WorldWideScience

Sample records for experiment phase space

  1. Critical phenomena experiments in space. [for fluid phase-equilibrium

    Science.gov (United States)

    Sengers, J. V.; Moldover, M. R.

    1978-01-01

    The paper analyzes several types of critical phenomena in fluids, shows how they are affected by the presence of gravity, and describes how experiments conducted in an orbiting laboratory under low gravity conditions could extend the range of measurements needed to study critical phenomena. Future experiments are proposed. One would be a careful measurement of the dielectric constant in a low gravity environment. Two basic problems that can benefit especially from space experiments are the specific heat near the critical point and the shear viscosity at the gas-liquid critical point.

  2. In-Space technology experiments program. A high efficiency thermal interface (using condensation heat transfer) between a 2-phase fluid loop and heatpipe radiator: Experiment definition phase

    Science.gov (United States)

    Pohner, John A.; Dempsey, Brian P.; Herold, Leroy M.

    1990-01-01

    Space Station elements and advanced military spacecraft will require rejection of tens of kilowatts of waste heat. Large space radiators and two-phase heat transport loops will be required. To minimize radiator size and weight, it is critical to minimize the temperature drop between the heat source and sink. Under an Air Force contract, a unique, high-performance heat exchanger is developed for coupling the radiator to the transport loop. Since fluid flow through the heat exchanger is driven by capillary forces which are easily dominated by gravity forces in ground testing, it is necessary to perform microgravity thermal testing to verify the design. This contract consists of an experiment definition phase leading to a preliminary design and cost estimate for a shuttle-based flight experiment of this heat exchanger design. This program will utilize modified hardware from a ground test program for the heat exchanger.

  3. Quantum optics in phase space

    CERN Document Server

    Schleich, W P; Mayr, E

    1998-01-01

    Quantum Optics in Phase Space provides a concise introduction to the rapidly moving field of quantum optics from the point of view of phase space. Modern in style and didactically skillful, Quantum Optics in Phase Space prepares students for their own research by presenting detailed derivations, many illustrations and a large set of workable problems at the end of each chapter. Often, the theoretical treatments are accompanied by the corresponding experiments. An exhaustive list of references provides a guide to the literature. Quantum Optics in Phase Space also serves advanced researchers as

  4. Gymnastics in Phase Space

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Alexander Wu; /SLAC

    2012-03-01

    As accelerator technology advances, the requirements on accelerator beam quality become increasingly demanding. Facing these new demands, the topic of phase space gymnastics is becoming a new focus of accelerator physics R&D. In a phase space gymnastics, the beam's phase space distribution is manipulated and precision tailored to meet the required beam qualities. On the other hand, all realization of such gymnastics will have to obey accelerator physics principles as well as technological limitations. Recent examples of phase space gymnastics include Emittance exchanges, Phase space exchanges, Emittance partitioning, Seeded FELs and Microbunched beams. The emittance related topics of this list are reviewed in this report. The accelerator physics basis, the optics design principles that provide these phase space manipulations, and the possible applications of these gymnastics, are discussed. This fascinating new field promises to be a powerful tool of the future.

  5. Phase space and phase space transformations

    Energy Technology Data Exchange (ETDEWEB)

    Alefeld, B.

    1985-03-01

    For neutron scattering instrumentation Liouville's theorem plays a similar role as the second law of thermodynamics at least in the sense that from time to time 'ingenious' devices are discussed seriously, which are meant to increase the phase space density, these devices are analogous to a perpetuum mobile of the second kind.

  6. Out-reach in-space technology experiments program: Control of flexible robot manipulators in zero gravity, experiment definition phase

    Science.gov (United States)

    Phillips, Warren F.

    1989-01-01

    The results obtained show that it is possible to control light-weight robots with flexible links in a manner that produces good response time and does not induce unacceptable link vibrations. However, deflections induced by gravity cause large static position errors with such a control system. For this reason, it is not possible to use this control system for controlling motion in the direction of gravity. The control system does, on the other hand, have potential for use in space. However, in-space experiments will be needed to verify its applicability to robots moving in three dimensions.

  7. Physics of Hard Spheres Experiment (PhaSE) or "Making Jello in Space"

    Science.gov (United States)

    Ling, Jerri S.; Doherty, Michael P.

    1998-01-01

    The Physics of Hard Spheres Experiment (PHaSE) is a highly successful experiment that flew aboard two shuttle missions to study the transitions involved in the formation of jellolike colloidal crystals in a microgravity environment. A colloidal suspension, or colloid, consists of fine particles, often having complex interactions, suspended in a liquid. Paint, ink, and milk are examples of colloids found in everyday life. In low Earth orbit, the effective force of gravity is thousands of times less than at the Earth's surface. This provides researchers a way to conduct experiments that cannot be adequately performed in an Earth-gravity environment. In microgravity, colloidal particles freely interact without the complications of settling that occur in normal gravity on Earth. If the particle interactions within these colloidal suspensions could be predicted and accurately modeled, they could provide the key to understanding fundamental problems in condensed matter physics and could help make possible the development of wonderful new "designer" materials. Industries that make semiconductors, electro-optics, ceramics, and composites are just a few that may benefit from this knowledge. Atomic interactions determine the physical properties (e.g., weight, color, and hardness) of ordinary matter. PHaSE uses colloidal suspensions of microscopic solid plastic spheres to model the behavior of atomic interactions. When uniformly sized hard spheres suspended in a fluid reach a certain concentration (volume fraction), the particle-fluid mixture changes from a disordered fluid state, in which the spheres are randomly organized, to an ordered "crystalline" state, in which they are structured periodically. The thermal energy of the spheres causes them to form ordered arrays, analogous to crystals. Seven of the eight PHaSE samples ranged in volume fraction from 0.483 to 0.624 to cover the range of interest, while one sample, having a concentration of 0.019, was included for

  8. Longitudinal Phase Space Tomography with Space Charge

    CERN Document Server

    Hancock, S; Lindroos, M

    2000-01-01

    Tomography is now a very broad topic with a wealth of algorithms for the reconstruction of both qualitative and quantitative images. In an extension in the domain of particle accelerators, one of the simplest algorithms has been modified to take into account the non-linearity of large-amplitude synchrotron motion. This permits the accurate reconstruction of longitudinal phase space density from one-dimensional bunch profile data. The method is a hybrid one which incorporates particle tracking. Hitherto, a very simple tracking algorithm has been employed because only a brief span of measured profile data is required to build a snapshot of phase space. This is one of the strengths of the method, as tracking for relatively few turns relaxes the precision to which input machine parameters need to be known. The recent addition of longitudinal space charge considerations as an optional refinement of the code is described. Simplicity suggested an approach based on the derivative of bunch shape with the properties of...

  9. Quantum mechanics in phase space

    DEFF Research Database (Denmark)

    Hansen, Frank

    1984-01-01

    A reformulation of quantum mechanics for a finite system is given using twisted multiplication of functions on phase space and Tomita's theory of generalized Hilbert algebras. Quantization of a classical observable h is achieved when the twisted exponential Exp0(-h) is defined as a tempered...

  10. Longitudinal phase space tomography with space charge

    Directory of Open Access Journals (Sweden)

    S. Hancock

    2000-12-01

    Full Text Available Tomography is now a very broad topic with a wealth of algorithms for the reconstruction of both qualitative and quantitative images. In an extension in the domain of particle accelerators, one of the simplest algorithms has been modified to take into account the nonlinearity of large-amplitude synchrotron motion. This permits the accurate reconstruction of longitudinal phase space density from one-dimensional bunch profile data. The method is a hybrid one which incorporates particle tracking. Hitherto, a very simple tracking algorithm has been employed because only a brief span of measured profile data is required to build a snapshot of phase space. This is one of the strengths of the method, as tracking for relatively few turns relaxes the precision to which input machine parameters need to be known. The recent addition of longitudinal space charge considerations as an optional refinement of the code is described. Simplicity suggested an approach based on the derivative of bunch shape with the properties of the vacuum chamber parametrized by a single value of distributed reactive impedance and by a geometrical coupling coefficient. This is sufficient to model the dominant collective effects in machines of low to moderate energy. In contrast to simulation codes, binning is not an issue since the profiles to be differentiated are measured ones. The program is written in Fortran 90 with high-performance Fortran extensions for parallel processing. A major effort has been made to identify and remove execution bottlenecks, for example, by reducing floating-point calculations and recoding slow intrinsic functions. A pointerlike mechanism which avoids the problems associated with pointers and parallel processing has been implemented. This is required to handle the large, sparse matrices that the algorithm employs. Results obtained with and without the inclusion of space charge are presented and compared for proton beams in the CERN protron synchrotron

  11. Quantum Shuttle in Phase Space

    DEFF Research Database (Denmark)

    Novotny, Tomas; Donarini, Andrea; Jauho, Antti-Pekka

    2003-01-01

    Abstract: We present a quantum theory of the shuttle instability in electronic transport through a nanostructure with a mechanical degree of freedom. A phase space formulation in terms of the Wigner function allows us to identify a crossover from the tunneling to the shuttling regime, thus...... extending the previously found classical results to the quantum domain. Further, a new dynamical regime is discovered, where the shuttling is driven exclusively by the quantum noise....

  12. Chaotic eigenfunctions in phase space

    CERN Document Server

    Nonnenmacher, S

    1997-01-01

    We study individual eigenstates of quantized area-preserving maps on the 2-torus which are classically chaotic. In order to analyze their semiclassical behavior, we use the Bargmann-Husimi representations for quantum states, as well as their stellar parametrization, which encodes states through a minimal set of points in phase space (the constellation of zeros of the Husimi density). We rigorously prove that a semiclassical uniform distribution of Husimi densities on the torus entails a similar equidistribution for the corresponding constellations. We deduce from this property a universal behavior for the phase patterns of chaotic Bargmann eigenfunctions, which reminds of the WKB approximation for eigenstates of integrable systems (though in a weaker sense). In order to obtain more precise information on ``chaotic eigenconstellations", we then model their properties by ensembles of random states, generalizing former results on the 2-sphere to the torus geometry. This approach yields statistical predictions fo...

  13. Passive longitudinal phase space linearizer

    Directory of Open Access Journals (Sweden)

    P. Craievich

    2010-03-01

    Full Text Available We report on the possibility to passively linearize the bunch compression process in electron linacs for the next generation x-ray free electron lasers. This can be done by using the monopole wakefields in a dielectric-lined waveguide. The optimum longitudinal voltage loss over the length of the bunch is calculated in order to compensate both the second-order rf time curvature and the second-order momentum compaction terms. Thus, the longitudinal phase space after the compression process is linearized up to a fourth-order term introduced by the convolution between the bunch and the monopole wake function.

  14. Materials science experiments in space

    Science.gov (United States)

    Gelles, S. H.; Giessen, B. C.; Glicksman, M. E.; Margrave, J. L.; Markovitz, H.; Nowick, A. S.; Verhoeven, J. D.; Witt, A. F.

    1978-01-01

    The criteria for the selection of the experimental areas and individual experiments were that the experiment or area must make a meaningful contribution to the field of material science and that the space environment was either an absolute requirement for the successful execution of the experiment or that the experiment can be more economically or more conveniently performed in space. A number of experimental areas and individual experiments were recommended for further consideration as space experiments. Areas not considered to be fruitful and others needing additional analysis in order to determine their suitability for conduct in space are also listed. Recommendations were made concerning the manner in which these materials science experiments are carried out and the related studies that should be pursued.

  15. Experiences in Space Science.

    Science.gov (United States)

    National Aeronautics and Space Administration, Washington, DC. Educational Programs Div.

    This publication contains descriptions of space science activities that can be conducted with simple equipment. There are activities suitable for both elementary and secondary school children. Activities are placed under the headings: Astronomy, Atmosphere, Universal Gravitation, Aerodynamics, Guidance and Propulsion, Tracking and Communications,…

  16. Measurements in the Forward Phase-Space with the CMS Experiment and their Impact on Physics of Extensive Air Showers

    CERN Document Server

    AUTHOR|(CDS)2083313; Quast, Günter; Ulrich, Ralf

    2015-11-18

    The astrophysical interpretation of ultra-high energy cosmic rays is based on detection of extensive air showers in indirect measurements. Hadronic interaction models that are needed for such analyses require parameters to be adjusted to collider data since soft particle production cannot be calculated from first principles. Within this work, the program CRMC was developed that unifies all air shower hadronic interaction models and supports the output formats used by collider experiments. Almost all LHC experiments have adopted the use these hadronic interaction models thanks to CRMC. The program can even be used in detector simulations to make direct comparison to reconstructed quantities from which the cosmic ray and the particle physics communities benefit immensely. Furthermore, nuclear effects were studied with the CMS experiments at the LHC. The production cross section was derived in recent proton-lead collision data at sqrt(s(NN)) = 5.02 TeV in order to study nuclear effects. The measurement constrain...

  17. The eigenvalue problem in phase space.

    Science.gov (United States)

    Cohen, Leon

    2017-07-27

    We formulate the standard quantum mechanical eigenvalue problem in quantum phase space. The equation obtained involves the c-function that corresponds to the quantum operator. We use the Wigner distribution for the phase space function. We argue that the phase space eigenvalue equation obtained has, in addition to the proper solutions, improper solutions. That is, solutions for which no wave function exists which could generate the distribution. We discuss the conditions for ascertaining whether a position momentum function is a proper phase space distribution. We call these conditions psi-representability conditions, and show that if these conditions are imposed, one extracts the correct phase space eigenfunctions. We also derive the phase space eigenvalue equation for arbitrary phase space distributions functions. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  18. Fundamental Physics with Space Experiments

    Science.gov (United States)

    Vitale, S.

    I review a category of experiments in fundamental physics that need space as a laboratory. All these experiments have in common the need of a very low gravity environment to achieve as an ideal free fall as possible: LISA, the gravitational wave observatory, and its technology demonstrator SMART-2. The satellite tests of the equivalence principle Microscope, and the ultimate sensitivity one STEP, with its close heritage from GP-B, the experiment to measure the gravito-magnetic field of the Earth. Finally the entirely new field of cold atoms in space with its promise to produce the next generation of inertial gravitational and inertial sensors for general relativity experiments.

  19. Noncommutative phase spaces on Aristotle group

    Directory of Open Access Journals (Sweden)

    Ancille Ngendakumana

    2012-03-01

    Full Text Available We realize noncommutative phase spaces as coadjoint orbits of extensions of the Aristotle group in a two dimensional space. Through these constructions the momenta of the phase spaces do not commute due to the presence of a naturally introduced magnetic eld. These cases correspond to the minimal coupling of the momentum with a magnetic potential.

  20. ERA-experiment ``space biochemistry''

    Science.gov (United States)

    Dose, K.; Bieger-Dose, A.; Dillmann, R.; Gill, M.; Kerz, O.; Klein, A.; Meinert, H.; Nawroth, T.; Risi, S.; Stridde, C.

    The general goal of the experiment was to study the response of anhydrobiotic (metabolically dormant) microorganisms (spores of Bacillus subtilis, cells of Deinococcus radiodurans, conidia of Aspergillus species) and cellular constituents (plasmid DNA, proteins, purple membranes, amino acids, urea) to the extremely dehydrating conditions of open space, in some cases in combination with irradiation by solar UV-light. Methods of investigation included viability tests, analysis of DNA damages (strand breaks, DNA-protein cross-links) and analysis of chemical effects by spectroscopic, electrophoretic and chromatographic methods. The decrease in viability of the microorganisms was as expected from simulation experiments in the laboratory. Accordingly, it could be correlated with the increase in DNA damages. The purple membranes, amino acids and urea were not measurably effected by the dehydrating condition of open space (in the dark). Plasmid DNA, however, suffered a significant amount of strand breaks under these conditions. The response of these biomolecules to high fluences of short wavelength solar UV-light is very complex. Only a brief survey can be given in this paper. The data on the relatively good survival of some of the microorganisms call for strict observance of COSPAR Planetary Protection Regulations during interplanetary space missions.

  1. The Creation of Experience Spaces

    DEFF Research Database (Denmark)

    Pedersen, Michael Thyrrestrup

    2013-01-01

    is increasingly sought used as an instrument for attracting people and economy. In the context of Danish cultural policy and planning, the governmental strategy of creating Culture Regions as a means to the goal of creating better cultural offers for people in the region; has led to a new spatial order...... for the theoretical discussions, mainly inspired by Harvey (2009), Brenner (2004) and Mackinnon (2010), to put in to context the relations between national – regional – municipal, in the light of relational space (Massey, 2005) and the quality of place (Healey, 2010). The third space of Soja (1996) will be addressed......-creating production of imaginaries – a primary source for the experience economy. This relational approach to development and to periphery can be seen for example in different niche development projects - linking to discussions on the scale of development and the scale of periphery. The empirical analysis...

  2. Resonance controlled transport in phase space

    Science.gov (United States)

    Leoncini, Xavier; Vasiliev, Alexei; Artemyev, Anton

    2018-02-01

    We consider the mechanism of controlling particle transport in phase space by means of resonances in an adiabatic setting. Using a model problem describing nonlinear wave-particle interaction, we show that captures into resonances can be used to control transport in momentum space as well as in physical space. We design the model system to provide creation of a narrow peak in the distribution function, thus producing effective cooling of a sub-ensemble of the particles.

  3. NASA physics and chemistry experiments in-space program

    Science.gov (United States)

    Gabris, E. A.

    1981-01-01

    The Physics and Chemistry Experiments Program (PACE) is part of the Office of Aeronautics and Space Technology (OAST) research and technology effort in understanding the fundamental characteristics of physics and chemical phenomena. This program seeks to increase the basic knowledge in these areas by well-planned research efforts which include in-space experiments when the limitations of ground-based activities precludes or restricts the achievement of research goals. Overview study areas are concerned with molecular beam experiments for Space Shuttle, experiments on drops and bubbles in a manned earth-orbiting laboratory, the study of combustion experiments in space, combustion experiments in orbiting spacecraft, gravitation experiments in space, and fluid physics, thermodynamics, and heat-transfer experiments. Procedures for the study program have four phases. An overview study was conducted in the area of materials science.

  4. Phase space methods for degenerate quantum gases

    CERN Document Server

    Dalton, Bryan J; Barnett, Stephen M

    2015-01-01

    Recent experimental progress has enabled cold atomic gases to be studied at nano-kelvin temperatures, creating new states of matter where quantum degeneracy occurs - Bose-Einstein condensates and degenerate Fermi gases. Such quantum states are of macroscopic dimensions. This book presents the phase space theory approach for treating the physics of degenerate quantum gases, an approach already widely used in quantum optics. However, degenerate quantum gases involve massive bosonic and fermionic atoms, not massless photons. The book begins with a review of Fock states for systems of identical atoms, where large numbers of atoms occupy the various single particle states or modes. First, separate modes are considered, and here the quantum density operator is represented by a phase space distribution function of phase space variables which replace mode annihilation, creation operators, the dynamical equation for the density operator determines a Fokker-Planck equation for the distribution function, and measurable...

  5. Critical velocity experiments in space

    Science.gov (United States)

    Torbert, R. B.

    1988-01-01

    Published data from active space experiments designed to demonstrate the Alfven critical-velocity effect are compiled in graphs and compared with the predictions of numerical simulations. It is found that the discrepancies in the ionization yields obtained in shaped-charge releases of alkali metals are related to the macroscopic limits of time and energy in such releases. It is argued that the total ionization yield is an inadequate measure of the critical-velocity effect, and a new criterion based on eta, the efficiency of energy transfer from the recently ionized neutrals to a heated electron population, is proposed: the effect would be verified if eta values of 10 percent or greater were observed.

  6. Using the Phase Space to Design Complexity

    DEFF Research Database (Denmark)

    Heinrich, Mary Katherine; Ayres, Phil

    2016-01-01

    Architecture that is responsive, adaptive, or interactive can contain active architectural elements or robotic sensor-actuator systems. The consideration of architectural robotic elements that utilize distributed control and distributed communication allows for self-organization, emergence...... it to the realm of computational design in architecture, specifically by considering the phase space and related concepts. We consider the scale and predictability of certain design characteristics, and originate the concept of a formation space extension to the phase space, for design to deal directly...... with materializations left by robot swarms or elements, rather than robots' internal states. We detail a case study examination of design methodology using the formation space concept for assessment and decision-making in the design of active architectural artifacts....

  7. Grassmann phase space theory for fermions

    Energy Technology Data Exchange (ETDEWEB)

    Dalton, Bryan J. [Centre for Quantum and Optical Science, Swinburne University of Technology, Melbourne, Victoria, 3122 (Australia); Jeffers, John [Department of Physics, University of Strathclyde, Glasgow, G4 ONG (United Kingdom); Barnett, Stephen M. [School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ (United Kingdom)

    2017-06-15

    A phase space theory for fermions has been developed using Grassmann phase space variables which can be used in numerical calculations for cold Fermi gases and for large fermion numbers. Numerical calculations are feasible because Grassmann stochastic variables at later times are related linearly to such variables at earlier times via c-number stochastic quantities. A Grassmann field version has been developed making large fermion number applications possible. Applications are shown for few mode and field theory cases. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Identifying Phase Space Boundaries with Voronoi Tessellations

    CERN Document Server

    Debnath, Dipsikha; Kilic, Can; Kim, Doojin; Matchev, Konstantin T.; Yang, Yuan-Pao

    2016-11-24

    Determining the masses of new physics particles appearing in decay chains is an important and longstanding problem in high energy phenomenology. Recently it has been shown that these mass measurements can be improved by utilizing the boundary of the allowed region in the fully differentiable phase space in its full dimensionality. Here we show that the practical challenge of identifying this boundary can be solved using techniques based on the geometric properties of the cells resulting from Voronoi tessellations of the relevant data. The robust detection of such phase space boundaries in the data could also be used to corroborate a new physics discovery based on a cut-and-count analysis.

  9. Quantum entropy production in phase space

    Science.gov (United States)

    Deffner, Sebastian

    2014-03-01

    A fluctuation theorem for the nonequilibrium entropy production in quantum phase space is derived, which enables the consistent thermodynamic description of arbitrary quantum systems, open and closed. The new treatment naturally generalizes classical results to the quantum domain. As an illustration the harmonic oscillator dragged through a thermal bath is solved numerically. Finally, the significance of the new approach is discussed in detail, and the phase space treatment is opposed to the two time energy measurement approach. We acknowledge financial support by a fellowship within the postdoc-program of the German Academic Exchange Service (DAAD, contract No D/11/40955) and from the National Science Foundation (USA) under grant DMR-1206971.

  10. Noether symmetries in the phase space

    Directory of Open Access Journals (Sweden)

    Bogar Díaz

    2014-09-01

    Full Text Available The constants of motion of a mechanical system with a finite number of degrees of freedom are related to the variational symmetries of a Lagrangian constructed from the Hamiltonian of the original system. The configuration space for this Lagrangian is the phase space of the original system. The symmetries considered in this manner include transformations of the time and may not be canonical in the standard sense.

  11. Chaotic systems in complex phase space

    Indian Academy of Sciences (India)

    Abstract. This paper examines numerically the complex classical trajectories of the kicked rotor and the double pendulum. Both of these systems exhibit a transition to chaos, and this feature is studied in complex phase space. Additionally, it is shown that the short-time and long-time behaviours of these two PT -symmetric ...

  12. Chaotic systems in complex phase space

    Indian Academy of Sciences (India)

    This paper examines numerically the complex classical trajectories of the kicked rotor and the double pendulum. Both of these systems exhibit a transition to chaos, and this feature is studied in complex phase space. Additionally, it is shown that the short-time and long-time behaviours of these two P T -symmetric dynamical ...

  13. Phase space diffusion in turbulent plasmas

    DEFF Research Database (Denmark)

    Pécseli, Hans

    1990-01-01

    Turbulent diffusion of charged test particles in electrostatic plasma turbulence is reviewed. Two different types of test particles can be distinguished. First passive particles which are subject to the fluctuating electric fields without themselves contributing to the local space charge. The sec......Turbulent diffusion of charged test particles in electrostatic plasma turbulence is reviewed. Two different types of test particles can be distinguished. First passive particles which are subject to the fluctuating electric fields without themselves contributing to the local space charge....... The second type are particles introduced at a prescribed phase space position at a certain time and which then self-consistently participate in the phase space dynamics of the turbulence. The latter "active" type of particles can be subject to an effective frictional force due to radiation of plasma waves....... In terms of these test particle types, two basically different problems can be formulated. One deals with the diffusion of a particle with respect to its point of release in phase space. Alternatively the relative diffusion between many, or just two, particles can be analyzed. Analytical expressions...

  14. Thermodynamic Products in the Extended Phase Space

    CERN Document Server

    Pradhan, Parthapratim

    2016-01-01

    We have examined the thermodynamic properties of spherically symmetric charged-AdS black hole, charged AdS BH surrounded by quintessence and charged AdS BH in $f(R)$ gravity in the extended phase-space. Where the cosmological constant should be treated as thermodynamic pressure and its conjugate parameter as thermodynamic volume. Then they should behave as a analog of Van der Waal like systems. In the extended phase space we have calculated the \\emph{entropy product} and \\emph{thermodynamic volume product} of all horizons. The mass(or enthalpy) independent nature of the said products signals they are "universal" quantities. Various types of pictorial diagram of the specific heat is given. The divergence of the specific heat indicates that the second order phase transition occurs under certain condition.

  15. The Quantum Space Phase Transitions for Particles and Force Fields

    OpenAIRE

    Chung D.-Y.; Krasnoholovets V.

    2006-01-01

    We introduce a phenomenological formalism in which the space structure is treated in terms of attachment space and detachment space. Attachment space attaches to an object, while detachment space detaches from the object. The combination of these spaces results in three quantum space phases: binary partition space, miscible space and binary lattice space. Binary lattice space consists of repetitive units of alternative attachment space and detachment spac...

  16. Space market model development project, phase 3

    Science.gov (United States)

    Bishop, Peter C.; Hamel, Gary P.

    1989-01-01

    The results of a research project investigating information needs for space commercialization is described. The Space Market Model Development Project (SMMDP) was designed to help NASA identify the information needs of the business community and to explore means to meet those needs. The activity of the SMMDP is reviewed and a report of its operation via three sections is presented. The first part contains a brief historical review of the project since inception. The next part reports results of Phase 3, the most recent stage of activity. Finally, overall conclusions and observations based on the SMMDP research results are presented.

  17. Phase transitions in de Sitter space

    Directory of Open Access Journals (Sweden)

    Alexander Vilenkin

    1983-10-01

    Full Text Available An effective potential in de Sitter space is calculated for a model of two interacting scalar fields in one-loop approximation and in a self-consistent approximation which takes into account an infinite set of diagrams. Various approaches to renormalization in de Sitter space are discussed. The results are applied to analyze the phase transition in the Hawking-Moss version of the inflationary universe scenario. Requiring that inflation is sufficiently large, we derive constraints on the parameters of the model.

  18. ESRO study program for a space experiment on gravitation theories

    Science.gov (United States)

    Israel, G. M.

    1971-01-01

    ESRO is considering a space experiment which is the definition phase. A more complete utilization of space techniques, leading to highly accurate acceleration measurements in a heliocentric spacecraft, together with an improved laser signal propagation method (using a space-borne atomic clock), could substantially increase the validity of the gravitational time delay test during solar conjunction. Preliminary investigations of the primary required techniques were carried out. These studies included an orbit analysis, investigation of drag-free techniques, and studies of the time measuring instrument. These studies were used to define the framework of a space experiment on gravitation theories. A preliminary feasibility study of the mission is being undertaken.

  19. Relativistic transformation of phase-space distributions

    Directory of Open Access Journals (Sweden)

    R. A. Treumann

    2011-07-01

    Full Text Available We investigate the transformation of the distribution function in the relativistic case, a problem of interest in plasma when particles with high (relativistic velocities come into play as for instance in radiation belt physics, in the electron-cyclotron maser radiation theory, in the vicinity of high-Mach number shocks where particles are accelerated to high speeds, and generally in solar and astrophysical plasmas. We show that the phase-space volume element is a Lorentz constant and construct the general particle distribution function from first principles. Application to thermal equilibrium lets us derive a modified version of the isotropic relativistic thermal distribution, the modified Jüttner distribution corrected for the Lorentz-invariant phase-space volume element. Finally, we discuss the relativistic modification of a number of plasma parameters.

  20. Phase Space Invertible Asynchronous Cellular Automata

    Directory of Open Access Journals (Sweden)

    Simon Wacker

    2012-08-01

    Full Text Available While for synchronous deterministic cellular automata there is an accepted definition of reversibility, the situation is less clear for asynchronous cellular automata. We first discuss a few possibilities and then investigate what we call phase space invertible asynchronous cellular automata in more detail. We will show that for each Turing machine there is such a cellular automaton simulating it, and that it is decidable whether an asynchronous cellular automaton has this property or not, even in higher dimensions.

  1. Entropy production in continuous phase space systems

    OpenAIRE

    Luposchainsky, David; Hinrichsen, Haye

    2013-01-01

    We propose an alternative method to compute the entropy production of a classical underdamped nonequilibrium system in a continuous phase space. This approach has the advantage that it is not necessary to distinguish between even and odd-parity variables. We show that the method leads to the same local entropy production as in previous studies while the differential entropy production along a stochastic trajectory turns out to be different. This demonstrates that the differential entropy prod...

  2. Semiclassical TEM image formation in phase space.

    Science.gov (United States)

    Lubk, Axel; Röder, Falk

    2015-04-01

    Current developments in TEM such as high-resolution imaging at low acceleration voltages and large fields of view, the ever larger capabilities of hardware aberration correction and the systematic shaping of electron beams require accurate descriptions of TEM imaging in terms of wave optics. Since full quantum mechanic solutions have not yet been established for, e.g., the theory of aberrations, we are exploring semiclassical image formation in the TEM from the perspective of quantum mechanical phase space, here. Firstly, we use two well-known semiclassical approximations, Miller's semiclassical algebra and the frozen Gaussian method, for describing the wave optical generalization of arbitrary geometric aberrations, including nonisoplanatic and slope aberrations. Secondly, we demonstrate that the Wigner function representation of phase space is well suited to also describe incoherent aberrations as well as the ramifications of partial coherence due to the emission process at the electron source. We identify a close relationship between classical phase space and Wigner function distortions due to aberrations as well as classical brightness and quantum mechanical purity. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Periodic orbits and TDHF phase space structure

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Yukio; Iwasawa, Kazuo [Tsukuba Univ., Ibaraki (Japan). Inst. of Physics; Tsukuma, Hidehiko; Sakata, Fumihiko

    1998-03-01

    The collective motion of atomic nuclei is closely coupled with the motion of nucleons, therefore, it is nonlinear, and the contents of the motion change largely with the increase of its amplitude. As the framework which describes the collective motion accompanied by the change of internal structure, time-dependent Hurtley Fock (TDHF) method is suitable. At present, the authors try to make the method for studying the large region structure in quantum system by utilizing the features of the TDHF phase space. The studies made so far are briefed. In this report, the correspondence of the large region patterns appearing in the band structure chart of three-level model with the periodic orbit group in the TDHF phase space is described. The Husimi function is made, and it possesses the information on the form of respective corresponding intrinsic state. The method of making the band structure chart is explained. There are three kinds of the tendency in the intrinsic state group. The E-T charts are made for the band structure charts to quantitatively express the large region tendency. The E-T chart and the T{sub r}-T chart are drawn for a selected characteristic orbit group. It became to be known that the large region properties of the quantum intrinsic state group of three-level model can be forecast by examining the properties of the periodic orbit group in the TDHF phase space. (K.I.)

  4. An in-space wireless energy transmission experiment

    Energy Technology Data Exchange (ETDEWEB)

    McSpadden, J.O.; Little, F.E. [Texas A and M Univ., College Station, TX (United States); Duke, M.B. [Lunar and Planetary Inst., Houston, TX (United States); Ignatiev, A. [Univ. of Houston, TX (United States). Space Vacuum Epitaxy Center

    1996-12-31

    The concept for an orbiting power satellite capable of supplying the needs of several co-orbiting manufacturing satellites is similar to the central power station and distribution network found on Earth. An experiment for testing a portion of such an ``Orbital Power and Light`` space power utility system--a retrodirective phased array energy transmission system in space--is described. The experiment will demonstrate the ability of a wireless power transmission system to acquire and maintain a target in space. The experiment will consist of a planar phased array antenna on the Space Shuttle beaming to a target rectenna with a pilot guide beam on the free flying Wake Shield Facility (WSF).

  5. Experiments Program for NASA's Space Communications Testbed

    Science.gov (United States)

    Chelmins, David; Reinhart, Richard

    2012-01-01

    NASA developed a testbed for communications and navigation that was launched to the International Space Station in 2012. The testbed promotes new software defined radio (SDR) technologies and addresses associated operational concepts for space-based SDRs, enabled by this first flight of NASA's Space Telecommunications Radio System (STRS) architecture standard. The experiments program consists of a mix of in-house and external experiments from partners in industry, academia, and government. The experiments will investigate key challenges in communications, networking, and global positioning system navigation both on the ground and on orbit. This presentation will discuss some of the key opportunities and challenges for the testbed experiments program.

  6. Biotechnological experiments in space flights on board of space stations

    Science.gov (United States)

    Nechitailo, Galina S.

    2012-07-01

    Space flight conditions are stressful for any plant and cause structural-functional transition due to mobiliation of adaptivity. In space flight experiments with pea tissue, wheat and arabidopsis we found anatomical-morphological transformations and biochemistry of plants. In following experiments, tissue of stevia (Stevia rebaudiana), potato (Solanum tuberosum), callus culture and culture and bulbs of suffron (Crocus sativus), callus culture of ginseng (Panax ginseng) were investigated. Experiments with stevia carried out in special chambers. The duration of experiment was 8-14 days. Board lamp was used for illumination of the plants. After experiment the plants grew in the same chamber and after 50 days the plants were moved into artificial ionexchange soil. The biochemical analysis of plants was done. The total concentration of glycozides and ratio of stevioside and rebauside were found different in space and ground plants. In following generations of stevia after flight the total concentration of stevioside and rebauside remains higher than in ground plants. Experiments with callus culture of suffron carried out in tubes. Duration of space flight experiment was 8-167 days. Board lamp was used for illumination of the plants. We found picrocitina pigment in the space plants but not in ground plants. Tissue culture of ginseng was grown in special container in thermostate under stable temperature of 22 ± 0,5 C. Duration of space experiment was from 8 to 167 days. Biological activity of space flight culutre was in 5 times higher than the ground culture. This difference was observed after recultivation of space flight samples on Earth during year after flight. Callus tissue of potato was grown in tubes in thermostate under stable temperature of 22 ± 0,5 C. Duration of space experiment was from 8 to 14 days. Concentration of regenerates in flight samples was in 5 times higher than in ground samples. The space flight experiments show, that microgravity and other

  7. Dissipative fragmentation in a phase space approach

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, A.; Di Toro, M.; Bonasera, A.; Gregoire, C.; Gulminelli, F.

    Semi-classical approaches have evidenced the role of one and two-body dissipation in nucleus-nucleus collisions. On the other hand, a substantial energy dissipation and some angular momentum transfer have been observed at moderate energy where a fragmentation process is the dominant reaction mechanism. In order to analyse main features of these reactions, we developed a phenomenological model taking into account phase space constraints. The transition between deep inelastic collisions and abrasion-like fragmentation is described and a general agreement with available data is found.

  8. Optical image encryption in phase space

    Science.gov (United States)

    Liu, Jun; Xu, Xiaobin; Situ, Guohai; Wu, Quanying

    2014-11-01

    In the field of optical information security, the research of double random phase encoding is becoming deeper with each passing day, however the encryption system is linear, and the dependencies between plaintext and ciphertext is not complicated, with leaving a great hidden danger to the security of the encryption system. In this paper, we encrypted the higher dimensional Wigner distribution function of low dimensional plaintext by using the bilinear property of Wigner distribution function. Computer simulation results show that this method can not only enlarge the key space, but also break through the linear characteristic of the traditional optical encryption technology. So it can significantly improve the safety of the encryption system.

  9. Phase space structures governing reaction dynamics in rotating molecules

    NARCIS (Netherlands)

    Ciftci, Unver; Waalkens, Holger

    Recently, the phase space structures governing reaction dynamics in Hamiltonian systems have been identified and algorithms for their explicit construction have been developed. These phase space structures are induced by saddle type equilibrium points which are characteristic for reaction type

  10. On marginalization of phase-space distribution functions

    Science.gov (United States)

    Włodarz, Joachim J.

    1999-12-01

    We discuss marginalization procedures based on integration of quantum phase-space distribution functions over a family of phase-space manifolds. We show that under some conditions the resulting marginals are always nonnegative.

  11. Testing Numerical Modeling of Phase Coarsening by Microgravity Experiments

    Science.gov (United States)

    Wang, K. G.; Glicksman, M. E.

    2017-12-01

    Quantitative understanding of the morphological evolution that occurs during phase coarsening is crucial for optimization of processing procedures to control the final structure and properties of multiphase materials. Generally, ground-based experimental studies of phase coarsening in solids are limited to model alloy systems. Data from microgravity experiments on phase coarsening in Sn-Pb solid-liquid mixtures, executed on the International Space Station, are archived in NASA's Physical Sciences Informatics (PSI) system. In such microgravity experiments, it is expected that the rate of sedimentation will be greatly reduced compared with terrestrial conditions, allowing the kinetics of phase coarsening to be followed more carefully and accurately. In this work we tested existing numerical models of phase coarsening using NASA's PSI microgravity data. Specially, we compared the microstructures derived from phase-field and multiparticle diffusion simulations with those observed in microgravity experiments.

  12. Space Transportation Engine Program (STEP), phase B

    Science.gov (United States)

    1990-01-01

    The Space Transportation Engine Program (STEP) Phase 2 effort includes preliminary design and activities plan preparation that will allow smooth and time transition into a Prototype Phase and then into Phases 3, 4, and 5. A Concurrent Engineering approach using Total Quality Management (TQM) techniques, is being applied to define an oxygen-hydrogen engine. The baseline from Phase 1/1' studies was used as a point of departure for trade studies and analyses. Existing STME system models are being enhanced as more detailed module/component characteristics are determined. Preliminary designs for the open expander, closed expander, and gas generator cycles were prepared, and recommendations for cycle selection made at the Design Concept Review (DCR). As a result of July '90 DCR, and information subsequently supplied to the Technical Review Team, a gas generator cycle was selected. Results of the various Advanced Development Programs (ADP's) for the Advanced Launch Systems (ALS) were contributive to this effort. An active vehicle integration effort is supplying the NASA, Air Force, and vehicle contractors with engine parameters and data, and flowing down appropriate vehicle requirements. Engine design and analysis trade studies are being documented in a data base that was developed and is being used to organize information. To date, seventy four trade studies were input to the data base.

  13. Experimental Observations of Ion Phase-Space Vortices

    DEFF Research Database (Denmark)

    Pécseli, Hans; Armstrong, R. J.; Trulsen, J.

    1981-01-01

    Experimental observations of ion phase-space vortices are reported. The ion phase-space vortices form in the region of heated ions behind electrostatic ion acoustic shocks. The results are in qualitative agreement with numerical and analytic studies.......Experimental observations of ion phase-space vortices are reported. The ion phase-space vortices form in the region of heated ions behind electrostatic ion acoustic shocks. The results are in qualitative agreement with numerical and analytic studies....

  14. Violent relaxation in phase-space

    Science.gov (United States)

    Bindoni, D.; Secco, L.

    2008-05-01

    The problem of violent relaxation mechanism in collisionless systems from the point of view of the distribution function (DF) in μ-space is reviewed. The literature run starts from the seminal paper of Lynden-Bell [Lynden-Bell, D., 1967. MNRAS 136, 101] and is closed by that of the same author [Arad, I., Lynden-Bell, D., 2005. MNRAS 361, 385]. After some introductive sections on the stellar dynamical equilibria and on the Shannon's information theory, the different approaches follow each accompanied with its criticism on the previous works. Different coarse-grained DFs proposed by different authors have been taken into account. It appears that for a collisionless gas of a unique mass specie there is not significant discrepancies among the different approaches which converge to the same DF at the end of relaxation process. The main problem is to avoid the non observed mass segregation in the case of multi-species composition, e.g., in a star-dominated galaxy component. On this topic the results are very different and are depending on the shape and size one chooses for μ-space tiles. A great effort has been spent into the visualization of the different partitions in phase-space in order to understand clearly from what the differences arise.

  15. The Quantum Space Phase Transitions for Particles and Force Fields

    Directory of Open Access Journals (Sweden)

    Chung D.-Y.

    2006-07-01

    Full Text Available We introduce a phenomenological formalism in which the space structure is treated in terms of attachment space and detachment space. Attachment space attaches to an object, while detachment space detaches from the object. The combination of these spaces results in three quantum space phases: binary partition space, miscible space and binary lattice space. Binary lattice space consists of repetitive units of alternative attachment space and detachment space. In miscible space, attachment space is miscible to detachment space, and there is no separation between attachment space and detachment spaces. In binary partition space, detachment space and attachment space are in two separat continuous regions. The transition from wavefunction to the collapse of wavefuction under interference becomes the quantum space phase transition from binary lattice space to miscible space. At extremely conditions, the gauge boson force field undergoes a quantum space phase transition to a "hedge boson force field", consisting of a "vacuum" core surrounded by a hedge boson shell, like a bubble with boundary.

  16. The Morse oscillator in position space, momentum space, and phase space

    DEFF Research Database (Denmark)

    Dahl, Jens Peder; Springborg, Michael

    1988-01-01

    We present a unified description of the position-space wave functions, the momentum-space wave functions, and the phase-space Wigner functions for the bound states of a Morse oscillator. By comparing with the functions for the harmonic oscillator the effects of anharmonicity are visualized. Analy...... for the Morse oscillator. The Journal of Chemical Physics is copyrighted by The American Institute of Physics....

  17. Spaces of interaction, places for experience

    CERN Document Server

    Benyon, David

    2014-01-01

    Spaces of Interaction, Places for Experience is a book about Human-Computer Interaction (HCI), interaction design (ID) and user experience (UX) in the age of ubiquitous computing. The book explores interaction and experience through the different spaces that contribute to interaction until it arrives at an understanding of the rich and complex places for experience that will be the focus of the next period for interaction design. The book begins by looking at the multilayered nature of interaction and UX-not just with new technologies, but with technologies that are embedded in the world. Peop

  18. Modal survey testing of the Lidar In-space Technology Experiment (LITE) - A Space Shuttle payload

    Science.gov (United States)

    Anderson, J. B.; Coleman, A. D.; Driskill, T. C.; Lindell, M. C.

    1992-01-01

    This paper presents the results of the modal survey test of the Lidar In-space Technology Experiment (LITE), a Space Shuttle payload mounted in a Spacelab flight single pallet. The test was performed by the Dynamics Test Branch at Marshall Space Flight Center, AL and run in two phases. In the first phase, an unloaded orthogrid connected to the pallet with 52 tension struts was tested. This test included 73 measurement points in three directions. In the second phase, the pallet was integrated with mass simulators mounted on the flight support structure to represent the dynamics (weight and center of gravity) of the various components comprising the LITE experiment and instrumented at 213 points in 3 directions. The test article was suspended by an air bag system to simulate a free-free boundary condition. This paper presents the results obtained from the testing and analytical model correlation efforts. The effect of the suspension system on the test article is also discussed.

  19. Method of phase space beam dilution utilizing bounded chaos generated by rf phase modulation

    Directory of Open Access Journals (Sweden)

    Alfonse N. Pham

    2015-12-01

    Full Text Available This paper explores the physics of chaos in a localized phase-space region produced by rf phase modulation applied to a double rf system. The study can be exploited to produce rapid particle bunch broadening exhibiting longitudinal particle distribution uniformity. Hamiltonian models and particle-tracking simulations are introduced to understand the mechanism and applicability of controlled particle diffusion. When phase modulation is applied to the double rf system, regions of localized chaos are produced through the disruption and overlapping of parametric resonant islands and configured to be bounded by well-behaved invariant tori to prevent particle loss. The condition of chaoticity and the degree of particle dilution can be controlled by the rf parameters. The method has applications in alleviating adverse space-charge effects in high-intensity beams, particle bunch distribution uniformization, and industrial radiation-effects experiments.

  20. Cell biology experiments conducted in space

    Science.gov (United States)

    Taylor, G. R.

    1977-01-01

    A review of cell biology experiments conducted during the first two decades of space flight is provided. References are tabulated for work done with six types of living test system: isolated viruses, bacteriophage-host, bacteria, yeasts and filamentous fungi, protozoans, and small groups of cells (such as hamster cell tissue and fertilized frog eggs). The general results of studies involving the survival of cells in space, the effect of space flight on growing cultures, the biological effects of multicharged high-energy particles, and the effects of space flight on the genetic apparatus of microorganisms are summarized. It is concluded that cell systems remain sufficiently stable during space flight to permit experimentation with models requiring a fixed cell line during the space shuttle era.

  1. On minimalism in architecture - space as experience

    OpenAIRE

    Vasilski Dragana

    2016-01-01

    Architecture has to be experienced to be understood. The complexity of the experience is seen through a better understanding of the relationship between objectivity (architecture) and subjectivity (our life). Being physically, emotionally and psychologically aware of the space we occupy is an experience that could be described as being present, which is a sensation that is personal and difficult to explicitly describe. Research into experience through perce...

  2. Space science experiments aboard ATS-F.

    Science.gov (United States)

    Wales, R.; King, W.

    1972-01-01

    The Environmental Measurements Experiment (EME) package is mounted on the ATS-F spacecraft to a structure that is located on top of the 30-foot parabolic reflector hub. The eight experiments of the EME package are designed to study the environment in space at synchronous altitude and to obtain information on electromagnetic-ionospheric interactions. Six of these experiments will obtain data on charged particles of several different types. A seventh experiment is to provide magnetic field data. The eighth experiment is concerned with solar cell degradation studies.

  3. Phase Space Reduction of Star Products on Cotangent Bundles.

    NARCIS (Netherlands)

    Kowalzig, N.; Neumaier, N.; Pflaum, M.

    2005-01-01

    In this paper we construct star products on Marsden-Weinstein reduced spaces in case both the original phase space and the reduced phase space are (symplectomorphic to) cotangent bundles. Under the assumption that the original cotangent bundle $T^*Q$ carries a symplectic structure of form

  4. Space robotic experiment in JEM flight demonstration

    Science.gov (United States)

    Nagatomo, Masanori; Tanaka, Masaki; Nakamura, Kazuyuki; Tsuda, Shinichi

    1994-01-01

    Japan is collaborating on the multinational space station program. The JEM, Japanese Experiment Module, has both a pressurized module and an Exposed Facility (EF). JEM Remote Manipulator System (JEMRMS) will play a dominant role in handling/servicing payloads and the maintenance of the EF, and consists of two robotic arms, a main arm and a small fine arm. JEM Flight Demonstration (JFD) is a space robotics experiment using the prototype small fine arm to demonstrate its capability, prior to the Space Station operation. The small fine arm will be installed in the Space Shuttle cargo bay and operated by a crew from a dedicated workstation in the Aft Flight Deck of the orbiter.

  5. Bertrand systems and their phase space

    Directory of Open Access Journals (Sweden)

    O. A. Zagryadskij

    2014-01-01

    Full Text Available Consider a pair (S, V , where S is a two-dimensional surface of revolution without equators, i.e. cylinder equipped Riemannian metric of revolution, V is a central potential on S such that it keeps constant when the group of rotation acts. Also consider central potentials acting on the surfaces equipped Pseudoriemannian metric of revolution. Lets select Bertrand pairs in the set of all considered pairs | the potential has to be locking, i.e. under the influence of it all bounded orbits must be closed. Such dynamical systems are Hamiltonian ones possessed four-dimensional phase space. And one could represent Bertand pairs as five-parametric set, three parameters define the inner product of the manifold, other two define potential. It is proved that only generalized law of universal gravitation and the generalized oscillator Hook law could be locking.It is well-known that in case of closed orbit the period of moving depends on the full energy, but not depends on angular momentum (classical Gordon's theorem; in this paper we established the explicit form of this relation for Bertrand systems. In case of nonbounded orbits we calculated full time of moving, noted the infinite cases, and derived the fullness of corresponding phase flows, i.e. whether time-parameter could be continued to infinitely on the integral curves of Hamiltonian vector field of energy.We show, thatBertrand systemsin pseudoriemannian case weren't integrable by the Liouville| Arnold theorem, however the connected components of regular Liouvill folia of two first integrals energy and angular momentum stayed either torii or cylinders. We proved any folia of the foliation could be either circle or torus or cylinder or pair of cylinders. Also we constructed bifurcation diagrams of momentum map, all the diagrams is divided into areas corresponding to different types of Liouville folii. Finally it was discovered whether flows were full or not.

  6. Space storm as a phase transition

    Science.gov (United States)

    Wanliss, J. A.; Dobias, P.

    2007-04-01

    Fluctuations of the SYM-H index were analyzed for several space storms preceded by more than a week of extremely quiet conditions to establish that there was a rapid and unidirectional change in the Hurst scaling exponent at the time of storm onset. That is, the transition was accompanied by the specific signature of a rapid unidirectional change in the temporal fractal scaling of fluctuations in SYM-H, signaling the formation of a new dynamical phase (or mode) which was considerably more organized than the background state. We compare these results to a model of multifractional Brownian motion and suggest that the relatively sudden change from a less correlated to a more correlated pattern of multiscale fluctuations at storm onset can be characterized in terms of nonequilibrium dynamical phase transitions. The results show that a dynamical transition in solar wind VB is correlated with the storm onset for intense storms, suggesting that the dynamical transition observed in SYM-H is of external solar wind origin, rather than internal magnetospheric origin. However, some results showed a dynamical transition in solar wind scaling exponents not matched by similar transitions in SYM-H. In other instances, we observed some small storms where there was a strong dynamical transition in SYM-H without similar changes in the VB scaling statistics, suggesting that changes were due to internal magnetospheric processes. In summary, the results for intense storms points to the solar wind as being responsible for providing the scale free properties in the SYM-H fluctuations but the evidence for small storms clearly limit the importance of the solar wind fluctuations; their interaction is more complex than simple causality.

  7. Hybrid Experience Space for Cultural Heritage Communication

    DEFF Research Database (Denmark)

    Veirum, Niels Einar; Christensen, Mogens Fiil; Mayerhofer, Mikkel

    2006-01-01

    by daily use of experience products like computer-games, IMAX cinemas and theme parks featuring virtual reality installations. “It’s a question of stone-axe displays versus Disney-power installations” as one of the involved museum professionals point it, “but we don’t want any of these possibilities......”. The paper presents an actual experience design case in Zea Harbour, Greece dealing with these challenges using hybrid experience space communicating cultural heritage material. Ar-chaeological findings, physical reconstructions and digital models are mixed to effec-tively stage the interactive experience...

  8. Phase Space Cell in Nonextensive Classical Systems

    Directory of Open Access Journals (Sweden)

    Piero Quarati

    2003-06-01

    Full Text Available Abstract: We calculate the phase space volume Ω occupied by a nonextensive system of N classical particles described by an equilibrium (or steady-state, or long-term stationary state of a nonequilibrium system distribution function, which slightly deviates from Maxwell-Boltzmann (MB distribution in the high energy tail. We explicitly require that the number of accessible microstates does not change respect to the extensive MB case. We also derive, within a classical scheme, an analytical expression of the elementary cell that can be seen as a macrocell, different from the third power of Planck constant. Thermodynamic quantities like entropy, chemical potential and free energy of a classical ideal gas, depending on elementary cell, are evaluated. Considering the fractional deviation from MB distribution we can deduce a physical meaning of the nonextensive parameter q of the Tsallis nonextensive thermostatistics in terms of particle correlation functions (valid at least in the case, discussed in this work, of small deviations from MB standard case.

  9. Space market model development project, phase 2

    Science.gov (United States)

    Bishop, Peter C.

    1988-01-01

    The results of the prototype operations of the Space Business Information Center are presented. A clearinghouse for space business information for members of the U.S. space industry composed of public, private, and academic sectors was conducted. Behavioral and evaluation statistics were recorded from the clearinghouse and the conclusions from these statistics are presented. Business guidebooks on major markets in space business are discussed. Proprietary research and briefings for firms and agencies in the space industry are also discussed.

  10. Overview of Phase Space Manipulations of Relativistic Electron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Dao; /SLAC

    2012-08-31

    Phase space manipulation is a process to rearrange beam's distribution in 6-D phase space. In this paper, we give an overview of the techniques for tailoring beam distribution in 2D, 4D, and 6D phase space to meet the requirements of various applications. These techniques become a new focus of accelerator physics R&D and very likely these advanced concepts will open up new opportunities in advanced accelerators and the science enabled by them.

  11. Invulnerability, coping, salutogenesis, integration: four phases of space psychology.

    Science.gov (United States)

    Suedfeld, Peter

    2005-06-01

    The relationship between NASA and the psychological research community has progressed through a number of phases during the past four decades. This paper summarizes how the relationship has developed as data have accumulated and space missions and crews have changed. In the beginning, most NASA astronauts and staff considered possible psychological problems during space missions to be a non-issue. It was assumed that people with "the right stuff" would not experience any such problems. A more realistic recognition of stress and its consequences has led to a concern with prevention and countermeasures, a concern that has come to dominate NASA's involvement with psychology. Very recently, space psychologists have started to import the concepts of positive psychology, and consider the benefits of participation in the space program, including the self-enhancing aspects of stressful experiences (salutogenesis). Both the agency and psychologists now need to broaden their thinking and their research to cover the gamut of empirical data and theoretical concepts. These include human strengths as well as vulnerabilities, both negative and positive impacts of spaceflight, long- as well as short-term effects, and the reactions not only of the astronauts themselves but also of ground personnel and the families of both groups.

  12. Phase-space topography characterization of nonlinear ultrasound waveforms.

    Science.gov (United States)

    Dehghan-Niri, Ehsan; Al-Beer, Helem

    2018-03-01

    Fundamental understanding of ultrasound interaction with material discontinuities having closed interfaces has many engineering applications such as nondestructive evaluation of defects like kissing bonds and cracks in critical structural and mechanical components. In this paper, to analyze the acoustic field nonlinearities due to defects with closed interfaces, the use of a common technique in nonlinear physics, based on a phase-space topography construction of ultrasound waveform, is proposed. The central idea is to complement the "time" and "frequency" domain analyses with the "phase-space" domain analysis of nonlinear ultrasound waveforms. A nonlinear time series method known as pseudo phase-space topography construction is used to construct equivalent phase-space portrait of measured ultrasound waveforms. Several nonlinear models are considered to numerically simulate nonlinear ultrasound waveforms. The phase-space response of the simulated waveforms is shown to provide different topographic information, while the frequency domain shows similar spectral behavior. Thus, model classification can be substantially enhanced in the phase-space domain. Experimental results on high strength aluminum samples show that the phase-space transformation provides a unique detection and classification capabilities. The Poincaré map of the phase-space domain is also used to better understand the nonlinear behavior of ultrasound waveforms. It is shown that the analysis of ultrasound nonlinearities is more convenient and informative in the phase-space domain than in the frequency domain. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Cuban Techno-physical Experiments in Space

    Science.gov (United States)

    Altshuler, José; Calzadilla Amaya, Ocatvio; Falcon, Federico; Fuentes, Juan E.; Lodos, Jorge; Vigil Santos, Elena

    When Cuba joined the Intercosmos Program of the socialist countries in the mid-1960s, the great educational and scientific reform taking place at that time in the country had hardly begun to bear fruit. But when, a decade later, the Soviet Union offered all the participant countries the chance to make use of its space vehicles and related installations so that their cosmonauts could carry out original scientific experiments in space, the situation had changed radically in Cuba. In a short time around 200 people already involved in scientific and technological activities succeeded in designing and setting up—in close collaboration with various Soviet, East German and Bulgarian institutions—some 20 scientific experiments that were to be carried out in orbit around the earth during the joint Soviet-Cuban space flight of September 18-26, 1980. Those experiments, and a further one that was also set up for the same space flight—but carried out during a later flight, as mentioned below—are historically important since they were the first in their class to be carried out by humans in space under microgravity conditions.

  14. Tomographic measurement of the phase space distribution of a space-charge-dominated beam

    Science.gov (United States)

    Stratakis, Diktys

    Many applications of accelerators, such as free electron lasers, pulsed neutron sources, and heavy ion fusion, require a good quality beam with high intensity. In practice, the achievable intensity is often limited by the dynamics at the low-energy, space-charge dominated end of the machine. Because low-energy beams can have complex distribution functions, a good understanding of their detailed evolution is needed. To address this issue, we have developed a simple and accurate tomographic method to map the beam phase using quadrupole magnets, which includes the effects from space charge. We extend this technique to use also solenoidal magnets which are commonly used at low energies, especially in photoinjectors, thus making the diagnostic applicable to most machines. We simulate our technique using a particle in cell code (PIC), to ascertain accuracy of the reconstruction. Using this diagnostic we report a number of experiments to study and optimize injection, transport and acceleration of intense space charge dominated beams. We examine phase mixing, by studying the phase-space evolution of an intense beam with a transversely nonuniform initial density distribution. Experimental measurements, theoretical predictions and PIC simulations are in good agreement each other. Finally, we generate a parabolic beam pulse to model those beams from photoinjectors, and combine tomography with fast imaging techniques to investigate the time-sliced parameters of beam current, size, energy spread and transverse emittance. We found significant differences between the slice emittance profiles and slice orientation as the beam propagates downstream. The combined effect of longitudinal nonuniform profiles and fast imaging of the transverse phase space provided us with information about correlations between longitudinal and transverse dynamics that we report within this dissertation.

  15. Cosmology with galaxy cluster phase spaces

    Science.gov (United States)

    Stark, Alejo; Miller, Christopher J.; Huterer, Dragan

    2017-07-01

    We present a novel approach to constrain accelerating cosmologies with galaxy cluster phase spaces. With the Fisher matrix formalism we forecast constraints on the cosmological parameters that describe the cosmological expansion history. We find that our probe has the potential of providing constraints comparable to, or even stronger than, those from other cosmological probes. More specifically, with 1000 (100) clusters uniformly distributed in the redshift range 0 ≤z ≤0.8 , after applying a conservative 80% mass scatter prior on each cluster and marginalizing over all other parameters, we forecast 1 σ constraints on the dark energy equation of state w and matter density parameter ΩM of σw=0.138 (0.431 ) and σΩM=0.007(0.025 ) in a flat universe. Assuming 40% mass scatter and adding a prior on the Hubble constant we can achieve a constraint on the Chevallier-Polarski-Linder parametrization of the dark energy equation of state parameters w0 and wa with 100 clusters in the same redshift range: σw 0=0.191 and σwa=2.712. Dropping the assumption of flatness and assuming w =-1 we also attain competitive constraints on the matter and dark energy density parameters: σΩ M=0.101 and σΩ Λ=0.197 for 100 clusters uniformly distributed in the range 0 ≤z ≤0.8 after applying a prior on the Hubble constant. We also discuss various observational strategies for tightening constraints in both the near and far future.

  16. The City's new hybrid experience spaces

    DEFF Research Database (Denmark)

    Andersson, Lasse; Kiib, Hans

    2007-01-01

    serve as frameworks for traditional functions, while simultaneously taking on new roles, new meanings and new narratives. This article serves as the first tentative reflection on results from a workshop at the ‘Skanok 05'; a conference on the experience economy held in Aalborg, October 2005.In......In a series of workshops in Danish cities during the last couple of years, we have been establishing new ways of working with a clear local perspective in the new global discourse on culture, creativity and urbanity - urban innovation and urban branding in what could be called the experience city.......  We argue that " hybrid economy" and "hybrid space" can be understood as a linkage of "a traditional economy" to a new "experience economy", as well as  a merging of  "traditional private urban spaces" with "new types of public domains". This coupling is the departure point for the mental movement...

  17. On quantum mechanical phase-space wave functions

    DEFF Research Database (Denmark)

    Wlodarz, Joachim J.

    1994-01-01

    An approach to quantum mechanics based on the notion of a phase-space wave function is proposed within the Weyl-Wigner-Moyal representation. It is shown that the Schrodinger equation for the phase-space wave function is equivalent to the quantum Liouville equation for the Wigner distribution...

  18. Phase-space treatment of the driven quantum harmonic oscillator

    Indian Academy of Sciences (India)

    2017-02-22

    Feb 22, 2017 ... Phase-space quantum mechanics; coherent states; harmonic oscillator; Husimi distribution; cross- ... is the Weyl operator assigned to the phase-space ...... formulae used in this work. The Hermite polynomials satisfy the following relations: 1. [19, Section 5.6.4],. Hη(y + σ) = η. ∑ k=0. ( η k. ) Hk(y)(2σ)η−k. = η.

  19. On phase-space representations of quantum mechanics using ...

    Indian Academy of Sciences (India)

    A phase-space formulation of quantum mechanics is proposed by constructing two representations (identified as p q and q p ) in terms of the Glauber coherent states, in which phase-space wave functions (probability amplitudes) play the central role, and position q and momentum p are treated on equal footing. After finding ...

  20. On minimalism in architecture - space as experience

    Directory of Open Access Journals (Sweden)

    Vasilski Dragana

    2016-01-01

    Full Text Available Architecture has to be experienced to be understood. The complexity of the experience is seen through a better understanding of the relationship between objectivity (architecture and subjectivity (our life. Being physically, emotionally and psychologically aware of the space we occupy is an experience that could be described as being present, which is a sensation that is personal and difficult to explicitly describe. Research into experience through perception and emotion positions architecture within scientific fields, in particular psychological disciplines. Relying on the standpoints of Immanuel Kant, the paper considers the juxtaposition between (minimalism in architecture and philosophy on the topic of experience. Starting from the basic aspects of perception and representation of the world around us, a thesis is presented in which the notions of silence and light as experienced in minimalism (in architecture are considered as adequate counterparts to Kant’s factors of experience - the awareness of the objective order of events and the impossibility to perceive time itself. Through a case study we verify the starting hypothesis on minimalism (in architecture whereby space becomes an experience of how the world touches us.

  1. Emulsion chamber experiments for the Space Station

    Science.gov (United States)

    Wilkes, R. J.

    Emulsion chambers offer several unique features for the study of ultrahigh-energy cosmic-ray interactions and spectra aboard a permanent manned Space Station. Emulsion-chamber experiments provide the highest acceptance/weight ratio of any current experimental technique, are invulnerable to mechanical shocks and temperature excursions associated with space flight, do not employ volatile or explosive components or materials, and are not dependent upon data communications or recording systems. Space-Station personnel would be employed to replace track-sensitive materials as required by background accumulation. Several emulsion-chamber designs are proposed, including both conventional passive calorimetric detectors and a hybrid superconducting-magnetic-spectrometer system. Results of preliminary simulation studies are presented. Operational logistics are discussed.

  2. Real-space Berry phases: Skyrmion soccer (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Everschor-Sitte, Karin, E-mail: karin@physics.utexas.edu; Sitte, Matthias [The University of Texas at Austin, Department of Physics, 2515 Speedway, Austin, Texas 78712 (United States)

    2014-05-07

    Berry phases occur when a system adiabatically evolves along a closed curve in parameter space. This tutorial-like article focuses on Berry phases accumulated in real space. In particular, we consider the situation where an electron traverses a smooth magnetic structure, while its magnetic moment adjusts to the local magnetization direction. Mapping the adiabatic physics to an effective problem in terms of emergent fields reveals that certain magnetic textures, skyrmions, are tailormade to study these Berry phase effects.

  3. Real-space Berry phases: Skyrmion soccer (invited)

    Science.gov (United States)

    Everschor-Sitte, Karin; Sitte, Matthias

    2014-05-01

    Berry phases occur when a system adiabatically evolves along a closed curve in parameter space. This tutorial-like article focuses on Berry phases accumulated in real space. In particular, we consider the situation where an electron traverses a smooth magnetic structure, while its magnetic moment adjusts to the local magnetization direction. Mapping the adiabatic physics to an effective problem in terms of emergent fields reveals that certain magnetic textures, skyrmions, are tailormade to study these Berry phase effects.

  4. Schrodinger Equation and Phase Space in Quantum Mechanics

    OpenAIRE

    Kim, Kiyoung

    1997-01-01

    Using classical statistics, Schrodinger equation in quantum mechanics is derived from complex space model. Phase-space probability amplitude, that can be defined on classical point of view, has connections to probability amplitude in internal space and to wave function in quantum mechanics. In addition, the physical entity of wave function in quantum mechanics is confirmed once again.

  5. Drinking in Space: The Capillary Beverage Experiment

    Science.gov (United States)

    Wollman, Andrew; Weislogel, Mark; Jenson, Ryan; Graf, John; Pettit, Donald; Kelly, Scott; Lindgren, Kjell; Yui, Kimiya

    2015-11-01

    A selection from as many as 50 different drinks including coffees, teas, and fruit smoothies are consumed daily by astronauts aboard the International Space Station. For practical reasons, the drinks are generally sipped through straws inserted in sealed bags. We present the performance of a special cup designed to allow the drinking operation in much the same manner as on earth, only with the role of gravity replaced by the combined effects of surface tension, wetting, and special container geometry. One can finally `smell the coffee.' Six so-called Space Cups are currently in orbit as part of the Capillary Beverage Experiment which aims to demonstrate specific passive control of poorly wetting aqueous capillary systems through a fun mealtime activity. The mathematical fluid mechanical design process with full numerical simulations is presented alongside experimental results acquired using a drop tower and low-g aircraft before complete characterization aboard the Space Station. Astronaut commentary is both humorous and informative, but the insightful experimental results of the potable space experiment testify to the prospects of new no-moving-parts capillary solutions for certain water-based life support operations aboard spacecraft.

  6. Space Weathering Experiments on Spacecraft Materials

    Science.gov (United States)

    Cooper, R.; Cowardin, H.; Engelhar, D.; Plis, Elena; Hoffman, R.

    2017-01-01

    A project to investigate space environment effects on specific materials with interest to remote sensing was initiated in 2016. The goal of the project is to better characterize changes in the optical properties of polymers and Mylar, specifically those found in multi-layered spacecraft insulation, due to electron bombardment. Previous analysis shows that chemical bonds break and potentially reform when exposed to high energy electrons. Among other properties these chemical changes altered the optical reflectance as documented in laboratory analysis. This paper presents results of the initial experiment results focused on the exposure of materials to various fluences of high energy electrons, used to simulate a portion of the geosynchronous space environment. The paper illustrates how the spectral reflectance changes as a function of time on orbit with respect to GEO environmental factors and investigates the survivability of the material after multiple electron doses. These results provide a baseline for analysis of aging effects on satellite systems used for remote sensing. They also provide preliminary analysis on what materials are most likely to encompass the high area-to-mass population of space debris in the geosynchronous environment. Lastly, the paper provides the results of the initial experimentation as a proof of concept for space aging on polymers and Mylar for conducting more experiments with a larger subset of spacecraft materials.

  7. The HypHI Phase 0 experiment

    NARCIS (Netherlands)

    Saito, T. R.; Bianchin, S.; Borodina, O.; Bozkurt, V.; Gokuzum, B.; Kavatsyuk, M.; Kim, E.; Minami, S.; Nakajima, D.; Oezel-Tashenov, B.; Rappold, C.; Achenbach, P.; Ajimura, S.; Aumann, T.; Caesar, C.; Erturk, S.; Fukuda, T.; Guliyev, Elmaddin; Hayashi, Y.; Hiraiwa, T.; Hoffmann, J.; Ickert, G.; Ketenci, Z. S.; Khaneft, D.; Kim, M.; Kim, S.; Koch, K.; Kurz, N.; Ma, Y.; Maas, F.; Mizoi, S.; Moritsu, M.; Nagae, T.; Okamura, A.; Ott, W.; Pochodzalla, J.; Sakaguchi, A.; Sako, M.; Schmidt, C. J.; Sekimoto, M.; Simon, H.; Sugimura, H.; Takahashi, T.; Tambave, G. J.; Tanida, K.; Tamura, K.; Traeger, M.; Trautmann, W.; Voltz, S.; Yoon, C. J.; Yoshida, K.

    2010-01-01

    The HypHI Phase 0 experiment to demonstrate the feasibility of precise hypernuclear spectroscopy with induced reactions of heavy ion beams was performed at GSI in August and October in 2009, with a projectile of (6)Li at 2 A GeV impinged on carbon graphite target with a thickness of 8 g/cm(2). The

  8. LHC Experiments Phase II - TDRs Approval Process

    CERN Document Server

    Forti, F

    2017-01-01

    The overall review process and steps of Phase II were described in CERN-LHCC-2015-077. As experiments submit detailed technical design reports (TDRs), the LHCC and UCG work in close connection to ensure a timely review of the scientific and technical feasibility as well as of the budget and schedule of the upgrade programme.

  9. Tourism Spaces: The New Experience Design

    Directory of Open Access Journals (Sweden)

    Sara Cipolletti

    2014-06-01

    Full Text Available The aim of this article is to offer a theoretical contribution to the organisation, design and significance of tourism spaces, at a time when tourist practices are experiencing both change and intensification. From an architectural perspective, the study seeks to understand the evolutionary link between holiday practices and spaces, interpreting tourism as a context of creative relations between people, aspects, things and the places in which practices take place.Based on this interpretation, the paper defines architectural and urban categories of tourism, briefly comparing various literature on tourist organisations. In the second part, through the examination of recent examples of tourist experiences, planning actions and their ability to generate new tourism landscapes are evaluated. For both places and tourist experiences, that which emerges and the fields of application involved constitute guidelines and development tools for a form of tourism design that is more knowledgeable about the encounter between tourists and residents, and more reliable given that it is founded on the distinctive features of territories. The study demonstrates that tourism spaces, if intended as contexts of creative relations between people, aspects, things and places in which practices take place, may now develop a certain potential that once again calls into question a series of much debated opposites, tourists - residents, free time - work time, holiday space - day-to-day space, attractive resources and their transformation into elements of tourism, which had otherwise previously been consolidated by the tourist phenomenon. In the end, tourism proves itself to be an imaginative impulse, which is capable of reinventing the qualities of places and successfully orientating urban events.

  10. Phase space picture of quantum mechanics group theoretical approach

    CERN Document Server

    Kim, Y S

    1991-01-01

    This book covers the theory and applications of the Wigner phase space distribution function and its symmetry properties. The book explains why the phase space picture of quantum mechanics is needed, in addition to the conventional Schrödinger or Heisenberg picture. It is shown that the uncertainty relation can be represented more accurately in this picture. In addition, the phase space picture is shown to be the natural representation of quantum mechanics for modern optics and relativistic quantum mechanics of extended objects.

  11. Space Weathering Experiments on Spacecraft Materials

    Science.gov (United States)

    Engelhart, D. P.; Cooper, R.; Cowardin, H.; Maxwell, J.; Plis, E.; Ferguson, D.; Barton, D.; Schiefer, S.; Hoffmann, R.

    2017-01-01

    A project to investigate space environment effects on specific materials with interest to remote sensing was initiated in 2016. The goal of the project is to better characterize changes in the optical properties of polymers found in multi-layered spacecraft insulation (MLI) induced by electron bombardment. Previous analysis shows that chemical bonds break and potentially reform when exposed to high energy electrons like those seen in orbit. These chemical changes have been shown to alter a material's optical reflectance, among other material properties. This paper presents the initial experimental results of MLI materials exposed to various fluences of high energy electrons, designed to simulate a portion of the geosynchronous Earth orbit (GEO) space environment. It is shown that the spectral reflectance of some of the tested materials changes as a function of electron dose. These results provide an experimental benchmark for analysis of aging effects on satellite systems which can be used to improve remote sensing and space situational awareness. They also provide preliminary analysis on those materials that are most likely to comprise the high area-to-mass ratio (HAMR) population of space debris in the geosynchronous orbit environment. Finally, the results presented in this paper serve as a proof of concept for simulated environmental aging of spacecraft polymers that should lead to more experiments using a larger subset of spacecraft materials.

  12. Analysis of PFG Anomalous Diffusion via Real-Space and Phase-Space Approaches

    Directory of Open Access Journals (Sweden)

    Guoxing Lin

    2018-01-01

    Full Text Available Pulsed-field gradient (PFG diffusion experiments can be used to measure anomalous diffusion in many polymer or biological systems. However, it is still complicated to analyze PFG anomalous diffusion, particularly the finite gradient pulse width (FGPW effect. In practical applications, the FGPW effect may not be neglected, such as in clinical diffusion magnetic resonance imaging (MRI. Here, two significantly different methods are proposed to analyze PFG anomalous diffusion: the effective phase-shift diffusion equation (EPSDE method and a method based on observing the signal intensity at the origin. The EPSDE method describes the phase evolution in virtual phase space, while the method to observe the signal intensity at the origin describes the magnetization evolution in real space. However, these two approaches give the same general PFG signal attenuation including the FGPW effect, which can be numerically evaluated by a direct integration method. The direct integration method is fast and without overflow. It is a convenient numerical evaluation method for Mittag-Leffler function-type PFG signal attenuation. The methods here provide a clear view of spin evolution under a field gradient, and their results will help the analysis of PFG anomalous diffusion.

  13. Reading Neural Encodings using Phase Space Methods

    OpenAIRE

    Abarbanel, Henry D. I.; Tumer, Evren C.

    2003-01-01

    Environmental signals sensed by nervous systems are often represented in spike trains carried from sensory neurons to higher neural functions where decisions and functional actions occur. Information about the environmental stimulus is contained (encoded) in the train of spikes. We show how to "read" the encoding using state space methods of nonlinear dynamics. We create a mapping from spike signals which are output from the neural processing system back to an estimate of the analog input sig...

  14. Explaining Gibbsean phase space to second year students

    Energy Technology Data Exchange (ETDEWEB)

    Vesely, Franz J [Institute of Experimental Physics, University of Vienna (Austria)

    2005-03-01

    A new approach to teaching introductory statistical physics is presented. We recommend making extensive use of the fact that even systems with a very few degrees of freedom may display chaotic behaviour. This permits a didactic 'bottom-up' approach, starting out with toy systems whose phase space may be depicted on a screen or blackboard, then proceeding to ever higher dimensions in Gibbsean phase space.

  15. Group theoretical construction of planar noncommutative phase spaces

    Energy Technology Data Exchange (ETDEWEB)

    Ngendakumana, Ancille, E-mail: nancille@yahoo.fr; Todjihoundé, Leonard, E-mail: leonardt@imsp.uac.org [Institut de Mathématiques et des Sciences Physiques (IMSP), Porto-Novo (Benin); Nzotungicimpaye, Joachim, E-mail: kimpaye@kie.ac.rw [Kigali Institute of Education (KIE), Kigali (Rwanda)

    2014-01-15

    Noncommutative phase spaces are generated and classified in the framework of centrally extended anisotropic planar kinematical Lie groups as well as in the framework of noncentrally abelian extended planar absolute time Lie groups. Through these constructions the coordinates of the phase spaces do not commute due to the presence of naturally introduced fields giving rise to minimal couplings. By symplectic realizations methods, physical interpretations of generators coming from the obtained structures are given.

  16. Generalized bracket formulation of constrained dynamics in phase space.

    Science.gov (United States)

    Sergi, Alessandro

    2004-02-01

    A generalized bracket formalism is used to define the phase space flow of constrained systems. The generalized bracket naturally subsumes the approach to constrained dynamics given by Dirac some time ago. The dynamical invariant measure and the linear response of systems subjected to holonomic constraints are explicitly derived. In light of previous results, it is shown that generalized brackets provide a simple and unified view of the statistical mechanics of non-Hamiltonian phase space flows with a conserved energy.

  17. Kinetics for Reduction of Iron Ore Based on the Phase Space Reconstruction

    OpenAIRE

    Guo-Feng Fan; Li-Ling Peng; Wei-Chiang Hong; Fan Sun

    2014-01-01

    A series of smelting reduction experiments has been carried out with high-phosphorus iron ore of the different bases and heating rates by thermogravimetric analyzer. The derivative thermo gravimetric (DTG) data have been obtained from the experiments. After analyzing its phase space reconstruction, it is found that DTG phase portrait contains with a clear double “ $\\infty $ ” attractor characteristic by one-order delay. The statistical properties of the attractor inside and outside the double...

  18. Homogeneous and isotropic calorimetry for space experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mori, N., E-mail: mori@fi.infn.it [INFN sezione di Firenze, via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Adriani, O. [INFN sezione di Firenze, via B. Rossi 1, 50019 Sesto Fiorentino (Italy); University of Florence, Department of Physics and Astronomy, via G. Sansone 1, 50019 Sesto Fiorentino (Italy); Basti, A. [INFN sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Bigongiari, G. [University of Siena, Department of Physics, Earth and Environmental Sciences, Via Laterina 8, 53100 Siena (Italy); Bonechi, L. [INFN sezione di Firenze, via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Bonechi, S. [INFN sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); University of Siena, Department of Physics, Earth and Environmental Sciences, Via Laterina 8, 53100 Siena (Italy); Bongi, M. [INFN sezione di Firenze, via B. Rossi 1, 50019 Sesto Fiorentino (Italy); University of Florence, Department of Physics and Astronomy, via G. Sansone 1, 50019 Sesto Fiorentino (Italy); Bottai, S. [INFN sezione di Firenze, via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Brogi, P. [INFN sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); University of Siena, Department of Physics, Earth and Environmental Sciences, Via Laterina 8, 53100 Siena (Italy); D' Alessandro, R. [INFN sezione di Firenze, via B. Rossi 1, 50019 Sesto Fiorentino (Italy); University of Florence, Department of Physics and Astronomy, via G. Sansone 1, 50019 Sesto Fiorentino (Italy); Detti, S.; Lenzi, P. [INFN sezione di Firenze, via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Maestro, P.; Marrocchesi, P.S. [INFN sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); University of Siena, Department of Physics, Earth and Environmental Sciences, Via Laterina 8, 53100 Siena (Italy); Papini, P. [INFN sezione di Firenze, via B. Rossi 1, 50019 Sesto Fiorentino (Italy); and others

    2013-12-21

    Calorimetry plays an essential role in experiments observing high energy gamma and cosmic rays in space. The observational capabilities are mainly limited by the geometrical dimensions and the mass of the calorimeter. Since deployable mass depends on the design of the detector and the total mass of the payload, it is important to optimize the geometrical acceptance of the calorimeter for rare events, its granularity for particle identification, and its absorption depth for the measurement of the particle energy. A design of a calorimeter that could simultaneously optimize these characteristics assuming a mass limit of about 1.6 t has been studied. As a result, a homogeneous calorimeter instrumented with cesium iodide (CsI) crystals was chosen as the best compromise given the total mass constraint. The most suitable geometry found is cubic and isotropic, so as to detect particles arriving from every direction in space, thus maximizing the acceptance; granularity is obtained by filling the cubic volume with small cubic CsI crystals. The total radiation length in any direction is very large, and allows for optimal electromagnetic particle identification and energy measurement, while the interaction length is at least sufficient to allow a precise reconstruction of hadronic showers. Optimal values for the size of the crystals and spacing among them have been studied. Two prototypes have been constructed and preliminary tests with high energy ion and muon beams are reported.

  19. Evolution of classical projected phase space density in billiards

    Indian Academy of Sciences (India)

    Abstract. The classical phase space density projected on to the configuration space offers a means of comparing classical and quantum evolution. In this alternate approach that we adopt here, we show that for billiards, the eigenfunctions of the coarse-grained projected classical evolution operator are identical to a first ...

  20. Para-Galilean versus Galilean Noncommutative Phase spaces

    OpenAIRE

    Ngendakumana, Ancille; Nzotungicimpaye, Joachim; Todjihounde, Leonard

    2012-01-01

    The present paper deals with the construction of noncommutative phase spaces as coadjoint orbits of noncentral extensions of Galilei and Para-Galilei groups in two-dimensional space. The noncommutativity is due to the presence of a dual magnetic field B* in the Galilei case and of a magnetic field B in the Para-Galilei case.

  1. Elementary particles and emergent phase space

    CERN Document Server

    Zenczykowski, Piotr

    2014-01-01

    The Standard Model of elementary particles, although very successful, contains various elements that are put in by hand. Understanding their origin requires going beyond the model and searching for ""new physics"". The present book elaborates on one particular proposal concerning such physics. While the original conception is 50 years old, it has not lost its appeal over time. Its basic idea is that space - an arena of events treated in the Standard Model as a classical background - is a concept which emerges from a strictly discrete quantum layer in the limit of large quantum numbers. This bo

  2. The diffusion of stars through phase space

    Science.gov (United States)

    Binney, James; Lacey, Cedric

    1988-01-01

    An orbit-averaged Fokker-Planck equation has been derived to study the secular evolution of stellar systems with regular orbits and the heating of stellar disks. It is shown that a population of stars with an initially Maxwellian peculiar-velocity distribution will remain Maxwellian as it diffuses through orbit space only if: (1) a second-order diffusion tensor is proportional to epicycle energy; and (2) the population's velocity dispersion grows as the square root of time. Scattering by ephemeral spiral waves is able to account for the observed kinematics of the solar neighborhood only if the waves have wavelengths in excess of 9 kpc and constantly drifting pattern speeds.

  3. Space Storm as a Dynamical Phase Transition

    Science.gov (United States)

    Wanliss, J. A.

    2006-12-01

    Fluctuations of the DST index were analyzed for several magnetic storms preceded by more than a week of extremely quiet conditions to establish that there is a rapid and unidirectional change in the Hurst scaling exponent at the time of storm onset. That is, the transition is accompanied by the specific signature of a rapid unidirectional change in the temporal fractal scaling of fluctuations in DST, signaling the formation of a new dynamical phase (or mode) which is considerably more organized than the background state. We compare these results to a model of multifractional Brownian motion and suggest that the relatively sudden change from a less correlated to a more correlated pattern of multiscale fluctuations at storm onset can be characterized in terms of nonequilibrium dynamical phase transitions. Initial results show that a dynamical transition in solar wind VBs is correlated with the storm onset for intense storms, suggesting that the transition observed in DST is of external solar wind origin, rather than internal magnetospheric origin. On the other hand, some results show a dynamical transition in solar wind scaling exponents not matched in DST. As well, we also present results for small storms where there is a strong dynamical transition in DST without a similar changes in the VBs scaling statistics. The results for small storms seem to reduce the importance of the solar wind fluctuations but the evidence for the intense storms seems to point to the solar wind as being responsible for providing the scale free properties in the DST fluctuations.

  4. Controlling quantum interference in phase space with amplitude.

    Science.gov (United States)

    Xue, Yinghong; Li, Tingyu; Kasai, Katsuyuki; Okada-Shudo, Yoshiko; Watanabe, Masayoshi; Zhang, Yun

    2017-05-23

    We experimentally show a quantum interference in phase space by interrogating photon number probabilities (n = 2, 3, and 4) of a displaced squeezed state, which is generated by an optical parametric amplifier and whose displacement is controlled by amplitude of injected coherent light. It is found that the probabilities exhibit oscillations of interference effect depending upon the amplitude of the controlling light field. This phenomenon is attributed to quantum interference in phase space and indicates the capability of controlling quantum interference using amplitude. This remarkably contrasts with the oscillations of interference effects being usually controlled by relative phase in classical optics.

  5. In-step Two-phase Flow (TPF) Thermal Control Experiment

    Science.gov (United States)

    1992-01-01

    The Two-Phase Flow Thermal Control Experiment is part of the NASA/OAST In-Space Technology Experiments (In-STEP) Program. The experiment is configured for the Hitchhiker Shuttle payload system and consists of a capillary pumped loop, heatpipe radiator, and two-phase flow heat exchanger. The flight experiment design approach, test plan, payload design, and test components are described in outline and graphic form.

  6. Phase-space representation and polarization domains of random electromagnetic fields.

    Science.gov (United States)

    Castaneda, Roman; Betancur, Rafael; Herrera, Jorge; Carrasquilla, Juan

    2008-08-01

    The phase-space representation of stationary random electromagnetic fields is developed by using electromagnetic spatial coherence wavelets. The propagation of the field's power and states of spatial coherence and polarization results from correlations between the components of the field vectors at pairs of points in space. Polarization domains are theoretically predicted as the structure of the field polarization at the observation plane. In addition, the phase-space representation provides a generalization of the Poynting theorem. Theoretical predictions are examined by numerically simulating the Young experiment with electromagnetic waves. The experimental implementation of these results is a current subject of research.

  7. Kinematic variables in noncommutative phase space and parameters of noncommutativity

    Science.gov (United States)

    Gnatenko, Kh. P.

    2017-10-01

    We consider a space with noncommutativity of coordinates and noncommutativity of momenta. It is shown that coordinates in noncommutative phase space depend on mass therefore they cannot be considered as kinematic variables. Also, noncommutative momenta are not proportional to a mass as it has to be. We find conditions on the parameters of noncommutativity on which these problems are solved. It is important that on the same conditions the properties of kinetic energy are preserved, the motion of the center-of-mass of composite system and relative motion are independent, the trajectory of a particle (composite system) is independent of its mass and composition therefore the weak equivalence principle is recovered in four-dimensional (2D configurational space and 2D momentum space) noncommutative phase space.

  8. Zeeman deceleration beyond periodic phase space stability

    Science.gov (United States)

    Toscano, Jutta; Tauschinsky, Atreju; Dulitz, Katrin; Rennick, Christopher J.; Heazlewood, Brianna R.; Softley, Timothy P.

    2017-08-01

    In Zeeman deceleration, time-varying spatially inhomogeneous magnetic fields are used to create packets of translationally cold, quantum-state-selected paramagnetic particles with a tuneable forward velocity, which are ideal for cold reaction dynamics studies. Here, the covariance matrix adaptation evolutionary strategy is adopted in order to optimise deceleration switching sequences for the operation of a Zeeman decelerator. Using the optimised sequences, a 40% increase in the number of decelerated particles is observed compared to standard sequences for the same final velocity, imposing the same experimental boundary conditions. Furthermore, we demonstrate that it is possible to remove up to 98% of the initial kinetic energy of particles in the incoming beam, compared to the removal of a maximum of 83% of kinetic energy with standard sequences. Three-dimensional particle trajectory simulations are employed to reproduce the experimental results and to investigate differences in the deceleration mechanism adopted by standard and optimised sequences. It is experimentally verified that the optimal solution uncovered by the evolutionary algorithm is not merely a local optimisation of the experimental parameters—it is a novel mode of operation that goes beyond the standard periodic phase stability approach typically adopted.

  9. A General Purpose Experiment Controller for low cost Space Application

    Science.gov (United States)

    Guzman-Garcia, D.; Rowland, D. E.; Uribe, P.; Nieves-Chinchilla, T.

    2012-12-01

    Space activities are very expensive and include a high degree of risk. Nowadays, CubeSat missions represent a fast and inexpensive way to conduct scientific space research. These platforms are less expensive to develop and build than conventional satellites. There are ample demonstration that these platforms are well suited for a wide range of science missions in different fields, such as astrobiology, astronomy, atmospheric science, space weather and biology. This paper presents a hybrid "processor in an Field Programmable Gate Array (FPGA)" experiment/spacecraft controller for Cubesat missions. The system has two objectives, first is to obtain a multipurpose and easily customizable system aimed at processing the data from the widest kind of instruments and second, to provide the system with the highest processing capabilities in order to be able to perform complex onboard algorithms. Due to the versatility of the system and its reduced dimensions, it can be employed in different space platforms. The system is envisioned to be employed for the first time as the smart radio receiver for the upcoming NASA FireStation instrument. It is one of four experiments manifested to fly on an experiment pallet the U.S Department of Defense plans to deploy on the International Space Station in 2013. FireStation will continue analyzing the link between the Lightning and the Terrestrial Gamma Rays initiated by the FireFly Cubesat. The system is responsible for the management of a set of small Heliophysics instrumentats, including a photometer, magnetometer, and electric and magnetic field antennas. A description of the system architecture and its main features are presented. The main functional and performance tests during the integration and calibration phase of the instruments are also discussed.

  10. Phase-space evolution of x-ray coherence in phase-sensitive imaging.

    Science.gov (United States)

    Wu, Xizeng; Liu, Hong

    2008-08-01

    X-ray coherence evolution in the imaging process plays a key role for x-ray phase-sensitive imaging. In this work we present a phase-space formulation for the phase-sensitive imaging. The theory is reformulated in terms of the cross-spectral density and associated Wigner distribution. The phase-space formulation enables an explicit and quantitative account of partial coherence effects on phase-sensitive imaging. The presented formulas for x-ray spectral density at the detector can be used for performing accurate phase retrieval and optimizing the phase-contrast visibility. The concept of phase-space shearing length derived from this phase-space formulation clarifies the spatial coherence requirement for phase-sensitive imaging with incoherent sources. The theory has been applied to x-ray Talbot interferometric imaging as well. The peak coherence condition derived reveals new insights into three-grating-based Talbot-interferometric imaging and gratings-based x-ray dark-field imaging.

  11. The Phase Space Elementary Cell in Classical and Generalized Statistics

    Directory of Open Access Journals (Sweden)

    Piero Quarati

    2013-10-01

    Full Text Available In the past, the phase-space elementary cell of a non-quantized system was set equal to the third power of the Planck constant; in fact, it is not a necessary assumption. We discuss how the phase space volume, the number of states and the elementary-cell volume of a system of non-interacting N particles, changes when an interaction is switched on and the system becomes or evolves to a system of correlated non-Boltzmann particles and derives the appropriate expressions. Even if we assume that nowadays the volume of the elementary cell is equal to the cube of the Planck constant, h3, at least for quantum systems, we show that there is a correspondence between different values of h in the past, with important and, in principle, measurable cosmological and astrophysical consequences, and systems with an effective smaller (or even larger phase-space volume described by non-extensive generalized statistics.

  12. Quantum mechanics on phase space and the Coulomb potential

    Science.gov (United States)

    Campos, P.; Martins, M. G. R.; Vianna, J. D. M.

    2017-04-01

    Symplectic quantum mechanics (SMQ) makes possible to derive the Wigner function without the use of the Liouville-von Neumann equation. In this formulation of the quantum theory the Galilei Lie algebra is constructed using the Weyl (or star) product with Q ˆ = q ⋆ = q +iħ/2∂p , P ˆ = p ⋆ = p -iħ/2∂q, and the Schrödinger equation is rewritten in phase space; in consequence physical applications involving the Coulomb potential present some specific difficulties. Within this context, in order to treat the Schrödinger equation in phase space, a procedure based on the Levi-Civita (or Bohlin) transformation is presented and applied to two-dimensional (2D) hydrogen atom. Amplitudes of probability in phase space and the correspondent Wigner quasi-distribution functions are derived and discussed.

  13. Johnson Space Center Flight Medicine Clinic Experience

    Science.gov (United States)

    Landry, Trela

    2006-01-01

    Being a member of the Flight Medicine Clinic (FMC) Staff is a great experience. I joined the FMC staff 2 years ago when I became part of the Kelsey-Seybold team. The FMC staff consists of Flight Surgeons, Family Clinic Physician, Nursing staff, Wellness Coordinator and Support staff. We serve as the Primary Care Physicians for the astronauts and their families and provide annual physicals for the retired astronauts. We have approximately 800 patients in the FMC. As the Family Clinic Physician, I care for the astronaut spouses and children and provide annual physicals for the retired astronauts. Since we have a small patient population, we have the opportunity to spend increased personal time with our patients, which I enjoy. We have a pretty healthy patient population, who are very interested in their overall health and preventive care. In preparation for a shuttle launch, our nursing staff assists the flight surgeons with the astronaut physical exams, which occur 10 days prior to launch and again 3 days after their return. We also provide Primary Contact physicals for the families and guests, who will be in close contact with shuttle crew members. During these physicals, we provide education, emphasizing the importance of preventing the spread of communicable diseases to shuttle crew members. Being a part of the Space Medicine Program is an honor. To know that you contribute in some way to our nation s Space Program is very special. (This article was prepared by Dr. Trela Landry, M.D. for inclusion in a Kelsey-Seybold newsletter on 25 OCT 2006.)

  14. Grassmann phase space methods for fermions. II. Field theory

    Energy Technology Data Exchange (ETDEWEB)

    Dalton, B.J., E-mail: bdalton@swin.edu.au [Centre for Quantum and Optical Science, Swinburne University of Technology, Melbourne, Victoria 3122 (Australia); Jeffers, J. [Department of Physics, University of Strathclyde, Glasgow G4ONG (United Kingdom); Barnett, S.M. [School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

    2017-02-15

    In both quantum optics and cold atom physics, the behaviour of bosonic photons and atoms is often treated using phase space methods, where mode annihilation and creation operators are represented by c-number phase space variables, with the density operator equivalent to a distribution function of these variables. The anti-commutation rules for fermion annihilation, creation operators suggests the possibility of using anti-commuting Grassmann variables to represent these operators. However, in spite of the seminal work by Cahill and Glauber and a few applications, the use of Grassmann phase space methods in quantum-atom optics to treat fermionic systems is rather rare, though fermion coherent states using Grassmann variables are widely used in particle physics. This paper presents a phase space theory for fermion systems based on distribution functionals, which replace the density operator and involve Grassmann fields representing anti-commuting fermion field annihilation, creation operators. It is an extension of a previous phase space theory paper for fermions (Paper I) based on separate modes, in which the density operator is replaced by a distribution function depending on Grassmann phase space variables which represent the mode annihilation and creation operators. This further development of the theory is important for the situation when large numbers of fermions are involved, resulting in too many modes to treat separately. Here Grassmann fields, distribution functionals, functional Fokker–Planck equations and Ito stochastic field equations are involved. Typical applications to a trapped Fermi gas of interacting spin 1/2 fermionic atoms and to multi-component Fermi gases with non-zero range interactions are presented, showing that the Ito stochastic field equations are local in these cases. For the spin 1/2 case we also show how simple solutions can be obtained both for the untrapped case and for an optical lattice trapping potential.

  15. Relativistic Hydrogen-Like Atom on a Noncommutative Phase Space

    Science.gov (United States)

    Masum, Huseyin; Dulat, Sayipjamal; Tohti, Mutallip

    2017-09-01

    The energy levels of hydrogen-like atom on a noncommutative phase space were studied in the framework of relativistic quantum mechanics. The leading order corrections to energy levels 2 S 1/2, 2 P 1/2 and 2 P 3/2 were obtained by using the 𝜃 and the \\bar θ modified Dirac Hamiltonian of hydrogen-like atom on a noncommutative phase space. The degeneracy of the energy levels 2 P 1/2 and 2 P 3/2 were removed completely by 𝜃-correction. And the \\bar θ -correction shifts these energy levels.

  16. Phase space flows for non-Hamiltonian systems with constraints.

    Science.gov (United States)

    Sergi, Alessandro

    2005-09-01

    In this paper, non-Hamiltonian systems with holonomic constraints are treated by a generalization of Dirac's formalism. Non-Hamiltonian phase space flows can be described by generalized antisymmetric brackets or by general Liouville operators which cannot be derived from brackets. Both situations are treated. In the first case, a Nosé-Dirac bracket is introduced as an example. In the second one, Dirac's recipe for projecting out constrained variables from time translation operators is generalized and then applied to non-Hamiltonian linear response. Dirac's formalism avoids spurious terms in the response function of constrained systems. However, corrections coming from phase space measure must be considered for general perturbations.

  17. Evaluating the robustness of the enantioselective stationary phases on the Rosetta mission against space vacuum vaporization

    Science.gov (United States)

    Meierhenrich, Uwe J.; Cason, Julie R. L.; Szopa, Cyril; Sternberg, Robert; Raulin, François; Thiemann, Wolfram H.-P.; Goesmann, Fred

    2013-12-01

    The European Space Agency's Rosetta mission was launched in March 2004 in order to reach comet 67P/Churyumov-Gerasimenko by August 2014. The Cometary Sampling and Composition experiment (COSAC) onboard the Rosetta mission's lander "Philae" has been designed for the cometary in situ detection and quantification of organic molecules using gas chromatography coupled to mass spectrometry (GC-MS). The GC unit of COSAC is equipped with eight capillary columns that will each provide a specific stationary phase for molecular separation. Three of these stationary phases will be used to chromatographically resolve enantiomers, as they are composed of liquid polymers of polydimethylsiloxane (PDMS) to which chiral valine or cyclodextrin units are attached. Throughout the ten years of Rosetta's journey through space to reach comet 67P, these liquid stationary phases have been exposed to space vacuum, as the capillary columns within the COSAC unit were not sealed or filled with carrier gas. Long term exposures to space vacuum can cause damage to such liquid stationary phases as key monomers, volatiles, and chiral selectors can be vaporized and lost in transit. We have therefore exposed identical spare units of COSAC's chiral stationary phases over eight years to vacuum conditions mimicking those experienced in space and we have now investigated their resolution capabilities towards different enantiomers both before and after exposure to space vacuum environments. We have observed that enantiomeric resolution capabilities of these chiral liquid enantioselective stationary phases has not been affected by exposure to space vacuum conditions. Thus we conclude that the three chiral stationary phases of the COSAC experiment onboard the Rosetta mission lander "Philae" can be considered to have maintained their resolution capacities throughout their journey prior to cometary landing in November 2014.

  18. Simulation of PKL III G3.1(MSLB) experiment for verification of SPACE code

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chang Keun; Kim, Yo han; Ha, Sang Jun [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    The Korea nuclear industry has developed a best estimated two phase three field thermal hydraulic analysis code, SPACE (Safety and Performance Analysis Code for Nuclear Power Plants), for safety analysis and design of a PWR (Pressurized Water Reactor). As the first phase, the demo version of the SPACE code was released in March 2010. The code has been verified and improved according to the Verification and Validation (V and V) matrix prepared for the SPACE code as the second phase of the development. In this study, PKL III G3.1 experiment has been simulated using the SPACE code as one aspect of the V and V work. The results from this experiment were compared with tests of the SPACE and MARS codes.

  19. Gravitational redshift space-probe experiment

    Science.gov (United States)

    Vessot, R. F. C.; Levine, M. W.

    1979-01-01

    A Scout D rocket was launched from Wallops Island, Virginia, carrying an atomic hydrogen maser oscillator system as the payload. The frequency of signals from the oscillator was monitored on the ground at Merritt Island, Florida, by using two hydrogen masers as comparison oscillators. The first-order Doppler shift in the signals was eliminated by a go-return transponder link to the payload, and the resulting data, representing the relativistic shifts, were recovered and recorded. The objective was to measure directly the effect of gravitational potential on the frequency of an atomic hydrogen maser assuming it to be a 'proper' clock. A gravitational effect amounting to some 4.5 parts in 10 to the 10th power was measured with an oscillator having a stability better than 1 part in 10 to the 14th power. Therefore, to make the best possible use of the oscillator, all frequency shifts at the 2 to 5 X 10 to the -15 power level in delta f/f in the system must be accounted for. This includes all the phase variations that can cause such a shift to appear. The experiment, the data available and the manner in which they were processed, and the results are described.

  20. Trans-Pacific HDR Satellite Communications Experiment Phase-2 Project Plan and Experimental Network

    Science.gov (United States)

    Hsu, Eddie; Kadowaki, Naoto; Yoshimura, Naoko; Takahashi, Takashi; Yoshikawa, Makoto; Bergman, Larry; Bhasin, Kul

    2000-01-01

    The trans-Pacific high data rate (TP-HDR) satellite communications experiment was proposed at the Japan-U.S. Cooperation in Space (JUCS) Program Workshop held in Hawaii in 1993 and remote high definition video post-production was demonstrated as the first phase trial. ATM-based 45 Mbps trans-Pacific link was established in the first phase, and the following experiments with 155 Mbps was planned as the phase 2. This paper describes the experimental network configuration and project plan of TP-HDR experiment phase 2. Additional information is provided in the original.

  1. Simple procedure for phase-space measurement and entanglement validation

    Science.gov (United States)

    Rundle, R. P.; Mills, P. W.; Tilma, Todd; Samson, J. H.; Everitt, M. J.

    2017-08-01

    It has recently been shown that it is possible to represent the complete quantum state of any system as a phase-space quasiprobability distribution (Wigner function) [Phys. Rev. Lett. 117, 180401 (2016), 10.1103/PhysRevLett.117.180401]. Such functions take the form of expectation values of an observable that has a direct analogy to displaced parity operators. In this work we give a procedure for the measurement of the Wigner function that should be applicable to any quantum system. We have applied our procedure to IBM's Quantum Experience five-qubit quantum processor to demonstrate that we can measure and generate the Wigner functions of two different Bell states as well as the five-qubit Greenberger-Horne-Zeilinger state. Because Wigner functions for spin systems are not unique, we define, compare, and contrast two distinct examples. We show how the use of these Wigner functions leads to an optimal method for quantum state analysis especially in the situation where specific characteristic features are of particular interest (such as for spin Schrödinger cat states). Furthermore we show that this analysis leads to straightforward, and potentially very efficient, entanglement test and state characterization methods.

  2. Designing the Orbital Space Tourism Experience

    Science.gov (United States)

    Webber, Derek

    2006-01-01

    Sub-orbital space tourism is now well on its way to becoming a reality, with offerings by Virgin Galactic, Rocketplane, and others soon to be made available. Orbital space tourism is harder to achieve, but, if successful as a business model, will make significant contributions towards improved operational efficiencies, reusability, reliability and economies of scale to the world of crewed space flight. Some responses to the President's Vision for Space Exploration have included public space travel in low Earth orbit as sustaining and enabling elements of the vision in a post-Shuttle space architecture. This paper addresses the steps necessary to make possible such a US-based orbital space tourism business, and will assist commercial and government agencies concerned with the development of this new sector.

  3. Naval Space Surveillance Center uses of time, frequency, and phase

    Science.gov (United States)

    Hayden, Carroll C.; Knowles, Stephen H.

    1992-01-01

    The Naval Space Surveillance Center (NAVSPASUR) is an operational naval command that has the mission of determining the location of all manmade objects in space and transmitting information on objects of interest to the fleet. NAVSPASUR operates a 217 MHz radar fence that has 9 transmitting and receiving stations deployed in a line across southern Continental United States (CONUS). This surveillance fence provides unalerted detection of satellites overflying CONUS. NAVSPASUR also maintains a space catalog of all orbiting space objects. NAVSPASUR plays an important role as operational alternate to the primary national Space Surveillance Center (SSC) and Space Defence Operations Center (SPADOC). In executing these responsibilities, NAVSPASUR needs precise and/or standardized time and frequency in a number of applications. These include maintenance of the radar fence references to specification, and coordination with other commands and agencies for data receipt and dissemination. Precise time and frequency must be maintained within each site to enable proper operation of the interferometry phasing technique used. Precise time-of-day clocking must exist between sites for proper intersite coordination. Phase may be considered a derivative of time and frequency. Its control within each transmitter or receiver site is of great importance to NAVSPASUR because of the operation of the sensor as an interferometer system, with source direction angles as the primary observable. Determination of the angular position of a satellite is directly dependent on the accuracy with which the differential phase between spaced subarrays can be measured at each receiver site. Various aspects of the NAVSPASUR are discussed with respect to time, frequency, and phase.

  4. Phase Change Material Heat Sink for an ISS Flight Experiment

    Science.gov (United States)

    Quinn, Gregory; Stieber, Jesse; Sheth, Rubik; Ahlstrom, Thomas

    2015-01-01

    A flight experiment is being constructed to utilize the persistent microgravity environment of the International Space Station (ISS) to prove out operation of a microgravity compatible phase change material (PCM) heat sink. A PCM heat sink can help to reduce the overall mass and volume of future exploration spacecraft thermal control systems (TCS). The program is characterizing a new PCM heat sink that incorporates a novel phase management approach to prevent high pressures and structural deformation that often occur with PCM heat sinks undergoing cyclic operation in microgravity. The PCM unit was made using brazed aluminum construction with paraffin wax as the fusible material. It is designed to be installed into a propylene glycol and water cooling loop, with scaling consistent with the conceptual designs for the Orion Multipurpose Crew Vehicle. This paper reports on the construction of the PCM heat sink and on initial ground test results conducted at UTC Aerospace Systems prior to delivery to NASA. The prototype will be tested later on the ground and in orbit via a self-contained experiment package developed by NASA Johnson Space Center to operate in an ISS EXPRESS rack.

  5. Combined experiment Phase 2 data characterization

    Energy Technology Data Exchange (ETDEWEB)

    Miller, M.S.; Shipley, D.E.; Young, T.S.; Robinson, M.C.; Luttges, M.W. [Colorado Univ., Boulder, CO (United States); Simms, D.A. [National Renewable Energy Lab., Golden, CO (United States)

    1995-11-01

    The National Renewable Energy Laboratory`s ``Combined Experiment`` has yielded a large quantity of experimental data on the operation of a downwind horizontal axis wind turbine under field conditions. To fully utilize this valuable resource and identify particular episodes of interest, a number of databases were created that characterize individual data events and rotational cycles over a wide range of parameters. Each of the 59 five-minute data episodes collected during Phase 11 of the Combined Experiment have been characterized by the mean, minimum, maximum, and standard deviation of all data channels, except the blade surface pressures. Inflow condition, aerodynamic force coefficient, and minimum leading edge pressure coefficient databases have also been established, characterizing each of nearly 21,000 blade rotational cycles. In addition, a number of tools have been developed for searching these databases for particular episodes of interest. Due to their extensive size, only a portion of the episode characterization databases are included in an appendix, and examples of the cycle characterization databases are given. The search tools are discussed and the FORTRAN or C code for each is included in appendices.

  6. Lidar In-Space Technology Experiment (LITE) L1

    Data.gov (United States)

    National Aeronautics and Space Administration — LITE_L1 data are LIDAR Vertical profile data along the orbital flight path of STS-64.Lidar In-Space Technology Experiment (LITE) used a three-wavelength (355 nm, 532...

  7. An Asymmetrical Space Vector Method for Single Phase Induction Motor

    DEFF Research Database (Denmark)

    Cui, Yuanhai; Blaabjerg, Frede; Andersen, Gert Karmisholt

    2002-01-01

    the motor torque performance is not good enough. This paper addresses a new control method, an asymmetrical space vector method with PWM modulation, also a three-phase inverter is used for the main winding and the auxiliary winding. This method with PWM modulation is implemented to control the motor speed...

  8. Quantum Theory of Reactive Scattering in Phase Space

    NARCIS (Netherlands)

    Goussev, A.; Schubert, R.; Waalkens, H.; Wiggins, S.; Nicolaides, CA; Brandas, E

    2010-01-01

    We review recent results on quantum reactive scattering from a phase space perspective. The approach uses classical and quantum versions of Poincare-Birkhoff normal form theory and the perspective of dynamical systems theory. Over the past 10 years the classical normal form theory has provided a

  9. Geometrical Series and Phase Space in a Finite Oscillatory Motion

    Science.gov (United States)

    Mareco, H. R. Olmedo

    2006-01-01

    This article discusses some interesting physical properties of oscillatory motion of a particle on two joined inclined planes. The geometrical series demonstrates that the particle will oscillate during a finite time. Another detail is the converging path to the origin of the phase space. Due to its simplicity, this motion may be used as a…

  10. Phase-space treatment of the driven quantum harmonic oscillator

    Indian Academy of Sciences (India)

    A recent phase-space formulation of quantum mechanics in terms of the Glauber coherent states is applied to study the interaction of a one-dimensional harmonic oscillator with an arbitrary time-dependent force. Wave functions of the simultaneous values of position q and momentum p are deduced, which in turn give the ...

  11. q-Path entropy phenomenology for phase-space curves

    Science.gov (United States)

    Zamora, D. J.; Rocca, M. C.; Plastino, A.; Ferri, G. L.

    2018-01-01

    We describe the phenomenology of the classical q-path entropy of a phase-space curve. This allows one to disclose an entropic force-like mechanism that is able to mimic some phenomenological aspects of the strong force, such as confinement, hard core, and asymptotic freedom.

  12. Trigonometry of the quantum state space, geometric phases and relative phases

    CERN Document Server

    Ortega, R

    2003-01-01

    A complete set of invariants for three states in the quantum space of states P is obtained together with a complete set of relationships linking them. This is done in a way that preserves the self-duality of P and leads to a clear geometric description of invariants (distances, lateral phases; Hermitian angles, angular phases; and two purely triangular phases). Some of these invariants appear here for the first time. Symplectic area (and hence the triangle geometric phase) is proportional to a 'mixed phase excess', thus extending to P the relation 'area-angular excess' in the real sphere. The new triangle lateral phases provide a description, intrinsic to P, of relative phases in a superposition. This approach also provides closed expressions for the triangle holonomy associated with the usual Fubini-Study metric in P, as well as many other expressions for similar 'loop' operators along the triangle, including closed and exact expressions for the triangle Aharonov-Anandan geometric phase.

  13. Quantum Potential and Symmetries in Extended Phase Space

    Directory of Open Access Journals (Sweden)

    Sadollah Nasiri

    2006-06-01

    Full Text Available The behavior of the quantum potential is studied for a particle in a linear and a harmonic potential by means of an extended phase space technique. This is done by obtaining an expression for the quantum potential in momentum space representation followed by the generalization of this concept to extended phase space. It is shown that there exists an extended canonical transformation that removes the expression for the quantum potential in the dynamical equation. The situation, mathematically, is similar to disappearance of the centrifugal potential in going from the spherical to the Cartesian coordinates that changes the physical potential to an effective one. The representation where the quantum potential disappears and the modified Hamilton-Jacobi equation reduces to the familiar classical form, is one in which the dynamical equation turns out to be the Wigner equation.

  14. Driven phase space vortices in plasmas with nonextensive velocity distribution

    Science.gov (United States)

    Trivedi, Pallavi; Ganesh, Rajaraman

    2017-03-01

    The evolution of chirp-driven electrostatic waves in unmagnetized plasmas is numerically investigated by using a one-dimensional (1D) Vlasov-poisson solver with periodic boundary conditions. The initial velocity distribution of the 1D plasma is assumed to be governed by nonextensive q distribution [C. Tsallis, J. Stat. Phys. 52, 479 (1988)]. For an infinitesimal amplitude of an external drive, we investigate the effects of chirp driven dynamics that leads to the formation of giant phase space vortices (PSV) for both Maxwellian (q = 1) and non-Maxwellian ( q ≠ 1 ) plasmas. For non-Maxwellian plasmas, the formation of giant PSV with multiple extrema and phase velocities is shown to be dependent on the strength of "q". Novel features such as "shark"-like and transient "honeycomb"-like structures in phase space are discussed. Wherever relevant, we compare our results with previous work.

  15. Presence Experiences - the eventalisation of urban space

    DEFF Research Database (Denmark)

    Pløger, John

    2010-01-01

    ’ and Hans Martin Gumbrecht on ‘presence-events’, I focus on subcultural and subpolitical groups trying to capture urban commercial spaces and to reverse or reveal their symbolic meaning. Using the oppositional youth group Pirate Parties, I argue that it is exactly the eventalisation and the presence quality......Cultural events are, as part of an urban development strategy, about (symbolic) representations, but for the human beings participating in the event it may include acts of in/visibility (anonymity versus expressivity) and different articulations of meaning or subjectivity in space. A particular...... and virtual qualities of presence-event spaces and the eventalisation of urban space...

  16. Emittance and Phase Space Tomography for the Fermilab Linac

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, F.G.G.; Johnstone, C.; Kobilarcik, T.; Koizumi, G.M.; Moore, C.D.; /Fermilab; Newhart, D.L.; /Fermilab

    2012-05-01

    The Fermilab Linac delivers a variable intensity, 400-MeV beam to the MuCool Test Area experimental hall via a beam line specifically designed to facilitate measurements of the Linac beam emittance and properties. A 10 m, dispersion-free and magnet-free straight utilizes an upstream quadrupole focusing triplet in combination with the necessary in-straight beam diagnostics to fully characterize the transverse beam properties. Since the Linac does not produce a strictly elliptical phase space, tomography must be performed on the profile data to retrieve the actual particle distribution in phase space. This is achieved by rotating the phase space distribution using different waist focusing conditions of the upstream triplet and performing a deconvolution of the profile data. Preliminary measurements using this diagnostic section are reported here. These data represent a first-pass measurement of the Linac emittance based on various techniques. It is clear that the most accurate representation of the emittance is given by the 3-profile approach. Future work will entail minimizing the beam spot size on MW5 to test and possibly improve the accuracy of the 2-profile approach. The 95% emittance is {approx} 18{pi} in the vertical and {approx} 13{pi} in the horizontal, which is especially larger than anticipated - 8-10{pi} was expected. One possible explanation is that the entire Linac pulse is extracted into the MTA beamline and during the first few microseconds, the feed forward and RF regulation are not stable. This may result in a larger net emittance observed versus beam injected into Booster, where the leading part of the Linac beam pulse is chopped. Future studies will clearly entail a measurement of the emittance vs. pulse length. One additional concern is that the Linac phase space is most likely aperture-defined and non-elliptical in nature. A non-elliptical phase-space determination would require a more elaborate analysis and provide another explanation of the

  17. Experiments and Simulations with Space Charge Dominated Beams

    Science.gov (United States)

    Kishek, Rami A.

    2002-11-01

    Applications such as heavy ion inertial fusion, spallation neutron sources, high energy colliders, and free electron lasers, require high brightness that boosts the intensity beyond traditional limits. Beams of interest for such applications begin life as space-charge dominated beams, and should ideally remain so for most of their lives. In practice, undesirably high emittance at the source or emittance growth during acceleration and transport disturb this condition, and the beam becomes emittance dominated. Space charge-induced instabilities, emittance growth and halo formation are limiting factors that need to be understood in order to maintain the beam quality while transporting a higher current. At the University of Maryland we have a number of experiments that use low-energy, high-intensity electron beams to model such accelerators at low cost. The University of Maryland Electron Ring (UMER), currently under construction, has been designed to operate with an extreme space charge tune shift that can also be adjusted to span the entire range down to existing rings. The 10-keV, 100 mA, UMER beam has a generalized perveance in the range of 0.0015, and a tune depression (k/ko) as low as 0.2. With hundreds of magnets and a vast arsenal of diagnostics, the 3.6 m-diameter ring is a complex and flexible machine. Since UMER is designed to serve as an accelerator for research in beam physics, beam experiments are conducted hand-in-hand with the phased installation of UMER segments, in order to provide a wealthy basis of beam data for future experiments. This talk presents some of the experimental results obtained during the phased-installation of UMER. Computer simulation results using various codes, particularly self-consistent models of the space charge effects using the WARP code, are used to enhance our understanding of the experimental results. An overview is presented of a number of significant (and sometimes mysterious) issues. These include detailed and time

  18. Phase-space Dynamics of Runaway Electrons In Tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Xiaoyin Guan, Hong Qin, and Nathaniel J. Fisch

    2010-08-31

    The phase-space dynamics of runaway electrons is studied, including the influence of loop voltage, radiation damping, and collisions. A theoretical model and a numerical algorithm for the runaway dynamics in phase space are developed. Instead of standard integrators, such as the Runge-Kutta method, a variational symplectic integrator is applied to simulate the long-term dynamics of a runaway electron. The variational symplectic integrator is able to globally bound the numerical error for arbitrary number of time-steps, and thus accurately track the runaway trajectory in phase space. Simulation results show that the circulating orbits of runaway electrons drift outward toward the wall, which is consistent with experimental observations. The physics of the outward drift is analyzed. It is found that the outward drift is caused by the imbalance between the increase of mechanical angular momentum and the input of toroidal angular momentum due to the parallel acceleration. An analytical expression of the outward drift velocity is derived. The knowledge of trajectory of runaway electrons in configuration space sheds light on how the electrons hit the first wall, and thus provides clues for possible remedies.

  19. New science from the phase space of old stellar systems

    Science.gov (United States)

    Varri, Anna Lisa; Breen, Philip G.; Heggie, Douglas C.; Tiongco, Maria; Vesperini, Enrico

    2017-06-01

    Our traditional interpretative picture of the internal dynamics of globular clusters has been recently revolutionized by a series of discoveries about their chemical, structural, and kinematic properties. The empirical evidence that their velocity space is much more complex than usually expected encourages us to use them as refreshingly novel phase space laboratories for some long-forgotten aspects of collisional gravitational dynamics. Such a realization, coupled with the discovery that the stars in clusters were not all born at once in a single population, makes them new, challenging chemodynamical puzzles.Thanks to the proper motions of thousands of stars that will be available from the Gaia mission, we are about to enter a new ''golden age'' for the study of the dynamics of this class of stellar systems, as the full phase space of several Galactic globular clusters will be soon unlocked for the first time. In this context, I will present the highlights of a more realistic dynamical paradigm for these intriguing stellar systems, with emphasis on the role of angular momentum, velocity anisotropy and external tidal field. Such a fundamental understanding of the emerging phase space complexity of globulars will allow us to address many open questions about their rich dynamical evolution, their elusive stellar populations and putative black holes, and their role within the history of our Galaxy.

  20. LOFT L9-3 ATWS Experiment Simulation using the SPACE Code

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chang Keun; Lee, Dong Hyuk; Kim, Yo Han; Ha, Sang Jun [KEPCO Research Institute, Daejeon (Korea, Republic of); Hong, Sung Yull [bYeungnam University, Gyeongsan (Korea, Republic of)

    2011-05-15

    The Korea nuclear industry has developed a best estimated two-phase three-filed thermal-hydraulic analysis code, SPACE(Safety and Performance Analysis Code for Nuclear Power Plants), for safety analysis and design of a PWR(Pressurized Water Reactor). As the first phase, the demo version of SPACE code was released on March, 2010. And the code has been verified and improved according to the Validation and Verification (V and V) matrix prepared for the SPACE code as the second phase of the development. In this study, the LOFT (Loss Of Fluid Test) L9-3 Anticipated Transient Without Scram (ATWS) experiment has been simulated using the SPACE code as one of the V and V work. The results were compared with those of the experiment and other code simulation

  1. NASDA aquatic animal experiment facilities for space shuttle and ISS

    Science.gov (United States)

    Uchida, Satoko; Masukawa, Mitsuyo; Kamigaichi, Shigeki

    National Space Development Agency of Japan (NASDA) has developed aquatic animal experiment facilities for NASA Space Shuttle use. Vestibular Function Experiment Unit (VFEU) was firstly designed and developed for physiological research using carp in Spacelab-J (SL-J, STS-47) mission. It was modified as Aquatic Animal Experiment Unit (AAEU) to accommodate small aquatic animals, such as medaka and newt, for second International Microgravity Laboratory (IML-2, STS-65) mission. Then, VFEU was improved to accommodate marine fish and to perform neurobiological experiment for Neurolab (STS-90) and STS-95 missions. We have also developed and used water purification system which was adapted to each facility. Based on these experiences of Space Shuttle missions, we are studying to develop advanced aquatic animal experiment facility for both Space Shuttle and International Space Station (ISS).

  2. Laser Interferometer Space Antenna (LISA) Far Field Phase Pattern

    Science.gov (United States)

    Waluschka, Eugene

    1999-01-01

    The Laser Interferometry Space Antenna (LISA) for the detection of Gravitational Waves is a very long baseline interferometer that will measure the changes in the distance of a five million kilometer arm to pico meter accuracies. Knowledge of the phase deviations from a spherical wave and what causes these deviations are needed considerations in (as a minimum) the design of the telescope and in determining pointing requirements. Here we present the far field phase deviations from a spherical wave for given Zernike aberrations and obscurations of the exit pupil.

  3. Physics of Colloids in Space: Microgravity Experiment Launched, Installed, and Activated on the International Space Station

    Science.gov (United States)

    Doherty, Michael P.

    2002-01-01

    The Physics of Colloids in Space (PCS) experiment is a Microgravity Fluids Physics investigation that is presently located in an Expedite the Process of Experiments to Space Station (EXPRESS) Rack on the International Space Station. PCS was launched to the International Space Station on April 19, 2001, activated on May 31, 2001, and will continue to operate about 90 hr per week through May 2002.

  4. Probabilistic phase space trajectory description for anomalous polymer dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Panja, Debabrata [Institute for Theoretical Physics, Universiteit van Amsterdam, Science Park 904, Postbus 94485, 1090 GL Amsterdam (Netherlands)

    2011-03-16

    It has been recently shown that the phase space trajectories for the anomalous dynamics of a tagged monomer of a polymer-for single polymeric systems and phenomena such as phantom Rouse, self-avoiding Rouse, and Zimm ones, reptation, and translocation through a narrow pore in a membrane, as well as for many polymeric systems such as polymer melts in the entangled regime-are robustly described by the generalized Langevin equation. Here I show that the probability distribution of phase space trajectories for all of these classical anomalous dynamics for single polymers is that of a fractional Brownian motion (fBm), while the dynamics for polymer melts between the entangled regime and the eventual diffusive regime exhibits small but systematic deviations from that of a fBm.

  5. Identifying phase-space boundaries with Voronoi tessellations

    Energy Technology Data Exchange (ETDEWEB)

    Debnath, Dipsikha; Matchev, Konstantin T. [University of Florida, Physics Department, Gainesville, FL (United States); Gainer, James S. [University of Hawaii, Department of Physics and Astronomy, Honolulu, HI (United States); Kilic, Can; Yang, Yuan-Pao [The University of Texas at Austin, Theory Group, Department of Physics and Texas Cosmology Center, Austin, TX (United States); Kim, Doojin [University of Florida, Physics Department, Gainesville, FL (United States); CERN, Theory Division, Geneva 23 (Switzerland)

    2016-11-15

    Determining the masses of new physics particles appearing in decay chains is an important and longstanding problem in high energy phenomenology. Recently it has been shown that these mass measurements can be improved by utilizing the boundary of the allowed region in the fully differentiable phase space in its full dimensionality. Here we show that the practical challenge of identifying this boundary can be solved using techniques based on the geometric properties of the cells resulting from Voronoi tessellations of the relevant data. The robust detection of such phase-space boundaries in the data could also be used to corroborate a new physics discovery based on a cut-and-count analysis. (orig.)

  6. The Phase Space Formulation of Time-Symmetric Quantum Mechanics

    Directory of Open Access Journals (Sweden)

    Charlyne de Gosson

    2015-11-01

    Full Text Available Time-symmetric quantum mechanics can be described in the Weyl–Wigner–Moyal phase space formalism by using the properties of the cross-terms appearing in the Wigner distribution of a sum of states. These properties show the appearance of a strongly oscillating interference between the pre-selected and post-selected states. It is interesting to note that the knowledge of this interference term is sufficient to reconstruct both states. Quanta 2015; 4: 27–34.

  7. On the calculation of soft phase space integral

    OpenAIRE

    Zhu, Hua

    2014-01-01

    The recent discovery of the Higgs boson at the LHC attracts much attention to the precise calculation of its production cross section in quantum chromodynamics. In this work, we discuss the calculation of soft triple-emission phase space integral, which is an essential ingredient in the recently calculated soft-virtual corrections to Higgs boson production at next-to-next-to-next-to-leading order. The main techniques used this calculation are method of differential equation for Feynman integr...

  8. A simple algorithm for longitudinal phase space tomography

    CERN Document Server

    Hancock, S

    1997-01-01

    Tomography is now a very broad topic with a wealth of different algorithms for the reconstruction of both qualitative and quantitative images. One of the simplest algorithms has been modified to take into account the non-linearity of large-amplitude synchrotron motion. This permits the accurate reconstruction of longitudinal phase space density from one-dimensional bunch profile data. The method may be further extended to treat, for example, multi-harmonic systems and self-fields.

  9. Torus as phase space: Weyl quantization, dequantization, and Wigner formalism

    Energy Technology Data Exchange (ETDEWEB)

    Ligabò, Marilena, E-mail: marilena.ligabo@uniba.it [Dipartimento di Matematica, Università di Bari, I-70125 Bari (Italy)

    2016-08-15

    The Weyl quantization of classical observables on the torus (as phase space) without regularity assumptions is explicitly computed. The equivalence class of symbols yielding the same Weyl operator is characterized. The Heisenberg equation for the dynamics of general quantum observables is written through the Moyal brackets on the torus and the support of the Wigner transform is characterized. Finally, a dequantization procedure is introduced that applies, for instance, to the Pauli matrices. As a result we obtain the corresponding classical symbols.

  10. Zonal-flow dynamics from a phase-space perspective

    Science.gov (United States)

    Ruiz, D. E.; Parker, J. B.; Shi, E. L.; Dodin, I. Y.

    2017-10-01

    The wave kinetic equation (WKE) describing drift-wave (DW) turbulence is widely used in the studies of zonal flows (ZFs) emerging from DW turbulence. However, this formulation neglects the exchange of enstrophy between DWs and ZFs and also ignores effects beyond the geometrical-optics (GO) limit. Here we present a new theory that captures both of these effects, while still treating DW quanta (``driftons'') as particles in phase space. In this theory, the drifton dynamics is described by an equation of the Wigner-Moyal type, which is analogous to the phase-space formulation of quantum mechanics. The ``Hamiltonian'' and the ``dissipative'' parts of the DW-ZF interactions are clearly identified. Moreover, this theory can be interpreted as a phase-space representation of the second-order cumulant expansion (CE2). In the GO limit, this formulation features additional terms missing in the traditional WKE that ensure conservation of the total enstrophy of the system, in addition to the total energy, which is the only conserved invariant in previous theories based on the traditional WKE. Numerical simulations are presented to illustrate the importance of these additional terms. Supported by the U.S. DOE through Contract Nos. DE-AC02-09CH11466 and DE-AC52-07NA27344, by the NNSA SSAA Program through DOE Research Grant No. DE-NA0002948, and by the U.S. DOD NDSEG Fellowship through Contract No. 32-CFR-168a.

  11. Prediction of Tropical Rainfall by Local Phase Space Reconstruction.

    Science.gov (United States)

    Waelbroeck, H.; López-Pea, R.; Morales, T.; Zertuche, F.

    1994-11-01

    The authors propose a weather prediction model based on a local reconstruction of the dynamics in phase space, using an 11-year dataset from Tlaxcala, Mexico. A vector in phase space corresponds to T consecutive days of data; the best predictions are found for T = 14. The prediction for the next day, x0 fL(x0), is based on a local reconstruction of the dynamical map f in an ball centered at x0. The high dimensionality of the phase space implies a large optimal value of , so that the number of points in an ball is sufficient to reconstruct the local map. The local approximation fL f is therefore not very good and the prediction skill drops off quickly at first, with a timescale of 2 days. On the other hand, the authors find useful skill in the prediction of 10-day rainfall accumulations, which reflects the persistence of weather patterns. The mean-squared error in the prediction of the rainfall anomaly for the year 1992 was 64% of the variance, and the early beginning of the rain season was correctly predicted.

  12. Multifractal spectrum of phase space related to generalized thermostatistics

    Science.gov (United States)

    Olemskoi, A. I.; Kharchenko, V. O.; Borisyuk, V. N.

    2008-03-01

    We consider a self-similar phase space with specific fractal dimension d being distributed with spectrum function f(d) . Related thermostatistics is shown to be governed by the Tsallis formalism of the non-extensive statistics, where the non-additivity parameter equals to τ ¯ (q) ≡ 1 / τ(q) > 1, and the multifractal function τ(q) = qdq - f(dq) is the specific heat determined with multifractal parameter q ∈ [ 1 , ∞ ] . At that, the equipartition law is shown to take place. Optimization of the multifractal spectrum function f(d) arrives at the relation between the statistical weight and the system complexity. It is shown that the statistical weight exponent τ(q) can be modeled by hyperbolic tangent deformed in accordance with both Tsallis and Kaniadakis exponential functions to describe arbitrary multifractal phase space explicitly. The spectrum function f(d) is proved to increase monotonically from minimum value f = - 1 at d = 0 to maximum one f = 1 at d = 1. At the same time, the number of monofractals increases with the growth of the phase-space volume at small dimensions d and falls down in the limit d → 1.

  13. Phase camera experiment for Advanced Virgo

    NARCIS (Netherlands)

    Agatsuma, Kazuhiro; Van Beuzekom, Martin; Van Der Schaaf, Laura; Van Den Brand, Jo

    2016-01-01

    We report on a study of the phase camera, which is a frequency selective wave-front sensor of a laser beam. This sensor is utilized for monitoring sidebands produced by phase modulations in a gravitational wave (GW) detector. Regarding the operation of the GW detectors, the laser

  14. Criteria for evaluating experiments on crop production in space

    Science.gov (United States)

    Berry, W. L.; Koontz, H.; Wheeler, R.; Prince, R.

    1989-01-01

    Consideration is given to the development of criteria for successful CELSS experiments on crop production in space. Also, the development of a standard procedure to produce a given expected yield is examined. Factors influencing the success of CELSS experiments are discussed, including environmental limits to growth, efficient use of resources, data collection sensitivity, stress, and the space in which the experiment is performed. The implications of the study for designing CELSS food production systems are noted.

  15. Grassmann phase space methods for fermions. I. Mode theory

    Science.gov (United States)

    Dalton, B. J.; Jeffers, J.; Barnett, S. M.

    2016-07-01

    In both quantum optics and cold atom physics, the behaviour of bosonic photons and atoms is often treated using phase space methods, where mode annihilation and creation operators are represented by c-number phase space variables, with the density operator equivalent to a distribution function of these variables. The anti-commutation rules for fermion annihilation, creation operators suggest the possibility of using anti-commuting Grassmann variables to represent these operators. However, in spite of the seminal work by Cahill and Glauber and a few applications, the use of Grassmann phase space methods in quantum-atom optics to treat fermionic systems is rather rare, though fermion coherent states using Grassmann variables are widely used in particle physics. The theory of Grassmann phase space methods for fermions based on separate modes is developed, showing how the distribution function is defined and used to determine quantum correlation functions, Fock state populations and coherences via Grassmann phase space integrals, how the Fokker-Planck equations are obtained and then converted into equivalent Ito equations for stochastic Grassmann variables. The fermion distribution function is an even Grassmann function, and is unique. The number of c-number Wiener increments involved is 2n2, if there are n modes. The situation is somewhat different to the bosonic c-number case where only 2 n Wiener increments are involved, the sign of the drift term in the Ito equation is reversed and the diffusion matrix in the Fokker-Planck equation is anti-symmetric rather than symmetric. The un-normalised B distribution is of particular importance for determining Fock state populations and coherences, and as pointed out by Plimak, Collett and Olsen, the drift vector in its Fokker-Planck equation only depends linearly on the Grassmann variables. Using this key feature we show how the Ito stochastic equations can be solved numerically for finite times in terms of c-number stochastic

  16. The Information Science Experiment System - The computer for science experiments in space

    Science.gov (United States)

    Foudriat, Edwin C.; Husson, Charles

    1989-01-01

    The concept of the Information Science Experiment System (ISES), potential experiments, and system requirements are reviewed. The ISES is conceived as a computer resource in space whose aim is to assist computer, earth, and space science experiments, to develop and demonstrate new information processing concepts, and to provide an experiment base for developing new information technology for use in space systems. The discussion covers system hardware and architecture, operating system software, the user interface, and the ground communication link.

  17. SpaceHab 1 maintenance experiment

    Science.gov (United States)

    Bohannon, Jackie W.

    1994-01-01

    The SpaceHab 1 flight on STS-57 served as a test platform for evaluation of two space station payloads. The first payload evaluated a space station maintenance concept using a sweep signal generator and a 48-channel logic analyzer to perform fault detection and isolation. Crew procedures files, test setup diagram files, and software to configure the test equipment were created on the ground and uplinked on the astronauts' voice communication circuit to perform tests in flight. In order to use these files, the portable computer was operated in a multi-window configuration. The test data transmitted to the ground allowing the ground staff to identify the cause of the fault and provide the crew with the repair procedures and diagrams. The crew successfully repaired the system under test. The second payload investigated hand soldering and de-soldering of standard components on printed circuit (PC) boards in zero gravity. It also used a new type of intra-vehicular foot restraints which uses the neutral body posture in zero-g to provide retention of the crew without their conscious attention.

  18. Momentum-space cigar geometry in topological phases

    Science.gov (United States)

    Palumbo, Giandomenico

    2018-01-01

    In this paper, we stress the importance of momentum-space geometry in the understanding of two-dimensional topological phases of matter. We focus, for simplicity, on the gapped boundary of three-dimensional topological insulators in class AII, which are described by a massive Dirac Hamiltonian and characterized by an half-integer Chern number. The gap is induced by introducing a magnetic perturbation, such as an external Zeeman field or a ferromagnet on the surface. The quantum Bures metric acquires a central role in our discussion and identifies a cigar geometry. We first derive the Chern number from the cigar geometry and we then show that the quantum metric can be seen as a solution of two-dimensional non-Abelian BF theory in momentum space. The gauge connection for this model is associated to the Maxwell algebra, which takes into account the Lorentz symmetries related to the Dirac theory and the momentum-space magnetic translations connected to the magnetic perturbation. The Witten black-hole metric is a solution of this gauge theory and coincides with the Bures metric. This allows us to calculate the corresponding momentum-space entanglement entropy that surprisingly carries information about the real-space conformal field theory describing the defect lines that can be created on the gapped boundary.

  19. Simulated response of top-hat electrostatic analysers - importance of phase-space resolution

    Science.gov (United States)

    De Marco, Rossana; Bruno, Roberto; D'Amicis, Raffaella; Federica Marcucci, Maria; Servidio, Sergio; Valentini, Francesco

    2016-04-01

    We use a numerical code able to reproduce the angular/energy response of a typical electrostatic analyzer of top-hat type starting from velocity distribution functions (VDFs) generated by numerical imulations.The simulations are based on the Hybrid Vlasov-Maxwell (HVM) numerical algorithm which integrates the Vlasov equation for the ion distribution function in multi-dimensional geometry in phase space, while the electrons are treated as a fluid. Virtual satellites launched through the simulation box measure the particle VDFs. Such VDFs are interpolated into a spacecraft reference frame and moved from the simulation Cartesian grid to energy-angular coordinates to mimic the response of a real electrostatic sensor in the solar wind and in the magnetosheath for different conditions. We discuss the results of this study with respect to the importance of phase-space resolution for a space plasma experiment meant to investigate kinetic plasma regime.

  20. Laser ignition application in a space experiment

    Science.gov (United States)

    Liou, Larry C.; Culley, Dennis E.

    1993-01-01

    A laser ignition system is proposed for the Combustion Experiment Module on an orbiting spacecraft. The results of a design study are given using the scheduled 'Flame Ball Experiment' as the design guidelines. Three laser ignition mechanisms and wavelengths are evaluated. A prototype laser is chosen and its specifications are given, followed by consideration of the beam optical arrangement, the ignition power requirement, the laser ignition system weight, size, reliability, and laser cooling and power consumption. Electromagnetic interference to the onboard electronics caused by the laser ignition process is discussed. Finally, ground tests are suggested.

  1. Linearization of the longitudinal phase space without higher harmonic field

    Directory of Open Access Journals (Sweden)

    Benno Zeitler

    2015-12-01

    Full Text Available Accelerator applications like free-electron lasers, time-resolved electron diffraction, and advanced accelerator concepts like plasma acceleration desire bunches of ever shorter longitudinal extent. However, apart from space charge repulsion, the internal bunch structure and its development along the beam line can limit the achievable compression due to nonlinear phase space correlations. In order to improve such a limited longitudinal focus, a correction by properly linearizing the phase space is required. At large scale facilities like Flash at Desy or the European Xfel, a higher harmonic cavity is installed for this purpose. In this paper, another method is described and evaluated: Expanding the beam after the electron source enables a higher order correction of the longitudinal focus by a subsequent accelerating cavity which is operated at the same frequency as the electron gun. The elaboration of this idea presented here is based on a ballistic bunching scheme, but can be extended to bunch compression based on magnetic chicanes. The core of this article is an analytic model describing this approach, which is verified by simulations, predicting possible bunch length below 1 fs at low bunch charge. Minimizing the energy spread down to σ_{E}/E<10^{-5} while keeping the bunch long is another interesting possibility, which finds applications, e.g., in time resolved transmission electron microscopy concepts.

  2. The dependence of cirrus gamma size distributions expressed as volumes in N0-λ-μ phase space and bulk cloud properties on environmental conditions: Results from the Small Ice Particles in Cirrus Experiment (SPARTICUS)

    Science.gov (United States)

    Jackson, Robert C.; McFarquhar, Greg M.; Fridlind, Ann M.; Atlas, Rachel

    2015-10-01

    The variability of cirrus ice microphysical properties is investigated using observations obtained during the Small Particles in Cirrus (SPARTICUS) campaign. An existing approach that represents a size distribution (SD) as a single gamma function using an ellipsoid of equally realizable solutions in (N0, λ, μ) phase space is modified to automatically identify multiple modes in SDs and characterize each mode by such an ellipsoid. The modified approach is applied to ice crystals with maximum dimension D > 15 µm collected by the 2-D stereo and 2-D precipitation probes on the Stratton Park Engineering Company Learjet. The dependencies of N0, μ, and λ from each mode, total number concentration, bulk extinction, ice water content (IWC), and mass median maximum dimension Dmm as a function of temperature T and cirrus type are then analyzed. The changes in the observed codependencies between N0, μ, and λ, bulk extinction, IWC, and Dmm with environmental conditions indicate that particles were larger at higher T during SPARTICUS. At most two modes were observed in any SD during SPARTICUS, with the average boundary between them at 115 µm, similar to past studies not using probes with shatter mitigating tips and artifact removal algorithms. The bimodality of the SDs increased with T. This and the differences in N0, μ, and λ between the modes suggest that particles with smaller D nucleated more recently than particles with larger D, which grew via vapor deposition and aggregation. Because smaller crystals, whose concentrations are uncertain, make marginal contributions to higher order moments, the use of higher moments for evaluating model fields is suggested.

  3. The Dependence of Cirrus Gamma Size Distributions Expressed as Volumes in N(sub 0)-Lambda-Mu Phase Space and Bulk Cloud Properties on Environmental Conditions: Results from the Small Ice Particles in Cirrus Experiment (SPARTICUS)

    Science.gov (United States)

    Jackson, Robert C.; McFarquhar, Greg M.; Fridlind, Ann M.; Atlas, Rachel

    2015-01-01

    The variability of cirrus ice microphysical properties is investigated using observations obtained during the Small Particles in Cirrus (SPARTICUS) campaign. An existing approach that represents a size distribution (SD) as a single gamma function using an ellipsoid of equally realizable solutions in (N(sub 0), lambda, mu) phase space is modified to automatically identify multiple modes in SDs and characterize each mode by such an ellipsoid. The modified approach is applied to ice crystals with maximum dimension D greater than15 micrometers collected by the 2-D stereo and 2-D precipitation probes on the Stratton Park Engineering Company Learjet. The dependencies of N(sub 0), mu, and lambda from each mode, total number concentration, bulk extinction, ice water content (IWC), and mass median maximum dimension D(sub mm) as a function of temperature T and cirrus type are then analyzed. The changes in the observed codependencies between N(sub 0), mu, and lambda, bulk extinction, IWC, and D(sub mm) with environmental conditions indicate that particles were larger at higher T during SPARTICUS. At most two modes were observed in any SD during SPARTICUS, with the average boundary between them at 115 micrometers, similar to past studies not using probes with shatter mitigating tips and artifact removal algorithms. The bimodality of the SDs increased with T. This and the differences in N(sub 0), mu, and lambda between the modes suggest that particles with smaller D nucleated more recently than particles with larger D, which grew via vapor deposition and aggregation. Because smaller crystals, whose concentrations are uncertain, make marginal contributions to higher order moments, the use of higher moments for evaluating model fields is suggested.

  4. Thermal control of the Lidar In-Space Technology Experiment

    Science.gov (United States)

    Carlson, Ann B.; Roettker, William A.

    1987-01-01

    The Lidar In-Space Technology Experiment (LITE) will employ lidar techniques to study the atmosphere from space. The LITE instrument will be flown in the Space Shuttle Payload Bay with an earth directed orientation. The experiment thermal control incorporates both active and passive techniques. The Laser Transmitter Module (LTM) and the system electronics will be actively cooled through the Shuttle pallet coolant loop. The receiver system and experiment platform will be passsively controlled through the use of insulation and component surface properties. This paper explains the thermal control techniques used and the analysis results, with primary focus on the receiver system.

  5. Simulation of ATLAS SGTR HL 04 experiment using SPACE code

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Hyuk; Ha, Sang Jun; Kim, Seyun [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    The Korean nuclear industry has been developing a thermal hydraulic analysis code for the safety analysis of PWRs(pressurized water reactors). The new code is named SPACE(Safety and Performance Analysis Code for Nuclear Power Plant). As a part of code validation effort, simulation of ATLAS SGTR(Steam Generator Tube Rupture) experiment using SPACE code has been performed. The SGTR HL 04 experiment is a single U tube SGTR. The calculated results using the SPACE code are compared with those from the experiment.

  6. The theory and application of space microbiology: China's experiences in space experiments and beyond.

    Science.gov (United States)

    Liu, Changting

    2017-02-01

    Microorganisms exhibit high adaptability to extreme environments of outer space via phenotypic and genetic changes. These changes may affect astronauts in the space environment as well as on Earth because mutant microbes will inevitably return with the spacecraft. However, the role and significance of these phenotypic changes and the underlying mechanisms are important unresolved questions in the field of space biology. By reviewing, especially the Chinese studies, we propose a space microbial molecular effect theory, that is, the space environment affects the nature of genes and the molecular structure of microorganisms to produce phenotypic changes. In this review, we discussed three basic theories for the research of space microbiology, including (1) space microbial pathogenicity and virulence mutations and the human mutualism theory; (2) space microbial drug-resistance mutations and metabolism associated with space pharmaceuticals theory; (3) space corrosion, microbial decontamination, and new materials technology theory. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  7. Experimental evidence of adiabatic splitting of charged particle beams using stable islands of transverse phase space

    CERN Document Server

    Gilardoni, S S; Martini, M; Métral, E; Steerenberg, R; Müller, A-S

    2006-01-01

    Recently, a novel technique to perform multi-turn extraction from a circular particle accelerator was proposed. It is based on beam splitting and trapping, induced by a slow crossing of a nonlinear resonance, inside stable islands of transverse phase space. Experiments at the CERN Proton Synchrotron started in 2002 and evidence of beam splitting was obtained by summer 2004. In this paper the measurement results achieved with both a low- and a high-intensity, single-bunch proton beam are presented.

  8. Performance Assessment in the PILOT Experiment On Board Space Stations Mir and ISS.

    Science.gov (United States)

    Johannes, Bernd; Salnitski, Vyacheslav; Dudukin, Alexander; Shevchenko, Lev; Bronnikov, Sergey

    2016-06-01

    The aim of this investigation into the performance and reliability of Russian cosmonauts in hand-controlled docking of a spacecraft on a space station (experiment PILOT) was to enhance overall mission safety and crew training efficiency. The preliminary findings on the Mir space station suggested that a break in docking training of about 90 d significantly degraded performance. Intensified experiment schedules on the International Space Station (ISS) have allowed for a monthly experiment using an on-board simulator. Therefore, instead of just three training tasks as on Mir, five training flights per session have been implemented on the ISS. This experiment was run in parallel but independently of the operational docking training the cosmonauts receive. First, performance was compared between the experiments on the two space stations by nonparametric testing. Performance differed significantly between space stations preflight, in flight, and postflight. Second, performance was analyzed by modeling the linear mixed effects of all variances (LME). The fixed factors space station, mission phases, training task numbers, and their interaction were analyzed. Cosmonauts were designated as a random factor. All fixed factors were found to be significant and the interaction between stations and mission phase was also significant. In summary, performance on the ISS was shown to be significantly improved, thus enhancing mission safety. Additional approaches to docking performance assessment and prognosis are presented and discussed.

  9. Overview of Materials International Space Station Experiment 7B

    Science.gov (United States)

    Jaworske, Donald A.; Siamidis, John

    2009-01-01

    Materials International Space Station Experiment 7B (MISSE 7B) is the most recent in a series of experiments flown on the exterior of International Space Station for the purpose of determining the durability of materials and components in the space environment. A collaborative effort among the Department of Defense, the National Aeronautics and Space Administration, industry, and academia, MISSE 7B will be flying a number of NASA experiments designed to gain knowledge in the area of space environmental effects to mitigate risk for exploration missions. Consisting of trays called Passive Experiment Containers, the suitcase sized payload opens on hinges and allows active and passive experiments contained within to be exposed to the ram and wake or zenith and nadir directions in low Earth orbit, in essence, providing a test bed for atomic oxygen exposure, ultraviolet radiation exposure, charged particle radiation exposure, and thermal cycling. New for MISSE 7B is the ability to monitor experiments actively, with data sent back to Earth via International Space Station communications. NASA?s active and passive experiments cover a range of interest for the Agency. Materials relevant to the Constellation Program include: solar array materials, seal materials, and thermal protection system materials. Materials relevant to the Exploration Technology Development Program include: fabrics for spacesuits, materials for lunar dust mitigation, and new thermal control coatings. Sensors and components on MISSE 7B include: atomic oxygen fluence monitors, ultraviolet radiation sensors, and electro-optical components. In addition, fundamental space environmental durability science experiments are being flown to gather atomic oxygen erosion data and thin film polymer mechanical and optical property data relevant to lunar lander insulation and the James Web Space Telescope. This paper will present an overview of the NASA experiments to be flown on MISSE 7B, along with a summary of the

  10. On-sky Testing of the Active Phasing Experiment

    Science.gov (United States)

    Gonté, Frédéric; Araujo, Constanza; Bourtembourg, Reynald; Brast, Roland; Derie, Frédéric; Duhoux, Philippe; Dupuy, Christophe; Frank, Christophe; Karban, Robert; Mazzoleni, Ruben; Noethe, Lothar; Sedghi, Babak; Surdej, Isabelle; Yaitskova, Natalia; Luong, Bruno; Chueca, Sergio; Reyes, Marcos; Esposito, Simone; Pinna, Enrico; Puglisi, Alfio; Quiros Pacheco, Fernando; Dohlen, Kjetil; Vigan, Arthur

    2009-06-01

    The Active Phasing Experiment (APE) has been used by ESO to gain experience in controlling segmented primary mirrors in preparation for the European Extremely Large Telescope. The experiment tested various phasing techniques and explored their advantages and limitations. Four optical phasing sensors were developed using different techniques — a curvature sensor, a pyramid sensor, a Shack-Hartmann sensor and a sensor based on a modified Mach-Zehnder interferometer. The design of the APE instrument is described. APE was installed at the VLT visitor focus for on-sky testing and a brief summary of the results of the experiment is given.

  11. Bound-preserving discontinuous Galerkin methods for conservative phase space advection in curvilinear coordinates

    Science.gov (United States)

    Endeve, Eirik; Hauck, Cory D.; Xing, Yulong; Mezzacappa, Anthony

    2015-04-01

    We extend the positivity-preserving method of Zhang and Shu [49] to simulate the advection of neutral particles in phase space using curvilinear coordinates. The ability to utilize these coordinates is important for non-equilibrium transport problems in general relativity and also in science and engineering applications with specific geometries. The method achieves high-order accuracy using Discontinuous Galerkin (DG) discretization of phase space and strong stability-preserving, Runge-Kutta (SSP-RK) time integration. Special care is taken to ensure that the method preserves strict bounds for the phase space distribution function f; i.e., f ∈ [ 0 , 1 ]. The combination of suitable CFL conditions and the use of the high-order limiter proposed in [49] is sufficient to ensure positivity of the distribution function. However, to ensure that the distribution function satisfies the upper bound, the discretization must, in addition, preserve the divergence-free property of the phase space flow. Proofs that highlight the necessary conditions are presented for general curvilinear coordinates, and the details of these conditions are worked out for some commonly used coordinate systems (i.e., spherical polar spatial coordinates in spherical symmetry and cylindrical spatial coordinates in axial symmetry, both with spherical momentum coordinates). Results from numerical experiments - including one example in spherical symmetry adopting the Schwarzschild metric - demonstrate that the method achieves high-order accuracy and that the distribution function satisfies the maximum principle.

  12. Bound-Preserving Discontinuous Galerkin Methods for Conservative Phase Space Advection in Curvilinear Coordinates

    Energy Technology Data Exchange (ETDEWEB)

    Mezzacappa, Anthony [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Endeve, Eirik [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hauck, Cory D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Xing, Yulong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-02-01

    We extend the positivity-preserving method of Zhang & Shu [49] to simulate the advection of neutral particles in phase space using curvilinear coordinates. The ability to utilize these coordinates is important for non-equilibrium transport problems in general relativity and also in science and engineering applications with specific geometries. The method achieves high-order accuracy using Discontinuous Galerkin (DG) discretization of phase space and strong stabilitypreserving, Runge-Kutta (SSP-RK) time integration. Special care in taken to ensure that the method preserves strict bounds for the phase space distribution function f; i.e., f ϵ [0, 1]. The combination of suitable CFL conditions and the use of the high-order limiter proposed in [49] is su cient to ensure positivity of the distribution function. However, to ensure that the distribution function satisfies the upper bound, the discretization must, in addition, preserve the divergencefree property of the phase space ow. Proofs that highlight the necessary conditions are presented for general curvilinear coordinates, and the details of these conditions are worked out for some commonly used coordinate systems (i.e., spherical polar spatial coordinates in spherical symmetry and cylindrical spatial coordinates in axial symmetry, both with spherical momentum coordinates). Results from numerical experiments - including one example in spherical symmetry adopting the Schwarzschild metric - demonstrate that the method achieves high-order accuracy and that the distribution function satisfies the maximum principle.

  13. Discrete phase-space approach to mutually orthogonal Latin squares

    Science.gov (United States)

    Gaeta, Mario; Di Matteo, Olivia; Klimov, Andrei B.; de Guise, Hubert

    2014-10-01

    We show there is a natural connection between Latin squares and commutative sets of monomials defining geometric structures in finite phase-space of prime power dimensions. A complete set of such monomials defines a mutually unbiased basis (MUB) and may be associated with a complete set of mutually orthogonal Latin squares (MOLS). We translate some possible operations on the monomial sets into isomorphisms of Latin squares, and find a general form of permutations that map between Latin squares corresponding to unitarily equivalent mutually unbiased sets.

  14. Demonstration of extended capture range for James Webb Space Telescope phase retrieval.

    Science.gov (United States)

    Carlisle, R Elizabeth; Acton, D Scott

    2015-07-20

    A geometrical phase retrieval (GPR) algorithm is applied to the problem of image stacking in order to extend the capture range of normal phase retrieval (PR) on the James Webb Space Telescope (JWST), and potentially eliminate a lengthy image-stacking process that is based on centroids. Computer simulations are used to establish the capture range of the existing PR algorithm for JWST and demonstrate that it is increased by more than a factor of 10 when combined with GPR, guaranteeing PR capture 95% of the time. An experiment using a scale optical model of JWST was conducted to demonstrate the effectiveness of the GPR algorithm in both coherent and incoherent imaging.

  15. Software Acquisition Best Practices: Experiences From the Space Systems Domain

    National Research Council Canada - National Science Library

    Adams, R

    2004-01-01

    This report describes a comprehensive set of software acquisition best practices that the Software Acquisition MOlE research team has identified based on their experience with numerous space programs over many years...

  16. AMS experiment takes off for Kennedy Space Center August 2010

    CERN Multimedia

    CERN Video Productions

    2010-01-01

    Geneva, 18 August 2010. The Alpha Magnetic Spectrometer (AMS), an experiment that will search for antimatter and dark matter in space, leaves CERN next Tuesday on the next leg of its journey to the International Space Station. The AMS detector is being transported from CERN to Geneva International Airport in preparation for its planned departure from Switzerland on 26 August, when it will be flown to the Kennedy Space Center in Florida on board a US Air Force Galaxy transport aircraft.

  17. Robotic servicing system for space material experiment

    Science.gov (United States)

    Yamawaki, Toshihiko; Shimoji, Haruhiko; Abe, Toshio

    1994-01-01

    A containerless image furnace with an electrostatic positioning device has been developed as one of the material experiment facilities on the Japanese experimental module (JEM). It is characterized by heating/melting/cooling the sample whose position is kept without any contacts by actively controlled electrostatic force exerted between the sample and a set of electrodes. The experiment using the image furnace requires various servicing operations. We have been developing a robotic servicing system with an internal robot accommodated in the rack as an alternative to the crew. It aims to reduce the load on the crew by automating regular tasks and to increase the flexibility applicable to simple irregular tasks by introducing a remote teleoperation scheme. The present robot has poor capability to replace the crew. In order to compensate it, introducing of the concept of the robot friendliness and improving the controllability of the teleoperation by the ground operator aids are essential. In this paper, we identify the tasks to be performed by the robotic servicing system and discuss the way to compensate the capability of the robot. In addition we describe the evaluation tests using an experimental model.

  18. Dynamical tunneling in systems with a mixed phase space

    Energy Technology Data Exchange (ETDEWEB)

    Loeck, Steffen

    2010-04-22

    Tunneling is one of the most prominent features of quantum mechanics. While the tunneling process in one-dimensional integrable systems is well understood, its quantitative prediction for systems with a mixed phase space is a long-standing open challenge. In such systems regions of regular and chaotic dynamics coexist in phase space, which are classically separated but quantum mechanically coupled by the process of dynamical tunneling. We derive a prediction of dynamical tunneling rates which describe the decay of states localized inside the regular region towards the so-called chaotic sea. This approach uses a fictitious integrable system which mimics the dynamics inside the regular domain and extends it into the chaotic region. Excellent agreement with numerical data is found for kicked systems, billiards, and optical microcavities, if nonlinear resonances are negligible. Semiclassically, however, such nonlinear resonance chains dominate the tunneling process. Hence, we combine our approach with an improved resonance-assisted tunneling theory and derive a unified prediction which is valid from the quantum to the semiclassical regime. We obtain results which show a drastically improved accuracy of several orders of magnitude compared to previous studies. (orig.)

  19. What is the phase space of the last glacial inception?

    Science.gov (United States)

    Bahadory, Taimaz; Tarasov, Lev

    2017-04-01

    Would the ice and climate pattern of glacial inception changed much with small tweaks to the initial Eemian climate state? Given the very limited available geological constraints, what is the range of potential spatio-temporal patterns of ice sheet inception and associated climate? What positive and negative feedbacks between ice, atmospheric and ocean circulation, and vegetation dominate glacial inception? As a step towards answering these questions, we examine the phase space of glacial inception in response to a subset of uncertainties in a coupled 3D model through an ensemble of simulations. The coupled model consists of the GSM (Glacial Systems Model) and LOVECLIM earth systems model of intermediate complexity. The former includes a 3D ice sheet model, asynchronously coupled glacio isostatic adjustment, surface drainage solver, and permafrost resolving bed thermal model. The latter includes an ocean GCM, atmospheric component, dynamic/thermodynamic seaice, and simplified dynamical vegetation. Our phase space exploration probes uncertainties in: initial conditions, downscaling and upscaling, the radiative effect of clouds, snow and ice albedo, precipitation parameterization, and freshwater discharge. The probe is constrained by model fit to present day climate and LGM climate.

  20. Laser Interferometer Space Antenna (LISA) Far Field Phase Patterns

    Science.gov (United States)

    Waluschka, Eugene; Obenschain, Arthur F. (Technical Monitor)

    2000-01-01

    The Laser Interferometer Space Antenna (LISA) consists of three spacecraft in orbit about the sun. The orbits are chosen such that the three spacecraft are always at (roughly) the vertices of a equilateral triangle with 5 million kilometer leg lengths. Even though the distances between the three spacecraft are 5 million kilometers, the expected phase shifts between any two beams, due to a gravitational wave, only correspond to a distance change of about 10 pico meters, which is about 10(exp -5) waves for a laser wavelength of 1064 nm. To obtain the best signal-to-noise ratio, noise sources such as changes in the apparent distances due to pointing jitter must be controlled carefully. This is the main reason for determining the far-field phase patterns of a LISA type telescope. Because of torque on the LISA spacecraft and other disturbances, continuous adjustments to the pointing of the telescopes are required. These pointing adjustments will be a "jitter" source. If the transmitted wave is perfectly spherical then rotations (Jitter) about its geometric center will not produce any effect at the receiving spacecraft. However, if the outgoing wave is not perfectly spherical, then pointing jitter will produce a phase variation at the receiving spacecraft. The following sections describe the "brute force" computational approach used to determine the scalar wave front as a function of exit pupil (Zernike) aberrations and to show the results (mostly graphically) of the computations. This approach is straightforward and produces believable phase variations to sub-pico meter accuracy over distances on the order of 5 million kilometers. As such this analyzes the far field phase sensitivity to exit pupil aberrations.

  1. Tomography of the electron beam transverse phase space at PITZ

    Energy Technology Data Exchange (ETDEWEB)

    Asova, Galina

    2013-09-15

    The operation of a Free Elector Laser, FEL, requires high energy, high peak current electron beams with small transverse emittance. In the contemporary FELs, the electron beam is passed through a periodic magnetic structure - an undulator - which modifies the straight beam trajectory into a sinusoidal one, where FEL light is generated at each bend. According to the energy, the transverse emittance and the peak current of the beam and the parameters of the undulator, FEL radiation with wavelength in the range of nano- to micrometers can be generated. Studies and development of FELs are done all over the world. The Free electron LASer in Hamburg, FLASH, and the international European X-ray FEL, XFEL, in Hamburg, Germany, are two leading projects of the Deutsches Elektronen SYnchrotron, DESY. Part of the research program on FELs in DESY is realized in Zeuthen within the project Photo-Injector Test Facility at DESY in Zeuthen, PITZ. PITZ is an international collaboration including Germany, Russia, Italy, France, Bulgaria, Thailand, United Kingdom. The Institute of Nuclear Research and Nuclear Energy, INRNE, at the Bulgarian Academy of Sciences participates from bulgarian side. PITZ studies and optimizes the photo-injectors for FLASH and the XFEL. The research program emphasizes on detailed measurements of the transverse phase-space density distribution. Until 2010 the single slit scan technique has been used to measure the beam transverse distributions. At the end of 2010 a module for tomographic diagnostics has been installed which extends the possibilities of PITZ to measure simultaneously the two transverse planes of a single micropulse with improved signal-to-noise ratio. The difficult conditions of low emittance for high bunch charge and low energy make the operation of the module challenging. This thesis presents the design considerations for the tomography module, a number of reconstruction algorithms and their applicability to limited data sets, the influence

  2. Linear ray and wave optics in phase space bridging ray and wave optics via the Wigner phase-space picture

    CERN Document Server

    Torre, Amalia

    2005-01-01

    Ray, wave and quantum concepts are central to diverse and seemingly incompatible models of light. Each model particularizes a specific ''manifestation'' of light, and then corresponds to adequate physical assumptions and formal approximations, whose domains of applicability are well-established. Accordingly each model comprises its own set of geometric and dynamic postulates with the pertinent mathematical means.At a basic level, the book is a complete introduction to the Wigner optics, which bridges between ray and wave optics, offering the optical phase space as the ambience and the Wigner f

  3. Application of high stability oscillators to radio science experiments using deep space probes

    Science.gov (United States)

    Kursinski, Emil R.

    1990-01-01

    The microwave telecommunication links between the earth and deep space probes have long been used to conduct radio science experiments which take advantage of the phase coherency and stability of these links. These experiments measure changes in the phase delay of the signals to infer electrical, magnetic and gravitational properties of the solar system environment and beyond through which the spacecraft and radio signals pass. The precision oscillators, from which the phase of the microwave signals are derived, play a key role in the stability of these links and therefore the sensitivity of these measurements. These experiments have become a driving force behind recent and future improvements in the Deep Space Network and spacecraft oscillators and frequency and time distribution systems. Three such experiments which are key to these improvements are briefly discussed and relationship between their sensitivity and the signal phase stability is described. The first is the remote sensing of planetary atmospheres by occultation in which the radio signal passes through the atmosphere and is refracted causing the signal pathlength to change from which the pressure and the temperature of the atmosphere can be derived. The second experiment is determination of the opacity of planetary rings by passage of the radio signals through the rings. The third experiment is the research for very low frequency gravitational radiation. The fractional frequency variation of the signal is comparable to the spatial strain amplitude the system is capable of detecting. A summary of past results and future possibilities for these experiments are presented.

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

    Science.gov (United States)

    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.

  5. Electric Field Double Probe Measurements for Ionospheric Space Plasma Experiments

    Science.gov (United States)

    Pfaff, R.

    1999-01-01

    Double probes represent a well-proven technique for gathering high quality DC and AC electric field measurements in a variety of space plasma regimes including the magnetosphere, ionosphere, and mesosphere. Such experiments have been successfully flown on a variety of spacecraft including sounding rockets and satellites. Typical instrument designs involve a series of trades, depending on the science objectives, type of platform (e.g., spinning or 3-axis stabilized), expected plasma regime where the measurements will be made, available telemetry, budget, etc. In general, ionospheric DC electric field instruments that achieve accuracies of 0.1 mV/m or better, place spherical sensors at large distances (10m or more) from the spacecraft body in order to extend well beyond the spacecraft wake and sheath and to achieve large signal-to-noise ratios for DC and long wavelength measurements. Additional sets of sensors inboard of the primary, outermost sensors provide useful additional information, both for diagnostics of the plasma contact potentials, which particularly enhance the DC electric field measurements on non-spinning spacecraft, and for wavelength and phase velocity measurements that use the spaced receiver or "interferometer" technique. Accurate attitude knowledge enables B times V contributions to be subtracted from the measured potentials, and permits the measured components to be rotated into meaningful geophysical reference frames. We review the measurement technique for both DC and wave electric field measurements in the ionosphere discussing recent advances involving high resolution burst memories, multiple baseline double probes, new sensor surface materials, biasing techniques, and other considerations.

  6. A space-time fractional phase-field model with tunable sharpness and decay behavior and its efficient numerical simulation

    Science.gov (United States)

    Li, Zheng; Wang, Hong; Yang, Danping

    2017-10-01

    We present a space-time fractional Allen-Cahn phase-field model that describes the transport of the fluid mixture of two immiscible fluid phases. The space and time fractional order parameters control the sharpness and the decay behavior of the interface via a seamless transition of the parameters. Although they are shown to provide more accurate description of anomalous diffusion processes and sharper interfaces than traditional integer-order phase-field models do, fractional models yield numerical methods with dense stiffness matrices. Consequently, the resulting numerical schemes have significantly increased computational work and memory requirement. We develop a lossless fast numerical method for the accurate and efficient numerical simulation of the space-time fractional phase-field model. Numerical experiments shows the utility of the fractional phase-field model and the corresponding fast numerical method.

  7. The TGV II Experiment (Phase I Results)

    Science.gov (United States)

    Beneš, P.; Briançon, Ch.; Brudanin, V. B.; Čermák, P.; Egorov, V. G.; Gusev, K. N.; Klimenko, A. A.; Kovalenko, V. E.; Kovalik, A.; Rukhadze, N. I.; Salamatin, A. V.; Šimkovic, F.; Štekl, I.; Timkin, V. V.; Vylov, Ts.

    2007-10-01

    The TGV II (Telescope Germanium Vertical) facility is a low background spectrometer operated in Modane Underground Laboratory. It aims at the study of double electron capture of 106Cd. The spectrometer is composed of 32 HPGe planar detectors interleaved with thin-foil samples made of Cd-106 enriched to 75% (total mass about 10 g). In 2006, the main run of phase I (1 year duration) was terminated yielding a new limit on half-life for two-neutrino double electron capture (g.s.→g.s.) in 106Cd as 2.0×1020 years. This limit is significantly higher (by almost three orders of magnitude) than those already published.

  8. Laboratory science with space data accessing and using space-experiment data

    CERN Document Server

    van Loon, Jack J W A; Zell, Martin; Beysens, Daniel

    2011-01-01

    For decades experiments conducted on space stations like MIR and the ISS have been gathering data in many fields of research in the natural sciences, medicine and engineering. The European Union-sponsored ULISSE project focused on exploring the wealth of unique experimental data provided by revealing raw and metadata from these studies via an Internet Portal. This book complements the portal. It serves as a handbook of space experiments and describes the various types of experimental infrastructure areas of research in the life and physical sciences and technology space missions that hosted scientific experiments the types and structures of the data produced and how one can access the data through ULISSE for further research. The book provides an overview of the wealth of space experiment data that can be used for additional research and will inspire academics (e.g. those looking for topics for their PhD thesis) and research departments in companies for their continued development.

  9. New Thermodynamical Force in Plasma Phase Space that Controls Turbulence and Turbulent Transport

    Science.gov (United States)

    Itoh, Sanae-I.; Itoh, Kimitaka

    2012-11-01

    Physics of turbulence and turbulent transport has been developed on the central dogma that spatial gradients constitute the controlling parameters, such as Reynolds number and Rayleigh number. Recent experiments with the nonequilibrium plasmas in magnetic confinement devices, however, have shown that the turbulence and transport change much faster than global parameters, after an abrupt change of heating power. Here we propose a theory of turbulence in inhomogeneous magnetized plasmas, showing that the heating power directly influences the turbulence. New mechanism, that an external source couples with plasma fluctuations in phase space so as to affect turbulence, is investigated. A new thermodynamical force in phase-space, i.e., the derivative of heating power by plasma pressure, plays the role of new control parameter, in addition to spatial gradients. Following the change of turbulence, turbulent transport is modified accordingly. The condition under which this new effect can be observed is also evaluated.

  10. The vocabulary of Learner-Space Interactions - Understanding learning spaces experience through the repertory grid method

    OpenAIRE

    Lallemand, Carine; Koenig, Vincent

    2017-01-01

    Higher education institutions are facing new educational challenges and are striving for an evolution in pedagogical practices. This evolution is accompanied by the need for innovative learning spaces to support students in the development of “21st century skills”. Designing these spaces requires a deep understanding of learners’ needs and experiences. User-centered design therefore appears as an adequate process to understand learning experiences in relation to spatial design. In this paper,...

  11. Gouy phase and visibility in the double-slit experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, C.J.S.; Marinho, L.S. [Departamento de Física, Universidade Federal do Piauí, Campus Ministro Petrônio Portela, CEP 64049-550, Teresina, PI (Brazil); Brazil, T.B. [Instituto de Física, Universidade de São Paulo, Caixa Postal 66318, 05315-970 São Paulo, SP (Brazil); Cabral, L.A. [Curso de Física, Universidade Federal do Tocantins, Caixa Postal 132, CEP 77804-970, Araguaína, TO (Brazil); Oliveira Jr, J.G.G. de [Departamento de Ciências Exatas e Tecnológicas, Universidade Estadual de Santa Cruz, Caixa Postal 45662-900, Ilhéus, BA (Brazil); Sampaio, M.D.R. [Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Caixa Postal 702, CEP 30161-970, Belo Horizonte, Minas Gerais (Brazil); Centre for Particle Theory CM310 Durham University - St. John’s College B6 (United States); Paz, I.G. da, E-mail: irismarpaz@ufpi.edu.br [Departamento de Física, Universidade Federal do Piauí, Campus Ministro Petrônio Portela, CEP 64049-550, Teresina, PI (Brazil)

    2015-11-15

    We study a matter wave double-slit experiment with unequal aperture widths in order to evaluate the effect of the Gouy phase on the visibility/predictability. While the predictability changes as one increases the width of one of the slits, the visibility receives a contribution from the Gouy phase at a specific point in the detection screen. Consequently such apparatus constitutes a simple device for measuring the Gouy phase of matter waves. We illustrate it numerically for neutrons.

  12. ORIGAMI: DELINEATING HALOS USING PHASE-SPACE FOLDS

    Energy Technology Data Exchange (ETDEWEB)

    Falck, Bridget L.; Neyrinck, Mark C.; Szalay, Alexander S. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)

    2012-08-01

    We present the ORIGAMI method of identifying structures, particularly halos, in cosmological N-body simulations. Structure formation can be thought of as the folding of an initially flat three-dimensional manifold in six-dimensional phase space. ORIGAMI finds the outer folds that delineate these structures. Halo particles are identified as those that have undergone shell-crossing along three orthogonal axes, providing a dynamical definition of halo regions that is independent of density. ORIGAMI also identifies other morphological structures: particles that have undergone shell-crossing along 2, 1, or 0 orthogonal axes correspond to filaments, walls, and voids, respectively. We compare this method to a standard friends-of-friends halo-finding algorithm and find that ORIGAMI halos are somewhat larger, more diffuse, and less spherical, though the global properties of ORIGAMI halos are in good agreement with other modern halo-finding algorithms.

  13. Aspects of phase-space noncommutative quantum mechanics

    Directory of Open Access Journals (Sweden)

    O. Bertolami

    2015-11-01

    Full Text Available In this work some issues in the context of Noncommutative Quantum Mechanics (NCQM are addressed. The main focus is on finding whether symmetries present in Quantum Mechanics still hold in the phase-space noncommutative version. In particular, the issues related with gauge invariance of the electromagnetic field and the weak equivalence principle (WEP in the context of the gravitational quantum well (GQW are considered. The question of the Lorentz symmetry and the associated dispersion relation is also examined. Constraints are set on the relevant noncommutative parameters so that gauge invariance and Lorentz invariance holds. In opposition, the WEP is verified to hold in the noncommutative setup, and it is only possible to observe a violation through an anisotropy of the noncommutative parameters.

  14. Wigner phase space distribution via classical adiabatic switching

    Energy Technology Data Exchange (ETDEWEB)

    Bose, Amartya [Department of Chemistry, University of Illinois, 600 S. Goodwin Avenue, Urbana, Illinois 61801 (United States); Makri, Nancy [Department of Chemistry, University of Illinois, 600 S. Goodwin Avenue, Urbana, Illinois 61801 (United States); Department of Physics, University of Illinois, 1110 W. Green Street, Urbana, Illinois 61801 (United States)

    2015-09-21

    Evaluation of the Wigner phase space density for systems of many degrees of freedom presents an extremely demanding task because of the oscillatory nature of the Fourier-type integral. We propose a simple and efficient, approximate procedure for generating the Wigner distribution that avoids the computational difficulties associated with the Wigner transform. Starting from a suitable zeroth-order Hamiltonian, for which the Wigner density is available (either analytically or numerically), the phase space distribution is propagated in time via classical trajectories, while the perturbation is gradually switched on. According to the classical adiabatic theorem, each trajectory maintains a constant action if the perturbation is switched on infinitely slowly. We show that the adiabatic switching procedure produces the exact Wigner density for harmonic oscillator eigenstates and also for eigenstates of anharmonic Hamiltonians within the Wentzel-Kramers-Brillouin (WKB) approximation. We generalize the approach to finite temperature by introducing a density rescaling factor that depends on the energy of each trajectory. Time-dependent properties are obtained simply by continuing the integration of each trajectory under the full target Hamiltonian. Further, by construction, the generated approximate Wigner distribution is invariant under classical propagation, and thus, thermodynamic properties are strictly preserved. Numerical tests on one-dimensional and dissipative systems indicate that the method produces results in very good agreement with those obtained by full quantum mechanical methods over a wide temperature range. The method is simple and efficient, as it requires no input besides the force fields required for classical trajectory integration, and is ideal for use in quasiclassical trajectory calculations.

  15. Generalizing the Boltzmann equation in complex phase space

    Science.gov (United States)

    Zadehgol, Abed

    2016-08-01

    In this work, a generalized form of the BGK-Boltzmann equation is proposed, where the velocity, position, and time can be represented by real or complex variables. The real representation leads to the conventional BGK-Boltzmann equation, which can recover the continuity and Navier-Stokes equations. We show that the complex representation yields a different set of equations, and it can also recover the conservation and Navier-Stokes equations, at low Mach numbers, provided that the imaginary component of the macroscopic mass can be neglected. We briefly review the Constant Speed Kinetic Model (CSKM), which was introduced in Zadehgol and Ashrafizaadeh [J. Comp. Phys. 274, 803 (2014), 10.1016/j.jcp.2014.06.053] and Zadehgol [Phys. Rev. E 91, 063311 (2015), 10.1103/PhysRevE.91.063311]. The CSKM is then used as a basis to show that the complex-valued equilibrium distribution function of the present model can be identified with a simple singularity in the complex phase space. The virtual particles, in the present work, are concentrated on virtual "branes" which surround the computational nodes. Employing the Cauchy integral formula, it is shown that certain variations of the "branes," in the complex phase space, do not affect the local kinetic states. This property of the new model, which is referred to as the "apparent jumps" in the present work, is used to construct new models. The theoretical findings have been tested by simulating three benchmark flows. The results of the present simulations are in excellent agreement with the previous results reported by others.

  16. Critical behaviors and phase transitions of black holes in higher order gravities and extended phase spaces

    CERN Document Server

    Sherkatghanad, Zeinab; Mirzaeyan, Zahra; Mansoori, Seyed Ali Hosseini

    2014-01-01

    We consider the critical behaviors and phase transitions of Gauss Bonnet-Born Infeld-AdS black holes (GB-BI-AdS) for $d=5,6$ and the extended phase space. We assume the cosmological constant, $\\Lambda$, the coupling coefficient $\\alpha$, and the BI parameter $\\beta$ to be thermodynamic pressures of the system. Having made these assumptions, the critical behaviors are then studied in the two canonical and grand canonical ensembles. We find "reentrant and triple point phase transitions" (RPT-TP) and "multiple reentrant phase transitions" (multiple RPT) with increasing pressure of the system for specific values of the coupling coefficient $\\alpha$ in the canonical ensemble. Also, we observe a reentrant phase transition (RPT) of GB-BI-AdS black holes in the grand canonical ensemble and for $d=6$. These calculations are then expanded to the critical behavior of Born-Infeld-AdS (BI-AdS) black holes in the third order of Lovelock gravity and in the grand canonical ensemble to find a Van der Waals behavior for $d=7$ ...

  17. Lead-Free Experiment in a Space Environment

    Science.gov (United States)

    Blanche, J. F.; Strickland, S. M.

    2012-01-01

    This Technical Memorandum addresses the Lead-Free Technology Experiment in Space Environment that flew as part of the seventh Materials International Space Station Experiment outside the International Space Station for approximately 18 months. Its intent was to provide data on the performance of lead-free electronics in an actual space environment. Its postflight condition is compared to the preflight condition as well as to the condition of an identical package operating in parallel in the laboratory. Some tin whisker growth was seen on a flight board but the whiskers were few and short. There were no solder joint failures, no tin pest formation, and no significant intermetallic compound formation or growth on either the flight or ground units.

  18. The phase-space structure of tidally stripped haloes

    Science.gov (United States)

    Drakos, Nicole E.; Taylor, James E.; Benson, Andrew J.

    2017-06-01

    We propose a new method for generating equilibrium models of spherical systems of collisionless particles that are finite in extent, but whose central regions resemble dark matter haloes from cosmological simulations. This method involves iteratively removing unbound particles from a Navarro-Frenk-White (NFW) profile truncated sharply at some radius. The resulting models are extremely stable, and thus provide a good starting point for N-body simulations of isolated haloes. We provide a code to generate such models for NFW and a variety of other common density profiles. We then develop an analytic approximation to this truncated distribution function. Our method proceeds by analogy with the King model, truncating and shifting the original distribution function of an infinitely extended NFW profile in energy space. We show that the density profiles of our models closely resemble the tidally truncated density profiles seen previously in studies of satellite evolution. Pursuing this analogy further with a series of simulations of tidal mass-loss, we find that our models provide a good approximation to the full distribution function of tidally stripped systems, thus allowing theoretically motivated phase-space calculations for such systems.

  19. On Quantum Mechanics on Noncommutative Quantum Phase Space

    Science.gov (United States)

    Djemaï, A. E. F.; Smail, H.

    2004-06-01

    In this work, we develop a general framework in which Noncommutative Quantum Mechanics (NCQM), characterized by a space noncommutativity matrix parameter θ=ɛ^kijθ_k and a momentum noncommutativity matrix parameter βij=ɛ^kijβ_k, is shown to be equivalent to Quantum Mechanics (QM) on a suitable transformed Quantum Phase Space (QPS). Imposing some constraints on this particular transformation, we firstly find that the product of the two parameters θ and β possesses a lower bound in direct relation with Heisenberg incertitude relations, and secondly that the two parameters are equivalent but with opposite sign, up to a dimension factor depending on the physical system under study. This means that noncommutativity is represented by a unique parameter which may play the role of a fundamental constant characterizing the whole NCQPS. Within our framework, we treat some physical systems on NCQPS : free particle, harmonic oscillator, system of two-charged particles, Hydrogen atom. Among the obtained results, we discover a new phenomenon which consists of a free particle on NCQPS viewed as equivalent to a harmonic oscillator with Larmor frequency depending on β, representing the same particle in presence of a magnetic field B=q-1β. For the other examples, additional correction terms depending on β appear in the expression of the energy spectrum. Finally, in the two-particle system case, we emphasize the fact that for two opposite charges noncommutativity is effectively feeled with opposite sign.

  20. Nonlinear Landau-Zener tunneling in quantum phase space

    Energy Technology Data Exchange (ETDEWEB)

    Trimborn, F [Institut fuer theoretische Physik, Leibniz Universitaet Hannover, D-30167 Hannover (Germany); Witthaut, D [QUANTOP, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); Kegel, V; Korsch, H J, E-mail: friederike.trimborn@itp.uni-hannover.d [Fachbereich Physik, TU Kaiserslautern, D-67663 Kaiserslautern (Germany)

    2010-05-15

    We present a detailed analysis of the Landau-Zener problem for an interacting Bose-Einstein condensate in a time-varying double-well trap, especially focusing on the relation between the full many-particle problem and the mean-field approximation. Due to the nonlinear self-interaction a dynamical instability occurs, which leads to a breakdown of adiabaticity and thus fundamentally alters the dynamics. It is shown that essentially all the features of the Landau-Zener problem including the depletion of the condensate mode can be already understood within a semiclassical phase-space picture. In particular, this treatment resolves the formerly imputed incommutability of the adiabatic and semiclassical limits. The possibility of exploiting Landau-Zener sweeps to generate squeezed states for spectroscopic tasks is analyzed in detail. Moreover, we study the influence of phase noise and propose a Landau-Zener sweep as a sensitive yet readily implementable probe for decoherence, since the noise has significant effect on the transition rate for slow parameter variations.

  1. Experiment 305: Pathophysiology of Mineral Loss During Space Flight

    Science.gov (United States)

    Arnaud, Claude D.; Cann, Christopher E.

    1995-01-01

    The objective of this SLS-2 experiment was to determine the pathophysiology of mineral loss during space flight. This was to be accomplished by (1) determining the concentrations of blood minerals and of calciotropic hormones (parathyroid hormone-PTH, vitamin D metabolites) before, during, and after a 14 day shuttle flight, and (2) determining, by calcium kinetic analysis (using stable calcium isotopes), the influence of space flight on intestinal calcium absorption .

  2. NBS (National Bureau of Standards): Materials measurements. [space processing experiments

    Science.gov (United States)

    Manning, J. R.

    1983-01-01

    Work directed toward the measurement of materials properties important to the design and interpretation of space processing experiments and determinations of how the space environment may offer a unique opportunity for performing improved measurements and producing materials with improved properties is reported. Surface tensions and their variations with temperature and impurities; convection during undirectional solidification; and measurement of the high temperature thermophysical properties of tungsten group liquids and solids are discussed and results are summarized.

  3. Hybrid phase-space-Fock-space approach to evolution of a driven nonlinear resonator

    Science.gov (United States)

    Khezri, Mostafa; Korotkov, Alexander N.

    2017-10-01

    We analyze the quantum evolution of a weakly nonlinear resonator due to a classical near-resonant drive and damping. The resonator nonlinearity leads to squeezing and heating of the resonator state. Using a hybrid phase-space-Fock-space representation for the resonator state within the Gaussian approximation, we derive evolution equations for the four parameters characterizing the Gaussian state. Numerical solution of these four ordinary differential equations is much simpler and faster than simulation of the full density matrix evolution, while providing good accuracy for the system analysis during transients and in the steady state. We show that steady-state squeezing of the resonator state is limited by 3 dB; however, this limit can be exceeded during transients.

  4. Kinetics for Reduction of Iron Ore Based on the Phase Space Reconstruction

    Directory of Open Access Journals (Sweden)

    Guo-Feng Fan

    2014-01-01

    Full Text Available A series of smelting reduction experiments has been carried out with high-phosphorus iron ore of the different bases and heating rates by thermogravimetric analyzer. The derivative thermo gravimetric (DTG data have been obtained from the experiments. After analyzing its phase space reconstruction, it is found that DTG phase portrait contains with a clear double “∞” attractor characteristic by one-order delay. The statistical properties of the attractor inside and outside the double “∞” structures are characterized with interface chemical reaction control and diffusion control stage in dynamic smelting process, respectively; the results are deserved to be a reference value on understanding of the mechanism and optimization and control of the process in smelting reduction of high-phosphorus iron ore.

  5. The Living With a Star Space Environment Testbed Experiments

    Science.gov (United States)

    Xapsos, Michael A.

    2014-01-01

    The focus of the Living With a Star (LWS) Space Environment Testbed (SET) program is to improve the performance of hardware in the space radiation environment. The program has developed a payload for the Air Force Research Laboratory (AFRL) Demonstration and Science Experiments (DSX) spacecraft that is scheduled for launch in August 2015 on the SpaceX Falcon Heavy rocket. The primary structure of DSX is an Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) ring. DSX will be in a Medium Earth Orbit (MEO). This oral presentation will describe the SET payload.

  6. A robot in space as a large space structures control experiment

    Science.gov (United States)

    Gran, R.

    1983-01-01

    The control systems design issues for large space structures can be addressed by a robotics experiment which defines a teleoperator or a robot or uses the RMS. The robotics control demonstration brings the large space structures control technology to an effective state of readiness and provides a useful robot when the experiment is finished. Three major options in such an experiment are the RMS, a flexible arm that is going to be put on the Shuttle for other reasons, or a dexetrous manipulator or teleoperator.

  7. Skylab Experiments, Volume 7, Living and Working in Space.

    Science.gov (United States)

    National Aeronautics and Space Administration, Washington, DC.

    Basic knowledge about Skylab experiments is presented in this book for the purpose of informing high school teachers about scientific research performed in orbit and enabling the teachers to broaden their scope of material selection. The seventh volume deals with the ability of the Skylab crew to live and work effectively in space. The content is…

  8. High Temperature Superconducting Space Experiment II (HTSSE II) cryogenic design

    Science.gov (United States)

    Kawecki, T. G.; Chappie, S. S.; Mahony, D. R.

    At 60 to 80 K large performance gains are possible from high temperature superconducting (HTS) microwave devices for communications applications. The High Temperature Superconducting Space Experiment II (HTSSE II) will demonstrate eight HTS experiments in space for up to 3 years of operation. HTSSE II is the first application of HTS technology to space. In addition to demonstrating HTS devices, an important secondary goal is to demonstrate the cryogenic technologies required for long life HTS space applications. HTSSE II utilizes a British Aerospace 80 K Stirling cycle cryocooler to refrigerate a central cryogenic bus of seven HTS experiments and has an additional stand-alone TRW HTS experiment cooled by a TRW Stirling cycle cryocooler. The HTSSE II flight unit has been assembled and has successfully passed vibration and thermal vacuum environmental tests. HTSSE II was developed on a fixed budget and a fast track schedule of 24 months and is due to launch in March 1997 on the ARGOS spacecraft. This paper presents the design and test results of the cryogenic subsystem, cryocooler integration and a cryogenic coaxial cable I/O assembly.

  9. Students' Experience of Problem-Based Learning in Virtual Space

    Science.gov (United States)

    Gibbings, Peter; Lidstone, John; Bruce, Christine

    2015-01-01

    This paper reports outcomes of a study focused on discovering qualitatively different ways students experience problem-based learning in virtual space. A well-accepted and documented qualitative research method was adopted for this study. Five qualitatively different conceptions are described, each revealing characteristics of increasingly complex…

  10. DVB-S2 Experiment over NASA's Space Network

    Science.gov (United States)

    Downey, Joseph A.; Evans, Michael A.; Tollis, Nicholas S.

    2017-01-01

    The commercial DVB-S2 standard was successfully demonstrated over NASAs Space Network (SN) and the Tracking Data and Relay Satellite System (TDRSS) during testing conducted September 20-22nd, 2016. This test was a joint effort between NASA Glenn Research Center (GRC) and Goddard Space Flight Center (GSFC) to evaluate the performance of DVB-S2 as an alternative to traditional NASA SN waveforms. Two distinct sets of tests were conducted: one was sourced from the Space Communication and Navigation (SCaN) Testbed, an external payload on the International Space Station, and the other was sourced from GRCs S-band ground station to emulate a Space Network user through TDRSS. In both cases, a commercial off-the-shelf (COTS) receiver made by Newtec was used to receive the signal at White Sands Complex. Using SCaN Testbed, peak data rates of 5.7 Mbps were demonstrated. Peak data rates of 33 Mbps were demonstrated over the GRC S-band ground station through a 10MHz channel over TDRSS, using 32-amplitude phase shift keying (APSK) and a rate 89 low density parity check (LDPC) code. Advanced features of the DVB-S2 standard were evaluated, including variable and adaptive coding and modulation (VCMACM), as well as an adaptive digital pre-distortion (DPD) algorithm. These features provided additional data throughput and increased link performance reliability. This testing has shown that commercial standards are a viable, low-cost alternative for future Space Network users.

  11. Mission Possible: BioMedical Experiments on the Space Shuttle

    Science.gov (United States)

    Bopp, E.; Kreutzberg, K.

    2011-01-01

    Biomedical research, both applied and basic, was conducted on every Shuttle mission from 1981 to 2011. The Space Shuttle Program enabled NASA investigators and researchers from around the world to address fundamental issues concerning living and working effectively in space. Operationally focused occupational health investigations and tests were given priority by the Shuttle crew and Shuttle Program management for the resolution of acute health issues caused by the rigors of spaceflight. The challenges of research on the Shuttle included: limited up and return mass, limited power, limited crew time, and requirements for containment of hazards. The sheer capacity of the Shuttle for crew and equipment was unsurpassed by any other launch and entry vehicle and the Shuttle Program provided more opportunity for human research than any program before or since. To take advantage of this opportunity, life sciences research programs learned how to: streamline the complicated process of integrating experiments aboard the Shuttle, design experiments and hardware within operational constraints, and integrate requirements between different experiments and with operational countermeasures. We learned how to take advantage of commercial-off-the-shelf hardware and developed a hardware certification process with the flexibility to allow for design changes between flights. We learned the importance of end-to-end testing for experiment hardware with humans-in-the-loop. Most importantly, we learned that the Shuttle Program provided an excellent platform for conducting human research and for developing the systems that are now used to optimize research on the International Space Station. This presentation will include a review of the types of experiments and medical tests flown on the Shuttle and the processes that were used to manifest and conduct the experiments. Learning Objective: This paper provides a description of the challenges related to launching and implementing biomedical

  12. Experimental evidence of adiabatic splitting of charged particle beams using stable islands of transverse phase space

    Directory of Open Access Journals (Sweden)

    S. Gilardoni

    2006-10-01

    Full Text Available Recently, a novel technique to perform multiturn extraction from a circular particle accelerator was proposed. It is based on beam splitting and trapping, induced by a slow crossing of a nonlinear resonance, inside stable islands of transverse phase space. Experiments at the CERN Proton Synchrotron started in 2002 and evidence of beam splitting was obtained by summer 2004. In this paper, the measurement results achieved with both a low- and a high-intensity, single-bunch proton beam are presented.

  13. Space Debris Radar Experiments at the Medicina VLBI Dish

    Science.gov (United States)

    Pupillo, G.; Montebugnoli, S.; Di Martino, M.; Salerno, E.; Bartolini, M.; Pluchino, S.; Schilliro, F.; Anselmo, L.; Portelli, C.; Konovalenko, A.; Nabatov, A.

    2009-03-01

    In 2007 three space debris detection tests were performed in the framework of a monitoring program carried out by the Istituto Nazionale di Astrofisica - INAF - in collaboration with the Italian Space Agency - ASI. The observations were made by using the bistatic radar technique. The INAF 32 m radiotelescope located at Medicina (Bologna, Italy) was used as receiver whereas the Ukrainian 70 m parabolic antenna located at Evpatoria was utilized as transmitter. The aim of the experiment was to test the sensitivity of the Medicina-Evpatoria radar system in space debris detection, and to validate and optimize the hardware setup. Measurements were mainly carried out on inactive satellites and catalogued space debris. However the search for new fragments in LEO was also performed during the campaign. This paper reports on results of these observations.

  14. Exploring Heart and Lung Function in Space: ARMS Experiments

    Science.gov (United States)

    Kuipers, Andre; Cork, Michael; LeGouic, Marine

    2002-01-01

    The Advanced Respiratory Monitoring System (ARMS) is a suite of monitoring instruments and supplies used to study the heart, lungs, and metabolism. Many experiments sponsored by the European Space Agency (ESA) will be conducted using ARMS during STS-107. The near-weightless environment of space causes the body to undergo many physiological adaptations, and the regulation of blood pressure is no exception. Astronauts also experience a decrease in blood volume as an adaptation to microgravity. Reduced blood volume may not provide enough blood pressure to the head during entry or landing. As a result, astronauts often experience light-headedness, and sometimes even fainting, when they stand shortly after returning to Earth. To help regulate blood pressure and heart rate, baroreceptors, sensors located in artery walls in the neck and near the heart, control blood pressure by sending information to the brain and ensuring blood flow to organs. These mechanisms work properly in Earth's gravity but must adapt in the microgravity environment of space. However, upon return to Earth during entry and landing, the cardiovascular system must readjust itself to gravity, which can cause fluctuation in the control of blood pressure and heart rate. Although the system recovers in hours or days, these occurrences are not easily predicted or understood - a puzzle investigators will study with the ARMS equipment. In space, researchers can focus on aspects of the cardiovascular system normally masked by gravity. The STS-107 experiments using ARMS will provide data on how the heart and lungs function in space, as well as how the nervous system controls them. Exercise will also be combined with breath holding and straining (the Valsalva maneuver) to test how heart rate and blood pressure react to different stresses. This understanding will improve astronauts' cardiopulmonary function after return to Earth, and may well help Earthbound patients who experience similar effects after long

  15. Phase Space Dissimilarity Measures for Structural Health Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Bubacz, Jacob A [ORNL; Chmielewski, Hana T [ORNL; Pape, Alexander E [ORNL; Depersio, Andrew J [ORNL; Hively, Lee M [ORNL; Abercrombie, Robert K [ORNL; Boone, Shane [ORNL

    2011-11-01

    A novel method for structural health monitoring (SHM), known as the Phase Space Dissimilarity Measures (PSDM) approach, is proposed and developed. The patented PSDM approach has already been developed and demonstrated for a variety of equipment and biomedical applications. Here, we investigate SHM of bridges via analysis of time serial accelerometer measurements. This work has four aspects. The first is algorithm scalability, which was found to scale linearly from one processing core to four cores. Second, the same data are analyzed to determine how the use of the PSDM approach affects sensor placement. We found that a relatively low-density placement sufficiently captures the dynamics of the structure. Third, the same data are analyzed by unique combinations of accelerometer axes (vertical, longitudinal, and lateral with respect to the bridge) to determine how the choice of axes affects the analysis. The vertical axis is found to provide satisfactory SHM data. Fourth, statistical methods were investigated to validate the PSDM approach for this application, yielding statistically significant results.

  16. Phase space of modified Gauss-Bonnet gravity

    Energy Technology Data Exchange (ETDEWEB)

    Carloni, Sante [Universidade de Lisboa-UL, Centro Multidisciplinar de Astrofisica-CENTRA, Instituto Superior Tecnico-IST, Lisbon (Portugal); Mimoso, Jose P. [Instituto de Astrofisica e Ciencias do Espaco, Universidade de Lisboa, Departamento de Fisica, Faculdade de Ciencias, Lisbon (Portugal)

    2017-08-15

    We investigate the evolution of non-vacuum Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetimes with any spatial curvature in the context of Gauss-Bonnet gravity. The analysis employs a new method which enables us to explore the phase space of any specific theory of this class. We consider several examples, discussing the transition from a decelerating into an acceleration universe within these theories. We also deduce from the dynamical equations some general conditions on the form of the action which guarantee the presence of specific behaviours like the emergence of accelerated expansion. As in f(R) gravity, our analysis shows that there is a set of initial conditions for which these models have a finite time singularity which can be an attractor. The presence of this instability also in the Gauss-Bonnet gravity is to be ascribed to the fourth-order derivative in the field equations, i.e., is the direct consequence of the higher order of the equations. (orig.)

  17. Phase space of modified Gauss-Bonnet gravity

    Science.gov (United States)

    Carloni, Sante; Mimoso, José P.

    2017-08-01

    We investigate the evolution of non-vacuum Friedmann-Lemaître-Robertson-Walker (FLRW) spacetimes with any spatial curvature in the context of Gauss-Bonnet gravity. The analysis employs a new method which enables us to explore the phase space of any specific theory of this class. We consider several examples, discussing the transition from a decelerating into an acceleration universe within these theories. We also deduce from the dynamical equations some general conditions on the form of the action which guarantee the presence of specific behaviours like the emergence of accelerated expansion. As in f( R) gravity, our analysis shows that there is a set of initial conditions for which these models have a finite time singularity which can be an attractor. The presence of this instability also in the Gauss-Bonnet gravity is to be ascribed to the fourth-order derivative in the field equations, i.e., is the direct consequence of the higher order of the equations.

  18. Covariant phase space, constraints, gauge and the Peierls formula

    Science.gov (United States)

    Khavkine, Igor

    2014-02-01

    It is well known that both the symplectic structure and the Poisson brackets of classical field theory can be constructed directly from the Lagrangian in a covariant way, without passing through the noncovariant canonical Hamiltonian formalism. This is true even in the presence of constraints and gauge symmetries. These constructions go under the names of the covariant phase space formalism and the Peierls bracket. We review both of them, paying more careful attention, than usual, to the precise mathematical hypotheses that they require, illustrating them in examples. Also an extensive historical overview of the development of these constructions is provided. The novel aspect of our presentation is a significant expansion and generalization of an elegant and quite recent argument by Forger and Romero showing the equivalence between the resulting symplectic and Poisson structures without passing through the canonical Hamiltonian formalism as an intermediary. We generalize it to cover theories with constraints and gauge symmetries and formulate precise sufficient conditions under which the argument holds. These conditions include a local condition on the equations of motion that we call hyperbolizability, and some global conditions of cohomological nature. The details of our presentation may shed some light on subtle questions related to the Poisson structure of gauge theories and their quantization.

  19. Solar array experiments on the SPHINX satellite. [Space Plasma High voltage INteraction eXperiment satellite

    Science.gov (United States)

    Stevens, N. J.

    1974-01-01

    The Space Plasma, High Voltage Interaction Experiment (SPHINX) is the name given to an auxiliary payload satellite scheduled to be launched in January 1974. The principal experiments carried on this satellite are specifically designed to obtain the engineering data on the interaction of high voltage systems with the space plasma. The classes of experiments are solar array segments, insulators, insulators with pin holes and conductors. The satellite is also carrying experiments to obtain flight data on three new solar array configurations: the edge illuminated-multijunction cells, the teflon encased cells, and the violet cells.

  20. Design and Development of a compact and ruggest phase and flouresence microscope for space utilization Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this SBIR Phase 1 we propose to develop a novel microscope by integrating Fourier phase contrast microscopy (FPCM) and epi-fluorescence microscopy. In FPCM, the...

  1. High Performance Ka-band Phase Shifters for Space Telecommunications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a novel MEMS-based digital phase shifter targeted for Ka-band operation, but scalable down to X-band and up to W-band. This novel phase shifter will...

  2. Intimate space within institutionalized birth: women's experiences birthing with doulas.

    Science.gov (United States)

    Hunter, Cheryl

    2012-01-01

    Childbirth in the American context is only peripherally conceptualized in the domain of the family and home, demonstrating the primacy of the biomedical model of childbirth in the institutional setting of the hospital. Medical research has found positive outcomes when women labor with 'doulas', paraprofessionals who are trained and experienced in childbirth. However, medical research has yet to explore the complexity of the labor experience of women with doulas, offering potential insights into how those positive outcomes may come about. Doulas define what they do in birth as 'holding the space'. This research explored what 'holding the space' meant in terms of the experience of childbirth with women who employed doulas. The findings suggest that doulas' conceptualizations of the space of birth were framed in terms of creating/maintaining intimacy and that doulas and women maintained this intimate space even within the institutionalized medical-clinical birth experience. Implications of this research do not point to the generalization of doula attributes for implementation on an institutional level, but rather validate the contributions of external caregivers to producing positive outcomes.

  3. Multiphase flow and phase change in microgravity: Fundamental research and strategic research for exploration of space

    Science.gov (United States)

    Singh, Bhim S.

    2003-01-01

    . The fundamental research in multiphase flow and phase change in microgravity is aimed at developing better mechanistic understanding of pool boiling and ascertaining the effects of gravity on heat transfer and the critical heat flux. Space flight experiments conducted in space have shown that nucleate pool boiling can be sustained under certain conditions in the microgravity environment. New space flight experiments are being developed to provide more quantitative information on pool boiling in microgravity. Ground-based investigations are also being conducted to develop mechanistic models for flow and pool boiling. An overview of the research plan and roadmap for the strategic research in multiphase flow and phase change as well as research findings from the ongoing program will be presented.

  4. Forced Forward Smoldering Experiments Aboard The Space Shuttle

    Science.gov (United States)

    Fernandez-Pello, A. C.; Bar-Ilan, A.; Rein, G.; Urban, D. L.; Torero, J. L.

    2003-01-01

    Smoldering is a basic combustion problem that presents a fire risk because it is initiated at low temperatures and because the reaction can propagate slowly in the material interior and go undetected for long periods of time. It yields a higher conversion of fuel to toxic compounds than does flaming, and may undergo a transition to flaming. To date there have been a few minor incidents of overheated and charred cables and electrical components reported on Space Shuttle flights. With the establishment of the International Space Station, and the planning of a potential manned mission to Mars, there has been an increased interest in the study of smoldering in microgravity. The Microgravity Smoldering Combustion (MSC) experiment is part of a study of the smolder characteristics of porous combustible materials in a spacecraft environment. The aim of the experiment is to provide a better fundamental understanding of the controlling mechanisms of smoldering combustion under normal- and microgravity conditions. This in turn will aid in the prevention and control of smolder originated fires, both on earth and in spacecrafts. The microgravity smoldering experiments have to be conducted in a space-based facility because smoldering is a very slow process and consequently its study in a microgravity environment requires extended periods of time. The microgravity experiments reported here were conducted aboard the Space Shuttle. The most recent tests were conducted during the STS-105 and STS-108 missions. The results of the forward smolder experiments from these flights are reported here. In forward smolder, the reaction front propagates in the same direction as the oxidizer flow. The heat released by the heterogeneous oxidation reaction is transferred ahead of the reaction heating the unreacted fuel. The resulting increase of the virgin fuel temperature leads to the onset of the smolder reaction, and propagates through the fuel. The MSC data are compared with normal gravity

  5. Generalised partition functions: inferences on phase space distributions

    Directory of Open Access Journals (Sweden)

    R. A. Treumann

    2016-06-01

    Full Text Available It is demonstrated that the statistical mechanical partition function can be used to construct various different forms of phase space distributions. This indicates that its structure is not restricted to the Gibbs–Boltzmann factor prescription which is based on counting statistics. With the widely used replacement of the Boltzmann factor by a generalised Lorentzian (also known as the q-deformed exponential function, where κ = 1∕|q − 1|, with κ, q ∈ R both the kappa-Bose and kappa-Fermi partition functions are obtained in quite a straightforward way, from which the conventional Bose and Fermi distributions follow for κ → ∞. For κ ≠ ∞ these are subject to the restrictions that they can be used only at temperatures far from zero. They thus, as shown earlier, have little value for quantum physics. This is reasonable, because physical κ systems imply strong correlations which are absent at zero temperature where apart from stochastics all dynamical interactions are frozen. In the classical large temperature limit one obtains physically reasonable κ distributions which depend on energy respectively momentum as well as on chemical potential. Looking for other functional dependencies, we examine Bessel functions whether they can be used for obtaining valid distributions. Again and for the same reason, no Fermi and Bose distributions exist in the low temperature limit. However, a classical Bessel–Boltzmann distribution can be constructed which is a Bessel-modified Lorentzian distribution. Whether it makes any physical sense remains an open question. This is not investigated here. The choice of Bessel functions is motivated solely by their convergence properties and not by reference to any physical demands. This result suggests that the Gibbs–Boltzmann partition function is fundamental not only to Gibbs–Boltzmann but also to a large class of generalised Lorentzian distributions as well as to the

  6. Electrostatics of Granular Material (EGM): Space Station Experiment

    Science.gov (United States)

    Marshall, J.; Sauke, T.; Farrell, W.

    2000-01-01

    Aggregates were observed to form very suddenly in a lab-contained dust cloud, transforming (within seconds) an opaque monodispersed cloud into a clear volume containing rapidly-settling, long hair-like aggregates. The implications of such a "phase change" led to a series of experiments progressing from the lab, to KC-135, followed by micro-g flights on USML-1 and USML-2, and now EGM slated for Space Station. We attribute the sudden "collapse" of a cloud to the effect of dipoles. This has significant ramifications for all types of cloud systems, and additionally implicates dipoles in the processes of cohesion and adhesion of granular matter. Notably, there is the inference that like-charged grains need not necessarily repel if they are close enough together: attraction or repulsion depends on intergranular distance (the dipole being more powerful at short range), and the D/M ratio for each grain, where D is the dipole moment and M is the net charge. We discovered that these ideas about dipoles, the likely pervasiveness of them in granular material, the significance of the D/M ratio, and the idea of mixed charges on individual grains resulting from tribological processes --are not universally recognized in electrostatics, granular material studies, and aerosol science, despite some early seminal work in the literature, and despite commercial applications of dipoles in such modern uses as "Krazy Glue", housecleaning dust cloths, and photocopying. The overarching goal of EGM is to empirically prove that (triboelectrically) charged dielectric grains of material have dipole moments that provide an "always attractive" intergranular force as a result of both positive and negative charges residing on the surfaces of individual grains. Microgravity is required for this experiment because sand grains can be suspended as a cloud for protracted periods, the grains are free to rotate to express their electrostatic character, and Coulombic forces are unmasked. Suspended grains

  7. Space, body, time and relationship experiences of recess physical activity

    DEFF Research Database (Denmark)

    Pawlowski, Charlotte Skau; Andersen, Henriette Bondo; Tjørnhøj-Thomsen, Tine

    2016-01-01

    the classroom as a space for physical activity, designing schoolyards with smaller secluded spaces and varied facilities, improving children's self-esteem and body image, e.g., during physical education, and creating teacher organised play activities during recess.......BACKGROUND: Increasing recess physical activity has been the aim of several interventions, as this setting can provide numerous physical activity opportunities. However, it is unclear if these interventions are equally effective for all children, or if they only appeal to children who are already...... physically active. This study was conducted to explore the least physically active children's "lived experiences" within four existential lifeworlds linked to physical activity during recess: space, body, time, and relations. METHODS: The study builds on ethnographic fieldwork in a public school in Denmark...

  8. Review of Nuclear Physics Experiments for Space Radiation

    Science.gov (United States)

    Norbury, John W.; Miller, Jack; Adamczyk, Anne M.; Heilbronn, Lawrence H.; Townsend, Lawrence W.; Blattnig, Steve R.; Norman, Ryan B.; Guetersloh, Stephen B.; Zeitlin, Cary J.

    2011-01-01

    Human space flight requires protecting astronauts from the harmful effects of space radiation. The availability of measured nuclear cross section data needed for these studies is reviewed in the present paper. The energy range of interest for radiation protection is approximately 100 MeV/n to 10 GeV/n. The majority of data are for projectile fragmentation partial and total cross sections, including both charge changing and isotopic cross sections. The cross section data are organized into categories which include charge changing, elemental, isotopic for total, single and double differential with respect to momentum, energy and angle. Gaps in the data relevant to space radiation protection are discussed and recommendations for future experiments are made.

  9. Space experiments on basic technologies for a space elevator using microsatellites

    Science.gov (United States)

    Yamagiwa, Yoshiki; Nohmi, Masahiro; Aoki, Yoshio; Momonoi, Yu; Nanba, Hirotaka; Aiga, Masanori; Kumao, Takeru; Watahiki, Masahito

    2017-09-01

    We attempt to verify two basic technologies required for a space elevator using microsatellites; the tether (cable) deployment technology and the climber operation along the tether in space. Tether deployment is performed by a CubeSat called STARS-C (Space Tethered Autonomous Robotic Satellite - Cube) which will be released from the Japanese experimental module Kibo on ISS early in 2017. STARS-C consists of a mother satellite (MS) and daughter satellite (DS) connected by a 100-m tether. Its mission is focused on the tether deployment for studying the tether dynamics during the deployment with the goal of improving the smoothness of such deployment in future tether missions including space elevator. The MS and DS have common subsystems, including power, communication, and command and data handling systems. They also have a tether unit with spool and reel mechanisms as a mission system. In addition, we have been designing the next-step microsatellite called STARS-E (Space Tethered Autonomous Robotic Satellite - Elevator) under a Grant-in-Aid for Scientific Research. STARS-E is a 500-mm size satellite intended to verify the climber operation in space. It consists of a MS and DS jointed by a 2-km tether, and a climber that moves along the tether. STARS-C was launched on December 9 in 2016 and will be performed its mission early in 2017. STARS-E is in the BBM phase, and some designs are currently being fixed.

  10. The active phasing experiment: Part I. Concept and objectives

    Science.gov (United States)

    Yaitskova, Natalia; Gonte, Frederic; Derie, Frederic; Noethe, Lothar; Surdej, Isabelle; Karban, Robert; Dohlen, Kjetil; Langlois, Maud; Esposito, Simone; Pinna, Enrico; Reyes, Marcos; Montoya, Lusma; Terrett, David

    2006-06-01

    In a framework of ELT design study our group is building an Active Phasing Experiment (APE), the main goals of which is to demonstrate the non-adaptive wavefront control scheme and technology for Extremely Large Telescope (ELT). The experiment includes verification and test of different phasing sensors and integration of a phasing wavefront sensor into a global scheme of segmented telescope active control. After a sufficient number of tests in the laboratory APE will be mounted and tested on sky at a Nasmyth focus of a VLT unit telescope. The paper presents APE as a demonstrator of particular aspects of ELT and provides a general understanding concerning the strategy of segmented mirrors active control.

  11. Space, body, time and relationship experiences of recess physical activity

    DEFF Research Database (Denmark)

    Pawlowski, Charlotte Skau; Andersen, Henriette Bondo; Tjørnhøj-Thomsen, Tine

    2016-01-01

    physically active. This study was conducted to explore the least physically active children's "lived experiences" within four existential lifeworlds linked to physical activity during recess: space, body, time, and relations. METHODS: The study builds on ethnographic fieldwork in a public school in Denmark...... using a combination of participatory photo interviews and participant observation. Thirty-seven grade five children (11-12 years old) were grouped in quartiles based on their objectively measured daily physical activity levels. Eight children in the lowest activity quartile (six girls) were selected...... to participate in the study. To avoid stigmatising and to make generalisations more reliable we further recruited eight children from the two highest activity quartiles (four girls) to participate. RESULTS: An analysis of the least physically active children's "lived experiences" of space, body, time...

  12. Aesthetic Experience Explained by the Affect-Space Framework

    Directory of Open Access Journals (Sweden)

    Emery Schubert

    2017-04-01

    Full Text Available A framework for organizing the semantic structure of aesthetic experience is proposed. The new framework is presented in an 'affect-space' and consists of three sets of dichotomous classifications: (1 internal locus (the felt experience versus external locus (the description of the object, (2 'affect-valence' — the attraction to (positive valence, e.g. preference, awe or repulsion from (negative valence, e.g. hatred, disgust the artwork/object — versus 'emotion-valence' — the character/contemplation of an emotion (happiness-an example of positive valence, sadness-an example of negative valence, and (3 deep versus shallow hedonic tone—e.g. 'awe' is deep, 'preference' is shallow. Deep hedonic tone is proposed as a better index of aesthetic experience (awe, being moved etc. than shallow hedonic tone (preference, pleasure, enjoyment. Deep, internal locus, affect-valence during the contemplation of an object amenable to an aesthetic judgement (beautiful, ugly etc. presents the necessary and sufficient conditions for an aesthetic experience. The framework allows future researchers to consider which aspects of an experience come closest to actual aesthetic experience from an empirical aesthetics perspective. It also highlights the limited value in grouping together so many aesthetic experiences under the rubric of emotion, such as aesthetic emotions, preference, basic emotions and so forth. Our framework paves the way for testing and further development of theory on aesthetic experience.

  13. On the design of a planar phased array radar antenna architecture for space debris situational awareness

    OpenAIRE

    Garcia-Gasco Trujillo, Javier; Noval Sánchez de Toca, Alvaro; Montesinos Ortego, Ignacio; Fernández González, José Manuel; Sierra Pérez, Manuel

    2013-01-01

    The Space Situational Awareness (SSA) program from the European Space Agency (ESA) protects Europe's citizens and their satellite-based services by detecting space hazards. ESA Ground Systems (GS) division is currently designing a phased array radar composed of thousands of radiating elements for future stages of the SSA program [1]. The radar shall guarantee the detection of most of the Low Earth Orbit (LEO) space debris, providing a general map of space junk. While range accuracy is mainly ...

  14. Communications experiment for the Nuclear Electric Propulsion Space Test Program (NEPSTP)

    Science.gov (United States)

    Bokulic, Robert S.; Gatsonis, Nikolaos A.; Bythrow, Peter F.; Mauk, Barry H.

    1993-06-01

    A planned experiment for characterizing RF/plume interaction effects on the Nuclear Electric Propulsion Space Test Program (NEPSTP) is described. The NEPSTP spacecraft will use a Russian Topaz II nuclear reactor to power a suite of electric thrusters on-orbit. Transmission of signals through the thruster plumes at S-band (2 GHz) will be characterized over a wide range of viewing angles by controlling the spacecraft attitude as it passes by the ground station. Planned measurements include signal strength, bit error count, scintillation, phase transient effects, and radio frequency interference. Possible future augmentations to the experiment, including a UHF transmitter and a measurement of total election content, are also described.

  15. Variational principle and phase space measure in non-canonical coordinates

    Directory of Open Access Journals (Sweden)

    Sergi, A

    2005-11-01

    Full Text Available Non-canonical equations of motion are derived from a variational principle written in symplectic form. The invariant measure of phase space and the covariant expression for the entropy are derived from non-canonical transformations of coordinates. This shows that the geometry of non-canonical phase space is non trivial even if dynamics has no compressibility.

  16. Higher order point and continuum mechanics from phase-space action

    Energy Technology Data Exchange (ETDEWEB)

    Shamanna, J.; Talukdar, B.; Das, U

    2002-12-02

    It is pointed out that use of phase-space action provides an elegant method to study the canonical structure of problems in mechanics. Higher order Lagrangian systems are Hamiltonized by employing the variational principle in phase space. Studies are envisaged for both particle dynamics and field theory. Hamilton's equations are expressed in terms of appropriate Poisson brackets.

  17. Tunneling of an energy eigenstate through a parabolic barrier viewed from Wigner phase space

    DEFF Research Database (Denmark)

    Heim, D.M.; Schleich, W.P.; Alsing, P.M.

    2013-01-01

    We analyze the tunneling of a particle through a repulsive potential resulting from an inverted harmonic oscillator in the quantum mechanical phase space described by the Wigner function. In particular, we solve the partial differential equations in phase space determining the Wigner function...

  18. A Duty Cycle Space Vector Modulation Strategy for a Three-to-Five Phase Direct Matrix Converter

    Directory of Open Access Journals (Sweden)

    Rutian Wang

    2018-02-01

    Full Text Available The duty cycle space vector (DCSV modulation strategy is of universal significance, and the method can be utilized for different modulation approaches. In this paper, the vectors of input voltages and currents are equivalently represented by a complex two-dimensional space vector, and the vectors of output voltages and currents are equivalently represented by two two-dimensional space vectors. Then, input–output relationships in both the d1-q1 space and the d3-q3 space are obtained. Because the desired output voltages are only mapped onto a reference voltage space vector in the d1-q1 space, the reference in the d3-q3 space is regarded as zero, in order to reduce harmonics of output voltages to the greatest extent. Then, the duty cycle space vector modulation strategy of the three-to-five phase direct matrix converter (DMC is deduced. Considering the influence of the zero vector on system performance, the duty cycles are decomposed and recomposed to obtain the space vector pulse width modulation (SVPWM strategy based on the duty cycle space vector. Finally, the accuracy and feasibility of the theory are verified through experiments.

  19. Efficient characterization of phase space mapping in axially symmetric optical systems

    Science.gov (United States)

    Barbero, Sergio; Portilla, Javier

    2018-01-01

    Phase space mapping, typically between an object and image plane, characterizes an optical system within a geometrical optics framework. We propose a novel conceptual frame to characterize the phase mapping in axially symmetric optical systems for arbitrary object locations, not restricted to a specific object plane. The idea is based on decomposing the phase mapping into a set of bivariate equations corresponding to different values of the radial coordinate on a specific object surface (most likely the entrance pupil). These equations are then approximated through bivariate Chebyshev interpolation at Chebyshev nodes, which guarantees uniform convergence. Additionally, we propose the use of a new concept (effective object phase space), defined as the set of points of the phase space at the first optical element (typically the entrance pupil) that are effectively mapped onto the image surface. The effective object phase space provides, by means of an inclusion test, a way to avoid tracing rays that do not reach the image surface.

  20. Benchmarking of 3D space charge codes using direct phase space measurements from photoemission high voltage dc gun

    Directory of Open Access Journals (Sweden)

    Ivan V. Bazarov

    2008-10-01

    Full Text Available We present a comparison between space charge calculations and direct measurements of the transverse phase space of space charge dominated electron bunches from a high voltage dc photoemission gun followed by an emittance compensation solenoid magnet. The measurements were performed using a double-slit emittance measurement system over a range of bunch charge and solenoid current values. The data are compared with detailed simulations using the 3D space charge codes GPT and Parmela3D. The initial particle distributions were generated from measured transverse and temporal laser beam profiles at the photocathode. The beam brightness as a function of beam fraction is calculated for the measured phase space maps and found to approach within a factor of 2 the theoretical maximum set by the thermal energy and the accelerating field at the photocathode.

  1. Thim's Experiment and Exact Rotational Space-Time Transformations

    CERN Document Server

    Hsu, Leonardo

    2014-01-01

    Thim measured the transverse Doppler shift using a system consisting of a stationary antenna and pickup, in addition to a number of intermediate antennas mounted on the rim of a rotating disk. No such shift was detected, although the experiment should have had enough sensitivity to measure it, as predicted by the Lorentz transformations. However, using the Lorentz transformations to analyze the results of experiments involving circular motion, while commonly done, is inappropriate because such an analysis involves non-inertial frames, which are outside the range of validity of special relativity. In this paper, we re-analyze Thim's experiment using exact rotational space-time transformations, finding that his null result is consistent with theoretical predictions.

  2. Mid- and long-term runoff predictions by an improved phase-space reconstruction model.

    Science.gov (United States)

    Hong, Mei; Wang, Dong; Wang, Yuankun; Zeng, Xiankui; Ge, Shanshan; Yan, Hengqian; Singh, Vijay P

    2016-07-01

    In recent years, the phase-space reconstruction method has usually been used for mid- and long-term runoff predictions. However, the traditional phase-space reconstruction method is still needs to be improved. Using the genetic algorithm to improve the phase-space reconstruction method, a new nonlinear model of monthly runoff is constructed. The new model does not rely heavily on embedding dimensions. Recognizing that the rainfall-runoff process is complex, affected by a number of factors, more variables (e.g. temperature and rainfall) are incorporated in the model. In order to detect the possible presence of chaos in the runoff dynamics, chaotic characteristics of the model are also analyzed, which shows the model can represent the nonlinear and chaotic characteristics of the runoff. The model is tested for its forecasting performance in four types of experiments using data from six hydrological stations on the Yellow River and the Yangtze River. Results show that the medium-and long-term runoff is satisfactorily forecasted at the hydrological stations. Not only is the forecasting trend accurate, but also the mean absolute percentage error is no more than 15%. Moreover, the forecast results of wet years and dry years are both good, which means that the improved model can overcome the traditional ''wet years and dry years predictability barrier,'' to some extent. The model forecasts for different regions are all good, showing the universality of the approach. Compared with selected conceptual and empirical methods, the model exhibits greater reliability and stability in the long-term runoff prediction. Our study provides a new thinking for research on the association between the monthly runoff and other hydrological factors, and also provides a new method for the prediction of the monthly runoff. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Families of vector-like deformations of relativistic quantum phase spaces, twists and symmetries

    Science.gov (United States)

    Meljanac, Daniel; Meljanac, Stjepan; Pikutić, Danijel

    2017-12-01

    Families of vector-like deformed relativistic quantum phase spaces and corresponding realizations are analyzed. A method for a general construction of the star product is presented. The corresponding twist, expressed in terms of phase space coordinates, in the Hopf algebroid sense is presented. General linear realizations are considered and corresponding twists, in terms of momenta and Poincaré-Weyl generators or gl(n) generators are constructed and R-matrix is discussed. A classification of linear realizations leading to vector-like deformed phase spaces is given. There are three types of spaces: (i) commutative spaces, (ii) κ -Minkowski spaces and (iii) κ -Snyder spaces. The corresponding star products are (i) associative and commutative (but non-local), (ii) associative and non-commutative and (iii) non-associative and non-commutative, respectively. Twisted symmetry algebras are considered. Transposed twists and left-right dual algebras are presented. Finally, some physical applications are discussed.

  4. An equivalent ground thermal test method for single-phase fluid loop space radiator

    Directory of Open Access Journals (Sweden)

    Xianwen Ning

    2015-02-01

    Full Text Available Thermal vacuum test is widely used for the ground validation of spacecraft thermal control system. However, the conduction and convection can be simulated in normal ground pressure environment completely. By the employment of pumped fluid loops’ thermal control technology on spacecraft, conduction and convection become the main heat transfer behavior between radiator and inside cabin. As long as the heat transfer behavior between radiator and outer space can be equivalently simulated in normal pressure, the thermal vacuum test can be substituted by the normal ground pressure thermal test. In this paper, an equivalent normal pressure thermal test method for the spacecraft single-phase fluid loop radiator is proposed. The heat radiation between radiator and outer space has been equivalently simulated by combination of a group of refrigerators and thermal electrical cooler (TEC array. By adjusting the heat rejection of each device, the relationship between heat flux and surface temperature of the radiator can be maintained. To verify this method, a validating system has been built up and the experiments have been carried out. The results indicate that the proposed equivalent ground thermal test method can simulate the heat rejection performance of radiator correctly and the temperature error between in-orbit theory value and experiment result of the radiator is less than 0.5 °C, except for the equipment startup period. This provides a potential method for the thermal test of space systems especially for extra-large spacecraft which employs single-phase fluid loop radiator as thermal control approach.

  5. Theory of multiple phase separations in binary mixtures: Phase diagrams, thermodynamic properties, and comparisons with experiments

    Science.gov (United States)

    Goldstein, Raymond E.; Walker, James S.

    1983-02-01

    The lattice-gas models of phase separating binary liquid mixtures, introduced by Walker and Vause, are studied in detail and generalized within a high-temperature series expansion. This approximation allows for a straightforward study of rather complex, orientationally specific pair interactions, like those found in real systems. These theories can predict much of the complex miscibility phenomena often found in these mixtures, which are characterized by hydrogen-bonding interactions. Such phenomena include up to five critical solution points as a function of temperature. By comparisons with experiments, we determine the model parameters, thus mapping these experiments onto the global phase diagrams. These experiments include studies of the dependence of liquid/liquid miscibility on temperature, pressure, concentration of electrolytes, and addition of a dilute third component. Specifically, we make direct comparison with various experiments on the binary systems 2-butanol+H2O, 3-methyl pyridine+H2O(D2O), gylcerol +o- methoxy phenol and ethanol+H2O+electrolytes. Very simple and often easily interpreted trends in the parameters are found and quantitative agreement with experiments is possible with minimum parametric freedom. Explicit predictions of critical exponent renormalization in several systems are made. In addition, suggestions are made for a number of light scattering and specific heat experiments, some of which may demonstrate incipient critical behavior, such as the onset of long range correlations, in systems not undergoing phase separation.

  6. Space Station Freedom - Approaching the critical design phase

    Science.gov (United States)

    Kohrs, Richard H.; Huckins, Earle, III

    1992-01-01

    The status and future developments of the Space Station Freedom are discussed. To date detailed design drawings are being produced to manufacture SSF hardware. A critical design review (CDR) for the man-tended capability configuration is planned to be performed in 1993 under the SSF program. The main objective of the CDR is to enable the program to make a full commitment to proceed to manufacture parts and assemblies. NASA recently signed a contract with the Russian space company, NPO Energia, to evaluate potential applications of various Russian space hardware for on-going NASA programs.

  7. Experiences of the GDR in space sciences and technology

    Science.gov (United States)

    Stiller, H.; Knuth, R.; Bormann, P.

    Following a historical review of the first activities of GDR scientists in the fields of space research, especially on astronomical and geodetical satellite-observations and in atmospheric and magnetospheric research, the growing scientific and increasingly efficient technological and economic benefits of the cooperation of the Academy of sciences and other scientific and technological institutions of the GDR within the Intercosmos-programme are described. Especially, the experiences in connection with remote sensing, of the cooperation with countries as Cuba and the Peoples Republic of Vietnam and of the common USSR - GDR manned spaceflight are discussed under the viewpoint of the mutual interests of developing and developed countries in the fields of space science and technology.

  8. Interrelationship between Plasma Experiments in the Laboratory and in Space

    Energy Technology Data Exchange (ETDEWEB)

    Koepke, Mark E. [West Virginia Univ., Morgantown, WV (United States)

    2017-05-25

    Funds were expended to offset the travel costs of three students and three postdoctoral research associates to participate in and present work at the 2015 International Workshop on the Interrelationship between Plasma Experiments in the Laboratory and in Space (IPELS2015), 23-28 August 2015, Pitlochry, Scotland, UK. Selection was priority-ranked by lab-space engagement, first, and topic relevance, second. Supplementary selection preference was applied to under-represented populations, applicants lacking available travel-resources in their home research group, applicants unusually distant from the conference venue, and the impact of the applicant’s attendance in increasing the diversity of conference participation. One support letter per student was required. The letters described the specific benefit of IPELS2015 to the student dissertation or the postdoc career development, and document the evidence for the ordering criteria.

  9. FIRST experiment: Fragmentation of Ions Relevant for Space and Therapy

    Science.gov (United States)

    Agodi, C.; Abou-Haidar, Z.; Alvarez, M. A. G.; Aumann, T.; Balestra, F.; Battistoni, G.; Bocci, A.; Bohlen, T. T.; Bondì, M.; Boudard, A.; Brunetti, A.; Carpinelli, M.; Cappuzzello, F.; Cavallaro, M.; Carbone, D.; Cirrone, G. A. P.; Cortes-Giraldo, M. A.; Cuttone, G.; De Napoli, M.; Durante, M.; Fernandez-Garcia, J. P.; Finck, C.; Foti, A.; Gallardo, M. I.; Golosio, B.; Iarocci, E.; Iazzi, F.; Ickert, G.; Introzzi, R.; Juliani, D.; Krimmer, J.; Kurz, N.; Labalme, M.; Lavagno, A.; Leifels, Y.; Le Fevre, A.; Leray, S.; Marchetto, F.; Monaco, V.; Morone, M. C.; Nicolosi, D.; Oliva, P.; Paoloni, A.; Patera, V.; Piersanti, L.; Pleskac, R.; Quesada, J. M.; Randazzo, N.; Romano, F.; Rossi, D.; Rosso, V.; Rousseau, M.; Sacchi, R.; Sala, P.; Sarti, A.; Scheidenberger, C.; Schuy, C.; Sciubba, A.; Sfienti, C.; Simon, H.; Sipala, V.; Spiriti, E.; Stuttge, L.; Tropea, S.; Younis, H.

    2013-03-01

    Nuclear fragmentation processes are relevant in different fields of basic research and applied physics and are of particular interest for tumor therapy and for space radiation protection applications. The FIRST (Fragmentation of Ions Relevant for Space and Therapy) experiment at SIS accelerator of GSI laboratory in Darmstadt, has been designed for the measurement of different ions fragmentation cross sections at different energies between 100 and 1000 MeV/nucleon. The experiment is performed by an international collaboration made of institutions from Germany, France, Italy and Spain. The experimental apparatus is partly based on an already existing setup made of the ALADIN magnet, the MUSIC IV TPC, the LAND2 neutron detector and the TOFWALL scintillator TOF system, integrated with newly designed detectors in the interaction Region (IR) around the carbon removable target: a scintillator Start Counter, a Beam Monitor drift chamber, a silicon Vertex Detector and a Proton Tagger for detection of light fragments emitted at large angles (KENTROS). The scientific program of the FIRST experiment started on summer 2011 with the study of the 400 MeV/nucleon 12C beam fragmentation on thin (8mm) carbon target.

  10. Space Experiment on Tuber Development and Starch Accumulation for CELSS

    Science.gov (United States)

    Tibbitts,Theodore W.; Croxdale, Judith C.; Brown, Christopher S.

    1997-01-01

    Potato explants (leaf, small stem section, and axillary bud), flown on STS-73, developed tubers of 1.5 cm diameter and 1.7 g mass during the 16 day period of spaceflight. The experiment was undertaken in the ASTROCULTURE(Trademark) experiment package under controlled temperature, humidity, lighting, and carbon dioxide concentrations. The tubers formed in the explant system under microgravity had the same gross morphology, the same anatomical configuration of cells and tissues, and the same sizes, shapes, and surface character of starch granules as tubers formed in a 1 g environment. The total accumulation of starch and other energy containing compounds was singular in space flight and ground control tubers. Enzyme activity of starch synthase, starch phosphorylase, and total hydrolase was similar in spaceflight and ground controls but activity of ADP-glucose pyrophosphorylase was reduced in the spaceflight tuber tissue. This experiment documented that potatoes will metabolize and accumulate starch as effectively in spaceflight as on the ground and thus this data provides the potential for effective utilization of potatoes in life support systems of space bases.

  11. Artificial ionospheric modification: The Metal Oxide Space Cloud experiment

    Science.gov (United States)

    Caton, Ronald G.; Pedersen, Todd R.; Groves, Keith M.; Hines, Jack; Cannon, Paul S.; Jackson-Booth, Natasha; Parris, Richard T.; Holmes, Jeffrey M.; Su, Yi-Jiun; Mishin, Evgeny V.; Roddy, Patrick A.; Viggiano, Albert A.; Shuman, Nicholas S.; Ard, Shaun G.; Bernhardt, Paul A.; Siefring, Carl L.; Retterer, John; Kudeki, Erhan; Reyes, Pablo M.

    2017-05-01

    Clouds of vaporized samarium (Sm) were released during sounding rocket flights from the Reagan Test Site, Kwajalein Atoll in May 2013 as part of the Metal Oxide Space Cloud (MOSC) experiment. A network of ground-based sensors observed the resulting clouds from five locations in the Republic of the Marshall Islands. Of primary interest was an examination of the extent to which a tailored radio frequency (RF) propagation environment could be generated through artificial ionospheric modification. The MOSC experiment consisted of launches near dusk on two separate evenings each releasing 6 kg of Sm vapor at altitudes near 170 km and 180 km. Localized plasma clouds were generated through a combination of photoionization and chemi-ionization (Sm + O → SmO+ + e-) processes producing signatures visible in optical sensors, incoherent scatter radar, and in high-frequency (HF) diagnostics. Here we present an overview of the experiment payloads, document the flight characteristics, and describe the experimental measurements conducted throughout the 2 week launch window. Multi-instrument analysis including incoherent scatter observations, HF soundings, RF beacon measurements, and optical data provided the opportunity for a comprehensive characterization of the physical, spectral, and plasma density composition of the artificial plasma clouds as a function of space and time. A series of companion papers submitted along with this experimental overview provide more detail on the individual elements for interested readers.

  12. Space Shuttle Boundary Layer Transition Flight Experiment Ground Testing Overview

    Science.gov (United States)

    Berger, Karen T.; Anderson, Brian P.; Campbell, Charles H.

    2014-01-01

    In support of the Boundary Layer Transition (BLT) Flight Experiment (FE) Project in which a manufactured protuberance tile was installed on the port wing of Space Shuttle Orbiter Discovery for STS-119, STS- 128, STS-131 and STS-133 as well as Space Shuttle Orbiter Endeavour for STS-134, a significant ground test campaign was completed. The primary goals of the test campaign were to provide ground test data to support the planning and safety certification efforts required to fly the flight experiment as well as validation for the collected flight data. These test included Arcjet testing of the tile protuberance, aerothermal testing to determine the boundary layer transition behavior and resultant surface heating and planar laser induced fluorescence (PLIF) testing in order to gain a better understanding of the flow field characteristics associated with the flight experiment. This paper provides an overview of the BLT FE Project ground testing. High-level overviews of the facilities, models, test techniques and data are presented, along with a summary of the insights gained from each test.

  13. Deep-Space Ka-Band Flight Experience

    Science.gov (United States)

    Morabito, D. D.

    2017-11-01

    Lower frequency bands have become more congested in allocated bandwidth as there is increased competition between flight projects and other entities. Going to higher frequency bands offers significantly more bandwidth, allowing for the use of much higher data rates. However, Ka-band is more susceptible to weather effects than lower frequency bands currently used for most standard downlink telemetry operations. Future or prospective flight projects considering deep-space Ka-band (32-GHz) telemetry data links have expressed an interest in understanding past flight experience with received Ka-band downlink performance. Especially important to these flight projects is gaining a better understanding of weather effects from the experience of current or past missions that operated Ka-band radio systems. We will discuss the historical flight experience of several Ka-band missions starting from Mars Observer in 1993 up to present-day deep-space missions such as Kepler. The study of historical Ka-band flight experience allows one to recommend margin policy for future missions. Of particular interest, we will review previously reported-on flight experience with the Cassini spacecraft Ka-band radio system that has been used for radio science investigations as well as engineering studies from 2004 to 2015, when Cassini was in orbit around the planet Saturn. In this article, we will focus primarily on the Kepler spacecraft Ka-band link, which has been used for operational telemetry downlink from an Earth trailing orbit where the spacecraft resides. We analyzed the received Ka-band signal level data in order to characterize link performance over a wide range of weather conditions and as a function of elevation angle. Based on this analysis of Kepler and Cassini flight data, we found that a 4-dB margin with respect to adverse conditions ensures that we achieve at least a 95 percent data return.

  14. Theory of Superthermal, Wide, Electron Phase-Space Holes and Bipolar Fields*

    Science.gov (United States)

    Goldman, M. V.; Newman, D. L.

    2008-12-01

    Laboratory reconnection experiments [1] and recent magnetospheric spacecraft observations [2] are beginning to find bipolar fields with a spatial half-width equal to many Debye lengths (10 or more) traveling at high speeds (faster than the thermal velocity of the bulk of electrons). Electron phase-space hole solutions of the nonlinear Poisson-Vlasov equations (stationary in a frame co-moving with the hole) are constructed analytically with these properties by assuming there is secondary component of the electron distribution. This component can be a tail on the electron distribution or a beam. The hole velocity will be close to the velocity at the end of the tail or the velocity of the beam, provided the ions are moving with sufficient velocity in the frame of the hole. Vlasov simulations are used to study accessibility and stability of these solutions. * Work supported by DOE, NASA, and NSF [1]W. Fox, M. Porkolab, J. Egedal, N. Katz, A. Le, and A. Vrublevskis, "Observation of electron phase-space holes during magnetic reconnection in the Versatile Toroidal Facility," Abstract GP6.00029, 50th Annual Meeting of the Division of Plasma Physics, American Physical Society (Dallas, Nov.~2008). [2] R. E. Ergun and J. Tao, private communication.

  15. Laser Calibration Experiment for Small Objects in Space

    Science.gov (United States)

    Campbell, Jonathan; Ayers, K.; Carreras, R.; Carruth, R.; Freestone, T.; Sharp, J.; Rawleigh, A.; Brewer, J.; Schrock, K.; Bell, L.; hide

    2001-01-01

    The Air Force Research Laboratory/Directed Energy Directorate (AFRL/DE) and NASA/Marshall Space Flight Center (MSFC) are looking at a series of joint laser space calibration experiments using the 12J 15Hz CO2 High Performance CO2 Ladar Surveillance Sensor (FU-CLASS) system on the 3.67 meter aperture Advanced Electro-Optics System (AEOS). The objectives of these experiments are to provide accurate range and signature measurements of calibration spheres, demonstrate high resolution tracking capability of small objects, and support NASA in technology development and tracking projects. Ancillary benefits include calibrating radar and optical sites, completing satellite conjunction analyses, supporting orbital perturbations analyses, and comparing radar and optical signatures. In the first experiment, a Global Positioning System (GPS)/laser beacon instrumented microsatellite about 25 cm in diameter will be deployed from a Space Shuttle Hitchhiker canister or other suitable launch means. Orbiting in low earth orbit, the microsatellite will pass over AEOS on the average of two times per 24-hour period. An onboard orbit propagator will activate the GPS unit and a visible laser beacon at the appropriate times. The HI-CLASS/AEOS system will detect the microsatellite as it rises above the horizon, using GPS-generated acquisition vectors. The visible laser beacon will be used to fine-tune the tracking parameters for continuous ladar data measurements throughout the pass. This operational approach should maximize visibility to the ground-based laser while allowing battery life to be conserved, thus extending the lifetime of the satellite. GPS data will be transmitted to the ground providing independent location information for the microsatellite down to sub-meter accuracies.

  16. Multimegawatt space nuclear power supply: Phase 1, Final report

    Energy Technology Data Exchange (ETDEWEB)

    1989-02-17

    The Phase 2 program objectives are to (1) demonstrate concept feasibility, (2) develop a preliminary design, and (3) complete Phase 3 engineering development and ground test plans. The approach to accomplish these objectives is to prove technical feasibility of our baseline design early in the program while maintaining flexibility to easily respond to changing requirements and advances in technology. This approach recognizes that technology is advancing rapidly while the operational phase MSNPS is 15 to 20 years in the future. This plan further recognizes that the weapons platform and Advanced Launch System (ALS) are in very early program definition stages; consequently, their requirements, interfaces, and technological basis will evolve. This document outlines the Phase 2 plan along with task scheduling of the various program aspects.

  17. Capacity building in emerging space nations: Experiences, challenges and benefits

    Science.gov (United States)

    Jason, Susan; da Silva Curiel, Alex; Liddle, Doug; Chizea, Francis; Leloglu, Ugur Murat; Helvaci, Mustafa; Bekhti, Mohammed; Benachir, Djouad; Boland, Lee; Gomes, Luis; Sweeting, Martin

    2010-09-01

    This paper focuses on ways in which space is being used to build capacity in science and technology in order to: Offer increasing support for national and global solutions to current and emerging problems including: how to improve food security; resource management; understanding the impacts of climate change and how to deal with them; improving disaster mitigation, management and response. Support sustainable economic development. We present some of the experiences, lessons learned and benefits gained in capacity building projects undertaken by Surrey Satellite Technology Ltd. and our partners from developing and mature space nations. We focus on the Turkish, Algerian and Nigerian know-how and technology transfer programmes which form part of the first Disaster Monitoring Constellation (DMC) in orbit. From the lessons learned on Surrey's know-how and technology transfer partnership programmes, it is clear that space technology needs to be implemented responsibly as part of a long-term capacity building plan to be a sustainable one. It needs to be supported with appropriate policy and legal frameworks, institutional development, including community participation, human resources development and strengthening of managerial systems. In taking this on board, DMC has resulted in a strong international partnership combining national objectives, humanitarian aid and commerce. The benefits include: Ownership of space-based and supporting ground assets with low capital expenditure that is in line with national budgets of developing nations. Ownership of data and control over data acquisition. More for the money via collaborative consortium. Space related capacity building in organisations and nations with the goal of sustainable development. Opportunities for international collaboration, including disaster management and relief.

  18. Microbe space exposure experiment at International Space Station (ISS) proposed in "Tanpopo" mission

    Science.gov (United States)

    Yokobori, Shin-Ichi; Yang, Yinjie; Sugino, Tomohiro; Kawaguchi, Yuko; Yoshida, Satoshi; Hashimoto, Hirofumi; Narumi, Issay; Kobayashi, Kensei; Yamagishi, Akihiko

    Microbes have been collected from high altitude using balloons, aircraft and meteorological rockets since 1936. Spore forming fungi and Bacilli, and Micrococci (probably Deinococci) have been isolated in these experiments. These spores and Deinococci are known by their extremely high resistance against UV, gamma ray, and other radiation. We have also collected microorganisms at high altitude by using an aircraft and balloons. We collected two novel species of the genus Deinococcus, one from top of troposphere (D. aerius) and the other from bottom of stratosphere (D. aetherius). These two species showed high resistance comparable with D. radiodurans R1 to the UV and radiation such as gamma ray. If microbes could be found present even at the higher altitude of low earth orbit (400km), the fact would endorse the possible interplanetary migration of terrestrial life. Indeed, to explain how organisms on the Earth were originated at the quite early stage of the history of Earth, panspermia hypothesis was proposed. Recent findings of the Martian meteorite suggested possible existence of extraterrestrial life, and interplanetary migration of life as well. We proposed the "Tanpopo" mission to examine possible interplanetary migration of microbes, and organic compounds on Japan Experimental Module (JEM) of the International Space Station (ISS). Two of six subthemes in Tanpopo are on the possible interplanetary migration of microbes — capture experiment of microbes at the ISS orbit and space exposure experiment of microbes. In this paper, we focus on the space exposure experiment of microbes. In our proposal, microbes will be exposed to the space environment with/without model-clay materials that might protect microbes from vacuum UV and cosmic rays. Spore of Bacillus sp., and vegetative cells of D. radiodurans and our novel deinococcal species isolated from high altitude are candidates for the exposure experiment. In preliminary experiments, clay-materials tend to increase

  19. GeneLab Phase 2: Integrated Search Data Federation of Space Biology Experimental Data

    Science.gov (United States)

    Tran, P. B.; Berrios, D. C.; Gurram, M. M.; Hashim, J. C. M.; Raghunandan, S.; Lin, S. Y.; Le, T. Q.; Heher, D. M.; Thai, H. T.; Welch, J. D.; hide

    2016-01-01

    The GeneLab project is a science initiative to maximize the scientific return of omics data collected from spaceflight and from ground simulations of microgravity and radiation experiments, supported by a data system for a public bioinformatics repository and collaborative analysis tools for these data. The mission of GeneLab is to maximize the utilization of the valuable biological research resources aboard the ISS by collecting genomic, transcriptomic, proteomic and metabolomic (so-called omics) data to enable the exploration of the molecular network responses of terrestrial biology to space environments using a systems biology approach. All GeneLab data are made available to a worldwide network of researchers through its open-access data system. GeneLab is currently being developed by NASA to support Open Science biomedical research in order to enable the human exploration of space and improve life on earth. Open access to Phase 1 of the GeneLab Data Systems (GLDS) was implemented in April 2015. Download volumes have grown steadily, mirroring the growth in curated space biology research data sets (61 as of June 2016), now exceeding 10 TB/month, with over 10,000 file downloads since the start of Phase 1. For the period April 2015 to May 2016, most frequently downloaded were data from studies of Mus musculus (39) followed closely by Arabidopsis thaliana (30), with the remaining downloads roughly equally split across 12 other organisms (each 10 of total downloads). GLDS Phase 2 is focusing on interoperability, supporting data federation, including integrated search capabilities, of GLDS-housed data sets with external data sources, such as gene expression data from NIHNCBIs Gene Expression Omnibus (GEO), proteomic data from EBIs PRIDE system, and metagenomic data from Argonne National Laboratory's MG-RAST. GEO and MG-RAST employ specifications for investigation metadata that are different from those used by the GLDS and PRIDE (e.g., ISA-Tab). The GLDS Phase 2 system

  20. ONKALO POSE experiment. Phase 1 and 2: execution and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, E. [Saanio and Riekkola Oy, Helsinki (Finland); Siren, T. [Posiva Oy, Helsinki (Finland); Hakala, M. [KMS-Hakala Oy, Nokia (Finland); Kantia, P. [Geofcon Oy, Rovaniemi (Finland)

    2014-02-15

    Posiva has conducted in the ONKALO rock characterisation facility during 2010 - 2011 an in situ experiment named POSE (Posiva's Olkiluoto Spalling Experiment). The POSE experiment had three objectives: to establish the in situ spalling/damage strength of Olkiluoto migmatitic gneiss, to establish the state of in situ stress at the -345 m depth level, and to act as a Prediction-Outcome (P-O) exercise. The POSE experiment consisted of drilling with full-face boring machine two near fullscale deposition holes, diameter 1.52 m (compared to 1.75 m for the actual deposition holes), to a depth of 7.2 m, leaving a 0.9 m pillar between the holes. The holes were planned to be located in such way that maximum excavation-induced stresses could act in the pillar and damage could then take place. Boring of the two holes in 2010 was called Phase 1 (Pillar test). This was followed in 2011 by Phase 2 (Pillar heating test) where four heaters with a length of 7.5 m heated the test area to increase the stresses around the experimental holes. In the heating phase the other hole was back-filled with sand. The test was extensively monitored during the execution using temperature monitoring, strain gauge monitoring, video monitoring, microseismic monitoring and pressure monitoring. In addition, the holes were after the test measured using ground penetration radar (GPR) and 3D photogrammetry for detailed modelling. The outcomes from the test showed that no damage, except for three opened/sheared fractures, was noticed during the boring of the holes (Phase 1). Surface damage was, though, induced by heating (Phase 2). The damage was well localized around the holes and controlled by the foliation (mica rich layers) and rock type contacts which were known to be relatively weak. Surface type failures were not observed in the gneiss, but it was noticed in limited areas in the pegmatite-granite. The depths of the damaged areas due to heating were less than 100 mm. The depths and sizes of the

  1. Deep Space Networking Experiments on the EPOXI Spacecraft

    Science.gov (United States)

    Jones, Ross M.

    2011-01-01

    NASA's Space Communications & Navigation Program within the Space Operations Directorate is operating a program to develop and deploy Disruption Tolerant Networking [DTN] technology for a wide variety of mission types by the end of 2011. DTN is an enabling element of the Interplanetary Internet where terrestrial networking protocols are generally unsuitable because they rely on timely and continuous end-to-end delivery of data and acknowledgments. In fall of 2008 and 2009 and 2011 the Jet Propulsion Laboratory installed and tested essential elements of DTN technology on the Deep Impact spacecraft. These experiments, called Deep Impact Network Experiment (DINET 1) were performed in close cooperation with the EPOXI project which has responsibility for the spacecraft. The DINET 1 software was installed on the backup software partition on the backup flight computer for DINET 1. For DINET 1, the spacecraft was at a distance of about 15 million miles (24 million kilometers) from Earth. During DINET 1 300 images were transmitted from the JPL nodes to the spacecraft. Then, they were automatically forwarded from the spacecraft back to the JPL nodes, exercising DTN's bundle origination, transmission, acquisition, dynamic route computation, congestion control, prioritization, custody transfer, and automatic retransmission procedures, both on the spacecraft and on the ground, over a period of 27 days. The first DINET 1 experiment successfully validated many of the essential elements of the DTN protocols. DINET 2 demonstrated: 1) additional DTN functionality, 2) automated certain tasks which were manually implemented in DINET 1 and 3) installed the ION SW on nodes outside of JPL. DINET 3 plans to: 1) upgrade the LTP convergence-layer adapter to conform to the international LTP CL specification, 2) add convergence-layer "stewardship" procedures and 3) add the BSP security elements [PIB & PCB]. This paper describes the planning and execution of the flight experiment and the

  2. [Growth and development of plants in a sequence of generations under the conditions of space flight (experiment Greenhouse-3)

    Science.gov (United States)

    Levinskikh, M. A.; Sychev, V. N.; Signalova, O. B.; Derendiaeva, T. A.; Podol'skii, I. G.; Masgreiv, M. E.; Bingheim, G. E.; Musgrave, M. E. (Principal Investigator); Campbell, W. F. (Principal Investigator)

    2001-01-01

    The purpose was to study characteristic features of growth and development of several plant generations in space flight in experiment GREENHOUSE-3 as a part of the Russian-US space research program MIR/NASA in 1997. The experiment consisted of cultivation of Brassica rapa L. in board greenhouse Svet. Two vegetative cycles were fully completed and the third vegetation was terminated on day 13 on the phase of budding. The total duration of the space experiment was 122 days, i.e. same as in the ground controls. In the experiment with Brassica rapa L. viable seeds produced by the first crop were planted in space flight and yielded next crop. Crops raised from the ground and space seeds were found to differ in height and number of buds. Both parameters were lowered in the plants grown from the space seeds. The prime course for smaller size and reduced organogenic potential of plantTs reproductive system seems to be a less content of nutrients in seeds that had matured in the space flight. Experiment GREENHOUSE-3 demonstrated principle feasibility of plant reproduction in space greenhouse from seeds developed in microgravity.

  3. Experience from the Student Programme REXUS/BEXUS: A Stepping Stone to a Space Career

    Science.gov (United States)

    Berquand, A.

    2015-09-01

    The aim of this paper is to give an inside view to the REXUS/BEXUS programme from the perspective of a student who has been involved in the project. Each year, the German Aerospace Center (DLR) and the Swedish National Space Board (SNSB), in cooperation with the European Space Agency (ESA), offer the opportunity to European University Students to fly an experiment on board sounding rockets or stratospheric balloons in the frame of the REXUS/BEXUS programme. From December 2012 to May 2014 a team of master students from KTH, the Royal Institute of Technology, worked on ISAAC project, an atmospheric experiment launched on board REXUS 15. The author was part of this student team and was involved in the whole process of the ISAAC project from design building and testing phases to the launch campaign and results analysis. The points raised in this article were presented on the occasion of a keynote speech during the 22nd ESA Symposium on European Rocket and Balloon Programmes and Related Research, in Tromsø (Norway) from the 7th to the 12th ofJune 2015. The aim of this presentation was to demonstrate the benefits of hands-on Education programme at University level. In addition to the research opportunities, future space engineers and scientists can profit from a first practical experience under the supervision of experimented experts. The results of the ISAAC project were also presented in the frame of this conference [1].

  4. Experimenting Galileo on Board the International Space Station

    Science.gov (United States)

    Fantinato, Samuele; Pozzobon, Oscar; Sands, Obed S.; Welch, Bryan W.; Clapper, Carolyn J.; Miller, James J.; Gamba, Giovanni; Chiara, Andrea; Montagner, Stefano; Giordano, Pietro; hide

    2016-01-01

    The SCaN Testbed is an advanced integrated communications system and laboratory facility installed on the International Space Station (ISS) in 2012. The testbed incorporates a set of new generation of Software Defined Radio (SDR) technologies intended to allow researchers to develop, test, and demonstrate new communications, networking, and navigation capabilities in the actual environment of space. Qascom, in cooperation with ESA and NASA, is designing a Software Defined Radio GalileoGPS Receiver capable to provide accurate positioning and timing to be installed on the ISS SCaN Testbed. The GalileoGPS waveform will be operated in the JPL SDR that is constituted by several hardware components that can be used for experimentations in L-Band and S-Band. The JPL SDR includes an L-Band Dorne Margolin antenna mounted onto a choke ring. The antenna is connected to a radio front end capable to provide one bit samples for the three GNSS frequencies (L1, L2 and L5) at 38 MHz, exploiting the subharmonic sampling. The baseband processing is then performed by an ATMEL AT697 processor (100 MIPS) and two Virtex 2 FPGAs. The JPL SDR supports the STRS (Space Telecommunications Radio System) that provides common waveform software interfaces, methods of instantiation, operation, and testing among different compliant hardware and software products. The standard foresees the development of applications that are modular, portable, reconfigurable, and reusable. The developed waveform uses the STRS infrastructure-provided application program interfaces (APIs) and services to load, verify, execute, change parameters, terminate, or unload an application. The project is divided in three main phases. 1)Design and Development of the GalileoGPS waveform for the SCaN Testbed starting from Qascom existing GNSS SDR receiver. The baseline design is limited to the implementation of the single frequency Galileo and GPS L1E1 receiver even if as part of the activity it will be to assess the

  5. Equilibrium Phase Behavior of a Continuous-Space Microphase Former.

    Science.gov (United States)

    Zhuang, Yuan; Zhang, Kai; Charbonneau, Patrick

    2016-03-04

    Periodic microphases universally emerge in systems for which short-range interparticle attraction is frustrated by long-range repulsion. The morphological richness of these phases makes them desirable material targets, but our relatively coarse understanding of even simple models hinders controlling their assembly. We report here the solution of the equilibrium phase behavior of a microscopic microphase former through specialized Monte Carlo simulations. The results for cluster crystal, cylindrical, double gyroid, and lamellar ordering qualitatively agree with a Landau-type free energy description and reveal the nontrivial interplay between cluster, gel, and microphase formation.

  6. Ultramylonite generation via phase mixing in high-strain experiments

    Science.gov (United States)

    Cross, A. J.; Skemer, P.

    2017-03-01

    Dynamic recrystallization and phase mixing are considered to be important processes in ductile shear zone formation, as they collectively enable a permanent transition to the strain-weakening, grain-size sensitive deformation regime. While dynamic recrystallization is well understood, the underlying physical processes and timescales required for phase mixing remain enigmatic. Here, we present results from high-strain phase mixing experiments on calcite-anhydrite composites. A poorly mixed starting material was synthesized from fine-grained calcite and anhydrite powders. Samples were deformed in the Large Volume Torsion apparatus at 500°C and shear strain rates of 5 × 10-5 to 5 × 10-4 s-1, to finite shear strains of up to γ = 57. Microstructural evolution is quantified through analysis of backscattered electron images and electron backscatter diffraction data. During deformation, polycrystalline domains of the individual phases are geometrically stretched and thinned, causing an increase in the spatial density of interphase boundaries. At moderate shear strains (γ ≥ 6), domains are so severely thinned that they become "monolayers" of only one or two grain's width and form a thin compositional layering. Monolayer formation is accompanied by a critical increase in the degree of grain boundary pinning and, consequently, grain-size reduction below the theoretical limit established by the grain-size piezometer or deformation mechanism field boundary. Ultimately, monolayers neck and disaggregate at high strains (17 <γ <57) to complete the phase mixing process. This "geometric" phase mixing mechanism is consistent with observations of mylonites, where layer (i.e., foliation) formation is associated with strain localization, and layers are ultimately destroyed at the mylonite-ultramylonite transition.

  7. Laboratory observation of electron phase-space holes during magnetic reconnection.

    Science.gov (United States)

    Fox, W; Porkolab, M; Egedal, J; Katz, N; Le, A

    2008-12-19

    We report the observation of large-amplitude, nonlinear electrostatic structures, identified as electron phase-space holes, during magnetic reconnection experiments on the Versatile Toroidal Facility at MIT. The holes are positive electric potential spikes, observed on high-bandwidth ( approximately 2 GHz) Langmuir probes. Investigations with multiple probes establish that the holes travel at or above the electron thermal speed and have a three-dimensional, approximately spherical shape, with a scale size approximately 2 mm. This corresponds to a few electron gyroradii, or many tens of Debye lengths, which is large compared to holes considered in simulations and observed by satellites, whose length scale is typically only a few Debye lengths. Finally, a statistical study over many discharges confirms that the holes appear in conjunction with the large inductive electric fields and the creation of energetic electrons associated with the magnetic energy release.

  8. Transverse emittance and phase space program developed for use at the Fermilab A0 Photoinjector

    Energy Technology Data Exchange (ETDEWEB)

    Thurman-Keup, R.; Johnson, A.S.; Lumpkin, A.H.; Ruan, J.; /Fermilab

    2011-03-01

    The Fermilab A0 Photoinjector is a 16 MeV high intensity, high brightness electron linac developed for advanced accelerator R&D. One of the key parameters for the electron beam is the transverse beam emittance. Here we report on a newly developed MATLAB based GUI program used for transverse emittance measurements using the multi-slit technique. This program combines the image acquisition and post-processing tools for determining the transverse phase space parameters with uncertainties. An integral part of accelerator research is a measurement of the beam phase space. Measurements of the transverse phase space can be accomplished by a variety of methods including multiple screens separated by drift spaces, or by sampling phase space via pepper pots or slits. In any case, the measurement of the phase space parameters, in particular the emittance, can be drastically simplified and sped up by automating the measurement in an intuitive fashion utilizing a graphical interface. At the A0 Photoinjector (A0PI), the control system is DOOCS, which originated at DESY. In addition, there is a library for interfacing to MATLAB, a graphically capable numerical analysis package sold by The Mathworks. It is this graphical package which was chosen as the basis for a graphical phase space measurement system due to its combination of analysis and display capabilities.

  9. On phase-space representations of quantum mechanics using ...

    Indian Academy of Sciences (India)

    2016-07-16

    -space wave functions using the Glauber coherent states [2,23–25] and the Husimi amplitude, 〈z | (t)〉. Thus, in order to put into con- text the present paper, some previous literature in this area of research (`a la Bargmann) will ...

  10. Deep Space Habitat Concept of Operations for Transit Mission Phases

    Science.gov (United States)

    Hoffman, Stephen J.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) has begun evaluating various mission and system components of possible implementations of what the U.S. Human Spaceflight Plans Committee (also known as the Augustine Committee) has named the flexible path (Anon., 2009). As human spaceflight missions expand further into deep space, the duration of these missions increases to the point where a dedicated crew habitat element appears necessary. There are several destinations included in this flexible path a near Earth asteroid (NEA) mission, a Phobos/Deimos (Ph/D) mission, and a Mars surface exploration mission that all include at least a portion of the total mission in which the crew spends significant periods of time (measured in months) in the deep space environment and are thus candidates for a dedicated habitat element. As one facet of a number of studies being conducted by the Human Spaceflight Architecture Team (HAT) a workshop was conducted to consider how best to define and quantify habitable volume for these future deep space missions. One conclusion reached during this workshop was the need for a description of the scope and scale of these missions and the intended uses of a habitat element. A group was set up to prepare a concept of operations document to address this need. This document describes a concept of operations for a habitat element used for these deep space missions. Although it may eventually be determined that there is significant overlap with this concept of operations and that of a habitat destined for use on planetary surfaces, such as the Moon and Mars, no such presumption is made in this document.

  11. Study of a measurement of beam distribution on the phase space in the space charge dominant region

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Masahiro [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1998-06-01

    Beam distribution on the phase space which is figured by the emittance and Twiss parameters is one of the most important parameters when applications and performance of accelerator are studied. In the high energy region where the space charge effect is week, the emittance is measured by a quadrupole magnet and in the space charge dominant region, the pepper-pot technique is used. I studied a method to measure the beam distribution on the phase space by magnetic lenses in the space charge dominant region. In this method, an initial beam distribution is figured by parameters such as a momentum spread, a waist position and a beam radius at the exit of gun instead of Twiss parameters. And the beam trajectory and radius are calculated by a new simulation code instead of transfer matrix because transfer matrix can not be used in the space charge dominant region. I developed a new one dimensional simulation code. In this code, when the space charge force is calculated, a mesh size is changed automatically according to the beam radius in order to reduce the calculation error. The relations between the beam radius and strength of the magnetic lenses were calculated by this simulation code. The results show that the waist position and the beam radius at the exit of gun can be estimated from those relations. (author)

  12. Phase space investigation of the lithium amide halides

    Energy Technology Data Exchange (ETDEWEB)

    Davies, Rosalind A. [Hydrogen Storage Chemistry Group, School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Hydrogen and Fuel Cell Group, School of Chemical Engineering, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Hewett, David R.; Korkiakoski, Emma [Hydrogen Storage Chemistry Group, School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Thompson, Stephen P. [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Anderson, Paul A., E-mail: p.a.anderson@bham.ac.uk [Hydrogen Storage Chemistry Group, School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2015-10-05

    Highlights: • The lower limits of halide incorporation in lithium amide have been investigated. • The only amide iodide stoichiometry observed was Li{sub 3}(NH{sub 2}){sub 2}I. • Solid solutions were observed in both the amide chloride and amide bromide systems. • A 46% reduction in chloride content resulted in a new phase: Li{sub 7}(NH{sub 2}){sub 6}Cl. • New low-chloride phase maintained improved H{sub 2} desorption properties of Li{sub 4}(NH{sub 2}){sub 3}Cl. - Abstract: An investigation has been carried out into the lower limits of halide incorporation in lithium amide (LiNH{sub 2}). It was found that the lithium amide iodide Li{sub 3}(NH{sub 2}){sub 2}I was unable to accommodate any variation in stoichiometry. In contrast, some variation in stoichiometry was accommodated in Li{sub 7}(NH{sub 2}){sub 6}Br, as shown by a decrease in unit cell volume when the bromide content was reduced. The amide chloride Li{sub 4}(NH{sub 2}){sub 3}Cl was found to adopt either a rhombohedral or a cubic structure depending on the reaction conditions. Reduction in chloride content generally resulted in a mixture of phases, but a new rhombohedral phase with the stoichiometry Li{sub 7}(NH{sub 2}){sub 6}Cl was observed. In comparison to LiNH{sub 2}, this new low-chloride phase exhibited similar improved hydrogen desorption properties as Li{sub 4}(NH{sub 2}){sub 3}Cl but with a much reduced weight penalty through addition of chloride. Attempts to dope lithium amide with fluoride ions have so far proved unsuccessful.

  13. Experiences with integral microelectronics on smart structures for space

    Science.gov (United States)

    Nye, Ted; Casteel, Scott; Navarro, Sergio A.; Kraml, Bob

    1995-05-01

    One feature of a smart structure implies that some computational and signal processing capability can be performed at a local level, perhaps integral to the controlled structure. This requires electronics with a minimal mechanical influence regarding structural stiffening, heat dissipation, weight, and electrical interface connectivity. The Advanced Controls Technology Experiment II (ACTEX II) space-flight experiments implemented such a local control electronics scheme by utilizing composite smart members with integral processing electronics. These microelectronics, tested to MIL-STD-883B levels, were fabricated with conventional thick film on ceramic multichip module techniques. Kovar housings and aluminum-kapton multilayer insulation was used to protect against harsh space radiation and thermal environments. Development and acceptance testing showed the electronics design was extremely robust, operating in vacuum and at temperature range with minimal gain variations occurring just above room temperatures. Four electronics modules, used for the flight hardware configuration, were connected by a RS-485 2 Mbit per second serial data bus. The data bus was controlled by Actel field programmable gate arrays arranged in a single master, four slave configuration. An Intel 80C196KD microprocessor was chosen as the digital compensator in each controller. It was used to apply a series of selectable biquad filters, implemented via Delta Transforms. Instability in any compensator was expected to appear as large amplitude oscillations in the deployed structure. Thus, over-vibration detection circuitry with automatic output isolation was incorporated into the design. This was not used however, since during experiment integration and test, intentionally induced compensator instabilities resulted in benign mechanical oscillation symptoms. Not too surprisingly, it was determined that instabilities were most detectable by large temperature increases in the electronics, typically

  14. Compendium of Phase-I Mini-SHINE Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Youker, Amanda J. [Argonne National Lab. (ANL), Argonne, IL (United States); Chemerisov, Sergey D. [Argonne National Lab. (ANL), Argonne, IL (United States); Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States); Kalensky, Michael [Argonne National Lab. (ANL), Argonne, IL (United States); Heltemes, Thad A. [Argonne National Lab. (ANL), Argonne, IL (United States); Rotsch, David A [Argonne National Lab. (ANL), Argonne, IL (United States); Krebs, John F. [Argonne National Lab. (ANL), Argonne, IL (United States); Makarashvili, Vakhtang [Argonne National Lab. (ANL), Argonne, IL (United States); Stepinski, Dominique C. [Argonne National Lab. (ANL), Argonne, IL (United States); Alford, Kurt [Argonne National Lab. (ANL), Argonne, IL (United States); Bailey, James [Argonne National Lab. (ANL), Argonne, IL (United States); Byrnes, James [Argonne National Lab. (ANL), Argonne, IL (United States); Gromov, Roman [Argonne National Lab. (ANL), Argonne, IL (United States); Hafenrichter, Lohman [Argonne National Lab. (ANL), Argonne, IL (United States); Hebden, Andrew [Argonne National Lab. (ANL), Argonne, IL (United States); Jerden, James [Argonne National Lab. (ANL), Argonne, IL (United States); Jonah, Charles [Argonne National Lab. (ANL), Argonne, IL (United States); Micklich, Brad [Argonne National Lab. (ANL), Argonne, IL (United States); Quigley, Kevin [Argonne National Lab. (ANL), Argonne, IL (United States); Schneider, John [Argonne National Lab. (ANL), Argonne, IL (United States); Wesolowski, Kenneth [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States); Sun, Zaijing [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-10-01

    Argonne National Laboratory is assisting SHINE Medical Technologies in their efforts to develop the technology to become a domestic Mo-99 producer using low-enriched uranium (LEU). Mini-SHINE experiments are being performed with the high-current electron linear accelerator (linac) at Argonne. The target solution is a 90-150 g-U/L LEU uranyl sulfate at pH 1. In Phase 1, the convertor was tantalum with a maximum beam power on the convertor of 10 kW, and the target solution was limited to 5 L. This configuration generated a peak fission power density of 0.05 W/mL. Nine experiments were performed between February and October 2015. Results are reported and discussed for each experiment regarding the off-gas analysis system, the sampling and Mo-recovery operation, and the Mo-product concentration and purification system. In Phase 2, the convertor will be depleted uranium; beam power will increase to 20 kW; and the solution volume will be 18 L. This configuration will generate a fission power density of up to 1 W/mL.

  15. Future utilization of space: Silverton Conference on material science and phase transformations in zero-gravity, summary of proceeding

    Science.gov (United States)

    Eisner, M. (Editor)

    1975-01-01

    The importance of zero gravity environment in the development and production of new and improved materials is considered along with the gravitational effects on phase changes or critical behavior in a variety of materials. Specific experiments discussed include: fine scale phase separation in zero gravity; glass formation in zero gravity; effects of gravitational perturbations on determination of critical exponents; and light scattering from long wave fluctuations in liquids in zero gravity. It is concluded that the space shuttle/spacelab system is applicable to various fields of interest.

  16. Selection of Phase Space Reconstruction Parameters for EMG Signals of the Uterus

    Directory of Open Access Journals (Sweden)

    Brzozowska Ewelina

    2016-12-01

    Full Text Available Biological time series have a finite number of samples with noise included in them. Because of this fact, it is not possible to reconstruct phase space in an ideal manner. One kind of biomedical signals are electrohisterographical (EHG datasets, which represent uterine muscle contractile activity. In the process of phase space reconstruction, the most important thing is suitable choice of the method for calculating the time delay τ and embedding dimension d, which will reliably reconstruct the original signal. The parameters used in digital signal processing are key to arranging adequate parameters of the analysed attractor embedded in the phase space. The aim of this paper is to present a method employed for phase space reconstruction for EHG signals that will make it possible for their further analysis to be carried out.

  17. Culturing immobilized plant cells for the TUBUL space experiments on the DELTA and 12S Missions

    Science.gov (United States)

    Sieberer, Björn J.; Emons, Anne Mie C.; Vos, Jan W.

    2007-09-01

    For the TUBUL experiments during the DELTA mission in April 2004 and 12S mission in March/April 2006 on board the Soyuz capsule and the International Space Station we developed a method to culture and chemically fix plant suspension culture cells. The aim of the ten day experiment was to investigate the effect of microgravity on single plant cells. Fully automated experiment cassettes (Plunger Box Units) were developed by Centre for Concepts in Mechatronics (Nuenen, the Netherlands). Tobacco BY- 2 cells were immobilized in a semi- solid agarose matrix that was reinforced by a nylon mesh. This assembly allowed liquid medium refreshment, oxygen supply and chemical fixation, including a post- fixative wash. The method was optimized for post- flight analysis of cell structure, shape and size, cell division, and the microtubule cytoskeleton. The viability of cells in the agarose matrix was similar to cells grown in liquid medium under laboratory conditions, only the stationary growth phase was reached six days later.

  18. Phase Space of Rolling Solutions of the Tippe Top

    Directory of Open Access Journals (Sweden)

    S. Torkel Glad

    2007-03-01

    Full Text Available Equations of motion of an axially symmetric sphere rolling and sliding on a plane are usually taken as model of the tippe top. We study these equations in the nonsliding regime both in the vector notation and in the Euler angle variables when they admit three integrals of motion that are linear and quadratic in momenta. In the Euler angle variables (θ,φ,ψ these integrals give separation equations that have the same structure as the equations of the Lagrange top. It makes it possible to describe the whole space of solutions by representing them in the space of parameters (D,λ,E being constant values of the integrals of motion.

  19. Phase-space dynamics of runaway electrons in magnetic fields

    Science.gov (United States)

    Guo, Zehua; McDevitt, Christopher J.; Tang, Xian-Zhu

    2017-04-01

    Dynamics of runaway electrons in magnetic fields are governed by the competition of three dominant physics: parallel electric field acceleration, Coulomb collision, and synchrotron radiation. Examination of the energy and pitch-angle flows reveals that the presence of local vortex structure and global circulation is crucial to the saturation of primary runaway electrons. Models for the vortex structure, which has an O-point to X-point connection, and the bump of runaway electron distribution in energy space have been developed and compared against the simulation data. Identification of these velocity-space structures opens a new venue to re-examine the conventional understanding of runaway electron dynamics in magnetic fields.

  20. ACOSS FIVE (Active Control of Space Structures). Phase 1A

    Science.gov (United States)

    1982-03-01

    Again, in this case the specimen had been perturbed by a four-second chirp and then allowed to settle. Once a filter design has been established , the...The control design MKUCTUKAL MOOC L PtRFOHMANCl MÜDtL DISTURBANCE MODEL I ’ II Q|S£) XM=) STATE SPACE MODEL KEDUCED MODELS (HAC... establishing robustness with respect to two "point- design " perturbations. Based on the above results, and in the context of the analysis defined by the

  1. A simulation of weak-light phase-locking for space laser interferometer

    Science.gov (United States)

    Li, Y. Q.; Dong, Y. H.; Liu, H. S.; Luo, Z. R.; Jin, G.

    2017-05-01

    A simulation was investigated to better understand the impacts and effects of the additional technical noises on weak-light phase-locking for space laser interferometer. The result showed that the locking precision was limited by the phase readout noise when the laser frequency noise and clock jitter noise were removed, and this result was then confirmed by a benchtop experimental test. The required space laser interferometer noise floor was recovered from the simulation which proved the validity of the simulation program.

  2. Phase-space Analysis in the Group and Cluster Environment: Introduction and Application

    Science.gov (United States)

    Rhee, Jinsu

    2018-01-01

    Using the latest cosmological hydrodynamic N-body simulations of groups and clusters, we study how location in phase-space coordinates at z = 0 can provide information on environmental effects acting in clusters. We confirm the results of previous authors showing that galaxies tend to follow a typical path in phase-space as they settle into the cluster potential. As such, different regions of phase-space can be associated with different times since first infalling into the cluster. However, in addition, we see a clear trend between total mass loss due to cluster tides and time since infall. Thus, we find location in phase-space provides information on both infall time and tidal mass loss. We find the predictive power of phase-space diagrams remains even when projected quantities are used (i.e., line of sight velocities, and projected distances from the cluster). We provide figures that can be directly compared with observed samples of cluster galaxies and we also provide the data used to make them as supplementary data to encourage the use of phase-space diagrams as a tool to understand cluster environmental effects. We find that our results depend very weakly on galaxy mass or host mass, so the predictions in our phase-space diagrams can be applied to groups or clusters alike, or to galaxy populations from dwarfs up to giants. Finally, we give some guiding examples how our phase-space diagrams can be used in real observation, inferring time evolution of galaxy properties under cluster environment.

  3. ONKALO POSE experiment. Phase 3: execution and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Valli, J. [Poeyry Finland Oy, Vantaa (Finland); Hakala, M. [KMS-Hakala Oy, Nokia (Finland); Wanne, T. [Saanio and Riekkola Oy, Helsinki (Finland); Kantia, P. [Geofcon Oy, Rovaniemi (Finland); Siren, T.

    2014-01-15

    In-depth knowledge of the in situ stress state at the Olkiluoto site is critical for stability assessment both prior to and after deposition of spent nuclear fuel in order to understand and avoid potential damage to the rock at the site. Posiva's Olkiluoto Spalling Experiment (POSE) was designed specifically for this purpose with three primary goals: establish the in situ spalling/damage strength of Olkiluoto migmatitic gneiss, establish the state of in situ stress at the -345 m depth level and act as a Prediction-Outcome (P-O) exercise. Phases 1 and 2 of POSE are outlined in WR 2012-60. The objectives of the third phase of the POSE experiment are the same as the original objectives outlined above. This report outlines the execution and results of the third phase of the POSE experiment. The third phase of the experiment involved internally heating the third experimental hole (ONK-EH3) of the POSE niche in order to cause a symmetrical thermal stress increase around the hole due to the thermal expansion of rock. This thermomechanically induced stress increase, coupled with the estimated existing in situ stress state, should cause the maximum principal stress around the hole to exceed the predicted spalling strength of the rock around the hole. ONK-EH3 is located almost completely in pegmatitic granite. Four fractures near the top of the hole were mapped after boring ONK-EH3, and a tensile failure located at the contact between mica-rich gneiss and pegmatitic granite was observed 18 months after boring, prior to the experiment. Based on predictive calculations and the estimated in situ state of stress, the maximum principal stress magnitude should reach ca. 100 MPa when the temperature was just below 100 deg C after 12 weeks of heating. There were problems with the heater control unit at the beginning of the experiment, after which heating proceeded according to plan. The crack damage threshold of pegmatitic granite has been determined to be 85 ±17 MPa at

  4. The PICASSO Dark Matter Experiment - Getting Ready for Phase II

    Science.gov (United States)

    Krauss, Carsten B.; Picasso Collaboration

    2011-12-01

    PICASSO is a dark matter search experiment that uses the superheated droplet technique to find spin-dependently interacting WIMPs. A set of 1 l detectors with a total active mass of 19.4 g was used to prove the validity of the technique. The data from this run disfavors WIMP-proton cross sections larger than 1.3 pb for a WIMP mass of 29 GeV. Currently phase II of PICASSO is getting started. It will consist of 32 4.5 l detectors with a projected active mass of 2.5 kg and improved detectors.

  5. The PICASSO Dark Matter Experiment - Getting Ready for Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, Carsten B., E-mail: ckrauss@owl.phy.queensu.ca [Queen' s University, Department of Physics, Kingston, ON, K7L 2N6 (Canada)

    2011-12-15

    PICASSO is a dark matter search experiment that uses the superheated droplet technique to find spin-dependently interacting WIMPs. A set of 1 l detectors with a total active mass of 19.4 g was used to prove the validity of the technique. The data from this run disfavors WIMP-proton cross sections larger than 1.3 pb for a WIMP mass of 29 GeV. Currently phase II of PICASSO is getting started. It will consist of 32 4.5 l detectors with a projected active mass of 2.5 kg and improved detectors.

  6. Lichens survive in space: results from the 2005 LICHENS experiment.

    Science.gov (United States)

    Sancho, Leopoldo G; de la Torre, Rosa; Horneck, Gerda; Ascaso, Carmen; de Los Rios, Asunción; Pintado, Ana; Wierzchos, J; Schuster, M

    2007-06-01

    This experiment was aimed at establishing, for the first time, the survival capability of lichens exposed to space conditions. In particular, the damaging effect of various wavelengths of extraterrestrial solar UV radiation was studied. The lichens used were the bipolar species Rhizocarpon geographicum and Xanthoria elegans, which were collected above 2000 m in the mountains of central Spain and as endolithic communities inhabiting granites in the Antarctic Dry Valleys. Lichens were exposed to space in the BIOPAN-5 facility of the European Space Agency; BIOPAN-5 is located on the outer shell of the Earth-orbiting FOTON-M2 Russian satellite. The lichen samples were launched from Baikonur by a Soyuz rocket on May 31, 2005, and were returned to Earth after 16 days in space, at which time they were tested for survival. Chlorophyll fluorescence was used for the measurement of photosynthetic parameters. Scanning electron microscopy in back-scattered mode, low temperature scanning electron microscopy, and transmission electron microscopy were used to study the organization and composition of both symbionts. Confocal laser scanning microscopy, in combination with the use of specific fluorescent probes, allowed for the assessment of the physiological state of the cells. All exposed lichens, regardless of the optical filters used, showed nearly the same photosynthetic activity after the flight as measured before the flight. Likewise, the multimicroscopy approach revealed no detectable ultrastructural changes in most of the algal and fungal cells of the lichen thalli, though a greater proportion of cells in the flight samples had compromised membranes, as revealed by the LIVE/DEAD BacLight Bacterial Viability Kit. These findings indicate that most lichenized fungal and algal cells can survive in space after full exposure to massive UV and cosmic radiation, conditions proven to be lethal to bacteria and other microorganisms. The lichen upper cortex seems to provide adequate

  7. Lichens Survive in Space: Results from the 2005 LICHENS Experiment

    Science.gov (United States)

    Sancho, Leopoldo G.; de la Torre, Rosa; Horneck, Gerda; Ascaso, Carmen; de los Rios, Asunción; Pintado, Ana; Wierzchos, J.; Schuster, M.

    2007-06-01

    This experiment was aimed at establishing, for the first time, the survival capability of lichens exposed to space conditions. In particular, the damaging effect of various wavelengths of extraterrestrial solar UV radiation was studied. The lichens used were the bipolar species Rhizocarpon geographicum and Xanthoria elegans, which were collected above 2000 m in the mountains of central Spain and as endolithic communities inhabiting granites in the Antarctic Dry Valleys. Lichens were exposed to space in the BIOPAN-5 facility of the European Space Agency; BIOPAN-5 is located on the outer shell of the Earth-orbiting FOTON-M2 Russian satellite. The lichen samples were launched from Baikonur by a Soyuz rocket on May 31, 2005, and were returned to Earth after 16 days in space, at which time they were tested for survival. Chlorophyll fluorescence was used for the measurement of photosynthetic parameters. Scanning electron microscopy in back-scattered mode, low temperature scanning electron microscopy, and transmission electron microscopy were used to study the organization and composition of both symbionts. Confocal laser scanning microscopy, in combination with the use of specific fluorescent probes, allowed for the assessment of the physiological state of the cells. All exposed lichens, regardless of the optical filters used, showed nearly the same photosynthetic activity after the flight as measured before the flight. Likewise, the multimicroscopy approach revealed no detectable ultrastructural changes in most of the algal and fungal cells of the lichen thalli, though a greater proportion of cells in the flight samples had compromised membranes, as revealed by the LIVE/DEAD BacLight Bacterial Viability Kit. These findings indicate that most lichenized fungal and algal cells can survive in space after full exposure to massive UV and cosmic radiation, conditions proven to be lethal to bacteria and other microorganisms. The lichen upper cortex seems to provide adequate

  8. Flow Boiling and Condensation Experiment (FBCE) for the International Space Station

    Science.gov (United States)

    Mudawar, Issam; Hasan, Mohammad M.; Kharangate, Chirag; O'Neill, Lucas; Konishi, Chris; Nahra, Henry; Hall, Nancy; Balasubramaniam, R.; Mackey, Jeffrey

    2015-01-01

    The proposed research aims to develop an integrated two-phase flow boiling/condensation facility for the International Space Station (ISS) to serve as primary platform for obtaining two-phase flow and heat transfer data in microgravity.

  9. Field diversity phase retrieval method for wavefront sensing in monolithic mirror space telescopes.

    Science.gov (United States)

    Ju, Guohao; Yan, Changxiang; Yue, Dan; Gu, Zhiyuan

    2017-05-20

    To guarantee the uniqueness of the solution for the wavefront phase, a series of intensity images with known phase diversities is usually needed in the current phase retrieval wavefront sensing methods. However, to obtain these intensity images with deliberately added diversity phases, some additional instruments (e.g., beam splitters) or operations (e.g., adjustment of the focus) are usually needed, which can pose a challenge for wavefront sensing in space telescopes. This paper proposes a new concept for retrieving the wavefront phase of monolithic mirror space telescopes with perturbations, where the intensity measurements with phase diversities are directly obtained from different field positions of one image, without the need for any additional instruments or operations. To realize this new concept, we present a modified phase diversity method to account for the unknown phase diversities between these intensity measurements based on an in-depth understanding of the net aberration fields induced by misalignments and figure errors. Relevant simulations for different cases are performed to demonstrate the feasibility and accuracy of the proposed method. Since in this method the phase diversities between different intensity measurements are mainly induced by the diversities in the field position, we call it the field diversity phase retrieval method. This work can present great facility for wavefront sensing in monolithic mirror space telescopes.

  10. Viscosity Measurement via Drop Coalescence: A Space Station Experiment

    Science.gov (United States)

    Antar, Basil; Ethridge, Edwin C.

    2010-01-01

    The concept of using low gravity experimental data together with CFD simulations for measuring the viscosity of highly viscous liquids was recently validated on onboard the International Space Station (ISS). A series of microgravity tests were conducted for this purpose on the ISS in July, 2004 and in May of 2005. In these experiments two liquid drops were brought manually together until they touched and were allowed to coalesce under the action of the capillary force alone. The coalescence process was recorded photographically from which the contact radius speed of the merging drops was measured. The liquid viscosity was determined by fitting the measured data with accurate numerical simulation of the coalescence process. Several liquids were tested and for each liquid several drop diameters were employed. Experimental and numerical results will be presented in which the viscosity of several highly viscous liquids were determined using this technique.

  11. Experiments in teleoperator and autonomous control of space robotic vehicles

    Science.gov (United States)

    Alexander, Harold L.

    1991-01-01

    A program of research embracing teleoperator and automatic navigational control of freely flying satellite robots is presented. Current research goals include: (1) developing visual operator interfaces for improved vehicle teleoperation; (2) determining the effects of different visual interface system designs on operator performance; and (3) achieving autonomous vision-based vehicle navigation and control. This research program combines virtual-environment teleoperation studies and neutral-buoyancy experiments using a space-robot simulator vehicle currently under development. Visual-interface design options under investigation include monoscopic versus stereoscopic displays and cameras, helmet-mounted versus panel-mounted display monitors, head-tracking versus fixed or manually steerable remote cameras, and the provision of vehicle-fixed visual cues, or markers, in the remote scene for improved sensing of vehicle position, orientation, and motion.

  12. The Sun Radio Imaging Space Experiment (SunRISE) Mission

    Science.gov (United States)

    Lazio, Joseph; Kasper, Justin; Maksimovic, Milan; Alibay, Farah; Amiri, Nikta; Bastian, Tim; Cohen, Christina; Landi, Enrico; Manchester, Ward; Reinard, Alysha; Schwadron, Nathan; Cecconi, Baptiste; Hallinan, Gregg; Hegedus, Alex; Krupar, Vratislav; Zaslavsky, Arnaud

    2017-04-01

    Radio emission from coronal mass ejections (CMEs) is a direct tracer of particle acceleration in the inner heliosphere and potential magnetic connections from the lower solar corona to the larger heliosphere. Energized electrons excite Langmuir waves, which then convert into intense radio emission at the local plasma frequency, with the most intense acceleration thought to occur within 20 RS. The radio emission from CMEs is quite strong such that only a relatively small number of antennas is required to detect and map it, but many aspects of this particle acceleration and transport remain poorly constrained. Ground-based arrays would be quite capable of tracking the radio emission associated with CMEs, but absorption by the Earth's ionosphere limits the frequency coverage of ground-based arrays (ν ≳ 15 MHz), which in turn limits the range of solar distances over which they can track the radio emission (≲ 3RS). The state-of-the-art for tracking such emission from space is defined by single antennas (Wind/WAVES, Stereo/SWAVES), in which the tracking is accomplished by assuming a frequency-to-density mapping; there has been some success in triangulating the emission between the spacecraft, but considerable uncertainties remain. We describe the Sun Radio Imaging Space Experiment (SunRISE) mission concept: A constellation of small spacecraft in a geostationary graveyard orbit designed to localize and track radio emissions in the inner heliosphere. Each spacecraft would carry a receiving system for observations below 25 MHz, and SunRISE would produce the first images of CMEs more than a few solar radii from the Sun. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  13. The Sun Radio Interferometer Space Experiment (SunRISE)

    Science.gov (United States)

    Alibay, F.; Lazio, J.; Kasper, J. C.; Amiri, N.; Bastian, T.; Cohen, C.; Landi, E.; Manchester, W.; Reinard, A.; Schwadron, N.; Hegedus, A. M.; Maksimovic, M.; Zaslavsky, A.; Cecconi, B.; Hallinan, G.; Krupar, V.

    2016-12-01

    Radio emission from coronal mass ejections (CMEs) is a direct tracer of the particle acceleration in the inner heliosphere and potential magnetic connections from the lower solar corona to the larger heliosphere. However, many aspects of this particle acceleration remain poorly constrained. The radio emission from CMEs is quite strong such that only a relatively small number of antennas is required to map it. However, the state-of-the-art for tracking such emission is only defined by single antennas (Wind/WAVES, Stereo/SWAVES) in which the tracking is accomplished by assuming a frequency-to-density mapping. These are limited to tracking CMEs to only a few solar radii before the frequencies of radio emission drop below the Earth's ionospheric cutoff. Triangulation between the STEREO/SWAVES and Wind/WAVES instruments have provided some initial constraints on particle acceleration sites at larger distances (lower frequencies), but the uncertainties remain considerable. We present the Sun Radio Imaging Space Experiment (SunRISE) mission concept: a space-based array designed to localize such radio emissions. This low-cost constellation is composed of small spacecraft placed in a geostationary graveyard orbit, each carrying an HF radio receiver. In this concept, each spacecraft would perform concurrent observations below 25 MHz, which would then be correlated on the ground to produce the first images of CMEs more than a few solar radii from the Sun. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  14. New calorimeters for space experiments: physics requirements and technological challenges

    Science.gov (United States)

    Marrocchesi, Pier Simone

    2015-07-01

    Direct measurements of charged cosmic radiation with instruments in Low Earth Orbit (LEO), or flying on balloons above the atmosphere, require the identification of the incident particle, the measurement of its energy and possibly the determination of its sign-of-charge. The latter information can be provided by a magnetic spectrometer together with a measurement of momentum. However, magnetic deflection in space experiments is at present limited to values of the Maximum Detectable Rigidity (MDR) hardly exceeding a few TV. Advanced calorimetric techniques are, at present, the only way to measure charged and neutral radiation at higher energies in the multi-TeV range. Despite their mass limitation, calorimeters may achieve a large geometric factor and provide an adequate proton background rejection factor, taking advantage of a fine granularity and imaging capabilities. In this lecture, after a brief introduction on electromagnetic and hadronic calorimetry, an innovative approach to the design of a space-borne, large acceptance, homogeneous calorimeter for the detection of high energy cosmic rays will be described.

  15. Preliminary results from the heavy ions in space experiment

    Science.gov (United States)

    Adams, James H., Jr.; Beahm, Lorraine P.; Tylka, Allan J.

    1992-01-01

    The Heavy Ions In Space (HIIS) experiment has two primary objectives: (1) to measure the elemental composition of ultraheavy galactic cosmic rays, beginning in the tin-barium region of the periodic table; and (2) to study heavy ions which arrive at LDEF below the geomagnetic cutoff, either because they are not fully stripped of electrons or because their source is within the magnetosphere. Both of these objectives have practical as well as astrophysical consequences. In particular, the high atomic number of the ultraheavy galactic cosmic rays puts them among the most intensely ionizing particles in Nature. They are therefore capable of upsetting electronic components normally considered immune to such effects. The below cutoff heavy ions are intensely ionizing because of their low velocity. They can be a significant source of microelectronic anomalies in low inclination orbits, where Earth's magnetic field protects satellites from most particles from interplanetary space. The HIIS results will lead to significantly improved estimates of the intensely ionizing radiation environment.

  16. Analysis of Scalar Field Cosmology with Phase Space Deformations

    Directory of Open Access Journals (Sweden)

    Sinuhe Perez-Payan

    2014-01-01

    modifying the symplectic structure of the minisuperspace variables. The effects of the deformation are studied in the “C-frame” and the “NC-frame.” In order to remove the ambiguities of working on different frames, a new principle is introduced. When we impose that both frames should be physically equivalent, we conclude that the only possibility for this model, is to have an effective cosmological constant Λeff≥0. Finally we bound the parameter space for θ and β.

  17. Space qualified Nd:YAG laser (phase 1 - design)

    Science.gov (United States)

    Foster, J. D.; Kirk, R. F.

    1971-01-01

    Results of a design study and preliminary design of a space qualified Nd:YAG laser are presented. A theoretical model of the laser was developed to allow the evaluation of the effects of various parameters on its performance. Various pump lamps were evaluated and sum pumping was considered. Cooling requirements were examined and cooling methods such as radiation, cryogenic and conductive were analysed. Power outputs and efficiences of various configurations and the pump and laser lifetime are discussed. Also considered were modulation and modulating methods.

  18. Recovery of In-Space Cubesat Experiments (RICE) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ELORET Corporation, in collaboration with the Space Systems Design Laboratory of Georgia Institute of Technology, proposes developing and demonstrating a...

  19. Historical parallels of biological space experiments from Soyuz, Salyut and Mir to Shenzhou flights

    Science.gov (United States)

    Nechitailo, Galina S.; Kondyurin, Alexey

    2016-07-01

    Human exploitation of space is a great achievement of our civilization. After the first space flights a development of artificial biological environment in space systems is a second big step. First successful biological experiments on a board of space station were performed on Salyut and Mir stations in 70-90th of last century such as - first long time cultivation of plants in space (wheat, linen, lettuce, crepis); - first flowers in space (Arabidopsis); - first harvesting of seeds in space (Arabidopsis); - first harvesting of roots (radish); - first full life cycle from seeds to seeds in space (wheat), Guinness recorded; - first tissue culture experiments (Panax ginseng L, Crocus sativus L, Stevia rebaundiana B; - first tree growing in space for 2 years (Limonia acidissima), Guinness recorded. As a new wave, the modern experiments on a board of Shenzhou Chinese space ships are performed with plants and tissue culture. The space flight experiments are now focused on applications of the space biology results to Earth technologies. In particular, the tomato seeds exposed 6 years in space are used in pharmacy industry in more then 10 pharmaceutical products. Tissue culture experiments are performed on the board of Shenzhou spaceship for creation of new bioproducts including Space Panax ginseng, Space Spirulina, Space Stetatin, Space Tomato and others products with unique properties. Space investments come back.

  20. On evolution of small spheres in the phase space of a dynamical system*

    Directory of Open Access Journals (Sweden)

    Komech Sergei

    2012-08-01

    Full Text Available We study the connection between the entropy of a dynamical system and the boundary distortion rate of regions in the phase space of the system. Nous étudions la connexion entre l’entropie d’un système dynamique et le taux de distortion au bord dans l’espace des phases du système.

  1. FCJ-133 The Scripted Spaces of Urban Ubiquitous Computing: The experience, poetics, and politics of public scripted space

    Directory of Open Access Journals (Sweden)

    Christian Ulrik Andersen

    2011-12-01

    Full Text Available This article proposes and introduces the concept of ‘scripted space’ as a new perspective on ubiquitous computing in urban environments. Drawing on urban history, computer games, and a workshop study of the city of Lund the article discusses the experience of digitally scripted spaces, and their relation to the history of public spaces. In conclusion, the article discusses the potential for employing scripted spaces as a reinvigoration of urban public space.

  2. Phase 1 space fission propulsion system testing and development progress

    Science.gov (United States)

    van Dyke, Melissa; Houts, Mike; Pedersen, Kevin; Godfroy, Tom; Dickens, Ricky; Poston, David; Reid, Bob; Salvail, Pat; Ring, Peter

    2001-02-01

    Successful development of space fission systems will require an extensive program of affordable and realistic testing. In addition to tests related to design/development of the fission system, realistic testing of the actual flight unit must also be performed. Testing can be divided into two categories, non-nuclear tests and nuclear tests. Full power nuclear tests of space fission systems are expensive, time consuming, and of limited use, even in the best of programmatic environments. If the system is designed to operate within established radiation damage and fuel burn up limits while simultaneously being designed to allow close simulation of heat from fission using resistance heaters, high confidence in fission system performance and lifetime can be attained through a series of non-nuclear tests. Non-nuclear tests are affordable and timely, and the cause of component and system failures can be quickly and accurately identified, MSFC is leading a Safe Affordable Fission Engine (SAFE) test series whose ultimate goal is the demonstration of a 300 kW flight configuration system using non-nuclear testing. This test series is carried out in collaboration with other NASA centers, other government agencies, industry, and universities. If SAFE-related nuclear tests are desired, they will have a high probability of success and can be performed at existing nuclear facilities. The paper describes the SAFE non-nuclear test series, which includes test article descriptions, test results and conclusions, and future test plans. .

  3. Proliferation of stability in phase and parameter spaces of nonlinear systems

    Science.gov (United States)

    Manchein, Cesar; da Silva, Rafael M.; Beims, Marcus W.

    2017-08-01

    In this work, we show how the composition of maps allows us to multiply, enlarge, and move stable domains in phase and parameter spaces of discrete nonlinear systems. Using Hénon maps with distinct parameters, we generate many identical copies of isoperiodic stable structures (ISSs) in the parameter space and attractors in phase space. The equivalence of the identical ISSs is checked by the largest Lyapunov exponent analysis, and the multiplied basins of attraction become riddled. Our proliferation procedure should be applicable to any two-dimensional nonlinear system.

  4. Aerosol Sampling Experiment on the International Space Station

    Science.gov (United States)

    Meyer, Marit E.

    2017-01-01

    The International Space Station (ISS) is a unique indoor environment which serves as both home and workplace to the astronaut crew. There is currently no particulate monitoring, although particulate matter requirements exist. An experiment to collect particles in the ISS cabin was conducted recently. Two different aerosol samplers were used for redundancy and to collect particles in two size ranges spanning from 10 nm to hundreds of micrometers. The Active Sampler is a battery operated thermophoretic sampler with an internal pump which draws in air and collects particles directly on a transmission electron microscope grid. This commercial-off-the-shelf device was modified for operation in low gravity. The Passive Sampler has five sampling surfaces which were exposed to air for different durations in order to collect at least one sample with an optimal quantity of particles for microscopy. These samples were returned to Earth for analysis with a variety of techniques to obtain long-term average concentrations and identify particle emission sources. Results are compared with the inventory of ISS aerosols which was created based on sparse data and the literature. The goal of the experiment is to obtain data on indoor aerosols on ISS for future particulate monitor design and development.

  5. Electron holes in phase space: What they are and why they matter

    Science.gov (United States)

    Hutchinson, I. H.

    2017-05-01

    This is a tutorial and selective review explaining the fundamental concepts and some currently open questions concerning the plasma phenomenon of the electron hole. The widespread occurrence of electron holes in numerical simulations, space-craft observations, and laboratory experiments is illustrated. The elementary underlying theory is developed of a one-dimensional electron hole as a localized potential maximum, self-consistently sustained by a deficit of trapped electron phase-space density. The spatial extent of a hole is typically a few Debye lengths; what determines the minimum and maximum possible lengths is explained, addressing the key aspects of the as yet unsettled dispute between the integral and differential approaches to hole structure. In multiple dimensions, holes tend to form less readily; they generally require a magnetic field and distribution-function anisotropy. The mechanisms by which they break up are explained, noting that this transverse instability is not fully understood. Examples are given of plasma circumstances where holes play an important role, and of recent progress on understanding their holistic kinematics and self-acceleration.

  6. New Space Vector Selection Scheme for VSI Supplied Dual Three-Phase Induction Machine

    Directory of Open Access Journals (Sweden)

    MILICEVIC, D.

    2013-02-01

    Full Text Available This paper presents a novel space vector selection scheme applicable for the control of dual three-phase induction motor drives supplied from a six-phase voltage source inverter (VSI. The vector selection method is based on the vector space decomposition technique (VSD. Unique vector selection pattern simplifies problems related to complicated implementation of standard VSD in commercially available digital signals processors (DSP. The proposed vector selection scheme is verified through a theoretical analysis, computer simulations and practical experimental results conducted on a dual three-phase test rig prototype with control algorithm implemented in Texas Instrument?s TMS320F2808 DSP.

  7. Concurrent growth of two phases in 2D space

    Directory of Open Access Journals (Sweden)

    A.A. Burbelko

    2008-12-01

    Full Text Available The kinetics of phase transformations has been studied within the framework of the Kolmogorov-Johnson-Mehl-Avrami (KJMA theory. This theory accurately describes only the parallel growth of anisotropic products with identical convex shape. The identical growth velocity distribution at an interface is the indispensable condition for the above restriction. The proposed earlier extension of KJMA theory (statistical theory of the screened growth enlarges the scope of its application and eliminates the above limitation. The results of the application of this extension were compared with the results obtained during modelling of the concurrent growth of the two types of circular particles on a plane, where the said particles were characterised by different growth rates and modelling was carried out by the method of cellular automata (CA.

  8. Weak equivalence principle in noncommutative phase space and the parameters of noncommutativity

    Science.gov (United States)

    Gnatenko, Kh. P.; Tkachuk, V. M.

    2017-08-01

    The weak equivalence principle is studied in a space with noncommutativity of coordinates and noncommutativity of momenta. We find conditions on the parameters of noncommutativity which give the possibility to recover the equivalence principle in two-dimensional noncommutative phase space. It is also shown that in the case when these conditions are satisfied the motion of the center-of-mass of a composite system in noncommutative phase space and the relative motion are independent, the kinetic energy of composite system has additivity property and is independent on the systems composition. So, we propose conditions on the parameters of noncommutativity which give the possibility to solve the list of problems in noncommutative phase space.

  9. Virtual Reality Simulation of the International Space Welding Experiment

    Science.gov (United States)

    Phillips, James A.

    1996-01-01

    Virtual Reality (VR) is a set of breakthrough technologies that allow a human being to enter and fully experience a 3-dimensional, computer simulated environment. A true virtual reality experience meets three criteria: (1) It involves 3-dimensional computer graphics; (2) It includes real-time feedback and response to user actions; and (3) It must provide a sense of immersion. Good examples of a virtual reality simulator are the flight simulators used by all branches of the military to train pilots for combat in high performance jet fighters. The fidelity of such simulators is extremely high -- but so is the price tag, typically millions of dollars. Virtual reality teaching and training methods are manifestly effective, and we have therefore implemented a VR trainer for the International Space Welding Experiment. My role in the development of the ISWE trainer consisted of the following: (1) created texture-mapped models of the ISWE's rotating sample drum, technology block, tool stowage assembly, sliding foot restraint, and control panel; (2) developed C code for control panel button selection and rotation of the sample drum; (3) In collaboration with Tim Clark (Antares Virtual Reality Systems), developed a serial interface box for the PC and the SGI Indigo so that external control devices, similar to ones actually used on the ISWE, could be used to control virtual objects in the ISWE simulation; (4) In collaboration with Peter Wang (SFFP) and Mark Blasingame (Boeing), established the interference characteristics of the VIM 1000 head-mounted-display and tested software filters to correct the problem; (5) In collaboration with Peter Wang and Mark Blasingame, established software and procedures for interfacing the VPL DataGlove and the Polhemus 6DOF position sensors to the SGI Indigo serial ports. The majority of the ISWE modeling effort was conducted on a PC-based VR Workstation, described below.

  10. High-efficiency resonant rf spin rotator with broad phase space acceptance for pulsed polarized cold neutron beams

    Directory of Open Access Journals (Sweden)

    P.-N. Seo

    2008-08-01

    Full Text Available High precision fundamental neutron physics experiments have been proposed for the intense pulsed spallation neutron beams at JSNS, LANSCE, and SNS to test the standard model and search for new physics. Certain systematic effects in some of these experiments have to be controlled at the few ppb level. The NPDGamma experiment, a search for the small parity-violating γ-ray asymmetry A_{γ} in polarized cold neutron capture on parahydrogen, is one example. For the NPDGamma experiment we developed a radio-frequency resonant spin rotator to reverse the neutron polarization in a 9.5  cm×9.5  cm pulsed cold neutron beam with high efficiency over a broad cold neutron energy range. The effect of the spin reversal by the rotator on the neutron beam phase space is compared qualitatively to rf neutron spin flippers based on adiabatic fast passage. We discuss the design of the spin rotator and describe two types of transmission-based neutron spin-flip efficiency measurements where the neutron beam was both polarized and analyzed by optically polarized ^{3}He neutron spin filters. The efficiency of the spin rotator was measured at LANSCE to be 98.8±0.5% for neutron energies from 3 to 20 meV over the full phase space of the beam. Systematic effects that the rf spin rotator introduces to the NPDGamma experiment are considered.

  11. High-efficiency Resonant rf Spin Rotator with Broad Phase Space Acceptance for Pulsed Polarized Cold Neutron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Seo, P. -N. [Los Alamos National Laboratory (LANL); Barron-Palos, L. [Arizona State University; Bowman, J. D. [Los Alamos National Laboratory (LANL); Chupp, T. E. [University of Michigan; Crawford, C. [University of Tennessee, Knoxville (UTK); Dabaghyan, M. [University of New Hampshire; Dawkins, M. [Indiana University; Freedman, S. J. [University of California; Gentile, T. R. [National Institute of Standards and Technology (NIST); Gericke, M. T. [University of Manitoba, Canada; Gillis, R. C. [University of Manitoba, Canada; Greene, G. L. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Hersman, F. W. [University of New Hampshire; Jones, G. L. [Hamilton College, New York; Kandes, M. [University of Michigan; Lamoreaux, S. [Los Alamos National Laboratory (LANL); Lauss, B. [University of California, Berkeley; Leuschner, M. B. [Indiana University; Mahurin, R. [University of Tennessee, Knoxville (UTK); Mason, M. [University of New Hampshire; Mei, J. [Indiana University; Mitchell, G. S. [Los Alamos National Laboratory (LANL); Nann, H. [Indiana University; Page, S. A. [University of Manitoba, Canada; Penttila, S. I. [Los Alamos National Laboratory (LANL); Ramsay, W. D. [University of Manitoba & TRIUMF, Canada; Salas Bacci, A. [Los Alamos National Laboratory (LANL); Santra, S. [Indiana University; Sharma, M. [University of Michigan; Smith, T. B. [University of Dayton, Ohio; Snow, W. [Indiana University; Wilburn, W. S. [Los Alamos National Laboratory (LANL); Zhu, H. [University of New Hampshire

    2008-01-01

    High precision fundamental neutron physics experiments have been proposed for the intense pulsed spallation neutron beams at JSNS, LANSCE, and SNS to test the standard model and search for new physics. Certain systematic effects in some of these experiments have to be controlled at the few ppb level. The NPD Gamma experiment, a search for the small parity-violating {gamma}-ray asymmetry A{sub Y} in polarized cold neutron capture on parahydrogen, is one example. For the NPD Gamma experiment we developed a radio-frequency resonant spin rotator to reverse the neutron polarization in a 9.5 cm x 9.5 cm pulsed cold neutron beam with high efficiency over a broad cold neutron energy range. The effect of the spin reversal by the rotator on the neutron beam phase space is compared qualitatively to rf neutron spin flippers based on adiabatic fast passage. We discuss the design of the spin rotator and describe two types of transmission-based neutron spin-flip efficiency measurements where the neutron beam was both polarized and analyzed by optically polarized {sup 3}He neutron spin filters. The efficiency of the spin rotator was measured at LANSCE to be 98.8 {+-} 0.5% for neutron energies from 3 to 20 meV over the full phase space of the beam. Systematic effects that the rf spin rotator introduces to the NPD Gamma experiment are considered.

  12. SPAce Readiness Coherent Lidar Experiment: validation of observing system simulations

    Science.gov (United States)

    Emmitt, George D.; Miller, Timothy; Kavaya, Michael J.

    1998-12-01

    NASA recently approved a mission to fly a Doppler Wind Lidar on a US Space Shuttle. SPARCLE, managed by Marshall Space Flight Center in Huntsville, AL, is targeted for launch in March 2001. This mission is viewed as a necessary demonstration of a solid state lidar using coherent detection before committing resources to a 3-5 year research or operational mission. While, to many, this shuttle mission is seen as the first step in a series leading to a fully operational wind observing system, to others, it is a chance to validate predictions of performance based upon theoretical models, analyses of airborne and ground-based data and sophisticated observing system simulation experiments. The SPARCLE instrument is a 100 mJ, 6 Hz, diode pumped 2 micron laser with a .25 m telescope using heterodyne mixing in a fiber and an InGaAs detector. A 25 cm silicon wedge scanner will be used in step-stare modes with dwells ranging from 60 seconds to .5 seconds. Pointing knowledge is achieved with a dedicated GPS/INS mounted close to the lidar. NASA's hitchhiker program is providing the instrument enclosures and mission logistics support. An on- board data system in sized to record 80 Gbytes of raw signal from two 400 MHz A/D converters. On-board signal processing will be used to control the frequency of the Master Oscillator. SPARCLE is predicted to have a singleshot backscatter sensitivity near 5 by 10-6 m-1 sr-1. To achieve higher sensitivity, shot accumulation will be employed. Ground-based, 2 micron DWLs have been used to assess the benefits of shot accumulation. Airborne programs like MACAWS have provided good data st for evaluating various sampling strategies and signal processing algorithms. Using these real data to calibrate out simulation models, we can describe when and how well SPARCLE is expected to perform.

  13. The Space Science Lab: High School Student Solar Research Experience

    Science.gov (United States)

    Castelaz, Michael W.; Whitworth, C.; Harris, B.; David, C.

    2007-12-01

    Native American, Hispanic, African American, and other underrepresented high school students in rural Western North Carolina have the unprecedented opportunity as researchers in the Space Science Lab to conduct visible and radio observations of the Sun. The program involves 90 students over a three year period. The primary goal is to reach students who otherwise would not have this opportunity, and motivate them to develop the critical thinking skills necessary for objective scientific inquiry. Students develop skills in electronics, computer sciences, astronomy, physics and earth sciences. Equally important is the hope that the students will become interested in pursuing careers in research or other science-related areas. We expect their enthusiasm for science will increase by experiencing research investigations that are fun and relevant to their understanding of the world around them. The students conduct their own research, and also interact with scientists around the world. A total of 54 students have spent a week at the Space Science Lab located on the campus of the Pisgah Astronomical Research Institute (PARI) during the Summers of 2006 and 2007. Students construct their own JOVE radio telescopes that they bring home to continue their observations during the academic year. They share their results during four follow-up sessions throughout the school year. The students also have Internet access to radio telescopes and solar monitoring equipment at PARI. We report on results from student evaluations from the first year in 2006 and current session student experiences. We gratefully acknowledge support from the Burroughs Wellcome Fund - Student Science Enrichment Program

  14. Application of radio phase modes to modification and remote sensing of the atmosphere and space

    Science.gov (United States)

    Isham, B.; Mohammadi, S.; Chau, J.; Hysell, D. L.; Daldorff, L. K.; Thide, B.; Bergman, J.

    2009-12-01

    Radio phase modes are a low-frequency electromagnetic wave (radio) manifestation of photon orbital angular momentum (OAM) modes. At optical (laser) wavelengths OAM is an active area of theoretical and experimental research. Theory and modelling of radio phase modes show they may also easily be generated and, under certain conditions, detected with modern radio antenna arrays. Transimission of radio phase modes has been attempted using the HAARP HF transmitter in Alaska and the Jicamarca VHF radar in Peru. The HAARP experiment was designed to search for ionospheric modification effects of phase modes, while the Jicamarca experiment explored the possibility of using phase modes for remote sensing. Further work at Jicamarca will be aimed at verifying phase mode transmission and detection capabilities by using the moon as a reflector. Other potential applications of phase modes include the detection of radio OAM generated by astrophysical sources and their use in communications as a way of transmitting multiple signals at a single frequency.

  15. Experiments on phase transitions in three-dimensional dusty plasma under microgravity conditions

    Science.gov (United States)

    Molotkov, V. I.; Naumkin, V. N.; Lipaev, A. M.; Zhukhovitskii, D. I.; Usachev, A. D.; Fortov, V. E.; Thomas, H. M.

    2017-11-01

    Complex (dusty) plasmas are composed of weakly ionized gas and charged microparticles and represent the plasma state of soft matter. Due to the “heavy” component, microparticles, and the low density of the surrounding medium, the rarefied gas and plasma, it is necessary to perform experiments under microgravity conditions to cover a broad range of experimental parameters which are not available on ground. The investigations have been performed onboard the International Space Station (ISS) with the help of the PK-3 Plus laboratory. This laboratory was mainly built to investigate the crystalline state of complex plasma, the so-called plasma crystal, its phase transitions and processes in multi-particle mixtures. The crystal–liquid phase transition was obtained in large three-dimensional isotropic dusty plasma system. Observations of a transition of the dusty plasma system state due to the particle charge reduction and due to variations of the plasma component density are presented.

  16. The LTP Experiment on LISA Pathfinder: Operational Definition of TT Gauge in Space

    CERN Document Server

    Armano, Michele

    2011-01-01

    The European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA) are planning the Laser Interferometer Space Antenna (LISA) mission in order to detect GW. The need of accurate testing of free-fall and knowledge of noise in a space environment similar to LISA's is considered mandatory a pre-phase for the project. Therefore the LISA Pathfinder mission has been designed by ESA to fly the LISA Technology Package (LTP), aiming at testing free-fall by measuring the residual acceleration between two test-bodies in the dynamical scheme we address as "drag-free". The spectral map of the residual acceleration as function of frequency will convey information on the local noise level, thus producing a picture of the environmental working conditions for LISA itself. The thesis contains abundant material on the problem of compensating static gravity, the development of a theory of orthogonalization of reference and cross-talk for the LTP experiment. The construction of the laser detection proced...

  17. Dynamical phase separation using a microfluidic device: experiments and modeling

    Science.gov (United States)

    Aymard, Benjamin; Vaes, Urbain; Radhakrishnan, Anand; Pradas, Marc; Gavriilidis, Asterios; Kalliadasis, Serafim; Complex Multiscale Systems Team

    2017-11-01

    We study the dynamical phase separation of a binary fluid by a microfluidic device both from the experimental and from the modeling points of view. The experimental device consists of a main channel (600 μm wide) leading into an array of 276 trapezoidal capillaries of 5 μm width arranged on both sides and separating the lateral channels from the main channel. Due to geometrical effects as well as wetting properties of the substrate, and under well chosen pressure boundary conditions, a multiphase flow introduced into the main channel gets separated at the capillaries. Understanding this dynamics via modeling and numerical simulation is a crucial step in designing future efficient micro-separators. We propose a diffuse-interface model, based on the classical Cahn-Hilliard-Navier-Stokes system, with a new nonlinear mobility and new wetting boundary conditions. We also propose a novel numerical method using a finite-element approach, together with an adaptive mesh refinement strategy. The complex geometry is captured using the same computer-aided design files as the ones adopted in the fabrication of the actual device. Numerical simulations reveal a very good qualitative agreement between model and experiments, demonstrating also a clear separation of phases.

  18. Tracking Gas Phase Composition in Oil evaporation and Oxidation Experiments

    Science.gov (United States)

    Amador-Muñoz, O.; Zhang, H.; Misztal, P. K.; Worton, D.; Drozd, G.; Goldstein, A. H.

    2015-12-01

    Primary Organic Aerosol (POA) is emitted directly by anthropogenic or natural sources, whereas Secondary Organic Aerosol (SOA) is formed in the atmosphere through chemical reactions that result from conversion of more volatile species into lower volatility oxidized products and their subsequent condensation to the particulate phase. We studied SOA formation from evaporation of Macondo crude oil (MC 252) using a wind tunnel coupled to a flow tube oxidation reactor. Ozone, UV lights, and water vapor were used to make OH radicals. Organic compounds in the gas phase, both those evaporated from the wind tunnel and those formed in the flow tube oxidation experiments, were monitored using proton-transfer-reaction mass spectrometry (PTR-qMS and PTR-TOF-MS). We observed approximately 400 different species. Compounds with less than C10 were mostly evaporated in the first 5 hours when maximum SOA formation was also obtained. Hydrocarbons with carbon number (11-14) were still present in the oil after 12 h of continuous evaporation at wind speed of 2 m s-1. We will show the implications of these results for the production of SOA related to the range of evaporated chemical size and reactivity.

  19. GEM Detectors for the DarkLight Phase-1 Experiment

    Science.gov (United States)

    Mohammed Prem Nazeer, Sahara Jesmin; DarkLight Collaboration

    2017-09-01

    The DarkLight experiment has been proposed to search for a heavy photon A' in the mass range of 10-100 MeV/c2 produced in electron-proton collisions. Phase-I of DarkLight has started to take place in 2016 at the Low Energy Recirculator Facility (LERF) at Jefferson Lab. LERF delivered a 100 MeV electron beam onto a windowless hydrogen gas target. The phase-I detector tracks leptons inside the DarkLight solenoid with a set of Gas Electron Multiplier (GEM) detectors, combined with segmented scintillators for triggering. The GEM telescope consists of four 10 × 10 cm2 triple layer GEM chambers with 2D readout strips, mounted in a slightly angled fixed frame about 12 cm tall. The GEM data are read out with analog pipeline front-end cards (APV-25) each of which can process 128 readout channels. Each GEM chamber has 250 channels for each coordinate axis, read out with two APVs on each side, resulting in 2000 readout channels for the GEM stack, processed by 16 APVs. One Multi Purpose Digitizer (MPD) module is used to read out all of the 16 APV-25 cards. Details of the design and the readout of the GEM detectors will be presented, as well as discussion of their performance in the August run. This work has been supported by NSF PHY-1436680 and PHY-1505934.

  20. Phase and Pupil Amplitude Recovery for JWST Space-Optics Control

    Science.gov (United States)

    Dean, B. H.; Zielinski, T. P.; Smith, J. S.; Bolcar, M. R.; Aronstein, D. L.; Fienup, J. R.

    2010-01-01

    This slide presentation reviews the phase and pupil amplitude recovery for the James Webb Space Telescope (JWST) Near Infrared Camera (NIRCam). It includes views of the Integrated Science Instrument Module (ISIM), the NIRCam, examples of Phase Retrieval Data, Ghost Irradiance, Pupil Amplitude Estimation, Amplitude Retrieval, Initial Plate Scale Estimation using the Modulation Transfer Function (MTF), Pupil Amplitude Estimation vs lambda, Pupil Amplitude Estimation vs. number of Images, Pupil Amplitude Estimation vs Rotation (clocking), and Typical Phase Retrieval Results Also included is information about the phase retrieval approach, Non-Linear Optimization (NLO) Optimized Diversity Functions, and Least Square Error vs. Starting Pupil Amplitude.

  1. Phase Space Exploration of Acetylene at Energies up to 13,000 Cm-1

    Science.gov (United States)

    Perry, David S.; Martens, Jonathan; Herman, Michel; Amyay, Badr

    2011-06-01

    The rotation-vibration Hamiltonian of acetylene is known in detail up to 13,000 Cm-1 in the electronic ground state, allows the calculation of time-dependent dynamics for postulated excitations of certain bright states. Three different measures of phase space exploration are examined including the participation number, Gruebele's dispersion, and the Shannon entropy. The time scales for phase space exploration span the range from 20 fs to 10 ps. The volume of phase space explored by the dynamics increases with energy and the rotational quantum number, J reaching about 90% of the (GOE) statistical limit at 12,000 Cm-1 and J = 100. At low and intermediate J, the extent of phase space exploration is reduced for the local bender and counter-rotator bright states as compared to their normal mode counterparts. However, the phase space exploration of the local mode CH stretch state is similar to that of the corresponding normal mode vibration. These calculations shed light on the applicability of the energy randomization assumption that is at the heart of the Rice-Rampsberger-Kassel-Marcus (RRKM) theory of unimolecular reactions.

  2. Extremal rotating black holes in the near-horizon limit: Phase space and symmetry algebra

    Directory of Open Access Journals (Sweden)

    G. Compère

    2015-10-01

    Full Text Available We construct the NHEG phase space, the classical phase space of Near-Horizon Extremal Geometries with fixed angular momenta and entropy, and with the largest symmetry algebra. We focus on vacuum solutions to d dimensional Einstein gravity. Each element in the phase space is a geometry with SL(2,R×U(1d−3 isometries which has vanishing SL(2,R and constant U(1 charges. We construct an on-shell vanishing symplectic structure, which leads to an infinite set of symplectic symmetries. In four spacetime dimensions, the phase space is unique and the symmetry algebra consists of the familiar Virasoro algebra, while in d>4 dimensions the symmetry algebra, the NHEG algebra, contains infinitely many Virasoro subalgebras. The nontrivial central term of the algebra is proportional to the black hole entropy. The conserved charges are given by the Fourier decomposition of a Liouville-type stress-tensor which depends upon a single periodic function of d−3 angular variables associated with the U(1 isometries. This phase space and in particular its symmetries can serve as a basis for a semiclassical description of extremal rotating black hole microstates.

  3. High-pressure phases of CaCO 3: Crystal structure prediction and experiment

    Science.gov (United States)

    Oganov, Artem R.; Glass, Colin W.; Ono, Shigeaki

    2006-01-01

    Post-aragonite phase of CaCO3, experimentally known to be stable above 40 GPa [S. Ono, T. Kikegawa, Y. Ohishi, J. Tsuchiya, Post-aragonite phase transformation in CaCO3 at 40 GPa, Am. Mineral. 90 (2005) 667-671], is believed to be a major carbon-containing mineral in the Earth's mantle. Crystal structure of this mineral phase could not be solved using experimental data or traditional theoretical simulation methods and remained a controversial issue. Using a combination of advanced ab initio simulation techniques and high-pressure experiment, we have been able to determine the crystal structure of CaCO3 post-aragonite. Here, we performed simulations with the USPEX code [C.W. Glass, A.R. Oganov, and N. Hansen, (in preparation). USPEX: a universal structure prediction program], which is based on an evolutionary algorithm using ab initio free energy as the fitness function. This novel methodology for crystal structure prediction, which uses only the chemical composition as input, is described in detail. For CaCO3, we identify a number of energetically competitive structures, the most stable of which closely matches the experimental powder diffraction pattern and, in agreement with experiment, becomes more stable than aragonite above 42 GPa. This structure belongs to a new structure type, which is also adopted by the high-pressure post-aragonite phases of SrCO3 and BaCO3. It has 2 formula units in the orthorhombic unit cell (space group Pmmn) and contains triangular CO32- ions and Ca2+ ions in the 12-fold coordination. Above 137 GPa, a pyroxene-type structure (space group C2221) with chains of CO44- tetrahedra becomes more stable than post-aragonite. For MgCO3, this structure becomes more stable than magnesite above 106 GPa and is a good candidate structure for MgCO3 post-magnesite.

  4. Embodiment and the experience of built space: the contributions of ...

    African Journals Online (AJOL)

    This paper explores the problem of how we perceive built space and the ways that we relate to its abstract representations. Poincaré presented the problem that space poses for the 20th century in his essay 'The Relativity of Space', in which the human body and technics are already a part of our spatial perceptions.

  5. Droplet Combustion Experiments Aboard the International Space Station

    Science.gov (United States)

    Dietrich, Daniel L.; Nayagam, Vedha; Hicks, Michael C.; Ferkul, Paul V.; Dryer, Frederick L.; Farouk, Tanvir; Shaw, Benjamin D.; Suh, Hyun Kyu; Choi, Mun Y.; Liu, Yu Cheng; Avedisian, C. Thomas; Williams, Forman A.

    2014-10-01

    This paper summarizes the first results from isolated droplet combustion experiments performed on the International Space Station (ISS). The long durations of microgravity provided in the ISS enable the measurement of droplet and flame histories over an unprecedented range of conditions. The first experiments were with heptane and methanol as fuels, initial droplet droplet diameters between 1.5 and 5.0 m m, ambient oxygen mole fractions between 0.1 and 0.4, ambient pressures between 0.7 and 3.0 a t m and ambient environments containing oxygen and nitrogen diluted with both carbon dioxide and helium. The experiments show both radiative and diffusive extinction. For both fuels, the flames exhibited pre-extinction flame oscillations during radiative extinction with a frequency of approximately 1 H z. The results revealed that as the ambient oxygen mole fraction was reduced, the diffusive-extinction droplet diameter increased and the radiative-extinction droplet diameter decreased. In between these two limiting extinction conditions, quasi-steady combustion was observed. Another important measurement that is related to spacecraft fire safety is the limiting oxygen index (LOI), the oxygen concentration below which quasi-steady combustion cannot be supported. This is also the ambient oxygen mole fraction for which the radiative and diffusive extinction diameters become equal. For oxygen/nitrogen mixtures, the LOI is 0.12 and 0.15 for methanol and heptane, respectively. The LOI increases to approximately 0.14 (0.14 O 2/0.56 N 2/0.30 C O 2) and 0.17 (0.17 O 2/0.63 N 2/0.20 C O 2) for methanol and heptane, respectively, for ambient environments that simulated dispersing an inert-gas suppressant (carbon dioxide) into a nominally air (1.0 a t m) ambient environment. The LOI is approximately 0.14 and 0.15 for methanol and heptane, respectively, when helium is dispersed into air at 1 atm. The experiments also showed unique burning behavior for large heptane droplets. After the

  6. A 4-channel 3 Tesla phased array receive coil for awake rhesus monkey fMRI and diffusion MRI experiments.

    Science.gov (United States)

    Khachaturian, Mark Haig

    2010-01-01

    Awake monkey fMRI and diffusion MRI combined with conventional neuroscience techniques has the potential to study the structural and functional neural network. The majority of monkey fMRI and diffusion MRI experiments are performed with single coils which suffer from severe EPI distortions which limit resolution. By constructing phased array coils for monkey MRI studies, gains in SNR and anatomical accuracy (i.e., reduction of EPI distortions) can be achieved using parallel imaging. The major challenges associated with constructing phased array coils for monkeys are the variation in head size and space constraints. Here, we apply phased array technology to a 4-channel phased array coil capable of improving the resolution and image quality of full brain awake monkey fMRI and diffusion MRI experiments. The phased array coil is that can adapt to different rhesus monkey head sizes (ages 4-8) and fits in the limited space provided by monkey stereotactic equipment and provides SNR gains in primary visual cortex and anatomical accuracy in conjunction with parallel imaging and improves resolution in fMRI experiments by a factor of 2 (1.25 mm to 1.0 mm isotropic) and diffusion MRI experiments by a factor of 4 (1.5 mm to 0.9 mm isotropic).

  7. Results of the Fluid Merging Viscosity Measurement International Space Station Experiment

    Science.gov (United States)

    Ethridge, Edwin C.; Kaukler, William; Antar, Basil

    2009-01-01

    The purpose of FMVM is to measure the rate of coalescence of two highly viscous liquid drops and correlate the results with the liquid viscosity and surface tension. The experiment takes advantage of the low gravitational free floating conditions in space to permit the unconstrained coalescence of two nearly spherical drops. The merging of the drops is accomplished by deploying them from a syringe and suspending them on Nomex threads followed by the astronaut s manipulation of one of the drops toward a stationary droplet till contact is achieved. Coalescence and merging occurs due to shape relaxation and reduction of surface energy, being resisted by the viscous drag within the liquid. Experiments were conducted onboard the International Space Station in July of 2004 and subsequently in May of 2005. The coalescence was recorded on video and down-linked near real-time. When the coefficient of surface tension for the liquid is known, the increase in contact radius can be used to determine the coefficient of viscosity for that liquid. The viscosity is determined by fitting the experimental speed to theoretically calculated contact radius speed for the same experimental parameters. Recent fluid dynamical numerical simulations of the coalescence process will be presented. The results are important for a better understanding of the coalescence process. The experiment is also relevant to liquid phase sintering, free form in-situ fabrication, and as a potential new method for measuring the viscosity of viscous glass formers at low shear rates.

  8. Space experiment "Cellular Responses to Radiation in Space (CELLRAD)": Hardware and biological system tests

    Science.gov (United States)

    Hellweg, Christine E.; Dilruba, Shahana; Adrian, Astrid; Feles, Sebastian; Schmitz, Claudia; Berger, Thomas; Przybyla, Bartos; Briganti, Luca; Franz, Markus; Segerer, Jürgen; Spitta, Luis F.; Henschenmacher, Bernd; Konda, Bikash; Diegeler, Sebastian; Baumstark-Khan, Christa; Panitz, Corinna; Reitz, Günther

    2015-11-01

    One factor contributing to the high uncertainty in radiation risk assessment for long-term space missions is the insufficient knowledge about possible interactions of radiation with other spaceflight environmental factors. Such factors, e.g. microgravity, have to be considered as possibly additive or even synergistic factors in cancerogenesis. Regarding the effects of microgravity on signal transduction, it cannot be excluded that microgravity alters the cellular response to cosmic radiation, which comprises a complex network of signaling pathways. The purpose of the experiment ;Cellular Responses to Radiation in Space; (CELLRAD, formerly CERASP) is to study the effects of combined exposure to microgravity, radiation and general space flight conditions on mammalian cells, in particular Human Embryonic Kidney (HEK) cells that are stably transfected with different plasmids allowing monitoring of proliferation and the Nuclear Factor κB (NF-κB) pathway by means of fluorescent proteins. The cells will be seeded on ground in multiwell plate units (MPUs), transported to the ISS, and irradiated by an artificial radiation source after an adaptation period at 0 × g and 1 × g. After different incubation periods, the cells will be fixed by pumping a formaldehyde solution into the MPUs. Ground control samples will be treated in the same way. For implementation of CELLRAD in the Biolab on the International Space Station (ISS), tests of the hardware and the biological systems were performed. The sequence of different steps in MPU fabrication (cutting, drilling, cleaning, growth surface coating, and sterilization) was optimized in order to reach full biocompatibility. Different coatings of the foil used as growth surface revealed that coating with 0.1 mg/ml poly-D-lysine supports cell attachment better than collagen type I. The tests of prototype hardware (Science Model) proved its full functionality for automated medium change, irradiation and fixation of cells. Exposure of

  9. Electron beam phase-space measurement using a high-precision tomography technique

    Directory of Open Access Journals (Sweden)

    V. Yakimenko

    2003-12-01

    Full Text Available We report a measurement of the multidimensional phase-space density distribution of an electron bunch. The measurement combines the techniques of picosecond slice-emittance measurement and high-resolution tomographic measurement of transverse phase space. This technique should have a significant impact on the development of low emittance beams and their many applications, such as short-wavelength free-electron lasers and laser accelerators. A diagnostic that provides detailed information on the density distribution of the electron bunch in multidimensional phase space is an essential tool for obtaining a small emittance at a reasonable charge and for understanding the physics of emittance growth. We previously reported a measurement of the slice emittance of a picosecond electron beam [J. S. Fraser, R. L. Sheffield, and E. R. Gray, Nucl. Instrum. Methods Phys. Res., Sect. A 250, 71 (1986.]. The tomographic reconstruction of the phase space was suggested [X. Qiu, K. Batchelor, I. Ben-Zvi, and X. J. Wang, Phys. Rev. Lett. 76, 3723 (1996.] and implemented [C. B. McKee, P. G. O’Shea, and J. M. J. Madey, Nucl. Instrum. Methods Phys. Res., Sect. A 358, 264 (1995; I. Ben-Zvi, J. X. Qiu, and X. J. Wang, in Proceedings of the Particle Accelerator Conference, Vancouver, 1997 (IEEE, Piscataway, NJ, 1997.] using a single quadrupole scan. In the present work we expand the tomographic reconstruction work and combine it with the slice-emittance method. Our present tomographic work pays special attention to the accuracy of the phase-space reconstruction. We use a transport line with nine focusing magnets, and present an analysis and technique aimed at the control of the optical functions and phases. This high-precision phase-space tomography together with the ability to modify the radial charge distribution of the electron beam presents an opportunity to improve the emittance and apply nonlinear radial emittance corrections. Combining the

  10. Amateur Radio on the International Space Station - Phase 2 Hardware System

    Science.gov (United States)

    Bauer, F.; McFadin, L.; Bruninga, B.; Watarikawa, H.

    2003-01-01

    The International Space Station (ISS) ham radio system has been on-orbit for over 3 years. Since its first use in November 2000, the first seven expedition crews and three Soyuz taxi crews have utilized the amateur radio station in the Functional Cargo Block (also referred to as the FGB or Zarya module) to talk to thousands of students in schools, to their families on Earth, and to amateur radio operators around the world. Early on, the Amateur Radio on the International Space Station (ARISS) international team devised a multi-phased hardware development approach for the ISS ham radio station. Three internal development Phases. Initial Phase 1, Mobile Radio Phase 2 and Permanently Mounted Phase 3 plus an externally mounted system, were proposed and agreed to by the ARISS team. The Phase 1 system hardware development which was started in 1996 has since been delivered to ISS. It is currently operational on 2 meters. The 70 cm system is expected to be installed and operated later this year. Since 2001, the ARISS international team have worked to bring the second generation ham system, called Phase 2, to flight qualification status. At this time, major portions of the Phase 2 hardware system have been delivered to ISS and will soon be installed and checked out. This paper intends to provide an overview of the Phase 1 system for background and then describe the capabilities of the Phase 2 radio system. It will also describe the current plans to finalize the Phase 1 and Phase 2 testing in Russia and outlines the plans to bring the Phase 2 hardware system to full operation.

  11. Experiments on Quantum Hall Topological Phases in Ultra Low Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Du, Rui-Rui [Rice Univ., Houston, TX (United States). Dept. of Physics and Astronomy

    2015-02-14

    This project is to cool electrons in semiconductors to extremely low temperatures and to study new states of matter formed by low-dimensional electrons (or holes). At such low temperatures (and with an intense magnetic field), electronic behavior differs completely from ordinary ones observed at room temperatures or regular low temperature. Studies of electrons at such low temperatures would open the door for fundamental discoveries in condensed matter physics. Present studies have been focused on topological phases in the fractional quantum Hall effect in GaAs/AlGaAs semiconductor heterostructures, and the newly discovered (by this group) quantum spin Hall effect in InAs/GaSb materials. This project consists of the following components: 1) Development of efficient sample cooling techniques and electron thermometry: Our goal is to reach 1 mK electron temperature and reasonable determination of electron temperature; 2) Experiments at ultra-low temperatures: Our goal is to understand the energy scale of competing quantum phases, by measuring the temperature-dependence of transport features. Focus will be placed on such issues as the energy gap of the 5/2 state, and those of 12/5 (and possible 13/5); resistive signature of instability near 1/2 at ultra-low temperatures; 3) Measurement of the 5/2 gaps in the limit of small or large Zeeman energies: Our goal is to gain physics insight of 5/2 state at limiting experimental parameters, especially those properties concerning the spin polarization; 4) Experiments on tuning the electron-electron interaction in a screened quantum Hall system: Our goal is to gain understanding of the formation of paired fractional quantum Hall state as the interaction pseudo-potential is being modified by a nearby screening electron layer; 5) Experiments on the quantized helical edge states under a strong magnetic field and ultralow temperatures: our goal is to investigate both the bulk and edge states in a quantum spin Hall insulator under

  12. Tomographic reconstruction of transverse phase space from turn-by-turn profile data

    CERN Document Server

    Hancock, S; Lindroos, M

    1999-01-01

    Tomographic methods have the potential for useful application in beam diagnostics. The tomographic reconstruction of transverse phase space density from turn-by-turn profile data has been studied with particular attention to the effects of dispersion and chromaticity. It is shown that the modified Algebraic Reconstruction Technique (ART) that deals successfully with the problem of non-linear motion in the longitudinal plane cannot, in general, be extended to cover the transverse case. Instead, an approach is proposed in which the effect of dispersion is deconvoluted from the measured profiles before the phase space picture is reconstructed using either the modified ART algorithm or the inverse Radon Transform. This requires an accurate knowledge of the momentum distribution of the beam and the modified ART reconstruction of longitudinal phase space density yields just such information. The method has been tested extensively with simulated data.

  13. Nonlinear Prediction As A Tool For Determining Parameters For Phase Space Reconstruction In Meteorology

    Science.gov (United States)

    Miksovsky, J.; Raidl, A.

    Time delays phase space reconstruction represents one of useful tools of nonlinear time series analysis, enabling number of applications. Its utilization requires the value of time delay to be known, as well as the value of embedding dimension. There are sev- eral methods how to estimate both these parameters. Typically, time delay is computed first, followed by embedding dimension. Our presented approach is slightly different - we reconstructed phase space for various combinations of mentioned parameters and used it for prediction by means of the nearest neighbours in the phase space. Then some measure of prediction's success was computed (correlation or RMSE, e.g.). The position of its global maximum (minimum) should indicate the suitable combination of time delay and embedding dimension. Several meteorological (particularly clima- tological) time series were used for the computations. We have also created a MS- Windows based program in order to implement this approach - its basic features will be presented as well.

  14. 3D imaging in volumetric scattering media using phase-space measurements.

    Science.gov (United States)

    Liu, Hsiou-Yuan; Jonas, Eric; Tian, Lei; Zhong, Jingshan; Recht, Benjamin; Waller, Laura

    2015-06-01

    We demonstrate the use of phase-space imaging for 3D localization of multiple point sources inside scattering material. The effect of scattering is to spread angular (spatial frequency) information, which can be measured by phase space imaging. We derive a multi-slice forward model for homogenous volumetric scattering, then develop a reconstruction algorithm that exploits sparsity in order to further constrain the problem. By using 4D measurements for 3D reconstruction, the dimensionality mismatch provides significant robustness to multiple scattering, with either static or dynamic diffusers. Experimentally, our high-resolution 4D phase-space data is collected by a spectrogram setup, with results successfully recovering the 3D positions of multiple LEDs embedded in turbid scattering media.

  15. Phase-space networks of the six-vertex model under different boundary conditions.

    Science.gov (United States)

    Han, Yilong

    2010-04-01

    The six-vertex model is mapped to three-dimensional sphere stacks and different boundary conditions corresponding to different containers. The shape of the container provides a qualitative visualization of the boundary effect. Based on the sphere-stacking picture, we map the phase spaces of the six-vertex models to discrete networks. A node in the network represents a state of the system, and an edge between two nodes represents a zero-energy spin flip, which corresponds to adding or removing a sphere. The network analysis shows that the phase spaces of systems with different boundary conditions share some common features. We derived a few formulas for the number and the sizes of the disconnected phase-space subnetworks under the periodic boundary conditions. The sphere stacking provides new challenges in combinatorics and may cast light on some two-dimensional models.

  16. Formation and interaction of multiple coherent phase space structures in plasma

    Science.gov (United States)

    Kakad, Amar; Kakad, Bharati; Omura, Yoshiharu

    2017-06-01

    The head-on collision of multiple counter-propagating coherent phase space structures associated with the ion acoustic solitary waves (IASWs) in plasmas composed of hot electrons and cold ions is studied here by using one-dimensional Particle-in-Cell simulation. The chains of counter-propagating IASWs are generated in the plasma by injecting the Gaussian perturbations in the equilibrium electron and ion densities. The head-on collisions of the counter-propagating electron and ion phase space structures associated with IASWs are allowed by considering the periodic boundary condition in the simulation. Our simulation shows that the phase space structures are less significantly affected by their collision with each other. They emerge out from each other by retaining their characteristics, so that they follow soliton type behavior. We also find that the electrons trapped within these IASW potentials are accelerated, while the ions are decelerated during the course of their collisions.

  17. Scientific data processing for the MICROSCOPE space experiment

    Science.gov (United States)

    Hardy, Emilie; Metris, Gilles; Santos Rodrigues, Manuel; Touboul, Pierre; Chhun, Ratana; Baghi, Quentin; Berge, Joel

    The MICROSCOPE space mission aims at testing the Equivalence Principle, which states that the acceleration of a test object due to gravitation is independent of its mass and internal composition. The Equivalence Principle is at the basis of General Relativity and has been tested on-ground with a record accuracy of a few 10(-13) . However, most theories for the unification of the gravitation with the three other fundamental interactions predict that it will be violated at a level 10(-18) -10(-13) . This range cannot be reached on Earth because of the numerous perturbations in the terrestrial environment. Being performed in space, the MICROSCOPE experiment will be able to overcome these limitations in order to test the Equivalence Principle with an accuracy of 10(-15) . The instrument will be embarked on board a drag-free microsatellite orbiting the Earth, and consists in a differential electrostatic accelerometer composed of two cylindrical test masses made of different materials. The position of the masses is detected thanks to capacitive sensors, while control loops with electrostatic actuation keep them concentric, so that they both are submitted to the same gravitational field. The electrostatic acceleration applied to the masses to maintain them relatively motionless are measured and will demonstrate a violation of the Equivalence Principle if found unequal. The potential Equivalence Principle violation signal is expected at a well identified frequency, f _{EP}. However, the raw measurement is impacted by systematic instrumental errors, which are calibrated in-orbit during dedicated sessions. The data processing therefore includes the correction of the measurement in order to reduce the contribution of these errors at f _{EP}. Other perturbations must be considered during the data analysis: numerical effects arise from the finite time span of the measurement. A procedure have thus been determined in order to extract the Equivalence Principle violation parameter

  18. Phase space analysis for a scalar-tensor model with kinetic and Gauss-Bonnet couplings

    CERN Document Server

    Granda, L N

    2016-01-01

    We study the phase space for an scalar-tensor string inspired model of dark energy with non minimal kinetic and Gauss Bonnet couplings. The form of the scalar potential and of the coupling terms is of the exponential type, which give rise to appealing cosmological solutions. The critical points describe a variety of cosmological scenarios that go from matter or radiation dominated universe to dark energy dominated universe. There were found trajectories in the phase space departing from unstable or saddle fixed points and arriving to the stable scalar field dominated point corresponding to late-time accelerated expansion.

  19. The application of the phase space time evolution method to electron shielding

    Science.gov (United States)

    Cordaro, M. C.; Zucker, M. S.

    1972-01-01

    A computer technique for treating the motion of charged and neutral particles and called the phase space time evolution method was developed. This technique employs the computer's bookkeeping capacity to keep track of the time development of a phase space distribution of particles. This method was applied to a study of the penetration of electrons. A 1 MeV beam of electrons normally incident on a semi-infinite slab of aluminum was used. Results of the calculation were compared with Monte Carlo calculations and experimental results. Time-dependent PSTE electron penetration results for the same problem are presented.

  20. Design of diffractive optical elements for the fractional Fourier transform domain: phase-space approach.

    Science.gov (United States)

    Testorf, Markus

    2006-01-01

    Phase-space optics is used to relate the problem of designing diffractive optical elements for any first-order optical system to the corresponding design problem in the Fraunhofer diffraction regime. This, in particular, provides a novel approach for the fractional Fourier transform domain. For fractional Fourier transforms of arbitrary order, the diffractive element is determined as the optimum design computed for a generic Fourier transform system, scaled and modulated with a parabolic lens function. The phase-space description also identifies critical system parameters that limit the performance and applicability of this method. Numerical simulations of paraxial wave propagation are used to validate the method.

  1. Hamiltonian reductions of the one-dimensional Vlasov equation using phase-space moments

    Science.gov (United States)

    Chandre, C.; Perin, M.

    2016-03-01

    We consider Hamiltonian closures of the Vlasov equation using the phase-space moments of the distribution function. We provide some conditions on the closures imposed by the Jacobi identity. We completely solve some families of examples. As a result, we show that imposing that the resulting reduced system preserves the Hamiltonian character of the parent model shapes its phase space by creating a set of Casimir invariants as a direct consequence of the Jacobi identity. We exhibit three main families of Hamiltonian models with two, three, and four degrees of freedom aiming at modeling the complexity of the bunch of particles in the Vlasov dynamics.

  2. Phase space interrogation of the empirical response modes for seismically excited structures

    Science.gov (United States)

    Paul, Bibhas; George, Riya C.; Mishra, Sudib K.

    2017-07-01

    Conventional Phase Space Interrogation (PSI) for structural damage assessment relies on exciting the structure with low dimensional chaotic waveform, thereby, significantly limiting their applicability to large structures. The PSI technique is presently extended for structure subjected to seismic excitations. The high dimensionality of the phase space for seismic response(s) are overcome by the Empirical Mode Decomposition (EMD), decomposing the responses to a number of intrinsic low dimensional oscillatory modes, referred as Intrinsic Mode Functions (IMFs). Along with their low dimensionality, a few IMFs, retain sufficient information of the system dynamics to reflect the damage induced changes. The mutually conflicting nature of low-dimensionality and the sufficiency of dynamic information are taken care by the optimal choice of the IMF(s), which is shown to be the third/fourth IMFs. The optimal IMF(s) are employed for the reconstruction of the Phase space attractor following Taken's embedding theorem. The widely referred Changes in Phase Space Topology (CPST) feature is then employed on these Phase portrait(s) to derive the damage sensitive feature, referred as the CPST of the IMFs (CPST-IMF). The legitimacy of the CPST-IMF is established as a damage sensitive feature by assessing its variation with a number of damage scenarios benchmarked in the IASC-ASCE building. The damage localization capability, remarkable tolerance to noise contamination and the robustness under different seismic excitations of the feature are demonstrated.

  3. Phased array ultrasonic examination of space shuttle main engine nozzle weld

    Science.gov (United States)

    James, S.; Engel, J.; Kimbrough, D.; Suits, M.

    2002-05-01

    This paper describes a Phased Array Ultrasonic Examination that was developed for the examination of a limited access circumferential Inconel 718 fusion weld of a Space Shuttle Main Engine Nozzle-Cone. The paper discusses the selection and formation criteria used for the phased array focal laws, the reference standard that simulated hardware conditions, the examination concept, and results. Several unique constraints present during this examination included limited probe movement to a single axis and one-sided access to the weld.

  4. High spatial resolution hard X-ray microscope using X-ray refractive lens and phase contrast imaging experiments

    CERN Document Server

    Kohmura, Y; Takeuchi, A; Takano, H; Suzuki, Y; Ishikawa, T; Ohigashi, T; Yokosuka, H

    2001-01-01

    A high spatial resolution X-ray microscope was constructed using an X-ray refractive lens as an objective. The spatial resolution was tested using 18 keV X-ray. A 0.4 mu m line and 0.4 mu m space tantalum test pattern was successfully resolved. Using the similar setup with the addition of a phase plate, a Zernike type phase-contrast microscopy experiment was carried out for the phase retrieval of the samples. Two-dimensional phase-contrast images were successfully taken for the first time in the hard X-ray region. Images of a gold mesh sample were analyzed and the validity of this method was indicated. An improvement of the lens, however, is required for the precise phase retrieval of the samples.

  5. Traffic model for commercial payloads in the Materials Experiment Assembly (MEA). [market research in commercial space processing

    Science.gov (United States)

    Tietzel, F. A.

    1979-01-01

    One hundred individuals representing universities, technical institutes, government agencies, and industrial facilities were surveyed to determine potential commercial use of a self-contained, automated assembly for the space processing of materials during frequent shuttle flights for the 1981 to 1987 period. The approach used and the results of the study are summarized. A time time-phased projection (traffic model) of commercial usage of the materials experiment assembly is provided.

  6. The YES2 Experience : Towards Sustainable Space Transportation using Tethers

    NARCIS (Netherlands)

    Van der Heide, E.J.; Kruijff, M.; Ockels, W.J.

    2008-01-01

    Today there is no common vision on sustainable space transportation. Rockets expel gasses and solid rockets often small particles. These have negative effect on the environment, but it is not understood to what extent. With ever growing demand for access to space, sustainable technology developments

  7. Near equality of ion phase space densities at earth, Jupiter, and Saturn

    Science.gov (United States)

    Cheng, A. F.; Krimigis, S. M.; Armstrong, T. P.

    1985-01-01

    Energetic-ion phase-space density profiles are strikingly similar in the inner magnetospheres of earth, Jupiter, and Saturn for ions of first adiabatic invariant near 100 MeV/G and small mirror latitudes. Losses occur inside L approximately equal to 7 for Jupiter and Saturn and inside L approximately equal to 5 at earth. At these L values there exist steep plasma-density gradients at all three planets, associated with the Io plasma torus at Jupiter, the Rhea-Dione-Tethys torus at Saturn, and the plasmasphere at earth. Measurements of ion flux-tube contents at Jupiter and Saturn by the low-energy charged-particle experiment show that these are similar (for O ions at L = 5-9) to those at earth (for protons at L = 2-6). Furthermore, the thermal-ion flux-tube contents from Voyager plasma-science data at Jupiter and Saturn are also very nearly equal, and again similar to those at earth, differing by less than a factor of 3 at the respective L values. The near equality of energetic and thermal ion flux-tube contents at earth, Jupiter, and Saturn suggests the possibility of strong physical analogies in the interaction between plasma and energetic particles at the plasma tori/plasma sheets of Jupiter and Saturn and the plasmasphere of earth.

  8. Microgravity Multi-Phase Flow Experiment for Suborbital Testing (MFEST) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA Johnson Space Center (JSC), Crew and Thermal Systems Division (CTSD), had previously developed an orbital flight experiment to 1) test the feasibility of a...

  9. Space-frequency analysis with parallel computing in a phase-sensitive optical time-domain reflectometer distributed sensor.

    Science.gov (United States)

    Hui, Xiaonan; Ye, Taihang; Zheng, Shilie; Zhou, Jinhai; Chi, Hao; Jin, Xiaofeng; Zhang, Xianmin

    2014-10-01

    For a phase-sensitive optical time-domain reflectometer (ϕ-OTDR) distributed sensor system, space-frequency analysis can reduce the false alarm by analyzing the frequency distribution compared with the traditional difference value method. We propose a graphics processing unit (GPU)-based parallel computing method to perform multichannel fast Fourier transform (FFT) and realize the real-time space-frequency analysis. The experiment results show that the time taken by the multichannel FFT decreased considerably based on this GPU parallel computing. The method can be completed with a sensing fiber up to 16 km long and an entry-level GPU. Meanwhile, the GPU can reduce the computing load of the central processing unit from 70% down to less than 20%. We carried out an experiment on a two-point space-frequency analysis, and the results clearly and simultaneously show the vibration point locations and frequency components. The sensor system outputs the real-time space-frequency spectra continuously with a spatial resolution of 16.3 m and frequency resolution of 2.25 Hz.

  10. Simulations of minor mergers - II. The phase-space structure of thick discs

    NARCIS (Netherlands)

    Villalobos, Alvaro; Helmi, Amina

    2009-01-01

    We analyse the phase-space structure of simulated thick discs that are the result of a 5:1 mass-ratio merger between a disc galaxy and a satellite. Our main goal is to establish what would be the imprints of a merger origin for the Galactic thick disc. We find that the spatial distribution predicted

  11. Phase-space diffusion in turbulent plasmas: The random acceleration problem revisited

    DEFF Research Database (Denmark)

    Pécseli, H.L.; Trulsen, J.

    1991-01-01

    Phase-space diffusion of test particles in turbulent plasmas is studied by an approach based on a conditional statistical analysis of fluctuating electrostatic fields. Analytical relations between relevant conditional averages and higher-order correlations, , and trip...

  12. On coherent-state representations of quantum mechanics: Wave mechanics in phase space

    DEFF Research Database (Denmark)

    Møller, Klaus Braagaard; Jørgensen, Thomas Godsk; Torres-Vega, Gabino

    1997-01-01

    In this article we argue that the state-vector phase-space representation recently proposed by Torres-Vega and co-workers [introduced in J. Chem. Phys. 98, 3103 (1993)] coincides with the totality of coherent-state representations for the Heisenberg-Weyl group. This fact leads to ambiguities when...

  13. NOTE: A technique for generating phase-space-based Monte Carlo beamlets in radiotherapy applications

    Science.gov (United States)

    Bush, K.; Popescu, I. A.; Zavgorodni, S.

    2008-09-01

    As radiotherapy treatment planning moves toward Monte Carlo (MC) based dose calculation methods, the MC beamlet is becoming an increasingly common optimization entity. At present, methods used to produce MC beamlets have utilized a particle source model (PSM) approach. In this work we outline the implementation of a phase-space-based approach to MC beamlet generation that is expected to provide greater accuracy in beamlet dose distributions. In this approach a standard BEAMnrc phase space is sorted and divided into beamlets with particles labeled using the inheritable particle history variable. This is achieved with the use of an efficient sorting algorithm, capable of sorting a phase space of any size into the required number of beamlets in only two passes. Sorting a phase space of five million particles can be achieved in less than 8 s on a single-core 2.2 GHz CPU. The beamlets can then be transported separately into a patient CT dataset, producing separate dose distributions (doselets). Methods for doselet normalization and conversion of dose to absolute units of Gy for use in intensity modulated radiation therapy (IMRT) plan optimization are also described.

  14. Numerical method for estimating the size of chaotic regions of phase space

    Energy Technology Data Exchange (ETDEWEB)

    Henyey, F.S.; Pomphrey, N.

    1987-10-01

    A numerical method for estimating irregular volumes of phase space is derived. The estimate weights the irregular area on a surface of section with the average return time to the section. We illustrate the method by application to the stadium and oval billiard systems and also apply the method to the continuous Henon-Heiles system. 15 refs., 10 figs. (LSP)

  15. Technology Integration: Exploring Interactive Whiteboards as Dialogic Spaces in the Foundation Phase Classroom

    Science.gov (United States)

    de Silva, Chamelle R.; Chigona, A.; Adendorff, S. A.

    2016-01-01

    Among its many affordances, the interactive whiteboard (IWB) as a digital space for children's dialogic engagement in the Foundation Phase classroom remains largely under-exploited. This paper emanates from a study which was undertaken in an attempt to understand how teachers acquire knowledge of emerging technologies and how this shapes their…

  16. A High-Resolution Multi-Slit Phase Space Measurement Technique for Low-Emittance Beams

    Energy Technology Data Exchange (ETDEWEB)

    Thangaraj, J. C.T. [Fermilab; Piot, P. [Northern Illinois U.

    2012-07-25

    Precise measurement of transverse phase space of a high-brightness electron beamis of fundamental importance in modern accelerators and free-electron lasers. Often, the transverse phase space of a high-brightness, space-charge-dominated electron beam is measured using a multi-slit method. In this method, a transverse mask (slit/pepperpot) samples the beaminto a set of beamlets, which are then analyzed on to a screen downstream. The resolution in this method is limited by the type of screen used which is typically around 20 mum for a high-sensitivity Yttrium Aluminum Garnet screen. Accurate measurement of sub-micron transverse emittance using this method would require a long drift space between the multi-slit mask and observation screen. In this paper, we explore a variation of the technique that incorporates quadrupole magnets between the multi-slit mask and the screen. It is shown that this arrangement can improve the resolution of the transverse-phase-space measurement with in a short footprint.

  17. Space experiment "Rad Gene"-report 1; p53-Dependent gene expression in human cultured cells exposed to space environment

    Science.gov (United States)

    Takahashi, Akihisa; Ohnishi, Takeo; Suzuki, Hiromi; Omori, Katsunori; Seki, Masaya; Hashizume, Toko; Shimazu, Toru; Ishioka, Noriaki

    The space environment contains two major biologically significant influences: space radiations and microgravity. A p53 tumor suppressor protein plays a role as a guardian of the genome through the activity of p53-centered signal transduction pathways. The aim of this study was to clarify the biological effects of space radiations, microgravity and a space environment on the gene and protein expression of p53-dependent regulated genes. Space experiments were performed with two human cultured lymphoblastoid cell lines: one cells line (TSCE5) bears a wild-type p53 gene status, and another cells line (WTK1) bears a mutated p53 gene status. Un-der one gravity or microgravity condition, the cells were grown in the cell biology experimental facility (CBEF) of the International Space Station (ISS) for 8 days without experiencing the stress during launching and landing because the cells were frozen during these periods. Ground control samples also were cultured for 8 days in the CBEF on the ground during the same periods as space flight. Gene and protein expression was analyzed by using DNA chip (a 44k whole human genome microarray, Agilent Technologies Inc.) and protein chip (PanoramaTM Ab MicroArray, Sigma-Aldrich Co.), respectively. In addition, we analyzed the gene expression in cultured cells after space flight during 133 days with frozen condition. We report the results and discussion from the viewpoint of the functions of the up-regulated and down-regulated genes after an exposure to space radiations and/or microgravity. The initial goal of this space experiment was completely achieved. It is expected that data from this type of work will be helpful in designing physical protection from the deleterious effects of space radiations during long term stays in space.

  18. Physics of Colloids in Space (PCS): Microgravity Experiment Completed Operations on the International Space Station

    Science.gov (United States)

    Doherty, Michael P.; Sankaran, Subramanian

    2003-01-01

    Immediately after mixing, the two-phase-like colloid-polymer critical point sample begins to phase separate, or de-mix, into two phases-one that resembles a gas and one that resembles a liquid, except that the particles are colloids and not atoms. The colloid-poor black regions (colloidal gas) grow bigger, and the colloid-rich white regions (colloidal liquid) become whiter as the domains further coarsen. Finally, complete phase separation is achieved, that is, just one region of each colloid-rich (white) and colloid-poor (black) phase. This process was studied over four decades of length scale, from 1 micrometer to 1 centimeter.

  19. Phase space simulation of collisionless stellar systems on the massively parallel processor

    Science.gov (United States)

    White, Richard L.

    1987-01-01

    A numerical technique for solving the collisionless Boltzmann equation describing the time evolution of a self gravitating fluid in phase space was implemented on the Massively Parallel Processor (MPP). The code performs calculations for a two dimensional phase space grid (with one space and one velocity dimension). Some results from calculations are presented. The execution speed of the code is comparable to the speed of a single processor of a Cray-XMP. Advantages and disadvantages of the MPP architecture for this type of problem are discussed. The nearest neighbor connectivity of the MPP array does not pose a significant obstacle. Future MPP-like machines should have much more local memory and easier access to staging memory and disks in order to be effective for this type of problem.

  20. Extending the possibilities in phase space analysis of synchrotron radiation x-ray optics.

    Science.gov (United States)

    Ferrero, Claudio; Smilgies, Detlef-Matthias; Riekel, Christian; Gatta, Gilles; Daly, Peter

    2008-08-01

    A simple analytical approach to phase space analysis of the performance of x-ray optical setups (beamlines) combining several elements in position-angle-wavelength space is presented. The mathematical description of a large class of optical elements commonly used on synchrotron beamlines has been reviewed and extended with respect to the existing literature and is reported in a revised form. Novel features are introduced, in particular, the possibility to account for imperfections on mirror surfaces and to incorporate nanofocusing devices like refractive lenses in advanced beamline setups using the same analytical framework. Phase space analysis results of the simulation of an undulator beamline with focusing optics at the European Synchrotron Radiation Facility compare favorably with results obtained by geometric ray-tracing methods and, more importantly, with experimental measurements. This approach has been implemented into a simple and easy-to-use program toolkit for optical calculations based on the Mathematica software package.

  1. EnviroNET: Space environment for Strategic Defense Initiative experiments

    Science.gov (United States)

    Lauriente, Michael

    1989-01-01

    EnviroNET is an operational system available to the Strategic Defense Initiative (SDI) experimenters who have access to a terminal or dial-up port. It is a tail node on Space Physics Analysis Network (SPAN) accessible directly or through the national networks via NPSS. Some of the benefits to using EnviroNET include: validated NASA environmental information and interactive space models; facilitating the payload integration process; easy access to expert assistance; and potential for time and cost savings.

  2. Your Place in Space: Classroom Experiment on Spatial Location Theory

    Science.gov (United States)

    Bergman, Margo; Mateer, G. Dirk; Reksulak, Michael; Rork, Jonathan C.; Wilson, Rick K.; Zirkle, David

    2009-01-01

    The authors detail an urban economics experiment that is easily run in the classroom. The experiment has a flexible design that allows the instructor to explore how congestion, zoning, public transportation, and taxation levels determine the bid-rent function. Heterogeneous agents in the experiment compete for land use using a simple auction…

  3. Relativity effects for space-based coherent lidar experiments

    Science.gov (United States)

    Gudimetla, V. S. Rao

    1996-01-01

    An effort was initiated last year in the Astrionics Laboratory at Marshall Space Flight Center to examine and incorporate, if necessary, the effects of relativity in the design of space-based lidar systems. A space-based lidar system, named AEOLUS, is under development at Marshall Space Flight Center and it will be used to accurately measure atmospheric wind profiles. Effects of relativity were also observed in the performance of space-based systems, for example in case of global positioning systems, and corrections were incorporated into the design of instruments. During the last summer, the effects of special relativity on the design of space-based lidar systems were studied in detail, by analyzing the problem of laser scattering off a fixed target when the source and a co-located receiver are moving on a spacecraft. Since the proposed lidar system uses a coherent detection system, errors even in the order of a few microradians must be corrected to achieve a good signal-to-noise ratio. Previous analysis assumed that the ground is flat and the spacecraft is moving parallel to the ground, and developed analytical expressions for the location, direction and Doppler shift of the returning radiation. Because of the assumptions used in that analysis, only special relativity effects were involved. In this report, that analysis is extended to include general relativity and calculate its effects on the design.

  4. Unconventional Topological Phase Transition in Two-Dimensional Systems with Space-Time Inversion Symmetry.

    Science.gov (United States)

    Ahn, Junyeong; Yang, Bohm-Jung

    2017-04-14

    We study a topological phase transition between a normal insulator and a quantum spin Hall insulator in two-dimensional (2D) systems with time-reversal and twofold rotation symmetries. Contrary to the case of ordinary time-reversal invariant systems, where a direct transition between two insulators is generally predicted, we find that the topological phase transition in systems with an additional twofold rotation symmetry is mediated by an emergent stable 2D Weyl semimetal phase between two insulators. Here the central role is played by the so-called space-time inversion symmetry, the combination of time-reversal and twofold rotation symmetries, which guarantees the quantization of the Berry phase around a 2D Weyl point even in the presence of strong spin-orbit coupling. Pair creation and pair annihilation of Weyl points accompanying partner exchange between different pairs induces a jump of a 2D Z_{2} topological invariant leading to a topological phase transition. According to our theory, the topological phase transition in HgTe/CdTe quantum well structure is mediated by a stable 2D Weyl semimetal phase because the quantum well, lacking inversion symmetry intrinsically, has twofold rotation about the growth direction. Namely, the HgTe/CdTe quantum well can show 2D Weyl semimetallic behavior within a small but finite interval in the thickness of HgTe layers between a normal insulator and a quantum spin Hall insulator. We also propose that few-layer black phosphorus under perpendicular electric field is another candidate system to observe the unconventional topological phase transition mechanism accompanied by the emerging 2D Weyl semimetal phase protected by space-time inversion symmetry.

  5. Phase-space structures - I. A comparison of 6D density estimators

    Science.gov (United States)

    Maciejewski, M.; Colombi, S.; Alard, C.; Bouchet, F.; Pichon, C.

    2009-03-01

    In the framework of particle-based Vlasov systems, this paper reviews and analyses different methods recently proposed in the literature to identify neighbours in 6D space and estimate the corresponding phase-space density. Specifically, it compares smoothed particle hydrodynamics (SPH) methods based on tree partitioning to 6D Delaunay tessellation. This comparison is carried out on statistical and dynamical realizations of single halo profiles, paying particular attention to the unknown scaling, SG, used to relate the spatial dimensions to the velocity dimensions. It is found that, in practice, the methods with local adaptive metric provide the best phase-space estimators. They make use of a Shannon entropy criterion combined with a binary tree partitioning and with subsequent SPH interpolation using 10-40 nearest neighbours. We note that the local scaling SG implemented by such methods, which enforces local isotropy of the distribution function, can vary by about one order of magnitude in different regions within the system. It presents a bimodal distribution, in which one component is dominated by the main part of the halo and the other one is dominated by the substructures of the halo. While potentially better than SPH techniques, since it yields an optimal estimate of the local softening volume (and therefore the local number of neighbours required to perform the interpolation), the Delaunay tessellation in fact generally poorly estimates the phase-space distribution function. Indeed, it requires, prior to its implementation, the choice of a global scaling SG. We propose two simple but efficient methods to estimate SG that yield a good global compromise. However, the Delaunay interpolation still remains quite sensitive to local anisotropies in the distribution. To emphasize the advantages of 6D analysis versus traditional 3D analysis, we also compare realistic 6D phase-space density estimation with the proxy proposed earlier in the literature, Q = ρ/σ3

  6. The LTP Experiment on LISA Pathfinder: Operational Definition of TT Gauge in Space

    Science.gov (United States)

    Armano, Michele

    2011-10-01

    The European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA) are planning the Laser Interferometer Space Antenna (LISA) mission in order to detect GW. The need of accurate testing of free-fall and knowledge of noise in a space environment similar to LISA's is considered mandatory a pre-phase for the project. Therefore the LISA Pathfinder mission has been designed by ESA to fly the LISA Technology Package (LTP), aiming at testing free-fall by measuring the residual acceleration between two test-bodies in the dynamical scheme we address as "drag-free". The spectral map of the residual acceleration as function of frequency will convey information on the local noise level, thus producing a picture of the environmental working conditions for LISA itself. The thesis contains abundant material on the problem of compensating static gravity, the development of a theory of orthogonalization of reference and cross-talk for the LTP experiment. The construction of the laser detection procedure starting from GR and differential geometry arguments is carried on. Effort was put in pointing out the physical motivations for the choices made in several other papers by the author and colleagues. In this perspective the thesis is meant as a summary tool for the LTP collaboration. In the second part of the thesis we summarize our contributions for a measurement of G onboard LTP and review on possible tests of fundamental physics the mission might embody. A wide part of the thesis is now part of the LTP Operation Master Plan, describing the real science and operations onboard LISA Pathfinder. This thesis was defended on September 26th, 2006 at the University of Como, Italy.

  7. Space-Charge Experiments at the CERN Proton Synchrotron

    CERN Document Server

    Franchetti, Giuliano; Hofmann, I; Martini, M; Métral, E; Qiang, J; Ryne, D; Steerenberg, R; CFA Beam Dynamics Workshop “High Intensity and Brightness Hadron Beams”

    2005-01-01

    Benchmarking of the simulation codes used for the design of the next generation of high beam power accelerators is of paramount importance due to the very demanding requirements on the level of beam losses. This is usually accomplished by comparing simulation results against available theories, and more importantly, against experimental observations. To this aim, a number of well-defined test cases, obtained by accurate measurements made in existing machines, are of great interest. Such measurements have been made in the CERN Proton Synchrotron to probe three space-charge effects: (i) transverse emittance blow-up due to space-charge induced crossing of the integer or half-integer stop-band, (ii) space-charge and octupole driven resonance trapping, and (iii) intensity-dependent emittance transfer between the two transverse planes. The last mechanism is discussed in detail in this paper and compared to simulation predictions.

  8. Site Characterization of the Source Physics Experiment Phase II Location Using Seismic Reflection Data

    Science.gov (United States)

    Sexton, E. A.; Snelson, C. M.; Chipman, V.; Emer, D. F.; White, R. L.; Emmitt, R.; Wright, A. A.; Drellack, S.; Huckins-Gang, H.; Mercadante, J.; Floyd, M.; McGowin, C.; Cothrun, C.; Bonal, N.

    2013-12-01

    An objective of the Source Physics Experiment (SPE) is to identify low-yield nuclear explosions from a regional distance. Low-yield nuclear explosions can often be difficult to discriminate among the clutter of natural and man-made explosive events (e.g., earthquakes and mine blasts). The SPE is broken into three phases. Phase I has provided the first of the physics-based data to test the empirical models that have been used to discriminate nuclear events. The Phase I series of tests were placed within a highly fractured granite body. The evolution of the project has led to development of Phase II, to be placed within the opposite end member of geology, an alluvium environment, thereby increasing the database of waveforms to build upon in the discrimination models. Both the granite and alluvium sites have hosted nearby nuclear tests, which provide comparisons for the chemical test data. Phase III of the SPE is yet to be determined. For Phase II of the experiment, characterization of the location is required to develop the geologic/geophysical models for the execution of the experiment. Criteria for the location are alluvium thickness of approximately 170 m and a water table below 170 m; minimal fracturing would be ideal. A P-wave mini-vibroseis survey was conducted at a potential site in alluvium to map out the subsurface geology. The seismic reflection profile consisted of 168 geophone stations, spaced 5 m apart. The mini-vibe was a 7,000-lb peak-force source, starting 57.5 m off the north end of the profile and ending 57.5 m past the southern-most geophone. The length of the profile was 835 m. The source points were placed every 5 m, equally spaced between geophones to reduce clipping. The vibroseis sweep was from 20 Hz down to 180 Hz over 8 seconds, and four sweeps were stacked at each shot location. The shot gathers show high signal-to-noise ratios with clear first arrivals across the entire spread and the suggestion of some shallow reflectors. The data were

  9. Review article: Wave analysis methods for space plasma experiment

    Science.gov (United States)

    Narita, Yasuhito

    2017-05-01

    A review of analysis methods is given on quasi-monochromatic waves, turbulent fluctuations, and wave-wave and wave-particle interactions for single-spacecraft data in situ in near-Earth space and interplanetary space, in particular using magnetic field and electric field data. Energy spectra for different components of the fluctuating fields, minimum variance analysis, propagation and polarization properties of electromagnetic waves, wave distribution function, helicity quantities, higher-order statistics, and detection methods for wave-particle interactions are explained.

  10. Quantum effects in nanosystems: Good reasons to use phase-space Weyl symbols

    Science.gov (United States)

    Vaia, Ruggero

    2016-12-01

    Bogoliubov transformations have been successfully applied in several condensed-matter contexts, e.g., in the theory of superconductors, superfluids, and antiferromagnets. These applications are based on bulk models where translation symmetry can be assumed, so that few degrees of freedom in Fourier space can be "diagonalized" separately, and in this way it is easy to find the approximate ground state and its excitations. As translation symmetry cannot be invoked when it comes to nanoscopic systems, the corresponding multidimensional Bogoliubov transformations are more complicated. For bosonic systems it is much simpler to proceed using phase-space variables, i.e., coordinates and momenta. Interactions can be accounted for by the self-consistent harmonic approximation, which is naturally developed using phase-space Weyl symbols. The spin-flop transition in a short antiferromagnetic chain is illustrated as an example. This approach, rarely used in the past, is expected to be generally useful to estimate quantum effects, e.g., on phase diagrams of ordered vs disordered phases.

  11. Experimental demonstration of electron longitudinal-phase-space linearization by shaping the photoinjector laser pulse.

    Science.gov (United States)

    Penco, G; Danailov, M; Demidovich, A; Allaria, E; De Ninno, G; Di Mitri, S; Fawley, W M; Ferrari, E; Giannessi, L; Trovó, M

    2014-01-31

    Control of the electron-beam longitudinal-phase-space distribution is of crucial importance in a number of accelerator applications, such as linac-driven free-electron lasers, colliders and energy recovery linacs. Some longitudinal-phase-space features produced by nonlinear electron beam self- fields, such as a quadratic energy chirp introduced by geometric longitudinal wakefields in radio-frequency (rf) accelerator structures, cannot be compensated by ordinary tuning of the linac rf phases nor corrected by a single high harmonic accelerating cavity. In this Letter we report an experimental demonstration of the removal of the quadratic energy chirp by properly shaping the electron beam current at the photoinjector. Specifically, a longitudinal ramp in the current distribution at the cathode linearizes the longitudinal wakefields in the downstream linac, resulting in a flat electron current and energy distribution. We present longitudinal-phase-space measurements in this novel configuration compared to those typically obtained without longitudinal current shaping at the FERMI linac.

  12. Experiments as Liminal Learning Spaces in Leadership Development

    DEFF Research Database (Denmark)

    Kjærgaard, Annemette; Meier, Frank; Tangkjær, Christian

    In this paper we address the question of what professional practitioner students learn from experiments in leadership development programs. Drawing from our own design and teaching in a leadership programme, we explore how certain models and frameworks become threshold concepts for students...... practical implications for using threshold concepts in designing experiments in leadership development education for professional practitioners....

  13. From Undersea to Outer Space: The STS-40 Jellyfish Experiment

    Science.gov (United States)

    1994-01-01

    This is an educational production featuring 'Ari', animated jellyfish who recounts his journey into space. Jellyfish were flown aboard the shuttle to study the effects of microgravity on living organisms. Topics Ari explores are: microgravity, life sciences, similarities between jellyfish and humans, and the life cycle and anatomy of a jellyfish.

  14. Life science research objectives and representative experiments for the space station

    Science.gov (United States)

    Johnson, Catherine C. (Editor); Arno, Roger D. (Editor); Mains, Richard (Editor)

    1989-01-01

    A workshop was convened to develop hypothetical experiments to be used as a baseline for space station designer and equipment specifiers to ensure responsiveness to the users, the life science community. Sixty-five intra- and extramural scientists were asked to describe scientific rationales, science objectives, and give brief representative experiment descriptions compatible with expected space station accommodations, capabilities, and performance envelopes. Experiment descriptions include hypothesis, subject types, approach, equipment requirements, and space station support requirements. The 171 experiments are divided into 14 disciplines.

  15. Setting priorities for space research: An experiment in methodology

    Science.gov (United States)

    1995-01-01

    In 1989, the Space Studies Board created the Task Group on Priorities in Space Research to determine whether scientists should take a role in recommending priorities for long-term space research initiatives and, if so, to analyze the priority-setting problem in this context and develop a method by which such priorities could be established. After answering the first question in the affirmative in a previous report, the task group set out to accomplish the second task. The basic assumption in developing a priority-setting process is that a reasoned and structured approach for ordering competing initiatives will yield better results than other ways of proceeding. The task group proceeded from the principle that the central criterion for evaluating a research initiative must be its scientific merit -- the value of the initiative to the proposing discipline and to science generally. The group developed a two-stage methodology for priority setting and constructed a procedure and format to support the methodology. The first of two instruments developed was a standard format for structuring proposals for space research initiatives. The second instrument was a formal, semiquantitative appraisal procedure for evaluating competing proposals. This report makes available complete templates for the methodology, including the advocacy statement and evaluation forms, as well as an 11-step schema for a priority-setting process. From the beginning of its work, the task group was mindful that the issue of priority setting increasingly pervades all of federally supported science and that its work would have implications extending beyond space research. Thus, although the present report makes no recommendations for action by NASA or other government agencies, it provides the results of the task group's work for the use of others who may study priority-setting procedures or take up the challenge of implementing them in the future.

  16. Phase-space approach to lensless measurements of optical field correlations.

    Science.gov (United States)

    Sharma, Katelynn A; Brown, Thomas G; Alonso, Miguel A

    2016-07-11

    We analyze and test a general approach for efficiently measuring space-variant partially coherent quasi-monochromatic fields using only amplitude masks and free propagation. A phase-space description is presented to analyze approaches of this type and understand their limitations. Three variants of the method are discussed and compared, the first using an aperture mask, the second employing both an obstacle (the exact inverse of the aperture) and a clear mask, and the last combining the previous two. We discuss the advantages and disadvantages of each option.

  17. James Webb Space Telescope segment phasing using differential optical transfer functions.

    Science.gov (United States)

    Codona, Johanan L; Doble, Nathan

    2015-03-01

    Differential optical transfer function (dOTF) is an image-based, noniterative wavefront sensing method that uses two star images with a single small change in the pupil. We describe two possible methods for introducing the required pupil modification to the James Webb Space Telescope, one using a small (telescope can be measured simultaneously. Also, since dOTF gives the pupil field amplitude as well as the phase, it could provide a first approximation or constraint to the planned iterative phase retrieval algorithms.

  18. [Lunar phases and incidence of spontaneous deliveries. Our experience].

    Science.gov (United States)

    Periti, E; Biagiotti, R

    1994-01-01

    To evaluate the relationship between lunar phases and birthrate. We examined 7842 spontaneous deliveries at Obstetric and Gynaecologic Clinic of University of Florence, between January 1988 and November 1992, covering 58 synodic lunar months. A lunar month was considered to be a period of 29.5 days and comprised four lunar phases: the full moon, the last quarter, the new moon and the first quarter. We compared the median number of births in each day of synodic month and in the periods of seven days centered on the first day of each moon phase. Statistical analysis was performed using the Kruskal-Wallis one-way analysis by ranks. Non significant differences were found in the incidence of spontaneous birth throughout the lunar cycle. These results do not support the hypothesis of a relationship between moon-phase changes and the incidence of spontaneous deliveries.

  19. Embodied Space: a Sensorial Approach to Spatial Experience

    Science.gov (United States)

    Durão, Maria João

    2009-03-01

    A reflection is presented on the significance of the role of the body in the interpretation and future creation of spatial living structures. The paper draws on the body as cartography of sensorial meaning that includes vision, touch, smell, hearing, orientation and movement to discuss possible relationships with psychological and sociological parameters of 'sensorial space'. The complex dynamics of body-space is further explored from the standpoint of perceptual variables such as color, light, materialities, texture and their connections with design, technology, culture and symbology. Finally, the paper discusses the integration of knowledge and experimentation in the design of future habitats where body-sensitive frameworks encompass flexibility, communication, interaction and cognitive-driven solutions.

  20. Magnetic field amplification in electron phase-space holes and related effects

    Directory of Open Access Journals (Sweden)

    R. A. Treumann

    2012-04-01

    Full Text Available Three-dimensional electron phase-space holes are shown to have positive charges on the plasma background, which produce a radial electric field and force the trapped electron component into an azimuthal drift. In this way electron holes generate magnetic fields in the hole. We solve the cylindrical hole model exactly for the hole charge, electric potential and magnetic field. In electron holes, the magnetic field is amplified on the flux tube of the hole; equivalently, in ion holes the field would be decreased. The flux tube adjacent to the electron hole is magnetically depleted by the external hole dipole field. This causes magnetic filamentation. It is also shown that holes are massive objects, each carrying a finite magnetic moment. Binary magnetic dipole interaction of these moments will cause alignment of the holes into chains along the magnetic field or, in the three-dimensional case, produce a magnetic fabric in the volume of hole formation. Since holes, in addition to being carriers of charges and magnetic moments, also have finite masses, they behave like quasi-particles, performing E × B, magnetic field, and diamagnetic drifts. In an inhomogeneous magnetic field, their magnetic moments experience torque, which causes nutation of the hole around the direction of the magnetic field, presumably giving rise to low frequency magnetic modulations like pulsations. A gas of many such holes may allow for a kinetic description, in which holes undergo binary dipole interactions. This resembles the polymeric behaviour. Both magnetic field generation and magnetic structure formation are of interest in auroral, solar coronal and shock physics, in particular in the problem of magnetic field filamentation in relativistic foreshocks and cosmic ray acceleration.

  1. Canadian experience in space technology spin-offs

    Science.gov (United States)

    Chambers, J. G.; Price, P. J.

    1995-10-01

    Spin-off technologies and related benefits arise in various ways from, large space project, science programs and technology development programs. These benefits include specific spin-off products, new enterprises and the development of new and higher level of skills. In Canada, there are a variety of programs to encourage and support spin-off benefit generation. This paper reviews current and planned spin-off related programs, as well as identifying important examples of spin-off technologies.

  2. Cellular changes in microgravity and the design of space radiation experiments

    Science.gov (United States)

    Morrison, D. R.

    1994-01-01

    Cell metabolism, secretion and cell-cell interactions can be altered during space flight. Early radiobiology experiments have demonstrated synergistic effects of radiation and microgravity as indicated by increased mutagenesis, increased chromosome aberrations, inhibited development, and retarded growth. Microgravity-induced changes in immune cell functions include reduced blastogenesis and cell-mediated, delayed-type hypersensitivity responses, increased cytokine secretions, but inhibited cytotoxic effects an macrophage differentiation. These effects are important because of the high radiosensitivity of immune cells. It is difficult to compare ground studies with space radiation biology experiments because of the complexity of the space radiation environment, types of radiation damage and repair mechanisms. Altered intracellular functions and molecular mechanisms must be considered in the design and interpretation of space radiation experiments. Critical steps in radiocarcinogenesis could be affected. New cell systems and hardware are needed to determine the biological effectiveness of the low dose rate, isotropic, multispectral space radiation and the potential usefulness of radioprotectants during space flight.

  3. Cellular changes in microgravity and the design of space radiation experiments

    Science.gov (United States)

    Morrison, D. R.

    1994-10-01

    Cell metabolism, secretion and cell-cell interactions can be altered during space flight. Early radiobiology experiments have demonstrated synergistic effects of radiation and microgravity as indicated by increased mutagenesis, increased chromosome aberrations, inhibited development, and retarded growth. Microgravity-induced changes in immune cell functions include reduced blastogenesis and cell-mediated, delayed-type hypersensitivity responses, increased cytokine secretions, but inhibited cytotoxic effects and macrophage differentiation. These effecrs are important because of the high radiosensitivity of immune cells. It is difficult to compare ground studies with space radiation biology experiments because of the complexity of the space radiation environment, types of radiation damage and repair mechanisms. Altered intracellular functions and molecular mechanisms must be considered in the design and interpretation of space radiation experiments. Critical steps in radiocarcinogenesis could be affected. New cell systems and hardware are needed to determine the biological effectiveness of the low dose rate, isotropic, multispectral space radiation and the potential usefulness of radioprotectants during space flight.

  4. Chaos control in delayed phase space constructed by the Takens embedding theory

    Science.gov (United States)

    Hajiloo, R.; Salarieh, H.; Alasty, A.

    2018-01-01

    In this paper, the problem of chaos control in discrete-time chaotic systems with unknown governing equations and limited measurable states is investigated. Using the time-series of only one measurable state, an algorithm is proposed to stabilize unstable fixed points. The approach consists of three steps: first, using Takens embedding theory, a delayed phase space preserving the topological characteristics of the unknown system is reconstructed. Second, a dynamic model is identified by recursive least squares method to estimate the time-series data in the delayed phase space. Finally, based on the reconstructed model, an appropriate linear delayed feedback controller is obtained for stabilizing unstable fixed points of the system. Controller gains are computed using a systematic approach. The effectiveness of the proposed algorithm is examined by applying it to the generalized hyperchaotic Henon system, prey-predator population map, and the discrete-time Lorenz system.

  5. Nonclassical phase-space trajectories for the damped harmonic quantum oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Pachon, L.A. [Departamento de Fisica, Universidad Nacional de Colombia, Bogota D.C. (Colombia); Institut fuer Physik, Universitaet Augsburg, Universitaetsstrasse 1, D-86135 Augsburg (Germany); CeiBA - Complejidad, Bogota D.C. (Colombia); Ingold, G.-L., E-mail: gert.ingold@physik.uni-augsburg.de [Institut fuer Physik, Universitaet Augsburg, Universitaetsstrasse 1, D-86135 Augsburg (Germany); Dittrich, T. [Departamento de Fisica, Universidad Nacional de Colombia, Bogota D.C. (Colombia); CeiBA - Complejidad, Bogota D.C. (Colombia)

    2010-10-05

    Graphical abstract: The phase-space path-integral approach to the damped harmonic oscillator is analyzed beyond the Markovian approximation and the appearance of nonclassical trajectories is discussed. - Abstract: The phase-space path-integral approach to the damped harmonic oscillator is analyzed beyond the Markovian approximation. It is found that pairs of nonclassical trajectories contribute to the path-integral representation of the Wigner propagating function. Due to the linearity of the problem, the sum coordinate of a pair still satisfies the classical equation of motion. Furthermore, it is shown that the broadening of the Wigner propagating function of the damped oscillator arises due to the time-nonlocal interaction mediated by the heat bath.

  6. Multiturn extraction and injection by means of adiabatic capture in stable islands of phase space

    CERN Document Server

    Cappi, R

    2004-01-01

    Recently a novel approach has been proposed for performing multiturn extraction from a circular machine. Such a technique consists of splitting the beam by means of stable islands created in transverse phase space by magnetic elements creating nonlinear fields, such as sextupoles and octupoles. Provided a slow time variation of the linear tune is applied, adiabatic with respect to the betatron motion, the islands can be moved in phase space and eventually charged particles may be trapped inside the stable structures. This generates a certain number of well-separated beamlets. Originally, this principle was successfully tested using a fourth-order resonance. In this paper the approach is generalized by considering other types of resonances as well as the possibility of performing multiple multiturn extractions. The results of numerical simulations are presented and described in detail. Of course, by time reversal, the proposed approach could be used also for multiturn injection.

  7. Phase-space approach to solving the time-independent Schrödinger equation.

    Science.gov (United States)

    Shimshovitz, Asaf; Tannor, David J

    2012-08-17

    We propose a method for solving the time-independent Schrödinger equation based on the von Neumann (vN) lattice of phase space Gaussians. By incorporating periodic boundary conditions into the vN lattice [F. Dimler et al., New J. Phys. 11, 105052 (2009)], we solve a longstanding problem of convergence of the vN method. This opens the door to tailoring quantum calculations to the underlying classical phase space structure while retaining the accuracy of the Fourier grid basis. The method has the potential to provide enormous numerical savings as the dimensionality increases. In the classical limit, the method reaches the remarkable efficiency of one basis function per one eigenstate. We illustrate the method for a challenging two-dimensional potential where the Fourier grid method breaks down.

  8. Symmetry Transformation in Extended Phase Space: the Harmonic Oscillator in the Husimi Representation

    Directory of Open Access Journals (Sweden)

    Sadolah Nasiri

    2008-02-01

    Full Text Available In a previous work the concept of quantum potential is generalized into extended phase space (EPS for a particle in linear and harmonic potentials. It was shown there that in contrast to the Schrödinger quantum mechanics by an appropriate extended canonical transformation one can obtain the Wigner representation of phase space quantum mechanics in which the quantum potential is removed from dynamical equation. In other words, one still has the form invariance of the ordinary Hamilton-Jacobi equation in this representation. The situation, mathematically, is similar to the disappearance of the centrifugal potential in going from the spherical to the Cartesian coordinates. Here we show that the Husimi representation is another possible representation where the quantum potential for the harmonic potential disappears and the modified Hamilton-Jacobi equation reduces to the familiar classical form. This happens when the parameter in the Husimi transformation assumes a specific value corresponding to Q-function.

  9. Pbar Beam Stacking in the Recycler by Longitudinal Phase-space Coating

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, C. M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2013-08-06

    Barrier rf buckets have brought about new challenges in longitudinal beam dynamics of charged particle beams in synchrotrons and at the same time led to many new remarkable prospects in beam handling. In this paper, I describe a novel beam stacking scheme for synchrotrons using barrier buckets without any emittance dilution to the beam. First I discuss the general principle of the method, called longitudinal phase-space coating. Multi-particle beam dynamics simulations of the scheme applied to the Recycler, convincingly validates the concepts and feasibility of the method. Then I demonstrate the technique experimentally in the Recycler and also use it in operation. A spin-off of this scheme is its usefulness in mapping the incoherent synchrotron tune spectrum of the beam particles in barrier buckets and producing a clean hollow beam in longitudinal phase space. Both of which are described here in detail with illustrations. The beam stacking scheme presented here is the first of its kind.

  10. Subcritical Growth of Electron Phase-space Holes in Planetary Radiation Belts

    Science.gov (United States)

    Osmane, Adnane; Turner, Drew L.; Wilson, Lynn B.; Dimmock, Andrew P.; Pulkkinen, Tuija I.

    2017-09-01

    The discovery of long-lived electrostatic coherent structures with large-amplitude electric fields (1≤slant E ≤slant 500 mV/m) by the Van Allen Probes has revealed alternative routes through which planetary radiation belts’ acceleration can take place. Following previous reports showing that small phase-space holes, with qφ /{T}ec≃ {10}-2{--}{10}-3, could result from electron interaction with large-amplitude whistlers, we demonstrate one possible mechanism through which holes can grow nonlinearly (I.e., γ \\propto \\sqrt{φ }) and subcritically as a result of momentum exchange between hot and cold electron populations. Our results provide an explanation for the common occurrence and fast growth of large-amplitude electron phase-space holes in the Earth’s radiation belts.

  11. Recent progress on phase-space turbulence and dynamical response in collisionless plasmas

    CERN Document Server

    Lesur, Maxime

    2013-01-01

    In the presence of wave dissipation, phase-space structures emerge in nonlinear Vlasov dynamics. Their dynamics can lead to a nonlinear continuous shifting of the wave frequency (chirping). This report summarizes my personal contribution to these topics in the fiscal year 2012. The effects of collisions on chirping characteristics were investigated, with a one-dimensional beam-plasma kinetic model. The long-time nonlinear evolution was systematically categorized as damped, steady-state, periodic, chaotic and chirping. The chirping regime was sub-categorized as periodic, chaotic, bursty, and intermittent. Existing analytic theory was extended to account for Krook-like collisions. Relaxation oscillations, associated with chirping bursts, were investigated in the presence of dynamical friction and velocity-diffusion. The period increases with decreasing drag, and weakly increases with decreasing diffusion. A new theory gives a simple relation between the growth of phase-space structures and that of the wave ener...

  12. Halftone information hiding technology based on phase feature of space filling curves

    Science.gov (United States)

    Hu, Jianhua; Cao, Peng; Dong, Zhihong; Cao, Xiaohe

    2017-08-01

    To solve the problems of the production of interference fringes (namely moiré in printing) and improve the image quality in printing process of halftone screening for information hiding, a halftone screening security technique based on the phase feature of space filling curves is studied in this paper. This method effectively solves the problem of moire and optimizes the quality of the screening, so that the images presented after screening have achieved good visual effect. The pseudo-random scrambling encryption of the plaintext information and the halftone screening technique based on the phase feature of the space filling curves are carried out when screening,which not only eliminates the common moire in the screening but also improves the image quality and the security of information.

  13. End-fire silicon optical phased array with half-wavelength spacing

    Science.gov (United States)

    Kossey, Michael R.; Rizk, Charbel; Foster, Amy C.

    2018-01-01

    We demonstrate an optical phased array with emitting elements spaced at half the operational wavelength. The device is a one-dimensional array fabricated on an integrated silicon platform for operation at a wavelength of 1.55 μm. Light is emitted end-fire from the chip edge where the waveguides are terminated. The innovative design and high confinement afforded by the silicon waveguides enables λ/2 spacing (775-nm pitch) at the output thereby eliminating grating lobes and maximizing the power in the main lobe. Steering is achieved by inducing a phase shift between the waveguide feeds via integrated thermo-optic heaters. The device forms a beam with a full-width half-maximum angular width of 17°, and we demonstrate beam steering over a 64° range limited only by the element factor.

  14. Phase-space quantum control; Quantenkontrolle im Zeit-Frequenz-Phasenraum

    Energy Technology Data Exchange (ETDEWEB)

    Fechner, Susanne

    2008-08-06

    The von Neumann-representation introduced in this thesis describes each laser pulse in a one-to-one manner as a sum of bandwidth-limited, Gaussian laser pulses centered around different points in phase space. These pulses can be regarded as elementary building blocks from which every single laser pulse can be constructed. The von Neumann-representation combines different useful properties for applications in quantum control. First, it is a one-to-one map between the degrees of freedom of the pulse shaper and the phase-space representation of the corresponding shaped laser pulse. In other words: Every possible choice of pulse shaper parameters corresponds to exactly one von Neumann-representation and vice versa. Moreover, since temporal and spectral structures become immediately sizable, the von Neumann-representation, as well as the Husimi- or the Wigner-representations, allows for an intuitive interpretation of the represented laser pulse. (orig.)

  15. Phase Space Analysis of a Gravitationally-Induced, Steady-State Nonequilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Sheehan, D.P.; Tobe, R. [Univ. of San Diego, CA (United States). Dept. of Physics; Glick, J.; Langton, J.A.; Gagliardi, M. [Univ. of San Diego, CA (United States). Dept. of Mathematics and Computer Science; Duncan, T. [Portland State Univ., OR (United States). Center for Science Ed.

    2002-04-01

    Recently a new type of pressure gradient was introduced, a gravitationally-induced, dynamically-maintained, steady-state pressure gradient (GDSPG). In this paper, three dimensional numerical test particle simulations detail its phase space structure. These verify the underlying physical mechanism originally hypothesized for its operation and support key assumptions upon which it is based. The GDSPG appears to be a member of a more general class of steady-state nonequilibrium systems that arise under extreme thermodynamic conditions.

  16. Generation of a novel phase-space-based cylindrical dose kernel for IMRT optimization.

    Science.gov (United States)

    Zhong, Hualiang; Chetty, Indrin J

    2012-05-01

    Improving dose calculation accuracy is crucial in intensity-modulated radiation therapy (IMRT). We have developed a method for generating a phase-space-based dose kernel for IMRT planning of lung cancer patients. Particle transport in the linear accelerator treatment head of a 21EX, 6 MV photon beam (Varian Medical Systems, Palo Alto, CA) was simulated using the EGSnrc/BEAMnrc code system. The phase space information was recorded under the secondary jaws. Each particle in the phase space file was associated with a beamlet whose index was calculated and saved in the particle's LATCH variable. The DOSXYZnrc code was modified to accumulate the energy deposited by each particle based on its beamlet index. Furthermore, the central axis of each beamlet was calculated from the orientation of all the particles in this beamlet. A cylinder was then defined around the central axis so that only the energy deposited within the cylinder was counted. A look-up table was established for each cylinder during the tallying process. The efficiency and accuracy of the cylindrical beamlet energy deposition approach was evaluated using a treatment plan developed on a simulated lung phantom. Profile and percentage depth doses computed in a water phantom for an open, square field size were within 1.5% of measurements. Dose optimized with the cylindrical dose kernel was found to be within 0.6% of that computed with the nontruncated 3D kernel. The cylindrical truncation reduced optimization time by approximately 80%. A method for generating a phase-space-based dose kernel, using a truncated cylinder for scoring dose, in beamlet-based optimization of lung treatment planning was developed and found to be in good agreement with the standard, nontruncated scoring approach. Compared to previous techniques, our method significantly reduces computational time and memory requirements, which may be useful for Monte-Carlo-based 4D IMRT or IMAT treatment planning.

  17. Bopp operators and phase-space spin dynamics: application to rotational quantum Brownian motion

    Energy Technology Data Exchange (ETDEWEB)

    Zueco, D [Departamento de Fisica de la Materia Condensada e, Instituto de Ciencia de Materiales de Aragon, C.S.I.C.-Universidad de Zaragoza, E-50009 Zaragoza (Spain); Calvo, I [Laboratorio Nacional de Fusion, Asociacion EURATOM-CIEMAT, E-28040 Madrid (Spain)

    2007-04-27

    For non-relativistic spinless particles, Bopp operators give an elegant and simple way to compute the dynamics of quasiprobability distributions in the phase-space formulation of Quantum Mechanics. In this work, we present a generalization of Bopp operators for spins and apply our results to the case of open spin systems. This approach allows to take the classical limit in a transparent way, recovering the corresponding Fokker-Planck equation.

  18. Collective motion in the frame of phase space moments (Nuclear scissors)

    Energy Technology Data Exchange (ETDEWEB)

    Balbutsev, E B, E-mail: balbuts@thsun1.jinr.r [Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region (Russian Federation)

    2010-01-01

    We consider the phase space moments (or Wigner Function Moments (WFM)) method, which is developed to describe the collective motion. The method is generalized to take into account pair correlations. Its connection with RPA and Green's function method is analyzed in the simple model, the Harmonic Oscillator with Quadrupole-Quadrupole (HO+QQ) interaction. Possibilities of WFM method are demonstrated on an example of the nuclear scissors mode.

  19. Phase-space representation of non-classical behaviour of scalar wave-fields

    Energy Technology Data Exchange (ETDEWEB)

    Canas-Cardona, Gustavo; Castaneda, Roman [Physics School, Universidad Nacional de Colombia Sede Medellin, A.A. 3840 Medellin (Colombia); Vinck-Posada, Herbert, E-mail: gcanas@unal.edu.co [Physics Department, Universidad Nacional de Colombia Sede Bogota, Bogota D.C (Colombia)

    2011-01-01

    The modelling of optical fields by using radiant and virtual point sources for the spatial coherence wavelets in the phase-space representation evidences some effects, conventionally attributed to non-classical correlations of light, although such type of correlations are not explicitly included in the model. Specifically, a light state is produced that has similar morphology to the Wigner Distribution Function of the well-known quantum Schroedinger cat and squeezed states.

  20. Communication: phase space approach to laser-driven electronic wavepacket propagation.

    Science.gov (United States)

    Takemoto, Norio; Shimshovitz, Asaf; Tannor, David J

    2012-07-07

    We propose a phase space method to propagate a quantum wavepacket driven by a strong external field. The method employs the periodic von Neumann basis with biorthogonal exchange recently introduced for the calculation of the energy eigenstates of time-independent quantum systems [A. Shimshovitz and D. J. Tannor, Phys. Rev. Lett. (in press) [e-print arXiv:1201.2299v1

  1. Exploring Inpatients' Experiences of Healing and Healing Spaces

    Directory of Open Access Journals (Sweden)

    Lorissa MacAllister PhD, AIA

    2016-12-01

    Full Text Available In order to understand a patient’s healing experience it is essential to understand the elements that they, the patient, believes contributed to their healing. Previous research has focused on symptom reducers or contributors through environment such as stress. A person’s experience of healing happens over time not instantaneous. Therefore, in this study, the interviews with patients happened after forty-eight hours of hospitalization. This mixed methods study describes the experiences of seventeen inpatients from two healthcare systems using a phenomenological approach combined with evidence based design evaluation methods to document the setting. The qualitative data was analyzed first for reoccurring themes then further explored and defined through quantitative environmental observations. The seventeen patients defined healing as “getting better/well.” Seventy three statements were recorded about contributors and detractors to healing in the physical environment. Three primary themes emerged from the data as positive influencers of a healing experience: being cared for, being comfortable and experiencing something familiar or like home. These results demonstrate that patients perceive their inpatient healing experience through a supported environment.

  2. Big Science, Small-Budget Space Experiment Package Aka MISSE-5: A Hardware And Software Perspective

    Science.gov (United States)

    Krasowski, Michael; Greer, Lawrence; Flatico, Joseph; Jenkins, Phillip; Spina, Dan

    2007-01-01

    Conducting space experiments with small budgets is a fact of life for many design groups with low-visibility science programs. One major consequence is that specialized space grade electronic components are often too costly to incorporate into the design. Radiation mitigation now becomes more complex as a result of being restricted to the use of commercial off-the-shelf (COTS) parts. Unique hardware and software design techniques are required to succeed in producing a viable instrument suited for use in space. This paper highlights some of the design challenges and associated solutions encountered in the production of a highly capable, low cost space experiment package.

  3. NASA uses Eclipse RCP Applications for Experiments on the International Space Station

    Science.gov (United States)

    Cohen, Tamar

    2013-01-01

    Eclipse is going to space for the first time in 2013! The International Space Station (ISS) is used as a site for experiments any software developed as part of these experiments has to comply with extensive and strict user interface guidelines. NASA Ames Research Center's Intelligent Robotics Group is doing 2 sets of experiments, both with astronauts using Eclipse RCP applications to remotely control robots. One experiment will control SPHERES with an Android Smartphone on the ISS the other experiment will control a K10 rover on Earth.

  4. Defending against Internet worms using a phase space method from chaos theory

    Science.gov (United States)

    Hu, Jing; Gao, Jianbo; Rao, Nageswara S.

    2007-04-01

    Enterprise networks are facing ever-increasing security threats from Distributed Denial of Service (DDoS) attacks, worms, viruses, intrusions, Trojans, port scans, and network misuses, and thus effective monitoring approaches to quickly detect these activities are greatly needed. In this paper, we employ chaos theory and propose an interesting phase space method to detect Internet worms. An Internet worm is a self-propagating program that automatically replicates itself to vulnerable systems and spreads across the Internet. Most deployed worm-detection systems are signature-based. They look for specific byte sequences (called attack signatures) that are known to appear in the attack traffic. Conventionally, the signatures are manually identified by human experts through careful analysis of the byte sequence from captured attack traffic. We propose to embed the traffic sequence to a high-dimensional phase space using chaos theory. We have observed that the signature sequence of a specific worm will occupy specific regions in the phase space, which may be appropriately called the invariant subspace of the worm. The invariant subspace of the worm separates itself widely from the subspace of the normal traffic. This separation allows us to construct three simple metrics, each of which completely separates 100 normal traffic streams from 200 worm traffic streams, without training in the conventional sense. Therefore, the method is at least as accurate as any existing methods. More importantly, our method is much faster than existing methods, such as based on expectation maximization and hidden Markov models.

  5. Phase-space dynamics of opposition control in wall-bounded turbulent flows

    Science.gov (United States)

    Hwang, Yongyun; Ibrahim, Joseph; Yang, Qiang; Doohan, Patrick

    2017-11-01

    The phase-space dynamics of wall-bounded shear flow in the presence of opposition control is explored by examining the behaviours of a pair of nonlinear equilibrium solutions (exact coherent structures), edge state and life time of turbulence at low Reynolds numbers. While the control modifies statistics and phase-space location of the edge state and the lower-branch equilibrium solution very little, it is also found to regularise the periodic orbit on the edge state by reverting a period-doubling bifurcation. Only the upper-branch equilibrium solution and mean turbulent state are significantly modified by the control, and, in phase space, they gradually approach the edge state on increasing the control gain. It is found that this behaviour results in a significant reduction of the life time of turbulence, indicating that the opposition control significantly increases the probability that the turbulent solution trajectory passes through the edge state. Finally, it is shown that the opposition control increases the critical Reynolds number of the onset of the equilibrium solutions, indicating its capability of transition delay. This work is sponsored by the Engineering and Physical Sciences Research Council (EPSRC) in the UK (EP/N019342/1).

  6. Subcritical Growth of Electron Phase-space Holes in Planetary Radiation Belts

    Science.gov (United States)

    Osmane, A.; Wilson, L. B., III; Turner, D. L.; Dimmock, A. P.; Pulkkinen, T. I.

    2017-12-01

    The discovery of self-sustained coherent structures with large-amplitude electric fields (E ˜ 10 - 100 mV/m) by the Van Allen Probes has revealed alternative routes through which energy-momentum exchange can take place in planetary radiation belts. When originating from energetic electrons in Landau resonance with large-amplitude whistlers, phase-space electron holes form with small amplitudes of the order of the hot to cold electron density, i.e., qφ/T_e≃ n_h/n_c ≃ 10^{-3}, and orders of magnitude smaller than observed values of the largest phase-space holes amplitude, i.e., qφ /T_e ≃ 1. In this report we present a mechanism through which electron holes can grow nonlinearly (i.e. γ ∝ √{φ}) and subcritically as a result of momentum exchange with passing (untrapped) electrons. Growth rates are computed analytically for plasma parameters consistent with those measured in the Earth's radiation belts under quiet and disturbed conditions. Our results provide an explanation for the fast growth of electron phase-space holes in the Earth's radiation belts from small initial values qφ/T_c ≃ 10^{-3}, to larger values of the order qφ /T_e ≃ 1.

  7. Small craters on the meteoroid and space debris impact experiment

    Science.gov (United States)

    Humes, Donald H.

    1995-01-01

    Examination of 9.34 m(exp 2) of thick aluminum plates from the Long Duration Exposure Facility (LDEF) using a 25X microscope revealed 4341 craters that were 0.1 mm in diameter or larger. The largest was 3 mm in diameter. Most were roughly hemispherical with lips that were raised above the original plate surface. The crater diameter measured was the diameter at the top of the raised lips. There was a large variation in the number density of craters around the three-axis gravity-gradient stabilized spacecraft. A model of the near-Earth meteoroid environment is presented which uses a meteoroid size distribution based on the crater size distribution on the space end of the LDEF. An argument is made that nearly all the craters on the space end must have been caused by meteoroids and that very few could have been caused by man-made orbital debris. However, no chemical analysis of impactor residue that will distinguish between meteoroids and man-made debris is yet available. A small area (0.0447 m(exp 2)) of one of the plates on the space end was scanned with a 200X microscope revealing 155 craters between 10 micron and 100 micron in diameter and 3 craters smaller than 10 micron. This data was used to extend the size distribution of meteoroids down to approximately 1 micron. New penetration equations developed by Alan Watts were used to relate crater dimensions to meteoroid size. The equations suggest that meteoroids must have a density near 2.5 g/cm(exp 3) to produce craters of the shape found on the LDEF. The near-Earth meteoroid model suggests that about 80 to 85 percent of the 100 micron to 1 mm diameter craters on the twelve peripheral rows of the LDEF were caused by meteoroids, leaving 15 to 20 percent to be caused by man-made orbital debris.

  8. Still Life. The Experience of Space in Modernist Prose

    DEFF Research Database (Denmark)

    Tygstrup, Frederik

    2007-01-01

    for a collective and multifarious view of literary modernism in various genres, locations, and languages. Asking and responding to a wealth of theoretical, aesthetic, and historical questions, 65 scholars from several countries test the usefulness of the concept of modernism as they probe a variety of contexts...... to philosophical, environmental, urban, and political domains, including issues of race and space, gender and fashion, popular culture and trauma, science and exile, ­all of which have an urgent bearing on the poetics of modernity...

  9. Overview of the Field Phase of the NASA Tropical Cloud Systems and Processes (TCSP)Experiment

    Science.gov (United States)

    Hood, Robbie E.; Zipser, Edward; Heymsfield, Gerald M.; Kakar, Ramesh; Halverson Jeffery; Rogers, Robert; Black, Michael

    2006-01-01

    The Tropical Cloud Systems and Processes experiment is sponsored by the National Aeronautics and Space Administration (NASA) to investigate characteristics of tropical cyclone genesis, rapid intensification and rainfall using a three-pronged approach that emphasizes satellite information, suborbital observations and numerical model simulations. Research goals include demonstration and assessment of new technology, improvements to numerical model parameterizations, and advancements in data assimilation techniques. The field phase of the experiment was based in Costa Rica during July 2005. A fully instrumented NASA ER-2 high altitude airplane was deployed with Doppler radar, passive microwave instrumentation, lightning and electric field sensors and an airborne simulator of visible and infrared satellite sensors. Other assets brought to TCSP were a low flying uninhabited aerial vehicle, and a surface-based radiosonde network. In partnership with the Intensity Forecasting Experiment of the National Oceanic and Atmospheric Administration (NOAA) Hurricane Research Division, two NOAA P-3 aircraft instrumented with radar, passive microwave, microphysical, and dropsonde instrumentation were also deployed to Costa Rica. The field phase of TCSP was conducted in Costa Rica to take advantage of the geographically compact tropical cyclone genesis region of the Eastern Pacific Ocean near Central America. However, the unusual 2005 hurricane season provided numerous opportunities to sample tropical cyclone development and intensification in the Caribbean Sea and Gulf of Mexico as well. Development of Hurricane Dennis and Tropical Storm Gert were each investigated over several days in addition to Hurricane Emily as it was close to Saffir-Simpson Category 5 intensity. An overview of the characteristics of these storms along with the pregenesis environment of Tropical Storm Eugene in the Eastern Pacific will be presented.

  10. The new JET phased ICRH array: first experiments and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Bures, M.; Bhatnagar, V.; Brown, T.; Fechner, B.; Gormezano, C.; Kaye, A.; Lennholm, M.; Righi, E.; Rimini, F.; Sibley, A.; Start, D.; Wade, T. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Goulding, R. [Oak Ridge National Lab., TN (United States); Lamalle, P. [Ecole Royale Militaire, Brussels (Belgium). Lab. de Physique des Plasmas; Nguyen, F. [CEA Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France)

    1994-07-01

    New ICRH antennas on JET were designed to couple to the new JET divertor plasma configurations and to improve the Fast Wave Current Drive (FWCD) capabilities. The A2 antenna consists of 4 straps whose currents can be phased at arbitrary angles. The real time automatic tuning acts on frequency, line length (line phase shifters) and stub length. Provision is made for the coupling resistance/plasma position feedback to accommodate the fast changes in antenna loading. The first coupling, tuning and heating results are reported in 0{pi}0{pi}, 0000 and 00{pi}{pi} phasing. A new antenna model is described, which was developed to simulate the measured antenna loading in terms of plasma parameters and to provide a starting point for the real time automatic tuning. 5 refs., 4 figs.

  11. Waves In Space Plasmas (WISP): A space plasma lab active experiment

    Science.gov (United States)

    Fredricks, R. W.

    1983-01-01

    The Waves in Space Plasmas (WISP) series of Spacelab Space Plasma Labs devoted to active experimentation, are introduced. Space Plasma Lab-1 is keyed to active probing of the ionosphere and magnetosphere using controlled wave injections by the WISP VLF and HF transmitters, supported by a free-flying plasma diagnostics package instrumented with wave receivers and particle probe diagnostics, designed to measure radiation and propagation of plasma waves, precipitated particle fluxes due to wave/particle interactions, and similar phenomena resulting from wave injectons. The VLF transmitter delivers up to 1 kW of RF power into the antenna terminals over the range from 0.3 to 30 kHz. The HF transmitter delivers up to 500 W to the antenna over the range from 1 to 30 MHz. A dipole antenna commandable to any extension up to 300 m tip-to-tip is available.

  12. Development of a coal fired pulse combustor for residential space heating. Phase I, Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1988-04-01

    This report presents the results of the first phase of a program for the development of a coal-fired residential combustion system. This phase consisted of the design, fabrication, testing, and evaluation of an advanced pulse combustor sized for residential space heating requirements. The objective was to develop an advanced pulse coal combustor at the {approximately} 100,000 Btu/hr scale that can be integrated into a packaged space heating system for small residential applications. The strategy for the development effort included the scale down of the feasibility unit from 1-2 MMBtu/hr to 100,000 Btu/hr to establish a baseline for isolating the effect of scale-down and new chamber configurations separately. Initial focus at the residential scale was concentrated on methods of fuel injection and atomization in a bare metal unit. This was followed by incorporating changes to the advanced chamber designs and testing of refractory-lined units. Multi-fuel capability for firing oil or gas as a secondary fuel was also established. Upon completion of the configuration and component testing, an optimum configuration would be selected for integrated testing of the pulse combustor unit. The strategy also defined the use of Dry Ultrafine Coal (DUC) for Phases 1 and 2 of the development program with CWM firing to be a product improvement activity for a later phase of the program.

  13. The Cryogenic Test Bed experiments: Cryogenic heat pipe flight experiment CRYOHP (STS-53). Cryogenic two phase flight experiment CRYOTP (STS-62). Cryogenic flexible diode flight experiment CRYOFD

    Science.gov (United States)

    Thienel, Lee; Stouffer, Chuck

    1995-01-01

    This paper presents an overview of the Cryogenic Test Bed (CTB) experiments including experiment results, integration techniques used, and lessons learned during integration, test and flight phases of the Cryogenic Heat Pipe Flight Experiment (STS-53) and the Cryogenic Two Phase Flight Experiment (OAST-2, STS-62). We will also discuss the Cryogenic Flexible Diode Heat Pipe (CRYOFD) experiment which will fly in the 1996/97 time frame and the fourth flight of the CTB which will fly in the 1997/98 time frame. The two missions tested two oxygen axially grooved heat pipes, a nitrogen fibrous wick heat pipe and a 2-methylpentane phase change material thermal storage unit. Techniques were found for solving problems with vibration from the cryo-collers transmitted through the compressors and the cold heads, and mounting the heat pipe without introducing parasitic heat leaks. A thermally conductive interface material was selected that would meet the requirements and perform over the temperature range of 55 to 300 K. Problems are discussed with the bi-metallic thermostats used for heater circuit protection and the S-Glass suspension straps originally used to secure the BETSU PCM in the CRYOTP mission. Flight results will be compared to 1-g test results and differences will be discussed.

  14. Science Results from Colorado Student Space Weather Experiment (CSSWE): Energetic Particle Distribution in Near Earth Environment

    Science.gov (United States)

    Li, Xinlin

    2013-04-01

    The Colorado Student Space Weather Experiment (CSSWE) is a 3-unit (10cm x 10cm x 30cm) CubeSat mission funded by the National Science Foundation, launched into a low-Earth, polar orbit on 13 September 2012 as a secondary payload under NASA's Educational Launch of Nanosatellites (ELaNa) program. The science objectives of CSSWE are to investigate the relationship of the location, magnitude, and frequency of solar flares to the timing, duration, and energy spectrum of solar energetic particles reaching Earth, and to determine the precipitation loss and the evolution of the energy spectrum of trapped radiation belt electrons. CSSWE contains a single science payload, the Relativistic Electron and Proton Telescope integrated little experiment (REPTile), which is a miniaturization of the Relativistic Electron and Proton Telescope (REPT) built at the Laboratory for Atmospheric and Space Physics for NASA/Van Allen Probes mission, which consists of two identical spacecraft, launched 30 August 2012, that traverse the heart of the radiation belts in a low inclination orbit. CSSWE's REPTile is designed to measure the directional differential flux of protons ranging from 10 to 40 MeV and electrons from 0.5 to >3.3 MeV. The commissioning phase was completed and REPTile was activated on 4 October 2012. The data are very clean, far exceeding expectations! A number of engineering challenges had to be overcome to achieve such clean measurements under the mass and power limits of a CubeSat. The CSSWE is also an ideal class project, providing training for the next generation of engineers and scientists over the full life-cycle of a satellite project.

  15. The Atmospheric Neutral Density Experiment (ANDE) and Modulating Retroreflector in Space (MODRAS): Combined Flight Experiments for the Space Test Program

    National Research Council Canada - National Science Library

    Nicholas, A. C; Gilbreath, G. C; Thonnard, S. E; Kessel, R; Lucke, R; Sillman, C. P

    2003-01-01

    The Atmospheric Neutral Density Experiment (ANDE) is a low cost mission proposed by the Naval Research Laboratory to demonstrate a method to monitor the thermospheric neutral density at an altitude of 400 km...

  16. Feasibility study on longitudinal phase-space measurements at GSI UNILAC using charged-particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Milosic, Timo

    2014-04-14

    Accelerator facilities require access to many beam parameters during operation. The field of beam instrumentation serves this crucial role in commissioning, setup and optimisation of the facility. An important information is contained in the phase-space distribution of the accelerated particles. In case of GSI (Helmholtzzentrum fuer Schwerionenforschung) those are ions from protons to uranium. If established methods to access certain beam parameters do not exist, new approaches have to emerge. This is the case for the presented measurement setup which has been designed and realised by Forck et al. to support commissioning of the GSI high-current injector. It is aiming at an experimental method to access the longitudinal phase-space distribution at low energies of 1.4 AMeV. Established methods for higher energies and based on the measurement of the electric field distribution are not feasible at non-relativistic velocities. The presented method is based on a time-of-flight (TOF) measurement between two particle detectors. A modification allows, alternatively, the direct measurement of the kinetic energy using a mono-crystalline (MC) diamond detector. Currently, besides others, the focus of the optimisation of the injector is put on the longitudinal phase-space distribution. It allows for a systematic optimisation of the matching into the accelerator cavities and, thus, an improved transmission as well as lower emittance values. The new accelerator facility FAIR (Facility for Antiproton and Ion Research), a large-scale upgrade at GSI, requires an improved beam quality at the existing injector. In this work the experimental setup is investigated for its feasibility to measure the longitudinal phase-space distribution. To this end, the phase and momentum of the single ions along the beam axis have to be determined with high precision. Finally, the longitudinal phase-space distribution is identified with the measured ensemble. The setup is presented in detail

  17. Space Flight Effects on Antioxidant Molecules in Dry Tardigrades: The TARDIKISS Experiment

    Directory of Open Access Journals (Sweden)

    Angela Maria Rizzo

    2015-01-01

    Full Text Available The TARDIKISS (Tardigrades in Space experiment was part of the Biokon in Space (BIOKIS payload, a set of multidisciplinary experiments performed during the DAMA (Dark Matter mission organized by Italian Space Agency and Italian Air Force in 2011. This mission supported the execution of experiments in short duration (16 days taking the advantage of the microgravity environment on board of the Space Shuttle Endeavour (its last mission STS-134 docked to the International Space Station. TARDIKISS was composed of three sample sets: one flight sample and two ground control samples. These samples provided the biological material used to test as space stressors, including microgravity, affected animal survivability, life cycle, DNA integrity, and pathways of molecules working as antioxidants. In this paper we compared the molecular pathways of some antioxidant molecules, thiobarbituric acid reactive substances, and fatty acid composition between flight and control samples in two tardigrade species, namely, Paramacrobiotus richtersi and Ramazzottius oberhaeuseri. In both species, the activities of ROS scavenging enzymes, the total content of glutathione, and the fatty acids composition between flight and control samples showed few significant differences. TARDIKISS experiment, together with a previous space experiment (TARSE, further confirms that both desiccated and hydrated tardigrades represent useful animal tool for space research.

  18. Experiments on phase retrapping in φ Josephson junctions

    Energy Technology Data Exchange (ETDEWEB)

    Goldobin, Edward; Menditto, Rosina; Koelle, Dieter; Kleiner, Reinhold [University of Tuebingen, Tuebingen (Germany); Weides, Martin [KIT, Karlsruhe (Germany)

    2015-07-01

    We experimentally study retrapping of the phase in φ Josephson junctions (JJs) based on superconductor-insulator-ferromagnet-superconductor (SIFS) 0-π heterostructures. Such φ JJs have a doubly degenerate ground state (two potential energy wells) with the phases ±φ (0 < φ < π). We study in which of these two wells the phase is trapped upon return of the JJ to the zero voltage state. We find that for T>T* ∼ 2.4 K (large damping) the phase is always trapped in the +φ state. However, for lower T (small damping) the trapping result is a statistical mixture of the +φ and the -φ states due to the presence of noise in the system. The probability for retrapping to the -φ state increases and oscillates as T is decreasing below T*, reaching a saturation value of ∝ 30% for T

  19. Determining material parameters using phase-field simulations and experiments

    DEFF Research Database (Denmark)

    Zhang, Jin; Poulsen, Stefan O.; Gibbs, John W.

    2017-01-01

    as an initial condition in a phase-field simulation, the computed structure is compared to that measured experimentally at a later time. An optimization technique is used to find the material parameters that yield the best match of the simulated microstructure to the measured microstructure in a global manner...

  20. EMERGENCE OF A LYOTROPIC LAMELLAR PHASE - SURFACTANT-AQUEOUS PHASE CONTACT EXPERIMENTS EXAMINED WITH A CRYO-TRANSMISSION ELECTRON-MICROSCOPE : Surfactant-Aqueous Phase Contact Experiments Examined with a Cryo-Transmission Electron Microscope

    NARCIS (Netherlands)

    Sein, A; van Breemen, J.F.L.; Engberts, J.B.F.N.

    A phase penetration experiment has been conducted, employing a cryo-transmission electron microscope (cryo-TEM). With this technique, the phase transitions and the molecular rearrangement that result from the phase penetration can be studied on almost the molecular level. The technique has been

  1. Experimental measurement of the 4-d transverse phase space map of a heavy ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, H S

    1997-12-01

    The development and employment of a new diagnostic instrument for characterizing intense, heavy ion beams is reported on. This instrument, the ''Gated Beam Imager'' or ''GBI'' was designed for use on Lawrence Livermore National Laboratory Heavy Ion Fusion Project's ''Small Recirculator'', an integrated, scaled physics experiment and engineering development project for studying the transport and control of intense heavy ion beams as inertial fusion drivers in the production of electric power. The GBI allows rapid measurement and calculation of a heavy ion beam's characteristics to include all the first and second moments of the transverse phase space distribution, transverse emittance, envelope parameters and beam centroid. The GBI, with appropriate gating produces a time history of the beam resulting in a 4-D phase-space and time ''map'' of the beam. A unique capability of the GBI over existing diagnostic instruments is its ability to measure the ''cross'' moments between the two transverse orthogonal directions. Non-zero ''cross'' moments in the alternating gradient lattice of the Small Recirculator are indicative of focusing element rotational misalignments contributing to beam emittance growth. This emittance growth, while having the same effect on the ability to focus a beam as emittance growth caused by non-linear effects, is in principle removable by an appropriate number of focusing elements. The instrument uses the pepperpot method of introducing a plate with many pinholes into the beam and observing the images of the resulting beamlets as they interact with a detector after an appropriate drift distance. In order to produce adequate optical signal and repeatability, the detector was chosen to be a microchannel plate (MCP) with a phosphor readout screen. The heavy ions in the pepperpot beamlets are stopped in the MCP's thin

  2. Shared Space, Liminal Space: Five Years into a Community-University Place-Based Experiment

    Science.gov (United States)

    Barajas, Heidi Lasley; Martin, Lauren

    2016-01-01

    This article explores shared space at the University of Minnesota's Robert J. Jones Urban Research and Outreach Engagement Center (UROC), located four miles off campus in a community strong in assets, but facing inequality, disinvestment and racism. UROC's mission promotes university-community collaboration to solve critical urban challenges. We…

  3. An experiment to evaluate liquid hydrogen storage in space

    Science.gov (United States)

    Eberhardt, R. N.; Fester, D. A.; Johns, W. A.; Marino, J. S.

    1981-01-01

    The design and verification of a Cryogenic Fluid Management Experiment for orbital operation on the Shuttle is described. The experiment will furnish engineering data to establish design criteria for storage and supply of cryogenic fluids, mainly hydrogen, for use in low gravity environments. The apparatus comprises an LAD (liquid acquisition device) and a TVS (thermodynamic vent system). The hydrogen will be either vented or forced out by injected helium and the flow rates will be monitored. The data will be compared with ground-based simulations to determine optimal flow rates for the pressurizing gas and the release of the cryogenic fluid. It is noted that tests on a one-g, one-third size LAD system are under way.

  4. Fourth-Order Conservative Vlasov-Maxwell Solver for Cartesian and Cylindrical Phase Space Coordinates

    Science.gov (United States)

    Vogman, Genia

    Plasmas are made up of charged particles whose short-range and long-range interactions give rise to complex behavior that can be difficult to fully characterize experimentally. One of the most complete theoretical descriptions of a plasma is that of kinetic theory, which treats each particle species as a probability distribution function in a six-dimensional position-velocity phase space. Drawing on statistical mechanics, these distribution functions mathematically represent a system of interacting particles without tracking individual ions and electrons. The evolution of the distribution function(s) is governed by the Boltzmann equation coupled to Maxwell's equations, which together describe the dynamics of the plasma and the associated electromagnetic fields. When collisions can be neglected, the Boltzmann equation is reduced to the Vlasov equation. High-fidelity simulation of the rich physics in even a subset of the full six-dimensional phase space calls for low-noise high-accuracy numerical methods. To that end, this dissertation investigates a fourth-order finite-volume discretization of the Vlasov-Maxwell equation system, and addresses some of the fundamental challenges associated with applying these types of computationally intensive enhanced-accuracy numerical methods to phase space simulations. The governing equations of kinetic theory are described in detail, and their conservation-law weak form is derived for Cartesian and cylindrical phase space coordinates. This formulation is well known when it comes to Cartesian geometries, as it is used in finite-volume and finite-element discretizations to guarantee local conservation for numerical solutions. By contrast, the conservation-law weak form of the Vlasov equation in cylindrical phase space coordinates is largely unexplored, and to the author's knowledge has never previously been solved numerically. Thereby the methods described in this dissertation for simulating plasmas in cylindrical phase space

  5. APE: the Active Phasing Experiment to test new control system and phasing technology for a European Extremely Large Optical Telescope

    Science.gov (United States)

    Gonte, F.; Yaitskova, N.; Derie, F.; Constanza, A.; Brast, R.; Buzzoni, B.; Delabre, B.; Dierickx, P.; Dupuy, C.; Esteves, R.; Frank, C.; Guisard, S.; Karban, R.; Koenig, E.; Kolb, J.; Nylund, M.; Noethe, L.; Surdej, I.; Courteville, A.; Wilhelm, R.; Montoya, L.; Reyes, M.; Esposito, S.; Pinna, E.; Dohlen, K.; Ferrari, M.; Langlois, M.

    2005-08-01

    The future European Extremely Large Telescope will be composed of one or two giant segmented mirrors (up to 100 m of diameter) and of several large monolithic mirrors (up to 8 m in diameter). To limit the aberrations due to misalignments and defective surface quality it is necessary to have a proper active optics system. This active optics system must include a phasing system to limit the degradation of the PSF due to misphasing of the segmented mirrors. We will present the lastest design and development of the Active Phasing Experiment that will be tested in laboratory and on-sky connected to a VLT at Paranal in Chile. It includes an active segmented mirror, a static piston plate to simulate a secondary segmented mirror and of four phasing wavefront sensors to measure the piston, tip and tilt of the segments and the aberrations of the VLT. The four phasing sensors are the Diffraction Image Phase Sensing Instrument developed by Instituto de Astrofisica de Canarias, the Pyramid Phasing Sensor developed by Arcetri Astrophysical Observatory, the Shack-Hartmann Phasing Sensor developed by the European Southern Observatory and the Zernike Unit for Segment phasing developed by Laboratoire d'Astrophysique de Marseille. A reference measurement of the segmented mirror is made by an internal metrology developed by Fogale Nanotech. The control system of Active Phasing Experiment will perform the phasing of the segments, the guiding of the VLT and the active optics of the VLT. These activities are included in the Framework Programme 6 of the European Union.

  6. Synchronization in area-preserving maps: Effects of mixed phase space and coherent structures.

    Science.gov (United States)

    Mahata, Sasibhusan; Das, Swetamber; Gupte, Neelima

    2016-06-01

    The problem of synchronization of coupled Hamiltonian systems presents interesting features due to the mixed nature (regular and chaotic) of the phase space. We study these features by examining the synchronization of unidirectionally coupled area-preserving maps coupled by the Pecora-Caroll method. The master stability function approach is used to study the stability of the synchronous state and to identify the percentage of synchronizing initial conditions. The transient to synchronization shows intermittency with an associated power law. The mixed nature of the phase space of the studied map has notable effects on the synchronization times as is seen in the case of the standard map. Using finite-time Lyapunov exponent analysis, we show that the synchronization of the maps occurs in the neighborhood of invariant curves in the phase space. The phase differences of the coevolving trajectories show intermittency effects, due to the existence of stable periodic orbits contributing locally stable directions in the synchronizing neighborhoods. Furthermore, the value of the nonlinearity parameter, as well as the location of the initial conditions play an important role in the distribution of synchronization times. We examine drive response combinations which are chaotic-chaotic, chaotic-regular, regular-chaotic, and regular-regular. A range of scaling behavior is seen for these cases, including situations where the distributions show a power-law tail, indicating long synchronization times for at least some of the synchronizing trajectories. The introduction of coherent structures in the system changes the situation drastically. The distribution of synchronization times crosses over to exponential behavior, indicating shorter synchronization times, and the number of initial conditions which synchronize increases significantly, indicating an enhancement in the basin of synchronization. We discuss the implications of our results.

  7. Phase-space Analysis in the Group and Cluster Environment: Time Since Infall and Tidal Mass Loss

    Science.gov (United States)

    Rhee, Jinsu; Smith, Rory; Choi, Hoseung; Yi, Sukyoung K.; Jaffé, Yara; Candlish, Graeme; Sánchez-Jánssen, Ruben

    2017-07-01

    Using the latest cosmological hydrodynamic N-body simulations of groups and clusters, we study how location in phase-space coordinates at z = 0 can provide information on environmental effects acting in clusters. We confirm the results of previous authors showing that galaxies tend to follow a typical path in phase-space as they settle into the cluster potential. As such, different regions of phase-space can be associated with different times since first infalling into the cluster. However, in addition, we see a clear trend between total mass loss due to cluster tides and time since infall. Thus, we find location in phase-space provides information on both infall time and tidal mass loss. We find the predictive power of phase-space diagrams remains even when projected quantities are used (I.e., line of sight velocities, and projected distances from the cluster). We provide figures that can be directly compared with observed samples of cluster galaxies and we also provide the data used to make them as supplementary data to encourage the use of phase-space diagrams as a tool to understand cluster environmental effects. We find that our results depend very weakly on galaxy mass or host mass, so the predictions in our phase-space diagrams can be applied to groups or clusters alike, or to galaxy populations from dwarfs up to giants.

  8. Measurement of the Longitudinal Phase Space at the Photo Injector Test Facility at DESY in Zeuthen (PITZ)

    CERN Document Server

    Rönsch, J R; Richter, R; Hartrott, M V; Abrahamyan, K; Asova, G; Bähr, J; Dimitrov, G; Grabosch, H J; Han, J H; Khodyachykh, S; Krasilnikov, M; Liu, S; Lüdecke, H L; Miltchev, V; Oppelt, A; Petrosian, B; Riemann, S; Staykov, L; Stephan, F

    2005-01-01

    PITZ generates electron bunches of about 5 MeV. To optimize the RF-gun and to fulfill the requirements of the bunch compressor for an efficient compression the longitudinal phase space behind the gun has to be studied. A measurement of the longitudinal phase space comprises a correlated measurement of momentum and temporal distribution. The momentum distribution is measured by deflecting the electron bunch using a spectrometer magnet. A subsequent Cherenkov radiator (silica aerogel) * transforms the electron bunch into a light pulse with equal temporal and spatial distribution, which is imaged onto a streak camera by an optical transmission line ** to measure the longitudinal distribution. The longitudinal phase space was measured for different temporal laser distributions, charges and phases between RF field and laser. Physical effects in the dipole, optical transmission line and streak camera, which influence the longitudinal phase space measurements are taken into account. The measurement results were comp...

  9. Experiment TGV II—results of Phases I and II

    Science.gov (United States)

    Briançon, Ch.; Brudanin, V. B.; Čermák, P.; Egorov, V. G.; Klimenko, A. A.; Kovalík, A.; Mamedov, F.; Rukhadze, N. I.; Sandukovski, V. G.; Shitov, Yu. A.; Šimkovic, F.; Stekl, I.; Timkin, V. V.; Vylov, Ts.; Zinatulina, D. R.

    2009-11-01

    Currently, the TGV collaboration is investigating the two-neutrino double electron capture (2vEC/EC) of 106Cd at the Modane underground laboratory. The study is performed with low-background multi-HPGe detector TGV II, which has been constructed for measurements of the rare processes. The half-life limits of T1/2>2.6×1020 years (for Phase I, 8687 hours) and T1/2>3.6×1020 years (for Phase II, 9003 hours) were obtained for the ground state to ground state 2vEC/EC of 106Cd. The results already allow to rule out some of the previous nuclear structure calculations.

  10. Signal-to-Noise Ratio Prediction and Validation for Space Shuttle GPS Flight Experiment

    Science.gov (United States)

    Hwu, Shian U.; Adkins, Antha A.; Loh, Yin-Chung; Brown, Lisa C.; Sham, Catherine C.; Kroll, Quin D.

    2002-01-01

    A deterministic method for Space Station Global Positioning System (GPS) Signal-To- Noise Ratio (SNR) predictions is proposed. The complex electromagnetic interactions between GPS antennas and surrounding Space Station structures are taken into account by computational electromagnetic technique. This computer simulator is capable of taking into account multipath effects from dynamically changed solar panels and thermal radiators. A comparison with recent collected Space Station GPS system flight experiment data is presented. The simulation results are in close agreement with flight data.

  11. Cu–Ni nanoalloy phase diagram – Prediction and experiment

    OpenAIRE

    Sopoušek Jiří; Vřešťál Jan; Pinkas Jiří; Brož Pavel; Buršík Jiří; Stýskalík Aleš; Škoda David; Zobač Ondřej; Lee Joonho

    2014-01-01

    The Cu-Ni nanoalloy phase diagram respecting the nanoparticle size as an extra variable was calculated by the CALPHAD method. The samples of the Cu-Ni nanoalloys were prepared by the solvothermal synthesis from metal precursors. The samples were characterized by means of dynamic light scattering (DLS), infrared spectroscopy (IR), inductively coupled plasma optical emission spectroscopy (ICP/OES), transmission electron microscopy (TEM, HRTEM), and differential scanning calorimetry (DSC). The n...

  12. T-Rex: A Japanese Space Tether Experiment

    Science.gov (United States)

    Johnson, Les

    2009-01-01

    Electrodynamic tether (EDT) thrusters work by virtue of the force a magnetic field exerts on a wire carrying an electrical current. The force, which acts on any charged particle moving through a magnetic field (including the electrons moving in a current-carrying wire), were concisely expressed by Lorentz in 1895 in an equation that now bears his name. The force acts in a direction perpendicular to both the direction of current flow and the magnetic field vector. Electric motors make use of this force: a wire loop in a magnetic field is made to rotate by the torque the Lorentz Force exerts on it due to an alternating current in the loop times so as to keep the torque acting in the same sense. The motion of the loop is transmitted to a shaft, thus providing work. Although the working principle of EDT thrusters is not new, its application to space transportation may be significant. In essence, an EDT thruster is just a clever way of getting an electrical current to flow in a long orbiting wire (the tether) so that the Earth s magnetic field will accelerate the wire and, consequently the payload attached to the wire. The direction of current flow in the tether, either toward or away from the Earth along the local vertical, determines whether the magnetic force will raise or lower the orbit. The bias voltage of a vertically deployed metal tether, which results just from its orbital motion (assumed eastward) through Earth s magnetic field, is positive with respect to the ambient plasma at the top and negative at the bottom. This polarization is due to the action of the Lorentz force on the electrons in the tether. Thus, the natural current flow is the result of negative electrons being attracted to the upper end and then returned to the plasma at the lower end. The magnetic force in this case has a component opposite to the direction of motion, and thus leads to a lowering of the orbit and eventually to re-entry. In this generator mode of operation the Lorentz Force

  13. Development and Execution of Autonomous Procedures Onboard the International Space Station to Support the Next Phase of Human Space Exploration

    Science.gov (United States)

    Beisert, Susan; Rodriggs, Michael; Moreno, Francisco; Korth, David; Gibson, Stephen; Lee, Young H.; Eagles, Donald E.

    2013-01-01

    Now that major assembly of the International Space Station (ISS) is complete, NASA's focus has turned to using this high fidelity in-space research testbed to not only advance fundamental science research, but also demonstrate and mature technologies and develop operational concepts that will enable future human exploration missions beyond low Earth orbit. The ISS as a Testbed for Analog Research (ISTAR) project was established to reduce risks for manned missions to exploration destinations by utilizing ISS as a high fidelity micro-g laboratory to demonstrate technologies, operations concepts, and techniques associated with crew autonomous operations. One of these focus areas is the development and execution of ISS Testbed for Analog Research (ISTAR) autonomous flight crew procedures intended to increase crew autonomy that will be required for long duration human exploration missions. Due to increasing communications delays and reduced logistics resupply, autonomous procedures are expected to help reduce crew reliance on the ground flight control team, increase crew performance, and enable the crew to become more subject-matter experts on both the exploration space vehicle systems and the scientific investigation operations that will be conducted on a long duration human space exploration mission. These tests make use of previous or ongoing projects tested in ground analogs such as Research and Technology Studies (RATS) and NASA Extreme Environment Mission Operations (NEEMO). Since the latter half of 2012, selected non-critical ISS systems crew procedures have been used to develop techniques for building ISTAR autonomous procedures, and ISS flight crews have successfully executed them without flight controller involvement. Although the main focus has been preparing for exploration, the ISS has been a beneficiary of this synergistic effort and is considering modifying additional standard ISS procedures that may increase crew efficiency, reduce operational costs, and

  14. Special relativity effects for space-based coherent lidar experiments

    Science.gov (United States)

    Raogudimetla, V. S.

    1994-01-01

    There is a great need to develop a system that can measure accurately atmospheric wind profiles because an accurate data of wind profiles in the atmosphere constitutes single most input for reliable simulations of global climate numerical methods. Also such data helps us understand atmospheric circulation and climate dynamics better. Because of this need for accurate wind measurements, a space-based Laser Atmospheric Winds Sounder (LAWS) is being designed at MSFC to measure wind profiles in the lower atmosphere of the earth with an accuracy of 1 m/s at lower altitudes to 5m/s at higher altitudes. This system uses an orbiting spacecraft with a pulsed laser source and measures the Doppler shift between the transmitted and received frequencies to estimate the atmospheric wind velocities. If a significant return from the ground (sea) is possible, the spacecraft speed and height are estimated from it and these results and the Doppler shift are then used to estimate the wind velocities in the atmosphere. It is expected that at the proposed wavelengths, there will be enough backscatter from the aerosols but there may no be significant return from the ground. So a coherent (heterodyne) detection system is being proposed for signal processing because it can provide high signal to noise ratio and sensitivity and thus make the best use of low ground return. However, for a heterodyne detection scheme to provide the best results, it is important that the receiving aperture be aligned properly for the proposed wind sounder, this amounts to only a few microradians tolerance in alignment. It is suspected that the satellite motion relative to the ground may introduce errors in the order of a few microradians because of special relativity. Hence, the problem of laser scattering off a moving fixed target when the source and receiver are moving, which was not treated in the past in the literature, was analyzed in the following, using relativistic electrodynamics and applied to the

  15. Preliminary studies for the ORganics Exposure in Orbit (OREOcube) Experiment on the International Space Station

    NARCIS (Netherlands)

    Alonzo, Jason; Fresneau, A.; Elsaesser, A.; Chan, J.; Breitenbach, A.; Ehrenfreund, P.; Ricco, A.; Salama, F.; Mattioda, A.; Santos, O.; Cottin, H.; Dartois, E.; d'Hendecourt, L.; Demets, R.; Foing, B.; Martins, Z.; Sephton, M.; Spaans, M.; Quinn, R.

    Organic compounds that survive in uncommon space environments are animportant astrobiology focus. The ORganics Exposure in Orbit (OREOcube)experiment will investigate, in real time, chemical changes in organiccompounds exposed to low Earth orbit radiation conditions on anInternational Space Station

  16. 'Every space is claimed': smokers' experiences of tobacco denormalisation.

    Science.gov (United States)

    Bell, Kirsten; McCullough, Lucy; Salmon, Amy; Bell, Jennifer

    2010-09-01

    Over the past decade, the strategy of 'denormalising' tobacco use has become one of the cornerstones of the global tobacco control movement. Although tobacco denormalisation policies primarily affect people on the lowest rungs of the social ladder, few qualitative studies have explicitly set out to explore how smokers have experienced and responded to these legislative and social changes in attitudes towards tobacco use. Drawing on a qualitative study of interviews with 25 current and ex-smokers living in Vancouver, Canada, this paper examines the ways they interpret and respond to the new socio-political environment in which they must manage the increasingly problematised practice of tobacco smoking. Overall, while not opposed to smoking restrictions per se, study participants felt that recent legislation, particularly efforts to prohibit smoking in a variety of outdoor settings, was overly restrictive and that all public space had increasingly been 'claimed' by non-smokers. Also apparent from participants' accounts was the high degree of stigma attached to smoking. However, although the 'denormalisation' environment had encouraged several participants to quit smoking, the majority continued to smoke, raising ethical and practical questions about the value of denormalisation strategies as a way of reducing smoking-related mortality and morbidity. © 2010 The Authors. Journal compilation © 2010 Foundation for the Sociology of Health & Illness/Blackwell Publishing Ltd.

  17. Solving the inverse Ising problem by mean-field methods in a clustered phase space with many states.

    Science.gov (United States)

    Decelle, Aurélien; Ricci-Tersenghi, Federico

    2016-07-01

    In this work we explain how to properly use mean-field methods to solve the inverse Ising problem when the phase space is clustered, that is, many states are present. The clustering of the phase space can occur for many reasons, e.g., when a system undergoes a phase transition, but also when data are collected in different regimes (e.g., quiescent and spiking regimes in neural networks). Mean-field methods for the inverse Ising problem are typically used without taking into account the eventual clustered structure of the input configurations and may lead to very poor inference (e.g., in the low-temperature phase of the Curie-Weiss model). In this work we explain how to modify mean-field approaches when the phase space is clustered and we illustrate the effectiveness of our method on different clustered structures (low-temperature phases of Curie-Weiss and Hopfield models).

  18. Fatigue effect on phase transition of pedestrian movement: experiment and simulation study

    Science.gov (United States)

    Luo, Lin; Fu, Zhijian; Zhou, Xiaodong; Zhu, Kongjin; Yang, Hongtai; Yang, Lizhong

    2016-10-01

    How to model pedestrian movement is an intriguing problem in the area of statistical physics. As a common phenomenon of pedestrian movement, fatigue has a significant negative effect on pedestrian movement, especially when pedestrians move or run with heavy luggage, rescue the wounded in disaster, climb stairs and etc. According to the field observations and previous researches, fatigue coefficient is defined as the decrease of desired velocity in this study. However, previous researches lacked quantitative analysis of the effect of fatigue on pedestrian speed. It has been a great challenge to study the effect of fatigue on pedestrian flow, since pedestrians of heterogeneous walking abilities and the change of pedestrians’ moving properties need to be taken into consideration. Thus, at first, a series of pedestrian experiments, under three different conditions, were conducted to formulate the empirical relationship among fatigue, average free velocity, and walking distance. Then the empirical formulation of pedestrian fatigue was imported into the multi-velocity field floor cellular automata (FFCA) model for following pedestrian dynamics analysis. The velocity ratio was adjusted dynamically to adapt the change of pedestrians’ velocity due to fatigue. The fatigue, entrance flow rate and pedestrian’s initial desired velocity are found to have significant effects on the pedestrian flow. The space-time distributions of pedestrian density and velocity were explored in detail, with phase transition analyses from a free flow phase to a congestion phase. Additionally, the ‘density wave’ in the system can be observed if a certain ratio of burdened pedestrians lay in the high density region. The envelope of the ‘density wave’ reaches its maximum amplitude around the entrance position, and gradually diminishes away from the entrance.

  19. Detecting kinematic boundary surfaces in phase space: particle mass measurements in SUSY-like events

    Science.gov (United States)

    Debnath, Dipsikha; Gainer, James S.; Kilic, Can; Kim, Doojin; Matchev, Konstantin T.; Yang, Yuan-Pao

    2017-06-01

    We critically examine the classic endpoint method for particle mass determination, focusing on difficult corners of parameter space, where some of the measurements are not independent, while others are adversely affected by the experimental resolution. In such scenarios, mass differences can be measured relatively well, but the overall mass scale remains poorly constrained. Using the example of the standard SUSY decay chain \\tilde{q}\\to {\\tilde{χ}}_2^0\\to \\tilde{ℓ}\\to {\\tilde{χ}}_1^0 , we demonstrate that sensitivity to the remaining mass scale parameter can be recovered by measuring the two-dimensional kinematical boundary in the relevant three-dimensional phase space of invariant masses squared. We develop an algorithm for detecting this boundary, which uses the geometric properties of the Voronoi tessellation of the data, and in particular, the relative standard deviation (RSD) of the volumes of the neighbors for each Voronoi cell in the tessellation. We propose a new observable, \\overline{Σ} , which is the average RSD per unit area, calculated over the hypothesized boundary. We show that the location of the \\overline{Σ} maximum correlates very well with the true values of the new particle masses. Our approach represents the natural extension of the one-dimensional kinematic endpoint method to the relevant three dimensions of invariant mass phase space.

  20. James Webb Space Telescope Optical Simulation Testbed: Segmented Mirror Phase Retrieval Testing

    Science.gov (United States)

    Laginja, Iva; Egron, Sylvain; Brady, Greg; Soummer, Remi; Lajoie, Charles-Philippe; Bonnefois, Aurélie; Long, Joseph; Michau, Vincent; Choquet, Elodie; Ferrari, Marc; Leboulleux, Lucie; Mazoyer, Johan; N’Diaye, Mamadou; Perrin, Marshall; Petrone, Peter; Pueyo, Laurent; Sivaramakrishnan, Anand

    2018-01-01

    The James Webb Space Telescope (JWST) Optical Simulation Testbed (JOST) is a hardware simulator designed to produce JWST-like images. A model of the JWST three mirror anastigmat is realized with three lenses in form of a Cooke Triplet, which provides JWST-like optical quality over a field equivalent to a NIRCam module, and an Iris AO segmented mirror with hexagonal elements is standing in for the JWST segmented primary. This setup successfully produces images extremely similar to NIRCam images from cryotesting in terms of the PSF morphology and sampling relative to the diffraction limit.The testbed is used for staff training of the wavefront sensing and control (WFS&C) team and for independent analysis of WFS&C scenarios of the JWST. Algorithms like geometric phase retrieval (GPR) that may be used in flight and potential upgrades to JWST WFS&C will be explored. We report on the current status of the testbed after alignment, implementation of the segmented mirror, and testing of phase retrieval techniques.This optical bench complements other work at the Makidon laboratory at the Space Telescope Science Institute, including the investigation of coronagraphy for segmented aperture telescopes. Beyond JWST we intend to use JOST for WFS&C studies for future large segmented space telescopes such as LUVOIR.

  1. Non-singular Brans–Dicke collapse in deformed phase space

    Energy Technology Data Exchange (ETDEWEB)

    Rasouli, S.M.M., E-mail: mrasouli@ubi.pt [Departamento de Física, Universidade da Beira Interior, Rua Marquês d’Avila e Bolama, 6200 Covilhã (Portugal); Centro de Matemática e Aplicações (CMA - UBI), Universidade da Beira Interior, Rua Marquês d’Avila e Bolama, 6200 Covilhã (Portugal); Physics Group, Qazvin Branch, Islamic Azad University, Qazvin (Iran, Islamic Republic of); Ziaie, A.H., E-mail: ah_ziaie@sbu.ac.ir [Department of Physics, Shahid Beheshti University, G. C., Evin, 19839 Tehran (Iran, Islamic Republic of); Department of Physics, Shahid Bahonar University, PO Box 76175, Kerman (Iran, Islamic Republic of); Jalalzadeh, S., E-mail: shahram.jalalzadeh@unila.edu.br [Federal University of Latin-American Integration, Technological Park of Itaipu PO box 2123, Foz do Iguaçu-PR, 85867-670 (Brazil); Moniz, P.V., E-mail: pmoniz@ubi.pt [Departamento de Física, Universidade da Beira Interior, Rua Marquês d’Avila e Bolama, 6200 Covilhã (Portugal); Centro de Matemática e Aplicações (CMA - UBI), Universidade da Beira Interior, Rua Marquês d’Avila e Bolama, 6200 Covilhã (Portugal)

    2016-12-15

    We study the collapse process of a homogeneous perfect fluid (in FLRW background) with a barotropic equation of state in Brans–Dicke (BD) theory in the presence of phase space deformation effects. Such a deformation is introduced as a particular type of non-commutativity between phase space coordinates. For the commutative case, it has been shown in the literature (Scheel, 1995), that the dust collapse in BD theory leads to the formation of a spacetime singularity which is covered by an event horizon. In comparison to general relativity (GR), the authors concluded that the final state of black holes in BD theory is identical to the GR case but differs from GR during the dynamical evolution of the collapse process. However, the presence of non-commutative effects influences the dynamics of the collapse scenario and consequently a non-singular evolution is developed in the sense that a bounce emerges at a minimum radius, after which an expanding phase begins. Such a behavior is observed for positive values of the BD coupling parameter. For large positive values of the BD coupling parameter, when non-commutative effects are present, the dynamics of collapse process differs from the GR case. Finally, we show that for negative values of the BD coupling parameter, the singularity is replaced by an oscillatory bounce occurring at a finite time, with the frequency of oscillation and amplitude being damped at late times.

  2. Interference effects in phased beam tracing using exact half-space solutions.

    Science.gov (United States)

    Boucher, Matthew A; Pluymers, Bert; Desmet, Wim

    2016-12-01

    Geometrical acoustics provides a correct solution to the wave equation for rectangular rooms with rigid boundaries and is an accurate approximation at high frequencies with nearly hard walls. When interference effects are important, phased geometrical acoustics is employed in order to account for phase shifts due to propagation and reflection. Error increases, however, with more absorption, complex impedance values, grazing incidence, smaller volumes and lower frequencies. Replacing the plane wave reflection coefficient with a spherical one reduces the error but results in slower convergence. Frequency-dependent stopping criteria are then applied to avoid calculating higher order reflections for frequencies that have already converged. Exact half-space solutions are used to derive two additional spherical wave reflection coefficients: (i) the Sommerfeld integral, consisting of a plane wave decomposition of a point source and (ii) a line of image sources located at complex coordinates. Phased beam tracing using exact half-space solutions agrees well with the finite element method for rectangular rooms with absorbing boundaries, at low frequencies and for rooms with different aspect ratios. Results are accurate even for long source-to-receiver distances. Finally, the crossover frequency between the plane and spherical wave reflection coefficients is discussed.

  3. Erosion Results of the MISSE 8 Polymers Experiment After 2 Years of Space Exposure on the International Space Station

    Science.gov (United States)

    de Groh, Kim K.; Banks, Bruce A.; Asmar, Olivia C.; Yi, Grace T.; Mitchell, Gianna G.; Guo, Aobo; Sechkar, Edward A.

    2017-01-01

    Polymers and other oxidizable materials on the exterior of spacecraft in the low Earth orbit (LEO) space environment can be eroded due to reaction with atomic oxygen (AO). Therefore, in order to design durable spacecraft, it is important to know the LEO AO erosion yield (E(sub y), volume loss per incident oxygen atom) of materials susceptible to AO reaction. A spaceflight experiment, called the Polymers Experiment, which contained 42 samples, was developed to determine the effect of solar exposure on the AO E(sub y) of fluoropolymers flown in ram, wake, or zenith orientations. The Polymers Experiment was exposed to the LEO space environment on the exterior of the International Space Station (ISS) as part of the Materials International Space Station Experiment 8 (MISSE 8) mission. The MISSE 8 mission included samples flown in a zenith/nadir orientation for 2.14 years in the MISSE 8 Passive Experiment Container (PEC), and samples flown in a ram/wake orientation for 2.0 years in the Optical Reflector Materials Experiment-III (ORMatEIII) tray. The experiment included Kapton H (Registered Trademark) witness samples for AO fluence determination in each orientation. This paper provides an overview of the MISSE 8 mission, a description of the flight experiment with details on the polymers flown, the characterization techniques used, the AO fluence for each exposure orientation, and the LEO E(sub y) results. The E(sub y) of Teflon fluorinated ethylene propylene (FEP) samples flown in ram, wake, and zenith orientations have been compared, and the E(sub y) was found to be highly dependent on orientation and therefore environmental exposure. The FEP E(sub y) was found to directly correlate with the solar exposure/AO fluence ratio showing the effect of solar radiation and/or heating due to solar exposure on FEP erosion. In addition, back-surface carbon painted FEP (C-FEP) flown in the zenith orientation had a significantly higher E(sub y) than clear FEP or Al-FEP further

  4. Phase Equilibrium, Chemical Equilibrium, and a Test of the Third Law: Experiments for Physical Chemistry.

    Science.gov (United States)

    Dannhauser, Walter

    1980-01-01

    Described is an experiment designed to provide an experimental basis for a unifying point of view (utilizing theoretical framework and chemistry laboratory experiments) for physical chemistry students. Three experiments are described: phase equilibrium, chemical equilibrium, and a test of the third law of thermodynamics. (Author/DS)

  5. Experimental characterization of the transverse phase space of a 60-MeV electron beam through a compressor chicane

    Directory of Open Access Journals (Sweden)

    F. Zhou

    2006-11-01

    Full Text Available Space charge and coherent synchrotron radiation may deteriorate electron beam quality when the beam passes through a magnetic bunch compressor. This paper presents the transverse phase-space tomographic measurements for a compressed beam at 60 MeV, around which energy the first stage of magnetic bunch compression takes place in most advanced linacs. Transverse phase-space bifurcation of a compressed beam is observed at that energy, but the degree of the space charge-induced bifurcation is appreciably lower than the one observed at 12 MeV.

  6. Genelab: Scientific Partnerships and an Open-Access Database to Maximize Usage of Omics Data from Space Biology Experiments

    Science.gov (United States)

    Reinsch, S. S.; Galazka, J..; Berrios, D. C; Chakravarty, K.; Fogle, H.; Lai, S.; Bokyo, V.; Timucin, L. R.; Tran, P.; Skidmore, M.

    2016-01-01

    NASA's mission includes expanding our understanding of biological systems to improve life on Earth and to enable long-duration human exploration of space. The GeneLab Data System (GLDS) is NASA's premier open-access omics data platform for biological experiments. GLDS houses standards-compliant, high-throughput sequencing and other omics data from spaceflight-relevant experiments. The GeneLab project at NASA-Ames Research Center is developing the database, and also partnering with spaceflight projects through sharing or augmentation of experiment samples to expand omics analyses on precious spaceflight samples. The partnerships ensure that the maximum amount of data is garnered from spaceflight experiments and made publically available as rapidly as possible via the GLDS. GLDS Version 1.0, went online in April 2015. Software updates and new data releases occur at least quarterly. As of October 2016, the GLDS contains 80 datasets and has search and download capabilities. Version 2.0 is slated for release in September of 2017 and will have expanded, integrated search capabilities leveraging other public omics databases (NCBI GEO, PRIDE, MG-RAST). Future versions in this multi-phase project will provide a collaborative platform for omics data analysis. Data from experiments that explore the biological effects of the spaceflight environment on a wide variety of model organisms are housed in the GLDS including data from rodents, invertebrates, plants and microbes. Human datasets are currently limited to those with anonymized data (e.g., from cultured cell lines). GeneLab ensures prompt release and open access to high-throughput genomics, transcriptomics, proteomics, and metabolomics data from spaceflight and ground-based simulations of microgravity, radiation or other space environment factors. The data are meticulously curated to assure that accurate experimental and sample processing metadata are included with each data set. GLDS download volumes indicate strong

  7. Many-Body Quantum Spin Dynamics with Monte Carlo Trajectories on a Discrete Phase Space

    Directory of Open Access Journals (Sweden)

    J. Schachenmayer

    2015-02-01

    Full Text Available Interacting spin systems are of fundamental relevance in different areas of physics, as well as in quantum information science and biology. These spin models represent the simplest, yet not fully understood, manifestation of quantum many-body systems. An important outstanding problem is the efficient numerical computation of dynamics in large spin systems. Here, we propose a new semiclassical method to study many-body spin dynamics in generic spin lattice models. The method is based on a discrete Monte Carlo sampling in phase space in the framework of the so-called truncated Wigner approximation. Comparisons with analytical and numerically exact calculations demonstrate the power of the technique. They show that it correctly reproduces the dynamics of one- and two-point correlations and spin squeezing at short times, thus capturing entanglement. Our results open the possibility to study the quantum dynamics accessible to recent experiments in regimes where other numerical methods are inapplicable.

  8. Dust environment of an airless object: A phase space study with kinetic models

    Science.gov (United States)

    Kallio, E.; Dyadechkin, S.; Fatemi, S.; Holmström, M.; Futaana, Y.; Wurz, P.; Fernandes, V. A.; Álvarez, F.; Heilimo, J.; Jarvinen, R.; Schmidt, W.; Harri, A.-M.; Barabash, S.; Mäkelä, J.; Porjo, N.; Alho, M.

    2016-01-01

    The study of dust above the lunar surface is important for both science and technology. Dust particles are electrically charged due to impact of the solar radiation and the solar wind plasma and, therefore, they affect the plasma above the lunar surface. Dust is also a health hazard for crewed missions because micron and sub-micron sized dust particles can be toxic and harmful to the human body. Dust also causes malfunctions in mechanical devices and is therefore a risk for spacecraft and instruments on the lunar surface. Properties of dust particles above the lunar surface are not fully known. However, it can be stated that their large surface area to volume ratio due to their irregular shape, broken chemical bonds on the surface of each dust particle, together with the reduced lunar environment cause the dust particles to be chemically very reactive. One critical unknown factor is the electric field and the electric potential near the lunar surface. We have developed a modelling suite, Dusty Plasma Environments: near-surface characterisation and Modelling (DPEM), to study globally and locally dust environments of the Moon and other airless bodies. The DPEM model combines three independent kinetic models: (1) a 3D hybrid model, where ions are modelled as particles and electrons are modelled as a charged neutralising fluid, (2) a 2D electrostatic Particle-in-Cell (PIC) model where both ions and electrons are treated as particles, and (3) a 3D Monte Carlo (MC) model where dust particles are modelled as test particles. The three models are linked to each other unidirectionally; the hybrid model provides upstream plasma parameters to be used as boundary conditions for the PIC model which generates the surface potential for the MC model. We have used the DPEM model to study properties of dust particles injected from the surface of airless objects such as the Moon, the Martian moon Phobos and the asteroid RQ36. We have performed a (v0, m/q)-phase space study where the

  9. Lost in space: design of experiments and scientific exploration in a Hogarth Universe.

    Science.gov (United States)

    Lendrem, Dennis W; Lendrem, B Clare; Woods, David; Rowland-Jones, Ruth; Burke, Matthew; Chatfield, Marion; Isaacs, John D; Owen, Martin R

    2015-11-01

    A Hogarth, or 'wicked', universe is an irregular environment generating data to support erroneous beliefs. Here, we argue that development scientists often work in such a universe. We demonstrate that exploring these multidimensional spaces using small experiments guided by scientific intuition alone, gives rise to an illusion of validity and a misplaced confidence in that scientific intuition. By contrast, design of experiments (DOE) permits the efficient mapping of such complex, multidimensional spaces. We describe simulation tools that enable research scientists to explore these spaces in relative safety. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. The role of space communication in promoting national development with specific reference to experiments conducted in India

    Science.gov (United States)

    Chitnis, E. V.

    The paper describes the role of space communication in promoting national development with special reference to experiments conducted in India, namely SITE (1975-1976), STEP (1977-1979) and APPLE (1981 onwards). The impact of these experiments in economic, cultural and educational terms are discussed, pointing out social implications involved in using advance space communication technology for instruction and information in the areas of education, national integration and development. The paper covers special requirements which arise when a communication system covers backward and remote rural areas in a developing country. The impact on the population measured by conducting social surveys has been discussed - especially the gains of predominently illiterate new media - participants have been highlighted. Possibilities of improving skills of teachers, the quality of the primary and higher education have been covered. The preparation required both on ground as well as space to derive benefits of space technology are considered. A profile of INSAT which marks the culmination of the experimental phase and the beginning of operational domestic satellite system is sketched.

  11. Efficient methods for phase space analysis in spaceflight machanics: Application to the optimization of stable transfers

    Science.gov (United States)

    Nakhjiri, Navid

    This research presents algorithms for the numerical phase space analysis of large sets of trajectories. These involve propagating sections of phase space and studying the evolution of orbital characteristics which can be viewed as mapping dynamical properties of the system. Generating these maps is tedious and computationally expensive. This research proposes using an efficient numerical integration method based on a modified Picard integration for generating these maps. This numerical integration method is selected based on its potential use for developing parallel integration algorithms for massively parallel hardware such as Graphic Processing Units (GPUs). A requirement for the modified Picard integration is a method to transform vector fields to polynomial form in astrodynamics problems. This thesis demonstrates the transformation to polynomial form for simple and complex vector fields encountered in astrodynamics. This research also discusses the improvements of using this method for both parallel and sequential integrations. The integration method additionally provides the possibility to study nonlinear uncertainty propagations for a system by offering an efficient method to calculate high order state transition tensors. In the case of uncertainty propagation for large sets of trajectories, unscented transformation can be used to enhance the grid generation for maps. Besides the difficulties involved in generating maps, they are not immediately usable in practice. This research proposes the use of image processing and clustering analysis algorithms to autonomously detect and extract dynamical features from these maps. To do so, image segmentation algorithms such as k-mean clustering, contrast segmentation, and texture segmentation have been used. Additionally, this thesis discuses representing these sections of phase space using sets of B-spline and Gaussian mixtures. Based on data clustering, an enhanced map generation method is also introduced, which

  12. The phase-space structure of nearby dark matter as constrained by the SDSS

    Science.gov (United States)

    Leclercq, Florent; Jasche, Jens; Lavaux, Guilhem; Wandelt, Benjamin; Percival, Will

    2017-06-01

    Previous studies using numerical simulations have demonstrated that the shape of the cosmic web can be described by studying the Lagrangian displacement field. We extend these analyses, showing that it is now possible to perform a Lagrangian description of cosmic structure in the nearby Universe based on large-scale structure observations. Building upon recent Bayesian large-scale inference of initial conditions, we present a cosmographic analysis of the dark matter distribution and its evolution, referred to as the dark matter phase-space sheet, in the nearby universe as probed by the Sloan Digital Sky Survey main galaxy sample. We consider its stretchings and foldings using a tetrahedral tessellation of the Lagrangian lattice. The method provides extremely accurate estimates of nearby density and velocity fields, even in regions of low galaxy density. It also measures the number of matter streams, and the deformation and parity reversals of fluid elements, which were previously thought inaccessible using observations. We illustrate the approach by showing the phase-space structure of known objects of the nearby Universe such as the Sloan Great Wall, the Coma cluster and the Boötes void. We dissect cosmic structures into four distinct components (voids, sheets, filaments, and clusters), using the Lagrangian classifiers DIVA, ORIGAMI, and a new scheme which we introduce and call LICH. Because these classifiers use information other than the sheer local density, identified structures explicitly carry physical information about their formation history. Accessing the phase-space structure of dark matter in galaxy surveys opens the way for new confrontations of observational data and theoretical models. We have made our data products publicly available.

  13. Exploring links between foundation phase teachers’ content knowledge and their example spaces

    Directory of Open Access Journals (Sweden)

    Samantha Morrison

    2013-12-01

    Full Text Available This paper explores two foundation phase teachers’ example spaces (a space in the mind where examples exist when teaching number-related topics in relation to snapshots of their content knowledge (CK. Data was collected during a pilot primary maths for teaching course that included assessments of teacher content knowledge (CK. An analysis of a content-knowledge focused pre-test developed for the larger study indicated a relatively high score for one teacher and a low score for the other. Using Rowland’s (2008 framework, an analysis of classroom practice showed associations between a higher CK and the extent of a teacher’s example space and more coherent connections between different representational forms. Although no hard claims or generalisations of the link between teachers’ example spaces and their level of mathematics content knowledge can be made here, this study reinforces evidence of the need to increase teachers’ CK from a pedagogic perspective in order to raise the level of mathematics teaching and learning in the South African landscape.

  14. Space charge and beam stability issues of the Fermilab proton driver in Phase I

    Energy Technology Data Exchange (ETDEWEB)

    K. Y. Ng

    2001-08-24

    Issues concerning beam stability of the proposed Fermilab Proton Driver are studied in its Phase I. Although the betatron tune shifts are dominated by space charge, these shifts are less than 0.25 and will therefore not drive the symmetric and antisymmetric modes of the beam envelope into instability. The longitudinal space charge force is large and inductive inserts may be needed to compensate for the distortion of the rf potential. Although the longitudinal impedance is space charge dominated, it will not drive any microwave instability, unless the real part of the impedance coming from the inductive inserts and wall resistivity of the beam tube are large enough. The design of the beam tube is therefore very important in order to limit the flow of eddy current and keep wall resistivity low. The transverse impedance is also space charge dominated. With the Proton Driver operated at an imaginary transition gamma, however, Landau damping will never be canceled and beam stability can be maintained with negative chromaticities.

  15. Software Reliability Analysis of NASA Space Flight Software: A Practical Experience.

    Science.gov (United States)

    Sukhwani, Harish; Alonso, Javier; Trivedi, Kishor S; Mcginnis, Issac

    2016-01-01

    In this paper, we present the software reliability analysis of the flight software of a recently launched space mission. For our analysis, we use the defect reports collected during the flight software development. We find that this software was developed in multiple releases, each release spanning across all software life-cycle phases. We also find that the software releases were developed and tested for four different hardware platforms, spanning from off-the-shelf or emulation hardware to actual flight hardware. For releases that exhibit reliability growth or decay, we fit Software Reliability Growth Models (SRGM); otherwise we fit a distribution function. We find that most releases exhibit reliability growth, with Log-Logistic (NHPP) and S-Shaped (NHPP) as the best-fit SRGMs. For the releases that experience reliability decay, we investigate the causes for the same. We find that such releases were the first software releases to be tested on a new hardware platform, and hence they encountered major hardware integration issues. Also such releases seem to have been developed under time pressure in order to start testing on the new hardware platform sooner. Such releases exhibit poor reliability growth, and hence exhibit high predicted failure rate. Other problems include hardware specification changes and delivery delays from vendors. Thus, our analysis provides critical insights and inputs to the management to improve the software development process. As NASA has moved towards a product line engineering for its flight software development, software for future space missions will be developed in a similar manner and hence the analysis results for this mission can be considered as a baseline for future flight software missions.

  16. Phase-locking to a free-space terahertz comb for metrological-grade terahertz lasers.

    Science.gov (United States)

    Consolino, L; Taschin, A; Bartolini, P; Bartalini, S; Cancio, P; Tredicucci, A; Beere, H E; Ritchie, D A; Torre, R; Vitiello, M S; De Natale, P

    2012-01-01

    Optical frequency comb synthesizers have represented a revolutionary approach to frequency metrology, providing a grid of frequency references for any laser emitting within their spectral coverage. Extending the metrological features of optical frequency comb synthesizers to the terahertz domain would be a major breakthrough, due to the widespread range of accessible strategic applications and the availability of stable, high-power and widely tunable sources such as quantum cascade lasers. Here we demonstrate phase-locking of a 2.5 THz quantum cascade laser to a free-space comb, generated in a LiNbO(3) waveguide and covering the 0.1-6 THz frequency range. We show that even a small fraction (laser is sufficient to generate a beat note suitable for phase-locking to the comb, paving the way to novel metrological-grade terahertz applications, including high-resolution spectroscopy, manipulation of cold molecules, astronomy and telecommunications.

  17. Phase space dependence of the correlations among particles produced in high energy nuclear collisions

    Energy Technology Data Exchange (ETDEWEB)

    Dabrowska, A. [Henryk Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland); Freier, P.S. [Minnesota Univ., Minneapolis, MN (United States). School of Physics and Astronomy; Holynski, R. [Henryk Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland); Jones, W.V. [Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Physics and Astronomy; Jurak, A. [Henryk Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland); Kudzia, D. [Henryk Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland); Olszewski, A. [Henryk Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland); Szarska, M. [Henryk Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland); Trzupek, A. [Henryk Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland); Waddington, C.J. [Minnesota Univ., Minneapolis, MN (United States). School of Physics and Astronomy; Wefel, J.P. [Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Physics and Astronomy; Wilczynska, B. [Henryk Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland); Wilczynski, H. [Henryk Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland); Wolter, W. [Henryk Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland); Wosiek, B. [Henryk Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland); Wozniak, K. [Henryk Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland)

    1995-08-01

    The fluctuations of produced particles are investigated in central collisions of proton, oxygen and sulphur projectiles with (Ag,Br) target nuclei at 200 GeV per nucleon. The analysis is carried out in terms of factorial moments and correlation integrals in different pseudorapidity regions. Evidence is found for nonstatistical fluctuations. These fluctuations depend weakly on the phase space, although a slightly stronger effect is seen in the forward pseudorapidity region. The dependence of the observed effect on the mass of the projectile particle disagrees with the expectations of super-position models. The results of this analysis indicate that a self-similar cascade process is the origin of the fluctuations, even though the association of the observed effect with the occurrence of a second order phase transition cannot be definitely ruled out. (orig.)

  18. The Impact of Early Design Phase Risk Identification Biases on Space System Project Performance

    Science.gov (United States)

    Reeves, John D., Jr.; Eveleigh, Tim; Holzer, Thomas; Sarkani, Shahryar

    2012-01-01

    Risk identification during the early design phases of complex systems is commonly implemented but often fails to result in the identification of events and circumstances that truly challenge project performance. Inefficiencies in cost and schedule estimation are usually held accountable for cost and schedule overruns, but the true root cause is often the realization of programmatic risks. A deeper understanding of frequent risk identification trends and biases pervasive during space system design and development is needed, for it would lead to improved execution of existing identification processes and methods.

  19. Interpretation of bent-crystal rocking curves using phase-space diagrams

    CERN Document Server

    Ren, B; Chapman, L D; Wu, X Y; Zhong, Z; Ivanov, I; Huang, X

    2000-01-01

    In developing a double bent-Laue crystal monochromator for synchrotron-based monochromatic computed tomography system, we applied a special projection of the phase-space diagram to interpret the shape of bent crystal rocking curves. Unlike the rigorous approach of the ray-tracing method, this graphical method provides direct pictures that allow checks of the physical significance of the shapes of the rocking curves, thereby providing quick guidelines for matching two bent crystals. The method's usefulness is demonstrated with our crexperimental results, and its limitations are discussed.

  20. Superradiant emission from a cascade atomic ensemble by positive-P phase space method simulation

    Science.gov (United States)

    Jen, Hsiang-Hua

    2012-06-01

    We numerically simulate the superradiant emission properties from an atomic ensemble with cascade level configuration. The correlated spontaneous emissions (signal then idler fields) are initiated by quantum fluctuations of the ensemble. We apply the positive-P phase space method to investigate the dynamics of the atoms and counter-propagating emissions in the four-wave mixing condition. The light field intensities are calculated, and the signal-idler correlation function is studied for different optical depths of the atomic ensemble. Shorter correlation time scale for a denser atomic ensemble implies a broader spectral window required to store or retrieve the idler pulse.

  1. New features of electron phase space holes observed by the THEMIS mission.

    Science.gov (United States)

    Andersson, L; Ergun, R E; Tao, J; Roux, A; Lecontel, O; Angelopoulos, V; Bonnell, J; McFadden, J P; Larson, D E; Eriksson, S; Johansson, T; Cully, C M; Newman, D L; Newman, D N; Goldman, M V; Glassmeier, K-H; Baumjohann, W

    2009-06-05

    Observations of electron phase-space holes (EHs) in Earth's plasma sheet by the THEMIS satellites include the first detection of a magnetic perturbation (deltaB_{ parallel}) parallel to the ambient magnetic field (B0). EHs with a detectable deltaB_{ parallel} have several distinguishing features including large electric field amplitudes, a magnetic perturbation perpendicular to B0, high speeds ( approximately 0.3c) along B0, and sizes along B0 of tens of Debye lengths. These EHs have a significant center potential (Phi approximately k_{B}T_{e}/e), suggesting strongly nonlinear behavior nearby such as double layers or magnetic reconnection.

  2. Particle Control in Phase Space by Global K-Means Clustering

    DEFF Research Database (Denmark)

    Frederiksen, Jacob Trier; Lapenta, G.; Pessah, M. E.

    2015-01-01

    decreasing or increasing the entire particle population, based on k-means clustering of the data. In essence the procedure amounts to merging or splitting particles by statistical means, throughout the entire simulation volume in question, while minimizing a 6-dimensional total distance measure to preserve...... --- \\emph{i.e.}, Nf≲0.33Ni. Interestingly, we find that an accurate particle splitting step can be performed using k-means as well; this from an argument of symmetry. The split solution, using k-means, places splitted particles optimally, to obtain maximal spanning on the phase space manifold...

  3. Hubble Space Telescope cycle 5. Phase 1: Proposal instructions, version 4.0

    Science.gov (United States)

    Madau, Piero (Editor)

    1994-01-01

    This document has the following purposes: it describes the information that must be submitted to the Space Telescope Science Institute by Phase 1 proposers, both electronically and on paper, and describes how to submit it; it describes how to fill out the proposal LATEX templates; it describes how to estimate the number of spacecraft orbits that the proposed observations will require; it provides detailed information about the parameters that are used in the forms to describe the requested observations; and it provides information about the preparation and electronic submission of proposal files. Examples of completed proposal forms are included.

  4. A novel approach for the diagnosis of ventricular tachycardia based on phase space reconstruction of ECG

    CERN Document Server

    Koulaouzidis, George; Cappiello, Grazia; Mazomenos, Evangelos B; Maharatna, Koushik; Morgan, John

    2014-01-01

    Ventricular arrhythmias comprise a group of disorders which manifest clinically in a variety of ways from ventricular premature beats (VPB) and no sustained ventricular tachycardia (in healthy subjects) to sudden cardiac death due to ventricular tachyarrhythmia in patients with and/or without structural heart disease. Ventricular fibrillation (VF) and ventricular tachycardia (VT) are the most common electrical mechanisms for cardiac arrest. Accurate and automatic recognition of these arrhythmias from electrocardiography (ECG) is a crucial task for medical professionals. The purpose of this research is to develop a new index for the differential diagnosis of normal sinus rhythm (SR) and ventricular arrhythmias, based on phase space reconstruction (PSR).

  5. Solid Phase Characterization of Tank 241-AY-102 Annulus Space Particulate

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, G. A.

    2013-01-30

    The Special Analytical Studies Group at the 222-S Laboratory (222-S) examined the particulate recovered from a series of samples from the annular space of tank 241-AY-102 (AY-102) using solid phase characterization (SPC) methods. These include scanning electron microscopy (SEM) using the ASPEX®1 scanning electron microscope, X-ray diffraction (XRD) using the Rigaku®2 MiniFlex X-ray diffractometer, and polarized light microscopy (PLM) using the Nikon®3 Eclipse Pol optical microscope. The SEM is equipped with an energy dispersive X-ray spectrometer (EDS) to provide chemical information.

  6. Simulations of Ground and Space-Based Oxygen Atom Experiments

    Science.gov (United States)

    Minton, T. K.; Cline, J. A.; Braunstein, M.

    2002-01-01

    obtained from separate measurements. These computations use basic engineering models for the gas-gas and gas-surface scattering and focus on the influence of multi-collision effects. These simulations characterize many important quantities of interest including the actual flux of atoms that reach the surface, the energy distribution of this flux, as well as the direction of the velocity of the flux that strikes the surface. These quantities are important in characterizing the conditions which give rise to measured surface erosion. The calculations also yield time- snapshots of the pulse as it impacts and flows around the surface. These snapshots reveal the local environment of gas near the surface for the duration of the pulse. We are also able to compute the flux of molecules that travel downstream and reach the spectrometer, and we characterize their velocity distribution. The number of atoms that reach the spectrometer can in fact be influenced by the presence of the surface due to gas-gas collisions from atoms scattered h m the surface, and it will generally be less than that with the surface absent. This amounts to an overall normalization factor in computing erosion yields. We discuss these quantities and their relationship to the gas-surf$ce interaction parameters. We have also performed similar calculations corresponding to conditions (number densities, temperatures, and velocities) of low-earth orbit. The steady-state nature and lower overall flux of the actual space environment give rise to differences in the nature of the gas-impacts on the surface from those of the ground-based measurements using a pulsed source.

  7. Solar photovoltaic/thermal residential experiment. Phase I. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Darkazalli, G.

    1980-07-01

    Month-by-month energy transfer data between an occupied residence and its energy supply systems are presented. The data were obtained during the first phase of photovoltaic/thermal residential research conducted at the University of Texas at Arlington/Solar Energy Research Facility. This research was part of the US Department of Energy Photovoltaic/Thermal Project managed by the M.I.T. Lincoln Laboratory. Energy transfer data are divided into different categories depending on how the energy is consumed. Energy transfers between some system components are also categorized. These components include a flat-plate thermal collector array, a flat-plate photovoltaic array, a dc-to-ac inverter, thermal storage tanks, and a series heat pump. System operations included directing surplus electrical energy (generated by the photovoltaic array) into the local utility grid. The heat pump used off-peak utility power to chill water during the cooling season.

  8. Gas-phase experiments on Au(III) photochemistry.

    Science.gov (United States)

    Marcum, Jesse C; Kaufman, Sydney H; Weber, J Mathias

    2011-04-14

    Irradiation of AuCl(4)(-) and AuCl(2)(OH)(2)(-) in the gas-phase using ultraviolet light (220-415 nm) leads to their dissociation. Observed fragment ions for AuCl(4)(-) are AuCl(3)(-) and AuCl(2)(-) and for AuCl(2)(OH)(2)(-) are AuCl(2)(-) and AuClOH(-). All fragment channels correspond to photoreduction of the gold atom to either Au(II) or Au(I) depending on the number of neutral ligands lost. Fragment branching ratios of AuCl(4)(-) are observed to be highly energy dependent and can be explained by comparison of the experimental data to calculated threshold energies obtained using density functional theory. The main observed spectral features are attributed to ligand-to-metal charge transfer transitions. These results are discussed in the context of the molecular-level mechanisms of Au(III) photochemistry.

  9. Aesthetic and Affective Experiences in Coffee Shops: A Deweyan Engagement with Ordinary Affects in Ordinary Spaces

    Science.gov (United States)

    Nautiyal, Jaishikha

    2016-01-01

    Can everyday spaces, such as coffee shops bustling with rapid activity, promise an aesthetic experience that remains untapped and undertheorized? If so, what kinds of communicative habits make the coffee shop experience aesthetically wholesome? To this end, I engage and extend American pragmatist John Dewey's mission of recovering aesthetic…

  10. Culturing immobilized plant cells for the TUBUL space experiments on the DELTA and 12S Missions

    NARCIS (Netherlands)

    Sieberer, B.; Emons, A.M.C.; Vos, J.W.

    2007-01-01

    Abstract For the TUBUL experiments during the DELTA mission in April 2004 and 12S mission in March/April 2006 on board the Soyuz capsule and the International Space Station we developed a method to culture and chemically fix plant suspension culture cells. The aim of the ten day experiment was to

  11. Erosion Results of the MISSE 7 Polymers Experiment and Zenith Polymers Experiment After 1.5 Years of Space Exposure

    Science.gov (United States)

    De Groh, Kim K.; Banks, Bruce A.; Yi, Grace T.; Haloua, Athena; Imka, Emily C.; Mitchell, Gianna G.; Asmar, Olivia C.; Leneghan, Halle A.; Sechkar, Edward A.

    2016-01-01

    Polymers and other oxidizable materials on the exterior of spacecraft in the low Earth orbit (LEO) space environment can be eroded due to reaction with atomic oxygen (AO). Therefore, in order to design durable spacecraft it is important to know the LEO AO erosion yield (E(sub y), volume loss per incident oxygen atom) of materials susceptible to AO reaction. Two spaceflight experiments, the Polymers Experiment and the Zenith Polymers Experiment, were developed to determine the AO E(sub y) of various polymers flown in ram, wake or zenith orientations in LEO. These experiments were flown as part of the Materials International Space Station Experiment 7 (MISSE 7) mission for 1.5 years on the exterior of the International Space Station (ISS). The experiments included Kapton H(TradeMark) witness samples for AO fluence determination in ram and zenith orientations. The Polymers Experiment also included samples to determine whether AO erosion of high and low ash containing polymers is dependent on fluence. This paper provides an overview of the MISSE 7 mission, a description of the flight experiments with details on the polymers flown, the characterization techniques used, the AO fluence for each exposure orientation, and the LEO E(sub y) results. The E(sub y) values ranged from 7.99x10(exp -28)cu cm/atom for TiO2/Al2O3 coated Teflon(TradeMark) fluorinated ethylene propylene (FEP) flown in the ram orientation to 1.22x10(exp -23cu cm/atom for polyvinyl alcohol (PVOH) flown in the zenith orientation. The E(sub y) of similar samples flown in different orientations has been compared to help determine solar exposure and associated heating effects on AO erosion. The E(sub y) data from these ISS spaceflight experiments provides valuable information for LEO spacecraft design purposes.

  12. Benchmark enclosure fire suppression experiments - phase 1 test report.

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa, Victor G.; Nichols, Robert Thomas; Blanchat, Thomas K.

    2007-06-01

    A series of fire benchmark water suppression tests were performed that may provide guidance for dispersal systems for the protection of high value assets. The test results provide boundary and temporal data necessary for water spray suppression model development and validation. A review of fire suppression in presented for both gaseous suppression and water mist fire suppression. The experimental setup and procedure for gathering water suppression performance data are shown. Characteristics of the nozzles used in the testing are presented. Results of the experiments are discussed.

  13. Pleiades Experiments on the NIF: Phase II-C

    Energy Technology Data Exchange (ETDEWEB)

    Benstead, James [Atomic Weapons Establishment (AWE), Berkshire (United Kingdom); Morton, John [Atomic Weapons Establishment (AWE), Berkshire (United Kingdom); Guymer, Thomas [Atomic Weapons Establishment (AWE), Berkshire (United Kingdom); Garbett, Warren [Atomic Weapons Establishment (AWE), Berkshire (United Kingdom); Stevenson, Mark [Atomic Weapons Establishment (AWE), Berkshire (United Kingdom); Moore, Alastair [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kline, John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Schmidt, Derek [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Perry, Ted [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lanier, Nick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Workman, Jonathan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-08

    Pleiades was a radiation transport campaign fielded at the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) between 2011 and 2014. The primary goals of the campaign were to develop and characterise a reproducible ~350eV x-ray drive and to constrain a number of material data properties required to successfully model the propagation of radiation through two low-density foam materials. A further goal involved the development and qualification of diagnostics for future radiation transport experiments at NIF. Pleiades was a collaborative campaign involving teams from both AWE and the Los Alamos National Laboratory (LANL).

  14. Two-color experiments in the gas phase at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, M., E-mail: michael.meyer@u-psud.f [LIXAM/CNRS, UMR 8624, Centre Universitaire Paris-Sud, Batiment 350, F-91405 Orsay Cedex (France); Cubaynes, D. [LIXAM/CNRS, UMR 8624, Centre Universitaire Paris-Sud, Batiment 350, F-91405 Orsay Cedex (France); Dardis, J.; Hayden, P.; Hough, P.; Richardson, V.; Kennedy, E.T.; Costello, J.T. [School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9 (Ireland); Duesterer, S.; Li, W.B.; Radcliffe, P.; Redlin, H.; Feldhaus, J. [DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Strakhova, S.I.; Gryzlova, E.V.; Grum-Grzhimailo, A.N. [Institute of Nuclear Physics, Moscow State University, Moscow 119991 (Russian Federation); Taieb, R.; Maquet, A. [UPMC, Universite Paris 06, CNRS, UMR 7614, LCPMR, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France)

    2010-08-15

    Intense ultra-short XUV-pulses from the Free Electron Laser in Hamburg (FLASH) were used in combination with the synchronized near-infrared (NIR) radiation from a femtosecond laser to perform two-color experiments on rare gas atoms and small molecules. Results of atomic photoionization in the presence of a NIR dressing field are presented and discussed for the low field regime, i.e. for intensities of less than 10{sup 11} W/cm{sup 2}. In particular, the analysis of two-color Above Threshold Ionization (ATI) as a function of the relative orientation of the polarization vectors of both photon beams provided detailed information about the partial photoionization crosssections by comparing the experimental results with theoretical values obtained by employing second-order perturbation theory and the 'soft-photon' approximation. Furthermore, a first time-resolved study was performed on the photodissociation of molecular hydrogen. In this proof-of-principle experiment, the excited atomic fragments, produced in the primary interaction with the intense XUV pulse, are probed by a time delayed NIR laser pulse that ionizes these fragments.

  15. Manifestation of the geometric phase in neutron spin-echo experiments

    NARCIS (Netherlands)

    Kraan, W.H.; Grigoriev, S.V.; Rekveldt, M.T.

    2010-01-01

    We show how the geometric (Berry’s) phase becomes manifest on adiabatic rotation of the polarization vector in the magnetic field configuration in the arms in a neutron spin echo (NSE) experiment.When the neutron beam used is monochromatic, a geometric phase collected in one spin-echo arm can be

  16. Conducting Science with a CubeSat: The Colorado Student Space Weather Experiment (CSSWE)

    Science.gov (United States)

    Palo, Scott; Li, Xinlin; Gerhardt, David; Blum, Lauren; Schiller, Quintin; Kohnert, Rick

    2014-06-01

    The Colorado Student Space Weather Experiment is a 3-unit (10cm x 10cm x 30cm) CubeSat funded by the National Science Foundation and constructed at the University of Colorado (CU). The CSSWE science instrument, the Relativistic Electron and Proton Telescope integrated little experiment (REPTile), provides directional differential flux measurements of 0.5 to >3.3 MeV electrons and 9 to 40 MeV protons. Though a collaboration of 60+ multidisciplinary graduate and undergraduate students working with professors and professional engineers, CSSWE was designed, built, tested, and delivered in 3 years. On September 13, 2012, CSSWE was inserted to a 477 x 780 km, 65° orbit as a secondary payload on an Atlas V through the NASA Educational Launch of Nanosatellites (ELaNa) program.The first successful contact with CSSWE was made within a few hours of launch. CSSWE then completed a 20 day system commissioning phase which validated the performance of the communications, power, and attitude control systems. This was immediately followed by an accelerated 24 hour REPTile commissioning period in time for a geomagnetic storm. The high quality, low noise science data return from REPTile is complementary to the NASA Van Allen Probes mission, which launched two weeks prior to CSSWE. On January 5, 2013, CSSWE completed 90 days of on-orbit science operations, achieving the baseline goal for full mission success and has been operating since. An overview of the CSSWE system, on-orbit performance and lessons learned will be presented.

  17. Objective techniques for psychological assessment, phase 2. [techniques for measuring human performance during space flight stress

    Science.gov (United States)

    Wortz, E. C.; Saur, A. J.; Nowlis, D. P.; Kendall, M. P.

    1974-01-01

    Results are presented of an initial experiment in a research program designed to develop objective techniques for psychological assessment of individuals and groups participating in long-duration space flights. Specifically examined is the rationale for utilizing measures of attention as an objective assessment technique. Subjects participating in the experiment performed various tasks (eg, playing matrix games which appeared on a display screen along with auditory stimuli). The psychophysiological reactions of the subjects were measured and are given. Previous research of various performance and psychophysiological methods of measuring attention is also discussed. The experiment design (independent and dependent variables) and apparatus (computers and display devices) are described and shown. Conclusions and recommendations are presented.

  18. General phase spaces: from discrete variables to rotor and continuum limits

    Science.gov (United States)

    Albert, Victor V.; Pascazio, Saverio; Devoret, Michel H.

    2017-12-01

    We provide a basic introduction to discrete-variable, rotor, and continuous-variable quantum phase spaces, explaining how the latter two can be understood as limiting cases of the first. We extend the limit-taking procedures used to travel between phase spaces to a general class of Hamiltonians (including many local stabilizer codes) and provide six examples: the Harper equation, the Baxter parafermionic spin chain, the Rabi model, the Kitaev toric code, the Haah cubic code (which we generalize to qudits), and the Kitaev honeycomb model. We obtain continuous-variable generalizations of all models, some of which are novel. The Baxter model is mapped to a chain of coupled oscillators and the Rabi model to the optomechanical radiation pressure Hamiltonian. The procedures also yield rotor versions of all models, five of which are novel many-body extensions of the almost Mathieu equation. The toric and cubic codes are mapped to lattice models of rotors, with the toric code case related to U(1) lattice gauge theory.

  19. Exploring the data constrained phase space of the last Antarctic glacial cycle

    Science.gov (United States)

    Lecavalier, Benoit; Tarasov, Lev

    2017-04-01

    The evolution of the Antarctic Ice Sheet over the last two glacial cycles is studied using the Glacial Systems Model (GSM). Glaciological modelling is an effective tool to generate continental-scale reconstructions over glacial cycles, but the models depend on parameterizations to account for the deficiencies (e.g., missing physics, unresolved sub-grid processes, uncertain boundary conditions) inherent in any numerical model. These parameters, considered together, form a parameter phase space from which sets of parameters can be sampled; each set corresponds to an ice sheet reconstruction. The GSM has been updated with a number of recent developments: hybrid SIA-SSA physics, Schoof grounding line parameterization, broadened degrees of freedom in the climate forcing, sub-shelf melt explicitly dependent on ocean temperatures, improved hydrofracturing, cliff failure at the margins, basal topographic uncertainties, impact of basal drag roughness and subgrid statistics, and first order geoidal corrections in the coupled glacial isostatic adjustment component. Parametric uncertainties are defined in the GSM using >36 ensemble parameters. Prior to conducting a full Bayesian calibration, one must first validate the ability of the GSM to simulate a broad range of responses. We attempt this by latin hypercube sampling of the parameter phase space and comparing the model predictions against our constraint database consisting of past elevation, extent and relative sea level observations and the present day geometry. We document the capability of the GSM to envelope the observational constraints given the parametric uncertainties and discuss the implications for the evolution of the Antarctic Ice Sheet.

  20. Transverse phase space mapping of relativistic electron beams using optical transition radiation

    Directory of Open Access Journals (Sweden)

    G. P. Le Sage

    1999-12-01

    Full Text Available Optical transition radiation (OTR has proven to be a versatile and effective diagnostic for measuring the profile, divergence, and emittance of relativistic electron beams with a wide range of parameters. Diagnosis of the divergence of modern high brightness beams is especially well suited to OTR interference (OTRI techniques, where multiple dielectric or metal foils are used to generate a spatially coherent interference pattern. Theoretical analysis of measured OTR and OTRI patterns allows precise measurement of electron beam emittance characteristics. Here we describe an extension of this technique to allow mapping of divergence characteristics as a function of transverse coordinates within a measured beam. We present the first experimental analysis of the transverse phase space of an electron beam using all optical techniques. Comparing an optically masked portion of the beam to the entire beam, we measure different angular spread and average direction of the particles. Direct measurement of the phase-space ellipse tilt angle has been demonstrated using this optical masking technique.

  1. Dynamic analysis of heartbeat rate signals of epileptics using multidimensional phase space reconstruction approach

    Science.gov (United States)

    Su, Zhi-Yuan; Wu, Tzuyin; Yang, Po-Hua; Wang, Yeng-Tseng

    2008-04-01

    The heartbeat rate signal provides an invaluable means of assessing the sympathetic-parasympathetic balance of the human autonomic nervous system and thus represents an ideal diagnostic mechanism for detecting a variety of disorders such as epilepsy, cardiac disease and so forth. The current study analyses the dynamics of the heartbeat rate signal of known epilepsy sufferers in order to obtain a detailed understanding of the heart rate pattern during a seizure event. In the proposed approach, the ECG signals are converted into heartbeat rate signals and the embedology theorem is then used to construct the corresponding multidimensional phase space. The dynamics of the heartbeat rate signal are then analyzed before, during and after an epileptic seizure by examining the maximum Lyapunov exponent and the correlation dimension of the attractors in the reconstructed phase space. In general, the results reveal that the heartbeat rate signal transits from an aperiodic, highly-complex behaviour before an epileptic seizure to a low dimensional chaotic motion during the seizure event. Following the seizure, the signal trajectories return to a highly-complex state, and the complex signal patterns associated with normal physiological conditions reappear.

  2. Nonequilibrium dynamics of spin-boson models from phase-space methods

    Science.gov (United States)

    Piñeiro Orioli, Asier; Safavi-Naini, Arghavan; Wall, Michael L.; Rey, Ana Maria

    2017-09-01

    An accurate description of the nonequilibrium dynamics of systems with coupled spin and bosonic degrees of freedom remains theoretically challenging, especially for large system sizes and in higher than one dimension. Phase-space methods such as the truncated Wigner approximation (TWA) have the advantage of being easily scalable and applicable to arbitrary dimensions. In this work we adapt the TWA to generic spin-boson models by making use of recently developed algorithms for discrete phase spaces [J. Schachenmayer, A. Pikovski, and A. M. Rey, Phys. Rev. X 5, 011022 (2015), 10.1103/PhysRevX.5.011022]. Furthermore we go beyond the standard TWA approximation by applying a scheme based on the Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy of equations to our coupled spin-boson model. This allows us, in principle, to study how systematically adding higher-order corrections improves the convergence of the method. To test various levels of approximation we study an exactly solvable spin-boson model, which is particularly relevant for trapped-ion arrays. Using TWA and its BBGKY extension we accurately reproduce the time evolution of a number of one- and two-point correlation functions in several dimensions and for an arbitrary number of bosonic modes.

  3. Non-singular Brans-Dicke collapse in deformed phase space

    CERN Document Server

    Rasouli, S M M; Jalalzadeh, S; Moniz, P V

    2016-01-01

    We study the collapse process of a homogeneous perfect fluid (in FLRW background) with a barotropic equation of state in Brans-Dicke (BD) theory in the presence of phase space deformation effects. Such a deformation is introduced as a particular type of non-commutativity between phase space coordinates. For the commutative case, it has been shown in the literature [M.A. Scheel, S.L. Shapiro and S.A. Teukolsky, Phys. Rev. D. 51, 4236 (1995)], that the dust collapse in BD theory leads to the formation of a spacetime singularity which is covered by an event horizon. In comparison to general relativity (GR), the authors concluded that the final state of black holes in BD theory is identical to the GR case but differs from GR during the dynamical evolution of the collapse process. However, the presence of non-commutative effects influences the dynamics of the collapse scenario and consequently a non-singular evolution is developed in the sense that a bounce emerges at a minimum radius, after which an expanding pha...

  4. On Dual Phase-Space Relativity, the Machian Principle and Modified Newtonian Dynamics

    Directory of Open Access Journals (Sweden)

    Castro C.

    2005-04-01

    Full Text Available We investigate the consequences of the Mach’s principle of inertia within the context of the Dual Phase Space Relativity which is compatible with the Eddington-Dirac large numbers coincidences and may provide with a physical reason behind the observed anomalous Pioneer acceleration and a solution to the riddle of the cosmological constant problem. The cosmological implications of Non-Archimedean Geometry by assigning an upper impossible scale in Nature and the cosmological variations of the fundamental constants are also discussed. We study the corrections to Newtonian dynamics resulting from the Dual Phase Space Relativity by analyzing the behavior of a test particle in a modified Schwarzschild geometry (due to the the effects of the maximal acceleration that leads in the weak-field approximation to essential modifications of the Newtonian dynamics and to violations of the equivalence principle. Finally we follow another avenue and find modified Newtonian dynamics induced by the Yang’s Noncommutative Spacetime algebra involving a lower and upper scale in Nature.

  5. Phase space mass bound for fermionic dark matter from dwarf spheroidal galaxies

    Science.gov (United States)

    Paolo, Chiara Di; Nesti, Fabrizio; Villante, Francesco L.

    2018-01-01

    We reconsider the lower bound on the mass of a fermionic dark matter (DM) candidate resulting from the existence of known small Dwarf Spheroidal galaxies, in the hypothesis that their DM halo is constituted by degenerate fermions, with phase-space density limited by the Pauli exclusion principle. By relaxing the common assumption that the DM halo scale radius is tied to that of the luminous stellar component and by marginalizing on the unknown stellar velocity dispersion anisotropy, we prove that observations lead to rather weak constraints on the DM mass, that could be as low as tens of eV. In this scenario, however, the DM halos would be quite large and massive, so that a bound stems from the requirement that the time of orbital decay due to dynamical friction in the hosting Milky Way DM halo is longer than their lifetime. The smallest and nearest satellites Segue I and Willman I lead to a final lower bound of m ≳ 100 eV, still weaker than previous estimates but robust and independent on the model of DM formation and decoupling. We thus show that phase space constraints do not rule out the possibility of sub-keV fermionic DM.

  6. Seeds of Life in Space (SOLIS). II. Formamide in protostellar shocks: Evidence for gas-phase formation

    Science.gov (United States)

    Codella, C.; Ceccarelli, C.; Caselli, P.; Balucani, N.; Barone, V.; Fontani, F.; Lefloch, B.; Podio, L.; Viti, S.; Feng, S.; Bachiller, R.; Bianchi, E.; Dulieu, F.; Jiménez-Serra, I.; Holdship, J.; Neri, R.; Pineda, J. E.; Pon, A.; Sims, I.; Spezzano, S.; Vasyunin, A. I.; Alves, F.; Bizzocchi, L.; Bottinelli, S.; Caux, E.; Chacón-Tanarro, A.; Choudhury, R.; Coutens, A.; Favre, C.; Hily-Blant, P.; Kahane, C.; Jaber Al-Edhari, A.; Laas, J.; López-Sepulcre, A.; Ospina, J.; Oya, Y.; Punanova, A.; Puzzarini, C.; Quenard, D.; Rimola, A.; Sakai, N.; Skouteris, D.; Taquet, V.; Testi, L.; Theulé, P.; Ugliengo, P.; Vastel, C.; Vazart, F.; Wiesenfeld, L.; Yamamoto, S.

    2017-09-01

    Context. Modern versions of the Miller-Urey experiment claim that formamide (NH2CHO) could be the starting point for the formation of metabolic and genetic macromolecules. Intriguingly, formamide is indeed observed in regions forming solar-type stars and in external galaxies. Aims: How NH2CHO is formed has been a puzzle for decades: our goal is to contribute to the hotly debated question of whether formamide is mostly formed via gas-phase or grain surface chemistry. Methods: We used the NOrthern Extended Millimeter Array (NOEMA) interferometer to image NH2CHO towards the L1157-B1 blue-shifted shock, a well-known interstellar laboratory, to study how the components of dust mantles and cores released into the gas phase triggers the formation of formamide. Results: We report the first spatially resolved image (size 9″, 2300 AU) of formamide emission in a shocked region around a Sun-like protostar: the line profiles are blueshifted and have a FWHM ≃ 5 km s-1. A column density of NNH2CHO = 8 × 1012 cm-1 and an abundance, with respect to H-nuclei, of 4 × 10-9 are derived. We show a spatial segregation of formamide with respect to other organic species. Our observations, coupled with a chemical modelling analysis, indicate that the formamide observed in L1157-B1 is formed by a gas-phase chemical process and not on grain surfaces as previously suggested. Conclusions: The Seeds of Life in Space (SOLIS) interferometric observations of formamide provide direct evidence that this potentially crucial brick of life is efficiently formed in the gas phase around Sun-like protostars. The reduced datacube is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/605/L3

  7. Stord Orographic Precipitation Experiment (STOPEX: an overview of phase I

    Directory of Open Access Journals (Sweden)

    A. Sandvik

    2007-04-01

    Full Text Available STOPEX (Stord Orographic Precipitation Experiment is a research project of the Geophysical Institute, University of Bergen, Norway, dedicated to the investigation of orographic effects on fine scale precipitation patterns by a combination of numerical modelling and tailored measurement campaigns. Between 24 September and 16 November 2005 the first field campaign STOPEX I has been performed at and around the island of Stord at the west coast of Norway, about 50 km south of Bergen. 12 rain gauges and 3 autonomous weather stations have been installed to measure the variability of precipitation and the corresponding meteorological conditions. This paper gives an overview of the projects motivation, a description of the campaign and a presentation of the precipitation measurements performed. In addition, the extreme precipitation event around 14 November with precipitation amounts up to 240 mm in less than 24 h, is described and briefly discussed. In this context preliminary results of corresponding MM5 simulations are presented, that indicate the problems as well as potential improvement strategies with respect to modelling of fine scale orographic precipitation.

  8. Inverse problem for multispecies ferromagneticlike mean-field models in phase space with many states.

    Science.gov (United States)

    Fedele, Micaela; Vernia, Cecilia

    2017-10-01

    In this paper we solve the inverse problem for the Curie-Weiss model and its multispecies version when multiple thermodynamic states are present as in the low temperature phase where the phase space is clustered. The inverse problem consists of reconstructing the model parameters starting from configuration data generated according to the distribution of the model. We demonstrate that, without taking into account the presence of many states, the application of the inversion procedure produces very poor inference results. To overcome this problem, we use the clustering algorithm. When the system has two symmetric states of positive and negative magnetizations, the parameter reconstruction can also be obtained with smaller computational effort simply by flipping the sign of the magnetizations from positive to negative (or vice versa). The parameter reconstruction fails when the system undergoes a phase transition: In that case we give the correct inversion formulas for the Curie-Weiss model and we show that they can be used to measure how close the system gets to being critical.

  9. Intersatellite laser ranging with homodyne optical phase locking for Space Advanced Gravity Measurements mission.

    Science.gov (United States)

    Yeh, Hsien-Chi; Yan, Qi-Zhong; Liang, Yu-Rong; Wang, Ying; Luo, Jun

    2011-04-01

    In this paper, we present the scheme and the preliminary results of an intersatellite laser ranging system that is designed for the Earth's gravity recovery mission proposed in China, called Space Advanced Gravity Measurements (SAGM). The proposed intersatellite distance is about 100 km and the precision of inter-satellite range monitoring is 10 nm/Hz(1/2) at 0.1 Hz. To meet the needs, we designed a transponder-type intersatellite laser ranging system by using a homodyne optical phase locking technique, which is different from the heterodyne optical phase-locked loop used in GRACE follow-on mission. Since an ultrastable oscillator is unnecessary in the homodyne phase-locked loop, the measurement error caused by the frequency instability of the ultrastable oscillator need not be taken into account. In the preliminary study, a heterodyne interferometer with 10-m baseline (measurement arm-length) was built up to demonstrate the validity of the measurement scheme. The measurement results show that a resolution of displacement measurement of about 3.2 nm had been achieved. © 2011 American Institute of Physics

  10. PHASES: Opto-mechanical solutions to perform absolute spectrophotometry from space

    Directory of Open Access Journals (Sweden)

    Vather Dinesh

    2013-04-01

    Full Text Available This work provides an update of the current status of PHASES, which is a project aimed at developing a space-borne telescope to perform absolute flux calibrated spectroscopy of bright stars. PHASES will make it possible to measure micromagnitude photometric variations due to, e.g., exo-planet/moon transits. It is designed to obtain 1% RMS flux calibrated low resolution spectra in the wavelength range 370–960 nm with signal-to-noise ratios >100 for stars with V<10 in short integration times of ∼1 minute. The strategy to calibrate the system using A-type stars is outlined. PHASES will make possible a complete characterization of stars, some of them hosting planets. From the comparison of observed spectra with accurate model atmospheres stellar angular diameters will be determined with precisions of ∼0.5%. The light curves of transiting systems will be then used to extract the radius of the planet with similar precision. The demanding scientific requirements to be achieved under extreme observing conditions have shaped the optomechanical design. A computational model and a high-precision interferometric system have been developed to test the performance of the instrument.

  11. The numerical solution of thawing process in phase change slab using variable space grid technique

    Directory of Open Access Journals (Sweden)

    Serttikul, C.

    2007-09-01

    Full Text Available This paper focuses on the numerical analysis of melting process in phase change material which considers the moving boundary as the main parameter. In this study, pure ice slab and saturated porous packed bed are considered as the phase change material. The formulation of partial differential equations is performed consisting heat conduction equations in each phase and moving boundary equation (Stefan equation. The variable space grid method is then applied to these equations. The transient heat conduction equations and the Stefan condition are solved by using the finite difference method. A one-dimensional melting model is then validated against the available analytical solution. The effect of constant temperature heat source on melting rate and location of melting front at various times is studied in detail.It is found that the nonlinearity of melting rate occurs for a short time. The successful comparison with numerical solution and analytical solution should give confidence in the proposed mathematical treatment, and encourage the acceptance of this method as useful tool for exploring practical problems such as forming materials process, ice melting process, food preservation process and tissue preservation process.

  12. The experience of lived space in persons with dementia: a systematic meta-synthesis.

    Science.gov (United States)

    Førsund, Linn Hege; Grov, Ellen Karine; Helvik, Anne-Sofie; Juvet, Lene Kristine; Skovdahl, Kirsti; Eriksen, Siren

    2018-02-01

    Identifying how persons with dementia experience lived space is important for enabling supportive living environments and creating communities that compensate for the fading capabilities of these persons. Several single studies have explored this topic; however, few studies have attempted to explicitly review and synthesize this research literature. The aim of this systematic meta-synthesis was therefore to interpret and synthesize knowledge regarding persons with dementia's experience of space. A systematic, computerized search of AgeLine, CINAHL Complete, Embase, Medline and PsycINFO was conducted using a search strategy that combined MeSH terms and text words for different types of dementia with different descriptions of experience. Studies with 1) a sample of persons with dementia, 2) qualitative interviews as a research method and 3) a description of experiences of lived space were included. The search resulted in 1386 articles, of which 136 were identified as eligible and were read and assessed using the CASP criteria. The analysis was inspired by qualitative content analyses. This interpretative qualitative meta-synthesis included 45 articles encompassing interviews with 672 persons with dementia. The analysis showed that living in one's own home and living in long-term care established different settings and posed diverse challenges for the experience of lived space in persons with dementia. The material revealed four main categories that described the experience of lived space: (1) belonging; (2) meaningfulness; (3) safety and security; and (4) autonomy. It showed how persons with dementia experienced a reduction in their lived space due to the progression of dementia. A comprehensive understanding of the categories led to the latent theme: "Living with dementia is like living in a space where the walls keep closing in". This meta-synthesis reveals a process whereby lived space gradually becomes smaller for persons with dementia. This underscores the

  13. Ion Irradiation Experiments on the Murchison CM2 Carbonaceous Chondrite: Simulating Space Weathering of Primitive Asteroids

    Science.gov (United States)

    Keller, L. P.; Christoffersen, R.; Dukes, C. A.; Baragiola, R. A.; Rahman, Z.

    2015-01-01

    Remote sensing observations show that space weathering processes affect all airless bodies in the Solar System to some degree. Sample analyses and lab experiments provide insights into the chemical, spectroscopic and mineralogic effects of space weathering and aid in the interpretation of remote- sensing data. For example, analyses of particles returned from the S-type asteroid Itokawa by the Hayabusa mission revealed that space-weathering on that body was dominated by interactions with the solar wind acting on LL ordinary chondrite-like materials [1, 2]. Understanding and predicting how the surface regoliths of primitive carbonaceous asteroids respond to space weathering processes is important for future sample return missions (Hayabusa 2 and OSIRIS-REx) that are targeting objects of this type. Here, we report the results of our preliminary ion irradiation experiments on a hydrated carbonaceous chondrite with emphasis on microstructural and infrared spectral changes.

  14. Characterization of cumulus cloud fields using trajectories in the center of gravity versus water mass phase space: 1. Cloud tracking and phase space description: CENTER OF GRAVITY VERSUS WATER MASS 1

    Energy Technology Data Exchange (ETDEWEB)

    Heiblum, Reuven H. [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel; Altaratz, Orit [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel; Koren, Ilan [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel; Feingold, Graham [Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder Colorado USA; Kostinski, Alexander B. [Department of Physics, Michigan Technological University, Houghton Michigan USA; Khain, Alexander P. [The Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem Israel; Ovchinnikov, Mikhail [Atmosphere Science and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Fredj, Erick [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel; Dagan, Guy [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel; Pinto, Lital [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel; Yaish, Ricki [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel; Chen, Qian [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel

    2016-06-07

    We study the evolution of warm convective cloud fields using large eddy simulations of continental and trade cumulus. Individual clouds are tracked a posteriori from formation to dissipation using a 3D cloud tracking algorithm and results are presented in the phase- space of center of gravity altitude versus cloud liquid water mass (CvM space). The CvM space is shown to contain rich information on cloud field characteristics, cloud morphology, and common cloud development pathways, together facilitating a comprehensive understanding of the cloud field. In this part we show how the meteorological (thermodynamic) conditions that determine the cloud properties are projected on the CvM phase space and how changes in the initial conditions affect the clouds' trajectories in this space. This part sets the stage for a detailed microphysical analysis that will be shown in part II.

  15. NIAC Phase II Orbiting Rainbows: Future Space Imaging with Granular Systems

    Science.gov (United States)

    Quadrelli, Marco B.; Basinger, Scott; Arumugam, Darmindra; Swartzlander, Grover

    2017-01-01

    allow for unprecedented high resolution to discern continents and important features of other planets, hyperspectral imaging, adaptive systems, spectroscopy imaging through limb, and stable optical systems from Lagrange-points. Furthermore, future micro-miniaturization might hold promise of a further extension of our dust aperture concept to other more exciting smart dust concepts with other associated capabilities. Our objective in Phase II was to experimentally and numerically investigate how to optically manipulate and maintain the shape of an orbiting cloud of dust-like matter so that it can function as an adaptable ultra-lightweight surface. Our solution is based on the aperture being an engineered granular medium, instead of a conventional monolithic aperture. This allows building of apertures at a reduced cost, enables extremely fault-tolerant apertures that cannot otherwise be made, and directly enables classes of missions for exoplanet detection based on Fourier spectroscopy with tight angular resolution and innovative radar systems for remote sensing. In this task, we have examined the advanced feasibility of a crosscutting concept that contributes new technological approaches for space imaging systems, autonomous systems, and space applications of optical manipulation. The proposed investigation has matured the concept that we started in Phase I to TRL 3, identifying technology gaps and candidate system architectures for the space-borne cloud as an aperture.

  16. Life in extraterrestrial space: An anthropological consideration on astronauts' everyday experiences

    OpenAIRE

    Sato, Tomohisa; 佐藤, 知久

    2015-01-01

    Since the completion of the International Space Station (ISS) in 2000, over 80 astronauts have experienced months of life in extraterrestrial space. Based on an analysis of texts mainly written by three Japanese ISS astronauts (Wakata, Noguchi, and Furukawa), this paper examines the meanings of their daily experiences in the ISS from three perspectives: psychological, physical, and ontological. These perspectives were chosen based on the following: ||1) Psychological studies show that long-du...

  17. Space and Affect: Using Heidegger to Re-interpret the Disability Experience

    OpenAIRE

    Josephine A. Seguna

    2015-01-01

    Space, a vital element of contemporary social boundaries, has prompted debate into the significance, embodiment, construction of spatiality and the marginality and exclusion of minorities. Such 'disabled' relations' at the intersection of self and other, self and self, and self and objects function through spatial organization and negotiations of power in everyday experiences. Martin Heidegger's interpretation of space (Being and Time, 1927) allows for new considerations of existence in relat...

  18. Preliminary results obtained with the ZEUS phasing sensor within the APE experiment

    Science.gov (United States)

    Surdej, I.; Luong, B.; Vigan, A.; Araujo, C.; Bourtembourg, R.; Brast, R.; Duhoux, P.; Dupuy, C.; Frank, C.; Gonte, F.; Karban, R.; Mazzoleni, R.; Noethe, L.; Yaitskova, N.; Dohlen, K.

    2008-07-01

    In the framework of the Active Phasing Experiment (APE), four different phasing techniques are tested. The ZErnike Unit for Segment phasing sensor (ZEUS) is integrated on the APE bench. APE has been tested in the laboratory before it will be installed on one of the Nasmyth platform of a Very Large Telescope (VLT) Unit Telescope to perform on sky tests. The ZEUS phasing sensor concept has its origins in the Mach-Zehnder interferometer equipped with a spatial filter in its focal plane. In this paper, the ZEUS phasing sensor is described together with its theoretical background and deployment within the APE experiment. The algorithms and its elements used to reconstruct the wavefront are described. Finally, the preliminary results obtained in the laboratory are presented.

  19. Phase identification for space charge measurement under periodic stress of an arbitrary waveform based on the Hilbert transform

    Science.gov (United States)

    Wu, Jiandong; Huang, Ruodong; Wan, Jiadong; Chen, Yading; Yin, Yi; Chen, George

    2016-04-01

    Data processing (i.e. phase identification) using the instantaneous phase φ‧(t) defined by the Hilbert transform is discussed to confirm the detecting phase of the space charge observed by the pulsed electroacoustic method under the periodic wave V a (t). The discrete voltage V a (i) of the periodic wave at the detecting phase φ(i) is used for phase identification, and φ(i) is equally distributed to obtain N p divisions for the phase within one period. The accuracy of the discrete instantaneous phase φ‧(i) is significantly determined by the number of samples N for the discrete voltage V a (i). The instantaneous phase is consistent with the real phase of pure sine and cosine waves, and this phase linearly varies with time. However, the instantaneous phase non-linearly varies with time under the periodic stress of arbitrary waveforms. This limitation can be resolved using the base wave component, i.e. sine or cosine wave of V a (t), which is acquired by the Fourier transform. Finally, the space charge behaviour in low-density polyethylene under square and sine waves with offset is detected to verify the accuracy and effectiveness of the proposed method.

  20. Phase-space densities and effects of resonance decays in a hydrodynamic approach to heavy ion collisions

    CERN Document Server

    Akkelin, S V; 10.1103/PhysRevC.70.064901

    2004-01-01

    A method allowing analysis of the overpopulation of phase space in heavy ion collisions in a model-independent way is proposed within the hydrodynamic approach. It makes it possible to extract a chemical potential of thermal pions at freeze-out, irrespective of the form of freeze-out (isothermal) hypersurface in Minkowski space and transverse flows on it. The contributions of resonance (with masses up to 2 GeV) decays to spectra, interferometry volumes, and phase- space densities are calculated and discussed in detail. The estimates of average phase-space densities and chemical potentials of thermal pions are obtained for SPS and RHIC energies. They demonstrate that multibosonic phenomena at those energies might be considered as a correction factor rather than as a significant physical effect. The analysis of the evolution of the pion average phase-space density in chemically frozen hadron systems shows that it is almost constant or slightly increases with time while the particle density and phase- space dens...