Despite a dramatic increase in the incidence of NAS in the U.S. and, in particular, the Southwest border states of AZ and NM, there is still scant research on the overall incidence of NAS, its assessment in the southwest border, and associated long-term outcomes. The Healthy Border (HB) 2020 binational initiative of the U.S.-Mexico Border Health Commission is an initiative that addresses several public health priorities that not only include chronic and degenerative diseases, infectious diseases, injury prevention, maternal and child health but also mental health and

Probing the z > 6 Universe with the First Hubble Frontier Fields Cluster A2744

NASA Astrophysics Data System (ADS)

Atek, Hakim; Richard, Johan; Kneib, Jean-Paul; Clement, Benjamin; Egami, Eiichi; Ebeling, Harald; Jauzac, Mathilde; Jullo, Eric; Laporte, Nicolas; Limousin, Marceau; Natarajan, Priyamvada

2014-05-01

The Hubble Frontier Fields program combines the capabilities of the Hubble Space Telescope (HST) with the gravitational lensing of massive galaxy clusters to probe the distant universe to an unprecedented depth. Here, we present the results of the first combined HST and Spitzer observations of the cluster A-2744. We combine the full near-infrared data with ancillary optical images to search for gravitationally lensed high-redshift (z >~ 6) galaxies. We report the detection of 15 I 814 dropout candidates at z ~ 6-7 and one Y 105 dropout at z ~ 8 in a total survey area of 1.43 arcmin2 in the source plane. The predictions of our lens model also allow us to identify five multiply imaged systems lying at redshifts between z ~ 6 and z ~ 8. Thanks to constraints from the mass distribution in the cluster, we were able to estimate the effective survey volume corrected for completeness and magnification effects. This was in turn used to estimate the rest-frame ultraviolet luminosity function (LF) at z ~ 6-8. Our LF results are generally in agreement with the most recent blank field estimates, confirming the feasibility of surveys through lensing clusters. Although based on a shallower observations than what will be achieved in the final data set including the full Advanced Camera for Survey observations, the LF presented here goes down to M UV ~-18.5, corresponding to 0.2L sstarf at z ~ 7 with one identified object at M UV ~-15 thanks to the highly magnified survey areas. This early study forecasts the power of using massive galaxy clusters as cosmic telescopes and its complementarity to blank fields. Based on observations made with the NASA/ESA Hubble Space Telescope (HST), which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs 13495 and 11689. Based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory

NASA's UAS NAS Access Project

NASA Technical Reports Server (NTRS)

Johnson, Charles W.

2011-01-01

The vision of the Unmanned Aircraft System (UAS) Integration in the National Airspace System (NAS) Project is "A global transportation system which allows routine access for all classes of UAS." The goal of the UAS Integration in the NAS Project is to "contribute capabilities that reduce technical barriers related to the safety and operational challenges associated with enabling routine UAS access to the NAS." This goal will be accomplished through a two-phased approach based on development of system-level integration of key concepts, technologies and/or procedures, and demonstrations of integrated capabilities in an operationally relevant environment. Phase 1 will take place the first two years of the Project and Phase 2 will take place the following three years. The Phase 1 and 2 technical objectives are: Phase 1: Developing a gap analysis between current state of the art and the Next Generation Air Transportation System (NextGen) UAS Concept of Operations . Validating the key technical areas identified by this Project . Conducting initial modeling, simulation, and flight testing activities . Completing Sub-project Phase 1 deliverables (spectrum requirements, comparative analysis of certification methodologies, etc.) and continue Phase 2 preparation (infrastructure, tools, etc.) Phase 2: Providing regulators with a methodology for developing airworthiness requirements for UAS, and data to support development of certifications standards and regulatory guidance . Providing systems-level, integrated testing of concepts and/or capabilities that address barriers to routine access to the NAS. Through simulation and flight testing, address issues including separation assurance, communications requirements, and human systems integration in operationally relevant environments. The UAS in the NAS Project will demonstrate solutions in specific technology areas, which will address operational/safety issues related to UAS access to the NAS. Since the resource allocation for

Security Controls Hurt Research, NAS Warns.

ERIC Educational Resources Information Center

Kolata, Gina

1982-01-01

A National Academy of Sciences (NAS) report found no evidence that leaks of technical information from universities or other research centers have damaged national security. However, in areas where control is warranted, decisions should be based on criteria. These criteria and issues related to security control and technological transfer are…

New Constraints on the Faint End of the UV Luminosity Function at z ~ 7-8 Using the Gravitational Lensing of the Hubble Frontier Fields Cluster A2744

NASA Astrophysics Data System (ADS)

Atek, Hakim; Richard, Johan; Kneib, Jean-Paul; Jauzac, Mathilde; Schaerer, Daniel; Clement, Benjamin; Limousin, Marceau; Jullo, Eric; Natarajan, Priyamvada; Egami, Eiichi; Ebeling, Harald

2015-02-01

Exploiting the power of gravitational lensing, the Hubble Frontier Fields (HFF) program aims at observing six massive galaxy clusters to explore the distant universe far beyond the limits of blank field surveys. Using the complete Hubble Space Telescope observations of the first HFF cluster A2744, we report the detection of 50 galaxy candidates at z ~ 7 and eight candidates at z ~ 8 in a total survey area of 0.96 arcmin2 in the source plane. Three of these galaxies are multiply imaged by the lensing cluster. Using an updated model of the mass distribution in the cluster we were able to calculate the magnification factor and the effective survey volume for each galaxy in order to compute the ultraviolet galaxy luminosity function (LF) at both redshifts 7 and 8. Our new measurements reliably extend the z ~ 7 UV LF down to an absolute magnitude of M UV ~ -15.5. We find a characteristic magnitude of M\\star UV = -20.90+0.90-0.73 mag and a faint-end slope α =-2.01+0.20-0.28, close to previous determinations in blank fields. We show here for the first time that this slope remains steep down to very faint luminosities of 0.01 L sstarf. Although prone to large uncertainties, our results at z ~ 8 also seem to confirm a steep faint-end slope below 0.1 L sstarf. The HFF program is therefore providing an extremely efficient way to study the faintest galaxy populations at z > 7 that would otherwise be inaccessible with current instrumentation. The full sample of six galaxy clusters will provide even better constraints on the buildup of galaxies at early epochs and their contribution to cosmic reionization. Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs 13495, 11386, 13389, and 11689. STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS

The Rest-Frame Optical Luminosity Functions of Galaxies at 2<=z<=3.5

NASA Astrophysics Data System (ADS)

Marchesini, D.; van Dokkum, P.; Quadri, R.; Rudnick, G.; Franx, M.; Lira, P.; Wuyts, S.; Gawiser, E.; Christlein, D.; Toft, S.

2007-02-01

We present the rest-frame optical (B, V, and R band) luminosity functions (LFs) of galaxies at 2<=z<=3.5, measured from a K-selected sample constructed from the deep NIR MUSYC, the ultradeep FIRES, and the GOODS-CDFS. This sample is unique for its combination of area and range of luminosities. The faint-end slopes of the LFs at z>2 are consistent with those at z~0. The characteristic magnitudes are significantly brighter than the local values (e.g., ~1.2 mag in the R band), while the measured values for Φ* are typically ~5 times smaller. The B-band luminosity density at z~2.3 is similar to the local value, and in the R band it is ~2 times smaller than the local value. We present the LF of distant red galaxies (DRGs), which we compare to that of non-DRGs. While DRGs and non-DRGs are characterized by similar LFs at the bright end, the faint-end slope of the non-DRG LF is much steeper than that of DRGs. The contribution of DRGs to the global densities down to the faintest probed luminosities is 14%-25% in number and 22%-33% in luminosity. From the derived rest-frame U-V colors and stellar population synthesis models, we estimate the mass-to-light ratios (M/L) of the different subsamples. The M/L ratios of DRGs are ~5 times higher (in the R and V bands) than those of non-DRGs. The global stellar mass density at 2<=z<=3.5 appears to be dominated by DRGs, whose contribution is of order ~60%-80% of the global value. Qualitatively similar results are obtained when the population is split by rest-frame U-V color instead of observed J-K color. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555. Also based on observations collected at the European Southern Observatories on Paranal, Chile as part of the ESO program 164.O-0612.

Applications Performance on NAS Intel Paragon XP/S - 15#

NASA Technical Reports Server (NTRS)

Saini, Subhash; Simon, Horst D.; Copper, D. M. (Technical Monitor)

1994-01-01

The Numerical Aerodynamic Simulation (NAS) Systems Division received an Intel Touchstone Sigma prototype model Paragon XP/S- 15 in February, 1993. The i860 XP microprocessor with an integrated floating point unit and operating in dual -instruction mode gives peak performance of 75 million floating point operations (NIFLOPS) per second for 64 bit floating point arithmetic. It is used in the Paragon XP/S-15 which has been installed at NAS, NASA Ames Research Center. The NAS Paragon has 208 nodes and its peak performance is 15.6 GFLOPS. Here, we will report on early experience using the Paragon XP/S- 15. We have tested its performance using both kernels and applications of interest to NAS. We have measured the performance of BLAS 1, 2 and 3 both assembly-coded and Fortran coded on NAS Paragon XP/S- 15. Furthermore, we have investigated the performance of a single node one-dimensional FFT, a distributed two-dimensional FFT and a distributed three-dimensional FFT Finally, we measured the performance of NAS Parallel Benchmarks (NPB) on the Paragon and compare it with the performance obtained on other highly parallel machines, such as CM-5, CRAY T3D, IBM SP I, etc. In particular, we investigated the following issues, which can strongly affect the performance of the Paragon: a. Impact of the operating system: Intel currently uses as a default an operating system OSF/1 AD from the Open Software Foundation. The paging of Open Software Foundation (OSF) server at 22 MB to make more memory available for the application degrades the performance. We found that when the limit of 26 NIB per node out of 32 MB available is reached, the application is paged out of main memory using virtual memory. When the application starts paging, the performance is considerably reduced. We found that dynamic memory allocation can help applications performance under certain circumstances. b. Impact of data cache on the i860/XP: We measured the performance of the BLAS both assembly coded and Fortran

Extending the Calibration of C IV-based Single-epoch Black Hole Mass Estimators for Active Galactic Nuclei

NASA Astrophysics Data System (ADS)

Park, Daeseong; Barth, Aaron J.; Woo, Jong-Hak; Malkan, Matthew A.; Treu, Tommaso; Bennert, Vardha N.; Assef, Roberto J.; Pancoast, Anna

2017-04-01

We provide an updated calibration of C IV λ 1549 broad emission line–based single-epoch (SE) black hole (BH) mass estimators for active galactic nuclei (AGNs) using new data for six reverberation-mapped AGNs at redshift z=0.005{--}0.028 with BH masses (bolometric luminosities) in the range {10}6.5{--}{10}7.5 {M}ȯ ({10}41.7{--}{10}43.8 erg s‑1). New rest-frame UV-to-optical spectra covering 1150–5700 Å for the six AGNs were obtained with the Hubble Space Telescope (HST). Multicomponent spectral decompositions of the HST spectra were used to measure SE emission-line widths for the C IV, Mg II, and Hβ lines, as well as continuum luminosities in the spectral region around each line. We combine the new data with similar measurements for a previous archival sample of 25 AGNs to derive the most consistent and accurate calibrations of the C IV-based SE BH mass estimators against the Hβ reverberation-based masses, using three different measures of broad-line width: full width at half maximum (FWHM), line dispersion ({σ }line}), and mean absolute deviation (MAD). The newly expanded sample at redshift z=0.005{--}0.234 covers a dynamic range in BH mass (bolometric luminosity) of {log}{M}BH}/{M}ȯ =6.5{--}9.1 ({log}{L}bol}/ erg s‑1 = 41.7{--}46.9), and we derive the new C IV-based mass estimators using a Bayesian linear regression analysis over this range. We generally recommend the use of {σ }line} or MAD rather than FWHM to obtain a less biased velocity measurement of the C IV emission line, because its narrow-line component contribution is difficult to decompose from the broad-line profile. Based on observations made 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 NAS 5-26555. These observations are associated with program GO-12922.

Behavioural abnormalities of the hyposulphataemic Nas1 knock-out mouse.

PubMed

Dawson, Paul Anthony; Steane, Sarah Elizabeth; Markovich, Daniel

2004-10-05

We recently generated a sodium sulphate cotransporter knock-out mouse (Nas1-/-) which has increased urinary sulphate excretion and hyposulphataemia. To examine the consequences of disturbed sulphate homeostasis in the modulation of mouse behavioural characteristics, Nas1-/- mice were compared with Nas1+/- and Nas1+/+ littermates in a series of behavioural tests. The Nas1-/- mice displayed significantly (P < 0.001) decreased marble burying behaviour (4.33 +/- 0.82 buried) when compared to Nas1+/+ (7.86 +/- 0.44) and Nas1+/- (8.40 +/- 0.37) animals, suggesting that Nas1-/- mice may have decreased object-induced anxiety. The Nas1-/- mice also displayed decreased locomotor activity by moving less distance (1.53 +/- 0.27 m, P < 0.05) in an open-field test when compared to Nas1+/+ (2.31 +/- 0.24 m) and Nas1+/- (2.15 +/- 0.19 m) mice. The three genotypes displayed similar spatiotemporal and ethological behaviours in the elevated-plus maze and open-field test, with the exception of a decreased defecation frequency by the Nas1-/- mice (40% reduction, P < 0.01). There were no significant differences between Nas1-/- and Nas1+/+ mice in a rotarod performance test of motor coordination and in the forced swim test assessing (anti-)depressant-like behaviours. This is the first study to demonstrate behavioural abnormalities in the hyposulphataemic Nas1-/- mice.

Hybrid Network Architectures for the Next Generation NAS

NASA Technical Reports Server (NTRS)

Madubata, Christian

2003-01-01

To meet the needs of the 21st Century NAS, an integrated, network-centric infrastructure is essential that is characterized by secure, high bandwidth, digital communication systems that support precision navigation capable of reducing position errors for all aircraft to within a few meters. This system will also require precision surveillance systems capable of accurately locating all aircraft, and automatically detecting any deviations from an approved path within seconds and be able to deliver high resolution weather forecasts - critical to create 4- dimensional (space and time) profiles for up to 6 hours for all atmospheric conditions affecting aviation, including wake vortices. The 21st Century NAS will be characterized by highly accurate digital data bases depicting terrain, obstacle, and airport information no matter what visibility conditions exist. This research task will be to perform a high-level requirements analysis of the applications, information and services required by the next generation National Airspace System. The investigation and analysis is expected to lead to the development and design of several national network-centric communications architectures that would be capable of supporting the Next Generation NAS.

Numerical Aerodynamic Simulation (NAS)

NASA Technical Reports Server (NTRS)

Peterson, V. L.; Ballhaus, W. F., Jr.; Bailey, F. R.

1983-01-01

The history of the Numerical Aerodynamic Simulation Program, which is designed to provide a leading-edge capability to computational aerodynamicists, is traced back to its origin in 1975. Factors motivating its development and examples of solutions to successively refined forms of the governing equations are presented. The NAS Processing System Network and each of its eight subsystems are described in terms of function and initial performance goals. A proposed usage allocation policy is discussed and some initial problems being readied for solution on the NAS system are identified.

Applications Performance Under MPL and MPI on NAS IBM SP2

NASA Technical Reports Server (NTRS)

Saini, Subhash; Simon, Horst D.; Lasinski, T. A. (Technical Monitor)

1994-01-01

On July 5, 1994, an IBM Scalable POWER parallel System (IBM SP2) with 64 nodes, was installed at the Numerical Aerodynamic Simulation (NAS) Facility Each node of NAS IBM SP2 is a "wide node" consisting of a RISC 6000/590 workstation module with a clock of 66.5 MHz which can perform four floating point operations per clock with a peak performance of 266 Mflop/s. By the end of 1994, 64 nodes of IBM SP2 will be upgraded to 160 nodes with a peak performance of 42.5 Gflop/s. An overview of the IBM SP2 hardware is presented. The basic understanding of architectural details of RS 6000/590 will help application scientists the porting, optimizing, and tuning of codes from other machines such as the CRAY C90 and the Paragon to the NAS SP2. Optimization techniques such as quad-word loading, effective utilization of two floating point units, and data cache optimization of RS 6000/590 is illustrated, with examples giving performance gains at each optimization step. The conversion of codes using Intel's message passing library NX to codes using native Message Passing Library (MPL) and the Message Passing Interface (NMI) library available on the IBM SP2 is illustrated. In particular, we will present the performance of Fast Fourier Transform (FFT) kernel from NAS Parallel Benchmarks (NPB) under MPL and MPI. We have also optimized some of Fortran BLAS 2 and BLAS 3 routines, e.g., the optimized Fortran DAXPY runs at 175 Mflop/s and optimized Fortran DGEMM runs at 230 Mflop/s per node. The performance of the NPB (Class B) on the IBM SP2 is compared with the CRAY C90, Intel Paragon, TMC CM-5E, and the CRAY T3D.

NAS-current status and future plans

NASA Technical Reports Server (NTRS)

Bailey, F. R.

1987-01-01

The Numerical Aerodynamic Simulation (NAS) has met its first major milestone, the NAS Processing System Network (NPSN) Initial Operating Configuration (IOC). The program has met its goal of providing a national supercomputer facility capable of greatly enhancing the Nation's research and development efforts. Furthermore, the program is fulfilling its pathfinder role by defining and implementing a paradigm for supercomputing system environments. The IOC is only the begining and the NAS Program will aggressively continue to develop and implement emerging supercomputer, communications, storage, and software technologies to strengthen computations as a critical element in supporting the Nation's leadership role in aeronautics.

A Search for Binary Systems among the Nearest L Dwarfs

NASA Astrophysics Data System (ADS)

Reid, I. Neill; Lewitus, E.; Allen, P. R.; Cruz, Kelle L.; Burgasser, Adam J.

2006-08-01

We have used the Near-Infrared Camera and Multi-Object Spectrometer NIC1 camera on the Hubble Space Telescope to obtain high angular resolution images of 52 ultracool dwarfs in the immediate solar neighborhood. Nine systems are resolved as binary, with component separations from 1.5 to 15 AU. Based on current theoretical models and empirical bolometric corrections, all systems have components with similar luminosities and, consequently, high mass ratios, q>0.8. Limiting analysis to L dwarfs within 20 pc, the observed binary fraction is 12%+7-3. Applying Bayesian analysis to our data set, we derive a mass-ratio distribution that peaks strongly at unity. Modeling the semimajor axis distribution as a logarithmic Gaussian, the best fit is centered at loga0=0.8 AU (~6.3 AU), with a (logarithmic) width of +/-0.3. The current data are consistent with an overall binary frequency of ~24%. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

On the possibility of ground-based direct imaging detection of extra-solar planets: the case of TWA-7

NASA Astrophysics Data System (ADS)

Neuhäuser, R.; Brandner, W.; Eckart, A.; Guenther, E.; Alves, J.; Ott, T.; Huélamo, N.; Fernández, M.

2000-02-01

We show that ground-based direct imaging detection of extra-solar planets is possible with current technology. As an example, we present evidence for a possible planetary companion to the young T Tauri star 1RXSJ104230.3-334014 (=TWA-7), discovered by ROSAT as a member of the nearby TW Hya association. In an HST NICMOS F160W image, an object is detected that is more than 9 mag fainter than TWA-7, located 2.445 +/- 0.035'' south-east at a position angle of 142.24 +/- 1.34deg. One year later using the ESO-NTT with the SHARP speckle camera, we obtained H- and K-band detections of this faint object at a separation of 2.536 +/- 0.077'' and a position angle of 139.3 +/- 2.1deg. Given the known proper motion of TWA-7, the pair may form a proper motion pair. If the faint object orbits TWA-7, then its apparent magnitudes of H=16.42 +/- 0.11 and K=16.34 +/- 0.15 mag yield absolute magnitudes consistent with a ~ 106.5 yr old ~ 3 M_jup mass object according to the non-gray theory by Burrows et al. (1997). At ~ 55 pc, the angular separation of ~ 2.5'' corresponds to ~ 138 AU, clearly within typical disk sizes. However, position angles and separations are slightly more consistent with a background object than with a companion. Based on observations obtained at the European Southern Observatory, La Silla (ESO Proposals 62.I-0418 and 63.N-0178), and on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under the NASA contract NAS 5-26555.

The NAS Computational Aerosciences Archive

NASA Technical Reports Server (NTRS)

Miceli, Kristina D.; Globus, Al; Lasinski, T. A. (Technical Monitor)

1995-01-01

In order to further the state-of-the-art in computational aerosciences (CAS) technology, researchers must be able to gather and understand existing work in the field. One aspect of this information gathering is studying published work available in scientific journals and conference proceedings. However, current scientific publications are very limited in the type and amount of information that they can disseminate. Information is typically restricted to text, a few images, and a bibliography list. Additional information that might be useful to the researcher, such as additional visual results, referenced papers, and datasets, are not available. New forms of electronic publication, such as the World Wide Web (WWW), limit publication size only by available disk space and data transmission bandwidth, both of which are improving rapidly. The Numerical Aerodynamic Simulation (NAS) Systems Division at NASA Ames Research Center is in the process of creating an archive of CAS information on the WWW. This archive will be based on the large amount of information produced by researchers associated with the NAS facility. The archive will contain technical summaries and reports of research performed on NAS supercomputers, visual results (images, animations, visualization system scripts), datasets, and any other supporting meta-information. This information will be available via the WWW through the NAS homepage, located at http://www.nas.nasa.gov/, fully indexed for searching. The main components of the archive are technical summaries and reports, visual results, and datasets. Technical summaries are gathered every year by researchers who have been allotted resources on NAS supercomputers. These summaries, together with supporting visual results and references, are browsable by interested researchers. Referenced papers made available by researchers can be accessed through hypertext links. Technical reports are in-depth accounts of tools and applications research projects

Six Years of Parallel Computing at NAS (1987 - 1993): What Have we Learned?

NASA Technical Reports Server (NTRS)

Simon, Horst D.; Cooper, D. M. (Technical Monitor)

1994-01-01

In the fall of 1987 the age of parallelism at NAS began with the installation of a 32K processor CM-2 from Thinking Machines. In 1987 this was described as an "experiment" in parallel processing. In the six years since, NAS acquired a series of parallel machines, and conducted an active research and development effort focused on the use of highly parallel machines for applications in the computational aerosciences. In this time period parallel processing for scientific applications evolved from a fringe research topic into the one of main activities at NAS. In this presentation I will review the history of parallel computing at NAS in the context of the major progress, which has been made in the field in general. I will attempt to summarize the lessons we have learned so far, and the contributions NAS has made to the state of the art. Based on these insights I will comment on the current state of parallel computing (including the HPCC effort) and try to predict some trends for the next six years.

Hubble Tarantula Treasury Project V. The Star Cluster Hodge 301: The Old Face of 30 Doradus

NASA Astrophysics Data System (ADS)

Cignoni, M.; Sabbi, E.; van der Marel, R. P.; Lennon, D. J.; Tosi, M.; Grebel, E. K.; Gallagher, J. S., III; Aloisi, A.; de Marchi, G.; Gouliermis, D. A.; Larsen, S.; Panagia, N.; Smith, L. J.

2016-12-01

Based on color-magnitude diagrams (CMDs) from the Hubble Space Telescope Hubble Tarantula Treasury Project (HTTP) survey, we present the star formation history of Hodge 301, the oldest star cluster in the Tarantula Nebula. The HTTP photometry extends faint enough to reach, for the first time, the cluster pre-main sequence (PMS) turn-on, where the PMS joins the main sequence. Using the location of this feature, along with synthetic CMDs generated with the latest PARSEC models, we find that Hodge 301 is older than previously thought, with an age between 26.5 and 31.5 Myr. From this age, we also estimate that between 38 and 61 Type II supernovae exploded in the region. The same age is derived from the main sequence turn-off, whereas the age derived from the post-main sequence stars is younger and between 20 and 25 Myr. Other relevant parameters are a total stellar mass of ≈8800 ± 800 M ⊙ and average reddening E(B - V) ≈ 0.22-0.24 mag, with a differential reddening δE(B - V) ≈ 0.04 mag. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA Inc., under NASA contract NAS 5-26555.

UAS Integration into the NAS Project

NASA Technical Reports Server (NTRS)

Bauer, Jeff

2010-01-01

The goal of the UAS Integration in the NAS Project is to contribute capabilities that reduce technical barriers related to the safety and operational challenges associated with enabling routine UAS access to the NAS This goal will be accomplished through a two-phased approach of system-level integration of key concepts, technologies and/or procedures, and demonstrations of integrated capabilities in an operationally relevant environment. Technical objectives include: PHASE 1: a) Validating the key technical areas identified by this project. System-level analyses, a State of the Art Analysis (SOAA), and a ConOps will identify the challenges and barriers preventing routine UAS access to the NAS. b) Developing a national roadmap and gap analysis identifying specific deliverables in the area of operations, procedures, and technologies that will impact future policy decisions. PHASE 2: a) Provide regulators with a methodology for developing airworthiness requirements for UAS and data to support development of certifications standards and regulatory guidance. b) Provide systems-level integrated testing of concepts and/or capabilities that address barriers to routine access to the NAS. Through simulation and flight testing, address issues including separation assurance, communications requirements, and Pilot Aircraft Interfaces (PAIs) in operationally relevant environments

The Need for Vendor Source Code at NAS. Revised

NASA Technical Reports Server (NTRS)

Carter, Russell; Acheson, Steve; Blaylock, Bruce; Brock, David; Cardo, Nick; Ciotti, Bob; Poston, Alan; Wong, Parkson; Chancellor, Marisa K. (Technical Monitor)

1997-01-01

The Numerical Aerodynamic Simulation (NAS) Facility has a long standing practice of maintaining buildable source code for installed hardware. There are two reasons for this: NAS's designated pathfinding role, and the need to maintain a smoothly running operational capacity given the widely diversified nature of the vendor installations. NAS has a need to maintain support capabilities when vendors are not able; diagnose and remedy hardware or software problems where applicable; and to support ongoing system software development activities whether or not the relevant vendors feel support is justified. This note provides an informal history of these activities at NAS, and brings together the general principles that drive the requirement that systems integrated into the NAS environment run binaries built from source code, onsite.

Examination of Frameworks for Safe Integration of Intelligent Small UAS into the NAS

NASA Technical Reports Server (NTRS)

Logan, Michael J.

2012-01-01

This paper discusses a proposed framework for the safe integration of small unmanned aerial systems (sUAS) into the National Airspace System (NAS). The paper briefly examines the potential uses of sUAS to build an understanding of the location and frequency of potential future flight operations based on the future applications of the sUAS systems. The paper then examines the types of systems that would be required to meet the application-level demand to determine "classes" of platforms and operations. A framework for categorization of the "intelligence" level of the UAS is postulated for purposes of NAS integration. Finally, constraints on the intelligent systems are postulated to ensure their ease of integration into the NAS.

[Methods in neonatal abstinence syndrome (NAS): results of a nationwide survey in Austria].

PubMed

Bauchinger, S; Sapetschnig, I; Danda, M; Sommer, C; Resch, B; Urlesberger, B; Raith, W

2015-08-01

Neonatal abstinence syndrome (NAS) occurs in neonates whose mothers have taken addictive drugs or were under substitution therapy during pregnancy. Incidence numbers of NAS are on the rise globally, even in Austria NAS is not rare anymore. The aim of our survey was to reveal the status quo of dealing with NAS in Austria. A questionnaire was sent to 20 neonatology departments all over Austria, items included questions on scoring, therapy, breast-feeding and follow-up procedures. The response rate was 95%, of which 94.7% had written guidelines concerning NAS. The median number of children being treated per year for NAS was 4. Finnegan scoring system is used in 100% of the responding departments. Morphine is being used most often, in opiate abuse (100%) as well as in multiple substance abuse (44.4%). The most frequent forms of morphine preparation are morphine and diluted tincture of opium. Frequency as well as dosage of medication vary broadly. 61.1% of the departments supported breast-feeding, regulations concerned participation in a substitution programme and general contraindications (HIV, HCV, HBV). Our results revealed that there is a big west-east gradient in patients being treated per year. NAS is not a rare entity anymore in Austria (up to 50 cases per year in Vienna). Our survey showed that most neonatology departments in Austria treat their patients following written guidelines. Although all of them base these guidelines on international recommendations there is no national consensus. © Georg Thieme Verlag KG Stuttgart · New York.

NAS Grid Benchmarks: A Tool for Grid Space Exploration

NASA Technical Reports Server (NTRS)

Frumkin, Michael; VanderWijngaart, Rob F.; Biegel, Bryan (Technical Monitor)

2001-01-01

We present an approach for benchmarking services provided by computational Grids. It is based on the NAS Parallel Benchmarks (NPB) and is called NAS Grid Benchmark (NGB) in this paper. We present NGB as a data flow graph encapsulating an instance of an NPB code in each graph node, which communicates with other nodes by sending/receiving initialization data. These nodes may be mapped to the same or different Grid machines. Like NPB, NGB will specify several different classes (problem sizes). NGB also specifies the generic Grid services sufficient for running the bench-mark. The implementor has the freedom to choose any specific Grid environment. However, we describe a reference implementation in Java, and present some scenarios for using NGB.

48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

Code of Federal Regulations, 2010 CFR

2010-10-01

... (cold, constant temperature) 5 Entire air-conditioning system (Specified under 600 Sections) 5 Entire... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Payments under fixed-price construction contracts (including NAS). 852.236-83 Section 852.236-83 Federal Acquisition Regulations System...

First Results from the VIRIAL Survey: The Stellar Content of UVJ-selected Quiescent Galaxies at 1.5 < z < 2 from KMOS

NASA Astrophysics Data System (ADS)

Mendel, J. Trevor; Saglia, Roberto P.; Bender, Ralf; Beifiori, Alessandra; Chan, Jeffrey; Fossati, Matteo; Wilman, David J.; Bandara, Kaushala; Brammer, Gabriel B.; Förster Schreiber, Natascha M.; Galametz, Audrey; Kulkarni, Sandesh; Momcheva, Ivelina G.; Nelson, Erica J.; van Dokkum, Pieter G.; Whitaker, Katherine E.; Wuyts, Stijn

2015-05-01

We investigate the stellar populations of 25 massive galaxies (log [{{M}*}/{{M}⊙ }]≥slant 10.9) at 1.5\\lt z\\lt 2 using data obtained with the K-band Multi-Object Spectrograph (KMOS) on the ESO VLT. Targets were selected to be quiescent based on their broadband colors and redshifts using data from the 3D-HST grism survey. The mean redshift of our sample is \\bar{z}=1.75, where KMOS YJ-band data probe age- and metallicity-sensitive absorption features in the rest-frame optical, including the G-band, Fe i, and high-order Balmer lines. Fitting simple stellar population models to a stack of our KMOS spectra, we derive a mean age of 1.03-0.08+0.13 Gyr. We confirm previous results suggesting a correlation between color and age for quiescent galaxies, finding mean ages of 1.22-0.19+0.56 Gyr and 0.85-0.05+0.08 Gyr for the reddest and bluest galaxies in our sample. Combining our KMOS measurements with those obtained from previous studies at 0.2\\lt z\\lt 2 we find evidence for a 2-3 Gyr spread in the formation epoch of massive galaxies. At z\\lt 1 the measured stellar ages are consistent with passive evolution, while at 1\\lt z≲ 2 they appear to saturate at ˜1 Gyr, which likely reflects changing demographics of the (mean) progenitor population. By comparing to star formation histories inferred for “normal” star-forming galaxies, we show that the timescales required to form massive galaxies at z≳ 1.5 are consistent with the enhanced α-element abundances found in massive local early-type galaxies. Based on observations obtained at the Very Large Telescope (VLT) of the European Southern Observatory (ESO), Paranal, Chile (ESO program IDs 092.A-0091, 093.A-0079, 093.A-0187, and 094.A-0287). This work is further based on observations taken by the 3D-HST Treasury Program (GO 12177 and 12328) with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

The Stellar Mass-Halo Mass Relation for Low-mass X-Ray Groups At 0.5< z< 1 in the CDFS With CSI

NASA Astrophysics Data System (ADS)

Patel, Shannon G.; Kelson, Daniel D.; Williams, Rik J.; Mulchaey, John S.; Dressler, Alan; McCarthy, Patrick J.; Shectman, Stephen A.

2015-02-01

Since z˜ 1, the stellar mass density locked in low-mass groups and clusters has grown by a factor of ˜8. Here, we make the first statistical measurements of the stellar mass content of low-mass X-ray groups at 0.5\\lt z\\lt 1, enabling the calibration of stellar-to-halo mass scales for wide-field optical and infrared surveys. Groups are selected from combined Chandra and XMM-Newton X-ray observations in the Chandra Deep Field South. These ultra-deep observations allow us to identify bona fide low-mass groups at high redshift and enable measurements of their total halo masses. We compute aggregate stellar masses for these halos using galaxies from the Carnegie-Spitzer-IMACS (CSI) spectroscopic redshift survey. Stars comprise ˜3%-4% of the total mass of group halos with masses {{10}12.8}\\lt {{M}200}/{{M}⊙ }\\lt {{10}13.5} (about the mass of Fornax and one-fiftieth the mass of Virgo). Complementing our sample with higher mass halos at these redshifts, we find that the stellar-to-halo mass ratio decreases toward higher halo masses, consistent with other work in the local and high redshift universe. The observed scatter about the stellar-halo mass relation is σ ˜ 0.25 dex, which is relatively small and suggests that total group stellar mass can serve as a rough proxy for halo mass. We find no evidence for any significant evolution in the stellar-halo mass relation since z≲ 1. Quantifying the stellar content in groups since this epoch is critical given that hierarchical assembly leads to such halos growing in number density and hosting increasing shares of quiescent galaxies. This Letter includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. This research is based on observations made with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555.

UAS in the NAS Flight Test Series 3 Overview

NASA Technical Reports Server (NTRS)

Murphy, James R.

2015-01-01

The UAS Integration in the NAS Project is conducting a series of flight tests to acheive the following objectives: 1.) Validate results previously collected during project simulations with live data 2.) Evaluate TCAS IISS interoperability 3.) Test fully integrated system in a relevant live test environment 4.) Inform final DAA and C2 MOPS 5.) Reduce risk for Flight Test Series 4.

First-principles study on structure stabilities of α-S and Na-S battery systems

NASA Astrophysics Data System (ADS)

Momida, Hiroyoshi; Oguchi, Tamio

2014-03-01

To understand microscopic mechanisms of charge and discharge reactions in Na-S batteries, there has been increasing needs to study fundamental atomic and electronic structures of elemental S as well as that of Na-S phases. The most stable form of S is known to be an orthorhombic α-S crystal at ambient temperature and pressure, and α-S consists of puckered S8 rings which crystallize in space group Fddd . In this study, the crystal structure of α-S is examined by using first-principles calculations with and without the van der Waals interaction corrections of Grimme's method, and results clearly show that the van der Waals interactions between the S8 rings have crucial roles on cohesion of α-S. We also study structure stabilities of Na2S, NaS, NaS2, and Na2S5 phases with reported crystal structures. Using calculated total energies of the crystal structure models, we estimate discharge voltages assuming discharge reactions from 2Na+ xS -->Na2Sx, and discharge reactions in Na/S battery systems are discussed by comparing with experimental results. This work was partially supported by Elements Strategy Initiative for Catalysts and Batteries (ESICB) of Ministry of Education, Culture, Sports, Science, and Technology (MEXT), Japan.

An Integrated Gate Turnaround Management Concept Leveraging Big Data Analytics for NAS Performance Improvements

NASA Technical Reports Server (NTRS)

Chung, William W.; Ingram, Carla D.; Ahlquist, Douglas Kurt; Chachad, Girish H.

2016-01-01

"Gate Turnaround" plays a key role in the National Air Space (NAS) gate-to-gate performance by receiving aircraft when they reach their destination airport, and delivering aircraft into the NAS upon departing from the gate and subsequent takeoff. The time spent at the gate in meeting the planned departure time is influenced by many factors and often with considerable uncertainties. Uncertainties such as weather, early or late arrivals, disembarking and boarding passengers, unloading/reloading cargo, aircraft logistics/maintenance services and ground handling, traffic in ramp and movement areas for taxi-in and taxi-out, and departure queue management for takeoff are likely encountered on the daily basis. The Integrated Gate Turnaround Management (IGTM) concept is leveraging relevant historical data to support optimization of the gate operations, which include arrival, at the gate, departure based on constraints (e.g., available gates at the arrival, ground crew and equipment for the gate turnaround, and over capacity demand upon departure), and collaborative decision-making. The IGTM concept provides effective information services and decision tools to the stakeholders, such as airline dispatchers, gate agents, airport operators, ramp controllers, and air traffic control (ATC) traffic managers and ground controllers to mitigate uncertainties arising from both nominal and off-nominal airport gate operations. IGTM will provide NAS stakeholders customized decision making tools through a User Interface (UI) by leveraging historical data (Big Data), net-enabled Air Traffic Management (ATM) live data, and analytics according to dependencies among NAS parameters for the stakeholders to manage and optimize the NAS performance in the gate turnaround domain. The application will give stakeholders predictable results based on the past and current NAS performance according to selected decision trees through the UI. The predictable results are generated based on analysis of the

Data communication requirements for the advanced NAS network

NASA Technical Reports Server (NTRS)

Levin, Eugene; Eaton, C. K.; Young, Bruce

1986-01-01

The goal of the Numerical Aerodynamic Simulation (NAS) Program is to provide a powerful computational environment for advanced research and development in aeronautics and related disciplines. The present NAS system consists of a Cray 2 supercomputer connected by a data network to a large mass storage system, to sophisticated local graphics workstations, and by remote communications to researchers throughout the United States. The program plan is to continue acquiring the most powerful supercomputers as they become available. In the 1987/1988 time period it is anticipated that a computer with 4 times the processing speed of a Cray 2 will be obtained and by 1990 an additional supercomputer with 16 times the speed of the Cray 2. The implications of this 20-fold increase in processing power on the data communications requirements are described. The analysis was based on models of the projected workload and system architecture. The results are presented together with the estimates of their sensitivity to assumptions inherent in the models.

48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

Code of Federal Regulations, 2010 CFR

2010-10-01

...-conditioning system (Specified under 600 Sections) 5 Entire boiler plant system (Specified under 700 Sections... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Payments under fixed-price construction contracts (without NAS). 852.236-82 Section 852.236-82 Federal Acquisition Regulations System...

NATIONAL ALCOHOL SURVEY (NAS)

EPA Science Inventory

National Alcohol Survey (NAS) is designed to assess the trends in drinking practices and problems in the national population, including attitudes, norms, treatment and experiences and adverse consequences. It also studies the effects of public policy on drinking practices (i.e., ...

UAS NAS IHITL Test Readiness Review (TRR)

NASA Technical Reports Server (NTRS)

Murphy, Jim; Brignola, Michael P.; Rorie, Conrad; Santiago, Confesor; Guminsky, Mike; Cross, Ken

2014-01-01

Requesting release of IHITL test readiness review (TRR) charts to ensure UAS-NAS project primary stakeholders, the Federal Aviation Administration through the RTCA special committee -228 and the Office of the Secretary of Defense Sense and Avoid Science and Research Panel, are well informed on the IHITL test plan and expected outcomes as they relate to their needs to safely fly UAS in the NAS.

A Descriptive Analysis of Nursing Staff Behaviors in a Teaching Nursing Home: Differences among NAs, LPNs, and RNs.

ERIC Educational Resources Information Center

Burgio, Louis D.; And Others

1990-01-01

Various staff behaviors in nursing home were sampled 7 times a day, 5 days a week over 37 months and were coded separately for registered nurses (RNs), licensed practical nurses (LPNs), and nurses' aides (NAs). Found LPNs displayed significantly more patient care behaviors and NAs significantly more nonwork behaviors than other nursing staff. RNs…

National Airspace System (NAS) open system architecture and protocols

DOT National Transportation Integrated Search

2003-08-14

This standard establishes the open systems data communications architecture and authorized protocol standards for the National Airspace System (NAS). The NAS will consist of various types of processors and communications networks procured from a vari...

One-dimensional carbon-sulfur composite fibers for Na-S rechargeable batteries operating at room temperature.

PubMed

Hwang, Tae Hoon; Jung, Dae Soo; Kim, Joo-Seong; Kim, Byung Gon; Choi, Jang Wook

2013-09-11

Na-S batteries are one type of molten salt battery and have been used to support stationary energy storage systems for several decades. Despite their successful applications based on long cycle lives and low cost of raw materials, Na-S cells require high temperatures above 300 °C for their operations, limiting their propagation into a wide range of applications. Herein, we demonstrate that Na-S cells with solid state active materials can perform well even at room temperature when sulfur-containing carbon composites generated from a simple thermal reaction were used as sulfur positive electrodes. Furthermore, this structure turned out to be robust during repeated (de)sodiation for ~500 cycles and enabled extraordinarily high rate performance when one-dimensional morphology is adopted using scalable electrospinning processes. The current study suggests that solid-state Na-S cells with appropriate atomic configurations of sulfur active materials could cover diverse battery applications where cost of raw materials is critical.

Natural attenuation software (NAS): Assessing remedial strategies and estimating timeframes

USGS Publications Warehouse

Mendez, E.; Widdowson, M.; Chapelle, F.; Casey, C.

2005-01-01

Natural Attenuation Software (NAS) is a screening tool to estimate remediation timeframes for monitored natural attenuation (MNA) and to assist in decision-making on the level of source zone treatment in conjunction with MNA using site-specific remediation objectives. Natural attenuation processes that NAS models include are advection, dispersion, sorption, non-aqueous phase liquid (NAPL) dissolution, and biodegradation of either petroleum hydrocarbons or chlorinated ethylenes. Newly-implemented enhancements to NAS designed to maximize the utility of NAS for site managers were observed. NAS has expanded source contaminant specification options to include chlorinated ethanes and chlorinated methanes, and to allow for the analysis of any other user-defined contaminants that may be subject to microbially-mediated transformations (heavy metals, radioisotopes, etc.). Included is the capability to model co-mingled plumes, with constituents from multiple contaminant categories. To enable comparison of remediation timeframe estimates between MNA and specific engineered remedial actions , NAS was modified to incorporate an estimation technique for timeframes associated with pump-and-treat remediation technology for comparison to MNA. This is an abstract of a paper presented at the 8th International In Situ and On-Site Bioremediation Symposium (Baltimore, MD 6/6-9/2005).

The 0.5-2.22 μm Scattered Light Spectrum of the Disk around TW Hya: Detection of a Partially Filled Disk Gap at 80 AU

NASA Astrophysics Data System (ADS)

Debes, John H.; Jang-Condell, Hannah; Weinberger, Alycia J.; Roberge, Aki; Schneider, Glenn

2013-07-01

We present a 0.5-2.2 μm scattered light spectrum of the circumstellar disk around TW Hya from a combination of spatially resolved Hubble Space Telescope STIS spectroscopy and NICMOS coronagraphic images of the disk. We investigate the morphology of the disk at distances >40 AU over this wide range of wavelengths, and identify the presence of a depression in surface brightness at ~80 AU that could be caused by a gap in the disk. Additionally, we quantify the surface brightness, azimuthal symmetry, and spectral character of the disk as a function of radius. Our analysis shows that the scattering efficiency of the dust is largely neutral to blue over the observed wavelengths. We model the disk as a steady α-disk with an ad hoc gap structure. The thermal properties of the disk are self-consistently calculated using a three-dimensional radiative transfer code that uses ray tracing to model the heating of the disk interior and scattered light images. We find a good fit to the data over a wide range of distances from the star if we use a model disk with a partially filled gap of 30% depth at 80 AU and with a self-similar truncation knee at 100 AU. The origin of the gap is unclear, but it could arise from a transition in the nature of the disk's dust composition or the presence of a planetary companion. Based on scalings to previous hydrodynamic simulations of gap-opening criteria for embedded proto-planets, we estimate that a planetary companion forming the gap could have a mass between 6 and 28 M ⊕. Based on observations made 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 NAS 5-26555. These observations are associated with programs 10167, 8624, 7226, and 7233.

Hubble Space Telescope and Spitzer Imaging of Red and Blue Galaxies at z ~ 2.5: A Correlation between Size and Star Formation Activity from Compact Quiescent Galaxies to Extended Star-forming Galaxies

NASA Astrophysics Data System (ADS)

Toft, S.; van Dokkum, P.; Franx, M.; Labbe, I.; Förster Schreiber, N. M.; Wuyts, S.; Webb, T.; Rudnick, G.; Zirm, A.; Kriek, M.; van der Werf, P.; Blakeslee, J. P.; Illingworth, G.; Rix, H.-W.; Papovich, C.; Moorwood, A.

2007-12-01

We present HST NICMOS+ACS and Spitzer IRAC+MIPS observations of 41 galaxies at 25 in the FIRES MS 1054 field with red and blue rest-frame optical colors. About half of the galaxies are very compact (effective radii re<1 kpc) at rest-frame optical wavelengths; the others are extended (1 kpc5 in the adopted cosmology. We separate actively star-forming galaxies from quiescent galaxies by modeling their rest-frame UV-NIR SEDs. The star-forming galaxies span the full range of sizes, while the quiescent galaxies all have re<2 kpc. In the redshift range where MIPS 24 μm imaging is a sensitive probe of reradiated dust emission (z<2.5), the 24 μm fluxes confirm that the light of the small quiescent galaxies is dominated by old stars, rather than dust-enshrouded star formation or AGN activity. The inferred surface mass densities and velocity dispersions for the quiescent galaxies are very high compared to those in local galaxies. The galaxies follow a Kormendy relation (between surface brightness and size) with approximately the same slope as locally, but shifted to brighter surface brightnesses, consistent with a mean stellar formation redshift of zf~5. This paper demonstrates a direct relation between star formation activity and size at z~2.5 and the existence of a significant population of massive, extremely dense, old stellar systems without readily identifiable counterparts in the local universe. Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555 observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under NASA contract 1407; and observations collected at the European Southern Observatory, Paranal, Chile (ESO Program 164.O-0612).

An Implementation Plan for NFS at NASA's NAS Facility

NASA Technical Reports Server (NTRS)

Lam, Terance L.; Kutler, Paul (Technical Monitor)

1998-01-01

This document discusses how NASA's NAS can benefit from the Sun Microsystems' Network File System (NFS). A case study is presented to demonstrate the effects of NFS on the NAS supercomputing environment. Potential problems are addressed and an implementation strategy is proposed.

UAS in the NAS - Analysis Results and Recommendations for Integration of CNPC and ATC Communications Simulation Report

NASA Technical Reports Server (NTRS)

Kubat, Gregory

2016-01-01

This report addresses a deliverable to the UAS-in-the-NAS project for recommendations for integration of CNPC and ATC communications based on analysis results from modeled radio system and NAS-wide UA communication architecture simulations. For each recommendation, a brief explanation of the rationale for its consideration is provided with any supporting results obtained or observed in our simulation activity.

Strong z ~ 0.5 OVI absorption towards PKS 0405-123: implications for ionization and metallicity of the Cosmic Web

NASA Astrophysics Data System (ADS)

Howk, J. Christopher; Ribaudo, Joseph S.; Lehner, Nicolas; Prochaska, J. Xavier; Chen, Hsiao-Wen

2009-07-01

the total column of warm-hot gas in this absorber as a function of temperature. This system would be unlikely to provide detectable X-ray absorption in the ions OVII or OVIII even if it resided in front of the brighter X-ray sources in the sky. Based on observations made with the NASA-CNES-CSA Far Ultraviolet Spectroscopic Explorer (FUSE). FUSE is operated for NASA by the Johns Hopkins University under NASA contract NAS5-32985. Also based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program 7576. E-mail: jhowk@nd.edu

Functional Requirements Document for HALE UAS Operations in the NAS: Step 1. Version 3

NASA Technical Reports Server (NTRS)

2006-01-01

The purpose of this Functional Requirements Document (FRD) is to compile the functional requirements needed to achieve the Access 5 Vision of "operating High Altitude, Long Endurance (HALE) Unmanned Aircraft Systems (UAS) routinely, safely, and reliably in the national airspace system (NAS)" for Step 1. These functional requirements could support the development of a minimum set of policies, procedures and standards by the Federal Aviation Administration (FAA) and various standards organizations. It is envisioned that this comprehensive body of work will enable the FAA to establish and approve regulations to govern safe operation of UAS in the NAS on a routine or daily "file and fly" basis. The approach used to derive the functional requirements found within this FRD was to decompose the operational requirements and objectives identified within the Access 5 Concept of Operations (CONOPS) into the functions needed to routinely and safely operate a HALE UAS in the NAS. As a result, four major functional areas evolved to enable routine and safe UAS operations for an on-demand basis in the NAS. These four major functions are: Aviate, Navigate, Communicate, and Avoid Hazards. All of the functional requirements within this document can be directly traceable to one of these four major functions. Some functions, however, are traceable to several, or even all, of these four major functions. These cross-cutting functional requirements support the "Command / Control: function as well as the "Manage Contingencies" function. The requirements associated to these high-level functions and all of their supporting low-level functions are addressed in subsequent sections of this document.

Statistical Analysis of NAS Parallel Benchmarks and LINPACK Results

NASA Technical Reports Server (NTRS)

Meuer, Hans-Werner; Simon, Horst D.; Strohmeier, Erich; Lasinski, T. A. (Technical Monitor)

1994-01-01

In the last three years extensive performance data have been reported for parallel machines both based on the NAS Parallel Benchmarks, and on LINPACK. In this study we have used the reported benchmark results and performed a number of statistical experiments using factor, cluster, and regression analyses. In addition to the performance results of LINPACK and the eight NAS parallel benchmarks, we have also included peak performance of the machine, and the LINPACK n and n(sub 1/2) values. Some of the results and observations can be summarized as follows: 1) All benchmarks are strongly correlated with peak performance. 2) LINPACK and EP have each a unique signature. 3) The remaining NPB can grouped into three groups as follows: (CG and IS), (LU and SP), and (MG, FT, and BT). Hence three (or four with EP) benchmarks are sufficient to characterize the overall NPB performance. Our poster presentation will follow a standard poster format, and will present the data of our statistical analysis in detail.

Autotasked Performance in the NAS Workload: A Statistical Analysis

NASA Technical Reports Server (NTRS)

Carter, R. L.; Stockdale, I. E.; Kutler, Paul (Technical Monitor)

1998-01-01

A statistical analysis of the workload performance of a production quality FORTRAN code for five different Cray Y-MP hardware and system software configurations is performed. The analysis was based on an experimental procedure that was designed to minimize correlations between the number of requested CPUs and the time of day the runs were initiated. Observed autotasking over heads were significantly larger for the set of jobs that requested the maximum number of CPUs. Speedups for UNICOS 6 releases show consistent wall clock speedups in the workload of around 2. which is quite good. The observed speed ups were very similar for the set of jobs that requested 8 CPUs and the set that requested 4 CPUs. The original NAS algorithm for determining charges to the user discourages autotasking in the workload. A new charging algorithm to be applied to jobs run in the NQS multitasking queues also discourages NAS users from using auto tasking. The new algorithm favors jobs requesting 8 CPUs over those that request less, although the jobs requesting 8 CPUs experienced significantly higher over head and presumably degraded system throughput. A charging algorithm is presented that has the following desirable characteristics when applied to the data: higher overhead jobs requesting 8 CPUs are penalized when compared to moderate overhead jobs requesting 4 CPUs, thereby providing a charging incentive to NAS users to use autotasking in a manner that provides them with significantly improved turnaround while also maintaining system throughput.

Padrões de refluxo nas veias safenas em homens com insuficiência venosa crônica

PubMed Central

Engelhorn, Carlos Alberto; Coral, Francisco Eduardo; Soares, Isabela Chaves Monteiro; Corrêa, Gabriel Fernando de Araújo; Ogeda, Jaqueline Pozzolo; Hara, Larissa Yuri; Murasse, Luisa Saemi

2016-01-01

Resumo Contexto A insuficiência venosa crônica (IVCr) é frequente e predomina nas mulheres, mas ainda há poucas informações sobre o refluxo nas veias safenas na população masculina. Objetivos Identificar os diferentes padrões de refluxo nas veias safenas magnas (VSMs) e parvas (VSPs) em homens, correlacionando esses dados com a apresentação clínica conforme a classificação Clínica, Etiológica, Anatômica e Fisiopatológica (CEAP). Métodos Foram avaliados 369 membros inferiores de 207 homens pela ultrassonografia vascular (UV) com diagnóstico clínico de IVCr primária. As variáveis analisadas foram a classificação CEAP, o padrão de refluxo nas VSMs e VSPs e a correlação entre os dois. Resultados Nos 369 membros avaliados, 72,9% das VSMs apresentaram refluxo com predominância do padrão segmentar (33,8%). Nas VSPs, 16% dos membros inferiores analisados apresentaram refluxo, sendo o mais frequente o padrão distal (33,9%). Dos membros classificados como C4, C5 e C6, 100% apresentaram refluxo na VSM com predominância do refluxo proximal (25,64%), e 38,46% apresentaram refluxo na VSP com equivalência entre os padrões distal e proximal (33,3%). Refluxo na junção safeno-femoral (JSF) foi detectado em 7,1% dos membros nas classes C0 e C1, 35,6% nas classes C2 e C3, e 64,1% nas classes C4 a C6. Conclusões O padrão de refluxo segmentar é predominante na VSM, e o padrão de refluxo distal é predominante na VSP. A ocorrência de refluxo na JSF é maior em pacientes com IVCr mais avançada. PMID:29930603

Ubiquity and Diversity of Heterotrophic Bacterial nasA Genes in Diverse Marine Environments

PubMed Central

Jiang, Xuexia; Dang, Hongyue; Jiao, Nianzhi

2015-01-01

Nitrate uptake by heterotrophic bacteria plays an important role in marine N cycling. However, few studies have investigated the diversity of environmental nitrate assimilating bacteria (NAB). In this study, the diversity and biogeographical distribution of NAB in several global oceans and particularly in the western Pacific marginal seas were investigated using both cultivation and culture-independent molecular approaches. Phylogenetic analyses based on 16S rRNA and nasA (encoding the large subunit of the assimilatory nitrate reductase) gene sequences indicated that the cultivable NAB in South China Sea belonged to the α-Proteobacteria, γ-Proteobacteria and CFB (Cytophaga-Flavobacteria-Bacteroides) bacterial groups. In all the environmental samples of the present study, α-Proteobacteria, γ-Proteobacteria and Bacteroidetes were found to be the dominant nasA-harboring bacteria. Almost all of the α-Proteobacteria OTUs were classified into three Roseobacter-like groups (I to III). Clone library analysis revealed previously underestimated nasA diversity; e.g. the nasA gene sequences affiliated with β-Proteobacteria, ε-Proteobacteria and Lentisphaerae were observed in the field investigation for the first time, to the best of our knowledge. The geographical and vertical distributions of seawater nasA-harboring bacteria indicated that NAB were highly diverse and ubiquitously distributed in the studied marginal seas and world oceans. Niche adaptation and separation and/or limited dispersal might mediate the NAB composition and community structure in different water bodies. In the shallow-water Kueishantao hydrothermal vent environment, chemolithoautotrophic sulfur-oxidizing bacteria were the primary NAB, indicating a unique nitrate-assimilating community in this extreme environment. In the coastal water of the East China Sea, the relative abundance of Alteromonas and Roseobacter-like nasA gene sequences responded closely to algal blooms, indicating that NAB may be

A Method for Suppressing Line Overload Phenomena Using NAS Battery Systems

NASA Astrophysics Data System (ADS)

Ohtaka, Toshiya; Iwamoto, Shinichi

In this paper, we pay attention to the superior operating control function and instantaneous discharging characteristics of NAS battery systems, and propose a method for determining installation planning and operating control schemes of NAS battery systems for suppressing line overload phenomena. In the stage of planning, a target contingency is identified, and an optimal allocation and capacity of NAS battery systems and an amount of generation changes are determined for the contingency. In the stage of operation, the control strategy of NAS battery system is determined. Simulations are carried out for verifying the validity of the proposed method using the IEEJ 1 machine V system model and an example 2 machine 16 bus system model.

A Universal Transition in Atmospheric Diffusion for Hot Subdwarfs Near 18,000 K

NASA Astrophysics Data System (ADS)

Brown, T. M.; Taylor, J. M.; Cassisi, S.; Sweigart, A. V.; Bellini, A.; Bedin, L. R.; Salaris, M.; Renzini, A.; Dalessandro, E.

2017-12-01

In the color–magnitude diagrams of globular clusters, when the locus of stars on the horizontal branch extends to hot temperatures, discontinuities are observed at colors corresponding to ∼12,000 and ∼18,000 K. The former is the “Grundahl jump” that is associated with the onset of radiative levitation in the atmospheres of hot subdwarfs. The latter is the “Momany jump” that has remained unexplained. Using the Space Telescope Imaging Spectrograph on the Hubble Space Telescope, we have obtained ultraviolet and blue spectroscopy of six hot subdwarfs straddling the Momany jump in the massive globular cluster ω Cen. By comparison to model atmospheres and synthetic spectra, we find that the feature is due primarily to a decrease in atmospheric Fe for stars hotter than the feature, amplified by the temperature dependence of the Fe absorption at these effective temperatures. Based on observations made 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 NAS 5-26555. These observations are associated with program GO-14759.

The Distance to M51

NASA Astrophysics Data System (ADS)

McQuinn, Kristen. B. W.; Skillman, Evan D.; Dolphin, Andrew E.; Berg, Danielle; Kennicutt, Robert

2016-07-01

Great investments of observing time have been dedicated to the study of nearby spiral galaxies with diverse goals ranging from understanding the star formation process to characterizing their dark matter distributions. Accurate distances are fundamental to interpreting observations of these galaxies, yet many of the best studied nearby galaxies have distances based on methods with relatively large uncertainties. We have started a program to derive accurate distances to these galaxies. Here we measure the distance to M51—the Whirlpool galaxy—from newly obtained Hubble Space Telescope optical imaging using the tip of the red giant branch method. We measure the distance modulus to be 8.58 ± 0.10 Mpc (statistical), corresponding to a distance modulus of 29.67 ± 0.02 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian Maximum Likelihood technique that reduces measurement uncertainties. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

Supercomputing 2002: NAS Demo Abstracts

NASA Technical Reports Server (NTRS)

Parks, John (Technical Monitor)

2002-01-01

The hyperwall is a new concept in visual supercomputing, conceived and developed by the NAS Exploratory Computing Group. The hyperwall will allow simultaneous and coordinated visualization and interaction of an array of processes, such as a the computations of a parameter study or the parallel evolutions of a genetic algorithm population. Making over 65 million pixels available to the user, the hyperwall will enable and elicit qualitatively new ways of leveraging computers to accomplish science. It is currently still unclear whether we will be able to transport the hyperwall to SC02. The crucial display frame still has not been completed by the metal fabrication shop, although they promised an August delivery. Also, we are still working the fragile node issue, which may require transplantation of the compute nodes from the present 2U cases into 3U cases. This modification will increase the present 3-rack configuration to 5 racks.

The NAS Alert System: A look at the first eight years

USGS Publications Warehouse

Fuller, Pamela L.; Neilson, Matt; Huge, Dane H.

2013-01-01

The U.S. Geological Survey's Nonindigenous Aquatic Species (NAS) database program (http://nas.er.usgs.gov) tracks the distribution of introduced aquatic organisms across the United States. Awareness of, and timely response to, novel species introductions by those involved in nonindigenous aquatic species management and research requires a framework for rapid dissemination of occurrence data as it is incorporated into the NAS database. In May 2004, the NAS program developed an alert system to notify registered users of new introductions as part of a national early detection/rapid response system. This article summarizes information on system users and dispatched alerts from the system's inception through the end of 2011. The NAS alert system has registered over 1,700 users, with approximately 800 current subscribers. A total of 1,189 alerts had been transmitted through 2011. More alerts were sent for Florida (134 alerts) than for any other state. Fishes comprise the largest taxonomic group of alerts (440), with mollusks, plants, and crustaceans each containing over 100 alerts. Most alerts were for organisms that were intentionally released (414 alerts), with shipping, escape from captivity, and hitchhiking also representing major vectors. To explore the archive of sent alerts and to register, the search and signup page for the alert system can be found online at http://nas.er.usgs.gov/AlertSystem/default.aspx.

NAS Panel endorses science center concept

NASA Astrophysics Data System (ADS)

Science and technology centers, as proposed by President Ronald Reagan in his January 1987 State of the Union message, could make “significant contributions to science and to the nation's economic competitiveness,” according to a new report by a National Academy of Sciences (NAS) panel. What will be necessary to realize these contributions, the panel cautioned, are proper management, adequate resources, and, “above all, the selection of programs for which the centers are the most effective form of organization.”NSF plans to support science and technology centers, beginning October 1, 1988, which is the start of fiscal year 1988. NSF requested guidance from the NAS panel in implementing the program. Although other government agencies will participate in the program, NSF will play the primary role.

UAS-NAS Flight Test Series 3: Test Environment Report

NASA Technical Reports Server (NTRS)

Hoang, Ty; Murphy, Jim; Otto, Neil

2016-01-01

The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration in the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability (SSI), Human Systems Integration (HSI), and Communications (Comm), and Certification to support reducing the barriers of UAS access to the NAS. This research is broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Detect and Avoid (DAA) performance standards, command and control performance standards, and human systems integration. The focus of Test Infrastructure is to enable development and validation of airspace integration procedures and performance standards, including integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project will develop an adaptable, scalable, and schedulable relevant test environment capable of evaluating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project is conducting a series of human-in-the-loop (HITL) and flight test activities that integrate key concepts, technologies and/or procedures in a relevant air traffic environment. Each of the integrated events will build on the technical achievements, fidelity, and

The NAS kernel benchmark program

NASA Technical Reports Server (NTRS)

Bailey, D. H.; Barton, J. T.

1985-01-01

A collection of benchmark test kernels that measure supercomputer performance has been developed for the use of the NAS (Numerical Aerodynamic Simulation) program at the NASA Ames Research Center. This benchmark program is described in detail and the specific ground rules are given for running the program as a performance test.

The role of N-H complexes in the control of localized center recombination in hydrogenated GaInNAs (Conference Presentation)

NASA Astrophysics Data System (ADS)

Whiteside, Vincent R.; Fukuda, Miwa; Estes, Nicholas J.; Wang, Bin; Brown, Collin R.; Hossain, Khalid; Golding, Terry D.; Leroux, Mathieu; Al Khalfioui, Mohamed; Tischler, Joseph G.; Ellis, Chase T.; Glaser, Evan R.; Sellers, Ian R.

2017-04-01

A significant improvement in the quality of dilute nitrides has recently led to the ability to reveal depletion widths in excess of 1 μm at 1 eV [1]. The real viability of dilute nitrides for PV has been recently demonstrated with the reporting of a record efficiency of 43.5% from a 4J MJSC including GaInNAs(Sb) [2]. Despite the progress made, these materials remain poorly understood and work continues to improve their lifetime and reproducibility. We have investigated the possibility of improving the functionality of GaInNAs using hydrogenation to selectively passivate mid-gap defects, while preserving the substitutional nitrogen. Temperature dependent photoluminescence measurements of the intrinsic region of a GaInNAs p-i-n solar cell show a classic "s-shape" associated with localization prior to hydrogenation. No sign of this "s-shape" is evident after hydrogenation, despite the retention of substitutional nitrogen as evidenced by the band absorption of 1 eV. The absence of an "s-shape" at low-temperature in hydrogenated GaInNAs is rather curious since, even in high quality nitrides this behavior is due to the emission of isoelectronic centers created via N-As substitution [3]. The potential origins of this behavior will be discussed. The promise of this process for GaInNAs solar cells was demonstrated by a three-fold improvement in the performance of a hydrogenated device with respect to an as-grown reference [4]. [1] "Wide-depletion width GaInNAs solar cells by thermal annealing," I. R. Sellers, W-S. Tan, K. Smith, S. Hooper, S. Day and M. Kauer, Applied Physics Letters 99, 151111 (2011) [2] "43.5% efficient lattice matched solar cells," M. Wiemer, V. Sabnis, and H. Yuen, Proc. SPIE 8108, 810804 (2011) [3]"Probing the nature of carrier localization in GaInNAs, epilayers using optical methods," T. Ysai, B. Barman, T. Scarce, G. Lindberg, M. Fukuda, V. R. Whiteside, J. C. Keay, M. B. Johnson, I. R. Sellers, M. Al Khalfioui, M. Leroux, B. A. Weinstein and A

National Air Space (NAS) Data Exchange Environment Through 2060

NASA Technical Reports Server (NTRS)

Roy, Aloke

2015-01-01

NASA's NextGen Concepts and Technology Development (CTD) Project focuses on capabilities to improve safety, capacity and efficiency of the National Air Space (NAS). In order to achieve those objectives, NASA sought industry-Government partnerships to research and identify solutions for traffic flow management, dynamic airspace configuration, separation assurance, super density operations, airport surface operations and similar forward-looking air-traffic modernization (ATM) concepts. Data exchanges over NAS being the key enabler for most of these ATM concepts, the Sub-Topic area 3 of the CTD project sought to identify technology candidates that can satisfy air-to-air and air/ground communications needs of the NAS in the year 2060 timeframe. Honeywell, under a two-year contract with NASA, is working on this communications technology research initiative. This report summarizes Honeywell's research conducted during the second year of the study task.

NAS Technical Summaries, March 1993 - February 1994

NASA Technical Reports Server (NTRS)

1995-01-01

NASA created the Numerical Aerodynamic Simulation (NAS) Program in 1987 to focus resources on solving critical problems in aeroscience and related disciplines by utilizing the power of the most advanced supercomputers available. The NAS Program provides scientists with the necessary computing power to solve today's most demanding computational fluid dynamics problems and serves as a pathfinder in integrating leading-edge supercomputing technologies, thus benefitting other supercomputer centers in government and industry. The 1993-94 operational year concluded with 448 high-speed processor projects and 95 parallel projects representing NASA, the Department of Defense, other government agencies, private industry, and universities. This document provides a glimpse at some of the significant scientific results for the year.

UAS-NAS Integrated Human in the Loop: Test Environment Report

NASA Technical Reports Server (NTRS)

Murphy, Jim; Otto, Neil; Jovic, Srba

2015-01-01

The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration in the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability (SSI), Human Systems Integration (HSI), and Communication to support reducing the barriers of UAS access to the NAS. This research was broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Sense and Avoid (SAA) performance standards, command and control performance standards, and human systems integration. The focus of the Test Infrastructure theme was to enable development and validation of airspace integration procedures and performance standards, including the execution of integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project developed an adaptable, scalable, and schedulable relevant test environment incorporating live, virtual, and constructive elements capable of validating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project planned to conduct three integrated events: a Human-in-the-Loop simulation and two Flight Test series that integrated key concepts, technologies and/or procedures in a relevant air traffic environment. Each of

SMART NAS Test Bed Overview

NASA Technical Reports Server (NTRS)

Palopo, Kee

2016-01-01

These slides presents an overview of SMART NAS Test Bed. The test bed is envisioned to be connected to operational systems and to allow a new concept and technology to be evaluated in its realistic environment. Its role as an accelerator of concepts and technologies development, its use-case-driven development approach, and its state are presented.

NAS Applications and Advanced Algorithms

NASA Technical Reports Server (NTRS)

Bailey, David H.; Biswas, Rupak; VanDerWijngaart, Rob; Kutler, Paul (Technical Monitor)

1997-01-01

This paper examines the applications most commonly run on the supercomputers at the Numerical Aerospace Simulation (NAS) facility. It analyzes the extent to which such applications are fundamentally oriented to vector computers, and whether or not they can be efficiently implemented on hierarchical memory machines, such as systems with cache memories and highly parallel, distributed memory systems.

NASA Advanced Supercomputing (NAS) User Services Group

NASA Technical Reports Server (NTRS)

Pandori, John; Hamilton, Chris; Niggley, C. E.; Parks, John W. (Technical Monitor)

2002-01-01

This viewgraph presentation provides an overview of NAS (NASA Advanced Supercomputing), its goals, and its mainframe computer assets. Also covered are its functions, including systems monitoring and technical support.

Evaluating the Information Power Grid using the NAS Grid Benchmarks

NASA Technical Reports Server (NTRS)

VanderWijngaartm Rob F.; Frumkin, Michael A.

2004-01-01

The NAS Grid Benchmarks (NGB) are a collection of synthetic distributed applications designed to rate the performance and functionality of computational grids. We compare several implementations of the NGB to determine programmability and efficiency of NASA's Information Power Grid (IPG), whose services are mostly based on the Globus Toolkit. We report on the overheads involved in porting existing NGB reference implementations to the IPG. No changes were made to the component tasks of the NGB can still be improved.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project - Gen-4 and Gen-5 Radio Plans

NASA Technical Reports Server (NTRS)

Griner, James H.

2014-01-01

NASA's UAS Integration in the NAS project, has partnered with Rockwell Collins to develop a concept Control and Non-Payload Communication (CNPC) system prototype radio, operating on recently allocated UAS frequency spectrum bands. This prototype radio is being used to validate initial proposed performance requirements for UAS control communications. This presentation will give an overview of the current plans for the prototype radio development.

UAS Integration in the NAS: Detect and Avoid

NASA Technical Reports Server (NTRS)

Shively, Jay

2018-01-01

This presentation will cover the structure of the unmanned aircraft systems (UAS) integration into the national airspace system (NAS) project (UAS-NAS Project). The talk also details the motivation of the project to help develop standards for a detect-and-avoid (DAA) system, which is required in order to comply with requirements in manned aviation to see-and-avoid other traffic so as to maintain well clear. The presentation covers accomplishments reached by the project in Phase 1 of the research, and touches on the work to be done in Phase 2. The discussion ends with examples of the display work developed as a result of the Phase 1 research.

(GaIn)(NAs) growth using di-tertiary-butyl-arsano-amine (DTBAA)

NASA Astrophysics Data System (ADS)

Sterzer, E.; Ringler, B.; Nattermann, L.; Beyer, A.; von Hänisch, C.; Stolz, W.; Volz, K.

2017-06-01

III/V semiconductors containing small amounts of Nitrogen (N) are very interesting for a variety of optoelectronic applications. Unfortunately, the conventionally used N precursor 1,1-dimethylhydrazine (UDMHy) has an extremely low N incorporation efficiency in GaAs when grown using metal organic vapor phase epitaxy. Alloying Ga(NAs) with Indium (In) even leads to an exponential reduction of N incorporation. The huge amount of UDMHy in turn changes drastically the growth conditions. Furthermore, the application of this material is still hampered by the large carbon incorporation, most probably originating from the metal organic precursors. Hence, novel precursors for dilute nitride growth are needed. This paper will show (GaIn)(NAs) growth studies with the novel precursor di-tertiary-butyl-arsano-amine in combination with tri-ethyl-gallium and tri-methyl-indium. We show an extremely high N incorporation efficiency in the In containing (GaIn)(NAs). The (GaIn)(NAs) samples investigated in this study have been examined using high resolution X-Ray diffraction, room temperature photoluminescence and atomic force microscope measurements as well as secondary ion mass spectrometry.

Low temperature grown GaNAsSb: A promising material for photoconductive switch application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tan, K. H.; Yoon, S. F.; Wicaksono, S.

2013-09-09

We report a photoconductive switch using low temperature grown GaNAsSb as the active material. The GaNAsSb layer was grown at 200 °C by molecular beam epitaxy in conjunction with a radio frequency plasma-assisted nitrogen source and a valved antimony cracker source. The low temperature growth of the GaNAsSb layer increased the dark resistivity of the switch and shortened the carrier lifetime. The switch exhibited a dark resistivity of 10{sup 7} Ω cm, a photo-absorption of up to 2.1 μm, and a carrier lifetime of ∼1.3 ps. These results strongly support the suitability of low temperature grown GaNAsSb in the photoconductivemore » switch application.« less

Multiwavelength Observations of the Hot DB Star PG 0112+104

NASA Astrophysics Data System (ADS)

Dufour, P.; Desharnais, S.; Wesemael, F.; Chayer, P.; Lanz, T.; Bergeron, P.; Fontaine, G.; Beauchamp, A.; Saffer, R. A.; Kruk, J. W.; Limoges, M.-M.

2010-08-01

We present a comprehensive multiwavelength analysis of the hot DB white dwarf PG 0112+104. Our analysis relies on newly acquired FUSE observations, on medium-resolution FOS and GHRS data, on archival high-resolution GHRS observations, on optical spectrophotometry both in the blue and around Hα, as well as on time-resolved photometry. From the optical data, we derive a self-consistent effective temperature of 31,300 ± 500 K, a surface gravity of log g = 7.8 ± 0.1 (M = 0.52 M sun), and a hydrogen abundance of log N(H)/N(He)< -4.0. The FUSE spectra reveal the presence of C II and C III lines that complement the previous detection of C II transitions with the GHRS. The improved carbon abundance in this hot object is log N(C)/N(He) = -6.15 ± 0.23. No photospheric features associated with other heavy elements are detected. We reconsider the role of PG 0112+104 in the definition of the blue edge of the V777 Her instability strip in light of our high-speed photometry and contrast our results with those of previous observations carried out at the McDonald Observatory. Based on observations with the FUSE satellite, which is operated by the Johns Hopkins University under NASA contract NAS 5-32985; 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 the NASA contract NAS 5-26555; and with the Kitt Peak National Observatory, National Optical Astronomy Observatories, operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation.

NAS Parallel Benchmark Results 11-96. 1.0

NASA Technical Reports Server (NTRS)

Bailey, David H.; Bailey, David; Chancellor, Marisa K. (Technical Monitor)

1997-01-01

The NAS Parallel Benchmarks have been developed at NASA Ames Research Center to study the performance of parallel supercomputers. The eight benchmark problems are specified in a "pencil and paper" fashion. In other words, the complete details of the problem to be solved are given in a technical document, and except for a few restrictions, benchmarkers are free to select the language constructs and implementation techniques best suited for a particular system. These results represent the best results that have been reported to us by the vendors for the specific 3 systems listed. In this report, we present new NPB (Version 1.0) performance results for the following systems: DEC Alpha Server 8400 5/440, Fujitsu VPP Series (VX, VPP300, and VPP700), HP/Convex Exemplar SPP2000, IBM RS/6000 SP P2SC node (120 MHz), NEC SX-4/32, SGI/CRAY T3E, SGI Origin200, and SGI Origin2000. We also report High Performance Fortran (HPF) based NPB results for IBM SP2 Wide Nodes, HP/Convex Exemplar SPP2000, and SGI/CRAY T3D. These results have been submitted by Applied Parallel Research (APR) and Portland Group Inc. (PGI). We also present sustained performance per dollar for Class B LU, SP and BT benchmarks.

Validation of the nursing workload scoring systems "Nursing Activities Score" (NAS), and "Therapeutic Intervention Scoring System For Critically Ill Children" (TISS-C) in a Greek Paediatric Intensive Care Unit.

PubMed

Nieri, Alexandra-Stavroula; Manousaki, Kalliopi; Kalafati, Maria; Padilha, Katia Grilio; Stafseth, Siv K; Katsoulas, Theodoros; Matziou, Vasiliki; Giannakopoulou, Margarita

2018-04-11

To assess the reliability and validity of the Greek version of Nursing Activities Score (NAS), and Therapeutic Intervention Scoring System for Critically Ill Children (TISS-C) in a Greek Paediatric Intensive Care Unit (PICU). A methodological study was performed in one PICU of the largest Paediatric Hospital in Athens-Greece. The culturally adapted and validated Greek NAS version, enriched according to the Norwegian paediatric one (P-NAS), was used. TISS-C and Norwegian paediatric interventions were translated to Greek language and backwards. Therapeutic Intervention Scoring System (TISS-28) was used as a gold standard. Two independent observers simultaneously recorded 30 daily P-NAS and TISS-C records. Totally, 188 daily P-NAS, TISS-C and TISS-28 reports in a sample of 29 patients have been obtained during 5 weeks. Descriptive statistics, reliability and validity measures were applied using SPSS (ver 22.0) (p ≤ 0.05). Kappa was 0.963 for P-NAS and 0.9895 for TISS-C (p < 0.001) and Intraclass Correlation Coefficient for all scale items of TISS-C was 1.00 (p < 0.001). P-NAS, TISS-28 and TISS-C measurements were significantly correlated (0.680 ≤ rho ≤ 0.743, p < 0.001). The mean score(±SD) for TISS-28, P-NAS and TISS-C was 23.05(±5.72), 58.14(±13.98) and 20.21(±9.66) respectively. These results support the validity of P-NAS and TISS-C scales to be used in Greek PICUs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Eta Carinae’s Declining Outflow Seen in the UV, 2002–2015

NASA Astrophysics Data System (ADS)

Davidson, Kris; Ishibashi, Kazunori; Martin, John C.; Humphreys, Roberta M.

2018-05-01

Existing Hubble Space Telescope UV data offer many previously neglected clues to η Car’s behavior since 2000. Here we examine a subset of observations with diverse results. (1) The star’s rapid change of state is confirmed by major changes in UV absorption lines, circumstellar extinction, and other features. (2) N III] λ1750 is one of the two most luminous emission features in η Car’s observable spectrum, comparable to Hα. This and other semi-forbidden lines are useful because they have no P Cyg absorption. (3) N III] multiplet ratios provide the first direct diagnostic of gas densities in η Car’s outflow. They strongly suggest that high-excitation lines originate in condensations within the colliding-wind shocked region. The parameters imply that published models have not adequately represented the essential small size scales. (4) In 2002–2004, a very large amount of N III] emission had anomalous Doppler velocities from +400 to +1200 km s‑1. This is a mystery; we conjecture that it may have resulted from a burst of mass ejection in the 2003.5 periastron event. Various other effects are also difficult to explain and merit further investigation. Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

Proper Motions and Structural Parameters of the Galactic Globular Cluster M71

NASA Astrophysics Data System (ADS)

Cadelano, M.; Dalessandro, E.; Ferraro, F. R.; Miocchi, P.; Lanzoni, B.; Pallanca, C.; Massari, D.

2017-02-01

By exploiting two ACS/HST data sets separated by a temporal baseline of ˜7 years, we have determined the relative stellar proper motions (PMs; providing membership) and the absolute PM of the Galactic globular cluster M71. The absolute PM has been used to reconstruct the cluster orbit within a Galactic, three-component, axisymmetric potential. M71 turns out to be in a low-latitude disk-like orbit inside the Galactic disk, further supporting the scenario in which it lost a significant fraction of its initial mass. Since large differential reddening is known to affect this system, we took advantage of near-infrared, ground-based observations to re-determine the cluster center and density profile from direct star counts. The new structural parameters turn out to be significantly different from the ones quoted in the literature. In particular, M71 has a core and a half-mass radii almost 50% larger than previously thought. Finally, we estimate that the initial mass of M71 was likely one order of magnitude larger than its current value, thus helping to solve the discrepancy with the observed number of X-ray sources. Based on observations collected with the NASA/ESA HST (GO10775, GO12932), obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555.

The Asymmetric Nebula Surrounding the Extreme Red Supergiant VY Canis Majoris

NASA Astrophysics Data System (ADS)

Smith, Nathan; Humphreys, Roberta M.; Davidson, Kris; Gehrz, Robert D.; Schuster, M. T.; Krautter, Joachim

2001-02-01

We present HST/WFPC2 images plus ground-based infrared images and photometry of the very luminous OH/IR star VY Canis Majoris. Our WFPC2 data show a complex distribution of knots and filamentary arcs in the asymmetric reflection nebula around the obscured central star. The reflection arcs may result from multiple, asymmetric ejection episodes due to localized events on VY CMa's surface. Such events probably involve magnetic fields and convection, by analogy with solar activity. Surface photometry indicates that the star may have experienced enhanced mass loss over the past 1000 yr. We also demonstrate that the apparent asymmetry of the nebula results from a combination of high extinction and backscattering by dust grains. Thermal-infrared images reveal a more symmetric distribution, elongated along a nearly east-west direction. VY CMa probably has a flattened disklike distribution of dust with a northeast-southwest polar axis and may be experiencing activity analogous to solar prominences. The presence of an axis of symmetry raises interesting questions for a star the size of Saturn's orbit. Magnetic fields and surface activity may play an important role in VY CMa's mass-loss history. Based on observations made 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 NAS 5-26555.

The State-of-the-art HST Astro-photometric Analysis of the Core of ω Centauri. I. The Catalog

NASA Astrophysics Data System (ADS)

Bellini, A.; Anderson, J.; Bedin, L. R.; King, I. R.; van der Marel, R. P.; Piotto, G.; Cool, A.

2017-06-01

We have constructed the most comprehensive catalog of photometry and proper motions ever assembled for a globular cluster (GC). The core of ωCen has been imaged over 650 times through WFC3's UVIS and IR channels for the purpose of detector calibration. There exist from 4 to over 60 exposures through each of 26 filters stretching continuously from F225W in the UV to F160W in the infrared. Furthermore, the 11 yr baseline between these data and a 2002 ACS survey has allowed us to more than double the proper-motion accuracy and triple the number of well-measured stars compared to our previous groundbreaking effort. This totally unprecedented complete spectral coverage of over 470,000 stars within the cluster's core, from the tip of the red giant branch down to the white dwarfs, provides the best astro-photometric observational database yet to understand the multiple-population phenomenon in any GC. In this first paper of the series, we describe in detail the data-reduction processes and deliver the astro-photometric catalog to the astronomical community. Based on archival observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

Hunting for Shooting Stars in 30 Doradus

NASA Astrophysics Data System (ADS)

de Mink, Selma E.; Lennon, D. J.; Sabbi, E.; Anderson, J.; Bedin, L. R.; Sohn, S.; van der Marel, R. P.; Walborn, N. R.; Bastian, N.; Bressert, E.; Crowther, P. A.; Evans, C. J.; Herrero, A.; Langer, N.; Sana, H.

2012-01-01

We are undertaking an ambitious proper motion survey of massive stars in the 30 Doradus region of the Large Magellanic Cloud using the unique capabilities of HST. We aim to derive the directions of motion of massive runaway stars, searching in particular for stars which have been ejected from the dense star cluster R136. These stars probe the dynamical processes in the core of the cluster. The core has been suggested as a formation site for very massive stars exceeding the canonical upper limit of the IMF. These are possible progenitors of intermediate-mass black holes. Furthermore, they provide insight about the origin of massive field stars, addressing open questions related to the poorly understood process of massive star formation. Some may originate from disrupted binary systems and bear the imprints of interaction with the original companion. They will end their life far away from their birth location as core collapse supernova or possibly even long gamma-ray bursts. Here we discuss the first epoch of observations, presenting a 16'x13' mosaic of the data, and initial results based on comparisons with archival data. SdM acknowledges the NASA Hubble Fellowship grant HST-HF-51270.01-A awarded by STScI, operated by AURA for NASA, contract NAS 5-26555.

Neonatal Abstinence Syndrome (NAS): Transitioning Methadone Treated Infants From An Inpatient to an Outpatient Setting

PubMed Central

Backes, Carl H.; Backes, Carl R.; Gardner, Debra; Nankervis, Craig A.; Giannone, Peter J.; Cordero, Leandro

2013-01-01

Background Each year in the US approximately 50,000 neonates receive inpatient pharmacotherapy for the treatment of neonatal abstinence syndrome (NAS). Objective To compare the safety and efficacy of a traditional inpatient only approach with a combined inpatient and outpatient methadone treatment program. Design/Methods Retrospective review (2007-9). Infants were born to mothers maintained on methadone or buprenorphine in an antenatal substance abuse program. All infants received methadone for NAS treatment as inpatient. Methadone weaning for the traditional group (75 pts) was inpatient while the combined group (46 pts) was outpatient. Results Infants in the traditional and combined groups were similar in demographics, obstetrical risk factors, birth weight, GA and the incidence of prematurity (34 & 31%). Hospital stay was shorter in the combined than in the traditional group (13 vs 25d; p < 0.01). Although the duration of treatment was longer for infants in the combined group (37 vs 21d, p<0.01), the cumulative methadone dose was similar (3.6 vs 3.1mg/kg, p 0.42). Follow-up: Information was available for 80% of infants in the traditional and 100% of infants in the combined group. All infants in the combined group were seen ≤ 72 hours from hospital discharge. Breast feeding was more common among infants in the combined group (24 vs. 8% p<0.05). Following discharge there were no differences between the two groups in hospital readmissions for NAS. Prematurity (<37w GA) was the only predictor for hospital readmission for NAS in both groups (p 0.02, OR 5). Average hospital cost for each infant in the combined group was $13,817 less than in the traditional group. Conclusions A combined inpatient and outpatient methadone treatment in the management of NAS decreases hospital stay and substantially reduces cost. Additional studies are needed to evaluate the potential long term benefits of the combined approach on infants and their families. PMID:21852772

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project KDP-C Review

NASA Technical Reports Server (NTRS)

Grindle, Laurie; Sakahara, Robert; Hackenberg, Davis; Johnson, William

2017-01-01

The topics discussed are the UAS-NAS project life-cycle and ARMD thrust flow down, as well as the UAS environments and how we operate in those environments. NASA's Armstrong Flight Research Center at Edwards, CA, is leading a project designed to help integrate unmanned air vehicles into the world around us. The Unmanned Aircraft Systems Integration in the National Airspace System project, or UAS in the NAS, will contribute capabilities designed to reduce technical barriers related to safety and operational challenges associated with enabling routine UAS access to the NAS. The project falls under the Integrated Systems Research Program office managed at NASA Headquarters by the agency's Aeronautics Research Mission Directorate. NASA's four aeronautics research centers - Armstrong, Ames Research Center, Langley Research Center, and Glenn Research Center - are part of the technology development project. With the use and diversity of unmanned aircraft growing rapidly, new uses for these vehicles are constantly being considered. Unmanned aircraft promise new ways of increasing efficiency, reducing costs, enhancing safety and saving lives 460265main_ED10-0132-16_full.jpg Unmanned aircraft systems such as NASA's Global Hawks (above) and Predator B named Ikhana (below), along with numerous other unmanned aircraft systems large and small, are the prime focus of the UAS in the NAS effort to integrate them into the national airspace. Credits: NASA Photos 710580main_ED07-0243-37_full.jpg The UAS in the NAS project envisions performance-based routine access to all segments of the national airspace for all unmanned aircraft system classes, once all safety-related and technical barriers are overcome. The project will provide critical data to such key stakeholders and customers as the Federal Aviation Administration and RTCA Special Committee 203 (formerly the Radio Technical Commission for Aeronautics) by conducting integrated, relevant system-level tests to adequately address

The NAS parallel benchmarks

NASA Technical Reports Server (NTRS)

Bailey, D. H.; Barszcz, E.; Barton, J. T.; Carter, R. L.; Lasinski, T. A.; Browning, D. S.; Dagum, L.; Fatoohi, R. A.; Frederickson, P. O.; Schreiber, R. S.

1991-01-01

A new set of benchmarks has been developed for the performance evaluation of highly parallel supercomputers in the framework of the NASA Ames Numerical Aerodynamic Simulation (NAS) Program. These consist of five 'parallel kernel' benchmarks and three 'simulated application' benchmarks. Together they mimic the computation and data movement characteristics of large-scale computational fluid dynamics applications. The principal distinguishing feature of these benchmarks is their 'pencil and paper' specification-all details of these benchmarks are specified only algorithmically. In this way many of the difficulties associated with conventional benchmarking approaches on highly parallel systems are avoided.

Navigation in Grid Space with the NAS Grid Benchmarks

NASA Technical Reports Server (NTRS)

Frumkin, Michael; Hood, Robert; Biegel, Bryan A. (Technical Monitor)

2002-01-01

We present a navigational tool for computational grids. The navigational process is based on measuring the grid characteristics with the NAS Grid Benchmarks (NGB) and using the measurements to assign tasks of a grid application to the grid machines. The tool allows the user to explore the grid space and to navigate the execution at a grid application to minimize its turnaround time. We introduce the notion of gridscape as a user view of the grid and show how it can be me assured by NGB, Then we demonstrate how the gridscape can be used with two different schedulers to navigate a grid application through a rudimentary grid.

Looking Backward: Parting Reflections on Higher Education Reform from NAS's Founding President

ERIC Educational Resources Information Center

Balch, Stephen H.

2012-01-01

Twenty-five years at the helm of the National Association of Scholars (NAS) have left the author with vivid memories: of knocks and bruises, peaks of exhilaration and, especially, unforgettable characters. But as for lessons learned, that's a very different story. In this article, the author shares some of the successes that happened in NAS for…

NAS Panel faults export controls

NASA Astrophysics Data System (ADS)

Katzoff, Judith A.

A study prepared by a top-level panel says that current export controls on militarily sensitive U.S. technology may be “overcorrecting” previous weaknesses in that system, resulting in “a complex and confusing control system” that makes it more difficult for U.S. businesses to compete in international markets. Moreover, this control system has “an increasingly corrosive effect” on U.S. relations with allies. The panel recommended that the United States concentrate more effort on bringing about uniformity in the export control policies of countries belonging to the Coordinating Committee on Multilateral Export Controls (CoCom), i.e., most of the member nations in NATO (the North Atlantic Treaty Organization) and Japan.The 21-member panel was appointed by the Committee on Science, Engineering, and Public Policy (COSEPUP), a joint unit of the National Academy of Sciences (NAS), the National Academy of Engineering (NAE), and the Institute of Medicine (IOM). The panel, composed of administrators, researchers, and former government officials, was chaired by AGU member Lew Allen, Jr., director of the Jet Propulsion Laboratory (Pasadena, Calif.) and former chief of staff of the U.S. Air Force. Their report was supported by NAS funds, by a number of private organizations (including AGU), by the U.S. Departments of Commerce, Defense, Energy, and State, by the National Science Foundation, and by the National Aeronautics and Space Administration.

An improved NAS-RIF algorithm for image restoration

NASA Astrophysics Data System (ADS)

Gao, Weizhe; Zou, Jianhua; Xu, Rong; Liu, Changhai; Li, Hengnian

2016-10-01

Space optical images are inevitably degraded by atmospheric turbulence, error of the optical system and motion. In order to get the true image, a novel nonnegativity and support constants recursive inverse filtering (NAS-RIF) algorithm is proposed to restore the degraded image. Firstly the image noise is weaken by Contourlet denoising algorithm. Secondly, the reliable object support region estimation is used to accelerate the algorithm convergence. We introduce the optimal threshold segmentation technology to improve the object support region. Finally, an object construction limit and the logarithm function are added to enhance algorithm stability. Experimental results demonstrate that, the proposed algorithm can increase the PSNR, and improve the quality of the restored images. The convergence speed of the proposed algorithm is faster than that of the original NAS-RIF algorithm.

Upgrades to the Probabilistic NAS Platform Air Traffic Simulation Software

NASA Technical Reports Server (NTRS)

Hunter, George; Boisvert, Benjamin

2013-01-01

This document is the final report for the project entitled "Upgrades to the Probabilistic NAS Platform Air Traffic Simulation Software." This report consists of 17 sections which document the results of the several subtasks of this effort. The Probabilistic NAS Platform (PNP) is an air operations simulation platform developed and maintained by the Saab Sensis Corporation. The improvements made to the PNP simulation include the following: an airborne distributed separation assurance capability, a required time of arrival assignment and conformance capability, and a tactical and strategic weather avoidance capability.

Imaging the nuclear environment of NGC 1365 with the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Kristen, Helmuth; Jorsater, Steven; Lindblad, Per Olof; Boksenberg, Alec

1997-12-01

The region surrounding the active nucleus of the barred spiral galaxy NGC 1365 is observed in the [Oiii] lambda 5007 line and neighbouring continuum using the Faint Object Camera (FOC) aboard the Hubble Space Telescope (HST). In the continuum light numerous bright ``super star clusters'' (SSCs) are seen in the nuclear region. They tend to fall on an elongated ring around the nucleus and contribute about 20 % of the total continuum flux in this wavelength regime. Without applying any extinction correction the brightest SSCs have an absolute luminosity M_B=-14fm1 +/- 0fm3 and are very compact with radii R la 3 pc. Complementary ground-based spectroscopy gives an extinction estimate A_B = 2fm5 +/- 0fm5 towards these regions, indicating a true luminosity M_B = -16fm6 +/- 0fm6 . The bright compact radio source NGC 1365:A is found to coincide spatially with one of the SSCs. We conclude that it is a ``radio supernova''. The HST observations resolve the inner structure of the conical outflow previously seen in the [Oiii] lambda 5007 line in ground-based observations, and reveal a complicated structure of individual emission-line clouds, some of which gather in larger agglomerations. The total luminosity in the [Oiii] line amounts to L_[OIII] =~ 3.7x 10(40) erg s(-1) where about 40 % is emitted by the clouds. 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, and observations at the European Southern Observatory (ESO), La Silla, Chile.

NAS Parallel Benchmarks. 2.4

NASA Technical Reports Server (NTRS)

VanderWijngaart, Rob; Biegel, Bryan A. (Technical Monitor)

2002-01-01

We describe a new problem size, called Class D, for the NAS Parallel Benchmarks (NPB), whose MPI source code implementation is being released as NPB 2.4. A brief rationale is given for how the new class is derived. We also describe the modifications made to the MPI (Message Passing Interface) implementation to allow the new class to be run on systems with 32-bit integers, and with moderate amounts of memory. Finally, we give the verification values for the new problem size.

A Test of Pre-Main-Sequence Evolutionary Models across the Stellar/Substellar Boundary Based on Spectra of the Young Quadruple GG Tauri

NASA Astrophysics Data System (ADS)

White, Russel J.; Ghez, A. M.; Reid, I. Neill; Schultz, Greg

1999-08-01

We present spatially separated optical spectra of the components of the young hierarchical quadruple GG Tau. Spectra of GG Tau Aa and Ab (separation 0.25"~35 AU) were obtained with the Faint Object Spectrograph on board the Hubble Space Telescope. Spectra of GG Tau Ba and Bb (separation 1.48"~207 AU) were obtained with both the HIRES and the LRIS spectrographs on the W. M. Keck telescopes. The components of this minicluster, which span a wide range in spectral type (K7-M7), are used to test both evolutionary models and the temperature scale for very young, low-mass stars under the assumption of coeval formation. Of the evolutionary models tested, those of Baraffe et al. yield the most consistent ages when combined with a temperature scale intermediate between that of dwarfs and giants. The version of the Baraffe et al. models computed with a mixing length nearly twice the pressure scale height is of particular interest, as it predicts masses for GG Tau Aa and Ab that are in agreement with their dynamical mass estimate. Using this evolutionary model and a coeval (at 1.5 Myr) temperature scale, we find that the coldest component of the GG Tau system, GG Tau Bb, is substellar with a mass of 0.044+/-0.006 Msolar. This brown dwarf companion is especially intriguing as it shows signatures of accretion, although this accretion is not likely to alter its mass significantly. GG Tau Bb is currently the lowest mass, spectroscopically confirmed companion to a T Tauri star, and is one of the coldest, lowest mass T Tauri objects in the Taurus-Auriga star-forming region. Based partly 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.

Near-infrared Detection of WD 0806-661 B with the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Luhman, K. L.; Morley, C. V.; Burgasser, A. J.; Esplin, T. L.; Bochanski, J. J.

2014-10-01

WD 0806-661 B is one of the coldest known brown dwarfs (T eff = 300-345 K) based on previous mid-infrared photometry from the Spitzer Space Telescope. In addition, it is a benchmark for testing theoretical models of brown dwarfs because its age and distance are well constrained via its primary star (2 ± 0.5 Gyr, 19.2 ± 0.6 pc). We present the first near-infrared detection of this object, which has been achieved through F110W imaging (~Y + J) with the Wide Field Camera 3 on board the Hubble Space Telescope. We measure a Vega magnitude of m 110 = 25.70 ± 0.08, which implies J ~ 25.0. When combined with the Spitzer photometry, our estimate of J helps to better define the empirical sequence of the coldest brown dwarfs in M 4.5 versus J - [4.5]. The positions of WD 0806-661 B and other Y dwarfs in that diagram are best matched by the cloudy models of Burrows et al. and the cloudless models of Saumon et al., both of which employ chemical equilibrium. The calculations by Morley et al. for 50% cloud coverage differ only modestly from the data. Spectroscopy would enable a more stringent test of the models, but based on our F110W measurement, such observations are currently possible only with Hubble, and would require at least ~10 orbits to reach a signal-to-noise ratio of ~5. Based on observations made with the NASA/ESA Hubble Space Telescope through program 12815, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555, and observations with the ESO Telescopes at Paranal Observatory under programs ID 089.C-0428 and ID 089.C-0597.

Operational implications and proposed infrastructure changes for NAS integration of remotely piloted aircraft (RPA)

DOT National Transportation Integrated Search

2014-12-01

The intent of this report is to provide (1) an initial assessment of National Airspace System (NAS) infrastructure affected by continuing development and deployment of unmanned aircraft systems into the NAS, and (2) a description of process challenge...

UAS in the NAS: Survey Responses by ATC, Manned Aircraft Pilots, and UAS Pilots

NASA Technical Reports Server (NTRS)

Comstock, James R., Jr.; McAdaragh, Raymon; Ghatas, Rania W.; Burdette, Daniel W.; Trujillo, Anna C.

2014-01-01

NASA currently is working with industry and the Federal Aviation Administration (FAA) to establish future requirements for Unmanned Aircraft Systems (UAS) flying in the National Airspace System (NAS). To work these issues NASA has established a multi-center "UAS Integration in the NAS" project. In order to establish Ground Control Station requirements for UAS, the perspective of each of the major players in NAS operations was desired. Three on-line surveys were administered that focused on Air Traffic Controllers (ATC), pilots of manned aircraft, and pilots of UAS. Follow-up telephone interviews were conducted with some survey respondents. The survey questions addressed UAS control, navigation, and communications from the perspective of small and large unmanned aircraft. Questions also addressed issues of UAS equipage, especially with regard to sense and avoid capabilities. From the civilian ATC and military ATC perspectives, of particular interest are how mixed operations (manned / UAS) have worked in the past and the role of aircraft equipage. Knowledge gained from this information is expected to assist the NASA UAS Integration in the NAS project in directing research foci thus assisting the FAA in the development of rules, regulations, and policies related to UAS in the NAS.

UAS in the NAS: Survey Responses by ATC, Manned Aircraft Pilots, and UAS Pilots

NASA Technical Reports Server (NTRS)

Comstock, James R., Jr.; McAdaragh, Raymon; Ghatas, Rania W.; Burdette, Daniel W.; Trujillo, Anna C.

2013-01-01

NASA currently is working with industry and the Federal Aviation Administration (FAA) to establish future requirements for Unmanned Aircraft Systems (UAS) flying in the National Airspace System (NAS). To work these issues NASA has established a multi-center UAS Integration in the NAS project. In order to establish Ground Control Station requirements for UAS, the perspective of each of the major players in NAS operations was desired. Three on-line surveys were administered that focused on Air Traffic Controllers (ATC), pilots of manned aircraft, and pilots of UAS. Follow-up telephone interviews were conducted with some survey respondents. The survey questions addressed UAS control, navigation, and communications from the perspective of small and large unmanned aircraft. Questions also addressed issues of UAS equipage, especially with regard to sense and avoid capabilities. From the ATC and military ATC perspective, of particular interest is how mixed-operations (manned/UAS) have worked in the past and the role of aircraft equipage. Knowledge gained from this information is expected to assist the NASA UAS in the NAS project in directing research foci thus assisting the FAA in the development of rules, regulations, and policies related to UAS in the NAS.

Comparison of Origin 2000 and Origin 3000 Using NAS Parallel Benchmarks

NASA Technical Reports Server (NTRS)

Turney, Raymond D.

2001-01-01

This report describes results of benchmark tests on the Origin 3000 system currently being installed at the NASA Ames National Advanced Supercomputing facility. This machine will ultimately contain 1024 R14K processors. The first part of the system, installed in November, 2000 and named mendel, is an Origin 3000 with 128 R12K processors. For comparison purposes, the tests were also run on lomax, an Origin 2000 with R12K processors. The BT, LU, and SP application benchmarks in the NAS Parallel Benchmark Suite and the kernel benchmark FT were chosen to determine system performance and measure the impact of changes on the machine as it evolves. Having been written to measure performance on Computational Fluid Dynamics applications, these benchmarks are assumed appropriate to represent the NAS workload. Since the NAS runs both message passing (MPI) and shared-memory, compiler directive type codes, both MPI and OpenMP versions of the benchmarks were used. The MPI versions used were the latest official release of the NAS Parallel Benchmarks, version 2.3. The OpenMP versiqns used were PBN3b2, a beta version that is in the process of being released. NPB 2.3 and PBN 3b2 are technically different benchmarks, and NPB results are not directly comparable to PBN results.

Effect of antimony on the deep-level traps in GaInNAsSb thin films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Islam, Muhammad Monirul, E-mail: islam.monir.ke@u.tsukuba.ac.jp; Miyashita, Naoya; Ahsan, Nazmul

2014-09-15

Admittance spectroscopy has been performed to investigate the effect of antimony (Sb) on GaInNAs material in relation to the deep-level defects in this material. Two electron traps, E1 and E2 at an energy level 0.12 and 0.41 eV below the conduction band (E{sub C}), respectively, were found in undoped GaInNAs. Bias-voltage dependent admittance confirmed that E1 is an interface-type defect being spatially localized at the GaInNAs/GaAs interface, while E2 is a bulk-type defect located around mid-gap of GaInNAs layer. Introduction of Sb improved the material quality which was evident from the reduction of both the interface and bulk-type defects.

Dancing in the Dark: New Brown Dwarf Binaries from Kernel Phase Interferometry

NASA Astrophysics Data System (ADS)

Pope, Benjamin; Martinache, Frantz; Tuthill, Peter

2013-04-01

This paper revisits a sample of ultracool dwarfs in the solar neighborhood previously observed with the Hubble Space Telescope's NICMOS NIC1 instrument. We have applied a novel high angular resolution data analysis technique based on the extraction and fitting of kernel phases to archival data. This was found to deliver a dramatic improvement over earlier analysis methods, permitting a search for companions down to projected separations of ~1 AU on NIC1 snapshot images. We reveal five new close binary candidates and present revised astrometry on previously known binaries, all of which were recovered with the technique. The new candidate binaries have sufficiently close separation to determine dynamical masses in a short-term observing campaign. We also present four marginal detections of objects which may be very close binaries or high-contrast companions. Including only confident detections within 19 pc, we report a binary fraction of at least \\epsilon _b = 17.2^{+5.7}_{-3.7} %. The results reported here provide new insights into the population of nearby ultracool binaries, while also offering an incisive case study of the benefits conferred by the kernel phase approach in the recovery of companions within a few resolution elements of the point-spread function core. Based on observations performed with the NASA/ESA Hubble Space Telescope. The Hubble observations are associated with proposal ID 10143 and 10879 and were obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

The Carnegie–Chicago Hubble Program. III. The Distance to NGC 1365 via the Tip of the Red Giant Branch

NASA Astrophysics Data System (ADS)

Jang, In Sung; Hatt, Dylan; Beaton, Rachael L.; Lee, Myung Gyoon; Freedman, Wendy L.; Madore, Barry F.; Hoyt, Taylor J.; Monson, Andrew J.; Rich, Jeffrey A.; Scowcroft, Victoria; Seibert, Mark

2018-01-01

The Carnegie–Chicago Hubble Program (CCHP) seeks to anchor the distance scale of Type Ia supernovae via the Tip of the Red Giant Branch (TRGB) method. Based on deep Hubble Space Telescope ACS/WFC imaging, we present an analysis of the TRGB for the metal-poor halo of NGC 1365, a giant spiral galaxy in the Fornax cluster that was host to the Type Ia supernova SN 2012fr. We have measured the extinction-corrected TRGB magnitude of NGC 1365 to be F814W = 27.34 ± 0.03stat ± 0.04sys mag. In advance of future direct calibration by Gaia, we adopt a provisional I-band TRGB luminosity set at the Large Magellanic Cloud and find a true distance modulus μ 0 = 31.29 ± 0.04stat ± 0.06sys mag or D = 18.1 ± 0.3stat ± 0.5sys Mpc. This measurement is in excellent agreement with recent Cepheid-based distances to NGC 1365 and reveals no significant difference in the distances derived from stars of Populations I and II for this galaxy. We revisit the error budget for the CCHP path to the Hubble constant based on the analysis presented here, i.e., that for one of the most distant Type Ia supernova hosts within our Program, and find that a 2.5% measurement is feasible with the current sample of galaxies and TRGB absolute calibration. Based in part on observations made 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 NAS 5-26555. These observations are associated with program #13691.

The Sirius System and Its Astrophysical Puzzles: Hubble Space Telescope and Ground-based Astrometry

NASA Astrophysics Data System (ADS)

Bond, Howard E.; Schaefer, Gail H.; Gilliland, Ronald L.; Holberg, Jay B.; Mason, Brian D.; Lindenblad, Irving W.; Seitz-McLeese, Miranda; Arnett, W. David; Demarque, Pierre; Spada, Federico; Young, Patrick A.; Barstow, Martin A.; Burleigh, Matthew R.; Gudehus, Donald

2017-05-01

the Mikulski Archive for Space Telescopes at STScI, which are operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

NAS Demand Predictions, Transportation Systems Analysis Model (TSAM) Compared with Other Forecasts

NASA Technical Reports Server (NTRS)

Viken, Jeff; Dollyhigh, Samuel; Smith, Jeremy; Trani, Antonio; Baik, Hojong; Hinze, Nicholas; Ashiabor, Senanu

2006-01-01

The current work incorporates the Transportation Systems Analysis Model (TSAM) to predict the future demand for airline travel. TSAM is a multi-mode, national model that predicts the demand for all long distance travel at a county level based upon population and demographics. The model conducts a mode choice analysis to compute the demand for commercial airline travel based upon the traveler s purpose of the trip, value of time, cost and time of the trip,. The county demand for airline travel is then aggregated (or distributed) to the airport level, and the enplanement demand at commercial airports is modeled. With the growth in flight demand, and utilizing current airline flight schedules, the Fratar algorithm is used to develop future flight schedules in the NAS. The projected flights can then be flown through air transportation simulators to quantify the ability of the NAS to meet future demand. A major strength of the TSAM analysis is that scenario planning can be conducted to quantify capacity requirements at individual airports, based upon different future scenarios. Different demographic scenarios can be analyzed to model the demand sensitivity to them. Also, it is fairly well know, but not well modeled at the airport level, that the demand for travel is highly dependent on the cost of travel, or the fare yield of the airline industry. The FAA projects the fare yield (in constant year dollars) to keep decreasing into the future. The magnitude and/or direction of these projections can be suspect in light of the general lack of airline profits and the large rises in airline fuel cost. Also, changes in travel time and convenience have an influence on the demand for air travel, especially for business travel. Future planners cannot easily conduct sensitivity studies of future demand with the FAA TAF data, nor with the Boeing or Airbus projections. In TSAM many factors can be parameterized and various demand sensitivities can be predicted for future travel. These

A Framework for Safe Integration of Small UAS Into the NAS

NASA Technical Reports Server (NTRS)

Logan, Michael J.; Bland, Geoffrey; Murray, Jennifer

2011-01-01

This paper discusses a proposed framework for the safe integration of small unmanned aerial systems (sUAS) into the National Airspace System (NAS). The paper examines the potential uses of sUAS to build an understanding of the location and frequency of potential future flight operations based on the future applications of the sUAS systems. The paper then examines the types of systems that would be required to meet the application-level demand to determine classes of platforms and operations. Finally, a framework is proposed for both airworthiness and operations that attempts to balance safety with utility for these important systems.

Old but Still Warm: Far-UV Detection of PSR B0950+08

NASA Astrophysics Data System (ADS)

Pavlov, G. G.; Rangelov, B.; Kargaltsev, O.; Reisenegger, A.; Guillot, S.; Reyes, C.

2017-11-01

We report on a Hubble Space Telescope detection of the nearby, old pulsar B0950+08 (d≃ 262 pc, spin-down age 17.5 Myr) in two far-ultraviolet (FUV) bands. We measured the mean flux densities {\\bar{f}}ν =109+/- 6 nJy and 83 ± 14 nJy in the F125LP and F140LP filters (pivot wavelengths 1438 and 1528 Å). Using the FUV data together with previously obtained optical-UV data, we conclude that the optical-FUV spectrum consists of two components—a nonthermal (presumably magnetospheric) power-law spectrum ({f}ν \\propto {ν }α ) with slope α ˜ -1.2 and a thermal spectrum emitted from the bulk of the neutron star (NS) surface with a temperature in the range of (1-3) × 105 K, depending on interstellar extinction and NS radius. These temperatures are much higher than predicted by NS cooling models for such an old pulsar, which means that some heating mechanisms operate in NSs. A plausible mechanism responsible for the high temperature of PSR B0950+08 is the interaction of vortex lines of the faster rotating neutron superfluid with the slower rotating normal matter in the inner NS crust (vortex creep heating). Based on observations made 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 NAS 5-26555. These observations are associated with program #13783.

HST STIS Observations of the Mixing Layer in the Cat’s Eye Nebula

NASA Astrophysics Data System (ADS)

Fang, Xuan; Guerrero, Martín A.; Toalá, Jesús A.; Chu, You-Hua; Gruendl, Robert A.

2016-05-01

Planetary nebulae (PNe) are expected to have a ˜105 K interface layer between the ≥slant 106 K inner hot bubble and the ˜104 K optical nebular shell. The PN structure and evolution, and the X-ray emission, depend critically on the efficiency of the mixing of material at this interface layer. However, neither its location nor its spatial extent have ever been determined. Using high-spatial resolution HST STIS spectroscopic observations of the N v λ λ 1239,1243 lines in the Cat’s Eye Nebula (NGC 6543), we have detected this interface layer and determined its location, extent, and physical properties for the first time in a PN. We confirm that this interface layer, as revealed by the spatial distribution of the N v λ1239 line emission, is located between the hot bubble and the optical nebular shell. We estimate a thickness of 1.5× {10}16 cm and an electron density of ˜200 cm-3 for the mixing layer. With a thermal pressure of ˜2 × 10-8 dyn cm-2, the mixing layer is in pressure equilibrium with the hot bubble and ionized nebular rim of NGC 6543. Based on observations made 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 NAS 5-26555. The observations are associated with program #12509.

77 FR 26555 - Determination of Regulatory Review Period for Purposes of Patent Extension; EGRIFTA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-04

... Animal Drug and Patent Term Restoration Act (Pub. L. 100-670) generally provide that a patent may be extended for a period of up to 5 years so long as the patented item (human drug product, animal drug... periods of time: A testing phase and an approval phase. For human drug products, the testing phase begins...

Hubble Space Telescope far-ultraviolet imaging of the jet in 3C273: a common emission component from optical to X-rays

NASA Astrophysics Data System (ADS)

Jester, Sebastian; Meisenheimer, Klaus; Martel, André R.; Perlman, Eric S.; Sparks, William B.

2007-09-01

We present far-ultraviolet (far-UV) observations at ~150 nm of the jet of quasar 3C273 obtained with the Advanced Camera for Surveys (ACS) Solar Blind Channel onboard the Hubble Space Telescope. While the jet morphology is very similar to that in the optical and near-UV, the spectral energy distributions of the jet's subregions show an upturn in νfν at 150nm compared to 300nm everywhere in the jet. Moreover, the 150-nm flux is compatible with extrapolating the X-ray power law down to the UV region. This constitutes strong support for a common origin of the jet's far-UV and X-ray emission. It implies that even a substantial fraction of the visible light in the X-ray brightest parts of the jet arises from the same spectral component as the X-rays, as had been suggested earlier based on Spitzer Space Telescope observations. We argue that the identification of this UV/X-ray component opens up the possibility to establish the synchrotron origin of the X-ray emission by optical polarimetry. Based on observations made with the NASA/ESA Hubble Space Telescope (HST), obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with HST programme GO-9814. This work was begun at the Particle Astrophysics Center, Fermilab, Batavia, IL 60510, USA. ‡ E-mail: jester@mpia.de

UAS Integration in the NAS FY15 Annual Review

NASA Technical Reports Server (NTRS)

Grindle, Laurie; Randall, Debra; Hackenburg, Davis

2015-01-01

This presentation gives insight into the research activities and efforts being executed in order to integrate unmanned aircraft systems into the national airspace system. This briefing is to inform others of the UAS-NAS progress and future directions.

Nas transgenic mouse line allows visualization of Notch pathway activity in vivo

PubMed Central

Souilhol, Céline; Cormier, Sarah; Monet, Marie; Vandormael-Pournin, Sandrine; Joutel, Anne; Babinet, Charles; Cohen-Tannoudji, Michel

2006-01-01

The Notch signalling pathway plays multiple and important roles in mammals. However, several aspects of its action, in particular the precise mapping of its sites of activity, remain unclear. To address this issue, we have generated a transgenic line carrying a construct consisting of a nls-lacZ reporter gene under the control of a minimal promoter and multiple RBP-Jκ binding sites. Here we show that this transgenic line, we named NAS for Notch Activity Sensor, displays an expression profile that is consistent with current knowledge on Notch activity sites in mice, even though it may not report on all these sites. Moreover, we observe that NAS transgene expression is abolished in a RBP-Jκ deficient background indicating that it indeed requires Notch/RBP-Jκ signalling pathway activity. Thus, the NAS transgenic line constitutes a valuable and versatile tool to gain further insights into the complex and various functions of the Notch signalling pathway. PMID:16708386

Nas transgenic mouse line allows visualization of Notch pathway activity in vivo.

PubMed

Souilhol, Céline; Cormier, Sarah; Monet, Marie; Vandormael-Pournin, Sandrine; Joutel, Anne; Babinet, Charles; Cohen-Tannoudji, Michel

2006-06-01

The Notch signaling pathway plays multiple and important roles in mammals. However, several aspects of its action, in particular, the precise mapping of its sites of activity, remain unclear. To address this issue, we generated a transgenic line carrying a construct consisting of a nls-lacZ reporter gene under the control of a minimal promoter and multiple RBP-Jkappa binding sites. Here we show that this transgenic line, which we termed NAS (for Notch Activity Sensor), displays an expression profile that is consistent with current knowledge on Notch activity sites in mice, even though it may not report on all these sites. Moreover, we observe that NAS transgene expression is abolished in a RBP-Jkappa-deficient background, indicating that it indeed requires Notch/RBP-Jkappa signaling pathway activity. Thus, the NAS transgenic line constitutes a valuable and versatile tool to gain further insights into the complex and various functions of the Notch signaling pathway.

The Three-Dimensional Morphology of VY Canis Majoris. II. Polarimetry and the Line-of-Sight Distribution of the Ejecta

NASA Astrophysics Data System (ADS)

Jones, Terry Jay; Humphreys, Roberta M.; Helton, L. Andrew; Gui, Changfeng; Huang, Xiang

2007-06-01

We use imaging polarimetry taken with the HST Advanced Camera for Surveys High Resolution Camera to explore the three-dimensional structure of the circumstellar dust distribution around the red supergiant VY Canis Majoris. The polarization vectors of the nebulosity surrounding VY CMa show a strong centrosymmetric pattern in all directions except directly east and range from 10% to 80% in fractional polarization. In regions that are optically thin, and therefore likely to have only single scattering, we use the fractional polarization and photometric color to locate the physical position of the dust along the line of sight. Most of the individual arclike features and clumps seen in the intensity image are also features in the fractional polarization map. These features must be distinct geometric objects. If they were just local density enhancements, the fractional polarization would not change so abruptly at the edge of the feature. The location of these features in the ejecta of VY CMa using polarimetry provides a determination of their three-dimensional geometry independent of, but in close agreement with, the results from our study of their kinematics (Paper I). 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 NAS 5-26555.

The State-of-the-art HST Astro-photometric Analysis of the Core of ω Centauri. II. Differential-reddening Map

NASA Astrophysics Data System (ADS)

Bellini, A.; Anderson, J.; van der Marel, R. P.; King, I. R.; Piotto, G.; Bedin, L. R.

2017-06-01

We take advantage of the exquisite quality of the Hubble Space Telescope astro-photometric catalog of the core of ωCen presented in the first paper of this series to derive a high-resolution, high-precision, high-accuracy differential-reddening map of the field. The map has a spatial resolution of 2 × 2 arcsec2 over a total field of view of about 4.‧3 × 4.‧3. The differential reddening itself is estimated via an iterative procedure using five distinct color-magnitude diagrams, which provided consistent results to within the 0.1% level. Assuming an average reddening value E(B - V) = 0.12, the differential reddening within the cluster’s core can vary by up to ±10%, with a typical standard deviation of about 4%. Our differential-reddening map is made available to the astronomical community in the form of a multi-extension FITS file. This differential-reddening map is essential for a detailed understanding of the multiple stellar populations of ωCen, as presented in the next paper in this series. Moreover, it provides unique insight into the level of small spatial-scale extinction variations in the Galactic foreground. Based on archival observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

A High-precision Trigonometric Parallax to an Ancient Metal-poor Globular Cluster

NASA Astrophysics Data System (ADS)

Brown, T. M.; Casertano, S.; Strader, J.; Riess, A.; VandenBerg, D. A.; Soderblom, D. R.; Kalirai, J.; Salinas, R.

2018-03-01

Using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST), we have obtained a direct trigonometric parallax for the nearest metal-poor globular cluster, NGC 6397. Although trigonometric parallaxes have been previously measured for many nearby open clusters, this is the first parallax for an ancient metal-poor population—one that is used as a fundamental template in many stellar population studies. This high-precision measurement was enabled by the HST/WFC3 spatial-scanning mode, providing hundreds of astrometric measurements for dozens of stars in the cluster and also for Galactic field stars along the same sightline. We find a parallax of 0.418 ± 0.013 ± 0.018 mas (statistical, systematic), corresponding to a true distance modulus of 11.89 ± 0.07 ± 0.09 mag (2.39 ± 0.07 ± 0.10 kpc). The V luminosity at the stellar main-sequence turnoff implies an absolute cluster age of 13.4 ± 0.7 ± 1.2 Gyr. Based on observations made 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 NAS 5-26555. These observations are associated with programs GO-13817, GO-14336, and GO-14773.

HST-COS Observations of AGNs. III. Spectral Constraints in the Lyman Continuum from Composite COS/G140L Data

NASA Astrophysics Data System (ADS)

Tilton, Evan M.; Stevans, Matthew L.; Shull, J. Michael; Danforth, Charles W.

2016-01-01

The rest-frame ultraviolet (UV) spectra of active galactic nuclei (AGNs) are important diagnostics of both accretion disk physics and their contribution to the metagalactic ionizing UV background. Though the mean AGN spectrum is well characterized with composite spectra at wavelengths greater than 912 Å, the shorter-wavelength extreme-UV (EUV) remains poorly studied. In this third paper in a series on the spectra of AGNs, we combine 11 new spectra taken with the Cosmic Origins Spectrograph on the Hubble Space Telescope with archival spectra to characterize the typical EUV spectral slope of AGNs from λrest ˜ 850 Å down to λrest ˜ 425 Å. Parameterizing this slope as a power law, we obtain Fν ∝ ν-0.72±0.26, but we also discuss the limitations and systematic uncertainties of this model. We identify broad emission features in this spectral region, including emission due to ions of O, Ne, Mg, and other species, and we limit the intrinsic He I 504 Å photoelectric absorption edge opacity to τHe I < 0.047. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

The Role of Quenching Time in the Evolution of the Mass-size Relation of Passive Galaxies from the Wisp Survey

NASA Astrophysics Data System (ADS)

Zanella, A.; Scarlata, C.; Corsini, E. M.; Bedregal, A. G.; Dalla Bontà, E.; Atek, H.; Bunker, A. J.; . Colbert, J.; Dai, Y. S.; Henry, A.; Malkan, M.; Martin, C.; Rafelski, M.; Rutkowski, M. J.; Siana, B.; Teplitz, H.

2016-06-01

We analyze how passive galaxies at z ˜ 1.5 populate the mass-size plane as a function of their stellar age, to understand if the observed size growth with time can be explained with the appearance of larger quenched galaxies at lower redshift. We use a sample of 32 passive galaxies extracted from the Wide Field Camera 3 Infrared Spectroscopic Parallel (WISP) survey with spectroscopic redshift 1.3 ≲ z ≲ 2.05, specific star formation rates lower than 0.01 Gyr-1, and stellar masses above 4.5 × 1010 M ⊙. All galaxies have spectrally determined stellar ages from fitting of their rest-frame optical spectra and photometry with stellar population models. When dividing our sample into young (age ≤2.1 Gyr) and old (age >2.1 Gyr) galaxies we do not find a significant trend in the distributions of the difference between the observed radius and that predicted by the mass-size relation. This result indicates that the relation between the galaxy age and its distance from the mass-size relation, if it exists, is rather shallow, with a slope α ≳ -0.6. At face value, this finding suggests that multiple dry and/or wet minor mergers, rather than the appearance of newly quenched galaxies, are mainly responsible for the observed time evolution of the mass-size relation in passive galaxies. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

Object-Oriented Implementation of the NAS Parallel Benchmarks using Charm++

NASA Technical Reports Server (NTRS)

Krishnan, Sanjeev; Bhandarkar, Milind; Kale, Laxmikant V.

1996-01-01

This report describes experiences with implementing the NAS Computational Fluid Dynamics benchmarks using a parallel object-oriented language, Charm++. Our main objective in implementing the NAS CFD kernel benchmarks was to develop a code that could be used to easily experiment with different domain decomposition strategies and dynamic load balancing. We also wished to leverage the object-orientation provided by the Charm++ parallel object-oriented language, to develop reusable abstractions that would simplify the process of developing parallel applications. We first describe the Charm++ parallel programming model and the parallel object array abstraction, then go into detail about each of the Scalar Pentadiagonal (SP) and Lower/Upper Triangular (LU) benchmarks, along with performance results. Finally we conclude with an evaluation of the methodology used.

78 FR 12951 - TRICARE; Elimination of the Non-Availability Statement (NAS) Requirement for Non-Emergency...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-26

... There are no anticipated budgetary health care cost increases. Requiring a NAS for a relatively few non... Inpatient Mental Health Care AGENCY: Office of the Secretary, Department of Defense. ACTION: Final rule... inpatient mental health care in order for a TRICARE Standard beneficiary's claim to be paid. Currently, NAS...

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project FY17 Annual Review

NASA Technical Reports Server (NTRS)

Sakahara, Robert; Hackenberg, Davis; Johnson, William

2017-01-01

This presentation was presented to the Integrated Aviation Systems Program at the FY17 Annual Review of the UAS-NAS project. The presentation captures the overview of the work completed by the UAS-NAS project and its subprojects.

Parallelization of NAS Benchmarks for Shared Memory Multiprocessors

NASA Technical Reports Server (NTRS)

Waheed, Abdul; Yan, Jerry C.; Saini, Subhash (Technical Monitor)

1998-01-01

This paper presents our experiences of parallelizing the sequential implementation of NAS benchmarks using compiler directives on SGI Origin2000 distributed shared memory (DSM) system. Porting existing applications to new high performance parallel and distributed computing platforms is a challenging task. Ideally, a user develops a sequential version of the application, leaving the task of porting to new generations of high performance computing systems to parallelization tools and compilers. Due to the simplicity of programming shared-memory multiprocessors, compiler developers have provided various facilities to allow the users to exploit parallelism. Native compilers on SGI Origin2000 support multiprocessing directives to allow users to exploit loop-level parallelism in their programs. Additionally, supporting tools can accomplish this process automatically and present the results of parallelization to the users. We experimented with these compiler directives and supporting tools by parallelizing sequential implementation of NAS benchmarks. Results reported in this paper indicate that with minimal effort, the performance gain is comparable with the hand-parallelized, carefully optimized, message-passing implementations of the same benchmarks.

Utilizing Traveler Demand Modeling to Predict Future Commercial Flight Schedules in the NAS

NASA Technical Reports Server (NTRS)

Viken, Jeff; Dollyhigh, Samuel; Smith, Jeremy; Trani, Antonio; Baik, Hojong; Hinze, Nicholas; Ashiabor, Senanu

2006-01-01

The current work incorporates the Transportation Systems Analysis Model (TSAM) to predict the future demand for airline travel. TSAM is a multi-mode, national model that predicts the demand for all long distance travel at a county level based upon population and demographics. The model conducts a mode choice analysis to compute the demand for commercial airline travel based upon the traveler s purpose of the trip, value of time, cost and time of the trip,. The county demand for airline travel is then aggregated (or distributed) to the airport level, and the enplanement demand at commercial airports is modeled. With the growth in flight demand, and utilizing current airline flight schedules, the Fratar algorithm is used to develop future flight schedules in the NAS. The projected flights can then be flown through air transportation simulators to quantify the ability of the NAS to meet future demand. A major strength of the TSAM analysis is that scenario planning can be conducted to quantify capacity requirements at individual airports, based upon different future scenarios. Different demographic scenarios can be analyzed to model the demand sensitivity to them. Also, it is fairly well know, but not well modeled at the airport level, that the demand for travel is highly dependent on the cost of travel, or the fare yield of the airline industry. The FAA projects the fare yield (in constant year dollars) to keep decreasing into the future. The magnitude and/or direction of these projections can be suspect in light of the general lack of airline profits and the large rises in airline fuel cost. Also, changes in travel time and convenience have an influence on the demand for air travel, especially for business travel. Future planners cannot easily conduct sensitivity studies of future demand with the FAA TAF data, nor with the Boeing or Airbus projections. In TSAM many factors can be parameterized and various demand sensitivities can be predicted for future travel. These

The Number Density Evolution of Extreme Emission Line Galaxies in 3D-HST: Results from a Novel Automated Line Search Technique for Slitless Spectroscopy

NASA Astrophysics Data System (ADS)

Maseda, Michael V.; van der Wel, Arjen; Rix, Hans-Walter; Momcheva, Ivelina; Brammer, Gabriel B.; Franx, Marijn; Lundgren, Britt F.; Skelton, Rosalind E.; Whitaker, Katherine E.

2018-02-01

The multiplexing capability of slitless spectroscopy is a powerful asset in creating large spectroscopic data sets, but issues such as spectral confusion make the interpretation of the data challenging. Here we present a new method to search for emission lines in the slitless spectroscopic data from the 3D-HST survey utilizing the Wide-Field Camera 3 on board the Hubble Space Telescope. Using a novel statistical technique, we can detect compact (extended) emission lines at 90% completeness down to fluxes of 1.5(3.0)× {10}-17 {erg} {{{s}}}-1 {{cm}}-2, close to the noise level of the grism exposures, for objects detected in the deep ancillary photometric data. Unlike previous methods, the Bayesian nature allows for probabilistic line identifications, namely redshift estimates, based on secondary emission line detections and/or photometric redshift priors. As a first application, we measure the comoving number density of Extreme Emission Line Galaxies (restframe [O III] λ5007 equivalent widths in excess of 500 Å). We find that these galaxies are nearly 10× more common above z ∼ 1.5 than at z ≲ 0.5. With upcoming large grism surveys such as Euclid and WFIRST, as well as grisms featured prominently on the NIRISS and NIRCam instruments on the James Webb Space Telescope, methods like the one presented here will be crucial for constructing emission line redshift catalogs in an automated and well-understood manner. This work is based on observations taken by the 3D-HST Treasury Program and the CANDELS Multi-Cycle Treasury Program with the NASA/ESA HST, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Implementation of NAS Parallel Benchmarks in Java

NASA Technical Reports Server (NTRS)

Frumkin, Michael; Schultz, Matthew; Jin, Hao-Qiang; Yan, Jerry

2000-01-01

A number of features make Java an attractive but a debatable choice for High Performance Computing (HPC). In order to gauge the applicability of Java to the Computational Fluid Dynamics (CFD) we have implemented NAS Parallel Benchmarks in Java. The performance and scalability of the benchmarks point out the areas where improvement in Java compiler technology and in Java thread implementation would move Java closer to Fortran in the competition for CFD applications.

MPI, HPF or OpenMP: A Study with the NAS Benchmarks

NASA Technical Reports Server (NTRS)

Jin, Hao-Qiang; Frumkin, Michael; Hribar, Michelle; Waheed, Abdul; Yan, Jerry; Saini, Subhash (Technical Monitor)

1999-01-01

Porting applications to new high performance parallel and distributed platforms is a challenging task. Writing parallel code by hand is time consuming and costly, but the task can be simplified by high level languages and would even better be automated by parallelizing tools and compilers. The definition of HPF (High Performance Fortran, based on data parallel model) and OpenMP (based on shared memory parallel model) standards has offered great opportunity in this respect. Both provide simple and clear interfaces to language like FORTRAN and simplify many tedious tasks encountered in writing message passing programs. In our study we implemented the parallel versions of the NAS Benchmarks with HPF and OpenMP directives. Comparison of their performance with the MPI implementation and pros and cons of different approaches will be discussed along with experience of using computer-aided tools to help parallelize these benchmarks. Based on the study,potentials of applying some of the techniques to realistic aerospace applications will be presented

MPI, HPF or OpenMP: A Study with the NAS Benchmarks

NASA Technical Reports Server (NTRS)

Jin, H.; Frumkin, M.; Hribar, M.; Waheed, A.; Yan, J.; Saini, Subhash (Technical Monitor)

1999-01-01

Porting applications to new high performance parallel and distributed platforms is a challenging task. Writing parallel code by hand is time consuming and costly, but this task can be simplified by high level languages and would even better be automated by parallelizing tools and compilers. The definition of HPF (High Performance Fortran, based on data parallel model) and OpenMP (based on shared memory parallel model) standards has offered great opportunity in this respect. Both provide simple and clear interfaces to language like FORTRAN and simplify many tedious tasks encountered in writing message passing programs. In our study, we implemented the parallel versions of the NAS Benchmarks with HPF and OpenMP directives. Comparison of their performance with the MPI implementation and pros and cons of different approaches will be discussed along with experience of using computer-aided tools to help parallelize these benchmarks. Based on the study, potentials of applying some of the techniques to realistic aerospace applications will be presented.

Discovery of Massive, Mostly Star Formation Quenched Galaxies with Extremely Large Lyα Equivalent Widths at z ˜ 3

NASA Astrophysics Data System (ADS)

Taniguchi, Yoshiaki; Kajisawa, Masaru; Kobayashi, Masakazu A. R.; Nagao, Tohru; Shioya, Yasuhiro; Scoville, Nick Z.; Sanders, David B.; Capak, Peter L.; Koekemoer, Anton M.; Toft, Sune; McCracken, Henry J.; Le Fèvre, Olivier; Tasca, Lidia; Sheth, Kartik; Renzini, Alvio; Lilly, Simon; Carollo, Marcella; Kovač, Katarina; Ilbert, Olivier; Schinnerer, Eva; Fu, Hai; Tresse, Laurence; Griffiths, Richard E.; Civano, Francesca

2015-08-01

We report a discovery of six massive galaxies with both extremely large Lyα equivalent widths (EWs) and evolved stellar populations at z ˜ 3. These MAssive Extremely STrong Lyα emitting Objects (MAESTLOs) have been discovered in our large-volume systematic survey for strong Lyα emitters (LAEs) with 12 optical intermediate-band data taken with Subaru/Suprime-Cam in the COSMOS field. Based on the spectral energy distribution fitting analysis for these LAEs, it is found that these MAESTLOs have (1) large rest-frame EWs of EW0 (Lyα) ˜ 100-300 Å, (2) M⋆ ˜ 1010.5-1011.1 M⊙, and (3) relatively low specific star formation rates of SFR/M⋆ ˜ 0.03-1 Gyr-1. Three of the six MAESTLOs have extended Lyα emission with a radius of several kiloparsecs, although they show very compact morphology in the HST/ACS images, which correspond to the rest-frame UV continuum. Since the MAESTLOs do not show any evidence for active galactic nuclei, the observed extended Lyα emission is likely to be caused by a star formation process including the superwind activity. We suggest that this new class of LAEs, MAESTLOs, provides a missing link from star-forming to passively evolving galaxies at the peak era of the cosmic star formation history. Based on observations with NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555; also based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan; and also based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under ESO programme ID 179.A-2005 and on data products produced by TERAPIX and the Cambridge Astronomy Survey Unit on behalf of the UltraVISTA consortium.

75 FR 33615 - Draft EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments (EPA...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-14

... the IRIS Program, EPA provides the highest quality science-based human health assessments to support... comments included in the National Academy of Sciences (NAS) 2006 report. In addition, it includes new analyses on potential human effects that may result from exposure to 2,3,7,8- tetrachlorodibenzo-p-dioxin...

Are Ultra-faint Galaxies at z = 6-8 Responsible for Cosmic Reionization? Combined Constraints from the Hubble Frontier Fields Clusters and Parallels

NASA Astrophysics Data System (ADS)

Atek, Hakim; Richard, Johan; Jauzac, Mathilde; Kneib, Jean-Paul; Natarajan, Priyamvada; Limousin, Marceau; Schaerer, Daniel; Jullo, Eric; Ebeling, Harald; Egami, Eiichi; Clement, Benjamin

2015-11-01

the epoch of reionization, paving the way to more ambitious programs using cosmic telescopes with the next generation of large aperture telescopes such as the James Webb Space Telescope and the European Extremely Large Telescope. Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs 13495, 11386, 13389, and 11689. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. The Hubble Frontier Fields data and the lens models were obtained from the Mikulski Archive for Space Telescopes (MAST). This work utilizes gravitational lensing models produced by PIs Ebeling, Merten, and Zitrin, funded as part of the HST Frontier Fields program conducted by STScI.

NAS technical summaries. Numerical aerodynamic simulation program, March 1992 - February 1993

NASA Technical Reports Server (NTRS)

1994-01-01

NASA created the Numerical Aerodynamic Simulation (NAS) Program in 1987 to focus resources on solving critical problems in aeroscience and related disciplines by utilizing the power of the most advanced supercomputers available. The NAS Program provides scientists with the necessary computing power to solve today's most demanding computational fluid dynamics problems and serves as a pathfinder in integrating leading-edge supercomputing technologies, thus benefitting other supercomputer centers in government and industry. The 1992-93 operational year concluded with 399 high-speed processor projects and 91 parallel projects representing NASA, the Department of Defense, other government agencies, private industry, and universities. This document provides a glimpse at some of the significant scientific results for the year.

NAS technical summaries: Numerical aerodynamic simulation program, March 1991 - February 1992

NASA Technical Reports Server (NTRS)

1992-01-01

NASA created the Numerical Aerodynamic Simulation (NAS) Program in 1987 to focus resources on solving critical problems in aeroscience and related disciplines by utilizing the power of the most advanced supercomputers available. The NAS Program provides scientists with the necessary computing power to solve today's most demanding computational fluid dynamics problems and serves as a pathfinder in integrating leading-edge supercomputing technologies, thus benefiting other supercomputer centers in Government and industry. This report contains selected scientific results from the 1991-92 NAS Operational Year, March 4, 1991 to March 3, 1992, which is the fifth year of operation. During this year, the scientific community was given access to a Cray-2 and a Cray Y-MP. The Cray-2, the first generation supercomputer, has four processors, 256 megawords of central memory, and a total sustained speed of 250 million floating point operations per second. The Cray Y-MP, the second generation supercomputer, has eight processors and a total sustained speed of one billion floating point operations per second. Additional memory was installed this year, doubling capacity from 128 to 256 megawords of solid-state storage-device memory. Because of its higher performance, the Cray Y-MP delivered approximately 77 percent of the total number of supercomputer hours used during this year.

UAS in the NAS Air Traffic Controller Acceptability Study-1: The Effects of Horizontal Miss Distances on Simulated UAS and Manned Aircraft Encounters

NASA Technical Reports Server (NTRS)

Ghatas, Rania W.; Comstock, James R., Jr.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

2015-01-01

This study examined air traffic controller acceptability ratings based on the effects of differing horizontal miss distances (HMDs) for encounters between UAS and manned aircraft. In a simulation of the Dallas/Fort Worth (DFW) East-side airspace, the CAS-1 experiment at NASA Langley Research Center enlisted fourteen recently retired DFW air traffic controllers to rate well-clear volumes based on differing HMDs that ranged from 0.5 NM to 3.0 NM. The controllers were tasked with rating these HMDs from "too small" to "too excessive" on a defined, 1-5, scale and whether these distances caused any disruptions to the controller and/or to the surrounding traffic flow. Results of the study indicated a clear favoring towards a particular HMD range. Controller workload was also measured. Data from this experiment and subsequent experiments will play a crucial role in the FAA's establishment of rules, regulations, and procedures to safely and efficiently integrate UAS into the NAS.

Design handbook : energy efficiency and water conservation in NAS facilities

DOT National Transportation Integrated Search

1997-09-30

This handbook was created to provide definitive energy efficiency and water conservation design criteria for the design of NAS facilities. FAA-HDBK-001 provides implementation strategies and tools to comply with E.O. 12902, Energy and Water Conservat...

Benefits of a Unified LaSRS++ Simulation for NAS-Wide and High-Fidelity Modeling

NASA Technical Reports Server (NTRS)

Glaab, Patricia; Madden, Michael

2014-01-01

The LaSRS++ high-fidelity vehicle simulation was extended in 2012 to support a NAS-wide simulation mode. Since the initial proof-of-concept, the LaSRS++ NAS-wide simulation is maturing into a research-ready tool. A primary benefit of this new capability is the consolidation of the two modeling paradigms under a single framework to save cost, facilitate iterative concept testing between the two tools, and to promote communication and model sharing between user communities at Langley. Specific benefits of each type of modeling are discussed along with the expected benefits of the unified framework. Current capability details of the LaSRS++ NAS-wide simulations are provided, including the visualization tool, live data interface, trajectory generators, terminal routing for arrivals and departures, maneuvering, re-routing, navigation, winds, and turbulence. The plan for future development is also described.

Multiple assembly chaperones govern biogenesis of the proteasome regulatory particle base.

PubMed

Funakoshi, Minoru; Tomko, Robert J; Kobayashi, Hideki; Hochstrasser, Mark

2009-05-29

The central protease of eukaryotes, the 26S proteasome, has a 20S proteolytic core particle (CP) and an attached 19S regulatory particle (RP). The RP is further subdivided into lid and base subcomplexes. Little is known about RP assembly. Here, we show that four conserved assembly factors govern biogenesis of the yeast RP base. Nas2 forms a complex with the Rpt4 and Rpt5 ATPases and enhances 26S proteasome formation in vivo and in vitro. Other RP subcomplexes contain Hsm3, which is related to mammalian proteasome subunit S5b. Hsm3 also contributes to base assembly. Larger Hsm3-containing complexes include two additional proteins, Nas6 and Rpn14, which function as assembly chaperones as well. Specific deletion combinations affecting these four factors cause severe perturbations to RP assembly. Our results demonstrate that proteasomal RP biogenesis requires multiple, functionally overlapping chaperones and suggest a model in which subunits form specific subcomplexes that then assemble into the base.

NICMOS Coronagraphic Imaging of a Circumstellar Disk around the T Tauri Star GM Aurigae

NASA Astrophysics Data System (ADS)

Koerner, D. W.; Schneider, G.; Smith, B. A.; Becklin, E. E.; Hines, D. C.; Kirkpatrick, J. D.; Lowrance, P. J.; Meier, R.; Reike, M.; Terrile, R. J.; Thompson, R. I.; NICMOS/IDT EONS Teams

1998-12-01

We have carried out a coronagraphic imaging study of circumstellar disk candidates as part of NICMOS IDT investigations of the environments of nearby stars. Here we present images of circumstellar nebulosity around the classical T Tauri star, GM Aurigae, at lambda = 1.1 and 1.6 mu m. The emission extends beyond 2.8'' (450 AU) from the star with brightness falling off radially as R(-2.5) . The flux ratio between the two wavelengths differs little from that expected for a K5 star like GM Aur, suggesting that scattering grains include a substantial population with sizes larger than 1 mu m. Preliminary modeling of the emission confirms its origin in stellar light reflected off the surface of a flared circumstellar disk and indicates an inclination 60(deg) from face on. These results agree well with the appearance of CO(2->1) emission in aperture synthesis images from the Owens Valley Millimeter Array, and with the morphology of optical nebulosity in psf-subtracted exposures taken by the WFPC2 science team. Further, the high-resolution constraint on size and orientation enables a definitive interpretation of the velocity structure from kinematic modeling of CO(2->1) images at lower resolution: it is demonstrated unequivocally that the gas is centrifugally supported and in Keplerian rotation within the confines of a disk centered on the star. This work is supported by NASA grant NAG 5-3042, and 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.

UAS Integration in the NAS Project - FY 14 Annual Review

NASA Technical Reports Server (NTRS)

Grindle, Laurie; Randall, Debra; Hackenberg, Davis

2014-01-01

This briefing gives insight into the research activities and efforts being executed in order to integrate unmanned aircraft systems into the national airspace system. This briefing is to inform others of the UAS-NAS Projects progress and future directions.

DOE Radiation Research Program is floundering - NAS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lobsenz, G.

1994-04-20

The Energy Department's radiation health effects research program is floundering in a morass of administrative confusion due to an ill-considered 1990 joint management agreement between DOE and the Health and Human Services Department, a National Academy of Sciences panel says. The NAS panel said the [open quotes]administrative difficulties[close quotes] created by the DOE-HHS agreement appear to be [open quotes]stifling creativity and efficiency within DOE's Epidemiology Research Program, delaying the completion and publication of research.[close quotes] The panel also expressed concern that DOE has failed to adequately fund or staff its health research office, and that the department had no mastermore » research plan to identify research needs or set forth uniform, scientifically rigorous data collection procedures. The panel said DOE's lack of commitment was particularly evident in its failure to set up an effective health surveillance program for its nuclear work force. In addition, the panel said DOE had fallen short on promises to create a comprehensive computer bank of health research data that would be continually updated with new information gleaned from an ongoing worker surveillance program. While recommending enhancements, the NAS panel emphasized that DOE's health research program would not be able to function effectively until the department revamped its joint management agreement with HHS.« less

Morphology of AGN in the Central Kiloparsec

NASA Astrophysics Data System (ADS)

Martini, Paul

Hubble Space Telescope observations of the central kiloparsec of AGN have revealed a wealth of structure, particularly nuclear bars and spirals, that are distinct from analogous features in the disks of spiral galaxies. WFPC2 and NICMOS images of a large sample of AGN observed at high spatial resolution make it possible to quantify the frequency and detailed properties of these structures. Nearly all AGN have nuclear spiral dust lanes in the central kiloparsec, while only a small minority contain nuclear bars. If these nuclear dust spirals trace shocks in the circumnuclear, gaseous disks, they may dissipate sufficient angular momentum to fuel the active nucleus. I would like to thank my collaborators in this project---Rick Pogge, John Mulchaey, and Mike Regan---for allowing me to present this work in advance of publication, as well as Johan Knapen for organizing such an interesting meeting. Support for this work was provided by NASA through grant numbers GO-7867 and GO-8597 from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Meeting of Experts on NASA's Unmanned Aircraft System (UAS) Integration in the National Airspace Systems (NAS) Project

NASA Technical Reports Server (NTRS)

Wolfe, Jean; Bauer, Jeff; Bixby, C.J.; Lauderdale, Todd; Shively, Jay; Griner, James; Hayhurst, Kelly

2010-01-01

Topics discussed include: Aeronautics Research Mission Directorate Integrated Systems Research Program (ISRP) and UAS Integration in the NAS Project; UAS Integration into the NAS Project; Separation Assurance and Collision Avoidance; Pilot Aircraft Interface Objectives/Rationale; Communication; Certification; and Integrated Tests and Evaluations.

QNAP 1263U Network Attached Storage (NAS)/ Storage Area Network (SAN) Device Users Guide

DTIC Science & Technology

2016-11-01

standard Ethernet network. Operating either a NAS or SAN is vital for the integrity of the data stored on the drives found in the device. Redundant...speed of the network itself. Many standards are in place for transferring data, including more standard ones such as File Transfer Protocol and Server ...following are the procedures for connecting to the NAS administrative web page: 1) Open a web browser and browse to 192.168.40.8:8080. 2) Enter the

Implementation of the NAS Parallel Benchmarks in Java

NASA Technical Reports Server (NTRS)

Frumkin, Michael A.; Schultz, Matthew; Jin, Haoqiang; Yan, Jerry; Biegel, Bryan (Technical Monitor)

2002-01-01

Several features make Java an attractive choice for High Performance Computing (HPC). In order to gauge the applicability of Java to Computational Fluid Dynamics (CFD), we have implemented the NAS (NASA Advanced Supercomputing) Parallel Benchmarks in Java. The performance and scalability of the benchmarks point out the areas where improvement in Java compiler technology and in Java thread implementation would position Java closer to Fortran in the competition for CFD applications.

The Star Formation History of the Very Metal-poor Blue Compact Dwarf I Zw 18 from HST/ACS Data

NASA Astrophysics Data System (ADS)

Annibali, F.; Cignoni, M.; Tosi, M.; van der Marel, R. P.; Aloisi, A.; Clementini, G.; Contreras Ramos, R.; Fiorentino, G.; Marconi, M.; Musella, I.

2013-12-01

We have derived the star formation history (SFH) of the blue compact dwarf galaxy I Zw 18 through comparison of deep HST/ACS data with synthetic color-magnitude diagrams (CMDs). A statistical analysis was implemented for the identification of the best-fit SFH and relative uncertainties. We confirm that I Zw 18 is not a truly young galaxy, having started forming stars earlier than ~1 Gyr ago, and possibly at epochs as old as a Hubble time. In I Zw 18's main body we infer a lower limit of ≈2 × 106 M ⊙ for the mass locked up in old stars. I Zw 18's main body has been forming stars very actively during the last ~10 Myr, with an average star formation rate (SFR) as high as ≈1 M ⊙ yr-1 (or ≈2 × 10-5 M ⊙ yr-1 pc-2). On the other hand, the secondary body was much less active at these epochs, in agreement with the absence of significant nebular emission. The high current SFR can explain the very blue colors and the high ionized gas content in I Zw 18, resembling primeval galaxies in the early universe. Detailed chemical evolution models are required to quantitatively check whether the SFH from the synthetic CMDs can explain the low measured element abundances, or if galactic winds with loss of metals are needed. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., for NASA under contract NAS5-26555.

Hubble Space Telescope Constraints on the Winds and Astrospheres of Red Giant Stars

NASA Astrophysics Data System (ADS)

Wood, Brian E.; Müller, Hans-Reinhard; Harper, Graham M.

2016-10-01

We report on an ultraviolet spectroscopic survey of red giants observed by the Hubble Space Telescope, focusing on spectra of the Mg II h and k lines near 2800 Å in order to study stellar chromospheric emission, winds, and astrospheric absorption. We focus on spectral types between K2 III and M5 III, a spectral type range with stars that are noncoronal, but possessing strong, chromospheric winds. We find a very tight relation between Mg II surface flux and photospheric temperature, supporting the notion that all K2-M5 III stars are emitting at a basal flux level. Wind velocities (V w ) are generally found to decrease with spectral type, with V w decreasing from ˜40 km s-1 at K2 III to ˜20 km s-1 at M5 III. We find two new detections of astrospheric absorption, for σ Pup (K5 III) and γ Eri (M1 III). This absorption signature had previously only been detected for α Tau (K5 III). For the three astrospheric detections, the temperature of the wind after the termination shock (TS) correlates with V w , but is lower than predicted by the Rankine-Hugoniot shock jump conditions, consistent with the idea that red giant TSs are radiative shocks rather than simple hydrodynamic shocks. A full hydrodynamic simulation of the γ Eri astrosphere is provided to explore this further. Based on observations made 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 NAS 5-26555. These observations are associated with program GO-13462. This paper also presents observations obtained with the Harlan J. Smith Telescope at McDonald Observatory of the University of Texas at Austin.

Unstructured Adaptive (UA) NAS Parallel Benchmark. Version 1.0

NASA Technical Reports Server (NTRS)

Feng, Huiyu; VanderWijngaart, Rob; Biswas, Rupak; Mavriplis, Catherine

2004-01-01

We present a complete specification of a new benchmark for measuring the performance of modern computer systems when solving scientific problems featuring irregular, dynamic memory accesses. It complements the existing NAS Parallel Benchmark suite. The benchmark involves the solution of a stylized heat transfer problem in a cubic domain, discretized on an adaptively refined, unstructured mesh.

UAS Integration in the NAS Project: Integrated Test and Evaluation (IT&E) Flight Test 3. Revision E

NASA Technical Reports Server (NTRS)

Marston, Michael

2015-01-01

The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration into the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability, Human Systems Integration (HSI), and Communication to support reducing the barriers of UAS access to the NAS. This research is broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Sense and Avoid (SAA) performance standards, command and control performance standards, and human systems integration. The focus of Test Infrastructure is to enable development and validation of airspace integration procedures and performance standards, including the integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project will develop an adaptable, scalable, and schedulable relevant test environment capable of evaluating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project will conduct a series of Human-in-the-Loop and Flight Test activities that integrate key concepts, technologies and/or procedures in a relevant air traffic environment. Each of the integrated events will build on the technical achievements, fidelity and complexity of the previous tests and

Compositional dependence of the band gap in Ga(NAsP) quantum well heterostructures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jandieri, K., E-mail: kakhaber.jandieri@physik.uni-marburg.de; Ludewig, P.; Wegele, T.

We present experimental and theoretical studies of the composition dependence of the direct band gap energy in Ga(NAsP)/GaP quantum well heterostructures grown on either (001) GaP- or Si-substrates. The theoretical description takes into account the band anti-crossing model for the conduction band as well as the modification of the valence subband structure due to the strain resulting from the pseudomorphic epitaxial growth on the respective substrate. The composition dependence of the direct band gap of Ga(NAsP) is obtained for a wide range of nitrogen and phosphorus contents relevant for laser applications on Si-substrate.

A Hubble Space Telescope Survey for Novae in M87. I. Light and Color Curves, Spatial Distributions, and the Nova Rate

NASA Astrophysics Data System (ADS)

Shara, Michael M.; Doyle, Trisha F.; Lauer, Tod R.; Zurek, David; Neill, J. D.; Madrid, Juan P.; Mikołajewska, Joanna; Welch, D. L.; Baltz, Edward A.

2016-11-01

The Hubble Space Telescope has imaged the central part of M87 over a 10 week span, leading to the discovery of 32 classical novae (CNe) and nine fainter, likely very slow, and/or symbiotic novae. In this first paper of a series, we present the M87 nova finder charts, and the light and color curves of the novae. We demonstrate that the rise and decline times, and the colors of M87 novae are uncorrelated with each other and with position in the galaxy. The spatial distribution of the M87 novae follows the light of the galaxy, suggesting that novae accreted by M87 during cannibalistic episodes are well-mixed. Conservatively using only the 32 brightest CNe we derive a nova rate for M87: {363}-45+33 novae yr‑1. We also derive the luminosity-specific classical nova rate for this galaxy, which is {7.88}-2.6+2.3 {yr}}-1/{10}10 {L}ȯ {,}K. Both rates are 3–4 times higher than those reported for M87 in the past, and similarly higher than those reported for all other galaxies. We suggest that most previous ground-based surveys for novae in external galaxies, including M87, miss most faint, fast novae, and almost all slow novae near the centers of galaxies. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

Self-assembled GaInNAs/GaAsN quantum dot lasers: solid source molecular beam epitaxy growth and high-temperature operation

PubMed Central

Liu, CY; Sun, ZZ; Yew, KC

2006-01-01

Self-assembled GaInNAs quantum dots (QDs) were grown on GaAs (001) substrate using solid-source molecular-beam epitaxy (SSMBE) equipped with a radio-frequency nitrogen plasma source. The GaInNAs QD growth characteristics were extensively investigated using atomic-force microscopy (AFM), photoluminescence (PL), and transmission electron microscopy (TEM) measurements. Self-assembled GaInNAs/GaAsN single layer QD lasers grown using SSMBE have been fabricated and characterized. The laser worked under continuous wave (CW) operation at room temperature (RT) with emission wavelength of 1175.86 nm. Temperature-dependent measurements have been carried out on the GaInNAs QD lasers. The lowest obtained threshold current density in this work is ∼1.05 kA/cm2from a GaInNAs QD laser (50 × 1,700 µm2) at 10 °C. High-temperature operation up to 65 °C was demonstrated from an unbonded GaInNAs QD laser (50 × 1,060 µm2), with high characteristic temperature of 79.4 K in the temperature range of 10–60 °C.

Remotely Operated Aircraft (ROA) Impact on the National Airspace System (NAS) Work Package, 2005: Composite Report on FAA Flight Plan and Operational Evaluation Plan. Version 7.0

NASA Technical Reports Server (NTRS)

2005-01-01

The purpose of this document is to present the findings that resulted from a high-level analysis and evaluation of the following documents: (1) The OEP (Operational Evolution Plan) Version 7 -- a 10-year plan for operational improvements to increase capacity and efficiency in U.S. air travel and transport and other use of domestic airspace. The OEP is the FAA commitment to operational improvements. It is outcome driven, with clear lines of accountability within FAA organizations. The OEP concentrates on operational solutions and integrates safety, certification, procedures, staffing, equipment, avionics and research; (2) The Draft Flight Plan 2006 through 2010 -- a multi-year strategic effort, setting a course for the FAA through 2001, to provide the safest and most efficient air transportation system in the world; (3) The NAS System Architecture Version 5 -- a blueprint for modernizing the NAS and improving NAS services and capabilities through the year 2015; and (4) The NAS-SR-1000 System Requirements Specification (NASSRS) -- a compilation of requirements which describe the operational capabilities for the NAS. The analysis is particularly focused on examining the documents for relevance to existing and/or planned future UAV operations. The evaluation specifically focuses on potential factors that could materially affect the development of a commercial ROA industry, such as: (1) Design limitations of the CNS/ATM system, (2) Human limitations, The information presented was taken from program specifications or program office lead personnel.

Kinematics and Optical Depth in the Green Peas: Suppressed Superwinds in Candidate LyC Emitters

NASA Astrophysics Data System (ADS)

Jaskot, Anne E.; Oey, M. S.; Scarlata, Claudia; Dowd, Tara

2017-12-01

By clearing neutral gas away from a young starburst, superwinds may regulate the escape of Lyman continuum (LyC) photons from star-forming galaxies. However, models predict that superwinds may not launch in the most extreme, compact starbursts. We explore the role of outflows in generating low optical depths in the Green Peas (GPs), the only known star-forming population with several confirmed and candidate LyC-leaking galaxies. With Hubble Space Telescope UV spectra of 25 low-redshift GPs, including new observations of 13 of the most highly ionized GPs, we compare the kinematics of UV absorption lines with indirect H I optical depth diagnostics: Lyα escape fraction, Lyα peak separation, or low-ionization absorption line equivalent width. The data suggest that high-ionization kinematics tracing superwind activity may correlate with low optical depth in some objects. However, the most extreme GPs, including many of the best candidate LyC emitters with weak low-ionization absorption and strong, narrow Lyα profiles, show the lowest velocities. These results are consistent with models for suppressed superwinds, which suggests that outflows may not be the only cause of LyC escape from galaxies. Based on observations made 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 NAS-5-26555. These observations are associated with programs GO-14080, GO-13293, and GO-12928.

The Three-Dimensional Morphology of VY Canis Majoris. I. The Kinematics of the Ejecta

NASA Astrophysics Data System (ADS)

Humphreys, Roberta M.; Helton, L. Andrew; Jones, Terry J.

2007-06-01

Images of the complex circumstellar nebula associated with the famous red supergiant VY CMa show evidence for multiple and asymmetric mass-loss events over the past 1000 yr. Doppler velocities of the arcs and knots in the ejecta show that they are not only spatially distinct but also kinematically separate from the surrounding diffuse material. In this paper we describe second-epoch HST WFPC2 images to measure the transverse motions, which when combined with the radial motions provide a complete picture of the kinematics of the ejecta, including the total space motions and directions of the outflows. Our results show that the arcs and clumps of knots are moving at different velocities, in different directions, and at different angles relative to the plane of the sky and to the star, confirming their origin from eruptions at different times and from physically separate regions on the star. We conclude that the morphology and kinematics of the arcs and knots are consistent with a history of mass ejections not aligned with any presumed axis of symmetry. The arcs and clumps represent relatively massive outflows and ejections of gas very likely associated with large-scale convective activity and magnetic fields. 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 NAS 5-26555.

Analysis of Co-spatial UV-optical HST/STIS Spectra of Planetary Nebula NGC 3242

NASA Astrophysics Data System (ADS)

Miller, Timothy R.; Henry, Richard B. C.; Balick, Bruce; Kwitter, Karen B.; Dufour, Reginald J.; Shaw, Richard A.; Corradi, Romano L. M.

2016-10-01

This project sought to consider two important aspects of the planetary nebula NGC 3242 using new long-slit HST/STIS spectra. First, we investigated whether this object is chemically homogeneous by spatially dividing the slit into different regions and calculating the abundances of each region. The major result is that the elements of He, C, O, and Ne are chemically homogeneous within uncertainties across the regions probed, implying that the stellar outflow was well-mixed. Second, we constrained the stellar properties using photoionization models computed by CLOUDY and tested the effects of three different density profiles on these parameters. The three profiles tested were a constant density profile, a Gaussian density profile, and a Gaussian with a power-law density profile. The temperature and luminosity were not affected significantly by the choice of density structure. The values for the stellar temperature and luminosity from our best-fit model are {89.7}-4.7+7.3 kK and log(L/L ⊙) = {3.36}-0.22+0.28, respectively. Comparing to evolutionary models on an HR diagram, this corresponds to an initial and final mass of {0.95}-0.09+0.35{M}⊙ and {0.56}-0.01+0.01{M}⊙ , respectively. 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, Incorporated, under NASA contract NAS5-26555.

UAS-NAS Project Demo - Mini HITL Week 2 Stats

NASA Technical Reports Server (NTRS)

Murphy, James R.; Fern, Lisa C.; Rorie, Robert C.; Shively, Robert; Jovic, Srboljub

2016-01-01

The UAS-NAS Project demo will showcase recent research efforts to ensure the interoperability between proposed UAS detect and avoid (DAA) human machine interface requirements (developed within RTCA SC-228) and existing collision avoidance displays. Attendees will be able to view the current state of the art of the DAA pilot traffic, alerting and guidance displays integrated with Traffic advisory and Collision Avoidance (TCAS) II in the UAS-NAS Project's research UAS ground control station (developed in partnership with the Air Force Research Laboratory). In addition, attendees will have the opportunity to interact with the research UAS ground control station and "fly" encounters, using the DAA and TCAS II displays to avoid simulated aircraft. The display of the advisories will be hosted on a laptop with an external 30" monitor, running the Vigilant Spirit system. DAA advisories will be generated by the JADEM software tool, connected to the system via the LVC Gateway. A repeater of the primary flight display will be shown on a 55" monitor mounted on a stand at the back of the booth to show the pilot interaction to the passersby.

Greenhouse policy study from NAS

NASA Astrophysics Data System (ADS)

Maggs, William Ward

The National Academy of Sciences will produce a study for the Environmental Protection Agency on policy responses to global warming. The report is due out before the end of 1990.Dan J. Evans, former U.S. Senator and former Governor of Washington, will chair a panel of the Commission on Science, Engineering, and Public Policy, a body of the councils of the NAS, National Academy of Engineering, and Institute of Medicine. Evans is a registered civil engineer and previously chaired the Pacific Northwest Electric Power and Conservation Planning Council.The 13-person panel includes AGU members Stephen Schneider of the National Center for Atmospheric Research and Robert Frosch, Vice President of Research Laboratores at General Motors Corp., Jessica Mathews, Vice President of the World Resources Institute, and Sir Crispin Tickell, the United Kingdom's Ambassador to the United Nations.

Communications for UAS Integration in the NAS Phase 2 - Satellite Communications and Terrestrial Extension

NASA Technical Reports Server (NTRS)

Griner, James H.; Kerczewski, Robert J.

2017-01-01

In order to provide for the safe integration of unmanned aircraft systems (UAS) into the National Airspace System, the command and control communications link connecting the ground-based pilot with the unmanned aircraft must be highly reliable and robust, with national and international standards to enable interoperability and certification. Both line-of-sight (LOS) links using terrestrial-based communications and beyond-line-of-sight (BLOS) links using satellite communications, supported by national and international standards, are required for integrated UAS operations. The National Aeronautics and Space Administration (NASA) has undertaken an extensive technology development and test program in order to provide the required technical data needed to enable C2 standards development. NASAs UAS Integration in the National Airspace System (NAS), or UAS in the NAS Project, included as a major element the Command and Control Communications (C2) Subproject, based at NASAs Glenn Research Center. The successful first phase of the C2 Subproject, completed during 2012-2016, focused primarily on line-of-sight communications. Accomplishments included air-ground channel propagation characterization and modeling; CNPC prototype radio development; CNPC radio flight testing; satellite communications spectrum study and interference analysis; and development of C2 LOS communications standards development. The second phase of the C2 Subproject will focus primarily on beyond-line-of-sight communications, although a follow-on activity for terrestrial LOS communications, known as Terrestrial Extension, is also included. In addition to the terrestrial element, Phase 2 also includes technology development and testing activities for Ka-Band BLOS C2 Satellite Communications; Ku-Band BLOS C2 Satellite Communications; Ku-Band Interference and Propagation; and C-Band Satellite Communications. This paper will provide brief overviews of the C2 Subproject and its Phase I accomplishments

Communications for UAS Integration in the NAS Phase 2 Satellite Communications and Terrestrial Extension

NASA Technical Reports Server (NTRS)

Griner, Jim; Kerczewski, Bob

2017-01-01

In order to provide for the safe integration of unmanned aircraft systems (UAS) into the National Airspace System, the command and control communications link connecting the ground-based pilot with the unmanned aircraft must be highly reliable and robust, with national and international standards to enable interoperability and certification. Both line-of-sight (LOS) links using terrestrial-based communications and beyond-line-of-sight (BLOS) links using satellite communications, supported by national and international standards, are required for integrated UAS operations. The National Aeronautics and Space Administration (NASA) has undertaken an extensive technology development and test program in order to provide the required technical data needed to enable C2 standards development. NASAs UAS Integration in the National Airspace System (NAS), or UAS in the NAS Project, included as a major element the Command and Control Communications (C2) Subproject, based at NASAs Glenn Research Center. The successful first phase of the C2 Subproject, completed during 2012-2016, focused primarily on line-of-sight communications. Accomplishments included air-ground channel propagation characterization and modeling; CNPC prototype radio development; CNPC radio flight testing; satellite communications spectrum study and interference analysis; and development of C2 LOS communications standards development. The second phase of the C2 Subproject will focus primarily on beyond-line-of-sight communications, although a follow-on activity for terrestrial LOS communications, known as Terrestrial Extension, is also included. In addition to the terrestrial element, Phase 2 also includes technology development and testing activities for Ka-Band BLOS C2 Satellite Communications; Ku-Band BLOS C2 Satellite Communications; Ku-Band Interference and Propagation; and C-Band Satellite Communications. This paper will provide brief overviews of the C2 Subproject and its Phase I accomplishments

Differential stabilities and sequence-dependent base pair opening dynamics of Watson-Crick base pairs with 5-hydroxymethylcytosine, 5-formylcytosine, or 5-carboxylcytosine.

PubMed

Szulik, Marta W; Pallan, Pradeep S; Nocek, Boguslaw; Voehler, Markus; Banerjee, Surajit; Brooks, Sonja; Joachimiak, Andrzej; Egli, Martin; Eichman, Brandt F; Stone, Michael P

2015-02-10

5-Hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC) form during active demethylation of 5-methylcytosine (5mC) and are implicated in epigenetic regulation of the genome. They are differentially processed by thymine DNA glycosylase (TDG), an enzyme involved in active demethylation of 5mC. Three modified Dickerson-Drew dodecamer (DDD) sequences, amenable to crystallographic and spectroscopic analyses and containing the 5'-CG-3' sequence associated with genomic cytosine methylation, containing 5hmC, 5fC, or 5caC placed site-specifically into the 5'-T(8)X(9)G(10)-3' sequence of the DDD, were compared. The presence of 5caC at the X(9) base increased the stability of the DDD, whereas 5hmC or 5fC did not. Both 5hmC and 5fC increased imino proton exchange rates and calculated rate constants for base pair opening at the neighboring base pair A(5):T(8), whereas 5caC did not. At the oxidized base pair G(4):X(9), 5fC exhibited an increase in the imino proton exchange rate and the calculated kop. In all cases, minimal effects to imino proton exchange rates occurred at the neighboring base pair C(3):G(10). No evidence was observed for imino tautomerization, accompanied by wobble base pairing, for 5hmC, 5fC, or 5caC when positioned at base pair G(4):X(9); each favored Watson-Crick base pairing. However, both 5fC and 5caC exhibited intranucleobase hydrogen bonding between their formyl or carboxyl oxygens, respectively, and the adjacent cytosine N(4) exocyclic amines. The lesion-specific differences observed in the DDD may be implicated in recognition of 5hmC, 5fC, or 5caC in DNA by TDG. However, they do not correlate with differential excision of 5hmC, 5fC, or 5caC by TDG, which may be mediated by differences in transition states of the enzyme-bound complexes.

Differential Stabilities and Sequence-Dependent Base Pair Opening Dynamics of Watson–Crick Base Pairs with 5-Hydroxymethylcytosine, 5-Formylcytosine, or 5-Carboxylcytosine

PubMed Central

2016-01-01

5-Hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC) form during active demethylation of 5-methylcytosine (5mC) and are implicated in epigenetic regulation of the genome. They are differentially processed by thymine DNA glycosylase (TDG), an enzyme involved in active demethylation of 5mC. Three modified Dickerson–Drew dodecamer (DDD) sequences, amenable to crystallographic and spectroscopic analyses and containing the 5′-CG-3′ sequence associated with genomic cytosine methylation, containing 5hmC, 5fC, or 5caC placed site-specifically into the 5′-T8X9G10-3′ sequence of the DDD, were compared. The presence of 5caC at the X9 base increased the stability of the DDD, whereas 5hmC or 5fC did not. Both 5hmC and 5fC increased imino proton exchange rates and calculated rate constants for base pair opening at the neighboring base pair A5:T8, whereas 5caC did not. At the oxidized base pair G4:X9, 5fC exhibited an increase in the imino proton exchange rate and the calculated kop. In all cases, minimal effects to imino proton exchange rates occurred at the neighboring base pair C3:G10. No evidence was observed for imino tautomerization, accompanied by wobble base pairing, for 5hmC, 5fC, or 5caC when positioned at base pair G4:X9; each favored Watson–Crick base pairing. However, both 5fC and 5caC exhibited intranucleobase hydrogen bonding between their formyl or carboxyl oxygens, respectively, and the adjacent cytosine N4 exocyclic amines. The lesion-specific differences observed in the DDD may be implicated in recognition of 5hmC, 5fC, or 5caC in DNA by TDG. However, they do not correlate with differential excision of 5hmC, 5fC, or 5caC by TDG, which may be mediated by differences in transition states of the enzyme-bound complexes. PMID:25632825

Differential stabilities and sequence-dependent base pair opening dynamics of Watson–Crick base pairs with 5-hydroxymethylcytosine, 5-formylcytosine, or 5-carboxylcytosine

DOE PAGES

Szulik, Marta W.; Pallan, Pradeep S.; Nocek, Boguslaw; ...

2015-01-29

5-Hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC) form during active demethylation of 5-methylcytosine (5mC) and are implicated in epigenetic regulation of the genome. They are differentially processed by thymine DNA glycosylase (TDG), an enzyme involved in active demethylation of 5mC. Three modified Dickerson–Drew dodecamer (DDD) sequences, amenable to crystallographic and spectroscopic analyses and containing the 5'-CG-3' sequence associated with genomic cytosine methylation, containing 5hmC, 5fC, or 5caC placed site-specifically into the 5'-T 8X 9G 10-3' sequence of the DDD, were compared. The presence of 5caC at the X9 base increased the stability of the DDD, whereas 5hmC or 5fC didmore » not. Both 5hmC and 5fC increased imino proton exchange rates and calculated rate constants for base pair opening at the neighboring base pair A 5:T 8, whereas 5caC did not. At the oxidized base pair G 4:X 9, 5fC exhibited an increase in the imino proton exchange rate and the calculated k op. In all cases, minimal effects to imino proton exchange rates occurred at the neighboring base pair C 3:G 10. No evidence was observed for imino tautomerization, accompanied by wobble base pairing, for 5hmC, 5fC, or 5caC when positioned at base pair G 4:X 9; each favored Watson–Crick base pairing. However, both 5fC and 5caC exhibited intranucleobase hydrogen bonding between their formyl or carboxyl oxygens, respectively, and the adjacent cytosine N 4 exocyclic amines. The lesion-specific differences observed in the DDD may be implicated in recognition of 5hmC, 5fC, or 5caC in DNA by TDG. Furthermore, they do not correlate with differential excision of 5hmC, 5fC, or 5caC by TDG, which may be mediated by differences in transition states of the enzyme-bound complexes.« less

12 CFR 327.5 - Assessment base.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Assessment base. 327.5 Section 327.5 Banks and... General § 327.5 Assessment base. (a) Assessment base for all insured depository institutions. Except as provided in paragraphs (b), (c), and (d) of this section, the assessment base for an insured depository...

12 CFR 327.5 - Assessment base.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Assessment base. 327.5 Section 327.5 Banks and... General § 327.5 Assessment base. (a) Assessment base for all insured depository institutions. Except as provided in paragraphs (b), (c), and (d) of this section, the assessment base for an insured depository...

The CAS-NAS forum for new leaders in space science

NASA Astrophysics Data System (ADS)

Smith, David H.

The space science community is thoroughly international, with numerous nations now capable of launching scientific payloads into space either independently or in concert with others. As such, it is important for national space-science advisory groups to engage with like-minded groups in other spacefaring nations. The Space Studies Board of the US National Academy of Sciences' (NAS') National Research Council has provided scientific and technical advice to NASA for more than 50 years. Over this period, the Board has developed important multilateral and bilateral partnerships with space scientists around the world. The primary multilateral partner is COSPAR, for which the Board serves as the US national committee. The Board's primary bilateral relationship is with the European Science Foundation’s European Space Science Committee. Burgeoning Chinese space activities have resulted in several attempts in the past decade to open a dialogue between the Board and space scientists in China. On each occasion, the external political environment was not conducive to success. The most recent efforts to engage the Chinese space researchers began in 2011 and have proved particularly successful. Although NASA is currently prohibited from engaging in bilateral activities with China, the Board has established a fruitful dialogue with its counterpart in the Chinese Academy of Sciences (CAS). A joint NAS-CAS activity, the Forum for New Leaders in Space Science, has been established to provide opportunities for a highly select group of young space scientists from China and the United States to discuss their research activities in an intimate and collegial environment at meetings to be held in both nations. The presentation will describe the current state of US-China space relations, discuss the goals of the joint NAS-CAS undertaking and report on the activities at the May, 2014, Forum in Beijing and the planning for the November, 2014, Forum in Irvine, California.

First Detection of a Pulsar Bow Shock Nebula in Far-UV: PSR J0437-4715

NASA Astrophysics Data System (ADS)

Rangelov, Blagoy; Pavlov, George G.; Kargaltsev, Oleg; Durant, Martin; Bykov, Andrei M.; Krassilchtchikov, Alexandre

2016-11-01

Pulsars traveling at supersonic speeds are often accompanied by cometary bow shocks seen in Hα. We report on the first detection of a pulsar bow shock in the far-ultraviolet (FUV). We detected it in FUV images of the nearest millisecond pulsar J0437-4715 obtained with the Hubble Space Telescope. The images reveal a bow-like structure positionally coincident with part of the previously detected Hα bow shock, with an apex at 10″ ahead of the moving pulsar. Its FUV luminosity, L(1250{--}2000 \\mathringA )≈ 5 × {10}28 erg s-1, exceeds the Hα luminosity from the same area by a factor of 10. The FUV emission could be produced by the shocked interstellar medium matter or, less likely, by relativistic pulsar wind electrons confined by strong magnetic field fluctuations in the bow shock. In addition, in the FUV images we found a puzzling extended (≃3″ in size) structure overlapping with the limb of the bow shock. If related to the bow shock, it could be produced by an inhomogeneity in the ambient medium or an instability in the bow shock. We also report on a previously undetected X-ray emission extending for about 5″ ahead of the pulsar, possibly a pulsar wind nebula created by shocked pulsar wind, with a luminosity L(0.5-8 keV) ˜ 3 × 1028 erg s-1. Based on observations made 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 NAS 5-26555. These observations are associated with programs GO 12917 and GO 10568.

Theoretical studies of optical gain tuning by hydrostatic pressure in GaInNAs/GaAs quantum wells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gladysiewicz, M.; Wartak, M. S.; Department of Physics and Computer Science, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5

In order to describe theoretically the tuning of the optical gain by hydrostatic pressure in GaInNAs/GaAs quantum wells (QWs), the optical gain calculations within kp approach were developed and applied for N-containing and N-free QWs. The electronic band structure and the optical gain for GaInNAs/GaAs QW were calculated within the 10-band kp model which takes into account the interaction of electron levels in the QW with the nitrogen resonant level in GaInNAs. It has been shown that this interaction increases with the hydrostatic pressure and as a result the optical gain for GaInNAs/GaAs QW decreases by about 40% and 80%more » for transverse electric and transverse magnetic modes, respectively, for the hydrostatic pressure change from 0 to 40 kilobars. Such an effect is not observed for N-free QWs where the dispersion of electron and hole energies remains unchanged with the hydrostatic pressure. This is due to the fact that the conduction and valence band potentials in GaInAs/GaAs QW scale linearly with the hydrostatic pressure.« less

NAS Requirements Checklist for Job Queuing/Scheduling Software

NASA Technical Reports Server (NTRS)

Jones, James Patton

1996-01-01

The increasing reliability of parallel systems and clusters of computers has resulted in these systems becoming more attractive for true production workloads. Today, the primary obstacle to production use of clusters of computers is the lack of a functional and robust Job Management System for parallel applications. This document provides a checklist of NAS requirements for job queuing and scheduling in order to make most efficient use of parallel systems and clusters for parallel applications. Future requirements are also identified to assist software vendors with design planning.

The Chemical Evolution of Phosphorus

NASA Astrophysics Data System (ADS)

Jacobson, Heather R.; Thanathibodee, Thanawuth; Frebel, Anna; Roederer, Ian U.; Cescutti, Gabriele; Matteucci, Francesca

2014-12-01

Phosphorus is one of the few remaining light elements for which little is known about its nucleosynthetic origin and chemical evolution, given the lack of optical absorption lines in the spectra of long-lived FGK-type stars. We have identified a P I doublet in the near-ultraviolet (2135/2136 Å) that is measurable in stars of low metallicity. Using archival Hubble Space Telescope-Space Telescope Imaging Spectrograph spectra, we have measured P abundances in 13 stars spanning -3.3 <= [Fe/H] <= -0.2, and obtained an upper limit for a star with [Fe/H] ~ -3.8. Combined with the only other sample of P abundances in solar-type stars in the literature, which spans a range of -1 <= [Fe/H] <= +0.2, we compare the stellar data to chemical evolution models. Our results support previous indications that massive-star P yields may need to be increased by a factor of a few to match stellar data at all metallicities. Our results also show that hypernovae were important contributors to the P production in the early universe. As P is one of the key building blocks of life, we also discuss the chemical evolution of the important elements to life, C-N-O-P-S, together. Based on observations made 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 NAS 5-26555. This work is supported through program AR-13246. Other portions of this work are based on data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile, and the McDonald Observatory of the University of Texas at Austin.

Leo P: How Many Metals Can a Very Low Mass, Isolated Galaxy Retain?

NASA Astrophysics Data System (ADS)

McQuinn, Kristen B. W.; Skillman, Evan D.; Dolphin, Andrew; Cannon, John M.; Salzer, John J.; Rhode, Katherine L.; Adams, Elizabeth A. K.; Berg, Danielle; Giovanelli, Riccardo; Haynes, Martha P.

2015-12-01

Leo P is a gas-rich dwarf galaxy with an extremely low gas-phase oxygen abundance (3% solar). The isolated nature of Leo P enables a quantitative measurement of metals lost solely due to star formation feedback. We present an inventory of the oxygen atoms in Leo P based on the gas-phase oxygen abundance measurement, the star formation history (SFH), and the chemical enrichment evolution derived from resolved stellar populations. The SFH also provides the total amount of oxygen produced. Overall, Leo P has retained 5% of its oxygen; 25% of the retained oxygen is in the stars while 75% is in the gas phase. This is considerably lower than the 20%-25% calculated for massive galaxies, supporting the trend for less efficient metal retention for lower-mass galaxies. The retention fraction is higher than that calculated for other alpha elements (Mg, Si, Ca) in dSph Milky Way satellites of similar stellar mass and metallicity. Accounting only for the oxygen retained in stars, our results are consistent with those derived for the alpha elements in dSph galaxies. Thus, under the assumption that the dSph galaxies lost the bulk of their gas mass through an environmental process such as tidal stripping, the estimates of retained metal fractions represent underestimates by roughly a factor of four. Because of its isolation, Leo P provides an important datum for the fraction of metals lost as a function of galaxy mass due to star formation. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

Massive Star Clusters in Ongoing Galaxy Interactions: Clues to Cluster Formation

NASA Astrophysics Data System (ADS)

Keel, William C.; Borne, Kirk D.

2003-09-01

We present HST WFPC2 observations, supplemented by ground-based Hα data, of the star-cluster populations in two pairs of interacting galaxies selected for being in very different kinds of encounters seen at different stages. Dynamical information and n-body simulations provide the details of encounter geometry, mass ratio, and timing. In NGC 5752/4 we are seeing a weak encounter, well past closest approach, after about 2.5×108 yr. The large spiral NGC 5754 has a normal population of disk clusters, while the fainter companion NGC 5752 exhibits a rich population of luminous clusters with a flatter luminosity function. The strong, ongoing encounter in NGC 6621/2, seen about 1.0×108 yr past closest approach between roughly equal-mass galaxies, has produced an extensive population of luminous clusters, particularly young and luminous in a small region between the two nuclei. This region is dynamically interesting, with such a strong perturbation in the velocity field that the rotation curve reverses sign. From these results, in comparison with other strongly interacting systems discussed in the literature, cluster formation requires a threshold level of perturbation, with stage of the interaction a less important factor. The location of the most active star formation in NGC 6621/2 draws attention to a possible role for the Toomre stability threshold in shaping star formation in interacting galaxies. The rich cluster populations in NGC 5752 and NGC 6621 show that direct contact between gas-rich galaxy disks is not a requirement to form luminous clusters and that they can be triggered by processes happening within a single galaxy disk (albeit triggered by external perturbations). 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 NAS 5-26555.

Optical Properties of A GaInNAs Multi-Quantum Well Semiconductor

NASA Astrophysics Data System (ADS)

Hughes, Timothy S.; Ren, Shang-Fen; Jiang, De-Sheng; Xiaogan, Liang

2002-03-01

Optoelectronic devices used today depend on lasers that have wavelengths in the optical fiber transmission window of 1.3 to 1.55 micrometers. When using GaAs substrate semiconductor lasers, we typically see this range of light emission. Quaternary materials, such as GaInNAs grown on this substrate, not only allow us to control the output wavelength, but it also allows us to manipulate the lattice constant. Further research has potential to produce low-costing highly efficient Vertical Cavity Surface Emitting Lasers (VCSEL). Using a Fourier-Transform Spectrometer, a method of using a Michelson Interferometer to measure the interference between two coherent beams, we measured and analyzed the photoluminescence spectra of a GaInNAs multi-quantum well semiconductor, grown using the Molecular Beam Epitaxy (MBE) growth technique. The experiments of this research were carried out in an undergraduate international research experience at the Chinese Semiconductor Institute supported by the Division of International Programs of NSF.

Exposure to prescription opioid analgesics in utero and risk of neonatal abstinence syndrome: population based cohort study.

PubMed

Desai, Rishi J; Huybrechts, Krista F; Hernandez-Diaz, Sonia; Mogun, Helen; Patorno, Elisabetta; Kaltenbach, Karol; Kerzner, Leslie S; Bateman, Brian T

2015-05-14

To provide absolute and relative risk estimates of neonatal abstinence syndrome (NAS) based on duration and timing of prescription opioid use during pregnancy in the presence or absence of additional NAS risk factors of history of opioid misuse or dependence, misuse of other substances, non-opioid psychotropic drug use, and smoking. Observational cohort study. Medicaid data from 46 US states. Pregnant women filling at least one prescription for an opioid analgesic at any time during pregnancy for whom opioid exposure characteristics including duration of therapy: short term (<30 days) or long term (≥ 30 days); timing of use: early use (only in the first two trimesters) or late use (extending into the third trimester); and cumulative dose (in morphine equivalent milligrams) were assessed. Diagnosis of NAS in liveborn infants. 1705 cases of NAS were identified among 290,605 pregnant women filling opioid prescriptions, corresponding to an absolute risk of 5.9 per 1000 deliveries (95% confidence interval 5.6 to 6.2). Long term opioid use during pregnancy resulted in higher absolute risk of NAS per 1000 deliveries in the presence of additional risk factors of known opioid misuse (220.2 (200.8 to 241.0)), alcohol or other drug misuse (30.8 (26.1 to 36.0)), exposure to other psychotropic medications (13.1 (10.6 to 16.1)), and smoking (6.6 (4.3 to 9.6)) than in the absence of any of these risk factors (4.2 (3.3 to 5.4)). The corresponding risk estimates for short term use were 192.0 (175.8 to 209.3), 7.0 (6.0 to 8.2), 2.0 (1.5 to 2.6), 1.5 (1.0 to 2.0), and 0.7 (0.6 to 0.8) per 1000 deliveries, respectively. In propensity score matched analyses, long term prescription opioid use compared with short term use and late use compared with early use in pregnancy demonstrated greater risk of NAS (risk ratios 2.05 (95% confidence interval 1.81 to 2.33) and 1.24 (1.12 to 1.38), respectively). Use of prescription opioids during pregnancy is associated with a low absolute risk of

Concepts of Integration for UAS Operations in the NAS

NASA Technical Reports Server (NTRS)

Consiglio, Maria C.; Chamberlain, James P.; Munoz, Cesar A.; Hoffler, Keith D.

2012-01-01

One of the major challenges facing the integration of Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is the lack of an onboard pilot that can comply with the legal requirement identified in the US Code of Federal Regulations (CFR) that pilots see and avoid other aircraft. UAS will be expected to demonstrate the means to perform the function of see and avoid while preserving the safety level of the airspace and the efficiency of the air traffic system. This paper introduces a Sense and Avoid (SAA) concept for integration of UAS into the NAS that is currently being developed by the National Aeronautics and Space Administration (NASA) and identifies areas that require additional experimental evaluation to further inform various elements of the concept. The concept design rests on interoperability principles that take into account both the Air Traffic Control (ATC) environment as well as existing systems such as the Traffic Alert and Collision Avoidance System (TCAS). Specifically, the concept addresses the determination of well clear values that are large enough to avoid issuance of TCAS corrective Resolution Advisories, undue concern by pilots of proximate aircraft and issuance of controller traffic alerts. The concept also addresses appropriate declaration times for projected losses of well clear conditions and maneuvers to regain well clear separation.

GaInNAs Structures Grown by MBE for High-Efficiency Solar Cells: Final Report; 25 June 1999--24 August 2002

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tu, C. W.

The focus of this work is to improve the quality of GaInNAs by advanced thin-film growth techniques, such as digital-alloy growth techniques and migration-enhanced epitaxy (MEE). The other focus is to further investigate the properties of such materials, which are potentially beneficial for high-efficiency, multijunction solar cells. 400-nm-thick strain-compensated Ga0.92In0.08As/GaN0.03As0.97 short-period superlattices (SPSLs) are grown lattice-matched to GaAs substrates. The photoluminescence (PL) intensity of digital alloys is 3 times higher than that of random alloys at room temperature, and the improvement is even greater at low temperature, by a factor of about 12. The room-temperature PL intensity of the GaInNAsmore » quantum well grown by the strained InAs/GaN0.023As SPSL growth mode is higher by a factor 5 as compare to the continuous growth mode. The SPSL growth method allows for independent adjustment of the In-to-Ga ratio without group III competition. MEE reduces the low-energy tail of PL, and PL peaks become more intense and sharper. The twin peaks photoluminescence of GaNAs grown on GaAs was observed at room temperature. The peaks splitting increase with increase in nitrogen alloy content. The strain-induced splitting of light-hole and heavy-hole bands of tensile-strained GaNAs is proposed as an explanation of such behavior.« less

NAS (Host/ARTS) IIIA to VME Modem Interface ATC Interface Hardware Manual

DOT National Transportation Integrated Search

1990-10-01

This document is reference material for personnel using the National Airspace : System (NAS) (HOST or ARTS IIIA) Air Traffic Control (ATC) Interface Subsystem. : It was originally developed to be part of the Data Link Test and Analysis System : (DATA...

The temperature dependence of atomic incorporation characteristics in growing GaInNAs films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Jingling; Gao, Fangliang; Wen, Lei

We have systematically studied the temperature dependence of incorporation characteristics of nitrogen (N) and indium (In) in growing GaInNAs films. With the implementation of Monte-Carlo simulation, the low N adsorption energy (−0.10 eV) is demonstrated. To understand the atomic incorporation mechanism, temperature dependence of interactions between Group-III and V elements are subsequently discussed. We find that the In incorporation behaviors rather than that of N are more sensitive to the T{sub g}, which can be experimentally verified by exploring the compositional modulation and structural changes of the GaInNAs films by means of high-resolution X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope,more » and secondary ion mass spectroscopy.« less

The Great Observatories Origins Deep Survey (GOODS): Overview and Status

NASA Astrophysics Data System (ADS)

Hook, R. N.; GOODS Team

2002-12-01

GOODS is a very large project to gather deep imaging data and spectroscopic followup of two fields, the Hubble Deep Field North (HDF-N) and the Chandra Deep Field South (CDF-S), with both space and ground-based instruments to create an extensive multiwavelength public data set for community research on the distant Universe. GOODS includes a SIRTF Legacy Program (PI: Mark Dickinson) and a Hubble Treasury Program of ACS imaging (PI: Mauro Giavalisco). The ACS imaging was also optimized for the detection of high-z supernovae which are being followed up by a further target of opportunity Hubble GO Program (PI: Adam Riess). The bulk of the CDF-S ground-based data presently available comes from an ESO Large Programme (PI: Catherine Cesarsky) which includes both deep imaging and multi-object followup spectroscopy. This is currently complemented in the South by additional CTIO imaging. Currently available HDF-N ground-based data forming part of GOODS includes NOAO imaging. Although the SIRTF part of the survey will not begin until later in the year the ACS imaging is well advanced and there is also a huge body of complementary ground-based imaging and some follow-up spectroscopy which is already publicly available. We summarize the current status of GOODS and give an overview of the data products currently available and present the timescales for the future. Many early science results from the survey are presented in other GOODS papers at this meeting. Support for the HST GOODS program presented here and in companion abstracts was provided by NASA thorugh grant number GO-9425 from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555.

Shadow Mode Assessment Using Realistic Technologies for the National Airspace (SMART NAS)

NASA Technical Reports Server (NTRS)

Kopardekar, Parimal H.

2014-01-01

Develop a simulation and modeling capability that includes: (a) Assessment of multiple parallel universes, (b) Accepts data feeds, (c) Allows for live virtual constructive distribute environment, (d) Enables integrated examinations of concepts, algorithms, technologies and National Airspace System (NAS) architectures.

Performance Analysis of the NAS Y-MP Workload

NASA Technical Reports Server (NTRS)

Bergeron, Robert J.; Kutler, Paul (Technical Monitor)

1997-01-01

This paper describes the performance characteristics of the computational workloads on the NAS Cray Y-MP machines, a Y-MP 832 and later a Y-MP 8128. Hardware measurements indicated that the Y-MP workload performance matured over time, ultimately sustaining an average throughput of 0.8 GFLOPS and a vector operation fraction of 87%. The measurements also revealed an operation rate exceeding 1 per clock period, a well-balanced architecture featuring a strong utilization of vector functional units, and an efficient memory organization. Introduction of the larger memory 8128 increased throughput by allowing a more efficient utilization of CPUs. Throughput also depended on the metering of the batch queues; low-idle Saturday workloads required a buffer of small jobs to prevent memory starvation of the CPU. UNICOS required about 7% of total CPU time to service the 832 workloads; this overhead decreased to 5% for the 8128 workloads. While most of the system time went to service I/O requests, efficient scheduling prevented excessive idle due to I/O wait. System measurements disclosed no obvious bottlenecks in the response of the machine and UNICOS to the workloads. In most cases, Cray-provided software tools were- quite sufficient for measuring the performance of both the machine and operating, system.

Strain relaxation induced surface morphology of heterogeneous GaInNAs layers grown on GaAs substrate

NASA Astrophysics Data System (ADS)

Gelczuk, Ł.; Jóźwiak, G.; Moczała, M.; Dłużewski, P.; Dąbrowska-Szata, M.; Gotszalk, T. P.

2017-07-01

The partially-relaxed heterogeneous GaInNAs layers grown on GaAs substrate by atmospheric pressure vapor phase epitaxy (AP-MOVPE) were investigated by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The planar-view TEM image shows a regular 2D network of misfit dislocations oriented in two orthogonal 〈1 1 0〉 crystallographic directions at the (0 0 1) layer interface. Moreover, the cross-sectional view TEM image reveals InAs-rich and V-shaped precipitates in the near surface region of the GaInNAs epitaxial layer. The resultant undulating surface morphology, known as a cross-hatch pattern, is formed as observed by AFM. The numerical analysis of the AFM image of the GaInNAs layer surface with the well-defined cross-hatch morphology enabled us to determine a lower bound of actual density of misfit dislocations. However, a close correspondence between the asymmetric distribution of interfacial misfit dislocations and undulating surface morphology is observed.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project - Systems Integration and Operationalization (SIO) Demonstration

NASA Technical Reports Server (NTRS)

Swieringa, Kurt

2018-01-01

The UAS-NAS Project hosted a Systems Integration Operationalization (SIO) Industry Day for the SIO Request for Information (RFI) on November 30, 2017 in San Diego, California. This presentation is being presented to the same group as a follow up regarding the progress that the UAS-NAS project has made on the SIO RFI. The presentation will be virtual with a teleconference

Hubble Space Telescope Snapshot Survey for Resolved Companions of Galactic Cepheids

NASA Astrophysics Data System (ADS)

Evans, Nancy Remage; Bond, Howard E.; Schaefer, Gail H.; Mason, Brian D.; Tingle, Evan; Karovska, Margarita; Pillitteri, Ignazio

2016-05-01

We have conducted an imaging survey with the Hubble Space Telescope Wide Field Camera 3 (WFC3) of 70 Galactic Cepheids, typically within 1 kpc, with the aim of finding resolved physical companions. The WFC3 field typically covers the 0.1 pc area where companions are expected. In this paper, we identify 39 Cepheids having candidate companions, based on their positions in color-magnitude diagrams, and having separations ⩾ 5'' from the Cepheids. We use follow-up observations of 14 of these candidates with XMM-Newton, and of one of them with ROSAT, to separate X-ray-active young stars (probable physical companions) from field stars (chance alignments). Our preliminary estimate, based on the optical and X-ray observations, is that only 3% of the Cepheids in the sample have wide companions. Our survey easily detects resolved main-sequence companions as faint as spectral type K. Thus the fact that the two most probable companions (those of FF Aql and RV Sco) are earlier than type K is not simply a function of the detection limit. We find no physical companions having separations larger than 4000 au in the X-ray survey. Two Cepheids are exceptions in that they do have young companions at significantly larger separations (δ Cep and S Nor), but both belong to a cluster or a loose association, so our working model is that they are not gravitationally bound binary members, but rather cluster/association members. All of these properties provide constraints on both star formation and subsequent dynamical evolution. The low frequency of true physical companions at separations > 5'' is confirmed by examination of the subset of the nearest Cepheids and also the density of the fields. 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.

The Intrinsically X-Ray-weak Quasar PHL 1811. II. Optical and UV Spectra and Analysis

NASA Astrophysics Data System (ADS)

Leighly, Karen M.; Halpern, Jules P.; Jenkins, Edward B.; Casebeer, Darrin

2007-11-01

This is the second of two papers reporting observations and analysis of the unusually bright (mb=14.4), luminous (MB=-25.5), nearby (z=0.192) narrow-line quasar PHL 1811. The first paper reported that PHL 1811 is intrinsically X-ray-weak and presented a spectral energy distribution (SED). Here we present HST STIS optical and UV spectra, and ground-based optical spectra. The optical and UV line emission is very unusual. There is no evidence for forbidden or semiforbidden lines. The near-UV spectrum is dominated by very strong Fe II and Fe III, and unusual low-ionization lines such as Na I D and Ca II H and K are observed. High-ionization lines are very weak; C IV has an equivalent width of 6.6 Å, a factor of ~5 smaller than measured from quasar composite spectra. An unusual feature near 1200 Å can be deblended in terms of Lyα, N V, Si II, and C III* using the blueshifted C IV profile as a template. Photoionization modeling shows that the unusual line emission can be explained qualitatively by the unusually soft SED. Principally, a low gas temperature results in inefficient emission of collisionally excited lines, including the semiforbidden lines generally used as density diagnostics. The emission resembles that of high-density gas; in both cases this is a consequence of inefficient cooling. PHL 1811 is very unusual, but we note that quasar surveys may be biased against finding similar objects. Based on observations made 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. These observations are associated with proposal 9181. Based on observations obtained at Kitt Peak National Observatory, a division of the National Optical Astronomy Observatories, which is operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation.

Proper Motions of Dwarf Spheroidal Galaxies from Hubble Space Telescope Imaging. IV. Measurement for Sculptor

NASA Astrophysics Data System (ADS)

Piatek, Slawomir; Pryor, Carlton; Bristow, Paul; Olszewski, Edward W.; Harris, Hugh C.; Mateo, Mario; Minniti, Dante; Tinney, Christopher G.

2006-03-01

This article presents a measurement of the proper motion of the Sculptor dwarf spheroidal galaxy determined from images taken with the Hubble Space Telescope using the Space Telescope Imaging Spectrograph in the imaging mode. Each of two distinct fields contains a quasi-stellar object that serves as the ``reference point.'' The measured proper motion of Sculptor, expressed in the equatorial coordinate system, is (μα, μδ)=(9+/-13, 2+/-13) mas century-1. Removing the contributions from the motion of the Sun and the motion of the local standard of rest produces the proper motion in the Galactic rest frame: (μGrfα, μGrfδ)=(-23+/-13, 45+/-13) mas century-1. The implied space velocity with respect to the Galactic center has a radial component of Vr=79+/-6 km s-1 and a tangential component of Vt=198+/-50 km s-1. Integrating the motion of Sculptor in a realistic potential for the Milky Way produces orbital elements. The perigalacticon and apogalacticon are 68 (31, 83) and 122 (97, 313) kpc, respectively, where the values in the parentheses represent the 95% confidence interval derived from Monte Carlo experiments. The eccentricity of the orbit is 0.29 (0.26, 0.60), and the orbital period is 2.2 (1.5, 4.9) Gyr. Sculptor is on a polar orbit around the Milky Way: the angle of inclination is 86° (83°, 90°). 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.

The Resolved Stellar Populations in the LEGUS Galaxies1

NASA Astrophysics Data System (ADS)

Sabbi, E.; Calzetti, D.; Ubeda, L.; Adamo, A.; Cignoni, M.; Thilker, D.; Aloisi, A.; Elmegreen, B. G.; Elmegreen, D. M.; Gouliermis, D. A.; Grebel, E. K.; Messa, M.; Smith, L. J.; Tosi, M.; Dolphin, A.; Andrews, J. E.; Ashworth, G.; Bright, S. N.; Brown, T. M.; Chandar, R.; Christian, C.; Clayton, G. C.; Cook, D. O.; Dale, D. A.; de Mink, S. E.; Dobbs, C.; Evans, A. S.; Fumagalli, M.; Gallagher, J. S., III; Grasha, K.; Herrero, A.; Hunter, D. A.; Johnson, K. E.; Kahre, L.; Kennicutt, R. C.; Kim, H.; Krumholz, M. R.; Lee, J. C.; Lennon, D.; Martin, C.; Nair, P.; Nota, A.; Östlin, G.; Pellerin, A.; Prieto, J.; Regan, M. W.; Ryon, J. E.; Sacchi, E.; Schaerer, D.; Schiminovich, D.; Shabani, F.; Van Dyk, S. D.; Walterbos, R.; Whitmore, B. C.; Wofford, A.

2018-03-01

The Legacy ExtraGalactic UV Survey (LEGUS) is a multiwavelength Cycle 21 Treasury program on the Hubble Space Telescope. It studied 50 nearby star-forming galaxies in 5 bands from the near-UV to the I-band, combining new Wide Field Camera 3 observations with archival Advanced Camera for Surveys data. LEGUS was designed to investigate how star formation occurs and develops on both small and large scales, and how it relates to the galactic environments. In this paper we present the photometric catalogs for all the apparently single stars identified in the 50 LEGUS galaxies. Photometric catalogs and mosaicked images for all filters are available for download. We present optical and near-UV color–magnitude diagrams for all the galaxies. For each galaxy we derived the distance from the tip of the red giant branch. We then used the NUV color–magnitude diagrams to identify stars more massive than 14 M ⊙, and compared their number with the number of massive stars expected from the GALEX FUV luminosity. Our analysis shows that the fraction of massive stars forming in star clusters and stellar associations is about constant with the star formation rate. This lack of a relation suggests that the timescale for evaporation of unbound structures is comparable or longer than 10 Myr. At low star formation rates this translates to an excess of mass in clustered environments as compared to model predictions of cluster evolution, suggesting that a significant fraction of stars form in unbound systems. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA Inc., under NASA contract NAS 5-26555.

Star Formation at z = 2.481 in the Lensed Galaxy SDSS J1110 = 6459. I. Lens Modeling and Source Reconstruction

NASA Astrophysics Data System (ADS)

Johnson, Traci L.; Sharon, Keren; Gladders, Michael D.; Rigby, Jane R.; Bayliss, Matthew B.; Wuyts, Eva; Whitaker, Katherine E.; Florian, Michael; Murray, Katherine T.

2017-07-01

Using the combined resolving power of the Hubble Space Telescope and gravitational lensing, we resolve star-forming structures in a z˜ 2.5 galaxy on scales much smaller than the usual kiloparsec diffraction limit of HST. SGAS J111020.0+645950.8 is a clumpy, star-forming galaxy lensed by the galaxy cluster SDSS J1110+6459 at z=0.659, with a total magnification ˜ 30× across the entire arc. We use a hybrid parametric/non-parametric strong lensing mass model to compute the deflection and magnification of this giant arc, reconstruct the light distribution of the lensed galaxy in the source plane, and resolve the star formation into two dozen clumps. We develop a forward-modeling technique to model each clump in the source plane. We ray-trace the model to the image plane, convolve with the instrumental point-spread function (PSF), and compare with the GALFIT model of the clumps in the image plane, which decomposes clump structure from more extended emission. This technique has the advantage, over ray-tracing, of accounting for the asymmetric lensing shear of the galaxy in the image plane and the instrument PSF. At this resolution, we can begin to study star formation on a clump-by-clump basis, toward the goal of understanding feedback mechanisms and the buildup of exponential disks at high redshift. Based on observations made 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 NAS 5-26555. These observations are associated with program # 13003.

12 CFR 327.5 - Assessment base.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 4 2011-01-01 2011-01-01 false Assessment base. 327.5 Section 327.5 Banks and... General § 327.5 Assessment base. (a) Quarter-end balances and average daily balances. An insured depository institution shall determine its assessment base using quarter-end balances until changes in the...

UAS Integration in the NAS Project: Integrated Test and LVC Infrastructure

NASA Technical Reports Server (NTRS)

Murphy, Jim; Hoang, Ty

2015-01-01

Overview presentation of the Integrated Test and Evaluation sub-project of the Unmanned Aircraft System (UAS) in the National Airspace System (NAS). The emphasis of the presentation is the Live, Virtual, and Constructive (LVC) system (a broadly used name for classifying modeling and simulation) infrastructure and use of external assets and connection.

Integrating Astronomy with Elementary Non-Science Curricula

NASA Astrophysics Data System (ADS)

Bobrowsky, M.

1996-05-01

A workshop was developed for elementary school teachers to enhance students' understanding of astronomy during the formative years of elementary school by incorporating astronomy into various non-science curricula. Educational material was compiled for teachers and students and training was provided for the teachers in the form of a workshop where both information and hands-on activities were disseminated. In addition, we are producing a video tape from the workshop which will be available not only to those who attended the workshop but to other teachers as well. A useful ``multiplier effect" in this project came from our focus on a school that was hosting a group of teachers in training. After these teachers receive certification, they will end up working in all different schools, thereby reaching large numbers of students for many years. The non-scientific subjects that we will connect to astronomy include history, music, art, language arts, social studies, and mathematics, as well as incidental subjects such as health and public safety. Support for this work was provided by NASA through grant number ED90024.01-94A from the Space Telescope Science Institute which is operated by the Association of Universities for Research in Astronomy Inc. under NASA Contract NAS5-26555.

Temporal Variations in Jupiter's Atmosphere

NASA Technical Reports Server (NTRS)

Simon-Miller, Amy A.; Chanover, N. J.; Yanamandra-Fisher, P.; Hammel, H. B.; dePater, I.; Noll, K.; Wong, M.; Clarke, J.; Sanchez-Levega, A.; Orton, G. S.;

UAS Integration in the NAS Project: Flight Test 3 Data Analysis of JADEM-Autoresolver Detect and Avoid System

NASA Technical Reports Server (NTRS)

Gong, Chester; Wu, Minghong G.; Santiago, Confesor

2016-01-01

The Unmanned Aircraft Systems Integration in the National Airspace System project, or UAS Integration in the NAS, aims to reduce technical barriers related to safety and operational challenges associated with enabling routine UAS access to the NAS. The UAS Integration in the NAS Project conducted a flight test activity, referred to as Flight Test 3 (FT3), involving several Detect-and-Avoid (DAA) research prototype systems between June 15, 2015 and August 12, 2015 at the Armstrong Flight Research Center (AFRC). This report documents the flight testing and analysis results for the NASA Ames-developed JADEM-Autoresolver DAA system, referred to as 'Autoresolver' herein. Four flight test days (June 17, 18, 22, and July 22) were dedicated to Autoresolver testing. The objectives of this test were as follows: 1. Validate CPA prediction accuracy and detect-and-avoid (DAA, formerly known as self-separation) alerting logic in realistic flight conditions. 2. Validate DAA trajectory model including maneuvers. 3. Evaluate TCAS/DAA interoperability. 4. Inform final Minimum Operating Performance Standards (MOPS). Flight test scenarios were designed to collect data to directly address the objectives 1-3. Objective 4, inform final MOPS, was a general objective applicable to the UAS in the NAS project as a whole, of which flight test is a subset. This report presents analysis results completed in support of the UAS in the NAS project FT3 data review conducted on October 20, 2015. Due to time constraints and, to a lesser extent, TCAS data collection issues, objective 3 was not evaluated in this analysis.

Star Formation Histories of the LEGUS Dwarf Galaxies. II. Spatially Resolved Star Formation History of the Magellanic Irregular NGC 4449

NASA Astrophysics Data System (ADS)

Sacchi, E.; Cignoni, M.; Aloisi, A.; Tosi, M.; Calzetti, D.; Lee, J. C.; Adamo, A.; Annibali, F.; Dale, D. A.; Elmegreen, B. G.; Gouliermis, D. A.; Grasha, K.; Grebel, E. K.; Hunter, D. A.; Sabbi, E.; Smith, L. J.; Thilker, D. A.; Ubeda, L.; Whitmore, B. C.

2018-04-01

We present a detailed study of the Magellanic irregular galaxy NGC 4449 based on both archival and new photometric data from the Legacy Extragalactic UV Survey, obtained with the Hubble Space Telescope Advanced Camera for Surveys and Wide Field Camera 3. Thanks to its proximity (D = 3.82 ± 0.27 Mpc), we reach stars 3 mag fainter than the tip of the red giant branch in the F814W filter. The recovered star formation history (SFH) spans the whole Hubble time, but due to the age–metallicity degeneracy of the red giant branch stars, it is robust only over the lookback time reached by our photometry, i.e., ∼3 Gyr. The most recent peak of star formation (SF) is around 10 Myr ago. The average surface density SF rate over the whole galaxy lifetime is 0.01 M ⊙ yr‑1 kpc‑2. From our study, it emerges that NGC 4449 has experienced a fairly continuous SF regime in the last 1 Gyr, with peaks and dips whose SF rates differ only by a factor of a few. The very complex and disturbed morphology of NGC 4449 makes it an interesting galaxy for studies of the relationship between interactions and starbursts, and our detailed and spatially resolved analysis of its SFH does indeed provide some hints on the connection between these two phenomena in this peculiar dwarf galaxy. Based on observations obtained with the NASA/ESA Hubble Space Telescope at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy under NASA contract NAS 5-26555.

Interstellar Gas-phase Element Depletions in the Small Magellanic Cloud: A Guide to Correcting for Dust in QSO Absorption Line Systems

NASA Astrophysics Data System (ADS)

Jenkins, Edward B.; Wallerstein, George

2017-04-01

We present data on the gas-phase abundances for 9 different elements in the interstellar medium of the Small Magellanic Cloud (SMC), based on the strengths of ultraviolet absorption features over relevant velocities in the spectra of 18 stars within the SMC. From this information and the total abundances defined by the element fractions in young stars in the SMC, we construct a general interpretation on how these elements condense into solid form onto dust grains. As a group, the elements Si, S, Cr, Fe, Ni, and Zn exhibit depletion sequences similar to those in the local part of our Galaxy defined by Jenkins. The elements Mg and Ti deplete less rapidly in the SMC than in the Milky Way, and Mn depletes more rapidly. We speculate that these differences might be explained by the different chemical affinities to different existing grain substrates. For instance, there is evidence that the mass fractions of polycyclic aromatic hydrocarbons in the SMC are significantly lower than those in the Milky Way. We propose that the depletion sequences that we observed for the SMC may provide a better model for interpreting the element abundances in low-metallicity Damped Lyman Alpha (DLA) and sub-DLA absorption systems that are recorded in the spectra of distant quasars and gamma-ray burst afterglows. Based on observations with the NASA/ESA Hubble Space Telescope and additional data obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Associations of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. These observations are associated with program nr. 13778.

Many-body design of highly strained GaInNAs electroabsorption modulators on GaInAs ternary substrates

NASA Astrophysics Data System (ADS)

Fujisawa, Takeshi; Arai, Masakazu; Kano, Fumiyoshi

2010-05-01

Electroabsorption in highly strained GaInAs and GaInNAs quantum wells (QWs) grown on GaInAs or quasi-GaInAs substrates is investigated by using microscopic many-body theory. The effects of various parameters, such as strain, barrier height, substrate composition, and temperature are thoroughly examined. It is shown that the value of the absorption coefficient strongly depends on the depth of the QWs under large bias electric field due to the small overlap integral of wave functions between the conduction and valence bands. The use of GaInNAs QWs makes the strain in the well layer very small. Further, the effective quantum-well depth is increased in GaInNAs QWs due to the anticrossing interaction between the conduction and N-resonant bands, making it possible to obtain larger absorption coefficient under large bias electric fields without using wide-band gap materials for barriers.

UAS Integration in the NAS Project: Detect and Avoid Display UNITED Demo

NASA Technical Reports Server (NTRS)

Roberts, Zachary

2017-01-01

This demo shows the UAS-NAS project's Vigilant Spirit Control Station developed in partnership with the U.S. Air Force Research Lab. Attendees will be able to view encounters and see how the DAA and TCAS II alerting and guidance displays are used to avoid simulated aircraft.

Performance and Scalability of the NAS Parallel Benchmarks in Java

NASA Technical Reports Server (NTRS)

Frumkin, Michael A.; Schultz, Matthew; Jin, Haoqiang; Yan, Jerry; Biegel, Bryan A. (Technical Monitor)

2002-01-01

Several features make Java an attractive choice for scientific applications. In order to gauge the applicability of Java to Computational Fluid Dynamics (CFD), we have implemented the NAS (NASA Advanced Supercomputing) Parallel Benchmarks in Java. The performance and scalability of the benchmarks point out the areas where improvement in Java compiler technology and in Java thread implementation would position Java closer to Fortran in the competition for scientific applications.

NASA UAS Integration into the NAS Project: Human Systems Integration

NASA Technical Reports Server (NTRS)

Shively, Jay

2016-01-01

This presentation provides an overview of the work the Human Systems Integration (HSI) sub-project has done on detect and avoid (DAA) displays while working on the UAS (Unmanned Aircraft System) Integration into the NAS project. The most recent simulation on DAA interoperability with Traffic Collision Avoidance System (TCAS) is discussed in the most detail. The relationship of the work to the larger UAS community and next steps are also detailed.

The structure and environment of young stellar clusters in spiral galaxies

NASA Astrophysics Data System (ADS)

Larsen, S. S.

2004-03-01

Astronomy, Inc., under NASA contract NAS 5-26555.

GaInNAsSb/GaAs vertical cavity surface-emitting lasers (VCSELs): current challenges and techniques to realize multiple-wavelength laser arrays at 1.55 μm

NASA Astrophysics Data System (ADS)

Gobet, Mathilde; Bae, Hopil P.; Sarmiento, Tomas; Harris, James S.

2008-02-01

Multiple-wavelength laser arrays at 1.55 μm are key components of wavelength division multiplexing (WDM) systems for increased bandwidth. Vertical cavity surface-emitting lasers (VCSELs) grown on GaAs substrates outperform their InP counterparts in several points. We summarize the current challenges to realize continuous-wave (CW) GaInNAsSb VCSELs on GaAs with 1.55 μm emission wavelength and explain the work in progress to realize CW GaInNAsSb VCSELs. Finally, we detail two techniques to realize GaInNAsSb multiple-wavelength VCSEL arrays at 1.55 μm. The first technique involves the incorporation of a photonic crystal into the upper mirror. Simulation results for GaAs-based VCSEL arrays at 1.55 μm are shown. The second technique uses non-uniform molecular beam epitaxy (MBE). We have successfully demonstrated 1x6 resonant cavity light-emitting diode arrays at 850 nm using this technique, with wavelength spacing of 0.4 nm between devices and present these results.

Near-Infrared Imaging Polarimetry of the GG Tauri Circumbinary Ring

NASA Astrophysics Data System (ADS)

Silber, Joel; Gledhill, Tim; Duchêne, Gaspard; Ménard, François

2000-06-01

We present 1 μm Hubble Space Telescope/near-infrared camera and multiobject spectrometer resolved imaging polarimetry of the GG Tau circumbinary ring. We find that the ring displays east-west asymmetries in surface brightness as well as several pronounced irregularities but is smoother than suggested by ground-based adaptive optics observations. The data are consistent with a 37° system inclination and a projected rotational axis at a position angle of 7° east of north, determined from millimeter imaging. The ring is strongly polarized, up to ~50%, which is indicative of Rayleigh-like scattering from submicron dust grains. Although the polarization pattern is broadly centrosymmetric and clearly results from illumination of the ring by the central stars, departures from true centrosymmetry and the irregular flux suggest that binary illumination, scattering through unresolved circumstellar disks, and shading by these disks may all be factors influencing the observed morphology. We confirm a ~0.25" shift between the inner edges of the near-infrared and millimeter images and find that the global morphology of the ring and the polarimetry provide strong evidence for a geometrically thick ring. A simple Monte Carlo scattering simulation is presented that reproduces these features and supports the thick-ring hypothesis. We cannot confirm filamentary streaming from the binary to the ring, also observed in the ground-based images, although it is possible that there is material inside the dynamically cleared region that might contribute to filamentary deconvolution artifacts. Finally, we find a faint fifth point source in the GG Tau field that, if it is associated with the system, is almost certainly a brown dwarf. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project Subcommittee Final

NASA Technical Reports Server (NTRS)

Johnson, Chuck; Griner, James H.; Hayhurst, Kelly J.; Shively, Robert J.; Consiglio, Maria; Muller, Eric; Murphy, James; Kim, Sam

2012-01-01

UAS Integration in the NAS Project overview with details from each of the subprojects. Subprojects include: Communications, Certification, Integrated Test and Evaluation, Human Systems Integration, and Separation Assurance/Sense and Avoid Interoperability.

Oxidized C5-methyl cytosine bases in DNA: 5-Hydroxymethylcytosine; 5-formylcytosine; and 5-carboxycytosine.

PubMed

Klungland, Arne; Robertson, Adam B

2017-06-01

Recent reports suggest that the Tet enzyme family catalytically oxidize 5-methylcytosine in mammalian cells. The oxidation of 5-methylcytosine can result in three chemically distinct species - 5-hydroxymethylcytsine, 5-formylcytosine, and 5-carboxycytosine. While the base excision repair machinery processes 5-formylcytosine and 5-carboxycytosine rapidly, 5-hydroxymethylcytosine is stable under physiological conditions. As a stable modification 5-hydroxymethylcytosine has a broad range of functions, from stem cell pluriopotency to tumorigenesis. The subsequent oxidation products, 5-formylcytosine and 5-carboxycytosine, are suggested to be involved in an active DNA demethylation pathway. This review provides an overview of the biochemistry and biology of 5-methylcytosine oxidation products. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Optimization of nas lemoore scheduling to support a growing aircraft population

DTIC Science & Technology

2017-03-01

requirements, and, without knowing the other squadrons’ flight plans , creates his or her squadron’s flight schedule. Figure 2 illustrates the process each...Lemoore, they do not communicate their flight schedules among themselves; hence, the daily flight plan generated by each squadron is independently...manual process for aircraft flight scheduling at Naval Air Station (NAS) Lemoore accommodates the independent needs of 16 fighter resident squadrons as

Characterization of pseudoparticles paired with hemagglutinin and neuraminidase from highly pathogenic H5N1 influenza and avian influenza A (H7N9) viruses.

PubMed

Zhang, Fengwei; Wang, Shanshan; Wang, Yanan; Shang, Xuechai; Zhou, Hongjuan; Cai, Long

2018-05-31

The reassortment of two highly pathogenic avian influenza (HPAI) H5N1 and H7N9 viruses presents a potential challenge to human health. The hemagglutinins (HAs) and neuraminidases (NAs) of these simultaneously circulating avian influenza viruses were evaluated using the pseudoparticle (pp) system. Native and mismatched virus pps were generated to investigate their biological characteristics. The HAs and NAs of the two viruses reassorted successfully to generate infectious viral particles. H7 was demonstrated to have the ability to reassort with NA from the H5N1 viruses, resulting in the generation of virions that were highly infectious to bronchial epithelial cells. Although the Anhui H5+Anhui N9 combination showed an moderate infectivity to the four cell lines, it was most sensitive to oseltamivir. The H7 in the pps was found to be predominantly HA0. Further, H5 in the pps primarily presented as HA1, owing to the particular mechanisms underlying its maturation. All NAs predominantly existed in monomer form. In our study, HAs/NAs, in all combinations, were functional and able to perform their corresponding function in the viral life cycle. Our data suggest that HAs/NAs from the (HPAI) H5N1 and H7N9 viruses are capable of assembly into infectious virions, posing a threat topublic health. Copyright © 2018 Elsevier B.V. All rights reserved.

Web Prep: How to Prepare NAS Reports For Publication on the Web

NASA Technical Reports Server (NTRS)

Walatka, Pamela; Balakrishnan, Prithika; Clucas, Jean; McCabe, R. Kevin; Felchle, Gail; Brickell, Cristy

1996-01-01

This document contains specific advice and requirements for NASA Ames Code IN authors of NAS reports. Much of the information may be of interest to other authors writing for the Web. WebPrep has a graphic Table of Contents in the form of a WebToon, which simulates a discussion between a scientist and a Web publishing consultant. In the WebToon, Frequently Asked Questions about preparing reports for the Web are linked to relevant text in the body of this document. We also provide a text-only Table of Contents. The text for this document is divided into chapters: each chapter corresponds to one frame of the WebToons. The chapter topics are: converting text to HTML, converting 2D graphic images to gif, creating imagemaps and tables, converting movie and audio files to Web formats, supplying 3D interactive data, and (briefly) JAVA capabilities. The last chapter is specifically for NAS staff authors. The Glossary-Index lists web related words and links to topics covered in the main text.

The Performance of the NAS HSPs in 1st Half of 1994

NASA Technical Reports Server (NTRS)

Bergeron, Robert J.; Walter, Howard (Technical Monitor)

1995-01-01

During the first six months of 1994, the NAS (National Airspace System) 16-CPU Y-MP C90 Von Neumann (VN) delivered an average throughput of 4.045 GFLOPS while the ACSF (Aeronautics Consolidated Supercomputer Facility) 8-CPU Y-MP C90 Eagle averaged 1.658 GFLOPS. The VN rate represents a machine efficiency of 26.3% whereas the Eagle rate corresponds to a machine efficiency of 21.6%. VN displayed a greater efficiency than Eagle primarily because the stronger workload demand for its CPU cycles allowed it to devote more time to user programs and less time to idle. An additional factor increasing VN efficiency was the ability of the UNICOS 8.0 Operating System to deliver a larger fraction of CPU time to user programs. Although measurements indicate increasing vector length for both workloads, insufficient vector lengths continue to hinder HSP (High Speed Processor) performance. To improve HSP performance, NAS should continue to encourage the HSP users to modify their codes to increase program vector length.

Hα Equivalent Widths from the 3D-HST Survey: Evolution with Redshift and Dependence on Stellar Mass

NASA Astrophysics Data System (ADS)

Fumagalli, Mattia; Patel, Shannon G.; Franx, Marijn; Brammer, Gabriel; van Dokkum, Pieter; da Cunha, Elisabete; Kriek, Mariska; Lundgren, Britt; Momcheva, Ivelina; Rix, Hans-Walter; Schmidt, Kasper B.; Skelton, Rosalind E.; Whitaker, Katherine E.; Labbe, Ivo; Nelson, Erica

2012-10-01

We investigate the evolution of the Hα equivalent width, EW(Hα), with redshift and its dependence on stellar mass, using the first data from the 3D-HST survey, a large spectroscopic Treasury program with the Hubble Space Telescope Wide Field Camera 3. Combining our Hα measurements of 854 galaxies at 0.8 < z < 1.5 with those of ground-based surveys at lower and higher redshift, we can consistently determine the evolution of the EW(Hα) distribution from z = 0 to z = 2.2. We find that at all masses the characteristic EW(Hα) is decreasing toward the present epoch, and that at each redshift the EW(Hα) is lower for high-mass galaxies. We find EW(Hα) ~(1 + z)1.8 with little mass dependence. Qualitatively, this measurement is a model-independent confirmation of the evolution of star-forming galaxies with redshift. A quantitative conversion of EW(Hα) to specific star formation rate (sSFR) is model dependent because of differential reddening corrections between the continuum and the Balmer lines. The observed EW(Hα) can be reproduced with the characteristic evolutionary history for galaxies, whose star formation rises with cosmic time to z ~ 2.5 and then decreases to z = 0. This implies that EW(Hα) rises to 400 Å at z = 8. The sSFR evolves faster than EW(Hα), as the mass-to-light ratio also evolves with redshift. We find that the sSFR evolves as (1 + z)3.2, nearly independent of mass, consistent with previous reddening insensitive estimates. We confirm previous results that the observed slope of the sSFR-z relation is steeper than the one predicted by models, but models and observations agree in finding little mass dependence. Based on observations made 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 NAS 5-26555. These observations are associated with programs 12177, 12328.

NAS Decadal Review Town Hall

NASA Astrophysics Data System (ADS)

The National Academies of Sciences, Engineering and Medicine is seeking community input for a study on the future of materials research (MR). Frontiers of Materials Research: A Decadal Survey will look at defining the frontiers of materials research ranging from traditional materials science and engineering to condensed matter physics. Please join members of the study committee for a town hall to discuss future directions for materials research in the United States in the context of worldwide efforts. In particular, input on the following topics will be of great value: progress, achievements, and principal changes in the R&D landscape over the past decade; identification of key MR areas that have major scientific gaps or offer promising investment opportunities from 2020-2030; and the challenges that MR may face over the next decade and how those challenges might be addressed. This study was requested by the Department of Energy and the National Science Foundation. The National Academies will issue a report in 2018 that will offer guidance to federal agencies that support materials research, science policymakers, and researchers in materials research and other adjoining fields. Learn more about the study at http://nas.edu/materials.

The Nucleus of the Planetary Nebula EGB 6 as a Post-Mira Binary

NASA Astrophysics Data System (ADS)

Bond, Howard E.; Ciardullo, Robin; Esplin, Taran L.; Hawley, Steven A.; Liebert, James; Munari, Ulisse

2016-08-01

EGB 6 is a faint, large, ancient planetary nebula (PN). Its central star, a hot DAOZ white dwarf (WD), is a prototype of a rare class of PN nuclei associated with dense, compact emission-line knots. The central star also shows excess fluxes in both the near-infrared (NIR) and mid-infrared (MIR). In a 2013 paper, we used Hubble Space Telescope (HST) images to show that the compact nebula is a point-like source, located 0.″16 (˜118 AU) from the WD. We attributed the NIR excess to an M dwarf companion star, which appeared to coincide with the dense emission knot. We now present new ground-based NIR spectroscopy, showing that the companion is actually a much cooler source with a continuous spectrum, apparently a dust-enshrouded low-luminosity star. New HST images confirm common proper motion of the emission knot and red source with the WD. The I-band, NIR, and MIR fluxes are variable, possibly on timescales as short as days. We can fit the spectral energy distribution (SED) with four blackbodies (the WD, a ˜1850 K NIR component, and MIR dust at 385 and 175 K). Alternatively, we show that the NIR/MIR SED is very similar to that of Class 0/I young stellar objects. We suggest a scenario in which the EGB 6 nucleus is descended from a wide binary similar to the Mira system, in which a portion of the wind from an AGB star was captured into an accretion disk around a companion star; a remnant of this disk has survived to the present time and is surrounded by gas photoionized by UV radiation from the WD. Based in part on data obtained with the NASA/ESA Hubble Space Telescope, obtained by the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Also based in part on observations with the 1.5 m telescope operated by the SMARTS Consortium at Cerro Tololo Inter-American Observatory.

Pressure and PL study of dilute-N GaInNAs films for applications in photovoltaics

NASA Astrophysics Data System (ADS)

Lindberg, George; Fukuda, Miwa; Al Khalfioui, M.; Hossain, Khalid; Sellers, Ian; Weinstein, Bernard

2013-03-01

Multi-junction photovoltaic devices employing dilute-N GaInNAs alloys are currently of high interest for efficient solar energy conversion. The negative band-bowing produced by introducing a few percent N into GaInAs provides a convenient way to match the 1eV component of the solar spectrum, providing recombination losses in localized states can be reduced while maintaining favorable carrier extraction. High pressure photoluminescence (PL) experiments exploring the localization of band-edge excitons in dilute-N GaInNAs films grown by plasma assisted MBE will be discussed. The effects of post-growth annealing and hydrogen incorporation on the PL spectra of the films are considered. Research supported by Amethyst Research Inc. through the State of Oklahoma, ONAP program.

Characterization and modeling of the intrinsic properties of 1.5-micrometer gallium indium nitrogen arsenic antimonide/gallium arsenide laser

NASA Astrophysics Data System (ADS)

Goddard, Lynford

2005-12-01

Low cost access to optical communication networks is needed to satisfy the rapidly increasing demands of home-based high-speed Internet. Existing light sources in the low-loss 1.2--1.6mum telecommunication wavelength bandwidth are prohibitively expensive for large-scale deployment, e.g. incorporation in individual personal computers. Recently, we have extended the lasing wavelength of room-temperature CW GaInNAs(Sb) lasers grown monolithically on GaAs by MBE up to 1.52mum in an effort to replace the traditional, more expensive, InP-based devices. Besides lower cost wafers, GaInNAs(Sb) opto-electronic devices have fundamental material advantages over InP-based devices: a larger conduction band offset which reduces temperature sensitivity and enhances differential gain, a lattice match to a material with a large refractive index contrast, i.e. AlAs, which decreases the necessary number of mirror pairs in DBRs for VCSELs, and native oxide apertures for current confinement. High performance GaInNAs(Sb) edge-emitting lasers, VCSELs, and DFB lasers have been demonstrated throughout the entire telecommunication band. In this work, we analyze the intrinsic properties of the GaInNAsSb material system, e.g. recombination, gain, band structure and renormalization, and efficiency. Theoretical modeling is performed to calculate a map of the bandgap and effective masses for various material compositions. We also present device performance results, such as: room temperature CW threshold densities below 450A/cm2, quantum efficiencies above 50%, and over 425mW of total power from a SQW laser when mounted epi-up and minimally packaged. These results are generally 2--4x better than previous world records for GaAs based devices at 1.5mum. The high CW power and low threshold exhibited by these SQW lasers near 1.5mum make feasible many novel applications, such as broadband Raman fiber amplifiers and uncooled WDM at the chip scale. Device reliability of almost 500 hours at 200mW CW

Tn5Prime, a Tn5 based 5' capture method for single cell RNA-seq.

PubMed

Cole, Charles; Byrne, Ashley; Beaudin, Anna E; Forsberg, E Camilla; Vollmers, Christopher

2018-06-01

RNA-sequencing (RNA-seq) is a powerful technique to investigate and quantify entire transcriptomes. Recent advances in the field have made it possible to explore the transcriptomes of single cells. However, most widely used RNA-seq protocols fail to provide crucial information regarding transcription start sites. Here we present a protocol, Tn5Prime, that takes advantage of the Tn5 transposase-based Smart-seq2 protocol to create RNA-seq libraries that capture the 5' end of transcripts. The Tn5Prime method dramatically streamlines the 5' capture process and is both cost effective and reliable. By applying Tn5Prime to bulk RNA and single cell samples, we were able to define transcription start sites as well as quantify transcriptomes at high accuracy and reproducibility. Additionally, similar to 3' end-based high-throughput methods like Drop-seq and 10× Genomics Chromium, the 5' capture Tn5Prime method allows the introduction of cellular identifiers during reverse transcription, simplifying the analysis of large numbers of single cells. In contrast to 3' end-based methods, Tn5Prime also enables the assembly of the variable 5' ends of the antibody sequences present in single B-cell data. Therefore, Tn5Prime presents a robust tool for both basic and applied research into the adaptive immune system and beyond.

Weather Requirements and Procedures for Step 1: High Altitude Long Endurance (HALE) Unmanned Aircraft System (UAS) Flight Operations in the National Air Space (NAS)

NASA Technical Reports Server (NTRS)

2007-01-01

This cover sheet is for version 2 of the weather requirements document along with Appendix A. The purpose of the requirements document was to identify and to list the weather functional requirements needed to achieve the Access 5 vision of "operating High Altitude, Long Endurance (HALE) Unmanned Aircraft Systems (UAS) routinely, safely, and reliably in the National Airspace System (NAS) for Step 1." A discussion of the Federal Aviation Administration (FAA) references and related policies, procedures, and standards is provided as basis for the recommendations supported within this document. Additional procedures and reference documentation related to weather functional requirements is also provided for background. The functional requirements and related information are to be proposed to the FAA and various standards organizations for consideration and approval. The appendix was designed to show that sources of flight weather information are readily available to UAS pilots conducting missions in the NAS. All weather information for this presentation was obtained from the public internet.

48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

Code of Federal Regulations, 2013 CFR

2013-10-01

... “Network Analysis System (NAS).” Payments Under Fixed-Price Construction Contracts (APR 1984) The clause..., as applied to each branch, shall equal the total cost of such branch. The total cost of all branches... readily available for inspection and inventory by the resident engineer. (4) Such materials and/or...

48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

Code of Federal Regulations, 2011 CFR

2011-10-01

... “Network Analysis System (NAS).” Payments Under Fixed-Price Construction Contracts (APR 1984) The clause..., as applied to each branch, shall equal the total cost of such branch. The total cost of all branches... readily available for inspection and inventory by the resident engineer. (4) Such materials and/or...

48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

Code of Federal Regulations, 2012 CFR

2012-10-01

... “Network Analysis System (NAS).” Payments Under Fixed-Price Construction Contracts (APR 1984) The clause..., as applied to each branch, shall equal the total cost of such branch. The total cost of all branches... readily available for inspection and inventory by the resident engineer. (4) Such materials and/or...

48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

Code of Federal Regulations, 2014 CFR

2014-10-01

... “Network Analysis System (NAS).” Payments Under Fixed-Price Construction Contracts (APR 1984) The clause..., as applied to each branch, shall equal the total cost of such branch. The total cost of all branches... readily available for inspection and inventory by the resident engineer. (4) Such materials and/or...

Pixel-by-Pixel SED Fitting of Intermediate Redshift Galaxies

NASA Astrophysics Data System (ADS)

Cohen, Seth H.; Kim, Hwihyun; Petty, Sara M.; Farrah, Duncan

2015-01-01

We select intermediate redshift galaxies from the Hubble Space Telescope CANDELS and GOODS surveys to study their stellar populations on sub-kilo-parsec scales by fitting SED models on a pixel-by-pixel basis. Galaxies are chosen to have measured spectroscopic redshifts (z<1.5), to be bright (H_AB<21 mag), to be relatively face-on (b/a > 0.6), and have a minimum of ten individual resolution elements across the face of the galaxy, as defined by the broadest PSF (F160W-band) in the data. The sample contains ~200 galaxies with BViz(Y)JH band HST photometry. The main goal of the study is to better understand the effects of population blending when using a pixel-by-pixel SED fitting (pSED) approach. We outline our pSED fitting method which gives maps of stellar mass, age, star-formation rate, etc. Several examples of individual pSED-fit maps are presented in detail, as well as some preliminary results on the full sample. The pSED method is necessarily biased by the brightest population in a given pixel outshining the rest of the stars, and, therefore, we intend to study this apparent population blending in a set of artificially redshifted images of nearby galaxies, for which we have star-by-star measurements of their stellar populations. This local sample will be used to better interpret the measurements for the higher redshift galaxies.Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. This archival research is associated with program #13241.

A Chemical Composition Survey of the Iron-complex Globular Cluster NGC 6273 (M19)

NASA Astrophysics Data System (ADS)

Johnson, Christian I.; Caldwell, Nelson; Rich, R. Michael; Mateo, Mario; Bailey, John I., III; Clarkson, William I.; Olszewski, Edward W.; Walker, Matthew G.

2017-02-01

Recent observations have shown that a growing number of the most massive Galactic globular clusters contain multiple populations of stars with different [Fe/H] and neutron-capture element abundances. NGC 6273 has only recently been recognized as a member of this “iron-complex” cluster class, and we provide here a chemical and kinematic analysis of >300 red giant branch and asymptotic giant branch member stars using high-resolution spectra obtained with the Magellan-M2FS and VLT-FLAMES instruments. Multiple lines of evidence indicate that NGC 6273 possesses an intrinsic metallicity spread that ranges from about [Fe/H] = -2 to -1 dex, and may include at least three populations with different [Fe/H] values. The three populations identified here contain separate first (Na/Al-poor) and second (Na/Al-rich) generation stars, but a Mg-Al anti-correlation may only be present in stars with [Fe/H] ≳ -1.65. The strong correlation between [La/Eu] and [Fe/H] suggests that the s-process must have dominated the heavy element enrichment at higher metallicities. A small group of stars with low [α/Fe] is identified and may have been accreted from a former surrounding field star population. The cluster’s large abundance variations are coupled with a complex, extended, and multimodal blue horizontal branch (HB). The HB morphology and chemical abundances suggest that NGC 6273 may have an origin that is similar to ω Cen and M54. Based on observations made 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 NAS 5-26555. These observations are associated with program GO-14197. This paper includes data gathered with the 6.5 m Magellan Telescopes located as Las Campanas Observatory, Chile.

A Peculiar Faint Satellite in the Remote Outer Halo of M31

NASA Astrophysics Data System (ADS)

Mackey, A. D.; Huxor, A. P.; Martin, N. F.; Ferguson, A. M. N.; Dotter, A.; McConnachie, A. W.; Ibata, R. A.; Irwin, M. J.; Lewis, G. F.; Sakari, C. M.; Tanvir, N. R.; Venn, K. A.

2013-06-01

We present Hubble Space Telescope imaging of a newly discovered faint stellar system, PAndAS-48, in the outskirts of the M31 halo. Our photometry reveals this object to be comprised of an ancient and very metal-poor stellar population with age >~ 10 Gyr and [Fe/H] lsim -2.3. Our inferred distance modulus (m - M)0 = 24.57 ± 0.11 confirms that PAndAS-48 is most likely a remote M31 satellite with a three-dimensional galactocentric radius of 149^{+19}_{-8} kpc. We observe an apparent spread in color on the upper red giant branch that is larger than the photometric uncertainties should allow, and briefly explore the implications of this. Structurally, PAndAS-48 is diffuse, faint, and moderately flattened, with a half-light radius r_h=26^{+4}_{-3} pc, integrated luminosity MV = -4.8 ± 0.5, and ellipticity \\epsilon =0.30^{+0.08}_{-0.15}. On the size-luminosity plane it falls between the extended globular clusters seen in several nearby galaxies and the recently discovered faint dwarf satellites of the Milky Way; however, its characteristics do not allow us to unambiguously classify it as either type of system. If PAndAS-48 is a globular cluster then it is among the most elliptical, isolated, and metal-poor of any seen in the Local Group, extended or otherwise. Conversely, while its properties are generally consistent with those observed for the faint Milky Way dwarfs, it would be a factor of ~2-3 smaller in spatial extent than any known counterpart of comparable luminosity. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO 12515.

Discovery of a Strong Lensing Galaxy Embedded in a Cluster at z = 1.62

NASA Astrophysics Data System (ADS)

Wong, Kenneth C.; Tran, Kim-Vy H.; Suyu, Sherry H.; Momcheva, Ivelina G.; Brammer, Gabriel B.; Brodwin, Mark; Gonzalez, Anthony H.; Halkola, Aleksi; Kacprzak, Glenn G.; Koekemoer, Anton M.; Papovich, Casey J.; Rudnick, Gregory H.

2014-07-01

We identify a strong lensing galaxy in the cluster IRC 0218 (also known as XMM-LSS J02182-05102) that is spectroscopically confirmed to be at z = 1.62, making it the highest-redshift strong lens galaxy known. The lens is one of the two brightest cluster galaxies and lenses a background source galaxy into an arc and a counterimage. With Hubble Space Telescope (HST) grism and Keck/LRIS spectroscopy, we measure the source redshift to be z S = 2.26. Using HST imaging in ACS/F475W, ACS/F814W, WFC3/F125W, and WFC3/F160W, we model the lens mass distribution with an elliptical power-law profile and account for the effects of the cluster halo and nearby galaxies. The Einstein radius is θ _E=0.38+0.02-0.01 arcsec (3.2-0.1+0.2 kpc) and the total enclosed mass is M _tot (< θ _E)=1.8+0.2-0.1× 1011 M⊙ . We estimate that the cluster environment contributes ~10% of this total mass. Assuming a Chabrier initial mass function (IMF), the dark matter fraction within θE is f_DMChab = 0.3-0.3+0.1, while a Salpeter IMF is marginally inconsistent with the enclosed mass (f_DMSalp = -0.3-0.5+0.2). The total magnification of the source is μ _tot=2.1-0.3+0.4. The source has at least one bright compact region offset from the source center. Emission from Lyα and [O III] are likely to probe different regions in the source. Based on observations made 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 NAS 5-26555. These observations are associated with program No. 12590.

HST/COS Detection of the Spectrum of the Subdwarf Companion of KOI-81

NASA Astrophysics Data System (ADS)

Matson, Rachel A.; Gies, Douglas R.; Guo, Zhao; Quinn, Samuel N.; Buchhave, Lars A.; Latham, David W.; Howell, Steve B.; Rowe, Jason F.

2015-06-01

KOI-81 is a totally eclipsing binary discovered by the Kepler mission that consists of a rapidly rotating B-type star and a small, hot companion. The system was forged through large-scale mass transfer that stripped the mass donor of its envelope and spun up the mass gainer star. We present an analysis of UV spectra of KOI-81 that were obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope that reveal for the first time the spectral features of the faint, hot companion. We present a double-lined spectroscopic orbit for the system that yields mass estimates of 2.92 {{M}⊙ } and 0.19 {{M}⊙ } for the B-star and hot subdwarf, respectively. We used a Doppler tomography algorithm to reconstruct the UV spectra of the components, and a comparison of the reconstructed and model spectra yields effective temperatures of 12 and 19-27 kK for the B-star and hot companion, respectively. The B-star is pulsating, and we identified a number of peaks in the Fourier transform of the light curve, including one that may indicate an equatorial rotation period of 11.5 hr. The B-star has an equatorial velocity that is 74% of the critical velocity where centrifugal and gravitational accelerations balance at the equator, and we fit the transit light curve by calculating a rotationally distorted model for the photosphere of the B-star. Based on observations made 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 NAS 5-26555. These observations are associated with program #12288.

Star Formation Histories of the LEGUS Dwarf Galaxies. I. Recent History of NGC 1705, NGC 4449, and Holmberg II

NASA Astrophysics Data System (ADS)

Cignoni, M.; Sacchi, E.; Aloisi, A.; Tosi, M.; Calzetti, D.; Lee, J. C.; Sabbi, E.; Adamo, A.; Cook, D. O.; Dale, D. A.; Elmegreen, B. G.; Gallagher, J. S., III; Gouliermis, D. A.; Grasha, K.; Grebel, E. K.; Hunter, D. A.; Johnson, K. E.; Messa, M.; Smith, L. J.; Thilker, D. A.; Ubeda, L.; Whitmore, B. C.

2018-03-01

We use Hubble Space Telescope observations from the Legacy Extragalactic UV Survey to reconstruct the recent star formation histories (SFHs) of three actively star-forming dwarf galaxies, NGC 4449, Holmberg II, and NGC 1705, from their UV color–magnitude diagrams (CMDs). We apply a CMD fitting technique using two independent sets of stellar isochrones, PARSEC-COLIBRI and MIST, to assess the uncertainties related to stellar evolution modeling. Irrespective of the adopted stellar models, all three dwarfs are found to have had almost constant star formation rates (SFRs) in the last 100–200 Myr, with modest enhancements (a factor of ∼2) above the 100 Myr averaged SFR. Significant differences among the three dwarfs are found in terms of the overall SFR, the timing of the most recent peak, and the SFR/area. The initial mass function of NGC 1705 and Holmberg II is consistent with a Salpeter slope down to ≈5 M ⊙, whereas it is slightly flatter, s = ‑2.0, in NGC 4449. The SFHs derived with the two different sets of stellar models are consistent with each other, except for some quantitative details, attributable to their input assumptions. They also share the drawback that all synthetic diagrams predict a clear separation in color between the upper main-sequence and helium-burning stars, which is not apparent in the data. Since neither differential reddening, which is significant in NGC 4449, nor unresolved binaries appear to be sufficient to fill the gap, we suggest this calls for a revision of both sets of stellar evolutionary tracks. Based on observations obtained with the NASA/ESA Hubble Space Telescope at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy under NASA Contract NAS 5-26555.

Boron Abundances Across the “Li-Be Dip” in the Hyades Cluster

NASA Astrophysics Data System (ADS)

Boesgaard, Ann Merchant; Lum, Michael G.; Deliyannis, Constantine P.; King, Jeremy R.; Pinsonneault, Marc H.; Somers, Garrett

2016-10-01

Dramatic deficiencies of Li in the mid-F dwarf stars of the Hyades cluster were discovered by Boesgaard & Tripicco. Boesgaard & King discovered corresponding, but smaller, deficiencies in Be in the same narrow temperature region in the Hyades. Using the Space Telescope Imaging Spectrograph on the Hubble Space Telescope, we investigate B abundances in the Hyades F stars to look for a potential B dip using the B I resonance line at 2496.8 Å. The light elements Li, Be, and B are destroyed inside stars at increasingly hotter temperatures: 2.5, 3.5, and 5 × 106 K, respectively. Consequently, these elements survive to increasingly greater depths in a star and their surface abundances indicate the depth and thoroughness of mixing in the star. We have (re)determined Li abundances/upper limits for 79 Hyades dwarfs, Be for 43 stars, and B for 5 stars. We find evidence for a small drop in the B abundance across the Li-Be dip. The B abundances for the four stars in the temperature range 6100-6730 K fit the B-Be correlation found previously by Boesgaard et al. Models of rotational mixing produce good agreement with the relative depletions of Be and B in the dip region. We have compared our nLTE B abundances for the three high B stars on either side of the Li-Be dip with those found by Duncan et al. for the two Hyades giants. This confirms the factor of 10 decline in the B abundance in the Hyades giants as predicted by dilution due to the deepening of the surface convection zone. Based on observations made 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 NAS 5-26555. These observations are associated with program #HST-G0-12294.

48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

Code of Federal Regulations, 2013 CFR

2013-10-01

... shall show on the critical path method (CPM) network the total cost of the guarantee period services in... prescribed in 832.111, insert the following clause in contracts that contain a section entitled “Network...) Failure either to meet schedules in Section Network Analysis System (NAS), or to process the Interim Arrow...

48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

Code of Federal Regulations, 2014 CFR

2014-10-01

... shall show on the critical path method (CPM) network the total cost of the guarantee period services in... prescribed in 832.111, insert the following clause in contracts that contain a section entitled “Network...) Failure either to meet schedules in Section Network Analysis System (NAS), or to process the Interim Arrow...

48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

Code of Federal Regulations, 2012 CFR

2012-10-01

... shall show on the critical path method (CPM) network the total cost of the guarantee period services in... prescribed in 832.111, insert the following clause in contracts that contain a section entitled “Network...) Failure either to meet schedules in Section Network Analysis System (NAS), or to process the Interim Arrow...

Astrometry, Radial Velocity, and Photometry: The HD 128311 System Remixed with Data from HST, HET, and APT

NASA Astrophysics Data System (ADS)

McArthur, Barbara. E.; Benedict, G. Fritz; Henry, Gregory W.; Hatzes, Artie; Cochran, William D.; Harrison, Tom E.; Johns-Krull, Chris; Nelan, Ed

2014-11-01

We have used high-cadence radial velocity measurements from the Hobby-Eberly Telescope with published velocities from the Lick 3 m Shane Telescope, combined with astrometric data from the Hubble Space Telescope (HST) Fine Guidance Sensors to refine the orbital parameters of the HD 128311 system, and determine an inclination of 55.°95 ± 14.°55 and true mass of 3.789 +0.924 -0.432 M JUP for HD 128311 c. The combined radial velocity data also reveal a short period signal which could indicate a third planet in the system with an Msin i of 0.133 ± 0.005 M JUP or stellar phenomena. Photometry from the T12 0.8 m automatic photometric telescope at the Fairborn Observatory and HST are used to determine a photometric period close to, but not within the errors of the radial velocity signal. We performed a cross-correlation bisector analysis of the radial velocity data to look for correlations with the photometric period and found none. Dynamical integrations of the proposed system show long-term stability with the new orbital parameters of over 10 million years. Our new orbital elements do not support the claims of HD 128311 b and c being in mean motion resonance. Based on observations made 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. Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen, and observations with T12 0.8 m automatic photoelectric telescope (APT) at Fairborn Observatory.

Expansion of Hydrogen-poor Knots in the Born-again Planetary Nebulae A30 and A78

NASA Astrophysics Data System (ADS)

Fang, X.; Guerrero, M. A.; Marquez-Lugo, R. A.; Toalá, J. A.; Arthur, S. J.; Chu, Y.-H.; Blair, W. P.; Gruendl, R. A.; Hamann, W.-R.; Oskinova, L. M.; Todt, H.

2014-12-01

We analyze the expansion of hydrogen-poor knots and filaments in the born-again planetary nebulae A30 and A78 based on Hubble Space Telescope (HST) images obtained almost 20 yr apart. The proper motion of these features generally increases with distance to the central star, but the fractional expansion decreases, i.e., the expansion is not homologous. As a result, there is not a unique expansion age, which is estimated to be 610-950 yr for A30 and 600-1140 yr for A78. The knots and filaments have experienced complex dynamical processes: the current fast stellar wind is mass loaded by the material ablated from the inner knots; the ablated material is then swept up until it shocks the inner edges of the outer, hydrogen-rich nebula. The angular expansion of the outer filaments shows a clear dependence on position angle, indicating that the interaction of the stellar wind with the innermost knots channels the wind along preferred directions. The apparent angular expansion of the innermost knots seems to be dominated by the rocket effect of evaporating gas and by the propagation of the ionization front inside them. Radiation-hydrodynamical simulations show that a single ejection of material followed by a rapid onset of the stellar wind and ionizing flux can reproduce the variety of clumps and filaments at different distances from the central star found in A30 and A78. Based on observations made 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 NAS 5-26555. These observations are associated with program No. 12935.

Great IDEAS: Telescopes, Computers, and Education

NASA Astrophysics Data System (ADS)

Nook, M. A.; Williams, D. L.

1999-05-01

Two workshops were developed for k-12 teachers that take advantage of the excitement students esperience when viewing objects through a telescope for the first time and the growth in educational opportunities that the internet has generated. The observational astronomy workshop focused on teaching educators a few basics about naked-eye, binocular, and small telescope observing; while the computers in astronomy education workshop taught teachers to develop simple web sites and permitted them to test astronomy software. The observational astronomy workshop met for three days on the SCSU campus to teach basic celestial motions, several constellations, and the basic operation of small telescopes. The next four nights were spent at Camden State Park in southwest Minnesota learning to locate deep sky objects and preparing public presentations. The final two nights the teachers presented public observing programs at three state parks. Fifty percent of the teachers implemented night observing into their curriculum this past year, and one teacher purchased her own telescope to use with students and to help other teachers in the district. The computers in astronomy workshop introduced the teachers to several commercially available astronomy software packages and taught them the fundamentals of constructing simple web pages. The participants were required to develop astronomy lessons based on one of the software packages or a web site that they developed. Each participant then constructed a web-based lesson plan, student lesson, and teacher's guide for their lesson. These lessons are available at http://enstein.stcloudstate.edu/nook/IDEAS/computers/. Support for this work was provided by NASA through grant numbers ED-90156.01-97A and ED-90157.01-97A from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555.

A Cluster Of Activities On Coma From The Hubble Space Telescope, StarDate, And McDonald Observatory

NASA Astrophysics Data System (ADS)

Hemenway, Mary Kay; Jogee, S.; Fricke, K.; Preston, S.

2011-01-01

With a goal of providing a vast audience of students, teachers, the general public, and Spanish-speakers with activities to learn about research on the Coma cluster of galaxies based on the HST ACS Treasury survey of Coma, McDonald Observatory used a many-faceted approach. Since this research offered an unprecedented legacy dataset, part of the challenge was to convey the importance of this project to a diverse audience. The methodology was to create different products for different (overlapping) audiences. Five radio programs were produced in English and Spanish for distribution on over 500 radio stations in the US and Mexico with a listening audience of over 2 million; in addition to the radio listeners, there were over 13,000 downloads of the English scripts and almost 6000 of the Spanish. Images were prepared for use in the StarDate Online Astronomy Picture of the Week, for ViewSpace (used in museums), and for the StarDate/Universo Teacher Guide. A high-school level activity on the Coma Cluster was prepared and distributed both on-line and in an upgraded printed version of the StarDate/Universo Teacher Guide. This guide has been distributed to over 1700 teachers nationally. A YouTube video about careers and research in astronomy using the Coma cluster as an example was produced. Just as the activities were varied, so were the evaluation methods. This material is based upon work supported by the National Aeronautics and Space Administration under Grant/Contract/Agreement No. HST-EO-10861.35-A issued through the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Jellyfish: Evidence of Extreme Ram-pressure Stripping in Massive Galaxy Clusters

NASA Astrophysics Data System (ADS)

Ebeling, H.; Stephenson, L. N.; Edge, A. C.

2014-02-01

Ram-pressure stripping by the gaseous intracluster medium has been proposed as the dominant physical mechanism driving the rapid evolution of galaxies in dense environments. Detailed studies of this process have, however, largely been limited to relatively modest examples affecting only the outermost gas layers of galaxies in nearby and/or low-mass galaxy clusters. We here present results from our search for extreme cases of gas-galaxy interactions in much more massive, X-ray selected clusters at z > 0.3. Using Hubble Space Telescope snapshots in the F606W and F814W passbands, we have discovered dramatic evidence of ram-pressure stripping in which copious amounts of gas are first shock compressed and then removed from galaxies falling into the cluster. Vigorous starbursts triggered by this process across the galaxy-gas interface and in the debris trail cause these galaxies to temporarily become some of the brightest cluster members in the F606W passband, capable of outshining even the Brightest Cluster Galaxy. Based on the spatial distribution and orientation of systems viewed nearly edge-on in our survey, we speculate that infall at large impact parameter gives rise to particularly long-lasting stripping events. Our sample of six spectacular examples identified in clusters from the Massive Cluster Survey, all featuring M F606W < -21 mag, doubles the number of such systems presently known at z > 0.2 and facilitates detailed quantitative studies of the most violent galaxy evolution in clusters. Based on observations made 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 NAS 5-26555. These observations are associated with programs GO-10491, -10875, -12166, and -12884.

Chemically Dissected Rotation Curves of the Galactic Bulge from Main-sequence Proper Motions

NASA Astrophysics Data System (ADS)

Clarkson, William I.; Calamida, Annalisa; Sahu, Kailash C.; Brown, Thomas M.; Gennaro, Mario; Avila, Roberto J.; Valenti, Jeff; Debattista, Victor P.; Rich, R. Michael; Minniti, Dante; Zoccali, Manuela; Aufdemberge, Emily R.

2018-05-01

We report results from an exploratory study implementing a new probe of Galactic evolution using archival Hubble Space Telescope imaging observations. Precise proper motions are combined with photometric relative metallicity and temperature indices, to produce the proper-motion rotation curves of the Galactic bulge separately for metal-poor and metal-rich main-sequence samples. This provides a “pencil-beam” complement to large-scale wide-field surveys, which to date have focused on the more traditional bright giant branch tracers. We find strong evidence that the Galactic bulge rotation curves drawn from “metal-rich” and “metal-poor” samples are indeed discrepant. The “metal-rich” sample shows greater rotation amplitude and a steeper gradient against line-of-sight distance, as well as possibly a stronger central concentration along the line of sight. This may represent a new detection of differing orbital anisotropy between metal-rich and metal-poor bulge objects. We also investigate selection effects that would be implied for the longitudinal proper-motion cut often used to isolate a “pure-bulge” sample. Extensive investigation of synthetic stellar populations suggests that instrumental and observational artifacts are unlikely to account for the observed rotation curve differences. Thus, proper-motion-based rotation curves can be used to probe chemodynamical correlations for main-sequence tracer stars, which are orders of magnitude more numerous in the Galactic bulge than the bright giant branch tracers. We discuss briefly the prospect of using this new tool to constrain detailed models of Galactic formation and evolution. Based on observations made with the NASA/ESA Hubble Space Telescope and obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

VLT adaptive optics search for luminous substructures in the lens galaxy towards SDSS J0924+0219

NASA Astrophysics Data System (ADS)

Faure, C.; Sluse, D.; Cantale, N.; Tewes, M.; Courbin, F.; Durrer, P.; Meylan, G.

2011-12-01

The anomalous flux ratios between quasar images are suspected of being caused by substructures in lens galaxies. We present new deep and high-resolution H and Ks imaging of the strongly lensed quasar SDSS J0924+0219 obtained using the ESO VLT with adaptive optics and the laser guide star system. SDSS J0924+0219 is particularly interesting because the observed flux ratio between the quasar images vastly disagree with the predictions from smooth mass models. With our adaptive optics observations we find a luminous object, Object L, located ~0.3'' to the north of the lens galaxy, but we show that it cannot be responsible for the anomalous flux ratios. Object L as well as a luminous extension of the lens galaxy to the south are seen in the archival HST/ACS image in the F814W filter. This suggests that Object L is part of a bar in the lens galaxy, as also supported by the presence of a significant disk component in the light profile of the lens galaxy. Finally, we find no evidence of any other luminous substructure that may explain the quasar images flux ratios. However, owing to the persistence of the flux ratio anomaly over time (~7 years), a combination of microlensing and millilensing is the favorite explanation for the observations. Based on observations obtained with the ESO VLT at Paranal observatory (Prog ID 084.A-0762(A); PI: Meylan). Also based in part on observations made 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 NAS 5-26555. These observations are associated with the CASTLES (Cfa-Arizona Space Telescope LEns Survey) survey (ID: 9744, PI: C. S. Kochanek).

HD 140283: A Star in the Solar Neighborhood that Formed Shortly after the Big Bang

NASA Astrophysics Data System (ADS)

Bond, Howard E.; Nelan, Edmund P.; VandenBerg, Don A.; Schaefer, Gail H.; Harmer, Dianne

2013-03-01

HD 140283 is an extremely metal-deficient and high-velocity subgiant in the solar neighborhood, having a location in the Hertzsprung-Russell diagram where absolute magnitude is most sensitive to stellar age. Because it is bright, nearby, unreddened, and has a well-determined chemical composition, this star avoids most of the issues involved in age determinations for globular clusters. Using the Fine Guidance Sensors on the Hubble Space Telescope, we have measured a trigonometric parallax of 17.15 ± 0.14 mas for HD 140283, with an error one-fifth of that determined by the Hipparcos mission. Employing modern theoretical isochrones, which include effects of helium diffusion, revised nuclear reaction rates, and enhanced oxygen abundance, we use the precise distance to infer an age of 14.46 ± 0.31 Gyr. The quoted error includes only the uncertainty in the parallax, and is for adopted surface oxygen and iron abundances of [O/H] = -1.67 and [Fe/H] = -2.40. Uncertainties in the stellar parameters and chemical composition, especially the oxygen content, now contribute more to the error budget for the age of HD 140283 than does its distance, increasing the total uncertainty to about ±0.8 Gyr. Within the errors, the age of HD 140283 does not conflict with the age of the Universe, 13.77 ± 0.06 Gyr, based on the microwave background and Hubble constant, but it must have formed soon after the big bang. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained by the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

The Dearth of z ∼ 10 Galaxies in All HST Legacy Fields—The Rapid Evolution of the Galaxy Population in the First 500 Myr

NASA Astrophysics Data System (ADS)

Oesch, P. A.; Bouwens, R. J.; Illingworth, G. D.; Labbé, I.; Stefanon, M.

2018-03-01

We present an analysis of all prime HST legacy fields spanning >800 arcmin2 in the search for z ∼ 10 galaxy candidates and the study of their UV luminosity function (LF). In particular, we present new z ∼ 10 candidates selected from the full Hubble Frontier Field (HFF) data set. Despite the addition of these new fields, we find a low abundance of z ∼ 10 candidates with only nine reliable sources identified in all prime HST data sets that include the HUDF09/12, the HUDF/XDF, all of the CANDELS fields, and now the HFF survey. Based on this comprehensive search, we find that the UV luminosity function decreases by one order of magnitude from z ∼ 8 to z ∼ 10 over a four-magnitude range. This also implies a decrease of the cosmic star formation rate density by an order of magnitude within 170 Myr from z ∼ 8 to z ∼ 10. We show that this accelerated evolution compared to lower redshift can entirely be explained by the fast build up of the dark matter halo mass function at z > 8. Consequently, the predicted UV LFs from several models of galaxy formation are in good agreement with this observed trend, even though the measured UV LF lies at the low end of model predictions. The difference is generally still consistent within the Poisson and cosmic variance uncertainties. We discuss the implications of these results in light of the upcoming James Webb Space Telescope mission, which is poised to find much larger samples of z ∼ 10 galaxies as well as their progenitors at less than 400 Myr after the big bang. Based on data obtained with the Hubble Space Telescope operated by AURA, Inc. for NASA under contract NAS5-26555.

The ISLAnds Project. III. Variable Stars in Six Andromeda Dwarf Spheroidal Galaxies

NASA Astrophysics Data System (ADS)

Martínez-Vázquez, Clara E.; Monelli, Matteo; Bernard, Edouard J.; Gallart, Carme; Stetson, Peter B.; Skillman, Evan D.; Bono, Giuseppe; Cassisi, Santi; Fiorentino, Giuliana; McQuinn, Kristen B. W.; Cole, Andrew A.; McConnachie, Alan W.; Martin, Nicolas F.; Dolphin, Andrew E.; Boylan-Kolchin, Michael; Aparicio, Antonio; Hidalgo, Sebastian L.; Weisz, Daniel R.

2017-12-01

We present a census of variable stars in six M31 dwarf spheroidal satellites observed with the Hubble Space Telescope. We detect 870 RR Lyrae (RRL) stars in the fields of And I (296), II (251), III (111), XV (117), XVI (8), and XXVIII (87). We also detect a total of 15 Anomalous Cepheids, three eclipsing binaries, and seven field RRL stars compatible with being members of the M31 halo or the Giant Stellar Stream. We derive robust and homogeneous distances to the six galaxies using different methods based on the properties of the RRL stars. Working with the up-to-date set of Period-Wesenheit (I, B-I) relations published by Marconi et al., we obtain distance moduli of μ 0 = [24.49, 24.16, 24.36, 24.42, 23.70, 24.43] mag (respectively), with systematic uncertainties of 0.08 mag and statistical uncertainties <0.11 mag. We have considered an enlarged sample of 16 M31 satellites with published variability studies, and compared their pulsational observables (e.g., periods and amplitudes) with those of 15 Milky Way satellites for which similar data are available. The properties of the (strictly old) RRL in both satellite systems do not show any significant difference. In particular, we found a strikingly similar correlation between the mean period distribution of the fundamental RRL pulsators (RRab) and the mean metallicities of the galaxies. This indicates that the old RRL progenitors were similar at the early stage in the two environments, suggesting very similar characteristics for the earliest stages of evolution of both satellite systems. Based on observations made 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 NAS 5-26555. These observations are associated with programs 13028 and 13739.

Scaling Relations and Overabundance of Massive Clusters at z >~ 1 from Weak-lensing Studies with the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Jee, M. J.; Dawson, K. S.; Hoekstra, H.; Perlmutter, S.; Rosati, P.; Brodwin, M.; Suzuki, N.; Koester, B.; Postman, M.; Lubin, L.; Meyers, J.; Stanford, S. A.; Barbary, K.; Barrientos, F.; Eisenhardt, P.; Ford, H. C.; Gilbank, D. G.; Gladders, M. D.; Gonzalez, A.; Harris, D. W.; Huang, X.; Lidman, C.; Rykoff, E. S.; Rubin, D.; Spadafora, A. L.

2011-08-01

We present weak gravitational lensing analysis of 22 high-redshift (z >~ 1) clusters based on Hubble Space Telescope images. Most clusters in our sample provide significant lensing signals and are well detected in their reconstructed two-dimensional mass maps. Combining the current results and our previous weak-lensing studies of five other high-z clusters, we compare gravitational lensing masses of these clusters with other observables. We revisit the question whether the presence of the most massive clusters in our sample is in tension with the current ΛCDM structure formation paradigm. We find that the lensing masses are tightly correlated with the gas temperatures and establish, for the first time, the lensing mass-temperature relation at z >~ 1. For the power-law slope of the M-TX relation (MvpropT α), we obtain α = 1.54 ± 0.23. This is consistent with the theoretical self-similar prediction α = 3/2 and with the results previously reported in the literature for much lower redshift samples. However, our normalization is lower than the previous results by 20%-30%, indicating that the normalization in the M-TX relation might evolve. After correcting for Eddington bias and updating the discovery area with a more conservative choice, we find that the existence of the most massive clusters in our sample still provides a tension with the current ΛCDM model. The combined probability of finding the four most massive clusters in this sample after the marginalization over cosmological parameters is less than 1%. Based on observations made 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 NAS 5-26555, under program 9290, 9919, and 10496.

The Secret Lives of Cepheids: Evolution, Mass-Loss, and Ultraviolet Emission of the Long-period Classical Cepheid

NASA Astrophysics Data System (ADS)

Neilson, Hilding R.; Engle, Scott G.; Guinan, Edward F.; Bisol, Alexandra C.; Butterworth, Neil

2016-06-01

The classical Cepheid l Carinae is an essential calibrator of the Cepheid Leavitt Law as a rare long-period Galactic Cepheid. Understanding the properties of this star will also constrain the physics and evolution of massive (M ≥ 8 M ⊙) Cepheids. The challenge, however, is precisely measuring the star's pulsation period and its rate of period change. The former is important for calibrating the Leavitt Law and the latter for stellar evolution modeling. In this work, we combine previous time-series observations spanning more than a century with new observations to remeasure the pulsation period and compute the rate of period change. We compare our new rate of period change with stellar evolution models to measure the properties of l Car, but find models and observations are, at best, marginally consistent. The results imply that l Car does not have significantly enhanced mass-loss rates like that measured for δ Cephei. We find that the mass of l Car is about 8-10 M ⊙. We present Hubble Space Telescope Cosmic Origins Spectrograph observations that also differ from measurements for δ Cep and β Dor. These measurements further add to the challenge of understanding the physics of Cepheids, but do hint at the possible relation between enhanced mass-loss and ultraviolet emission, perhaps both due to the strength of shocks propagating in the atmospheres of Cepheids. Based on observations made 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 NAS 5-26555. These observations are associated with program #13019. This work is also based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and the USA (NASA), associated with program #060374.

Origins, Structure, and Evolution of Magnetic Activity in the Cool Half of the H--R Diagram: an HST STIS Survey

NASA Astrophysics Data System (ADS)

Ayres, T. R.; Brown, A.; Drake, S. A.; Dupree, A. K.; Guedel, M.; Guinan, E.; Harper, G. M.; Jordan, C.; Linsky, J. L.; Reimers, D.; Schmitt, J. H. M. M.; Simon, T.

1999-12-01

In HST's cycle 8, we are carrying out a major ultraviolet spectral survey of late-type stars using the powerful capabilities of the Space Telescope Imaging Spectrograph (STIS). The origin of the hot UV emissions of otherwise cool stars is a fundamental puzzle in astrophysics. Magnetic phenomena---at the heart of chromospheric and coronal activity, and perhaps wind driving as well---play a central role in many cosmic settings. Our objective is to obtain high-quality ultraviolet spectra of a diverse collection of F--K stars, of all luminosity classes. Such a major project was unthinkable before STIS, but now is practical given the high resolution, broad spectral coverage, and sensitivity of the second generation spectrograph. Here, we discuss our choice of the thirteen targets; the observing strategy (which captures the entire UV spectrum between 1150--3000 Angstroms at resolutions λ /δ λ 30--100*E3 with good S/N); and preliminary results for the several targets observed to date (ζ Dor, F7 V, 1 May 1999, 2 CVZ orbits; V711 Tau, K1 IV+G5 IV, 15 September 1999, 5 orbits; β Cam, G0 I, 19 September 1999, 4 CVZ orbits). The observation of V711 Tau (HR 1099) was carried out during a long transmission grating pointing by the Chandra X-ray Observatory, in support of its ``Emission Line Project.'' This work was supported by grant GO-08280.01-97A from STScI. Observations were from the NASA/ESA HST, collected at the STScI, operated by AURA, under contract NAS5-26555.

Remotely Operated Aircraft (ROA) Impact on the National Airspace System (NAS) Work Package: Automation Impacts of ROA's in the NAS

NASA Technical Reports Server (NTRS)

2005-01-01

The purpose of this document is to analyze the impact of Remotely Operated Aircraft (ROA) operations on current and planned Air Traffic Control (ATC) automation systems in the En Route, Terminal, and Traffic Flow Management domains. The operational aspects of ROA flight, while similar, are not entirely identical to their manned counterparts and may not have been considered within the time-horizons of the automation tools. This analysis was performed to determine if flight characteristics of ROAs would be compatible with current and future NAS automation tools. Improvements to existing systems / processes are recommended that would give Air Traffic Controllers an indication that a particular aircraft is an ROA and modifications to IFR flight plan processing algorithms and / or designation of airspace where an ROA will be operating for long periods of time.

Air Traffic Controller Performance and Acceptability of Multiple UAS in a Simulated NAS Environment

NASA Technical Reports Server (NTRS)

Vu, Kim-Phuong L.; Strybel, Thomas; Chiappe, Dan; Morales, Greg; Battiste, Vernol; Shively, Robert Jay

2014-01-01

Previously, we showed that air traffic controllers (ATCos) rated UAS pilot verbal response latencies as acceptable when a 1.5 s delay was added to the UAS pilot responses, but a 5 s delay was rated as mostly unacceptable. In the present study we determined whether a 1.5 s added delay in the UAS pilots' verbal communications would affect ATCos interactions with UAS and other conventional aircraft when the number and speed of the UAS were manipulated. Eight radar-certified ATCos participated in this simulation. The ATCos managed a medium altitude sector containing arrival aircraft, en route aircraft, and one to four UAS. The UAS were conducting a surveillance mission and flew at either a "slow" or "fast" speed. We measured both UAS and conventional pilots' verbal communication latencies, and obtained ATCos' acceptability ratings for these latencies. Although the UAS pilot response latencies were longer than those of conventional pilots, the ATCos rated UAS pilot verbal communication latencies to be as acceptable as those of conventional pilots. Because the overall traffic load within the sector was held constant, ATCos only performed slightly worse when multiple UAS were in their sector compared to when only one UAS was in the sector. Implications of these findings for UAS integration in the NAS are discussed.

A Programming Model Performance Study Using the NAS Parallel Benchmarks

DOE PAGES

Shan, Hongzhang; Blagojević, Filip; Min, Seung-Jai; ...

2010-01-01

Harnessing the power of multicore platforms is challenging due to the additional levels of parallelism present. In this paper we use the NAS Parallel Benchmarks to study three programming models, MPI, OpenMP and PGAS to understand their performance and memory usage characteristics on current multicore architectures. To understand these characteristics we use the Integrated Performance Monitoring tool and other ways to measure communication versus computation time, as well as the fraction of the run time spent in OpenMP. The benchmarks are run on two different Cray XT5 systems and an Infiniband cluster. Our results show that in general the threemore » programming models exhibit very similar performance characteristics. In a few cases, OpenMP is significantly faster because it explicitly avoids communication. For these particular cases, we were able to re-write the UPC versions and achieve equal performance to OpenMP. Using OpenMP was also the most advantageous in terms of memory usage. Also we compare performance differences between the two Cray systems, which have quad-core and hex-core processors. We show that at scale the performance is almost always slower on the hex-core system because of increased contention for network resources.« less

UAS Integration into the NAS: Unmanned Aircraft System (UAS) Delegation of Separation

NASA Technical Reports Server (NTRS)

Fern, Lisa Carolynn; Kenny, Caitlin Ailis

2012-01-01

FAA Modernization and Reform Act of 2012 mandates UAS integration in the NAS by 2015. Operators must be able to safely maneuver UAS to maintain separation and collision avoidance. Delegated Separation is defined as the transfer of responsibility for maintaining separation between aircraft or vehicles from the air navigation service provider to the relevant flight operator, and will likely begin in sparsely trafficked areas before moving to more heavily populated airspace. As UAS operate primarily in areas with lower traffic density and perform maneuvers routinely that are currently managed through special handling, they have the advantage of becoming an early adopter of delegated separation. This experiment will examine if UAS are capable of performing delegated separation in 5 nm horizontal and 1000 ft vertical distances under two delegation conditions. In Extended Delegation, ATC are in charge of identifying problems and delegating to pilot identification and implementation of the solution and monitoring. In Full Delegation, the pilots are responsible for all tasks related to separation assurance: identification of problems and solutions, implementation and monitoring.

Modernizing Pickles - A Tool for Planning and Scheduling HST Astrometry

NASA Astrophysics Data System (ADS)

Juarez, Aaron; McArthur, B.; Benedict, G. F.

2007-12-01

Pickles is a Macintosh program written in C that was developed as a tool for determining pointings and rolls of the Hubble Space Telescope (HST) to place targets and astrometric reference stars in the Fine Guidance Sensor (FGS) field of regard ("pickles"). The program was developed in the late 1980s and runs under the "Classic” System. Ongoing HST astrometry projects require that this code be ported to the Intel-Mac OSX, because the Classic System is now unsupported. Pickles is a vital part of HST astrometry research. It graphically aids the investigator to determine where, when, and how the HST/FGS combination can observe an object and associated astrometric reference stars. Presently, Pickles can extract and display star positions from Guide Star Catalogs, such as the ACRS, SAO, and AGK3 catalogs via CD-ROMs. Future improvements will provide access to these catalogs and others through the internet. As an example of the past utility of Pickles, we highlight the recent determination of parallaxes for ten galactic Cepheids to determine an improved solar-metallicity Period-Luminosity relation. Support for this work was provided by NASA through grants GO-10989, -11210, and -11211 from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Work Package 5: Contingency Management. Mission Planning Requirements Document: Preliminary Version. Revision A

NASA Technical Reports Server (NTRS)

2005-01-01

The purpose of this document is to identify the general flight/mission planning requirements for same-day file-and-fly access to the NAS for both civil and military High-Altitude Long Endurance (HALE) Unmanned Aircraft System (UAS). Currently the scope of this document is limited to Step 1, operations above flight level 43,000 feet (FL430). This document describes the current applicable mission planning requirements and procedures for both manned and unmanned aircraft and addresses HALE UAS flight planning considerations in the future National Airspace System (NAS). It also discusses the unique performance and operational capabilities of HALE UAS associated with the Access 5 Project, presents some of the projected performance characteristics and conceptual missions for future systems, and provides detailed analysis of the recommended mission planning elements for operating HALE UAS in the NAS.

NASA's UAS Integration into the NAS: A Report on the Human Systems Integration Phase 1 Simulation Activities

NASA Technical Reports Server (NTRS)

Fern, Lisa; Rorie, R. Conrad; Shively, R. Jay

2014-01-01

In 2011 the National Aeronautics and Space Administration (NASA) began a five-year Project to address the technical barriers related to routine access of Unmanned Aerial Systems (UAS) in the National Airspace System (NAS). Planned in two phases, the goal of the first phase was to lay the foundations for the Project by identifying those barriers and key issues to be addressed to achieve integration. Phase 1 activities were completed two years into the five-year Project. The purpose of this paper is to review activities within the Human Systems Integration (HSI) subproject in Phase 1 toward its two objectives: 1) develop GCS guidelines for routine UAS access to the NAS, and 2) develop a prototype display suite within an existing Ground Control Station (GCS). The first objective directly addresses a critical barrier for UAS integration into the NAS - a lack of GCS design standards or requirements. First, the paper describes the initial development of a prototype GCS display suite and supporting simulation software capabilities. Then, three simulation experiments utilizing this simulation architecture are summarized. The first experiment sought to determine a baseline performance of UAS pilots operating in civil airspace under current instrument flight rules for manned aircraft. The second experiment examined the effect of currently employed UAS contingency procedures on Air Traffic Control (ATC) participants. The third experiment compared three GCS command and control interfaces on UAS pilot response times in compliance with ATC clearances. The authors discuss how the results of these and future simulation and flight-testing activities contribute to the development of GCS guidelines to support the safe integration of UAS into the NAS. Finally, the planned activities for Phase 2, including an integrated human-in-the-loop simulation and two flight tests are briefly described.

Physical Properties of Spectroscopically Confirmed Galaxies at z >= 6. I. Basic Characteristics of the Rest-frame UV Continuum and Lyα Emission

NASA Astrophysics Data System (ADS)

Jiang, Linhua; Egami, Eiichi; Mechtley, Matthew; Fan, Xiaohui; Cohen, Seth H.; Windhorst, Rogier A.; Davé, Romeel; Finlator, Kristian; Kashikawa, Nobunari; Ouchi, Masami; Shimasaku, Kazuhiro

2013-08-01

We present deep Hubble Space Telescope near-IR and Spitzer mid-IR observations of a large sample of spectroscopically confirmed galaxies at z >= 6. The sample consists of 51 Lyα emitters (LAEs) at z ~= 5.7, 6.5, and 7.0, and 16 Lyman break galaxies (LBGs) at 5.9 <= z <= 6.5. The near-IR images were mostly obtained with WFC3 in the F125W and F160W bands, and the mid-IR images were obtained with IRAC in the 3.6 μm and 4.5 μm bands. Our galaxies also have deep optical imaging data from Subaru Suprime-Cam. We utilize the multi-band data and secure redshifts to derive their rest-frame UV properties. These galaxies have steep UV-continuum slopes roughly between β ~= -1.5 and -3.5, with an average value of β ~= -2.3, slightly steeper than the slopes of LBGs in previous studies. The slope shows little dependence on UV-continuum luminosity except for a few of the brightest galaxies. We find a statistically significant excess of galaxies with slopes around β ~= -3, suggesting the existence of very young stellar populations with extremely low metallicity and dust content. Our galaxies have moderately strong rest-frame Lyα equivalent width (EW) in a range of ~10 to ~200 Å. The star formation rates are also moderate, from a few to a few tens of solar masses per year. The LAEs and LBGs in this sample share many common properties, implying that LAEs represent a subset of LBGs with strong Lyα emission. Finally, the comparison of the UV luminosity functions between LAEs and LBGs suggests that there exists a substantial population of faint galaxies with weak Lyα emission (EW < 20 Å) that could be the dominant contribution to the total ionizing flux at z >= 6. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555. Based in part on observations made with the

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project

NASA Technical Reports Server (NTRS)

Griner, James H.

2013-01-01

NASA's UAS Integration in the NAS project, has partnered with Rockwell Collins to develop a concept Control and Non-Payload Communication system prototype radio, operating on recently allocated UAS frequency spectrum bands. The prototype radio will be used to validate initial proposed performance requirements for UAS control communications. This presentation will give an overview of the current status of the design, development, and flight test planning for this prototype radio.

Timescales of Disk Evolution and Planet Formation: HST, Adaptive Optics, and ISO Observations of Weak-Line and Post-T Tauri Stars

NASA Astrophysics Data System (ADS)

Brandner, Wolfgang; Zinnecker, Hans; Alcalá, Juan M.; Allard, France; Covino, Elvira; Frink, Sabine; Köhler, Rainer; Kunkel, Michael; Moneti, Andrea; Schweitzer, Andreas

2000-08-01

We present high spatial resolution HST and ground-based adaptive optics observations and high-sensitivity ISO (ISOCAM & ISOPHOT) observations of a sample of X-ray selected weak-line (WTTS) and post- (PTTS) T Tauri stars located in the nearby Chamaeleon T and Scorpius-Centaurus OB associations. HST/NICMOS and adaptive optics observations aimed at identifying substellar companions (young brown dwarfs) at separations >=30 AU from the primary stars. No such objects were found within 300 AU of any of the target stars, and a number of faint objects at larger separations can very likely be attributed to a population of field (background) stars. ISOCAM observations of 5 to 15 Myr old WTTSs and PTTSs in ScoCen reveal infrared excesses which are clearly above photospheric levels and which have a spectral index intermediate between that of younger (1 to 5 Myr) T Tauri stars in Chamaeleon and that of pure stellar photospheres. The difference in the spectral index of the older PTTSs in ScoCen compared with the younger classical and weak-line TTSs in Cha can be attributed to a deficiency of smaller size (0.1 to 1 μm) dust grains relative to larger size (~5 μm) dust grains in the disks of the PTTSs. The lack of small dust grains is either due to the environment (effect of nearby O stars and supernova explosions) or due to disk evolution. If the latter is the case, it would hint that circumstellar disks start to become dust depleted at an age between 5 to 15 Myr. Dust depletion is very likely related to the build-up of larger particles (ultimately rocks and planetesimals) and thus an indicator for the onset of the period of planet formation. 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 the NASA contract NAS 5-26555, observations at the European Southern Observatory, La Silla (ESO Prop ID 58.E-0169), and observations with

Three Ancient Halo Subgiants: Precise Parallaxes, Compositions, Ages, and Implications for Globular Clusters

NASA Astrophysics Data System (ADS)

VandenBerg, Don A.; Bond, Howard E.; Nelan, Edmund P.; Nissen, P. E.; Schaefer, Gail H.; Harmer, Dianne

2014-09-01

The most accurate ages for the oldest stars are those obtained for nearby halo subgiants because they depend almost entirely on just the measured parallaxes and absolute oxygen abundances. In this study, we have used the Fine Guidance Sensors on the Hubble Space Telescope to determine trigonometric parallaxes, with precisions of 2.1% or better, for the Population II subgiants HD 84937, HD 132475, and HD 140283. High quality spectra have been used to derive their surface abundances of O, Fe, Mg, Si, and Ca, which are assumed to be 0.1-0.15 dex less than their initial abundances due to the effects of diffusion. Comparisons of isochrones with the three subgiants on the (log T eff, MV ) diagram yielded ages of 12.08 ± 0.14, 12.56 ± 0.46, and 14.27 ± 0.38 Gyr for HD 84937, HD 132475, and HD 140283, in turn, where each error bar includes only the parallax uncertainty. The total uncertainty is estimated to be ~ ± 0.8 Gyr (larger in the case of the near-turnoff star HD 84937). Although the age of HD 140283 is greater than the age of the universe as inferred from the cosmic microwave background by ~0.4-0.5 Gyr, this discrepancy is at a level of <1σ. Nevertheless, the first Population II stars apparently formed very soon after the Big Bang. (Stellar models that neglect diffusive processes seem to be ruled out as they would predict that HD 140283 is ~1.5 Gyr older than the universe.) The field halo subgiants appear to be older than globular clusters of similar metallicities: if distances close to those implied by the RR Lyrae standard candle are assumed, M 92 and M 5 are younger than HD 140283 and HD 132475 by ~1.5 and ~1.0 Gyr, respectively. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained by the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Based in part on observations collected at the La Silla Paranal Observatory, ESO, Chile.

Enhancement of photoluminescence from GaInNAsSb quantum wells upon annealing: improvement of material quality and carrier collection by the quantum well.

PubMed

Baranowski, M; Kudrawiec, R; Latkowska, M; Syperek, M; Misiewicz, J; Sarmiento, T; Harris, J S

2013-02-13

In this study we apply time resolved photoluminescence and contactless electroreflectance to study the carrier collection efficiency of a GaInNAsSb/GaAs quantum well (QW). We show that the enhancement of photoluminescence from GaInNAsSb quantum wells annealed at different temperatures originates not only from (i) the improvement of the optical quality of the GaInNAsSb material (i.e., removal of point defects, which are the source of nonradiative recombination) but it is also affected by (ii) the improvement of carrier collection by the QW region. The total PL efficiency is the product of these two factors, for which the optimal annealing temperatures are found to be ~700 °C and ~760 °C, respectively, whereas the optimal annealing temperature for the integrated PL intensity is found to be between the two temperatures and equals ~720 °C. We connect the variation of the carrier collection efficiency with the modification of the band bending conditions in the investigated structure due to the Fermi level shift in the GaInNAsSb layer after annealing.

Hubble Space Telescope Proper Motion (HSTPROMO) Catalogs of Galactic Globular Clusters. IV. Kinematic Profiles and Average Masses of Blue Straggler Stars

NASA Astrophysics Data System (ADS)

Baldwin, A. T.; Watkins, L. L.; van der Marel, R. P.; Bianchini, P.; Bellini, A.; Anderson, J.

2016-08-01

We make use of the Hubble Space Telescope proper-motion catalogs derived by Bellini et al. to produce the first radial velocity dispersion profiles σ (R) for blue straggler stars (BSSs) in Galactic globular clusters (GCs), as well as the first dynamical estimates for the average mass of the entire BSS population. We show that BSSs typically have lower velocity dispersions than stars with mass equal to the main-sequence turnoff mass, as one would expect for a more massive population of stars. Since GCs are expected to experience some degree of energy equipartition, we use the relation σ \\propto {M}-η , where η is related to the degree of energy equipartition, along with our velocity dispersion profiles to estimate BSS masses. We estimate η as a function of cluster relaxation from recent Monte Carlo cluster simulations by Bianchini et al. and then derive an average mass ratio {M}{BSS}/{M}{MSTO}=1.50+/- 0.14 and an average mass {M}{BSS}=1.22+/- 0.12 M ⊙ from 598 BSSs across 19 GCs. The final error bars include any systematic errors that are random between different clusters, but not any potential biases inherent to our methodology. Our results are in good agreement with the average mass of {M}{BSS}=1.22+/- 0.06 M ⊙ for the 35 BSSs in Galactic GCs in the literature with properties that have allowed individual mass determination. Based on proprietary and archival observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

Star Formation at z = 2.481 in the Lensed Galaxy SDSS J1110+6459: Star Formation Down to 30 pc Scales

NASA Astrophysics Data System (ADS)

Johnson, Traci L.; Rigby, Jane R.; Sharon, Keren; Gladders, Michael D.; Florian, Michael; Bayliss, Matthew B.; Wuyts, Eva; Whitaker, Katherine E.; Livermore, Rachael; Murray, Katherine T.

2017-07-01

We present measurements of the surface density of star formation, the star-forming clump luminosity function, and the clump size distribution function, for the lensed galaxy SGAS J111020.0+645950.8 at a redshift of z = 2.481. The physical size scales that we probe, radii r = 30-50 pc, are considerably smaller scales than have yet been studied at these redshifts. The star formation surface density we find within these small clumps is consistent with surface densities measured previously for other lensed galaxies at similar redshift. Twenty-two percent of the rest-frame ultraviolet light in this lensed galaxy arises from small clumps, with r< 100 pc. Within the range of overlap, the clump luminosity function measured for this lensed galaxy is remarkably similar to those of z˜ 0 galaxies. In this galaxy, star-forming regions smaller than 100 pc—physical scales not usually resolved at these redshifts by current telescopes—are important locations of star formation in the distant universe. If this galaxy is representative, this may contradict the theoretical picture in which the critical size scale for star formation in the distant universe is of the order of 1 kpc. Instead, our results suggest that current telescopes have not yet resolved the critical size scales of star-forming activity in galaxies over most of cosmic time. Based on observations made 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 NAS 5-26555. These observations are associated with program #13003.

Constraining UV Continuum Slopes of Active Galactic Nuclei with CLOUDY Models of Broad-line Region Extreme-ultraviolet Emission Lines

NASA Astrophysics Data System (ADS)

Moloney, Joshua; Shull, J. Michael

2014-10-01

Understanding the composition and structure of the broad-line region (BLR) of active galactic nuclei (AGNs) is important for answering many outstanding questions in supermassive black hole evolution, galaxy evolution, and ionization of the intergalactic medium. We used single-epoch UV spectra from the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope to measure EUV emission-line fluxes from four individual AGNs with 0.49 <= z <= 0.64, two AGNs with 0.32 <= z <= 0.40, and a composite of 159 AGNs. With the CLOUDY photoionization code, we calculated emission-line fluxes from BLR clouds with a range of density, hydrogen ionizing flux, and incident continuum spectral indices. The photoionization grids were fit to the observations using single-component and locally optimally emitting cloud (LOC) models. The LOC models provide good fits to the measured fluxes, while the single-component models do not. The UV spectral indices preferred by our LOC models are consistent with those measured from COS spectra. EUV emission lines such as N IV λ765, O II λ833, and O III λ834 originate primarily from gas with electron temperatures between 37,000 K and 55,000 K. This gas is found in BLR clouds with high hydrogen densities (n H >= 1012 cm-3) and hydrogen ionizing photon fluxes (ΦH >= 1022 cm-2 s-1). Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS5-26555.

Magnesium Amplification: The Last Missing Piece in Integrated Light Studies

NASA Astrophysics Data System (ADS)

Worthey, Guy

2017-01-01

We have gauged the effects of altered C, N, O, Si, Na, and Fe, each element separately varied, on stellar evolutionary isochrones. Stellar temperatures, luminosities, and lifetimes in each evolutionary phase are affected. The effects have been gauged by using the MESA "star" routines with altered chemical mixtures for 0.06 < M < 3.0 assuming a gray atmosphere outer boundary condition. Due to numerical glitching, there is considerable difficulty in reducing the effects to easily summarized trends. We describe two polynomial based methods for extracting the trends in lifetime, L, and T as a function of stellar parameters and chemical composition. The temperature effects were carried through to integrated light models and then compared to galaxy observations."Magnesium amplification" is a hypothetical positive feedback where enhancement of (only) one element causes a slight cooling of the giant branch, increasing the line strength beyond the increase expected from increased numbers of absorbers. Our experiment shows that magnesium amplification is real, but that it mostly arises in dwarfs, not giants. Applied to elliptical galaxies, the literature enhancement of Mg is often quoted as [Mg/Fe] = 0.3, but with this effect properly included, for an abundance pattern approximating that of giant elliptical galaxies, that drops to [Mg/Fe] = 0.15. Similar, large recalibrations will apply to all of the most abundance heavy elements, significantly altering our perception of the giant elliptical abundance mixture.Support for program AR-13900.001A was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555

The Galactic O-Star Spectroscopic Survey. I. Classification System and Bright Northern Stars in the Blue-violet at R ~ 2500

NASA Astrophysics Data System (ADS)

Sota, A.; Maíz Apellániz, J.; Walborn, N. R.; Alfaro, E. J.; Barbá, R. H.; Morrell, N. I.; Gamen, R. C.; Arias, J. I.

2011-04-01

We present the first installment of a massive spectroscopic survey of Galactic O stars, based on new, high signal-to-noise ratio, R ~ 2500 digital observations from both hemispheres selected from the Galactic O-Star Catalog of Maíz Apellániz et al. and Sota et al. The spectral classification system is rediscussed and a new atlas is presented, which supersedes previous versions. Extensive sequences of exceptional objects are given, including types Ofc, ON/OC, Onfp, Of?p, Oe, and double-lined spectroscopic binaries. The remaining normal spectra bring this first sample to 184 stars, which is close to complete to B = 8 and north of δ = -20° and includes all of the northern objects in Maíz Apellániz et al. that are still classified as O stars. The systematic and random accuracies of these classifications are substantially higher than previously attainable, because of the quality, quantity, and homogeneity of the data and analysis procedures. These results will enhance subsequent investigations in Galactic astronomy and stellar astrophysics. In the future, we will publish the rest of the survey, beginning with a second paper that will include most of the southern stars in Maíz Apellániz et al. The spectroscopic data in this article were gathered with three facilities: the 1.5 m telescope at the Observatorio de Sierra Nevada (OSN), the 3.5 m telescope at Calar Alto Observatory (CAHA), and the du Pont 2.5 m telescope at Las Campanas Observatory (LCO). Some of the supporting imaging data were obtained with the 2.2 m telescope at CAHA and the NASA/ESA Hubble Space Telescope (HST). The rest were retrieved from the DSS2 and Two Micron All Sky Survey (2MASS) surveys. The HST data were obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

Cosmic Origins Spectrograph Observations of Warm Intervening Gas at z ~ 0.325 toward 3C 263

NASA Astrophysics Data System (ADS)

Narayanan, Anand; Savage, Blair D.; Wakker, Bart P.

2012-06-01

We present HST/COS high-S/N observations of the z = 0.32566 multiphase absorber toward 3C 263. The Cosmic Origins Spectrograph (COS) data show absorption from H I (Lyα to Lyθ), O VI, C III, N III, Si III, and C II. The Ne VIII in this absorber is detected in the FUSE spectrum along with O III, O IV, and N IV. The low and intermediate ions are kinematically aligned with each other and H I and display narrow line widths of b ~ 6-8 km s-1. The O VI λλ1031, 1037 lines are kinematically offset by Δv ~ 12 km s-1 from the low ions and are a factor of ~4 broader. All metal ions except O VI and Ne VIII are consistent with an origin in gas photoionized by the extragalactic background radiation. The bulk of the observed H I is also traced by this photoionized medium. The metallicity in this gas phase is Z >~ 0.15 Z ⊙ with carbon having near-solar abundances. The O VI and Ne VIII favor an origin in collisionally ionized gas at T = 5.2 × 105 K. The H I absorption associated with this warm absorber is a broad-Lyα absorber (BLA) marginally detected in the COS spectrum. This warm gas phase has a metallicity of [X/H] ~-0.12 dex, and a total hydrogen column density of N( H) ~ 3 × 1019 cm-2, which is ~2 dex higher than what is traced by the photoionized gas. Simultaneous detection of O VI, Ne VIII, and BLAs in an absorber can be a strong diagnostic of gas with T ~ 105-106 K corresponding to the warm phase of the warm-hot intergalactic medium or shock-heated gas in the extended halos of galaxies. 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 NAS 05-26555, and the NASA-CNES/ESA Far Ultraviolet Spectroscopic Explorer mission, operated by the Johns Hopkins University, supported by NASA contract NAS 05-32985.

The HDUV Survey: Six Lyman Continuum Emitter Candidates at z ˜ 2 Revealed by HST UV Imaging

NASA Astrophysics Data System (ADS)

Naidu, R. P.; Oesch, P. A.; Reddy, N.; Holden, B.; Steidel, C. C.; Montes, M.; Atek, H.; Bouwens, R. J.; Carollo, C. M.; Cibinel, A.; Illingworth, G. D.; Labbé, I.; Magee, D.; Morselli, L.; Nelson, E. J.; van Dokkum, P. G.; Wilkins, S.

2017-09-01

We present six galaxies at z˜ 2 that show evidence of Lyman continuum (LyC) emission based on the newly acquired UV imaging of the Hubble Deep UV legacy survey (HDUV) conducted with the WFC3/UVIS camera on the Hubble Space Telescope (HST). At the redshift of these sources, the HDUV F275W images partially probe the ionizing continuum. By exploiting the HST multiwavelength data available in the HDUV/GOODS fields, models of the UV spectral energy distributions, and detailed Monte Carlo simulations of the intergalactic medium absorption, we estimate the absolute ionizing photon escape fractions of these galaxies to be very high—typically > 60 % (> 13 % for all sources at 90% likelihood). Our findings are in broad agreement with previous studies that found only a small fraction of galaxies with high escape fraction. These six galaxies compose the largest sample yet of LyC leaking candidates at z˜ 2 whose inferred LyC flux has been observed at HST resolution. While three of our six candidates show evidence of hosting an active galactic nucleus, two of these are heavily obscured and their LyC emission appears to originate from star-forming regions rather than the central nucleus. Extensive multiwavelength data in the GOODS fields, especially the near-IR grism spectra from the 3D-HST survey, enable us to study the candidates in detail and tentatively test some recently proposed indirect methods to probe LyC leakage. High-resolution spectroscopic follow-up of our candidates will help constrain such indirect methods, which are our only hope of studying f esc at z˜ 5-9 in the JWST era. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

Characterizing the Circumgalactic Medium of Nearby Galaxies with HST/COS and HST/STIS Absorption-line Spectroscopy. II. Methods and Models

NASA Astrophysics Data System (ADS)

Keeney, Brian A.; Stocke, John T.; Danforth, Charles W.; Shull, J. Michael; Pratt, Cameron T.; Froning, Cynthia S.; Green, James C.; Penton, Steven V.; Savage, Blair D.

2017-05-01

We present basic data and modeling for a survey of the cool, photoionized circumgalactic medium (CGM) of low-redshift galaxies using far-UV QSO absorption-line probes. This survey consists of “targeted” and “serendipitous” CGM subsamples, originally described in Stocke et al. (Paper I). The targeted subsample probes low-luminosity, late-type galaxies at z< 0.02 with small impact parameters (< ρ > =71 kpc), and the serendipitous subsample probes higher luminosity galaxies at z≲ 0.2 with larger impact parameters (< ρ > =222 kpc). Hubble Space Telescope and FUSE UV spectroscopy of the absorbers and basic data for the associated galaxies, derived from ground-based imaging and spectroscopy, are presented. We find broad agreement with the COS-Halos results, but our sample shows no evidence for changing ionization parameter or hydrogen density with distance from the CGM host galaxy, probably because the COS-Halos survey probes the CGM at smaller impact parameters. We find at least two passive galaxies with H I and metal-line absorption, confirming the intriguing COS-Halos result that galaxies sometimes have cool gas halos despite no on-going star formation. Using a new methodology for fitting H I absorption complexes, we confirm the CGM cool gas mass of Paper I, but this value is significantly smaller than that found by the COS-Halos survey. We trace much of this difference to the specific values of the low-z metagalactic ionization rate assumed. After accounting for this difference, a best-value for the CGM cool gas mass is found by combining the results of both surveys to obtain {log}(M/{M}⊙ )=10.5+/- 0.3, or ˜30% of the total baryon reservoir of an L≥slant {L}* , star-forming galaxy. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

The OpenMP Implementation of NAS Parallel Benchmarks and its Performance

NASA Technical Reports Server (NTRS)

Jin, Hao-Qiang; Frumkin, Michael; Yan, Jerry

1999-01-01

As the new ccNUMA architecture became popular in recent years, parallel programming with compiler directives on these machines has evolved to accommodate new needs. In this study, we examine the effectiveness of OpenMP directives for parallelizing the NAS Parallel Benchmarks. Implementation details will be discussed and performance will be compared with the MPI implementation. We have demonstrated that OpenMP can achieve very good results for parallelization on a shared memory system, but effective use of memory and cache is very important.

The Relationship between the Dense Neutral and Diffuse Ionized Gas in the Thick Disks of Two Edge-on Spiral Galaxies

NASA Astrophysics Data System (ADS)

Rueff, Katherine M.; Howk, J. Christopher; Pitterle, Marissa; Hirschauer, Alec S.; Fox, Andrew J.; Savage, Blair D.

2013-03-01

We present high-resolution, optical images (BVI + Hα) of the multiphase interstellar medium (ISM) in the thick disks of the edge-on spiral galaxies NGC 4013 and NGC 4302. Our images from the Hubble Space Telescope (HST), Large Binocular Telescope, and WIYN 3.5 m telescope reveal an extensive population of filamentary dust absorption seen to z ~2-2.5 kpc. Many of these dusty thick disk structures have characteristics reminiscent of molecular clouds found in the Milky Way disk. Our Hα images show that the extraplanar diffuse ionized gas (DIG) in these galaxies is dominated by a smooth, diffuse component. The strongly filamentary morphologies of the dust absorption have no counterpart in the smoothly distributed Hα emission. We argue that the thick disk DIG and dust-bearing filaments trace physically distinct phases of the thick disk ISM, the latter tracing a dense, warm or cold neutral medium. The dense, dusty matter in the thick disks of spiral galaxies is largely tracing matter ejected from the thin disk via energetic feedback from massive stars. The high densities of the gas may be a result of converging gas flows. This dense material fuels some thick disk star formation, as evidenced by the presence of thick disk H II regions. Based on observations obtained with the NASA/ESA Hubble Space Telescope operated at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Also, based on data acquired using the Large Binocular Telescope (LBT). The LBT is an international collaboration among institutions in the US, Italy, and Germany. LBT Corporation partners are the University of Arizona, on behalf of the Arizona University System; Instituto Nazionale do Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max Planck Society, the Astrophysical Institute of Potsdam, and Heidelberg University; Ohio State University, and the Research Corporation, on

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project: KDP-A for Phase 2 Minimum Operational Performance Standards

NASA Technical Reports Server (NTRS)

Grindle, Laurie; Hackenberg, Davis L.

2016-01-01

UAS Integration in the NAS Project has: a) Developed Technical Challenges that are crucial to UAS integration, aligned with NASA's Strategic Plan and Thrusts, and support FAA standards development. b) Demonstrated rigorous project management processes through the execution of previous phases. c) Defined Partnership Plans. d) Established path to KDP-C. Request approval of Technical Challenges, execution of partnerships and plans, and execution of near-term FY17 activities. There is an increasing need to fly UAS in the NAS to perform missions of vital importance to National Security and Defense, Emergency Management, and Science. There is also an emerging need to enable commercial applications such as cargo transport (e.g. FedEx). Unencumbered NAS Access for Civil/Commercial UAS. Provide research findings, utilizing simulation and flight tests, to support the development and validation of DAA and C2 technologies necessary for integrating Unmanned Aircraft Systems into the National Airspace System.

NAS (Numerical Aerodynamic Simulation Program) technical summaries, March 1989 - February 1990

NASA Technical Reports Server (NTRS)

1990-01-01

Given here are selected scientific results from the Numerical Aerodynamic Simulation (NAS) Program's third year of operation. During this year, the scientific community was given access to a Cray-2 and a Cray Y-MP supercomputer. Topics covered include flow field analysis of fighter wing configurations, large-scale ocean modeling, the Space Shuttle flow field, advanced computational fluid dynamics (CFD) codes for rotary-wing airloads and performance prediction, turbulence modeling of separated flows, airloads and acoustics of rotorcraft, vortex-induced nonlinearities on submarines, and standing oblique detonation waves.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project

NASA Technical Reports Server (NTRS)

Fern, Lisa

2017-01-01

This presentation summarizes the simulation work conducted by the Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project. It focuses on the contribution of that research to the development of RTCA Special Committee 228's (SC-228) Minimum Operational Performance Standards (MOPS) for UAS. The research objectives and primary findings from four different human-in-the-loop simulations are discussed, along with the specific requirements these studies led to in the final MOPS document.

[Inventive activity of the Department of Metabolism Regulation of the Palladin Institute of Biochemistry of NAS of Ukraine].

PubMed

Danilova, V M; Vynogradova, R P; Chernysh, I G; Petrenko, T M

2016-01-01

The article is devoted to the inventive activity of the Department of Metabolism Regulation of the Palladin Institute of Biochemistry of NAS of Ukraine in the context of the history of its inception, development and the research activities of its founder, academician of NAS of Ukraine M. F. Guly as well as his students and followers. It briefly tells about practical achievements of M. F. Guly which were as significant, immense and diverse as his scientific accomplishments. The paper analyses in detail the practical results of scientific research of his students and followers aimed to solve practical problems of medicine, food-processing, agriculture, and which are essentially a continuation of the ideas and projects of M. F. Guly.

The Luminosity Function of Star Clusters in 20 Star-forming Galaxies Based on Hubble Legacy Archive Photometry

NASA Astrophysics Data System (ADS)

Whitmore, Bradley C.; Chandar, Rupali; Bowers, Ariel S.; Larsen, Soeren; Lindsay, Kevin; Ansari, Asna; Evans, Jessica

2014-04-01

brighter than MI = -9 (log N). We also examine the magnitude of the brightest cluster versus log SFR for a sample including both dwarf galaxies and ULIRGs. This shows that the correlation extends over roughly six orders of magnitude but with scatter that is larger than for our spiral sample, probably because of the high levels of extinction in many of the LIRGs. 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. Also based on data obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESA), and the Canadian Astronomy Data Centre (CADC/NRC/CSA). Support for Program number 11781 was provided by NASA through a grant from the Space Telescope Science Institute.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project FY16 Annual Review

NASA Technical Reports Server (NTRS)

Grindle, Laurie; Hackenberg, Davis

2016-01-01

This presentation gives insight into the research activities and efforts being executed in order to integrate unmanned aircraft systems into the national airspace system. This briefing is to inform others of the UAS-NAS FY16 progress and future directions.

Amorphous MoS3 as the sulfur-equivalent cathode material for room-temperature Li-S and Na-S batteries.

PubMed

Ye, Hualin; Ma, Lu; Zhou, Yu; Wang, Lu; Han, Na; Zhao, Feipeng; Deng, Jun; Wu, Tianpin; Li, Yanguang; Lu, Jun

2017-12-12

Many problems associated with Li-S and Na-S batteries essentially root in the generation of their soluble polysulfide intermediates. While conventional wisdom mainly focuses on trapping polysulfides at the cathode using various functional materials, few strategies are available at present to fully resolve or circumvent this long-standing issue. In this study, we propose the concept of sulfur-equivalent cathode materials, and demonstrate the great potential of amorphous MoS 3 as such a material for room-temperature Li-S and Na-S batteries. In Li-S batteries, MoS 3 exhibits sulfur-like behavior with large reversible specific capacity, excellent cycle life, and the possibility to achieve high areal capacity. Most remarkably, it is also fully cyclable in the carbonate electrolyte under a relatively high temperature of 55 °C. MoS 3 can also be used as the cathode material of even more challenging Na-S batteries to enable decent capacity and good cycle life. Operando X-ray absorption spectroscopy (XAS) experiments are carried out to track the structural evolution of MoS 3 It largely preserves its chain-like structure during repetitive battery cycling without generating any free polysulfide intermediates.

Identification of nitrogen- and host-related deep-level traps in n-type GaNAs and their evolution upon annealing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gelczuk, Ł., E-mail: lukasz.gelczuk@pwr.edu.pl; Kudrawiec, R., E-mail: robert.kudrawiec@pwr.edu.pl; Henini, M.

2014-07-07

Deep level traps in as-grown and annealed n-GaNAs layers (doped with Si) of various nitrogen concentrations (N=0.2%, 0.4%, 0.8%, and 1.2%) were investigated by deep level transient spectroscopy. In addition, optical properties of GaNAs layers were studied by photoluminescence and contactless electroreflectance. The identification of N- and host-related traps has been performed on the basis of band gap diagram [Kudrawiec, Appl. Phys. Lett. 101, 082109 (2012)], which assumes that the activation energy of electron traps of the same microscopic nature decreases with the rise of nitrogen concentration in accordance with the N-related shift of the conduction band towards trap levels.more » The application of this diagram has allowed to investigate the evolution of donor traps in GaNAs upon annealing. In general, it was observed that the concentration of N- and host-related traps decreases after annealing and PL improves very significantly. However, it was also observed that some traps are generated due to annealing. It explains why the annealing conditions have to be carefully optimized for this material system.« less

Comprehensive Phylogenetic Analysis of Bovine Non-aureus Staphylococci Species Based on Whole-Genome Sequencing

PubMed Central

Naushad, Sohail; Barkema, Herman W.; Luby, Christopher; Condas, Larissa A. Z.; Nobrega, Diego B.; Carson, Domonique A.; De Buck, Jeroen

2016-01-01

Non-aureus staphylococci (NAS), a heterogeneous group of a large number of species and subspecies, are the most frequently isolated pathogens from intramammary infections in dairy cattle. Phylogenetic relationships among bovine NAS species are controversial and have mostly been determined based on single-gene trees. Herein, we analyzed phylogeny of bovine NAS species using whole-genome sequencing (WGS) of 441 distinct isolates. In addition, evolutionary relationships among bovine NAS were estimated from multilocus data of 16S rRNA, hsp60, rpoB, sodA, and tuf genes and sequences from these and numerous other single genes/proteins. All phylogenies were created with FastTree, Maximum-Likelihood, Maximum-Parsimony, and Neighbor-Joining methods. Regardless of methodology, WGS-trees clearly separated bovine NAS species into five monophyletic coherent clades. Furthermore, there were consistent interspecies relationships within clades in all WGS phylogenetic reconstructions. Except for the Maximum-Parsimony tree, multilocus data analysis similarly produced five clades. There were large variations in determining clades and interspecies relationships in single gene/protein trees, under different methods of tree constructions, highlighting limitations of using single genes for determining bovine NAS phylogeny. However, based on WGS data, we established a robust phylogeny of bovine NAS species, unaffected by method or model of evolutionary reconstructions. Therefore, it is now possible to determine associations between phylogeny and many biological traits, such as virulence, antimicrobial resistance, environmental niche, geographical distribution, and host specificity. PMID:28066335

12 CFR 327.5 - Assessment base.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Banking FEDERAL DEPOSIT INSURANCE CORPORATION REGULATIONS AND STATEMENTS OF GENERAL POLICY ASSESSMENTS In General § 327.5 Assessment base. (a) Quarter-end balances and average daily balances. An insured depository institution shall determine its assessment base using quarter-end balances until changes in the...

Effects of growth rate on structural property and adatom migration behaviors for growth of GaInNAs/GaAs (001) by molecular beam epitaxy

NASA Astrophysics Data System (ADS)

Li, Jingling; Gao, Peng; Zhang, Shuguang; Wen, Lei; Gao, Fangliang; Li, Guoqiang

2018-03-01

We have investigated the structural properties and the growth mode of GaInNAs films prepared at different growth rates (Rg) by molecular beam epitaxy. The crystalline structure is studied by high resolution X-ray diffraction, and the evolution of GaInNAs film surface morphologies is studied by atomic force microscopy. It is found that both the crystallinity and the surface roughness are improved by increasing Rg, and the change in the growth mode is attributed to the adatom migration behaviors particularly for In atoms, which is verified by elemental analysis. In addition, we have presented some theoretical calculation results related to the N adsorption energy to show the unique N migration behavior, which is instructive to interpret the growth mechanism of GaInNAs films.

Close Companions to Two High-redshift Quasars

NASA Astrophysics Data System (ADS)

McGreer, Ian D.; Fan, Xiaohui; Strauss, Michael A.; Haiman, Zoltàn; Richards, Gordon T.; Jiang, Linhua; Bian, Fuyan; Schneider, Donald P.

2014-10-01

We report the serendipitous discoveries of companion galaxies to two high-redshift quasars. SDSS J025617.7+001904 is a z = 4.79 quasar included in our recent survey of faint quasars in the SDSS Stripe 82 region. The initial MMT slit spectroscopy shows excess Lyα emission extending well beyond the quasar's light profile. Further imaging and spectroscopy with LBT/MODS1 confirms the presence of a bright galaxy (i AB = 23.6) located 2'' (12 kpc projected) from the quasar with strong Lyα emission (EW0 ≈ 100 Å) at the redshift of the quasar, as well as faint continuum. The second quasar, CFHQS J005006.6+344522 (z = 6.25), is included in our recent HST SNAP survey of z ~ 6 quasars searching for evidence of gravitational lensing. Deep imaging with ACS and WFC3 confirms an optical dropout ~4.5 mag fainter than the quasar (Y AB = 25) at a separation of 0.''9. The red i 775 - Y 105 color of the galaxy and its proximity to the quasar (5 kpc projected if at the quasar redshift) strongly favor an association with the quasar. Although it is much fainter than the quasar, it is remarkably bright when compared to field galaxies at this redshift, while showing no evidence for lensing. Both systems may represent late-stage mergers of two massive galaxies, with the observed light for one dominated by powerful ongoing star formation and for the other by rapid black hole growth. Observations of close companions are rare; if major mergers are primarily responsible for high-redshift quasar fueling then the phase when progenitor galaxies can be observed as bright companions is relatively short. Based in part on observations made 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 NAS 5-26555. These observations are associated with programs #12184 and #12493. Observations were also made with the LBT and MMT.

The Low End of the Initial Mass Function in Young Clusters. II. Evidence for Primordial Mass Segregation in NGC 330 in the Small Magellanic Cloud

NASA Astrophysics Data System (ADS)

Sirianni, Marco; Nota, Antonella; De Marchi, Guido; Leitherer, Claus; Clampin, Mark

2002-11-01

As part of a larger program aimed at investigating the universality of the initial mass function (IMF) at low masses in a number of young clusters in the LMC and SMC, we present a new study of the low end of the stellar IMF of NGC 330, the richest young star cluster in the SMC, from deep broadband V and I images obtained with HST/WFPC2. We detect stars down to a limiting magnitude of m555=24.9, which corresponds to stellar masses of ~0.8Msolar at the distance of the SMC. A comparison of the cluster color-magnitude diagram with theoretical evolutionary tracks indicates an age of ~30 Myr for NGC 330, in agreement with previous published results. We derive the cluster luminosity function, which we correct for background contamination using an adjacent SMC field, and construct the mass function in the 1-7Msolar mass range. Given the young cluster age, the MF can well approximate the IMF. We find that the IMF in the central cluster regions (within 30") is well reproduced by a power law with a slope consistent with Salpeter's. In addition, the richness of the cluster allows us to investigate the IMF as a function of radial distance from the center. We find that the IMF becomes steeper at increasing distances from the cluster center (between 30" and 90"), with the number of massive stars (>5Msolar) decreasing from the core to the outskirts of the cluster 5 times more rapidly than the less-massive objects (~=1Msolar). We believe the observed mass segregation to be of a primordial nature rather than dynamical since the age of NGC 330 is 10 times shorter than the expected relaxation time of the cluster. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by AURA for NASA under contract NAS5-26555.

The Brightest Young Star Clusters in NGC 5253.

NASA Astrophysics Data System (ADS)

Calzetti, D.; Johnson, K. E.; Adamo, A.; Gallagher, J. S., III; Andrews, J. E.; Smith, L. J.; Clayton, G. C.; Lee, J. C.; Sabbi, E.; Ubeda, L.; Kim, H.; Ryon, J. E.; Thilker, D.; Bright, S. N.; Zackrisson, E.; Kennicutt, R. C.; de Mink, S. E.; Whitmore, B. C.; Aloisi, A.; Chandar, R.; Cignoni, M.; Cook, D.; Dale, D. A.; Elmegreen, B. G.; Elmegreen, D. M.; Evans, A. S.; Fumagalli, M.; Gouliermis, D. A.; Grasha, K.; Grebel, E. K.; Krumholz, M. R.; Walterbos, R.; Wofford, A.; Brown, T. M.; Christian, C.; Dobbs, C.; Herrero, A.; Kahre, L.; Messa, M.; Nair, P.; Nota, A.; Östlin, G.; Pellerin, A.; Sacchi, E.; Schaerer, D.; Tosi, M.

2015-10-01

The nearby dwarf starburst galaxy NGC 5253 hosts a number of young, massive star clusters, the two youngest of which are centrally concentrated and surrounded by thermal radio emission (the “radio nebula”). To investigate the role of these clusters in the starburst energetics, we combine new and archival Hubble Space Telescope images of NGC 5253 with wavelength coverage from 1500 Å to 1.9 μm in 13 filters. These include Hα, Pβ, and Pα, and the imaging from the Hubble Treasury Program LEGUS (Legacy Extragalactic UV Survey). The extraordinarily well-sampled spectral energy distributions enable modeling with unprecedented accuracy the ages, masses, and extinctions of the nine optically brightest clusters (MV < -8.8) and the two young radio nebula clusters. The clusters have ages ˜1-15 Myr and masses ˜1 × 104-2.5 × 105 M⊙. The clusters’ spatial location and ages indicate that star formation has become more concentrated toward the radio nebula over the last ˜15 Myr. The most massive cluster is in the radio nebula; with a mass ˜2.5 × 105 M⊙ and an age ˜1 Myr, it is 2-4 times less massive and younger than previously estimated. It is within a dust cloud with AV ˜ 50 mag, and shows a clear near-IR excess, likely from hot dust. The second radio nebula cluster is also ˜1 Myr old, confirming the extreme youth of the starburst region. These two clusters account for about half of the ionizing photon rate in the radio nebula, and will eventually supply about 2/3 of the mechanical energy in present-day shocks. Additional sources are required to supply the remaining ionizing radiation, and may include very massive stars. Based on observations obtained with the NASA/ESA Hubble Space Telescope, at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

UAS Integration Into the NAS: An Examination of Baseline Compliance in the Current Airspace System

NASA Technical Reports Server (NTRS)

Fern, Lisa; Kenny, Caitlin A.; Shively, Robert J.; Johnson, Walter

2012-01-01

As a result of the FAA Modernization and Reform Act of 2012, Unmanned Aerial Systems (UAS) are expected to be integrated into the National Airspace System (NAS) by 2015. Several human factors challenges need to be addressed before UAS can safely and routinely fly in the NAS with manned aircraft. Perhaps the most significant challenge is for the UAS to be non-disruptive to the air traffic management system. Another human factors challenge is how to provide UAS pilots with intuitive traffic information in order to support situation awareness (SA) of their airspace environment as well as a see-and-avoid capability comparable to manned aircraft so that a UAS pilot could safely maneuver the aircraft to maintain separation and collision avoidance if necessary. A simulation experiment was conducted to examine baseline compliance of UAS operations in the current airspace system. Researchers also examined the effects of introducing a Cockpit Situation Display (CSD) into a UAS Ground Control Station (GCS) on UAS pilot performance, workload and situation awareness while flying in a positively controlled sector. Pilots were tasked with conducting a highway patrol police mission with a Medium Altitude Long Endurance (MALE) UAS in L.A. Center airspace with two mission objectives: 1) to reroute the UAS when issued new instructions from their commander, and 2) to communicate with Air Traffic Control (ATC) to negotiate flight plan changes and respond to vectoring and altitude change instructions. Objective aircraft separation data, workload ratings, SA data, and subjective ratings regarding UAS operations in the NAS were collected. Results indicate that UAS pilots were able to comply appropriately with ATC instructions. In addition, the introduction of the CSD improved pilot SA and reduced workload associated with UAS and ATC interactions.

Managing nursing assistants with a web-based system: an empirical investigation of the mixed-staff strategy.

PubMed

Lin, I-Chun; Hou, Ying-Hui; Huang, Hui-Ling; Chu, Tsui-Ping; Chang, Ray-E

2010-06-01

Under the global shortage of Registered Nurses (RNs), some hospitals have integrated nursing assistants (NAs) into their teams to help to provide maximum quality care for acute patients, while keeping the hospital's staff-related costs down. However, the RNs may have to shoulder an increased burden of assigning and overseeing NAs. A web-based Nursing Assistants Management System (NAMS) was developed and evaluated for a case hospital in Taiwan to compare the processes of assigning and managing NAs before and after the NAMS intervention. The results showed that NAMS saved 80% of the time needed for manual operation and there were no more complains about NAs being slow in dealing with patients after the system intervention. The satisfaction levels of all NA managers and RNs were acceptable. Based on the research findings, the implication and limitations of this study were discussed.

Redshift and blueshift of GaNAs/GaAs multiple quantum wells induced by rapid thermal annealing

NASA Astrophysics Data System (ADS)

Sun, Yijun; Cheng, Zhiyuan; Zhou, Qiang; Sun, Ying; Sun, Jiabao; Liu, Yanhua; Wang, Meifang; Cao, Zhen; Ye, Zhi; Xu, Mingsheng; Ding, Yong; Chen, Peng; Heuken, Michael; Egawa, Takashi

2018-02-01

The effects of rapid thermal annealing (RTA) on the optical properties of GaNAs/GaAs multiple quantum wells (MQWs) grown by chemical beam epitaxy (CBE) are studied by photoluminescence (PL) at 77 K. The results show that the optical quality of the MQWs improves significantly after RTA. With increasing RTA temperature, PL peak energy of the MQWs redshifts below 1023 K, while it blueshifts above 1023 K. Two competitive processes which occur simultaneously during RTA result in redshift at low temperature and blueshift at high temperature. It is also found that PL peak energy shift can be explained neither by nitrogen diffusion out of quantum wells nor by nitrogen reorganization inside quantum wells. PL peak energy shift can be quantitatively explained by a modified recombination coupling model in which redshift nonradiative recombination and blueshift nonradiative recombination coexist. The results obtained have significant implication on the growth and RTA of GaNAs material for high performance optoelectronic device application.

Spectroscopy and Photometry of Multiple Populations along the Asymptotic Giant Branch of NGC 2808 and NGC 6121 (M4)

NASA Astrophysics Data System (ADS)

Marino, A. F.; Milone, A. P.; Yong, D.; Da Costa, G.; Asplund, M.; Bedin, L. R.; Jerjen, H.; Nardiello, D.; Piotto, G.; Renzini, A.; Shetrone, M.

2017-07-01

We present a photometric and spectroscopic study of multiple populations along the asymptotic giant branch (AGB) of the intermediate-metallicity globular clusters (GCs) NGC 2808 and NGC 6121 (M4). Chemical abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Fe, Co, Ni, Zn, Y, and Ce in AGB stars from high-resolution FLAMES+UVES@VLT spectra are reported for both clusters. Our spectroscopic results have been combined with multiwavelength photometry from the Hubble Space Telescope UV survey of Galactic GCs and ground-based photometry, as well as proper motions derived by combining stellar positions from ground-based images and Gaia DR1. Our analysis reveals that the AGBs of both clusters host multiple populations with different chemical compositions. In M4, we have identified two main populations of stars with different Na/O content lying on distinct AGBs in the {m}{{F}438{{W}}} versus {C}{{F}275{{W}},{{F}}336{{W}},{{F}}438{{W}}} and the V versus {C}{{U},{{B}},{{I}}} pseudo-color-magnitude diagrams. In the more massive and complex GC NGC 2808, three groups of stars with different chemical abundances occupy different locations on the so-called “chromosome map” photometric diagram constructed for AGB stars. The spectroscopic + photometric comparison of stellar populations along the AGB and the red giants of this GC suggests that the AGB hosts stellar populations with a range in helium abundances from primordial to high contents of Y˜ 0.32. By contrast, from our data set, there is no evidence for stars with extreme helium abundance (Y˜ 0.38) on the AGB, suggesting that the most He-rich stars of NGC 2808 do not reach this phase. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programs 093.D-0789 and 094.D-0455 and on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

Simultaneous Ultraviolet and X-Ray Spectroscopy of the Seyfert 1 Galaxy NGC 5548. I. Physical Conditions in the Ultraviolet Absorbers

NASA Astrophysics Data System (ADS)

Crenshaw, D. M.; Kraemer, S. B.; Gabel, J. R.; Kaastra, J. S.; Steenbrugge, K. C.; Brinkman, A. C.; Dunn, J. P.; George, I. M.; Liedahl, D. A.; Paerels, F. B. S.; Turner, T. J.; Yaqoob, T.

2003-09-01

We present new UV spectra of the nucleus of the Seyfert 1 galaxy NGC 5548, which we obtained with the Space Telescope Imaging Spectrograph at high spectral resolution, in conjunction with simultaneous Chandra X-Ray Observatory spectra. Taking advantage of the low UV continuum and broad emission-line fluxes, we have determined that the deepest UV absorption component covers at least a portion of the inner, high-ionization narrow-line region (NLR). We find nonunity covering factors in the cores of several kinematic components, which increase the column density measurements of N V and C IV by factors of 1.2-1.9 over the full-covering case; however, the revised columns have only a minor effect on the parameters derived from our photoionization models. For the first time, we have simultaneous N V and C IV columns for component 1 (at -1040 km s-1) and find that this component cannot be an X-ray warm absorber, contrary to our previous claim based on nonsimultaneous observations. We find that models of the absorbers based on solar abundances severely overpredict the O VI columns previously obtained with the Far Ultraviolet Spectroscopic Explorer and present arguments that this is not likely due to variability. However, models that include either enhanced nitrogen (twice solar) or dust, with strong depletion of carbon in either case, are successful in matching all of the observed ionic columns. These models result in substantially lower ionization parameters and total column densities compared to dust-free solar-abundance models and produce little O VII or O VIII, indicating that none of the UV absorbers are X-ray warm absorbers. Based on observations made 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. These observations are associated with proposal 9279.

HST FGS1R Results On the Association Between Binary Wolf-Rayet Stars and Non-Thermal Radio Emission

NASA Astrophysics Data System (ADS)

Wallace, D. J.; Gies, D. R.; Nelan, E.; Leitherer, C.

2000-12-01

Two separate models have been proposed to explain the non-thermal emission detected in some Wolf-Rayet (WR) stars. In models based on single WR stars, this emission is proposed to arise via synchrotron radiative processes in the outer (intrinsically unstable) WR wind (e.g. White & Chen 1995). In models based on WR + O systems, this non-thermal radio emission is suggested to arise from the WR wind colliding with the wind of a companion (e.g. Williams et al. 1990). In order to be observed, the colliding winds region is believed to occur in wide binaries where the interaction zone is outside the WR radio photosphere (≈30 AU based on spherically symmetric uniform wind models). HST FGS1R observations of 9 non-thermal and 9, as a control group, purely thermal radio emitting stars attempted to verify the theory that this non-thermal emission is always a result of binary interactions. If the binary model is correct, then most or all of our non-thermal targets should have companions with projected separations of 0.01″ NAS5-26555.

Enhancement of photocurrent in epitaxial lift-off thin-film GaInNAsSb solar cells due to light-confinement structure

NASA Astrophysics Data System (ADS)

Miyashita, Naoya; Behaghel, Benoît; Guillemoles, Jean-François; Okada, Yoshitaka

2018-07-01

This work focuses on the characterization of GaInNAsSb solar cells whose substrates are removed via the epitaxial lift-off (ELO) technique. As a result of the substrate removal, increases in the photocurrent and the interference feature were clearly observed. This is clear evidence of the light-confinement effect, whereby some of the unabsorbed photons at the rear metal contact were reflected back towards the front side of the ELO thin-film cell. We successfully demonstrated that the ELO technique can be applied for the GaInNAsSb cell, and the light management should add flexibility in designing the cell structures.

Batch Conversion of 1-D FITS Spectra to Common Graphical Display Files

NASA Astrophysics Data System (ADS)

MacConnell, Darrell J.; Patterson, A. P.; Wing, R. F.; Costa, E.; Jedrzejewski, R. I.

2008-09-01

Authors DJM, RFW, and EC have accumulated about 1000 spectra of cool stars from CTIO, ESO, and LCO over the interval 1985 to 1994 and processed them with the standard IRAF tasks into FITS files of normalized intensity vs. wavelength. With the growth of the Web as a means of exchanging and preserving scientific information, we desired to put the spectra into a Web-readable format. We have searched without success sites such as the Goddard FITS Image Viewer page, http://fits.gsfc.nasa.gov/fits_viewer.html, for a program to convert a large number of 1-d stellar spectra from FITS format into common formats such as PDF, PS, or PNG. Author APP has written a Python script to do this using the PyFITS module and plotting routines from Pylab. The program determines the wavelength calibration using header keywords and creates PNG plots with a legend read from a CSV file that may contain the star name, position, spectral type, etc. It could readily be adapted to perform almost any kind of simple batch processing of astronomical data. The program may be obtained from the first author (jack@stsci.edu). Support for DJM from the research program for CSC astronomers at STScI is gratefully acknowledged. The Space Telescope Science Institute is operated by the Association of Universities for Research in Astronomy Inc. under NASA contract NAS 5-26555.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project

NASA Technical Reports Server (NTRS)

Shively, Jay

2017-01-01

Over the past 5 years, the UAS integration into the NAS project has worked to reduce technical barriers to integration. A major focus of this work has been in support of RTCA SC-228. This committee has recently published the first UAS integration minimum performance standards (MOPS). This work has spanned detect and avoid (DAA) as well as command and control comm datalinks. I will discuss DAA efforts with focus on the human systems work. I will discuss how automation was discussed and addressed within this context. ICAO stood up a remotely piloted aircraft systems (RPAS) panel in 2014. They have developed an RPAS manual and are now working to revise existing annexes and standards and recommended practices. The Human In The System (HITS) has worked to infuse human factors guidelines into those documents. I will discuss that effort as well as how ICAO has defined and address autonomy. There is a great deal of interest in the control of multiple vehicles by a single operator. The UAS EXCOM Science and Research Panel (SARP) is holding a workshop on this topic in late June. I will discuss research performed on this topic when I worked for the Army and on-going work within the division and a NATO working group on Human-Autonomy Teaming.

The Hubble Space Telescope Wide Field Camera 3 Early Release Science Data: Panchromatic Faint Object Counts From 0.2-2 Micron To Ab=26-27 Mag

NASA Astrophysics Data System (ADS)

Windhorst, Rogier A.; McCarthy, P.; Cohen, S.; Ryan, R.; Driver, S.; Hathi, N.; Koekemoer, A.; Mechtley, M.; O'Connell, R.; Rutkowski, M.; Yan, H.; SOC, WFC3

2010-01-01

We describe the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) Early Release Science (ERS) observations in the GOODS-South field. The new WFC3 ERS data provide calibrated, drizzled mosaics with FHWM=0.07--0.15" in the near-UV (filters F225W, F275W, and F336W) and near-IR (F098W, F125W, and F160W) in typically 2 orbits per filter. Together with the existing HST/ACS GOODS-S mosaics in the BVi'z' filters, the 10-band ERS data cover 40-50 sq. arcmin to AB=26-27.0 mag (10-sigma for point sources). In this poster, we describe the: (1) scientific rationale, data taking and reduction procedures of the WFC3 ERS mosaics; (2) object cataloging and star-galaxy separation techniques used in these 10 different filters; (3) reliability and completeness of the 10-band object catalogs from the ERS mosaics; (4) object counts in 10 different filters from 0.2-1.7 microns to AB=26.0-27.0 mag; and (5) the full-color 10-band ERS images. We discuss the panchromatic structure for a variety of interesting ERS objects at intermediate redshifts (z=0.5-3), including examples of galaxies with nuclear star-forming rings, bars, or weak AGN activity, UV-dropout galaxies at redshifts z=2-3, and objects of other interesting appearance. The 10-band panchromatic ERS data base is very rich in morphological structure at all restframe wavelengths where young or older stars shine during the peak epoch in the cosmic star-formation rate (at z=1-2). This work is based on ERS observations made by the WFC3 Scientific Oversight Committee. We are grateful to the Space Telescope Science Institute Director for awarding Director's Discretionary time for this program. Support for HST program 11359 was provided by NASA through grants GO-11359.0*.A from STScI, which is operated by AURA under NASA contract NAS 5-26555. We dedicate this paper to the memory of the STS-107 Columbia Shuttle astronauts, and of Dr. Rodger Doxsey.

Unmanned Aircraft Systems (UAS): Addressing the Regulatory Issues for National Airspace System (NAS) Integration

DTIC Science & Technology

2009-04-01

terms of IFR operations or passenger enplanements. The configuration of each Class B airspace area is individually tailored and consists of a surface...are serviced by a radar approach control, and that have a certain number of IFR operations or passenger enplanements. Although the configuration of...ft MSL Figure 3 depicts DoD UASs operating in their respective NAS classifications: Global Hawk Predator B Transponder See & Avoid DME IFR

The State-of-the-art HST Astro-photometric Analysis of the Core of ω Centauri. III. The Main Sequence's Multiple Populations Galore

NASA Astrophysics Data System (ADS)

Bellini, A.; Milone, A. P.; Anderson, J.; Marino, A. F.; Piotto, G.; van der Marel, R. P.; Bedin, L. R.; King, I. R.

2017-08-01

We take advantage of the exquisite quality of the Hubble Space Telescope 26-filter astro-photometric catalog of the core of ω Cen presented in the first paper of this series and the empirical differential-reddening correction presented in the second paper in order to distill the main sequence into its constituent populations. To this end, we restrict ourselves to the five most useful filters: the magic “trio” of F275W, F336W, and F438W, along with F606W and F814W. We develop a strategy for identifying color systems where different populations stand out most distinctly, then we isolate those populations and examine them in other filters where their subpopulations also come to light. In this way, we have identified at least 15 subpopulations, each of which has a distinctive fiducial curve through our five-dimensional photometric space. We confirm the MSa to be split into two subcomponents, and find that both the bMS and the rMS are split into three subcomponents. Moreover, we have discovered two additional MS groups: the MSd (which has three subcomponents) shares similar properties with the bMS, and the MSe (which has four subcomponents) has properties more similar to those of the rMS. We examine the fiducial curves together and use synthetic spectra to infer relative heavy-element, light-element, and helium abundances for the populations. Our findings show that the stellar populations and star formation history of ω Cen are even more complex than inferred previously. Finally, we provide as a supplement to the original catalog a list that identifies for each star which population it is most likely associated with. Based on archival observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

The MASSIVE Survey. IX. Photometric Analysis of 35 High-mass Early-type Galaxies with HST WFC3/IR

NASA Astrophysics Data System (ADS)

Goullaud, Charles F.; Jensen, Joseph B.; Blakeslee, John P.; Ma, Chung-Pei; Greene, Jenny E.; Thomas, Jens

2018-03-01

We present near-infrared observations of 35 of the most massive early-type galaxies in the local universe. The observations were made using the infrared channel of the Hubble Space Telescope Wide Field Camera 3 (WFC3) in the F110W (1.1 μm) filter. We measured surface brightness profiles and elliptical isophotal fit parameters from the nuclear regions out to a radius of ∼10 kpc in most cases. We find that 37% (13) of the galaxies in our sample have isophotal position-angle rotations greater than 20° over the radial range imaged by WFC3/IR, which is often due to the presence of neighbors or multiple nuclei. Most galaxies in our sample are significantly rounder near the center than in the outer regions. This sample contains 6 fast rotators and 28 slow rotators. We find that all fast rotators are either disky or show no measurable deviation from purely elliptical isophotes. Among slow rotators, significantly disky and boxy galaxies occur with nearly equal frequency. The galaxies in our sample often exhibit changing isophotal shapes, sometimes showing both significantly disky and boxy isophotes at different radii. The fact that parameters vary widely between galaxies and within individual galaxies is evidence that these massive galaxies have complicated formation histories, and some of them have experienced recent mergers and have not fully relaxed. These data demonstrate the value of IR imaging of galaxies at high spatial resolution and provide measurements necessary for determining stellar masses, dynamics, and black hole masses in high-mass galaxies. 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 NAS 5-26555. These observations are associated with Program GO-14219.

Legacy ExtraGalactic UV Survey with The Hubble Space Telescope: Stellar Cluster Catalogs and First Insights Into Cluster Formation and Evolution in NGC 628

NASA Astrophysics Data System (ADS)

Adamo, A.; Ryon, J. E.; Messa, M.; Kim, H.; Grasha, K.; Cook, D. O.; Calzetti, D.; Lee, J. C.; Whitmore, B. C.; Elmegreen, B. G.; Ubeda, L.; Smith, L. J.; Bright, S. N.; Runnholm, A.; Andrews, J. E.; Fumagalli, M.; Gouliermis, D. A.; Kahre, L.; Nair, P.; Thilker, D.; Walterbos, R.; Wofford, A.; Aloisi, A.; Ashworth, G.; Brown, T. M.; Chandar, R.; Christian, C.; Cignoni, M.; Clayton, G. C.; Dale, D. A.; de Mink, S. E.; Dobbs, C.; Elmegreen, D. M.; Evans, A. S.; Gallagher, J. S., III; Grebel, E. K.; Herrero, A.; Hunter, D. A.; Johnson, K. E.; Kennicutt, R. C.; Krumholz, M. R.; Lennon, D.; Levay, K.; Martin, C.; Nota, A.; Östlin, G.; Pellerin, A.; Prieto, J.; Regan, M. W.; Sabbi, E.; Sacchi, E.; Schaerer, D.; Schiminovich, D.; Shabani, F.; Tosi, M.; Van Dyk, S. D.; Zackrisson, E.

2017-06-01

We report the large effort that is producing comprehensive high-level young star cluster (YSC) catalogs for a significant fraction of galaxies observed with the Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. We present the methodology developed to extract cluster positions, verify their genuine nature, produce multiband photometry (from NUV to NIR), and derive their physical properties via spectral energy distribution fitting analyses. We use the nearby spiral galaxy NGC 628 as a test case for demonstrating the impact that LEGUS will have on our understanding of the formation and evolution of YSCs and compact stellar associations within their host galaxy. Our analysis of the cluster luminosity function from the UV to the NIR finds a steepening at the bright end and at all wavelengths suggesting a dearth of luminous clusters. The cluster mass function of NGC 628 is consistent with a power-law distribution of slopes ˜ -2 and a truncation of a few times 105 {M}⊙ . After their formation, YSCs and compact associations follow different evolutionary paths. YSCs survive for a longer time frame, confirming their being potentially bound systems. Associations disappear on timescales comparable to hierarchically organized star-forming regions, suggesting that they are expanding systems. We find mass-independent cluster disruption in the inner region of NGC 628, while in the outer part of the galaxy there is little or no disruption. We observe faster disruption rates for low mass (≤104 {M}⊙ ) clusters, suggesting that a mass-dependent component is necessary to fully describe the YSC disruption process in NGC 628. Based on observations obtained with the NASA/ESA Hubble Space Telescope, at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

A Novel Approach to Constrain the Mass Ratio of Minor Mergers in Elliptical Galaxies: Application to NGC 4889, the Brightest Cluster Galaxy in Coma

NASA Astrophysics Data System (ADS)

Gu, Meng; Ho, Luis C.; Peng, Chien Y.; Huang, Song

2013-08-01

Minor mergers are thought to be important for the buildup and structural evolution of massive elliptical galaxies. In this work, we report the discovery of a system of four shell features in NGC 4889, one of the brightest members of the Coma cluster, using optical images taken with the Hubble Space Telescope and the Sloan Digital Sky Survey. The shells are well aligned with the major axis of the host and are likely to have been formed by the accretion of a small satellite galaxy. We have performed a detailed two-dimensional photometric decomposition of NGC 4889 and of the many overlapping nearby galaxies in its vicinity. This comprehensive model allows us not only to firmly detect the low-surface brightness shells, but, crucially, also to accurately measure their luminosities and colors. The shells are bluer than the underlying stars at the same radius in the main galaxy. We make use of the colors of the shells and the color-magnitude relation of the Coma cluster to infer the luminosity (or mass) of the progenitor galaxy. The shells in NGC 4889 appear to have been produced by the minor merger of a moderate-luminosity (MI ≈ -18.7 mag) disk (S0 or spiral) galaxy with a luminosity (mass) ratio of ~90:1 with respect to the primary galaxy. The novel methodology presented in this work can be exploited to decode the fossil record imprinted in the photometric substructure of other nearby early-type galaxies. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS5-26555.

The Carnegie-Chicago Hubble Program: Discovery of the Most Distant Ultra-faint Dwarf Galaxy in the Local Universe

NASA Astrophysics Data System (ADS)

Lee, Myung Gyoon; Jang, In Sung; Beaton, Rachael; Seibert, Mark; Bono, Giuseppe; Madore, Barry

2017-02-01

Ultra-faint dwarf galaxies (UFDs) are the faintest known galaxies, and due to their incredibly low surface brightness, it is difficult to find them beyond the Local Group. We report a serendipitous discovery of a UFD, Fornax UFD1, in the outskirts of NGC 1316, a giant galaxy in the Fornax cluster. The new galaxy is located at a projected radius of 55 kpc in the south-east of NGC 1316. This UFD is found as a small group of resolved stars in the Hubble Space Telescope images of a halo field of NGC 1316, obtained as part of the Carnegie-Chicago Hubble Program. Resolved stars in this galaxy are consistent with being mostly metal-poor red giant branch (RGB) stars. Applying the tip of the RGB method to the mean magnitude of the two brightest RGB stars, we estimate the distance to this galaxy, 19.0 ± 1.3 Mpc. Fornax UFD1 is probably a member of the Fornax cluster. The color-magnitude diagram of these stars is matched by a 12 Gyr isochrone with low metallicity ([Fe/H] ≈ -2.4). Total magnitude and effective radius of Fornax UFD1 are MV ≈ -7.6 ± 0.2 mag and reff = 146 ± 9 pc, which are similar to those of Virgo UFD1 that was discovered recently in the intracluster field of Virgo by Jang & Lee. Fornax UFD1 is the most distant known UFD that is confirmed by resolved stars. This indicates that UFDs are ubiquitous and that more UFDs remain to be discovered in the Fornax cluster. Based on observations made 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 NAS 5-26555. These observations are associated with programs #10505 and #13691.

The Carnegie-Chicago Hubble Program. I. An Independent Approach to the Extragalactic Distance Scale Using Only Population II Distance Indicators

NASA Astrophysics Data System (ADS)

Beaton, Rachael L.; Freedman, Wendy L.; Madore, Barry F.; Bono, Giuseppe; Carlson, Erika K.; Clementini, Gisella; Durbin, Meredith J.; Garofalo, Alessia; Hatt, Dylan; Jang, In Sung; Kollmeier, Juna A.; Lee, Myung Gyoon; Monson, Andrew J.; Rich, Jeffrey A.; Scowcroft, Victoria; Seibert, Mark; Sturch, Laura; Yang, Soung-Chul

2016-12-01

We present an overview of the Carnegie-Chicago Hubble Program, an ongoing program to obtain a 3% measurement of the Hubble constant (H 0) using alternative methods to the traditional Cepheid distance scale. We aim to establish a completely independent route to H 0 using RR Lyrae variables, the tip of the red giant branch (TRGB), and Type Ia supernovae (SNe Ia). This alternative distance ladder can be applied to galaxies of any Hubble type, of any inclination, and, using old stars in low-density environments, is robust to the degenerate effects of metallicity and interstellar extinction. Given the relatively small number of SNe Ia host galaxies with independently measured distances, these properties provide a great systematic advantage in the measurement of H 0 via the distance ladder. Initially, the accuracy of our value of H 0 will be set by the five Galactic RR Lyrae calibrators with Hubble Space Telescope Fine-Guidance Sensor parallaxes. With Gaia, both the RR Lyrae zero-point and TRGB method will be independently calibrated, the former with at least an order of magnitude more calibrators and the latter directly through parallax measurement of tip red giants. As the first end-to-end “distance ladder” completely independent of both Cepheid variables and the Large Magellanic Cloud, this path to H 0 will allow for the high-precision comparison at each rung of the traditional distance ladder that is necessary to understand tensions between this and other routes to H 0. Based on observations made 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 NAS 5-26555. These observations are associated with programs #13472 and #13691.

Toward a Safety Risk-Based Classification of Unmanned Aircraft

NASA Technical Reports Server (NTRS)

Torres-Pomales, Wilfredo

2016-01-01

There is a trend of growing interest and demand for greater access of unmanned aircraft (UA) to the National Airspace System (NAS) as the ongoing development of UA technology has created the potential for significant economic benefits. However, the lack of a comprehensive and efficient UA regulatory framework has constrained the number and kinds of UA operations that can be performed. This report presents initial results of a study aimed at defining a safety-risk-based UA classification as a plausible basis for a regulatory framework for UA operating in the NAS. Much of the study up to this point has been at a conceptual high level. The report includes a survey of contextual topics, analysis of safety risk considerations, and initial recommendations for a risk-based approach to safe UA operations in the NAS. The next phase of the study will develop and leverage deeper clarity and insight into practical engineering and regulatory considerations for ensuring that UA operations have an acceptable level of safety.

The high-velocity outflow in the proto-planetary nebula Hen 3-1475

NASA Astrophysics Data System (ADS)

Riera, A.; García-Lario, P.; Manchado, A.; Bobrowsky, M.; Estalella, R.

2003-04-01

Canarias, and observations made with the Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Operational Overview for Unmanned Aircraft Systems (UAS) Integration in the National Airspace (NAS) Project Flight Test Series 3

NASA Technical Reports Server (NTRS)

Valkov, Steffi

2017-01-01

This presentation is a high level overview of the flight testing that took place in 2015 for the UAS-NAS project. All topics in the presentation discussed at a high level and no technical details are provided.

The Phases Differential Astrometry Data Archive. 5. Candidate Substellar Companions to Binary Systems

DTIC Science & Technology

2010-12-01

Mathematics and Astronomy , 105-24, California Institute of Technology, Pasadena, CA 91125, USA 5 Nicolaus Copernicus Astronomical Center, Polish Academy...Blind Test with support from NASA contract NAS7-03001 (JPL 1336910). PHASES is funded in part by the California Institute of Technol- ogy Astronomy

Detection of Neutral Phosphorus in the Near-ultraviolet Spectra of Late-type Stars

NASA Astrophysics Data System (ADS)

Roederer, Ian U.; Jacobson, Heather R.; Thanathibodee, Thanawuth; Frebel, Anna; Toller, Elizabeth

2014-12-01

We report the detection of several absorption lines of neutral phosphorus (P, Z = 15) in archival near-ultraviolet spectra obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. We derive phosphorus abundances or interesting upper limits in 14 late-type stars with metallicities spanning -3.8 < [Fe/H] <-0.1. Previously, phosphorus had only been studied in Galactic stars with -1.0 < [Fe/H] <+0.3. Iron lines reveal abundance offsets between the optical and ultraviolet regions, and we discuss and apply a correction factor to account for this offset. In stars with [Fe/H] >-1.0, the [P/Fe] ratio decreases toward the solar value with increasing metallicity, in agreement with previous observational studies. In stars with [Fe/H] <-1.0, lang[P/Fe]rang = +0.04 ± 0.10, which overlaps with the [P/Fe] ratios found in several high-redshift damped Lyman-α systems. This behavior hints at a primary origin in massive stars. Based on observations made 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 NAS 5-26555. This work is supported through program AR-13246 and is based on observations associated with programs GO-7348, GO-7433, GO-8197, GO-9048, GO-9049, GO-9455, GO-9804, GO-12268, GO-12554, and GO-12976. Portions of this work are based on data obtained from the European Southern Observatory (ESO) Science Archive Facility. These data are associated with Programs 065.L-0507(A), 067.D-0439(A), 072.B-0179(A), 074.C-0364(A), 076.B-0055(A), and 266.D-5655(A). Portions of this research have also made use of the Keck Observatory Archive (KOA), which is operated by the W.M. Keck Observatory and the NASA Exoplanet Science Institute (NExScI), under contract with the National Aeronautics and Space Administration. These data are associated with Programs H2aH (P.I: Boesgaard), H5aH (P.I: Stephens), and H47a

The DAFT/FADA survey. I. Photometric redshifts along lines of sight to clusters in the z = [0.4, 0.9] interval

NASA Astrophysics Data System (ADS)

Guennou, L.; Adami, C.; Ulmer, M. P.; Lebrun, V.; Durret, F.; Johnston, D.; Ilbert, O.; Clowe, D.; Gavazzi, R.; Murphy, K.; Schrabback, T.; Allam, S.; Annis, J.; Basa, S.; Benoist, C.; Biviano, A.; Cappi, A.; Kubo, J. M.; Marshall, P.; Mazure, A.; Rostagni, F.; Russeil, D.; Slezak, E.

2010-11-01

Coordinating Facility. STScI is operated by the association of Universities for Research in Astronomy, Inc. under the NASA contract NAS 5-26555. Also based on observations made with ESO Telescopes at Paranal and La Silla Observatories under programme ESO LP 166.A-0162. Also based on visiting astronomer observations, at Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy, under contract with the National Science Foundation.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project. NASA Contributions to the SARP WC Definition

NASA Technical Reports Server (NTRS)

Randall, Debra K.; Consiglio, Maria Cristina; Santiago, Confesor

2014-01-01

To better inform sense and avoid research needs and to understand ongoing investigation of potential solutions that ultimately lead to the assisting the FAA with their Congressional mandate to fly UAS in the NAS.

EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments (External Review Draft)

EPA Science Inventory