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Sample records for poliuretano nas propriedades

  1. NAS: The first year

    NASA Technical Reports Server (NTRS)

    Bailey, F. R.; Kutler, Paul

    1988-01-01

    Discussed are the capabilities of NASA's Numerical Aerodynamic Simulation (NAS) Program and its application as an advanced supercomputing system for computational fluid dynamics (CFD) research. First, the paper describes the NAS computational system, called the NAS Processing System Network, and the advanced computational capabilities it offers as a consequence of carrying out the NAS pathfinder objective. Second, it presents examples of pioneering CFD research accomplished during NAS's first operational year. Examples are included which illustrate CFD applications for predicting fluid phenomena, complementing and supplementing experimentation, and aiding in design. Finally, pacing elements and future directions for CFD and NAS are discussed.

  2. The NAS Parallel Benchmarks

    SciTech Connect

    Bailey, David H.

    2009-11-15

    The NAS Parallel Benchmarks (NPB) are a suite of parallel computer performance benchmarks. They were originally developed at the NASA Ames Research Center in 1991 to assess high-end parallel supercomputers. Although they are no longer used as widely as they once were for comparing high-end system performance, they continue to be studied and analyzed a great deal in the high-performance computing community. The acronym 'NAS' originally stood for the Numerical Aeronautical Simulation Program at NASA Ames. The name of this organization was subsequently changed to the Numerical Aerospace Simulation Program, and more recently to the NASA Advanced Supercomputing Center, although the acronym remains 'NAS.' The developers of the original NPB suite were David H. Bailey, Eric Barszcz, John Barton, David Browning, Russell Carter, LeoDagum, Rod Fatoohi, Samuel Fineberg, Paul Frederickson, Thomas Lasinski, Rob Schreiber, Horst Simon, V. Venkatakrishnan and Sisira Weeratunga. The original NAS Parallel Benchmarks consisted of eight individual benchmark problems, each of which focused on some aspect of scientific computing. The principal focus was in computational aerophysics, although most of these benchmarks have much broader relevance, since in a much larger sense they are typical of many real-world scientific computing applications. The NPB suite grew out of the need for a more rational procedure to select new supercomputers for acquisition by NASA. The emergence of commercially available highly parallel computer systems in the late 1980s offered an attractive alternative to parallel vector supercomputers that had been the mainstay of high-end scientific computing. However, the introduction of highly parallel systems was accompanied by a regrettable level of hype, not only on the part of the commercial vendors but even, in some cases, by scientists using the systems. As a result, it was difficult to discern whether the new systems offered any fundamental performance advantage

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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

  8. UAS-NAS Stakeholder Feedback Report

    NASA Technical Reports Server (NTRS)

    Randall, Debra; Murphy, Jim; Grindle, Laurie

    2016-01-01

    The need to fly UAS in the NAS to perform missions of vital importance to national security and defense, emergency management, science, and to enable commercial applications has been continually increasing over the past few years. To address this need, the NASA Aeronautics Research Mission Directorate (ARMD) Integrated Aviation Systems Program (IASP) formulated and funded the Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project (hereafter referred to as UAS-NAS Project) from 2011 to 2016. The UAS-NAS Project identified the following need statement: The UAS community needs routine access to the global airspace for all classes of UAS. The Project identified the following goal: To provide research findings to reduce technical barriers associated with integrating UAS into the NAS utilizing integrated system level tests in a relevant environment. This report provides a summary of the collaborations between the UAS-NAS Project and its primary stakeholders and how the Project applied and incorporated the feedback.

  9. 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.

  10. 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.

  11. Handler Reflects on NAS, Science Issues

    ERIC Educational Resources Information Center

    Lepkowski, Wil

    1978-01-01

    The current president of the National Academy of Science (NAS) is interviewed in this article. He discusses the reorganization of NAS and the National Research Council during his term of office. Concerns over environmental science, biochemistry research, and the decreasing role of science advisors to the Pentagon are presented. (MA)

  12. 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.

  13. 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.

  14. 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.

  15. Status and projections of the NAS program

    NASA Technical Reports Server (NTRS)

    Bailey, Frank R.

    1986-01-01

    NASA's Numerical Aerodynamic Simulation (NAS) Program has completed development of the initial operating configuration of the NAS Processing System Network (NPSN). This is the first milestone in the continuing and pathfinding effort to provide state-of-the-art supercomputing for aeronautics research and development. The NPSN, available to a nation-wide community of remote users, provides a uniform UNIX environment over a network of host computers ranging from the Cray-2 supercomputer to advanced scientific workstations. This system, coupled with a vendor-independent base of common user interface and network software, presents a new paradigm for supercomputing environments. Background leading to the NAS program, its programmatic goals and strategies, technical goals and objectives, and the development activities leading to the current NPSN configuration are presented. Program status, near-term plans, and plans for the next major milestone, the extended operating configuration, are also discussed.

  16. 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…

  17. Comparative study of defect levels in GaInNAs, GaNAsSb, and GaInNAsSb for high-efficiency solar cells

    NASA Astrophysics Data System (ADS)

    Polojärvi, Ville; Aho, Arto; Tukiainen, Antti; Schramm, Andreas; Guina, Mircea

    2016-03-01

    Background doping and defect levels in GaInNAs, GaNAsSb, and GaInNAsSb solar cells with 1 eV band-gap are reported. Localized point defect induced traps were observed showing broadest defect distribution in GaInNAsSb. Incorporation of Sb reduced the unintentional p-type background doping by an order of magnitude, but increased the capture cross sections of deep levels by three orders of magnitude. The thermal activation energy of the dominating hole trap was increased from 350 meV for GaInNAs to 560 meV for GaNAsSb. Annealing of GaNAsSb solar cells improved the open circuit voltage from 280 mV to 415 mV, owing to the reduction in trap density.

  18. 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.

  19. 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.

  20. NAS Grid Benchmarks. 1.0

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    We provide a paper-and-pencil specification of a benchmark suite for computational grids. It is based on the NAS (NASA Advanced Supercomputing) Parallel Benchmarks (NPB) and is called the NAS Grid Benchmarks (NGB). NGB problems are presented as data flow graphs encapsulating an instance of a slightly modified NPB task in each graph node, which communicates with other nodes by sending/receiving initialization data. Like NPB, NGB specifies several different classes (problem sizes). In this report we describe classes S, W, and A, and provide verification values for each. The implementor has the freedom to choose any language, grid environment, security model, fault tolerance/error correction mechanism, etc., as long as the resulting implementation passes the verification test and reports the turnaround time of the benchmark.

  1. 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.

  2. NAS Parallel Benchmarks Results 3-95

    NASA Technical Reports Server (NTRS)

    Saini, Subhash; Bailey, David H.; Walter, Howard (Technical Monitor)

    1995-01-01

    The NAS Parallel Benchmarks (NPB) were developed in 1991 at NASA Ames Research Center to study the performance of parallel supercomputers. The eight benchmark problems are specified in a "pencil and paper" fashion, i.e., the complete details of the problem are given in a NAS technical document. Except for a few restrictions, benchmark implementors are free to select the language constructs and implementation techniques best suited for a particular system. In this paper, we present new NPB performance results for the following systems: (a) Parallel-Vector Processors: CRAY C90, CRAY T90 and Fujitsu VPP500; (b) Highly Parallel Processors: CRAY T3D, IBM SP2-WN (Wide Nodes), and IBM SP2-TN2 (Thin Nodes 2); and (c) Symmetric Multiprocessors: Convex Exemplar SPPIOOO, CRAY J90, DEC Alpha Server 8400 5/300, and SGI Power Challenge XL (75 MHz). We also present sustained performance per dollar for Class B LU, SP and BT benchmarks. We also mention future NAS plans for the NPB.

  3. Carrier spin relaxation in GaInNAsSb/GaNAsSb/GaAs quantum well

    SciTech Connect

    Asami, T.; Nosho, H.; Tackeuchi, A.; Li, L. H.; Harmand, J. C.; Lu, S. L.

    2011-12-23

    We have investigated the carrier spin relaxation in GaInNAsSb/GaNAsSb/GaAs quantum well (QW) by time-resolved photoluminescence (PL) measurement. The sample consists of an 8-nm-thick GaIn{sub 0.36}N{sub 0.006}AsSb{sub 0.015} well, 5-nm-thick GaN{sub 0.01}AsSb{sub 0.11} intermediate barriers and 100-nm-thick GaAs barriers grown by molecular beam epitaxy on a GaAs(100) substrate. The spin relaxation time and recombination lifetime at 10 K are measured to be 228 ps and 151 ps, respectively. As a reference, we have also obtained a spin relaxation time of 125 ps and a recombination lifetime of 63 ps for GaInNAs/GaNAs/GaAs QW. This result shows that crystal quality is slightly improved by adding Sb, although these short carrier lifetimes mainly originate from a nonradiative recombination. These spin relaxation times are longer than the 36 ps spin relaxation time of InGaAs/InP QWs and shorter than the 2 ns spin relaxation time of GaInNAs/GaAs QW.

  4. 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.

  5. Remote access for NAS: Supercomputing in a university environment

    NASA Technical Reports Server (NTRS)

    Johnson, G.; Olson, B.; Swisshelm, J.; Pryor, D.; Ziebarth, J.

    1986-01-01

    The experiment was designed to assist the Numerical Aerodynamic Simulation (NAS) Project Office in the testing and evaluation of long haul communications for remote users. The objectives of this work were to: (1) use foreign workstations to remotely access the NAS system; (2) provide NAS with a link to a large university-based computing facility which can serve as a model for a regional node of the Long-Haul Communications Subsystem (LHCS); and (3) provide a tail circuit to the University of Colorado a Boulder thereby simulating the complete communications path from NAS through a regional node to an end-user.

  6. NAS Parallel Benchmarks, Multi-Zone Versions

    NASA Technical Reports Server (NTRS)

    vanderWijngaart, Rob F.; Haopiang, Jin

    2003-01-01

    We describe an extension of the NAS Parallel Benchmarks (NPB) suite that involves solving the application benchmarks LU, BT and SP on collections of loosely coupled discretization meshes. The solutions on the meshes are updated independently, but after each time step they exchange boundary value information. This strategy, which is common among structured-mesh production flow solver codes in use at NASA Ames and elsewhere, provides relatively easily exploitable coarse-grain parallelism between meshes. Since the individual application benchmarks also allow fine-grain parallelism themselves, this NPB extension, named NPB Multi-Zone (NPB-MZ), is a good candidate for testing hybrid and multi-level parallelization tools and strategies.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. The NAS Parallel Benchmarks 2.1 Results

    NASA Technical Reports Server (NTRS)

    Saphir, William; Woo, Alex; Yarrow, Maurice

    1996-01-01

    We present performance results for version 2.1 of the NAS Parallel Benchmarks (NPB) on the following architectures: IBM SP2/66 MHz; SGI Power Challenge Array/90 MHz; Cray Research T3D; and Intel Paragon. The NAS Parallel Benchmarks are a widely-recognized suite of benchmarks originally designed to compare the performance of highly parallel computers with that of traditional supercomputers.

  12. 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).

  13. Photoreflectance spectroscopy of step-like GaInNAs/GaInNAs/GaAs quantum wells

    NASA Astrophysics Data System (ADS)

    Kudrawiec, R.; Andrzejewski, J.; Misiewicz, J.; Gollub, D.; Forchel, A.

    2005-05-01

    Photoreflectance (PR) spectroscopy has been applied to study of step-like GaInNAs/GaInNAs/GaAs double quantum well (DQW) structures grown by molecular beam epitaxy. PR features related to optical transitions in the active part of the step-like QW structure, i.e. GaInNAs/GaInNAs QW, as well as PR features related to transitions above the step-like barrier (SLB) have been clearly observed and analysed in this paper. The analysis of the QW transitions gives information about the number of confined states in the active part of the step-like QW structure. In addition, the analysis of the second portion of PR signal gives information about the band gap energy of the SLB and optical transitions between hole and electron levels confined above the SLB.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Advanced Intermediate-Temperature Na-S Battery

    SciTech Connect

    Lu, Xiaochuan; Kirby, Brent W.; Xu, Wu; Li, Guosheng; Kim, Jin Yong; Lemmon, John P.; Sprenkle, Vincent L.; Yang, Zhenguo

    2012-11-12

    In this study, we reported an intermediate-temperature (~150°C) sodium-sulfur (Na-S) battery. With a reduced operating temperature, this novel battery can potentially reduce the cost and safety issues associated with the conventional high-temperature (300~350°C) Na-S battery. A dense β"-Al2O3 solid membrane and tetraglyme were utilized as the electrolyte separator and catholyte solvent in this battery. Solubility tests indicated that cathode mixture of Na2S4 and S exhibited extremely high solubility in tetraglyme (e.g., > 4.1 M for Na2S4 + 4 S). CV scans of Na2S4 in tetraglyme revealed two pairs of redox couples with peaks at around 2.22 and 1.75 V, corresponding to the redox reactions of polysulfide species. The discharge/charge profiles of the Na-S battery showed a slope region and a plateau, indicating multiple steps and cell reactions. In-situ Raman measurements during battery operation suggested that polysulfide species were formed in the sequence of Na2S5 + S → Na2S5 + Na2S4→ Na2S4 + Na2S2 during discharge and in a reverse order during charge. This battery showed dramatic improvement in rate capacity and cycling stability over room-temperature Na-S batteries, which makes it attractive for renewable energy integration and other grid related applications.

  5. 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.

  6. Graded band gap GaInNAs solar cells

    SciTech Connect

    Langer, F.; Perl, S.; Kamp, M.; Höfling, S.

    2015-06-08

    Dilute nitride GaInN(Sb)As with a band gap (E{sub g}) of 1.0 eV is a promising material for the integration in next generation multijunction solar cells. We have investigated the effect of a compositionally graded GaInNAs absorber layer on the spectral response of a GaInNAs sub cell. We produced band gap gradings (ΔE{sub g}) of up to 39 meV across a 1 μm thick GaInNAs layer. Thereby, the external quantum efficiency—compared to reference cells—was increased due to the improved extraction of photo-generated carriers from 34.0% to 36.7% for the wavelength range from 900 nm to 1150 nm. However, this device figure improvement is accompanied by a small decrease in the open circuit voltage of about 20 mV and the shift of the absorption edge to shorter wavelengths.

  7. 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.

  8. High electron mobility in Ga(In)NAs films grown by molecular beam epitaxy

    SciTech Connect

    Miyashita, Naoya; Ahsan, Nazmul; Monirul Islam, Muhammad; Okada, Yoshitaka; Inagaki, Makoto; Yamaguchi, Masafumi

    2012-11-26

    We report the highest mobility values above 2000 cm{sup 2}/Vs in Si doped GaNAs film grown by molecular beam epitaxy. To understand the feature of the origin which limits the electron mobility in GaNAs, temperature dependences of mobility were measured for high mobility GaNAs and referential low mobility GaInNAs. Temperature dependent mobility for high mobility GaNAs is similar to the GaAs case, while that for low mobility GaInNAs shows large decrease in lower temperature region. The electron mobility of high quality GaNAs can be explained by intrinsic limiting factor of random alloy scattering and extrinsic factor of ionized impurity scattering.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 1.15 Å resolution structure of the proteasome-assembly chaperone Nas2 PDZ domain

    SciTech Connect

    Singh, Chingakham R.; Lovell, Scott; Mehzabeen, Nurjahan; Chowdhury, Wasimul Q.; Geanes, Eric S.; Battaile, Kevin P.; Roelofs, Jeroen

    2014-03-25

    The proteasome-assembly chaperone Nas2 binds to the proteasome subunit Rpt5 using its PDZ domain. The structure of the Nas2 PDZ domain has been determined. The 26S proteasome is a 2.5 MDa protease dedicated to the degradation of ubiquitinated proteins in eukaryotes. The assembly of this complex containing 66 polypeptides is assisted by at least nine proteasome-specific chaperones. One of these, Nas2, binds to the proteasomal AAA-ATPase subunit Rpt5. The PDZ domain of Nas2 binds to the C-terminal tail of Rpt5; however, it does not require the C-terminus of Rpt5 for binding. Here, the 1.15 Å resolution structure of the PDZ domain of Nas2 is reported. This structure will provide a basis for further insights regarding the structure and function of Nas2 in proteasome assembly.

  16. A Comparison of Brunt Criteria, the Non Alcoholic Fatty Liver Disease Activity Score (NAS) & a Proposed NAS-including fibrosis as Valid Diagnostic Scores for NASH

    PubMed Central

    Santiago-Rolón, Amarilys; Purcell, Dagmary; Rosado, Kathia; Toro, Doris H.

    2016-01-01

    Objective Non-alcoholic steatohepatitis (NASH) can result in cirrhosis and end stage liver disease. It is of utmost importance to differentiate NASH from simple steatosis. The aim of this study is to determine the prevalence of NASH in Latino veterans with metabolic syndrome and compare histologic grading using Brunt Criteria, the NAFLD activity score (NAS), and a proposed NAS score including fibrosis. Methods Veterans with metabolic syndrome, hepatic steatosis and elevation of ALT/AST who underwent a liver biopsy from 2004-2010 were included in this study. Biopsies were evaluated by a single blinded Hepatopathologist. Steatosis, lobular inflammation, ballooning and fibrosis were graded per specimen. Each biopsy was evaluated using Brunt criteria, NAS and NAS plus fibrosis. Results Sixty patients were included in this study, 88.3% men with a mean age of 50.4 (± 12.8). 50.0% met criteria for NASH according to the Brunt system. When classifying biopsies using NAS, only 30.0% (18/60) had a score ≥5, while when adding fibrosis, the number of patients with a score ≥5 increased to 33 (55.0%). When evaluating the predictive ability of the two scoring systems, we found that NAS including fibrosis had a higher sensitivity than NAS (86.7% vs. 40.0%) and a lower specificity (76.7% vs. 80.0%). Conclusion In our population with metabolic syndrome and altered liver function tests, about 50-55% had steatohepatitis. There were significant differences between the scoring systems. When using NAS-plus-fibrosis more patients were recognized and the sensitivity increased. Further validation studies are required to evaluate this proposed NAS scoring System. PMID:26602577

  17. NAS Miramar Molten Carbonate Fuel Cell demonstration status

    SciTech Connect

    Scroppo, J.A.

    1996-12-31

    Part of M-C Power`s Technology Development Program, this MCFC power plant is designed to supply 250 kW of electricity to Naval Air Station (NAS) Miramar. It also cogenerates steam for the district heating system. The power plant is a fully integrated unit incorporating an advanced design fuel cell based on years of laboratory tests and a prior field test. This demonstration incorporates many innovative features, one of which is the plate type reformer which processes the natural gas fuel for use in the fuel cell. M-C Power Corp. has completed the design, fabrication, and conditioning of a 250-cell fuel cell stack, which was shipped to the site where it will be installed, tested, and evaluated as a 250 kW Proof-of-Concept MCFC Power Plant. (Originally going to Kaiser Permanente`s Sand Diego Medical Center, it was relocated to Miramar.)

  18. 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.

  19. The NAS EarlyBird Programme: Partnership with Parents in Early Intervention.

    ERIC Educational Resources Information Center

    Shields, Jane

    2001-01-01

    This article describes the development of an autism-specific three-month parent education program by Britain's National Autistic Society (NAS). The NAS EarlyBird Programme emphasizes partnerships with parents and uses weekly group training sessions and individualized home visits to teach parents about autism, social communication, and prevention…

  20. 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…

  1. Natural Attenuation Software (NAS): A computer program for estimating remediation times of contaminated groundwater

    USGS Publications Warehouse

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

    2004-01-01

    This paper describes the development and application of a modeling system called Natural Attenuation Software (NAS). NAS was designed as a screening tool to estimate times of remediation (TORs), associated with monitored natural attenuation (MNA), to lower groundwater contaminant concentrations to regulatory limits. Natural attenuation processes that NAS models include advection, dispersion, sorption, biodegradation, and non-aqueous phase liquid (NAPL) dissolution. This paper discusses the three main interactive components of NAS: 1) estimation of the target source concentration required for a plume extent to contract to regulatory limits, 2) estimation of the time required for NAFL contaminants in the source area to attenuate to a predetermined target source concentration, and 3) estimation of the time required for a plume extent to contract to regulatory limits after source reduction. The model's capability is illustrated by results from a case study at a MNA site, where NAS time of remediation estimates compared well with observed monitoring data over multiple years.

  2. 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.

  3. 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.

  4. Performance Comparison of HPF and MPI Based NAS Parallel Benchmarks

    NASA Technical Reports Server (NTRS)

    Saini, Subhash

    1997-01-01

    Compilers supporting High Performance Form (HPF) 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 SP2 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) combinations will be compared, based on latest NAS Parallel Benchmark 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 the following systems: DEC Alpha Server 8400 5/440, Fujitsu CAPP Series (VX, VPP300, and VPP700), HP/Convex Exemplar SPP2000, IBM RS/6000 SP P2SC node (120 MHz), NEC SX-4/32, SGI/CRAY T3E, and SGI Origin2000. We would also present sustained performance per dollar for Class B LU, SP and BT benchmarks.

  5. Spin Lifetimes in annealed GaInNAs epilayers

    NASA Astrophysics Data System (ADS)

    Tsai, Yutsung; Barman, Biplob; Scrace, Thomas; Petrou, Athos; Fukuda, Miwa; Sellers, Ian; Leroux, Mathieu; Khalfioui, Mohamed; Suny At Buffalo Collaboration; University Of Oklahoma Collaboration; Crhea-Cnrs Collaboration

    2015-03-01

    We have carried out Hanle measurements of the electron spin lifetime TSin optically pumped annealed GaInNAs epilayers (undoped and p-type doped). The samples were placed in a 7T optical magnet cryostat with the magnetic field applied in the epilayer plane. The emitted light was collected along the normal to the epilayers. The PL was excited using the 1064 nm line from a Nd:YAG laser which gives a polarization P = 5% at B =0. The transverse magnetic field results in a reduction of P, from which we determine TS. At T = 50 K, the electron spin lifetime TSwas measured to be 15 ps. As the sample temperature increases, TSdecreases (TS = 7 ps at T = 150 K). Our Hanle results are in agreement with the TSvalues measured by Lombez et al. using time-resolved photoluminescence spectroscopy. The observed sharp reduction in TSin annealed samples is interpreted as due to the D'yakonov-Perel' spin relaxation mechanism. In annealed samples the momentum relaxation time increases, resulting in a reduction of TS The authors acknowledge support through the state of Oklahoma OARs program Grant No. 12.2-040.

  6. Performance Characteristics of the Multi-Zone NAS Parallel Benchmarks

    NASA Technical Reports Server (NTRS)

    Jin, Haoqiang; VanderWijngaart, Rob F.

    2003-01-01

    We describe a new suite of computational benchmarks that models applications featuring multiple levels of parallelism. Such parallelism is often available in realistic flow computations on systems of grids, but had not previously been captured in bench-marks. The new suite, named NPB Multi-Zone, is extended from the NAS Parallel Benchmarks suite, and involves solving the application benchmarks LU, BT and SP on collections of loosely coupled discretization meshes. The solutions on the meshes are updated independently, but after each time step they exchange boundary value information. This strategy provides relatively easily exploitable coarse-grain parallelism between meshes. Three reference implementations are available: one serial, one hybrid using the Message Passing Interface (MPI) and OpenMP, and another hybrid using a shared memory multi-level programming model (SMP+OpenMP). We examine the effectiveness of hybrid parallelization paradigms in these implementations on three different parallel computers. We also use an empirical formula to investigate the performance characteristics of the multi-zone benchmarks.

  7. A Programming Model Performance Study Using the NAS Parallel Benchmarks

    DOE PAGES

    Shan, Hongzhang; Blagojević, Filip; Min, Seung-Jai; Hargrove, Paul; Jin, Haoqiang; Fuerlinger, Karl; Koniges, Alice; Wright, Nicholas J.

    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

  8. [Study on the Application of NAS-Based Algorithm in the NIR Model Optimization].

    PubMed

    Geng, Ying; Xiang, Bing-ren; He, Lan

    2015-10-01

    In this paper, net analysis signal (NAS)-based concept was introduced to the analysis of multi-component Ginkgo biloba leaf extracts. NAS algorithm was utilized for the preprocessing of spectra, and NAS-based two-dimensional correlation analysis was used for the optimization of NIR model building. Simultaneous quantitative models for three flavonol aglycones: quercetin, keampferol and isorhamnetin were established respectively. The NAS vectors calculated using two algorithms introduced from Lorber and Goicoechea and Olivieri (HLA/GO) were applied in the development of calibration models, the reconstructed spectra were used as input of PLS modeling. For the first time, NAS-based two-dimensional correlation spectroscopy was used for wave number selection. The regions appeared in the main diagonal were selected as useful regions for model building. The results implied that two NAS-based preprocessing methods were successfully used for the analysis of quercetin, keampferol and isorhamnetin with a decrease of factor number and an improvement of model robustness. NAS-based algorithm was proven to be a useful tool for the preprocessing of spectra and for optimization of model calibration. The above research showed a practical application value for the NIRS in the analysis of complex multi-component petrochemical medicine with unknown interference.

  9. [Study on the Application of NAS-Based Algorithm in the NIR Model Optimization].

    PubMed

    Geng, Ying; Xiang, Bing-ren; He, Lan

    2015-10-01

    In this paper, net analysis signal (NAS)-based concept was introduced to the analysis of multi-component Ginkgo biloba leaf extracts. NAS algorithm was utilized for the preprocessing of spectra, and NAS-based two-dimensional correlation analysis was used for the optimization of NIR model building. Simultaneous quantitative models for three flavonol aglycones: quercetin, keampferol and isorhamnetin were established respectively. The NAS vectors calculated using two algorithms introduced from Lorber and Goicoechea and Olivieri (HLA/GO) were applied in the development of calibration models, the reconstructed spectra were used as input of PLS modeling. For the first time, NAS-based two-dimensional correlation spectroscopy was used for wave number selection. The regions appeared in the main diagonal were selected as useful regions for model building. The results implied that two NAS-based preprocessing methods were successfully used for the analysis of quercetin, keampferol and isorhamnetin with a decrease of factor number and an improvement of model robustness. NAS-based algorithm was proven to be a useful tool for the preprocessing of spectra and for optimization of model calibration. The above research showed a practical application value for the NIRS in the analysis of complex multi-component petrochemical medicine with unknown interference. PMID:26904808

  10. Computational Aeroscience at NAS and Future Trends in High Performance Computing

    NASA Technical Reports Server (NTRS)

    Cooper, David M.

    1994-01-01

    NASA's Numerical Aerodynamic Simulation (NAS) program provides a unique world class supercomputing capability which is readily accessed by the U.S. aeronautics community and offers them the opportunity to perform high speed computations and simulations for a broad range of aerospace research applications. In addition, the NAS program performs on-going research and advanced technology development to ensure the innovative application of newly emerging technologies to computational fluid dynamics and other important aeroscience disciplines. The NAS system and its interaction with industry are described. Furthermore, the results of an analysis of current and future technologies and their potential impact on high performance computing are also presented.

  11. 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

    ... (NAS) Requirement for Non-Emergency Inpatient Mental Health Care AGENCY: Office of the Secretary... NAS is needed for non-emergency inpatient mental health care in order for a TRICARE Standard beneficiary's claim to be paid. Currently, NAS are required for non-emergency inpatient mental health care...

  12. 78 FR 46497 - Amendment of Class D and E Airspace, and Establishment of Class E Airspace; Oceana NAS, VA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-01

    ... Tower at Oceana NAS (Apollo Soucek Field) now operating on a part time basis. This action enhances the... also updates the geographic coordinates of Oceana NAS (Apollo Soucek Field) and NALF Fentress. DATES... airspace, and establish Class E airspace at Oceana Naval Air Station, (NAS), VA, (78 FR 21084)....

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

    SciTech Connect

    Tan, K. H.; Yoon, S. F.; Wicaksono, S.; Loke, W. K.; Li, D. S.; Saadsaoud, N.; Tripon-Canseliet, C.; Lampin, J. F.; Decoster, D.; Chazelas, J.

    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 photoconductive switch application.

  14. 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.

  15. 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.

  16. The NAS Alert System: a look at the first eight years

    USGS Publications Warehouse

    Fuller, Pam 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.

  17. Dilute-As AlNAs Alloy for Deep-Ultraviolet Emitter

    PubMed Central

    Tan, Chee-Keong; Borovac, Damir; Sun, Wei; Tansu, Nelson

    2016-01-01

    The band structures of dilute-As AlNAs alloys with As composition ranging from 0% up to 12.5% are studied by using First-Principle Density Functional Theory (DFT) calculation. The energy band gap shows remarkable reduction from 6.19 eV to 3.87 eV with small amount of As content in the AlNAs alloy, which covers the deep ultraviolet (UV) spectral regime. A giant bowing parameter of 30.5 eV ± 0.5 eV for AlNAs alloy is obtained. In addition, our analysis shows that the crossover between crystal field split-off (CH) band and heavy hole (HH) bands occurs in the dilute-As AlNAs alloy with As-content of ~1.5%. This result implies the possibility of dominant transverse electric (TE)-polarized emission by using AlNAs alloy with dilute amount of As-content. Our findings indicate the potential of dilute-As AlNAs alloy as the new active region material for TE-polarized III-Nitride-based deep UV light emitters. PMID:26905060

  18. 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

  19. Testing New Programming Paradigms with NAS Parallel Benchmarks

    NASA Technical Reports Server (NTRS)

    Jin, H.; Frumkin, M.; Schultz, M.; Yan, J.

    2000-01-01

    Over the past decade, high performance computing has evolved rapidly, not only in hardware architectures but also with increasing complexity of real applications. Technologies have been developing to aim at scaling up to thousands of processors on both distributed and shared memory systems. Development of parallel programs on these computers is always a challenging task. Today, writing parallel programs with message passing (e.g. MPI) is the most popular way of achieving scalability and high performance. However, writing message passing programs is difficult and error prone. Recent years new effort has been made in defining new parallel programming paradigms. The best examples are: HPF (based on data parallelism) and OpenMP (based on shared memory parallelism). Both provide simple and clear extensions to sequential programs, thus greatly simplify the tedious tasks encountered in writing message passing programs. HPF is independent of memory hierarchy, however, due to the immaturity of compiler technology its performance is still questionable. Although use of parallel compiler directives is not new, OpenMP offers a portable solution in the shared-memory domain. Another important development involves the tremendous progress in the internet and its associated technology. Although still in its infancy, Java promisses portability in a heterogeneous environment and offers possibility to "compile once and run anywhere." In light of testing these new technologies, we implemented new parallel versions of the NAS Parallel Benchmarks (NPBs) with HPF and OpenMP directives, and extended the work with Java and Java-threads. The purpose of this study is to examine the effectiveness of alternative programming paradigms. NPBs consist of five kernels and three simulated applications that mimic the computation and data movement of large scale computational fluid dynamics (CFD) applications. We started with the serial version included in NPB2.3. Optimization of memory and cache usage

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. GaNAsP: An intermediate band semiconductor grown by gas-source molecular beam epitaxy

    SciTech Connect

    Kuang, Y. J.; Yu, K. M.; Walukiewicz, W.; Kudrawiec, R.; Luce, A. V.; Ting, M.; Tu, C. W.

    2013-03-18

    Dilute nitride GaNAsP thin films were grown via a GaAsP metamorphic buffer on GaP(100) substrate with gas-source molecular beam epitaxy. The compositions of this III-V-V-V compound were determined by channeling Rutherford backscattering spectroscopy and nuclear reaction analysis. Photoreflectance shows two distinctive transitions from the valence band to the split conduction bands due to N incorporation. Photoluminescence and optical absorption show the fundamental bandgap of Ga(N)AsP is largely tailored by the small amount of N. The observed multiband characteristics and the bandgap tunability of GaNAsP are two merits that fit into the intermediate-band solar cell roadmap, and GaNAsP of high crystal quality provides a strong candidate for intermediate band solar cell materials.

  5. Improved performance in GaInNAs solar cells by hydrogen passivation

    NASA Astrophysics Data System (ADS)

    Fukuda, M.; Whiteside, V. R.; Keay, J. C.; Meleco, A.; Sellers, I. R.; Hossain, K.; Golding, T. D.; Leroux, M.; Al Khalfioui, M.

    2015-04-01

    The effect of UV-activated hydrogenation on the performance of GaInNAs solar cells is presented. A proof-of-principle investigation was performed on non-optimum GaInNAs cells, which allowed a clearer investigation of the role of passivation on the intrinsic nitrogen-related defects in these materials. Upon optimized hydrogenation of GaInNAs, a significant reduction in the presence of defect and impurity based luminescence is observed as compared to that of unpassivated reference material. This improvement in the optical properties is directly transferred to an improved performance in solar cell operation, with a more than two-fold improvement in the external quantum efficiency and short circuit current density upon hydrogenation. Temperature dependent photovoltaic measurements indicate a strong contribution of carrier localization and detrapping processes, with non-radiative processes dominating in the reference materials, and evidence for additional strong radiative losses in the hydrogenated solar cells.

  6. Improved performance in GaInNAs solar cells by hydrogen passivation

    SciTech Connect

    Fukuda, M.; Whiteside, V. R.; Keay, J. C.; Meleco, A.; Sellers, I. R.; Hossain, K.; Golding, T. D.; Leroux, M.; Al Khalfioui, M.

    2015-04-06

    The effect of UV-activated hydrogenation on the performance of GaInNAs solar cells is presented. A proof-of-principle investigation was performed on non-optimum GaInNAs cells, which allowed a clearer investigation of the role of passivation on the intrinsic nitrogen-related defects in these materials. Upon optimized hydrogenation of GaInNAs, a significant reduction in the presence of defect and impurity based luminescence is observed as compared to that of unpassivated reference material. This improvement in the optical properties is directly transferred to an improved performance in solar cell operation, with a more than two-fold improvement in the external quantum efficiency and short circuit current density upon hydrogenation. Temperature dependent photovoltaic measurements indicate a strong contribution of carrier localization and detrapping processes, with non-radiative processes dominating in the reference materials, and evidence for additional strong radiative losses in the hydrogenated solar cells.

  7. 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.

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

    SciTech Connect

    Jandieri, K. Ludewig, P.; Wegele, T.; Beyer, A.; Kunert, B.; Springer, P.; Baranovskii, S. D.; Koch, S. W.; Volz, K.; Stolz, W.

    2015-08-14

    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.

  9. 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.

  10. A thermo-mechanical stress prediction model for contemporary planar sodium sulfur (NaS) cells

    NASA Astrophysics Data System (ADS)

    Jung, Keeyoung; Colker, Jeffrey P.; Cao, Yuzhe; Kim, Goun; Park, Yoon-Cheol; Kim, Chang-Soo

    2016-08-01

    We introduce a comprehensive finite-element analysis (FEA) computational model to accurately predict the thermo-mechanical stresses at heterogeneous joints and components of large-size sodium sulfur (NaS) cells during thermal cycling. Quantification of the thermo-mechanical stress is important because the accumulation of stress during cell assembly and/or operation is one of the critical issues in developing practical planar NaS cells. The computational model is developed based on relevant experimental assembly and operation conditions to predict the detailed stress field of a state-of-the-art planar NaS cell. Prior to the freeze-and-thaw thermal cycle simulation, residual stresses generated from the actual high temperature cell assembly procedures are calculated and implemented into the subsequent model. The calculation results show that large stresses are developed on the outer surface of the insulating header and the solid electrolyte, where component fracture is frequently observed in the experimental cell fabrication process. The impacts of the coefficients of thermal expansion (CTE) of glass materials and the thicknesses of cell container on the stress accumulation are also evaluated to improve the cell manufacturing procedure and to guide the material choices for enhanced thermo-mechanical stability of large-size NaS cells.

  11. Composition modulation in GaInNAs quantum wells: Comparison of experiment and theory

    NASA Astrophysics Data System (ADS)

    Herrera, M.; González, D.; Hopkinson, M.; Gutiérrez, M.; Navaretti, P.; Liu, H. Y.; García, R.

    2005-04-01

    Composition modulation observed in GaInNAs quantum wells imposes an important handicap to their potential application within optical components, particularly as the indium and nitrogen contents are increased to reach longer wavelengths. In this paper, we compare our experimental results of phase separation in GaInNAs quantum wells grown at different temperatures with recent theoretical models of spinodal decomposition from the literature. This comparison has shown that the regular solution approximation, which explains the higher composition modulation compared to GaInAs samples, provides a more appropriate explanation of GaInNAs decomposition than the usual delta lattice-parameter approximation. Transmission electron microscopy shows no composition modulation contrasts with the chemical sensitive 002 dark field reflection and a strong increase in the intensity of the strain contrasts observed with 220 bright field reflection as the growth temperature increases from 360to460°C. These observations can be explained by an uncoupling between N and In composition profiles forming separate In-rich and N-rich regions according to the regular solution approximation model. We therefore believe that the compositional fluctuations in GaInNAs are not only due to GaInAs decomposition, but that an uncoupled modulation of the III and V elements is also present.

  12. Beyond the NAS Parallel Benchmarks: Measuring Dynamic Program Performance and Grid Computing Applications

    NASA Technical Reports Server (NTRS)

    VanderWijngaart, Rob F.; Biswas, Rupak; Frumkin, Michael; Feng, Huiyu; Biegel, Bryan (Technical Monitor)

    2001-01-01

    The contents include: 1) A brief history of NPB; 2) What is (not) being measured by NPB; 3) Irregular dynamic applications (UA Benchmark); and 4) Wide area distributed computing (NAS Grid Benchmarks-NGB). This paper is presented in viewgraph form.

  13. 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.

  14. 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

  15. 76 FR 57690 - TRICARE; Elimination of the Non-Availability Statement (NAS) Requirement for Non-Emergency...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-16

    ... (NAS) Requirement for Non-Emergency Inpatient Mental Health Care AGENCY: Office of the Secretary... states a NAS is needed for non-emergency inpatient mental health care in order for a TRICARE Standard... the MTF catchment area for non-emergency inpatient mental health care. Currently, the number of...

  16. 78 FR 21084 - Proposed Amendment of Class D and E Airspace, and Establishment of Class E Airspace; Oceana NAS, VA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-09

    ... Traffic Control Tower at Oceana NAS (Apollo Soucek Field) operating on a part time basis. This action... contact the FAA's Office of Rulemaking, (202) 267-9677, to request a copy of Advisory circular No. 11-2A... (Apollo Soucek Field), VA. The Air Traffic Control Tower at Oceana NAS is transitioning from a full...

  17. 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.

  18. Defect study of molecular beam epitaxy grown undoped GaInNAsSb thin film using junction-capacitance spectroscopy

    SciTech Connect

    Monirul Islam, Muhammad; Miyashita, Naoya; Ahsan, Nazmul; Okada, Yoshitaka

    2013-02-18

    Defects in undoped GaInNAsSb thin film (i-GaInNAsSb) were investigated by junction-capacitance technique using admittance and transient photocapacitance (TPC) spectroscopy. An electron trap D2 was identified at 0.34 eV below the conduction band (E{sub C}) of i-GaInNAsSb using admittance spectroscopy. Optical transition of valance band (E{sub V}) electrons to a localized state OH1 (E{sub V} + 0.75 eV) was manifested in negative TPC signal. Combined activation energy of OH1 and D2 defect corresponds to the band-gap of i-GaInNAsSb, suggesting that OH1/D2 acts as an efficient recombination center. TPC signal at {approx}1.59 eV above E{sub V} was attributed to the nitrogen-induced localized state in GaInNAsSb.

  19. 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

  20. Ubiquity and diversity of heterotrophic bacterial nasA genes in diverse marine environments.

    PubMed

    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

  1. 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

  2. Ubiquity and diversity of heterotrophic bacterial nasA genes in diverse marine environments.

    PubMed

    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

  3. First-principle natural band alignment of GaN / dilute-As GaNAs alloy

    SciTech Connect

    Tan, Chee-Keong Tansu, Nelson

    2015-01-15

    Density functional theory (DFT) calculations with the local density approximation (LDA) functional are employed to investigate the band alignment of dilute-As GaNAs alloys with respect to the GaN alloy. Conduction and valence band positions of dilute-As GaNAs alloy with respect to the GaN alloy on an absolute energy scale are determined from the combination of bulk and surface DFT calculations. The resulting GaN / GaNAs conduction to valence band offset ratio is found as approximately 5:95. Our theoretical finding is in good agreement with experimental observation, indicating the upward movements of valence band at low-As content dilute-As GaNAs are mainly responsible for the drastic reduction of the GaN energy band gap. In addition, type-I band alignment of GaN / GaNAs is suggested as a reasonable approach for future device implementation with dilute-As GaNAs quantum well, and possible type-II quantum well active region can be formed by using InGaN / dilute-As GaNAs heterostructure.

  4. 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.

  5. Moth eye antireflection coated GaInP/GaAs/GaInNAs solar cell

    NASA Astrophysics Data System (ADS)

    Aho, Arto; Tommila, Juha; Tukiainen, Antti; Polojärvi, Ville; Niemi, Tapio; Guina, Mircea

    2014-09-01

    The performance of a GaInP/GaAs/GaInNAs solar cell incorporating AlInP moth eye antireflection coating is reported and compared with the performance of a similar cell comprising TiO2/SiO2 antireflection coating. The moth eye coating exhibits an average reflectance of only 2% within the spectral range from 400 nm to 1600 nm. EQE measurements revealed absorption-related losses in the AlInP moth eye coating at wavelengths below 510 nm. Short wavelength absorption decreases the current generation in the top GaInP junction by 10%. Despite the absorption losses, the moth eye patterned GaInP/GaAs/GaInNAs solar cell exhibited higher current generation under AM1.5G real sun illumination.

  6. The temperature dependence of atomic incorporation characteristics in growing GaInNAs films

    SciTech Connect

    Li, Jingling; Gao, Fangliang; Wen, Lei; Zhou, Shizhong; Zhang, Shuguang E-mail: msgli@scut.edu.cn; Li, Guoqiang E-mail: msgli@scut.edu.cn

    2015-02-07

    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, and secondary ion mass spectroscopy.

  7. 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.

  8. Ultrahigh-Q Micromechanical Resonators by Using Epitaxially Induced Tensile Strain in GaNAs

    NASA Astrophysics Data System (ADS)

    Onomitsu, Koji; Mitsuhara, Manabu; Yamamoto, Hideki; Yamaguchi, Hiroshi

    2013-11-01

    We fabricated micromechanical resonators using epitaxially grown GaNAs, in which in-plane tensile strain is induced by the growth on GaAs substrates. The resonators show significant improvement in resonance frequency and quality factor (Q) compared with those made of unstrained GaAs. The optimization of nitrogen concentration provides a resonator with the highest room-temperature Q value so far reported for III-V materials: the obtained Q of 1.2×105 is about 30 times higher than that of resonators made of GaAs. The ultrahigh-Q GaNAs mechanical resonators are suitable for various sensing applications to unveil phenomena that have not yet been possible to examine.

  9. 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.

  10. 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.

  11. Nitrogen incorporation effects on gain properties of GaInNAs lasers : experiment and theory.

    SciTech Connect

    Thranhardt, A.; Mawst, L. J.; Hader, J.; Schlichenmaier, C.; Tansu, N.; Yeh, J. -Y.; Belenky, G.; Chow, Weng Wah; Shterengas, L.; Moloney, Jerome V.; Koch, S. W.; Kuznetsova, I.

    2005-05-01

    Gain properties of GaInNAs lasers with different nitrogen concentrations in the quantum wells are investigated experimentally and theoretically. Whereas nitrogen incorporation induces appreciable modifications in the spectral extension and the carrier density dependence of the gain, it is found that the linewidth enhancement factor is reduced by inclusion of nitrogen, but basically unaffected by different nitrogen content due to the balancing between gain and index changes.

  12. 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.

  13. Large-scale structural analysis: The structural analyst, the CSM Testbed and the NAS System

    NASA Technical Reports Server (NTRS)

    Knight, Norman F., Jr.; Mccleary, Susan L.; Macy, Steven C.; Aminpour, Mohammad A.

    1989-01-01

    The Computational Structural Mechanics (CSM) activity is developing advanced structural analysis and computational methods that exploit high-performance computers. Methods are developed in the framework of the CSM testbed software system and applied to representative complex structural analysis problems from the aerospace industry. An overview of the CSM testbed methods development environment is presented and some numerical methods developed on a CRAY-2 are described. Selected application studies performed on the NAS CRAY-2 are also summarized.

  14. NAS Parallel Benchmarks I/O Version 2.4. 2.4

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    We describe a benchmark problem, based on the Block-Tridiagonal (BT) problem of the NAS Parallel Benchmarks (NPB), which is used to test the output capabilities of high-performance computing systems, especially parallel systems. We also present a source code implementation of the benchmark, called NPBIO2.4-MPI, based on the MPI implementation of NPB, using a variety of ways to write the computed solutions to file.

  15. 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.

  16. Improved performance due to selective passivation of nitrogen clusters in GaInNAs solar cells

    NASA Astrophysics Data System (ADS)

    Fukuda, Miwa; Whiteside, Vincent R.; Al Khalfioui, Mohamed; Leroux, Mathieu; Hossain, Khalid; Sellers, Ian R.

    2015-03-01

    While GaInNAs has the potential to be a fourth-junction in multi-junction solar cells it has proved to be difficult to incorporate due to the low solubility of nitrogen in these materials. Specifically, mid-gap states attributed to nitrogen clusters have proved prohibitive for practical implementation of these systems. Here, we present the selective passivation of nitrogen impurities using a UV-activated hydrogenation process, which enables the removal of defects while retaining substitution 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, while after hydrogenation no sign of the ``s-shape'' is evident. This passivation of nitrogen centers is reflected in improved performance of solar cells structures relative to reference, unpassivated devices presenting a potential route to practical implementation of GaInNAs solar cells. The authors acknowledge support through Oklahoma Center for the Advancement of Science and Technology under the Oklahoma Applied Research Support Grant No. AR12.2-040.

  17. Optimisation of optical properties of a long-wavelength GaInNAs quantum-well laser diode

    SciTech Connect

    Alias, M S; Maskuriy, F; Faiz, F; Mitani, S M; AL-Omari, A N

    2013-11-30

    We report optimisation of optical properties of a strained GaInNAs/GaAs quantum-well laser, by taking into account the many-body effect theory and the bowing parameter. The theoretical transition energies and the GaInNAs bowing parameter are fitted into the photoluminescence spectrum of the GaInNAs quantum well, obtained in the experiment. The theoretical results for the photoluminescence spectrum and laser characteristics (light, current and voltage) exhibits a high degree of agreement with the experimental results. (lasers)

  18. A estabilidade dos PAHS em função da energia da radiação interestelar nas faixas UV e raios-X

    NASA Astrophysics Data System (ADS)

    Pinotti, R.; Costa, R. K.; Boechat-Roberty, H. M.; Lago, A.; Souza, G. B.

    2003-08-01

    A nebulosa CRL 618, uma proto-nebulosa planetária cuja nuvem molecular espessa envolve uma estrela B0, contém uma grande quantidade de C2H2 e CH4. Estas moléculas são consideradas os tijolos da criação de grandes moléculas carbonadas como os Hidrocarbonetos Policíclicos Aromáticos (PAHs). Esta nebulosa, por estar exposta a intensos campos de UV e Raios-X, é uma região de fotodissociação molecular que propicia a formação de novas moléculas, confirmada pela presença de C4H2 e C6H6 (Benzeno), que é a unidade básica dos PAHs. Atribui-se a esta família de moléculas orgânicas duas propriedades fundamentais, a resistência para sobreviver ao campo de radiação UV interestelar e a geração das bandas de emissão não identificadas (UIR) observadas no infravermelho. No entanto, alguns autores questionam a resistência dos PAHs ao campo de radiação UV interestelar. Empregando a técnica de Espectrometria de Massas por Tempo de Vôo, no modo de coincidência fotoelétron-fotoíon, estudamos a ionização e fragmentação das seguintes moléculas: Benzeno, Benzeno deuterado, Naftaleno, Antraceno e Fenantreno. Utilizamos uma fonte de Hélio monocromática em 21,21 eV (584,5 Å) e a radiação Síncroton do Laboratório Nacional de Luz Síncroton (LNLS) em diferentes energias nas proximidades da borda do C 1s ( 290 eV). Comprovamos a estabilidade dos PAHs sob ação de UV (21,21 eV), onde eles apresentam um baixo nível de fotodissociação, produzindo fragmentos ionizados com rendimento total na ordem de 5 por cento em relação ao íon molecular pai. Entretanto, em altas energias, na faixa de Raios-X, a quebra destas moléculas torna-se mais intensa, com a produção de muitos fragmentos. Como uma das rotas de fragmentação do Naftaleno é [(C10H8) = > (C6H6+) + (C4H2) + (e-)], e como temos as evidências observacionais da existência do C4H2 e C6H6 na nebulosa CRL 618, sugerimos que este ambiente também possui o Naftaleno.

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

    SciTech Connect

    Islam, Muhammad Monirul Miyashita, Naoya; Ahsan, Nazmul; Okada, Yoshitaka; Sakurai, Takeaki; Akimoto, Katsuhiro

    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.

  20. 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.

  1. 1.15 Å resolution structure of the proteasome-assembly chaperone Nas2 PDZ domain.

    PubMed

    Singh, Chingakham R; Lovell, Scott; Mehzabeen, Nurjahan; Chowdhury, Wasimul Q; Geanes, Eric S; Battaile, Kevin P; Roelofs, Jeroen

    2014-04-01

    The 26S proteasome is a 2.5 MDa protease dedicated to the degradation of ubiquitinated proteins in eukaryotes. The assembly of this complex containing 66 polypeptides is assisted by at least nine proteasome-specific chaperones. One of these, Nas2, binds to the proteasomal AAA-ATPase subunit Rpt5. The PDZ domain of Nas2 binds to the C-terminal tail of Rpt5; however, it does not require the C-terminus of Rpt5 for binding. Here, the 1.15 Å resolution structure of the PDZ domain of Nas2 is reported. This structure will provide a basis for further insights regarding the structure and function of Nas2 in proteasome assembly.

  2. 1.15 Å resolution structure of the proteasome-assembly chaperone Nas2 PDZ domain

    PubMed Central

    Singh, Chingakham R.; Lovell, Scott; Mehzabeen, Nurjahan; Chowdhury, Wasimul Q.; Geanes, Eric S.; Battaile, Kevin P.; Roelofs, Jeroen

    2014-01-01

    The 26S proteasome is a 2.5 MDa protease dedicated to the degradation of ubiquitinated proteins in eukaryotes. The assembly of this complex containing 66 polypeptides is assisted by at least nine proteasome-specific chaperones. One of these, Nas2, binds to the proteasomal AAA-ATPase subunit Rpt5. The PDZ domain of Nas2 binds to the C-terminal tail of Rpt5; however, it does not require the C-terminus of Rpt5 for binding. Here, the 1.15 Å resolution structure of the PDZ domain of Nas2 is reported. This structure will provide a basis for further insights regarding the structure and function of Nas2 in proteasome assembly. PMID:24699731

  3. 5'-coding sequence of the nasA gene of Azotobacter vinelandii is required for efficient expression.

    PubMed

    Wang, Baomin; Wang, Yumei; Kennedy, Christina

    2014-10-01

    The operon nasACBH in Azotobacter vinelandii encodes nitrate and nitrite reductases that sequentially reduce nitrate to nitrite and to ammonium for nitrogen assimilation into organic molecules. Our previous analyses showed that nasACBH expression is subject to antitermination regulation that occurs upstream of the nasA gene in response to the availability of nitrate and nitrite. In this study, we continued expression analyses of the nasA gene and observed that the nasA 5'-coding sequence plays an important role in gene expression, as demonstrated by the fact that deletions caused over sixfold reduction in the expression of the lacZ reporter gene. Further analysis suggests that the nasA 5'-coding sequence promotes gene expression in a way that is not associated with weakened transcript folding around the translational initiation region or codon usage bias. The findings from this study imply that there exists potential to improve gene expression in A. vinelandii by optimizing 5'-coding sequences.

  4. Improved container electrode coatings for Na/S battery systems. Final report

    SciTech Connect

    Hunt, T.K.

    1995-08-01

    Current sodium sulfur (Na/S) battery systems utilize the fast ion conducting properties of sodium beta{double_prime}-alumina electrolyte (BASE) to create high energy density sodium-sulfur electrochemical cells which can be used as components of secondary batteries. Since the days when these cells were invented at the Ford Motor Company Scientific Laboratory by J.T. Kummer and N. Weber, problems with container electrode corrosion have troubled the Na/S systems that have been developed in the many laboratories. In an unpublished investigation carried out at the Ford Motor Company laboratory, it was shown that titanium nitride films sputter deposited onto aluminum substrates under the appropriate conditions can exhibit excellent resistance to corrosion by sodium polysulfide melts. In the work carried out here, the corrosion resistant properties of TiN coatings sputter deposited on Al substrates have been investigated. TiN sputter coated aluminum samples were tested under static conditions in sodium sulfide melts and in Na/S cells under the range of electrochemical conditions needed for battery operation. The sputter deposited coatings produced in these experiments exhibited satisfactory corrosion resistance in the static tests but degraded under full cell operation. Tests of TiN coatings deposited by reactive ion-plating (IP), a common commercial process, showed excellent corrosion and electrical performance in both static and complete cell testing. Charge/discharge testing of sulfur core cells with IP coatings for over 350 cycles to 70 % depth of discharge has shown only very minor changes in cell performance and the tests are continuing.

  5. 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.

  6. 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.

  7. 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.

  8. High power frequency doubled GaInNAs semiconductor disk laser emitting at 615 nm.

    PubMed

    Härkönen, Antti; Rautiainen, Jussi; Guina, Mircea; Konttinen, Janne; Tuomisto, Pietari; Orsila, Lasse; Pessa, Markus; Okhotnikov, Oleg G

    2007-03-19

    We report on an optically-pumped intracavity frequency doubled GaInNAs/GaAs -based semiconductor disk laser emitting around 615 nm. The laser operates at fundamental wavelength of 1230 nm and incorporates a BBO crystal for light conversion to the red wavelength. Maximum output power of 172 mW at 615 nm was achieved from a single output. Combined power from two outputs was 320 mW. The wavelength of visible emission could be tuned by 4.5 nm using a thin glass etalon inside the cavity.

  9. 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.

  10. Two-Color Photoexcitation in a GaNAs/AlGaAs Quantum Well Solar Cell

    NASA Astrophysics Data System (ADS)

    Elborg, Martin; Jo, Masafumi; Ding, Yi; Noda, Takeshi; Mano, Takaaki; Sakoda, Kazuaki

    2012-06-01

    We demonstrate an efficient two-color photoexcitation process in a GaNAs/AlGaAs multiple quantum well (MQW) solar cell. The introduction of N into the GaAs MQW induces a marked reduction in bandgap energy, forming a large conduction band offset, and the formation of localized states. Owning to this deep confinement, the thermal escape of photogenerated carriers from the QWs is greatly suppressed even at room temperature, resulting in a reduction in photocurrent. An additional photocurrent is generated by a two-color absorption process of sub-bandgap photons.

  11. 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

  12. 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.

  13. 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.

  14. InGaN/Dilute-As GaNAs Interface Quantum Well for Red Emitters.

    PubMed

    Tan, Chee-Keong; Borovac, Damir; Sun, Wei; Tansu, Nelson

    2016-01-01

    The design of InGaN/dilute-As GaNAs interface quantum well (QW) leads to significant redshift in the transition wavelength with improvement in electron-hole wave function overlap and spontaneous emission rate as compared to that of the conventional In0.2Ga0.8N QW. By using self-consistent six-band k·p band formalism, the nitride active region consisting of 30 Å In0.2Ga0.8N and 10 Å GaN0.95As0.05 interface QW leads to 623.52 nm emission wavelength in the red spectral regime. The utilization of 30 Å In0.2Ga0.8N/10 Å GaN0.95As0.05 interface QW also leads to 8.5 times enhancement of spontaneous emission rate attributed by the improvement in electron-hole wavefunction overlap, as compared to that of conventional 30 Å In0.35Ga0.65N QW for red spectral regime. In addition, the transition wavelength of the interface QW is relatively unaffected by the thickness of the dilute-As GaNAs interface layer (beyond 10 Å). The analysis indicates the potential of using interface QW concept in nitride-based light-emitting diodes for long wavelength emission. PMID:26758552

  15. InGaN/Dilute-As GaNAs Interface Quantum Well for Red Emitters

    PubMed Central

    Tan, Chee-Keong; Borovac, Damir; Sun, Wei; Tansu, Nelson

    2016-01-01

    The design of InGaN/dilute-As GaNAs interface quantum well (QW) leads to significant redshift in the transition wavelength with improvement in electron-hole wave function overlap and spontaneous emission rate as compared to that of the conventional In0.2Ga0.8N QW. By using self-consistent six-band k·p band formalism, the nitride active region consisting of 30 Å In0.2Ga0.8N and 10 Å GaN0.95As0.05 interface QW leads to 623.52 nm emission wavelength in the red spectral regime. The utilization of 30 Å In0.2Ga0.8N/10 Å GaN0.95As0.05 interface QW also leads to 8.5 times enhancement of spontaneous emission rate attributed by the improvement in electron-hole wavefunction overlap, as compared to that of conventional 30 Å In0.35Ga0.65N QW for red spectral regime. In addition, the transition wavelength of the interface QW is relatively unaffected by the thickness of the dilute-As GaNAs interface layer (beyond 10 Å). The analysis indicates the potential of using interface QW concept in nitride-based light-emitting diodes for long wavelength emission. PMID:26758552

  16. Aeronautics Research Mission Directorate Integrated Systems Research Program (ISRP) and UAS Integration in the NAS Project

    NASA Technical Reports Server (NTRS)

    Wolfe, Jean

    2010-01-01

    Program Goal: Conduct research at an integrated system-level on promising concepts and technologies and explore, assess, or demonstrate the benefits in a relevant environment.Criteria for selection of projects for Integrated Systems Research: a) Technology has attained enough maturity in the foundational research program that they merit more in-depth evaluation at an integrated system level in a relevant environment. b) Technologies which systems analysis indicates have the most potential for contributing to the simultaneous attainment of goals. c) Technologies identified through stakeholder input as having potential for simultaneous attainment of goals. d) Research not being done by other government agencies and appropriate for NASA to conduct. e) Budget augmentation. Environmentally Responsible Aviation (ERA) Project Explore and assess new vehicle concepts and enabling technologies through system-level experimentation to simultaneously reduce fuel burn, noise, and emissions Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project Contribute capabilities that reduce technical barriers related to the safety and operational challenges associated with enabling routine UAS access to the NAS Innovative Concepts for Green Aviation (ICGA) Project Spur innovation by offering research opportunities to the broader aeronautics community through peer-reviewed proposals, with a focus on making aviation more eco-friendly. Establish incentive prizes similar to the Centennial Challenges and sponsor innovation demonstrations of selected technologies that show promise of reducing aviation s impact on the environment

  17. 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.

  18. Comparison of 250 MHz R10K Origin 2000 and 400 MHz Origin 2000 Using NAS Parallel Benchmarks

    NASA Technical Reports Server (NTRS)

    Turney, Raymond D.; Thigpen, William W. (Technical Monitor)

    2001-01-01

    This report describes results of benchmark tests on Steger, a 250 MHz Origin 2000 system with R10K processors, currently installed at the NASA Ames National Advanced Supercomputing (NAS) facility. For comparison purposes, the tests were also run on Lomax, a 400 MHz 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 measure system performance. 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 versions used were PBN3b2, a beta version that is in the process of being released. NPB 2.3 and PBN3b2 are technically different benchmarks, and NPB results are not directly comparable to PBN results.

  19. 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

  20. 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

  1. Serious Gaming for Test & Evaluation of Clean-Slate (Ab Initio) National Airspace System (NAS) Designs

    NASA Technical Reports Server (NTRS)

    Allen, B. Danette; Alexandrov, Natalia

    2016-01-01

    Incremental approaches to air transportation system development inherit current architectural constraints, which, in turn, place hard bounds on system capacity, efficiency of performance, and complexity. To enable airspace operations of the future, a clean-slate (ab initio) airspace design(s) must be considered. This ab initio National Airspace System (NAS) must be capable of accommodating increased traffic density, a broader diversity of aircraft, and on-demand mobility. System and subsystem designs should scale to accommodate the inevitable demand for airspace services that include large numbers of autonomous Unmanned Aerial Vehicles and a paradigm shift in general aviation (e.g., personal air vehicles) in addition to more traditional aerial vehicles such as commercial jetliners and weather balloons. The complex and adaptive nature of ab initio designs for the future NAS requires new approaches to validation, adding a significant physical experimentation component to analytical and simulation tools. In addition to software modeling and simulation, the ability to exercise system solutions in a flight environment will be an essential aspect of validation. The NASA Langley Research Center (LaRC) Autonomy Incubator seeks to develop a flight simulation infrastructure for ab initio modeling and simulation that assumes no specific NAS architecture and models vehicle-to-vehicle behavior to examine interactions and emergent behaviors among hundreds of intelligent aerial agents exhibiting collaborative, cooperative, coordinative, selfish, and malicious behaviors. The air transportation system of the future will be a complex adaptive system (CAS) characterized by complex and sometimes unpredictable (or unpredicted) behaviors that result from temporal and spatial interactions among large numbers of participants. A CAS not only evolves with a changing environment and adapts to it, it is closely coupled to all systems that constitute the environment. Thus, the ecosystem that

  2. 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.

  3. Efficient GaInNAs Gain Mirrors for Semiconductor Disk Lasers at 1.18 {mu}m and 1.22 {mu}m

    SciTech Connect

    Korpijaervi, Ville-Markus; Puustinen, Janne; Leinonen, Tomi; Rautiainen, Jussi; Haerkoenen, Antti; Hakkarainen, Teemu; Guina, Mircea

    2010-11-10

    We report two GaInNAs/GaAs semiconductor disk lasers emitting at the wavelengths of 1180 nm and 1220 nm. The lasers generated 5 W and 7 W output powers, respectively, at a mount temperature of 15 deg. C. Both the gain mirrors were grown by molecular beam epitaxy and consisted of a GaAs/AlAs distributed Bragg reflector and an active region with 10 GaInNAs/GaNAs/GaAs QWs.

  4. NasT-Mediated Antitermination Plays an Essential Role in the Regulation of the Assimilatory Nitrate Reductase Operon in Azotobacter vinelandii

    PubMed Central

    Pierson, Leland S.; Rensing, Christopher; Gunatilaka, Malkanthi K.; Kennedy, Christina

    2012-01-01

    Azotobacter vinelandii is a well-studied model system for nitrogen fixation in bacteria. Regulation of nitrogen fixation in A. vinelandii is independent of NtrB/NtrC, a conserved nitrogen regulatory system in proteobacteria. Previous work showed that an ntrC mutation in A. vinelandii resulted in a loss of induction of assimilatory nitrate and nitrite reductases encoded by the nasAB operon. In addition to NtrC, several other proteins, including NasT, a protein containing a potential RNA-binding domain ANTAR (AmiR and NasR transcription antitermination regulators), have been implicated in nasAB regulation. In this work, we characterize the sequence upstream of nasA and identify several DNA sequence elements, including two potential NtrC binding sites and a putative intrinsic transcriptional terminator upstream of nasA that are potentially involved in nasAB regulation. Our analyses confirm that the nasAB promoter, PnasA, is under NtrC control. However, unlike NtrC-regulated promoters in enteric bacteria, PnasA shows high activity in the presence of ammonium; in addition, the PnasA activity is altered in the nifA gene mutation background. We discuss the implication of these results on NtrC-mediated regulation in A. vinelandii. Our study provides direct evidence that induction of nasAB is regulated by NasT-mediated antitermination, which occurs within the leader region of the operon. The results also support the hypothesis that NasT binds the promoter proximal hairpin of nasAB for its regulatory function, which contributes to the understanding of the regulatory mechanism of ANTAR-containing antiterminators. PMID:22773651

  5. Security Risk Assessment Process for UAS in the NAS CNPC Architecture

    NASA Technical Reports Server (NTRS)

    Iannicca, Dennis Christopher; Young, Daniel Paul; Suresh, Thadhani; Winter, Gilbert A.

    2013-01-01

    This informational paper discusses the risk assessment process conducted to analyze Control and Non-Payload Communications (CNPC) architectures for integrating civil Unmanned Aircraft Systems (UAS) into the National Airspace System (NAS). The assessment employs the National Institute of Standards and Technology (NIST) Risk Management framework to identify threats, vulnerabilities, and risks to these architectures and recommends corresponding mitigating security controls. This process builds upon earlier work performed by RTCA Special Committee (SC) 203 and the Federal Aviation Administration (FAA) to roadmap the risk assessment methodology and to identify categories of information security risks that pose a significant impact to aeronautical communications systems. A description of the deviations from the typical process is described in regards to this aeronautical communications system. Due to the sensitive nature of the information, data resulting from the risk assessment pertaining to threats, vulnerabilities, and risks is beyond the scope of this paper

  6. Security Risk Assessment Process for UAS in the NAS CNPC Architecture

    NASA Technical Reports Server (NTRS)

    Iannicca, Dennis C.; Young, Dennis P.; Thadani, Suresh K.; Winter, Gilbert A.

    2013-01-01

    This informational paper discusses the risk assessment process conducted to analyze Control and Non-Payload Communications (CNPC) architectures for integrating civil Unmanned Aircraft Systems (UAS) into the National Airspace System (NAS). The assessment employs the National Institute of Standards and Technology (NIST) Risk Management framework to identify threats, vulnerabilities, and risks to these architectures and recommends corresponding mitigating security controls. This process builds upon earlier work performed by RTCA Special Committee (SC) 203 and the Federal Aviation Administration (FAA) to roadmap the risk assessment methodology and to identify categories of information security risks that pose a significant impact to aeronautical communications systems. A description of the deviations from the typical process is described in regards to this aeronautical communications system. Due to the sensitive nature of the information, data resulting from the risk assessment pertaining to threats, vulnerabilities, and risks is beyond the scope of this paper.

  7. Deep-level study of Ga(In)P(NAs) alloys grown on Si substrates

    NASA Astrophysics Data System (ADS)

    Baranov, A. I.; Kleider, J. P.; Gudovskikh, A. S.; Darga, A.; Nikitina, E. V.; Egorov, A. Yu

    2016-08-01

    Defect properties of Ga(In)P(NAs) layers with different composition were studied by admittance spectroscopy. For nitrogen content layers the defect level with energy of 0.44-0.47 eV, which related to nitrogen incorporation into GaP, was observed. Its concentration is lower for GaPNAs layers compared to GaPN/InP due to better compensation by arsenic than by indium in lattice of GaP. Other defect level with energy of 0.30 eV was detected in GaPAs and GaPN/InP layers. Likely, the both observed defects in GaPAs and GaPN/InP have the same nature.

  8. Temperature coefficients for GaInP/GaAs/GaInNAsSb solar cells

    SciTech Connect

    Aho, Arto; Isoaho, Riku; Tukiainen, Antti; Polojärvi, Ville; Aho, Timo; Raappana, Marianna; Guina, Mircea

    2015-09-28

    We report the temperature coefficients for MBE-grown GaInP/GaAs/GaInNAsSb multijunction solar cells and the corresponding single junction sub-cells. Temperature-dependent current-voltage measurements were carried out using a solar simulator equipped with a 1000 W Xenon lamp and a three-band AM1.5D simulator. The triple-junction cell exhibited an efficiency of 31% at AM1.5G illumination and an efficiency of 37–39% at 70x real sun concentration. The external quantum efficiency was also measured at different temperatures. The temperature coefficients up to 80°C, for the open circuit voltage, the short circuit current density, and the conversion efficiency were determined to be −7.5 mV/°C, 0.040 mA/cm{sup 2}/°C, and −0.09%/°C, respectively.

  9. Development of computer program NAS3D using Vector processing for geometric nonlinear analysis of structures

    NASA Technical Reports Server (NTRS)

    Mangalgiri, P. D.; Prabhakaran, R.

    1986-01-01

    An algorithm for vectorized computation of stiffness matrices of an 8 noded isoparametric hexahedron element for geometric nonlinear analysis was developed. This was used in conjunction with the earlier 2-D program GAMNAS to develop the new program NAS3D for geometric nonlinear analysis. A conventional, modified Newton-Raphson process is used for the nonlinear analysis. New schemes for the computation of stiffness and strain energy release rates is presented. The organization the program is explained and some results on four sample problems are given. The study of CPU times showed that savings by a factor of 11 to 13 were achieved when vectorized computation was used for the stiffness instead of the conventional scalar one. Finally, the scheme of inputting data is explained.

  10. The conjugate gradient NAS parallel benchmark on the IBM SP1

    SciTech Connect

    Trefethen, A.E.; Zhang, T.

    1994-12-31

    The NAS Parallel Benchmarks are a suite of eight benchmark problems developed at the NASA Ames Research Center. They are specified in such a way that the benchmarkers are free to choose the language and method of implementation to suit the system in which they are interested. In this presentation the authors will discuss the Conjugate Gradient benchmark and its implementation on the IBM SP1. The SP1 is a parallel system which is comprised of RS/6000 nodes connected by a high performance switch. They will compare the results of the SP1 implementation with those reported for other machines. At this time, such a comparison shows the SP1 to be very competitive.

  11. Seismic reflection exploration of geothermal reservoir at Naval Air Station (NAS) Fallon, Nevada

    NASA Astrophysics Data System (ADS)

    Alay G., Gebregiorgis

    The Primary objective of this study is to increase geologic and tectonic understanding of the geothermal resources at the Naval Air Station (NAS) Fallon, Nevada. The seismic reflection method is employed to study faults, fractures and other tectonic structures in the subsurface in order to identify geothermal drill targets. The efficiency of geothermal systems is strongly dependent on water circulation. Discrete faults may be permeable and provide pathways for water flow depending on the fracture density. It is therefore desirable to detect and map faults and fracture zones and characterize their physical properties when evaluating a geothermal prospect. The seismic data for this project were provided by the NAS environmental research program in Ridgecrest, CA. However, the data collection information was not available so the work includes determining the line geometry and mapping shot points to field files in order to process the data. ProMAX 2D(TM) is the software used to determine the geometry and to process the data. Data processing includes eliminating noise, datum and refraction statics, trace muting, bandpass filter, automatic gain control, amplitude recovery, CMP sorting, velocity analysis and NMO correction, stacking and migration. The results of this study indicate the presence of thick basin fill including Tertiary and Quaternary sediments underlain by Tertiary basalts which are interpreted to be capping rocks for the geothermal reservoirs. This seismic reflection study also reveals the presence of strongly fractured pre-Tertiary basement complex with their top at about 1500m on the north and west and about 900 m on the eastern and southern part of the study area.

  12. The use of net analyte signal (NAS) in near infrared spectroscopy pharmaceutical applications: interpretability and figures of merit.

    PubMed

    Sarraguça, Mafalda Cruz; Lopes, João Almeida

    2009-05-29

    Near infrared spectroscopy (NIRS) has been extensively used as an analytical method for quality control of solid dosage forms for the pharmaceutical industry. Pharmaceutical formulations can be extremely complex, containing typically one or more active product ingredients (API) and various excipients, yielding very complex near infrared (NIR) spectra. The NIR spectra interpretability can be improved using the concept of net analyte signal (NAS). NAS is defined as the part of the spectrum unique to the analyte of interest. The objective of this work was to compare two different methods to estimate the API's NAS vector of different pharmaceutical formulations. The main difference between the methods is the knowledge of API free formulations NIR spectra. The comparison between the two methods was assessed in a qualitative and quantitative way. Results showed that both methods produced good results in terms of the similarity between the NAS vector and the pure API spectrum, as well as in the ability to predict the API concentration of unknown samples. Moreover, figures of merit such as sensitivity, selectivity, and limit of detection were estimated in a straightforward manner.

  13. Right and Wrong and Cultural Diversity: Replication of the 2002 NAS/Zogby Poll on Business Ethics

    ERIC Educational Resources Information Center

    Ludlum, Marty; Mascaloinov, Sergei

    2004-01-01

    In April 2002, a NAS/Zogby poll found that only a quarter of sampled students perceived uniform standards of "right and wrong" and that most students felt that ethical behavior depends on cultural diversity. In this effort to replicate those findings in a larger sample of American college students, the authors obtained results that contradict the…

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

    SciTech Connect

    Gladysiewicz, M.; Wartak, M. S.; Kudrawiec, R.

    2014-01-21

    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% 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.

  15. EPA'S REANALYSIS OF KEY ISSUES RELATED TO DIOXIN TOXICITY AND RESPONSE TO NAS COMMENTS (VOLUME 1) (INTERAGENCY SCIENCE DISCUSSION DRAFT)

    EPA Science Inventory

    EPA is releasing the draft report, EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments (Volume 1), that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments (External Review Draft)

    EPA Science Inventory

  1. Direct visualization of the N impurity state in dilute GaNAs using scanning tunneling microscopy

    NASA Astrophysics Data System (ADS)

    Ishida, Nobuyuki; Jo, Masafumi; Mano, Takaaki; Sakuma, Yoshiki; Noda, Takeshi; Fujita, Daisuke

    2015-10-01

    The interaction between nitrogen (N) impurity states in III-V compounds plays a key role in controlling optoelectronic properties of the host materials. Here, we use scanning tunneling microscopy to characterize the spatial distribution and electronic properties of N impurity states in dilute GaNAs. We demonstrated that the N impurity states can be directly visualized by taking empty state current images using the multipass scanning method. The N impurity states broadened over several nanometers and exhibited a highly anisotropic distribution with a bowtie-like shape on the GaAs(110) surface, which can be explained by anisotropic propagation of strain along the zigzag chains of Ga and As atoms in the {110} plane. Our experimental findings provide strong insights into a possible role of N impurity states in modifying properties of the host materials.The interaction between nitrogen (N) impurity states in III-V compounds plays a key role in controlling optoelectronic properties of the host materials. Here, we use scanning tunneling microscopy to characterize the spatial distribution and electronic properties of N impurity states in dilute GaNAs. We demonstrated that the N impurity states can be directly visualized by taking empty state current images using the multipass scanning method. The N impurity states broadened over several nanometers and exhibited a highly anisotropic distribution with a bowtie-like shape on the GaAs(110) surface, which can be explained by anisotropic propagation of strain along the zigzag chains of Ga and As atoms in the {110} plane. Our experimental findings provide strong insights into a possible role of N impurity states in modifying properties of the host materials. Electronic supplementary information (ESI) available: Identification of N impurity positions in terms of depth of depressions in the filled state topographic image. Filled state topographic images of N impurity in the fourth plane. Slight modification of topographic height

  2. Photoluminescence study of Be acceptors in GaInNAs epilayers

    NASA Astrophysics Data System (ADS)

    Tsai, Y.; Barman, B.; Scrace, T.; Petrou, A.; Fukuda, M.; Sellers, I. R.; Leroux, M.; Khalfioui, M. A.

    2014-03-01

    We have studied the photoluminescence (PL) spectra from MBE grown GaInNAs epilayers doped p-type with Beryllium acceptors. The measurements were carried out in the 5 K - 70 K temperature range and in magnetic fields (B) up to 7 tesla. The PL spectra contain two features at T = 5 K: The exciton at 1093 meV and a second broader feature at 1058 meV. The intensity of this feature decreases with increasing temperature and disappears completely by 70K while the excitonic feature persists. The emission at 1058meV is identified as the conduction band to Beryllium acceptor transition. If we take into account the binding energy of the exciton [3] we get a value of 23 meV for the Beryllium acceptor binding energy. The acceptor related transition was studied as a function of magnetic field; the energy of this transition has a linear dependence on B with a slope of 055 meV/T. Research supported by Amethyst Research In. through the State of Oklahoma, ONAP program.

  3. 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.

  4. 1-eV GaInNAs solar cells for ultrahigh-frequency multijunction devices

    SciTech Connect

    Friedman, D.J.; Geisz, J.F.; Kurtz, S.R.; Olson, J.M.

    1998-09-01

    The authors demonstrate working prototypes of a GaInNAs-based solar cell lattice-matched to GaAs with photoresponse down to 1 eV. This device is intended for use as the third junction of future-generation ultrahigh-efficiency three- and four-junction devices. Under the AM1.5 direct spectrum with all the light higher in energy than the GaAs band gap filtered out, the prototypes have open-circuit voltages ranging from 0.35 to 0.44 V, short-circuit currents of 1.8 mA/cm{sup 2}, and fill factors from 61--66%. The short-circuit currents are of principal concern: the internal quantum efficiencies rise only to about 0.2. The authors discuss the short diffusion lengths which are the reason for this low photocurrent. As a partial workaround for the poor diffusion lengths, they demonstrate a depletion-width-enhanced variation of one of the prototype devices that grades off decreased voltage for increased photocurrent, with a short-circuit current of 6.5 mA/cm{sup 2} and an open-circuit voltage of 0.29 V.

  5. 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.

  6. 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

  7. 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.

  8. Nitrogen-concentration control in GaNAs/AlGaAs quantum wells using nitrogen δ-doping technique

    SciTech Connect

    Mano, Takaaki; Jo, Masafumi; Kuroda, Takashi; Noda, Takeshi; Sugimoto, Yoshimasa; Sakuma, Yoshiki; Elborg, Martin; Sakoda, Kazuaki

    2014-05-15

    GaNAs/Al{sub 0.35}Ga{sub 0.65}As multiple quantum wells (MQWs) with nitrogen δ-doping were fabricated on GaAs (100) substrates by plasma-assisted molecular beam epitaxy. High controllability of nitrogen-concentrations in the MQWs was achieved by tuning nitrogen δ-doping time. The maximum nitrogen concentration in the MQWs was 2.8%. The MQWs exhibit intense, narrow photoluminescence emission.

  9. 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.

  10. Influence of growth temperature and disorder on spectral and temporal properties of Ga(NAsP) heterostructures

    NASA Astrophysics Data System (ADS)

    Woscholski, R.; Gies, S.; Wiemer, M.; Shakfa, M. K.; Rahimi-Iman, A.; Ludewig, P.; Reinhard, S.; Jandieri, K.; Baranovskii, S. D.; Heimbrodt, W.; Volz, K.; Stolz, W.; Koch, M.

    2016-04-01

    We have studied the optical properties of Ga(NAsP)-heterostructures, which were systematically grown at different temperatures by means of continuous-wave and time-resolved photoluminescence. We show that both the long ranged and the short ranged disorder scales increase for higher growth temperatures. Furthermore, samples with a higher disorder not only emit less photoluminescence (PL) intensity but also exhibit a longer effective PL decay time.

  11. Electronic band structure calculation of GaNAsBi alloys and effective mass study

    NASA Astrophysics Data System (ADS)

    Habchi, M. M.; Ben Nasr, A.; Rebey, A.; El Jani, B.

    2013-11-01

    Electronic band structures of GaNxAs1-x-yBiy dilute nitrides-bismides have been determined theoretically within the framework of the band anticrossing (BAC) model and k ṡ p method. We have developed computer codes based on our extended BAC model, denoted (16 × 16), in which the dimension of the used states basis was equal to 16. We have investigated the band gap and the spin orbit splitting as a function of Bi composition for alloys lattice matched to GaAs. We have found that the substitution of As element by N and Bi impurities leads to a significant reduction of band gap energy by roughly 198 meV/%Bi. Meanwhile, spin orbit splitting increases by 56 meV/%Bi regardless N content. There is an excellent agreement between the model predictions and experiment reported in the literature. In addition, alloys compositions and oscillator strengths of transition energies have been calculated for GaNAsBi alloys which represent active zone of temperature insensitive (1.55 μm and 1.3 μm) wavelength laser diodes intended for optical fiber communications. A crossover at about 0.6 eV has occurred between Eg and Δso of GaN.039As.893Bi.068. When the quaternary is lattice mismatched to GaAs, resonance energy increases with Bi content if N content decreases. On the other hand, effective mass behavior of carriers at Γ point has been discussed with respect to alloy composition, k-directions and lattice mismatch.

  12. Suppression of non-radiative surface recombination by N incorporation in GaAs/GaNAs core/shell nanowires

    PubMed Central

    Chen, Shula L.; Chen, Weimin M.; Ishikawa, Fumitaro; Buyanova, Irina A.

    2015-01-01

    III-V semiconductor nanowires (NWs) such as GaAs NWs form an interesting artificial materials system promising for applications in advanced optoelectronic and photonic devices, thanks to the advantages offered by the 1D architecture and the possibility to combine it with the main-stream silicon technology. Alloying of GaAs with nitrogen can further enhance performance and extend device functionality via band-structure and lattice engineering. However, due to a large surface-to-volume ratio, III-V NWs suffer from severe non-radiative carrier recombination at/near NWs surfaces that significantly degrades optical quality. Here we show that increasing nitrogen composition in novel GaAs/GaNAs core/shell NWs can strongly suppress the detrimental surface recombination. This conclusion is based on our experimental finding that lifetimes of photo-generated free excitons and free carriers increase with increasing N composition, as revealed from our time-resolved photoluminescence (PL) studies. This is accompanied by a sizable enhancement in the PL intensity of the GaAs/GaNAs core/shell NWs at room temperature. The observed N-induced suppression of the surface recombination is concluded to be a result of an N-induced modification of the surface states that are responsible for the nonradiative recombination. Our results, therefore, demonstrate the great potential of incorporating GaNAs in III-V NWs to achieve efficient nano-scale light emitters. PMID:26100755

  13. 1.55 {mu}m GaAs/GaNAsSb/GaAs optical waveguides grown by radio frequency nitrogen plasma-assisted molecular beam epitaxy

    SciTech Connect

    Tan, K. H.; Yoon, S. F.; Loke, W. K.; Wicaksono, S.; Xu, Z.; Ng, T. K.; Lew, K. L.; Saadsaoud, N.; Zegaoui, M.; Decoster, D.; Chazelas, J.

    2008-03-17

    We demonstrate a 1.55 {mu}m GaAs/GaNAsSb/GaAs optical waveguide grown by molecular beam epitaxy as an alternative to the AlGaAs/GaAs system. The 0.4-{mu}m-thick GaNAsSb guiding layer contains {approx}3.5% of N and 9% of Sb, resulting in optical band gap of 0.88 eV. The refractive index of the GaNAsSb layer was measured from 800 to 1700 nm. The GaNAsSb layer has a refractive index value of 3.42 at 1.55 {mu}m wavelength. The propagation loss measured using the Fabry-Perot resonance method was found to be affected by nitrogen-related defect absorption.

  14. Física e Arte nas Estações do Ano

    NASA Astrophysics Data System (ADS)

    Pessôa Queiroz, Glória; da Conceição Barbosa Lima, Maria; Navarro Vasconcellos das Mercês, Maria

    2004-12-01

    The paper deals with the subject of the Four Seasons, exploring elements of Science and the Art in order to motivate students or public of museums of science and technology to understand it from their current cultural experiences and of old times. Physics joins to Astronomy to explain the phenomenon, while the use of Music and Painting make possible the immersion in the subject in way to many trips to the imagination capable to awake emotions.A proposal didactic is presented and justified for some consensus of the research in the area of teaching-learning of science, since that related to the persistent alternative conceptions concerning the causes of the changes observed at the different times of the year until the qualitative modelling of phenomena that appeals three-dimensional pedagogical models. Such proposal was developed in the activity named " Hiper interesting Talk: The Four Seasons, Science and Art" in the first Sunday of August/2003 in the Museum of Astronomy, MAST. O artigo trata do tema das Estações do Ano, explorando elementos da Ciência e da Arte como forma de motivar estudantes ou público de museus de ciência e tecnologia a compreendê-lo a partir de vivências culturais atuais e de outras épocas. A Física se junta à Astronomia para explicar o fenômeno, enquanto a Música e a Pintura possibilitam a imersão no tema em meio a muitas viagens à imaginação capazes de despertar emoções.Uma proposta didática é apresentada e justificada por consensos das muitas pesquisas na área de ensino-aprendizagem de ciências, desde os que se referem às persistentes concepções alternativas acerca das causas das mudanças observadas nas diferentes épocas do ano até à modelagem qualitativa de fenômenos que recorre a modelos pedagógicos tridimensionais. Tal proposta foi desenvolvida na atividade "Bate papo Hiperinteressante: As Quatro Estações, Ciência e Arte" realizada no primeiro domingo do mês de agosto de 2003 no Museu de Astronomia.

  15. Remotely Operated Aircraft (ROA) Impact on the National Airspace System (NAS) Work Package: Data Modeling and Sharing Perspective for Development of a Common Operating Picture

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This report documents analyses that were performed in support of Task #3 of Work Package #3 (WP3), ROA Impact on the NAS. The purpose of the overall work package was to determine if there are any serious issues that would prevent or prohibit ROA's flying in the NAS on a routine basis, and if so, what actions should be taken to address them. The purpose of Task #3 was to look at this problem from the perspective of data modeling and sharing.

  16. Incorporating the social dimension into hydrogeochemical investigations for rural development: the Bir Al-Nas approach for socio-hydrogeology

    NASA Astrophysics Data System (ADS)

    Re, Viviana

    2015-11-01

    A replicable multidisciplinary approach is presented for science-based groundwater management practices: Bir Al-Nas (Bottom-up IntegRated Approach for sustainabLe grouNdwater mAnagement in rural areaS). This approach provides a practical example of the concept of "socio-hydrogeology", a way of incorporating the social dimension into hydrogeological investigations, as reinforced by the translation of the Arabic bir al-nas: "the people's well". To achieve this, hydrogeologists act as "social hydrologists" during their monitoring activities, which often bring them into contact with local communities and end users (and polluters) of water. Not only can they retrieve reliable information about traditional know-how and local issues, but they can also change the public perception of science/scientists to create the basis for mutual collaboration and understanding in view of implementing improved integrated groundwater management. The final outcomes are expected to be an increased awareness of communities at the local level and a clear understanding of their water issues and needs from the very early stages of the investigation. Although the importance of using such methods in groundwater analysis and management is widely recognized, hydrogeological investigations are currently dominated by sectorial approaches that are easier to implement but less sustainable. The pressure of population growth, the shift towards more water-dependent economies, climate change and its impact on water availability will require scientists to use a more integrated approach, such as Bir Al-Nas, when dealing with increasing water pollution and water-scarcity issues.

  17. The CSM testbed software system: A development environment for structural analysis methods on the NAS CRAY-2

    NASA Technical Reports Server (NTRS)

    Gillian, Ronnie E.; Lotts, Christine G.

    1988-01-01

    The Computational Structural Mechanics (CSM) Activity at Langley Research Center is developing methods for structural analysis on modern computers. To facilitate that research effort, an applications development environment has been constructed to insulate the researcher from the many computer operating systems of a widely distributed computer network. The CSM Testbed development system was ported to the Numerical Aerodynamic Simulator (NAS) Cray-2, at the Ames Research Center, to provide a high end computational capability. This paper describes the implementation experiences, the resulting capability, and the future directions for the Testbed on supercomputers.

  18. UAS Integration into the NAS: Detect and Avoid Display Evaluations in Support of SC-228 MOPS Development

    NASA Technical Reports Server (NTRS)

    Fern, Lisa; Rorie, Conrad; Shively, Jay

    2015-01-01

    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 Integration into the NAS project. Much of the work has been used to support the ongoing development of minimum operational performance standards (MOPS) for UAS by RTCA Special Committee 228. The design and results of three different human-in-the-loop simulations are discussed, with particular emphasis on the role of the UAS pilot in the Self Separation Timeline.

  19. 1.55 {mu}m GaInNAs resonant-cavity-enhanced photodetector grown on GaAs

    SciTech Connect

    Han, Q.; Yang, X.H.; Niu, Z.C.; Ni, H.Q.; Xu, Y.Q.; Zhang, S.Y.; Du, Y.; Peng, L.H.; Zhao, H.; Tong, C.Z.; Wu, R.H.; Wang, Q.M.

    2005-09-12

    We report the design, growth, fabrication, and characterization of a GaAs-based resonant-cavity-enhanced (RCE) GaInNAs photodetector operating at 1.55 {mu}m. The structure of the device was designed using a transfer-matrix method (TMM). By optimizing the molecular-beam epitaxy growth conditions, six GaInNAs quantum wells were used as the absorption layers. Twenty-five (25)- and 9-pair GaAs/AlAs-distributed Bragg reflectors were grown as the bottom and top mirrors. At 1.55 {mu}m, a quantum efficiency of 33% with a full width at half maximum of 10 nm was obtained. The dark current density was 3x10{sup -7} A/cm{sup 2} at a bias of 0 V and 4.3x10{sup -5} A/cm{sup 2} at a reverse bias of 5 V. The primary time response measurement shows that the device has a rise time of less than 800 ps.

  20. Cohort Profile: The National Academy of Sciences-National Research Council Twin Registry (NAS-NRC Twin Registry)

    PubMed Central

    Gatz, Margaret; Harris, Jennifer R; Kaprio, Jaakko; McGue, Matt; Smith, Nicholas L; Snieder, Harold; Spiro, Avron; Butler, David A

    2015-01-01

    The National Academy of Sciences-National Research Council Twin Registry (NAS-NRC Twin Registry) is a comprehensive registry of White male twin pairs born in the USA between 1917 and 1927, both of the twins having served in the military. The purpose was medical research and ultimately improved clinical care. The cohort was assembled in the early 1960s with identification of approximately 16 000 twin pairs, review of service records, a brief mailed questionnaire assessing zygosity, and a health survey largely comparable to questionnaires used at that time with Scandinavian twin registries. Subsequent large-scale data collection occurred in 1974, 1985 and 1998, repeating the health survey and including information on education, employment history and earnings. Self-reported data have been supplemented with mortality, disability and medical data through record linkage. Potential collaborators should access the study website [http://www.iom.edu/Activities/Veterans/TwinsStudy.aspx] or e-mail the Medical Follow-up Agency at [Twins@nas.edu]. Questionnaire data are being prepared for future archiving with the National Archive of Computerized Data on Aging (NACDA) at the Inter-University Consortium for Political and Social Research (ICPSR), University of Michigan, MI. PMID:25183748

  1. The effect of cathode felt geometries on electrochemical characteristics of sodium sulfur (NaS) cells: Planar vs. tubular

    NASA Astrophysics Data System (ADS)

    Kim, Goun; Park, Yoon-Cheol; Lee, Younki; Cho, Namung; Kim, Chang-Soo; Jung, Keeyoung

    2016-09-01

    Two sodium sulfur (NaS) cells, one with a planar design and the other with a tubular design, were subject to discharge-charge cycles in order to investigate the effect of cathode felt geometries on electrochemical characteristics of NaS cells. Their discharge-charge behaviors over 200 cycles were evaluated at the operation temperature of 350 °C with the current densities of 100 mA cm-2 for discharge and 80 mA cm-2 for charge. The results showed that the deviation from theoretical open circuit voltage changes of a planar cell was smaller than those of a tubular cell resulting in potential specific power loss reduction during operation. In order to understand the effect, a three dimensional statistically representative matrix for a cathode felt has been generated using experimentally measured data. It turns out that the area specific fiber number density in the outer side area of a tubular cathode felt is smaller than that of a planar felt resulting in occurrence of larger voltage drops via retarded convection of cathode melts during cell operation.

  2. TlGaInNAs/GaAs double quantum well structures: Effect of barrier layers and substrate orientation

    NASA Astrophysics Data System (ADS)

    Krishnamurthy, D.; Matsumoto, T.; Fujiwara, A.; Hasegawa, S.; Asahi, H.

    2007-04-01

    The quinary TlGaInNAs-based double quantum well (DQW) structures were grown on GaAs substrates by electron cyclotron resonance (ECR)-MBE and the samples were probed by secondary ion mass spectroscopy (SIMS). Light emitting diodes (LEDs) were fabricated using these DQW wafers and their electroluminescence (EL) behaviors were studied at different temperatures. The effects of different barrier layers and substrate orientations on the amount of Tl incorporation and on the temperature dependency of the EL peak wavelengths of the LEDs were studied. Higher incorporation of Tl into the quantum well (QW) region and the ensuing change in the temperature dependency of the peak wavelengths owing to the TlGaAs barrier layer are reported. GaAs substrates having (3 1 1)B orientation were found to allow more Tl incorporation as compared to (1 0 0) and (3 1 1)A oriented substrates. The LEDs fabricated out of the TlGaInNAs/TlGaAs/(3 1 1)B GaAs DQW structures showed the least temperature dependency of the EL peak wavelengths exemplifying the usefulness of Tl in the QW as well as barrier region.

  3. Cohort Profile: The National Academy of Sciences-National Research Council Twin Registry (NAS-NRC Twin Registry).

    PubMed

    Gatz, Margaret; Harris, Jennifer R; Kaprio, Jaakko; McGue, Matt; Smith, Nicholas L; Snieder, Harold; Spiro, Avron; Butler, David A

    2015-06-01

    The National Academy of Sciences-National Research Council Twin Registry (NAS-NRC Twin Registry) is a comprehensive registry of White male twin pairs born in the USA between 1917 and 1927, both of the twins having served in the military. The purpose was medical research and ultimately improved clinical care. The cohort was assembled in the early 1960s with identification of approximately 16,000 twin pairs, review of service records, a brief mailed questionnaire assessing zygosity, and a health survey largely comparable to questionnaires used at that time with Scandinavian twin registries. Subsequent large-scale data collection occurred in 1974, 1985 and 1998, repeating the health survey and including information on education, employment history and earnings. Self-reported data have been supplemented with mortality, disability and medical data through record linkage. Potential collaborators should access the study website [http://www.iom.edu/Activities/Veterans/TwinsStudy.aspx] or e-mail the Medical Follow-up Agency at [Twins@nas.edu]. Questionnaire data are being prepared for future archiving with the National Archive of Computerized Data on Aging (NACDA) at the Inter-University Consortium for Political and Social Research (ICPSR), University of Michigan, MI. PMID:25183748

  4. 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.

  5. Effects of insertion of strain-engineering Ga(In)NAs layers on optical properties of InAs/GaAs quantum dots for high-efficiency solar cells

    NASA Astrophysics Data System (ADS)

    Pavelescu, Emil-Mihai; Polojärvi, Ville; Schramm, Andreas; Tukiainen, Antti; Aho, Arto; Zhang, Wenxin; Puustinen, Janne; Salmi, Joel; Guina, Mircea

    2016-02-01

    We report study on stacked InAs/GaNAs quantum dots heterostructures with dilute nitride GaInNAs strain mediating layers embedded in GaAs p-i-n solar cell structure. The insertion of GaInNAs strain mediating layers in the vicinity of the strain compensated InAs/GaNAs quantum dots heterostructures enhances their surface density, improves and significantly red shifts their light emission. Embedding a stack of the strain-mediated InAs/GaInNAs/GaNAs quantum dots in the i region of a GaAs p-i-n solar cell leads also to a red shift of the absorption edge of the solar cells and improves the solar cell photogenerated currents at longer wavelengths beyond 1200 nm.

  6. Effects of hydrogenation on non-radiative defects in GaNP and GaNAs alloys: An optically detected magnetic resonance study

    SciTech Connect

    Dagnelund, D.; Chen, W. M.; Buyanova, I. A; Vorona, I. P.; Nosenko, G.; Wang, X. J.; Tu, C. W.; Yonezu, H.; Polimeni, A.; Capizzi, M.

    2012-01-15

    Photoluminescence and optically detected magnetic resonance techniques are utilized to study defect properties of GaNP and GaNAs alloys subjected to post-growth hydrogenation by low-energy sub-threshold ion beam irradiation. It is found that in GaNP H incorporation leads to activation of new defects, which has a Ga interstitial (Ga{sub i}) atom at its core and may also involve a H atom as a partner. The observed activation critically depends on the presence of N in the alloy, as it does not occur in GaP with a low level of N doping. In sharp contrast, in GaNAs hydrogen is found to efficiently passivate Ga{sub i}-related defects present in the as-grown material. A possible mechanism responsible for the observed difference in the H behavior in GaNP and GaNAs is discussed.

  7. High-quality GaNAs/GaAs quantum wells with light emission up to 1.44 {mu}m grown by molecular-beam epitaxy

    SciTech Connect

    Wang, S.M.; Gu, Q.F.; Wei, Y.Q.; Sadeghi, M.; Larsson, A.; Zhao, Q.X.; Wang, X.D.; Ma, C.H.; Xing, Z.G.

    2005-10-03

    High-quality GaNAs/GaAs quantum wells with high substitutional N concentrations, grown by molecular-beam epitaxy, are demonstrated using a reduced growth rate in a range of 0.125-1 {mu}m/h. No phase separation is observed and the GaNAs well thickness is limited by the critical thickness. Strong room-temperature photoluminescence with a record long wavelength of 1.44 {mu}m is obtained from an 18-nm-thick GaN{sub 0.06}As{sub 0.94}/GaAs quantum well.

  8. Incorporation model of N into GaInNAs alloys grown by radio-frequency plasma-assisted molecular beam epitaxy

    SciTech Connect

    Aho, A.; Korpijärvi, V.-M.; Tukiainen, A.; Puustinen, J.; Guina, M.

    2014-12-07

    We present a Maxwell-Boltzmann electron energy distribution based model for the incorporation rate of nitrogen into GaInNAs grown by molecular beam epitaxy (MBE) using a radio frequency plasma source. Nitrogen concentration is predicted as a function of radio-frequency system primary resistance, N flow, and RF power, and group III growth rate. The semi-empirical model is shown to be repeatable with a maximum error of 6%. The model was validated for two different MBE systems by growing GaInNAs on GaAs(100) with variable nitrogen composition of 0%–6%.

  9. Carrier dynamics in Ga(NAsP)/Si multi-quantum well heterostructures with varying well thickness

    NASA Astrophysics Data System (ADS)

    Shakfa, M. K.; Woscholski, R.; Gies, S.; Wegele, T.; Wiemer, M.; Ludewig, P.; Jandieri, K.; Baranovskii, S. D.; Stolz, W.; Volz, K.; Heimbrodt, W.; Koch, M.

    2016-05-01

    Time-resolved photoluminescence (TR-PL) measurements have been performed in Ga(NAsP)/(BGa)(AsP) multi-quantum well heterostructures (MQWHs) with different well thicknesses. The studied structures have been pseudomorphically grown on Si substrates by metal organic vapor phase epitaxy (MOVPE) with an N content of about 7%. Experimental results reveal a shortening in the PL decay time with increasing QW thickness, meanwhile, accompanied by a decrease in the PL intensity. We attribute this behavior to an increasing non-radiative recombination rate for broader QWs which arises from an increasing number of defects in the QW material. The emission-energy distribution of the PL decay time is studied at various temperatures. The PL decay time strongly depends on the emission energy at low temperatures and becomes emission-energy-independent close to room temperature. This is discussed in terms of the carrier localization in the studied structures.

  10. Reactive Microcontact Printing of DNA Probes on (DMA-NAS-MAPS) Copolymer-Coated Substrates for Efficient Hybridization Platforms.

    PubMed

    Castagna, Rossella; Bertucci, Alessandro; Prasetyanto, Eko Adi; Monticelli, Marco; Conca, Dario Valter; Massetti, Matteo; Sharma, Parikshit Pratim; Damin, Francesco; Chiari, Marcella; De Cola, Luisa; Bertacco, Riccardo

    2016-04-01

    High-performing hybridization platforms fabricated by reactive microcontact printing of DNA probes are presented. Multishaped PDMS molds are used to covalently bind oligonucleotides over a functional copolymer (DMA-NAS-MAPS) surface. Printed structures with minimum width of about 1.5 μm, spaced by 10 μm, are demonstrated, with edge corrugation lower than 300 nm. The quantification of the immobilized surface probes via fluorescence imaging gives a remarkable concentration of 3.3 × 10(3) oligonucleotides/μm(2), almost totally active when used as probes in DNA-DNA hybridization assays. Indeed, fluorescence and atomic force microscopy show a 95% efficiency in target binding and uniform DNA hybridization over printed areas. PMID:26972953

  11. 1.22 {mu}m GaInNAs Saturable Absorber Mirrors with Tailored Recovery Time

    SciTech Connect

    Puustinen, Janne; Guina, Mircea; Korpijaervi, Ville-Markus; Tukiainen, Antti; Kivistoe, Samuli; Pessa, Markus; Marcinkevicius, Saulius

    2010-11-10

    The effect of in-situ N-ion irradiation on the recombination dynamics of GaInNAs/GaAs semiconductor saturable absorber mirrors has been studied. The samples were fabricated by molecular beam epitaxy using a radio frequency plasma source for nitrogen incorporation in the absorber layers as well as for the irradiation. The recombination dynamics of irradiated samples were studied by pump-probe measurements. The recombination time of the absorbers could be reduced by increasing the irradiation time. The effect of the reduced recombination time on the pulse dynamics of a mode-locked laser setup was studied with a Bi-doped fibre laser. The pulse quality was found to improve with increased irradiation time and reduced recombination time, demonstrating the potential of the in-situ irradiation method for device applications.

  12. Reactive Microcontact Printing of DNA Probes on (DMA-NAS-MAPS) Copolymer-Coated Substrates for Efficient Hybridization Platforms.

    PubMed

    Castagna, Rossella; Bertucci, Alessandro; Prasetyanto, Eko Adi; Monticelli, Marco; Conca, Dario Valter; Massetti, Matteo; Sharma, Parikshit Pratim; Damin, Francesco; Chiari, Marcella; De Cola, Luisa; Bertacco, Riccardo

    2016-04-01

    High-performing hybridization platforms fabricated by reactive microcontact printing of DNA probes are presented. Multishaped PDMS molds are used to covalently bind oligonucleotides over a functional copolymer (DMA-NAS-MAPS) surface. Printed structures with minimum width of about 1.5 μm, spaced by 10 μm, are demonstrated, with edge corrugation lower than 300 nm. The quantification of the immobilized surface probes via fluorescence imaging gives a remarkable concentration of 3.3 × 10(3) oligonucleotides/μm(2), almost totally active when used as probes in DNA-DNA hybridization assays. Indeed, fluorescence and atomic force microscopy show a 95% efficiency in target binding and uniform DNA hybridization over printed areas.

  13. Effects of rapid thermal annealing conditions on GaInNAs band gap blueshift and photoluminescence intensity

    SciTech Connect

    Liverini, V.; Rutz, A.; Keller, U.; Schoen, S.

    2006-06-01

    We have studied the effects of various conditions of rapid thermal annealing (RTA) on 10 nm GaInNAs/GaAs single quantum wells (SQWs) with fixed indium concentration and increasing nitrogen content to obtain photoluminescence (PL) in the telecom wavelength regime of 1.3 and 1.5 {mu}m. Specifically, we analyzed the results of annealing for a fixed short time but at different temperatures and for longer times at a fixed temperature. In all experiments, InGaAs SQWs with the same In concentration were used as references. For both RTA conditions, the well-known blueshift of the band gap energy and the PL intensity improvement show trends that reveal that these are unrelated effects. At high RTA temperatures the PL efficiency reaches a maximum and then drops independently of N content. On the contrary, the blueshift experiences a rapid increase up to 700 deg. C (strong blueshift regime) and it saturates above this temperature (weak blueshift regime). Both these blueshift regimes are related to the nitrogen content in the SQWs but in different ways. In the strong blueshift regime, we could obtain activation energy for the blueshift process in the range of 1.25 eV, which increases with N content. Analysis with high-resolution x-ray diffraction (HRXRD) shows that the blueshift experienced in this regime is not due to a stoichiometric change in the QW. In the weak blueshift regime, the blueshift, which is only partly due to In outdiffusion, saturates more slowly the higher the N content. Annealing at the same temperature (600 deg. C) for a longer time shows that the blueshift saturates earlier than the PL intensity and that samples with higher nitrogen experience a larger blueshift. Only a small In outdiffusion for annealing at high temperatures (>650 deg. C) and long duration was observed. However, this modest stoichiometric change does not explain the large blueshift experienced by the GaInNAs SQWs. We conclude that the mechanism responsible for the drastic blueshift after

  14. Origin of radiative recombination and manifestations of localization effects in GaAs/GaNAs core/shell nanowires

    SciTech Connect

    Chen, S. L.; Filippov, S.; Chen, W. M.; Buyanova, I. A.; Ishikawa, Fumitaro

    2014-12-22

    Radiative carrier recombination processes in GaAs/GaNAs core/shell nanowires grown by molecular beam epitaxy on a Si substrate are systematically investigated by employing micro-photoluminescence (μ-PL) and μ-PL excitation (μ-PLE) measurements complemented by time-resolved PL spectroscopy. At low temperatures, alloy disorder is found to cause localization of photo-excited carriers leading to predominance of optical transitions from localized excitons (LE). Some of the local fluctuations in N composition are suggested to lead to strongly localized three-dimensional confining potential equivalent to that for quantum dots, based on the observation of sharp and discrete PL lines within the LE contour. The localization effects are found to have minor influence on PL spectra at room temperature due to thermal activation of the localized excitons to extended states. Under these conditions, photo-excited carrier lifetime is found to be governed by non-radiative recombination via surface states which is somewhat suppressed upon N incorporation.

  15. The solution of linear systems of equations with a structural analysis code on the NAS CRAY-2

    NASA Technical Reports Server (NTRS)

    Poole, Eugene L.; Overman, Andrea L.

    1988-01-01

    Two methods for solving linear systems of equations on the NAS Cray-2 are described. One is a direct method; the other is an iterative method. Both methods exploit the architecture of the Cray-2, particularly the vectorization, and are aimed at structural analysis applications. To demonstrate and evaluate the methods, they were installed in a finite element structural analysis code denoted the Computational Structural Mechanics (CSM) Testbed. A description of the techniques used to integrate the two solvers into the Testbed is given. Storage schemes, memory requirements, operation counts, and reformatting procedures are discussed. Finally, results from the new methods are compared with results from the initial Testbed sparse Choleski equation solver for three structural analysis problems. The new direct solvers described achieve the highest computational rates of the methods compared. The new iterative methods are not able to achieve as high computation rates as the vectorized direct solvers but are best for well conditioned problems which require fewer iterations to converge to the solution.

  16. A room temperature Na/S battery using a β″ alumina solid electrolyte separator, tetraethylene glycol dimethyl ether electrolyte, and a S/C composite cathode

    NASA Astrophysics Data System (ADS)

    Kim, Icpyo; Park, Jin-Young; Kim, Chang Hyeon; Park, Jin-Woo; Ahn, Jae-Pyoung; Ahn, Jou-Hyeon; Kim, Ki-Won; Ahn, Hyo-Jun

    2016-01-01

    To realize a high-performance room temperature Na/S battery with an elemental sulfur cathode, it is important that sodium polysulfides stay within the cathode and that they have room enough to react freely. In this work, sodium polysulfides are confined to the cathode using a β″ alumina solid electrolyte separator and an optimal amount of tetraethylene glycol dimethyl ether (TEGDME) electrolyte. In addition, an activated carbon material, in the form of a sulfur/carbon (S/C) composite, with high surface area, porosity, and pore volume is employed in the cathode. The resulting Na/S battery shows a high first discharge capacity of 855 mAh g-1 and coulombic efficiency close to 100%, as well as stable cyclability, with a discharge capacity of 521 mAh g-1 at the 104th discharge.

  17. 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.

  18. MOVPE growth studies of Ga(NAsP)/(BGa)(AsP) multi quantum well heterostructures (MQWH) for the monolithic integration of laser structures on (001) Si-substrates

    NASA Astrophysics Data System (ADS)

    Ludewig, P.; Reinhard, S.; Jandieri, K.; Wegele, T.; Beyer, A.; Tapfer, L.; Volz, K.; Stolz, W.

    2016-03-01

    High-quality, pseudomorphically strained Ga(NAsP)/(BGa)(AsP)-multiple quantum well heterostructures (MQWH) have been deposited on exactly oriented (001) Si-substrate by metal organic vapour phase epitaxy (MOVPE) in a wide temperature range between 525 °C and 700 °C. The individual atomic incorporation efficiencies, growth rates as well as nanoscale material properties have been clarified by applying detailed high-resolution X-ray diffraction (HR-XRD), photoluminescence (PL) spectroscopy and high-angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) studies. An almost constant N-incorporation efficiency is obtained for a wide growth temperature range from 550 °C up to 650 °C. The P-incorporation is steadily increasing with increasing growth temperature reaching values at high temperatures in excess of the applied gas phase ratio. While the lower interface from the binary GaP- to the quaternary Ga(NAsP)-material system is very sharp, the upper interface is significantly rougher with a roughness scale of ±0.43 nm in quantum well thickness variation at a growth temperature of 525 °C. This roughness scale increases steadily with increasing growth temperature. No indication of any phase separation effects is detected in the Ga(NAsP)-material system even at the highest growth temperature of 700 °C. The obtained experimental results are briefly discussed with respect to the anticipated metastable character of the novel dilute-nitride Ga(NAsP)-material system grown lattice-matched to (001) Si-substrate.

  19. Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project, UAS Control and Non-Payload Communication System Phase-1 Flight Test Results

    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 status of the prototype radio development, and results from phase 1 flight tests conducted during 2013.

  20. Molecular beam epitaxy of GaNAs alloys with high As content for potential photoanode applications in hydrogen production

    SciTech Connect

    Novikov, S. V.; Staddon, C. R.; Foxon, C. T.; Yu, K. M.; Broesler, R.; Hawkridge, M.; Liliental-Weber, Z.; Walukiewicz, W.; Denlinger, J.; Demchenko, I.

    2009-10-06

    The authors have succeeded in growing GaN1?xAsx alloys over a large composition range (0 < x < 0.8) by plasma-assisted molecular beam epitaxy. The enhanced incorporation of As was achieved by growing the films with high As{sub 2} flux at low (as low as 100 C) growth temperatures, which is much below the normal GaN growth temperature range. Using x-ray and transmission electron microscopy, they found that the GaNAs alloys with high As content x > 0.17 are amorphous. Optical absorption measurements together with x-ray absorption and emission spectroscopy results reveal a continuous gradual decrease in band gap from -3.4 to < 1 eV with increasing As content. The energy gap reaches its minimum of -0.8 eV at x - 0.8. The composition dependence of the band gap of the crystalline GaN{sub 1?x}As{sub x} alloys follows the prediction of the band anticrossing model (BAC). However, our measured band gap of amorphous GaN{sub 1?x}As{sub x} with 0.3 < x < 0.8 are larger than that predicted by BAC. The results seem to indicate that for this composition range the amorphous GaN{sub 1?x}As{sub x} alloys have short-range ordering that resembles random crystalline GaN{sub 1?x}As{sub x} alloys. They have demonstrated the possibility of the growth of amorphous GaN{sub 1?x}As{sub x} layers with variable As content on glass substrates

  1. The NAS parallel benchmarks

    NASA Technical Reports Server (NTRS)

    Bailey, David (Editor); Barton, John (Editor); Lasinski, Thomas (Editor); Simon, Horst (Editor)

    1993-01-01

    A new set of benchmarks was developed for the performance evaluation of highly parallel supercomputers. These benchmarks consist of a set of kernels, the 'Parallel Kernels,' and a simulated application benchmark. Together they mimic the computation and data movement characteristics of large scale computational fluid dynamics (CFD) 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.

  2. Designing of 1 eV GaNAs/GaInAs superlattice subcell in current-matched four-junction solar cell

    NASA Astrophysics Data System (ADS)

    Haixiao, Wang; Xinhe, Zheng; Xingyuan, Gan; Naiming, Wang; Hui, Yang

    2016-01-01

    A reasonably-thick GaNAs/GaInAs superlattice could be an option as a roughly 1 eV subcell to achieve high-efficiency multi-junction solar cells on a lattice-matched Ge substrate. A detailed consideration of a high-efficiency design for a GaInP/GaAs/1 eV/Ge device is presented. Calculations have been done for this structure to obtain the confined energies of the electrons and holes by utilizing the Kronig-Penney model, as well as the absorption coefficient and thereby the external quantum efficiency. The effect of well layers, GaNAs or GaInAs, on the absorption and photocurrent density under the AM 1.5 condition is discussed in order to realize a requirement of current matching in the four-junction solar cells. The management of these considerations implies the feasibility of the GaNAs/GaInAs superlattice subcell design to improve the overall conversion efficiency of lattice matched GaInP/GaAs/1 eV/Ge cells. Project supported by the National Natural Science Foundation of China (No. 61274134) and the International Cooperation Program of Suzhou, China (No. SH201215).

  3. Development and manufacturing of panoramic Stokes polarimeter using the polarization films in the Main Astronomical Observatory of NAS of Ukraine

    NASA Astrophysics Data System (ADS)

    Vidmachenko, A. P.; Ivanov, Yu. S.; Syniavskyi, I. I.; Sergeev, A. V.

    2015-08-01

    In the Main Astronomical Observatory of NAS of Ukraine is proposed and implemented the concept of the imaging Stokes polarimeter [1-5]. This device allows carrying out measurements of the four Stokes vector components at the same time, in a wide field, and without any restrictions on the relative aperture of the optical system. Its scheme is developed so that only by turning wheel with replaceable elements, photopolarimeter could be transformed into a low resolution spectropolarimeter. The device has four film's polarizers with positional angles 0°, 45°, 90°, 135°. The device uses a system of special deflecting prisms in each channel. These prisms were achromatizing in the spectral range of 420-850 nm [2], the distortion of the polarimeter optical system is less than 0.65%. In manufacturing version of spectropolarimeter provided for the possibility of using working on passing the diffraction grating with a frequency up to 100 lines/mm. Has begun the laboratory testing of instrument. References. 1. Sinyavskii I.I., Ivanov Yu. S., Vidmachenko Anatoliy P., Karpov N.V. Panoramic Stokes-polarimeter // Ecological bulettin of research centers of the Black Sea Economic Cooperation. - 2013. - V. 3, No 4. - P. 123-127. 2. Sinyavskii I. I., Ivanov Yu. S., Vil'machenko A. P. Concept of the construction, of the optical setup of a panoramic Stokes polarimeter for small telescopes // Journal of Optical Technology. - 2013. - V. 80, Issue 9. - P. 545-548. 3. Vidmachenko A. P., Ivanov Yu. S., Morozhenko A. V., Nevodovsky E. P., Syniavskyi I. I., Sosonkin M. G. Spectropolarimeter of ground-based accompanying for the space experiment "Planetary Monitoring" // Kosmichna Nauka i Tekhnologiya. - 2007. - V. 13, No. 1, p. 63 - 70. 4. Yatskiv Ya. S., Vidmachenko A. P., Morozhenko A. V., Sosonkin M. G., Ivanov Yu. S., Syniavskyi I. I. Spectropolarimetric device for overatmospheric investigations of Solar System bodies // Kosmichna Nauka i Tekhnologiya. - 2008. - V. 14, No. 2. - P. 56

  4. On Ensino de Astronomia nas Cidades de Ribeirão Pires e Rio Grande da Serra

    NASA Astrophysics Data System (ADS)

    Faria, R. Z.; Voelzke, M. R.

    2007-08-01

    Apesar da astronomia ser um dos temas indicados pelos Parâmetros Curriculares Nacionais, observa-se que poucas mudanças ocorreram desde a implementação do mesmo em sala de aula. A presente pesquisa diz respeito sobre como os tópicos de astronomia estão sendo abordados pelos professores no ensino médio. Optou-se por aplicar um questionário com os professores que ministram a disciplina de física. Os mesmos trabalham em escolas estaduais situadas nas cidades de Ribeirão Pires e Rio Grande da Serra, ambas subordinadas a Diretoria de Ensino de Mauá, no Estado de São Paulo. O questionário foi aplicado durante o 2° semestre de 2006. Até o momento os resultados são preliminares. Dos 82,0% dos professores que responderam ao questionário no município de Rio Grande da Serra, 66,7% não aplicaram nenhum tópico de astronomia, 77,8% não utilizaram qualquer tipo de programa computacional, 66,7% não utilizaram laboratório, que 77,8% nunca levaram os alunos a museus e ou planetários e que 66,7% não indicaram qualquer tipo de revista ou livro sobre astronomia aos seus alunos. No município de Ribeirão Pires, 53,3% dos professores responderam ao questionário, destes 75,0% não aplicaram nenhum tópico de astronomia, 93,8% não utilizaram qualquer tipo de programa computacional, 75,0% não utilizaram laboratório, 81,3% nunca levaram os alunos a museus e ou planetário e 56,3% não indicaram qualquer tipo de revista ou livro sobre astronomia ao seus alunos. Apesar da maioria dos professores reconhecerem que o conteúdo de astronomia influi na formação do jovem, os mesmos não incluem o tema em seus planejamentos escolares.

  5. NOD promoter-controlled AtIRT1 expression functions synergistically with NAS and FERRITIN genes to increase iron in rice grains.

    PubMed

    Boonyaves, Kulaporn; Gruissem, Wilhelm; Bhullar, Navreet K

    2016-02-01

    Rice is a staple food for over half of the world's population, but it contains only low amounts of bioavailable micronutrients for human nutrition. Consequently, micronutrient deficiency is a widespread health problem among people who depend primarily on rice as their staple food. Iron deficiency anemia is one of the most serious forms of malnutrition. Biofortification of rice grains for increased iron content is an effective strategy to reduce iron deficiency. Unlike other grass species, rice takes up iron as Fe(II) via the IRON REGULATED TRANSPORTER (IRT) in addition to Fe(III)-phytosiderophore chelates. We expressed Arabidopsis IRT1 (AtIRT1) under control of the Medicago sativa EARLY NODULIN 12B promoter in our previously developed high-iron NFP rice lines expressing NICOTIANAMINE SYNTHASE (AtNAS1) and FERRITIN. Transgenic rice lines expressing AtIRT1 alone had significant increases in iron and combined with NAS and FERRITIN increased iron to 9.6 µg/g DW in the polished grains that is 2.2-fold higher as compared to NFP lines. The grains of AtIRT1 lines also accumulated more copper and zinc but not manganese. Our results demonstrate that the concerted expression of AtIRT1, AtNAS1 and PvFERRITIN synergistically increases iron in both polished and unpolished rice grains. AtIRT1 is therefore a valuable transporter for iron biofortification programs when used in combination with other genes encoding iron transporters and/or storage proteins.

  6. Molecular beam epitaxy growth of 1.55 μm GaInNAs(Sb) double quantum wells with bright and narrow photoluminescence

    NASA Astrophysics Data System (ADS)

    Gupta, J. A.; Sproule, G. I.; Wu, X.; Wasilewski, Z. R.

    2006-05-01

    GaInNAs(Sb)/GaNAs double quantum well (DQW) structures were grown on GaAs substrates using solid-source molecular beam epitaxy with N 2/Ar gas mixtures in a radio frequency plasma cell. A novel method of in situ antimony mass spectrometry is introduced which permits flux monitoring in the presence of large arsenic background pressures. For a DQW sample grown without Sb, bright and narrow (38.1 meV) room temperature photoluminescence (PL) emission at 1509 nm was achieved after optimized rapid thermal annealing. In two samples grown with antimony fluxes of approximately 0.012 and 0.028 monolayers/s the PL intensity improved and very bright PL was observed at 1518 and 1551 nm with linewidths of 33.1 and 35.0 meV, respectively. The integrated PL intensities of each of these two samples was equivalent to the emission for a reference GaInNAs/GaAs DQW sample emitting closer to 1.3 μm. More strikingly, the intensity of the Sb-free 1509 nm sample was only lower by a factor of 2. This suggests that the N 2/Ar plasma approach has benefits for the material quality, as well as providing efficient flux control, yielding good material even without Sb. High-resolution X-ray diffraction and transmission electron microscopy measurements indicate excellent crystal quality for all samples. Secondary ion mass spectrometry reveals a dramatic tendency for Sb segregation during growth, resulting in very asymmetric incorporation with most of the Sb atoms located at the top interface.

  7. The optical gain and radiative current density of GaInNAs/GaAs/AlGaAs separate confinement heterostructure quantum well lasers

    NASA Astrophysics Data System (ADS)

    Wu, Shudong; Cao, Yongge; Tomić, Stanko; Ishikawa, Fumitaro

    2010-01-01

    The optical gain and radiative current density of GaInNAs/GaAs/AlGaAs separate confinement heterostructure quantum well (QW) lasers with an emission wavelength of 1.3 μm have been theoretically investigated. The effect of carrier leakage from the GaInNAs QW to the GaAs waveguide layer is studied, and its influence on the optical gain and radiative current density is identified. The hole filling caused by an injected carrier has a strong impact on the optical gain and radiative current density, while the effect of electron filling is negligible, reflecting the smaller band-gap discontinuity in the valence band than in the conduction band. Hole occupation in the waveguide layer decreases the optical gain, and increases the radiative and threshold current densities of the laser. Our calculated threshold current density (659.6 A/cm2) at T=300 K is in good agreement with the experimental value (650.9 A/cm2) reported in literature [R. Fehse et al., IEEE J. Sel. Top. Quantum Electron. 8, 801 (2002)].

  8. High gain 1.3-μm GaInNAs SOA with fast gain dynamics and enhanced temperature stability

    NASA Astrophysics Data System (ADS)

    Fitsios, D.; Giannoulis, G.; Iliadis, N.; Korpijärvi, V.-M.; Viheriälä, J.; Laakso, A.; Dris, S.; Spyropoulou, M.; Avramopoulos, H.; Kanellos, G. T.; Pleros, N.; Guina, M.

    2014-03-01

    Semiconductor optical amplifiers (SOAs) are a well-established solution of optical access networks. They could prove an enabling technology for DataCom by offering extended range of active optical functionalities. However, in such costand energy-critical applications, high-integration densities increase the operational temperatures and require powerhungry external cooling. Taking a step further towards improving the cost and energy effectiveness of active optical components, we report on the development of a GaInNAs/GaAs (dilute nitride) SOA operating at 1.3μm that exhibits a gain value of 28 dB and combined with excellent temperature stability owing to the large conduction band offset between GaInNAs quantum well and GaAs barrier. Moreover, the characterization results reveal almost no gain variation around the 1320 nm region for a temperature range from 20° to 50° C. The gain recovery time attained values as short as 100 ps, allowing implementation of various signal processing functionalities at 10 Gb/s. The combined parameters are very attractive for application in photonic integrated circuits requiring uncooled operation and thus minimizing power consumption. Moreover, as a result of the insensitivity to heating issues, a higher number of active elements can be integrated on chip-scale circuitry, allowing for higher integration densities and more complex optical on-chip functions. Such component could prove essential for next generation DataCom networks.

  9. p- to n-type conductivity transition in 1.0 eV GaInNAs solar cells controlled by the V/III ratio

    SciTech Connect

    Langer, Fabian Perl, Svenja; Kamp, Martin; Höfling, Sven

    2015-02-09

    In this work, we report a p- to n-type conductivity transition of GaInNAs (1.0 eV bandgap) layers in p-i-n dilute nitride solar cells continuously controlled by the V/III ratio during growth. Near the transition region, we were able to produce GaInNAs layers with very low effective electrically active doping concentrations resulting in wide depleted areas. We obtained internal quantum efficiencies (IQEs) up to 85% at 0.2 eV above the bandgap. However, the high IQE comes along with an increased dark current density resulting in a decreased open circuit voltage of about 0.2 V. This indicates the formation of non-radiant defect centers related to the p-type to n-type transition. Rapid-thermal annealing of the solar cells on the one hand helps to anneal some of these defects but on the other hand increases the effective doping concentrations.

  10. Fisica a escala de Planck usando o principio de incerteza generalizado: efeitos nas flutuações primordiais e buracos negros

    NASA Astrophysics Data System (ADS)

    Horvath, J. E.; Custódio, P. S.

    2003-08-01

    Em escalas proximas à escala de Planck todas as teorias perturbativas de cordas produzem essenciamente a mesma relação de conmutação entre as coordenadas e impulsos (a chamada "álgebra deformada"), permitindo assim estudar a física resultante independentemente dos detalhes da teoria de cordas que seja considerada correta. Este resultado completamente geral, que inclui as interações gravitacionais junto com o resto dos campos pode ser considerada uma versão generalizada (GUP) do Princípio de Incerteza de Heisenberg. Aplicamos neste trabalho essas relações de conmutação para dois sistemas físicos bem definidos: buracos negros de massas próximas à massa de Planck, e flutuações quânticas em pequenas escalas antes do universo sofrer inflação. Obtemos dois resultados concretos dos efeitos do GUP : o primeiro é que o GUP impede a evaporação completa de buracos negros microscópicos na extensão do formalismo semiclássico, deixando assim remanescentes de pequena massa que já foram postulados como candidatos a matéria escura. O segundo resultado é o 'smoothing' das flutuações primordiais em pequenas escalas que levariam à produção de buracos negros primordiais após a inflação, impedindo assim a produção abundante destes últimos e predizendo abundancias atuais bem menores do que os limites disponíveis. Concluimos que, analogamente a utilização do Princípio de Incerteza de Heisenberg para estudar e determinar propriedades fundamentais das interações sem gravitação, o GUP e uma ferramenta poderosa para estudar uma ampla variedade de sistemas trans-Planckianos e predizer seu comportamento dispensando cálculos mais detalhados proprios da teoria quântica da gravitação.

  11. GaAs/AlGaAs resonant tunneling diodes with a GaInNAs absorption layer for telecommunication light sensing

    NASA Astrophysics Data System (ADS)

    Hartmann, F.; Langer, F.; Bisping, D.; Musterer, A.; Höfling, S.; Kamp, M.; Forchel, A.; Worschech, L.

    2012-04-01

    Al0.6Ga0.4As/GaAs/Al0.6Ga0.4As double-barrier resonant-tunneling diodes (RTD) were grown by molecular beam epitaxy with a nearby, lattice-matched Ga0.89In0.11N0.04As0.96 absorption layer. RTD mesas with ring contacts and an aperture for optical excitation of charge carriers were fabricated on the epitaxial layers. Electrical and optical properties of the RTDs were investigated for different thicknesses of a thin GaAs spacer layer incorporated between the AlGaAs tunnel barrier adjacent to the GaInNAs absorption layer. Illumination of the RTDs with laser light of 1.3 μm wavelength leads to a pronounced photo-effect with a sensitivities of around 103 A/W.

  12. Uncooled 2.5 Gb/s operation of 1.3 μm GaInNAs DQW lasers over a wide temperature range

    NASA Astrophysics Data System (ADS)

    Wei, Yongqiang; Gustavsson, Johan S.; Sadeghi, Mahdad; Wang, Shumin; Larsson, Anders; Savolainen, Pekka; Melanen, Petri; Sipilä, Pekko

    2006-04-01

    Ridge waveguide 1.3 μm GaInNAs lasers were fabricated from high quality double quantum well material grown by molecular beam epitaxy. Short cavity (250 μm) lasers have low threshold currents and small temperature dependencies of threshold current and slope efficiency, with a characteristic temperature of the threshold current as high as 200 K. The temperature stability allows for uncooled 2.5 Gb/s operation up to temperatures as high as 110°C with a constant modulation voltage and only the bias current adjusted for constant average output power. Under these conditions, an extinction ratio larger than 6 dB and a spectral rms-width smaller than 2 nm are obtained.

  13. Uncooled 2.5 Gb/s operation of 1.3 mum GaInNAs DQW lasers over a wide temperature range.

    PubMed

    Wei, Yongqiang; Gustavsson, Johan S; Sadeghi, Mahdad; Wang, Shumin; Larsson, Anders; Savolainen, Pekka; Melanen, Petri; Sipilä, Pekko

    2006-04-01

    Ridge waveguide 1.3 mum GaInNAs lasers were fabricated from high quality double quantum well material grown by molecular beam epitaxy. Short cavity (250 mum) lasers have low threshold currents and small temperature dependencies of threshold current and slope efficiency, with a characteristic temperature of the threshold current as high as 200 K. The temperature stability allows for uncooled 2.5 Gb/s operation up to temperatures as high as 110 degrees C with a constant modulation voltage and only the bias current adjusted for constant average output power. Under these conditions, an extinction ratio larger than 6 dB and a spectral rms-width smaller than 2 nm are obtained. PMID:19516408

  14. Correlation of the nanostructure with optoelectronic properties during rapid thermal annealing of Ga(NAsP) quantum wells grown on Si(001) substrates

    NASA Astrophysics Data System (ADS)

    Wegele, Tatjana; Beyer, Andreas; Gies, Sebastian; Zimprich, Martin; Heimbrodt, Wolfram; Stolz, Wolfgang; Volz, Kerstin

    2016-01-01

    Ga(NAsP) quantum wells grown pseudomorphically on Si substrate are promising candidates for optically active light sources in future optoelectronically integrated circuits on Si substrates. As the material is typically grown at low temperatures, it has to be thermally annealed after growth to remove defects and optimize optoelectronic properties. Here we show by quantitative transmission electron microscopy that two different kinds of structural development are associated with the annealing. First of all, the quantum well homogeneity improves with increasing annealing temperature. For annealing temperatures above 925 °C the composition becomes less homogeneous again. Second, voids form in the quantum well for annealing temperatures above 850 °C. Their density and size increase continuously with increasing annealing temperature. These results are correlated to the optical properties of the samples, where we find from temperature-dependent photoluminescence measurements two scales of disorder, which show the same temperature dependence as the structural properties.

  15. Optimal Blast Condition for the Inner Surface of Mass Produced NAS Battery Cylindrical Aluminum Cell Containers as Pretreatment of Thermal Spraying

    NASA Astrophysics Data System (ADS)

    Ando, Takashi; Harada, Yoshio

    The relationship between roughness caused by blasting and adhesion of spray coatings on aluminum container substrates was studied through various experiments as part of measures for improving the adhesion of the 75mass%Cr-Fe alloy plasma spray coating for sulfi dation corrosion resistance, which is applied on the inner surface of cylindrical Al containers of high-temperature type NAS batteries. Surface roughness of μmRa2.8 - 7.3 was acquired by using Al2O3 particle size #100 (212 - 75μm) to #46 (600 - 250μm) grit. In order to achieve uniform roughness and a clean surface, a combination of blasting when the nozzle was being inserted from the top of the container, and air blowing when the nozzle was being removed was done. It was determined that when Al2O3 particles of size #100 grit was used, a good anchoring shape was formed throughout with a roughened surface of μmRa 2.8. When the internal surface of 3000 Al cylindrical containers were continually blasted using particle size #100 grit, the initial surface roughness of μmRa3.7 - 3.9 only deteriorated to about μmRa2.6. A 75mass%Cr-Fe alloy spray coating was applied to the Al cylindrical containers that were roughened using particle size #100 grit. This coating showed cracks by a bending test, but no peeling occurred. This coating was examined by a tensile strength test and showed good adhesion at 64 - 66 MPa. Through experiments, it was proven that spray coatings formed on the Al cylindrical containers after receiving optimal blasting with particle size #100 grit had good adhesion and corrosion resistance after being used for NAS batteries that stored electrical power for about nine years.

  16. Vertical Distribution of Bacterial Communities in the Indian Ocean as Revealed by Analyses of 16S rRNA and nasA Genes.

    PubMed

    Jiang, Xuexia; Jiao, Nianzhi

    2016-09-01

    Bacteria play an important role in the marine biogeochemical cycles. However, research on the bacterial community structure of the Indian Ocean is scarce, particularly within the vertical dimension. In this study, we investigated the bacterial diversity of the pelagic, mesopelagic and bathypelagic zones of the southwestern Indian Ocean (50.46°E, 37.71°S). The clone libraries constructed by 16S rRNA gene sequence revealed that most phylotypes retrieved from the Indian Ocean were highly divergent from those retrieved from other oceans. Vertical differences were observed based on the analysis of natural bacterial community populations derived from the 16S rRNA gene sequences. Based on the analysis of the nasA gene sequences from GenBank database, a pair of general primers was developed and used to amplify the bacterial nitrate-assimilating populations. Environmental factors play an important role in mediating the bacterial communities in the Indian Ocean revealed by canonical correlation analysis. PMID:27407295

  17. Enhancement in photoluminescence from 1 eV GaInNAs epilayers subject to 7 MeV electron irradiation

    NASA Astrophysics Data System (ADS)

    Pavelescu, E.-M.; Kudrawiec, R.; Bălţăţeanu, N.; Spânulescu, S.; Dumitrescu, M.; Guina, M.

    2013-02-01

    We have investigated the influence of 7 MeV electron irradiation (1014-1015 cm-2 range) and subsequent rapid thermal annealing (RTA) on luminescence efficiency of nearly lattice-matched 1 eV GaInNAs-on-GaAs epilayers, grown by molecular beam epitaxy. The study has been done by means of 9 K photoluminescence (PL) and 300 K photoreflectance (PR) spectroscopy. Electron irradiation was found to directly promote a notable increase in PL intensity. A further PL enhancement, remarkable at the higher annealing temperature, has been seen upon two RTA stages (at 800 and 900 °C) applied to irradiated samples as compared to a non-irradiated sample. This irradiation-promoted PL enhancement upon annealing occurred with a small additional blue-shift of PL for the lower temperature-annealed samples but no additional shift in PL was noted for the higher temperature-annealed sample. The additional annealing-induced PL blue-shift was mainly due to an irradiation-promoted enhancement in In-N bonds formation, whose magnitude does not appear to depend on dose within the studied range.

  18. Vertical Distribution of Bacterial Communities in the Indian Ocean as Revealed by Analyses of 16S rRNA and nasA Genes.

    PubMed

    Jiang, Xuexia; Jiao, Nianzhi

    2016-09-01

    Bacteria play an important role in the marine biogeochemical cycles. However, research on the bacterial community structure of the Indian Ocean is scarce, particularly within the vertical dimension. In this study, we investigated the bacterial diversity of the pelagic, mesopelagic and bathypelagic zones of the southwestern Indian Ocean (50.46°E, 37.71°S). The clone libraries constructed by 16S rRNA gene sequence revealed that most phylotypes retrieved from the Indian Ocean were highly divergent from those retrieved from other oceans. Vertical differences were observed based on the analysis of natural bacterial community populations derived from the 16S rRNA gene sequences. Based on the analysis of the nasA gene sequences from GenBank database, a pair of general primers was developed and used to amplify the bacterial nitrate-assimilating populations. Environmental factors play an important role in mediating the bacterial communities in the Indian Ocean revealed by canonical correlation analysis.

  19. 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.

  20. The role of Sb and N ions on the morphology and localization of (Ga,In) (N,As) quantum wells

    NASA Astrophysics Data System (ADS)

    Guzmán, A.; Luna, E.; Ishikawa, F.; Trampert, A.

    2009-03-01

    A comparative study of the influence of Sb and N ion concentration on the properties of GaInNAs (GINA) quantum wells (QWs) is presented. We find that for perfect two-dimensional (2D) QW there is no direct perceptible improvement in structural quality due to the introduction of Sb. Moreover, contrast variations in the QW suggest an inhomogeneous Sb incorporation. A different behaviour of the integrated photoluminescence (PL) intensity with temperature is observed when comparing the 2D samples grown with/without Sb. Regarding the GINA QWs exhibiting a three-dimensional (3D) morphology, we observe a significant improvement in structural quality for the samples grown with added Sb, as well as for those Sb-free samples but grown under a low N- ions density. Nevertheless, 2D and 3D samples show clear common properties: the GINA:Sb QWs exhibit an improved PL efficiency, but only at high temperatures. On the contrary, the Sb-free samples grown under a low N- ions concentration exhibit a brighter PL at all temperatures considered.

  1. DNA microarray-based solid-phase PCR on copoly (DMA-NAS-MAPS) silicon coated slides: An example of relevant clinical application.

    PubMed

    Damin, Francesco; Galbiati, Silvia; Ferrari, Maurizio; Chiari, Marcella

    2016-04-15

    In a previous study we developed a highly sensitive DNA microarray for the detection of common KRAS oncogenic mutations, which has been proven to be highly specific in assigning the correct genotype without any enrichment strategy even in the presence of minority mutated alleles. However, in this approach, the need of a spotter for the deposition of the purified PCR products on the substrates and the purification step of the conventional PCR are serious drawbacks. To overcome these limitations we have introduced the solid-phase polymerase chain reaction (SP-PCR) to form the array of PCR products starting from the oligonucleotide primers. This work was possible thanks to the great thermal stability of the copoly (DMA-NAS-MAPS) coating which withstands PCR thermal cycling temperatures. As an example of the application of this platform we performed the analysis of six common mutations in the codon 12 of KRAS gene (G12A, G12C, G12D, G12R, G12S, and G12V). In conclusion solid-phase PCR, combined with dual-color hybridization, allows mutation analysis in a shorter time span and is more suitable for automation.

  2. X-ray Diffraction Measurement of GaInNAs/GaAs Double Quantum Well Structures with Novel Analysis Method for Broadening Factors

    NASA Astrophysics Data System (ADS)

    Nakashima, Kiichi; Tateno, Kouta

    2006-09-01

    The structural deterioration of GaInNAs/GaAs double-quantum-well (DQW) samples was analyzed by X-ray diffraction measurement with a novel peak broadening method. We effectively analyzed broadening properties by taking the difference between 004 X-ray satellite profiles measured with two different types of scanning configuration: a conventional configuration without a receiving slit and that with an analyzer crystal placed in front of a receiving detector. We found that the broadening due to structural deterioration can be simply and clearly analyzed by focusing attention on the difference between two types of profile shape, particularly at the valley minimum parts of satellite patterns. It is demonstrated that the difference at the valley minimum parts clearly represents various aspects of the deterioration of DQW structures. Particularly, it is remarkable that not only the degree of deterioration of the DQW structures but also the change in broadening mechanism due to the proceeding deterioration can be effectively analyzed. We propose and formulate a new simple method for analyzing the difference in valley shape by introducing two characteristic indices representing the difference. It is experimentally demonstrated that the new method is effective in both sensitively detecting and characterizing the deterioration of DQW structures by identifying broadening due to tilt distribution or lateral size effects of mosaic structures. From these results, it is concluded that the analysis of the valley minimum parts of profiles is a simple and effective tool for X-ray diffraction measurement.

  3. Pratt and Whitney/Boeing Engine Validation of Noise Reduction Concepts: Final Report for NASA Contract NAS3-97144, Phase 1

    NASA Technical Reports Server (NTRS)

    Mathews, Douglas; Bock, Larry A.; Bielak, Gerald W.; Dougherty, R. P.; Premo, John W.; Scharpf, Dan F.; Yu, Jia

    2014-01-01

    Major airports in the world's air transportation systems face a serious problem in providing greater capacity to meet the ever increasing demands of air travel. This problem could be relieved if airports are allowed to increase their operating time, now restricted by curfews and by relaxing present limits on takeoffs and landings. The key operational issue in extending the present curfews is noise. In response to these increasing restrictive noise regulations, NASA has launched a program to validate through engine testing, noise reduction concepts and technologies that have evolved from the Advanced Subsonic Technologies (AST) Noise Reduction Program. The goal of this AST program was to develop and validate technology that reduces engine noise and improves nacelle suppression effectiveness relative to 1992 technology. Contract NAS3-97144 titled "Engine Validation of Noise Reduction Concepts" (EVNRC) was awarded to P&W on August 12, 1997 to conduct full scale noise reduction tests in two Phases on a PW4098 engine. The following Section 1.2 provides a brief description of the overall program. The remainder of this report provides a detailed documentation of Phase I of the program.

  4. Electric Machines with Non-Radially Mounted Rectangular Permanent Magnets / Elektriskās Mašīnas Ar Prizmatiskiem Neradiāli Novietotiem Pastāvīgajiem Magnētiem

    NASA Astrophysics Data System (ADS)

    Levin, N.; Pugachev, V.; Dirba, J.; Lavrinovicha, L.

    2013-04-01

    The authors analyze the advantages and disadvantages of brushless synchronous electric machines with radially and non-radially mounted rectangular permanent magnets. The results show that the proposed nonradial mounting of permanent magnets considered in the paper, in several cases (e.g. multi-pole brushless generators with tooth windings of the armature) allows achievement of the following advantages: better technology of manufacturing the electric machine owing to simple packing of the stator winding in the stator open slots, which also increases the copper slot fillfactor; reduction in the mass-and-size of permanent magnets at least twice; significantly lower cost of the electric machine; and, finally, its greater specific power. Darbā tiek analizētas priekšrocības un trūkumi sinhronām bezkontaktu mašīnām ar radiāli un neradiāli novietotiem prizmatiskiem pastāvīgajiem magnētiem. Parādīts, ka vairākos gadījumos, piemēram, daudzpolu bezkontaktu sinhronajos ģeneratoros ar zobu tinumiem, neradiāls pastāvīgo magnētu izvietojums nodrošina vairākas priekšrocības: uzlabojas mašīnas izgatavošanas tehnoloģija, jo statora atvērtajās rievās vieglāk novietot tinumus un iespējams sasniegt augstāku rievas aizpildījuma koeficientu; samazinās pastāvīgo magnētu masa un izmaksas; palielinās mašīnas īpatnēja jauda.

  5. High-gain 1.3  μm GaInNAs semiconductor optical amplifier with enhanced temperature stability for all-optical signal processing at 10  Gb/s.

    PubMed

    Fitsios, D; Giannoulis, G; Korpijärvi, V-M; Viheriälä, J; Laakso, A; Iliadis, N; Dris, S; Spyropoulou, M; Avramopoulos, H; Kanellos, G T; Pleros, N; Guina, M

    2015-01-01

    We report on the complete experimental evaluation of a GaInNAs/GaAs (dilute nitride) semiconductor optical amplifier that operates at 1.3 μm and exhibits 28 dB gain and a gain recovery time of 100 ps. Successful wavelength conversion operation is demonstrated using pseudorandom bit sequence 27-1 non-return-to-zero bit streams at 5 and 10  Gb/s, yielding error-free performance and showing feasibility for implementation in various signal processing functionalities. The operational credentials of the device are analyzed in various operational regimes, while its nonlinear performance is examined in terms of four-wave mixing. Moreover, characterization results reveal enhanced temperature stability with almost no gain variation around the 1320 nm region for a temperature range from 20°C to 50°C. The operational characteristics of the device, along with the cost and energy benefits of dilute nitride technology, make it very attractive for application in optical access networks and dense photonic integrated circuits. PMID:25967005

  6. High-gain 1.3  μm GaInNAs semiconductor optical amplifier with enhanced temperature stability for all-optical signal processing at 10  Gb/s.

    PubMed

    Fitsios, D; Giannoulis, G; Korpijärvi, V-M; Viheriälä, J; Laakso, A; Iliadis, N; Dris, S; Spyropoulou, M; Avramopoulos, H; Kanellos, G T; Pleros, N; Guina, M

    2015-01-01

    We report on the complete experimental evaluation of a GaInNAs/GaAs (dilute nitride) semiconductor optical amplifier that operates at 1.3 μm and exhibits 28 dB gain and a gain recovery time of 100 ps. Successful wavelength conversion operation is demonstrated using pseudorandom bit sequence 27-1 non-return-to-zero bit streams at 5 and 10  Gb/s, yielding error-free performance and showing feasibility for implementation in various signal processing functionalities. The operational credentials of the device are analyzed in various operational regimes, while its nonlinear performance is examined in terms of four-wave mixing. Moreover, characterization results reveal enhanced temperature stability with almost no gain variation around the 1320 nm region for a temperature range from 20°C to 50°C. The operational characteristics of the device, along with the cost and energy benefits of dilute nitride technology, make it very attractive for application in optical access networks and dense photonic integrated circuits.

  7. Response to Questions on Presentation to NAS

    SciTech Connect

    Meier, W R

    2011-03-17

    Response to questions on the presentation 'Overview to Chamber and Power Plant Designs for IFE' made at the 1/29-31 meeting of the National Academies Committee on the Prospects for Inertial Confinement Fusion Energy Systems.

  8. Input to NAS Plasma 2010 panel

    SciTech Connect

    Molvik, A W

    2006-01-30

    A number of areas of plasma physics have had outstanding success over the last decade. The author comments on progress in understanding and manipulating particle beams, a variety of non-neutral plasmas. Some of the key manipulations were made possible by immersing a particle beam in neutral plasma in order to greatly reduce space-charge forces on the beam.

  9. Ecological risk assessment framework -- the NAS perspective

    SciTech Connect

    Barnthouse, L.W.

    1993-06-01

    A Workshop on Ecological Risk Assessment was held on February 26--March 1, 1991, at Airlie House, Warrenton, Virginia. In addition to presentation and discussion of the case study papers, the workshop included breakout sessions to discuss conceptual and technical aspects of ecological risk assessment. A general consensus emerged that an ecological version of the 1983 framework is desirable and feasible. The committee concluded that the 1983 human health framework could be expanded to accomodate both human health and ecological risk assessment. For general applicability to ecological assessments, the 1983 scheme requires augmentation to address some of the interfaces between science and management, primarily because of the need to focus on appropriate questions relevant to applicable environmental law and policy under different circumstances. Specifically, the scheme needs modification to address (1) the influence of legal and regulatory considerations on the initial stages of ecological risk assessment and (2) the importance of characterizing ecological risks in terms that are intelligible to risk managers. The committee`s opinion is that these augmentations are as important for human health risk assessment as they are for ecological risk assessment. This paper briefly describes the framework recommended by the Committee and compares it to EPA`s recently-published Framework for Ecological Risk Assessment.

  10. F/NAS/ Pressure Temperature Retrieval Techniques

    NASA Technical Reports Server (NTRS)

    Poularikas, Alexander

    1995-01-01

    The purpose of this investigation is to study methods and ways for rapid inversion programs involving the correlated k-method, and to modify the existing programs so that the rapid analysis of data can be accomplished. This short paper presents the background regarding the research as well as accomplishments made during the contract period.

  11. NAS Report Reveals Dangers From SST

    ERIC Educational Resources Information Center

    Fowler, Jo Ann V.

    1973-01-01

    Reported are some harmful effects of supersonic travel on humans and other living organisms. Slight decreases in ozone concentration as a result of emissions from the SST aircrafts reduce absorption of ultraviolet radiation. Effects of this may include skin cancer, distort balance of activity in cells and have a deleterious effect on insects and…

  12. The NAS Perchlorate Review: Adverse Effects?

    SciTech Connect

    Johnston, Richard B.; Corley, Richard; Cowan, Linda; Utiger, Robert D.

    2005-11-01

    To the editor: Drs. Ginsberg and Rice argue that the reference dose for perchlorate of 0.0007 mg/kg per day recommended by the National Academies’ Committee to Assess the Health Implications of Perchlorate Ingestion is not adequately protective. As members of the committee, we disagree. Ginsberg and Rice base their conclusion on three points. The first involves the designation of the point of departure as a NOEL (no-observed-effect level) versus a LOAEL (lowest-observed-adverse- effect level). The committee chose as its point of departure a dose of perchlorate (0.007 mg/kg per day) that when given for 14 days to 7 normal subjects did not cause a significant decrease in the group mean thyroid iodide uptake (Greer et al. 2002). Accordingly, the committee considered it a NOEL. Ginsberg and Rice focus on the fact that only 7 subjects were given that dose, and they 1seem to say that attention should be paid only to the results in those subjects in whom there was a 1fall in thyroid iodide uptake, and that the results in those in whom there was no fall or an increase should be ignored. They consider the dose to be a LOAEL because of the fall in uptake in those few subjects. It is important to note that a statistically significant decrease of, for example, 5% or even 10%, would not be biologically important and, more important, would not be sustained. For example, in another study (Braverman et al. 2004), administration of 0.04 mg/kg per day to normal subjects for 6 months had no effect on thyroid iodide uptake when measured at 3 and 6 months, and no effect on serum thyroid hormone or thyrotropin concentrations measured monthly (inspection of Figure 5A in the paper by Greer et al. suggests that this dose would inhibit thyroid iodide uptake by about 25% if measured at 2 weeks). The second issue involves database uncertainty. In clinical studies, perchlorate has been administered prospectively to 68 normal subjects for 2 weeks to 6 months. In one study (Brabant et al. 1992), a dose of 9.2 mg/kg per day for 4 weeks had no effect on thyroid function. In occupational studies, doses as high as 0.5 mg/kg per day were not associated with adverse effects on thyroid function in workers. In epidemiologic studies, there were no abnormalities in growth or thyroid function in children exposed life-long to 100 to 120 mg of perchlorate per liter of drinking water, or in pregnant women and newborn infants similarly exposed. Given the choice of a non-adverse effect (inhibition of iodide uptake by the thyroid) as the point of departure and the multiple studies in which doses of perchlorate much larger than 0.007 mg/kg per day had no effect on any aspect of thyroid function, the committee did not apply a database uncertainty factor. Finally, Ginsberg and Rice argue that inhibition of thyroid iodide uptake is adverse. That conclusion assumes that any acute inhibition would be sustained, so that thyroid hormone production would fall. That is not the case. There is remarkable compensation for even substantial reductions in thyroid iodide uptake – and thyroid hormone production. As noted above, subjects given 0.04 mg/kg per day for 6 months and 9.2 mg/kg per day for 4 weeks-doses that certainly would inhibit thyroid iodide uptake for a few weeks-had no fall in serum thyroid hormone or rise in serum thyrotropin concentrations (the hallmark of even minor systemic thyroid deficiency). Short-term inhibition of thyroid iodide uptake is not an adverse effect; it has no adverse consequences, because there is rapid compensation mediated by several independent processes. One is upregulation of the thyroid sodium-iodide transport system, as a result of intrathyroidal iodide deficiency. The second, should there be even a very small fall in thyroid hormone production, is an increase in thyrotropin secretion, resulting in overall stimulation of the thyroid gland.

  13. F/NAS/ Pressure Temperature Retrieval Techniques

    NASA Technical Reports Server (NTRS)

    Poularikas, Alexander

    1998-01-01

    The purpose of this investigation is to study methods and ways for rapid inversion programs involving the correlated k-method, and to modify the existing programs so that the rapid analysis of data can be accomplished. The earth's atmosphere as well as those around the planets consist of gases which emit radiation in the infrared spectral region, providing wealth of information about chemical and physical processes in the atmosphere. The atmospheric molecular constituents absorb and radiate by vibrational and rotational transitions, and the observed spectra exhibit characteristic spectral features in the region of the electromagnetic spectrum. The observed absorption or thermal emission spectra may be obtained with space-borne high resolution infrared spectrometers the 50-1000 micrometers spectral region. A detailed analysis of the observed spectra leads to information about the atmospheric thermal structure, composition, and the physical and chemical processes. The analytic techniques involve the development of radiative transfer models for the calculation of the observed radiance and transmittances for realistic atmospheric conditions and observational geometries, and the development of inversion methods for retrieval of atmospheric parameters from the observations.

  14. F/NAS/Pressure Temperature Retrieval Techniques

    NASA Technical Reports Server (NTRS)

    Poularikas. Alexander

    1998-01-01

    The purpose of this investigation is to study methods and ways for rapid inversion programs involving the correlated k-method, and to modify the existing programs so that the rapid analysis of data can be accomplished. Extensive modifications of the software programs were introduced. These modifications were imposed on the radiative transfer models and inversion methods and resulted in incorporating some important atmospheric processes not previously considered. The software also was improved to handle several toxic gases, gases that were observed in Saturn's atmosphere, and to retrieve pressure-temperature profiles from infrared solar absorption spectra.

  15. Strategic Plans for the Future of Solar Physics: a community discussion of the NASA Sun-Earth Connection Program Roadmap and the NAS Decadal Survey of Astronomy and Astrophysics (Solar Astronomy section)

    NASA Astrophysics Data System (ADS)

    Schrijver, K.; Knoelker, M.

    1999-05-01

    optimal representation for solar physics in the Decadal Survey. The Roadmap Committee and the Decadal Survey's solar panel encourage the whole solar physics community to contact them prior to the meeting. The list of the committee/panel members and their e-mail addresses, as well as related information, can be accessed via their websites at http://www.lmsal.com/sec/ and http://www.nas.edu/bpa/projects/astrosurvey/solar/ , respectively.

  16. Transforming the NAS: The Next Generation Air Traffic Control System

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz

    2004-01-01

    The next-generation air traffic control system must be designed to safely and efficiently accommodate the large growth of traffic expected in the near future. It should be sufficiently scalable to contend with the factor of 2 or more increase in demand expected by the year 2020. Analysis has shown that the current method of controlling air traffic cannot be scaled up to provide such levels of capacity. Therefore, to achieve a large increase in capacity while also giving pilots increased freedom to optimize their flight trajectories requires a fundamental change in the way air traffic is controlled. The key to achieving a factor of 2 or more increase in airspace capacity is to automate separation monitoring and control and to use an air-ground data link to send trajectories and clearances directly between ground-based and airborne systems. In addition to increasing capacity and offering greater flexibility in the selection of trajectories, this approach also has the potential to increase safety by reducing controller and pilot errors that occur in routine monitoring and voice communication tasks.

  17. Job Management Requirements for NAS Parallel Systems and Clusters

    NASA Technical Reports Server (NTRS)

    Saphir, William; Tanner, Leigh Ann; Traversat, Bernard

    1995-01-01

    A job management system is a critical component of a production supercomputing environment, permitting oversubscribed resources to be shared fairly and efficiently. Job management systems that were originally designed for traditional vector supercomputers are not appropriate for the distributed-memory parallel supercomputers that are becoming increasingly important in the high performance computing industry. Newer job management systems offer new functionality but do not solve fundamental problems. We address some of the main issues in resource allocation and job scheduling we have encountered on two parallel computers - a 160-node IBM SP2 and a cluster of 20 high performance workstations located at the Numerical Aerodynamic Simulation facility. We describe the requirements for resource allocation and job management that are necessary to provide a production supercomputing environment on these machines, prioritizing according to difficulty and importance, and advocating a return to fundamental issues.

  18. SITE TECHNOLOGY CAPSULE: NOVOCS EVALUATION AT NAS NORTH ISLAND

    EPA Science Inventory

    This is a SITE Technology Capsule. The MACTEC, Inc. (MACTEC), NoVOCs(TM) in-well volatile organic compounds (VOC) stripping technology is an in-situ groundwater remediation technology designed for the cleanup of groundwater contaminated with VOCs. The NoVOCs(TM) technology was ev...

  19. Flight Test Overview for UAS Integration in the NAS Project

    NASA Technical Reports Server (NTRS)

    Murphy, James R.; Hayes, Peggy S.; Kim, Sam K.; Bridges, Wayne; Marston, Michael

    2016-01-01

    The National Aeronautics and Space Administration is conducting a series of flight tests intended to support the reduction of barriers that prevent unmanned aircraft from flying without the required waivers from the Federal Aviation Administration. The most recent testing supported two separate test configurations. The first investigated the timing of Detect and Avoid (DAA) alerting thresholds using a radar-equipped unmanned vehicle and multiple live intruders flown at varying encounter geometries. The second configuration included a surrogate unmanned vehicle (flown from a ground control station, with a safety pilot on board) flying a mission in a virtual air traffic control airspace sector using research pilot displays and DAA advisories to maintain separation from live and virtual aircraft. The test was conducted over a seven-week span in the summer of 2015. The data from over 100 encounter sorties will be used to inform the RTCA Phase 1 Detect and Avoid and Command and Control Minimum Operating Performance Standards (MOPS) intended to be completed by the summer of 2016. Follow-on flight-testing is planned for the spring of 2016 to capture remaining encounters and support validation of the MOPS.

  20. NAS report gives advice on federal science policy

    NASA Astrophysics Data System (ADS)

    For 50 years, the United States poured money into basic research and subsequently reaped the rewards of that science. But in a major new report, the leaders of the government's science operation are calling for an overhaul of that system.The report “may be one of the most important things we've ever done,” outgoing National Academy of Sciences President Frank Press said during a recent congressional hearing. Produced by a joint committee of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine, it is entitled “Science, Technology and the Federal Government: National Goals for a New Era.”

  1. Feasibility study for a secondary Na/S battery

    NASA Technical Reports Server (NTRS)

    Abraham, K. M.; Schiff, R.; Brummer, S. B.

    1979-01-01

    The feasibility of a moderate temperature Na battery was studied. This battery is to operate at a temperature in the range of 100-150 C. Two kinds of cathode were investigated: (1) a soluble S cathode consisting of a solution of Na2Sn in an organic solvent and (2) an insoluble S cathode consisting of a transition metal dichalcogenide in contact with a Na(+)ion conducting electrolyte. Four amide solvents, dimethyl acetamide, diethyl acetamide, N-methyl acetamide and acetamide, were investigated as possible solvents for the soluble S cathode. Results of stability and electrochemical studies using these solvents are presented. The dialkyl substituted amides were found to be superior. Although the alcohol 1,3-cyclohexanediol was found to be stable in the presence of Na2Sn at 130 C, its Na2Sn solutions did not appear to have suitable electrochemical properties.

  2. UAS Integration in the NAS Project and Future Autonomy Research

    NASA Technical Reports Server (NTRS)

    Johnson, Charles W.

    2014-01-01

    This presentation highlights NASA use of unmanned aircraft systems (UAS) and related technologies for civil purposes. This briefing will give more insight into the UAS projects progress and future goals.

  3. Bush climate research plans draw mixed reaction From NAS panel

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    The Bush administration provided a guarded progress report on the development of its new climate change research initiatives during a November 19 meeting of the National Academy of Sciences' Committee on Global Change Research. Some committee members, however, criticized the plans as short on specifics and substance.Administration officials told the committee that two initiatives announced by President George W. Bush in June—the Climate Change Research Initiative (CCRI) and the Climate Change Technology Initiative (CCTI)—are nearing final stages of development as part of the fiscal year 2003 budget, and that efforts are being made to closely coordinate these projects with the ongoing U.S. Global Change Research Program (GCRP).

  4. NAS Associate Works on Environmental Implications of Nanoparticles

    EPA Science Inventory

    Dr. Manomita Patra joined the EPA's, Human Exposure and Atmospheric Sciences Division at the Las Vegas, NV location in June 2007. Her research project parallels her previous interests in the genotoxicity of mercury in plants. She is working with Dr. Kim Rogers and Tammy Jones-Lep...

  5. Comparison of leading parallel NAS file systems on commodity hardware

    SciTech Connect

    Hedges, R; Fitzgerald, K; Gary, M; Stearman, D M

    2010-11-08

    High performance computing has experienced tremendous gains in system performance over the past 20 years. Unfortunately other system capabilities, such as file I/O, have not grown commensurately. In this activity, we present the results of our tests of two leading file systems (GPFS and Lustre) on the same physical hardware. This hardware is the standard commodity storage solution in use at LLNL and, while much smaller in size, is intended to enable us to learn about differences between the two systems in terms of performance, ease of use and resilience. This work represents the first hardware consistent study of the two leading file systems that the authors are aware of.

  6. Science Policy: Former NAS Official Reviews World Science.

    ERIC Educational Resources Information Center

    Malone, Thomas F.

    1982-01-01

    Issues discussed with Thomas F. Malone (former Foreign Secretary-National Academy of Sciences) include: scientists role in dealing with such global problems as nuclear war and needs in developing countries; scientific relations with China/Soviet Union; scientific enterprise/human rights; science/technology role in foreign policy; and political…

  7. Development of Educational Resources to Include the Teaching of Astronomy in the First Years of the Basic Education. (Spanish Title: Desarrollo de Recursos Pedagógicos Para Incluir la Enseñanza de la Astronomía en los Primeros Años de la Educación Básica.) Desenvolvimento de Recursos Pedagógicos Para Inserir o Ensino de Astronomia nas Séries Iniciais do Ensino Fundamental

    NASA Astrophysics Data System (ADS)

    da Silva Morett, Samara; de Oliveira Souza, Marcelo

    2010-07-01

    ía y la vida cotidiana de los estudiantes. La inclusión de la astronomía en la escuela primaria es una manera de demostrar a los estudiantes cómo este campo está presente de forma activa en su vida cotidiana. Las clases que participan en el proyecto participaron en un estudio con el objetivo de proporcionar información a los conocimientos previos que tenían sobre los temas de la astronomía que se examinaron durante el proyecto. Con los experimentos realizados, y la ayuda de las nuevas tecnologías, conceptos astronómicos fueron presentados a los estudiantes de 4to y 5to año de la educación básica de una escuela municipal de Campos dos Goytacazes (RJ). Después de las presentaciones nuevos datos fueran colectados y se han llevado a cabo con el fin de verificar el nivel de aprendizaje alcanzado y se observó que el método utilizado fue una herramienta importante para ayudar al proceso de enseñanza y aprendizaje. El proyecto logró resultados satisfactorios. Neste trabalho será apresentado o desenvolvimento de recursos pedagógicos para a apresentação de conceitos de astronomia nas séries iniciais do ensino fundamental. Este material é composto por apresentações realizadas com o uso de novos recursos tecnológicos, pela fabricação de experimentos e a discussão de curiosidades relativas a esta área de conhecimento. Os experimentos foram construídos com material de baixo custo com o objetivo de permitir que os alunos envolvidos pudessem refazê-los em outras ocasiões. O material apresentado busca enfatizar a relação entre a astronomia e o cotidiano dos alunos. A inclusão da astronomia no ensino fundamental e uma forma de demonstrar aoestudante como esta área está presente de forma ativa em seu cotidiano. As turmas envolvidas no projeto participaram de uma pesquisa com o objetivo de obter dados relativos ao conhecimento prévio que possuíam sobre os tópicos de astronomia que foram considerados no decorrer do projeto. Com os experimentos

  8. Development of Educational Resources to Include the Teaching of Astronomy in the First Years of the Basic Education. (Spanish Title: Desarrollo de Recursos Pedagógicos Para Incluir la Enseñanza de la Astronomía en los Primeros Años de la Educación Básica.) Desenvolvimento de Recursos Pedagógicos Para Inserir o Ensino de Astronomia nas Séries Iniciais do Ensino Fundamental

    NASA Astrophysics Data System (ADS)

    da Silva Morett, Samara; de Oliveira Souza, Marcelo

    2010-07-01

    ía y la vida cotidiana de los estudiantes. La inclusión de la astronomía en la escuela primaria es una manera de demostrar a los estudiantes cómo este campo está presente de forma activa en su vida cotidiana. Las clases que participan en el proyecto participaron en un estudio con el objetivo de proporcionar información a los conocimientos previos que tenían sobre los temas de la astronomía que se examinaron durante el proyecto. Con los experimentos realizados, y la ayuda de las nuevas tecnologías, conceptos astronómicos fueron presentados a los estudiantes de 4to y 5to año de la educación básica de una escuela municipal de Campos dos Goytacazes (RJ). Después de las presentaciones nuevos datos fueran colectados y se han llevado a cabo con el fin de verificar el nivel de aprendizaje alcanzado y se observó que el método utilizado fue una herramienta importante para ayudar al proceso de enseñanza y aprendizaje. El proyecto logró resultados satisfactorios. Neste trabalho será apresentado o desenvolvimento de recursos pedagógicos para a apresentação de conceitos de astronomia nas séries iniciais do ensino fundamental. Este material é composto por apresentações realizadas com o uso de novos recursos tecnológicos, pela fabricação de experimentos e a discussão de curiosidades relativas a esta área de conhecimento. Os experimentos foram construídos com material de baixo custo com o objetivo de permitir que os alunos envolvidos pudessem refazê-los em outras ocasiões. O material apresentado busca enfatizar a relação entre a astronomia e o cotidiano dos alunos. A inclusão da astronomia no ensino fundamental e uma forma de demonstrar aoestudante como esta área está presente de forma ativa em seu cotidiano. As turmas envolvidas no projeto participaram de uma pesquisa com o objetivo de obter dados relativos ao conhecimento prévio que possuíam sobre os tópicos de astronomia que foram considerados no decorrer do projeto. Com os experimentos

  9. Large UAS Operations in the NAS - The NASA 2007 Western States Fire Missions (WSFM)

    NASA Technical Reports Server (NTRS)

    Buoni, Gregory P.; Howell, Kathleen M.

    2008-01-01

    Objectives: Demonstrate capabilities of UAS to overfly and collect sensor data on wildfires throughout Western US. Demonstrate long-endurance mission capabilities (20+ hours). Image multiple fires (greater than 4 fires per mission), to showcase extendable mission configuration and ability to either linger over key fires or station over disparate regional fires. Deliver real-time imagery to (within 10-minutes of acquisition).

  10. A Validation Study of Merging and Spacing Techniques in a NAS-Wide Simulation

    NASA Technical Reports Server (NTRS)

    Glaab, Patricia C.

    2011-01-01

    In November 2010, Intelligent Automation, Inc. (IAI) delivered an M&S software tool to that allows system level studies of the complex terminal airspace with the ACES simulation. The software was evaluated against current day arrivals in the Atlanta TRACON using Atlanta's Hartsfield-Jackson International Airport (KATL) arrival schedules. Results of this validation effort are presented describing data sets, traffic flow assumptions and techniques, and arrival rate comparisons between reported landings at Atlanta versus simulated arrivals using the same traffic sets in ACES equipped with M&S. Initial results showed the simulated system capacity to be significantly below arrival capacity seen at KATL. Data was gathered for Atlanta using commercial airport and flight tracking websites (like FlightAware.com), and analyzed to insure compatible techniques were used for result reporting and comparison. TFM operators for Atlanta were consulted for tuning final simulation parameters and for guidance in flow management techniques during high volume operations. Using these modified parameters and incorporating TFM guidance for efficiencies in flowing aircraft, arrival capacity for KATL was matched for the simulation. Following this validation effort, a sensitivity study was conducted to measure the impact of variations in system parameters on the Atlanta airport arrival capacity.

  11. 48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... waste and trash) 5 Sewage treatment plant equipment 5 Water treatment plant equipment 5 Washers (dish, cage, glass, etc.) 5 Sterilizing equipment 5 Water distilling equipment 5 Prefab temperature rooms... boiler plant system (Specified under 700 Sections) 5 General supply conveyors 10 Food service...

  12. 48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... waste and trash) 5 Sewage treatment plant equipment 5 Water treatment plant equipment 5 Washers (dish, cage, glass, etc.) 5 Sterilizing equipment 5 Water distilling equipment 5 Prefab temperature rooms... boiler plant system (Specified under 700 Sections) 5 General supply conveyors 10 Food service...

  13. 48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Percent Pneumatic Tube System 10 Incinerators (medical waste and trash) 5 Sewage treatment plant equipment 5 Water treatment plant equipment 5 Washers (dish, cage, glass, etc.) 5 Sterilizing equipment 5 Water distilling equipment 5 Prefab temperature rooms (cold, constant temperature) 5 Entire...

  14. 48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Percent Pneumatic Tube System 10 Incinerators (medical waste and trash) 5 Sewage treatment plant equipment 5 Water treatment plant equipment 5 Washers (dish, cage, glass, etc.) 5 Sterilizing equipment 5 Water distilling equipment 5 Prefab temperature rooms (cold, constant temperature) 5 Entire...

  15. 48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Percent Pneumatic Tube System 10 Incinerators (medical waste and trash) 5 Sewage treatment plant equipment 5 Water treatment plant equipment 5 Washers (dish, cage, glass, etc.) 5 Sterilizing equipment 5 Water distilling equipment 5 Prefab temperature rooms (cold, constant temperature) 5 Entire...

  16. 48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... waste and trash) 5 Sewage treatment plant equipment 5 Water treatment plant equipment 5 Washers (dish, cage, glass, etc.) 5 Sterilizing equipment 5 Water distilling equipment 5 Prefab temperature rooms... boiler plant system (Specified under 700 Sections) 5 General supply conveyors 10 Food service...

  17. 48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Percent Pneumatic Tube System 10 Incinerators (medical waste and trash) 5 Sewage treatment plant equipment 5 Water treatment plant equipment 5 Washers (dish, cage, glass, etc.) 5 Sterilizing equipment 5 Water distilling equipment 5 Prefab temperature rooms (cold, constant temperature) 5 Entire...

  18. 48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... waste and trash) 5 Sewage treatment plant equipment 5 Water treatment plant equipment 5 Washers (dish, cage, glass, etc.) 5 Sterilizing equipment 5 Water distilling equipment 5 Prefab temperature rooms... boiler plant system (Specified under 700 Sections) 5 General supply conveyors 10 Food service...

  19. Polymers: Technical activities, 1991. NAS-NRC Assessment Panel, February 13-14, 1992

    SciTech Connect

    Smith, L.E.; Fanconi, B.M.

    1991-10-01

    All of the Division's programs are described in the report, organized according to these six Groups. These Groups have made a number of significant accomplishments during the last year. Some of these are summarized below: A computer simulation was performed to model resin flow in liquid molding of the front end structure of a Ford Escort; A NIST/industry consortium has evolved for the purpose of developing in-line measurement technology based on optical and fluorescence methods; A combined light scattering photometer/rheometer has been constructed to examine phase separation behavior of polymer blends and solutions under the influence of a simple shear field; A unique new tool has been developed to study the physics involved in the adhesion between a polymer and a solid surface like glass; The distribution of polarization in poly(vinylidene fluoride) poled by corona discharge rather than by contacting electrodes indicated positive charge injection near the surface; Proton spin diffusion results indicated domain sizes in poly(butylmethacrylate)/hydroxy modified polystyrene blends with minimum dimensions in the 6-10 nm range and stoichiometries of the order of 75/25; Novel, siloxane-containing difunctional and multifunctional vinyl monomers were prepared; The apparent 'shift' in polymer blend phase separation temperature, Tc, under shear flow has been interpreted with the mode-coupling theory for mean-field polymer blend systems; The radial flow behavior was successfully predicted from measurements in unidirectional flow; An exposure technique that rapidly determines whether or not a polymer is biodegradable has been developed; Instrumentation has been set up and calibrated to measure the dielectric constant of thin polymer films at high electric fields; A viscoelastic model of stresses in porcelain-metal strips has been developed.

  20. Materials Data on NaS (SG:194) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  1. Posttest analysis of beta (Na/S) cells from chloride silent power, limited. Final report

    SciTech Connect

    Battles, J.E.; Mrazek, F.C.

    1985-12-01

    Researchers have developed a unique methodology for examining sodium/sulfur cells after testing to learn more about their behavior. The new techniques described in this report allow scientists to discern the physical and chemical states of these high-energy cells and to develop hypotheses about degradation mechanisms. This information may provide a basis for building cells with longer lives.

  2. Evaluation of the Terminal Precision Scheduling and Spacing System for Near-Term NAS Application

    NASA Technical Reports Server (NTRS)

    Thipphavong, Jane; Martin, Lynne Hazel; Swenson, Harry N.; Lin, Paul; Nguyen, Jimmy

    2012-01-01

    NASA has developed a capability for terminal area precision scheduling and spacing (TAPSS) to provide higher capacity and more efficiently manage arrivals during peak demand periods. This advanced technology is NASA's vision for the NextGen terminal metering capability. A set of human-in-the-loop experiments was conducted to evaluate the performance of the TAPSS system for near-term implementation. The experiments evaluated the TAPSS system under the current terminal routing infrastructure to validate operational feasibility. A second goal of the study was to measure the benefit of the Center and TRACON advisory tools to help prioritize the requirements for controller radar display enhancements. Simulation results indicate that using the TAPSS system provides benefits under current operations, supporting a 10% increase in airport throughput. Enhancements to Center decision support tools had limited impact on improving the efficiency of terminal operations, but did provide more fuel-efficient advisories to achieve scheduling conformance within 20 seconds. The TRACON controller decision support tools were found to provide the most benefit, by improving the precision in schedule conformance to within 20 seconds, reducing the number of arrivals having lateral path deviations by 50% and lowering subjective controller workload. Overall, the TAPSS system was found to successfully develop an achievable terminal arrival metering plan that was sustainable under heavy traffic demand levels and reduce the complexity of terminal operations when coupled with the use of the terminal controller advisory tools.

  3. A full CI treatment of Ne atom - A benchmark calculation performed on the NAS CRAY 2

    NASA Technical Reports Server (NTRS)

    Bauschlicher, C. W., Jr.; Langhoff, S. R.; Partridge, H.; Taylor, P. R.

    1986-01-01

    Full CI calculations are performed for Ne atom using Gaussian basis sets of up to triple-zeta plus double polarization quality. The total valence correlation energy through double, triple, quadruple and octuple excitations is compared for eight different basis sets. These results are expected to be an important benchmark for calibrating methods for estimating the importance of higher excitations.

  4. UAS Integration into the NAS: HSI Full Mission Simulation Preliminary Results

    NASA Technical Reports Server (NTRS)

    Shively, Jay; Fern, Lisa; Rorie, Conrad

    2014-01-01

    The goal of the Full Mission Sim was to examine the effects of different command and control interfaces on UAS pilots' ability to respond to ATC commands and traffic advisories. Results suggest that higher levels of automation (i.e., waypoint-to-waypoint control interfaces) lead to longer initial response times and longer edit times. The findings demonstrate the importance of providing pilots with interfaces that facilitate their ability to get back "in the loop."

  5. UAS Integration in the NAS Project: Part Task 6 V & V Simulation: Primary Results

    NASA Technical Reports Server (NTRS)

    Rorie, Conrad; Fern, Lisa; Shively, Jay; Santiago, Confesor

    2016-01-01

    This is a presentation of the preliminary results on final V and V (Verification and Validation) activity of [RTCA (Radio Technical Commission for Aeronautics)] SC (Special Committee)-228 DAA (Detect and Avoid) HMI (Human-Machine Interface) requirements for display alerting and guidance.

  6. UAS Integration into the NAS: iHTL: DAA Display Evaluation Preliminary Results

    NASA Technical Reports Server (NTRS)

    Fern, Lisa; Rorie, Conrad; Shively, Jay

    2014-01-01

    The integrated human-in-the-loop (iHITL) simulation examined the effect of four different Detect-and-Avoid (DAA) display concepts on unmanned aircraft system (UAS) pilots' ability to maintain safe separation. The displays varied in the type and amount of guidance they provided to pilots. The study's background and methodology are discussed, followed by a presentation of the preliminary 'measured response' data (i.e., pilots' end-to-end response time in reacting to traffic alerts on their DAA display). Results indicate that display type had moderate to no affect on pilot measured response times.

  7. The Washington Alphabet Circa 1895-1905: NAS, USGS, SI, WAS, CC, GWMA, WMI, CIW

    NASA Astrophysics Data System (ADS)

    Yochelson, E. L.

    2002-05-01

    Pursuit of science as part of the Federal responsibility to the American public was vigorously defended by John Wesley Powell in the 1880s, but received serious financial setback during the next decade. The following decade saw the gradual laying of foundations for the present-day non-academic component of "big science" through the development of a series of Federal and private organizations, some which were ephemeral. A key person in this alphabet soup has the initials CDW (Charles Doolittle Walcott). His influence will be discussed and if time permits, BM, NACA and NRC will be used to demonstrate methodology.

  8. UAS Integration in the NAS Project Test Site Kick-off Meeting

    NASA Technical Reports Server (NTRS)

    Kopardekar, Parimal; Witzberger, Kevin; Hackenberg, Davis L.; Murphy, Jim

    2015-01-01

    This briefing was presented during the Test Site Kick Off Meeting to discuss the contract awards for Task 1 and Task 2. This briefing covered a high level overview for contract deliverables, Task 1 - UAS Traffic Management and Task 2, Live Virtual Constructive Distributed Environment.

  9. Materials Data on NaS2 (SG:122) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  10. Automated Generation of Message-Passing Programs: An Evaluation of CAPTools using NAS Benchmarks

    NASA Technical Reports Server (NTRS)

    Hribar, Michelle R.; Jin, Hao-Qiang; Yan, Jerry C.; Bailey, David (Technical Monitor)

    1998-01-01

    Scientists at NASA Ames Research Center have been developing computational aeroscience applications on highly parallel architectures over the past ten years. During the same time period, a steady transition of hardware and system software also occurred, forcing us to expand great efforts into migrating and receding our applications. As applications and machine architectures continue to become increasingly complex, the cost and time required for this process will become prohibitive. Various attempts to exploit software tools to assist and automate the parallelization process have not produced favorable results. In this paper, we evaluate an interactive parallelization tool, CAPTools, for parallelizing serial versions of the NAB Parallel Benchmarks. Finally, we compare the performance of the resulting CAPTools generated code to the hand-coded benchmarks on the Origin 2000 and IBM SP2. Based on these results, a discussion on the feasibility of automated parallelization of aerospace applications is presented along with suggestions for future work.

  11. A Family of Well-Clear Boundary Models for the Integration of UAS in the NAS

    NASA Technical Reports Server (NTRS)

    Munoz, Cesar A.; Narkawicz, Anthony; Chamberlain, James; Consiglio, Maria; Upchurch, Jason

    2014-01-01

    The FAA-sponsored Sense and Avoid Workshop for Unmanned Aircraft Systems (UAS) defines the concept of sense and avoid for remote pilots as "the capability of a UAS to remain well clear from and avoid collisions with other airborne traffic." Hence, a rigorous definition of well clear is fundamental to any separation assurance concept for the integration of UAS into civil airspace. This paper presents a family of well-clear boundary models based on the TCAS II Resolution Advisory logic. For these models, algorithms that predict well-clear violations along aircraft current trajectories are provided. These algorithms are analogous to conflict detection algorithms but instead of predicting loss of separation, they predict whether well-clear violations will occur during a given lookahead time interval. Analytical techniques are used to study the properties and relationships satisfied by the models.

  12. Analysis of Well-Clear Boundary Models for the Integration of UAS in the NAS

    NASA Technical Reports Server (NTRS)

    Upchurch, Jason M.; Munoz, Cesar A.; Narkawicz, Anthony J.; Chamberlain, James P.; Consiglio, Maria C.

    2014-01-01

    The FAA-sponsored Sense and Avoid Workshop for Unmanned Aircraft Systems (UAS) defnes the concept of sense and avoid for remote pilots as "the capability of a UAS to remain well clear from and avoid collisions with other airborne traffic." Hence, a rigorous definition of well clear is fundamental to any separation assurance concept for the integration of UAS into civil airspace. This paper presents a family of well-clear boundary models based on the TCAS II Resolution Advisory logic. Analytical techniques are used to study the properties and relationships satisfied by the models. Some of these properties are numerically quantifed using statistical methods.

  13. Support of Activities of the NAS in Relation to the Radiation Effects Research Foundation

    SciTech Connect

    Douple, Evan B.

    2006-05-31

    The National Academies (NA) provides support for the activities related to the long-term follow up of the health of the survivors of the atomic bombings of Hiroshima and Nagasaki being conducted by the Radiation Effects Research Foundation (RERF) laboratories in Hiroshima and Nagasaki, Japan. The NA serves as scientific and administrative liaison between the U.S. Department of Energy (DOE) and RERF, and performs tasks in the areas of scientific oversight, information/public interface, fiscal oversight, and personnel management. The project includes recruitment and support of approximately 10 NA employees who work at RERF in Japan. Specific activities are performed consistent with the cooperative agreement’s Statement of Work between DOE and NA and consistent with an Annual Work Plan developed by DOE and NA.

  14. UAS Integration in the NAS Project: DAA-TCAS Interoperability "mini" HITL Primary Results

    NASA Technical Reports Server (NTRS)

    Rorie, Conrad; Fern, Lisa; Shively, Jay; Santiago, Confesor

    2016-01-01

    At the May 2015 SC-228 meeting, requirements for TCAS II interoperability became elevated in priority. A TCAS interoperability workgroup was formed to identify and address key issues/questions. The TCAS workgroup came up with an initial list of questions and a plan to address those questions. As part of that plan, NASA proposed to run a mini HITL to address display, alerting and guidance issues. A TCAS Interoperability Workshop was held to determine potential display/alerting/guidance issues that could be explored in future NASA mini HITLS. Consensus on main functionality of DAA guidance when TCAS II RA occurs. Prioritized list of independent variables for experimental design. Set of use cases to stress TCAS Interoperability.

  15. 76 FR 1511 - Amendment of Class D Airspace; Fort Worth NAS JRB (Carswell Field), TX

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-11

    ...'' under DOT Regulatory Policies and Procedures (44 FR 11034; February 26, 1979); and (3) does not warrant... read as follows: Authority: 49 U.S.C. 106(g), 40103, 40113, 40120; E. O. 10854, 24 FR 9565, 3 CFR, 1959... navigation aids, at the request of the U.S. Navy, that are listed in the description. This action does...

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

    NASA Technical Reports Server (NTRS)

    Chung, William; Chachad, Girish; Hochstetler, Ronald

    2016-01-01

    The Integrated Gate Turnaround Management (IGTM) concept was developed to improve the gate turnaround performance at the airport by leveraging relevant historical data to support optimization of airport gate operations, which include: taxi to the gate, gate services, push back, taxi to the runway, and takeoff, based on available resources, constraints, and uncertainties. By analyzing events of gate operations, primary performance dependent attributes of these events were identified for the historical data analysis such that performance models can be developed based on uncertainties to support descriptive, predictive, and prescriptive functions. A system architecture was developed to examine system requirements in support of such a concept. An IGTM prototype was developed to demonstrate the concept using a distributed network and collaborative decision tools for stakeholders to meet on time pushback performance under uncertainties.

  17. BOREAS TE-9 In Situ Diurnal Gas Exchange of NAS Boreal Forest Stands

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Curd, Shelaine (Editor); Margolis, Hank; Coyea, Marie; Dang, Qinglai

    2000-01-01

    The BOREAS TE-9 team collected several data sets related to chemical and photosynthetic properties of leaves in boreal forest tree species. The purpose of the BOREAS TE-09 study was threefold: 1) to provide in situ gas exchange data that will be used to validate models of photosynthetic responses to light, temperature, and carbon dioxide (CO2); 2) to compare the photosynthetic responses of different tree crown levels (upper and lower); and 3) to characterize the diurnal water potential curves for these sites to get an indication of the extent to which soil moisture supply to leaves might be limiting photosynthesis. The gas exchange data of the BOREAS NSA were collected to characterize diurnal gas exchange and water potential of two canopy levels of five boreal canopy cover types: young jack pine, old jack pine, old aspen, lowland old black spruce, and upland black spruce. These data were collected between 27-May-1994 and 17-Sep-1994. The data are provided in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  18. NATIONAL ACADEMY OF SCIENCES (NAS) REVIEW OF THE HEALTH IMPLICATIONS OF PERCHLORATE INGESTION (2005)

    EPA Science Inventory

    In the interest of resolving scientific questions, the EPA, the Department of Defense, the Department of Energy, and the National Aeronautics and Space Administration - members of a broader Interagency Working Group on Perchlorate led by the Office of Science and Technology Polic...

  19. Preliminary C3 Loading Analysis for Future High-Altitude Unmanned Aircraft in the NAS

    NASA Technical Reports Server (NTRS)

    Ho, Yan-Shek; Gheorghisor, Izabela; Box, Frank

    2006-01-01

    This document provides a preliminary assessment and summary of the command, control, and communications (C(sup 3)) loading requirements of a generic future high-altitude, long-endurance unmanned aircraft (UA) operating at in the National Airspace System. Two principal types of C(sup 3) traffic are considered in our analysis: communications links providing air traffic services (ATS) to the UA and its human pilot, and the command and control data links enabling the pilot to operate the UA remotely. we have quantified the loading requirements of both types of traffic for two different assumed levels of UA autonomy. Our results indicate that the potential use of UA-borne relays for the ATS links, and the degree of autonomy exercised by the UA during the departure and arrival phases of its flight, will be among the key drivers of C(sup 3) loading and bandwidth requirements.

  20. Implementation of BT, SP, LU, and FT of NAS Parallel Benchmarks in Java

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    A number of Java features make it an attractive but a debatable choice for High Performance Computing. We have implemented benchmarks working on single structured grid BT,SP,LU and FT in Java. The performance and scalability of the Java code shows that a significant improvement in Java compiler technology and in Java thread implementation are necessary for Java to compete with Fortran in HPC applications.

  1. Estudo de não gaussianidade nas anisotropias da RCF medidas Wmap

    NASA Astrophysics Data System (ADS)

    Andrade, A. P. A.; Wuensche, C. A.; Ribeiro, A. L. B.

    2003-08-01

    A investigação do campo de flutuações da Radiação Cósmica de Fundo (RCF) pode oferecer um importante teste para os modelos cosmológicos que descrevem a origem e a evolução das flutuações primordiais. De um lado, apresenta-se o modelo inflacionário que prevê um espectro de flutuações adiabáticas distribuídas segundo uma gaussiana e, de outro, os modelos de defeitos topológicos (dentre outros) que descrevem um mecanismo para a geração de flutuações de isocurvatura que obedecem a uma distribuição não gaussiana. Este trabalho tem como objetivo caracterizar traços do modelo não gaussiano de campo misto (entre flutuações adiabáticas e de isocurvatura) nos mapas do Wilkinson Microwave Anisotropy Probe (WMAP). Simulações das anisotropias da RCF no contexto de mistura indicam traços marcantes na distribuição das flutuações de temperatura, mesmo quando consideradas pequenas contribuições do campo de isocurvatura (da ordem de 0.001). O efeito da mistura entre os campos resulta na transferência de potência de flutuações em escalas angulares intermediárias para flutuações em pequenas escalas angulares. Este efeito pode ser caracterizado pela relação entre as amplitudes dos primeiros picos acústicos no espectro de potência da RCF. Neste trabalho, investigamos a contribuição do campo de isocurvatura, no contexto de mistura, sobre as observações recentes da RCF realizadas pelo WMAP. As previsões do modelo de campo misto, uma vez confrontadas com as observações em pequenas escalas angulares, podem ajudar a revelar a natureza das flutuações primordiais.

  2. Infrared transitions between hydrogenic states in GaInNAs/GaAs quantum wells

    NASA Astrophysics Data System (ADS)

    Al, E. B.; Ungan, F.; Yesilgul, U.; Kasapoglu, E.; Sari, H.; Sökmen, I.

    2016-08-01

    The effects of nitrogen and indium concentrations on the 1s, 2s, 2p0 and 2p±-like donor impurity energy states in a single Ga1‑xInxNyAs1‑y/GaAs quantum well (QW) are investigated by variational approach within the effective mass approximation. The results are presented as a function of the well width and the donor impurity position. It is found that the impurity binding and transition energies depend strongly on the indium concentration while depends weakly on the nitrogen concentration.

  3. Design of Unstructured Adaptive (UA) NAS Parallel Benchmark Featuring Irregular, Dynamic Memory Accesses

    NASA Technical Reports Server (NTRS)

    Feng, Hui-Yu; VanderWijngaart, Rob; Biswas, Rupak; Biegel, Bryan (Technical Monitor)

    2001-01-01

    We describe the design of a new method for the measurement of the performance of modern computer systems when solving scientific problems featuring irregular, dynamic memory accesses. The method involves the solution of a stylized heat transfer problem on an unstructured, adaptive grid. A Spectral Element Method (SEM) with an adaptive, nonconforming mesh is selected to discretize the transport equation. The relatively high order of the SEM lowers the fraction of wall clock time spent on inter-processor communication, which eases the load balancing task and allows us to concentrate on the memory accesses. The benchmark is designed to be three-dimensional. Parallelization and load balance issues of a reference implementation will be described in detail in future reports.

  4. Materials reliability. Technical activities, 1990. (NAS-NRC Assessment Panel, January 31-February 1, 1991)

    SciTech Connect

    McHenry, H.I.

    1990-12-01

    Selected Highlights of the Materials Reliability Division are as follows: Composites NDE: A high resolution ultrasonic system has been developed for inspecting thick polymer-matrix composites; NDE Instruments: Field trials were conducted on two prototype ultrasonic NDE instruments. A formability sensor system was delivered to the Ford Motor Company for evaluation at their Dearborn stamping plant. An ultrasonic system for roll-by inspection of railroad wheels is being evaluated at the American Association of Railroads test track in Pueblo, Colorado; Elastic Waves in Composites: A powerful technique using a time-dependent Green's function method has been developed for studying propagation of elastic waves and their scattering from discontinuities in anisotropic solids; Electronic Packaging: Computer programs have been developed to convert coordinate points on solder joint surfaces obtained by x-ray laminography and optical inspection into finite element meshes for stress analysis; Thermomechanical Processing: The continuous cooling transformation (CCT) characteristics and the high-temperature, high strain-rate flow properties were measured for microalloyed SAE 1141 forging steel; Charpy Standards: Over 1000 industrial customers were supplied with Charpy V-notch reference specimens and calibration services for certification of Charpy impact test machines to ASTM Standard E23; Cryogenic Testing: A 5 MN (1 million pound-force) servohydraulic testing machine was refurbished and equipped with a cryostat and dewar capable of testing specimens 2 m long and 50 cm in diameter in liquid helium; Aluminum-Lithium Alloys: A cooperative program with NASA indicated that aluminum-lithium alloys have sufficient oxygen compatibility for use in cryogenic tankage for the Advanced Launch System; Automated Welding: An intelligent welding program was initiated for the U.S. Navy in conjunction with Babcock and Wilcox and INEL.

  5. 48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... any contract changes. (d) The contracting officer will consider for monthly progress payments material... resident engineer. (4) Such materials and/or equipment will be protected against weather, theft and...

  6. 48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .../her bid and will not be binding as pertaining to any contract changes. (d) The contracting officer... equipment will be protected against weather, theft and other hazards and will not be subjected...

  7. NAS battery demonstration at American Electric Power:a study for the DOE energy storage program.

    SciTech Connect

    Newmiller, Jeff; Norris, Benjamin L. (Norris Energy Consulting Company, Martinez, CA); Peek, Georgianne Huff

    2006-03-01

    The first U.S. demonstration of the NGK sodium/sulfur battery technology was launched in August 2002 when a prototype system was installed at a commercial office building in Gahanna, Ohio. American Electric Power served as the host utility that provided the office space and technical support throughout the project. The system was used to both reduce demand peaks (peak-shaving operation) and to mitigate grid power disturbances (power quality operation) at the demonstration site. This report documents the results of the demonstration, provides an economic analysis of a commercial sodium/sulfur battery energy storage system at a typical site, and describes a side-by-side demonstration of the capabilities of the sodium/sulfur battery system, a lead-acid battery system, and a flywheel-based energy storage system in a power quality application.

  8. Buracos negros primordiais e astrofísica observacional

    NASA Astrophysics Data System (ADS)

    Custódio, P. S.; Horvath, J. E.

    2003-02-01

    A história da física contemporânea é pródiga em grandes descobertas (a Relatividade e a Mecânica Quântica entre as mais importantes) até meados dos anos '30. O peso destes desenvolvimentos é tão grande que outros feitos de grande porte (por exemplo, a teoria da nucleossíntese nas estrelas) são geralmente considerados como "filhotes" dos primeiros, ao menos na imaginação popular. Porém, algumas exceções à regra não-escrita são dignas de menção. Entre estas últimas está a descoberta por S.W.Hawking e colaboradores das propriedades de emissão dos buracos negros, trabalho que iniciou uma disciplina com vida própria denominada Termodinâmica de Buracos Negros.

  9. 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

    ... was announced in a May 21, 2010, Federal Register Notice (75 FR 28610). EPA also announced that it..., 2010, Federal Register Notice (75 FR 28805). Members of the public who wish to ensure that their... comment period for review of this draft assessment was announced previously in the Federal Register (75...

  10. Defects in Ga(In)NAs thin films grown by atomic H-assisted molecular beam epitaxy

    SciTech Connect

    Shimizu, Yukiko; Mura, Yusuke; Uedono, Akira; Okada, Yoshitaka

    2006-09-15

    The vacancy-type defects in Ga{sub 1-y}In{sub y}N{sub x}As{sub 1-x} dilute nitride films grown by atomic H-assisted molecular beam epitaxy (H-MBE) were investigated. The positron annihilation measurements showed that the densities of vacancy-type defects in GaN{sub x}As{sub 1-x} (x=0%-1.3%) films grown under an optimized atomic H flux were as low as that for a liquid encapsulated Czochralski (LEC) GaAs substrate. Further, the influence of vacancy-type defects on the crystal quality and optical properties were studied by x-ray diffraction and photoluminescence (PL) measurements. The integrated PL intensity at 77 K drastically decreased as N composition was increased, but we found no clear correlation between the density or volume of vacancy defects and optical properties, and the S parameters were nearly constant at a value of {approx}0.516 in all Ga{sub 1-y}In{sub y}N{sub x}As{sub 1-x} films grown by our H-MBE technique.

  11. Effect of nitrogen fraction on the temperature dependence of GaNAs/GaAs quantum-well emission

    NASA Astrophysics Data System (ADS)

    Potter, R. J.; Balkan, N.; Carrère, H.; Arnoult, A.; Bedel, E.; Marie, X.

    2003-05-01

    The effects of nitrogen fraction on the temperature dependence of GaNxAs1-x/GaAs (x<2.8%) quantum-well emission was investigated using steady-state photoluminescence between 2 and 300 K. At low temperatures, a characteristic S-shape behavior indicative of carrier localization was observed for each of the samples. This is believed to result from the large miscibility gap induced by the nitrogen, which results in structural/compositional fluctuations in the well. In the high temperature regime (T>150 K) where the emission has a linear dependence, a strong reduction in emission temperature dependence was observed with increasing nitrogen. The temperature dependence was modeled using the band anticrossing approach, with the interaction matrix element parameter CNM (VMN=-CMN√x ) and the nitrogen level parameter γ (EN=EN0-γx) used as fitting parameters.

  12. UAS Integration into the NAS: Detect and Avoid Display Evaluations in Support of SC-228 MOPS Development

    NASA Technical Reports Server (NTRS)

    Fern, Lisa; Rorie, Conrad; Shively, Jay

    2016-01-01

    At the May 2015 SC-228 meeting, requirements for TCAS II interoperability became elevated in priority. A TCAS interoperability work group was formed to identify and address key issuesquestions. The TCAS work group came up with an initial list of questions and a plan to address those questions. As part of that plan, NASA proposed to run a mini HITL to address display, alerting and guidance issues. A TCAS Interoperability Workshop was held to determine potential displayalertingguidance issues that could be explored in future NASA mini HITLS. Consensus on main functionality of DAA guidance when TCAS II RA occurs. Prioritized list of independent variables for experimental design. Set of use cases to stress TCAS Interoperability.

  13. NAS Experiences of Porting CM Fortran Codes to HPF on IBM SP2 and SGI Power Challenge

    NASA Technical Reports Server (NTRS)

    Saini, Subhash

    1995-01-01

    Current Connection Machine (CM) Fortran codes developed for the CM-2 and the CM-5 represent an important class of parallel applications. Several users have employed CM Fortran codes in production mode on the CM-2 and the CM-5 for the last five to six years, constituting a heavy investment in terms of cost and time. With Thinking Machines Corporation's decision to withdraw from the hardware business and with the decommissioning of many CM-2 and CM-5 machines, the best way to protect the substantial investment in CM Fortran codes is to port the codes to High Performance Fortran (HPF) on highly parallel systems. HPF is very similar to CM Fortran and thus represents a natural transition. Conversion issues involved in porting CM Fortran codes on the CM-5 to HPF are presented. In particular, the differences between data distribution directives and the CM Fortran Utility Routines Library, as well as the equivalent functionality in the HPF Library are discussed. Several CM Fortran codes (Cannon algorithm for matrix-matrix multiplication, Linear solver Ax=b, 1-D convolution for 2-D datasets, Laplace's Equation solver, and Direct Simulation Monte Carlo (DSMC) codes have been ported to Subset HPF on the IBM SP2 and the SGI Power Challenge. Speedup ratios versus number of processors for the Linear solver and DSMC code are presented.

  14. 75 FR 28610 - Draft EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ... report. In addition, it includes new analyses on potential human effects that may result from exposure to... under EPA's Integrated Risk Information System (IRIS) program, and thus, the new IRIS process announced... Advisory Board (SAB), a body established under the Federal Advisory Committee Act, for independent...

  15. A Comparison of Automatic Parallelization Tools/Compilers on the SGI Origin 2000 Using the NAS Benchmarks

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

    Porting applications to new high performance parallel and distributed computing platforms is a challenging task. Since writing parallel code by hand is extremely time consuming and costly, porting codes would ideally be automated by using some parallelization tools and compilers. In this paper, we compare the performance of the hand written NAB Parallel Benchmarks against three parallel versions generated with the help of tools and compilers: 1) CAPTools: an interactive computer aided parallelization too] that generates message passing code, 2) the Portland Group's HPF compiler and 3) using compiler directives with the native FORTAN77 compiler on the SGI Origin2000.

  16. The Helios Prototype flying wing stretches almost the full length of the 300-foot-long hangar at NAS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Helios Prototype flying wing stretches almost the full length of the 300-foot-long hangar at NASA's Dryden flight Research Center, Edwards, California. The 247-foot span solar-powered aircraft, resting on its ground maneuvering dolly, was on display for a visit of NASA Administrator Sean O'Keefe and other NASA officials on January 31, 2002. The unique solar-electric flying wing reached an altitude of 96,863 feet during an almost 17-hour flight near Hawaii on August 13, 2001, a world record for sustained horizontal flight by a non-rocket powered aircraft. Developed by AeroVironment, Inc., under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project, the Helios Prototype is the forerunner of a planned fleet of slow-flying, long duration, high-altitude uninhabited aerial vehicles (UAV) which can serve as 'atmospheric satellites,' performing Earth science missions or functioning as telecommunications relay platforms in the stratosphere.

  17. A biometric latent curve analysis of memory decline in older men of the NAS-NRC twin registry.

    PubMed

    McArdle, John J; Plassman, Brenda L

    2009-09-01

    Previous research has shown cognitive abilities to have different biometric patterns of age-changes. We examined the variation in episodic memory (word recall task) for over 6,000 twin pairs who were initially aged 59-75, and were subsequently re-assessed up to three more times over 12 years. In cross-sectional analyses, variation in the number of words recalled independent of age was explained largely by non-shared influences (65-72%), with clear additive genetic influences (12-32%), and marginal shared family influences (1-18%). The longitudinal phenotypic analysis of the word recall task showed systematic linear declines over age, but several nonlinear models with more dramatic changes at later ages, improved the overall fit. A two-part spline model for the longitudinal twin data with an optimal turning point at age 74 led to: (a) a separation of non-shared environmental influences and transient measurement error (~50%); (b) strong additive genetic components of this latent curve (~44% at age 60) with increases (over 50%) up to age 74, but with no additional genetic variation after age 74; (c) the smaller influences of shared family environment (~15% at age 74) were constant over all ages; (d) non-shared effects play an important role over most of the life-span but diminish after age 74.

  18. Método numérico das diferenças finitas no domínio do tempo aplicado a ondas Alfvén em plasma astrofísico

    NASA Astrophysics Data System (ADS)

    Dos Santos, L. C.; Kintopp, J. A.; Jatenco-Pereira, V.; Opher, R.

    2003-08-01

    Ondas Alfvén em plasma astrofísico têm sido objeto de intenso estudo nas últimas décadas pelo fato de apresentarem papel importante em muitas áreas de pesquisa na astrofísica. Particularmente são importantes no mecanismo de aquecimento da coroa solar; em ventos estelares; em jatos galácticos e extragalácticos; em discos protoestelares, etc. A formulação para diferenças finitas no domínio do tempo (FDTD), aplicada a plasma magnetizado é desenvolvida para estudo das propriedades de ondas Alfvén em três dimensões (3D-FDTD). O método é aplicado inicialmente a um plasma homogêneo e isotérmico imerso em uma região com campo magnético externo B0, que sofre uma pequena perturbação. Uma vez gerada a onda, esta perturbação é retirada e, então analisamos a evolução temporal das ondas, bem como a forma de seu amortecimento.

  19. Sobre a atividade pós-periélica do cometa de órbita parabólica Yanaka (1988r)

    NASA Astrophysics Data System (ADS)

    de Almeida, A. A.; Sanzovo, G. C.; Boczko, R.

    2003-08-01

    Greenberg, Singh & de Almeida (ApJ, 414: L45-48, 1993) mostraram que a deficiência nas abundâncias observadas de C2 e CN no Cometa Yanaka (1988r) pode ser explicada em termos das propriedades dos seus componentes refratários orgânicos, além do fato que trata-se de um cometa dinamicamente novo, observado através de abertura de fenda pequena projetada muito próximo do núcleo. Neste trabalho, complementamos o estudo sobre a atividade deste cometa de órbita parabólica, através da determinação da lei de potência que exprime sua taxa de produção de H2O (o principal indicador de atividade) na fase pós-periélica, determinamos o raio nuclear efetivo mínimo com sua fração de área ativa e analisamos a emissão de partículas de poeira observadas no contínuo em 625,0 nm.

  20. Health assessment for NAS-Whidbey Island (Seaplane Base), Oak Harbor, Island County, Washington, Region 10. CERCLIS No. WA6170090058. Preliminary report

    SciTech Connect

    Not Available

    1989-01-19

    The Naval Air Station-Whidbey Island Seaplane Base site is on the National Priorities List. The site is one of four major areas of Whidbey Island in Puget Sound belonging to the U.S. Navy. The environmental contamination on-site consists of chromium (75 ppb), and lead (21 ppb) in surface water; cadmium (40 ppb), chromium (31 ppb), and lead (32 ppb) in ground water; polychlorinated biphenyls (9 ppm), fluorene (25 ppm) and lead (280 ppm) in soil; arsenic (170 ppm), cadmium (58 ppm), nickel (200 ppm), lead (1,000 ppm), chromium (88 ppb), zinc (570 ppb), pyrene (2 ppm), and fluoranthene (2.4 ppm) in sediment. The site is considered to be of potential public health concern because of the risk to human health caused by the possibility of exposure to hazardous substances via ground water, surface water, soil, sediment, and shellfish.

  1. UAS-NAS Live Virtual Constructive Distributed Environment (LVC): LVC Gateway, Gateway Toolbox, Gateway Data Logger (GDL), SaaProc Software Design Description

    NASA Technical Reports Server (NTRS)

    Jovic, Srboljub

    2015-01-01

    This document provides the software design description for the two core software components, the LVC Gateway, the LVC Gateway Toolbox, and two participants, the LVC Gateway Data Logger and the SAA Processor (SaaProc).

  2. Review of the NAS/NRC report: {open_quotes}Groundwater at Yucca Mountain: How high can it rise?{close_quotes}. Special report No. 1

    SciTech Connect

    Archambeau, C.B.

    1992-12-01

    There are three basic and serious problems that produce disagreement with the conclusions and recommendations of the Academy report entitled {open_quotes}Groundwater at Yucca Mountain: How high can it rise?{close_quotes}. These are: First, the report ignores a considerable body of critical data relating to the ages and nature of hydrothermal alterations at the site; second, many of the strong conclusions expressed in the report are not reasonably supported by the evidence presented and, in some cases, are inconsistent with data and results available to the committee but which are not cited or used by them; and finally, there are statements describing field relationships and data that are not consistent with the facts or are made in such a way as to be misleading.

  3. Pratt & Whitney/Boeing Engine Validation of Noise Reduction Concepts Final Report for NASA Contract NAS3-97144, Phase 2

    NASA Technical Reports Server (NTRS)

    Bock, Larry A.; Hauser, Joseph E.; Mathews, Douglas C.; Topol, David A.; Bielak, Gerald W.; Lan, Justin H.; Premo, John W.

    2014-01-01

    This report presents results of the work completed in Phase 2 of the Engine Validation of Noise Reduction Concepts (EVNRC) contract. The purpose of the program is to validate, through engine testing, advanced noise reduction concepts aimed at reducing engine noise up to 6 EPNdB and improving nacelle suppression by 50 percent relative to 1992 technology. Phase 1 of the program is completed and is summarized in NASA/CR-2014-218088.

  4. Teaching of Astronomy at Teresa Martin College. (Breton Title: Ensino de Astronomia Nas Faculdades Teresa Martin.) Enseñanza de la Astronomia en la Facultad Teresa Martin

    NASA Astrophysics Data System (ADS)

    Azevedo Sobreira, Paulo Henrique

    2005-12-01

    Courses with exclusive Astronomy contents did not exist at (FATEMA) Teresa Martin College's program until the end of 2002. In 2001, a series of educational experiments started in courses and classes of Astronomy at Mathematics and Geography departments. This actions culminated with the insertion of Teaching of Astronomy as a study theme in the course of Independent Studies for Mathematics professors in 2005. Até o final de 2002 inexistiam na grade curricular das Faculdades Integradas Teresa Martin (FATEMA) cadeiras com conteúdos exclusivos de Astronomia. A partir do ano de 2001 iniciou-se uma série de experiências educacionais através de modelos de cursos e de aulas de Astronomia nos Departamentos de Matemática e de Geografia, o que culminou com a inserção do Ensino de Astronomia como temática da disciplina de Estudos Independentes para o curso de Licenciatura em Matemática, em 2005. Hasta el final de 2002 no había en el currículo dela Facultad TeresaMartín (FATEMA) en San Pablo - SP, Brasil, disciplinas con contenidos exclusivos de Astronomía. A partir del año 2001 comenzó una secuencia de experimentos educacionales de carrera y de clases de Astronomía en los Departamentos de Matemática y Geografía, culminando en la implantación de clases de Enseñanza dela Astronomíaenla Licenciaturaen Matemática, en el año de 2003, y de la cátedra de extensión en Cosmografía parala Licenciaturaen Geografía.

  5. Carriers confinement study of GaNAsBi/GaAs QWs emitting at 1.3 and 1.55 μm

    SciTech Connect

    Ben Nasr, A.; Habchi, M. M.; Bilel, C.; Rebey, A. El Jani, B.

    2015-05-15

    Band structures of GaN{sub 0.58y}As{sub 1–1.58y}Bi{sub y}/GaAs quantum wells (QWs) were studied using the band anticrossing model and the envelope function approximation. The confined states energies and the oscillator strengths of interband transitions were determined for well widths L{sub W} and Bi composition y varying in the range of 4–10 nm and 0–0.07 respectively. The emissions 1.3 and 1.55 μm were reached for specific couples (L{sub W}, y). The band anticrossing effect on the in-plane carriers effective mass has been investigated at k = 0. The absorbance spectra were calculated for QWs operating at 1.3 and 1.55 μm.

  6. Ventos em supergigantes B[e] das nuvens de Magalhães e da Galáxia

    NASA Astrophysics Data System (ADS)

    de Araújo, F. X.; Pilling, D. A.; Pereira, C. B.; Fernandes, M. B.

    2003-08-01

    As Supergigantes B[e] apresentam as seguintes características: (i) alta luminosidade; (ii) espectro típico de estrelas de tipo B; (iii) linhas permitidas e proibidas em emissão de metais de baixa ionização, especialmente FeII; (iv) linhas de Balmer, e por vêzes também dos ions HeI e FeII, com perfis tipo P Cygni indicativos de altas taxas de perda de massa. Atualmente estamos desenvolvendo um projeto que visa comparar as propriedades fisicas (principalmente e v¥) dos ventos destes objetos nas Nuvens de Magalhães e na Galaxia. O objetivo é estudar a influência da metalicidade. No presente painel apresentamos uma determinação das velocidades terminais de 11 estrelas, sendo 4 na GNM (Hen S111, 66, R126 e Hen S93), 4 na PNM (Hen S18, S23, S65 e R4) e 3 na Galaxia (CPD-529243, MWC 300 e GG Car). Nossos dados são espectros de alta resolução obtidos no telescópio 1.52m do ESO com o espectrógrafo FEROS. Para determinar as velocidades terminais usamos as linhas Hd e HeI 3888 Å cujas componentes em absorção costumam estar livres de "blends" e estruturas. Nossos resultados sugerem que as velocidades de expansão na GNM são maiores (ainda que apenas ligeiramente) do que aquelas da PNM, como esperado. No entanto, os objetos da Galaxia não parecem seguir a mesma tendência.

  7. Nitrogen Oxyanion-dependent Dissociation of a Two-component Complex That Regulates Bacterial Nitrate Assimilation*

    PubMed Central

    Luque-Almagro, Victor M.; Lyall, Verity J.; Ferguson, Stuart J.; Roldán, M. Dolores; Richardson, David J.; Gates, Andrew J.

    2013-01-01

    Nitrogen is an essential nutrient for growth and is readily available to microbes in many environments in the form of ammonium and nitrate. Both ions are of environmental significance due to sustained use of inorganic fertilizers on agricultural soils. Diverse species of bacteria that have an assimilatory nitrate/nitrite reductase system (NAS) can use nitrate or nitrite as the sole nitrogen source for growth when ammonium is limited. In Paracoccus denitrificans, the pathway-specific two-component regulator for NAS expression is encoded by the nasT and nasS genes. Here, we show that the putative RNA-binding protein NasT is a positive regulator essential for expression of the nas gene cluster (i.e. nasABGHC). By contrast, a nitrogen oxyanion-binding sensor (NasS) is required for nitrate/nitrite-responsive control of nas gene expression. The NasS and NasT proteins co-purify as a stable heterotetrameric regulatory complex, NasS-NasT. This protein-protein interaction is sensitive to nitrate and nitrite, which cause dissociation of the NasS-NasT complex into monomeric NasS and an oligomeric form of NasT. NasT has been shown to bind the leader RNA for nasA. Thus, upon liberation from the complex, the positive regulator NasT is free to up-regulate nas gene expression. PMID:24005668

  8. A Pos-Graduacao Nas Ciencias Humanas e o Paradigma da Medicina: A Era da Especializacao. (Post-Graduation in the Human Sciences and the Paradigm of Medicine: The Era of Specialization.)

    ERIC Educational Resources Information Center

    Costa, Celio Juvenal

    2000-01-01

    Reflects on the current tendency in Brazilian higher education for greater and greater specialization, particularly in human sciences and in medicine. Calls for less specialization and a more historic and general preparation, especially in teacher education. (BT)

  9. Ground Software Maintenance Facility (GSMF) user's manual. Appendices NASA-CR-178806 NAS 1.26:178806 Rept-41849-G159-026-App HC A05/MF A01

    NASA Technical Reports Server (NTRS)

    Aquila, V.; Derrig, D.; Griffith, G.

    1986-01-01

    Procedures are presented that allow the user to assemble tasks, link, compile, backup the system, generate/establish/print display pages, cancel tasks in memory, and to TET an assembly task without having to enter the commands every time. A list of acronyms is provided. Software identification, payload checkout unit operating system services, data base generation, and MITRA operating procedures are also discussed.

  10. [Guía latinoamericana para el diagnóstico y tratamiento de alergia a las proteínas de la leche de vaca (GL-APLV)].

    PubMed

    Montijo-Barrios, Ericka; López-Ugalde, Martha Verónica; Ramírez-Mayans, Jaime; Anaya-Flórez, María Salomé; Arredondo-García, José Luis; Azevedo-Tenorio, Isaac; Bacarreza-Nogales, Dante; Bautista-Silva, Miriam G; Cáceres-Cano, Pablo Andrés; Cáceres-Mendoza, César Augusto; Cadena-León, José Francisco; Cadranel, Samy; Carbajal-Rodríguez, Luis; Castillo-de-León, Yolanda A; Cázares-Méndez, Josefina Monserrat; Cervantes-Bustamante, Roberto; Colindres-C, Ediltrudys; Cossío-Ochoa, Enna Alicia; Chanis-Águila, Ricardo; Chávez-Barrera, José Antonio; Escobar-Castro, Héctor; Fernández-Aragón, Marlon; Fernández-Carrocera, Luis Alberto; Flores, Alejandro; Flores-Calderón, Judith; Galaz-Pantoja, Manuel Enrique; García-Dávila, Marycruz; Heller-Rouassant, Solange; Hernández-Bautista, Víctor Manuel; Higuera-Benítez, Jorge; Huerta-Hernández, Rosa Elena; Huerta-López, José G; Jovel-Banegas, Luis Enrique; Larrosa-Haro, Alfredo; Leal-Quevedo, Francisco Javier; León-Ramírez, Carlos; Limón-Rojas, Ana Elena; Lozano-Sáenz, José Santos; Mariño-Forero, Álvaro Eduardo; Márquez-Aguirre, Martha Patricia; Maruy-Saito, Aldo; Méndez-Nieto, Carlos Mario; Menéndez-Sandoval, José Fernando; Merlos-Fernández, Ivonne Guadalupe; Michel-Aceves, Reynaldo de Jesús; Michel-Penichet, Fernando; Munguía-Venegas, Pedro; Murillo-Márquez, Pedro; Navarro-A, Dianora C; Noronha-Spolidoro, José Vicente; Núñez-Barrera, Isela; Ordaz-Ortiz, Carlos Reyes; Ortega-Martell, José Antonio; Ortiz-López-de-Wyss, Ana Caroliona; Ovando-Fonseca, Jesús Elías; Oyervides-García, Carlos Iván; Palacios-Rosales, Jorge; Pinzón-Navarro, Adriana Beatriz; Quevedo-B, Rafael; Quito-Riera, Bolívar; Ramírez-Ortiz, Flor de María; Rivera-Medina, Juan; Romero-Trujillo, Jorge O; Sabra, Aderbal; Sáez-de-Ocariz-Gutiérrez, María Del Mar; Sánchez-Ortega, Analissa; Sánchez-Pérez, Maira Patricia; Sarmiento-Quintero, Fernando; Serrano-Sierra, Alejandro; Suárez-Cortina, Lucrecia; Tormo-Carnicé, Ramón; Toro-Monjaraz, Erick; Urquidi-Rivera, Martha Eugenia; Vásconez, Fabián; Vera, Fernando; Worona-Dibner, Liliana Beatriz; Zablah-Córdova, Roberto; Zamora-Dávila, Eduardo; Zárate-Mondragón, Flora

    2014-08-01

    Cow's milk allergy (CMA) is an immune-based disease that has become an increasing problem. The diagnosis and management of CMA varies from one clinical setting to another and represents a challenge in pediatric practice. In addition, because nonallergic food reactions can be confused with CMA symptoms, there is an overdiagnosis of the disease. In response to these situations, pediatric specialties from recognized institutions throughout Latin America decided to develop a clinical guideline for diagnosis and management of cow's milk allergy. These guidelines include definitions, epidemiology, pathophysiology overview, clinical and evidencebased recommendations for the diagnosis and treatment of CMA. They also include prevention and prognosis sections and identify gaps in the current knowledge to be addressed through future research.

  11. Cloning and characterization of the nicotianamine synthase gene in Eruca vesicaria subsp sativa.

    PubMed

    Huang, B L; Cheng, C; Zhang, G Y; Su, J J; Zhi, Y; Xu, S S; Cai, D T; Zhang, X K; Huang, B Q

    2015-12-22

    Nicotianamine (NA) is a ubiquitous metabolite in plants that bind heavy metals, is crucial for metal homeostasis, and is also an important metal chelator that facilitates long-distance metal transport and sequestration. NA synthesis is catalyzed by the enzyme nicotianamine synthase (NAS). Eruca vesicaria subsp sativa is highly tolerant to Ni, Pb, and Zn. In this study, a gene encoding EvNAS was cloned and characterized in E. vesicaria subsp sativa. The full-length EvNAS cDNA sequence contained a 111-bp 5'-untranslated region (UTR), a 155-bp 3'-UTR, and a 966-bp open reading frame encoding 322-amino acid residues. The EvNAS genomic sequence contained no introns, which is similar to previously reported NAS genes. The deduced translation of EvNAS contained a well-conserved NAS domain (1-279 amino acids) and an LIKI-CGEAEG box identical to some Brassica NAS and to the LIRL-box in most plant NAS, which is essential for DNA binding. Phylogenetic analysis indicated that EvNAS was most closely related to Brassica rapa NAS3 within the Cruciferae, followed by Thlaspi NAS1, Camelina NAS3, and Arabidopsis NAS3. A reverse transcription-polymerase chain reaction indicated that EvNAS expression was greatest in the leaves, followed by the flower buds and hypocotyls. EvNAS was moderately expressed in the roots.

  12. Cloning and characterization of the nicotianamine synthase gene in Eruca vesicaria subsp sativa.

    PubMed

    Huang, B L; Cheng, C; Zhang, G Y; Su, J J; Zhi, Y; Xu, S S; Cai, D T; Zhang, X K; Huang, B Q

    2015-01-01

    Nicotianamine (NA) is a ubiquitous metabolite in plants that bind heavy metals, is crucial for metal homeostasis, and is also an important metal chelator that facilitates long-distance metal transport and sequestration. NA synthesis is catalyzed by the enzyme nicotianamine synthase (NAS). Eruca vesicaria subsp sativa is highly tolerant to Ni, Pb, and Zn. In this study, a gene encoding EvNAS was cloned and characterized in E. vesicaria subsp sativa. The full-length EvNAS cDNA sequence contained a 111-bp 5'-untranslated region (UTR), a 155-bp 3'-UTR, and a 966-bp open reading frame encoding 322-amino acid residues. The EvNAS genomic sequence contained no introns, which is similar to previously reported NAS genes. The deduced translation of EvNAS contained a well-conserved NAS domain (1-279 amino acids) and an LIKI-CGEAEG box identical to some Brassica NAS and to the LIRL-box in most plant NAS, which is essential for DNA binding. Phylogenetic analysis indicated that EvNAS was most closely related to Brassica rapa NAS3 within the Cruciferae, followed by Thlaspi NAS1, Camelina NAS3, and Arabidopsis NAS3. A reverse transcription-polymerase chain reaction indicated that EvNAS expression was greatest in the leaves, followed by the flower buds and hypocotyls. EvNAS was moderately expressed in the roots. PMID:26782459

  13. Artificial sweeteners induce glucose intolerance by altering the gut microbiota.

    PubMed

    Suez, Jotham; Korem, Tal; Zeevi, David; Zilberman-Schapira, Gili; Thaiss, Christoph A; Maza, Ori; Israeli, David; Zmora, Niv; Gilad, Shlomit; Weinberger, Adina; Kuperman, Yael; Harmelin, Alon; Kolodkin-Gal, Ilana; Shapiro, Hagit; Halpern, Zamir; Segal, Eran; Elinav, Eran

    2014-10-01

    Non-caloric artificial sweeteners (NAS) are among the most widely used food additives worldwide, regularly consumed by lean and obese individuals alike. NAS consumption is considered safe and beneficial owing to their low caloric content, yet supporting scientific data remain sparse and controversial. Here we demonstrate that consumption of commonly used NAS formulations drives the development of glucose intolerance through induction of compositional and functional alterations to the intestinal microbiota. These NAS-mediated deleterious metabolic effects are abrogated by antibiotic treatment, and are fully transferrable to germ-free mice upon faecal transplantation of microbiota configurations from NAS-consuming mice, or of microbiota anaerobically incubated in the presence of NAS. We identify NAS-altered microbial metabolic pathways that are linked to host susceptibility to metabolic disease, and demonstrate similar NAS-induced dysbiosis and glucose intolerance in healthy human subjects. Collectively, our results link NAS consumption, dysbiosis and metabolic abnormalities, thereby calling for a reassessment of massive NAS usage.

  14. Ultra Performance Liquid Chromatography Ion Mobility Time-of-Flight Mass Spectrometry Characterization of Naphthenic Acids Species from Oil Sands Process-Affected Water.

    PubMed

    Huang, Rongfu; McPhedran, Kerry N; Gamal El-Din, Mohamed

    2015-10-01

    Ultraperformance liquid chromatography ion mobility time-of-flight mass spectrometry (UPLC-IM-TOFMS), integrating traveling wave ion mobility spectrometry (TWIMS) with negative electrospray ionization (ESI) mode, was used to achieve two-dimensional (2D) separation (drift vs retention times) of naphthenic acids (NAs). Unprocessed and ozonated commercial NAs were used for method development. Only O2-NAs were found in unprocessed NAs with ozonation creating O3-NAs and O4-NAs. Unprocessed and ozonated oil sands process-affected waters (OSPW) were examined to validate the method for complex matrix NAs. Ozonation increased the x number for Ox-NAs (2 ≤ x ≤ 5) and also impacted the -Z number distribution. OSPW extracted using dichloromethane removed the potential for sample matrix impacts and was used for MS/MS NAs characterization. The Ox-NAs (2 ≤ x ≤ 6) were identified with O2-NAs separated into three clusters indicating isobaric and isomeric species. MS/MS was used to verify compounds, while also indicating the presence of CH3CH2S- NAs groups. This result may be useful for future studies of sulfur-NAs fate, toxicity, and treatment. Overall, the value-added information provided by UPLC-IM-TOFMS makes it a promising analytical technique for analysis of NAs in complex OSPW samples. Moreover, this methodology can be used for other matrices to investigate relative molecular sizes and to separate complex species (e.g., fatty acids, lipids), making it beneficial for environmental and bioanalytical applications.

  15. Occurrences and behaviors of naphthenic acids in a petroleum refinery wastewater treatment plant.

    PubMed

    Wang, Beili; Wan, Yi; Gao, Yingxin; Zheng, Guomao; Yang, Min; Wu, Song; Hu, Jianying

    2015-05-01

    Naphthenic acids (NAs) are one class of compounds in wastewaters from petroleum industries that are known to cause toxic effects, and their removal from oilfield wastewater is an important challenge for remediation of large volumes of petrochemical effluents. The present study investigated occurrences and behaviors of total NAs and aromatic NAs in a refinery wastewater treatment plant, located in north China, which combined physicochemical and biological processes. Concentrations of total NAs were semiquantified to be 113-392 μg/L in wastewater from all the treatment units, and the percentages of aromatic NAs in total NAs was estimated to be 2.1-8.8%. The mass reduction for total NAs and aromatic NAs was 15±16% and 7.5±24% after the physicochemical treatment, respectively. Great mass reduction (total NAs: 65±11%, aromatic NAs: 86±5%) was observed in the biological treatment units, and antiestrogenic activities observed in wastewater from physicochemical treatment units disappeared in the effluent of the activated sludge system. The distributions of mass fractions of NAs demonstrated that biodegradation via activated sludge was the major mechanism for removing alicyclic NAs, aromatic NAs, and related toxicities in the plant, and the polycyclic NA congener classes were relatively recalcitrant to biodegradation, which is a complete contrast to the preferential adsorption of NAs with higher cyclicity (low Z value). Removal efficiencies of total NAs were 73±17% in summer, which were higher than those in winter (53±15%), and the seasonal variation was possibly due to the relatively high microbial biotransformation activities in the activated sludge system in summer (indexed by O3-NAs/NAs). The results of the investigations indicated that biotransformation of NA mixtures by the activated sludge system were largely affected by temperature, and employing an efficient adsorbent together with biodegradation processes would help cost-effectively remove NAs in petroleum

  16. Nicotianamine synthase specifically expressed in root nodules of Lotus japonicus.

    PubMed

    Hakoyama, T; Watanabe, H; Tomita, J; Yamamoto, A; Sato, S; Mori, Y; Kouchi, H; Suganuma, N

    2009-07-01

    In dicotyledonous plants, nicotianamine synthase (NAS) is thought to play a role in the intercellular transport of iron (Fe). Fe is an essential metal for nitrogen-fixing root nodules of legumes, prompting us to characterize the role of the NAS gene in detail. We previously compared gene-expression profiles in ineffective nodules formed on a Lotus japonicus Fix(-) mutant, sen1, with those in wild-type-effective nodules, and showed that expression of an expressed sequence tag (EST) clone encoding an NAS (EC 2.5.1.43) homologue was repressed in the ineffective nodules. In the present study, two EST clones encoding NAS homologues were found in the EST database. We named them LjNAS1 and LjNAS2. Both were detected as single-copy genes in the L. japonicus genome, and conferred NAS activities in transformed Saccharomyces cerevisiae. LjNAS2 was expressed only in nodules, but LjNAS1 was expressed mainly in leaves, stems, and cotyledons. The level of LjNAS2 transcripts was highest in the nodules 24 days after inoculation with Mesorhizobium loti, and was localized in vascular bundles within the nodules. Expression of LjNAS2 was suppressed in ineffective nodules formed on Fix(-) mutants other than sen1. By contrast, nitrogenase activities of nodules were not influenced in LjNAS2-suppressed plants. We discuss the role of LjNAS2 from the aspect of Fe translocation in nodules.

  17. Ames Director William 'Bill' Ballhaus (center left) joins visitor Sir Jeffrey Pope from Royla

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Ames Director William 'Bill' Ballhaus (center left) joins visitor Sir Jeffrey Pope from Royla Aircraft Industry, England (center right) at the NAS Facility Cray 2 computer with Ron Deiss, NAS Deputy Manager (L) and Vic Peterson, Ames Deputy Director (R).

  18. Reading: Students' Attitudes and Interests in Fourth, Fifth, and Sixth Grades in Official Portuguese Schools in the USA (A Leitura: Atitudes e Preferencias dos Educandos do 4th, 5th, e 6th Anos de Escolaridade nas Escolas Oficiais Portuguesas nos Estados Unidos da America).

    ERIC Educational Resources Information Center

    Castanho, Maria da Graca Borges

    A study investigated attitudes and preferences concerning reading among fourth-, fifth-, and sixth-grade students in Portuguese-language schools in the United States. Extrinsic factors influencing students (parents, teachers) were also analyzed. The research took place in 10 schools in 5 states. Data were obtained using questionnaires (students)…

  19. O Passado como Nacao: Imagens do Imperio nas Falas Reacionarias dos Anos 30 e 40 do Seculo XX: Uma Pequena Arqueologia do Debate Publico e Privado (The Past as Nation: Images of the Empire in the Reactionary Words of the 30s and 40s in the 20th Century: A Small Archaeology of the Public Debate versus the Private One).

    ERIC Educational Resources Information Center

    de Freitas, Marcos Cezar

    1998-01-01

    Suggests an archaeology of the public debate versus the private one in Brazil through analysis of the reactionary speech of a religious leader, Dom Jose Mauricio da Rocha, which produced innumerable representations of the Brazilian Empire. (PA)

  20. Developmental toxicity and endocrine disruption of naphthenic acids on the early life stage of zebrafish (Danio rerio).

    PubMed

    Wang, Jie; Cao, Xiaofeng; Huang, Yi; Tang, Xiaoyan

    2015-12-01

    Oil sands process-affected water (OSPW) has been reported to exhibit adverse effects on the environment and wildlife. Although the compounds responsible are unknown, naphthenic acids (NAs) have been considered to be implicated. The current study was designed to investigate whether NAs might cause developmental toxicity and endocrine disruption on the early life stage of zebrafish (Danio rerio). The success of embryo hatch was inhibited by 2.5 mg l(-1) oil sands NAs (OS-NAs) exposure, and both OSPW NAs and commercial NAs (C-NAs) exposure resulted in a variety of developmental lesions in the fish larvae, such as yolk sac edema, pericardial edema and spinal malformation. The transcription of genes involved cytochrome P450 aromatase (CYP19a and CYP19b), estrogen receptors (ERα, ERβ1 and ERβ2), and vitellogenin (VTG) was analyzed to evaluate the endocrine disrupting effects of NAs. Significant up-regulated gene expressions of CYP19b, ERα and VTG were observed in both OS-NAs and C-NAs groups, which indicated the deleteriously estrogenic potential of NAs. These results confirmed that NAs derived from crude petroleum could negatively impact the development and endocrine function of zebrafish, and be primarily responsible for the toxicity of OSPW.

  1. 75 FR 30825 - Draft Toxicological Review of Formaldehyde in Support of Summary Information on the Integrated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-02

    ... NAS peer review meetings, one or more NAS meetings may take place before the close of EPA's public... provide all public ] comments to the NAS at least 5 working days before the meeting date announced on the..., they should also submit written comments at least 5 working days before the meeting date announced...

  2. Developmental toxicity and endocrine disruption of naphthenic acids on the early life stage of zebrafish (Danio rerio).

    PubMed

    Wang, Jie; Cao, Xiaofeng; Huang, Yi; Tang, Xiaoyan

    2015-12-01

    Oil sands process-affected water (OSPW) has been reported to exhibit adverse effects on the environment and wildlife. Although the compounds responsible are unknown, naphthenic acids (NAs) have been considered to be implicated. The current study was designed to investigate whether NAs might cause developmental toxicity and endocrine disruption on the early life stage of zebrafish (Danio rerio). The success of embryo hatch was inhibited by 2.5 mg l(-1) oil sands NAs (OS-NAs) exposure, and both OSPW NAs and commercial NAs (C-NAs) exposure resulted in a variety of developmental lesions in the fish larvae, such as yolk sac edema, pericardial edema and spinal malformation. The transcription of genes involved cytochrome P450 aromatase (CYP19a and CYP19b), estrogen receptors (ERα, ERβ1 and ERβ2), and vitellogenin (VTG) was analyzed to evaluate the endocrine disrupting effects of NAs. Significant up-regulated gene expressions of CYP19b, ERα and VTG were observed in both OS-NAs and C-NAs groups, which indicated the deleteriously estrogenic potential of NAs. These results confirmed that NAs derived from crude petroleum could negatively impact the development and endocrine function of zebrafish, and be primarily responsible for the toxicity of OSPW. PMID:25995127

  3. Pluralizing the Monoculture

    ERIC Educational Resources Information Center

    Balch, Stephen H.

    2007-01-01

    The National Association of Scholars (NAS) is now entering its twentieth year. The organization has grown over ten-fold since their national launch. When NAS made its debut, today's extensive infrastructure for higher education reform did not yet exist. In this article, the author discusses the contributions of NAS to the academe. The author also…

  4. Intrinsic Job Satisfaction, Overall Satisfaction, and Intention to Leave the Job among Nursing Assistants in Nursing Homes

    ERIC Educational Resources Information Center

    Decker, Frederic H.; Harris-Kojetin, Lauren D.; Bercovitz, Anita

    2009-01-01

    Purpose: We examined predictors of intrinsic job satisfaction, overall satisfaction, and intention to leave the job among nursing assistants (NAs). Design and Methods: The study focused on NAs who worked 30 or more hours per week in a nursing home. Data on 2,146 NAs meeting this criterion came from the 2004 National Nursing Assistant Survey, the…

  5. Fractionation of oil sands-process affected water using pH-dependent extractions: a study of dissociation constants for naphthenic acids species.

    PubMed

    Huang, Rongfu; Sun, Nian; Chelme-Ayala, Pamela; McPhedran, Kerry N; Changalov, Mohamed; Gamal El-Din, Mohamed

    2015-05-01

    The fractionation of oil sands process-affected water (OSPW) via pH-dependent extractions was performed to quantitatively investigate naphthenic acids (NAs, CnH2n+ZO2) and oxidized NAs (Ox-NAs) species (CnH2n+ZO3 and CnH2n+ZO4) using ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOFMS). A mathematical model was also developed to estimate the dissociation constant pKa for NAs species, considering the liquid-liquid extraction process and the aqueous layer acid-base equilibrium. This model provides estimated dissociation constants for compounds in water samples based on fractionation extraction and relative quantification. Overall, the sum of O2-, O3-, and O4-NAs species accounted for 33.6% of total extracted organic matter. Accumulative extracted masses at different pHs revealed that every oxygen atom added to NAs increases the pKa (i.e., O2-NAsNAsNAs), indicating that the additional O atoms exist as -OH in O3- and O4-NAs. Molecule electron-withdrawing groups such as double bonds and aromatic groups, as indicated by higher carbon and -Z number, may be responsible for the lower pKa of O2-, O3-, and O4-NAs. The model obtained estimated pKa values of 3.5 for O2-NAs, 4.8 for O3-NAs, and 6.8 for O4-NAs via nonlinear regression curve fittings. These pKa values are valuable physicochemical parameters for environmental engineering applications targeting OSPW NAs treatment.

  6. Naphthenic acids inhibit root water transport, gas exchange and leaf growth in aspen (Populus tremuloides) seedlings.

    PubMed

    Kamaluddin, M; Zwiazek, Janusz J

    2002-12-01

    Effects of sodium naphthenates (NAs) on root hydraulic conductivity (Lp) and gas exchange processes were examined in aspen (Populus tremuloides Michx.) seedlings grown in solution culture. Exposure of roots to NAs for 3-5 weeks significantly decreased Lp and stomatal conductance. Root-absorbed NAs also decreased leaf chlorophyll concentration, net photosynthesis and leaf growth. Short-term (< or = 2 h) exposure of excised roots to NAs significantly decreased root water flow (Qv) with a concomitant decline in root respiration. We conclude that NAs metabolically inhibited Lp, likely by affecting water channel activity, and that this inhibition could be responsible for the observed reductions in gas exchange and leaf growth.

  7. Diversity and Detection of Nitrate Assimilation Genes in Marine Bacteria

    PubMed Central

    Allen, Andrew E.; Booth, Melissa G.; Frischer, Marc E.; Verity, Peter G.; Zehr, Jonathan P.; Zani, Sabino

    2001-01-01

    A PCR approach was used to construct a database of nasA genes (called narB genes in cyanobacteria) and to detect the genetic potential for heterotrophic bacterial nitrate utilization in marine environments. A nasA-specific PCR primer set that could be used to selectively amplify the nasA gene from heterotrophic bacteria was designed. Using seawater DNA extracts obtained from microbial communities in the South Atlantic Bight, the Barents Sea, and the North Pacific Gyre, we PCR amplified and sequenced nasA genes. Our results indicate that several groups of heterotrophic bacterial nasA genes are common and widely distributed in oceanic environments. PMID:11679368

  8. Nonpharmacologic Management of Neonatal Abstinence Syndrome: An Integrative Review.

    PubMed

    Edwards, Lindy; Brown, Lisa F

    2016-01-01

    Neonatal abstinence syndrome (NAS) affects 3.39 in every 1,000 live births. A literature review was conducted to determine the varying types of nonpharmacologic management being used currently and its effect on the treatment of NAS symptoms. Fourteen articles were found that used nonpharmacologic management in the treatment of NAS. Therapies included breastfeeding, positioning, rooming-in, acupuncture/acupressure, and beds. Each of the nonpharmacologic therapies in these articles, with the exception of rocking beds, was shown to have a positive effect on the newborn with NAS. These effects include a shorter length of stay, a decrease in NAS scores, a decrease need for pharmacologic treatment, less agitation, a better quality of sleep, and a decrease in the severity of NAS symptoms. This review article shows that nonpharmacologic management is an effective tool for NAS symptom treatment. PMID:27636695

  9. Digestion of Nucleic Acids Starts in the Stomach

    PubMed Central

    Liu, Yu; Zhang, Yanfang; Dong, Ping; An, Ran; Xue, Changhu; Ge, Yinlin; Wei, Liangzhou; Liang, Xingguo

    2015-01-01

    The ingestion of nucleic acids (NAs) as a nutritional supplement or in genetically modified food has attracted the attention of researchers in recent years. Discussions over the fate of NAs led us to study their digestion in the stomach. Interestingly, we found that NAs are digested efficiently by human gastric juice. By performing digests with commercial, recombinant and mutant pepsin, a protein-specific enzyme, we learned that the digestion of NAs could be attributed to pepsin rather than to the acidity of the stomach. Further study showed that pepsin cleaved NAs in a moderately site-specific manner to yield 3′-phosphorylated fragments and the active site to digest NAs is probably the same as that used to digest protein. Our results rectify the misunderstandings that the digestion of NAs in the gastric tract begins in the intestine and that pepsin can only digest protein, shedding new light on NA metabolism and pepsin enzymology. PMID:26168909

  10. Digestion of Nucleic Acids Starts in the Stomach.

    PubMed

    Liu, Yu; Zhang, Yanfang; Dong, Ping; An, Ran; Xue, Changhu; Ge, Yinlin; Wei, Liangzhou; Liang, Xingguo

    2015-07-14

    The ingestion of nucleic acids (NAs) as a nutritional supplement or in genetically modified food has attracted the attention of researchers in recent years. Discussions over the fate of NAs led us to study their digestion in the stomach. Interestingly, we found that NAs are digested efficiently by human gastric juice. By performing digests with commercial, recombinant and mutant pepsin, a protein-specific enzyme, we learned that the digestion of NAs could be attributed to pepsin rather than to the acidity of the stomach. Further study showed that pepsin cleaved NAs in a moderately site-specific manner to yield 3'-phosphorylated fragments and the active site to digest NAs is probably the same as that used to digest protein. Our results rectify the misunderstandings that the digestion of NAs in the gastric tract begins in the intestine and that pepsin can only digest protein, shedding new light on NA metabolism and pepsin enzymology.

  11. Ultra Performance Liquid Chromatography Ion Mobility Time-of-Flight Mass Spectrometry Characterization of Naphthenic Acids Species from Oil Sands Process-Affected Water.

    PubMed

    Huang, Rongfu; McPhedran, Kerry N; Gamal El-Din, Mohamed

    2015-10-01

    Ultraperformance liquid chromatography ion mobility time-of-flight mass spectrometry (UPLC-IM-TOFMS), integrating traveling wave ion mobility spectrometry (TWIMS) with negative electrospray ionization (ESI) mode, was used to achieve two-dimensional (2D) separation (drift vs retention times) of naphthenic acids (NAs). Unprocessed and ozonated commercial NAs were used for method development. Only O2-NAs were found in unprocessed NAs with ozonation creating O3-NAs and O4-NAs. Unprocessed and ozonated oil sands process-affected waters (OSPW) were examined to validate the method for complex matrix NAs. Ozonation increased the x number for Ox-NAs (2 ≤ x ≤ 5) and also impacted the -Z number distribution. OSPW extracted using dichloromethane removed the potential for sample matrix impacts and was used for MS/MS NAs characterization. The Ox-NAs (2 ≤ x ≤ 6) were identified with O2-NAs separated into three clusters indicating isobaric and isomeric species. MS/MS was used to verify compounds, while also indicating the presence of CH3CH2S- NAs groups. This result may be useful for future studies of sulfur-NAs fate, toxicity, and treatment. Overall, the value-added information provided by UPLC-IM-TOFMS makes it a promising analytical technique for analysis of NAs in complex OSPW samples. Moreover, this methodology can be used for other matrices to investigate relative molecular sizes and to separate complex species (e.g., fatty acids, lipids), making it beneficial for environmental and bioanalytical applications. PMID:26322530

  12. Artificial sweeteners induce glucose intolerance by altering the gut microbiota.

    PubMed

    Suez, Jotham; Korem, Tal; Zeevi, David; Zilberman-Schapira, Gili; Thaiss, Christoph A; Maza, Ori; Israeli, David; Zmora, Niv; Gilad, Shlomit; Weinberger, Adina; Kuperman, Yael; Harmelin, Alon; Kolodkin-Gal, Ilana; Shapiro, Hagit; Halpern, Zamir; Segal, Eran; Elinav, Eran

    2014-10-01

    Non-caloric artificial sweeteners (NAS) are among the most widely used food additives worldwide, regularly consumed by lean and obese individuals alike. NAS consumption is considered safe and beneficial owing to their low caloric content, yet supporting scientific data remain sparse and controversial. Here we demonstrate that consumption of commonly used NAS formulations drives the development of glucose intolerance through induction of compositional and functional alterations to the intestinal microbiota. These NAS-mediated deleterious metabolic effects are abrogated by antibiotic treatment, and are fully transferrable to germ-free mice upon faecal transplantation of microbiota configurations from NAS-consuming mice, or of microbiota anaerobically incubated in the presence of NAS. We identify NAS-altered microbial metabolic pathways that are linked to host susceptibility to metabolic disease, and demonstrate similar NAS-induced dysbiosis and glucose intolerance in healthy human subjects. Collectively, our results link NAS consumption, dysbiosis and metabolic abnormalities, thereby calling for a reassessment of massive NAS usage. PMID:25231862

  13. Genetic control of nitrate assimilation in Klebsiella oxytoca. Final technical report

    SciTech Connect

    Stewart, Valley J.

    2001-04-01

    Some microorganisms can use nitrate as the sole source of nitrogen for biosynthesis. This project focused on the bacterium Klebsiella oxytoca, an enterobacterium found in soil and water. Mutagenesis and molecular cloning identified the nasFEDCBA operon encoding enzymes for the uptake and reduction of nitrate and nitrite to ammonium, and the adjacent nasR regulatory gene. Analysis of nasF operon expression revealed that transcription is activated by the Ntr (general nitrogen regulation ) system in response to nitrogen limitation. Transcription antitermination control in response to nitrate and nitrite is mediated by the NasR protein. Additional work established that the NasR protein is an RNA-binding protein that interacts with nasF operon leader RNA to control transcription readthrough.

  14. Three Dimensional Sculpturing of Vertical Nanowire Arrays by Conventional Photolithography.

    PubMed

    Shi, Run; Huang, Chengzi; Zhang, Linfei; Amini, Abbas; Liu, Kai; Shi, Yuan; Bao, Shuhan; Wang, Ning; Cheng, Chun

    2016-01-05

    Ordered nanoarchitectures have attracted an intense research interest recently because of their promising device applications. They are always fabricated by self-assembling building blocks such as nanowires, nanodots. This kind of bottom up approaches is limited in poor control over height, lateral resolution, aspect ratio, and patterning. Here, we break these limits and realize 3D sculpturing of vertical ZnO nanowire arrays (NAs) based on the conventional photolithography approach. These are achieved by immersing nanowire NAs in thick photoresist (PR) layers, which enable the cutting and patterning of ZnO NAs as well as the tailoring of NAs. Our strategy of 3D sculpturing of NAs promisingly paves the way for designing novel NAs-based nanoarchitectures.

  15. Three Dimensional Sculpturing of Vertical Nanowire Arrays by Conventional Photolithography

    NASA Astrophysics Data System (ADS)

    Shi, Run; Huang, Chengzi; Zhang, Linfei; Amini, Abbas; Liu, Kai; Shi, Yuan; Bao, Shuhan; Wang, Ning; Cheng, Chun

    2016-01-01

    Ordered nanoarchitectures have attracted an intense research interest recently because of their promising device applications. They are always fabricated by self-assembling building blocks such as nanowires, nanodots. This kind of bottom up approaches is limited in poor control over height, lateral resolution, aspect ratio, and patterning. Here, we break these limits and realize 3D sculpturing of vertical ZnO nanowire arrays (NAs) based on the conventional photolithography approach. These are achieved by immersing nanowire NAs in thick photoresist (PR) layers, which enable the cutting and patterning of ZnO NAs as well as the tailoring of NAs. Our strategy of 3D sculpturing of NAs promisingly paves the way for designing novel NAs-based nanoarchitectures.

  16. Three Dimensional Sculpturing of Vertical Nanowire Arrays by Conventional Photolithography

    PubMed Central

    Shi, Run; Huang, Chengzi; Zhang, Linfei; Amini, Abbas; Liu, Kai; Shi, Yuan; Bao, Shuhan; Wang, Ning; Cheng, Chun

    2016-01-01

    Ordered nanoarchitectures have attracted an intense research interest recently because of their promising device applications. They are always fabricated by self-assembling building blocks such as nanowires, nanodots. This kind of bottom up approaches is limited in poor control over height, lateral resolution, aspect ratio, and patterning. Here, we break these limits and realize 3D sculpturing of vertical ZnO nanowire arrays (NAs) based on the conventional photolithography approach. These are achieved by immersing nanowire NAs in thick photoresist (PR) layers, which enable the cutting and patterning of ZnO NAs as well as the tailoring of NAs. Our strategy of 3D sculpturing of NAs promisingly paves the way for designing novel NAs-based nanoarchitectures. PMID:26729069

  17. Mechanistic investigation of industrial wastewater naphthenic acids removal using granular activated carbon (GAC) biofilm based processes.

    PubMed

    Islam, Md Shahinoor; Zhang, Yanyan; McPhedran, Kerry N; Liu, Yang; Gamal El-Din, Mohamed

    2016-01-15

    Naphthenic acids (NAs) found in oil sands process-affected waters (OSPW) have known environmental toxicity and are resistant to conventional wastewater treatments. The granular activated carbon (GAC) biofilm treatment process has been shown to effectively treat OSPW NAs via combined adsorption/biodegradation processes despite the lack of research investigating their individual contributions. Presently, the NAs removals due to the individual processes of adsorption and biodegradation in OSPW bioreactors were determined using sodium azide to inhibit biodegradation. For raw OSPW, after 28 days biodegradation and adsorption contributed 14% and 63% of NA removal, respectively. For ozonated OSPW, biodegradation removed 18% of NAs while adsorption reduced NAs by 73%. Microbial community 454-pyrosequencing of bioreactor matrices indicated the importance of biodegradation given the diverse carbon degrading families including Acidobacteriaceae, Ectothiorhodospiraceae, and Comamonadaceae. Overall, results highlight the ability to determine specific processes of NAs removals in the combined treatment process in the presence of diverse bacteria metabolic groups found in GAC bioreactors.

  18. Pharmacokinetics, biodistribution and metabolism of squalenoyl adenosine nanoparticles in mice using dual radio-labeling and radio-HPLC analysis

    PubMed Central

    Gaudin, Alice; Lepetre-Mouelhi, Sinda; Mougin, Julie; Parrod, Martine; Pieters, Grégory; Garcia-Argote, Sébastien; Loreau, Olivier; Goncalves, Jordan; Chacun, Hélène; Courbebaisse, Yann; Clayette, Pascal; Desmaële, Didier; Rousseau, Bernard; Andrieux, Karine; Couvreur, Patrick

    2015-01-01

    Adenosine is a pleiotropic endogenous nucleoside with potential neuroprotective pharmacological activity. However, clinical use of adenosine is hampered by its extremely fast metabolization. To overcome this limitation, we recently developed a new squalenoyl nanomedicine of adenosine [Squalenoyl-Adenosine (SQAd)] by covalent linkage of this nucleoside to the squalene, a natural lipid. The resulting nanoassemblies (NAs) displayed a dramatic pharmacological activity both in cerebral ischemia and spinal cord injury pre-clinical models. The aim of the present study was to investigate the plasma profile and tissue distribution of SQAd NAs using both Squalenoyl-[3H]-Adenosine NAs and [14C]-Squalenoyl-Adenosine NAs as respective tracers of adenosine and squalene moieties of the SQAd bioconjugate. This study was completed by radio-HPLC analysis allowing to determine the metabolization profile of SQAd. We report here that SQAd NAs allowed a sustained circulation of adenosine under its prodrug form (SQAd) for at least 1 h after intravenous administration, when free adenosine was metabolized within seconds after injection. Moreover, the squalenoylation of adenosine and its formulation as NAs also significantly modified biodistribution, as SQAd NAs were mainly captured by the liver and spleen, allowing a significant release of adenosine in the liver parenchyma. Altogether, these results suggest that SQAd NAs provided a reservoir of adenosine into the bloodstream which may explain the previously observed neuroprotective efficacy of SQAd NAs against cerebral ischemia and spinal cord injury. PMID:26087468

  19. Nucleic acid delivery into skin for the treatment of skin disease: Proofs-of-concept, potential impact, and remaining challenges.

    PubMed

    Zakrewsky, Michael; Kumar, Sunny; Mitragotri, Samir

    2015-12-10

    Nucleic acids (NAs) hold significant potential for the treatment of several diseases. Topical delivery of NAs for the treatment of skin diseases is especially advantageous since it bypasses the challenges associated with systemic administration which suffers from enzymatic degradation, systemic toxicity and lack of targeting to skin. However, the skin's protective barrier function limits the delivery of NAs into skin after topical application. Here, we highlight strategies for enhancing delivery of NAs into skin, and provide evidence that translation of topical NA therapies could have a transformative impact on the treatment of skin diseases.

  20. Pharmacokinetics, biodistribution and metabolism of squalenoyl adenosine nanoparticles in mice using dual radio-labeling and radio-HPLC analysis.

    PubMed

    Gaudin, Alice; Lepetre-Mouelhi, Sinda; Mougin, Julie; Parrod, Martine; Pieters, Grégory; Garcia-Argote, Sébastien; Loreau, Olivier; Goncalves, Jordan; Chacun, Hélène; Courbebaisse, Yann; Clayette, Pascal; Desmaële, Didier; Rousseau, Bernard; Andrieux, Karine; Couvreur, Patrick

    2015-08-28

    Adenosine is a pleiotropic endogenous nucleoside with potential neuroprotective pharmacological activity. However, clinical use of adenosine is hampered by its extremely fast metabolization. To overcome this limitation, we recently developed a new squalenoyl nanomedicine of adenosine [Squalenoyl-Adenosine (SQAd)] by covalent linkage of this nucleoside to the squalene, a natural lipid. The resulting nanoassemblies (NAs) displayed a dramatic pharmacological activity both in cerebral ischemia and spinal cord injury pre-clinical models. The aim of the present study was to investigate the plasma profile and tissue distribution of SQAd NAs using both Squalenoyl-[(3)H]-Adenosine NAs and [(14)C]-Squalenoyl-Adenosine NAs as respective tracers of adenosine and squalene moieties of the SQAd bioconjugate. This study was completed by radio-HPLC analysis allowing to determine the metabolization profile of SQAd. We report here that SQAd NAs allowed a sustained circulation of adenosine under its prodrug form (SQAd) for at least 1h after intravenous administration, when free adenosine was metabolized within seconds after injection. Moreover, the squalenoylation of adenosine and its formulation as NAs also significantly modified biodistribution, as SQAd NAs were mainly captured by the liver and spleen, allowing a significant release of adenosine in the liver parenchyma. Altogether, these results suggest that SQAd NAs provided a reservoir of adenosine into the bloodstream which may explain the previously observed neuroprotective efficacy of SQAd NAs against cerebral ischemia and spinal cord injury. PMID:26087468

  1. An integrated biochemical system for nitrate assimilation and nitric oxide detoxification in Bradyrhizobium japonicum.

    PubMed

    Cabrera, Juan J; Salas, Ana; Torres, María J; Bedmar, Eulogio J; Richardson, David J; Gates, Andrew J; Delgado, María J

    2016-02-01

    Rhizobia are recognized to establish N2-fixing symbiotic interactions with legume plants. Bradyrhizobium japonicum, the symbiont of soybeans, can denitrify and grow under free-living conditions with nitrate (NO3 (-)) or nitrite (NO2 (-)) as sole nitrogen source. Unlike related bacteria that assimilate NO3 (-), genes encoding the assimilatory NO3 (-) reductase (nasC) and NO2 (-) reductase (nirA) in B. japonicum are located at distinct chromosomal loci. The nasC gene is located with genes encoding an ABC-type NO3 (-) transporter, a major facilitator family NO3 (-)/NO2 (-) transporter (NarK), flavoprotein (Flp) and single-domain haemoglobin (termed Bjgb). However, nirA clusters with genes for a NO3 (-)/NO2 (-)-responsive regulator (NasS-NasT). In the present study, we demonstrate NasC and NirA are both key for NO3 (-) assimilation and that growth with NO3 (-), but not NO2 (-) requires flp, implying Flp may function as electron donor to NasC. In addition, bjgb and flp encode a nitric oxide (NO) detoxification system that functions to mitigate cytotoxic NO formed as a by-product of NO3 (-) assimilation. Additional experiments reveal NasT is required for NO3 (-)-responsive expression of the narK-bjgb-flp-nasC transcriptional unit and the nirA gene and that NasS is also involved in the regulatory control of this novel bipartite assimilatory NO3 (-)/NO2 (-) reductase pathway.

  2. Monitoring the Progress of New American Schools: A Description of Implementing Schools in a Longitudinal Sample.

    ERIC Educational Resources Information Center

    Berends, Mark; Heilbrunn, Jodi; McKelvey, Christopher; Sullivan, Thomas

    A private, nonprofit corporation, New American Schools (NAS) funds the development of designs aimed at transforming entire schools at the elementary and secondary levels. This report describes a large number of NAS sites in their early implementation stages. The report is the first in a series that monitors a longitudinal sample of schools…

  3. Implementation and Performance in New American Schools Three Years into Scale-Up.

    ERIC Educational Resources Information Center

    Berends, Mark; Kirby, Sheila Nataraj; Naftel, Scott; McKelvey, Christopher

    This progress interim report describes trends in implementation, school performance, and related factors for a sample of schools participating in the New American Schools (NAS) program. NAS is a program funding the development of designs aimed at transforming entire schools at the elementary and secondary levels. This evaluation focuses on the…

  4. Innate immune sensing of nucleic acids from mycobacteria.

    PubMed

    Yamashiro, Lívia Harumi; Oliveira, Sérgio Costa; Báfica, André

    2014-12-01

    Endosomal and cytosolic receptors engage recognition of mycobacterial-derived nucleic acids (MyNAs). In contrast, virulent mycobacteria may utilize nucleic acid recognition pathways to escape the host immune system. This short review will summarize the mechanisms by which MyNAs are sensed and how they influence host protective responses.

  5. MODEL SIMULATION STUDIES OF SCALE-DEPENDENT GAIN IN STREAM NUTRIENT ASSIMILATIVE CAPACITY RESULTING FROM IMPROVING NUTRIENT RETENTION METRICS

    EPA Science Inventory

    Considering the difficulty in measuring restoration success for nonpoint source pollutants, nutrient assimilative capacity (NAS) offers an attractive systems-based metric. Here NAS was defined using an impulse-response model of nitrate fate and transport. Eleven parameters were e...

  6. The USAF Phillips Laboratory sodium-sulfur battery technology program: Results and status

    NASA Technical Reports Server (NTRS)

    Rainbow, Marc E.; Somerville, Andrew

    1996-01-01

    Tests performed on NaS batteries are reported. The results of safety and abuse testing, shock and vibration tests, cell failure on warm-up, freeze thaw, overtemperature conditions, electrolyte fracture, overdischarge, and short circuit tests are presented along with GEO and LEO cycle tests and the status of the NaS cell flight tests.

  7. 75 FR 26739 - Notice of Intent To Prepare an Environmental Impact Statement (EIS) for Airfield Operations at...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-12

    ... Operations at Naval Air Station (NAS) Key West, FL and To Announce Public Scoping Meetings AGENCY: Department... at NAS Key West. The EIS will consider all reasonable alternatives to the proposed action, including the No Action Alternative. Dates and Addresses: Public scoping meetings will be held in Key...

  8. 78 FR 66904 - Notice of Availability of Record of Decision for Naval Air Station Key West Airfield Operations, FL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ... Department of the Navy Notice of Availability of Record of Decision for Naval Air Station Key West Airfield... (NAS) Key West by accomplishing the proposed action as set out in Alternative 2. Alternative 2 will... NAS Key West Airfield Operations, dated July 2013 and supporting documents. Single copies of the...

  9. 32 CFR 728.33 - Nonavailability statement (DD 1251).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of DEERS. Where this system is operational, it provides for transmitting quarterly reports to the... users should refer to their DEERS/NAS Users Manual for specific guidance on the use of the automated system. At activities where the DEER/NAS automated system is not operational, prepare each DD 1251...

  10. 32 CFR 728.33 - Nonavailability statement (DD 1251).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of DEERS. Where this system is operational, it provides for transmitting quarterly reports to the... users should refer to their DEERS/NAS Users Manual for specific guidance on the use of the automated system. At activities where the DEER/NAS automated system is not operational, prepare each DD 1251...

  11. 32 CFR 728.33 - Nonavailability statement (DD 1251).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of DEERS. Where this system is operational, it provides for transmitting quarterly reports to the... users should refer to their DEERS/NAS Users Manual for specific guidance on the use of the automated system. At activities where the DEER/NAS automated system is not operational, prepare each DD 1251...

  12. 76 FR 4743 - Agency Information Collection Activities: Requests for Comments; Clearance of Renewed Approval of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-26

    ... of Renewed Approval of Information Collection(s): NAS Data Release Request AGENCY: Federal Aviation... information collection. Background: This data collection is the genesis for granting approval to release filtered NAS data. The information provided sets the criteria for the FAA Data Release Request...

  13. 75 FR 57828 - Agency Information Collection Activities: Requests for Comments; Clearance of Renewed Approval of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-22

    ... of Renewed Approval of Information Collection: NAS Data Release Request AGENCY: Federal Aviation...: Renewal of an information collection. Background: This data collection is the genesis for granting approval to release filtered NAS data. The information provided sets the criteria for the FAA Data...

  14. The Novaco Anger Scale--Provocation Inventory (1994 Version) in Dutch Forensic Psychiatric Patients

    ERIC Educational Resources Information Center

    Hornsveld, Ruud H. J.; Muris, Peter; Kraaimaat, Floris W.

    2011-01-01

    We examined the psychometric properties of the Novaco Anger Scale--Provocation Inventory (NAS-PI, 1994 version) in Dutch violent forensic psychiatric patients and secondary vocational students. A confirmatory factor analysis of the subscale structure of the NAS was carried out, reliability was investigated, and relations were calculated between…

  15. Shifts in root-associated microbial communities of Typha latifolia growing in naphthenic acids and relationship to plant health.

    PubMed

    Phillips, Lori A; Armstrong, Sarah A; Headley, John V; Greer, Charles W; Germida, James J

    2010-01-01

    Naphthenic acids (NAs) are a complex mixture of organic acid compounds released during the extraction of crude oil from oil sands operations. The accumulation of toxic NAs in tailings pond water (TPW) is of significant environmental concern, and phytoremediation using constructed wetlands is one remediation option being assessed. Since root-associated microorganisms are an important factor during phytoremediation of organic compounds, this study investigated the impact of NAs on the microbial communities associated with the macrophyte Typha latifolia (cattail). Denaturing gradient gel electrophoresis revealed that the impact of NAs on microbial communities was niche dependent, with endophytic communities being the most stable and bulk water communities being the least stable. The type of NA used was significant to microbial response, with commercial NAs causing greater adverse changes than TPW NAs. In general, plant beneficial bacteria such as diazotrophs were favoured in cattails grown in TPW NAs, while potentially deleterious bacteria such as denitrifying Dechlorospirillum species increased in commercial NA treatments. These findings suggest that NAs may affect plant health by impacting root-associated microbial communities. A better understanding of these impacts may allow researchers to optimize those microbial communities that support plant health, and thus further optimize wetland treatment systems.

  16. Opioid neonatal abstinence syndrome: controversies and implications for practice.

    PubMed

    Wolff, Kim; Perez-Montejano, Raul

    2014-01-01

    The Opioid Neonatal Abstinence Syndrome (NAS) is a term used to describe a cluster of signs and symptoms seen in infants experiencing withdrawal from opioid drugs. Despite a substantial literature the relationship between maternal methadone dose, NAS and the method of assessment of NAS symptoms has not been agreed. The following review will address current and historical controversies surrounding these issues and will examine the evidence concerned with the evaluation of neonates exposed to methadone in utero. The key findings are as follows: A variety of NAS scales are used to assess the severity of neonatal withdrawal symptoms including locally adapted validated tools. Inconsistencies in the use of NAS scales have included the timing, duration and frequency of administration; the degree to which observers were trained to reliability; the use of NAS scales designed for term neonates to assess pre-term neonates who may have a qualitatively different expression of abstinence symptoms and; the research setting in which the tool was administered. There is a lack of research investigating the observant bias' effect upon scoring NAS, the basis for treatment decisions and the influence of concomitant maternal use of non-opioid drugs late in pregnancy. We also discuss the implications of the lack of recognition of NAS symptoms leading to possible under reporting and inappropriate, early neonatal discharge from hospital. In addition, this paper also discusses the merits and problems of conducting research in this area and highlights gaps in our knowledge and areas for further research.

  17. "What Does Bowdoin Teach"? A Dialogue between Wood and Klingenstein

    ERIC Educational Resources Information Center

    Wood, Peter; Klingenstein, Tom

    2013-01-01

    This article is an exchange of ideas between Peter Wood, President of the National Association of Scholars (NAS), and Tom Klingerstein, Chairman of the Claremont Institute and NAS Board Director, on the study "What Does Bowdoin Teach? How a Contemporary Liberal Arts College Shapes Students" (by Peter Wood and Michael Toscano). This…

  18. Decisionmaking, Transitions, and Resilient Futures

    SciTech Connect

    Moss, Richard H.; Lane, Meredith A.

    2012-08-01

    The article describes the focus of research in the social sciences on environmental change, describing studies on adaptation and mitigation. It is the first of 5 articles in the NAS quarterly journal IS&T on the occasion of the launch of a new Board at the NAS chaired by the author.

  19. 78 FR 54635 - Notice of Intent To Prepare an Environmental Impact Statement for EA-18G Growler Airfield...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-05

    ... operations at NAS Whidbey Island complex, which includes Ault Field and OLF Coupeville; (2) Add two new... Navy functions have been performed almost entirely at NAS Whidbey Island since 1971. With the... and functions at another location. In addition to the No Action Alternative, this EIS will assess...

  20. 41 CFR 102-3.180 - What does this subpart cover and how does it apply?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... by the National Academy of Sciences or the National Academy of Public Administration? § 102-3.180... to the agency by the National Academy of Sciences (NAS) or the National Academy of Public... Institute of Medicine, and the National Research Council. Except with respect to NAS committees that...

  1. The Predictive Validity of Infant Assessments in Rural Guatemala.

    ERIC Educational Resources Information Center

    Lasky, Robert E.; And Others

    1981-01-01

    The behavioral development of rural Guatemalan infants was assessed shortly after birth on a Neonatal Assessment Scale (NAS) and at 6-, 15-, and 24-months-of-age on a Composite Infant Scale (CIS). Summary variables based on NAS performance poorly predicted later assessed performance even as recently as six months after birth. The CIS modestly…

  2. 41 CFR 102-3.40 - What types of committees or groups are not covered by the Act and this part?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... or this Federal Advisory Committee Management part: (a) Committees created by the National Academy of Sciences (NAS) or the National Academy of Public Administration (NAPA). Any committee created by NAS or...; (b) Advisory committees of the Central Intelligence Agency and the Federal Reserve System....

  3. 41 CFR 102-3.40 - What types of committees or groups are not covered by the Act and this part?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... or this Federal Advisory Committee Management part: (a) Committees created by the National Academy of Sciences (NAS) or the National Academy of Public Administration (NAPA). Any committee created by NAS or...; (b) Advisory committees of the Central Intelligence Agency and the Federal Reserve System....

  4. 41 CFR 102-3.40 - What types of committees or groups are not covered by the Act and this part?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... or this Federal Advisory Committee Management part: (a) Committees created by the National Academy of Sciences (NAS) or the National Academy of Public Administration (NAPA). Any committee created by NAS or...; (b) Advisory committees of the Central Intelligence Agency and the Federal Reserve System....

  5. The Future of the National Association of Scholars

    ERIC Educational Resources Information Center

    Wood, Peter

    2012-01-01

    The National Association of Scholars (NAS) today is focused more than ever on public controversies and on public tools of communication. Where once NAS members were primarily concerned with debates within the academy, now they are equally concerned with debates about the academy. If the topics they address have changed, so too have the means by…

  6. An Analysis of the Effects of Net-Centric Operations Using Multi-Agent Adaptive Behavior

    ERIC Educational Resources Information Center

    Calderon-Meza, Guillermo

    2011-01-01

    The National Airspace System (NAS) is a resource managed in the public good. Equity in NAS access, and use for private, commercial and government purposes is coordinated by regulations and made possible by procedures, and technology. Researchers have documented scenarios in which the introduction of new concepts-of-operations and technologies has…

  7. Bold Plans for School Restructuring: The New American Schools Designs.

    ERIC Educational Resources Information Center

    Stringfield, Sam, Ed.; Ross, Steven, M., Ed.; Smith, Lana, Ed.

    In 1991, the New American Schools (NAS) Development Corporation was founded by a group of business and foundation leaders interested in investing in innovative designs for school transformation. This book describes the first 3 years of development and evaluation of 9 NAS whole-school restructuring designs. The designs were very diverse, as were…

  8. Relationship between Weather, Traffic and Delay Based on Empirical Methods

    NASA Technical Reports Server (NTRS)

    Sridhar, Banavar; Swei, Sean S. M.

    2006-01-01

    The steady rise in demand for air transportation over the years has put much emphasis on the need for sophisticated air traffic flow management (TFM) within the National Airspace System (NAS). The NAS refers to hardware, software and people, including runways, radars, networks, FAA, airlines, etc., involved in air traffic management (ATM) in the US. One of the metrics that has been used to assess the performance of NAS is the actual delays provided through FAA's Air Traffic Operations Network (OPSNET). The OPSNET delay data includes those reportable delays, i.e. delays of 15 minutes or more experienced by Instrument Flight Rule (IFR) flights, submitted by the FAA facilities. These OPSNET delays are caused by the application of TFM initiatives in response to, for instance, weather conditions, increased traffic volume, equipment outages, airline operations, and runway conditions. TFM initiatives such as, ground stops, ground delay programs, rerouting, airborne holding, and miles-in-trail restrictions, are actions which are needed to control the air traffic demand to mitigate the demand-capacity imbalance due to the reduction in capacity. Consequently, TFM initiatives result in NAS delays. Of all the causes, weather has been identified as the most important causal factor for NAS delays. Therefore, in order to accurately assess the NAS performance, it has become necessary to create a baseline for NAS performance and establish a model which characterizes the relation between weather and NAS delays.

  9. Fighting the "Damnable Triumph" of Feminism: Battles between Teachers' Unions in Interwar Britain

    ERIC Educational Resources Information Center

    Wilson, Dolly Smith

    2007-01-01

    The interwar decades saw a bitter recruiting war between the NUT (National Union of Teachers), the National Union of Women Teachers (NUWT), and the National Association of Schoolmasters (NAS), which like the NUWT broke away from the NUT in the early 1920s. The NAS opposed the NUT's official policy shift to support equal pay for male and female…

  10. 41 CFR 102-3.40 - What types of committees or groups are not covered by the Act and this part?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Sciences (NAS) or the National Academy of Public Administration (NAPA). Any committee created by NAS or... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What types of committees or groups are not covered by the Act and this part? 102-3.40 Section 102-3.40 Public Contracts...

  11. Making the Case for New Research to Support the Integration of Small Unmanned Aircraft Systems into the National Airspace System

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

    This paper describes the current state of sUAS regulation, their technical capabilities and the latest technologies that will allow for sUAS NAS integration. The research that is needed to demonstrate sUAS NAS integration capability is identified, and recommendations for conducting this necessary research are suggested.

  12. Giving Machines the Vision

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Amherst Systems manufactures foveal machine vision technology and systems commercially available to end-users and system integrators. This technology was initially developed under NASA contracts NAS9-19335 (Johnson Space Center) and NAS1-20841 (Langley Research Center). This technology is currently being delivered to university research facilities and military sites. More information may be found in www.amherst.com.

  13. Model development for naphthenic acids ozonation process.

    PubMed

    Al Jibouri, Ali Kamel H; Wu, Jiangning

    2015-02-01

    Naphthenic acids (NAs) are toxic constituents of oil sands process-affected water (OSPW) which is generated during the extraction of bitumen from oil sands. NAs consist mainly of carboxylic acids which are generally biorefractory. For the treatment of OSPW, ozonation is a very beneficial method. It can significantly reduce the concentration of NAs and it can also convert NAs from biorefractory to biodegradable. In this study, a factorial design (2(4)) was used for the ozonation of OSPW to study the influences of the operating parameters (ozone concentration, oxygen/ozone flow rate, pH, and mixing) on the removal of a model NAs in a semi-batch reactor. It was found that ozone concentration had the most significant effect on the NAs concentration compared to other parameters. An empirical model was developed to correlate the concentration of NAs with ozone concentration, oxygen/ozone flow rate, and pH. In addition, a theoretical analysis was conducted to gain the insight into the relationship between the removal of NAs and the operating parameters. PMID:25189805

  14. Building information modeling (BIM) approach to the GMT Project

    NASA Astrophysics Data System (ADS)

    Teran, Jose; Sheehan, Michael; Neff, Daniel H.; Adriaanse, David; Grigel, Eric; Farahani, Arash

    2014-07-01

    The Giant Magellan Telescope (GMT), one of several next generation Extremely Large Telescopes (ELTs), is a 25.4 meter diameter altitude over azimuth design set to be built at the summit of Cerro Campánas at the Las Campánas Observatory in Chile. The paper describes the use of Building Information Modeling (BIM) for the GMT project.

  15. The next accreditation system in radiology: a report from the APDR residency structure committee.

    PubMed

    Nicholson, Brandi T; Paladin, Angelisa M; Oldham, Sandra A; Hudson, Kathleen T; Weissman, Barbara N; Wissman, Robert D; Davis, Lawrence P; Reddy, Gautham P; Heitkamp, Darel E

    2014-04-01

    In a move to emphasize the educational outcomes of training programs, the ACGME has created the Next Accreditation System (NAS). The stated goals of NAS include aiding the ACGME in the accreditation of programs based on educational outcome measures, decreasing program burdens associated with the conventional process-based approach to ACGME accreditation, allowing good programs to innovate while enabling struggling programs to steadily improve, and providing public accountability for outcomes. Diagnostic radiology is among the first group of specialties to undergo NAS implementation and began operating under the NAS in July 2013. This article describes the various components of the NAS and explains the new elements, including the clinical learning environment review program, the milestones, the clinical competency committee, and the self-study visits.

  16. A study of mixed group-V nitrides grown by gas-source molecular beam epitaxy using a nitrogen radical beam source

    SciTech Connect

    Bi, W.G.; Tu, C.W.; Mathes, D.; Hull, R.

    1997-12-31

    The authors report a study of N incorporation in GaAs and InP by gas-source molecular beam epitaxy using a N radical beam source. For GaNAs grown at high temperatures, phase separation was observed, as evidenced from the formation of cubic GaN aside from GaNAs. By lowering the growth temperature, however, GaNAs alloys with N as high as 14.8% have been obtained without showing any phase separation. For InNP, no phase separation was observed in the temperature range studied (310--420 C). Contrary to GaNAs, incorporating N in InP is very difficult, with only less than 1% N being achieved. Optical absorption measurement reveals strong red shift of bandgap energy with direct-bandgap absorption. However, no semimetallic region seems to exist for GaNAs and a composition, dependent bowing parameter has been observed.

  17. Maternal opioid dose is associated with neonatal abstinence syndrome in children born to women with sickle cell disease.

    PubMed

    Shirel, Tyler; Hubler, Collin P; Shah, Rena; Mager, Amy B; Koch, Kathryn L; Sheth, Darshita; Uhing, Michael R; Jones, Cresta W; Field, Joshua J

    2016-06-01

    The objective of this study was to test the hypothesis that higher daily opioid dose is associated with the presence and severity of neonatal abstinence syndrome (NAS) in pregnant women with sickle cell disease (SCD). This was a retrospective study of pregnant women with SCD who required opioids. NAS was evaluated using the Finnegan scoring system and classified as none, mild, and severe. Severe NAS was defined as a Finnegan score ≥ 8 on 3 consecutive tests. Thirty-four pregnancies were examined in 30 women with SCD. Higher daily morphine dose was associated with a higher percentage of days in the hospital during pregnancy (P < 0.001). Hospital days contributed disproportionately to daily morphine dose as larger amounts of opioids were administered in the hospital compared to home (P = 0.002). Median maternal oral morphine dose was 416 mg for infants with severe NAS compared with 139 mg for those with mild NAS (P = 0.04). For infants with no NAS, median maternal morphine was 4 mg, significantly less than those with mild NAS (P < 0.001). Infants born to women who used on average >200 mg/day of oral morphine equivalent in the last month of pregnancy had a 13-fold increased risk of severe NAS compared with those who used <200 mg/day. These data demonstrate that higher median daily opioid dose is associated with progressively more severe NAS in pregnant women with SCD. Strategies to decrease pain and avoid hospitalizations are needed to reduce opioid use and NAS.

  18. Development of an Attitude Scale to Assess K-12 Teachers' Attitudes toward Nanotechnology

    NASA Astrophysics Data System (ADS)

    Lan, Yu-Ling

    2012-05-01

    To maximize the contributions of nanotechnology to this society, at least 60 countries have put efforts into this field. In Taiwan, a government-funded K-12 Nanotechnology Programme was established to train K-12 teachers with adequate nanotechnology literacy to foster the next generation of Taiwanese people with sufficient knowledge in nanotechnology. In the present study, the Nanotechnology Attitude Scale for K-12 teachers (NAS-T) was developed to assess K-12 teachers' attitudes toward nanotechnology. The NAS-T included 23 Likert-scale items that can be grouped into three components: importance of nanotechnology, affective tendencies in science teaching, and behavioural tendencies to teach nanotechnology. A sample of 233 K-12 teachers who have participated in the K-12 Nanotechnology Programme was included in the present study to investigate the psychometric properties of the NAS-T. The exploratory factor analysis of this teacher sample suggested that the NAS-T was a three-factor model that explained 64.11% of the total variances. This model was also confirmed by the confirmatory factor analysis to validate the factor structure of the NAS-T. The Cronbach's alpha values of three NAS-T subscales ranged from 0.89 to 0.95. Moderate to strong correlations among teachers' NAS-T domain scores, self-perception of own nanoscience knowledge, and their science-teaching efficacy demonstrated good convergent validity of the NAS-T. As a whole, psychometric properties of the NAS-T indicated that this instrument is an effective instrument for assessing K-12 teachers' attitudes toward nanotechnology. The NAS-T will serve as a valuable tool to evaluate teachers' attitude changes after participating in the K-12 Nanotechnology Programme.

  19. Environmental, health, and safety issues of sodium-sulfur batteries for electric and hybrid vehicles. Volume 1, Cell and battery safety

    SciTech Connect

    Ohi, J M

    1992-09-01

    This report is the first of four volumes that identify and assess the environmental, health, and safety issues involved in using sodium-sulfur (Na/S) battery technology as the energy source in electric and hybrid vehicles that may affect the commercialization of Na/S batteries. This and the other reports on recycling, shipping, and vehicle safety are intended to help the Electric and Hybrid Propulsion Division of the Office of Transportation Technologies in the US Department of Energy (DOE/EHP) determine the direction of its research, development, and demonstration (RD&D) program for Na/S battery technology. The reports review the status of Na/S battery RD&D and identify potential hazards and risks that may require additional research or that may affect the design and use of Na/S batteries. This volume covers cell design and engineering as the basis of safety for Na/S batteries and describes and assesses the potential chemical, electrical, and thermal hazards and risks of Na/S cells and batteries as well as the RD&D performed, under way, or to address these hazards and risks. The report is based on a review of the literature and on discussions with experts at DOE, national laboratories and agencies, universities, and private industry. Subsequent volumes will address environmental, health, and safety issues involved in shipping cells and batteries, using batteries to propel electric vehicles, and recycling and disposing of spent batteries. The remainder of this volume is divided into two major sections on safety at the cell and battery levels. The section on Na/S cells describes major component and potential failure modes, design, life testing and failure testing, thermal cycling, and the safety status of Na/S cells. The section on batteries describes battery design, testing, and safety status. Additional EH&S information on Na/S batteries is provided in the appendices.

  20. Environmental, health, and safety issues of sodium-sulfur batteries for electric and hybrid vehicles

    SciTech Connect

    Ohi, J.M.

    1992-09-01

    This report is the first of four volumes that identify and assess the environmental, health, and safety issues involved in using sodium-sulfur (Na/S) battery technology as the energy source in electric and hybrid vehicles that may affect the commercialization of Na/S batteries. This and the other reports on recycling, shipping, and vehicle safety are intended to help the Electric and Hybrid Propulsion Division of the Office of Transportation Technologies in the US Department of Energy (DOE/EHP) determine the direction of its research, development, and demonstration (RD D) program for Na/S battery technology. The reports review the status of Na/S battery RD D and identify potential hazards and risks that may require additional research or that may affect the design and use of Na/S batteries. This volume covers cell design and engineering as the basis of safety for Na/S batteries and describes and assesses the potential chemical, electrical, and thermal hazards and risks of Na/S cells and batteries as well as the RD D performed, under way, or to address these hazards and risks. The report is based on a review of the literature and on discussions with experts at DOE, national laboratories and agencies, universities, and private industry. Subsequent volumes will address environmental, health, and safety issues involved in shipping cells and batteries, using batteries to propel electric vehicles, and recycling and disposing of spent batteries. The remainder of this volume is divided into two major sections on safety at the cell and battery levels. The section on Na/S cells describes major component and potential failure modes, design, life testing and failure testing, thermal cycling, and the safety status of Na/S cells. The section on batteries describes battery design, testing, and safety status. Additional EH S information on Na/S batteries is provided in the appendices.

  1. Comparison of UV/hydrogen peroxide, potassium ferrate(VI), and ozone in oxidizing the organic fraction of oil sands process-affected water (OSPW).

    PubMed

    Wang, Chengjin; Klamerth, Nikolaus; Messele, Selamawit Ashagre; Singh, Arvinder; Belosevic, Miodrag; Gamal El-Din, Mohamed

    2016-09-01

    The efficiency of three different oxidation processes, UV/H2O2 oxidation, ferrate(VI) oxidation, and ozonation with and without hydroxyl radical (OH) scavenger tert-butyl alcohol (TBA) on the removal of organic compounds from oil sands process-affected water (OSPW) was investigated and compared. The removal of aromatics and naphthenic acids (NAs) was explored by synchronous fluorescence spectra (SFS), ion mobility spectra (IMS), proton and carbon nuclear magnetic resonance ((1)H and (13)C NMR), and ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC TOF-MS). UV/H2O2 oxidation occurred through radical reaction and photolysis, transforming one-ring, two-ring, and three-ring fluorescing aromatics simultaneously and achieving 42.4% of classical NAs removal at 2.0 mM H2O2 and 950 mJ/cm(2) UV dose provided with medium pressure mercury lamp. Ferrate(VI) oxidation exhibited high selectivity, preferentially removing two-ring and three-ring fluorescing aromatics, sulfur-containing NAs (NAs + S), and NAs with high carbon and high hydrogen deficiency. At 2.0 mM Fe(VI), 46.7% of classical NAs was removed. Ozonation achieved almost complete removal of fluorescing aromatics, NAs + S, and classical NAs (NAs with two oxygen atoms) at the dose of 2.0 mM O3. Both molecular ozone reaction and OH reaction were important pathways in transforming the organics in OSPW as supported by ozonation performance with and without TBA. (1)H NMR analyses further confirmed the removal of aromatics and NAs both qualitatively and quantitatively. All the three oxidation processes reduced the acute toxicity towards Vibrio fischeri and on goldfish primary kidney macrophages (PKMs), with ozonation being the most efficient. PMID:27232992

  2. Neonatal Outcomes and their Relationship to Maternal Buprenorphine Dose during Pregnancy

    PubMed Central

    Jones, Hendrée E.; Dengler, Erin; Garrison, Anna; O'Grady, Kevin E.; Seashore, Carl; Horton, Evette; Andringa, Kim; Jansson, Lauren M.; Thorp, John

    2014-01-01

    Background Buprenorphine pharmacotherapy for opioid-dependent pregnant women is associated with maternal and neonatal outcomes superior to untreated opioid dependence. However, the literature is inconsistent regarding the possible existence of a dose-response relationship between maternal buprenorphine dose and neonatal clinical outcomes. Methods The present secondary analysis study (1) examined the relationship between maternal buprenorphine dose at delivery and neonatal abstinence syndrome (NAS) peak score, estimated gestational age at delivery, Apgar scores at 1 and 5 minutes, neonatal head circumference, length, and weight at birth, amount of morphine needed to treat NAS, duration of NAS treatment, and duration of neonatal hospital stay; and (2) compared neonates who required pharmacotherapy for NAS to neonates who did not require such pharmacotherapy on these same outcomes, in 58 opioid-dependent pregnant women receiving buprenorphine as participants in a randomized clinical trial. Results (1) Analyses failed to provide evidence of a relationship between maternal buprenorphine dose at delivery and any of the 10 outcomes (all p-values>.48); and (2) significant mean differences between the untreated (n=31) and treated (n=27) for NAS groups were found for duration of neonatal hospital stay and NAS peak score (both p-values<.001). Conclusions (1) Findings failed to support the existence of a dose-response relationship between maternal buprenorphine dose at delivery and any of 10 neonatal clinical outcomes, including NAS severity; and (2) that infants treated for NAS had a higher mean NAS peak score and, spent a longer time in the hospital than did the group not treated for NAS is unsurprising. PMID:24290979

  3. Diversity and abundance of nitrate assimilation genes in the northern South china sea.

    PubMed

    Cai, Haiyuan; Jiao, Nianzhi

    2008-11-01

    Marine heterotrophic microorganisms that assimilate nitrate play an important role in nitrogen and carbon cycling in the water column. The nasA gene, encoding the nitrate assimilation enzyme, was selected as a functional marker to examine the nitrate assimilation community in the South China Sea (SCS). PCR amplification, restriction fragment length polymorphism (RFLP) screening, and phylogenetic analysis of nasA gene sequences were performed to characterize in situ nitrate assimilatory bacteria. Furthermore, the effects of nutrients and other environmental factors on the genetic heterogeneity of nasA fragments from the SCS were evaluated at the surface in three stations, and at two other depths in one of these stations. The diversity indices and rarefaction curves indicated that the nasA gene was more diverse in offshore waters than in the Pearl River estuary. The phylotype rank abundance curve showed an abundant and unique RFLP pattern in all five libraries, indicating that a high diversity but low abundance of nasA existed in the study areas. Phylogenetic analysis of environmental nasA gene sequences further revealed that the nasA gene fragments came from several common aquatic microbial groups, including the Proteobacteria, Cytophaga-Flavobacteria (CF), and Cyanobacteria. In addition to the direct PCR/sequence analysis of environmental samples, we also cultured a number of nitrate assimilatory bacteria isolated from the field. Comparison of nasA genes from these isolates and from the field samples indicated the existence of horizontal nasA gene transfer. Application of real-time quantitative PCR to these nasA genes revealed a great variation in their abundance at different investigation sites and water depths.

  4. [Measuring Instruments of the Quality of Life Pediatric Palliative Care].

    PubMed

    Araújo, Joana; Dourado, Marília; Ferreira, Pedro Lopes

    2015-01-01

    Introdução: Os cuidados paliativos estão intimamente ligados ao conceito de qualidade de vida. Neste trabalho, focaremos a nossa atenção na necessidade de avaliar a qualidade de vida em cuidados paliativos pediátricos oncológicos.Objetivo: Descrever/comparar os instrumentos de medição da qualidade de vida em cuidados paliativos pediátricos oncológicos. Material e Métodos: Pesquisa da bibliográfica dos vários instrumentos de medição da qualidade de vida das crianças em cuidados paliativos, em inglês e português, entre 2000 e 2013, nas bases de dados reconhecidas para este efeito. Resultados: Encontraram-se quinze instrumentos de medição: 10 genéricos e cinco específicos. Identificou-se, para cada instrumento de medição, país de origem, faixa etária para que se encontra direcionado, modalidade de preenchimento, número de dimensões avaliadas, descrição das dimensões, número de perguntas, propriedades psicométricas e validação para português. Discussão: Verifica-se que tem havido uma crescente preocupação em medir a qualidade de vida em idade pediátrica e que a maioria dos instrumentos de medição foi desenhada, nos Estados Unidos, após 1994, coincidindo temporalmente com a definição de qualidade de vida da Organização Mundial de Saúde. Relativamente à faixa etária, a maioria dos instrumentos foi desenvolvida para crianças com idade igual ou superior a oito anos não existindo nenhum para ser respondido apenas pela criança. Podemos verificar que a maioria dos instrumentos de medição, sobretudo os mais atuais, procuram envolver a criança na avaliação da sua própria qualidadede vida relacionada com a saúde através do autopreenchimento (n = 10). Porém, há ainda uma dependência substancial dos pais para a medição da qualidade de vida relacionada com a saúde dos seus filhos, apesar dos estudos que demonstram diferenças na perceção de qualidade de vida relacionada com a saúde entre a criança e os pais

  5. Naphthenic acids in coastal sediments after the Hebei Spirit oil spill: a potential indicator for oil contamination.

    PubMed

    Wan, Yi; Wang, Beili; Khim, Jong Seong; Hong, Seongjin; Shim, Won Joon; Hu, Jianying

    2014-04-01

    Naphthenic acids (NAs) as toxic components in most petroleum sources are suspected to be one of the major pollutants in the aquatic environment following oil spills, and the polarity and persistence of NAs make it a potential indicator for oil contamination. However, the contamination and potential effects of pollutants in oil spill affected areas remain unknown. To investigate NAs in oil spill affected areas, a sensitive method was first established for analysis of NAs, together with oxy-NAs in sediment samples by UPLC-QTOF-MS. Then the method was applied to determine the NA mixtures in crude oil, weathered oil, and sediments from the spilled sites after the Hebei Spirit oil spill, Taean, South Korea (Dec. 2007). Concentrations of NAs, O3-NAs, and O4-NAs were found to be 7.8-130, 3.6-44, and 0.8-20 mg kg(-1) dw in sediments from the Taean area, respectively, which were much greater than those measured in the reference sites of Manlipo and Anmyundo beaches. Concentrations of NAs were 50-100 times greater than those (0.077-2.5 mg kg(-1) dw) of PAHs in the same sediment samples, thus the ecological risk of NAs in oil spill affected areas deserves more attention. The sedimentary profiles of oil-derived NAs and background NAs centered around compounds with 21-35 and 12-21 carbons, respectively, indicating that the crude-derived NA mixtures originating from the 2007 oil spill were persistent. Acyclic NAsn=5-20 were easily degraded compared to cyclic NAsn=21-41 during the oil weathering processes, and the ratio of oxy-NAsn=21-41 relative to NAsn=21-41 could be a novel index to estimate the degree of oil weathering in sediments. Altogether, the persistent oil-derived NAsn=21-41 could be used as a potential indicator for oil-specific contamination, as such compounds would not be much affected by the properties of coastal sediments possibly due to the high sorption of the negatively charged compounds (NAs) in sediment.

  6. Application of patterned growth of aligned zinc oxide nanoarrays by mirocontact printing in quantum dots-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Deng, Jianping; Wang, Minqiang; Yang, Zhi; Liu, Jing; Sun, Zhongwang; Song, Xiaohui

    2015-04-01

    This paper describes a simple method for patterned growth of ZnO nanoarrays (NAs) that is based on a combination of the microcontact printing process for patterning ZnO seed films and the low-temperature hydrothermal approach for depositing ZnO NAs. The patterned ZnO seed films were achieved via printing patterned TiO2 sol on ZnO seed films. It is found that the pattern quality is mainly affected by the viscosity of TiO2 ink and the pressure including value and direction. To assess the possibility of patterned ZnO NAs applied to devices, the patterned ZnO NAs were used as light scattering layer in CdSe-sensitized solar cells. The diffuse-reflection, absorption and transmission spectra show that the patterned ZnO NAs greatly enhance the light scattering and absorbance in the visible range. The enhancement of cell performance is attributed to the patterned ZnO NAs: 1) multiple-light scattering improves the light absorbance, and 2) NAs with high electron mobility facilitate the electron collection.

  7. Internal-Modified Dithiol DNA–Directed Au Nanoassemblies: Geometrically Controlled Self–Assembly and Quantitative Surface–Enhanced Raman Scattering Properties

    PubMed Central

    Yan, Yuan; Shan, Hangyong; Li, Min; Chen, Shu; Liu, Jianyu; Cheng, Yanfang; Ye, Cui; Yang, Zhilin; Lai, Xuandi; Hu, Jianqiang

    2015-01-01

    In this work, a hierarchical DNA–directed self–assembly strategy to construct structure–controlled Au nanoassemblies (NAs) has been demonstrated by conjugating Au nanoparticles (NPs) with internal–modified dithiol single-strand DNA (ssDNA) (Au–B–A or A–B–Au–B–A). It is found that the dithiol–ssDNA–modified Au NPs and molecule quantity of thiol–modified ssDNA grafted to Au NPs play critical roles in the assembly of geometrically controlled Au NAs. Through matching Au–DNA self–assembly units, geometrical structures of the Au NAs can be tailored from one–dimensional (1D) to quasi–2D and 2D. Au–B–A conjugates readily give 1D and quasi–2D Au NAs while 2D Au NAs can be formed by A–B–Au–B–A building blocks. Surface-enhanced Raman scattering (SERS) measurements and 3D finite–difference time domain (3D-FDTD) calculation results indicate that the geometrically controllable Au NAs have regular and linearly “hot spots”–number–depended SERS properties. For a certain number of NPs, the number of “hot spots” and accordingly enhancement factor of Au NAs can be quantitatively evaluated, which open a new avenue for quantitative analysis based on SERS technique. PMID:26581251

  8. [In Process Citation].

    PubMed

    Reyna, Nadia; Moreno-Rojas, Rafael; Mendoza, Laura; Parra, Karla; Linares, Sergia; Reyna, Eduardo; Cámara-Martos, Fernando

    2016-02-16

    Se estudió el consumo de tres tipos de suplementos, proteínas del lactosuero, caseínas y maltodextrinas (control) en la disminución de la ingesta energética y prolongación del efecto de saciedad de 60 mujeres obesas. Después de 10 semanas, la reducción del peso corporal, IMC, % de grasa corporal y circunferencia de la cintura fue significativamente mayor (p < 0,001) en el grupo que consumió las proteínas lactoséricas frente a los otros dos grupos (control y caseínas). También se observa un descenso en la ingesta energética de -383 kcal/día en las mujeres que consumieron las proteínas de lactosuero frente a un descenso de -144 kcal/día en el grupo de caseínas y de tan solo -70 kcal/día en el grupo control. Finalmente la regulación del efecto de saciedad mediante escala visual analógica fue también más efectiva en el caso de las proteínasséricas, que en el caso de las caseínas y maltodextrinas.

  9. Enhanced accumulation of secreted human growth hormone by transgenic tobacco cells correlates with the introduction of an N-glycosylation site.

    PubMed

    Xu, Jianfeng; Kieliszewski, Marcia

    2011-06-10

    Extracellular secretion of recombinant proteins from plant cell suspension culture will simplify the protein purification procedure and greatly reduce the production cost. Our early work indicated that presence of hydroxyproline-O-glycosylation at the C- or N-terminus of the target protein boosted the secreted yields in the culture medium. Inspired by early successes, we tested the possibility of introducing an N-glycosylation site to facilitate the secretion of human growth hormone (hGH) from cultured tobacco cells. Three N-glycosylated hGH fusion proteins, designated NAS-EK-hGH, NAS-Kex2-hGH and hGH-NAS, were expressed in tobacco BY-2 cells. Where NAS denotes the "Asn-Ala-Ser" consensus sequence for N-glycosylation; EK denotes an enterokinase cleavage site and Kex2 a sequence to be cleaved by a Golgi-localized Kex2p-like protease. Our results indicated that a single N-glycan attached either at the N-terminus or C-terminus of hGH correlated with enhanced extracellular accumulation of the transgenic proteins; the secreted yield of NAS-EK-hGH and hGH-NAS was 70-90 fold greater than the control targeted, non-glycosylated hGH. NAS-Kex2-hGH was subject to partial cleavage of the N-glycan tag at the Kex2 site in Golgi apparatus, and therefore gave lower yields than the other two constructs.

  10. Microwave treatment of naphthenic acids in water.

    PubMed

    Mishra, Sabyasachi; Meda, Venkatesh; Dalai, Ajay K; Headley, John V; Peru, Kerry M; McMartin, Dena W

    2010-08-01

    Naphthenic acids (NAs) are natural constituents of bitumen and crude oil. These compounds are concentrated as part of the oil sands process water (OSPW) during petroleum refining and separation from oil sands. NAs are considered among the major water contaminants in OSPW due to their toxicity and environmental recalcitrance. A laboratory scale microwave system was developed and experiments were conducted to determine the efficiency of NA degradation during microwave treatment. The effects of water source and quality (deionized lab water and river water) and of TiO(2) catalyst in the degradation process were also investigated. Degradation kinetic parameters for both total NAs and individual z-family were calculated. The microwave system degraded OSPW NAs and commercial Fluka NAs in river water in the presence of TiO(2) rapidly, producing half-life values of 3.32 and 3.61 hours, respectively. Toxicity assessments of the NA samples pre-and post-treatment indicated that the microwave system reduced overall toxicity of water containing Fluka NAs from high (5 min. IC(50) v/v = 15.85%) to moderate (5 min. IC(50) v/v = 36.45%) toxicity levels. However, a slight increase in toxicity was noted post-treatment in OSPW NAs.

  11. [In Process Citation].

    PubMed

    Reyna, Nadia; Moreno-Rojas, Rafael; Mendoza, Laura; Parra, Karla; Linares, Sergia; Reyna, Eduardo; Cámara-Martos, Fernando

    2016-01-01

    Se estudió el consumo de tres tipos de suplementos, proteínas del lactosuero, caseínas y maltodextrinas (control) en la disminución de la ingesta energética y prolongación del efecto de saciedad de 60 mujeres obesas. Después de 10 semanas, la reducción del peso corporal, IMC, % de grasa corporal y circunferencia de la cintura fue significativamente mayor (p < 0,001) en el grupo que consumió las proteínas lactoséricas frente a los otros dos grupos (control y caseínas). También se observa un descenso en la ingesta energética de -383 kcal/día en las mujeres que consumieron las proteínas de lactosuero frente a un descenso de -144 kcal/día en el grupo de caseínas y de tan solo -70 kcal/día en el grupo control. Finalmente la regulación del efecto de saciedad mediante escala visual analógica fue también más efectiva en el caso de las proteínasséricas, que en el caso de las caseínas y maltodextrinas. PMID:27019242

  12. Internal-Modified Dithiol DNA-Directed Au Nanoassemblies: Geometrically Controlled Self-Assembly and Quantitative Surface-Enhanced Raman Scattering Properties

    NASA Astrophysics Data System (ADS)

    Yan, Yuan; Shan, Hangyong; Li, Min; Chen, Shu; Liu, Jianyu; Cheng, Yanfang; Ye, Cui; Yang, Zhilin; Lai, Xuandi; Hu, Jianqiang

    2015-11-01

    In this work, a hierarchical DNA-directed self-assembly strategy to construct structure-controlled Au nanoassemblies (NAs) has been demonstrated by conjugating Au nanoparticles (NPs) with internal-modified dithiol single-strand DNA (ssDNA) (Au-B-A or A-B-Au-B-A). It is found that the dithiol-ssDNA-modified Au NPs and molecule quantity of thiol-modified ssDNA grafted to Au NPs play critical roles in the assembly of geometrically controlled Au NAs. Through matching Au-DNA self-assembly units, geometrical structures of the Au NAs can be tailored from one-dimensional (1D) to quasi-2D and 2D. Au-B-A conjugates readily give 1D and quasi-2D Au NAs while 2D Au NAs can be formed by A-B-Au-B-A building blocks. Surface-enhanced Raman scattering (SERS) measurements and 3D finite-difference time domain (3D-FDTD) calculation results indicate that the geometrically controllable Au NAs have regular and linearly “hot spots”-number-depended SERS properties. For a certain number of NPs, the number of “hot spots” and accordingly enhancement factor of Au NAs can be quantitatively evaluated, which open a new avenue for quantitative analysis based on SERS technique.

  13. Commercial naphthenic acids and the organic fraction of oil sands process water induce different effects on pro-inflammatory gene expression and macrophage phagocytosis in mice.

    PubMed

    Garcia-Garcia, Erick; Pun, Jonathan; Hodgkinson, Jordan; Perez-Estrada, Leonidas A; El-Din, Mohamed Gamal; Smith, Daniel W; Martin, Jonathan W; Belosevic, Miodrag

    2012-12-01

    Naphthenic acids (NAs) are believed to be the major toxic component of oil sands process water (OSPW). Different OSPW preparations have distinct NA compositions, and additional organics, that differ from the commercial NAs (C-NAs) often used for toxicology studies. To evaluate whether C-NAs are an adequate model to study OSPW toxicity in complex organisms, we compared the effects of C-NAs and the extractable organic fraction of OSPW (OSPW-OF) on mice immune mechanisms. Mice were orally exposed to different C-NA doses, or OSPW-OF at the same NA dose, for up to 8 weeks, and the expression of pro-inflammatory genes in different organs was determined using quantitative PCR. C-NAs and OSPW-OF altered the expression of pro-inflammatory genes, inducing either expression down-regulation or up-regulation, depending on the organ examined and time after exposure. The time at which gene expression alterations occurred, and the specific sets of genes whose expression was altered, were very different between animals exposed to C-NAs or to OSPW-OF. We evaluated the ability of mouse peritoneal macrophages to phagocytose yeast cell wall, as a measure of the ability of mice to mount a central function of the innate immune response. Phagocytosis was significantly reduced in animals exposed to C-NAs, but enhanced in mice exposed to OSPW-OF. Our results indicate that studies using C-NAs may not necessarily reflect the possible effects induced in animals by process water from tailing ponds.

  14. The NYC native air sampling pilot project: using HVAC filter data for urban biological incident characterization.

    PubMed

    Ackelsberg, Joel; Leykam, Frederic M; Hazi, Yair; Madsen, Larry C; West, Todd H; Faltesek, Anthony; Henderson, Gavin D; Henderson, Christopher L; Leighton, Terrance

    2011-09-01

    Native air sampling (NAS) is distinguished from dedicated air sampling (DAS) devices (eg, BioWatch) that are deployed to detect aerosol disseminations of biological threat agents. NAS uses filter samples from heating, ventilation, and air conditioning (HVAC) systems in commercial properties for environmental sampling after DAS detection of biological threat agent incidents. It represents an untapped, scientifically sound, efficient, widely distributed, and comparably inexpensive resource for postevent environmental sampling. Calculations predict that postevent NAS would be more efficient than environmental surface sampling by orders of magnitude. HVAC filter samples could be collected from pre-identified surrounding NAS facilities to corroborate the DAS alarm and delineate the path taken by the bioaerosol plume. The New York City (NYC) Native Air Sampling Pilot Project explored whether native air sampling would be acceptable to private sector stakeholders and could be implemented successfully in NYC. Building trade associations facilitated outreach to and discussions with property owners and managers, who expedited contact with building managers of candidate NAS properties that they managed or owned. Nominal NAS building requirements were determined; procedures to identify and evaluate candidate NAS facilities were developed; data collection tools and other resources were designed and used to expedite candidate NAS building selection and evaluation in Manhattan; and exemplar environmental sampling playbooks for emergency responders were completed. In this sample, modern buildings with single or few corporate tenants were the best NAS candidate facilities. The Pilot Project successfully demonstrated that in one urban setting a native air sampling strategy could be implemented with effective public-private collaboration. PMID:21793731

  15. The NYC native air sampling pilot project: using HVAC filter data for urban biological incident characterization.

    PubMed

    Ackelsberg, Joel; Leykam, Frederic M; Hazi, Yair; Madsen, Larry C; West, Todd H; Faltesek, Anthony; Henderson, Gavin D; Henderson, Christopher L; Leighton, Terrance

    2011-09-01

    Native air sampling (NAS) is distinguished from dedicated air sampling (DAS) devices (eg, BioWatch) that are deployed to detect aerosol disseminations of biological threat agents. NAS uses filter samples from heating, ventilation, and air conditioning (HVAC) systems in commercial properties for environmental sampling after DAS detection of biological threat agent incidents. It represents an untapped, scientifically sound, efficient, widely distributed, and comparably inexpensive resource for postevent environmental sampling. Calculations predict that postevent NAS would be more efficient than environmental surface sampling by orders of magnitude. HVAC filter samples could be collected from pre-identified surrounding NAS facilities to corroborate the DAS alarm and delineate the path taken by the bioaerosol plume. The New York City (NYC) Native Air Sampling Pilot Project explored whether native air sampling would be acceptable to private sector stakeholders and could be implemented successfully in NYC. Building trade associations facilitated outreach to and discussions with property owners and managers, who expedited contact with building managers of candidate NAS properties that they managed or owned. Nominal NAS building requirements were determined; procedures to identify and evaluate candidate NAS facilities were developed; data collection tools and other resources were designed and used to expedite candidate NAS building selection and evaluation in Manhattan; and exemplar environmental sampling playbooks for emergency responders were completed. In this sample, modern buildings with single or few corporate tenants were the best NAS candidate facilities. The Pilot Project successfully demonstrated that in one urban setting a native air sampling strategy could be implemented with effective public-private collaboration.

  16. Environmental, health, and safety issues of sodium-sulfur batteries for electric and hybrid vehicles. Volume 2, Battery recycling and disposal

    SciTech Connect

    Corbus, D

    1992-09-01

    Recycling and disposal of spent sodium-sulfur (Na/S) batteries are important issues that must be addressed as part of the commercialization process of Na/S battery-powered electric vehicles. The use of Na/S batteries in electric vehicles will result in significant environmental benefits, and the disposal of spent batteries should not detract from those benefits. In the United States, waste disposal is regulated under the Resource Conservation and Recovery Act (RCRA). Understanding these regulations will help in selecting recycling and disposal processes for Na/S batteries that are environmentally acceptable and cost effective. Treatment processes for spent Na/S battery wastes are in the beginning stages of development, so a final evaluation of the impact of RCRA regulations on these treatment processes is not possible. The objectives of tills report on battery recycling and disposal are as follows: Provide an overview of RCRA regulations and requirements as they apply to Na/S battery recycling and disposal so that battery developers can understand what is required of them to comply with these regulations; Analyze existing RCRA regulations for recycling and disposal and anticipated trends in these regulations and perform a preliminary regulatory analysis for potential battery disposal and recycling processes. This report assumes that long-term Na/S battery disposal processes will be capable of handling large quantities of spent batteries. The term disposal includes treatment processes that may incorporate recycling of battery constituents. The environmental regulations analyzed in this report are limited to US regulations. This report gives an overview of RCRA and discusses RCRA regulations governing Na/S battery disposal and a preliminary regulatory analysis for Na/S battery disposal.

  17. An integrated biochemical system for nitrate assimilation and nitric oxide detoxification in Bradyrhizobium japonicum

    PubMed Central

    Cabrera, Juan J.; Salas, Ana; Torres, María J.; Bedmar, Eulogio J.; Richardson, David J.; Gates, Andrew J.; Delgado, María J.

    2015-01-01

    Rhizobia are recognized to establish N2-fixing symbiotic interactions with legume plants. Bradyrhizobium japonicum, the symbiont of soybeans, can denitrify and grow under free-living conditions with nitrate (NO3−) or nitrite (NO2−) as sole nitrogen source. Unlike related bacteria that assimilate NO3−, genes encoding the assimilatory NO3− reductase (nasC) and NO2− reductase (nirA) in B. japonicum are located at distinct chromosomal loci. The nasC gene is located with genes encoding an ABC-type NO3− transporter, a major facilitator family NO3−/NO2− transporter (NarK), flavoprotein (Flp) and single-domain haemoglobin (termed Bjgb). However, nirA clusters with genes for a NO3−/NO2−-responsive regulator (NasS-NasT). In the present study, we demonstrate NasC and NirA are both key for NO3− assimilation and that growth with NO3−, but not NO2− requires flp, implying Flp may function as electron donor to NasC. In addition, bjgb and flp encode a nitric oxide (NO) detoxification system that functions to mitigate cytotoxic NO formed as a by-product of NO3− assimilation. Additional experiments reveal NasT is required for NO3−-responsive expression of the narK-bjgb-flp-nasC transcriptional unit and the nirA gene and that NasS is also involved in the regulatory control of this novel bipartite assimilatory NO3−/NO2− reductase pathway. PMID:26564204

  18. Evanescent Wave-Assisted Symmetry Breaking of Gold Dipolar Nanoantennas.

    PubMed

    Yang, Jhen-Hong; Chen, Kuo-Ping

    2016-01-01

    Symmetry-breaking and scattering cancellation were observed in the dark-mode resonance of dipolar gold nanoantennas (NAs) on glass substrates coupled with oblique incidence and total internal reflection. With the assistance of evanescent waves, the coupling efficiency was twice as strong when the incidence angle was larger than the critical angle. The Hamiltonian equation and absorption spectra were used to analyze the hybridization model of symmetric dipolar gold NAs. The antibonding mode could be coupled successfully by both transverse-magnetic (TM) and transverse-electric (TE) polarizations to NAs when the dimers orientation is parallel to the propagation direction of evanescent waves.

  19. Evanescent Wave-Assisted Symmetry Breaking of Gold Dipolar Nanoantennas

    PubMed Central

    Yang, Jhen-Hong; Chen, Kuo-Ping

    2016-01-01

    Symmetry-breaking and scattering cancellation were observed in the dark-mode resonance of dipolar gold nanoantennas (NAs) on glass substrates coupled with oblique incidence and total internal reflection. With the assistance of evanescent waves, the coupling efficiency was twice as strong when the incidence angle was larger than the critical angle. The Hamiltonian equation and absorption spectra were used to analyze the hybridization model of symmetric dipolar gold NAs. The antibonding mode could be coupled successfully by both transverse-magnetic (TM) and transverse-electric (TE) polarizations to NAs when the dimers orientation is parallel to the propagation direction of evanescent waves. PMID:27581766

  20. Evanescent Wave-Assisted Symmetry Breaking of Gold Dipolar Nanoantennas.

    PubMed

    Yang, Jhen-Hong; Chen, Kuo-Ping

    2016-01-01

    Symmetry-breaking and scattering cancellation were observed in the dark-mode resonance of dipolar gold nanoantennas (NAs) on glass substrates coupled with oblique incidence and total internal reflection. With the assistance of evanescent waves, the coupling efficiency was twice as strong when the incidence angle was larger than the critical angle. The Hamiltonian equation and absorption spectra were used to analyze the hybridization model of symmetric dipolar gold NAs. The antibonding mode could be coupled successfully by both transverse-magnetic (TM) and transverse-electric (TE) polarizations to NAs when the dimers orientation is parallel to the propagation direction of evanescent waves. PMID:27581766

  1. Alternative Architectures for Distributed Work in the National Airspace System

    NASA Technical Reports Server (NTRS)

    Smith, Philip J.; Billings, Charles E.; Chapman, Roger; Obradovich, Heintz; McCoy, C. Elaine; Orasanu, Judith

    2000-01-01

    The architecture for the National Airspace System (NAS) in the United States has evolved over time to rely heavily on the distribution of tasks and control authority in order to keep cognitive complexity manageable for any one individual. This paper characterizes a number of different subsystems that have been recently incorporated in the NAS. The goal of this discussion is to begin to identify the critical parameters defining the differences among alternative architectures in terms of the locus of control and in terms of access to relevant data and knowledge. At an abstract level, this analysis can be described as an effort to describe alternative "rules of the game" for the NAS.

  2. Evanescent Wave-Assisted Symmetry Breaking of Gold Dipolar Nanoantennas

    NASA Astrophysics Data System (ADS)

    Yang, Jhen-Hong; Chen, Kuo-Ping

    2016-09-01

    Symmetry-breaking and scattering cancellation were observed in the dark-mode resonance of dipolar gold nanoantennas (NAs) on glass substrates coupled with oblique incidence and total internal reflection. With the assistance of evanescent waves, the coupling efficiency was twice as strong when the incidence angle was larger than the critical angle. The Hamiltonian equation and absorption spectra were used to analyze the hybridization model of symmetric dipolar gold NAs. The antibonding mode could be coupled successfully by both transverse-magnetic (TM) and transverse-electric (TE) polarizations to NAs when the dimers orientation is parallel to the propagation direction of evanescent waves.

  3. 78 FR 20686 - Federal Property Suitable as Facilities To Assist the Homeless

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-05

    ... accessibility/removal reqs. New York Housing Units 424 USS North Carolina Rd. Staten Island NY 10305 Landholding... for accessibility/removal reqs. Unsuitable Properties Building Florida Building 798 NAS...

  4. ONTOGENY OF PROTEINS FOR USE AS BIOMARKERS OF DEVELOPMENTAL NEUROTOXICITY.

    EPA Science Inventory

    The developing nervous system can be uniquely susceptible to adverse effects following exposure to environmental chemicals, and several advisory panels (e.g. ILSI, NRC, NAS) have highlighted the need for rapid and sensitive developmental neurotoxicity testing methods. Measurement...

  5. 77 FR 18791 - Proposed Information Collection; Comment Request; NIST Associates Information System

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-28

    ... National Institute of Standards and Technology Proposed Information Collection; Comment Request; NIST Associates Information System AGENCY: National Institute of Standards and Technology (NIST). ACTION: Notice... Associates Information System (NAIS) information collection instrument(s) are completed by incoming NAs....

  6. National Academy of Sciences

    MedlinePlus

    ... Read More » Proceedings of the National Academy of Sciences (PNAS) PNAS is one of the world’s most- ... Exchange Evolution Resources Biographical Memoirs National Academy of Sciences About The NAS Mission History Organization Leadership and ...

  7. Non-caloric artificial sweeteners and the microbiome: findings and challenges.

    PubMed

    Suez, Jotham; Korem, Tal; Zilberman-Schapira, Gili; Segal, Eran; Elinav, Eran

    2015-01-01

    Non-caloric artificial sweeteners (NAS) are common food supplements consumed by millions worldwide as means of combating weight gain and diabetes, by retaining sweet taste without increasing caloric intake. While they are considered safe, there is increasing controversy regarding their potential ability to promote metabolic derangements in some humans. We recently demonstrated that NAS consumption could induce glucose intolerance in mice and distinct human subsets, by functionally altering the gut microbiome. In this commentary, we discuss these findings in the context of previous and recent works demonstrating the effects of NAS on host health and the microbiome, and the challenges and open questions that need to be addressed in understanding the effects of NAS consumption on human health. PMID:25831243

  8. Shuttle Replica On The Way To Space Center Houston

    NASA Video Gallery

    Atop a barge, the space shuttle full-scale replica nears the completion of its eight-day journey from the Kennedy Space Center destined for permanent retention at Space Center Houston, near the NAS...

  9. Saturn and Enceladus Electrical Link

    NASA Video Gallery

    This animated graphic shows how Saturn and its moon Enceladus are electrically linked. Magnetic field lines, invisible to the human eye but detectable by the fields and particles instruments on NAS...

  10. 21 CFR 310.6 - Applicability of “new drug” or safety or effectiveness findings in drug efficacy study...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... National Academy of Sciences-National Research Council (NAS-NRC), Drug Efficacy Study Group. Many products... drug moiety related in chemical structure or known pharmacological properties. (2) Where...

  11. 21 CFR 310.6 - Applicability of “new drug” or safety or effectiveness findings in drug efficacy study...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... National Academy of Sciences-National Research Council (NAS-NRC), Drug Efficacy Study Group. Many products... drug moiety related in chemical structure or known pharmacological properties. (2) Where...

  12. Application of the Web-based Interspecies Correlation Estimation (Web-ICE) tool to assess risks of national pesticide registrations to federally listed (threatened and endangered) species

    EPA Science Inventory

    The National Academy of Science (NAS) recently recommended exploration of predictive tools, such as interspecies correlation estimation (ICE), to estimate acute toxicity values for listed species and support development of species sensitivity distributions (SSDs). We explored the...

  13. 78 FR 69653 - Cancellation of the Notice of Intent To Prepare an Environmental Impact Statement for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-20

    ... 9, 2008 (73 FR 19196), the DoN announced its intent to prepare an EIS to evaluate the potential... aircraft squadrons stationed at and transient to Naval Air Station (NAS) Oceana and Naval Station...

  14. Space-X Launches Falcon 9 on Demonstration Flight

    NASA Video Gallery

    SpaceX's Falcon 9 rocket and Dragon spacecraft launched from Launch Complex 40 at Cape Canaveral Air Force Station at 10:43 a.m. EST on Wednesday, Dec. 8. This is first demonstration flight for NAS...

  15. Development of remedial process options: Phase II, Feasibility study: Installation Restoration Program, Naval Air Station Fallon, Fallon, Nevada

    SciTech Connect

    Cronk, T.A.; Smuin, D.R.; Schlosser, R.M.

    1991-11-01

    This technical memorandum develops process options which are appropriate for environmental restoration activities at Naval Air Station Fallon (NAS Fallon), Nevada. Introduction of contaminants to the environment has resulted from deliberate disposal activities (both through dumping and landfilling) and accidental spills and leaks associated with normal activities at NAS Fallon over its lifetime of operation. Environmental sampling results indicate that the vast majority of contaminants of concern are petroleum hydrocarbon related. These contaminants include JP-4, JP-5, leaded and unleaded gasoline, waste oils and lubricants, hydraulic fluids, and numerous solvents and cleaners. The principal exposure pathways of concern associated with NAS Fallon contaminants appear to be the surface flows and shallow drainage systems to which the base contributes. Available data indicate NAS Fallon IR Program sites are not contributing excessive contamination to surface flows emanating from the base. Contaminants appear to be contained in a relatively immobile state in the shallow subsurface with little or no contaminant migration off site.

  16. Microinjections of a nicotinic agonist into dopamine terminal fields: effects on locomotion.

    PubMed

    Museo, E; Wise, R A

    1990-09-01

    Nicotine induces locomotion, a behavior associated with the mesocorticolimbic dopamine system. The present study determined the effects on locomotion of direct microinjections of the nicotinic agonist cytisine into four DA terminal fields were nicotinic receptors have been localized: nucleus accumbens (NAS, n = 20), caudate putamen (CPU, n = 9), olfactory tubercle (OT, n = 8), and medial prefrontal cortex (MPC, n = 12). Male Long-Evans rats were injected with cytisine (0.1, 1, 10 and 100 nanomoles per 0.5 microliters per side) or vehicle through indwelling cannulae, and locomotor activity was recorded during a 60-minute test session; each animal was tested with each dose in counterbalanced order. NAS injections of the three highest doses of cytisine increased locomotion relative to vehicle injections; injections in the CPU, dorsal to the NAS, were ineffective, as were MPC and OT injections. The data support the notion that systemic nicotine may interact with dopaminergic projections to the NAS to produce increases in locomotor activity.

  17. Oral Cancer Foundation

    MedlinePlus

    ... Oral Cancer Foundation is a national public service, non-profit entity designed to reduce suffering and save lives ... National Academy of Sciences (NAS) is a private, non-profit society of distinguished scholars. Established by an Act ...

  18. 21 CFR 201.100 - Prescription drugs for human use.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... which it is possible to determine the complete manufacturing history of the package of the drug. (7) A... labeling claims for the drug by the National Academy of Sciences/National Research Council (NAS/NRC),...

  19. 21 CFR 201.100 - Prescription drugs for human use.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... which it is possible to determine the complete manufacturing history of the package of the drug. (7) A... labeling claims for the drug by the National Academy of Sciences/National Research Council (NAS/NRC),...

  20. Neonatal Abstinence Syndrome: Essentials for the Practitioner

    PubMed Central

    Robinson, Christine A.

    2014-01-01

    The incidence of neonatal abstinence syndrome (NAS) has increased dramatically during the past 15 years, likely due to an increase in antepartum maternal opiate use. Optimal care of these patients is still controversial because of the available published literature lacking sufficient sample size, placebo control, and comparative pharmacologic trials. Primary treatment for NAS consists of opioid replacement therapy with either morphine or methadone. Paregoric and tincture of opium have been abandoned because of relative safety concerns. Buprenorphine is emerging as a treatment option with promising initial experience. Adjunctive agents should be considered for infants failing treatment with opioid monotherapy. Traditionally, phenobarbital has been used as adjunctive therapy; however, results of clonidine as adjunctive therapy for NAS appear to be beneficial. Future directions for research in NAS should include validating a simplified scoring tool, conducting comparative studies, exploring home management options, and optimizing management through pharmacogenomics. PMID:25309144

  1. Non-caloric artificial sweeteners and the microbiome: findings and challenges

    PubMed Central

    Suez, Jotham; Korem, Tal; Zilberman-Schapira, Gili; Segal, Eran; Elinav, Eran

    2015-01-01

    Non-caloric artificial sweeteners (NAS) are common food supplements consumed by millions worldwide as means of combating weight gain and diabetes, by retaining sweet taste without increasing caloric intake. While they are considered safe, there is increasing controversy regarding their potential ability to promote metabolic derangements in some humans. We recently demonstrated that NAS consumption could induce glucose intolerance in mice and distinct human subsets, by functionally altering the gut microbiome. In this commentary, we discuss these findings in the context of previous and recent works demonstrating the effects of NAS on host health and the microbiome, and the challenges and open questions that need to be addressed in understanding the effects of NAS consumption on human health. PMID:25831243

  2. ADVISORY ON UPDATED METHODOLOGY FOR ESTIMATING CANCER RISKS FROM EXPOSURE TO IONIZING RADIATION

    EPA Science Inventory

    The National Academy of Sciences (NAS) published the Biological Effects of Ionizing Radiation (BEIR) committee's report (BEIR VII) on risks from ionizing radiation exposures in 2006. The Committee analyzed the most recent epidemiology from the important exposed cohorts and factor...

  3. 21 CFR 201.100 - Prescription drugs for human use.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., optionally, information relating to quantitative ingredient statements, dosage form, quantity of package... labeling claims for the drug by the National Academy of Sciences/National Research Council (NAS/NRC),...

  4. 21 CFR 201.100 - Prescription drugs for human use.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., optionally, information relating to quantitative ingredient statements, dosage form, quantity of package... labeling claims for the drug by the National Academy of Sciences/National Research Council (NAS/NRC),...

  5. Sodium-sulfur battery flight experiment definition study

    NASA Technical Reports Server (NTRS)

    Chang, Rebecca; Minck, Robert

    1990-01-01

    Sodium-sulfur batteries are considered to be one of the most likely battery systems for space applications. Compared with the Ni-H2 or Ni-Co battery systems, Na-S batteries offer a mass reduction by a factor of 2 to 4, representing significant launch cost savings or increased payload mass capabilities. The Na-S battery operates at between 300 and 400 C, using liquid sodium and sulfur/polysulfide electrodes and solid ceramic electrolyte; the transport of the electrode materials to the surface of the electrolyte is through wicking/capillary forces. This paper describes five tests identified for the Na-S battery flight experiment definition study, which include the cell characterization test, the reactant distribution test, the current/temperature distribution test, the freeze/thaw test, and the multicell LEO test. A schematic diagram of Na-S cell is included.

  6. JWST Secondary Mirror Deploy Timelapse

    NASA Video Gallery

    Setting up NASA's James Webb Space Telescope's secondary mirror in space will require special arms that resemble a tripod that was recently demonstrated in a NASA cleanroom. TRT: 1:25 / Credit: NAS...

  7. 21 CFR 520.784 - Doxylamine succinate tablets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... some signs of disease in horses, dogs, and cats. 1 1 These conditions are NAS/NRC reviewed and deemed... weight per day divided into 3 or 4 equal doses. It is administered orally to dogs and cats at a...

  8. 21 CFR 520.784 - Doxylamine succinate tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... some signs of disease in horses, dogs, and cats. 1 1 These conditions are NAS/NRC reviewed and deemed... weight per day divided into 3 or 4 equal doses. It is administered orally to dogs and cats at a...

  9. 21 CFR 520.784 - Doxylamine succinate tablets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... some signs of disease in horses, dogs, and cats. 1 1 These conditions are NAS/NRC reviewed and deemed... weight per day divided into 3 or 4 equal doses. It is administered orally to dogs and cats at a...

  10. Neonatal abstinence syndrome: essentials for the practitioner.

    PubMed

    Siu, Anita; Robinson, Christine A

    2014-07-01

    The incidence of neonatal abstinence syndrome (NAS) has increased dramatically during the past 15 years, likely due to an increase in antepartum maternal opiate use. Optimal care of these patients is still controversial because of the available published literature lacking sufficient sample size, placebo control, and comparative pharmacologic trials. Primary treatment for NAS consists of opioid replacement therapy with either morphine or methadone. Paregoric and tincture of opium have been abandoned because of relative safety concerns. Buprenorphine is emerging as a treatment option with promising initial experience. Adjunctive agents should be considered for infants failing treatment with opioid monotherapy. Traditionally, phenobarbital has been used as adjunctive therapy; however, results of clonidine as adjunctive therapy for NAS appear to be beneficial. Future directions for research in NAS should include validating a simplified scoring tool, conducting comparative studies, exploring home management options, and optimizing management through pharmacogenomics. PMID:25309144

  11. IRIS Toxicological Review of Formaldehyde (Inhalation) (External Review Draft 2010)

    EPA Science Inventory

    UPDATE EPA is currently revising its Integrated Risk Information System (IRIS) assessment of formaldehyde to address the 2011 NAS peer review recommendations. This assessment addresses both noncancer and cancer human health effects that are relevant to assessing ...

  12. A Celebration of the Space Shuttle Program

    NASA Video Gallery

    On September 23, 2011, NASA Langley hosted a Shuttle Celebration at the Virginia Air & Space Center in Hampton, Va. More than 650 guests attended, including STS-135 Commander Chris Ferguson and NAS...

  13. 75 FR 81270 - Notice of Public Information Collection(s) Being Submitted for Review and Approval to the Office...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-27

    ...: 25 respondents; 25 responses. Estimated Time per Response: 1 hour. Frequency of Response: On occasion... frequencies is compatible with the NAS, which shares system components with the military. The notification must describe the equipment, give the manufacturer's identification, antenna characteristics,...

  14. Uranium and Aluminosilicate Surface Precipitation Tests

    SciTech Connect

    Hu, M.Z.

    2002-11-27

    The 2H evaporator at the Savannah River Site has been used to treat an aluminum-rich waste stream from canyon operations and a silicon-rich waste stream from the Defense Waste Processing Facility. The formation of aluminosilicate scale in the evaporator has caused significant operational problems. Because uranium has been found to accumulate in the aluminosilicate solids, the scale deposition has introduced criticality concerns as well. The objective of the tests described in this report is to determine possible causes of the uranium incorporation in the evaporator scale materials. The scope of this task is to perform laboratory experiments with simulant solutions to determine if (1) uranium can be deposited on the surfaces of various sodium aluminosilicate (NAS) forms and (2) aluminosilicates can form on the surfaces of uranium-containing solids. Batch experiments with simulant solutions of three types were conducted: (1) contact of uranium solutions/sols with NAS coatings on stainless steel surfaces, (2) contact of uranium solutions with NAS particles, and (3) contact of precipitated uranium-containing particles with solutions containing aluminum and silicon. The results show that uranium can be incorporated in NAS solids through encapsulation in bulk agglomerated NAS particles of different phases (amorphous, zeolite A, sodalite, and cancrinite) as well as through heterogeneous deposition on the surfaces of NAS coatings (amorphous and cancrinite) grown on stainless steel. The results also indicate that NAS particles can grow on the surfaces of precipitated uranium solids. Particularly notable for evaporator operations is the finding that uranium solids can form on existing NAS scale, including cancrinite solids. If NAS scale is present, and uranium is in sufficient concentration in solution to precipitate, a portion of the uranium can be expected to become associated with the scale. The data obtained to date on uranium-NAS affinity are qualitative. A necessary

  15. Cell cycle effect on the activity of deoxynucleoside analogue metabolising enzymes

    SciTech Connect

    Fyrberg, Anna; Albertioni, Freidoun; Lotfi, Kourosh . E-mail: koulo@imv.liu.se

    2007-06-15

    Deoxynucleoside analogues (dNAs) are cytotoxic towards both replicating and indolent malignancies. The impact of fluctuations in the metabolism of dNAs in relation to cell cycle could have strong implications regarding the activity of dNAs. Deoxycytidine kinase (dCK) and deoxyguanosine kinase (dGK) are important enzymes for phosphorylation/activation of dNAs. These drugs can be dephosphorylated/deactivated by 5'-nucleotidases (5'-NTs) and elevated activities of 5'-NTs and decreased dCK and/or dGK activities represent resistance mechanisms towards dNAs. The activities of dCK, dGK, and three 5'-NTs were investigated in four human leukemic cell lines in relationship to cell cycle progression and cytotoxicity of dNAs. Synchronization of cell cultures to arrest in G0/G1 by serum-deprivation was performed followed by serum-supplementation for cell cycle progression. The activities of dCK and dGK increased up to 3-fold in CEM, HL60, and MOLT-4 cells as they started to proliferate, while the activity of cytosolic nucleotidase I was reduced in proliferating cells. CEM, HL60, and MOLT-4 cells were also more sensitive to cladribine, cytarabine, 9-{beta}-D-arabinofuranosylguanine and clofarabine than K562 cells which demonstrated lower levels and less alteration of these enzymes and were least susceptible to the cytotoxic effects of most dNAs. The results suggest that, in the cell lines studied, the proliferation process is associated with a general shift in the direction of activation of dNAs by inducing activities of dCK/dGK and reducing the activity of cN-I which is favourable for the cytotoxic effects of cladribine, cytarabine and, 9-{beta}-D-arabinofuranosylguanine. These results emphasize the importance of cellular proliferation and dNA metabolism by both phosphorylation and dephosphorylation for susceptibility to dNAs. It underscores the need to understand the mechanisms of action and resistance to dNAs in order to increase efficacy of dNAs treatment by new rational.

  16. Value of Magnetic Resonance Cholangiopancreatography in Assessment of Nonanastomotic Biliary Strictures After Liver Transplantation

    PubMed Central

    den Dulk, A. Claire; Wasser, Martin N.J.M.; Willemssen, François E.J.A.; Monraats, Melanie A.; de Vries, Marianne; van den Boom, Rivka; Ringers, Jan; Verspaget, Hein W.; Metselaar, Herold J.; van Hoek, Bart

    2015-01-01

    Background Nonanastomotic biliary strictures (NAS) remain a frequent complication after orthotopic liver transplantation (OLT). The aim of this study was to evaluate whether magnetic resonance cholangiopancreatography (MRCP) could be used to detect NAS and to grade the severity of biliary strictures. Methods In total, 58 patients after OLT from 2 Dutch transplantation centers in whom endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangiography and MRCP were performed within less than 6 months apart were included in the study. Of these patients, 41 had NAS and 17 were without NAS based on endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangiography and follow-up. Four radiologists—2 from each center—used an adapted validated classification—termed “Leiden Biliary Stricture Classification” “(LBSC)—to evaluate the MRCP examinations independently. In this classification, NAS severity is assessed in 4 hepatobiliary regions. Interobserver agreement of the severity score for each region was calculated with the κ statistics. Results Optimal cutoff value of the LBSC to detect the presence of NAS with MRCP was calculated at 3 points or greater for all readers. Applying this cutoff sensitivity for each reader was greater than 90%, with a specificity of 50% to 82%, positive predictive value of 86% to 91%, and negative predictive value of 80% to 100%. The MRCP performance was better in evaluation of the intrahepatic than of the extrahepatic bile ducts. The additional value of MRCP for grading severity of NAS was limited. Conclusions The MRCP with the LBSC is a reliable tool to detect or exclude NAS after OLT. Currently, MRCP cannot be used to reliably grade the severity of these strictures. PMID:27500210

  17. A high-energy room-temperature sodium-sulfur battery.

    PubMed

    Xin, Sen; Yin, Ya-Xia; Guo, Yu-Guo; Wan, Li-Jun

    2014-02-26

    Employing small sulfur molecules as the active cathode component for room-temperature Na-S batteries, reveals a novel mechanism that is verified for the batteries' electrochemistry. The sulfur cathode enables a complete two-electron reaction to form Na2 S, bringing a tripled specific capacity and an increased specific energy compared with traditional high-temperature Na-S batteries. At the same time, it offers better cycling stability endowing the batteries with a longer lifespan.

  18. A survey of parallel programming tools

    NASA Technical Reports Server (NTRS)

    Cheng, Doreen Y.

    1991-01-01

    This survey examines 39 parallel programming tools. Focus is placed on those tool capabilites needed for parallel scientific programming rather than for general computer science. The tools are classified with current and future needs of Numerical Aerodynamic Simulator (NAS) in mind: existing and anticipated NAS supercomputers and workstations; operating systems; programming languages; and applications. They are divided into four categories: suggested acquisitions, tools already brought in; tools worth tracking; and tools eliminated from further consideration at this time.

  19. Investigation of Advanced Counterrotation Blade Configuration Concepts for High Speed Turboprop Systems. Task 8: Cooling Flow/heat Transfer Analysis User's Manual

    NASA Technical Reports Server (NTRS)

    Hall, Edward J.; Topp, David A.; Heidegger, Nathan J.; Delaney, Robert A.

    1994-01-01

    The focus of this task was to validate the ADPAC code for heat transfer calculations. To accomplish this goal, the ADPAC code was modified to allow for a Cartesian coordinate system capability and to add boundary conditions to handle spanwise periodicity and transpiration boundaries. This user's manual describes how to use the ADPAC code as developed in Task 5, NAS3-25270, including the modifications made to date in Tasks 7 and 8, NAS3-25270.

  20. CTAS and NASA Air Traffic Management Fact Sheets for En Route Descent Advisor and Surface Management System

    NASA Technical Reports Server (NTRS)

    Lee, Katharine

    2004-01-01

    The Surface Management System (SMS) is a decision support tool that will help controllers, traffic managers, and NAS users manage the movements of aircraft on the surface of busy airports, improving capacity, efficiency, and flexibility. The Advanced Air Transportation Technologies (AATT) Project at NASA is developing SMS in cooperation with the FAA's Free Flight Phase 2 (FFP2) pro5ram. SMS consists of three parts: a traffic management tool, a controller tool, and a National Airspace System (NAS) information tool.

  1. Fate and effect of naphthenic acids on oil refinery activated sludge wastewater treatment systems.

    PubMed

    Misiti, Teresa; Tezel, Ulas; Pavlostathis, Spyros G

    2013-01-01

    Naphthenic acids (NAs) are a complex group of alkyl-substituted acyclic, monocyclic and polycyclic carboxylic acids present in oil sands process waters, crude oil, refinery wastewater and petroleum products. Crude oil, desalter brine, influent, activated sludge mixed liquor and effluent refinery samples were received from six United States refineries. The total acid number (TAN) of the six crudes tested ranged from 0.12 to 1.5 mg KOH/g crude oil and correlated to the total NA concentration in the crudes. The total NA concentration in the desalter brine, influent, activated sludge mixed liquor and effluent samples ranged from 4.2 to 40.4, 4.5 to 16.6, 9.6 to 140.3 and 2.8 to 11.6 mg NA/L, respectively. The NAs in all wastewater streams accounted for less than 16% of the total COD, indicating that many other organic compounds are present and that NAs are a minor component in refinery wastewaters. Susceptibility tests showed that none of the activated sludge heterotrophic microcosms was completely inhibited by NAs up to 400 mg/L. Growth inhibition ranging from 10 to 59% was observed in all microcosms at and above 100 mg NA/L. NAs chronically-sorbed to activated sludge mixed liquor biomass and powdered activated carbon (PAC) were recalcitrant and persistent. More than 80% of the total NAs remained in the solid phase at the end of the 10-day desorption period (five successive desorption steps). Throughout a 90-day incubation period, the total NA concentration decreased by 33 and 51% in PAC-free and PAC-containing mixed liquor microcosms, respectively. The lower molecular weight fraction of NAs was preferentially degraded in both mixed liquors. The persistence of the residual, higher molecular weight NAs is likely a combination of molecular recalcitrance and decreased bioavailability when chronically-sorbed to the biomass and/or PAC. PMID:23141768

  2. Fate and effect of naphthenic acids on oil refinery activated sludge wastewater treatment systems.

    PubMed

    Misiti, Teresa; Tezel, Ulas; Pavlostathis, Spyros G

    2013-01-01

    Naphthenic acids (NAs) are a complex group of alkyl-substituted acyclic, monocyclic and polycyclic carboxylic acids present in oil sands process waters, crude oil, refinery wastewater and petroleum products. Crude oil, desalter brine, influent, activated sludge mixed liquor and effluent refinery samples were received from six United States refineries. The total acid number (TAN) of the six crudes tested ranged from 0.12 to 1.5 mg KOH/g crude oil and correlated to the total NA concentration in the crudes. The total NA concentration in the desalter brine, influent, activated sludge mixed liquor and effluent samples ranged from 4.2 to 40.4, 4.5 to 16.6, 9.6 to 140.3 and 2.8 to 11.6 mg NA/L, respectively. The NAs in all wastewater streams accounted for less than 16% of the total COD, indicating that many other organic compounds are present and that NAs are a minor component in refinery wastewaters. Susceptibility tests showed that none of the activated sludge heterotrophic microcosms was completely inhibited by NAs up to 400 mg/L. Growth inhibition ranging from 10 to 59% was observed in all microcosms at and above 100 mg NA/L. NAs chronically-sorbed to activated sludge mixed liquor biomass and powdered activated carbon (PAC) were recalcitrant and persistent. More than 80% of the total NAs remained in the solid phase at the end of the 10-day desorption period (five successive desorption steps). Throughout a 90-day incubation period, the total NA concentration decreased by 33 and 51% in PAC-free and PAC-containing mixed liquor microcosms, respectively. The lower molecular weight fraction of NAs was preferentially degraded in both mixed liquors. The persistence of the residual, higher molecular weight NAs is likely a combination of molecular recalcitrance and decreased bioavailability when chronically-sorbed to the biomass and/or PAC.

  3. Evaluation of the Incorporation of Uranium into Sodium Aluminosilicate Phases

    SciTech Connect

    Oji, L.N.

    2003-03-26

    This report describes batch laboratory experiments performed to determine the relative amounts of uranium incorporated in aluminosilicate structures during synthesis. The findings summarized here are based on laboratory experiments, which involved the synthesis of sodium aluminosilicates (NAS) structures, amorphous, zeolites A and sodalite phases in the presence of depleted uranium and the analytical search for incorporated uranium in NAS internal structures after synthesis. These studies will support the basis for continued operation of evaporators at the Savannah River Site (SRS).

  4. Infant and maternal characteristics in neonatal abstinence syndrome--selected hospitals in Florida, 2010-2011.

    PubMed

    Lind, Jennifer N; Petersen, Emily E; Lederer, Philip A; Phillips-Bell, Ghasi S; Perrine, Cria G; Li, Ruowei; Hudak, Mark; Correia, Jane A; Creanga, Andreea A; Sappenfield, William M; Curran, John; Blackmore, Carina; Watkins, Sharon M; Anjohrin, Suzanne

    2015-03-01

    Neonatal abstinence syndrome (NAS) is a constellation of physiologic and neurobehavioral signs exhibited by newborns exposed to addictive prescription or illicit drugs taken by a mother during pregnancy. The number of hospital discharges of newborns diagnosed with NAS has increased more than 10-fold (from 0.4 to 4.4 discharges per 1,000 live births) in Florida since 1995, far exceeding the three-fold increase observed nationally. In February 2014, the Florida Department of Health requested the assistance of CDC to 1) assess the accuracy and validity of using Florida's hospital inpatient discharge data, linked to birth and infant death certificates, as a means of NAS surveillance and 2) describe the characteristics of infants with NAS and their mothers. This report focuses only on objective two, describing maternal and infant characteristics in the 242 confirmed NAS cases identified in three Florida hospitals during a 2-year period (2010-2011). Infants with NAS experienced serious medical complications, with 97.1% being admitted to an intensive care unit, and had prolonged hospital stays, with a mean duration of 26.1 days. The findings of this investigation underscore the important public health problem of NAS and add to current knowledge on the characteristics of these mothers and infants. Effective June 2014, NAS is now a mandatory reportable condition in Florida. Interventions are also needed to 1) increase the number and use of community resources available to drug-abusing and drug-dependent women of reproductive age, 2) improve drug addiction counseling and rehabilitation referral and documentation policies, and 3) link women to these resources before or earlier in pregnancy. PMID:25742381

  5. Characterization of stormwater runoff from the Naval Air Station and Naval Wepons Industrial Reserve Plant, Dallas, Texas, 1994-96

    USGS Publications Warehouse

    Raines, T.H.; Baldys, Stanley; Lizarraga, J.S.

    1997-01-01

    Median event-mean concentrations computed for 12 selected constituents in samples from NAS and NWIRP fixed sites were compared to median event-mean concentrations for residential, commercial, industrial, and highway land uses within the Dallas-Fort Worth area computed from data collected for the National Pollutant Discharge Elimination System program. NAS and NWIRP median event-mean concentrations also were compared to those for residential and commercial land uses from the Nationwide Urban Runoff Program.

  6. A Simple, Semiselective Medium for Anaerobic Isolation of Anginosus Group Streptococci from Patients with Chronic Lung Disease

    PubMed Central

    Waite, Richard D.; Wareham, David W.; Gardiner, Samuel

    2012-01-01

    The anaerobic isolation of anginosus group streptococci (AGS) from respiratory specimens containing diverse microbiota using a semiselective blood agar medium incorporating nalidixic acid and sulfamethazine (NAS) is described. AGS were detected in 60% of tested sputa from patients with cystic fibrosis, chronic obstructive pulmonary disease, and bronchiectasis. This demonstrates NAS to be a diagnostic tool for detecting AGS within the complex microbial communities associated with chronic lung disorders. PMID:22238446

  7. USGS Nonindigenous Aquatic Species database with a focus on the introduced fishes of the lower Tennessee and Cumberland drainages

    USGS Publications Warehouse

    Fuller, Pam L.; Cannister, Matthew; Johansen, Rebecca; Estes, L. Dwayne; Hamilton, Steven W.; Barrass, Andrew N.

    2013-01-01

    The Nonindigenous Aquatic Species (NAS) database (http://nas.er.usgs.gov) functions as a national repository and clearinghouse for occurrence data for introduced species within the United States. Included is locality information on over 1,100 species of vertebrates, invertebrates, and vascular plants introduced as early as 1850. Taxa include foreign (exotic) species and species native to North America that have been transported outside of their natural range. Locality data are obtained from published and unpublished literature, state, federal and local monitoring programs, museum accessions, on-line databases, websites, professional communications and on-line reporting forms. The NAS web site provides immediate access to new occurrence records through a real-time interface with the NAS database. Visitors to the web site are presented with a set of pre-defined queries that generate lists of species according to state or hydrologic basin of interest. Fact sheets, distribution maps, and information on new occurrences are updated as new records and information become available. The NAS database allows resource managers to learn of new introductions reported in their region or nearby regions, improving response time. Conversely, managers are encouraged to report their observations of new occurrences to the NAS database so information can be disseminated to other managers, researchers, and the public. In May 2004, the NAS database incorporated an Alert System to notify registered users of new introductions as part of a national early detection/rapid response system. Users can register to receive alerts based on geographic or taxonomic criteria. The NAS database was used to identify 23 fish species introduced into the lower Tennessee and Cumberland drainages. Most of these are sport fish stocked to support fisheries, but the list also includes accidental and illegal introductions such as Asian Carps, clupeids, various species popular in the aquarium trade, and Atlantic

  8. Introducing surface-modified ordered mesoporous carbon as a promising sorbent for extraction of N-nitrosamines.

    PubMed

    Lashgari, Maryam; Lee, Hian Kee

    2016-11-01

    The extraction and pre-concentration of N-nitrosamines (NAs) before their determination are mainly achieved by carbonaceous sorbents. However, the non-polar or relatively less polar NAs are strongly absorbed on the carbonaceous surface of the sorbent, leading to low extraction recoveries. In the present study, for the first time, CMK-3 and surfacemodified CMK-3 (O-CMK-3) were used to extract NAs from water. The CMK-3 surface was modified by oxidative treatment and different carboxylic groups were attached to create a hydrophilic/hydrophobic balance on the inert surface of the carbonaceous sorbent. The proposed sorbents were compared with 10 different kinds of commercial carbonaceous sorbents for the micro-solid phase extraction of eight NAs possessing a wide range of polarities. The best extraction results for both polar and non-polar NAs were obtained using O-CMK-3. Specifically, significant enhancements in the extraction of the nonpolar NAs were observed. For instance, extraction of up to 27.67 and 2.32 times greater were observed for N-nitrosodiphenylamine, and N-nitrosodimethylamine respectively, when O-CMK-3 was used instead of coconut charcoal sorbent.

  9. Indices of serum tonicity in clinical practice.

    PubMed

    Rohrscheib, Mark; Rondon-Berrios, Helbert; Argyropoulos, Christos; Glew, Robert H; Murata, Glen H; Tzamaloukas, Antonios H

    2015-06-01

    Although disturbances of serum tonicity (effective osmolality) may have dire consequences, only surrogate indices of tonicity are available in practice. This report identifies the appropriate index for expressing clinical states of dystonicity. Serum sodium concentration ([Na]S) and osmolality ([Osm]S) may be incongruent. When the tonicity state shown by [Osm]S is higher than [Na]S and the difference between the 2 indices is caused by an excess of solute that distributes in total body water, tonicity is described by [Na]S. When this difference results from a gain of solute with extracellular distribution like mannitol or a decrease in serum water content, causing a falsely low measurement of [Na]S, [Osm]S accurately reflects tonicity. Two indices of tonicity are applicable during hyperglycemia: the tonicity formula (2 ·[Na]S + [Glucose]S/18) and the corrected [Na]S ([Na]S corrected to a normal [Glucose]S using an empirically derived coefficient). Clinicians should understand the uses and limitations of the tonicity indices. PMID:26002851

  10. Making Each Other’s Daily Life: Nurse Assistants’ Experiences and Knowledge on Developing a Meaningful Daily Life in Nursing Homes

    PubMed Central

    James, Inger; Fredriksson, Carin; Wahlström, Catrin; Kihlgren, Annica; Blomberg, Karin

    2014-01-01

    Background: In a larger action research project, guidelines were generated for how a meaningful daily life could be developed for older persons. In this study, we focused on the nurse assistants’ (NAs) perspectives, as their knowledge is essential for a well-functioning team and quality of care. The aim was to learn from NAs’ experiences and knowledge about how to develop a meaningful daily life for older persons in nursing homes and the meaning NAs ascribe to their work. Methods: The project is based on Participatory and Appreciative Action and Reflection. Data were generated through interviews, participating observations and informal conversations with 27 NAs working in nursing homes in Sweden, and a thematic analysis was used. Result: NAs developed a meaningful daily life by sensing and finding the “right” way of being (Theme 1). They sense and read the older person in order to judge how the person was feeling (Theme 2). They adapt to the older person (Theme 3) and share their daily life (Theme 4). NAs use emotional involvement to develop a meaningful daily life for the older person and meaning in their own work (Theme 5), ultimately making each other’s daily lives meaningful. Conclusion: It was obvious that NAs based the development of a meaningful daily life on different forms of knowledge: the oreticaland practical knowledge, and practical wisdom, all of which are intertwined. These results could be used within the team to constitute a meaningful daily life for older persons in nursing homes. PMID:25246997

  11. Neutrophils influx and proinflammatory cytokines inhibition by sodium salicylate, unlike aspirin, in Candida albicans-induced peritonitis model.

    PubMed

    Pereira, Priscilla Aparecida Tártari; Bini, Daniel; Bovo, Fernanda; Faccioli, Lucia Helena; Monteiro, Marta Chagas

    2016-07-01

    Sodium salicylate (NaS) and aspirin (ASA) are known to have a variety of effects on microorganisms, such as fungus (C. albicans and C. neoformans), moreover, it have effects in leukocyte adhesion and migration in vitro. In this report, we investigated the effect of ASA and NaS in neutrophil migration and cytokine production in C. albicans-induced peritonitis murine model. For this, mice were treated intraperitoneally (i.p) or orally (po) with NaS or ASA; after they were stimulated i.p. with C. albicans, the cellular migration was evaluated 24 h after stimulation. NaS, in mice treated i.p., unlike ASA, was able to inhibit the neutrophil migration and proinflammatory cytokine production induced by C. albicans, such as TNF-α, IL-1, IFN-γ, IL-12, and IL-10, but did not alter the IL-4 levels in these animals. However, the po treatment with same the dose of NaS or ASA did not affect the influx of this cell for inflammatory site. These results suggest that the NaS inhibits cellular migration and proinflammatory cytokine by different anti-inflammatory mechanism compared to ASA.

  12. Impact of polymeric membrane filtration of oil sands process water on organic compounds quantification.

    PubMed

    Moustafa, Ahmed M A; Kim, Eun-Sik; Alpatova, Alla; Sun, Nian; Smith, Scott; Kang, Seoktae; Gamal El-Din, Mohamed

    2014-01-01

    The interaction between organic fractions in oil sands process-affected water (OSPW) and three polymeric membranes with varying hydrophilicity (nylon, polyvinylidene fluoride and polytetrafluoroethylene) at different pHs was studied to evaluate the impact of filtration on the quantification of acid-extractable fraction (AEF) and naphthenic acids (NAs). Four functional groups predominated in OSPW (amine, phosphoryl, carboxyl and hydroxyl) as indicated by the linear programming method. The nylon membranes were the most hydrophilic and exhibited the lowest AEF removal at pH of 8.7. However, the adsorption of AEF on the membranes increased as the pH of OSPW decreased due to hydrophobic interactions between the membrane surfaces and the protonated molecules. The use of ultra pressure liquid chromatography-high resolution mass spectrometry (UPLC/HRMS) showed insignificant adsorption of NAs on the tested membranes at pH 8.7. However, 26±2.4% adsorption of NAs was observed at pH 5.3 following the protonation of NAs species. For the nylon membrane, excessive carboxylic acids in the commercial NAs caused the formation of negatively charged assisted hydrogen bonds, resulting in increased adsorption at pH 8.2 (25%) as compared to OSPW (0%). The use of membranes for filtration of soluble compounds from complex oily wastewaters before quantification analysis of AEF and NAs should be examined prior to application.

  13. Introducing surface-modified ordered mesoporous carbon as a promising sorbent for extraction of N-nitrosamines.

    PubMed

    Lashgari, Maryam; Lee, Hian Kee

    2016-11-01

    The extraction and pre-concentration of N-nitrosamines (NAs) before their determination are mainly achieved by carbonaceous sorbents. However, the non-polar or relatively less polar NAs are strongly absorbed on the carbonaceous surface of the sorbent, leading to low extraction recoveries. In the present study, for the first time, CMK-3 and surfacemodified CMK-3 (O-CMK-3) were used to extract NAs from water. The CMK-3 surface was modified by oxidative treatment and different carboxylic groups were attached to create a hydrophilic/hydrophobic balance on the inert surface of the carbonaceous sorbent. The proposed sorbents were compared with 10 different kinds of commercial carbonaceous sorbents for the micro-solid phase extraction of eight NAs possessing a wide range of polarities. The best extraction results for both polar and non-polar NAs were obtained using O-CMK-3. Specifically, significant enhancements in the extraction of the nonpolar NAs were observed. For instance, extraction of up to 27.67 and 2.32 times greater were observed for N-nitrosodiphenylamine, and N-nitrosodimethylamine respectively, when O-CMK-3 was used instead of coconut charcoal sorbent. PMID:27451033

  14. Necklace-shaped Au-Ag nanoalloys: laser-assisted synthesis and nonlinear optical properties

    NASA Astrophysics Data System (ADS)

    Jafarkhani, P.; Torkamany, M. J.; Dadras, S.; Chehrghani, A.; Sabbaghzadeh, J.

    2011-06-01

    Here in this paper, necklace-shaped Au-Ag nanoalloys (NAs) have been synthesized by a laser-based approach. A chain of Ag nanoparticles (NPs), which were joined together with Au junctions, was formed upon copper vapor laser (CVL) irradiation of a colloidal mixture of Ag and Au NPs; while the corresponding NPs were separately provided by laser ablation of gold and silver targets in deionized water by a 1064 nm Q-switched Nd:YAG laser. Dependence of the NAs development process on the CVL irradiation time in three distinct stages of as-mixed, nucleation and complete formation has been systematically studied by UV-vis optical absorption spectroscopy analysis as well as by transmission electron microscopy (TEM), which was exploited to visually confirm the NAs evolution through the process. Furthermore, the x-ray photoelectron spectroscopy (XPS) technique was accurately employed to determine the synthesized alloy content. On the other hand, using the open-and closed-aperture Z-scan technique, the nonlinear absorption (NLA) as well as nonlinear refraction (NLR) changes in Au-Ag NAs were investigated through their formation. The deduced results from the nonlinear optical properties of the colloidal NAs in the mentioned stages were interpreted considering the spectroscopic and microscopic observations. The total change of individual Au and Ag NPs saturable absorption (SA) into the reverse saturable absorption (RSA) behavior was concluded through the evolution into Au-Ag NAs.

  15. High Altitude Long Endurance Remotely Operated Aircraft - National Airspace System Integration - Simulation IPT: Detailed Airspace Operations Simulation Plan. Version 1.0

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The primary goal of Access 5 is to allow safe, reliable and routine operations of High Altitude-Long Endurance Remotely Operated Aircraft (HALE ROAs) within the National Airspace System (NAS). Step 1 of Access 5 addresses the policies, procedures, technologies and implementation issues of introducing such operations into the NAS above pressure altitude 40,000 ft (Flight Level 400 or FL400). Routine HALE ROA activity within the NAS represents a potentially significant change to the tasks and concerns of NAS users, service providers and other stakeholders. Due to the complexity of the NAS, and the importance of maintaining current high levels of safety in the NAS, any significant changes must be thoroughly evaluated prior to implementation. The Access 5 community has been tasked with performing this detailed evaluation of routine HALE-ROA activities in the NAS, and providing to key NAS stakeholders a set of recommended policies and procedures to achieve this goal. Extensive simulation, in concert with a directed flight demonstration program are intended to provide the required supporting evidence that these recommendations are based on sound methods and offer a clear roadmap to achieving safe, reliable and routine HALE ROA operations in the NAS. Through coordination with NAS service providers and policy makers, and with significant input from HALE-ROA manufacturers, operators and pilots, this document presents the detailed simulation plan for Step 1 of Access 5. A brief background of the Access 5 project will be presented with focus on Steps 1 and 2, concerning HALE-ROA operations above FL400 and FL180 respectively. An overview of project management structure follows with particular emphasis on the role of the Simulation IPT and its relationships to other project entities. This discussion will include a description of work packages assigned to the Simulation IPT, and present the specific goals to be achieved for each simulation work package, along with the associated

  16. Culturing oil sands microbes as mixed species communities enhances ex situ model naphthenic acid degradation.

    PubMed

    Demeter, Marc A; Lemire, Joseph A; Yue, Gordon; Ceri, Howard; Turner, Raymond J

    2015-01-01

    Oil sands surface mining for bitumen results in the formation of oil sands process water (OSPW), containing acutely toxic naphthenic acids (NAs). Potential exists for OSPW toxicity to be mitigated by aerobic degradation of the NAs by microorganisms indigenous to the oil sands tailings ponds, the success of which is dependent on the methods used to exploit the metabolisms of the environmental microbial community. Having hypothesized that the xenobiotic tolerant biofilm mode-of-life may represent a feasible way to harness environmental microbes for ex situ treatment of OSPW NAs, we aerobically grew OSPW microbes as single and mixed species biofilm and planktonic cultures under various conditions for the purpose of assaying their ability to tolerate and degrade NAs. The NAs evaluated were a diverse mixture of eight commercially available model compounds. Confocal microscopy confirmed the ability of mixed and single species OSPW cultures to grow as biofilms in the presence of the NAs evaluated. qPCR enumeration demonstrated that the addition of supplemental nutrients at concentrations of 1 g L(-1) resulted in a more numerous population than 0.001 g L(-1) supplementation by approximately 1 order of magnitude. GC-FID analysis revealed that mixed species cultures (regardless of the mode of growth) are the most effective at degrading the NAs tested. All constituent NAs evaluated were degraded below detectable limits with the exception of 1-adamantane carboxylic acid (ACA); subsequent experimentation with ACA as the sole NA also failed to exhibit degradation of this compound. Single species cultures degraded select few NA compounds. The degradation trends highlighted many structure-persistence relationships among the eight NAs tested, demonstrating the effect of side chain configuration and alkyl branching on compound recalcitrance. Of all the isolates, the Rhodococcus spp. degraded the greatest number of NA compounds, although still less than the mixed species cultures

  17. Culturing oil sands microbes as mixed species communities enhances ex situ model naphthenic acid degradation

    PubMed Central

    Demeter, Marc A.; Lemire, Joseph A.; Yue, Gordon; Ceri, Howard; Turner, Raymond J.

    2015-01-01

    Oil sands surface mining for bitumen results in the formation of oil sands process water (OSPW), containing acutely toxic naphthenic acids (NAs). Potential exists for OSPW toxicity to be mitigated by aerobic degradation of the NAs by microorganisms indigenous to the oil sands tailings ponds, the success of which is dependent on the methods used to exploit the metabolisms of the environmental microbial community. Having hypothesized that the xenobiotic tolerant biofilm mode-of-life may represent a feasible way to harness environmental microbes for ex situ treatment of OSPW NAs, we aerobically grew OSPW microbes as single and mixed species biofilm and planktonic cultures under various conditions for the purpose of assaying their ability to tolerate and degrade NAs. The NAs evaluated were a diverse mixture of eight commercially available model compounds. Confocal microscopy confirmed the ability of mixed and single species OSPW cultures to grow as biofilms in the presence of the NAs evaluated. qPCR enumeration demonstrated that the addition of supplemental nutrients at concentrations of 1 g L-1 resulted in a more numerous population than 0.001 g L-1 supplementation by approximately 1 order of magnitude. GC-FID analysis revealed that mixed species cultures (regardless of the mode of growth) are the most effective at degrading the NAs tested. All constituent NAs evaluated were degraded below detectable limits with the exception of 1-adamantane carboxylic acid (ACA); subsequent experimentation with ACA as the sole NA also failed to exhibit degradation of this compound. Single species cultures degraded select few NA compounds. The degradation trends highlighted many structure-persistence relationships among the eight NAs tested, demonstrating the effect of side chain configuration and alkyl branching on compound recalcitrance. Of all the isolates, the Rhodococcus spp. degraded the greatest number of NA compounds, although still less than the mixed species cultures

  18. N-Acetylserotonin: Circadian Activation of the BDNF Receptor and Neuroprotection in the Retina and Brain

    PubMed Central

    Iuvone, P. Michael; Boatright, Jeffrey H.; Tosini, Gianluca; Ye, Keqiang

    2014-01-01

    TrkB is the cognate receptor for brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family involved in neuronal survival, neurogenesis and synaptic plasticity. BDNF has been shown to protect photoreceptors from light-induced retinal degeneration (LIRD) and to improve ganglion cell survival following optic nerve damage. However, the utility of BDNF as a retinal neuroprotectant is limited by its short half-life, inability to cross the blood-brain and blood-retinal barriers, and activation of the proapoptotic p75 neurotrophin receptor. N-Acetylserotonin (NAS) is a naturally occurring chemical intermediate in the melatonin biosynthetic pathway in the pineal gland and retina. Its synthesis occurs in a circadian fashion with high levels at night and is suppressed by light exposure. Until recently, NAS was thought to function primarily as a melatonin precursor with little or no biological function of its own. We have now shown that TrkB activation in the retina and hippocampus is circadian in C3H/f+/+ mice, which synthesize NAS, but not in C57BL/6 mice, which have a mutation in the gene encoding the enzyme that converts serotonin to NAS. In addition, treatment of mice exogenous NAS, but not with serotonin or melatonin, activates TrkB during the daytime in a BDNF-independent manner. NAS appears to have neuroprotective properties and its administration reduces caspase 3 activation in the brain in response to kainic acid, a neurotoxic glutamate analog. We have developed structural analogs of NAS that activate TrkB. One of these derivatives, N-[2- (5-hydroxy-1H-indol-3-yl)ethyl]-2-oxopiperideine- 3-carboximide (HIOC), selectively activates TrkB with greater potency than NAS and has a significantly longer biological half-life than NAS after systemic administration. HIOC administration results in long-lasting activation of TrkB and downstream signaling kinases. The compound can pass the blood-brain and blood-retinal barriers when administered systemically

  19. Anaerobic biodegradation of surrogate naphthenic acids.

    PubMed

    Clothier, Lindsay N; Gieg, Lisa M

    2016-03-01

    Surface bitumen extraction from the Alberta's oil sands region generates large settling basins known as tailings ponds. The oil sands process-affected water (OSPW) stored in these ponds contain solid and residual bitumen-associated compounds including naphthenic acids (NAs) that can potentially be biodedgraded by indigenous tailings microorganisms. While the biodegradation of some NAs is known to occur under aerobic conditions, little is understood about anaerobic NA biodegradation even though tailings ponds are mainly anoxic. Here, we investigated the potential for anaerobic NA biodegradation by indigenous tailings microorganisms. Enrichment cultures were established from anoxic tailings that were amended with 5 single-ringed surrogate NAs or acid-extractable organics (AEO) from OSPW and incubated under nitrate-, sulfate-, iron-reducing, and methanogenic conditions. Surrogate NA depletion was observed under all anaerobic conditions tested to varying extents, correlating to losses in the respective electron acceptor (sulfate or nitrate) or the production of predicted products (Fe(II) or methane). Tailings-containing cultures incubated under the different electron-accepting conditions resulted in the enrichment and putative identification of microbial community members that may function in metabolizing surrogate NAs under the various anoxic conditions. In addition, more complex NAs (in the form of AEO) was observed to drive sulfate and iron reduction relative to controls. Overall, this study has shown that simple surrogate NAs can be biodegraded under a variety of anoxic conditions, a key first step in understanding the potential anaerobic metabolism of NAs in oil sands tailings ponds and other industrial wastewaters. PMID:26724449

  20. Photocatalytic degradation of commercially sourced naphthenic acids by TiO2-graphene composite nanomaterial.

    PubMed

    Liu, Juncheng; Wang, Lin; Tang, Jingchun; Ma, Jianli

    2016-04-01

    Naphthenic acids (NAs) are a major contributor to the toxicity in oil sands process-affected water (OSPW), which is produced by hot water extraction of bitumen. NAs are extremely difficult to be degraded due to its complex ring and side chain structure. Photocatalysis is recognized as a promising technology in the removal of refractory organic pollutants. In this work, TiO2-graphene (P25-GR) composites were synthesized by means of solvothermal method. The results showed that P25-GR composite exhibited better photocatalytic activity than pure P25. The removal efficiency of naphthenic acids in acid solution was higher than that in neutral and alkaline solutions. It was the first report ever known on the photodegradation of NAs based on graphene, and this process achieved a higher removal rate than other photocatalysis degradation of NAs in a shorter reaction time. LC/MS analysis showed that macromolecular NAs (carbon number 17-22, z value -2) were easy to be degraded than the micromolecular ones (carbon number 11-16, z value -2). Furthermore, the reactive oxygen species that play the main role in the photocatalysis system were studied. It was found that holes and ·OH were the main reactive species in the UV/P25-GR photocatalysis system. Given the high removal efficiency of refractory organic pollutants and the short degradation time, photodegradation based on composite catalysts has a broad and practical prospect. The study on the photodegradation of commercially sourced NAs may provide a guidance for the degradation of OSPW NAs by this method.

  1. [Preparation and evaluation of N-acryloyltris (hydroxymethyl) aminomethane-bonded chromatographic stationary phase].

    PubMed

    Cheng, Xiaodong; Feng, Yuqi

    2015-09-01

    The present study described the preparation of N-acryloyltris (hydroxymethyl) aminomethane-bonded silica (NAS) stationary phase based on "thiol-ene" click chemistry. The composition of the surface grafts of NAS stationary phase was determined by elemental analysis and the results demonstrated the successful introduction of the N-acryloyltris (hydroxymethyl) aminomethane groups to the silica surface. Similar elemental composition of three batches of the NAS stationary phases exhibited good reproducibility of the preparation strategy. A set of standard compounds were employed to investigate the retention mechanism of the NAS stationary phase by three different empirical equations. The results indicated the retention of the tested analytes on the NAS stationary phase was based more on a mixed-mechanism rather than a simple partitioning or adsorption process. Eight compounds were selected to study the hydrophobic and hydrophilic properties of the NAS stationary phase in mobile phase with different ACN contents. Due to its hydrophilic triolacrylamide groups and short hydrophobic alkyl chains, the NAS phase was successfully applied in both reversed-phase liquid chromatography (RPLC) mode and hydrophilic interaction liquid chromatography (HILIC) mode. The influence of flow rate on the column efficiency was compared in these two modes. In contrast to RPLC columns, the overall heights equivalent to a theoretical plate (HETP) in HILIC is weakly dependent on the retention of the analyte and the HETP curve is much flatter in RPLC than in HILIC at larger reduced velocities. Furthermore, the separation of alkylbenzenes, nucleosides and nucleobases, water-soluble vitamins was achieved on the new stationary phase, demonstrating the excellent application potential.

  2. Direct electrochemistry of glucose oxidase entrapped in nano gold particles-ionic liquid-N,N-dimethylformamide composite film on glassy carbon electrode and glucose sensing.

    PubMed

    Li, Jiangwen; Yu, Jingjing; Zhao, Faqiong; Zeng, Baizhao

    2007-03-21

    The direct electrochemistry of glucose oxidase (GOD) entrapped in nano gold particles (NAs)-N,N-dimethylformamide (DMF)-1-butyl-3-methylimidazolium hexafluophosphate (BMIMPF(6)) composite film on a glassy carbon electrode (NAs-DMF-GOD (BMIMPF(6))/GC) has been investigated for first time. The immobilized GOD exhibits a pair of well-defined reversible peaks in 0.050 M pH 5 phosphate solutions (PS), resulting from the redox of flavin adenine dinucleotide (FAD) in GOD. The peak currents are three times as large as those of GOD-NAs-DMF film coated GC electrode (i.e. NAs-DMF-GOD (water)/GC). In addition, the NAs-DMF-GOD (BMIMPF(6)) composite material has higher thermal stability than NAs-DMF-GOD (water). Results show that ionic liquid BMIMPF(6), DMF and NAs are requisite for GOD to exhibit a pair of stable and reversible peaks. Without any of them, the peaks of GOD become small and unstable. Upon the addition of glucose, the peak currents of GOD decrease and a new cathodic peak occurs at -0.8 V (versus SCE), which corresponds to the reduction of hydrogen peroxide (H(2)O(2)) generated by the catalytic oxidation of glucose. The peak current of the new cathodic peak and the glucose concentration show a linear relationship in the ranges of 1.0 x 10(-7) to 1.0 x 10(-6)M and 2.0 x 10(-6) to 2.0 x 10(-5) M. The kinetic parameter I(max) of H(2)O(2) is estimated to be 1.19 x 10(-6)A and the apparent K(m) (Michaelis-Menten constant) for the enzymatic reaction is 3.49 microM. This method has been successfully applied to the determination of glucose in human plasma and beer samples, and the average recoveries are 97.2% and 99%, respectively.

  3. Integrated Test and Evaluation Flight Test 3 Flight Test Plan

    NASA Technical Reports Server (NTRS)

    Marston, Michael Lawrence

    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

  4. Increasing Incidence and Geographic Distribution of Neonatal Abstinence Syndrome: United States 2009-2012

    PubMed Central

    Patrick, Stephen W.; Davis, Matthew M.; Lehman, Christoph U.; Cooper, William O.

    2015-01-01

    Objective Neonatal abstinence syndrome (NAS), a postnatal opioid withdrawal syndrome, increased 3-fold from 2000 to 2009. Since 2009, opioid pain reliever prescriptions and complications increased markedly throughout the US. Understanding recent changes in NAS and its geographic variability would inform state and local governments in targeting public health responses. Study Design We utilized diagnostic and demographic data for hospital discharges from 2009 to 2012 from the Kids’ Inpatient Database and the Nationwide Inpatient Sample. NAS-associated diagnoses were identified utilizing ICD-9-CM codes. All analyses were conducted with nationally weighted data. Expenditure data were adjusted to 2012 US dollars. Between-year differences were determined utilizing least squares regression. Results From 2009 to 2012, NAS incidence increased nationally from 3.4 (95%CI: 3.2-3.6) to 5.8 (95%CI 5.5-6.1) per 1,000 hospital births, reaching a total of 21,732 infants with the diagnosis. Aggregate hospital charges for NAS increased from $732M to $1.5B (p<0.001), with 81% attributed to state Medicaid programs in 2012. NAS incidence varied by geographic Census division, with the highest incidence rate (per 1000 hospital births) of 16.2 (95%CI 12.4-18.9) in the East South Central Division (KY, TN, MS, AL) and the lowest in West South Central Division 2.6 (95%CI 2.3-2.9; [OK, TX, AR, LA]). Conclusion NAS incidence and hospital charges grew substantially during our study period. This costly public health problem merits a public health approach to alleviate harm to women and children. States, particularly in areas of the country most affected by the syndrome, must continue to pursue primary prevention strategies to limit the effects of opioid pain reliever misuse. PMID:25927272

  5. Neuraminidase hemadsorption activity, conserved in avian influenza A viruses, does not influence viral replication in ducks.

    PubMed Central

    Kobasa, D; Rodgers, M E; Wells, K; Kawaoka, Y

    1997-01-01

    The N1 and N9 neuraminidase (NA) subtypes of influenza A viruses exhibit significant hemadsorption activity that localizes to a site distinct from that of the enzymatic active site. To determine the conservation of hemadsorption activity among different NAs, we have examined most of the NA subtypes from avian, swine, equine, and human virus isolates. All subtypes of avian virus NAs examined and one equine virus N8 NA possessed high levels of hemadsorption activity. A swine virus N1 NA exhibited only weak hemadsorption activity, while in human virus N1 and N2 NAs, the activity was detected at a much lower level than in avian virus NAs. NAs which possessed hemadsorption activity for chicken erythrocytes (RBCs) were similarly able to adsorb human RBCs. However, none of the hemadsorption-positive NAs could bind equine, swine, or bovine RBCs, suggesting that RBCs from these species lack molecules, recognized by the NA hemadsorption site, present on human and chicken RBCs. Mutagenesis of the putative hemadsorption site of A/duck/Hong Kong/7/75 N2 NA abolished the high level of hemadsorption activity exhibited by the wild-type protein but also resulted in a 50% reduction of the NA enzymatic activity. A transfectant virus, generated by reverse genetics, containing this mutated NA replicated 10-fold less efficiently in chicken embryo fibroblast cultures than did a transfectant virus expressing the wild-type NA. However, both viruses replicated equally well in Peking ducks. Although conservation of NA hemadsorption activity among avian virus NAs suggests the maintenance of a required function of NA, loss of the activity does not preclude the replication of the virus in an avian host. PMID:9261394

  6. In situ bioremediation of naphthenic acids contaminated tailing pond waters in the athabasca oil sands region--demonstrated field studies and plausible options: a review.

    PubMed

    Quagraine, E K; Peterson, H G; Headley, J V

    2005-01-01

    Currently, there are three industrial plants that recover oil from the lower Athabasca oil sands area, and there are plans in the future for several additional mines. The extraction procedures produce large volumes of slurry wastes contaminated with naphthenic acids (NAs). Because of a "zero discharge" policy the oil sands companies do not release any extraction wastes from their leases. The process-affected waters and fluid tailings contaminated with NAs are contained on-site primarily in large settling ponds. These fluid wastes from the tailing ponds can be acutely and chronically toxic to aquatic organisms, and NAs have been associated with this toxicity. The huge tailings containment area must ultimately be reclaimed, and this is of major concern to the oil sands industry. Some reclamation options have been investigated by both pioneering industries (Syncrude Energy Inc. and Suncor Inc.) with mixed results. The bioremediation techniques have limited success to date in biodegrading NAs to levels below 19 mg/L. Some tailing pond waters have been stored for more than 10 years, and it appears that the remaining high molecular weight NAs are refractory to the natural biodegradation process in the ponds. Some plausible options to further degrade the NAs in the tailings pond water include: bioaugmentation with bacteria selected to degrade the more refractory classes of NAs; the use of attachment materials such as clays to concentrate both the NA and the NA-degrading bacteria in their surfaces and/or pores; synergistic association between algae and bacteria consortia to promote efficient aerobic degradation; and biostimulation with nutrients to promote the growth and activity of the microorganisms. PMID:15756978

  7. [Preparation and evaluation of N-acryloyltris (hydroxymethyl) aminomethane-bonded chromatographic stationary phase].

    PubMed

    Cheng, Xiaodong; Feng, Yuqi

    2015-09-01

    The present study described the preparation of N-acryloyltris (hydroxymethyl) aminomethane-bonded silica (NAS) stationary phase based on "thiol-ene" click chemistry. The composition of the surface grafts of NAS stationary phase was determined by elemental analysis and the results demonstrated the successful introduction of the N-acryloyltris (hydroxymethyl) aminomethane groups to the silica surface. Similar elemental composition of three batches of the NAS stationary phases exhibited good reproducibility of the preparation strategy. A set of standard compounds were employed to investigate the retention mechanism of the NAS stationary phase by three different empirical equations. The results indicated the retention of the tested analytes on the NAS stationary phase was based more on a mixed-mechanism rather than a simple partitioning or adsorption process. Eight compounds were selected to study the hydrophobic and hydrophilic properties of the NAS stationary phase in mobile phase with different ACN contents. Due to its hydrophilic triolacrylamide groups and short hydrophobic alkyl chains, the NAS phase was successfully applied in both reversed-phase liquid chromatography (RPLC) mode and hydrophilic interaction liquid chromatography (HILIC) mode. The influence of flow rate on the column efficiency was compared in these two modes. In contrast to RPLC columns, the overall heights equivalent to a theoretical plate (HETP) in HILIC is weakly dependent on the retention of the analyte and the HETP curve is much flatter in RPLC than in HILIC at larger reduced velocities. Furthermore, the separation of alkylbenzenes, nucleosides and nucleobases, water-soluble vitamins was achieved on the new stationary phase, demonstrating the excellent application potential. PMID:26753276

  8. Colonization of Wheat Roots by an Exopolysaccharide-Producing Pantoea agglomerans Strain and Its Effect on Rhizosphere Soil Aggregation

    PubMed Central

    Amellal, N.; Burtin, G.; Bartoli, F.; Heulin, T.

    1998-01-01

    The effect of bacterial secretion of an exopolysaccharide (EPS) on rhizosphere soil physical properties was investigated by inoculating strain NAS206, which was isolated from the rhizosphere of wheat (Triticum durum L.) growing in a Moroccan vertisol and was identified as Pantoea aglomerans. Phenotypic identification of this strain with the Biotype-100 system was confirmed by amplified ribosomal DNA restriction analysis. After inoculation of wheat seedlings with strain NAS206, colonization increased at the rhizoplane and in root-adhering soil (RAS) but not in bulk soil. Colonization further increased under relatively dry conditions (20% soil water content; matric potential, −0.55 MPa). By means of genetic fingerprinting using enterobacterial repetitive intergenic consensus PCR, we were able to verify that colonies counted as strain NAS206 on agar plates descended from inoculated strain NAS206. The intense colonization of the wheat rhizosphere by these EPS-producing bacteria was associated with significant soil aggregation, as shown by increased ratios of RAS dry mass to root tissue (RT) dry mass (RAS/RT) and the improved water stability of adhering soil aggregates. The maximum effect of strain NAS206 on both the RAS/RT ratio and aggregate stability was measured at 24% average soil water content (matric potential, −0.20 MPa). Inoculated strain NAS206 improved RAS macroporosity (pore diameter, 10 to 30 μm) compared to the noninoculated control, particularly when the soil was nearly water saturated (matric potential, −0.05 MPa). Our results suggest that P. agglomerans NAS206 can play an important role in the regulation of the water content (excess or deficit) of the rhizosphere of wheat by improving soil aggregation. PMID:9758793

  9. Application of experimental poverty measures to the aged.

    PubMed

    Olsen, K A

    1999-01-01

    The U.S. Census Bureau recently released new, experimental measures of poverty based on a National Academy of Sciences (NAS) panel's recommendations. This article examines the effects of the experimental measures on poverty rates among persons aged 65 or older in order to help inform policy debate. Policymakers and analysts use poverty rates to measure the successes and failures of existing programs and to create and defend new policy initiatives. The Census Bureau computes the official rates of poverty using poverty thresholds and definitions of countable income that have changed little since the official poverty measure was adopted in 1965. Amid growing concerns about the adequacy of the official poverty measure, a NAS panel undertook a study of the concepts, methodology, and data needed to measure poverty. The panel concluded in its 1995 report that the current measure no longer provides an accurate picture of relative rates of poverty for different groups in the population or of changes in poverty over time. The panel recommended changes in establishing the poverty thresholds, defining family resources, and obtaining the required data. The Census Bureau report shows how estimated levels of poverty would differ from the official level as specific recommendations of the NAS panel are implemented individually and how estimated trends would differ when many recommendations are implemented simultaneously. It computes nonstandardized and standardized poverty rates. (The latter constrains the overall poverty rate under the experimental measures to match the official rate.) This article reports poverty rates that have not been standardized and provides considerably more detail than the Census report about the effects of the experimental measures on poverty among the aged. It examines the effects of changing the poverty thresholds and the items included or excluded from the definition of available resources. It also explores the effects of the experimental measures on

  10. Scheduled feeding versus the light-dark cycle on the rhythms of circulating tryptophan, serotonin and N-acetylserotonin in rats.

    PubMed

    Ho, A K; Chik, C L; Brown, G M

    1985-10-28

    Both the environmental light-dark cycle and scheduled feeding can act as entrainers of biological rhythms. The present study investigated the relative potency of these two environmental cues in entraining the rhythms of circulating tryptophan (TRP), serotonin (5HT) and N-acetylserotonin (NAS). Four groups of rats were subjected for one month to an identical light-dark cycle of 14 h light and 10 h dark with food availability restricted to the 3 h period beginning 2 h after onset of light or onset of darkness. Two groups of animals were food deprived on the day of experiment. The 24 h rhythms of serum TRP, 5HT and NAS were determined. Serum TRP showed a sharp increase after food presentation and declined gradually to a trough just before feeding. Withholding food on the day of experiment abolished this increase. The trough of serum 5HT occurred just before feeding, increased gradually after feeding and peaked 10-13 h afterwards. Serum NAS levels, however, demonstrated an anticipatory rise before feeding, which peaked during feeding and declined to a trough 8 h afterwards. Unlike TRP, withholding food had no effect on either the 5HT or the NAS rhythm. These results indicated that feeding schedule was the common and stronger entrainer for the rhythms of serum TRP, 5HT and NAS. However, each indole had a different rhythm pattern in relation to the feeding schedule which could not be explained by a simple precursor-product relationship.

  11. Environmental, health, and safety issues of sodium-sulfur batteries for electric and hybrid vehicles

    SciTech Connect

    Mark, J

    1992-11-01

    This report is the last of four volumes that identify and assess the environmental, health, and safety issues that may affect the commercial-scale use of sodium-sulfur (Na/S) battery technology as the energy source in electric and hybrid vehicles. The reports are intended to help the Electric and Hybrid Propulsion Division of the Office of Transportation Technologies in the US Department of Energy (DOE/EHP) determine the direction of its research, development, and demonstration (RD D) program for Na/S battery technology. The reports review the status of Na/S battery RD D and identify potential hazards and risks that may require additional research or that may affect the design and use of Na/S batteries. This volume covers the in-vehicle safety issues of electric vehicles powered by Na/S batteries. The report is based on a review of the literature and on discussions with experts at DOE, national laboratories and agencies, and private industry. It has three major goals: (1) to identify the unique hazards associated with electric vehicle (EV) use; (2) to describe the existing standards, regulations, and guidelines that are or could be applicable to these hazards; and (3) to discuss the adequacy of the existing requirements in addressing the safety concerns of EVs.

  12. Environmental, health, and safety issues of sodium-sulfur batteries for electric and hybrid vehicles. Volume 4, In-vehicle safety

    SciTech Connect

    Mark, J.

    1992-11-01

    This report is the last of four volumes that identify and assess the environmental, health, and safety issues that may affect the commercial-scale use of sodium-sulfur (Na/S) battery technology as the energy source in electric and hybrid vehicles. The reports are intended to help the Electric and Hybrid Propulsion Division of the Office of Transportation Technologies in the US Department of Energy (DOE/EHP) determine the direction of its research, development, and demonstration (RD&D) program for Na/S battery technology. The reports review the status of Na/S battery RD&D and identify potential hazards and risks that may require additional research or that may affect the design and use of Na/S batteries. This volume covers the in-vehicle safety issues of electric vehicles powered by Na/S batteries. The report is based on a review of the literature and on discussions with experts at DOE, national laboratories and agencies, and private industry. It has three major goals: (1) to identify the unique hazards associated with electric vehicle (EV) use; (2) to describe the existing standards, regulations, and guidelines that are or could be applicable to these hazards; and (3) to discuss the adequacy of the existing requirements in addressing the safety concerns of EVs.

  13. Development of an electrochemical biosensor for the detection of an ADP-ribosylating toxin, exo A from Pseudomonas aeruginosa

    NASA Astrophysics Data System (ADS)

    Enríquez, Y.; Negrón, Y.; Navarreto, M.; Guadalupe, A. R.

    2013-03-01

    A free radical copolymerization of Styrene (Sty) and acrylic acid N-hydroxysuccinimide ester (NAS) has been done in a range of 10:90 to 90:10 (Sty:NAS) molar ratios. The FT-IR spectra for all seven copolymers showed the absorption peaks for the carbonyl signals of the ester and the amide in NAS (1773 cm-1 and 1727 cm-1 respectively), the styrene aromatic signal (1494 cm-1) and the disappearance of the absorption peak for the vinyl group in both monomers (1629 cm-1). HPLC-UV results showed an increment in the average molecular weight with an increase in the molar ratio of the styrene monomer, from 1528.51 g/mol for 10:90 Sty:NAS to 7141.67 g/mol for 90:10 Sty:NAS. These copolymers will be used to generate films on carbon surfaces to anchor a β-NAD+ electroactive analog. Also, a Ferrocene-labeled NAAD (Fc-NAAD) was prepared by attaching Ferrocene Succinimide (Fc-NHS) to the primary amine in the adenine moiety of the cofactor. Osteryoung Squatre Wave Voltammetry (OSWV) of the new Fc-NAAD showed an anodic peak in 320 mV and the cyclic voltammetry (CV) showed chemical reversibility and electrochemical quasi-reversibility.

  14. Validation of the Novaco Anger Scale-Provocation Inventory (Danish) With Nonclinical, Clinical, and Offender Samples.

    PubMed

    Moeller, Stine Bjerrum; Novaco, Raymond W; Heinola-Nielsen, Vivian; Hougaard, Helle

    2016-10-01

    Anger has high prevalence in clinical and forensic settings, and it is associated with aggressive behavior and ward atmosphere on psychiatric units. Dysregulated anger is a clinical problem in Danish mental health care systems, but no anger assessment instruments have been validated in Danish. Because the Novaco Anger Scale and Provocation Inventory (NAS-PI) has been extensively validated with different clinical populations and lends itself to clinical case formulation, it was selected for translation and evaluation in the present multistudy project. Psychometric properties of the NAS-PI were investigated with samples of 477 nonclinical, 250 clinical, 167 male prisoner, and 64 male forensic participants. Anger prevalence and its relationship with other anger measures, anxiety/depression, and aggression were examined. NAS-PI was found to have high reliability, concurrent validity, and discriminant validity, and its scores discriminated the samples. High scores in the offender group demonstrated the feasibility of obtaining self-report assessments of anger with this population. Retrospective and prospective validity of the NAS were tested with the forensic patient sample regarding physically aggressive behavior in hospital. Regression analyses showed that higher scores on NAS increase the risk of having acted aggressively in the past and of acting aggressively in the future.

  15. Application of a solar UV/chlorine advanced oxidation process to oil sands process-affected water remediation.

    PubMed

    Shu, Zengquan; Li, Chao; Belosevic, Miodrag; Bolton, James R; El-Din, Mohamed Gamal

    2014-08-19

    The solar UV/chlorine process has emerged as a novel advanced oxidation process for industrial and municipal wastewaters. Currently, its practical application to oil sands process-affected water (OSPW) remediation has been studied to treat fresh OSPW retained in large tailings ponds, which can cause significant adverse environmental impacts on ground and surface waters in Northern Alberta, Canada. Degradation of naphthenic acids (NAs) and fluorophore organic compounds in OSPW was investigated. In a laboratory-scale UV/chlorine treatment, the NAs degradation was clearly structure-dependent and hydroxyl radical-based. In terms of the NAs degradation rate, the raw OSPW (pH ∼ 8.3) rates were higher than those at an alkaline condition (pH = 10). Under actual sunlight, direct solar photolysis partially degraded fluorophore organic compounds, as indicated by the qualitative synchronous fluorescence spectra (SFS) of the OSPW, but did not impact NAs degradation. The solar/chlorine process effectively removed NAs (75-84% removal) and fluorophore organic compounds in OSPW in the presence of 200 or 300 mg L(-1) OCl(-). The acute toxicity of OSPW toward Vibrio fischeri was reduced after the solar/chlorine treatment. However, the OSPW toxicity toward goldfish primary kidney macrophages after solar/chlorine treatment showed no obvious toxicity reduction versus that of untreated OSPW, which warrants further study for process optimization.

  16. Mycoplasmas and cancer: focus on nucleoside metabolism

    PubMed Central

    Vande Voorde, Johan; Balzarini, Jan; Liekens, Sandra

    2014-01-01

    The standard of care for patients suffering cancer often includes treatment with nucleoside analogues (NAs). NAs are internalized by cell-specific nucleobase/nucleoside transporters and, after enzymatic activation (often one or more phosphorylation steps), interfere with cellular nucleo(s)(t)ide metabolism and DNA/RNA synthesis. Therefore, their efficacy is highly dependent on the expression and activity of nucleo(s)(t)ide-metabolizing enzymes, and alterations thereof (e.g. by down/upregulated expression or mutations) may change the susceptibility to NA-based therapy and/or confer drug resistance. Apart from host cell factors, several other variables including microbial presence may determine the metabolome (i.e. metabolite concentrations) of human tissues. Studying the diversity of microorganisms that are associated with the human body has already provided new insights in several diseases (e.g. diabetes and inflammatory bowel disease) and the metabolic exchange between tissues and their specific microbiota was found to affect the bioavailability and toxicity of certain anticancer drugs, including NAs. Several studies report a preferential colonization of tumor tissues with some mycoplasma species (mostly Mycoplasma hyorhinis). These prokaryotes are also a common source of cell culture contamination and alter the cytostatic activity of some NAs in vitro due to the expression of nucleoside-catabolizing enzymes. Mycoplasma infection may therefore bias experimental work with NAs, and their presence in the tumor microenvironment could be of significance when optimizing nucleoside-based cancer treatment. PMID:26417262

  17. Neonatal Abstinence Syndrome: Influence of a Combined Inpatient/Outpatient Methadone Treatment Regimen on the Average Length of Stay of a Medicaid NICU Population.

    PubMed

    Lee, Jerry; Hulman, Sonia; Musci, Michael; Stang, Ellen

    2015-10-01

    Prescription opioid and heroin abuse have been increasing steadily year after year, and continue to be a serious national problem. A sequela of the increase in opioid abuse has been an increase in the number of infants born with opioid dependence. These infants often require costly, prolonged stays in the neonatal intensive care unit (NICU) for drug withdrawal treatment. The authors studied a population of infants from a large Medicaid health plan who were born with neonatal abstinence syndrome (NAS) secondary to in utero opioid exposure to assess the average length of stay in the NICU, and to determine the variables that may account for differences in interinstitutional lengths of stay. The overall average length of stay for NAS was 21.1 days for the 139 infants included in the study. Analysis of the medication used for treatment revealed that infants who were treated with a combined inpatient/outpatient regimen with methadone had an average length of stay of 11.4 days versus 25.1 days for infants who were treated entirely as inpatients (P<0.001), a 55% reduction in average length of stay. In 2009 there were an estimated 13,600 cases of NAS in the United States at a cost of $53,000 per case. A 55% reduction in length of stay corresponds to $396 million in annual savings for the treatment of NAS. Development of successful combined inpatient/outpatient management programs for NAS warrants further consideration.

  18. N-Acetyl-Serotonin Protects HepG2 Cells from Oxidative Stress Injury Induced by Hydrogen Peroxide

    PubMed Central

    Jiang, Jiying; Yu, Shuna; Jiang, Zhengchen; Liang, Cuihong; Yu, Wenbo; Li, Jin; Du, Xiaodong; Wang, Hailiang; Gao, Xianghong; Wang, Xin

    2014-01-01

    Oxidative stress plays an important role in the pathogenesis of liver diseases. N-Acetyl-serotonin (NAS) has been reported to protect against oxidative damage, though the mechanisms by which NAS protects hepatocytes from oxidative stress remain unknown. To determine whether pretreatment with NAS could reduce hydrogen peroxide- (H2O2-) induced oxidative stress in HepG2 cells by inhibiting the mitochondrial apoptosis pathway, we investigated the H2O2-induced oxidative damage to HepG2 cells with or without NAS using MTT, Hoechst 33342, rhodamine 123, Terminal dUTP Nick End Labeling Assay (TUNEL), dihydrodichlorofluorescein (H2DCF), Annexin V and propidium iodide (PI) double staining, immunocytochemistry, and western blot. H2O2 produced dramatic injuries in HepG2 cells, represented by classical morphological changes of apoptosis, increased levels of malondialdehyde (MDA) and intracellular reactive oxygen species (ROS), decreased activity of superoxide dismutase (SOD), and increased activities of caspase-9 and caspase-3, release of cytochrome c (Cyt-C) and apoptosis-inducing factor (AIF) from mitochondria, and loss of membrane potential (ΔΨm). NAS significantly inhibited H2O2-induced changes, indicating that it protected against H2O2-induced oxidative damage by reducing MDA levels and increasing SOD activity and that it protected the HepG2 cells from apoptosis through regulating the mitochondrial apoptosis pathway, involving inhibition of mitochondrial hyperpolarization, release of mitochondrial apoptogenic factors, and caspase activity. PMID:25013541

  19. Neonatal Abstinence Syndrome: Presentation and Treatment Considerations.

    PubMed

    Kaltenbach, Karol; Jones, Hendree E

    2016-01-01

    The increase in opioid use among the general population is reflected in pregnant women and neonatal abstinence syndrome (NAS) statistics. This increase has produced an unprecedented focus on NAS from both the political-judicial sphere and the medical community. Under the banner of fetal protection, judges and prosecutors have implemented punitive approaches against women who use prescribed and nonprescribed opioids during pregnancy, including arrest, civil commitment, detention, prosecution, and loss of custody or termination of parental rights. Within the medical community, questions have been raised regarding protocols to detect prenatal drug exposure at delivery, NAS treatment protocols, the need for quality-improvement strategies to standardize care and reduce length of stay for mother and infant, and the benefits of engaging the mother in the care of her infant. It is not uncommon for the expression of strong discordant views on these issues both between and among these political-judicial and medical constituencies. Closely examining the issues often reveal a lack of understanding of substance use disorders, their treatment, and the occurrence and treatment of NAS. This study provides an in-depth examination of NAS, including variations in presentation and factors that impact the efficacy of treatment, and also identifying questions that remain unanswered. Finally, 4 key areas on which future research should focus to guide both medical care and public policy are discussed. PMID:26974659

  20. Recombinant Klebsiella oxytoca strains with improved efficiency in removal of high nitrate loads

    SciTech Connect

    Pinar, G.; Ramos, J.L.

    1998-12-01

    Klebsiella oxytoca CECT 4460 removes high nitrate loads from industrial wastewaters without accumulation of nitrite under optimal culture conditions; however, under nonoptimal conditions nitrite accumulates. This situation reflects an in vivo-limited functioning of nitrite reductase in this strain. As a way to overcome this limitation, an increase in the nitrite reductase gene dose in K. oxytoca CECT 4460 was considered. To achieve this, the authors cloned and transferred into this strain the Klebsiella pneumoniae nasB gene, which encodes assimilatory nitrite reductase. The delivery vector was either the wide-host-range plasmid pUPE2, in which the nasB gene is expressed from the Escherichia coli P{sub lac} promoter, or a mini-Tn5-Km vector, which upon random insertion in the host chromosome allowed expression of the nasB gene from an unidentified chromosomal host promoter. The effect of the increase in the dose of the nasB gene in K. oxytoca CECT 4460 on the accumulation of nitrite in the culture medium was tested in two recombinant strains. The results obtained showed that K. oxytoca CECT 4460 bearing pUPE2 accumulated 88% less nitrite than the wild-type strain, while the recombinant strain bearing the K. pneumoniae nasB gene in the host chromosome showed a 25% lower level of nitrite accumulation in the culture medium than that of the wild type.

  1. Modified biopolymers as sorbents for the removal of naphthenic acids from oil sands process affected water (OSPW).

    PubMed

    Arshad, Muhammad; Khosa, M A; Siddique, Tariq; Ullah, Aman

    2016-11-01

    Oil sands operations consume large volumes of water in bitumen extraction process and produce tailings that express pore water to the surface of tailings ponds known as oil sands process-affected water (OSPW). The OSPW is toxic and cannot be released into the environment without treatment. In addition to metals, dissolved solids, dissolved gases, hydrocarbons and polyaromatic compounds etc., OSPW also contains a complex mixture of dissolved organic acids, referred to as naphthenic acids (NAs). The NAs are highly toxic and react with metals to develop highly corrosive functionalities which cause corrosion in the oil sands processing and refining processes. We have chemically modified keratin biopolymer using polyhedral oligomeric silsesquioxanes (POSS) nanocages and goethite dopant to unfold keratinous structure for improving functionality. The untreated neat keratin and two modified sorbents were characterized to investigate structural, morphological, dimensional and thermal properties. These sorbents were then tested for the removal of NAs from OSPW. The NAs were selectively extracted and quantified before and after sorption process. The biosorption capacity (Q), rejection percentage (R%) and isotherm models were studied to investigate NAs removal efficiency of POSS modified keratin biopolymer (PMKB) and goethite modified keratin biopolymer (GMKB) from aliquots of OSPW. PMID:27552693

  2. Biodegradation of naphthenic acid surrogates by axenic cultures.

    PubMed

    Yue, Siqing; Ramsay, Bruce A; Ramsay, Juliana A

    2015-07-01

    This is the first study to report that bacteria from the genera Ochrobactrum, Brevundimonas and Bacillus can be isolated by growth on naphthenic acids (NAs) extracted from oil sands process water (OSPW). These pure cultures were screened for their ability to use a range of aliphatic, cyclic and aromatic NA surrogates in 96-well microtiter plates using water-soluble tetrazolium redox dyes (Biolog Redox Dye H) as the indicator of metabolic activity. Of the three cultures, Ochrobactrum showed most metabolic activity on the widest range of NA surrogates. Brevundomonas and especially Ochrobactrum had higher metabolic activity on polycyclic aromatic compounds than other classes of NA surrogates. Bacillus also oxidized a wide range of NA surrogates but not as well as Ochrobactrum. Using this method to characterize NA utilisation, one can identify which NAs or NA classes in OSPW are more readily degraded. Since aromatic NAs have been shown to have an estrogenic effect and polycyclic monoaromatic compounds have been suggested to pose the greatest environmental threat among the NAs, these bacterial genera may play an important role in detoxification of OSPW. Furthermore, this study demonstrates that bacteria belonging to the genera Ochrobactrum and Bacillus can also degrade surrogates of tricyclic NAs.

  3. Mineralization of naphtenic acids with thermally-activated persulfate: The important role of oxygen.

    PubMed

    Xu, Xiyan; Pliego, Gema; Zazo, Juan A; Casas, Jose A; Rodriguez, Juan J

    2016-11-15

    This study reports on the mineralization of model naphtenic acids (NAs) in aqueous solution by catalyst-free thermally-activated persulfate (PS) oxidation. These species are found to be pollutants in oil sands process-affected waters. The NAs tested include saturated-ring (cyclohexanecarboxylic and cyclohexanebutyric acids) and aromatic (2-naphthoic and 1,2,3,4-tetrahydro-2-naphthoic acids) structures, at 50mgL(-1)starting concentration. The effect of PS dose within a wide range (10-100% of the theoretical stoichiometric) and working temperature (40-97°C) was investigated. At 80°C and intitial pH=8 complete mineralization of the four NAs was achieved with 40-60% of the stoichiometric PS dose. This is explained because of the important contribution of oxygen, which was experimentally verified and was found to be more effective toward the NAs with a single cyclohexane ring than for the bicyclic aromatic-ring-bearing ones. The effect of chloride and bicarbonate was also checked. The former showed negative effect on the degradation rate of NAs whereas it was negligible or even positive for bicarbonate. The rate of mineralization was well described by simple pseudo-first order kinetics with values of the rate constants normalized to the PS dose within the range of 0.062-0.099h(-1). Apparent activation energy values between 93.7-105.3kJmol(-1) were obtained. PMID:27442986

  4. SODIUM ALUMINOSILICATE SOLIDS AFFINITY FOR CESIUM AND ACTINIDES

    SciTech Connect

    Peters, T; Bill Wilmarth, B; Samuel Fink, S

    2007-07-31

    Washed sodium-aluminosilicate (NAS) solids at initial concentrations of 3.55 and 5.4 g/L sorb or uptake virtually no cesium over 288 hours, nor do any NAS solids generated during that time. These concentrations of solids are believed to conservatively bound current and near-term operations. Hence, the NAS solids should not have affected measurements of the cesium during the mass transfer tests and there is minimal risk of accumulating cesium during routine operations (and hence posing a gamma radiation exposure risk in maintenance). With respect to actinide uptake, it appears that NAS solids sorb minimal quantities of uranium - up to 58 mg U per kg NAS solid. The behavior with plutonium is less well understood. Additional study may be needed for radioactive operations relative to plutonium or other fissile component sorption or trapping by the solids. We recommend this testing be incorporated in the planned tests using samples from Tank 25F and Tank 49H to extend the duration to bound expected inventory time for solution.

  5. Characterization of Uranium Solids Precipitated with Aluminosilicates

    SciTech Connect

    DUFF, MC

    2004-01-09

    At the Savannah River Site (SRS), the High-Level Waste (HLW) Tank Farms store and process high-level liquid radioactive wastes from the Canyons and recycle water from the Defense Waste Processing Facility. The waste is concentrated using evaporators to minimize the volume of space required for HLW storage. Recently, the 2H Evaporator was shutdown due to the crystallization of sodium aluminosilicate (NAS) solids (such as cancrinite and sodalite) that contained close to 10 weight percent of elementally-enriched uranium (U). Prior to extensive cleaning,the evaporator deposits resided on the evaporator walls and other exposed internal surfaces within the evaporator pot. Our goal is to support the basis for the continued safe operation of SRS evaporators and to gain more information that could be used to help mitigate U accumulation during evaporator operation. To learn more about the interaction between U(VI) and NAS in HLW salt solutions, we performed several fundamental studies to examine the mechanisms of U accumulation with NAS in highly caustic solutions. This larger group of studies focused on the following processes: co-precipitation/structural incorporation, sorption, and precipitation (with or without NAS), which will be reviewed in this presentation. We will present and discuss local atomic structural characterization data about U that has been co-precipitated with NAS solids (such as amorphous zeolite precursor material and sodalite) using X-ray absorption fine-structure (XAFS) spectroscopic techniques.

  6. Neonatal Abstinence Syndrome Following Tianeptine Dependence During Pregnancy.

    PubMed

    Bence, Camille; Bonord, Alexandre; Rebillard, Camille; Vaast, Pascal; Alexandre, Charlotte; Jardri, Renaud; Rolland, Benjamin

    2016-01-01

    Tianeptine, an atypical antidepressant, has been found to exhibit a potential for abuse. The use of therapeutic doses of tianeptine during pregnancy has never raised safety concerns. However, the impact of tianeptine abuse on the mother-child dyad has never been assessed. We report herein the case of a female patient who presented with dependence on tianeptine, with the use of >650 mg of the drug per day. She had 2 successive pregnancies with similar doses. The state of dependence remained unidentified throughout the first pregnancy, but just after delivery, her full-term newborn exhibited unexpected neonatal abstinence syndrome (NAS). The NAS was successfully treated with morphine, although both the mother's and newborn's urine drug screen was negative. The causality of tianeptine in inducing NAS was retrospectively assessed as "probable" by using a validated causality algorithm. During the second pregnancy, this patient sought addiction treatment and was admitted for residential detoxification treatment in her seventh month of pregnancy. Delivery occurred at full term with a low birth weight neonate. No further developmental insults or medical problems were subsequently identified in the 2 children. Maternal tianeptine dependence during pregnancy may induce a type of NAS that mimics opiate NAS. This finding appears to be consistent with a recent finding of the agonist action of tianeptine on the opiate μ-receptor. PMID:26659818

  7. The effect of oil sands process-affected water and model naphthenic acids on photosynthesis and growth in Emiliania huxleyi and Chlorella vulgaris.

    PubMed

    Beddow, Jessica; Johnson, Richard J; Lawson, Tracy; Breckels, Mark N; Webster, Richard J; Smith, Ben E; Rowland, Steven J; Whitby, Corinne

    2016-02-01

    Naphthenic acids (NAs) are among the most toxic organic pollutants present in oil sands process waters (OSPW) and enter marine and freshwater environments through natural and anthropogenic sources. We investigated the effects of the acid extractable organic (AEO) fraction of OSPW and individual surrogate NAs, on maximum photosynthetic efficiency of photosystem II (PSII) (FV/FM) and cell growth in Emiliania huxleyi and Chlorella vulgaris as representative marine and freshwater phytoplankton. Whilst FV/FM in E. huxleyi and C. vulgaris was not inhibited by AEO, exposure to two surrogate NAs: (4'-n-butylphenyl)-4-butanoic acid (n-BPBA) and (4'-tert-butylphenyl)-4-butanoic acid (tert-BPBA), caused complete inhibition of FV/FM in E. huxleyi (≥10 mg L(-1)n-BPBA; ≥50 mg L(-1)tert-BPBA) but not in C. vulgaris. Growth rates and cell abundances in E. huxleyi were also reduced when exposed to ≥10 mg L(-1)n- and tert-BPBA; however, higher concentrations of n- and tert-BPBA (100 mg L(-1)) were required to reduce cell growth in C. vulgaris. AEO at ≥10 mg L(-1) stimulated E. huxleyi growth rate (p ≤ 0.002), yet had no apparent effect on C. vulgaris. In conclusion, E. huxleyi was generally more sensitive to NAs than C. vulgaris. This report provides a better understanding of the physiological responses of phytoplankton to NAs which will enable improved monitoring of NA pollution in aquatic ecosystems in the future.

  8. Elevated Nicotianamine Levels in Arabidopsis halleri Roots Play a Key Role in Zinc Hyperaccumulation[W

    PubMed Central

    Deinlein, Ulrich; Weber, Michael; Schmidt, Holger; Rensch, Stefan; Trampczynska, Aleksandra; Hansen, Thomas H.; Husted, Søren; Schjoerring, Jan K.; Talke, Ina N.; Krämer, Ute; Clemens, Stephan

    2012-01-01

    Zn deficiency is among the leading health risk factors in developing countries. Breeding of Zn-enriched crops is expected to be facilitated by molecular dissection of plant Zn hyperaccumulation (i.e., the ability of certain plants to accumulate Zn to levels >100-fold higher than normal plants). The model hyperaccumulators Arabidopsis halleri and Noccaea caerulescens share elevated nicotianamine synthase (NAS) expression relative to nonaccumulators among a core of alterations in metal homeostasis. Suppression of Ah-NAS2 by RNA interference (RNAi) resulted in strongly reduced root nicotianamine (NA) accumulation and a concomitant decrease in root-to-shoot translocation of Zn. Speciation analysis by size-exclusion chromatography coupled to inductively coupled plasma mass spectrometry showed that the dominating Zn ligands in roots were NA and thiols. In NAS2-RNAi plants, a marked increase in Zn-thiol species was observed. Wild-type A. halleri plants cultivated on their native soil showed elemental profiles very similar to those found in field samples. Leaf Zn concentrations in NAS2-RNAi lines, however, did not reach the Zn hyperaccumulation threshold. Leaf Cd accumulation was also significantly reduced. These results demonstrate a role for NAS2 in Zn hyperaccumulation also under near-natural conditions. We propose that NA forms complexes with Zn(II) in root cells and facilitates symplastic passage of Zn(II) toward the xylem. PMID:22374395

  9. Silver-Ion Solid Phase Extraction Separation of Classical, Aromatic, Oxidized, and Heteroatomic Naphthenic Acids from Oil Sands Process-Affected Water.

    PubMed

    Huang, Rongfu; Chen, Yuan; Gamal El-Din, Mohamed

    2016-06-21

    The separation of classical, aromatic, oxidized, and heteroatomic (sulfur-containing) naphthenic acid (NA) species from unprocessed and ozone-treated oil sands process-affected water (OSPW) was performed using silver-ion (Ag-ion) solid phase extraction (SPE) without the requirement of pre-methylation for NAs. OSPW samples before SPE and SPE fractions were characterized using ultra performance liquid chromatography ion mobility time-of-flight mass spectrometry (UPLC-IM-TOFMS) to corroborate the separation of distinct NA species. The mass spectrum identification applied a mass tolerance of ±1.5 mDa due to the mass errors of NAs were measured within this range, allowing the identification of O2S-NAs from O2-NAs. Moreover, separated NA species facilitated the tandem mass spectrometry (MS/MS) characterization of NA compounds due to the removal of matrix and a simplified composition. MS/MS results showed that classical, aromatic, oxidized, and sulfur-containing NA compounds were eluted into individual SPE fractions. Overall results indicated that the separation of NA species using Ag-ion SPE is a valuable method for extracting individual NA species that are of great interest for environmental toxicology and wastewater treatment research, to conduct species-specific studies. Furthermore, the separated NA species on the milligram level could be widely used as the standard materials for environmental monitoring of NAs from various contamination sites. PMID:27183033

  10. Neonatal Abstinence Syndrome Following Tianeptine Dependence During Pregnancy.

    PubMed

    Bence, Camille; Bonord, Alexandre; Rebillard, Camille; Vaast, Pascal; Alexandre, Charlotte; Jardri, Renaud; Rolland, Benjamin

    2016-01-01

    Tianeptine, an atypical antidepressant, has been found to exhibit a potential for abuse. The use of therapeutic doses of tianeptine during pregnancy has never raised safety concerns. However, the impact of tianeptine abuse on the mother-child dyad has never been assessed. We report herein the case of a female patient who presented with dependence on tianeptine, with the use of >650 mg of the drug per day. She had 2 successive pregnancies with similar doses. The state of dependence remained unidentified throughout the first pregnancy, but just after delivery, her full-term newborn exhibited unexpected neonatal abstinence syndrome (NAS). The NAS was successfully treated with morphine, although both the mother's and newborn's urine drug screen was negative. The causality of tianeptine in inducing NAS was retrospectively assessed as "probable" by using a validated causality algorithm. During the second pregnancy, this patient sought addiction treatment and was admitted for residential detoxification treatment in her seventh month of pregnancy. Delivery occurred at full term with a low birth weight neonate. No further developmental insults or medical problems were subsequently identified in the 2 children. Maternal tianeptine dependence during pregnancy may induce a type of NAS that mimics opiate NAS. This finding appears to be consistent with a recent finding of the agonist action of tianeptine on the opiate μ-receptor.

  11. Tandem laser ablation synthesis in solution-galvanic replacement reaction (LASiS-GRR) for the production of PtCo nanoalloys as oxygen reduction electrocatalysts

    NASA Astrophysics Data System (ADS)

    Hu, Sheng; Tian, Mengkun; Ribeiro, Erick L.; Duscher, Gerd; Mukherjee, Dibyendu

    2016-02-01

    We have developed tandem laser ablation synthesis in solution-galvanic replacement reaction (LASiS-GRR) technique as a facile, green yet, efficient route to synthesize spherical PtCo NAs with varied sizes, compositions and degrees of alloying. The transformative concept here is the ability to design these nanostructured alloys by tuning the high-energy physico-chemical conditions emerging from liquid-confined, laser-induced plasma, and the solution-phase reaction pathways dictated by pH conditions and precursor salt concentrations. The resultant NAs exhibit uniformly alloyed cores with a Pt-rich shell of a few nanometers, as demonstrated by the electron energy loss spectroscopy (EELS) mapping. Such core-shell structure along with high degrees of alloying in these PtCo NAs promote their outstanding electrocatalytic ORR activities in acid electrolytes. Specifically, compared to commercial Pt/C catalysts, the PtCo NAs with Co molar ratio of 22.1% indicate a c.a. 3 and 6-fold increase in mass and specific activities respectively. Such enhanced ORR activities are attributed to the efficacy of tandem LASiS-GRR route to rationally tune size distributions/compositional ratios and alloying degrees of the NAs without the use of any surfactants or reducing agents that are otherwise indispensable in chemical synthesis methods, but harmful for catalytic performances.

  12. Modified biopolymers as sorbents for the removal of naphthenic acids from oil sands process affected water (OSPW).

    PubMed

    Arshad, Muhammad; Khosa, M A; Siddique, Tariq; Ullah, Aman

    2016-11-01

    Oil sands operations consume large volumes of water in bitumen extraction process and produce tailings that express pore water to the surface of tailings ponds known as oil sands process-affected water (OSPW). The OSPW is toxic and cannot be released into the environment without treatment. In addition to metals, dissolved solids, dissolved gases, hydrocarbons and polyaromatic compounds etc., OSPW also contains a complex mixture of dissolved organic acids, referred to as naphthenic acids (NAs). The NAs are highly toxic and react with metals to develop highly corrosive functionalities which cause corrosion in the oil sands processing and refining processes. We have chemically modified keratin biopolymer using polyhedral oligomeric silsesquioxanes (POSS) nanocages and goethite dopant to unfold keratinous structure for improving functionality. The untreated neat keratin and two modified sorbents were characterized to investigate structural, morphological, dimensional and thermal properties. These sorbents were then tested for the removal of NAs from OSPW. The NAs were selectively extracted and quantified before and after sorption process. The biosorption capacity (Q), rejection percentage (R%) and isotherm models were studied to investigate NAs removal efficiency of POSS modified keratin biopolymer (PMKB) and goethite modified keratin biopolymer (GMKB) from aliquots of OSPW.

  13. History of the numerical aerodynamic simulation program

    NASA Technical Reports Server (NTRS)

    Peterson, Victor L.; Ballhaus, William F., Jr.

    1987-01-01

    The Numerical Aerodynamic Simulation (NAS) program has reached a milestone with the completion of the initial operating configuration of the NAS Processing System Network. This achievement is the first major milestone in the continuing effort to provide a state-of-the-art supercomputer facility for the national aerospace community and to serve as a pathfinder for the development and use of future supercomputer systems. The underlying factors that motivated the initiation of the program are first identified and then discussed. These include the emergence and evolution of computational aerodynamics as a powerful new capability in aerodynamics research and development, the computer power required for advances in the discipline, the complementary nature of computation and wind tunnel testing, and the need for the government to play a pathfinding role in the development and use of large-scale scientific computing systems. Finally, the history of the NAS program is traced from its inception in 1975 to the present time.

  14. CFD Data Sets on the WWW for Education and Testing

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    The Numerical Aerodynamic Simulation (NAS) Systems Division at NASA Ames Research Center has begun the development of a Computational Fluid Dynamics (CFD) data set archive on the World Wide Web (WWW) at URL http://www.nas.nasa.gov/NAS/DataSets/. Data sets are integrated with related information such as research papers, metadata, visualizations, etc. In this paper, four classes of users are identified and discussed: students, visualization developers, CFD practitioners, and management. Bandwidth and security issues are briefly reviewed and the status of the archive as of May 1995 is examined. Routine network distribution of data sets is likely to have profound implications for the conduct of science. The exact nature of these changes is subject to speculation, but the ability for anyone to examine the data, in addition to the investigator's analysis, may well play an important role in the future.

  15. Sodium-sulfur battery flight experiment definition study

    NASA Technical Reports Server (NTRS)

    Chang, Rebecca; Minck, Robert

    1989-01-01

    NaS batteries have been identified as the most likely successor to space Ni-H2 or Ni-Cd batteries, primarily due to a mass reduction by a factor 2 to 3 over Ni-H2 and by a factor of 4 over Ni-Cd. This yields major launch cost reductions or payload mass improvements. NaS batteries support NASA OAST's proposed Civil Space Technology Initiative goal of a factor of two improvement in spacecraft 2000 initiative. Since Ni-H2 and Ni-Cd batteries have been space flight proven, it is essential to have the flight experiment to establish a national space technology base to demonstrate the operation of the NaS battery for space applications.

  16. A Look at the Impact of High-End Computing Technologies on NASA Missions

    NASA Technical Reports Server (NTRS)

    Biswas, Rupak; Dunbar, Jill; Hardman, John; Bailey, F. Ron; Wheeler, Lorien; Rogers, Stuart

    2012-01-01

    From its bold start nearly 30 years ago and continuing today, the NASA Advanced Supercomputing (NAS) facility at Ames Research Center has enabled remarkable breakthroughs in the space agency s science and engineering missions. Throughout this time, NAS experts have influenced the state-of-the-art in high-performance computing (HPC) and related technologies such as scientific visualization, system benchmarking, batch scheduling, and grid environments. We highlight the pioneering achievements and innovations originating from and made possible by NAS resources and know-how, from early supercomputing environment design and software development, to long-term simulation and analyses critical to design safe Space Shuttle operations and associated spinoff technologies, to the highly successful Kepler Mission s discovery of new planets now capturing the world s imagination.

  17. Chlorinated contaminants in chorio-allantoic membranes from great blue heron eggs at Whidbey Island Naval Air Station.

    PubMed

    Cobb, G P; Norman, D M; Miller, M W; Brewer, L W; Johnston, R K

    1995-01-01

    Chorio-allantoic membranes (CAMs) were collected and analyzed for chlorinated hydrocarbons as part of a wildlife toxicology demonstration project at Naval Air Station (NAS) Whidbey Island, Washington, USA. Concentrations of DDT, DDE, DDD, Aroclor 1254, and Aroclor 1260 were found at concentrations below 0.4 ppm for 13 of 14 samples. The low correlations among DDT and its metabolites in CAMs suggest herons are not being exposed to a consistent source of these compounds. Comparison of chlorinated hydrocarbon data for CAMs from three Puget Sound heron colonies, NAS Whidbey, Samish Island and Dumas Bay, indicates contaminant burdens in herons from NAS Whidbey and Samish Island are significantly lower than burdens in herons from Dumas Bay.

  18. Biodegradable Three-Layered Micelles and Injectable Hydrogels.

    PubMed

    Abebe, Daniel G; Kandil, Rima; Kraus, Teresa; Elsayed, Maha; Fujiwara, Tomoko; Merkel, Olivia M

    2016-01-01

    Polymeric micelles have found a growing interest as gene vectors due to the serious safety concerns associated with viral vectors. In particular, the cationic polymer polyethylene imine (PEI) has shown relatively high condensation and transfection efficiencies. Additionally, polyethylene glycol (PEG) modification of polymeric gene vectors has dramatically improved their biological properties, including enhanced biocompatibility, prolonged circulation time, and increased bio-distribution. However, PEG grafting of PEI for subsequent condensation of nucleic acids (NAs) does not necessarily result in the formation of a PEI/NAs core with a PEG corona. But often times, the presence of PEG interferes with PEI's electrostatic interaction with NAs. We describe here a facile method to prepare multilayered biodegradable micelles which address some of the critical drawbacks associated with current PEI-based systems. The polyplex micelles have superb stability and stealth properties. Moreover, we describe a method to prepare fully biodegradable and biocompatible injectable hydrogels for use in localized gene therapy.

  19. Optical absorption of dilute nitride alloys using self-consistent Green’s function method

    PubMed Central

    2014-01-01

    We have calculated the optical absorption for InGaNAs and GaNSb using the band anticrossing (BAC) model and a self-consistent Green’s function (SCGF) method. In the BAC model, we include the interaction of isolated and pair N levels with the host matrix conduction and valence bands. In the SCGF approach, we include a full distribution of N states, with non-parabolic conduction and light-hole bands, and parabolic heavy-hole and spin-split-off bands. The comparison with experiments shows that the first model accounts for many features of the absorption spectrum in InGaNAs; including the full distribution of N states improves this agreement. Our calculated absorption spectra for GaNSb alloys predict the band edges correctly but show more features than are seen experimentally. This suggests the presence of more disorder in GaNSb alloys in comparison with InGaNAs. PMID:24475947

  20. Synthetic Polymer Hybridization with DNA and RNA Directs Nanoparticle Loading, Silencing Delivery, and Aptamer Function

    PubMed Central

    Zhou, Zhun; Xia, Xin; Bong, Dennis

    2015-01-01

    We report herein discrete triplex hybridization of DNA and RNA with polyacrylates. Length-monodisperse triazine-derivatized polymers were prepared on gram-scale by reversible addition–fragmentation chain-transfer polymerization. Despite stereoregio backbone heterogeneity, the triazine polymers bind T/U-rich DNA or RNA with nanomolar affinity upon mixing in a 1:1 ratio, as judged by thermal melts, circular dichroism, gel-shift assays, and fluorescence quenching. We call these polyacrylates “bifacial polymer nucleic acids” (bPoNAs). Nucleic acid hybridization with bPoNA enables DNA loading onto polymer nanoparticles, siRNA silencing delivery, and can further serve as an allosteric trigger of RNA aptamer function. Thus, bPoNAs can serve as tools for both non-covalent bioconjugation and structure–function nucleation. It is anticipated that bPoNAs will have utility in both bio- and nanotechnology. PMID:26138550