Science.gov

Sample records for dual space analysis

  1. A Three-Level Analysis of Collaborative Learning in Dual-Interaction Spaces

    ERIC Educational Resources Information Center

    Lonchamp, Jacques

    2009-01-01

    CSCL systems which follow the dual-interaction spaces paradigm support the synchronous construction and discussion of shared artifacts by distributed or colocated small groups of learners. The most recent generic dual-interaction space environments, either model based or component based, can be deeply customized by teachers for supporting…

  2. Assessment of international payload requirements on the dual keel space station - A systems analysis capabilities example

    NASA Technical Reports Server (NTRS)

    Allen, C. L.; Andersen, G. C.

    1986-01-01

    In the early stages of spacecraft conceptual design, an investigation of subsystem requirements and their impacts on the total system provides insight into many aspects of the spacecraft design. Such an analysis has been performed on the dual keel space station to examine the system effects contributed by three international payloads provided by the Canadian, Japanese, and European Space Agencies. This example is used to illustrate some capabilities of available computer-driven tools and methods for a system analysis. Two space station configurations were examined, one without international payloads (the baseline configuration for the study) and one with the three international payloads. Each configuration was evaluated to define viewing limitations, rigid body dynamics and controls, structural dynamics, orbit lifetime, environmental control and life support, and thermal management effects. The performance, based on each subsystem evaluation, was then compared for the two configurations, and the results and recommendations are presented.

  3. Dual Space Technology Transfer

    NASA Astrophysics Data System (ADS)

    Kowbel, W.; Loutfy, R.

    2009-03-01

    Over the past fifteen years, MER has had several NASA SBIR Phase II programs in the area of space technology, based upon carbon-carbon (C-C) composites. In addition, in November 2004, leading edges supplied by MER provided the enabling technology to reach a Mach 10 record for an air breathing engine on the X-43 A flight. The MER business model constitutes a spin-off of technologies initially by incubating in house, and ultimately creating spin-off stand alone companies. FMC was formed to provide for technology transfer in the area of fabrication of C-C composites. FMC has acquired ISO 9000 and AS9100 quality certifications. FMC is fabricating under AS9100 certification, flight parts for several flight programs. In addition, FMC is expanding the application of carbon-carbon composites to several critical military programs. In addition to space technology transfer to critical military programs, FMC is becoming the world leader in the commercial area of low-cost C-C composites for furnace fixtures. Market penetrations have been accomplished in North America, Europe and Asia. Low-cost, quick turn-around and excellent quality of FMC products paves the way to greatly increased sales. In addition, FMC is actively pursuing a joint venture with a new partner, near closure, to become the leading supplier of high temperature carbon based composites. In addition, several other spin-off companies such as TMC, FiC, Li-Tech and NMIC were formed by MER with a plethora of potential space applications.

  4. Quantum dynamics in dual spaces

    SciTech Connect

    Sudarshan, E.C.G.

    1993-12-31

    Quantum mechanics gives us information about spectra of dynamical variables and transition rates including scattering cross sections. They can be exhibited as spectral information in analytically continued spaces and their duals. Quantum mechanics formulated in these generalized spaces is used to study scattering and time evolution. It is shown that the usual asymptotic condition is inadequate to deal with scattering of composite or unstable particles. Scattering theory needs amendment when the interacting system is not isospectral with the free Hamiltonian, and the amendment is formulated. Perturbation theory in generalized spaces is developed and used to study the deletion and augmentation of the spectrum of the Hamiltonian. A complete set of algebraically independent constants for an interacting system is obtained. The question of the breaking of time symmetry is discussed.

  5. Temperature-Dependent Pore Space of Sea Ice: X-ray Computed-Tomography and Dual Model Network Analysis

    NASA Astrophysics Data System (ADS)

    Pringle, D.; Miner, J.; Glantz, R.; Hilpert, M.; Eicken, H.

    2006-12-01

    Sea ice provides a mechanical and thermal barrier between the atmosphere and ocean at high latitudes and is an important component of the climate system. It is a composite material with temperature- and salinity- dependent volume fractions of ice, brine and air. Our present interest is the microstructural control of the (hydraulic) permeability, which affects the melt-season albedo (shortwave reflectance) of sea ice by enabling or restricting the drainage of surface meltwater, and is also relevant for other processes including nutrient delivery to microorganisms colonizing the lower layers of the ice sheet. At low temperatures, the relative brine volume (porosity) is small, the inclusions are disconnected, and the permeability is small. The relative brine volume increases with temperature, and the permeability increases strongly above a porosity of ~5%. We have imaged the pore space of natural and laboratory-grown sea ice with x-ray micro-computed tomography (CT) over a temperature range typical of that in the Arctic ( - 25°C to -3°C) and which spans corresponding changes in the permeability by several orders of magnitude. Based on our `Dual Model' approach, we identify pore bodies and throats from the segmented CT data to eventually derive a pore network. We characterize the temperature-dependence of the pore space connectivity and apply critical path analysis to investigate the dependence of permeability on pore microstructural evolution.

  6. Dual Vector Spaces and Physical Singularities

    NASA Astrophysics Data System (ADS)

    Rowlands, Peter

    Though we often refer to 3-D vector space as constructed from points, there is no mechanism from within its definition for doing this. In particular, space, on its own, cannot accommodate the singularities that we call fundamental particles. This requires a commutative combination of space as we know it with another 3-D vector space, which is dual to the first (in a physical sense). The combination of the two spaces generates a nilpotent quantum mechanics/quantum field theory, which incorporates exact supersymmetry and ultimately removes the anomalies due to self-interaction. Among the many natural consequences of the dual space formalism are half-integral spin for fermions, zitterbewegung, Berry phase and a zero norm Berwald-Moor metric for fermionic states.

  7. Analysis of Genotoxic and Cytotoxic Responses Induced by Simulated Space Radiation Qualities by Use of Recombinant Bacteria Carrying a Dual-Function Dual-Reporter Construct

    NASA Astrophysics Data System (ADS)

    Baumstark-Khan, Christa; Hellweg, Christine; Zahoor, Ahmed; Testard, Isabelle; Reitz, Guenther

    Along with the long-term space exploration come various potential health risks due to unique physical factors of the space environment. Space radiation is one of the primary environmental hazards associated with space flight. In order to deal with space-related risk radiation exposure must be properly characterised and quantified, and biological effects of charged particles have to be analysed in ground based research, especially as astronauts are subjected to a differing radiation quality in space than they receive on Earth. For risk assessment, the mutagenic potential of the heavy ion component of the galactic cosmic radiation is of major concern for tumour induction as radiation late effects. The recombinant SWITCH test is based on TA1535 Salmonella typhimurium cells transformed with a dual-function dual-reporter vector harbouring (a) the genes for bioluminescence production from Photobacterium leiognathi under the control of a DNA-damage inducible promoter and (b) the gene for green fluorescent protein from the jellyfish Aequorea victoria under the control of a constitutive promoter. Suchlike genetically modified organism report on the presence of genotoxic conditions by dose dependent increase of bioluminescence induction and on the presence of cytotoxic conditions by dose dependent decrease in GFP fluorescence. By this, it is possible to analyse bacterial inactivation and mutation induction by ionizing radiation in parallel in the same cell within short time. Experiments with heavy ions have been performed with the SWITCH test at GANIL with the following accelerated heavy ions: 35 MeV/u (72 keV/µm) and 75 MeV/u (37 keV/µm) carbon, 95 MeV/u argon (377 keV/µm), 95 MeV/u neon (98 keV/µm), 75 MeV/u nickel (967 keV/µm) and 29 MeV/u lead (10238 keV/µm). The results obtained clearly show that the numbers of hits (particles per cm2 ) necessary to inactivate the bacteria (cytotoxicity) depend on LET. The higher the ionisation capacity of the accelerated ion, the

  8. Tight dual models of pore spaces

    NASA Astrophysics Data System (ADS)

    Glantz, Roland; Hilpert, Markus

    2008-05-01

    The pore throats in a porous medium control permeability, drainage, and straining through their pore scale geometry and through the way they are connected via pore bodies on the macroscale. Likewise, imbibition is controlled through the geometry of the pore bodies (pore scale) and through the way the pore bodies are connected via pore throats on the macroscale. In an effort to account for both scales at the same time we recently introduced an image-based model for pore spaces that consists of two parts related by duality: (1) a decomposition of a polyhedral pore space into polyhedral pore bodies separated by polygonal pore throats and (2) a polygonal pore network that is homotopy equivalent to the pore space. In this paper we stick to the dual concept while amending the definition of the pore throats and, as a consequence, the other elements of the dual model. Formerly, the pore throats consisted of single two-dimensional Delaunay cells, while they now usually consist of more than one two-dimensional Delaunay cell and extend all the way into the narrowing ends of the pore channel cross sections. This is the first reason for naming the amended dual model "tight". The second reason is that the formation of the pore throats is now guided by an objective function that always attains its global optimum (tight optimization). At the end of the paper we report on simulations of drainage performed on tight dual models derived from simulated sphere packings and 3D gray-level images. The C-code for the generation of the tight dual model and the simulation of drainage is publicly available at https://jshare.johnshopkins.edu/mhilper1/public_html/tdm.html.

  9. Dual spaces of differential Lie algebras

    SciTech Connect

    Kupershmidt, B.A.

    1982-01-01

    We present a mathematical scheme which serves as an infinite-dimensional generalization of Poisson structures on dual spaces of finite-dimensional Lie algebras, which are well known and widely used in classical mechanics. These structures have recently appeared in the theory of Lax equations, long waves in hydrodynamics, and various other physical models: compressible hydrodynamics, magnetohydrodynamics, multifluid plasmas, elasticity, superfluid /sup 4/He and /sup 3/He-A, Ginzburg-Landau theory of superconductors, and classical chromohydrodynamics (the generalization of plasma physics to Yang-Mills interactions).

  10. Dual-Pulse Pulse Position Modulation (DPPM) for Deep-Space Optical Communications: Performance and Practicality Analysis

    NASA Technical Reports Server (NTRS)

    Li, Jing; Hylton, Alan; Budinger, James; Nappier, Jennifer; Downey, Joseph; Raible, Daniel

    2012-01-01

    Due to its simplicity and robustness against wavefront distortion, pulse position modulation (PPM) with photon counting detector has been seriously considered for long-haul optical wireless systems. This paper evaluates the dual-pulse case and compares it with the conventional single-pulse case. Analytical expressions for symbol error rate and bit error rate are first derived and numerically evaluated, for the strong, negative-exponential turbulent atmosphere; and bandwidth efficiency and throughput are subsequently assessed. It is shown that, under a set of practical constraints including pulse width and pulse repetition frequency (PRF), dual-pulse PPM enables a better channel utilization and hence a higher throughput than it single-pulse counterpart. This result is new and different from the previous idealistic studies that showed multi-pulse PPM provided no essential information-theoretic gains than single-pulse PPM.

  11. Dual-Use system architecture for a space situational awareness system in Japan

    NASA Astrophysics Data System (ADS)

    Otani, Y.; Kohtake, N.; Ohkami, Y.

    The use of outer space plays a vital role in both defense and civil fields. Since the separation of space activities between civil and defense applications is extremely inefficient, the Dual-Use concept has been considered fundamental for promoting the effective use of space. To the best of the authors' knowledge, most previous studies on Dual-Use focused on the technological aspects, and very few on a system engineering approach to Dual-Use. This left some important issues untouched such as the operational aspects of a system of systems, which need to be understood in a more generic context. This paper presents the results of a conceptual study, system design and management analysis of Dual-Use system architecture. First, an outline of the Dual-Use concept will be described and a definition of Dual-Use given. The effectiveness of applying the Dual-Use system concept to Space Situational Awareness (SSA) for both defense and civil users as a system of systems will then be discussed and investigated with a stakeholders analysis, context diagram and design structure matrix method. It has demonstrated that there is a need for a Dual-Use SSA Data Center which works as a binder between defense and civil systems as well as a data policy for constructing a Dual-Use SSA system.

  12. Dual keel space station control/structures interaction study

    NASA Technical Reports Server (NTRS)

    Young, John W.; Lallman, Frederick J.; Cooper, Paul A.

    1987-01-01

    A study was made to determine the influence of truss bay size on the performance of the space station control system. The objective was to determine if any control problems existed during reboost and to assess the level of potential control/structures interaction during operation of the control moment gyros used for vertical stabilization. The models analyzed were detailed finite-element representations of the 5 meter and 9 foot growth versions of the 300 kW dual keel station. Results are presented comparing the performance of the reboost control system for both versions of the space station. Standards for comparison include flexible effects at the attitude control sensor locations and flexible contributions to pointing error at the solar collectors. Bode analysis results are presented for the attitude control system and control, structural, and damping sensitivities are examined.

  13. Anthropomorphic dual-arm space telemanipulation system

    NASA Technical Reports Server (NTRS)

    Jau, Bruno M.

    1990-01-01

    Dexterous dual-arm manipulations are feasible with the system described and illustrated in the paper. The structure is based on an extensible host arm that carries the dual-arm robot which comprises two 7-DOF arms each of which includes a hand with a thumb and three fingers with 4 DOF each. Joint compliance can be stiffened to any level, and the operator uses arm harnesses and gloves to utilize the robotics in an anthropomorphic fashion. The configuration eliminates coordinate-transformation computations, and the system is found to achieve a control-frequency rate of 1000 Hz for its direct man/machine interfaces based on fiber-optic cables. The electronics control for the system utilizes a sensory system consisting of force, position, and compliance sensors. The robotics system is expected to be a user-friendly device that permits assembly, repair, tethering, and other complex mechanical operations.

  14. Dual throat thruster cold flow analysis

    NASA Technical Reports Server (NTRS)

    Lundgreen, R. B.; Nickerson, G. R.; Obrien, C. J.

    1978-01-01

    The concept was evaluated with cold flow (nitrogen gas) testing and through analysis for application as a tripropellant engine for single-stage-to-orbit type missions. Three modes of operation were tested and analyzed: (1) Mode 1 Series Burn, (2) Mode 1 Parallel Burn, and (3) Mode 2. Primary emphasis was placed on the Mode 2 plume attachment aerodynamics and performance. The conclusions from the test data analysis are as follows: (1) the concept is aerodynamically feasible, (2) the performance loss is as low as 0.5 percent, (3) the loss is minimized by an optimum nozzle spacing corresponding to an AF-ATS ratio of about 1.5 or an Le/Rtp ratio of 3.0 for the dual throat hardware tested, requiring only 4% bleed flow, (4) the Mode 1 and Mode 2 geometry requirements are compatible and pose no significant design problems.

  15. Dual Use Space Technology Transfer Conference Paper

    NASA Technical Reports Server (NTRS)

    Orndoff, Evelyne

    1994-01-01

    New textile fibers have been developed or modified to meet the complex and constraining criteria of space applications. The most common of these criteria are light weight, nonflammability or flame retardancy, and high strength and durability in both deep space environment and the oxygen enriched crew bay area of the spacecraft. The fibers which successfully pass the tests of flammability and toxicity, and display the desired mechanical properties are selected for space applications. Such advanced fibers developed for the Crew and Thermal Systems Division (CTSD) at the Johnson Space Center include 'Beta' fiber, heat stabilized polybenzimidazole and polyimide, as well as modified aramid Durette(TM), multi-fibrous Ortho(TM) fabric, and flame resistant cotton. The physical, mechanical, and chemical properties of these fibers are briefly discussed. The testing capabilities in the CTSD laboratory to ascertain some of the properties of these and other fibrous materials are also discussed. Most of these materials developed for spacecraft, space suit, and flight equipment applications have found other commercial applications. These advanced textile fibers are used mostly for aircraft, transportation, public buildings, hospitals, and protective clothing applications.

  16. Dual Accelerometer Usage Strategy for Onboard Space Navigation

    NASA Technical Reports Server (NTRS)

    Zanetti, Renato; D'Souza, Chris

    2012-01-01

    This work introduces a dual accelerometer usage strategy for onboard space navigation. In the proposed algorithm the accelerometer is used to propagate the state when its value exceeds a threshold and it is used to estimate its errors otherwise. Numerical examples and comparison to other accelerometer usage schemes are presented to validate the proposed approach.

  17. Design of a large dual polarized Ku band reflectarray for space borne radar altimeter

    NASA Technical Reports Server (NTRS)

    Hodges, Richard E.; Zawadzki, Mark

    2004-01-01

    We describe the design of a large dual-beam, dual polarized reflectarray designed for a space-based radar altimeter. This application requires a 2.16 X 0.35 m aperture that can be folded for launch stowage. Low mass and >50% efficiency are also required. A reflectarray antenna offers the best approach but also presents unique technical challenges since a reflectarry has never been used in a space based radar application. In what follows, we describe the design, analysis and measurements of a breadboard test array built to demonstrate the reflectarray concept.

  18. Control strategy for a dual-arm maneuverable space robot

    NASA Technical Reports Server (NTRS)

    Wang, P. K. C.

    1987-01-01

    A simple strategy for the attitude control and arm coordination of a maneuverable space robot with dual arms is proposed. The basic task for the robot consists of the placement of marked rigid solid objects with specified pairs of gripping points and a specified direction of approach for gripping. The strategy consists of three phases each of which involves only elementary rotational and translational collision-free maneuvers of the robot body. Control laws for these elementary maneuvers are derived by using a body-referenced dynamic model of the dual-arm robot.

  19. Dual structural-control optimization of large space structures

    NASA Technical Reports Server (NTRS)

    Messac, A.; Turner, J.

    1984-01-01

    A new approach is proposed for solving dual structural-control optimization problems for high-order flexible space structures where reduced-order structural models are employed. For a given initial structural dessign, a quadratic control cost is minimized subject to a constant-mass constraint. The sensitivity of the optimal control cost with respect to the stuctural design variables is then determined and used to obtain successive structural redesigns using a contrained gradient optimization algorithm. This process is repeated until the constrained control cost sensitivity becomes negligible. A numerical example is presented which demonstrates that this new approach effectively addresses the problem of dual optimization for potentially very high-order structures.

  20. Gauge theories on hyperbolic spaces and dual wormhole instabilities

    SciTech Connect

    Buchel, Alex

    2004-09-15

    We study supergravity duals of strongly coupled four-dimensional gauge theories formulated on compact quotients of hyperbolic spaces. The resulting background geometries are represented by Euclidean wormholes, which complicate establishing the precise gauge theory/string theory correspondence dictionary. These backgrounds suffer from the nonperturbative instabilities arising from the D3D3-bar pair-production in the background four-form potential. We discuss conditions for suppressing this Schwingerlike instability. We find that Euclidean wormholes arising in this construction develop a naked singularity before they can be stabilized.

  1. Future of dual-use space awareness technologies

    NASA Astrophysics Data System (ADS)

    Czyzak, Stanley R.

    2000-10-01

    The use of all classes of space systems, whether owned by defense, civil, commercial, scientific, allied or foreign organizations, is increasing rapidly. In turn, the surveillance of such systems and activities in space are of interest to all parties. Interests will only increase in time and with the new ways to exploit the space environment. However, the current space awareness infrastructure and capabilities are not maintaining pace with the demands and advanced technologies being brought online. The use of surveillance technologies, some of which will be discussed in the conference, will provide us the eventual capability to observe and assess the environment, satellite health and status, and the uses of assets on orbit. This provides us a space awareness that is critical to the military operator and to the commercial entrepreneur for their respective successes. Thus the term 'dual-use technologies' has become a reality. For this reason we will briefly examine the background, current, and future technology trends that can lead us to some insights for future products and services.

  2. Volumic omit maps in ab initio dual-space phasing.

    PubMed

    Oszlányi, Gábor; Sütő, András

    2016-07-01

    Alternating-projection-type dual-space algorithms have a clear construction, but are susceptible to stagnation and, thus, inefficient for solving the phase problem ab initio. To improve this behaviour new omit maps are introduced, which are real-space perturbations applied periodically during the iteration process. The omit maps are called volumic, because they delete some predetermined subvolume of the unit cell without searching for atomic regions or analysing the electron density in any other way. The basic algorithms of positivity, histogram matching and low-density elimination are tested by their solution statistics. It is concluded that, while all these algorithms based on weak constraints are practically useless in their pure forms, appropriate volumic omit maps can transform them to practically useful methods. In addition, the efficiency of the already useful reflector-type charge-flipping algorithm can be further improved. It is important that these results are obtained by using non-sharpened structure factors and without any weighting scheme or reciprocal-space perturbation. The mathematical background of volumic omit maps and their expected applications are also discussed. PMID:27357850

  3. Dual redshift on Planck-scale-curved momentum spaces

    NASA Astrophysics Data System (ADS)

    Amelino-Camelia, Giovanni; Barcaroli, Leonardo; Gubitosi, Giulia; Loret, Niccoló

    2013-12-01

    Several approaches to the investigation of the quantum-gravity problem have provided ‘theoretical evidence’ of a role for the Planck scale in characterizing the geometry of momentum space. One of the main obstructions for a full exploitation of this scenario is the understanding of the role of the Planck-scale-curved geometry of momentum space in the correlations between emission and detection times, the ‘travel times’ for a particle to go from a given emitter to a given detector. These travel times appear to receive Planck-scale corrections for which no standard interpretation is applicable, and the associated implications for spacetime locality gave rise to the notion of ‘relative locality’ which is still in the early stages of investigation. We here show that these Planck-scale corrections to travel times can be described as ‘dual redshift’ (or ‘lateshift’): they are manifestations of momentum-space curvature of the same type already known for ordinary redshift produced by spacetime curvature. In turn, we can identify the novel notion of ‘relative momentum-space locality’ as a known but under-appreciated feature associated with ordinary redshift produced by spacetime curvature, and this can be described in complete analogy with the relative spacetime locality that became of interest in the recent quantum-gravity literature. We also briefly comment on how these findings may be relevant for an approach to the quantum-gravity problem proposed by Max Born in 1938 and centered on Born duality.

  4. Free-floating dual-arm robots for space assembly

    NASA Technical Reports Server (NTRS)

    Agrawal, Sunil Kumar; Chen, M. Y.

    1994-01-01

    Freely moving systems in space conserve linear and angular momentum. As moving systems collide, the velocities get altered due to transfer of momentum. The development of strategies for assembly in a free-floating work environment requires a good understanding of primitives such as self motion of the robot, propulsion of the robot due to onboard thrusters, docking of the robot, retrieval of an object from a collection of objects, and release of an object in an object pool. The analytics of such assemblies involve not only kinematics and rigid body dynamics but also collision and impact dynamics of multibody systems. In an effort to understand such assemblies in zero gravity space environment, we are currently developing at Ohio University a free-floating assembly facility with a dual-arm planar robot equipped with thrusters, a free-floating material table, and a free-floating assembly table. The objective is to pick up workpieces from the material table and combine them into prespecified assemblies. This paper presents analytical models of assembly primitives and strategies for overall assembly. A computer simulation of an assembly is developed using the analytical models. The experiment facility will be used to verify the theoretical predictions.

  5. Design of a dual species atom interferometer for space

    NASA Astrophysics Data System (ADS)

    Schuldt, Thilo; Schubert, Christian; Krutzik, Markus; Bote, Lluis Gesa; Gaaloul, Naceur; Hartwig, Jonas; Ahlers, Holger; Herr, Waldemar; Posso-Trujillo, Katerine; Rudolph, Jan; Seidel, Stephan; Wendrich, Thijs; Ertmer, Wolfgang; Herrmann, Sven; Kubelka-Lange, André; Milke, Alexander; Rievers, Benny; Rocco, Emanuele; Hinton, Andrew; Bongs, Kai; Oswald, Markus; Franz, Matthias; Hauth, Matthias; Peters, Achim; Bawamia, Ahmad; Wicht, Andreas; Battelier, Baptiste; Bertoldi, Andrea; Bouyer, Philippe; Landragin, Arnaud; Massonnet, Didier; Lévèque, Thomas; Wenzlawski, Andre; Hellmig, Ortwin; Windpassinger, Patrick; Sengstock, Klaus; von Klitzing, Wolf; Chaloner, Chris; Summers, David; Ireland, Philip; Mateos, Ignacio; Sopuerta, Carlos F.; Sorrentino, Fiodor; Tino, Guglielmo M.; Williams, Michael; Trenkel, Christian; Gerardi, Domenico; Chwalla, Michael; Burkhardt, Johannes; Johann, Ulrich; Heske, Astrid; Wille, Eric; Gehler, Martin; Cacciapuoti, Luigi; Gürlebeck, Norman; Braxmaier, Claus; Rasel, Ernst

    2015-06-01

    Atom interferometers have a multitude of proposed applications in space including precise measurements of the Earth's gravitational field, in navigation & ranging, and in fundamental physics such as tests of the weak equivalence principle (WEP) and gravitational wave detection. While atom interferometers are realized routinely in ground-based laboratories, current efforts aim at the development of a space compatible design optimized with respect to dimensions, weight, power consumption, mechanical robustness and radiation hardness. In this paper, we present a design of a high-sensitivity differential dual species 85Rb/87Rb atom interferometer for space, including physics package, laser system, electronics and software. The physics package comprises the atom source consisting of dispensers and a 2D magneto-optical trap (MOT), the science chamber with a 3D-MOT, a magnetic trap based on an atom chip and an optical dipole trap (ODT) used for Bose-Einstein condensate (BEC) creation and interferometry, the detection unit, the vacuum system for 10-11 mbar ultra-high vacuum generation, and the high-suppression factor magnetic shielding as well as the thermal control system. The laser system is based on a hybrid approach using fiber-based telecom components and high-power laser diode technology and includes all laser sources for 2D-MOT, 3D-MOT, ODT, interferometry and detection. Manipulation and switching of the laser beams is carried out on an optical bench using Zerodur bonding technology. The instrument consists of 9 units with an overall mass of 221 kg, an average power consumption of 608 W (814 W peak), and a volume of 470 liters which would well fit on a satellite to be launched with a Soyuz rocket, as system studies have shown.

  6. Dual-Use Space Technology Transfer Conference and Exhibition. Volume 2

    NASA Technical Reports Server (NTRS)

    Krishen, Kumar (Compiler)

    1994-01-01

    This is the second volume of papers presented at the Dual-Use Space Technology Transfer Conference and Exhibition held at the Johnson Space Center February 1-3, 1994. Possible technology transfers covered during the conference were in the areas of information access; innovative microwave and optical applications; materials and structures; marketing and barriers; intelligent systems; human factors and habitation; communications and data systems; business process and technology transfer; software engineering; biotechnology and advanced bioinstrumentation; communications signal processing and analysis; medical care; applications derived from control center data systems; human performance evaluation; technology transfer methods; mathematics, modeling, and simulation; propulsion; software analysis and decision tools; systems/processes in human support technology; networks, control centers, and distributed systems; power; rapid development; perception and vision technologies; integrated vehicle health management; automation technologies; advanced avionics; and robotics technologies.

  7. Dual-Use Space Technology Transfer Conference and Exhibition. Volume 1

    NASA Technical Reports Server (NTRS)

    Krishen, Kumar (Compiler)

    1994-01-01

    This document contains papers presented at the Dual-Use Space Technology Transfer Conference and Exhibition held at the Johnson Space Center February 1-3, 1994. Possible technology transfers covered during the conference were in the areas of information access; innovative microwave and optical applications; materials and structures; marketing and barriers; intelligent systems; human factors and habitation; communications and data systems; business process and technology transfer; software engineering; biotechnology and advanced bioinstrumentation; communications signal processing and analysis; new ways of doing business; medical care; applications derived from control center data systems; human performance evaluation; technology transfer methods; mathematics, modeling, and simulation; propulsion; software analysis and decision tools systems/processes in human support technology; networks, control centers, and distributed systems; power; rapid development perception and vision technologies; integrated vehicle health management; automation technologies; advanced avionics; ans robotics technologies. More than 77 papers, 20 presentations, and 20 exhibits covering various disciplines were presented b experts from NASA, universities, and industry.

  8. Dual nozzle aerodynamic and cooling analysis study

    NASA Technical Reports Server (NTRS)

    Meagher, G. M.

    1981-01-01

    Analytical models to predict performance and operating characteristics of dual nozzle concepts were developed and improved. Aerodynamic models are available to define flow characteristics and bleed requirements for both the dual throat and dual expander concepts. Advanced analytical techniques were utilized to provide quantitative estimates of the bleed flow, boundary layer, and shock effects within dual nozzle engines. Thermal analyses were performed to define cooling requirements for baseline configurations, and special studies of unique dual nozzle cooling problems defined feasible means of achieving adequate cooling.

  9. Exploring Third Space in a Dual-Language Setting: Opportunities and Challenges

    ERIC Educational Resources Information Center

    Fitts, Shanan

    2009-01-01

    This study examined the ways that 5th graders and their teachers constructed third spaces in bilingual and bicultural communities of practice in a dual-language school. Students and teachers used students' funds of knowledge to connect with and transform academic tasks and discourses and to create third spaces. In transformational third spaces,…

  10. Space station commonality analysis

    NASA Technical Reports Server (NTRS)

    1988-01-01

    This study was conducted on the basis of a modification to Contract NAS8-36413, Space Station Commonality Analysis, which was initiated in December, 1987 and completed in July, 1988. The objective was to investigate the commonality aspects of subsystems and mission support hardware while technology experiments are accommodated on board the Space Station in the mid-to-late 1990s. Two types of mission are considered: (1) Advanced solar arrays and their storage; and (2) Satellite servicing. The point of departure for definition of the technology development missions was a set of missions described in the Space Station Mission Requirements Data Base. (MRDB): TDMX 2151 Solar Array/Energy Storage Technology; TDMX 2561 Satellite Servicing and Refurbishment; TDMX 2562 Satellite Maintenance and Repair; TDMX 2563 Materials Resupply (to a free-flyer materials processing platform); TDMX 2564 Coatings Maintenance Technology; and TDMX 2565 Thermal Interface Technology. Issues to be addressed according to the Statement of Work included modularity of programs, data base analysis interactions, user interfaces, and commonality. The study was to consider State-of-the-art advances through the 1990s and to select an appropriate scale for the technology experiments, considering hardware commonality, user interfaces, and mission support requirements. The study was to develop evolutionary plans for the technology advancement missions.

  11. Mini-cavity plasma core reactors for dual-mode space nuclear power/propulsion systems. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Chow, S.

    1976-01-01

    A mini-cavity plasma core reactor is investigated for potential use in a dual-mode space power and propulsion system. In the propulsive mode, hydrogen propellant is injected radially inward through the reactor solid regions and into the cavity. The propellant is heated by both solid driver fuel elements surrounding the cavity and uranium plasma before it is exhausted out the nozzle. The propellant only removes a fraction of the driver power, the remainder is transferred by a coolant fluid to a power conversion system, which incorporates a radiator for heat rejection. Neutronic feasibility of dual mode operation and smaller reactor sizes than those previously investigated are shown to be possible. A heat transfer analysis of one such reactor shows that the dual-mode concept is applicable when power generation mode thermal power levels are within the same order of magnitude as direct thrust mode thermal power levels.

  12. Optimal Spacing of Dual-axis Trackers for Concentrating Photovoltaic Systems

    NASA Astrophysics Data System (ADS)

    Kim, Yong Sin; Winston, Roland

    2011-12-01

    The levelized cost of energy (LCOE) is widely used to compare the cost of energy generation across technologies. In a utility-scale concentrating photovoltaic (CPV) system, the spacing of dual-axis trackers must be balanced with total energy harvested from modules to minimize LCOE. In this paper, a spacing method of dual-axis trackers in a CPV system is presented. Based on the definition of LCOE, a cost function is defined and optimized in terms of spacing related parameters. Various methods to estimate hourly direct normal irradiance (DNI) are investigated and m-by-n tracker array configurations to minimize the cost function are discussed.

  13. Self-dual solutions of Yang-Mills theory on Euclidean AdS space

    SciTech Connect

    Sarioglu, Oezguer; Tekin, Bayram

    2009-05-15

    We find nontrivial, time-dependent solutions of the (anti) self-dual Yang-Mills equations in the four-dimensional Euclidean anti-de Sitter space. In contrast to the Euclidean flat space, the action depends on the moduli parameters and the charge can take any noninteger value.

  14. Dual-pump Kerr Micro-cavity Optical Frequency Comb with varying FSR spacing.

    PubMed

    Wang, Weiqiang; Chu, Sai T; Little, Brent E; Pasquazi, Alessia; Wang, Yishan; Wang, Leiran; Zhang, Wenfu; Wang, Lei; Hu, Xiaohong; Wang, Guoxi; Hu, Hui; Su, Yulong; Li, Feitao; Liu, Yuanshan; Zhao, Wei

    2016-01-01

    In this paper, we demonstrate a novel dual-pump approach to generate robust optical frequency comb with varying free spectral range (FSR) spacing in a CMOS-compatible high-Q micro-ring resonator (MRR). The frequency spacing of the comb can be tuned by an integer number FSR of the MRR freely in our dual-pump scheme. The dual pumps are self-oscillated in the laser cavity loop and their wavelengths can be tuned flexibly by programming the tunable filter embedded in the cavity. By tuning the pump wavelength, broadband OFC with the bandwidth of >180 nm and the frequency-spacing varying from 6 to 46-fold FSRs is realized at a low pump power. This approach could find potential and practical applications in many areas, such as optical metrology, optical communication, and signal processing systems, for its excellent flexibility and robustness. PMID:27338250

  15. Dual-pump Kerr Micro-cavity Optical Frequency Comb with varying FSR spacing

    PubMed Central

    Wang, Weiqiang; Chu, Sai T.; Little, Brent E.; Pasquazi, Alessia; Wang, Yishan; Wang, Leiran; Zhang, Wenfu; Wang, Lei; Hu, Xiaohong; Wang, Guoxi; Hu, Hui; Su, Yulong; Li, Feitao; Liu, Yuanshan; Zhao, Wei

    2016-01-01

    In this paper, we demonstrate a novel dual-pump approach to generate robust optical frequency comb with varying free spectral range (FSR) spacing in a CMOS-compatible high-Q micro-ring resonator (MRR). The frequency spacing of the comb can be tuned by an integer number FSR of the MRR freely in our dual-pump scheme. The dual pumps are self-oscillated in the laser cavity loop and their wavelengths can be tuned flexibly by programming the tunable filter embedded in the cavity. By tuning the pump wavelength, broadband OFC with the bandwidth of >180 nm and the frequency-spacing varying from 6 to 46-fold FSRs is realized at a low pump power. This approach could find potential and practical applications in many areas, such as optical metrology, optical communication, and signal processing systems, for its excellent flexibility and robustness. PMID:27338250

  16. Accurate Analysis and Computer Aided Design of Microstrip Dual Mode Resonators and Filters.

    NASA Astrophysics Data System (ADS)

    Grounds, Preston Whitfield, III

    1995-01-01

    Microstrip structures are of interest due to their many applications in microwave circuit design. Their small size and ease of connection to both passive and active components make them well suited for use in systems where size and space is at a premium. These include satellite communication systems, radar systems, satellite navigation systems, cellular phones and many others. In general, space is always a premium for any mobile system. Microstrip resonators find particular application in oscillators and filters. In typical filters each microstrip patch corresponds to one resonator. However, when dual mode patches are employed, each patch acts as two resonators and therefore reduces the amount of space required to build the filter. This dissertation focuses on the accurate electromagnetic analysis of the components of planar dual mode filters. Highly accurate analyses are required so that the resonator to resonator coupling and the resonator to input/output can be predicted with precision. Hence, filters can be built with a minimum of design iterations and tuning. The analysis used herein is an integral equation formulation in the spectral domain. The analysis is done in the spectral domain since the Green's function can be derived in closed form, and the spatial domain convolution becomes a simple product. The resulting set of equations is solved using the Method of Moments with Galerkin's procedure. The electromagnetic analysis is applied to range of problems including unloaded dual mode patches, dual mode patches coupled to microstrip feedlines, and complete filter structures. At each step calculated results are compared to measured results and good agreement is found. The calculated results are also compared to results from the circuit analysis program HP EESOF^{ rm TM} and again good agreement is found. A dual mode elliptic filter is built and good performance is obtained.

  17. Compact dual channel optical fiber amplifier for space communication applications

    NASA Astrophysics Data System (ADS)

    Stevens, G.; Henwood-Moroney, L.; Hosking, P.; Kehayas, E.; Stampoulidis, L.; Robertson, A.

    2015-03-01

    We present results from the development of a dual channel Optical Fiber Amplifier (OFA) that consists of two copropagating low noise EDFAs at 1565 and 1545nm. The two channels have separate outputs but can also be combined via an optical switch to a common output channel for an increased output signal power. The OFA produces up to 35dB gain at low signal input powers and a total of over 350mW optical signal power combined from both EDFA channels with a 5mW signal input. The OFA was tested with input signals between 0.1 - 20 mW over the C-band and with pump power varying from 0 - 100% of the maximum operating pump power. The OFA module has total mass of 583 g including all electrical and optical components, as well as optical and electrical bulkheads, and a total module volume of 430 cm3. The module was also radiation tested via gamma irradiation up to 100 krad TID, validating the robustness of the optical amplifier against RIA effects and its suitability for LEO and GEO satellite missions.

  18. Analysis of space network loading

    NASA Technical Reports Server (NTRS)

    Simons, Mark; Larrson, Gus

    1994-01-01

    The NASA Space Network (SN) consists of several geosynchronous communications satellites, in addition to ground support facilities. Space Network management must predict years in advance what network resources are necessary to adequately satisfy all SN users. Similarly, users of the Space Network must know throughout all stages of mission planning and operations to what extent their communication support requirements can be met. NASA, at the Goddard Space Flight Center, performs Space Network and Mission Modeling using The Network Planning and Analysis System (NPAS), to determine the answers to these questions.

  19. Dual Solutions for Nonlinear Flow Using Lie Group Analysis

    PubMed Central

    Awais, Muhammad; Hayat, Tasawar; Irum, Sania; Saleem, Salman

    2015-01-01

    `The aim of this analysis is to investigate the existence of the dual solutions for magnetohydrodynamic (MHD) flow of an upper-convected Maxwell (UCM) fluid over a porous shrinking wall. We have employed the Lie group analysis for the simplification of the nonlinear differential system and computed the absolute invariants explicitly. An efficient numerical technique namely the shooting method has been employed for the constructions of solutions. Dual solutions are computed for velocity profile of an upper-convected Maxwell (UCM) fluid flow. Plots reflecting the impact of dual solutions for the variations of Deborah number, Hartman number, wall mass transfer are presented and analyzed. Streamlines are also plotted for the wall mass transfer effects when suction and blowing situations are considered. PMID:26575996

  20. Quantitative dual-probe microdialysis: mathematical model and analysis.

    PubMed

    Chen, Kevin C; Höistad, Malin; Kehr, Jan; Fuxe, Kjell; Nicholson, Charles

    2002-04-01

    Steady-state microdialysis is a widely used technique to monitor the concentration changes and distributions of substances in tissues. To obtain more information about brain tissue properties from microdialysis, a dual-probe approach was applied to infuse and sample the radiotracer, [3H]mannitol, simultaneously both in agar gel and in the rat striatum. Because the molecules released by one probe and collected by the other must diffuse through the interstitial space, the concentration profile exhibits dynamic behavior that permits the assessment of the diffusion characteristics in the brain extracellular space and the clearance characteristics. In this paper a mathematical model for dual-probe microdialysis was developed to study brain interstitial diffusion and clearance processes. Theoretical expressions for the spatial distribution of the infused tracer in the brain extracellular space and the temporal concentration at the probe outlet were derived. A fitting program was developed using the simplex algorithm, which finds local minima of the standard deviations between experiments and theory by adjusting the relevant parameters. The theoretical curves accurately fitted the experimental data and generated realistic diffusion parameters, implying that the mathematical model is capable of predicting the interstitial diffusion behavior of [3H]mannitol and that it will be a valuable quantitative tool in dual-probe microdialysis. PMID:12067242

  1. Dual-wavelength erbium-doped fiber laser with tunable wavelength spacing using a twin core fiber-based filter

    NASA Astrophysics Data System (ADS)

    Yin, Guolu; Lou, Shuqin; Wang, Xin; Han, Bolin

    2014-05-01

    A dual-wavelength erbium-doped fiber laser with tunable wavelength spacing was proposed and experimentally demonstrated by using a twin core fiber (TCF)-based filter. Benefiting from the polarization dependence of the TCF-based filter, the laser operated in dual-wavelength oscillation with two orthogonal polarization states. By adjusting the polarization controller, the wavelength spacing was tuned from 0.1 nm to 1.2 nm without shifting the centre position of the two wavelengths. By stretching the TCF, the two wavelengths were simultaneously tuned with fixed wavelength spacing. Such a dual-wavelength fiber laser could find applications in optical fiber sensors and microwave photonics generation.

  2. Space lab system analysis

    NASA Technical Reports Server (NTRS)

    Rives, T. B.; Ingels, F. M.

    1988-01-01

    An analysis of the Automated Booster Assembly Checkout System (ABACS) has been conducted. A computer simulation of the ETHERNET LAN has been written. The simulation allows one to investigate different structures of the ABACS system. The simulation code is in PASCAL and is VAX compatible.

  3. Dual-parameter radar rainfall measurement from space - A test result from an aircraft experiment

    NASA Technical Reports Server (NTRS)

    Kozu, Toshiaki; Nakamura, Kenji; Meneghini, Robert; Boncyk, Wayne C.

    1991-01-01

    An aircraft experiment has been conducted with a dual-frequency (X/Ka-bands) radar to test various rainfall retrieval methods from space. The authors test a method to derive raindrop size distribution (DSD) parameters from the combination of a radar reflectivity profile and a path-integrated attenuation derived from surface return, which may be available from most spaceborne radars. The estimated DSD parameters are reasonable in that the values generally fall within the range of commonly measured ones and that shifts in DSD parameters appear to be correlated with changes in storm type. The validity of the estimation result is also demonstrated by a consistency check using the Ka-band reflectivity profile which is independent of the DSD estimation process. Although errors may occur in the cases of nonuniform beam filling, these test results indicate the feasibility of the dual-parameter radar measurement from space in achieving a better accuracy in quantitative rainfall remote measurements.

  4. Multiverse Space-Antispace Dual Calabi-Yau `Exciplex-Zitterbewegung' Particle Creation

    NASA Astrophysics Data System (ADS)

    Amoroso, Richard L.

    Modeling the `creation/emergence' of matter from spacetime is as old as modern cosmology itself and not without controversy within each model such as Static, Steady-state, Big Bang or Multiverse Continuous-State. In this paper we present only a brief primitive introduction to a new form of `Exciplex-Zitterbewegung' dual space-antispace vacuum Particle Creation applicable especially to Big Bang alternatives which are well-known but ignored; Hubble discovered `Redshift' not a Doppler expansion of the universe which remains the currently popular interpretation. Holographic Anthropic Multiverse cosmology provides viable alternatives to all seemingly sacrosanct pillars of the Big Bang. A model for Multiverse Space-Antispace Dual Calabi-Yau `Exciplex-Zitterbewegung' particle creation has only become possible by incorporating the additional degrees of freedom provided by the capacity complex dimensional extended Yang-Mills Kaluza-Klein correspondence provides.

  5. Image analysis in dual modality tomography for material classification

    NASA Astrophysics Data System (ADS)

    Basarab-Horwath, I.; Daniels, A. T.; Green, R. G.

    2001-08-01

    A dual modality tomographic system is described for material classification in a simulated multi-component flow regime. It combines two tomographic modalities, electrical current and light, to image the interrogated area. Derived image parameters did not allow material classification. PCA analysis was performed on this data set producing a new parameter set, which allowed material classification. This procedure reduces the dimensionality of the data set and also offers a pre-processing technique prior to analysis by another classifier.

  6. Space lab system analysis

    NASA Technical Reports Server (NTRS)

    Ingels, F. M.; Rives, T. B.

    1987-01-01

    An analytical analysis of the HOSC Generic Peripheral processing system was conducted. The results are summarized and they indicate that the maximum delay in performing screen change requests should be less than 2.5 sec., occurring for a slow VAX host to video screen I/O rate of 50 KBps. This delay is due to the average I/O rate from the video terminals to their host computer. Software structure of the main computers and the host computers will have greater impact on screen change or refresh response times. The HOSC data system model was updated by a newly coded PASCAL based simulation program which was installed on the HOSC VAX system. This model is described and documented. Suggestions are offered to fine tune the performance of the ETERNET interconnection network. Suggestions for using the Nutcracker by Excelan to trace itinerate packets which appear on the network from time to time were offered in discussions with the HOSC personnel. Several visits to the HOSC facility were to install and demonstrate the simulation model.

  7. Dual-arm supervisory and shared control space servicing task experiments

    NASA Technical Reports Server (NTRS)

    Backes, Paul G.

    1992-01-01

    A dual-arm task execution primitive has been implemented for cooperative dual-arm telerobotic task execution utilizing multiple sensors concurrently. The primitive has been integrated into a telerobot task execution system and can be called by a task planning system for execution of tasks requiring dual-arm sensor based motion, e.g., force control, teleoperation, and shared control. The primitive has a large input parameter set which is used to specify the desired behavior of the motion. Move-squeeze decomposition is utilized to decompose forces sensed at the wrists of the two manipulators into forces in the move subspace, which cause system motion, and forces in the squeeze subspaces, which cause internal forces. The move and squeeze forces are then separately controlled. Several space servicing tasks utilizing the cooperative dual-arm control capability are described, and experimental results from the tasks are given. The supervisory and shared control tasks include capture of a rotating satellite, orbital replacement unit changeout, fluid coupler seating and locking, and contour following.

  8. The space physics analysis network

    NASA Astrophysics Data System (ADS)

    Green, James L.

    1988-04-01

    The Space Physics Analysis Network, or SPAN, is emerging as a viable method for solving an immediate communication problem for space and Earth scientists and has been operational for nearly 7 years. SPAN and its extension into Europe, utilizes computer-to-computer communications allowing mail, binary and text file transfer, and remote logon capability to over 1000 space science computer systems. The network has been used to successfully transfer real-time data to remote researchers for rapid data analysis but its primary function is for non-real-time applications. One of the major advantages for using SPAN is its spacecraft mission independence. Space science researchers using SPAN are located in universities, industries and government institutions all across the United States and Europe. These researchers are in such fields as magnetospheric physics, astrophysics, ionosperic physics, atmospheric physics, climatology, meteorology, oceanography, planetary physics and solar physics. SPAN users have access to space and Earth science data bases, mission planning and information systems, and computational facilities for the purposes of facilitating correlative space data exchange, data analysis and space research. For example, the National Space Science Data Center (NSSDC), which manages the network, is providing facilities on SPAN such as the Network Information Center (SPAN NIC). SPAN has interconnections with several national and international networks such as HEPNET and TEXNET forming a transparent DECnet network. The combined total number of computers now reachable over these combined networks is about 2000. In addition, SPAN supports full function capabilities over the international public packet switched networks (e.g. TELENET) and has mail gateways to ARPANET, BITNET and JANET.

  9. The space-dependent model and output characteristics of intra-cavity pumped dual-wavelength lasers

    NASA Astrophysics Data System (ADS)

    He, Jin-Qi; Dong, Yuan; Zhang, Feng-Dong; Yu, Yong-Ji; Jin, Guang-Yong; Liu, Li-Da

    2016-01-01

    The intra-cavity pumping scheme which is used to simultaneously generate dual-wavelength lasers was proposed and published by us and the space-independent model of quasi-three-level and four-level intra-cavity pumped dual-wavelength lasers was constructed based on this scheme. In this paper, to make the previous study more rigorous, the space-dependent model is adopted. As an example, the output characteristics of 946 nm and 1064 nm dual-wavelength lasers under the conditions of different output mirror transmittances are numerically simulated by using the derived formula and the results are nearly identical to what was previously reported.

  10. Closely spaced nanomagnets by dual e-beam exposure for low-energy nanomagnet logic

    SciTech Connect

    Shah, Faisal A.; Csaba, Gyorgy; Butler, Katherine; Bernstein, Gary H.

    2013-05-07

    The effect of nanomagnet spacing on required clock field has been studied by micromagnetic simulation for supermalloy (Ni{sub 79}Fe{sub 16}Mo{sub 5}) dots with dimensions 90 Multiplication-Sign 60 Multiplication-Sign 20 nm{sup 3} and 120 Multiplication-Sign 60 Multiplication-Sign 20 nm{sup 3}. Reduction of the inter-magnet spacing for both dimensions has resulted in reduction of the required clock field in the simulation. A dual e-beam exposure technique has been developed to allow fabrication of ultra dense features using conventional poly(methylmethacrylate) e-beam resist. Nanomagnet logic (NML) datalines of supermalloy dots with {approx}10 nm and {approx}15 nm spacing have been fabricated using dual e-beam exposure with a 3{sigma} overlay accuracy of {approx}4 nm. Fabricated NML datalines have been characterized using magnetic force microscopy for various clock fields. Datalines of both spacing have shown proper NML functionality with a clock field as low as 60 mT.

  11. Kennedy Space Center Spaceport Analysis

    NASA Technical Reports Server (NTRS)

    Wary, Samantha A.

    2013-01-01

    Until the Shuttle Atlantis' final landing on July 21, 2011, Kennedy Space Center (KSC) served as NASA's main spaceport, which is a launch and landing facility for rockets and spacecraft that are attempting to enter orbit. Many of the facilities at KSC were created to assist the Shuttle Program. One of the most important and used facilities is the Shuttle Landing Facility (SLF), This was the main landing area for the return of the shuttle after her mission in space. · However, the SLF has also been used for a number of other projects including straight-line testing by Gibbs Racing, weather data collection by NOAA, and an airfield for the KSC helicopters. This runway is three miles long with control tower at midfield and a fire department located at the end in care of an emergency. This facility, which was part of the great space race, will continue to be used for historical events as Kennedy begins to commercialize its facilities. KSC continues to be an important spaceport to the government, and it will transform into an important spaceport for the commercial industry as well. During my internship at KSC's Center Planning and Development Directorate, I had the opportunity to be a part of the negotiation team working on the agreement for Space Florida to control the Shuttle Landing Facility. This gave me the opportunity to learn about all the changes that are occurring here at Kennedy Space Center. Through various meetings, I discovered the Master Plan and its focus is to transform the existing facilities that were primarily used for the Shuttle Program, to support government operations and commercial flights in the future. This. idea is also in a new strategic business plan and completion of a space industry market analysis. All of these different documentations were brought to my attention and I. saw how they came together in the discussions of transitioning the SLF to a commercial operator, Space Florida. After attending meetings and partaking in discussions for

  12. Control/structures interaction study of two 300 KW dual-keel space station concepts

    NASA Technical Reports Server (NTRS)

    Young, J. W.; Lallman, F. J.; Cooper, P. A.; Giesy, D. P.

    1986-01-01

    The results of an investigation of the influence of structural stiffness of the space station framework on the controllability of two 300 kw class, solar dynamic powered, dual-keel space station designs are presented. The two design concepts differed only in the truss bay dimensions of the structural framework of the stations. Two control studies were made: (1) A study of the interaction of the framework structural response with the reaction control system used for attitude control during an orbital reboost maneuver; and (2) A study of the stability of the space station attitude control system with sensors influenced by the elastic deformations of the station framework. Although both configurations had acceptable control characteristics, the configuration with the larger truss bay dimension and its increased structural stiffness had more attractive characteristics for pointing control of the solar dynamic system during reboost and for attitude control during normal in-orbit operations.

  13. Attitude motion of a dual-spin space station supported with magnetic bearings

    NASA Astrophysics Data System (ADS)

    Nakajima, Atsushi; Ishii, Kazuhito

    A large manned space station is proposed which provides artificial gravity and microgravity environments simultaneously in separate sections. This space station is composed of a nonrotating microgravity section at the center, a rotating artificial gravity section, and a transit cabin used for transportation between them. The first section has experiment modules and the second one has habitat modules at the end of the beamlike structure extended from the rotating center body. The two sections are connected by an electromagnetic suspension mechanism; mechanically, they are separated perfectly. Therefore, the acceleration disturbance to the microgravity section from the rotating section is reduced to the level that microgravity experiments can be conducted without any trouble. The purpose of this paper is to formulate the dynamical model of this dual-spin space station and to obtain the linearized equations of motion. Computer simulations show that long-period nutational motion is attenuated by controlling the magnetic suspension system.

  14. Space elevator systems level analysis

    SciTech Connect

    Laubscher, B. E.

    2004-01-01

    The Space Elevator (SE) represents a major paradigm shift in space access. It involves new, untried technologies in most of its subsystems. Thus the successful construction of the SE requires a significant amount of development, This in turn implies a high level of risk for the SE. This paper will present a systems level analysis of the SE by subdividing its components into their subsystems to determine their level of technological maturity. such a high-risk endeavor is to follow a disciplined approach to the challenges. A systems level analysis informs this process and is the guide to where resources should be applied in the development processes. It is an efficient path that, if followed, minimizes the overall risk of the system's development. systems level analysis is that the overall system is divided naturally into its subsystems, and those subsystems are further subdivided as appropriate for the analysis. By dealing with the complex system in layers, the parameter space of decisions is kept manageable. Moreover, A rational way to manage One key aspect of a resources are not expended capriciously; rather, resources are put toward the biggest challenges and most promising solutions. This overall graded approach is a proven road to success. The analysis includes topics such as nanotube technology, deployment scenario, power beaming technology, ground-based hardware and operations, ribbon maintenance and repair and climber technology.

  15. Dual discounting in cost-benefit analysis for environmental impacts

    SciTech Connect

    Kula, Erhun; Evans, David

    2011-04-15

    Discounting has been a long-established intertemporal efficiency tool in cost-benefit analysis which focuses on project selection at communal level with a view to maximising the social welfare. However, with the relentless growth in environmental stress that, in good parts, stems from investment projects the established criterion in discounting appears to be inadequate especially when environmental issues are taken into consideration. This paper looks at how dual focus on efficiency and sustainability can be achieved by using dual discounting, i.e. discounting environmental benefits separately and differently from other costs and benefits and applies this alternative criterion to an afforestation scheme in the United Kingdom which contains carbon sequestration in addition to timber benefits.

  16. Mechanisms and physiological impact of the dual localization of mitochondrial intermembrane space proteins.

    PubMed

    Petrungaro, Carmelina; Riemer, Jan

    2014-08-01

    Eukaryotic cells developed diverse mechanisms to guide proteins to more than one destination within the cell. Recently, the proteome of the IMS (intermembrane space) of mitochondria of yeast cells was identified showing that approximately 20% of all soluble IMS proteins are dually localized to the IMS, as well as to other cellular compartments. Half of these dually localized proteins are important for oxidative stress defence and the other half are involved in energy homoeostasis. In the present review, we discuss the mechanisms leading to the dual localization of IMS proteins and the implications for mitochondrial function. PMID:25109985

  17. 10 kWe dual-mode space nuclear power system for military and scientific applications

    NASA Astrophysics Data System (ADS)

    Malloy, John; Westerman, Kurt; Rochow, Richard; Scoles, Stephen

    The Small Externally-fueled Heat Pipe Thermionic Reactor concept is used as the basis of a 10 kWe dual-mode space power system scheme that generates both arcjet propulsion system power and direct (hydrogen propellant-heating) thrust. This direct-thrust feature allows the nuclear-power system to move a payload from LEO to GEO in less than one month, using half as much propellant as a cryogenic-fuel chemical rocket. The nuclear reactor uses 36 thermionic heat-pipe modules, which produce electricity within the reactor and remove waste heat.

  18. Anyonic Strings and Membranes in Anti-de Sitter Space and Dual Aharonov-Bohm Effects

    SciTech Connect

    Hartnoll, Sean A.

    2007-03-16

    It is observed that strings in AdS{sub 5}xS{sup 5} and membranes in AdS{sub 7}xS{sup 4} exhibit long range phase interactions. Two well separated membranes dragged around one another in anti-de Sitter space (AdS) acquire phases of 2{pi}/N. The same phases are acquired by a well separated F and D string dragged around one another. The phases are shown to correspond to both the standard and a novel type of Aharonov-Bohm effect in the dual field theory.

  19. A Dual-Chamber Hybrid Inflatable Suitlock (DCIS) for Planetary Surfaces or Deep Space

    NASA Technical Reports Server (NTRS)

    Howe, A. Scott; Kennedy, Kriss; Guirgis, Peggy; Boyle, Robert

    2011-01-01

    The Habitat Demonstration Unit (HDU) Project in conjunction with the NASA Extravehicular Activity (EVA) team has identified a need for a hybrid inflatable and hard shell suitlock that can be used for planetary surface and deep space human exploration missions. Through ongoing analog studies at NASA Desert Research and Technologies Studies (D-RATS) and in NASA's Prototyping Testbed Facility, it has been determined that a compactly stowed, deployable suitlock unit is needed to accommodate advanced EVA egress and ingress operations for various environments with only minor modification.The Dual-Chamber Inflatable Suitlock (DCIS) consists of three hard in-line bulkheads, separating two cylindrical membrane-walled compartments. A dual-compartment suitlock will allow for dust and contaminant control, suit maintenance, and efficient egress / ingress; and the inflatable aspect of the design will allow the unit to stow in a compact package for transport. This paper describes the DCIS functionality, subsystems, and operational scenarios.The novel concepts included in the DCIS are the triple bulkhead, dual-chamber that has one compartment that is continuously pressurized (either at cabin pressure, or may be used for transitional pressure from high-pressure habitats), and a nominal unpressurized second compartment where the suits will be kept for normal operations. The advantages include quicker egress / ingress, capacity for 'shirt sleeve' suit maintenance, and portability of the entire unit.

  20. On Study of Air/Space-borne Dual-Wavelength Radar for Estimates of Rain Profiles

    NASA Technical Reports Server (NTRS)

    Liao, Liang; Meneghini, Robert

    2004-01-01

    In this study, a framework is discussed to apply air/space-borne dual-wavelength radar for the estimation of characteristic parameters of hydrometeors. The focus of our study is on the Global Precipitation Measurements (GPM) precipitation radar, a dual-wavelength radar that operates at Ku (13.8 GHz) and Ka (35 GHz) bands. As the droplet size distributions (DSD) of rain are expressed as the Gamma function, a procedure is described to derive the median volume diameter (D(sub 0)) and particle number concentration (N(sub T)) of rain. The correspondences of an important quantity of dual-wavelength radar, defined as deferential frequency ratio (DFR), to the D(sub 0) in the melting region are given as a function of the distance from the 0 C isotherm. A self-consistent iterative algorithm that shows a promising to account for rain attenuation of radar and infer the DSD without use of surface reference technique (SRT) is examined by applying it to the apparent radar reflectivity profiles simulated from the DSD model and then comparing the estimates with the model (true) results. For light to moderate rain the self-consistent rain profiling approach converges to unique and correct solutions only if the same shape factors of Gamma functions are used both to generate and retrieve the rain profiles, but does not converges to the true solutions if the DSD form is not chosen correctly. To further examine the dual-wavelength techniques, the self-consistent algorithm, along with forward and backward rain profiling algorithms, is then applied to the measurements taken from the 2nd generation Precipitation Radar (PR-2) built by Jet Propulsion Laboratory. It is found that rain profiles estimated from the forward and backward approaches are not sensitive to shape factor of DSD Gamma distribution, but the self-consistent method is.

  1. Space shuttle natural environment analysis

    NASA Technical Reports Server (NTRS)

    Batts, Wade

    1988-01-01

    Five major tasks are briefly outlined: development of detailed wind profile measurements for Kennedy Space Center (KSC) and Vandenberg Air Force Base (VAFB): development of software to construct meteorological data tapes for use in the STS Post Ascent Analysis; development of storage, access, and utilization codes for Global Cloud Cover data; development of software and meteorological data bases to establish launch delay risks at KSC and VAFB; and development of the meteorological tower 301 climatological data base at VAFB.

  2. Visualization of dual-arm robot motion space under kinematic constraints

    SciTech Connect

    Tarn, T.J. ); De, P.K. ); Bejczy, A.K. ); Li, Z. )

    1995-02-01

    This article presents a technique for determining and visualizing the geometric motion capabilities of dual-arm robotic systems when the arms work on an object in a closed kinematic chain configuration, taking account of robot arms' base placements, object dimensions, object holding and contact constraints, and space occupancy conflicts of the two arms' links. The constrained and object orientation restricted motion space in general can be visualized as a complex 3D object with hidden unreachable holes or cavities of varying shapes. An automated visualization methodology is presented together with its graphical implementation, illustrated by an example. The methodology is an inverse computer vision technique in the sense that it creates rather than recognizes visual forms. 18 refs., 5 figs.

  3. Comments on dual-mode nuclear space power and propulsion system concepts

    NASA Technical Reports Server (NTRS)

    Layton, J. Preston; Grey, Jerry

    1991-01-01

    Some form of Dual-Mode Nuclear Space Power & Propulsion System (D-MNSP&PS) will be essential to spacefaring throughout teh solar system and that such systems must evolve as mankind moves into outer space. The initial D-MNPSP&PS Reference System should be based on (1) present (1990), and (2) advanced (1995) technology for use on comparable mission in the 2000 and 2005 time period respectively. D-MNSP&PS can be broken down into a number of subsystems: Nuclear subsystems including the energy source and controls for the release of thermal power at elevated temperatures; power conversion subsystems; waste heat rejection subsystems; and control and safety subsystems. These systems are briefly detailed.

  4. Space station functional relationships analysis

    NASA Technical Reports Server (NTRS)

    Tullis, Thomas S.; Bied, Barbra R.

    1988-01-01

    A systems engineering process is developed to assist Space Station designers to understand the underlying operational system of the facility so that it can be physically arranged and configured to support crew productivity. The study analyzes the operational system proposed for the Space Station in terms of mission functions, crew activities, and functional relationships in order to develop a quantitative model for evaluation of interior layouts, configuration, and traffic analysis for any Station configuration. Development of the model involved identification of crew functions, required support equipment, criteria of assessing functional relationships, and tools for analyzing functional relationship matrices, as well as analyses of crew transition frequency, sequential dependencies, support equipment requirements, potential for noise interference, need for privacy, and overall compatability of functions. The model can be used for analyzing crew functions for the Initial Operating Capability of the Station and for detecting relationships among these functions. Note: This process (FRA) was used during Phase B design studies to test optional layouts of the Space Station habitat module. The process is now being automated as a computer model for use in layout testing of the Space Station laboratory modules during Phase C.

  5. Lyndon B. Johnson Space Center (JSC) proposed dual-use technology investment program in intelligent robots

    NASA Technical Reports Server (NTRS)

    Erikson, Jon D.

    1994-01-01

    This paper presents an overview of the proposed Lyndon B. Johnson Space Center (JSC) precompetitive, dual-use technology investment project in robotics. New robotic technology in advanced robots, which can recognize and respond to their environments and to spoken human supervision so as to perform a variety of combined mobility and manipulation tasks in various sectors, is an obejective of this work. In the U.S. economy, such robots offer the benefits of improved global competitiveness in a critical industrial sector; improved productivity by the end users of these robots; a growing robotics industry that produces jobs and profits; lower cost health care delivery with quality improvements; and, as these 'intelligent' robots become acceptable throughout society, an increase in the standard of living for everyone. In space, such robots will provide improved safety, reliability, and productivity as Space Station evolves, and will enable human space exploration (by human/robot teams). The proposed effort consists of partnerships between manufacturers, universities, and JSC to develop working production prototypes of these robots by leveraging current development by both sides. Currently targeted applications are in the manufacturing, health care, services, and construction sectors of the U.S. economy and in the inspection, servicing, maintenance, and repair aspects of space exploration. But the focus is on the generic software architecture and standardized interfaces for custom modules tailored for the various applications allowing end users to customize a robot as PC users customize PC's. Production prototypes would be completed in 5 years under this proposal.

  6. Lyndon B. Johnson Space Center (JSC) proposed dual-use technology investment program in intelligent robotics

    NASA Technical Reports Server (NTRS)

    Erickson, Jon D.

    1994-01-01

    This paper presents an overview of the proposed Lyndon B. Johnson Space Center (JSC) precompetitive, dual-use technology investment project in robotics. New robotic technology in advanced robots, which can recognize and respond to their environments and to spoken human supervision so as to perform a variety of combined mobility and manipulation tasks in various sectors, is an objective of this work. In the U.S. economy, such robots offer the benefits of improved global competitiveness in a critical industrial sector; improved productivity by the end users of these robots; a growing robotics industry that produces jobs and profits; lower cost health care delivery with quality improvements; and, as these 'intelligent' robots become acceptable throughout society, an increase in the standard of living for everyone. In space, such robots will provide improved safety, reliability, and productivity as Space Station evolves, and will enable human space exploration (by human/robot teams). The proposed effort consists of partnerships between manufacturers, universities, and JSC to develop working production prototypes of these robots by leveraging current development by both sides. Currently targeted applications are in the manufacturing, health care, services, and construction sectors of the U.S. economy and in the inspection, servicing, maintenance, and repair aspects of space exploration. But the focus is on the generic software architecture and standardized interfaces for custom modules tailored for the various applications allowing end users to customize a robot as PC users customize PC's. Production prototypes would be completed in 5 years under this proposal.

  7. Dual Heat Pulse, Dual Layer Thermal Protection System Sizing Analysis and Trade Studies for Human Mars Entry Descent and Landing

    NASA Technical Reports Server (NTRS)

    McGuire, Mary Kathleen

    2011-01-01

    NASA has been recently updating design reference missions for the human exploration of Mars and evaluating the technology investments required to do so. The first of these started in January 2007 and developed the Mars Design Reference Architecture 5.0 (DRA5). As part of DRA5, Thermal Protection System (TPS) sizing analysis was performed on a mid L/D rigid aeroshell undergoing a dual heat pulse (aerocapture and atmospheric entry) trajectory. The DRA5 TPS subteam determined that using traditional monolithic ablator systems would be mass expensive. They proposed a new dual-layer TPS concept utilizing an ablator atop a low thermal conductivity insulative substrate to address the issue. Using existing thermal response models for an ablator and insulative tile, preliminary hand analysis of the dual layer concept at a few key heating points indicated that the concept showed potential to reduce TPS masses and warranted further study. In FY09, the followon Entry, Descent and Landing Systems Analysis (EDL-SA) project continued by focusing on Exploration-class cargo or crewed missions requiring 10 to 50 metric tons of landed payload. The TPS subteam advanced the preliminary dual-layer TPS analysis by developing a new process and updated TPS sizing code to rapidly evaluate mass-optimized, full body sizing for a dual layer TPS that is capable of dual heat pulse performance. This paper describes the process and presents the results of the EDL-SA FY09 dual-layer TPS analyses on the rigid mid L/D aeroshell. Additionally, several trade studies were conducted with the sizing code to evaluate the impact of various design factors, assumptions and margins.

  8. Primal and Dual Integrated Force Methods Used for Stochastic Analysis

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.

    2005-01-01

    At the NASA Glenn Research Center, the primal and dual integrated force methods are being extended for the stochastic analysis of structures. The stochastic simulation can be used to quantify the consequence of scatter in stress and displacement response because of a specified variation in input parameters such as load (mechanical, thermal, and support settling loads), material properties (strength, modulus, density, etc.), and sizing design variables (depth, thickness, etc.). All the parameters are modeled as random variables with given probability distributions, means, and covariances. The stochastic response is formulated through a quadratic perturbation theory, and it is verified through a Monte Carlo simulation.

  9. Space Flight Plasma Data Analysis

    NASA Technical Reports Server (NTRS)

    Wright, Kenneth H.; Minow, Joseph I.

    2009-01-01

    This slide presentation reviews a method to analyze the plasma data that is reported on board the International Space station (ISS). The Floating Potential Measurement Unit (FPMU), the role of which is to obtain floating potential and ionosphere plasma measurements for validation of the ISS charging model, assess photo voltaic array variability and interpreting IRI predictions, is composed of four probes: Floating Potential Probe (FPP), Wide-sweep Langmuir Probe (WLP), Narrow-sweep Langmuir Probe (NLP) and the Plasma Impedance Probe (PIP). This gives redundant measurements of each parameter. There are also many 'boxes' that the data must pass through before being captured by the ground station, which leads to telemetry noise. Methods of analysis for the various signals from the different sets are reviewed. There is also a brief discussion of LP analysis of Low Earth Orbit plasma simulation source.

  10. Characterization of dual-polarization LTE radio over a free-space optical turbulence channel.

    PubMed

    Bohata, J; Zvanovec, S; Korinek, T; Mansour Abadi, M; Ghassemlooy, Z

    2015-08-10

    A dual polarization (DP) radio over a free-space optical (FSO) communication link using a long-term evolution (LTE) radio signal is proposed and analyzed under different turbulence channel conditions. Radio signal transmission over the DP FSO channel is experimentally verified by means of error vector magnitude (EVM) statistics. We demonstrate that such a system, employing a 64 quadrature amplitude modulation at the frequency bands of 800 MHz and 2.6 GHz, evinces reliability with <8% of EVM in a turbulent channel. Based on the results, we show that transmitting the LTE signal over the FSO channel is a potential solution for last-mile access or backbone networks, when using multiple-input multiple-output based DP signals. PMID:26368379

  11. Ballistic limit regression analysis for Space Station Freedom meteoroid and space debris protection system

    NASA Astrophysics Data System (ADS)

    Jolly, William H.

    1992-05-01

    Relationships defining the ballistic limit of Space Station Freedom's (SSF) dual wall protection systems have been determined. These functions were regressed from empirical data found in Marshall Space Flight Center's (MSFC) Hypervelocity Impact Testing Summary (HITS) for the velocity range between three and seven kilometers per second. A stepwise linear least squares regression was used to determine the coefficients of several expressions that define a ballistic limit surface. Using statistical significance indicators and graphical comparisons to other limit curves, a final set of expressions is recommended for potential use in Probability of No Critical Flaw (PNCF) calculations for Space Station. The three equations listed below represent the mean curves for normal, 45 degree, and 65 degree obliquity ballistic limits, respectively, for a dual wall protection system consisting of a thin 6061-T6 aluminum bumper spaced 4.0 inches from a .125 inches thick 2219-T87 rear wall with multiple layer thermal insulation installed between the two walls. Normal obliquity is d(sub c) = 1.0514 v(exp 0.2983 t(sub 1)(exp 0.5228). Forty-five degree obliquity is d(sub c) = 0.8591 v(exp 0.0428) t(sub 1)(exp 0.2063). Sixty-five degree obliquity is d(sub c) = 0.2824 v(exp 0.1986) t(sub 1)(exp -0.3874). Plots of these curves are provided. A sensitivity study on the effects of using these new equations in the probability of no critical flaw analysis indicated a negligible increase in the performance of the dual wall protection system for SSF over the current baseline. The magnitude of the increase was 0.17 percent over 25 years on the MB-7 configuration run with the Bumper II program code.

  12. Ballistic limit regression analysis for Space Station Freedom meteoroid and space debris protection system

    NASA Technical Reports Server (NTRS)

    Jolly, William H.

    1992-01-01

    Relationships defining the ballistic limit of Space Station Freedom's (SSF) dual wall protection systems have been determined. These functions were regressed from empirical data found in Marshall Space Flight Center's (MSFC) Hypervelocity Impact Testing Summary (HITS) for the velocity range between three and seven kilometers per second. A stepwise linear least squares regression was used to determine the coefficients of several expressions that define a ballistic limit surface. Using statistical significance indicators and graphical comparisons to other limit curves, a final set of expressions is recommended for potential use in Probability of No Critical Flaw (PNCF) calculations for Space Station. The three equations listed below represent the mean curves for normal, 45 degree, and 65 degree obliquity ballistic limits, respectively, for a dual wall protection system consisting of a thin 6061-T6 aluminum bumper spaced 4.0 inches from a .125 inches thick 2219-T87 rear wall with multiple layer thermal insulation installed between the two walls. Normal obliquity is d(sub c) = 1.0514 v(exp 0.2983 t(sub 1)(exp 0.5228). Forty-five degree obliquity is d(sub c) = 0.8591 v(exp 0.0428) t(sub 1)(exp 0.2063). Sixty-five degree obliquity is d(sub c) = 0.2824 v(exp 0.1986) t(sub 1)(exp -0.3874). Plots of these curves are provided. A sensitivity study on the effects of using these new equations in the probability of no critical flaw analysis indicated a negligible increase in the performance of the dual wall protection system for SSF over the current baseline. The magnitude of the increase was 0.17 percent over 25 years on the MB-7 configuration run with the Bumper II program code.

  13. Nano-casted Metal Oxide Aerogels as Dual Purpose Structural Components for Space Exploration

    NASA Technical Reports Server (NTRS)

    Vassilaras, Plousia E.

    2004-01-01

    NASA missions and space exploration rely on strong, ultra lightweight materials. Such materials are needed for building up past and present space vehicles such as the Sojourner Rover (1997) or the two MERs (2003), but also for a number of components and/or systems including thermal insulators, Solar Sails, Rigid Aeroshells, and Ballutes. The purpose of my internship here at Glenn Research Center is to make dual purpose materials; materials that in addition to being lightweight have electronic, photophysical and magnetic properties and, therefore, act as electronic components and sensors as well as structural components. One type of ultra lightweight material of great interest is aerogels, which have densities ranging from 0.003 g/cc to 0.8 g/cc . However, aerogels are extremely fragile and, as a result, have limited practical applications. Recently, Glenn Research Center has developed a process of nano-casting polymers onto the inorganic network of silica-based aerogels increasing the strength 300 fold while only increasing the density 3 fold. By combining the process of nano-casting polymers with inorganic oxide networks other than silica, we are actively pursuing lightweight dual purpose materials. To date, thirty different inorganic oxide aerogels have been prepared using either standard sol-gel chemistry or a non-alkoxide method involving metal chloride precursors and an epoxide; epichlorohydrin, propylene oxide or trimethylene oxide, as proton scavengers. More importantly, preliminary investigations show that the residual surface hydroxyl groups on each of these inorganic oxide aerogels can be successfully crosslinked with urethane. In addition to characterizing physical and mechanical properties such as density, strength and flexibility, each of these metal oxide aerogels are being characterized for thermal and electronic conductivity and magnetic and optical properties.

  14. Simulation of springback and microstructural analysis of dual phase steels

    NASA Astrophysics Data System (ADS)

    Kalyan, T. Sri.; Wei, Xing; Mendiguren, Joseba; Rolfe, Bernard

    2013-12-01

    With increasing demand for weight reduction and better crashworthiness abilities in car development, advanced high strength Dual Phase (DP) steels have been progressively used when making automotive parts. The higher strength steels exhibit higher springback and lower dimensional accuracy after stamping. This has necessitated the use of simulation of each stamped component prior to production to estimate the part's dimensional accuracy. Understanding the micro-mechanical behaviour of AHSS sheet may provide more accuracy to stamping simulations. This work can be divided basically into two parts: first modelling a standard channel forming process; second modelling the micro-structure of the process. The standard top hat channel forming process, benchmark NUMISHEET'93, is used for investigating springback effect of WISCO Dual Phase steels. The second part of this work includes the finite element analysis of microstructures to understand the behaviour of the multi-phase steel at a more fundamental level. The outcomes of this work will help in the dimensional control of steels during manufacturing stage based on the material's microstructure.

  15. Scaling analysis of baseline dual-axis cervical accelerometry signals.

    PubMed

    Sejdić, Ervin; Steele, Catriona M; Chau, Tom

    2011-09-01

    Dual-axis cervical accelerometry is an emerging approach for the assessment of swallowing difficulties. However, the baseline signals, i.e., vibration signals with only quiet breathing or apnea but without swallowing, are not well understood. In particular, to comprehend the contaminant effects of head motion on cervical accelerometry, we need to study the scaling behavior of these baseline signals. Dual-axis accelerometry data were collected from 50 healthy adult participants under conditions of quiet breathing, apnea and selected head motions, all in the absence of swallowing. The denoised cervical vibrations were subjected to detrended fluctuation analysis with empirically determined first-order detrending. Strong persistence was identified in cervical vibration signals in both anterior-posterior (A-P) and superior-inferior (S-I) directions, under all the above experimental conditions. Vibrations in the A-P axes exhibited stronger correlations than those in the S-I axes, possibly as a result of axis-specific effects of vasomotion. In both axes, stronger correlations were found in the presence of head motion than without, suggesting that head movement significantly impacts baseline cervical accelerometry. No gender or age effects were found on statistical persistence of either vibration axes. Future developments of cervical accelerometry-based medical devices should actively mitigate the effects of head movement. PMID:20708292

  16. Performance analysis of charge plasma based dual electrode tunnel FET

    NASA Astrophysics Data System (ADS)

    Anand, Sunny; Intekhab Amin, S.; Sarin, R. K.

    2016-05-01

    This paper proposes the charge plasma based dual electrode doping-less tunnel FET (DEDLTFET). The paper compares the device performance of the conventional doping-less TFET (DLTFET) and doped TFET (DGTFET). DEDLTEFT gives the superior results with high ON state current (ION ∼ 0.56 mA/μm), ION/IOFF ratio ∼ 9.12 × 1013 and an average subthreshold swing (AV-SS ∼ 48 mV/dec). The variation of different device parameters such as channel length, gate oxide material, gate oxide thickness, silicon thickness, gate work function and temperature variation are done and compared with DLTFET and DGTFET. Through the extensive analysis it is found that DEDLTFET shows the better performance than the other two devices, which gives the indication for an excellent future in low power applications.

  17. Space Shuttle and Space Station Radio Frequency (RF) Exposure Analysis

    NASA Technical Reports Server (NTRS)

    Hwu, Shian U.; Loh, Yin-Chung; Sham, Catherine C.; Kroll, Quin D.

    2005-01-01

    This paper outlines the modeling techniques and important parameters to define a rigorous but practical procedure that can verify the compliance of RF exposure to the NASA standards for astronauts and electronic equipment. The electromagnetic modeling techniques are applied to analyze RF exposure in Space Shuttle and Space Station environments with reasonable computing time and resources. The modeling techniques are capable of taking into account the field interactions with Space Shuttle and Space Station structures. The obtained results illustrate the multipath effects due to the presence of the space vehicle structures. It's necessary to include the field interactions with the space vehicle in the analysis for an accurate assessment of the RF exposure. Based on the obtained results, the RF keep out zones are identified for appropriate operational scenarios, flight rules and necessary RF transmitter constraints to ensure a safe operating environment and mission success.

  18. Hybrid state-space self-tuning control using dual-rate sampling

    NASA Technical Reports Server (NTRS)

    Shieh, Leang S.; Zhao, Xiao M.; Sunkel, John W.

    1991-01-01

    This paper presents a hybrid state-space self-tuning control scheme using dual-rate sampling for suboptimal digital adaptive control of linear time-invariant continuous-time multivariable stochastic systems with unknown parameters. An equivalent fast-rate discrete-time state-space innovation model (with estimated states) of the continuous-time system is constructed by using the estimated system parameters and Kalman gain. To utilize the existing optimal regional-pole assignment method developed in the continuous-time domain, the constructed fast-rate discrete-time model is converted into an equivalent continuous-time model for the development of a state-feedback optimal control law with pole placement in a specific region. The developed analog optimal control law is then converted into an equivalent pseudo-slow-rate digital control law via the proposed digital redesign technique, which can be realized via slow-rate digital electronics. The proposed method enables the development of a digitally implementable advanced control algorithm for digital adaptive control of continuous-time multivariable stochastic systems which may be unstable and/or have nonminimum phase.

  19. Analysis of mode switching algorithms in dual chamber pacemakers.

    PubMed

    Israel, Carsten W

    2002-03-01

    Dual chamber systems are currently implanted in an increasing number of patients with a pacing indication and paroxysmal atrial tachyarrhythmias (ATAs). To avoid tracking of high atrial rates during ATA while providing AV synchronous pacing during sinus rhythm and AV block, automatic mode switching (MS) to a nontracking mode has been developed. Several concepts of MS algorithms have been introduced differing in sensitivity and specificity of ATA detection, delay between ATA onset and MS, pacing mode during MS, rapidity of MS termination upon detection of sinus rhythm, and special algorithms pertinent to MS. This review classifies and analyzes algorithms that are integrated into MS concepts and outlines considerations on optimal MS performance. Based on simulations and clinical studies, fast MS concepts avoiding high paced ventricular rates seem preferable but require special functions to avoid loss of AV synchrony by inappropriate MS. Similarly, fast return to tracking mode after ATA cessation seems preferable but requires algorithms to prevent mode oscillations. Sudden ventricular rate changes have to be avoided by rate smoothing functions, and an appropriate ventricular rate during nontracking mode has to be provided by rate responsive pacing. Programming of the device includes individual optimization of atrial sensitivity, atrial blanking times, and tachycardia detection rates. In addition, a high signal-to-noise ratio by careful atrial lead implantation, narrowly spaced bipolar atrial leads and a good sensing amplifier, together with special algorithms for atrial sensing adjustment improve the performance of MS algorithms. PMID:11990674

  20. TANK SPACE ALTERNATIVES ANALYSIS REPORT

    SciTech Connect

    TURNER DA; KIRCH NW; WASHENFELDER DJ; SCHAUS PS; WODRICH DD; WIEGMAN SA

    2010-04-27

    This report addresses the projected shortfall of double-shell tank (DST) space starting in 2018. Using a multi-variant methodology, a total of eight new-term options and 17 long-term options for recovering DST space were evaluated. These include 11 options that were previously evaluated in RPP-7702, Tank Space Options Report (Rev. 1). Based on the results of this evaluation, two near-term and three long-term options have been identified as being sufficient to overcome the shortfall of DST space projected to occur between 2018 and 2025.

  1. An Empirical Analysis of the Dual Labor Market Theory.

    ERIC Educational Resources Information Center

    Andrisani, Paul James

    This study focuses upon the process of labor market entry of male youth in the context of the dual labor market theory. Essentially, the dual market theory contends that a large body of workers is involuntarily confined to substandard jobs in a "secondary" labor market which is separated from the mainstream, or "primary" sector by impenetrable…

  2. Space Utilization Analysis, Fall 1995.

    ERIC Educational Resources Information Center

    Hamilton, John

    In an effort to inform space allocation decisions, Gainesville College (GC) in Georgia, undertook a project to analyze classroom usage for fall 1995 and make projections to the year 2000 based on annual enrollment increases of 3%. Factors potentially affecting the use of space were determined to include the following: (1) conversion to the…

  3. Analysis of microgravity space experiments Space Shuttle programmatic safety requirements

    NASA Technical Reports Server (NTRS)

    Terlep, Judith A.

    1996-01-01

    This report documents the results of an analysis of microgravity space experiments space shuttle programmatic safety requirements and recommends the creation of a Safety Compliance Data Package (SCDP) Template for both flight and ground processes. These templates detail the programmatic requirements necessary to produce a complete SCDP. The templates were developed from various NASA centers' requirement documents, previously written guidelines on safety data packages, and from personal experiences. The templates are included in the back as part of this report.

  4. Space Station ECLSS Integration Analysis

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Space Station Environmental Control and Life Support System (ECLSS) contract with NASA MSFC covered the time frame from 9 May 1985 to 31 Dec. 1992. The contract roughly covered the period of Space Station Freedom (SSF) development from early Phase B through Phase C/D Critical Design Review (CDR). During this time, McDonnell Douglas Aerospace-Huntsville (formerly McDonnell Douglas Space Systems Company) performed an analytical support role to MSFC for the development of analytical math models and engineering trade studies related to the design of the ECLSS for the SSF.

  5. A dual-mode disturbance-accommodating controller for the Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Addington, Stewart; Johnson, C. D.

    Cyclic thermal expansions and mechanical stiction effects in the Solar Arrays on the Hubble Space Telescope (HST) are triggering repeated occurrences of damped, relaxation-type flex-body vibrations of the solar arrays. Those solar array vibrations are, in turn, causing unwanted, oscillating disturbance torques on the HST main body, which cause unwanted deviations of the telescope from its specified pointing direction. In this paper we propose two strategies one can adopt in designing a telescope-pointing controller to cope with the aforementioned disturbances: (1) a `total isolation' (TI) control strategy whereby the HST controller torques are designed to adaptively counteract and cancel-out the persistent disturbing torques that are causing the unwanted telescope motions, and (2) an `array damping' (AD) control strategy whereby the HST controller torques are used to actively augment the natural dampening of the solar array vibrations and the attendant telescope motions, between triggerings of the stiction-related flex-body relaxation oscillations. Using the principles of Disturbance-Accommodating Control (DAC) Theory a dual-mode controller for a generic, planar-motion (single-axis) model of the HST is proposed. This controller incorporates both the TI and AD modes of disturbance-accommodation. Simulation studies of the closed-loop system using generic parameter values clearly indicate, qualitatively, the enhanced pointing-performance such a controller can achieve.

  6. Dual-mode disturbance-accommodating pointing controller for Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Addington, Stewart I.; Johnson, C. D.

    1995-03-01

    Cyclic thermal expansions and mechanical stiction effects in the solar arrays on the Hubble Space Telescope (HST) are triggering repeated occurrences of damped, relaxation-type flex-body vibrations of the solar arrays. Those solar array vibrations are, in turn, causing unwanted deviations of the telescope from its specified pointing direction. In this paper we propose two strategies one can adopt in designing a telescope-pointing controller to cope with the aforementioned disturbances: 1) a total isolation (TI) control strategy whereby the HST controller torques are designed to adaptively counteract and cancel out the persistent disturbing torques that are causing the unwanted telescope motions and 2) an array damping (AD) control strategy whereby the HST controller torques are used to actively augment the natural dampening of the solar array vibrations and the attendant telescope motions, between triggerings of the stiction-related flex-body relaxation oscillations. Using the principles of disturbance accommodation control theory, a dual-mode controller for a generic, planar-motion (single-axis) model of the HST is proposed. This controller incorporates both the TI and AD modes of disturbance accommodation. Simulation studies of the closed-loop system using generic parameter values clearly indicate, qualitatively, the enhanced pointing performance such a controller can achieve.

  7. Facet Theory, Smallest Space Analysis, and Factor Analysis.

    ERIC Educational Resources Information Center

    Guttman, Louis

    1982-01-01

    Mathematical and statistical relationships between factor analysis and smallest space analysis are discussed. As spatial analysis of correlation matrices, factor analysis is a special case of smallest space analysis. The two differ in six ways: Shepard diagram, dimensionality, correction for communality, similarity coefficients, regions versus…

  8. State-Space Formulation for Circuit Analysis

    ERIC Educational Resources Information Center

    Martinez-Marin, T.

    2010-01-01

    This paper presents a new state-space approach for temporal analysis of electrical circuits. The method systematically obtains the state-space formulation of nondegenerate linear networks without using concepts of topology. It employs nodal/mesh systematic analysis to reduce the number of undesired variables. This approach helps students to…

  9. Analysis of Space Tourism Constraints

    NASA Astrophysics Data System (ADS)

    Bonnal, Christophe

    2002-01-01

    Space tourism appears today as a new Eldorado in a relatively near future. Private operators are already proposing services for leisure trips in Low Earth Orbit, and some happy few even tested them. But are these exceptional events really marking the dawn of a new space age ? The constraints associated to the space tourism are severe : - the economical balance of space tourism is tricky; development costs of large manned - the technical definition of such large vehicles is challenging, mainly when considering - the physiological aptitude of passengers will have a major impact on the mission - the orbital environment will also lead to mission constraints on aspects such as radiation, However, these constraints never appear as show-stoppers and have to be dealt with pragmatically: - what are the recommendations one can make for future research in the field of space - which typical roadmap shall one consider to develop realistically this new market ? - what are the synergies with the conventional missions and with the existing infrastructure, - how can a phased development start soon ? The paper proposes hints aiming at improving the credibility of Space Tourism and describes the orientations to follow in order to solve the major hurdles found in such an exciting development.

  10. The Integrated Space Weather Analysis System

    NASA Astrophysics Data System (ADS)

    Maddox, M. M.; Mullinix, R. E.; Jain, P.; Berrios, D.; Hesse, M.; Rastaetter, L.; MacNeice, P. J.; Kuznetsova, M. M.; Taktakishvili, A.; Garneau, J. W.; Conti-Vock, J.

    2009-12-01

    The Integrated Space Weather Analysis System is a joint development project at NASA GSFC between the Space Weather Laboratory, Community Coordinated Modeling Center, Applied Engineering & Technology Directorate, and NASA HQ Office Of Chief Engineer. The iSWA system is a turnkey, web-based dissemination system for NASA-relevant space weather information that combines forecasts based on the most advanced space weather models with concurrent space environment information. A key design driver for the iSWA system is to generate and present vast amounts of space weather resources in an intuitive, user-configurable, and adaptable format - thus enabling users to respond to current and future space weather impacts as well as enabling post-imact analysis. This presentation will highlight several technical aspects of the iSWA system implementation including data collection methods, database design, customizable user interfaces, interactive system components, and innovative displays of quantitative information.

  11. Verification of the dual integral glow analysis dosimetry system

    NASA Astrophysics Data System (ADS)

    Wagner, Eric Christopher

    2000-10-01

    The Dual Integral Glow Analysis (DINGA) method is a unique approach to the determination of the low-LET dose deposited within a thermoluminescent personnel dosimeter. DINGA creates its estimate of the dose deposited by utilizing the integrals of a sub-section of the glow curves obtained from opposite sides of one or more thermoluminescent detectors (TLDs) and knowledge of the TLDs thermophysical parameters. The performance of DINGA is evaluated with computational simulations for a variety of heating methods and error tolerance is also examined by introducing errors into the inputs the DINGA code. It has been found that DINGA's dose estimates are off approximately, in the worst case, the same percentage as the input parameter was varied. Experimental measurements are performed using a hot-gas heating method for large personnel doses and a laser heating method for smaller personnel doses with LiF: Mg, Ti (TLD-100) dosimeters. The dosimeters are exposed to select radiation fields generated by either certified sources or fields characterized by certified equipment. The DINGA dosimetry system is found to correctly report shallow and deep dose well within the limits required for certification by the National Voluntary Accreditation Program. The worst performance quotient is 0.19, well below the strictest limit of 0.30.

  12. Highly stable and tunable narrow-spacing dual-wavelength ytterbium-doped fiber using a microfiber Mach-Zehnder interferometer

    NASA Astrophysics Data System (ADS)

    Ahmad, Harith; Salim, Muhammad A. M.; Azzuhri, Saaidal R.; Harun, Sulaiman W.

    2016-02-01

    We describe a successful demonstration of highly stable and narrowly spaced dual-wavelength output via an ytterbium-doped fiber laser. A microfiber-based Mach-Zehnder interferometer and a tunable bandpass filter were both placed into the laser ring cavity for the purpose of ensuring a stable and narrowly spaced dual-wavelength output. Experimental results comprised three sets of dual-wavelength lasing output with wavelength spacing of 0.06, 0.09, and 0.22 nm, respectively, and side-mode suppression ratio of ˜50 dBm. A subsequent stability test provided evidence that maximum power and wavelength fluctuation were less than 0.8 dB and 0.01 nm, respectively, and thus, the obtained output was considered to be highly stable in dual-wavelength operation. The proposed system offers advantages of flexibility in dual-wavelength laser generation in addition to excellent reliability.

  13. A pseudo-dual-Doppler analysis of cyclic tornadogenesis

    NASA Astrophysics Data System (ADS)

    Dowell, David Collin

    2000-06-01

    Several tornadic storms formed in the Texas Panhandle on 8 June 1995, the date of the last mission of VORTEX (Verification of the Origins of Rotation in Tornadoes EXperiment). The southernmost storm in this severe weather outbreak produced a family of at least five tornadoes near the town of McLean. Airborne Doppler radar scans of this storm by the ELDORA (ELectra DOppler RAdar) offer the most detailed look to date at a storm producing a family of tornadoes. The goals of this study were twofold. The first was to determine a pseudo-dual-Doppler wind synthesis method in Cartesian coordinates appropriate for the analysis of the ELDORA data. Unique aspects of this part of the study include a comparison of wind synthesis methods based on variational formulations and the use of a non-uniform moving reference frame for the syntheses. A dual-Doppler formulation in which the radial velocity and continuity equations are all satisfied as weak constraints (Gamache 1997, Shapiro and Mewes 1999) yields a more accurate wind field than traditional (and variational) methods in which the radial velocity equations are satisfied exactly. The second goal of this study was to diagnose both the cyclic process and the formation of individual tornadoes. The McLean storm produced three large tornadoes at 18 min intervals. The last of these then lasted much longer (over one hour) and was stronger than the previous tornadoes. New pre-tornadic vortices formed on the east side of the updraft by tilting of strong environmental low-level horizontal vorticity into the vertical and then stretching of the vertical vorticity within the updraft. The vortices did not mature at low levels until they migrated to the west side of the updraft. Indirect evidence indicates that both baroclinic generation of horizontal vorticity and the rear downdraft may have played roles in tornado formation at this stage. The tornadic potential of a storm appears-to be related to the relative strength of low-level storm

  14. Dynamics and adaptive control of a dual-arm space robot with closed-loop constraints and uncertain inertial parameters

    NASA Astrophysics Data System (ADS)

    Jia, Ying-Hong; Hu, Quan; Xu, Shi-Jie

    2014-02-01

    A dynamics-based adaptive control approach is proposed for a planar dual-arm space robot in the presence of closed-loop constraints and uncertain inertial parameters of the payload. The controller is capable of controlling the position and attitude of both the satellite base and the payload grasped by the manipulator end effectors. The equations of motion in reduced-order form for the constrained system are derived by incorporating the constraint equations in terms of accelerations into Kane's equations of the unconstrained system. Model analysis shows that the resulting equations perfectly meet the requirement of adaptive controller design. Consequently, by using an indirect approach, an adaptive control scheme is proposed to accomplish position/attitude trajectory tracking control with the uncertain parameters being estimated on-line. The actuator redundancy due to the closed-loop constraints is utilized to minimize a weighted norm of the joint torques. Global asymptotic stability is proven by using Lyapunov's method, and simulation results are also presented to demonstrate the effectiveness of the proposed approach. [Figure not available: see fulltext.

  15. Segmentation of medical images by feature tracing in a self-dual morphological scale-space

    NASA Astrophysics Data System (ADS)

    Metzler, Volker H.; Thies, Christian; Lehmann, Thomas M.

    2001-07-01

    The multiscale approach derives a segmentation from the evolution of appropriate signal-descriptive features in scale-space. Features that are stable for a wide range of scales are assumed to belong to visually sensible regions. To compensate the well-known drawbacks of linear scale- spaces, the shape-preserving properties of morphological scale-space filtering are utilized. The limiting duality of morphological filters is overcome by a selfdual morphological approach considering both light and dark structures in either the opening or the closing branch of the scale-space. Reconstructive opening/closing-filters enable the scale=analysis of 2D signals, since they are causal with respect to regional maxima/minima. This allows to identify important regions in scale=space via their extrema. Each extremum is assigned a region by a gradient watershed of the corresponding scale. Due to morphological filtering, the scale behavior of the regions is representable by a tree structure describing the spatial inter- and intra-scale relations among regions. The significance of a watershed region is automatically derived from its scale behavior by considering various attributes describing scale-dependent, morphological, and statistical properties of the region. The most significant regions from the segmentation of the image. The algorithm was verified for various medical image domains, such as cytological micrographs, bone x-rays, and cranial NMR slices.

  16. Bi-directional free space laser communication of gigabit ethernet telemetry data using dual atmospheric effect mitigation approach

    NASA Astrophysics Data System (ADS)

    Chan, Eric; Saint Clair, Jonathan

    2016-05-01

    This paper presents experimental demonstration of optical components applicable in free space laser communication systems for bi-directional transmission of Gigabit Ethernet (GBE) telemetry data and control messages using a dual atmospheric effect mitigation approach. The objective is to address the challenges for optical transmission of telemetry data. (1) Turbulence effects which cause optical beam scintillation, wander and breakup, all of which cause signal degradation at the receiver. (2) An optical signal in free space has a fading effect which is caused by communications terminal equipment`s in-ability to maintain perfect pointing along a line of sight due to vibrations/motions of the mobile platform.

  17. SIR phasing by combination of SOLVE/RESOLVE and dual-space fragment extension involving OASIS

    NASA Astrophysics Data System (ADS)

    He, Yao; Gu, Yuan-Xin; Lin, Zheng-Jiong; Zheng, Chao-De; Fan, Hai-Fu

    2007-10-01

    A new phasing procedure has been proposed for dealing with single isomorphous replacement (SIR) x-ray diffraction data. The procedure combines SOLVE/RESOLVE with the dual-space fragment extension involving OASIS. Two sets of SIR data at 0.28 nm resolution taken from the protein (R)-phycoerythrin (PDB code: 1LIA) were used in the test. For one of the two SIR data sets, a default run of SOLVE/RESOLVE based on the heavy-atom substructure found by SHLEXD led automatically to an interpretable electron density map. OASIS could not effectively improve the result. For the other set of SIR data, SOLVE/RESOLVE resulted in a fragmented model consisting of 454 of the total 668 residues, in which only 29 residues were docked into the sequence. Based on this model, 7 iteration cycles of OASIS-DM-RESOLVE (build only) yielded automatically a model of 547 residues with 133 residues docked into the sequence. The overall-averaged phase error decreased considerably and the quality of electron density map was improved significantly. Two more cycles of iterative OASIS-DM-RESOLVE were carried out, in which the output phases and figures of merit from DM were merged with that from the original run of SOLVE/RESOLVE before they were passed onto RESOLVE (build only). This led automatically to a model containing 452 residues with 173 docked into the sequence. The resultant electron density map is manually traceable. It is concluded that when results of SOLVE/RESOLVE are not sufficiently satisfactory, the combination of SOLVE/RESOLVE and OASIS-DM-RESOLVE (build only) may significantly improve them.

  18. Technology Roadmap for Dual-Mode Scramjet Propulsion to Support Space-Access Vision Vehicle Development

    NASA Technical Reports Server (NTRS)

    Cockrell, Charles E., Jr.; Auslender, Aaron H.; Guy, R. Wayne; McClinton, Charles R.; Welch, Sharon S.

    2002-01-01

    Third-generation reusable launch vehicle (RLV) systems are envisioned that utilize airbreathing and combined-cycle propulsion to take advantage of potential performance benefits over conventional rocket propulsion and address goals of reducing the cost and enhancing the safety of systems to reach earth orbit. The dual-mode scramjet (DMSJ) forms the core of combined-cycle or combination-cycle propulsion systems for single-stage-to-orbit (SSTO) vehicles and provides most of the orbital ascent energy. These concepts are also relevant to two-stage-to-orbit (TSTO) systems with an airbreathing first or second stage. Foundation technology investments in scramjet propulsion are driven by the goal to develop efficient Mach 3-15 concepts with sufficient performance and operability to meet operational system goals. A brief historical review of NASA scramjet development is presented along with a summary of current technology efforts and a proposed roadmap. The technology addresses hydrogen-fueled combustor development, hypervelocity scramjets, multi-speed flowpath performance and operability, propulsion-airframe integration, and analysis and diagnostic tools.

  19. Ethanol analysis from biological samples by dual rail robotic autosampler.

    PubMed

    Morris-Kukoski, Cynthia L; Jagerdeo, Eshwar; Schaff, Jason E; LeBeau, Marc A

    2007-05-01

    Detection, identification, and quantitation of ethanol and other low molecular weight volatile compounds in liquid matrices by headspace gas chromatography-flame ionization detection (HS-GC-FID) and headspace gas chromatography-mass spectrometry (HS-GC-MS) are becoming commonly used practices in forensic laboratories. Although it is one of the most frequently utilized procedures, sample preparation is usually done manually. Implementing the use of a dual-rail, programmable autosampler can minimize many of the manual steps in sample preparation. The autosampler is configured so that one rail is used for sample preparation and the other rail is used as a traditional autosampler for sample introduction into the gas chromatograph inlet. The sample preparation rail draws up and sequentially adds a saturated sodium chloride solution and internal standard (0.08%, w/v acetonitrile) to a headspace vial containing a biological sample, a calibrator, or a control. Then, the analytical rail moves the sample to the agitator for incubation, followed by sampling of the headspace for analysis. Using DB-624 capillary columns, the method was validated on a GC-FID and confirmed with a GC-MS. The analytes (ethanol, acetonitrile) and possible interferences (acetaldehyde, methanol, pentane, diethyl ether, acetone, isopropanol, methylene chloride, n-propanol, and isovaleraldehyde) were baseline resolved for both the GC-FID and GC-MS methods. This method demonstrated acceptable linearity from 0 to 1500 mg/dL. The lower limit of quantitation (LOQ) was determined to be 17 mg/dL and the limit of detection was 5 mg/dL. PMID:17223393

  20. Sample Analysis Code System for the Dual Channel Counter.

    Energy Science and Technology Software Center (ESTSC)

    1994-09-14

    Version 00 RADCOMPT automates gross alpha and gross beta sample analysis calculations and, in many cases, warns the technologist when a hazard level is being approached or when it has been exceeded. The RADCOMPT program is unique in that it corrects for crosstalk between channels, and in this way provides increased accuracy and efficiency. Even though it is designed explicitly for the analyses of air samples and wipe samples, it can also be used formore » other sample types. It is designed to be used with a dual channel counter (in which one channel is used for alpha detection and the other for beta detection), but may be used with two single channel counters employed for the same purpose. In addition, it provides an automated means for the execution of the following radiological sample analyses protocol: A. Calibration of the counting system B. Calculation of sample activity or air activity concentrations (with the activities of air activity concentrations at the top and bottom of the two-sided 95 percent confidence interval also specified). C. Determination of minimum sample counting times required for detection and/or quantification of specified alpha and beta activities or air activity concentrations. In addition, alternate counting times are determined for alternate activities such that the specified alpha and beta activities are at the top of the 95% confidence interval, increasing the confidence that the activities measured are below the specified limits. D. Calculation of the minimum detectable activities or air activity concentrations. E. Determination of air sample volumes required for detection and/or quantification of specified alpha and beta air activity concentrations. F. Calculation of long-lived activities or air activity concentrations based on radon daughter and thoron daughter decay. G. Calculation of employees DAC-Hours and estimated Committed Effective Dose Equivalent. H. Varying calibration constants (to coincide with possible adjustments to

  1. The Integrated Space Weather Analysis System

    NASA Astrophysics Data System (ADS)

    Maddox, M. M.; Hesse, M.; Kuznetsova, M.; Rastaetter, L.; MacNeice, P. J.; Jain, P.; Garneau, J. W.; Berrios, D. H.; Pulkinnen, A.; Rowland, D.

    2008-12-01

    Space weather affects virtually all of NASA's endeavors, from robotic missions to human exploration. Knowledge and prediction of space weather conditions is therefore essential to NASA operations. The diverse nature of currently available space environment measurements and modeling products, along with the lack of single-portal access, renders its practical use for space weather analysis and forecasting unfeasible. There exists a compelling need for accurate real-time forecasting of both large-scale and local space environments - and their probable impacts for missions. A vital design driver for any system that is created to solve this problem lies in the fact that information needs to be presented in a form that is useful and as such, must be both easily accessible and understandable. The Integrated Space Weather Analysis System is a joint development project at NASA GSFC between the Space Weather Laboratory, Community Coordinated Modeling Center, Applied Engineering & Technology Directorate, and NASA HQ Office Of Chief Engineer. The iSWA system will be a turnkey, web-based dissemination system for NASA-relevant space weather information that combines forecasts based on the most advanced space weather models with concurrent space environment information. It will be customer configurable and adaptable for use as a powerful decision making tool offering an unprecedented ability to analyze the present and expected future space weather impacts on virtually all NASA human and robotic missions. We will discuss some of the key design considerations for the system and present some of the initial space weather analysis products that have been created to date.

  2. Progress in thermostructural analysis of space structures

    NASA Technical Reports Server (NTRS)

    Thornton, E. A.; Dechaumphai, P.; Mahaney, J.; Pandey, A. K.

    1982-01-01

    A finite element space structures research focused on the interdisciplinary problems of heating, thermal, and structural analysis is discussed. Slender member shadowing effects, and cable stiffened structures are described.

  3. Generation of stable and narrow spacing dual-wavelength ytterbium-doped fiber laser using a photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Ahmad, Harith; Aizi Mat Salim, Muhammad; Soltanian, Mohammad Reza K.; Razalli Azzuhri, Saaidal; Wadi Harun, Sulaiman; Yasin, Moh.

    2016-05-01

    We demonstrate the design and operation of novel narrow spacing and stable dual-wavelength fiber laser (DWFL). A 70-cm ytterbium-doped fiber has been chosen as the gain medium in a ring cavity arrangement. Our design includes a short length photonic crystal fiber, acting as a dual-wavelength stabilizer based on its birefringence coefficient and nonlinear behavior and tunable band pass filter (TBPF) to achieve narrow spacing spectrum lasing. Our laser output is considered to be highly stable, with power fluctuation less than 0.8 dB over a period of 15 min. The flexibility and tunability of TBPF, together with polarization controller enable the spacing tuning of the DWFL from 0.03 nm up to 0.07 nm for 1040 nm region, and 0.10 nm up to 0.40 nm for 1060 nm region. The tunable wavelength spacing shows the flexibility of the DWFL in addition to stable and reliable properties of fiber laser in 1-μm region.

  4. Integrated FDIR Analysis Tool for Space Applications

    NASA Astrophysics Data System (ADS)

    Piras, Annamaria; Malucchi, Giovanni; Di Tommaso, Umberto

    2013-08-01

    The crucial role of health management in space applications has been the subject of many studies carried out by NASA and ESA and is held in high regard by Thales Alenia Space. The common objective is to improve reliability and availability of space systems. This paper will briefly illustrate the evolution of IDEHAS (IntegrateD Engineering Harness Avionics and Software), an advanced tool currently used in Thales Alenia Space - Italy in several space programs and recently enhanced to fully support FDIR (Fault Detection Isolation and Recovery) analysis. The FDIR analysis logic flow will be presented, emphasizing the improvements offered to Mission Support & Operations activities. Finally the benefits provided to the Company and a list of possible future enhancements will be given.

  5. The Benefits of Acceleration: An Outcomes Analysis of Dual Enrollment

    ERIC Educational Resources Information Center

    Morrison, Michael C.

    2007-01-01

    This study adds to the growing body of research with a focus on (1) the characteristics of accelerated (dual enrolled) students versus their counterparts who did not participate in accelerated programs; (2) differences in academic outcomes of accelerated and non-accelerated students; and (3) differences in days to complete the associate degree for…

  6. Computational Analysis of Dual Radius Circulation Control Airfoils

    NASA Technical Reports Server (NTRS)

    Lee-Rausch, E. M.; Vatsa, V. N.; Rumsey, C. L.

    2006-01-01

    The goal of the work is to use multiple codes and multiple configurations to provide an assessment of the capability of RANS solvers to predict circulation control dual radius airfoil performance and also to identify key issues associated with the computational predictions of these configurations that can result in discrepancies in the predicted solutions. Solutions were obtained for the Georgia Tech Research Institute (GTRI) dual radius circulation control airfoil and the General Aviation Circulation Control (GACC) dual radius airfoil. For the GTRI-DR airfoil, two-dimensional structured and unstructured grid computations predicted the experimental trend in sectional lift variation with blowing coefficient very well. Good code to code comparisons between the chordwise surface pressure coefficients and the solution streamtraces also indicated that the detailed flow characteristics were matched between the computations. For the GACC-DR airfoil, two-dimensional structured and unstructured grid computations predicted the sectional lift and chordwise pressure distributions accurately at the no blowing condition. However at a moderate blowing coefficient, although the code to code variation was small, the differences between the computations and experiment were significant. Computations were made to investigate the sensitivity of the sectional lift and pressure distributions to some of the experimental and computational parameters, but none of these could entirely account for the differences in the experimental and computational results. Thus, CFD may indeed be adequate as a prediction tool for dual radius CC flows, but limited and difficult to obtain two-dimensional experimental data prevents a confident assessment at this time.

  7. State Approaches to Funding Dual Enrollment. ECS Education Policy Analysis

    ERIC Educational Resources Information Center

    Zinth, Jennifer

    2015-01-01

    Research shows that students who dually enroll are more likely to finish high school and succeed in postsecondary education than their peers with a similar grade point average (GPA), test scores, demographics, etc. Yet in many states, students and parents are largely--if not entirely--responsible for covering dual enrollment course costs, placing…

  8. Modeling and Analysis of Space Based Transceivers

    NASA Technical Reports Server (NTRS)

    Moore, Michael S.; Price, Jeremy C.; Abbott, Ben; Liebetreu, John; Reinhart, Richard C.; Kacpura, Thomas J.

    2007-01-01

    This paper presents the tool chain, methodology, and initial results of a study to provide a thorough, objective, and quantitative analysis of the design alternatives for space Software Defined Radio (SDR) transceivers. The approach taken was to develop a set of models and tools for describing communications requirements, the algorithm resource requirements, the available hardware, and the alternative software architectures, and generate analysis data necessary to compare alternative designs. The Space Transceiver Analysis Tool (STAT) was developed to help users identify and select representative designs, calculate the analysis data, and perform a comparative analysis of the representative designs. The tool allows the design space to be searched quickly while permitting incremental refinement in regions of higher payoff.

  9. Modeling and Analysis of Space Based Transceivers

    NASA Technical Reports Server (NTRS)

    Reinhart, Richard C.; Liebetreu, John; Moore, Michael S.; Price, Jeremy C.; Abbott, Ben

    2005-01-01

    This paper presents the tool chain, methodology, and initial results of a study to provide a thorough, objective, and quantitative analysis of the design alternatives for space Software Defined Radio (SDR) transceivers. The approach taken was to develop a set of models and tools for describing communications requirements, the algorithm resource requirements, the available hardware, and the alternative software architectures, and generate analysis data necessary to compare alternative designs. The Space Transceiver Analysis Tool (STAT) was developed to help users identify and select representative designs, calculate the analysis data, and perform a comparative analysis of the representative designs. The tool allows the design space to be searched quickly while permitting incremental refinement in regions of higher payoff.

  10. Failure Analysis at the Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Salazar, Victoria L.; Wright, M. Clara

    2010-01-01

    History has shown that failures occur in every engineering endeavor, and what we learn from those failures contributes to the knowledge base to safely complete future missions. The necessity of failure analysis is at its apex at the end of one aged program and at the beginning of a new and untested program. The information that we gain through failure analysis corrects the deficiencies in the current vehicle to make the next generation of vehicles more efficient and safe. The Failure Analysis and Materials Evaluation Branch in the Materials Science Division at the Kennedy Space Center performs metallurgical, mechanical, electrical, and non-metallic materials failure analyses and accident investigations on both flight hardware and ground support equipment for the Space Shuttle, International Space Station, Constellation, and Launch Services Programs. This paper will explore a variety of failure case studies at the Kennedy Space Center and the lessons learned that can be applied in future programs.

  11. Space station synergetic RAM-logistics analysis

    NASA Technical Reports Server (NTRS)

    Dejulio, Edmund T.; Leet, Joel H.

    1988-01-01

    NASA's Space Station Maintenance Planning and Analysis (MP&A) Study is a step in the overall Space Station Program to define optimum approaches for on-orbit maintenance planning and logistics support. The approach used in the MP&A study and the analysis process used are presented. Emphasis is on maintenance activities and processes that can be accomplished on orbit within the known design and support constraints of the Space Station. From these analyses, recommendations for maintainability/maintenance requirements are established. The ultimate goal of the study is to reduce on-orbit maintenance requirements to a practical and safe minimum, thereby conserving crew time for productive endeavors. The reliability, availability, and maintainability (RAM) and operations performance evaluation models used were assembled and developed as part of the MP&A study and are described. A representative space station system design is presented to illustrate the analysis process.

  12. Chung-Li, Taiwan dual mode (Doppler and spaced antenna) VHF radar: Preliminary specifications

    NASA Technical Reports Server (NTRS)

    Brosnahan, J. W.; Chao, J.; Rottger, J.

    1983-01-01

    A major unresolved question in the field of atmospheric research using VHF radar techniques is the relative merit of the two most widely used systems. These systems are the Doppler method and the spaced antenna method. It has been suggested that one radar of each type be operated side by side for a direct comparison of the two techniques. This duplication of effort is not cost effective. The major components of both systems are identical, and one radar could be operated in both modes by proper design of a suitable antenna system and by proper data analysis. The Chung-Li radar will be able to switch between modes on a time scale of seconds and is the first VHF radar to be able to directly compare the Doppler data with spaced antenna data. The system will have performance comparable with the present SOUSY spaced antenna system and will provide mesospheric data in addition to stratospheric and tropospheric data. The major specifications of the Chung-Li radar are given.

  13. Space Propulsion Design and Analysis

    NASA Technical Reports Server (NTRS)

    Sinha, Neeraj; Brinckman, Kevin; Ayyalasomayajula, Hanitha; Dash, Sanford

    2007-01-01

    This software provides an improved methodology for predicting launcher base pressure and heat loads for RSRM (Reusable Solid Rocket Motor) launchers by accounting for complex anisotropic stress/strains and variable turbulent Prandtl and Schmidt numbers. A "building block" approach to turbulence model development, and validation has been applied for improved missile/launcher base region analysis. Modifications to existing kappa - epsilon turbulence models and application of scalar variance models are incorporated into a RANS-based method for aeropropulsive flow modeling, directly related to base flow methodology. (RANS stands for Reynolds-averaged Navier-Stokes.) The models are applied in a RANS solver framework and can improve analysis of other complex flow fields. The enhanced models provide a more accurate predictive capability for improving the design and analysis of RSRM launcher configuration. The kappa - epsilon model enhancements have been shown to improve the capability for predicting turbulence effects in base blow environments. The scalar variance models have been assessed over a wide range of flow configurations to improve prediction of turbulent scalar mixing.

  14. Energy-filtered real- and k-space secondary and energy-loss electron imaging with Dual Emission Electron spectro-Microscope: Cs/Mo(110).

    PubMed

    Grzelakowski, Krzysztof P

    2016-05-01

    Since its introduction the importance of complementary k||-space (LEED) and real space (LEEM) information in the investigation of surface science phenomena has been widely demonstrated over the last five decades. In this paper we report the application of a novel kind of electron spectromicroscope Dual Emission Electron spectroMicroscope (DEEM) with two independent electron optical channels for reciprocal and real space quasi-simultaneous imaging in investigation of a Cs covered Mo(110) single crystal by using the 800eV electron beam from an "in-lens" electron gun system developed for the sample illumination. With the DEEM spectromicroscope it is possible to observe dynamic, irreversible processes at surfaces in the energy-filtered real space and in the corresponding energy-filtered kǁ-space quasi-simultaneously in two independent imaging columns. The novel concept of the high energy electron beam sample illumination in the cathode lens based microscopes allows chemically selective imaging and analysis under laboratory conditions. PMID:26520016

  15. Space Mission Human Reliability Analysis (HRA) Project

    NASA Technical Reports Server (NTRS)

    Boyer, Roger

    2014-01-01

    The purpose of the Space Mission Human Reliability Analysis (HRA) Project is to extend current ground-based HRA risk prediction techniques to a long-duration, space-based tool. Ground-based HRA methodology has been shown to be a reasonable tool for short-duration space missions, such as Space Shuttle and lunar fly-bys. However, longer-duration deep-space missions, such as asteroid and Mars missions, will require the crew to be in space for as long as 400 to 900 day missions with periods of extended autonomy and self-sufficiency. Current indications show higher risk due to fatigue, physiological effects due to extended low gravity environments, and others, may impact HRA predictions. For this project, Safety & Mission Assurance (S&MA) will work with Human Health & Performance (HH&P) to establish what is currently used to assess human reliabiilty for human space programs, identify human performance factors that may be sensitive to long duration space flight, collect available historical data, and update current tools to account for performance shaping factors believed to be important to such missions. This effort will also contribute data to the Human Performance Data Repository and influence the Space Human Factors Engineering research risks and gaps (part of the HRP Program). An accurate risk predictor mitigates Loss of Crew (LOC) and Loss of Mission (LOM).The end result will be an updated HRA model that can effectively predict risk on long-duration missions.

  16. Space station interior noise analysis program

    NASA Technical Reports Server (NTRS)

    Stusnick, E.; Burn, M.

    1987-01-01

    Documentation is provided for a microcomputer program which was developed to evaluate the effect of the vibroacoustic environment on speech communication inside a space station. The program, entitled Space Station Interior Noise Analysis Program (SSINAP), combines a Statistical Energy Analysis (SEA) prediction of sound and vibration levels within the space station with a speech intelligibility model based on the Modulation Transfer Function and the Speech Transmission Index (MTF/STI). The SEA model provides an effective analysis tool for predicting the acoustic environment based on proposed space station design. The MTF/STI model provides a method for evaluating speech communication in the relatively reverberant and potentially noisy environments that are likely to occur in space stations. The combinations of these two models provides a powerful analysis tool for optimizing the acoustic design of space stations from the point of view of speech communications. The mathematical algorithms used in SSINAP are presented to implement the SEA and MTF/STI models. An appendix provides an explanation of the operation of the program along with details of the program structure and code.

  17. Space station interior noise analysis program

    NASA Astrophysics Data System (ADS)

    Stusnick, E.; Burn, M.

    1987-02-01

    Documentation is provided for a microcomputer program which was developed to evaluate the effect of the vibroacoustic environment on speech communication inside a space station. The program, entitled Space Station Interior Noise Analysis Program (SSINAP), combines a Statistical Energy Analysis (SEA) prediction of sound and vibration levels within the space station with a speech intelligibility model based on the Modulation Transfer Function and the Speech Transmission Index (MTF/STI). The SEA model provides an effective analysis tool for predicting the acoustic environment based on proposed space station design. The MTF/STI model provides a method for evaluating speech communication in the relatively reverberant and potentially noisy environments that are likely to occur in space stations. The combinations of these two models provides a powerful analysis tool for optimizing the acoustic design of space stations from the point of view of speech communications. The mathematical algorithms used in SSINAP are presented to implement the SEA and MTF/STI models. An appendix provides an explanation of the operation of the program along with details of the program structure and code.

  18. Analysis of voids in crystal structures: the methods of 'dual' crystal chemistry.

    PubMed

    Blatov, V A; Shevchenko, A P

    2003-01-01

    The theoretical basics of the analysis of voids in crystal structures by means of Voronoi-Dirichlet polyhedra (VDP) and of the graph theory are stated. Topological relations are considered between VDPs and atomic domains in a crystal field. These relations allow the separation of two non-intersecting topological subspaces in a crystal structure, whose connectednesses are defined by two finite 'reduced' graphs. The first, 'direct', subspace includes the atoms (VDP centres) and the network of interatomic bonds (VDP faces), the second, 'dual', one comprises the void centres (VDP vertices) and the system of channels (VDP edges) between them. Computer methods of geometrical-topological analysis of the 'dual' subspace are developed and implemented within the program package TOPOS. They are designed for automatically restoring the system of channels, visualizing and sizing voids and void conglomerates, dimensional analysis of continuous void systems, and comparative topological analysis of 'dual' subspaces for various substances. The methods of analysis of 'dual' and 'direct' subspaces are noted to differ from each other only in some details that allows the term 'dual' crystal chemistry to be introduced. The efficiency of the methods is shown with the analysis of compounds of different chemical nature: simple substances, ionic structures, superionic conductors, zeolites, clathrates, organic supramolecular complexes. PMID:12496460

  19. Designing dual-plate meteoroid shields: A new analysis

    NASA Technical Reports Server (NTRS)

    Swift, H. F.; Bamford, R.; Chen, R.

    1982-01-01

    Physics governing ultrahigh velocity impacts onto dual-plate meteor armor is discussed. Meteoroid shield design methodologies are considered: failure mechanisms, qualitative features of effective meteoroid shield designs, evaluating/processing meteoroid threat models, and quantitative techniques for optimizing effective meteoroid shield designs. Related investigations are included: use of Kevlar cloth/epoxy panels in meteoroid shields for the Halley's Comet intercept vehicle, mirror exposure dynamics, and evaluation of ion fields produced around the Halley Intercept Mission vehicle by meteoroid impacts.

  20. Evenly spacing in Detrended Fluctuation Analysis

    NASA Astrophysics Data System (ADS)

    Almurad, Zainy M. H.; Delignières, Didier

    2016-06-01

    Detrended Fluctuation Analysis is a widely used method, which aims at assessing the level of self-similarity in time series. This method analyzes the diffusion properties of the signal, by computing the linear regression slope in the diffusion plot, representing in log-log coordinates the relationship between the variability of the signal and the length of the intervals over which this variability is computed. We compare in this paper the results obtained with logarithmically spaced and evenly spaced diffusion plots. The study shows the substantial benefits of evenly spacing, especially in the reduction of the variability of estimation.

  1. Contesting the Space between High School and College in the Era of Dual-Enrollment

    ERIC Educational Resources Information Center

    Tinberg, Howard; Nadeau, Jean-Paul

    2011-01-01

    In the new century, calls to promote "college readiness" among high school students have accelerated to a degree that would have astonished even the privileged and powerful colleges of the past. The most conspicuous evidence for such acceleration is the increasing popularity among schools, students, and colleges alike of dual-credit programs,…

  2. Space borne GPM dual-frequency radar simulation from high resolution ground radar observations.

    SciTech Connect

    Rose, C. R.; Chandrasekar, V.

    2004-01-01

    The Global Precipitation Measurement (GPM) mission is dedicated to improving the understanding of the global water cycle by measuring and mapping precipitation throughout the globe. The core GPM satellite will incorporate two separate precipitation radars: one operating at Ku-band (13.6 GHz) and the other at Ka band (35.6 GHz). Each radar beam will be steered such that they both point to the same location in the atmosphere. The main purpose of the dual-frequency radar system is to resolve the DSD in precipitation as well as discriminate between rain and ice. With the two beams collocated on the same precipitation volume, new algorithms are being developed to reliably es timate attenuation and rain rate. Any algorithm is based on models of precipitation. In addition, the GPM system assumes collocated beams and matched resolu tion volumes. Electromagnetic and microphysical models have been developed based on ground-based dual-frequency radar data at S-band to simulate Ku- and Ka-band results for comparison with the new GPM algorithms. This paper evaluates the dual-frequency inversion algorithm with synthesized S-band and known perfect data and presents results. Results show the expected performance of the new dual-precipitation radar algorithms with the potential for guiding algorithm and system improvements.

  3. Incremental Discriminant Analysis in Tensor Space

    PubMed Central

    Chang, Liu; Weidong, Zhao; Tao, Yan; Qiang, Pu; Xiaodan, Du

    2015-01-01

    To study incremental machine learning in tensor space, this paper proposes incremental tensor discriminant analysis. The algorithm employs tensor representation to carry on discriminant analysis and combine incremental learning to alleviate the computational cost. This paper proves that the algorithm can be unified into the graph framework theoretically and analyzes the time and space complexity in detail. The experiments on facial image detection have shown that the algorithm not only achieves sound performance compared with other algorithms, but also reduces the computational issues apparently. PMID:26339229

  4. International Space Station Remote Sensing Pointing Analysis

    NASA Technical Reports Server (NTRS)

    Jacobson, Craig A.

    2007-01-01

    This paper analyzes the geometric and disturbance aspects of utilizing the International Space Station for remote sensing of earth targets. The proposed instrument (in prototype development) is SHORE (Station High-Performance Ocean Research Experiment), a multiband optical spectrometer with 15 m pixel resolution. The analysis investigates the contribution of the error effects to the quality of data collected by the instrument. This analysis supported the preliminary studies to determine feasibility of utilizing the International Space Station as an observing platform for a SHORE type of instrument. Rigorous analyses will be performed if a SHORE flight program is initiated. The analysis begins with the discussion of the coordinate systems involved and then conversion from the target coordinate system to the instrument coordinate system. Next the geometry of remote observations from the Space Station is investigated including the effects of the instrument location in Space Station and the effects of the line of sight to the target. The disturbance and error environment on Space Station is discussed covering factors contributing to drift and jitter, accuracy of pointing data and target and instrument accuracies.

  5. Performance analysis of pseudo 4-phase dual-rail asynchronous protocol

    NASA Astrophysics Data System (ADS)

    Santhi, M.; Sarangan, Siddharth; Murali, K.; Lakshminarayanan, G.

    2012-08-01

    This article presents the performance analysis of novel pseudo 4-phase dual-rail protocol with self-reset and multiple-reset logic for high speed asynchronous applications. The self-reset logic eliminates the need for separate empty phase and hence reduces the number of transitions at the input and the output. The multiple-reset logic reduces the reset phase and hence increases the throughput. The performance of the pseudo 4-phase dual-rail protocol is compared with the existing 4-phase dual-rail protocol by implementing 8-bit and 16-bit asynchronously pipelined carry look ahead adders (CLA) in 0.35 µm technology. The time period decreases up to 32.58% and 35.93% respectively, the reset phase reduces up to 66.39% and 76.18%, respectively, and the operating frequency increases up to 48.4% and 56.2%, respectively, for 8- and 16-bit CLA adders with the pseudo 4-phase dual-rail protocol compared to the conventional 4-phase dual-rail protocol at the cost of increase in area of 8.8% and 3.3%, respectively. The delay-power product in ns-mW of the 8- and 16-bit CLAs is reduced at the maximum of 11.29% and 23.74%, respectively, with the pseudo 4-phase dual-rail protocol compared to the conventional 4-phase dual-rail protocol. The pseudo 4-phase dual-rail protocol is suitable for interfacing with synchronous environments.

  6. Failure Analysis at the Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Salazar, Victoria L.; Wright, Clara

    2010-01-01

    History has shown that failures occur in every engineering endeavor, and what we learn from those failures contributes to the knowledge base to safely complete future missions. The necessity of failure analysis is at its apex at the end of one aged program (i.e. Shuttle) and at the beginning of a new and untested program (i.e. Constellation). The information that we gain through failure analysis corrects the deficiencies in the current vehicle to make the next generation of vehicles more efficient and safe. The Failure Analysis and Materials Evaluation section in the Materials Science Division at the Kennedy Space Center performs metallurgical, mechanical, electrical, and non-metallic failure analysis and accident investigations on both flight hardware and ground support equipment (GSE) for the Shuttle, International Space Station, Constellation, and Launch Services Programs. This presentation will explore a variety of failure case studies at KSC and the lessons learned that can be applied in future programs.

  7. Dynamic modelling and analysis of space webs

    NASA Astrophysics Data System (ADS)

    Yu, Yang; Baoyin, HeXi; Li, JunFeng

    2011-04-01

    Future space missions demand operations on large flexible structures, for example, space webs, the lightweight cable nets deployable in space, which can serve as platforms for very large structures or be used to capture orbital objects. The interest in research on space webs is likely to increase in the future with the development of promising applications such as Furoshiki sat-ellite of JAXA, Robotic Geostationary Orbit Restorer (ROGER) of ESA and Grapple, Retrieve And Secure Payload (GRASP) of NASA. Unlike high-tensioned nets in civil engineering, space webs may be low-tensioned or tensionless, and extremely flexible, owing to the microgravity in the orbit and the lack of support components, which may cause computational difficulties. Mathematical models are necessary in the analysis of space webs, especially in the conceptual design and evaluation for prototypes. A full three-dimensional finite element (FE) model was developed in this work. Trivial truss elements were adopted to reduce the computational complexity. Considering cable is a compression-free material and its tensile stiffness is also variable, we introduced the cable material constitutive relationship to work out an accurate and feasible model for prototype analysis and design. In the static analysis, the stress distribution and global deformation of the webs were discussed to get access to the knowledge of strength of webs with different types of meshes. In the dynamic analysis, special attention was paid to the impact problem. The max stress and global deformation were investigated. The simulation results indicate the interesting phenomenon which may be worth further research.

  8. State-space formulations for flutter analysis

    NASA Technical Reports Server (NTRS)

    Weiss, S. J.; Tseng, K.; Morino, L.

    1976-01-01

    Various methods are presented and assessed for approximating the aerodynamic forces so that the State Space formulation and off-the-imaginary axis analysis are retained. The advantages of retaining these features are considerable, not only in simplifying the flutter analysis, but especially for more advanced applications such as optimal design of active control in which the flutter is merely a constraint to the optimization problem.

  9. Space Operations Center: A concept analysis

    NASA Technical Reports Server (NTRS)

    Livingston, L. E.

    1979-01-01

    The Space Operations Center is a concept for a shuttle-service, permanent, manned facility in low Earth orbit. An analysis of this concept was conducted and the results are reported. It is noted that there are no NASA plans at present to implement such a concept. The results are intended for consideration in future planning.

  10. Operational Aspects of Space Radiation Analysis

    NASA Technical Reports Server (NTRS)

    Weyland, M. D.; Johnson, A. S.; Semones, E. J.; Shelfer, T.; Dardano, C.; Lin, T.; Zapp, N. E.; Rutledge, R.; George, T.

    2005-01-01

    Minimizing astronaut's short and long-term medical risks arising from exposure to ionizing radiation during space missions is a major concern for NASA's manned spaceflight program, particularly exploration missions. For ethical and legal reasons, NASA follows the "as low as reasonably achievable" (ALARA) principal in managing astronaut's radiation exposures. One implementation of ALARA is the response to space weather events. Of particular concern are energetic solar particle events, and in low Earth orbit (LEO), electron belt enhancements. To properly respond to these events, NASA's Space Radiation Analysis Group (SRAG), in partnership with the NOAA Space Environment Center (SEC), provides continuous flight support during U.S. manned missions. In this partnership, SEC compiles space weather data from numerous ground and space based assets and makes it available in near real-time to SRAG (along with alerts and forecasts), who in turn uses these data as input to models to calculate estimates of the resulting exposure to astronauts. These calculations and vehicle instrument data form the basis for real-time recommendations to flight management. It is also important to implement ALARA during the design phase. In order to appropriately weigh the risks associated with various shielding and vehicle configuration concepts, the expected environment must be adequately characterized for nominal and worst case scenarios for that portion of the solar cycle and point in space. Even with the best shielding concepts and materials in place (unlikely), there will be numerous occasions where the crew is at greater risk due to being in a lower shielded environment (short term transit or lower shielded vehicles, EVAs), so that accurate space weather forecasts and nowcasts, of particles at the relevant energies, will be crucial to protecting crew health and safety.

  11. International Space Station Configuration Analysis and Integration

    NASA Technical Reports Server (NTRS)

    Anchondo, Rebekah

    2016-01-01

    Ambitious engineering projects, such as NASA's International Space Station (ISS), require dependable modeling, analysis, visualization, and robotics to ensure that complex mission strategies are carried out cost effectively, sustainably, and safely. Learn how Booz Allen Hamilton's Modeling, Analysis, Visualization, and Robotics Integration Center (MAVRIC) team performs engineering analysis of the ISS Configuration based primarily on the use of 3D CAD models. To support mission planning and execution, the team tracks the configuration of ISS and maintains configuration requirements to ensure operational goals are met. The MAVRIC team performs multi-disciplinary integration and trade studies to ensure future configurations meet stakeholder needs.

  12. Development of a Gimballed, dual frequency, space-based, microwave antenna for volume production

    NASA Technical Reports Server (NTRS)

    Leckie, Martin; Laidig, Dave

    1996-01-01

    A dual-frequency, two-axis Gimballed, Microwave Antenna (GMA) has been developed by COM DEV and Motorola for commercial satellites. The need for volume production of over three hundred antennas at a rate of four per week, a compressed development schedule, and the commercial nature of the effort necessitated a paradigm shift to an 'overall' cost-driven design approach. The translation of these demands into antenna requirements, a description of the resulting GMA design, and examples of development issues are detailed herein.

  13. Economic analysis of the space shuttle system, volume 1

    NASA Technical Reports Server (NTRS)

    1972-01-01

    An economic analysis of the space shuttle system is presented. The analysis is based on economic benefits, recurring costs, non-recurring costs, and ecomomic tradeoff functions. The most economic space shuttle configuration is determined on the basis of: (1) objectives of reusable space transportation system, (2) various space transportation systems considered and (3) alternative space shuttle systems.

  14. Space construction system analysis. Part 2: Space construction experiments concepts

    NASA Technical Reports Server (NTRS)

    Boddy, J. A.; Wiley, L. F.; Gimlich, G. W.; Greenberg, H. S.; Hart, R. J.; Lefever, A. E.; Lillenas, A. N.; Totah, R. S.

    1980-01-01

    Technology areas in the orbital assembly of large space structures are addressed. The areas included structures, remotely operated assembly techniques, and control and stabilization. Various large space structure design concepts are reviewed and their construction procedures and requirements are identified.

  15. Spectral analysis of groove spacing on Ganymede

    NASA Astrophysics Data System (ADS)

    Grimm, R. E.; Squyres, S. W.

    1985-02-01

    A quantitative analysis of groove spacing on Ganymede is described. Fourier transforms of a large number of photometric profiles across groove sets are calculated and the resulting power spectra are examined for the position and strength of peaks representing topographic periodicities. The geographic and global statistical distribution of groove wavelengths are examined, and these data are related to models of groove tectonism. It is found that groove spacing on Ganymede shows an approximately long-normal distribution with a minimum of about 3.5 km, a maximum of about 17 km, and a mean of 8.4 km. Groove spacing tends to be quite regular within a single groove set but can vary substantially from one groove set to another within a single geographic region.

  16. LABORATORY PROCEDURES: ANALYSIS OF SODIUM-BASED DUAL-ALKALI PROCESS STREAMS

    EPA Science Inventory

    The report gives procedures for chemical analysis of process streams of a flue gas desulfurization (FGD) system (utilizing the Combustion Equipment Associates/Arthur D. Little sodium-based dual-alkali process) at Louisville Gas and Electric's Cane Run Unit 6. The U. S. EPA has co...

  17. A Cost-Benefit Analysis of an International Dual Degree Programme

    ERIC Educational Resources Information Center

    Asgary, Nader; Robbert, Mary Ann

    2010-01-01

    This paper provides a cost benefit analysis of undergraduate and graduate international dual degree programmes, which are relatively new and innovative educational approaches to preparing students to succeed in a contemporary international arena. A comparative model of international educational and experiential systems is offered and examples of…

  18. Uniting Secondary and Postsecondary Education: An Event History Analysis of State Adoption of Dual Enrollment Policies

    ERIC Educational Resources Information Center

    Mokher, Christine G.; McLendon, Michael K.

    2009-01-01

    This study, as the first empirical test of P-16 policy antecedents, reports the findings from an event history analysis of the origins of state dual enrollment policies adopted between 1976 and 2005. First, what characteristics of states are associated with the adoption of these policies? Second, to what extent do conventional theories on policy…

  19. RADIOCHEMICAL ANALYSIS BY HIGH SENSITIVITY DUAL-OPTIC MICRO X-RAY FLUORESCENCE

    EPA Science Inventory

    A novel dual-optic micro X-ray fluorescence instrument will be developed to do radiochemical analysis of high-level radioactive wastes at DOE sites such as Savannah River Site and Hanford. This concept incorporates new X-ray optical elements such as monolithic polycapillaries and...

  20. Stable narrow spacing dual-wavelength Q-switched graphene oxide embedded in a photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Ahmad, H.; Soltanian, M. R. K.; Alimadad, M.; Harun, S. W.

    2014-10-01

    An ultra-stable dual-wavelength saturable absorber based on a cladding-embedded commercial graphene oxide (GO) solution by capillary action in a solid core photonic crystal fiber (PCF) is demonstrated for the first time. The saturation absorption property is achieved through evanescent coupling between the guided light and the cladding-filled graphene layers. Stable spacing dual-wavelength fiber lasing is attained by controlling the polarization state of a simple 0.9 m long ring of highly doped Leikki Er80-8/125 erbium-doped fiber as the primary gain medium with PCF, polarization controller and tunable bandpass filter. Embedded GO is used to generate the desired pulsed output, and the laser is capable of generating pulses having a repetition rate of 24 kHz with an average output power and pulse energy of 0.167 mW and 8.98 nJ, respectively, at the maximum pump power of 220 mW.

  1. Thermodynamic Analysis of Dual-Mode Scramjet Engine Operation and Performance

    NASA Technical Reports Server (NTRS)

    Riggins, David; Tacket, Regan; Taylor, Trent; Auslender, Aaron

    2006-01-01

    Recent analytical advances in understanding the performance continuum (the thermodynamic spectrum) for air-breathing engines based on fundamental second-law considerations have clarified scramjet and ramjet operation, performance, and characteristics. Second-law based analysis is extended specifically in this work to clarify and describe the performance characteristics for dual-mode scramjet operation in the mid-speed range of flight Mach 4 to 7. This is done by a fundamental investigation of the complex but predictable interplay between heat release and irreversibilities in such an engine; results demonstrate the flow and performance character of the dual mode regime and of dual mode transition behavior. Both analytical and computational (multi-dimensional CFD) studies of sample dual-mode flow-fields are performed in order to demonstrate the second-law capability and performance and operability issues. The impact of the dual-mode regime is found to be characterized by decreasing overall irreversibility with increasing heat release, within the operability limits of the system.

  2. Dual processing and discourse space: Exploring fifth grade students' language, reasoning, and understanding through writing

    NASA Astrophysics Data System (ADS)

    Yoon, Sae Yeol

    The purpose of this study was to explore the development of students' understanding through writing while immersed in an environment where there was a strong emphasis on a language-based argument inquiry approach. Additionally, this study explored students' spoken discourse to gain a better understanding of what role(s) talking plays in the development of understanding through writing. Finally, the study proposed a new concept of Discourse Space, which enabled researchers to improve their understanding of the characteristics of the development of student cognition through writing, and of the roles talking plays in cognitive development through writing. This study was guided by the research question: What patterns of the development of fifth grade students' cognition over time emerge in their private and public negotiations under a teacher who is ranked as a low-level implementer of the SWH approach? This question was divided into two sub-questions: (a) Throughout a unit, Ecosystems, what patterns emerge regarding the development of six fifth grade students' understanding through writing, and b) What patterns of the development of Discourse Space emerge through talking in three different contexts. In order to answer these questions, this qualitative research employed a generic qualitative study. Twenty-one fifth grade students participated in this study, and six students were purposefully selected through which to further investigate the development of an understanding of science through private negotiation while immersed in a language-based argument inquiry approach. Major data sources included students' writing samples, informal conversations with the teacher, researcher's field notes, and classroom videos. Additionally, the teacher's modified RTOP scores and semi-structured interviews were used to deepen the contextual understanding of the learning environment and the teacher's instructional performance. The data analysis was conducted by utilizing discourse

  3. Cost-benefit analysis of space technology

    NASA Technical Reports Server (NTRS)

    Hein, G. F.; Stevenson, S. M.; Sivo, J. N.

    1976-01-01

    A discussion of the implications and problems associated with the use of cost-benefit techniques is presented. Knowledge of these problems is useful in the structure of a decision making process. A methodology of cost-benefit analysis is presented for the evaluation of space technology. The use of the methodology is demonstrated with an evaluation of ion thrusters for north-south stationkeeping aboard geosynchronous communication satellites. A critique of the concept of consumers surplus for measuring benefits is also presented.

  4. Functional Analysis of Dual-Specificity Protein Phosphatases in Angiogenesis.

    PubMed

    Amand, Mathieu; Erpicum, Charlotte; Gilles, Christine; Noël, Agnès; Rahmouni, Souad

    2016-01-01

    Therapeutic perspectives targeting angiogenesis in cancer stimulated an intense investigation of the mechanisms triggering and governing angiogenic processes. Several publications have highlighted the importance of typical dual-specificity phosphatases (DSPs) or MKPs in endothelial cells and their role in controlling different biological functions implicated in angiogenesis such as migration, proliferation, apoptosis, tubulogenesis, and cell adhesion. However, among atypical DSPs, the only one investigated in angiogenesis was DUSP3. We recently identified this DSP as a new key player in endothelial cells and angiogenesis. In this chapter we provide with detailed protocols and models used to investigate the role of DUSP3 in endothelial cells and angiogenesis. We start the chapter with an overview of the role of several DSPs in angiogenesis. We continue with providing a full description of a highly efficient transfection protocol to deplete DUSP3 using small interfering RNA (siRNA) in the primary human umbilical vein endothelial cells (HUVEC). We next describe the major assays used to investigate different processes involved in angiogenesis such as tube formation assay, proliferation assay and spheroids sprouting assay. We finish the chapter by validating our results in DUSP3-knockout mice using in vivo angiogenesis assays such as Matrigel plug and Lewis lung carcinoma cell subcutaneous xenograft model followed by anti-CD31 immunofluorescence and ex vivo aortic ring assay. All methods described can be adapted to other phosphatases and signaling molecules. PMID:27514814

  5. Dual mode use requirements analysis for the institutional cluster.

    SciTech Connect

    Leland, Robert W.

    2003-09-01

    This paper analyzes what additional costs would be incurred in supporting dual-mode, i.e. both classified and unclassified use of the Institutional Computing (IC) hardware. The following five options are considered: periods processing in which a fraction of the system alternates in time between classified and unclassified modes, static split in which the system is constructed as a set of smaller clusters which remain in one mode or the other, re-configurable split in which the system is constructed in a split fashion but a mechanism is provided to reconfigure it very infrequently, red/black switching in which a mechanism is provided to switch sections of the system between modes frequently, and complementary operation in which parts of the system are operated entirely in one mode at one geographical site and entirely in the other mode at the other geographical site and other systems are repartitioned to balance work load. These options are evaluated against eleven criteria such as disk storage costs, distance computing costs, reductions in capability and capacity as a result of various factors etc. The evaluation is both qualitative and quantitative, and is captured in various summary tables.

  6. Static-stress analysis of dual-axis confinement vessel

    NASA Astrophysics Data System (ADS)

    Bultman, D. H.

    1992-11-01

    This study evaluates the static-pressure containment capability of a 6-ft-diameter, spherical vessel, made of HSLA-100 steel, to be used for high-explosive (HE) containment. The confinement vessel is designed for use with the Dual-Axis Radiographic Hydrotest Facility (DARHT) being developed at Los Alamos National Laboratory. Two sets of openings in the vessel are covered with x-ray transparent covers to allow radiographic imaging of an explosion as it occurs inside the vessel. The confinement vessel is analyzed as a pressure vessel based on the ASME Boiler and Pressure Vessel Code, Section 8, Division 1, and the Welding Research Council Bulletin, WRC-107. Combined stresses resulting from internal pressure and external loads on nozzles are calculated and compared with the allowable stresses for HSLA-100 steel. Results confirm that the shell and nozzles of the confinement vessel are adequately designed to safely contain the maximum residual pressure of 1675 psi that would result from an HE charge of 24.2 kg detonated in a vacuum. Shell stresses at the shell-to-nozzle interface, produced from external loads on the nozzles, were less than 400 psi. The maximum combined stress resulting from the internal pressure plus external loads was 16,070 psi, which is less than half the allowable stress of 42,375 psi for HSLA-100 steel.

  7. Static-stress analysis of dual-axis safety vessel

    NASA Astrophysics Data System (ADS)

    Bultman, D. H.

    1992-11-01

    An 8 ft diameter safety vessel, made of HSLA-100 steel, is evaluated to determine its ability to contain the quasi-static residual pressure from a high explosive (HE) blast. The safety vessel is designed for use with the Dual-Axis Radiographic Hydrotest (DARHT) facility being developed at Los Alamos National Laboratory. A smaller confinement vessel fits inside the safety vessel and contains the actual explosion, and the safety vessel functions as a second layer of containment in the unlikely case of a confinement vessel leak. The safety vessel is analyzed as a pressure vessel based on the ASME Boiler and Pressure Vessel Code, Section 8, Division 1, and the Welding Research Council Bulletin, WRC107. Combined stresses that result from internal pressure and external loads on nozzles are calculated and compared to the allowable stresses for HSLA-100 steel. Results confirm that the shell and nozzle components are adequately designed for a static pressure of 830 psi, plus the maximum expected external loads. Shell stresses at the 'shell to nozzle' interface, produced from external loads on the nozzles, were less than 700 psi. The maximum combined stress resulting from the internal pressure plus external loads was 17,384 psi, which is significantly less than the allowable stress of 42,375 psi for HSLA-100 steel.

  8. The ESA's Space Trajectory Analysis software suite

    NASA Astrophysics Data System (ADS)

    Ortega, Guillermo

    The European Space Agency (ESA) initiated in 2005 an internal activity to develop an open source software suite involving university science departments and research institutions all over the world. This project is called the "Space Trajectory Analysis" or STA. This article describes the birth of STA and its present configuration. One of the STA aims is to promote the exchange of technical ideas, and raise knowledge and competence in the areas of applied mathematics, space engineering, and informatics at University level. Conceived as a research and education tool to support the analysis phase of a space mission, STA is able to visualize a wide range of space trajectories. These include among others ascent, re-entry, descent and landing trajectories, orbits around planets and moons, interplanetary trajectories, rendezvous trajectories, etc. The article explains that STA project is an original idea of the Technical Directorate of ESA. It was born in August 2005 to provide a framework in astrodynamics research at University level. As research and education software applicable to Academia, a number of Universities support this development by joining ESA in leading the development. ESA and Universities partnership are expressed in the STA Steering Board. Together with ESA, each University has a chair in the board whose tasks are develop, control, promote, maintain, and expand the software suite. The article describes that STA provides calculations in the fields of spacecraft tracking, attitude analysis, coverage and visibility analysis, orbit determination, position and velocity of solar system bodies, etc. STA implements the concept of "space scenario" composed of Solar system bodies, spacecraft, ground stations, pads, etc. It is able to propagate the orbit of a spacecraft where orbital propagators are included. STA is able to compute communication links between objects of a scenario (coverage, line of sight), and to represent the trajectory computations and

  9. Performance and Operational Characteristics for a Dual Brayton Space Power System With Common Gas Inventory

    NASA Technical Reports Server (NTRS)

    Johnson, Paul K.; Mason, Lee S.

    2006-01-01

    This paper provides an analytical evaluation on the operation and performance of a dual Brayton common gas system. The NASA Glenn Research Center in-house computer program Closed Cycle System Simulation (CCSS) was used to construct a model of two identical 50 kWe-class recuperated closed-Brayton-cycle (CBC) power conversion units that share a common gas inventory and single heat source. As operating conditions for each CBC change, the total gas inventory is redistributed between the two units and overall system performance is affected. Several steady-state off-design operating points were analyzed by varying turbine inlet temperature and turbo-alternator shaft rotational speed to investigate the interaction of the two units.

  10. Merger-driven fueling of active galactic nuclei: Six dual and of AGNs discovered with Chandra and Hubble Space Telescope observations

    DOE PAGESBeta

    Comerford, Julia M.; Pooley, David; Barrows, R. Scott; Greene, Jenny E.; Zakamska, Nadia L.; Madejski, Greg M.; Cooper, Michael C.

    2015-06-19

    Dual active galactic nuclei (AGNs) and offset AGNs are kpc-scale separation supermassive black holes pairs created during galaxy mergers, where both or one of the black holes are AGNs, respectively. These dual and offset AGNs are valuable probes of the link between mergers and AGNs but are challenging to identify. Here we present Chandra/ACIS observations of 12 optically selected dual AGN candidates atmore » $$z\\lt 0.34$$, where we use the X-rays to identify AGNs. We also present Hubble Space Telescope/Wide Field Camera 3 observations of 10 of these candidates, which reveal any stellar bulges accompanying the AGNs. We discover a dual AGN system with separation $${\\rm \\Delta }x=2.2$$ kpc, where the two stellar bulges have coincident [O iii] λ5007 and X-ray sources. This system is an extremely minor merger (460:1) that may include a dwarf galaxy hosting an intermediate mass black hole. We also find six single AGNs, and five systems that are either dual or offset AGNs with separations $${\\rm \\Delta }x\\lt 10$$ kpc. Four of the six dual AGNs and dual/offset AGNs are in ongoing major mergers, and these AGNs are 10 times more luminous, on average, than the single AGNs in our sample. This hints that major mergers may preferentially trigger higher luminosity AGNs. Further, we find that confirmed dual AGNs have hard X-ray luminosities that are half of those of single AGNs at fixed [O III] λ5007 luminosity, on average. Lastly, this could be explained by high densities of gas funneled to galaxy centers during mergers, and emphasizes the need for deeper X-ray observations of dual AGN candidates.« less

  11. Risk analysis of space transportation during the space station era

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This study addresses the operational risks of manned space transportation during the era of space station deployment along with alternative launch vehicle architectures to reduce the risks. Vehicle architectures considered included shuttle only, an additional unmanned launch vehicle, and a second manned/unmanned launch vehicle. Projections are made for the operational parameters and flight event probabilities. Using these projections and Space Station era mission models, the operability of alternative vehicle architectures are examined, and implications to future manned space program plans are summarized.

  12. Dual-use tools and systematics-aware analysis workflows in the ATLAS Run-2 analysis model

    NASA Astrophysics Data System (ADS)

    Adams, David; Calafiura, Paolo; Delsart, Pierre-Antoine; Elsing, Markus; Farrell, Steven; Koeneke, Karsten; Krasznahorkay, Attila; Krumnack, Nils; Lancon, Eric; Lavrijsen, Wim; Laycock, Paul; Lei, Xiaowen; Strandberg, Sara; Verkerke, Wouter; Vivarelli, Iacopo; Woudstra, Martin

    2015-12-01

    The ATLAS analysis model has been overhauled for the upcoming run of data collection in 2015 at 13 TeV. One key component of this upgrade was the Event Data Model (EDM), which now allows for greater flexibility in the choice of analysis software framework and provides powerful new features that can be exploited by analysis software tools. A second key component of the upgrade is the introduction of a dual-use tool technology, which provides abstract interfaces for analysis software tools to run in either the Athena framework or a ROOT-based framework. The tool interfaces, including a new interface for handling systematic uncertainties, have been standardized for the development of improved analysis workflows and consolidation of high-level analysis tools. This paper will cover the details of the dual-use tool functionality, the systematics interface, and how these features fit into a centrally supported analysis environment.

  13. Analysis of Designs of Space Laboratories

    NASA Technical Reports Server (NTRS)

    Cohen, Marc M.

    2003-01-01

    A report presents a review of the development of laboratories in outer space, starting from the pioneering Skylab and Salyut stations of the United States and the former Soviet Union and progressing through current and anticipated future developments. The report includes textual discussions of space station designs, illustrated with drawings, photographs, and tables. The approach taken in the review was not to provide a comprehensive catalog of each space laboratory and every design topic that applies to it, but, rather, to illustrate architectural precedents by providing examples that illustrate major design problems and principles to be applied in solving them. Hence, the report deemphasizes information from the most recent space-station literature and concentrates on information from original design reports that show how designs originated and evolved. The most important contribution of the review was the development of a methodology, called "units of analysis," for identifying and analyzing design issues from the perspectives of four broad domains: laboratory science, crew, modes of operations, and the system as a whole.

  14. A Comparative Study of High School Advanced Placement and Dual Enrollment Programs Using a Mixed Methods Analysis

    ERIC Educational Resources Information Center

    Haley, Katrina A.

    2013-01-01

    This study provides an in-depth analysis of whether students who take dual enrollment and/or AP classes have higher ACT test scores compared to a group of their peers that did not take dual enrollment or AP courses. The study also identified the demographic characteristics (ethnicity, gender, and socio-economic status) of students with a 3.0 or…

  15. Mission Success Driven Space System Sparing Analysis

    NASA Technical Reports Server (NTRS)

    Knezevic, J.

    1995-01-01

    Among the maintenance resources, the spare parts are the most difficult to predict. Items in the space systems are very different from the point of view of reliability, cost, weight, volume, etc. The different combinations of spares make different contribution to the: mission success, spare investment, volume occupied and weight. Hence, the selection of spares for a mission planned must take into account all of these features. This paper presents the generic mission success driven sparing model developed, for the complex space systems. The mathematical analysis used in the model enables the user to select the most suitable selection of the spare package for the mission planned. The illustrative examples presented clearly demonstrate the applicability and usefulness of the model introduced.

  16. A lightweight high performance dual-axis gimbal for space applications

    SciTech Connect

    Pines, D.J.; Hakala, D.B.; Malueg, R.

    1995-05-05

    This paper describes the design, development and performance of a lightweight precision gimbal with dual-axis slew capability to be used in a closed-loop optical tracking system at Lawrence Livermore National Laboratory-LLNL. The motivation for the development of this gimbal originates from the need to acquire and accurately localize warm objects (T{approximately}500 K) in a cluttered background. The design of the gimbal is centered around meeting the following performance requirements: pointing accuracy with control < 35 {mu}rad-(1-{omega}); slew capability > 0.2 rad/sec; mechanical weight < 5 kg. These performance requirements are derived by attempting to track a single target from multiple satellites in low Earth orbit using a mid-wave infrared camera. Key components in the gimbal hardware that are essential to meeting the performance objectives include a nickel plated beryllium mirro, an accurate lightweight capacitive pickoff device for angular measurement about the elevation axis, a 16-bit coarse/fine resolver for angular measurement about the azimuth axis, a toroidally wound motor with low hysteresis for providing torque about the azimuth axis, and the selection of beryllium parts to insure high stiffness to weight ratios and more efficient thermal conductivity. Each of these elements are discussed in detail to illustrate the design trades performed to meet the tracking and slewing requirements demanded. Preliminary experimental results are also given for various commanded tracking maneuvers.

  17. Single- and dual-fractal analysis of hydridization binding kinetics: Biosensor applications

    SciTech Connect

    Sadana, A.; Vo-Dinh, T.

    1998-09-01

    The diffusion-limited hybridization kinetics of analyte in solution to a receptor immobilized on a biosensor or immunosensor surface is analyzed within a fractal framework. The data may be analyzed by a single- or a dual-fractal analysis. This was indicated by the regression analysis provided by sigmaplot. It is of interest to note that the binding rate coefficient and the fractal dimension both exhibit changes in the same direction for both the single-fractal and the dual-fractal analysis examples presented. For example, for a single-fractal analysis and for the hybridization of 10 nM 16*CFl (oligonucleotide) to 16*B immobilized via sulfosuccinimidyl-6-(biotinamido)-hexanoate and streptavidin using chemical and thermal regeneration, an increase in the fractal dimension, D{sub f} from 1.211 to 1.394, leads to an increase in the binding rate coefficient, k, from 86.53 to 100.0. An increase in the degree of heterogeneity on the biosensor surface leads to an increase in the binding rate coefficient. When a dual-fractal analysis was utilized, an increase in the fractal dimension value from D{sub f1} to D{sub f2} leads to an increase in the binding rate coefficient value from k{sub 1} to k{sub 2}.

  18. Dual parallel mass spectrometry for lipid and vitamin D analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are numerous options for mass spectrometric analysis of lipids, including different types of ionization, and a wide variety of experiments using different scan modes that can be conducted. Atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) provide complementary ...

  19. Tilt-Sensitivity Analysis for Space Telescopes

    NASA Technical Reports Server (NTRS)

    Papalexandris, Miltiadis; Waluschka, Eugene

    2003-01-01

    A report discusses a computational-simulation study of phase-front propagation in the Laser Interferometer Space Antenna (LISA), in which space telescopes would transmit and receive metrological laser beams along 5-Gm interferometer arms. The main objective of the study was to determine the sensitivity of the average phase of a beam with respect to fluctuations in pointing of the beam. The simulations account for the effects of obscurations by a secondary mirror and its supporting struts in a telescope, and for the effects of optical imperfections (especially tilt) of a telescope. A significant innovation introduced in this study is a methodology, applicable to space telescopes in general, for predicting the effects of optical imperfections. This methodology involves a Monte Carlo simulation in which one generates many random wavefront distortions and studies their effects through computational simulations of propagation. Then one performs a statistical analysis of the results of the simulations and computes the functional relations among such important design parameters as the sizes of distortions and the mean value and the variance of the loss of performance. These functional relations provide information regarding position and orientation tolerances relevant to design and operation.

  20. Engine performance analysis and optimization of a dual-mode scramjet with varied inlet conditions

    NASA Astrophysics Data System (ADS)

    Tian, Lu; Chen, Li-Hong; Chen, Qiang; Zhong, Feng-Quan; Chang, Xin-Yu

    2016-02-01

    A dual-mode scramjet can operate in a wide range of flight conditions. Higher thrust can be generated by adopting suitable combustion modes. Based on the net thrust, an analysis and preliminary optimal design of a kerosene-fueled parameterized dual-mode scramjet at a crucial flight Mach number of 6 were investigated by using a modified quasi-one-dimensional method and simulated annealing strategy. Engine structure and heat release distributions, affecting the engine thrust, were chosen as analytical parameters for varied inlet conditions (isolator entrance Mach number: 1.5-3.5). Results show that different optimal heat release distributions and structural conditions can be obtained at five different inlet conditions. The highest net thrust of the parameterized dual-mode engine can be achieved by a subsonic combustion mode at an isolator entrance Mach number of 2.5. Additionally, the effects of heat release and scramjet structure on net thrust have been discussed. The present results and the developed analytical method can provide guidance for the design and optimization of high-performance dual-mode scramjets.

  1. Novel Materials, Processing, and Device Technologies for Space Exploration with Potential Dual-Use Applications

    NASA Technical Reports Server (NTRS)

    Hepp, A. F.; Bailey, S. G.; McNatt, J. S.; Chandrashekhar, M. V. S.; Harris, J. D.; Rusch, A. W.; Nogales, K. A.; Goettsche, K. V.; Hanson, W.; Amos, D.; Vendra, V. K.; Woodbury, C.; Hari, P.; Roberts, K. P.; Jones, A. D., Jr.

    2015-01-01

    We highlight results of a broad spectrum of efforts on lower-temperature processing of nanomaterials, novel approaches to energy conversion, and environmentally rugged devices. Solution-processed quantum dots of copper indium chalcogenide semiconductors and multi-walled carbon nanotubes from lower-temperature spray pyrolysis are enabled by novel (precursor) chemistry. Metal-doped zinc oxide (ZnO) nanostructured components of photovoltaic cells have been grown in solution at low temperature on a conductive indium tin oxide substrate. Arrays of ZnO nanorods can be templated and decorated with various semiconductor and metallic nanoparticles. Utilizing ZnO in a more broadly defined energy conversion sense as photocatalysts, unwanted organic waste materials can potentially be re-purposed. Current efforts on charge carrier dynamics in nanoscale electrode architectures used in photoelectrochemical cells for generating solar electricity and fuels are described. The objective is to develop oxide nanowire-based electrode architectures that exhibit improved charge separation, charge collection and allow for efficient light absorption. Investigation of the charge carrier transport and recombination properties of the electrodes will aid in the understanding of how nanowire architectures improve performance of electrodes for dye-sensitized solar cells. Nanomaterials can be incorporated in a number of advanced higher-performance (i.e. mass specific power) photovoltaic arrays. Advanced technologies for the deposition of 4H-silicon carbide are described. The use of novel precursors, advanced processing, and process studies, including modeling are discussed from the perspective of enhancing the performance of this promising material for enabling technologies such as solar electric propulsion. Potential impact(s) of these technologies for a variety of aerospace applications are highlighted throughout. Finally, examples are given of technologies with potential spin-offs for dual

  2. Novel Materials, Processing and Device Technologies for Space Exploration with Potential Dual-Use Applications

    NASA Technical Reports Server (NTRS)

    Hepp, A. F.; Bailey, S. G.; McNatt, J. S.; Chandrashekhar, M. V. S.; Harris, J. D.; Rusch, A. W.; Nogales, K. A.; Goettsche, K.V.; Hanson, W.; Amos, D.; Vendra, M. K.; Woodbury, C.; Hari, P.; Roberts, K. P.; Jones, A. D., Jr.

    2014-01-01

    We highlight results of a broad spectrum of efforts on lower-temperature processing of nanomaterials, novel approaches to energy conversion, and environmentally rugged devices. Solution-processed quantum dots of copper indium chalcogenide semiconductors and multiwalled carbon nanotubes from lower-temperature spray pyrolysis are enabled by novel (precursor) chemistry. Metal-doped zinc oxide (ZnO) nanostructured components of photovoltaic cells have been grown in solution at low temperature on a conductive indium tin oxide substrate. Arrays of ZnO nanorods can be templated and decorated with various semiconductor and metallic nanoparticles. Utilizing ZnO in a more broadly defined energy conversion sense as photocatalysts, unwanted organic waste materials can potentially be repurposed. Current efforts on charge carrier dynamics in nanoscale electrode architectures used in photoelectrochemical cells for generating solar electricity and fuels are described. The objective is to develop oxide nanowire-based electrode architectures that exhibit improved charge separation, charge collection and allow for efficient light absorption. Investigation of the charge carrier transport and recombination properties of the electrodes will aid in the understanding of how nanowire architectures improve performance of electrodes for dye-sensitized solar cells. Nanomaterials can be incorporated in a number of advanced higher-performance (i.e. mass specific power) photovoltaic arrays. Advanced technologies for the deposition of 4H-silicon carbide are described. The use of novel precursors, advanced processing, and process studies, including modeling are discussed from the perspective of enhancing the performance of this promising material for enabling technologies such as solar electric propulsion. Potential impact(s) of these technologies for a variety of aerospace applications are highlighted throughout. Finally, examples are given of technologies with potential spin-offs for dual-use or

  3. Analysis of a dual grating-type surface emitting laser

    SciTech Connect

    Hardy, A.; Welch, D.F.; Streifer, W. )

    1990-01-01

    The authors report the results of a grating coupled surface emitter (GSE) analysis. The GSE consists of a gain section between two gratings sections, that are not necessarily identical. The gratings act both as distributed Bragg reflectors and output couplers via radiation. The analysis applies to arbitrary grating tooth shapes and has provisions to include the presence of a substrate reflector to reduce the radiated power into that medium. Thresholds, differential efficiencies, and far-field patterns are computed for the low threshold longitudinal modes of the system. Examples illustrating variations in tooth shapes and heights, waveguide loss, the presence of a substrate reflector, and detuning from the Bragg condition are included.

  4. Wavelet Analysis of Space Solar Telescope Images

    NASA Astrophysics Data System (ADS)

    Zhu, Xi-An; Jin, Sheng-Zhen; Wang, Jing-Yu; Ning, Shu-Nian

    2003-12-01

    The scientific satellite SST (Space Solar Telescope) is an important research project strongly supported by the Chinese Academy of Sciences. Every day, SST acquires 50 GB of data (after processing) but only 10GB can be transmitted to the ground because of limited time of satellite passage and limited channel volume. Therefore, the data must be compressed before transmission. Wavelets analysis is a new technique developed over the last 10 years, with great potential of application. We start with a brief introduction to the essential principles of wavelet analysis, and then describe the main idea of embedded zerotree wavelet coding, used for compressing the SST images. The results show that this coding is adequate for the job.

  5. A Task that Elicits Reasoning: A Dual Analysis

    ERIC Educational Resources Information Center

    Yankelewitz, Dina; Mueller, Mary; Maher, Carolyn A.

    2010-01-01

    This paper reports on the forms of reasoning elicited as fourth grade students in a suburban district and sixth grade students in an urban district worked on similar tasks involving reasoning with the use of Cuisenaire rods. Analysis of the two data sets shows similarities in the reasoning used by both groups of students on specific tasks, and the…

  6. Medical impact analysis for the Space Station

    NASA Technical Reports Server (NTRS)

    Nelson, Brent D.; Gardner, Reed M.; Ostler, David V.; Schulz, John M.; Logan, James S.

    1990-01-01

    In this study, Space Station medical care priorities were determined by a medical impact analysis of two analog populations, U.S. Army and U.S. Navy personnel. Diseases and injuries in the International Classification of Disease, 9th Revision, Clinical Modification (ICD-9-CM) were ranked, using a Medical Impact Score (MIS) combining modified incidence rate and a function of disease outcome. The validity of the analysis method was tested by measuring rank order correlation between the two analog populations. Despite virtually identical age and sex distributions, Army and Navy incidence rates differed significantly for half of the ICD-9-CM categories, p less than 0.05. Disability rates differed for 76 percent, p less than 0.05. Nevertheless, Army and Navy MIS rank orders for categories and sections were not significantly different, p less than 0.001. In critical ways, the Space Station will be a safer environment than earth. Cardiac events, musculoskeletal injuries, affective psychoses, and renal calculi were among the highest scoring categories.

  7. Modeling, Analysis, and Optimization Issues for Large Space Structures

    NASA Technical Reports Server (NTRS)

    Pinson, L. D. (Compiler); Amos, A. K. (Compiler); Venkayya, V. B. (Compiler)

    1983-01-01

    Topics concerning the modeling, analysis, and optimization of large space structures are discussed including structure-control interaction, structural and structural dynamics modeling, thermal analysis, testing, and design.

  8. System-level Analysis of Food Moisture Content Requirements for the Mars Dual Lander Transit Mission

    NASA Technical Reports Server (NTRS)

    Levri, Julie A.; Perchonok, Michele H.

    2004-01-01

    In order to ensure that adequate water resources are available during a mission, any net water loss from the habitat must be balanced with an equivalent amount of required makeup water. Makeup water may come from a variety of sources, including water in shipped tanks, water stored in prepackaged food, product water from fuel cells, and in-situ water resources. This paper specifically addresses the issue of storing required makeup water in prepackaged food versus storing the water in shipped tanks for the Mars Dual Lander Transit Mission, one of the Advanced Life Support Reference Missions. In this paper, water mass balances have been performed for the Dual Lander Transit Mission, to determine the necessary requirement of makeup water under nominal operation (i.e. no consideration of contingency needs), on a daily basis. Contingency issues are briefly discussed with respect to impacts on makeup water storage (shipped tanks versus storage in prepackaged food). The Dual Lander Transit Mission was selected for study because it has been considered by the Johnson Space Center Exploration Office in enough detail to define a reasonable set of scenario options for nominal system operation and contingencies. This study also illustrates the concept that there are multiple, reasonable life support system scenarios for any one particular mission. Thus, the need for a particular commodity can depend upon many variables in the system. In this study, we examine the need for makeup water as it depends upon the configuration of the rest of the life support system.

  9. Linear stochastic differential equations on the dual of a countably Hilbert nuclear space with applications to neurophysiology. Technical report, September 1984-August 1985

    SciTech Connect

    Christensen, S.K.

    1985-06-01

    Properties of the Ornstein-Uhlenbeck on the dual of a nuclear space are derived; stationarity and existence of unique invariant measure is proved, Radon-Nikodym derivative exhibited and the OU process is investigated for flicker noise. Existence and uniqueness of solutions to linear stochastic differential equations on the dual of a nuclear spaces established, and general conditions for the weak convergence on Skorohod space of solutions are given. Moreover, solutions are shown to be CADLAG semimartingales (for appropriate initial conditions). The results are applicable to solving stochastic partial differential equations. Finally, the results are applied to giving a rigorous representation and solutions of models in neurophysiology as well as to deriving explicit results for the weak convergence of these solutions.

  10. Dual LC-MS platform for high-throughput proteome analysis.

    PubMed

    Orton, Dennis J; Wall, Mark J; Doucette, Alan A

    2013-12-01

    We describe a dual-column interface for parallel chromatography to improve throughput during LC-MS experimentation. The system employs a high-voltage switch to operate two capillary column/nanospray emitters fixed at the MS orifice. Sequentially loading one column while operating the second nearly doubles the LC-MS duty cycle. Given the innate run-to-run variation of a nanospray LC-MS (12% RSD peak area; 2% retention time), the intercolumn variability of the platform showed no meaningful difference for proteome analysis, with equal numbers of proteins and peptides identified per column. Applied to GeLC analysis of an E. coli extract, throughput was increased using one of three methods: doubling the number of replicates, increasing the LC gradient length, or sectioning the gel into twice as many fractions. Each method increased the total number of identifications as well as detection throughput (number of peptides/proteins identified per hour). The greatest improvement was achieved by doubling the number of gel slices (10 vs 5). Analysis on the dual column platform provided a 26% increase in peptides identified per hour (24% proteins). This translates into ~50% more total proteins and peptides identified in the experiment using the dual LC-MS platform. PMID:24090060

  11. SOSPAC- SOLAR SPACE POWER ANALYSIS CODE

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K.

    1994-01-01

    The Solar Space Power Analysis Code, SOSPAC, was developed to examine the solar thermal and photovoltaic power generation options available for a satellite or spacecraft in low earth orbit. SOSPAC is a preliminary systems analysis tool and enables the engineer to compare the areas, weights, and costs of several candidate electric and thermal power systems. The configurations studied include photovoltaic arrays and parabolic dish systems to produce electricity only, and in various combinations to provide both thermal and electric power. SOSPAC has been used for comparison and parametric studies of proposed power systems for the NASA Space Station. The initial requirements are projected to be about 40 kW of electrical power, and a similar amount of thermal power with temperatures above 1000 degrees Centigrade. For objects in low earth orbit, the aerodynamic drag caused by suitably large photovoltaic arrays is very substantial. Smaller parabolic dishes can provide thermal energy at a collection efficiency of about 80%, but at increased cost. SOSPAC allows an analysis of cost and performance factors of five hybrid power generating systems. Input includes electrical and thermal power requirements, sun and shade durations for the satellite, and unit weight and cost for subsystems and components. Performance equations of the five configurations are derived, and the output tabulates total weights of the power plant assemblies, area of the arrays, efficiencies, and costs. SOSPAC is written in FORTRAN IV for batch execution and has been implemented on an IBM PC computer operating under DOS with a central memory requirement of approximately 60K of 8 bit bytes. This program was developed in 1985.

  12. IMAGE ANALYSIS ALGORITHMS FOR DUAL MODE IMAGING SYSTEMS

    SciTech Connect

    Robinson, Sean M.; Jarman, Kenneth D.; Miller, Erin A.; Misner, Alex C.; Myjak, Mitchell J.; Pitts, W. Karl; Seifert, Allen; Seifert, Carolyn E.; Woodring, Mitchell L.

    2010-06-11

    The level of detail discernable in imaging techniques has generally excluded them from consideration as verification tools in inspection regimes where information barriers are mandatory. However, if a balance can be struck between sufficient information barriers and feature extraction to verify or identify objects of interest, imaging may significantly advance verification efforts. This paper describes the development of combined active (conventional) radiography and passive (auto) radiography techniques for imaging sensitive items assuming that comparison images cannot be furnished. Three image analysis algorithms are presented, each of which reduces full image information to non-sensitive feature information and ultimately is intended to provide only a yes/no response verifying features present in the image. These algorithms are evaluated on both their technical performance in image analysis and their application with or without an explicitly constructed information barrier. The first algorithm reduces images to non-invertible pixel intensity histograms, retaining only summary information about the image that can be used in template comparisons. This one-way transform is sufficient to discriminate between different image structures (in terms of area and density) without revealing unnecessary specificity. The second algorithm estimates the attenuation cross-section of objects of known shape based on transition characteristics around the edge of the object’s image. The third algorithm compares the radiography image with the passive image to discriminate dense, radioactive material from point sources or inactive dense material. By comparing two images and reporting only a single statistic from the combination thereof, this algorithm can operate entirely behind an information barrier stage. Together with knowledge of the radiography system, the use of these algorithms in combination can be used to improve verification capability to inspection regimes and improve

  13. Pulse-modulated dual-gas control subsystem for space cabin atmosphere

    NASA Technical Reports Server (NTRS)

    Jackson, J. K.

    1974-01-01

    An atmosphere control subsystem (ACS) was developed for use in a closed manned cabin, such as the Space Shuttle Orbiter. This subsystem uses the Perkin Elmer mass spectrometer for continuous measurement of major atmospheric constituents (H2, H2O, N2, O2, and CO2). The O2 and N2 analog signals are used as inputs to the controller, which produces a pulse-frequency-modulated output to operate the N2 gas admission solenoid valve and an on-off signal to operate the O2 valve. The proportional controller characteristic results in improved control accuracy as compared with previously used on-off controllers having significant dead-band. A 60-day evaluation test was performed on the ACS during which operation was measured at various values of control setpoint and simulated cabin leakage.

  14. Single- and dual-carrier microwave noise abatement in the deep space network. [microwave antennas

    NASA Technical Reports Server (NTRS)

    Bathker, D. A.; Brown, D. W.; Petty, S. M.

    1975-01-01

    The NASA/JPL Deep Space Network (DSN) microwave ground antenna systems are presented which simultaneously uplink very high power S-band signals while receiving very low level S- and X-band downlinks. Tertiary mechanisms associated with elements give rise to self-interference in the forms of broadband noise burst and coherent intermodulation products. A long-term program to reduce or eliminate both forms of interference is described in detail. Two DSN antennas were subjected to extensive interference testing and practical cleanup program; the initial performance, modification details, and final performance achieved at several planned stages are discussed. Test equipment and field procedures found useful in locating interference sources are discussed. Practices deemed necessary for interference-free operations in the DSN are described. Much of the specific information given is expected to be easily generalized for application in a variety of similar installations. Recommendations for future investigations and individual element design are given.

  15. Comparison of Procedures for Dual and Triple Closely Spaced Parallel Runways

    NASA Technical Reports Server (NTRS)

    Verma, Savita; Ballinger, Deborah; Subramanian Shobana; Kozon, Thomas

    2012-01-01

    A human-in-the-loop high fidelity flight simulation experiment was conducted, which investigated and compared breakout procedures for Very Closely Spaced Parallel Approaches (VCSPA) with two and three runways. To understand the feasibility, usability and human factors of two and three runway VCSPA, data were collected and analyzed on the dependent variables of breakout cross track error and pilot workload. Independent variables included number of runways, cause of breakout and location of breakout. Results indicated larger cross track error and higher workload using three runways as compared to 2-runway operations. Significant interaction effects involving breakout cause and breakout location were also observed. Across all conditions, cross track error values showed high levels of breakout trajectory accuracy and pilot workload remained manageable. Results suggest possible avenues of future adaptation for adopting these procedures (e.g., pilot training), while also showing potential promise of the concept.

  16. On achieving sufficient dual station range accuracy for deep space navigation at zero declination

    NASA Technical Reports Server (NTRS)

    Siegel, H. L.; Christensen, C. S.; Green, D. W.; Winn, F. B.

    1977-01-01

    Since the Voyager Mission will encounter Saturn at a time when the planet will be nearly in the earth's equatorial plane, earth-based orbit determination will be more difficult than usual because of the so-called zero-declination singularity associated with conventional radiometric observations. Simulation studies show that in order to meet the required delivery accuracy at Saturn, a relative range measurement between the Goldstone and Canberra Deep Space Stations must be accurate to 4.5 times the square root of two meters. Topics discussed include the nature of error sources, the methodology and technology required for calibration, the verification process concerning the nearly simultaneous range capability, a description of the ranging system, and tracking strategy.

  17. Runoff Analysis Considering Orographical Features Using Dual Polarization Radar Rainfall

    NASA Astrophysics Data System (ADS)

    Noh, Hui-seong; Shin, Hyun-seok; Kang, Na-rae; Lee, Choong-Ke; Kim, Hung-soo

    2013-04-01

    Recently, the necessity for rainfall estimation and forecasting using the radar is being highlighted, due to the frequent occurrence of torrential rainfall resulting from abnormal changes of weather. Radar rainfall data represents temporal and spatial distributions properly and replace the existing rain gauge networks. It is also frequently applied in many hydrologic field researches. However, the radar rainfall data has an accuracy limitation since it estimates rainfall, by monitoring clouds and precipitation particles formed around the surface of the earth(1.5-3km above the surface) or the atmosphere. In a condition like Korea where nearly 70% of the land is covered by mountainous areas, there are lots of restrictions to use rainfall radar, because of the occurrence of beam blocking areas by topography. This study is aiming at analyzing runoff and examining the applicability of (R(Z), R(ZDR) and R(KDP)) provided by the Han River Flood Control Office(HRFCO) based on the basin elevation of Nakdong river watershed. For this purpose, the amount of radar rainfall of each rainfall event was estimated according to three sub-basins of Nakdong river watershed with the average basin elevation above 400m which are Namgang dam, Andong dam and Hapcheon dam and also another three sub-basins with the average basin elevation below 150m which are Waegwan, Changryeong and Goryeong. After runoff analysis using a distribution model, Vflo model, the results were reviewed and compared with the observed runoff. This study estimated the rainfall by using the radar-rainfall transform formulas, (R(Z), R(Z,ZDR) and R(Z,ZDR,KDP) for four stormwater events and compared the results with the point rainfall of the rain gauge. As the result, it was overestimated or underestimated, depending on rainfall events. Also, calculation indicates that the values from R(Z,ZDR) and R(Z,ZDR,KDP) relatively showed the most similar results. Moreover the runoff analysis using the estimated radar rainfall is

  18. Dual Parallel Liquid Chromatography with Dual Mass Spectrometry (LC2/MS2) for a Total Lipid Analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Total lipid extracts containing both polar and non-polar lipids were separated using two liquid chromatographic systems joined together using a column-switching valve. Detection was accomplished using mass spectrometers attached to each of the two liquid chromatographic systems, for a dual liquid c...

  19. James Webb Space Telescope Orbit Determination Analysis

    NASA Technical Reports Server (NTRS)

    Yoon, Sungpil; Rosales, Jose; Richon, Karen

    2014-01-01

    The James Webb Space Telescope (JWST) is designed to study and answer fundamental astrophysical questions from an orbit about the Sun-Earth/Moon L2 libration point, 1.5 million km away from Earth. This paper describes the results of an orbit determination (OD) analysis of the JWST mission emphasizing the challenges specific to this mission in various mission phases. Three mid-course correction (MCC) maneuvers during launch and early orbit phase and transfer orbit phase are required for the spacecraft to reach L2. These three MCC maneuvers are MCC-1a at Launch+12 hours, MCC-1b at L+2.5 days and MCC-2 at L+30 days. Accurate OD solutions are needed to support MCC maneuver planning. A preliminary analysis shows that OD performance with the given assumptions is adequate to support MCC maneuver planning. During the nominal science operations phase, the mission requires better than 2 cm/sec velocity estimation performance to support stationkeeping maneuver planning. The major challenge to accurate JWST OD during the nominal science phase results from the unusually large solar radiation pressure force acting on the huge sunshield. Other challenges are stationkeeping maneuvers at 21-day intervals to keep JWST in orbit around L2, frequent attitude reorientations to align the JWST telescope with its targets and frequent maneuvers to unload momentum accumulated in the reaction wheels. Monte Carlo analysis shows that the proposed OD approach can produce solutions that meet the mission requirements.

  20. Space Station resource node flow field analysis

    NASA Technical Reports Server (NTRS)

    Kania, Lee; Kumar, Ganesh; Mcconnaughey, Paul

    1991-01-01

    An analysis of the flow field within the Space Station Freedom resource node with operational intermodule ventilation and temperature/humidity control ventilation systems has been conducted. The INS3D code, an incompressible, steady-state Navier-Stokes solver has been used to assess the design of the ventilation system via quantification of the level of fluid mixing and identification of 'dead air' regions and short-circuit ventilation. Numerical results indicate significant short-circuit ventilation in the forward and midsections of the node and insufficient fluid mixing is found to exist in the aft node section. These results as well as results from a solution grid dependence study are presented.

  1. Analysis method and principle of dual-mode electro-mechanical variable transmission program

    NASA Astrophysics Data System (ADS)

    Li, Hongcai; Yan, Qingdong; Xiang, Changle; Wang, Weida

    2012-05-01

    Automotive industry, as an important pillar of the national economy, has been rapidly developing in recent years. But proplems such as energy comsumption and environmental pollution are posed at the same time. Electro-mechanical variable transmission system is considered one of avilable workarounds. It is brought forward a kind of design methods of dual-mode electro-mechanical variable transmission system rotational speed characteristics and dual-mode drive diagrams. With the motor operating behavior of running in four quadrants and the speed characteristics of the simple internal and external meshing single planetary gear train, four kinds of dual-mode electro-mechanical transmission system scheme are designed. And the velocity, torque and power characteristics of one of the programs are analyzed. The magnitude of the electric split-flow power is an important factor which influences the system performance, so in the parameters matching design, it needs to reduce the power needs under the first mode of the motor. The motor, output rotational speed range and the position of the mode switching point have relationships with the characteristics design of the planetary gear set. The analysis method is to provide a reference for hybrid vehicles' design. As the involved rotational speed and torque relationships are the natural contact of every part of transmission system, a theory basis of system program and performance analysis is provided.

  2. Queuing model analysis of the Fujitsu VP2000 with dual scalar architecture

    SciTech Connect

    Ishiguro, M. )

    1991-01-01

    This paper reports on a queuing model analysis which is given for the performance evaluation of a dual scalar processor (DSP), which is composed to two scalar units and one vector unit. The performance evaluation is the three different processor models with equivalent hardware capacity: homogeneous DSP (DSP1), heterogeneous DSP (DSP2), and multiprocessor (MP), with particular attention given to the case of short vector lengths. It is found that the performance of DSP1 is preferable to that of MP for most actual workloads, and in particular for the work-load of the Japan Atomic Energy Research Institute. The effect of the dual scalar capacity, that is, of attaching a secondary scalar unit, is also investigated. It is shown that the throughput of DSP1 is about 1.8 times that of the uniprocessor, for a vectorization ratio of 90%.

  3. Dynamics analysis of microsphere in a dual-beam fiber-optic trap with transverse offset.

    PubMed

    Chen, Xinlin; Xiao, Guangzong; Luo, Hui; Xiong, Wei; Yang, Kaiyong

    2016-04-01

    A comprehensive dynamics analysis of microsphere has been presented in a dual-beam fiber-optic trap with transverse offset. As the offset distance between two counterpropagating beams increases, the motion type of the microsphere starts with capture, then spiral motion, then orbital rotation, and ends with escape. We analyze the transformation process and mechanism of the four motion types based on ray optics approximation. Dynamic simulations show that the existence of critical offset distances at which different motion types transform. The result is an important step toward explaining physical phenomena in a dual-beam fiber-optic trap with transverse offset, and is generally applicable to achieving controllable motions of microspheres in integrated systems, such as microfluidic systems and lab-on-a-chip systems. PMID:27137046

  4. Analysis of dual-mode lasing characteristics in a 1310-nm optically injected quantum dot distributed feedback laser

    NASA Astrophysics Data System (ADS)

    Raghunathan, R.; Olinger, J.; Hurtado, A.; Grillot, F.; Kovanis, V.; Lester, L. F.

    2015-03-01

    Recent work has shown the Quantum Dot (QD) material system to be well-suited to support dual-mode lasing. In particular, optical injection from a master laser (ML) into the residual Fabry-Perot (FP) modes of a 1310 nm Quantum Dot Distributed Feedback (QD-DFB) laser has been recently demonstrated to offer a highly reliable platform for stable dual-mode lasing operation. External controls on the ML, such as operating temperature and bias current, can be used to precisely adjust the spacing between the two lasing modes. This tunability of modeseparation is very promising for a range of applications requiring the generation of microwave, millimeter wave and terahertz signals. Considering the versatility and utility of such a scheme, it is imperative to acquire a deeper understanding of the factors that influence the dual-mode lasing process, in order to optimize performance. Toward this end, this paper seeks to further our understanding of the optically-injected dual-mode lasing mechanism. For fixed values of optical power injected into each FP residual mode and wavelength detuning, the dual-mode lasing characteristics are analyzed with regard to important system parameters such as the position and the intensity of the injected residual mode (relative to the Bragg and the other residual FP modes of the device) for two similarly-fabricated QD-DFBs. Results indicate that for dual mode lasing spaced less than 5 nm apart, the relative intensity of the injected FP mode and intracavity noise levels are critical factors in determining dual mode lasing behavior. Insight into the dual-mode lasing characteristics could provide an important design guideline for the master and QD-DFB slave laser cavities.

  5. Multidisciplinary capability for analysis of the dynamics and control of flexible space structures

    NASA Technical Reports Server (NTRS)

    Cooper, P. A.; Lake, M. S.; Young, J. W.; Sutter, T. R.

    1986-01-01

    The paper describes a computerized data distribution capability, IMAT, in place at the NASA Langley Research Center for the multidisciplinary analysis of the dynamics and control of large flexible space structures. The paper includes results obtained in using IMAT to investigate the influence of the structural response of the space station framework on the control of a 300kw class, solar-dynamic-powered, dual-keel space station during an orbital reboost maneuver. The method of control, using an unfiltered proportional-plus-differential control law, led to a stable control system even with local flexible response measured at the control sensor location included as a part of the control error signal. The flexible response at the outboard solar dynamic system sun-line axis was close to the maximum rotation allowed for efficient operation; thus, active local control of each solar dynamic system may be necessary to limit sun-line axis rotations effectively during a reboost maneuver.

  6. An integrated time-of-flight versus residual energy subsystem for a compact dual ion composition experiment for space plasmas

    SciTech Connect

    Desai, M. I.; McComas, D. J.; Allegrini, F.; Livi, S. A.; Ogasawara, K.; Ebert, R. W.; Weidner, S. E.; Alexander, N.

    2015-05-15

    We have developed a novel concept for a Compact Dual Ion Composition Experiment (CoDICE) that simultaneously provides high quality plasma and energetic ion composition measurements over 6 decades in ion energy in a wide variety of space plasma environments. CoDICE measures the two critical ion populations in space plasmas: (1) mass and ionic charge state composition and 3D velocity and angular distributions of ∼10 eV/q–40 keV/q plasma ions—CoDICE-Lo and (2) mass composition, energy spectra, and angular distributions of ∼30 keV–10 MeV energetic ions—CoDICE-Hi. CoDICE uses a common, integrated Time-of-Flight (TOF) versus residual energy (E) subsystem for measuring the two distinct ion populations. This paper describes the CoDICE design concept, and presents results of the laboratory tests of the TOF portion of the TOF vs. E subsystem, focusing specifically on (1) investigation of spill-over and contamination rates on the start and stop microchannel plate (MCP) anodes vs. secondary electron steering and focusing voltages, scanned around their corresponding model-optimized values, (2) TOF measurements and resolution and angular resolution, and (3) cross-contamination of the start and stop MCPs’ singles rates from CoDICE-Lo and -Hi, and (4) energy resolution of avalanche photodiodes near the lower end of the CoDICE-Lo energy range. We also discuss physical effects that could impact the performance of the TOF vs. E subsystem in a flight instrument. Finally, we discuss advantages of the CoDICE design concept by comparing with capabilities and resources of existing flight instruments.

  7. An integrated time-of-flight versus residual energy subsystem for a compact dual ion composition experiment for space plasmas

    NASA Astrophysics Data System (ADS)

    Desai, M. I.; Ogasawara, K.; Ebert, R. W.; McComas, D. J.; Allegrini, F.; Weidner, S. E.; Alexander, N.; Livi, S. A.

    2015-05-01

    We have developed a novel concept for a Compact Dual Ion Composition Experiment (CoDICE) that simultaneously provides high quality plasma and energetic ion composition measurements over 6 decades in ion energy in a wide variety of space plasma environments. CoDICE measures the two critical ion populations in space plasmas: (1) mass and ionic charge state composition and 3D velocity and angular distributions of ˜10 eV/q-40 keV/q plasma ions—CoDICE-Lo and (2) mass composition, energy spectra, and angular distributions of ˜30 keV-10 MeV energetic ions—CoDICE-Hi. CoDICE uses a common, integrated Time-of-Flight (TOF) versus residual energy (E) subsystem for measuring the two distinct ion populations. This paper describes the CoDICE design concept, and presents results of the laboratory tests of the TOF portion of the TOF vs. E subsystem, focusing specifically on (1) investigation of spill-over and contamination rates on the start and stop microchannel plate (MCP) anodes vs. secondary electron steering and focusing voltages, scanned around their corresponding model-optimized values, (2) TOF measurements and resolution and angular resolution, and (3) cross-contamination of the start and stop MCPs' singles rates from CoDICE-Lo and -Hi, and (4) energy resolution of avalanche photodiodes near the lower end of the CoDICE-Lo energy range. We also discuss physical effects that could impact the performance of the TOF vs. E subsystem in a flight instrument. Finally, we discuss advantages of the CoDICE design concept by comparing with capabilities and resources of existing flight instruments.

  8. Evaluation of dual multi-mission space exploration vehicle operations during simulated planetary surface exploration

    NASA Astrophysics Data System (ADS)

    Abercromby, Andrew F. J.; Gernhardt, Michael L.; Jadwick, Jennifer

    2013-10-01

    IntroductionA pair of small pressurized rovers (multi-mission space exploration vehicles, or MMSEVs) is at the center of the Global Point-of-Departure architecture for future human lunar exploration. Simultaneous operation of multiple crewed surface assets should maximize productive crew time, minimize overhead, and preserve contingency return paths. MethodsA 14-day mission simulation was conducted in the Arizona desert as part of NASA's 2010 Desert Research and Technology Studies (DRATS) field test. The simulation involved two MMSEV earth-gravity prototypes performing geological exploration under varied operational modes affecting both the extent to which the MMSEVs must maintain real-time communications with the mission control center (Continuous [CC] versus Twice-a-Day [2/D]) and their proximity to each other (Lead-and-Follow [L&F] versus Divide-and-Conquer [D&C]). As part of a minimalist lunar architecture, no communication relay satellites were assumed. Two-person crews (an astronaut and a field geologist) operated each MMSEV, day and night, throughout the entire 14-day mission, only leaving via the suit ports to perform simulated extravehicular activities. Metrics and qualitative observations enabled evaluation of the extent to which the operating modes affected productivity and scientific data quality (SDQ). Results and discussionSDQ was greater during CC mode than during 2/D mode; metrics showed a marginal increase while qualitative assessments suggested a practically significant difference. For the communications architecture evaluated, significantly more crew time (14% per day) was required to maintain communications during D&C than during L&F (5%) or 2/D (2%), increasing the time required to complete all traverse objectives. Situational awareness of the other vehicle's location, activities, and contingency return constraints were qualitatively enhanced during L&F and 2/D modes due to line-of-sight and direct MMSEV-to-MMSEV communication. Future testing

  9. Evaluation of Thermo-Mechanical Stability of COTS Dual-Axis MEMS Accelerometers for Space Applications

    NASA Technical Reports Server (NTRS)

    Sharma, Ashok K.; Teverovksy, Alexander; Day, John H. (Technical Monitor)

    2000-01-01

    Microelectromechanical systems in MEMS is one of the fastest growing technologies in microelectronics, and is of great interest for military and aerospace applications. Accelerometers are the earliest and most developed representatives of MEMS. First demonstrated in 1979, micromachined accelerometers were used in automobile industry for air bag crash- sensing applications since 1990. In 1999, N4EMS accelerometers were used in NASA-JPL Mars Microprobe. The most developed accelerometers for airbag crash- sensing are rated for a full range of +/- 50 G. The range of sensitivity for accelerometers required for military or aerospace applications is much larger, varying from 20,000 G (to measure acceleration during gun and ballistic munition launches), and to 10(exp -6) G, when used as guidance sensors (to measure attitude and position of a spacecraft). The presence of moving parts on the surface of chip is specific to MEMS, and particularly, to accelerometers. This characteristic brings new reliability issues to micromachined accelerometers, including cyclic fatigue cracking of polysilicon cantilevers and springs, mechanical stresses that are caused by packaging and contamination in the internal cavity of the package. Studies of fatigue cracks initiation and growth in polysilicon showed that the fatigue damage may influence MEMS device performance, and the presence of water vapor significantly enhances crack initiation and growth. Environmentally induced failures, particularly, failures due to thermal cycling and mechanical shock are considered as one of major reliability concerns in MEMS. These environmental conditions are also critical for space applications of the parts. For example, the Mars pathfinder mission had experienced 80 mechanical shock events during the pyrotechnic separation processes.

  10. Quantitative material analysis by dual-energy computed tomography for industrial NDT applications

    NASA Astrophysics Data System (ADS)

    Nachtrab, F.; Weis, S.; Keßling, P.; Sukowski, F.; Haßler, U.; Fuchs, T.; Uhlmann, N.; Hanke, R.

    2011-05-01

    Dual-energy computed tomography (DECT) is an established method in the field of medical CT to obtain quantitative information on a material of interest instead of mean attenuation coefficients only. In the field of industrial X-ray imaging dual-energy techniques have been used to solve special problems on a case-by-case basis rather than as a standard tool. Our goal is to develop an easy-to-use dual-energy solution that can be handled by the average industrial operator without the need for a specialist. We are aiming at providing dual-energy CT as a measurement tool for those cases where qualitative images are not enough and one needs additional quantitative information (e.g. mass density ρ and atomic number Z) about the sample at hand. Our solution is based on an algorithm proposed by Heismann et al. (2003) [1] for application in medical CT . As input data this algorithm needs two CT data sets, one with low (LE) and one with high effective energy (HE). A first order linearization is applied to the raw data, and two volumes are reconstructed thereafter. The dual-energy analysis is done voxel by voxel, using a pre-calculated function F(Z) that implies the parameters of the low and high energy measurement (such as tube voltage, filtration and detector sensitivity). As a result, two volume data sets are obtained, one providing information about the mass density ρ in each voxel, the other providing the effective atomic number Z of the material therein. One main difference between medical and industrial CT is that the range of materials that can be contained in a sample is much wider and can cover the whole range of elements, from hydrogen to uranium. Heismann's algorithm is limited to the range of elements Z=1-30, because for Z>30 the function F(Z) as given by Heismann is not a bijective function anymore. While this still seems very suitable for medical application, it is not enough to cover the complete range of industrial applications. We therefore investigated the

  11. WHB/WTB SPACE PROGRAM ANALYSIS FOR SITE RECOMMENDATION

    SciTech Connect

    W.D. Lindholm

    2000-05-25

    The purpose of this analysis is to identify and evaluate the functional space and spatial relationship requirements for the two main nuclear buildings, the Waste Handling Building (WHB) and the Waste Treatment Building (WTB), which are part of the Repository Surface Facilities. This analysis is consistent with the Development Plan for ''WHB/WTB Space Program Analysis for Site Recommendation'' (CRWMS M&O 2000r), which concentrates on the primary, primary support, facility support, and miscellaneous building support areas located in the WHB and WTB. The development plan was completed in accordance with AP-2.134, ''Technical Product Development Planning''. The objective and scope of this analysis is to develop a set of spatial parameters (e.g., square footage, room heights, etc.) and layout requirements (e.g., adjacency and access/circulation requirements, etc.) from which preliminary building floor plans are developed and presented as figures. The resulting figures will provide information to support the Site Recommendation and the total system life cycle cost. This analysis uses the Viability Assessment (VA) ''Surface Nuclear Facilities Space Program Analysis'' (SPA) (CRWMS M&O 1997c) as the baseline reference document and further develops the functional requirements based on Project-directed changes, including incorporation of a new design basis waste stream and the applicable elements of Enhanced Design Alternative (EDA)-II, as identified in the ''License Application Design Selection Report'' (CRWMS M&O 1999e), which followed the initial SPA (baseline). The impacts of the EDA-II were almost entirely to the WHB. To meet the EDA-II thermal requirements, hotter fuel would be handled, therefore requiring a fuel-blending pool to be added to the WHB in order to age the hotter he1 at the repository and provide for commercial spent nuclear fuel (CSNF) blending. In addition to EDA-II recommendations, the waste stream was modified, including the elimination of approximately

  12. Simulation of Space-borne Radar Observation from High Resolution Cloud Model - for GPM Dual frequency Precipitation Radar -

    NASA Astrophysics Data System (ADS)

    Kim, H.; Meneghini, R.; Jones, J.; Liao, L.

    2011-12-01

    A comprehensive space-borne radar simulator has been developed to support active microwave sensor satellite missions. The two major objectives of this study are: 1) to develop a radar simulator optimized for the Dual-frequency Precipitation Radar (KuPR and KaPR) on the Global Precipitation Measurement Mission satellite (GPM-DPR) and 2) to generate the synthetic test datasets for DPR algorithm development. This simulator consists of two modules: a DPR scanning configuration module and a forward module that generates atmospheric and surface radar observations. To generate realistic DPR test data, the scanning configuration module specifies the technical characteristics of DPR sensor and emulates the scanning geometry of the DPR with a inner swath of about 120 km, which contains matched-beam data from both frequencies, and an outer swath from 120 to 245 km over which only Ku-band data will be acquired. The second module is a forward model used to compute radar observables (reflectivity, attenuation and polarimetric variables) from input model variables including temperature, pressure and water content (rain water, cloud water, cloud ice, snow, graupel and water vapor) over the radar resolution volume. Presently, the input data to the simulator come from the Goddard Cumulus Ensemble (GCE) and Weather Research and Forecast (WRF) models where a constant mass density is assumed for each species with a particle size distribution given by an exponential distribution with fixed intercept parameter (N0) and a slope parameter (Λ) determined from the equivalent water content. Although the model data do not presently contain mixed phase hydrometeors, the Yokoyama-Tanaka melting model is used along with the Bruggeman effective dielectric constant to replace rain and snow particles, where both are present, with mixed phase particles while preserving the snow/water fraction. For testing one of the DPR retrieval algorithms, the Surface Reference Technique (SRT), the simulator uses

  13. James Webb Space Telescope Orbit Determination Analysis

    NASA Technical Reports Server (NTRS)

    Yoon, Sungpil; Rosales, Jose; Richon, Karen

    2014-01-01

    The James Webb Space Telescope (JWST) is designed to study and answer fundamental astrophysical questions from an orbit about the Sun-EarthMoon L2 libration point, 1.5 million km away from Earth. Three mid-course correction (MCC) maneuvers during launch and early orbit phase and transfer orbit phase are required for the spacecraft to reach L2. These three MCC maneuvers are MCC-1a at Launch+12 hours, MCC-1b at L+2.5 days and MCC-2 at L+30 days. Accurate orbit determination (OD) solutions are needed to support MCC maneuver planning. A preliminary analysis shows that OD performance with the given assumptions is adequate to support MCC maneuver planning. During the nominal science operations phase, the mission requires better than 2 cmsec velocity estimation performance to support stationkeeping maneuver planning. The major challenge to accurate JWST OD during the nominal science phase results from the unusually large solar radiation pressure force acting on the huge sunshield. Other challenges are stationkeeping maneuvers at 21-day intervals to keep JWST in orbit around L2, frequent attitude reorientations to align the JWST telescope with its targets and frequent maneuvers to unload momentum accumulated in the reaction wheels. Monte Carlo analysis shows that the proposed OD approach can produce solutions that meet the mission requirements.

  14. Endoscopic image analysis in semantic space.

    PubMed

    Kwitt, R; Vasconcelos, N; Rasiwasia, N; Uhl, A; Davis, B; Häfner, M; Wrba, F

    2012-10-01

    A novel approach to the design of a semantic, low-dimensional, encoding for endoscopic imagery is proposed. This encoding is based on recent advances in scene recognition, where semantic modeling of image content has gained considerable attention over the last decade. While the semantics of scenes are mainly comprised of environmental concepts such as vegetation, mountains or sky, the semantics of endoscopic imagery are medically relevant visual elements, such as polyps, special surface patterns, or vascular structures. The proposed semantic encoding differs from the representations commonly used in endoscopic image analysis (for medical decision support) in that it establishes a semantic space, where each coordinate axis has a clear human interpretation. It is also shown to establish a connection to Riemannian geometry, which enables principled solutions to a number of problems that arise in both physician training and clinical practice. This connection is exploited by leveraging results from information geometry to solve problems such as (1) recognition of important semantic concepts, (2) semantically-focused image browsing, and (3) estimation of the average-case semantic encoding for a collection of images that share a medically relevant visual detail. The approach can provide physicians with an easily interpretable, semantic encoding of visual content, upon which further decisions, or operations, can be naturally carried out. This is contrary to the prevalent practice in endoscopic image analysis for medical decision support, where image content is primarily captured by discriminative, high-dimensional, appearance features, which possess discriminative power but lack human interpretability. PMID:22717411

  15. Endoscopic Image Analysis in Semantic Space

    PubMed Central

    Kwitt, R.; Vasconcelos, N.; Rasiwasia, N.; Uhl, A.; Davis, B.; Häfner, M.; Wrba, F.

    2013-01-01

    A novel approach to the design of a semantic, low-dimensional, encoding for endoscopic imagery is proposed. This encoding is based on recent advances in scene recognition, where semantic modeling of image content has gained considerable attention over the last decade. While the semantics of scenes are mainly comprised of environmental concepts such as vegetation, mountains or sky, the semantics of endoscopic imagery are medically relevant visual elements, such as polyps, special surface patterns, or vascular structures. The proposed semantic encoding differs from the representations commonly used in endoscopic image analysis (for medical decision support) in that it establishes a semantic space, where each coordinate axis has a clear human interpretation. It is also shown to establish a connection to Riemannian geometry, which enables principled solutions to a number of problems that arise in both physician training and clinical practice. This connection is exploited by leveraging results from information geometry to solve problems such as 1) recognition of important semantic concepts, 2) semantically-focused image browsing, and 3) estimation of the average-case semantic encoding for a collection of images that share a medically relevant visual detail. The approach can provide physicians with an easily interpretable, semantic encoding of visual content, upon which further decisions, or operations, can be naturally carried out. This is contrary to the prevalent practice in endoscopic image analysis for medical decision support, where image content is primarily captured by discriminative, high-dimensional, appearance features, which possess discriminative power but lack human interpretability. PMID:22717411

  16. International Space Station Modal Correction Analysis

    NASA Technical Reports Server (NTRS)

    Fotz[atrocl. Lrostom; Grugoer. < ocjae; Laible, Michael; Sugavanam, Sujatha

    2012-01-01

    This paper summarizes the on-orbit modal test and the related modal analysis, model validation and correlation performed for the ISS Stage ULF4, DTF S4-1A, October 11,2010, GMT 284/06:13:00.00. The objective of this analysis is to validate and correlate analytical models with the intent to verify the ISS critical interface dynamic loads and improve fatigue life prediction. For the ISS configurations under consideration, on-orbit dynamic responses were collected with Russian vehicles attached and without the Orbiter attached to the ISS. ISS instrumentation systems that were used to collect the dynamic responses during the DTF S4-1A included the Internal Wireless Instrumentation System (IWIS), External Wireless Instrumentation System (EWIS), Structural Dynamic Measurement System (SDMS), Space Acceleration Measurement System (SAMS), Inertial Measurement Unit (IMU) and ISS External Cameras. Experimental modal analyses were performed on the measured data to extract modal parameters including frequency, damping and mode shape information. Correlation and comparisons between test and analytical modal parameters were performed to assess the accuracy of models for the ISS configuration under consideration. Based on the frequency comparisons, the accuracy of the mathematical models is assessed and model refinement recommendations are given. Section 2.0 of this report presents the math model used in the analysis. This section also describes the ISS configuration under consideration and summarizes the associated primary modes of interest along with the fundamental appendage modes. Section 3.0 discusses the details of the ISS Stage ULF4 DTF S4-1A test. Section 4.0 discusses the on-orbit instrumentation systems that were used in the collection of the data analyzed in this paper. The modal analysis approach and results used in the analysis of the collected data are summarized in Section 5.0. The model correlation and validation effort is reported in Section 6.0. Conclusions and

  17. Microchemical Analysis Of Space Operation Debris

    NASA Technical Reports Server (NTRS)

    Cummings, Virginia J.; Kim, Hae Soo

    1995-01-01

    Report discusses techniques used in analyzing debris relative to space shuttle operations. Debris collected from space shuttle, expendable launch vehicles, payloads carried by space shuttle, and payloads carried by expendable launch vehicles. Optical microscopy, scanning electron microscopy with energy-dispersive spectrometry, analytical electron microscopy with wavelength-dispersive spectrometry, and X-ray diffraction chosen as techniques used in examining samples of debris.

  18. Space construction system analysis. Part 2: Cost and programmatics

    NASA Technical Reports Server (NTRS)

    Vonflue, F. W.; Cooper, W.

    1980-01-01

    Cost and programmatic elements of the space construction systems analysis study are discussed. The programmatic aspects of the ETVP program define a comprehensive plan for the development of a space platform, the construction system, and the space shuttle operations/logistics requirements. The cost analysis identified significant items of cost on ETVP development, ground, and flight segments, and detailed the items of space construction equipment and operations.

  19. Antigen-antibody binding kinetics for biosensor applications. A dual-fractal analysis.

    PubMed

    Sadana, A; Suturia, M

    1997-01-01

    The diffusion-limited binding kinetics of antigen (or antibody) in solution to antibody (or antigen) immobilized on a biosensor surface is analyzed within a fractal framework. The fit obtained by a dual-fractal analysis is compared with that obtained from a single-fractal analysis. In some cases, the dual-fractal analysis provides an improved fit when compared with a single-fractal analysis. This was indicated by the regression analysis provided by Sigmaplot (San Rafael, CA). These examples are presented. It is of interest to note that the state of disorder (or the fractal dimension) and the binding rate coefficient both increase (or decrease, a single example is presented for this case) as the reaction progresses on the biosensor surface. For example, for the binding of monoclonal antibody MAb 49 in solution to surface-immobilized antigen, a 90.4% increase in the fractal dimension (Df1 to Df2) from 1.327 to 2.527 leads to an increase in the binding rate coefficient (k1 to k2) by a factor of 9.4 from 11.74 to 110.3. The different examples analyzed and presented together provide a means by which the antigen-antibody reactions may be better controlled by noting the magnitude of the changes in the fractal dimension and in the binding rate coefficient as the reaction progresses on the biosensor surface. PMID:9170257

  20. A Priori Analysis of Flamelet-Based Modeling for a Dual-Mode Scramjet Combustor

    NASA Technical Reports Server (NTRS)

    Quinlan, Jesse R.; McDaniel, James C.; Drozda, Tomasz G.; Lacaze, Guilhem; Oefelein, Joseph

    2014-01-01

    An a priori investigation of the applicability of flamelet-based combustion models to dual-mode scramjet combustion was performed utilizing Reynolds-averaged simulations (RAS). For this purpose, the HIFiRE Direct Connect Rig (HDCR) flowpath, fueled with a JP-7 fuel surrogate and operating in dual- and scram-mode was considered. The chemistry of the JP-7 fuel surrogate was modeled using a 22 species, 18-step chemical reaction mechanism. Simulation results were compared to experimentally-obtained, time-averaged, wall pressure measurements to validate the RAS solutions. The analysis of the dual-mode operation of this flowpath showed regions of predominately non-premixed, high-Damkohler number, combustion. Regions of premixed combustion were also present but associated with only a small fraction of the total heat-release in the flow. This is in contrast to the scram-mode operation, where a comparable amount of heat is released from non-premixed and premixed combustion modes. Representative flamelet boundary conditions were estimated by analyzing probability density functions for temperature and pressure for pure fuel and oxidizer conditions. The results of the present study reveal the potential for a flamelet model to accurately model the combustion processes in the HDCR and likely other high-speed flowpaths of engineering interest.

  1. Performance requirements analysis for payload delivery from a space station

    NASA Technical Reports Server (NTRS)

    Friedlander, A. L.; Soldner, J. K.; Bell, J. (Editor); Ricks, G. W.; Kincade, R. E.; Deatkins, D.; Reynolds, R.; Nader, B. A.; Hill, O.; Babb, G. R.

    1983-01-01

    Operations conducted from a space station in low Earth orbit which have different constraints and opportunities than those conducted from direct Earth launch were examined. While a space station relieves many size and performance constraints on the space shuttle, the space station's inertial orbit has different launch window constraints from those associated with customary Earth launches which reflect upon upper stage capability. A performance requirements analysis was developed to provide a reference source of parametric data, and specific case solutions and upper stage sizing trade to assist potential space station users and space station and upper stage developers assess the impacts of a space station on missions of interest.

  2. Modeling and Analysis of Space Based Transceivers

    NASA Technical Reports Server (NTRS)

    Moore, Michael S.; Price, Jeremy C.; Reinhart, Richard; Liebetreu, John; Kacpura, Tom J.

    2005-01-01

    This paper presents the tool chain, methodology, and results of an on-going study being performed jointly by Space Communication Experts at NASA Glenn Research Center (GRC), General Dynamics C4 Systems (GD), and Southwest Research Institute (SwRI). The team is evaluating the applicability and tradeoffs concerning the use of Software Defined Radio (SDR) technologies for Space missions. The Space Telecommunications Radio Systems (STRS) project is developing an approach toward building SDR-based transceivers for space communications applications based on an accompanying software architecture that can be used to implement transceivers for NASA space missions. The study is assessing the overall cost and benefit of employing SDR technologies in general, and of developing a software architecture standard for its space SDR transceivers. The study is considering the cost and benefit of existing architectures, such as the Joint Tactical Radio Systems (JTRS) Software Communications Architecture (SCA), as well as potential new space-specific architectures.

  3. Improved Persistent Scatterer analysis using Amplitude Dispersion Index optimization of dual polarimetry data

    NASA Astrophysics Data System (ADS)

    Esmaeili, Mostafa; Motagh, Mahdi

    2016-07-01

    Time-series analysis of Synthetic Aperture Radar (SAR) data using the two techniques of Small BAseline Subset (SBAS) and Persistent Scatterer Interferometric SAR (PSInSAR) extends the capability of conventional interferometry technique for deformation monitoring and mitigating many of its limitations. Using dual/quad polarized data provides us with an additional source of information to improve further the capability of InSAR time-series analysis. In this paper we use dual-polarized data and combine the Amplitude Dispersion Index (ADI) optimization of pixels with phase stability criterion for PSInSAR analysis. ADI optimization is performed by using Simulated Annealing algorithm to increase the number of Persistent Scatterer Candidate (PSC). The phase stability of PSCs is then measured using their temporal coherence to select the final sets of pixels for deformation analysis. We evaluate the method for a dataset comprising of 17 dual polarization SAR data (HH/VV) acquired by TerraSAR-X data from July 2013 to January 2014 over a subsidence area in Iran and compare the effectiveness of the method for both agricultural and urban regions. The results reveal that using optimum scattering mechanism decreases the ADI values in urban and non-urban regions. As compared to single-pol data the use of optimized polarization increases initially the number of PSCs by about three times and improves the final PS density by about 50%, in particular in regions with high rate of deformation which suffer from losing phase stability over the time. The classification of PS pixels based on their optimum scattering mechanism revealed that the dominant scattering mechanism of the PS pixels in the urban area is double-bounce while for the non-urban regions (ground surfaces and farmlands) it is mostly single-bounce mechanism.

  4. Space Shuttle Columbia Aging Wiring Failure Analysis

    NASA Technical Reports Server (NTRS)

    McDaniels, Steven J.

    2005-01-01

    A Space Shuttle Columbia main engine controller 14 AWG wire short circuited during the launch of STS-93. Post-flight examination divulged that the wire had electrically arced against the head of a nearby bolt. More extensive inspection revealed additional damage to the subject wire, and to other wires as well from the mid-body of Columbia. The shorted wire was to have been constructed from nickel-plated copper conductors surrounded by the polyimide insulation Kapton, top-coated with an aromatic polyimide resin. The wires were analyzed via scanning electron microscope (SEM), energy dispersive X-Ray spectroscopy (EDX), and electron spectroscopy for chemical analysis (ESCA); differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) were performed on the polyimide. Exemplar testing under laboratory conditions was performed to replicate the mechanical damage characteristics evident on the failed wires. The exemplar testing included a step test, where, as the name implies, a person stepped on a simulated wire bundle that rested upon a bolt head. Likewise, a shear test that forced a bolt head and a torque tip against a wire was performed to attempt to damage the insulation and conductor. Additionally, a vibration test was performed to determine if a wire bundle would abrade when vibrated against the head of a bolt. Also, an abrasion test was undertaken to determine if the polyimide of the wire could be damaged by rubbing against convolex helical tubing. Finally, an impact test was performed to ascertain if the use of the tubing would protect the wire from the strike of a foreign object.

  5. Wind profiles for Space Shuttle loads analysis

    NASA Technical Reports Server (NTRS)

    Adelfang, S. I.

    1978-01-01

    The small scale wind velocity perturbations in vertical wind profiles at Cape Kennedy, Florida were analyzed in order to derive information for simulations of space shuttle ascent through the perturbed atmosphere. The available statistical data does not permit specification of various aspects of idealized singularities and wavelike perturbations with a reasonable degree of confidence. The information developed as a result of the analysis described in Section 3 of this report is suitable for the further development of idealized models. The term perturbation is used instead of the more common term, gust. According to the conventional approach, a gust profile is calculated by applying a high pass digital filter to a Jimsphere profile; all the speeds in the filtered profile are defined as gusts. The high pass filtered profile is defined as a residual profile and the maximum residual in the vicinity of a specified reference height is defined as the gust. Gusts defined in this manner represent the perturbation peaks. A detailed discussion of the calculation of residual profiles and gusts is given. The meteorological coordinate system, the data sample, and Jimsphere profiles are also described. Recommendations and conclusions are presented.

  6. Scan-less, line-field confocal microscopy by combination of wavelength/space conversion with dual optical comb

    NASA Astrophysics Data System (ADS)

    Yasui, Takeshi; Hase, Eiji; Miyamoto, Shuji; Hsieh, Yi-Da; Minamikawa, Takeo; Yamamoto, Hirotsugu

    2016-03-01

    Optical frequency comb (OFC) has attracted attentions for optical frequency metrology in visible and infrared regions because the mode-resolved OFC spectrum can be used as a precise frequency ruler due to both characteristics of broadband radiation and narrow-line CW radiation. Furthermore, the absolute accuracy of all frequency modes in OFC is secured by phase-locking a repetition frequency frep and a carrier-envelope-offset frequency fceo to a frequency standard. However, application fields of OFC other than optical frequency metrology are still undeveloped. One interesting aspect of OFC except for the frequency ruler is optical carrier having a huge number of discrete frequency channels because OFC is composed of a series of frequency spikes regularly separated by frep in the broad spectral range. If a certain quantity to be measured is encoded on each comb mode by dimensional conversion, a huge number of data for the measured quantity can be obtained from a single mode-resolved spectrum of OFC. In this paper, we encode the confocal microscopic line-image of a sample on the mode-resolved OFC spectrum by the dimensional conversion between wavelength and 1D-space. The resulting image-encoded OFC spectrum is acquired by an optical spectrum analyzer or dual comb spectrometer. Finally, the line image of the sample is decoded from the spectral amplitude of the mode-resolved OFC spectrum. The combination of OFC with the dimensional conversion enables to establish both confocal modality and line-field imaging under the scan-less condition.

  7. Phase analysis on dual-phase steel using band slope of electron backscatter diffraction pattern.

    PubMed

    Kang, Jun-Yun; Park, Seong-Jun; Moon, Man-Been

    2013-08-01

    A quantitative and automated phase analysis of dual-phase (DP) steel using electron backscatter diffraction (EBSD) was attempted. A ferrite-martensite DP microstructure was produced by intercritical annealing and quenching. An EBSD map of the microstructure was obtained and post-processed for phase discrimination. Band slope (BS), which was a measure of pattern quality, exhibited much stronger phase contrast than another conventional one, band contrast. Owing to high sensitivity to lattice defect and little orientation dependence, BS provided handiness in finding a threshold for phase discrimination. Its grain average gave a superior result on the discrimination and volume fraction measurement of the constituent phases in the DP steel. PMID:23920165

  8. Designing space vehicle shields for meteoroid protection - A new analysis

    NASA Technical Reports Server (NTRS)

    Swift, H. F.; Bamford, R.; Chen, R.

    1982-01-01

    A new analysis for designing dual-layer shields is presented which is based on energy and momentum conservation, fundamental electromagnetic radiation physics, and the observation of results of extensive experimental impact studies performed at relatively low velocities (near 7 km/s). An important finding is that most of the kinetic energy of a meteoroid striking a dual-layer shield is expended as radiation at the stagnation zone on the face plate of the underlying structure. Systematic procedures for evaluating the response of shield designs for a given impact threat are described. It is noted that similar applications of the analysis can be employed to support a mathematically rigorous procedure for optimum shield design.

  9. Economic analysis of crystal growth in space

    NASA Technical Reports Server (NTRS)

    Ulrich, D. R.; Chung, A. M.; Yan, C. S.; Mccreight, L. R.

    1972-01-01

    Many advanced electronic technologies and devices for the 1980's are based on sophisticated compound single crystals, i.e. ceramic oxides and compound semiconductors. Space processing of these electronic crystals with maximum perfection, purity, and size is suggested. No ecomonic or technical justification was found for the growth of silicon single crystals for solid state electronic devices in space.

  10. Analysis of space telescope data collection systems

    NASA Technical Reports Server (NTRS)

    Ingels, F. M.

    1984-01-01

    The Multiple Access (MA) communication link of the Space Telescope (ST) is described. An expected performance bit error rate is presented. The historical perspective and rationale behind the ESTL space shuttle end-to-end tests are given. The concatenated coding scheme using a convolutional encoder for the outer coder is developed. The ESTL end-to-end tests on the space shuttle communication link are described. Most important is how a concatenated coding system will perform. This is a go-no-go system with respect to received signal-to-noise ratio. A discussion of the verification requirements and Specification document is presented, and those sections that apply to Space Telescope data and communications system are discussed. The Space Telescope System consists of the Space Telescope Orbiting Observatory (ST), the Space Telescope Science Institute, and the Space Telescope Operation Control Center. The MA system consists of the ST, the return link from the ST via the Tracking and Delay Relay Satellite system to White Sands, and from White Sands via the Domestic Communications Satellite to the STOCC.

  11. Analysis of Space Coherent LIDAR Wind Mission

    NASA Technical Reports Server (NTRS)

    Spiers, Gary D.

    1997-01-01

    An evaluation of the performance of a coherent Doppler lidar proposed by a team comprising the NASA Marshall Space Flight Center, Lockheed Martin Space Company, University of Wisconsin and Los Alamos National Laboratory to NASA's Earth System Science Pathfinder (ESSP) program was performed. The design went through several iterations and only the performance of the final design is summarized here.

  12. Fault tree analysis of fire and explosion accidents for dual fuel (diesel/natural gas) ship engine rooms

    NASA Astrophysics Data System (ADS)

    Guan, Yifeng; Zhao, Jie; Shi, Tengfei; Zhu, Peipei

    2016-07-01

    In recent years, China's increased interest in environmental protection has led to a promotion of energy-efficient dual fuel (diesel/natural gas) ships in Chinese inland rivers. A natural gas as ship fuel may pose dangers of fire and explosion if a gas leak occurs. If explosions or fires occur in the engine rooms of a ship, heavy damage and losses will be incurred. In this paper, a fault tree model is presented that considers both fires and explosions in a dual fuel ship; in this model, dual fuel engine rooms are the top events. All the basic events along with the minimum cut sets are obtained through the analysis. The primary factors that affect accidents involving fires and explosions are determined by calculating the degree of structure importance of the basic events. According to these results, corresponding measures are proposed to ensure and improve the safety and reliability of Chinese inland dual fuel ships.

  13. Space Launch System Vibration Analysis Support

    NASA Technical Reports Server (NTRS)

    Johnson, Katie

    2016-01-01

    The ultimate goal for my efforts during this internship was to help prepare for the Space Launch System (SLS) integrated modal test (IMT) with Rodney Rocha. In 2018, the Structural Engineering Loads and Dynamics Team will have 10 days to perform the IMT on the SLS Integrated Launch Vehicle. After that 10 day period, we will have about two months to analyze the test data and determine whether the integrated vehicle modes/frequencies are adequate for launching the vehicle. Because of the time constraints, NASA must have newly developed post-test analysis methods proven well and with technical confidence before testing. NASA civil servants along with help from rotational interns are working with novel techniques developed and applied external to Johnson Space Center (JSC) to uncover issues in applying this technique to much larger scales than ever before. We intend to use modal decoupling methods to separate the entangled vibrations coming from the SLS and its support structure during the IMT. This new approach is still under development. The primary goal of my internship was to learn the basics of structural dynamics and physical vibrations. I was able to accomplish this by working on two experimental test set ups, the Simple Beam and TAURUS-T, and by doing some light analytical and post-processing work. Within the Simple Beam project, my role involves changing the data acquisition system, reconfiguration of the test set up, transducer calibration, data collection, data file recovery, and post-processing analysis. Within the TAURUS-T project, my duties included cataloging and removing the 30+ triaxial accelerometers, coordinating the removal of the structure from the current rolling cart to a sturdy billet for further testing, preparing the accelerometers for remounting, accurately calibrating, mounting, and mapping of all accelerometer channels, and some testing. Hammer and shaker tests will be performed to easily visualize mode shapes at low frequencies. Short

  14. Dual-slot antennas for microwave tissue heating: Parametric design analysis and experimental validation

    PubMed Central

    Brace, Christopher L.

    2011-01-01

    Purpose: Design and validate an efficient dual-slot coaxial microwave ablation antenna that produces an approximately spherical heating pattern to match the shape of most abdominal and pulmonary tumor targets.Methods: A dual-slot antenna geometry was utilized for this study. Permutations of the antenna geometry using proximal and distal slot widths from 1 to 10 mm separated by 1–20 mm were analyzed using finite-element electromagnetic simulations. From this series, the most optimal antenna geometry was selected using a two-term sigmoidal objective function to minimize antenna reflection coefficient and maximize the diameter-to-length aspect ratio of heat generation. Sensitivities to variations in tissue properties and insertion depth were also evaluated in numerical models. The most optimal dual-slot geometry of the parametric analysis was then fabricated from semirigid coaxial cable. Antenna reflection coefficients at various insertion depths were recorded in ex vivo bovine livers and compared to numerical results. Ablation zones were then created by applying 50 W for 2–10 min in simulations and ex vivo livers. Mean zone diameter, length, aspect ratio, and reflection coefficients before and after heating were then compared to a conventional monopole antenna using ANOVA with post-hoc t-tests. Statistical significance was indicated for P < 0.05.Results: Antenna performance was highly sensitive to dual-slot geometry. The best-performing designs utilized a proximal slot width of 1 mm, distal slot width of 4 mm ± 1 mm and separation of 8 mm ± 1 mm. These designs were characterized by an active choking mechanism that focused heating to the distal tip of the antenna. A dual-band resonance was observed in the most optimal design, with a minimum reflection coefficient of −20.9 dB at 2.45 and 1.25 GHz. Total operating bandwidth was greater than 1 GHz, but the desired heating pattern was achieved only near 2.45 GHz. As a result, antenna performance was

  15. Space tug economic analysis study. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    1972-01-01

    An economic analysis of space tug operations is presented. The space tug is defined as any liquid propulsion stage under 100,000 pounds propellant loading that is flown from the space shuttle cargo bay. Two classes of vehicles are the orbit injection stages and reusable space tugs. The vehicle configurations, propellant combinations, and operating modes used for the study are reported. The summary contains data on the study approach, results, conclusions, and recommendations.

  16. Receiver design, performance analysis, and evaluation for space-borne laser altimeters and space-to-space laser ranging systems

    NASA Technical Reports Server (NTRS)

    Davidson, Frederic M.; Sun, Xiaoli; Field, Christopher T.

    1994-01-01

    Accomplishments in the following areas of research are presented: receiver performance study of spaceborne laser altimeters and cloud and aerosol lidars; receiver performance analysis for space-to-space laser ranging systems; and receiver performance study for the Mars Environmental Survey (MESUR).

  17. Space tug economic analysis study. Volume 2: Tug concepts analysis. Part 2: Economic analysis

    NASA Technical Reports Server (NTRS)

    1972-01-01

    An economic analysis of space tug operations is presented. The subjects discussed are: (1) cost uncertainties, (2) scenario analysis, (3) economic sensitivities, (4) mixed integer programming formulation of the space tug problem, and (5) critical parameters in the evaluation of a public expenditure.

  18. Space Construction System Analysis. Part 2: Executive summary

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A detailed, end-to-end analysis of the activities, techniques, equipment and Shuttle provisions required to construct a reference project system is described. Included are: platform definition; construction analysis; cost and programmatics; and space construction experiments concepts.

  19. Dual-channel microcantilever heaters for volatile organic compound detection and mixture analysis

    NASA Astrophysics Data System (ADS)

    Jahangir, Ifat; Koley, Goutam

    2016-07-01

    We report on novel microcantilever heater sensors with separate AlGaN/GaN heterostructure based heater and sensor channels to perform advanced volatile organic compound (VOC) detection and mixture analysis. Operating without any surface functionalization or treatment, these microcantilevers utilize the strong surface polarization of AlGaN, as well as the unique heater and sensor channel geometries, to perform selective detection of analytes based on their latent heat of evaporation and molecular dipole moment over a wide concentration range with sub-ppm detection limit. The dual-channel microcantilevers have demonstrated much superior sensing behavior compared to the single-channel ones, with the capability to not only identify individual VOCs with much higher specificity, but also uniquely detect them in a generic multi-component mixture of VOCs. In addition, utilizing two different dual channel configurations and sensing modalities, we have been able to quantitatively determine individual analyte concentration in a VOC mixture. An algorithm for complete mixture analysis, with unique identification of components and accurate determination of their concentration, has been presented based on simultaneous operation of an array of these microcantilever heaters in multiple sensing modalities.

  20. Dual-channel microcantilever heaters for volatile organic compound detection and mixture analysis

    PubMed Central

    Jahangir, Ifat; Koley, Goutam

    2016-01-01

    We report on novel microcantilever heater sensors with separate AlGaN/GaN heterostructure based heater and sensor channels to perform advanced volatile organic compound (VOC) detection and mixture analysis. Operating without any surface functionalization or treatment, these microcantilevers utilize the strong surface polarization of AlGaN, as well as the unique heater and sensor channel geometries, to perform selective detection of analytes based on their latent heat of evaporation and molecular dipole moment over a wide concentration range with sub-ppm detection limit. The dual-channel microcantilevers have demonstrated much superior sensing behavior compared to the single-channel ones, with the capability to not only identify individual VOCs with much higher specificity, but also uniquely detect them in a generic multi-component mixture of VOCs. In addition, utilizing two different dual channel configurations and sensing modalities, we have been able to quantitatively determine individual analyte concentration in a VOC mixture. An algorithm for complete mixture analysis, with unique identification of components and accurate determination of their concentration, has been presented based on simultaneous operation of an array of these microcantilever heaters in multiple sensing modalities. PMID:27381318

  1. Preliminary benefit analysis of biological space processing

    NASA Technical Reports Server (NTRS)

    Perrine, J.

    1976-01-01

    The value of weightlessness in bioprocessing is assessed. The ecomonic benefits are assessed for space processing urokinase and human lymphocytes for treatment of end stage renal disease and thromboembolisms.

  2. System analysis of global space power problem

    NASA Astrophysics Data System (ADS)

    Latyshev, Leonid

    A brief discussion of Space Power System development problems is presented. Topics covered include the following: solar energy utilization; solar energy concentrators and receivers; solar electric power plants; thermonuclear electric power plants; energy transmission; and lunar bases.

  3. Space Station Program threat and vulnerability analysis

    NASA Technical Reports Server (NTRS)

    Van Meter, Steven D.; Veatch, John D.

    1987-01-01

    An examination has been made of the physical security of the Space Station Program at the Kennedy Space Center in a peacetime environment, in order to furnish facility personnel with threat/vulnerability information. A risk-management approach is used to prioritize threat-target combinations that are characterized in terms of 'insiders' and 'outsiders'. Potential targets were identified and analyzed with a view to their attractiveness to an adversary, as well as to the consequentiality of the resulting damage.

  4. Probabilistic structural analysis methods for space transportation propulsion systems

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Moore, N.; Anis, C.; Newell, J.; Nagpal, V.; Singhal, S.

    1991-01-01

    Information on probabilistic structural analysis methods for space propulsion systems is given in viewgraph form. Information is given on deterministic certification methods, probability of failure, component response analysis, stress responses for 2nd stage turbine blades, Space Shuttle Main Engine (SSME) structural durability, and program plans. .

  5. Space transfer concepts and analysis for exploration missions

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Covered here is the second phase of a broad scoped and systematic study of space transfer concepts for human lunar and Mars missions. The study addressed issues that were raised during Phase 1, developed generic Mars missions profile analysis data, and conducted preliminary analysis of the Mars in-space transportation requirements and implementation from the Stafford Committee Synthesis Report.

  6. Responsive space: Concept analysis and theoretical framework

    NASA Astrophysics Data System (ADS)

    Saleh, Joseph H.; Dubos, Gregory F.

    2009-08-01

    Customers' needs are dynamic and evolve in response to unfolding environmental uncertainties. The ability of a company or an industry to address these changing customers' needs in a timely and cost-effective way is a measure of its responsiveness. In the space industry, a systemic discrepancy exists between the time constants associated with the change of customers' needs, and the response time of the industry in delivering on-orbit solutions to these needs. There are important penalties associated with such delays, and space responsiveness is recognized as a strategic imperative in commercial competitive and military environments. In this paper, we provide a critical assessment of the literature on responsive space and introduce a new multi-disciplinary framework for thinking about and addressing issues of space responsiveness. Our framework advocates three levels of responsiveness: a global industry-wide responsiveness, a local stakeholder responsiveness, and an interactive or inter-stakeholder responsiveness. We introduce and motivate the use of "responsiveness maps" for multiple stakeholders. We then identify "levers of responsiveness": technical spacecraft- and launch-centric, as well as "soft" levers (e.g., acquisition policies) for improving the responsiveness of the space industry. Finally, we propose a series of research questions to aggressively tackle problems associated with space responsiveness.

  7. A study of rain estimation methods from space using dual-wavelength radar measurements at near-nadir incidence over ocean

    NASA Technical Reports Server (NTRS)

    Meneghini, R.; Kozu, T.; Kumagai, H.; Boncyk, W. C.

    1992-01-01

    A question arising from the recent interest in spaceborne weather radar is what methods can be used to estimate precipitation parameters from space. In this paper, dual-wavelength airborne radar data obtained from flights conducted during 1988 and 1989 are used to compare rain rates derived from backscattering and attenuation methods. To help interpret the results the surface reference methods are studied by means of scatterplots of the surface cross sections at the two frequencies under rain and no-rain conditions. Approximate criteria are given on combining attenuation and backscattering methods to increase the effective dynamic range of the radar. The dual-wavelength capability of the radar is also used to examine the vertical structure of the precipitation. Another factor affecting the accuracy of the methods is the drop-size distribution. In the final section of the paper a procedure to estimate the profiled drop-size distribution is applied to the measured radar data.

  8. Single- and dual-fractal analysis of hybridization binding kinetics: biosensor applications.

    PubMed

    Sadana, A; Vo-Dinh, T

    1998-01-01

    The diffusion-limited hybridization kinetics of analyte in solution to a receptor immobilized on a biosensor or immunosensor surface is analyzed within a fractal framework. The data may be analyzed by a single- or a dual-fractal analysis. This was indicated by the regression analysis provided by Sigmaplot. It is of interest to note that the binding rate coefficient and the fractal dimension both exhibit changes in the same direction for both the single-fractal and the dual-fractal analysis examples presented. For example, for a single-fractal analysis and for the hybridization of 10 nM 16CFl (oligonucleotide) to 16B immobilized via sulfosuccinimidyl-6-(biotinamido)hexanoate and streptavidin using chemical and thermal regeneration (Abel, A. P.; Weller, M. G.; Duveneck, G. L.; Ehrat, M. Widmer, H. M. Anal. Chem. 1996, 68, 2905-2912), an increase in the fractal dimension, Df from 1.211 (chemical regeneration) to 1.394 (thermal regeneration), leads to an increase in the binding rate coefficient, k, from 86.53 (chemical regeneration) to 100.0 (thermal regeneration). An increase in the degree of heterogeneity on the biosensor surface leads to an increase in the binding rate coefficient. When a dual-fractal analysis was utilized, an increase in the fractal dimension value from Df1 to Df2 leads to an increase in the binding rate coefficient value from k1 to k2. The fractional order of dependence of the binding rate coefficient, k1, on (a) the analyte (rRNA) concentration in solution and (b) on the fractal dimension, Df1, for the hybridization kinetics to detect Listeria species (Fliss, R.; St-Laurent, M.; Emond, E.; Simard, R. E.; Lemieux, R.; Ettriki, A.; Pandian, S. Appl. Microbiol. Biotechnol. 1995, 43, 717-724.) further reinforces the fractal nature of the system. The binding rate coefficient(s) expressions developed as a function of the analyte concentration in solution and the fractal dimension are of particular value since they provide a means to better control of

  9. The German Dual Apprenticeship System: An Analysis of Its Evolution and Present Challenges.

    ERIC Educational Resources Information Center

    Tremblay, Diane-Gabrielle; Le Bot, Irene

    The evolution of Germany's dual apprenticeship system and the challenges now facing it were reviewed. The following topics were considered: (1) the progression from craft guilds to vocational training; (2) the history of Germany's dual apprenticeship system from its organization in the 1970s; (4) apprenticeship in the dual system; (3) Germany's…

  10. Space Shuttle Main Engine performance analysis

    NASA Technical Reports Server (NTRS)

    Santi, L. Michael

    1993-01-01

    For a number of years, NASA has relied primarily upon periodically updated versions of Rocketdyne's power balance model (PBM) to provide space shuttle main engine (SSME) steady-state performance prediction. A recent computational study indicated that PBM predictions do not satisfy fundamental energy conservation principles. More recently, SSME test results provided by the Technology Test Bed (TTB) program have indicated significant discrepancies between PBM flow and temperature predictions and TTB observations. Results of these investigations have diminished confidence in the predictions provided by PBM, and motivated the development of new computational tools for supporting SSME performance analysis. A multivariate least squares regression algorithm was developed and implemented during this effort in order to efficiently characterize TTB data. This procedure, called the 'gains model,' was used to approximate the variation of SSME performance parameters such as flow rate, pressure, temperature, speed, and assorted hardware characteristics in terms of six assumed independent influences. These six influences were engine power level, mixture ratio, fuel inlet pressure and temperature, and oxidizer inlet pressure and temperature. A BFGS optimization algorithm provided the base procedure for determining regression coefficients for both linear and full quadratic approximations of parameter variation. Statistical information relative to data deviation from regression derived relations was also computed. A new strategy for integrating test data with theoretical performance prediction was also investigated. The current integration procedure employed by PBM treats test data as pristine and adjusts hardware characteristics in a heuristic manner to achieve engine balance. Within PBM, this integration procedure is called 'data reduction.' By contrast, the new data integration procedure, termed 'reconciliation,' uses mathematical optimization techniques, and requires both

  11. Space Shuttle Main Engine performance analysis

    NASA Astrophysics Data System (ADS)

    Santi, L. Michael

    1993-11-01

    For a number of years, NASA has relied primarily upon periodically updated versions of Rocketdyne's power balance model (PBM) to provide space shuttle main engine (SSME) steady-state performance prediction. A recent computational study indicated that PBM predictions do not satisfy fundamental energy conservation principles. More recently, SSME test results provided by the Technology Test Bed (TTB) program have indicated significant discrepancies between PBM flow and temperature predictions and TTB observations. Results of these investigations have diminished confidence in the predictions provided by PBM, and motivated the development of new computational tools for supporting SSME performance analysis. A multivariate least squares regression algorithm was developed and implemented during this effort in order to efficiently characterize TTB data. This procedure, called the 'gains model,' was used to approximate the variation of SSME performance parameters such as flow rate, pressure, temperature, speed, and assorted hardware characteristics in terms of six assumed independent influences. These six influences were engine power level, mixture ratio, fuel inlet pressure and temperature, and oxidizer inlet pressure and temperature. A BFGS optimization algorithm provided the base procedure for determining regression coefficients for both linear and full quadratic approximations of parameter variation. Statistical information relative to data deviation from regression derived relations was also computed. A new strategy for integrating test data with theoretical performance prediction was also investigated. The current integration procedure employed by PBM treats test data as pristine and adjusts hardware characteristics in a heuristic manner to achieve engine balance. Within PBM, this integration procedure is called 'data reduction.' By contrast, the new data integration procedure, termed 'reconciliation,' uses mathematical optimization techniques, and requires both

  12. Burst Testing and Analysis of Superalloy Disks With a Dual Grain Microstructure

    NASA Technical Reports Server (NTRS)

    Gayda, John; Kantzos, Pete

    2006-01-01

    Elastic-plastic finite element analyses of room temperature burst tests on four superalloy disks were conducted and reported in this paper. Two alloys, Rene 104 (General Electric Aircraft Engines) and Alloy 10 (Honeywell Engines & Systems), were studied. For both alloys an advanced dual microstructure disk, fine grain bore and coarse grain rim, were analyzed and compared with conventional disks with uniform microstructures, coarse grain for Rene 104 and fine grain for Alloy 10. The analysis and experimental data were in good agreement up to burst. At burst, the analysis underestimated the speed and growth of the Rene 104 disks, but overestimated the speed and growth of the Alloy 10 disks. Fractography revealed that the Alloy 10 disks displayed significant surface microcracking and coalescence in comparison to Rene 104 disks. This phenomenon may help explain the differences between the Alloy 10 disks and the Rene 104 disks, as well as the observed deviations between analytical and experimental data at burst.

  13. Space Operations Center - A concept analysis

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The Space Operations Center (SOC) which is a concept for a Shuttle serviced, permanent, manned facility in low earth orbit is viewed as a major candidate for the manned space flight following the completion of an operational Shuttle. The primary objectives of SOC are: (1) the construction, checkout, and transfer to operational orbit of large, complex space systems, (2) on-orbit assembly, launch, recovery, and servicing of manned and unmanned spacecraft, (3) managing operations of co-orbiting free-flying satellites, and (4) the development of reduced dependence on earth for control and resupply. The structure of SOC, a self-contained orbital facility containing several Shuttle launched modules, includes the service, habitation, and logistics modules as well as construction, and flight support facilities. A schedule is proposed for the development of SOC over ten years and costs for the yearly programs are estimated.

  14. A generalized analysis of solar space heating

    NASA Astrophysics Data System (ADS)

    Clark, J. A.

    A life-cycle model is developed for solar space heating within the United States. The model consists of an analytical relationship among five dimensionless parameters that include all pertinent technical, climatological, solar, operating and economic factors that influence the performance of a solar space heating system. An important optimum condition presented is the break-even metered cost of conventional fuel at which the cost of the solar system is equal to that of a conventional heating system. The effect of Federal (1980) and State (1979) income tax credits on these costs is determined. A parameter that includes both solar availability and solar system utilization is derived and plotted on a map of the U.S. This parameter shows the most favorable present locations for solar space heating application to be in the Central and Mountain States. The data employed are related to the rehabilitated solar data recently made available by the National Climatic Center.

  15. Uncertainty Analysis in Space Radiation Protection

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.

    2011-01-01

    Space radiation is comprised of high energy and charge (HZE) nuclei, protons, and secondary radiation including neutrons. The uncertainties in estimating the health risks from galactic cosmic rays (GCR) are a major limitation to the length of space missions, the evaluation of potential risk mitigation approaches, and application of the As Low As Reasonably Achievable (ALARA) principle. For long duration space missio ns, risks may approach radiation exposure limits, therefore the uncertainties in risk projections become a major safety concern and methodologies used for ground-based works are not deemed to be sufficient. NASA limits astronaut exposures to a 3% risk of exposure induced death (REID) and protects against uncertainties in risks projections using an assessment of 95% confidence intervals in the projection model. We discuss NASA s approach to space radiation uncertainty assessments and applications for the International Space Station (ISS) program and design studies of future missions to Mars and other destinations. Several features of NASA s approach will be discussed. Radiation quality descriptions are based on the properties of radiation tracks rather than LET with probability distribution functions (PDF) for uncertainties derived from radiobiology experiments at particle accelerators. The application of age and gender specific models for individual astronauts is described. Because more than 90% of astronauts are never-smokers, an alternative risk calculation for never-smokers is used and will be compared to estimates for an average U.S. population. Because of the high energies of the GCR limits the benefits of shielding and the limited role expected for pharmaceutical countermeasures, uncertainty reduction continues to be the optimal approach to improve radiation safety for space missions.

  16. Combined analysis of intracellular calcium with dual excitation fluorescence photometry and imaging

    NASA Astrophysics Data System (ADS)

    Uttenweiler, Dietmar; Wojciechowski, Reinhold; Makabe, Makoto; Veigel, Claudia; Fink, Rainer H.

    1995-10-01

    We have developed an integrated microscopy system combining fast dual-excitation fluorescence photometry and digital image analysis with high spatial resolution, based mainly on standard components. With the combination of these well-established techniques in one setup it is possible to monitor intracellular calcium with both sufficiently high temporal and high spatial resolution on the same preparation for many biological applications. Our system consists of a commercially available dual-excitation photometric system, an attached ICCD camera, and a frame grabber board. With this integrated setup one can easily switch between the fast photometric mode and the imaging mode. We used the system to record Fura-2 calcium images (340/380 nm ratios), which were correlated with the faster spot measurements and were analyzed by means of image processing. As an example for its application we reconstructed caffeine-induced calcium transient released from the sarcoplasmic reticulum of isolated and permeabilized skeletal muscle fiber preparations. Such a combined technique will also be important for cellular studies using other fluorescence indicators. Additionally, the described system has an external trigger facility that enables combination with other cell physiological methods, e.g., electrophysiological techniques.

  17. Dual-band beacon experiment over Southeast Asia for ionospheric irregularity analysis

    NASA Astrophysics Data System (ADS)

    Watthanasangmechai, K.; Yamamoto, M.; Saito, A.; Saito, S.; Maruyama, T.; Tsugawa, T.; Nishioka, M.

    2013-12-01

    An experiment of dual-band beacon over Southeast Asia was started in March 2012 in order to capture and analyze ionospheric irregularities in equatorial region. Five GNU Radio Beacon Receivers (GRBRs) were aligned along 100 degree geographic longitude. The distances between the stations reach more than 500 km. The field of view of this observational network covers +/- 20 degree geomagnetic latitude including the geomagnetic equator. To capture ionospheric irregularities, the absolute TEC estimation technique was developed. The two-station method (Leitinger et al., 1975) is generally accepted as a suitable method to estimate TEC offsets of dual-band beacon experiment. However, the distances between the stations directly affect on the robustness of the technique. In Southeast Asia, the observational network is too sparse to attain a benefit of the classic two-station method. Moreover, the least-squares approch used in the two-station method tries too much to adjust the small scales of the TEC distribution which are the local minima. We thus propose a new technique to estimate the TEC offsets with the supporting data from absolute GPS-TEC from local GPS receivers and the ionospheric height from local ionosondes. The key of the proposed technique is to utilize the brute-force technique with weighting function to find the TEC offset set that yields a global minimum of RMSE in whole parameter space. The weight is not necessary when the TEC distribution is smooth, while it significantly improves the TEC estimation during the ESF events. As a result, the latitudinal TEC shows double-hump distribution because of the Equatorial Ionization Anomaly (EIA). In additions, the 100km-scale fluctuations from an Equatorial Spread F (ESF) are captured at night time in equinox seasons. The plausible linkage of the meridional wind with triggering of ESF is under invatigating and will be presented. The proposed method is successful to estimate the latitudinal TEC distribution from dual

  18. Including the effect of motion artifacts in noise and performance analysis of dual-energy contrast-enhanced mammography

    NASA Astrophysics Data System (ADS)

    Allec, N.; Abbaszadeh, S.; Scott, C. C.; Lewin, J. M.; Karim, K. S.

    2012-12-01

    In contrast-enhanced mammography (CEM), the dual-energy dual-exposure technique, which can leverage existing conventional mammography infrastructure, relies on acquiring the low- and high-energy images using two separate exposures. The finite time between image acquisition leads to motion artifacts in the combined image. Motion artifacts can lead to greater anatomical noise in the combined image due to increased mismatch of the background tissue in the images to be combined, however the impact has not yet been quantified. In this study we investigate a method to include motion artifacts in the dual-energy noise and performance analysis. The motion artifacts are included via an extended cascaded systems model. To validate the model, noise power spectra of a previous dual-energy clinical study are compared to that of the model. The ideal observer detectability is used to quantify the effect of motion artifacts on tumor detectability. It was found that the detectability can be significantly degraded when motion is present (e.g., detectability of 2.5 mm radius tumor decreased by approximately a factor of 2 for translation motion on the order of 1000 μm). The method presented may be used for a more comprehensive theoretical noise and performance analysis and fairer theoretical performance comparison between dual-exposure techniques, where motion artifacts are present, and single-exposure techniques, where low- and high-energy images are acquired simultaneously and motion artifacts are absent.

  19. Including the effect of motion artifacts in noise and performance analysis of dual-energy contrast-enhanced mammography.

    PubMed

    Allec, N; Abbaszadeh, S; Scott, C C; Lewin, J M; Karim, K S

    2012-12-21

    In contrast-enhanced mammography (CEM), the dual-energy dual-exposure technique, which can leverage existing conventional mammography infrastructure, relies on acquiring the low- and high-energy images using two separate exposures. The finite time between image acquisition leads to motion artifacts in the combined image. Motion artifacts can lead to greater anatomical noise in the combined image due to increased mismatch of the background tissue in the images to be combined, however the impact has not yet been quantified. In this study we investigate a method to include motion artifacts in the dual-energy noise and performance analysis. The motion artifacts are included via an extended cascaded systems model. To validate the model, noise power spectra of a previous dual-energy clinical study are compared to that of the model. The ideal observer detectability is used to quantify the effect of motion artifacts on tumor detectability. It was found that the detectability can be significantly degraded when motion is present (e.g., detectability of 2.5 mm radius tumor decreased by approximately a factor of 2 for translation motion on the order of 1000 μm). The method presented may be used for a more comprehensive theoretical noise and performance analysis and fairer theoretical performance comparison between dual-exposure techniques, where motion artifacts are present, and single-exposure techniques, where low- and high-energy images are acquired simultaneously and motion artifacts are absent. PMID:23202244

  20. Highly flexible nearest-neighbor-search associative memory with integrated k nearest neighbor classifier, configurable parallelism and dual-storage space

    NASA Astrophysics Data System (ADS)

    An, Fengwei; Mihara, Keisuke; Yamasaki, Shogo; Chen, Lei; Jürgen Mattausch, Hans

    2016-04-01

    VLSI-implementations are often applied to solve the high computational cost of pattern matching but have usually low flexibility for satisfying different target applications. In this paper, a digital word-parallel associative memory architecture for k nearest neighbor (KNN) search, which is one of the most basic algorithms in pattern recognition, is reported applying the squared Euclidean distance measure. The reported architecture features reconfigurable parallelism, dual-storage space to achieve a flexible number of reference vectors, and a dedicated majority vote circuit. Programmable switching circuits, located between vector components, enable scalability of the searching parallelism by configuring the reference feature-vector dimensionality. A pipelined storage with dual static-random-access-memory (SRAM) cells for each unit and an intermediate winner control circuit are designed to extend the applicability by improving the flexibility of the reference storage. A test chip in 180 nm CMOS technology, which has 32 rows, 4 elements in each row and 2-parallel 8-bit dual-components in each element, consumes altogether 61.4 mW and in particular only 11.9 mW during the reconfigurable KNN classification (at 45.58 MHz and 1.8 V).

  1. Ellipsometric analysis of materials degradation in space

    NASA Technical Reports Server (NTRS)

    Woollam, John A.; Snyder, Paul G.; De, Bhola N.

    1990-01-01

    The fundamentals of variable angle spectroscopic ellipsometry (VASE) are reviewed, and its usefulness in studying the effect of atomic oxygen on space coatings such as indium tin oxide (ITO), silicon dioxide, and aluminum oxide is discussed. Monolayer sensitive and nondestructive VASE is found to be an effective technique for monitoring the atomic oxygen diffusion through the aluminum oxide and silicon dioxide protective overcoatings on space reflectors. Ashing of ITO/silicon samples had the net effect of annealing the film inside the plasma. The annealing effect was supported both by structural changes as verified by X-ray diffraction measurements and by increased absorbance in the spectral range below 3 eV as measured by VASE.

  2. Investigating the environmental factors affecting the toxicity of silver nanoparticles in Escherichia coli with dual fluorescence analysis.

    PubMed

    Hong, Wei; Li, Luzhi; Liang, Junting; Wang, Jingjing; Wang, Xuanyu; Xu, Shengmin; Wu, Lijun; Zhao, Guoping; Xu, An; Chen, Shaopeng

    2016-07-01

    Flow cytometric investigation of the toxic effects of nanoparticles on bacteria is highly challenging and not sensitive due to the interference of aggregated nanoparticles: aggregated nanoparticles and bacteria are similar in size. In this study, an optimized dual fluorescence flow cytometric analysis was developed using PI-Lac::GFP (propidium iodide stained Escherichia coli (lac::GFP)) to monitor the toxicity of silver nanoparticles (AgNPs). As compared with single fluorescence analysis, the dual fluorescence analysis enabled more accurate evaluation of the toxic effects of AgNPs. We used this dual fluorescence analysis to investigate how AgNPs toxicity was affected by two typical environmental factors, divalent metal ions and surfactants. Our data revealed that Cu(2+) and SDS significantly enhanced the toxicity of AgNPs in a dose-dependent manner. SDS enhanced the toxicity of both AgNPs and Ag(+) ions, whereas Cu(2+) increased the toxicity of AgNPs but not dissolved Ag(+) ions. Our results suggest that this dual fluorescence analysis can be used to evaluate the toxicity of AgNPs accurately and sensitively. PMID:27135694

  3. Browsing Space Weather Data and Models with the Integrated Space Weather Analysis (iSWA) System

    NASA Technical Reports Server (NTRS)

    Maddox, Marlo M.; Mullinix, Richard E.; Berrios, David H.; Hesse, Michael; Rastaetter, Lutz; Pulkkinen, Antti; Hourcle, Joseph A.; Thompson, Barbara J.

    2011-01-01

    The Integrated Space Weather Analysis (iSWA) System is a comprehensive web-based platform for space weather information that combines data from solar, heliospheric and geospace observatories with forecasts based on the most advanced space weather models. The iSWA system collects, generates, and presents a wide array of space weather resources in an intuitive, user-configurable, and adaptable format - thus enabling users to respond to current and future space weather impacts as well as enabling post-impact analysis. iSWA currently provides over 200 data and modeling products, and features a variety of tools that allow the user to browse, combine, and examine data and models from various sources. This presentation will consist of a summary of the iSWA products and an overview of the customizable user interfaces, and will feature several tutorial demonstrations highlighting the interactive tools and advanced capabilities.

  4. Hubble Space Telescope Crew Rescue Analysis

    NASA Technical Reports Server (NTRS)

    Hamlin, Teri L.; Canga, Michael A.; Cates, Grant R.

    2010-01-01

    In the aftermath of the 2003 Columbia accident, NASA removed the Hubble Space Telescope (HST) Servicing Mission 4 (SM4) from the Space Shuttle manifest. Reasons cited included concerns that the risk of flying the mission would be too high. The HST SM4 was subsequently reinstated and flown as Space Transportation System (STS)-125 because of improvements in the ascent debris environment, the development of techniques for astronauts to perform on orbit repairs to damaged thermal protection, and the development of a strategy to provide a viable crew rescue capability. However, leading up to the launch of STS-125, the viability of the HST crew rescue capability was a recurring topic. For STS-125, there was a limited amount of time available to perform a crew rescue due to limited consumables (power, oxygen, etc.) available on the Orbiter. The success of crew rescue depended upon several factors, including when a problem was identified; when and what actions, such as powering down, were begun to conserve consumables; and where the Launch on Need (LON) vehicle was in its ground processing cycle. Crew rescue success also needed to be weighed against preserving the Orbiter s ability to have a landing option in case there was a problem with the LON vehicle. This paper focuses on quantifying the HST mission loss of crew rescue capability using Shuttle historical data and various power down strategies. Results from this effort supported NASA s decision to proceed with STS-125, which was successfully completed on May 24th 2009.

  5. Space shuttle rendezous, radiation and reentry analysis code

    NASA Technical Reports Server (NTRS)

    Mcglathery, D. M.

    1973-01-01

    A preliminary space shuttle mission design and analysis tool is reported emphasizing versatility, flexibility, and user interaction through the use of a relatively small computer (IBM-7044). The Space Shuttle Rendezvous, Radiation and Reentry Analysis Code is used to perform mission and space radiation environmental analyses for four typical space shuttle missions. Included also is a version of the proposed Apollo/Soyuz rendezvous and docking test mission. Tangential steering circle to circle low-thrust tug orbit raising and the effects of the trapped radiation environment on trajectory shaping due to solar electric power losses are also features of this mission analysis code. The computational results include a parametric study on single impulse versus double impulse deorbiting for relatively low space shuttle orbits as well as some definitive data on the magnetically trapped protons and electrons encountered on a particular mission.

  6. An extensive electrostatic analysis of dual material gate all around tunnel FET (DMGAA-TFET)

    NASA Astrophysics Data System (ADS)

    Dash, S.; Mishra, G. P.

    2016-06-01

    In the proposed work an analytical model of a p-channel dual material gate all around tunnel FET (DMGAA-TFET) is presented and its performance is compared with the conventional GAA-TFET. The electrostatic potential profile of the model is obtained using 2-D Laplace’s solution in the cylindrical coordinate system. A quantitative study of the drain current has been carried out using electric field in the z-axis and tunneling path. However the potential and current analysis is prolonged to different combinations of gate length in the DMGAA-TFET model. The results show an improvement in drain current and subthreshold swing as compared to GAA-TFET, which makes this model a potential replacement for low power application. Also the effect of scaling of the gate oxide thickness and cylindrical pillar diameter on the surface potential, initial tunneling point and tunneling current are analyzed.

  7. Analysis of the Transient Response of a Dual-Fed RC Transmission Line

    PubMed Central

    Dorraki, Mohsen; Cambrell, Gregory K.; Abbott, Derek

    2015-01-01

    The transient analysis of a uniform transmission line of finite length is considered in this paper. For the first time this paper provides an analytical expression for the time-domain response of an RC transmission line, which is stimulated by a step function that is fed into both ends of the transmission line. In particular, we find an analytical expression for the step response at the center of the transmission line, in order to determine the worst-case rise time. This is of interest, for example, in large charge-coupled device (CCD) arrays, where long polysilicon lines are dual-fed in order to mitigate degradation in rise time. The analytical expressions for the RC transmission line are supported by computer-simulated lumped RC models. PMID:25679379

  8. Design and multifidelity analysis of dual mode scramjet compression system using coupled NPSS and fluent simulation

    NASA Astrophysics Data System (ADS)

    Vijayakumar, Nandakumar

    Hypersonic airbreathing engines mark a potential future development of the aerospace industry and immense efforts have been taken in gaining knowledge in them for the past decades. The physical phenomenon occurring at the hypersonic flow regime makes the design and performance prediction of a scramjet engine hard. Though cutting-edge simulation tools fight their way toward accurate prediction of the environment, the time consumed by the entire process in designing and analyzing a scramjet engine and its component may be exorbitant. A multi-fidelity approach for designing a scramjet with a cruising Mach number of 6 is detailed in this research where high-order simulations are applied according to the physics involved in the component. Two state-of-the-art simulation tools were used to take the aerodynamic and propulsion disciplines into account for realistic prediction of the individual components as well as the entire scramjet. The specific goal of this research is to create a virtual environment to design and analyze a hypersonic, two-dimensional, planar inlet and isolator to check its operability for a dual-mode scramjet engine. The dual mode scramjet engine starts at a Mach number of 3.5 where it operates as a ramjet and accelerates to Mach 6 to be operated as a scramjet engine. The intercomponent interaction between the compression components with the rest of the engine is studied by varying the fidelity of the numerical simulation according to the complexity of the situation. Efforts have been taken to track the transition Mach number as it switches from ramjet to scramjet. A complete scramjet assembly was built using the Numerical Propulsion Simulation System (NPSS) and the performance of the engine was evaluated for various scenarios. Different numerical techniques were opted for varying the fidelity of the analysis with the highest fidelity consisting of 2D RANS CFD simulation. The interaction between the NPSS elements with the CFD solver is governed by the

  9. Single-frequency, dual-GNSS versus dual-frequency, single-GNSS: a low-cost and high-grade receivers GPS-BDS RTK analysis

    NASA Astrophysics Data System (ADS)

    Odolinski, Robert; Teunissen, Peter J. G.

    2016-06-01

    The concept of single-frequency, dual-system (SF-DS) real-time kinematic (RTK) positioning has become feasible since, for instance, the Chinese BeiDou Navigation Satellite System (BDS) has become operational in the Asia-Pacific region. The goal of the present contribution is to investigate the single-epoch RTK performance of such a dual-system and compare it to a dual-frequency, single-system (DF-SS). As the SF-DS we investigate the L1 GPS + B1 BDS model, and for DF-SS we take L1, L2 GPS and B1, B2 BDS, respectively. Two different locations in the Asia-Pacific region are analysed with varying visibility of the BDS constellation, namely Perth in Australia and Dunedin in New Zealand. To emphasize the benefits of such a model we also look into using low-cost ublox single-frequency receivers and compare such SF-DS RTK performance to that of a DF-SS, based on much more expensive survey-grade receivers. In this contribution a formal and empirical analysis is given. It will be shown that with the SF-DS higher elevation cut-off angles than the conventional 10° or 15° can be used. The experiment with low-cost receivers for the SF-DS reveals (for the first time) that it has the potential to achieve comparable ambiguity resolution performance to that of a DF-SS (L1, L2 GPS), based on the survey-grade receivers.

  10. Does Dual Enrollment Increase Students' Success in College? Evidence from a Quasi-Experimental Analysis of Dual Enrollment in New York City

    ERIC Educational Resources Information Center

    Allen, Drew; Dadgar, Mina

    2012-01-01

    This article discusses new evidence on the effectiveness of dual enrollment in increasing college achievement in New York City (NYC). After reviewing existing research on the effectiveness of dual enrollment programs, the authors discuss the results of a recent evaluation of College Now, the dual enrollment program of The City University of New…

  11. Economic analysis of new space transportation systems: Executive summary

    NASA Technical Reports Server (NTRS)

    1971-01-01

    An economic analysis of alternative space transportation systems is presented. Results indicate that the expendable systems represent modest investments, but the recurring costs of operation would remain high. The space shuttle and tug system requires a substantial investment, but would substantially reduce the recurring costs of operation. Economic benefits and costs of the different systems are also analyzed. Findings are summarized.

  12. Harmonic analysis on local fields and adelic spaces. II

    NASA Astrophysics Data System (ADS)

    Osipov, Denis V.; Parshin, Aleksei N.

    2011-08-01

    We develop harmonic analysis in certain categories of filtered Abelian groups and vector spaces. The objects of these categories include local fields and adelic spaces arising from arithmetic surfaces. We prove some structure theorems for quotients of the adèle groups of algebraic and arithmetic surfaces.

  13. Economic analysis of materials processing in space: Introduction

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Space processing concepts investigated included an unmanned space factory, and a permanently launched factory. Product lines chosen for analysis were: (1) turbine blades, (2) tungsten targets for X-ray machines, (3) 1 sub G subclass separation by electrophoresis, and (4) high-price exotic crystals. The turbine blade, and 1 sub G products are considered promising candidates.

  14. Dual redundant arm system operational quality measures and their applications - Dynamic measures

    NASA Technical Reports Server (NTRS)

    Lee, Sukhan; Kim, Sungbok

    1990-01-01

    Dual-arm dynamic operation quality measures are presented which quantify the efficiency and capability of generating Cartesian accelerations by two cooperative arms based on the analysis of dual-arm dynamic interactions. Dual-arm dynamic manipulability is defined as the efficiency of generating Cartesian accelerations under the dynamic and kinematic interactions between individual arms and an object under manipulation. The analysis of dual-arm dynamic interactions is based on the so-called Cartesian space agent model of an arm, which represents an individual arm as a force source acting upon a point mass with the effective Cartesian space arm dynamics and an environment or an object under manipulation. The Cartesian space agent model of an arm makes it possible to derive the dynamic and kinematic constraints involved in the transport, assembly and grasping modes of dual-arm cooperation. A task-oriented operational quality measure, (TOQd) is defined by evaluating dual-arm dynamic manipulability in terms of given task requirements. TOQd is used in dual-arm joint configuration optimization. Simulation results are shown. A complete set of forward dynamic equations for a dual-arm system is derived, and dual-arm dynamic operational quality measures for various modes of dual-arm cooperation allowing sliding contacts are established.

  15. Hubble Space Telescope Crew Rescue Analysis

    NASA Technical Reports Server (NTRS)

    Hamlin, Teri L.; Canga, Michael; Boyer, Roger; Thigpen, Eric

    2009-01-01

    In the aftermath of the 2003 Columbia accident NASA removed the Hubble Space Telescope (HST) Servicing Mission 4 (SM4) from the Space Shuttle manifest. Reasons cited included concerns that the risk of flying the mission would be too high. There was at the time no viable technique to repair the orbiter s thermal protection system if it were to be damaged by debris during ascent. Furthermore in the event of damage, since the mission was not to the International Space Station, there was no safe haven for the crew to wait for an extended period of time for a rescue. The HST servicing mission was reconsidered because of improvements in the ascent debris environment, the development of techniques for the astronauts to perform on orbit repairs to damage thermal protection, and the development of a strategy to provide a crew rescue capability. However, leading up to the launch of servicing mission, the HST crew rescue capability was a recurring topic. For HST there was a limited amount of time available to perform a crew rescue because of the limited consumables available on the Orbiter. The success of crew rescue depends upon several factors including when a problem is identified, when and to what extent power down procedures are begun, and where the rescue vehicle is in its ground processing cycle. Severe power downs maximize crew rescue success but would eliminate the option for the orbiter servicing the HST to attempt a landing. Therefore, crew rescue success needed to be weighed against preserving the ability of the orbiter to have landing option in case there was a problem with the rescue vehicle. This paper focuses on quantification of the HST mission loss of crew rescue capability using Shuttle historical data and various power down capabilities. That work supported NASA s decision to proceed with the HST service mission, which was successfully completed on May 24th 2009.

  16. Space Shuttle Orbiter windshield bird impact analysis

    NASA Technical Reports Server (NTRS)

    Edelstein, Karen S.; Mccarty, Robert E.

    1988-01-01

    The NASA Space Shuttle Orbiter's windshield employs three glass panes separated by air gaps. The brittleness of the glass offers much less birdstrike energy-absorption capability than the laminated polycarbonate windshields of more conventional aircraft; attention must accordingly be given to the risk of catastrophic bird impact, and to methods of strike prevention that address bird populations around landing sites rather than the modification of the window's design. Bird populations' direct reduction, as well as careful scheduling of Orbiter landing times, are suggested as viable alternatives. The question of birdstrike-resistant glass windshield design for hypersonic aerospacecraft is discussed.

  17. Feasibility analysis of gravitational experiments in space

    NASA Technical Reports Server (NTRS)

    Everitt, C. W. F.

    1977-01-01

    Experiments on gravitation and general relativity suggested by different workers in the past ten or more years are reviewed, their feasibility examined, and the advantages of performing them in space were studied. The experiments include: (1) the gyro relativity experiment; (2) experiments to test the equivalence of gravitational and inertial mass; (3) an experiment to look for nongeodesic motion of spinning bodies in orbit around the earth; (4) experiments to look for changes of the gravitational constant G with time; (5) a variety of suggestions; laboratory tests of experimental gravity; and (6) gravitational wave experiments.

  18. Body Composition Comparison: Bioelectric Impedance Analysis with Dual-Energy X-Ray Absorptiometry in Adult Athletes

    ERIC Educational Resources Information Center

    Company, Joe; Ball, Stephen

    2010-01-01

    The primary purpose of this study was to investigate the accuracy of the DF50 (ImpediMed Ltd, Eight Mile Plains, Queensland, Australia) bioelectrical impedance analysis device using dual-energy x-ray absorptiometry as the criterion in two groups: endurance athletes and power athletes. The secondary purpose was to develop accurate body fat…

  19. Dual-Doppler Feasibility Study

    NASA Technical Reports Server (NTRS)

    Huddleston, Lisa L.

    2012-01-01

    When two or more Doppler weather radar systems are monitoring the same region, the Doppler velocities can be combined to form a three-dimensional (3-D) wind vector field thus providing for a more intuitive analysis of the wind field. A real-time display of the 3-D winds can assist forecasters in predicting the onset of convection and severe weather. The data can also be used to initialize local numerical weather prediction models. Two operational Doppler Radar systems are in the vicinity of Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS); these systems are operated by the 45th Space Wing (45 SW) and the National Weather Service Melbourne, Fla. (NWS MLB). Dual-Doppler applications were considered by the 45 SW in choosing the site for the new radar. Accordingly, the 45th Weather Squadron (45 WS), NWS MLB and the National Aeronautics and Space Administration tasked the Applied Meteorology Unit (AMU) to investigate the feasibility of establishing dual-Doppler capability using the two existing systems. This study investigated technical, hardware, and software requirements necessary to enable the establishment of a dual-Doppler capability. Review of the available literature pertaining to the dual-Doppler technique and consultation with experts revealed that the physical locations and resulting beam crossing angles of the 45 SW and NWS MLB radars make them ideally suited for a dual-Doppler capability. The dual-Doppler equations were derived to facilitate complete understanding of dual-Doppler synthesis; to determine the technical information requirements; and to determine the components of wind velocity from the equation of continuity and radial velocity data collected by the two Doppler radars. Analysis confirmed the suitability of the existing systems to provide the desired capability. In addition, it is possible that both 45 SW radar data and Terminal Doppler Weather Radar data from Orlando International Airport could be used to alleviate any

  20. A gap analysis of meteorological requirements for commercial space operators

    NASA Astrophysics Data System (ADS)

    Stapleton, Nicholas James

    Commercial space companies will soon be the primary method of launching people and supplies into orbit. Among the critical aspects of space launches are the meteorological concerns. Laws and regulations pertaining to meteorological considerations have been created to ensure the safety of the space industry and those living around spaceports; but, are they adequate? Perhaps the commercial space industry can turn to the commercial aviation industry to help answer that question. Throughout its history, the aviation industry has dealt with lessons learned from mishaps due to failures in understanding the significance of weather impacts on operations. Using lessons from the aviation industry, the commercial space industry can preempt such accidents and maintain viability as an industry. Using Lanicci's Strategic Planning Model, this study identified the weather needs of the commercial space industry by conducting three gap analyses. First, a comparative analysis was done between laws and regulations in commercial aviation and those in the commercial space industry pertaining to meteorological support, finding a "legislative gap" between the two industries, as no legal guarantee is in place to ensure weather products remain available to the commercial space industry. A second analysis was conducted between the meteorological services provided for the commercial aviation industry and commercial space industry, finding a gap at facilities not located at an established launch facility or airport. At such facilities, many weather observational technologies would not be present, and would need to be purchased by the company operating the spaceport facility. A third analysis was conducted between the meteorological products and regulations that are currently in existence, and those needed for safe operations within the commercial space industry, finding gaps in predicting lightning, electric field charge, and space weather. Recommendations to address these deficiencies have

  1. NASA Aeronautics and Space Database for bibliometric analysis

    NASA Technical Reports Server (NTRS)

    Powers, R.; Rudman, R.

    2004-01-01

    The authors use the NASA Aeronautics and Space Database to perform bibliometric analysis of citations. This paper explains their research methodology and gives some sample results showing collaboration trends between NASA Centers and other institutions.

  2. Spectral Analysis in High Radiation Space Backgrounds with Robust Fitting

    NASA Technical Reports Server (NTRS)

    Lasche, G. P.; Coldwell, R. L.; Nobel, L. A.; Rester, A. C.; Trombka, J. I.

    1997-01-01

    Spectral analysis software is tested for its ability to fit spectra from space. The approach, which emphasizes the background shape function, is uniquely suited to the identification of weak-strength nuclides in high-radiation background environments.

  3. Network Analysis of a Comprehensive Knowledge Repository Reveals a Dual Role for Ceramide in Alzheimer's Disease.

    PubMed

    Mizuno, Satoshi; Ogishima, Soichi; Kitatani, Kazuyuki; Kikuchi, Masataka; Tanaka, Hiroshi; Yaegashi, Nobuo; Nakaya, Jun

    2016-01-01

    Alzheimer's disease (AD) is the most common cause of senile dementia. Many inflammatory factors such as amyloid-β and pro-inflammatory cytokines are known to contribute to the inflammatory response in the AD brain. Sphingolipids are widely known to have roles in the pathogenesis of inflammatory diseases, where the precise roles for sphingolipids in inflammation-associated pathogenesis of AD are not well understood. Here we performed a network analysis to clarify the importance of sphingolipids and to model relationships among inflammatory factors and sphingolipids in AD. In this study, we have updated sphingolipid signaling and metabolic cascades in a map of AD signaling networks that we named "AlzPathway," a comprehensive knowledge repository of signaling pathways in AD. Our network analysis of the updated AlzPathway indicates that the pathways related to ceramide are one of the primary pathways and that ceramide is one of the important players in the pathogenesis of AD. The results of our analysis suggest the following two prospects about inflammation in AD: (1) ceramide could play important roles in both inflammatory and anti-inflammatory pathways of AD, and (2) several factors such as Sphingomyelinase and Siglec-11 may be associated with ceramide related inflammation and anti-inflammation pathways in AD. In this study, network analysis of comprehensive knowledge repository reveals a dual role for ceramide in AD. This result provides a clue to clarify sphingolipids related inflammatory and anti-inflammatory pathways in AD. PMID:26849355

  4. Multiscale deep drawing analysis of dual-phase steels using grain cluster-based RGC scheme

    NASA Astrophysics Data System (ADS)

    Tjahjanto, D. D.; Eisenlohr, P.; Roters, F.

    2015-06-01

    Multiscale modelling and simulation play an important role in sheet metal forming analysis, since the overall material responses at macroscopic engineering scales, e.g. formability and anisotropy, are strongly influenced by microstructural properties, such as grain size and crystal orientations (texture). In the present report, multiscale analysis on deep drawing of dual-phase steels is performed using an efficient grain cluster-based homogenization scheme. The homogenization scheme, called relaxed grain cluster (RGC), is based on a generalization of the grain cluster concept, where a (representative) volume element consists of p  ×  q  ×  r (hexahedral) grains. In this scheme, variation of the strain or deformation of individual grains is taken into account through the, so-called, interface relaxation, which is formulated within an energy minimization framework. An interfacial penalty term is introduced into the energy minimization framework in order to account for the effects of grain boundaries. The grain cluster-based homogenization scheme has been implemented and incorporated into the advanced material simulation platform DAMASK, which purposes to bridge the macroscale boundary value problems associated with deep drawing analysis to the micromechanical constitutive law, e.g. crystal plasticity model. Standard Lankford anisotropy tests are performed to validate the model parameters prior to the deep drawing analysis. Model predictions for the deep drawing simulations are analyzed and compared to the corresponding experimental data. The result shows that the predictions of the model are in a very good agreement with the experimental measurement.

  5. An analysis of space power system masses

    NASA Technical Reports Server (NTRS)

    Kenny, Barbara H.; Cull, Ronald C.; Kankam, M. David

    1990-01-01

    Various space electrical power system masses are analyzed with particular emphasis on the power management and distribution (PMAD) portion. The electrical power system (EPS) is divided into functional blocks: source, interconnection, storage, transmission, distribution, system control and load. The PMAD subsystem is defined as all the blocks between the source, storage and load, plus the power conditioning equipment required for the source, storage and load. The EPS mass of a wide range of spacecraft is then classified as source, storage or PMAD and tabulated in a database. The intent of the database is to serve as a reference source for PMAD masses of existing and in-design spacecraft. The PMAD masses in the database range from 40 kg/kW to 183 kg/kW across the spacecraft systems studied. Factors influencing the power system mass are identified. These include the total spacecraft power requirements, total amount of load capacity and physical size of the spacecraft. It is found that a new utility class of power systems, represented by Space Station Freedom, is evolving.

  6. ALT space shuttle barometric altimeter altitude analysis

    NASA Technical Reports Server (NTRS)

    Killen, R.

    1978-01-01

    The accuracy was analyzed of the barometric altimeters onboard the space shuttle orbiter. Altitude estimates from the air data systems including the operational instrumentation and the developmental flight instrumentation were obtained for each of the approach and landing test flights. By comparing the barometric altitude estimates to altitudes derived from radar tracking data filtered through a Kalman filter and fully corrected for atmospheric refraction, the errors in the barometric altitudes were shown to be 4 to 5 percent of the Kalman altitudes. By comparing the altitude determined from the true atmosphere derived from weather balloon data to the altitude determined from the U.S. Standard Atmosphere of 1962, it was determined that the assumption of the Standard Atmosphere equations contributes roughly 75 percent of the total error in the baro estimates. After correcting the barometric altitude estimates using an average summer model atmosphere computed for the average latitude of the space shuttle landing sites, the residual error in the altitude estimates was reduced to less than 373 feet. This corresponds to an error of less than 1.5 percent for altitudes above 4000 feet for all flights.

  7. Space system operations and support cost analysis using Markov chains

    NASA Technical Reports Server (NTRS)

    Unal, Resit; Dean, Edwin B.; Moore, Arlene A.; Fairbairn, Robert E.

    1990-01-01

    This paper evaluates the use of Markov chain process in probabilistic life cycle cost analysis and suggests further uses of the process as a design aid tool. A methodology is developed for estimating operations and support cost and expected life for reusable space transportation systems. Application of the methodology is demonstrated for the case of a hypothetical space transportation vehicle. A sensitivity analysis is carried out to explore the effects of uncertainty in key model inputs.

  8. Dual-color dual-focus line-scanning FCS for quantitative analysis of receptor-ligand interactions in living specimens

    PubMed Central

    Dörlich, René M.; Chen, Qing; Niklas Hedde, Per; Schuster, Vittoria; Hippler, Marc; Wesslowski, Janine; Davidson, Gary; Nienhaus, G. Ulrich

    2015-01-01

    Cellular communication in multi-cellular organisms is mediated to a large extent by a multitude of cell-surface receptors that bind specific ligands. An in-depth understanding of cell signaling networks requires quantitative information on ligand-receptor interactions within living systems. In principle, fluorescence correlation spectroscopy (FCS) based methods can provide such data, but live-cell applications have proven extremely challenging. Here, we have developed an integrated dual-color dual-focus line-scanning fluorescence correlation spectroscopy (2c2f lsFCS) technique that greatly facilitates live-cell and tissue experiments. Absolute ligand and receptor concentrations and their diffusion coefficients within the cell membrane can be quantified without the need to perform additional calibration experiments. We also determine the concentration of ligands diffusing in the medium outside the cell within the same experiment by using a raster image correlation spectroscopy (RICS) based analysis. We have applied this robust technique to study the interactions of two Wnt antagonists, Dickkopf1 and Dickkopf2 (Dkk1/2), to their cognate receptor, low-density-lipoprotein-receptor related protein 6 (LRP6), in the plasma membrane of living HEK293T cells. We obtained significantly lower affinities than previously reported using in vitro studies, underscoring the need to measure such data on living cells or tissues. PMID:25951521

  9. Dynamics analysis of space robot manipulator with joint clearance

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Bai, Zheng Feng

    2011-04-01

    A computational methodology for analysis of space robot manipulator systems, considering the effects of the clearances in the joint, is presented. The contact dynamics model in joint clearance is established using the nonlinear equivalent spring-damp model and the friction effect is considered using the Coulomb friction model. The space robot system dynamic equation of manipulator with clearance is established. Then the dynamics simulation is presented and the dynamics characteristics of robot manipulator with clearance are analyzed. This work provides a practical method to analyze the dynamics characteristics of space robot manipulator with joint clearance and improves the engineering application. The computational methodology can predict the effects of clearance on space robot manipulator preferably, which is the basis of space robot manipulator design, precision analysis and ground test.

  10. Surface analysis of space telescope material specimens

    NASA Technical Reports Server (NTRS)

    Fromhold, A. T.; Daneshvar, K.

    1985-01-01

    Qualitative and quantitative data on Space Telescope materials which were exposed to low Earth orbital atomic oxygen in a controlled experiment during the 41-G (STS-17) mission were obtained utilizing the experimental techniques of Rutherford backscattering (RBS), particle induced X-ray emission (PIXE), and ellipsometry (ELL). The techniques employed were chosen with a view towards appropriateness for the sample in question, after consultation with NASA scientific personnel who provided the material specimens. A group of eight samples and their controls selected by NASA scientists were measured before and after flight. Information reported herein include specimen surface characterization by ellipsometry techniques, a determination of the thickness of the evaporated metal specimens by RBS, and a determination of trace impurity species present on and within the surface by PIXE.

  11. Space shuttle entry and landing navigation analysis

    NASA Technical Reports Server (NTRS)

    Jones, H. L.; Crawford, B. S.

    1974-01-01

    A navigation system for the entry phase of a Space Shuttle mission which is an aided-inertial system which uses a Kalman filter to mix IMU data with data derived from external navigation aids is evaluated. A drag pseudo-measurement used during radio blackout is treated as an additional external aid. A comprehensive truth model with 101 states is formulated and used to generate detailed error budgets at several significant time points -- end-of-blackout, start of final approach, over runway threshold, and touchdown. Sensitivity curves illustrating the effect of variations in the size of individual error sources on navigation accuracy are presented. The sensitivity of the navigation system performance to filter modifications is analyzed. The projected overall performance is shown in the form of time histories of position and velocity error components. The detailed results are summarized and interpreted, and suggestions are made concerning possible software improvements.

  12. Inverse Calibration of the Dual-Permeability Model MACRO: Theoretical Analysis and Application to Microlysimeter Experiments.

    NASA Astrophysics Data System (ADS)

    Roulier, S.; Jarvis, N.

    2003-12-01

    Macropore flow is a key factor for determining chemical transport in unsaturated soils, but the description of the complex processes involved in macropore flow requires several parameters that cannot be easily measured. Inverse modeling procedures are increasingly used for model calibration, because they are objective and reproducible. But this is only true when the problem is well-posed: an ill-posed problem leads to parameter nonuniqueness, and thus contributes to poor model performance, like error and/or uncertainty in model predictions. Factors linked to nonuniqueness are most often related to sensitivity issues and/or correlation among two or several parameters. This study focused on the use of inverse techniques to estimate parameters controlling macropore flow, transport, and transformation processes in the dual porosity/dual-permeability model of water flow and solute transport MACRO. MACRO was used together with the inverse modeling package SUFI. The Bayesian (global) approach followed by SUFI is stable, converging, and robust. Moreover, the procedure also predicts a posterior uncertainty domain for the estimated parameters. A theoretical study was carried out to test the inverse modeling tool SUFI/MACRO. Generated "dummy" data set were used for this purpose, representing transient leaching experiment for tracers and reactive solutes in small soil columns (20 cm height). General issues related to inverse modeling such as internal correlation and sensitivity were investigated, with the help of response surface analysis, as well as the influence of the choice of the goal function used in the inverse procedure. Attention was also focused on the most appropriate experimental design necessary for a reliable parameter estimation. The procedure was then applied to real data, obtained from tracer leaching experiments carried out on microlysimeters. Based on calculated model efficiencies, MACRO/SUFI gave good predictions of water movement and tracer transport. This

  13. Genetic Evaluation of Dual-Purpose Buffaloes (Bubalus bubalis) in Colombia Using Principal Component Analysis

    PubMed Central

    Agudelo-Gómez, Divier; Pineda-Sierra, Sebastian; Cerón-Muñoz, Mario Fernando

    2015-01-01

    Genealogy and productive information of 48621 dual-purpose buffaloes born in Colombia between years 1996 and 2014 was used. The following traits were assessed using one-trait models: milk yield at 270 days (MY270), age at first calving (AFC), weaning weight (WW), and weights at the following ages: first year (W12), 18 months (W18), and 2 years (W24). Direct additive genetic and residual random effects were included in all the traits. Maternal permanent environmental and maternal additive genetic effects were included for WW and W12. The fixed effects were: contemporary group (for all traits), sex (for WW, W12, W18, and W24), parity (for WW, W12, and MY270). Age was included as covariate for WW, W12, W18 and W24. Principal component analysis (PCA) was conducted using the genetic values of 133 breeding males whose breeding-value reliability was higher than 50% for all the traits in order to define the number of principal components (PC) which would explain most of the variation. The highest heritabilities were for W18 and MY270, and the lowest for AFC; with 0.53, 0.23, and 0.17, respectively. The first three PCs represented 66% of the total variance. Correlation of the first PC with meat production traits was higher than 0.73, and it was -0.38 with AFC. Correlations of the second PC with maternal genetic component traits for WW and W12 were above 0.75. The third PC had 0.84 correlation with MY270. PCA is an alternative approach for analyzing traits in dual-purpose buffaloes and reduces the dimension of the traits. PMID:26230093

  14. Genetic Evaluation of Dual-Purpose Buffaloes (Bubalus bubalis) in Colombia Using Principal Component Analysis.

    PubMed

    Agudelo-Gómez, Divier; Pineda-Sierra, Sebastian; Cerón-Muñoz, Mario Fernando

    2015-01-01

    Genealogy and productive information of 48621 dual-purpose buffaloes born in Colombia between years 1996 and 2014 was used. The following traits were assessed using one-trait models: milk yield at 270 days (MY270), age at first calving (AFC), weaning weight (WW), and weights at the following ages: first year (W12), 18 months (W18), and 2 years (W24). Direct additive genetic and residual random effects were included in all the traits. Maternal permanent environmental and maternal additive genetic effects were included for WW and W12. The fixed effects were: contemporary group (for all traits), sex (for WW, W12, W18, and W24), parity (for WW, W12, and MY270). Age was included as covariate for WW, W12, W18 and W24. Principal component analysis (PCA) was conducted using the genetic values of 133 breeding males whose breeding-value reliability was higher than 50% for all the traits in order to define the number of principal components (PC) which would explain most of the variation. The highest heritabilities were for W18 and MY270, and the lowest for AFC; with 0.53, 0.23, and 0.17, respectively. The first three PCs represented 66% of the total variance. Correlation of the first PC with meat production traits was higher than 0.73, and it was -0.38 with AFC. Correlations of the second PC with maternal genetic component traits for WW and W12 were above 0.75. The third PC had 0.84 correlation with MY270. PCA is an alternative approach for analyzing traits in dual-purpose buffaloes and reduces the dimension of the traits. PMID:26230093

  15. The 2008 Super Tuesday Tornado Outbreak: Synthetic Dual Doppler Analysis of Contrasting Tornadic Storm Types

    NASA Technical Reports Server (NTRS)

    Knupp, Kevin R.; Coleman, Timothy; Carey, Larry; Peterson, Walt; Elkins, Calvin

    2008-01-01

    During the Super Tuesday Tornado Outbreak on 5-6 February, a significant number of storms passed within about 40 km of WSR-88D radars. This distance, combined with the significant motion vector (from the southwest at 20-25 m per second) of relatively steady storms, is amenable to a synthetic dual Doppler analysis during the times when the storms passed the WSR-88D locations. Nine storms will be analyzed using the SDD technique. The following table provides their general characteristics and nearest approach to the 88D radars. For this data set, storm structure ranges from isolated supercell to QLCS. Each storm will be analyzed for a 40-60 min period during passage by the WSR-88D radar to determine general storm properties. Analysis of high-resolution single Doppler data around the time of passage (plus or minus 30 min), combined with 1-2 SDD analyses, will be used to examine the kinematic structure of low-level circulations (e.g., mesocyclone, downdraft) and the relation to the parent storm. This analysis may provide insights on the fundamental differences between cyclonic circulations in supercell storms and those within QCLS's.

  16. Microcomputer digitizing system for dual use in applications of remote sensing and microscopic image analysis

    SciTech Connect

    McHone, J.G.

    1988-08-01

    A new image-analysis laboratory is being developed with equipment that has dual use for the interpretation and classification of satellite and air-photo images, and also for classification and automated measurement of minerals and textures in thin sections of rocks. Digitizing techniques for all the applications utilize input from a nine-track tape drive or from monochromatic television cameras on a microscope and a camera stand. The microcomputer contains a TV frame grabber and a graphics board that develops 512 by 512 by 32 bit images on a high-resolution color monitor. Output devices include the tape and disk drives, a color ink-jet printer, and a photographic film copier. A large digitizing board, a large-screen monitor, and a plotter are attached for computer-aided drafting. Several software packages are being integrated and modified for the analysis work. The software routines for image enhancement, annotation, measurement of areas, and classification by pixel characteristics are common to both remote sensing and microscopic analysis. The system is a cost-effective way to combine studies of tectonic patterns, structural surface features, and rock and vegetation types using remote images, with grain size, shape, identification, and porosity measurements of the rocks themselves.

  17. Large space antennas: A systems analysis case history

    NASA Technical Reports Server (NTRS)

    Keafer, Lloyd S. (Compiler); Lovelace, U. M. (Compiler)

    1987-01-01

    The value of systems analysis and engineering is aptly demonstrated by the work on Large Space Antennas (LSA) by the NASA Langley Spacecraft Analysis Branch. This work was accomplished over the last half-decade by augmenting traditional system engineering, analysis, and design techniques with computer-aided engineering (CAE) techniques using the Langley-developed Interactive Design and Evaluation of Advanced Spacecraft (IDEAS) system. This report chronicles the research highlights and special systems analyses that focused the LSA work on deployable truss antennas. It notes developmental trends toward greater use of CAE techniques in their design and analysis. A look to the future envisions the application of improved systems analysis capabilities to advanced space systems such as an advanced space station or to lunar and Martian missions and human habitats.

  18. Generalized DQE analysis of radiographic and dual-energy imaging using flat-panel detectors

    SciTech Connect

    Richard, S.; Siewerdsen, J.H.; Jaffray, D.A.; Moseley, D.J.; Bakhtiar, B.

    2005-05-01

    Analysis of detective quantum efficiency (DQE) is an important component of the investigation of imaging performance for flat-panel detectors (FPDs). Conventional descriptions of DQE are limited, however, in that they take no account of anatomical noise (i.e., image fluctuations caused by overlying anatomy), even though such noise can be the most significant limitation to detectability, often outweighing quantum or electronic noise. We incorporate anatomical noise in experimental and theoretical descriptions of the 'generalized DQE' by including a spatial-frequency-dependent noise-power term, S{sub B}, corresponding to background anatomical fluctuations. Cascaded systems analysis (CSA) of the generalized DQE reveals tradeoffs between anatomical noise and the factors that govern quantum noise. We extend such analysis to dual-energy (DE) imaging, in which the overlying anatomical structure is selectively removed in image reconstructions by combining projections acquired at low and high kVp. The effectiveness of DE imaging in removing anatomical noise is quantified by measurement of S{sub B} in an anthropomorphic phantom. Combining the generalized DQE with an idealized task function to yield the detectability index, we show that anatomical noise dramatically influences task-based performance, system design, and optimization. For the case of radiography, the analysis resolves a fundamental and illustrative quandary: The effect of kVp on imaging performance, which is poorly described by conventional DQE analysis but is clarified by consideration of the generalized DQE. For the case of DE imaging, extension of a generalized CSA methodology reveals a potentially powerful guide to system optimization through the optimal selection of the tissue cancellation parameter. Generalized task-based analysis for DE imaging shows an improvement in the detectability index by more than a factor of 2 compared to conventional radiography for idealized detection tasks.

  19. Probabilistic structural analysis methods for space propulsion system components

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1986-01-01

    The development of a three-dimensional inelastic analysis methodology for the Space Shuttle main engine (SSME) structural components is described. The methodology is composed of: (1) composite load spectra, (2) probabilistic structural analysis methods, (3) the probabilistic finite element theory, and (4) probabilistic structural analysis. The methodology has led to significant technical progress in several important aspects of probabilistic structural analysis. The program and accomplishments to date are summarized.

  20. Probabilistic structural analysis methods for space propulsion system components

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.

    1987-01-01

    The development of a three-dimensional inelastic analysis methodology for the Space Shuttle main engine (SSME) structural components is described. The methodology is composed of: (1) composite load spectra, (2) probabilistic structural analysis methods, (3) the probabilistic finite element theory, and (4) probabilistic structural analysis. The methodology has led to significant technical progress in several important aspects of probabilistic structural analysis. The program and accomplishments to date are summarized.

  1. An Analysis of the Psychometric Properties of Dual Language Test Forms.

    ERIC Educational Resources Information Center

    Sireci, Stephen G.; Khaliq, Shameem Nyla

    Many students in the United States who are required to take educational tests are not fully proficient in English. To address this problem, a state-mandated testing program created dual language English-Spanish versions of some of their tests. In this study, the psychometric properties of the English and dual language versions of a fourth-grade…

  2. Developing Dual Polarization Applications For 45th Weather Squadron's (45 WS) New Weather Radar: A Cooperative Project With The National Space Science and Technology Center (NSSTC)

    NASA Technical Reports Server (NTRS)

    Roeder, W.P.; Peterson, W.A.; Carey, L.D.; Deierling, W.; McNamara, T.M.

    2009-01-01

    A new weather radar is being acquired for use in support of America s space program at Cape Canaveral Air Force Station, NASA Kennedy Space Center, and Patrick AFB on the east coast of central Florida. This new radar includes dual polarization capability, which has not been available to 45 WS previously. The 45 WS has teamed with NSSTC with funding from NASA Marshall Spaceflight Flight Center to improve their use of this new dual polarization capability when it is implemented operationally. The project goals include developing a temperature profile adaptive scan strategy, developing training materials, and developing forecast techniques and tools using dual polarization products. The temperature profile adaptive scan strategy will provide the scan angles that provide the optimal compromise between volume scan rate, vertical resolution, phenomena detection, data quality, and reduced cone-of-silence for the 45 WS mission. The mission requirements include outstanding detection of low level boundaries for thunderstorm prediction, excellent vertical resolution in the atmosphere electrification layer between 0 C and -20 C for lightning forecasting and Lightning Launch Commit Criteria evaluation, good detection of anvil clouds for Lightning Launch Commit Criteria evaluation, reduced cone-of-silence, fast volume scans, and many samples per pulse for good data quality. The training materials will emphasize the appropriate applications most important to the 45 WS mission. These include forecasting the onset and cessation of lightning, forecasting convective winds, and hopefully the inference of electrical fields in clouds. The training materials will focus on annotated radar imagery based on products available to the 45 WS. Other examples will include time sequenced radar products without annotation to simulate radar operations. This will reinforce the forecast concepts and also allow testing of the forecasters. The new dual polarization techniques and tools will focus on

  3. Analysis of space telescope data collection system

    NASA Technical Reports Server (NTRS)

    Ingels, F. M.; Schoggen, W. O.

    1982-01-01

    An analysis of the expected performance for the Multiple Access (MA) system is provided. The analysis covers the expected bit error rate performance, the effects of synchronization loss, the problem of self-interference, and the problem of phase ambiguity. The problem of false acceptance of a command word due to data inversion is discussed. A mathematical determination of the probability of accepting an erroneous command word due to a data inversion is presented. The problem is examined for three cases: (1) a data inversion only, (2) a data inversion and a random error within the same command word, and a block (up to 256 48-bit words) containing both a data inversion and a random error.

  4. Reduced variational space analysis of methane adducts

    SciTech Connect

    Cundari, T.R.; Klinckman, T.R.

    1998-10-05

    Methane is the major component of natural gas, and hence its catalytic conversion to functionalized products (e.g., methanol) is of great interest. A variety of transition metal complexes have been investigated experimentally for the selective activation of methane. Recent experiments and computations suggest that weakly bound methane adducts play a pivotal role in metal-mediated methane activation. Calculation of the intrinsic reaction coordinates for methane activation by d{sup 0} imidos indicates that the adduct lies along the pathway for methane activation. Isolation of a stable methane adduct, suitable for experimental characterization, would be aided by a greater understanding of their chemistry. Given the short-lived nature of these adducts and the limited direct experimental information, computational chemistry is a useful tool for understanding the bonding and structure of these catalytic intermediates. This research investigated the bonding forces in methane adducts of transition metal (TM) complexes. The calculations reported here employed effective core potential (ECP) methods within the Hartree-Fock approximation using the GAMESS quantum chemistry program. The reduced variational space self-consistent field (RVS-SCF) method developed by Stevens and Fink was employed. This technique was used to analyze the Coulomb and exchange energy (CEX), polarization energy (POL), and charge transfer energy (CT) contributions to the binding energy ({Delta}E{sub add}) of methane to a TM complex. Adducts of high-valent (d{sup 0}) transition metal complexes were studied. The role of metal, ligand, and charge on the different contributions to the binding energy were analyzed.

  5. Coupled Loads Analysis Accuracy from the Space Vehicle Perspective

    NASA Astrophysics Data System (ADS)

    Dickens, J. M.; Wittbrodt, M. J.; Gate, M. M.; Li, L. H.; Stroeve, A.

    2001-01-01

    Coupled loads analysis (CLA) consists of performing a structural response analysis, usually a time-history response analysis, with reduced dynamic models typically provided by two different companies to obtain the coupled response of a launch vehicle and space vehicle to the launching and staging events required to place the space vehicle into orbit. The CLA is performed by the launch vehicle contractor with a reduced dynamics mathematical model that is coupled to the launch vehicle, or booster, model to determine the coupled loads for each substructure. Recently, the booster and space vehicle contractors have been from different countries. Due to the language differences and governmental restrictions, the verification of the CLA is much more difficult than when working with launch vehicle and space vehicle contractors of the same country. This becomes exceedingly clear when the CLA analysis results do not seem to pass an intuitive judgement. Presented in the sequel are three checks that a space vehicle contractor can perform on the results of a coupled loads analysis to partially verify the analysis.

  6. Single-cell analysis reveals gene-expression heterogeneity in syntrophic dual-culture of Desulfovibrio vulgaris with Methanosarcina barkeri

    NASA Astrophysics Data System (ADS)

    Qi, Zhenhua; Pei, Guangsheng; Chen, Lei; Zhang, Weiwen

    2014-12-01

    Microbial syntrophic metabolism has been well accepted as the heart of how methanogenic and other anaerobic microbial communities function. In this work, we applied a single-cell RT-qPCR approach to reveal gene-expression heterogeneity in a model syntrophic system of Desulfovibrio vulgaris and Methanosarcina barkeri, as compared with the D. vulgaris monoculture. Using the optimized primers and single-cell analytical protocol, we quantitatively determine gene-expression levels of 6 selected target genes in each of the 120 single cells of D. vulgaris isolated from its monoculture and dual-culture with M. barkeri. The results demonstrated very significant cell-to-cell gene-expression heterogeneity for the selected D. vulgaris genes in both the monoculture and the syntrophic dual-culture. Interestingly, no obvious increase in gene-expression heterogeneity for the selected genes was observed for the syntrophic dual-culture when compared with its monoculture, although the community structure and cell-cell interactions have become more complicated in the syntrophic dual-culture. In addition, the single-cell RT-qPCR analysis also provided further evidence that the gene cluster (DVU0148-DVU0150) may be involved syntrophic metabolism between D. vulgaris and M. barkeri. Finally, the study validated that single-cell RT-qPCR analysis could be a valuable tool in deciphering gene functions and metabolism in mixed-cultured microbial communities.

  7. New space sensor and mesoscale data analysis

    NASA Technical Reports Server (NTRS)

    Hickey, John S.

    1987-01-01

    The developed Earth Science and Application Division (ESAD) system/software provides the research scientist with the following capabilities: an extensive data base management capibility to convert various experiment data types into a standard format; and interactive analysis and display package (AVE80); an interactive imaging/color graphics capability utilizing the Apple III and IBM PC workstations integrated into the ESAD computer system; and local and remote smart-terminal capability which provides color video, graphics, and Laserjet output. Recommendations for updating and enhancing the performance of the ESAD computer system are listed.

  8. Manufacturing in space: Fluid dynamics numerical analysis

    NASA Technical Reports Server (NTRS)

    Robertson, S. J.; Nicholson, L. A.; Spradley, L. W.

    1981-01-01

    Natural convection in a spherical container with cooling at the center was numerically simulated using the Lockheed-developed General Interpolants Method (GIM) numerical fluid dynamic computer program. The numerical analysis was simplified by assuming axisymmetric flow in the spherical container, with the symmetry axis being a sphere diagonal parallel to the gravity vector. This axisymmetric spherical geometry was intended as an idealization of the proposed Lal/Kroes growing experiments to be performed on board Spacelab. Results were obtained for a range of Rayleigh numbers from 25 to 10,000. For a temperature difference of 10 C from the cooling sting at the center to the container surface, and a gravitional loading of 0.000001 g a computed maximum fluid velocity of about 2.4 x 0.00001 cm/sec was reached after about 250 sec. The computed velocities were found to be approximately proportional to the Rayleigh number over the range of Rayleigh numbers investigated.

  9. Energy loss analysis of an integrated space power distribution system

    NASA Technical Reports Server (NTRS)

    Kankam, M. D.; Ribeiro, P. F.

    1992-01-01

    The results of studies related to conceptual topologies of an integrated utility-like space power system are described. The system topologies are comparatively analyzed by considering their transmission energy losses as functions of mainly distribution voltage level and load composition. The analysis is expedited by use of a Distribution System Analysis and Simulation (DSAS) software. This recently developed computer program by the Electric Power Research Institute (EPRI) uses improved load models to solve the power flow within the system. However, present shortcomings of the software with regard to space applications, and incompletely defined characteristics of a space power system make the results applicable to only the fundamental trends of energy losses of the topologies studied. Accountability, such as included, for the effects of the various parameters on the system performance can constitute part of a planning tool for a space power distribution system.

  10. Design and analysis of the Gemini chain system in dual clutch transmission of automobile

    NASA Astrophysics Data System (ADS)

    Cheng, Yabing; Guo, Haitao; Fu, Zhenming; Wan, Nen; Li, Lei; Wang, Yang

    2015-01-01

    Chain drive system is widely used in the conditions of high-speed, overload, variable speed and load. Many studies are focused on the meshing theory and wear characteristics of chain drive system, but system design, analysis, and noise characteristics of the chain drive system are weak. System design and noise characteristic are studied for a new type Gemini chain of dual-clutch automatic transmission. Based on the meshing theory of silent chain, the design parameters of the Gemini chain system are calculated and the mathematical models and dynamic analysis models of the Gemini chain system are established. Dynamic characteristics of the Gemini chain system is simulated and the contact force of plate and pin, plate and sprockets, the chain tension forces, the transmission error and the stress of plates and pins are analyzed. According to the simulation results of the Gemini chain system, the noise experiment about system is carried out. The noise values are tested at different speed and load and spectral characteristics are analyzed. The results of simulation and experimental show that the contact forces of plate and pin, plate and sprockets are smaller than the allowable stress values, the chain tension force is less than ultimate tension and transmission error is limited in 1.2%. The noise values can meet the requirements of industrial design, and it is proved that the design and analysis method of the Gemini chain system is scientific and feasible. The design and test system is built from analysis to test of Gemini chain system. This research presented will provide a corresponding theoretical guidance for the design and dynamic characteristics and noise characteristics of chain drive system.

  11. Physical analysis of breast cancer using dual-source computed tomography

    NASA Astrophysics Data System (ADS)

    Kim, H. J.; Lee, H. K.; Cho, J. H.

    2014-12-01

    This study was aimed to analyze various physical characteristics of breast cancer using dual-source computed tomography (CT). A phantom study and a clinical trial were performed in order and a 64-multidetector CT device was used for the examinations. In the phantom study, single-source (SS) CT was set up with a conventional scanning condition that is usually applied for breast CT examination and implementation was done at tube voltage of 120 kVp. Dual-source CT acquired images by irradiating X-ray sources with fast switching between two kilovoltage settings (80 and 140 kVp). After scanning, Hounsfield Unit (HU) values and radiation doses in a region of interest were measured and analyzed. In the clinical trial, the HU values were measured and analyzed after single-source computed tomography (SSCT) and dual-source CT in patients diagnosed with breast cancer. Also, the tumor size measured by dual-source CT was compared with the actual tumor size. The phantom study determined that the tumor region was especially measured by dual-source CT, while nylon fiber and specks region were especially measured by SSCT. The radiation dose was high with dual-source CT. The clinical trial showed a higher HU value of cancerous regions when scanned by dual-source CT compared with SSCT.

  12. Results and Analysis from Space Suit Joint Torque Testing

    NASA Technical Reports Server (NTRS)

    Matty, Jennifer

    2010-01-01

    This joint mobility KC lecture included information from two papers, "A Method for and Issues Associated with the Determination of Space Suit Joint Requirements" and "Results and Analysis from Space Suit Joint Torque Testing," as presented for the International Conference on Environmental Systems in 2009 and 2010, respectively. The first paper discusses historical joint torque testing methodologies and approaches that were tested in 2008 and 2009. The second paper discusses the testing that was completed in 2009 and 2010.

  13. Partial pressure analysis in space testing

    NASA Technical Reports Server (NTRS)

    Tilford, Charles R.

    1994-01-01

    For vacuum-system or test-article analysis it is often desirable to know the species and partial pressures of the vacuum gases. Residual gas or Partial Pressure Analyzers (PPA's) are commonly used for this purpose. These are mass spectrometer-type instruments, most commonly employing quadrupole filters. These instruments can be extremely useful, but they should be used with caution. Depending on the instrument design, calibration procedures, and conditions of use, measurements made with these instruments can be accurate to within a few percent, or in error by two or more orders of magnitude. Significant sources of error can include relative gas sensitivities that differ from handbook values by an order of magnitude, changes in sensitivity with pressure by as much as two orders of magnitude, changes in sensitivity with time after exposure to chemically active gases, and the dependence of the sensitivity for one gas on the pressures of other gases. However, for most instruments, these errors can be greatly reduced with proper operating procedures and conditions of use. In this paper, data are presented illustrating performance characteristics for different instruments and gases, operating parameters are recommended to minimize some errors, and calibrations procedures are described that can detect and/or correct other errors.

  14. Protective Effect of Dual-Strain Probiotics in Preterm Infants: A Multi-Center Time Series Analysis

    PubMed Central

    Schwab, Frank; Garten, Lars; Geffers, Christine; Gastmeier, Petra; Piening, Brar

    2016-01-01

    Objective To determine the effect of dual-strain probiotics on the development of necrotizing enterocolitis (NEC), mortality and nosocomial bloodstream infections (BSI) in preterm infants in German neonatal intensive care units (NICUs). Design A multi-center interrupted time series analysis. Setting 44 German NICUs with routine use of dual-strain probiotics on neonatal ward level. Patients Preterm infants documented by NEO-KISS, the German surveillance system for nosocomial infections in preterm infants with birth weights below 1,500 g, between 2004 and 2014. Intervention Routine use of dual-strain probiotics containing Lactobacillus acidophilus and Bifidobacterium spp. (Infloran) on the neonatal ward level. Main outcome measures Incidences of NEC, overall mortality, mortality following NEC and nosocomial BSI. Results Data from 10,890 preterm infants in 44 neonatal wards was included in this study. Incidences of NEC and BSI were 2.5% (n = 274) and 15.0%, (n = 1631), respectively. Mortality rate was 6.1% (n = 665). The use of dual-strain probiotics significantly reduced the risk of NEC (HR = 0.48; 95% CI = 0.38–0.62), overall mortality (HR = 0.60, 95% CI = 0.44–0.83), mortality after NEC (HR = 0.51, 95% CI = 0.26–0.999) and nosocomial BSI (HR = 0.89, 95% CI = 0.81–0.98). These effects were even more pronounced in the subgroup analysis of preterm infants with birth weights below 1,000 g. Conclusion In order to reduce NEC and mortality in preterm infants, it is advisable to add routine prophylaxis with dual-strain probiotics to clinical practice in neonatal wards. PMID:27332554

  15. A single- and a dual-fractal analysis of antigen-antibody binding kinetics for different biosensor applications.

    PubMed

    Sadana, A

    1999-06-30

    The diffusion-limited binding kinetics of antigen (or antibody) in solution to antibody (or antigen) immobilized on a biosensor surface is analyzed within a fractal framework. The data is adequately described by a single- or a dual-fractal analysis. Initially, the data was modelled by a single-fractal analysis. If an inadequate fit was obtained then a dual-fractal analysis was utilized. The regression analysis provided by Sigmaplot, 1993 (Scientific Graphing Software: User's Manual. Jandel Scientific, San Rafael, CA) was utilized to determine if a single-fractal analysis is sufficient, or a dual-fractal analysis is required. In general, it is of interest to note that the binding rate coefficient and the fractal dimension exhibit changes in the same direction (except for a single example) for the antigen-antibody systems analyzed. Binding rate coefficient expressions as a function of the fractal dimension developed for the antigen-antibody binding systems indicate a high sensitivity of the binding rate coefficient on the fractal dimension when both a single -as well as a dual-fractal analysis is used. For example, for a single-fractal analysis and for the binding of human endothelin-1 (ET-1) antibody in solution to ET-1(15-21) x BSA (bovine serum albumin) immobilised on a surface plasmon resonance surface, the order of dependence of the binding rate coefficient, k on the fractal dimension, Df is 7.0945. Similarly, for a dual-fractal analysis and for the binding of parasite L. donovani diluted pooled sera in solution to fluorescein isothiocyanate-labeled anti-human immunoglobulin IgG immobilized on an optical fibre, the order of dependence of k1 and k2 on Df1 and Df2 were 6.8018 and -4.393, respectively. Binding rate coefficient expressions are also developed as a function of the analyte (antigen or antibody) concentration in solution. The binding rate coefficient expressions developed as a function of the fractal dimension(s) are of particular value since they

  16. A Single and a Dual-Fractal Analysis of Analyte-Receptor Binding Kinetics for Surface Plasmon Resonance Biosensor Applications.

    PubMed

    Ramakrishnan; Sadana

    1999-05-15

    The diffusion-limited binding kinetics of analyte in solution to either a receptor immobilized on a surface or to a receptorless surface is analyzed within a fractal framework for a surface plasmon resonance biosensor. The data is adequately described by a single- or a dual-fractal analysis. Initially, the data was modeled by a single-fractal analysis. If an inadequate fit was obtained then a dual-fractal analysis was utilized. The regression analysis provided by Sigmaplot (32) was used to determine if a single fractal analysis is sufficient or if a dual-fractal analysis is required. In general, it is of interest to note that the binding rate coefficient and the fractal dimension exhibit changes in the same direction (except for a single example) for the analyte-receptor systems analyzed. Binding rate coefficient expressions as a function of the fractal dimension developed for the analyte-receptor binding systems indicate, in general, the high sensitivity of the binding rate coefficient on the fractal dimension when both a single- and a dual-fractal analysis is used. For example, for a single-fractal analysis and for the binding of human endothelin-1 (ET-1) antibody in solution to ET-115-21.BSA immobilized on a surface plasmon resonance (SPR) surface (33), the order of dependence of the binding rate coefficient, k, on the fractal dimension, Df, is 6.4405. Similarly, for a dual-fractal analysis and for the binding of 10(-6) to 10(-4) M bSA in solution to a receptorless surface (direct binding to SPR surface) (41) the order of dependence of k1 and k2 on Df1 and Df2 were -2.356 and 6.241, respectively. Binding rate coefficient expressions are also developed as a function of the analyte concentration in solution. The binding rate coefficient expressions developed as a function of the fractal dimension(s) are of particular value since they provide a means to better control SPR biosensor performance by linking it to the degree of heterogeneity that exists on the SPR

  17. Dynamic characterization and analysis of space shuttle SRM solid propellant

    NASA Technical Reports Server (NTRS)

    Hufferd, W. L.

    1979-01-01

    The dynamic response properties of the space shuttle solid rocket moter (TP-H1148) propellant were characterized and the expected limits of propellant variability were established. Dynamic shear modulus tests conducted on six production batches of TP-H1148 at various static and dynamic strain levels over the temperature range from 40 F to 90 F. A heat conduction analysis and dynamic response analysis of the space shuttle solid rocket motor (SRM) were also conducted. The dynamic test results show significant dependence on static and dynamic strain levels and considerable batch-to-batch and within-batch variability. However, the results of the SRM dynamic response analyses clearly demonstrate that the stiffness of the propellant has no consequential on the overall SRM dynamic response. Only the mass of the propellant needs to be considered in the dynamic analysis of the space shuttle SRM.

  18. Method of moments analysis of displaced-axis dual reflector antennas

    NASA Astrophysics Data System (ADS)

    Vered, Nissan

    1992-03-01

    Small symmetric dual reflector antennas suffer from low efficiency due to subreflector blockage of the main reflector and subreflector scattering. These can be reduced by slicing the main dish and translating its rotational axis, along with modifying the subreflector geometry. This type of design is usually applied to low-frequency reflectors, but high-frequency analysis techniques are used. Consequently the agreement between measured and computed data is not good as it would be for rigorous solution such as the method of moments. This thesis modifies an existing method of moments computer code to handle the displaced axis geometry, and computes the radiation pattern and the efficiency of this antenna as a function of geometrical and electrical design parameters. Optimum configurations are identified for several feed types. The paraboloidal antenna with a feed at the focus does not allow much control of the power distribution over the aperture surface, except for what can be accomplished by changing the focal length and feed pattern.

  19. Design and analysis of inverted H shape dual band patch antenna for microwave application

    NASA Astrophysics Data System (ADS)

    Ullah, M. Habib; Islam, M. T.; Mandeep, J. S.; Misran, N.; Reaz, M. B. I.

    2013-04-01

    Design and analysis of an inverted H shape printed dual band patch antenna has been presented in this paper. The proposed antenna has designed by 3-D full wave high frequency electromagnetic simulator HFSS and printed in low cost, durable epoxy polymer resin composite material substrate. The printed antenna prototype has been measured in a standard far field anechoic electromagnetic field measurement chamber. The measured results have analyzed by using computer aided plotting tool OriginPro 8.5. Measured -10 dB return loss bandwidth 3.25 GHz from 9.75 GHz to 13 GHz with peak gain 8.5 dBi have been achieved. The proposed antenna has obtained 0.63 dBi gain with 96% efficiency at lower band 10.3 GHz and 6.03 dBi gain with 84.2% efficiency at upper band 12.5 GHz. The almost steady radiation pattern makes the proposed antenna appropriate for part of X and Ku band applications. Moreover, the input impedance and current distribution along the radiating patch of the proposed antenna have also been analyzed in this paper.

  20. Dual Recovery among People with Serious Mental Illnesses and Substance Problems: A Qualitative Analysis

    PubMed Central

    Green, Carla A.; Yarborough, Micah T.; Polen, Michael R.; Janoff, Shannon L.; Yarborough, Bobbi Jo H.

    2014-01-01

    Objective Individuals with serious mental illnesses are more likely to have substance-related problems than those without mental health problems. They also face more difficult recovery trajectories as they cope with dual disorders. Nevertheless, little is known about individuals’ perspectives regarding their dual recovery experiences. Methods This qualitative analysis was conducted as part of an exploratory mixed-methods study of mental health recovery. Members of Kaiser Permanente Northwest (a group-model, not-for-profit, integrated health plan) who had serious mental illness diagnoses were interviewed four times over two years about factors affecting their mental health recovery. Interviews were recorded, transcribed, and coded with inductively-derived codes. Themes were identified by reviewing text coded “alcohol or other drugs.” Results Participants (N = 177) were diagnosed with schizophrenia/schizoaffective disorder (n = 75, 42%), bipolar I/II disorder (n = 84, 48%), or affective psychosis (n = 18, 10%). At baseline, 63% (n = 112) spontaneously described addressing substance use as part of their mental health recovery. When asked at follow-up, 97% (n = 171) provided codeable answers about substances and mental health. We identified differing pathways to recovery, including through formal treatment, self-help groups or peer support, “natural” recovery (without the help of others), and continued but controlled use of alcohol. We found three overarching themes in participants’ experiences of recovering from serious mental illnesses and substance-related problems: Learning about the effects of alcohol and drugs provided motivation and a foundation for sobriety; achieving sobriety helped people to initiate their mental health recovery processes; and achieving and maintaining sobriety built self-efficacy, self-confidence, improved functioning and a sense of personal growth. Non-judgmental support from clinicians adopting chronic disease approaches also

  1. Dual-Tracer PET Using Generalized Factor Analysis of Dynamic Sequences

    PubMed Central

    Fakhri, Georges El; Trott, Cathryn M.; Sitek, Arkadiusz; Bonab, Ali; Alpert, Nathaniel M.

    2013-01-01

    Purpose With single-photon emission computed tomography, simultaneous imaging of two physiological processes relies on discrimination of the energy of the emitted gamma rays, whereas the application of dual-tracer imaging to positron emission tomography (PET) imaging has been limited by the characteristic 511-keV emissions. Procedures To address this limitation, we developed a novel approach based on generalized factor analysis of dynamic sequences (GFADS) that exploits spatio-temporal differences between radiotracers and applied it to near-simultaneous imaging of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) (brain metabolism) and 11C-raclopride (D2) with simulated human data and experimental rhesus monkey data. We show theoretically and verify by simulation and measurement that GFADS can separate FDG and raclopride measurements that are made nearly simultaneously. Results The theoretical development shows that GFADS can decompose the studies at several levels: (1) It decomposes the FDG and raclopride study so that they can be analyzed as though they were obtained separately. (2) If additional physiologic/anatomic constraints can be imposed, further decomposition is possible. (3) For the example of raclopride, specific and nonspecific binding can be determined on a pixel-by-pixel basis. We found good agreement between the estimated GFADS factors and the simulated ground truth time activity curves (TACs), and between the GFADS factor images and the corresponding ground truth activity distributions with errors less than 7.3±1.3 %. Biases in estimation of specific D2 binding and relative metabolism activity were within 5.9±3.6 % compared to the ground truth values. We also evaluated our approach in simultaneous dual-isotope brain PET studies in a rhesus monkey and obtained accuracy of better than 6 % in a mid-striatal volume, for striatal activity estimation. Conclusions Dynamic image sequences acquired following near-simultaneous injection of two PET radiopharmaceuticals

  2. Multi-species trace gas analysis with dual-wavelength quantum cascade laser

    NASA Astrophysics Data System (ADS)

    Jágerská, Jana; Tuzson, Béla; Looser, Herbert; Jouy, Pierre; Hugi, Andreas; Mangold, Markus; Soltic, Patrik; Faist, Jérôme; Emmenegger, Lukas

    2015-04-01

    Simultaneous detection of multiple gas species using mid-IR laser spectroscopy is highly appealing for a large variety of applications ranging from air quality monitoring, medical breath analysis to industrial process control. However, state-of-the-art distributed-feedback (DFB) mid-IR lasers are usually tunable only within a narrow spectral range, which generally leads to one-laser-one-compound measurement strategy. Thus, multi-species detection involves several lasers and elaborate beam combining solutions [1]. This makes them bulky, costly, and highly sensitive to optical alignment, which limits their field deployment. In this paper, we explore an alternative measurement concept based on a dual-wavelength quantum cascade laser (DW-QCL) [2]. Such a laser can emit at two spectrally distinct wavelengths using a succession of two DFB gratings with different periodicities and a common waveguide to produce one output beam. The laser design was optimized for NOx measurements and correspondingly emits single-mode at 5.26 and 6.25 μm. Electrical separation of the respective laser sections makes it possible to address each wavelength independently. Thereby, it is possible to detect NO and NO2 species with one laser using the same optical path, without any beam combining optics, i.e. in a compact and cost-efficient single-path optical setup. Operated in a time-division multiplexed mode, the spectrometer reaches detection limits at 100 s averaging of 0.5 and 1.5 ppb for NO2 and NO, respectively. The performance of the system was validated against the well-established chemiluminescence detection while measuring the NOx emissions on an automotive test-bench, as well as monitoring the pollution at a suburban site. [1] B. Tuzson, K. Zeyer, M. Steinbacher, J. B. McManus, D. D. Nelson, M. S. Zahniser, and L. Emmenegger, 'Selective measurements of NO, NO2 and NOy in the free troposphere using quantum cascade laser spectroscopy,' Atmospheric Measurement Techniques 6, 927-936 (2013

  3. Analysis of In-Space Assembly of Modular Systems

    NASA Technical Reports Server (NTRS)

    Moses, Robert W.; VanLaak, James; Johnson, Spencer L.; Chytka, Trina M.; Reeves, John D.; Todd, B. Keith; Moe, Rud V.; Stambolian, Damon B.

    2005-01-01

    Early system-level life cycle assessments facilitate cost effective optimization of system architectures to enable implementation of both modularity and in-space assembly, two key Exploration Systems Research & Technology (ESR&T) Strategic Challenges. Experiences with the International Space Station (ISS) demonstrate that the absence of this rigorous analysis can result in increased cost and operational risk. An effort is underway, called Analysis of In-Space Assembly of Modular Systems, to produce an innovative analytical methodology, including an evolved analysis toolset and proven processes in a collaborative engineering environment, to support the design and evaluation of proposed concepts. The unique aspect of this work is that it will produce the toolset, techniques and initial products to analyze and compare the detailed, life cycle costs and performance of different implementations of modularity for in-space assembly. A multi-Center team consisting of experienced personnel from the Langley Research Center, Johnson Space Center, Kennedy Space Center, and the Goddard Space Flight Center has been formed to bring their resources and experience to this development. At the end of this 30-month effort, the toolset will be ready to support the Exploration Program with an integrated assessment strategy that embodies all life-cycle aspects of the mission from design and manufacturing through operations to enable early and timely selection of an optimum solution among many competing alternatives. Already there are many different designs for crewed missions to the Moon that present competing views of modularity requiring some in-space assembly. The purpose of this paper is to highlight the approach for scoring competing designs.

  4. Scanning Tunneling Microscopy analysis of space-exposed polymer films

    NASA Technical Reports Server (NTRS)

    Kalil, Carol R.; Young, Philip R.

    1993-01-01

    The characterization of the surface of selected space-exposed polymer films by Scanning Tunneling Microscopy (STM) is reported. Principles of STM, an emerging new technique for materials analysis, are reviewed. The analysis of several films which received up to 5.8 years of low Earth orbital (LEO) exposure onboard the NASA Long Duration Exposure Facility (LDEF) is discussed. Specimens included FEP Teflon thermal blanket material, Kapton film, and several experimental polymer films. Ultraviolet and atomic oxygen-induced crazing and erosion are described. The intent of this paper is to demonstrate how STM is enhancing the understanding of LEO space environmental effects on polymer films.

  5. Dual Credit in Oregon: An Analysis of Students Taking Dual Credit in High School in 2005-06 with Subsequent Performance in College

    ERIC Educational Resources Information Center

    Jacobs, Jonathan; North, Tom

    2008-01-01

    A dual credit course is a college/university level course that is taught at a high school, by a high school teacher, in partnership with a community college (CCWD) or Oregon University System (OUS) institution. Successful completion of a dual credit course counts as credit for both high school and college. In 2005-06, about 12,000 students took…

  6. Space Shuttle Communications Coverage Analysis for Thermal Tile Inspection

    NASA Technical Reports Server (NTRS)

    Kroll, Quin D.; Hwu, Shian U.; Upanavage, Matthew; Boster, John P.; Chavez, Mark A.

    2009-01-01

    The space shuttle ultra-high frequency Space-to-Space Communication System has to provide adequate communication coverage for astronauts who are performing thermal tile inspection and repair on the underside of the space shuttle orbiter (SSO). Careful planning and quantitative assessment are necessary to ensure successful system operations and mission safety in this work environment. This study assesses communication systems performance for astronauts who are working in the underside, non-line-of-sight shadow region on the space shuttle. All of the space shuttle and International Space Station (ISS) transmitting antennas are blocked by the SSO structure. To ensure communication coverage at planned inspection worksites, the signal strength and link margin between the SSO/ISS antennas and the extravehicular activity astronauts, whose line-of-sight is blocked by vehicle structure, was analyzed. Investigations were performed using rigorous computational electromagnetic modeling techniques. Signal strength was obtained by computing the reflected and diffracted fields along the signal propagation paths between transmitting and receiving antennas. Radio frequency (RF) coverage was determined for thermal tile inspection and repair missions using the results of this computation. Analysis results from this paper are important in formulating the limits on reliable communication range and RF coverage at planned underside inspection and repair worksites.

  7. X-framework: Space system failure analysis framework

    NASA Astrophysics Data System (ADS)

    Newman, John Steven

    Space program and space systems failures result in financial losses in the multi-hundred million dollar range every year. In addition to financial loss, space system failures may also represent the loss of opportunity, loss of critical scientific, commercial and/or national defense capabilities, as well as loss of public confidence. The need exists to improve learning and expand the scope of lessons documented and offered to the space industry project team. One of the barriers to incorporating lessons learned include the way in which space system failures are documented. Multiple classes of space system failure information are identified, ranging from "sound bite" summaries in space insurance compendia, to articles in journals, lengthy data-oriented (what happened) reports, and in some rare cases, reports that treat not only the what, but also the why. In addition there are periodically published "corporate crisis" reports, typically issued after multiple or highly visible failures that explore management roles in the failure, often within a politically oriented context. Given the general lack of consistency, it is clear that a good multi-level space system/program failure framework with analytical and predictive capability is needed. This research effort set out to develop such a model. The X-Framework (x-fw) is proposed as an innovative forensic failure analysis approach, providing a multi-level understanding of the space system failure event beginning with the proximate cause, extending to the directly related work or operational processes and upward through successive management layers. The x-fw focus is on capability and control at the process level and examines: (1) management accountability and control, (2) resource and requirement allocation, and (3) planning, analysis, and risk management at each level of management. The x-fw model provides an innovative failure analysis approach for acquiring a multi-level perspective, direct and indirect causation of

  8. Introduction to the Space Physics Analysis Network (SPAN)

    NASA Technical Reports Server (NTRS)

    Green, J. L. (Editor); Peters, D. J. (Editor)

    1985-01-01

    The Space Physics Analysis Network or SPAN is emerging as a viable method for solving an immediate communication problem for the space scientist. SPAN provides low-rate communication capability with co-investigators and colleagues, and access to space science data bases and computational facilities. The SPAN utilizes up-to-date hardware and software for computer-to-computer communications allowing binary file transfer and remote log-on capability to over 25 nationwide space science computer systems. SPAN is not discipline or mission dependent with participation from scientists in such fields as magnetospheric, ionospheric, planetary, and solar physics. Basic information on the network and its use are provided. It is anticipated that SPAN will grow rapidly over the next few years, not only from the standpoint of more network nodes, but as scientists become more proficient in the use of telescience, more capability will be needed to satisfy the demands.

  9. Tensor analysis and curvature in quantum space-time

    SciTech Connect

    Namsrai, K.

    1987-03-01

    Introducing quantum space-time into physics by means of the transformation language of noncommuting coordinates gives a simple scheme of generalizing the tensor analysis. The general covariance principle for the quantum space-time case is discussed, within which one can obtain the covariant structure of basic tensor quantities and the motion equation for a particle in a gravitational field. Definitions of covariant derivatives and curvature are also generalized in the give case. It turns out that the covariant structure of the Riemann-Christoffel curvature tensor is not preserved in quantum space-time. However, if the curvature tensor R/sub ..mu.. nu lambda chi/(z) is redetermined up to the value of the L/sup 2/ term, then its covariant structure is achieved, and it, in turn, allows them to reconstruct the Einstein equation in quantum space-time.

  10. Real-time analysis of dual-display phage immobilization and autoantibody screening using quartz crystal microbalance with dissipation monitoring

    PubMed Central

    Rajaram, Kaushik; Losada-Pérez, Patricia; Vermeeren, Veronique; Hosseinkhani, Baharak; Wagner, Patrick; Somers, Veerle; Michiels, Luc

    2015-01-01

    Over the last three decades, phage display technology has been used for the display of target-specific biomarkers, peptides, antibodies, etc. Phage display-based assays are mostly limited to the phage ELISA, which is notorious for its high background signal and laborious methodology. These problems have been recently overcome by designing a dual-display phage with two different end functionalities, namely, streptavidin (STV)-binding protein at one end and a rheumatoid arthritis-specific autoantigenic target at the other end. Using this dual-display phage, a much higher sensitivity in screening specificities of autoantibodies in complex serum sample has been detected compared to single-display phage system on phage ELISA. Herein, we aimed to develop a novel, rapid, and sensitive dual-display phage to detect autoantibodies presence in serum samples using quartz crystal microbalance with dissipation monitoring as a sensing platform. The vertical functionalization of the phage over the STV-modified surfaces resulted in clear frequency and dissipation shifts revealing a well-defined viscoelastic signature. Screening for autoantibodies using antihuman IgG-modified surfaces and the dual-display phage with STV magnetic bead complexes allowed to isolate the target entities from complex mixtures and to achieve a large response as compared to negative control samples. This novel dual-display strategy can be a potential alternative to the time consuming phage ELISA protocols for the qualitative analysis of serum autoantibodies and can be taken as a departure point to ultimately achieve a point of care diagnostic system. PMID:26316752

  11. Space construction system analysis. Part 2: Construction analysis

    NASA Technical Reports Server (NTRS)

    Roebuck, J. A.; Buck, P. A.; Gimlich, G. W.; Greenberg, H. S.; Hart, R. J.; Indrikis, J.; Lefever, A. E.; Lillenas, A. N.; Mcbaine, C. K.

    1980-01-01

    The construction methods specific to the end to end construction process for building the ETVP in low Earth orbit, using the space shuttle orbiter as a construction base, are analyzed. The analyses concerned three missions required to build the basic platform. The first mission involved performing the fabrication of beams in space and assembling the beams into a basic structural framework. The second mission was to install the forward support structure and aft support structure, the forward assembly, and a TT&C antenna. The third mission plan was to complete the construction of the platform and activate it to begin operations in low Earth orbit. The integration of the activities for each mission is described along with the construction requirements and construction logic.

  12. The Volatility of Data Space: Topology Oriented Sensitivity Analysis

    PubMed Central

    Du, Jing; Ligmann-Zielinska, Arika

    2015-01-01

    Despite the difference among specific methods, existing Sensitivity Analysis (SA) technologies are all value-based, that is, the uncertainties in the model input and output are quantified as changes of values. This paradigm provides only limited insight into the nature of models and the modeled systems. In addition to the value of data, a potentially richer information about the model lies in the topological difference between pre-model data space and post-model data space. This paper introduces an innovative SA method called Topology Oriented Sensitivity Analysis, which defines sensitivity as the volatility of data space. It extends SA into a deeper level that lies in the topology of data. PMID:26368929

  13. Daylighting and Electric Lighting Analysis for Complex Spaces

    Energy Science and Technology Software Center (ESTSC)

    1995-06-07

    SUPERLITE is a powerful lighting analysis program designed to accurately predict interior illuminance in complex building spaces due to daylight and electric lighting systems. The program enables users to model interior daylight levels for any sun and sky condition in spaces having windows, skylights or other standard fenestration systems. SUPERLITE Version 2.0 includes the capability to calculate electric lighting levels in addition to the daylighting prediction, allowing lighting performance simulation for integrated lighting systems. Themore » program calculates lighting levels on all interior surfaces, as well as on planes that can be arbitrarily positioned to represent work surfaces or other locations of interest. SUPERLITE is intended to be used by researchers and lighting designers who require detailed analysis of the illuminance distribution in architecturally complex spaces.« less

  14. Turbine blade structural dynamic analysis. [for space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Dickerson, E. O.

    1980-01-01

    The paper presents structural dynamic analysis and test results for the Space Shuttle Main Engine turbine blades. Athough these blades are designed to avoid coincidence of natural frequencies with harmonic excitation forces, the complexity of the turbine hardware, its nonlinearities and lack of information regarding the forcing function have led to fatigue failures. A comparison of single-blade analysis and test modal frequencies, shapes, and stresses is given; analysis techniques to describe the forcing function, compute dynamic responses, and incorporate the nonlinearities of Coulomb-friction dampers are presented. Recommendations are made for new research to improve forcing function computations and structural damping estimates used in the analysis.

  15. Digital processing of mesoscale analysis and space sensor data

    NASA Technical Reports Server (NTRS)

    Hickey, J. S.; Karitani, S.

    1985-01-01

    The mesoscale analysis and space sensor (MASS) data management and analysis system on the research computer system is presented. The MASS data base management and analysis system was implemented on the research computer system which provides a wide range of capabilities for processing and displaying large volumes of conventional and satellite derived meteorological data. The research computer system consists of three primary computers (HP-1000F, Harris/6, and Perkin-Elmer 3250), each of which performs a specific function according to its unique capabilities. The overall tasks performed concerning the software, data base management and display capabilities of the research computer system in terms of providing a very effective interactive research tool for the digital processing of mesoscale analysis and space sensor data is described.

  16. Analysis of orbit determination for space based optical space surveillance system

    NASA Astrophysics Data System (ADS)

    Sciré, Gioacchino; Santoni, Fabio; Piergentili, Fabrizio

    2015-08-01

    The detection capability and orbit determination performance of a space based optical observation system exploiting the visible band is analyzed. The sensor characteristics, in terms of sensitivity and resolution are those typical of present state of the art star trackers. A mathematical model of the system has been built and the system performance assessed by numerical simulation. The selection of the observer satellite's has been done in order to maximize the number of observed objects in LEO, based on a statistical analysis of the space debris population in this region. The space objects' observability condition is analyzed and two batch estimator based on the Levenberg-Marquardt and on the Powell dog-leg algorithms have been implemented and their performance compared. Both the algorithms are sensitive to the initial guess. Its influence on the algorithms' convergence is assessed, showing that the Powell dog-leg, which is a trust region method, performs better.

  17. NASA's Accident Precursor Analysis Process and the International Space Station

    NASA Technical Reports Server (NTRS)

    Groen, Frank; Lutomski, Michael

    2010-01-01

    This viewgraph presentation reviews the implementation of Accident Precursor Analysis (APA), as well as the evaluation of In-Flight Investigations (IFI) and Problem Reporting and Corrective Action (PRACA) data for the identification of unrecognized accident potentials on the International Space Station.

  18. Space Shuttle program communication and tracking systems interface analysis

    NASA Technical Reports Server (NTRS)

    Dodds, J. G.; Holmes, J. K.; Huth, G. K.; Iwasaki, R. S.; Nilsen, P. W.; Polydoros, A.; Sampaio, D. R.; Udalov, S.

    1984-01-01

    The Space Shuttle Program Communications and Tracking Systems Interface Analysis began April 18, 1983. During this time, the shuttle communication and tracking systems began flight testing. Two areas of analysis documented were a result of observations made during flight tests. These analyses involved the Ku-band communication system. First, there was a detailed analysis of the interface between the solar max data format and the Ku-band communication system including the TDRSS ground station. The second analysis involving the Ku-band communication system was an analysis of the frequency lock loop of the Gunn oscillator used to generate the transmit frequency. The stability of the frequency lock loop was investigated and changes to the design were reviewed to alleviate the potential loss of data due the loop losing lock and entering the reacquisition mode. Other areas of investigation were the S-band antenna analysis and RF coverage analysis.

  19. Application of human error analysis to aviation and space operations

    SciTech Connect

    Nelson, W.R.

    1998-03-01

    For the past several years at the Idaho National Engineering and Environmental Laboratory (INEEL) the authors have been working to apply methods of human error analysis to the design of complex systems. They have focused on adapting human reliability analysis (HRA) methods that were developed for Probabilistic Safety Assessment (PSA) for application to system design. They are developing methods so that human errors can be systematically identified during system design, the potential consequences of each error can be assessed, and potential corrective actions (e.g. changes to system design or procedures) can be identified. The primary vehicle the authors have used to develop and apply these methods has been a series of projects sponsored by the National Aeronautics and Space Administration (NASA) to apply human error analysis to aviation operations. They are currently adapting their methods and tools of human error analysis to the domain of air traffic management (ATM) systems. Under the NASA-sponsored Advanced Air Traffic Technologies (AATT) program they are working to address issues of human reliability in the design of ATM systems to support the development of a free flight environment for commercial air traffic in the US. They are also currently testing the application of their human error analysis approach for space flight operations. They have developed a simplified model of the critical habitability functions for the space station Mir, and have used this model to assess the affects of system failures and human errors that have occurred in the wake of the collision incident last year. They are developing an approach so that lessons learned from Mir operations can be systematically applied to design and operation of long-term space missions such as the International Space Station (ISS) and the manned Mars mission.

  20. Thermal modeling, analysis and control of a space suit

    NASA Astrophysics Data System (ADS)

    Campbell, Anthony Bruce

    The thermal dynamics of two space suits, the Space Shuttle EMU and the MPLSS Advanced Space Suit, are considered as they relate to astronaut thermal comfort control. The activities documented in this dissertation cover three related areas, modeling, analysis, and control. A detailed dynamic lumped capacitance thermal model of the operational Space Shuttle EMU is used to analyze the thermal dynamics of the system with observations verified using experimental and flight data. Prior to using the model to define performance characteristics and limitations for the space suit, the model is first evaluated and improved. This evaluation includes determining the effect of various model parameters on model performance and quantifying various temperature prediction errors in terms of heat transfer and heat storage. The thermal dynamics and design of an Advanced Space Suit are next considered. A transient model of the MPLSS Advanced Space Suit design is developed and implemented using MATLAB/Simulink, to help with sizing, with design evaluation, and with the development of an automatic thermal comfort control strategy. The model is described and the thermal characteristics of the Advanced Space Suit are investigated including various parametric design studies. The steady state performance envelope for the Advanced Space Suit is defined in terms of the thermal environment and human metabolic rate and the transient response of the human-suit-MPLSS system is analyzed. The observations and insights about the thermal dynamics of a space suit are then applied to the automatic thermal comfort control of the MPLSS Advanced Space Suit. Automatic thermal comfort control for the Advanced Space Suit is investigated using three proposed strategies. These strategies use a transient thermal comfort definition based on body heat storage. The first strategy is measurement based using a proposed body heat storage estimation method to determine the astronaut's thermal state. The second strategy

  1. A space crane concept: Preliminary design and static analysis

    NASA Technical Reports Server (NTRS)

    Mikulas, Martin M., Jr.; Davis, Robert C.; Greene, William H.

    1988-01-01

    Future in-space construction and assembly facilities will require the use of space cranes capable of supporting and manipulating large and massive loads. The large size of the space components being considered for construction will require that these cranes have a reach on the order of 100 meters. A space crane constructed from an erectable four-longeron truss beam with 19 5-sq-m truss bays is considered. This concept was selected to be compatible with the Space Station truss. This truss is hinged at three locations along its bottom edge and attached at one end to a rotary joint cantilevered to the assembly depot's main truss structure. The crane's boom sections are rotated by extensible longeron actuators located along the top edge of the beam. To achieve maximum position maneuvering capability for the crane requires that the individual sections be capable of rotating 180 degrees about the hinge point. This can only be accomplished by offsetting the hinges from the longeron axes. Since offset hinges introduce bending moments in the truss members, an analysis of the effect of hinge offsets on the load-carrying capacity of the structure is required. The objective of the static finite element analysis described is to determine the effect of various offset lengths on the overall bending stiffness of the crane and on the maximum stresses.

  2. Open space suitability analysis for emergency shelter after an earthquake

    NASA Astrophysics Data System (ADS)

    Anhorn, J.; Khazai, B.

    2015-04-01

    In an emergency situation shelter space is crucial for people affected by natural hazards. Emergency planners in disaster relief and mass care can greatly benefit from a sound methodology that identifies suitable shelter areas and sites where shelter services need to be improved. A methodology to rank suitability of open spaces for contingency planning and placement of shelter in the immediate aftermath of a disaster is introduced. The Open Space Suitability Index uses the combination of two different measures: a qualitative evaluation criterion for the suitability and manageability of open spaces to be used as shelter sites and another quantitative criterion using a capacitated accessibility analysis based on network analysis. For the qualitative assessment implementation issues, environmental considerations and basic utility supply are the main categories to rank candidate shelter sites. A geographic information system is used to reveal spatial patterns of shelter demand. Advantages and limitations of this method are discussed on the basis of an earthquake hazard case study in the Kathmandu Metropolitan City. According to the results, out of 410 open spaces under investigation, 12.2% have to be considered not suitable (Category D and E) while 10.7% are Category A and 17.6% are Category B. Almost two-thirds (59.55%) are fairly suitable (Category C).

  3. Open space suitability analysis for emergency shelter after an earthquake

    NASA Astrophysics Data System (ADS)

    Anhorn, J.; Khazai, B.

    2014-06-01

    In an emergency situation shelter space is crucial for people affected by natural hazards. Emergency planners in disaster relief and mass care can greatly benefit from a sound methodology that identifies suitable shelter areas and sites where shelter services need to be improved. A methodology to rank suitability of open spaces for contingency planning and placement of shelter in the immediate aftermath of a disaster is introduced. The Open Space Suitability Index (OSSI) uses the combination of two different measures: a qualitative evaluation criterion for the suitability and manageability of open spaces to be used as shelter sites, and a second quantitative criterion using a capacitated accessibility analysis based on network analysis. For the qualitative assessment, implementation issues, environmental considerations, and basic utility supply are the main categories to rank candidate shelter sites. Geographic Information System (GIS) is used to reveal spatial patterns of shelter demand. Advantages and limitations of this method are discussed on the basis of a case study in Kathmandu Metropolitan City (KMC). According to the results, out of 410 open spaces under investigation, 12.2% have to be considered not suitable (Category D and E) while 10.7% are Category A and 17.6% are Category B. Almost two third (59.5%) are fairly suitable (Category C).

  4. Macro-level pedestrian and bicycle crash analysis: Incorporating spatial spillover effects in dual state count models.

    PubMed

    Cai, Qing; Lee, Jaeyoung; Eluru, Naveen; Abdel-Aty, Mohamed

    2016-08-01

    This study attempts to explore the viability of dual-state models (i.e., zero-inflated and hurdle models) for traffic analysis zones (TAZs) based pedestrian and bicycle crash frequency analysis. Additionally, spatial spillover effects are explored in the models by employing exogenous variables from neighboring zones. The dual-state models such as zero-inflated negative binomial and hurdle negative binomial models (with and without spatial effects) are compared with the conventional single-state model (i.e., negative binomial). The model comparison for pedestrian and bicycle crashes revealed that the models that considered observed spatial effects perform better than the models that did not consider the observed spatial effects. Across the models with spatial spillover effects, the dual-state models especially zero-inflated negative binomial model offered better performance compared to single-state models. Moreover, the model results clearly highlighted the importance of various traffic, roadway, and sociodemographic characteristics of the TAZ as well as neighboring TAZs on pedestrian and bicycle crash frequency. PMID:27153525

  5. Polyethylene glycol versus dual sugar assay for gastrointestinal permeability analysis: is it time to choose?

    PubMed Central

    van Wijck, Kim; Bessems, Babs AFM; van Eijk, Hans MH; Buurman, Wim A; Dejong, Cornelis HC; Lenaerts, Kaatje

    2012-01-01

    Background Increased intestinal permeability is an important measure of disease activity and prognosis. Currently, many permeability tests are available and no consensus has been reached as to which test is most suitable. The aim of this study was to compare urinary probe excretion and accuracy of a polyethylene glycol (PEG) assay and dual sugar assay in a double-blinded crossover study to evaluate probe excretion and the accuracy of both tests. Methods Gastrointestinal permeability was measured in nine volunteers using PEG 400, PEG 1500, and PEG 3350 or lactulose-rhamnose. On 4 separate days, permeability was analyzed after oral intake of placebo or indomethacin, a drug known to increase intestinal permeability. Plasma intestinal fatty acid binding protein and calprotectin levels were determined to verify compromised intestinal integrity after indomethacin consumption. Urinary samples were collected at baseline, hourly up to 5 hours after probe intake, and between 5 and 24 hours. Urinary excretion of PEG and sugars was determined using high-pressure liquid chromatography-evaporative light scattering detection and liquid chromatography-mass spectrometry, respectively. Results Intake of indomethacin increased plasma intestinal fatty acid-binding protein and calprotectin levels, reflecting loss of intestinal integrity and inflammation. In this state of indomethacin-induced gastrointestinal compromise, urinary excretion of the three PEG probes and lactulose increased compared with placebo. Urinary PEG 400 excretion, the PEG 3350/PEG 400 ratio, and the lactulose/rhamnose ratio could accurately detect indomethacin-induced increases in gastrointestinal permeability, especially within 2 hours of probe intake. Conclusion Hourly urinary excretion and diagnostic accuracy of PEG and sugar probes show high concordance for detection of indomethacin-induced increases in gastrointestinal permeability. This comparative study improves our knowledge of permeability analysis in man

  6. Sources and Transformations of Nitrate from Streams Draining Varying Land Uses: Evidence from Dual Isotope Analysis

    NASA Astrophysics Data System (ADS)

    Burns, D. A.; Boyer, E. W.; Elliott, E. M.; Kendall, C.

    2008-12-01

    Dual isotope analysis revealed evidence of varying sources and processes that affect the transport of nitrate (NO3-) in six watersheds of different land uses in New York. Samples from two streams draining forested watersheds indicated that NO3- derived from nitrification was dominant at baseflow. Values of δ18ONO3 were greater than previously measured in forested watersheds in this region, a difference attributed to a new, more accurate sample preparation method. A watershed dominated by suburban land use, but with all waste water discharged outside the watershed had three δ18ONO3 values > 25‰ indicating a large direct contribution of atmospheric NO3- transported to the stream during some high flow periods. Two watersheds with large proportions of agricultural land use had many samples with δ15NNO3 > 9‰ suggesting a waste source consistent with direct application of manure to fields associated with dairy farming practices in the region. These data showed a linear seasonal pattern with a δ15NNO3:δ18ONO3 close to 1:2 consistent with seasonally-varying denitrification that peaked in late summer to early fall with the warmest temperatures and lowest streamflow of the year. The large annual range of δ18ONO3 (~ 10‰) in these streams suggests a large fractionation associated with denitrification, indicative of a dominance of denitrification outside of the stream environment. Mixing of two or more NO3- sources may also have affected the patterns observed in these two agricultural streams. At a larger basin scale in a mixed land use watershed that represented the average proportions of land uses in this study, none of the source and process patterns observed in the small streams were evident. These results emphasize that observations at small to medium size watersheds of a few to several hundred km2 may be necessary to adequately quantify the relative roles of various NO3- transport and process patterns that contribute to streamflow in large basins.

  7. Influence of Different Parameters on a Dual-Fractal Analysis for Antigen-Antibody Binding Kinetics for Biosensor Applications

    PubMed

    Milum; Sadana

    1997-03-01

    The diffusion-limited binding kinetics of antigen (or antibody) in solution to antibody (or antigen) immobilized on a biosensor surface is analyzed within a fractal framework. The fit obtained by a dual-fractal analysis is compared with that obtained from a single-fractal analysis. In some cases, the dual-fractal analysis provides an improved fit when compared with a single-fractal analysis. This was indicated by the regression analysis provided by Sigmaplot (46). It is of interest to note that the state of disorder (or the fractal dimension) and the binding rate coefficient both increase as the reaction progresses on the biosensor surface. For example, for the binding of HIV-1 p24 in solution to monoclonal antibody (MAb) 18 covalently attached to a biosensor surface (49), an increase in the fractal dimension by 59% from a value of Df1 equal to 1.91 to Df2 equal to 2.95 leads to an increase in the binding rate coefficient by a factor of 15 from k1 equal to 21.1 to k2 equal to 339. Also, the binding of MAb 6301 and 6303 in solution to insulin growth factor binding protein-1 (IGFBP-1) covalently attached to the sensor surface is adequately described by a single-fractal analysis (48). The binding of MAb 6302 to IGFBP-1, however, requires dual fractals. This indicates a difference in the binding mechanisms of these MAbs. The different examples analyzed and presented together provide a means by which the antigen-antibody reactions may be better controlled by noting the magnitude of the changes in the fractal dimension and in the binding rate coefficient as the reaction progresses on the biosensor surface. Also, the magnitude of the changes in the binding rate coefficients (k1 and k2) and in the fractal dimensions (Df1 and Df2) as different parameters are changed for the different biosensor applications are of particular value. PMID:9245322

  8. Analysis and design of a wideband dual-polarized antenna based on the principle of Huygens' source

    NASA Astrophysics Data System (ADS)

    Seo, Hyukjun

    Analysis and designs of wideband dual-polarized antennas for mobile wireless communication systems are presented. The concept for Huygens' sources, which are combinations of electric and magnetic dipoles, is used. As a result a wideband unidirectional antenna, which consists of a planar dipole and a slot, is selected for the antenna element. This study aims at designing a dually polarized antenna with wideband performance. The first part of the study discusses the performance of the linearly polarized antenna element at 2.5 GHz. Several design parameters associated with the antenna element are addressed. To improve the performance and increase the bandwidth, a twin-fed hook-shaped probe feeding technique is applied. Prototype antennas are fabricated and tested, and good agreement between the simulated and measured results is obtained. The second part of this study is extended to design the wideband dual-polarized patch antenna. Problems associated with the practical implementation of the dual-polarized antenna in printed form are discussed. The wideband performance of the present antenna is examined by shielding the dielectric substrate from the radiating region. The proposed antenna is fabricated and tested. In addition, a metallic side wall is adopted for suppressing the back radiation. The study for designing a possible candidate for a novel dual-polarized antenna by embedding an electromagnetic bandgap (EBG) structure is investigated. Analysis for unit-cells of mushroom-like and wideband uniplanar EBG structures is performed, and simple monopoles are used for exciting the EBG embedded antenna. The presented antennas find many possible applications in many recent wireless communication systems like 3G, 3GPP Long Term Evolution (LTE), 4G, Wi-MAX, and Wi-Bro.

  9. Effect of dual pulmonary vasodilator therapy in pulmonary arterial hypertension associated with congenital heart disease: a retrospective analysis

    PubMed Central

    Monfredi, Oliver; Heward, Elliot; Griffiths, Linda; Condliffe, Robin; Mahadevan, Vaikom S

    2016-01-01

    Background Patients with pulmonary arterial hypertension (PAH) are managed according to evidence-based treatment guidelines. Methods and results In this single-centre retrospective analysis, we examined outcomes of patients with PAH caused by congenital heart disease (PAH-CHD) with respect to exercise capacity and survival of adults treated with either bosentan or sildenafil monotherapy or bosentan-sildenafil dual therapy between January 2007 and January 2014. Of the 82 patients analysed, 29 had Down syndrome; 54 (65.8%) received bosentan monotherapy, 16 (19.5%) sildenafil monotherapy and 12 (14.6%) dual therapy. Mean treatment duration was 2.5 years for all patients and 4.1 years for 38 patients treated for ≥2 years. Pooled patient and treatment data showed initial improvement followed by stabilisation in mean 6 min walk distance (6MWD). For Down and non-Down patients, mean 6MWD increased and then stabilised on bosentan monotherapy. Mean 6MWD of patients on dual therapy at the time of analysis was 246.3 m before PAH-specific therapy initiation, 211.9 m immediately prior to addition of a second therapy and 214.4 m at last visit while on dual therapy. 1, 2 and 3-year survival rates for all patients from time of treatment initiation were 96%, 87% and 80%, respectively. Conclusions For the majority of patients, monotherapy with a PAH-specific medication provided improved and sustained exercise benefits. For the small percentage of patients who required it, add-on therapy appeared to prevent further deterioration in exercise capacity but did not improve 6MWD. PMID:27099763

  10. An analysis of clinical reasoning through a recent and comprehensive approach: the dual-process theory

    PubMed Central

    Pelaccia, Thierry; Tardif, Jacques; Triby, Emmanuel; Charlin, Bernard

    2011-01-01

    Context Clinical reasoning plays a major role in the ability of doctors to make diagnoses and decisions. It is considered as the physician's most critical competence, and has been widely studied by physicians, educationalists, psychologists and sociologists. Since the 1970s, many theories about clinical reasoning in medicine have been put forward. Purpose This paper aims at exploring a comprehensive approach: the “dual-process theory”, a model developed by cognitive psychologists over the last few years. Discussion After 40 years of sometimes contradictory studies on clinical reasoning, the dual-process theory gives us many answers on how doctors think while making diagnoses and decisions. It highlights the importance of physicians’ intuition and the high level of interaction between analytical and non-analytical processes. However, it has not received much attention in the medical education literature. The implications of dual-process models of reasoning in terms of medical education will be discussed. PMID:21430797

  11. Recent advances in electromagnetic synthesis and analysis of dual-shaped reflector antennas

    NASA Technical Reports Server (NTRS)

    Galindo-Israel, V.; Rahmat-Samii, Y.; Imbriale, W.; Mittra, R.

    1982-01-01

    Dual-shaped reflectors have been used for many years. Thus, these reflectors have been used as high gain antennas on Voyagers 1 and 2. The objectives of the geometrical optics (GO) dual shaped synthesis are considered. Concerning the synthesis of dual shaped reflectors, it has been shown for circular symmetric reflectors that an exact GO solution can be found to the problem of transforming, by two reflections, any feed pattern into any aperture distribution. This problem involves solving two simultaneous nonlinear ordinary differential equations. The same approach for offset geometry leads to two simultaneous nonlinear partial differential equations. It is shown that these equations could also be integrated numerically, except that in general these equations are not total and therefore, in general, they do not have a 'smooth' solution. It is further shown that the offset partial differentials often very nearly form a total differential in many cases of practical importance.

  12. Algebraic dual-energy magnetic analysis with application to variable reluctance motor design

    SciTech Connect

    Tolikas, M.; Lang, J.H.; Kirtley, J.L. Jr.

    1995-12-31

    The dual-energy method has been successfully employed in the calculation of static resistances, capacitances and inductances, yielding fast and accurate solutions. Two different directions can be followed in applying the method, one is the more widely known method of tubes and slices, the other is the algebraic approach and is explored further in this paper. The present literature on the algebraic dual-energy method involves trivial examples with boundaries, boundary conditions and source distributions that are easily handled. However, the geometry of the variable reluctance motor at the unaligned position, the dominating curvatures characterizing its electromagnetic field distribution and the presence of a large number of boundary conditions arising at the steel boundaries, provide a challenging exercise in the application, behavior and effectiveness of the dual-energy method in a realistic framework.

  13. State Space Modelling and Data Analysis Exercises in LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Nofrarias, M.; Antonucci, F.; Armano, M.; Audley, H.; Auger, G.; Benedetti, M.; Binetruy, P.; Bogenstahl, J.; Bortoluzzi, D.; Brandt, N.; Caleno, M.; Cavalleri, A.; Congedo, G.; Cruise, M.; Danzmann, K.; De Marchi, F.; Diaz-Aguilo, M.; Diepholz, I.; Dixon, G.; Dolesi, R.; Dunbar, N.; Fauste, J.; Ferraioli, L.; Ferroni, V.; Fichter, W.; Fitzsimons, E.; Freschi, M.; García Marirrodriga, C.; Gerndt, R.; Gesa, L.; Gibert, F.; Giardini, D.; Grimani, C.; Grynagier, A.; Guzmán, F.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hoyland, D.; Hueller, M.; Huesler, J.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Korsakova, N.; Killow, C.; Llamas, X.; Lloro, I.; Lobo, A.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Martin, V.; Mateos, I.; McNamara, P.; Mendes, J.; Mitchell, E.; Nicolodi, D.; Perreur-Lloyd, M.; Plagnol, E.; Prat, P.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Russano, G.; Schleicher, A.; Shaul, D.; Sopuerta, C. F.; Sumner, T. J.; Taylor, A.; Texier, D.; Trenkel, C.; Tu, H. B.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Wealthy, D.; Wen, S.; Weber, W.; Ziegler, T.; Zweifel, P.

    2013-01-01

    LISA Pathfinder is a mission planned by the European Space Agency (ESA) to test the key technologies that will allow the detection of gravitational waves in space. The instrument on-board, the LISA Technology package, will undergo an exhaustive campaign of calibrations and noise characterisation campaigns in order to fully describe the noise model. Data analysis plays an important role in the mission and for that reason the data analysis team has been developing a toolbox which contains all the functionality required during operations. In this contribution we give an overview of recent activities, focusing on the improvements in the modelling of the instrument and in the data analysis campaigns performed both with real and simulated data.

  14. Repair-level analysis for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Chadwick, M.; Yaniec, J.

    1992-01-01

    To assign repair or discard-at-failure designations for orbital replacement units (ORUs) used on Space Station Freedom Electric Power System (SSFEPS), new algorithms and methods were required. Unique parameters, such as upmass costs, extravehicular activity costs and intravehicular activity (IVA) costs specific to Space Station Freedom's maintenance concept were incorporated into the Repair-Level Analysis (RLA). Additional outputs were also required of the SSFEPS RLA that were not required of previous RLAs. These outputs included recommendations for the number of launches that an ORU should be capable of attaining and an economic basis for condemnation rate. These unique parameters were not addressable using existing RLA models: therefore, a new approach was developed. In addition, it was found that preemptive analysis could be performed using spreadsheet-based Boolean expressions to represent the logical condition of the items under analysis.

  15. Analysis on singular spaces: Lie manifolds and operator algebras

    NASA Astrophysics Data System (ADS)

    Nistor, Victor

    2016-07-01

    We discuss and develop some connections between analysis on singular spaces and operator algebras, as presented in my sequence of four lectures at the conference Noncommutative geometry and applications, Frascati, Italy, June 16-21, 2014. Therefore this paper is mostly a survey paper, but the presentation is new, and there are included some new results as well. In particular, Sections 3 and 4 provide a complete short introduction to analysis on noncompact manifolds that is geared towards a class of manifolds-called "Lie manifolds" -that often appears in practice. Our interest in Lie manifolds is due to the fact that they provide the link between analysis on singular spaces and operator algebras. The groupoids integrating Lie manifolds play an important background role in establishing this link because they provide operator algebras whose structure is often well understood. The initial motivation for the work surveyed here-work that spans over close to two decades-was to develop the index theory of stratified singular spaces. Meanwhile, several other applications have emerged as well, including applications to Partial Differential Equations and Numerical Methods. These will be mentioned only briefly, however, due to the lack of space. Instead, we shall concentrate on the applications to Index theory.

  16. Magnetic Testing, and Modeling, Simulation and Analysis for Space Applications

    NASA Technical Reports Server (NTRS)

    Boghosian, Mary; Narvaez, Pablo; Herman, Ray

    2012-01-01

    The Aerospace Corporation (Aerospace) and Lockheed Martin Space Systems (LMSS) participated with Jet Propulsion Laboratory (JPL) in the implementation of a magnetic cleanliness program of the NASA/JPL JUNO mission. The magnetic cleanliness program was applied from early flight system development up through system level environmental testing. The JUNO magnetic cleanliness program required setting-up a specialized magnetic test facility at Lockheed Martin Space Systems for testing the flight system and a testing program with facility for testing system parts and subsystems at JPL. The magnetic modeling, simulation and analysis capability was set up and performed by Aerospace to provide qualitative and quantitative magnetic assessments of the magnetic parts, components, and subsystems prior to or in lieu of magnetic tests. Because of the sensitive nature of the fields and particles scientific measurements being conducted by the JUNO space mission to Jupiter, the imposition of stringent magnetic control specifications required a magnetic control program to ensure that the spacecraft's science magnetometers and plasma wave search coil were not magnetically contaminated by flight system magnetic interferences. With Aerospace's magnetic modeling, simulation and analysis and JPL's system modeling and testing approach, and LMSS's test support, the project achieved a cost effective approach to achieving a magnetically clean spacecraft. This paper presents lessons learned from the JUNO magnetic testing approach and Aerospace's modeling, simulation and analysis activities used to solve problems such as remnant magnetization, performance of hard and soft magnetic materials within the targeted space system in applied external magnetic fields.

  17. Statistical analysis of flight times for space shuttle ferry flights

    NASA Technical Reports Server (NTRS)

    Graves, M. E.; Perlmutter, M.

    1974-01-01

    Markov chain and Monte Carlo analysis techniques are applied to the simulated Space Shuttle Orbiter Ferry flights to obtain statistical distributions of flight time duration between Edwards Air Force Base and Kennedy Space Center. The two methods are compared, and are found to be in excellent agreement. The flights are subjected to certain operational and meteorological requirements, or constraints, which cause eastbound and westbound trips to yield different results. Persistence of events theory is applied to the occurrence of inclement conditions to find their effect upon the statistical flight time distribution. In a sensitivity test, some of the constraints are varied to observe the corresponding changes in the results.

  18. OASIS Observation and Analysis of Smectic Islands in Space

    NASA Technical Reports Server (NTRS)

    Tin, Padetha

    2014-01-01

    The Observation and Analysis of Smectic Islands in Space (OASIS) project comprises a series of experiments that will probe the interfacial and hydrodynamic behavior of freely suspended liquid crystal films in space. These are the thinnest known stable condensed phase structures, making them ideal for studies of fluctuation and interface phenomena. The experiments seek to verify theories of coarsening dynamics, hydrodynamic flow, relaxation of hydrodynamic perturbations, and hydrodynamic interactions of a near two-dimensional structure. The effects of introducing islands or droplets on a very thin bubble will be studied, both as controllable inclusions that modify the flow and as markers of flow.

  19. Hubble Space Telescope maintenance and refurbishment planning analysis

    NASA Technical Reports Server (NTRS)

    Pizzano, F.; Kincade, R. S.

    1989-01-01

    This paper presents an updated analytical approach toward the identification of Hubble Space Telescope system failures and downstates, maintenance requirements, and overall support to maintenance mission planning. Different sparing options of Orbital Replacement Units are evaluated, and the optimum spares complement that satisfies the expected servicing requirements is identified. Specific Space Telescope Reliability and maintenance Simulation Computer Program (SPATEL) updates and refinements are reported, and input data updates relevant to failure rates, downstate ground rules, and maintenance policy are addressed. A summary of the latest SPATEL outputs is provided along with maintenance analysis results.

  20. Heat Transfer Analysis of a Closed Brayton Cycle Space Radiator

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.

    2007-01-01

    This paper presents a mathematical analysis of the heat transfer processes taking place in a radiator for a closed cycle gas turbine (CCGT), also referred to as a Closed Brayton Cycle (CBC) space power system. The resulting equations and relationships have been incorporated into a radiator sub-routine of a numerical triple objective CCGT optimization program to determine operating conditions yielding maximum cycle efficiency, minimum radiator area and minimum overall systems mass. Study results should be of interest to numerical modeling of closed cycle Brayton space power systems and to the design of fluid cooled radiators in general.

  1. Experimental verification of long-term evolution radio transmissions over dual-polarization combined fiber and free-space optics optical infrastructures.

    PubMed

    Bohata, J; Zvanovec, S; Pesek, P; Korinek, T; Mansour Abadi, M; Ghassemlooy, Z

    2016-03-10

    This paper describes the experimental verification of the utilization of long-term evolution radio over fiber (RoF) and radio over free space optics (RoFSO) systems using dual-polarization signals for cloud radio access network applications determining the specific utilization limits. A number of free space optics configurations are proposed and investigated under different atmospheric turbulence regimes in order to recommend the best setup configuration. We show that the performance of the proposed link, based on the combination of RoF and RoFSO for 64 QAM at 2.6 GHz, is more affected by the turbulence based on the measured difference error vector magnitude value of 5.5%. It is further demonstrated the proposed systems can offer higher noise immunity under particular scenarios with the signal-to-noise ratio reliability limit of 5 dB in the radio frequency domain for RoF and 19.3 dB in the optical domain for a combination of RoF and RoFSO links. PMID:26974810

  2. Design and assembly sequence analysis of option 3 for CETF reference space station

    NASA Technical Reports Server (NTRS)

    Garrett, L. Bernard; Andersen, Gregory C.; Hall, John B., Jr.; Allen, Cheryl L.; Scott, A. D., Jr.; So, Kenneth T.

    1987-01-01

    A design and assembly sequence was conducted on one option of the Dual Keel Space Station examined by a NASA Critical Evaluation Task Force to establish viability of several variations of that option. A goal of the study was to produce and analyze technical data to support Task Force decisions to either examine particular Option 3 variations in more depth or eliminate them from further consideration. An analysis of the phasing assembly showed that use of an Expendable Launch Vehicle in conjunction with the Space Transportation System (STS) can accelerate the buildup of the Station and ease the STS launch rate constraints. The study also showed that use of an Orbital Maneuvering Vehicle on the first flight can significantly benefit Station assembly and, by performing Station subsystem functions, can alleviate the need for operational control and reboost systems during the early flights. In addition to launch and assembly sequencing, the study assessed stability and control, and analyzed node-packaging options and the effects of keel removal on the structural dynamics of the Station. Results of these analyses are presented and discussed.

  3. Advanced development in phytochemicals analysis of medicine and food dual purposes plants used in China (2011-2014).

    PubMed

    Zhao, Jing; Ge, Li-Ya; Xiong, Wei; Leong, Fong; Huang, Lu-Qi; Li, Shao-Ping

    2016-01-01

    In 2011, we wrote a review for summarizing the phytochemical analysis (2006-2010) of medicine and food dual purposes plants used in China (Zhao et al., J. Chromatogr. A 1218 (2011) 7453-7475). Since then, more than 750 articles related to their phytochemical analysis have been published. Therefore, an updated review for the advanced development (2011-2014) in this topic is necessary for well understanding the quality control and health beneficial phytochemicals in these materials, as well as their research trends. PMID:26385085

  4. Nuclear reactor descriptions for space power systems analysis

    NASA Technical Reports Server (NTRS)

    Mccauley, E. W.; Brown, N. J.

    1972-01-01

    For the small, high performance reactors required for space electric applications, adequate neutronic analysis is of crucial importance, but in terms of computational time consumed, nuclear calculations probably yield the least amount of detail for mission analysis study. It has been found possible, after generation of only a few designs of a reactor family in elaborate thermomechanical and nuclear detail to use simple curve fitting techniques to assure desired neutronic performance while still performing the thermomechanical analysis in explicit detail. The resulting speed-up in computation time permits a broad detailed examination of constraints by the mission analyst.

  5. Methods of space radiation dose analysis with applications to manned space systems

    NASA Technical Reports Server (NTRS)

    Langley, R. W.; Billings, M. P.

    1972-01-01

    The full potential of state-of-the-art space radiation dose analysis for manned missions has not been exploited. Point doses have been overemphasized, and the critical dose to the bone marrow has been only crudely approximated, despite the existence of detailed man models and computer codes for dose integration in complex geometries. The method presented makes it practical to account for the geometrical detail of the astronaut as well as the vehicle. Discussed are the major assumptions involved and the concept of applying the results of detailed proton dose analysis to the real-time interpretation of on-board dosimetric measurements.

  6. Aerosol Profile Retrievals from Integrated Dual Wavelengths Space Lidar ESSP3-CENA and Spectral Radiance MODIS Data

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram; Mattoo, Shana; Tanre, Didier; Kleidman, Richard; Lau, William K. M. (Technical Monitor)

    2001-01-01

    The ESSP3-CENA space mission (formally PICASSO-CENA) will provide continues global observations with a two wavelength lidar. The attenuated backscattering coefficients measured by the lidar, have valuable information about the vertical distribution of aerosol particles and their sizes. However the information cannot be mapped into unique aerosol physical properties. Infinite number of physical solutions with different attenuations through the atmosphere can reconstruct the same two wavelength backscattered profile measured from space. Spectral radiance measured by MODIS simultaneously with the ESSP3 data can constrain the problem and resolve this ambiguity to a large extent. Sensitivity study shows that inversion of the integrated MODIS+ESSP3 data can derive the vertical profiles of the fine and coarse modes mixed in the same atmospheric column in the presence of moderate calibration uncertainties and electronic noise (approx. 10%). We shall present the sensitivity study and results from application of the technique to measurements in the SAFARI-2000 and SHADE experiments.

  7. Cascaded systems analysis of noise reduction algorithms in dual-energy imaging

    SciTech Connect

    Richard, Samuel; Siewerdsen, Jeffrey H.

    2008-02-15

    An important aspect of dual-energy (DE) x-ray image decomposition is the incorporation of noise reduction techniques to mitigate the amplification of quantum noise. This article extends cascaded systems analysis of imaging performance to DE imaging systems incorporating linear noise reduction algorithms. A general analytical formulation of linear DE decomposition is derived, with weighted log subtraction and several previously reported noise reduction algorithms emerging as special cases. The DE image noise-power spectrum (NPS) and modulation transfer function (MTF) demonstrate that noise reduction algorithms impart significant, nontrivial effects on the spatial-frequency-dependent transfer characteristics which do not cancel out of the noise-equivalent quanta (NEQ). Theoretical predictions were validated in comparison to the measured NPS and MTF. The resulting NEQ was integrated with spatial-frequency-dependent task functions to yield the detectability index, d{sup '}, for evaluation of DE imaging performance using different decomposition algorithms. For a 3 mm lung nodule detection task, the detectability index varied from d{sup '}<1 (i.e., nodule barely visible) in the absence of noise reduction to d{sup '}>2.5 (i.e., nodule clearly visible) for ''anti-correlated noise reduction'' (ACNR) or ''simple-smoothing of the high-energy image'' (SSH) algorithms applied to soft-tissue or bone-only decompositions, respectively. Optimal dose allocation (A{sup *}, the fraction of total dose delivered in the low-energy projection) was also found to depend on the choice of noise reduction technique. At fixed total dose, multi-function optimization suggested a significant increase in optimal dose allocation from A{sup *}=0.32 for conventional log subtraction to A{sup *}=0.79 for ACNR and SSH in soft-tissue and bone-only decompositions, respectively. Cascaded systems analysis extended to the general formulation of DE image decomposition provided an objective means of

  8. Slight pressure imbalances can affect accuracy and precision of dual inlet-based clumped isotope analysis.

    PubMed

    Fiebig, Jens; Hofmann, Sven; Löffler, Niklas; Lüdecke, Tina; Methner, Katharina; Wacker, Ulrike

    2016-01-01

    It is well known that a subtle nonlinearity can occur during clumped isotope analysis of CO2 that - if remaining unaddressed - limits accuracy. The nonlinearity is induced by a negative background on the m/z 47 ion Faraday cup, whose magnitude is correlated with the intensity of the m/z 44 ion beam. The origin of the negative background remains unclear, but is possibly due to secondary electrons. Usually, CO2 gases of distinct bulk isotopic compositions are equilibrated at 1000 °C and measured along with the samples in order to be able to correct for this effect. Alternatively, measured m/z 47 beam intensities can be corrected for the contribution of secondary electrons after monitoring how the negative background on m/z 47 evolves with the intensity of the m/z 44 ion beam. The latter correction procedure seems to work well if the m/z 44 cup exhibits a wider slit width than the m/z 47 cup. Here we show that the negative m/z 47 background affects precision of dual inlet-based clumped isotope measurements of CO2 unless raw m/z 47 intensities are directly corrected for the contribution of secondary electrons. Moreover, inaccurate results can be obtained even if the heated gas approach is used to correct for the observed nonlinearity. The impact of the negative background on accuracy and precision arises from small imbalances in m/z 44 ion beam intensities between reference and sample CO2 measurements. It becomes the more significant the larger the relative contribution of secondary electrons to the m/z 47 signal is and the higher the flux rate of CO2 into the ion source is set. These problems can be overcome by correcting the measured m/z 47 ion beam intensities of sample and reference gas for the contributions deriving from secondary electrons after scaling these contributions to the intensities of the corresponding m/z 49 ion beams. Accuracy and precision of this correction are demonstrated by clumped isotope analysis of three internal carbonate standards. The

  9. Failure Analysis in Space: International Space Station (ISS) Starboard Solar Alpha Rotary Joint (SARJ) Debris Analysis

    NASA Technical Reports Server (NTRS)

    Long, V. S.; Wright, M. C.; McDanels, S. J.; Lubas, D.; Tucker, B.; Marciniak, P. J.

    2010-01-01

    This slide presentation reviews the debris analysis of the Starboard Solar Alpha Rotary Joint (SARJ), a mechanism that is designed to keep the solar arrays facing the sun. The goal of this was to identify the failure mechanism based on surface morphology and to determine the source of debris through elemental and particle analysis.

  10. Automated shock detection and analysis algorithm for space weather application

    NASA Astrophysics Data System (ADS)

    Vorotnikov, Vasiliy S.; Smith, Charles W.; Hu, Qiang; Szabo, Adam; Skoug, Ruth M.; Cohen, Christina M. S.

    2008-03-01

    Space weather applications have grown steadily as real-time data have become increasingly available. Numerous industrial applications have arisen with safeguarding of the power distribution grids being a particular interest. NASA uses short-term and long-term space weather predictions in its launch facilities. Researchers studying ionospheric, auroral, and magnetospheric disturbances use real-time space weather services to determine launch times. Commercial airlines, communication companies, and the military use space weather measurements to manage their resources and activities. As the effects of solar transients upon the Earth's environment and society grow with the increasing complexity of technology, better tools are needed to monitor and evaluate the characteristics of the incoming disturbances. A need is for automated shock detection and analysis methods that are applicable to in situ measurements upstream of the Earth. Such tools can provide advance warning of approaching disturbances that have significant space weather impacts. Knowledge of the shock strength and speed can also provide insight into the nature of the approaching solar transient prior to arrival at the magnetopause. We report on efforts to develop a tool that can find and analyze shocks in interplanetary plasma data without operator intervention. This method will run with sufficient speed to be a practical space weather tool providing useful shock information within 1 min of having the necessary data to ground. The ability to run without human intervention frees space weather operators to perform other vital services. We describe ways of handling upstream data that minimize the frequency of false positive alerts while providing the most complete description of approaching disturbances that is reasonably possible.

  11. Results and Analysis from Space Suit Joint Torque Testing

    NASA Technical Reports Server (NTRS)

    Matty, Jennifer E.; Aitchison, Lindsay

    2009-01-01

    A space suit s mobility is critical to an astronaut s ability to perform work efficiently. As mobility increases, the astronaut can perform tasks for longer durations with less fatigue. The term mobility, with respect to space suits, is defined in terms of two key components: joint range of motion and joint torque. Individually these measures describe the path which in which a joint travels and the force required to move it through that path. Previous space suits mobility requirements were defined as the collective result of these two measures and verified by the completion of discrete functional tasks. While a valid way to impose mobility requirements, such a method does necessitate a solid understanding of the operational scenarios in which the final suit will be performing. Because the Constellation space suit system requirements are being finalized with a relatively immature concept of operations, the Space Suit Element team elected to define mobility in terms of its constituent parts to increase the likelihood that the future pressure garment will be mobile enough to enable a broad scope of undefined exploration activities. The range of motion requirements were defined by measuring the ranges of motion test subjects achieved while performing a series of joint maximizing tasks in a variety of flight and prototype space suits. The definition of joint torque requirements has proved more elusive. NASA evaluated several different approaches to the problem before deciding to generate requirements based on unmanned joint torque evaluations of six different space suit configurations being articulated through 16 separate joint movements. This paper discusses the experiment design, data analysis and results, and the process used to determine the final values for the Constellation pressure garment joint torque requirements.

  12. Cyber threat impact assessment and analysis for space vehicle architectures

    NASA Astrophysics Data System (ADS)

    McGraw, Robert M.; Fowler, Mark J.; Umphress, David; MacDonald, Richard A.

    2014-06-01

    This paper covers research into an assessment of potential impacts and techniques to detect and mitigate cyber attacks that affect the networks and control systems of space vehicles. Such systems, if subverted by malicious insiders, external hackers and/or supply chain threats, can be controlled in a manner to cause physical damage to the space platforms. Similar attacks on Earth-borne cyber physical systems include the Shamoon, Duqu, Flame and Stuxnet exploits. These have been used to bring down foreign power generation and refining systems. This paper discusses the potential impacts of similar cyber attacks on space-based platforms through the use of simulation models, including custom models developed in Python using SimPy and commercial SATCOM analysis tools, as an example STK/SOLIS. The paper discusses the architecture and fidelity of the simulation model that has been developed for performing the impact assessment. The paper walks through the application of an attack vector at the subsystem level and how it affects the control and orientation of the space vehicle. SimPy is used to model and extract raw impact data at the bus level, while STK/SOLIS is used to extract raw impact data at the subsystem level and to visually display the effect on the physical plant of the space vehicle.

  13. Chemical analysis and ozone formation potential of exhaust from dual-fuel (liquefied petroleum gas/gasoline) light duty vehicles

    NASA Astrophysics Data System (ADS)

    Adam, T. W.; Astorga, C.; Clairotte, M.; Duane, M.; Elsasser, M.; Krasenbrink, A.; Larsen, B. R.; Manfredi, U.; Martini, G.; Montero, L.; Sklorz, M.; Zimmermann, R.; Perujo, A.

    2011-06-01

    Measures must be undertaken to lower the transport sector's contribution to anthropogenic emissions. Vehicles powered by liquefied petroleum gas (LPG) are an option due to their reduced emissions of air pollutants compared to engines with conventional fuels. In the present study, ten different dual-fuel LPG/gasoline light duty vehicles were tested, which all complied with European emission level legislation EURO-4. Tests with LPG and gasoline were performed on a chassis dynamometer by applying the New European Driving Cycle (NEDC) and emission factors and ozone formation potentials of both kinds of fuels were compared. The components investigated comprised regulated compounds, CO 2, volatile hydrocarbons and carbonyls. On-line analysis of aromatic species was carried out by resonance-enhanced multiphoton ionization-time-of-flight mass spectrometry (REMPI-TOFMS). We demonstrate that utilization of LPG can entail some environmental benefits by reducing emissions. However, for dual-fuel LPG/gasoline vehicles running on LPG the benefits are less than expected. The main reason is that dual-fuel vehicles usually start the engine up on gasoline even when LPG is selected as fuel. This cold-start phase is crucial for the quality of the emissions. Moreover, we demonstrate an influence on the chemical composition of emissions of vehicle performance, fuel and the evaporative emission system of the vehicles.

  14. Hot-electron real-space transfer and longitudinal transport in dual AlGaN/AlN/{AlGaN/GaN} channels

    NASA Astrophysics Data System (ADS)

    Šermukšnis, E.; Liberis, J.; Matulionis, A.; Avrutin, V.; Ferreyra, R.; Özgür, Ü.; Morkoç, H.

    2015-03-01

    Real-space transfer of hot electrons is studied in dual-channel GaN-based heterostructure operated at or near plasmon-optical phonon resonance in order to attain a high electron drift velocity at high current densities. For this study, pulsed electric field is applied in the channel plane of a nominally undoped Al0.3Ga0.7N/AlN/{Al0.15Ga0.85N/GaN} structure with a composite channel of Al0.15Ga0.85N/GaN, where the electrons with a sheet density of 1.4 × 1013 cm-2, estimated from the Hall effect measurements, are confined. The equilibrium electrons are situated predominantly in the Al0.15Ga0.85N layer as confirmed by capacitance-voltage experiment and Schrödinger-Poisson modelling. The main peak of the electron density per unit volume decreases as more electrons occupy the GaN layer at high electric fields. The associated decrease in the plasma frequency induces the plasmon-assisted decay of non-equilibrium optical phonons (hot phonons) confirmed by the decrease in the measured hot-phonon lifetime from 0.95 ps at low electric fields down below 200 fs at fields of E \\gt 4 kV cm-1 as the plasmon-optical phonon resonance is approached. The onset of real-space transfer is resolved from microwave noise measurements: this source of noise dominates for E \\gt 8 kV cm-1. In this range of fields, the longitudinal current exceeds the values measured for a mono channel reference Al0.3Ga0.7N/AlN/GaN structure. The results are explained in terms of the ultrafast decay of hot phonons and reduced alloy scattering caused by the real-space transfer in the composite channel.

  15. Analysis and design of DSP-based dual-loop controlled UPS inverters.

    PubMed

    Wu, Xie-Hua; Yan, Chao

    2003-01-01

    This paper presents a novel digital dual-loop control scheme of the PWM (Pulse width modulate) inverter. Deadbeat control technique are employed to enhance the performance. Half switching period delayed sampling and control tining strategy is used to improve the system dynamic response. Simulation and experimental results presented in the paper verified the validity of the proposed control scheme. PMID:12765279

  16. An analysis of the effects of secondary reflections on dual-frequency reflectometers

    NASA Technical Reports Server (NTRS)

    Hearn, C. P.; Cockrell, C. R.; Harrah, S. D.

    1990-01-01

    The error-producing mechanism involving secondary reflections in a dual-frequency, distance measuring reflectometer is examined analytically. Equations defining the phase, and hence distance, error are derived. The error-reducing potential of frequency-sweeping is demonstrated. It is shown that a single spurious return can be completely nullified by optimizing the sweep width.

  17. A Template Analysis of Teacher Agency at an Academically Successful Dual Language School

    ERIC Educational Resources Information Center

    Ray, Juliet M.

    2009-01-01

    Evidence suggests that dual language (DL) programs have the potential to foster both significant academic achievement and increased cultural awareness in the students they serve. As such, DL programs offer both language majority and language minority learners the opportunity to reach advanced levels of academic achievement. Nonetheless, the…

  18. Social Work Education in Dual Relationships: An Analysis of Undergraduate Knowledge of Ethical Relationships

    ERIC Educational Resources Information Center

    Carney, Jeremy William

    2010-01-01

    This study examined ethics education as it relates to non-sexual dual relationships in accredited bachelor of social work programs in the state of Minnesota. The results of the study indicated that the majority of undergraduate social work students in Minnesota reported receiving instruction in ethical issues surrounding non-sexual dual…

  19. Analysis of dual-task elderly gait using wearable plantar-pressure insoles and accelerometer.

    PubMed

    Howcroft, Jennifer D; Lemaire, Edward D; Kofman, Jonathan; McIlroy, William E

    2014-01-01

    Dual-task gait allows assessment of impaired executive function and mobility control in older individuals, which are risk factors of falls. This study investigated gait changes in older individuals due to the addition of a cognitive load, using wearable pressure-sensing insole and tri-axial accelerometer measures. These wearable sensors can be applied at the point-of-care. Eleven elderly (65 years or older) individuals walked 7.62 m with and without a verbal fluency cognitive load task while wearing FScan 3000E pressure-sensing insoles in both shoes and a Gulf Coast X16-1C tri-axial accelerometer at the pelvis. Plantar-pressure derived parameters included center of force (CoF) path and temporal measures. Acceleration derived measures were descriptive statistics, Fast Fourier Transform quartile, ratio of even-to-odd harmonics, and maximum Lyapunov exponent. Stride time, stance time, and swing time all significantly increased during dual-task compared to single-task walking. Minimum, mean, and median CoF stance velocity; cadence; and vertical, anterior-posterior, and medial-lateral harmonic ratio all significantly decreased during dual-task walking. Wearable plantar pressure-sensing insole and lower back accelerometer derived-measures can identify gait differences between single-task and dual-task walking in older individuals and could be used in point-of-care environments to assess for deficits in executive function and mobility impairments. PMID:25571116

  20. Graduation, Reality, and Dual-Role Skills (GRADS). Occupational Competency Analysis Profile.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Vocational Instructional Materials Lab.

    GRADS (Graduation, Reality, and Dual-Role Skills) is an in-school instructional and intervention program for pregnant teens and young parents. Its objectives are to help these students remain in school through graduation, have healthy pregnancies and healthy babies, learn practical parenting and child-development skills, gain an orientation to…

  1. Dual Enrollment Course Content and Instructor Quality. ECS Education Policy Analysis

    ERIC Educational Resources Information Center

    Dounay Zinth, Jennifer

    2015-01-01

    Knowing that the majority of dual enrollment courses are taught on high school campuses by high school instructors, it is critical that mechanisms are in place to ensure the quality of the curriculum and the many components surrounding the curriculum--including textbooks, learning outcomes, course syllabuses, assignments, grading practices,…

  2. Space Human Factors Engineering Gap Analysis Project Final Report

    NASA Technical Reports Server (NTRS)

    Hudy, Cynthia; Woolford, Barbara

    2006-01-01

    Humans perform critical functions throughout each phase of every space mission, beginning with the mission concept and continuing to post-mission analysis (Life Sciences Division, 1996). Space missions present humans with many challenges - the microgravity environment, relative isolation, and inherent dangers of the mission all present unique issues. As mission duration and distance from Earth increases, in-flight crew autonomy will increase along with increased complexity. As efforts for exploring the moon and Mars advance, there is a need for space human factors research and technology development to play a significant role in both on-orbit human-system interaction, as well as the development of mission requirements and needs before and after the mission. As part of the Space Human Factors Engineering (SHFE) Project within the Human Research Program (HRP), a six-month Gap Analysis Project (GAP) was funded to identify any human factors research gaps or knowledge needs. The overall aim of the project was to review the current state of human factors topic areas and requirements to determine what data, processes, or tools are needed to aid in the planning and development of future exploration missions, and also to prioritize proposals for future research and technology development.

  3. Micro-Logistics Analysis for Human Space Exploration

    NASA Technical Reports Server (NTRS)

    Cirillo, William; Stromgren, Chel; Galan, Ricardo

    2008-01-01

    Traditionally, logistics analysis for space missions has focused on the delivery of elements and goods to a destination. This type of logistics analysis can be referred to as "macro-logistics". While the delivery of goods is a critical component of mission analysis, it captures only a portion of the constraints that logistics planning may impose on a mission scenario. The other component of logistics analysis concerns the local handling of goods at the destination, including storage, usage, and disposal. This type of logistics analysis, referred to as "micro-logistics", may also be a primary driver in the viability of a human lunar exploration scenario. With the rigorous constraints that will be placed upon a human lunar outpost, it is necessary to accurately evaluate micro-logistics operations in order to develop exploration scenarios that will result in an acceptable level of system performance.

  4. Applying AI tools to operational space environmental analysis

    NASA Technical Reports Server (NTRS)

    Krajnak, Mike; Jesse, Lisa; Mucks, John

    1995-01-01

    The U.S. Air Force and National Oceanic Atmospheric Agency (NOAA) space environmental operations centers are facing increasingly complex challenges meeting the needs of their growing user community. These centers provide current space environmental information and short term forecasts of geomagnetic activity. Recent advances in modeling and data access have provided sophisticated tools for making accurate and timely forecasts, but have introduced new problems associated with handling and analyzing large quantities of complex data. AI (Artificial Intelligence) techniques have been considered as potential solutions to some of these problems. Fielding AI systems has proven more difficult than expected, in part because of operational constraints. Using systems which have been demonstrated successfully in the operational environment will provide a basis for a useful data fusion and analysis capability. Our approach uses a general purpose AI system already in operational use within the military intelligence community, called the Temporal Analysis System (TAS). TAS is an operational suite of tools supporting data processing, data visualization, historical analysis, situation assessment and predictive analysis. TAS includes expert system tools to analyze incoming events for indications of particular situations and predicts future activity. The expert system operates on a knowledge base of temporal patterns encoded using a knowledge representation called Temporal Transition Models (TTM's) and an event database maintained by the other TAS tools. The system also includes a robust knowledge acquisition and maintenance tool for creating TTM's using a graphical specification language. The ability to manipulate TTM's in a graphical format gives non-computer specialists an intuitive way of accessing and editing the knowledge base. To support space environmental analyses, we used TAS's ability to define domain specific event analysis abstractions. The prototype system defines

  5. Perspectives about Family Meals from Single-Headed and Dual-Headed Households: A Qualitative Analysis

    PubMed Central

    Berge, Jerica M.; Hoppmann, Caroline; Hanson, Carrie; Neumark-Sztainer, Dianne

    2013-01-01

    Cross-sectional and longitudinal research has shown that family meals are protective for adolescent healthful eating behaviors. However, little is known about what parents think of these findings and whether parents from single- versus dual-headed households have differing perspectives about the findings. Additionally, parents’ perspectives regarding barriers to applying the findings on family meals in their own homes and suggestions for more wide-spread adoption of the findings are unknown. The current study aimed to identify single- and dual-headed household parents’ perspectives regarding the research findings on family meals, barriers to applying the findings in their own homes and suggestions for helping families have more family meals. The current qualitative study included 59 parents who participated in sub-study of two linked multi-level studies—EAT 2010 (Eating and Activity in Teens) and Families and Eating and Activity in Teens (F-EAT). Parents (91.5% female) were racially/ethnically and socio-economically diverse. Data were analyzed using a grounded theory approach. Results from the current study suggest that parents from both single- and dual-headed households have similar perspectives regarding why family meals are protective for healthful eating habits for adolescents (e.g., provides structure/routine, opportunities for communication, connection), but provide similar and different reasons for barriers to family meals (e.g., single-headed=cost vs. dual-headed=lack of creativity) and ideas and suggestions for how to increase the frequency of family meals (e.g., single-headed=give fewer options vs. dual-headed=include children in the meal preparation). Findings may help inform public health intervention researchers and providers who work with adolescents and their families to understand how to approach discussions regarding reasons for having family meals, barriers to carrying out family meals and ways to increase family meals depending on family

  6. Perspectives about family meals from single-headed and dual-headed households: a qualitative analysis.

    PubMed

    Berge, Jerica M; Hoppmann, Caroline; Hanson, Carrie; Neumark-Sztainer, Dianne

    2013-12-01

    Cross-sectional and longitudinal research has shown that family meals are protective for adolescent healthful eating behaviors. However, little is known about what parents think of these findings and whether parents from single- vs dual-headed households have differing perspectives about the findings. In addition, parents' perspectives regarding barriers to applying the findings on family meals in their own homes and suggestions for more widespread adoption of the findings are unknown. The current study aimed to identify single- and dual-headed household parents' perspectives regarding the research findings on family meals, barriers to applying the findings in their own homes, and suggestions for helping families have more family meals. The current qualitative study included 59 parents who participated in substudy of two linked multilevel studies-EAT 2010 (Eating and Activity in Teens) and Families and Eating and Activity in Teens (F-EAT). Parents (91.5% female) were racially/ethnically and socioeconomically diverse. Data were analyzed using a grounded theory approach. Results from the current study suggest that parents from both single- and dual-headed households have similar perspectives regarding why family meals are protective for healthful eating habits for adolescents (eg, provides structure/routine, opportunities for communication, connection), but provide similar and different reasons for barriers to family meals (eg, single-headed=cost vs dual-headed=lack of creativity) and ideas and suggestions for how to increase the frequency of family meals (eg, single-headed=give fewer options vs dual-headed=include children in the meal preparation). Findings can help inform public health intervention researchers and providers who work with adolescents and their families to understand how to approach discussions regarding reasons for having family meals, barriers to carrying out family meals, and ways to increase family meals depending on family structure. PMID

  7. Space mission scenario development and performance analysis tool

    NASA Technical Reports Server (NTRS)

    Kordon, Mark; Baker, John; Gilbert, John; Hanks, David

    2004-01-01

    This paper discusses a new and innovative approach for a rapid spacecraft multi-disciplinary performance analysis using a tool called the Mission Scenario Development Workbench (MSDW). To meet the needs of new classes of space missions, analysis tools with proven models were developed and integrated into a framework to enable rapid trades and analyses between spacecraft designs and operational scenarios during the formulation phase of a mission. Generally speaking, spacecraft resources are highly constrained on deep space missions and this approach makes it possible to maximize the use of existing resources to attain the best possible science return. This approach also has the potential benefit of reducing the risk of costly design changes made later in the design cycle necessary to meet the mission requirements by understanding system design sensitivities early and adding appropriate margins. This paper will describe the approach used by the Mars Science Laboratory Project to accomplish this result.

  8. Launch Window Trade Analysis for the James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Yu, Wayne H.; Richon, Karen

    2014-01-01

    The James Webb Space Telescope (JWST) is a large-scale space telescope mission designed to study fundamental astrophysical questions ranging from the formation of the universe to the origin of planetary systems and the origins of life. JWSTs orbit design is a Libration Point Orbit (LPO) around the Sun-Earth/Moon (SEM) L2 point for a planned mission lifetime of 10.5 years. The launch readiness period for JWST is from Oct 1st, 2018 November 30th, 2018. This paper presents the first launch window analysis for the JWST observatory using finite-burn modeling; previous analysis assumed a single impulsive midcourse correction to achieve the mission orbit. The physical limitations of the JWST hardware stemming primarily from propulsion, communication and thermal requirements alongside updated mission design requirements result in significant launch window within the launch readiness period. Future plans are also discussed.

  9. James Webb Space Telescope Launch Window Trade Analysis

    NASA Technical Reports Server (NTRS)

    Yu, Wayne; Richon, Karen

    2014-01-01

    The James Webb Space Telescope (JWST) is a large-scale space telescope mission designed to study fundamental astrophysical questions ranging from the formation of the universe to the origin of planetary systems and the origins of life. JWSTs orbit design is a Libration Point Orbit (LPO) around the Sun-EarthMoon (SEM) L2 point for a planned mission lifetime of 10.5 years. The launch readiness period for JWST is from Oct 1st, 2018 November 30th, 2018. This paper presents the first launch window analysis for the JWST observatory using finite-burn modeling; previous analysis assumed a single impulsive midcourse correction to achieve the mission orbit. The physical limitations of the JWST hardware stemming primarily from propulsion, communication and thermal requirements alongside updated mission design requirements result in significant launch window within the launch readiness period. Future plans are also discussed.

  10. Environmental analysis of the chemical release module. [space shuttle payload

    NASA Technical Reports Server (NTRS)

    Heppner, J. P.; Dubin, M.

    1980-01-01

    The environmental analysis of the Chemical Release Module (a free flying spacecraft deployed from the space shuttle to perform chemical release experiments) is reviewed. Considerations of possible effects of the injectants on human health, ionosphere, weather, ground based optical astronomical observations, and satellite operations are included. It is concluded that no deleterious environmental effects of widespread or long lasting nature are anticipated from chemical releases in the upper atmosphere of the type indicated for the program.

  11. Energy consumption analysis for the Mars deep space station

    NASA Technical Reports Server (NTRS)

    Hayes, N. V.

    1982-01-01

    Results for the energy consumption analysis at the Mars deep space station are presented. It is shown that the major energy consumers are the 64-Meter antenna building and the operations support building. Verification of the antenna's energy consumption is highly dependent on an accurate knowlege of the tracking operations. The importance of a regular maintenance schedule for the watt hour meters installed at the station is indicated.

  12. Mathematical analysis techniques for modeling the space network activities

    NASA Technical Reports Server (NTRS)

    Foster, Lisa M.

    1992-01-01

    The objective of the present work was to explore and identify mathematical analysis techniques, and in particular, the use of linear programming. This topic was then applied to the Tracking and Data Relay Satellite System (TDRSS) in order to understand the space network better. Finally, a small scale version of the system was modeled, variables were identified, data was gathered, and comparisons were made between actual and theoretical data.

  13. Parametric analysis of lunar resources for space energy systems

    NASA Astrophysics Data System (ADS)

    Woodcock, Gordon R.

    The possible use of lunar resource in the construction of solar power satellites (SPS) to provide energy for use on earth is discussed. The space transportation and operational aspects of the SPS program are compared to other energy concepts. Cost/benefit analysis are used to study the advantages of using lunar oxygen for the SPS program and producing helium-3 on the moon. Options for lunar surface power are considered and the economic benefits of using lunar resources are examined.

  14. The Space Tug economic analysis study - What we learned

    NASA Technical Reports Server (NTRS)

    Hopkins, C. V.

    1975-01-01

    This paper summarizes the scope, analytical methods, and principal findings of a recently performed Space-Tug economic analysis. Both the Shuttle/Tug transportation system and its unmanned payloads were modeled in this study. A variety of upper-stage concepts capable of fulfilling the Tug mission were evaluated against this model, and the 'best' Tug concepts were identified for a range of economic measures.

  15. Statistical Analysis of Micrometeoroid and Space Debris Impacts on the Space Station "Salyut-4"

    NASA Astrophysics Data System (ADS)

    Rebrikov, V. N.

    2009-03-01

    It is common to consider the flow of micrometeoroids and space debris (MM/SD) as the Poisson one when calculating risks for spaceship [1]. However even the first studies of the near Earth space with the aid of spaceships where sensors of particle registrations have been set allow us to suppose that registered streams have very complex features [2-3].The objective of this work is the statistical analysis of MM/SD registration data onboard station "Salut-4" and specification of their distribution models in the near Earth. As initial data we used results of studies performed on stations "Salyut-4" and obtained with the help of the control system. This system was used for detecting of the MM/SD impacts and consisted of condenser sensors (CS) and an electronic device.

  16. Determination of space use by laying hens using kinematic analysis.

    PubMed

    Mench, Joy A; Blatchford, Richard A

    2014-04-01

    Two states in the United States now have legislation requiring that laying hens be provided with sufficient space to perform particular behaviors. To provide a framework for translating these performance standards into a space requirement, kinematic analysis was used to measure the amount of space needed for White Leghorn hens to stand, turn around 180°, lie down, and wing flap. Hyline W-36 hens (n = 9) were marked on the tops of their heads and the tips of both wings and 3 toes with black livestock marker. Each hen was then placed in a floor pen (91.4 × 91.4 cm) and filmed using 2 high-speed cameras. The resulting images were processed using a software program that generated 3-dimensional space use for each behavior. Because none of the hens lay down in the test pen, the 2-dimensional space required for lying was determined by superimposing a grid over videos of the hens lying down in their home cages. On average, hens required a mean area of 563 (± 8) cm(2) to stand, 1,316 (± 23) cm(2) to turn around, 318 (± 6) cm(2) to lie down, and 1,693 (± 136) cm(2) to wing flap. The mean heights used were 34.8 (± 1.3) cm for standing, 38.6 (± 2.3) cm for turning, and 49.5 (± 1.8) cm for wing flapping. However, space requirements for hens housed in multiple-hen groups in cage or noncage systems cannot be based simply on information about the space required for local movement by a single hen. It must also incorporate consideration of the tendency of hens in a flock to synchronize their behaviors. In addition, it must include not just local movement space but also the space that hens may need to use for longer-distance movements to access resources such as food, water, perches, and nest boxes. PMID:24706955

  17. Safety Analysis of Dual Purpose Metal Cask Subjected to Impulsive Loads due to Aircraft Engine Crash

    NASA Astrophysics Data System (ADS)

    Shirai, Koji; Namba, Kosuke; Saegusa, Toshiari

    In Japan, the first Interim Storage Facility of spent nuclear fuel away from reactor site is being planned to start its commercial operation around 2010, in use of dual-purpose metal cask in the northern part of Main Japan Island. Business License Examination for safety design approval has started since March, 2007. To demonstrate the more scientific and rational performance of safety regulation activities on each phase for the first license procedure, CREPEI has executed demonstration tests with full scale casks, such as drop tests onto real targets without impact limiters(1) and seismic tests subjected to strong earthquake motions(2). Moreover, it is important to develop the knowledge for the inherent security of metal casks under extreme mechanical-impact conditions, especially for increasing interest since the terrorist attacks from 11th September 2001(3)-(6). This paper presents dynamic mechanical behavior of the metal cask lid closure system caused by direct aircraft engine crash and describes calculated results (especially, leak tightness based on relative dynamic displacements between metallic seals). Firstly, the local penetration damage of the interim storage facility building by a big passenger aircraft engine crash (diameter 2.7m, length 4.3m, weight 4.4ton, impact velocity 90m/s) has been examined. The reduced velocity is calculated by the local damage formula for concrete structure with its thickness of 70cm. The load vs. time function for this reduced velocity (60m/s) is estimated by the impact analysis using Finite Element code LS-DYNA with the full scale engine model onto a hypothetically rigid target. Secondly, as the most critical scenarios for the metal cask, two impact scenarios (horizontal impact hitting the cask and vertical impact onto the lid metallic seal system) are chosen. To consider the geometry of all bolts for two lids, the gasket reaction forces and the inner pressure of the cask cavity, the detailed three dimensional FEM models are

  18. Modal Analysis and Correlation of International Space Station Early Configurations

    NASA Technical Reports Server (NTRS)

    Kaouk, Mohamed; Shein, Shya-Ling; Kim, Hyoung M.

    2000-01-01

    This paper will summarize the modal analysis and model refinement results for the International Space Station (ISS) Flight-2A mated configuration. To maintain structural integrity of the ISS, structural loading distributions have been rigorously analyzed through numerical simulation and taken into account during the design of the structure and mission operations. The accuracy of the analysis results is directly affected by the precision of mathematical models and estimated input forces. A mathematical model of an ISS configuration is composed of individual component math models. Each component model is required to be correlated with ground test data.

  19. Procedures for analysis of debris relative to Space Shuttle systems

    NASA Technical Reports Server (NTRS)

    Kim, Hae Soo; Cummings, Virginia J.

    1993-01-01

    Debris samples collected from various Space Shuttle systems have been submitted to the Microchemical Analysis Branch. This investigation was initiated to develop optimal techniques for the analysis of debris. Optical microscopy provides information about the morphology and size of crystallites, particle sizes, amorphous phases, glass phases, and poorly crystallized materials. Scanning electron microscopy with energy dispersive spectrometry is utilized for information on surface morphology and qualitative elemental content of debris. Analytical electron microscopy with wavelength dispersive spectrometry provides information on the quantitative elemental content of debris.

  20. Nonlinear bulk viscosity in FRW cosmology: a phase space analysis.

    NASA Astrophysics Data System (ADS)

    Acquaviva, G.; Beesham, A.

    2015-11-01

    We consider a Friedmann-Robertson-Walker spacetime filled with both viscous radiation and nonviscous dust. The former has a bulk viscosity that is proportional to an arbitrary power of the energy density, i.e. \\zeta \\propto {ρ }{{v}}ν , and viscous pressure satisfying a nonlinear evolution equation. The analysis is carried out in the context of dynamical systems and the properties of solutions corresponding to the fixed points are discussed. For some ranges of the relevant parameter ν we find that the trajectories in the phase space evolve from a FRW singularity towards an asymptotic de Sitter attractor, confirming and extending previous analysis in the literature.

  1. System Sensitivity Analysis Applied to the Conceptual Design of a Dual-Fuel Rocket SSTO

    NASA Technical Reports Server (NTRS)

    Olds, John R.

    1994-01-01

    This paper reports the results of initial efforts to apply the System Sensitivity Analysis (SSA) optimization method to the conceptual design of a single-stage-to-orbit (SSTO) launch vehicle. SSA is an efficient, calculus-based MDO technique for generating sensitivity derivatives in a highly multidisciplinary design environment. The method has been successfully applied to conceptual aircraft design and has been proven to have advantages over traditional direct optimization methods. The method is applied to the optimization of an advanced, piloted SSTO design similar to vehicles currently being analyzed by NASA as possible replacements for the Space Shuttle. Powered by a derivative of the Russian RD-701 rocket engine, the vehicle employs a combination of hydrocarbon, hydrogen, and oxygen propellants. Three primary disciplines are included in the design - propulsion, performance, and weights & sizing. A complete, converged vehicle analysis depends on the use of three standalone conceptual analysis computer codes. Efforts to minimize vehicle dry (empty) weight are reported in this paper. The problem consists of six system-level design variables and one system-level constraint. Using SSA in a 'manual' fashion to generate gradient information, six system-level iterations were performed from each of two different starting points. The results showed a good pattern of convergence for both starting points. A discussion of the advantages and disadvantages of the method, possible areas of improvement, and future work is included.

  2. Performance analysis of a dual-tree algorithm for computing spatial distance histograms.

    PubMed

    Chen, Shaoping; Tu, Yi-Cheng; Xia, Yuni

    2011-08-01

    Many scientific and engineering fields produce large volume of spatiotemporal data. The storage, retrieval, and analysis of such data impose great challenges to database systems design. Analysis of scientific spatiotemporal data often involves computing functions of all point-to-point interactions. One such analytics, the Spatial Distance Histogram (SDH), is of vital importance to scientific discovery. Recently, algorithms for efficient SDH processing in large-scale scientific databases have been proposed. These algorithms adopt a recursive tree-traversing strategy to process point-to-point distances in the visited tree nodes in batches, thus require less time when compared to the brute-force approach where all pairwise distances have to be computed. Despite the promising experimental results, the complexity of such algorithms has not been thoroughly studied. In this paper, we present an analysis of such algorithms based on a geometric modeling approach. The main technique is to transform the analysis of point counts into a problem of quantifying the area of regions where pairwise distances can be processed in batches by the algorithm. From the analysis, we conclude that the number of pairwise distances that are left to be processed decreases exponentially with more levels of the tree visited. This leads to the proof of a time complexity lower than the quadratic time needed for a brute-force algorithm and builds the foundation for a constant-time approximate algorithm. Our model is also general in that it works for a wide range of point spatial distributions, histogram types, and space-partitioning options in building the tree. PMID:21804753

  3. Three-Dimensional Analysis of Deep Space Network Antenna Coverage

    NASA Technical Reports Server (NTRS)

    Kegege, Obadiah; Fuentes, Michael; Meyer, Nicholas; Sil, Amy

    2012-01-01

    There is a need to understand NASA s Deep Space Network (DSN) coverage gaps and any limitations to provide redundant communication coverage for future deep space missions, especially for manned missions to Moon and Mars. The DSN antennas are required to provide continuous communication coverage for deep space flights, interplanetary missions, and deep space scientific observations. The DSN consists of ground antennas located at three sites: Goldstone in USA, Canberra in Australia, and Madrid in Spain. These locations are not separated by the exactly 120 degrees and some DSN antennas are located in the bowl-shaped mountainous terrain to shield against radiofrequency interference resulting in a coverage gap in the southern hemisphere for the current DSN architecture. To analyze the extent of this gap and other coverage limitations, simulations of the DSN architecture were performed. In addition to the physical properties of the DSN assets, the simulation incorporated communication forward link calculations and azimuth/elevation masks that constrain the effects of terrain for each DSN antenna. Analysis of the simulation data was performed to create coverage profiles with the receiver settings at a deep space altitudes ranging from 2 million to 10 million km and a spherical grid resolution of 0.25 degrees with respect to longitude and latitude. With the results of these simulations, two- and three-dimensional representations of the area without communication coverage and area with coverage were developed, showing the size and shape of the communication coverage gap projected in space. Also, the significance of this communication coverage gap is analyzed from the simulation data.

  4. Modal Analysis and Model Correlation of the Mir Space Station

    NASA Technical Reports Server (NTRS)

    Kim, Hyoung M.; Kaouk, Mohamed

    2000-01-01

    This paper will discuss on-orbit dynamic tests, modal analysis, and model refinement studies performed as part of the Mir Structural Dynamics Experiment (MiSDE). Mir is the Russian permanently manned Space Station whose construction first started in 1986. The MiSDE was sponsored by the NASA International Space Station (ISS) Phase 1 Office and was part of the Shuttle-Mir Risk Mitigation Experiment (RME). One of the main objectives for MiSDE is to demonstrate the feasibility of performing on-orbit modal testing on large space structures to extract modal parameters that will be used to correlate mathematical models. The experiment was performed over a one-year span on the Mir-alone and Mir with a Shuttle docked. A total of 45 test sessions were performed including: Shuttle and Mir thruster firings, Shuttle-Mir and Progress-Mir dockings, crew exercise and pushoffs, and ambient noise during night-to-day and day-to-night orbital transitions. Test data were recorded with a variety of existing and new instrumentation systems that included: the MiSDE Mir Auxiliary Sensor Unit (MASU), the Space Acceleration Measurement System (SAMS), the Russian Mir Structural Dynamic Measurement System (SDMS), the Mir and Shuttle Inertial Measurement Units (IMUs), and the Shuttle payload bay video cameras. Modal analysis was performed on the collected test data to extract modal parameters, i.e. frequencies, damping factors, and mode shapes. A special time-domain modal identification procedure was used on free-decay structural responses. The results from this study show that modal testing and analysis of large space structures is feasible within operational constraints. Model refinements were performed on both the Mir alone and the Shuttle-Mir mated configurations. The design sensitivity approach was used for refinement, which adjusts structural properties in order to match analytical and test modal parameters. To verify the refinement results, the analytical responses calculated using

  5. Sea state monitoring over Socotra Rock (Ieodo) by dual polarization SAR image analysis

    NASA Astrophysics Data System (ADS)

    Choi, Y.; Kim, J.; Yun, H.; yun, H.

    2013-12-01

    The application SAR in sea state monitoring have been conducted in the large number of fields such as the vessel tracing using the wake in SAR amplitude, the measurement of sea wave height and the oil spill detection. The true merit of SAR application in sea state monitoring is the full independence from the climate conditions. Hence, it is highly useful to secure safety of the anthropogenic activities in ocean and the understanding of the marine environment. Especially the dual and full polarization modes of new L band and X band SAR such as Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR)'s Fine Beam double Polarization (FDB) and Polarimetry mode (PLR) and terraSAR-X polarization mode provided innovative means to extract sea state information exploiting the different amplitude and phase angle responses by electromagnetic and sea wave interactions. Thus a sample projects for mining the maximum possible sea state information from the ALOS PLASAR FDB SAR/InSAR pairs compared with the in-suit observation of sea state is being conducted. Test site was established over Socotra Rock (Ieodo in Korean), which is located at the Western Sea of Korea. At first, it aimed the measurement of sea waves using ALOS PLASAR multi-polarization images and its doppler-shift analysis. Together with sea state monitoring, auxiliary data analyses to combine the sea state outputs with the other in-orbital sensing image and non image information to trace the influence of sea states in the marine environment are actively undergoing. For instance, MERIS chlorophyll-a products are under investigation to identify the correlation with sea state. However, an significant obstacles to apply SAR interpretation scheme for mining sea state is the temporal gap between SAR image acquisitions in spite of the improved revising time of contemporary in-orbital SAR sensors. To tackle this problem, we are also introducing the multi view angle optical sensor

  6. Analysis of the Space Propulsion System Problem Using RAVEN

    SciTech Connect

    diego mandelli; curtis smith; cristian rabiti; andrea alfonsi

    2014-06-01

    This paper presents the solution of the space propulsion problem using a PRA code currently under development at Idaho National Laboratory (INL). RAVEN (Reactor Analysis and Virtual control ENviroment) is a multi-purpose Probabilistic Risk Assessment (PRA) software framework that allows dispatching different functionalities. It is designed to derive and actuate the control logic required to simulate the plant control system and operator actions (guided procedures) and to perform both Monte- Carlo sampling of random distributed events and Event Tree based analysis. In order to facilitate the input/output handling, a Graphical User Interface (GUI) and a post-processing data-mining module are available. RAVEN allows also to interface with several numerical codes such as RELAP5 and RELAP-7 and ad-hoc system simulators. For the space propulsion system problem, an ad-hoc simulator has been developed and written in python language and then interfaced to RAVEN. Such simulator fully models both deterministic (e.g., system dynamics and interactions between system components) and stochastic behaviors (i.e., failures of components/systems such as distribution lines and thrusters). Stochastic analysis is performed using random sampling based methodologies (i.e., Monte-Carlo). Such analysis is accomplished to determine both the reliability of the space propulsion system and to propagate the uncertainties associated to a specific set of parameters. As also indicated in the scope of the benchmark problem, the results generated by the stochastic analysis are used to generate risk-informed insights such as conditions under witch different strategy can be followed.

  7. Computational analysis of gene expression space associated with metastatic cancer

    PubMed Central

    2009-01-01

    Background Prostate carcinoma is among the most common types of cancer affecting hundreds of thousands people every year. Once the metastatic form of prostate carcinoma is documented, the majority of patients die from their tumors as opposed to other causes. The key to successful treatment is in the earliest possible diagnosis, as well as understanding the molecular mechanisms of metastatic progression. A number of recent studies have identified multiple biomarkers for metastatic progression. However, most of the studies consider only direct comparison between metastatic and non-metastatic classes of samples. Results We propose an alternative concept of analysis that considers the entire multidimensional space of gene expression and identifies the partition of this space in which metastatic development is possible. To apply this concept in cancer gene expression studies we utilize a modification of high-dimension natural taxonomy algorithm FOREL. Our analysis of microarray data containing primary and metastatic cancer samples has revealed not only differentially expressed genes, but also relations between different groups of primary and metastatic cancer. Metastatic samples tend to occupy a distinct partition of gene expression space. Further pathway analysis suggests that this partition is delineated by a specific pattern of gene expression in cytoskeleton remodeling, cell adhesion and apoptosis/cell survival pathways. We compare our findings with both report of original analysis and recent studies in molecular mechanism of metastasis. Conclusion Our analysis indicates a single molecular mechanism of metastasis. The new approach does not contradict previously reported findings, but reveals important details unattainable with traditional methodology. PMID:19811690

  8. Space Operations Center System Analysis: Requirements for a Space Operations Center, revision A

    NASA Technical Reports Server (NTRS)

    Woodcock, G. R.

    1982-01-01

    The system and program requirements for a space operations center as defined by systems analysis studies are presented as a guide for future study and systems definition. Topics covered include general requirements for safety, maintainability, and reliability, service and habitat modules, the health maintenance facility; logistics modules; the docking tunnel; and subsystem requirements (structures, electrical power, environmental control/life support; extravehicular activity; data management; communications and tracking; docking/berthing; flight control/propulsion; and crew support). Facilities for flight support, construction, satellite and mission servicing, and fluid storage are included as well as general purpose support equipment.

  9. Economic analysis of open space box model utilization in spacecraft

    NASA Astrophysics Data System (ADS)

    Mohammad, Atif F.; Straub, Jeremy

    2015-05-01

    It is a known fact that the amount of data about space that is stored is getting larger on an everyday basis. However, the utilization of Big Data and related tools to perform ETL (Extract, Transform and Load) applications will soon be pervasive in the space sciences. We have entered in a crucial time where using Big Data can be the difference (for terrestrial applications) between organizations underperforming and outperforming their peers. The same is true for NASA and other space agencies, as well as for individual missions and the highly-competitive process of mission data analysis and publication. In most industries, conventional opponents and new candidates alike will influence data-driven approaches to revolutionize and capture the value of Big Data archives. The Open Space Box Model is poised to take the proverbial "giant leap", as it provides autonomic data processing and communications for spacecraft. We can find economic value generated from such use of data processing in our earthly organizations in every sector, such as healthcare, retail. We also can easily find retailers, performing research on Big Data, by utilizing sensors driven embedded data in products within their stores and warehouses to determine how these products are actually used in the real world.

  10. The MATHEMATICA economic analysis of the Space Shuttle System

    NASA Technical Reports Server (NTRS)

    Heiss, K. P.

    1973-01-01

    Detailed economic analysis shows the Thrust Assisted Orbiter Space Shuttle System (TAOS) to be the most economic Space Shuttle configuration among the systems studied. The development of a TAOS Shuttle system is economically justified within a level of space activities between 300 and 360 Shuttle flights in the 1979-1990 period, or about 25 to 30 flights per year, well within the U.S. Space Program including NASA and DoD missions. If the NASA and DoD models are taken at face value (624 flights), the benefits of the Shuttle system are estimated to be $13.9 billion with a standard deviation of plus or minus $1.45 billion in 1970 dollars (at a 10% social rate of discount). If the expected program is modified to 514 flights (in the 1979-1990 period), the estimated benefits of the Shuttle system are $10.2 billion, with a standard deviation of $940 million (at a 10% social rate of discount).

  11. Results and Analysis from Space Suit Joint Torque Testing

    NASA Technical Reports Server (NTRS)

    Matty, Jennifer

    2010-01-01

    A space suit's mobility is critical to an astronaut's ability to perform work efficiently. As mobility increases, the astronaut can perform tasks for longer durations with less fatigue. Mobility can be broken down into two parts: range of motion (ROM) and torque. These two measurements describe how the suit moves and how much force it takes to move. Two methods were chosen to define mobility requirements for the Constellation Space Suit Element (CSSE). One method focuses on range of motion and the second method centers on joint torque. A joint torque test was conducted to determine a baseline for current advanced space suit joint torques. This test utilized the following space suits: Extravehicular Mobility Unit (EMU), Advanced Crew Escape Suit (ACES), I-Suit, D-Suit, Enhanced Mobility (EM)- ACES, and Mark III (MK-III). Data was collected data from 16 different joint movements of each suit. The results were then reviewed and CSSE joint torque requirement values were selected. The focus of this paper is to discuss trends observed during data analysis.

  12. Qualitative analysis of irregular fields delivered with dual electron multileaf collimator: A Monte Carlo study

    NASA Astrophysics Data System (ADS)

    Inyang, Samuel Okon; Chamberlain, Alan

    2016-03-01

    The use of a dual electron multileaf collimator (eMLC) to collimate therapeutic electron beam without the use of cutouts has been previously shown to be feasible. Further Monte Carlo simulations were performed in this study to verify the nature and appearance of the isodose distribution in water phantom of irregular electron beams delivered by the eMLC. Electron fields used in this study were selected to reflect those used in electron beam therapy. Results of this study show that the isodose distribution in a water phantom obtained from the simulation of irregular electron beams through the eMLC conforms to the pattern of the eMLC used in the delivery of the beam. It is therefore concluded that the dual eMLC could deliver isodose distributions reflecting the pattern of the eMLC field that was used in the delivery of the beam.

  13. ERS-1 radial position refinement by dual crossover analysis with TOPEX/Poseidon

    NASA Astrophysics Data System (ADS)

    Carnochan, S.; Moore, P.; Ehlers, S.

    Achieving orbital accuracies in the radial direction for ERS-1 commensurate with those for TOPEX/Poseidon is of utmost importance for the integration of the two altimeter data sets. This paper outlines a procedure whereby the radial orbit error for ERS-1 is recovered as a time series expansion in the form of a finite Fourier series with additional terms for atmospheric drag, solar radiation pressure, and initial state vector mismodelling. Using a least squares collocation method with constraints derived from the JGM2 gravity field co-variance matrix, the radial error is recovered using both dual crossovers and ERS-1 single satellite crossovers. Aggregate arcs are then used to derive the ERS-1 orbit error over the repeat period of 35 days. The results are presented in the improvement of fit in the dual crossover, ERS-1 crossover and altimetry data sets as well as the recovery of an altimeter bias for the two satellites.

  14. Analysis of calibration materials to improve dual-energy CT scanning for petrophysical applications

    SciTech Connect

    Ayyalasomavaiula, K.; McIntyre, D.; Jain, J.; Singh, J.; Yueh, F.

    2011-01-01

    Dual energy CT-scanning is a rapidly emerging imaging technique employed in non-destructive evaluation of various materials. Although CT (Computerized Tomography) has been used for characterizing rocks and visualizing and quantifying multiphase flow through rocks for over 25 years, most of the scanning is done at a voltage setting above 100 kV for taking advantage of the Compton scattering (CS) effect, which responds to density changes. Below 100 kV the photoelectric effect (PE) is dominant which responds to the effective atomic numbers (Zeff), which is directly related to the photo electric factor. Using the combination of the two effects helps in better characterization of reservoir rocks. The most common technique for dual energy CT-scanning relies on homogeneous calibration standards to produce the most accurate decoupled data. However, the use of calibration standards with impurities increases the probability of error in the reconstructed data and results in poor rock characterization. This work combines ICP-OES (inductively coupled plasma optical emission spectroscopy) and LIBS (laser induced breakdown spectroscopy) analytical techniques to quantify the type and level of impurities in a set of commercially purchased calibration standards used in dual-energy scanning. The Zeff data on the calibration standards with and without impurity data were calculated using the weighted linear combination of the various elements present and used in calculating Zeff using the dual energy technique. Results show 2 to 5% difference in predicted Zeff values which may affect the corresponding log calibrations. The effect that these techniques have on improving material identification data is discussed and analyzed. The workflow developed in this paper will translate to a more accurate material identification estimates for unknown samples and improve calibration of well logging tools.

  15. Analysis of a generalized dual reflector antenna system using physical optics

    NASA Technical Reports Server (NTRS)

    Acosta, Roberto J.; Lagin, Alan R.

    1992-01-01

    Reflector antennas are widely used in communication satellite systems because they provide high gain at low cost. Offset-fed single paraboloids and dual reflector offset Cassegrain and Gregorian antennas with multiple focal region feeds provide a simple, blockage-free means of forming multiple, shaped, and isolated beams with low sidelobes. Such antennas are applicable to communications satellite frequency reuse systems and earth stations requiring access to several satellites. While the single offset paraboloid has been the most extensively used configuration for the satellite multiple-beam antenna, the trend toward large apertures requiring minimum scanned beam degradation over the field of view 18 degrees for full earth coverage from geostationary orbit may lead to impractically long focal length and large feed arrays. Dual reflector antennas offer packaging advantages and more degrees of design freedom to improve beam scanning and cross-polarization properties. The Cassegrain and Gregorian antennas are the most commonly used dual reflector antennas. A computer program for calculating the secondary pattern and directivity of a generalized dual reflector antenna system was developed and implemented at LeRC. The theoretical foundation for this program is based on the use of physical optics methodology for describing the induced currents on the sub-reflector and main reflector. The resulting induced currents on the main reflector are integrated to obtain the antenna far-zone electric fields. The computer program is verified with other physical optics programs and with measured antenna patterns. The comparison shows good agreement in far-field sidelobe reproduction and directivity.

  16. Space Operations Analysis Using the Synergistic Engineering Environment

    NASA Technical Reports Server (NTRS)

    Angster, Scott; Brewer, Laura

    2002-01-01

    The Synergistic Engineering Environment has been under development at the NASA Langley Research Center to aid in the understanding of the operations of spacecraft. This is accomplished through the integration of multiple data sets, analysis tools, spacecraft geometric models, and a visualization environment to create an interactive virtual simulation of the spacecraft. Initially designed to support the needs of the International Space Station, the SEE has broadened the scope to include spacecraft ranging from low-earth orbit to deep space missions. Analysis capabilities within the SEE include rigid body dynamics, kinematics, orbital mechanics, and payload operations. This provides the user the ability to perform real-time interactive engineering analyses in areas including flight attitudes and maneuvers, visiting vehicle docking scenarios, robotic operations, plume impingement, field of view obscuration, and alternative assembly configurations. The SEE has been used to aid in the understanding of several operational procedures related to the International Space Station. This paper will address the capabilities of the first build of the SEE, present several use cases of the SEE, and discuss the next build of the SEE.

  17. Probabilistic structural analysis methods for improving Space Shuttle engine reliability

    NASA Technical Reports Server (NTRS)

    Boyce, L.

    1989-01-01

    Probabilistic structural analysis methods are particularly useful in the design and analysis of critical structural components and systems that operate in very severe and uncertain environments. These methods have recently found application in space propulsion systems to improve the structural reliability of Space Shuttle Main Engine (SSME) components. A computer program, NESSUS, based on a deterministic finite-element program and a method of probabilistic analysis (fast probability integration) provides probabilistic structural analysis for selected SSME components. While computationally efficient, it considers both correlated and nonnormal random variables as well as an implicit functional relationship between independent and dependent variables. The program is used to determine the response of a nickel-based superalloy SSME turbopump blade. Results include blade tip displacement statistics due to the variability in blade thickness, modulus of elasticity, Poisson's ratio or density. Modulus of elasticity significantly contributed to blade tip variability while Poisson's ratio did not. Thus, a rational method for choosing parameters to be modeled as random is provided.

  18. Fatigue analysis of mini-mast space truss

    NASA Technical Reports Server (NTRS)

    Hwang, Shoi Y.

    1989-01-01

    The functional, structural adequacy of a 20 meter long generic space truss (Mini-Mast), subjected to fatigue loading, was examined with respect to the failure modes which are most likely to occur during services. The space truss is made of thin-walled tubes having unidirectional, zero degree layups of Celanese G50 graphite fibers/Narmco 5217 epoxy composites. The approach used to investigate the most probable failure mode of the truss under fatigue loading is to determine the stress level, including the types of stress, in the member first, then followed by failure mode analysis based on the stress level just determined. To begin, an approximate beam-parameter truss (BPT) model is analyzed first, followed by a detailed analysis of the truss using a finite element model (FEM) run with NASTRAN code. The response results of the BPT model are used to compare FEM results and to check any major deviation of trend derived from the FEM. The purpose of the work was to search available fatigue data of the tube material, to conduct approximate dynamical stress analysis of the BPT model, to run detailed dynamical stress analysis of the FEM model using NASTRAN code, and to predict the fatigue life of the truss member based on limited fatigue data.

  19. DQE analysis on a dual detector phase x-ray imaging system.

    PubMed

    Zhang, Da; Liu, Hong; Wu, Xizeng

    2008-09-21

    This study presents the characterization results of a newly developed dual detector in-line phase x-ray imaging prototype. Comparison of modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE) for both detectors was conducted when they worked in the dual detection mode, in which two images are acquired simultaneously at a single exposure. The MTFs of the two detectors are almost identical, showing that the blurring caused by detector1 does not significantly weaken the resolving power of detector2. With a 40 kVp and 4 cm thick BR-12 phantom filtered x-ray beam, the transmittance of detector1 was measured to be 32%. The characteristic response and DQE of the two detectors almost coincide, showing that the two detectors have similar imaging performance under the imaging conditions of this study. The DQE of detector2 at the different source to detector distances (SID) also demonstrate a high level of agreement, implying that the reduced exposure level caused by elongated SID did not degrade the performance significantly. The study validated the design of the dual detection configuration for phase x-ray imaging, which has the potential for improving the accuracy of diagnostics at clinically acceptable radiation doses. PMID:18723931

  20. Light scattering Q-space analysis of irregularly shaped particles

    NASA Astrophysics Data System (ADS)

    Heinson, Yuli W.; Maughan, Justin B.; Heinson, William R.; Chakrabarti, Amitabha; Sorensen, Christopher M.

    2016-01-01

    We report Q-space analysis of light scattering phase function data for irregularly shaped dust particles and of theoretical model output to describe them. This analysis involves plotting the scattered intensity versus the magnitude of the scattering wave vector q = (4π/λ)sin(θ/2), where λ is the optical wavelength and θ is the scattering angle, on a double-logarithmic plot. In q-space all the particle shapes studied display a scattering pattern which includes a q-independent forward scattering regime; a crossover, Guinier regime when q is near the inverse size; a power law regime; and an enhanced backscattering regime. Power law exponents show a quasi-universal functionality with the internal coupling parameter ρ'. The absolute value of the exponents start from 4 when ρ' < 1, the diffraction limit, and decreases as ρ' increases until a constant 1.75 ± 0.25 when ρ' ≳ 10. The diffraction limit exponent implies that despite their irregular structures, all the particles studied have mass and surface scaling dimensions of Dm = 3 and Ds = 2, respectively. This is different from fractal aggregates that have a power law equal to the fractal dimension Df because Df = Dm = Ds < 3. Spheres have Dm = 3 and Ds = 2 but do not show a single power law nor the same functionality with ρ'. The results presented here imply that Q-space analysis can differentiate between spheres and these two types of irregularly shaped particles. Furthermore, they are applicable to analysis of the contribution of aerosol radiative forcing to climate change and of aerosol remote sensing data.

  1. Shear-induced rigidity of frictional particles: Analysis of emergent order in stress space

    NASA Astrophysics Data System (ADS)

    Sarkar, Sumantra; Bi, Dapeng; Zhang, Jie; Ren, Jie; Behringer, R. P.; Chakraborty, Bulbul

    2016-04-01

    Solids are distinguished from fluids by their ability to resist shear. In equilibrium systems, the resistance to shear is associated with the emergence of broken translational symmetry as exhibited by a nonuniform density pattern that is persistent, which in turn results from minimizing the free energy. In this work, we focus on a class of systems where this paradigm is challenged. We show that shear-driven jamming in dry granular materials is a collective process controlled by the constraints of mechanical equilibrium. We argue that these constraints can lead to a persistent pattern in a dual space that encodes the statistics of contact forces and the topology of the contact network. The shear-jamming transition is marked by the appearance of this persistent pattern. We investigate the structure and behavior of patterns both in real space and the dual space as the system evolves through the rigidity transition for a range of packing fractions and in two different shear protocols. We show that, in the protocol that creates homogeneous jammed states without shear bands, measures of shear jamming do not depend on strain and packing fraction independently but obey a scaling form with a packing-fraction-dependent characteristic strain that goes to zero at the isotropic jamming point ϕJ. We demonstrate that it is possible to define a protocol-independent order parameter in this dual space, which provides a quantitative measure of the rigidity of shear-jammed states.

  2. Expert systems for space power supply - Design, analysis, and evaluation

    NASA Technical Reports Server (NTRS)

    Cooper, Ralph S.; Thomson, M. Kemer; Hoshor, Alan

    1987-01-01

    The feasibility of applying expert systems to the conceptual design, analysis, and evaluation of space power supplies in particular, and complex systems in general is evaluated. To do this, the space power supply design process and its associated knowledge base were analyzed and characterized in a form suitable for computer emulation of a human expert. The existing expert system tools and the results achieved with them were evaluated to assess their applicability to power system design. Some new concepts for combining program architectures (modular expert systems and algorithms) with information about the domain were applied to create a 'deep' system for handling the complex design problem. NOVICE, a code to solve a simplified version of a scoping study of a wide variety of power supply types for a broad range of missions, has been developed, programmed, and tested as a concrete feasibility demonstration.

  3. Improved Conjunction Analysis via Collaborative Space Situational Awareness

    NASA Astrophysics Data System (ADS)

    Kelso, T. S.; Vallado, D.; Chan, J.; Buckwalter, B.

    2009-03-01

    Satellite operators are becoming increasingly aware of the threat of on-orbit collisions—between satellites or with orbital debris. Successful conjunction monitoring and collision avoidance activities require accurate orbital information for as many space objects as possible. Current sources of orbital data are of low fidelity, as a result of how those data are generated, and are of limited value to conjunction analysis. However, satellite operators have much better data for their own satellites. When that data is shared among operators, overall space situational awareness can be significantly improved. This paper will demonstrate the potential improvements and discuss an operational implementation— SOCRATES-GEO—which uses operator data to improve conjunction monitoring.

  4. Statistical analysis of static shape control in space structures

    NASA Technical Reports Server (NTRS)

    Burdisso, Ricardo A.; Haftka, Raphael T.

    1990-01-01

    The article addresses the problem of efficient analysis of the statistics of initial and corrected shape distortions in space structures. Two approaches for improving efficiency are considered. One is an adjoint technique for calculating distortion shapes: the second is a modal expansion of distortion shapes in terms of pseudo-vibration modes. The two techniques are applied to the problem of optimizing actuator locations on a 55 m radiometer antenna. The adjoint analysis technique is used with a discrete-variable optimization method. The modal approximation technique is coupled with a standard conjugate-gradient continuous optimization method. The agreement between the two sets of results is good, validating both the approximate analysis and optimality of the results.

  5. An analysis of the Space Shuttle hypersonic entry trim anomaly

    NASA Technical Reports Server (NTRS)

    Young, J. C.; Findlay, J. T.

    1985-01-01

    This paper reviews a parameter identification methodology developed to investigate the hypersonic longitudinal trim misprediction apparent in the NASA Space Shuttle Orbiter entry flights. The method combines an analysis using a measured versus predicted technique in conjunction with a multilinear regression analysis to identify prediction deficiencies using quasi-static longitudinal data in the hypersonic flight regime (Mach 6 through 26). In general, the results of this extraction confirm results previously obtained by other Shuttle investigators with the exception of elevon effectiveness. Further analysis and/or flight data will be required to resolve the conflicting elevon results. A combination of this analytical tool and other flight data will enable flight data interpretation with the potential for identifying the sources of the Shuttle's hypersonic trim misprediction to an accuracy consistent with updating preflight prediction methodology for future spacecraft.

  6. Motivation and Dual Enrollment: An Analysis of the Motivation of High School Students to Participate in Dual Enrollment in Association of Christian Schools International Schools

    ERIC Educational Resources Information Center

    Salerno, Mitchell Acri

    2011-01-01

    A phenomenological study utilizing the Consensual Qualitative Research method was conducted to understand the motivation of high school students dually enrolled in high school and college, commonly referred to as dual enrollment, in relation to the Self-Determination Theory and to connect this motivation to research on personal calling. This…

  7. Separating Leaves from Trunks and Branches with Dual-Wavelength Terrestrial Lidar Scanning: Improving Canopy Structure Characterization in 3-D Space

    NASA Astrophysics Data System (ADS)

    Li, Z.; Strahler, A. H.; Schaaf, C.; Howe, G.; Martel, J.; Hewawasam, K.; Douglas, E. S.; Chakrabarti, S.; Cook, T.; Paynter, I.; Saenz, E.; Wang, Z.; Yang, X.; Yao, T.; Zhao, F.; Woodcock, C.; Jupp, D.; Schaefer, M.; Culvenor, D.; Newnham, G.; Lowell, J.

    2013-12-01

    Leaf area index (LAI) is an important parameter characterizing forest structure, used in models regulating the exchange of carbon, water and energy between the land and the atmosphere. However, optical methods in common use cannot separate leaf area from the area of upper trunks and branches, and thus retrieve only plant area index (PAI), which is adjusted to LAI using an appropriate empirical woody-to-total index. An additional problem is that the angular distributions of leaf normals and normals to woody surfaces are quite different, and thus leafy and woody components project quite different areas with varying zenith angle of view. This effect also causes error in LAI retrieval using optical methods. Full-waveform scans at both the NIR (1064 nm) and SWIR (1548 nm) wavelengths from the new terrestrial Lidar, the Dual-Wavelength Echidna Lidar (DWEL), which pulses in both wavelengths simultaneously, easily separate returns of leaves from trunks and branches in 3-D space. In DWEL scans collected at two different forest sites, Sierra National Forest in June 2013 and Brisbane Karawatha Forest Park in July 2013, the power returned from leaves is similar to power returned from trunks/branches at the NIR wavelength, whereas the power returned from leaves is much lower (only about half as large) at the SWIR wavelength. At the SWIR wavelength, the leaf scattering is strongly attenuated by liquid water absorption. Normalized difference index (NDI) images from the waveform mean intensity at the two wavelengths demonstrate a clear contrast between leaves and trunks/branches. The attached image shows NDI from a part of a scan of an open red fir stand in the Sierra National Forest. Leaves appear light, while other objects are darker.Dual-wavelength point clouds generated from the full waveform data show weaker returns from leaves than from trunks/branches. A simple threshold classification of the NDI value of each scattering point readily separates leaves from trunks and

  8. Reentry heat transfer analysis of the space shuttle orbiter

    NASA Technical Reports Server (NTRS)

    Ko, W. L.; Quinn, R. D.; Gong, L.

    1982-01-01

    A structural performance and resizing finite element thermal analysis computer program was used in the reentry heat transfer analysis of the space shuttle. Two typical wing cross sections and a midfuselage cross section were selected for the analysis. The surface heat inputs to the thermal models were obtained from aerodynamic heating analyses, which assumed a purely turbulent boundary layer, a purely laminar boundary layer, separated flow, and transition from laminar to turbulent flow. The effect of internal radiation was found to be quite significant. With the effect of the internal radiation considered, the wing lower skin temperature became about 39 C (70 F) lower. The results were compared with fight data for space transportation system, trajectory 1. The calculated and measured temperatures compared well for the wing if laminar flow was assumed for the lower surface and bay one upper surface and if separated flow was assumed for the upper surfaces of bays other than bay one. For the fuselage, good agreement between the calculated and measured data was obtained if laminar flow was assumed for the bottom surface. The structural temperatures were found to reach their peak values shortly before touchdown. In addition, the finite element solutions were compared with those obtained from the conventional finite difference solutions.

  9. Analysis of the Space Shuttle main engine simulation

    NASA Technical Reports Server (NTRS)

    Deabreu-Garcia, J. Alex; Welch, John T.

    1993-01-01

    This is a final report on an analysis of the Space Shuttle Main Engine Program, a digital simulator code written in Fortran. The research was undertaken in ultimate support of future design studies of a shuttle life-extending Intelligent Control System (ICS). These studies are to be conducted by NASA Lewis Space Research Center. The primary purpose of the analysis was to define the means to achieve a faster running simulation, and to determine if additional hardware would be necessary for speeding up simulations for the ICS project. In particular, the analysis was to consider the use of custom integrators based on the Matrix Stability Region Placement (MSRP) method. In addition to speed of execution, other qualities of the software were to be examined. Among these are the accuracy of computations, the useability of the simulation system, and the maintainability of the program and data files. Accuracy involves control of truncation error of the methods, and roundoff error induced by floating point operations. It also involves the requirement that the user be fully aware of the model that the simulator is implementing.

  10. Probabilistic Analysis of Space Shuttle Body Flap Actuator Ball Bearings

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.; Jett, Timothy R.; Predmore, Roamer E.; Zaretsky, Erin V.

    2007-01-01

    A probabilistic analysis, using the 2-parameter Weibull-Johnson method, was performed on experimental life test data from space shuttle actuator bearings. Experiments were performed on a test rig under simulated conditions to determine the life and failure mechanism of the grease lubricated bearings that support the input shaft of the space shuttle body flap actuators. The failure mechanism was wear that can cause loss of bearing preload. These tests established life and reliability data for both shuttle flight and ground operation. Test data were used to estimate the failure rate and reliability as a function of the number of shuttle missions flown. The Weibull analysis of the test data for a 2-bearing shaft assembly in each body flap actuator established a reliability level of 99.6 percent for a life of 12 missions. A probabilistic system analysis for four shuttles, each of which has four actuators, predicts a single bearing failure in one actuator of one shuttle after 22 missions (a total of 88 missions for a 4-shuttle fleet). This prediction is comparable with actual shuttle flight history in which a single actuator bearing was found to have failed by wear at 20 missions.

  11. Probabilistic Analysis of Space Shuttle Body Flap Actuator Ball Bearings

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.; Jett, Timothy R.; Predmore, Roamer E.; Zaretsky, Erwin V.

    2008-01-01

    A probabilistic analysis, using the 2-parameter Weibull-Johnson method, was performed on experimental life test data from space shuttle actuator bearings. Experiments were performed on a test rig under simulated conditions to determine the life and failure mechanism of the grease lubricated bearings that support the input shaft of the space shuttle body flap actuators. The failure mechanism was wear that can cause loss of bearing preload. These tests established life and reliability data for both shuttle flight and ground operation. Test data were used to estimate the failure rate and reliability as a function of the number of shuttle missions flown. The Weibull analysis of the test data for the four actuators on one shuttle, each with a 2-bearing shaft assembly, established a reliability level of 96.9 percent for a life of 12 missions. A probabilistic system analysis for four shuttles, each of which has four actuators, predicts a single bearing failure in one actuator of one shuttle after 22 missions (a total of 88 missions for a 4-shuttle fleet). This prediction is comparable with actual shuttle flight history in which a single actuator bearing was found to have failed by wear at 20 missions.

  12. Reentry heat transfer analysis of the space shuttle orbiter

    NASA Astrophysics Data System (ADS)

    Ko, W. L.; Quinn, R. D.; Gong, L.

    A structural performance and resizing finite element thermal analysis computer program was used in the reentry heat transfer analysis of the space shuttle. Two typical wing cross sections and a midfuselage cross section were selected for the analysis. The surface heat inputs to the thermal models were obtained from aerodynamic heating analyses, which assumed a purely turbulent boundary layer, a purely laminar boundary layer, separated flow, and transition from laminar to turbulent flow. The effect of internal radiation was found to be quite significant. With the effect of the internal radiation considered, the wing lower skin temperature became about 39 C (70 F) lower. The results were compared with fight data for space transportation system, trajectory 1. The calculated and measured temperatures compared well for the wing if laminar flow was assumed for the lower surface and bay one upper surface and if separated flow was assumed for the upper surfaces of bays other than bay one. For the fuselage, good agreement between the calculated and measured data was obtained if laminar flow was assumed for the bottom surface. The structural temperatures were found to reach their peak values shortly before touchdown. In addition, the finite element solutions were compared with those obtained from the conventional finite difference solutions.

  13. A comparative analysis of Medicaid long-term care policies and their effects on elderly dual enrollees.

    PubMed

    Rice, J Bradford; Kasper, Judith D; Pezzin, Liliana E

    2009-03-01

    Individuals with dual enrollment in Medicare and Medicaid have become the focus of heightened US federal and state policy interest in recent years. These beneficiaries are among the most vulnerable and costly persons served by either program. This analysis uses a reduced-form econometric model and a unique survey of community-resident dual enrollees to take a critical step toward understanding the relationships and combinations of state long-term care (LTC) policies and their relative effectiveness in achieving their intended effects: increasing access to care, improving activities of daily living/instrumental activities of daily living (ADL/IADL) assistance, and reducing unmet needs. We then simulate the effects of alternative policies to determine the most effective combination.The combination of policies that was most effective in reducing the percentage of individuals receiving low levels of assistance was high spending in the community relative to nursing home and low community LTC spending per recipient; that is, spending more on community care and spreading it across more people. Overall, this analysis confirms that Medicaid LTC policy decisions by states, and the combinations of policies that are implemented, result in important variations in levels of assistance to elderly persons with disabilities. PMID:18464296

  14. Management of the Space Physics Analysis Network (SPAN)

    NASA Technical Reports Server (NTRS)

    Green, James L.; Thomas, Valerie L.; Butler, Todd F.; Peters, David J.; Sisson, Patricia L.

    1990-01-01

    Here, the purpose is to define the operational management structure and to delineate the responsibilities of key Space Physics Analysis Network (SPAN) individuals. The management structure must take into account the large NASA and ESA science research community by giving them a major voice in the operation of the system. Appropriate NASA and ESA interfaces must be provided so that there will be adequate communications facilities available when needed. Responsibilities are delineated for the Advisory Committee, the Steering Committee, the Project Scientist, the Project Manager, the SPAN Security Manager, the Internetwork Manager, the Network Operations Manager, the Remote Site Manager, and others.

  15. Comparative analysis of the space power architecture studies

    NASA Technical Reports Server (NTRS)

    Sovie, Ronald J.

    1988-01-01

    The Strategic Defense Initiative Organization (SDIO) has recently completed the initial phase of Space Power Architecture Studies (SPAS). The initial effort consisted of three major contracted efforts and a comparative analysis performed by the SDIO Independent Evaluation Group (IEG) and the IEG Field Support Team. The purpose of the SPAS effort was to evaluate a wide range of power systems for SDIO applications using a wide range of attributes other than power-system mass and volume. Open cycle, closed cycle, and closed power system/weapon platform concepts were studied. The purpose of this paper is to summarize the salient results of these studies, identify important trends and future study needs.

  16. Analysis of space tug operating techniques. Volume 2: Study results

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The design requirements for space tug systems and cost analysis of the refurbishment phases are discussed. The vehicle is an integral propulsion stage using liquid hydrogen and liquid oxygen as propellants and is capable of operating either as a fully or a partially autonomous vehicle. Structural features are an integral liquid hydrogen tank, a liquid oxygen tank, a meteoroid shield, an aft conical docking and structural support ring, and a staged combustion main engine. The vehicle is constructed of major modules for ease of maintenance. Line drawings and block diagrams are included to explain the maintenance requirements for the subsystems.

  17. Space-Time Cluster Analysis of Invasive Meningococcal Disease

    PubMed Central

    de Melker, Hester; Spanjaard, Lodewijk; Dankert, Jacob; Nagelkerke, Nico

    2004-01-01

    Clusters are recognized when meningococcal cases of the same phenotypic strain (markers: serogroup, serotype, and subtype) occur in spatial and temporal proximity. The incidence of such clusters was compared to the incidence that would be expected by chance by using space-time nearest-neighbor analysis of 4,887 confirmed invasive meningococcal cases identified in the 9-year surveillance period 1993–2001 in the Netherlands. Clustering beyond chance only occurred among the closest neighboring cases (comparable to secondary cases) and was small (3.1%, 95% confidence interval 2.1%–4.1%). PMID:15498165

  18. Uniform color space analysis of LACIE image products

    NASA Technical Reports Server (NTRS)

    Nalepka, R. F. (Principal Investigator); Balon, R. J.; Cicone, R. C.

    1979-01-01

    The author has identified the following significant results. Analysis and comparison of image products generated by different algorithms show that the scaling and biasing of data channels for control of PFC primaries lead to loss of information (in a probability-of misclassification sense) by two major processes. In order of importance they are: neglecting the input of one channel of data in any one image, and failing to provide sufficient color resolution of the data. The scaling and biasing approach tends to distort distance relationships in data space and provides less than desirable resolution when the data variation is typical of a developed, nonhazy agricultural scene.

  19. Radiological risk analysis of potential SP-100 space mission scenarios

    SciTech Connect

    Bartram, B.W.; Weitzberg, A.

    1988-08-19

    This report presents a radiological risk analysis of three representative space mission scenarios utilizing a fission reactor. The mission profiles considered are: a high-altitude mission, launched by a TITAN IV launch vehicle, boosted by chemical upper stages into its operational orbit, a interplanetary nuclear electric propulsion (NEP) mission, started directly from a shuttle parking orbit, a low-altitude mission, launched by the Shuttle and boosted by a chemical stage to its operational orbit, with subsequent disposal boost after operation. 21 refs., 12 figs., 7 tabs.

  20. Decoding neural representational spaces using multivariate pattern analysis.

    PubMed

    Haxby, James V; Connolly, Andrew C; Guntupalli, J Swaroop

    2014-01-01

    A major challenge for systems neuroscience is to break the neural code. Computational algorithms for encoding information into neural activity and extracting information from measured activity afford understanding of how percepts, memories, thought, and knowledge are represented in patterns of brain activity. The past decade and a half has seen significant advances in the development of methods for decoding human neural activity, such as multivariate pattern classification, representational similarity analysis, hyperalignment, and stimulus-model-based encoding and decoding. This article reviews these advances and integrates neural decoding methods into a common framework organized around the concept of high-dimensional representational spaces. PMID:25002277

  1. Analysis of space radiation data of semiconductor memories

    NASA Technical Reports Server (NTRS)

    Stassinopoulos, E. G.; Brucker, G. J.; Stauffer, C. A.

    1996-01-01

    This article presents an analysis of radiation effects for several select device types and technologies aboard the Combined Release and Radiation Effects Satellite (CRRES) satellite. These space-flight measurements covered a period of about 14 months of mission lifetime. Single Event Upset (SEU) data of the investigated devices from the Microelectronics Package (MEP) were processed and analyzed. Valid upset measurements were determined by correcting for invalid readings, hard failures, missing data tapes (thus voids in data), and periods over which devices were disabled from interrogation. The basic resolution time of the measurement system was confirmed to be 2 s. Lessons learned, important findings, and recommendations are presented.

  2. Methodology of design and analysis of external walls of space station for hypervelocity impacts by meteoroids and space debris

    NASA Technical Reports Server (NTRS)

    Batla, F. A.

    1986-01-01

    The development of criteria and methodology for the design and analysis of Space Station wall elements for collisions with meteoroids and space debris at hypervelocities is discussed. These collisions will occur at velocities of 10 km/s or more and can be damaging to the external wall elements of the Space Station. The wall elements need to be designed to protect the pressurized modules of the Space Station from functional or structural failure due to these collisions at hypervelocities for a given environment and population of meteoroids and space debris. The design and analysis approach and the associated computer program presented is to achieve this objective, including the optimization of the design for a required overall probability of no penetration. The approach is based on the presently available experimental and actual data on meteoroids and space debris flux and damage assessments and the empirical relationships resulting from the hypervelocity impact studies in laboratories.

  3. Space rescue system definition (system performance analysis and trades)

    NASA Astrophysics Data System (ADS)

    Housten, Sam; Elsner, Tim; Redler, Ken; Svendsen, Hal; Wenzel, Sheri

    This paper addresses key technical issues involved in the system definition of the Assured Crew Return Vehicle (ACRV). The perspective on these issues is that of a prospective ACRV contractor, performing system analysis and trade studies. The objective of these analyses and trade studies is to develop the recovery vehicle system concept and top level requirements. The starting point for this work is the definition of the set of design missions for the ACRV. This set of missions encompasses three classes of contingency/emergency (crew illness/injury, space station catastrophe/failure, transportation element catastrophe/failure). The need is to provide a system to return Space Station crew to Earth quickly (less than 24 hours) in response to randomly occurring contingency events over an extended period of time (30 years of planned Space Station life). The main topics addressed and characterized in this paper include the following: Key Recovery (Rescue) Site Access Considerations; Rescue Site Locations and Distribution; Vehicle Cross Range vs Site Access; On-orbit Loiter Capability and Vehicle Design; and Water vs. Land Recovery.

  4. Preliminary analysis of space mission applications for electromagnetic launchers

    NASA Technical Reports Server (NTRS)

    Miller, L. A.; Rice, E. E.; Earhart, R. W.; Conlon, R. J.

    1984-01-01

    The technical and economic feasibility of using electromagnetically launched EML payloads propelled from the Earth's surface to LEO, GEO, lunar orbit, or to interplanetary space was assessed. Analyses of the designs of rail accelerators and coaxial magnetic accelerators show that each is capable of launching to space payloads of 800 KG or more. A hybrid launcher in which EML is used for the first 2 KM/sec followed by chemical rocket stages was also tested. A cost estimates study shows that one to two EML launches per day are needed to break even, compared to a four-stage rocket. Development models are discussed for: (1) Earth orbital missions; (2) lunar base supply mission; (3) solar system escape mission; (4) Earth escape missions; (5) suborbital missions; (6) electromagnetic boost missions; and (7) space-based missions. Safety factors, environmental impacts, and EML systems analysis are discussed. Alternate systems examined include electrothermal thrustors, an EML rocket gun; an EML theta gun, and Soviet electromagnetic accelerators.

  5. Dual scale trend analysis to evaluate climatic and anthropogenic effects on the vegetated land surface in agricultural Russia

    NASA Astrophysics Data System (ADS)

    de Beurs, Kirsten; Henebry, Geoffrey

    2010-05-01

    Russia's population is projected to shrink by a staggering 29% by 2050. Differential dynamics among rural populations are correlated with ethnicity and constitute a key driver in the spatial disintegration of rural Russia. Currently, Russia is slowly transitioning into a country with an internal "archipelago" of islands of productive agriculture around cities set within a matrix of much less productive and abandoned croplands. This heterogeneous spatial pattern is mainly driven by depopulation of the least favorable parts of the countryside, where "least favorable" is some function of lower fertility of land, higher remoteness from urban markets, or both. Our aim is to improve current understanding of the interactions of climate change and the spatio-temporal impacts of agricultural reform in European Russia. We present a dual scale trend analysis to characterize change in agricultural European Russia. We selected a global NASA MODIS product (MCD43C4 and MCD43A4) at a 0.05° (~5.6 km) and 500m spatial resolution and a 16-day temporal resolution from 2000 through 2008. We applied a refinement of the Seasonal Kendal trend method to Normalized Difference Vegetation Index (NDVI) image series at both scales. We only incorporated composites during the vegetative growing season which was delineated by start of season and end of season estimates based on analysis of Normalized Difference Infrared Index (NDII) data. Trend patterns revealed areas of increasing NDVI trend in Russia which was linked through the dual scale analysis with agricultural land cover change. The coarser scale analysis was relevant to atmospheric boundary layer processes, while the finer scale data revealed trends that were more relevant to human decision-making and regional economics. We evaluated the weather patterns and land surface phenologies for the areas with increasing NDVI over the past 9 years and compared the results with agricultural areas without change. This analysis improved our

  6. An Analysis of Gravity-Field Estimation Based on Intersatellite Dual-1-Way Biased Ranging

    NASA Technical Reports Server (NTRS)

    Thomas, J. B.

    1999-01-01

    The GRACE (Gravity Recovery And Climate Experiment) mission is designed to make global, highly accurate measurements of the Earth's gravity field with high spatial resolution. Ancillary GPS occultation measurements are also to be carried out for atmospheric monitoring. In the dual-1-way biased ranging of this mission, the range between two satellites separated by 100 to 200 km in nearly polar, coplanar, circular orbits, is measured to very high precision, to within an additive constant, through the exchange of K- and Ka-band sinusoidal signals. Such biased ranging data, along with GPS L-band range and phase data, can be processed and fit over successive multiday intervals to obtain accurate estimates of the Earth's gravity field. This report approximately models and analyzes this process, from the generation of the RF signals at the two satellites through the extraction of the geopotential. The steps include generation of the transmitted signals, processing the received signals to extract high-rate baseband phase, carrying out a dual-1-way combination of baseband phase to extract high-rate biased range for each band, combining K- and Ka-band ranges to correct for the ionosphere effect, and processing the resulting high-rate biased range values to extract three types of reduced-rate observables: biased range, range rate and range acceleration. The version of dual-1-way biased ranging developed by this report improves upon previous versions in a number of ways: highly accurate satellite-timetag corrections derived from concurrent GPS data, better baseband phase extraction using highly digital processing, highly accurate USO-rate calibration derived from concurrent GPS data, an improved method for extracting high-rate biased range from baseband phase, improved filtering for extracting reduced- rate observables from high-rate biased range, and parallel extraction of three observable types.

  7. Electron Backscatter Diffraction Analysis of Joints Between AISI 316L Austenitic/UNS S32750 Dual-Phase Stainless Steel

    NASA Astrophysics Data System (ADS)

    Shamanian, Morteza; Mohammadnezhad, Mahyar; Amini, Mahdi; Zabolian, Azam; Szpunar, Jerzy A.

    2015-08-01

    Stainless steels are among the most economical and highly practicable materials widely used in industrial areas due to their mechanical and corrosion resistances. In this study, a dissimilar weld joint consisting of an AISI 316L austenitic stainless steel (ASS) and a UNS S32750 dual-phase stainless steel was obtained under optimized welding conditions by gas tungsten arc welding technique using AWS A5.4:ER2594 filler metal. The effect of welding on the evolution of the microstructure, crystallographic texture, and micro-hardness distribution was also studied. The weld metal (WM) was found to be dual-phased; the microstructure is obtained by a fully ferritic solidification mode followed by austenite precipitation at both ferrite boundaries and ferrite grains through solid-state transformation. It is found that welding process can affect the ferrite content and grain growth phenomenon. The strong textures were found in the base metals for both steels. The AISI 316L ASS texture is composed of strong cube component. In the UNS S32750 dual-phase stainless steel, an important difference between the two phases can be seen in the texture evolution. Austenite phase is composed of a major cube component, whereas the ferrite texture mainly contains a major rotated cube component. The texture of the ferrite is stronger than that of austenite. In the WM, Kurdjumov-Sachs crystallographic orientation relationship is found in the solidification microstructure. The analysis of the Kernel average misorientation distribution shows that the residual strain is more concentrated in the austenite phase than in the other phase. The welding resulted in a significant hardness increase in the WM compared to initial ASS.

  8. Dual mode microwave tool for dielectric analysis and thermal ablation treatment of organic tissue.

    PubMed

    Puentes, Margarita; Bashir, Fahed; Schüssler, Martin; Jakoby, Rolf

    2012-01-01

    A dual mode tool design to analyze organic tissue and locally perform thermal ablation treatment is presented. The tool is made of an array of split-ring resonators. It can operate on a sensing mode to track the relative dielectric changes from the organic tissue and on a treatment mode to perform thermal ablation at different input powers. The measurements were done with phantoms of human tissue. The tool is able to focus a hot spot of approximately 0.2mm with a temperature of 109 °C at an input power of 10W. PMID:23366811

  9. Analysis of space systems study for the space disposal of nuclear waste. Study report, volume 1: Executive summary. Final report

    SciTech Connect

    Not Available

    1981-01-01

    Space systems concepts were identified and defined and evaluated as to their performance, risks, and technical viability in order to select the most attractive approach for disposal of high level nuclear wastes in space. Major study areas discussed include: (1) mission and operations analysis (2) waste payload systems (3) flight support system (4) launch site systems (5) launch vehicle systems (6) orbit transfer system (7) space disposal destinations and (8) systems integration and evaluation.

  10. Analysis of space systems study for the space disposal of nuclear waste. Study report, volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Space systems concepts were identified and defined and evaluated as to their performance, risks, and technical viability in order to select the most attractive approach for disposal of high level nuclear wastes in space. Major study areas discussed include: (1) mission and operations analysis; (2) waste payload systems; (3) flight support system; (4) launch site systems; (5) launch vehicle systems; (6) orbit transfer system; (7) space disposal destinations; and (8) systems integration and evaluation.

  11. Analysis of the Thermo-Elastic Response of Space Reflectors to Simulated Space Environment

    NASA Astrophysics Data System (ADS)

    Allegri, G.; Ivagnes, M. M.; Marchetti, M.; Poscente, F.

    2002-01-01

    The evaluation of space environment effects on materials and structures is a key matter to develop a proper design of long duration missions: since a large part of satellites operating in the earth orbital environment are employed for telecommunications, the development of space antennas and reflectors featured by high dimensional stability versus space environment interactions represents a major challenge for designers. The structural layout of state of the art space antennas and reflectors is very complex, since several different sensible elements and materials are employed: particular care must be placed in evaluating the actual geometrical configuration of the reflectors operating in the space environment, since very limited distortions of the designed layout can produce severe effects on the quality of the signal both received and transmitted, especially for antennas operating at high frequencies. The effects of thermal loads due to direct sunlight exposition and to earth and moon albedo can be easily taken into account employing the standard methods of structural analysis: on the other hand the thermal cycling and the exposition to the vacuum environment produce a long term damage accumulation which affects the whole structure. The typical effects of the just mentioned exposition are the outgassing of polymeric materials and the contamination of the exposed surface, which can affect sensibly the thermo-mechanical properties of the materials themselves and, therefore, the structural global response. The main aim of the present paper is to evaluate the synergistic effects of thermal cycling and of the exposition to high vacuum environment on an innovative antenna developed by Alenia Spazio S.p.a.: to this purpose, both an experimental and numerical research activity has been developed. A complete prototype of the antenna has been exposed to the space environment simulated by the SAS facility: this latter is constituted by an high vacuum chamber, equipped by

  12. Analysis and design of ion thrusters for large space systems

    NASA Technical Reports Server (NTRS)

    James, E. L.

    1980-01-01

    This study undertakes the analysis and conceptual design of a 0.5 Newton electrostatic ion thruster suitable for use on large space system missions in the next decade. Either argon or xenon gas shall be used as propellant. A 50 cm diameter discharge chamber was selected to meet stipulated performance goals. The discharge plasma is contained at the boundary by a periodic structure of alternating permanent magnets generating a series of line cusps. Anode strips between the magnets collect Maxwellian electrons generated by a central cathode. Ion extraction utilizes either two or three grid optics at the user's choice. An extensive analysis was undertaken to investigate optics behavior in the high power environment of this large thruster. A plasma bridge neutralizer operating on inert gas provides charge neutralizing electrons to complete the design. The resulting conceptual thruster and the necessary power management and control requirements are described.

  13. Link Analysis for Space Communication Links Using ARQ Protocol

    NASA Technical Reports Server (NTRS)

    Cheung, Kar-Ming; Lau, Chi-Wung; Lee, Charles

    2014-01-01

    In space communications, standard link analysis assumes that messages are sent once. For a communication link that uses an error-correction coding scheme, bit-error-rate (BER) or frame-error-rate (FER), and link margins are common metrics that characterize the quality of a link, and they are used to determine the supportable data rate. With the advent of Automatic Repeat-reQuest (ARQ) protocols, when messages are corrupted during transmission, they can be resent multiple times automatically until they are correctly received and acknowledged. The concept of BER, FER, and link margin cannot be directly applied, and the link analysis approach for ARQ links needs to be re-examined.

  14. Probabilistic structural analysis of space propulsion system LOX post

    NASA Technical Reports Server (NTRS)

    Newell, J. F.; Rajagopal, K. R.; Ho, H. W.; Cunniff, J. M.

    1990-01-01

    The probabilistic structural analysis program NESSUS (Numerical Evaluation of Stochastic Structures Under Stress; Cruse et al., 1988) is applied to characterize the dynamic loading and response of the Space Shuttle main engine (SSME) LOX post. The design and operation of the SSME are reviewed; the LOX post structure is described; and particular attention is given to the generation of composite load spectra, the finite-element model of the LOX post, and the steps in the NESSUS structural analysis. The results are presented in extensive tables and graphs, and it is shown that NESSUS correctly predicts the structural effects of changes in the temperature loading. The probabilistic approach also facilitates (1) damage assessments for a given failure model (based on gas temperature, heat-shield gap, and material properties) and (2) correlation of the gas temperature with operational parameters such as engine thrust.

  15. Thermal analysis of the main mirror in space solar telescope

    NASA Astrophysics Data System (ADS)

    Li, Rong; Shi, Hu-li; Chen, Zhi-yuan

    2007-12-01

    For the design of a space solar telescope (SST), the large reflect mirror faces to the sun directly, which is in an abominable thermal condition with seriously thermal distortion. In this paper, it sets up the thermal mode and analyzes the temperature field and thermal distortion of the main mirror of SST. Further more, it uses the thermal design software SINDA/G (System Improved Numerical Differencing Analyzer/Gaski) and the finite element analysis software MSC.Patran to set up different models and various temperature distributions of the main mirror. Though comparing with these models, the paraboloid mirror model is confirmed, which becomes a reference to later thermal analysis of the whole SST.

  16. Discrete Fourier Transform Analysis in a Complex Vector Space

    NASA Technical Reports Server (NTRS)

    Dean, Bruce H.

    2009-01-01

    Alternative computational strategies for the Discrete Fourier Transform (DFT) have been developed using analysis of geometric manifolds. This approach provides a general framework for performing DFT calculations, and suggests a more efficient implementation of the DFT for applications using iterative transform methods, particularly phase retrieval. The DFT can thus be implemented using fewer operations when compared to the usual DFT counterpart. The software decreases the run time of the DFT in certain applications such as phase retrieval that iteratively call the DFT function. The algorithm exploits a special computational approach based on analysis of the DFT as a transformation in a complex vector space. As such, this approach has the potential to realize a DFT computation that approaches N operations versus Nlog(N) operations for the equivalent Fast Fourier Transform (FFT) calculation.

  17. Recent developments in thermal analysis of large space structures

    NASA Technical Reports Server (NTRS)

    Oneill, R. F.

    1983-01-01

    A numerical procedure for analysis of shadowed space heating of sparse structures, SSQ, is discussed. The SSQ program avoids inordinate computational complexity by confining attention to a single elemental location on a structural member of interest throughout an entire orbital period, proceeding then to similar treatment of individual alternate locations. The procedure considers a spacecraft in circular orbit and assumes fixed-Earth orientation of the spacecraft. Shadow orientation and interval duration, merged shadows, and computation of solar heat flux and thermal response are addressed. The output options of the SSQ FORTRAN 5 program and its efficiency are discussed. Application of the system to the analysis of a parabolic expandable truss antenna is considered.

  18. Compositional Solution Space Quantification for Probabilistic Software Analysis

    NASA Technical Reports Server (NTRS)

    Borges, Mateus; Pasareanu, Corina S.; Filieri, Antonio; d'Amorim, Marcelo; Visser, Willem

    2014-01-01

    Probabilistic software analysis aims at quantifying how likely a target event is to occur during program execution. Current approaches rely on symbolic execution to identify the conditions to reach the target event and try to quantify the fraction of the input domain satisfying these conditions. Precise quantification is usually limited to linear constraints, while only approximate solutions can be provided in general through statistical approaches. However, statistical approaches may fail to converge to an acceptable accuracy within a reasonable time. We present a compositional statistical approach for the efficient quantification of solution spaces for arbitrarily complex constraints over bounded floating-point domains. The approach leverages interval constraint propagation to improve the accuracy of the estimation by focusing the sampling on the regions of the input domain containing the sought solutions. Preliminary experiments show significant improvement on previous approaches both in results accuracy and analysis time.

  19. Dual-modality fiber-based OCT-TPL imaging system for simultaneous microstructural and molecular analysis of atherosclerotic plaques

    PubMed Central

    Wang, Tianyi; McElroy, Austin; Halaney, David; Vela, Deborah; Fung, Edmund; Hossain, Shafat; Phipps, Jennifer; Wang, Bingqing; Yin, Biwei; Feldman, Marc D.; Milner, Thomas E.

    2015-01-01

    New optical imaging techniques that provide contrast to study both the anatomy and composition of atherosclerotic plaques can be utilized to better understand the formation, progression and clinical complications of human coronary artery disease. We present a dual-modality fiber-based optical imaging system for simultaneous microstructural and molecular analysis of atherosclerotic plaques that combines optical coherence tomography (OCT) and two-photon luminescence (TPL) imaging. Experimental results from ex vivo human coronary arteries show that OCT and TPL optical contrast in recorded OCT-TPL images is complimentary and in agreement with histological analysis. Molecular composition (e.g., lipid and oxidized-LDL) detected by TPL imaging can be overlaid onto plaque microstructure depicted by OCT, providing new opportunities for atherosclerotic plaque identification and characterization. PMID:26137371

  20. Corticospinal activity during dual tasking: a systematic review and meta-analysis of TMS literature from 1995 to 2013.

    PubMed

    Corp, Daniel T; Lum, Jarrad A G; Tooley, Gregory A; Pearce, Alan J

    2014-06-01

    This systematic review and meta-analysis was conducted across studies using transcranial magnetic stimulation to investigate corticospinal excitability and inhibition in response to a dual task (DT). Quantitative analysis was performed on eleven controlled studies that had included healthy participants over the age of 18 years. Results showed a small effect size for increased corticospinal excitability for DT conditions (SMD=0.207; p=.217, and a small effect size (SMD=-0.253) demonstrating a significant decrease in corticospinal inhibition for DT conditions (p=.019). Meta-regression demonstrated that neither age, task type, or task prioritisation accounted for the high variability in effect sizes between studies. A number of possible sources of within study bias are identified, which reduced the level of evidence for study findings. The results show overall changes in corticospinal responses between ST and DT conditions; however further research is necessary to investigate variables that could account for differences in corticospinal responses between studies. PMID:24705270

  1. Analysis of debris from Spacelab Space Life Sciences-1

    NASA Astrophysics Data System (ADS)

    Caruso, S. V.; Rodgers, E. B.; Huff, T. L.

    1992-07-01

    Airborne microbiological and particulate contamination generated aboard Spacelab modules is a potential safety hazard. In order to shed light on the characteristics of these contaminants, microbial and chemical/particulate analyses were performed on debris vacuumed from cabin and avionics air filters in the Space Life Sciences-1 (SLS-1) module of the Space Transportation System 40 (STS-40) mission 1 month after landing. The debris was sorted into categories (e.g., metal, nonmetal, hair/fur, synthetic fibers, food particles, insect fragments, etc.). Elemental analysis of particles was done by energy dispersive analysis of x rays (metals) and Fourier transform infrared spectroscopy (nonmetals). Scanning electron micrographs were done of most particles. Microbiological samples were grown on R2A culture medium and identified. Clothing fibers dominated the debris by volume. Other particles, all attributed to the crew, resulted from abrasions and impacts during missions operations (e.g., paint chips, plastic, electronic scraps and clothing fibers). All bacterial species identified are commonly found in the atmosphere or on the human body. Bacillus sp. was the most frequently seen bacterium. One of the bacterial species, Enterobacter agglomerans, could cause illness in crew members with depressed immune systems.

  2. Analysis of International Space Station Vehicle Materials on MISSE 6

    NASA Technical Reports Server (NTRS)

    Finckenor, Miria; Golden, Johnny; Kravchenko, Michael; O'Rourke, Mary Jane

    2010-01-01

    The International Space Station Materials and Processes team has multiple material samples on MISSE 6, 7 and 8 to observe Low Earth Orbit (LEO) environmental effects on Space Station materials. Optical properties, thickness/mass loss, surface elemental analysis, visual and microscopic analysis for surface change are some of the techniques employed in this investigation. Results for the following MISSE 6 samples materials will be presented: deionized water sealed anodized aluminum; Hyzod(tm) polycarbonate used to temporarily protect ISS windows; Russian quartz window material; Beta Cloth with Teflon(tm) reformulated without perfluorooctanoic acid (PFOA), and electroless nickel. Discussion for current and future MISSE materials experiments will be presented. MISSE 7 samples are: more deionized water sealed anodized aluminum, including Photofoil(tm); indium tin oxide (ITO) over-coated Kapton(tm) used as thermo-optical surfaces; mechanically scribed tin-plated beryllium-copper samples for "tin pest" growth (alpha/beta transformation); and beta cloth backed with a black coating rather than aluminization. MISSE 8 samples are: exposed "scrim cloth" (fiberglass weave) from the ISS solar array wing material, protective fiberglass tapes and sleeve materials, and optical witness samples to monitor contamination.

  3. Analysis of debris from Spacelab Space Life Sciences-1

    NASA Technical Reports Server (NTRS)

    Caruso, S. V.; Rodgers, E. B.; Huff, T. L.

    1992-01-01

    Airborne microbiological and particulate contamination generated aboard Spacelab modules is a potential safety hazard. In order to shed light on the characteristics of these contaminants, microbial and chemical/particulate analyses were performed on debris vacuumed from cabin and avionics air filters in the Space Life Sciences-1 (SLS-1) module of the Space Transportation System 40 (STS-40) mission 1 month after landing. The debris was sorted into categories (e.g., metal, nonmetal, hair/fur, synthetic fibers, food particles, insect fragments, etc.). Elemental analysis of particles was done by energy dispersive analysis of x rays (metals) and Fourier transform infrared spectroscopy (nonmetals). Scanning electron micrographs were done of most particles. Microbiological samples were grown on R2A culture medium and identified. Clothing fibers dominated the debris by volume. Other particles, all attributed to the crew, resulted from abrasions and impacts during missions operations (e.g., paint chips, plastic, electronic scraps and clothing fibers). All bacterial species identified are commonly found in the atmosphere or on the human body. Bacillus sp. was the most frequently seen bacterium. One of the bacterial species, Enterobacter agglomerans, could cause illness in crew members with depressed immune systems.

  4. Space-Time Analysis of Crime Patterns in Central London

    NASA Astrophysics Data System (ADS)

    Cheng, T.; Williams, D.

    2012-07-01

    Crime continues to cast a shadow over citizen well-being in big cities today, while also imposing huge economic and social costs. Timely understanding of how criminality emerges and how crime patterns evolve is crucial to anticipating crime, dealing with it when it occurs and developing public confidence in the police service. Every day, about 10,000 crime incidents are reported by citizens, recorded and geo-referenced in the London Metropolitan Police Service Computer Aided Dispatch (CAD) database. The unique nature of this dataset allows the patterns to be explored at particularly fine temporal granularity and at multiple spatial resolutions. This study provides a framework for the exploratory spatio-temporal analysis of crime patterns that combines visual inquiry tools (interactive animations, space-time cubes and map matrices) with cluster analysis (spatial-temporal scan statistics and the self-organizing map). This framework is tested on the CAD dataset for the London Borough of Camden in March 2010. Patterns of crime through space and time are discovered and the clustering methods were evaluated on their ability to facilitate the discovery and interpretation of these patterns.

  5. Improvement of the radial positioning of ERS-1 through dual crossover analysis with TOPEX/Poseidon

    NASA Astrophysics Data System (ADS)

    Carnochan, S.; Moore, P.; Ehlers, S.; Lam, C.; Woodworth, P.

    1994-01-01

    A method where both dual crossovers and single satellite crossovers are used in conjunction to determine the radial error for both Topology Ocean Experiment (TOPEX)/Poseidon and ERS-1 as a finite Fourier series, is outlined. The procedure is based on a time series expansion of the radial orbit error of ERS-1 expressed in terms of a finite Fourier series at frequencies of multiples of 1/501 cycles per revolution (for the 35 day repeat orbit), with additional terms for atmospheric drag and solar radiation pressure mismodeling as well as errors in the initial state vector. Refinement of the ERS-1 positioning is presented from solutions utilizing both the dual crossover data set by itself and in combination with ERS-1 crossover data. The zero frequency term or constant offset in the time series expansion of the ERS-1 radial orbit error is a measure of the difference between the so called altimeter biases on TOPEX/Poseidon and ERS-1. Preliminary results of this difference are presented and compared against results for both satellites from long arc orbits.

  6. Analysis of Plume Impingement Effects from Orion Crew Service Module Dual Reaction Control System Engine Firings

    NASA Technical Reports Server (NTRS)

    Prisbell, Andrew; Marichalar, J.; Lumpkin, F.; LeBeau, G.

    2010-01-01

    Plume impingement effects on the Orion Crew Service Module (CSM) were analyzed for various dual Reaction Control System (RCS) engine firings and various configurations of the solar arrays. The study was performed using a decoupled computational fluid dynamics (CFD) and Direct Simulation Monte Carlo (DSMC) approach. This approach included a single jet plume solution for the R1E RCS engine computed with the General Aerodynamic Simulation Program (GASP) CFD code. The CFD solution was used to create an inflow surface for the DSMC solution based on the Bird continuum breakdown parameter. The DSMC solution was then used to model the dual RCS plume impingement effects on the entire CSM geometry with deployed solar arrays. However, because the continuum breakdown parameter of 0.5 could not be achieved due to geometrical constraints and because high resolution in the plume shock interaction region is desired, a focused DSMC simulation modeling only the plumes and the shock interaction region was performed. This high resolution intermediate solution was then used as the inflow to the larger DSMC solution to obtain plume impingement heating, forces, and moments on the CSM and the solar arrays for a total of 21 cases that were analyzed. The results of these simulations were used to populate the Orion CSM Aerothermal Database.

  7. Analysis of Plume Impingement Effects from Orion Crew Service Module Dual Reaction Control System Engine Firings

    NASA Astrophysics Data System (ADS)

    Prisbell, A.; Marichalar, J.; Lumpkin, F.; LeBeau, G.

    2011-05-01

    Plume impingement effects on the Orion Crew Service Module (CSM) were analyzed for various dual Reaction Control System (RCS) engine firings and various configurations of the solar arrays. The study was performed using a decoupled computational fluid dynamics (CFD) and Direct Simulation Monte Carlo (DSMC) approach. This approach included a single jet plume solution for the R1E RCS engine computed with the General Aerodynamic Simulation Program (GASP) CFD code. The CFD solution was used to create an inflow surface for the DSMC solution based on the Bird continuum breakdown parameter. The DSMC solution was then used to model the dual RCS plume impingement effects on the entire CSM geometry with deployed solar arrays. However, because the continuum breakdown parameter of 0.05 could not be achieved due to geometrical constraints and because high resolution in the plume shock interaction region is desired, a focused DSMC simulation modeling only the plumes and the shock interaction region was performed. This high resolution intermediate solution was then used as the inflow to the larger DSMC solution to obtain plume impingement heating, forces, and moments on the CSM and the solar arrays for a total of 21 cases that were analyzed. The results of these simulations were used to populate the Orion CSM Aerothermal Database.

  8. An experimental analysis of the dual gate emitter switched thyristor (DG-EST)

    NASA Astrophysics Data System (ADS)

    Sawant, Shankar; Sridhar, S.; Baliga, B. Jayant

    1999-10-01

    In recent years, various dual MOS gated thyristor structures have been proposed to improve the three pronged trade-off of forward voltage drop, turn-off time and forward biased safe operating area when compared to single gate devices. The dual gate emitter switched thyristor (DG-EST), with its unique thyristor current partitioning mechanism, has been reported to posses superior characteristics when compared to conventional single gate ESTs. In this paper, a detailed study of the device physics of operation of the DG-EST is presented, supported by two dimensional numerical simulations. Effects of variations in the floating emitter length, lifetime in the drift region and temperature on the forward voltage drop are experimentally observed. An analytical model predicting the maximum controllable current density ( JMCC) of the DG-EST is reported and confirmed through experimental measurements. The DG-EST is found to have a superior trade-off curve of on-state voltage drop versus turn-off time when compared to the conventional emitter switched thyristor (C-EST).

  9. Spacelab data analysis using the space plasma computer analysis network (SCAN) system

    NASA Technical Reports Server (NTRS)

    Green, J. L.

    1984-01-01

    The Space-plasma Computer Analysis Network (SCAN) currently connects a large number of U.S. Spacelab investigators into a common computer network. Used primarily by plasma physics researchers at present, SCAN provides access to Spacelab investigators in other areas of space science, to Spacelab and non-Spacelab correlative data bases, and to large Class VI computational facilities for modeling. SCAN links computers together at remote institutions used by space researchers, utilizing commercially available software for computer-to-computer communications. Started by the NASA's Office of Space Science in mid 1980, SCAN presently contains ten system nodes located at major universities and space research laboratories, with fourteen new nodes projected for the near future. The Stanford University computer gateways allow SCAN users to connect onto the ARPANET and TELENET overseas networks.

  10. ToF-SIMS Depth Profiling of Organic Films: A Comparison between Single Beam and Dual-beam Analysis

    PubMed Central

    Brison, J.; Muramoto, S.; Castner, David G.

    2010-01-01

    In dual-beam depth profiling, a high energy analysis beam and a lower energy etching beam are operated in series. Although the fluence of the analysis beam is usually kept well below the static SIMS limit, complete removal of the damage induced by the high energy analysis beam while maintaining a good depth resolution is difficult. In this study a plasma polymerized tetraglyme film is used as the model organic system and the dimensionless parameter R, (analysis beam fluence)/(total ion fluence), is introduced to quantify the degree of sample damage induced as a function of the analysis beam fluence. It was observed for a constant C60+ etching beam fluence, increasing the analysis fluence (and consequently increasing the R parameter) increased in the amount of damage accumulated in the sample. For Bin+ (n = 1 and 3) and C60+ depth profiling, minimal damage accumulation was observed up to R = 0.03, with a best depth resolution of 8 nm. In general, an increase in the Bin+ analysis fluence above this value resulted in a decrease in the molecular signals of the steady state region of the depth profile and a degradation of the depth resolution at the polymer/substrate interface. PMID:20383274

  11. Maintenance of proximal bone mass with an uncemented femoral stem analysis with dual-energy x-ray absorptiometry.

    PubMed

    Wixson, R L; Stulberg, S D; Van Flandern, G J; Puri, L

    1997-06-01

    Bone ingrowth into uncemented femoral implants with proximal porous coatings has been designed to avoid proximal stress shielding and preserve femoral strength. Dual-energy x-ray absorptiometry allows repeated quantitative analysis of anteroposterior scans of the proximal femur. By use of dual-energy x-ray absorptiometry and qualitative radiographic changes, 31 total hip arthroplasties with an individually designed, proximally porous-coated prosthesis were evaluated after surgery and at intervals up to 2 years. All implants appeared to achieve successful bone ingrowth and subsequent remodeling. At the most proximal level around the neck osteotomy, the postoperative loss of bone density at 6 months was -14.5%, which persisted at 24 months with -11.6%. At the level of the distal portion of the porous coating in the lower metaphysis, the density change was -8.7%, but bone had remodeled at 24 months with a change in density of only -1.0% compared with the immediate postoperative scan. With a design that results in reliable proximal ingrowth, this study predicts that after an initial decline in bone density, a positive bone remodeling response occurs that could lead to long-term stable fixation of the femoral implant. PMID:9195311

  12. Vertical guidance performance analysis of the L1-L5 dual-frequency GPS/WAAS user avionics sensor.

    PubMed

    Jan, Shau-Shiun

    2010-01-01

    This paper investigates the potential vertical guidance performance of global positioning system (GPS)/wide area augmentation system (WAAS) user avionics sensor when the modernized GPS and Galileo are available. This paper will first investigate the airborne receiver code noise and multipath (CNMP) confidence (σair). The σair will be the dominant factor in the availability analysis of an L1-L5 dual-frequency GPS/WAAS user avionics sensor. This paper uses the MATLAB Algorithm Availability Simulation Tool (MAAST) to determine the required values for the σair, so that an L1-L5 dual-frequency GPS/WAAS user avionics sensor can meet the vertical guidance requirements of APproach with Vertical guidance (APV) II and CATegory (CAT) I over conterminous United States (CONUS). A modified MAAST that includes the Galileo satellite constellation is used to determine under what user configurations WAAS could be an APV II system or a CAT I system over CONUS. Furthermore, this paper examines the combinations of possible improvements in signal models and the addition of Galileo to determine if GPS/WAAS user avionics sensor could achieve 10 m Vertical Alert Limit (VAL) within the service volume. Finally, this paper presents the future vertical guidance performance of GPS user avionics sensor for the United States' WAAS, Japanese MTSAT-based satellite augmentation system (MSAS) and European geostationary navigation overlay service (EGNOS). PMID:22319263

  13. Space shuttle/payload interface analysis (study 2.4). Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    Pritchard, E. I.

    1973-01-01

    The space shuttle/payload interface analysis is presented. The analysis consists of the following sections: (1) payload capture and cost analysis, (2) business risk and value of operations in space analysis, and (3) payload community analysis. The primary objective of the study was to furnish a method for tracing capture/cost analyses conducted by other study groups.

  14. Space Shuttle photographic/television analysis project - An overview of image analysis techniques

    NASA Technical Reports Server (NTRS)

    Dailey, Christine L.; Rovinelli, Elizabeth R.; Pitts, David E.

    1992-01-01

    The Space Shuttle photographic and television analysis project (SSPTAP) at the Johnson Space Center (JSC) is described. The films and videos of every Space Shuttle launch and landing are scrutinized for information on the vehicle's condition and performance which can only be obtained by photographic means when necessary. On-orbit video is used to assess problems. The photographic information is used with various other data sources to develop feasible scenarios for particular events. The data and methods used to analyze the state of the Shuttle launch vehicle are analyzed, and examples are given of some of the studies that have been conducted.

  15. Preparation, purification, crystallization and preliminary crystallographic analysis of dual-domain β-propeller phytase from Bacillus sp. HJB17.

    PubMed

    Lu, Fang; Guo, Gangxin; Li, Qianqian; Feng, Duo; Liu, Yong; Huang, Huoqing; Yang, Peilong; Gao, Wei; Yao, Bin

    2014-12-01

    β-Propeller phytases (BPPs) are abundant in nature. Recently, dual-domain BPPs have been found in which the typical BPP domain is responsible for phytate hydrolysis. The dual-domain BPP (PhyH) from Bacillus sp. HJB17 was obtained with an incomplete N-terminal BPP domain (PhyH-DI; residues 41-318) and a typical BPP domain (PhyH-DII; residues 319-644) at the C-terminus. PhyH-DI was found to act synergistically (with a 1.2-2.5-fold increase in phosphate release) with PhyH-DII, other BPPs (PhyP and 168PhyA) and a histidine acid phosphatase. The structure of PhyH was therefore studied with the aim of explaining these functions. PhyH with the secreted signal peptide of the first 40 amino acids deleted (PhyHT) was cloned and expressed in Escherichia coli. Purified and active PhyHT protein was obtained by refolding from the precipitant. PhyHT was crystallized using the vapour-diffusion method. The crystal grew in a condition consisting of 0.2 M sodium acetate trihydrate, 0.1 M Tris-HCl pH 9.5, 25%(w/v) polyethylene glycol 4000 using 1 mg ml(-1) protein solution at 289 K. A complete data set was collected from a crystal to 2.85 Å resolution using synchrotron radiation at 100 K. The crystal belonged to space group P1211, with unit-cell parameters a = 46.82, b = 140.19, c = 81.94 Å, α = 90.00, β = 92.00, γ = 90.00°. The asymmetric unit was estimated to contain one molecule of PhyHT. PMID:25484224

  16. Interpretation of observed microwave signatures from ground dual polarization radar and space multi frequency radiometer for the 2011 Grímsvötn volcanic eruption

    NASA Astrophysics Data System (ADS)

    Montopoli, M.; Vulpiani, G.; Cimini, D.; Picciotti, E.; Marzano, F. S.

    2013-07-01

    The important role played by ground-based microwave weather radars for the monitoring of volcanic ash clouds has been recently demonstrated. The potential of microwaves from satellite passive and ground-based active sensors to estimate near-source volcanic ash cloud parameters has been also proposed, though with little investigation of their synergy and the role of the radar polarimetry. The goal of this work is to show the potentiality and drawbacks of the X-band Dual Polarization radar measurements (DPX) through the data acquired during the latest Grímsvötn volcanic eruptions that took place on May 2011 in Iceland. The analysis is enriched by the comparison between DPX data and the observations from the satellite Special Sensor Microwave Imager/Sounder (SSMIS) and a C-band Single Polarization (SPC) radar. SPC, DPX, and SSMIS instruments cover a large range of the microwaves spectrum, operating respectively at 5.4, 3.2, and 0.16-1.6 cm wavelengths. The multi-source comparison is made in terms of Total Columnar Concentration (TCC). The latter is estimated from radar observables using the "Volcanic Ash Radar Retrieval for dual-Polarization X band systems" (VARR-PX) algorithm and from SSMIS brightness temperature (BT) using a linear BT-TCC relationship. The BT-TCC relationship has been compared with the analogous relation derived from SSMIS and SPC radar data for the same case study. Differences between these two linear regression curves are mainly attributed to an incomplete observation of the vertical extension of the ash cloud, a coarser spatial resolution and a more pronounced non-uniform beam filling effect of SPC measurements (260 km far from the volcanic vent) with respect to the DPX (70 km from the volcanic vent). Results show that high-spatial-resolution DPX radar data identify an evident volcanic plume signature, even though the interpretation of the polarimetric variables and the related retrievals is not always straightforward, likely due to the

  17. Transcriptomic response of murine liver to severe injury and hemorrhagic shock: a dual-platform microarray analysis

    PubMed Central

    Edmonds, Rebecca D.; Lagoa, Claudio; Dutta-Moscato, Joyeeta; Yang, Yawching; Fink, Mitchell P.; Levy, Ryan M.; Prince, Jose M.; Kaczorowski, David J.; Tseng, George C.; Billiar, Timothy R.

    2011-01-01

    Trauma-hemorrhagic shock (HS/T) is a complex process that elicits numerous molecular pathways. We hypothesized that a dual-platform microarray analysis of the liver, an organ that integrates immunology and metabolism, would reveal key pathways engaged following HS/T. C57BL/6 mice were divided into five groups (n = 4/group), anesthetized, and surgically treated to simulate a time course and trauma severity model: 1) nonmanipulated animals, 2) minor trauma, 3) 1.5 h of hemorrhagic shock and severe trauma (HS/T), 4) 1.5 h HS/T followed by 1 h resuscitation (HS/T+1.0R), 5) 1.5 h HS/T followed by 4.5 h resuscitation (HS/T+4.5R). Liver RNA was hybridized to CodeLink and Affymetrix mouse whole genome microarray chips. Common genes with a cross-platform correlation >0.6 (2,353 genes in total) were clustered using k-means clustering, and clusters were analyzed using Ingenuity Pathways Analysis. Genes involved in the stress response and immunoregulation were upregulated early and remained upregulated throughout the course of the experiment. Genes involved in cell death and inflammatory pathways were upregulated in a linear fashion with elapsed time and in severe injury compared with minor trauma. Three of the six clusters contained genes involved in metabolic function; these were downregulated with elapsed time. Transcripts involved in amino acid metabolism as well as signaling pathways associated with glucocorticoid receptors, IL-6, IL-10, and the acute phase response were elevated in a severity-dependent manner. This is the first study to examine the postinjury response using dual-platform microarray analysis, revealing responses that may enable novel therapies or diagnostics. PMID:21828244

  18. Acetonitrile extraction and dual-layer solid phase extraction clean-up for pesticide residue analysis in propolis.

    PubMed

    Oellig, Claudia

    2016-05-01

    Propolis is a very complex mixture of substances that is produced by honey bees and is known to be a rather challenging matrix for residue analysis. Besides resins, flavonoids and phenols, high amount of wax is co-extracted resulting in immense matrix effects. Therefore a suitable clean-up is crucial and indispensable. In this study, a reliable solid phase extraction (SPE) clean-up was developed for pesticide residue analysis in propolis. The clean-up success was quickly and easily monitored by high-performance thin-layer chromatography with different detection possibilities. The final method consists of the extraction of propolis with acetonitrile according to the QuEChERS method followed by an effective extract purification on dual-layer SPE cartridges with spherical hydrophobic polystyrene-divinylbenzene resin/primary secondary amine as sorbent and a mixture of toluene/acetone (95:5, v/v) for elution. Besides fat-soluble components like waxes, flavonoids, and terpenoids, more polar compounds like organic acids, fatty acids, sugars and anthocyanins were also removed to large extent. Method performance was assessed by recovery experiments at spiking levels of 0.5 and 1mg/kg (n=5) for fourteen pesticides that are relevant for propolis. Mean recoveries determined by HPLC-MS against solvent standards were between 40 and 101%, while calculation against matrix-matched standards provided recoveries of 79-104%. Precision of recovery, assessed by relative standard deviations, were below 9%. Thus, the developed dual-layer SPE clean-up enables the reliable pesticide residue analysis in propolis and provides a suitable alternative to time-consuming clean-up procedures proposed in literature. PMID:27059398

  19. Dual matrix-based immobilized trypsin for complementary proteolytic digestion and fast proteomics analysis with higher protein sequence coverage.

    PubMed

    Fan, Chao; Shi, Zhaomei; Pan, Yiting; Song, Zifeng; Zhang, Wanjun; Zhao, Xinyuan; Tian, Fang; Peng, Bo; Qin, Weijie; Cai, Yun; Qian, Xiaohong

    2014-02-01

    In an age of whole-genome analysis, the mass spectrometry-based bottom-up strategy is now considered to be the most powerful method for in-depth proteomics analysis. As part of this strategy, highly efficient and complete proteolytic digestion of proteins into peptides is crucial for successful proteome profiling with deep coverage. To achieve this goal, prolonged digestion time and the use of multiple proteases have been adopted. The long digestion time required and tedious sample treatment steps severely limit the sample processing throughput. Though utilization of immobilized protease greatly reduces the digestion time, highly efficient proteolysis of extremely complex proteomic samples remains a challenging task. Here, we propose a dual matrix-based complementary digestion method using two types of immobilized trypsin with opposite matrix hydrophobicity prepared by attaching trypsin on hydrophobic or hydrophilic polymer-brush-modified nanoparticles. The polymer brushes on the nanoparticles serve as three-dimensional supports for a large amount of trypsin immobilization and lead to ultrafast and highly efficient protein digestion. More importantly, the two types of immobilized trypsin show high complementarity in protein digestion with only ∼60% overlap in peptide identification for yeast and membrane protein of mouse liver. Complementary digestion by applying these two types of immobilized trypsin together leads to obviously enhanced protein and peptide identification. Furthermore, the dual matrix-based complementary digestion shows particular advantage in the digestion of membrane proteins, as twice the number of identified peptides is obtained compared with solution digestion using free proteases, demonstrating its potential as a promising alternative to promote proteomics analysis with higher protein sequence coverage. PMID:24447065

  20. The Reconstruction and Failure Analysis of The Space Shuttle Columbia

    NASA Technical Reports Server (NTRS)

    Russell, Richard W.

    2010-01-01

    This viewgraph presentation describes a very detailed reconstruction plan and failure analysis of The Space Shuttle Columbia accident. The contents include: 1) STS-107 Timeline; 2) Foam Impact; 3) Recovery; 4) Reconstruction; 5) Reconstruction Plan; 6) Reconstruction Hanger; 7) Pathfinders; 8) Aluminum Pathfinder; 9) Early Analysis - Left MLG Door Area; 10) Emphasis Switched to Left Hand Wing Leading Edge; 11) Wing Leading Edge Subsystem (LESS); 12) 3D Reconstruction of Left WLE; 13) Left Wing Tile Table; 14) LESS Observations; 15) Left Hand Wing Debris Points to RCC 8/9 - Slumped Tile; 16) Reconstructed View of LC/P 9 tile with I/B Tile; 17) Reconstructed View of Lower C/P 9 Tile; 18) Carrier Panel 8 - Upper; 19) Left Hand Wing Debris Points to RCC 8/9 - Erosion and RCC with attach hole intact; 20) Erosion on Panel 8 Upper Outboard Rib; 21) RCC Panels 8 & 9 Erosion Features; 22) Slumping Source for Carrier Panel 9 Tile was Revealed; 23) Debris Indicated Highest Probability Initiation Site; 24) Left Hand Wing Debris Points to RCC 8/9- Metallic Deposits; 25) Relative Metallic Deposition on L/H Wing Materials; 26) Metallic Deposit Example, LH RCC 8; 27) High Level Questions; 28) Analysis Plan Challenges; 29) Analysis Techniques; 30) Analysis Approach; 31) RCC Panel 8 Erosion Features; 32) Radiographic Features; 33) Radiography WLE LH Panel 8; 34) LH RCC 8 Upper Apex; 35) LH RCC 8 - Deposit Feature: Thick Tear Shaped; 36) LH RCC 8 - Deposit Feature: Thick Globules; 37) LH RCC 8 - Deposit Feature: Spheroids; 38) LH RCC 8 - Deposit Feature: Uniform Deposit; 39) Significant Findings - Sampling All Other panels; 40) Proposed Breach Location and Plasma Flow; 41) Corroborating Information - RCC Panel Debris Locations; 42) Corroborating Information - LH OMS Pod Analysis; 43) Corroborating Information - Impact Testing; and 44) Overall Forensic Conclusions.

  1. Safety Analysis of the US Dual Coolant Liquid Lead-Lithium ITER Test Blanket Module

    SciTech Connect

    Merrill, Brad; Reyes, Susana; Sawan, Mohamed; Wong, Clement

    2006-07-01

    The US is proposing a prototype of a dual coolant liquid lead-lithium (DCLL) DEMO blanket concept for testing in the International Thermonuclear Experimental Reactor (ITER) as an ITER Test Blanket Module (TBM). Because safety considerations are an integral part of the design process to ensure that this TBM does not adversely impact the safety of ITER, a safety assessment has been conducted for this TBM and its ancillary systems as requested by the ITER project. Four events were selected by the ITER International Team (IT) to address specific reactor safety concerns, such as VV pressurization, confinement building pressure build-up, TBM decay heat removal capability, tritium and activation products release from the TBM system, and hydrogen and heat production from chemical reactions. This paper summarizes the results of this safety assessment conducted with the MELCOR computer code.

  2. Complexity analysis of dual-channel game model with different managers' business objectives

    NASA Astrophysics Data System (ADS)

    Li, Ting; Ma, Junhai

    2015-01-01

    This paper considers dual-channel game model with bounded rationality, using the theory of bifurcations of dynamical system. The business objectives of retailers are assumed to be different, which is closer to reality than previous studies. We study the local stable region of Nash equilibrium point and find that business objectives can expand the stable region and play an important role in price strategy. One interesting finding is that a fiercer competition tends to stabilize the Nash equilibrium. Simulation shows the complex behavior of two dimensional dynamic system, we find period doubling bifurcation and chaos phenomenon. We measure performances of the model in different period by using the index of average profit. The results show that unstable behavior in economic system is often an unfavorable outcome. So this paper discusses the application of adaptive adjustment mechanism when the model exhibits chaotic behavior and then allows the retailers to eliminate the negative effects.

  3. Innovative unmanned airship structural analysis: Dual-hull and exoskeletal configurations

    NASA Astrophysics Data System (ADS)

    Cappadona, A.; Lecca, R.; Vazzola, M.; Gili, P.; Farina, P.; Surace, C.

    2009-08-01

    The research study described concerns the design and development of an innovative airship concept which is remotely-controlled and intended to be used for monitoring, surveillance, exploration and reconnaissance missions. Two potential structural configurations have been analysed: the first consists of a dual-hull configuration, characterised by the presence of a primary support structure flanked by the two inflated sections held to the structure by appropriated bindings. The second is an exoskeletal configuration which features a single inflated section incorporating two separate elements held internally by a system of ribs. The final aim of this study is to analyse both configurations to determine the most appropriate solution in terms of performance and cost.

  4. Recent Development of Dual-Dictionary Learning Approach in Medical Image Analysis and Reconstruction

    PubMed Central

    Wang, Bigong; Li, Liang

    2015-01-01

    As an implementation of compressive sensing (CS), dual-dictionary learning (DDL) method provides an ideal access to restore signals of two related dictionaries and sparse representation. It has been proven that this method performs well in medical image reconstruction with highly undersampled data, especially for multimodality imaging like CT-MRI hybrid reconstruction. Because of its outstanding strength, short signal acquisition time, and low radiation dose, DDL has allured a broad interest in both academic and industrial fields. Here in this review article, we summarize DDL's development history, conclude the latest advance, and also discuss its role in the future directions and potential applications in medical imaging. Meanwhile, this paper points out that DDL is still in the initial stage, and it is necessary to make further studies to improve this method, especially in dictionary training. PMID:26089956

  5. Dual stator winding variable speed asynchronous generator: magnetic equivalent circuit with saturation, FEM analysis and experiments

    NASA Astrophysics Data System (ADS)

    Tutelea, L. N.; Muntean, N.; Deaconu, S. I.; Cunţan, C. D.

    2016-02-01

    The authors carried out a theoretical and experimental study of dual stator winding squirrel cage asynchronous generator (DSWA) behaviour in the presence of saturation regime (non-sinusoidal) due to the variable speed operation. The main aims are the determination of the relations of calculating the equivalent parameters of the machine windings, FEM validation of parameters and characteristics with free FEMM 4.2 computing software and the practice experimental tests for verifying them. Issue is limited to three phase range of double stator winding cage-asynchronous generator of small sized powers, the most currently used in the small adjustable speed wind or hydro power plants. The tests were carried out using three-phase asynchronous generator having rated power of 6 [kVA].

  6. Varied absorption peaks of dual-band metamaterial absorber analysis by using reflection theory

    NASA Astrophysics Data System (ADS)

    Xiong, Han; Yu, Yan-Tao; Tang, Ming-Chun; Chen, Shi-Yong; Liu, Dan-Ping; Ou, Xiang; Zeng, Hao

    2016-03-01

    Cross-resonator metamaterial absorbers (MMA) have been widely investigated from microwave to optical frequencies. However, only part of the factors influencing the absorption properties were analyzed in previous works at the same time. In order to completely understand how the spacer thickness, dielectric parameter and incidence angle affect the absorption properties of the dual-band MMA, two sets of simulation were performed. It was found that with increasing incident angles, the low-frequency absorption peak showed a blue shift, while the high-frequency absorption peaks showed a red shift. However, with the increase in spacer thickness, both of the absorption peaks showed a red shift. By using the reflection theory expressions, the physical mechanism of the cross-resonator MMA was well explained. This method provides an effective way to analyze multi-band absorber in technology.

  7. Analysis of dual-task elderly gait in fallers and non-fallers using wearable sensors.

    PubMed

    Howcroft, Jennifer; Kofman, Jonathan; Lemaire, Edward D; McIlroy, William E

    2016-05-01

    Dual-task (DT) gait involves walking while simultaneously performing an attention-demanding task and can be used to identify impaired gait or executive function in older adults. Advancment is needed in techniques that quantify the influence of dual tasking to improve predictive and diagnostic potential. This study investigated the viability of wearable sensor measures to identify DT gait changes in older adults and distinguish between elderly fallers and non-fallers. A convenience sample of 100 older individuals (75.5±6.7 years; 76 non-fallers, 24 fallers based on 6 month retrospective fall occurrence) walked 7.62m under single-task (ST) and DT conditions while wearing pressure-sensing insoles and tri-axial accelerometers at the head, pelvis, and left and right shanks. Differences between ST and DT gait were identified for temporal measures, acceleration descriptive statistics, Fast Fourier Transform (FFT) quartiles, ratio of even to odd harmonics, center of pressure (CoP) stance path coefficient of variation, and deviations to expected CoP stance path. Increased posterior CoP stance path deviations, increased coefficient of variation, decreased FFT quartiles, and decreased ratio of even to odd harmonics suggested increased DT gait variability. Decreased gait velocity and decreased acceleration standard deviations (SD) at the pelvis and shanks could represent compensatory gait strategies that maintain stability. Differences in acceleration between fallers and non-fallers in head posterior SD and pelvis AP ratio of even to odd harmonics during ST, and pelvis vertical maximum Lyapunov exponent during DT gait were identified. Wearable-sensor-based DT gait assessments could be used in point-of-care environments to identify gait deficits. PMID:26994786

  8. Selected tether applications in space: An analysis of five selected concepts

    NASA Astrophysics Data System (ADS)

    1984-07-01

    Ground rules and assumptions; operations; orbit considerations/dynamics; tether system design and dynamics; functional requirements; hardware concepts; and safety factors are examined for five scenarios: tethered effected separation of an Earth bound shuttle from the space station; tether effected orbit boost of a spacecraft (AXAF) into its operational orbit from the shuttle; an operational science/technology platform tether deployed from space station; a tether mediated rendezvous involving an OMV tether deployed from space station to rendezvous with an aerobraked OTV returning to geosynchronous orbit from a payload delivery mission; and an electrodynamic tether used in a dual motor/generator mode to serve as the primary energy storage facility for space station.

  9. Selected tether applications in space: An analysis of five selected concepts

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Ground rules and assumptions; operations; orbit considerations/dynamics; tether system design and dynamics; functional requirements; hardware concepts; and safety factors are examined for five scenarios: tethered effected separation of an Earth bound shuttle from the space station; tether effected orbit boost of a spacecraft (AXAF) into its operational orbit from the shuttle; an operational science/technology platform tether deployed from space station; a tether mediated rendezvous involving an OMV tether deployed from space station to rendezvous with an aerobraked OTV returning to geosynchronous orbit from a payload delivery mission; and an electrodynamic tether used in a dual motor/generator mode to serve as the primary energy storage facility for space station.

  10. Space station needs, attributes and architectural options study. Volume 2: Mission analysis

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Space environment studies, astrophysics, Earth environment, life sciences, and material sciences are discussed. Commercial communication, materials processing, and Earth observation missions are addressed. Technology development, space operations, scenarios of operational capability, mission requirements, and benefits analysis results for space-produced gallium arsenide crystals, direct broadcasting satellite systems, and a high inclination space station are covered.

  11. Directed synthesis of noncentrosymmetric molybdates using composition space analysis.

    PubMed

    Veltman, Thomas R; Stover, Adam K; Narducci Sarjeant, Amy; Ok, Kang Min; Halasyamani, P Shiv; Norquist, Alexander J

    2006-07-10

    A systematic investigation of the factors governing the reaction product composition, hydrogen bonding, and symmetry was conducted in the MoO3/3-aminoquinuclidine/H2O system. Composition space analysis was performed through 36 individual reactions under mild hydrothermal conditions using racemic 3-aminoquinuclidine. Single crystals of three new compounds, [C7H16N2][Mo3O10] x H2O, [C7H16N2]2[Mo8O26] x H2O, and [C7H16N2]2[Mo8O26] x 4 H2O, were grown. The relative phase stabilities for these products are dependent upon the reactant mole fractions in the initial reaction gel. This phase stability information was used to direct the synthesis of two new noncentrosymmetric compounds, using either (S)-(-)-3-aminoquinuclidine dihydrochloride or (R)-(+)-3-aminoquinuclidine dihydrochloride. [(R)-C7H16N2]2[Mo8O26] and [(S)-C7H16N2]2[Mo8O26] both crystallize in the noncentrosymmetric space group P2(1) (No. 4), which has the polar crystal class 2 (C2). The second-harmonic generation activities were measured on sieved powders. The structure-directing properties of the molybdate components in each compound were determined using bond valence sums. The structures of all five compounds were determined using single-crystal X-ray diffraction. PMID:16813416

  12. Unified Simulation and Analysis Framework for Deep Space Navigation Design

    NASA Technical Reports Server (NTRS)

    Anzalone, Evan; Chuang, Jason; Olsen, Carrie

    2013-01-01

    As the technology that enables advanced deep space autonomous navigation continues to develop and the requirements for such capability continues to grow, there is a clear need for a modular expandable simulation framework. This tool's purpose is to address multiple measurement and information sources in order to capture system capability. This is needed to analyze the capability of competing navigation systems as well as to develop system requirements, in order to determine its effect on the sizing of the integrated vehicle. The development for such a framework is built upon Model-Based Systems Engineering techniques to capture the architecture of the navigation system and possible state measurements and observations to feed into the simulation implementation structure. These models also allow a common environment for the capture of an increasingly complex operational architecture, involving multiple spacecraft, ground stations, and communication networks. In order to address these architectural developments, a framework of agent-based modules is implemented to capture the independent operations of individual spacecraft as well as the network interactions amongst spacecraft. This paper describes the development of this framework, and the modeling processes used to capture a deep space navigation system. Additionally, a sample implementation describing a concept of network-based navigation utilizing digitally transmitted data packets is described in detail. This developed package shows the capability of the modeling framework, including its modularity, analysis capabilities, and its unification back to the overall system requirements and definition.

  13. Geometrically Nonlinear Finite Element Analysis of a Composite Space Reflector

    NASA Technical Reports Server (NTRS)

    Lee, Kee-Joo; Leet, Sung W.; Clark, Greg; Broduer, Steve (Technical Monitor)

    2001-01-01

    Lightweight aerospace structures, such as low areal density composite space reflectors, are highly flexible and may undergo large deflection under applied loading, especially during the launch phase. Accordingly, geometrically nonlinear analysis that takes into account the effect of finite rotation may be needed to determine the deformed shape for a clearance check and the stress and strain state to ensure structural integrity. In this study, deformation of the space reflector is determined under static conditions using a geometrically nonlinear solid shell finite element model. For the solid shell element formulation, the kinematics of deformation is described by six variables that are purely vector components. Because rotational angles are not used, this approach is free of the limitations of small angle increments. This also allows easy connections between substructures and large load increments with respect to the conventional shell formulation using rotational parameters. Geometrically nonlinear analyses were carried out for three cases of static point loads applied at selected points. A chart shows results for a case when the load is applied at the center point of the reflector dish. The computed results capture the nonlinear behavior of the composite reflector as the applied load increases. Also, they are in good agreement with the data obtained by experiments.

  14. Space Shuttle Main Engine real time stability analysis

    NASA Astrophysics Data System (ADS)

    Kuo, F. Y.

    1993-06-01

    The Space Shuttle Main Engine (SSME) is a reusable, high performance, liquid rocket engine with variable thrust. The engine control system continuously monitors the engine parameters and issues propellant valve control signals in accordance with the thrust and mixture ratio commands. A real time engine simulation lab was installed at MSFC to verify flight software and to perform engine dynamic analysis. A real time engine model was developed on the AD100 computer system. This model provides sufficient fidelity on the dynamics of major engine components and yet simplified enough to be executed in real time. The hardware-in-the-loop type simulation and analysis becomes necessary as NASA is continuously improving the SSME technology, some with significant changes in the dynamics of the engine. The many issues of interfaces between new components and the engine can be better understood and be resolved prior to the firing of the engine. In this paper, the SSME real time simulation Lab at the MSFC, the SSME real time model, SSME engine and control system stability analysis, both in real time and non-real time is presented.

  15. Random vibration analysis of space flight hardware using NASTRAN

    NASA Technical Reports Server (NTRS)

    Thampi, S. K.; Vidyasagar, S. N.

    1990-01-01

    During liftoff and ascent flight phases, the Space Transportation System (STS) and payloads are exposed to the random acoustic environment produced by engine exhaust plumes and aerodynamic disturbances. The analysis of payloads for randomly fluctuating loads is usually carried out using the Miles' relationship. This approximation technique computes an equivalent load factor as a function of the natural frequency of the structure, the power spectral density of the excitation, and the magnification factor at resonance. Due to the assumptions inherent in Miles' equation, random load factors are often over-estimated by this approach. In such cases, the estimates can be refined using alternate techniques such as time domain simulations or frequency domain spectral analysis. Described here is the use of NASTRAN to compute more realistic random load factors through spectral analysis. The procedure is illustrated using Spacelab Life Sciences (SLS-1) payloads and certain unique features of this problem are described. The solutions are compared with Miles' results in order to establish trends at over or under prediction.

  16. The Necessity of Functional Analysis for Space Exploration Programs

    NASA Technical Reports Server (NTRS)

    Morris, A. Terry; Breidenthal, Julian C.

    2011-01-01

    As NASA moves toward expanded commercial spaceflight within its human exploration capability, there is increased emphasis on how to allocate responsibilities between government and commercial organizations to achieve coordinated program objectives. The practice of program-level functional analysis offers an opportunity for improved understanding of collaborative functions among heterogeneous partners. Functional analysis is contrasted with the physical analysis more commonly done at the program level, and is shown to provide theoretical performance, risk, and safety advantages beneficial to a government-commercial partnership. Performance advantages include faster convergence to acceptable system solutions; discovery of superior solutions with higher commonality, greater simplicity and greater parallelism by substituting functional for physical redundancy to achieve robustness and safety goals; and greater organizational cohesion around program objectives. Risk advantages include avoidance of rework by revelation of some kinds of architectural and contractual mismatches before systems are specified, designed, constructed, or integrated; avoidance of cost and schedule growth by more complete and precise specifications of cost and schedule estimates; and higher likelihood of successful integration on the first try. Safety advantages include effective delineation of must-work and must-not-work functions for integrated hazard analysis, the ability to formally demonstrate completeness of safety analyses, and provably correct logic for certification of flight readiness. The key mechanism for realizing these benefits is the development of an inter-functional architecture at the program level, which reveals relationships between top-level system requirements that would otherwise be invisible using only a physical architecture. This paper describes the advantages and pitfalls of functional analysis as a means of coordinating the actions of large heterogeneous organizations

  17. Software Construction and Analysis Tools for Future Space Missions

    NASA Technical Reports Server (NTRS)

    Lowry, Michael R.; Clancy, Daniel (Technical Monitor)

    2002-01-01

    NASA and its international partners will increasingly depend on software-based systems to implement advanced functions for future space missions, such as Martian rovers that autonomously navigate long distances exploring geographic features formed by surface water early in the planet's history. The software-based functions for these missions will need to be robust and highly reliable, raising significant challenges in the context of recent Mars mission failures attributed to software faults. After reviewing these challenges, this paper describes tools that have been developed at NASA Ames that could contribute to meeting these challenges; 1) Program synthesis tools based on automated inference that generate documentation for manual review and annotations for automated certification. 2) Model-checking tools for concurrent object-oriented software that achieve memorability through synergy with program abstraction and static analysis tools.

  18. Space Telecommunications Radio System (STRS) Application Repository Design and Analysis

    NASA Technical Reports Server (NTRS)

    Handler, Louis M.

    2013-01-01

    The Space Telecommunications Radio System (STRS) Application Repository Design and Analysis document describes the STRS application repository for software-defined radio (SDR) applications intended to be compliant to the STRS Architecture Standard. The document provides information about the submission of artifacts to the STRS application repository, to provide information to the potential users of that information, and for the systems engineer to understand the requirements, concepts, and approach to the STRS application repository. The STRS application repository is intended to capture knowledge, documents, and other artifacts for each waveform application or other application outside of its project so that when the project ends, the knowledge is retained. The document describes the transmission of technology from mission to mission capturing lessons learned that are used for continuous improvement across projects and supporting NASA Procedural Requirements (NPRs) for performing software engineering projects and NASAs release process.

  19. Feature space discriminant analysis for hyperspectral data feature reduction

    NASA Astrophysics Data System (ADS)

    Imani, Maryam; Ghassemian, Hassan

    2015-04-01

    Hyperspectral images contain a large number of spectral bands that allows us to distinguish different classes with more details. But, the number of available training samples is limited. Thus, feature reduction is an important step before classification of high dimensional data. Supervised feature extraction methods such as LDA, GDA, NWFE, and MMLDA use two criteria for feature reduction: between-class scatter and within-class scatter. We propose a supervised feature extraction method in this paper that uses a new criterion in addition to two mentioned measures. The proposed method, which is called feature space discriminant analysis (FSDA), at first, maximizes the between-spectral scatter matrix to increase the difference between extracted features. In the second step, FSDA, maximizes the between-class scatter matrix and minimizes the within-class scatter matrix simultaneously. The experimental results on five popular hyperspectral images show the better performance of FSDA in comparison with other supervised feature extraction methods in small sample size situation.

  20. Development of the free-space optical communications analysis software

    NASA Astrophysics Data System (ADS)

    Jeganathan, Muthu; Mecherle, G. Stephen; Lesh, James R.

    1998-05-01

    The Free-space Optical Communication Analysis Software (FOCAS) was developed at the Jet Propulsion Laboratory (JPL) to provide mission planners, systems engineers and communications engineers with an easy to use tool to analyze direct-detection optical communication links. The FOCAS program, implemented in Microsoft Excel, gives it all the power and flexibility built into the spreadsheet. An easy-to-use interface, developed using Visual Basic for Applications (VBA), to the spreadsheet allows easy input of data and parameters. A host of pre- defined components allow an analyst to configure a link without having to know the details of the components. FOCAS replaces the over-a-decade-old FORTRAN program called OPTI widely used previously at JPL. This paper describes the features and capabilities of the Excel-spreadsheet-based FOCAS program.

  1. Systems analysis of solid fuel nuclear engines in cislunar space

    NASA Astrophysics Data System (ADS)

    Thomas, U.; Koelle, H. H.; Balzer-Sieb, R.; Bernau, D.; Czarnitzki, J.; Floete, A.; Goericke, D.; Lindenthal, A.; Protsch, R.; Teschner, O.

    1984-12-01

    The use of nuclear engines in cislunar space was studied and the restrictions imposed on nuclear ferries by the chemical Earth to lower Earth orbit (LEO) transportation system were analyzed. The operating conditions are best met by tungsten-water-moderated reactors due to a high specific impulse and long durability. Specific transportation cost for LEO to geostationary orbit (GEO) and LEO to lunar orbit flights were calculated for a transportation system life of 50 yr. Average transportation costs are estimated to be 141 $/kg. No difference is made for both routes. An additional analysis of smaller and larger flight units shows only small cost reductions by employing larger ferries but a significant cost increase in case smaller flight units are used.

  2. Experimental analysis of a joint free space cryptosystem

    NASA Astrophysics Data System (ADS)

    Ramírez, John Fredy Barrera; Osorio, Alexis Jaramillo; Zea, Alejandro Vélez; Torroba, Roberto

    2016-08-01

    In this paper, we analyze a joint free space cryptosystem scheme implemented in an actual laboratory environment. In this encrypting architecture, the object to be encoded and the security key are placed side by side in the input plane without optical elements between the input and the output planes. In order to get the encrypted information, the joint Fresnel power distribution JFPD coming from the input plane is registered in a CMOS camera. The information of the encrypting key is registered with an off axis Fresnel holographic setup. The data registered with the experimental setup is digitally filtered to obtain the encrypted object and the encryption key. In addition, we explore the performance of the experimental system as a function of the object-camera and key-camera distances, which are two new parameters of interest. These parameters become available as a result of developing this encrypting scheme. The theoretical and experimental analysis shows the validity and applicability of the cryptosystem.

  3. Transmission-corrected x-ray fluorescence analysis of uranium and plutonium solutions using a dual transmission source

    SciTech Connect

    Ruhter, W.D.; Camp, D.C.

    1987-11-24

    The energy-dispersive x-ray fluorescence analysis (XRFA) technique has been implemented at several spent nuclear fuel reprocessing facilities for nondestructive measurements of uranium and/or plutonium concentrations in process streams and product storage tanks. An important factor in these quantitative measurements is the absorption of the fluoresced x-rays by the solution matrix, which must be taken into account to accurately quantify the U or Pu concentrations. We describe a new, accurate method using a dual transmission source of Gd-153 and Co-57 to correct for matrix effects. Results of measurements on uranium and plutonium solution standards show the methodology to be better than 0.5%, which includes statistical precision, over the concentration range from 1 to 250 g/l. 5 refs., 4 figs., 3 tabs.

  4. Design of Dual band Modified Inverted F-Antenna for Military and Intelligent Transportation System (ITS) Applications by Numerical Analysis

    NASA Astrophysics Data System (ADS)

    Hossain, Robiul; Karmokar, Debabrata Kumar

    2012-11-01

    A design of single feed Dual Band Modified Inverted F-Antenna (IFA) operating at 4.45 GHz (4.4-4.7GHz) and 5.9 GHz (5.850-5.925 GHz) has been proposed in this paper. The design is initiated by trial and error method of Numerical Analysis and method of moments (MoMís) in Numerical Electromagnetic code (NEC) is used to design, simulate and analyze this antenna. The results exhibit a proper operation of the antenna in terms of return loss, bandwidth, efficiency, VSWR, and gain at both bands. Proposed antenna is designed to achieve multi-serving purposes. Military applications and applications in the Intelligent Transportation Systems (ITS) are the most important applications within the above mentioned frequency bands respectively. The simulated results including performance parameters of antenna are presented and all are acceptable for the standard antennas.

  5. An analysis of short pulse and dual frequency radar techniques for measuring ocean wave spectra from satellites

    NASA Technical Reports Server (NTRS)

    Jackson, F. C.

    1980-01-01

    Scanning beam microwave radars were used to measure ocean wave directional spectra from satellites. In principle, surface wave spectral resolution in wave number can be obtained using either short pulse (SP) or dual frequency (DF) techniques; in either case, directional resolution obtains naturally as a consequence of a Bragg-like wave front matching. A four frequency moment characterization of backscatter from the near vertical using physical optics in the high frequency limit was applied to an analysis of the SP and DF measurement techniques. The intrinsic electromagnetic modulation spectrum was to the first order in wave steepness proportional to the large wave directional slope spectrum. Harmonic distortion was small and was a minimum near 10 deg incidence. NonGaussian wave statistics can have an effect comparable to that in the second order of scattering from a normally distributed sea surface. The SP technique is superior to the DF technique in terms of measurement signal to noise ratio and contrast ratio.

  6. Analysis of dual-end-pumped Nd3+-doped index-crossover gain guided-index antiguided fiber laser

    NASA Astrophysics Data System (ADS)

    Shen, Xiao; Wei, Wei; Zou, Hui; Zhang, Liaolin

    2016-05-01

    A dual-end pumped Nd3+-doped index-crossover gain guided-index antiguided (IGG-IAG) fiber laser is analyzed in theory. Pump light propagation and output laser characteristics are both explored by solving the related rate equations. Simulation results show that pump power confined in the IGG-IAG fiber core is larger and more uniform than that of the gain-guided and index-antiguided(GG-IAG) fiber, and the optimum fiber length and the output power of the IGG-IAG fiber laser are both larger than that of GG-IAG fiber laser. The relationship between threshold pump power and doped concentration, fiber length, fiber radius is researched respectively. The analysis results give out a method for the optimal design of the IGG-IAG fiber laser.

  7. Analysis and Design Considerations of a High-Power Density, Dual Air Gap, Axial-Field Brushless, Permanent Magnet Motor.

    NASA Astrophysics Data System (ADS)

    Cho, Chahee Peter

    1995-01-01

    Until recently, brush dc motors have been the dominant drive system because they provide easily controlled motor speed over a wide range, rapid acceleration and deceleration, convenient control of position, and lower product cost. Despite these capabilities, the brush dc motor configuration does not satisfy the design requirements for the U.S. Navy's underwater propulsion applications. Technical advances in rare-earth permanent magnet materials, in high-power semiconductor transistor technology, and in various rotor position-sensing devices have made using brushless permanent magnet motors a viable alternative. This research investigates brushless permanent magnet motor technology, studying the merits of dual-air gap, axial -field, brushless, permanent magnet motor configuration in terms of power density, efficiency, and noise/vibration levels. Because the design objectives for underwater motor applications include high-power density, high-performance, and low-noise/vibration, the traditional, simplified equivalent circuit analysis methods to assist in meeting these goals were inadequate. This study presents the development and verification of detailed finite element analysis (FEA) models and lumped parameter circuit models that can calculate back electromotive force waveforms, inductance, cogging torque, energized torque, and eddy current power losses. It is the first thorough quantification of dual air-gap, axial -field, brushless, permanent magnet motor parameters and performance characteristics. The new methodology introduced in this research not only facilitates the design process of an axial field, brushless, permanent magnet motor but reinforces the idea that the high-power density, high-efficiency, and low-noise/vibration motor is attainable.

  8. Closely Spaced MEG Source Localization and Functional Connectivity Analysis Using a New Prewhitening Invariance of Noise Space Algorithm

    PubMed Central

    Zhang, Junpeng; Cui, Yuan; Deng, Lihua; He, Ling; Zhang, Junran; Zhang, Jing; Zhou, Qun; Liu, Qi; Zhang, Zhiguo

    2016-01-01

    This paper proposed a prewhitening invariance of noise space (PW-INN) as a new magnetoencephalography (MEG) source analysis method, which is particularly suitable for localizing closely spaced and highly correlated cortical sources under real MEG noise. Conventional source localization methods, such as sLORETA and beamformer, cannot distinguish closely spaced cortical sources, especially under strong intersource correlation. Our previous work proposed an invariance of noise space (INN) method to resolve closely spaced sources, but its performance is seriously degraded under correlated noise between MEG sensors. The proposed PW-INN method largely mitigates the adverse influence of correlated MEG noise by projecting MEG data to a new space defined by the orthogonal complement of dominant eigenvectors of correlated MEG noise. Simulation results showed that PW-INN is superior to INN, sLORETA, and beamformer in terms of localization accuracy for closely spaced and highly correlated sources. Lastly, source connectivity between closely spaced sources can be satisfactorily constructed from source time courses estimated by PW-INN but not from results of other conventional methods. Therefore, the proposed PW-INN method is a promising MEG source analysis to provide a high spatial-temporal characterization of cortical activity and connectivity, which is crucial for basic and clinical research of neural plasticity. PMID:26819768

  9. Average bit error rate performance analysis of subcarrier intensity modulated MRC and EGC FSO systems with dual branches over M distribution turbulence channels

    NASA Astrophysics Data System (ADS)

    Wang, Ran-ran; Wang, Ping; Cao, Tian; Guo, Li-xin; Yang, Yintang

    2015-07-01

    Based on the space diversity reception, the binary phase-shift keying (BPSK) modulated free space optical (FSO) system over Málaga (M) fading channels is investigated in detail. Under independently and identically distributed and independently and non-identically distributed dual branches, the analytical average bit error rate (ABER) expressions in terms of H-Fox function for maximal ratio combining (MRC) and equal gain combining (EGC) diversity techniques are derived, respectively, by transforming the modified Bessel function of the second kind into the integral form of Meijer G-function. Monte Carlo (MC) simulation is also provided to verify the accuracy of the presented models.

  10. Discrete-Trial Functional Analysis of Problem Behavior and Functional Communication Training in Three Adults with a Dual Diagnosis of a Significant Intellectual Disability and a Mental Illness

    ERIC Educational Resources Information Center

    Chezan, Laura Claudia

    2012-01-01

    I conducted two studies. First, I examined the applicability of discrete-trial functional analysis (DTFA) for identifying the function of problem behavior in three adults with a dual diagnosis of a significant intellectual disability and a mental illness. Results indicated clear patterns of problem behavior for each participant. Second, I used a…

  11. An Integrated Microfabricated Device for Dual Microdialysis and On-line ESI Ion Trap Mass Spectrometry for the Analysis of Complex Biological Samples

    SciTech Connect

    Xiang, Fan; Lin, Yuehe ); Wen, Jian Y.; Matson, Dean W. ); Smith, Richard D. )

    1999-05-01

    A microfabricated dual-microdialysis device in a single integrated microfabricated platform was constructed using laser micromachining techniques for the rapid fractionation and cleanup of complex biological samples. Results suggest the potential for integration of such microfabricated devices with other sample manipulations for the rapid ESI-MS analysis of complex biological samples.

  12. Sensor space group analysis for fNIRS data

    PubMed Central

    Tak, S.; Uga, M.; Flandin, G.; Dan, I.; Penny, W.D.

    2016-01-01

    Background Functional near-infrared spectroscopy (fNIRS) is a method for monitoring hemoglobin responses using optical probes placed on the scalp. fNIRS spatial resolution is limited by the distance between channels defined as a pair of source and detector, and channel positions are often inconsistent across subjects. These challenges can lead to less accurate estimate of group level effects from channel-specific measurements. New method This paper addresses this shortcoming by applying random-effects analysis using summary statistics to interpolated fNIRS topographic images. Specifically, we generate individual contrast images containing the experimental effects of interest in a canonical scalp surface. Random-effects analysis then allows for making inference about the regionally specific effects induced by (potentially) multiple experimental factors in a population. Results We illustrate the approach using experimental data acquired during a colour-word matching Stroop task, and show that left frontopolar regions are significantly activated in a population during Stroop effects. This result agrees with previous neuroimaging findings. Compared with existing methods The proposed methods (i) address potential misalignment of sensor locations between subjects using spatial interpolation; (ii) produce experimental effects of interest either on a 2D regular grid or on a 3D triangular mesh, both representations of a canonical scalp surface; and (iii) enables one to infer population effects from fNIRS data using a computationally efficient summary statistic approach (random-effects analysis). Significance of regional effects is assessed using random field theory. Conclusions In this paper, we have shown how fNIRS data from multiple subjects can be analysed in sensor space using random-effects analysis. PMID:26952847

  13. A Single In-Vial Dual Extraction Strategy for the Simultaneous Lipidomics and Proteomics Analysis of HDL and LDL Fractions.

    PubMed

    Godzien, Joanna; Ciborowski, Michal; Armitage, Emily Grace; Jorge, Inmaculada; Camafeita, Emilio; Burillo, Elena; Martín-Ventura, Jose Luis; Rupérez, Francisco J; Vázquez, Jesús; Barbas, Coral

    2016-06-01

    A single in-vial dual extraction (IVDE) procedure for the subsequent analysis of lipids and proteins in the high-density lipoprotein (HDL) and low-density lipoprotein (LDL) fractions derived from the same biological sample is presented. On the basis of methyl-tert-butyl ether (MTBE) extraction, IVDE leads to the formation of three phases: a protein pellet at the bottom, an aqueous phase with polar compounds, and an ether phase with lipophilic compounds. After sample extraction, performed within a high-performance liquid chromatography vial insert, the ether phase was directly injected for lipid fingerprinting, while the protein pellet, after evaporation of the remaining sample, was used for proteomics analysis. Human HDL and LDL isolates were used to test the suitability of the IVDE methodology for lipid and protein analysis from a single sample in terms of data quality and matching composition to that of HDL and LDL. Subsequently, HDL and LDL fractions isolated from ApoE-KO and wild-type mice were used to validate the capacity of IVDE for revealing changes in lipid and protein abundance. Results indicate that IVDE can be successfully used for the subsequent analysis of lipids and proteins with the advantages of time saving, simplicity, and reduced sample amount. PMID:27117984

  14. Network Analysis of a Comprehensive Knowledge Repository Reveals a Dual Role for Ceramide in Alzheimer’s Disease

    PubMed Central

    Mizuno, Satoshi; Ogishima, Soichi; Kitatani, Kazuyuki; Kikuchi, Masataka; Tanaka, Hiroshi; Yaegashi, Nobuo; Nakaya, Jun

    2016-01-01

    Alzheimer’s disease (AD) is the most common cause of senile dementia. Many inflammatory factors such as amyloid-β and pro-inflammatory cytokines are known to contribute to the inflammatory response in the AD brain. Sphingolipids are widely known to have roles in the pathogenesis of inflammatory diseases, where the precise roles for sphingolipids in inflammation-associated pathogenesis of AD are not well understood. Here we performed a network analysis to clarify the importance of sphingolipids and to model relationships among inflammatory factors and sphingolipids in AD. In this study, we have updated sphingolipid signaling and metabolic cascades in a map of AD signaling networks that we named “AlzPathway,” a comprehensive knowledge repository of signaling pathways in AD. Our network analysis of the updated AlzPathway indicates that the pathways related to ceramide are one of the primary pathways and that ceramide is one of the important players in the pathogenesis of AD. The results of our analysis suggest the following two prospects about inflammation in AD: (1) ceramide could play important roles in both inflammatory and anti-inflammatory pathways of AD, and (2) several factors such as Sphingomyelinase and Siglec-11 may be associated with ceramide related inflammation and anti-inflammation pathways in AD. In this study, network analysis of comprehensive knowledge repository reveals a dual role for ceramide in AD. This result provides a clue to clarify sphingolipids related inflammatory and anti-inflammatory pathways in AD. PMID:26849355

  15. [High throuput analysis of organophosphorus pesticide residues and their metabolites in animal original foods by dual gas chromatography-dual pulse flame photometric detection].

    PubMed

    Yang, Lixin; Li, Heli; Miao, Hong; Zeng, Fangang; Li, Ruifeng; Chen, Huijing; Zhao, Yunfeng; Wu, Yongning

    2011-10-01

    A method was established for the quantitative determination of 54 organophosphorus pesticide residues and their metabolites in foods of animal origin by dual gas chromatography-dual pulse flame photometric detection. Homogenized samples were extracted with acetone and methylene chloride, and cleaned-up by gel permeation chromatography (GPC). The response of each analyte showed a good linearity with a correlation coefficient not less than 0. 99. The recovery experiments were performed by a blank sample spiked at low, medium and high fortification levels. The recoveries for beef, mutton, pork, chicken were in the range of 50. 5% -128. 1% with the relative standard deviations (n = 6) of 1. 1% -25. 5%, which demonstrated the good precision and accuracy of the present method. The limits of detection for the analytes were in the range of 0. 001 -0. 170 mg/kg, and the limits of quantification were in the range of 0. 002 -0. 455 mg/kg. Animal food samples collected from markets such as meat, liver and kidney were analyzed, and the residues of dichlorovos and disulfoton-sulfoxide were found in the some samples. The established method is sensitive and selective enough to detect organophosphorus pesticide residues in animal foods. PMID:22268359

  16. Space transfer concepts and analysis for exploration missions

    NASA Technical Reports Server (NTRS)

    1991-01-01

    A broad scoped and systematic study was made of space transfer concepts for human Lunar and Mars missions. Relevant space transportation studies were initiated to lead to further detailed activities in the following study period.

  17. Global Precipitation Measurement - Report 9 Core Coverage Trade Space Analysis

    NASA Technical Reports Server (NTRS)

    Mailhe, Laurie; Schiff, Conrad; Mendelsohn, Chad; Everett, David; Folta, David

    2002-01-01

    This paper summarizes the GPM-Core coverage trade space analysis. The goal of this analysis was to determine the GPM-Core sensitivity to changes in altitude and inclination for the three onboard instruments: the radiometer, the KU band radar and the KA band radar. This study will enable a better choice of the nominal GPM-Core orbit as well as the optimal size of the maintenance box (+/-1 km, +/-5 km..). For this work, we used two different figures-of-merit: (1) the time required to cover 100% of the +/-65 deg latitude band and (2) the coverage obtained for a given propagation time (7 days and 30 days). The first figure-of-merit is used for the radiometer as it has a sensor cone half-angle between 3 to 5 times bigger than the radars. Thus, we anticipate that for this instrument the period of the orbit (i.e. altitude) will be the main driver and that the 100% coverage value will be reached within less than a week. The second figure-of-merit is used for the radar instruments as they have small sensor cone half-angle and will, in some cases, never reach the 100% coverage threshold point.

  18. Signal Adaptive System for Space/Spatial-Frequency Analysis

    NASA Astrophysics Data System (ADS)

    Ivanović, Veselin N.; Jovanovski, Srdjan

    2010-12-01

    This paper outlines the development of a multiple-clock-cycle implementation (MCI) of a signal adaptive two-dimensional (2D) system for space/spatial-frequency (S/SF) signal analysis. The design is based on a method for improved S/SF representation of the analyzed 2D signals, also proposed here. The proposed MCI design optimizes critical design performances related to hardware complexity, making it a suitable system for real time implementation on an integrated chip. Additionally, the design allows the implemented system to take a variable number of clock cycles (CLKs) (the only necessary ones regarding desirable—2D Wigner distribution-presentation of autoterms) in different frequency-frequency points during the execution. This ability represents a major advantage of the proposed design which helps to optimize the time required for execution and produce an improved, cross-terms-free S/SF signal representation. The design has been verified by a field-programmable gate array (FPGA) circuit design, capable of performing S/SF analysis of 2D signals in real time.

  19. An analysis of USSPACECOM's space surveillance network sensor tasking methodology

    NASA Astrophysics Data System (ADS)

    Berger, Jeff M.; Moles, Joseph B.; Wilsey, David G.

    1992-12-01

    This study provides the basis for the development of a cost/benefit assessment model to determine the effects of alterations to the Space Surveillance Network (SSN) on orbital element (OE) set accuracy. It provides a review of current methods used by NORAD and the SSN to gather and process observations, an alternative to the current Gabbard classification method, and the development of a model to determine the effects of observation rate and correction interval on OE set accuracy. The proposed classification scheme is based on satellite J2 perturbations. Specifically, classes were established based on mean motion, eccentricity, and inclination since J2 perturbation effects are functions of only these elements. Model development began by creating representative sensor observations using a highly accurate orbital propagation model. These observations were compared to predicted observations generated using the NORAD Simplified General Perturbation (SGP4) model and differentially corrected using a Bayes, sequential estimation, algorithm. A 10-run Monte Carlo analysis was performed using this model on 12 satellites using 16 different observation rate/correction interval combinations. An ANOVA and confidence interval analysis of the results show that this model does demonstrate the differences in steady state position error based on varying observation rate and correction interval.

  20. Dual Scale Trend Analysis To Evaluate Climatic and Anthropogenic Effects on the Vegetated Land Surface in Agricultural Russia

    NASA Astrophysics Data System (ADS)

    de Beurs, K.; Henebry, G. M.

    2009-12-01

    Russia’s population is projected to shrink by a staggering 29% by 2050. Differential dynamics among rural populations are correlated with ethnicity and constitute a key driver in the spatial disintegration of rural Russia. Currently, Russia is slowly transitioning into a country with an internal “archipelago” of islands of productive agriculture around cities set within a matrix of much less productive and abandoned croplands. This heterogeneous spatial pattern is mainly driven by depopulation of the least favorable parts of the countryside, where “least favorable” is some function of lower fertility of land, higher remoteness from urban markets, or both. Our aim is to improve current understanding of the interactions of climate change and the spatio-temporal impacts of agricultural reform in European Russia. We present a dual scale trend analysis to characterize change in agricultural European Russia. We selected a global NASA MODIS product (MCD43C4 and MCD43A4) at a 0.05° (~5.6 km) and 500m spatial resolution and a 16-day temporal resolution from 2000 through 2008. We applied a refinement of the Seasonal Kendal trend method to Normalized Difference Vegetation Index (NDVI) image series at both scales. We only incorporated composites during the vegetative growing season which was delineated by start of season and end of season estimates based on analysis of Normalized Difference Infrared Index (NDII) data. Trend patterns revealed areas of increasing NDVI trend in Russia which was linked through the dual scale analysis with agricultural land cover change. The coarser scale analysis was relevant to atmospheric boundary layer processes, while the finer scale data revealed trends that were more relevant to human decision-making and regional economics. We evaluated the weather patterns and land surface phenologies for the areas with increasing NDVI over the past 9 years and compared the results with agricultural areas without change. This analysis improved