Sample records for wedge-shaped polarizing analyzer

  1. Large scale test of wedge shaped micro strip gas counters

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, M.; Atz, S.; Aulchenko, V.; Bachmann, S.; Baiboussinov, B.; Barthe, S.; Beaumont, W.; Beckers, T.; Beissel, F.; Benhammou, Y.; Bergdolt, A.M.; Bernier, K.; Bluem, P.; Bondar, A.; Bouhali, O.; Boulogne, I.; Bozzo, M.; Brom, J.M.; Camps, C.; Chorowicz, V.; Coffin, J.; Commichau, V.; Contardo, D.; Croix, J.; Troy, J. de; Drouhin, F.; Eberle, H.; Fluegge, G.; Fontaine, J.-C.; Geist, W.; Goerlach, U.; Gundlfinger, K.; Hangarter, K.; Haroutunian, R.; Helleboid, J.M.; Henkes, Th.; Hoffer, M.; Hoffman, C.; Huss, D.; Ischebeck, R.; Jeanneau, F.; Juillot, P.; Junghans, S.; Kapp, M.R.; Kaercher, K.; Knoblauch, D.; Kraeber, M.; Krauth, M.; Kremp, J.; Lounis, A.; Luebelsmeyer, K.; Maazouzi, C.; Macke, D.; Metri, R.; Mirabito, L.; Mueller, Th.; Nagaslaev, V.; Neuberger, D.; Nowack, A.; Pallares, A.; Pandoulas, D.; Petertill, M.; Pooth, O.; Racca, C.; Ripp, I.; Ruoff, E.; Sauer, A.; Schmitz, P.; Schulte, R.; Schultz von Dratzig, A.; Schunk, J.P.; Schuster, G.; Schwaller, B.; Shektman, L.; Siedling, R.; Sigward, M.H.; Simonis, H.J.; Smadja, G.; Stefanescu, J.; Szczesny, H.; Tatarinov, A.; Thuemmel, W.H.; Tissot, S.; Titov, V.; Todorov, T.; Tonutti, M.; Udo, F.; Velde, C. Vander. E-mail:; Doninck, W. van; Dyck, Ch. van; Vanlaer, P.; Lancker, L. van; Verdini, P.G.; Weseler, S.; Wittmer, B.; Wortmann, R.; Zghiche, A.; Zhukov, V


    In order to check the system aspects of the forward-backward MSGC tracker designed for the future CMS experiment at LHC, 38 trapezoidal MSGC counters assembled in six multi-substrates detector modules were built and exposed to a muon beam at the CERN SPS. Results on the gain uniformity along the wedge-shaped strip pattern and across the detector modules are shown together with measurements of the detection efficiency and the spatial resolution.

  2. Large scale test of wedge shaped micro strip gas counters

    CERN Document Server

    Ackermann, M; Aulchenko, V M; Bachmann, S; Baibusinov, B O; Barthe, S; Beaumont, W; Beckers, T; Beissel, F; Benhammou, Ya; Bergdolt, A M; Bernier, K; Blüm, H P; Bondar, A E; Bouhali, O; Boulogne, I; Bozzo, M; Brom, J M; Camps, C; Chorowicz, V; Coffin, J P; Commichau, V; Contardo, D; Croix, J; De Troy, J G; Drouhin, F; Eberle, H; Flügge, G; Fontaine, J C; Geist, Walter M; Goerlach, U; Gundlfinger, K; Hangarter, K; Haroutunian, R; Helleboid, J M; Henkes, T; Hoffer, M; Hoffmann, C; Huss, D; Ischebeck, R; Jeanneau, F; Juillot, P; Junghans, S; Kapp, M R; Kärcher, K; Knoblauch, D; Kräber, M H; Krauth, M; Kremp, J; Lounis, A; Lübelsmeyer, K; Maazouzi, C; Macke, D; Metri, R; Mirabito, L; Müller, T; Nagaslaev, V; Neuberger, D; Nowak, A; Pallarès, A; Pandoulas, D; Petertill, M; Pooth, O; Racca, C; Ripp, I; Ruoff, E; Sauer, A; Schmitz, P; Schulte, R; Schultz von Dratzig, A; Schunk, J P; Schuster, G; Schwaller, B; Shekhtman, L I; Siedling, R; Sigward, M H; Simonis, H J; Smadja, G; Stefanescu, J; Szczesny, H; Tatarinov, A A; Thümmel, W H; Tissot, S; Titov, V; Todorov, T; Tonutti, M; Udo, Fred; Van der Velde, C; Van Doninck, W K; Van Dyck, C; Vanlaer, P; Van Lancker, L; Verdini, P G; Weseler, S; Wittmer, B; Wortmann, R; Zghiche, A; Zhukov, V


    In order to check the system aspects of the forward-backward MSGC tracker designed for the future CMS experiment at LHC, 38 trapezoidal MSGC counters assembled in six multi-substrates detector modules were built and exposed to a muon beam at the CERN SPS. Results on the gain uniformity along the wedge-shaped strip pattern and across the detector modules are shown together with measurements of the detection efficiency and the spatial resolution. (8 refs).

  3. Capillary Pressure in a Wedge-Shaped Channel from Pore-Scale Imaging (United States)

    Liu, Y.; Pyrak-Nolte, L. J.; Nolte, D. D.; Giordano, N. J.


    Our previous experimental investigations of capillary pressure in two-dimensional porous structures observed that, just prior to breakthrough, a deviation occurs between the externally measured capillary pressure and the capillary pressure measured from interfacial curvature. To explore this deviation, we used laser confocal microscopy to image the three-dimensional fluid distribution of two immiscible fluids in a simple wedge-shaped channel to determine whether this deviation occurs from the hidden curvature or the presence of thin films. The wedge-shaped channel was fabricated using two different approaches: two-photon polymerization and broad-illumination photolithography. Both techniques use UV-sensitive photoresist (SU-8) to construct a wedge-shaped micromodel containing a channel that is 100 microns wide at the inlet and 20 microns wide at the outlet with a constant channel depth of 40 microns. A Zeiss LSM 510 Laser Scanning Confocal Microscope was used to image the air and water distributions within the micromodel. Initially, the micromodel was saturated withwater containing Alex Fluor-488 or FITC solution by 1%wt. In these experiments, water is the wetting phase and air is the non-wetting phase. A series of drainage and imbibition cycles were performed by incrementing or decrementing the air pressure appropriately. For each increment in pressure, the system was allowed to equilibrate and then a z-stack scan of the fluid distribution was collected with the confocal microscope. The confocal images were analyzed to extract the volume saturation of air and water, the curvature of the three-dimensional fluid-air interface, and the interfacial area per volume. We observed a hysteretic relationship between capillary pressure and wetting phase saturation for the wedge-shaped channel. An analysis of the capillary pressure from interfacial curvature found that initially the calculated and measured values of capillary pressure were equal. However, as breakthrough was

  4. Metamaterials based on wedge-shaped electrodynamic structures

    Directory of Open Access Journals (Sweden)

    Mitrokhin Vladimir


    Full Text Available The paper studies a possibility of simulation of artificial composite media with negative values of the real part of the equivalent dielectric (magnetic permittivity, by the use of segments of hollow composite waveguides with cylindrical guided waves in evanescent mode. Reactive evanescent fields of wedge-shaped waveguide eigenmodes are formed in the evanescent region before the critical section of the waveguide which separates the quasistatic field region from the distributing field of the evanescent waveguide mode. The possibility of simulation is determined by the equivalence of dispersion equation of the eigenmode propagation constant and the dispersion equation for the electric (magnetic permittivity of plasma-like medium if cut-off frequency and electric (magnetic plasma frequency of the medium are equal.

  5. Wedge-shaped parenchymal enhancement peripheral to the hepatic hemangioma : two-phase spiral CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyoung Won; Kim, Tae Kyoung; Han, Joon Koo [College of Medicine and The Institute of Radiation Medicine, Seoul National University, Seoul (Korea, Republic of); Kim, Ah Young; Lee, Hyun Ju [Asan Medical Center, University of Ulsan , Asan (Korea, Republic of); Song, Chi Sung; Choi, Byung Ihn [Seoul City Boramae Hospital, Seoul (Korea, Republic of)


    To determine the incidence of hepatic hemangiomas associated with wedge-shaped parenchymal enhancements adjacent to the tumors as seen on two-phase spiral CT images obtained during the hepatic arterial phase and to characterize the two-phase spiral CT findings of those hemangiomas. One hundred and eight consecutive hepatic hemangiomas in 63 patients who underwent two-phase spiral CT scanning during an 11-month period were included in this study. Two-phase spiral CT scans were obtained during the hepatic arterial phase (30-second delay) and portal venous phase (65-second delay) after injection of 120 mL of contrast material at a rate of 3 mL/sec. We evaluated the frequency with which wedge-shaped parenchymal enhancement was adjacent to the hemangiomas during the hepatic arterial phase and divided hemangiomas into two groups according to whether or not wedge-shaped parenchymal enhancement was noted (Group A and Group B). The presence of such enhancement in hemangiomas was correlated with tumor size and the grade of intratumoral enhancement. In 24 of 108 hemangiomas, wedge-shaped parenchymal enhancement adjacent to hepatic tumors was seen on two-phase CT images obtained during the hepatic arterial phase. Mean hemangioma size was 22mm in group A and 24mm in group B. There was no statistically significant relationship between lesion size and the presence of wedge-shaped parenchymal enhancement adjacent to a hemangioma. In 91.7% and 100% of tumors in Group A, and in 9.6% and 17.8% in Group B, hemangiomas showed more than 50% intratumoral enhancement during the arterial and portal venous phase, respectively. Wedge-shaped parenchymal enhancements peripheral to hepatic hemangiomas was more frequently found in tumors showing more than 50% intratumoral enhancement during these two phases (p less than 0.01). Wedge-shaped parenchymal enhancements is not uncommonly seen adjacent to hepatic hemangiomas on two-phase spiral CT images obtained during the hepatic arterial phase. A

  6. A Novel Continuous Extrusion Process to Fabricate Wedge-Shaped Light Guide Plates

    Directory of Open Access Journals (Sweden)

    Wen-Tse Hsiao


    Full Text Available Backlight modules are key components in thin-film transistor liquid crystal displays (TFT-LCD. Among the components of a backlight module, the light guide plate (LGP plays the most important role controlling the light projected to the eyes of users. A wedge-shaped LGP, with its asymmetrical structure, is usually fabricated by an injection proces, but the fabrication time of this process is long. This study proposes a continuous extrusion process to fabricate wedge-shaped LGPs. This continuous process has advantages for mass production. Besides a T-die and rollers, this system also has an in situ monitor of the melt-bank that forms during the extrusion process, helping control the plate thickness. Results show that the melt bank has a close relationship with the plate thickness. The temperature of the bottom heater and roller was adjusted to reduce the surface deformation of the wedge-shaped plate. This continuous extrusion system can successfully manufacture wedge-shaped LGPs for mass production.

  7. [Teeth wedge-shaped defects in adults of different age groups: remark to prevention and treatment]. (United States)

    Iordanishvili, A K; Pikhur, O L; Cherni, D A

    The aim of the study was to assess the treatment of teeth wedge defects in different age groups. Records of 383 patients (125 males and 258 females aged 22-85 years) treated in outpatient dental facilities with different ownership forms. It is shown that the medical care of patients with wedge-shaped teeth defects routinely consists of remineralization therapy and restoration of anatomical teeth shape regardless of the form of ownership. The extensiveness of dental rehabilitation as well as the use of more modern technologies are typical for private clinics and 96-100% of patients finished their treatment there. In the state and departmental institutions complete rehabilitation of wedge-shaped defects was provided in 45.5-58.0% and 54.3-83.9, respectively. The paper also highlights the drawbacks of primary medical documentation identified in medical institutions of all forms of ownership.

  8. Analyzing polarization swings in 3C 279

    Directory of Open Access Journals (Sweden)

    Kiehlmann S.


    Full Text Available Quasar 3C 279 is known to exhibit episodes of optical polarization angle rotation. We present new, well-sampled optical polarization data for 3C 279 and introduce a method to distinguish between random and deterministic electric vector position angle (EVPA variations. We observe EVPA rotations in both directions with different amplitudes and find that the EVPA variation shows characteristics of both random and deterministic cases. Our analysis indicates that the EVPA variation is likely dominated by a random process in the low brightness state of the jet and by a deterministic process in the flaring state.

  9. Numerical simulation of natural convection in wedge-shaped domain with isothermal free surface (United States)

    Yaroslavtseva, N. A.; Ivanov, N. G.


    The contribution deals with 2D laminar unsteady natural convection in a wedge-shaped reservoir model induced by the isothermal surface heating of a water basin being colder than surrounding atmosphere. The problem formulation considered corresponds to large-scale convection development during a cloudy day when the solar radiation impact is negligible. Numerical simulation was performed using an in-house Navier-Stokes code SINF. The focus of the paper is on the accurate resolution of the initial period of the convective circulation pattern development. The dependence of the predicted convective structures on the computational domain size as well as on the boundary condition at the free surface is analysed. The influence of geometry on the buoyancy-induced flow formation is discussed.

  10. Polarized 3He Gas Circulating Technologies for Neutron Analyzers

    Energy Technology Data Exchange (ETDEWEB)

    Watt, David [Xemed LLC, Durham, NH (United States); Hersman, Bill [Xemed LLC, Durham, NH (United States)


    We describe the development of an integrated system for quasi-continuous operation of a large volume neutron analyzer. The system consists of a non-magnetic diaphragm compressor, a prototype large volume helium polarizer, a surrogate neutron analyzer, a non-depolarizing gas storage reservoir, a non-ferrous valve manifold for handling gas distribution, a custom rubidium-vapor gas return purifier, and wire-wound transfer lines, all of which are immersed in a two-meter external magnetic field. Over the Phase II period we focused on three major tasks required for the successful deployment of these types of systems: 1) design and implementation of gas handling hardware, 2) automation for long-term operation, and 3) improvements in polarizer performance, specifically fabrication of aluminosilicate optical pumping cells. In this report we describe the design, implementation, and testing of the gas handling hardware. We describe improved polarizer performance resulting from improved cell materials and fabrication methods. These improvements yielded valved 8.5 liter cells with relaxation times greater than 12 hours. Pumping this cell with 1500W laser power with 1.25nm linewidth yielded peak polarizations of 60%, measured both inside and outside the polarizer. Fully narrowing this laser to 0.25nm, demonstrated separately on one stack of the four, would have allowed 70% polarization with this cell. We demonstrated the removal of 5 liters of polarized helium from the polarizer with no measured loss of polarization. We circulated the gas through a titanium-clad compressor with polarization loss below 3% per pass. We also prepared for the next phase of development by refining the design of the polarizer so that it can be engineer-certified for pressurized operation. The performance of our system far exceeds comparable efforts elsewhere.

  11. Stationary bubble formation and cavity collapse in wedge-shaped hoppers

    CERN Document Server

    Yagisawa, Yui; Okumura, Ko


    The hourglass is one of the apparatuses familiar to everyone, but reveals intriguing behaviors peculiar to granular materials, and many issues are remained to be explored. In this study, we examined the dynamics of falling sand in a special form of hourglass, i.e., a wedge-shaped hopper, when a suspended granular layer is stabilized to a certain degree. As a result, we found remarkably different dynamics, bubbling and cavity regimes. In the bubbling regime, bubbles of nearly equal size are created in the sand at a regular time interval. In the cavity regime, a cavity grows as sand beads fall before a sudden collapse of the cavity. Bubbling found here is quite visible to a level never discussed in the physics literature and the cavity regime is a novel phase, which is neither continuous, intermittent nor completely blocked phase. We elucidate the physical conditions necessary for the bubbling and cavity regimes and develop simple theories for the regimes to successfully explain the observed phenomena by consid...

  12. Second-harmonic patterned polarization-analyzed reflection confocal microscope (United States)

    Okoro, Chukwuemeka; Toussaint, Kimani C.


    We introduce the second-harmonic patterned polarization-analyzed reflection confocal (SPPARC) microscope-a multimodal imaging platform that integrates Mueller matrix polarimetry with reflection confocal and second-harmonic generation (SHG) microscopy. SPPARC microscopy provides label-free three-dimensional (3-D), SHG-patterned confocal images that lend themselves to spatially dependent, linear polarimetric analysis for extraction of rich polarization information based on the Mueller calculus. To demonstrate its capabilities, we use SPPARC microscopy to analyze both porcine tendon and ligament samples and find differences in both circular degree-of-polarization and depolarization parameters. Moreover, using the collagen-generated SHG signal as an endogenous counterstain, we show that the technique can be used to provide 3-D polarimetric information of the surrounding extrafibrillar matrix plus cells or EFMC region. The unique characteristics of SPPARC microscopy holds strong potential for it to more accurately and quantitatively describe microstructural changes in collagen-rich samples in three spatial dimensions.

  13. Computational analysis of responses of a wedge-shaped-tip optical fiber probe in bubble measurement. (United States)

    Sakamoto, A; Saito, T


    Optical-fiber probing is widely employed in bubble/droplet measurement in gas-liquid two-phase flows. Several types of optical fiber probes with a very high S/N ratio and high performance have been developed, but further improvement in the probes' measurement accuracy and reliability for industrial applications is desired. We tried to eliminate optical noise in the probe measurements, and we found that the signals include some peak signs that have potential for advanced measurement with optical-fiber probing. We developed a ray-tracing numerical simulator and identified the mechanisms underlying the generation of the signals. In order to numerically simulate the optical probing signals, the simulator must use 3D frameworks composed of incident beams, the reflection and refraction on the surfaces of the optical elements (i.e., an optical fiber, a sensing tip, an air phase, and a water phase), and beams returning from the sensing tip to the other tip through the fiber. We used all of these in a simple rendering framework based on a ray-tracing algorithm with Fresnel's law, and we observed the mechanism of some promising signals that may be useful for extracting the hidden potential of optical-fiber probing. To verify the simulator's performance, we carried out three comparative experiments with fundamental setups using a wedge-shaped single-tip optical fiber probe, examining: (1) the beam trajectories and energy leaking out from the sensing tip into the surrounding air phase or water phase, (2) the probing signals throughout penetration of the sensing tip at the air-water free interface in light of the three-dimensional deformation, and (3) the probing signals throughout penetration of the sensing tip into a bubble in light of the three-dimensional bubble shape. As a result, (a) we found that an optical fiber probe with a wedge-shaped tip has particular characteristics of beam emissions from the tip, and the emitting angles switched depending on the phases covering

  14. Polarized 3He gas circulating technologies for neutron analyzers

    Energy Technology Data Exchange (ETDEWEB)

    Watt, David W. [Xemed, LLC, Durham, NH (United States)


    We outline our project to develop a circulating polarized helium-3 system for developing of large, quasi-continuously operating neutron analyzers. The project consisted of four areas: 1) Development of robust external cavity narrowed diode laser output with spectral line width < 0.17 nm and power of 2000 W. 2) Development of large glass polarizing cells using cell surface treatments to obtain long relaxation lifetimes. 3) Refinements of the circulation system with an emphasis on gas purification and materials testing. 4) Design/fabrication of a new polarizer system. 5) Preliminary testing of the new polarizer. 1. Developed Robust High-Power Narrowed Laser The optical configuration of the laser was discussed in the proposal and will be reviewed in the body of this report. The external cavity is configured to mutually lock the wavelength of five 10-bar laser stacks. All the logistical milestones were been met and critical subsystems- laser stack manifold and power divider, external laser cavity, and output telescope- were assembled and tested at low power. Each individual bar is narrowed to ~0.05 nm; when combined the laser has a cumulative spectral width of 0.17 nm across the entire beam due to variations of the bars central wavelength by +/- 0.1 nm, which is similar to that of Volume Bragg Grating narrowed laser bars. This configuration eliminates the free-running “pedestal” that occurs in other external cavity diode lasers. The full-scale laser was completed in 2016 and was used in both the older and newer helium polarizers. This laser was operated at 75% power for periods of up to 8 hours. Once installed, the spectrum became slightly broader (~.25 nm) at full power; this is likely due to very slight misalignments that occurred during handling. 2. Developed the processes to create uniform sintered sol-gel coatings. Our work on cell development comprised: 1) Production of large GE180 cells and explore different means of cell preparation, and 2) Development of

  15. Circular polarization analyzer with polarization tunable focusing of surface plasmon polaritons

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Sen; Zhang, Yan, E-mail: [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Beijing Key Laboratory for Metamaterials and Devices, and Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048 (China); Wang, Xinke [Beijing Key Laboratory for Metamaterials and Devices, and Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048 (China); Kan, Qiang [State Key Laboratory for Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Qu, Shiliang [Optoelectronics Department, Harbin Institute of Technology at Weihai, Weihai 264209 (China)


    A practical circular polarization analyzer (CPA) that can selectively focus surface plasmon polaritons (SPPs) at two separate locations, according to the helicity of the circularly polarized light, is designed and experimentally verified in the terahertz frequency range. The CPA consists of fishbone-slit units and is designed using the simulated annealing algorithm. By differentially detecting the intensities of the two SPPs focuses, the helicity of the incident circularly polarized light can be obtained and the CPA is less vulnerable to the noise of incident light. The proposed device may also have wide potential applications in chiral SPPs photonics and the analysis of chiral molecules in biology.

  16. Numerical Study of a Three Dimensional Interaction between two bow Shock Waves and the Aerodynamic Heating on a Wedge Shaped Nose Cone (United States)

    Wu, N.; Wang, J. H.; Shen, L.


    This paper presents a numerical investigation on the three-dimensional interaction between two bow shock waves in two environments, i.e. ground high-enthalpy wind tunnel test and real space flight, using Fluent 15.0. The first bow shock wave, also called induced shock wave, which is generated by the leading edge of a hypersonic vehicle. The other bow shock wave can be deemed objective shock wave, which is generated by the cowl clip of hypersonic inlet, and in this paper the inlet is represented by a wedge shaped nose cone. The interaction performances including flow field structures, aerodynamic pressure and heating are analyzed and compared between the ground test and the real space flight. Through the analysis and comparison, we can find the following important phenomena: 1) Three-dimensional complicated flow structures appear in both cases, but only in the real space flight condition, a local two-dimensional type IV interaction appears; 2) The heat flux and pressure in the interaction region are much larger than those in the no-interaction region in both cases, but the peak values of the heat flux and pressure in real space flight are smaller than those in ground test. 3) The interaction region on the objective surface are different in the two cases, and there is a peak value displacement of 3 mm along the stagnation line.


    Hamermesh, M.; Hanna, S.S.; Perlow, G.J.


    A method of polarizing and resolving the plane of polarization of gamma rays is described. Polarization is produced by positioning a thin disc of ferromagnetic metal, cortaining /sup 57/Co, in a magnetic field. Resolution is accomplished by rotating a thin disc of iron enriched in /sup 57/Fe relative to a second magnetic field and noting the change of gamma absorption at each rotational position. (AEC)

  18. A microfabricated wedge-shaped adhesive array displaying gecko-like dynamic adhesion, directionality and long lifetime. (United States)

    Parness, Aaron; Soto, Daniel; Esparza, Noé; Gravish, Nick; Wilkinson, Matt; Autumn, Kellar; Cutkosky, Mark


    Gecko adhesion has become a paradigmatic example of bio-inspired engineering, yet among the many gecko-like synthetic adhesives (GSAs), truly gecko-like performance remains elusive. Many GSAs have previously demonstrated one or two features of the gecko adhesive. We present a new wedge-shaped GSA that exhibits several gecko-like properties simultaneously: directional features; zero force at detachment; high ratio of detachment force to preload force; non-adhesive default state; and the ability to maintain performance while sliding, even after thousands of cycles. Individual wedges independently detach and reattach during sliding, resulting in high levels of shear and normal adhesion during drag. This behaviour provides a non-catastrophic failure mechanism that is desirable for applications such as climbing robots where sudden contact failure would result in serious falls. The effects of scaling patch sizes up to tens of square centimetres are also presented and discussed. Patches of 1 cm(2) had an adhesive pressure of 5.1 kPa while simultaneously supporting 17.0 kPa of shear. After 30 000 attachment/detachment cycles, a patch retained 67 per cent of its initial adhesion and 76 per cent of its initial shear without cleaning. Square-based wedges of 20 mum and 50 mum are manufactured in a moulding process where moulds are fabricated using a dual-side, dual-angle lithography process on quartz wafers with SU-8 photoresist as the mould material and polydimethylsiloxane as the cast material.

  19. [Effects of different tooth preparations on the fracture behavior of teeth with severe wedge-shaped defect restored with post and core crowns]. (United States)

    Feng, Dandan; Qi, Dong; Lin, Xuefen; Ding, Tingting; Ji, Ping


    This study aimed to investigate the effects of different tooth preparations on the fracture strength and pattern of failure of teeth with severe wedge-shaped defect restored with post and core crowns. According to whether the teeth above the wedge-shaped defect was removed (represented by B) or not (represented by A), the ferrule next to the wedge-shaped defect was prepared (represented by D) or not (represented by C), the cast post-and-core was chosen (represented by E) or glass-fiber post and resin core was chosen (represented by F). A total of 64 human mandibular premolar teeth were randomly divided into 8 groups: A1-1 (A + C + E), A1-2 (A + C + F), A2-1 (A + D + E), A2-2 (A + D + F), B1-1 (B + C + E), B1-2 (B + C + F), B2-1 (B + D + E), B2-2 (B + D + F), each group 8 teeth. All the teeth were prepared and restored accordingly and then mounted on an electronic pressure universal testing machine. The maximum fracture strength and the patterns of failure were recorded. 1) The fracture strength of Group A1-1 > that of Group B1-1, Group A1-2 > Group B1-2, Group B2-1 > Group B1-1, and Group B2-1 > Group B2-2 with significant differences (P crown. The ferrule of the wedge-shaped defect is not recommended to be prepared. Furthermore, the glass-fiber post and resin core is favorable for the re-repair of the teeth than the cast post and core.

  20. High efficient coupling between wedged-shaped fiber and planar lightwave circuit chip using gradient refractive-index media (United States)

    Liu, Xu; Qu, Shuting; Xiao, Jinbiao; Sun, Xiaohan


    Planar lightwave circuit (PLC) chips based on III-V semiconductor MQW rib waveguide promise to be not only a solution to information access, but also direct the issues of bandwidth, pin count, reliability and complexity. Nanopositioning and precision alignment addresses vital importance in high-efficient connectivity between PLC chips and fiber arrays. Refractive-index mismatching between fused silica and III-V compound is one of the most serious problem which remains unsolved on one hand as well as mode field mismatching which can be mitigated in other hand through gradient geometry structure such as tapered spot size converter (SSC) and specialty fibers such as wedge-shaped fiber (WSF). Spherical gradient refractive-index (SGRIN) media intervened between WSF and MQW rib waveguide is put forward. The GRIN media virtually eliminates the reflection losses associated with the fused silica-air interface and III-V semiconductor-air interface. The beam spot emitted from WSF are observed by digital camera and the fundamental mode of MQW rib waveguide was calculated out. Lightwave propagation and mode field evolution in the WSF-SGRIN-PLC system is simulated by FDTD method with the coupling loss of 8.54dB at a wavelength of 1.55μm. An LED signal is injected into WSF, transmitted along GRIN media and PLC waveguide and output through single mode fiber (SMF). Optical power meter-based measurement verifies the whole system coupling loss to be consistent with the numeric estimation. The approach provides an experimental prototype for coupling and packaging technique of integrated photonic devices, hence supplying foundation for photonic network.

  1. Radio frequency source of a weakly expanding wedge-shaped xenon ion beam for contactless removal of large-sized space debris objects. (United States)

    Balashov, Victor; Cherkasova, Maria; Kruglov, Kirill; Kudriavtsev, Arseny; Masherov, Pavel; Mogulkin, Andrey; Obukhov, Vladimir; Riaby, Valentin; Svotina, Victoria


    A theoretical-experimental research has been carried out to determine the characteristics of a radio frequency (RF) ion source for the generation of a weakly expanding wedge-shaped xenon ion beam. Such ion beam geometry is of interest as a prototype of an on-board ion injector for contactless "ion shepherding" by service spacecraft to remove large space debris objects from geostationary orbits. The wedge shape of the ion beam increases its range. The device described herein comprises an inductive gas discharge chamber and a slit-type three-electrode ion extraction grid (IEG) unit. Calculations of accelerating cell geometries and ion trajectories determined the dependence of beam expansion half-angle on normalized perveance based on the measurements of the spatial distributions of the xenon plasma parameters at the IEG entrance for a xenon flow rate q ≈ 0.2 mg/s and an incident RF power Pin ≤ 250 W at a driving frequency f = 2 MHz. Experimental studies showed that the ion beam, circular at the IEG exit, accepted the elliptical form at the distance of 580 mm with half-angle of beam expansion across IEG slits about 2°-3° and close to 0° along them. Thus, the obtained result proved the possibility of creating a new-generation on-board ion injector that could be used in spacecrafts for removal of debris.

  2. Temperature of Heating and Cooling of Massive, Thin, and Wedge-Shaped Plates from Hard-to-Machine Steels During Their Grinding (United States)

    Dement‧ev, V. B.; Ivanova, T. N.; Dolginov, A. M.


    Grinding of flat parts occurs by solid abrasive particles due to the physicomechanical process of deformation and to the action of a process liquid at high temperatures in a zone small in volume and difficult for observation. The rate of heating and cooling depends on the change in the intensity of the heat flux and in the velocity and time of action of the heat source. A study has been made of the regularities of the influence of each of these parameters on the depth and character of structural transformations during the grinding of flat parts from hard-to-machine steels. A procedure to calculate temperature in grinding massive, thin, and wedge-shaped parts has been developed with account taken of the geometric and thermophysical parameters of the tool and the treated part, and also of cutting regimes. The procedure can be used as a constituent part in developing a system for automatic design of the technological process of grinding of flat surfaces. A relationship between the temperature in the grinding zone and the regimes of treatment has been established which makes it possible to control the quality of the surface layer of massive, thin, and wedge-shaped plates from hard-to-machine steels. The rational boundaries of shift of cutting regimes have been determined.

  3. Radio frequency source of a weakly expanding wedge-shaped xenon ion beam for contactless removal of large-sized space debris objects (United States)

    Balashov, Victor; Cherkasova, Maria; Kruglov, Kirill; Kudriavtsev, Arseny; Masherov, Pavel; Mogulkin, Andrey; Obukhov, Vladimir; Riaby, Valentin; Svotina, Victoria


    A theoretical-experimental research has been carried out to determine the characteristics of a radio frequency (RF) ion source for the generation of a weakly expanding wedge-shaped xenon ion beam. Such ion beam geometry is of interest as a prototype of an on-board ion injector for contactless "ion shepherding" by service spacecraft to remove large space debris objects from geostationary orbits. The wedge shape of the ion beam increases its range. The device described herein comprises an inductive gas discharge chamber and a slit-type three-electrode ion extraction grid (IEG) unit. Calculations of accelerating cell geometries and ion trajectories determined the dependence of beam expansion half-angle on normalized perveance based on the measurements of the spatial distributions of the xenon plasma parameters at the IEG entrance for a xenon flow rate q ≈ 0.2 mg/s and an incident RF power Pin ≤ 250 W at a driving frequency f = 2 MHz. Experimental studies showed that the ion beam, circular at the IEG exit, accepted the elliptical form at the distance of 580 mm with half-angle of beam expansion across IEG slits about 2°-3° and close to 0° along them. Thus, the obtained result proved the possibility of creating a new-generation on-board ion injector that could be used in spacecrafts for removal of debris.

  4. Toroidal silicon polarization analyzer for resonant inelastic x-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Xuan [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008-5252 (United States); Key Laboratory of Multi-scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714 (China); Casa, Diego; Kim, Jungho; Gog, Thomas [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Li, Chengyang [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008-5252 (United States); Department of Physics, South University of Science and Technology of China, Shenzhen 518055 (China); Burns, Clement [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008-5252 (United States)


    Resonant Inelastic X-ray Scattering (RIXS) is a powerful probe for studying electronic excitations in materials. Standard high energy RIXS measurements do not measure the polarization of the scattered x-rays, which is unfortunate since it carries information about the nature and symmetry of the excitations involved in the scattering process. Here we report the fabrication of thin Si-based polarization analyzers with a double-concave toroidal surface, useful for L-edge RIXS studies in heavier atoms such as the 5-d transition metals.

  5. Technical note: A new wedge-shaped ionization chamber component module for BEAMnrc to model the integral quality monitoring system® (United States)

    Oderinde, Oluwaseyi Michael; du Plessis, FCP


    The purpose of this study was to develop a new component module (CM) namely IQM to accurately model the integral quality monitoring (IQM) system® to be used in the BEAMnrc Monte Carlo (MC) code. The IQM is essentially a double wedge ionization chamber with the central electrode plate bisecting the wedge. The IQM CM allows the user to characterize the double wedge of this ionization chamber and BEAMnrc can then accurately calculate the dose in this CM including its enclosed air regions. This has been verified against measured data. The newly created CM was added into the standard BEAMnrc CMs, and it will be made available through the NRCC website. The BEAMnrc graphical user interface (GUI) and particle ray-tracing techniques were used to validate the IQM geometry. In subsequent MC simulations, the dose scored in the IQM was verified against measured data over a range of square fields ranging from 1 × 1-30 × 30 cm2. The IQM system is designed for the present day need for a device that could verify beam output in real-time during treatment. This CM is authentic, and it can serve as a basis for researchers that have an interest in real-time beam delivery checking using wedge-shaped ionization chamber based instruments like the IQM.

  6. Exploration of amino acid biomarkers in polar ice with the Mars Organic Analyzer (United States)

    Jayarajah, C.; Botta, O.; Aubrey, A.; Parker, E.; Bada, J.; Mathies, R.


    A portable microfabricated capillary electrophoresis (CE) system named the Mars Organic Analyzer (MOA) has been developed to analyze fluorescently-labeled biomarkers including amino acids, amines, nucleobases, and amino sugars with the goal of life detection on Mars (1,2). This technology has also been shown to be effective in screening the formation of biogenic amines during fermentation (3). The MOA is a part of the Urey instrument package that has been selected for the 2016 European ExoMars mission by ESA. The identification of recent gully erosion sites, observations of ice on and beneath the surface of Mars, and the discovery of large reservoirs of sub-surface ice on Mars point to water-ice as an important target for astrobiological analyses. In addition, the ice samples on the Moon, Mercury, Europa and Enceladus are of interest due to the possibility that they may contain information on biogenic material relevant to the evolution of life. We explore here the use of the MOA instrument for the analysis of amino acids in polar ice samples. The amino acids valine, alanine/serine, glycine, glutamic acid, and aspartic acid were found in the parts-per-billion range from Greenland ice-core samples. Chiral analysis of these samples yielded D/L ratios of 0.51/0.09 for alanine/serine and 0.14/0.06 for aspartic acid. Individual amino acids in the parts-per-trillion range were found in Antarctic ice samples collected from the surface of a meteorite collection area. The distinct amino acid and amine content of these samples indicates that further biomarker characterization of ice samples as a function of sampling location, depth, and structural features will be highly informative. The rapid sensitive analysis capabilities demonstrated here establish the feasibility of using the MOA to analyze the biomarker content of ice samples in planetary exploration. 1. Skelley, A. M.; Scherer, J. R.; Aubrey, A. D.; Grover, W. H.; Ivester, R. H. C., Ehrenfreund, P.; Grunthaner, F. J

  7. Complete polarization analysis of high energy soft x-rays by combining a multilayer phase retarder with crystal analyzer (United States)

    Wang, H.; Dhesi, S. S.; Maccherozzi, F.; Sawhney, K. J. S.


    We demonstrate a complete polarization analysis of soft x-rays with an energy of 1.1 keV using a free-standing W/B4C multilayer phase retarders and a beryl crystal analyzer. The W/B4C multilayer exhibits five times increase in transmission over that previously reported. The beryl crystal proves to be a suitable analyzer for the polarization analysis with a 10% s-component of reflectivity resulting in an extinction ratio close to 0.002 at 1.1 keV. The combination of multilayer phase retarders and crystal analyzers should open up the field of the soft x-ray polarization analysis in the energy range between 1 keV and 2 keV.

  8. Analyzing the Location of the Ion Convection Reversal Boundary in Polar Regions using DMSP Satellite Data (United States)

    Tengdin, P. M.; Emery, B. A.; Maute, A. I.; Knipp, D. J.; Kilcommons, L.


    Measurements from the Defense Meteorological Satellite Program's (DMSP) F13 Satellite were used for a study of convection location in the polar regions of the earth's ionosphere. The satellite was in a sun-synchronous orbit in the dawn-dusk meridian. The data available corresponded to 4 second averages. Using a 20-second smoothing technique, the zero crossings in the ion drift velocity values were determined for each pass of the satellite. OMNI data were used to calculate the average IMF conditions for each pass from 5 minute data with a 10 minute lag to allow the IMF signal to propagate to the ionosphere. This study only considered passes with a Bz southward component where By was smaller than the Bz component. The location of the convection reversal boundary (CRB), or zero crossing in ion drift velocity, was archived for each Bz negative pass. This survey was conducted over the lifetime of the F13 satellite (1995-2009). The Weimer 2005 model was run under the same geophysical conditions in order to compare these models with the satellite observations. Model estimates of the CRB, or the location of the minimum and maximum electric potentials, were considered 'good' if they fell within 2 degrees of the 20-second observations, where 20 seconds corresponds to 1.176 degrees at 850 km. Preliminary results suggest that the model CRBs are 'good' about 65% of the time under Bz negative conditions. The model had a tendency to place the convection reversal boundary too far towards the pole, and showed higher accuracy levels on the dawn side of the earth than on the dusk side.

  9. The γ-Ray Polarization Analyzing Power for the Reaction ^2H(p,γ)^3He at 80-0 keV (United States)

    Wulf, E. A.; Canon, R. S.; Godwin, M. A.; Guillemette, J. F.; Kelley, J. H.; Rice, B. J.; Spraker, M.; Weller, H. R.; Prior, R. M.; Tilley, D. R.


    We are currently investigating the capture reaction ^2H(p, γ)^3He using a polarized beam from the TUNL Polarized Ion Source on a heavy water ice target. The polarization of the 5.5 MeV γ-ray from this reaction is measured with a Compton polarimeter consisting of 5 High Purity Germanium (HPGe) crystals. Measuring the difference in the polarization of the γ-ray for spin-up and spin-down protons gives an analyzing power (A_γ) that is sensitive to meson-exchange currents (MEC). Recent three-body calculations(M. Viviani et al), Phys. Rev. C 54, 534(1996) indicate that the presence of MECs leads to a value of A_γ(15^circ) = A_γ(165^circ) ≈ 0.25 and their absence to A_γ ≈ 0. Preliminary data gives a value of A_γ(90^circ) = -0.1 ± 0.25. An effort to obtain accurate values of A_γ at extreme angles is underway.

  10. Improvements in methods of analyzing dust concentrations, and influence of the storage processes on dust concentrations in polar snow and ice samples

    Directory of Open Access Journals (Sweden)

    Takayuki Miyake


    Full Text Available We sought to improve the analytical methods employed when operating a laser particle counter and to evaluate the influence of the storage processes on dust concentrations in polar snow and ice samples. We corrected the particle size ranges and threshold voltage using the new calibration curve, confirmed the analytical precision and dust concentrations of blank of wipers using in a clean room, and managed any variations in the laser sensor's sensitivity by measuring standard particles. The 15 ml glass screw bottles without packing (liner of cap of bottles yielded the lowest dust concentration of the blank among two types of bottles and nine types of packing for dust analysis. Storage of samples of the Dome Fuji ice core (Antarctica in a refrigerator for 1 year resulted in just a 4% decrease in dust concentration, which is within the analytical precision of the laser particle counter. Storage in a freezer resulted in an increase in dust concentrations and a decrease in the ratio of large particles more than 0.98 μm in particle diameter in the samples, suggesting a change in dust particle size during storage and an influence by the materials of the storage bottles. The addition of dispersants to the Antarctic snow samples is not clearly suitable when analyzing dust concentrations after sample storage by refrigeration or freezing.

  11. Spatial Resolution of a Wedge Shaped MSGC Module

    CERN Document Server

    Bachmann, Sebastian


    A banana shaped closed design MSGC detector module was tested together with silicon detectors and other MSGCs in a 100 GeV muon beam. Despite of an undesirable geometry of the test setup, a spatial resolution below 40 micron m was reached. The efficiency of the module, defined by track reconstruction, shows to be 95,6 percent

  12. Analyzing power measurements of coulomb - nuclear interference with polarized protons at 185-GeV/c and 200-GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Akchurin, Nural [Univ. of Iowa, Iowa City, IA (United States)


    The analysing power AN of proton-proton scattering in the Coulomb-nuclear interference region has been measured using the 185 GeV /c and 200 GeV /c Fermilab polarized proton beams. In the region of 3.0 x 10-3 to 5.0 x 10-2 (GeVIc)2 four-momentum-transfer , squared, the results are found to be consistent with theoretical prediction within statistical unce~tainties.

  13. Inductive dielectric analyzer (United States)

    Agranovich, Daniel; Polygalov, Eugene; Popov, Ivan; Ben Ishai, Paul; Feldman, Yuri


    One of the approaches to bypass the problem of electrode polarization in dielectric measurements is the free electrode method. The advantage of this technique is that, the probing electric field in the material is not supplied by contact electrodes, but rather by electromagnetic induction. We have designed an inductive dielectric analyzer based on a sensor comprising two concentric toroidal coils. In this work, we present an analytic derivation of the relationship between the impedance measured by the sensor and the complex dielectric permittivity of the sample. The obtained relationship was successfully employed to measure the dielectric permittivity and conductivity of various alcohols and aqueous salt solutions.

  14. Polarization Versus Agglomeration


    Martinho, Vítor João Pereira Domingues


    The aim of this paper is to analyze the processes of polarization and agglomeration, to explain the mechanisms and causes of these phenomena in order to identify similarities and differences. As the main implication of this study should be noted that both process pretend to explain the concentration of economic activity and population in certain places, through cumulative phenomena, but with different perspectives, in other words, the polarization with a view of economic development and agglo...

  15. Polarization, political

    NARCIS (Netherlands)

    Wojcieszak, M.; Mazzoleni, G.; Barnhurst, K.G.; Ikeda, K.; Maia, R.C.M.; Wessler, H.


    Polarization has been studied in three different forms: on a social, group, and individual level. This entry first focuses on the undisputed phenomenon of elite polarization (i.e., increasing adherence of policy positions among the elites) and also outlines different approaches to assessing mass

  16. Polarization holography

    DEFF Research Database (Denmark)

    Nikolova, L.; Ramanujam, P.S.

    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...

  17. Polar predictions


    Crame, Alistair; Francis, Jane; Robinson, Stuart; Bowman, Vanessa


    In an effort to improve understanding of faunal evolution and its relationship to climate change, the PALEOPOLAR project is challenging existing theories about the Early Cenozoic era using an integrated, multidisciplinary approach in the polar regions

  18. Bios data analyzer. (United States)

    Sabelli, H; Sugerman, A; Kovacevic, L; Kauffman, L; Carlson-Sabelli, L; Patel, M; Konecki, J


    The Bios Data Analyzer (BDA) is a set of computer programs (CD-ROM, in Sabelli et al., Bios. A Study of Creation, 2005) for new time series analyses that detects and measures creative phenomena, namely diversification, novelty, complexes, nonrandom complexity. We define a process as creative when its time series displays these properties. They are found in heartbeat interval series, the exemplar of bios .just as turbulence is the exemplar of chaos, in many other empirical series (galactic distributions, meteorological, economic and physiological series), in biotic series generated mathematically by the bipolar feedback, and in stochastic noise, but not in chaotic attractors. Differencing, consecutive recurrence and partial autocorrelation indicate nonrandom causation, thereby distinguishing chaos and bios from random and random walk. Embedding plots distinguish causal creative processes (e.g. bios) that include both simple and complex components of variation from stochastic processes (e.g. Brownian noise) that include only complex components, and from chaotic processes that decay from order to randomness as the number of dimensions is increased. Varying bin and dimensionality show that entropy measures symmetry and variety, and that complexity is associated with asymmetry. Trigonometric transformations measure coexisting opposites in time series and demonstrate bipolar, partial, and uncorrelated opposites in empirical processes and bios, supporting the hypothesis that bios is generated by bipolar feedback, a concept which is at variance with standard concepts of polar and complementary opposites.

  19. Shock Initiation of Wedge-shaped Explosive Measured with Smear Camera and Photon Doppler Velocimetry (United States)

    Gu, Yan


    Triaminotrinitrobenzene (TATB) is an important insensitive high explosive in conventional weapons due to its safety and high energy. In order to have an insight into the shock initiation performance of a TATB-based insensitive high explosive (IHE), experimental measurements of the particle velocity histories of the TATB-based Explosive using Photon Doppler Velocimetry and shock wave profile of the TATB-based explosive using High Speed Rotating Mirror Smear Camera had been performed. In this paper, we would describe the shock initiation performance of the TATB-based explosive by run-to-detonation distance and the particle velocity history at an initialization shock of about 7.9 GPa. The parameters of hugoniot of unreacted the TATB-based explosive and Pop relationship could be derived with the particle velocity history obtained in this paper.

  20. Polar Stratigraphy (United States)


    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.

  1. Wideband selective polarization conversion mediated by three-dimensional metamaterials (United States)

    Li, Yongfeng; Zhang, Jieqiu; Qu, Shaobo; Wang, Jiafu; Chen, Hongya; Xu, Zhuo; Zhang, Anxue


    In this paper, we proposed to use ultra-thin 3D metamaterials to manipulate the polarization of the transmitted electromagnetic waves. As an example, we designed a 3D metamaterial to serve as an ultra-thin linear-polarization converter, which overcomes the defects of bulky volume and narrow bandwidth of conventional polarization converters. Polarization selectivity and polarization convertibility are achieved simultaneously in the single-layer metamaterial. The physical mechanism is analyzed using reflection matrix and transmission matrix in details. Simulated cross-polarization and co-polarization conversions for TE and TM incident waves verify the polarization selectivity and polarization convertibility.

  2. Polar Codes (United States)


    added by the decoder is K/ρ+Td. By the last assumption, Td and Te are both ≤ K/ρ, so the total latency added is between 2K/ρ and 4K /ρ. For example...better resolution near the decision point. Reference [12] showed that in decoding a (1024, 512) polar code, using 6-bit LLRs resulted in per- formance

  3. Polar Unconformity (United States)


    [figure removed for brevity, see original site] Figure 1 19 August 2004 The arrows (see Figure 1) in this July 2004 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image indicate the location of an unconformity in the layered sequence of the martian north polar cap. An unconformity is a geologic term that indicates a break in the depositional record of a sedimentary deposit. In this case, the change is recorded by the presence of a series of polar layers that are truncated (cut off) along the line of arrows. The erosion that cut these layers along a gentle slope were later covered by a new set of layers that occur from the arrow tips upward to the top of the sequence shown here. The image is located near 85.2oN, 7.3oW. The bright features in the lower third of the image are frost-covered sand dunes. The image covers an area about 3 km (1.9 mi) across and sunlight illuminates the scene from the top/upper right.

  4. Soft Decision Analyzer (United States)

    Steele, Glen; Lansdowne, Chatwin; Zucha, Joan; Schlensinger, Adam


    The Soft Decision Analyzer (SDA) is an instrument that combines hardware, firmware, and software to perform realtime closed-loop end-to-end statistical analysis of single- or dual- channel serial digital RF communications systems operating in very low signal-to-noise conditions. As an innovation, the unique SDA capabilities allow it to perform analysis of situations where the receiving communication system slips bits due to low signal-to-noise conditions or experiences constellation rotations resulting in channel polarity in versions or channel assignment swaps. SDA s closed-loop detection allows it to instrument a live system and correlate observations with frame, codeword, and packet losses, as well as Quality of Service (QoS) and Quality of Experience (QoE) events. The SDA s abilities are not confined to performing analysis in low signal-to-noise conditions. Its analysis provides in-depth insight of a communication system s receiver performance in a variety of operating conditions. The SDA incorporates two techniques for identifying slips. The first is an examination of content of the received data stream s relation to the transmitted data content and the second is a direct examination of the receiver s recovered clock signals relative to a reference. Both techniques provide benefits in different ways and allow the communication engineer evaluating test results increased confidence and understanding of receiver performance. Direct examination of data contents is performed by two different data techniques, power correlation or a modified Massey correlation, and can be applied to soft decision data widths 1 to 12 bits wide over a correlation depth ranging from 16 to 512 samples. The SDA detects receiver bit slips within a 4 bits window and can handle systems with up to four quadrants (QPSK, SQPSK, and BPSK systems). The SDA continuously monitors correlation results to characterize slips and quadrant change and is capable of performing analysis even when the

  5. Terahertz broadband polarization converter based on metamaterials (United States)

    Li, Yonghua; Zhao, Guozhong


    Based on the metamaterial composed of symmetrical split resonant ring, a broadband reflective terahertz polarization converter is proposed. The numerical simulation shows that it can rotate the polarization direction of linear polarized wave 90° in the range of 0.7-1.8THz and the polarization conversion ratio is over 90%. The reflection coefficient of the two electric field components in the diagonal direction is the same and the phase difference is 180° ,which leads to the cross-polarization rotation.In order to further study the physical mechanism of high polarization conversion, we analyze the surface current distribution of the resonant ring. The polarization converter has potential applications in terahertz wave plate and metamaterial antenna design.

  6. Advancements on Radar Polarization Information Acquisition and Processing

    Directory of Open Access Journals (Sweden)

    Dai Dahai


    Full Text Available The study on radar polarization information acquisition and processing has currently been one important part of radar techniques. The development of the polarization theory is simply reviewed firstly. Subsequently, some key techniques which include polarization measurement, polarization anti-jamming, polarization recognition, imaging and parameters inversion using radar polarimetry are emphatically analyzed in this paper. The basic theories, the present states and the development trends of these key techniques are presented and some meaningful conclusions are derived.

  7. Polarized electron sources

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  8. Inclusive quasielastic scattering of polarized electrons from polarized nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Amaro, J.E. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Center for Theoretical Physics]|[Universidad de Granada (Spain). Dept. de Fisica Moderna]|[Massachusetts Inst. of Tech., Cambridge, MA (United States). Lab. for Nuclear Science]|[Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Physics; Caballero, J.A. [Consejo Superior de Investigaciones Cientificas (CSIC), Madrid (Spain). Inst. de Estructura de la Materia]|[Sevilla Univ. (Spain). Dept. de Fisica Atomica, Molecular y Nuclear; Donnelly, T.W. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Center for Theoretical Physics]|[Massachusetts Inst. of Tech., Cambridge, MA (United States). Lab. for Nuclear Science]|[Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Physics; Moya de Guerra, E. [Consejo Superior de Investigaciones Cientificas (CSIC), Madrid (Spain). Inst. de Estructura de la Materia


    The inclusive quasielastic response functions that appear in the scattering of polarized electrons from polarized nuclei are computed and analyzed for several closed-shell-minus-one nuclei with special attention paid to {sup 39}K. Results are presented using two models for the ejected nucleon - when described by a distorted wave in the continuum shell model or by a plane wave in PWIA with on- and off-shell nucleons. Relativistic effects in kinematics and in the electromagnetic current have been incorporated throughout. Specifically, the recently obtained expansion of the electromagnetic current in powers only of the struck nucleon`s momentum is employed for the on-shell current and the effects of the first-order terms (spin-orbit and convection) are compared with the zeroth-order (charge and magnetization) contributions. The use of polarized inclusive quasielastic electron scattering as a tool for determining near-valence nucleon momentum distributions is discussed. (orig.).

  9. DOG optical gas analyzers

    Energy Technology Data Exchange (ETDEWEB)

    Azbukin, A.A.; Buldakov, M.A.; Korolev, B.V.; Korolo' kov, V.A.; Matrosov, I.I. [Siberian Branch of the Russian Academy of Sciences, Tomsk (Russian Federation). Inst. of Optical Monitoring


    Stationary gas analyzers for continuous monitoring of sulfur and nitrogen oxides in exhaust gases of electric power plants burning fossil fuels have been developed. The DOG series of gas-analyzers use non-laser UV radiation sources and the differential absorption lidar (DIAL) measurement technique. Operation of the gas-analyzers at Russian electric power plants showed their high efficiency, reliability, and easiness in operation at lower cost as compared to similar foreign devices. 8 refs., 3 figs., 1 tab.

  10. Universal MOSFET parameter analyzer (United States)

    Klekachev, A. V.; Kuznetsov, S. N.; Pikulev, V. B.; Gurtov, V. A.


    MOSFET analyzer is developed to extract most important parameters of transistors. Instead of routine DC transfer and output characteristics, analyzer provides an evaluation of interface states density by applying charge pumping technique. There are two features that outperform the analyzer among similar products of other vendors. It is compact (100 × 80 × 50 mm 3 in dimensions) and lightweight (instrument with ultra low power supply (instrument was designed on the base of component parts from CYPRESS and ANALOG DEVICES (USA).

  11. Polarized IR microscopic imaging of articular cartilage

    Energy Technology Data Exchange (ETDEWEB)

    Ramakrishnan, Nagarajan; Xia Yang; Bidthanapally, Aruna [Department of Physics and Center for Biomedical Research, Oakland University, Rochester, MI 48309 (United States)


    The objective of this spectroscopic imaging study is to understand the anisotropic behavior of articular cartilage under polarized infrared radiation at 6.25 {mu}m pixel resolution. Paraffin embedded canine humeral cartilage-bone blocks were used to obtain 6 {mu}m thick tissue sections. Two wire grid polarizers were used to manipulate the polarization states of IR radiation by setting them for various polarizer/analyzer angles. The characteristics of the major chemical components (amide I, amide II, amide III and sugar) of articular cartilage were investigated using (a) a polarizer and (b) a combination of a polarizer and an analyzer. These results were compared to those obtained using only an analyzer. The infrared anisotropy (variation in infrared absorption as a function of polarization angles) of amide I, amide II and amide III bands correlates with the orientation of collagen fibrils along the tissue depth in different histological zones. An 'anisotropic flipping' region of amide profiles indicates the possibility of using Fourier transform infrared imaging (FTIRI) to determine the histological zones in cartilage. Cross-polarization experiment indicates the resolution of overlapping peaks of collagen triple helix and/or proteoglycan in articular cartilage.

  12. Analyzing Peace Pedagogies (United States)

    Haavelsrud, Magnus; Stenberg, Oddbjorn


    Eleven articles on peace education published in the first volume of the Journal of Peace Education are analyzed. This selection comprises peace education programs that have been planned or carried out in different contexts. In analyzing peace pedagogies as proposed in the 11 contributions, we have chosen network analysis as our method--enabling…

  13. Gearbox vibration diagnostic analyzer (United States)


    This report describes the Gearbox Vibration Diagnostic Analyzer installed in the NASA Lewis Research Center's 500 HP Helicopter Transmission Test Stand to monitor gearbox testing. The vibration of the gearbox is analyzed using diagnostic algorithms to calculate a parameter indicating damaged components.

  14. Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from underway - surface observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from the USCGC POLAR STAR in the Coral Sea, North Pacific Ocean and others from 2001-11-02 to 2002-04-23 (NODC Accession 0108234) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0108234 includes chemical, meteorological, physical and underway - surface data collected from USCGC POLAR STAR in the Coral Sea, North Pacific Ocean,...

  15. Development of polarized {sup 3}He filter for polarized neutron experiment

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, K.; Sato, H.; Yoshimi, A.; Asahi, K. [Tokyo Inst. of Tech. (Japan). Faculty of Science; Masuda, Y.; Muto, S.; Ishimoto, S.; Morimoto, K.


    A high-pressure polarized {sup 3}He gas cell, pumped with two diode lasers, has been developed at KEK for use as a polarizer and a spin analyzer for low energy neutrons. The polarization attained of {sup 3}He was determined through the measurement of the transmission of the unpolarized neutrons through the {sup 3}He cell. So far we obtained P{sub He}=18% at 10 atm and P{sub He}=12% at 20 atm. (author)

  16. Analyzing in the present

    DEFF Research Database (Denmark)

    Revsbæk, Line; Tanggaard, Lene


    The article presents a notion of “analyzing in the present” as a source of inspiration in analyzing qualitative research materials. The term emerged from extensive listening to interview recordings during everyday commuting to university campus. Paying attention to the way different parts...... of various interviews conveyed diverse significance to the listening researcher at different times became a method of continuously opening up the empirical material in a reflexive, breakdown-oriented process of analysis. We argue that situating analysis in the present of analyzing emphasizes and acknowledges...

  17. RHIC FY15 pp Run RHIC and AGS polarization analysis

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Adams, P. [Brookhaven National Lab. (BNL), Upton, NY (United States)


    The polarization information is important for the spin physics program in Relativistic Heavy Ion Collider (RHIC). There are discrepancies between AGS and RHIC polarization measurements. First, the face value of AGS polarization is higher than RHIC ones in general. Second, the measured polarization profile (described by the profile ratio R) is stronger in AGS than in RHIC. This note analyzes the polarization data from FY15 pp run period. The results show that the differences between AGS and RHIC polarization measurements are reasonable, but the R value difference is puzzling. The difference between blue and yellow ring is worth of spin simulation to explain.

  18. Geographical Income Polarization

    DEFF Research Database (Denmark)

    Azhar, Hussain; Jonassen, Anders Bruun

    In this paper we estimate the degree, composition and development of geographical income polarization based on data at the individual and municipal level in Denmark from 1984 to 2002. Rising income polarization is reconfirmed when applying new polarization measures, the driving force being greater...... 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...

  19. Software Design Analyzer System (United States)

    Tausworthe, R. C.


    CRISP80 software design analyzer system a set of programs that supports top-down, hierarchic, modular structured design, and programing methodologies. CRISP80 allows for expression of design as picture of program.

  20. Miniature mass analyzer

    CERN Document Server

    Cuna, C; Lupsa, N; Cuna, S; Tuzson, B


    The paper presents the concept of different mass analyzers that were specifically designed as small dimension instruments able to detect with great sensitivity and accuracy the main environmental pollutants. The mass spectrometers are very suited instrument for chemical and isotopic analysis, needed in environmental surveillance. Usually, this is done by sampling the soil, air or water followed by laboratory analysis. To avoid drawbacks caused by sample alteration during the sampling process and transport, the 'in situ' analysis is preferred. Theoretically, any type of mass analyzer can be miniaturized, but some are more appropriate than others. Quadrupole mass filter and trap, magnetic sector, time-of-flight and ion cyclotron mass analyzers can be successfully shrunk, for each of them some performances being sacrificed but we must know which parameters are necessary to be kept unchanged. To satisfy the miniaturization criteria of the analyzer, it is necessary to use asymmetrical geometries, with ion beam obl...

  1. Intrinsically polarized elastic metamaterial (United States)

    Bilal, Osama; Suesstrunk, Roman; Huber, Sebastian; Daraio, Chiara

    Mechanical metamaterials, with periodically repeating basic building blocks in space, expand the envelope of possible properties of matter. Metamaterials harness their effective properties through structure rather than chemical composition. Successful implementations of such materials enabled the realization of ultrastiff-utralight materials, negative Poisson ratio materials, and fluid-like solids. In this work, we theoretically analyze and experimentally implement a new design principle for mechanical metamaterials. By combining states of self-stress, topological invariants and additive manufacturing techniques, we realize a new class of three-dimensional mechanical metamaterials with polar elasticity. The fabricated specimens show, at two of its opposing faces along the same axis, an asymmetric elastic response (i.e., soft on one face and harder on the other). We design our lattice to retain angular dependency to a perpendicular load, providing a direct experimental observation of nodal Weyl lines.

  2. Jones matrix treatment for optical Fourier processors with structured polarization. (United States)

    Moreno, Ignacio; Iemmi, Claudio; Campos, Juan; Yzuel, Maria J


    We present a Jones matrix method useful to analyze coherent optical Fourier processors employing structured polarization. The proposed method is a generalization of the standard classical optical Fourier transform processor, but considering vectorial spatial functions with two complex components corresponding to two orthogonal linear polarizations. As a result we derive a Jones matrix that describes the polarization output in terms of two vectorial functions defining respectively the structured polarization input and the generalized polarization impulse response. We apply the method to show and analyze an experiment in which a regular scalar diffraction grating is converted into equivalent polarization diffraction gratings by means of an appropriate polarization filtering. The technique is further demonstrated to generate arbitrary structured polarizations. Excellent experimental results are presented.

  3. Development of dendrite polarity in Drosophila neurons

    Directory of Open Access Journals (Sweden)

    Hill Sarah E


    Full Text Available Abstract Background Drosophila neurons have dendrites that contain minus-end-out microtubules. This microtubule arrangement is different from that of cultured mammalian neurons, which have mixed polarity microtubules in dendrites. Results To determine whether Drosophila and mammalian dendrites have a common microtubule organization during development, we analyzed microtubule polarity in Drosophila dendritic arborization neuron dendrites at different stages of outgrowth from the cell body in vivo. As dendrites initially extended, they contained mixed polarity microtubules, like mammalian neurons developing in culture. Over a period of several days this mixed microtubule array gradually matured to a minus-end-out array. To determine whether features characteristic of dendrites were localized before uniform polarity was attained, we analyzed dendritic markers as dendrites developed. In all cases the markers took on their characteristic distribution while dendrites had mixed polarity. An axonal marker was also quite well excluded from dendrites throughout development, although this was perhaps more efficient in mature neurons. To confirm that dendrite character could be acquired in Drosophila while microtubules were mixed, we genetically disrupted uniform dendritic microtubule organization. Dendritic markers also localized correctly in this case. Conclusions We conclude that developing Drosophila dendrites initially have mixed microtubule polarity. Over time they mature to uniform microtubule polarity. Dendrite identity is established before the mature microtubule arrangement is attained, during the period of mixed microtubule polarity.

  4. System for transmitting and receiving multi-polarized signals

    DEFF Research Database (Denmark)


    The present disclosure relates to: an optical receiver, configured to receive at least three multiplexed, differently polarized, optically transmitted signals, each signal associated with a predefined state of polarization, said receiver comprising a multi- polarization analyzer for obtaining...... an analyzed signal for each of said polarized signals, wherein at least one of said analyzed signals comprises data in the full Stokes space; an optical transmitter, configured to transmit at least three multiplexed, differently polarized, optically transmitted signals, wherein at least one of said polarized...... signals comprises data in the full Stokes space; a system configured to communicate optically over a communication link, comprising: an optical transmitter, configured to generate and multiplex at least three independent data signals having different states of polarization into a multiplexed signal...

  5. Graphing Polar Curves (United States)

    Lawes, Jonathan F.


    Graphing polar curves typically involves a combination of three traditional techniques, all of which can be time-consuming and tedious. However, an alternative method--graphing the polar function on a rectangular plane--simplifies graphing, increases student understanding of the polar coordinate system, and reinforces graphing techniques learned…

  6. Polarization extinction ratio and polarization dependent intensity noise in long-pulse supercontinuum generation (Conference Presentation)

    DEFF Research Database (Denmark)

    Chin, Catherine; Engelsholm, Rasmus Dybbro; Moselund, Peter Morten


    polarization extinction ratios (PER) of over 10 dB. We experimentally demonstrate how the spectrally resolved polarization develops with increasing power and along the length of the nonlinear fiber. The experimental results are compared to numerical simulations of coupled polarization states mimicking...... the experimental conditions. Subsequently, a single-shot pulse-to-pulse polarization dependent relative intensity noise (PD-RIN) was measured and the noise characteristics were analyzed using long-tailed and rogue wave statistics. To do this, we used a range of 10 nm narrow bandpass filters (BPF) between 550 nm...

  7. Americal options analyzed differently

    NARCIS (Netherlands)

    Nieuwenhuis, J.W.


    In this note we analyze in a discrete-time context and with a finite outcome space American options starting with the idea that every tradable should be a martingale under a certain measure. We believe that in this way American options become more understandable to people with a good working

  8. Analyzing Stereotypes in Media. (United States)

    Baker, Jackie


    A high school film teacher studied how students recognized messages in film, examining how film education could help students identify and analyze racial and gender stereotypes. Comparison of students' attitudes before and after the film course found that the course was successful in raising students' consciousness. (SM)

  9. Detecting Social Polarization and Radicalization

    DEFF Research Database (Denmark)

    Qureshi, Pir Abdul Rasool; Memon, Nasrullah; Wiil, Uffe Kock


    This paper proposes a novel system to detect social polarization and to estimate the chances of violent radicalization associated with it. The required processes for such a system are indicated; it is also analyzed how existing technologies can be integrated into the proposed system to fulfill...... the objectives. We propose a scalable design to enable integration and extension of future state of the art technologies into the system....


    Directory of Open Access Journals (Sweden)

    B. Yang


    Full Text Available China's long-term planning major projects "high-resolution earth observation system" has been invested nearly 100 billion and the satellites will reach 100 to 2020. As to 2/3 of China's area covered by mountains,it has a higher demand for remote sensing. In addition to light intensity, frequency, phase, polarization is also the main physical characteristics of remote sensing electromagnetic waves. Polarization is an important component of the reflected information from the surface and the atmospheric information, and the polarization effect of the ground object reflection is the basis of the observation of polarization remote sensing. Therefore, the effect of eliminating the polarization effect is very important for remote sensing applications. The main innovations of this paper is as follows: (1 Remote sensing observation method. It is theoretically deduced and verified that the polarization can weaken the light in the strong light region, and then provide the polarization effective information. In turn, the polarization in the low light region can strengthen the weak light, the same can be obtained polarization effective information. (2 Polarization effect of vegetation. By analyzing the structure characteristics of vegetation, polarization information is obtained, then the vegetation structure information directly affects the absorption of biochemical components of leaves. (3 Atmospheric polarization neutral point observation method. It is proved to be effective to achieve the ground-gas separation, which can achieve the effect of eliminating the atmospheric polarization effect and enhancing the polarization effect of the object.

  11. Polarization Remote Sensing Physical Mechanism, Key Methods and Application (United States)

    Yang, B.; Wu, T.; Chen, W.; Li, Y.; Knjazihhin, J.; Asundi, A.; Yan, L.


    China's long-term planning major projects "high-resolution earth observation system" has been invested nearly 100 billion and the satellites will reach 100 to 2020. As to 2/3 of China's area covered by mountains it has a higher demand for remote sensing. In addition to light intensity, frequency, phase, polarization is also the main physical characteristics of remote sensing electromagnetic waves. Polarization is an important component of the reflected information from the surface and the atmospheric information, and the polarization effect of the ground object reflection is the basis of the observation of polarization remote sensing. Therefore, the effect of eliminating the polarization effect is very important for remote sensing applications. The main innovations of this paper is as follows: (1) Remote sensing observation method. It is theoretically deduced and verified that the polarization can weaken the light in the strong light region, and then provide the polarization effective information. In turn, the polarization in the low light region can strengthen the weak light, the same can be obtained polarization effective information. (2) Polarization effect of vegetation. By analyzing the structure characteristics of vegetation, polarization information is obtained, then the vegetation structure information directly affects the absorption of biochemical components of leaves. (3) Atmospheric polarization neutral point observation method. It is proved to be effective to achieve the ground-gas separation, which can achieve the effect of eliminating the atmospheric polarization effect and enhancing the polarization effect of the object.

  12. Ocular Response Analyzer


    Kaushik, Sushmita; Pandav, Surinder Singh


    Until recently, corneal biomechanical properties could not be measured in vivo. The ocular response analyzer is a new, noninvasive device that analyses corneal biomechanical properties simply and rapidly. The ORA allows cornea compensated IOP measurements and can estimate corneal hysteresis (CH) and corneal resistance factor (CRF). It is designed to improve the accuracy of IOP measurement by using corneal biomechanical data to calculate a biomechanically adjusted estimate of intraocular press...

  13. Analyzing sustainable competitive advantage


    Abdul Malek Nurul Aida; Shahzad Khuram; Takala Josu; Bojnec Stefan; Papler Drago; Liu Yang


    In today’s dynamic business environment, a key challenge for all companies is to make adaptive adjustments to their manufacturing strategy. This study demonstrates the competitive priorities of manufacturing strategy in hydro-power case company to evaluate the level of sustainable competitive advantage and also to further analyze how business strategies are aligned with manufacturing strategies. This research is based on new holistic analytical evaluation of manufacturing strategy index, sens...

  14. Polarization effects. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Courant, E.


    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.

  15. Classifying lipoproteins based on their polar profiles. (United States)

    Polanco, Carlos; Castañón-González, Jorge Alberto; Buhse, Thomas; Uversky, Vladimir N; Amkie, Rafael Zonana


    The lipoproteins are an important group of cargo proteins known for their unique capability to transport lipids. By applying the Polarity index algorithm, which has a metric that only considers the polar profile of the linear sequences of the lipoprotein group, we obtained an analytical and structural differentiation of all the lipoproteins found in UniProt Database. Also, the functional groups of lipoproteins, and particularly of the set of lipoproteins relevant to atherosclerosis, were analyzed with the same method to reveal their structural preference, and the results of Polarity index analysis were verified by an alternate test, the Cumulative Distribution Function algorithm, applied to the same groups of lipoproteins.

  16. Layered magnets: polarized neutron reflection studies

    Energy Technology Data Exchange (ETDEWEB)

    Zabel, H.; Schreyer, A. [Ruhr-Univ. Bochum, Lehrstuhl fuer Experimentalphysik/Festkoerperphysik, Bochum (Germany)


    Neutron reflectivity measurements from extended surfaces, thin films and superlattices provide information on the chemical profile parallel to the film normal, including film thicknesses, average composition and interfacial roughness parameters. Reflectivity measurements with polarized neutrons are particularly powerful for analyzing the magnetic density profiles in thin films and superlattices in addition to chemical profiles. The basic theory of polarized neutron reflectivity is provided, followed by some examples and more recent applications concerning polarized neutron reflectivity studies from exchange coupled Fe/Cr superlattices. (author) 5 figs., 13 refs.

  17. Semantic-enabled Spatiotemporal Web Portal for Polar Sciences (United States)

    Liu, K.


    It is essential for Intergovernmental and scientists to study, monitor and analyze the geographic data in polar regions. Polarregions are likely to respond rapidly and more severely to the climate changesthan any other area on the Earth.They also have significant importance for Global warming research. The ocean water around the Antarctic and Arctic is a crucial part of the ocean's thermohaline circulation. The Polar Cyberinfrastructure Program was built to acquire, share, access, analyze the polar data for Arctic and Antarctic communities. The polar data are becoming big and bring challenges for Polar Cyberinfrastructure Program including: 1) it is difficultfor polar data users to discover most relevant data based on the understanding the behavior; 2) the quality of polar data service is essential to use the polar data, however, it varies for users in different locations and different time. The semantic enabled discovery and volunteer computing are used in the Polar Cyberinfrastructurefor tackling these challenges: 1) semantic search and knowledge reasoning to improve the discovery recall and precision of polar data; 2) volunteer computing is used to gather volunteers computing resources around the world to improve the quality evaluationaccuracy of polar data service. Keywords: Polar Science, Cyberinfrastructure, Semantic, Volunteer Computing

  18. Field Deployable DNA analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Wheeler, E; Christian, A; Marion, J; Sorensen, K; Arroyo, E; Vrankovich, G; Hara, C; Nguyen, C


    This report details the feasibility of a field deployable DNA analyzer. Steps for swabbing cells from surfaces and extracting DNA in an automatable way are presented. Since enzymatic amplification reactions are highly sensitive to environmental contamination, sample preparation is a crucial step to make an autonomous deployable instrument. We perform sample clean up and concentration in a flow through packed bed. For small initial samples, whole genome amplification is performed in the packed bed resulting in enough product for subsequent PCR amplification. In addition to DNA, which can be used to identify a subject, protein is also left behind, the analysis of which can be used to determine exposure to certain substances, such as radionuclides. Our preparative step for DNA analysis left behind the protein complement as a waste stream; we determined to learn if the proteins themselves could be analyzed in a fieldable device. We successfully developed a two-step lateral flow assay for protein analysis and demonstrate a proof of principle assay.

  19. Ring Image Analyzer (United States)

    Strekalov, Dmitry V.


    Ring Image Analyzer software analyzes images to recognize elliptical patterns. It determines the ellipse parameters (axes ratio, centroid coordinate, tilt angle). The program attempts to recognize elliptical fringes (e.g., Newton Rings) on a photograph and determine their centroid position, the short-to-long-axis ratio, and the angle of rotation of the long axis relative to the horizontal direction on the photograph. These capabilities are important in interferometric imaging and control of surfaces. In particular, this program has been developed and applied for determining the rim shape of precision-machined optical whispering gallery mode resonators. The program relies on a unique image recognition algorithm aimed at recognizing elliptical shapes, but can be easily adapted to other geometric shapes. It is robust against non-elliptical details of the image and against noise. Interferometric analysis of precision-machined surfaces remains an important technological instrument in hardware development and quality analysis. This software automates and increases the accuracy of this technique. The software has been developed for the needs of an R&TD-funded project and has become an important asset for the future research proposal to NASA as well as other agencies.

  20. Chemical characterization by GC-MS and phytotoxic potential of non-polar and polar fractions of seeds of Dioteryx odorata (Aubl.) Willd. from Venezuelan regions


    Oliveros-Bastidas,Alberto de J.; Demuner, Antonio J.; Luiz Claudio Almeida Barbosa


    Dipteryx odorata (Aubl.) Willd. is a tall arboreal species native to Central and Northern South America. This paper describes the chemical characterization and phytotoxic potential of polar and non-polar extracts from D. odorata seeds. Structural determinations were accomplished by chemical derivatization and analyzed by GC/MS. The chemical composition of the non-polar fraction (hexane and dichloromethane) presented fatty acids as major constituent. Medium polar and polar fractions (ethyl ace...

  1. Data processing workflow for time of flight polarized neutrons inelastic measurements

    Energy Technology Data Exchange (ETDEWEB)

    Savici, Andrei T [ORNL; Zaliznyak, Igor [Brookhaven National Laboratory (BNL); Garlea, Vasile O [ORNL; Winn, Barry L [ORNL


    We discuss the data processing workflow for polarized neutron scattering measurements performed at HYSPEC spectrometer at the Spallation Neutron Source, Oak Ridge National Laboratory. The effects of the focusing Heusler crystal polarizer and the wide-angle supermirror transmission polarization analyzer are added to the data processing flow of the non-polarized case. The implementation is done using the Mantid software package.

  2. Trace impurity analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, W.J.; Edwards, D. Jr.


    The desirability for long-term reliability of large scale helium refrigerator systems used on superconducting accelerator magnets has necessitated detection of impurities to levels of a few ppM. An analyzer that measures trace impurity levels of condensable contaminants in concentrations of less than a ppM in 15 atm of He is described. The instrument makes use of the desorption temperature at an indicated pressure of the various impurities to determine the type of contaminant. The pressure rise at that temperature yields a measure of the contaminant level of the impurity. A LN/sub 2/ cryogenic charcoal trap is also employed to measure air impurities (nitrogen and oxygen) to obtain the full range of contaminant possibilities. The results of this detector which will be in use on the research and development helium refrigerator of the ISABELLE First-Cell is described.

  3. Analyzing complicity in risk. (United States)

    Busby, Jerry


    When risks generate anger rather than fear, there is at least someone who regards the imposition of those risks as wrongdoing; and it then makes sense to speak of the involvement in producing those risks as complicity. It is particularly relevant to examine the complicity of risk bearers, because this is likely to have a strong influence on how far other actors should go in providing them with protection. This article makes a case for analyzing complicity explicitly, in parallel with normal processes of risk assessment, and proposes a framework for this analysis. It shows how it can be applied in a case study of maritime transportation, and examines the practical and theoretical difficulties of this kind of analysis. The conclusion is that the analysis has to be formative rather than summative, but that it could provide a useful way of exposing differences in the assumptions of different actors about agency and responsibility.

  4. PhosphoSiteAnalyzer

    DEFF Research Database (Denmark)

    Bennetzen, Martin V; Cox, Jürgen; Mann, Matthias


    Phosphoproteomic experiments are routinely conducted in laboratories worldwide, and because of the fast development of mass spectrometric techniques and efficient phosphopeptide enrichment methods, researchers frequently end up having lists with tens of thousands of phosphorylation sites...... for further interrogation. To answer biologically relevant questions from these complex data sets, it becomes essential to apply computational, statistical, and predictive analytical methods. Here we provide an advanced bioinformatic platform termed "PhosphoSiteAnalyzer" to explore large phosphoproteomic data...... an algorithm to retrieve kinase predictions from the public NetworKIN webpage in a semiautomated way and applies hereafter advanced statistics to facilitate a user-tailored in-depth analysis of the phosphoproteomic data sets. The interface of the software provides a high degree of analytical flexibility...

  5. System performance analyzer (United States)

    Helbig, H. R.


    The System Performance Analyzer (SPA) designed to provide accurate real time information about the operation of complex systems and developed for use on the Airborne Data Analysis/Monitor System (ADAMS), a ROLM 1666 based system is described. The system uses an external processor to operate an intelligent, simulated control panel. Also provided are functions to trace operations, determine frequency of use of memory areas, and time or count user tasks in a multitask environment. This augments the information available from the standard debugger and control panel, and reduces the time and effort needed by ROLM 1666 users in optimizing their system, as well as providing documentation of the effect of any changes. The operation and state of the system are evaluated.

  6. PDA: Pooled DNA analyzer

    Directory of Open Access Journals (Sweden)

    Lin Chin-Yu


    Full Text Available Abstract Background Association mapping using abundant single nucleotide polymorphisms is a powerful tool for identifying disease susceptibility genes for complex traits and exploring possible genetic diversity. Genotyping large numbers of SNPs individually is performed routinely but is cost prohibitive for large-scale genetic studies. DNA pooling is a reliable and cost-saving alternative genotyping method. However, no software has been developed for complete pooled-DNA analyses, including data standardization, allele frequency estimation, and single/multipoint DNA pooling association tests. This motivated the development of the software, 'PDA' (Pooled DNA Analyzer, to analyze pooled DNA data. Results We develop the software, PDA, for the analysis of pooled-DNA data. PDA is originally implemented with the MATLAB® language, but it can also be executed on a Windows system without installing the MATLAB®. PDA provides estimates of the coefficient of preferential amplification and allele frequency. PDA considers an extended single-point association test, which can compare allele frequencies between two DNA pools constructed under different experimental conditions. Moreover, PDA also provides novel chromosome-wide multipoint association tests based on p-value combinations and a sliding-window concept. This new multipoint testing procedure overcomes a computational bottleneck of conventional haplotype-oriented multipoint methods in DNA pooling analyses and can handle data sets having a large pool size and/or large numbers of polymorphic markers. All of the PDA functions are illustrated in the four bona fide examples. Conclusion PDA is simple to operate and does not require that users have a strong statistical background. The software is available at

  7. Interference of wedge-shaped protrusions on the faces of a Griffith crack in biaxial stress. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Boulet, J.A.M. [Tennessee Univ., Knoxville, TN (United States)


    An initial investigation of the influence of protrusion interference on the fracture toughness required to prevent unstable propagation of a Griffith crack in a brittle material is described. The interference is caused by relative shear displacement of the crack faces when subjected to remote biaxial stress with neither principal stress parallel to the crack. It is shown that for room temperature cracks smaller than about one centimeter in silicon carbide, or about one millimeter in silicon nitride, the presence of interference changes the fracture stress. A mathematical model based on linear elasticity solutions and including multiple interference sites at arbitrarily specified positions on the crack is presented. Computations of the change in required fracture toughness and its dependence on wedge geometry (size and vertex angle), applied stresses (orientation and magnitude), and location of the interference site are discussed. Results indicate that a single interference site has only a slight effect on required toughness. However, the influence of interference increases monotonically with the number of interference sites. The two-dimensional model described herein is not accurate when the interference sites are closely spaced.

  8. [Review] Polarization and Polarimetry (United States)

    Trippe, Sascha


    Polarization is a basic property of light and is fundamentally linked to the internal geometry of a source of radiation. Polarimetry complements photometric, spectroscopic, and imaging analyses of sources of radiation and has made possible multiple astrophysical discoveries. In this article I review (i) the physical basics of polarization: electromagnetic waves, photons, and parameterizations; (ii) astrophysical sources of polarization: scattering, synchrotron radiation, active media, and the Zeeman, Goldreich-Kylafis, and Hanle effects, as well as interactions between polarization and matter (like birefringence, Faraday rotation, or the Chandrasekhar-Fermi effect); (iii) observational methodology: on-sky geometry, influence of atmosphere and instrumental polarization, polarization statistics, and observational techniques for radio, optical, and X/γ wavelengths; and (iv) science cases for astronomical polarimetry: solar and stellar physics, planetary system bodies, interstellar matter, astrobiology, astronomical masers, pulsars, galactic magnetic fields, gamma-ray bursts, active galactic nuclei, and cosmic microwave background radiation.

  9. Polarization feedback laser stabilization (United States)

    Esherick, P.; Owyoung, A.


    A system for locking two Nd:YAG laser oscillators includes an optical path for feeding the output of one laser into the other with different polarizations. Elliptical polarization is incorporated into the optical path so that the change in polarization that occurs when the frequencies coincide may be detected to provide a feedback signal to control one laser relative to the other. 4 figs.

  10. Analyzing Spacecraft Telecommunication Systems (United States)

    Kordon, Mark; Hanks, David; Gladden, Roy; Wood, Eric


    Multi-Mission Telecom Analysis Tool (MMTAT) is a C-language computer program for analyzing proposed spacecraft telecommunication systems. MMTAT utilizes parameterized input and computational models that can be run on standard desktop computers to perform fast and accurate analyses of telecommunication links. MMTAT is easy to use and can easily be integrated with other software applications and run as part of almost any computational simulation. It is distributed as either a stand-alone application program with a graphical user interface or a linkable library with a well-defined set of application programming interface (API) calls. As a stand-alone program, MMTAT provides both textual and graphical output. The graphs make it possible to understand, quickly and easily, how telecommunication performance varies with variations in input parameters. A delimited text file that can be read by any spreadsheet program is generated at the end of each run. The API in the linkable-library form of MMTAT enables the user to control simulation software and to change parameters during a simulation run. Results can be retrieved either at the end of a run or by use of a function call at any time step.

  11. Downhole Fluid Analyzer Development

    Energy Technology Data Exchange (ETDEWEB)

    Bill Turner


    A novel fiber optic downhole fluid analyzer has been developed for operation in production wells. This device will allow real-time determination of the oil, gas and water fractions of fluids from different zones in a multizone or multilateral completion environment. The device uses near infrared spectroscopy and induced fluorescence measurement to unambiguously determine the oil, water and gas concentrations at all but the highest water cuts. The only downhole components of the system are the fiber optic cable and windows. All of the active components--light sources, sensors, detection electronics and software--will be located at the surface, and will be able to operate multiple downhole probes. Laboratory testing has demonstrated that the sensor can accurately determine oil, water and gas fractions with a less than 5 percent standard error. Once installed in an intelligent completion, this sensor will give the operating company timely information about the fluids arising from various zones or multilaterals in a complex completion pattern, allowing informed decisions to be made on controlling production. The research and development tasks are discussed along with a market analysis.

  12. Digital Microfluidics Sample Analyzer (United States)

    Pollack, Michael G.; Srinivasan, Vijay; Eckhardt, Allen; Paik, Philip Y.; Sudarsan, Arjun; Shenderov, Alex; Hua, Zhishan; Pamula, Vamsee K.


    Three innovations address the needs of the medical world with regard to microfluidic manipulation and testing of physiological samples in ways that can benefit point-of-care needs for patients such as premature infants, for which drawing of blood for continuous tests can be life-threatening in their own right, and for expedited results. A chip with sample injection elements, reservoirs (and waste), droplet formation structures, fluidic pathways, mixing areas, and optical detection sites, was fabricated to test the various components of the microfluidic platform, both individually and in integrated fashion. The droplet control system permits a user to control droplet microactuator system functions, such as droplet operations and detector operations. Also, the programming system allows a user to develop software routines for controlling droplet microactuator system functions, such as droplet operations and detector operations. A chip is incorporated into the system with a controller, a detector, input and output devices, and software. A novel filler fluid formulation is used for the transport of droplets with high protein concentrations. Novel assemblies for detection of photons from an on-chip droplet are present, as well as novel systems for conducting various assays, such as immunoassays and PCR (polymerase chain reaction). The lab-on-a-chip (a.k.a., lab-on-a-printed-circuit board) processes physiological samples and comprises a system for automated, multi-analyte measurements using sub-microliter samples of human serum. The invention also relates to a diagnostic chip and system including the chip that performs many of the routine operations of a central labbased chemistry analyzer, integrating, for example, colorimetric assays (e.g., for proteins), chemiluminescence/fluorescence assays (e.g., for enzymes, electrolytes, and gases), and/or conductometric assays (e.g., for hematocrit on plasma and whole blood) on a single chip platform.

  13. Regolith Evolved Gas Analyzer (United States)

    Hoffman, John H.; Hedgecock, Jud; Nienaber, Terry; Cooper, Bonnie; Allen, Carlton; Ming, Doug


    The Regolith Evolved Gas Analyzer (REGA) is a high-temperature furnace and mass spectrometer instrument for determining the mineralogical composition and reactivity of soil samples. REGA provides key mineralogical and reactivity data that is needed to understand the soil chemistry of an asteroid, which then aids in determining in-situ which materials should be selected for return to earth. REGA is capable of conducting a number of direct soil measurements that are unique to this instrument. These experimental measurements include: (1) Mass spectrum analysis of evolved gases from soil samples as they are heated from ambient temperature to 900 C; and (2) Identification of liberated chemicals, e.g., water, oxygen, sulfur, chlorine, and fluorine. REGA would be placed on the surface of a near earth asteroid. It is an autonomous instrument that is controlled from earth but does the analysis of regolith materials automatically. The REGA instrument consists of four primary components: (1) a flight-proven mass spectrometer, (2) a high-temperature furnace, (3) a soil handling system, and (4) a microcontroller. An external arm containing a scoop or drill gathers regolith samples. A sample is placed in the inlet orifice where the finest-grained particles are sifted into a metering volume and subsequently moved into a crucible. A movable arm then places the crucible in the furnace. The furnace is closed, thereby sealing the inner volume to collect the evolved gases for analysis. Owing to the very low g forces on an asteroid compared to Mars or the moon, the sample must be moved from inlet to crucible by mechanical means rather than by gravity. As the soil sample is heated through a programmed pattern, the gases evolved at each temperature are passed through a transfer tube to the mass spectrometer for analysis and identification. Return data from the instrument will lead to new insights and discoveries including: (1) Identification of the molecular masses of all of the gases

  14. Polarization modulators for CMBPol

    Energy Technology Data Exchange (ETDEWEB)

    Ade, P A R; Savini, G [Cardiff University, School of Physics and Astronomy, Queens Buildings, The Parade, Cardiff, CF24 3AA (United Kingdom); Chuss, D T [NASA Goddard Space Flight Center, Code 665, Greenbelt, MD, 20771 (United States); Hanany, S [School of Physics and Astronomy, University of Minnesota/Twin Cities, Minneapolis, MN, 55455 (United States); Haynes, V; Pisano, G [University of Manchester, School of Physics and Astronomy - Alan Turing Building, Upper Brooke street, Manchester, M13 4PL (United Kingdom); Keating, B G [Department of Physics, University of California, San Diego, La Jolla, CA 92093-0424 (United States); Kogut, A [Code 665 Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Ruhl, J E [Physics Department, Case Western Reserve University, Cleveland, OH, 44106 (United States); Wollack, E J [Observational Cosmology Laboratory, NASA/GSFC, Greenbelt, MD 20771 (United States)


    We review a number of technologies that are candidates for active polarization modulators for CMBPol. The technologies are appropriate for instruments that use bolometric detectors and include birefringent crystal-based and metal-mesh-based half-wave plates, variable phase polarization modulator, Faraday rotator, and photolithographed modulators. We also give a current account of the status of millimeter-wave orthomode transducers.

  15. The Polar Insulation Investigation (United States)

    Urban-Rich, Juanita


    In this article, the author developed an activity called "The Polar Insulation Investigation." This activity builds on students' natural interest in "things polar" and introduces them to animal adaptations in a unique way. The aim of the exploration is to determine the role of animal coverings (e.g., blubber, fur, and feathers) and to see which is…

  16. Galactic Diffuse Polarized Emission

    Indian Academy of Sciences (India)

    Diffuse polarized emission by synchrotron is a key tool to investigate magnetic fields in the Milky Way, particularly the ordered component of the large scale structure. Key observables are the synchrotron emission itself and the RM is by Faraday rotation. In this paper the main properties of the radio polarized diffuse emission ...

  17. Terahertz polarization imaging

    NARCIS (Netherlands)

    Van der Valk, N.C.J.; Van der Marel, W.A.M.; Planken, P.C.M.


    We present a new method to measure the polarization state of a terahertz pulse by using a modified electrooptic sampling setup. To illustrate the power of this method, we show two examples in which the knowledge of the polarization of the terahertz pulse is essential for interpreting the results:

  18. Chromatic polarization effects of swept waveforms in FDML lasers and fiber spools. (United States)

    Wieser, Wolfgang; Palte, Gesa; Eigenwillig, Christoph M; Biedermann, Benjamin R; Pfeiffer, Tom; Huber, Robert


    We present detailed investigations of chromatic polarization effects, caused by fiber spools used in FDML lasers and buffering spools for rapidly wavelength swept lasers. We introduce a novel wavelength swept FDML laser source, specially tailored for polarization sensitive optical coherence tomography (OCT) which switches between two different linear polarization states separated by 45°, i.e. 90° on the Poincaré sphere. The polarization maintaining laser cavity itself generates a stable linear polarization state and uses an external buffering technique in order to provide alternating polarization states for successive wavelength sweeps. The design of the setup is based on a comprehensive analysis of the polarization output from FDML lasers, using a novel 150 MHz polarization analyzer. We investigate the fiber polarization properties related to swept source OCT for different fiber delay topologies and analyze the polarization state of different FDML laser sources. © 2012 Optical Society of America

  19. Polarization Mode Dispersion

    CERN Document Server

    Galtarossa, Andrea


    This book contains a series of tutorial essays on polarization mode dispersion (PMD) by the leading experts in the field. It starts with an introductory review of the basic concepts and continues with more advanced topics, including a thorough review of PMD mitigation techniques. Topics covered include mathematical representation of PMD, how to properly model PMD in numerical simulations, how to accurately measure PMD and other related polarization effects, and how to infer fiber properties from polarization measurements. It includes discussions of other polarization effects such as polarization-dependent loss and the interaction of PMD with fiber nonlinearity. It additionally covers systems issues like the impact of PMD on wavelength division multiplexed systems. This book is intended for research scientists or engineers who wish to become familiar with PMD and its system impacts.

  20. Parallel Polarization State Generation

    CERN Document Server

    She, Alan


    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 characteristi...

  1. Polarization Optics in Telecommunications

    CERN Document Server

    Damask, Jay N


    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...

  2. Optically polarized 3He (United States)

    Gentile, T. R.; Nacher, P. J.; Saam, B.; Walker, T. G.


    This article reviews the physics and technology of producing large quantities of highly spin-polarized 3He nuclei using spin-exchange (SEOP) and metastability-exchange (MEOP) optical pumping. Both technical developments and deeper understanding of the physical processes involved have led to substantial improvements in the capabilities of both methods. For SEOP, the use of spectrally narrowed lasers and K-Rb mixtures has substantially increased the achievable polarization and polarizing rate. For MEOP nearly lossless compression allows for rapid production of polarized 3He and operation in high magnetic fields has likewise significantly increased the pressure at which this method can be performed, and revealed new phenomena. Both methods have benefitted from development of storage methods that allow for spin-relaxation times of hundreds of hours, and specialized precision methods for polarimetry. SEOP and MEOP are now widely applied for spin-polarized targets, neutron spin filters, magnetic resonance imaging, and precision measurements.


    Directory of Open Access Journals (Sweden)

    Michele Mistry


    Full Text Available Now-a-days sentiment analysis has become a hot research area. With the increasing use of internet, people express their views by using social media, blogs, etc. So there is a dire need to analyze people’s opinions. Sentiment classification is the main task of sentiment analysis. But while classifying sentiments, the problem of polarity shift occurs. Polarity shift is considered as a very crucial problem. Polarity shift changes a text from positive to negative and vice versa. In this paper, a hybrid approach is proposed for polarity shift detection of negation (explicit and implicit and contrast. The hybrid approach consists of a rule-based approach for detecting explicit negation and contrast and a lexicon called SentiWordNet for detecting implicit negation. The proposed approach outperforms its baselines.

  4. Molecular content of polar-ring galaxies (United States)

    Combes, F.; Moiseev, A.; Reshetnikov, V.


    We have searched for CO lines in a sample of 21 new morphologically determined polar-ring galaxies (of which nine are kinematically confirmed), obtained from a wide search in the Galaxy Zoo project by Moiseev and collaborators. Polar-ring galaxies (PRGs) are a unique class of objects, tracing special episodes in the galaxy mass assembly: they can be formed through galaxy interaction and merging, but also through accretion from cosmic filaments. Furthermore, they enable the study of dark matter haloes in three dimensions. The polar ring itself is a sub-system rich in gas, where molecular gas is expected, and new stars are formed. Among the sample of 21 PRGs, we have detected five CO-rich systems, that can now be followed up with higher spatial resolution. Their average molecular mass is 9.4 × 109M⊙, and their average gas fraction is 27% of their baryonic mass, with a range from 15 to 43%, implying that they have just accreted a large amount of gas. The position of the detected objects in the velocity-magnitude diagram is offset from the Tully-Fisher relation of normal spirals, as was already found for PRGs. This work is part of our multi-wavelength project to determine the detailed morphology and dynamics of PRGs, test through numerical models their formation scenario, and deduce their dark matter content and 3D-shape. Based on observations carried out with the IRAM 30 m telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).Spectra of detections are available at the CDS via anonymous ftp to ("> or via

  5. The Polar Plasma Wave Instrument (United States)

    Gurnett, D. A.; Persoon, A. M.; Randall, R. F.; Odem, D. L.; Remington, S. L.; Averkamp, T. F.; Debower, M. M.; Hospodarsky, G. B.; Huff, R. L.; Kirchner, D. L.


    The Plasma Wave Instrument on the Polar spacecraft is designed to provide measurements of plasma waves in the Earth's polar regions over the frequency range from 0.1 Hz to 800 kHz. Three orthogonal electric dipole antennas are used to detect electric fields, two in the spin plane and one aligned along the spacecraft spin axis. A magnetic loop antenna and a triaxial magnetic search coil antenna are used to detect magnetic fields. Signals from these antennas are processed by five receiver systems: a wideband receiver, a high-frequency waveform receiver, a low-frequency waveform receiver, two multichannel analyzers; and a pair of sweep frequency receivers. Compared to previous plasma wave instruments, the Polar plasma wave instrument has several new capabilities. These include (1) an expanded frequency range to improve coverage of both low- and high-frequency wave phenomena, (2) the ability to simultaneously capture signals from six orthogonal electric and magnetic field sensors, and (3) a digital wideband receiver with up to 8-bit resolution and sample rates as high as 249k samples s(exp -1).

  6. Complex polarity reversals in a geodynamo model (United States)

    Olson, Peter L.; Glatzmaier, Gary A.; Coe, Robert S.


    Complex polarity reversals in numerical dynamos driven by thermo-chemical convection are analyzed in terms of magnetic field intensity variations, transitional field structure, and other observable characteristics. Our most Earth-like dynamos are characterized by long stable polarity chrons with dipole-dominant magnetic fields punctuated by occasional polarity reversals, and are found within a transition region of parameter space between non-reversing strongly dipolar dynamos and chaotic multi-polar-type dynamos. Dynamos in the transition region have elevated dipole terms, reduced quadrupole terms, magnetic energy that decreases slowly with spherical harmonic degree, and broadband dipole frequency spectra. Their axial dipole intensity histograms are trimodal, with large modes representing the stable polarity states and an intermediate mode representing the transitional multi-polar state. The dipole family intensity exceeds the quadrupole family intensity on the core-mantle boundary during stable polarity times, but during transitions the two families are similar. A complex dynamo model reversal is compared with paleomagnetic reconstructions around the Matuyama-Brunhes polarity transition. Both start with a gradual decrease of the dipole intensity, followed by a precursor reversal and transient polarity recovery, then a rapid dipole collapse and a final reversal that initiates with reverse flux generation in one hemisphere. Virtual geomagnetic poles (VGPs) from sites near the reverse flux trace complex paths and cross the equator several thousand years before the simpler VGP paths from more distant sites, and magnetic intensity variations during the dynamo model reversal correlate with intensity variations inferred for the Matuyama-Brunhes transition.

  7. Suomi National Polar-Orbiting Partnership Visible Infrared Imaging Radiometer Suite Polarization Sensitivity Analysis (United States)

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


    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.

  8. Polarization properties of receiving telescopes in atmospheric remote sensing polarization lidars. (United States)

    Luo, Jing; Liu, Dong; Huang, Zihao; Wang, Binyu; Bai, Jian; Cheng, Zhongtao; Zhang, Yupeng; Tang, Peijun; Yang, Liming; Su, Lin


    A receiving telescope is an indispensable component in an atmospheric remote sensing polarization lidar. In order to achieve accurate atmospheric depolarization measurements, it is necessary to study the polarization properties of receiving telescopes, which are embodied by their Mueller matrices. In this paper, the Mueller matrices of receiving telescopes are obtained by ray tracing with space vectors. The relationship between the measurement errors of the atmospheric depolarization parameter and the elements of the Mueller matrix of receiving telescopes is derived. The polarization properties of receiving telescopes in terms of orientation, field of view, and F number are analyzed, respectively. By comparing two common receiving telescopes in linear and circular polarization lidars, it is found that the measurement errors caused by the Newton telescopes in circular polarization lidars are significantly greater than those in linear polarization lidars, while the performances of the Cassegrain telescopes in the two lidars are almost identical. What is more, the measurement errors caused by the Cassegrain telescopes are much less than the counterparts caused by the Newton telescopes. According to the comparison results, the optimal telescopes are respectively presented for polarization lidars working in different polarization states and laser wavelengths.

  9. Summertime total ozone variations over middle and polar latitudes


    Fioletov, Vitali E.; Shepherd, Theodore G.


    The statistical relationship between springtime and summertime ozone over middle and polar latitudes is analyzed using zonally averaged total ozone data. Shortterm variations in springtime midlatitude ozone demonstrate only a modest correlation with springtime polar ozone variations. However by early summer, ozone variations throughout the extratropics are highly correlated. Analysis of correlation functions indicates that springtime midlatitude ozone, not polar ozone, is the best predictor f...

  10. Snapshot imaging Mueller matrix polarimeter using polarization gratings


    Kudenov, Michael W.; Escuti, Michael J.; Hagen, Nathan; Dereniak, Eustace L.; Oka, Kazuhiko


    A snapshot imaging Mueller matrix polarimeter (SIMMP) is theoretically described and empirically demonstrated through simulation. Spatial polarization fringes are localized onto a sample by incorporating polarization gratings (PGs) into a polarization generator module. These fringes modulate the Mueller matrix (MM) components of the sample, which are subsequently isolated with PGs in an analyzer module. The MM components are amplitude modulated onto spatial carrier frequencies which, due to t...

  11. Polarized scintillator targets (United States)

    van den Brandt, B.; Bunyatova, E. I.; Hautle, P.; Konter, J. A.; Mango, S.


    The hydrogen nuclei in an organic scintillator have been polarized to more than 80% and the deuterons in its fully deuterated version to 24%. The scintillator, doped with TEMPO, has been polarized dynamically in a field of 2.5 T in a vertical dilution refrigerator in which a plastic lightguide transports the scintillation light from the sample in the mixing chamber to a photomultiplier outside the cryostat. Sizeable solid samples with acceptable optical properties and light output have been prepared and successfully operated as "live" polarized targets in nuclear physics experiments.

  12. Polarized scintillator targets

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, B. van den E-mail:; Bunyatova, E.I.; Hautle, P.; Konter, J.A.; Mango, S


    The hydrogen nuclei in an organic scintillator have been polarized to more than 80% and the deuterons in its fully deuterated version to 24%. The scintillator, doped with TEMPO, has been polarized dynamically in a field of 2.5 T in a vertical dilution refrigerator in which a plastic lightguide transports the scintillation light from the sample in the mixing chamber to a photomultiplier outside the cryostat. Sizeable solid samples with acceptable optical properties and light output have been prepared and successfully operated as 'live' polarized targets in nuclear physics experiments.


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


    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)

  14. Coordenadas polares: curvas maravillosas


    Norberto Jaime Chau Pérez; Roy Wil Sánchez Gutiérrez


    Se presenta una actividad colaborativa en la que se trabaja el tema coordenadas polares. Se presentan los objetivos de aprendizaje, el desarrollo de la actividad, los conocimientos previos necesarios y recomendaciones para una aplicación posterior.

  15. Dynamic nuclear spin polarization

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  16. EDITORIAL: Polarization Optics (United States)

    Turunen, Jari; Friesem, Asher A.; Friberg, Ari T.


    This special issue on Polarization Optics contains one review article and 23 research papers, many of which are based on presentations at the International Commission for Optics Topical Meeting on Polarization Optics, held in Polvijärvi, Finland, between 30 June and 3 July 2003. While this issue should not in any sense be considered as a `proceedings' of this meeting, the possibility of submitting papers to it was widely advertised during the meeting, which was attended by a large fraction of prominent scientists in the field of polarization optics. Thus the quality of papers in this special issue is high. In announcing both the meeting and this special issue, we emphasized that the concept of `polarization optics' should be understood in a wide sense. In fact, all contributions dealing with the vectorial nature of light were welcome. As a result, the papers included here cover a wide range of different aspects of linear and nonlinear polarization optics. Both theoretical and experimental features are discussed. We are pleased to see that the conference and this special issue both reflect the wide diversity of important and novel polarization phenomena in optics. The papers in this special issue, and other recently published works, demonstrate that even though polarization is a fundamental property of electromagnetic fields, interest in it is rapidly increasing. The fundamental relations between partial coherence and partial polarization are currently under vigorous research in electromagnetic coherence theory. In diffractive optics it has been found that the exploitation of the vectorial nature of light can be of great benefit. Fabrication of sophisticated, spatially variable polarization-control elements is becoming possible with the aid of nanolithography. Polarization singularities and the interplay of bulk properties and topology in nanoscale systems have created much enthusiasm. In nonlinear optics, the second harmonic waves generated on reflection and

  17. Polar Cap Patch Dynamics (United States)


    associated with the rotation of the extreme density may in itself lead to a stronger growth of ionospheric irregularities . These irregularities may...continue to grow all the way across the polar cap. The result is more efficient creation of ionospheric irregularities . Title 4: Motion of polar...the cusp ionosphere over Svalbard to investigate the production of decameter scale irregularities in the electron plasma associated with HF radar

  18. Job Market Polarization and Employment Protection in Europe

    DEFF Research Database (Denmark)

    Pertold-Gebicka, Barbara

    Although much attention has been paid to the polarization of national labor markets, with employment and wage growth occurring in both low- and high- but not middle-skill occupations, there is little consistent evidence on cross-country dierences in this process. I analyze job polarization in 12...

  19. Detecting Spin-Polarized Currents in Ballistic Nanostructures

    DEFF Research Database (Denmark)

    Potok, R.; Folk, J.; M. Marcus, C.


    We demonstrate a mesoscopic spin polarizer/analyzer system that allows the spin polarization of current from a quantum point contact in an in-plane magnetic field to be measured. A transverse focusing geometry is used to couple current from an emitter point contact into a collector point contact....

  20. Effects of gravitational waves on the polarization of pulsars


    Hacyan, Shahen


    The polarization of electromagnetic waves in the presence of a gravitational wave is analyzed. The rotation of the polarization angle and the Stokes parameters are deduced. A possible application to the detection of stochastic background of gravitational waves is proposed as a complement to the pulsar timing method.

  1. Regulation of osteoclast polarization. (United States)

    Takahashi, Naoyuki; Ejiri, Sadakazu; Yanagisawa, Shigeru; Ozawa, Hidehiro


    Osteoclast function consists of several processes: recognition of mineralized tissues, development of ruffled borders and sealing zones, secretion of acids and proteolytic enzymes into the space beneath the ruffled border, and incorporation and secretion of bone degradation products using the transcytosis system. One of the most important questions concerning osteoclast function is how osteoclasts recognize bone and polarize. During the past decade, new approaches have been taken to investigate the regulation of osteoclast polarization. Attachment of osteoclasts to some proteins containing the Arg-Gly-Asp sequence motif through vitronectin receptors is the first step in inducing the polarization of osteoclasts. Physical properties of bone such as hardness or roughness are also required to induce osteoclast polarity. Osteoclasts cultured even on plastic dishes secrete protons toward the dish surface, suggesting that osteoclasts recognize plastic as a mineralized matrix and secrete protons. This notion was supported by the recent findings that bisphosphonates and reveromycin A were specifically incorporated into polarized osteoclasts cultured even on plastic dishes. On the other hand, a sealing zone, defined as a thick band of actin, is induced in osteoclasts adherent only on an apatite-containing mineralized matrix. These results suggest that osteoclasts recognize physical properties of the mineralized tissue to secrete protons, and also sense apatite itself or components of apatite to form the sealing zone. Here, we review recent findings on the regulation of osteoclast polarization. We also discuss how osteoclasts recognize mineralized tissues to form the sealing zone.

  2. Polarizations on abelian varieties (United States)

    Silverberg, A.; Zarhin, Yu. G.


    Every isogeny class over an algebraically closed field contains a principally polarized abelian variety ([10, corollary 1 to theorem 4 in section 23]). Howe ([3]; see also [4]) gave examples of isogeny classes of abelian varieties over finite fields with no principal polarizations (but not with the degrees of all the polarizations divisible by a given non-zero integer, as in Theorem 1·1 below). In [17] we obtained, for all odd primes [script l], isogeny classes of abelian varieties in positive characteristic, all of whose polarizations have degree divisible by [script l]2. We gave results in the more general context of invertible sheaves; see also Theorems 6·1 and 5·2 below. Our results gave the first examples for which all the polarizations of the abelian varieties in an isogeny class have degree divisible by a given prime. Inspired by our results in [17], Howe [5] recently obtained, for all odd primes [script l], examples of isogeny classes of abelian varieties over fields of arbitrary characteristic different from [script l] (including number fields), all of whose polarizations have degree divisible by [script l]2.

  3. Polarized Light Microscopy (United States)

    Frandsen, Athela F.


    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

  4. Polarization Ratio Determination with Two Identical Linearly Polarized Antennas (United States)


    Fourier transform analysis of 21 measurements with one of the antennas rotating about its axis a circular polarization ratio is derived which can be... transformed into an equivalent linear polarization ratio. A linearly polarized reference antenna is not required. The technique was verified the polarization ratio of an an- tenna is of interest for potential frequency / polarization re-use. Newell [1] and Joy [2] developed the three

  5. Stimulated electromagnetic emission polarization under different polarizations of pump waves


    E. D. Tereshchenko; R. Y. Yurik; Baddeley, L.


    The results of investigations into the stimulated electromagnetic emission (SEE) polarization under different modes of the pump wave polarization are presented. The present results were obtained in November 2012 during a heating campaign utilizing the SPEAR (Space Plasma Exploration by Active Radar) heating facility, transmitting in both O- and X-mode polarization, and a PGI (Polar Geophysical Institute) radio interferometer capable of recording the polarization of the recei...

  6. Quasi-periodic compressive waves in polar plumes (United States)

    DeForest, C. E.; Gurman, J. B.


    The observation of polar plumes in the south polar coronal hole, carried out on 7 March 1996 by the Solar and Heliospheric Observatory (SOHO), are analyzed. These polar plumes are cool density structures that arise from morphologically unipolar magnetic footpoints. Data from the extreme ultraviolet imaging telescope show quasi-periodic perturbations in the brightness of the Fe IX and X line emissions at 171 A from polar plumes. The perturbations have periods of 10 to 15 min, and repeat for several cycles suggesting that they are compressive waves propagating through the plume at or near the Alfven speed. Possible explanations for the observed phenomenon are proposed.

  7. Building hospital TQM teams: effective polarity analysis and maximization. (United States)

    Hurst, J B


    Building and maintaining teams require careful attention to and maximization of such polar opposites (¿polarities¿) as individual and team, directive and participatory leadership, task and process, and stability and change. Analyzing systematic elements of any polarity and listing blocks, supports, and flexible ways to maximize it will prevent the negative consequences that occur when treating a polarity like a solvable problem. Flexible, well-timed shifts from pole to pole result in the maximization of upside and minimization of downside consequences.

  8. Method for using polarization gating to measure a scattering sample (United States)

    Baba, Justin S.


    Described herein are systems, devices, and methods facilitating optical characterization of scattering samples. A polarized optical beam can be directed to pass through a sample to be tested. The optical beam exiting the sample can then be analyzed to determine its degree of polarization, from which other properties of the sample can be determined. In some cases, an apparatus can include a source of an optical beam, an input polarizer, a sample, an output polarizer, and a photodetector. In some cases, a signal from a photodetector can be processed through attenuation, variable offset, and variable gain.

  9. Polarization: A Must for Fusion

    Directory of Open Access Journals (Sweden)

    Guidal M.


    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. NMR-Based Identification of Metabolites in Polar and Non-Polar Extracts of Avian Liver. (United States)

    Fathi, Fariba; Brun, Antonio; Rott, Katherine H; Falco Cobra, Paulo; Tonelli, Marco; Eghbalnia, Hamid R; Caviedes-Vidal, Enrique; Karasov, William H; Markley, John L


    Metabolites present in liver provide important clues regarding the physiological state of an organism. The aim of this work was to evaluate a protocol for high-throughput NMR-based analysis of polar and non-polar metabolites from a small quantity of liver tissue. We extracted the tissue with a methanol/chloroform/water mixture and isolated the polar metabolites from the methanol/water layer and the non-polar metabolites from the chloroform layer. Following drying, we re-solubilized the fractions for analysis with a 600 MHz NMR spectrometer equipped with a 1.7 mm cryogenic probe. In order to evaluate the feasibility of this protocol for metabolomics studies, we analyzed the metabolic profile of livers from house sparrow (Passer domesticus) nestlings raised on two different diets: livers from 10 nestlings raised on a high protein diet (HP) for 4 d and livers from 12 nestlings raised on the HP diet for 3 d and then switched to a high carbohydrate diet (HC) for 1 d. The protocol enabled the detection of 52 polar and nine non-polar metabolites in ¹H NMR spectra of the extracts. We analyzed the lipophilic metabolites by one-way ANOVA to assess statistically significant concentration differences between the two groups. The results of our studies demonstrate that the protocol described here can be exploited for high-throughput screening of small quantities of liver tissue (approx. 100 mg wet mass) obtainable from small animals.

  11. Polar low monitoring (United States)

    Bobylev, Leonid; Zabolotskikh, Elizaveta; Mitnik, Leonid


    Polar lows are intense mesoscale atmospheric low pressure weather systems, developing poleward of the main baroclinic zone and associated with high surface wind speeds. Small size and short lifetime, sparse in-situ observations in the regions of their development complicate polar low study. Our knowledge of polar lows and mesocyclones has come almost entirely during the period of satellite remote sensing since, by virtue of their small horizontal scale, it was rarely possible to analyse these lows on conventional weather charts using only the data from the synoptic observing network. However, the effects of intense polar lows have been felt by coastal communities and seafarers since the earliest times. These weather systems are thought to be responsible for the loss of many small vessels over the centuries, although the nature of the storms was not understood and their arrival could not be predicted. The actuality of the polar low research is stipulated by their high destructive power: they are a threat to such businesses as oil and gas exploration, fisheries and shipping. They could worsen because of global warming: a shrinking of sea ice around the North Pole, which thawed to its record minimum in the summer of 2007, is likely to give rise to more powerful storms that form only over open water and can cause hurricane-strength winds. Therefore, study of polar lows, their timely detection, tracking and forecasting represents a challenge for today meteorology. Satellite passive microwave data, starting from Special Sensor Microwave Imager (SSM/I) onboard Defense Meteorological Satellite Program (DMSP) satellite, remain invaluable source of regularly available remotely sensed data to study polar lows. The sounding in this spectral range has several advantages in comparison with observations in visible and infrared ranges and Synthetic Aperture Radar (SAR) data: independence on day time and clouds, regularity and high temporal resolution in Polar Regions. Satellite

  12. Polarization evolution of radially polarized partially coherent vortex fields: role of Gouy phase of Laguerre-Gauss beams. (United States)

    Martínez-Herrero, R; Prado, F


    In the framework of the paraxial approximation, we derive the analytical expressions for describing the effect of the Gouy phase of Laguerre-Gauss beams on the polarization evolution of partially coherent vortex fields whose electric field vector at some transverse plane exhibits a radially polarized behavior. At each transverse plane, the polarization distribution across the beam profile is characterized by means of the percentage of irradiance associated with the radial or azimuthal components. The propagation laws for these percentages are also presented. As an illustrative example, we analyze a radially polarized partially coherent vortex beam.

  13. Photon polarization in np fusion

    CERN Document Server

    Ramachandran, G; Kumar, S P


    A model-independent irreducible tensor formalism is developed to discuss photon polarization in np fusion. It is shown that photon polarization arising out of the interference of the dominant isovector M1 amplitude at thermal neutron energies with the small isoscalar M1 and E2 amplitudes can be studied with advantage in suitably designed polarized beam and polarized target experiments, where the neutron and proton polarizations are either opposite to each other or orthogonal to each other. (letter to the editor)

  14. Polarized positrons and electrons at the linear collider

    Energy Technology Data Exchange (ETDEWEB)

    Moortgat-Pick, G. [CERN TH Division, Department of Physics, CH-1211 Geneva 23 (Switzerland); IPPP, University of Durham, Durham DH1 3LE (United Kingdom)], E-mail:; Abe, T. [University of Colorado, Boulder, CO 80309-390 (United States); Alexander, G. [University of Tel-Aviv, Tel-Aviv 69978 (Israel); Ananthanarayan, B. [Centre for High Energy Physics, Indian Institute of Science, Bangalore, 560012 (India); Babich, A.A. [Pavel Sukhoi Technical University, Gomel, 246746 (Belarus); Bharadwaj, V. [Stanford Linear Accelerator Center, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Barber, D. [DESY, Deutsches Elektronen Synchrotron, D-22603 Hamburg (Germany); Bartl, A. [Institut fuer Theoretische Physik, Universitaet Wien, A-1090 Wien (Austria); Brachmann, A. [Stanford Linear Accelerator Center, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Chen, S. [University of Colorado, Boulder, CO 80309-390 (United States); Clarke, J. [CCLRC, ASTeC, Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Clendenin, J.E. [Stanford Linear Accelerator Center, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Dainton, J. [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Desch, K. [Phys. Institut, Albert-Ludwigs Universitaet Freiburg, D-79104 Freiburg (Germany); Diehl, M. [DESY, Deutsches Elektronen Synchrotron, D-22603 Hamburg (Germany); Dobos, B.; Dorland, T. [University of Colorado, Boulder, CO 80309-390 (United States); Dreiner, H.K. [Phys. Institut, Universitaet Bonn, D-53115 Bonn (Germany); Eberl, H. [Inst. f. Hochenergiephysik, Osterr. Akademie d. Wissenschaften, A-1050 Wien (Austria); Ellis, J. [CERN TH Division, Department of Physics, CH-1211 Geneva 23 (Switzerland)] (and others)


    The proposed International Linear Collider (ILC) is well-suited for discovering physics beyond the Standard Model and for precisely unraveling the structure of the underlying physics. The physics return can be maximized by the use of polarized beams. This report shows the paramount role of polarized beams and summarizes the benefits obtained from polarizing the positron beam, as well as the electron beam. The physics case for this option is illustrated explicitly by analyzing reference reactions in different physics scenarios. The results show that positron polarization, combined with the clean experimental environment provided by the linear collider, allows to improve strongly the potential of searches for new particles and the identification of their dynamics, which opens the road to resolve shortcomings of the Standard Model. The report also presents an overview of possible designs for polarizing both beams at the ILC, as well as for measuring their polarization.

  15. Modeling diffusion coefficients in binary mixtures of polar and non-polar compounds

    DEFF Research Database (Denmark)

    Medvedev, Oleg; Shapiro, Alexander


    The theory of transport coefficients in liquids, developed previously, is tested on a description of the diffusion coefficients in binary polar/non-polar mixtures, by applying advanced thermodynamic models. Comparison to a large set of experimental data shows good performance of the model. Only...... components and to only one parameter for mixtures consisting of non-polar components. A possibility of complete prediction of the parameters is discussed....... four temperature-independent parameters are required in order to describe the behavior of diffusion coefficients at different temperatures. The physical meaning of the parameters is analyzed. This makes it possible to reduce further their number to just two parameters for described mixtures with polar...

  16. Wide Angle Polarization Analysis with Neutron Spin Filters (United States)

    Ye, Q.; Gentile, T. R.; Anderson, J.; Broholm, C.; Chen, W. C.; DeLand, Z.; Erwin, R. W.; Fu, C. B.; Fuller, J.; Kirchhoff, A.; Rodriguez-Rivera, J. A.; Thampy, V.; Walker, T. G.; Watson, S.

    We report substantial improvements in a compact wide angle neutron spin filter system that was recently employed on the Multi- Axis Crystal Spectrometer at the Center for Neutron Research at the U.S. National Institute of Standards and Technology. The apparatus consists of a cylindrical 3He polarizer cell and wide-angle 3He analyzer cells, a vertical solenoid to provide a uniform magnetic field, and a shielded radio-frequency solenoid for the polarizer cell. Nuclear magnetic resonance is employed to reverse the polarization in the polarizer cell and monitor the 3He polarization in all cells. The first experiment using this apparatus was carried out with cylindrical analyzer cells with limited angular coverage due to low polarizations in fused quartz cells. We present results for aluminosilicate glass analyzer cells that cover 110 ∘ and have long relaxation times (100 h to 400 h). Using two 100 W diode bars spectrally narrowed with chirped volume Bragg gratings, we have obtained 65% - 80% 3He polarization in these cells. The 3He polarization has been measured by neutron transmission and electron paramagnetic resonance. Additional progress includes an improved holding field solenoid and decreased spin-flip losses.

  17. Physics of polarized targets

    CERN Document Server

    Niinikoski, Tapio


    For developing, building and operating solid polarized targets we need to understand several fields of physics that have seen sub stantial advances during the last 50 years. W e shall briefly review a selection of those that are important today. These are: 1) quantum statistical methods to describe saturation and relaxation in magnetic resonance; 2) equal spin temperature model for dy namic nuclear polarization; 3 ) weak saturation during NMR polarization measurement; 4 ) refrigeration using the quantum fluid properties of helium isotopes. These, combined with superconducting magnet technologies, permit today to reach nearly complete pola rization of almost any nuclear spins. Targets can be operated in frozen spin mode in rather low and inhomogeneous field of any orientation, and in DNP mode in beams of high intensity. Beyond such experiments of nuclear and particle physics, applications a re also emerging in macromolecular chemistry and in magnetic resonance imaging. This talk is a tribute to Michel Borghini...

  18. Time Domain Induced Polarization

    DEFF Research Database (Denmark)

    Fiandaca, Gianluca; Auken, Esben; Christiansen, Anders Vest


    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......%. Furthermore, the presence of low-pass filters in time-domain-induced polarization instruments affects the early times of the acquired decays (typically up to 100 ms) and has to be modeled in the forward response to avoid significant loss of resolution. The developed forward code has been implemented in a 1D...... polarization response when compared to traditional integral chargeability inversion. The quality of the inversion results has been assessed by a complete uncertainty analysis of the model parameters; furthermore, borehole information confirm the outcomes of the field interpretations. With this new accurate...

  19. A lunar polar expedition (United States)

    Dowling, Richard; Staehle, Robert L.; Svitek, Tomas


    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.

  20. Observation of a large parity nonconserving analyzing power in Xe

    Energy Technology Data Exchange (ETDEWEB)

    Szymanski, J.J.; Snow, W.M.; Bowman, J.D.; Cain, B.; Crawford, B.E.; Delheij, P.P.; Hartman, R.D.; Haseyama, T.; Keith, C.D.; Knudson, J.N.; Komives, A.; Leuschner, M.; Lowie, L.Y.; Masaike, A.; Matsuda, Y.; Mitchell, G.E.; Penttilae, S.I.; Postma, H.; Rich, D.; Roberson, N.R.; Seestrom, S.J.; Sharapov, E.I.; Stephenson, S.L.; Yen, Y.F.; Yuan, V.W. [Department of Physics, Indiana University, Bloomington, Indiana 47405 Duke University, Durham, North Carolina 27706 (United States)]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708 (United States)]|[Department of Physics, Faculty of Science, Kyoto University, Kyoto 606-01 (Japan)]|[North Carolina State University, Raleigh, North Carolina 27695 (United States)]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708 (United States)]|[University of Technology, P.O. Box 5064, 2600 GA Delft (The Netherlands)]|[Joint Institute for Nuclear Research, 141980 Dubna, Moscow, Region (Russia)


    A large parity nonconserving longitudinal analyzing power was discovered in polarized-neutron transmission through Xe. An analyzing power of 4.3{plus_minus}0.2{percent} was observed in a {ital p}-wave resonance at {ital E}{sub {ital n}}=3.2 eV. The measurement was performed with a liquid Xe target of natural isotopic abundance that was placed in the polarized epithermal neutron beam, flight path 2, at the Manuel Lujan Neutron Science Center. This apparatus was constructed by the TRIPLE Collaboration, and has been used for studies of parity symmetry in compound nuclear resonances. Part of the motivation of the experiment was to discover a nucleus appropriate for a sensitive test of time-reversal invariance in polarized-neutron transmission. The large analyzing power of the observed resonance may make it possible to design a test of time reversal invariance using a polarized-Xe target. {copyright} {ital 1996 The American Physical Society.}

  1. Metamaterial polarization converter analysis: limits of performance

    DEFF Research Database (Denmark)

    Markovich, Dmitry L.; Andryieuski, Andrei; Zalkovskij, Maksim


    In this paper, we analyze the theoretical limits of a metamaterial-based converter with orthogonal linear eigenpolarizations that allow linear-to-elliptical polarization transformation with any desired ellipticity and ellipse orientation. We employ the transmission line approach providing a needed...... level of the design generalization. Our analysis reveals that the maximal conversion efficiency for transmission through a single metamaterial layer is 50 %, while the realistic reflection configuration can give the conversion efficiency up to 90 %. We show that a double layer transmission converter...... and a single layer with a ground plane can have 100 % polarization conversion efficiency. We tested our conclusions numerically reaching the designated limits of efficiency using a simple metamaterial design. Our general analysis provides useful guidelines for the metamaterial polarization converter design...

  2. Citizen CATE Experiment and Polar Plume Dynamics (United States)

    Mitchell, Adriana; Penn, Matt; Baer, Robert; Bosh, Robert; Garrison, David; Gelderman, Richard; Hare, Honor; Isberner, Fred; Jensen, Logan; Kovac, Sarah; McKay, Myles; Pierce, Michael; Thompson, Patricia; Ursache, Andrei; Varsik, John R.; Walter, Donald; Watson, Zachary; Young, David; Citizen CATE Team


    During the summer of 2017, a total solar eclipse will pass over the continental United States, allowing millions of citizens the opportunity to experience a beautiful celestial event. The Citizen Continental-America Telescopic Eclipse (CATE) Experiment plans to harness the power of these many viewers by using volunteers from sites across the US to observe and record the total solar eclipse. The data acquired from each of these sites will be composed into a continuous 90-minute video, allowing the inner solar corona to be studied for an unprecedented length of time.Observations in Indonesia of the March 2016 total solar eclipse allowed initial testing and analysis of the inner corona polar plume dynamics. Using MATLAB, a routine was developed to identify the polar coronal threads and their angle relative to the radial direction to analyze the field line behavior at the boundary of the polar coronal holes.

  3. Study on Horizontally Polarized Omnidirectional Microstrip Antenna

    Directory of Open Access Journals (Sweden)

    Kun Wei


    Full Text Available A horizontally polarized omnidirectional microstrip antenna is proposed in this paper. The structure of designed antenna is with two back-to-back horizontally polarized microstrip antenna elements. Gain variation on main radiation plane of this new antenna is analyzed and radiation theory is deduced; formula of directivity on main radiation plane is given. Better omnidirectional characteristic of this antenna can be obtained by decreasing patch physical length. Both simulated and measured results verify the omnidirectional radiation patterns and input impedance characteristics. Good omnidirectional radiation patterns (gain variation in E-plane less than ±0.4 dBi and input impedance characteristics are obtained; moreover, cross polarization less than −20 dBi is achieved.

  4. [The polarization characteristics distribution and correction method of the polarization coupling error in ocean remote sensing system]. (United States)

    Gao, Jun; Wang, Shu-Peng; Gu, Xing-Fa; Yu, Tao; Fang, Li


    With the development of the quantitative researches using ocean color remote sensing data sets, study on reducing the uncertainty of the response of the ocean color remote sensors to the polarization characteristics of the target has been attracting more and more attention recently. Taking MODIS as an example, the polarization distribution in the whole field of view was analyzed. For the atmosphere path radiance and the apparent radiance considering the coupling between ocean surface and atmosphere, the polarization distribution has a strong relation with the imaging geometry. Compared to the contribution of the polarization from the rough sea surface, the contribution from the atmosphere is dominated. Based on the polarization characteristics in the field of view, the influence of the polarization coupling error on the quality of the satellite data was studied with the assumption of different polarization sensitivities. It was found that errors due to polarization sensitivity in the field of view are lower than water leaving radiance only when the polarization sensitivity is less than 2%. And in this case it can meet the need of the retrieval of water leaving radiative products. The method of the compensation for the polarization coupling error due to the atmosphere is proposed, which proved to be effective to improve the utilization of satellite data and the accuracy of measured radiance by remote sensor.

  5. The physics of polarization (United States)

    Landi Degl'Innocenti, Egidio

    This course is intended to give a description of the basic physical concepts which underlie the study and the interpretation of polarization phenomena. Apart from a brief historical introduction (Sect. 1), the course is organized in three parts. A first part (Sects. 2 - 6) covers the most relevant facts about the polarization phenomena that are typically encountered in laboratory applications and in everyday life. In Sect. 2, the modern description of polarization in terms of the Stokes parameters is recalled, whereas Sect. 3 is devoted to introduce the basic tools of laboratory polarimetry, such as the Jones calculus and the Mueller matrices. The polarization phenomena which are met in the reflection and refraction of a beam of radiation at the separation surface between two dielectrics, or between a dielectric and a metal, are recalled in Sect. 4. Finally, Sect. 5 gives an introduction to the phenomena of dichroism and of anomalous dispersion and Sect. 6 summarizes the polarization phenomena that are commonly encountered in everyday life. The second part of this course (Sects. 7-14) deals with the description, within the formalism of classical physics, of the spectro-polarimetric properties of the radiation emitted by accelerated charges. Such properties are derived by taking as starting point the Liénard and Wiechert equations that are recalled and discussed in Sect. 7 both in the general case and in the non-relativistic approximation. The results are developed to find the percentage polarization, the radiation diagram, the cross-section and the spectral characteristics of the radiation emitted in different phenomena particularly relevant from the astrophysical point of view. The emission of a linear antenna is derived in Sect. 8. The other Sections are devoted to Thomson scattering (Sect. 9), Rayleigh scattering (Sect. 10), Mie scattering (Sect. 11), bremsstrahlung radiation (Sect. 12), cyclotron radiation (Sect. 13), and synchrotron radiation (Sect. 14

  6. 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


    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...

  7. Polarization observables in Virtual Compton Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Doria, Luca


    Virtual Compton Scattering (VCS) is an important reaction for understanding nucleon structure at low energies. By studying this process, the generalized polarizabilities of the nucleon can be measured. These observables are a generalization of the already known polarizabilities and will permit theoretical models to be challenged on a new level. More specifically, there exist six generalized polarizabilities and in order to disentangle them all, a double polarization experiment must be performed. Within this work, the VCS reaction p(e,e'p){gamma} was measured at MAMI using the A1 Collaboration three spectrometer setup with Q{sup 2}=0.33 (GeV/c){sup 2}. Using the highly polarized MAMI beam and a recoil proton polarimeter, it was possible to measure both the VCS cross section and the double polarization observables. Already in 2000, the unpolarized VCS cross section was measured at MAMI. In this new experiment, we could confirm the old data and furthermore the double polarization observables were measured for the first time. The data were taken in five periods between 2005 and 2006. In this work, the data were analyzed to extract the cross section and the proton polarization. For the analysis, a maximum likelihood algorithm was developed together with the full simulation of all the analysis steps. The experiment is limited by the low statistics due mainly to the focal plane proton polarimeter efficiency. To overcome this problem, a new determination and parameterization of the carbon analyzing power was performed. The main result of the experiment is the extraction of a new combination of the generalized polarizabilities using the double polarization observables. (orig.)

  8. A new measurement of electron transverse polarization in polarized nuclear β-decay (United States)

    Kawamura, H.; Akiyama, T.; Hata, M.; Hirayama, Y.; Ikeda, M.; Ikeda, Y.; Ishii, T.; Kameda, D.; Mitsuoka, S.; Miyatake, H.; Nagae, D.; Nakaya, Y.; Ninomiya, K.; Nitta, M.; Ogawa, N.; Onishi, J.; Seitaibashi, E.; Tanaka, S.; Tanuma, R.; Totsuka, Y.; Toyoda, T.; Watanabe, Y. X.; Murata, J.


    The Mott polarimetry for T-violation (MTV) experiment tests time-reversal symmetry in polarized nuclear β-decay by measuring an electron’s transverse polarization as a form of angular asymmetry in Mott scattering using a thin metal foil. A Mott scattering analyzer system developed using a tracking detector to measure scattering angles offers better event selectivity than conventional counter experiments. In this paper, we describe a pilot experiment conducted at KEK-TRIAC using a prototype system with a polarized 8Li beam. The experiment confirmed the sound performance of our Mott analyzer system to measure T-violating triple correlation (R correlation), and therefore recommends its use in higher-precision experiments at the TRIUMF-ISAC.

  9. Acquiring negative polarity items

    NARCIS (Netherlands)

    Lin, J.


    Negative Polarity Items (NPIs) are words or expressions that exhibit a restricted distribution to certain negative contexts only. For example, yet is an NPI and must appear in the scope of a negation: Mary has *(not) finished yet. The existence of NPIs such as yet gives rise to a learnability

  10. Polarized structure functions

    NARCIS (Netherlands)

    Mulders, P.J.G.


    We discuss the spin structure of quarks in hadrons, in particular the transverse spin polarization or transversity. The most direct way to probe transversity appears to be via azimuthal spin asymmetries. This brings in the role of intrinsic transverse momenta of quarks in hadrons and the study of

  11. Political Competition and Polarization

    DEFF Research Database (Denmark)

    Schultz, Christian

    This paper considers political competition and the consequences of political polarization when parties are better informed about how the economy functions than voters are. Specifically, parties know the cost producing a public good, voters do not. An incumbent's choice of policy acts like a signal...

  12. Titan Polar Landscape Evolution (United States)

    Moore, Jeffrey M.


    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.

  13. Acquisition of Oocyte Polarity. (United States)

    Clapp, Mara; Marlow, Florence L


    Acquisition of oocyte polarity involves complex translocation and aggregation of intracellular organelles, RNAs, and proteins, along with strict posttranscriptional regulation. While much is still unknown regarding the formation of the animal-vegetal axis, an early marker of polarity, animal models have contributed to our understanding of these early processes controlling normal oogenesis and embryo development. In recent years, it has become clear that proteins with self-assembling properties are involved in assembling discrete subcellular compartments or domains underlying subcellular asymmetries in the early mitotic and meiotic cells of the female germline. These include asymmetries in duplication of the centrioles and formation of centrosomes and assembly of the organelle and RNA-rich Balbiani body, which plays a critical role in oocyte polarity. Notably, at specific stages of germline development, these transient structures in oocytes are temporally coincident and align with asymmetries in the position and arrangement of nuclear components, such as the nuclear pore and the chromosomal bouquet and the centrioles and cytoskeleton in the cytoplasm. Formation of these critical, transient structures and arrangements involves microtubule pathways, intrinsically disordered proteins (proteins with domains that tend to be fluid or lack a rigid ordered three-dimensional structure ranging from random coils, globular domains, to completely unstructured proteins), and translational repressors and activators. This review aims to examine recent literature and key players in oocyte polarity.

  14. 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...

  15. Precise determination of the degree of polarization of a cold neutron beam (United States)

    Nastoll, H.; Schreckenbach, K.; Baglin, C.; Bussière, A.; Guillaud, J. P.; Kossakowski, R.; Liaud, P.


    A cold neutron beam at the ILL High Flux Reactor was used to produce highly polarized neutrons by means of a bent supermirror polarizer. A following current sheet spin flipper allowed the change of the neutron spin direction relative to the guiding magnetic fields. The degree of polarization of the beam was measured as a function of the neutron velocity in the range 300-1500 m/s achieving an accuracy of 0.2% at typically 98% polarization. Two spin flippers and the permutation of three supermirror polarizers as polarizer/analyzer were employed.

  16. Highly transparent twist polarizer metasurface (United States)

    Faniayeu, Ihar; Khakhomov, Sergei; Semchenko, Igor; Mizeikis, Vygantas


    A twist polarizer metasurface for polarization rotation by an angle of 90 ° is proposed and realized at microwave frequencies. The metasurface consists of sub-wavelength metallic helices arranged periodically in a single layer and operates in transmission geometry with a nearly unity cross-polarization conversion coefficient at resonance. The structure exhibits low reflectivity R polarization orientation of the incident wave. Moreover, it can operate with high efficiency at oblique incidence angles of up to 35 ° . Such twist polarizer metasurfaces are potentially applicable as electromagnetic/optical isolators and frequency-selective polarization antennas.

  17. PM 3655 PHILIPS Logic analyzer

    CERN Multimedia

    A logic analyzer is an electronic instrument that captures and displays multiple signals from a digital system or digital circuit. A logic analyzer may convert the captured data into timing diagrams, protocol decodes, state machine traces, assembly language, or may correlate assembly with source-level software. Logic Analyzers have advanced triggering capabilities, and are useful when a user needs to see the timing relationships between many signals in a digital system.

  18. Enhanced polarization by the coherent heterophase interface between polar and non-polar phases. (United States)

    Kim, Gi-Yeop; Sung, Kil-Dong; Rhyim, Youngmok; Yoon, Seog-Young; Kim, Min-Soo; Jeong, Soon-Jong; Kim, Kwang-Ho; Ryu, Jungho; Kim, Sung-Dae; Choi, Si-Young


    A piezoelectric composite containing the ferroelectric polar (Bi(Na0.8K0.2)0.5TiO3: f-BNKT) and the non-polar (0.94Bi(Na0.75K0.25)0.5TiO3-0.06BiAlO3: BNKT-BA) phases exhibits synergetic properties which combine the beneficial aspects of each phase, i.e., the high saturated polarization (Ps) of the polar phase and the low coercive field (Ec) of the non-polar phase. To understand the origin of such a fruitful outcome from this type of polar/non-polar heterophase structure, comprehensive studies are conducted, including transmission electron microscopy (TEM) and finite element method (FEM) analyses. The TEM results show that the polar/non-polar composite has a core/shell structure in which the polar phase (core) is surrounded by a non-polar phase (shell). In situ electrical biasing TEM experiments visualize that the ferroelectric domains in the polar core are aligned even under an electric field of ∼1 kV mm(-1), which is much lower than its intrinsic coercive field (∼3 kV mm(-1)). From the FEM analyses, we can find that the enhanced polarization of the polar phase is promoted by an additional internal field at the phase boundary which originates from the preferential polarization of the relaxor-like non-polar phase. From the present study, we conclude that the coherent interface between polar and non-polar phases is a key factor for understanding the enhanced piezoelectric properties of the composite.


    NARCIS (Netherlands)



    Just as He-3 --> can be approximately characterized as a polarized neutron target, polarized Li-6D has been advocated as a good isoscalar nuclear target for the extraction of the polarized gluon content of the nucleon. The original argument rests upon a presumed ''alpha + deuteron'' picture of Li-6,

  20. Geomagnetic polarity transitions (United States)

    Merrill, Ronald T.; McFadden, Phillip L.


    The top of Earth's liquid outer core is nearly 2900 km beneath Earth's surface, so we will never be able to observe it directly. This hot, dense, molten iron-rich body is continuously in motion and is the source of Earth's magnetic field. One of the most dynamic manifestations at Earth's surface of this fluid body is, perhaps, a reversal of the geomagnetic field. Unfortunately, the most recent polarity transition occurred at about 780 ka, so we have never observed a transition directly. It seems that a polarity transition spans many human lifetimes, so no human will ever witness the phenomenon in its entirety. Thus we are left with the tantalizing prospect that paleomagnetic records of polarity transitions may betray some of the secrets of the deep Earth. Certainly, if there are systematics in the reversal process and they can be documented, then this will reveal substantial information about the nature of the lowermost mantle and of the outer core. Despite their slowness on a human timescale, polarity transitions occur almost instantaneously on a geological timescale. This rapidity, together with limitations in the paleomagnetic recording process, prohibits a comprehensive description of any reversal transition both now and into the foreseeable future, which limits the questions that may at this stage be sensibly asked. The natural model for the geomagnetic field is a set of spherical harmonic components, and we are not able to obtain a reliable model for even the first few harmonic terms during a transition. Nevertheless, it is possible, in principle, to make statements about the harmonic character of a geomagnetic polarity transition without having a rigorous spherical harmonic description of one. For example, harmonic descriptions of recent geomagnetic polarity transitions that are purely zonal can be ruled out (a zonal harmonic does not change along a line of latitude). Gleaning information about transitions has proven to be difficult, but it does seem

  1. Defining the Polar Field Reversal (United States)

    Upton, Lisa; Hathaway, David H.


    The polar fields on the Sun are directly related to solar cycle variability. Recently there has been interest in studying an important characteristic of the polar fields: the timing of the polar field reversals. However this characteristic has been poorly defined, mostly due to the limitations of early observations. In the past, the reversals have been calculated by averaging the flux above some latitude (i.e. 55deg or 75deg). Alternatively, the reversal could be defined by the time in which the previous polarity is completely canceled and replaced by the new polarity at 90de, precisely at the pole. We will use a surface flux transport model to illustrate the differences in the timing of the polar field reversal based on each of these definitions and propose standardization in the definition of the polar field reversal. The ability to predict the timing of the polar field reversal using a surface flux transport model will also be discussed.

  2. Polarization of a Helium-Neon Laser. (United States)

    Jones, Edwin R.


    Describes an experiment that involves measuring the intensity of laser light passed by a linear polarizer. Discusses polarization effects, orthogonal polarizations, instrumentation, and further experiments. (JRH)

  3. Basis-neutral Hilbert-space analyzers. (United States)

    Martin, Lane; Mardani, Davood; Kondakci, H Esat; Larson, Walker D; Shabahang, Soroush; Jahromi, Ali K; Malhotra, Tanya; Vamivakas, A Nick; Atia, George K; Abouraddy, Ayman F


    Interferometry is one of the central organizing principles of optics. Key to interferometry is the concept of optical delay, which facilitates spectral analysis in terms of time-harmonics. In contrast, when analyzing a beam in a Hilbert space spanned by spatial modes - a critical task for spatial-mode multiplexing and quantum communication - basis-specific principles are invoked that are altogether distinct from that of 'delay'. Here, we extend the traditional concept of temporal delay to the spatial domain, thereby enabling the analysis of a beam in an arbitrary spatial-mode basis - exemplified using Hermite-Gaussian and radial Laguerre-Gaussian modes. Such generalized delays correspond to optical implementations of fractional transforms; for example, the fractional Hankel transform is the generalized delay associated with the space of Laguerre-Gaussian modes, and an interferometer incorporating such a 'delay' obtains modal weights in the associated Hilbert space. By implementing an inherently stable, reconfigurable spatial-light-modulator-based polarization-interferometer, we have constructed a 'Hilbert-space analyzer' capable of projecting optical beams onto any modal basis.

  4. Analyzing data files in SWAN

    CERN Document Server

    Gajam, Niharika


    Traditionally analyzing data happens via batch-processing and interactive work on the terminal. The project aims to provide another way of analyzing data files: A cloud-based approach. It aims to make it a productive and interactive environment through the combination of FCC and SWAN software.

  5. Optically pumped polarized ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Zelenski, A.N.


    Polarization transfer collisions between protons, atomic hydrogen, or deuterium and optically pumped alkali-metal vapour are implemented in the high current optically pumped polarized ion source (OPPIS) and the laser driven source (LDS) of nuclear polarized atoms for target applications. The OPPIS technique overcomes the limitations on intensity of the conventional atomic beam source technique and meets the requirements of the new generation of polarization experiments at multi-GeV accelerators and colliders. 17 refs., 3 figs.

  6. Elite Polarization and Public Opinion

    DEFF Research Database (Denmark)

    Robison, Joshua; Mullinix, Kevin


    Elite polarization has reshaped American politics and is an increasingly salient aspect of news coverage within the United States. As a consequence, a burgeoning body of research attempts to unravel the effects of elite polarization on the mass public. However, we know very little about how polar...... of the consequences of elite polarization—and how polarization is communicated—for public opinion and political behavior in democratic politics....

  7. Polarized and non-polarized leaf reflectances of Coleus blumei (United States)

    Grant, Lois; Daughtry, C. S. T.; Vanderbilt, V. C.


    A polarization photometer has been used to measure the reflectance of three variegated portions of Coleus blumei, Benth. in five wavelength bands of the visible and near-infrared spectrum. The polarized component of the reflectance factor was found to be independent of wavelength, indicating that the polarized reflectance arises from the leaf surface. It is suggested that differences in the polarized component result from variations in surface features. The nonpolarized component of the reflectance factor is shown to be related to the internal leaf structure. The variation of the degree of polarization with wavelength was found to be greatest in the regions of the spectrum where absorption occurs.

  8. Evaluation of extraction protocols for simultaneous polar and non-polar yeast metabolite analysis using multivariate projection methods. (United States)

    Tambellini, Nicolas P; Zaremberg, Vanina; Turner, Raymond J; Weljie, Aalim M


    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.

  9. 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


    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.

  10. Polarization Perception Device (United States)

    Whitehead, Victor S. (Inventor); Coulson, Kinsell L. (Inventor)


    A polarization perception device comprises a base and a polarizing filter having opposite broad sides and a centerline perpendicular thereto. The filter is mounted on the base for relative rotation and with a major portion of the area of the filter substantially unobstructed on either side. A motor on the base automatically moves the filter angularly about its centerline at a speed slow enough to permit changes in light transmission by virtue of such movement to be perceived as light-dark pulses by a human observer, but fast enough so that the light phase of each such pulse occurs prior to fading of the light phase image of the preceding pulse from the observer's retina. In addition to an observer viewing a scene in real time through the filter while it is so angularly moved, or instead of such observation, the scene can be photographed, filmed or taped by a camera whose lens is positioned behind the filter.

  11. PEPPo: Using a Polarized Electron Beam to Produce Polarized Positrons

    Energy Technology Data Exchange (ETDEWEB)

    Adeyemi, Adeleke H. [Hampton Univ., Hampton, VA (United States); et al.


    Polarized positron beams have been identified as either an essential or a significant ingredient for the experimental program of both the present and next generation of lepton accelerators (JLab, Super KEK B, ILC, CLIC). An experiment demonstrating a new method for producing polarized positrons has been performed at the Continuous Electron Beam Accelerator Facility at Jefferson Lab. The PEPPo (Polarized Electrons for Polarized Positrons) concept relies on the production of polarized e⁻/e⁺ pairs from the bremsstrahlung radiation of a longitudinally polarized electron beam interacting within a high-Z conversion target. PEPPo demonstrated the effective transfer of spin-polarization of an 8.2 MeV/c polarized (P~85%) electron beam to positrons produced in varying thickness tungsten production targets, and collected and measured in the range of 3.1 to 6.2 MeV/c. In comparison to other methods this technique reveals a new pathway for producing either high-energy or thermal polarized positron beams using a relatively low polarized electron beam energy (~10MeV) .This presentation will describe the PEPPo concept, the motivations of the experiment and high positron polarization achieved.

  12. Polar bears, Ursus maritimus (United States)

    Rode, Karyn D.; Stirling, Ian


    Polar bears are the largest of the eight species of bears found worldwide and are covered in a pigment-free fur giving them the appearance of being white. They are the most carnivorous of bear species consuming a high-fat diet, primarily of ice-associated seals and other marine mammals. They range throughout the circumpolar Arctic to the southernmost extent of seasonal pack ice.

  13. Polarization induced doped transistor (United States)

    Xing, Huili; Jena, Debdeep; Nomoto, Kazuki; Song, Bo; Zhu, Mingda; Hu, Zongyang


    A nitride-based field effect transistor (FET) comprises a compositionally graded and polarization induced doped p-layer underlying at least one gate contact and a compositionally graded and doped n-channel underlying a source contact. The n-channel is converted from the p-layer to the n-channel by ion implantation, a buffer underlies the doped p-layer and the n-channel, and a drain underlies the buffer.

  14. Ultracold Polar Molecules (United States)


    formation of ultracold 87RbCs molecules in their rovibrational ground state by magnetoassociation followed by STIRAP, resulting in 14 papers acknowledging...produce at high densities. We revealed broad Feshbach resonances that we hope will allow production of higher-density 85Rb clouds. We are now...attempting to achieve the next step, formation of 85RbCs molecules. 15. SUBJECT TERMS EOARD, ultracold polar molecules, Feshbach resonance 16. SECURITY

  15. Multifrequency Behaviour of Polars

    Directory of Open Access Journals (Sweden)

    K. Reinsch


    Full Text Available Cataclysmic variables emit over a wide range of the electromagnetic spectrum. In this paper I will review observations of polars in relevant passbands obtained during the last decade and will discuss their diagnostical potential to access the physics of the main components within the binary systems. This will include a discussion of intrinsic source variability and the quest for simultaneous multi-frequency observations.

  16. Polar Business Design

    Directory of Open Access Journals (Sweden)

    Sébastien Caisse


    Full Text Available Polar business design aims to enable entrepreneurs, managers, consultants, researchers, and business students to better tackle model-based analysis, creation, and transformation of businesses, ventures, and, more generically, collective endeavors of any size and purpose. It is based on a systems-thinking approach that builds on a few interrelated core concepts to create holistic visual frameworks. These core concepts act as poles linked by meaningful dyads, flows, and faces arranged in geometric shapes. The article presents two such polar frameworks as key findings in an ongoing analytic autoethnography: the three-pole Value−Activity−Stakeholder (VAS triquetra and the four-pole Offer−Creation−Character−Stakeholder (OCCS tetrahedron. The VAS triquetra is a more aggregated model of collective endeavors. The OCCS tetrahedron makes a trade-off between a steeper learning curve and deeper, richer representation potential. This article discusses how to use these two frameworks as well as their limits, and explores the potential that polar business design offers for future research.

  17. Polarization of Prompt Muons

    Energy Technology Data Exchange (ETDEWEB)

    Lauterbach, Michael J. [Yale U.


    This paper presents measurements of the polarization of muons produced very near the point of proton - nucleon interaction" The experiment utilized a 400 GeV proton beam available in the Proton Central area of Fermilab. Muons were produced by the interaction of these protons with a variable density copper target" Extrapolation to infinite target density allowed elilp.ination of contributions due to muons from meson decay" Measurements were made upon muons produced in the forward direction with energies near 185 GeV and upon muons produced with transverse momenta near 1. 9 Ge V / c and an energy of 54 Ge V" In the first case only the longitudinal polarization was measured: P = - 0.01 ± 0.14. Under the second set of kinematic conditions both the longitudinal and transverse polarization were measured: $P_L$ = - 0.06 ± 0.16, $P_T$ = - 0.01 ± O.11 These null measurements suggest that an electromagnetic process is the dominant mechanism for prompt muon production" The measurements also indicate an upper limit of $B_{\\mu} ( D^0) \\sigma_{D^0} + B_{\\mu} ( D^+) \\sigma_{D^+} < 6.7 x 10^{-8}$ barns may be placed upon the production cross section for D particles

  18. Linear Polarization Properties of Parsec-Scale AGN Jets

    Directory of Open Access Journals (Sweden)

    Alexander B. Pushkarev


    Full Text Available We used 15 GHz multi-epoch Very Long Baseline Array (VLBA polarization sensitive observations of 484 sources within a time interval 1996–2016 from the MOJAVE program, and also from the NRAO data archive. We have analyzed the linear polarization characteristics of the compact core features and regions downstream, and their changes along and across the parsec-scale active galactic nuclei (AGN jets. We detected a significant increase of fractional polarization with distance from the radio core along the jet as well as towards the jet edges. Compared to quasars, BL Lacs have a higher degree of polarization and exhibit more stable electric vector position angles (EVPAs in their core features and a better alignment of the EVPAs with the local jet direction. The latter is accompanied by a higher degree of linear polarization, suggesting that compact bright jet features might be strong transverse shocks, which enhance magnetic field regularity by compression.

  19. Wavelet analysis of polarization maps of polycrystalline biological fluids networks (United States)

    Ushenko, Y. A.


    The optical model of human joints synovial fluid is proposed. The statistic (statistic moments), correlation (autocorrelation function) and self-similar (Log-Log dependencies of power spectrum) structure of polarization two-dimensional distributions (polarization maps) of synovial fluid has been analyzed. It has been shown that differentiation of polarization maps of joint synovial fluid with different physiological state samples is expected of scale-discriminative analysis. To mark out of small-scale domain structure of synovial fluid polarization maps, the wavelet analysis has been used. The set of parameters, which characterize statistic, correlation and self-similar structure of wavelet coefficients' distributions of different scales of polarization domains for diagnostics and differentiation of polycrystalline network transformation connected with the pathological processes, has been determined.

  20. Direct determination of actin polarity in the cell. (United States)

    Narita, Akihiro; Mueller, Jan; Urban, Edit; Vinzenz, Marlene; Small, J Victor; Maéda, Yuichiro


    Actin filaments are polar structures that exhibit a fast growing plus end and a slow growing minus end. According to their organization in cells, in parallel or antiparallel arrays, they can serve, respectively, in protrusions or in contractions. The determination of actin filament polarity in subcellular compartments is therefore required to establish their local function. Myosin binding has previously been the sole method of polarity determination. Here, we report the first direct determination of actin filament polarity in the cell without myosin binding. Negatively stained cytoskeletons of lamellipodia were analyzed by adapting electron tomography and a single particle analysis for filamentous complexes. The results of the stained cytoskeletons confirmed that all actin filament ends facing the cell membrane were the barbed ends. In general, this approach should be applicable to the analysis of actin polarity in tomograms of the actin cytoskeleton. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Transient behavior of carbon nanotube thin film for adsorption of polar and non-polar molecules (United States)

    Tomita, Yoshihiro; Inoue, Shuhei; Matsumura, Yukihiko


    Application of carbon nanotube (CNT) film as a gas sensor is highly desired. Transient behavior of molecular adsorption provides adsorption and desorption constants; however, to date, few researchers have investigated it. Here, we focused on the transient behavior of electric conductance of the CNT film during adsorption. Adsorption of polar molecules showed predicable behavior, but non-polar molecules showed a sudden change of electric conductance that indicated excess adsorption. We analyzed the process based on Langmuir adsorption, and adsorption and desorption constants, which are considered to be physical properties; however, these parameters did not show good agreement for the same film.

  2. CSTT Update: Fuel Quality Analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Brosha, Eric L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lujan, Roger W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mukundan, Rangachary [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rockward, Tommy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Romero, Christopher J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Williams, Stefan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wilson, Mahlon S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    These are slides from a presentation. The following topics are covered: project background (scope and approach), developing the prototype (timeline), update on intellectual property, analyzer comparisons (improving humidification, stabilizing the baseline, applying clean-up strategy, impact of ionomer content and improving clean-up), proposed operating mode, considerations for testing in real-world conditions (Gen 1 analyzer electronics development, testing partner identified, field trial planning), summary, and future work.

  3. Polarized absorption in determination of impurities in olive oil (United States)

    Alias, A. N.; Zabidi, Z. M.; Yaacob, Y.; Amir, I. S.; Alshurdin, S. H. N.; Aini, N. A.


    The effect of impurities in olive oil blending with palm oil was characterized using polarized absorption method. Polarized absorption was based on the absorption of light which vibrating in a particular plane to pass through the sample. This polarized light allowed the molecule to absorb at the specific orientation. There were four samples have been prepared that were 100:0, 70:30, 50:50 and 0:100 with volume ratio of the olives to palm oil. Two linear polarizers were mounting between the samples in order to get linearly polarized. This specific orientation was affected the absorption spectra of the sample. The results have shown that the analyzing polarizer with angle 00 has bell shape spectra. All the orientation of analyzing polarizer had shown the maximum current output at 100% olive oil. Whereas 100% palm oil has shown the minimum current output. The changing in absorption spectra indicates that the anisotropic properties of each sample were different due to the present of impurities.

  4. Polar bear attacks on humans: Implications of a changing climate (United States)

    Wilder, James; Vongraven, Dag; Atwood, Todd C.; Hansen, Bob; Jessen, Amalie; Kochnev, Anatoly A.; York, Geoff; Vallender, Rachel; Hedman, Daryll; Gibbons, Melissa


    Understanding causes of polar bear (Ursus maritimus) attacks on humans is critical to ensuring both human safety and polar bear conservation. Although considerable attention has been focused on understanding black (U. americanus) and grizzly (U. arctos) bear conflicts with humans, there have been few attempts to systematically collect, analyze, and interpret available information on human-polar bear conflicts across their range. To help fill this knowledge gap, a database was developed (Polar Bear-Human Information Management System [PBHIMS]) to facilitate the range-wide collection and analysis of human-polar bear conflict data. We populated the PBHIMS with data collected throughout the polar bear range, analyzed polar bear attacks on people, and found that reported attacks have been extremely rare. From 1870–2014, we documented 73 attacks by wild polar bears, distributed among the 5 polar bear Range States (Canada, Greenland, Norway, Russia, and United States), which resulted in 20 human fatalities and 63 human injuries. We found that nutritionally stressed adult male polar bears were the most likely to pose threats to human safety. Attacks by adult females were rare, and most were attributed to defense of cubs. We judged that bears acted as a predator in most attacks, and that nearly all attacks involved ≤2 people. Increased concern for both human and bear safety is warranted in light of predictions of increased numbers of nutritionally stressed bears spending longer amounts of time on land near people because of the loss of their sea ice habitat. Improved conflict investigation is needed to collect accurate and relevant data and communicate accurate bear safety messages and mitigation strategies to the public. With better information, people can take proactive measures in polar bear habitat to ensure their safety and prevent conflicts with polar bears. This work represents an important first step towards improving our understanding of factors influencing

  5. Snapshot imaging Mueller matrix polarimeter using polarization gratings. (United States)

    Kudenov, Michael W; Escuti, Michael J; Hagen, Nathan; Dereniak, Eustace L; Oka, Kazuhiko


    A snapshot imaging Mueller matrix polarimeter (SIMMP) is theoretically described and empirically demonstrated through simulation. Spatial polarization fringes are localized onto a sample by incorporating polarization gratings (PGs) into a polarization generator module. These fringes modulate the Mueller matrix (MM) components of the sample, which are subsequently isolated with PGs in an analyzer module. The MM components are amplitude modulated onto spatial carrier frequencies which, due to the PGs, maintain high visibility in spectrally broadband illumination. An interference model of the SIMMP is provided, followed by methods of reconstruction and calibration. Lastly, a numerical simulation is used to demonstrate the system's performance in the presence of noise. © 2012 Optical Society of America

  6. Polarization spectroscopy of atomic erbium in a hollow cathode lamp (United States)

    Ang’ong’a, Jackson; Gadway, Bryce


    In this work we perform polarization spectroscopy of erbium atoms in a hollow cathode lamp (HCL). We review the theory behind Doppler-free polarization spectroscopy, theoretically model the expected erbium polarization spectra, and compare the numerically calculated spectra to our experimental data. We further analyze the dependence of the measured spectra on the HCL current and the peak intensities of our pump and probe lasers to determine conditions. Applications include wavelength stabilization of diode laser radiation to the 400.91 nm erbium transition.

  7. On-Demand Urine Analyzer (United States)

    Farquharson, Stuart; Inscore, Frank; Shende, Chetan


    A lab-on-a-chip was developed that is capable of extracting biochemical indicators from urine samples and generating their surface-enhanced Raman spectra (SERS) so that the indicators can be quantified and identified. The development was motivated by the need to monitor and assess the effects of extended weightlessness, which include space motion sickness and loss of bone and muscle mass. The results may lead to developments of effective exercise programs and drug regimes that would maintain astronaut health. The analyzer containing the lab-on-a- chip includes materials to extract 3- methylhistidine (a muscle-loss indicator) and Risedronate (a bone-loss indicator) from the urine sample and detect them at the required concentrations using a Raman analyzer. The lab-on- a-chip has both an extractive material and a SERS-active material. The analyzer could be used to monitor the onset of diseases, such as osteoporosis.

  8. Circularly polarized antennas

    CERN Document Server

    Gao, Steven; Zhu, Fuguo


    This book presents a comprehensive insight into the design techniques for different types of CP antenna elements and arrays In this book, the authors address a broad range of topics on circularly polarized (CP) antennas. Firstly, it introduces to the reader basic principles, design techniques and characteristics of various types of CP antennas, such as CP patch antennas, CP helix antennas, quadrifilar helix antennas (QHA), printed quadrifilar helix antennas (PQHA), spiral antenna, CP slot antennas, CP dielectric resonator antennas, loop antennas, crossed dipoles, monopoles and CP horns. Adva

  9. On polarization in biomembranes

    DEFF Research Database (Denmark)

    Zecchi, Karis Amata

    close to physiological conditions, making these effects biologically relevant. In this work, we consider the case of asymmetric membranes which can display spontaneous polarization in the absence of a field. Close to the phase transition, we find that the membrane displays piezoelectric, flexoelectric...... several electrical behaviours similar to those measured for biological membranes and considered to be distinctive features of protein channels, like outward rectification and gating currents. Finally, our proposed equivalent model is suggested by the structure and physical properties of the system...

  10. Plasma polarization spectroscopy

    CERN Document Server

    Iwamae, Atsushi


    Plasma Polarization Spectroscopy (PPS) is now becoming a standard diagnostic technique for working with laboratory plasmas. This new area needs a comprehensive framework, both experimental and theoretical. This book reviews the historical development of PPS, develops a general theoretical formulation to deal with this phenomenon, along with an overview of relevant cross sections, and reports on laboratory experiments so far performed. It also includes various facets that are interesting from this standpoint, e.g. X-ray lasers and effects of microwave irradiation. It also offers a timely discussion of instrumentation that is quite important in a practical PPS experiment.

  11. Polarization mode dispersion effects on phase and polarization diversity receivers (United States)

    Pratt, Thomas G.; Ingram, Mary Ann


    The objective of this paper is to examine the combined effects of weak phase noise and polarization mode dispersion (PMD) on a coherent receiver employing phase and polarization diversity reception. The receiver is assumed to be subjected to the following: transmitter and receiver polarization misalignment relative to the principal states of the optical fiber, phase noise, polarization mode dispersion, and shot noise. The receiver outputs are investigated for ASK demodulation using square-law and envelope detection. The results show that for the assumed receiver configuration, square law detection provides an output which is independent of PMD, phase noise, and polarization misalignment. Envelope detection results in a receiver output which is dependent on all of these parameters. Furthermore, when phase noise and PMD are simultaneously present, the resulting probability of bit error is no greater than the probability of bit error under worst-case operating conditions when polarization mode dispersion and phase noise are absent.

  12. Coronal Polarization of Pseudostreamers and the Solar Polar Field Reversal (United States)

    Rachmeler, L. A.; Guennou, C.; Seaton, D. B.; Gibson, S. E.; Auchere, F.


    The reversal of the solar polar magnetic field is notoriously hard to pin down due to the extreme viewing angle of the pole. In Cycle 24, the southern polar field reversal can be pinpointed with high accuracy due to a large-scale pseudostreamer that formed over the pole and persisted for approximately a year. We tracked the size and shape of this structure with multiple observations and analysis techniques including PROBA2/SWAP EUV images, AIA EUV images, CoMP polarization data, and 3D tomographic reconstructions. We find that the heliospheric field reversed polarity in February 2014, whereas in the photosphere, the last vestiges of the previous polar field polarity remained until March 2015. We present here the evolution of the structure and describe its identification in the Fe XII 1074nm coronal emission line, sensitive to the Hanle effect in the corona.

  13. Infrared small target detection method based on decomposition of polarization information (United States)

    Zhang, Yan; Shi, Zhi-Guang; Qiu, Tiao-Wen


    A method of feature extraction and small target detection, based on infrared polarization, which uses the technical superiority of infrared polarization imaging in artificial target detection to solve the clutter interference problem in infrared target detection, is proposed. First, using the differences in the polarization characteristics of the artificial target and the natural background, the infrared polarization information models for the target and background are established. The compositions of intensity information, polarization information, and target polarization information are extracted, and enhancement measures are analyzed. Then, the variable polarization theories are combined to extract the target polarization characteristics and suppress the background clutter. Finally, the infrared small target is detected, and comparisons with existing methods demonstrate the effectiveness and reliability of the proposed method.

  14. Polar Rain Gradients and Field-Aligned Polar Cap Potentials (United States)

    Fairfield, D. H.; Wing, S.; Newell, P. T.; Ruohoniemi, J. M.; Gosling, J. T.; Skoug, R. M.


    ACE SWEPAM measurements of solar wind field-aligned electrons have been compared with simultaneous measurements of polar rain electrons precipitating over the polar cap and detected by DMSP spacecraft. Such comparisons allow investigation of cross-polarcap gradients in the intensity of otherwise-steady polar rain. The generally good agreement of the distribution functions, f, from the two data sources confirms that direct entry of solar electrons along open field lines is indeed the cause of polar rain. The agreement between the data sets is typically best on the side of the polar cap with most intense polar rain but the DMSP f's in less intense regions can be brought into agreement with ACE measurements by shifting all energies by a fixed amounts that range from tens to several hundred eV. In most cases these shifts are positive which implies that field-aligned potentials of these amounts exist on polar cap field lines which tend to retard the entry of electrons and produce the observed gradients. These retarding potentials undoubtedly appear in order to prevent the entry of low-energy electrons and maintain charge quasi-neutrality that would otherwise be violated since most tailward flowing magnetosheath ions are unable to follow polar rain electrons down to the polar cap. In more limited regions near the boundary of the polar cap there is sometimes evidence for field-aligned potentials of the opposite sign that accelerate polar rain electrons. A solar electron burst is also studied and it is concluded that electrons from such bursts can enter the magnetotail and precipitate in the same manner as polar rain.

  15. Polar bear management in Alaska 1997-2000 (United States)

    Schliebe, Scott L.; Bridges, John W.; Evans, Thomas J.; Fischbach, Anthony S.; Kalxdorff, Susanne B.; Lierheimer, Lisa J.; Lunn, Nicholas J.; Schliebe, Scott L.; Born, Erik W.; Lunn, Nicholas J.; Schliebe, Scott L.; Born, Erik W.


    the harvest of polar bears in Alaska and collect and analyze specimens for presence and level of organochlorine compounds and trace elements. A paper on genetic assessment of hunter reported sex of harvested bears was recently published (Schliebe et al. 1999). Population status and trend assessment efforts continued. An aerial survey of polar bears in the Eastern Chukchi Sea and western portions of the Southern Beaufort Sea was conducted from the U.S. Coast Guard icebreaker “Polar Star” in August 2000. The first year of a multi-year survey of barrier islands and coastlines during the open water and freeze-up phase was conducted in the central Southern Beaufort Sea during fall 2000.

  16. Software-Design-Analyzer System (United States)

    Tausworthe, Robert C.


    CRISP-90 software-design-analyzer system, update of CRISP-80, is set of computer programs constituting software tool for design and documentation of other software and supporting top-down, hierarchical, modular, structured methodologies for design and programming. Written in Microsoft QuickBasic.

  17. Analyzing Software Piracy in Education. (United States)

    Lesisko, Lee James

    This study analyzes the controversy of software piracy in education. It begins with a real world scenario that presents the setting and context of the problem. The legalities and background of software piracy are explained and true court cases are briefly examined. Discussion then focuses on explaining why individuals and organizations pirate…

  18. Methods of analyzing crude oil (United States)

    Cooks, Robert Graham; Jjunju, Fred Paul Mark; Li, Anyin; Rogan, Iman S.


    The invention generally relates to methods of analyzing crude oil. In certain embodiments, methods of the invention involve obtaining a crude oil sample, and subjecting the crude oil sample to mass spectrometry analysis. In certain embodiments, the method is performed without any sample pre-purification steps.

  19. Analyzing Student Difficulties in Reading. (United States)

    Ediger, Marlow

    According to this paper, a good reading teacher is able to analyze problems faced by students in reading and remediate that which is necessary. The paper stresses that the reading teacher needs to be a good observer of student reading habits to notice where to intervene to improve the skills and attitudes of the reader. It discusses diagnosis and…

  20. Polarized proton collider at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanaka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Lehrach, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S.Y.; Luccio, A.; MacKay, W.W. E-mail: mackay@bnl.gov; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A.N


    In addition to heavy ion collisions (RHIC Design Manual, Brookhaven National Laboratory), RHIC will also collide intense beams of polarized protons (I. Alekseev, et al., Design Manual Polarized Proton Collider at RHIC, Brookhaven National Laboratory, 1998, reaching transverse energies where the protons scatter as beams of polarized quarks and gluons. The study of high energy polarized protons beams has been a long term part of the program at BNL with the development of polarized beams in the Booster and AGS rings for fixed target experiments. We have extended this capability to the RHIC machine. In this paper we describe the design and methods for achieving collisions of both longitudinal and transverse polarized protons in RHIC at energies up to {radical}s=500 GeV.

  1. Yb-doped polarizing fiber (United States)

    Gillooly, A.; Webb, A. S.; Favero, F. C.; Bouchan, T.; Cooper, L. J.; Read, D.; Hill, M.


    An ytterbium (Yb) doped polarizing fiber is demonstrated. The fiber offers the opportunity to build all-fiber lasers with single polarization output and without the need for free-space polarizing components. Traditional single polarization fiber lasers utilize polarization-maintaining (PM) gain fiber with a single polarization stimulation signal. Whilst this results in an approximation to a single polarization laser, the spontaneous emission from the unstimulated polarization state limits the polarization extinction ratio (PER). The PER is further limited as the stimulated signal is prone to crosstalk. Furthermore, controlling amplitude modulation of the stimulated signal is critical for maximizing the peak power of an optical pulse, particularly for high energy lasers. If light is allowed to leak in to the unstimulated axis it will travel at a different velocity to the stimulated axis and can cross-couple back into the signal axis, creating an interference effect which leads to amplitude modulation on the signal pulse. Single-polarization Yb-doped fiber ensures that light on the fast axis is constantly attenuated; ensuring that light on the unstimulated axis cannot propagate and thus cannot degrade the PER or create amplitude modulation. In this paper we report on, to the best of our knowledge, the first demonstration of a single polarization Yb-doped bowtie optical fiber manufactured using a combination of Modified Chemical Vapor Deposition (MCVD) and rare-earth solution doping technology. The fiber has a single-polarization window of 80nm at the operating wavelength of 1060nm and a PER of >18dB. The fabrication and characterization of the fiber is reported.

  2. Polarity in Mammalian Epithelial Morphogenesis


    Roignot, Julie; Peng, Xiao; Mostov, Keith


    Cell polarity is fundamental for the architecture and function of epithelial tissues. Epithelial polarization requires the intervention of several fundamental cell processes, whose integration in space and time is only starting to be elucidated. To understand what governs the building of epithelial tissues during development, it is essential to consider the polarization process in the context of the whole tissue. To this end, the development of three-dimensional organotypic cell culture model...

  3. Methods for Analyzing Social Media

    DEFF Research Database (Denmark)

    Jensen, Jakob Linaa; [Ukendt], editors


    new questions such as: How can we analyze social media? Can we use traditional audience research methods and apply them to online content? Which new research strategies have been developed? Which ethical research issues and controversies do we have to pay attention to? This book focuses on research......Social media is becoming increasingly attractive for users. It is a fast way to communicate ideas and a key source of information. It is therefore one of the most influential mediums of communication of our time and an important area for audience research. The growth of social media invites many...... strategies and methods for analyzing social media and will be of interest to researchers and practitioners using social media, as well as those wanting to keep up to date with the subject....

  4. Image analyzers for bioscience applications. (United States)

    Ramm, P


    Image analysis systems are becoming more sophosticated, less costly, and very common in research laboratories. Therefore, the bioscience researcher is faced with a bewildering array of choices in establishing an image analysis facility. Critical components and characteristics of commercial image analyzers are discussed. State-of-the-art systems feature a graphical user interface, a powerful operating system (e.g., Microsoft OS/2), 1000 line image acquisition, processing and display, true color imaging, and very flexible scanner interfaces. Such systems are best suited to technically difficult applications, such as ratio fluorescence, or to automated analysis of anatomical features, particularly in stained material. Less powerful image analyzers offer medium resolution, and typically work with monochrome data acquired from video cameras. Such systems are suitable for many bioscience applications, including quantitative autoradiography and routine morphometry.

  5. Methods for Analyzing Social Media

    DEFF Research Database (Denmark)

    Jensen, Jakob Linaa


    Social media is becoming increasingly attractive for users. It is a fast way to communicate ideas and a key source of information. It is therefore one of the most influential mediums of communication of our time and an important area for audience research. The growth of social media invites many...... new questions such as: How can we analyze social media? Can we use traditional audience research methods and apply them to online content? Which new research strategies have been developed? Which ethical research issues and controversies do we have to pay attention to? This book focuses on research...... strategies and methods for analyzing social media and will be of interest to researchers and practitioners using social media, as well as those wanting to keep up to date with the subject....

  6. Determination of deuteron beam polarizations at COSY

    Directory of Open Access Journals (Sweden)

    D. Chiladze


    Full Text Available The vector (P_{z} and tensor (P_{zz} polarizations of a deuteron beam have been measured using elastic deuteron–carbon scattering at 75.6 MeV and deuteron-proton scattering at 270 MeV. After acceleration to 1170 MeV inside the COSY storage ring, the polarizations of the deuterons were remeasured by studying the analyzing powers of a variety of nuclear reactions. For this purpose a hydrogen cluster target was employed at the ANKE magnetic spectrometer, which is situated at an internal target position in the ring. The overall precisions obtained were about 4% for both P_{z} and P_{zz}. Though all the measurements were consistent with the absence of depolarization during acceleration, only an upper limit of about 6% could be placed on such an effect.

  7. Polarized triple-axis spectrometer TASP

    Energy Technology Data Exchange (ETDEWEB)

    Boeni, P.; Keller, P. [Lab. for Neutron Scattering ETH Zurich, Zurich (Switzerland) and Paul Scherrer Institute, Villigen (Switzerland)


    The polarized triple-axis spectrometer TASP at SINQ has been optimized for measuring magnetic cross sections in condensed matter. The neutrons are polarized or analyzed either by means of benders or Heusler monochromators. The beam divergence, i.e. the intensity, and the spectral range of the neutrons is rather large because of the supermirror coatings of the feeding neutron guide. The intensity can be further increased at the sample position by means of a focussing monochromator and a focussing anti-trumpet. The end position of TASP allows the tailoring of the neutron beam already before the monochromator and to scatter neutrons over very wide ranges of angles. (author) 6 figs., 1 tab., 8 refs.

  8. Analyzing Change Management in Organization


    Yonardy, Charles; Mekel, Peggy A.


    Every company will be faced a change either business or non-business company. A change will be happened because of technological change, industry change, and institutional rules change. If the company lack in adapt the changing of competition, business cycles, technology and institutional rules the company might face a bankruptcy. Why? To make a successful change there are steps and process of change. Research objectives are to analyze what should company do in order to do change management a...

  9. Remote Laser Diffraction PSD Analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Batcheller, Thomas Aquinas; Huestis, Gary Michael; Bolton, Steven Michael


    Particle size distribution (PSD) analysis of radioactive slurry samples were obtained using a modified "off-the-shelf" classical laser light scattering particle size analyzer. A Horiba Instruments Inc. Model La-300 PSD analyzer, which has a 0.1 to 600 micron measurement range, was modified for remote application in a "hot cell" (gamma radiation) environment. The general details of the modifications to this analyzer are presented in this paper. This technology provides rapid and simple PSD analysis, especially down in the fine and microscopic particle size regime. Particle size analysis of these radioactive slurries down in this smaller range was not achievable - making this technology far superior than the traditional methods used previously. Remote deployment and utilization of this technology is in an exploratory stage. The risk of malfunction in this radiation environment is countered by gaining of this tremendously useful fundamental engineering data. Successful acquisition of this data, in conjunction with other characterization analyses, provides important information that can be used in the myriad of potential radioactive waste management alternatives.

  10. Sulfur Dioxide Analyzer Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Springston, Stephen R. [Brookhaven National Lab. (BNL), Upton, NY (United States)


    The Sulfur Dioxide Analyzer measures sulfur dioxide based on absorbance of UV light at one wavelength by SO2 molecules which then decay to a lower energy state by emitting UV light at a longer wavelength. Specifically, SO2 + hυ1 →SO2 *→SO2 + hυ2 The emitted light is proportional to the concentration of SO2 in the optical cell. External communication with the analyzer is available through an Ethernet port configured through the instrument network of the AOS systems. The Model 43i-TLE is part of the i-series of Thermo Scientific instruments. The i-series instruments are designed to interface with external computers through the proprietary Thermo Scientific iPort Software. However, this software is somewhat cumbersome and inflexible. Brookhaven National Laboratory (BNL) has written an interface program in National Instruments LabView that both controls the Model 43i-TLE Analyzer AND queries the unit for all measurement and housekeeping data. The LabView vi (the software program written by BNL) ingests all raw data from the instrument and outputs raw data files in a uniform data format similar to other instruments in the AOS and described more fully in Section 6.0 below.

  11. Polarization-preserving holey fibers

    DEFF Research Database (Denmark)

    Broeng, Jes; Mogilevtsev, Dmitri; Libori, Stig E. Barkou


    In this work we suggest and discuss a microstructure of air capillaries with elliptical cross-section in a tread of glass that gives opportunity for Creation of polarization-preserving fiber with very small beat length between the fundamental modes of different polarization......In this work we suggest and discuss a microstructure of air capillaries with elliptical cross-section in a tread of glass that gives opportunity for Creation of polarization-preserving fiber with very small beat length between the fundamental modes of different polarization...

  12. Polarization preservation in the AGS

    Energy Technology Data Exchange (ETDEWEB)

    Ratner, L.G.


    The successful operation of a high energy polarized beam at the Argonne Zero Gradient Synchrotron (ZGS) with the concommitant development of depolarizing resonance correction techniques has led to the present project of commissioning such a beam at the Brookhaven Alternating Gradient Synchrotron (AGS). A description of the project was presented at the 1981 National Accelerator Conference. I would like to now present a more detailed description of how we plan to preserve the polarization during acceleration, and to present our game plan for tuning through some 50 resonances and reaching our goal of a 26 GeV polarized proton beam with greater than 60% polarization.

  13. Magnet polarities in the LHC

    CERN Document Server

    McAteer, M; Maclean, E; Persson, T; Steinhagen, R; Tomas, R


    We report the results of extensive tests to verify the polarities of Landau damping octupoles (MOF, MOD) and octupole spool correctors (MCO), arc trim skew sextupoles (MSS), and triplet sextupole correctors (MCSX and MCSSX). All octupole circuits that were measured were found to have the expected polarity. All arc skew sextupoles MSS and triplet sextupole correctors MCSX and MCSSX that were measured were found to have reversed polarity with respect to MADX. It is also noted that the triplet quadrupole trims ktqx2, as well as MQS and MQSX, have reversed polarity with respect to MADX.

  14. Analyzing Big Data in Psychology: A Split/Analyze/Meta-Analyze Approach

    Directory of Open Access Journals (Sweden)

    Mike W.-L. Cheung


    Full Text Available Big data is a field that has traditionally been dominated by disciplines such as computer science and business, where mainly data-driven analyses have been performed. Psychology, a discipline in which a strong emphasis is placed on behavioral theories and empirical research, has the potential to contribute greatly to the big data movement. However, one challenge to psychologists – and probably the most crucial one – is that most researchers may not have the necessary programming and computational skills to analyze big data. In this study we argue that psychologists can also conduct big data research and that, rather than trying to acquire new programming and computational skills, they should focus on their strengths, such as performing psychometric analyses and testing theories using multivariate analyses to explain phenomena. We propose a split/analyze/meta-analyze approach that allows psychologists to easily analyze big data. Two real datasets are used to demonstrate the proposed procedures in R. A new research agenda related to the analysis of big data in psychology is outlined at the end of the study.

  15. Analyzing Big Data in Psychology: A Split/Analyze/Meta-Analyze Approach. (United States)

    Cheung, Mike W-L; Jak, Suzanne


    Big data is a field that has traditionally been dominated by disciplines such as computer science and business, where mainly data-driven analyses have been performed. Psychology, a discipline in which a strong emphasis is placed on behavioral theories and empirical research, has the potential to contribute greatly to the big data movement. However, one challenge to psychologists-and probably the most crucial one-is that most researchers may not have the necessary programming and computational skills to analyze big data. In this study we argue that psychologists can also conduct big data research and that, rather than trying to acquire new programming and computational skills, they should focus on their strengths, such as performing psychometric analyses and testing theories using multivariate analyses to explain phenomena. We propose a split/analyze/meta-analyze approach that allows psychologists to easily analyze big data. Two real datasets are used to demonstrate the proposed procedures in R. A new research agenda related to the analysis of big data in psychology is outlined at the end of the study.

  16. A lunar polar expedition. (United States)

    Dowling, Richard; Staehle, Robert L.; Svitek, Thomas

    This paper reviews issues related to a five-person expedition to the lunar north pole which primarily addresses site selection and the requirements for transportation, power, and life support. A one-year stay on the lunar surface is proposed based on available technology, and proposals are detailed for incorporating flight-proven systems, abort or rescue options, and the use of the base as the nucleus for subsequent operations. Specific details are given regarding lunar orbital data, the characteristics of the proposed base, power and consumables requirements, and equipment such as two-person lunar roving vehicles and space suits. During the expedition: (1) water is recycled; (2) Autolanders are used to deliver equipment; (3) two rovers are included in the mass budget; (4) the lunar surface is studied in detail. A polar lunar-base site offers the advantages of unobstructed astronomy, enhanced heat rejection, and the potential for reuse.

  17. About a linear polarization of comets: The phase-angle dependences of polarization degree (United States)

    Shestopalov, D. I.; Golubeva, L. F.


    The ground-based astronomic observations of comet cannot provide a proper phase angle coverage that is needed to estimate with a reasonable accuracy all of the attributes of comet polarization phase curve. To find the best approximation to the phase polarization dependences observed for comets, we apply a simple empiric formula that has already shown good results when operating with asteroid and lunar polarimetric curves (Shestopalov, 2004; Shestopalov and Golubeva, 2015). From the set of comets present in DBCP (Kiselev et al., 2006), we selected 20, for which the calculation of regular polarimetric curves (i.e. the phase angle - polarization dependences with a low level of nonsteady activity) was possible. Within the phase angle coverage area for these 20 comets, a potential user can reproduce 82 best-fitting polarimetric phase curves in various spectral domains. Then we analyzed the properties of negative and positive polarization of the comets. The interrelation between the averaged polarimetric slope h at the inversion angle and wavelength was found. In general, the parameters of negative branch vary slightly from one comet to another. We found a close correlation between the maximum polarization degree Pmax and the slope of the segment of polarimetric curve bounded by phase angles of 30° and 50°. This finding allowed to adduce the evidence in support of the idea voiced by Chernova et al. (1993) about two types of comet with high and low Pmax. Moreover, we have found direct correlation between the maximum polarization degree of comets and their dust-to-gas ratio. The latter is actually a visual proof of assumptions voiced many years ago about a mutual effect of gas and dust on observed polarization of comets (see, for instance, a historical review in Kiselev et al., 2015). Thus, the polarimetric effect of resonant fluorescence should be completely eliminated from the phase-dependent polarization curve of comet in order to correctly interpret the physical

  18. North Polar Erg (United States)


    [figure removed for brevity, see original site] Our topic for the weeks of April 4 and April 11 is dunes on Mars. We will look at the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs,' an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent, and 2) the individual dunes are large in size and complex in form. This VIS image was taken at 81 degrees North latitude during Northern spring. This region of the north polar erg is dominated by a different form of dunes than yesterday's image. Image information: VIS instrument. Latitude 81.4, Longitude 121.9 East (238.1 West). 19 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 at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  19. The Aqueduct Global Flood Analyzer (United States)

    Iceland, Charles


    As population growth and economic growth take place, and as climate change accelerates, many regions across the globe are finding themselves increasingly vulnerable to flooding. A recent OECD study of the exposure of the world's large port cities to coastal flooding found that 40 million people were exposed to a 1 in 100 year coastal flood event in 2005, and the total value of exposed assets was about US 3,000 billion, or 5% of global GDP. By the 2070s, those numbers were estimated to increase to 150 million people and US 35,000 billion, or roughly 9% of projected global GDP. Impoverished people in developing countries are particularly at risk because they often live in flood-prone areas and lack the resources to respond. WRI and its Dutch partners - Deltares, IVM-VU University Amsterdam, Utrecht University, and PBL Netherlands Environmental Assessment Agency - are in the initial stages of developing a robust set of river flood and coastal storm surge risk measures that show the extent of flooding under a variety of scenarios (both current and future), together with the projected human and economic impacts of these flood scenarios. These flood risk data and information will be accessible via an online, easy-to-use Aqueduct Global Flood Analyzer. We will also investigate the viability, benefits, and costs of a wide array of flood risk reduction measures that could be implemented in a variety of geographic and socio-economic settings. Together, the activities we propose have the potential for saving hundreds of thousands of lives and strengthening the resiliency and security of many millions more, especially those who are most vulnerable. Mr. Iceland will present Version 1.0 of the Aqueduct Global Flood Analyzer and provide a preview of additional elements of the Analyzer to be released in the coming years.

  20. Fuel analyzer; Analisador de combustiveis

    Energy Technology Data Exchange (ETDEWEB)

    Cozzolino, Roberval [RS Motors, Indaiatuba, SP (Brazil)


    The current technology 'COMBUSTIMETRO' aims to examine the fuel through performance of the engine, as the role of the fuel is to produce energy for the combustion engine in the form of which is directly proportional to the quality and type of fuel. The 'COMBUSTIMETRO' has an engine that always keeps the same entry of air, fuel and fixed point of ignition. His operation is monitored by sensors (Sonda Lambda, RPM and Gases Analyzer) connected to a processor that performs calculations and records the information, generate reports and graphs. (author)

  1. VOSA: A VO SED Analyzer (United States)

    Rodrigo, C.; Bayo, A.; Solano, E.


    VOSA (VO Sed Analyzer, is a public web-tool developed by the Spanish Virtual Observatory ( and designed to help users to (1) build Spectral Energy Distributions (SEDs) combining private photometric measurements with data available in VO services, (2) obtain relevant properties of these objects (distance, extinction, etc) from VO catalogs, (3) analyze them comparing observed photometry with synthetic photometry from different collections of theoretical models or observational templates, using different techniques (chi-square minimization, Bayesian analysis) to estimate physical parameters of the observed objects (teff, logg, metallicity, stellar radius/distance ratio, infrared excess, etc), and use these results to (4) estimate masses and ages via interpolation of collections of isochrones and evolutionary tracks from the VO. In particular, VOSA offers the advantage of deriving physical parameters using all the available photometric information instead of a restricted subset of colors. The results can be downloaded in different formats or sent to other VO tools using SAMP. We have upgraded VOSA to provide access to Gaia photometry and give a homogeneous estimation of the physical parameters of thousands of objects at a time. This upgrade has required the implementation of a new computation paradigm, including a distributed environment, the capability of submitting and processing jobs in an asynchronous way, the use of parallelized computing to speed up processes (˜ ten times faster) and a new design of the web interface.

  2. Modulus design multiwavelength polarization microscope for transmission Mueller matrix imaging. (United States)

    Zhou, Jialing; He, Honghui; Chen, Zhenhua; Wang, Ye; Ma, Hui


    We have developed a polarization microscope based on a commercial transmission microscope. We replace the halogen light source by a collimated LED light source module of six different colors. We use achromatic polarized optical elements that can cover the six different wavelength ranges in the polarization state generator (PSG) and polarization state analyzer (PSA) modules. The dual-rotating wave plate method is used to measure the Mueller matrix of samples, which requires the simultaneous rotation of the two quarter-wave plates in both PSG and PSA at certain angular steps. A scientific CCD detector is used as the image receiving module. A LabView-based software is developed to control the rotation angels of the wave plates and the exposure time of the detector to allow the system to run fully automatically in preprogrammed schedules. Standard samples, such as air, polarizers, and quarter-wave plates, are used to calibrate the intrinsic Mueller matrix of optical components, such as the objectives, using the eigenvalue calibration method. Errors due to the images walk-off in the PSA are studied. Errors in the Mueller matrices are below 0.01 using air and polarizer as standard samples. Data analysis based on Mueller matrix transformation and Mueller matrix polarization decomposition is used to demonstrate the potential application of this microscope in pathological diagnosis. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  3. Circular polarization terahertz imaging of nonmelanoma skin cancers (United States)

    Martin, Jillian P.

    The use of terahertz (THz) radiation for imaging human tissue and delineating tumor margins has become an appealing topic in the biomedical field because THz radiation is non-ionizing and has the demonstrated ability to differentiate between cancerous and normal tissue without the need for exogenous contrast agents. Previously, a reflective continuous-wave (CW) THz imaging system utilizing a linear polarization-sensitive detection technique was demonstrated and used to delineate tumor margins for nonmelanoma skin cancers [1, 2] and determine reflectivity differences between normal and cancerous colon tissue [3 - 5]. This detection technique involves illuminating ex vivo tissue samples with linearly polarized light and collecting the signal remitted by the sample after passing through an analyzing wire grid polarizer oriented with its transmission axis perpendicular to the linear polarization incident on the sample. By collecting the cross-polarization signal, the strong Fresnel surface reflections from the sample holder interfaces are eliminated and predominantly signal from within the tissue volume is obtained. The aim of the proposed research is to enhance this polarization-sensitive detection technique by incorporating circular polarization illumination and detection channels. This technique has been demonstrated at optical wavelengths [6], where the scattering of light within the tissue volume has been extensively studied; however, it has yet to be implemented using THz radiation. In addition, this detection technique has the potential to demonstrate increased contrast between cancerous and normal tissue, and experimental results may shed light on the mechanism behind the observed contrast.

  4. Ultrashort silica liquid crystal photonic crystal fiber polarization rotator. (United States)

    Hameed, Mohamed Farhat O; Obayya, Salah S A


    In this Letter, an ultra-compact polarization rotator (PR) based on silica photonic crystal fiber with liquid crystal core is introduced and analyzed using full-vectorial finite difference approaches. The analyzed parameters of the suggested PR are the conversion length, modal hybridness, power conversion and crosstalk. In addition, the fabrication tolerance analysis of the reported design is investigated in detail. The proposed PR has an ultra-compact device length of 4.085 μm and an almost 100% polarization conversion ratio.

  5. Polarization extinction ratio and polarization dependent intensity noise in long-pulse supercontinuum generation (Conference Presentation) (United States)

    Chin, Catherine; Dybbro Engelsholm, Rasmus; Moselund, Peter Morten; Feuchter, Thomas; Leick, Lasse; Podoleanu, Adrian; Bang, Ole


    We investigate the polarization of supercontinuum generated in nominally non-birefringent silica photonic crystal fibers over the entire spectrum of the source (450-2400 nm). We demonstrate that the degree of polarization varies over the spectrum but that some parts of the spectrum show stable polarization extinction ratios (PER) of over 10 dB. We experimentally demonstrate how the spectrally resolved polarization develops with increasing power and along the length of the nonlinear fiber. The experimental results are compared to numerical simulations of coupled polarization states mimicking the experimental conditions. Subsequently, a single-shot pulse-to-pulse polarization dependent relative intensity noise (PD-RIN) was measured and the noise characteristics were analyzed using long-tailed and rogue wave statistics. To do this, we used a range of 10 nm narrow bandpass filters (BPF) between 550 nm to 2200 nm, and fast photo detectors, to record 800 consecutive pulses. Peaks from these pulses are first extracted, then distribution of their pulse height histogram (PHH) is constructed. Analysis using higher-order moments about the mean (variance, skewness and kurtosis) showed that: (1) around the pump wavelength of 1064nm, the PD-RIN is lowest, PHH exhibits a Gaussian distribution, and higher order moments are zero, (2) further away from pump, PD-RIN increases in parabolic fashion, PHH follows a left-skewed long-tailed Gamma distribution, and higher-order moments increase. Spectrally, the difference of the PD-RIN in the two orthogonal axes increases with PER.

  6. Polarization Imaging and Insect Vision (United States)

    Green, Adam S.; Ohmann, Paul R.; Leininger, Nick E.; Kavanaugh, James A.


    For several years we have included discussions about insect vision in the optics units of our introductory physics courses. This topic is a natural extension of demonstrations involving Brewster's reflection and Rayleigh scattering of polarized light because many insects heavily rely on optical polarization for navigation and communication.…

  7. Geomorphology of Triton's polar materials (United States)

    Croft, Steven K.


    One of Triton's most debated puzzles is the nature, distribution, and transport of its atmospheric volatiles. The full potential of constraints provided by detailed observations of the morphology and distribution of the polar deposits has not been realized. The objective of this study is characterization of the morphology, distribution, stratigraphy, and geologic setting of Triton's polar materials.

  8. Climate Drives Polar Bear Origins (United States)

    In their provocative analysis of northern bears (“Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage,” Reports, 20 April, p. 344), F. Hailer et al. use independent nuclear loci to show that polar bears originated during the middle Pleistocene, rather than during t...

  9. TREC Dynamic Domain: Polar Science (United States)


    Apache Tika, an open source framework for text and metadata extraction, to provide more searchable content within Polar data repositories. Second, we...Mattmann’s crawl of ADE, performed at the Open Science Codefest and at the NSF DataViz Hackathon for Polar CyberInfrastructure 2. Dr. Mattmann’s...

  10. Carbon nanotube fiber terahertz polarizer (United States)

    Zubair, Ahmed; Tsentalovich, Dmitri E.; Young, Colin C.; Heimbeck, Martin S.; Everitt, Henry O.; Pasquali, Matteo; Kono, Junichiro


    Conventional, commercially available terahertz (THz) polarizers are made of uniformly and precisely spaced metallic wires. They are fragile and expensive, with performance characteristics highly reliant on wire diameters and spacings. Here, we report a simple and highly error-tolerant method for fabricating a freestanding THz polarizer with nearly ideal performance, reliant on the intrinsically one-dimensional character of conduction electrons in well-aligned carbon nanotubes (CNTs). The polarizer was constructed on a mechanical frame over which we manually wound acid-doped CNT fibers with ultrahigh electrical conductivity. We demonstrated that the polarizer has an extinction ratio of ˜-30 dB with a low insertion loss (fiber polarizer and found comparable attenuation to a commercial metallic wire-grid polarizer. Furthermore, based on the classical theory of light transmission through an array of metallic wires, we demonstrated the most striking difference between the CNT-fiber and metallic wire-grid polarizers: the latter fails to work in the zero-spacing limit, where it acts as a simple mirror, while the former continues to work as an excellent polarizer even in that limit due to the one-dimensional conductivity of individual CNTs.

  11. Polarized Scintillating Targets at Psi (United States)

    van den Brandt, B.; Bunyatova, E. I.; Hautle, P.; Konter, J. A.; Mango, S.


    Scintillating polarized targets are now routinely available: blocks of 18×18×5 mm scintillating organic polymer, doped with TEMPO, polarized dynamically in a field of 2.5 T in a vertical 3He-4He dilution refrigerator. A 19 mm diameter plastic lightguide transports the scintillation light from the sample in the mixing chamber to a photomultiplier outside the cryostat.

  12. Carbon nanotube fiber terahertz polarizer

    Energy Technology Data Exchange (ETDEWEB)

    Zubair, Ahmed [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Tsentalovich, Dmitri E.; Young, Colin C. [Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005 (United States); Heimbeck, Martin S. [Charles M. Bowden Laboratory, Aviation & Missile Research, Development, and Engineering Center (AMRDEC), Redstone Arsenal, Alabama 35898 (United States); Everitt, Henry O. [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Charles M. Bowden Laboratory, Aviation & Missile Research, Development, and Engineering Center (AMRDEC), Redstone Arsenal, Alabama 35898 (United States); Pasquali, Matteo [Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005 (United States); Department of Chemistry, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Kono, Junichiro, E-mail: [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States)


    Conventional, commercially available terahertz (THz) polarizers are made of uniformly and precisely spaced metallic wires. They are fragile and expensive, with performance characteristics highly reliant on wire diameters and spacings. Here, we report a simple and highly error-tolerant method for fabricating a freestanding THz polarizer with nearly ideal performance, reliant on the intrinsically one-dimensional character of conduction electrons in well-aligned carbon nanotubes (CNTs). The polarizer was constructed on a mechanical frame over which we manually wound acid-doped CNT fibers with ultrahigh electrical conductivity. We demonstrated that the polarizer has an extinction ratio of ∼−30 dB with a low insertion loss (<0.5 dB) throughout a frequency range of 0.2–1.1 THz. In addition, we used a THz ellipsometer to measure the Müller matrix of the CNT-fiber polarizer and found comparable attenuation to a commercial metallic wire-grid polarizer. Furthermore, based on the classical theory of light transmission through an array of metallic wires, we demonstrated the most striking difference between the CNT-fiber and metallic wire-grid polarizers: the latter fails to work in the zero-spacing limit, where it acts as a simple mirror, while the former continues to work as an excellent polarizer even in that limit due to the one-dimensional conductivity of individual CNTs.

  13. Polarization Characteristics of Pulsar Profiles (United States)

    Han, J. L.; Manchester, R. N.; Qiao, G. J.

    Polarization profiles of several hundred pulsars have been published recently (eg. Gould & Lyne 1998, GL98; Weisberg et al. 1999). In this report, we summarize the characteristics of circular and high linear polarizations of pulsar profiles, based on all previously published data.

  14. Análisis técnico-táctico en Taekwondo con coordenadas polares a través del software HOISAN/Technical-tactical analysis in Taekwondo with polar coordinates through software HOISAN/Análise técnico-tático no Taekwondo com coordenadas polares através de software HOISAN

    National Research Council Canada - National Science Library

    José Antonio López-López; Cristina Menescardi; Isaac Estevan; Coral Falcó; Antonio Hernández-Mendo


    ... in the Olympic Games in London 2012 were analyzed. Based on a taxonomic and methodologically validated system, analysis of polar coordinates was performed using the genuine analytical technique...

  15. Polarization transfer from remote protons in 13C CP/MAS (United States)

    Tripon, Carmen; Aluas, Mihaela; Filip, Xenia; Filip, Claudiu


    An experimental procedure for CP/MAS polarization transfer from remote 1H nuclear spins is introduced, which is applicable to protonated carbons in organic solids. It is based on preparing a state of non-uniform polarization, where directly bonded 13C- 1H nuclei are de-polarized prior to recording the CP buildup curve. This curve is then expected to quantify the polarization transfer from remote protons only. The ability of the cross-polarization/polarization-inversion (CPPI) sequence to generate an initial state suitable for remote 1H CP/MAS scheme is analyzed both theoretically and experimentally. Confining to aliphatic groups, it was found that complete de-polarization of bonded proton is possible in the case of CH, whereas for CH 2 and CH 3 moieties only a partial de-polarization can be achieved. The theoretical predictions have been verified in practice for the particular case of L-alanine. The significance of the results from fundamental, as well as practical point of view, is also discussed. In particular, it is shown that: (i) the coherent description of polarization transfer under CP/MAS, including 1H polarization redistribution, is valid over time-scales longer than commonly assumed in many treatments of cross-polarization, and (ii) the remote protons polarization transfer curve can be used in combination with the conventional CP/MAS curve to get additional structural and dynamical information in organic systems.

  16. Polarity in Mammalian Epithelial Morphogenesis (United States)

    Roignot, Julie; Peng, Xiao; Mostov, Keith


    Cell polarity is fundamental for the architecture and function of epithelial tissues. Epithelial polarization requires the intervention of several fundamental cell processes, whose integration in space and time is only starting to be elucidated. To understand what governs the building of epithelial tissues during development, it is essential to consider the polarization process in the context of the whole tissue. To this end, the development of three-dimensional organotypic cell culture models has brought new insights into the mechanisms underlying the establishment and maintenance of higher-order epithelial tissue architecture, and in the dynamic remodeling of cell polarity that often occurs during development of epithelial organs. Here we discuss some important aspects of mammalian epithelial morphogenesis, from the establishment of cell polarity to epithelial tissue generation. PMID:23378592

  17. Control of the regiospecificity of Candida antarctica lipase by polarity. (United States)

    Watanabe, Yomi; Nagao, Toshihiro; Shimada, Yuji


    Candida antarctica lipase has generally been known to be nonregiospecific. This report, however, showed that its regiospecificity was linearly correlated to the index of polarity of the reaction mixture, which was calculated based on the dielectric constant of the components. Thus, it was strongly indicated that the regiospecificity depended on the polarity of the environment; the higher the polarity, the stricter the regiospecificity. The highest 1(3)-regiospecificity was obtained in the transesterification of oil with ethanol among other alcohols investigated. Although methanol, which is more polar than ethanol, was expected to give highest regiospecificity, it was fatal to the lipase. The transesterification of oil with ethanol (1:10, wt/wt) at 30 degrees C for three hours efficiently accumulated 2-monoacylglycerols without significant fatty acid (FA) specificity. Thus, it was successfully applied to regiospecifically analyze FA composition of triacylglycerols containing saturated and unsaturated FAs of C4-C24.

  18. Single Spin Asymmetries at COMPASS with transverse target polarization

    CERN Document Server

    Schill, C


    COMPASS is a fixed target experiment at CERN investigating the spin structure of the nucleon and performing hadron spectroscopy. The transverse spin structure of the nucleon is studied in semi-inclusive deep-inelastic scattering of 160 GeV/c muons off a transversely polarized proton or deuteron target. In 2002-2005, a transversely polarized 6LiD, and in 2007 a transversely polarized NH3 target were used. To get access to the transversity distribution, different single-spin asymmetries have been measured: The Collins asymmetry, the hadron-pair asymmetry and the transverse lambda polarization have been analyzed. In addition, transverse momentum effects of quarks have been studied by the Sivers effect. New results for the Collins and the Sivers asymmetry on the proton for identified pions and kaons will be presented.

  19. Design of Compact Dual-Polarized Antennas for MIMO Handsets

    Directory of Open Access Journals (Sweden)

    Wenhua Chen


    Full Text Available A design method of compact dual-polarized antennas has been proposed for multiple input and multiple output (MIMO handset application. For the sake of high isolation in dual polarizations, a printed monopole and a hybrid slot antenna are combined using a coplanar waveguide (CPW and microstrip hybrid feeding structure. The proposed topology will result in orthogonal current distribution modes for the different polarizations, which effectively reduces the mutual coupling of the two modes. The operation mechanism of the feeding structure is analyzed in principle and verified by simulation. Simulated and measured results show this compact dual-polarized antenna achieves isolation between the two ports of better than 25 dB, and the relative bandwidth is wider than 23.5%.

  20. Compact Microwave Fourier Spectrum Analyzer (United States)

    Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry


    A compact photonic microwave Fourier spectrum analyzer [a Fourier-transform microwave spectrometer, (FTMWS)] with no moving parts has been proposed for use in remote sensing of weak, natural microwave emissions from the surfaces and atmospheres of planets to enable remote analysis and determination of chemical composition and abundances of critical molecular constituents in space. The instrument is based on a Bessel beam (light modes with non-zero angular momenta) fiber-optic elements. It features low power consumption, low mass, and high resolution, without a need for any cryogenics, beyond what is achievable by the current state-of-the-art in space instruments. The instrument can also be used in a wide-band scatterometer mode in active radar systems.

  1. Lunar true polar wander inferred from polar hydrogen. (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


    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

  2. Optimizing the polarization matrix for ex situ dynamic nuclear polarization. (United States)

    Ludwig, Christian; Marin-Montesinos, Ildefonso; Saunders, Martin G; Günther, Ulrich L


    Although recent advances in dynamic nuclear polarization techniques have boosted the otherwise low sensitivity of NMR spectroscopy, the efficiency of the hyperpolarization process depends on the composition of the polarization matrix, in particular on the contact between the radical and the target molecule and the capability of the matrix to transfer polarization through spin diffusion. A concept for optimal matrix design is presented, applied to obtain two-dimensional heterocorrelated spectra of small drug-like molecules in 1-2 min after 90 min of hyperpolarization.

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

    KAUST Repository

    Ng, Tien Khee


    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.

  4. How could quark polarization be measured

    CERN Document Server

    Efremov, A V


    The perspectives of two new nonstandard methods of transversal quark polarization measurement are considered: the jet handedness and the so-called "Collins effect" due to a spin dependent T-odd fragmentation function responsible for the left-right asymmetry in fragmenting of transversally polarized quarks. Recent experimental indications in favor of these effects are observed: 1. The correlation of the T-odd one-particle fragmentation functions found by DELPHI in Z to 2-jet decay. Integrated over the fraction of longitudinal and transversal momenta, this correlation is of 1.6% order, which means order of 13% for the analyzing power. 2. A rather large ( approximately=10%) handedness transversal to the production plane observed in the diffractive production of ( pi /sup -/ pi /sup +/ pi /sup -/) triples from nuclei by the 40 GeV/c pi /sup -/-beam. It shows a clear dynamic origin and resembles the single spin asymmetry behavior. All this makes us hope to use these effects in polarized DIS experiments for transve...

  5. Polarization dynamics in optical ground wire network. (United States)

    Leeson, Jesse; Bao, Xiaoyi; Côté, Alain


    We report the polarization dynamics in an optical ground wire (OPGW) network for a summer period and a fall period for what is believed to be the first time. To better observe the surrounding magnetic fields contribution to modulating the state of polarization (SOP) we installed a Faraday rotating mirror to correct reciprocal birefringence from quasi-static changes. We also monitored the OPGW while no electrical current was present in the towers' electrical conductors. The spectral analysis, the arc length mapped out over a given time interval on a Poincaré sphere, histograms of the arc length, and the SOP autocorrelation function are calculated to analyze the SOP changes. Ambient temperature changes, wind, Sun-induced temperature gradients, and electrical current all have a significant impact on the SOP drift in an OPGW network. Wind-generated cable oscillations and Sun-induced temperature gradients are shown to be the dominant slow SOP modulations, while Aeolian vibrations and electrical current are shown to be the dominant fast SOP modulations. The spectral analysis revealed that the electrical current gives the fastest SOP modulation to be 300 Hz for the sampling frequency of 1 KHz. This has set the upper speed limit for real-time polarization mode dispersion compensation devices.


    Directory of Open Access Journals (Sweden)

    L. D. Tondiy


    Full Text Available The data on polarized light (PS - a new promising treatment, rehabilitation and prevention, which took its deserved place among the known therapeutic physical factors and may even compete with laser radiation of low and LED therapy. It is reflected the significant contribution of domestic scientists in the study of aircraft action on the body, its introduction in the treatment, rehabilitation and prevention of grippe, ARI. These action's mechanisms of the aircraft on the electro-physiological processes in the body that have the leading role in the regulation of its life. The new moment in the study of aircraft on the body is the evidence of its positive impact on the mechanisms of self body - its different units: the disease's banning - a revitalization of the stress-protective, stress-limiting system antioxidial, detoxification and other protection systems, the formation by the body antiviral and antimicrobial specific substances (interferon and lysozyme, activation of the immune system, phagocytosis, protective functions of skin. The protective and mobilizing role of the second link is studied: which is triggered in case of occurrence of disease or preexisting diseases: PL mobilized processes of restitution, reparations, compensation, immunity and microcirculation. The authors studied the possibility of aircraft's using to enhance performance, reduce side effects of physical factors, which are often used in the treatment (electric methods, treatment by sound, fresh and mineral water, etc..

  7. Classical Maxwellian polarization entanglement

    CERN Document Server

    Carroll, John E


    An explanation of polarization entanglement is presented using Maxwells classical electromagnetic theory.Two key features are required to understand these classical origins.The first is that all waves diffract and weakly diffracting waves,with a principal direction of propagation in the laboratory frame, travel along that direction at speeds ever so slightly less than c.This allows nontrivial Lorentz transformations that can act on selected forward F waves or selected waves R traveling in the opposite direction to show that both can arise from a single zero momentum frame where all the waves are transverse to the original principal direction.Such F and R waves then both belong to a single relativistic entity where correlations between the two are unremarkable.The second feature requires the avoidance of using the Coulomb gauge.Waves, tending to plane waves in the limit of zero diffraction,can then be shown to be composed of two coupled sets of E and B fields that demonstrate the classical entanglement of F an...

  8. Update of the Polar SWIFT model for polar stratospheric ozone loss (Polar SWIFT version 2) (United States)

    Wohltmann, Ingo; Lehmann, Ralph; Rex, Markus


    The Polar SWIFT model is a fast scheme for calculating the chemistry of stratospheric ozone depletion in polar winter. It is intended for use in global climate models (GCMs) and Earth system models (ESMs) to enable the simulation of mutual interactions between the ozone layer and climate. To date, climate models often use prescribed ozone fields, since a full stratospheric chemistry scheme is computationally very expensive. Polar SWIFT is based on a set of coupled differential equations, which simulate the polar vortex-averaged mixing ratios of the key species involved in polar ozone depletion on a given vertical level. These species are O3, chemically active chlorine (ClOx), HCl, ClONO2 and HNO3. The only external input parameters that drive the model are the fraction of the polar vortex in sunlight and the fraction of the polar vortex below the temperatures necessary for the formation of polar stratospheric clouds. Here, we present an update of the Polar SWIFT model introducing several improvements over the original model formulation. In particular, the model is now trained on vortex-averaged reaction rates of the ATLAS Chemistry and Transport Model, which enables a detailed look at individual processes and an independent validation of the different parameterizations contained in the differential equations. The training of the original Polar SWIFT model was based on fitting complete model runs to satellite observations and did not allow for this. A revised formulation of the system of differential equations is developed, which closely fits vortex-averaged reaction rates from ATLAS that represent the main chemical processes influencing ozone. In addition, a parameterization for the HNO3 change by denitrification is included. The rates of change of the concentrations of the chemical species of the Polar SWIFT model are purely chemical rates of change in the new version, whereas in the original Polar SWIFT model, they included a transport effect caused by the

  9. Effective polar cap area and multi-station basis for Polar Cap (PC) indices (United States)

    Stauning, Peter


    The Polar Cap (PC) indices are useful indices for Space Weather forecasts and analyses. The PC indices have been used to monitor the interplanetary geoeffective electric field and solar wind pressure pulses, to analyze cross polar cap voltages, polar cap diameter, and general polar cap dynamics. Furthermore, the PC indices have been used to monitor auroral electrojet intensities, ionospheric Joule heating, and global auroral power, and to predict ring current intensities. For specific Space Weather warning forecasts the PC indices can be used to predict substorm development and the associated risk of power line disturbances in the subauroral regions. The PC indices, PCN (North) and PCS (South), are derived from geomagnetic observations at Thule in Greenland and Vostok in Antarctica, respectively. In order to provide reliable forecast services based on PC indices, it would be advantageous to have available back-up suppliers of index values. The presentation provides an analysis of the effective area for useful PC index derivation and suggests observatories that could provide back-up data for PC index calculations should the primary sources fail due to instrument or communication problems.

  10. Analyzing Agricultural Agglomeration in China

    Directory of Open Access Journals (Sweden)

    Erling Li


    Full Text Available There has been little scholarly research on Chinese agriculture’s geographic pattern of agglomeration and its evolutionary mechanisms, which are essential to sustainable development in China. By calculating the barycenter coordinates, the Gini coefficient, spatial autocorrelation and specialization indices for 11 crops during 1981–2012, we analyze the evolutionary pattern and mechanisms of agricultural agglomeration. We argue that the degree of spatial concentration of Chinese planting has been gradually increasing and that regional specialization and diversification have progressively been strengthened. Furthermore, Chinese crop production is moving from the eastern provinces to the central and western provinces. This is in contrast to Chinese manufacturing growth which has continued to be concentrated in the coastal and southeastern regions. In Northeast China, the Sanjiang and Songnen plains have become agricultural clustering regions, and the earlier domination of aquaculture and rice production in Southeast China has gradually decreased. In summary, this paper provides a political economy framework for understanding the regionalization of Chinese agriculture, focusing on the interaction among the objectives, decisionmaking behavior, path dependencies and spatial effects.

  11. Nuclear physics with polarized particles

    CERN Document Server

    Paetz gen Schieck, Hans


    The measurement of spin-polarization observables in reactions of nuclei and particles is of great utility and advantage when the effects of single-spin sub-states are to be investigated. Indeed, the unpolarized differential cross-section encompasses the averaging over the spin states of the particles, and thus loses details of the interaction process. This introductory text combines, in a single volume, course-based lecture notes on spin physics and on polarized-ion sources with the aim of providing a concise yet self-contained starting point for newcomers to the field, as well as for lecturers in search of suitable material for their courses and seminars. A significant part of the book is devoted to introducing the formal theory-a description of polarization and of nuclear reactions with polarized particles. The remainder of the text describes the physical basis of methods and devices necessary to perform experiments with polarized particles and to measure polarization and polarization effects in nuclear rea...

  12. Chemical characterization by GC-MS and phytotoxic potential of non-polar and polar fractions of seeds of Dioteryx odorata (Aubl. Willd. from Venezuelan regions

    Directory of Open Access Journals (Sweden)

    Alberto de J. Oliveros-Bastidas


    Full Text Available Dipteryx odorata (Aubl. Willd. is a tall arboreal species native to Central and Northern South America. This paper describes the chemical characterization and phytotoxic potential of polar and non-polar extracts from D. odorata seeds. Structural determinations were accomplished by chemical derivatization and analyzed by GC/MS. The chemical composition of the non-polar fraction (hexane and dichloromethane presented fatty acids as major constituent. Medium polar and polar fractions (ethyl acetate and ethanol: water contained carboxylic acid and high 6,7-Dyhidroxycoumarin-β-D-glucopyranoside content, not previously reported for seeds of D. odorata. Extracts showed a significant level of phytotoxic activity, correlated to the content of coumarin derivatives, predominantly in the polar fraction.

  13. Radiative transfer with POLARIS: I. Analysis of magnetic fields through synthetic dust continuum polarization measurements


    Reissl, Stefan; Wolf, Sebastian; Brauer, Robert


    Aims: We present POLARIS (POLArized RadIation Simulator), a newly developed three-dimensional Monte-Carlo radiative transfer code. POLARIS was designed to calculate dust temperature, polarization maps, and spectral energy distributions. It is optimized to handle data that results from sophisticated magneto-hydrodynamic simulations. The main purpose of the code is to prepare and analyze multi-wavelength continuum polarization measurements in the context of magnetic field studies in the interst...

  14. On the use of polar coordinate system in the projective graphic drawings


    Ivashchenko Andrey Viktorovich; Kondrat’eva Tat’yana Mikhaylovna


    Projective graphics is a polyhedra simulation method, which is based on the use of trace diagrams of initial polyhedron. Previously developed computer software allows using Cartesian coordinates. In some cases it is advisable to use polar coordinate system for description of projective graphics drawings. Using the example of icosahedron the authors analyzed the advantages of using projective graphics drawings in the polar coordinate system. The transition to the polar coordinate system is a t...

  15. Positronium formation reaction of polarized positrons and polarized electrons

    Energy Technology Data Exchange (ETDEWEB)

    Hirade, T. [Dept. of Materials Science, Japan Atomic Energy Research Inst., Ibaraki (Japan); Kumada, T. [Advanced Science Research Centre, Japan Atomic Energy Research Inst., Ibaraki (Japan)


    Positrons injected in molecular solids or polymers will have positronium formation around the terminal spur of the positron track, the so-called positron spur, with active species in the spur, such as excess electrons. In the usual case, the electrons are not polarized. At low enough temperatures, long-lived weakly localized electrons are accumulated by irradiation in darkness, and positrons will have a chance to form positronium with these long-lived weakly localized electrons. For these electrons, it is possible to cause them to be polarized by applying a magnetic field at very low temperatures. We have successfully observed the effect on the positronium formation reaction of polarized positrons and polarized electrons. (orig.)

  16. A combinatorial characterisation of embedded polar spaces


    De Beule, Jan; De Boeck, Maarten


    Some classical polar spaces admit polar spaces of the same rank as embedded polar spaces (often arisen as the intersection of the polar space with a non-tangent hyperplane). In this article we look at sets of generators that behave combinatorially as the set of generators of such an embedded polar space, and we prove that they are the set of generators of an embedded polar space.

  17. Upsilon polarization measurement at CDF

    CERN Document Server

    Kuhr, Thomas


    Measurements of production cross sections and polarizations are essential inputs for a theoretical understanding of heavy vector meson production. In this article the CDF measurement of the Y(1S) polarization in the kinematic range |y|<0.6 and 2 < pT [GeV/c] < 40 using a data sample of 2.9/fb is described. Compared to the CDF Run I measurement, with which it agrees, it extends the covered pT range, allowing for a better comparison to predictions in the perturbative regime. The observed trend towards longitudinal polarization at high transverse momentum disagrees with predictions based on non-relativistic QCD.

  18. Industrial solvents analyzed on SolGel-WAX(TM)

    National Research Council Canada - National Science Library

    Angus Hibberd; Gerard Sharp; Dan DiFeo


    ... phase-bonding process in which the polyethylene glycol phase is encapsulated into a sol-gel matrix. The SolGel-WAX column, by the nature of the sol-gel bonding, is an extremely inert, low-bleed, high-temperature column. This inertness gives excellent peak shape of difficult-to-- analyze polar solvents. The high thermal stability gives a low-bleed column and therefore higher signal-to-noise ratio allowing lower detection limits, which is essential in many industrial processes. Also note the excellent separa...

  19. Coherent receiving efficiency in satellite-ground coherent laser communication system based on analysis of polarization (United States)

    Hao, Shiqi; Zhang, Dai; Zhao, Qingsong; Wang, Lei; Zhao, Qi


    Aimed at analyzing the coherent receiving efficiency of a satellite-ground coherent laser communication system, polarization state of the received light is analyzed. We choose the circularly polarized, partially coherent laser as transmitted light source. The analysis process includes 3 parts. Firstly, an theoretical model to analyze received light's polarization state is constructed based on Gaussian-Schell model (GSM) and cross spectral density function matrix. Then, analytic formulas to calculate coherent receiving efficiency are derived in which both initial ellipticity modification and deflection angle between polarization axes of the received light and the intrinsic light are considered. At last, numerical simulations are operated based on our study. The research findings investigate variations of polarization state and obtain analytic formulas to calculate the coherent receiving efficiency. Our study has theoretical guiding significances in construction and optimization of satellite-ground coherent laser communication system.

  20. Mars Polar Lander: The Search Continues (United States)


    [figure removed for brevity, see original site] (A) Polar Lander landing site ellipses. [figure removed for brevity, see original site] (B) MOC coverage (orange) to 17 Jan. 2000. [figure removed for brevity, see original site] (C) MOC image mosaic to 17 Jan. 2000. [figure removed for brevity, see original site] (D) Sample high resolution views from MOC mosaic. Since mid-December 1999, the Mars Orbiter Camera (MOC) onboard the Mars Global Surveyor (MGS) spacecraft has been taking pictures of Mars Polar Lander's landing zone near 76oS, 195oW, in hopes of finding some evidence as to the fate of the spacecraft that went missing during its December 3, 1999, landing attempt. To take these pictures, the MGS spacecraft is pointed a few degrees off its normal, nadir-looking (straight down) path. The first phase of imaging was completed December 24, 1999, but nothing was found. A second, expanded search was requested by the Mars Surveyor Operations Project and was begun in early January 2000.The MOC operations team at Malin Space Science Systems has been busy with the Mars Polar Lander search since December 3rd--initial efforts focused on the use of MOC as a buffer or 'storage space' for data relayed through the MGS Mars Relay (MR) system. It had been hoped that the Polar Lander would try to communicate to Earth using its UHF antenna to relay data through the MGS relay system. Data from the relay come through the MOC and are received at Malin Space Science Systems much in the same way that pictures from MOC are obtained. The relay effort was concluded on January 17, 2000, with no word from the Polar Lander. Meanwhile, the MOC operations team began to plan, command, retrieve, and analyze images designed to look for the Polar Lander. These pictures are taken at the highest spatial resolution possible for MOC, 1.5 meters (5 ft.) per pixel. At this resolution, the fuselage and wings of a jumbo jet can be distinguished, but a Polar Lander would only be a few pixels, at most, in

  1. Topologically Protected Complete Polarization Conversion (United States)

    Guo, Yu; Xiao, Meng; Fan, Shanhui


    We consider the process of conversion between linear polarizations as light is reflected from a photonic crystal slab. We observe that, over a wide range of frequencies, complete polarization conversion can be found at isolated wave vectors. Moreover, such an effect is topological: the complex reflection coefficients have a nonzero winding number in the wave vector space. We also show that bound states in continuum in this system have their wave vectors lying on the critical coupling curve that defines the condition for complete polarization conversion. Our work points to the use of topological photonics concepts for the control of polarization, and suggests the exploration of topological properties of scattering matrices as a route towards creating robust optical devices.

  2. The sensitivity of income polarization

    DEFF Research Database (Denmark)

    Hussain, Azhar


    This study looks at polarization and its components' sensitivity to assumptions about equivalence scales, income definition, ethical income distribution parameters, and the income accounting period. A representative sample of Danish individual incomes from 1984 to 2002 is utilised. Results show...... that polarization has increased over time, regardless of the applied measure, when the last part of the period is compared to the first part of the period; primary causes being increased inequality (alienation) and faster income growth among high incomes relative to those in the middle of the distribution....... Increasing the accounting period confirms the reduction in inequality found for shorter periods, but polarization is virtually unchanged, because income group identification increases. Applying different equivalence scales does not change polarization ranking for different years, but identification ranks...

  3. Polar source analysis : technical memorandum (United States)


    The following technical memorandum describes the development, testing and analysis of various polar source data sets. The memorandum also includes recommendation for potential inclusion in future releases of AEDT. This memorandum is the final deliver...

  4. Anodic Concentration Polarization in SOFCs

    Energy Technology Data Exchange (ETDEWEB)

    Williford, Rick E.; Chick, Lawrence A.; Maupin, Gary D.; Simner, Steve P.; Stevenson, Jeffry W.; Khaleel, Mohammad A.; Wachsman, ED, et al


    Concentration polarization is important because it determines the maximum power output of a solid oxide fuel cell (SOFC) at high fuel utilization. Anodic concentration polarization occurs when the demand for reactants exceeds the capacity of the porous ceramic anode to supply them by gas diffusion mechanisms. High tortuosities (bulk diffusion resistances) are often assumed to explain this behavior. However, recent experiments show that anodic concentration polarization originates in the immediate vicinity of the reactive triple phase boundary (TPB) sites near the anode/electrolyte interface. A model is proposed to describe how concentration polarization is controlled by two localized phenomena: competitive adsorption of reactants in areas adjacent to the reactive TPB sites, followed by relatively slow surface diffusion to the reactive sites. Results suggest that future SOFC design improvements should focus on optimization of the reactive area, adsorption, and surface diffusion at the anode/electrolyte interface.

  5. The definition of cross polarization

    DEFF Research Database (Denmark)

    Ludwig, Arthur


    There are at least three different definitions of cross polarization used in the literature. The alternative definitions are discussed with respect to several applications, and the definition which corresponds to one standard measurement practice is proposed as the best choice....

  6. Quantum-polarization state tomography


    Bayraktar, Ömer; Swillo, Marcin; Canalias, Carlota; Björk, Gunnar


    We propose and demonstrate a method for quantum-state tomography of qudits encoded in the quantum polarization of $N$-photon states. This is achieved by distributing $N$ photons nondeterministically into three paths and their subsequent projection, which for $N=1$ is equivalent to measuring the Stokes (or Pauli) operators. The statistics of the recorded $N$-fold coincidences determines the unknown $N$-photon polarization state uniquely. The proposed, fixed setup manifestly rules out any syste...

  7. Coherent states with elliptical polarization


    Colavita, E.; Hacyan, S.


    Coherent states of the two dimensional harmonic oscillator are constructed as superpositions of energy and angular momentum eigenstates. It is shown that these states are Gaussian wave-packets moving along a classical trajectory, with a well defined elliptical polarization. They are coherent correlated states with respect to the usual cartesian position and momentum operators. A set of creation and annihilation operators is defined in polar coordinates, and it is shown that these same states ...

  8. Circular polarization of transmitted light by sapphirinidae copepods.

    Directory of Open Access Journals (Sweden)

    Yuval Baar

    Full Text Available Circularly polarized light, rare in the animal kingdom, has thus far been documented in only a handful of animals. Using a rotating circular polarization (CP analyzer we detected CP in linearly polarized light transmitted through epipelagic free living Sapphirina metallina copepods. Both left and right handedness of CP was detected, generated from specific organs of the animal's body, especially on the dorsal cephalosome and prosome. Such CP transmittance may be generated by phase retardance either in the muscle fibers or in the multilayer membrane structure found underneath the cuticle. Although the role, if any, played by circularly polarized light in Sapphirinidae has yet to be clarified, in other animals it was suggested to take part in mate choice, species recognition, and other forms of communication.Planktonic Sapphirinidae copepods were found to circularly polarize the light passing through them. Circular polarization may be created by unique, multilayered features of the membrane structure found under their cuticle or by organized muscle fibers.

  9. Improved Diagnostics Using Polarization Imaging and Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Jianhua Xuan


    Full Text Available In recent years, there has been an increasing interest in studying the propagation of polarized light in biological cells and tissues. This paper presents a novel approach to cell or tissue imaging using a full Stokes imaging system with advanced polarization image analysis algorithms for improved diagnostics. The key component of the Stokes imaging system is the electrically tunable retarder, enabling high-speed operation of the system to acquire four intensity images sequentially. From the acquired intensity images, four Stokes vector images can be computed to obtain complete polarization information. Polarization image analysis algorithms are then developed to analyze Stokes polarization images for cell or tissue classification. Specifically, wavelet transforms are first applied to the Stokes components for initial feature analysis and extraction. Artificial neural networks (ANNs are then used to extract diagnostic features for improved classification and prediction. In this study, phantom experiments have been conducted using a prototyped Stokes polarization imaging device. In particular, several types of phantoms, consisting of polystyrene latex spheres in various diameters, were prepared to simulate different conditions of epidermal layer of skin. The experimental results from phantom studies and a plant cell study show that the classification performance using Stokes images is significantly improved over that using the intensity image only.

  10. A new method for improving polarizing neutron coatings (United States)

    Pleshanov, N. K.; Bulkin, A. P.; Syromyatnikov, V. G.


    Nanolayers with a negative neutron potential at the interfaces of magnetic and nonmagnetic layers in neutron coatings may suppress reflection of neutrons with undesired spin direction by one or even two orders of magnitude [N.K. Pleshanov, Nucl. Instr. and Meth. A 613 (2010) 15]. Thus, nanotechnology opens the possibility to build neutron optical polarizers and analyzers of new generation. New experiments with CoFe/Ti/TiZr/Ti (m=2.5) supermirrors verify the high potential of the method for improving polarizing neutron coatings. Superpolarizing coatings not only will improve the performance and thus widen the range of applications of the polarizing devices but may also be the basis for designing novel neutron instrumentation. The use of transmission polarizers on the basis of a ferromagnetic film and a substrate transparent for neutrons is suggested for precise measurements of beam polarization, flipper efficiencies and contributions of NSF and SF scattering into the portion of neutrons reflected with the undesired spin from the polarizing coating.

  11. Polar lipids in phototrophic bacteria of the Rhodospirillaceae and Chromatiaceae families.


    Imhoff, J F; Kushner, D J; Kushwaha, S C; Kates, M


    The polar lipids of photosynthetic purple bacteria of the genera Chromatium, Thiocapsa, Thiocystis, Ectothiorhodospira, Rhodopseudomonas, Rhodospirillum, and Rhodomicrobium were analyzed. Characteristic compositions of the polar lipids were found for most of the Rhodospirillaceae and Chromatiaceae species. Phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin were the major phospholipids in most species. Phosphatidylcholine was present as a major component in all species of the genu...

  12. Is bone mineral composition disrupted by organochlorines in east Greenland polar bears (Ursus maritimus)?

    DEFF Research Database (Denmark)

    Sonne, Christian; Dietz, Rune; Born, Erik W


    We analyzed bone mineral density (BMD) in skulls of polar bears (Ursus maritimus) (n = 139) from East Greenland sampled during 1892-2002. Our primary goal was to detect possible changes in bone mineral content (osteopenia) due to elevated exposure to organochlorine [polychlorinated biphenyls (PCBs.......04) and SigmaCHL (p polar...... bears may have been caused by organochlorine exposure. Udgivelsesdato: 2004-Dec...

  13. Strategies for the liquid chromatographic-mass spectrometric analysis of non-polar compounds

    NARCIS (Netherlands)

    Hayen, H.; Karst, U.


    Electrospray ionization and atmospheric pressure chemical ionization (APCI) have evolved recently as very useful tools for the liquid chromatographic–mass spectrometric (LC–MS) analysis of polar substances. Non-polar compounds, however, are difficult to analyze with these atmospheric pressure

  14. Population genomics reveal recent speciation and rapid evolutionary adaptation in polar bears

    DEFF Research Database (Denmark)

    Liu, Shiping; Lorenzen, Eline D.; Fumagalli, Matteo


    Polar bears are uniquely adapted to life in the High Arctic and have undergone drastic physiological changes in response to Arctic climates and a hyperlipid diet of primarily marine mammal prey. We analyzed 89 complete genomes of polar bear and brown bear using population genomic modeling and show...

  15. GC-MS Analysis and Antimicrobial Activities of the Non-polar ...

    African Journals Online (AJOL)

    GC-MS Analysis and Antimicrobial Activities of the Non-polar Extracts of Mundulea sericea. O Mazimba, IB Masesane, RRT Majinda, A Muzila. Abstract. The composition of the non-polar extracts of the leaves, stem bark and twigs of Mundulea sericea (Fabaceae) were analyzed using GC-MS. Eight, five and eleven ...

  16. Polarization in free electron lasers

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  17. Polarization in heavy quark decays

    Energy Technology Data Exchange (ETDEWEB)

    Alimujiang, K.


    In this thesis I concentrate on the angular correlations in top quark decays and their order (NLO) QCD corrections. I also discuss the leading.order (LO) angular correlations in unpolarized and polarized hyperon decays. In the first part of the thesis I calculate the angular correlation between the top quark spin and the momentum of decay products in the rest frame decay of a polarized top quark into a charged Higgs boson and a bottom quark in Two-Higgs-Doublet-Models: t({up_arrow}) {yields} b + H{sup +}. I provide closed form formulae for the O({alpha}{sub s}) radiative corrections to the unpolarized and the polar correlation functions for m{sub b}{ne}0 and m{sub b}=0. In the second part I concentrate on the semileptonic rest frame decay of a polarized top quark into a bottom quark and a lepton pair: t({up_arrow}){yields}X{sub b}+l{sup +}+{nu}{sub l}. I present closed form expressions for the O({alpha}{sub s}) radiative corrections to the unpolarized part and the polar and azimuthal correlations for m{sub b}{ne}0 and m{sub b}=0. In the last part I turn to the angular distribution in semileptonic hyperon decays. Using the helicity method I derive complete formulas for the leading order joint angular decay distributions occurring in semileptonic hyperon decays including lepton mass and polarization effects. (orig.)

  18. Upgrades to the Polarized Neutron Reflectometer Asterix at LANSCE

    Energy Technology Data Exchange (ETDEWEB)

    Pynn, Roger


    We have upgraded the polarized neutron reflectometer, Asterix, at the Lujan Neutron Scattering Center at Los Alamos for the benefit of the research communities that study magnetic and complex-fluid films, both of which play important roles in support of the DOE’s energy mission. The upgrades to the instrument include: • A secondary spectrometer that was integrated with a Huber sample goniometer purchased with other funds just prior to the start of our project. The secondary spectrometer provides a flexible length for the scattered flight path, includes a mechanism to select among 3 alternative polarization analyzers as well as a support for new neutron detectors. Also included is an optic rail for reproducible positioning of components for Spin Echo Scattering Angle Measurement (SESAME). The entire secondary spectrometer is now non-magnetic, as required for neutron Larmor labeling. • A broad-band neutron polarizer for the incident neutron beam based on the V geometry. • A wide-angle neutron polarization analyzer • A 2d position-sensitive neutron detector • Electromagnetic coils (Wollaston prisms) for SESAME plus the associated power supplies, cooling, safety systems and integration into the data acquisition system. The upgrades allowed a nearly effortless transition between configurations required to serve the polarized neutron reflectometry community, users of the 11 T cryomagnet and users of SESAME.

  19. The study of the wedge-shaped vibration-driven robot motion in a viscous fluid forced by different oscillation laws of the internal mass (United States)

    Nuriev, A. N.; Zakharova, O. S.; Zaitseva, O. N.; Yunusova, A. I.


    A rectilinear motion of a two-mass system in a viscous incompressible fluid is considered. The system consists of a shell having the form of an equilateral triangular cylinder and a movable internal mass. The motion of the system as a whole is forced by longitudinal oscillations of the internal mass relative to the shell. This mechanical system simulates a vibration-driven robot, i.e. a mobile device capable to move in a resistive medium without external moving parts. Investigation of the system is carried out by a direct numerical simulation. A comparative analysis of the characteristics of the motion and flow regimes around the vibration-driven robot is carried out for different internal mass oscillation laws.

  20. An analysis of heat conduction in polar bear hairs using one-dimensional fractional model

    Directory of Open Access Journals (Sweden)

    Zhu Wei-Hong


    Full Text Available Hairs of a polar bear are of superior properties such as the excellent thermal protection. The polar bears can perennially live in an extremely cold environment and can maintain body temperature at around 37 °C. Why do polar bears can resist such cold environment? Its membrane-pore structure plays an important role. In the previous work, we established a 1-D fractional heat conduction equation to reveal the hidden mechanism for the hairs. In this paper, we further discuss solutions and parameters of the equation established and analyze heat conduction in polar bear hairs.

  1. Nuclear physics with polarized particles

    Energy Technology Data Exchange (ETDEWEB)

    Paetz gen. Schieck, Hans [Koeln Univ. (Germany). Inst. fuer Kernphysik


    The measurement of spin-polarization observables in reactions of nuclei and particles is of great utility and advantage when the effects of single-spin sub-states are to be investigated. Indeed, the unpolarized differential cross-section encompasses the averaging over the spin states of the particles, and thus loses details of the interaction process. This introductory text combines, in a single volume, course-based lecture notes on spin physics and on polarized-ion sources with the aim of providing a concise yet self-contained starting point for newcomers to the field, as well as for lecturers in search of suitable material for their courses and seminars. A significant part of the book is devoted to introducing the formal theory - a description of polarization and of nuclear reactions with polarized particles. The remainder of the text describes the physical basis of methods and devices necessary to perform experiments with polarized particles and to measure polarization and polarization effects in nuclear reactions. The book concludes with a brief review of modern applications in medicine and fusion energy research. For reasons of conciseness and of the pedagogical aims of this volume, examples are mainly taken from low-energy installations such as tandem Van de Graaff laboratories, although the emphasis of present research is shifting to medium- and high-energy nuclear physics. Consequently, this volume is restricted to describing non-relativistic processes and focuses on the energy range from astrophysical energies (a few keV) to tens of MeV. It is further restricted to polarimetry of hadronic particles. (orig.)

  2. The GOES-R Advanced Baseline Imager: polarization sensitivity and potential impacts (United States)

    Pearlman, Aaron J.; Cao, Changyong; Wu, Xiangqian


    In contrast to the National Oceanic and Atmospheric Administration's (NOAA's) current geostationary imagers for operational weather forecasting, the next generation imager, the Advanced Baseline Imager (ABI) aboard the Geostationary Operational Environmental Satellite R-Series (GOES-R), will have six reflective solar bands - five more than currently available. These bands will be used for applications such as aerosol retrievals, which are influenced by polarization effects. These effects are determined by two factors: instrument polarization sensitivity and the polarization states of the observations. The former is measured as part of the pre-launch testing program performed by the instrument vendor. We analyzed the results of the pre-launch polarization sensitivity measurements of the 0.47 μm and 0.64 μm channels and used them in conjunction with simulated scene polarization states to estimate potential on-orbit radiometric impacts. The pre-launch test setups involved illuminating the ABI with an integrating sphere through either one or two polarizers. The measurement with one (rotating) polarizer yields the degree of linear polarization of ABI, and the measurements using two polarizers (one rotating and one fixed) characterized the non-ideal properties of the polarizer. To estimate the radiometric performance impacts from the instrument polarization sensitivity, we simulated polarized scenes using a radiative transfer code and accounted for the instrument polarization sensitivity over its field of regard. The results show the variation in the polarization impacts over the day and by regions of the full disk can reach up to 3.2% for the 0.47μm channel and 4.8% for the 0.64μm channel. Geostationary orbiters like the ABI give the unique opportunity to show these impacts throughout the day compared to low earth orbiters, which are more limited to certain times of day. This work may enhance the ability to diagnose anomalies on-orbit.

  3. Studies on the lipid components of endotoxin. II. Chemical analyses and biological properties of neutral, polar-I and polar-II subfractions. (United States)

    Konno, S


    Lipid components obtained from Salmonella typhosa O-901 endotoxin by acid hydrolysis were separated into neutral, polar-I and polar-II lipid fractions by silica gel column chromatography. These lipids were further separated by silica gel column and/or thin-layer chromatography. The subfractions were analyzed by thin-layer chromatography, gas chromatography and infrared spectrophotometry. Seven subfractions obtained from the neutral lipid fraction contained lauric, myristic, palmitic, 3-OH-myristic acid, artificial products of 3-OH-myristic acid, or a small amount of two unidentified fatty acids. These fatty acids and glucosamine were commonly detected in six subfractions obtained from the polar-I lipid fraction. Fatty acids, glucosamine, and O-phosphorylethanolamine were detected in all of the 13 subfractions obtained from the polar-II lipid fraction. Chick embryo lethal activity, rabbit pyrogenicity and in vitro interferon inducing activity were found in three polar-I lipid subfractions and five polar-II lipid subfractions, but not in neutral lipids. The activities were highest in a polar-II lipid subfraction which contained smaller amounts of O-phosphorylethanolamine and glucosamine than the other subfractions. However, no particular chemical constituent(s) related to the biological activities could be found. Prolonged acid hydrolysis of the polar-II lipids gave rise to neutral and polar-I lipids. Chemical and biological aspects of the lipid constituents of endotoxin are discussed.

  4. The RHIC polarized H⁻ ion source. (United States)

    Zelenski, A; Atoian, G; Raparia, D; Ritter, J; Steski, D


    A novel polarization technique had been successfully implemented for the Relativistic Heavy Ion Collider (RHIC) polarized H(-) ion source upgrade to higher intensity and polarization. In this technique, a proton beam inside the high magnetic field solenoid is produced by ionization of the atomic hydrogen beam (from external source) in the He-gaseous ionizer cell. Further proton polarization is produced in the process of polarized electron capture from the optically pumped Rb vapor. The use of high-brightness primary beam and large cross sections of charge-exchange cross sections resulted in production of high intensity H(-) ion beam of 85% polarization. The source very reliably delivered polarized beam in the RHIC Run-2013 and Run-2015. High beam current, brightness, and polarization resulted in 75% polarization at 23 GeV out of Alternating Gradient Synchrotron (AGS) and 60%-65% beam polarization at 100-250 GeV colliding beams in RHIC.

  5. Dynamic nuclear polarization polarizer for sterile use intent. (United States)

    Ardenkjaer-Larsen, Jan H; Leach, Andrew M; Clarke, Neil; Urbahn, John; Anderson, Denise; Skloss, Timothy W


    A novel polarizer based on the dissolution-dynamic nuclear polarization (DNP) method has been designed, built and tested. The polarizer differs from those previously described by being designed with sterile use intent and being compatible with clinical use. The main features are: (1) an integral, disposable fluid path containing all pharmaceuticals constituting a sterile barrier, (2) a closed-cycle cryogenic system designed to eliminate consumption of liquid cryogens and (3) multi-sample polarization to increase throughput. The fluid path consists of a vial with the agent to be polarized, a pair of concentric inlet and outlet tubes connected to a syringe with dissolution medium and a receiver, respectively. The fluid path can operate at up to 400 K and 2.0 MPa and generates volumes as high as 100 mL. An inline filter removes the amount of electron paramagnetic agent in the final product by more than 100-fold in the case of [1-(13)C]pyruvate. The system uses a sorption pump in conjunction with a conventional cryocooler. The system operates through cycles of pumping to low temperature and regeneration of the sorption pump. The magnet accommodates four samples at the same time. A temperature of less than 1 K was achieved for 68 h (no sample heat loads) with a liquid helium volume of 2.4 L. The regeneration of the liquid helium could be achieved in less than 10 h, and the transition to cold (power. The loading of a sample adds less than 50 J of heat to the helium bath by introducing the sample over 15 min. The heat load imposed on the helium bath during dissolution was less than 70 J. The measured liquid state polarization was 18 ± 2%. Copyright © 2011 John Wiley & Sons, Ltd.

  6. Time-resolved scanning electron microscopy with polarization analysis

    Energy Technology Data Exchange (ETDEWEB)

    Frömter, Robert, E-mail:; Oepen, Hans Peter [Institut für Nanostruktur-und Festkörperphysik, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg (Germany); The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg (Germany); Kloodt, Fabian; Rößler, Stefan; Frauen, Axel; Staeck, Philipp; Cavicchia, Demetrio R. [Institut für Nanostruktur-und Festkörperphysik, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg (Germany); Bocklage, Lars [Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg (Germany); The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg (Germany); Röbisch, Volker; Quandt, Eckhard [Institute for Materials Science, Christian-Albrechts-Universität zu Kiel, 24143 Kiel (Germany)


    We demonstrate the feasibility of investigating periodically driven magnetization dynamics in a scanning electron microscope with polarization analysis based on spin-polarized low-energy electron diffraction. With the present setup, analyzing the time structure of the scattering events, we obtain a temporal resolution of 700 ps, which is demonstrated by means of imaging the field-driven 100 MHz gyration of the vortex in a soft-magnetic FeCoSiB square. Owing to the efficient intrinsic timing scheme, high-quality movies, giving two components of the magnetization simultaneously, can be recorded on the time scale of hours.

  7. The Polarization and Magnetic Moment of the Sigma Plus Hyperon

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, Carol Ann [Univ. of Wisconsin, Madison, WI (United States)


    The polarization and magnetic moment of the $\\Sigma^+$ hyperon have been determined by analyzing 137,300 $\\Sigma^+ \\to p \\pi^0, \\pi^0 \\to 2 \\gamma$ decays. A beam of + inclusively-produced, polarized $\\Sigma^+$ hyperons was generated in a Fermilab Meson Lab beamline by 400 GeV protons incident on a beryllium target. The $\\Sigma^+$'s were produced at an angle of 5 mrad and ranged in momentum from 140 GeV/c to 350 GeV/c. + 0 The $\\Sigma^+ \\to p \\pi^0, \\pi \\to 2 \\gamma$ decays were detected by a multiwire proportional and drift chamber spectrometer with a lead glass array....

  8. On the use of polar coordinate system in the projective graphic drawings

    Directory of Open Access Journals (Sweden)

    Ivashchenko Andrey Viktorovich


    Full Text Available Projective graphics is a polyhedra simulation method, which is based on the use of trace diagrams of initial polyhedron. Previously developed computer software allows using Cartesian coordinates. In some cases it is advisable to use polar coordinate system for description of projective graphics drawings. Using the example of icosahedron the authors analyzed the advantages of using projective graphics drawings in the polar coordinate system. The transition to the polar coordinate system is a tool that allows using certain patterns of projective graphics drawings in the process of calculation. When using polar coordinate system the search of Polar correspondence for the directs is simplified. In order to analyze the two lines in the polar coordinate system it is enough to compare the corresponding coefficients of the equations of these lines. The authors consider a diagram of the icosahedron in polar coordinates, and a corresponding fragment of calculation program in the Mathematica system. Some examples of forming based on icosahedrons are offered. Optimization of computer programs using polar coordinate system will simplifies the calculations of projective graphics drawings, accelerates the process of constructing three-dimensional models, which expand the possibilities of selecting original solutions. Finally, the authors conclude that it is appropriate to use the polar coordinate system only in the construction of projective graphics diagrams of the planes system having rich symmetry. All Platonic and Archimedean solids, Catalan solid possess this property.

  9. Laser beam splitting by polarization encoding. (United States)

    Wan, Chenhao


    A scheme is proposed to design a polarization grating that splits an incident linearly polarized beam to an array of linearly polarized beams of identical intensity distribution and various azimuth angles of linear polarization. The grating is equivalent to a wave plate with space-variant azimuth angle and space-variant phase retardation. The linear polarization states of all split beams make the grating suitable for coherent beam combining architectures based on Dammann gratings.

  10. Mueller imaging polarimetry of holographic polarization gratings inscribed in azopolymer films. (United States)

    Martinez-Ponce, Geminiano


    Three types of polarization gratings have been recorded in azopolymer films by the symmetrical superposition of different orthogonal pairs of polarized beams. The inscribed holographic elements have been analyzed microscopically in a Mueller polarimeter in order to image the optical anisotropies photoinduced in the film. In the most of cases, the spatial modulation of diattenuation, birefringence, and optical rotation reproduced quite well previous results reported in the literature. Nevertheless, in the particular case of coherent superposition of p- and s-polarized beams, the spatial frequency for optical rotation (related to the Stokes parameter V) was different from the one observed in linear anisotropy (related to the Stokes parameter U). It is shown by theory and experiment that, in the polarized field used to record this polarization grating, the fourth-Stokes parameter changes sign, which implies a change in circular polarization handedness, practically once between two adjacent maxima.

  11. The Role of polarized positrons and electrons in revealing fundamental interactions at the linear collider

    Energy Technology Data Exchange (ETDEWEB)

    Moortgat-Pick, G.; /CERN /Durham U., IPPP; Abe, T.; Alexander, G.; Ananthanarayan, B.; Babich, A.A.; Bharadwaj, V.; Barber, D.; Bartl, A.; Brachmann, A.; Chen, S.; Clarke,; Clendenin, J.E.; Dainton, J.; Desch, K.; Diehl, M.; Dobos, B.; Dorland, T.; Eberl, H.; Ellis, John R.; Flottman, K.; Frass, H.; /CERN /Durham U., IPPP /Colorado U. /Tel-Aviv


    The proposed International Linear Collider (ILC) is well-suited for discovering physics beyond the Standard Model and for precisely unraveling the structure of the underlying physics. The physics return can be maximized by the use of polarized beams. This report shows the paramount role of polarized beams and summarizes the benefits obtained from polarizing the positron beam, as well as the electron beam. The physics case for this option is illustrated explicitly by analyzing reference reactions in different physics scenarios. The results show that positron polarization, combined with the clean experimental environment provided by the linear collider, allows to improve strongly the potential of searches for new particles and the identification of their dynamics, which opens the road to resolve shortcomings of the Standard Model. The report also presents an overview of possible designs for polarizing both beams at the ILC, as well as for measuring their polarization.

  12. Revealing Fundamental Interactions: the Role of Polarized Positrons and Electrons at the Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Moortgat-Pick, G.; /CERN /Durham U., IPPP; Abe, T.; Alexander, G.; Ananthanarayan, B.; Babich, A.A.; Bharadwaj, V.; Barber, D.; Bartl, A.; Brachmann, A.; Chen, S.; Clarke,; Clendenin, J.E.; Dainton, J.; Desch, K.; Diehl, M.; Dobos, B.; Dorland, T.; Eberl, H.; Ellis, John R.; Flottman, K.; Frass, H.; /CERN /Durham U., IPPP /Colorado U. /Tel-Aviv


    The proposed International Linear Collider (ILC) is well-suited for discovering physics beyond the Standard Model and for precisely unraveling the structure of the underlying physics. The physics return can be maximized by the use of polarized beams. This report shows the paramount role of polarized beams and summarizes the benefits obtained from polarizing the positron beam, as well as the electron beam. The physics case for this option is illustrated explicitly by analyzing reference reactions in different physics scenarios. The results show that positron polarization, combined with the clean experimental environment provided by the linear collider, allows to improve strongly the potential of searches for new particles and the identification of their dynamics, which opens the road to resolve shortcomings of the Standard Model. The report also presents an overview of possible designs for polarizing both beams at the ILC, as well as for measuring their polarization.

  13. Commissioning experiment of the polarized internal gas target with deuterium at ANKE/COSY

    Energy Technology Data Exchange (ETDEWEB)

    Gou, Boxing [Institut fuer Kernphysik, Forschungszentrum Juelich (Germany); Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China); Collaboration: ANKE-Collaboration


    In order to conduct the production experiments with polarized deuterium target and (un)polarized proton beam at ANKE/COSY, a commissioning experiment of the polarized internal target with deuterium is imperative. The commissioning experiment includes the measurements of both the vector (Q{sub y}) and tensor (Q{sub yy}) polarization of the deuterium gas target through the nuclear reactions with large and well known analyzing powers, which can be detected in ANKE. The dependence of the polarizations along the storage cell is also determined. The poster presents the physics case for the experiments with deuterium polarized internal target and the apparatus needed for the commissioning experiment, as well as the procedure of extraction for spin observables.

  14. The HB-2D Polarized Neutron Development Beamline at the High Flux Isotope Reactor (United States)

    Crow, Lowell; Hamilton, WA; Zhao, JK; Robertson, JL


    The Polarized Neutron Development beamline, recently commissioned at the HB-2D position on the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, provides a tool for development and testing of polarizers, polarized neutron devices, and prototyping of polarized neutron techniques. With available monochromators including pyrolytic graphite and polarizing enriched Fe-57 (Si), the instrument has operated at 4.25 and 2.6 Å wavelengths, using crystal, supermirror, or He-3 polarizers and analyzers in various configurations. The Neutron Optics and Development Team has used the beamline for testing of He-3 polarizers for use at other HFIR and Spallation Neutron Source (SNS) instruments, as well as a variety of flipper devices. Recently, we have acquired new supermirror polarizers which have improved the instrument performance. The team and collaborators also have continuing demonstration experiments of spin-echo focusing techniques, and plans to conduct polarized diffraction measurements. The beamline is also used to support a growing use of polarization techniques at present and future instruments at SNS and HFIR.

  15. Large-mode-area single-polarization single-mode photonic crystal fiber: design and analysis. (United States)

    Kumar, Ajeet; Saini, Than Singh; Naik, Kishor Dinkar; Sinha, Ravindra Kumar


    A rectangular core photonic crystal fiber structure has been presented and analyzed for single-polarization single-mode operation. Single-polarization is obtained with asymmetric design and by introducing different loss for x-polarization and y-polarization of fundamental modes. Single-polarization single-mode operation of the proposed photonic crystal fiber is investigated in detail by using a full vector finite element method with an anisotropic perfectly matched layer. The variations of the confinement loss and effective mode area of x-polarization and y-polarization of fundamental modes have been simulated by varying the structural parameters of the proposed photonic crystal fiber. At the optimized parameters, confinement loss and effective mode area is obtained as 0.94 dB/m and 60.67  μm2 for y-polarization as well as 26.67 dB/m and 67.23  μm2 for x-polarization of fundamental modes, respectively, at 1.55 μm. Therefore simulation results confirmed that, 0.75 m length of fiber will be sufficient to get a y-polarized fundamental mode with an effective mode area as large as 60.67  μm2.

  16. Optical image encoding based on digital holographic recording on polarization state of vector wave. (United States)

    Lin, Chao; Shen, Xueju; Xu, Qinzu


    We propose and analyze a compact optical image encoder based on the principle of digital holographic recording on the polarization state of a vector wave. The optical architecture is a Mach-Zehnder interferometer with in-line digital holographic recording mechanism. The original image is represented by distinct polarization states of elliptically polarized light. This state of polarization distribution is scrambled and then recorded by a two-step digital polarization holography method with random phase distributed reference wave. Introduction of a rotation key in the object arm and phase keys in the reference arm can achieve the randomization of plaintext. Statistical property of cyphertext is analyzed from confusion and diffusion point of view. Fault tolerance and key sensitivity of the proposed approach are also investigated. A chosen plaintext attack on the proposed algorithm exhibits its high security level. Simulation results that support the theoretical analysis are presented.

  17. Polarization-Dependent Multi-Functional Metamaterial as Polarization Filter, Transparent Wall and Circular Polarizer using Ring-Cross Resonator

    Directory of Open Access Journals (Sweden)

    Z. Zhang


    Full Text Available We propose a polarization-dependent multi-functional metamaterial using ring-cross resonator. Based on the analysis of surface current distributions induced by different polarized incidence, we demonstrate that the proposed metamaterial serves as a polarization filter, a transparent wall and a circular polarizer under different polarization normal incidence. Additionally, parameter analyses on the control of resonance are discussed to complementally explain the physical origin. Simulated results show that the proposed metamaterial functions as a polarization filter eliminating the x-polarization wave at 10.1 GHz and y-polarization wave at 14.3 GHz, a transparent wall transmitting both x-polarized and y-polarized incident waves at 12.6 GHz, and a broadband circular polarizer converting the +45° polarized (-45° polarized incident wave to the left (right handed circularly polarized wave from 10.8 to 12.8 GHz, respectively. Measured results agree well with the simulation and validate the performance of the proposed multifunctional metamaterial.

  18. Monte Carlo implementation of polarized hadronization (United States)

    Matevosyan, Hrayr H.; Kotzinian, Aram; Thomas, Anthony W.


    We study the polarized quark hadronization in a Monte Carlo (MC) framework based on the recent extension of the quark-jet framework, where a self-consistent treatment of the quark polarization transfer in a sequential hadronization picture has been presented. Here, we first adopt this approach for MC simulations of the hadronization process with a finite number of produced hadrons, expressing the relevant probabilities in terms of the eight leading twist quark-to-quark transverse-momentum-dependent (TMD) splitting functions (SFs) for elementary q →q'+h transition. We present explicit expressions for the unpolarized and Collins fragmentation functions (FFs) of unpolarized hadrons emitted at rank 2. Further, we demonstrate that all the current spectator-type model calculations of the leading twist quark-to-quark TMD SFs violate the positivity constraints, and we propose a quark model based ansatz for these input functions that circumvents the problem. We validate our MC framework by explicitly proving the absence of unphysical azimuthal modulations of the computed polarized FFs, and by precisely reproducing the earlier derived explicit results for rank-2 pions. Finally, we present the full results for pion unpolarized and Collins FFs, as well as the corresponding analyzing powers from high statistics MC simulations with a large number of produced hadrons for two different model input elementary SFs. The results for both sets of input functions exhibit the same general features of an opposite signed Collins function for favored and unfavored channels at large z and, at the same time, demonstrate the flexibility of the quark-jet framework by producing significantly different dependences of the results at mid to low z for the two model inputs.

  19. Bi-polar Supernova Explosions


    Wang, Lifan; Howell, D. Andrew; Hoeflich, Peter; Wheeler, J. Craig


    We discuss the optical spectropolarimetry of several core-collapse supernovae, SN 1996cb (Type IIB), SN 1997X (Type Ic), and SN 1998S (Type IIn). The data show polarization evolution of several spectral features at levels from 0.5% to above 4%. The observed line polarization is intrinsic to the supernovae and not of interstellar origin. These data suggest that the the distribution of ejected matter is highly aspherical. In the case of SN 1998S, the minimum major to minor axis ratio must be la...

  20. Ferroelectric control of spin polarization. (United States)

    Garcia, V; Bibes, M; Bocher, L; Valencia, S; Kronast, F; Crassous, A; Moya, X; Enouz-Vedrenne, S; Gloter, A; Imhoff, D; Deranlot, C; Mathur, N D; Fusil, S; Bouzehouane, K; Barthélémy, A


    A current drawback of spintronics is the large power that is usually required for magnetic writing, in contrast with nanoelectronics, which relies on "zero-current," gate-controlled operations. Efforts have been made to control the spin-relaxation rate, the Curie temperature, or the magnetic anisotropy with a gate voltage, but these effects are usually small and volatile. We used ferroelectric tunnel junctions with ferromagnetic electrodes to demonstrate local, large, and nonvolatile control of carrier spin polarization by electrically switching ferroelectric polarization. Our results represent a giant type of interfacial magnetoelectric coupling and suggest a low-power approach for spin-based information control.

  1. Graphics of polar figure; Graficado de figura polar

    Energy Technology Data Exchange (ETDEWEB)

    Macias B, L.R


    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)

  2. Early detection of precancer using Polarized Light Scattering Spectroscopy (United States)

    Gurjar, Rajan; Backman, Vadim; Itzkan, Irving; Dasari, Ramachandra; Perelman, Lev; Feld, Michael; Badizadegan, Kamran


    We have developed a light scattering technique to detect early pre-cancerous changes in the tissues which, line the epithelial surfaces of the body. The majority of cancers are epithelial in nature. We use light reflection spectroscopy to observe the earliest sign, the enlargement of the index of the cells which, line this layer. Our method is based on the feature that single scattering in the backward direction retains the polarization of the light incident on nucleus in the epithelial layer whereas multiple scattering destroys the polarization. Collecting the backscattering spectral intensities of both polarizations, and taking their difference, we extract the single scattering component. The signals are analyzed to extract the nuclear density, size and the relative refractive index. The experimental results will be presented to illustrate the physical basis of the technique, and its biological application.

  3. Surface Polarization Effects on Ion-Containing Emulsions (United States)

    Shen, Meng; Li, Honghao; Olvera de la Cruz, Monica


    Surface polarization in ion-containing heterogeneous dielectric media such as cell media and emulsions is determined by and determines the positions of the ions. We compute the surface polarization self-consistently as the ions move and analyze their effects on the interactions between electro-neutral, ion-containing droplets using coarse-grained molecular dynamics simulations based on the true energy functional. For water droplets immersed in oil, the interdroplet interaction is attractive, and the surface polarization makes the major contribution. By contrast, for oil droplets in water, the ion-surface induced charge interaction is repulsive and counteracts the attraction between the ions, leading to a small attractive interaction between the droplets. This research improves our understanding of self-assembly in mixed phases such as metal extraction for recovering rare earth elements and nuclear waste as well as water purification.

  4. Recoil detection with a polarized sup 3 He target

    CERN Document Server

    Higinbotham, D W; Bauer, T; Boersma, D J; Van der Brand, J F J; Bulten, H J; Van Buuren, L D; Ent, R; Ferro-Luzzi, M; Geurts, D; Harvey, M; Heimberg, P; Norum, B E; Passchier, I; Poolman, H R; Six, E; Steenbakkers, M F M; Szczerba, D; Vries, H D


    The ultra-thin gas targets used in storage ring internal target experiments allow low energy, heavy nuclei to emerge from the target region. A detector capable of analyzing these nuclei provides unique access to many nuclear reactions. We report here the first use of such a detector in conjunction with a polarized sup 3 He internal target and a polarized electron beam. The results of using the detector as a luminosity monitor and as a polarimeter to measure the product of beam and target polarizations are presented. The ability to study coherent pion production via the reactions sup 3 H=vector (e-vector, e' sup 3 He)pi sup 0 and sup 3 H-vector(e-vector, e' sup 3 H)pi sup + is shown along with the ability of the detector to unambiguously separate the two- and three-body breakup channels of the reaction sup 3 H-vectore(e-vector, e'p).

  5. Modeling the Time-Dependent Polarization of Blazars

    Directory of Open Access Journals (Sweden)

    Alan P. Marscher


    Full Text Available Linear polarization is an extremely valuable observational tool for probing the dynamic physical conditions of blazar jets. Some patterns are seen in the data, suggestive of order that can be explained by shock waves and helical magnetic field components. However, much disorder is apparent, which implies that turbulence plays a major role as well, especially in the fluctuations of flux and polarization, and perhaps particle acceleration. Here, we present some actual flux and polarization versus time data, plus simulations of model jets. We analyze the output of the simulations in a manner that can be compared with observational data. The results suggest that the ratio of turbulent to ordered magnetic fields varies with time.

  6. Polarizing a stored proton beam by spin-flip?

    Energy Technology Data Exchange (ETDEWEB)

    Oellers, Dieter Gerd Christian


    The present thesis discusses the extraction of the electron-proton spin-flip cross-section. The experimental setup, the data analysis and the results are pictured in detail. The proton is described by a QCD-based parton model. In leading twist three functions are needed. The quark distribution, the helicity distribution and the transversity distribution. While the first two are well-known, the transversity distribution is largely unknown. A self-sufficient measurement of the transversity is possible in double polarized proton-antiproton scattering. This rises the need of a polarized antiproton beam. So far spin filtering is the only tested method to produce a polarized proton beam, which may be capable to hold also for antiprotons. In-situ polarization build-up of a stored beam either by selective removal or by spin-flip of a spin-(1)/(2) beam is mathematically described. A high spin-flip cross-section would create an effective method to produce a polarized antiproton beam by polarized positrons. Prompted by conflicting calculations, a measurement of the spin-flip cross-section in low-energy electron-proton scattering was carried out. This experiment uses the electron beam of the electron cooler at COSY as an electron target. The depolarization of the stored proton beam is detected. An overview of the experiment is followed by detailed descriptions of the cycle setup, of the electron target and the ANKE silicon tracking telescopes acting as a beam polarimeter. Elastic protondeuteron scattering is the analyzing reaction. The event selection is depicted and the beam polarization is calculated. Upper limits of the two electron-proton spin-flip cross-sections {sigma} {sub parallel} and {sigma} {sub perpendicular} {sub to} are deduced using the likelihood method. (orig.)

  7. Polarized proton beams since the ZGS

    Energy Technology Data Exchange (ETDEWEB)

    Krisch, A.D.


    The author discusses research involving polarized proton beams since the ZGS`s demise. He begins by reminding the attendee that in 1973 the ZGS accelerated the world`s first high energy polarized proton beam; all in attendance at this meeting can be proud of this accomplishment. A few ZGS polarized proton beam experiments were done in the early 1970`s; then from about 1976 until 1 October 1979, the majority of the ZGS running time was polarized running. A great deal of fundamental physics was done with the polarized beam when the ZGS ran as a dedicated polarized proton beam from about Fall 1977 until it shut down on 1 October 1979. The newly created polarization enthusiats then dispersed; some spread polarized seeds al over the world by polarizing beams elsewhere; some wound up running the High Energy and SSC programs at DOE.

  8. Towards Measurement of Polarization Properties of Skin using the Ellipsometry Technique

    Directory of Open Access Journals (Sweden)

    Pejhman Ghassemi


    Full Text Available Introduction: The human skin is an active medium from the optical point of view. Therefore, the diagnostic and therapeutic techniques employing light are increasing. Current optical techniques are based on the measurement of the intensity of reflected absorbed or backscattered light from or within skin. Studies have shown that biological tissues, and in particular skin, demonstrate polarization properties. Scattering of light from the surface of skin or the layers within it is a function of incident polarization. Therefore, by changing the polarization of the incident light and measuring the backscattered light, we can study those skin properties which affect the state of polarization. Material and methods: We have implemented a scattering ellipsometry system in order to investigate the polarization properties of a phantom representing skin. Using the Stocks vector defining the state of polarization and measuring the elements of the Mueller matrix representing the phantom under study, we have shown that by changing the reflection and scattering properties of the sample, polarization characteristics of the backscattered light will be affected. Results: The results of this investigation showed that some elements of the Mueller matrix of the phantom under study were affected by the polarization state of the incident light and the scattering component within the phantom. Therefore, these elements have the potential of being used as polarization markers of the biological tissue. Discussion and conclusion: Upon interaction of polarized light with the skin tissue, the backscattered light will contain optical and polarization information about the skin. Using a simple laboratory-made phantom, we have shown that by analyzing the polarization information within the backscattered light we can study the cause, and possibly the disease, which affected the polarization characteristics of the skin.

  9. VIIRS-J1 Polarization Narrative (United States)

    Waluschka, Eugene; McCorkel, Joel; McIntire, Jeff; Moyer, David; McAndrew, Brendan; Brown, Steven W.; Lykke, Keith; Butler, James; Meister, Gerhard; Thome, Kurtis J.


    The VIS/NIR bands polarization sensitivity of Joint Polar Satellite Sensor 1 (JPSS1) Visible/Infrared Imaging Radiometer Suite (VIIRS) instrument was measured using a broadband source. While polarization sensitivity for bands M5-M7, I1, and I2 was less than 2.5%, the maximum polarization sensitivity for bands M1, M2, M3, and M4 was measured to be 6.4%, 4.4%, 3.1%, and 4.3%, respectively with a polarization characterization uncertainty of less than 0.3%. A detailed polarization model indicated that the large polarization sensitivity observed in the M1 to M4 bands was mainly due to the large polarization sensitivity introduced at the leading and trailing edges of the newly manufactured VISNIR bandpass focal plane filters installed in front of the VISNIR detectors. This was confirmed by polarization measurements of bands M1 and M4 bands using monochromatic light. Discussed are the activities leading up to and including the instruments two polarization tests, some discussion of the polarization model and the model results, the role of the focal plane filters, the polarization testing of the Aft-Optics-Assembly, the testing of the polarizers at Goddard and NIST and the use of NIST's T-SIRCUS for polarization testing and associated analyses and results.

  10. Mercury and cortisol in Western Hudson Bay polar bear hair. (United States)

    Bechshoft, T; Derocher, A E; Richardson, E; Mislan, P; Lunn, N J; Sonne, C; Dietz, R; Janz, D M; St Louis, V L


    Non-invasive methods of assessing animal health and life history are becoming increasingly popular in wildlife research; hair samples from polar bears (Ursus maritimus), are being used to study an ever broader range of anthropogenic and endocrine compounds. A number of contaminants are known to disrupt endocrine function in polar bears. However, the relationship between mercury and cortisol remains unknown, although mercury is an endocrine disruptor in other species. Here, we examine the relationship between concentrations of cortisol and total mercury (THg) analyzed in guard hair from 378 polar bears (184 females, 194 males) sampled in Western Hudson Bay, 2004-2012. The difference in mean cortisol concentration between female (0.8 ± 0.6 pg/mg) and male (0.7 ± 0.5 pg/mg) polar bears bordered on significance (p = 0.054). However, mean mercury concentration was significantly greater (p = 0.009) in females (4.7 ± 1.4 μg/g) than males (4.3 ± 1.2 μg/g). Hair cortisol in males was significantly influenced by mercury, age, and fatness, as well as interactions between mercury and year, mercury and fatness, and year and fatness (all: p polar bears.

  11. Stellar Nuclei and Inner Polar Disks in Lenticular Galaxies (United States)

    Sil'chenko, Olga K.


    I analyze statistics of the stellar population properties for stellar nuclei and bulges of nearby lenticular galaxies in different environments by using panoramic spectral data of the integral-field spectrograph SAURON retrieved from the open archive of the Isaac Newton Group. I also estimate the fraction of nearby lenticular galaxies having inner polar gaseous disks by exploring the volume-limited sample of early-type galaxies of the ATLAS-3D survey. By inspecting the two-dimensional velocity fields of the stellar and gaseous components with the running tilted-ring technique, I have found seven new cases of inner polar disks. Together with those, the frequency of inner polar disks in nearby S0 galaxies reaches 10%, which is much higher than the frequency of large-scale polar rings. Interestingly, the properties of the nuclear stellar populations in the inner polar ring hosts are statistically the same as those in the whole S0 sample, implying similar histories of multiple gas-accretion events from various directions.


    Energy Technology Data Exchange (ETDEWEB)

    Sil’chenko, Olga K., E-mail: [Sternberg Astronomical Institute, M.V. Lomonosov Moscow State University, Moscow, 119992 (Russian Federation); Isaac Newton Institute, Chile, Moscow Branch (Chile)


    I analyze statistics of the stellar population properties for stellar nuclei and bulges of nearby lenticular galaxies in different environments by using panoramic spectral data of the integral-field spectrograph SAURON retrieved from the open archive of the Isaac Newton Group. I also estimate the fraction of nearby lenticular galaxies having inner polar gaseous disks by exploring the volume-limited sample of early-type galaxies of the ATLAS-3D survey. By inspecting the two-dimensional velocity fields of the stellar and gaseous components with the running tilted-ring technique, I have found seven new cases of inner polar disks. Together with those, the frequency of inner polar disks in nearby S0 galaxies reaches 10%, which is much higher than the frequency of large-scale polar rings. Interestingly, the properties of the nuclear stellar populations in the inner polar ring hosts are statistically the same as those in the whole S0 sample, implying similar histories of multiple gas-accretion events from various directions.

  13. Cosmology from CMB Polarization with POLARBEAR and the Simons Array (United States)

    Barron, Darcy; POLARBEAR Collaboration


    POLARBEAR is a cosmic microwave background (CMB) polarization experiment located in the Atacama desert in Chile. The science goals of the POLARBEAR project are to do a deep search for CMB B-mode polarization created by inflationary gravitational waves, as well as characterize the CMB B-mode signal from gravitational lensing. POLARBEAR-1 started observations in 2012, and the POLARBEAR team has published a series of results from its first season of observations, including the first measurement of a non-zero B-mode polarization angular power spectrum, measured at sub-degree scales where the dominant signal is gravitational lensing of the CMB. Recently, we released an improved measurement of the B-mode polarization power spectrum, improving our band-power uncertainties by a factor of two, by adding new data from our second observing season and re-analyzing the combined data set.To further improve on these measurements, POLARBEAR is expanding to include an additional two telescopes with multi-chroic receivers observing at 95, 150, 220, and 270 GHz, known as the Simons Array. With high sensitivity and large sky coverage, the Simons Array will create a detailed survey of B-mode polarization, and its spectral information will be used to extract the CMB signal from astrophysical foregrounds. We will present the latest POLARBEAR results, as well as the status of development of the Simons Array and its expected capabilities.

  14. Realization of beam polarization at the linear collider and its application to EW processes

    Energy Technology Data Exchange (ETDEWEB)

    Franco-Sollova, F.


    -positron pairs. The polarization of the positrons is analyzed by reconverting them into photons and measuring the transmission asymmetry through a magnetized iron absorber. The analysis of the transmission asymmetry yields the following result for the June 2005 run: {delta}=0.0073 and the error is {delta}{delta}=0.0013; indicating the presence of positron polarization. The actual degree of polarization is still under study by the E-166 collaboration. (orig.)

  15. Polar heating in Saturn's thermosphere

    Directory of Open Access Journals (Sweden)

    C. G. A. Smith


    Full Text Available A 3-D numerical global circulation model of the Kronian thermosphere has been used to investigate the influence of polar heating. The distributions of temperature and winds resulting from a general heat source in the polar regions are described. We show that both the total energy input and its vertical distribution are important to the resulting thermal structure. We find that the form of the topside heating profile is particularly important in determining exospheric temperatures. We compare our results to exospheric temperatures from Voyager occultation measurements (Smith et al., 1983; Festou and Atreya, 1982 and auroral H3+ temperatures from ground-based spectroscopic observations (e.g. Miller et al., 2000. We find that a polar heat source is consistent with both the Smith et al. determination of T∞~400 K at ~30° N and auroral temperatures. The required heat source is also consistent with recent estimates of the Joule heating rate at Saturn (Cowley et al., 2004. However, our results show that a polar heat source can probably not explain the Festou and Atreya determination of T∞~800 K at ~4° N and the auroral temperatures simultaneously. Keywords. Ionosphere (Planetary ionosphere – Magnetospherica physics (Planetary magnetospheres – Meterology and atmospheric dynamics (Thermospheric dynamics

  16. YY Sex: a Polar Candidate (United States)

    Gabdeev, M. M.; Shimanskiy, V. V.; Borisov, N. V.; Tazieva, Z. R.


    We present spectroscopic investigations of a cataclysmic variable star, YY Sex. There are some uncertainties in the classification of this object. We calculate Doppler maps for Hβ and HeII λ4686Å and show that there is no sign of disk accretion in YY Sex. Consequently, we conclude that YY Sex is a polar.

  17. Hyperon polarization: theory and experiments

    Energy Technology Data Exchange (ETDEWEB)

    Magnin, J.; Simao, F.R.A.


    We give a brief review of the experimental situation concerning hyperon polarization. We mention also the current models developed to understand the experimental results and make some comments on some theoretical aspects contained in the Thomas precession model. (author). 8 ref.

  18. Verum focus and polar questions

    Directory of Open Access Journals (Sweden)

    Ion Giurgea


    Full Text Available We argue that some word order phenomena in Romanian and Sardinian are the result of a checkingoperation in the left periphery involving verum focus (i.e. focus on the polarity component of the sentence.In particular, this operation accounts for some word order patterns found in polar questions. In Romanian,polarity fronting is realized as head-movement of (V+T to a higher peripheral head which bears a Focusprobe.This licenses VS orders for predications in which VS is not allowed as a neutral order (i-levelpredicates, iteratives, generics. In Sardinian, an entire phrase headed by the lexical predicate (verbal nonfiniteform or non-verbal predicate is fronted before the auxiliary. We argue that this order is obtained bytwo movement operations, head-raising of Aux to Foc and movement of the predicate phrase to SpecFoc. Wealso present the semantics of polarity focus, distinguishing several types of focus (informational, emphatic,contrastive.

  19. Circular polarization observed in bioluminescence

    NARCIS (Netherlands)

    Wijnberg, Hans; Meijer, E.W.; Hummelen, J.C.; Dekkers, H.P.J.M.; Schippers, P.H.; Carlson, A.D.


    While investigating circular polarization in luminescence, and having found it in chemiluminescence, we have studied bioluminescence because it is such a widespread and dramatic natural phenomenon. We report here that left and right lanterns of live larvae of the fireflies, Photuris lucicrescens and

  20. Navegación polar


    Fernandez Cueva, Fernando


    El trabajo explica cómo es la navegación por los Polos, las altas latitudes, sus problemas y soluciones. Da una amplia visión de todo el entorno Polar, métodos de navegación, rutas y preparación

  1. Free radicals and polarized targets (United States)

    Bunyatova, E. I.


    Many free radicals were added to organic compounds in search of high proton and deuteron polarizations. Few found practical application. A short review is presented, and special attention is given to some stable nitroxyl radicals which have lately been admixed to organic compounds solid at room temperature, in particular to scintillators.

  2. Free radicals and polarized targets

    Energy Technology Data Exchange (ETDEWEB)

    Bunyatova, E.I. E-mail:


    Many free radicals were added to organic compounds in search of high proton and deuteron polarizations. Few found practical application. A short review is presented, and special attention is given to some stable nitroxyl radicals which have lately been admixed to organic compounds solid at room temperature, in particular to scintillators.

  3. Verum focus and polar questions

    Directory of Open Access Journals (Sweden)

    Ion Giurgea


    Full Text Available We argue that some word order phenomena in Romanian and Sardinian are the result of a checking operation in the left periphery involving verum focus (i.e. focus on the polarity component of the sentence. In particular, this operation accounts for some word order patterns found in polar questions. In Romanian, polarity fronting is realized as head-movement of (V+T to a higher peripheral head which bears a Focus-probe. This licenses VS orders for predications in which VS is not allowed as a neutral order (i-level predicates, iteratives, generics. In Sardinian, an entire phrase headed by the lexical predicate (verbal non-finite form or non-verbal predicate is fronted before the auxiliary. We argue that this order is obtained by two movement operations, head-raising of Aux to Foc and movement of the predicate phrase to SpecFoc. We also present the semantics of polarity focus, distinguishing several types of focus (informational, emphatic, contrastive.

  4. Dual polarized, heat spreading rectenna (United States)

    Epp, Larry W. (Inventor); Khan, Abdur R. (Inventor); Smith, R. Peter (Inventor); Smith, Hugh K. (Inventor)


    An aperture coupled patch splits energy from two different polarization components to different locations to spread heat. In addition, there is no physical electrical connection between the slot, patch and circuitry. The circuitry is located under a ground plane which shields against harmonic radiation back to the RF source.

  5. PIPER and Polarized Galactic Foregrounds (United States)

    Chuss, David


    In addition to probing inflationary cosmology, PIPER will measure the polarized dust emission from the Galaxy. PIPER will be capable of full (I,0,U,V) measurement over four frequency bands ' These measurements will provide insight into the physics of dust grains and a probe of the Galactic magnetic field on large and intermediate scales.

  6. High current polarized proton sources

    Energy Technology Data Exchange (ETDEWEB)

    Alessi, J.G.


    Polarized proton sources are now being used more frequently on linacs. In pulsed operation up to 10 mA of /rvec H//sup +/ and 0.4 mA of /rvec H//sup /minus// have been produced. The present status of these sources, and developments to reach even higher intensities, are reviewed. 39 refs., 1 tab.

  7. Shielding Electrostatic Fields in Polar Semiconductor Nanostructures (United States)

    Hönig, G. M. O.; Westerkamp, S.; Hoffmann, A.; Callsen, G.


    Polar semiconductor materials enable a variety of classic and quantum-light sources, which are optimized continuously. However, one key problem—the inherent electric crystal polarization of such materials—remains unsolved and deteriorates the radiative exciton decay rate. We suggest a sequence of reverse interfaces to compensate these polarization effects, while the polar, natural crystal growth direction is maintained. Former research approaches, like growth on less-polar crystal planes or even the stabilization of unnatural phases, never reached industrial maturity. In contrast, our concept provides a way for the development of ultrafast devices based on established growth processes for polar materials, while the electric potential landscape becomes adjustable.

  8. Polarized multiple scattering effect in Qweak (United States)

    Gal, Ciprian


    The Qweak experiment has measured the weak charge of the proton to unprecedented precision. In order to achieve this, all possible sources of systematic uncertainty had to be carefully controlled. This talk will present the work underpinning one of the leading systematic uncertainties in the measurement. Multiple scattering of transversely polarized electrons in the lead pre-radiator produced an additional asymmetry in the quartz integrating detectors. Analyzing powers inside the lead corresponding to Mott scattering and a two photon exchange model were implemented in a Geant4 simulation. A correction based on the physical differences between the left half and the right half of each Qweak detector was obtained. Potential implications to other parity violating experiments will be discussed.

  9. Polarization Sensitive Optical Coherence Tomography (United States)

    Park, B. Hyle; de Boer, Johannes F.

    Optical coherence tomography (OCT) is an interferometric technique capable of noninvasive high-resolution cross-sectional imaging by measuring the intensity of light reflected from within tissue [1]. This results in a noncontact imaging modality that provides images similar in scale and geometry to histology. Just as different stains can be used to enhance the contrast in histology, various extensions of OCT allow for visualization of features not readily apparent in traditional OCT. For example, optical Doppler tomography [2] can enable depth-resolved imaging of flow by observing differences in phase between successive depth scans [3-5]. This chapter will focus on polarization-sensitive OCT (PS-OCT), which utilizes depth-dependent changes in the polarization state of detected light to determine the light-polarization changing properties of a sample [6-11]. These properties, including birefringence, dichroism, and optic axis orientation, can be determined directly by studying the depth evolution of Stokes parameters [7-10, 12-16] or indirectly by using the changing reflected polarization states to first determine Jones or Mueller matrices [11, 17-21]. PS-OCT has been used in a wide variety of applications, including correlating burn depth with a decrease in birefringence [14], measuring the birefringence of the retinal nerve fiber layer [22, 23], and monitoring the onset and progression of caries lesions [24]. In this chapter, a discussion of polarization theory and its application to PS-OCTwill be followed by clinical uses of the technology and will conclude with mentionof more recent work and future directions of PS-OCT.

  10. A Theoretical Understanding of Circular Polarization Memory in Random Media (United States)

    Dark, Julia

    , linear polarization, and circular polarization decouple. From this result we conclude, that in the Fokker-Planck limit the scalar approximation is an appropriate leading order approximation. In the strong scattering and weak absorbing limit the vector radiative transport equation can be analyzed using boundary layer theory. In this case, the problem of light scattering in an optically thick medium is reduced to a 1D vRTE near the boundary and a 3D diffusion equation in the interior. We develop and implement a numerical solver for the boundary layer problem by using a discrete ordinate solver in the boundary layer and a spectral method to solve the diffusion approximation in the interior. We implement the method in Fortran 95 with external dependencies on BLAS, LAPACK, and FFTW. By analyzing the spectrum of the discretized vRTE in the boundary layer, we are able to predict the presence of circular polarization memory in a given medium.

  11. Ideological and Temporal Components of Network Polarization in Online Political Participatory Media

    CERN Document Server

    Garcia, David; Schweighofer, Simon; Serdült, Uwe; Schweitzer, Frank


    Political polarization is traditionally analyzed through the ideological stances of groups and parties, but it also has a behavioral component that manifests in the interactions between individuals. We present an empirical analysis of the digital traces of politicians in, a Swiss online platform focused on political activity, in which politicians interact by creating support links, comments, and likes. We analyze network polarization as the level of intra- party cohesion with respect to inter-party connectivity, finding that supports show a very strongly polarized structure with respect to party alignment. The analysis of this multiplex network shows that each layer of interaction contains relevant information, where comment groups follow topics related to Swiss politics. Our analysis reveals that polarization in the layer of likes evolves in time, increasing close to the federal elections of 2011. Furthermore, we analyze the internal social network of each party through metrics related to hierar...

  12. Magnetohydrodynamic instability of polar caps on accreting neutron stars (United States)

    Litwin, C.; Brown, E. F.; Rosner, R.


    We analyze equilibria and stability of the magnetically confined accreted matter in the polar cap on the surface of a neutron star. We find the equilibria by solving (both analytically and numerically) the Grad-Shafranov-like equation for the degenerate plasma in the neutron star ``ocean'' above the neutron star crust. Subsequently we employ the energy principle to analyze the stability of these equilibria to short-wavelength ballooning modes. We find that for strong magnetic fields (> 10^12 G) line-tying to the neutron star crust stabilizes these modes until the overpressure in the polar cap at the top of the neutron star crust exceeds the magnetic pressure by a factor ~ 8(a/h), where a and h are, respectively, the lateral extent of the polar cap and the density scale height. The most unstable modes are localized within a density scale height above the crust. We calculate the amount of mass that can be accumulated at the polar cap before the onset of instability. We also investigate the effect of incomplete degeneracy and nonuniform composition on stability.

  13. Polarized Fluorescence from Nitrogen Molecules Excited by Polarized Electron Impact (United States)

    Maseberg, J. W.; Furst, J. E.; Gay, T. J.


    We have measured the optical excitation function and relative Stokes parameters for 388±5 nm fluorescence from spin-polarized electron impact excitation of molecular N2. Specifically, the circular polarization fraction normalized to the incident electron spin, P3/Pe, was found to be +1(5)% at an electron energy of 30eV. This result, even though it contains contributions from 6 different triplet spectral lines, is consistent with the data of the Münster group [1] who measured the N2 337 nm C3πu - B3πg (ν'=0, ν=0) transition and found P3 Mette et al., Verhandl. DPG (VI) 29, 462 (1994). [2] A.S. Green et al., Phys. Rev. Lett. 92, 093201 (2004).

  14. First attempt of the measurement of the beam polarization at an accelerator with the optical electron polarimeter POLO

    CERN Document Server

    Collin, B; Essabaa, S; Frascaria, R; Gacougnolle, R; Kunne, Ronald Alexander; Aulenbacher, K; Tioukine, V


    The conventional methods for measuring the polarization of electron beams are either time consuming, invasive or accurate only to a few percent. We developped a method to measure electron beam polarization by observing the light emitted by argon atoms following their excitation by the impact of polarized electrons. The degree of circular polarization of the emitted fluorescence is directly related to the electron polarization. We tested the polarimeter on a test GaAs source available at the MAMI electron accelerator in Mainz, Germany. The polarimeter determines the polarization of a 50 keV electron beam decelerated to a few eV and interacting with an effusive argon gas jet. The resulting decay of the excited states produces the emission of a circularly polarized radiation line at 811.5 nm which is observed and analyzed.

  15. Design and analysis of a photonic crystal fiber based polarization filter using surface plasmon resonance (United States)

    Yogalakshmi, S.; Selvendran, S.; Sivanantha Raja, A.


    A photonic crystal fiber with an active metal nanowire is proposed to act as a polarization filter based on the principle of plasmonic resonance. The light launched into the silica core gets coupled to gold wire inducing surface plasmon resonance, filtering one of the two orthogonally polarized light waves in the third optical communication window. This polarization filtering characteristic is analyzed using the finite element method. The change in the performance behaviour of the proposed filter is investigated by increasing the number of embedded gold wires, altering their positions and varying the diameter of gold wire. It is found that enhanced absorption of the core guided mode is achieved by replacing the filled metal nanowire with a metal coating around the air hole. Filtering of any or both polarizations can be attained by suitably positioning the metal wires. Confinement loss as high as 348.55 and 302 dB cm-1 for y-polarized and x-polarized lights respectively are attained at 1.52 and 1.56 μm respectively for single gold wire. The filter acts as a single polarization filter filtering x-polarized light with a confinement loss value of 187.67 dB cm-1 when two gold nanowires are placed adjacently. The same structure acts as the filter for y-polarized light by employing gold coating exhibiting an increased confinement loss of 406.34 dB cm-1 at 1.64 μm.

  16. Beamforming of Joint Polarization-Space Matched Filtering for Conformal Array

    Directory of Open Access Journals (Sweden)

    Lutao Liu


    Full Text Available Due to the polarization mismatch of the antenna, the received signal suffers from energy loss. The conventional beamforming algorithms could not be applied to the conformal array because of the varying curvature. In order to overcome the energy loss of the received signal, a novel joint polarization-space matched filtering algorithm for cylindrical conformal array is proposed. First, the snapshot data model of the conformal polarization sensitive array is analyzed. Second, the analytical expression of polarization sensitive array beamforming is derived. Linearly constrained minimum variance (LCMV beamforming technique is facilitated for the cylindrical conformal array. Third, the idea of joint polarization-space matched filtering is presented, and the principle of joint polarization-space matched filtering is discussed in detail. Theoretical analysis and computer simulation results verify that the conformal polarization sensitive array is more robust than the ordinary conformal array. The proposed algorithm can improve the performance when signal and interference are too close. It can enhance the signal-to-noise ratio (SNR by adjusting the polarization of the elements of the conformal array, which matches the polarization of the incident signal.

  17. Suppression of Cross-Polarization of the Microstrip Integrated Balun-Fed Printed Dipole Antenna

    Directory of Open Access Journals (Sweden)

    Huang Jingjian


    Full Text Available The high cross-polarization of the microstrip integrated balun-fed printed dipole antenna cannot meet the demands of many engineering applications. This kind of antennas has high cross-polarization levels (about −20 dB. And we find that the high cross-polarization radiation is mainly produced by the microstrip integrated balun rather than the dipole itself. The very limited method to lower the cross-polarization level of this kind of antennas is to reduce the substrate thickness. In this paper, to improve the low cross-polarized performance, firstly, an equivalent model is presented to analyze the cross-polarization radiation. Secondly, a novel structure with low cross-polarization is proposed. The microstrip integrated balun is enclosed by a center slotted cavity. The E-field of the microstrip integrated balun is transformed parallel to the dipole arms by the slot, so the radiation of the cross-polarized component is suppressed. Measured results show that this structure can achieve a bandwidth wider than 40% while reducing the cross-polarization level to less than −35 dB within the frequency band.

  18. Underwater partial polarization signatures from the shallow water real-time imaging polarimeter (SHRIMP) (United States)

    Taylor, James S., Jr.; Davis, P. S.; Wolff, Lawrence B.


    Research has shown that naturally occurring light outdoors and underwater is partially linearly polarized. The polarized components can be combined to form an image that describes the polarization of the light in the scene. This image is known as the degree of linear polarization (DOLP) image or partial polarization image. These naturally occurring polarization signatures can provide a diver or an unmanned underwater vehicle (UUV) with more information to detect, classify, and identify threats such as obstacles and/or mines in the shallow water environment. The SHallow water Real-time IMaging Polarimeter (SHRIMP), recently developed under sponsorship of Dr. Tom Swean at the Office of Naval Research (Code 321OE), can measure underwater partial polarization imagery. This sensor is a passive, three-channel device that simultaneously measures the three components of the Stokes vector needed to determine the partial linear polarization of the scene. The testing of this sensor has been completed and the data has been analyzed. This paper presents performance results from the field-testing and quantifies the gain provided by the partial polarization signature of targets in the Very Shallow Water (VSW) and Surf Zone (SZ) regions.

  19. Portable Programmable Multifunction Body Fluids Analyzer Project (United States)

    National Aeronautics and Space Administration — Advanced Liquid Logic proposes to develop a very capable analyzer based on its digital microfluidic technology. Such an analyzer would be:  Capable of both...

  20. Can invertebrates see the e-vector of polarization as a separate modality of light? (United States)

    Labhart, Thomas


    The visual world is rich in linearly polarized light stimuli, which are hidden from the human eye. But many invertebrate species make use of polarized light as a source of valuable visual information. However, exploiting light polarization does not necessarily imply that the electric (e)-vector orientation of polarized light can be perceived as a separate modality of light. In this Review, I address the question of whether invertebrates can detect specific e-vector orientations in a manner similar to that of humans perceiving spectral stimuli as specific hues. To analyze e-vector orientation, the signals of at least three polarization-sensitive sensors (analyzer channels) with different e-vector tuning axes must be compared. The object-based, imaging polarization vision systems of cephalopods and crustaceans, as well as the water-surface detectors of flying backswimmers, use just two analyzer channels. Although this excludes the perception of specific e-vector orientations, a two-channel system does provide a coarse, categoric analysis of polarized light stimuli, comparable to the limited color sense of dichromatic, 'color-blind' humans. The celestial compass of insects employs three or more analyzer channels. However, that compass is multimodal, i.e. e-vector information merges with directional information from other celestial cues, such as the solar azimuth and the spectral gradient in the sky, masking e-vector information. It seems that invertebrate organisms take no interest in the polarization details of visual stimuli, but polarization vision grants more practical benefits, such as improved object detection and visual communication for cephalopods and crustaceans, compass readings to traveling insects, or the alert 'water below!' to water-seeking bugs. © 2016. Published by The Company of Biologists Ltd.

  1. Silicon photonic thermometer operating on multiple polarizations

    DEFF Research Database (Denmark)

    Guan, Xiaowei; Wang, Xiaoyan; Frandsen, Lars Hagedorn


    A silicon photonics optical thermometer simultaneously operating on the multiple polarizations is designed and experimentally demonstrated. Measured sensitivities are 86pm/°C and 48pm/°C for the transverse-electric and transverse-magnetic polarizations, respectively.......A silicon photonics optical thermometer simultaneously operating on the multiple polarizations is designed and experimentally demonstrated. Measured sensitivities are 86pm/°C and 48pm/°C for the transverse-electric and transverse-magnetic polarizations, respectively....

  2. Polarization control based interference microwave photonic filters (United States)

    Madziar, Krzysztof; Galwas, Bogdan


    In this paper we present a concept of multi-line Microwave Photonic Filter (MPF) based on polarization beam splitting and polarization control in each line. Coefficients of investigated filter are determined by attenuation of its lines and that on the other hand can be manipulated by change of the polarization in the fiber. Presented results involve scattering parameters (S21) measurements of optical path over polarization control unit rotation, scattering parameters (S21) characteristics of investigated filter and transmission optimization capabilities.

  3. Polarization properties of photonic bandgap fibers

    DEFF Research Database (Denmark)

    Broeng, Jes; Libori, Stig E. Barkou; Bjarklev, Anders Overgaard


    We present the first analysis of polarization properties of photonic bandgap fibers. Strong birefringence may be obtained for modest non-uniformities in and around the core region, suggesting the use of photonic bandgap fibers as polarization maintaining components.......We present the first analysis of polarization properties of photonic bandgap fibers. Strong birefringence may be obtained for modest non-uniformities in and around the core region, suggesting the use of photonic bandgap fibers as polarization maintaining components....

  4. Statistics of polarization speckle: theory versus experiment

    DEFF Research Database (Denmark)

    Wang, Wei; Hanson, Steen Grüner; Takeda, Mitsuo


    In this paper, we reviewed our recent work on the statistical properties of polarization speckle, described by stochastic Stokes parameters fluctuating in space. Based on the Gaussian assumption for the random electric field components and polar-interferometer, we investigated theoretically...... and experimentally the statistics of Stokes parameters of polarization speckle, including probability density function of Stokes parameters with the spatial degree of polarization, autocorrelation of Stokes vector and statistics of spatial derivatives for Stokes parameters....

  5. A Polarization Sequence for Type Ia Supernovae?


    Meng, Xiangcun; Zhang, Jujia; Han, Zhanwen


    Early polarization observations on Type Ia supernovae (SNe Ia) may reveal the geometry of supernova ejecta, and then put constraints on their explosion mechanism and their progenitor model. We performed a literature search of SNe Ia with polarization measurements and determined the polarization and relative equivalent width (REW) of Si II 635.5-nm absorption feature at -5 days after the maximum light. We found that either the distribution of observed polarization degree is bimodal, i.e. the b...

  6. Baryon spectroscopy with polarization observables from CLAS

    Energy Technology Data Exchange (ETDEWEB)

    Strauch, Steffen [Univ. of South Carolina, Columbia, SC (United States)


    Meson photoproduction is an important tool in the study of baryon resonances. The spectrum of broad and overlapping nucleon excitations can be greatly clarified by use of polarization observables. The N* program at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS) includes experimental studies with linearly and circularly polarized tagged photon beams, longitudinally and transversely polarized nucleon targets, and recoil polarizations. An overview of these experimental studies and recent results will be given.

  7. Cassini ISS observation of Saturn's north polar vortex and comparison to the south polar vortex (United States)

    Sayanagi, Kunio M.; Blalock, John J.; Dyudina, Ulyana A.; Ewald, Shawn P.; Ingersoll, Andrew P.


    We present analyses of Saturn's north pole using high-resolution images captured in late 2012 by the Cassini spacecraft's Imaging Science Subsystem (ISS) camera. The images reveal the presence of an intense cyclonic vortex centered at the north pole. In the red and green visible continuum wavelengths, the north polar region exhibits a cyclonically spiraling cloud morphology extending from the pole to 85°N planetocentric latitude, with a 4700 km radius. Images captured in the methane bands, which sense upper tropospheric haze, show an approximately circular hole in the haze extending up to 1.5° latitude away from the pole. The spiraling morphology and the "eye"-like hole at the center are reminiscent of a terrestrial tropical cyclone. In the System III reference frame (rotation period of 10h39m22.4s, Seidelmann et al. 2007; Archinal et al. 2011), the eastward wind speed increases to about 140 m s-1 at 89°N planetocentric latitude. The vorticity is (6.5± 1.5) × 10-4 s-1 at the pole, and decreases to (1.3± 1.2) × 10-4 s-1 at 89°N. In addition, we present an analysis of Saturn's south polar vortex using images captured in January 2007 to compare its cloud morphology to the north pole. The set of images captured in 2007 includes filters that have not been analyzed before. Images captured in the violet filter (400 nm) also reveal a bright polar cloud. The south polar morphology in 2007 was more smooth and lacked the small clouds apparent around the north pole in 2012. Saturn underwent equinox in August 2009. The 2007 observation captured the pre-equinox south pole, and the 2012 observation captured the post-equinox north pole. Thus, the observed differences between the poles are likely due to seasonal effects. If these differences indeed are caused by seasonal effects, continuing observations of the summer north pole by the Cassini mission should show a formation of a polar cloud that appears bright in short-wavelength filters.

  8. United States Naval Academy Polar Science Program; Undergraduate Research and Outreach in Polar Environments (United States)

    Woods, J. E.


    The United States Naval Academy (USNA) Polar Science Program (PSP), has been very active completing its own field campaign out of Barrow, AK, sent students to the South Pole, participated in STEM activities and educated over 100 future Naval Officers about the Polar Regions. Each activity is uniquely different, but has the similar undertone of sharing the recent rapid changes in the Cryosphere to a wide range of audiences. There is further room for development and growth through future field campaigns and new collaborations. The Naval Academy Ice Experiment (NAICEX) 2013 was based out of the old Naval Arctic Research Laboratory (NARL) in Barrow, AK. In joint collaboration with the University of Delaware, University of Washington, and Naval Research Laboratory we successfully took multiple measurements for over a week on the fast ice just offshore. Five undergraduate students from USNA, as well as 3 graduate students from University of Delaware participated, as well as multiple professors and instructors from each institution. Data collected during the experiment will be used in capstone courses and thesis research. There was also an outreach component to the experiment, where local students from Barrow H.S. have been assigned to the USNA ice observations project for their own high school course work. Local students will be analyzing data that will contribute into the larger research effort at USNA through coordinated remote efforts and participation in future field experiments. The USNA STEM office is one of the most robust in the entire country. The USNA PSP is active within this program by developing polar specific modules that are integrated varying length outreach opportunities from a few hours to week long camps. USNA PSP also engages in educator training that is held at the Naval Academy each summer. Through this program of educating the educators, the far reaching levels of awareness are multiplied exponentially. Also, the USNA Oceanography Department has

  9. Electronic polarization-division demultiplexing based on digital signal processing in intensity-modulation direct-detection optical communication systems. (United States)

    Kikuchi, Kazuro


    We propose a novel configuration of optical receivers for intensity-modulation direct-detection (IM · DD) systems, which can cope with dual-polarization (DP) optical signals electrically. Using a Stokes analyzer and a newly-developed digital signal-processing (DSP) algorithm, we can achieve polarization tracking and demultiplexing in the digital domain after direct detection. Simulation results show that the power penalty stemming from digital polarization manipulations is negligibly small.

  10. Fractal analysis of polar bear hairs

    Directory of Open Access Journals (Sweden)

    Wang Qing-Li


    Full Text Available Hairs of a polar bear (Ursus maritimus are of superior properties such as the excellent thermal protection. Why do polar bears can resist such cold environment? The paper concludes that its fractal porosity plays an important role, and its fractal dimensions are very close to the golden mean, 1.618, revealing the possible optimal structure of polar bear hair.

  11. Thin Scintillating Polarized Targets for Spin Physics (United States)

    van den Brandt, B.; Bunyatova, E. I.; Hautle, P.; Konter, J. A.


    At PSI polarized scintillating targets are available since 1996. Proton polarizations of more than 80%, and deuteron polarizations of 25% in polystyrene-based scintillators can be reached under optimum conditions in a vertical dilution refrigerator with optical access, suited for nuclear and particle physics experiments. New preparation procedures allow to provide very thin polarizable scintillating targets and widen the spectrum of conceivable experiments.

  12. Quasar polarization with ultralight (pseudo-)scalars

    Indian Academy of Sciences (India)

    Abstract. Recently, it was shown that the absence of circular polarization of visible light from quasars severely constrains the interpretation of axion-like particles (ALPs) as a solution for the generation of linear polarization. Furthermore, the new observation of linear polarization in radio wavelength from quasars, similar to ...

  13. Quasar polarization with ultralight (pseudo-) scalars

    Indian Academy of Sciences (India)

    Recently, it was shown that the absence of circular polarization of visible light from quasars severely constrains the interpretation of axion-like particles (ALPs) as a solution for the generation of linear polarization. Furthermore, the new observation of linear polarization in radio wavelength from quasars, similar to the earlier ...

  14. The Large Scale Structure: Polarization Aspects

    Indian Academy of Sciences (India)

    Polarized radio emission is detected at various scales in the Universe. In this document, I will briefly review our knowledge on polarized radio sources in galaxy clusters and at their outskirts, emphasizing the crucial information provided by the polarized signal on the origin and evolution of such sources. Successively, I will ...

  15. Configuration Manual Polarized Proton Collider at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S. Y.; Luccio, A.; MacKay, W. W.; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Svirida, D.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A.


    In this report we present our design to accelerate and store polarized protons in RHIC, with the level of polarization, luminosity, and control of systematic errors required by the approved RHIC spin physics program. We provide an overview of the physics to be studied using RHIC with polarized proton beams, and a brief description of the accelerator systems required for the project.


    Energy Technology Data Exchange (ETDEWEB)



    In this report, the authors present their design to accelerate and store polarized protons in RHIC, with the level of polarization, luminosity, and control of systematic errors required by the approved RHIC spin physics program. They provide an overview of the physics to be studied using RHIC with polarized proton beams, and a brief description of the accelerator systems required for the project.

  17. Partial Polarization in Interfered Plasmon Fields

    Directory of Open Access Journals (Sweden)

    P. Martínez Vara


    Full Text Available We describe the polarization features for plasmon fields generated by the interference between two elemental surface plasmon modes, obtaining a set of Stokes parameters which allows establishing a parallelism with the traditional polarization model. With the analysis presented, we find the corresponding coherence matrix for plasmon fields incorporating to the plasmon optics the study of partial polarization effects.

  18. Microwave-gated dynamic nuclear polarization

    DEFF Research Database (Denmark)

    Bornet, Aurélien; Pinon, Arthur; Jhajharia, Aditya


    Dissolution dynamic nuclear polarization (D-DNP) has become a method of choice to enhance signals in nuclear magnetic resonance (NMR). Recently, we have proposed to combine cross-polarization (CP) with D-DNP to provide high polarization P((13)C) in short build-up times. In this paper, we show...

  19. The ILC polarized electron source

    CERN Document Server

    Brachmann, Axel; Garwin, Edward; Kirby, Robert; Luh Dah An; Maruyama, Takashi; Prepost, Richard; Schultz, David; Sheppard, John


    The SLC polarized electron source (PES) can meet the expected requirements of the International Linear Collider (ILC) for polarization, charge and lifetime. However, experience with newer and successful PES designs at JLAB, Mainz and elsewhere can be incorporated into a first-generation ILC source that will emphasize reliability and stability without compromising the photocathode performance. The long pulse train for the ILC may introduce new challenges for the PES, and in addition more reliable and stable operation of the PES may be achievable if appropriate R&D is carried out for higher voltage operation and for a simpler load-lock system. The outline of the R&D program currently taking shape at SLAC and elsewhere is discussed. The principal components of the proposed ILC PES, including the laser system necessary for operational tests, are described.

  20. Polarization Properties of Laser Solitons

    Directory of Open Access Journals (Sweden)

    Pedro Rodriguez


    Full Text Available The objective of this paper is to summarize the results obtained for the state of polarization in the emission of a vertical-cavity surface-emitting laser with frequency-selective feedback added. We start our research with the single soliton; this situation presents two perpendicular main orientations, connected by a hysteresis loop. In addition, we also find the formation of a ring-shaped intensity distribution, the vortex state, that shows two homogeneous states of polarization with very close values to those found in the soliton. For both cases above, the study shows the spatially resolved value of the orientation angle. It is important to also remark the appearance of a non-negligible amount of circular light that gives vectorial character to all the different emissions investigated.

  1. The ILC Polarized Electron Source

    Energy Technology Data Exchange (ETDEWEB)

    Brachmann, A.


    The SLC polarized electron source (PES) can meet the expected requirements of the International Linear Collider (ILC) for polarization, charge and lifetime. However, experience with newer and successful PES designs at JLAB, Mainz, Nagoya and elsewhere can be incorporated into a first-generation ILC source that will emphasize reliability and stability without compromising the photocathode performance. The long pulse train for the ILC may introduce new challenges for the PES, and in addition more reliable and stable operation of the PES may be achievable if appropriate R&D is carried out for higher voltage operation and for a simpler load-lock system. The outline of the R&D program currently taking shape at SLAC and elsewhere is discussed. The principal components of the proposed ILC PES, including the laser system necessary for operational tests, are described.

  2. Three-dimensional polarization algebra. (United States)

    R Sheppard, Colin J; Castello, Marco; Diaspro, Alberto


    If light is focused or collected with a high numerical aperture lens, as may occur in imaging and optical encryption applications, polarization should be considered in three dimensions (3D). The matrix algebra of polarization behavior in 3D is discussed. It is useful to convert between the Mueller matrix and two different Hermitian matrices, representing an optical material or system, which are in the literature. Explicit transformation matrices for converting the column vector form of these different matrices are extended to the 3D case, where they are large (81×81) but can be generated using simple rules. It is found that there is some advantage in using a generalization of the Chandrasekhar phase matrix treatment, rather than that based on Gell-Mann matrices, as the resultant matrices are of simpler form and reduce to the two-dimensional case more easily. Explicit expressions are given for 3D complex field components in terms of Chandrasekhar-Stokes parameters.

  3. Spin-flipping polarized electrons

    Directory of Open Access Journals (Sweden)

    V. S. Morozov


    Full Text Available We recently used a prototype rf dipole magnet to study the spin flipping of a 669 MeV horizontally polarized electron beam stored in the presence of a nearly full Siberian snake in the new MIT-Bates storage ring. We flipped the spin by ramping the rf dipole's frequency through an rf-induced depolarizing resonance. After optimizing the frequency ramp parameters, we used multiple spin flipping to measure a spin-flip efficiency of 94.5±2.5%. The spin-flip efficiency was apparently limited by the field strength in the air-core prototype rf dipole magnet. This unexpectedly high efficiency indicates that very efficient spin flipping of the ring's stored polarized electron beam should be possible using the much stronger ferrite spin flipper, which is now being built by the University of Michigan's Spin Physics Center.

  4. Itinerant Ferromagnetism in a Polarized Two-Component Fermi Gas

    DEFF Research Database (Denmark)

    Massignan, Pietro; Yu, Zhenhua; Bruun, Georg


    We analyze when a repulsively interacting two-component Fermi gas becomes thermodynamically unstable against phase separation. We focus on the strongly polarized limit, where the free energy of the homogeneous mixture can be calculated accurately in terms of well-defined quasiparticles, the repul...... of the minority atoms, raising the prospects of detecting the transition to the elusive itinerant ferromagnetic state with ultracold atoms....

  5. Vacuum polarization and Hawking radiation (United States)

    Rahmati, Shohreh

    Quantum gravity is one of the interesting fields in contemporary physics which is still in progress. The purpose of quantum gravity is to present a quantum description for spacetime at 10-33cm or find the 'quanta' of gravitational interaction.. At present, the most viable theory to describe gravitational interaction is general relativity which is a classical theory. Semi-classical quantum gravity or quantum field theory in curved spacetime is an approximation to a full quantum theory of gravity. This approximation considers gravity as a classical field and matter fields are quantized. One interesting phenomena in semi-classical quantum gravity is Hawking radiation. Hawking radiation was derived by Stephen Hawking as a thermal emission of particles from the black hole horizon. In this thesis we obtain the spectrum of Hawking radiation using a new method. Vacuum is defined as the possible lowest energy state which is filled with pairs of virtual particle-antiparticle. Vacuum polarization is a consequence of pair creation in the presence of an external field such as an electromagnetic or gravitational field. Vacuum polarization in the vicinity of a black hole horizon can be interpreted as the cause of the emission from black holes known as Hawking radiation. In this thesis we try to obtain the Hawking spectrum using this approach. We re-examine vacuum polarization of a scalar field in a quasi-local volume that includes the horizon. We study the interaction of a scalar field with the background gravitational field of the black hole in the desired quasi-local region. The quasi-local volume is a hollow cylinder enclosed by two membranes, one inside the horizon and one outside the horizon. The net rate of particle emission can be obtained as the difference of the vacuum polarization from the outer boundary and inner boundary of the cylinder. Thus we found a new method to derive Hawking emission which is unitary and well defined in quantum field theory.

  6. Polarization phenomena in quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J. [Stanford Univ., CA (United States)


    The author discusses a number of interrelated hadronic spin effects which test fundamental features of perturbative and nonperturbative QCD. For example, the anomalous magnetic moment of the proton and the axial coupling g{sub A} on the nucleon are shown to be related to each other for fixed proton radius, independent of the form of the underlying three-quark relativistic quark wavefunction. The renormalization scale and scheme ambiguities for the radiative corrections to the Bjorken sum rule for the polarized structure functions can be eliminated by using commensurate scale relations with other observables. Other examples include (a) new constraints on the shape and normalization of the polarized quark and gluon structure functions of the proton at large and small x{sub bj}; (b) consequences of the principle of hadron retention in high x{sub F} inclusive reactions; (c) applications of hadron helicity conservation to high momentum transfer exclusive reactions; and (d) the dependence of nuclear structure functions and shadowing on virtual photon polarization. The author also discusses the implications of a number of measurements which are in striking conflict with leading-twist perturbative QCD predictions, such as the extraordinarily large spin correlation A{sub NN} observed in large angle proton-proton scattering, the anomalously large {rho}{pi} branching ratio of the J/{psi}, and the rapidly changing polarization dependence of both J/{psi} and continuum lepton pair hadroproduction observed at large x{sub F}. The azimuthal angular dependence of the Drell-Yan process is shown to be highly sensitive to the projectile distribution amplitude, the fundamental valence light-cone wavefunction of the hadron.

  7. The bi-polar Any


    Jayez, Jacques; Tovena, Lucia


    Handout d'une communication à Negation : Syntax, Semantics and Pragmatics, ESRI, Salford, 30 oct. -1st nov. 1998; The distribution of "any" may be best understood by replacing the traditional NPI and FC partition with a classification that groups together positive and negative polarity (strong) manifestations while keeping apart indiscriminative (weak) uses. The talk has concentrated on strong "any" and has shown that analyses based on scalar and on modal properties of "any" both support this...

  8. Polarity of mature human odontoblasts. (United States)

    Tjäderhane, L; Koivumäki, S; Pääkkönen, V; Ilvesaro, J; Soini, Y; Salo, T; Metsikkö, K; Tuukkanen, J


    Odontoblast polarization is based on histological appearance as columnar cells with asymmetric disposition of organelles and plasma membrane domains. However, little is known about the odontoblast plasma membrane organization. We investigated odontoblast membrane polarity using influenza virus hemagglutinin and vesicular stomatitis virus glycoprotein as model proteins in mature human odontoblast organ culture. We also examined the distribution patterns of aquaporin 4 and 5, which are basolateral and apical proteins in epithelial cells, respectively. Confocal microscopy immunofluorescence and electron microscopy demonstrated that the apical markers located at the surface toward pulp and basolateral markers located at the plasma membrane of odontoblast processes. Therefore, odontoblast plasma membrane polarity was different from that in epithelial cells. Also, certain lectins stained odontoblast processes while others stained the soma, reflecting the different natures of their membrane domains. Strong ZO-1 and weaker claudin expression suggest weak tight junctions in the odontoblasts. TGF-β1 showed a tendency to reinstate the expression of selected TJ genes, indicating that TGF-β1 may control odontoblast cell layer integrity by controlling tight junction protein expression.

  9. Measuring Gravitation Using Polarization Spectroscopy (United States)

    Matsko, Andrey; Yu, Nan; Maleki, Lute


    A proposed method of measuring gravitational acceleration would involve the application of polarization spectroscopy to an ultracold, vertically moving cloud of atoms (an atomic fountain). A related proposed method involving measurements of absorption of light pulses like those used in conventional atomic interferometry would yield an estimate of the number of atoms participating in the interferometric interaction. The basis of the first-mentioned proposed method is that the rotation of polarization of light is affected by the acceleration of atoms along the path of propagation of the light. The rotation of polarization is associated with a phase shift: When an atom moving in a laboratory reference interacts with an electromagnetic wave, the energy levels of the atom are Doppler-shifted, relative to where they would be if the atom were stationary. The Doppler shift gives rise to changes in the detuning of the light from the corresponding atomic transitions. This detuning, in turn, causes the electromagnetic wave to undergo a phase shift that can be measured by conventional means. One would infer the gravitational acceleration and/or the gradient of the gravitational acceleration from the phase measurements.

  10. Optimization of polarizer azimuth in improving signal-to-noise ratio in Kerr microscopy. (United States)

    Wang, X; Lian, J; Xu, X J; Li, X; Li, P; Li, M M; Wang, Y; Liu, Y X


    The magneto optical Kerr effect (MOKE) is a widely used technique in magnetic domain imaging for its high surface sensitivity and external magnetic compatibility. Optimization of Kerr microscopy will improve the detecting sensitivity and provide high-quality domain images. In this work, we provide a method to optimize the polarizer azimuth in improving the signal-to-noise ratio (S/N) in longitudinal Kerr microscopy with the generalized magneto optical ellipsometry. Detailed analysis of the MOKE signal and the noise components are provided to study the optimum polarizer and analyzer azimuth combinations. Results show that, for a fixed polarizer angle 1°, the laser intensity noise and the shot noise, which vary with the input laser power, have a similar amplitude and decline with the analyzer azimuth increasing. When the analyzer is set at the extinction place, the Johnson noise plays a dominate role in the total noise. Then, the S/N values are calculated to find the optimum polarizer and analyzer azimuth. Results show that the optimum polarizer and analyzer azimuth combination for Permalloy is (18.35°, 68.35°) under an incident angle of 45°. After that, the S/N of 200 nm Permalloy at different analyzer angles with the polarizer azimuth set at 18.35° is measured to verify the validity of the simulation results. At last, the S/N at different incident angles is calculated. Results show that the optimum incident angle of 200 nm Permalloy film to improve the S/N is 70.35° under the polarizer and analyzer angles set at the optimal combinations (18.35°, 68.35°).

  11. Anti-Lambda Polarization in High Energy pp Collisions withPolarized Beams

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qing-hua; Liang, Zuo-tang; Sichtermann, Ernst


    We study the polarization of the anti-Lambda particle in polarized high energy pp collisions at large transverse momenta. The anti-Lambda polarization is found to be sensitive to the polarization of the anti-strange sea of the nucleon. We make predictions using different parameterizations of the polarized quark distribution functions. The results show that the measurement of longitudinal anti-Lambda polarization can distinguish different parameterizations, and that similar measurements in the transversely polarized case can give some insights into the transversity distribution of the anti-strange sea of nucleon.

  12. Characterizing forest stands with multi-incidence angle and multi-polarized SAR data (United States)

    Hoffer, R. M.; Lozano-Garcia, D. F.; Gillespie, D. D.


    The potential for using HH-polarized L-band SAR data obtained at different incidence angles from satellite altitudes to identify and map different forest cover types and stand density classes is studied. Reasonably accurate results are obtained if the speckle characteristics of the data are suppressed by low-pass spatial filters and a contextual classification algorithm. Multipolarized L-band SAR data obtained from aircraft altitudes over the same test site are also analyzed to assess the relationships between polarization and forest stand characteristics. It is found that incidence angle controls, to a very large extent, the characteristics of the data and the type of information that can be obtained from L-band, HH-polarized satellite SAR data. Cross-polarization of L-band SAR data enhances and differentiates various forest stand characteristics which cannot be defined using only the like-polarized data, and vice-versa.

  13. Ab-initio study of the relation between electric polarization and electric field gradients in ferroelectrics

    CERN Document Server

    Gonçalves, J N; Correia, J G; Butz, T; Picozzi, S; Fenta, A S; Amaral, V S


    The hyperfine interaction between the quadrupole moment of atomic nuclei and the electric field gradient (EFG) provides information on the electronic charge distribution close to a given atomic site. In ferroelectric materials, the loss of inversion symmetry of the electronic charge distribution is necessary for the appearance of the electric polarization. We present first-principles density functional theory calculations of ferroelectrics such as BaTiO$_{3}$, KNbO$_{3}$, PbTiO$_{3}$ and other oxides with perovskite structures, by focusing on both EFG tensors and polarization. We analyze the EFG tensor properties such as orientation and correlation between components and their relation with electric polarization. This work supports previous studies of ferroelectric materials where a relation between EFG tensors and polarization was observed, which may be exploited to study the ferroelectric order when standard techniques to measure polarization are not easily applied.

  14. Proton-proton elastic scattering excitation functions at intermediate energies: Cross sections and analyzing powers

    Energy Technology Data Exchange (ETDEWEB)

    Hinterberger, F.; Rohdjess, H.; Altmeier, M.; Bauer, F.; Bisplinghoff, J.; Buesser, K.; Busch, M.; Colberg, T.; Diehl, O.; Dohrmann, F.; Engelhardt, H.P.; Eversheim, P.D.; Felden, O.; Gebel, R.; Glende, M.; Greiff, J.; Gross-Hardt, R.; Jahn, R.; Jonas, E.; Krause, H.; Langkau, R.; Lindemann, T.; Lindlein, J.; Maier, R.; Maschuw, R.; Mayer-Kuckuk, T.; Meinerzhagen, A.; Naehle, O.; Prasuhn, D.; Rosendaal, D.; Rossen, P. von; Schirm, N.; Schulz-Rojahn, M.; Schwarz, V.; Scobel, W.; Trelle, H.J.; Weise, E.; Wellinghausen, A.; Woller, K.; Ziegler, R


    The EDDA experiment at the cooler synchrotron COSY measures proton-proton elastic scattering excitation functions in the momentum range 0.8 - 3.4 GeV/c. In phase 1 of the experiment, spin-averaged differential cross sections were measured continuously during acceleration with an internal polypropylene (CH{sub 2}) fiber target, taking particular care to monitor luminosity as a function of beam momentum. In phase 2, excitation functions of the analyzing power A{sub N} and the polarization correlation parameters A{sub NN}, A{sub SS} and A{sub SL} are measured using a polarized proton beam and a polarized atomic hydrogen beam target. The paper presents recent d{sigma}/d{omega} and A{sub N} data. The results provide excitation functions and angular distributions of high precision and internal consistency. No evidence for narrow structures was found. The data are compared to recent phase shift solutions.

  15. Proton-Proton Elastic Scattering Excitation Functions at Intermediate Energies: Cross Sections and Analyzing Powers (United States)

    Hinterberger, F.; Rohdjeß, H.; Altmeier, M.; Bauer, F.; Bisplinghoff, J.; Büßer, K.; Busch, M.; Colberg, T.; Diehl, O.; Dohrmann, F.; Engelhardt, H. P.; Eversheim, P. D.; Felden, O.; Gebel, R.; Glende, M.; Greiff, J.; Groß-Hardt, R.; Hinterberger, F.; Jahn, R.; Jonas, E.; Krause, H.; Langkau, R.; Lindemann, T.; Lindlein, J.; Maier, R.; Maschuw, R.; Mayer-Kuckuk, T.; Meinerzhagen, A.; Nähle, O.; Prasuhn, D.; Rohdjeß, H.; Rosendaal, D.; von Rossen, P.; Schirm, N.; Schulz-Rojahn, M.; Schwarz, V.; Scobel, W.; Trelle, H. J.; Weise, E.; Wellinghausen, A.; Woller, K.; Ziegler, R.


    The EDDA experiment at the cooler synchrotron COSY measures proton-proton elastic scattering excitation functions in the momentum range 0.8 - 3.4 GeV/c. In phase 1 of the experiment, spin-averaged differential cross sections were measured continuously during acceleration with an internal polypropylene (CH2) fiber target, taking particular care to monitor luminosity as a function of beam momentum. In phase 2, excitation functions of the analyzing power AN and the polarization correlation parameters ANN, ASS and ASL are measured using a polarized proton beam and a polarized atomic hydrogen beam target. The paper presents recent dσ/dΩ and AN data. The results provide excitation functions and angular distributions of high precision and internal consistency. No evidence for narrow structures was found. The data are compared to recent phase shift solutions.

  16. Proton-proton elastic scattering excitation functions at intermediate energies: Cross sections and analyzing powers

    CERN Document Server

    Hinterberger, F; Altmeier, M; Bauer, F; Bisplinghoff, J; Büsser, K; Busch, M; Colberg, T; Diehl, O; Dohrmann, F; Engelhardt, H P; Eversheim, P D; Felden, O; Gebel, R; Glende, M; Greiff, J; Gross-Hardt, R; Hinterberger, F; Jahn, R; Jonas, E; Krause, H; Langkau, R; Lindemann, T; Lindlein, J; Maier, R; Maschuw, R; Mayer-Kuckuk, T; Meinerzhagen, A; Naehle, O; Prasuhn, D; Rohdjess, H; Rosendaal, D; Von Rossen, P; Schirm, N; Schulz-Rojahn, M; Schwarz, V; Scobel, W; Trelle, H J; Weise, E; Wellinghausen, A; Woller, K; Ziegler, R


    The EDDA experiment at the cooler synchrotron COSY measures proton-proton elastic scattering excitation functions in the momentum range 0.8 - 3.4 GeV/c. In phase 1 of the experiment, spin-averaged differential cross sections were measured continuously during acceleration with an internal polypropylene (CH sub 2) fiber target, taking particular care to monitor luminosity as a function of beam momentum. In phase 2, excitation functions of the analyzing power A sub N and the polarization correlation parameters A sub N sub N , A sub S sub S and A sub S sub L are measured using a polarized proton beam and a polarized atomic hydrogen beam target. The paper presents recent d sigma/d OMEGA and A sub N data. The results provide excitation functions and angular distributions of high precision and internal consistency. No evidence for narrow structures was found. The data are compared to recent phase shift solutions.


    Directory of Open Access Journals (Sweden)

    Ernesto Cárdenas


    Full Text Available Theoretically, polarization is associated with a higher probability of social conflict. This paper, in a microeconomic model based on the theory of social networks, analyses how changes in the network's structure affect the level of some basic parameters associated with the concept of polarization. This study shows that under upward monotonic preferences, longer sets of affiliations for each individual reduce polarization, whereas under downward monotonic preferences, longer sets of the so-called bad affiliations increase polarization. Finally, in the case of a non-monotonic system of preferences, an expansion of the affiliations set will alter the resulting polarization order in different ways depending on the preferences themselves

  18. Climate Change, Polar Bears and their management


    Derenchenko, Liza


    This is a literature study of polar bears in the context of climate change: what kind of creatures are polar bears, what are the main interpretations of current climate change, how might the polar bear adapt to these changes (feeding strategies) and how are the bears being managed (hunting)? These are relevant questions , since climate change is on the agenda, and polar bears being the apex predators of the Arctic are a key representation of the wildlife there. The third element of polar bear...

  19. Space-variant polarized Airy beam

    CERN Document Server

    Chen, Hao


    We experimentally generate an Airy beam with polarization structure while keeping its original amplitude and phase profile intact. This class of Airy beam preserves the acceleration properties. By monitoring their initial polarization structure we have provided insight concerning the self-healing mechanism of Airy beams. We investigate both theoretically and experimentally the self-healing polarization properties of the space-variant polarized Airy beams. Amplitude as well as the polarization structure tends to reform during propagation in spite of the severe truncation of the beam by finite apertures.

  20. Nonvolatile polarization control of a bistable VCSEL. (United States)

    Marconi, Mathias; Barland, Stéphane; Giudici, Massimo


    We report experimental evidence of nonvolatile all-optical memory operation using the two linear polarization states emitted from a GaAs oxide-confined VCSEL. The two polarization states coexist in a large range of pumping currents and substrate temperatures, and they can be controlled all-optically by exposing the device to polarization selective feedback, to crossed polarization reinjection orby injecting external light pulses. The active polarization state is recovered after powering off and on the VCSEL, while memory is lost if the substrate temperature is varied.

  1. Baryon spectroscopy with polarization observables from CLAS

    Energy Technology Data Exchange (ETDEWEB)

    Strauch, Steffen [Univ. of South Carolina, Columbia, SC (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)


    The spectrum of nucleon excitations is dominated by broad and overlapping resonances. Polarization observables in photoproduction reactions are key in the study of these excitations. They give indispensable constraints to partial-wave analyses and help clarify the spectrum. A series of polarized photoproduction experiments have been performed at the Thomas Jefferson National Accelerator Facility with the CEBAF Large Acceptance Spectrometer (CLAS). These measurements include data with linearly and circularly polarized tagged-photon beams, longitudinally and transversely polarized proton and deuterium targets, and recoil polarizations through the observation of the weak decay of hyperons. An overview of these studies and recent results will be given.

  2. Macrophage polarization differs between apical granulomas, radicular cysts, and dentigerous cysts. (United States)

    Weber, Manuel; Schlittenbauer, Tilo; Moebius, Patrick; Büttner-Herold, Maike; Ries, Jutta; Preidl, Raimund; Geppert, Carol-Immanuel; Neukam, Friedrich W; Wehrhan, Falk


    Apical periodontitis can appear clinically as apical granulomas or radicular cysts. There is evidence that immunologic factors are involved in the pathogenesis of both pathologies. In contrast to radicular cysts, the dentigerous cysts have a developmental origin. Macrophage polarization (M1 vs M2) is a main regulator of tissue homeostasis and differentiation. There are no studies comparing macrophage polarization in apical granulomas, radicular cysts, and dentigerous cysts. Forty-one apical granulomas, 23 radicular cysts, and 23 dentigerous cysts were analyzed in this study. A tissue microarray (TMA) of the 87 consecutive specimens was created, and CD68-, CD11c-, CD163-, and MRC1-positive macrophages were detected by immunohistochemical methods. TMAs were digitized, and the expression of macrophage markers was quantitatively assessed. Radicular cysts are characterized by M1 polarization of macrophages while apical granulomas show a significantly higher degree of M2 polarization. Dentigerous cysts have a significantly lower M1 polarization than both analyzed periapical lesions (apical granulomas and radicular cysts) and accordingly, a significantly higher M2 polarization than radicular cysts. Macrophage cell density in dentigerous cysts is significantly lower than in the periapical lesions. The development of apical periodontitis towards apical granulomas or radicular cysts might be directed by macrophage polarization. Radicular cyst formation is associated with an increased M1 polarization of infiltrating macrophages. In contrast to radicular cysts, dentigerous cysts are characterized by a low macrophage infiltration and a high degree of M2 polarization, possibly reflecting their developmental rather than inflammatory origin. As M1 polarization of macrophages is triggered by bacterial antigens, these results underline the need for sufficient bacterial clearance during endodontic treatment to prevent a possible M1 macrophage-derived stimulus for radicular cyst

  3. On the large COMPASS polarized deuteron target

    CERN Document Server

    Finger, M; Baum, G; Doshita, N; Finger, M Jr; Gautheron, F; Goertz, St; Hasegawa, T; Heckmann, J; Hess, Ch; Horikawa, N; Ishimoto, S; Iwata, T; Kisselev, Y; Koivuniemi, J; Kondo, K; Le Goff, J-M; Magnon, A; Marchand, C; Matsuda, T; Meyer, W; Reicherz, G; Srnka, A


    The spin structure of the nucleons is investigated in deep inelastic scattering of a polarized muon beam and a polarized nucleon target in the COMPASS experiment at CERN since 2001. To achieve high luminosities a large solid polarized target is used. The COMPASS polarized target consists of a high cooling power $^{3}$He/$^{4}$He dilution refrigerator capable to maintain working temperature of the target material at about 50mK, a superconducting solenoid and dipole magnet system for longitudinal and transversal magnetic field on the target material, respectively, target cells containing polarizable material, microwave cavities and high power microwave radiation systems for dynamic nuclear polarization and the nuclear magnetic resonance system for nuclear spin polarization measurements. During 2001–2004 experiments superconducting magnet system with opening angle $\\pm$69 mrad, polarized target holder with two target cells and corresponding microwave and NMR systems have been used. For the data taking from 200...

  4. Electrical spectrum & network analyzers a practical approach

    CERN Document Server

    Helfrick, Albert D


    This book presents fundamentals and the latest techniques of electrical spectrum analysis. It focuses on instruments and techniques used on spectrum and network analysis, rather than theory. The book covers the use of spectrum analyzers, tracking generators, and network analyzers. Filled with practical examples, the book presents techniques that are widely used in signal processing and communications applications, yet are difficult to find in most literature.Key Features* Presents numerous practical examples, including actual spectrum analyzer circuits* Instruction on how to us

  5. ADAM: Analyzer for Dialectal Arabic Morphology

    Directory of Open Access Journals (Sweden)

    Wael Salloum


    Full Text Available While Modern Standard Arabic (MSA has many resources, Arabic Dialects, the primarily spoken local varieties of Arabic, are quite impoverished in this regard. In this article, we present ADAM (Analyzer for Dialectal Arabic Morphology. ADAM is a poor man’s solution to quickly develop morphological analyzers for dialectal Arabic. ADAM has roughly half the out-of-vocabulary rate of a state-of-the-art MSA analyzer and is comparable in its recall performance to an Egyptian dialectal morphological analyzer that took years and expensive resources to build.

  6. Temporal Trends and Future Predictions of Mercury Concentrations in Northwest Greenland Polar Bear (Ursus maritimus) Hair

    DEFF Research Database (Denmark)

    Dietz, Rune; Born, E.W.; Riget, Frank Farsø


    Hair samples from 117 Northwest Greenland polar bears (Ursus maritimus) were taken during 1892-2008 and analyzed for total mercury (hereafterHg). The sample represented 28 independent years and the aim of the study was to analyze for temporal Hg trends. Mercury concentrations showed yearly...... significant increases of 1.6-1.7% (p polar bear......-2008 concentrations ofHg in Northwest Greenland polar bear hair exceeded the general guideline values of 20-30 μg/g dry weight for terrestrial wildlife, whereas the neurochemical effect level of 5.4 μg Hg/g dry weight proposed for East Greenland polar bears was exceeded in 93.5% of the cases. These results call...

  7. Polarized light imaging of birefringence and diattenuation at highresolution and high sensitivity

    CERN Document Server

    Mehta, Shalin B; Oldenbourg, Rudolf


    Polarized light microscopy provides unique opportunities for analyzing the molecular order in man-made and natural materials, including biological structures inside living cells, tissues, and whole organisms. 20 years ago, the LC-PolScope was introduced as a modern version of the traditional polarizing microscope enhanced by liquid crystal devices for the control of polarization, and by electronic imaging and digital image processing for fast and comprehensive image acquisition and analysis. The LC- PolScope is commonly used for birefringence imaging, analyzing the spatial and temporal variations of the differential phase delay in ordered and transparent materials. Here we describe an alternative use of the LC-PolScope for imaging the polarization dependent transmittance of dichroic materials. We explain the minor changes needed to convert the instrument between the two imaging modes, discuss the relationship between the quantities measured with either instrument, and touch on the physical connection between ...

  8. Schottky contact formation on polar and non-polar AlN

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Pramod; Bryan, Isaac; Bryan, Zachary; Tweedie, James; Kirste, Ronny; Collazo, Ramon; Sitar, Zlatko [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695-7919 (United States)


    The interfaces of m- and c-plane AlN with metals of different work functions and electro-negativities were characterized and the Schottky barrier heights were measured. The Schottky barrier height was determined by measuring the valence band maximum (VBM) with respect to the Fermi level at the surface (interface) before (after) metallization. VBM determination included accurate modeling and curve fitting of density of states at the valence band edge with the XPS data. The experimental behavior of the barrier heights could not be explained by the Schottky-Mott model and was modeled using InterFace-Induced Gap States (IFIGS). A slope parameter (S{sub X}) was used to incorporate the density of surface states and is a measure of Fermi level pinning. The experimental barriers followed theoretical predictions with a barrier height at the surface Fermi level (Charge neutrality level (CNL)) of ∼2.1 eV (∼2.7 eV) on m-plane (c-plane) and S{sub X} ∼ 0.36 eV/Miedema unit. Slope parameter much lower than 0.86 implied a surface/interface states dominated behavior with significant Fermi level pinning and the measured barrier heights were close to the CNL. Titanium and zirconium provided the lowest barriers (1.6 eV) with gold providing the highest (2.3 eV) among the metals analyzed on m-plane. It was consistently found that barrier heights decreased from metal polar to non-polar surfaces, in general, due to an increasing CNL. The data indicated that charged IFIGS compensate spontaneous polarization charge. These barrier height and slope parameter measurements provided essential information for designing Schottky diodes and other contact-based devices on AlN.

  9. Analysis of method of polarization surveying of water surface oil pollution (United States)

    Zhukov, B. S.


    A method of polarization surveying of oil films on the water surface is analyzed. Model calculations of contrasted oil and water obtained with different orientations of the analyzer are discussed. The model depends on the spectral range, water transparency and oil film, and the selection of observational direction.

  10. Cloud morphology and dynamics in Saturn's northern polar region (United States)

    Antuñano, Arrate; del Río-Gaztelurrutia, Teresa; Sánchez-Lavega, Agustín; Rodríguez-Aseguinolaza, Javier


    We present a study of the cloud morphology and motions in the north polar region of Saturn, from latitude ∼ 70°N to the pole based on Cassini ISS images obtained between January 2009 and November 2014. This region shows a variety of dynamical structures: the permanent hexagon wave and its intense eastward jet, a large field of permanent ;puffy; clouds with scales from 10 - 500 km, probably of convective origin, local cyclone and anticyclones vortices with sizes of ∼1,000 km embedded in this field, and finally the intense cyclonic polar vortex. We report changes in the albedo of the clouds that delineate rings of circulation around the polar vortex and the presence of ;plume-like; activity in the hexagon jet, in both cases not accompanied with significant variations in the corresponding jets. No meridional migration is observed in the clouds forming and merging in the field of puffy clouds, suggesting that their mergers do not contribute to the maintenance of the polar vortex. Finally, we analyze the dominant growing modes for barotropic and baroclinic instabilities in the hexagon jet, showing that a mode 6 barotropic instability is dominant at the latitude of the hexagon.

  11. Transversely polarized Drell-Yan asymmetry AT T at NLO (United States)

    de Florian, Daniel


    We present the first fully differential next-to-leading order QCD calculation for lepton production in transversely polarized hadronic collisions, p ↑p ↑→ℓ±X , where the lepton arises from the decay of an electroweak gauge boson. The calculation is implemented in the Monte-Carlo like code che that already includes the unpolarized and longitudinally polarized cross sections and may be readily used to perform a comparison to experimental data and to extract information on the related parton distributions. We analyze the perturbative stability of the cross-section and double spin asymmetry AT T at RHIC kinematics. We find that the QCD corrections are non-negligible even at the level of asymmetries and that they strongly depend on the lepton kinematics. Furthermore, we present two scenarios for transversely polarized parton distributions, based on the de Florian-Sassot-Stratmann-Vogelsang (DSSV) set of longitudinally parton densities and fully evolved to NLO accuracy, that can be used for the evaluation of different observables involving transverse polarization.

  12. Analysis of polarized pulse propagation through one-dimensional scattering medium (United States)

    Zhang, Yong; Yao, Feng-Ju; Xie, Ming; Yi, Hong-Liang


    This paper analyzes the polarized light propagation in a one-dimensional scattering medium with the upper surface subjected to an oblique incident short-pulsed laser beam using the natural element method (NEM). The NEM discretization scheme for the transient vector radiative transfer equation (TVRTE) is presented in detail. The accuracy of the natural element method for transient vector radiative transfer in the scattering medium is assessed. Numerical results show that the NEM is accurate, and effective in solving transient polarized radiative problems. We examine a square short-pulsed laser transport firstly in the atmosphere with Mie scattering and then within aerosol scattering medium. We then investigate the transient polarized radiative transfer problem in the atmosphere-ocean system. The time-resolved signals and the polarization state of the Stokes vector are presented and analyzed. It is found that the scattering types of the medium make greatly influence on the transient transportation of the polarized light. Critically, the polarization states of the backward and forward scattered photons show significantly different time varying trends. For the two-layer system with dissimilar refractive index distributions, due to the total-reflection effect, the existence of a Fresnel interface significantly changes the polarization state of the light, and discontinuous distribution features are observed on the interface.

  13. Scale-selective analysis of myocardium polarization images in problems of diagnostic of necrotic changes (United States)

    Ushenko, O. G.; Dubolazov, O. V.; Ushenko, Yu. O.; Gorsky, M. P.


    This research presents the results of investigation of laser polarization fluorescence of biological layers (histological sections of the myocardium). The polarized structure of autofluorescence imaging layers of biological tissues was detected and investigated. Proposed the model of describing the formation of polarization inhomogeneous of autofluorescence imaging biological optically anisotropic layers. On this basis, analytically and experimentally tested to justify the method of laser polarimetry autofluorescent. Analyzed the effectiveness of of this method in the postmortem diagnosis of infarction. The objective criteria (statistical moments) of differentiation of autofluorescent images of histological sections myocardium were defined. The operational characteristics (sensitivity, specificity, accuracy) of these technique were determined.

  14. Interactions of space-variant polarization beams with Zeeman-shifted rubidium vapor

    CERN Document Server

    Szapiro, Anat; Levy, Uriel


    Space variant beams are of great importance as a variety of applications have emerged in recent years. As such, manipulation of their degrees of freedom is highly desired. Here, by exploiting the circular dichroism and circular birefringence in a Zeeman-shifted Rb medium, we study the general interaction of space variant beams with such a medium. We present two particular cases of radial polarization and hybrid polarization beams where the control of the polarization states is demonstrated experimentally. Moreover, we show that a Zeeman-shifted atomic system can be used as an analyzer for such space variant beams

  15. Population Genomics Reveal Recent Speciation and Rapid Evolutionary Adaptation in Polar Bears


    Liu, Shiping; Lorenzen, Eline D.; Fumagalli, Matteo; Li, Bo; Harris, Kelley; Xiong, Zijun; ZHOU, Long; Korneliussen, Thorfinn Sand; Somel, Mehmet; Babbitt, Courtney; Wray, Greg; Li, Jianwen; He, Weiming; Wang, Zhuo; Fu, Wenjing


    Polar bears are uniquely adapted to life in the High Arctic and have undergone drastic physiological changes in response to Arctic climates and a hyperlipid diet of primarily marine mammal prey. We analyzed 89 complete genomes of polar bear and brown bear using population genomic modeling and show that the species diverged only 479–343 thousand years BP. We find that genes on the polar bear lineage have been under stronger positive selection than in brown bears; nine of the top 16 genes under...

  16. SERS polarization dependence of Ag nanorice dimer on metal and dielectric film (United States)

    Zang, Yuying; Shi, Haiyang; Huang, Yingzhou; Zeng, Xiping; Pan, Liang; Wang, Shuxia; Wen, Weijia


    The polarization dependence plays a great impact on the SERS intensities for the surface plasmon coupling between nanoparticle aggregating. In this work, the SERS intensities collected from nanorice heterogeneous dimer or homogeneous dimer on Au, ITO and glass substrates exhibit strong polarization dependence. This result is further analyzed by the simulated surface charge distribution and electromagnetic enhancement distribution. Our data illustrate that SERS polarization dependence exhibits in all gaps in whole system, not only the gaps between nanorices but also gaps between nanorices and film, which could be important for the application of SERS as an ultrasensitive sensing technique.

  17. Scaling laws and sum rules for the B-mode polarization

    CERN Document Server

    Giovannini, Massimo


    The formation of the microwave background polarization anisotropies is investigated when the stochastic Faraday rate is stationary, random and Markovian. The scaling properties of the polarization power spectra and of their nonlinear combinations are scrutinized as a function of the comoving frequency. It is argued that each frequency channel of a given experiment measuring simultaneously the E-mode and the B-mode spectra can be analyzed in this framework with the aim of testing the physical origin of the polarization in a model-independent perspective.

  18. Next-to-Leading order approximation of polarized valon and parton distributions

    Energy Technology Data Exchange (ETDEWEB)

    Khorramian, Ali N. [Physics Department, Semnan University, Semnan (Iran, Islamic Republic of) and Institute for Studies in Theoretical Physics and Mathematics (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Repubilc of)]. E-mail:; Mirjalili, Abolfazl [Physics Department, Yazd University, Yazd (Iran, Islamic Republic of); Institute for Studies in Theoretical Physics and Mathematics (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Tehrani, S. Atashbar [Physics Department, Persian Gulf University, Boushehr (Iran, Islamic Republic of)


    Polarized parton distributions and structure functions of the nucleon are analyzed in the improved valon model. The valon representation provides a model to represent hadrons in terms of quarks, providing a unified description of bound state and scattering properties of hadrons. Polarized valon distributions are seen to play an important role in describing the spin dependence of parton distributions in the leading order (LO) and next-to-leading order (NLO) approximations. In the polarized case, a convolution integral is derived in the framework of the valon model. The Polarized valon distribution in a proton and the polarized parton distributions inside the valon are necessary to obtain the polarized parton distributions in a proton. Bernstein polynomial averages are used to extract the unknown parameters of the polarized valon distributions by fitting to the available experimental data. The predictions for the NLO calculations of the polarized parton distributions and proton structure functions are compared with the LO approximation. It is shown that the results of the calculations for the proton structure function, xg{sub 1}{sup p}, and its first moment, {gamma}{sub 1}{sup p}, are in good agreement with the experimental data for a range of values of Q{sup 2}. Finally the spin contribution of the valons to the proton is calculated. (author)

  19. Nonnormal operators in physics, a singular-vectors approach: illustration in polarization optics. (United States)

    Tudor, Tiberiu


    The singular-vectors analysis of a general nonnormal operator defined on a finite-dimensional complex vector space is given in the frame of a pure operatorial ("nonmatrix," "coordinate-free") approach, performed in a Dirac language. The general results are applied in the field of polarization optics, where the nonnormal operators are widespread as operators of various polarization devices. Two nonnormal polarization devices representative for the class of nonnormal and even pathological operators-the standard two-layer elliptical ideal polarizer (singular operator) and the three-layer ambidextrous ideal polarizer (singular and defective operator)-are analyzed in detail. It is pointed out that the unitary polar component of the operator exists and preserves, in such pathological case too, its role of converting the input singular basis of the operator in its output singular basis. It is shown that for any nonnormal ideal polarizer a complementary one exists, so that the tandem of their operators uniquely determines their (common) unitary polar component.

  20. The Polarization Orientation Shift Estimation and Compensation of PolSAR Data in Forest Area (United States)

    Zhao, Lei; Chen, Erxue; Li, Zengyuan; Li, Lan; Gu, Xinzhi


    Polarization orientation angle (POA) is a major parameter of electromagnetic wave. This angle will be shift due to azimuth slopes, which will affect the radiometric quality of PolSAR data. Under the assumption of reflection symmetrical medium, the shift value of polarization orientation angle (POAs) can be estimated by Circular Polarization Method (CPM). Then, the shift angle can be used to compensate PolSAR data or extract DEM information. However, it is less effective when using high-frequency SAR (L-, C-band) in the forest area. The main reason is that the polarization orientation angle shift of forest area not only influenced by topography, but also affected by the forest canopy. Among them, the influence of the former belongs to the interference information should be removed, but the impact of the latter belongs to the polarization feature information needs to be retained. The ALOS2 PALSAR2 L-band full polarimetric SAR data was used in this study. Base on the Circular Polarization and DEM-based method, we analyzed the variation of shift value of polarization orientation angle and developed the polarization orientation shift estimation and compensation of PolSAR data in forest.

  1. Development of a polarized neutron beam line at Algerian research reactors using McStas software

    Energy Technology Data Exchange (ETDEWEB)

    Makhloufi, M., E-mail: [Centre de Recherche Nucléaire de Birine (Algeria); Salah, H. [Centre de Recherche Nucléaire d' Alger (Algeria)


    Unpolarized instrumentation has long been studied and designed using McStas simulation tool. But, only recently new models were developed for McStas to simulate polarized neutron scattering instruments. In the present contribution, we used McStas software to design a polarized neutron beam line, taking advantage of the available spectrometers reflectometer and diffractometer in Algeria. Both thermal and cold neutron was considered. The polarization was made by two types of supermirrors polarizers FeSi and CoCu provided by the HZB institute. For sake of performance and comparison, the polarizers were characterized and their characteristics reproduced. The simulated instruments are reported. Flipper and electromagnets for guide field are developed. Further developments including analyzers and upgrading of the existing spectrometers are underway. - Highlights: • Permit to evaluate the feasibility of a polarized neutron scattering instrument prior to its implementation. • Help to understand the origin of instrumental imperfections and offer an optimized set up configuration. • Provide the possibility to use the FeSi and CoCu supermirrors, designed to polarize spin up cold neutron, to polarize thermal neutron.

  2. Phacoemulsification in posterior polar cataract

    Directory of Open Access Journals (Sweden)

    Servet Cetinkaya

    Full Text Available ABSTRACT Purpose: To evaluate the results and complications of phacoemulsification surgery in eyes with posterior polar cataracts and compare the techniques of viscodissection and hydrodissection. Methods: The medical records of 29 consecutive patients (16 males, 13 females with posterior polar cataracts (44 eyes who had undergone cataract surgery were retrospectively reviewed. Patients were divided into two groups according to the technique used; viscodissection was applied to the experimental group (group 1 and hydrodissection to the control group (group 2. Results: The postoperative best corrected visual acuity (BCVA was 0.19 ± 0.22 logMAR (mean ± standard deviation (range 0.00-0.70 in group 1 and 0.25 ± 0.18 logMAR (range 0.00-0.70 in group 2. Although the mean postoperative BCVA in group 1 was greater than that in group 2, the difference was not statistically significant (p=0.165. The mean postoperative BCVA was significantly greater than the mean preoperative BCVA in both groups (p=0.00. Intraoperatively, posterior capsular rupture occurred during the removal of the cortex in three eyes (13% of group 1 patients, with vitreous loss and anterior vitrectomy in one eye only. In group 2, six eyes (28.5% presented posterior capsular rupture, and anterior vitrectomy was performed because of vitreous loss in three eyes. Although the percentage of posterior capsular rupture was greater in group 2, the difference was not statistically significant (p=0.207. Conclusions: Complications in posterior polar cataract surgeries can be overcome by being careful throughout the surgery and using proper techniques. Viscodissection may be better for avoiding posterior capsular rupture than hydrodissection.

  3. Twist-3 effects for polarized virtual photon structure function g2γ (United States)

    Sasaki, K.


    We investigate twist-3 effects in the polarized virtual photon. The structure function g2γ, which exists only for the virtual photon target and can be measured in future polarized e+e- collider experiments, receives both twist-2 and twist-3 contributions. The twist-3 part is analyzed in pure QED interaction as well as in LO QCD. We find the twist-3 contribution is appreciable for the photon in contrast to the nucleon case.

  4. Influence of light polarization on the dynamics of optically pumped lasers

    Energy Technology Data Exchange (ETDEWEB)

    Arjona, M.; Corbalan, R. (Departament de Fisica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain)); Laguarta, F.; Pujol, J. (Departament d' Optica i Optometria, Universitat Politecnica de Catalunya, 08222 Terrassa (Spain)); Vilaseca, R. (Departament I. D' Optica, Universitat de Valencia, 46100 Burjassot (Spain))


    The dynamic behavior of a coherently pumped ring laser with a homogeneously broadened four-level medium is analyzed theoretically, considering linearly polarized pump and generated laser beams. The laser is shown to be much more stable when these polarizations are parallel than when they are orthogonal. In the latter case the instability pump threshold can be as low as four times the first laser threshold, and the laser dynamics shows Lorenz-type features.

  5. Analyzing Information in Complex Collaborative Tasks

    NARCIS (Netherlands)

    Zaad, Lambert; Dick Lenior; Els van der Pool; Thea van der Geest


    In this article, we present a method for analyzing the communication of people who exchange dynamic and complex information to come to a shared understanding of situations and of the actions planned and monitored by one party, but executed remotely by another. To examine this situation, we analyzed

  6. How to Analyze Paired Comparison Data (United States)


    How to Analyze Paired Comparison Data Kristi Tsukida and Maya R. Gupta Department of Electrical Engineering University of Washington Seattle, WA...REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE How to Analyze Paired Comparison Data 5a. CONTRACT NUMBER 5b. GRANT

  7. Higher education, wages, and polarization


    Robert G. Valletta


    The earnings gap between people with a college degree and those with no education beyond high school has been growing since the late 1970s. Since 2000, however, the gap has grown more for those who have earned a post-graduate degree as well. The divergence between workers with college degrees and those with graduate degrees may be one manifestation of rising labor market polarization, which benefits those earning the highest and the lowest wages relatively more than those in the middle of the...

  8. Polarization insensitive terahertz metamaterial absorber. (United States)

    Grant, J; Ma, Y; Saha, S; Lok, L B; Khalid, A; Cumming, D R S


    We present the simulation, implementation, and measurement of a polarization insensitive resonant metamaterial absorber in the terahertz region. The device consists of a metal/dielectric-spacer/metal structure allowing us to maximize absorption by varying the dielectric material and thickness and, hence, the effective electrical permittivity and magnetic permeability. Experimental absorption of 77% and 65% at 2.12 THz (in the operating frequency range of terahertz quantum cascade lasers) is observed for a spacer of polyimide or silicon dioxide respectively. These metamaterials are promising candidates as absorbing elements for thermally based terahertz imaging.

  9. A remark on polar noncommutativity

    Directory of Open Access Journals (Sweden)

    Andrew Iskauskas


    Full Text Available Noncommutative space has been found to be of use in a number of different contexts. In particular, one may use noncommutative spacetime to generate quantised gravity theories. Via an identification between the Moyal ⋆-product on function space and commutators on a Hilbert space, one may use the Seiberg–Witten map to generate corrections to such gravity theories. However, care must be taken with the derivation of commutation relations. We examine conditions for the validity of such an approach, and motivate the correct form for polar noncommutativity in R2. Such an approach lends itself readily to extension to more complicated spacetime parametrisations.

  10. Optimization of polarizer azimuth in improving domain image contrast in magneto-optical Kerr microscope

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X. [School of Physics and Technology, University of Ji Nan, Jinan 250022 (China); Lian, J., E-mail: [Department of Optical Engineering, Scholl of Science and Engineering, Shan Dong University, Jinan 250100 (China); Li, P.; Li, X [School of Physics and Technology, University of Ji Nan, Jinan 250022 (China); Li, M.M.; Wang, Y.; Liu, Y.X. [Department of Optical Engineering, Scholl of Science and Engineering, Shan Dong University, Jinan 250100 (China)


    The magneto-optical Kerr effect (MOKE) is a widely used technique in magnetic domain imaging for its high surface sensitivity and external magnetic compatibility. In this work, we use the generalized magneto-optical ellipsometry technique to study the influence of polarizer and analyzer azimuth on domain image contrast in the Kerr microscope. Results show that the image contrasts around the extinction place are larger than other area. When the polarizer and analyzer are set slightly deviated from the extinction condition (0.35°,89.7°), the maximum image contrast can be obtained. The color map of image contrast on polarizer and analyzer angle is given by measuring the MOKE response of 200 nm permalloy. Results verify the validity of the conclusion. - Highlights: • In this text, we expand the application of generalized magneto-optical ellipsometry (GME) to domain observing area. We study the domain image contrast with different polarizer and analyzer combination with GME. • 1. In this text, we provide a new method to improve the domain image contrast by optimizing the polarizer and analyzer azimuth combinations in magneto-optical Kerr microscopy.

  11. Polar Embedding for Aurora Image Retrieval. (United States)

    Yang, Xi; Gao, Xinbo; Tian, Qi


    Exploring the multimedia techniques to assist scientists for their research is an interesting and meaningful topic. In this paper, we focus on the large-scale aurora image retrieval by leveraging the bag-of-visual words (BoVW) framework. To refine the unsuitable representation and improve the retrieval performance, the BoVW model is modified by embedding the polar information. The superiority of the proposed polar embedding method lies in two aspects. On the one hand, the polar meshing scheme is conducted to determine the interest points, which is more suitable for images captured by circular fisheye lens. Especially for the aurora image, the extracted polar scale-invariant feature transform (polar-SIFT) feature can also reflect the geomagnetic longitude and latitude, and thus facilitates the further data analysis. On the other hand, a binary polar deep local binary pattern (polar-DLBP) descriptor is proposed to enhance the discriminative power of visual words. Together with the 64-bit polar-SIFT code obtained via Hamming embedding, the multifeature index is performed to reduce the impact of false positive matches. Extensive experiments are conducted on the large-scale aurora image data set. The experimental result indicates that the proposed method improves the retrieval accuracy significantly with acceptable efficiency and memory cost. In addition, the effectiveness of the polar-SIFT scheme and polar-DLBP integration are separately demonstrated.

  12. Measurement of polarization observables of the associated strangeness production in proton proton interactions

    Energy Technology Data Exchange (ETDEWEB)

    Hauenstein, F.; Klaja, P. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen (Germany); Borodina, E.; Dzhygadlo, R.; Gast, W.; Gillitzer, A.; Grzonka, D.; Kilian, K.; Mertens, M.; Roderburg, E.; Roeder, M.; Sefzick, T.; Wintz, P. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Clement, H.; Doroshkevich, E.; Ehrhardt, K. [Physikalisches Institut der Universitaet Tuebingen, Tuebingen (Germany); University of Tuebingen, Kepler Center for Astro and Particle Physics, Tuebingen (Germany); Eyrich, W.; Kober, L.; Krapp, M. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen (Germany); Jowzaee, S. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Jagellonian University, Institute of Physics, Cracow (Poland); Moskal, P.; Smyrski, J. [Jagellonian University, Institute of Physics, Cracow (Poland); Ritman, J. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Juelich Aachen Research Alliance, Forces and Matter Experiments (JARA-FAME), Forschungszentrum Juelich, Juelich (Germany); RWTH Aachen, Aachen (Germany); Ruhr-Universitaet Bochum, Experimentalphysik I, Bochum (Germany); Schroeder, W. [Forschungszentrum Juelich, Corporate Development, Juelich (Germany); Wuestner, P. [Zentralinstitut fuer Engineering, Elektronik und Analytik, Juelich (Germany); Collaboration: The COSY-TOF Collaboration


    The Λ polarization, the analyzing power, and the Λ spin transfer coefficient of the reaction pp → pK{sup +} Λ were measured at beam momenta of 2.70 GeV/c and 2.95 GeV/c corresponding to excess energies of 122 MeV and 204 MeV. While the analyzing power and the spin transfer coefficient do not change significantly with the excess energy, the Λ polarization varies strongly and changes its sign. As this is the first measurement of polarization observables below an excess energy of 200 MeV, the change of the sign of the Λ polarization was not observed before. The high statistics of the data (∼ 200 k events for each momentum) enables detailed studies of the dependence of the Λ polarization and the analyzing power on the center-of-mass momentum of the particles. The results of the spin transfer coefficient are in qualitative agreement with the DISTO experiment. The Λ polarization data of 2.95 GeV/c are only conform with the DISTO experiment, while both the 2.70 GeV/c and 2.95 GeV/c data differ strongly from all previous measurements, whether exclusive or inclusive. (orig.)

  13. The Polar Rock Repository: Rescuing Polar Collections for New Research (United States)

    Grunow, A.


    Geological field expeditions in polar regions are logistically difficult, financially expensive and can have a significant environmental impact on pristine regions. The scarcity of outcrop in Antarctica (98% ice-covered) makes previously collected rock samples very valuable to the science community. NSF recognized the need for preserving rock, dredge, and terrestrial core samples from polar areas and created the Polar Rock Repository (PRR). The PRR collection allows for full and open access to both samples and metadata via the PRR website. In addition to the physical samples and their basic metadata, the PRR archives supporting materials from the collector, field notebooks, images of the samples, field maps, air photos, thin sections and any associated bibliography/DOI's. Many of these supporting materials are unique. More than 40,000 samples are available from the PRR for scientific analysis to researchers around the globe. Most of the samples cataloged at the PRR were collected more than 30 years ago, some more than 100 years ago. The rock samples and metadata are made available online through an advanced search engine for the PRR website. This allows scientists to "drill down" into search results using categories and look-up object fields similar to websites like Amazon. Results can be viewed in a table, downloaded as a spreadsheet, or plotted on an interactive map that supports display of satellite imagery and bathymetry layers. Samples can be requested by placing them in the `shopping cart'. These old sample collections have been repeatedly used by scientists from around the world. One data request involved locating coal deposits in Antarctica for a global compilation and another for looking at the redox state of batholithic rocks from the Antarctic Peninsula using magnetic susceptibilities of PRR rocks. Sample usage has also included non-traditional geologic studies, such as a search for monopoles in Cenozoic volcanic samples, and remote sensing

  14. Polarized lepton-nucleon scattering

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, E. [Stanford Univ., CA (United States)


    The author provides a summary of the proposed and published statistical (systematic) uncertainties from the world experiments on nucleon spin structure function integrals. By the time these programs are complete, there will be a vast resource of data on nucleon spin structure functions. Each program has quite different experimental approaches regarding the beams, targets, and spectrometers thus ensuring systematically independent tests of the spin structure function measurements. Since the field of spin structure function measurements began, there has been a result appearing approximately every five years. With advances in polarized target technology and high polarization in virtually all of the lepton beams, results are now coming out each year; this is a true signature of the growth in the field. Hopefully, the experiments will provide a consistent picture of nucleon spin structure at their completion. In summary, there are still many open questions regarding the internal spin structure of the nucleon. Tests of QCD via the investigation of the Bjorken sum rule is a prime motivator for the field, and will continue with the next round of precision experiments. The question of the origin of spin is still a fundamental problem. Researchers hope is that high-energy probes using spin will shed light on this intriguing mystery, in addition to characterizing the spin structure of the nucleon.

  15. IGS polar motion measurement accuracy

    Directory of Open Access Journals (Sweden)

    Jim Ray


    Full Text Available We elaborate an error budget for the long-term accuracy of IGS (International Global Navigation Satellite System Service polar motion estimates, concluding that it is probably about 25–30 μas (1-sigma overall, although it is not possible to quantify possible contributions (mainly annual that might transfer directly from aliases of subdaily rotational tide errors. The leading sources are biases arising from the need to align daily, observed terrestrial frames, within which the pole coordinates are expressed and which are continuously deforming, to the secular, linear international reference frame. Such biases are largest over spans longer than about a year. Thanks to the very large number of IGS tracking stations, the formal covariance errors are much smaller, around 5 to 10 μas. Large networks also permit the systematic frame-related errors to be more effectively minimized but not eliminated. A number of periodic errors probably also influence polar motion results, mainly at annual, GPS (Global Positioning System draconitic, and fortnightly periods, but their impact on the overall error budget is unlikely to be significant except possibly for annual tidal aliases. Nevertheless, caution should be exercised in interpreting geophysical excitations near any of the suspect periods.

  16. Myxobacteria, polarity, and multicellular morphogenesis. (United States)

    Kaiser, Dale; Robinson, Mark; Kroos, Lee


    Myxobacteria are renowned for the ability to sporulate within fruiting bodies whose shapes are species-specific. The capacity to build those multicellular structures arises from the ability of M. xanthus to organize high cell-density swarms, in which the cells tend to be aligned with each other while constantly in motion. The intrinsic polarity of rod-shaped cells lays the foundation, and each cell uses two polar engines for gliding on surfaces. It sprouts retractile type IV pili from the leading cell pole and secretes capsular polysaccharide through nozzles from the trailing pole. Regularly periodic reversal of the gliding direction was found to be required for swarming. Those reversals are generated by a G-protein switch which is driven by a sharply tuned oscillator. Starvation induces fruiting body development, and systematic reductions in the reversal frequency are necessary for the cells to aggregate rather than continue to swarm. Developmental gene expression is regulated by a network that is connected to the suppression of reversals.

  17. Optical polarization: background and camouflage (United States)

    Škerlind, Christina; Hallberg, Tomas; Eriksson, Johan; Kariis, Hans; Bergström, David


    Polarimetric imaging sensors in the electro-optical region, already military and commercially available in both the visual and infrared, show enhanced capabilities for advanced target detection and recognition. The capabilities arise due to the ability to discriminate between man-made and natural background surfaces using the polarization information of light. In the development of materials for signature management in the visible and infrared wavelength regions, different criteria need to be met to fulfil the requirements for a good camouflage against modern sensors. In conventional camouflage design, the aimed design of the surface properties of an object is to spectrally match or adapt it to a background and thereby minimizing the contrast given by a specific threat sensor. Examples will be shown from measurements of some relevant materials and how they in different ways affect the polarimetric signature. Dimensioning properties relevant in an optical camouflage from a polarimetric perspective, such as degree of polarization, the viewing or incident angle, and amount of diffuse reflection, mainly in the infrared region, will be discussed.

  18. Applying the polarization memory effect in polarization-gated subsurface imaging. (United States)

    Nothdurft, Ralph; Yao, Gang


    Polarization memory is a well established phenomenon occurring when circularly polarized light propagates in turbid media of larger particles. Recent studies have demonstrated that the circularly cross-polarized imaging can significantly improve subsurface reflection contrast due to the polarization memory effect. We have found that such improvement is strongly influenced by the optical properties of the media. Circularly cross-polarized light provides superior image enhancement in low scattering media, but becomes inferior in high scattering media. Our experiments also demonstrate that polarization imaging provides no significant improvement to image resolution.

  19. The recoil proton polarization in. pi. p elastic scattering

    Energy Technology Data Exchange (ETDEWEB)

    Seftor, C.J.


    The polarization of the recoil proton for ..pi../sup +/p and ..pi../sup -/p elastic scattering has been measured for various angles at 547 MeV/c and 625 MeV/c by a collaboration involving The George Washington University; the University of California, Los Angeles; and Abilene Christian University. The experiment was performed at the P/sup 3/ East experimental area of the Los Alamos Meson Physics Facility. Beam intensities varied from 0.4 to 1.0 x 10/sup 7/ ..pi../sup -/'s/sec and from 3.0 to 10.0 x 10/sup 7/ ..pi../sup +/'s/sec. The beam spot size at the target was 1 cm in the horizontal direction by 2.5 cm in the vertical direction. A liquid-hydrogen target was used in a flask 5.7 cm in diameter and 10 cm high. The scattered pion and recoil proton were detected in coincidence using the Large Acceptance Spectrometer (LAS) to detect and momentum analyze the pions and the JANUS recoil proton polarimeter to detect and measure the polarization of the protons. Results from this experiment are compared with previous measurements of the polarization, with analyzing power data previously taken by this group, and to partial-wave analysis predictions. 12 refs., 53 figs., 18 tabs.

  20. Systems Analyze Water Quality in Real Time (United States)


    A water analyzer developed under Small Business Innovation Research (SBIR) contracts with Kennedy Space Center now monitors treatment processes at water and wastewater facilities around the world. Originally designed to provide real-time detection of nutrient levels in hydroponic solutions for growing plants in space, the ChemScan analyzer, produced by ASA Analytics Inc., of Waukesha, Wisconsin, utilizes spectrometry and chemometric algorithms to automatically analyze multiple parameters in the water treatment process with little need for maintenance, calibration, or operator intervention. The company has experienced a compound annual growth rate of 40 percent over its 15-year history as a direct result of the technology's success.

  1. Analyzing machine noise for real time maintenance (United States)

    Yamato, Yoji; Fukumoto, Yoshifumi; Kumazaki, Hiroki


    Recently, IoT technologies have been progressed and applications of maintenance area are expected. However, IoT maintenance applications are not spread in Japan yet because of one-off solution of sensing and analyzing for each case, high cost to collect sensing data and insufficient maintenance automation. This paper proposes a maintenance platform which analyzes sound data in edges, analyzes only anomaly data in cloud and orders maintenance automatically to resolve existing technology problems. We also implement a sample application and compare related work.

  2. Random Bin for Analyzing Neuron Spike Trains

    Directory of Open Access Journals (Sweden)

    Shinichi Tamura


    Full Text Available When analyzing neuron spike trains, it is always the problem of how to set the time bin. Bin width affects much to analyzed results of such as periodicity of the spike trains. Many approaches have been proposed to determine the bin setting. However, these bins are fixed through the analysis. In this paper, we propose a randomizing method of bin width and location instead of conventional fixed bin setting. This technique is applied to analyzing periodicity of interspike interval train. Also the sensitivity of the method is presented.

  3. Polarization of Saturn's moon Iapetus (United States)

    Ejeta, C. T.; Boehnhardt, H.; Bagnulo, S.; Muinonen, K.; Kolokolova, L.; Tozzi, G.


    One way to constrain the surface properties of atmosphereless solar system objects is to investigate the properties of the polarized light scattered from their surfaces. Using FORS2 instrument of the ESO VLT, we have carried out a series of polarization measurements of Saturn's moon Iapetus, with an accuracy of ~0.1%, over the maximum phase angle range accessible from the ground (~ 6.0 deg), and over a broad spectral range (400 - 900 nm); thereby identifying the polarimetric characteristics of the bright surface material on its trailing side and, that of the dark material on its leading side. While our linear polarizatiom measurements of Iapetus' two hemispheres show an opposite trend of phase angle dependence, the polarization values measured for the two hemispheres around similar phase angles (between ~3 - 6.0deg) differ by a factor of three. Aimed at providing a quantitative assessment of the polarization observed for Iapetus, we have also carried out simulation of the scattering and absorption properties of light by a medium consisting of spherical volume of randomly positioned monodisperse particles. For this purpose, we used the numerically exact solutions of the Maxwell equations employing the multiple sphere T-matrix method [1]. The modeling entails physical characteristics of the particulate surface such as, porosity of the particulate medium; the number of constituent particles; the size, and optical properties of the scatterers. Our model has retrived, a particle size of ~ 0.10 ≤ r ≤ 0.20μm is dominating both the dark and bright material of Iapetus. Moreover, utilizing the scattering matrix parametrization for single-particle scattering with double Henyey-Greenstein (2HG) scattering phase function, to characterize the resulting multiple scattering, we have carried out coherent backscattering simulations for a spherical random media of scatterers [2], with the goal to obtain polarimetric phase function of Iapetus. The geometric albedo values of

  4. Polar Plate Theory for Orthogonal Anisotropy (United States)

    Bailey, Michelle D.; Bower, Mark V.


    Laminated fiber-reinforced (or filamentary) composites are used today for their high strength-to-weight and stiffness-to-weight ratios. However, because of the anisotropic behavior of composites, determining the response on a macroscopic scale is challenging. This is particularly evident in the evaluation of the governing differential equations of a circular disk with the fibers of the lamina oriented with rectilinear orthogonality. This includes any situation involving a composite plate of circular geometry in which out-of-plane displacements due to load are desired, such as fastener pull through loading of a composite plate. Current analysis techniques use numerical methods with rectilinear coordinate systems to solve problems with circular geometry. These analyses over predict plate stiffness by 20% and underpredict failure by 70%. Consequently, there is a need to transform classical composite plate theory to a polar coordinate system. In order to better analyze structures with circular geometries the classical composite plate equations are transformed into the plate equations for a rectilinearly anisotropic composite in polar coordinates. A composite plate is typically a laminate of fibers in rectilinear directions. Subsequent to the lay-tip the necessary geometry is cut out of a rectangular plate. In a similar manner, the derivation of the plate equation starts with the fundamental definitions of strain, displacement and curvature and incorporates the material property angular dependence into the equilibrium equations for a differential polar element. In the transformed state, the stiffness coefficients are no longer constant, adding to the complexity of the governing differential equations. This paper discusses the new derivation and evaluation of the plate equations for a circular composite disk with orthogonal rectilinear anisotropy. The resultant new three partial differential equations, which describe the circular anisotropic plate, can be used to

  5. The High-Energy Polarization-Limiting Radius of Neutron Star Magnetospheres 1, Slowly Rotating Neutron Stars

    CERN Document Server

    Heyl, J S; Lloyd, D; CERN. Geneva; Heyl, Jeremy S.; Shaviv, Nir J.; Lloyd, Don


    In the presence of strong magnetic fields, the vacuum becomes a birefringent medium. We show that this QED effect decouples the polarization modes of photons leaving the NS surface. Both the total intensity and the intensity in each of the two modes is preserved along a ray's path through the neutron-star magnetosphere. We analyze the consequences that this effect has on aligning the observed polarization vectors across the image of the stellar surface to generate large net polarizations. Counter to previous predictions, we show that the thermal radiation of NSs should be highly polarized even in the optical. When detected, this polarization will be the first demonstration of vacuum birefringence. It could be used as a tool to prove the high magnetic field nature of AXPs and it could also be used to constrain physical NS parameters, such as $R/M$, to which the net polarization is sensitive.

  6. Polarized constituent quarks in NLO approximation

    Energy Technology Data Exchange (ETDEWEB)

    Khorramian, Ali N. [Physics Department, Semnan University, Semnan, Iran and Institute for Studies in Theoretical Physics and Mathematics , P.O.Box 19395-5531, Tehran (Iran, Islamic Republic of); Tehrani, S. Atashbar [Physics Department, Persian Gulf University, Boushehr, Iran and Institute for Studies in Theoretical Physics and Mathematics , P.O.Box 19395-5531, Tehran (Iran, Islamic Republic of); Mirjalili, A. [Physics Department, Persian Gulf University, Boushehr, Iran and Institute for Studies in Theoretical Physics and Mathematics , P.O.Box 19395-5531, Tehran (Iran, Islamic Republic of)


    The valon representation provides a basis between hadrons and quarks, in terms of which the bound-state and scattering properties of hadrons can be united and described. We studied polarized valon distributions which have an important role in describing the spin dependence of parton distribution in leading and next-to-leading order approximation. Convolution integral in frame work of valon model as a useful tool, was used in polarized case. To obtain polarized parton distributions in a proton we need to polarized valon distribution in a proton and polarized parton distributions inside the valon. We employed Bernstein polynomial averages to get unknown parameters of polarized valon distributions by fitting to available experimental data.

  7. Meanderline Array Radome Polarizers for practical applications (United States)

    Epis, J. J.

    Meanderline Array Radome Polarizers (MLARP's) can be placed on many types of apertures to provide circularly polarized, directional radiation patterns of many shapes and/or E- and H-plane beamwidth ratios, or on cylindrical apertures of biconical and disk-cone antennas to obtain CP omni-azimuthal patterns. The MLARP also serves as a radome, and has a bandwidth capability which is much broader than other types of aperture polarizers. Equations are derived for calculation of the input VSWR and polarization axial ratio. Important differences between the practical factors involved in developing such radome polarizers for receiving verses transmitting application are discussed. It is shown that this type of radome polarizer can provide axial ratios under 3 dB over a two-octave bandwidth; a 9:1 bandwidth is even achievable for axial ratios under 6 dB in receiving applications.

  8. Oocytes Polar Body Detection for Automatic Enucleation

    Directory of Open Access Journals (Sweden)

    Di Chen


    Full Text Available Enucleation is a crucial step in cloning. In order to achieve automatic blind enucleation, we should detect the polar body of the oocyte automatically. The conventional polar body detection approaches have low success rate or low efficiency. We propose a polar body detection method based on machine learning in this paper. On one hand, the improved Histogram of Oriented Gradient (HOG algorithm is employed to extract features of polar body images, which will increase success rate. On the other hand, a position prediction method is put forward to narrow the search range of polar body, which will improve efficiency. Experiment results show that the success rate is 96% for various types of polar bodies. Furthermore, the method is applied to an enucleation experiment and improves the degree of automatic enucleation.

  9. Terahertz polarization imaging for colon cancer detection (United States)

    Doradla, Pallavi; Alavi, Karim; Joseph, Cecil S.; Giles, Robert H.


    Continuous wave terahertz (THz) imaging has the potential to offer a safe, noninvasive medical imaging modality for delineating colorectal cancer. The terahertz reflectance measurements of fresh 3 - 5 mm thick human colonic excisions were acquired using a continuous-wave polarization imaging technique. A CO2 optically pumped Far- Infrared molecular gas laser operating at 584 GHz was used to illuminate the colon tissue, while the reflected signals were detected using a liquid Helium cooled silicon bolometer. Both co-polarized and cross-polarized remittance from the samples was collected using wire grid polarizers in the experiment. The experimental analysis of 2D images obtained from THz reflection polarization imaging techniques showed intrinsic contrast between cancerous and normal regions based on increased reflection from the tumor. Also, the study demonstrates that the cross-polarized terahertz images not only correlates better with the histology, but also provide consistent relative reflectance difference values between normal and cancerous regions for all the measured specimens.

  10. Effects of climate change on polar bears. (United States)

    Wiig, Øystein; Aars, Jon; Born, Erik W


    In this article, we review the effects on polar bears of global warming that have already been observed, and try to evaluate what may happen to the polar bears in the future. Many researchers have predicted a wide range of impacts of climate change on polar bear demography and conditions. A predicted major reduction in sea ice habitat will reduce the availability of ice associated seals, the main prey of polar bears, and a loss and fragmentation of polar bear habitat will ultimately lead to large future reductions in most subpopulations. It is likely that polar bears will be lost from many areas where they are common today and also that the total population will change into a few more distinctly isolated populations.

  11. On-line chemical composition analyzer development

    Energy Technology Data Exchange (ETDEWEB)

    Garrison, A.A.


    This report relates to the development of an on-line Raman analyzer for control of a distillation column. It is divided into: program issues, experimental control system evaluation, energy savings analysis, and reliability analysis. (DLC)

  12. On-Demand Urine Analyzer Project (United States)

    National Aeronautics and Space Administration — The overall goal of this program (through Phase III) is to develop an analyzer that can be integrated into International Space Station (ISS) toilets to measure key...

  13. Analyzing the economic impacts of transportation projects. (United States)


    The main goal of the study is to explore methods, approaches and : analytical software tools for analyzing economic activity that results from largescale : transportation investments in Connecticut. The primary conclusion is that the : transportation...

  14. Ultrasensitive Atmospheric Analyzer for Miniature UAVs Project (United States)

    National Aeronautics and Space Administration — In this SBIR Phase I effort, Los Gatos Research (LGR) proposes to develop a highly-accurate, lightweight, low-power gas analyzer for quantification of water vapor...

  15. Low Gravity Drug Stability Analyzer Project (United States)

    National Aeronautics and Space Administration — The goal of this proposed program through Phase III is to build a space-worthy Drug Stability Analyzer that can determine the extent of drug degradation. It will be...

  16. Low Gravity Drug Stability Analyzer Project (United States)

    National Aeronautics and Space Administration — The overall goal of this proposed program (through Phase III) is to build a space-worthy Drug Stability Analyzer that can determine the extent of drug degradation....

  17. A Portable, Field-Deployable Analyzer for Isotopic Water Measurements (United States)

    Berman, E. S.; Gupta, M.; Huang, Y. W.; Lacelle, D.; McKay, C. P.; Fortson, S.


    Water stable isotopes have for many years been used to study the hydrological cycle, catchment hydrology, and polar climate among other applications. Typically, discrete water samples are collected and transported to a laboratory for isotope analysis. Due to the expense and labor associated with such sampling, isotope studies have generally been limited in scope and time-resolution. Field sampling of water isotopes has been shown in recent years to provide dense data sets with the increased time resolution illuminating substantially greater short term variability than is generally observed during discrete sampling. A truly portable instrument also opens the possibility to utilize the instrument as a tool for identifying which water samples would be particularly interesting for further laboratory investigation. To make possible such field measurements of liquid water isotopes, Los Gatos Research has developed a miniaturized, field-deployable liquid water isotope analyzer. The prototype miniature liquid water isotope analyzer (mini-LWIA) uses LGR's patented Off-Axis ICOS (Integrated Cavity Output Spectroscopy) technology in a rugged, Pelican case housing for easy transport and field operations. The analyzer simultaneously measures both δ2H and δ18O from liquid water, with both manual and automatic water introduction options. The laboratory precision for δ2H is 0.6 ‰, and for δ18O is 0.3 ‰. The mini-LWIA was deployed in the high Arctic during the summer of 2015 at Inuvik in the Canadian Northwest Territories. Samples were collected from Sachs Harbor, on the southwest coast of Banks Island, including buried basal ice from the Lurentide Ice Sheet, some ice wedges, and other types of ground ice. Methodology and water analysis results from this extreme field deployment will be presented.

  18. Study on the polarity, solubility, and stacking characteristics of asphaltenes

    KAUST Repository

    Zhang, Long-li


    The structure and transformation of fused aromatic ring system in asphaltenes play an important role in the character of asphaltenes, and in step affect the properties of heavy oils. Polarity, solubility and structural characteristics of asphaltenes derived from Tahe atmospheric residue (THAR) and Tuo-826 heavy crude oil (Tuo-826) were analyzed for study of their internal relationship. A fractionation method was used to separate the asphaltenes into four sub-fractions, based on their solubility in the mixed solvent, for the study of different structural and physical-chemical properties, such as polarity, solubility, morphology, stacking characteristics, and mean structural parameters. Transmission electron microscope (TEM) observation can present the intuitive morphology of asphaltene molecules, and shows that the structure of asphaltenes is in local order as well as long range disorder. The analysis results showed that n-heptane asphaltenes of THAR and Tuo-826 had larger dipole moment values, larger fused aromatic ring systems, larger mean number of stacking layers, and less interlayer spacing between stacking layers than the corresponding n-pentane asphaltenes. The sub-fractions that were inclined to precipitate from the mixture of n-heptane and tetrahydrofuran had larger polarity and less solubility. From the first sub-fraction to the fourth sub-fraction, polarity, mean stacking numbers, and average layer size from the TEM images follow a gradual decrease. The structural parameters derived from TEM images could reflect the largest fused aromatic ring system in asphaltene molecule, yet the parameters derived from 1H NMR data reflected the mean message of poly-aromatic ring systems. The structural parameters derived from TEM images were more consistent with the polarity variation of sub-fractions than those derived from 1H NMR data, which indicates that the largest fused aromatic ring system will play a more important role in the stacking characteristics of

  19. Ricean Bias Correction in Linear Polarization Observation


    Bong Won Sohn


    I developed an enhanced correction method for Ricean bias which occurs in linear polarization measurement. Two known methods for Ricean bias correction are reviewed. In low signal-to-noise area, the method based on the mode of the equation gives better representation of the fractional polarization. But a caution should be given that the accurate estimation of noise level, i.e. σ of the polarized flux, is important. The maximum likelihood method is better choice for high signal-to-...

  20. RHIC polarized proton performance in run-8.

    Energy Technology Data Exchange (ETDEWEB)

    Montag,C.; Abreu, N.; Ahrens, L.; Bai, M.; Barton, D.; et al.


    During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Helical spin rotators at these two interaction regions were used to control the spin orientation of both beams at the collision points. Physics data were taken with different orientations of the beam polarization. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8.

  1. Comments to a polar bear population model


    Øritsland, Nils Are


    Larsen, T. & Ugland, K. I. (Polar Research 2 n.s., 117-118) note correctly that a Leslie matrix model treats cubs and females as independent units which is not the case for polar bears. Population projections using the Leslie model with hunting mortalities added are instructive first approximations in evaluations of field data, however, and are recommended as exercises also for polar bear biologists. An APL programme for such projections is available.

  2. The origin of radio pulsar polarization (United States)

    Dyks, J.


    Polarization of radio pulsar profiles involves a number of poorly understood, intriguing phenomena, such as the existence of comparable amounts of orthogonal polarization modes (OPMs), strong distortions of polarization angle (PA) curves into shapes inconsistent with the rotating vector model (RVM), and the strong circular polarization V which can be maximum (instead of zero) at the OPM jumps. It is shown that the comparable OPMs and large V result from a coherent addition of phase-delayed waves in natural propagation modes, which are produced by a linearly polarized emitted signal. The coherent mode summation implies opposite polarization properties to those known from the incoherent case, in particular, the OPM jumps occur at peaks of V, whereas V changes sign at a maximum linear polarization fraction L/I. These features are indispensable to interpret various observed polarization effects. It is shown that statistical properties of emission and propagation can be efficiently parametrized in a simple model of coherent mode addition, which is successfully applied to complex polarization phenomena, such as the stepwise PA curve of PSR B1913+16 and the strong PA distortions within core components of pulsars B1933+16 and B1237+25. The inclusion of coherent mode addition opens the possibility for a number of new polarization effects, such as inversion of relative modal strength, twin minima in L/I coincident with peaks in V, 45° PA jumps in weakly polarized emission, and loop-shaped core PA distortions. The empirical treatment of the coherency of mode addition makes it possible to advance the understanding of pulsar polarization beyond the RVM model.

  3. Primordial Inflation Polarization Explorer: Status and Plans (United States)

    Kogut, Alan


    The Primordial Inflation Polarization Explorer is a balloon-borne instrument to measure the polarization of the cosmic microwave background in order to detect the characteristic signature of gravity waves created during an inflationary epoch in the early universe. PIPER combines cold /I.G K\\ optics, 5120 bolometric detectors, and rapid polarization modulation using VPM grids to achieve both high sensitivity and excellent control of systematic errors. I will discuss the current status and plans for the PIPER instrument.

  4. Physical processes in spin polarized plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Kulsrud, R.M.; Valeo, E.J.; Cowley, S.


    If the plasma in a nuclear fusion reactor is polarized, the nuclear reactions are modified in such a way as to enhance the reactor performance. We calculate in detail the modification of these nuclear reactions by different modes of polarization of the nuclear fuel. We also consider in detail the various physical processes that can lead to depolarization and show that they are by and large slow enough that a high degree of polarization can be maintained.

  5. The polarization and beaming effect for GRBs


    Cheng, K. S.; Fan, J. H.; Dai, Z. G.


    Both observations and theoretical models suggest that the emissions in gamma-ray bursts (GRBs) and the afterglows are beamed. We argue that the recent polarization measured in the afterglows gives further evidence of beaming in GRBs. In this approach, we adopted the polarization-magnitude relation of BL Lacertae objects to 4 GRBs with available polarization measurements and found that the data of the 4 GRBs are consistent with the relation of BL Lacertae objects. This result suggests that the...

  6. Polar Field Reversals and Active Region Decay (United States)

    Petrie, Gordon; Ettinger, Sophie


    We study the relationship between polar field reversals and decayed active region magnetic flux. Photospheric active region flux is dispersed by differential rotation and turbulent diffusion, and is transported poleward by meridional flows and diffusion. We summarize the published evidence from observation and modeling of the influence of meridional flow variations and decaying active region flux's spatial distribution, such as the Joy's law tilt angle. Using NSO Kitt Peak synoptic magnetograms covering cycles 21-24, we investigate in detail the relationship between the transport of decayed active region flux to high latitudes and changes in the polar field strength, including reversals in the magnetic polarity at the poles. By means of stack plots of low- and high-latitude slices of the synoptic magnetograms, the dispersal of flux from low to high latitudes is tracked, and the timing of this dispersal is compared to the polar field changes. In the most abrupt cases of polar field reversal, a few activity complexes (systems of active regions) are identified as the main cause. The poleward transport of large quantities of decayed trailing-polarity flux from these complexes is found to correlate well in time with the abrupt polar field changes. In each case, significant latitudinal displacements were found between the positive and negative flux centroids of the complexes, consistent with Joy's law bipole tilt with trailing-polarity flux located poleward of leading-polarity flux. The activity complexes of the cycle 21 and 22 maxima were larger and longer-lived than those of the cycle 23 and 24 maxima, and the poleward surges were stronger and more unipolar and the polar field changes larger and faster. The cycle 21 and 22 polar reversals were dominated by only a few long-lived complexes whereas the cycle 23 and 24 reversals were the cumulative effects of more numerous, shorter-lived regions. We conclude that sizes and lifetimes of activity complexes are key to

  7. Polarization-sensitive color in butterfly scales: polarization conversion from ridges with reflecting elements. (United States)

    Zhang, Ke; Tang, Yiwen; Meng, Jinsong; Wang, Ge; Zhou, Han; Fan, Tongxiang; Zhang, Di


    Polarization-sensitive color originates from polarization-dependent reflection or transmission, exhibiting abundant light information, including intensity, spectral distribution, and polarization. A wide range of butterflies are physiologically sensitive to polarized light, but the origins of polarized signal have not been fully understood. Here we systematically investigate the colorful scales of six species of butterfly to reveal the physical origins of polarization-sensitive color. Microscopic optical images under crossed polarizers exhibit their polarization-sensitive characteristic, and micro-structural characterizations clarify their structural commonality. In the case of the structural scales that have deep ridges, the polarization-sensitive color related with scale azimuth is remarkable. Periodic ridges lead to the anisotropic effective refractive indices in the parallel and perpendicular grating orientations, which achieves form-birefringence, resulting in the phase difference of two different component polarized lights. Simulated results show that ridge structures with reflecting elements reflect and rotate the incident p-polarized light into s-polarized light. The dimensional parameters and shapes of grating greatly affect the polarization conversion process, and the triangular deep grating extends the outstanding polarization conversion effect from the sub-wavelength period to the period comparable to visible light wavelength. The parameters of ridge structures in butterfly scales have been optimized to fulfill the polarization-dependent reflection for secret communication. The structural and physical origin of polarization conversion provides a more comprehensive perspective on the creation of polarization-sensitive color in butterfly wing scales. These findings show great potential in anti-counterfeiting technology and advanced optical material design.

  8. Unconventional superfluids of fermionic polar molecules in a bilayer system

    Energy Technology Data Exchange (ETDEWEB)

    Boudjemâa, Abdelâali, E-mail:


    We study unconventional superfluids of fermionic polar molecules in a two-dimensional bilayer system with dipoles are head-to-tail across the layers. We analyze the critical temperature of several unconventional pairings as a function of different system parameters. The peculiar competition between the d- and the s-wave pairings is discussed. We show that the experimental observation of such unconventional superfluids requires ultralow temperatures, which opens up new possibilities to realize several topological phases. - Highlights: • Investigation of novel superfluids of fermionic polar molecules in a bilayer geometry. • Solving the gap equation and the l-wave interlayer scattering problem. • Calculation of the critical temperature of several competing pairings using the BCS approach.

  9. Ultrasmall polarization rotation measurements via weak value amplification

    Energy Technology Data Exchange (ETDEWEB)

    Lima Bernardo, Bertúlio de, E-mail:; Azevedo, Sérgio; Rosas, Alexandre


    Highlights: • We present a class of weak measurements where the measurer is an angular variable of the system. • Photon-energy qubits are required, which seems to be the first application of this kind of light. • Both weak optical activity and reflection-induced polarization rotation can be amplified. • This protocol can amplify the optical activity signal in nanostructures and biological tissues. - Abstract: We propose a framework to analyze weak measurements based on an angular version of the von Neumann measurement scheme, where the coupling between the system and the meter causes rotation of the measuring variable. We also discuss an experimental application of this theory in which measurements of weak optical activity and reflection-induced polarization rotation could be amplified in nearly two orders of magnitude. It can shed a new light on a great variety of physical chemistry, molecular biology and nanotechnology studies.

  10. Dual-Polarized Planar Phased Array Analysis for Meteorological Applications

    Directory of Open Access Journals (Sweden)

    Chen Pang


    Full Text Available This paper presents a theoretical analysis for the accuracy requirements of the planar polarimetric phased array radar (PPPAR in meteorological applications. Among many factors that contribute to the polarimetric biases, four factors are considered and analyzed in this study, namely, the polarization distortion due to the intrinsic limitation of a dual-polarized antenna element, the antenna pattern measurement error, the entire array patterns, and the imperfect horizontal and vertical channels. Two operation modes, the alternately transmitting and simultaneously receiving (ATSR mode and the simultaneously transmitting and simultaneously receiving (STSR mode, are discussed. For each mode, the polarimetric biases are formulated. As the STSR mode with orthogonal waveforms is similar to the ATSR mode, the analysis is mainly focused on the ATSR mode and the impacts of the bias sources on the measurement of polarimetric variables are investigated through Monte Carlo simulations. Some insights of the accuracy requirements are obtained and summarized.

  11. Magnetohydrodynamic waves in coronal polar plumes. (United States)

    Nakariakov, Valery M


    Polar plumes are cool, dense, linear, magnetically open structures that arise from predominantly unipolar magnetic footpoints in the solar polar coronal holes. As the Alfvén speed is decreased in plumes in comparison with the surrounding medium, these structures are natural waveguides for fast and slow magnetoacoustic waves. The simplicity of the geometry of polar plumes makes them an ideal test ground for the study of magnetohydrodynamic (MHD) wave interaction with solar coronal structures. The review covers recent observational findings of compressible and incompressible waves in polar plumes with imaging and spectral instruments, and interpretation of the waves in terms of MHD theory.

  12. Symposium melds past and future polar research (United States)

    Johnson, Leonard

    An international symposium, Perspectives of Modern Polar Research, was convened in Bad Durkeim, Germany to celebrate the 175th anniversary of the birth of Georg von Neumayer, the noted polar explorer and facilitator of German and international polar science. Neumayer, who lived from 1826 to 1909, began his career as a seaman in the merchant marine. Through his skill in geophysics and meteorology, he rose to become the founder and director of the Flagstaff Observatory in Melbourne, Australia, hydrographer to the German Navy, and director of the Hamburg Oceanic Observatory. He was instrumental in organizing the first International Polar Year (IPY) in 1882-1883.

  13. Polarized light in optics and spectroscopy

    CERN Document Server

    Kliger, David S


    This comprehensive introduction to polarized light provides students and researchers with the background and the specialized knowledge needed to fully utilize polarized light. It provides a basic introduction to the interaction of light with matter for those unfamiliar with photochemistry and photophysics. An in-depth discussion of polarizing optics is also given. Different analytical techniques are introduced and compared and introductions to the use of polarized light in various forms of spectroscopy are provided.Key Features* Starts at a basic level and develops tools for resear

  14. Optimal axes of Siberian snakes for polarized proton acceleration

    Directory of Open Access Journals (Sweden)

    Georg H. Hoffstaetter


    Full Text Available Accelerating polarized proton beams and storing them for many turns can lead to a loss of polarization when accelerating through energies where a spin rotation frequency is in resonance with orbit oscillation frequencies. First-order resonance effects can be avoided by installing Siberian snakes in the ring, devices which rotate the spin by 180° around the snake axis while not changing the beam’s orbit significantly. For large rings, several Siberian snakes are required. Here a criterion will be derived that allows one to find an optimal choice for the orientation of the snake axes. Rings with superperiod four are analyzed in detail, and the HERA proton ring is used as an example for approximate fourfold symmetry. The proposed arrangement of Siberian snakes matches their effects so that all spin-orbit coupling integrals vanish at all energies and therefore there is no first-order spin-orbit coupling at all for this choice, which I call snake matching. It will be shown that in general at least eight Siberian snakes are needed and that there are exactly four possibilities to arrange their axes. When the betatron phase advance between snakes is chosen suitably, four Siberian snakes can be sufficient. Since the spin motion depends on a particle’s trajectory, protons at different phase space positions generally have different spin directions. The time averaged polarization at each phase space point is parallel to the invariant spin field, and the spread of this spin field limits the polarization that can be stored. By the here presented choice of Siberian snakes this limit is completely eliminated up to first order in the transverse phase space coordinates. The invariant spin field and the amplitude-dependent spin tune are also computed without linearization to show the advantages of this choice of snakes. Ultimately, the goal of snake matching is to reduce the loss of polarization during the acceleration of the beam. To show that a favorable

  15. A novel x-ray circularly polarized ranging method (United States)

    Song, Shi-Bin; Xu, Lu-Ping; Zhang, Hua; Gao, Na; Shen, Yang-He


    Range measurement has found multiple applications in deep space missions. With more and further deep space exploration activities happening now and in the future, the requirement for range measurement has risen. In view of the future ranging requirement, a novel x-ray polarized ranging method based on the circular polarization modulation is proposed, termed as x-ray circularly polarized ranging (XCPolR). XCPolR utilizes the circular polarization modulation to process x-ray signals and the ranging information is conveyed by the circular polarization states. As the circular polarization states present good stability in space propagation and x-ray detectors have light weight and low power consumption, XCPolR shows great potential in the long-distance range measurement and provides an option for future deep space ranging. In this paper, we present a detailed illustration of XCPolR. Firstly, the structure of the polarized ranging system is described and the signal models in the ranging process are established mathematically. Then, the main factors that affect the ranging accuracy, including the Doppler effect, the differential demodulation, and the correlation error, are analyzed theoretically. Finally, numerical simulation is carried out to evaluate the performance of XCPolR. Projects supported by the National Natural Science Foundation of China (Grant Nos. 61172138 and 61401340), the Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2013JQ8040), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20130203120004), the Open Research Fund of the Academy of Satellite Application, China (Grant No. 2014 CXJJ-DH 12), the Xi’an Science and Technology Plan, China (Grant No. CXY1350(4)), the Fundamental Research Funds for the Central Universities, China (Grant Nos. 201413B, 201412B, and JB141303), and the Open Fund of Key Laboratory of Precision Navigation and Timing Technology, National Time Service Center, Chinese

  16. Properties of electric turbulence in the polar cap ionosphere (United States)

    Golovchanskaya, I. V.; Kozelov, B. V.


    Small-scale (scales of ˜0.5-256 km) electric fields in the polar cap ionosphere are studied on the basis of measurements of the Dynamics Explorer 2 (DE-2) low-altitude satellite with a polar orbit. Nineteen DE-2 passes through the high-latitude ionosphere from the morning side to the evening side are considered when the IMF z component was southward. A rather extensive polar cap, which could be identified using the ɛ- t spectrograms of precipitating particles with auroral energies, was formed during the analyzed events. It is shown that the logarithmic diagrams (LDs), constructed using the discrete wavelet transform of electric fields in the polar cap, are power law (μ ˜ s α). Here, μ is the variance of the detail coefficients of the signal discrete wavelet transform, s is the wavelet scale, and index α characterizes the LD slope. The probability density functions P(δ E, s) of the electric field fluctuations δ E observed on different scales s are non-Gaussian and have intensified wings. When the probability density functions are renormalized, that is constructed of δ E/ s γ, where γ is the scaling exponent, they lie near a single curve, which indicates that the studied fields are statistically self-similar. In spite of the fact that the amplitude of electric fluctuations in the polar cap is much smaller than in the auroral zone, the quantitative characteristics of field scaling in the two regions are similar. Two possible causes of the observed turbulent structure of the electric field in the polar cap are considered: (1) the structure is transferred from the solar wind, which is known to have turbulent properties, and (2) the structure is generated by convection velocity shears in the region of open magnetic field lines. The detected dependence of the characteristic distribution of turbulent electric fields over the polar cap region on IMF B y and the correlation of the rms amplitudes of δ E fluctuations with IMF B z and the solar wind transfer

  17. Mitigating Multipath Bias Using a Dual-Polarization Antenna: Theoretical Performance, Algorithm Design, and Simulation

    Directory of Open Access Journals (Sweden)

    Lin Xie


    Full Text Available It is well known that multipath effect remains a dominant error source that affects the positioning accuracy of Global Navigation Satellite System (GNSS receivers. Significant efforts have been made by researchers and receiver manufacturers to mitigate multipath error in the past decades. Recently, a multipath mitigation technique using dual-polarization antennas has become a research hotspot for it provides another degree of freedom to distinguish the line-of-sight (LOS signal from the LOS and multipath composite signal without extensively increasing the complexity of the receiver. Numbers of multipath mitigation techniques using dual-polarization antennas have been proposed and all of them report performance improvement over the single-polarization methods. However, due to the unpredictability of multipath, multipath mitigation techniques based on dual-polarization are not always effective while few studies discuss the condition under which the multipath mitigation using a dual-polarization antenna can outperform that using a single-polarization antenna, which is a fundamental question for dual-polarization multipath mitigation (DPMM and the design of multipath mitigation algorithms. In this paper we analyze the characteristics of the signal received by a dual-polarization antenna and use the maximum likelihood estimation (MLE to assess the theoretical performance of DPMM in different received signal cases. Based on the assessment we answer this fundamental question and find the dual-polarization antenna’s capability in mitigating short delay multipath—the most challenging one among all types of multipath for the majority of the multipath mitigation techniques. Considering these effective conditions, we propose a dual-polarization sequential iterative maximum likelihood estimation (DP-SIMLE algorithm for DPMM. The simulation results verify our theory and show superior performance of the proposed DP-SIMLE algorithm over the traditional one

  18. Optimization of polarizer azimuth in improving domain image contrast in magneto-optical Kerr microscope (United States)

    Wang, X.; Lian, J.; Li, P.; Li, X.; Li, M. M.; Wang, Y.; Liu, Y. X.


    The magneto-optical Kerr effect (MOKE) is a widely used technique in magnetic domain imaging for its high surface sensitivity and external magnetic compatibility. In this work, we use the generalized magneto-optical ellipsometry technique to study the influence of polarizer and analyzer azimuth on domain image contrast in the Kerr microscope. Results show that the image contrasts around the extinction place are larger than other area. When the polarizer and analyzer are set slightly deviated from the extinction condition (0.35°,89.7°), the maximum image contrast can be obtained. The color map of image contrast on polarizer and analyzer angle is given by measuring the MOKE response of 200 nm permalloy. Results verify the validity of the conclusion.

  19. Polarized beam splitting effect in inhomogeneously magnetized magnetooptic films. (United States)

    Waring, M


    Linearly polarized light passing through a several micron thick magnetooptic film in the inhomogeneous magnetization state is split into a linearly polarized central beam and linearly polarized first and higher order diverging rings. The polarization of the central output beam lies in the same direction as the linearly polarized input, while the polarization of the diverging rings lies in a direction orthogonal to the input plane of polarization. The effect is described, and applications of the effect are discussed.

  20. How campaigns polarize the electorate

    DEFF Research Database (Denmark)

    Hansen, Kasper Møller; Kosiara-Pedersen, Karina


    The minimal effect theory of campaign studies stipulates that intense political competition during campaigns assures and reinforces the initial party choice of the electorate. We find that this reinforcement is two-fold. During the campaign, the party preference of the voters’ in-group party...... increases while the party preference of the voters’ out-group parties decreases. Voters’ preference for their most preferred party (MPP) increases during the election campaign, while their preference for their least liked party decreases during the campaign (LPP). Across parties voters experience...... an increase in their preference for their most preferred party and a decrease for their least liked party as the campaign progresses. These trends show that the political campaign polarizes the electorate by increasing the affective distance between in-group party and out-group party preferences, thereby...

  1. Polarization of physics on global courses (United States)

    Alinea, Allan L.; Naylor, Wade


    Since October 2010, the Chemistry-Biology Combined Major Program, an international course taught in English at Osaka University, has been teaching small classes (no more than 20 in size). We present data from the Force Concept Inventory (FCI) given to first-year classical mechanics students (N = 47 students over three years) pre and post score, for a class that predominantly uses interactive engagement, such as MasteringPhysics. Our findings show a G-factor improved score of about ˜0.18, which is marginally about the average of a traditional-based course. Furthermore, we analyze in detail a set of six questions from the FCI, involving the identification of forces acting on a body. We find that student answers tend to cluster about ‘polarizing choices’—a pair of choices containing the correct choice and a wrong choice, with the latter corresponding to a superset of forces in the former. Our results are suggestive that students have a good idea of the right set of forces acting on a given system, but the inclusion of extra force(s) brings about confusion; something that may be explained by misleading ontological categorization of forces. In an appendix A we also comment on possible correlations between the pre/post score and the level of English ability on entry to the course.

  2. Geometric invariant theory for polarized curves

    CERN Document Server

    Bini, Gilberto; Melo, Margarida; Viviani, Filippo


    We investigate GIT quotients of polarized curves. More specifically, we study the GIT problem for the Hilbert and Chow schemes of curves of degree d and genus g in a projective space of dimension d-g, as d decreases with respect to g. We prove that the first three values of d at which the GIT quotients change are given by d=a(2g-2) where a=2, 3.5, 4. We show that, for a>4, L. Caporaso's results hold true for both Hilbert and Chow semistability. If 3.5analyze in detail the critical values a=3.5 and a=4, where the Hilbert semistable locus is strictly smaller than the Chow semistable locus. As an application, we obtain three compactications of the universal Jacobian over the moduli space of stable curves, weakly-pseudo-stable curves and pseu...

  3. Electrokinetics of Polar Liquids in Contact with Non-Polar Surfaces


    Lin, Chih-Hsiu; Ferguson, Gregory S.; Chaudhury, Manoj K.


    Zeta potentials of several polar protic (water, ethylene glycol, formamide) as well as polar aprotic (dimethyl sulfoxide) liquids were measured in contact with three non-polar surfaces using closed-cell electro-osmosis. The test surfaces were chemisorbed monolayers of alkyl siloxanes, fluoroalkyl siloxanes and polydimethylsiloxanes (PDMS) grafted on glass slides. All these liquids exhibited substantial electrokinetics in contact with the non-polar surfaces with these observations: the electro...

  4. Solar Magnetism in the Polar Regions

    Directory of Open Access Journals (Sweden)

    Gordon J. D. Petrie


    Full Text Available This review describes observations of the polar magnetic fields, models for the cyclical formation and decay of these fields, and evidence of their great influence in the solar atmosphere. The polar field distribution dominates the global structure of the corona over most of the solar cycle, supplies the bulk of the interplanetary magnetic field via the polar coronal holes, and is believed to provide the seed for the creation of the activity cycle that follows. A broad observational knowledge and theoretical understanding of the polar fields is therefore an essential step towards a global view of solar and heliospheric magnetic fields. Analyses of both high-resolution and long-term synoptic observations of the polar fields are summarized. Models of global flux transport are reviewed, from the initial phenomenological and kinematic models of Babcock and Leighton to present-day attempts to produce time-dependent maps of the surface magnetic field and to explain polar field variations, including the weakness of the cycle 23 polar fields. The relevance of the polar fields to solar physics extends far beyond the surface layers from which the magnetic field measurements usually derive. As well as discussing the polar fields' role in the interior as seed fields for new solar cycles, the review follows their influence outward to the corona and heliosphere. The global coronal magnetic structure is determined by the surface magnetic flux distribution, and is dominated on large scales by the polar fields. We discuss the observed effects of the polar fields on the coronal hole structure, and the solar wind and ejections that travel through the atmosphere. The review concludes by identifying gaps in our knowledge, and by pointing out possible future sources of improved observational information and theoretical understanding of these fields.

  5. True polar wander on convecting planets (United States)

    Rose, Ian Robert

    the characteristic size of moment of inertia anomalies decreases with higher Ra, but that the characteristic response time for TPW also decreases. These two effects approximately cancel. However, the orientation of the principal axes of the moment of inertia becomes less stable to perturbations at high Ra, thereby increasing the rate of TPW. Overall, I find that a more vigorously convecting planet is more likely to experience large TPW events. If early Earth had more vigorous convection, it may have experienced more TPW than present-day Earth. Flow induced by density anomalies in the mantle deflects free surfaces at the surface and the CMB, and the mass anomalies due to these deflections contribute to the moment of inertia. A full accounting of the moment of inertia anomalies must include these surface effects. Numerical models of mantle convection with a free surface have suffered from numerical sloshing instabilities. I analyze the sloshing instability by constructing a generalized eigenvalue problem for the relaxation time spectrum. The minimum relaxation time of the spectrum sets the maximum stable timestep. This analysis gives the first quantitative explanation for why existing techniques for stabilizing geodynamic simulations with a free surface work. I also use this perspective to construct an alternative stabilization scheme based on nonstandard finite differences. This scheme has a single parameter, given by an estimate of the minimum relaxation time, and allows for still larger timesteps. Finally, I develop a new method for analyzing apparent polar wander (APW) paths described by sequences of paleomagnetic poles. Existing techniques, such as spline fits and running means, do not fully account for the uncertainties in the position and timing of paleomagnetic pole paths. Furthermore, they impose regularization on the solution, and the resulting uncertainties are difficult to interpret. Our technique is an extension of paleomagnetic Euler pole (PEP) analysis. I

  6. PolarTrack: Optical Outside-In Device Tracking that Exploits Display Polarization

    DEFF Research Database (Denmark)

    Rädle, Roman; Jetter, Hans-Christian; Fischer, Jonathan


    PolarTrack is a novel camera-based approach to detecting and tracking mobile devices inside the capture volume. In PolarTrack, a polarization filter continuously rotates in front of an off-the-shelf color camera, which causes the displays of observed devices to periodically blink in the camera feed...

  7. Investigations of Polarization Dependent Loss in Polarization Modulated Analog Optical Links (United States)


    nonlinearity. Finally, the polarization modulator nonlinearities are investigated, with the results showing the tradeoffs for using either the DC bias of a...described below. In ideal operation, the net result of the polarization evolution from the PolM output, through the link and HWP, to a polarization

  8. Analyzing Log Files using Data-Mining

    Directory of Open Access Journals (Sweden)

    Marius Mihut


    Full Text Available Information systems (i.e. servers, applications and communication devices create a large amount of monitoring data that are saved as log files. For analyzing them, a data-mining approach is helpful. This article presents the steps which are necessary for creating an ‘analyzing instrument’, based on an open source software called Waikato Environment for Knowledge Analysis (Weka [1]. For exemplification, a system log file created by a Windows-based operating system, is used as input file.

  9. Analyzing migration phenomena with spatial autocorrelation techniques

    Directory of Open Access Journals (Sweden)

    Giuseppe Borruso


    Full Text Available In less than one century, Italy has tested a strong intensification of immigration changing from a country originating great migration flows to a country which is the destination of migration flows. The aim of this paper is to examine foreign immigration in Italy distinguishing according to nationality of foreigners. The spatial dimension of migration flows has been analyzed in this paper using Spatial Autocorrelation techniques and more particularly Local Indicators of Spatial Association in order to analyze the highest values of a foreigner group considering the relationship with the surrounding municipalities.

  10. Design of a wide band metasurface as a linear to circular polarization converter (United States)

    Altintas, Olcay; Unal, Emin; Akgol, Oguzhan; Karaaslan, Muharrem; Karadag, Faruk; Sabah, Cumali


    In this paper, we present a wide band metasurface (MS) polarization converter which converts a linearly polarized signal to a right-handed or left-handed circularly polarized signal both numerically and experimentally. The unit cell of MS has three nested rectangular resonators which have two metallic patches at its crossed corners. The simulated and measured results are achieved by a commercial full wave EM simulator and a vector network analyzer with two horn antennas in microwave frequency regime. The S-parameters are obtained for co-polarized and cross-polarized responses and axial ratio is evaluated by the division of these two responses. The axial ratio is kept below 3 dB for efficient polarization converting activity. Correspondingly, axial ratio bandwidth of 800 MHz is obtained. The proposed MS can easily be fabricated and integrated into many desired applications by proper configurations depending on the application area and frequencies. The proposed MS has potential such as polarization converter with 0.75 efficiency in WiMAX frequency band, PMC-like treatment with a phase reflection around 0∘ and reflection coefficient nearly unity at some frequency points. Beside this, the three nested rectangle MSs also provide opportunities to design low profile antennas with conversion characteristics.

  11. Physical insight into the polarization dynamics of semiconductor vertical-cavity lasers (United States)

    van Exter, M. P.; Hendriks, R. F. M.; Woerdman, J. P.


    The polarization properties of semiconductor vertical-cavity lasers (VCSELs) are generally described with a model introduced by San Miguel, Feng, and Moloney (SFM) in Phys. Rev. A 52, 1728 (1995). We have analyzed this SFM model from an experimentalist's point of view, using the idea that under certain conditions, which are satisfied by most practical VCSELs, the complicated spin dynamics can be adiabatically eliminated, leading to a managable analytical description. We hereby obtain new physical insight and intuitive pictures. One of the key results is the prediction that, via the spin dynamics, the presence of a strong lasing mode with a certain polarization will effectively lead to a broadening and frequency shift of the weak nonlasing mode with orthogonal polarization. This result gives a simple physical explanation for a polarization switch predicted by the model, and leads to further predictions that can be experimentally verified. The analysis also shows how the relaxation oscillations are related to the polarization dynamics and how they might be of crucial importance to experimentally determine the various parameters in the SFM model. We then discuss how the spin elimination reduces the SFM model to existing models for the polarization dynamics of class A (gas) lasers, with intuitive pictures of the polarization evolution on the Poincaré sphere. Finally we will show how, within the context of adiabatic elimination, the cubic crystalline symmetry plays a special role in possible generalizations of the SFM model.

  12. Neutron polarization evolution calculations along the SNS magnetism reflectometer beam line

    Energy Technology Data Exchange (ETDEWEB)

    Parizzi, Andre de [Oak Ridge National Laboratory, Spallation Neutron Source (SNS), Building 8600, Bethel Valley Road, Oak Ridge, TN 37831 (United States)]. E-mail:; Klose, Frank [Oak Ridge National Laboratory, Spallation Neutron Source (SNS), Building 8600, Bethel Valley Road, Oak Ridge, TN 37831 (United States); Christoph, Volker [University of Applied Sciences (HTW), Dresden (Germany)


    In polarized neutron scattering instruments, most polarization devices apply magnetic fields of different space and time profiles for achieving the desired conditioning of the beam. Magnetic fields created at each device impose fringe/stray fields onto other devices in the beam line, which may affect their functionalities as well as the evolution of the neutron polarization. For the SNS magnetism reflectometer, it is desirable that different sample environment magnets and beam conditioning devices can be used in variable experimental conditions. Spin polarizers and analyzers, broad-band spin flippers and other polarized neutron devices must be capable of working reliably in the vicinity of small magnetic fields generated by an iron-yoke electromagnet and of much larger magnetic fields created, for example, by a high-field superconducting magnet. The latter may not only impose relatively large stray fields along the beam path, but also produce relatively large field gradients. In this paper, we present calculations treating the magnetic field interference between devices, the effect of sample environment magnets and the resultant neutron polarization evolution along the beam line. Calculations are presented for polarized instrumentation configurations that will typically be applied in standard experimental conditions at the SNS magnetism reflectometer.

  13. A novel fibrous duct structure discovered in the brain meninges by using polarized light microscopy (United States)

    Nam, Min-Ho; Jung, Sharon Jiyoon; Soh, Kwang-Sup; Lim, Jaekwan; Seo, Eunseok; Lim, Jun; Baek, Miok; Lee, Sang Joon


    We have previously reported the discovery of a novel fibrous structure (NFS) consisting of unidirectionally arranged collagen fibers in the spinal pia mater. Due to its unique structure, it was easily detected using polarized light microscopy. In the current study, we describe the discovery of a similar NFS in the brain meninges of rats by using polarized light microscopy. This NFS is located beneath the superior sagittal sinus. Initially, we systemically analyzed the polarization properties of the NFS. The change in the light intensity of the NFS, with respect to the polarization angle, was eight times greater than that of blood vessels, showing that the collagen fibers are oriented in a particular direction with almost perfect parallelism (0.99). The orientation angle of the polarization ellipse confirmed the orientation of the collagen fibers in the NFS. Histological studies further confirmed that the unidirectionally arranged collagen fibers were responsible for this distinct polarization property. Surprisingly, X-ray microtomography and 3D confocal imaging revealed that the NFS contains within it a duct structure, a putative primo vessel. In conclusion, we report a NFS in the brain meninges, detected by using polarized light microscopy, that provides space for a putative primo vessel, not a blood vessel.

  14. A Unified Framework for Creating Domain Dependent Polarity Lexicons from User Generated Reviews.

    Directory of Open Access Journals (Sweden)

    Muhammad Zubair Asghar

    Full Text Available The exponential increase in the explosion of Web-based user generated reviews has resulted in the emergence of Opinion Mining (OM applications for analyzing the users' opinions toward products, services, and policies. The polarity lexicons often play a pivotal role in the OM, indicating the positivity and negativity of a term along with the numeric score. However, the commonly available domain independent lexicons are not an optimal choice for all of the domains within the OM applications. The aforementioned is due to the fact that the polarity of a term changes from one domain to other and such lexicons do not contain the correct polarity of a term for every domain. In this work, we focus on the problem of adapting a domain dependent polarity lexicon from set of labeled user reviews and domain independent lexicon to propose a unified learning framework based on the information theory concepts that can assign the terms with correct polarity (+ive, -ive scores. The benchmarking on three datasets (car, hotel, and drug reviews shows that our approach improves the performance of the polarity classification by achieving higher accuracy. Moreover, using the derived domain dependent lexicon changed the polarity of terms, and the experimental results show that our approach is more effective than the base line methods.

  15. Analysis of polarization offsets observed for temperature-graded ferroelectric materials

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hui, E-mail:; Cheng, Taimin; Zheng, Hanlei; Zhang, Xinxin


    A transverse Ising model in the framework of the mean field approximation is developed to analyze the polarization offsets phenomena in temperature-graded ferroelectric materials. A function of two-spin exchange interaction strength has been introduced to describe the ferroelectric distortion due to the distribution of temperature gradients in materials. Comparisons of the computational results with the experimental data reveal some fundamental factors in the formation of polarization offsets. It is shown that ferroelectric distortion has influenced much on polarization offsets in temperature-graded ferroelectric materials. When quantum fluctuation effect as well as ferroelectric distortion is considered, we have successfully reproduced the experimental observations qualitatively, especially for the indistinguishable polarization offsets from the background at small temperature gradients, which were not successfully reproduced in prior theoretical studies. - Highlights: • A transverse Ising model is developed to analyze the polarization offsets phenomena in temperature-graded ferroelectrics. • A function of two-spin exchange interaction strength has been introduced to describe the ferroelectric distortion. • The experimental observations have been successfully reproduced qualitatively. • Ferroelectric distortion and quantum fluctuation effect are the two important factors to influence the polarization offsets.

  16. Twist-3 Effects in Polarized Photon Structure (United States)

    Baba, Hideshi; Sasaki, Ken; Uematsu, Tsuneo

    The polarized photon structure is described by two spin structure functions g1γ and g2γ which can be studied in the future polarized ep or e+e- colliders. Here we investigate the QCD twist-3 effects in g2γ to the leading order in QCD.

  17. Can polar bear hairs absorb environmental energy?

    Directory of Open Access Journals (Sweden)

    He Ji-Huan


    Full Text Available A polar bear (Ursus maritimus has superior ability to survive in harsh Arctic regions, why does the animal have such an excellent thermal protection? The present paper finds that the unique labyrinth cavity structure of the polar bear hair plays an important role. The hair can not only prevent body temperature loss but can also absorb energy from the environment.

  18. Ellipsometry with randomly varying polarization states

    NARCIS (Netherlands)

    Liu, Fenz; Lee, Christopher James; Chen, Juequan; Chen, J.; Louis, Eric; van der Slot, Petrus J.M.; Boller, Klaus J.; Bijkerk, Frederik


    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

  19. Ellipsometry with an undetermined polarization state

    NARCIS (Netherlands)

    Liu, Fei; Lee, Christopher James; Chen, Juequan; Louis, Eric; van der Slot, Petrus J.M.; Boller, Klaus J.; Bijkerk, Frederik


    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 eld. It is shown that light, passed through a randomly varying birefringent material has a well-dened orbit on the Poincare

  20. Ellipsometry with an undetermined polarization state

    NARCIS (Netherlands)

    Lui, F.; Lee, Christopher James; Chen, J.; Chen, Juequan; Louis, Eric; van der Slot, Petrus J.M.; Boller, Klaus J.; Bijkerk, Frederik


    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 Poincare

  1. Ellipsometry with random varying polarization state

    NARCIS (Netherlands)

    Liu, Fenz; van Albada, B.; Lee, c; Bijkerk, Frederik


    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

  2. Apico-basal polarity complex and cancer

    Indian Academy of Sciences (India)

    Loss of cell polarity is a hallmark for carcinoma, and its underlying molecular mechanism is beginning to emerge from studies on model organisms and cancer cell lines. Moreover, deregulated expression of apico-basal polarity complex components has been reported in human tumours. In this review, we provide an ...

  3. Diffractive Optics of Anisotropic Polarization Gratings

    NARCIS (Netherlands)

    Xu, M.


    Diffraction gratings are being used to manipulate light in many different applications, such as in flat panel display systems, modern lighting systems, and optical recording. Diffraction gratings can be made polarization selective due to form birefringence. An alternative approach to polarization

  4. Polarization Spectra of Extrasolar Giant Planets

    NARCIS (Netherlands)

    Stam, D.M.


    We present simulated spectra of the flux and degree of polarization of starlight that is reflected by extrasolar giant planets (EGPs). In particular the polarization depends strongly on the structure of the planetary atmosphere, and appears to be a valuable tool for the characterization of EGPs.

  5. Microwave dispersion of some polar liquids

    NARCIS (Netherlands)

    Poley, J.P.


    The chief purpose of the present investigation is the measurement and analysis of the microwave dispersion of some polar liquids. An outline of the problem and a historical survey of experimental work on the dielectric behaviour of polar liquids are given in Chapter I. A number of theoretical

  6. The First Polarization Maps from the GMRT

    Indian Academy of Sciences (India)


    Jan 27, 2016 ... We present the first set of polarimetric images made with the GMRT. We find that the instrumental polarization leakage at the GMRT varies with frequency. It is possible to calibrate these terms to better than 1% accuracy, making it feasible to study sources that are polarized at the few per cent level.

  7. Instrumentation to handle thermal polarized neutron beams

    NARCIS (Netherlands)

    Kraan, W.H.


    In this thesis we investigate devices needed to handle the polarization of thermal neutron beams: Ï/2-flippers (to start/stop Larmor precession) and Ï-flippers (to reverse polarization/precession direction) and illustrate how these devices are used to investigate the properties of matter and of the

  8. A broadband, circular-polarization selective surface (United States)

    Momeni Hasan Abadi, Seyed Mohamad Amin; Behdad, Nader


    We introduce a new technique for designing wideband circular-polarization selective surfaces (CPSSs) based on anisotropic miniaturized element frequency selective surfaces. The proposed structure is a combination of two linear-to-circular polarization converters sandwiching a linear polarizer. This CPSS consists of a number of metallic layers separated from each other by thin dielectric substrates. The metallic layers are in the form of two-dimensional arrays of subwavelength capacitive patches and inductive wire grids with asymmetric dimensions and a wire grid polarizer with sub-wavelength period. The proposed device is designed to offer a wideband circular-polarization selection capability allowing waves with left-hand circular polarization to pass through while rejecting those having right-hand circular polarization. A synthesis procedure is developed that can be used to design the proposed CPSS based on its desired band of operation. Using this procedure, a prototype of the proposed CPSS operating in the 12-18 GHz is designed. Full-wave electromagnetic simulations are used to predict the response of this structure. These simulation results confirm the validity of the proposed design concept and synthesis procedure and show that proposed CPSS operates within a fractional bandwidth of 40% with a co-polarization transmission discrimination of more than 15 dB. Furthermore, the proposed design is shown to be capable of providing an extremely wide field of view of ±60°.

  9. Polar and Alpine Microbiology - Earth's Cryobiosphere

    Czech Academy of Sciences Publication Activity Database

    Elster, Josef; Margesin, R.; Wagner, D.; Häggblom, M.


    Roč. 93, č. 1 (2017), s. 1-4, č. článku fiw221. ISSN 0168-6496 Institutional support: RVO:67985939 Keywords : diversity * Polar regions * Polar Microbiology Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 3.720, year: 2016

  10. Coronavirus infection of polarized epithelial cells

    NARCIS (Netherlands)

    Rossen, J W; Horzinek, M C; Rottier, P J


    Epithelial cells are the first host cells to be infected by incoming c oronaviruses. Recent observations in vitro show that coronaviruses are released from a specific side of these polarized cells, and this polarized release might be important for the spread of the infection in vivo. Mechanisms for

  11. Symmetry breaking signaling mechanisms during cell polarization

    NARCIS (Netherlands)

    Bruurs, LJM|info:eu-repo/dai/nl/413640779


    Breaking of cellular symmetry in order to establish an apico-basal polarity axis initiates de novo formation of cell polarity. However, symmetry breaking provides a formidable challenge from a signaling perspective, because by definition no spatial cues are present to instruct axis establishment.

  12. Polarization and preference for judgmental labels

    NARCIS (Netherlands)

    van der Pligt, J.; van Dijk, J.A.


    Studied how value connotations of the response language affect the relationship between judges' attitudes and polarization of judgment. In Exp I, 105 Dutch military conscripts rated 28 statements concerning drug use on 2 types of rating scales. Results indicate that Ss showed more polarization on

  13. Analyzing the Control Structure of PEPA

    DEFF Research Database (Denmark)

    Yang, Fan; Nielson, Hanne Riis

    to PEPA programs, the approximating result is very precise. Based on the analysis, we also develop algorithms for validating the deadlock property of PEPA programs. The techniques have been implemented in a tool which is able to analyze processes with a control structure that more than one thousand states....

  14. Construction of an Ion Energy Analyzer (United States)

    Little, Steven; Bellan, Paul


    An ion energy analyzer is being constructed and will be used to observe energetic ions emitted by the solar prominence simulation experiment at Caltech. The analyzer contains three stacked grids that are mounted on modular frames from Kimball Physics (eV Parts) followed by a collector plate. The first grid is negatively biased to repel electrons. The second grid is positively biased (discriminator grid) and is varied to filter the velocity distribution and give information about ion energy. The third grid is negatively biased relative to the collector to suppress secondary electrons resulting from ions striking the collector. The collector plate is also negatively biased and the ion flux impinging on it is measured. The electroformed mesh grid has spacings of the order of the Debye length. A bake-out heating element is also incorporated by using small molybdenum wire that can be resistively heated. The entire analyzer is designed for ease of assembly/disassembly and is mounted on a soft, copper tube that can be bent to point in different directions. The analyzer will be located about 1 meter from the main plasma and has a diameter of 3 cm and a length of 2 cm.

  15. 40 CFR 90.313 - Analyzers required. (United States)


    ... of the exhaust gas at the sample probe is below 190 °C, the temperature of the valves, pipe work, and... temperature of the exhaust gas at the sample probe is above 190 °C, the temperature of the valves, pipe work... the HFID analyzer, the detector, oven, and sample-handling components within the oven must be suitable...

  16. Graphic method for analyzing common path interferometers

    DEFF Research Database (Denmark)

    Glückstad, J.


    Common path interferometers are widely used for visualizing phase disturbances and fluid flows. They are attractive because of the inherent simplicity and robustness in the setup. A graphic method will be presented for analyzing and optimizing filter parameters in common path interferometers....

  17. Analyzing the Information Economy: Tools and Techniques. (United States)

    Robinson, Sherman


    Examines methodologies underlying studies which measure the information economy and considers their applicability and limitations for analyzing policy issues concerning libraries and library networks. Two studies provide major focus for discussion: Porat's "The Information Economy: Definition and Measurement" and Machlup's…

  18. Thermal and Evolved-Gas Analyzer Illustration (United States)


    This is a computer-aided drawing of the Thermal and Evolved-Gas Analyzer, or TEGA, on NASA's Phoenix Mars Lander. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  19. Analyzing and Interpreting Research in Health Education ...

    African Journals Online (AJOL)

    While qualitative research is used when little or nothing is known about the subject, quantitative research is required when there are quantifiable variables to be measured. By implication, health education research is based on phenomenological, ethnographical and/or grounded theoretical approaches that are analyzable ...

  20. Total Cost Management: Analyzing Operational Support Costs. (United States)

    Jenny, Hans J.


    Total cost management, an innovation useful in higher education, is best implemented in the institution's support services. Total cost management is the practice of analyzing and improving an institution's financial and qualitative performance when producing a particular product or service, paying attention to the complete work process and all…