WorldWideScience

Sample records for polar orbiting platform

  1. Detecting Canopy Water Status Using Shortwave Infrared Reflectance Data From Polar Orbiting and Geostationary Platforms

    DEFF Research Database (Denmark)

    Fensholt, Rasmus; Huber Gharib, Silvia; Proud, Simon Richard

    2010-01-01

    -based canopy water status detection from geostationary Meteosat Second Generation (MSG) Spinning Enhanced Visible and Infrared Imager (SEVIRI) data as compared to polar orbiting environmental satellite (POES)-based moderate resolution imaging spectroradiometer (MODIS) data. The EO-based SWIR water stress index...... (SIWSI) is evaluated against in situ measured canopy water content indicators at a semi-arid grassland savanna site in Senegal 2008. Daily SIWSI from both MODIS and SEVIRI data show an overall inverse relation to Normalized Difference Vegetation Index (NDVI) throughout the growing season. SIWSI...... for SWIR-based canopy water status and stress monitoring in a semi-arid environment....

  2. Reliable retrieval of atmospheric and aquatic parameters in coastal and inland environments from polar-orbiting and geostationary platforms: challenges and opportunities

    Science.gov (United States)

    Stamnes, Knut; Li, Wei; Lin, Zhenyi; Fan, Yongzhen; Chen, Nan; Gatebe, Charles; Ahn, Jae-Hyun; Kim, Wonkook; Stamnes, Jakob J.

    2017-04-01

    Simultaneous retrieval of aerosol and surface properties by means of inverse techniques based on a coupled atmosphere-surface radiative transfer model, neural networks, and optimal estimation can yield considerable improvements in retrieval accuracy in complex aquatic environments compared with traditional methods. Remote sensing of such environments represent specific challenges due (i) the complexity of the atmosphere and water inherent optical properties, (ii) unique bidirectional dependencies of the water-leaving radiance, and (iii) the desire to do retrievals for large solar zenith and viewing angles. We will discuss (a) how challenges related to atmospheric gaseous absorption, absorbing aerosols, and turbid waters can be addressed by using a coupled atmosphere-surface radiative transfer (forward) model in the retrieval process, (b) how the need to correct for bidirectional effects can be accommodated in a systematic and reliable manner, (c) how polarization information can be utilized, (d) how the curvature of the atmosphere can be taken into account, and (e) how neural networks and optimal estimation can be used to obtain fast yet accurate retrievals. Special emphasis will be placed on how information from existing and future sensors deployed on polar-orbiting and geostationary platforms can be obtained in a reliable and accurate manner. The need to provide uncertainty assessments and error budgets will also be discussed.

  3. Ejectile polarization and nuclear orbitals

    International Nuclear Information System (INIS)

    Ohnishi, A.; Maruyama, T.; Horiuchi, H.

    1992-01-01

    Ejectile polarization phenomena are studied by the use of 'Quantum Molecular Dynamics plus external mean field' model. It is shown that the far-side contribution increases as the incident energy increases or the target charge decreases. The incident energy and the target dependence of ejectile polarization data is reproduced qualitatively. The near- and far-side contributions themselves are calculated to be almost monotone functions of ejectile momentum as is predicted in a simple projectile fragmentation scheme without the assumption that the linear and angular momentum transfers are negligible, and their statistical average results in various shapes in ejectile polarization

  4. NOAA Polar-orbiting Operational Environmental Satellites (POES) Radiometer Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Polar-orbiting Operational Environmental Satellite (POES) series offers the advantage of daily global coverage, by making nearly polar orbits 14 times per day...

  5. Polarized atomic orbitals for linear scaling methods

    Science.gov (United States)

    Berghold, Gerd; Parrinello, Michele; Hutter, Jürg

    2002-02-01

    We present a modified version of the polarized atomic orbital (PAO) method [M. S. Lee and M. Head-Gordon, J. Chem. Phys. 107, 9085 (1997)] to construct minimal basis sets optimized in the molecular environment. The minimal basis set derives its flexibility from the fact that it is formed as a linear combination of a larger set of atomic orbitals. This approach significantly reduces the number of independent variables to be determined during a calculation, while retaining most of the essential chemistry resulting from the admixture of higher angular momentum functions. Furthermore, we combine the PAO method with linear scaling algorithms. We use the Chebyshev polynomial expansion method, the conjugate gradient density matrix search, and the canonical purification of the density matrix. The combined scheme overcomes one of the major drawbacks of standard approaches for large nonorthogonal basis sets, namely numerical instabilities resulting from ill-conditioned overlap matrices. We find that the condition number of the PAO overlap matrix is independent from the condition number of the underlying extended basis set, and consequently no numerical instabilities are encountered. Various applications are shown to confirm this conclusion and to compare the performance of the PAO method with extended basis-set calculations.

  6. Using Orbital Platforms to Study Planet Formation

    Science.gov (United States)

    Brisset, J.; Colwell, J. E.; Dove, A.; Maukonen, D.

    2017-08-01

    We will present results from the ISS NanoRocks experiment as well as the design of the Q-PACE CubeSat to demonstrate how orbital miniaturized payloads can be used to collect unprecedented amounts of data on the collision behavior of PPD dust grains.

  7. Polar-Orbiting Satellite (POES) Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Visible and Infrared satellite imagery taken from camera systems or radiometer instruments on satellites in orbit around the poles. Satellite campaigns include...

  8. Relativity mission with two counter-orbiting polar satellites

    International Nuclear Information System (INIS)

    Van Patten, R.A.; Everitt, C.W.F.

    1975-01-01

    In 1918, J. Lense and H. Thirring calculated that a moon in orbit around a massive rotating planet would experience a nodal dragging effect due to general relativity. An experiment to measure this effect with two counter-orbiting drag-free satellites in polar earth orbit is described. For a 2 1 / 2 year experiment, the measurement accuracy should approach 1 percent. In addition to precision tracking data from existing ground stations, satellite-to-satellite Doppler ranging data are taken at points of passing near the poles. New geophysical information on both earth harmonics and tidal effects is inherent in the polar ranging data. (auth)

  9. Orbit Correction for the Newly Developed Polarization-Switching Undulator

    Science.gov (United States)

    Obina, Takashi; Honda, Tohru; Shioya, Tatsuro; Kobayashi, Yukinori; Tsuchiya, Kimichika; Yamamoto, Shigeru

    2007-01-01

    A new scheme of undulator magnet arrangements has been proposed and developed as a polarization-switching radiation source, and its test-stand was installed in the 2.5-GeV Photon Factory storage ring (PF ring) in order to investigate the effects on the beam orbit. The closed orbit distortion (COD) over 200 μm was produced in a vertical direction when we switched the polarization of the radiation from the test-stand. In a horizontal direction, the COD was less than 50μm. The results agreed well with the predictions from the magnetic-field measurement on the bench. In order to suppress the CODs and realize a stable operation of the ring with the polarization-switching, we developed an orbit correction system which consists of an encoder to detect motion of magnets, a pair of beam position monitors (BPMs), signal processing parts, and a pair of steering magnets. We succeeded in suppressing the CODs to the level below 3μm using the system even when we switch the polarization at a maximum frequency of 0.8 Hz.

  10. Earth observation from the manned low Earth orbit platforms

    Science.gov (United States)

    Guo, Huadong; Dou, Changyong; Zhang, Xiaodong; Han, Chunming; Yue, Xijuan

    2016-05-01

    The manned low Earth orbit platforms (MLEOPs), e.g., the U.S. and Russia's human space vehicles, the International Space Station (ISS) and Chinese Tiangong-1 experimental space laboratory not only provide laboratories for scientific experiments in a wide range of disciplines, but also serve as exceptional platforms for remote observation of the Earth, astronomical objects and space environment. As the early orbiting platforms, the MLEOPs provide humans with revolutionary accessibility to the regions on Earth never seen before. Earth observation from MLEOPs began in early 1960s, as a part of manned space flight programs, and will continue with the ISS and upcoming Chinese Space Station. Through a series of flight missions, various and a large amount of Earth observing datasets have been acquired using handheld cameras by crewmembers as well as automated sophisticated sensors onboard these space vehicles. Utilizing these datasets many researches have been conducted, demonstrating the importance and uniqueness of studying Earth from a vantage point of MLEOPs. For example, the first, near-global scale digital elevation model (DEM) was developed from data obtained during the shuttle radar topography mission (SRTM). This review intends to provide an overview of Earth observations from MLEOPs and present applications conducted by the datasets collected by these missions. As the ISS is the most typical representative of MLEOPs, an introduction to it, including orbital characteristics, payload accommodations, and current and proposed sensors, is emphasized. The advantages and challenges of Earth observation from MLEOPs, using the ISS as an example, is also addressed. At last, a conclusive note is drawn.

  11. Suomi National Polar-Orbiting Partnership Visible Infrared Imaging Radiometer Suite Polarization Sensitivity Analysis

    Science.gov (United States)

    Sun, Junqiang; Xiong, Xiaoxiong; Waluschka, Eugene; Wang, Menghua

    2016-01-01

    The Visible Infrared Imaging Radiometer Suite (VIIRS) is one of five instruments onboard the Suomi National Polar-Orbiting Partnership (SNPP) satellite that launched from Vandenberg Air Force Base, California, on October 28, 2011. It is a whiskbroom radiometer that provides +/-56.28deg scans of the Earth view. It has 22 bands, among which 14 are reflective solar bands (RSBs). The RSBs cover a wavelength range from 410 to 2250 nm. The RSBs of a remote sensor are usually sensitive to the polarization of incident light. For VIIRS, it is specified that the polarization factor should be smaller than 3% for 410 and 862 nm bands and 2.5% for other RSBs for the scan angle within +/-45deg. Several polarization sensitivity tests were performed prelaunch for SNPP VIIRS. The first few tests either had large uncertainty or were less reliable, while the last one was believed to provide the more accurate information about the polarization property of the instrument. In this paper, the measured data in the last polarization sensitivity test are analyzed, and the polarization factors and phase angles are derived from the measurements for all the RSBs. The derived polarization factors and phase angles are band, detector, and scan angle dependent. For near-infrared bands, they also depend on the half-angle mirror side. Nevertheless, the derived polarization factors are all within the specification, although the strong detector dependence of the polarization parameters was not expected. Compared to the Moderate Resolution Imaging Spectroradiometer on both Aqua and Terra satellites, the polarization effect on VIIRS RSB is much smaller.

  12. Spin-orbit controlled capacitance of a polar heterostructure

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Kevin; Kopp, Thilo [Center for Electronic Correlations and Magnetism, EP VI, Institute of Physics, University of Augsburg, 86135 Augsburg (Germany); Loder, Florian [Center for Electronic Correlations and Magnetism, EP VI and TP III, Institute of Physics, University of Augsburg, 86135 Augsburg (Germany)

    2015-07-01

    Oxide heterostructures with polar films display special electronic properties, such as the electronic reconstruction at their internal interfaces with the formation of two-dimensional metallic states. Moreover, the electrical field from the polar layers is inversion-symmetry breaking and may generate a strong Rashba spin-orbit coupling (RSOC) in the interfacial electronic system. We investigate the capacitance of a heterostructure in which a strong RSOC at a metallic interface is controlled by the electric field of a surface electrode. Such a structure is for example given by a LaAlO{sub 3} film on a SrTiO{sub 3} substrate which is gated by a top electrode. We find that due to a strong RSOC the capacitance can be larger than the classical geometric value.

  13. Electrical polarization and orbital magnetization: the modern theories

    International Nuclear Information System (INIS)

    Resta, Raffaele

    2010-01-01

    Macroscopic polarization P and magnetization M are the most fundamental concepts in any phenomenological description of condensed media. They are intensive vector quantities that intuitively carry the meaning of dipole per unit volume. But for many years both P and the orbital term in M evaded even a precise microscopic definition, and severely challenged quantum-mechanical calculations. If one reasons in terms of a finite sample, the electric (magnetic) dipole is affected in an extensive way by charges (currents) at the sample boundary, due to the presence of the unbounded position operator in the dipole definitions. Therefore P and the orbital term in M-phenomenologically known as bulk properties-apparently behave as surface properties; only spin magnetization is problemless. The field has undergone a genuine revolution since the early 1990s. Contrary to a widespread incorrect belief, P has nothing to do with the periodic charge distribution of the polarized crystal: the former is essentially a property of the phase of the electronic wavefunction, while the latter is a property of its modulus. Analogously, the orbital term in M has nothing to do with the periodic current distribution in the magnetized crystal. The modern theory of polarization, based on a Berry phase, started in the early 1990s and is now implemented in most first-principle electronic structure codes. The analogous theory for orbital magnetization started in 2005 and is partly work in progress. In the electrical case, calculations have concerned various phenomena (ferroelectricity, piezoelectricity, and lattice dynamics) in several materials, and are in spectacular agreement with experiments; they have provided thorough understanding of the behaviour of ferroelectric and piezoelectric materials. In the magnetic case the very first calculations are appearing at the time of writing (2010). Here I review both theories on a uniform ground in a density functional theory (DFT) framework, pointing out

  14. Investigating the auroral electrojets with low altitude polar orbiting satellites

    DEFF Research Database (Denmark)

    Moretto, T.; Olsen, Nils; Ritter, P.

    2002-01-01

    Three geomagnetic satellite missions currently provide high precision magnetic field measurements from low altitude polar orbiting spacecraft. We demonstrate how these data can be used to determine the intensity and location of the horizontal currents that flow in the ionosphere, predominantly...... to another event for which the combined measurements of the three satellites provide a comprehensive view of the current systems. The analysis hereof reveals some surprising results concerning the connection between solar wind driver and the resulting ionospheric currents. Specifically, preconditioning.......8-0.9) is observed between the amplitudes of the derived currents and the commonly used auroral electro-jet indices based on magnetic measurements at ground. This points to the potential of defining an auroral activity index based on the satellite observations, which could be useful for space weather monitoring...

  15. Towards Polarization Diversity on the SOI Platform With Simple Fabrication Process

    DEFF Research Database (Denmark)

    Ding, Yunhong; Liu, Liu; Peucheret, Christophe

    2011-01-01

    We present a polarization diversity circuit built on the silicon-on-insulator (SOI) platform, which can be fabricated by a simple process. The polarization diversity is based on two identical air-clad asymmetrical directional couplers, which simultaneously play the roles of polarization splitter...... and rotator. A silicon polarization diversity circuit with a single microring resonator is fabricated on the SOI platform. Only ${1-dB polarization-dependent loss is demonstrated. A significant improvement of the polarization dependence is obtained for 20-Gb/s nonreturn-to-zero differential phase-shift keying...

  16. Investigating the auroral electrojets with low altitude polar orbiting satellites

    Directory of Open Access Journals (Sweden)

    T. Moretto

    2002-07-01

    Full Text Available Three geomagnetic satellite missions currently provide high precision magnetic field measurements from low altitude polar orbiting spacecraft. We demonstrate how these data can be used to determine the intensity and location of the horizontal currents that flow in the ionosphere, predominantly in the auroral electrojets. First, we examine the results during a recent geomagnetic storm. The currents derived from two satellites at different altitudes are in very good agreement, which verifies good stability of the method. Further, a very high degree of correlation (correlation coefficients of 0.8–0.9 is observed between the amplitudes of the derived currents and the commonly used auroral electrojet indices based on magnetic measurements at ground. This points to the potential of defining an auroral activity index based on the satellite observations, which could be useful for space weather monitoring. A specific advantage of the satellite observations over the ground-based magnetic measurements is their coverage of the Southern Hemisphere, as well as the Northern. We utilize this in an investigation of the ionospheric currents observed in both polar regions during a period of unusually steady interplanetary magnetic field with a large negative Y-component. A pronounced asymmetry is found between the currents in the two hemispheres, which indicates real inter-hemispheric differences beyond the mirror-asymmetry between hemispheres that earlier studies have revealed. The method is also applied to another event for which the combined measurements of the three satellites provide a comprehensive view of the current systems. The analysis hereof reveals some surprising results concerning the connection between solar wind driver and the resulting ionospheric currents. Specifically, preconditioning of the magnetosphere (history of the interplanetary magnetic field is seen to play an important role, and in the winther hemisphere, it seems to be harder to

  17. The National Polar-orbiting Operational Environmental Satellite System

    Science.gov (United States)

    Bloom, H.

    The tri-agency Integrated Program Office (IPO) is responsible for managing the development of the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS will replace the current military and civilian operational polar-orbiting ``weather'' satellites. The Northrop Grumman Space Technology - Raytheon team was competitively selected in 2002 as the Acquisition and Operations contractor team to develop, integrate, deploy, and operate NPOESS satellites to meet the tri-agency user requirements for NPOESS over the 10-year (2009-2018) operational life of the program. Beginning in 2009, NPOESS spacecraft will be launched into three orbital planes to provide significantly improved operational capabilities and benefits to satisfy critical civil and national security requirements for space-based, remotely sensed environmental data. With the development of NPOESS, we are evolving operational ``weather'' satellites into integrated environmental observing systems by expanding our capabilities to observe, assess, and predict the total Earth system - atmosphere, ocean, land, and the space environment. In recent years, the operational weather forecasting and climate science communities have levied more rigorous requirements on space-based observations of the Earth's system that have significantly increased demands on performance of the instruments, spacecraft, and ground systems required to deliver NPOESS data, products, and information to end users. The ``end-to-end'' system consists of: the spacecraft; instruments and sensors on the spacecraft; launch support capabilities; the command, control, communications, and data routing infrastructure; and data processing hardware and software. NPOESS will observe significantly more phenomena simultaneously from space than its operational predecessors. NPOESS is expected to deliver large volumes of more accurate measurements at higher spatial (horizontal and vertical) and temporal resolution at much higher data

  18. AURORA BOREALIS: a polar-dedicated European Research Platform

    Science.gov (United States)

    Wolff-Boenisch, Bonnie; Egerton, Paul; Thiede, Joern; Roberto, Azzolini; Lembke-Jene, Lester

    2010-05-01

    Polar research and in particular the properties of northern and southern high latitude oceans are currently a subject of intense scientific debate and investigations, because they are subject to rapid and dramatic climatic variations. Polar regions react more rapidly and intensively to global change than other regions of the earth. A shrinking of the Arctic sea-ice cover, potentially leading to an opening of sea passages to the north of North America and Eurasia, on the long to a "blue" Arctic Ocean would additionally have a strong impact on transport, commerce and tourism bearing potential risk for humans and complex ecosystems in the future. In spite of their critical role processes and feedbacks, especially in winter but not exclusively, are virtually unknown: The Arctic Ocean for example, it is the only basin of the world's oceans that has essentially not been sampled by the drill ships of the Deep-Sea Drilling Project (DSDP) or the Ocean Drilling Program (ODP) and its long-term environmental history and tectonic structure is therefore poorly known. Exceptions are the ODP Leg 151 and the more recent very successful ACEX-expedition of the Integrated Ocean Drilling Program (IODP) in 2004. To help to address the most pressing questions regarding climate change and related processes, a Pan-European initiative in the field of Earth system science has been put in place: AURORA BOREALIS is the largest environmental research infrastructure on the ESFRI roadmap of the European Community. AURORA BOREALIS is a very powerful research icebreaker, which will enable year-round operations in the Arctic and the Antarctic as well as in the adjacent ocean basins. Equipped with its drilling rig, the vessel is also capable to explore the presently completely unknown Arctic deep-sea floor. Last but not least, the ship is a floating observatory and mobile monitoring platform that permits to measure on a long-term basis comprehensive time series in all research fields relevant to

  19. Joint Polar Satellite System: the United States New Generation Civilian Polar Orbiting Environmental Satellite System

    Science.gov (United States)

    Mandt, G.

    2017-12-01

    The Joint Polar Satellite System (JPSS) is the Nation's advanced series of polar-orbiting environmental satellites. JPSS represents significant technological and scientific advancements in observations used for severe weather prediction and environmental monitoring. The Suomi National Polar-orbiting Partnership (S-NPP) is providing state-of-the art atmospheric, oceanographic, and environmental data, as the first of the JPSS satellites while the second in the series, J-1, is scheduled to launch in October 2017. The JPSS baseline consists of a suite of four instruments: an advanced microwave and infrared sounders which are critical for weather forecasting; a leading-edge visible and infrared imager critical to data sparse areas such as Alaska and needed for environmental assessments such as snow/ice cover, droughts, volcanic ash, forest fires and surface temperature; and an ozone sensor primarily used for global monitoring of ozone and input to weather and climate models. The same suite of instruments that are on JPSS-1 will be on JPSS-2, 3 and 4. The JPSS-2 instruments are well into their assembly and test phases and are scheduled to be completed in 2018. The JPSS-2 spacecraft critical design review (CDR) is scheduled for 2Q 2018 with the launch in 2021. The sensors for the JPSS-3 and 4 spacecraft have been approved to enter into their acquisition phases. JPSS partnership with the US National Aeronautics and Space Agency (NASA) continues to provide a strong foundation for the program's success. JPSS also continues to maintain its important international relationships with European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) and the Japan Aerospace Exploration Agency (JAXA). JPSS works closely with its user community through the Proving Ground and Risk Reduction (PGRR) Program to identify opportunities to maximize the operational application of current JPSS capabilities. The PGRR Program also helps identify and evaluate the use of JPSS

  20. Interrogation of orbital structure by elliptically polarized intense femtosecond laser pulses

    International Nuclear Information System (INIS)

    Abu-samha, M.; Madsen, L. B.

    2011-01-01

    We solve the three-dimensional time-dependent Schroedinger equation and present investigations of the imprint of the orbital angular node in photoelectron momentum distributions of an aligned atomic p-type orbital following ionization by an intense elliptically polarized laser pulse of femtosecond duration. We investigate the role of light ellipticity and the alignment angle of the major polarization axis of the external field relative to the probed orbital by studying radial and angular momentum distributions, the latter at a fixed narrow interval of final momenta close to the peak of the photoelectron momentum distribution. In general only the angular distributions carry a clear signature of the orbital symmetry. Our study shows that circular polarization gives the most clear imprints of orbital nodes. These findings are insensitive to pulse duration.

  1. Interrogation of orbital structure by elliptically polarized intense femtosecond laser pulses

    DEFF Research Database (Denmark)

    Abu-Samha, Mahmoud; Madsen, Lars Bojer

    2011-01-01

    We solve the three-dimensional time-dependent Schrödinger equation and present investigations of the imprint of the orbital angular node in photoelectron momentum distributions of an aligned atomic p-type orbital following ionization by an intense elliptically polarized laser pulse of femtosecond...

  2. Platform for Manipulating Polarization Modes Realized with Jones Vectors in MATHEMATICA

    Directory of Open Access Journals (Sweden)

    Yong-Dae Choi

    2015-06-01

    Full Text Available The fundamental conception in physics of the propagation of the electromagnetic wave polarization in matter is newly understood as the cardinal keyword in free-space quantum communication technology and cosmology in astrophysics. Interactive visualization of the propagation mechanism of polarized electromagnetism in a medium with its helicity has accordingly received attention from scientists exploiting the protocol of quantum key distribution (QKD to guarantee unconditional security in cryptography communication. We have provided a dynamic polarization platform for presenting the polarization modes of a transverse electromagnetic wave, converting the state of polarization through the arrangement of optical elements, using Jones vectors calculations in Methematica. The platform graphically simulates the mechanism of production and propagation of the polarized waves in a medium while satisfying Maxwell's equations.

  3. Current-induced spin polarization in a spin-polarized two-dimensional electron gas with spin-orbit coupling

    International Nuclear Information System (INIS)

    Wang, C.M.; Pang, M.Q.; Liu, S.Y.; Lei, X.L.

    2010-01-01

    The current-induced spin polarization (CISP) is investigated in a combined Rashba-Dresselhaus spin-orbit-coupled two-dimensional electron gas, subjected to a homogeneous out-of-plane magnetization. It is found that, in addition to the usual collision-related in-plane parts of CISP, there are two impurity-density-free contributions, arising from intrinsic and disorder-mediated mechanisms. The intrinsic parts of spin polarization are related to the Berry curvature, analogous with the anomalous and spin Hall effects. For short-range collision, the disorder-mediated spin polarizations completely cancel the intrinsic ones and the total in-plane components of CISP equal those for systems without magnetization. However, for remote disorders, this cancellation does not occur and the total in-plane components of CISP strongly depend on the spin-orbit interaction coefficients and magnetization for both pure Rashba and combined Rashba-Dresselhaus models.

  4. Ionic Potential and Band Narrowing as a Source of Orbital Polarization in Nickelate/Insulator Superlattices

    Science.gov (United States)

    Georgescu, Alexandru B.; Disa, Ankit S.; Kumah, Divine P.; Ismail-Beigi, Sohrab; Walker, Frederick J.; Ahn, Charles H.

    Nickelate interfaces display complex, interacting electronic properties such as thickness dependent metal-insulator transitions. One large body of effort involving nickelates has aimed to split the energies of the Ni 3d orbitals (orbital polarization) to make the resulting band structure resemble that of cuprate superconductors. The most commonly studied interfacial system involves superlattices of alternating nickelate and insulating perovksite-structure layers; the resulting orbital polarization at the nickelate-insulator interface is understood as being due to confinement or structural symmetry breaking. By using first principles theory on the NdNiO3/NdAlO3 superlattice, we show that another important source of orbital polarization stems from electrostatic effects: the more ionic nature of the cations in the insulator (when compared to the nickelate) can shift the relative orbital energies of the Ni. We use density functional theory (DFT) and add electronic correlations via slave-bosons to describe the effect of correlation-induced band narrowing on the orbital polarization. Work supported by NSF Grant MRSEC DMR-1119826.

  5. Research progress of anti-icing/deicing technologies for polar ships and offshore platforms

    Directory of Open Access Journals (Sweden)

    XIE Qiang

    2017-01-01

    Full Text Available The polar regions present adverse circumstances of high humidity and strong air-sea exchange. As such, the surfaces of ships and platforms (oil exploiting and drilling platforms serving in polar regions can easily be frozen by ice accretion, which not only affects the operation of the equipment but also threatens safety. This paper summarizes the status of the anti-icing/deicing technologies of both China and abroad for polar ships and offshore platforms, and introduces the various effects of ice accretion on polar ships and offshore platforms, and the resulting safety impacts. It then reviews existing anti-icing/deicing technologies and methods of both China and abroad, including such active deicing methods as electric heating, infrared heating and ultrasonic guided wave deicing, as well as such passive deicing methods as super hydrophobic coating, sacrificial coating, aqueous lubricating layer coating and low cross-link density (with interfacial slippage coating, summarizes their applicability to polar ships and offshore platforms, and finally discusses their advantages/disadvantages.

  6. Spin-orbit torque induced magnetic vortex polarity reversal utilizing spin-Hall effect

    Science.gov (United States)

    Li, Cheng; Cai, Li; Liu, Baojun; Yang, Xiaokuo; Cui, Huanqing; Wang, Sen; Wei, Bo

    2018-05-01

    We propose an effective magnetic vortex polarity reversal scheme that makes use of spin-orbit torque introduced by spin-Hall effect in heavy-metal/ferromagnet multilayers structure, which can result in subnanosecond polarity reversal without endangering the structural stability. Micromagnetic simulations are performed to investigate the spin-Hall effect driven dynamics evolution of magnetic vortex. The mechanism of magnetic vortex polarity reversal is uncovered by a quantitative analysis of exchange energy density, magnetostatic energy density, and their total energy density. The simulation results indicate that the magnetic vortex polarity is reversed through the nucleation-annihilation process of topological vortex-antivortex pair. This scheme is an attractive option for ultra-fast magnetic vortex polarity reversal, which can be used as the guidelines for the choice of polarity reversal scheme in vortex-based random access memory.

  7. Spin-polarized spin-orbit-split quantum-well states in a metal film

    Energy Technology Data Exchange (ETDEWEB)

    Varykhalov, Andrei; Sanchez-Barriga, Jaime; Gudat, Wolfgang; Eberhardt, Wolfgang; Rader, Oliver [BESSY Berlin (Germany); Shikin, Alexander M. [St. Petersburg State University (Russian Federation)

    2008-07-01

    Elements with high atomic number Z lead to a large spin-orbit coupling. Such materials can be used to create spin-polarized electronic states without the presence of a ferromagnet or an external magnetic field if the solid exhibits an inversion asymmetry. We create large spin-orbit splittings using a tungsten crystal as substrate and break the structural inversion symmetry through deposition of a gold quantum film. Using spin- and angle-resolved photoelectron spectroscopy, it is demonstrated that quantum-well states forming in the gold film are spin-orbit split and spin polarized up to a thickness of at least 10 atomic layers. This is a considerable progress as compared to the current literature which reports spin-orbit split states at metal surfaces which are either pure or covered by at most a monoatomic layer of adsorbates.

  8. Environmental Satellites: Polar-orbiting Satellite Acquisition Faces Delays; Decisions Needed on Whether and How to Ensure Climate Data Continuity

    National Research Council Canada - National Science Library

    2008-01-01

    The National Polar-orbiting Operational Environmental Satellite System (NPOESS) is a triagency acquisition managed by the Department of Commerce s National Oceanic and Atmospheric Administration (NOAA...

  9. Environmental Satellites. Polar-orbiting Satellite Acquisition Faces Delays; Decisions Needed on Whether and How to Ensure Climate Data Continuity

    National Research Council Canada - National Science Library

    2008-01-01

    The National Polar-orbiting Operational Environmental Satellite System (NPOESS) is a triagency acquisition managed by the Department of Commerce's National Oceanic and Atmospheric Administration (NOAA...

  10. Lesions to polar/orbital prefrontal cortex selectively impair reasoning about emotional material.

    Science.gov (United States)

    Goel, Vinod; Lam, Elaine; Smith, Kathleen W; Goel, Amit; Raymont, Vanessa; Krueger, Frank; Grafman, Jordan

    2017-05-01

    While it is widely accepted that lesions to orbital prefrontal cortex lead to emotion related disruptions and poor decision-making, there is very little patient data on this issue involving actual logical reasoning tasks. We tested patients with circumscribed, focal lesions largely confined to polar/orbital prefrontal cortex (BA 10 & 11) (N=17) on logical reasoning tasks involving neutral and emotional content, and compared their performance to that of an age and education-matched normal control group (N=22) and a posterior lesion control group (N=24). Our results revealed a significant group by content interaction driven by a selective impairment in the polar/orbital prefrontal cortex group compared to healthy normal controls and to the parietal patient group, in the emotional content reasoning trials. Subsequent analyses of congruent and incongruent reasoning trials indicated that this impairment was driven by the poor performance of patients with polar/orbital lesions in the incongruent trials. We conclude that the polar/orbital prefrontal cortex plays a critical role in filtering emotionally charged content from the material before it is passed on to the reasoning system in lateral/dorsal regions of prefrontal cortex. Where unfiltered content is passed to the reasoning engine, either as a result of pathology (as in the case of our patients) or as a result of individual differences, reasoning performance suffers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Circular-Polarization-Selective Transmission Induced by Spin-Orbit Coupling in a Helical Tape Waveguide

    Science.gov (United States)

    Liu, Yahong; Guo, Qinghua; Liu, Hongchao; Liu, Congcong; Song, Kun; Yang, Biao; Hou, Quanwen; Zhao, Xiaopeng; Zhang, Shuang; Navarro-Cía, Miguel

    2018-05-01

    Spin-orbit coupling of light, describing the interaction between the polarization (spin) and spatial degrees of freedom (orbit) of light, plays an important role in subwavelength scale systems and leads to many interesting phenomena, such as the spin Hall effect of light. Here, based on the spin-orbit coupling, we design and fabricate a helical tape waveguide (HTW), which can realize a circular-polarization-selective process. When the incident circularly polarized wave is of the same handedness as the helix of the HTW, a nearly complete transmission is observed; in contrast, a counterrotating circular polarization of incident wave results in a much lower transmission or is even totally blocked by the HTW. Indeed, both simulations and experiments reveal that the blocked component of power leaks through the helical aperture of the HTW and forms a conical beam analogous to helical Cherenkov radiation due to the conversion from the spin angular momentum to the orbital angular momentum. Our HTW structure demonstrates its potential as a polarization selector in a broadband frequency range.

  12. Space Station Freedom electrical power system hardware commonality with the United States Polar Platform

    Science.gov (United States)

    Rieker, Lorra L.; Haraburda, Francis M.

    1989-01-01

    Information is presented on how the concept of commonality is being implemented with respect to electric power system hardware for the Space Station Freedom and the U.S. Polar Platform. Included is a historical account of the candidate common items which have the potential to serve the same power system functions on both Freedom and the Polar Platform. The Space Station program and objectives are described, focusing on the test and development responsibilities. The program definition and preliminary design phase and the design and development phase are discussed. The goal of this work is to reduce the program cost.

  13. Mapping daily evapotranspiration at field to continental scales using geostationary and polar orbiting satellite imagery

    Directory of Open Access Journals (Sweden)

    M. C. Anderson

    2011-01-01

    Full Text Available Thermal infrared (TIR remote sensing of land-surface temperature (LST provides valuable information about the sub-surface moisture status required for estimating evapotranspiration (ET and detecting the onset and severity of drought. While empirical indices measuring anomalies in LST and vegetation amount (e.g., as quantified by the Normalized Difference Vegetation Index; NDVI have demonstrated utility in monitoring ET and drought conditions over large areas, they may provide ambiguous results when other factors (e.g., air temperature, advection are affecting plant functioning. A more physically based interpretation of LST and NDVI and their relationship to sub-surface moisture conditions can be obtained with a surface energy balance model driven by TIR remote sensing. The Atmosphere-Land Exchange Inverse (ALEXI model is a multi-sensor TIR approach to ET mapping, coupling a two-source (soil + canopy land-surface model with an atmospheric boundary layer model in time-differencing mode to routinely and robustly map daily fluxes at continental scales and 5 to 10-km resolution using thermal band imagery and insolation estimates from geostationary satellites. A related algorithm (DisALEXI spatially disaggregates ALEXI fluxes down to finer spatial scales using moderate resolution TIR imagery from polar orbiting satellites. An overview of this modeling approach is presented, along with strategies for fusing information from multiple satellite platforms and wavebands to map daily ET down to resolutions on the order of 10 m. The ALEXI/DisALEXI model has potential for global applications by integrating data from multiple geostationary meteorological satellite systems, such as the US Geostationary Operational Environmental Satellites, the European Meteosat satellites, the Chinese Fen-yung 2B series, and the Japanese Geostationary Meteorological Satellites. Work is underway to further evaluate multi-scale ALEXI implementations over the US, Europe, Africa

  14. Land Surface Temperature- Comparing Data from Polar Orbiting and Geostationary Satellites

    Science.gov (United States)

    Comyn-Platt, E.; Remedios, J. J.; Good, E. J.; Ghent, D.; Saunders, R.

    2012-04-01

    Land Surface Temperature (LST) is a vital parameter in Earth climate science, driving long-wave radiation exchanges that control the surface energy budget and carbon fluxes, which are important factors in Numerical Weather Prediction (NWP) and the monitoring of climate change. Satellites offer a convenient way to observe LST consistently and regularly over large areas. A comparison between LST retrieved from a Geostationary Instrument, the Spinning Enhanced Visible and InfraRed Imager (SEVIRI), and a Polar Orbiting Instrument, the Advanced Along Track Scanning Radiometer (AATSR) is presented. Both sensors offer differing benefits. AATSR offers superior precision and spatial resolution with global coverage but given its sun-synchronous platform only observes at two local times, ~10am and ~10pm. SEVIRI provides the high-temporal resolution (every 15 minutes) required for observing diurnal variability of surface temperatures but given its geostationary platform has a poorer resolution, 3km at nadir, which declines at higher latitudes. A number of retrieval methods are applied to the raw satellite data: First order coefficient based algorithms provided on an operational basis by the LandSAF (for SEVIRI) and the University of Leicester (for AATSR); Second order coefficient based algorithms put forward by the University of Valencia; and an optimal estimation method using the 1DVar software provided by the NWP SAF. Optimal estimation is an iterative technique based upon inverse theory, thus is very useful for expanding into data assimilation systems. The retrievals are assessed and compared on both a fine scale using in-situ data from recognised validation sites and on a broad scale using two 100x100 regions such that biases can be better understood. Overall, the importance of LST lies in monitoring daily temperature extremes, e.g. for estimating permafrost thawing depth or risk of crop damage due to frost, hence the ideal dataset would use a combination of observations

  15. Integrated Cu-based TM-pass polarizer using CMOS technology platform

    KAUST Repository

    Ng, Tien Khee

    2010-01-01

    A transverse-magnetic-pass (TM-pass) copper (Cu) polarizer is proposed and analyzed using the previously published two-dimensional Method-of-Lines beam-propagation model. The proposed polarizer exhibits a simulated high-pass filter characteristics, with TM0 and TE0 mode transmissivity of >70% and <5%, respectively, in the wavelength regime of 1.2-1.6 μm. The polarization extinction ratio (PER) given by 10 log10 (PTM0)/(PTE0) is +11.5 dB across the high-pass wavelength regime. To the best of the authors\\' knowledge, we report here the smallest footprint CMOS-platform compatible TM-polarizer.

  16. Spin-orbit-induced spin splittings in polar transition metal dichalcogenide monolayers

    KAUST Repository

    Cheng, Yingchun

    2013-06-01

    The Rashba effect in quasi two-dimensional materials, such as noble metal surfaces and semiconductor heterostructures, has been investigated extensively, while interest in real two-dimensional systems has just emerged with the discovery of graphene. We present ab initio electronic structure, phonon, and molecular-dynamics calculations to study the structural stability and spin-orbit-induced spin splitting in the transition metal dichalcogenide monolayers MXY (M = Mo, W and X, Y = S, Se, Te). In contrast to the non-polar systems with X = Y, in the polar systems with X ≠ Y the Rashba splitting at the Γ-point for the uppermost valence band is caused by the broken mirror symmetry. An enhancement of the splitting can be achieved by increasing the spin-orbit coupling and/or the potential gradient. © Copyright EPLA, 2013.

  17. MetNet - In situ observational Network and Orbital platform to investigate the Martian environment

    Science.gov (United States)

    Harri, Ari-Matti; Leinonen, Jussi; Merikallio, Sini; Paton, Mark; Haukka, Harri; Polkko, Jouni

    2007-09-01

    MetNet Mars Mission is an in situ observational network and orbital platform mission to investigate the Martian environment and it has been proposed to European Space Agency in response to Call for proposals for the first planning cycle of Cosmic Vision 2015-2025 D/SCI/DJS/SV/val/21851. The MetNet Mars Mission is to be implemented in collaboration with ESA, FMI, LA, IKI and the payload providing science teams. The scope of the MetNet Mission is to deploy 16 MetNet Landers (MNLs) on the Martian surface by using inflatable descent system structures accompanied by an atmospheric sounder and data relay onboard the MetNet Orbiter (MNO), which is based on ESA Mars Express satellite platform. The MNLs are attached on the three sides of the satellite and most of the MNLs are deployed to Mars separately a few weeks prior to the arrival to Mars. The MetNet Orbiter will perform continuous atmospheric soundings thus complementing the accurate in situ observations at the Martian ground produced by the MetNet observation network, as well as the orbiter will serve as the primary data relay between the MetNet Landers and the Earth. The MNLs are equipped with a versatile science payload focused on the atmospheric science of Mars. Detailed characterisation of the Martian atmospheric circulation patterns, boundary layer phenomena, and climatological cycles, as well as interior investigations, require simultaneous in situ meteorological, seismic and magnetic measurements from networks of stations on the Martian surface. MetNet Mars Mission will also provide a crucial support for the safety of large landing missions in general and manned Mars missions in particular. Accurate knowledge of atmospheric conditions and weather data is essential to guarantee safe landings of the forthcoming Mars mission elements.

  18. Magnetic-field fluctuations from 0 to 26 Hz observed from a polar-orbiting satellite

    International Nuclear Information System (INIS)

    Erlandson, R.E.; Zanetti, L.J.; Potemra, T.A.

    1989-01-01

    The polar orbit of the Viking satellite provides a unique opportunity to obtain observations of magnetic fluctuations at mid-altitudes on the dayside of the magnetosphere and in the polar-cusp region. One type of magnetic-field fluctuation, observed in the dayside magnetosphere, was Pc 1 waves. Pc 1 waves are in the electromagnetic ion-cyclotron mode and are generated by anisotropies in energetic ion distributions. The waves are thought to be generated near the equator and to propagate large distances along magnetic-field lines. Most observations of Pc 1 waves have been obtained near the equator using geosynchronous satellites and on the surface of the earth. The Viking observations provide an opportunity to observe Pc 1 waves at mid-latitudes above the ionosphere and to determine the spectral structure and polarization of the waves. ULF/ELF broadband noise represents a second type of magnetic fluctuation acquired by Viking. This type of magnetic fluctuation was observed at high latitudes near the polar cusp and may be useful in the identification of polar-cusp boundaries. Thirdly, electromagnetic ion-cyclotron waves have also been observed in the polar-cusp region. These waves occur only during an unusually high level of magnetic activity and appear to be generated locally

  19. Spin polarization of tunneling current in barriers with spin-orbit coupling

    International Nuclear Information System (INIS)

    Fujita, T; Jalil, M B A; Tan, S G

    2008-01-01

    We present a general method for evaluating the maximum transmitted spin polarization and optimal spin axis for an arbitrary spin-orbit coupling (SOC) barrier system, in which the spins lie in the azimuthal plane and finite spin polarization is achieved by wavevector filtering of electrons. Besides momentum filtering, another prerequisite for finite spin polarization is asymmetric occupation or transmission probabilities of the eigenstates of the SOC Hamiltonian. This is achieved most efficiently by resonant tunneling through multiple SOC barriers. We apply our analysis to common SOC mechanisms in semiconductors: pure bulk Dresselhaus SOC, heterostructures with mixed Dresselhaus and Rashba SOC and strain-induced SOC. In particular, we find that the interplay between Dresselhaus and Rashba SOC effects can yield several advantageous features for spin filter and spin injector functions, such as increased robustness to wavevector spread of electrons

  20. Spin polarization of tunneling current in barriers with spin-orbit coupling.

    Science.gov (United States)

    Fujita, T; Jalil, M B A; Tan, S G

    2008-03-19

    We present a general method for evaluating the maximum transmitted spin polarization and optimal spin axis for an arbitrary spin-orbit coupling (SOC) barrier system, in which the spins lie in the azimuthal plane and finite spin polarization is achieved by wavevector filtering of electrons. Besides momentum filtering, another prerequisite for finite spin polarization is asymmetric occupation or transmission probabilities of the eigenstates of the SOC Hamiltonian. This is achieved most efficiently by resonant tunneling through multiple SOC barriers. We apply our analysis to common SOC mechanisms in semiconductors: pure bulk Dresselhaus SOC, heterostructures with mixed Dresselhaus and Rashba SOC and strain-induced SOC. In particular, we find that the interplay between Dresselhaus and Rashba SOC effects can yield several advantageous features for spin filter and spin injector functions, such as increased robustness to wavevector spread of electrons.

  1. Medical Implications of Space Radiation Exposure Due to Low-Altitude Polar Orbits.

    Science.gov (United States)

    Chancellor, Jeffery C; Auñon-Chancellor, Serena M; Charles, John

    2018-01-01

    Space radiation research has progressed rapidly in recent years, but there remain large uncertainties in predicting and extrapolating biological responses to humans. Exposure to cosmic radiation and solar particle events (SPEs) may pose a critical health risk to future spaceflight crews and can have a serious impact on all biomedical aspects of space exploration. The relatively minimal shielding of the cancelled 1960s Manned Orbiting Laboratory (MOL) program's space vehicle and the high inclination polar orbits would have left the crew susceptible to high exposures of cosmic radiation and high dose-rate SPEs that are mostly unpredictable in frequency and intensity. In this study, we have modeled the nominal and off-nominal radiation environment that a MOL-like spacecraft vehicle would be exposed to during a 30-d mission using high performance, multicore computers. Projected doses from a historically large SPE (e.g., the August 1972 solar event) have been analyzed in the context of the MOL orbit profile, providing an opportunity to study its impact to crew health and subsequent contingencies. It is reasonable to presume that future commercial, government, and military spaceflight missions in low-Earth orbit (LEO) will have vehicles with similar shielding and orbital profiles. Studying the impact of cosmic radiation to the mission's operational integrity and the health of MOL crewmembers provides an excellent surrogate and case-study for future commercial and military spaceflight missions.Chancellor JC, Auñon-Chancellor SM, Charles J. Medical implications of space radiation exposure due to low-altitude polar orbits. Aerosp Med Hum Perform. 2018; 89(1):3-8.

  2. A planet in a polar orbit of 1.4 solar-mass star

    Directory of Open Access Journals (Sweden)

    Guenther E.W.

    2015-01-01

    Full Text Available Although more than a thousand transiting extrasolar planets have been discovered, only very few of them orbit stars that are more massive than the Sun. The discovery of such planets is interesting, because they have formed in disks that are more massive but had a shorter life time than those of solar-like stars. Studies of planets more massive than the Sun thus tell us how the properties of the proto-planetary disks effect the formation of planets. Another aspect that makes these planets interesting is that they have kept their original orbital inclinations. By studying them we can thus find out whether the orbital axes planets are initially aligned to the stars rotational axes, or not. Here we report on the discovery of a planet of a 1.4 solar-mass star with a period of 5.6 days in a polar orbit made by CoRoT. This new planet thus is one of the few known close-in planets orbiting a star that is substantially more massive than the Sun.

  3. National Polar-orbiting Operational Environmental Satellite System (NPOESS) Design and Architecture

    Science.gov (United States)

    Hinnant, F.

    2008-12-01

    The National Oceanic and Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system - the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS will replace the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD and will provide continuity for the NASA Earth Observing System (EOS) with the launch of the NPOESS Preparatory Project (NPP). This poster will provide an overview of the NPOESS architecture, which includes four segments. The space segment includes satellites in two orbits that carry a suite of sensors to collect meteorological, oceanographic, climatological, and solar-geophysical observations of the Earth, atmosphere, and near-Earth space environment. The NPOESS design allows centralized mission management and delivers high quality environmental products to military, civil and scientific users through a Command, Control, and Communication Segment (C3S). The data processing for NPOESS is accomplished through an Interface Data Processing Segment (IDPS)/Field Terminal Segment (FTS) that processes NPOESS satellite data to provide environmental data products to NOAA and DoD processing centers operated by the United States government as well as to remote terminal users. The Launch Support Segment completes the four segments that make up NPOESS that will enhance the connectivity between research and operations and provide critical operational and scientific environmental measurements to military, civil, and scientific users until 2026.

  4. Spin-orbit-coupled Bose-Einstein condensates of rotating polar molecules

    Science.gov (United States)

    Deng, Y.; You, L.; Yi, S.

    2018-05-01

    An experimental proposal for realizing spin-orbit (SO) coupling of pseudospin 1 in the ground manifold 1Σ (υ =0 ) of (bosonic) bialkali polar molecules is presented. The three spin components are composed of the ground rotational state and two substates from the first excited rotational level. Using hyperfine resolved Raman processes through two select excited states resonantly coupled by a microwave, an effective coupling between the spin tensor and linear momentum is realized. The properties of Bose-Einstein condensates for such SO-coupled molecules exhibiting dipolar interactions are further explored. In addition to the SO-coupling-induced stripe structures, the singly and doubly quantized vortex phases are found to appear, implicating exciting opportunities for exploring novel quantum physics using SO-coupled rotating polar molecules with dipolar interactions.

  5. Evaluation of sensor placement algorithms for on-orbit identification of space platforms

    Science.gov (United States)

    Glassburn, Robin S.; Smith, Suzanne Weaver

    1994-01-01

    Anticipating the construction of the international space station, on-orbit modal identification of space platforms through optimally placed accelerometers is an area of recent activity. Unwanted vibrations in the platform could affect the results of experiments which are planned. Therefore, it is important that sensors (accelerometers) be strategically placed to identify the amount and extent of these unwanted vibrations, and to validate the mathematical models used to predict the loads and dynamic response. Due to cost, installation, and data management issues, only a limited number of sensors will be available for placement. This work evaluates and compares four representative sensor placement algorithms for modal identification. Most of the sensor placement work to date has employed only numerical simulations for comparison. This work uses experimental data from a fully-instrumented truss structure which was one of a series of structures designed for research in dynamic scale model ground testing of large space structures at NASA Langley Research Center. Results from this comparison show that for this cantilevered structure, the algorithm based on Guyan reduction is rated slightly better than that based on Effective Independence.

  6. The case for a modern multiwavelength, polarization-sensitive LIDAR in orbit around Mars

    International Nuclear Information System (INIS)

    Brown, Adrian J.; Michaels, Timothy I.; Byrne, Shane; Sun, Wenbo; Titus, Timothy N.; Colaprete, Anthony; Wolff, Michael J.; Videen, Gorden; Grund, Christian J.

    2015-01-01

    We present the scientific case to build a multiple-wavelength, active, near-infrared (NIR) instrument to measure the reflected intensity and polarization characteristics of backscattered radiation from planetary surfaces and atmospheres. We focus on the ability of such an instrument to enhance, potentially revolutionize, our understanding of climate, volatiles and astrobiological potential of modern-day Mars. Such an instrument will address the following three major science themes, which we address in this paper: Science Theme 1. Surface. This would include global, night and day mapping of H 2 O and CO 2 surface ice properties. Science Theme 2. Ice Clouds. This would including unambiguous discrimination and seasonal mapping of CO 2 and H 2 O ice clouds. Science Theme 3. Dust Aerosols. This theme would include multiwavelength polarization measurements to infer dust grain shapes and size distributions. - Highlights: • We present the scientific rationale for a multi-wavelength, polarization sensitive lidar to be placed in orbit around Mars. • Scientific questions focus on the Martian climate and modern-day interactions between surface, ice clouds and dust aerosols. • What we would learn about volatile transport and deposition has implications for past, present and future life on Mars

  7. Tunable ferroelectric polarization and its interplay with spin-orbit coupling in tin iodide perovskites

    Science.gov (United States)

    Stroppa, Alessandro; di Sante, Domenico; Barone, Paolo; Bokdam, Menno; Kresse, Georg; Franchini, Cesare; Whangbo, Myung-Hwan; Picozzi, Silvia

    2014-12-01

    Ferroelectricity is a potentially crucial issue in halide perovskites, breakthrough materials in photovoltaic research. Using density functional theory simulations and symmetry analysis, we show that the lead-free perovskite iodide (FA)SnI3, containing the planar formamidinium cation FA, (NH2CHNH2)+, is ferroelectric. In fact, the perpendicular arrangement of FA planes, leading to a ‘weak’ polarization, is energetically more stable than parallel arrangements of FA planes, being either antiferroelectric or ‘strong’ ferroelectric. Moreover, we show that the ‘weak’ and ‘strong’ ferroelectric states with the polar axis along different crystallographic directions are energetically competing. Therefore, at least at low temperatures, an electric field could stabilize different states with the polarization rotated by π/4, resulting in a highly tunable ferroelectricity appealing for multistate logic. Intriguingly, the relatively strong spin-orbit coupling in noncentrosymmetric (FA)SnI3 gives rise to a co-existence of Rashba and Dresselhaus effects and to a spin texture that can be induced, tuned and switched by an electric field controlling the ferroelectric state.

  8. Dimensional crossover of effective orbital dynamics in polar distorted He 3 -A : Transitions to antispacetime

    Science.gov (United States)

    Nissinen, J.; Volovik, G. E.

    2018-01-01

    Topologically protected superfluid phases of He 3 allow one to simulate many important aspects of relativistic quantum field theories and quantum gravity in condensed matter. Here we discuss a topological Lifshitz transition of the effective quantum vacuum in which the determinant of the tetrad field changes sign through a crossing to a vacuum state with a degenerate fermionic metric. Such a transition is realized in polar distorted superfluid He 3 -A in terms of the effective tetrad fields emerging in the vicinity of the superfluid gap nodes: the tetrads of the Weyl points in the chiral A-phase of He 3 and the degenerate tetrad in the vicinity of a Dirac nodal line in the polar phase of He 3 . The continuous phase transition from the A -phase to the polar phase, i.e., the transition from the Weyl nodes to the Dirac nodal line and back, allows one to follow the behavior of the fermionic and bosonic effective actions when the sign of the tetrad determinant changes, and the effective chiral spacetime transforms to antichiral "anti-spacetime." This condensed matter realization demonstrates that while the original fermionic action is analytic across the transition, the effective action for the orbital degrees of freedom (pseudo-EM) fields and gravity have nonanalytic behavior. In particular, the action for the pseudo-EM field in the vacuum with Weyl fermions (A-phase) contains the modulus of the tetrad determinant. In the vacuum with the degenerate metric (polar phase) the nodal line is effectively a family of 2 +1 d Dirac fermion patches, which leads to a non-analytic (B2-E2)3/4 QED action in the vicinity of the Dirac line.

  9. Assessing Sahelian vegetation and stress from seasonal time series of polar orbiting and geostationary satellite imagery

    DEFF Research Database (Denmark)

    Olsen, Jørgen Lundegaard

    that short term variations in anomalies from seasonally detrended time series of indices could carry information on vegetation stress was examined and confirmed. However, it was not found sufficiently robust on pixel level to be implemented for monitoring vegetation water stress on a per-pixel basis...... provide good sensitivity to canopy water content, which can make vegetation stress detection possible. Furthermore, the high frequency observations in the optical spectrum now available from geostationary instruments have the potential for detection of changes in vegetation related surface properties...... on short timescales, which are challenging from polar orbiting instruments. Geostationary NDVI and the NIR and SWIR based Shortwave Infrared Water Stress Index (SIWSI) indices are compared with extensive field data from the Dahra site, supplemented by data from the Agoufou and Demokeya sites. The indices...

  10. Sunlight effects on the 3D polar current system determined from low Earth orbit measurements

    DEFF Research Database (Denmark)

    Laundal, Karl M.; Finlay, Chris; Olsen, Nils

    2016-01-01

    Interaction between the solar wind and the Earth’s magnetosphere is associated with large-scale currents in the ionosphere at polar latitudes that flow along magnetic field lines (Birkeland currents) and horizontally. These current systems are tightly linked, but their global behaviors are rarely...... analyzed together. In this paper, we present estimates of the average global Birkeland currents and horizontal ionospheric currents from the same set of magnetic field measurements. The magnetic field measurements, from the low Earth orbiting Swarm and CHAMP satellites, are used to co-estimate poloidal...... and toroidal parts of the magnetic disturbance field, represented in magnetic apex coordinates. The use of apex coordinates reduces effects of longitudinal and hemispheric variations in the Earth’s main field. We present global currents from both hemispheres during different sunlight conditions. The results...

  11. Explicit polarization (X-Pol) potential using ab initio molecular orbital theory and density functional theory.

    Science.gov (United States)

    Song, Lingchun; Han, Jaebeom; Lin, Yen-lin; Xie, Wangshen; Gao, Jiali

    2009-10-29

    The explicit polarization (X-Pol) method has been examined using ab initio molecular orbital theory and density functional theory. The X-Pol potential was designed to provide a novel theoretical framework for developing next-generation force fields for biomolecular simulations. Importantly, the X-Pol potential is a general method, which can be employed with any level of electronic structure theory. The present study illustrates the implementation of the X-Pol method using ab initio Hartree-Fock theory and hybrid density functional theory. The computational results are illustrated by considering a set of bimolecular complexes of small organic molecules and ions with water. The computed interaction energies and hydrogen bond geometries are in good accord with CCSD(T) calculations and B3LYP/aug-cc-pVDZ optimizations.

  12. Orbits

    CERN Document Server

    Xu, Guochang

    2008-01-01

    This is the first book of the satellite era which describes orbit theory with analytical solutions of the second order with respect to all possible disturbances. Based on such theory, the algorithms of orbits determination are completely revolutionized.

  13. Estimation of land-atmosphere energy transfer over the Tibetan Plateau by a combination use of geostationary and polar-orbiting satellite data

    Science.gov (United States)

    Zhong, L.; Ma, Y.

    2017-12-01

    Land-atmosphere energy transfer is of great importance in land-atmosphere interactions and atmospheric boundary layer processes over the Tibetan Plateau (TP). The energy fluxes have high temporal variability, especially in their diurnal cycle, which cannot be acquired by polar-orbiting satellites alone because of their low temporal resolution. Therefore, it's of great practical significance to retrieve land surface heat fluxes by a combination use of geostationary and polar orbiting satellites. In this study, a time series of the hourly LST was estimated from thermal infrared data acquired by the Chinese geostationary satellite FengYun 2C (FY-2C) over the TP. The split window algorithm (SWA) was optimized using a regression method based on the observations from the Enhanced Observing Period (CEOP) of the Asia-Australia Monsoon Project (CAMP) on the Tibetan Plateau (CAMP/Tibet) and Tibetan observation and research platform (TORP), the land surface emissivity (LSE) from the Moderate Resolution Imaging Spectroradiometer (MODIS), and the water vapor content from the National Centers for Environmental Prediction (NCEP) Climate Forecast System Reanalysis (CFSR) project. The 10-day composite hourly LST data were generated via the maximum value composite (MVC) method to reduce the cloud effects. The derived LST was validated by the field observations of CAMP/Tibet and TORP. The results show that the retrieved LST and in situ data have a very good correlation (with root mean square error (RMSE), mean bias (MB), mean absolute error (MAE) and correlation coefficient (R) values of 1.99 K, 0.83 K, 1.71 K, and 0.991, respectively). Together with other characteristic parameters derived from polar-orbiting satellites and meteorological forcing data, the energy balance budgets have been retrieved finally. The validation results showed there was a good consistency between estimation results and in-situ measurements over the TP, which prove the robustness of the proposed estimation

  14. Orbital

    OpenAIRE

    Yourshaw, Matthew Stephen

    2017-01-01

    Orbital is a virtual reality gaming experience designed to explore the use of traditional narrative structure to enhance immersion in virtual reality. The story structure of Orbital was developed based on the developmental steps of 'The Hero's Journey,' a narrative pattern identified by Joseph Campbell. Using this standard narrative pattern, Orbital is capable of immersing the player quickly and completely for the entirety of play time. MFA

  15. Modification of the method of polarized orbitals for electron--alkali-metal scattering: Application to e-Li

    International Nuclear Information System (INIS)

    Bhatia, A.K.; Temkin, A.; Silver, A.; Sullivan, E.C.

    1978-01-01

    The method of polarized orbitals is modified to treat low-energy scattering of electrons from highly polarizable systems, specifically alkali-metal atoms. The modification is carried out in the particular context of the e-Li system, but the procedure is general; it consists of modifying the polarized orbital, so that when used in the otherwise orthodox form of the method, it gives (i) the correct electron affinity of the negative ion (in this case Li - ), (ii) the proper (i.e., Levinson-Swan) number of nodes of the associated zero-energy scattering orbital, and (iii) the correct polarizability. A procedure is devised whereby the scattering length can be calculated from the (known) electron affinity without solving the bound-state equation. Using this procedure we adduce a 1 S scattering length of 8.69a 0 . (The 3 S scattering length is -9.22a 0 .) The above modifications can also be carried out in the (lesser) exchange adiabatic approximation. However, they lead to qualitatively incorrect 3 S phase shifts. The modified polarized-orbital phase shifts are qualitatively similar to close-coupling and elaborate variational calculations. Quantitative differences from the latter calculations, however, remain; they are manifested most noticeably in the very-low-energy total and differential spin-flip cross sections

  16. Sentinel-5: the new generation European operational atmospheric chemistry mission in polar orbit

    Science.gov (United States)

    Pérez Albiñana, Abelardo; Erdmann, Matthias; Wright, Norrie; Martin, Didier; Melf, Markus; Bartsch, Peter; Seefelder, Wolfgang

    2017-08-01

    Sentinel-5 is an Earth Observation instrument to be flown on the Metop Second Generation (Metop-SG) satellites with the fundamental objective of monitoring atmospheric composition from polar orbit. The Sentinel-5 instrument consists of five spectrometers to measure the solar spectral radiance backscattered by the earth atmosphere in five bands within the UV (270nm) to SWIR (2385nm) spectral range. Data provided by Sentinel-5 will allow obtaining the distribution of important atmospheric constituents such as ozone, on a global daily basis and at a finer spatial resolution than its precursor instruments on the first generation of Metop satellites. The launch of the first Metop-SG satellite is foreseen for 2021. The Sentinel-5 instrument is being developed by Airbus DS under contract to the European Space Agency. The Sentinel-5 mission is part of the Space Component of the Copernicus programme, a joint initiative by ESA, EUMETSAT and the European Commission. The Preliminary Design Review (PDR) for the Sentinel-5 development was successfully completed in 2015. This paper provides a description of the Sentinel-5 instrument design and data calibration.

  17. The Suomi National Polar-Orbiting Partnership (SNPP): Continuing NASA Research and Applications

    Science.gov (United States)

    Butler, James; Gleason, James; Jedlovec, Gary; Coronado, Patrick

    2015-01-01

    The Suomi National Polar-orbiting Partnership (SNPP) satellite was successfully launched into a polar orbit on October 28, 2011 carrying 5 remote sensing instruments designed to provide data to improve weather forecasts and to increase understanding of long-term climate change. SNPP provides operational continuity of satellite-based observations for NOAA's Polar-orbiting Operational Environmental Satellites (POES) and continues the long-term record of climate quality observations established by NASA's Earth Observing System (EOS) satellites. In the 2003 to 2011 pre-launch timeframe, NASA's SNPP Science Team assessed the adequacy of the operational Raw Data Records (RDRs), Sensor Data Records (SDRs), and Environmental Data Records (EDRs) from the SNPP instruments for use in NASA Earth Science research, examined the operational algorithms used to produce those data records, and proposed a path forward for the production of climate quality products from SNPP. In order to perform these tasks, a distributed data system, the NASA Science Data Segment (SDS), ingested RDRs, SDRs, and EDRs from the NOAA Archive and Distribution and Interface Data Processing Segments, ADS and IDPS, respectively. The SDS also obtained operational algorithms for evaluation purposes from the NOAA Government Resource for Algorithm Verification, Independent Testing and Evaluation (GRAVITE). Within the NASA SDS, five Product Evaluation and Test Elements (PEATEs) received, ingested, and stored data and performed NASA's data processing, evaluation, and analysis activities. The distributed nature of this data distribution system was established by physically housing each PEATE within one of five Climate Analysis Research Systems (CARS) located at either at a NASA or a university institution. The CARS were organized around 5 key EDRs directly in support of the following NASA Earth Science focus areas: atmospheric sounding, ocean, land, ozone, and atmospheric composition products. The PEATES provided

  18. Toward a Unified View of the Moon's Polar Volatiles from the Lunar Reconnaissance Orbiter

    Science.gov (United States)

    Hayne, Paul

    2016-04-01

    Although the scientific basis for the possibility of water and other volatiles in the cold traps of the lunar polar regions was developed in the 1960's and '70's [1,2], only recently have the data become available to test the theories in detail. Furthermore, comparisons with other planetary bodies, particularly Mercury, have revealed surprising differences that may point to inconsistencies or holes in our understanding of the basic processes involving volatiles on airless bodies [3]. Addressing these gaps in understanding is critical to the future exploration of the Moon, for which water is an important scientific and engineering resource [4]. Launched in 2009, NASA's Lunar Reconnaissance Orbiter (LRO) has been acquiring data from lunar orbit for more than six years. All seven of the remote sensing instruments on the payload have now contributed significantly to advancing understanding of volatiles on the Moon. Here we present results from these investigations, and discuss attempts to synthesize the disparate information to create a self-consistent model for lunar volatiles. In addition to the LRO data, we must take into account results from earlier missions [5,6], ground-based telescopes [7], and sample analyses [8]. The results from these inter-comparisons show that water is likely available in useful quantities, but key additional measurements may be required to resolve remaining uncertainties. [1] Watson, K., Murray, B. C., & Brown, H. (1961), J. Geophys. Res., 66(9), 3033-3045. [2] Arnold, J. R. (1979), J. Geophys. Res. (1978-2012), 84(B10), 5659-5668. [3] Paige, D. A., Siegler, M. A., Harmon, J. K., Neumann, G. A., Mazarico, E. M., Smith, D. E., ... & Solomon, S. C. (2013), Science, 339(6117), 300-303. [4] Hayne, P. O., et al. (2014), Keck Inst. Space Studies Report. [5] Nozette, S., Lichtenberg, C. L., Spudis, P., Bonner, R., Ort, W., Malaret, E., ... & Shoemaker, E. M. (1996), Science, 274(5292), 1495-1498. [6] Pieters, C. M., Goswami, J. N., Clark, R. N

  19. KEPLER-63b: A GIANT PLANET IN A POLAR ORBIT AROUND A YOUNG SUN-LIKE STAR

    International Nuclear Information System (INIS)

    Sanchis-Ojeda, Roberto; Winn, Joshua N.; Albrecht, Simon; Marcy, Geoffrey W.; Isaacson, Howard; Howard, Andrew W.; Johnson, John Asher; Torres, Guillermo; Carter, Joshua A.; Dawson, Rebekah I.; Geary, John C.; Campante, Tiago L.; Chaplin, William J.; Davies, Guy R.; Lund, Mikkel N.; Buchhave, Lars A.; Everett, Mark E.; Fischer, Debra A.; Gilliland, Ronald L.; Horch, Elliott P.

    2013-01-01

    We present the discovery and characterization of a giant planet orbiting the young Sun-like star Kepler-63 (KOI-63, m Kp = 11.6, T eff = 5576 K, M * = 0.98 M ☉ ). The planet transits every 9.43 days, with apparent depth variations and brightening anomalies caused by large starspots. The planet's radius is 6.1 ± 0.2 R ⊕ , based on the transit light curve and the estimated stellar parameters. The planet's mass could not be measured with the existing radial-velocity data, due to the high level of stellar activity, but if we assume a circular orbit, then we can place a rough upper bound of 120 M ⊕ (3σ). The host star has a high obliquity (ψ = 104°), based on the Rossiter-McLaughlin effect and an analysis of starspot-crossing events. This result is valuable because almost all previous obliquity measurements are for stars with more massive planets and shorter-period orbits. In addition, the polar orbit of the planet combined with an analysis of spot-crossing events reveals a large and persistent polar starspot. Such spots have previously been inferred using Doppler tomography, and predicted in simulations of magnetic activity of young Sun-like stars

  20. KEPLER-63b: A GIANT PLANET IN A POLAR ORBIT AROUND A YOUNG SUN-LIKE STAR

    Energy Technology Data Exchange (ETDEWEB)

    Sanchis-Ojeda, Roberto; Winn, Joshua N.; Albrecht, Simon [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Marcy, Geoffrey W.; Isaacson, Howard [Astronomy Department, University of California, Berkeley, CA 94720 (United States); Howard, Andrew W. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Johnson, John Asher [Department of Astronomy, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Torres, Guillermo; Carter, Joshua A.; Dawson, Rebekah I.; Geary, John C. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Campante, Tiago L.; Chaplin, William J.; Davies, Guy R. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Lund, Mikkel N. [Stellar Astrophysics Centre (SAC), Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Buchhave, Lars A. [Niels Bohr Institute, University of Copenhagen, Juliane Maries vej 30, DK-2100 Copenhagen (Denmark); Everett, Mark E. [National Optical Astronomy Observatory, 950 N. Cherry Ave, Tucson, AZ 85719 (United States); Fischer, Debra A. [Astronomy Department, Yale University, New Haven, CT (United States); Gilliland, Ronald L. [Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Horch, Elliott P. [Southern Connecticut State University, New Haven, CT 06515 (United States); and others

    2013-09-20

    We present the discovery and characterization of a giant planet orbiting the young Sun-like star Kepler-63 (KOI-63, m{sub Kp} = 11.6, T{sub eff} = 5576 K, M{sub *} = 0.98 M{sub ☉}). The planet transits every 9.43 days, with apparent depth variations and brightening anomalies caused by large starspots. The planet's radius is 6.1 ± 0.2 R{sub ⊕}, based on the transit light curve and the estimated stellar parameters. The planet's mass could not be measured with the existing radial-velocity data, due to the high level of stellar activity, but if we assume a circular orbit, then we can place a rough upper bound of 120 M{sub ⊕} (3σ). The host star has a high obliquity (ψ = 104°), based on the Rossiter-McLaughlin effect and an analysis of starspot-crossing events. This result is valuable because almost all previous obliquity measurements are for stars with more massive planets and shorter-period orbits. In addition, the polar orbit of the planet combined with an analysis of spot-crossing events reveals a large and persistent polar starspot. Such spots have previously been inferred using Doppler tomography, and predicted in simulations of magnetic activity of young Sun-like stars.

  1. GeoMapApp as a platform for visualizing marine data from Polar Regions

    Science.gov (United States)

    Nitsche, F. O.; Ryan, W. B.; Carbotte, S. M.; Ferrini, V.; Goodwillie, A. M.; O'hara, S. H.; Weissel, R.; McLain, K.; Chinhong, C.; Arko, R. A.; Chan, S.; Morton, J. J.; Pomeroy, D.

    2012-12-01

    To maximize the investment in expensive fieldwork the resulting data should be re-used as much as possible. In addition, unnecessary duplication of data collection effort should be avoided. This becomes even more important if access to field areas is as difficult and expensive as it is in Polar Regions. Making existing data discoverable in an easy to use platform is key to improve re-use and avoid duplication. A common obstacle is that use of existing data is often limited to specialists who know of the data existence and also have the right tools to view and analyze these data. GeoMapApp is a free, interactive, map based tool that allows users to discover, visualize, and analyze a large number of data sets. In addition to a global view, it provides polar map projections for displaying data in Arctic and Antarctic areas. Data that have currently been added to the system include Arctic swath bathymetry data collected from the USCG icebreaker Healy. These data are collected almost continuously including from cruises where bathymetry is not the main objective and for which existence of the acquired data may not be well known. In contrast, existence of seismic data from the Antarctic continental margin is well known in the seismic community. They are archived at and can be accessed through the Antarctic Seismic Data Library System (SDLS). Incorporating these data into GeoMapApp makes an even broader community aware of these data and the custom interface, which includes capabilities to visualize and explore these data, allows users without specific software or knowledge of the underlying data format to access the data. In addition to investigating these datasets, GeoMapApp provides links to the actual data sources to allow specialists the opportunity to re-use the original data. Important identification of data sources and data references are achieved on different levels. For access to the actual Antarctic seismic data GeoMapApp links to the SDLS site, where users have

  2. Polarization diversity DPSK demodulator on the silicon-on-insulator platform with simple fabrication

    DEFF Research Database (Denmark)

    Ding, Yunhong; Huang, Bo; Ou, Haiyan

    2013-01-01

    of a tapered waveguide followed by a 2 × 2 multimode interferometer. A lowest insertion loss of 0.5 dB with low polarization dependent loss of 1.6 dB and low polarization dependent extinction ratio smaller than 3 dB are measured for the polarization diversity circuit. Clear eye-diagrams and a finite power...

  3. IR detectors for the Infrared Atmospheric Sounding Interferometer (IASI) instrument payload for the METOP-1 ESA polar platform

    Science.gov (United States)

    Royer, Michel; Lorans, Dominique; Bischoff, Isabelle; Giotta, Dominique; Wolny, Michel

    1994-12-01

    IASI is an Infrared Atmospheric Sounding Interferometer devoted to the operational meteorology and to atmospheric studies and is to be installed on board the second ESA Polar Platform called METOP-1, planned to be launched in the year 2000. The main purpose of this high performance instrument is to record temperature and humidity profiles. The required lifetime is 4 years. This paper presents the characteristics of the LW IR detection arrays for the IASI spectrometer which consist of HgCdTe de- tectors. SAT has to develop the Engineering Model, Qualification Model and Fight Models of detectors, each having 4 pixels and AR-coated microlenses in a dedicated space housing equipped with a flexible line and a connector. An array is composed of HgCdTe photoconductive detectors. For this long wavelength the array is sensitive from 8.26 micrometers to 15.5 micrometers . The detectors, with sensitive areas of 900 x 900 micrometers 2, are 100 K operating with passive cooling. High quality HgCdTe material is a key feature for the manufacturing of high performance photoconductive detectors. Therefore epitaxial HgCdTe layers are used in this project. These epilayers are grown at CEA/LETI on lattice matched CdZnTe substrates, by Te-rich liquid phase epitaxy, based on a slider technique. The Cd content in the layer is carefully adjusted to meet the required cut off wavelength on the devices. After growth of the epilayers, the samples are annealed under Hg pressure in order to convert them into N type mate- rials. The electrical transport properties of the liquid phase epitaxied wafers are, at 100 K, mobility (mu) over 150,000 cm2/V.s and electrical concentration N of 1.5 1015 cm-3, the residual doping level being 1014 cm-3 at low temperature. On these materials the feasibility study of long wavelength HgCdTe photoconductors has been achieved with the following results: the responsivity is 330 V/W. The bias voltage is Vp=300 mV for a 4 mW limitation of power for each element. The

  4. Graphene on transition-metal dichalcogenides: a platform for proximity spin-orbit physics and optospintronics

    OpenAIRE

    Gmitra, Martin; Fabian, Jaroslav

    2015-01-01

    Hybrids of graphene and two dimensional transition metal dichalcogenides (TMDC) have the potential to bring graphene spintronics to the next level. As we show here by performing first-principles calculations of graphene on monolayer MoS$_2$, there are several advantages of such hybrids over pristine graphene. First, Dirac electrons in graphene exhibit a giant global proximity spin-orbit coupling, without compromising the semimetallic character of the whole system at zero field. Remarkably, th...

  5. Prototype detector development for measurement of high altitude Martian dust using a future orbiter platform

    Science.gov (United States)

    Pabari, Jayesh; Patel, Darshil; Chokhawala, Vimmi; Bogavelly, Anvesh

    2016-07-01

    Dust devils mostly occur during the mid of Southern hemisphere summer on Mars and play a key role in the background dust opacity. Due to continuous bombardment of micrometeorites, secondary ejecta come out from the Moons of the Mars and can easily escape. This phenomenon can contribute dust around the Moons and therefore, also around the Mars. Similar to the Moons of the Earth, the surfaces of the Martian Moons get charged and cause the dust levitation to occur, adding to the possible dust source. Also, interplanetary dust particles may be able to reach the Mars and contribute further. It is hypothesized that the high altitude Martian dust could be in the form of a ring or tori around the Mars. However, no such rings have been detected to the present day. Typically, width and height of the dust torus is ~5 Mars radii wide (~16950 km) in both the planes as reported in the literature. Recently, very high altitude dust at about 1000 km has been found by MAVEN mission and it is expected that the dust may be concentrated at about 150 to 500 km. However, a langmuir probe cannot explain the source of such dust particles. It is a puzzling question to the space scientist how dust has reached to such high altitudes. A dedicated dust instrument on future Mars orbiter may be helpful to address such issues. To study origin, abundance, distribution and seasonal variation of Martian dust, a Mars Orbit Dust Experiment (MODEX) is proposed. In order to measure the Martian dust from a future orbiter, design of a prototype of an impact ionization dust detector has been initiated at PRL. This paper presents developmental aspects of the prototype dust detector and initial results. The further work is underway.

  6. Chaos and its control in the pitch motion of an asymmetric magnetic spacecraft in polar elliptic orbit

    Energy Technology Data Exchange (ETDEWEB)

    Inarrea, Manuel [Universidad de La Rioja, Area de Fisica Aplicada, 26006 Logrono (Spain)], E-mail: manuel.inarrea@unirioja.es

    2009-05-30

    We study the pitch attitude dynamics of an asymmetric magnetic spacecraft in a polar almost circular orbit under the influence of a gravity gradient torque. The spacecraft is perturbed by the small eccentricity of the elliptic orbit and by a small magnetic torque generated by the interaction between the Earth's magnetic field and the magnetic moment of the spacecraft. Under both perturbations, we show that the pitch motion exhibits heteroclinic chaotic behavior by means of the Melnikov method. Numerical methods applied to simulations of the pitch motion also confirm the chaotic character of the spacecraft attitude dynamics. Finally, a linear time-delay feedback method for controlling chaos is applied to the governing equations of the spacecraft pitch motion in order to remove the chaotic character of initially irregular attitude motions and transform them into periodic ones.

  7. Chaos and its control in the pitch motion of an asymmetric magnetic spacecraft in polar elliptic orbit

    International Nuclear Information System (INIS)

    Inarrea, Manuel

    2009-01-01

    We study the pitch attitude dynamics of an asymmetric magnetic spacecraft in a polar almost circular orbit under the influence of a gravity gradient torque. The spacecraft is perturbed by the small eccentricity of the elliptic orbit and by a small magnetic torque generated by the interaction between the Earth's magnetic field and the magnetic moment of the spacecraft. Under both perturbations, we show that the pitch motion exhibits heteroclinic chaotic behavior by means of the Melnikov method. Numerical methods applied to simulations of the pitch motion also confirm the chaotic character of the spacecraft attitude dynamics. Finally, a linear time-delay feedback method for controlling chaos is applied to the governing equations of the spacecraft pitch motion in order to remove the chaotic character of initially irregular attitude motions and transform them into periodic ones.

  8. Platforms.

    Science.gov (United States)

    Josko, Deborah

    2014-01-01

    The advent of DNA sequencing technologies and the various applications that can be performed will have a dramatic effect on medicine and healthcare in the near future. There are several DNA sequencing platforms available on the market for research and clinical use. Based on the medical laboratory scientist or researcher's needs and taking into consideration laboratory space and budget, one can chose which platform will be beneficial to their institution and their patient population. Although some of the instrument costs seem high, diagnosing a patient quickly and accurately will save hospitals money with fewer hospital stays and targeted treatment based on an individual's genetic make-up. By determining the type of disease an individual has, based on the mutations present or having the ability to prescribe the appropriate antimicrobials based on the knowledge of the organism's resistance patterns, the clinician will be better able to treat and diagnose a patient which ultimately will improve patient outcomes and prognosis.

  9. Dresselhaus spin-orbit coupling induced spin-polarization and resonance-split in n-well semiconductor superlattices

    International Nuclear Information System (INIS)

    Ye Chengzhi; Xue Rui; Nie, Y.-H.; Liang, J.-Q.

    2009-01-01

    Using the transfer matrix method, we investigate the electron transmission over multiple-well semiconductor superlattices with Dresselhaus spin-orbit coupling in the potential-well regions. The superlattice structure enhances the effect of spin polarization in the transmission spectrum. The minibands of multiple-well superlattices for electrons with different spin can be completely separated at the low incident energy, leading to the 100% spin polarization in a broad energy windows, which may be an effective scheme for realizing spin filtering. Moreover, for the transmission over n-quantum-well, it is observed that the resonance peaks in the minibands split into n-folds or (n-1)-folds depending on the well-width and barrier-thickness, which is different from the case of tunneling through n-barrier structure

  10. Integrated Cu-based TM-pass polarizer using CMOS technology platform

    KAUST Repository

    Ng, Tien Khee; Khan, Mohammed Zahed Mustafa; Ooi, Boon S.

    2010-01-01

    A transverse-magnetic-pass (TM-pass) copper (Cu) polarizer is proposed and analyzed using the previously published two-dimensional Method-of-Lines beam-propagation model. The proposed polarizer exhibits a simulated high-pass filter characteristics

  11. Spin-orbit-induced spin splittings in polar transition metal dichalcogenide monolayers

    KAUST Repository

    Cheng, Yingchun; Zhu, Zhiyong; Tahir, Muhammad; Schwingenschlö gl, Udo

    2013-01-01

    . We present ab initio electronic structure, phonon, and molecular-dynamics calculations to study the structural stability and spin-orbit-induced spin splitting in the transition metal dichalcogenide monolayers MXY (M = Mo, W and X, Y = S, Se, Te

  12. Conductance and spin polarization for a quantum wire with the competition of Rashba and Dresselhaus spin-orbit coupling

    International Nuclear Information System (INIS)

    Fu Xi; Chen Zeshun; Zhong Feng; Zhou Guanghui

    2010-01-01

    We investigate theoretically the spin transport of a quantum wire (QW) with weak Rashba and Dresselhaus spin-orbit coupling (SOC) nonadiabatically connected to two normal leads. Using scattering matrix method and Landauer-Buettiker formula within effective free-electron approximation, we have calculated spin-dependent conductances G ↑ and G ↓ , total conductance G and spin polarization P z for a hard-wall potential confined QW. It is demonstrated that, the SOCs induce the splitting of G ↑ and G ↓ and form spin polarization P z . Moreover, the conductances present quantized plateaus, the plateaus and P z show oscillation structures near the subband edges. Furthermore, with the increase of QW width a strong spin polarization (P z ∼1) gradually becomes weak, which can be used to realize a spin filter. When the two SOCs coexist, the total conductance presents an isotropy transport due to the Rashba and Dresselhaus Hamiltonians being fixed, and the alteration of two SOCs strength ratio changes the sign of spin polarization. This may provide a way of realizing the expression of unit information by tuning gate voltage.

  13. Effect of Rashba and Dresselhaus Spin-Orbit Couplings on Electron Spin Polarization in a Hybrid Magnetic-Electric Barrier Nanostructure

    Science.gov (United States)

    Yang, Shi-Peng; Lu, Mao-Wang; Huang, Xin-Hong; Tang, Qiang; Zhou, Yong-Long

    2017-04-01

    A theoretical study has been carried out on the spin-dependent electron transport in a hybrid magnetic-electric barrier nanostructure with both Rashba and Dresselhaus spin-orbit couplings, which can be experimentally realized by depositing a ferromagnetic strip and a Schottky metal strip on top of a semiconductor heterostructure. The spin-orbit coupling-dependent transmission coefficient, conductance, and spin polarization are calculated by solving the Schrödinger equation exactly with the help of the transfer-matrix method. We find that both the magnitude and sign of the electron spin polarization vary strongly with the spin-orbit coupling strength. Thus, the degree of electron spin polarization can be manipulated by properly adjusting the spin-orbit coupling strength, and such a nanosystem can be employed as a controllable spin filter for spintronics applications.

  14. Creating intense polarized electron beam via laser stripping and spin-orbit interaction

    International Nuclear Information System (INIS)

    Danilov, V.; Ptitsyn, V.; Gorlov, T.

    2010-01-01

    The recent advance in laser field make it possible to excite and strip electrons with definite spin from hydrogen atoms. The sources of hydrogen atoms with orders of magnitude higher currents (than that of the conventional polarized electron cathods) can be obtained from H - sources with good monochromatization. With one electron of H - stripped by a laser, the remained electron is excited to upper state (2P 3/2 and 2P 1/2 ) by a circular polarization laser light from FEL. Then, it is excited to a high quantum number (n=7) with mostly one spin direction due to energy level split of the states with a definite direction of spin and angular momentum in an applied magnetic field and then it is stripped by a strong electric field of an RF cavity. This paper presents combination of lasers and fields to get high polarization and high current electron source.

  15. Jupiter's magnetosphere and aurorae observed by the Juno spacecraft during its first polar orbits

    DEFF Research Database (Denmark)

    Connerney, J. E. P.; Adriani, Alberto; Allegrini, F.

    2017-01-01

    The Juno spacecraft acquired direct observations of the jovian magnetosphere and auroral emissions from a vantage point above the poles. Juno's capture orbit spanned the jovian magnetosphere from bow shock to the planet, providing magnetic field, charged particle, and wave phenomena context...

  16. Mitigating the Effect of an Orbit Kink on Vertical Emittance and Polarization

    CERN Document Server

    Koop, I

    2015-01-01

    Orbit kinks in FCC tunnel are under discussions for they can help to reduce the depth of few shafts [1]. Still two unwanted effects could make their use completely forbidden. The vertical emittance growth due to vertical bending and vertical dispersion is one of these concerns [2]. Another concern is the need to somehow compensate strong distortions of spin motion [3]. Here I present an idea of how we can simultaneously solve both these problems.

  17. Differential roles of polar orbital prefrontal cortex and parietal lobes in logical reasoning with neutral and negative emotional content.

    Science.gov (United States)

    Eimontaite, Iveta; Goel, Vinod; Raymont, Vanessa; Krueger, Frank; Schindler, Igor; Grafman, Jordan

    2018-05-14

    To answer the question of how brain pathology affects reasoning about negative emotional content, we administered a disjunctive logical reasoning task involving arguments with neutral content (e.g. Either there are tigers or women in NYC, but not both; There are no tigers in NYC; There are women in NYC) and emotionally laden content (e.g. Either there are pedophiles or politicians in Texas, but not both; There are politicians in Texas; There are no pedophiles in Texas) to 92 neurological patients with focal lesions to various parts of the brain. A Voxel Lesion Symptom Mapping (VLSM) analysis identified 16 patients, all with lesions to the orbital polar prefrontal cortex (BA 10 & 11), as being selectively impaired in the emotional reasoning condition. Another 17 patients, all with lesions to the parietal cortex, were identified as being impaired in the neutral content condition. The reasoning scores of these two patient groups, along with 23 matched normal controls, underwent additional analysis to explore the effect of belief bias. This analysis revealed that the differences identified above were largely driven by trials where there was an incongruency between the believability of the conclusion and the validity of the argument (i.e. valid argument /false conclusion or invalid argument /true conclusion). Patients with lesions to polar orbital prefrontal cortex underperformed in incongruent emotional content trials and over performed in incongruent neutral content trials (compared to both normal controls and patients with parietal lobe lesions). Patients with lesions to parietal lobes underperformed normal controls (at a trend level) in neutral trials where there was a congruency between the believability of the conclusion and the validity of the argument (i.e. valid argument/true conclusion or invalid argument/false conclusion). We conclude that lesions to the polar orbital prefrontal cortex (i) prevent these patients from enjoying any emotionally induced cognitive

  18. Mechanically Reconfigurable Single-Arm Spiral Antenna Array for Generation of Broadband Circularly Polarized Orbital Angular Momentum Vortex Waves.

    Science.gov (United States)

    Li, Long; Zhou, Xiaoxiao

    2018-03-23

    In this paper, a mechanically reconfigurable circular array with single-arm spiral antennas (SASAs) is designed, fabricated, and experimentally demonstrated to generate broadband circularly polarized orbital angular momentum (OAM) vortex waves in radio frequency domain. With the symmetrical and broadband properties of single-arm spiral antennas, the vortex waves with different OAM modes can be mechanically reconfigurable generated in a wide band from 3.4 GHz to 4.7 GHz. The prototype of the circular array is proposed, conducted, and fabricated to validate the theoretical analysis. The simulated and experimental results verify that different OAM modes can be effectively generated by rotating the spiral arms of single-arm spiral antennas with corresponding degrees, which greatly simplify the feeding network. The proposed method paves a reconfigurable way to generate multiple OAM vortex waves with spin angular momentum (SAM) in radio and microwave satellite communication applications.

  19. Spin Polarization Oscillations without Spin Precession: Spin-Orbit Entangled Resonances in Quasi-One-Dimensional Spin Transport

    Directory of Open Access Journals (Sweden)

    D. H. Berman

    2014-03-01

    Full Text Available Resonant behavior involving spin-orbit entangled states occurs for spin transport along a narrow channel defined in a two-dimensional electron gas, including an apparent rapid relaxation of the spin polarization for special values of the channel width and applied magnetic field (so-called ballistic spin resonance. A fully quantum-mechanical theory for transport using multiple subbands of the one-dimensional system provides the dependence of the spin density on the applied magnetic field and channel width and position along the channel. We show how the spatially nonoscillating part of the spin density vanishes when the Zeeman energy matches the subband energy splittings. The resonance phenomenon persists in the presence of disorder.

  20. Review of a relativity and geodesy mission with counter-orbiting polar satellites

    International Nuclear Information System (INIS)

    Van Patten, R.A.

    1977-01-01

    A new test of general relativity, capable of measuring the Lense-Thirring precession on a satellite orbit was proposed in 1974. We have recently realized that the remarkable geophysical output of this experiment can be enriched by allowing the point of encounter between the two satellites to progress from the poles to the equator during the course of the mission. There is reason to believe that by performing the experiment in this mode, all tesseral harmonics up to about 60th order could be separated and determined to accuracies up to three orders of magnitude better than current knowledge, and still obtain a 1% Lense-Thirring measurement. (orig.) [de

  1. Effect of Orbital Hybridization on Spin-Polarized Tunneling across Co/C60 Interfaces.

    Science.gov (United States)

    Wang, Kai; Strambini, Elia; Sanderink, Johnny G M; Bolhuis, Thijs; van der Wiel, Wilfred G; de Jong, Michel P

    2016-10-26

    The interaction between ferromagnetic surfaces and organic semiconductors leads to the formation of hybrid interfacial states. As a consequence, the local magnetic moment is altered, a hybrid interfacial density of states (DOS) is formed, and spin-dependent shifts of energy levels occur. Here, we show that this hybridization affects spin transport across the interface significantly. We report spin-dependent electronic transport measurements for tunnel junctions comprising C 60 molecular thin films grown on top of face-centered-cubic (fcc) epitaxial Co electrodes, an AlO x tunnel barrier, and an Al counter electrode. Since only one ferromagnetic electrode (Co) is present, spin-polarized transport is due to tunneling anisotropic magnetoresistance (TAMR). An in-plane TAMR ratio of approximately 0.7% has been measured at 5 K under application of a magnetic field of 800 mT. The magnetic switching behavior shows some remarkable features, which are attributed to the rotation of interfacial magnetic moments. This behavior can be ascribed to the magnetic coupling between the Co thin films and the newly formed Co/C 60 hybridized interfacial states. Using the Tedrow-Meservey technique, the tunnel spin polarization of the Co/C 60 interface was found to be 43%.

  2. Mineralogy and Iron Content of the Lunar Polar Regions Using the Kaguya Spectral Profiler and the Lunar Orbiter Laser Altimeter

    Science.gov (United States)

    Lemelin, M.; Lucey, P. G.; Trang, D.; Jha, K.

    2016-12-01

    The lunar polar regions are of high scientific interest, but the extreme lighting conditions have made quantitative analyses using reflectance spectra difficult; some regions are in permanent shadow, and flat surfaces are difficult to correct photometrically due to the extreme grazing incidence and low signal available. Thus, most mineral maps derived from visible and near infrared reflectance spectra have been constrained to within 50° in latitude. The mineralogy of the polar regions, or 44% of the lunar surface, is almost entirely unknown. A few studies have provided compositional analysis based on the spectral shape (where strong absorption bands were present) of lithologies dominated by one or two minerals. In this study, we take a novel approach and use strong signal and well-calibrated reflectance acquired by two different instruments, the Kaguya Spectra Profiler (SP) and the Lunar Orbiter Laser Altimeter (LOLA), in order to derive the first FeO and mineral maps of the polar regions at a spatial resolution of 1 km per pixel. We use reflectance ratios from SP and calibrated reflectance data from LOLA to derive the first polar maps of FeO, which are within 2 wt.% of the FeO measured by the Lunar Prospector Gamma-Ray spectrometer up to 85° in latitude. We then use the reflectance data from SP and Hapke radiative transfer model to compute the abundance of olivine, low-calcium pyroxene, high-calcium pyroxene and plagioclase, using FeO as a constraint. The radiative transfer model yields an error in mineral abundances of 9 wt.%. We use the mineral maps to study the composition of 27 central peaks and 5 basin rings in the polar regions, and relate their composition to their depth of origin in the lunar crust. We find that the central peaks and basin rings in Feldspathic Highlands Terrane are mostly anorthositic in composition, with modal plagioclase content ranging between 66 and 92 wt.%. The central peaks and basin rings in the South Pole-Aitken basin are noritic

  3. Spin polarization, orbital occupation and band gap opening in vanadium dioxide: The effect of screened Hartree-Fock exchange

    KAUST Repository

    Wang, Hao

    2014-07-01

    The metal-insulator transition of VO2 so far has evaded an accurate description by density functional theory. The screened hybrid functional of Heyd, Scuseria and Ernzerhof leads to reasonable solutions for both the low-temperature monoclinic and high-temperature rutile phases only if spin polarization is excluded from the calculations. We explore whether a satisfactory agreement with experiment can be achieved by tuning the fraction of Hartree Fock exchange (α) in the density functional. It is found that two branches of locally stable solutions exist for the rutile phase for 12.5%≤α≤20%. One is metallic and has the correct stability as compared to the monoclinic phase, the other is insulating with lower energy than the metallic branch. We discuss these observations based on the V 3d orbital occupations and conclude that α=10% is the best possible choice for spin-polarized VO2 calculations. © 2014 Elsevier B.V. All rights reserved.

  4. A Dual Polarization, Active, Microstrip Antenna for an Orbital Imaging Radar System Operating at L-Band

    Science.gov (United States)

    Kelly, Kenneth C.; Huang, John

    2000-01-01

    A highly successful Earth orbiting synthetic antenna aperture radar (SAR) system, known as the SIR-C mission, was carried into orbit in 1994 on a U.S. Shuttle (Space Transportation System) mission. The radar system was mounted in the cargo bay with no need to fold, or in any other way reduce the size of the antennas for launch. Weight and size were not limited for the L-Band, C-Band, and X-Band radar systems of the SIR-C radar imaging mission; the set of antennas weighed 10,500 kg, the L-Band antenna having the major share of the weight. This paper treats designing an L-Band antenna functionally similar to that used for SIR-C, but at a fraction of the cost and at a weight in the order of 250 kg. Further, the antenna must be folded to fit into the small payload shroud of low cost booster rocket systems. Over 31 square meters of antenna area is required. This low weight, foldable, electronic scanning antenna is for the proposed LightSAR radar system which is to be placed in Earth orbit on a small, dedicated space craft at the lowest possible cost for an efficient L- Band radar imaging system. This LightSAR spacecraft radar is to be continuously available for at least five operational years, and have the ability to map or repeat-map any area on earth within a few days of any request. A microstrip patch array, with microstrip transmission lines heavily employed in the aperture and in the corporate feed network, was chosen as the low cost approach for this active dual-polarization, 80 MHz (6.4%) bandwidth antenna design.

  5. Giant Optical Polarization Rotation Induced by Spin-Orbit Coupling in Polarons

    Science.gov (United States)

    Casals, Blai; Cichelero, Rafael; García Fernández, Pablo; Junquera, Javier; Pesquera, David; Campoy-Quiles, Mariano; Infante, Ingrid C.; Sánchez, Florencio; Fontcuberta, Josep; Herranz, Gervasi

    2016-07-01

    We have uncovered a giant gyrotropic magneto-optical response for doped ferromagnetic manganite La2 /3Ca1 /3MnO3 around the near room-temperature paramagnetic-to-ferromagnetic transition. At odds with current wisdom, where this response is usually assumed to be fundamentally fixed by the electronic band structure, we point to the presence of small polarons as the driving force for this unexpected phenomenon. We explain the observed properties by the intricate interplay of mobility, Jahn-Teller effect, and spin-orbit coupling of small polarons. As magnetic polarons are ubiquitously inherent to many strongly correlated systems, our results provide an original, general pathway towards the generation of magnetic-responsive gigantic gyrotropic responses that may open novel avenues for magnetoelectric coupling beyond the conventional modulation of magnetization.

  6. Useful lower limits to polarization contributions to intermolecular interactions using a minimal basis of localized orthogonal orbitals: theory and analysis of the water dimer.

    Science.gov (United States)

    Azar, R Julian; Horn, Paul Richard; Sundstrom, Eric Jon; Head-Gordon, Martin

    2013-02-28

    The problem of describing the energy-lowering associated with polarization of interacting molecules is considered in the overlapping regime for self-consistent field wavefunctions. The existing approach of solving for absolutely localized molecular orbital (ALMO) coefficients that are block-diagonal in the fragments is shown based on formal grounds and practical calculations to often overestimate the strength of polarization effects. A new approach using a minimal basis of polarized orthogonal local MOs (polMOs) is developed as an alternative. The polMO basis is minimal in the sense that one polarization function is provided for each unpolarized orbital that is occupied; such an approach is exact in second-order perturbation theory. Based on formal grounds and practical calculations, the polMO approach is shown to underestimate the strength of polarization effects. In contrast to the ALMO method, however, the polMO approach yields results that are very stable to improvements in the underlying AO basis expansion. Combining the ALMO and polMO approaches allows an estimate of the range of energy-lowering due to polarization. Extensive numerical calculations on the water dimer using a large range of basis sets with Hartree-Fock theory and a variety of different density functionals illustrate the key considerations. Results are also presented for the polarization-dominated Na(+)CH4 complex. Implications for energy decomposition analysis of intermolecular interactions are discussed.

  7. Cloud-based opportunities in scientific computing: insights from processing Suomi National Polar-Orbiting Partnership (S-NPP) Direct Broadcast data

    Science.gov (United States)

    Evans, J. D.; Hao, W.; Chettri, S.

    2013-12-01

    The cloud is proving to be a uniquely promising platform for scientific computing. Our experience with processing satellite data using Amazon Web Services highlights several opportunities for enhanced performance, flexibility, and cost effectiveness in the cloud relative to traditional computing -- for example: - Direct readout from a polar-orbiting satellite such as the Suomi National Polar-Orbiting Partnership (S-NPP) requires bursts of processing a few times a day, separated by quiet periods when the satellite is out of receiving range. In the cloud, by starting and stopping virtual machines in minutes, we can marshal significant computing resources quickly when needed, but not pay for them when not needed. To take advantage of this capability, we are automating a data-driven approach to the management of cloud computing resources, in which new data availability triggers the creation of new virtual machines (of variable size and processing power) which last only until the processing workflow is complete. - 'Spot instances' are virtual machines that run as long as one's asking price is higher than the provider's variable spot price. Spot instances can greatly reduce the cost of computing -- for software systems that are engineered to withstand unpredictable interruptions in service (as occurs when a spot price exceeds the asking price). We are implementing an approach to workflow management that allows data processing workflows to resume with minimal delays after temporary spot price spikes. This will allow systems to take full advantage of variably-priced 'utility computing.' - Thanks to virtual machine images, we can easily launch multiple, identical machines differentiated only by 'user data' containing individualized instructions (e.g., to fetch particular datasets or to perform certain workflows or algorithms) This is particularly useful when (as is the case with S-NPP data) we need to launch many very similar machines to process an unpredictable number of

  8. Monitoring volcanic ash cloud top height through simultaneous retrieval of optical data from polar orbiting and geostationary satellites

    Directory of Open Access Journals (Sweden)

    K. Zakšek

    2013-03-01

    Full Text Available Volcanic ash cloud-top height (ACTH can be monitored on the global level using satellite remote sensing. Here we propose a photogrammetric method based on the parallax between data retrieved from geostationary and polar orbiting satellites to overcome some limitations of the existing methods of ACTH retrieval. SEVIRI HRV band and MODIS band 1 are a good choice because of their high resolution. The procedure works well if the data from both satellites are retrieved nearly simultaneously. MODIS does not retrieve the data at exactly the same time as SEVIRI. To compensate for advection we use two sequential SEVIRI images (one before and one after the MODIS retrieval and interpolate the cloud position from SEVIRI data to the time of MODIS retrieval. The proposed method was tested for the case of the Eyjafjallajökull eruption in April 2010. The parallax between MODIS and SEVIRI data can reach 30 km, which implies an ACTH of approximately 12 km at the beginning of the eruption. At the end of April eruption an ACTH of 3–4 km is observed. The accuracy of ACTH was estimated to be 0.6 km.

  9. Detection of Earth-rotation Doppler shift from Suomi National Polar-Orbiting Partnership Cross-Track Infrared Sounder.

    Science.gov (United States)

    Chen, Yong; Han, Yong; Weng, Fuzhong

    2013-09-01

    The Cross-Track Infrared Sounder (CrIS) on the Suomi National Polar-Orbiting Partnership Satellite is a Fourier transform spectrometer and provides a total of 1305 channels for sounding the atmosphere. Quantifying the CrIS spectral accuracy, which is directly related to radiometric accuracy, is crucial for improving its data assimilation in numerical weather prediction. In this study, a cross-correlation method is used for detecting the effect of Earth-rotation Doppler shift (ERDS) on CrIS observations. Based on a theoretical calculation, the ERDS can be as large as about 1.3 parts in 10(6) (ppm) near Earth's equator and at the satellite scan edge for a field of regard (FOR) of 1 or 30. The CrIS observations exhibit a relative Doppler shift as large as 2.6 ppm for a FOR pair of 1 and 30 near the equator. The variation of the ERDS with latitude and scan position detected from CrIS observations is similar to that derived theoretically, which indicates that the spectral stability of the CrIS instrument is very high. To accurately calibrate CrIS spectral accuracy, the ERDS effect should be removed. Since the ERDS is easily predictable, the Doppler shift is correctable in the CrIS spectra.

  10. Reanalyses of the radiation belt electron phase space density using nearly equatorial CRRES and polar-orbiting Akebono satellite observations

    Science.gov (United States)

    Ni, Binbin; Shprits, Yuri; Nagai, Tsugunobu; Thorne, Richard; Chen, Yue; Kondrashov, Dmitri; Kim, Hee-jeong

    2009-05-01

    Data assimilation techniques provide algorithms that allow for blending of incomplete and inaccurate data with physics-based dynamic models to reconstruct the electron phase space density (PSD) in the radiation belts. In this study, we perform reanalyses of the radial PSD profile using two independent data sources from the nearly equatorial CRRES Medium Electron A (MEA) observations and the polar-orbiting Akebono Radiation Monitor (RDM) measurements for a 50-day period from 18 August to 6 October 1990. We utilize the University of California, Los Angeles, One-Dimensional Versatile Electron Radiation Belt (UCLA 1-D VERB) code and a Kalman filtering approach. Comparison of the reanalyses obtained independently using the CRRES MEA and Akebono RDM measurements shows that the dynamics of the PSD can be accurately reconstructed using Kalman filtering even when available data are sparse, inaccurate, and contaminated by random errors. The reanalyses exhibit similarities in the locations and magnitudes of peaks in radial profiles of PSD and the rate and radial extent of the dropouts during storms. This study shows that when unidirectional data are not available, pitch angle averaged flux measurements can be used to infer the long-term behavior (climatology) of the radiation belts. The methodology of obtaining PSD from pitch angle averaged and unidirectional fluxes using the Tsyganenko and Stern (1996) magnetic field model is described in detail.

  11. Asynchronous Processing of a Constellation of Geostationary and Polar-Orbiting Satellites for Fire Detection and Smoke Estimation

    Science.gov (United States)

    Hyer, E. J.; Peterson, D. A.; Curtis, C. A.; Schmidt, C. C.; Hoffman, J.; Prins, E. M.

    2014-12-01

    The Fire Locating and Monitoring of Burning Emissions (FLAMBE) system converts satellite observations of thermally anomalous pixels into spatially and temporally continuous estimates of smoke release from open biomass burning. This system currently processes data from a constellation of 5 geostationary and 2 polar-orbiting sensors. Additional sensors, including NPP VIIRS and the imager on the Korea COMS-1 geostationary satellite, will soon be added. This constellation experiences schedule changes and outages of various durations, making the set of available scenes for fire detection highly variable on an hourly and daily basis. Adding to the complexity, the latency of the satellite data is variable between and within sensors. FLAMBE shares with many fire detection systems the goal of detecting as many fires as possible as early as possible, but the FLAMBE system must also produce a consistent estimate of smoke production with minimal artifacts from the changing constellation. To achieve this, NRL has developed a system of asynchronous processing and cross-calibration that permits satellite data to be used as it arrives, while preserving the consistency of the smoke emission estimates. This talk describes the asynchronous data ingest methodology, including latency statistics for the constellation. We also provide an overview and show results from the system we have developed to normalize multi-sensor fire detection for consistency.

  12. Perfect tuning of spin-polarization in a ring-shaped multiple-quantum-dot nanostructure in the presence of Rashba spin–orbit coupling

    Energy Technology Data Exchange (ETDEWEB)

    Eslami, L., E-mail: Leslami@iust.ac.ir; Chaghari, Z.; Faizabadi, E.

    2013-09-02

    Spin-dependent electronic transport through an open multiple-quantum-dot ring threaded by a magnetic flux is theoretically investigated by using the single particle Green's function method. By introducing local Rashba spin–orbit interaction on an individual quantum dot and local magnetic moments on two of other quantum dots, we calculate the spin-polarization in the output lead. We find the spin-polarization can be tuned by manipulating magnetic moments, adjusting magnetic flux and setting the Rashba spin–orbit strength. It is also shown the system can operate as an efficient spin-inverter when the structure is adjusted properly. The analysis can be utilized in designing optimized nanodevices.

  13. A Lookup-Table-Based Approach to Estimating Surface Solar Irradiance from Geostationary and Polar-Orbiting Satellite Data

    Directory of Open Access Journals (Sweden)

    Hailong Zhang

    2018-03-01

    Full Text Available Incoming surface solar irradiance (SSI is essential for calculating Earth’s surface radiation budget and is a key parameter for terrestrial ecological modeling and climate change research. Remote sensing images from geostationary and polar-orbiting satellites provide an opportunity for SSI estimation through directly retrieving atmospheric and land-surface parameters. This paper presents a new scheme for estimating SSI from the visible and infrared channels of geostationary meteorological and polar-orbiting satellite data. Aerosol optical thickness and cloud microphysical parameters were retrieved from Geostationary Operational Environmental Satellite (GOES system images by interpolating lookup tables of clear and cloudy skies, respectively. SSI was estimated using pre-calculated offline lookup tables with different atmospheric input data of clear and cloudy skies. The lookup tables were created via the comprehensive radiative transfer model, Santa Barbara Discrete Ordinate Radiative Transfer (SBDART, to balance computational efficiency and accuracy. The atmospheric attenuation effects considered in our approach were water vapor absorption and aerosol extinction for clear skies, while cloud parameters were the only atmospheric input for cloudy-sky SSI estimation. The approach was validated using one-year pyranometer measurements from seven stations in the SURFRAD (SURFace RADiation budget network. The results of the comparison for 2012 showed that the estimated SSI agreed with ground measurements with correlation coefficients of 0.94, 0.69, and 0.89 with a bias of 26.4 W/m2, −5.9 W/m2, and 14.9 W/m2 for clear-sky, cloudy-sky, and all-sky conditions, respectively. The overall root mean square error (RMSE of instantaneous SSI was 80.0 W/m2 (16.8%, 127.6 W/m2 (55.1%, and 99.5 W/m2 (25.5% for clear-sky, cloudy-sky (overcast sky and partly cloudy sky, and all-sky (clear-sky and cloudy-sky conditions, respectively. A comparison with other state

  14. Estimation and Validation of Land Surface Temperatures from Chinese Second-Generation Polar-Orbit FY-3A VIRR Data

    Directory of Open Access Journals (Sweden)

    Bo-Hui Tang

    2015-03-01

    Full Text Available This work estimated and validated the land surface temperature (LST from thermal-infrared Channels 4 (10.8 µm and 5 (12.0 µm of the Visible and Infrared Radiometer (VIRR onboard the second-generation Chinese polar-orbiting FengYun-3A (FY-3A meteorological satellite. The LST, mean emissivity and atmospheric water vapor content (WVC were divided into several tractable sub-ranges with little overlap to improve the fitting accuracy. The experimental results showed that the root mean square errors (RMSEs were proportional to the viewing zenith angles (VZAs and WVC. The RMSEs were below 1.0 K for VZA sub-ranges less than 30° or for VZA sub-ranges less than 60° and WVC less than 3.5 g/cm2, provided that the land surface emissivities were known. A preliminary validation using independently simulated data showed that the estimated LSTs were quite consistent with the actual inputs, with a maximum RMSE below 1 K for all VZAs. An inter-comparison using the Moderate Resolution Imaging Spectroradiometer (MODIS-derived LST product MOD11_L2 showed that the minimum RMSE was 1.68 K for grass, and the maximum RMSE was 3.59 K for barren or sparsely vegetated surfaces. In situ measurements at the Hailar field site in northeastern China from October, 2013, to September, 2014, were used to validate the proposed method. The result showed that the RMSE between the LSTs calculated from the ground measurements and derived from the VIRR data was 1.82 K.

  15. The effects of Rashba spin-orbit coupling on spin-polarized transport in hexagonal graphene nano-rings and flakes

    Science.gov (United States)

    Laghaei, M.; Heidari Semiromi, E.

    2018-03-01

    Quantum transport properties and spin polarization in hexagonal graphene nanostructures with zigzag edges and different sizes were investigated in the presence of Rashba spin-orbit interaction (RSOI). The nanostructure was considered as a channel to which two semi-infinite armchair graphene nanoribbons were coupled as input and output leads. Spin transmission and spin polarization in x, y, and z directions were calculated through applying Landauer-Buttiker formalism with tight binding model and the Green's function to the system. In these quantum structures it is shown that changing the size of system, induce and control the spin polarized currents. In short, these graphene systems are typical candidates for electrical spintronic devices as spin filtering.

  16. Realization of an ultra-compact polarization beam splitter using asymmetric MMI based on silicon nitride / silicon-on-insulator platform.

    Science.gov (United States)

    Sun, Xiao; Aitchison, J Stewart; Mojahedi, Mo

    2017-04-03

    We have experimentally demonstrated a compact polarization beam splitter (PBS) based on the silicon nitride/silicon-on-insulator platform using the recently proposed augmented-low-index-guiding (ALIG) waveguide structure. The two orthogonal polarizations are split in an asymmetric multimode interference (MMI) section, which was 1.6 μm wide and 4.8 μm long. The device works well over the entire C-band wavelength range and has a measured low insertion loss of less than 1 dB. The polarization extinction ratio at the Bar Port is approximately 17 dB and at the Cross Port is approximately 25 dB. The design of the device is robust and has a good fabrication tolerance.

  17. Spin-polarization and spin-flip in a triple-quantum-dot ring by using tunable lateral bias voltage and Rashba spin-orbit interaction

    Energy Technology Data Exchange (ETDEWEB)

    Molavi, Mohamad, E-mail: Mo_molavi@yahoo.com [Faculty of Physics, Kharazmi University, Tehran (Iran, Islamic Republic of); Faizabadi, Edris, E-mail: Edris@iust.ac.ir [School of Physics, Iran University of Science and Technology, 16846 Tehran (Iran, Islamic Republic of)

    2017-04-15

    By using the Green's function formalism, we investigate the effects of single particle energy levels of a quantum dot on the spin-dependent transmission properties through a triple-quantum-dot ring structure. In this structure, one of the quantum dots has been regarded to be non-magnetic and the Rashba spin-orbit interaction is imposed locally on this dot while the two others can be magnetic. The on-site energy of dots, manipulates the interference of the electron spinors that are transmitted to output leads. Our results show that the effects of magnetic dots on spin-dependent transmission properties are the same as the difference of on-site energies of the various dots, which is applicable by a controllable lateral bias voltage externally. Besides, by tuning the parameters such as Rashba spin-orbit interaction, and on-site energy of dots and magnetic flux inside the ring, the structure can be indicated the spin-flip effect and behave as a full spin polarizer or splitter. - Highlights: • The effects of magnetic dots on spin-dependent transmission properties are the same as the difference of on-site energies of the various dots. • In the situation that the QDs have non-zero on-site energies, the system can demonstrate the full spin-polarization. • By tuning the Rashba spin-orbit strength and magnetic flux encountered by the ring the system operates as a Stern-Gerlach apparatus.

  18. Energy spectrum, the spin polarization, and the optical selection rules of the Kronig-Penney superlattice model with spin-orbit coupling

    Science.gov (United States)

    Li, Rui

    2018-02-01

    The Kronig-Penney model, an exactly solvable one-dimensional model of crystal in solid physics, shows how the allowed and forbidden bands are formed in solids. In this paper, we study this model in the presence of both strong spin-orbit coupling and the Zeeman field. We analytically obtain four transcendental equations that represent an implicit relation between the energy and the Bloch wave vector. Solving these four transcendental equations, we obtain the spin-orbital bands exactly. In addition to the usual band gap opened at the boundary of the Brillouin zone, a much larger spin-orbital band gap is also opened at some special sites inside the Brillouin zone. The x component of the spin-polarization vector is an even function of the Bloch wave vector, while the z component of the spin-polarization vector is an odd function of the Bloch wave vector. At the band edges, the optical transition rates between adjacent bands are nonzero.

  19. Mid-Latitude versus Polar-Latitude Transitional Impact Craters: Geometric Properties from Mars Orbiter Laser Altimeter (MOLA) Observations and Viking Images

    Science.gov (United States)

    Matias, A.; Garvin, J. B.; Sakimoto, S. E. H.

    1998-01-01

    One intriguing aspect of martian impact crater morphology is the change of crater cavity and ejecta characteristics from the mid-latitudes to the polar regions. This is thought to reflect differences in target properties such as an increasing presence of ice in the polar regions. Previous image-based efforts concerning martian crater morphology has documented some aspects of this, but has been hampered by the lack of adequate topography data. Recent Mars Orbiter Laser Altimeter (MOLA) topographic profiles provide a quantitative perspective for interpreting the detailed morphologies of martian crater cavities and ejecta morphology. This study is a preliminary effort to quantify the latitude-dependent differences in morphology with the goal of identifying target-dependent and crater modification effects from the combined of images and MOLA topography. We combine the available MOLA profiles and the corresponding Viking Mars Digital Image Mosaics (MDIMS), and high resolution Viking Orbiter images to focus on two transitional craters; one on the mid-latitudes, and one in the North Polar region. One MOLA pass (MGS Orbit 34) traverses the center of a 15.9 km diameter fresh complex crater located at 12.8degN 83.8degE on the Hesperian ridge plains unit (Hvr). Viking images, as well as MOLA data, show that this crater has well developed wall terraces and a central peak with 429 m of relative relief. Three MOLA passes have been acquired for a second impact crater, which is located at 69.5degN 41degE on the Vastitas Borealis Formation. This fresh rampart crater lacks terraces and central peak structures and it has a depth af 579 m. Correlation between images and MOLA topographic profiles allows us to construct basic facies maps of the craters. Eight main units were identified, four of which are common on both craters.

  20. From the Orbital Implementation of the Kinetic Theory to the Polarization Propagator Method in the Study of Energy Deposition Problems

    Science.gov (United States)

    Cabrera-Trujillo, R.; Cruz, S. A.; Soullard, J.

    The energy deposited by swift atomic-ion projectiles when colliding with a given target material has been a topic of special scientific interest for the last century due to the variety of applications of ion beams in modern materials technology as well as in medical physics. In this work, we summarize our contributions in this field as a consequence of fruitful discussions and enlightening ideas put forward by one of the main protagonists in stopping power theory during the last three decades: Jens Oddershede. Our review, mainly motivated by Jens' work, evolves from the extension of the orbital implementation of the kinetic theory of stopping through the orbital local plasma approximation, its use in studies of orbital and total mean excitation energies for the study of atomic and molecular stopping until the advances on generalized oscillator strength and sum rules in the study of stopping cross sections. Finally, as a tribute to Jens' work on the orbital implementation of the kinetic theory of stopping, in this work we present new results on the use of the Thomas-Fermi-Dirac-Weizsäcker density functional for the calculation of orbital and total atomic mean excitation energies. The results are applied to free-atoms and and extension is done to confined atoms - taking Si as an example - whereby target pressure effects on stopping are derived. Hence, evidence of the far-yield of Jens' ideas is given.

  1. Catalystlike effect of orbital angular momentum on the conversion of transverse to three-dimensional spin states within tightly focused radially polarized beams

    Science.gov (United States)

    Han, Lei; Liu, Sheng; Li, Peng; Zhang, Yi; Cheng, Huachao; Zhao, Jianlin

    2018-05-01

    We report on the catalystlike effect of orbital angular momentum (OAM) on local spin-state conversion within the tightly focused radially polarized beams associated with optical spin-orbit interaction. It is theoretically demonstrated that the incident OAM can lead to a conversion of purely transverse spin state to a three-dimensional spin state on the focal plane. This conversion can be conveniently manipulated by altering the sign and value of the OAM. By comparing the total OAM and spin angular momentum (SAM) on the incident plane to those on the focal plane, it is indicated that the incident OAM have no participation in the angular momentum intertransfer, and just play a role as a catalyst of local SAM conversion. Such an effect of OAM sheds new light on the optical spin-orbit interaction in tight-focusing processes. The resultant three-dimensional spin states may provide more degrees of freedom in optical manipulation and spin-dependent directive coupling.

  2. ImaEdge - a platform for quantitative analysis of the spatiotemporal dynamics of cortical proteins during cell polarization.

    Science.gov (United States)

    Zhang, Zhen; Lim, Yen Wei; Zhao, Peng; Kanchanawong, Pakorn; Motegi, Fumio

    2017-12-15

    Cell polarity involves the compartmentalization of the cell cortex. The establishment of cortical compartments arises from the spatial bias in the activity and concentration of cortical proteins. The mechanistic dissection of cell polarity requires the accurate detection of dynamic changes in cortical proteins, but the fluctuations of cell shape and the inhomogeneous distributions of cortical proteins greatly complicate the quantitative extraction of their global and local changes during cell polarization. To address these problems, we introduce an open-source software package, ImaEdge, which automates the segmentation of the cortex from time-lapse movies, and enables quantitative extraction of cortical protein intensities. We demonstrate that ImaEdge enables efficient and rigorous analysis of the dynamic evolution of cortical PAR proteins during Caenorhabditis elegans embryogenesis. It is also capable of accurate tracking of varying levels of transgene expression and discontinuous signals of the actomyosin cytoskeleton during multiple rounds of cell division. ImaEdge provides a unique resource for quantitative studies of cortical polarization, with the potential for application to many types of polarized cells.This article has an associated First Person interview with the first authors of the paper. © 2017. Published by The Company of Biologists Ltd.

  3. Determination of the spin orbit coupling and crystal field splitting in wurtzite InP by polarization resolved photoluminescence

    Science.gov (United States)

    Chauvin, Nicolas; Mavel, Amaury; Jaffal, Ali; Patriarche, Gilles; Gendry, Michel

    2018-02-01

    Excitation photoluminescence spectroscopy is usually used to extract the crystal field splitting (ΔCR) and spin orbit coupling (ΔSO) parameters of wurtzite (Wz) InP nanowires (NWs). However, the equations expressing the valence band splitting are symmetric with respect to these two parameters, and a choice ΔCR > ΔSO or ΔCR InP NWs grown on silicon. The experimental results combined with a theoretical model and finite difference time domain calculations allow us to conclude that ΔCR > ΔSO in Wz InP.

  4. Discovery of highly spin-polarized conducting surface states in the strong spin-orbit coupling semiconductor Sb2Se3

    Science.gov (United States)

    Das, Shekhar; Sirohi, Anshu; Kumar Gupta, Gaurav; Kamboj, Suman; Vasdev, Aastha; Gayen, Sirshendu; Guptasarma, Prasenjit; Das, Tanmoy; Sheet, Goutam

    2018-06-01

    Majority of the A2B3 -type chalcogenide systems with strong spin-orbit coupling (SOC), such as Bi2Se3,Bi2Te3 , and Sb2Te3 , etc., are topological insulators. One important exception is Sb2Se3 where a topological nontrivial phase was argued to be possible under ambient conditions, but such a phase could be detected to exist only under pressure. In this paper, we show that Sb2Se3 like Bi2Se3 displays a generation of highly spin-polarized current under mesoscopic superconducting point contacts as measured by point-contact Andreev reflection spectroscopy. In addition, we observe a large negative and anisotropic magnetoresistance of the mesoscopic metallic point contacts formed on Sb2Se3 . Our band-structure calculations confirm the trivial nature of Sb2Se3 crystals and reveal two trivial surface states one of which shows large spin splitting due to Rashba-type SOC. The observed high spin polarization and related phenomena in Sb2Se3 can be attributed to this spin splitting.

  5. Real-Time Study of the Interaction between G-Rich DNA Oligonucleotides and Lead Ion on DNA Tetrahedron-Functionalized Sensing Platform by Dual Polarization Interferometry.

    Science.gov (United States)

    Wang, Shuang; Lu, Shasha; Zhao, Jiahui; Huang, Jianshe; Yang, Xiurong

    2017-11-29

    G-quadruplex plays roles in numerous physiological and pathological processes of organisms. Due to the unique properties of G-quadruplex (e.g., forming G4/hemin complexes with catalytic activity and electron acceptability, binding with metal ions, proteins, fluorescent ligands, and so on), it has been widely applied in biosensing. But the formation process of G-quadruplex is not yet fully understood. Here, a DNA tetrahedron platform with higher reproducibility, regenerative ability, and time-saving building process was coupled with dual polarization interferometry technique for the real-time and label-free investigation of the specific interaction process of guanine-rich singled-stranded DNA (G-rich ssDNA) and Pb 2+ . The oriented immobilization of probes greatly decreased the spatial hindrance effect and improved the accessibility of the probes to the Pb 2+ ions. Through real-time monitoring of the whole formation process of the G-quadruplex, we speculated that the probes on the tetrahedron platform initially stood on the sensing surface with a random coil conformation, then the G-rich ssDNA preliminarily formed unstable G-quartets by H-bonding and cation binding, subsequently forming a completely folded and stable quadruplex structure through relatively slow strand rearrangements. On the basis of these studies, we also developed a novel sensing platform for the specific and sensitive determination of Pb 2+ and its chelating agent ethylenediaminetetraacetic acid. This study not only provides a proof-of-concept for conformational dynamics of G-quadruplex-related drugs and pathogenes, but also enriches the biosensor tools by combining nanomaterial with interfaces technique.

  6. Spin-polarized currents in a two-terminal double quantum ring driven by magnetic fields and Rashba spin-orbit interaction

    Science.gov (United States)

    Dehghan, E.; Khoshnoud, D. Sanavi; Naeimi, A. S.

    2018-06-01

    Aim of this study is to investigate spin transportation in double quantum ring (DQR). We developed an array of DQR to measure the transmission coefficient and analyze the spin transportation through this system in the presence of Rashba spin-orbit interaction (RSOI) and magnetic flux estimated using S-matrix method. In this article, we compute the spin transport and spin-current characteristics numerically as functions of electron energy, angles between the leads, coupling constant of the leads, RSOI, and magnetic flux. Our results suggest that, for typical values of the magnetic flux (ϕ /ϕ0) and Rashba constant (αR), such system can demonstrates many spintronic properties. It is possible to design a new geometry of DQR by incoming electrons polarization in a way to optimize the system to work as a spin-filtering and spin-inverting nano-device with very high efficiency. The results prove that the spin current will strongly modulate with an increase in the magnetic flux and Rashba constant. Moreover it is shown that, when the lead coupling is weak, the perfect spin-inverter does not occur.

  7. Spin-polarization and spin-dependent logic gates in a double quantum ring based on Rashba spin-orbit effect: Non-equilibrium Green's function approach

    International Nuclear Information System (INIS)

    Eslami, Leila; Esmaeilzadeh, Mahdi

    2014-01-01

    Spin-dependent electron transport in an open double quantum ring, when each ring is made up of four quantum dots and threaded by a magnetic flux, is studied. Two independent and tunable gate voltages are applied to induce Rashba spin-orbit effect in the quantum rings. Using non-equilibrium Green's function formalism, we study the effects of electron-electron interaction on spin-dependent electron transport and show that although the electron-electron interaction induces an energy gap, it has no considerable effect when the bias voltage is sufficiently high. We also show that the double quantum ring can operate as a spin-filter for both spin up and spin down electrons. The spin-polarization of transmitted electrons can be tuned from −1 (pure spin-down current) to +1 (pure spin-up current) by changing the magnetic flux and/or the gates voltage. Also, the double quantum ring can act as AND and NOR gates when the system parameters such as Rashba coefficient are properly adjusted

  8. The third post-Newtonian gravitational wave polarizations and associated spherical harmonic modes for inspiralling compact binaries in quasi-circular orbits

    International Nuclear Information System (INIS)

    Blanchet, Luc; Faye, Guillaume; Iyer, Bala R; Sinha, Siddhartha

    2008-01-01

    The gravitational waveform (GWF) generated by inspiralling compact binaries moving in quasi-circular orbits is computed at the third post-Newtonian (3PN) approximation to general relativity. Our motivation is two-fold: (i) to provide accurate templates for the data analysis of gravitational wave inspiral signals in laser interferometric detectors; (ii) to provide the associated spin-weighted spherical harmonic decomposition to facilitate comparison and match of the high post-Newtonian prediction for the inspiral waveform to the numerically-generated waveforms for the merger and ringdown. This extension of the GWF by half a PN order (with respect to previous work at 2.5PN order) is based on the algorithm of the multipolar post-Minkowskian formalism, and mandates the computation of the relations between the radiative, canonical and source multipole moments for general sources at 3PN order. We also obtain the 3PN extension of the source multipole moments in the case of compact binaries, and compute the contributions of hereditary terms (tails, tails-of-tails and memory integrals) up to 3PN order. The end results are given for both the complete plus and cross polarizations and the separate spin-weighted spherical harmonic modes

  9. Polar Stratigraphy

    Science.gov (United States)

    1999-01-01

    These three images were taken on three different orbits over the north polar cap in April 1999. Each shows a different part of the same ice-free trough. The left and right images are separated by a distance of more than 100 kilometers (62 miles). Note the similar layers in each image.

  10. Towards high temporal and moderate spatial resolutions in the remote sensing retrieval of evapotranspiration by combining geostationary and polar orbit satellite data

    Science.gov (United States)

    Barrios, José Miguel; Ghilain, Nicolas; Arboleda, Alirio; Gellens-Meulenberghs, Françoise

    2014-05-01

    Evapotranspiration (ET) is the water flux going from the surface into the atmosphere as result of soil and surface water evaporation and plant transpiration. It constitutes a key component of the water cycle and its quantification is of crucial importance for a number of applications like water management, climatic modelling, agriculture monitoring and planning, etc. Estimating ET is not an easy task; specially if large areas are envisaged and various spatio-temporal patterns of ET are present as result of heterogeneity in land cover, land use and climatic conditions. In this respect, spaceborne remote sensing (RS) provides the only alternative to continuously measure surface parameters related to ET over large areas. The Royal Meteorological Institute (RMI) of Belgium, in the framework of EUMETSAT's "Land Surface Analysis-Satellite Application Facility" (LSA-SAF), has developed a model for the estimation of ET. The model is forced by RS data, numerical weather predictions and land cover information. The RS forcing is derived from measurements by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard the Meteosat Second Generation (MSG) satellite. This ET model is operational and delivers ET estimations over the whole field of view of the MSG satellite (Europe, Africa and Eastern South America) (http://landsaf.meteo.pt) every 30 minutes. The spatial resolution of MSG is 3 x 3 km at subsatellite point and about 4 x 5 km in continental Europe. The spatial resolution of this product may constrain its full exploitation as the interest of potential users (farmers and natural resources scientists) may lie on smaller spatial units. This study aimed at testing methodological alternatives to combine RS imagery (geostationary and polar orbit satellites) for the estimation of ET such that the spatial resolution of the final product is improved. In particular, the study consisted in the implementation of two approaches for combining the current ET estimations with

  11. Space station orbit maintenance

    Science.gov (United States)

    Kaplan, D. I.; Jones, R. M.

    1983-01-01

    The orbit maintenance problem is examined for two low-earth-orbiting space station concepts - the large, manned Space Operations Center (SOC) and the smaller, unmanned Science and Applications Space Platform (SASP). Atmospheric drag forces are calculated, and circular orbit altitudes are selected to assure a 90 day decay period in the event of catastrophic propulsion system failure. Several thrusting strategies for orbit maintenance are discussed. Various chemical and electric propulsion systems for orbit maintenance are compared on the basis of propellant resupply requirements, power requirements, Shuttle launch costs, and technology readiness.

  12. Characteristics of anomalous Hall effect in spin-polarized two-dimensional electron gases in the presence of both intrinsic, extrinsic, and external electric-field induced spin—orbit couplings

    International Nuclear Information System (INIS)

    Liu Song; Yan Yu-Zhen; Hu Liang-Bin

    2012-01-01

    The various competing contributions to the anomalous Hall effect in spin-polarized two-dimensional electron gases in the presence of both intrinsic, extrinsic and external electric-field induced spin—orbit coupling were investigated theoretically. Based on a unified semiclassical theoretical approach, it is shown that the total anomalous Hall conductivity can be expressed as the sum of three distinct contributions in the presence of these competing spin—orbit interactions, namely an intrinsic contribution determined by the Berry curvature in the momentum space, an extrinsic contribution determined by the modified Bloch band group velocity and an extrinsic contribution determined by spin—orbit-dependent impurity scattering. The characteristics of these competing contributions are discussed in detail in the paper. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  13. Source of spin polarized electrons

    International Nuclear Information System (INIS)

    Pierce, D.T.; Meier, F.A.; Siegmann, H.C.

    1976-01-01

    A method is described of producing intense beams of polarized free electrons in which a semiconductor with a spin orbit split valence band and negative electron affinity is used as a photocathode and irradiated with circularly polarized light

  14. Electron spin polarization induced by spin Hall effect in semiconductors with a linear in the momentum spin-orbit splitting of conduction band

    OpenAIRE

    Korenev, V. L.

    2005-01-01

    It is shown that spin Hall effect creates uniform spin polarization of electrons in semiconductor with a linear in the momentum spin splitting of conduction band. In turn, the profile of the non-uniform spin polarization accumulated at the edge of the sample oscillates in space even in the absence of an external magnetic field.

  15. SSTO RLVs: More Global Reach? A Study of the Use of Single Stage to Orbit Reusable Launch Vehicles as Airlift Platforms.

    Science.gov (United States)

    1996-11-01

    Orbit ( SSTO ) Reusable Launch Vehicles (RLVs) are currently under cooperative development by NASA, the Air Force, and the aerospace industry in the pursuit...exploit these rapid transit technologies to advance ’Global Reach for America.’ The SSTO RLV is a single stage rocket that will be completely reusable...investigated to assess the projected capabilities and costs of the SSTO system. This paper reviews the proposed capabilities of the SSTO system, discusses

  16. Calculations of spin-polarized Goos-Hänchen displacement in magnetically confined GaAs/Al x Ga1-x As nanostructure modulated by spin-orbit couplings

    Science.gov (United States)

    Lu, Mao-Wang; Chen, Sai-Yan; Zhang, Gui-Lian; Huang, Xin-Hong

    2018-04-01

    We theoretically investigate Goos-Hänchen (GH) displacement by modelling the spin transport in an archetypal device structure—a magnetically confined GaAs/Al x Ga1-x As nanostructure modulated by spin-orbit coupling (SOC). Both Rashba and Dresselhaus SOCs are taken into account. The degree of spin-polarized GH displacement can be tuned by Rashba or Dresselhaus SOC, i.e. interfacial confining electric field or strain engineering. Based on such a semiconductor nanostructure, a controllable spatial spin splitter can be proposed for spintronics applications.

  17. Calculations of spin-polarized Goos-Hänchen displacement in magnetically confined GaAs/Al x Ga1-x As nanostructure modulated by spin-orbit couplings.

    Science.gov (United States)

    Lu, Mao-Wang; Chen, Sai-Yan; Zhang, Gui-Lian; Huang, Xin-Hong

    2018-04-11

    We theoretically investigate Goos-Hänchen (GH) displacement by modelling the spin transport in an archetypal device structure-a magnetically confined GaAs/Al x Ga 1-x As nanostructure modulated by spin-orbit coupling (SOC). Both Rashba and Dresselhaus SOCs are taken into account. The degree of spin-polarized GH displacement can be tuned by Rashba or Dresselhaus SOC, i.e. interfacial confining electric field or strain engineering. Based on such a semiconductor nanostructure, a controllable spatial spin splitter can be proposed for spintronics applications.

  18. Ionization of oriented targets by intense circularly polarized laser pulses: Imprints of orbital angular nodes in the two-dimensional momentum distribution

    DEFF Research Database (Denmark)

    Martiny, Christian; Abu-Samha, Mahmoud; Madsen, Lars Bojer

    2010-01-01

    We solve the three-dimensional time-dependent Schrödinger equation for a few-cycle circularly polarized femtosecond laser pulse that interacts with an oriented target exemplified by an argon atom, initially in a 3px or 3py state. The photoelectron momentum distributions show distinct signatures o...

  19. Evidence for Surface Water Ice in the Lunar Polar Regions Using Reflectance Measurements from the Lunar Orbiter Laser Altimeter and Temperature Measurements from the Diviner Lunar Radiometer Experiment

    Science.gov (United States)

    Fisher, Elizabeth A.; Lucey, Paul G.; Lemelin, Myriam; Greenhagen, Benjamin T.; Siegler, Matthew A.; Mazarico, Erwan; Aharonson, Oded; Williams, Jean-Pierre; Hayne, Paul O.; Neumann, Gregory A.; hide

    2017-01-01

    We find that the reflectance of the lunar surface within 5 deg of latitude of theSouth Pole increases rapidly with decreasing temperature, near approximately 110K, behavior consistent with the presence of surface water ice. The North polar region does not show this behavior, nor do South polar surfaces at latitudes more than 5 deg from the pole. This South pole reflectance anomaly persists when analysis is limited to surfaces with slopes less than 10 deg to eliminate false detection due to the brightening effect of mass wasting, and also when the very bright south polar crater Shackleton is excluded from the analysis. We also find that south polar regions of permanent shadow that have been reported to be generally brighter at 1064 nm do not show anomalous reflectance when their annual maximum surface temperatures are too high to preserve water ice. This distinction is not observed at the North Pole. The reflectance excursion on surfaces with maximum temperatures below 110K is superimposed on a general trend of increasing reflectance with decreasing maximum temperature that is present throughout the polar regions in the north and south; we attribute this trend to a temperature or illumination-dependent space weathering effect (e.g. Hemingway et al. 2015). We also find a sudden increase in reflectance with decreasing temperature superimposed on the general trend at 200K and possibly at 300K. This may indicate the presence of other volatiles such as sulfur or organics. We identified and mapped surfaces with reflectances so high as to be unlikely to be part of an ice-free population. In this south we find a similar distribution found by Hayne et al. 2015 based on UV properties. In the north a cluster of pixels near that pole may represent a limited frost exposure.

  20. Evidence for surface water ice in the lunar polar regions using reflectance measurements from the Lunar Orbiter Laser Altimeter and temperature measurements from the Diviner Lunar Radiometer Experiment

    Science.gov (United States)

    Fisher, Elizabeth A.; Lucey, Paul G.; Lemelin, Myriam; Greenhagen, Benjamin T.; Siegler, Matthew A.; Mazarico, Erwan; Aharonson, Oded; Williams, Jean-Pierre; Hayne, Paul O.; Neumann, Gregory A.; Paige, David A.; Smith, David E.; Zuber, Maria T.

    2017-08-01

    We find that the reflectance of the lunar surface within 5° of latitude of the South Pole increases rapidly with decreasing temperature, near ∼110 K, behavior consistent with the presence of surface water ice. The North polar region does not show this behavior, nor do South polar surfaces at latitudes more than 5° from the pole. This South pole reflectance anomaly persists when analysis is limited to surfaces with slopes less than 10° to eliminate false detection due to the brightening effect of mass wasting, and also when the very bright south polar crater Shackleton is excluded from the analysis. We also find that south polar regions of permanent shadow that have been reported to be generally brighter at 1064 nm do not show anomalous reflectance when their annual maximum surface temperatures are too high to preserve water ice. This distinction is not observed at the North Pole. The reflectance excursion on surfaces with maximum temperatures below 110 K is superimposed on a general trend of increasing reflectance with decreasing maximum temperature that is present throughout the polar regions in the north and south; we attribute this trend to a temperature or illumination-dependent space weathering effect (e.g. Hemingway et al., 2015). We also find a sudden increase in reflectance with decreasing temperature superimposed on the general trend at 200 K and possibly at 300 K. This may indicate the presence of other volatiles such as sulfur or organics. We identified and mapped surfaces with reflectances so high as to be unlikely to be part of an ice-free population. In this south we find a similar distribution found by Hayne et al. (2015) based on UV properties. In the north a cluster of pixels near that pole may represent a limited frost exposure.

  1. Lidar Orbital Angular Momentum Sensor

    Data.gov (United States)

    National Aeronautics and Space Administration — The recognition in recent decades that electromagnetic fields have angular momentum (AM) in the form of not only polarization (or spin AM) but also orbital (OAM) has...

  2. Peripheral orbit model

    CERN Document Server

    Hara, Yasuo

    1975-01-01

    Peripheral orbit model, in which an incoming hadron is assumed to revolve in a peripheral orbit around a target hadron, is discussed. The non-diffractive parts of two-body reaction amplitudes of hadrons are expressed in terms of the radius, width an absorptivity of the orbit. The radius of the orbit is about 1 fm and the width of the orbit is determined by the range of the interaction between the hadrons. The model reproduces all available experimental data on differential cross-sections and polarizations of $K^{-}p\\to K^{-}p$ and $\\bar K^{\\circ}n$ reactions for all angles successfully. This contribution is not included in the proceedings since it will appear in Progress of Theoretical Physics Vol. 51 (1974) No 2. Any person interested in the subject may apply for reprints to the author.

  3. Polar Polygons

    Science.gov (United States)

    2005-01-01

    18 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark-outlined polygons on a frost-covered surface in the south polar region of Mars. In summer, this surface would not be bright and the polygons would not have dark outlines--these are a product of the presence of seasonal frost. Location near: 77.2oS, 204.8oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  4. Polarization effects in hadron fragmentation

    International Nuclear Information System (INIS)

    Lednicky, R.

    1984-01-01

    Hadron polarization (spin alignment) and polarization asymmetry are discussed in terms of the quark recombination model with the spin-orbit interaction taken into account. It is shown that predictions of this model are at least in qualitative agreement with experimental data. Various polarization mechanisms in terms of this model and the possibility of their checking are also discussed

  5. Induced spin-accumulation and spin-polarization in a quantum-dot ring by using magnetic quantum dots and Rashba spin-orbit effect

    International Nuclear Information System (INIS)

    Eslami, L.; Faizabadi, E.

    2014-01-01

    The effect of magnetic contacts on spin-dependent electron transport and spin-accumulation in a quantum ring, which is threaded by a magnetic flux, is studied. The quantum ring is made up of four quantum dots, where two of them possess magnetic structure and other ones are subjected to the Rashba spin-orbit coupling. The magnetic quantum dots, referred to as magnetic quantum contacts, are connected to two external leads. Two different configurations of magnetic moments of the quantum contacts are considered; the parallel and the anti-parallel ones. When the magnetic moments are parallel, the degeneracy between the transmission coefficients of spin-up and spin-down electrons is lifted and the system can be adjusted to operate as a spin-filter. In addition, the accumulation of spin-up and spin-down electrons in non-magnetic quantum dots are different in the case of parallel magnetic moments. When the intra-dot Coulomb interaction is taken into account, we find that the electron interactions participate in separation between the accumulations of electrons with different spin directions in non-magnetic quantum dots. Furthermore, the spin-accumulation in non-magnetic quantum dots can be tuned in the both parallel and anti-parallel magnetic moments by adjusting the Rashba spin-orbit strength and the magnetic flux. Thus, the quantum ring with magnetic quantum contacts could be utilized to create tunable local magnetic moments which can be used in designing optimized nanodevices.

  6. Operational factors affecting microgravity levels in orbit

    Science.gov (United States)

    Olsen, R. E.; Mockovciak, J., Jr.

    1980-01-01

    Microgravity levels desired for proposed materials processing payloads are fundamental considerations in the design of future space platforms. Disturbance sources, such as aerodynamic drag, attitude control torques, crew motion and orbital dynamics, influence the microgravity levels attainable in orbit. The nature of these effects are assessed relative to platform design parameters such as orbital altitude and configuration geometry, and examples are presented for a representative spacecraft configuration. The possible applications of control techniques to provide extremely low acceleration levels are also discussed.

  7. Dynamics of the outer radiation belts and their links with the polar substorms and the injection of hot plasma at the geostationary orbit

    International Nuclear Information System (INIS)

    Sauvaud, J.A.; Winckler, J.R.

    1981-01-01

    The aim of this paper is to analyse the results obtained aboard geostationary satellites and on the ground, in the auroral zone, on the dynamic changes in the outer radiation belts and their link with the time development of auroral forms during magnetospheric substorms. The measurements of high-energy particles, plasma, and magnetic induction at 6.6 Rsub(E) in the local midnight sector indicate the existence of a pre-expansion phase in substorms during which the outer belts move toward the Earth under the effect of the modification in the topology of the local magnetic induction. The pre-expansion phase coincides with an increase in the AE index, suggesting a direct link between the electrojet and the currents flowing across the tail of the magnetosphere. It also coincides in the auroral zone with the intensification and movement of the quiet arc system toward the equator. The phase is invariably terminated at the beginning of the expansion of the substorm by the break-up of the auroral arcs and the injection of hot plasma at the geostationary orbit near local midnight under the action of the induced electric field associated with the collapse of the geomagnetic field force lines. The study of the data, event by event, shows the complexity of phenomena which may be involved during the pre-expansion phase particularly with the possible presence of pseudo-substorms or aborted (minor) substorms which do not modify the general evolution described above [fr

  8. Orbit Functions

    Directory of Open Access Journals (Sweden)

    Anatoliy Klimyk

    2006-01-01

    Full Text Available In the paper, properties of orbit functions are reviewed and further developed. Orbit functions on the Euclidean space E_n are symmetrized exponential functions. The symmetrization is fulfilled by a Weyl group corresponding to a Coxeter-Dynkin diagram. Properties of such functions will be described. An orbit function is the contribution to an irreducible character of a compact semisimple Lie group G of rank n from one of its Weyl group orbits. It is shown that values of orbit functions are repeated on copies of the fundamental domain F of the affine Weyl group (determined by the initial Weyl group in the entire Euclidean space E_n. Orbit functions are solutions of the corresponding Laplace equation in E_n, satisfying the Neumann condition on the boundary of F. Orbit functions determine a symmetrized Fourier transform and a transform on a finite set of points.

  9. Ship emissions measurement in the Arctic by plume intercepts of the Canadian Coast Guard icebreaker Amundsen from the Polar 6 aircraft platform

    Science.gov (United States)

    Aliabadi, Amir A.; Thomas, Jennie L.; Herber, Andreas B.; Staebler, Ralf M.; Leaitch, W. Richard; Schulz, Hannes; Law, Kathy S.; Marelle, Louis; Burkart, Julia; Willis, Megan D.; Bozem, Heiko; Hoor, Peter M.; Köllner, Franziska; Schneider, Johannes; Levasseur, Maurice; Abbatt, Jonathan P. D.

    2016-06-01

    Decreasing sea ice and increasing marine navigability in northern latitudes have changed Arctic ship traffic patterns in recent years and are predicted to increase annual ship traffic in the Arctic in the future. Development of effective regulations to manage environmental impacts of shipping requires an understanding of ship emissions and atmospheric processing in the Arctic environment. As part of the summer 2014 NETCARE (Network on Climate and Aerosols) campaign, the plume dispersion and gas and particle emission factors of effluents originating from the Canadian Coast Guard icebreaker Amundsen operating near Resolute Bay, NU, Canada, were investigated. The Amundsen burned distillate fuel with 1.5 wt % sulfur. Emissions were studied via plume intercepts using the Polar 6 aircraft measurements, an analytical plume dispersion model, and using the FLEXPART-WRF Lagrangian particle dispersion model. The first plume intercept by the research aircraft was carried out on 19 July 2014 during the operation of the Amundsen in the open water. The second and third plume intercepts were carried out on 20 and 21 July 2014 when the Amundsen had reached the ice edge and operated under ice-breaking conditions. Typical of Arctic marine navigation, the engine load was low compared to cruising conditions for all of the plume intercepts. The measured species included mixing ratios of CO2, NOx, CO, SO2, particle number concentration (CN), refractory black carbon (rBC), and cloud condensation nuclei (CCN). The results were compared to similar experimental studies in mid-latitudes. Plume expansion rates (γ) were calculated using the analytical model and found to be γ = 0.75 ± 0.81, 0.93 ± 0.37, and 1.19 ± 0.39 for plumes 1, 2, and 3, respectively. These rates were smaller than prior studies conducted at mid-latitudes, likely due to polar boundary layer dynamics, including reduced turbulent mixing compared to mid-latitudes. All emission factors were in agreement with prior

  10. Instrumentation with polarized neutrons

    International Nuclear Information System (INIS)

    Boeni, P.; Muenzer, W.; Ostermann, A.

    2009-01-01

    Neutron scattering with polarization analysis is an indispensable tool for the investigation of novel materials exhibiting electronic, magnetic, and orbital degrees of freedom. In addition, polarized neutrons are necessary for neutron spin precession techniques that path the way to obtain extremely high resolution in space and time. Last but not least, polarized neutrons are being used for fundamental studies as well as very recently for neutron imaging. Many years ago, neutron beam lines were simply adapted for polarized beam applications by adding polarizing elements leading usually to unacceptable losses in neutron intensity. Recently, an increasing number of beam lines are designed such that an optimum use of polarized neutrons is facilitated. In addition, marked progress has been obtained in the technology of 3 He polarizers and the reflectivity of large-m supermirrors. Therefore, if properly designed, only factors of approximately 2-3 in neutron intensity are lost. It is shown that S-benders provide neutron beams with an almost wavelength independent polarization. Using twin cavities, polarized beams with a homogeneous phase space and P>0.99 can be produced without significantly sacrificing intensity. It is argued that elliptic guides, which are coated with large m polarizing supermirrors, provide the highest flux.

  11. The Eccentric Behavior of Nearly Frozen Orbits

    Science.gov (United States)

    Sweetser, Theodore H.; Vincent, Mark A.

    2013-01-01

    Frozen orbits are orbits which have only short-period changes in their mean eccentricity and argument of periapse, so that they basically keep a fixed orientation within their plane of motion. Nearly frozen orbits are those whose eccentricity and argument of periapse have values close to those of a frozen orbit. We call them "nearly" frozen because their eccentricity vector (a vector whose polar coordinates are eccentricity and argument of periapse) will stay within a bounded distance from the frozen orbit eccentricity vector, circulating around it over time. For highly inclined orbits around the Earth, this distance is effectively constant over time. Furthermore, frozen orbit eccentricity values are low enough that these orbits are essentially eccentric (i.e., off center) circles, so that nearly frozen orbits around Earth are bounded above and below by frozen orbits.

  12. Polarized neutrons

    International Nuclear Information System (INIS)

    Williams, W.G.

    1988-01-01

    The book on 'polarized neutrons' is intended to inform researchers in condensed matter physics and chemistry of the diversity of scientific problems that can be investigated using polarized neutron beams. The contents include chapters on:- neutron polarizers and instrumentation, polarized neutron scattering, neutron polarization analysis experiments and precessing neutron polarization. (U.K.)

  13. Ship emissions measurement in the Arctic by plume intercepts of the Canadian Coast Guard icebreaker Amundsen from the Polar 6 aircraft platform

    Directory of Open Access Journals (Sweden)

    A. A. Aliabadi

    2016-06-01

    Full Text Available Decreasing sea ice and increasing marine navigability in northern latitudes have changed Arctic ship traffic patterns in recent years and are predicted to increase annual ship traffic in the Arctic in the future. Development of effective regulations to manage environmental impacts of shipping requires an understanding of ship emissions and atmospheric processing in the Arctic environment. As part of the summer 2014 NETCARE (Network on Climate and Aerosols campaign, the plume dispersion and gas and particle emission factors of effluents originating from the Canadian Coast Guard icebreaker Amundsen operating near Resolute Bay, NU, Canada, were investigated. The Amundsen burned distillate fuel with 1.5 wt % sulfur. Emissions were studied via plume intercepts using the Polar 6 aircraft measurements, an analytical plume dispersion model, and using the FLEXPART-WRF Lagrangian particle dispersion model. The first plume intercept by the research aircraft was carried out on 19 July 2014 during the operation of the Amundsen in the open water. The second and third plume intercepts were carried out on 20 and 21 July 2014 when the Amundsen had reached the ice edge and operated under ice-breaking conditions. Typical of Arctic marine navigation, the engine load was low compared to cruising conditions for all of the plume intercepts. The measured species included mixing ratios of CO2, NOx, CO, SO2, particle number concentration (CN, refractory black carbon (rBC, and cloud condensation nuclei (CCN. The results were compared to similar experimental studies in mid-latitudes. Plume expansion rates (γ were calculated using the analytical model and found to be γ  =  0.75 ± 0.81, 0.93 ± 0.37, and 1.19 ± 0.39 for plumes 1, 2, and 3, respectively. These rates were smaller than prior studies conducted at mid-latitudes, likely due to polar boundary layer dynamics, including reduced turbulent mixing compared to mid-latitudes. All emission

  14. ORBITAL INJURIES

    Directory of Open Access Journals (Sweden)

    Andrej Kansky

    2002-12-01

    Full Text Available Background. Orbit is involved in 40% of all facial fractures. There is considerable variety in severity, ranging from simple nondisplaced to complex comminuted fractures. Complex comminuted fractures (up to 20% are responsible for the majority of complications and unfavorable results. Orbital fractures are classified as internal orbital fractures, zygomatico-orbital fractures, naso-orbito-ethmoidal fractures and combined fractures. The ophtalmic sequelae of midfacial fractures are usually edema and ecchymosis of the soft tissues, subconjuctival hemorrhage, diplopia, iritis, retinal edema, ptosis, enophthalmos, ocular muscle paresis, mechanical restriction of ocular movement and nasolacrimal disturbances. More severe injuries such as optic nerve trauma and retinal detachments have also been reported. Within the wide range of orbital fractures small group of complex fractures causes most of the sequelae. Therefore identification of severe injuries and adequate treatment is of major importance. The introduction of craniofacial techniques made possible a wide exposure even of large orbital wall defects and their reconstruction by bone grafts. In spite of significant progress, repair of complex orbital wall defects remains a problem even for the experienced surgeons.Results. In 1999 121 facial injuries were treated at our department (Clinical Centre Ljubljana Dept. Of Maxillofacial and Oral Surgery. Orbit was involved in 65% of cases. Isolated inner orbital fractures presented 4% of all fractures. 17 (14% complex cases were treated, 5 of them being NOE, 5 orbital (frame and inner walls, 3 zygomatico-orbital, 2 FNO and 2 maxillo-orbital fractures.Conclusions. Final result of the surgical treatment depends on severity of maxillofacial trauma. Complex comminuted fractures are responsable for most of the unfavorable results and ocular function is often permanently damaged (up to 75% in these fractures.

  15. [Orbital inflammation].

    Science.gov (United States)

    Mouriaux, F; Coffin-Pichonnet, S; Robert, P-Y; Abad, S; Martin-Silva, N

    2014-12-01

    Orbital inflammation is a generic term encompassing inflammatory pathologies affecting all structures within the orbit : anterior (involvement up to the posterior aspect of the globe), diffuse (involvement of intra- and/or extraconal fat), apical (involvement of the posterior orbit), myositis (involvement of only the extraocular muscles), dacryoadenitis (involvement of the lacrimal gland). We distinguish between specific inflammation and non-specific inflammation, commonly referred to as idiopathic inflammation. Specific orbital inflammation corresponds to a secondary localization of a "generalized" disease (systemic or auto-immune). Idiopathic orbital inflammation corresponds to uniquely orbital inflammation without generalized disease, and thus an unknown etiology. At the top of the differential diagnosis for specific or idiopathic orbital inflammation are malignant tumors, represented most commonly in the adult by lympho-proliferative syndromes and metastases. Treatment of specific orbital inflammation begins with treatment of the underlying disease. For idiopathic orbital inflammation, treatment (most often corticosteroids) is indicated above all in cases of visual loss due to optic neuropathy, in the presence of pain or oculomotor palsy. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  16. Payment Platform

    DEFF Research Database (Denmark)

    Hjelholt, Morten; Damsgaard, Jan

    2012-01-01

    thoroughly and substitute current payment standards in the decades to come. This paper portrays how digital payment platforms evolve in socio-technical niches and how various technological platforms aim for institutional attention in their attempt to challenge earlier platforms and standards. The paper...... applies a co-evolutionary multilevel perspective to model the interplay and processes between technology and society wherein digital payment platforms potentially will substitute other payment platforms just like the credit card negated the check. On this basis this paper formulate a multilevel conceptual...

  17. Cygnus X-1: Discovery of variable circular polarization

    International Nuclear Information System (INIS)

    Michalsky, J.J.; Swedlund, J.B.; Stokes, R.A.

    1975-01-01

    HDE 226868, the optical counterpart of Cyg X-1, has been observed for circular polarization during 1974. Observations in five colors suggest that circular polarization results from an interstellar effect. Measurements of the blue polarization reveal circular polarization variations synchronous with the 5)./sub /6 orbital period. The circular polarization variation appears to be similar to the blue intensity variation

  18. The effects of different footprint sizes and cloud algorithms on the top-of-atmosphere radiative flux calculation from the Clouds and Earth's Radiant Energy System (CERES instrument on Suomi National Polar-orbiting Partnership (NPP

    Directory of Open Access Journals (Sweden)

    W. Su

    2017-10-01

    Full Text Available Only one Clouds and Earth's Radiant Energy System (CERES instrument is onboard the Suomi National Polar-orbiting Partnership (NPP and it has been placed in cross-track mode since launch; it is thus not possible to construct a set of angular distribution models (ADMs specific for CERES on NPP. Edition 4 Aqua ADMs are used for flux inversions for NPP CERES measurements. However, the footprint size of NPP CERES is greater than that of Aqua CERES, as the altitude of the NPP orbit is higher than that of the Aqua orbit. Furthermore, cloud retrievals from the Visible Infrared Imaging Radiometer Suite (VIIRS and the Moderate Resolution Imaging Spectroradiometer (MODIS, which are the imagers sharing the spacecraft with NPP CERES and Aqua CERES, are also different. To quantify the flux uncertainties due to the footprint size difference between Aqua CERES and NPP CERES, and due to both the footprint size difference and cloud property difference, a simulation is designed using the MODIS pixel-level data, which are convolved with the Aqua CERES and NPP CERES point spread functions (PSFs into their respective footprints. The simulation is designed to isolate the effects of footprint size and cloud property differences on flux uncertainty from calibration and orbital differences between NPP CERES and Aqua CERES. The footprint size difference between Aqua CERES and NPP CERES introduces instantaneous flux uncertainties in monthly gridded NPP CERES measurements of less than 4.0 W m−2 for SW (shortwave and less than 1.0 W m−2 for both daytime and nighttime LW (longwave. The global monthly mean instantaneous SW flux from simulated NPP CERES has a low bias of 0.4 W m−2 when compared to simulated Aqua CERES, and the root-mean-square (RMS error is 2.2 W m−2 between them; the biases of daytime and nighttime LW flux are close to zero with RMS errors of 0.8 and 0.2 W m−2. These uncertainties are within the uncertainties of CERES ADMs

  19. Spatiotemporal polarization gradients in phase-bearing light

    International Nuclear Information System (INIS)

    Lembessis, V. E.; Babiker, M.

    2010-01-01

    It is shown how the interference of two circularly polarized laser beams endowed with orbital angular momentum can give rise to spatial and temporal polarization gradients, displaying axial as well as angular symmetry properties. Illustrations are given with reference to circularly polarized Laguerre-Gaussian beams as typical light beams carrying orbital angular momentum.

  20. Platform Constellations

    DEFF Research Database (Denmark)

    Staykova, Kalina Stefanova; Damsgaard, Jan

    2016-01-01

    This research paper presents an initial attempt to introduce and explain the emergence of new phenomenon, which we refer to as platform constellations. Functioning as highly modular systems, the platform constellations are collections of highly connected platforms which co-exist in parallel and a......’ acquisition and users’ engagement rates as well as unlock new sources of value creation and diversify revenue streams....

  1. Linear Magnetoelectric Effect by Orbital Magnetism

    NARCIS (Netherlands)

    Scaramucci, A.; Bousquet, E.; Fechner, M.; Mostovoy, M.; Spaldin, N. A.

    2012-01-01

    We use symmetry analysis and first-principles calculations to show that the linear magnetoelectric effect can originate from the response of orbital magnetic moments to the polar distortions induced by an applied electric field. Using LiFePO4 as a model compound we show that spin-orbit coupling

  2. Orbital transport

    International Nuclear Information System (INIS)

    Oertel, H. Jr.; Koerner, H.

    1993-01-01

    The Third Aerospace Symposium in Braunschweig presented, for the first time, the possibility of bringing together the classical disciplines of aerospace engineering and the natural science disciplines of meteorology and air chemistry in a european setting. In this way, aspects of environmental impact on the atmosphere could be examined quantitatively. An essential finding of the european conference, is the unrestricted agreement of the experts that the given launch frequencies of the present orbital transport result in a negligible amount of pollutants being released in the atmosphere. The symposium does, however, call attention to the increasing need to consider the effect of orbital and atmospheric environmental impact of a future increase in launch frequencies of orbital transport in connection with future space stations. The Third Aerospace Symposium, 'Orbital Transport, Technical, Meteorological and Chemical Aspects', constituted a first forum of discussion for engineers and scientists. Questions of new orbital transport technologies and their environmental impact were to be discussed towards a first consensus. Through the 34 reports and articles, the general problems of space transportation and environmental protection were addressed, as well as particular aspects of high temperatures during reentry in the atmosphere of the earth, precision navigation of flight vehicles or flow behavior and air chemistry in the stratosphere. (orig./CT). 342 figs

  3. South Polar Polygons

    Science.gov (United States)

    2005-01-01

    4 July 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a polgyon-cracked surface, into which deep, somewhat kidney-bean-shaped pits have formed. These are landscapes of the martian south polar residual cap. This view was captured during May 2005. Location near: 86.9oS, 5.1oW Image width: 1.5 km (0.9 mi) Illumination from: upper left Season Southern Spring

  4. Bulk electron spin polarization generated by the spin Hall current

    OpenAIRE

    Korenev, V. L.

    2005-01-01

    It is shown that the spin Hall current generates a non-equilibrium spin polarization in the interior of crystals with reduced symmetry in a way that is drastically different from the previously well-known equilibrium polarization during the spin relaxation process. The steady state spin polarization value does not depend on the strength of spin-orbit interaction offering possibility to generate relatively high spin polarization even in the case of weak spin-orbit coupling.

  5. Bulk electron spin polarization generated by the spin Hall current

    Science.gov (United States)

    Korenev, V. L.

    2006-07-01

    It is shown that the spin Hall current generates a nonequilibrium spin polarization in the interior of crystals with reduced symmetry in a way that is drastically different from the previously well-known “equilibrium” polarization during the spin relaxation process. The steady state spin polarization value does not depend on the strength of spin-orbit interaction offering possibility to generate relatively high spin polarization even in the case of weak spin-orbit coupling.

  6. Energy conversion evolution at lunar polar sites

    Indian Academy of Sciences (India)

    robotic and human surface bases. Sunlight is nearly ... orientation and precession of its spin axis rela- tive to its orbit ... atoms, most likely hydrogen, that many people immediately .... to find out the real meaning of the excess polar hydrogen.

  7. Platform computing

    CERN Multimedia

    2002-01-01

    "Platform Computing releases first grid-enabled workload management solution for IBM eServer Intel and UNIX high performance computing clusters. This Out-of-the-box solution maximizes the performance and capability of applications on IBM HPC clusters" (1/2 page) .

  8. Stable low-altitude orbits around Ganymede considering a disturbing body in a circular orbit

    Science.gov (United States)

    Cardoso dos Santos, J.; Carvalho, J. P. S.; Vilhena de Moraes, R.

    2014-10-01

    Some missions are being planned to visit Ganymede like the Europa Jupiter System Mission that is a cooperation between NASA and ESA to insert the spacecraft JGO (Jupiter Ganymede Orbiter) into Ganymedes orbit. This comprehension of the dynamics of these orbits around this planetary satellite is essential for the success of this type of mission. Thus, this work aims to perform a search for low-altitude orbits around Ganymede. An emphasis is given in polar orbits and it can be useful in the planning of space missions to be conducted around, with respect to the stability of orbits of artificial satellites. The study considers orbits of artificial satellites around Ganymede under the influence of the third-body (Jupiter's gravitational attraction) and the polygenic perturbations like those due to non-uniform distribution of mass (J_2 and J_3) of the main body. A simplified dynamic model for these perturbations is used. The Lagrange planetary equations are used to describe the orbital motion of the artificial satellite. The equations of motion are developed in closed form to avoid expansions in eccentricity and inclination. The results show the argument of pericenter circulating. However, low-altitude (100 and 150 km) polar orbits are stable. Another orbital elements behaved variating with small amplitudes. Thus, such orbits are convenient to be applied to future space missions to Ganymede. Acknowledgments: FAPESP (processes n° 2011/05671-5, 2012/12539-9 and 2012/21023-6).

  9. Prospective Ukrainian lunar orbiter mission

    Science.gov (United States)

    Shkuratov, Y.; Litvinenko, L.; Shulga, V.; Yatskiv, Y.; Kislyuk, V.

    Ukraine has launch vehicles that are able to deliver about 300 kg to the lunar orbit. Future Ukrainian lunar program may propose a polar orbiter. This orbiter should fill principal information gaps in our knowledge about the Moon after Clementine and Lunar Prospector missions and the future missions, like Smart-1, Lunar-A, and Selene. We consider that this can be provided by radar studies of the Moon with supporting optical polarimetric observations from lunar polar orbit. These experiments allow one to better understand global structure of the lunar surface in a wide range of scales, from microns to kilometers. We propose three instruments for the prospective lunar orbiter. They are: a synthetic aperture imaging radar (SAR), ground-penetrating radar (GPR), and imaging polarimeter (IP). The main purpose of SAR is to study with high resolution (50 m) the permanently shadowed sites in the lunar polar regions. These sites are cold traps for volatiles, and have a potential of resource utilization. Possible presence of water ice in the regolith in the sites makes them interesting for permanent manned bases on the Moon. Radar imaging and mapping of other interesting regions could be also planned. Multi-frequencies multi-polarization soun d ing of the lunar surface with GPR can provide information about internal structure of the lunar surface from meters to several hundred meters deep. GPR can be used for measuring the megaregolith layer properties, detection of cryptomaria, and studies of internal structure of the largest craters. IP will be a CCD camera with an additional suite of polarizers. Modest spatial resolution (100 m) should provide a total coverage or a large portion of the lunar surface in oblique viewing basically at large phase angles. Polarization degree at large (>90°) phase angles bears information about characteristic size of the regolith particles. Additional radiophysical experiments are considered with the use of the SAR system, e.g., bistatic radar

  10. Orbit analysis

    International Nuclear Information System (INIS)

    Michelotti, L.

    1995-01-01

    The past fifteen years have witnessed a remarkable development of methods for analyzing single particle orbit dynamics in accelerators. Unlike their more classic counterparts, which act upon differential equations, these methods proceed by manipulating Poincare maps directly. This attribute makes them well matched for studying accelerators whose physics is most naturally modelled in terms of maps, an observation that has been championed most vigorously by Forest. In the following sections the author sketchs a little background, explains some of the physics underlying these techniques, and discusses the best computing strategy for implementing them in conjunction with modeling accelerators

  11. Brane orbits

    CERN Document Server

    Bergshoeff, Eric A; Riccioni, Fabio

    2012-01-01

    We complete the classification of half-supersymmetric branes in toroidally compactified IIA/IIB string theory in terms of representations of the T-duality group. As a by-product we derive a last wrapping rule for the space-filling branes. We find examples of T-duality representations of branes in lower dimensions, suggested by supergravity, of which none of the component branes follow from the reduction of any brane in ten-dimensional IIA/IIB string theory. We discuss the constraints on the charges of half-supersymmetric branes, determining the corresponding T-duality and U-duality orbits.

  12. Orbit analysis

    Energy Technology Data Exchange (ETDEWEB)

    Michelotti, L.

    1995-01-01

    The past fifteen years have witnessed a remarkable development of methods for analyzing single particle orbit dynamics in accelerators. Unlike their more classic counterparts, which act upon differential equations, these methods proceed by manipulating Poincare maps directly. This attribute makes them well matched for studying accelerators whose physics is most naturally modelled in terms of maps, an observation that has been championed most vigorously by Forest. In the following sections the author sketchs a little background, explains some of the physics underlying these techniques, and discusses the best computing strategy for implementing them in conjunction with modeling accelerators.

  13. [Orange Platform].

    Science.gov (United States)

    Toba, Kenji

    2017-07-01

    The Organized Registration for the Assessment of dementia on Nationwide General consortium toward Effective treatment in Japan (ORANGE platform) is a recently established nationwide clinical registry for dementia. This platform consists of multiple registries of patients with dementia stratified by the following clinical stages: preclinical, mild cognitive impairment, early-stage, and advanced-stage dementia. Patients will be examined in a super-longitudinal fashion, and their lifestyle, social background, genetic risk factors, and required care process will be assessed. This project is also notable because the care registry includes information on the successful, comprehensive management of patients with dementia. Therefore, this multicenter prospective cohort study will contribute participants to all clinical trials for Alzheimer's disease as well as improve the understanding of individuals with dementia.

  14. Optimizing the degree of polarization in PETRA

    International Nuclear Information System (INIS)

    Bremer, H.D.; Kewisch, J.; Lewin, H.C.; Mais, H.; Rossmanith, R.; Schmidt, R.; Barber, D.P.

    1982-05-01

    A method is described for compensating the depolarizing effects caused by vertical orbit distortions. The technique has been successfully applied during measurements of beam polarization at PETRA and reproducible polarizations of 70 to 80% have been obtained both in single beam and colliding beam operation. (orig.)

  15. Ellipsometry with randomly varying polarization states

    NARCIS (Netherlands)

    Liu, F.; Lee, C. J.; Chen, J. Q.; E. Louis,; van der Slot, P. J. M.; Boller, K. J.; F. Bijkerk,

    2012-01-01

    We show that, under the right conditions, one can make highly accurate polarization-based measurements without knowing the absolute polarization state of the probing light field. It is shown that light, passed through a randomly varying birefringent material has a well-defined orbit on the Poincar

  16. Polarization developments

    International Nuclear Information System (INIS)

    Prescott, C.Y.

    1993-07-01

    Recent developments in laser-driven photoemission sources of polarized electrons have made prospects for highly polarized electron beams in a future linear collider very promising. This talk discusses the experiences with the SLC polarized electron source, the recent progress with research into gallium arsenide and strained gallium arsenide as a photocathode material, and the suitability of these cathode materials for a future linear collider based on the parameters of the several linear collider designs that exist

  17. Satellite orbits in Levi-Civita space

    Science.gov (United States)

    Humi, Mayer

    2018-03-01

    In this paper we consider satellite orbits in central force field with quadratic drag using two formalisms. The first using polar coordinates in which the satellite angular momentum plays a dominant role. The second is in Levi-Civita coordinates in which the energy plays a central role. We then merge these two formalisms by introducing polar coordinates in Levi-Civita space and derive a new equation for satellite orbits which unifies these two paradigms. In this equation energy and angular momentum appear on equal footing and thus characterize the orbit by its two invariants. Using this formalism we show that equatorial orbits around oblate spheroids can be expressed analytically in terms of Elliptic functions. In the second part of the paper we derive in Levi-Civita coordinates a linearized equation for the relative motion of two spacecrafts whose trajectories are in the same plane. We carry out also a numerical verification of these equations.

  18. Stratospheric Platforms for Monitoring Purposes

    International Nuclear Information System (INIS)

    Konigorski, D.; Gratzel, U.; Obersteiner, M.; Schneidereit, M.

    2010-01-01

    ) incrementally, e.g. by deploying additional High Altitude Platforms (HAPs); Ability to service / update / reconfigure payload; Close range - for both monitoring and communications: 1. Monitoring from e.g. 20 km distance, compared with about 450 km for a Low Earth Orbit (LEO) satellite. Furthermore the platforms facilitate very high spatial resolution. 2. Extremely high overall payload and power capacity and can replace extensive ground infrastructure (e.g. telecoms masts); Stratospheric platforms can also make use of low temperatures (superconducting), large antennas (high resolution), less atmosphere (high power microwave) and energy collection and transmission (electric power support of high altitude UAVs). The paper will discuss the potential of stratospheric platforms for safeguards applications. (author)

  19. Neutron polarization

    International Nuclear Information System (INIS)

    Firk, F.W.K.

    1976-01-01

    Some recent experiments involving polarized neutrons are discussed; they demonstrate how polarization studies provide information on fundamental aspects of nuclear structure that cannot be obtained from more traditional neutron studies. Until recently, neutron polarization studies tended to be limited either to very low energies or to restricted regions at higher energies, determined by the kinematics of favorable (p, vector n) and (d, vector n) reactions. With the advent of high intensity pulsed electron and proton accelerators and of beams of vector polarized deuterons, this is no longer the case. One has entered an era in which neutron polarization experiments are now being carried out, in a routine way, throughout the entire range from thermal energies to tens-of-MeV. The significance of neutron polarization studies is illustrated in discussions of a wide variety of experiments that include the measurement of T-invariance in the β-decay of polarized neutrons, a search for the effects of meson exchange currents in the photo-disintegration of the deuteron, the determination of quantum numbers of states in the fission of aligned 235 U and 237 Np induced by polarized neutrons, and the double- and triple-scattering of fast neutrons by light nuclei

  20. Polarization holography

    DEFF Research Database (Denmark)

    Nikolova, L.; Ramanujam, P.S.

    Current research into holography is concerned with applications in optically storing, retrieving, and processing information. Polarization holography has many unique properties compared to conventional holography. It gives results in high efficiency, achromaticity, and special polarization...... properties. This books reviews the research carried out in this field over the last 15 years. The authors provide basic concepts in polarization and the propagation of light through anisotropic materials, before presenting a sound theoretical basis for polarization holography. The fabrication...... and characterization of azobenzene based materials, which remain the most efficient for the purpose, is described in detail. This is followed by a description of other materials that are used in polarization holography. An in-depth description of various applications, including display holography and optical storage...

  1. Ionic polarization

    International Nuclear Information System (INIS)

    Mahan, G.D.

    1992-01-01

    Ferroelectricity occurs in many different kinds of materials. Many of the technologically important solids, which are ferroelectric, can be classified as ionic. Any microscopic theory of ferroelectricity must contain a description of local polarization forces. We have collaborated in the development of a theory of ionic polarization which is quite successful. Its basic assumption is that the polarization is derived from the properties of the individual ions. We have applied this theory successfully to diverse subjects as linear and nonlinear optical response, phonon dispersion, and piezoelectricity. We have developed numerical methods using the local Density approximation to calculate the multipole polarizabilities of ions when subject to various fields. We have also developed methods of calculating the nonlinear hyperpolarizability, and showed that it can be used to explain light scattering experiments. This paper elaborates on this polarization theory

  2. Polarization experiments

    International Nuclear Information System (INIS)

    Halzen, F.

    1977-02-01

    In a theoretical review of polarization experiments two important points are emphasized: (a) their versatility and their relevance to a large variety of aspects of hadron physics (tests of basic symmetries; a probe of strong interaction dynamics; a tool for hadron spectroscopy); (b) the wealth of experimental data on polarization parameters in pp and np scattering in the Regge language and in the diffraction language. (author)

  3. Optically induced rotation of Rayleigh particles by vortex beams with different states of polarization

    International Nuclear Information System (INIS)

    Li, Manman; Yan, Shaohui; Yao, Baoli; Liang, Yansheng; Lei, Ming; Yang, Yanlong

    2016-01-01

    Optical vortex beams carry optical orbital angular momentum (OAM) and can induce an orbital motion of trapped particles in optical trapping. We show that the state of polarization (SOP) of vortex beams will affect the details of this optically induced orbital motion to some extent. Numerical results demonstrate that focusing the vortex beams with circular, radial or azimuthal polarizations can induce a uniform orbital motion on a trapped Rayleigh particle, while in the focal field of the vortex beam with linear polarization the particle experiences a non-uniform orbital motion. Among the formers, the vortex beam with circular polarization induces a maximum optical torque on the particle. Furthermore, by varying the topological charge of the vortex beams, the vortex beam with circular polarization gives rise to an optimum torque superior to those given by the other three vortex beams. These facts suggest that the circularly polarized vortex beam is more suitable for rotating particles. - Highlights: • States of polarization of vortex beams affect the optically induced orbital motion of particles. • The dependences of the force and orbital torque on the topological charge, the size and the absorptivity of particles were calculated. • Focused vortex beams with circular, radial or azimuthal polarizations induce a uniform orbital motion on particles. • Particles experience a non-uniform orbital motion in the focused linearly polarized vortex beam. • The circularly polarized vortex beam is a superior candidate for rotating particles.

  4. Polarization measurement for internal polarized gaseous targets

    International Nuclear Information System (INIS)

    Ye Zhenyu; Ye Yunxiu; Lv Haijiang; Mao Yajun

    2004-01-01

    The authors present an introduction to internal polarized gaseous targets, polarization method, polarization measurement method and procedure. To get the total nuclear polarization of hydrogen atoms (including the polarization of the recombined hydrogen molecules) in the target cell, authors have measured the parameters relating to atomic polarization and polarized hydrogen atoms and molecules. The total polarization of the target during our measurement is P T =0.853 ± 0.036. (authors)

  5. Anomalous Hall conductivity: Local orbitals approach

    Czech Academy of Sciences Publication Activity Database

    Středa, Pavel

    2010-01-01

    Roč. 82, č. 4 (2010), 045115/1-045115/9 ISSN 1098-0121 Institutional research plan: CEZ:AV0Z10100521 Keywords : anomalous Hall effect * Berry phase correction * orbital polarization momentum Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.772, year: 2010

  6. ERS orbit control

    Science.gov (United States)

    Rosengren, Mats

    1991-12-01

    The European remote sensing mission orbit control is addressed. For the commissioning phase, the orbit is defined by the following requirements: Sun synchronous, local time of descending node 10:30; three days repeat cycle with 43 orbital revolutions; overhead Venice tower (12.508206 deg east, 45.314222 deg north). The launch, maneuvers for the initial acquisition of the operational orbit, orbit maintenance maneuvers, evaluation of the orbit control, and the drift of the inclination are summarized.

  7. POLARIZED BEAMS: 2 - Partial Siberian Snake rescues polarized protons at Brookhaven

    International Nuclear Information System (INIS)

    Huang, Haixin

    1994-01-01

    To boost the level of beam polarization (spin orientation), a partial 'Siberian Snake' was recently used to overcome imperfection depolarizing resonances in the Brookhaven Alternating Gradient Synchrotron (AGS). This 9-degree spin rotator recently permitted acceleration with no noticeable polarization loss. The intrinsic AGS depolarizing resonances (which degrade the polarization content) had been eliminated by betatron tune jumps, but the imperfection resonances were compensated by means of harmonic orbit corrections. However, at high energies these orbit corrections are difficult and tedious and a Siberian Snake became an attractive alternative

  8. The Viking Orbiter and its Mariner inheritance

    Science.gov (United States)

    Wolfe, A. E.; Norris, H. W.

    1975-01-01

    The orbiter system of the Viking spacecraft performs the functions of transporting the lander into orbit around Mars, surveying the proposed landing sites, relaying lander data to earth, and conducting independent scientific observations of Mars. The orbiter system is a semiautomatic, solar-powered, triaxially stabilized platform capable of making trajectory corrections and communicating with earth on S-band. Its instruments for visual imaging, detecting water vapor, and thermal mapping are mounted on a separate two-degree-of-freedom scan platform. Radio science is conducted at three frequencies, using the main S-band system, a separate X-band derived from the S-band, and the UHF one-way link with the lander.

  9. Mars orbiter redirected in bid to find Beagle

    CERN Multimedia

    2003-01-01

    "Mission controllers in Darmstadt, Germany, have successfully redirected Europe's Mars Express orbiter into a polar orbit, putting it on course for a last-ditch attempt to contact Beagle 2, the lander that has been missing since Christmas day when it should have touched down on the red planet" (1/2 page).

  10. Sources of polarized neutrons

    International Nuclear Information System (INIS)

    Walter, L.

    1983-01-01

    Various sources of polarized neutrons are reviewed. Monoenergetic source produced with unpolarized or polarized beams, white sources of polarized neutrons, production by transmissions through polarized hydrogen targets and polarized thermal neutronsare discussed, with appropriate applications included. (U.K.)

  11. Lunar true polar wander inferred from polar hydrogen.

    Science.gov (United States)

    Siegler, M A; Miller, R S; Keane, J T; Laneuville, M; Paige, D A; Matsuyama, I; Lawrence, D J; Crotts, A; Poston, M J

    2016-03-24

    The earliest dynamic and thermal history of the Moon is not well understood. The hydrogen content of deposits near the lunar poles may yield insight into this history, because these deposits (which are probably composed of water ice) survive only if they remain in permanent shadow. If the orientation of the Moon has changed, then the locations of the shadowed regions will also have changed. The polar hydrogen deposits have been mapped by orbiting neutron spectrometers, and their observed spatial distribution does not match the expected distribution of water ice inferred from present-day lunar temperatures. This finding is in contrast to the distribution of volatiles observed in similar thermal environments at Mercury's poles. Here we show that polar hydrogen preserves evidence that the spin axis of the Moon has shifted: the hydrogen deposits are antipodal and displaced equally from each pole along opposite longitudes. From the direction and magnitude of the inferred reorientation, and from analysis of the moments of inertia of the Moon, we hypothesize that this change in the spin axis, known as true polar wander, was caused by a low-density thermal anomaly beneath the Procellarum region. Radiogenic heating within this region resulted in the bulk of lunar mare volcanism and altered the density structure of the Moon, changing its moments of inertia. This resulted in true polar wander consistent with the observed remnant polar hydrogen. This thermal anomaly still exists and, in part, controls the current orientation of the Moon. The Procellarum region was most geologically active early in lunar history, which implies that polar wander initiated billions of years ago and that a large portion of the measured polar hydrogen is ancient, recording early delivery of water to the inner Solar System. Our hypothesis provides an explanation for the antipodal distribution of lunar polar hydrogen, and connects polar volatiles to the geologic and geophysical evolution of the Moon

  12. CONGENITAL ORBITAL TERATOMA

    African Journals Online (AJOL)

    was done without contrast and 3mm/5mm/10mm slices were obtained to cover the orbit, skull base and brain. The findings included a soft tissue mass arising from the orbit. The left eye ball was extra orbital. There was no defect .... love's Short Practice of Surgery. 7 Edition,. Levis London, 1997; 45-64. 2. Orbital tumor Part 1, ...

  13. Verification of possible asymmetry of polarization of thermal neutrons reflected by a mirror

    International Nuclear Information System (INIS)

    Okorokov, A.I.; Runov, V.V.; Gukasov, A.G.; Shchebetov, A.F.

    1976-01-01

    Experiments with a polarizing neutron guide do not confirm the neutron polarization asymmetry observed previously by Berndorfer for neutrons traversing a polarizing neutron guide. In connection with the spin-orbit effects a verification is carried out on single reflection of neutrons by magnetic or nonmagnetic mirrors. With an accuracy of 10 -4 -10 -3 no polarization asymmetry is observed

  14. Radiovolumetry of the orbit

    International Nuclear Information System (INIS)

    Abujamra, S.

    1983-01-01

    The authors present a method called ''Radiovolumetry of the orbit'' that permits the evaluation of the orbital volume from anteroposterior skull X-Rays (CALDWELL 30 0 position). The research was based in the determination of the orbital volume with lead spheres, in 1010 orbits of 505 dry skulls of Anatomy Museums. After the dry skulls was X-rayed six frontal orbital diameters were made, with care to correct the radiographic amplification. PEARSON correlation coeficient test was applied between the mean orbital diameter and the orbital volume. The result was r = 0,8 with P [pt

  15. Spin-Orbit Coupling for Photons and Polaritons in Microstructures

    Directory of Open Access Journals (Sweden)

    V. G. Sala

    2015-03-01

    Full Text Available We use coupled micropillars etched out of a semiconductor microcavity to engineer a spin-orbit Hamiltonian for photons and polaritons in a microstructure. The coupling between the spin and orbital momentum arises from the polarization-dependent confinement and tunneling of photons between adjacent micropillars arranged in the form of a hexagonal photonic molecule. It results in polariton eigenstates with distinct polarization patterns, which are revealed in photoluminescence experiments in the regime of polariton condensation. Thanks to the strong polariton nonlinearities, our system provides a photonic workbench for the quantum simulation of the interplay between interactions and spin-orbit effects, particularly when extended to two-dimensional lattices.

  16. Polarization study

    International Nuclear Information System (INIS)

    Nurushev, S.B.

    1989-01-01

    Brief review is presented of the high energy polarization study including experimental data and the theoretical descriptions. The mostimportant proposals at the biggest accelerators and the crucial technical developments are also listed which may become a main-line of spin physics. 35 refs.; 10 figs.; 4 tabs

  17. Polarization in free electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Papadichev, V.A. [Lebedev Physical Institute, Moscow (Russian Federation)

    1995-12-31

    Polarization of electromagnetic radiation is required very often in numerous scientific and industrial applications: studying of crystals, molecules and intermolecular interaction high-temperature superconductivity, semiconductors and their transitions, polymers and liquid crystals. Using polarized radiation allows to obtain important data (otherwise inaccessible) in astrophysics, meteorology and oceanology. It is promising in chemistry and biology for selective influence on definite parts of molecules in chain synthesis reactions, precise control of various processes at cell and subcell levels, genetic engineering etc. Though polarization methods are well elaborated in optics, they can fail in far-infrared, vacuum-ultraviolet and X-ray regions because of lack of suitable non-absorbing materials and damaging of optical elements at high specific power levels. Therefore, it is of some interest to analyse polarization of untreated FEL radiation obtained with various types of undulators, with and without axial magnetic field. The polarization is studied using solutions for electron orbits in various cases: plane or helical undulator with or without axial magnetic field, two plane undulators, a combination of right- and left-handed helical undulators with equal periods, but different field amplitudes. Some examples of how a desired polarization (elliptical circular or linear) can be obtained or changed quickly, which is necessary in many experiments, are given.

  18. Spin tune dependence on closed orbit in RHIC

    International Nuclear Information System (INIS)

    Ptitsyn, V.; Bai, M.; Roser, T.

    2010-01-01

    Polarized proton beams are accelerated in RHIC to 250 GeV energy with the help of Siberian Snakes. The pair of Siberian Snakes in each RHIC ring holds the design spin tune at 1/2 to avoid polarization loss during acceleration. However, in the presence of closed orbit errors, the actual spin tune can be shifted away from the exact 1/2 value. It leads to a corresponding shift of locations of higher-order ('snake') resonances and limits the available betatron tune space. The largest closed orbit effect on the spin tune comes from the horizontal orbit angle between the two snakes. During RHIC Run in 2009 dedicated measurements with polarized proton beams were taken to verify the dependence of the spin tune on the local orbits at the Snakes. The experimental results are presented along with the comparison with analytical predictions.

  19. North Polar Cap

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour. In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime. The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap. Image information: VIS instrument. Latitude 86.5, Longitude 64.5 East (295.5 West). 40 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen

  20. The status of polarization studies at HERA

    International Nuclear Information System (INIS)

    Boege, M.

    1993-01-01

    In August 1992 a vertical electron beam polarization of nearly 60% at 26.7 GeV (spin tune=60.5) was obtained at HERA. This was achieved by optimizing the energy and orbit tunes and by applying harmonic corrections to the closed orbit. The polarization level was reproducible from fill to fill and the calibration of the Compton polarimeter was confirmed by measuring the polarization build up curve. The polarization measurements were made with currents of one to two milliamps. Much higher currents are expected for the 1993 luminosity run (∼ 30 mA were obtained in May 1993). The high polarization level was reproduced at high current. Further polarization studies in parallel with e-p operation are planned. In 1993/94 a pair of spin rotators will be installed in the East straight section so that longitudinal polarization is available at the East interaction point. Simulations with the spin tracking program SITROS are in qualitative agreement with the measurements. Calculations with SITROS show that longitudinal polarizations of up to 50% could then still be achieved

  1. Viking orbiter and its Mariner inheritance

    Science.gov (United States)

    1984-01-01

    Improvements to the design of the Mariner spacecraft resulted in the Viking spacecraft. The Viking spacecraft would consist of two major systems - an orbiter and a lander, while the lander would provide the means for safely delivering the scientific instruments to the surface, house, and provide the necessary power source and communication links for those experiments, the orbiter would transport the lander to Mars, rovide a platform for the Viking imaging system so that proposed landing sites could be surveyed and certified, relay lander science information back to Earth, and conduct scientific observations in its own right.

  2. Traumatic orbital CSF leak

    Science.gov (United States)

    Borumandi, Farzad

    2013-01-01

    Compared to the cerebrospinalfluid (CSF) leak through the nose and ear, the orbital CSF leak is a rare and underreported condition following head trauma. We present the case of a 49-year-old woman with oedematous eyelid swelling and ecchymosis after a seemingly trivial fall onto the right orbit. Apart from the above, she was clinically unremarkable. The CT scan revealed a minimally displaced fracture of the orbital roof with no emphysema or intracranial bleeding. The fractured orbital roof in combination with the oedematous eyelid swelling raised the suspicion for orbital CSF leak. The MRI of the neurocranium demonstrated a small-sized CSF fistula extending from the anterior cranial fossa to the right orbit. The patient was treated conservatively and the lid swelling resolved completely after 5 days. Although rare, orbital CSF leak needs to be included in the differential diagnosis of periorbital swelling following orbital trauma. PMID:24323381

  3. Orbital parameters of extrasolar planets derived from polarimetry

    Science.gov (United States)

    Fluri, D. M.; Berdyugina, S. V.

    2010-03-01

    Context. Polarimetry of extrasolar planets becomes a new tool for their investigation, which requires the development of diagnostic techniques and parameter case studies. Aims: Our goal is to develop a theoretical model which can be applied to interpret polarimetric observations of extrasolar planets. Here we present a theoretical parameter study that shows the influence of the various involved parameters on the polarization curves. Furthermore, we investigate the robustness of the fitting procedure. We focus on the diagnostics of orbital parameters and the estimation of the scattering radius of the planet. Methods: We employ the physics of Rayleigh scattering to obtain polarization curves of an unresolved extrasolar planet. Calculations are made for two cases: (i) assuming an angular distribution for the intensity of the scattered light as from a Lambert sphere and for polarization as from a Rayleigh-type scatterer; and (ii) assuming that both the intensity and polarization of the scattered light are distributed according to the Rayleigh law. We show that the difference between these two cases is negligible for the shapes of the polarization curves. In addition, we take the size of the host star into account, which is relevant for hot Jupiters orbiting giant stars. Results: We discuss the influence of the inclination of the planetary orbit, the position angle of the ascending node, and the eccentricity on the linearly polarized light curves both in Stokes Q/I and U/I. We also analyze errors that arise from the assumption of a point-like star in numerical modeling of polarization as compared to consistent calculations accounting for the finite size of the host star. We find that errors due to the point-like star approximation are reduced with the size of the orbit, but still amount to about 5% for known hot Jupiters. Recovering orbital parameters from simulated data is shown to be very robust even for very noisy data because the polarization curves react

  4. Eye and orbital cavity

    International Nuclear Information System (INIS)

    Panfilova, G.V.; Koval', G.Yu.

    1984-01-01

    Radioanatomy of eyes and orbit is described. Diseases of the orbit (developmental anomalies, inflammatory diseases, lacrimal apparatus deseases, toxoplasmosis, tumors and cysts et al.), methods of foreign body localization in the eye are considered. Roentgenograms of the orbit and calculation table for foreign body localization in spherical eyes of dissimilar diameter are presented

  5. Introducing Earth's Orbital Eccentricity

    Science.gov (United States)

    Oostra, Benjamin

    2015-01-01

    Most students know that planetary orbits, including Earth's, are elliptical; that is Kepler's first law, and it is found in many science textbooks. But quite a few are mistaken about the details, thinking that the orbit is very eccentric, or that this effect is somehow responsible for the seasons. In fact, the Earth's orbital eccentricity is…

  6. Application of circular polarized synchrotron radiation

    International Nuclear Information System (INIS)

    Miyahara, Tsuneaki; Kawata, Hiroshi

    1988-03-01

    The idea of using the polarizing property of light for physical experiment by controlling it variously has been known from old time, and the Faraday effect and the research by polarizing microscopy are its examples. The light emitted from the electron orbit of an accelerator has the different polarizing characteristics from those of the light of a laboratory light source, and as far as observing it within the electron orbit plane, it becomes linearly polarized light. By utilizing this property well, research is carried out at present in synchrotron experimental facilities. Recently, the technology related to the insert type light cources using permanent magnets has advanced remarkably, and circular polarized light has become to be producible. If the light like this can be obtained with the energy not only in far ultraviolet region but also to x-ray region at high luminance, new possibility should open. At the stage that the design of an insert type light source was finished, and its manufacture was started, the research on the method of evaluating the degree of circular polarization and the research on the utilization of circular polarized synchrotron radiation are earnestly carried out. In this report, the results of researches presented at the study meeting are summarized. Moreover, the design and manufacture of the beam lines for exclusive use will be carried out. (Kako, I.)

  7. PALOMA: A Magnetic CV between Polars and Intermediate Polars

    Science.gov (United States)

    Joshi, Arti; Pandey, J. C.; Singh, K. P.; Agrawal, P. C.

    2016-10-01

    We present analyses of archival X-ray data obtained from the XMM-Newton satellite and optical photometric data obtained from 1 m class telescopes of ARIES, Nainital of a magnetic cataclysmic variable (MCV) Paloma. Two persistent periods at 156 ± 1 minutes and 130 ± 1 minutes are present in the X-ray data, which we interpret as the orbital and spin periods, respectively. These periods are similar to those obtained from the previous as well as new optical photometric observations. The soft-X-ray excess seen in the X-ray spectrum of Paloma and the averaged X-ray spectra are well fitted by two-temperature plasma models with temperatures of {0.10}-0.01+0.02 and {13.0}-0.5+0.5 keV with an Fe Kα line and an absorbing column density of 4.6 × 1022 cm-2. This material partially covers 60 ± 2% of the X-ray source. We also present the orbital and spin-phase-resolved spectroscopy of Paloma in the 0.3{--}10.0 {keV} energy band and find that the X-ray spectral parameters show orbital and spin-phase dependencies. New results obtained from optical and X-ray studies of Paloma indicate that it belongs to a class of a few magnetic CVs that seem to have the characteristics of both the polars and the intermediate polars.

  8. Lunar Reconnaissance Orbiter Camera (LROC) instrument overview

    Science.gov (United States)

    Robinson, M.S.; Brylow, S.M.; Tschimmel, M.; Humm, D.; Lawrence, S.J.; Thomas, P.C.; Denevi, B.W.; Bowman-Cisneros, E.; Zerr, J.; Ravine, M.A.; Caplinger, M.A.; Ghaemi, F.T.; Schaffner, J.A.; Malin, M.C.; Mahanti, P.; Bartels, A.; Anderson, J.; Tran, T.N.; Eliason, E.M.; McEwen, A.S.; Turtle, E.; Jolliff, B.L.; Hiesinger, H.

    2010-01-01

    The Lunar Reconnaissance Orbiter Camera (LROC) Wide Angle Camera (WAC) and Narrow Angle Cameras (NACs) are on the NASA Lunar Reconnaissance Orbiter (LRO). The WAC is a 7-color push-frame camera (100 and 400 m/pixel visible and UV, respectively), while the two NACs are monochrome narrow-angle linescan imagers (0.5 m/pixel). The primary mission of LRO is to obtain measurements of the Moon that will enable future lunar human exploration. The overarching goals of the LROC investigation include landing site identification and certification, mapping of permanently polar shadowed and sunlit regions, meter-scale mapping of polar regions, global multispectral imaging, a global morphology base map, characterization of regolith properties, and determination of current impact hazards.

  9. Hydrogen Distribution in the Lunar Polar Regions

    Science.gov (United States)

    Sanin, A. B.; Mitrofanov, I. G.; Litvak, M. L.; Bakhtin, B. N.; Bodnarik, J. G.; Boynton, W. V.; Chin, G.; Evans, L. G.; Harshmann, K.; Fedosov, F.; hide

    2016-01-01

    We present a method of conversion of the lunar neutron counting rate measured by the Lunar Reconnaissance Orbiter (LRO) Lunar Exploration Neutron Detector (LEND) instrument collimated neutron detectors, to water equivalent hydrogen (WEH) in the top approximately 1 m layer of lunar regolith. Polar maps of the Moon’s inferred hydrogen abundance are presented and discussed.

  10. Strategic Polarization.

    Science.gov (United States)

    Kalai, Adam; Kalai, Ehud

    2001-08-01

    In joint decision making, similarly minded people may take opposite positions. Consider the example of a marriage in which one spouse gives generously to charity while the other donates nothing. Such "polarization" may misrepresent what is, in actuality, a small discrepancy in preferences. It may be that the donating spouse would like to see 10% of their combined income go to charity each year, while the apparently frugal spouse would like to see 8% donated. A simple game-theoretic analysis suggests that the spouses will end up donating 10% and 0%, respectively. By generalizing this argument to a larger class of games, we provide strategic justification for polarization in many situations such as debates, shared living accommodations, and disciplining children. In some of these examples, an arbitrarily small disagreement in preferences leads to an arbitrarily large loss in utility for all participants. Such small disagreements may also destabilize what, from game-theoretic point of view, is a very stable equilibrium. Copyright 2001 Academic Press.

  11. Nontraumatic orbital roof encephalocele.

    Science.gov (United States)

    Hoang, Amber; Maugans, Todd; Ngo, Thang; Ikeda, Jamie

    2017-02-01

    Intraorbital meningoencephaloceles occur most commonly as a complication of traumatic orbital roof fractures. Nontraumatic congenital orbital meningoncephaloceles are very rare, with most secondary to destructive processes affecting the orbit and primary skull defects. Treatment for intraorbital meningoencephaloceles is surgical repair, involving the excision of herniated brain parenchyma and meninges and reconstruction of the osseous defect. Most congenital lesions present in infancy with obvious globe and orbital deformities; we report an orbital meningoencephalocele in a 3-year-old girl who presented with ptosis. Copyright © 2017 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  12. Deadly Sunflower Orbits

    Science.gov (United States)

    Hamilton, Douglas P.

    2018-04-01

    Solar radiation pressure is usually very effective at removing hazardous millimeter-sized debris from distant orbits around asteroidsand other small solar system bodies (Hamilton and Burns 1992). Theprimary loss mechanism, driven by the azimuthal component of radiationpressure, is eccentricity growth followed by a forced collision withthe central body. One large class of orbits, however, neatly sidestepsthis fate. Orbits oriented nearly perpendicular to the solar directioncan maintain their face-on geometry, oscillating slowly around a stableequilibrium orbit. These orbits, designated sunflower orbits, arerelated to terminator orbits studied by spacecraft mission designers(Broschart etal. 2014).Destabilization of sunflower orbits occurs only for particles smallenough that radiation pressure is some tens of percent the strength ofthe central body's direct gravity. This greatly enhanced stability,which follows from the inability of radiation incident normal to theorbit to efficiently drive eccentricities, presents a threat tospacecraft missions, as numerous dangerous projectiles are potentiallyretained in orbit. We have investigated sunflower orbits insupport of the New Horizons, Aida, and Lucy missions and find thatthese orbits are stable for hazardous particle sizes at asteroids,comets, and Kuiper belt objects of differing dimensions. Weinvestigate the sources and sinks for debris that might populate suchorbits, estimate timescales and equilibrium populations, and willreport on our findings.

  13. Orbital fractures: a review

    Directory of Open Access Journals (Sweden)

    Jeffrey M Joseph

    2011-01-01

    Full Text Available Jeffrey M Joseph, Ioannis P GlavasDivision of Ophthalmic Plastic and Reconstructive Surgery, Department of Ophthalmology, School of Medicine, New York University, New York, NY, USA; Manhattan Eye, Ear, and Throat Hospital, New York, NY, USAAbstract: This review of orbital fractures has three goals: 1 to understand the clinically relevant orbital anatomy with regard to periorbital trauma and orbital fractures, 2 to explain how to assess and examine a patient after periorbital trauma, and 3 to understand the medical and surgical management of orbital fractures. The article aims to summarize the evaluation and management of commonly encountered orbital fractures from the ophthalmologic perspective and to provide an overview for all practicing ophthalmologists and ophthalmologists in training.Keywords: orbit, trauma, fracture, orbital floor, medial wall, zygomatic, zygomatic complex, zmc fracture, zygomaticomaxillary complex fractures 

  14. Spin-orbit beams for optical chirality measurement

    Science.gov (United States)

    Samlan, C. T.; Suna, Rashmi Ranjan; Naik, Dinesh N.; Viswanathan, Nirmal K.

    2018-01-01

    Accurate measurement of chirality is essential for the advancement of natural and pharmaceutical sciences. We report here a method to measure chirality using non-separable states of light with geometric phase-gradient in the circular polarization basis, which we refer to as spin-orbit beams. A modified polarization Sagnac interferometer is used to generate spin-orbit beams wherein the spin and orbital angular momentum of the input Gaussian beam are coupled. The out-of-phase interference between counter-propagating Gaussian beams with orthogonal spin states and lateral-shear or/and linear-phase difference between them results in spin-orbit beams with linear and azimuthal phase gradient. The spin-orbit beams interact efficiently with the chiral medium, inducing a measurable change in the center-of-mass of the beam, using the polarization rotation angle and hence the chirality of the medium are accurately calculated. Tunable dynamic range of measurement and flexibility to introduce large values of orbital angular momentum for the spin-orbit beam, to improve the measurement sensitivity, highlight the techniques' versatility.

  15. Long-period polar rain variations, solar wind and hemispherically symmetric polar rain

    International Nuclear Information System (INIS)

    Makita, K.; Meng, C.

    1987-01-01

    On the basic of electron data obtained by the Defense Meteorological Satellite Program (DMSP) F2 satellite the long-period variations of the polar rain flux are examined for four consecutive solar rotations. It is clearly demonstrated that the asymmetric enhancement of the polar rain flux is strongly controlled by the sector structure of the interplanetary magnetic field (IMF). However, the orbit-to-orbit and day-to-day variations of the polar rain flux are detected even during a very stable sector period, and the polar rain flux does not have any clear relationship to the magnitude of the IMF B/sub x/ or B/sub y/. Thus the polarity of B/sub x/ controls only the accessibility of a polar region. It is also noticed that the intensity of polar rain fluxes does not show any relationship to the density of the solar wind, suggesting that the origin of the polar rain electrons is different from the commonly observed part of the solar wind electron distribution function. In addition to the asymmetric polar rain distribution, increasing polar rain fluxes of similar high intensity are sometimes detected over both polar caps. An examination of more than 1 year's data from the DMSP F2 and F4 satellites shows that simultaneous intense uniform precipitations (>10 7 electrons/cm 2 s sr) over both polar caps are not coincidental; it also shows that the spectra are similar. The occurrence of hemispherically symmetric events is not common. They generally are observed after an IMF sector transition period, during unstable periods in the sector structure, and while the solar wind density is high. copyright American Geophysical Union 1987

  16. Wide-band polarization controller for Si photonic integrated circuits.

    Science.gov (United States)

    Velha, P; Sorianello, V; Preite, M V; De Angelis, G; Cassese, T; Bianchi, A; Testa, F; Romagnoli, M

    2016-12-15

    A circuit for the management of any arbitrary polarization state of light is demonstrated on an integrated silicon (Si) photonics platform. This circuit allows us to adapt any polarization into the standard fundamental TE mode of a Si waveguide and, conversely, to control the polarization and set it to any arbitrary polarization state. In addition, the integrated thermal tuning allows kilohertz speed which can be used to perform a polarization scrambler. The circuit was used in a WDM link and successfully used to adapt four channels into a standard Si photonic integrated circuit.

  17. Polarized secondary radioactive beams

    International Nuclear Information System (INIS)

    Zaika, N.I.

    1992-01-01

    Three methods of polarized radioactive nuclei beam production: a) a method nuclear interaction of the non-polarized or polarized charged projectiles with target nuclei; b) a method of polarization of stopped reaction radioactive products in a special polarized ion source with than following acceleration; c) a polarization of radioactive nuclei circulating in a storage ring are considered. Possible life times of the radioactive ions for these methods are determined. General schemes of the polarization method realizations and depolarization problems are discussed

  18. Product Platform Performance

    DEFF Research Database (Denmark)

    Munk, Lone

    The aim of this research is to improve understanding of platform-based product development by studying platform performance in relation to internal effects in companies. Platform-based product development makes it possible to deliver product variety and at the same time reduce the needed resources...... engaging in platform-based product development. Similarly platform assessment criteria lack empirical verification regarding relevance and sufficiency. The thesis focuses on • the process of identifying and estimating internal effects, • verification of performance of product platforms, (i...... experienced representatives from the different life systems phase systems of the platform products. The effects are estimated and modeled within different scenarios, taking into account financial and real option aspects. The model illustrates and supports estimation and quantification of internal platform...

  19. An interstellar origin for Jupiter's retrograde co-orbital asteroid

    Science.gov (United States)

    Namouni, F.; Morais, M. H. M.

    2018-06-01

    Asteroid (514107) 2015 BZ509 was discovered recently in Jupiter's co-orbital region with a retrograde motion around the Sun. The known chaotic dynamics of the outer Solar system have so far precluded the identification of its origin. Here, we perform a high-resolution statistical search for stable orbits and show that asteroid (514107) 2015 BZ509 has been in its current orbital state since the formation of the Solar system. This result indicates that (514107) 2015 BZ509 was captured from the interstellar medium 4.5 billion years in the past as planet formation models cannot produce such a primordial large-inclination orbit with the planets on nearly coplanar orbits interacting with a coplanar debris disc that must produce the low-inclination small-body reservoirs of the Solar system such as the asteroid and Kuiper belts. This result also implies that more extrasolar asteroids are currently present in the Solar system on nearly polar orbits.

  20. Polar crane

    International Nuclear Information System (INIS)

    Makosinski, S.

    1981-01-01

    In many applications polar cranes have to be repeatedly positioned with high accuracy. A guidance system is disclosed which has two pairs of guides. Each guide consists of two rollers carried by a sheave rotatable mounted on the crane bridge, the rollers being locatable one on each side of a guideway, e.g. the circular track on which the bridge runs. The pairs of guides are interconnected by respective rope loops which pass around and are locked to the respective pairs of sheaves in such a manner that movement of one guide results in equal movement of the other guide in a sense to maintain the repeatability of positioning of the centre of the bridge. A hydraulically-linked guide system is also described. (author)

  1. Mobile platform security

    CERN Document Server

    Asokan, N; Dmitrienko, Alexandra

    2013-01-01

    Recently, mobile security has garnered considerable interest in both the research community and industry due to the popularity of smartphones. The current smartphone platforms are open systems that allow application development, also for malicious parties. To protect the mobile device, its user, and other mobile ecosystem stakeholders such as network operators, application execution is controlled by a platform security architecture. This book explores how such mobile platform security architectures work. We present a generic model for mobile platform security architectures: the model illustrat

  2. Data Platforms and Cities

    DEFF Research Database (Denmark)

    Blok, Anders; Courmont, Antoine; Hoyng, Rolien

    2017-01-01

    This section offers a series of joint reflections on (open) data platform from a variety of cases, from cycling, traffic and mapping to activism, environment and data brokering. Data platforms play a key role in contemporary urban governance. Linked to open data initiatives, such platforms are of...

  3. Dynamic Gaming Platform (DGP)

    Science.gov (United States)

    2009-04-01

    GAMING PLATFORM (DGP) Lockheed Martin Corporation...YYYY) APR 09 2. REPORT TYPE Final 3. DATES COVERED (From - To) Jul 07 – Mar 09 4. TITLE AND SUBTITLE DYNAMIC GAMING PLATFORM (DGP) 5a...CMU Carnegie Mellon University DGP Dynamic Gaming Platform GA Genetic Algorithm IARPA Intelligence Advanced Research Projects Activity LM ATL Lockheed Martin Advanced Technology Laboratories PAINT ProActive INTelligence

  4. ITS Platform North Denmark

    DEFF Research Database (Denmark)

    Lahrmann, Harry; Agerholm, Niels; Juhl, Jens

    2012-01-01

    This paper presents the project entitled “ITS Platform North Denmark” which is used as a test platform for Intelligent Transportation System (ITS) solutions. The platform consists of a newly developed GNSS/GPRS On Board Unit (OBU) to be installed in 500 cars, a backend server and a specially...

  5. Polarized beams in high energy storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Montague, B W [European Organization for Nuclear Research, Geneva (Switzerland)

    1984-11-01

    In recent years there has been a considerable advance in understanding the spin motion of particles in storage rings and accelerators. The survey presented here outlines the early historical development in this field, describes the basic ideas governing the kinetics of polarized particles in electromagnetic fields and shows how these have evolved into the current description of polarized beam behaviour. Orbital motion of particles influences their spin precession, and depolarization of a beam can result from excitation of spin resonances by orbit errors and oscillations. Electrons and positrons are additionally influenced by the quantized character of synchrotron radiation, which not only provides a polarizing mechanism but also enhances depolarizing effects. Progress in the theoretical formulation of these phenomena has clarified the details of the physical processes and suggested improved methods of compensating spin resonances. Full use of polarized beams for high-energy physics with storage rings requires spin rotators to produce longitudinal polarization in the interaction regions. Variants of these schemes, dubbed Siberian snakes, provide a curious precession topology which can substantially reduce depolarization in the high-energy range. Efficient polarimetry is an essential requirement for implementing polarized beams, whose utility for physics can be enhanced by various methods of spin manipulation.

  6. Accelerating polarized beams in Tevatron

    International Nuclear Information System (INIS)

    Teng, L.C.

    1989-02-01

    In this paper, we will examine the totality of equipment, manpower and cost necessary to obtain a polarized proton beam in the Tevatron. We will not, however, be concerned with the acquisition and acceleration of polarized /bar p/ beams. Furthermore we will consider only a planar main ring without overpass, although it is expected that Siberian snake schemes could be made to apply equally well to non-planar machines. In addition to not wanting to tackle here the task of reformulating the theory for a non-planar closed orbit, we also anticipate that as part of the Tevatron upgrade the main ring will in the not too distant future, be replaced by a planar main injector situated in a separate tunnel. 4 refs., 11 figs., 1 tab

  7. Continuous Platform Development

    DEFF Research Database (Denmark)

    Nielsen, Ole Fiil

    low risks and investments but also with relatively fuzzy results. When looking for new platform projects, it is important to make sure that the company and market is ready for the introduction of platforms, and to make sure that people from marketing and sales, product development, and downstream......, but continuous product family evolution challenges this strategy. The concept of continuous platform development is based on the fact that platform development should not be a one-time experience but rather an ongoing process of developing new platforms and updating existing ones, so that product family...

  8. Congenital orbital teratoma

    OpenAIRE

    Aiyub, Shereen; Chan, Weng Onn; Szetu, John; Sullivan, Laurence J; Pater, John; Cooper, Peter; Selva, Dinesh

    2013-01-01

    We present a case of mature congenital orbital teratoma managed with lid-sparing exenteration and dermis fat graft. This is a case report on the management of congenital orbital teratoma. A full-term baby was born in Fiji with prolapsed right globe which was surrounded by a nonpulsatile, cystic mass. Clinical and imaging features were consistent with congenital orbital teratoma. Due to limited surgical expertise, the patient was transferred to Adelaide, Australia for further management. The p...

  9. Pictorial essay: Orbital tuberculosis

    International Nuclear Information System (INIS)

    Narula, Mahender K; Chaudhary, Vikas; Baruah, Dhiraj; Kathuria, Manoj; Anand, Rama

    2010-01-01

    Tuberculosis of the orbit is rare, even in places where tuberculosis is endemic. The disease may involve soft tissue, the lacrimal gland, or the periosteum or bones of the orbital wall. Intracranial extension, in the form of extradural abscess, and infratemporal fossa extension has been described. This pictorial essay illustrates the imaging findings of nine histopathologically confirmed cases of orbital tuberculosis. All these patients responded to antituberculous treatment

  10. Radiology of orbital trauma

    International Nuclear Information System (INIS)

    Kelly, J.K.; Lazo, A.; Metes, J.J.

    1988-01-01

    Computed tomography has become the gold standard against which to measure orbital imaging modalities. The simultaneous display of bone, soft tissues, paranasal sinuses, and intracranial structures is a unique advantage. Radiation dose and cost have been cited as disadvantages. These would suggest that CT be reserved for the patient with significant orbital injury or difficult diagnostic problems. Magnetic resonance is limited in the investigation of orbital trauma

  11. Neonatal orbital abscess

    Directory of Open Access Journals (Sweden)

    Khalil M Al-Salem

    2014-01-01

    Full Text Available Orbital complications due to ethmoiditis are rare in neonates. A case of orbital abscess due to acute ethmoiditis in a 28-day-old girl is presented. A Successful outcome was achieved following antimicrobial therapy alone; spontaneous drainage of the abscess occurred from the lower lid without the need for surgery. From this case report, we intend to emphasize on eyelid retraction as a sign of neonatal orbital abscess, and to review all the available literature of similar cases.

  12. The orbital record in stratigraphy

    Science.gov (United States)

    Fischer, Alfred G.

    1992-01-01

    Orbital signals are being discovered in pre-Pleistocene sediments. Due to their hierarchical nature these cycle patterns are complex, and the imprecision of geochronology generally makes the assignment of stratigraphic cycles to specific orbital cycles uncertain, but in sequences such as the limnic Newark Group under study by Olsen and pelagic Cretaceous sequence worked on by our Italo-American group the relative frequencies yield a definitive match to the Milankovitch hierarchy. Due to the multiple ways in which climate impinges on depositional systems, the orbital signals are recorded in a multiplicity of parameters, and affect different sedimentary facies in different ways. In platform carbonates, for example, the chief effect is via sea-level variations (possibly tied to fluctuating ice volume), resulting in cycles of emergence and submergence. In limnic systems it finds its most dramatic expression in alternations of lake and playa conditions. Biogenic pelagic oozes such as chalks and the limestones derived from them display variations in the carbonate supplied by planktonic organisms such as coccolithophores and foraminifera, and also record variations in the aeration of bottom waters. Whereas early studies of stratigraphic cyclicity relied mainly on bedding variations visible in the field, present studies are supplementing these with instrumental scans of geochemical, paleontological, and geophysical parameters which yield quantitative curves amenable to time-series analysis; such analysis is, however, limited by problems of distorted time-scales. My own work has been largely concentrated on pelagic systems. In these, the sensitivity of pelagic organisms to climatic-oceanic changes, combined with the sensitivity of botton life to changes in oxygen availability (commonly much more restricted in the Past than now) has left cyclic patterns related to orbital forcing. These systems are further attractive because (1) they tend to offer depositional continuity

  13. The effects of Dresselhaus and Rashba spin-orbit interactions on the electron tunneling in a non-magnetic heterostructure

    International Nuclear Information System (INIS)

    Lu Jianduo; Li Jianwen

    2010-01-01

    We theoretically investigate the electron transport properties in a non-magnetic heterostructure with both Dresselhaus and Rashba spin-orbit interactions. The detailed-numerical results show that (1) the large spin polarization can be achieved due to Dresselhaus and Rashba spin-orbit couplings induced splitting of the resonant level, although the magnetic field is zero in such a structure, (2) the Rashba spin-orbit coupling plays a greater role on the spin polarization than the Dresselhaus spin-orbit interaction does, and (3) the transmission probability and the spin polarization both periodically change with the increase of the well width.

  14. Orbital glass in HTSC

    International Nuclear Information System (INIS)

    Kusmartsev, F.V.

    1992-10-01

    The physical reasons why the orbital glass may exist in granular high-temperature superconductors and the existing experimental data appeared recently are discussed. The orbital glass is characterized by the coexistence of the orbital paramagnetic state with the superconducting state and occurs at small magnetic fields H c0 c1 . The transition in orbital glass arises at the critical field H c0 which is inversely proportional to the surface cross-area S of an average grain. In connection with theoretical predictions the possible experiments are proposed. (author). 10 refs

  15. Isospin dependence of the spin-orbit splitting in nuclei

    International Nuclear Information System (INIS)

    Isakov, V.I.

    2007-01-01

    The analysis has been made of experimental data on level spectra, single-nucleon transfer reactions near closed shells, and data on polarization effects in charge-exchange (p, n) reactions between isoanalogous states of nuclei with even A. It is concluded that there is a significant difference between the spin-orbit splittings of neutrons and protons in identical orbitals. This conclusion is confirmed in the frame work of different theoretical approaches [ru

  16. Cross-Platform Technologies

    Directory of Open Access Journals (Sweden)

    Maria Cristina ENACHE

    2017-04-01

    Full Text Available Cross-platform - a concept becoming increasingly used in recent years especially in the development of mobile apps, but this consistently over time and in the development of conventional desktop applications. The notion of cross-platform software (multi-platform or platform-independent refers to a software application that can run on more than one operating system or computing architecture. Thus, a cross-platform application can operate independent of software or hardware platform on which it is execute. As a generic definition presents a wide range of meanings for purposes of this paper we individualize this definition as follows: we will reduce the horizon of meaning and we use functionally following definition: a cross-platform application is a software application that can run on more than one operating system (desktop or mobile identical or in a similar way.

  17. Globally Polarized Quark-gluon Plasma in Non-central A+ACollisions

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Zuo-tang; Wang, Xin-Nian

    2004-10-01

    Produced partons have large local relative orbital angular momentum along the direction opposite to the reaction plane in the early stage of non-central heavy-ion collisions. Parton scattering is shown to polarize quarks along the same direction due to spin-orbital coupling.Such global quark polarization will lead to many observable consequences,such as left-right asymmetry of hadron spectra, global transverse polarization of thermal photons, dileptons and hadrons. Hadrons from the decay of polarized resonances will have azimuthal asymmetry similar to the elliptic flow. Global hyperon polarization is predicted with indifferent hadronization scenarios and can be easily tested.

  18. Polarization measurement and vertical aperture optimization for obtaining circularly polarized bend-magnet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kortright, J.B.; Rice, M.; Hussain, Z. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    Growing interest in utilizing circular polarization prompted the design of bend-magnet beamline 9.3.2 at the Advanced Light Source, covering the 30-1500 eV spectral region, to include vertical aperturing capabilities for optimizing the collection of circular polarization above and below the orbit plane. After commissioning and early use of the beamline, a multilayer polarimeter was used to characterize the polarization state of the beam as a function of vertical aperture position. This report partially summarizes the polarimetry measurements and compares results with theoretical calculations intended to simulate experimental conditions.

  19. Tunnelling of orbital angular momentum in parallel optical waveguides

    International Nuclear Information System (INIS)

    Alexeyev, C N; Fadeyeva, T A; Yavorsky, M A; Boklag, N A

    2011-01-01

    We study the evolution of circularly polarized optical vortices (OVs) in the system of two coupled few-mode optical fibres. We demonstrate that upon propagation OVs tunnel into the adjacent fibre as a complex superposition of OVs that comprise also OVs of opposite polarization and topological charge. The initial OV may tunnel into the other fibre as the same vortex state of lesser energy. The evolution of the orbital angular momentum in coupled fibres is studied

  20. A numerical model of the electrodynamics of plasma within the contaminant gas cloud of the space shuttle orbiter at low Earth orbit

    International Nuclear Information System (INIS)

    Eccles, J.V.; Raitt, W.J.; Banks, P.M.

    1989-01-01

    This paper presents results from a two-dimensional, finite-difference model used to solve for the time evolution of low beta plasma within the neutral contaminant cloud in the vicinity of space platforms in low earth orbit. The model of the ambient and contaminant plasma dynamics takes into account the effects of the geomagnetic field, electric fields, background ionosphere, ion-neutral collisions, chemistry, and both Pederson and Hall currents. Net ionization and charge exchange source terms are included in the fluid equations to study electrodynamic effects of chemistry within a moving neutral cloud in the low earth orbit ionosphere. The model is then used with complete water cloud chemistry to simulate the known outgassing situation of the space shuttle Orbiter. A comparison is made of the model results with plasma observations made during daytime on OSS-1/STS-3 mission. The reported density enhancements of the OSS-1 mission are unattainable with normal photoionization and charge exchange rates of simple water cloud chemistry used in the two-dimensional model. The enhanced densities are only attained by a generic chemistry model if a net ionization rate 1,000 times higher than the photoionization rate of water is used. It is also shown that significant plasma buildup at the front of the contaminant neutral cloud can occur due to momentum transfer from the neutral outgas cloud to the plasma through elastic collisions and charge exchange. The currents caused by elastic and reactive collisions result in the generation of a small polarization electric field within the outgas cloud

  1. Nuclear polarization and neutrons

    International Nuclear Information System (INIS)

    Glaettli, H.

    1985-01-01

    Different possibilities for the use of polarized nuclei in thermal neutron scattering on condensed matter are reviewed. Highly polarized nuclei are the starting point for studying dipolar magnetic order. Systematic measurement of spin-dependent scattering lengths is possible on samples with polarized nuclei. Highly polarized hydrogen should help to unravel complicated structures in chemistry and biology. The use of polarized proton targets as an energy-independent neutron polarizer in the thermal and epithermal region should be considered afresh. (author)

  2. Congenital orbital encephalocele, orbital dystopia, and exophthalmos.

    Science.gov (United States)

    Hwang, Kun; Kim, Han Joon

    2012-07-01

    We present here an exceedingly rare variant of a nonmidline basal encephalocele of the spheno-orbital type, and this was accompanied with orbital dystopia in a 56-year-old man. On examination, his left eye was located more inferolaterally than his right eye, and the patient said this had been this way since his birth. The protrusion of his left eye was aggravated when he is tired. His naked visual acuity was 0.7/0.3, and the ocular pressure was 14/12 mm Hg. The exophthalmometry was 10/14 to 16 mm. His eyeball motion was not restricted, yet diplopia was present in all directions. The distance from the midline to the medial canthus was 20/15 mm. The distance from the midline to the midpupillary line was 35/22 mm. The vertical dimension of the palpebral fissure was 12/9 mm. The height difference of the upper eyelid margin was 11 mm, and the height difference of the lower eyelid margin was 8 mm. Facial computed tomography and magnetic resonance imaging showed left sphenoid wing hypoplasia and herniation of the left anterior temporal pole and dura mater into the orbit, and this resulted into left exophthalmos and encephalomalacia in the left anterior temporal pole. To the best of our knowledge, our case is the second case of basal encephalocele and orbital dystopia.

  3. Titan Orbiter Aerorover Mission

    Science.gov (United States)

    Sittler Jr., E. C.; Acuna, M.; Burchell, M. J.; Coates, A.; Farrell, W.; Flasar, M.; Goldstein, B. E.; Gorevan, S.; Hartle, R. E.; Johnson, W. T. K.

    2001-01-01

    We propose a combined Titan orbiter and Titan Aerorover mission with an emphasis on both in situ and remote sensing measurements of Titan's surface, atmosphere, ionosphere, and magnetospheric interaction. The biological aspect of the Titan environment will be emphasized by the mission (i.e., search for organic materials which may include simple organics to 'amono' analogues of amino acids and possibly more complex, lightening detection and infrared, ultraviolet, and charged particle interactions with Titan's surface and atmosphere). An international mission is assumed to control costs. NASA will provide the orbiter, launch vehicle, DSN coverage and operations, while international partners will provide the Aerorover and up to 30% of the cost for the scientific instruments through collaborative efforts. To further reduce costs we propose a single PI for orbiter science instruments and a single PI for Aerorover science instruments. This approach will provide single command/data and power interface between spacecraft and orbiter instruments that will have redundant central DPU and power converter for their instruments. A similar approach could be used for the Aerorover. The mission profile will be constructed to minimize conflicts between Aerorover science, orbiter radar science, orbiter radio science, orbiter imaging science, and orbiter fields and particles (FP) science. Additional information is contained in the original extended abstract.

  4. Orbital and adnexal sarcoidosis

    NARCIS (Netherlands)

    Prabhakaran, Venkatesh C.; Saeed, Perooz; Esmaeli, Bita; Sullivan, Timothy J.; Mcnab, Alan; Davis, Garry; Valenzuela, Alejandra; Leibovitch, Igal; Kesler, Anat; Sivak-Callcott, Jennifer; Hoyama, Erika; Selva, Dinesh

    2007-01-01

    To present the clinical features and management in a series of patients with orbital and adnexal sarcoidosis. This multicenter retrospective study included patients with biopsy-proven noncaseating granuloma involving the orbit or adnexa and evidence of systemic sarcoidosis. Clinical records were

  5. Update on orbital reconstruction.

    Science.gov (United States)

    Chen, Chien-Tzung; Chen, Yu-Ray

    2010-08-01

    Orbital trauma is common and frequently complicated by ocular injuries. The recent literature on orbital fracture is analyzed with emphasis on epidemiological data assessment, surgical timing, method of approach and reconstruction materials. Computed tomographic (CT) scan has become a routine evaluation tool for orbital trauma, and mobile CT can be applied intraoperatively if necessary. Concomitant serious ocular injury should be carefully evaluated preoperatively. Patients presenting with nonresolving oculocardiac reflex, 'white-eyed' blowout fracture, or diplopia with a positive forced duction test and CT evidence of orbital tissue entrapment require early surgical repair. Otherwise, enophthalmos can be corrected by late surgery with a similar outcome to early surgery. The use of an endoscope-assisted approach for orbital reconstruction continues to grow, offering an alternative method. Advances in alloplastic materials have improved surgical outcome and shortened operating time. In this review of modern orbital reconstruction, several controversial issues such as surgical indication, surgical timing, method of approach and choice of reconstruction material are discussed. Preoperative fine-cut CT image and thorough ophthalmologic examination are key elements to determine surgical indications. The choice of surgical approach and reconstruction materials much depends on the surgeon's experience and the reconstruction area. Prefabricated alloplastic implants together with image software and stereolithographic models are significant advances that help to more accurately reconstruct the traumatized orbit. The recent evolution of orbit reconstruction improves functional and aesthetic results and minimizes surgical complications.

  6. Orbital wall fractures

    International Nuclear Information System (INIS)

    Iinuma, Toshitaka; Ishio, Ken-ichirou; Yoshinami, Hiroyoshi; Kuriyama, Jun-ichi; Hirota, Yoshiharu.

    1993-01-01

    A total of 59 cases of mild facial fractures (simple orbital wall fractures, 34 cases, other facial fractures, 25 cases) with the clinical suspects of orbital wall fractures were evaluated both by conventional views (Waters' and Caldwell views) and coronal CT scans. Conventional views were obtained, as an average, after 4 days and CT after 7 days of injuries. Both the medial wall and the floor were evaluated at two sites, i.e., anterior and posterior. The ethmoid-maxillary plate was also included in the study. The degree of fractures was classified as, no fractures, fractures of discontinuity, dislocation and fragmentation. The coronal CT images in bone window condition was used as reference and the findings were compared between conventional views and CT. The correct diagnosis was obtained as follows: orbital floor (anterior, 78%, posterior, 73%), medial orbital wall (anterior, 72%, posterior, 72%) and ethmoid-maxillary plate (64%). The false positive diagnosis was as follows: orbital floor (anterior only, 13%), medial orbital wall (anterior only, 7%) and ethmoid-maxillary plate (11%). The false negative diagnosis was as follows: orbital floor (anterior, 9%, posterior, 10%), medial orbital wall (anterior, 21%, posterior, 28%) and ethmoid-maxillary plate (21%). The results were compared with those of others in the past. (author)

  7. Neutron polarization in polarized 3He targets

    International Nuclear Information System (INIS)

    Friar, J.L.; Gibson, B.F.; Payne, G.L.; Bernstein, A.M.; Chupp, T.E.

    1990-01-01

    Simple formulas for the neutron and proton polarizations in polarized 3 He targets are derived assuming (1) quasielastic final states; (2) no final-state interactions; (3) no meson-exchange currents; (4) large momentum transfers; (5) factorizability of 3 He SU(4) response-function components. Numerical results from a wide variety of bound-state solutions of the Faddeev equations are presented. It is found that this simple model predicts the polarization of neutrons in a fully polarized 3 He target to be 87%, while protons should have a slight residual polarization of -2.7%. Numerical studies show that this model works very well for quasielastic electron scattering

  8. Weights assessment for orbit-on-demand vehicles

    Science.gov (United States)

    Macconochie, I. O.; Martin, J. A.; Breiner, C. A.; Cerro, J. A.

    1985-01-01

    Future manned, reusable earth-to-orbit vehicles may be required to reach orbit within hours or even minutes of a mission decision. A study has been conducted to consider vehicles with such a capability. In the initial phase of the study, 11 vehicles were sized for deployment of 5000 lbs to a polar orbit. From this matrix, two of the most promising concepts were resized for a modified mission and payload. A key feature of the study was the use of consistent mass estimating techniques for a broad range of concepts, allowing direct comparisons of sizes and weights.

  9. Strong electron correlation in photoionization of spin-orbit doublets

    International Nuclear Information System (INIS)

    Amusia, M.Ya.; Chernysheva, L.V.; Manson, S.T.; Msezane, A.M.; Radojevic, V.

    2002-01-01

    A new and explicitly many-body aspect of the 'leveraging' of the spin-orbit interaction is demonstrated, spin-orbit activated interchannel coupling, which can significantly alter the photoionization cross section of a spin-orbit doublet. As an example, it is demonstrated via a modified version of the spin-polarized random phase approximation with exchange, that a recently observed unexplained structure in the Xe 3d 5/2 photoionization cross section [A. Kivimaeki et al., Phys. Rev. A 63, 012716 (2000)] is entirely due to this effect. Similar features are predicted for Cs 3d 5/2 and Ba 3d 5/2

  10. ADMS Evaluation Platform

    Energy Technology Data Exchange (ETDEWEB)

    2018-01-23

    Deploying an ADMS or looking to optimize its value? NREL offers a low-cost, low-risk evaluation platform for assessing ADMS performance. The National Renewable Energy Laboratory (NREL) has developed a vendor-neutral advanced distribution management system (ADMS) evaluation platform and is expanding its capabilities. The platform uses actual grid-scale hardware, large-scale distribution system models, and advanced visualization to simulate realworld conditions for the most accurate ADMS evaluation and experimentation.

  11. Platform development supportedby gaming

    DEFF Research Database (Denmark)

    Mikkola, Juliana Hsuan; Hansen, Poul H. Kyvsgård

    2007-01-01

    The challenge of implementing industrial platforms in practice can be described as a configuration problem caused by high number of variables, which often have contradictory influences on the total performance of the firm. Consequently, the specific platform decisions become extremely complex......, possibly increasing the strategic risks for the firm. This paper reports preliminary findings on platform management process at LEGO, a Danish toy company.  Specifically, we report the process of applying games combined with simulations and workshops in the platform development. We also propose a framework...

  12. Omnidirectional holonomic platforms

    International Nuclear Information System (INIS)

    Pin, F.G.; Killough, S.M.

    1994-01-01

    This paper presents the concepts for a new family of wheeled platforms which feature full omnidirectionality with simultaneous and independently controlled rotational and translational motion capabilities. The authors first present the orthogonal-wheels concept and the two major wheel assemblies on which these platforms are based. They then describe how a combination of these assemblies with appropriate control can be used to generate an omnidirectional capability for mobile robot platforms. The design and control of two prototype platforms are then presented and their respective characteristics with respect to rotational and translational motion control are discussed

  13. Platform decommissioning costs

    International Nuclear Information System (INIS)

    Rodger, David

    1998-01-01

    There are over 6500 platforms worldwide contributing to the offshore oil and gas production industry. In the North Sea there are around 500 platforms in place. There are many factors to be considered in planning for platform decommissioning and the evaluation of options for removal and disposal. The environmental impact, technical feasibility, safety and cost factors all have to be considered. This presentation considers what information is available about the overall decommissioning costs for the North Sea and the costs of different removal and disposal options for individual platforms. 2 figs., 1 tab

  14. Polarization of photoelectrons produced from atoms by synchrotron radiation

    International Nuclear Information System (INIS)

    Hughes, V.W.; Lu, D.C.; Huang, K.N.

    1981-01-01

    The polarization of photoelectrons from stoms has proved to be an important tool for studying correlation effects in atoms, as well as relativistic effects such as the spin-orbit interaction. Extensive experimental and theoretical studies have been made of the Fano effect, which is the production of polarized electrons by photoionization of unpolarized atoms by circularly polarized light. The experiments have dealt mostly with alkali atoms and with photon energies slightly above the ionization thresholds. Measurements that could be made to utilize polarized radiation are discussed

  15. Polarized proton beam for eRHIC

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Roser, T. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    RHIC has provided polarized proton collisions from 31 GeV to 255 GeV in the past decade. To preserve polarization through numerous depolarizing resonances through the whole accelerator chain, harmonic orbit correction, partial snakes, horizontal tune jump system and full snakes have been used. In addition, close attentions have been paid to betatron tune control, orbit control and beam line alignment. The polarization of 60% at 255 GeV has been delivered to experiments with 1.8×1011 bunch intensity. For the eRHIC era, the beam brightness has to be maintained to reach the desired luminosity. Since we only have one hadron ring in the eRHIC era, existing spin rotator and snakes can be converted to six snake configuration for one hadron ring. With properly arranged six snakes, the polarization can be maintained at 70% at 250 GeV. This paper summarizes the effort and plan to reach high polarization with small emittance for eRHIC.

  16. Topology of tokamak orbits

    International Nuclear Information System (INIS)

    Rome, J.A.; Peng, Y.K.M.

    1978-09-01

    Guiding center orbits in noncircular axisymmetric tokamak plasmas are studied in the constants of motion (COM) space of (v, zeta, psi/sub m/). Here, v is the particle speed, zeta is the pitch angle with respect to the parallel equilibrium current, J/sub parallels/, and psi/sub m/ is the maximum value of the poloidal flux function (increasing from the magnetic axis) along the guiding center orbit. Two D-shaped equilibria in a flux-conserving tokamak having β's of 1.3% and 7.7% are used as examples. In this space, each confined orbit corresponds to one and only one point and different types of orbits (e.g., circulating, trapped, stagnation and pinch orbits) are represented by separate regions or surfaces in the space. It is also shown that the existence of an absolute minimum B in the higher β (7.7%) equilibrium results in a dramatically different orbit topology from that of the lower β case. The differences indicate the confinement of additional high energy (v → c, within the guiding center approximation) trapped, co- and countercirculating particles whose orbit psi/sub m/ falls within the absolute B well

  17. Harmonically excited orbital variations

    International Nuclear Information System (INIS)

    Morgan, T.

    1985-01-01

    Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs

  18. Spin Orbit Torque in Ferromagnetic Semiconductors

    KAUST Repository

    Li, Hang

    2016-06-21

    Electrons not only have charges but also have spin. By utilizing the electron spin, the energy consumption of electronic devices can be reduced, their size can be scaled down and the efficiency of `read\\' and `write\\' in memory devices can be significantly improved. Hence, the manipulation of electron spin in electronic devices becomes more and more appealing for the advancement of microelectronics. In spin-based devices, the manipulation of ferromagnetic order parameter using electrical currents is a very useful means for current-driven operation. Nowadays, most of magnetic memory devices are based on the so-called spin transfer torque, which stems from the spin angular momentum transfer between a spin-polarized current and the magnetic order parameter. Recently, a novel spin torque effect, exploiting spin-orbit coupling in non-centrosymmetric magnets, has attracted a massive amount of attention. This thesis addresses the nature of spin-orbit coupled transport and torques in non-centrosymmetric magnetic semiconductors. We start with the theoretical study of spin orbit torque in three dimensional ferromagnetic GaMnAs. Using the Kubo formula, we calculate both the current-driven field-like torque and anti-damping-like torque. We compare the numerical results with the analytical expressions in the model case of a magnetic Rashba two-dimensional electron gas. Parametric dependencies of the different torque components and similarities to the analytical results of the Rashba two-dimensional electron gas in the weak disorder limit are described. Subsequently we study spin-orbit torques in two dimensional hexagonal crystals such as graphene, silicene, germanene and stanene. In the presence of staggered potential and exchange field, the valley degeneracy can be lifted and we obtain a valley-dependent Berry curvature, leading to a tunable antidamping torque by controlling the valley degree of freedom. This thesis then addresses the influence of the quantum spin Hall

  19. Orbital angular momentum of general astigmatic modes

    International Nuclear Information System (INIS)

    Visser, Jorrit; Nienhuis, Gerard

    2004-01-01

    We present an operator method to obtain complete sets of astigmatic Gaussian solutions of the paraxial wave equation. In case of general astigmatism, the astigmatic intensity and phase distribution of the fundamental mode differ in orientation. As a consequence, the fundamental mode has a nonzero orbital angular momentum, which is not due to phase singularities. Analogous to the operator method for the quantum harmonic oscillator, the corresponding astigmatic higher-order modes are obtained by repeated application of raising operators on the fundamental mode. The nature of the higher-order modes is characterized by a point on a sphere, in analogy with the representation of polarization on the Poincare sphere. The north and south poles represent astigmatic Laguerre-Gaussian modes, similar to circular polarization on the Poincare sphere, while astigmatic Hermite-Gaussian modes are associated with points on the equator, analogous to linear polarization. We discuss the propagation properties of the modes and their orbital angular momentum, which depends on the degree of astigmatism and on the location of the point on the sphere

  20. Bell’s measure and implementing quantum Fourier transform with orbital angular momentum of classical light

    Science.gov (United States)

    Song, Xinbing; Sun, Yifan; Li, Pengyun; Qin, Hongwei; Zhang, Xiangdong

    2015-01-01

    We perform Bell’s measurement for the non-separable correlation between polarization and orbital angular momentum from the same classical vortex beam. The violation of Bell’s inequality for such a non-separable classical correlation has been demonstrated experimentally. Based on the classical vortex beam and non-quantum entanglement between the polarization and the orbital angular momentum, the Hadamard gates and conditional phase gates have been designed. Furthermore, a quantum Fourier transform has been implemented experimentally. PMID:26369424

  1. Quark Orbital Angular Momentum

    Directory of Open Access Journals (Sweden)

    Burkardt Matthias

    2015-01-01

    Full Text Available Definitions of orbital angular momentum based on Wigner distributions are used as a framework to discuss the connection between the Ji definition of the quark orbital angular momentum and that of Jaffe and Manohar. We find that the difference between these two definitions can be interpreted as the change in the quark orbital angular momentum as it leaves the target in a DIS experiment. The mechanism responsible for that change is similar to the mechanism that causes transverse single-spin asymmetries in semi-inclusive deep-inelastic scattering.

  2. Thrombosis of orbital varices

    International Nuclear Information System (INIS)

    Boschi Oyhenart, J.; Tenyi, A.; Boschi Pau, J.

    2002-01-01

    Orbital varices are venous malformations produced by an abnormal dilatation of one or more orbital veins, probably associated with congenital weakness of the vascular wall. They are rare lesions, usually occurring in young patients, that produce intermittent proptosis related to the increase in the systemic venous pressure. The presence of hemorrhage or thrombosis is associated with rapid development of proptosis, pain and decreased ocular motility. We report the cases of two adult patients with orbital varices complicated by thrombosis in whom the diagnosis was based on computed tomography. The ultrasound and magnetic resonance findings are also discussed. (Author) 16 refs

  3. Design and construction of the POLAR detector

    Science.gov (United States)

    Produit, N.; Bao, T. W.; Batsch, T.; Bernasconi, T.; Britvich, I.; Cadoux, F.; Cernuda, I.; Chai, J. Y.; Dong, Y. W.; Gauvin, N.; Hajdas, W.; Kole, M.; Kong, M. N.; Kramert, R.; Li, L.; Liu, J. T.; Liu, X.; Marcinkowski, R.; Orsi, S.; Pohl, M.; Rapin, D.; Rybka, D.; Rutczynska, A.; Shi, H. L.; Socha, P.; Sun, J. C.; Song, L. M.; Szabelski, J.; Traseira, I.; Xiao, H. L.; Wang, R. J.; Wen, X.; Wu, B. B.; Zhang, L.; Zhang, L. Y.; Zhang, S. N.; Zhang, Y. J.; Zwolinska, A.

    2018-01-01

    The POLAR detector is a space based Gamma Ray Burst (GRB) polarimeter with a wide field of view, which covers almost half the sky. The instrument uses Compton scattering of gamma rays on a plastic scintillator hodoscope to measure the polarization of the incoming photons. The instrument has been successfully launched on board of the Chinese space laboratory Tiangong 2 on September 15, 2016. The construction of the instrument components is described in this article. Details are provided on problems encountered during the construction phase and their solutions. Initial performance of the instrument in orbit is as expected from ground tests and Monte Carlo simulation.

  4. Classifying spaces of degenerating polarized Hodge structures

    CERN Document Server

    Kato, Kazuya

    2009-01-01

    In 1970, Phillip Griffiths envisioned that points at infinity could be added to the classifying space D of polarized Hodge structures. In this book, Kazuya Kato and Sampei Usui realize this dream by creating a logarithmic Hodge theory. They use the logarithmic structures begun by Fontaine-Illusie to revive nilpotent orbits as a logarithmic Hodge structure. The book focuses on two principal topics. First, Kato and Usui construct the fine moduli space of polarized logarithmic Hodge structures with additional structures. Even for a Hermitian symmetric domain D, the present theory is a refinem

  5. Polarized electron sources

    International Nuclear Information System (INIS)

    Prepost, R.

    1994-01-01

    The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented

  6. Polarized electron sources

    Energy Technology Data Exchange (ETDEWEB)

    Prepost, R. [Univ. of Wisconsin, Madison, WI (United States)

    1994-12-01

    The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented.

  7. The Carter constant for inclined orbits about a massive Kerr black hole: I. Circular orbits

    Energy Technology Data Exchange (ETDEWEB)

    Komorowski, P G; Valluri, S R; Houde, M, E-mail: pkomorow@uwo.c, E-mail: valluri@uwo.c, E-mail: mhoude2@uwo.c [Department of Physics and Astronomy, University of Western Ontario, London, Ontario (Canada)

    2010-11-21

    In an extreme binary black hole system, an orbit will increase its angle of inclination ({iota}) as it evolves in Kerr spacetime. We focus our attention on the behaviour of the Carter constant (Q) for near-polar orbits, and develop an analysis that is independent of and complements radiation-reaction models. For a Schwarzschild black hole, the polar orbits represent the abutment between the prograde and retrograde orbits at which Q is at its maximum value for given values of the latus rectum ({tilde l}) and the eccentricity (e). The introduction of spin ({tilde S}={vert_bar}J{vert_bar}/M{sup 2}) to the massive black hole causes this boundary, or abutment, to be moved towards greater orbital inclination; thus, it no longer cleanly separates prograde and retrograde orbits. To characterize the abutment of a Kerr black hole (KBH), we first investigated the last stable orbit (LSO) of a test-particle about a KBH, and then extended this work to general orbits. To develop a better understanding of the evolution of Q we developed analytical formulae for Q in terms of {tilde l}, e and {tilde S} to describe elliptical orbits at the abutment, polar orbits and LSOs. By knowing the analytical form of {partial_derivative}Q/{partial_derivative}{tilde l} at the abutment, we were able to test a 2PN flux equation for Q. We also used these formulae to numerically calculate the {partial_derivative}{iota}/{partial_derivative}{tilde l} of hypothetical circular orbits that evolve along the abutment. From these values we have determined that {partial_derivative}{iota}/{partial_derivative}{tilde l} = -(122.7{tilde S} - 36{tilde S}{sup 3}){tilde l}{sup -11/2} - (63/2 {tilde S} + 35/4 {tilde S}{sup 3}){tilde l}{sup -9/2} - 15/2 {tilde S}{tilde l}{sup -7/2} - 9/2 {tilde S}{tilde l}{sup -5/2}. By taking the limit of this equation for {tilde l} {yields} {infinity}, and comparing it with the published result for the weak-field radiation reaction, we found the upper limit on

  8. Polarized neutron spectrometer

    International Nuclear Information System (INIS)

    Abov, Yu.G.; Novitskij, V.V.; Alfimenkov, V.P.; Galinskij, E.M.; Mareev, Yu.D.; Pikel'ner, L.B.; Chernikov, A.N.; Lason', L.; Tsulaya, V.M.; Tsulaya, M.I.

    2000-01-01

    The polarized neutron spectrometer, intended for studying the interaction of polarized neutrons with nuclei and condensed media in the area of energies from thermal up to several electron-volt, is developed at the IBR-2 reactor (JINR, Dubna). Diffraction on the Co(92%)-Fe(8%) magnetized monocrystals is used for the neutron polarization and polarization analysis. The neutron polarization within the whole energy range equals ∼ 95% [ru

  9. Groundwater Assessment Platform

    OpenAIRE

    Podgorski, Joel; Berg, Michael

    2018-01-01

    The Groundwater Assessment Platform is a free, interactive online GIS platform for the mapping, sharing and statistical modeling of groundwater quality data. The modeling allows users to take advantage of publicly available global datasets of various environmental parameters to produce prediction maps of their contaminant of interest.

  10. EURESCOM Services Platform

    NARCIS (Netherlands)

    Nieuwenhuis, Lambertus Johannes Maria; van Halteren, Aart

    1999-01-01

    This paper presents the results of the EURESCOM Project 715. In February 1999, a large team of researchers from six European public network operators completed a two year period of cooperative experiments on a TINA-based environment, called the EURESCOM Services Platform (ESP). This platform

  11. ExoMars Trace Gas Orbiter provides atmospheric data during Aerobraking into its final orbit

    Science.gov (United States)

    Svedhem, Hakan; Vago, Jorge L.; Bruinsma, Sean; Müller-Wodarg, Ingo; ExoMars 2016 Team

    2017-10-01

    After the arrival of the Trace Gas Orbiter (TGO) at Mars on 19 October 2016 a number of initial orbit change manoeuvres were executed and the spacecraft was put in an orbit with a 24 hour period and 74 degrees inclination. The spacecraft and its four instruments were thoroughly checked out after arrival and a few measurements and images were taken in November 2016 and in Feb-March 2017. The solar occultation observations have however not yet been possible due to lack of the proper geometry.On 15 March a long period of aerobraking to reach the final 400km semi-circular frozen orbit (370x430km, with a fixed pericentre latitude). This orbit is optimised for the payload observations and for the communication relay with the ExoMars Rover, due to arrive in 2021.The aerobraking is proceeding well and the final orbit is expected to be reached in April 2018. A large data set is being acquired for the upper atmosphere of Mars, from the limit of the sensitivity of the accelerometer, down to lowest altitude of the aerobraking at about 105km. Initial analysis has shown a highly variable atmosphere with a slightly lower density then predicted by existing models. Until the time of the abstract writing no dust storms have been observed.The ExoMars programme is a joint activity by the European Space Agency(ESA) and ROSCOSMOS, Russia. ESA is providing the TGO spacecraft and Schiaparelli (EDM) and two of the TGO instruments and ROSCOSMOS is providing the Proton launcher and the other two TGO instruments. After the arrival of the ExoMars 2020 mission, consisting of a Rover and a Surface platform also launched by a Proton rocket, the TGO will handle the communication between the Earth and the Rover and Surface Platform through its (NASA provided) UHF communication system.

  12. A Wide Field Auroral Imager (WFAI for low Earth orbit missions

    Directory of Open Access Journals (Sweden)

    N. P. Bannister

    2007-03-01

    Full Text Available A comprehensive understanding of the solar wind interaction with Earth's coupled magnetosphere-ionosphere system requires an ability to observe the charged particle environment and auroral activity from the same platform, generating particle and photon image data which are matched in time and location. While unambiguous identification of the particles giving rise to the aurora requires a Low Earth Orbit satellite, obtaining adequate spatial coverage of aurorae with the relatively limited field of view of current space bourne auroral imaging systems requires much higher orbits. A goal for future satellite missions, therefore, is the development of compact, wide field-of-view optics permitting high spatial and temporal resolution ultraviolet imaging of the aurora from small spacecraft in low polar orbit. Microchannel plate optics offer a method of achieving the required performance. We describe a new, compact instrument design which can observe a wide field-of-view with the required spatial resolution. We report the focusing of 121.6 nm radiation using a spherically-slumped, square-pore microchannel plate with a focal length of 32 mm and an F number of 0.7. Measurements are compared with detailed ray-trace simulations of imaging performance. The angular resolution is 2.7±0.2° for the prototype, corresponding to a footprint ~33 km in diameter for an aurora altitude of 110 km and a spacecraft altitude of 800 km. In preliminary analysis, a more recent optic has demonstrated a full width at half maximum of 5.0±0.3 arcminutes, corresponding to a footprint of ~1 km from the same spacecraft altitude. We further report the imaging properties of a convex microchannel plate detector with planar resistive anode readout; this detector, whose active surface has a radius of curvature of only 100 mm, is shown to meet the spatial resolution and sensitivity requirements of the new wide field auroral imager (WFAI.

  13. Congenital orbital teratoma.

    Science.gov (United States)

    Aiyub, Shereen; Chan, Wengonn; Szetu, John; Sullivan, Laurence J; Pater, John; Cooper, Peter; Selva, Dinesh

    2013-12-01

    We present a case of mature congenital orbital teratoma managed with lid-sparing exenteration and dermis fat graft. This is a case report on the management of congenital orbital teratoma. A full-term baby was born in Fiji with prolapsed right globe which was surrounded by a nonpulsatile, cystic mass. Clinical and imaging features were consistent with congenital orbital teratoma. Due to limited surgical expertise, the patient was transferred to Adelaide, Australia for further management. The patient underwent a lid-sparing exenteration with frozen section control of the apical margin. A dermis fat graft from the groin was placed beneath the lid skin to provide volume. Histopathology revealed mature tissues from each of the three germ cell layers which confirmed the diagnosis of mature teratoma. We describe the successful use of demis fat graft in socket reconstruction following lid-sparing exenteration for congenital orbital teratoma.

  14. Congenital orbital teratoma

    Directory of Open Access Journals (Sweden)

    Shereen Aiyub

    2013-01-01

    Full Text Available We present a case of mature congenital orbital teratoma managed with lid-sparing exenteration and dermis fat graft. This is a case report on the management of congenital orbital teratoma. A full-term baby was born in Fiji with prolapsed right globe which was surrounded by a nonpulsatile, cystic mass. Clinical and imaging features were consistent with congenital orbital teratoma. Due to limited surgical expertise, the patient was transferred to Adelaide, Australia for further management. The patient underwent a lid-sparing exenteration with frozen section control of the apical margin. A dermis fat graft from the groin was placed beneath the lid skin to provide volume. Histopathology revealed mature tissues from each of the three germ cell layers which confirmed the diagnosis of mature teratoma. We describe the successful use of demis fat graft in socket reconstruction following lid-sparing exenteration for congenital orbital teratoma.

  15. PS Booster Orbit Correction

    CERN Document Server

    Chanel, M; Rumolo, G; Tomás, R; CERN. Geneva. AB Department

    2008-01-01

    At the end of the 2007 run, orbit measurements were carried out in the 4 rings of the PS Booster (PSB) for different working points and beam energies. The aim of these measurements was to provide the necessary input data for a PSB realignment campaign during the 2007/2008 shutdown. Currently, only very few corrector magnets can be operated reliably in the PSB; therefore the orbit correction has to be achieved by displacing (horizontally and vertically) and/or tilting some of the defocusing quadrupoles (QDs). In this report we first describe the orbit measurements, followed by a detailed explanation of the orbit correction strategy. Results and conclusions are presented in the last section.

  16. Product Platform Modeling

    DEFF Research Database (Denmark)

    Pedersen, Rasmus

    for customisation of products. In many companies these changes in the business environment have created a controversy between the need for a wide variety of products offered to the marketplace and a desire to reduce variation within the company in order to increase efficiency. Many companies use the concept...... other. These groups can be varied and combined to form different product variants without increasing the internal variety in the company. Based on the Theory of Domains, the concept of encapsulation in the organ domain is introduced, and organs are formulated as platform elements. Included......This PhD thesis has the title Product Platform Modelling. The thesis is about product platforms and visual product platform modelling. Product platforms have gained an increasing attention in industry and academia in the past decade. The reasons are many, yet the increasing globalisation...

  17. Product Platform Replacements

    DEFF Research Database (Denmark)

    Sköld, Martin; Karlsson, Christer

    2012-01-01

    . To shed light on this unexplored and growing managerial concern, the purpose of this explorative study is to identify operational challenges to management when product platforms are replaced. Design/methodology/approach – The study uses a longitudinal field-study approach. Two companies, Gamma and Omega...... replacement was chosen in each company. Findings – The study shows that platform replacements primarily challenge managers' existing knowledge about platform architectures. A distinction can be made between “width” and “height” in platform replacements, and it is crucial that managers observe this in order...... to challenge their existing knowledge about platform architectures. Issues on technologies, architectures, components and processes as well as on segments, applications and functions are identified. Practical implications – Practical implications are summarized and discussed in relation to a framework...

  18. Ross Sea oceanographic data, 1983-1987 : USCGC Glacier, January-February 1983; USCGC Polar Sea, January-February 1984; USCGC Polar Star, February 1985; USCGC Polar Sea, February 1987 (NODC Accession 8900108)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and chemical data were collected using CTD casts from USCGC POLAR SEA and other platforms in the Ross Sea from 19 December 1976 to 06 February...

  19. Antisymmetric Orbit Functions

    Directory of Open Access Journals (Sweden)

    Anatoliy Klimyk

    2007-02-01

    Full Text Available In the paper, properties of antisymmetric orbit functions are reviewed and further developed. Antisymmetric orbit functions on the Euclidean space $E_n$ are antisymmetrized exponential functions. Antisymmetrization is fulfilled by a Weyl group, corresponding to a Coxeter-Dynkin diagram. Properties of such functions are described. These functions are closely related to irreducible characters of a compact semisimple Lie group $G$ of rank $n$. Up to a sign, values of antisymmetric orbit functions are repeated on copies of the fundamental domain $F$ of the affine Weyl group (determined by the initial Weyl group in the entire Euclidean space $E_n$. Antisymmetric orbit functions are solutions of the corresponding Laplace equation in $E_n$, vanishing on the boundary of the fundamental domain $F$. Antisymmetric orbit functions determine a so-called antisymmetrized Fourier transform which is closely related to expansions of central functions in characters of irreducible representations of the group $G$. They also determine a transform on a finite set of points of $F$ (the discrete antisymmetric orbit function transform. Symmetric and antisymmetric multivariate exponential, sine and cosine discrete transforms are given.

  20. Local orbit feedback

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Critically aligned experiments are sensitive to small changes in the electron beam orbit. At the NSLS storage rings, the electron beam and photon beam motions have been monitored over the past several years. In the survey conducted in 1986 by the NSLS Users Executive Committee, experimenters requested the vertical beam position variation and the vertical angle variation, within a given fill, remain within 10 μm and 10 μr, respectively. This requires improvement in the beam stability by about one order of magnitude. At the NSLS and SSRL storage rings, the beam that is originally centered on the position monitor by a dc orbit correction is observed to have two kinds of motion: a dc drift over a storage period of several hours and a beam bounce about its nominal position. These motions are a result of the equilibrium orbit not being held perfectly stable due to time-varying errors introduced into the magnetic guide field by power supplies, mechanical vibration of the magnets, cooling water temperature variations, etc. The approach to orbit stabilization includes (1) identifying and suppressing as many noise sources on the machine as possible, (2) correcting the beam position globally (see Section 6) by controlling a number of correctors around the circumference of the machine, and (3) correcting the beam position and angle at a given source location by position feedback using local detectors and local orbit bumps. The third approach, called Local Orbit Feedback will be discussed in this section

  1. Star of AOXiang: An innovative 12U CubeSat to demonstrate polarized light navigation and microgravity measurement

    Science.gov (United States)

    Yu, Xiaozhou; Zhou, Jun; Zhu, Peijie; Guo, Jian

    2018-06-01

    Most of the CubeSats have a volume range from 1U to 3U, which limits their applications due to the difficulty of miniaturizing payloads. To facilitate the needs on a larger but low-cost satellite platform, the AOXiang (AOX) project has been developed by Northwestern Polytechnical University (NPU). The primary objectives of AOX project are four-folds: 1) To demonstrate the world first 12U CubeSat Star of AOXiang and 12U orbit deployer which uses an innovative electromagnetic unlocking technology. 2) To investigate the feasibility of using polarized sunlight for spacecraft attitude determination and navigation, and perform microgravity research using a miniaturized gravimeter. 3) To test a fault tolerant on-board computer using the System On the Programmable Chip (SOPC) technology, and 4) To gain the experience from developing the CubeSat and the subsystems. The CubeSat was launched in June 2016. Now, the mission has achieved all the goals. This paper provides the detail information of the AOX project, with a focus on the introduction of the subsystems of the 12U CubeSat, the orbit deployer and the payloads. The recent in-orbit results of the first NPU are also presented. In addition to the educational objective that has been reached with more than 50 young scholars and students participated in the project.

  2. The nuclear spin-orbit coupling

    International Nuclear Information System (INIS)

    Bell, J.S.; Skyrme, T.H.R.

    1994-01-01

    Analysis of the nucleon-nucleon scattering around 100 MeV has determined the spin-orbit coupling part of the two-body scattering matrix at that energy, and a reasonable extrapolation to lower energies is possible. This scattering amplitude has been used, in the spirit of Brueckner's nuclear model, to estimate the resultant single-body spin-orbit coupling for a single nucleon interacting with a large nucleus. This resultant potential has a radial dependence approximately proportional to r -1 d ρ /dr, and with a magnitude in good agreement with that required to explain the doublet splittings in nuclei and the polarization of nucleons scattered elastically off nuclei. (author). 14 refs, 2 figs

  3. Mesoscopic rings with spin-orbit interactions

    Energy Technology Data Exchange (ETDEWEB)

    Berche, Bertrand; Chatelain, Christophe; Medina, Ernesto, E-mail: berche@lpm.u-nancy.f [Statistical Physics Group, Institut Jean Lamour, UMR CNRS No 7198, Universite Henri Poincare, Nancy 1, B.P. 70239, F-54506 Vandoeuvre les Nancy (France)

    2010-09-15

    A didactic description of charge and spin equilibrium currents on mesoscopic rings in the presence of spin-orbit interaction is presented. Emphasis is made on the non-trivial construction of the correct Hamiltonian in polar coordinates, the calculation of eigenvalues and eigenfunctions and the symmetries of the ground-state properties. Spin currents are derived following an intuitive definition, and then a more thorough derivation is built upon the canonical Lagrangian formulation that emphasizes the SU(2) gauge structure of the transport problem of spin-1/2 fermions in spin-orbit active media. The quantization conditions that follow from the constraint of single-valued Pauli spinors are also discussed. The targeted students are those of a graduate condensed matter physics course.

  4. Plasma balance equations based on orbit theory

    International Nuclear Information System (INIS)

    Lehnert, B.

    1982-01-01

    A set of plasma balance equations is proposed which is based on orbit theory and the particle distribution function, to provide means for theoretical analysis of a number of finite Larmor radius (FLR) phenomena without use of the Vlasov equation. Several important FLR effects originate from the inhomogeneity of an electric field in the plasma. The exact solution of a simple case shows that this inhomogeneity introduces fundamental changes in the physics of the particle motion. Thus, the periodic Larmor motion (gyration) is shifted in frequency and becomes elliptically polarized. Further, the non-periodic guiding-centre drift obtains additional components, part of which are accelerated such as to make the drift orbits intersect the equipotential surfaces of a static electric field. An attempt is finally made to classify the FLR effects, also with the purpose of identifying phenomena which have so far not been investigated. (author)

  5. Verifying black hole orbits with gravitational spectroscopy

    International Nuclear Information System (INIS)

    Drasco, Steve

    2009-01-01

    Gravitational waves from test masses bound to geodesic orbits of rotating black holes are simulated, using Teukolsky's black hole perturbation formalism, for about ten thousand generic orbital configurations. Each binary radiates power exclusively in modes with frequencies that are integer-linear combinations of the orbit's three fundamental frequencies. General spectral properties are found with a survey of orbits about a black hole taken to be rotating at 80% of the maximal spin. The orbital eccentricity is varied from 0.1 to 0.9. Inclination ranges from 20 deg. to 160 deg. and comes to within 20 deg. of polar. Semilatus rectum is varied from 1.2 to 3 times the value at the innermost stable circular orbits. The following general spectral properties are found: (i) 99% of the radiated power is typically carried by a few hundred modes, and at most by about a thousand modes, (ii) the dominant frequencies can be grouped into a small number of families defined by fixing two of the three integer frequency multipliers, and (iii) the specifics of these trends can be qualitatively inferred from the geometry of the orbit under consideration. Detections using triperiodic analytic templates modeled on these general properties would constitute a verification of radiation from an adiabatic sequence of black hole orbits and would recover the evolution of the fundamental orbital frequencies. In an analogy with ordinary spectroscopy, this would compare to observing the Bohr model's atomic hydrogen spectrum without being able to rule out alternative atomic theories or nuclei. The suitability of such a detection technique is demonstrated using snapshots computed at 12-hour intervals throughout the last three years before merger of a kludged inspiral. The system chosen is typical of those thought to occur in galactic nuclei and to be observable with space-based gravitational wave detectors like LISA. Because of circularization, the number of excited modes decreases as the binary

  6. QED effects on individual atomic orbital energies

    Science.gov (United States)

    Kozioł, Karol; Aucar, Gustavo A.

    2018-04-01

    Several issues, concerning QED corrections, that are important in precise atomic calculations are presented. The leading QED corrections, self-energy and vacuum polarization, to the orbital energy for selected atoms with 30 ≤ Z ≤ 118 have been calculated. The sum of QED and Breit contributions to the orbital energy is analyzed. It has been found that for ns subshells the Breit and QED contributions are of comparative size, but for np and nd subshells the Breit contribution takes a major part of the QED+Breit sum. It has also, been found that the Breit to leading QED contributions ratio for ns subshells is almost independent of Z. The Z-dependence of QED and Breit+QED contributions per subshell is shown. The fitting coefficients may be used to estimate QED effects on inner molecular orbitals. We present results of our calculations for QED contributions to orbital energy of valence ns-subshell for group 1 and 11 atoms and discuss about the reliability of these numbers by comparing them with experimental first ionization potential data.

  7. Polarized targets and beams

    International Nuclear Information System (INIS)

    Meyer, W.

    1985-01-01

    First the experimental situation of the single-pion photoproduction and the photodisintegration of the deuteron is briefly discussed. Then a description of the Bonn polarization facilities is given. The point of main effort is put on the polarized target which plays a vital role in the program. A facility for photon induced double polarization experiments at ELSA will be presented in section 4. Properties of a tensor polarized deuteron target are discussed in section 5. The development in the field of polarized targets, especially on new target materials, enables a new generation of polarized target experiments with (polarized) electrons. Some comments on the use of a polarized target in combination with electron beams will be discussed in section 6. Electron deuteron scattering from a tensor polarized deuteron target is considered and compared with other experimental possibilities. (orig./HSI)

  8. GPS Low Cross-polarization Antenna Array for Orbit Determination beyond Geostationary Earth Orbits

    Data.gov (United States)

    National Aeronautics and Space Administration — This work will expand on the recent successes of Navigator on MMS, opening new and unforeseen possibilities for the use of GPS for very high-altitude applications up...

  9. The vacuum platform

    Science.gov (United States)

    McNab, A.

    2017-10-01

    This paper describes GridPP’s Vacuum Platform for managing virtual machines (VMs), which has been used to run production workloads for WLCG and other HEP experiments. The platform provides a uniform interface between VMs and the sites they run at, whether the site is organised as an Infrastructure-as-a-Service cloud system such as OpenStack, or an Infrastructure-as-a-Client system such as Vac. The paper describes our experience in using this platform, in developing and operating VM lifecycle managers Vac and Vcycle, and in interacting with VMs provided by LHCb, ATLAS, ALICE, CMS, and the GridPP DIRAC service to run production workloads.

  10. Polarization transfer from polarized nuclear spin to μ- spin in muonic atom

    International Nuclear Information System (INIS)

    Kuno, Yoshitaka; Nagamine, Kanetada; Yamazaki, Toshimitsu.

    1987-02-01

    A theoretical study of polarization transfer from an initially-polarized nuclear spin to a μ - spin in a muonic atom is given. The switching of the hyperfine interaction at excited muonic states as well as at the ground 1s state is taken into account. The upper state of hyperfine doublet at the muonic 1s state is considered to proceed down to the lower state. It is found that as the hyperfine interaction becomes effective at higher excited muonic orbitals, a less extent of polarization is transferred from the nuclear spin to the μ - spin. The theoretical values obtained are compared with the recent experiment of μ - repolarization in a polarized 209 Bi target. (author)

  11. Optimizing Orbit-Instrument Configuration for Global Precipitation Mission (GPM) Satellite Fleet

    Science.gov (United States)

    Smith, Eric A.; Adams, James; Baptista, Pedro; Haddad, Ziad; Iguchi, Toshio; Im, Eastwood; Kummerow, Christian; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Following the scientific success of the Tropical Rainfall Measuring Mission (TRMM) spearheaded by a group of NASA and NASDA scientists, their external scientific collaborators, and additional investigators within the European Union's TRMM Research Program (EUROTRMM), there has been substantial progress towards the development of a new internationally organized, global scale, and satellite-based precipitation measuring mission. The highlights of this newly developing mission are a greatly expanded scope of measuring capability and a more diversified set of science objectives. The mission is called the Global Precipitation Mission (GPM). Notionally, GPM will be a constellation-type mission involving a fleet of nine satellites. In this fleet, one member is referred to as the "core" spacecraft flown in an approximately 70 degree inclined non-sun-synchronous orbit, somewhat similar to TRMM in that it carries both a multi-channel polarized passive microwave radiometer (PMW) and a radar system, but in this case it will be a dual frequency Ku-Ka band radar system enabling explicit measurements of microphysical DSD properties. The remainder of fleet members are eight orbit-synchronized, sun-synchronous "constellation" spacecraft each carrying some type of multi-channel PMW radiometer, enabling no worse than 3-hour diurnal sampling over the entire globe. In this configuration the "core" spacecraft serves as a high quality reference platform for training and calibrating the PMW rain retrieval algorithms used with the "constellation" radiometers. Within NASA, GPM has advanced to the pre-formulation phase which has enabled the initiation of a set of science and technology studies which will help lead to the final mission design some time in the 2003 period. This presentation first provides an overview of the notional GPM program and mission design, including its organizational and programmatic concepts, scientific agenda, expected instrument package, and basic flight

  12. Elliptical quantum dots as on-demand single photons sources with deterministic polarization states

    Energy Technology Data Exchange (ETDEWEB)

    Teng, Chu-Hsiang; Demory, Brandon; Ku, Pei-Cheng, E-mail: peicheng@umich.edu [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48105 (United States); Zhang, Lei; Hill, Tyler A.; Deng, Hui [Department of Mechanical Engineering, University of Michigan, 2350 Hayward St., Ann Arbor, Michigan 48105 (United States)

    2015-11-09

    In quantum information, control of the single photon's polarization is essential. Here, we demonstrate single photon generation in a pre-programmed and deterministic polarization state, on a chip-scale platform, utilizing site-controlled elliptical quantum dots (QDs) synthesized by a top-down approach. The polarization from the QD emission is found to be linear with a high degree of linear polarization and parallel to the long axis of the ellipse. Single photon emission with orthogonal polarizations is achieved, and the dependence of the degree of linear polarization on the QD geometry is analyzed.

  13. E-Orbit Functions

    Directory of Open Access Journals (Sweden)

    Jiri Patera

    2008-01-01

    Full Text Available We review and further develop the theory of $E$-orbit functions. They are functions on the Euclidean space $E_n$ obtained from the multivariate exponential function by symmetrization by means of an even part $W_{e}$ of a Weyl group $W$, corresponding to a Coxeter-Dynkin diagram. Properties of such functions are described. They are closely related to symmetric and antisymmetric orbit functions which are received from exponential functions by symmetrization and antisymmetrization procedure by means of a Weyl group $W$. The $E$-orbit functions, determined by integral parameters, are invariant withrespect to even part $W^{aff}_{e}$ of the affine Weyl group corresponding to $W$. The $E$-orbit functions determine a symmetrized Fourier transform, where these functions serve as a kernel of the transform. They also determine a transform on a finite set of points of the fundamental domain $F^{e}$ of the group $W^{aff}_{e}$ (the discrete $E$-orbit function transform.

  14. Influence of the Choice of Lunar Gravity Model on Orbit Determination for Lunar Orbiters

    Directory of Open Access Journals (Sweden)

    Young-Rok Kim

    2018-01-01

    Full Text Available We examine the influence of the lunar gravity model on the orbit determination (OD of a lunar orbiter operating in a 100 km high, lunar polar orbit. Doppler and sequential range measurements by three Deep Space Network antennas and one Korea Deep Space Antenna were used. For measurement simulation and OD analysis, STK11 and ODTK6 were utilized. GLGM2, LP100K, LP150Q, GRAIL420A, and GRAIL660B were used for investigation of lunar gravity model selection effect. OD results were assessed by position and velocity uncertainties with error covariance and an external orbit comparison using simulated true orbit. The effect of the lunar gravity models on the long-term OD, degree and order level, measurement-acquisition condition, and lunar altitude was investigated. For efficiency verification, computational times for the five lunar gravity models were compared. Results showed that significant improvements to OD accuracy are observed by applying a GRAIL-based model; however, applying a full order and degree gravity modeling is not always the best strategy, owing to the computational burden. Consequently, we consider that OD using GRAIL660B with 70 × 70 degree and order is the most efficient strategy for mission preanalysis. This study provides useful guideline for KPLO OD analysis during nominal mission operation.

  15. Terahertz radiation by subpicosecond spin-polarized photocurrent originating from Dirac electrons in a Rashba-type polar semiconductor

    Science.gov (United States)

    Kinoshita, Yuto; Kida, Noriaki; Miyamoto, Tatsuya; Kanou, Manabu; Sasagawa, Takao; Okamoto, Hiroshi

    2018-04-01

    The spin-splitting energy bands induced by the relativistic spin-orbit interaction in solids provide a new opportunity to manipulate the spin-polarized electrons on the subpicosecond timescale. Here, we report one such example in a bulk Rashba-type polar semiconductor BiTeBr. Strong terahertz electromagnetic waves are emitted after the resonant excitation of the interband transition between the Rashba-type spin-splitting energy bands with a femtosecond laser pulse circularly polarized. The phase of the emitted terahertz waves is reversed by switching the circular polarization. This suggests that the observed terahertz radiation originates from the subpicosecond spin-polarized photocurrents, which are generated by the asymmetric depopulation of the Dirac state. Our result provides a way for the current-induced terahertz radiation and its phase control by the circular polarization of incident light without external electric fields.

  16. The universal modular platform

    International Nuclear Information System (INIS)

    North, R.B.

    1995-01-01

    A new and patented design for offshore wellhead platforms has been developed to meet a 'fast track' requirement for increased offshore production, from field locations not yet identified. The new design uses modular construction to allow for radical changes in the water depth of the final location and assembly line efficiency in fabrication. By utilizing high strength steels and structural support from the well conductors the new design accommodates all planned production requirements on a support structure significantly lighter and less expensive than the conventional design it replaces. Twenty two platforms based on the new design were ready for installation within 18 months of the project start. Installation of the new platforms began in 1992 for drilling support and 1993 for production support. The new design has become the Company standard for all future production platforms. Large saving and construction costs have been realized through its light weight, flexibility in both positioning and water depth, and its modular construction

  17. Identification of platform levels

    DEFF Research Database (Denmark)

    Mortensen, Niels Henrik

    2005-01-01

    reduction, ability to launch a wider product portfolio without increasing resources and reduction of complexity within the whole company. To support the multiple product development process, platform based product development has in many companies such as Philips, VW, Ford etc. proven to be a very effective...... product development in one step and therefore the objective of this paper is to identify levels of platform based product development. The structure of this paper is as follows. First the applied terminology for platforms will be briefly explained and then characteristics between single and multi product...... development will be examined. Based on the identification of the above characteristics five platform levels are described. The research presented in this paper is a result of MSc, Ph.D projects at the Technical University of Denmark and consultancy projects within the organisation of Institute of Product...

  18. Paper based electronics platform

    KAUST Repository

    Nassar, Joanna Mohammad; Sevilla, Galo Andres Torres; Hussain, Muhammad Mustafa

    2017-01-01

    A flexible and non-functionalized low cost paper-based electronic system platform fabricated from common paper, such as paper based sensors, and methods of producing paper based sensors, and methods of sensing using the paper based sensors

  19. USA Hire Testing Platform

    Data.gov (United States)

    Office of Personnel Management — The USA Hire Testing Platform delivers tests used in hiring for positions in the Federal Government. To safeguard the integrity of the hiring processes and ensure...

  20. Climatic changes on orbital and sub-orbital time scale recorded by the Guliya ice core in Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    姚檀栋; 徐柏青; 蒲健辰

    2001-01-01

    Based on ice core records in the Tibetan Plateau and Greenland, the features and possible causes of climatic changes on orbital and sub-orbital time scale were discussed. Orbital time scale climatic change recorded in ice core from the Tibetan Plateau is typically ahead of that from polar regions, which indicates that climatic change in the Tibetan Plateau might be earlier than polar regions. The solar radiation change is a major factor that dominates the climatic change on orbital time scale. However, climatic events on sub-orbital time scale occurred later in the Tibetan Plateau than in the Arctic Region, indicating a different mechanism. For example, the Younger Dryas and Heinrich events took place earlier in Greenland ice core record than in Guliya ice core record. It is reasonable to propose the hypothesis that these climatic events were affected possibly by the Laurentide Ice Sheet. Therefore, ice sheet is critically important to climatic change on sub-orbital time scale in some ice ages.

  1. [Secondary orbital lymphoma].

    Science.gov (United States)

    Basanta, I; Sevillano, C; Álvarez, M D

    2015-09-01

    A case is presented of an 85 year-old Caucasian female with lymphoma that recurred in the orbit (secondary ocular adnexal lymphoma). The orbital tumour was a diffuse large B-cell lymphoma according to the REAL classification (Revised European-American Lymphoma Classification). Orbital lymphomas are predominantly B-cell proliferations of a variety of histological types, and most are low-grade tumours. Patients are usually middle-aged or elderly, and it is slightly more common in women. A palpable mass, proptosis and blepharoptosis are the most common signs of presentation. Copyright © 2011 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  2. Large orbit neoclassical transport

    International Nuclear Information System (INIS)

    Lin, Z.; Tang, W.M.; Lee, W.W.

    1997-01-01

    Neoclassical transport in the presence of large ion orbits is investigated. The study is motivated by the recent experimental results that ion thermal transport levels in enhanced confinement tokamak plasmas fall below the open-quotes irreducible minimum levelclose quotes predicted by standard neoclassical theory. This apparent contradiction is resolved in the present analysis by relaxing the basic neoclassical assumption that the ions orbital excursions are much smaller than the local toroidal minor radius and the equilibrium scale lengths of the system. Analytical and simulation results are in agreement with trends from experiments. The development of a general formalism for neoclassical transport theory with finite orbit width is also discussed. copyright 1997 American Institute of Physics

  3. Scattering with polarized neutrons

    International Nuclear Information System (INIS)

    Schweizer, J.

    2007-01-01

    In the history of neutron scattering, it was shown very soon that the use of polarized neutron beams brings much more information than usual scattering with unpolarized neutrons. We shall develop here the different scattering methods that imply polarized neutrons: 1) polarized beams without polarization analysis, the flipping ratio method; 2) polarized beams with a uniaxial polarization analysis; 3) polarized beams with a spherical polarization analysis. For all these scattering methods, we shall give examples of the physical problems which can been solved by these methods, particularly in the field of magnetism: investigation of complex magnetic structures, investigation of spin or magnetization densities in metals, insulators and molecular compounds, separation of magnetic and nuclear scattering, investigation of magnetic properties of liquids and amorphous materials and even, for non magnetic material, separation between coherent and incoherent scattering. (author)

  4. Polarized Light Corridor Demonstrations.

    Science.gov (United States)

    Davies, G. R.

    1990-01-01

    Eleven demonstrations of light polarization are presented. Each includes a brief description of the apparatus and the effect demonstrated. Illustrated are strain patterns, reflection, scattering, the Faraday Effect, interference, double refraction, the polarizing microscope, and optical activity. (CW)

  5. National Community Solar Platform

    Energy Technology Data Exchange (ETDEWEB)

    Rupert, Bart [Clean Energy Collective, Louisville, CO (United States)

    2016-06-30

    This project was created to provide a National Community Solar Platform (NCSP) portal known as Community Solar Hub, that is available to any entity or individual who wants to develop community solar. This has been done by providing a comprehensive portal to make CEC’s solutions, and other proven community solar solutions, externally available for everyone to access – making the process easy through proven platforms to protect subscribers, developers and utilities. The successful completion of this project provides these tools via a web platform and integration APIs, a wide spectrum of community solar projects included in the platform, multiple groups of customers (utilities, EPCs, and advocates) using the platform to develop community solar, and open access to anyone interested in community solar. CEC’s Incubator project includes web-based informational resources, integrated systems for project information and billing systems, and engagement with customers and users by community solar experts. The combined effort externalizes much of Clean Energy Collective’s industry-leading expertise, allowing third parties to develop community solar without duplicating expensive start-up efforts. The availability of this platform creates community solar projects that are cheaper to build and cheaper to participate in, furthering the goals of DOE’s SunShot Initiative. Final SF 425 Final SF 428 Final DOE F 2050.11 Final Report Narrative

  6. Techniques in polarization physics

    International Nuclear Information System (INIS)

    Clausnitzer, G.

    1974-01-01

    A review of the current status of the technical tools necessary to perform different kinds of polarization experiments is presented, and the absolute and relative accuracy with which data can be obtained is discussed. A description of polarized targets and sources of polarized fast neutrons is included. Applications of polarization techniques to other fields is mentioned briefly. (14 figures, 3 tables, 110 references) (U.S.)

  7. Orbital welding technique

    International Nuclear Information System (INIS)

    Hoeschen, W.

    2003-01-01

    The TIG (Tungsten-inert gas) orbital welding technique is applied in all areas of pipe welding. The process is mainly used for austenitic and ferritic materials but also for materials like aluminium, nickel, and titanium alloys are commonly welded according to this technique. Thin-walled as well as thick-walled pipes are welded economically. The application of orbital welding is of particular interest in the area of maintenance of thick-walled pipes that is described in this article. (orig.) [de

  8. Mean Orbital Elements for Geosynchronous Orbit - II - Orbital inclination, longitude of ascending node, mean longitude

    Directory of Open Access Journals (Sweden)

    Kyu-Hong Choi

    1990-06-01

    Full Text Available The osculating orbital elements include the mean, secular, long period, and short period terms. The iterative algorithm used for conversion of osculating orbital elements to mean orbital elements is described. The mean orbital elements of Wc, Ws, and L are obtained.

  9. Polarized Moessbauer transitions

    International Nuclear Information System (INIS)

    Barb, D.

    1975-01-01

    Theoretical aspects of the emission, absorption and scattering of polarized gamma rays are reviewed for a general case of combined magnetic and electric hyperfine interactions; various possibilities of obtaining polarized gamma sources are described and examples are given of the applications of Moessbauer spectroscopy with polarized gamma rays in solving problems of solid state physics. (A.K.)

  10. Geographical Income Polarization

    DEFF Research Database (Denmark)

    Azhar, Hussain; Jonassen, Anders Bruun

    inter municipal income inequality. Counter factual simulations show that rising property prices to a large part explain the rise in polarization. One side-effect of polarization is tendencies towards a parallel polarization of residence location patterns, where low skilled individuals tend to live...

  11. Calculation of polarization effects

    International Nuclear Information System (INIS)

    Chao, A.W.

    1983-09-01

    Basically there are two areas of accelerator applications that involve beam polarization. One is the acceleration of a polarized beam (most likely a proton beam) in a synchrotron. Another concerns polarized beams in an electron storage ring. In both areas, numerical techniques have been very useful

  12. Cloud Based Earth Observation Data Exploitation Platforms

    Science.gov (United States)

    Romeo, A.; Pinto, S.; Loekken, S.; Marin, A.

    2017-12-01

    In the last few years data produced daily by several private and public Earth Observation (EO) satellites reached the order of tens of Terabytes, representing for scientists and commercial application developers both a big opportunity for their exploitation and a challenge for their management. New IT technologies, such as Big Data and cloud computing, enable the creation of web-accessible data exploitation platforms, which offer to scientists and application developers the means to access and use EO data in a quick and cost effective way. RHEA Group is particularly active in this sector, supporting the European Space Agency (ESA) in the Exploitation Platforms (EP) initiative, developing technology to build multi cloud platforms for the processing and analysis of Earth Observation data, and collaborating with larger European initiatives such as the European Plate Observing System (EPOS) and the European Open Science Cloud (EOSC). An EP is a virtual workspace, providing a user community with access to (i) large volume of data, (ii) algorithm development and integration environment, (iii) processing software and services (e.g. toolboxes, visualization routines), (iv) computing resources, (v) collaboration tools (e.g. forums, wiki, etc.). When an EP is dedicated to a specific Theme, it becomes a Thematic Exploitation Platform (TEP). Currently, ESA has seven TEPs in a pre-operational phase dedicated to geo-hazards monitoring and prevention, costal zones, forestry areas, hydrology, polar regions, urban areas and food security. On the technology development side, solutions like the multi cloud EO data processing platform provides the technology to integrate ICT resources and EO data from different vendors in a single platform. In particular it offers (i) Multi-cloud data discovery, (ii) Multi-cloud data management and access and (iii) Multi-cloud application deployment. This platform has been demonstrated with the EGI Federated Cloud, Innovation Platform Testbed Poland

  13. Valley polarized quantum Hall effect and topological insulator phase transitions in silicene

    KAUST Repository

    Tahir, M.; Schwingenschlö gl, Udo

    2013-01-01

    encountered for graphene, in particular the zero band gap and weak spin orbit interaction. We demonstrate a valley polarized quantum Hall effect and topological insulator phase transitions. We use the Kubo formalism to discuss the Hall conductivity and address

  14. Stability of orbits around planetary satellites considering a disturbing body in an elliptical orbit: Applications to Europa and Ganymede

    Science.gov (United States)

    Cardoso dos Santos, Josué; Carvalho, Jean Paulo; Vilhena de Moraes, Rodolpho

    Europa and Ganymede are two of the four Jupiter’s moons which compose the Galilean satellite. These ones are planetary satellites of greater interest at the present moment among the scientific community. There are some missions being planned to visit them and and the Jovian system. One of them is the cooperation between NASA and ESA for the Europa Jupiter System Mission (EJSM). In this mission are planned the insertion of the spacecrafts JEO (Jupiter Europa Orbiter) and JGO (Jupiter Ganymede Orbiter) into Europa and Ganymede’s orbit. Thus, there is a great necessity for having a better comprehension of the dynamics of the orbits around this planetary satellite. This comprehension is essential for the success of this type of mission. In this context, this work aims to perform a search for low-altitude orbits around these planetary satellites. An emphasis is given in polar orbits. These orbits can be useful in the planning of aerospace activities to be conducted around this planetary satellite, with respect to the stability of orbits of artificial satellites. The study considers orbits of an artificial satellite around Europa and Ganymede under the influence of the third-body perturbation (the gravitational attraction of Jupiter) and the polygenic perturbations. These last ones occur due to forces such as the non-uniform distribution of mass (J2 and J3) of the main (central) body. A simplified dynamic model for polygenic perturbations is used. A new model for the third-body disturbance is presented considering it in an elliptical orbit. The Lagrange planetary equations, which compose a system of nonlinear differential equations, are used to describe the orbital motion of the artificial satellite around Ganymede. The equations showed here are developed in closed form to avoid expansions in inclination and eccentricity.

  15. The Platformization of the Web: Making Web Data Platform Ready

    NARCIS (Netherlands)

    Helmond, A.

    2015-01-01

    In this article, I inquire into Facebook’s development as a platform by situating it within the transformation of social network sites into social media platforms. I explore this shift with a historical perspective on, what I refer to as, platformization, or the rise of the platform as the dominant

  16. Summary of the results from the lunar orbiter laser altimeter after seven years in lunar orbit

    Science.gov (United States)

    Smith, David E.; Zuber, Maria T.; Neumann, Gregory A.; Mazarico, Erwan; Lemoine, Frank G.; Head, James W., III; Lucey, Paul G.; Aharonson, Oded; Robinson, Mark S.; Sun, Xiaoli; Torrence, Mark H.; Barker, Michael K.; Oberst, Juergen; Duxbury, Thomas C.; Mao, Dandan; Barnouin, Olivier S.; Jha, Kopal; Rowlands, David D.; Goossens, Sander; Baker, David; Bauer, Sven; Gläser, Philipp; Lemelin, Myriam; Rosenburg, Margaret; Sori, Michael M.; Whitten, Jennifer; Mcclanahan, Timothy

    2017-02-01

    In June 2009 the Lunar Reconnaissance Orbiter (LRO) spacecraft was launched to the Moon. The payload consists of 7 science instruments selected to characterize sites for future robotic and human missions. Among them, the Lunar Orbiter Laser Altimeter (LOLA) was designed to obtain altimetry, surface roughness, and reflectance measurements. The primary phase of lunar exploration lasted one year, following a 3-month commissioning phase. On completion of its exploration objectives, the LRO mission transitioned to a science mission. After 7 years in lunar orbit, the LOLA instrument continues to map the lunar surface. The LOLA dataset is one of the foundational datasets acquired by the various LRO instruments. LOLA provided a high-accuracy global geodetic reference frame to which past, present and future lunar observations can be referenced. It also obtained high-resolution and accurate global topography that were used to determine regions in permanent shadow at the lunar poles. LOLA further contributed to the study of polar volatiles through its unique measurement of surface brightness at zero phase, which revealed anomalies in several polar craters that may indicate the presence of water ice. In this paper, we describe the many LOLA accomplishments to date and its contribution to lunar and planetary science.

  17. Summary of the Results from the Lunar Orbiter Laser Altimeter after Seven Years in Lunar Orbit

    Science.gov (United States)

    Smith, David E.; Zuber, Maria T.; Neumann, Gregory A.; Mazarico, Erwan; Lemoine, Frank G.; Head, James W., III; Lucey, Paul G.; Aharonson, Oded; Robinson, Mark S.; Sun, Xiaoli; hide

    2016-01-01

    In June 2009 the Lunar Reconnaissance Orbiter (LRO) spacecraft was launched to the Moon. The payload consists of 7 science instruments selected to characterize sites for future robotic and human missions. Among them, the Lunar Orbiter Laser Altimeter (LOLA) was designed to obtain altimetry, surface roughness, and reflectance measurements. The primary phase of lunar exploration lasted one year, following a 3-month commissioning phase. On completion of its exploration objectives, the LRO mission transitioned to a science mission. After 7 years in lunar orbit, the LOLA instrument continues to map the lunar surface. The LOLA dataset is one of the foundational datasets acquired by the various LRO instruments. LOLA provided a high-accuracy global geodetic reference frame to which past, present and future lunar observations can be referenced. It also obtained high-resolution and accurate global topography that were used to determine regions in permanent shadow at the lunar poles. LOLA further contributed to the study of polar volatiles through its unique measurement of surface brightness at zero phase, which revealed anomalies in several polar craters that may indicate the presence of water ice. In this paper, we describe the many LOLA accomplishments to date and its contribution to lunar and planetary science.

  18. PolarTREC: Successful Methods and Tools for Attaining Broad Educational Impacts with Interdisciplinary Polar Science

    Science.gov (United States)

    Timm, K. M.; Warburton, J.; Owens, R.; Warnick, W. K.

    2008-12-01

    PolarTREC--Teachers and Researchers Exploring and Collaborating, a program of the Arctic Research Consortium of the U.S. (ARCUS), is a National Science Foundation (NSF)-funded International Polar Year (IPY) project in which K-12 educators participate in hands-on field experiences in the polar regions, working closely with IPY scientists as a pathway to improving science education. Developing long-term teacher- researcher collaborations through PolarTREC ensures up-to-date climate change science content will permeate the K-12 education system long after the IPY. By infusing education with the cutting edge science from the polar regions, PolarTREC has already shown an increase in student and public knowledge of and interest in the polar regions and global climate change. Preliminary evaluations have shown that PolarTREC's program activities have many positive impacts on educators and their ability to teach science concepts and improve their teaching methods. Additionally, K-12 students polled in interest surveys showed significant changes regarding the importance of understanding the polar regions as a person in today's world. Researchers have been overwhelmingly satisfied with PolarTREC and cited several specific strengths, including the program's crucial link between the teachers' field research experiences and their classroom and the extensive training provided to teachers prior to their expedition. This presentation will focus on other successful components of the PolarTREC program and how researchers and organizations might use these tools to reach out to the public for long-term impacts. Best practices include strategies for working with educators and the development of an internet-based platform for teachers and researchers to interact with the public, combining several communication tools such as online journals and forums, real-time Internet seminars, lesson plans, activities, audio, and other educational resources that address a broad range of scientific

  19. Bohr orbit theory revisited

    International Nuclear Information System (INIS)

    Harcourt, R.D.

    1987-01-01

    Bohr orbit theory is used to calculate energies for the 1S, 2P, 3D, 4F and 5G states of the helium muonic atom, when the muon is excited. These energies are close to those which have been calculated variationally by Huang (1977, Phys. Rev. A 15 1832-8). (author)

  20. Acceleration of polarized particles

    International Nuclear Information System (INIS)

    Buon, J.

    1992-05-01

    The spin kinetics of polarized beams in circular accelerators is reviewed in the case of spin-1/2 particles (electrons and protons) with emphasis on the depolarization phenomena. The acceleration of polarized proton beams in synchrotrons is described together with the cures applied to reduce depolarization, including the use of 'Siberian Snakes'. The in-situ polarization of electrons in storage rings due to synchrotron radiation is studied as well as depolarization in presence of ring imperfections. The applications of electron polarization to accurately calibrate the rings in energy and to use polarized beams in colliding-beam experiments are reviewed. (author) 76 refs., 19 figs., 1 tab

  1. Meteoroid Orbits from Observations

    Science.gov (United States)

    Campbell-Brown, Margaret

    2018-04-01

    Millions of orbits of meteoroids have been measured over the last few decades, and they comprise the largest sample of orbits of solar system bodies which exists. The orbits of these objects can shed light on the distribution and evolution of comets and asteroids in near-Earth space (e.g. Neslusan et al. 2016). If orbits can be measured at sufficiently high resolution, individual meteoroids can be traced back to their parent bodies and, in principle, even to their ejection time (Rudawska et al. 2012). Orbits can be measured with multi-station optical observations or with radar observations.The most fundamental measured quantities are the speed of the meteor and the two angles of the radiant, or point in the sky from which the meteor appears to come. There are many methods used to determine these from observations, but not all produce the most accurate results (Egal et al. 2017). These three measured quantities, along with the time and location of the observation, are sufficient to obtain an orbit (see, e.g., Clark & Wiegert 2011), but the measurements must be corrected for the deceleration of the meteoroid in the atmosphere before it was detected, the rotation of the Earth, and the gravitational attraction of the Earth (including higher order moments if great precision is necessary).Once meteor orbits have been determined, studies of the age and origin of meteor showers (Bruzzone et al., 2015), the parent bodies of sporadic sources (Pokorny et al. 2014), and the dynamics of the meteoroid complex as a whole can be constrained.Bruzzone, J. S., Brown, P., Weryk, R., Campbell-Brown, M., 2015. MNRAS 446, 1625.Clark, D., Wiegert, P., 2011. M&PS 46, 1217.Egal, A., Gural, P., Vaubaillon, J., Colas, F., Thuillot, W., 2017. Icarus 294, 43.Neslusan, L., Vaubaillon, J., Hajdukova, M., 2016. A&A 589, id.A100.Pokorny, P., Vokrouhlicky, D., Nesvorny, D., Campbell-Brown, M., Brown, P., 2014. ApJ 789, id.25.Rudawska, R., Vaubaillon, J., Atreya, P., 2012. A&A 541, id.A2

  2. The International Space Station: A Unique Platform for Remote Sensing of Natural Disasters

    Science.gov (United States)

    Stefanov, William L.; Evans, Cynthia A.

    2014-01-01

    Assembly of the International Space Station (ISS) was completed in 2012, and the station is now fully operational as a platform for remote sensing instruments tasked with collecting scientific data about the Earth system. Remote sensing systems are mounted inside the ISS, primarily in the U.S. Destiny Module's Window Observational Research Facility (WORF), or are located on the outside of the ISS on any of several attachment points. While NASA and other space agencies have had remote sensing systems orbiting Earth and collecting publicly available data since the early 1970s, these sensors are carried onboard free-flying, unmanned satellites. These satellites are traditionally placed into Sun-synchronous polar orbits that allow imaging of the entire surface of the Earth to be repeated with approximately the same Sun illumination (typically local solar noon) over specific areas, with set revisit times that allow uniform data to be taken over long time periods and enable straightforward analysis of change over time. In contrast, the ISS has an inclined, Sun-asynchronous orbit (the solar illumination for data collections over any location changes as the orbit precesses) that carries it over locations on the Earth between approximately 52degnorth and 52deg south latitudes (figure 1). The ISS is also unique among NASA orbital platforms in that it has a human crew. The presence of a crew provides options not available to robotic sensors and platforms, such as the ability to collect unscheduled data of an unfolding event using handheld digital cameras as part of the Crew Earth Observations (CEO) facility and on-the-fly assessment of environmental conditions, such as cloud cover, to determine whether conditions are favorable for data collection. The crew can also swap out internal sensor systems installed in the WORF as needed. The ISS orbit covers more than 90 percent of the inhabited surface of the Earth, allowing the ISS to pass over the same ground locations at

  3. Transactional Network Platform: Applications

    Energy Technology Data Exchange (ETDEWEB)

    Katipamula, Srinivas; Lutes, Robert G.; Ngo, Hung; Underhill, Ronald M.

    2013-10-31

    In FY13, Pacific Northwest National Laboratory (PNNL) with funding from the Department of Energy’s (DOE’s) Building Technologies Office (BTO) designed, prototyped and tested a transactional network platform to support energy, operational and financial transactions between any networked entities (equipment, organizations, buildings, grid, etc.). Initially, in FY13, the concept demonstrated transactions between packaged rooftop air conditioners and heat pump units (RTUs) and the electric grid using applications or "agents" that reside on the platform, on the equipment, on a local building controller or in the Cloud. The transactional network project is a multi-lab effort with Oakridge National Laboratory (ORNL) and Lawrence Berkeley National Laboratory (LBNL) also contributing to the effort. PNNL coordinated the project and also was responsible for the development of the transactional network (TN) platform and three different applications associated with RTUs. This document describes two applications or "agents" in details, and also summarizes the platform. The TN platform details are described in another companion document.

  4. Space platforms - A cost effective evolution of Spacelab operation

    Science.gov (United States)

    Stofan, A. J.

    1981-01-01

    The capabilities added to the Shuttle/Spacelab configuration by the addition of the Power Extension Package (PEP), the Power System (PS), and the Science and Applications Space Platforms (SASP) are reviewed with an emphasis on SASP. SASP are intended for placement in orbit by the Shuttle to test new instruments and systems, for clustering of instrumentation, and for servicing, refurbishment, repair, or augmentation by the Shuttle. The PEP permits extended stays in orbit (30 days), and the PS is an orbital solar array and energy storage system acting as a free flying spacecraft. The Shuttle can deliver payloads to the PS or attach to it for extension of the Spacelab operations. Applications of SASP for long term space-based biological experiments are outlined, and the fact that SASP do not increase the required Shuttle in-orbit time is stressed.

  5. Possible experiment with two counter-orbiting drag-free satellites to obtain a new test of Einstein's general theory of relativity and improved measurements in geodesy

    International Nuclear Information System (INIS)

    Van Patten, R.A.; Everitt, C.W.F.

    1976-01-01

    In 1918, Lense and Thirring calculated that a moon orbiting a rotating planet would experience a nodal dragging effect due to general relativity. We describe an experiment to measure this effect to 1% with two counter-orbiting drag-free satellites in polar earth orbit. In addition to tracking data from existing ground stations, satellite-to-satellite Doppler ranging data are taken near the poles. New geophysical information is inherent in the polar data

  6. Polarization effects. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Courant, E.

    1981-01-01

    The use of polarized proton beams in ISABELLE is important for several general reasons: (1) With a single longitudinally polarized proton beam, effects involving parity violation can be identified and hence processes involving weak interactions can be separated from those involving strong and electromagnetic interactions. (2) Spin effects are important in the strong interactions and can be useful for testing QCD. The technique for obtaining polarized proton beams in ISABELLE appears promising, particularly in view of the present development of a polarized proton beam for the AGS. Projections for the luminosity in ISABELLE for collisions of polarized protons - one or both beams polarized with longitudinal or transverse polarization - range from 1/100 to 1 times the luminosity for unpolarized protons.

  7. The Physics of Polarization

    Science.gov (United States)

    Landi Degl'Innocenti, Egidio

    2015-10-01

    The introductory lecture that has been delivered at this Symposium is a condensed version of an extended course held by the author at the XII Canary Island Winter School from November 13 to November 21, 2000. The full series of lectures can be found in Landi Degl'Innocenti (2002). The original reference is organized in 20 Sections that are here itemized: 1. Introduction, 2. Description of polarized radiation, 3. Polarization and optical devices: Jones calculus and Muller matrices, 4. The Fresnel equations, 5. Dichroism and anomalous dispersion, 6. Polarization in everyday life, 7. Polarization due to radiating charges, 8. The linear antenna, 9. Thomson scattering, 10. Rayleigh scattering, 11. A digression on Mie scattering, 12. Bremsstrahlung radiation, 13. Cyclotron radiation, 14. Synchrotron radiation, 15. Polarization in spectral lines, 16. Density matrix and atomic polarization, 17. Radiative transfer and statistical equilibrium equations, 18. The amplification condition in polarized radiative transfer, and 19. Coupling radiative transfer and statistical equilibrium equations.

  8. Platform-based production development

    DEFF Research Database (Denmark)

    Bossen, Jacob; Brunoe, Thomas Ditlev; Nielsen, Kjeld

    2015-01-01

    Platforms as a means for applying modular thinking in product development is relatively well studied, but platforms in the production system has until now not been given much attention. With the emerging concept of platform-based co-development the importance of production platforms is though...

  9. Early Assessment of VIIRS On-Orbit Calibration and Support Activities

    Science.gov (United States)

    Xiong, Xiaoxiong; Chiang, Kwofu; McIntire, Jeffrey; Oudrari, Hassan; Wu, Aisheng; Schwaller, Mathew; Butler, James

    2012-01-01

    The Suomi National Polar-orbiting Partnership (S-NPP) satellite, formally the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP), provides a bridge between current and future low-Earth orbiting weather and environmental observation satellite systems. The NASA s NPP VIIRS Characterization Support Team (VCST) is designed to assess the long term geometric and radiometric performance of the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument onboard the S-NPP spacecraft and to support NPP Science Team Principal Investigators (PI) for their independent evaluation of VIIRS Environmental Data Records (EDRs). This paper provides an overview of Suomi NPP VIIRS on-orbit calibration activities and examples of sensor initial on-orbit performance. It focuses on the radiometric calibration support activities and capabilities provided by the NASA VCST.

  10. Reusable platform concepts

    International Nuclear Information System (INIS)

    Gudmestad, O.T.; Sparby, B.K.; Stead, B.L.

    1993-01-01

    There is an increasing need to reduce costs of offshore production facilities in order to make development of offshore fields profitable. For small fields with short production time there is in particular a need to investigate ways to reduce costs. The idea of platform reuse is for such fields particularly attractive. This paper will review reusable platform concepts and will discuss their range of application. Particular emphasis will be placed on technical limitations. Traditional concepts as jackups and floating production facilities will be discussed by major attention will be given to newly developed ideas for reuse of steel jackets and concrete structures. It will be shown how the operator for several fields can obtain considerable savings by applying such reusable platform concepts

  11. Lunar Topography: Results from the Lunar Orbiter Laser Altimeter

    Science.gov (United States)

    Neumann, Gregory; Smith, David E.; Zuber, Maria T.; Mazarico, Erwan

    2012-01-01

    The Lunar Orbiter Laser Altimeter (LOLA) onboard the Lunar Reconnaissance Orbiter (LRO) has been operating nearly continuously since July 2009, accumulating over 6 billion measurements from more than 2 billion in-orbit laser shots. LRO's near-polar orbit results in very high data density in the immediate vicinity of the lunar poles, with full coverage at the equator from more than 12000 orbital tracks averaging less than 1 km in spacing at the equator. LRO has obtained a global geodetic model of the lunar topography with 50-meter horizontal and 1-m radial accuracy in a lunar center-of-mass coordinate system, with profiles of topography at 20-m horizontal resolution, and 0.1-m vertical precision. LOLA also provides measurements of reflectivity and surface roughness down to its 5-m laser spot size. With these data LOLA has measured the shape of all lunar craters 20 km and larger. In the proposed extended mission commencing late in 2012, LOLA will concentrate observations in the Southern Hemisphere, improving the density of the polar coverage to nearly 10-m pixel resolution and accuracy to better than 20 m total position error. Uses for these data include mission planning and targeting, illumination studies, geodetic control of images, as well as lunar geology and geophysics. Further improvements in geodetic accuracy are anticipated from the use of re ned gravity fields after the successful completion of the Gravity Recovery and Interior Laboratory (GRAIL) mission in 2012.

  12. Wireless sensor platform

    Science.gov (United States)

    Joshi, Pooran C.; Killough, Stephen M.; Kuruganti, Phani Teja

    2017-08-08

    A wireless sensor platform and methods of manufacture are provided. The platform involves providing a plurality of wireless sensors, where each of the sensors is fabricated on flexible substrates using printing techniques and low temperature curing. Each of the sensors can include planar sensor elements and planar antennas defined using the printing and curing. Further, each of the sensors can include a communications system configured to encode the data from the sensors into a spread spectrum code sequence that is transmitted to a central computer(s) for use in monitoring an area associated with the sensors.

  13. Windows Azure Platform

    CERN Document Server

    Redkar, Tejaswi

    2010-01-01

    The Azure Services Platform is a brand-new cloud-computing technology from Microsoft. It is composed of four core components-Windows Azure, .NET Services, SQL Services, and Live Services-each with a unique role in the functioning of your cloud service. It is the goal of this book to show you how to use these components, both separately and together, to build flawless cloud services. At its heart Windows Azure Platform is a down-to-earth, code-centric book. This book aims to show you precisely how the components are employed and to demonstrate the techniques and best practices you need to know

  14. Windows Azure Platform

    CERN Document Server

    Redkar, Tejaswi

    2011-01-01

    The Windows Azure Platform has rapidly established itself as one of the most sophisticated cloud computing platforms available. With Microsoft working to continually update their product and keep it at the cutting edge, the future looks bright - if you have the skills to harness it. In particular, new features such as remote desktop access, dynamic content caching and secure content delivery using SSL make the latest version of Azure a more powerful solution than ever before. It's widely agreed that cloud computing has produced a paradigm shift in traditional architectural concepts by providin

  15. Workshop on polarized neutron filters and polarized pulsed neutron experiments

    International Nuclear Information System (INIS)

    Itoh, Shinichi

    2004-07-01

    The workshop was held in KEK by thirty-three participants on April 26, 2004. The polarized neutron filter method was only discussed. It consists of three parts; the first part was discussed on the polarized neutron methods, the second part on the polarized neutron experiments and the third on the pulse neutron spectrometer and polarized neutron experiments. The six papers were presented such as the polarized 3 He neutron spin filter, neutron polarization by proton polarized filter, soft master and neutron scattering, polarized neutron in solid physics, polarization experiments by chopper spectroscope and neutron polarization system in superHRPD. (S.Y.)

  16. Local orbitals by minimizing powers of the orbital variance

    DEFF Research Database (Denmark)

    Jansik, Branislav; Høst, Stinne; Kristensen, Kasper

    2011-01-01

    's correlation consistent basis sets, it is seen that for larger penalties, the virtual orbitals become more local than the occupied ones. We also show that the local virtual HF orbitals are significantly more local than the redundant projected atomic orbitals, which often have been used to span the virtual...

  17. Gate-dependent spin-orbit coupling in multielectron carbon nanotubes

    DEFF Research Database (Denmark)

    Jespersen, Thomas Sand; Grove-Rasmussen, Kasper; Paaske, Jens

    2011-01-01

    Understanding how the orbital motion of electrons is coupled to the spin degree of freedom in nanoscale systems is central for applications in spin-based electronics and quantum computation. Here we demonstrate such spin–orbit coupling in a carbon-nanotube quantum dot in the general multielectron...... graphene lattice. Our findings suggest that the spin–orbit coupling is a general property of carbon-nanotube quantum dots, which should provide a unique platform for the study of spin–orbit effects and their applications....

  18. GOC: General Orbit Code

    International Nuclear Information System (INIS)

    Maddox, L.B.; McNeilly, G.S.

    1979-08-01

    GOC (General Orbit Code) is a versatile program which will perform a variety of calculations relevant to isochronous cyclotron design studies. In addition to the usual calculations of interest (e.g., equilibrium and accelerated orbits, focusing frequencies, field isochronization, etc.), GOC has a number of options to calculate injections with a charge change. GOC provides both printed and plotted output, and will follow groups of particles to allow determination of finite-beam properties. An interactive PDP-10 program called GIP, which prepares input data for GOC, is available. GIP is a very easy and convenient way to prepare complicated input data for GOC. Enclosed with this report are several microfiche containing source listings of GOC and other related routines and the printed output from a multiple-option GOC run

  19. An integrated platform for biomolecule interaction analysis

    Science.gov (United States)

    Jan, Chia-Ming; Tsai, Pei-I.; Chou, Shin-Ting; Lee, Shu-Sheng; Lee, Chih-Kung

    2013-02-01

    We developed a new metrology platform which can detect real-time changes in both a phase-interrogation mode and intensity mode of a SPR (surface plasmon resonance). We integrated a SPR and ellipsometer to a biosensor chip platform to create a new biomolecular interaction measurement mechanism. We adopted a conductive ITO (indium-tinoxide) film to the bio-sensor platform chip to expand the dynamic range and improve measurement accuracy. The thickness of the conductive film and the suitable voltage constants were found to enhance performance. A circularly polarized ellipsometry configuration was incorporated into the newly developed platform to measure the label-free interactions of recombinant human C-reactive protein (CRP) with immobilized biomolecule target monoclonal human CRP antibody at various concentrations. CRP was chosen as it is a cardiovascular risk biomarker and is an acute phase reactant as well as a specific prognostic indicator for inflammation. We found that the sensitivity of a phaseinterrogation SPR is predominantly dependent on the optimization of the sample incidence angle. The effect of the ITO layer effective index under DC and AC effects as well as an optimal modulation were experimentally performed and discussed. Our experimental results showed that the modulated dynamic range for phase detection was 10E-2 RIU based on a current effect and 10E-4 RIU based on a potential effect of which a 0.55 (°/RIU) measurement was found by angular-interrogation. The performance of our newly developed metrology platform was characterized to have a higher sensitivity and less dynamic range when compared to a traditional full-field measurement system.

  20. Orbital debris: a technical assessment

    National Research Council Canada - National Science Library

    Committee on Space Debris, National Research Council

    ..., and other debris created as a byproduct of space operations. Orbital Debris examines the methods we can use to characterize orbital debris, estimates the magnitude of the debris population, and assesses the hazard that this population poses to spacecraft...

  1. Light-induced spin polarizations in quantum rings

    NARCIS (Netherlands)

    Joibari, F.K.; Blanter, Y.M.; Bauer, G.E.W.

    2014-01-01

    Nonresonant circularly polarized electromagnetic radiation can exert torques on magnetizations by the inverse Faraday effect (IFE). Here, we discuss the enhancement of IFE by spin-orbit interactions. We illustrate the principle by studying a simple generic model system, i.e., the

  2. The Creative Platform

    DEFF Research Database (Denmark)

    Byrge, Christian; Hansen, Søren

    whether you consider thirdgrade teaching, human-resource development, or radical new thinking in product development in a company. The Creative Platform was developed at Aalborg University through a series of research-and-development activities in collaboration with educational institutions and private...

  3. Creative Platform Learning (CPL)

    DEFF Research Database (Denmark)

    Christensen, Jonna Langeland; Hansen, Søren

    Creative Platform Learning (CPL) er en pædagogisk metode, der skaber foretagsomme og innovative elever, der kan anvende deres kreativitet til at lære nyt. Ifølge den nye skolereform skal Innovation og entreprenørskab tydeliggøres i alle fag. I CPL er det en integreret del af undervisningen...

  4. Games and Platform Decisions

    DEFF Research Database (Denmark)

    Hansen, Poul H. Kyvsgård; Mikkola, Juliana Hsuan

    2007-01-01

    is the application of on-line games in order to provide training for decision makers and in order to generate overview over the implications of platform decisions. However, games have to be placed in a context with other methods and we argue that a mixture of games, workshops, and simulations can provide improved...

  5. Shot loading platform analysis

    International Nuclear Information System (INIS)

    Norman, B.F.

    1994-01-01

    This document provides the wind/seismic analysis and evaluation for the shot loading platform. Hand calculations were used for the analysis. AISC and UBC load factors were used in this evaluation. The results show that the actual loads are under the allowable loads and all requirements are met

  6. Brake for rollable platform

    Science.gov (United States)

    Morris, A. L.

    1974-01-01

    Frame-mounted brake is independent of wheels and consists of simple lever-actuated foot. Brake makes good contact with surface even though foot pad is at higher or lower level than wheels, this is particularly important when a rollable platform is used on irregular surface.

  7. CERN Neutrino Platform Hardware

    CERN Document Server

    Nelson, Kevin

    2017-01-01

    My summer research was broadly in CERN's neutrino platform hardware efforts. This project had two main components: detector assembly and data analysis work for ICARUS. Specifically, I worked on assembly for the ProtoDUNE project and monitored the safety of ICARUS as it was transported to Fermilab by analyzing the accelerometer data from its move.

  8. Progress in measurement and understanding of beam polarization in electron positron storage rings

    International Nuclear Information System (INIS)

    Barber, D.P.; Bremer, H.D.; Kewisch, J.; Lewin, H.C.; Limberg, T.; Mais, H.; Ripken, G.; Rossmanith, R.; Schmidt, R.

    1983-07-01

    A report is presented on the status of attempts to obtain and measure spin polarization in electron-positron storage rings. Experimental results are presented and their relationship to predictions of calculations discussed. Examples of methods for decoupling orbital and spin motion and thus improving polarization are discussed. (orig.)

  9. Non-perturbative calculation of equilibrium polarization of stored electron beams

    International Nuclear Information System (INIS)

    Yokoya, Kaoru.

    1992-05-01

    Stored electron/positron beams polarize spontaneously owing to the spin-flip synchrotron radiation. In the existing computer codes, the degree of the equilibrium polarization has been calculated using perturbation expansions in terms of the orbital oscillation amplitudes. In this paper a new numerical method is presented which does not employ the perturbation expansion. (author)

  10. The HERA polarimeter and the first observation of electron spin polarization at HERA

    International Nuclear Information System (INIS)

    Barber, D.P.; Bremer, H.D.; Boege, M.; Brinkmann, R.; Gianfelice-Wendt, E.; Kaiser, H.; Klanner, R.; Lewin, H.C.; Meyners, N.; Vogel, W.; Brueckner, W.; Buescher, C.; Dueren, M.; Gaul, H.G.; Muecklich, A.; Neunreither, F.; Rith, K.; Scholz, C.; Steffens, E.; Veltri, M.; Wander, W.; Zapfe, K.; Zetsche, F.; Chapman, M.; Milner, R.; Coulter, K.; Delheij, P.P.J.; Haeusser, O.; Henderson, R.; Levy, P.; Vetterli, M.; Gressmann, H.; Janke, T.; Micheel, B.; Westphal, D.; Kaiser, R.; Losev, L.; Nowak, W.D.

    1992-10-01

    Electron spin polarizations of about 8% were observed at HERA in November 1991. In runs during 1992 utilizing special orbit corrections, polarization values close to 60% have been achieved. In this paper the polarimeter, the machine conditions, the data analysis, the first results and plans for future measurements are described. (orig.)

  11. A comparison of Doppler lidar wind sensors for Earth-orbit global measurement applications

    Science.gov (United States)

    Menzies, Robert T.

    1985-01-01

    Now, there are four Doppler lidar configurations which are being promoted for the measurement of tropospheric winds: (1) the coherent CO2 Lidar, operating in the 9 micrometer region using a pulsed, atmospheric pressure CO2 gas discharge laser transmitter, and heterodyne detection; (2) the coherent Neodymium doped YAG or Glass Lidar, operating at 1.06 micrometers, using flashlamp or diode laser optical pumping of the solid state laser medium, and heterodyne detection; (3) the Neodymium doped YAG/Glass Lidar, operating at the doubled frequency (at 530 nm wavelength), again using flashlamp or diode laser pumping of the laser transmitter, and using a high resolution tandem Fabry-Perot filter and direct detection; and (4) the Raman shifted Xenon Chloride Lidar, operating at 350 nm wavelength, using a pulsed, atmospheric pressure XeCl gas discharge laser transmitter at 308 nm, Raman shifted in a high pressure hydrogen cell to 350 nm in order to avoid strong stratospheric ozone absorption, also using a high resolution tandem Fabry-Perot filter and direct detection. Comparisons of these four systems can include many factors and tradeoffs. The major portion of this comparison is devoted to efficiency. Efficiency comparisons are made by estimating the number of transmitted photons required for a single pulse wind velocity estimate of + or - 1 m/s accuracy in the middle troposphere, from an altitude of 800 km, which is assured to be reasonable for a polar orbiting platform.

  12. Orbiter OMS and RCS technology

    Science.gov (United States)

    Boudreaux, R. A.

    1982-01-01

    Orbiter Orbital Maneuver Subsystem (OMS) and Reaction Control Subsystem (RCS) tankage has proved to be highly successful in shuttle flights on-orbit propellant transfer tests were done. Tank qualification tests along with flight demonstrations were carried out future uses of storable propellants are cited.

  13. Multiphoton polarization Bremsstrahlung effect

    International Nuclear Information System (INIS)

    Golovinskij, P.A.

    2001-01-01

    A general approach to induced polarization effects was formulated on the basis of theory of many particles in a strong periodic field. Correlation with the perturbation theory is shown and the types of effective polarization potentials both for isolated atoms and ions, and for ions in plasma, are provided. State of art in the theory of forced polarization Bremsstrahlung effect is analyzed and some outlooks for further experimental and theoretical studies are outlined [ru

  14. Interaction between subdaily Earth rotation parameters and GPS orbits

    Science.gov (United States)

    Panafidina, Natalia; Seitz, Manuela; Hugentobler, Urs

    2013-04-01

    In processing GPS observations the geodetic parameters like station coordinates and ERPs (Earth rotation parameters) are estimated w.r.t. the celestial reference system realized by the satellite orbits. The interactions/correlations between estimated GPS orbis and other parameters may lead to numerical problems with the solution and introduce systematic errors in the computed values: the well known correlations comprise 1) the correlation between the orbital parameters determining the orientation of the orbital plane in inertial space and the nutation and 2) in the case of estimating ERPs with subdaily resolution the correlation between retrograde diurnal polar motion and nutation (and so the respective orbital elements). In this contribution we study the interaction between the GPS orbits and subdaily model for the ERPs. Existing subdaily ERP model recommended by the IERS comprises ~100 terms in polar motion and ~70 terms in Universal Time at diurnal and semidiurnal tidal periods. We use a long time series of daily normal equation systems (NEQ) obtaine from GPS observations from 1994 till 2007 where the ERPs with 1-hour resolution are transformed into tidal terms and the influence of the tidal terms with different frequencies on the estimated orbital parameters is considered. We found that although there is no algebraic correlation in the NEQ between the individual orbital parameters and the tidal terms, the changes in the amplitudes of tidal terms with periods close to 24 hours can be better accmodated by systematic changes in the orbital parameters than for tidal terms with other periods. Since the variation in Earth rotation with the period of siderial day (23.93h, tide K1) in terrestrial frame has in inertial space the same period as the period of revolution of GPS satellites, the K1 tidal term in polar motion is seen by the satellites as a permanent shift. The tidal terms with close periods (from ~24.13h to ~23.80h) are seen as a slow rotation of the

  15. Airborne Laser Polarization Sensor

    Science.gov (United States)

    Kalshoven, James, Jr.; Dabney, Philip

    1991-01-01

    Instrument measures polarization characteristics of Earth at three wavelengths. Airborne Laser Polarization Sensor (ALPS) measures optical polarization characteristics of land surface. Designed to be flown at altitudes of approximately 300 m to minimize any polarizing or depolarizing effects of intervening atmosphere and to look along nadir to minimize any effects depending on look angle. Data from measurements used in conjunction with data from ground surveys and aircraft-mounted video recorders to refine mathematical models used in interpretation of higher-altitude polarimetric measurements of reflected sunlight.

  16. Polarization of Be stars

    International Nuclear Information System (INIS)

    Johns, M.W.

    1975-01-01

    Linear polarization of starlight may be produced by electron scattering in the extended atmospheres of early type stars. Techniques are investigated for the measurement and interpretation of this polarization. Polarimetric observations were made of twelve visual double star systems in which at least one member was a B type star as a means of separating the intrinsic stellar polarization from the polarization produced in the interstellar medium. Four of the double stars contained a Be star. Evidence for intrinsic polarization was found in five systems including two of the Be systems, one double star with a short period eclipsing binary, and two systems containing only normal early type stars for which emission lines have not been previously reported. The interpretation of these observations in terms of individual stellar polarizations and their wavelength dependence is discussed. The theoretical basis for the intrinsic polarization of early type stars is explored with a model for the disk-like extended atmospheres of Be stars. Details of a polarimeter for the measurement of the linear polarization of astronomical point sources are also presented with narrow band (Δ lambda = 100A) measurements of the polarization of γ Cas from lambda 4000 to lambda 5800

  17. Polarization at SLC

    International Nuclear Information System (INIS)

    Swartz, M.L.

    1988-07-01

    The SLAC Linear Collider has been designed to readily accommodate polarized electron beams. Considerable effort has been made to implement a polarized source, a spin rotation system, and a system to monitor the beam polarization. Nearly all major components have been fabricated. At the current time, several source and polarimeter components have been installed. The installation and commissioning of the entire system will take place during available machine shutdown periods as the commissioning of SLC progresses. It is expected that a beam polarization of 45% will be achieved with no loss in luminosity. 13 refs., 15 figs

  18. Spin-polarized gapped Dirac spectrum of unsupported silicene

    Energy Technology Data Exchange (ETDEWEB)

    Podsiadły-Paszkowska, A., E-mail: agata.podsiadly@gmail.com; Krawiec, M., E-mail: mariusz.krawiec@umcs.pl

    2016-06-15

    Highlights: • Effects of spin–orbit interaction and atomic reconstruction of silicene on its electronic properties have been studied. • Spin-polarized gapped Dirac spectrum has been revealed. • Two different AFM phases have been obtained. - Abstract: We study effects of the spin–orbit interaction and the atomic reconstruction of silicene on its electronic spectrum. As an example we consider unsupported silicene pulled off from Pb(111) substrate. Using first principles density functional theory we show that the inversion symmetry broken arrangement of atoms and the spin–orbit interaction generate a spin-polarized electronic spectrum with an energy gap in the Dirac cone. These findings are particularly interesting in view of the quantum anomalous and quantum valley Hall effects and should be observable in weakly interacting silicene-substrate systems.

  19. Mobile Platforms and Development Environments

    CERN Document Server

    Helal, Sumi; Li, Wengdong

    2012-01-01

    Mobile platform development has lately become a technological war zone with extremely dynamic and fluid movement, especially in the smart phone and tablet market space. This Synthesis lecture is a guide to the latest developments of the key mobile platforms that are shaping the mobile platform industry. The book covers the three currently dominant native platforms -- iOS, Android and Windows Phone -- along with the device-agnostic HTML5 mobile web platform. The lecture also covers location-based services (LBS) which can be considered as a platform in its own right. The lecture utilizes a sampl

  20. A Versatile Integrated Ambient Ionization Source Platform

    Science.gov (United States)

    Ai, Wanpeng; Nie, Honggang; Song, Shiyao; Liu, Xiaoyun; Bai, Yu; Liu, Huwei

    2018-04-01

    The pursuit of high-throughput sample analysis from complex matrix demands development of multiple ionization techniques with complementary specialties. A versatile integrated ambient ionization source (iAmIS) platform is proposed in this work, based on the idea of integrating multiple functions, enhancing the efficiency of current ionization techniques, extending the applications, and decreasing the cost of the instrument. The design of the iAmIS platform combines flowing atmospheric pressure afterglow (FAPA) source/direct analysis in real time (DART), dielectric barrier discharge ionization (DBDI)/low-temperature plasma (LTP), desorption electrospray ionization (DESI), and laser desorption (LD) technique. All individual and combined ionization modes can be easily attained by modulating parameters. In particular, the FAPA/DART&DESI mode can realize the detection of polar and nonpolar compounds at the same time with two different ionization mechanisms: proton transfer and charge transfer. The introduction of LD contributes to the mass spectrometry imaging and the surface-assisted laser desorption (SALDI) under ambient condition. Compared with other individual or multi-mode ion source, the iAmIS platform provides the flexibility of choosing different ionization modes, broadens the scope of the analyte detection, and facilitates the analysis of complex samples. [Figure not available: see fulltext.

  1. Hybrid Photonic Integration on a Polymer Platform

    Directory of Open Access Journals (Sweden)

    Ziyang Zhang

    2015-09-01

    Full Text Available To fulfill the functionality demands from the fast developing optical networks, a hybrid integration approach allows for combining the advantages of various material platforms. We have established a polymer-based hybrid integration platform (polyboard, which provides flexible optical input/ouptut interfaces (I/Os that allow robust coupling of indium phosphide (InP-based active components, passive insertion of thin-film-based optical elements, and on-chip attachment of optical fibers. This work reviews the recent progress of our polyboard platform. On the fundamental level, multi-core waveguides and polymer/silicon nitride heterogeneous waveguides have been fabricated, broadening device design possibilities and enabling 3D photonic integration. Furthermore, 40-channel optical line terminals and compact, bi-directional optical network units have been developed as highly functional, low-cost devices for the wavelength division multiplexed passive optical network. On a larger scale, thermo-optic elements, thin-film elements and an InP gain chip have been integrated on the polyboard to realize a colorless, dual-polarization optical 90° hybrid as the frontend of a coherent receiver. For high-end applications, a wavelength tunable 100Gbaud transmitter module has been demonstrated, manifesting the joint contribution from the polyboard technology, high speed polymer electro-optic modulator, InP driver electronics and ceramic electronic interconnects.

  2. Evaluation of Extraction Protocols for Simultaneous Polar and Non-Polar Yeast Metabolite Analysis Using Multivariate Projection Methods

    Directory of Open Access Journals (Sweden)

    Nicolas P. Tambellini

    2013-07-01

    Full Text Available Metabolomic and lipidomic approaches aim to measure metabolites or lipids in the cell. Metabolite extraction is a key step in obtaining useful and reliable data for successful metabolite studies. Significant efforts have been made to identify the optimal extraction protocol for various platforms and biological systems, for both polar and non-polar metabolites. Here we report an approach utilizing chemoinformatics for systematic comparison of protocols to extract both from a single sample of the model yeast organism Saccharomyces cerevisiae. Three chloroform/methanol/water partitioning based extraction protocols found in literature were evaluated for their effectiveness at reproducibly extracting both polar and non-polar metabolites. Fatty acid methyl esters and methoxyamine/trimethylsilyl derivatized aqueous compounds were analyzed by gas chromatography mass spectrometry to evaluate non-polar or polar metabolite analysis. The comparative breadth and amount of recovered metabolites was evaluated using multivariate projection methods. This approach identified an optimal protocol consisting of 64 identified polar metabolites from 105 ion hits and 12 fatty acids recovered, and will potentially attenuate the error and variation associated with combining metabolite profiles from different samples for untargeted analysis with both polar and non-polar analytes. It also confirmed the value of using multivariate projection methods to compare established extraction protocols.

  3. Photo-Induced Electron Spin Polarization in a Narrow Band Gap Semiconductor Nanostructure

    International Nuclear Information System (INIS)

    Peter, A. John; Lee, Chang Woo

    2012-01-01

    Photo-induced spin dependent electron transmission through a narrow gap InSb/InGa x Sb 1−x semiconductor symmetric well is theoretically studied using transfer matrix formulism. The transparency of electron transmission is calculated as a function of electron energy for different concentrations of gallium. Enhanced spin-polarized photon assisted resonant tunnelling in the heterostructure due to Dresselhaus and Rashba spin-orbit coupling induced splitting of the resonant level and compressed spin-polarization are observed. Our results show that Dresselhaus spin-orbit coupling is dominant for the photon effect and the computed polarization efficiency increases with the photon effect and the gallium concentration

  4. Valley polarization in magnetically doped single-layer transition-metal dichalcogenides

    KAUST Repository

    Cheng, Yingchun

    2014-04-28

    We demonstrate that valley polarization can be induced and controlled in semiconducting single-layer transition-metal dichalcogenides by magnetic doping, which is important for spintronics, valleytronics, and photonics devices. As an example, we investigate Mn-doped MoS2 by first-principles calculations. We study how the valley polarization depends on the strength of the spin orbit coupling and the exchange interaction and discuss how it can be controlled by magnetic doping. Valley polarization by magnetic doping is also expected for other honeycomb materials with strong spin orbit coupling and the absence of inversion symmetry.

  5. Platform Performance and Challenges - using Platforms in Lego Company

    DEFF Research Database (Denmark)

    Munk, Lone; Mortensen, Niels Henrik

    2009-01-01

    needs focus on the incentive of using the platform. This problem lacks attention in literature, as well as industry, where assessment criteria do not cover this aspect. Therefore, we recommend including user incentive in platform assessment criteria to these challenges. Concrete solution elements...... ensuring user incentive in platforms is an object for future research...

  6. Quantifying the importance of orbital over spin correlations in delta-Pu within density-functional theory

    International Nuclear Information System (INIS)

    Soderlind, P

    2008-01-01

    The electronic structure of plutonium is studied within the density-functional theory (DFT) model. Key features of the electronic structure are correctly modeled and bonding, total energy, and electron density of states are all consistent with measure data, although the prediction of magnetism is not consistent with many observations. Here we analyze the contributions to the electronic structure arising from spin polarization, orbital polarization, and spin-orbit interaction. These effects give rise to spin and orbital moments that are of nearly equal magnitude, but anti-parallel, suggesting a magnetic-moment cancellation with a zero total moment. Quantifying the spin versus orbital effects on the bonding, total energy, and electron spectra it becomes clear that the spin polarization is much less important than the orbital correlations. Consequently, a restricted DFT approach with a non-spin polarized electronic structure can produce reasonable equation-of-state and electron spectra for (delta)-Pu when the orbital effects are accounted for. Hence, we present two non-magnetic models. One in which the spin moment is canceled by the orbital moment and another in which the spin moment (and therefore the orbital moment) is restricted to zero

  7. Orbit Propagation and Determination of Low Earth Orbit Satellites

    Directory of Open Access Journals (Sweden)

    Ho-Nien Shou

    2014-01-01

    Full Text Available This paper represents orbit propagation and determination of low Earth orbit (LEO satellites. Satellite global positioning system (GPS configured receiver provides position and velocity measures by navigating filter to get the coordinates of the orbit propagation (OP. The main contradictions in real-time orbit which is determined by the problem are orbit positioning accuracy and the amount of calculating two indicators. This paper is dedicated to solving the problem of tradeoffs. To plan to use a nonlinear filtering method for immediate orbit tasks requires more precise satellite orbit state parameters in a short time. Although the traditional extended Kalman filter (EKF method is widely used, its linear approximation of the drawbacks in dealing with nonlinear problems was especially evident, without compromising Kalman filter (unscented Kalman Filter, UKF. As a new nonlinear estimation method, it is measured at the estimated measurements on more and more applications. This paper will be the first study on UKF microsatellites in LEO orbit in real time, trying to explore the real-time precision orbit determination techniques. Through the preliminary simulation results, they show that, based on orbit mission requirements and conditions using UKF, they can satisfy the positioning accuracy and compute two indicators.

  8. Four Years on Orbit at the Moon with LOLA

    Science.gov (United States)

    Smith, D. E.; Zuber, M. T.; Neumann, G. A.; Mazarico, E.; Torrence, M. H.; Lemoine, F. G.

    2013-12-01

    After four years of near-continuous operation at the Moon, the Lunar Orbiter Laser Altimeter (LOLA) continues to collect altimetry, surface roughness, slope and normal reflectance data. Although the instrument is beginning to show the effects of tens of thousands of thermal cycles and the natural process of the aging of the laser transmitters, LOLA continues to acquire data on the sunlit portion of every orbit on all 5 laser beams when below 100-km altitude. LOLA has acquired over 6x10^9 altimeter measurements, all geodetically controlled to the center-of-mass of the Moon with a radial precision of around 10 cm and an accuracy of about 1 meter. The position of the measurements on the lunar surface is primarily limited by the knowledge of the position of the spacecraft in orbit; in the last year the LRO orbit accuracy has improved significantly as a result of the availability of an accurate gravity model of the Moon from the GRAIL Discovery mission. Our present estimate of positional accuracy is less than 10 m rms but is only achievable with a GRAIL gravity model to at least degree and order 600 because of the perturbing gravitational effect of the Moon's surface features. Significant improvements in the global shape and topography have assisted the Lunar Reconnaissance Orbiter Camera (LROC) stereo mapping program, and the identification of potential lunar landing sites for ESA and Russia, particularly in the high-latitude polar regions where 5- and 10-meter average horizontal resolution has been obtained. LOLA's detailed mapping of the polar regions has improved the delineation of permanently-shadowed areas and assisted in the understanding of the LEND neutron data and its relationship to surface slopes. Recently, a global, calibrated LOLA normal albedo dataset at 1064 nm has been developed and is being combined with analysis and modeling by the Diviner team for the identification of the coldest locations in the polar regions.

  9. Available: motorised platform

    CERN Multimedia

    The COMPASS collaboration

    2014-01-01

    The COMPASS collaboration would like to offer to a new owner the following useful and fully operational piece of equipment, which is due to be replaced with better adapted equipment.   Please contact Erwin Bielert (erwin.bielert@cern.ch or 160539) for further information.  Motorized platform (FOR FREE):   Fabricated by ACL (Alfredo Cardoso & Cia Ltd) in Portugal. The model number is MeXs 5-­‐30.  Specifications: 5 m wide, 1 m deep, adjustable height (1.5 m if folded). Maximum working floor height: 4 m. conforms to CERN regulations, number LV158. Type LD500, capacity 500 kg and weight 2000 kg.  If no interested party is found before December 2014, the platform will be thrown away.

  10. RemoteLabs Platform

    Directory of Open Access Journals (Sweden)

    Nils Crabeel

    2012-03-01

    Full Text Available This paper reports on a first step towards the implementation of a framework for remote experimentation of electric machines – the RemoteLabs platform. This project was focused on the development of two main modules: the user Web-based and the electric machines interfaces. The Web application provides the user with a front-end and interacts with the back-end – the user and experiment persistent data. The electric machines interface is implemented as a distributed client server application where the clients, launched by the Web application, interact with the server modules located in platforms physically connected the electric machines drives. Users can register and authenticate, schedule, specify and run experiments and obtain results in the form of CSV, XML and PDF files. These functionalities were successfully tested with real data, but still without including the electric machines. This inclusion is part of another project scheduled to start soon.

  11. Common tester platform concept.

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, Michael James

    2008-05-01

    This report summarizes the results of a case study on the doctrine of a common tester platform, a concept of a standardized platform that can be applicable across the broad spectrum of testing requirements throughout the various stages of a weapons program, as well as across the various weapons programs. The common tester concept strives to define an affordable, next-generation design that will meet testing requirements with the flexibility to grow and expand; supporting the initial development stages of a weapons program through to the final production and surveillance stages. This report discusses a concept investing key leveraging technologies and operational concepts combined with prototype tester-development experiences and practical lessons learned gleaned from past weapons programs.

  12. Online stock trading platform

    Directory of Open Access Journals (Sweden)

    Ion LUNGU

    2006-01-01

    Full Text Available The Internet is the perfect tool that can assure the market’s transparency for any user who wants to trade on the stock market. The investor can have access to the market news, financial calendar or the press releases of the issuers. A good online trading platform also provides real-time intraday quotes, trading history and technical analysis giving the investor a clearer view of the supply and demand in the market. All this information provides the investor a good image of the market and encourages him to trade. This paper wishes to draft the pieces of an online trading platform and to analyze the impact of developing and implementing one in a brokerage firm.

  13. TRANSVERSELY POLARIZED Λ PRODUCTION

    International Nuclear Information System (INIS)

    BORER, D.

    2000-01-01

    Transversely polarized Λ production in hard scattering processes is discussed in terms of a leading twist T-odd fragmentation function which describes the fragmentation of an unpolarized quark into a transversely polarized Λ. We focus on the properties of this function and its relevance for the RHIC and HERMES experiments

  14. Our Polar Past

    Science.gov (United States)

    Clary, Renee; Wandersee, James

    2009-01-01

    The study of polar exploration is fascinating and offers students insights into the history, culture, and politics that affect the developing sciences at the farthest ends of Earth. Therefore, the authors think there is value in incorporating polar exploration accounts within modern science classrooms, and so they conducted research to test their…

  15. Marine polar steroids

    International Nuclear Information System (INIS)

    Stonik, Valentin A

    2001-01-01

    Structures, taxonomic distribution and biological activities of polar steroids isolated from various marine organisms over the last 8-10 years are considered. The peculiarities of steroid biogenesis in the marine biota and their possible biological functions are discussed. Syntheses of some highly active marine polar steroids are described. The bibliography includes 254 references.

  16. Polarized proton beams

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    The acceleration of polarized proton beams in circular accelerators is complicated by the presence of numerous depolarizing spin resonances. Careful and tedious minimization of polarization loss at each of these resonances allowed acceleration of polarized proton beams up to 22 GeV. It has been the hope that Siberian Snakes, which are local spin rotators inserted into ring accelerators, would eliminate these resonances and allow acceleration of polarized beams with the same ease and efficiency that is now routine for unpolarized beams. First tests at IUCF with a full Siberian Snake showed that the spin dynamics with a Snake can be understood in detail. The author now has results of the first tests of a partial Siberian Snake at the AGS, accelerating polarized protons to an energy of about 25 GeV. These successful tests of storage and acceleration of polarized proton beams open up new possibilities such as stored polarized beams for internal target experiments and high energy polarized proton colliders

  17. HPC - Platforms Penta Chart

    Energy Technology Data Exchange (ETDEWEB)

    Trujillo, Angelina Michelle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-10-08

    Strategy, Planning, Acquiring- very large scale computing platforms come and go and planning for immensely scalable machines often precedes actual procurement by 3 years. Procurement can be another year or more. Integration- After Acquisition, machines must be integrated into the computing environments at LANL. Connection to scalable storage via large scale storage networking, assuring correct and secure operations. Management and Utilization – Ongoing operations, maintenance, and trouble shooting of the hardware and systems software at massive scale is required.

  18. Cloud Robotics Platforms

    Directory of Open Access Journals (Sweden)

    Busra Koken

    2015-01-01

    Full Text Available Cloud robotics is a rapidly evolving field that allows robots to offload computation-intensive and storage-intensive jobs into the cloud. Robots are limited in terms of computational capacity, memory and storage. Cloud provides unlimited computation power, memory, storage and especially collaboration opportunity. Cloud-enabled robots are divided into two categories as standalone and networked robots. This article surveys cloud robotic platforms, standalone and networked robotic works such as grasping, simultaneous localization and mapping (SLAM and monitoring.

  19. Cassini UVIS Observations of Saturn during the Grand Finale Orbits

    Science.gov (United States)

    Pryor, W. R.; Esposito, L. W.; West, R. A.; Jouchoux, A.; Radioti, A.; Grodent, D. C.; Gerard, J. C. M. C.; Gustin, J.; Lamy, L.; Badman, S. V.

    2017-12-01

    In 2016 and 2017, the Cassini Saturn orbiter executed a final series of high inclination, low-periapsis orbits ideal for studies of Saturn's polar regions. The Cassini Ultraviolet Imaging Spectrograph (UVIS) obtained an extensive set of auroral images, some at the highest spatial resolution obtained during Cassini's long orbital mission (2004-2017). In some cases, two or three spacecraft slews at right angles to the long slit of the spectrograph were required to cover the entire auroral region to form auroral images. We will present selected images from this set showing narrow arcs of emission, more diffuse auroral emissions, multiple auroral arcs in a single image, discrete spots of emission, small scale vortices, large-scale spiral forms, and parallel linear features that appear to cross in places like twisted wires. Some shorter features are transverse to the main auroral arcs, like barbs on a wire. UVIS observations were in some cases simultaneous with auroral observations from the Hubble Space Telescope Space Telescope Imaging Spectrograph (STIS) that will also be presented. UVIS polar images also contain spectral information suitable for studies of the auroral electron energy distribution. The long wavelength part of the UVIS polar images contains a signal from reflected sunlight containing absorption signatures of acetylene and other Saturn hydrocarbons. The hydrocarbon spatial distribution will also be examined.

  20. Jupiter's Magnetic Field and Magnetosphere after Juno's First 8 Orbits

    Science.gov (United States)

    Connerney, J. E. P.; Oliversen, R. J.; Espley, J. R.; Gruesbeck, J.; Kotsiaros, S.; DiBraccio, G. A.; Joergensen, J. L.; Joergensen, P. S.; Merayo, J. M. G.; Denver, T.; Benn, M.; Bjarno, J. B.; Malinnikova Bang, A.; Bloxham, J.; Moore, K.; Bolton, S. J.; Levin, S.; Gershman, D. J.

    2017-12-01

    The Juno spacecraft entered polar orbit about Jupiter on July 4, 2016, embarking upon an ambitious mission to map Jupiter's magnetic and gravitational potential fields and probe its deep atmosphere, in search of clues to the planet's formation and evolution. Juno is also instrumented to conduct the first exploration of the polar magnetosphere and to acquire images and spectra of its polar auroras and atmosphere. Juno's 53.5-day orbit trajectory carries her science instruments from pole to pole in approximately 2 hours, with a closest approach to within 1.05 Rj of the center of the planet (one Rj = 71,492 km, Jupiter's equatorial radius), just a few thousand km above the clouds. Repeated periapsis passes will eventually encircle the planet with a dense net of observations equally spaced in longitude (magnetometer sensor suites, located 10 and 12 m from the center of the spacecraft at the end of one of Juno's three solar panel wings. Each contains a vector fluxgate magnetometer (FGM) sensor and a pair of co-located non-magnetic star tracker camera heads, providing accurate attitude determination for the FGM sensors. We present an overview of the magnetometer observations obtained during Juno's first year in orbit in context with prior observations and those acquired by Juno's other science instruments.

  1. The Prodiguer Messaging Platform

    Science.gov (United States)

    Denvil, S.; Greenslade, M. A.; Carenton, N.; Levavasseur, G.; Raciazek, J.

    2015-12-01

    CONVERGENCE is a French multi-partner national project designed to gather HPC and informatics expertise to innovate in the context of running French global climate models with differing grids and at differing resolutions. Efficient and reliable execution of these models and the management and dissemination of model output are some of the complexities that CONVERGENCE aims to resolve.At any one moment in time, researchers affiliated with the Institut Pierre Simon Laplace (IPSL) climate modeling group, are running hundreds of global climate simulations. These simulations execute upon a heterogeneous set of French High Performance Computing (HPC) environments. The IPSL's simulation execution runtime libIGCM (library for IPSL Global Climate Modeling group) has recently been enhanced so as to support hitherto impossible realtime use cases such as simulation monitoring, data publication, metrics collection, simulation control, visualizations … etc. At the core of this enhancement is Prodiguer: an AMQP (Advanced Message Queue Protocol) based event driven asynchronous distributed messaging platform. libIGCM now dispatches copious amounts of information, in the form of messages, to the platform for remote processing by Prodiguer software agents at IPSL servers in Paris. Such processing takes several forms: Persisting message content to database(s); Launching rollback jobs upon simulation failure; Notifying downstream applications; Automation of visualization pipelines; We will describe and/or demonstrate the platform's: Technical implementation; Inherent ease of scalability; Inherent adaptiveness in respect to supervising simulations; Web portal receiving simulation notifications in realtime.

  2. Spin motion at and near orbital resonance in storage rings with Siberian snakes I. At orbital resonance

    International Nuclear Information System (INIS)

    Barber, D.P.; Vogt, M.

    2006-12-01

    Here, and in a sequel, we invoke the invariant spin field to provide an in-depth study of spin motion at and near low order orbital resonances in a simple model for the effects of vertical betatron motion in a storage ring with Siberian Snakes. This leads to a clear understanding, within the model, of the behaviour of the beam polarization at and near so-called snake resonances in proton storage rings. (orig.)

  3. Polarization Optics in Telecommunications

    CERN Document Server

    Damask, Jay N

    2005-01-01

    The strong investments into optical telecommunications in the late 1990s resulted in a wealth of new research, techniques, component designs, and understanding of polarization effects in fiber. Polarization Optics in Telecommunications brings together recent advances in the field to create a standard, practical reference for component designers and optical fiber communication engineers. Beginning with a sound foundation in electromagnetism, the author offers a dissertation of the spin-vector formalism of polarization and the interaction of light with media. Applications discussed include optical isolators, optical circulators, fiber collimators, and a variety of applied waveplate and prism combinations. Also included in an extended discussion of polarization-mode dispersion (PMD) and polarization-dependent loss (PDL), their representation, behavior, statistical properties, and measurement. This book draws extensively from the technical and patent literature and is an up-to-date reference for researchers and c...

  4. Parallel Polarization State Generation.

    Science.gov (United States)

    She, Alan; Capasso, Federico

    2016-05-17

    The control of polarization, an essential property of light, is of wide scientific and technological interest. The general problem of generating arbitrary time-varying states of polarization (SOP) has always been mathematically formulated by a series of linear transformations, i.e. a product of matrices, imposing a serial architecture. Here we show a parallel architecture described by a sum of matrices. The theory is experimentally demonstrated by modulating spatially-separated polarization components of a laser using a digital micromirror device that are subsequently beam combined. This method greatly expands the parameter space for engineering devices that control polarization. Consequently, performance characteristics, such as speed, stability, and spectral range, are entirely dictated by the technologies of optical intensity modulation, including absorption, reflection, emission, and scattering. This opens up important prospects for polarization state generation (PSG) with unique performance characteristics with applications in spectroscopic ellipsometry, spectropolarimetry, communications, imaging, and security.

  5. Study of the Polarization Strategy for Electron Cyclotron Heating Systems on HL-2M

    Science.gov (United States)

    Zhang, F.; Huang, M.; Xia, D. H.; Song, S. D.; Wang, J. Q.; Huang, B.; Wang, H.

    2016-06-01

    As important components integrated in transmission lines of electron cyclotron heating systems, polarizers are mainly used to obtain the desired polarization for highly efficient coupling between electron cyclotron waves and plasma. The polarization strategy for 105-GHz electron cyclotron heating systems of HL-2M tokamak is studied in this paper. Considering the polarizers need high efficiency, stability, and low loss to realize any polarization states, two sinusoidal-grooved polarizers, which include a linear polarizer and an elliptical polarizer, are designed with the coordinate transformation method. The parameters, the period p and the depth d, of two sinusoidal-grooved polarizers are optimized by a phase difference analysis method to achieve an almost arbitrary polarization. Finally, the optimized polarizers are manufactured and their polarization characteristics are tested with a low-power test platform. The experimental results agree well with the numerical calculations, indicating that the designed polarizers can meet the polarization requirements of the electron cyclotron heating systems of HL-2M tokamak.

  6. Coulomb-free and Coulomb-distorted recolliding quantum orbits in photoelectron holography

    Science.gov (United States)

    Maxwell, A. S.; Figueira de Morisson Faria, C.

    2018-06-01

    We perform a detailed analysis of the different types of orbits in the Coulomb quantum orbit strong-field approximation (CQSFA), ranging from direct to those undergoing hard collisions. We show that some of them exhibit clear counterparts in the standard formulations of the strong-field approximation for direct and rescattered above-threshold ionization, and show that the standard orbit classification commonly used in Coulomb-corrected models is over-simplified. We identify several types of rescattered orbits, such as those responsible for the low-energy structures reported in the literature, and determine the momentum regions in which they occur. We also find formerly overlooked interference patterns caused by backscattered Coulomb-corrected orbits and assess their effect on photoelectron angular distributions. These orbits improve the agreement of photoelectron angular distributions computed with the CQSFA with the outcome of ab initio methods for high energy phtotoelectrons perpendicular to the field polarization axis.

  7. High Power Microwave Emission of Large and Small Orbit Gyrotron Devices in Rectangular Interaction Structures

    Science.gov (United States)

    Hochman, J. M.; Gilgenbach, R. M.; Jaynes, R. L.; Rintamaki, J. I.; Luginsland, J. W.; Lau, Y. Y.; Spencer, T. A.

    1996-11-01

    Experiments utilize large and small orbit e-beam gyrotron devices in a rectangular-cross-section (RCS) gyrotron. This device is being explored to examine polarization control. Other research issues include pulse shortening, and mode competition. MELBA generates electron beams with parameters of: -800kV, 1-10kA diode current, and 0.5-1.0 μ sec pulselengths. The small orbit gyrotron device is converted to a large orbit experiment by running MELBA's annular electron beam through a magnetic cusp. Initial experiments showed an increase in beam alpha (V_perp/V_par) of a factor of ~ 4 between small and large orbit devices. Experimental results from the RCS gyrotron will be compared for large-orbit and small-orbit electron beams. Beam transport data and frequency measurements will be presented. Computer modeling utilizing the MAGIC and E-gun codes will be shown.

  8. Internuclear Separation Dependent Ionization of the Valence Orbitals of I2 by Strong Laser Fields

    Science.gov (United States)

    Chen, H.; Tagliamonti, V.; Gibson, G. N.

    2012-11-01

    Using a pump-dump-probe technique and Fourier-transform spectroscopy, we study the internuclear separation R dependence and relative strength of the ionization rates of the π and σ electrons of I2, whose valence orbitals are σg2πu4πg4σu0. We find that ionization of the highest occupied molecular orbital (HOMO)-2 (σg) has a strong dependence on R while the HOMO and HOMO-1 do not. Surprisingly, the ionization rate of the HOMO-2 exceeds the combined ionization rate of the less bound orbitals and this branching ratio increases with R. Since our technique produces target molecules that are highly aligned with the laser polarization, the σ orbitals will be preferentially ionized and undergo enhanced ionization at larger R compared to the π orbitals. Nevertheless, it is highly unusual that an inner orbital provides the dominant strong field ionization pathway in a small molecule.

  9. The orbital inclination of A0620 - 00 measured polarimetrically

    International Nuclear Information System (INIS)

    Dolan, J.F.; Tapia, S.

    1989-01-01

    The mass of the degenerate primary in A0620 - 00 is inferred from its spectroscopic mass function to be not less than 3.2 solar masses, making it an excellent candidate for a black hole. The exact value of the mass depends on the orbital inclination. The inclination of a binary system can be determined from the shape of its Stokes parameter light curves if the linear polarization of the system varies as a function of orbital phase. A0620 - 00 over one 8-hour binary period was observed with the 4.5-m equivalent MMT. Its polarization in the visible is variable with orbital phase. The standard theory of Brown et al. (1978) was used to derive an orbital inclination of i = 57 deg (+20 deg, -50 deg), where the error is the 90-percent confidence interval. An inclination of i = 57 deg corresponds to a mass of the compact primary of 6.6 solar masses, but the large uncertainty in the measured value of the inclination allows the derived mass of A0620 - 00 to be as low as 3.8 solar masses. If this is taken to be the maximum mass of any degenerate configuration consistent with general relativity except a black hole, then the mass of A0620 - 00 is still not well enough determined to conclude that it must be a black hole. 21 refs

  10. Utilizing platforms in industrialized construction

    DEFF Research Database (Denmark)

    Bonev, Martin; Wörösch, Michael; Hvam, Lars

    2015-01-01

    platform strategies, this researchhighlights key aspects of adapting platform-based developed theory to industrialised construction.Building projects use different layers of product, process and logistics platforms to form the right cost– value ratio for the target market application, while modelling...

  11. The polarized electron beam at ELSA

    International Nuclear Information System (INIS)

    Hoffmann, M.; Drachenfels, W. von; Frommberger, F.; Gowin, M.; Hillert, W.; Husmann, D.; Keil, J.; Helbing, K.; Michel, T.; Naumann, J.; Speckner, T.; Zeitler, G.

    2001-01-01

    The future medium energy physics program at the electron stretcher accelerator ELSA of Bonn University mainly relies on experiments using polarized electrons in the energy range from 1 to 3.2 GeV. To provide a polarized beam with high polarization and sufficient intensity a dedicated source has been developed and set into operation. To prevent depolarization during acceleration in the circular accelerators several depolarizing resonances have to be corrected for. Intrinsic resonances are compensated using two pulsed betatron tune jump quadrupoles. The influence of imperfection resonances is successfully reduced applying a dynamic closed orbit correction in combination with an empirical harmonic correction on the energy ramp. In order to minimize beam depolarization, both types of resonances and the correction techniques have been studied in detail. It turned out that the polarization in ELSA can be conserved up to 2.5 GeV and partially up to 3.2 GeV which is demonstrated by measurements using a Moeller polarimeter installed in the external GDH1-beamline

  12. Capsize of polarization in dilute photonic crystals.

    Science.gov (United States)

    Gevorkian, Zhyrair; Hakhoumian, Arsen; Gasparian, Vladimir; Cuevas, Emilio

    2017-11-29

    We investigate, experimentally and theoretically, polarization rotation effects in dilute photonic crystals with transverse permittivity inhomogeneity perpendicular to the traveling direction of waves. A capsize, namely a drastic change of polarization to the perpendicular direction is observed in a one-dimensional photonic crystal in the frequency range 10 ÷ 140 GHz. To gain more insights into the rotational mechanism, we have developed a theoretical model of dilute photonic crystal, based on Maxwell's equations with a spatially dependent two dimensional inhomogeneous dielectric permittivity. We show that the polarization's rotation can be explained by an optical splitting parameter appearing naturally in Maxwell's equations for magnetic or electric fields components. This parameter is an optical analogous of Rashba like spin-orbit interaction parameter present in quantum waves, introduces a correction to the band structure of the two-dimensional Bloch states, creates the dynamical phase shift between the waves propagating in the orthogonal directions and finally leads to capsizing of the initial polarization. Excellent agreement between theory and experiment is found.

  13. A Typical Presentation of Orbital Pseudotumor Mimicking Orbital Cellulitis

    Directory of Open Access Journals (Sweden)

    J. Ayatollahi

    2013-10-01

    Full Text Available Introduction: Orbital pseudotumor, also known as idiopathic orbital inflammatory syndrome (IOIS, is a benign, non- infective inflammatory condition of the orbit without identifiable local or systemic causes. The disease may mimics a variety of pathologic conditions. We pre-sent a case of pseudotumor observed in a patient admitted under the name of orbital celluli-ties. Case Report: A 26-year-old woman reffered to our hospital with the history of left ocular pain and headache 2 days before her visit.. Ophthalmological examination of the patient was normal except for the redness and lid edema, mild chemosis and conjunctival injection. Gen-eral assessment was normal but a low grade fever was observed. She was hospitalized as an orbital cellulitis patient. She was treated with intravenous antibiotics. On the third day , sud-denly diplopia, proptosis in her left eye and ocular pain in her right side appeared. MRI re-vealed bilateral enlargement of extraocular muscles. Diagnosis of orbital pseudotumor was made and the patient was treated with oral steroid.She responded promptly to the treatment. Antibiotics were discontinued and steroid was tapered in one month period under close fol-low up. Conclusion: The clinical features of orbital pseudotumor vary widely . Orbital pseudotumor and orbital cellulitis can occasionally demonstrate overlapping features.. Despite complete physical examination and appropriate imaging, sometimes correct diagnosis of the disease would be difficult (Sci J Hamadan Univ Med Sci 2013; 20 (3:256-259

  14. Techniques of production and analysis of polarized synchrotron radiation

    International Nuclear Information System (INIS)

    Mills, D.M.

    1992-01-01

    The use of the unique polarization properties of synchrotron radiation in the hard x-ray spectral region (E>3 KeV) is becoming increasingly important to many synchrotron radiation researchers. The radiation emitted from bending magnets and conventional (planar) insertion devices (IDs) is highly linearly polarized in the plane of the particle's orbit. Elliptically polarized x-rays can also be obtained by going off axis on a bending magnet source, albeit with considerable loss of flux. The polarization properties of synchrotron radiation can be further tailored to the researcher's specific needs through the use of specialized insertion devices such as helical and crossed undulators and asymmetrical wigglers. Even with the possibility of producing a specific polarization, there is still the need to develop x-ray optical components which can manipulate the polarization for both analysis and further modification of the polarization state. A survey of techniques for producing and analyzing both linear and circular polarized x-rays will be presented with emphasis on those techniques which rely on single crystal optical components

  15. Electrically polarized PLLA nanofibers as neural tissue engineering scaffolds with improved neuritogenesis.

    Science.gov (United States)

    Barroca, Nathalie; Marote, Ana; Vieira, Sandra I; Almeida, Abílio; Fernandes, Maria H V; Vilarinho, Paula M; da Cruz E Silva, Odete A B

    2018-07-01

    Tissue engineering is evolving towards the production of smart platforms exhibiting stimulatory cues to guide tissue regeneration. This work explores the benefits of electrical polarization to produce more efficient neural tissue engineering platforms. Poly (l-lactic) acid (PLLA)-based scaffolds were prepared as solvent cast films and electrospun aligned nanofibers, and electrically polarized by an in-lab built corona poling device. The characterization of the platforms by thermally stimulated depolarization currents reveals a polarization of 60 × 10 -10 C cm -2 that is stable on poled electrospun nanofibers for up to 6 months. Further in vitro studies using neuroblastoma cells reveals that platforms' polarization potentiates Retinoic Acid-induced neuronal differentiation. Additionally, in differentiating embryonic cortical neurons, poled aligned nanofibers further increased neurite outgrowth by 30% (+70 μm) over non-poled aligned nanofibers, and by 50% (+100 μm) over control conditions. Therefore, the synergy of topographical cues and electrical polarization of poled aligned nanofibers places them as promising biocompatible and bioactive platforms for neural tissue regeneration. Given their long lasting induced polarization, these PLLA poled nanofibrous scaffolds can be envisaged as therapeutic devices of long shelf life for neural repair applications. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Geometric phase due to orbit-orbit interaction: rotating LP11 modes in a two-mode fiber

    Science.gov (United States)

    Pradeep Chakravarthy, T.; Naik, Dinesh N.; Viswanathan, Nirmal K.

    2017-10-01

    Accumulation of geometric phase due to non-coplanar propagation of higher-order modes in an optical fiber is experimentally demonstrated. Vertically-polarized LP11 fiber mode, excited in a horizontally-held, torsion-free, step-index, two-mode optical fiber, rotates due to asymmetry in the propagating k-vectors, arising due to off-centered beam location at the fiber input. Perceiving the process as due to rotation of the fiber about the off-axis launch position, the orbital Berry phase accumulation upon scanning the launch position in a closed-loop around the fiber axis manifests as rotational Doppler effect, a consequence of orbit-orbit interaction. The anticipated phase accumulation as a function of the input launch position, observed through interferometry is connected to the mode rotation angle, quantified using the autocorrelation method.

  17. Polar bears at risk

    Energy Technology Data Exchange (ETDEWEB)

    Norris, S.; Rosentrater, L.; Eid, P.M. [WWF International Arctic Programme, Oslo (Norway)

    2002-05-01

    Polar bears, the world's largest terrestrial carnivore, spend much of their lives on the arctic sea ice. This is where they hunt and move between feeding, denning, and resting areas. The world population, estimated at 22,000 bears, is made up of 20 relatively distinct populations varying in size from a few hundred to a few thousand animals. About 60 per cent of all polar bears are found in Canada. In general, the status of this species is stable, although there are pronounced differences between populations. Reductions in the extent and thickness of sea ice has lead the IUCN Polar Bear Specialist Group to describe climate change as one of the major threats facing polar bears today. Though the long-term effects of climate change will vary in different areas of the Arctic, impacts on the condition and reproductive success of polar bears and their prey are likely to be negative. Longer ice-free periods resulting from earlier break-up of sea ice in the spring and later formation in the fall is already impacting polar bears in the southern portions of their range. In Canada's Hudson Bay, for example, bears hunt on the ice through the winter and into early summer, after which the ice melts completely, forcing bears ashore to fast on stored fat until freeze-up in the fall. The time bears have on the ice to hunt and build up their body condition is cut short when the ice melts early. Studies from Hudson Bay show that for every week earlier that ice break-up occurs, bears will come ashore 10 kg lighter and in poorer condition. It is likely that populations of polar bears dividing their time between land and sea will be severely reduced and local extinctions may occur as greenhouse gas emissions continue to rise and sea ice melts. Expected changes in regional weather patterns will also impact polar bears. Rain in the late winter can cause maternity dens to collapse before females and cubs have departed, thus exposing occupants to the elements and to predators. Such

  18. COMPASS polarized target for Drell-Yan

    CERN Document Server

    Pešek, M

    2014-01-01

    In the COMPASS Drell–Yan experiment the pion beam with momen tum of 190 GeV/ c and in- tensity up to 10 8 pions/s will interact with transversely polarized proton t arget producing muon pair via Drell–Yan process. The solid-state NH 3 will be polarized by dynamic nuclear polar- ization. Maximum polarization reached during data taking i s expected to be up to 90%. The non-interacting beam and other particles produced inside t he target will be stopped in the hadron absorber after the target. Two target cells, sepparated by a 20 cm gap in between, each 55 cm long and 4 cm in diameter give the target material volume about 691 cm 3 . The target platform needs to be moved by 2.3 m in upstream dire ction from the position used in previous experiments in order to accomodate the absorber. D uring the beam time higher radiation is expected in the area of the control room. Thus a new target r emote control system is needed. The target magnet is undergoing a substantial upgrade. Drell–Yan data taking is expected t...

  19. Spin and charge controlled by antisymmetric spin-orbit coupling in a triangular-triple-quantum-dot Kondo system

    Science.gov (United States)

    Koga, M.; Matsumoto, M.; Kusunose, H.

    2018-05-01

    We study a local antisymmetric spin-orbit (ASO) coupling effect on a triangular-triple-quantum-dot (TTQD) system as a theoretical proposal for a new application of the Kondo physics to nanoscale devices. The electric polarization induced by the Kondo effect is strongly correlated with the spin configurations and molecular orbital degrees of freedom in the TTQD. In particular, an abrupt sign reversal of the emergent electric polarization is associated with a quantum critical point in a magnetic field, which can also be controlled by the ASO coupling that changes the mixing weight of different orbital components in the TTQD ground state.

  20. Electrically tunable polarizer based on 2D orthorhombic ferrovalley materials

    Science.gov (United States)

    Shen, Xin-Wei; Tong, Wen-Yi; Gong, Shi-Jing; Duan, Chun-Gang

    2018-03-01

    The concept of ferrovalley materials has been proposed very recently. The existence of spontaneous valley polarization, resulting from ferromagnetism, in such hexagonal 2D materials makes nonvolatile valleytronic applications realizable. Here, we introduce a new member of ferrovalley family with orthorhombic lattice, i.e. monolayer group-IV monochalcogenides (GIVMs), in which the intrinsic valley polarization originates from ferroelectricity, instead of ferromagnetism. Combining the group theory analysis and first-principles calculations, we demonstrate that, different from the valley-selective circular dichroism in hexagonal lattice, linearly polarized optical selectivity for valleys exists in the new type of ferrovalley materials. On account of the distinctive property, a prototype of electrically tunable polarizer is realized. In the ferrovalley-based polarizer, a laser beam can be optionally polarized in x- or y-direction, depending on the ferrovalley state controlled by external electric fields. Such a device can be further optimized to emit circularly polarized radiation with specific chirality and to realize the tunability for operating wavelength. Therefore, we show that 2D orthorhombic ferrovalley materials are the promising candidates to provide an advantageous platform to realize the polarizer driven by electric means, which is of great importance in extending the practical applications of valleytronics.

  1. Orbital preservation in a maxillectomy

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Katsuhiko; Nishikawa, Hitomi; Kumagai, Masahiko; Dosaka, Yoshihiro; Kuroda, Toru; Atago, Yoshihiro; Nishio, Masamichi [Sapporo National Hospital (Japan)

    1999-07-01

    In the past 9 years, 38 patients of the maxillary cancer were treated by a combination of radiation and surgery. Sixteen patients showed the orbital involvement as confirmed by a CT scan and/or MRI. An orbital excenteration was necessary in 6 patients, due mainly to deep intraorbital invasion, while in 10, the orbital contents were preserved despite the involvement of the orbital capsule. The local rate of the orbital region in the latter patients evaluated at 48 months after the initial surgery was 44%. For the treatment of the recurrence at the orbital capsule. The application of gold grain (Au{sup 198}) thus appeared to be a useful tool for further preserving the eye. (author)

  2. Orbital preservation in a maxillectomy

    International Nuclear Information System (INIS)

    Tanaka, Katsuhiko; Nishikawa, Hitomi; Kumagai, Masahiko; Dosaka, Yoshihiro; Kuroda, Toru; Atago, Yoshihiro; Nishio, Masamichi

    1999-01-01

    In the past 9 years, 38 patients of the maxillary cancer were treated by a combination of radiation and surgery. Sixteen patients showed the orbital involvement as confirmed by a CT scan and/or MRI. An orbital excenteration was necessary in 6 patients, due mainly to deep intraorbital invasion, while in 10, the orbital contents were preserved despite the involvement of the orbital capsule. The local rate of the orbital region in the latter patients evaluated at 48 months after the initial surgery was 44%. For the treatment of the recurrence at the orbital capsule. The application of gold grain (Au 198 ) thus appeared to be a useful tool for further preserving the eye. (author)

  3. Current-induced spin polarization in InGaAs and GaAs epilayers with varying doping densities

    Science.gov (United States)

    Luengo-Kovac, M.; Huang, S.; Del Gaudio, D.; Occena, J.; Goldman, R. S.; Raimondi, R.; Sih, V.

    2017-11-01

    The current-induced spin polarization and momentum-dependent spin-orbit field were measured in InxGa1 -xAs epilayers with varying indium concentrations and silicon doping densities. Samples with higher indium concentrations and carrier concentrations and lower mobilities were found to have larger electrical spin generation efficiencies. Furthermore, current-induced spin polarization was detected in GaAs epilayers despite the absence of measurable spin-orbit fields, indicating that the extrinsic contributions to the spin-polarization mechanism must be considered. Theoretical calculations based on a model that includes extrinsic contributions to the spin dephasing and the spin Hall effect, in addition to the intrinsic Rashba and Dresselhaus spin-orbit coupling, are found to reproduce the experimental finding that the crystal direction with the smaller net spin-orbit field has larger electrical spin generation efficiency and are used to predict how sample parameters affect the magnitude of the current-induced spin polarization.

  4. Polarized atomic beams for targets

    International Nuclear Information System (INIS)

    Grueebler, W.

    1984-01-01

    The basic principle of the production of polarized atomic hydrogen and deuterium beams are reviewed. The status of the present available polarization, density and intensity are presented. The improvement of atomic beam density by cooling the hydrogen atoms to low velocity is discussed. The possible use of polarized atomic beams as targets in storage rings is shown. It is proposed that polarized atomic beams can be used to produce polarized gas targets with high polarization and greatly improved density

  5. Objectives of a prospective Ukrainian orbiter mission to the moon

    Science.gov (United States)

    Shkuratov, Yu. G.; Lytvynenko, L. M.; Shulga, V. M.; Yatskiv, Ya. S.; Vidmachenko, A. P.; Kislyulk, V. S.

    2003-06-01

    Ukraine has launch vehicles that are able to deliver about 300 kg to lunar orbit. A future Ukrainian lunar program may propose a polar orbiter. This orbiter should fill principal information gaps in our knowledge about the Moon after the Clementine and Lunar Prospector missions and future missions like Smart-1, Lunar-A, and Selene. We consider that this can be provided by radar studies of the Moon with supporting optical photopolarimetric observations from lunar polar orbit. These experiments allow one to better understand global structure of the lunar surface at a wide range of scales, from microns to kilometers. We propose three instruments for the prospective lunar orbiter. They are a synthetic aperture imaging radar, ground-penetrating radar, and imaging UV-spectropolarimeter. The main purpose of the synthetic aperture imaging radar experiment is to study with high-resolution (50 m) permanently shadowed sites in the lunar polar regions. These sites are cold traps for volatiles, and have a potential for resource utilization. Possible presence of water ice in the regolith in the sites makes them interesting for long-term manned bases on the Moon. Radar and optical imaging and mapping of other interesting regions could be also planned. Multi-frequency, multi-polarization sounding of the lunar surface with ground-penetrating radar can provide data about internal structure of the lunar surface from meters to several hundred meters deep. The ground-penetrating radar can be used for measuring megaregolith properties, detection of cryptomaria, and studies of internal structure of the largest craters. Modest spatial resolution (50 m) of the imaging UV-spectropolarimeter should provide total coverage (or coverage of a large portion) of the lunar surface in oblique viewing at large phase angles. Polarization degree at large (>90°) phase angles bears information about characteristic size of the regolith particles. Additional experiments could use the synthetic aperture

  6. GUIDE FOR POLARIZED NEUTRONS

    Science.gov (United States)

    Sailor, V.L.; Aichroth, R.W.

    1962-12-01

    The plane of polarization of a beam of polarized neutrons is changed by this invention, and the plane can be flipped back and forth quicitly in two directions in a trouble-free manner. The invention comprises a guide having a plurality of oppositely directed magnets forming a gap for the neutron beam and the gaps are spaced longitudinally in a spiral along the beam at small stepped angles. When it is desired to flip the plane of polarization the magnets are suitably rotated to change the direction of the spiral of the gaps. (AEC)

  7. Heidelberg polarized alkali source

    International Nuclear Information System (INIS)

    Kraemer, D.; Steffens, E.; Jaensch, H.; Philipps Universitaet, Marburg, Germany)

    1984-01-01

    A new atomic beam type polarized alkali ion source has been installed at Heidelberg. In order to improve the beam polarization considerably optical pumping is applied in combination with an adiabatic medium field transition which results in beams in single hyperfine sublevels. The m state population is determined by laser-induced fluorescence spectroscopy. Highly polarized beams (P/sub s/ > 0.9, s = z, zz) with intensities of 30 to 130 μA can be extracted for Li + and Na + , respectively

  8. Exploratory orbit analysis

    International Nuclear Information System (INIS)

    Michelotti, L.

    1989-03-01

    Unlike the other documents in these proceedings, this paper is neither a scientific nor a technical report. It is, rather, a short personal essay which attempts to describe an Exploratory Orbit Analysis (EOA) environment. Analyzing the behavior of a four or six dimensional nonlinear dynamical system is at least as difficult as analyzing events in high-energy collisions; the consequences of doing it badly, or slowly, would be at least as devastating; and yet the level of effort and expenditure invested in the latter, the very attention paid to it by physicists at large, must be two orders of magnitude greater than that given to the former. It is difficult to choose the model which best explains the behavior of a physical device if one does not first understand the behavior of the available models. The time is ripe for the development of a functioning EOA environment, which I will try to describe in this paper to help us achieve this goal

  9. Orbiting radiation stars

    International Nuclear Information System (INIS)

    Foster, Dean P; Langford, John; Perez-Giz, Gabe

    2016-01-01

    We study a spherically symmetric solution to the Einstein equations in which the source, which we call an orbiting radiation star (OR-star), is a compact object consisting of freely falling null particles. The solution avoids quantum scale regimes and hence neither relies upon nor ignores the interaction of quantum mechanics and gravitation. The OR-star spacetime exhibits a deep gravitational well yet remains singularity free. In fact, it is geometrically flat in the vicinity of the origin, with the flat region being of any desirable scale. The solution is observationally distinct from a black hole because a photon from infinity aimed at an OR-star escapes to infinity with a time delay. (paper)

  10. Exploratory orbit analysis

    Energy Technology Data Exchange (ETDEWEB)

    Michelotti, L.

    1989-03-01

    Unlike the other documents in these proceedings, this paper is neither a scientific nor a technical report. It is, rather, a short personal essay which attempts to describe an Exploratory Orbit Analysis (EOA) environment. Analyzing the behavior of a four or six dimensional nonlinear dynamical system is at least as difficult as analyzing events in high-energy collisions; the consequences of doing it badly, or slowly, would be at least as devastating; and yet the level of effort and expenditure invested in the latter, the very attention paid to it by physicists at large, must be two orders of magnitude greater than that given to the former. It is difficult to choose the model which best explains the behavior of a physical device if one does not first understand the behavior of the available models. The time is ripe for the development of a functioning EOA environment, which I will try to describe in this paper to help us achieve this goal.

  11. Orbital Eccrine Hidrocystoma

    Directory of Open Access Journals (Sweden)

    Deniz Marangoz

    2016-10-01

    Full Text Available A 29-year-old female patient presented with a painless mass on her upper eyelid medially. She noticed the mass 4 years earlier and it had increased in size over time. She had no diplopia, eyelid swelling, skin lesion overlying the mass, or visual disturbances. On ocular examination, eye movements and funduscopy were normal. The mass was movable and painless with palpation. Magnetic resonance imaging with contrast showed a 12x8x7 mm well-circumscribed cystic lesion with no contrast dye appearance. Surgical removal was performed delicately and no capsular rupture occured. Pathological examination revealed an eccrine hidrocystoma. Our aim is to underline that eccrine hidrocystoma should be included in differential diagnosis of orbital masses.

  12. Solitonic natural orbitals

    Science.gov (United States)

    Cioslowski, Jerzy

    2018-04-01

    The dependence of the natural amplitudes of the harmonium atom in its ground state on the confinement strength ω is thoroughly investigated. A combination of rigorous analysis and extensive, highly accurate numerical calculations reveals the presence of only one positive-valued natural amplitude ("the normal sign pattern") for all ω ≥1/2 . More importantly, it is shown that unusual, weakly occupied natural orbitals (NOs) corresponding to additional positive-valued natural amplitudes emerge upon sufficient weakening of the confinement. These solitonic NOs, whose shapes remain almost invariant as their radial positions drift toward infinity upon the critical values of ω being approached from below, exhibit strong radial localization. Their asymptotic properties are extracted from the numerical data and their relevance to calculations on fully Coulombic systems is discussed.

  13. The representation of neutron polarization

    International Nuclear Information System (INIS)

    Byrne, J.

    1979-01-01

    Neutron beam polarization representation is discussed under the headings; transfer matrices, coherent parity violation for neutrons, neutron spin rotation in helical magnetic fields, polarization and interference. (UK)

  14. Stellar orbits around Sgr A*

    International Nuclear Information System (INIS)

    Trippe, S; Gillessen, S; Ott, T; Eisenhauer, F; Paumard, T; Martins, F; Genzel, R; Schoedel, R; Eckart, A; Alexander, T

    2006-01-01

    In this article we present and discuss the latest results from the observations of stars (''S-stars'') orbiting Sgr A* . With improving data quality the number of observed S-stars has increased substantially in the last years. The combination of radial velocity and proper motion information allows an ever more precise determination of orbital parameters and of the mass of and the distance to the supermassive black hole in the centre of the Milky Way. Additionally, the orbital solutions allow us to verify an agreement between the NIR source Sgr A* and the dynamical centre of the stellar orbits to within 2 mas

  15. Accelerated testing for synchronous orbits

    Science.gov (United States)

    Mcdermott, P.

    1981-01-01

    Degradation of batteries during synchronous orbits is analyzed. Discharge and recharge rates are evaluated. The functional relationship between charge rate and degradation is mathematically determined.

  16. The conservation of orbital symmetry

    CERN Document Server

    Woodward, R B

    2013-01-01

    The Conservation of Orbital Symmetry examines the principle of conservation of orbital symmetry and its use. The central content of the principle was that reactions occur readily when there is congruence between orbital symmetry characteristics of reactants and products, and only with difficulty when that congruence does not obtain-or to put it more succinctly, orbital symmetry is conserved in concerted reaction. This principle is expected to endure, whatever the language in which it may be couched, or whatever greater precision may be developed in its application and extension. The book ope

  17. Direct measurement of discrete valley and orbital quantum numbers in bilayer graphene.

    Science.gov (United States)

    Hunt, B M; Li, J I A; Zibrov, A A; Wang, L; Taniguchi, T; Watanabe, K; Hone, J; Dean, C R; Zaletel, M; Ashoori, R C; Young, A F

    2017-10-16

    The high magnetic field electronic structure of bilayer graphene is enhanced by the spin, valley isospin, and an accidental orbital degeneracy, leading to a complex phase diagram of broken symmetry states. Here, we present a technique for measuring the layer-resolved charge density, from which we directly determine the valley and orbital polarization within the zero energy Landau level. Layer polarization evolves in discrete steps across 32 electric field-tuned phase transitions between states of different valley, spin, and orbital order, including previously unobserved orbitally polarized states stabilized by skew interlayer hopping. We fit our data to a model that captures both single-particle and interaction-induced anisotropies, providing a complete picture of this correlated electron system. The resulting roadmap to symmetry breaking paves the way for deterministic engineering of fractional quantum Hall states, while our layer-resolved technique is readily extendable to other two-dimensional materials where layer polarization maps to the valley or spin quantum numbers.The phase diagram of bilayer graphene at high magnetic fields has been an outstanding question, with orders possibly between multiple internal quantum degrees of freedom. Here, Hunt et al. report the measurement of the valley and orbital order, allowing them to directly reconstruct the phase diagram.

  18. A plasma solenoid driven by an Orbital Angular Momentum laser beam

    OpenAIRE

    Nuter, R.; Korneev, Ph.; Thiele, I.; Tikhonchuk, V.

    2018-01-01

    A tens of Tesla quasi-static axial magnetic field can be produced in the interaction of a short intense laser beam carrying an Orbital Angular Momentum with an underdense plasma. Three-dimensional "Particle In Cell" simulations and analytical model demonstrate that orbital angular momentum is transfered from a tightly focused radially polarized laser beam to electrons without any dissipative effect. A theoretical model describing the balistic interaction of electrons with laser shows that par...

  19. The role of Rashba spin-orbit coupling in valley-dependent transport of Dirac fermions

    Energy Technology Data Exchange (ETDEWEB)

    Hasanirok, Kobra; Mohammadpour, Hakimeh

    2017-01-01

    At this work, spin- and valley-dependent electron transport through graphene and silicene layers are studied in the presence of Rashba spin- orbit coupling. We find that the transport properties of the related ferromagnetic/normal/ferromagnetic structure depend on the relevant parameters. A fully valley- and spin- polarized current is obtained. As another result, Rashba spin-orbit interaction plays important role in controlling the transmission characteristics.

  20. A model of quasi-free scattering with polarized protons

    International Nuclear Information System (INIS)

    Teodoro, M.R.

    1976-01-01

    A quantitative evaluation, based on a simple model for spin-free coplanar and asymmetric reaction in 16 O, for 215 MeV incoming polarized protons confirms the use of the strong effective polarization of the knocked-out proton by the spin-orbit coupling and of the strong dependence of free, medium energy, proton-proton cross section on the relative orientation of the proton spins. Effective polarizations, momentum distributions and correlation cross sections have been calculated for the 1p sub(1/2), 1 p sub(3/2) and 1s sub(1/2) states in 16 O, using protons totally polarized orthogonal to the scattering plane. Harmonic oscillator and square wells have been used to generate the bound state wave functions, whereas the optical potentials have been taken spin-independent and purely imaginary [pt

  1. Electron spin polarization in high-energy storage rings

    International Nuclear Information System (INIS)

    Mane, S.R.

    1987-01-01

    In a high energy storage ring, a single photon emission has relatively little effect on the orbital motion, but it can produce a relatively large change in the electron spin state. Hence the unperturbed orbital motion can be satisfactorily described using classical mechanics, but the spin must be treated quantum mechanically. The electron motion is therefore treated semi-classically in this thesis. It is explained how to diagonalize the unperturbed Hamiltonian to the leading order in Planck's constant. The effects of perturbations are then included, and the relevant time-scales and ensemble averages are elucidated. The Derbenev-Kondratenko formula for the equilibrium degree of polarization is rederived. Mathematical details of the rederivation are given. Since the original authors used a different formalism, a proof is offered of the equivalence between their method and the one used in this thesis. An algorithm is also presented to evaluate the equilibrium polarization. It has a number of new features, which enable the polarization to be calculated to a higher degree of approximation than has hitherto been possible. This facilitates the calculation of so-called spin resonances, which are points at which the polarization almost vanishes. A computer program has been written to implement the above algorithm, in the approximation of linear orbital dynamics, and sample results are presented

  2. Electrically tunable spin polarization in silicene: A multi-terminal spin density matrix approach

    International Nuclear Information System (INIS)

    Chen, Son-Hsien

    2016-01-01

    Recent realized silicene field-effect transistor yields promising electronic applications. Using a multi-terminal spin density matrix approach, this paper presents an analysis of the spin polarizations in a silicene structure of the spin field-effect transistor by considering the intertwined intrinsic and Rashba spin–orbit couplings, gate voltage, Zeeman splitting, as well as disorder. Coexistence of the stagger potential and intrinsic spin–orbit coupling results in spin precession, making any in-plane polarization directions reachable by the gate voltage; specifically, the intrinsic coupling allows one to electrically adjust the in-plane components of the polarizations, while the Rashba coupling to adjust the out-of-plan polarizations. Larger electrically tunable ranges of in-plan polarizations are found in oppositely gated silicene than in the uniformly gated silicene. Polarizations in different phases behave distinguishably in weak disorder regime, while independent of the phases, stronger disorder leads to a saturation value. - Highlights: • Density matrix with spin rotations enables multi-terminal arbitrary spin injections. • Gate-voltage tunable in-plane polarizations require intrinsic SO coupling. • Gate-voltage tunable out-of-plane polarizations require Rashba SO coupling. • Oppositely gated silicene yields a large tunable range of in-plan polarizations. • Polarizations in different phases behave distinguishably only in weak disorder.

  3. Spin Interference in Rectangle Loop Based on Rashba and Dresselhaus Spin-Orbit Interactions

    International Nuclear Information System (INIS)

    Jia-Ting, Ni; Bin, Chen; Xiao-Wan, Liang; Koga, T.

    2009-01-01

    We demonstrate the amplitude and spin polarization of AAS oscillation changing with Rashba spin-orbit interaction (SOI) and Dresselhaus SOI. The amplitude and spin polarization of AB oscillation changing with Rashba SOI and Dresselhaus SOI are demonstrated as well. The ideal quasi-one-dimensional square loop does not exist in reality, therefore to match the experiment better we should consider the shape of the rectangle loop in theory

  4. Project Freebird: An orbital transfer vehicle

    Science.gov (United States)

    Aneses, Carlos A.; Blanchette, Ryan L.; Brann, David M.; Campos, Mario J.; Cohen, Lisa E.; Corcoran, Daniel J., III; Cox, James F.; Curtis, Trevor J.; Douglass, Deborah A.; Downard, Catherine L.

    1994-08-01

    Freebird is a space-based orbital transfer vehicle designed to repair and deorbit orbital assets. Freebird is based at International Space Station Alpha (ISSA) at an inclination of 51.6 deg and is capable of three types of missions: crewed and teleoperated LEO missions, and extended robotic missions. In a crewed local configuration, the vehicle can visit inclinations between 30.8 deg and 72.4 deg at altitudes close to 390 km. Adding extra fuel tanks extends this range of inclination up to 84.9 deg and down to 18.3 deg. Furthermore, removing the crew module, using the vehicle in a teleoperated manner, and operating with extra fuel tanks allows missions to polar and geosynchronous orbits. To allow for mission flexibility, the vehicle was designed in a semimodular configuration. The major system components include a crew module, a 'smart box' (which contains command, communications, guidance, and navigation equipment), a propulsion pack, extra fuel tanks, and a vehicle storage facility (VSF) for storage purposes. To minimize risk as well as development time and cost, the vehicle was designed using only proven technology or technology which is expected to be flight-qualified in time for the intended launch date of 2002. And, because Freebird carries crew and operates near the space station, it must meet or exceed the NASA reliability standard of 0.994, as well as other standard requirements for such vehicles. The Freebird program was conceived and designed as a way to provide important and currently unavailable satellite repair and replacement services of a value equal to or exceeding operational costs.

  5. Interferometric polarization control

    International Nuclear Information System (INIS)

    Chuss, David T.; Wollack, Edward J.; Moseley, S. Harvey; Novak, Giles

    2006-01-01

    We develop the Jones and Mueller matrices for structures that allow control of the path length difference between two linear orthogonal polarizations and consider the effect of placing multiple devices in series. Specifically, we find that full polarization modulation (measurement of Stokes Q, U, and V) can be achieved by placing two such modulators in series if the relative angles of the beam-splitting grids with respect to the analyzer orientation are appropriately chosen. Such a device has several potential advantages over a spinning wave plate modulator for measuring astronomical polarization in the far infrared through millimeter: (i) The use of small, linear motions eliminates the need for cryogenic rotational bearings; (ii) the phase flexibility allows measurement of circular as well as linear polarization; and (iii) this architecture allows for both multiwavelength and broadband modulation. We also present initial laboratory results

  6. Dynamic nuclear spin polarization

    Energy Technology Data Exchange (ETDEWEB)

    Stuhrmann, H B [GKSS-Forschungszentrum Geesthacht GmbH (Germany)

    1996-11-01

    Polarized neutron scattering from dynamic polarized targets has been applied to various hydrogenous materials at different laboratories. In situ structures of macromolecular components have been determined by nuclear spin contrast variation with an unprecedented precision. The experiments of selective nuclear spin depolarisation not only opened a new dimension to structural studies but also revealed phenomena related to propagation of nuclear spin polarization and the interplay of nuclear polarisation with the electronic spin system. The observation of electron spin label dependent nuclear spin polarisation domains by NMR and polarized neutron scattering opens a way to generalize the method of nuclear spin contrast variation and most importantly it avoids precontrasting by specific deuteration. It also likely might tell us more about the mechanism of dynamic nuclear spin polarisation. (author) 4 figs., refs.

  7. Polarized proton colliders

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    High energy polarized beam collisions will open up the unique physics opportunities of studying spin effects in hard processes. This will allow the study of the spin structure of the proton and also the verification of the many well documented expectations of spin effects in perturbative QCD and parity violation in W and Z production. Proposals for polarized proton acceleration for several high energy colliders have been developed. A partial Siberian Snake in the AGS has recently been successfully tested and full Siberian Snakes, spin rotators, and polarimeters for RHIC are being developed to make the acceleration of polarized beams to 250 GeV possible. This allows for the unique possibility of colliding two 250 GeV polarized proton beams at luminosities of up to 2 x 10 32 cm -2 s -1

  8. The CERN Neutrino Platform

    CERN Document Server

    Bordoni, Stefania

    2018-01-01

    The long-baseline neutrino programme has been classified as one of the four highest-priority sci- entific objectives in 2013 by the European Strategy for Particle Physics. The Neutrino Platform is the CERN venture to foster and support the next generation of accelerator-based neutrino os- cillation experiments. Part of the present CERN Medium-Term Plan, the Neutrino Platform provide facilities to develop and prototype the next generation of neutrino detectors and contribute to unify the European neu- trino community towards the US and Japanese projects. A significative effort is made on R&D; for LAr TPC technologies: two big LAr TPC prototypes for the DUNE far detector are under con- struction at CERN. Those detectors will be exposed in 2018 to an entirely new and NP-dedicated beam-line from the SPS which will provide electron, muon and hadron beams with energies in the range of sub-GeV to a few GeV. Other projects are also presently under development: one can cite the refurbishing and shipping to the US ...

  9. Generation of radio vortex beams with designable polarization using anisotropic frequency selective surface

    Science.gov (United States)

    Yang, Jin; Zhang, Cheng; Ma, Hui Feng; Zhao, Jie; Dai, Jun Yan; Yuan, Wei; Yang, Liu Xi; Cheng, Qiang; Cui, Tie Jun

    2018-05-01

    We propose a strategy to convert a linearly polarized wave from a single point source to an orbital angular momentum (OAM) wave by arbitrary polarization via an anisotropic frequency selective surface (FSS) in the microwave frequency. By tailoring the geometries of FSS elements, reflection-phases in x and y polarizations are engineered and encoded independently, which allows us to design the eventual polarization state of the generated OAM vortex beam by elaborately selecting individual coding sequences for each polarization. Two types of FSSs are designed and experimentally characterized to demonstrate the capability of OAM generation with circular and linear polarizations, respectively, showing excellent performance in a wide bandwidth from 14 to 16 GHz. This method provides opportunities for polarization multiplexing in microwave OAM communication systems.

  10. PyORBIT: A Python Shell For ORBIT

    Energy Technology Data Exchange (ETDEWEB)

    Jean-Francois Ostiguy; Jeffrey Holmes

    2003-07-01

    ORBIT is code developed at SNS to simulate beam dynamics in accumulation rings and synchrotrons. The code is structured as a collection of external C++ modules for SuperCode, a high level interpreter shell developed at LLNL in the early 1990s. SuperCode is no longer actively supported and there has for some time been interest in replacing it by a modern scripting language, while preserving the feel of the original ORBIT program. In this paper, we describe a new version of ORBIT where the role of SuperCode is assumed by Python, a free, well-documented and widely supported object-oriented scripting language. We also compare PyORBIT to ORBIT from the standpoint of features, performance and future expandability.

  11. Orbital Chondroma: A rare mesenchymal tumor of orbit

    Directory of Open Access Journals (Sweden)

    Ruchi S Kabra

    2015-01-01

    Full Text Available While relatively common in the skeletal system, cartilaginous tumors are rarely seen originating from the orbit. Here, we report a rare case of an orbital chondroma. A 27-year-old male patient presented with a painless hard mass in the superonasal quadrant (SNQ of left orbit since 3 months. On examination, best-corrected visual acuity of both eyes was 20/20, with normal anterior and posterior segment with full movements of eyeballs and normal intraocular pressure. Computerized tomography scan revealed well defined soft tissue density lesion in SNQ of left orbit. Patient was operated for anteromedial orbitotomy under general anesthesia. Mass was excised intact and sent for histopathological examination (HPE. HPE report showed lobular aggregates of benign cartilaginous cells with mild atypia suggesting of benign cartilaginous tumor - chondroma. Very few cases of orbital chondroma have been reported in literature so far.

  12. PyORBIT: A Python Shell For ORBIT

    International Nuclear Information System (INIS)

    Jean-Francois Ostiguy; Jeffrey Holmes

    2003-01-01

    ORBIT is code developed at SNS to simulate beam dynamics in accumulation rings and synchrotrons. The code is structured as a collection of external C++ modules for SuperCode, a high level interpreter shell developed at LLNL in the early 1990s. SuperCode is no longer actively supported and there has for some time been interest in replacing it by a modern scripting language, while preserving the feel of the original ORBIT program. In this paper, we describe a new version of ORBIT where the role of SuperCode is assumed by Python, a free, well-documented and widely supported object-oriented scripting language. We also compare PyORBIT to ORBIT from the standpoint of features, performance and future expandability

  13. Plasma polarization spectroscopy

    International Nuclear Information System (INIS)

    Iwamae, Atsushi; Horimoto, Yasuhiro; Fujimoto, Takashi; Hasegawa, Noboru; Sukegawa, Kouta; Kawachi, Tetsuya

    2005-01-01

    The electron velocity distribution function (EVDF) in plasma can be anisotropic in laser-produced plasmas. We have developed a new technique to evaluate the polarization degree of the emission lines in the extreme vacuum ultra violet wavelength region. The polarization of the emission lines and the continuums from the lithium-like nitrogen and from helium- and hydrogen-like carbon in recombining plasma is evaluated. Particle simulation in the velocity space gives the time scale for relaxation of anisotropic EVDFs. (author)

  14. No More Polarization, Please!

    OpenAIRE

    Reinholt, Mia

    2006-01-01

    The organizational science literature on motivation has for long been polarized into two main positions; the organizational economic position focusing on extrinsic motivation and the organizational behavior position emphasizing intrinsic motivation. With the rise of the knowledge economy and the increasing levels of complexities it entails, such polarization is not fruitful in the attempt to explain motivation of organizational members. This paper claims that a more nuanced perspective on mot...

  15. Inertial polarization of dielectrics

    OpenAIRE

    Zavodovsky, A. G.

    2011-01-01

    It was proved that accelerated motion of a linear dielectric causes its polarization. Accelerated translational motion of a dielectric's plate leads to the positive charge of the surface facing the direction of motion. Metal plates of a capacitor were used to register polarized charges on a dielectric's surface. Potential difference between the capacitor plates is proportional to acceleration, when acceleration is constant potential difference grows with the increase of a dielectric's area, o...

  16. The Polarization of Achernar

    Science.gov (United States)

    McDavid, D.

    2005-11-01

    Recent near-infrared measurements of the angular diameter of Achernar (the bright Be star alpha Eridani) with the ESO VLT interferometer have been interpreted as the detection of an extremely oblate photosphere, with a ratio of equatorial to polar radius of at least 1.56 ± 0.05 and a minor axis orientation of 39° ± 1° (from North to East). The optical linear polarization of this star during an emission phase in 1995 September was 0.12 ± 0.02% at position angle 37° ± 8° (in equatorial coordinates), which is the direction of the projection of the rotation axis on the plane of the sky according to the theory of polarization by electron scattering in an equatorially flattened circumstellar disk. These two independent determinations of the orientation of the rotation axis are therefore in agreement. The observational history of correlations between Hα emission and polarization as found in the literature is that of a typical Be star, with the exception of an interesting question raised by the contrast between Schröder's measurement of a small polarization perpendicular to the projected rotation axis in 1969--70 and Tinbergen's measurement of zero polarization in 1974.5, both at times when emission was reportedly absent.

  17. Fusion of a polarized projectile with a polarized target

    International Nuclear Information System (INIS)

    Christley, J.A.; Johnson, R.C.; Thompson, I.J.

    1995-01-01

    The fusion cross sections for a polarized target with both unpolarized and polarized projectiles are studied. Expressions for the observables are given for the case when both nuclei are polarized. Calculations for fusion of an aligned 165 Ho target with 16 O and polarized 7 Li beams are presented

  18. Analysis of CMOS Compatible Cu-Based TM-Pass Optical Polarizer

    KAUST Repository

    Ng, Tien Khee

    2012-02-10

    A transverse-magnetic-pass (TM-pass) optical polarizer based on Cu complementary metal-oxide-semiconductor technology platform is proposed and analyzed using the 2-D method-of-lines numerical model. In designing the optimum configuration for the polarizer, it was found that the metal-insulator-metal (MIM) polarizer structure is superior compared to the insulator-metal-insulator polarizer structure due to its higher polarization extinction ratio (PER) and low insertion loss. An optimized MIM TM-pass polarizer exhibits simulated long wavelength pass filter characteristics of > ?1.2 ?m, with fundamental TM 0 and TE 0 mode transmissivity of >70% and <5%, respectively, and with PER ?11.5 dB in the wavelength range of 1.2-1.6 ?m. The subwavelength and submicrometer features of this TM-polarizer are potentially suitable for compact and low power photonics integrated circuit implementation on silicon-based substrates. © 1989-2012 IEEE.

  19. Prospects for polarization at RHIC and SSC

    International Nuclear Information System (INIS)

    Lee, S.Y.

    1991-01-01

    In low to medium energy accelerators, betatron tune jumps and vertical orbit harmonic correction methods have been used to overcome the intrinsic and imperfection resonances. At high energy accelerators, snakes are needed to preserve polarization. We analyze the effects of snake resonances, snake imperfections overlapping resonances on the spin depolarization. We discuss also results of recent snake experiments at the IUCF Cooler Ring. The snake can overcome various kinds of spin depolarization resonances. These experiments pointed out further that partial snake can be used to cure the imperfection resonances in low to medium energy accelerators. We also examine various snake designs. A new generalized snake concept allows for two possible configurations. The compact configuration offers the advantages of shorter total snake length and smaller horizontal orbit displacement. The split snake configuration allows for dual functions of a snake and a 90 degree spin rotator at the mid-section of the snake, which provides helicity state collisions. The requirements for obtaining high luminosity polarized protons at high energy colliders, such as RHIC and SSC, are reviewed

  20. Spin Polarization Inversion at Benzene-Absorbed Fe4N Surface

    KAUST Repository

    Zhang, Qian; Mi, Wenbo; Wang, Xiaocha; Wang, Xuhui

    2015-01-01

    We report a first-principle study on electronic structure and simulation of the spin-polarized scanning tunneling microscopy graphic of a benzene/Fe4N interface. Fe4N is a compound ferromagnet suitable for many spintronic applications. We found that, depending on the particular termination schemes and interface configurations, the spin polarization on the benzene surface shows a rich variety of properties ranging from cosine-type oscillation to polarization inversion. Spin-polarization inversion above benzene is resulting from the hybridizations between C pz and the out-of-plane d orbitals of Fe atom.

  1. Spin Polarization Inversion at Benzene-Absorbed Fe4N Surface

    KAUST Repository

    Zhang, Qian

    2015-05-27

    We report a first-principle study on electronic structure and simulation of the spin-polarized scanning tunneling microscopy graphic of a benzene/Fe4N interface. Fe4N is a compound ferromagnet suitable for many spintronic applications. We found that, depending on the particular termination schemes and interface configurations, the spin polarization on the benzene surface shows a rich variety of properties ranging from cosine-type oscillation to polarization inversion. Spin-polarization inversion above benzene is resulting from the hybridizations between C pz and the out-of-plane d orbitals of Fe atom.

  2. Infected orbital cyst following exenteration.

    Science.gov (United States)

    Barak, A; Hirsh, A; Rosner, M; Rosen, N

    1996-09-01

    An orbital cyst is a rare complication of orbital trauma and exenteration. Infections of such cysts have not been described, and are potentially dangerous unless treated immediately. The authors describe a case of delayed treatment of such an infected cyst, which resolved following surgical drainage. The potentially hazardous outcome makes knowledge of such cases important.

  3. GridOrbit public display

    DEFF Research Database (Denmark)

    Ramos, Juan David Hincapie; Tabard, Aurélien; Bardram, Jakob

    2010-01-01

    We introduce GridOrbit, a public awareness display that visualizes the activity of a community grid used in a biology laboratory. This community grid executes bioin-formatics algorithms and relies on users to donate CPU cycles to the grid. The goal of GridOrbit is to create a shared awareness about...

  4. Diplopia and Orbital Wall Fractures

    NARCIS (Netherlands)

    Boffano, P.; Roccia, F.; Gallesio, C.; Karagozoglu, K.H.; Forouzanfar, T.

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and

  5. Diplopia and orbital wall fractures

    NARCIS (Netherlands)

    Boffano, P.; Roccia, F.; Gallesio, C.; Karagozoglu, K.H.; Forouzanfar, T.

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and

  6. Polarized Light Microscopy

    Science.gov (United States)

    Frandsen, Athela F.

    2016-01-01

    Polarized light microscopy (PLM) is a technique which employs the use of polarizing filters to obtain substantial optical property information about the material which is being observed. This information can be combined with other microscopy techniques to confirm or elucidate the identity of an unknown material, determine whether a particular contaminant is present (as with asbestos analysis), or to provide important information that can be used to refine a manufacturing or chemical process. PLM was the major microscopy technique in use for identification of materials for nearly a century since its introduction in 1834 by William Fox Talbot, as other techniques such as SEM (Scanning Electron Microscopy), FTIR (Fourier Transform Infrared spectroscopy), XPD (X-ray Powder Diffraction), and TEM (Transmission Electron Microscopy) had not yet been developed. Today, it is still the only technique approved by the Environmental Protection Agency (EPA) for asbestos analysis, and is often the technique first applied for identification of unknown materials. PLM uses different configurations in order to determine different material properties. With each configuration additional clues can be gathered, leading to a conclusion of material identity. With no polarizing filter, the microscope can be used just as a stereo optical microscope, and view qualities such as morphology, size, and number of phases. With a single polarizing filter (single polars), additional properties can be established, such as pleochroism, individual refractive indices, and dispersion staining. With two polarizing filters (crossed polars), even more can be deduced: isotropy vs. anisotropy, extinction angle, birefringence/degree of birefringence, sign of elongation, and anomalous polarization colors, among others. With the use of PLM many of these properties can be determined in a matter of seconds, even for those who are not highly trained. McCrone, a leader in the field of polarized light microscopy, often

  7. The Submillimeter Polarization of Sgr A*

    Energy Technology Data Exchange (ETDEWEB)

    Marrone, Daniel P [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Moran, James M [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Zhao, Jun-Hui [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Rao, Ramprasad [Inst. of Ast. and Astrophys., Academia Sinica, PO Box 23-141, Taipei 10617, Taiwan (China)

    2006-12-15

    We report on the submillimeter properties of Sgr A* derived from observations with the Submillimeter Array and its polarimeter. We ftid that the spectrum of Sgr A* between 230 and 690 GHz is slightly decreasing when measured simultaneously, indicating a transition to optically thin emission around 300-400 GHz. We also present very sensitive and well calibrated measurements of the polarization of Sgr A* at 230 and 345 GHz. With these data we are able to show for the frst time that the polarization of Sgr A* varies on hour timescales, as has been observed for the total intensity. On one night we fhd variability that may arise from a polarized 'blob' orbiting the black hole. Finally, we use the ensemble of observations to determine the rotation measure. This represents the frst statistically significant rotation measure determination and the only one made without resorting to comparing position angles measured at separate epochs. We frid a rotation measure of (-5.6 {+-} 0.7) x 10{sup 5} rad m{sup 2}, with no evidence for variability on inter-day timescales at the level of the measurement error. The stability constrains interday flictuations in the accretion rate to 8%. The mean intrinsic polarization position angle is 167{sup 0}{+-}7{sup 0} and we detect variations of 31{sup +18}{sub -9} degrees. This separation of intrinsic polarization changes and possible rotation measure flictuations is now possible because of the frequency coverage and sensitivity of our data. The observable rotation measure restricts the accretion rate to the range 2 x 10{sup -7} M o-dot yr{sup -1} to 2 x 10{sup -9} M o-dot yr{sup -1}, if the magnetic field is near equipartition and ordered.

  8. The Submillimeter Polarization of Sgr A*

    International Nuclear Information System (INIS)

    Marrone, Daniel P; Moran, James M; Zhao, Jun-Hui; Rao, Ramprasad

    2006-01-01

    We report on the submillimeter properties of Sgr A* derived from observations with the Submillimeter Array and its polarimeter. We ftid that the spectrum of Sgr A* between 230 and 690 GHz is slightly decreasing when measured simultaneously, indicating a transition to optically thin emission around 300-400 GHz. We also present very sensitive and well calibrated measurements of the polarization of Sgr A* at 230 and 345 GHz. With these data we are able to show for the frst time that the polarization of Sgr A* varies on hour timescales, as has been observed for the total intensity. On one night we fhd variability that may arise from a polarized 'blob' orbiting the black hole. Finally, we use the ensemble of observations to determine the rotation measure. This represents the frst statistically significant rotation measure determination and the only one made without resorting to comparing position angles measured at separate epochs. We frid a rotation measure of (-5.6 ± 0.7) x 10 5 rad m 2 , with no evidence for variability on inter-day timescales at the level of the measurement error. The stability constrains interday flictuations in the accretion rate to 8%. The mean intrinsic polarization position angle is 167 0 ±7 0 and we detect variations of 31 +18 -9 degrees. This separation of intrinsic polarization changes and possible rotation measure flictuations is now possible because of the frequency coverage and sensitivity of our data. The observable rotation measure restricts the accretion rate to the range 2 x 10 -7 M o-dot yr -1 to 2 x 10 -9 M o-dot yr -1 , if the magnetic field is near equipartition and ordered

  9. The Submillimeter Polarization of Sgr A*

    Science.gov (United States)

    Marrone, Daniel P.; Moran, James M.; Zhao, Jun-Hui; Rao, Ramprasad

    2006-12-01

    We report on the submillimeter properties of Sgr A* derived from observations with the Submillimeter Array and its polarimeter. We ftid that the spectrum of Sgr A* between 230 and 690 GHz is slightly decreasing when measured simultaneously, indicating a transition to optically thin emission around 300 400 GHz. We also present very sensitive and well calibrated measurements of the polarization of Sgr A* at 230 and 345 GHz. With these data we are able to show for the frst time that the polarization of Sgr A* varies on hour timescales, as has been observed for the total intensity. On one night we fhd variability that may arise from a polarized "blob" orbiting the black hole. Finally, we use the ensemble of observations to determine the rotation measure. This represents the frst statistically significant rotation measure determination and the only one made without resorting to comparing position angles measured at separate epochs. We frid a rotation measure of (-5.6 ± 0.7) × 105 rad m2, with no evidence for variability on inter-day timescales at the level of the measurement error. The stability constrains interday flictuations in the accretion rate to 8%. The mean intrinsic polarization position angle is 167°±7° and we detect variations of 31+18-9 degrees. This separation of intrinsic polarization changes and possible rotation measure flictuations is now possible because of the frequency coverage and sensitivity of our data. The observable rotation measure restricts the accretion rate to the range 2 × 10-7 Mdot o yr-1 to 2 × 10-9 Mdot o yr-1, if the magnetic ffeld is near equipartition and ordered.

  10. Earth Orbiting Support Systems for commercial low Earth orbit data relay: Assessing architectures through tradespace exploration

    Science.gov (United States)

    Palermo, Gianluca; Golkar, Alessandro; Gaudenzi, Paolo

    2015-06-01

    As small satellites and Sun Synchronous Earth Observation systems are assuming an increased role in nowadays space activities, including commercial investments, it is of interest to assess how infrastructures could be developed to support the development of such systems and other spacecraft that could benefit from having a data relay service in Low Earth Orbit (LEO), as opposed to traditional Geostationary relays. This paper presents a tradespace exploration study of the architecture of such LEO commercial satellite data relay systems, here defined as Earth Orbiting Support Systems (EOSS). The paper proposes a methodology to formulate architectural decisions for EOSS constellations, and enumerate the corresponding tradespace of feasible architectures. Evaluation metrics are proposed to measure benefits and costs of architectures; lastly, a multicriteria Pareto criterion is used to downselect optimal architectures for subsequent analysis. The methodology is applied to two case studies for a set of 30 and 100 customer-spacecraft respectively, representing potential markets for LEO services in Exploration, Earth Observation, Science, and CubeSats. Pareto analysis shows how increased performance of the constellation is always achieved by an increased node size, as measured by the gain of the communications antenna mounted on EOSS spacecraft. On the other hand, nonlinear trends in optimal orbital altitude, number of satellites per plane, and number of orbital planes, are found in both cases. An upward trend in individual node memory capacity is found, although never exceeding 256 Gbits of onboard memory for both cases that have been considered, assuming the availability of a polar ground station for EOSS data downlink. System architects can use the proposed methodology to identify optimal EOSS constellations for a given service pricing strategy and customer target, thus identifying alternatives for selection by decision makers.

  11. When measured spin polarization is not spin polarization

    International Nuclear Information System (INIS)

    Dowben, P A; Wu Ning; Binek, Christian

    2011-01-01

    Spin polarization is an unusually ambiguous scientific idiom and, as such, is rarely well defined. A given experimental methodology may allow one to quantify a spin polarization but only in its particular context. As one might expect, these ambiguities sometimes give rise to inappropriate interpretations when comparing the spin polarizations determined through different methods. The spin polarization of CrO 2 and Cr 2 O 3 illustrate some of the complications which hinders comparisons of spin polarization values. (viewpoint)

  12. Evidence for a new geomagnetic reversal from lava flows in Idaho: discussion of short polarity reversals in the Brunhes and late Matuyama Polarity Chrons

    Science.gov (United States)

    Champion, D.E.; Lanphere, M.A.; Kuntz, M.A.

    1988-01-01

    K-Ar ages and paleomagnetic data for basalt samples from a new core hole (site E) at the Idaho National Engineering Laboratory (INEL) indicate that the age of the reversed polarity event recorded in Snake River Plain lavas is older than 465 ?? 50 ka (1000 years before present) reported previously by Champion et al. (1981). A review of data documenting short reversal records from volcanic and sedimentary rocks shows that there is evidence for eight polarity subchrons in the Brunhes and two besides the Jaramillo in the late Matuyama. These 10 short subchrons begin to indicate the many short events that Cox (1968) hypothesized must exist if polarity interval lengths have a Poisson distribution. The mean sustained polarity interval length since late Matuyama Chron time is 90 000 years. The similarity of this number with the 105-year period of the Earth's orbital eccentricity suggests anew that linkage between geomagnetic, paleoclimatic, and possible underlying Earth orbital parameters should be evaluated. -from Authors

  13. Preparing for a Product Platform

    DEFF Research Database (Denmark)

    Fiil-Nielsen, Ole; Munk, Lone; Mortensen, Niels Henrik

    2005-01-01

    on commonalities and similarities in the product family, and variance should be based on customer demands. To relate these terms and to improve the basis on which decisions are made, we need a way of visualizing the hierarchy of the product family as well as the commonality and variance. This visualization method...... of the platform or ensuring that the platform can meet future demands will be very useful in the preparation process of a platform synthesis as well as in the updating or reengineering of an existing product development platform.......Experience in the industry as well as recent related scientific publications show the benefits of product development platforms. Companies use platforms to develop not a single but multiple products (i.e. a product family) simultaneously. When these product development projects are coordinated...

  14. Adoption of Mobile Payment Platforms

    DEFF Research Database (Denmark)

    Staykova, Kalina Stefanova; Damsgaard, Jan

    2016-01-01

    Numerous mobile payment solutions, which rely on new disruptive technologies, have been launched on the payment market in recent years. But despite the growing number of mobile payment apps, very few solutions have turned to be successful as the majority of them fail to gain a critical mass...... of users. In this paper, we investigate successful platform adoption strategies by using the Reach and Range Framework for Multi-Sided Platforms as a strategic tool to which mobile payment providers can adhere in order to tackle some of the main challenges they face throughout the evolution...... of their platforms. The analysis indicates that successful mobile payment solutions tend to be launched as one-sided platforms and then gradually be expanded into being two-sided. Our study showcases that the success of mobile payment platforms lies with the ability of the platform to balance the reach (number...

  15. Web Platform Application

    Energy Technology Data Exchange (ETDEWEB)

    Paulsworth, Ashley [Sunvestment Group, Frederick, MD (United States); Kurtz, Jim [Sunvestment Group, Frederick, MD (United States); Brun de Pontet, Stephanie [Sunvestment Group, Frederick, MD (United States)

    2016-06-15

    Sunvestment Energy Group (previously called Sunvestment Group) was established to create a web application that brings together site hosts, those who will obtain the energy from the solar array, with project developers and funders, including affinity investors. Sunvestment Energy Group (SEG) uses a community-based model that engages with investors who have some affinity with the site host organization. In addition to a financial return, these investors receive non-financial value from their investments and are therefore willing to offer lower cost capital. This enables the site host to enjoy more savings from solar through these less expensive Community Power Purchase Agreements (CPPAs). The purpose of this award was to develop an online platform to bring site hosts and investors together virtually.

  16. Mobile4D platform

    CSIR Research Space (South Africa)

    Botha, Adèle

    2010-05-01

    Full Text Available and share their own Internet/Telco service Mashups. digm. This all 2.1.2  SPICE   Service Platform for Innovative Communication Environment was also a European Union’s Sixth Framework Programme (FP6) funded project, which formed a consortium consisting...  OPUCE  SPICE  Twisted   Mobicents  Telco  specific  Minimal Total Life cycle cost  ?  ?  ?  ?  ?  Standards Compliant Solution  ?  ?  ?  ?  ?  Bearer & Device Agnostic  ?  ?  ?  ?  ?  Ease of use and accessibility  ?  ?  ?  ?  ?  Synergies...

  17. Geometric information provider platform

    Directory of Open Access Journals (Sweden)

    Meisam Yousefzadeh

    2015-07-01

    Full Text Available Renovation of existing buildings is known as an essential stage in reduction of the energy loss. Considerable part of renovation process depends on geometric reconstruction of building based on semantic parameters. Following many research projects which were focused on parameterizing the energy usage, various energy modelling methods were developed during the last decade. On the other hand, by developing accurate measuring tools such as laser scanners, the interests of having accurate 3D building models are rapidly growing. But the automation of 3D building generation from laser point cloud or detection of specific objects in that is still a challenge.  The goal is designing a platform through which required geometric information can be efficiently produced to support energy simulation software. Developing a reliable procedure which extracts required information from measured data and delivers them to a standard energy modelling system is the main purpose of the project.

  18. Energy Tracking Software Platform

    Energy Technology Data Exchange (ETDEWEB)

    Ryan Davis; Nathan Bird; Rebecca Birx; Hal Knowles

    2011-04-04

    Acceleration has created an interactive energy tracking and visualization platform that supports decreasing electric, water, and gas usage. Homeowners have access to tools that allow them to gauge their use and track progress toward a smaller energy footprint. Real estate agents have access to consumption data, allowing for sharing a comparison with potential home buyers. Home builders have the opportunity to compare their neighborhood's energy efficiency with competitors. Home energy raters have a tool for gauging the progress of their clients after efficiency changes. And, social groups are able to help encourage members to reduce their energy bills and help their environment. EnergyIT.com is the business umbrella for all energy tracking solutions and is designed to provide information about our energy tracking software and promote sales. CompareAndConserve.com (Gainesville-Green.com) helps homeowners conserve energy through education and competition. ToolsForTenants.com helps renters factor energy usage into their housing decisions.

  19. The evolution of tensor polarization

    International Nuclear Information System (INIS)

    Huang, H.; Lee, S.Y.; Ratner, L.

    1993-01-01

    By using the equation of motion for the vector polarization, the spin transfer matrix for spin tensor polarization, the spin transfer matrix for spin tensor polarization is derived. The evolution equation for the tensor polarization is studied in the presence of an isolate spin resonance and in the presence of a spin rotor, or snake

  20. The polarization of fast neutrons

    International Nuclear Information System (INIS)

    Talov, V.V.

    2000-01-01

    The present work is the review of polarization of fast neutrons and methods of polarization analysis. This also includes information about polarization of fast neutrons from first papers, which described polarization in the D(d,n) 3 He, 7 Li(p,n) 7 Be, and T(p,n) 3 He reactions. (authors)

  1. Mafic Materials in Scott Crater? A Test for Lunar Reconnaissance Orbiter

    Science.gov (United States)

    Cooper, Bonnie L.

    2007-01-01

    Clementine 750 nm and multispectral ratio data, along with Lunar Orbiter and radar data, were used to study the crater Scott in the lunar south polar region. The multispectral data provide evidence for mafic materials, impact melts, anorthositic materials, and a small pyroclastic deposit. High-resolution radar data and Lunar Orbiter photography for this area show differences in color and surface texture that correspond with the locations of the hypothesized mafic and anorthositic areas on the crater floor. This region provides a test case for the upcoming Lunar Reconnaissance Orbiter. Verification of the existence of a mafic deposit at this location is relevant to future lunar resource utilization planning.

  2. Vorticity and particle polarization in heavy ion collisions (experimental perspective

    Directory of Open Access Journals (Sweden)

    Voloshin Sergei A.

    2018-01-01

    Full Text Available The recent measurements of the global polarization and vector meson spin alignment along the system orbital momentum in heavy ion collisions are briefly reviewed. A possible connection between the global polarization and the chiral anomalous effects is discussed along with possible experimental checks. Future directions, in particular those aimed on the detailed mapping of the vorticity fields, are outlined. The Blast Wave model is used for an estimate of the anisotropic flow effect on the vorticity component along the beam direction. We also point to a possibility of a circular pattern in the vorticity field in asymmetric, e.g. Cu+Au, central collisions.

  3. Spin-polarized photoemission from SiGe heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Ferrari, A.; Bottegoni, F.; Isella, G.; Cecchi, S.; Chrastina, D.; Finazzi, M.; Ciccacci, F. [LNESS-Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2013-12-04

    We apply the principles of Optical Orientation to measure by Mott polarimetry the spin polarization of electrons photoemitted from different group-IV heterostructures. The maximum measured spin polarization, obtained from a Ge/Si{sub 0.31}Ge{sub 0.69} strained film, undoubtedly exceeds the maximum value of 50% attainable in bulk structures. The explanation we give for this result lies in the enhanced band orbital mixing between light hole and split-off valence bands as a consequence of the compressive strain experienced by the thin Ge layer.

  4. Sinking offshore platform. Nedsenkbar fralandsplatform

    Energy Technology Data Exchange (ETDEWEB)

    Einstabland, T.B.; Olsen, O.

    1988-12-19

    The invention deals with a sinking offshore platform of the gravitational type designed for being installed on the sea bed on great depths. The platform consists of at least three inclining pillars placed on a foundation unit. The pillars are at the upper end connected to a tower structure by means of a rigid construction. The tower supports the platform deck. The rigid construction comprises a centre-positioned cylinder connected to the foundation. 11 figs.

  5. OWLS as platform technology in OPTOS satellite

    Science.gov (United States)

    Rivas Abalo, J.; Martínez Oter, J.; Arruego Rodríguez, I.; Martín-Ortega Rico, A.; de Mingo Martín, J. R.; Jiménez Martín, J. J.; Martín Vodopivec, B.; Rodríguez Bustabad, S.; Guerrero Padrón, H.

    2017-12-01

    The aim of this work is to show the Optical Wireless Link to intraSpacecraft Communications (OWLS) technology as a platform technology for space missions, and more specifically its use within the On-Board Communication system of OPTOS satellite. OWLS technology was proposed by Instituto Nacional de Técnica Aeroespacial (INTA) at the end of the 1990s and developed along 10 years through a number of ground demonstrations, technological developments and in-orbit experiments. Its main benefits are: mass reduction, flexibility, and simplification of the Assembly, Integration and Tests phases. The final step was to go from an experimental technology to a platform one. This step was carried out in the OPTOS satellite, which makes use of optical wireless links in a distributed network based on an OLWS implementation of the CAN bus. OPTOS is the first fully wireless satellite. It is based on the triple configuration (3U) of the popular Cubesat standard, and was completely built at INTA. It was conceived to procure a fast development, low cost, and yet reliable platform to the Spanish scientific community, acting as a test bed for space born science and technology. OPTOS presents a distributed OBDH architecture in which all satellite's subsystems and payloads incorporate a small Distributed On-Board Computer (OBC) Terminal (DOT). All DOTs (7 in total) communicate between them by means of the OWLS-CAN that enables full data sharing capabilities. This collaboration allows them to perform all tasks that would normally be carried out by a centralized On-Board Computer.

  6. Polarized particles in storage rings

    International Nuclear Information System (INIS)

    Derbenev, Ya.S.; Kondratenko, A.M.; Serednyakov, S.I.; Skrinskij, A.N.; Tumajkin, G.M.; Shatunov, Yu.M.

    1977-01-01

    Experiments with polarized beams on the VEPP-2M and SPEAK storage rings are described. Possible methods of producing polarized particle beams in storage rings as well as method of polarization monitoring are counted. Considered are the processes of radiation polarization of electrons and positrons. It is shown, that to preserve radiation polarization the introduction of regions with a strong sign-variable magnetic field is recommended. Methods of polarization measurement are counted. It is suggested for high energies to use dependence of synchrotron radiation power on transverse polarization of electrons and positrons. Examples of using polarizability of colliding beams in storage rings are presented

  7. Polarized electrons at Jefferson laboratory

    International Nuclear Information System (INIS)

    Sinclair, C.K.

    1998-01-01

    The CEBAF accelerator at Jefferson laboratory can deliver CW electron beams to three experimental halls simultaneously. A large fraction of the approved scientific program at the lab requires polarized electron beams. Many of these experiments, both polarized and unpolarized, require high average beam current as well. Since all electrons delivered to the experimental halls originate from the same cathode, delivery of polarized beam to a single hall requires using the polarized source to deliver beam to all experiments in simultaneous operation. The polarized source effort at Jefferson Lab is directed at obtaining very long polarized source operational lifetimes at high average current and beam polarization; at developing the capability to deliver all electrons leaving the polarized source to the experimental halls; and at delivering polarized beam to multiple experimental halls simultaneously. Initial operational experience with the polarized source will be presented. copyright 1998 American Institute of Physics

  8. Polarized Electrons at Jefferson Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, C.K.

    1997-12-31

    The CEBAF accelerator at Jefferson laboratory can deliver CW electron beams to three experimental halls simultaneously. A large fraction of the approved scientific program at the lab requires polarized electron beams. Many of these experiments, both polarized and unpolarized, require high average beam current as well. Since all electrons delivered to the experimental halls originate from the same cathode, delivery of polarized beam to a single hall requires using the polarized source to deliver beam to all experiments in simultaneous operation. The polarized source effort at Jefferson Lab is directed at obtaining very long polarized source operational lifetimes at high average current and beam polarization; at developing the capability to deliver all electrons leaving the polarized source to the experimental halls; and at delivering polarized beam to multiple experimental halls simultaneously.initial operational experience with the polarized source will be presented.

  9. Polarization: A Must for Fusion

    Directory of Open Access Journals (Sweden)

    Guidal M.

    2012-10-01

    Full Text Available Recent realistic simulations confirm that the polarization of the fuel would improve significantly the DT fusion efficiency. We have proposed an experiment to test the persistence of the polarization in a fusion process, using a terawatt laser hitting a polarized HD target. The polarized deuterons heated in the plasma induced by the laser can fuse producing a 3He and a neutron in the final state. The angular distribution of the neutrons and the change in the corresponding total cross section are related to the polarization persistence. The experimental polarization of DT fuel is a technological challenge. Possible paths for Magnetic Confinement Fusion (MCF and for Inertial Confinement Fusion (ICF are reviewed. For MCF, polarized gas can be used. For ICF, cryogenic targets are required. We consider both, the polarization of gas and the polarization of solid DT, emphasizing the Dynamic Nuclear polarization (DNP of HD and DT molecules.

  10. Product Platform Screening at LEGO

    DEFF Research Database (Denmark)

    Mortensen, Niels Henrik; Steen Jensen, Thomas; Nielsen, Ole Fiil

    2012-01-01

    Product platforms offer great benefits to companies developing new products in highly competitive markets. Literature describes how a single platform can be designed from a technical point of view, but rarely mentions how the process begins. How do companies identify possible platform candidates...... after a few changes had been applied to the initial process layout. This case study shows how companies must focus on a limited selection of simultaneous projects in order to keep focus. Primary stakeholders must be involved from the very beginning, and short presentations of the platform concepts...

  11. Flexible experimental FPGA based platform

    DEFF Research Database (Denmark)

    Andersen, Karsten Holm; Nymand, Morten

    2016-01-01

    This paper presents an experimental flexible Field Programmable Gate Array (FPGA) based platform for testing and verifying digital controlled dc-dc converters. The platform supports different types of control strategies, dc-dc converter topologies and switching frequencies. The controller platform...... interface supporting configuration and reading of setup parameters, controller status and the acquisition memory in a simple way. The FPGA based platform, provides an easy way within education or research to use different digital control strategies and different converter topologies controlled by an FPGA...

  12. Study by polarized muon

    International Nuclear Information System (INIS)

    Yamazaki, Toshimitsu

    1977-01-01

    Experiments by using polarized muon beam are reported. The experiments were performed at Berkeley, U.S.A., and at Vancouver, Canada. The muon spin rotation is a useful method for the study of the spin polarization of conductive electrons in paramagnetic Pd metal. The muon Larmor frequency and the relaxation time can be obtained by measuring the time distribution of decay electrons of muon-electron process. The anomalous depolarization of negative muon spin rotation in the transitional metal was seen. The circular polarization of the negative muon X-ray was measured to make clear this phenomena. The experimental results show that the anomalous depolarization is caused at the 1-S-1/2 state. For the purpose to obtain the strong polarization of negative muon, a method of artificial polarization is proposed, and the test experiments are in progress. The study of the hyperfine structure of mu-mesic atoms is proposed. The muon capture rate was studied systematically. (Kato, T.)

  13. Polarized protons at RHIC

    International Nuclear Information System (INIS)

    Tannenbaum, M.J.

    1990-12-01

    The Physics case is presented for the use of polarized protons at RHIC for one or two months each year. This would provide a facility with polarizations of approx-gt 50% high luminosity ∼2.0 x 10 32 cm -2 s -1 , the possibility of both longitudinal and transverse polarization at the interaction regions, and frequent polarization reversal for control of systematic errors. The annual integrated luminosity for such running (∼10 6 sec per year) would be ∫ Ldt = 2 x 10 38 cm -2 -- roughly 20 times the total luminosity integrated in ∼ 10 years of operation of the CERN Collider (∼10 inverse picobarns, 10 37 cm -2 ). This facility would be unique in the ability to perform parity-violating measurements and polarization test of QCD. Also, the existence of p-p collisions in a new energy range would permit the study of ''classical'' reactions like the total cross section and elastic scattering, etc., and serve as a complement to measurements from p-bar p colliders. 11 refs

  14. The Bochum Polarized Target

    International Nuclear Information System (INIS)

    Reicherz, G.; Goertz, S.; Harmsen, J.; Heckmann, J.; Meier, A.; Meyer, W.; Radtke, E.

    2001-01-01

    The Bochum 'Polarized Target' group develops the target material 6 LiD for the COMPASS experiment at CERN. Several different materials like alcohols, alcanes and ammonia are under investigation. Solid State Targets are polarized in magnetic fields higher than B=2.5T and at temperatures below T=1K. For the Dynamic Nuclear Polarization process, paramagnetic centers are induced chemically or by irradiation with ionizing beams. The radical density is a critical factor for optimization of polarization and relaxation times at adequate magnetic fields and temperatures. In a high sensitive EPR--apparatus, an evaporator and a dilution cryostat with a continuous wave NMR--system, the materials are investigated and optimized. To improve the polarization measurement, the Liverpool NMR-box is modified by exchanging the fixed capacitor for a varicap diode which not only makes the tuning very easy but also provides a continuously tuned circuit. The dependence of the signal area upon the circuit current is measured and it is shown that it follows a linear function

  15. Realization of optimized quantum controlled-logic gate based on the orbital angular momentum of light.

    Science.gov (United States)

    Zeng, Qiang; Li, Tao; Song, Xinbing; Zhang, Xiangdong

    2016-04-18

    We propose and experimentally demonstrate an optimized setup to implement quantum controlled-NOT operation using polarization and orbital angular momentum qubits. This device is more adaptive to inputs with various polarizations, and can work both in classical and quantum single-photon regime. The logic operations performed by such a setup not only possess high stability and polarization-free character, they can also be easily extended to deal with multi-qubit input states. As an example, the experimental implementation of generalized three-qubit Toffoli gate has been presented.

  16. MIRAS characterization and monitoring during the SMOS In-Orbit Commissioning Phase

    Science.gov (United States)

    Corbella, I.; Torres, F.; Martin-Neira, M.; Duffo, N.; González-Gambau, V.; Camps, A.; Vall-Llossera, M.

    2009-04-01

    1 Introduction The Microwave Imaging Radiometer with Aperture Synthesis (MIRAS) is the single payload of the Soil Moisture and Ocean Salinity (SMOS) mission. The instrument was completed in early 2007 and thoroughly tested both in anechoic chamber and vacuum thermal chamber during 2007. It was integrated to the platform in early 2008 and re-tested, including compatibility, during 2008. At present, the whole satellite is stowed and waiting to be launched during 2009. In two weeks after launch, the satellite will be in the final orbit with all deployments completed. Then the In-Orbit Commissioning Phase will start, having an estimated duration of 5.5 months. During this phase, the instrument modes of operation will be systematically checked and the calibration parameters will be fully characterized in real conditions. Also, the first brightness temperature images will be obtained in order to assess the overall retrieval procedures including inversion. In the end, the objective of the In-Orbit Commissioning Phase is to provide verification that the payload meets the scientific requirements of the mission. The general design and planning of the In-Orbit Commissioning Phase is given in [1]. This abstract presents the foreseen activities to be performed during this phase by the UPC team. Just after the start of the In-Orbit Commissioning Phase, the instrument will be commanded to perform a sequence of operations oriented at providing a full characterization in terms of calibration parameters. The idea is to reproduce the results obtained during the tests carried out on ground [2]. In particular, the following issues will be covered: Thermal Stability: To provide understanding of both the intra-orbit and inter-orbit temperature variations. The instrument will be continuously operating during a number of orbits while all temperature sensors being monitored. Electrical Stability: To re-compute all internal calibration parameters (gains, offsets, receiver noise temperatures

  17. Introducing Platform Interactions Model for Studying Multi-Sided Platforms

    DEFF Research Database (Denmark)

    Staykova, Kalina; Damsgaard, Jan

    2018-01-01

    Multi-Sided Platforms (MSPs) function as socio-technical entities that facilitate direct interactions between various affiliated to them constituencies through developing and managing IT architecture. In this paper, we aim to explain the nature of the platform interactions as key characteristic o...

  18. Rehabilitation of orbital cavity after orbital exenteration using polymethyl methacrylate orbital prosthesis

    Directory of Open Access Journals (Sweden)

    Sumeet Jain

    2016-01-01

    Full Text Available Squamous cell carcinoma of the eyelid is the second most common malignant neoplasm of the eye with the incidence of 0.09 and 2.42 cases/100 000 people. Orbital invasion is a rare complication but, if recognized early, can be treated effectively with exenteration. Although with advancements in technology such as computer-aided design and computer-aided manufacturing, material science, and retentive methods like implants, orbital prosthesis with stock ocular prosthesis made of methyl methacrylate retained by anatomic undercuts is quiet effective and should not be overlooked and forgotten. This clinical report describes prosthetic rehabilitation of two male patients with polymethyl methacrylate resin orbital prosthesis after orbital exenteration, for squamous cell carcinoma of the upper eyelid. The orbital prosthesis was sufficiently retained by hard and soft tissue undercuts without any complications. The patients using the prosthesis are quite satisfied with the cosmetic results and felt comfortable attending the social events.

  19. POGO satellite orbit corrections: an opportunity to improve the quality of the geomagnetic field measurements?

    DEFF Research Database (Denmark)

    Stockmann, Reto; Christiansen, Freddy; Olsen, Nils

    2015-01-01

    We present an attempt to improve the quality of the geomagnetic field measurements from the Polar Orbiting Geophysical Observatory (POGO) satellite missions in the late 1960s. Inaccurate satellite positions are believed to be a major source of errors for using the magnetic observations for field...... modelling. To improve the data, we use aniterative approach consisting of two main parts: one is a main field modelling process to obtain the radial fieldgradient to perturb the orbits and the other is the state-of-the-art GPS orbit modelling software BERNESE to calculatenew physical orbits. We report....... With this approach, weeliminate the orbit discontinuities at midnight but only tiny quality improvements could be achieved forgeomagnetically quiet data. We believe that improvements to the data are probably still possible, but it would require the original tracking observations to be found....

  20. Detecting a Subsurface Ocean From Periodic Orbits at Enceladus

    Science.gov (United States)

    Casotto, S.; Padovan, S.; Russell, R. P.; Lara, M.

    2008-12-01

    Enceladus is a small icy satellite of Saturn which has been observed by the Cassini orbiter to eject plumes mainly consisting of water vapor from the "tiger stripes" located near its South pole. While tidal heating has been ruled out as an inadequate energy source to drive these eruptions, tidally induced shear stress both along and across the stripes appears to be sufficiently powerful. The internal constitution of Enceladus that fits this model is likely to entail a thin crust and a subcrustal water layer above an undifferentiated interior. Apart from the lack of a core/mantle boundary, the situation is similar to the current hypothetical models of Europa's interior. The determination of the existence of a subsurface fluid layer can therefore be pursued with similar methods, including the study of the gravitational perturbations of tidal origin on an Enceladus orbiter, and the use of altimeter measurements to the tidally deformed surface. The dynamical environment of an Enceladus orbiter is made very unstable by the overwhelming presence of nearby Saturn. The Enceladus sphere of influence is roughly twice its radius. This makes it considerably more difficult to orbit than Europa, whose sphere of influence is ~six times its radius. While low-altitude, near-polar Enceladus orbits suffer extreme instability, recent works have extended the inclination envelope for long-term stable orbits at Enceladus. Several independent methods suggest that ~65 degrees inclination is the maximum attainable for stable, perturbed Keplerian motion. These orbits are non-circular and exist with altitude variations from ~200 to ~300 km. We propose a nominal reference orbit that enjoys long term stability and is favorable for long-term mapping and other scientific experiments. A brief excursion to a lower altitude, slightly higher inclined, yet highly unstable orbit is proposed to improve gravity signatures and enable high resolution, nadir-pointing experiments on the geysers emanating

  1. Large-size space debris flyby in low earth orbits

    Science.gov (United States)

    Baranov, A. A.; Grishko, D. A.; Razoumny, Y. N.

    2017-09-01

    V and with amount of detachable de-orbiting units onboard the maneuvering platform and onboard the refueling vehicle.

  2. Orbital Evolution and Orbital Phase Resolved Spectroscopy of the ...

    Indian Academy of Sciences (India)

    binary. We have carried out orbital phase resolved spectroscopy to mea- ... agreement with a simple model of a spherically symmetric stellar wind from the .... has a set of Narrow Field Instruments (NFI) comprising one Low Energy Concen-.

  3. Orbital Infarction due to Sickle Cell Disease without Orbital Pain

    Directory of Open Access Journals (Sweden)

    Cameron L. McBride

    2016-01-01

    Full Text Available Sickle cell disease is a hemoglobinopathy that results in paroxysmal arteriolar occlusion and tissue infarction that can manifest in a plurality of tissues. Rarely, these infarcted crises manifest in the bony orbit. Orbital infarction usually presents with acute onset of periorbital tenderness, swelling, erythema, and pain. Soft tissue swelling can result in proptosis and attenuation of extraocular movements. Expedient diagnosis of sickle cell orbital infarction is crucial because this is a potentially sight-threatening entity. Diagnosis can be delayed since the presentation has physical and radiographic findings mimicking various infectious and traumatic processes. We describe a patient who presented with sickle cell orbital crisis without pain. This case highlights the importance of maintaining a high index of suspicion in patients with known sickle cell disease or of African descent born outside the United States in a region where screening for hemoglobinopathy is not routine, even when the presentation is not classic.

  4. Polarized source upgrading

    International Nuclear Information System (INIS)

    Clegg, T.B.; Rummel, R.L.; Carter, E.P.; Westerfeldt, C.R.; Lovette, A.W.; Edwards, S.E.

    1985-01-01

    The decision was made this past year to move the Lamb-shift polarized ion source which was first installed in the laboratory in 1970. The motivation was the need to improve the flexibility of spin-axis orientation by installing the ion source with a new Wien-filter spin precessor which is capable of rotating physically about the beam axis. The move of the polarized source was accomplished in approximately two months, with the accelerator being turned off for experiments during approximately four weeks of this time. The occasion of the move provided the opportunity to rewire completely the entire polarized ion source frame and to rebuild approximately half of the electronic chassis on the source. The result is an ion source which is now logically wired and carefully documented. Beams obtained from the source are much more stable than those previously available

  5. Spin polarized deuterium

    International Nuclear Information System (INIS)

    Glyde, H.R.; Hernadi, S.I.

    1986-01-01

    Several ground state properties of (electron) spin-polarized deuterium (D) such as the energy, single quasiparticle energies and lifetimes, Landau parameters and sound velocities are evaluated. The calculations begin with the Kolos-Wolneiwicz potential and use the Galitskii-FeynmanHartree-Fock (GFHF) approximation. The deuteron nucleas has spin I = 1, and spin states I/sub z/ = 1,0,-1. We explore D 1 , D 2 and D 3 in which, respectively, one spin state only is populated, two states are equally populated, and three states are equally populated. We find the GFHF describes D 1 well, but D 2 and D 3 less well. The Landau parameters, F/sub L/, are small compared to liquid 3 He and very small for doubly polarized D 1 (i.e. the F/sub L/ decrease with nuclear polarization)

  6. Polarized electron sources

    International Nuclear Information System (INIS)

    Clendenin, J.E.

    1995-05-01

    Polarized electron sources for high energy accelerators took a significant step forward with the introduction of a new laser-driven photocathode source for the SLC in 1992. With an electron beam polarization of >80% and with ∼99% uptime during continuous operation, this source is a key factor in the success of the current SLC high-energy physics program. The SLC source performance is used to illustrate both the capabilities and the limitations of solid-state sources. The beam requirements for future colliders are similar to that of the SLC with the addition in most cases of multiple-bunch operation. A design for the next generation accelerator source that can improve the operational characteristics and at least minimize some of the inherent limitations of present sources is presented. Finally, the possibilities for producing highly polarized electron beams for high-duty-factor accelerators are discussed

  7. Time Domain Induced Polarization

    DEFF Research Database (Denmark)

    Fiandaca, Gianluca; Auken, Esben; Christiansen, Anders Vest

    2012-01-01

    Time-domain-induced polarization has significantly broadened its field of reference during the last decade, from mineral exploration to environmental geophysics, e.g., for clay and peat identification and landfill characterization. Though, insufficient modeling tools have hitherto limited the use...... of time-domaininduced polarization for wider purposes. For these reasons, a new forward code and inversion algorithm have been developed using the full-time decay of the induced polarization response, together with an accurate description of the transmitter waveform and of the receiver transfer function......, to reconstruct the distribution of the Cole-Cole parameters of the earth. The accurate modeling of the transmitter waveform had a strong influence on the forward response, and we showed that the difference between a solution using a step response and a solution using the accurate modeling often is above 100...

  8. A lunar polar expedition

    Science.gov (United States)

    Dowling, Richard; Staehle, Robert L.; Svitek, Tomas

    1992-09-01

    Advanced exploration and development in harsh environments require mastery of basic human survival skill. Expeditions into the lethal climates of Earth's polar regions offer useful lessons for tommorrow's lunar pioneers. In Arctic and Antarctic exploration, 'wintering over' was a crucial milestone. The ability to establish a supply base and survive months of polar cold and darkness made extensive travel and exploration possible. Because of the possibility of near-constant solar illumination, the lunar polar regions, unlike Earth's may offer the most hospitable site for habitation. The World Space Foundation is examining a scenario for establishing a five-person expeditionary team on the lunar north pole for one year. This paper is a status report on a point design addressing site selection, transportation, power, and life support requirements.

  9. Computed tomography of orbital myositis

    International Nuclear Information System (INIS)

    Dresner, S.C.; Rothfus, W.E.; Slamovits, T.L.; Kennerdell, J.S.; Curtin, H.D.

    1984-01-01

    The computerized tomographic (CT) scans of 11 consecutive patients with orbital myositis were reviewed to better characterize the CT appearance of this condition. The findings in this series differed from those of previous reports in several ways. Multiple muscle involvement predominated. Bilateral involvement was more frequent than previously reported. Enlargement of the tendon as well as the muscle was a frequent finding, but a normal tendinous insertion did not preclude the diagnosis of orbital myositis. Although the CT appearance of orbital myositis is often helpful, the findings are not pathognomonic; correlation with history, clinical findings, and therapeutic response must be considered in making the diagnosis

  10. JSC Orbital Debris Website Description

    Science.gov (United States)

    Johnson, Nicholas L.

    2006-01-01

    Purpose: The website provides information about the NASA Orbital Debris Program Office at JSC, which is the lead NASA center for orbital debris research. It is recognized world-wide for its leadership in addressing orbital debris issues. The NASA Orbital Debris Program Office has taken the international lead in conducting measurements of the environment and in developing the technical consensus for adopting mitigation measures to protect users of the orbital environment. Work at the center continues with developing an improved understanding of the orbital debris environment and measures that can be taken to control its growth. Major Contents: Orbital Debris research is divided into the following five broad efforts. Each area of research contains specific information as follows: 1) Modeling - NASA scientists continue to develop and upgrade orbital debris models to describe and characterize the current and future debris environment. Evolutionary and engineering models are described in detail. Downloadable items include a document in PDF format and executable software. 2) Measurements - Measurements of near-Earth orbital debris are accomplished by conducting ground-based and space-based observations of the orbital debris environment. The data from these sources provide validation of the environment models and identify the presence of new sources. Radar, optical and surface examinations are described. External links to related topics are provided. 3) Protection - Orbital debris protection involves conducting hypervelocity impact measurements to assess the risk presented by orbital debris to operating spacecraft and developing new materials and new designs to provide better protection from the environment with less weight penalty. The data from this work provides the link between the environment defined by the models and the risk presented by that environment to operating spacecraft and provides recommendations on design and operations procedures to reduce the risk as

  11. Modelling Polar Self Assembly

    Science.gov (United States)

    Olvera de La Cruz, Monica; Sayar, Mehmet; Solis, Francisco J.; Stupp, Samuel I.

    2001-03-01

    Recent experimental studies in our group have shown that self assembled thin films of noncentrosymmetric supramolecular objects composed of triblock rodcoil molecules exhibit finite polar order. These aggregates have both long range dipolar and short range Ising-like interactions. We study the ground state of a simple model with these competing interactions. We find that the competition between Ising-like and dipolar forces yield a periodic domain structure, which can be controlled by adjusting the force constants and film thickness. When the surface forces are included in the potential, the system exhibits a finite macroscopic polar order.

  12. AGS polarized H- source

    International Nuclear Information System (INIS)

    Kponou, A.; Alessi, J.G.; Sluyters, T.

    1985-01-01

    The AGS polarized H - source is now operational. During a month-long experimental physics run in July 1984, pulses equivalent to 15 μA x 300 μs (approx. 3 x 10 10 protons) were injected into the RFQ preaccelerator. Beam polarization, measured at 200 MeV, was approx. 75%. After the run, a program to increase the H - yield of the source was begun and significant progress has been made. The H - current is now frequently 20 to 30 μA. A description of the source and some details of our operating experience are given. We also briefly describe the improvement program

  13. The polar mesosphere

    International Nuclear Information System (INIS)

    Morris, Ray; Murphy, Damian

    2008-01-01

    The mesosphere region, which lies at the edge of space, contains the coldest layer of the Earth's atmosphere, with summer temperatures as low as minus 130 °C. In this extreme environment ice aerosol layers have appeared since the dawn of industrialization—whose existence may arguably be linked to human influence—on yet another layer of the Earth's fragile atmosphere. Ground-based and space-based experiments conducted in the Arctic and Antarctic during the International Polar Year (IPY) aim to address limitations in our knowledge and to advance our understanding of thermal and dynamical processes at play in the polar mesosphere

  14. Imaging with Polarized Neutrons

    Directory of Open Access Journals (Sweden)

    Nikolay Kardjilov

    2018-01-01

    Full Text Available Owing to their zero charge, neutrons are able to pass through thick layers of matter (typically several centimeters while being sensitive to magnetic fields due to their intrinsic magnetic moment. Therefore, in addition to the conventional attenuation contrast image, the magnetic field inside and around a sample can be visualized by detecting changes of polarization in a transmitted beam. The method is based on the spatially resolved measurement of the cumulative precession angles of a collimated, polarized, monochromatic neutron beam that traverses a magnetic field or sample.

  15. Polarization splitter and polarization rotator designs based on transformation optics.

    Science.gov (United States)

    Kwon, Do-Hoon; Werner, Douglas H

    2008-11-10

    The transformation optics technique is employed in this paper to design two optical devices - a two-dimensional polarization splitter and a three-dimensional polarization rotator for propagating beams. The polarization splitter translates the TM- and the TE-polarized components of an incident beam in opposite directions (i.e., shifted up or shifted down). The polarization rotator rotates the polarization state of an incoming beam by an arbitrary angle. Both optical devices are reflectionless at the entry and exit interfaces. Design details and full-wave simulation results are provided.

  16. A practice scaffolding interactive platform

    DEFF Research Database (Denmark)

    Bundsgaard, Jeppe

    2009-01-01

    A Practice Scaffolding Interactive Platform (PracSIP) is a social learning platform which supports students in collaborative project based learning by simulating a professional practice. A PracSIP puts the core tools of the simulated practice at the students' disposal, it organizes collaboration...

  17. Paper based electronics platform

    KAUST Repository

    Nassar, Joanna Mohammad

    2017-07-20

    A flexible and non-functionalized low cost paper-based electronic system platform fabricated from common paper, such as paper based sensors, and methods of producing paper based sensors, and methods of sensing using the paper based sensors are provided. A method of producing a paper based sensor can include the steps of: a) providing a conventional paper product to serve as a substrate for the sensor or as an active material for the sensor or both, the paper product not further treated or functionalized; and b) applying a sensing element to the paper substrate, the sensing element selected from the group consisting of a conductive material, the conductive material providing contacts and interconnects, sensitive material film that exhibits sensitivity to pH levels, a compressible and/or porous material disposed between a pair of opposed conductive elements, or a combination of two of more said sensing elements. The method of sensing can further include measuring, using the sensing element, a change in resistance, a change in voltage, a change in current, a change in capacitance, or a combination of any two or more thereof.

  18. Radiation environment measurements and single event upset observations in sun-synchronous orbit

    International Nuclear Information System (INIS)

    Dyer, C.S.; Sims, A.J.; Farren, J.; Stephen, J.; Underwood, C.

    1991-01-01

    This paper reports on analysis of data from the Cosmic Radiation Environment and Dosimetry experiment (CREDO) carried in sun-synchronous polar orbit on UoSat-3 which shows the influence of cosmic rays, trapped protons and solar particles and allows comparison with device behavior

  19. Mapping Enzymatic Catalysis Using the Effective Fragment Molecular Orbital Method: Towards all ab initio Biochemistry

    DEFF Research Database (Denmark)

    Svendsen, Casper Steinmann; Jensen, Jan; Fedorov, Dmitri

    2013-01-01

    We extend the Effective Fragment Molecular Orbital (EFMO) method to the frozen domain approach where only the geometry of an active part is optimized, while the many-body polarization effects are considered for the whole system. The new approach efficiently mapped out the entire reaction path of ...

  20. Polarized Proton Collisions at RHIC

    CERN Document Server

    Bai, Mei; Alekseev, Igor G; Alessi, James; Beebe-Wang, Joanne; Blaskiewicz, Michael; Bravar, Alessandro; Brennan, Joseph M; Bruno, Donald; Bunce, Gerry; Butler, John J; Cameron, Peter; Connolly, Roger; De Long, Joseph; Drees, Angelika; Fischer, Wolfram; Ganetis, George; Gardner, Chris J; Glenn, Joseph; Hayes, Thomas; Hseuh Hsiao Chaun; Huang, Haixin; Ingrassia, Peter; Iriso, Ubaldo; Laster, Jonathan S; Lee, Roger C; Luccio, Alfredo U; Luo, Yun; MacKay, William W; Makdisi, Yousef; Marr, Gregory J; Marusic, Al; McIntyre, Gary; Michnoff, Robert; Montag, Christoph; Morris, John; Nicoletti, Tony; Oddo, Peter; Oerter, Brian; Osamu, Jinnouchi; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Roser, Thomas; Satogata, Todd; Smith, Kevin T; Svirida, Dima; Tepikian, Steven; Tomas, Rogelio; Trbojevic, Dejan; Tsoupas, Nicholaos; Tuozzolo, Joseph; Vetter, Kurt; Wilinski, Michelle; Zaltsman, Alex; Zelenski, Anatoli; Zeno, Keith; Zhang, S Y

    2005-01-01

    The Relativistic Heavy Ion Collider~(RHIC) provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC to avoid depolarizing resonances. In 2003, polarized proton beams were accelerated to 100~GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. RHIC polarized proton run experience demonstrates that optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limite...

  1. Cost Per Pound From Orbit

    Science.gov (United States)

    Merriam, M. L.

    2002-01-01

    Traditional studies of Reusable Launch Vehicle (RLV) designs have focused on designs that are completely reusable except for the fuel. This may not be realistic with current technology . An alternate approach is to look at partially reusable launch vehicles. This raises the question of which parts should be reused and which parts should be expendable. One approach is to consider the cost/pound of returning these parts from orbit. With the shuttle, this cost is about three times the cost/pound of launching payload into orbit. A subtle corollary is that RLVs are much less practical for higher orbits, such as the one on which the International Space Station resides, than they are for low earth orbits.

  2. NASA Orbital Debris Baseline Populations

    Science.gov (United States)

    Krisko, Paula H.; Vavrin, A. B.

    2013-01-01

    The NASA Orbital Debris Program Office has created high fidelity populations of the debris environment. The populations include objects of 1 cm and larger in Low Earth Orbit through Geosynchronous Transfer Orbit. They were designed for the purpose of assisting debris researchers and sensor developers in planning and testing. This environment is derived directly from the newest ORDEM model populations which include a background derived from LEGEND, as well as specific events such as the Chinese ASAT test, the Iridium 33/Cosmos 2251 accidental collision, the RORSAT sodium-potassium droplet releases, and other miscellaneous events. It is the most realistic ODPO debris population to date. In this paper we present the populations in chart form. We describe derivations of the background population and the specific populations added on. We validate our 1 cm and larger Low Earth Orbit population against SSN, Haystack, and HAX radar measurements.

  3. Real and Hybrid Atomic Orbitals.

    Science.gov (United States)

    Cook, D. B.; Fowler, P. W.

    1981-01-01

    Demonstrates that the Schrodinger equation for the hydrogenlike atom separates in both spheroconal and prolate spheroidal coordinates and that these separations provide a sound theoretical basis for the real and hybrid atomic orbitals. (Author/SK)

  4. High Power Orbit Transfer Vehicle

    National Research Council Canada - National Science Library

    Gulczinski, Frank

    2003-01-01

    ... from Virginia Tech University and Aerophysics, Inc. to examine propulsion requirements for a high-power orbit transfer vehicle using thin-film voltaic solar array technologies under development by the Space Vehicles Directorate (dubbed PowerSail...

  5. The Lunar Orbiter Laser Altimeter (LOLA) on NASA's Lunar Reconnaissance Orbiter (LRO) mission

    Science.gov (United States)

    Riris, H.; Cavanaugh, J.; Sun, X.; Liiva, P.; Rodriguez, M.; Neuman, G.

    2017-11-01

    The Lunar Orbiter Laser Altimeter (LOLA) instrument [1-3] on NASA's Lunar Reconnaissance Orbiter (LRO) mission, launched on June 18th, 2009, from Kennedy Space Center, Florida, will provide a precise global lunar topographic map using laser altimetry. LOLA will assist in the selection of landing sites on the Moon for future robotic and human exploration missions and will attempt to detect the presence of water ice on or near the surface, which is one of the objectives of NASA's Exploration Program. Our present knowledge of the topography of the Moon is inadequate for determining safe landing areas for NASA's future lunar exploration missions. Only those locations, surveyed by the Apollo missions, are known with enough detail. Knowledge of the position and characteristics of the topographic features on the scale of a lunar lander are crucial for selecting safe landing sites. Our present knowledge of the rest of the lunar surface is at approximately 1 km kilometer level and in many areas, such as the lunar far side, is on the order of many kilometers. LOLA aims to rectify that and provide a precise map of the lunar surface on both the far and near side of the moon. LOLA uses short (6 ns) pulses from a single laser through a Diffractive Optical Element (DOE) to produce a five-beam pattern that illuminates the lunar surface. For each beam, LOLA measures the time of flight (range), pulse spreading (surface roughness), and transmit/return energy (surface reflectance). LOLA will produce a high-resolution global topographic model and global geodetic framework that enables precise targeting, safe landing, and surface mobility to carry out exploratory activities. In addition, it will characterize the polar illumination environment, and image permanently shadowed regions of the lunar surface to identify possible locations of surface ice crystals in shadowed polar craters.

  6. Topological imprint for periodic orbits

    International Nuclear Information System (INIS)

    Martín, Jesús San; Moscoso, Ma José; Gómez, A González

    2012-01-01

    The more self-crossing points an orbit has the more complex it is. We introduce the topological imprint to characterize crossing points and focus on the period-doubling cascade. The period-doubling cascade topological imprint determines the topological imprint for orbits in chaotic bands. In addition, there is a closer link between this concept and the braids studied by Lettelier et al (2000 J. Phys. A: Math. Gen. 33 1809–25). (paper)

  7. A holistic approach to SIM platform and its application to early-warning satellite system

    Science.gov (United States)

    Sun, Fuyu; Zhou, Jianping; Xu, Zheyao

    2018-01-01

    This study proposes a new simulation platform named Simulation Integrated Management (SIM) for the analysis of parallel and distributed systems. The platform eases the process of designing and testing both applications and architectures. The main characteristics of SIM are flexibility, scalability, and expandability. To improve the efficiency of project development, new models of early-warning satellite system were designed based on the SIM platform. Finally, through a series of experiments, the correctness of SIM platform and the aforementioned early-warning satellite models was validated, and the systematical analyses for the orbital determination precision of the ballistic missile during its entire flight process were presented, as well as the deviation of the launch/landing point. Furthermore, the causes of deviation and prevention methods will be fully explained. The simulation platform and the models will lay the foundations for further validations of autonomy technology in space attack-defense architecture research.

  8. Polarized coincidence electroproduction

    International Nuclear Information System (INIS)

    Heimann, R.L.

    1975-03-01

    A study is made of the inclusive electroproduction of single hadrons off a polarized target. Bjorken scaling laws and the hadron azimuthal distribution are derived from the quark parton model. The polarization asymmetries scale when the target spin is along the direction of the virtual photon, and (apart from significant exception) vanish for transverse spin. These results have a simple explanation; emphasis is given both to the general mathematical formalism and to intuitive physical reasoning. Through this framework other cases are considered: quarks with anomalous magnetic moment; renormalization group effects and asymptotic freedom; production of vector mesons (whose spin state is analysed by their decay); relation to large transverse momentum hadron production; and a covariant parton model calculation. Spin 0 partons and Regge singularities are also considered. All of these cases (apart from the last two) modify the pattern of conclusions. Vector meson production shows polarization enhancements in the density matrix element rhosub(0+); the renormalization group approach does not lead to any significant suppressions. They are also less severe in parton models for large Psub(T) hadrons, and are not supported by the covariantly formulated calculation. The origins of these differences are isolated and used to exemplify the sensitivity polarized hadron electroproduction has to delicate detail that is otherwise concealed. (author)

  9. Fluorescence confocal polarizing microscopy

    Indian Academy of Sciences (India)

    Much of the modern understanding of orientational order in liquid crystals (LCs) is based on polarizing microscopy (PM). A PM image bears only two-dimensional (2D) information, integrating the 3D pattern of optical birefringence over the path of light. Recently, we proposed a technique to image 3D director patterns by ...

  10. Optical neutron polarizers

    International Nuclear Information System (INIS)

    Hayter, J.B.

    1990-01-01

    A neutron wave will be refracted by an appropriately varying potential. Optical neutron polarizers use spatially varying, spin- dependent potentials to refract neutrons of opposite spin states into different directions, so that an unpolarized beam will be split into two beams of complementary polarization by such a device. This paper will concentrate on two methods of producing spin-dependent potentials which are particularly well-suited to polarizing cold neutron beams, namely thin-film structures and field-gradient techniques. Thin-film optical devices, such as supermirror multilayer structures, are usually designed to deviate only one spin-state, so that they offer the possibility of making insertion (transmission) polarizers. Very good supermirrors may now be designed and fabricated, but it is not always straightforward to design mirror-based devices which are useful in real (divergent beam) applications, and some practical configurations will be discussed. Field-gradient devices, which are usually based on multipolar magnets, have tended to be too expensive for general use, but this may change with new developments in superconductivity. Dipolar and hexapolar configurations will be considered, with emphasis on the focusing characteristics of the latter. 21 refs., 7 figs

  11. Titan Polar Landscape Evolution

    Science.gov (United States)

    Moore, Jeffrey M.

    2016-01-01

    With the ongoing Cassini-era observations and studies of Titan it is clear that the intensity and distribution of surface processes (particularly fluvial erosion by methane and Aeolian transport) has changed through time. Currently however, alternate hypotheses substantially differ among specific scenarios with respect to the effects of atmospheric evolution, seasonal changes, and endogenic processes. We have studied the evolution of Titan's polar region through a combination of analysis of imaging, elevation data, and geomorphic mapping, spatially explicit simulations of landform evolution, and quantitative comparison of the simulated landscapes with corresponding Titan morphology. We have quantitatively evaluated alternate scenarios for the landform evolution of Titan's polar terrain. The investigations have been guided by recent geomorphic mapping and topographic characterization of the polar regions that are used to frame hypotheses of process interactions, which have been evaluated using simulation modeling. Topographic information about Titan's polar region is be based on SAR-Topography and altimetry archived on PDS, SAR-based stereo radar-grammetry, radar-sounding lake depth measurements, and superposition relationships between geomorphologic map units, which we will use to create a generalized topographic map.

  12. The polarized EMC effect

    Energy Technology Data Exchange (ETDEWEB)

    W. Bentz; I. C. Cloet; A. W. Thomas

    2007-02-01

    We calculate both the spin independent and spin dependent nuclear structure functions in an effective quark theory. The nucleon is described as a composite quark-diquark state, and the nucleus is treated in the mean field approximation. We predict a sizable polarized EMC effect, which could be confirmed in future experiments.

  13. Polarizer reflectivity variations

    International Nuclear Information System (INIS)

    Ozarski, R.G.; Prior, J.

    1980-01-01

    On Shiva the beam energy along the chain is monitored using available reflections and/or transmission through beam steering, splitting, and polarizing optics without the intrusion of any additional glass for diagnostics. On the preamp table the diagnostic signal is obtained from the signal transmitted through turning mirrors. At the input of each chain the signal is obtained from the transmission through one of the mirrors used for the chain input alignment sensor (CHIP). At the chain output the transmission through the final turning mirror is used. These diagnostics have proved stable and reliable. However, one of the prime diagnostic locations is at the output of the beta rod. The energy at this location is measured by collecting small reflections from the last polarizer surface of the beta Pockels cell polarizer package. Unfortunately, calibration of this diagnostic has varied randomly, seldom remaining stable for a week or more. The cause of this fluctuation has been investigated for the past year and'it has been discovered that polarizer reflectivity varies with humidity. This report will deal with the possible causes that were investigated, the evidence that humidity is causing the variation, and the associated mechanism

  14. Spin-polarized photoemission

    International Nuclear Information System (INIS)

    Johnson, Peter D.

    1997-01-01

    Spin-polarized photoemission has developed into a versatile tool for the study of surface and thin film magnetism. In this review, we examine the methodology of the technique and its application to a number of different problems, including both valence band and core level studies. After a detailed review of spin-polarization measurement techniques and the related experimental requirements we consider in detail studies of the bulk properties both above and below the Curie temperature. This section also includes a discussion of observations relating to unique metastable phases obtained via epitaxial growth. The application of the technique to the study of surfaces, both clean and adsorbate covered, is reviewed. The report then examines, in detail, studies of the spin-polarized electronic structure of thin films and the related interfacial magnetism. Finally, observations of spin-polarized quantum well states in non-magnetic thin films are discussed with particular reference to their mediation of the oscillatory exchange coupling in related magnetic multilayers. (author)

  15. Polarization of Bremsstrahlung

    International Nuclear Information System (INIS)

    Miller, J.

    1957-01-01

    The numerical results for the polarization of Bremsstrahlung are presented. The multiple scattering of electrons in the target is taken into account. The angular-and photon energy dependences are seen on the curves for an incident 25 MeV electron energy. (Author) [fr

  16. No More Polarization, Please!

    DEFF Research Database (Denmark)

    Hansen, Mia Reinholt

    and the increasing levels of complexities it entails, such polarization is not fruitful in the attempt to explain motivation of organizational members. This paper claims that a more nuanced perspective on motivation, acknowledging the co-existence of intrinsic and extrinsic motivation, the possible interaction...

  17. DESY: HERA polarization

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The new HERA electron-proton collider at DESY in Hamburg achieved the first luminosity for electron-proton collisions on 19 October last year. Only one month later, on 20 November, HERA passed another important milestone with the observation of transverse electron polarization

  18. Polarized Neutron Scattering

    OpenAIRE

    Roessli, B.; Böni, P.

    2000-01-01

    The technique of polarized neutron scattering is reviewed with emphasis on applications. Many examples of the usefulness of the method in various fields of physics are given like the determination of spin density maps, measurement of complex magnetic structures with spherical neutron polarimetry, inelastic neutron scattering and separation of coherent and incoherent scattering with help of the generalized XYZ method.

  19. DESY: HERA polarization

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1992-03-15

    The new HERA electron-proton collider at DESY in Hamburg achieved the first luminosity for electron-proton collisions on 19 October last year. Only one month later, on 20 November, HERA passed another important milestone with the observation of transverse electron polarization.

  20. Graphics of polar figure

    International Nuclear Information System (INIS)

    Macias B, L.R.

    1991-11-01

    The objective of this work, is that starting from a data file coming from a spectra that has been softened, and of the one that have been generated its coordinates to project it in stereographic form, to create the corresponding polar figure making use of the Cyber computer of the ININ by means of the GRAPHOS package. This work only requires a Beta, Fi and Intensity (I) enter data file. It starts of the existence of a softened spectra of which have been generated already with these data, making use of some language that in this case was FORTRAN for the Cyber computer, a program is generated supported in the Graphos package that allows starting of a reading of the Beta, Fi, I file, to generate the points in a stereographic projection and that it culminates with the graph of the corresponding polar figure. The program will request the pertinent information that is wanted to capture in the polar figure just as: date, name of the enter file, indexes of the polar figure, number of levels, radio of the stereographic projection (cms.), crystalline system to which belongs the sample, name the neuter graph file by create and to add the own general data. (Author)