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 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

  15. 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

  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. 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.

  13. 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.

  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. 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.

  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. 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

  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. 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.

  3. 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.

  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 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.

  12. 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.

  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. 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

  15. 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.

  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. 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

  20. 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

  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. 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.

  4. 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.

  5. 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.

  6. 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…

  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)

    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.

  9. 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.

  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 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.

  17. 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.

  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. 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.

  2. 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,…

  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. 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.

  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. 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.

  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. 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.

  19. 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...

  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. 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

  3. 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%.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  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. 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

  11. 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

  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 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.

  11. 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.

  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. 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.

  15. 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

  16. 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.

  17. 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).

  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. 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.

  2. 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.

  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. 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

  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. 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…

  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. 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.

  14. 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.

  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. 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.

  3. 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

  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. 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.