WorldWideScience

Sample records for polarity controlling device

  1. PolarTrack: Optical Outside-In Device Tracking that Exploits Display Polarization

    DEFF Research Database (Denmark)

    Rädle, Roman; Jetter, Hans-Christian; Fischer, Jonathan

    2018-01-01

    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....... The periodic blinking results from the physical characteristics of current displays, which shine polarized light either through an LC overlay to produce images or through a polarizer to reduce light reflections on OLED displays. PolarTrack runs a simple detection algorithm on the camera feed to segment...... displays and track their locations and orientations, which makes PolarTrack particularly suitable as a tracking system for cross-device interaction with mobile devices. Our evaluation of PolarTrack's tracking quality and comparison with state-of-the-art camera-based multi-device tracking showed a better...

  2. Interferometric polarization control

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  3. Polarization-controlled asymmetric excitation of surface plasmons

    KAUST Repository

    Xu, Quan

    2017-08-28

    Free-space light can be coupled into propagating surface waves at a metal–dielectric interface, known as surface plasmons (SPs). This process has traditionally faced challenges in preserving the incident polarization information and controlling the directionality of the excited SPs. The recently reported polarization-controlled asymmetric excitation of SPs in metasurfaces has attracted much attention for its promise in developing innovative plasmonic devices. However, the unit elements in these works were purposely designed in certain orthogonal polarizations, i.e., linear or circular polarizations, resulting in limited two-level polarization controllability. Here, we introduce a coupled-mode theory to overcome this limit. We demonstrated theoretically and experimentally that, by utilizing the coupling effect between a pair of split-ring-shaped slit resonators, exotic asymmetric excitation of SPs can be obtained under the x-, y-, left-handed circular, and right-handed circular polarization incidences, while the polarization information of the incident light can be preserved in the excited SPs. The versatility of the presented design scheme would offer opportunities for polarization sensing and polarization-controlled plasmonic devices.

  4. Scattering Fields Control by Metamaterial Device Based on Ultra-Broadband Polarization Converters

    Directory of Open Access Journals (Sweden)

    Si-Jia Li

    2016-12-01

    Full Text Available We proposed a novel ultra-broadband meta¬material screen with controlling the electromagnetic scat¬tering fields based on the three layers wideband polariza¬tion converter (TLW-PC. The unit cell of TLW-PC was composed of a three layers substrate loaded with double metallic split-rings structure and a metal ground plane. We observed that the polarization converter primarily per¬formed ultra-broadband cross polarization conversion from 5.71 GHz to 14.91 GHz. Furthermore, a metamaterial screen, which contributed to the low scattering charac¬teristics, had been exploited with the orthogonal array based on TLW-PC. The near scattering electronic fields are controlled due to the change of phase and amplitude for incident wave. The metamaterial screen significantly exhibited low scattering characteristics from 5.81 GHz to 15.06 GHz. To demonstrate design, a metamaterial device easily implemented by the common printed circuit board method has been fabricated and measured. Experimental results agreed well with the simulated results.

  5. High-efficiency terahertz polarization devices based on the dielectric metasurface

    Science.gov (United States)

    Zhou, Jian; Wang, JingJing; Guo, Kai; Shen, Fei; Zhou, Qingfeng; Zhiping yin; Guo, Zhongyi

    2018-02-01

    Metasurfaces are composed of the subwavelength structures, which can be used to manipulate the amplitude, phase, and polarization of incident electromagnetic waves efficiently. Here, we propose a novel type of dielectric metasurface based on crystal Si for realizing to manipulate the terahertz wave, in which by varying the geometric sizes of the Si micro-bricks, the transmitting phase of the terahertz wave can almost span over the entire 2π range for both of the x-polarization and y-polarization simultaneously, while keeping the similarly high-transmission amplitudes (over 90%). At the frequency of 1.0 THz, we have successfully designed a series of controllable THz devices, such as the polarization-dependent beam splitter, polarization-independent beam deflector and the focusing lenses based on the designed metasurfaces. Our designs are easy to fabricate and can be promising in developing high-efficiency THz functional devices.

  6. Polarity in GaN and ZnO: Theory, measurement, growth, and devices

    Science.gov (United States)

    Zúñiga-Pérez, Jesús; Consonni, Vincent; Lymperakis, Liverios; Kong, Xiang; Trampert, Achim; Fernández-Garrido, Sergio; Brandt, Oliver; Renevier, Hubert; Keller, Stacia; Hestroffer, Karine; Wagner, Markus R.; Reparaz, Juan Sebastián; Akyol, Fatih; Rajan, Siddharth; Rennesson, Stéphanie; Palacios, Tomás; Feuillet, Guy

    2016-12-01

    The polar nature of the wurtzite crystalline structure of GaN and ZnO results in the existence of a spontaneous electric polarization within these materials and their associated alloys (Ga,Al,In)N and (Zn,Mg,Cd)O. The polarity has also important consequences on the stability of the different crystallographic surfaces, and this becomes especially important when considering epitaxial growth. Furthermore, the internal polarization fields may adversely affect the properties of optoelectronic devices but is also used as a potential advantage for advanced electronic devices. In this article, polarity-related issues in GaN and ZnO are reviewed, going from theoretical considerations to electronic and optoelectronic devices, through thin film, and nanostructure growth. The necessary theoretical background is first introduced and the stability of the cation and anion polarity surfaces is discussed. For assessing the polarity, one has to make use of specific characterization methods, which are described in detail. Subsequently, the nucleation and growth mechanisms of thin films and nanostructures, including nanowires, are presented, reviewing the specific growth conditions that allow controlling the polarity of such objects. Eventually, the demonstrated and/or expected effects of polarity on the properties and performances of optoelectronic and electronic devices are reported. The present review is intended to yield an in-depth view of some of the hot topics related to polarity in GaN and ZnO, a fast growing subject over the last decade.

  7. New developments on the generation of arbitrary polarized radiation from insertion devices

    International Nuclear Information System (INIS)

    Elleaume, P.

    1991-01-01

    The complete description of the polarization of a beam of radiation is described in terms of the total energy and three polarization rates. The polarization characteristics from conventional undulators and wigglers is recalled. A presentation is made of some new insertion devices that were proposed and/or built to generate circular polarization and more generally to improve the control of polarization. They are the asymmetric and elliptical wigglers and the helical and crossed undulators

  8. Integrated devices for quantum information and quantum simulation with polarization encoded qubits

    Science.gov (United States)

    Sansoni, Linda; Sciarrino, Fabio; Mataloni, Paolo; Crespi, Andrea; Ramponi, Roberta; Osellame, Roberto

    2012-06-01

    The ability to manipulate quantum states of light by integrated devices may open new perspectives both for fundamental tests of quantum mechanics and for novel technological applications. The technology for handling polarization-encoded qubits, the most commonly adopted approach, was still missing in quantum optical circuits until the ultrafast laser writing (ULW) technique was adopted for the first time to realize integrated devices able to support and manipulate polarization encoded qubits.1 Thanks to this method, polarization dependent and independent devices can be realized. In particular the maintenance of polarization entanglement was demonstrated in a balanced polarization independent integrated beam splitter1 and an integrated CNOT gate for polarization qubits was realized and carachterized.2 We also exploited integrated optics for quantum simulation tasks: by adopting the ULW technique an integrated quantum walk circuit was realized3 and, for the first time, we investigate how the particle statistics, either bosonic or fermionic, influences a two-particle discrete quantum walk. Such experiment has been realized by adopting two-photon entangled states and an array of integrated symmetric directional couplers. The polarization entanglement was exploited to simulate the bunching-antibunching feature of non interacting bosons and fermions. To this scope a novel three-dimensional geometry for the waveguide circuit is introduced, which allows accurate polarization independent behaviour, maintaining a remarkable control on both phase and balancement of the directional couplers.

  9. Electromagnetic cloaking devices for TE and TM polarizations

    International Nuclear Information System (INIS)

    Bilotti, Filiberto; Tricarico, Simone; Vegni, Lucio

    2008-01-01

    In this paper, we present the design of an electromagnetic cloaking device working for both transverse electric (TE) and transverse magnetic (TM) polarizations. The theoretical approach to cloaking used here is inspired by the one presented by Alu and Engheta (2005 Phys. Rev. E 72 016623) for TM polarization. The case of TE polarization is firstly considered and, then, an actual inclusion-based cloak for TE polarization is also designed. In such a case, the cloak is made of a mu-near-zero (MNZ) metamaterial, as the dual counterpart of the epsilon-near-zero (ENZ) material that can be used for purely dielectric objects. The operation and the robustness of the cloaking device for the TE polarization is deeply investigated through a complete set of full-wave numerical simulations. Finally, the design and an application of a cloak operating for both TE and TM polarizations employing both magnetic inclusions and the parallel plate medium already used by Silveirinha et al (Phys. Rev. E 75 036603) are presented.

  10. Controlling vortex chirality and polarity by geometry in magnetic nanodots

    OpenAIRE

    Agramunt Puig, Sebastià

    2014-01-01

    The independent control of both vortex chirality and polarity is a significant challenge in magnetic devices based on nano-sized magnetic vortex structures. By micromagnetic simulations here, we show that in soft ferromagnetic nanodots with an adequate modulated thickness, the desired combination of chirality and polarity can be achieved just by changing the direction of the in-plane applied magnetic field. Despite the complex behavior, the vortex chirality and polarity control can be summari...

  11. Polarizing beam-splitter device at a pulsed neutron source

    International Nuclear Information System (INIS)

    Itoh, Shinichi; Takeda, Masayasu.

    1996-01-01

    A polarizing beam-splitter device was designed using Fe/Si supermirrors in order to obtain two polarized neutron beam lines, from one unpolarized neutron beam line, with a practical beam size for investigating the properties of condensed matter. This device was mounted after a guide tube at a pulsed neutron source, and its performance was investigated. (author)

  12. Design of a device for sky light polarization measurements.

    Science.gov (United States)

    Wang, Yujie; Hu, Xiaoping; Lian, Junxiang; Zhang, Lilian; Xian, Zhiwen; Ma, Tao

    2014-08-14

    Sky polarization patterns can be used both as indicators of atmospheric turbidity and as a sun compass for navigation. The objective of this study is to improve the precision of sky light polarization measurements by optimal design of the device used. The central part of the system is composed of a Charge Coupled Device (CCD) camera; a fish-eye lens and a linear polarizer. Algorithms for estimating parameters of the polarized light based on three images are derived and the optimal alignments of the polarizer are analyzed. The least-squares estimation is introduced for sky light polarization pattern measurement. The polarization patterns of sky light are obtained using the designed system and they follow almost the same patterns of the single-scattering Rayleigh model. Deviations of polarization angles between observation and the theory are analyzed. The largest deviations occur near the sun and anti-sun directions. Ninety percent of the deviations are less than 5° and 40% percent of them are less than 1°. The deviations decrease evidently as the degree of polarization increases. It also shows that the polarization pattern of the cloudy sky is almost identical as in the blue sky.

  13. Vector wave diffraction pattern of slits masked by polarizing devices

    Indian Academy of Sciences (India)

    This calls for a systematic study of diffraction properties of different apertures using polarization-sensitive devices. In the present paper, we have studied the Fraunhofer diffraction pattern of slits masked by different kinds of polarizing devices which introduce a phase difference between the two orthogonal components of the ...

  14. In situ scanning tunneling microscope tip treatment device for spin polarization imaging

    Science.gov (United States)

    Li, An-Ping [Oak Ridge, TN; Jianxing, Ma [Oak Ridge, TN; Shen, Jian [Knoxville, TN

    2008-04-22

    A tip treatment device for use in an ultrahigh vacuum in situ scanning tunneling microscope (STM). The device provides spin polarization functionality to new or existing variable temperature STM systems. The tip treatment device readily converts a conventional STM to a spin-polarized tip, and thereby converts a standard STM system into a spin-polarized STM system. The tip treatment device also has functions of tip cleaning and tip flashing a STM tip to high temperature (>2000.degree. C.) in an extremely localized fashion. Tip coating functions can also be carried out, providing the tip sharp end with monolayers of coating materials including magnetic films. The device is also fully compatible with ultrahigh vacuum sample transfer setups.

  15. Principal State Analysis for a Compact in-Line Fiber Polarization Controller

    International Nuclear Information System (INIS)

    Li Zheng-Yong; Wu Chong-Qing; Wang Zhi-Hao; Qin Tao; Wang Yi-Xu

    2013-01-01

    A compact in-line fiber-based polarization controller (FPC) made of a rotatable fiber squeezer is investigated in detail with the Mueller matrix model established based on the generalized principal state of polarization (PSP). The PSP caused by the fiber squeezing is in the equator plane, which turns around S 3 axis on the Poincaré sphere when rotating the squeezer. Subsequently, a programmable polarization control method is proposed to realize the polarization conversion between arbitrary polarization states, in which only two parameters of phase shift and rotation angle need to be controlled. This type of FPC, which has a highly compact structure, lower insertion loss, and can be directly embedded into any fiber devices without any extra delay, will be an ideal PC for high-speed optical communication and all-optical signal processing

  16. A survey of synchrotron radiation devices producing circular or variable polarization

    International Nuclear Information System (INIS)

    Kim, K.J.

    1990-01-01

    This paper reviews the properties and operating principles of the new types of synchrotron radiation devices that produce circular polarization, or polarization that can be modulated in arbitrary fashion

  17. Integrated-optics heralded controlled-NOT gate for polarization-encoded qubits

    Science.gov (United States)

    Zeuner, Jonas; Sharma, Aditya N.; Tillmann, Max; Heilmann, René; Gräfe, Markus; Moqanaki, Amir; Szameit, Alexander; Walther, Philip

    2018-03-01

    Recent progress in integrated-optics technology has made photonics a promising platform for quantum networks and quantum computation protocols. Integrated optical circuits are characterized by small device footprints and unrivalled intrinsic interferometric stability. Here, we take advantage of femtosecond-laser-written waveguides' ability to process polarization-encoded qubits and present an implementation of a heralded controlled-NOT gate on chip. We evaluate the gate performance in the computational basis and a superposition basis, showing that the gate can create polarization entanglement between two photons. Transmission through the integrated device is optimized using thermally expanded core fibers and adiabatically reduced mode-field diameters at the waveguide facets. This demonstration underlines the feasibility of integrated quantum gates for all-optical quantum networks and quantum repeaters.

  18. Electrically switchable photonic liquid crystal devices for routing of a polarized light wave

    Science.gov (United States)

    Rushnova, Irina I.; Melnikova, Elena A.; Tolstik, Alexei L.; Muravsky, Alexander A.

    2018-04-01

    The new mode of LC alignment based on photoalignment AtA-2 azo dye where the refractive interface between orthogonal orientations of the LC director exists without voltage and disappeared or changed with critical voltage has been proposed. The technology to fabricate electrically controlled liquid crystal elements for spatial separation and switching of linearly polarized light beams on the basis of the total internal reflection effect has been significantly improved. Its distinctive feature is the application of a composite alignment material comprising two sublayers of Nylon-6 and AtA-2 photoalignment azo dye offering patterned liquid crystal director orientation with high alignment quality value q = 0 . 998. The fabricated electrically controlled spatially structured liquid crystal devices enable implementation of propagation directions separation for orthogonally polarized light beams and their switching with minimal crosstalk.

  19. Polarization-dependent optics using gauge-field metamaterials

    International Nuclear Information System (INIS)

    Liu, Fu; Xiao, Shiyi; Li, Jensen; Wang, Saisai; Hang, Zhi Hong

    2015-01-01

    We show that effective gauge field for photons with polarization-split dispersion surfaces, being realized using uniaxial metamaterials, can be used for polarization control with unique opportunities. The metamaterials with the proposed gauge field correspond to a special choice of eigenpolarizations on the Poincaré sphere as pseudo-spins, in contrary to those from either conventional birefringent crystals or optical active media. It gives rise to all-angle polarization control and a generic route to manipulate photon trajectories or polarizations in the pseudo-spin domain. As demonstrations, we show beam splitting (birefringent polarizer), all-angle polarization control, unidirectional polarization filter, and interferometer as various polarization control devices in the pseudo-spin domain. We expect that more polarization-dependent devices can be designed under the same framework

  20. Polarity Control in Group-III Nitrides beyond Pragmatism

    Science.gov (United States)

    Mohn, Stefan; Stolyarchuk, Natalia; Markurt, Toni; Kirste, Ronny; Hoffmann, Marc P.; Collazo, Ramón; Courville, Aimeric; Di Felice, Rosa; Sitar, Zlatko; Vennéguès, Philippe; Albrecht, Martin

    2016-05-01

    Controlling the polarity of polar semiconductors on nonpolar substrates offers a wealth of device concepts in the form of heteropolar junctions. A key to realize such structures is an appropriate buffer-layer design that, in the past, has been developed by empiricism. GaN or ZnO on sapphire are prominent examples for that. Understanding the basic processes that mediate polarity, however, is still an unsolved problem. In this work, we study the structure of buffer layers for group-III nitrides on sapphire by transmission electron microscopy as an example. We show that it is the conversion of the sapphire surface into a rhombohedral aluminum-oxynitride layer that converts the initial N-polar surface to Al polarity. With the various AlxOyNz phases of the pseudobinary Al2O3 -AlN system and their tolerance against intrinsic defects, typical for oxides, a smooth transition between the octahedrally coordinated Al in the sapphire and the tetrahedrally coordinated Al in AlN becomes feasible. Based on these results, we discuss the consequences for achieving either polarity and shed light on widely applied concepts in the field of group-III nitrides like nitridation and low-temperature buffer layers.

  1. Performance Analysis of Dual-Polarized Massive MIMO System with Human-Care IoT Devices for Cellular Networks

    Directory of Open Access Journals (Sweden)

    Jun-Ki Hong

    2018-01-01

    Full Text Available The performance analysis of the dual-polarized massive multiple-input multiple-output (MIMO system with Internet of things (IoT devices is studied when outdoor human-care IoT devices are connected to a cellular network via a dual-polarized massive MIMO system. The research background of the performance analysis of dual-polarized massive MIMO system with IoT devices is that recently the data usage of outdoor human-care IoT devices has increased. Therefore, the outdoor human-care IoT devices are necessary to connect with 5G cellular networks which can expect 1000 times higher performance compared with 4G cellular networks. Moreover, in order to guarantee the safety of the patient for emergency cases, a human-care Iot device must be connected to cellular networks which offer more stable communication for outdoors compared to short-range communication technologies such as Wi-Fi, Zigbee, and Bluetooth. To analyze the performance of the dual-polarized massive MIMO system for human-care IoT devices, a dual-polarized MIMO spatial channel model (SCM is proposed which considers depolarization effect between the dual-polarized transmit-antennas and the receive-antennas. The simulation results show that the performance of the dual-polarized massive MIMO system is improved about 16% to 92% for 20 to 150 IoT devices compared to conventional single-polarized massive MIMO system for identical size of the transmit array.

  2. Development of a LabVIEW-based surface with innovative controls for the control system of the spin-polarized electron test source Photo-CATCH

    Energy Technology Data Exchange (ETDEWEB)

    Roesch, Heidi Ayse; Enders, Joachim; Espig, Martin; Fritzsche, Yuliya; Wagner, Markus [TU Darmstadt, Institut fuer Kernphysik (Germany)

    2016-07-01

    Operations of the spin-polarized electron source of the S-DALINAC will be supported by a photo-cathode activation, test and cleaning system, Photo-CATCH. Besides cathode-performance studies, this teststand produces spin-polarized electron bunches from a GaAs photo-cathode that are then transported, manipulated, and characterized by devices in a low-energy beam line. To set and monitor the various components of the beamline, a control system was developed, based on the EPICS framework. As interfaces, LabVIEW was used in combination with a gamepad as a controlling device.

  3. Developments in Polarization and Energy Control of APPLE-II Undulators at Diamond Light Source

    Science.gov (United States)

    Longhi, E. C.; Bencok, P.; Dobrynin, A.; Rial, E. C. M.; Rose, A.; Steadman, P.; Thompson, C.; Thomson, A.; Wang, H.

    2013-03-01

    A pair of 2m long APPLE-II type undulators have been built for the I10 BLADE beamline at Diamond Light Source. These 48mm period devices have gap as well as four moveable phase axes which provide the possibility to produce the full range of elliptical polarizations as well as linear polarization tilted through a full 180deg. The mechanical layout chosen has a 'master and slave' arrangement of the phase axes on the top and bottom. This arrangement allows the use of symmetries to provide operational ease for both changing energy using only the master phase while keeping fixed linear horizontal or circular polarization, as well as changing linear polarization angle while keeping fixed energy [1]. The design allows very fast motion of the master phase arrays, without sacrifice of accuracy, allowing the possibility of mechanical polarization switching at 1Hz for dichroism experiments. We present the mechanical design features of these devices, as well as the results of magnetic measurements and shimming from before installation. Finally, we present the results of characterization of these devices by the beamline, including polarimetry, which has been done on the various modes of motion to control energy and polarization. These modes of operation have been available to users since 2011.

  4. Developments in Polarization and Energy Control of APPLE-II Undulators at Diamond Light Source

    International Nuclear Information System (INIS)

    Longhi, E C; Bencok, P; Dobrynin, A; Rial, E C M; Rose, A; Steadman, P; Thompson, C; Thomson, A; Wang, H

    2013-01-01

    A pair of 2m long APPLE-II type undulators have been built for the I10 BLADE beamline at Diamond Light Source. These 48mm period devices have gap as well as four moveable phase axes which provide the possibility to produce the full range of elliptical polarizations as well as linear polarization tilted through a full 180deg. The mechanical layout chosen has a 'master and slave' arrangement of the phase axes on the top and bottom. This arrangement allows the use of symmetries to provide operational ease for both changing energy using only the master phase while keeping fixed linear horizontal or circular polarization, as well as changing linear polarization angle while keeping fixed energy [1]. The design allows very fast motion of the master phase arrays, without sacrifice of accuracy, allowing the possibility of mechanical polarization switching at 1Hz for dichroism experiments. We present the mechanical design features of these devices, as well as the results of magnetic measurements and shimming from before installation. Finally, we present the results of characterization of these devices by the beamline, including polarimetry, which has been done on the various modes of motion to control energy and polarization. These modes of operation have been available to users since 2011.

  5. Coherent active polarization control without loss

    Science.gov (United States)

    Ye, Yuqian; Hay, Darrick; Shi, Zhimin

    2017-11-01

    We propose a lossless active polarization control mechanism utilizing an anisotropic dielectric medium with two coherent inputs. Using scattering matrix analysis, we derive analytically the required optical properties of the anisotropic medium that can behave as a switchable polarizing beam splitter. We also show that such a designed anisotropic medium can produce linearly polarized light at any azimuthal direction through coherent control of two inputs with a specific polarization state. Furthermore, we present a straightforward design-on-demand procedure of a subwavelength-thick metastructure that can possess the desired optical anisotropy at a flexible working wavelength. Our lossless coherent polarization control technique may lead to fast, broadband and integrated polarization control elements for applications in imaging, spectroscopy, and telecommunication.

  6. Research on generating various polarization-modes in polarized illumination system

    Science.gov (United States)

    Huang, Jinping; Lin, Wumei; Fan, Zhenjie

    2013-08-01

    With the increase of the numerical aperture (NA), the polarization of light affects the imaging quality of projection lens more significantly. On the contrary, according to the mask pattern, the resolution of projection lens can be improved by using the polarized illumination. That is to say, using the corresponding polarized beam (or polarization-mode) along with the off-axis illumination will improve the resolution and the imaging quality of the of projection lens. Therefore, the research on the generation of various polarization modes and its conversion methods become more and more important. In order to realize various polarization modes in polarized illumination system, after read a lot of references, we provide a way that fitting for the illumination system with the wavelength of 193nm.Six polarization-modes and a depolarized mode are probably considered. Wave-plate stack is used to generate linearly polarization-mode, which have a higher degree polarization. In order to generate X-Y and Y-X polarization mode, the equipment consisting of four sectors of λ/2 wave plate was used. We combined 16 sectors of λ/2 wave plate which have different orientations of the "slow" axis to generate radial and azimuthal polarization. Finally, a multi-polarization control device was designed. Using the kind of multi-polarization control device which applying this method could help to choose the polarization modes conveniently and flexibility for the illumination system.

  7. Coherent active polarization control without loss

    Directory of Open Access Journals (Sweden)

    Yuqian Ye

    2017-11-01

    Full Text Available We propose a lossless active polarization control mechanism utilizing an anisotropic dielectric medium with two coherent inputs. Using scattering matrix analysis, we derive analytically the required optical properties of the anisotropic medium that can behave as a switchable polarizing beam splitter. We also show that such a designed anisotropic medium can produce linearly polarized light at any azimuthal direction through coherent control of two inputs with a specific polarization state. Furthermore, we present a straightforward design-on-demand procedure of a subwavelength-thick metastructure that can possess the desired optical anisotropy at a flexible working wavelength. Our lossless coherent polarization control technique may lead to fast, broadband and integrated polarization control elements for applications in imaging, spectroscopy, and telecommunication.

  8. Parallel Polarization State Generation.

    Science.gov (United States)

    She, Alan; Capasso, Federico

    2016-05-17

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

  9. Development of accurate techniques for controlling polarization of a long wavelength neutron beam in very low magnetic fields. I

    International Nuclear Information System (INIS)

    Kawai, Takeshi; Ebisawa, Toru; Tasaki, Seiji; Akiyoshi, Tsunekazu; Eguchi, Yoshiaki; Hino, Masahiro; Achiwa, Norio.

    1995-01-01

    The purpose of our study is to develop accurate techniques for controlling polarization of a long wavelength neutron beam and to make a thin-film dynamical spin-flip device operated in magnetizing fields less than 100 gauss and in a shorter switching time up to 20 kHz. The device would work as a chopper for a polarized neutron beam and as a magnetic switching device for a multilayer neutron interferometer. We have started to develop multilayer polarizing mirrors functioning under magnetizing fields less than 100 gauss. The multilayers of Permalloy-Ge and Fe-Ge have been produced using the evaporation method under magnetizing fields of about 100 gauss parallel to the Si-wafer substrate surface. The hysteresis loop for in-plane magnetization of the multilayers were measured to discuss their feasibilities for the polarizing device functioning under very low magnetizing fields. The polarizing efficiencies of Fe-Ge and Permalloy-Ge multilayers were 95 % and 91 % with reflectivities of 50 % and 66 % respectively under magnetizing fields of 80 gauss. The report also discusses problems in applying these multilayer polarizing mirrors to ultracold neutrons. (author)

  10. Dispersion interferometer for controlled fusion devices

    International Nuclear Information System (INIS)

    Drachev, V.P.; Krasnikov, Yu.I.; Bagryansky, P.A.

    1992-01-01

    A common feature in interferometry is the presence of two independent optical channels. Since wave phase in a medium depends on the geometrical path, polarization and radiation frequency, respectively, one can distinguish three types of interferometric schemes when the channels are geometrically separated, or separation occurs in polarizations or radiation frequencies. We have developed a measurement scheme based on a dispersion interferometer (DI) for plasma diagnostics in the experiments on controlled fusion. DI optical channels have the same geometrical path and are separated in radiation frequency. Use of a common optical path causes the main advantage of the DI technique - low sensitivity to vibrations of optical elements. The use of the DI technique for diagnostics of a laser spark in air and of arc discharges has shown its essential advantages as compared to classical interferometers. Interest in the DI technique from the viewpoint of its application in controlled fusion devices is determined also generated by the possibility of developing a compact multichannel interferometer not requiring a vibration isolation structure. (author) 14 refs., 3 figs

  11. Reversible optical control of macroscopic polarization in ferroelectrics

    Science.gov (United States)

    Rubio-Marcos, Fernando; Ochoa, Diego A.; Del Campo, Adolfo; García, Miguel A.; Castro, Germán R.; Fernández, José F.; García, José E.

    2018-01-01

    The optical control of ferroic properties is a subject of fascination for the scientific community, because it involves the establishment of new paradigms for technology1-9. Domains and domain walls are known to have a great impact on the properties of ferroic materials1-24. Progress is currently being made in understanding the behaviour of the ferroelectric domain wall, especially regarding its dynamic control10-12,17,19. New research is being conducted to find effective methodologies capable of modulating ferroelectric domain motion for future electronics. However, the practical use of ferroelectric domain wall motion should be both stable and reversible (rewritable) and, in particular, be able to produce a macroscopic response that can be monitored easily12,17. Here, we show that it is possible to achieve a reversible optical change of ferroelectric domains configuration. This effect leads to the tuning of macroscopic polarization and its related properties by means of polarized light, a non-contact external control. Although this is only the first step, it nevertheless constitutes the most crucial one in the long and complex process of developing the next generation of photo-stimulated ferroelectric devices.

  12. Nuclear reactivity control using laser induced polarization

    International Nuclear Information System (INIS)

    Bowman, C.D.

    1990-01-01

    This patent describes a control element for reactivity control of a fission source provides an atomic density of 3 He in a control volume which is effective to control criticality as the 3 He is spin-polarized. Spin-polarization of the 3 He affects the cross section of the control volume for fission neutrons and hence, the reactivity. An irradiation source is directed within the 3 He for spin-polarizing the 3 He. An alkali-metal vapor may be included with the 3 He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with 3 He to spin-polarize the 3 He atoms

  13. Metallic metasurfaces for high efficient polarization conversion control in transmission mode.

    Science.gov (United States)

    Li, Tong; Hu, Xiaobin; Chen, Huamin; Zhao, Chen; Xu, Yun; Wei, Xin; Song, Guofeng

    2017-10-02

    A high efficient broadband polarization converter is an important component in integrated miniaturized optical systems, but its performances is often restricted by the material structures, metallic metasurfaces for polarization control in transmission mode never achieved efficiency above 0.5. Herein, we theoretically demonstrate that metallic metasurfaces constructed by thick cross-shaped particles can realize a high efficient polarization transformation over a broadband. We investigated the resonant properties of designed matesurfaces and found that the interaction between double FP cavity resonances and double bulk magnetic resonances is the main reason to generate a high transmissivity over a broadband. In addition, through using four resonances effect and tuning the anisotropic optical response, we realized a high efficient (> 0.85) quarter-wave plate at the wavelength range from 1175nm to 1310nm and a high efficient (> 0.9) half-wave plate at the wavelength range from 1130nm to 1230nm. The proposed polarization converters may have many potential applications in integrated polarization conversion devices and optical data storage systems.

  14. Process control device

    International Nuclear Information System (INIS)

    Hayashi, Toshifumi; Kobayashi, Hiroshi.

    1994-01-01

    A process control device comprises a memory device for memorizing a plant operation target, a plant state or a state of equipments related with each other as control data, a read-only memory device for storing programs, a plant instrumentation control device or other process control devices, an input/output device for performing input/output with an operator, and a processing device which conducts processing in accordance with the program and sends a control demand or a display demand to the input/output device. The program reads out control data relative to a predetermined operation target, compares and verify them with actual values to read out control data to be a practice premise condition which is further to be a practice premise condition if necessary, thereby automatically controlling the plant or requiring or displaying input. Practice presuming conditions for the operation target can be examined succesively in accordance with the program without constituting complicated logical figures and AND/OR graphs. (N.H.)

  15. Plasmonic Dimer Metamaterials and Metasurfaces for Polarization Control of Terahertz and Optical Waves

    DEFF Research Database (Denmark)

    Zhukovsky, Sergei; Zalkovskij, Maksim; Malureanu, Radu

    2013-01-01

    We explore the capabilities of planar metamaterials and metasurfaces to control and transform the polarization of electromagnetic radiation, and present a detailed covariant multipole theory of dimer-based metamaterials. We show that various optical properties, such as optical activity, elliptical...... dichroism or polarization conversion can be achieved in metamaterials made of simple shapes, such as nanorods, just by varying their geometrical arrangement. By virtue of the Babinet principle, the proposed theory is extended to inverted structures (membranes) where rods are replaced by slots. Such free......-standing “metasurface membranes” can act as thin-film spectrally sensitive polarization shapers for THz radiation. Proof-of-principle devices (a linear polarizer and a structure with giant optical activity) are fabricated and characterized. Experimental results coincide with those of full-wave numerical simulations...

  16. Predistortion control device and method, assembly including a predistortion control device

    NARCIS (Netherlands)

    Kokkeler, Andre B.J.

    2003-01-01

    A predistortion control device (1). The device has a first predistortion control input connectable to a power amplifier output (21); a second predistortion control input (11) connectable to a signal contact of a predistortion device; and a predistortion control output (12) connectable to a control

  17. Fabrication of advanced Bragg gratings with complex apodization profiles by use of the polarization control method

    DEFF Research Database (Denmark)

    Deyerl, Hans-Jürgen; Plougmann, Nikolai; Jensen, Jesper Bo Damm

    2004-01-01

    The polarization control method offers a flexible, robust, and low-cost route for the parallel fabrication of gratings with complex apodization profiles including several discrete phase shifts and chirp. The performance of several test gratings is evaluated in terms of their spectral response...... and compared with theoretical predictions. Short gratings with sidelobe-suppression levels in excess of 32 dB and transmission dips lower than 80 dB have been realized. Finally, most of the devices fabricated by the polarization control method show comparable quality to gratings manufactured by far more...

  18. Velocity barrier-controlled of spin-valley polarized transport in monolayer WSe2 junction

    Science.gov (United States)

    Qiu, Xuejun; Lv, Qiang; Cao, Zhenzhou

    2018-05-01

    In this work, we have theoretically investigated the influence of velocity barrier on the spin-valley polarized transport in monolayer (ML) WSe2 junction with a large spin-orbit coupling (SOC). Both the spin-valley resolved transmission probabilities and conductance are strong dependent on the velocity barrier, as the velocity barrier decreases to 0.06, a spin-valley polarization of exceeding 90% is observed, which is distinct from the ML MoS2 owing to incommensurable SOC. In addition, the spin-valley polarization is further increased above 95% in a ML WSe2 superlattice, in particular, it's found many extraordinary velocity barrier-dependent transport gaps for multiple barrier due to evanescent tunneling. Our results may open an avenue for the velocity barrier-controlled high-efficiency spin and valley polarizations in ML WSe2-based electronic devices.

  19. Control rod position control device

    International Nuclear Information System (INIS)

    Ubukata, Shinji.

    1997-01-01

    The present invention provides a control rod position control device which stores data such as of position signals and driving control rod instruction before and after occurrence of abnormality in control for the control rod position for controlling reactor power and utilized the data effectively for investigating the cause of abnormality. Namely, a plurality of individual control devices have an operation mismatching detection circuit for outputting signals when difference is caused between a driving instruction given to the control rod position control device and the control rod driving means and signals from a detection means for detecting an actual moving amount. A general control device collectively controls the individual control devices. In addition, there is also disposed a position storing circuit for storing position signals at least before and after the occurrence of the control rod operation mismatching. With such procedures, the cause of the abnormality can be determined based on the position signals before and after the occurrence of control rod mismatching operation stored in the position storing circuit. Accordingly, the abnormality cause can be determined to conduct restoration in an early stage. (I.S.)

  20. A bioartificial kidney device with polarized secretion of immune modulators.

    Science.gov (United States)

    Chevtchik, N V; Mihajlovic, M; Fedecostante, M; Bolhuis-Versteeg, L; Sastre Toraño, J; Masereeuw, R; Stamatialis, D

    2018-05-15

    The accumulation of protein-bound toxins in dialyzed patients is strongly associated with their high morbidity and mortality. The bioartificial kidney device (BAK), containing proximal tubule epithelial cells (PTEC) seeded on functionalized synthetic hollow fiber membranes (HFM), may be a powerful solution for the active removal of those metabolites. In an earlier study, we developed an upscaled BAK containing conditionally immortalized human PTEC (ciPTEC) with functional organic cationic transporter 2 (OCT2). Here, we first extended this development to a BAK device having cells with the organic anionic transporter 1 (OAT1), capable of removing anionic uremic wastes. We confirmed the quality of the ciPTEC monolayer by confocal microscopy and paracellular inulin-FITC leakage, as well as, by the active transport of anionic toxin, indoxyl sulfate (IS). Furthermore, we assessed the immune-safety of our system by measuring the production of relevant cytokines by the cells after lipopolysaccharide (LPS) stimulation. Upon LPS treatment, we observed a polarized secretion of pro-inflammatory cytokines by the cells: 10-fold higher in the extraluminal space, corresponding to the urine compartment, as compared to the intraluminal space, corresponding to the blood compartment. To the best of our knowledge, our work is the first to show this favorable cell polarization in a BAK upscaled device. This article is protected by copyright. All rights reserved.

  1. Fabrication of a Polarizing Neutron Supermirror and Development of its applied Devices

    International Nuclear Information System (INIS)

    Cho, Sang Jin; Ryu, Ji Myoungi; Kim, Sangwon

    2013-02-01

    Based on the project of neutron guide development, which started in 2005, KAERI has possessed the techniques such as supermirror coating, guide element assembly, guide alignment, special tool development and guide element assembly, guide alignment, special tool development and guide maintenance. With help of multilayer coating technique from supermirror fabrication, a project called 'Development of a Polarizing Supermirror and its applied devices' started early 2011. To begin with, most used coating materials were investigated, and for using polarized beam, G-TS located at CG1 beam line (Guide Test Station: Reflectometer) was modified with adding spin flipper, polarizer, analyzer and magnetic sample holder developed by KAERI. By studying crystallization and oxidation of the FeCo alloy to minimize the layer roughness and magnetization of a magnetic layer to determine minimal magnetic field, the neutron polarizing supermirrors have been developed, which show a average reflectivity of 90% and a polarization of 95% for M=2 and a average reflectivity of 80% and a polarization of 95% for M=2.6

  2. Material and device studies for the development of ultra-violet light emitting diodes (UV-LEDS) along polar, non-polar and semi-polar directions

    Science.gov (United States)

    Chandrasekaran, Ramya

    Over the past few years, significant effort was dedicated to the development of ultraviolet light emitting diodes (UV-LEDs) for a variety of applications. Such applications include chemical and biological detection, water purification and solid-state lighting. III-Nitride LEDs based on multiple quantum wells (MQWs) grown along the conventional [0001] (polar) direction suffer from the quantum confined Stark effect (QCSE), due to the existence of strong electric fields that arise from spontaneous and piezoelectric polarization. Thus, there is strong motivation to develop MQW-based III-nitride LED structures grown along non-polar and semi-polar directions. The goal of this dissertation is to develop UV-LEDs along the [0001] polar and [11 2¯ 0] non-polar directions by the method of Molecular Beam Epitaxy (MBE). The polar and non-polar LEDs were grown on the C-plane and R-plane sapphire substrates respectively. This work is a combination of materials science studies related to the nucleation, growth and n- and p-type doping of III-nitride films on these two substrates, as well as device studies related to fabrication and characterization of UV-LEDs. It was observed that the crystallographic orientation of the III-nitride films grown on R-plane sapphire depends strongly on the kinetic conditions of growth of the Aluminum Nitride (AIN) buffer. Specifically, growth of the AIN buffer under group III-rich conditions leads to nitride films having the (11 2¯ 0) non polar planes parallel to the sapphire surface, while growth of the buffer under nitrogen rich conditions leads to nitride films with the (11 2¯ 6) semi-polar planes parallel to the sapphire surface. The electron concentration and mobility for the films grown along the polar, non-polar and semi-polar directions were investigated. P-type doping of Gallium Nitride (GaN) films grown on the nonpolar (11 2¯ 0) plane do not suffer from polarity inversion and thus the material was doped p-type with a hole concentration

  3. Lateral polarity control of III-nitride thin film and application in GaN Schottky barrier diode

    Science.gov (United States)

    Li, Junmei; Guo, Wei; Sheikhi, Moheb; Li, Hongwei; Bo, Baoxue; Ye, Jichun

    2018-05-01

    N-polar and III-polar GaN and AlN epitaxial thin films grown side by side on single sapphire substrate was reported. Surface morphology, wet etching susceptibility and bi-axial strain conditions were investigated and the polarity control scheme was utilized in the fabrication of Schottky barrier diode where ohmic contact and Schottky contact were deposited on N-polar domains and Ga-polar domains, respectively. The influence of N-polarity on on-state resistivity and I–V characteristic was discussed, demonstrating that lateral polarity structure of GaN and AlN can be widely used in new designs of optoelectronic and electronic devices. Project partially supported by the National Key Research and Development Program of China (No. 2016YFB0400802), the National Natural Science Foundation of China (No. 61704176), and the Open project of Zhejiang Key Laboratory for Advanced Microelectronic Intelligent Systems and Applications (No. ZJUAMIS1704).

  4. DeviceNet-based device-level control in SSRF

    CERN Document Server

    Leng Yong Bin; Lu Cheng Meng; Miao Hai Feng; Liu Song Qiang; Shen Guo Bao

    2002-01-01

    The control system of Shanghai Synchrotron Radiation Facility is an EPICS-based distributed system. One of the key techniques to construct the system is the device-level control. The author describes the design and implementation of the DeviceNet-based device controller. A prototype of the device controller was tested in the experiments of magnet power supply and the result showed a precision of 3 x 10 sup - sup 5

  5. Ultra-thin, single-layer polarization rotator

    Directory of Open Access Journals (Sweden)

    T. V. Son

    2016-08-01

    Full Text Available We demonstrate light polarization control over a broad spectral range by a uniform layer of vanadium dioxide as it undergoes a phase transition from insulator to metal. Changes in refractive indices create unequal phase shifts on s- and p-polarization components of incident light, and rotation of linear polarization shows intensity modulation by a factor of 103 when transmitted through polarizers. This makes possible polarization rotation devices as thin as 50 nm that would be activated thermally, optically or electrically.

  6. Polarization preservation and control in a figure-8 ring

    Energy Technology Data Exchange (ETDEWEB)

    Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Morozov, Vasiliy [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Lin, Fanglei [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Kondratenko, A. M. [GOO Zaryad, Russkaya st., 41, Novosibirsk, 630058; Kondratenko, M. A. [GOO Zaryad, Russkaya st., 41, Novosibirsk, 630058; Filatov, Yuri [Joint Inst. for Nuclear Research (JINR), Dubna (Russian Federation); GOO Zaryad, Russkaya st., 41, Novosibirsk, 630058

    2016-02-01

    We present a complete scheme for managing the polarization of ion beams in Jefferson Lab's proposed Medium-energy Electron-Ion Collider (MEIC). It provides preservation of the ion polarization during all stages of beam acceleration and polarization control in the collider's experimental straights. We discuss characteristic features of the spin motion in accelerators with Siberian snakes and in accelerators of figure-8 shape. We propose 3D spin rotators for polarization control in the MEIC ion collider ring. We provide polarization calculations in the collider with the 3D rotator for deuteron and proton beams. The main polarization control features of the figure-8 design are summarized.

  7. Integrated control rod monitoring device

    International Nuclear Information System (INIS)

    Saito, Katsuhiro

    1997-01-01

    The present invention provides a device in which an entire control rod driving time measuring device and a control rod position support device in a reactor building and a central control chamber are integrated systematically to save hardwares such as a signal input/output device and signal cables between boards. Namely, (1) functions of the entire control rod driving time measuring device for monitoring control rods which control the reactor power and a control rod position indication device are integrated into one identical system. Then, the entire devices can be made compact by the integration of the functions. (2) The functions of the entire control rod driving time measuring device and the control rod position indication device are integrated in a central operation board and a board in the site. Then, the place for the installation of them can be used in common in any of the cases. (3) The functions of the entire control rod driving time measuring device and the control rod position indication device are integrated to one identical system to save hardware to be used. Then, signal input/output devices and drift branching panel boards in the site and the central operation board can be saved, and cables for connecting both of the boards is no more necessary. (I.S.)

  8. Transparent thin film polarizing and optical control systems

    Directory of Open Access Journals (Sweden)

    Nelson V. Tabiryan

    2011-06-01

    Full Text Available We show that a diffractive waveplate can be combined with a phase retardation film for fully converting light of arbitrary polarization state into a polarized light. Incorporating a photonic bandgap layer into a system of such polarizers that unify different polarization states in the input light into a single polarization state at its output, rather than absorbing or reflecting half of it, we developed and demonstrated a polarization-independent optical controller capable of switching between transmittive and reflective states. The transition between those states is smoothly controlled with low-voltage and low-power sources. Using versatile fabrication methods, this “universally polarizing optical controller” can be integrated into a thin package compatible with a variety of display, spatial light modulation, optical communication, imaging and other photonics systems.

  9. Development of a neutron-polarizing device based on a quadrupole magnet and its application to a focusing SANS instrument

    International Nuclear Information System (INIS)

    Oku, Takayuki

    2009-01-01

    We have investigated suitable magnetic field distribution to polarize neutrons based only on the electromagnetic interaction between a neutron magnetic moment and magnetic field, and found out a quadrupole field was the most suitable among simple multipole fields. Then we constructed a quadrupole magnet with a Halbach magnetic circuit as the neutron polarizing device. A cold neutron polarizing experiment of the quadrupole magnet was performed at the beamline C3-1-2-1 (NOP) of JRR-3 at JAEA. By passing through the aperture of the quadrupole magnet, positive and negative polarity neutrons are accelerated in opposite directions and spatially separated. Therefore, we extracted the one-spin component and analyzed its polarization degree. As a result very high neutron polarization degree P=0.9993±0.0025 was obtained. Then the quadrupole magnet was installed into the polarized neutron focusing geometry SANS instrument SANS-J-II of JRR-3. The instrument performance was enhanced by about 10 times compared with the case with the magnetic supermirror as the neutron polarizing device. The details are shown and discussed. (author)

  10. Polarization Control with Piezoelectric and LiNbO3 Transducers

    Science.gov (United States)

    Bradley, E.; Miles, E.; Loginov, B.; Vu, N.

    Several Polarization control transducers have appeared on the market, and now automated, endless polarization control systems using these transducers are becoming available. Unfortunately it is not entirely clear what benchmark performance tests a polarization control system must pass, and the polarization disturbances a system must handle are open to some debate. We present quantitative measurements of realistic polarization disturbances and two benchmark tests we have successfully used to evaluate the performance of an automated, endless polarization control system. We use these tests to compare the performance of a system using piezoelectric transducers to that of a system using LiNbO3 transducers.

  11. Polarization Converter with Controllable Birefringence Based on Hybrid All-Dielectric-Graphene Metasurface

    Science.gov (United States)

    Owiti, Edgar O.; Yang, Hanning; Liu, Peng; Ominde, Calvine F.; Sun, Xiudong

    2018-02-01

    Previous studies on hybrid dielectric-graphene metasurfaces have been used to implement induced transparency devices, while exhibiting high Q-factors based on trapped magnetic resonances. Typically, the transparency windows are single wavelength and less appropriate for polarization conversion structures. In this work, a quarter-wave plate based on a hybrid silicon-graphene metasurface with controllable birefringence is numerically designed. The phenomena of trapped magnetic mode resonance and high Q-factors are modulated by inserting graphene between silicon and silica. This results in a broader transmission wavelength in comparison to the all-dielectric structure without graphene. The birefringence tunability is based on the dimensions of silicon and the Fermi energy of graphene. Consequently, a linear-to-circular polarization conversion is achieved at a high degree of 96%, in the near-infrared. Moreover, the polarization state of the scattered light is switchable between right and left hand circular polarizations, based on an external gate biasing voltage. Unlike in plasmonic metasurfaces, these achievements demonstrate an efficient structure that is free from radiative and ohmic losses. Furthermore, the ultrathin thickness and the compactness of the structure are demonstrated as key components in realizing integrable and CMOS compatible photonic sensors.

  12. Polarization splitter and polarization rotator designs based on transformation optics.

    Science.gov (United States)

    Kwon, Do-Hoon; Werner, Douglas H

    2008-11-10

    The transformation optics technique is employed in this paper to design two optical devices - a two-dimensional polarization splitter and a three-dimensional polarization rotator for propagating beams. The polarization splitter translates the TM- and the TE-polarized components of an incident beam in opposite directions (i.e., shifted up or shifted down). The polarization rotator rotates the polarization state of an incoming beam by an arbitrary angle. Both optical devices are reflectionless at the entry and exit interfaces. Design details and full-wave simulation results are provided.

  13. The new polarizer devices at RESEDA

    International Nuclear Information System (INIS)

    Repper, J; Häußler, W; Ostermann, A; Kredler, L; Chacón, A; Böni, P

    2012-01-01

    In the neutron resonance spin echo method the information about sample dynamics is encoded in the neutron beam polarization measured in the analyzer-detector unit. Thus, the method is not applicable for sample systems and environments, which depolarize the neutron beam strongly. To over come this draw back a neutron analyzer directly before the sample position may be installed to perform MIEZE-I experiments. We compared the performance of a transmission polarizer and a solid-state bender at this position for the neutron resonance spin echo spectrometer RESEDA by Monte Carlo simulations. It turned out, that the polarization as well as the intensity transmitted to the sample position is more advantageous for the transmission polarizer as for the bender. In addition, we present measurements of the polarization and intensity performance of the transmission polarizer already installed at RESEDA to polarize the neutron beam coming from the reactor FRM II. The measurements are in good agreement with Monte Carlo simulations.

  14. Polarization-independent broadband meta-holograms via polarization-dependent nanoholes.

    Science.gov (United States)

    Zhang, Xiaohu; Li, Xiong; Jin, Jinjin; Pu, Mingbo; Ma, Xiaoliang; Luo, Jun; Guo, Yinghui; Wang, Changtao; Luo, Xiangang

    2018-05-17

    Composed of ultrathin metal or dielectric nanostructures, metasurfaces can manipulate the phase, amplitude and polarization of electromagnetic waves at a subwavelength scale, which is promising for flat optical devices. In general, metasurfaces composed of space-variant anisotropic units are sensitive to the incident polarization due to the inherent polarization dependent geometric phase. Here, we implement polarization-independent broadband metasurface holograms constructed by polarization-dependent anisotropic elliptical nanoholes by elaborate design of complex amplitude holograms. The fabricated meta-hologram exhibits a polarization insensitive feature with an acceptable image quality. We verify the feasibility of the design algorithm for three-dimensional (3D) meta-holograms with simulation and the feasibility for two-dimensional (2D) meta-holograms is experimentally demonstrated at a broadband wavelength range from 405 nm to 632.8 nm. The effective polarization-independent broadband complex wavefront control with anisotropic elliptical nanoholes proposed in this paper greatly promotes the practical applications of the metasurface in technologies associated with wavefront manipulation, such as flat lens, colorful holographic displays and optical storage.

  15. Polarity control of GaN epitaxial films grown on LiGaO2(001) substrates and its mechanism.

    Science.gov (United States)

    Zheng, Yulin; Wang, Wenliang; Li, Xiaochan; Li, Yuan; Huang, Liegen; Li, Guoqiang

    2017-08-16

    The polarity of GaN epitaxial films grown on LiGaO 2 (001) substrates by pulsed laser deposition has been well controlled. It is experimentally proved that the GaN epitaxial films grown on nitrided LiGaO 2 (001) substrates reveal Ga-polarity, while the GaN epitaxial films grown on non-nitrided LiGaO 2 (001) substrates show N-polarity. The growth mechanisms for these two cases are systematically studied by first-principles calculations based on density functional theory. Theoretical calculation presents that the adsorption of a Ga atom preferentially occurs at the center of three N atoms stacked on the nitrided LiGaO 2 (001) substrates, which leads to the formation of Ga-polarity GaN. Whereas the adsorption of a Ga atom preferentially deposits at the top of a N atom stacked on the non-nitrided LiGaO 2 (001) substrates, which results in the formation of N-polarity GaN. This work of controlling the polarity of GaN epitaxial films is of paramount importance for the fabrication of group-III nitride devices for various applications.

  16. Reactor control device

    International Nuclear Information System (INIS)

    Fukami, Haruo; Morimoto, Yoshinori.

    1981-01-01

    Purpose: To operate a reactor always with safety operation while eliminating the danger of tripping. Constitution: In a reactor control device adapted to detect the process variants of a reactor, control a control rod drive controlling system based on the detected signal to thereby control the driving the control rods, control the reactor power and control the electric power generated from an electric generator by the output from the reactor, detection means is provided for the detection of the electric power from said electric generator, and a compensation device is provided for outputting control rod driving compensation signals to the control rod driving controlling system in accordance with the amount of variation in the detected value. (Seki, T.)

  17. Generic device controller for accelerator control systems

    International Nuclear Information System (INIS)

    Mariotti, R.; Buxton, W.; Frankel, R.; Hoff, L.

    1987-01-01

    A new distributed intelligence control system has become operational at the AGS for transport, injection, and acceleration of heavy ions. A brief description of the functionality of the physical devices making up the system is given. An attempt has been made to integrate the devices for accelerator specific interfacing into a standard microprocessor system, namely, the Universal Device Controller (UDC). The main goals for such a generic device controller are to provide: local computing power; flexibility to configure; and real time event handling. The UDC assemblies and software are described

  18. Reversible Polarization Rotation in Epitaxial Ferroelectric Bilayers

    DEFF Research Database (Denmark)

    Liu, Guangqing; Zhang, Qi; Huang, Hsin-Hui

    2016-01-01

    Polarization rotation engineering is a promising path to giant dielectric and electromechanical responses in ferroelectric materials and devices. This work demonstrates robust and reversible in- to out-of-plane polarization rotation in ultrathin (nanoscale) epitaxial (001) tetragonal PbZr0.3Ti0.7O3...... large-scale polarization rotation switching (≈60 μC cm−2) and an effective d 33 response 500% (≈250 pm V−1) larger than the PZT-R layer alone. Furthermore, this enhancement is stable for more than 107 electrical switching cycles. These bilayers present a simple and highly controllable means to design...... and optimize rotational polar systems as an alternate to traditional composition-based approaches. The precise control of the subtle interface-driven interactions between the lattice and the external factors that control polarization opens a new door to enhanced—or completely new—functional properties....

  19. Control rod selecting and driving device

    International Nuclear Information System (INIS)

    Isobe, Hideo.

    1981-01-01

    Purpose: To simultaneously drive a predetermined number of control rods in a predetermined mode by the control of addresses for predetermined number of control rods and read or write of driving codified data to and from the memory by way of a memory controller. Constitution: The system comprises a control rod information selection device for selecting predetermined control rods from a plurality of control rods disposed in a reactor and outputting information for driving them in a predetermined mode, a control rod information output device for codifying the information outputted from the above device and outputting the addresses to the predetermined control rods and driving mode coded data, and a driving device for driving said predetermined control rods in a predetermined mode in accordance with the codified data outputted from the above device, said control rod infromation output device comprising a memory device capable of storing a predetermined number of the codified data and a memory control device for storing the predetermined number of data into the above memory device at a predetermined timing while successively outputting the thus stored predetermined number of data at a predetermined timing. (Seki, T.)

  20. Control rod drive hydraulic device

    International Nuclear Information System (INIS)

    Takekawa, Toru.

    1994-01-01

    The device of the present invention can reliably prevent a possible erroneous withdrawal of control rod driving mechanism when the pressure of a coolant line is increased by isolation operation of hydraulic control units upon periodical inspection for a BWR type reactor. That is, a coolant line is connected to the downstream of a hydraulic supply device. The coolant line is connected to a hydraulic control unit. A coolant hydraulic detection device and a pressure setting device are disposed to the coolant line. A closing signal line and a returning signal line are disposed, which connect the hydraulic supply device and a flow rate control valve for the hydraulic setting device. In the device of the present invention, even if pressure of supplied coolants is elevated due to isolation of hydraulic control units, the elevation of the hydraulic pressure can be prevented. Accordingly, reliability upon periodical reactor inspection can be improved. Further, the facility is simplified and the installation to an existent facility is easy. (I.S.)

  1. Metasurface for multi-channel terahertz beam splitters and polarization rotators

    Science.gov (United States)

    Zang, XiaoFei; Gong, HanHong; Li, Zhen; Xie, JingYa; Cheng, QingQing; Chen, Lin; Shkurinov, Alexander P.; Zhu, YiMing; Zhuang, SongLin

    2018-04-01

    Terahertz beam splitters and polarization rotators are two typical devices with wide applications ranging from terahertz communication to system integration. However, they are faced with severe challenges in manipulating THz waves in multiple channels, which is desirable for system integration and device miniaturization. Here, we propose a method to design ultra-thin multi-channel THz beam splitters and polarization rotators simultaneously. The reflected beams are divided into four beams with nearly the same density under illumination of linear-polarized THz waves, while the polarization of reflected beams in each channel is modulated with a rotation angle or invariable with respect to the incident THz waves, leading to the multi-channel polarization rotator (multiple polarization rotation in the reflective channels) and beam splitter, respectively. Reflective metasurfaces, created by patterning metal-rods with different orientations on a polyimide film, were fabricated and measured to demonstrate these characteristics. The proposed approach provides an efficient way of controlling polarization of THz waves in various channels, which significantly simplifies THz functional devices and the experimental system.

  2. Integrin-Mediated Interactions Control Macrophage Polarization in 3D Hydrogels

    NARCIS (Netherlands)

    Cha, Byung-Hyun; Ryon Shin, Su; Leijten, J.; Li, Yi-Chen; Singh, Sonali; Liu, Julie C.; Annabi, Nasim; Abdi, Reza; Dokmeci, Mehmet R.; Vrana, Nihal Engin; Ghaemmaghami, Amir M.; Khademhosseini, Ali

    2017-01-01

    Adverse immune reactions prevent clinical translation of numerous implantable devices and materials. Although inflammation is an essential part of tissue regeneration, chronic inflammation ultimately leads to implant failure. In particular, macrophage polarity steers the microenvironment toward

  3. Generation and control of polarization-entangled photons from GaAs island quantum dots by an electric field.

    Science.gov (United States)

    Ghali, Mohsen; Ohtani, Keita; Ohno, Yuzo; Ohno, Hideo

    2012-02-07

    Semiconductor quantum dots are potential sources for generating polarization-entangled photons efficiently. The main prerequisite for such generation based on biexciton-exciton cascaded emission is to control the exciton fine-structure splitting. Among various techniques investigated for this purpose, an electric field is a promising means to facilitate the integration into optoelectronic devices. Here we demonstrate the generation of polarization-entangled photons from single GaAs quantum dots by an electric field. In contrast to previous studies, which were limited to In(Ga)As quantum dots, GaAs island quantum dots formed by a thickness fluctuation were used because they exhibit a larger oscillator strength and emit light with a shorter wavelength. A forward voltage was applied to a Schottky diode to control the fine-structure splitting. We observed a decrease and suppression in the fine-structure splitting of the studied single quantum dot with the field, which enabled us to generate polarization-entangled photons with a high fidelity of 0.72 ± 0.05.

  4. Polarity Control of Heteroepitaxial GaN Nanowires on Diamond.

    Science.gov (United States)

    Hetzl, Martin; Kraut, Max; Hoffmann, Theresa; Stutzmann, Martin

    2017-06-14

    Group III-nitride materials such as GaN nanowires are characterized by a spontaneous polarization within the crystal. The sign of the resulting sheet charge at the top and bottom facet of a GaN nanowire is determined by the orientation of the wurtzite bilayer of the different atomic species, called N and Ga polarity. We investigate the polarity distribution of heteroepitaxial GaN nanowires on different substrates and demonstrate polarity control of GaN nanowires on diamond. Kelvin Probe Force Microscopy is used to determine the polarity of individual selective area-grown and self-assembled nanowires over a large scale. At standard growth conditions, mixed polarity occurs for selective GaN nanowires on various substrates, namely on silicon, on sapphire and on diamond. To obtain control over the growth orientation on diamond, the substrate surface is modified by nitrogen and oxygen plasma exposure prior to growth, and the growth parameters are adjusted simultaneously. We find that the surface chemistry and the substrate temperature are the decisive factors for obtaining control of up to 93% for both polarity types, whereas the growth mode, namely selective area or self-assembled growth, does not influence the polarity distribution significantly. The experimental results are discussed by a model based on the interfacial bonds between the GaN nanowires, the termination layer, and the substrate.

  5. Application of polarization information to a light-controlling-light technique.

    Science.gov (United States)

    Liang, J C; Wang, H C

    2017-09-15

    Nonlinear effects of photo-induced waveguides based on isomerization photochemistry are investigated. It is found that polarization information of the controlling light can be used to control the propagation of the signal light in all-optical waveguides, and an accurate and convenient light-controlling-light scheme is proposed, that is, controlling propagation of the signal light by synergic use of the intensity information and polarization information of the controlling light. The polarization dependence of optical nonlinearity is expected to enrich the connotation of the optical nonlinear effects and has theoretical significance and practical value.

  6. Spin-filter scanning tunneling microscopy : a novel technique for the analysis of spin polarization on magnetic surfaces and spintronic devices

    NARCIS (Netherlands)

    Vera Marun, I.J.

    2010-01-01

    This thesis deals with the development of a versatile technique to measure spin polarization with atomic resolution. A microscopy technique that can measure electronic spin polarization is relevant for characterization of magnetic nanostructures and spintronic devices. Scanning tunneling microscopy

  7. Control rod control device

    International Nuclear Information System (INIS)

    Seiji, Takehiko; Obara, Kohei; Yanagihashi, Kazumi

    1998-01-01

    The present invention provides a device suitable for switching of electric motors for driving each of control rods in a nuclear reactor. Namely, in a control rod controlling device, a plurality of previously allotted electric motors connected in parallel as groups, and electric motors of any selected group are driven. In this case, a voltage of not driving predetermined selected electric motors is at first applied. In this state an electric current supplied to the circuit of predetermined electric motors is detected. Whether integration or failure of a power source and the circuit of the predetermined electric motors are normal or not is judged by the detected electric current supplied. After they are judged normal, the electric motors are driven by a regular voltage. With such procedures, whether the selected circuit is normal or not can be accurately confirmed previously. Since the electric motors are not driven just at the selected time, the control rods are not operated erroneously. (I.S.)

  8. Method for forming permanent magnets with different polarities for use in microelectromechanical devices

    Science.gov (United States)

    Roesler, Alexander W [Tijeras, NM; Christenson, Todd R [Albuquerque, NM

    2007-04-24

    Methods are provided for forming a plurality of permanent magnets with two different north-south magnetic pole alignments for use in microelectromechanical (MEM) devices. These methods are based on initially magnetizing the permanent magnets all in the same direction, and then utilizing a combination of heating and a magnetic field to switch the polarity of a portion of the permanent magnets while not switching the remaining permanent magnets. The permanent magnets, in some instances, can all have the same rare-earth composition (e.g. NdFeB) or can be formed of two different rare-earth materials (e.g. NdFeB and SmCo). The methods can be used to form a plurality of permanent magnets side-by-side on or within a substrate with an alternating polarity, or to form a two-dimensional array of permanent magnets in which the polarity of every other row of the array is alternated.

  9. Polarization Control for Silicon Photonic Circuits

    Science.gov (United States)

    Caspers, Jan Niklas

    In recent years, the field of silicon photonics has received much interest from researchers and companies across the world. The idea is to use photons to transmit information on a computer chip in order to increase computational speed while decreasing the power required for computation. To allow for communication between the chip and other components, such as the computer memory, these silicon photonics circuits need to be interfaced with optical fiber. Unfortunately, in order to interface an optical fiber with an integrated photonics circuit two major challenges need to be overcome: a mode-size mismatch as well as a polarization mismatch. While the problem of mode-size has been well investigated, the polarization mismatch has yet to be addressed. In order to solve the polarization mismatch one needs to gain control over the polarization of the light in a waveguide. In this thesis, I will present the components required to solve the polarization mismatch. Using a novel wave guiding structure, the hybrid plasmonic waveguide, an ultra-compact polarization rotator is designed, fabricated, and tested. The hybrid plasmonic rotator has a performance similar to purely dielectric rotators while being more than an order of magnitude smaller. Additionally, a broadband hybrid plasmonic coupler is designed and measured. This coupler has a performance similar to dielectric couplers while having a footprint an order of magnitude smaller. Finally, a system solution to the polarization mismatch is provided. The system, a polarization adapter, matches the incoming changing polarization from the fiber actively to the correct one of the silicon photonics circuit. The polarization adapter is demonstrated experimentally to prove its operation. This proof is based on dielectric components, but the aforementioned hybrid plasmonic waveguide components would make the system more compact.

  10. Theory of electrically controlled resonant tunneling spin devices

    Science.gov (United States)

    Ting, David Z. -Y.; Cartoixa, Xavier

    2004-01-01

    We report device concepts that exploit spin-orbit coupling for creating spin polarized current sources using nonmagnetic semiconductor resonant tunneling heterostructures, without external magnetic fields. The resonant interband tunneling psin filter exploits large valence band spin-orbit interaction to provide strong spin selectivity.

  11. Control of beam size and polarization time in PEP

    International Nuclear Information System (INIS)

    Paterson, J.M.; Rees, J.R.; Wiedemann, H.

    1975-07-01

    In this report we describe a method of controlling beam size in which the focusing functions are not altered with beam energy but the curvature function is drastically altered in a few locations which comprise only a very small fraction of the circumference. As will be described in the following paper we are proposing to control the quantum excitation and radiation damping of the particles by means of special excitation magnets or /open quotes/wigglers/close quotes/. Since the mean square energy deviation and radial beam emittance are proportional approximately to E/sup 2//l angle/G/sup 3//r angle//l angle/G/sup 2//r angle//sup /minus/1 while the damping times are proportional to (E/sup 3//l angle/G/sup 2//r angle/)/sup /minus/1/, it is possible to achieve constant beam size in a constant focusing configuration while the damping times vary roughly as E/sup /minus/2/. In addition, it is possible to reduce the beam polarization time with these devices. A scheme for beam-size and damping control based on the same principle was described by M. Bassetti about a year ago, in which all of the storage-ring bending magnets were involved as wigglers, and a substantial increase in magnet cost resulted. The consequences for polarization times were not explored. The design formulae are derived and two specific applications to the PEP design in which the wigglers are installed in three of the six 5-m straight sections are described with attention given to practical magnet design, synchrotron radiation handling and other matters. 5 refs., 4 figs., 1 tab

  12. Fiber-based coherent polarization beam combining with cascaded phase-locking and polarization-transforming controls

    Science.gov (United States)

    Yang, Yan; Geng, Chao; Li, Feng; Huang, Guan; Li, Xinyang

    2018-05-01

    In this paper, the fiber-based coherent polarization beam combining (CPBC) with cascaded phase-locking (PL) and polarization-transforming (PT) controls was proposed to combine imbalanced input beams where the number of the input beams is not binary, in which the PL control was performed using the piezoelectric-ring fiber-optic phase compensator, and the PT control was realized by the dynamic polarization controller, simultaneously. The principle of the proposed CPBC was introduced. The performance of the proposed CPBC was analyzed in comparison with the CPBC based on PL control and the CPBC based on PT control. The basic experiment of CPBC of three laser beams was carried out to validate the feasibility of the proposed CPBC, where cascaded controls of PL and PT were implemented based on stochastic parallel gradient descent algorithm. Simulation and experimental results show that the proposed CPBC incorporates the advantages of the two previous CPBC schemes and performs well in the closed loop. Moreover, the expansibility and the application of the proposed CPBC were validated by scaling the CPBC to combine seven laser beams. We believe that the proposed fiber-based CPBC with cascaded PL and PT controls has great potential in free space optical communications employing the multi-aperture receiver with asymmetric structure.

  13. Compact electrically controlled broadband liquid crystal photonic bandgap fiber polarizer

    DEFF Research Database (Denmark)

    Wei, Lei; Alkeskjold, Thomas Tanggaard; Bjarklev, Anders Overgaard

    2009-01-01

    An electrically controlled liquid crystal photonic-bandgap fiber polarizer is experimentally demonstrated. A maximum 21.3dB electrically tunable polarization extinction ratio is achieved with 45° rotatable transmission axis as well as switched on and off in 1300nm–1600nm.......An electrically controlled liquid crystal photonic-bandgap fiber polarizer is experimentally demonstrated. A maximum 21.3dB electrically tunable polarization extinction ratio is achieved with 45° rotatable transmission axis as well as switched on and off in 1300nm–1600nm....

  14. Spin-polarized transport properties of a pyridinium-based molecular spintronics device

    Science.gov (United States)

    Zhang, J.; Xu, B.; Qin, Z.

    2018-05-01

    By applying a first-principles approach based on non-equilibrium Green's functions combined with density functional theory, the transport properties of a pyridinium-based "radical-π-radical" molecular spintronics device are investigated. The obvious negative differential resistance (NDR) and spin current polarization (SCP) effect, and abnormal magnetoresistance (MR) are obtained. Orbital reconstruction is responsible for novel transport properties such as that the MR increases with bias and then decreases and that the NDR being present for both parallel and antiparallel magnetization configurations, which may have future applications in the field of molecular spintronics.

  15. Arbitrary helicity control of circularly polarized light from lateral-type spin-polarized light-emitting diodes at room temperature

    Science.gov (United States)

    Nishizawa, Nozomi; Aoyama, Masaki; Roca, Ronel C.; Nishibayashi, Kazuhiro; Munekata, Hiro

    2018-05-01

    We demonstrate arbitrary helicity control of circularly polarized light (CPL) emitted at room temperature from the cleaved side facet of a lateral-type spin-polarized light-emitting diode (spin-LED) with two ferromagnetic electrodes in an antiparallel magnetization configuration. Driving alternate currents through the two electrodes results in polarization switching of CPL with frequencies up to 100 kHz. Furthermore, tuning the current density ratio in the two electrodes enables manipulation of the degree of circular polarization. These results demonstrate arbitrary electrical control of polarization with high speed, which is required for the practical use of lateral-type spin-LEDs as monolithic CPL light sources.

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

    Science.gov (United States)

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

    2016-12-15

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

  17. Polarization digital holographic microscopy using low-cost liquid crystal polarization rotators

    Science.gov (United States)

    Dovhaliuk, Rostyslav Yu

    2018-02-01

    Polarization imaging methods are actively used to study anisotropic objects. A number of methods and systems, such as imaging polarimeters, were proposed to measure the state of polarization of light that passed through the object. Digital holographic and interferometric approaches can be used to quantitatively measure both amplitude and phase of a wavefront. Using polarization modulation optics, the measurement capabilities of such interference-based systems can be extended to measure polarization-dependent parameters, such as phase retardation. Different kinds of polarization rotators can be used to alternate the polarization of a reference beam. Liquid crystals are used in a rapidly increasing number of different optoelectronic devices. Twisted nematic liquid crystals are widely used as amplitude modulators in electronic displays and light valves or shutter glass. Such devices are of particular interest for polarization imaging, as they can be used as polarization rotators, and due to large-scale manufacturing have relatively low cost. A simple Mach-Zehnder polarized holographic setup that uses modified shutter glass as a polarization rotator is demonstrated. The suggested approach is experimentally validated by measuring retardation of quarter-wave film.

  18. Improvement of the crossed undulator design for effective circular polarization control in X-ray FELs

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2011-01-15

    The production of X-ray radiation with a high degree of circular polarization constitutes an important goal at XFEL facilities. A simple scheme to obtain circular polarization control with crossed undulators has been proposed so far. In its simplest configuration the crossed undulators consist of pair of short planar undulators in crossed position separated by an electromagnetic phase shifter. An advantage of this configuration is a fast helicity switching. A drawback is that a high degree of circular polarization (over 90 %) can only be achieved for lengths of the insertion devices significantly shorter than the gain length, i.e. at output power significantly lower than the saturation power level. The obvious and technically possible extension considered in this paper, is to use a setup with two or more crossed undulators separated by phase shifters. This cascade crossed undulator scheme is distinguished, in performance, by a fast helicity switching, a high degree of circular polarization (over 95%) and a high output power level, comparable with the saturation power level in the baseline undulator at fundamental wavelength. We present feasibility study and exemplifications for the LCLS baseline in the soft X-ray regime. (orig.)

  19. Electronic device for measuring the polarization parameter in the π-p → π0n charge exchange reaction on a polarized proton target

    International Nuclear Information System (INIS)

    Brehin, S.

    1967-12-01

    An electronic apparatus has been constructed to measure the polarization parameter P 0 (t) in π - p → π 0 n charge exchange scattering at 5.9 GeV/c and 11,2 GeV/c on polarized proton target. This device insures triggering of a heavy plate spark chamber, allowing visualisation of γ rays from the π 0 decays when the associated neutron offers suitable characteristics in direction and energy. The neutron is detected by an array of 32 counters and his energy is measured by a time of flight method. Electronic circuits of this apparatus are described as test and calibration methods used. (author) [fr

  20. Genetic control of organ shape and tissue polarity.

    Directory of Open Access Journals (Sweden)

    Amelia A Green

    2010-11-01

    Full Text Available The mechanisms by which genes control organ shape are poorly understood. In principle, genes may control shape by modifying local rates and/or orientations of deformation. Distinguishing between these possibilities has been difficult because of interactions between patterns, orientations, and mechanical constraints during growth. Here we show how a combination of growth analysis, molecular genetics, and modelling can be used to dissect the factors contributing to shape. Using the Snapdragon (Antirrhinum flower as an example, we show how shape development reflects local rates and orientations of tissue growth that vary spatially and temporally to form a dynamic growth field. This growth field is under the control of several dorsoventral genes that influence flower shape. The action of these genes can be modelled by assuming they modulate specified growth rates parallel or perpendicular to local orientations, established by a few key organisers of tissue polarity. Models in which dorsoventral genes only influence specified growth rates do not fully account for the observed growth fields and shapes. However, the data can be readily explained by a model in which dorsoventral genes also modify organisers of tissue polarity. In particular, genetic control of tissue polarity organisers at ventral petal junctions and distal boundaries allows both the shape and growth field of the flower to be accounted for in wild type and mutants. The results suggest that genetic control of tissue polarity organisers has played a key role in the development and evolution of shape.

  1. Significant electrical control of amorphous oxide thin film transistors by an ultrathin Ti surface polarity modifier

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Byungsu [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Samsung Display Co. Ltd., Tangjeong, Chungcheongnam-Do 336-741 (Korea, Republic of); Choi, Yonghyuk; Shin, Seokyoon [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Jeon, Heeyoung [Department of Nano-scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Seo, Hyungtak, E-mail: hseo@ajou.ac.kr [Department of Materials Science and Engineering and Energy Systems Research, Ajou University, Suwon 443-739 (Korea, Republic of); Jeon, Hyeongtag, E-mail: hjeon@hanyang.ac.kr [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Department of Nano-scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2014-01-27

    We demonstrate an enhanced electrical stability through a Ti oxide (TiO{sub x}) layer on the amorphous InGaZnO (a-IGZO) back-channel; this layer acts as a surface polarity modifier. Ultrathin Ti deposited on the a-IGZO existed as a TiO{sub x} thin film, resulting in oxygen cross-binding with a-IGZO surface. The electrical properties of a-IGZO thin film transistors (TFTs) with TiO{sub x} depend on the surface polarity change and electronic band structure evolution. This result indicates that TiO{sub x} on the back-channel serves as not only a passivation layer protecting the channel from ambient molecules or process variables but also a control layer of TFT device parameters.

  2. Simulation and Automation of Microwave Frequency Control in Dynamic Nuclear Polarization for Solid Polarized Targets

    Science.gov (United States)

    Perera, Gonaduwage; Johnson, Ian; Keller, Dustin

    2017-09-01

    Dynamic Nuclear Polarization (DNP) is used in most of the solid polarized target scattering experiments. Those target materials must be irradiated using microwaves at a frequency determined by the difference in the nuclear Larmor and electron paramagnetic resonance (EPR) frequencies. But the resonance frequency changes with time as a result of radiation damage. Hence the microwave frequency should be adjusted accordingly. Manually adjusting the frequency can be difficult, and improper adjustments negatively impact the polarization. In order to overcome these difficulties, two controllers were developed which automate the process of seeking and maintaining the optimal frequency: one being a standalone controller for a traditional DC motor and the other a LabVIEW VI for a stepper motor configuration. Further a Monte-Carlo simulation was developed which can accurately model the polarization over time as a function of microwave frequency. In this talk, analysis of the simulated data and recent improvements to the automated system will be presented. DOE.

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

    KAUST Repository

    Cheng, Yingchun

    2014-04-28

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

  4. EDITORIAL: Non-polar and semipolar nitride semiconductors Non-polar and semipolar nitride semiconductors

    Science.gov (United States)

    Han, Jung; Kneissl, Michael

    2012-02-01

    topics including growth and heteroepitaxy, bulk GaN substrates, theory and modelling, optical properties, laser diodes and LEDs as well as transport properties and electronics. Farrell et al review materials and growth issues for high-performance non- and semipolar light-emitting devices, and Scholz provides an overview of heteroepitaxial growth of semipolar GaN. Okada et al review growth mechanisms of non- and semipolar GaN layers on patterned sapphire substrates, and Vennéguès discusses defect reduction methods for heteroepitaxially grown non- and semipolar III-nitride films. Leung et al explain how kinetic Wulff plots can be used to design and control non-polar and semipolar GaN heteroepitaxy, and a contribution by Sawaki et al explores the impurity incorporation in (1-101) GaN grown on Si substrates. In the area of bulk crystal growth Kucharski et al review non- and semipolar GaN substrates by ammonothermal growth, and Chichibu et al discuss the challenges for epitaxial growth of InGaN on free-standing m-plane GaN substrates. Calculation of semipolar orientations for wurtzitic semiconductor heterostructures and their application to nitrides and oxides are reviewed by Bigenwald et al, and Ito et al present an ab initio approach to reconstruction, adsorption, and incorporation on GaN surfaces. Finally, the theoretical description of non-polar and semipolar nitride semiconductor quantum-well structures is presented by Ahn et al. In a discussion of the optical properties, Kisin et al discuss the effect of the quantum well population on the optical characteristics of polar, semipolar and non-polar III-nitride light emitters, and Jönen et al investigate the indium incorporation and optical properties of non- and semipolar GaInN QW structures. Wernicke et al explore the emission wavelength of polar, non-polar, and semipolar InGaN quantum wells and the incorporation of indium. In a contribution by Melo et al, the gain in polar and non-polar/semipolar gallium

  5. Rotated infrared antenna transmitarray for the manipulation of circularly polarized wavefronts

    Directory of Open Access Journals (Sweden)

    He Yuchu

    2014-01-01

    Full Text Available An IR optical transmitarray is presented based on Antenna Array Sheet (AAS for the manipulation of circularly polarized light. The unit cell of the transmitarray comprises three layers of metallic elliptical patches. Complete phase control is achieved through the local rotation of each unit cell. Thin refraction and focusing transmitarrays of this sort are demonstrated at infrared frequencies. Moreover, a new concept for realizing a polarization-discriminating device is introduced based on a flat refracting lens. These devices are compatible with current fabrication technology and can become crucial for the integration with other IR and nano-photonic devices.

  6. Attosecond polarization control in atomic RABBITT-like experiments assisted by a circularly polarized laser

    Science.gov (United States)

    Boll, D. I. R.; Fojón, O. A.

    2017-12-01

    We study theoretically the single ionization of noble gas atoms by the combined action of an attosecond pulse train with linear polarization and an assistant laser field with circular polarization. We employ a non-perturbative model that under certain approximations gives closed-form expressions for the angular distributions of photoelectrons. Interestingly, our model allow us to interpret these angular distributions as two-centre interferences where the orientation and the modulus of the separation vector between the virtual emitters is governed by the assistant laser field. Additionally, we show that such a configuration of light fields is similar to the polarization control technique, where both the attosecond pulse train and the assistant laser field have linear polarizations whose relative orientation may be controlled. Moreover, in order to compare our results with the available experimental data, we obtain analytical expressions for the cross sections integrated over the photoelectron emission angles. By means of these expressions, we define the ‘magic time’ as the delay for which the total cross sections for atomic targets exhibit the same functional form as the one of the monochromatic photoionization of diatomic molecular targets.

  7. Optical neutron polarizers

    International Nuclear Information System (INIS)

    Hayter, J.B.

    1990-01-01

    A neutron wave will be refracted by an appropriately varying potential. Optical neutron polarizers use spatially varying, spin- dependent potentials to refract neutrons of opposite spin states into different directions, so that an unpolarized beam will be split into two beams of complementary polarization by such a device. This paper will concentrate on two methods of producing spin-dependent potentials which are particularly well-suited to polarizing cold neutron beams, namely thin-film structures and field-gradient techniques. Thin-film optical devices, such as supermirror multilayer structures, are usually designed to deviate only one spin-state, so that they offer the possibility of making insertion (transmission) polarizers. Very good supermirrors may now be designed and fabricated, but it is not always straightforward to design mirror-based devices which are useful in real (divergent beam) applications, and some practical configurations will be discussed. Field-gradient devices, which are usually based on multipolar magnets, have tended to be too expensive for general use, but this may change with new developments in superconductivity. Dipolar and hexapolar configurations will be considered, with emphasis on the focusing characteristics of the latter. 21 refs., 7 figs

  8. Intrinsic fluorescence for cervical precancer detection using polarized light based in-house fabricated portable device

    Science.gov (United States)

    Meena, Bharat Lal; Singh, Pankaj; Sah, Amar Nath; Pandey, Kiran; Agarwal, Asha; Pantola, Chayanika; Pradhan, Asima

    2018-01-01

    An in-house fabricated portable device has been tested to detect cervical precancer through the intrinsic fluorescence from human cervix of the whole uterus in a clinical setting. A previously validated technique based on simultaneously acquired polarized fluorescence and polarized elastic scattering spectra from a turbid medium is used to extract the intrinsic fluorescence. Using a diode laser at 405 nm, intrinsic fluorescence of flavin adenine dinucleotide, which is the dominant fluorophore and other contributing fluorophores in the epithelium of cervical tissue, has been extracted. Different grades of cervical precancer (cervical intraepithelial neoplasia; CIN) have been discriminated using principal component analysis-based Mahalanobis distance and linear discriminant analysis. Normal, CIN I and CIN II samples have been discriminated from one another with high sensitivity and specificity at 95% confidence level. This ex vivo study with cervix of whole uterus samples immediately after hysterectomy in a clinical environment indicates that the in-house fabricated portable device has the potential to be used as a screening tool for in vivo precancer detection using intrinsic fluorescence.

  9. Control system of fuel transporting device

    International Nuclear Information System (INIS)

    Yokota, Minoru.

    1981-01-01

    Purpose: To effectively avoid an obstacle in a fuel transporting device by reading the outputs of absolute position detectors mounted on movable trucks, controlling the movements of the trucks, and thereby smoothly and accurately positioning the fuel transporting device at predetermined position and providing a contact detector thereat. Method: The outputs from absolute position detectors which are mounted on a longitudinally movable truck and a laterally movable truck are input to an input/output control circuit. The input/output control circuit serves to compare, the position a fuel transporting device is to be moved to, with the present position on the basis of said input detection signal and a command signal from an operator console, to calculate the amount of movement to be driven, to produce an operation signal therefor to a control panel, and to drive and control the drive motors which are respectively mounted on the trucks for the fuel transfer device. On the other hand, in case that the transfer device comes into contact with an obstacle, the contact detector will immediately operate to produce a stop command through the control panel to the transporting device, and avoid a collision with the obstacle. (Yoshino, Y.)

  10. Continuous control of spin polarization using a magnetic field

    Science.gov (United States)

    Gifford, J. A.; Zhao, G. J.; Li, B. C.; Tracy, Brian D.; Zhang, J.; Kim, D. R.; Smith, David J.; Chen, T. Y.

    2016-05-01

    The giant magnetoresistance (GMR) of a point contact between a Co/Cu multilayer and a superconductor tip varies for different bias voltage. Direct measurement of spin polarization by Andreev reflection spectroscopy reveals that the GMR change is due to a change in spin polarization. This work demonstrates that the GMR structure can be utilized as a spin source and that the spin polarization can be continuously controlled by using an external magnetic field.

  11. Continuous control of spin polarization using a magnetic field

    International Nuclear Information System (INIS)

    Gifford, J. A.; Zhao, G. J.; Li, B. C.; Tracy, Brian D.; Zhang, J.; Kim, D. R.; Smith, David J.; Chen, T. Y.

    2016-01-01

    The giant magnetoresistance (GMR) of a point contact between a Co/Cu multilayer and a superconductor tip varies for different bias voltage. Direct measurement of spin polarization by Andreev reflection spectroscopy reveals that the GMR change is due to a change in spin polarization. This work demonstrates that the GMR structure can be utilized as a spin source and that the spin polarization can be continuously controlled by using an external magnetic field.

  12. Continuous control of spin polarization using a magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Gifford, J. A.; Zhao, G. J.; Li, B. C.; Tracy, Brian D.; Zhang, J.; Kim, D. R.; Smith, David J.; Chen, T. Y., E-mail: tingyong.chen@asu.edu [Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States)

    2016-05-23

    The giant magnetoresistance (GMR) of a point contact between a Co/Cu multilayer and a superconductor tip varies for different bias voltage. Direct measurement of spin polarization by Andreev reflection spectroscopy reveals that the GMR change is due to a change in spin polarization. This work demonstrates that the GMR structure can be utilized as a spin source and that the spin polarization can be continuously controlled by using an external magnetic field.

  13. Fluid circulation control device

    International Nuclear Information System (INIS)

    Benard, Henri; Henocque, Jean.

    1982-01-01

    Horizontal fluid circulation control device, of the type having a pivoting flap. This device is intended for being fitted in the pipes of hydraulic installation, particularly in a bleed and venting system of a nuclear power station shifting radioactive or contaminated liquids. The characteristic of this device is the cut-out at the top of the flap to allow the air contained in the pipes to flow freely [fr

  14. Control of emitted light polarization in a 1310 nm dilute nitride spin-vertical cavity surface emitting laser subject to circularly polarized optical injection

    Energy Technology Data Exchange (ETDEWEB)

    Alharthi, S. S., E-mail: ssmalh@essex.ac.uk; Hurtado, A.; Al Seyab, R. K.; Henning, I. D.; Adams, M. J. [School of Computer Science and Electronic Engineering, University of Essex, Wivenhoe Park, Colchester CO4 3SQ (United Kingdom); Korpijarvi, V.-M.; Guina, M. [Optoelectronics Research Centre (ORC), Tampere University of Technology, P.O. Box 692, FIN-33101 Tampere (Finland)

    2014-11-03

    We experimentally demonstrate the control of the light polarization emitted by a 1310 nm dilute nitride spin-Vertical Cavity Surface Emitting Laser (VCSEL) at room temperature. This is achieved by means of a combination of polarized optical pumping and polarized optical injection. Without external injection, the polarization of the optical pump controls that of the spin-VCSEL. However, the addition of the externally injected signal polarized with either left- (LCP) or right-circular polarization (RCP) is able to control the polarization of the spin-VCSEL switching it at will to left- or right-circular polarization. A numerical model has been developed showing a very high degree of agreement with the experimental findings.

  15. A device for the hydraulic control of nuclear reactor control rods

    International Nuclear Information System (INIS)

    Frisch, Erling; Frisch, D.R.; Andrews, H.N.

    1974-01-01

    A device for driving and locking the control rods of a nuclear reactor. This device comprises a hydraulic driving piston mounted in a cylinder provided with a construction for absorbing shocks. The piston is provided, at is extremity, with a locking device adapted to engage a stationary lock, it being possible to control the latter for freeing said piston locking device; with such an arrangement, the control rod is normally maintained in position, and it can be freed only by a positive signal. Moreover, the control rod movements are slowed down, so as to prevent the gripping device from being damaged. This device can be used in the nuclear industry [fr

  16. Monitoring device for withdrawing control rods

    International Nuclear Information System (INIS)

    Higashigawa, Yuichi.

    1985-01-01

    Purpose: To improve the sensitivity and the responsivity to an equivalent extent to those in the case where local power range monitors are densely arranged near each of the control rods, with no actual but pseudo increase of the number of local power range monitors. Constitution: The monitor arrangement is patterned by utilizing the symmetricity of the reactor core and stored in a monitor designating device. The symmetricity of control rods to be selected and withdrawn by an operator is judged by a control rod symmetry monitoring device, while the symmetricity of the withdrawn control rods is judged by a control rod withdrawal state monitoring device. Then, only when both of the devices judge the symmetricity, the control rods are subjected to gang driving by the control rod drive mechanisms. In this way, monitoring at a high sensitivity and responsivity is enabled with no increase for the number of monitors. (Yoshino, Y.)

  17. Electron-Spin Filters Would Offer Spin Polarization Greater than 1

    Science.gov (United States)

    Ting, David Z.

    2009-01-01

    A proposal has been made to develop devices that would generate spin-polarized electron currents characterized by polarization ratios having magnitudes in excess of 1. Heretofore, such devices (denoted, variously, as spin injectors, spin polarizers, and spin filters) have typically offered polarization ratios having magnitudes in the approximate range of 0.01 to 0.1. The proposed devices could be useful as efficient sources of spin-polarized electron currents for research on spintronics and development of practical spintronic devices.

  18. Mechanism of anterior-posterior polarity control in planarians

    Energy Technology Data Exchange (ETDEWEB)

    Lange, C.S.; Steele, V.E.

    1978-01-01

    The substance which inhibits brain formation in the regenerating planarian Dugesia etrusca was found to be a large molecule, at least in part protein, which electrophoreses as an electronegative moiety in pH 6.8 buffer. A model is presented, based on this finding and previous studies, which proposes an electrochemical mechanism for the control of polarity and possibly for the maintenance of tissue organization in planarians. It is proposed that a bioelectric field exists and moves the electronegative brain-inhibiting substance in a posterior direction, establishing polarity. This model explains the polarity reversal experiments using external fields and many of the previously unexplained classical planarian experiments. Data are presented demonstrating the existence, magnitude, and polarity of this bioelectric field, which is not greatly altered upon decapitation, all in accord with predictions of the model.

  19. Highly spin-polarized materials and devices for spintronics∗.

    Science.gov (United States)

    Inomata, Koichiro; Ikeda, Naomichi; Tezuka, Nobuki; Goto, Ryogo; Sugimoto, Satoshi; Wojcik, Marek; Jedryka, Eva

    2008-01-01

    The performance of spintronics depends on the spin polarization of the current. In this study half-metallic Co-based full-Heusler alloys and a spin filtering device (SFD) using a ferromagnetic barrier have been investigated as highly spin-polarized current sources. The multilayers were prepared by magnetron sputtering in an ultrahigh vacuum and microfabricated using photolithography and Ar ion etching. We investigated two systems of Co-based full-Heusler alloys, Co 2 Cr 1 - x Fe x Al (CCFA( x )) and Co 2 FeSi 1 - x Al x (CFSA( x )) and revealed the structure and magnetic and transport properties. We demonstrated giant tunnel magnetoresistance (TMR) of up to 220% at room temperature and 390% at 5 K for the magnetic tunnel junctions (MTJs) using Co 2 FeSi 0.5 Al 0.5 (CFSA(0.5)) Heusler alloy electrodes. The 390% TMR corresponds to 0.81 spin polarization for CFSA(0.5) at 5 K. We also investigated the crystalline structure and local structure around Co atoms by x-ray diffraction (XRD) and nuclear magnetic resonance (NMR) analyses, respectively, for CFSA films sputtered on a Cr-buffered MgO (001) substrate followed by post-annealing at various temperatures in an ultrahigh vacuum. The disordered structures in CFSA films were clarified by NMR measurements and the relationship between TMR and the disordered structure was discussed. We clarified that the TMR of the MTJs with CFSA(0.5) electrodes depends on the structure, and is significantly higher for L2 1 than B2 in the crystalline structure. The second part of this paper is devoted to a SFD using a ferromagnetic barrier. The Co ferrite is investigated as a ferromagnetic barrier because of its high Curie temperature and high resistivity. We demonstrate the strong spin filtering effect through an ultrathin insulating ferrimagnetic Co-ferrite barrier at a low temperature. The barrier was prepared by the surface plasma oxidization of a CoFe 2 film deposited on a MgO (001) single crystal substrate, wherein the spinel

  20. Polarization control of multi-photon absorption under intermediate femtosecond laser field

    International Nuclear Information System (INIS)

    Cheng Wenjing; Liang Guo; Wu Ping; Liu Pei; Jia Tianqing; Sun Zhenrong; Zhang Shian

    2017-01-01

    It has been shown that the femtosecond laser polarization modulation is a very simple and well-established method to control the multi-photon absorption process by the light–matter interaction. Previous studies mainly focused on the multi-photon absorption control in the weak field. In this paper, we further explore the polarization control behavior of multi-photon absorption process in the intermediate femtosecond laser field. In the weak femtosecond laser field, the second-order perturbation theory can well describe the non-resonant two-photon absorption process. However, the higher order nonlinear effect (e.g., four-photon absorption) can occur in the intermediate femtosecond laser field, and thus it is necessary to establish new theoretical model to describe the multi-photon absorption process, which includes the two-photon and four-photon transitions. Here, we construct a fourth-order perturbation theory to study the polarization control behavior of this multi-photon absorption under the intermediate femtosecond laser field excitation, and our theoretical results show that the two-photon and four-photon excitation pathways can induce a coherent interference, while the coherent interference is constructive or destructive that depends on the femtosecond laser center frequency. Moreover, the two-photon and four-photon transitions have the different polarization control efficiency, and the four-photon absorption can obtain the higher polarization control efficiency. Thus, the polarization control efficiency of the whole excitation process can be increased or decreased by properly designing the femtosecond laser field intensity and laser center frequency. These studies can provide a clear physical picture for understanding and controlling the multi-photon absorption process in the intermediate femtosecond laser field, and also can provide a theoretical guidance for the future experimental realization. (paper)

  1. Composition tuning of rectifying polarity of colloidal CdS{sub 1−x}Se{sub x} nanocrystal-based devices

    Energy Technology Data Exchange (ETDEWEB)

    An, Yuehua; Wu, Zhenping; Chu, Xulong; Guo, Daoyou; Guo, Xuncai [Beijing University of Posts and Telecommunications, Laboratory of Optoelectronics Materials and Devices, School of Science (China); Li, Linghong [The State University of New York at Potsdam, Physics Department (United States); Li, Peigang, E-mail: pgli@zstu.edu.cn [Zhejiang Sci-Tech University, Department of Physics, Center for Optoelectronics Materials and Devices (China); Tang, Hao [The University of Tennessee at Knoxville, Department of Chemistry (United States); Tang, Weihua, E-mail: whtang@bupt.edu.cn [Beijing University of Posts and Telecommunications, Laboratory of Optoelectronics Materials and Devices, School of Science (China)

    2015-03-15

    CdS{sub 1–x}Se{sub x} colloidal nanocrystals (NCs) were synthesized by colloidal chemistry route. Both lattice parameters and band structure were modulated by tuning the content of Se. As the Se content increases, the peak of UV–Visible absorbance spectrum of CdS{sub 1−x}Se{sub x} shifts toward longer wavelength direction, indicating the reduction of band gap. Devices with Au/CdS{sub 1−x}Se{sub x} NCs/Au structures have been fabricated by assembling the obtained CdS{sub 1−x}Se{sub x} NCs into Au microelectrodes via dielectrophoresis method. It is found that the rectifying polarities of the devices are strongly dependent on the content of Se. With the increasing Se content, the rectification polarity changes from backward to forward. This polarity tuning could be caused by the change of the relative height of the Fermi levels between CdS{sub 1−x}Se{sub x} and Au. The Se-content-dependent rectifying behavior may offer us an opportunity to design novel logical structure in NC-based nanoelectronics.

  2. Integrated optical circuit comprising a polarization convertor

    NARCIS (Netherlands)

    1998-01-01

    An integrated optical circuit includes a first device and a second device, which devices are connected by a polarization convertor. The polarization convertor includes a curved section of a waveguide, integrated in the optical circuit. The curved section may have several differently curved

  3. Control the polarization state of light with symmetry-broken metallic metastructures

    International Nuclear Information System (INIS)

    Xiong, Xiang; Jiang, Shang-Chi; Hu, Yuan-Sheng; Hu, Yu-Hui; Wang, Zheng-Han; Peng, Ru-Wen; Wang, Mu

    2015-01-01

    Controlling the polarization state, the transmission direction, the amplitude and the phase of light in a very limited space is essential for the development of on-chip photonics. Over the past decades, numerous sub-wavelength metallic microstructures have been proposed and fabricated to fulfill these demands. In this article, we review our efforts in achieving negative refractive index, controlling the polarization state, and tuning the amplitude of light with two-dimensional (2D) and three-dimensional (3D) microstructures. We designed an assembly of stacked metallic U-shaped resonators that allow achieving negative refraction for pure magnetic and electric responses respectively at the same frequency by selecting the polarization of incident light. Based on this, we tune the permittivity and permeability of the structure, and achieve negative refractive index. Further, by control the excitation and radiation of surface electric current on a number of 2D and 3D asymmetric metallic metastructures, we are able to control the polarization state of light. It is also demonstrated that with a stereostructured metal film, the whole metal surfaces can be used to construct either polarization-sensitive or polarization-insensitive prefect absorbers, with the advantage of efficient heat dissipation and electric conductivity. Our practice shows that metamaterials, including metasurface, indeed help to master light in nanoscale, and are promising in the development of new generation of photonics

  4. Polarization-controlled asymmetric excitation of surface plasmons

    KAUST Repository

    Xu, Quan; Zhang, Xueqian; Yang, Quanlong; Tian, Chunxiu; Xu, Yuehong; Zhang, Jianbing; Zhao, Hongwei; Li, Yanfeng; Ouyang, Chunmei; Tian, Zhen; Gu, Jianqiang; Zhang, Xixiang; Han, Jiaguang; Zhang, Weili

    2017-01-01

    Free-space light can be coupled into propagating surface waves at a metal–dielectric interface, known as surface plasmons (SPs). This process has traditionally faced challenges in preserving the incident polarization information and controlling

  5. Remote control of Alfven eigenmode sensing system on the large helical device

    International Nuclear Information System (INIS)

    Ito, T.; Toi, K.; Matsunaga, G.

    2008-01-01

    An active sensing system of Alfven eigenmodes (AEs), which consists of a set of toroidally distributed loop antennas and several bi-polar power supplies, has been developed in the large helical device (LHD). The power supplies are controlled with a function generator receiving a control pattern of antenna current and the driving frequency from a personal computer (PC) in an LHD control room. This sensing method is based on the analysis of the frequency dependence of a transfer function that is derived by the ratio of the Fourier-transformed magnetic probe signal ('plasma response') to antenna current one ('exciter signal'). Typically, the driving frequency of the antenna current is swept linearly in time from 10 kHz to 500 kHz for 2 s in the LHD experiment. The sensing system is fully controlled through Ethernet LAN with easy extendable GUI. Configuration and control scheme of the active sensing system of AEs are presented in this paper. An initial result of the system operation is also described

  6. Control method for prosthetic devices

    Science.gov (United States)

    Bozeman, Richard J., Jr. (Inventor)

    1995-01-01

    A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the moveable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the moveable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective moveable prosthesis device and its sub-prosthesis.

  7. Pin cushion plasmonic device for polarization beam splitting, focusing, and beam position estimation.

    Science.gov (United States)

    Lerman, Gilad M; Levy, Uriel

    2013-03-13

    Great hopes rest on surface plasmon polaritons' (SPPs) potential to bring new functionalities and applications into various branches of optics. In this paper, we demonstrate a pin cushion structure capable of coupling light from free space into SPPs, split them based on the polarization content of the illuminating beam of light, and focus them into small spots. We also show that for a circularly or randomly polarized light, four focal spots will be generated at the center of each quarter circle comprising the pin cushion device. Furthermore, following the relation between the relative intensity of the obtained four focal spots and the relative position of the illuminating beam with respect to the structure, we propose and demonstrate the potential use of our structure as a miniaturized plasmonic version of the well-known four quadrant detector. Additional potential applications may vary from multichannel microscopy and multioptical traps to real time beam tracking systems.

  8. Remote controlled transport device

    International Nuclear Information System (INIS)

    Nakahira, Masataka; Oka, Kiyoshi; Ito, Akira; Tada, Eisuke; Sato, Masaki

    1998-01-01

    The present invention provides a device for transporting equipments for maintenance and parts between a maintenance port and a facility for maintenance by remote control in a radioactive material handling facility such as a nuclear power plant. Namely, a power supply bus bar is disposed along a transferring path in order to supply power to a transporting means, and is divided into every region having a predetermined length. Each of the power supply bus bar regions is controlled for the power supply by a control device. Accordingly, the transporting means can be moved and driven successively being independent on every power supply bus bar region. Accordingly, a plurality of transporting means can be operated independently in a transferring path without laying around power cables and control signal cables. (I.S.)

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

    KAUST Repository

    Cheng, Yingchun; Zhang, Q. Y.; Schwingenschlö gl, Udo

    2014-01-01

    We demonstrate that valley polarization can be induced and controlled in semiconducting single-layer transition-metal dichalcogenides by magnetic doping, which is important for spintronics, valleytronics, and photonics devices. As an example, we

  10. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides

    International Nuclear Information System (INIS)

    Wang Ziming; Zhao Xin; Xu Xu; Wu Lijie; Su Rui; Zhao Yajing; Jiang Chengfei; Zhang Hanqi; Ma Qiang; Lu Chunmei; Dong Deming

    2013-01-01

    Highlights: ► An absorbing microwave μ-SPE device packed with activated carbon was used. ► Absorbing microwave μ-SPE device was made and used to enrich the analytes. ► Absorbing microwave μ-SPE device was made and used to heat samples directly. ► MAE-μ-SPE was applied to the extraction of OPPs with non-polar solvent only. - Abstract: A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction (μ-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave μ-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in μ-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave μ-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 °C for 10 min. The extracts obtained by MAE-μ-SPE were directly analyzed by GC–MS without any clean-up process. The recoveries were in the range of 93.5–104.6%, and the relative standard deviations were lower than 8.7%.

  11. The control system of the polarized internal target of ANKE at COSY

    Energy Technology Data Exchange (ETDEWEB)

    Kleines, H. [Zentralinstitut fuer Elektronik, Forschungszentrum Juelich, 52425 Juelich (Germany); Sarkadi, J. [Zentralinstitut fuer Elektronik, Forschungszentrum Juelich, 52425 Juelich (Germany); Zwoll, K. [Zentralinstitut fuer Elektronik, Forschungszentrum Juelich, 52425 Juelich (Germany); Engels, R. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Grigoryev, K. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Mikirtychyants, M. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Nekipelov, M. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Rathmann, F. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Seyfarth, H. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany)]. E-mail: h.seyfarth@fz-juelich.de; Kravtsov, P. [St. Petersburg Nuclear Physics Institute, 188350 Gatchina (Russian Federation); Vasilyev, A. [St. Petersburg Nuclear Physics Institute, 188350 Gatchina (Russian Federation)

    2006-05-10

    The polarized internal target for the ANKE experiment at the Cooler Synchrotron COSY of the Forschungszentrum Juelich utilizes a polarized atomic beam source to feed a storage cell with polarized hydrogen or deuterium atoms. The nuclear polarization is measured with a Lamb-shift polarimeter. For common control of the two systems, industrial equipment was selected providing reliable, long-term support and remote control of the target as well as measurement and optimization of its operating parameters. The interlock system has been implemented on the basis of SIEMENS SIMATIC S7-300 family of programmable logic controllers. In order to unify the interfacing to the control computer, all front-end equipment is connected via the PROFIBUS DP fieldbus. The process control software was implemented using the Windows-based WinCC toolkit from SIEMENS. The variety of components, to be controlled, and the logical structure of the control and interlock system are described. Finally, a number of applications derived from the present development to other, new installations are briefly mentioned.

  12. The control system of the polarized internal target of ANKE at COSY

    Science.gov (United States)

    Kleines, H.; Sarkadi, J.; Zwoll, K.; Engels, R.; Grigoryev, K.; Mikirtychyants, M.; Nekipelov, M.; Rathmann, F.; Seyfarth, H.; Kravtsov, P.; Vasilyev, A.

    2006-05-01

    The polarized internal target for the ANKE experiment at the Cooler Synchrotron COSY of the Forschungszentrum Jülich utilizes a polarized atomic beam source to feed a storage cell with polarized hydrogen or deuterium atoms. The nuclear polarization is measured with a Lamb-shift polarimeter. For common control of the two systems, industrial equipment was selected providing reliable, long-term support and remote control of the target as well as measurement and optimization of its operating parameters. The interlock system has been implemented on the basis of SIEMENS SIMATIC S7-300 family of programmable logic controllers. In order to unify the interfacing to the control computer, all front-end equipment is connected via the PROFIBUS DP fieldbus. The process control software was implemented using the Windows-based WinCC toolkit from SIEMENS. The variety of components, to be controlled, and the logical structure of the control and interlock system are described. Finally, a number of applications derived from the present development to other, new installations are briefly mentioned.

  13. Electrostatic charging and control of droplets in microfluidic devices.

    Science.gov (United States)

    Zhou, Hongbo; Yao, Shuhuai

    2013-03-07

    Precharged droplets can facilitate manipulation and control of low-volume liquids in droplet-based microfluidics. In this paper, we demonstrate non-contact electrostatic charging of droplets by polarizing a neutral droplet and splitting it into two oppositely charged daughter droplets in a T-junction microchannel. We performed numerical simulation to analyze the non-contact charging process and proposed a new design with a notch at the T-junction in aid of droplet splitting for more efficient charging. We experimentally characterized the induced charge in droplets in microfabricated devices. The experimental results agreed well with the simulation. Finally, we demonstrated highly effective droplet manipulation in a path selection unit appending to the droplet charging. We expect our work could enable precision manipulation of droplets for more complex liquid handling in microfluidics and promote electric-force based manipulation in 'lab-on-a-chip' systems.

  14. Operation control device under radiation exposure

    International Nuclear Information System (INIS)

    Kimura, Kiichi; Murakami, Toichi.

    1994-01-01

    The device of the present invention performs smooth progress of operation by remote control for a plurality of operations in periodical inspections in controlled areas of a nuclear power plant, thereby reducing the operator's exposure dose. Namely, the device monitors the progressing state of the operation by displaying the progress of operation on a CRT of a centralized control device present in a low dose area remote from an operation field through an ITV camera disposed in the vicinity of the operation field. Further, operation sequence and operation instruction procedures previously inputted in the device are indicated to the operation field through an operation instruction outputting device (field CRT) in accordance with the progress of the operation steps. On the other hand, the operation progress can be aided by inputting information from the operation field such as start or completion of the operation steps. Further, the device of the present invention can monitor the change of operation circumstances and exposure dose of operators based on the information from a radiation dose measuring device disposed in the operation circumstance and to individual operators. (I.S.)

  15. Control System for Prosthetic Devices

    Science.gov (United States)

    Bozeman, Richard J. (Inventor)

    1996-01-01

    A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that of movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the moveable body part through the full-shrg position of the moveable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the moveable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective moveable prosthesis device and its sub-prosthesis.

  16. Operation control device for nuclear power plants

    International Nuclear Information System (INIS)

    Suto, Osamu.

    1982-01-01

    Purpose: To render the controlling functions of a central control console more centralized by constituting the operation controls for a nuclear power plant with computer systems having substantially independent functions such as those of plant monitor controls, reactor monitor management and CRT display and decreasing interactions between each of the systems. Constitution: An input/output device for the input of process data for a nuclear power plant and indication data for a plant control console is connected to a plant supervisory and control computer system and a display computer system, the plant supervisory control computer system and a reactor and management computer system are connected with a CRT display control device, a printer and a CRT display input/output device, and the display computer system is connected with the CRT display control device and the CRT display unit on the central control console, whereby process input can be processed and displayed at high speed. (Yoshino, Y.)

  17. Polarized-photon frequency filter in double-ferromagnetic barrier silicene junction

    Energy Technology Data Exchange (ETDEWEB)

    Chantngarm, Peerasak; Yamada, Kou [Domain of Mechanical Science and Technology, Graduate School of Science and Technology, Gunma University, Gunma (Japan); Soodchomshom, Bumned, E-mail: Bumned@hotmail.com [Department of Physics, Faculty of Science, Kasetsart University Bangkok 10900 (Thailand)

    2017-05-01

    We present an analytical study of effects from circularly polarized light illumination on controlling spin-valley currents in a dual ferromagnetic-gated silicene. Two different perpendicular electric fields are applied into the ferromagnetic (FM) gates and the photo-irradiated normal (NM) area between the gates. One parallel (P) and two anti-parallel (AP) configurations of exchange fields applied along with chemical potential to the gates are used in this investigation. Interestingly, the studied junction might give rise to polarized-photon frequency filter. Spin-valley filtering can be achieved at the off-resonant frequency region with appropriate direction of electric fields and the configuration of exchange fields (AP-1 or AP-2). Under the photo irradiation, this study found that tunneling magnetoresistance (TMR) is controllable to achieve giant magnetoresistance (GMR) by adjusting electric fields or chemical potentials. Our study suggests the potential of photo-sensing devices in spin-valleytronics realm. - Highlights: • Photon-frequency control of spin-valley currents in silicene is investigated. • Complete photon frequency filtering effect is predicted. • Giant magnetoresistance induced by polarized photon is also found. • The junction is applicable for photo-sensing devices in spin-valleytronics realm.

  18. A controller for controlling a group of lighting devices and a method thereof

    OpenAIRE

    2017-01-01

    A controller (100) for controlling a group (110) of lighting devices (112, 114) is disclosed. The group (110) comprises a first lighting device (112) and a second lighting device (114). The controller (100) comprises a communication unit (102) for communicating with the first and second lighting devices (112, 114), and for receiving a first current light setting of the first lighting device (112) and a second current light setting of the second lighting device (114). The controller (100) furt...

  19. Composition controlled spin polarization in Co{sub 1-x}Fe{sub x}S{sub 2} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Leighton, C [Department of Chemical Engineering and Materials Science, University of Minnesota (United States); Manno, M [Department of Chemical Engineering and Materials Science, University of Minnesota (United States); Cady, A [Advanced Photon Source, Argonne National Laboratory (United States); Freeland, J W [Advanced Photon Source, Argonne National Laboratory (United States); Wang, L [Department of Chemical Engineering and Materials Science, University of Minnesota (United States); Umemoto, K [Department of Chemical Engineering and Materials Science, University of Minnesota (United States); Wentzcovitch, R M [Department of Chemical Engineering and Materials Science, University of Minnesota (United States); Chen, T Y [Department of Physics and Astronomy, Johns Hopkins University (United States); Chien, C L [Department of Physics and Astronomy, Johns Hopkins University (United States); Kuhns, P L [National High Magnetic Field Laboratory, Florida State University (United States); Hoch, M J R [National High Magnetic Field Laboratory, Florida State University (United States); Reyes, A P [National High Magnetic Field Laboratory, Florida State University (United States); Moulton, W G [National High Magnetic Field Laboratory, Florida State University (United States); Dahlberg, E D [School of Physics and Astronomy, University of Minnesota (United States); Checkelsky, J [Physics Department, Harvey Mudd College (United States); Eckert, J [Physics Department, Harvey Mudd College (United States)

    2007-08-08

    The transition metal (TM) chalcogenides of the form TMX{sub 2} (X = S or Se) have been studied for decades due to their interesting electronic and magnetic properties such as metamagnetism and metal-insulator transitions. In particular, the Co{sub 1-x}Fe{sub x}S{sub 2} alloys were the subject of investigation in the 1970s due to general interest in itinerant ferromagnetism. In recent years (2000-present) it has been shown, both by electronic structure calculations and detailed experimental investigations, that Co{sub 1-x}Fe{sub x}S{sub 2} is a model system for the investigation of highly spin polarized ferromagnetism. The radically different electronic properties of the two endpoint compounds (CoS{sub 2} is a narrow bandwidth ferromagnetic metal, while FeS{sub 2} is a diamagnetic semiconductor), in a system forming a substitutional solid solution allows for composition control of the Fermi level relative to the spin split bands, and therefore composition-controlled conduction electron spin polarization. In essence, the recent work has shown that the concept of 'band engineering' can be applied to half-metallic ferromagnets and that high spin polarization can be deliberately engineered. Experiments reveal tunability in both sign and magnitude of the spin polarization at the Fermi level, with maximum values obtained to date of 85% at low temperatures. In this paper we review the properties of Co{sub 1-x}Fe{sub x}S{sub 2} alloys, with an emphasis on properties of relevance to half-metallicity. Crystal structure, electronic structure, synthesis, magnetic properties, transport properties, direct probes of the spin polarization, and measurements of the total density of states at the Fermi level are all discussed. We conclude with a discussion of the factors that influence, or even limit, the spin polarization, along with a discussion of opportunities and problems for future investigation, particularly with regard to fundamental studies of spintronic devices.

  20. Testing device for control rod drives

    International Nuclear Information System (INIS)

    Hayakawa, Toshifumi.

    1992-01-01

    A testing device for control rod drives comprises a logic measuring means for measuring an output signal from a control rod drive logic generation circuit, a control means for judging the operation state of a control rod and a man machine interface means for outputting the result of the judgement. A driving instruction outputted from the control rod operation device is always monitored by the control means, and if the operation instruction is stopped, a testing signal is outputted to the control rod control device to simulate a control rod operation. In this case, the output signal of the control rod drive logic generation circuit is held in a control rod drive memory means and intaken into a logic analysis means for measurement and an abnormality is judged by the control means. The stopping of the control rod drive instruction is monitored and the operation abnormality of the control rod is judged, to mitigate the burden of an operator. Further, the operation of the control rod drive logic generation circuit can be confirmed even during a nuclear plant operation by holding the control rod drive instruction thereby enabling to improve maintenance efficiency. (N.H.)

  1. Development and demonstration of optical polarization controller; Hikari henpa seigyo sochi no kaihatsu to jissho

    Energy Technology Data Exchange (ETDEWEB)

    Kurono, M. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1997-04-01

    If fiber transmission light can be controlled in a stabilized polarization state, realization of coherent optical communication is anticipated. In the case of adopting it to OPGW, however, it is necessary to compensate high speed polarization variation caused by lightning strike. But this was difficult in the conventional method. Accordingly, a high speed polarization control method was proposed which uses an electric effect of lithium niobate (LN) crystals. In the study, a polarization control unit was manufactured based on the method proposed and the performance was demonstrated. As a result of measuring output light with input light changed in every state of polarization, the object horizontal polarization component obtained a stabilized light intensity at {+-}0.1dB, and a light intensity of the component slipped out of the horizontal polarization was suppressed under -20dB. To cope with the polarization variation by lightning strike, it is necessary to make the control delay 10{mu}sec or below, and improvement in processing unit, etc. may make it possible since LN crystals respond below 1{mu}sec. High speed control of the infinitely continuing arbitrary polarization variation became possible. 14 refs., 19 figs.

  2. Diffraction limited focusing with controllable arbitrary three-dimensional polarization

    International Nuclear Information System (INIS)

    Chen, Weibin; Zhan, Qiwen

    2010-01-01

    We propose a new approach that enables full control over the three-dimensional state of polarization and the field distribution near the focus of a high numerical aperture objective lens. By combining the electric dipole radiation and a vectorial diffraction method, the input field at the pupil plane for generating arbitrary three-dimensionally oriented linear polarization at the focal point with a diffraction limited spot size is found analytically by solving the inverse problem. Arbitrary three-dimensional elliptical polarization can be obtained by introducing a second electric dipole oriented in the orthogonal plane with appropriate amplitude and phase differences

  3. Reactor core control device

    International Nuclear Information System (INIS)

    Sano, Hiroki

    1998-01-01

    The present invention provides a reactor core control device, in which switching from a manual operation to an automatic operation, and the control for the parameter of an automatic operation device are facilitated. Namely, the hysteresis of the control for the operation parameter by an manual operation input means is stored. The hysteresis of the control for the operation parameter is collected. The state of the reactor core simulated by an operation control to which the collected operation parameters are manually inputted is determined as an input of the reactor core state to the automatic input means. The record of operation upon manual operation is stored as a hysteresis of control for the operation parameter, but the hysteresis information is not only the result of manual operation of the operation parameter. This is results of operation conducted by a skilled operator who judge the state of the reactor core to be optimum. Accordingly, it involves information relevant to the reactor core state. Then, it is considered that the optimum automatic operation is not deviated greatly from the manual operation. (I.S.)

  4. Remotely Interrogated Passive Polarizing Dosimeter (RIPPeD).

    Energy Technology Data Exchange (ETDEWEB)

    Kemme, Shanalyn A.; Buller, Daniel L.; Dirk, Shawn M.; Boye, Robert R.; Samora, Sally; Washburn, Cody M.; Wheeler, David Roger

    2008-09-01

    Conductive polymers have become an extremely useful class of materials for many optical applications. We have developed an electrochemical growth method for depositing highly conductive ({approx}100 S/cm) polypyrrole. Additionally, we have adapted advanced fabrication methods for use with the polypyrrole resulting in gratings with submicron features. This conductive polymer micro-wire grid provides an optical polarizer with unique properties. When the polymer is exposed to ionizing radiation, its conductivity is affected and the polarization properties of the device, specifically the extinction ratio, change in a corresponding manner. This change in polarization properties can be determined by optically interrogating the device, possibly from a remote location. The result is a passive radiation-sensitive sensor with very low optical visibility. The ability to interrogate the device from a safe standoff distance provides a device useful in potentially dangerous environments. Also, the passive nature of the device make it applicable in applications where external power is not available. We will review the polymer deposition, fabrication methods and device design and modeling. The characterization of the polymer's sensitivity to ionizing radiation and optical testing of infrared polarizers before and after irradiation will also be presented. These experimental results will highlight the usefulness of the conductive infrared polarizer to many security and monitoring applications.

  5. Remotely Interrogated Passive Polarizing Dosimeter (RIPPeD)

    International Nuclear Information System (INIS)

    Kemme, Shanalyn A.; Buller, Daniel L.; Dirk, Shawn M.; Boye, Robert R.; Samora, Sally; Washburn, Cody M.; Wheeler, David Roger

    2008-01-01

    Conductive polymers have become an extremely useful class of materials for many optical applications. We have developed an electrochemical growth method for depositing highly conductive (∼100 S/cm) polypyrrole. Additionally, we have adapted advanced fabrication methods for use with the polypyrrole resulting in gratings with submicron features. This conductive polymer micro-wire grid provides an optical polarizer with unique properties. When the polymer is exposed to ionizing radiation, its conductivity is affected and the polarization properties of the device, specifically the extinction ratio, change in a corresponding manner. This change in polarization properties can be determined by optically interrogating the device, possibly from a remote location. The result is a passive radiation-sensitive sensor with very low optical visibility. The ability to interrogate the device from a safe standoff distance provides a device useful in potentially dangerous environments. Also, the passive nature of the device make it applicable in applications where external power is not available. We will review the polymer deposition, fabrication methods and device design and modeling. The characterization of the polymer's sensitivity to ionizing radiation and optical testing of infrared polarizers before and after irradiation will also be presented. These experimental results will highlight the usefulness of the conductive infrared polarizer to many security and monitoring applications

  6. Circular polarization in a non-magnetic resonant tunneling device

    Directory of Open Access Journals (Sweden)

    Airey Robert

    2011-01-01

    Full Text Available Abstract We have investigated the polarization-resolved photoluminescence (PL in an asymmetric n-type GaAs/AlAs/GaAlAs resonant tunneling diode under magnetic field parallel to the tunnel current. The quantum well (QW PL presents strong circular polarization (values up to -70% at 19 T. The optical emission from GaAs contact layers shows evidence of highly spin-polarized two-dimensional electron and hole gases which affects the spin polarization of carriers in the QW. However, the circular polarization degree in the QW also depends on various other parameters, including the g-factors of the different layers, the density of carriers along the structure, and the Zeeman and Rashba effects.

  7. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ziming, E-mail: wangziming@jlu.edu.cn [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Zhao Xin; Xu Xu; Wu Lijie; Su Rui; Zhao Yajing; Jiang Chengfei; Zhang Hanqi [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Ma Qiang [Chinese Academy of Inspection and Quarantine, Beijing 100123 (China); Lu Chunmei [College of Technology Center, Jilin Entry-Exit Inspection and Quarantine Bureau, Changchun 130062 (China); Dong Deming [College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)

    2013-01-14

    Highlights: Black-Right-Pointing-Pointer An absorbing microwave {mu}-SPE device packed with activated carbon was used. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to enrich the analytes. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to heat samples directly. Black-Right-Pointing-Pointer MAE-{mu}-SPE was applied to the extraction of OPPs with non-polar solvent only. - Abstract: A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction ({mu}-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave {mu}-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in {mu}-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave {mu}-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 Degree-Sign C for 10 min. The extracts obtained by MAE-{mu}-SPE were directly analyzed by GC-MS without any clean-up process. The recoveries were in the range of 93.5-104.6%, and the relative standard deviations were lower than 8.7%.

  8. Control Strategies for Arrays of Wave Energy Devices

    OpenAIRE

    Westphalen, J; Bacelli, G; Balitsky, P; Ringwood, John

    2011-01-01

    In this paper, we investigate the differences between two control strategies for a two-device linear array of wave energy converters (WEC) for device spacings of 4 to 80 times the device diameter. The WECs operate in heave only and are controlled in real time. The control strategies, called the independent device and global array control, estimate the excitation forces and calculate the optimum vertical velocity trajectory and reactive power take off force to achieve the ...

  9. Polarization control of spontaneous emission for rapid quantum-state initialization

    Science.gov (United States)

    DiLoreto, C. S.; Rangan, C.

    2017-04-01

    We propose an efficient method to selectively enhance the spontaneous emission rate of a quantum system by changing the polarization of an incident control field, and exploiting the polarization dependence of the system's spontaneous emission rate. This differs from the usual Purcell enhancement of spontaneous emission rates as it can be selectively turned on and off. Using a three-level Λ system in a quantum dot placed in between two silver nanoparticles and a linearly polarized, monochromatic driving field, we present a protocol for rapid quantum state initialization, while maintaining long coherence times for control operations. This process increases the overall amount of time that a quantum system can be effectively utilized for quantum operations, and presents a key advance in quantum computing.

  10. Plasma position and shape control device for thermonuclear device

    International Nuclear Information System (INIS)

    Takeuchi, Kazuhiro; Abe, Mitsushi; Kinoshita, Shigemi.

    1993-01-01

    A plasma position and shape control system is constituted with a measuring device, a quenching probability calculation section and a control calculation section. A quenching probability is calculated in the quenching probability calculation section by using a measuring data on temperature, electric current and magnetic field of superconductive coils, based on a margin upto a limit value. The control calculation section selects a control method which decreases applied voltage or current instruction value as the quenching probability of the coils is higher. Since the quenching probability of the superconductive coils can be forecast and a state of low quenching danger can be selected, the safety of the device is improved. When the quenching danger is allowed to a predetermined value, a wide operation region can be provided. (N.H.)

  11. Directed Assembly of Janus Cylinders by Controlling the Solvent Polarity.

    Science.gov (United States)

    Kim, Jongmin; Choi, Chang-Hyung; Yeom, Su-Jin; Eom, Naye; Kang, Kyoung-Ku; Lee, Chang-Soo

    2017-08-01

    This study demonstrates the possibility of controlling the directed self-assembly of microsized Janus cylinders by changing the solvent polarity of the assembly media. Experimental results are analyzed and theoretical calculations of the free energy of adhesion (ΔG ad ) are performed to elucidate the underlying basic principles and investigate the effects of the solvent on the self-assembled structures. This approach will pave a predictive route for controlling the structures of assembly depending on the solvent polarity. In particular, we find that a binary solvent system with precisely controlled polarity induces directional assembly of the microsized Janus cylinders. Thus, the formation of two-dimensional (2D) and three-dimensional (3D) assembled clusters can be reliably tuned by controlling the numbers of constituent Janus cylinders in a binary solvent system. Finally, this approach is expanded to stepwise assembly, which forms unique microstructures via secondary growth of primary seed clusters formed by the Janus cylinders. We envision that this investigation is highly promising for the construction of desired superstructures using a wide variety of polymeric Janus microparticles with chemical and physical multicompartments.

  12. Ultra-wideband reflective polarization converter based on anisotropic metasurface

    International Nuclear Information System (INIS)

    Wu Jia-Liang; Lin Bao-Qin; Da Xin-Yu

    2016-01-01

    In this paper, we propose an ultra-wideband reflective linear cross-polarization converter based on anisotropic metasurface. Its unit cell is composed of a square-shaped resonator with intersectant diagonal and metallic ground sheet separated by dielectric substrate. Simulated results show that the converter can generate resonances at four frequencies under normal incident electromagnetic (EM) wave, leading to the bandwidth expansion of cross-polarization reflection. For verification, the designed polarization converter is fabricated and measured. The measured and simulated results agree well with each other, showing that the fabricated converter can convert x - or y -polarized incident wave into its cross polarized wave in a frequency range from 7.57 GHz to 20.46 GHz with a relative bandwidth of 91.2%, and the polarization conversion efficiency is greater than 90%. The proposed polarization converter has a simple geometry but an ultra wideband compared with the published designs, and hence possesses potential applications in novel polarization-control devices. (paper)

  13. Remote control of Alfven eigenmode sensing system on the large helical device

    Energy Technology Data Exchange (ETDEWEB)

    Ito, T. [Nagoya University, Department of Energy Engineering and Science, Furo-cho, Chikusa-ku, Nagoya City, Aichi (Japan)], E-mail: ito.takafumi@lhd.nifs.ac.jp; Toi, K. [Nagoya University, Department of Energy Engineering and Science, Furo-cho, Chikusa-ku, Nagoya City, Aichi (Japan); National Institute for Fusion Science, 322-6 Oroshicho, Toki, Gifu (Japan); Matsunaga, G. [Japan Atomic Energy Agency, 801-1 Mukouyama, Naka, Ibaraki 311-0193 (Japan)

    2008-04-15

    An active sensing system of Alfven eigenmodes (AEs), which consists of a set of toroidally distributed loop antennas and several bi-polar power supplies, has been developed in the large helical device (LHD). The power supplies are controlled with a function generator receiving a control pattern of antenna current and the driving frequency from a personal computer (PC) in an LHD control room. This sensing method is based on the analysis of the frequency dependence of a transfer function that is derived by the ratio of the Fourier-transformed magnetic probe signal ('plasma response') to antenna current one ('exciter signal'). Typically, the driving frequency of the antenna current is swept linearly in time from 10 kHz to 500 kHz for 2 s in the LHD experiment. The sensing system is fully controlled through Ethernet LAN with easy extendable GUI. Configuration and control scheme of the active sensing system of AEs are presented in this paper. An initial result of the system operation is also described.

  14. Low-cost fabrication and polar-dependent switching uniformity of memory devices using alumina interfacial layer and Ag nanoparticle monolayer

    Directory of Open Access Journals (Sweden)

    Peng Xia

    2017-11-01

    Full Text Available A facile and low-cost process was developed for fabricating write-once-read-many-times (WORM Cu/Ag NPs/Alumina/Al memory devices, where the alumina passivation layer formed naturally in air at room temperature, whereas the Ag nanoparticle monolayer was in situ prepared through thermal annealing of a 4.5 nm Ag film in air at 150°C. The devices exhibit irreversible transition from initial high resistance (OFF state to low resistance (ON state, with ON/OFF ratio of 107, indicating the introduction of Ag nanoparticle monolayer greatly improves ON/OFF ratio by four orders of magnitude. The uniformity of threshold voltages exhibits a polar-dependent behavior, and a narrow range of threshold voltages of 0.40 V among individual devices was achieved upon the forward voltage. The memory device can be regarded as two switching units connected in series. The uniform alumina interfacial layer and the non-uniform distribution of local electric fields originated from Ag nanoparticles might be responsible for excellent switching uniformity. Since silver ions in active layer can act as fast ion conductor, a plausible mechanism relating to the formation of filaments sequentially among the two switching units connected in series is suggested for the polar-dependent switching behavior. Furthermore, we demonstrate both alumina layer and Ag NPs monolayer play essential roles in improving switching parameters based on comparative experiments.

  15. Low-cost fabrication and polar-dependent switching uniformity of memory devices using alumina interfacial layer and Ag nanoparticle monolayer

    Science.gov (United States)

    Xia, Peng; Li, Luman; Wang, Pengfei; Gan, Ying; Xu, Wei

    2017-11-01

    A facile and low-cost process was developed for fabricating write-once-read-many-times (WORM) Cu/Ag NPs/Alumina/Al memory devices, where the alumina passivation layer formed naturally in air at room temperature, whereas the Ag nanoparticle monolayer was in situ prepared through thermal annealing of a 4.5 nm Ag film in air at 150°C. The devices exhibit irreversible transition from initial high resistance (OFF) state to low resistance (ON) state, with ON/OFF ratio of 107, indicating the introduction of Ag nanoparticle monolayer greatly improves ON/OFF ratio by four orders of magnitude. The uniformity of threshold voltages exhibits a polar-dependent behavior, and a narrow range of threshold voltages of 0.40 V among individual devices was achieved upon the forward voltage. The memory device can be regarded as two switching units connected in series. The uniform alumina interfacial layer and the non-uniform distribution of local electric fields originated from Ag nanoparticles might be responsible for excellent switching uniformity. Since silver ions in active layer can act as fast ion conductor, a plausible mechanism relating to the formation of filaments sequentially among the two switching units connected in series is suggested for the polar-dependent switching behavior. Furthermore, we demonstrate both alumina layer and Ag NPs monolayer play essential roles in improving switching parameters based on comparative experiments.

  16. Polarization controlled UV writing of bragg gratings

    DEFF Research Database (Denmark)

    Jensen, Jesper Bo Damm; Plougmann, Nikolai; Deyerl, Hans-Jürgen

    2002-01-01

    In conclusion the polarization control method is superior to any double scan method since it allows much more flexible apodization and inclusion of phase shifts, and since only one exposure is required. In many cases the method performs just as well as the most sophisticated phase mask jitter met...

  17. Invited Article: An active terahertz polarization converter employing vanadium dioxide and a metal wire grating in total internal reflection geometry

    Science.gov (United States)

    Liu, Xudong; Chen, Xuequan; Parrott, Edward P. J.; Han, Chunrui; Humbert, Georges; Crunteanu, Aurelian; Pickwell-MacPherson, Emma

    2018-05-01

    Active broadband terahertz (THz) polarization manipulation devices are challenging to realize, but also of great demand in broadband terahertz systems. Vanadium dioxide (VO2) shows a promising phase transition for active control of THz waves and provides broadband polarization characteristics when integrated within grating-type structures. We creatively combine a VO2-based grating structure with a total internal reflection (TIR) geometry providing a novel interaction mechanism between the electromagnetic waves and the device, to realize a powerful active broadband THz polarization-controlling device. The device is based on a Si-substrate coated with a VO2 layer and a metal grating structure on top, attached to a prism for generating the TIR condition on the Si-VO2-grating interface. The grating is connected to electrodes for electrically switching the VO2 between its insulating and conducting phases. By properly selecting the incident angle of the THz waves, the grating direction, and the incident polarization state, we first achieved a broadband intensity modulator under a fused silica prism with an average modulation depth of 99.75% in the 0.2-1.1 THz region. Additionally, we realized an active ultra-broadband quarter-wave converter under a Si prism that can be switched between a 45° linear rotator and a quarter wave converter in the 0.8-1.5 THz region. This is the first demonstration of an active quarter-wave converter with ultra-broad bandwidth performance. Our work shows a highly flexible and multifunctional polarization-controlling device for broadband THz applications.

  18. Polarization-tuned diode behaviour in multiferroic BiFeO3 thin films

    KAUST Repository

    Yao, Yingbang

    2012-12-28

    Asymmetric rectifying I-V behaviour of multiferroic BiFeO3 (BFO) thin films grown on transparent ITO-coated glass was quantitatively studied as a function of ferroelectric polarization. Different polarized states were established by unipolar or bipolar poling with various applied electric fields. The effects of polarization relaxation and fatigue on the currents were also investigated. We found that the conduction currents and the associated rectifications were controlled by the amplitude and direction of the polarization. We clearly observed the linear dependence of the current on the polarization. It is suggested that the space-charge-limited conduction and the charge injection at the Schottky interface between the film and the electrodes dominate the current. The electrically controlled rectifying behaviour observed in this study may be useful in nonvolatile resistance memory devices or tunable diodes. © 2013 IOP Publishing Ltd.

  19. Prickle isoforms control the direction of tissue polarity by microtubule independent and dependent mechanisms

    Directory of Open Access Journals (Sweden)

    Katherine A. Sharp

    2016-03-01

    Full Text Available Planar cell polarity signaling directs the polarization of cells within the plane of many epithelia. While these tissues exhibit asymmetric localization of a set of core module proteins, in Drosophila, more than one mechanism links the direction of core module polarization to the tissue axes. One signaling system establishes a polarity bias in the parallel, apical microtubules upon which vesicles containing core proteins traffic. Swapping expression of the differentially expressed Prickle isoforms, Prickle and Spiny-legs, reverses the direction of core module polarization. Studies in the proximal wing and the anterior abdomen indicated that this results from their differential control of microtubule polarity. Prickle and Spiny-legs also control the direction of polarization in the distal wing (D-wing and the posterior abdomen (P-abd. We report here that this occurs without affecting microtubule polarity in these tissues. The direction of polarity in the D-wing is therefore likely determined by a novel mechanism independent of microtubule polarity. In the P-abd, Prickle and Spiny-legs interpret at least two directional cues through a microtubule-polarity-independent mechanism.

  20. FACTS device control strategy using PMU

    Directory of Open Access Journals (Sweden)

    Mohd Tauseef Khan

    2016-09-01

    Full Text Available The laying and commissioning of new transmission line is very difficult due to socio-economic problems, like environmental clearances, right of way, etc. Therefore, there is an emphasis on better utilization of available transmission infrastructure. FACTS devices can provide reactive power compensation, transmission capability enhancement, and voltage and stability improvement. FACTS devices operate under the command of system operator who analyses its demand by the data acquired through traditional SCADA system, state estimation algorithms and PMUs. SCADA together with PMU give accurate information about the operational state of power system. This paper proposes a scheme to automate the FACTS devices in collaboration with PMUs in a more efficient way. Highly precised data from PMUs can be fed to intelligent controllers for effective analyzing and automating the FACTS device through control command. Thus, this combination can provide real time control of reactive power, together with enhancement of power handling capability and stability improvement.

  1. Spin-Polarized Tunneling through Chemical Vapor Deposited Multilayer Molybdenum Disulfide.

    Science.gov (United States)

    Dankert, André; Pashaei, Parham; Kamalakar, M Venkata; Gaur, Anand P S; Sahoo, Satyaprakash; Rungger, Ivan; Narayan, Awadhesh; Dolui, Kapildeb; Hoque, Md Anamul; Patel, Ram Shanker; de Jong, Michel P; Katiyar, Ram S; Sanvito, Stefano; Dash, Saroj P

    2017-06-27

    The two-dimensional (2D) semiconductor molybdenum disulfide (MoS 2 ) has attracted widespread attention for its extraordinary electrical-, optical-, spin-, and valley-related properties. Here, we report on spin-polarized tunneling through chemical vapor deposited multilayer MoS 2 (∼7 nm) at room temperature in a vertically fabricated spin-valve device. A tunnel magnetoresistance (TMR) of 0.5-2% has been observed, corresponding to spin polarization of 5-10% in the measured temperature range of 300-75 K. First-principles calculations for ideal junctions result in a TMR up to 8% and a spin polarization of 26%. The detailed measurements at different temperature, bias voltages, and density functional theory calculations provide information about spin transport mechanisms in vertical multilayer MoS 2 spin-valve devices. These findings form a platform for exploring spin functionalities in 2D semiconductors and understanding the basic phenomena that control their performance.

  2. DEVICE FOR CONTROL OF OXYGEN PARTIAL PRESSURE

    Science.gov (United States)

    Bradner, H.; Gordon, H.S.

    1957-12-24

    A device is described that can sense changes in oxygen partial pressure and cause a corresponding mechanical displacement sufficient to actuate meters, valves and similar devices. A piston and cylinder arrangement contains a charge of crystalline metal chelate pellets which have the peculiar property of responding to variations in the oxygen content of the ambient atmosphere by undergoing a change in dimension. A lever system amplifies the relative displacement of the piston in the cylinder, and actuates the controlled valving device. This partial pressure oxygen sensing device is useful in controlled chemical reactions or in respiratory devices such as the oxygen demand meters for high altitude aircraft.

  3. Multiport optical circulator by using polarizing beam splitter cubes as spatial walk-off polarizers.

    Science.gov (United States)

    Chen, Jing-Heng; Chen, Kun-Huang; Lin, Jiun-You; Hsieh, Hsiang-Yung

    2010-03-10

    Optical circulators are necessary passive devices applied in optical communication systems. In the design of optical circulators, the implementation of the function of spatial walk-off polarizers is a key technique that significantly influences the performance and cost of a device. This paper proposes a design of a multiport optical circulator by using polarizing beam splitter cubes as spatial walk-off polarizers. To show the feasibility of the design, a prototype of a six-port optical circulator was fabricated. The insertion losses are 0.94-1.49 dB, the isolations are 25-51 dB, and return losses are 27.72 dB.

  4. Instrumentation to handle thermal polarized neutron beams

    NARCIS (Netherlands)

    Kraan, W.H.

    2004-01-01

    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

  5. Dual polarized receiving steering antenna array for measurement of ultrawideband pulse polarization structure

    Energy Technology Data Exchange (ETDEWEB)

    Balzovsky, E. V.; Buyanov, Yu. I.; Koshelev, V. I., E-mail: koshelev@lhfe.hcei.tsc.ru; Nekrasov, E. S. [Institute of High Current Electronics SB RAS, IHCE SB RAS, Tomsk 634055 (Russian Federation)

    2016-03-15

    To measure simultaneously two orthogonal components of the electromagnetic field of nano- and subnano-second duration, an antenna array has been developed. The antenna elements of the array are the crossed dipoles of dimension 5 × 5 cm. The arms of the dipoles are connected to the active four-pole devices to compensate the frequency response variations of a short dipole in the frequency band ranging from 0.4 to 4 GHz. The dipoles have superimposed phase centers allowing measuring the polarization structure of the field in different directions. The developed antenna array is the linear one containing four elements. The pattern maximum position is controlled by means of the switched ultrawideband true time delay lines. Discrete steering in seven directions in the range from −40° to +40° has been realized. The error at setting the pattern maximum position is less than 4°. The isolation of the polarization exceeds 29 dB in the direction orthogonal to the array axis and in the whole steering range it exceeds 23 dB. Measurement results of the polarization structure of radiated and scattered pulses with different polarization are presented as well.

  6. Brain-controlled body movement assistance devices and methods

    Energy Technology Data Exchange (ETDEWEB)

    Leuthardt, Eric C.; Love, Lonnie J.; Coker, Rob; Moran, Daniel W.

    2017-01-10

    Methods, devices, systems, and apparatus, including computer programs encoded on a computer storage medium, for brain-controlled body movement assistance devices. In one aspect, a device includes a brain-controlled body movement assistance device with a brain-computer interface (BCI) component adapted to be mounted to a user, a body movement assistance component operably connected to the BCI component and adapted to be worn by the user, and a feedback mechanism provided in connection with at least one of the BCI component and the body movement assistance component, the feedback mechanism being configured to output information relating to a usage session of the brain-controlled body movement assistance device.

  7. Reactor power control device

    International Nuclear Information System (INIS)

    Ishii, Yoshihiko; Arita, Setsuo; Miyamoto, Yoshiyuki; Fukazawa, Yukihisa; Ishii, Kazuhiko

    1998-01-01

    The present invention provides a reactor power control device capable of enhancing an operation efficiency while keeping high reliability and safety in a BWR type nuclear power plant. Namely, the device of the present invention comprises (1) a means for inputting a set value of a generator power and a set value of a reactor power, (2) a means for controlling the reactor power to either smaller one of the reactor power corresponding to the set value of the generator power and the set value of the reactor power. With such procedures, even if the nuclear power plant is set so as to operate it to make the reactor power 100%, when the generator power reaches the upper limit, the reactor power is controlled with a preference given to the upper limit value of the generator power. Accordingly, safety and reliability are not deteriorated. The operation efficiency of the plant can be improved. (I.S.)

  8. Plasma control device

    International Nuclear Information System (INIS)

    Matsutomi, Akiyoshi.

    1995-01-01

    Plasma position and shape estimation values are outputted based on measured values of coil current. When the measured values of the position and the shape are judged to be abnormal, position and shape estimation values estimated by a plasma position and shape estimation means are outputted as position and shape feed back values to a plasma position and shape control means instead of the position and shape measured values. Since only a portion of the abnormal position and shape measured values may also be replaced with the position and shape estimation values, errors in the plasma position and shape feed back values can be reduced as a whole. In addition, even if the position and shape measured values are abnormal or if they can not be measured, plasma control can be continued by alternative position and shape estimation values, thereby enabling to avoid interruption of plasma control. Since the position and shape estimation values are obtained not only with the measured values of coil current but also with the position and shape estimation values, the accuracy is improved. Further, noises superposed on the position and shape measured values are filtered, and the device is stabilized compared with a prior art device. (N.H.)

  9. A controller for controlling a group of lighting devices and a method thereof

    NARCIS (Netherlands)

    2017-01-01

    A controller (100) for controlling a group (110) of lighting devices (112, 114) is disclosed. The group (110) comprises a first lighting device (112) and a second lighting device (114). The controller (100) comprises a communication unit (102) for communicating with the first and second lighting

  10. Controlled release of cytokines using silk-biomaterials for macrophage polarization.

    Science.gov (United States)

    Reeves, Andrew R D; Spiller, Kara L; Freytes, Donald O; Vunjak-Novakovic, Gordana; Kaplan, David L

    2015-12-01

    Polarization of macrophages into an inflammatory (M1) or anti-inflammatory (M2) phenotype is important for clearing pathogens and wound repair, however chronic activation of either type of macrophage has been implicated in several diseases. Methods to locally control the polarization of macrophages is of great interest for biomedical implants and tissue engineering. To that end, silk protein was used to form biopolymer films that release either IFN-γ or IL-4 to control the polarization of macrophages. Modulation of the solubility of the silk films through regulation of β-sheet (crystalline) content enabled a short-term release (4-8 h) of either cytokine, with smaller amounts released out to 24 h. Altering the solubility of the films was accomplished by varying the time that the films were exposed to water vapor. The released IFN-γ or IL-4 induced polarization of THP-1 derived macrophages into the M1 or M2 phenotypes, respectively. The silk biomaterials were able to release enough IFN-γ or IL-4 to repolarize the macrophage from M1 to M2 and vice versa, demonstrating the well-established plasticity of macrophages. High β-sheet content films that are not soluble and do not release the trapped cytokines were also able to polarize macrophages that adhered to the surface through degradation of the silk protein. Chemically conjugating IFN-γ to silk films through disulfide bonds allowed for longer-term release to 10 days. The release of covalently attached IFN-γ from the films was also able to polarize M1 macrophages in vitro. Thus, the strategy described here offers new approaches to utilizing biomaterials for directing the polarization of macrophages. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. FEL polarization control studies on Dalian coherent light source

    International Nuclear Information System (INIS)

    Zhang Tong; Deng Haixiao; Wang Dong; Zhao Zhentang; Zhang Weiqing; Wu Guorong; Dai Dongxu; Yang Xueming

    2013-01-01

    The polarization switch of a free-electron laser (FEL) is of great importance to the user scientific community. In this paper, we investigate the generation of controllable polarization FEL from two well-known approaches for Dalian coherent light source, i.e., crossed planar undulator and elliptical permanent undulator. In order to perform a fair comparative study, a one-dimensional time-dependent FEL code has been developed, in which the imperfection effects of an elliptical permanent undulator are taken into account. Comprehensive simulation results indicate that the residual beam energy chirp and the intrinsic FEL gain may contribute to the degradation of the polarization performance for the crossed planar undulator. The elliptical permanent undulator is not very sensitive to the undulator errors and beam imperfections. Meanwhile, with proper configurations of the main planar undulators and additional elliptical permanent undulator section, circular polarized FEL with pulse energy exceeding 100 μJ could be achieved at Dalian coherent light source. (authors)

  12. Ultra-wideband reflective polarization converter based on anisotropic metasurface

    Science.gov (United States)

    Wu, Jia-Liang; Lin, Bao-Qin; Da, Xin-Yu

    2016-08-01

    In this paper, we propose an ultra-wideband reflective linear cross-polarization converter based on anisotropic metasurface. Its unit cell is composed of a square-shaped resonator with intersectant diagonal and metallic ground sheet separated by dielectric substrate. Simulated results show that the converter can generate resonances at four frequencies under normal incident electromagnetic (EM) wave, leading to the bandwidth expansion of cross-polarization reflection. For verification, the designed polarization converter is fabricated and measured. The measured and simulated results agree well with each other, showing that the fabricated converter can convert x- or y-polarized incident wave into its cross polarized wave in a frequency range from 7.57 GHz to 20.46 GHz with a relative bandwidth of 91.2%, and the polarization conversion efficiency is greater than 90%. The proposed polarization converter has a simple geometry but an ultra wideband compared with the published designs, and hence possesses potential applications in novel polarization-control devices. Project supported by the National Natural Science Foundation of China (Grant Nos. 61471387, 61271250, and 61571460).

  13. Polarization-induced hole doping in N-polar III-nitride LED grown by metalorganic chemical vapor deposition

    KAUST Repository

    Yan, Long

    2018-05-03

    Polarization-induced doping has been shown to be effective for wide-bandgap III-nitrides. In this work, we demonstrated a significantly enhanced hole concentration via linearly grading an N-polar AlxGa1-xN (x = 0–0.3) layer grown by metal-organic chemical vapor deposition. The hole concentration increased by ∼17 times compared to that of N-polar p-GaN at 300 K. The fitting results of temperature-dependent hole concentration indicated that the holes in the graded p-AlGaN layer comprised both polarization-induced and thermally activated ones. By optimizing the growth conditions, the hole concentration was further increased to 9.0 × 1017 cm−3 in the graded AlGaN layer. The N-polar blue-violet light-emitting device with the graded p-AlGaN shows stronger electroluminescence than the one with the conventional p-GaN. The study indicates the potential of the polarization doping technique in high-performance N-polar light-emitting devices.

  14. Polarization-induced hole doping in N-polar III-nitride LED grown by metalorganic chemical vapor deposition

    KAUST Repository

    Yan, Long; Zhang, Yuantao; Han, Xu; Deng, Gaoqiang; Li, Pengchong; Yu, Ye; Chen, Liang; Li, Xiaohang; Song, Junfeng

    2018-01-01

    Polarization-induced doping has been shown to be effective for wide-bandgap III-nitrides. In this work, we demonstrated a significantly enhanced hole concentration via linearly grading an N-polar AlxGa1-xN (x = 0–0.3) layer grown by metal-organic chemical vapor deposition. The hole concentration increased by ∼17 times compared to that of N-polar p-GaN at 300 K. The fitting results of temperature-dependent hole concentration indicated that the holes in the graded p-AlGaN layer comprised both polarization-induced and thermally activated ones. By optimizing the growth conditions, the hole concentration was further increased to 9.0 × 1017 cm−3 in the graded AlGaN layer. The N-polar blue-violet light-emitting device with the graded p-AlGaN shows stronger electroluminescence than the one with the conventional p-GaN. The study indicates the potential of the polarization doping technique in high-performance N-polar light-emitting devices.

  15. System for remote control of underground device

    Science.gov (United States)

    Brumleve, T.D.; Hicks, M.G.; Jones, M.O.

    1975-10-21

    A system is described for remote control of an underground device, particularly a nuclear explosive. The system includes means at the surface of the ground for transmitting a seismic signal sequence through the earth having controlled and predetermined signal characteristics for initiating a selected action in the device. Additional apparatus, located with or adjacent to the underground device, produces electrical signals in response to the seismic signals received and compares these electrical signals with the predetermined signal characteristics.

  16. System for remote control of underground device

    International Nuclear Information System (INIS)

    Brumleve, T.D.; Hicks, M.G.; Jones, M.O.

    1975-01-01

    A system is described for remote control of an underground device, particularly a nuclear explosive. The system includes means at the surface of the ground for transmitting a seismic signal sequence through the earth having controlled and predetermined signal characteristics for initiating a selected action in the device. Additional apparatus, located with or adjacent to the underground device, produces electrical signals in response to the seismic signals received and compares these electrical signals with the predetermined signal characteristics

  17. Remote Monitoring of the Polarized Target's Control for E1039

    Science.gov (United States)

    Fox, David; SeaQuest Collaboration

    2017-09-01

    The 1039 experiment at FNAL will further our understanding of spin structure by measuring the contribution that sea quarks orbital angular momentum provide to overall nucleon spin. It is accepted that the valence-quarks of nucleons only provide 30% of the total nucleon spin. To study the nucleon's sea quark contribution, E1039 will use the Drell-Yan process by colliding 120 GeV un-polarized beam protons with polarized ammonia targets of hydrogen and deuterium. The asymmetric spin distributions of resulting dimuons will be measured. These asymmetries are sensitive, among other effects, to the orbital angular momentum contribution of the sea quarks. The polarized target requires a multi-stage vacuum pump located near the target. Since access to its present controls will not be possible during running, remote control and monitoring upgrades were required. A secondary control panel was purchased and tested. Information from the programmable logic controller (PLC) must be fed into our data stream to enable remote monitoring and to signal possible alarm conditions. This solution and the program created using explicit TCP/IP messaging to extract data tags from the PLC and log it within our databases will be presented. Supported by U.S. D.O.E. Medium Energy Nuclear Physics under Grant DE-FG02-03ER41243.

  18. An automatic device for charging a storage battery

    Energy Technology Data Exchange (ETDEWEB)

    Pasyukov, A A

    1984-01-01

    The purpose of the invention is to increase the service life of storage batteries (AB) through ensuring automatic protection of the device from overloads with short circuits (KZ) and from incorrect switching polarity of the storage batteries. The device contains a transformer, a rectifier, a smoothing capacitor, a trigger capacitor, a charge current control transistor, a controllable transistor, a shielding transistor, two resistors, a diode, a resistor and a voltage divider, another resistor, a reference voltage stabilitron, a resistor and another diode and the storage battery.

  19. Realizing Broadband and Invertible Linear-to-circular Polarization Converter with Ultrathin Single-layer Metasurface

    Science.gov (United States)

    Li, Zhancheng; Liu, Wenwei; Cheng, Hua; Chen, Shuqi; Tian, Jianguo

    2015-01-01

    The arbitrary control of the polarization states of light has attracted the interest of the scientific community because of the wide range of modern optical applications that such control can afford. However, conventional polarization control setups are bulky and very often operate only within a narrow wavelength range, thereby resisting optical system miniaturization and integration. Here, we present the basic theory, simulated demonstration, and in-depth analysis of a high-performance broadband and invertible linear-to-circular (LTC) polarization converter composed of a single-layer gold nanorod array with a total thickness of ~λ/70 for the near-infrared regime. This setup can transform a circularly polarized wave into a linearly polarized one or a linearly polarized wave with a wavelength-dependent electric field polarization angle into a circularly polarized one in the transmission mode. The broadband and invertible LTC polarization conversion can be attributed to the tailoring of the light interference at the subwavelength scale via the induction of the anisotropic optical resonance mode. This ultrathin single-layer metasurface relaxes the high-precision requirements of the structure parameters in general metasurfaces while retaining the polarization conversion performance. Our findings open up intriguing possibilities towards the realization of novel integrated metasurface-based photonics devices for polarization manipulation, modulation, and phase retardation. PMID:26667360

  20. Reduction of coating induced polarization aberrations by controlling the polarization state variation

    International Nuclear Information System (INIS)

    Li, Yanghui; Shen, Weidong; Zheng, Zhenrong; Zhang, Yueguang; Liu, Xu; Hao, Xiang

    2011-01-01

    The mechanism of coating induced polarization state variation is analysed by the Jones matrix. Pauli spin matrices are used to establish the relationship between coating induced polarization state variation and polarization aberrations. To reduce coating induced polarization aberrations, we propose that δ = 0 and T s = T p at arbitrary incident angle should be appended as two additional optimization goals of optical coating design when the requirements of transmittance are met. Two typical anti-reflection (AR) coatings are designed and the polarization state variation induced by them is simulated. The MTF (modulation transfer function) calculated by polarization ray tracing is applied to evaluate the polarization aberrations of the practical lithography objective system with the two AR coatings. All the obtained results show that the coating induced polarization aberrations can be reduced by optimizing the angle dependent properties of the optical coating without additional optical elements

  1. Tridodecylamine, an efficient charge control agent in non-polar media for electrophoretic inks application

    Science.gov (United States)

    Noel, Amélie; Mirbel, Déborah; Cloutet, Eric; Fleury, Guillaume; Schatz, Christophe; Navarro, Christophe; Hadziioannou, Georges; CyrilBrochon

    2018-01-01

    In order to obtain efficient electrophoretic inks, Tridodecylamine (Dod3N), has been studied as charge control agent (CCA) in a non-polar paraffin solvent (Isopar G) for various inorganic pigments (TiO2 and Fe2O3). All hydrophobic mineral oxides, i.e. treated with octyltrimethoxysilane (C8) or dodecyltrimethoxysilane (C12), were found to be negatively charged in presence of Dod3N. The electrophoretic mobilities of inorganic pigments seemed to be strongly dependent of their isoelectric point (IEP) and also of the concentration of dod3N with an optimum range between 10 and 20 mM depending on the pigments. Finally, an electrophoretic ink constituted of hydrophobic mineral oxides in presence of Dod3N was tested in a device. Its efficiency as charge control agent to negatively charge hydrophobic particles was confirmed through good optical properties and fast response time (220 ms at 200 kV m-1).

  2. Control of magnetic vortex polarity by the phase difference between voltage signals

    Science.gov (United States)

    Cui, Huanqing; Cai, Li; Yang, Xiaokuo; Wang, Sen; Zhang, Mingliang; Li, Cheng; Feng, Chaowen

    2018-02-01

    Using micromagnetic simulations, we investigate the voltage control of magnetic vortex polarity based on a designed multiferroic heterostructure that contains two separate piezoelectric films beneath a magnetostrictive nanodisk. The results show that controllable switching of vortex polarity can be achieved by proper modulation of the phase difference between two sinusoidal voltage pulses V1 and V2, which are applied to the two separate piezoelectric films, respectively. The frequencies of V1 and V2 are set at the gyrotropic eigenfrequency fG of the nanodisk, and the vortex polarity switching is completed via the nucleation-annihilation process of the vortex-antivortex pair. Our findings provide an additional effective means for ultralow power switching of the magnetic vortex, which lays the foundation for voltage-controlled vortex random access memory.

  3. Testing device for pipeline groups and control method for testing device

    International Nuclear Information System (INIS)

    Naito, Shinji; Kajiyama, Shigeru; Takahashi, Fuminobu; Tsuchida, Kenji; Tachibana, Yukio; Shigehiro, Katsuya; Mahara, Yoichi.

    1995-01-01

    The device of the present invention comprises a testing device main body disposed to a rail, a movable mechanism positioning from a reference point, a circumferential direction scanning mechanism, an axial direction scanning mechanism, a posture control mechanism, and a testing probe. Upon testing of pipelines, the detection device main body and auxiliary members are moved from a reference point previously set on a rail for numerical control toward pipelines to be tested in a state where the axial direction scanning mechanism and the testing probe are suspended in the axial direction. The testing is conducted by controlling the position of the testing probe in the axial direction of the pipeline by means of the axial direction scanning mechanism, and scanning the testing probe to the outer circumference of the pipeline along the circumferential track by way of the circumferential direction scanning mechanism. The device can be extremely reduced in the thickness, and can be moved with no interference with pipelines and other obstacles by remote operation even under such undesired condition as the pipelines being crowded, so that non-destructive testing can be conducted accurately. (N.H.)

  4. Computer control of the SMC polarized target

    International Nuclear Information System (INIS)

    Le Goff, J.M.; Azoulay, R.; Berglund, P.; Dulya, C.; Gournay, J.F.; Hayashi, N.; Kyynaeraeinen, J.; Magnon, A.; Niinikoski, T.O.; Trentalange, S.

    1995-01-01

    The SMC polarized target is controlled through VME crates driven by CPUs working under the VxWorks operating system. The CPUs are connected to a SUN workstation which provides the user interface due to a graphical package named SL-GMS. This results in user friendliness, high modularity and flexibility. The system allows the control of: (1) the superconductive solenoid and the transverse dipole: control of the power supplies; automatic reversal of the spin direction by field rotation; acquisition, display and storage of the electric and cryogenic parameters; generation of alarms; and (2) the dilution refrigerator: evaporator level control; acquisition, display and storage of ∼100 cryogenic parameters; and generation of alarms. ((orig.))

  5. N-polar GaN epitaxy and high electron mobility transistors

    International Nuclear Information System (INIS)

    Wong, Man Hoi; Keller, Stacia; Dasgupta, Nidhi Sansaptak; Denninghoff, Daniel J; Kolluri, Seshadri; Brown, David F; Lu, Jing; Fichtenbaum, Nicholas A; Ahmadi, Elaheh; DenBaars, Steven P; Speck, James S; Mishra, Umesh K; Singisetti, Uttam; Chini, Alessandro; Rajan, Siddharth

    2013-01-01

    This paper reviews the progress of N-polar (0001-bar) GaN high frequency electronics that aims at addressing the device scaling challenges faced by GaN high electron mobility transistors (HEMTs) for radio-frequency and mixed-signal applications. Device quality (Al, In, Ga)N materials for N-polar heterostructures are developed using molecular beam epitaxy and metalorganic chemical vapor deposition. The principles of polarization engineering for designing N-polar HEMT structures will be outlined. The performance, scaling behavior and challenges of microwave power devices as well as highly-scaled depletion- and enhancement-mode devices employing advanced technologies including self-aligned processes, n+ (In,Ga)N ohmic contact regrowth and high aspect ratio T-gates will be discussed. Recent research results on integrating N-polar GaN with Si for prospective novel applications will also be summarized. (invited review)

  6. Power control device

    International Nuclear Information System (INIS)

    Fukawa, Naohiro.

    1982-01-01

    Purpose: To alleviate the load of an operator by automatically operating the main controller, the speed controller, etc. of a recirculation control system and safely operating them without erroneous operation for long period of time, thereby improving the efficiency of a plant. Constitution: An electric type hydraulic control device controls loads of a turbine and a generator and outputs a control signal also to the main controller of a recirculation flow rate control system. At this time, the main controller is set at an automatic position, and the speed controller receives a recirculation pump speed signal from the main controller at the automatic position. The speed controller outputs a pump speed control signal to the recirculation pump system, and a reactor generates a power corresponding thereto. When the power control is automatically performed by the recirculation flow rate control, an operator sets a rate of change of the recirculation pump speed and the rate of change of the mean power range monitor at a change rate setting unit. Therefore, the control of the recirculation flow rate under the power control can be substantially entirely automated. (Yoshigara, H.)

  7. Mechanisms of Cell Polarity-Controlled Epithelial Homeostasis and Immunity in the Intestine.

    Science.gov (United States)

    Klunder, Leon J; Faber, Klaas Nico; Dijkstra, Gerard; van IJzendoorn, Sven C D

    2017-07-05

    Intestinal epithelial cell polarity is instrumental to maintain epithelial homeostasis and balance communications between the gut lumen and bodily tissue, thereby controlling the defense against gastrointestinal pathogens and maintenance of immune tolerance to commensal bacteria. In this review, we highlight recent advances with regard to the molecular mechanisms of cell polarity-controlled epithelial homeostasis and immunity in the human intestine. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

  8. Direct generation of linearly polarized single photons with a deterministic axis in quantum dots

    Directory of Open Access Journals (Sweden)

    Wang Tong

    2017-07-01

    Full Text Available We report the direct generation of linearly polarized single photons with a deterministic polarization axis in self-assembled quantum dots (QDs, achieved by the use of non-polar InGaN without complex device geometry engineering. Here, we present a comprehensive investigation of the polarization properties of these QDs and their origin with statistically significant experimental data and rigorous k·p modeling. The experimental study of 180 individual QDs allows us to compute an average polarization degree of 0.90, with a standard deviation of only 0.08. When coupled with theoretical insights, we show that these QDs are highly insensitive to size differences, shape anisotropies, and material content variations. Furthermore, 91% of the studied QDs exhibit a polarization axis along the crystal [1–100] axis, with the other 9% polarized orthogonal to this direction. These features give non-polar InGaN QDs unique advantages in polarization control over other materials, such as conventional polar nitride, InAs, or CdSe QDs. Hence, the ability to generate single photons with polarization control makes non-polar InGaN QDs highly attractive for quantum cryptography protocols.

  9. Direct generation of linearly polarized single photons with a deterministic axis in quantum dots

    Science.gov (United States)

    Wang, Tong; Puchtler, Tim J.; Patra, Saroj K.; Zhu, Tongtong; Ali, Muhammad; Badcock, Tom J.; Ding, Tao; Oliver, Rachel A.; Schulz, Stefan; Taylor, Robert A.

    2017-07-01

    We report the direct generation of linearly polarized single photons with a deterministic polarization axis in self-assembled quantum dots (QDs), achieved by the use of non-polar InGaN without complex device geometry engineering. Here, we present a comprehensive investigation of the polarization properties of these QDs and their origin with statistically significant experimental data and rigorous k·p modeling. The experimental study of 180 individual QDs allows us to compute an average polarization degree of 0.90, with a standard deviation of only 0.08. When coupled with theoretical insights, we show that these QDs are highly insensitive to size differences, shape anisotropies, and material content variations. Furthermore, 91% of the studied QDs exhibit a polarization axis along the crystal [1-100] axis, with the other 9% polarized orthogonal to this direction. These features give non-polar InGaN QDs unique advantages in polarization control over other materials, such as conventional polar nitride, InAs, or CdSe QDs. Hence, the ability to generate single photons with polarization control makes non-polar InGaN QDs highly attractive for quantum cryptography protocols.

  10. Automatic exchange unit for control rod drive device

    International Nuclear Information System (INIS)

    Nasu, Seiji; Sasaki, Masayoshi.

    1982-01-01

    Purpose: To enable automatic reoperation and continuation without external power interruption remedy device at the time of recovering the interrupted power soruce during automatic positioning operation. Constitution: In case of an automatic exchange unit for a control rod drive device of the control type for setting the deviation between the positioning target position and the present position of the device to zero, the position data of the drive device of the positioning target value of the device is automatically read, and an interlock of operation inhibit is applied to a control system until the data reading is completed and automatic operation start or restart conditions are sequentially confirmed. After the confirmation, the interlock is released to start the automatic operation or reoperation. Accordingly, the automatic operation can be safely restarted and continued. (Yoshihara, H.)

  11. Automatic operation device for control rods

    International Nuclear Information System (INIS)

    Sekimizu, Koichi

    1984-01-01

    Purpose: To enable automatic operation of control rods based on the reactor operation planning, and particularly, to decrease the operator's load upon start up and shutdown of the reactor. Constitution: Operation plannings, demand for the automatic operation, break point setting value, power and reactor core flow rate change, demand for operation interrupt, demand for restart, demand for forecasting and the like are inputted to an input device, and an overall judging device performs a long-term forecast as far as the break point by a long-term forecasting device based on the operation plannings. The automatic reactor operation or the like is carried out based on the long-term forecasting and the short time forecasting is performed by the change in the reactor core status due to the control rod operation sequence based on the control rod pattern and the operation planning. Then, it is judged if the operation for the intended control rod is possible or not based on the result of the short time forecasting. (Aizawa, K.)

  12. Control rod guide tube cleaning device

    International Nuclear Information System (INIS)

    Tsuji, Tadashi; Shiota, Yoshiaki.

    1990-01-01

    Since there was no exclusive device for cleaning control rods, no effective cleaning could not be conducted and there was a possibility that obstacles may not be recovered. Then, there are disposed a first pump for supplying pressurized water, a spray nozzle for forming a swirling flow in a control rod guide tube, a second pump for pressurizing water introduced by a sucking pipeline and a collecting device for recovering obstacles intruding to water from the second pump. The pressurized water supplied from the first pump is introduced to a head passing through a blowing pipe and jetted from the spray nozzle to the control rod guide tube. In this case, a swirling stream occurs and obstacles in the control guide tube are mixed into water. The water containing the obstacles passes from the sucking port through a pipeline, introduced to the second pump and recovered to the collecting device. Since there is no water staying portion upon cleaning operation, the obstacles accumulating over the entire region of the bottom of the guide tube can be recovered reliably and efficiently. (N.H.)

  13. Feedwater control method and device therefor

    International Nuclear Information System (INIS)

    Nakahara, Mitsugu; Ichikawa, Yoshiaki; Ishii, Yoshikazu; Suzuki, Katsuyuki; Tanikawa, Naoshi; Mizuki, Fumio.

    1997-01-01

    The present invention provides a method of and a device for easily changing the constitution of feedwater systems without causing change in the water level of a reactor even when a plurality of feedwater systems have imbalance points. Namely, a feedwater control device comprises at least two feedwater systems capable of feeding water to tanks independently respectively and a controller capable of controlling water level in the tanks by controlling these feedwater systems. There is disposed a means for outputting gradually increasing driving signals to other feedwater systems, when the water level controller automatically controls one of the feedwater systems. There is also disposed a means for switching from automatic control for one of the feedwater systems to automatic control for the other feedwater system by a water level controller when the other feedwater system is in a stable operation region. As a result, entire feedwater flow rate is not temporarily changed and the water level in the tanks can be maintained constant. (N.H.)

  14. Topology optimization of piezo modal transducers with null-polarity phases

    DEFF Research Database (Denmark)

    Donoso, A.; Sigmund, O.

    2016-01-01

    Piezo modal transducers in 2d can be designed theoretically by tailoring polarity of the surface electrodes. However, it is also necessary to include null-polarity phases of known width separating areas of opposite polarity in the manufacturing process in order to avoid short-circuiting. Otherwise...... the performance of such devices could be spoiled. In this work, we propose an appropriate topology optimization interpolation function for the electrode profile such that the effect of this new phase (hereafter gap-phase) is included in the formulation of the design problem. The approach is density-based, where...... the interface is controlled by including the gradient norm in the electrode profile interpolation. Through a detailed case study in 1d, conclusions on how to control the width of this gap-phase are extracted, and subsequently extended to the 2d case....

  15. A bromine-based dichroic X-ray polarization analyser

    CERN Document Server

    Collins, S P; Brown, S D; Thompson, P

    2001-01-01

    We have demonstrated the advantages offered by dichroic X-ray polarization filters for linear polarization analysis, and describe such a device, based on a dibromoalkane/urea inclusion compound. The polarizer has been successfully tested by analysing the polarization of magnetic diffraction from holmium.

  16. Plasma control device

    International Nuclear Information System (INIS)

    Takase, Haruhiko.

    1987-01-01

    Purpose: To obtain the optimum controllability for the plasmas and the thermonuclear device by selectively executing control operation for proportion, integration and differentiation (PID) by first and second controllers respectively based on selection instruction signals. Constitution: Deviation between a vertical direction equilibrium position: Zp as the plasma status amount measured in a measuring section and an aimed value Zref thereof is inputted to a first PID selection controller. The first controller selectively executes one of the PID control operations in accordance with the first selection signal instruction instructed by a PID control operation instruction circuit. Further, Zp is also inputted to a second PID selection controller, which selectively executes one of the PID control operations in accordance with the second selection instruction signal in the same manner as in the first controller. The deviation amount u between operations signals u1 and u2 from the first and second PID selection controllers is inputted to a power source to thereby supply a predetermined current value to control coils that generate equilibrium magnetic fields for making the vertical direction equilibrium position of plasmas constant. (Kamimura, M.)

  17. A safety control device for detecting undesirable conditions

    Energy Technology Data Exchange (ETDEWEB)

    1974-09-26

    The invention relates to safety control devices. It deals with a device adapted to transmit a warning signal and to the detection of an undesirable condition in an associated apparatus, said device comprising switching means comprising transistors mounted in a reaction path, feeding means for opening the switching means whenever an undesirable condition has been detected by sensors, whereby an oscillator is caused to stop oscillating, and an outlet device controlled by the oscillator stoppage. This can be applied to the supervision of nuclear reactor.

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

    Science.gov (United States)

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

    2018-07-01

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

  19. Metal-Controlled Magnetoresistance at Room Temperature in Single-Molecule Devices.

    Science.gov (United States)

    Aragonès, Albert C; Aravena, Daniel; Valverde-Muñoz, Francisco J; Real, José Antonio; Sanz, Fausto; Díez-Pérez, Ismael; Ruiz, Eliseo

    2017-04-26

    The appropriate choice of the transition metal complex and metal surface electronic structure opens the possibility to control the spin of the charge carriers through the resulting hybrid molecule/metal spinterface in a single-molecule electrical contact at room temperature. The single-molecule conductance of a Au/molecule/Ni junction can be switched by flipping the magnetization direction of the ferromagnetic electrode. The requirements of the molecule include not just the presence of unpaired electrons: the electronic configuration of the metal center has to provide occupied or empty orbitals that strongly interact with the junction metal electrodes and that are close in energy to their Fermi levels for one of the electronic spins only. The key ingredient for the metal surface is to provide an efficient spin texture induced by the spin-orbit coupling in the topological surface states that results in an efficient spin-dependent interaction with the orbitals of the molecule. The strong magnetoresistance effect found in this kind of single-molecule wire opens a new approach for the design of room-temperature nanoscale devices based on spin-polarized currents controlled at molecular level.

  20. Wind turbine remote control using Android devices

    Science.gov (United States)

    Rat, C. L.; Panoiu, M.

    2018-01-01

    This paper describes the remote control of a wind turbine system over the internet using an Android device, namely a tablet or a smartphone. The wind turbine workstation contains a LabVIEW program which monitors the entire wind turbine energy conversion system (WECS). The Android device connects to the LabVIEW application, working as a remote interface to the wind turbine. The communication between the devices needs to be secured because it takes place over the internet. Hence, the data are encrypted before being sent through the network. The scope was the design of remote control software capable of visualizing real-time wind turbine data through a secure connection. Since the WECS is fully automated and no full-time human operator exists, unattended access to the turbine workstation is needed. Therefore the device must not require any confirmation or permission from the computer operator in order to control it. Another condition is that Android application does not have any root requirements.

  1. Device Configuration Handler for Accelerator Control Applications at Jefferson Lab

    International Nuclear Information System (INIS)

    Bickley, Matt; Chevtsov, P.; Larrieu, T.

    2003-01-01

    The accelerator control system at Jefferson Lab uses hundreds of physical devices with such popular instrument bus interfaces as Industry Pack (IPAC), GPIB, RS-232, etc. To properly handle all these components, control computers (IOCs) must be provided with the correct information about the unique memory addresses of the used interface cards, interrupt numbers (if any), data communication channels and protocols. In these conditions, the registration of a new control device in the control system is not an easy task for software developers. Because the device configuration is distributed, it requires the detailed knowledge about not only the new device but also the configuration of all other devices on the existing system. A configuration handler implemented at Jefferson Lab centralizes the information about all control devices making their registration user-friendly and very easy to use. It consists of a device driver framework and the device registration software developed on the basis of ORACLE database and freely available scripting tools (perl, php)

  2. GPS User Devices Parameter Control Methods

    OpenAIRE

    Klūga, A; Kuļikovs, M; Beļinska, V; Zeļenkovs, A

    2007-01-01

    In our day’s wide assortment of GPS user devices is manufacture. How to verify that parameters of the real device corresponds to parameters that manufacture shows. How to verify that parameters have not been changed during the operation time. The last one is very important for aviation GPS systems, which must be verified before the flight, but the values of parameter in time of repair works. This work analyses GPS user devices parameters control methods.

  3. Selection of input devices and controls for modern process control consoles

    International Nuclear Information System (INIS)

    Hasenfuss, O.; Zimmermann, R.

    1975-06-01

    In modern process control consoles man-machine communication is realized more and more by computer driven CRT displays, the most efficient communication system today. This paper describes the most important input devices and controls for such control consoles. A certain number of facts are given, which should be considered during the selection. The aptitude of the described devices for special tasks is discussed and recommendations are given for carrying out a selection. (orig.) [de

  4. Zero-field precession and hysteretic threshold currents in a spin torque nano device with tilted polarizer

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Yan; Bonetti, S; Zha, C L; Akerman, Johan [Department of Microelectronics and Applied Physics, Royal Institute of Technology, Electrum 229, 164 40 Kista (Sweden)], E-mail: zhouyan@kth.se

    2009-10-15

    Using nonlinear system theory and numerical simulations, we map out the static and dynamic phase diagrams in the zero applied field of a spin torque nano device with a tilted polarizer (TP). We find that for sufficiently large currents, even very small tilt angles ({beta}>1 deg.) will lead to steady free layer precession in zero field. Within a rather large range of tilt angles, 1 deg. <{beta}<19 deg., we find coexisting static states and hysteretic switching between these using only current. In a more narrow window (1 deg. <{beta}<5 deg.) one of the static states turns into a limit cycle (precession). The coexistence of current-driven static and dynamic states in the zero magnetic field is unique to the TP device and leads to large hysteresis in the upper and lower threshold currents for its operation. The nano device with TP can facilitate the generation of large amplitude mode of spin torque signals without the need for cumbersome magnetic field sources and thus should be very important for future telecommunication applications based on spin transfer torque effects.

  5. Ultracompact and broadband polarization beam splitter based on polarization-dependent critical guiding condition.

    Science.gov (United States)

    Ying, Zhoufeng; Wang, Guanghui; Zhang, Xuping; Ho, Ho-pui; Huang, Ying

    2015-05-01

    An ultracompact and broadband polarization beam splitter (PBS) based on the polarization-dependent critical guiding condition of an asymmetrical directional coupler is proposed. The device consists of a pair of silicon waveguides with different height and width. Due to the different cutoff conditions for the TE and TM polarization modes, it is possible to have the TM mode guided in one waveguide while the TE mode is supported in both. Therefore, only the phase-matching condition for the cross-coupling of the TE mode needs to be considered. This approach not only simplifies the design procedures but also significantly improves device performance with smaller total length and larger bandwidth. Finally, regardless of the contribution of S-bend waveguides, our proposed PBS has a coupling region as short as 0.2 μm, which is the shortest reported until now. The simulation result shows that the extinction ratios for the TE and TM polarization are 13.5 and 16.6 dB at their respective output ports, and their insertion losses are 0.29 and 0.13 dB, respectively. Numerical simulations also show that the device offers a very large bandwidth (∼140  nm) with large extinction ratio (>10  dB) and low insertion loss (<1  dB).

  6. Polarization holograms in a bifunctional amorphous polymer exhibiting equal values of photoinduced linear and circular birefringences.

    Science.gov (United States)

    Provenzano, Clementina; Pagliusi, Pasquale; Cipparrone, Gabriella; Royes, Jorge; Piñol, Milagros; Oriol, Luis

    2014-10-09

    Light-controlled molecular alignment is a flexible and useful strategy introducing novelty in the fields of mechanics, self-organized structuring, mass transport, optics, and photonics and addressing the development of smart optical devices. Azobenzene-containing polymers are well-known photocontrollable materials with large and reversible photoinduced optical anisotropies. The vectorial holography applied to these materials enables peculiar optical devices whose properties strongly depend on the relative values of the photoinduced birefringences. Here is reported a polarization holographic recording based on the interference of two waves with orthogonal linear polarization on a bifunctional amorphous polymer that, exceptionally, exhibits equal values of linear and circular birefringence. The peculiar photoresponse of the material coupled with the holographic technique demonstrates an optical device capable of decomposing the light into a set of orthogonally polarized linear components. The holographic structures are theoretically described by the Jones matrices method and experimentally investigated.

  7. Non-volatile polarization switch of magnetic domain wall velocity

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Z.; Stolichnov, I.; Setter, N. [Ceramics Laboratory, EPFL-Swiss Federal Institute of Technology, Lausanne 1015 (Switzerland); Bernand-Mantel, A.; Schott, Marine; Pizzini, S.; Ranno, L. [University of Grenoble Alpes, Institut Néel, F-38042 Grenoble (France); CNRS, Institut Néel, F-38042 Grenoble (France); Auffret, S.; Gaudin, G. [SPINTEC, UMR-8191, CEA/CNRS/UJF/GINP, INAC, F-38054 Grenoble (France)

    2015-12-21

    Controlled propagation speed of individual magnetic domains in metal channels at the room temperature is obtained via the non-volatile field effect associated with the switchable polarization of P(VDF-TrFE) (polyvinylidene fluoride-trifluoroethylene) ferroelectric polymer. Polarization domains directly written using conducting atomic force microscope probe locally accelerate/decelerate the magnetic domains in the 0.6 nm thick Co film. The change of the magnetic domain wall velocity is consistent with the magnetic anisotropy energy modulation through the polarization upward/downward orientation. Excellent retention is observed. The demonstrated local non-destructive and reversible change of magnetic properties via rewritable patterning of ferroelectric domains could be attractive for exploring the ultimate limit of miniaturization in devices based on ferromagnetic/ferroelectric bilayers.

  8. Device for controlling gas recovery

    International Nuclear Information System (INIS)

    Ichioka, Atsushi.

    1976-01-01

    Purpose: To provide a controlling device for UF 6 gas recovery device, which can increase working efficiency and to discriminate normality and abnormality of the recovery device. Constitution: The gas recovery device comprises a plurality of traps, which are connected in series. The UF 6 gas is introduced into the first trap where adsorbing work is taken place to accumulate UF 6 gases, and the UF 6 gases partly flow into the succeeding trap. Even in this trap, when the adsorbing work begins, the succeeding trap is operated in series fashion. In this manner, two traps are continuously operated to recover the gases while performing the steps of adsorbing, waiting and regenerating in that order. The switching operation of the aforesaid steps is accomplished on the basis of concentration of the UF 6 detected between two traps, which are continuously driven. (Kamimura, M.)

  9. Use of UPFC device controlled by fuzzy logic controllers for decoupled power flow control

    Directory of Open Access Journals (Sweden)

    Ivković Sanja

    2014-01-01

    Full Text Available This paper investigates the possibility of decoupled active and reactive power flow control in a power system using a UPFC device controlled by fuzzy logic controllers. A Brief theoretical review of the operation principles and applications of UPFC devices and design principles of the fuzzy logic controller used are given. A Matlab/Simulink model of the system with UPFC, the fuzzy controller setup, and graphs of the results are presented. Conclusions are drawn regarding the possibility of using this system for decoupled control of the power flow in power systems based on analysis of these graphs.

  10. Rode's iterative calculation of surface optical phonon scattering limited electron mobility in N-polar GaN devices

    International Nuclear Information System (INIS)

    Ghosh, Krishnendu; Singisetti, Uttam

    2015-01-01

    N-polar GaN channel mobility is important for high frequency device applications. Here, we report theoretical calculations on the surface optical (SO) phonon scattering rate of two-dimensional electron gas (2DEG) in N-polar GaN quantum well channels with high-k dielectrics. Rode's iterative calculation is used to predict the scattering rate and mobility. Coupling of the GaN plasmon modes with the SO modes is taken into account and dynamic screening is employed under linear polarization response. The effect of SO phonons on 2DEG mobility was found to be small at >5 nm channel thickness. However, the SO mobility in 3 nm N-polar GaN channels with HfO 2 and ZrO 2 high-k dielectrics is low and limits the total mobility. The SO scattering for SiN dielectric on GaN was found to be negligible due to its high SO phonon energy. Using Al 2 O 3 , the SO phonon scattering does not affect mobility significantly only except the case when the channel is too thin with a low 2DEG density

  11. Polarization control of non-diffractive helical optical beams through subwavelength metallic apertures

    International Nuclear Information System (INIS)

    Lombard, E; Genet, C; Ebbesen, T W; Drezet, A

    2010-01-01

    We demonstrate experimentally a simple method for preparing non-diffractive vectorial optical beams that can display wave-front helicity. This method is based on space-variant modifications of the polarization of an optical beam transmitted through subwavelength annular rings perforating opaque metal films. We show how the description of the optical properties of such structures must account for the vectorial character of the polarization and how, in turn, these properties can be controlled by straightforward sequences of preparation and analysis of polarization states.

  12. Spin-orbit controlled capacitance of a polar heterostructure

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

  13. Method and device for controlling radiation

    International Nuclear Information System (INIS)

    Wilhelm, G.M.

    1979-01-01

    A device which will control radiation emanating from colour television sets is described. It consists of two transparent plates the same size as a television screen, with a thin layer of transparent mineral oil sealed between them. The device may be installed by the manufacturer or bought separately and installed by the user. (LL)

  14. Control system and method for prosthetic devices

    Science.gov (United States)

    Bozeman, Richard J., Jr. (Inventor)

    1992-01-01

    A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the movable body part through the full-shrug position of the movable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the movable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective movable prosthesis device and its sub-prosthesis.

  15. Measured results of polarization crosstalk cancellation using LMS control. [Least Mean Square

    Science.gov (United States)

    Baird, C. A.; Rassweiler, G. G.

    1977-01-01

    This paper discusses the use of wideband decoupling networks for the cancellation of polarization crosstalk in dual-polarized communication links. Measured cancellation performance for an all-electronic IF network and an RF electro-mechanical waveguide network are presented. Each of these networks utilizes LMS-type adaptive control techniques to adjust the cancellation network.

  16. On-chip synthesis of circularly polarized emission of light with integrated photonic circuits.

    Science.gov (United States)

    He, Li; Li, Mo

    2014-05-01

    The helicity of circularly polarized (CP) light plays an important role in the light-matter interaction in magnetic and quantum material systems. Exploiting CP light in integrated photonic circuits could lead to on-chip integration of novel optical helicity-dependent devices for applications ranging from spintronics to quantum optics. In this Letter, we demonstrate a silicon photonic circuit coupled with a 2D grating emitter operating at a telecom wavelength to synthesize vertically emitting, CP light from a quasi-TE waveguide mode. Handedness of the emitted circular polarized light can be thermally controlled with an integrated microheater. The compact device footprint enables a small beam diameter, which is desirable for large-scale integration.

  17. Simultaneously improving optical absorption of both transverse-electric polarized and transverse-magnetic polarized light for organic solar cells with Ag grating used as transparent electrode

    Directory of Open Access Journals (Sweden)

    Yongbing Long

    2014-08-01

    Full Text Available Theoretical simulations are performed to investigate optical performance of organic solar cells with Ag grating electrode. It is demonstrated that optical absorption for both transverse-electric (TE polarized and transverse-magnetic(TM polarized light is simultaneously improved when compared with that for the device without the Ag grating. The improvement is respectively attributed to the resonance and the surface plasmon polaritons within the device. After an additional WO3 layer is capped on the Ag grating, absorption of TE-polarized light is further improved due to resonance of double microcavities within the device, and absorption of TM-polarized light is improved by the combined effects of the microcavity resonance and the surface plasmon polaritons. Correspondingly, the short current density for randomly polarized light is improved by 18.1% from that of the device without the Ag grating. Finally, it is demonstrated that high transmission may not be an essential prerequisite for metallic gratings when they are used as transparent electrode since absorption loss caused by low transmission can be compensated by using a capping layer to optimize optical resonance of the WMC structure within the device.

  18. Wearable Device Control Platform Technology for Network Application Development

    Directory of Open Access Journals (Sweden)

    Heejung Kim

    2016-01-01

    Full Text Available Application development platform is the most important environment in IT industry. There are a variety of platforms. Although the native development enables application to optimize, various languages and software development kits need to be acquired according to the device. The coexistence of smart devices and platforms has rendered the native development approach time and cost consuming. Cross-platform development emerged as a response to these issues. These platforms generate applications for multiple devices based on web languages. Nevertheless, development requires additional implementation based on a native language because of the coverage and functions of supported application programming interfaces (APIs. Wearable devices have recently attracted considerable attention. These devices only support Bluetooth-based interdevice communication, thereby making communication and device control impossible beyond a certain range. We propose Network Application Agent (NetApp-Agent in order to overcome issues. NetApp-Agent based on the Cordova is a wearable device control platform for the development of network applications, controls input/output functions of smartphones and wearable/IoT through the Cordova and Native API, and enables device control and information exchange by external users by offering a self-defined API. We confirmed the efficiency of the proposed platform through experiments and a qualitative assessment of its implementation.

  19. Cryogenic control system of the large COMPASS polarized target

    CERN Document Server

    Gautheron, F; Baum, G; Berglund, P; Doshita, N; Görtz, S; Gustafsson, K K; Horikawa, N; Kisselev, Yu V; Koivuniemi, J H; Kondo, K; Meyer, Werner T; Reicherz, G

    2004-01-01

    The dilution refrigerator used to cool the large COMPASS polarized target is monitored through a PC running LabVIEW trademark 6.1 under Windows 2000 trademark . About 60 parameters of the target (temperatures, pressures, flow rates) are continuously plotted and checked. They are periodically recorded in an Oracle trademark database and in a data file. An alarm for every parameter can be individually activated and optionally connected to a GSM (Global System for Mobile Communication) delivery message system. A web server receives and publishes the online status of the target with online tables and graphics on a dedicated COMPASS polarized target information web site. A Siemens programmable logic controller (PLC) powered by an uninterruptable source keeps the cryogenic system safe and stable during the long beam periods by controlling valves and interlocks. This safety feature protects the dilution refrigerator against potential damages in case of power failure.

  20. Object oriented programming techniques applied to device access and control

    International Nuclear Information System (INIS)

    Goetz, A.; Klotz, W.D.; Meyer, J.

    1992-01-01

    In this paper a model, called the device server model, has been presented for solving the problem of device access and control faced by all control systems. Object Oriented Programming techniques were used to achieve a powerful yet flexible solution. The model provides a solution to the problem which hides device dependancies. It defines a software framework which has to be respected by implementors of device classes - this is very useful for developing groupware. The decision to implement remote access in the root class means that device servers can be easily integrated in a distributed control system. A lot of the advantages and features of the device server model are due to the adoption of OOP techniques. The main conclusion that can be drawn from this paper is that 1. the device access and control problem is adapted to being solved with OOP techniques, 2. OOP techniques offer a distinct advantage over traditional programming techniques for solving the device access problem. (J.P.N.)

  1. Apparatus and methods for memory using in-plane polarization

    Science.gov (United States)

    Liu, Junwei; Chang, Kai; Ji, Shuai-Hua; Chen, Xi; Fu, Liang

    2018-05-01

    A memory device includes a semiconductor layer with an in-plane polarization component switchable between a first direction and a second direction. A writing electrode is employed to apply a writing voltage to the semiconductor layer to change the in-plane polarization component between the first direction and the second direction. A reading electrode is employed to apply a reading voltage to the semiconductor layer to measure a tunneling current substantially perpendicular to the polarization direction of the in-plane polarization component. The directions of the reading voltage and the writing voltage are substantially perpendicular to each other. Therefore, the reading process is non-destructive. Thin films (e.g., one unit cell thick) of ferroelectric material can be used in the memory device to increase the miniaturization of the device.

  2. Antiresonance induced spin-polarized current generation

    Science.gov (United States)

    Yin, Sun; Min, Wen-Jing; Gao, Kun; Xie, Shi-Jie; Liu, De-Sheng

    2011-12-01

    According to the one-dimensional antiresonance effect (Wang X R, Wang Y and Sun Z Z 2003 Phys. Rev. B 65 193402), we propose a possible spin-polarized current generation device. Our proposed model consists of one chain and an impurity coupling to the chain. The energy level of the impurity can be occupied by an electron with a specific spin, and the electron with such a spin is blocked because of the antiresonance effect. Based on this phenomenon our model can generate the spin-polarized current flowing through the chain due to different polarization rates. On the other hand, the device can also be used to measure the generated spin accumulation. Our model is feasible with today's technology.

  3. Applications of polarization speckle in skin cancer detection and monitoring

    Science.gov (United States)

    Lee, Tim K.; Tchvialeva, Lioudmila; Phillips, Jamie; Louie, Daniel C.; Zhao, Jianhua; Wang, Wei; Lui, Harvey; Kalia, Sunil

    2018-01-01

    Polarization speckle is a rapidly developed field. Unlike laser speckle, polarization speckle consists of stochastic interference patterns with spatially random polarizations, amplitudes and phases. We have been working in this exciting research field, developing techniques to generate polarization patterns from skin. We hypothesize that polarization speckle patterns could be used in biomedical applications, especially, for detecting and monitoring skin cancers, the most common neoplasmas for white populations around the world. This paper describes our effort in developing two polarization speckle devices. One of them captures the Stokes parameters So and S1 simultaneously, and another one captures all four Stokes parameters So, S1, S2, and S3 in one-shot, within milliseconds. Hence these two devices could be used in medical clinics and assessed skin conditions in-vivo. In order to validate our hypothesis, we conducted a series of three clinical studies. These are early pilot studies, and the results suggest that the devices have potential to detect and monitor skin cancers.

  4. Detailed analysis of evolution of the state of polarization in all-fiber polarization transformers.

    Science.gov (United States)

    Zhu, Xiushan; Jain, Ravinder K

    2006-10-30

    We present a detailed analysis of key attributes and performance characteristics of controllably-spun birefringent-fiber-based all-fiber waveplates or "all fiber polarization transformers" (AFPTs), first proposed and demonstrated by Huang [11]; these AFPTs consist essentially of a long carefully-designed "spin-twisted" high-birefringence fiber, fabricated by slowly varying the spin rate of a birefringent fiber preform (either from very fast to very slow or vice versa) while the fiber is being drawn. The evolution of the eigenstate from a linear polarization state to a circular polarization state, induced by slow variation of the intrinsic structure from linear anisotropy at the unspun end to circular anisotropy at the fast-spun end, enables the AFPT to behave like an all-fiber quarter-wave plate independent of the wavelength of operation. Power coupling between local eigenstates causes unique evolution of the polarization state along the fiber, and has been studied to gain insight into - as well as to understand detailed characteristics of -- the polarization transformation behavior. This has been graphically illustrated via plots of the relative power in these local eigenstates as a function of distance along the length of the fiber and plots of the extinction ratio of the output state of polarization (SOP) as a function of distance and the normalized spin rate. Deeper understanding of such polarization transformers has been further elucidated by quantitative calculations related to two crucial requirements for fabricating practical AFPT devices. Our calculations have also indicated that the polarization mode dispersion behaviour of the AFPT is much smaller than that of the original birefringent fiber. Finally, a specific AFPT was experimentally investigated at two widely-separated wavelengths (1310 nm and 1550 nm) of interest in telecommunications systems applications, further demonstrating and elucidating the broadband character of such AFPTs.

  5. Detection device for control rod scram

    International Nuclear Information System (INIS)

    Ishiyama, Satoshi.

    1989-01-01

    The device of the present invention comprises a control rod dropping separately from a control rod driving mechanism main body, a following tube falling separately accompanying therewith and a guide tube for guiding the dropping of the control rod and the following tube. Further, rare earth permanent magnets are embedded with the pole being axially oriented in the following tube and bobbins each mounted with an inner flange made of high magnetic permeability material are disposed to the guide tube. Coils are wound in the bobbin. In this control rod scram detection device, since magnetic fluxes can effectively be supplied to the coils, it is possible to obtain stable and highly reliable scram detection signals. Further, since the coils and the bobbins can be manufactured separately from the guide tube, their assemblies can be tested independently from the guide tube. (K.M.)

  6. Photoemission of Bi_{2}Se_{3} with Circularly Polarized Light: Probe of Spin Polarization or Means for Spin Manipulation?

    Directory of Open Access Journals (Sweden)

    J. Sánchez-Barriga

    2014-03-01

    Full Text Available Topological insulators are characterized by Dirac-cone surface states with electron spins locked perpendicular to their linear momenta. Recent theoretical and experimental work implied that this specific spin texture should enable control of photoelectron spins by circularly polarized light. However, these reports questioned the so far accepted interpretation of spin-resolved photoelectron spectroscopy. We solve this puzzle and show that vacuum ultraviolet photons (50–70 eV with linear or circular polarization indeed probe the initial-state spin texture of Bi_{2}Se_{3} while circularly polarized 6-eV low-energy photons flip the electron spins out of plane and reverse their spin polarization, with its sign determined by the light helicity. Our photoemission calculations, taking into account the interplay between the varying probing depth, dipole-selection rules, and spin-dependent scattering effects involving initial and final states, explain these findings and reveal proper conditions for light-induced spin manipulation. Our results pave the way for future applications of topological insulators in optospintronic devices.

  7. Direct-current polarization characteristics of various AlGaAs laser diodes

    Science.gov (United States)

    Fuhr, P. L.

    1984-01-01

    Polarization characteristics of AlGaAs laser diodes having various device geometries have been measured. Measurements were performed with the laser diodes operating under dc conditions. Results show that laser diodes having different device geometries have optical outputs that exhibit varying degrees of polarization purity. Implications of this result, with respect to incoherent polarization-beam combining, are addressed.

  8. A proposed protocol for remote control of automated assessment devices

    International Nuclear Information System (INIS)

    Kissock, P.S.; Pritchard, D.A.

    1996-01-01

    Systems and devices that are controlled remotely are becoming more common in security systems in the US Air Force and other government agencies to provide protection of valuable assets. These systems reduce the number of needed personnel while still providing a high level of protection. However, each remotely controlled device usually has its own communication protocol. This limits the ability to change devices without changing the system that provides the communications control to the device. Sandia is pursuing a standard protocol that can be used to communicate with the different devices currently in use, or may be used in the future, in the US Air Force and other government agencies throughout the security community. Devices to be controlled include intelligent pan/tilt mounts, day/night video cameras, thermal imaging cameras, and remote data processors. Important features of this protocol include the ability to send messages of varying length, identify the sender, and more importantly, control remote data processors. This paper describes the proposed public domain protocol, features, and examples of use. The authors hope to elicit comments from security technology developers regarding format and use of remotely controlled automated assessment devices

  9. Evaluation of a completely automated cold fiber device using compounds with varying volatility and polarity.

    Science.gov (United States)

    Jiang, Ruifen; Carasek, Eduardo; Risticevic, Sanja; Cudjoe, Erasmus; Warren, Jamie; Pawliszyn, Janusz

    2012-09-12

    A fully automated cold fiber solid phase microextraction device has been developed by coupling to a GERSTEL multipurpose (MPS 2) autosampler and applied to the analysis of volatiles and semi-volatiles in aqueous and solid matrices. The proposed device was thoroughly evaluated for its extraction performance, robustness, reproducibility and reliability by gas chromatograph/mass spectrometer (GC/MS). With the use of a septumless head injector, the entire automated setup was capable of analyzing over 200 samples without any GC injector leakages. Evaluation of the automated cold fiber device was carried out using a group of compounds characterized by different volatilities and polarities. Extraction efficiency as well as analytical figures of merit was compared to commercial solid phase microextraction fibers. The automated cold fiber device showed significantly improved extraction efficiency compared to the commercial polydimethylsiloxane (PDMS) and cold fiber without cooling for the analysis of aqueous standard samples due to the low temperature of the coating. Comparing results obtained from cold fiber and commercial divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber temperature profile demonstrated that the temperature gap between the sample matrix and the coating improved the distribution coefficient and therefore the extraction amount. The linear dynamic range of the cold fiber device was 0.5 ng mL(-1) to 100 ng mL(-1) with a linear regression coefficient ≥0.9963 for all compounds. The limit of detection for all analytes ranged from 1.0 ng mL(-1) to 9.4 ng mL(-1). The newly automated cold fiber device presents a platform for headspace analysis of volatiles and semi-volatiles for large number of samples with improved throughput and sensitivity. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Method for installing a control rod driving device in a reactor

    International Nuclear Information System (INIS)

    Sato, Haruo; Watanabe, Masatoshi.

    1975-01-01

    Object: To install a device using a wire rope, including individually moving up and down a control rod and a control rod driving device thereby enabling to install them within a low house and to reduce time required for installing operation. Structure: The control rod is temporarily attached to a support structure for the control rod driving device, the control rod driving device is suspended on a crane positioned upwardly of the support structure, a rope connected to the control rod driving device is connected to the control rod, a sagged portion of the rope is then wound about a rotary cylinder, the control rod is disconnected from its temporary attachment, and the wound rope is wound back while the rotary cylinder is rotated to move down the control rod. After the rope has been released from the rotary cylinder, the control rod driving device is moved down by the crane. (Kamimura, M.)

  11. Control of radial propagation and polarity in a plasma jet in surrounding Ar

    KAUST Repository

    Gong, W.

    2018-01-08

    In recent years, the use of shielding gas to prevent the diffusion of the ambient air, particularly oxygen and nitrogen species, into the effluent of the atmospheric pressure plasma jet, and thus control the nature of chemical species used in the plasma treatment has increased. In this paper, the radial propagation of a plasma jet in ambient Ar is examined to find the key determinants of the polarity of plasma jets. The dynamics of the discharge reveal that the radial diffusion discharge is a special phenomenon observed only at the falling edge of the pulses. The radial transport of electrons, which is driven by the radial component of the applied electric field at the falling edge of the pulse, is shown to play an important role in increasing the seed electron density in the surrounding Ar. This result suggests a method to provide seed electrons at atmospheric pressure with a negative discharge. The polarity of the plasma jet is found to be determined by the pulse width rather than the polarity of the applied voltage, as it dictates the relative difference in the intensity of the two discharges in a single pulse, where the stronger discharge in a pulse dominates the behavior of the plasma jet. Accordingly, a method to control the polarity of a plasma jet through varying the pulse width is developed. Since plasma jets of different polarities differ remarkably in terms of their characteristics, the method to control the polarity reported in this paper will be of use for such applications as plasma-enhanced processing of materials and plasma biomedicine.

  12. Control of radial propagation and polarity in a plasma jet in surrounding Ar

    Science.gov (United States)

    Gong, W.; Yue, Y.; Ma, F.; Yu, F.; Wan, J.; Nie, L.; Bazaka, K.; Xian, Y.; Lu, X.; Ostrikov, K.

    2018-01-01

    In recent years, the use of shielding gas to prevent the diffusion of the ambient air, particularly oxygen and nitrogen species, into the effluent of the atmospheric pressure plasma jet, and thus control the nature of chemical species used in the plasma treatment has increased. In this paper, the radial propagation of a plasma jet in ambient Ar is examined to find the key determinants of the polarity of plasma jets. The dynamics of the discharge reveal that the radial diffusion discharge is a special phenomenon observed only at the falling edge of the pulses. The radial transport of electrons, which is driven by the radial component of the applied electric field at the falling edge of the pulse, is shown to play an important role in increasing the seed electron density in the surrounding Ar. This result suggests a method to provide seed electrons at atmospheric pressure with a negative discharge. The polarity of the plasma jet is found to be determined by the pulse width rather than the polarity of the applied voltage, as it dictates the relative difference in the intensity of the two discharges in a single pulse, where the stronger discharge in a pulse dominates the behavior of the plasma jet. Accordingly, a method to control the polarity of a plasma jet through varying the pulse width is developed. Since plasma jets of different polarities differ remarkably in terms of their characteristics, the method to control the polarity reported in this paper will be of use for such applications as plasma-enhanced processing of materials and plasma biomedicine.

  13. Optimization of incident EC wave polarization in real-time polarization scan experiments on LHD

    International Nuclear Information System (INIS)

    Tsujimura, Toru I.; Mizuno, Yoshinori; Makino, Ryohei

    2016-01-01

    Real-time polarization scan experiments were performed on the Large Helical Device (LHD) to search an optimal incident wave polarization for electron cyclotron resonance heating. The obtained optimal polarization state to maximize the power absorption to the LHD plasma is compared with the ray-tracing code that includes mode content analyses, which indicates that the calculated results are generally in good agreement with the experimental results. The analyses show that optimal coupling to plasma waves requires a fine adjustment for an incident wave polarization even for perpendicular injection due to the finite density profile and the magnetic shear at the peripheral region. (author)

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

    Science.gov (United States)

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

    2018-03-01

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

  15. Extraordinary Effects in Quasi-Periodic Gold Nanocavities: Enhanced Transmission and Polarization Control of Cavity Modes.

    Science.gov (United States)

    Dhama, Rakesh; Caligiuri, Vincenzo; Petti, Lucia; Rashed, Alireza R; Rippa, Massimo; Lento, Raffaella; Termine, Roberto; Caglayan, Humeyra; De Luca, Antonio

    2018-01-23

    Plasmonic quasi-periodic structures are well-known to exhibit several surprising phenomena with respect to their periodic counterparts, due to their long-range order and higher rotational symmetry. Thanks to their specific geometrical arrangement, plasmonic quasi-crystals offer unique possibilities in tailoring the coupling and propagation of surface plasmons through their lattice, a scenario in which a plethora of fascinating phenomena can take place. In this paper we investigate the extraordinary transmission phenomenon occurring in specifically patterned Thue-Morse nanocavities, demonstrating noticeable enhanced transmission, directly revealed by near-field optical experiments, performed by means of a scanning near-field optical microscope (SNOM). SNOM further provides an intuitive picture of confined plasmon modes inside the nanocavities and confirms that localization of plasmon modes is based on size and depth of nanocavities, while cross talk between close cavities via propagating plasmons holds the polarization response of patterned quasi-crystals. Our performed numerical simulations are in good agreement with the experimental results. Thus, the control on cavity size and incident polarization can be used to alter the intensity and spatial properties of confined cavity modes in such structures, which can be exploited in order to design a plasmonic device with customized optical properties and desired functionalities, to be used for several applications in quantum plasmonics.

  16. Few-mode vertical-cavity surface-emitting laser: Optional emission of transverse modes with different polarizations

    Science.gov (United States)

    Zhong, Chuyu; Zhang, Xing; Hofmann, Werner; Yu, Lijuan; Liu, Jianguo; Ning, Yongqiang; Wang, Lijun

    2018-05-01

    Few-mode vertical-cavity surface-emitting lasers that can be controlled to emit certain modes and polarization states simply by changing the biased contacts are proposed and fabricated. By directly etching trenches in the p-doped distributed Bragg reflector, the upper mesa is separated into several submesas above the oxide layer. Individual contacts are then deposited. Each contact is used to control certain transverse modes with different polarization directions emitted from the corresponding submesa. These new devices can be seen as a prototype of compact laser sources in mode division multiplexing communications systems.

  17. High-efficiency broadband polarization converter based on Ω-shaped metasurface

    Science.gov (United States)

    Zhang, Tianyao; Huang, Lingling; Li, Xiaowei; Liu, Juan; Wang, Yongtian

    2017-11-01

    The polarization state, which cannot be directly detected by human eyes, forms an important characteristic of electromagnetic waves. Control of polarization states has long been pursued for various applications. Conventional polarization converters can hardly meet the requirements in lab-on-chip systems, due to the involvement of bulk materials. Here, we propose the design and realization of a linear to circular polarization converter based on metasurfaces. The metasurface is deliberately designed using achiral two-fold mirror symmetry Ω-shaped antennas. The converter integrates a ground metal plane, a spacer dielectric layer and an antenna array, leading to a high conversion efficiency and broad operating bandwidth in the near infrared regime. The calculated Stokes parameters indicate an excellent conversion of linear to circular polarization for the reflected light. The tunability of the bandwidth by oblique incidence and by modulating the thickness of the dielectric layer is also introduced and demonstrated, which shows great flexibilities for such metasurface converters. The proposed metasurface may open up intriguing possibilities towards the realization of ultrathin nanophotonic devices for polarization manipulation and wavefront engineering.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Sen; Zhang, Yan, E-mail: yzhang@mail.cnu.edu.cn [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)

    2015-12-14

    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.

  19. Automated polarization control for the precise alignment of laser-induced self-organized nanostructures

    Science.gov (United States)

    Hermens, Ulrike; Pothen, Mario; Winands, Kai; Arntz, Kristian; Klocke, Fritz

    2018-02-01

    Laser-induced periodic surface structures (LIPSS) found in particular applications in the fields of surface functionalization have been investigated since many years. The direction of these ripple structures with a periodicity in the nanoscale can be manipulated by changing the laser polarization. For industrial use, it is useful to manipulate the direction of these structures automatically and to obtain smooth changes of their orientation without any visible inhomogeneity. However, currently no system solution exists that is able to control the polarization direction completely automated in one software solution so far. In this paper, a system solution is presented that includes a liquid crystal polarizer to control the polarization direction. It is synchronized with a scanner, a dynamic beam expander and a five axis-system. It provides fast switching times and small step sizes. First results of fabricated structures are also presented. In a systematic study, the conjunction of LIPSS with different orientation in two parallel line scans has been investigated.

  20. The Physics of Polarization

    Science.gov (United States)

    Landi Degl'Innocenti, Egidio

    2015-10-01

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

  1. Plasmon-induced carrier polarization in semiconductor nanocrystals

    Science.gov (United States)

    Yin, Penghui; Tan, Yi; Fang, Hanbing; Hegde, Manu; Radovanovic, Pavle V.

    2018-06-01

    Spintronics1 and valleytronics2 are emerging quantum electronic technologies that rely on using electron spin and multiple extrema of the band structure (valleys), respectively, as additional degrees of freedom. There are also collective properties of electrons in semiconductor nanostructures that potentially could be exploited in multifunctional quantum devices. Specifically, plasmonic semiconductor nanocrystals3-10 offer an opportunity for interface-free coupling between a plasmon and an exciton. However, plasmon-exciton coupling in single-phase semiconductor nanocrystals remains challenging because confined plasmon oscillations are generally not resonant with excitonic transitions. Here, we demonstrate a robust electron polarization in degenerately doped In2O3 nanocrystals, enabled by non-resonant coupling of cyclotron magnetoplasmonic modes11 with the exciton at the Fermi level. Using magnetic circular dichroism spectroscopy, we show that intrinsic plasmon-exciton coupling allows for the indirect excitation of the magnetoplasmonic modes, and subsequent Zeeman splitting of the excitonic states. Splitting of the band states and selective carrier polarization can be manipulated further by spin-orbit coupling. Our results effectively open up the field of plasmontronics, which involves the phenomena that arise from intrinsic plasmon-exciton and plasmon-spin interactions. Furthermore, the dynamic control of carrier polarization is readily achieved at room temperature, which allows us to harness the magnetoplasmonic mode as a new degree of freedom in practical photonic, optoelectronic and quantum-information processing devices.

  2. Study on polarized optical flow algorithm for imaging bionic polarization navigation micro sensor

    Science.gov (United States)

    Guan, Le; Liu, Sheng; Li, Shi-qi; Lin, Wei; Zhai, Li-yuan; Chu, Jin-kui

    2018-05-01

    At present, both the point source and the imaging polarization navigation devices only can output the angle information, which means that the velocity information of the carrier cannot be extracted from the polarization field pattern directly. Optical flow is an image-based method for calculating the velocity of pixel point movement in an image. However, for ordinary optical flow, the difference in pixel value as well as the calculation accuracy can be reduced in weak light. Polarization imaging technology has the ability to improve both the detection accuracy and the recognition probability of the target because it can acquire the extra polarization multi-dimensional information of target radiation or reflection. In this paper, combining the polarization imaging technique with the traditional optical flow algorithm, a polarization optical flow algorithm is proposed, and it is verified that the polarized optical flow algorithm has good adaptation in weak light and can improve the application range of polarization navigation sensors. This research lays the foundation for day and night all-weather polarization navigation applications in future.

  3. A multichannel and wide suitablity digital control device for liquid-crystal microlens controlled electrically

    Science.gov (United States)

    Zhang, Bo; Xin, Zhaowei; Wei, Dong; Zhang, Xinyu; Wang, Haiwei; Xie, Changsheng

    2017-11-01

    In order to overcome the difficulty in imaging detection of high-speed moving targets under complex environments, and to get more comprehensive image information of the target, there is a urgent need to develop new high-performance optical imaging components. Compared to traditional lenses which have fixed shapes and immutable focal length, liquid-crystal microlens (LCMs) can not only adjust the focal length without changing the external shape, but also realize many practical functions such as swinging focus, spectral selection, depth of field adjustment, etc. The physical properties of spatial electric fields constructed between electrode plates of the LCMs are directly related to the light-field adjusting performances of LCMs, such as the polarity of electric field, the frequency and amplitude of applied voltage signal. In other words, the optical behaviors of LCMs will be affected remarkably by the parameters of driving voltage signal mentioned above. To implement these important functions flexibly and effectively, the driving voltage signal must be powerful and flexible. It had better to have multiple channels to control the direction of swinging focus, with relatively wide variance range to spread spectrum selection range, and with high precision to ensure accurately controlling LCMs. In addition, special waveforms may be required to support special functions of LCMs. Therefore a digital control device, which meet the requirements mentioned above, is designed, and then LCMs with it can realize imaging detection of targets in complex environment.

  4. Polarization-Insensitive Surface Plasmon Polarization Electro-Absorption Modulator Based on Epsilon-Near-Zero Indium Tin Oxide

    Science.gov (United States)

    Jin, Lin; Wen, Long; Liang, Li; Chen, Qin; Sun, Yunfei

    2018-02-01

    CMOS-compatible plasmonic modulators operating at the telecom wavelength are significant for a variety of on-chip applications. Relying on the manipulation of the transverse magnetic (TM) mode excited on the metal-dielectric interface, most of the previous demonstrations are designed to response only for specific polarization state. In this case, it will lead to a high polarization dependent loss, when the polarization-sensitive modulator integrates to a fiber with random polarization state. Herein, we propose a plasmonic modulator utilizing a metal-oxide indium tin oxide (ITO) wrapped around the silicon waveguide and investigate its optical modulation ability for both the vertical and horizontal polarized guiding light by tuning electro-absorption of ITO with the field-induced carrier injection. The electrically biased modulator with electron accumulated at the ITO/oxide interface allows for epsilon-near-zero (ENZ) mode to be excited at the top or lateral portion of the interface depending on the polarization state of the guiding light. Because of the high localized feature of ENZ mode, efficient electro-absorption can be achieved under the "OFF" state of the device, thus leading to large extinction ratio (ER) for both polarizations in our proposed modulator. Further, the polarization-insensitive modulation is realized by properly tailoring the thickness of oxide in two different stacking directions and therefore matching the ER values for device operating at vertical and horizontal polarized modes. For the optimized geometry configuration, the difference between the ER values of two polarization modes, i.e., the ΔER, as small as 0.01 dB/μm is demonstrated and, simultaneously with coupling efficiency above 74%, is obtained for both polarizations at a wavelength of 1.55 μm. The proposed plasmonic-combined modulator has a potential application in guiding and processing of light from a fiber with a random polarization state.

  5. Reactor control device

    International Nuclear Information System (INIS)

    Kinoshita, Mitsuo.

    1991-01-01

    Heretofore, since the aimed value of a reactor power has been determined only based on the deviation between a temperature variation coefficient and the aimed value, it involves a problem that a region for finely determining a control constant is complicated. In view of the above, in the present invention, an approximate value of the aimed reactor power value is determined based on the aimed value for the temperature variation coefficient, then a compensation value for the aimed power value is determined based on the deviation between the temperature variation coefficient and the aimed value and, further, the aimed power value is determined based on the approximate value and the compensation value. Control elements are automatically operated so that the power follows the aimed value after determining the aimed value. Then, since the aimed reactor power value is controlled finely so that the responsiveness of the temperature variation coefficient is satisfactory and the temperature variation coefficient agrees with the aimed value, the stability for the control of temperature variation coefficient is satisfactory. That is, high performance control is enabled by a simple control algorithm to reduce the number of the steps for the design and the device control. (N.H.)

  6. Temperature sensitivity analysis of polarity controlled electrostatically doped tunnel field-effect transistor

    Science.gov (United States)

    Nigam, Kaushal; Pandey, Sunil; Kondekar, P. N.; Sharma, Dheeraj

    2016-09-01

    The conventional tunnel field-effect transistors (TFETs) have shown potential to scale down in sub-22 nm regime due to its lower sub-threshold slope and robustness against short-channel effects (SCEs), however, sensitivity towards temperature variation is a major concern. Therefore, for the first time, we investigate temperature sensitivity analysis of a polarity controlled electrostatically doped tunnel field-effect transistor (ED-TFET). Different performance metrics and analog/RF figure-of-merits were considered and compared for both devices, and simulations were performed using Silvaco ATLAS device tool. We found that the variation in ON-state current in ED-TFET is almost temperature independent due to electrostatically doped mechanism, while, it increases in conventional TFET at higher temperature. Above room temperature, the variation in ION, IOFF, and SS sensitivity in ED-TFET are only 0.11%/K, 2.21%/K, and 0.63%/K, while, in conventional TFET the variations are 0.43%/K, 2.99%/K, and 0.71%/K, respectively. However, below room temperature, the variation in ED-TFET ION is 0.195%/K compared to 0.27%/K of conventional TFET. Moreover, it is analysed that the incomplete ionization effect in conventional TFET severely affects the drive current and the threshold voltage, while, ED-TFET remains unaffected. Hence, the proposed ED-TFET is less sensitive towards temperature variation and can be used for cryogenics as well as for high temperature applications.

  7. A magnetorheological fluid-based multifunctional haptic device for vehicular instrument controls

    International Nuclear Information System (INIS)

    Han, Young-Min; Kim, Chan-Jung; Choi, Seung-Bok

    2009-01-01

    This paper presents control performances of a magnetorheological (MR) fluid-based multifunctional haptic device which is applicable to vehicular instrument controls. By combining in-vehicle functions into a single device, the proposed haptic device can transmit various reflection forces for each comfort function to a driver without requiring the driver's visual attention. As a multifunctional haptic device, a MR knob is proposed in this work and then devised to be capable of both rotary and push motions with a single knob. Under consideration of the spatial limitations of vehicle dashboards, design parameters are optimally determined by finite element analysis, and the objective function is to maximize a relative control torque. The proposed haptic device is then manufactured, and in-vehicle comfort functions are constructed in a virtual environment which makes the functions to communicate with the haptic device. Subsequently, a feed-forward controller using torque/force maps is formulated for the force tracking control. Control performances such as reflection force of the haptic device are experimentally evaluated via the torque/force map-based feed-forward controller

  8. Micro-Scalable Thermal Control Device

    Science.gov (United States)

    Moran, Matthew E. (Inventor)

    2002-01-01

    A microscalable thermal control module consists of a Stirling cycle cooler that can be manipulated to operate at a selected temperature within the heating and cooling range of the module. The microscalable thermal control module is particularly suited for controlling the temperature of devices that must be maintained at precise temperatures. It is particularly suited for controlling the temperature of devices that need to be alternately heated or cooled. The module contains upper and lower opposing diaphragms, with a regenerator region containing a plurality of regenerators interposed between the diaphragms. Gaps exist on each side of each diaphragm to permit it to oscillate freely. The gap on the interior side one diaphragm is in fluid connection with the gap on the interior side of the other diaphragm through regenerators. As the diaphragms oscillate working gas is forced through the regenerators. The surface area of each regenerator is sufficiently large to effectively transfer thermal energy to and from the working gas as it is passed through them. The phase and amplitude of the oscillations can be manipulated electronically to control the steady state temperature of the active thermal control surface, and to switch the operation of the module from cooling to heating, or vice versa. The ability of the microscalable thermal control module to heat and cool may be enhanced by operating a plurality of modules in series, in parallel, or in connection through a shared bottom layer.

  9. Control system devices : architectures and supply channels overview.

    Energy Technology Data Exchange (ETDEWEB)

    Trent, Jason; Atkins, William Dee; Schwartz, Moses Daniel; Mulder, John C.

    2010-08-01

    This report describes a research project to examine the hardware used in automated control systems like those that control the electric grid. This report provides an overview of the vendors, architectures, and supply channels for a number of control system devices. The research itself represents an attempt to probe more deeply into the area of programmable logic controllers (PLCs) - the specialized digital computers that control individual processes within supervisory control and data acquisition (SCADA) systems. The report (1) provides an overview of control system networks and PLC architecture, (2) furnishes profiles for the top eight vendors in the PLC industry, (3) discusses the communications protocols used in different industries, and (4) analyzes the hardware used in several PLC devices. As part of the project, several PLCs were disassembled to identify constituent components. That information will direct the next step of the research, which will greatly increase our understanding of PLC security in both the hardware and software areas. Such an understanding is vital for discerning the potential national security impact of security flaws in these devices, as well as for developing proactive countermeasures.

  10. An electromagnetic helical undulator for polarized X-rays

    International Nuclear Information System (INIS)

    Gluskin, E.; Vinokurov, N.; Tcheskidov, V.; Medvedko, A.; Evtushenko, Y.; Kolomogorov, V.; Vobly, P.; Antokhin, E.; Ivanov, P.; Vasserman, I. B.; Trakhtenberg, E. M.; Den Hartog, P. K.; Deriy, B.; Erdmann, M.; Makarov, O.; Moog, E. R.

    1999-01-01

    Linearly and circularly polarized x-rays have been very successfully applied to the study of the properties of materials. Many applications can benefit from the availability of energy-turnable, high-brilliance x-ray beams with adjustable polarization properties. A helical undulator that can generate beams of variable (linear to circular) polarization has been designed and built by the Budker Institute of Nuclear Physics and the Advanced Photon Source. The first harmonic of this 12.8-cm-period device will cover the energy range from 0.4 keV to 3.5 keV. An important feature of this fully electromagnetic device is that it will allow one to generate 100% horizontally (K x =O)or vertically (K y =O) plane-polarized radiation, which will enable many experiments otherwise not technically feasible. With symmetric deflection parameters (K x =K y ), the on-axis radiation will be circularly polarized, with a user-selectable handedness. The polarization can be changed at rates up to 10 Hz

  11. Spherical ion oscillations in a positive polarity gridded inertial-electrostatic confinement device

    Energy Technology Data Exchange (ETDEWEB)

    Bandara, R.; Khachan, J. [Plasma Physics, School of Physics, University of Sydney, Camperdown, New South Wales 2006 (Australia)

    2013-07-15

    A pulsed, positive polarity gridded inertial electrostatic confinement device has been investigated experimentally, using a differential emissive probe and potential traces as primary diagnostics. Large amplitude oscillations in the plasma current and plasma potential were observed within a microsecond of the discharge onset, which are indicative of coherent ion oscillations about a temporarily confined excess of recirculating electron space charge. The magnitude of the depth of the potential well in the established virtual cathode was determined using a differential emissive Langmuir probe, which correlated well to the potential well inferred from the ion oscillation frequency for both hydrogen and argon experiments. It was found that the timescale for ion oscillation dispersion is strongly dependent on the neutral gas density, and weakly dependent on the peak anode voltage. The cessation of the oscillations was found to be due to charge exchange processes converting ions to high velocity neutrals, causing the abrupt de-coherence of the oscillations through an avalanche dispersion in phase space.

  12. Spherical ion oscillations in a positive polarity gridded inertial-electrostatic confinement device

    Science.gov (United States)

    Bandara, R.; Khachan, J.

    2013-07-01

    A pulsed, positive polarity gridded inertial electrostatic confinement device has been investigated experimentally, using a differential emissive probe and potential traces as primary diagnostics. Large amplitude oscillations in the plasma current and plasma potential were observed within a microsecond of the discharge onset, which are indicative of coherent ion oscillations about a temporarily confined excess of recirculating electron space charge. The magnitude of the depth of the potential well in the established virtual cathode was determined using a differential emissive Langmuir probe, which correlated well to the potential well inferred from the ion oscillation frequency for both hydrogen and argon experiments. It was found that the timescale for ion oscillation dispersion is strongly dependent on the neutral gas density, and weakly dependent on the peak anode voltage. The cessation of the oscillations was found to be due to charge exchange processes converting ions to high velocity neutrals, causing the abrupt de-coherence of the oscillations through an avalanche dispersion in phase space.

  13. Room Temperature Memory for Few Photon Polarization Qubits

    Science.gov (United States)

    Kupchak, Connor; Mittiga, Thomas; Jordan, Bertus; Nazami, Mehdi; Nolleke, Christian; Figueroa, Eden

    2014-05-01

    We have developed a room temperature quantum memory device based on Electromagnetically Induced Transparency capable of reliably storing and retrieving polarization qubits on the few photon level. Our system is realized in a vapor of 87Rb atoms utilizing a Λ-type energy level scheme. We create a dual-rail storage scheme mediated by an intense control field to allow storage and retrieval of any arbitrary polarization state. Upon retrieval, we employ a filtering system to sufficiently remove the strong pump field, and subject retrieved light states to polarization tomography. To date, our system has produced signal-to-noise ratios near unity with a memory fidelity of >80 % using coherent state qubits containing four photons on average. Our results thus demonstrate the feasibility of room temperature systems for the storage of single-photon-level photonic qubits. Such room temperature systems will be attractive for future long distance quantum communication schemes.

  14. Imaging and tuning polarity at SrTiO3 domain walls

    Science.gov (United States)

    Frenkel, Yiftach; Haham, Noam; Shperber, Yishai; Bell, Christopher; Xie, Yanwu; Chen, Zhuoyu; Hikita, Yasuyuki; Hwang, Harold Y.; Salje, Ekhard K. H.; Kalisky, Beena

    2017-12-01

    Electrostatic fields tune the ground state of interfaces between complex oxide materials. Electronic properties, such as conductivity and superconductivity, can be tuned and then used to create and control circuit elements and gate-defined devices. Here we show that naturally occurring twin boundaries, with properties that are different from their surrounding bulk, can tune the LaAlO3/SrTiO3 interface 2DEG at the nanoscale. In particular, SrTiO3 domain boundaries have the unusual distinction of remaining highly mobile down to low temperatures, and were recently suggested to be polar. Here we apply localized pressure to an individual SrTiO3 twin boundary and detect a change in LaAlO3/SrTiO3 interface current distribution. Our data directly confirm the existence of polarity at the twin boundaries, and demonstrate that they can serve as effective tunable gates. As the location of SrTiO3 domain walls can be controlled using external field stimuli, our findings suggest a novel approach to manipulate SrTiO3-based devices on the nanoscale.

  15. A Si nanocube array polarizer

    Science.gov (United States)

    Chen, Linghua; Jiang, Yingjie; Xing, Li; Yao, Jun

    2017-10-01

    We have proposed a full dielectric (silicon) nanocube array polarizer based on a silicon dioxide substrate. Each polarization unit column includes a plurality of equal spaced polarization units. By optimizing the length, the width, the height of the polarization units and the center distance of adjacent polarization unit (x direction and y direction), an extinction ratio (ER) of higher than 25dB was obtained theoretically when the incident light wavelength is 1550nm. while for applications of most polarization optical elements, ER above 10dB is enough. With this condition, the polarizer we designed can work in a wide wavelength range from 1509.31nm to 1611.51nm. Compared with the previous polarizer, we have introduced a polarizer which is a full dielectric device, which solves the problems of low efficiency caused by Ohmic loss and weak coupling. Furthermore, compared with the existing optical polarizers, our polarizer has the advantages of thin thickness, small size, light weight, and low processing difficulty, which is in line with the future development trend of optical elements.

  16. Automatic control device for the reduction of reactor power

    International Nuclear Information System (INIS)

    Sumida, Susumu; Mizuno, Hiroshi.

    1982-01-01

    Purpose: To early detect troubles in condensate pipeways and feedwater pipeways of BWR-type reactor. Constitution: Detectors are provided to a condensate pipe, a condensator, a low pressure condensate pump, a condensate desalting device and a high pressure condensate pump for constituting condensate pipeways, as well as to a feedwater heater, a feedwater pipe and a feedwater pump for constituting feedwater pipeways. Each of the detectors is connected by way of a lead wire to an abnormal detection and processing device. The abnormal detection and processing device, which are connected to a recycling control device, monitor the input from the detector and sends a control signal to the recycling control system upon calculation of a trouble signal from the detector. (Sekiya, K.)

  17. Planar Cell Polarity Controls Pancreatic Beta Cell Differentiation and Glucose Homeostasis

    Directory of Open Access Journals (Sweden)

    Cedric Cortijo

    2012-12-01

    Full Text Available Planar cell polarity (PCP refers to the collective orientation of cells within the epithelial plane. We show that progenitor cells forming the ducts of the embryonic pancreas express PCP proteins and exhibit an active PCP pathway. Planar polarity proteins are acquired at embryonic day 11.5 synchronously to apicobasal polarization of pancreas progenitors. Loss of function of the two PCP core components Celsr2 and Celsr3 shows that they control the differentiation of endocrine cells from polarized progenitors, with a prevalent effect on insulin-producing beta cells. This results in a decreased glucose clearance. Loss of Celsr2 and 3 leads to a reduction of Jun phosphorylation in progenitors, which, in turn, reduces beta cell differentiation from endocrine progenitors. These results highlight the importance of the PCP pathway in cell differentiation in vertebrates. In addition, they reveal that tridimensional organization and collective communication of cells are needed in the pancreatic epithelium in order to generate appropriate numbers of endocrine cells.

  18. Polarization-independent all-silicon dielectric metasurfaces in the terahertz regime

    KAUST Repository

    Zhang, Huifang

    2017-12-11

    Dielectric metasurfaces have achieved great success in realizing high-efficiency wavefront control in the optical and infrared ranges. Here, we experimentally demonstrate several efficient, polarization-independent, all-silicon dielectric metasurfaces in the terahertz regime. The metasurfaces are composed of cylindrical silicon pillars on a silicon substrate, which can be easily fabricated using etching technology for semiconductors. By locally tailoring the diameter of the pillars, full control over abrupt phase changes can be achieved. To show the controlling ability of the metasurfaces, an anomalous deflector, three Bessel beam generators, and three vortex beam generators are fabricated and characterized. We also show that the proposed metasurfaces can be easily combined to form composite devices with extended functionalities. The proposed controlling method has promising applications in developing low-loss, ultra-compact spatial terahertz modulation devices. (C) 2017 Chinese Laser Press

  19. Polarization-independent all-silicon dielectric metasurfaces in the terahertz regime

    KAUST Repository

    Zhang, Huifang; Zhang, Xueqian; Xu, Quan; Wang, Qiu; Xu, Yuehong; Wei, Minggui; Li, Yanfeng; Gu, Jianqiang; Tian, Zhen; Ouyang, Chunmei; Zhang, Xixiang; Hu, Cong; Han, Jiaguang; Zhang, Weili

    2017-01-01

    Dielectric metasurfaces have achieved great success in realizing high-efficiency wavefront control in the optical and infrared ranges. Here, we experimentally demonstrate several efficient, polarization-independent, all-silicon dielectric metasurfaces in the terahertz regime. The metasurfaces are composed of cylindrical silicon pillars on a silicon substrate, which can be easily fabricated using etching technology for semiconductors. By locally tailoring the diameter of the pillars, full control over abrupt phase changes can be achieved. To show the controlling ability of the metasurfaces, an anomalous deflector, three Bessel beam generators, and three vortex beam generators are fabricated and characterized. We also show that the proposed metasurfaces can be easily combined to form composite devices with extended functionalities. The proposed controlling method has promising applications in developing low-loss, ultra-compact spatial terahertz modulation devices. (C) 2017 Chinese Laser Press

  20. Heterodyne detector for measuring the characteristic of elliptically polarized microwaves

    DEFF Research Database (Denmark)

    Leipold, Frank; Nielsen, Stefan Kragh; Michelsen, Susanne

    2008-01-01

    In the present paper, a device is introduced, which is capable of determining the three characteristic parameters of elliptically polarized light (ellipticity, angle of ellipticity, and direction of rotation) for microwave radiation at a frequency of 110 GHz. The device consists of two perpendicu......In the present paper, a device is introduced, which is capable of determining the three characteristic parameters of elliptically polarized light (ellipticity, angle of ellipticity, and direction of rotation) for microwave radiation at a frequency of 110 GHz. The device consists of two...... be calculated. Results from measured and calculated wave characteristics of an elliptically polarized 110 GHz microwave beam for plasma heating launched into the TEXTOR-tokamak experiment are presented. Measurement and calculation are in good agreement. ©2008 American Institute of Physics...

  1. Power control device of an atomic power plant

    International Nuclear Information System (INIS)

    Ootsuka, Shiro; Ito, Takero.

    1980-01-01

    Purpose: To improve the power controllability of an atomic power plant by improving the controllability, response and stability of the recirculation flow rate. Constitution: The power control device comprises a power detector of the reactor, which detects and operates the reactor power from the thermal power, neutron flux or the process quantity controlling the same, and a deviation detector which seeks deviation between the power signal of the power detector and the power set value of the reactor or power station. By use of the power control device constituted in this manner, the core flow rate is regulated by the power signal of the deviation detector thereby to control the power. (Aizawa, K.)

  2. Techniques of production and analysis of polarized synchrotron radiation

    International Nuclear Information System (INIS)

    Mills, D.M.

    1992-01-01

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

  3. Piezotronic Effect in Polarity-Controlled GaN Nanowires.

    Science.gov (United States)

    Zhao, Zhenfu; Pu, Xiong; Han, Changbao; Du, Chunhua; Li, Linxuan; Jiang, Chunyan; Hu, Weiguo; Wang, Zhong Lin

    2015-08-25

    Using high-quality and polarity-controlled GaN nanowires (NWs), we studied the piezotronic effect in crystal orientation defined wurtzite structures. By applying a normal compressive force on c-plane GaN NWs with an atomic force microscopy tip, the Schottky barrier between the Pt tip and GaN can be effectively tuned by the piezotronic effect. In contrast, the normal compressive force cannot change the electron transport characteristics in m-plane GaN NWs whose piezoelectric polarization axis is turned in the transverse direction. This observation provided solid evidence for clarifying the difference between the piezotronic effect and the piezoresistive effect. We further demonstrated a high sensitivity of the m-plane GaN piezotronic transistor to collect the transverse force. The integration of c-plane GaN and m-plane GaN indicates an overall response to an external force in any direction.

  4. 2D Semiconductors for Valley-Polarized LEDs and Photodetectors

    Science.gov (United States)

    Yu, Ting

    The recently discovered two-dimensional (2D) semiconductors, such as transitional-metal-dichalcogenide monolayers, have aroused great interest due to the underlying quantum physics and the appealing optoelectronic applications like atomically thin light-emitting diodes (LEDs) and photodetectors. On the one hand, valley-polarized electroluminescence and photocurrent from such monolayers have not caused enough attention but highly demanded as building blocks for the new generation valleytronic applications. On the other hand, most reports on these devices are based on the mechanically exfoliated small samples. Considering real applications, a strategy which could offer mass-product and high compatibility to the current planar processes is greatly demanded. Large-area samples prepared by chemical vapour deposition (CVD) are perfect candidates towards such a goal. Here, we report electrically tunable valley-polarized electroluminescence and the selective spin-valley-coupled photocurrent in optoelectronic devices based on monolayer WS2 and MoS2 grown by CVD, exhibiting large electroluminescence and photocurrent dichroisms of 81% and 60%, respectively. The controllable valley polarization and emission components of the electroluminescence have been realized by varying electrical injection of carriers. For the observed helicity-dependent photocurrent, the circular photogalvanic effect at resonant excitations has been found to take the dominant responsibility.

  5. Optically controlled multiple switching operations of DNA biopolymer devices

    International Nuclear Information System (INIS)

    Hung, Chao-You; Tu, Waan-Ting; Lin, Yi-Tzu; Fruk, Ljiljana; Hung, Yu-Chueh

    2015-01-01

    We present optically tunable operations of deoxyribonucleic acid (DNA) biopolymer devices, where a single high-resistance state, write-once read-many-times memory state, write-read-erase memory state, and single low-resistance state can be achieved by controlling UV irradiation time. The device is a simple sandwich structure with a spin-coated DNA biopolymer layer sandwiched by two electrodes. Upon irradiation, the electrical properties of the device are adjusted owing to a phototriggered synthesis of silver nanoparticles in DNA biopolymer, giving rise to multiple switching scenarios. This technique, distinct from the strategy of doping of pre-formed nanoparticles, enables a post-film fabrication process for achieving optically controlled memory device operations, which provides a more versatile platform to fabricate organic memory and optoelectronic devices

  6. Optically controlled multiple switching operations of DNA biopolymer devices

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Chao-You; Tu, Waan-Ting; Lin, Yi-Tzu [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Fruk, Ljiljana [Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA (United Kingdom); Hung, Yu-Chueh, E-mail: ychung@ee.nthu.edu.tw [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2015-12-21

    We present optically tunable operations of deoxyribonucleic acid (DNA) biopolymer devices, where a single high-resistance state, write-once read-many-times memory state, write-read-erase memory state, and single low-resistance state can be achieved by controlling UV irradiation time. The device is a simple sandwich structure with a spin-coated DNA biopolymer layer sandwiched by two electrodes. Upon irradiation, the electrical properties of the device are adjusted owing to a phototriggered synthesis of silver nanoparticles in DNA biopolymer, giving rise to multiple switching scenarios. This technique, distinct from the strategy of doping of pre-formed nanoparticles, enables a post-film fabrication process for achieving optically controlled memory device operations, which provides a more versatile platform to fabricate organic memory and optoelectronic devices.

  7. Highly tunable local gate controlled complementary graphene device performing as inverter and voltage controlled resistor.

    Science.gov (United States)

    Kim, Wonjae; Riikonen, Juha; Li, Changfeng; Chen, Ya; Lipsanen, Harri

    2013-10-04

    Using single-layer CVD graphene, a complementary field effect transistor (FET) device is fabricated on the top of separated back-gates. The local back-gate control of the transistors, which operate with low bias at room temperature, enables highly tunable device characteristics due to separate control over electrostatic doping of the channels. Local back-gating allows control of the doping level independently of the supply voltage, which enables device operation with very low VDD. Controllable characteristics also allow the compensation of variation in the unintentional doping typically observed in CVD graphene. Moreover, both p-n and n-p configurations of FETs can be achieved by electrostatic doping using the local back-gate. Therefore, the device operation can also be switched from inverter to voltage controlled resistor, opening new possibilities in using graphene in logic circuitry.

  8. Injection and detection of a spin-polarized current in a light-emitting diode

    Science.gov (United States)

    Fiederling, R.; Keim, M.; Reuscher, G.; Ossau, W.; Schmidt, G.; Waag, A.; Molenkamp, L. W.

    1999-12-01

    The field of magnetoelectronics has been growing in practical importance in recent years. For example, devices that harness electronic spin-such as giant-magnetoresistive sensors and magnetoresistive memory cells-are now appearing on the market. In contrast, magnetoelectronic devices based on spin-polarized transport in semiconductors are at a much earlier stage of development, largely because of the lack of an efficient means of injecting spin-polarized charge. Much work has focused on the use of ferromagnetic metallic contacts, but it has proved exceedingly difficult to demonstrate polarized spin injection. More recently, two groups have reported successful spin injection from an NiFe contact, but the observed effects of the spin-polarized transport were quite small (resistance changes of less than 1%). Here we describe a different approach, in which the magnetic semiconductor BexMnyZn1-x-ySe is used as a spin aligner. We achieve injection efficiencies of 90% spin-polarized current into a non-magnetic semiconductor device. The device used in this case is a GaAs/AlGaAs light-emitting diode, and spin polarization is confirmed by the circular polarization state of the emitted light.

  9. Polarity Control and Growth of Lateral Polarity Structures in AlN

    Science.gov (United States)

    2013-05-10

    devices similar to those predicted for GaN.5 This could include high-power and high-frequency field effect transistors, efficient ultraviolet ( UV ) light...emitting diodes, or UV -laser light generation via frequency doubling.6 A few prerequisites are lateral control on the micrometer or even nanometer...the limited lateral resolution of micro Raman spectros - copy, no spectra could be obtained from the inversion domain boundary.9 Spectra were recorded

  10. Fast, high-fidelity, all-optical and dynamically-controlled polarization gate using room-temperature atomic vapor

    Energy Technology Data Exchange (ETDEWEB)

    Li, Runbing [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071 (China); Zhu, Chengjie [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Deng, L.; Hagley, E. W. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

    2014-10-20

    We demonstrate a fast, all-optical polarization gate in a room-temperature atomic medium. Using a Polarization-Selective-Kerr-Phase-Shift (PSKPS) technique, we selectively write a π phase shift to one circularly-polarized component of a linearly-polarized input signal field. The output signal field maintains its original strength but acquires a 90° linear polarization rotation, demonstrating fast, high-fidelity, dynamically-controlled polarization gate operation. The intensity of the polarization-switching field used in this PKSPK-based polarization gate operation is only 2 mW/cm{sup 2}, which would be equivalent to 0.5 nW of light power (λ = 800 nm) confined in a typical commercial photonic hollow-core fiber. This development opens a realm of possibilities for potential future extremely low light level telecommunication and information processing systems.

  11. Characterization Of Graphene-Ferroelectric Superlattice Hybrid Devices

    Science.gov (United States)

    Yusuf, Mohammed; Du, Xu; Dawber, Matthew

    2013-03-01

    Ferroelectric materials possess a spontaneous electrical polarization, which can be controlled by an electric field. A good interface between ferroelectric surface and graphene sheets can introduce a new generation of multifunctional devices, in which the ferroelectric material can be used to control the properties of graphene. In our approach, problems encountered in previous efforts to combine ferroelectric/carbon systems are overcome by the use of artificially layered superlattice materials grown in the form of epitaxial thin films. In these materials the phase transition temperature and dielectric response of the material can be tailored, allowing us to avoid polarization screening by surface absorbates, whilst maintaining an atomically smooth surface and optimal charge doping properties. Using ferroelectric PbTiO3/SrTiO3 superlattices, we have shown ultra-low-voltage operation of graphene field effect devices within +/- 1 V at room temperature. The switching of the graphene field effect transistors is characterized by pronounced resistance hysteresis, suitable for ultra-fast non-volatile electronics. Low temperature characterization confirmed that the coercive field required for the ferroelectric domain switching increases significantly with decreasing temperatures. National Science Foundation (NSF) (grant number 1105202)

  12. Compact Design of an Electrically Tunable and Rotatable Polarizer Based on a Liquid Crystal Photonic Bandgap Fiber

    DEFF Research Database (Denmark)

    Wei, Lei; Alkeskjold, Thomas Tanggaard; Bjarklev, Anders Overgaard

    2009-01-01

    In this letter, a compact electrically controlled broadband liquid crystal (LC) photonic bandgap fiber polarizer is designed and fabricated. A good fiber coupling quality between two single-mode fibers and one 10-mm-long LC-filled photonic crystal fiber is obtained and protected by using SU-8 fiber...... fixing structures during the device assembly. The total insertion loss of this all-in-fiber device is 2.7 dB. An electrically tunable polarization extinction ratio of 21.3 dB is achieved with 45$^{circ}$ rotatable transmission axis as well as switched on and off in the wavelength range of 1300–1600 nm....

  13. Device provides controlled gas leaks

    Science.gov (United States)

    Kami, S. K.; King, H. J.

    1968-01-01

    Modified palladium leak device provides a controlled release /leak/ of very small quantities of gas at low or medium pressures. It has no moving parts, requires less than 5 watts to operate, and is capable of releasing the gas either continuously or in pulses at adjustable flow rates.

  14. Integrated-optic current sensors with a multimode interference waveguide device.

    Science.gov (United States)

    Kim, Sung-Moon; Chu, Woo-Sung; Kim, Sang-Guk; Oh, Min-Cheol

    2016-04-04

    Optical current sensors based on polarization-rotated reflection interferometry are demonstrated using polymeric integrated optics and various functional optical waveguide devices. Interferometric sensors normally require bias feedback control for maintaining the operating point, which increases the cost. In order to resolve this constraint of feedback control, a multimode interference (MMI) waveguide device is integrated onto the current-sensor optical chip in this work. From the multiple outputs of the MMI, a 90° phase-shifted transfer function is obtained. Using passive quadrature demodulation, we demonstrate that the sensor could maintain the output signal regardless of the drift in the operating bias-point.

  15. Spin polarized electron tunneling and magnetoresistance in molecular junctions.

    Science.gov (United States)

    Szulczewski, Greg

    2012-01-01

    This chapter reviews tunneling of spin-polarized electrons through molecules positioned between ferromagnetic electrodes, which gives rise to tunneling magnetoresistance. Such measurements yield important insight into the factors governing spin-polarized electron injection into organic semiconductors, thereby offering the possibility to manipulate the quantum-mechanical spin degrees of freedom for charge carriers in optical/electrical devices. In the first section of the chapter a brief description of the Jullière model of spin-dependent electron tunneling is reviewed. Next, a brief description of device fabrication and characterization is presented. The bulk of the review highlights experimental studies on spin-polarized electron tunneling and magnetoresistance in molecular junctions. In addition, some experiments describing spin-polarized scanning tunneling microscopy/spectroscopy on single molecules are mentioned. Finally, some general conclusions and prospectus on the impact of spin-polarized tunneling in molecular junctions are offered.

  16. Planar Cell Polarity Controls Pancreatic Beta Cell Differentiation and Glucose Homeostasis

    DEFF Research Database (Denmark)

    Cortijo, Cedric; Gouzi, Mathieu; Tissir, Fadel

    2012-01-01

    glucose clearance. Loss of Celsr2 and 3 leads to a reduction of Jun phosphorylation in progenitors, which, in turn, reduces beta cell differentiation from endocrine progenitors. These results highlight the importance of the PCP pathway in cell differentiation in vertebrates. In addition, they reveal.......5 synchronously to apicobasal polarization of pancreas progenitors. Loss of function of the two PCP core components Celsr2 and Celsr3 shows that they control the differentiation of endocrine cells from polarized progenitors, with a prevalent effect on insulin-producing beta cells. This results in a decreased...

  17. Control of polarization and dipole moment in low-dimensional semiconductor nanostructures

    International Nuclear Information System (INIS)

    Li, L. H.; Ridha, P.; Mexis, M.; Smowton, P. M.; Blood, P.; Bozkurt, M.; Koenraad, P. M.; Patriarche, G.; Fiore, A.

    2009-01-01

    We demonstrate the control of polarization and dipole moment in semiconductor nanostructures, through nanoscale engineering of shape and composition. Rodlike nanostructures, elongated along the growth direction, are obtained by molecular beam epitaxial growth. By varying the aspect ratio and compositional contrast between the rod and the surrounding matrix, we rotate the polarization of the dominant interband transition from transverse-electric to transverse-magnetic, and modify the dipole moment producing a radical change in the voltage dependence of absorption spectra. This opens the way to the optimization of quantum dot amplifiers and electro-optical modulators.

  18. Generation of arbitrary vector beams with liquid crystal polarization converters and vector-photoaligned q-plates

    International Nuclear Information System (INIS)

    Chen, Peng; Ji, Wei; Wei, Bing-Yan; Hu, Wei; Lu, Yan-Qing; Chigrinov, Vladimir

    2015-01-01

    Arbitrary vector beams (VBs) are realized by the designed polarization converters and corresponding vector-photoaligned q-plates. The polarization converter is a specific twisted nematic cell with one substrate homogeneously aligned and the other space-variantly aligned. By combining a polarization-sensitive alignment agent with a dynamic micro-lithography system, various categories of liquid crystal polarization converters are demonstrated. Besides, traditional radially/azimuthally polarized light, high-order and multi-ringed VBs, and a VB array with different orders are generated. The obtained converters are further utilized as polarization masks to implement vector-photoaligning. The technique facilitates both the volume duplication of these converters and the generation of another promising optical element, the q-plate, which is suitable for the generation of VBs for coherent lasers. The combination of proposed polarization converters and correspondingly fabricated q-plates would drastically enhance the capability of polarization control and may bring more possibilities for the design of photonic devices

  19. The laser control system for the TRIUMF optically pumped polarized H- ion source

    International Nuclear Information System (INIS)

    Kadantsev, S.G.; Levy, C.D.P.; Mouat, M.M.

    1994-08-01

    The optically pumped polarized H - ion source at TRIUMF produces up to 100 μΑ dc of 78% polarized beam within an emittance of 1.0 π mm mrad and is now being prepared for an upcoming experiment at TRIUMF that will measure parity violation in pp scattering at 230 MeV. The optical pumping is accomplished by argon laser pumped Ti-sapphire lasers. The laser control system provides monitoring and precision control of the lasers for fast spin reversal up to 200 s -1 . To solve the problems of laser power and frequency stabilization during fast spin flipping, techniques and algorithms have been developed that significantly reduce the variation of laser frequency and power between spin states. The upgraded Faraday rotation system allows synchronous measurement of Rb thickness and polarization while spin flipping. The X Window environment provides both local and remote control to laser operators via a local area network and X window terminals. In this new environment issues such as access authorization, response time, operator interface consistency and ease of use are of particular importance. (author)

  20. Reactor power control device

    International Nuclear Information System (INIS)

    Doi, Kazuyori.

    1981-01-01

    Purpose: To automatically control the BWR type reactor power by simple and short-time searching the load pattern nearest to the required pattern at a nuclear power plant side. Constitution: The reactor power is automatically regulated by periodical modifying of coefficients fitting to a reactor core model, according as a required load pattern. When a load requirement pattern is given, a simulator estimates the total power change and the axial power distribution change from a xenon density change output calculated by a xenon dynamic characteristic estimating device, and a load pattern capable of being realized is searched. The amount to be recirculated is controlled on the basis of the load patteren thus searched, and the operation of the BWR type reactor is automatically controlled at the side of the nuclear power plant. (Kamimura, M.)

  1. Polarization control method for UV writing of advanced bragg gratings

    DEFF Research Database (Denmark)

    Deyerl, Hans-Jürgen; Plougmann, Nikolai; Jensen, Jesper Bo Damm

    2002-01-01

    We report the application of the polarization control method for the UV writing of advanced fiber Bragg gratings (FBG). We demonstrate the strength of the new method for different apodization profiles, including the Sinc-profile and two designs for dispersion-free square filters. The method has...

  2. Efficient composite broadband polarization retarders and polarization filters

    Science.gov (United States)

    Dimova, E.; Ivanov, S. S.; Popkirov, G.; Vitanov, N. V.

    2014-12-01

    A new type of broadband polarization half-wave retarder and narrowband polarization filters are described and experimentally tested. Both, the retarders and the filters are designed as composite stacks of standard optical half-wave plates, each of them twisted at specific angles. The theoretical background of the proposed optical devices was obtained by analogy with the method of composite pulses, known from the nuclear and quantum physics. We show that combining two composite filters built from different numbers and types of waveplates, the transmission spectrum is reduced from about 700 nm to about 10 nm width.We experimentally demonstrate that this method can be applied to different types of waveplates (broadband, zero-order, multiple order, etc.).

  3. Topological induced valley polarization in bilayer graphene/Boron Nitride

    Science.gov (United States)

    Basile, Leonardo; Idrobo, Juan C.

    2015-03-01

    Novel electronic devices relay in our ability to control internal quantum degrees of freedom of the electron e.g., its spin. The valley number degree of freedom is a pseudospin that labels degenerate eigenstates at local maximum/minimum on the valence/conduction band. Valley polarization, that is, selective electronic localization in a momentum valley and its manipulation can be achieved by means of circular polarized light (CPL) in a system with strong spin-orbit coupling (SOC). In this talk, we will show theoretically that despite the fact that neither graphene or BN have a strong SOC, a bilayer of graphene on BN oriented at a twist angle has different absorption for right- and left- CPL. This induced polarization occurs due to band folding of the electronic bands, i.e., it has a topological origin. This research was supported EPN multidisciplinary grant and by DOE SUFD MSED.

  4. Simple and robust generation of ultrafast laser pulse trains using polarization-independent parallel-aligned thin films

    Science.gov (United States)

    Wang, Andong; Jiang, Lan; Li, Xiaowei; Wang, Zhi; Du, Kun; Lu, Yongfeng

    2018-05-01

    Ultrafast laser pulse temporal shaping has been widely applied in various important applications such as laser materials processing, coherent control of chemical reactions, and ultrafast imaging. However, temporal pulse shaping has been limited to only-in-lab technique due to the high cost, low damage threshold, and polarization dependence. Herein we propose a novel design of ultrafast laser pulse train generation device, which consists of multiple polarization-independent parallel-aligned thin films. Various pulse trains with controllable temporal profile can be generated flexibly by multi-reflections within the splitting films. Compared with other pulse train generation techniques, this method has advantages of compact structure, low cost, high damage threshold and polarization independence. These advantages endow it with high potential for broad utilization in ultrafast applications.

  5. Nuclear physics with polarized particles

    CERN Document Server

    Paetz gen Schieck, Hans

    2012-01-01

    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...

  6. Self-adaptive demodulation for polarization extinction ratio in distributed polarization coupling.

    Science.gov (United States)

    Zhang, Hongxia; Ren, Yaguang; Liu, Tiegen; Jia, Dagong; Zhang, Yimo

    2013-06-20

    A self-adaptive method for distributed polarization extinction ratio (PER) demodulation is demonstrated. It is characterized by dynamic PER threshold coupling intensity (TCI) and nonuniform PER iteration step length (ISL). Based on the preset PER calculation accuracy and original distribution coupling intensity, TCI and ISL can be made self-adaptive to determine contributing coupling points inside the polarizing devices. Distributed PER is calculated by accumulating those coupling points automatically and selectively. Two different kinds of polarization-maintaining fibers are tested, and PERs are obtained after merely 3-5 iterations using the proposed method. Comparison experiments with Thorlabs commercial instrument are also conducted, and results show high consistency. In addition, the optimum preset PER calculation accuracy of 0.05 dB is obtained through many repeated experiments.

  7. Thermal stability of tunneling spin polarization

    International Nuclear Information System (INIS)

    Kant, C.H.; Kohlhepp, J.T.; Paluskar, P.V.; Swagten, H.J.M.; Jonge, W.J.M. de

    2005-01-01

    We present a study of the thermal stability of tunneling spin polarization in Al/AlOx/ferromagnet junctions based on the spin-polarized tunneling technique, in which the Zeeman-split superconducting density of states in the Al electrode is used as a detector for the spin polarization. Thermal robustness of the polarization, which is of key importance for the performance of magnetic tunnel junction devices, is demonstrated for post-deposition anneal temperatures up to 500 o C with Co and Co 90 Fe 10 top electrodes, independent of the presence of an FeMn layer on top of the ferromagnet

  8. Medical Devices; Immunology and Microbiology Devices; Classification of the Assayed Quality Control Material for Clinical Microbiology Assays. Final order.

    Science.gov (United States)

    2017-07-27

    The Food and Drug Administration (FDA, Agency, or we) is classifying the assayed quality control material for clinical microbiology assays into class II (special controls). The special controls that will apply to the device are identified in this order and will be part of the codified language for the assayed quality control material for clinical microbiology assays' classification. The Agency is classifying the device into class II (special controls) to provide a reasonable assurance of safety and effectiveness of the device.

  9. Fast helicity switching of x-ray circular polarization at beamline P09 at PETRA III

    Energy Technology Data Exchange (ETDEWEB)

    Strempfer, J., E-mail: Joerg.Strempfer@desy.de; Mardegan, J. R. L.; Francoual, S.; Veiga, L. S. I.; Spitzbart, T.; Zink, H. [Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, 22603 Hamburg (Germany); Bouchenoire, L. [XMaS, ESRF, 6 rue Jules Horowitz, BP220, Grenoble 38043 (France); Department of Physics, University of Liverpool, Liverpool, L69 7ZE (United Kingdom)

    2016-07-27

    At the resonant scattering and diffraction beamline P09 at PETRA III/DESY, polarization manipulation in the X-ray energy range 3-13 keV is possible using wave-plates. Recently, fast flipping of circular polarization helicity using the Raspberry Pi controlled FPGA (PiLC) device developed at DESY and dedicated piezo-electric flippers has been commissioned. Functionality of the PiLC for XMCD and first XMCD measurements at the Fe K-and Dy-L{sub 3} absorption edges are presented.

  10. Forced Ion Migration for Chalcogenide Phase Change Memory Device

    Science.gov (United States)

    Campbell, Kristy A (Inventor)

    2013-01-01

    Non-volatile memory devices with two stacked layers of chalcogenide materials comprising the active memory device have been investigated for their potential as phase-change memories. The devices tested included GeTe/SnTe, Ge2Se3/SnTe, and Ge2Se3/SnSe stacks. All devices exhibited resistance switching behavior. The polarity of the applied voltage with respect to the SnTe or SnSe layer was critical to the memory switching properties, due to the electric field induced movement of either Sn or Te into the Ge-chalcogenide layer. One embodiment of the invention is a device comprising a stack of chalcogenide-containing layers which exhibit phase-change switching only after a reverse polarity voltage potential is applied across the stack causing ion movement into an adjacent layer and thus "activating" the device to act as a phase-change random access memory device or a reconfigurable electronics device when the applied voltage potential is returned to the normal polarity. Another embodiment of the invention is a device that is capable of exhibiting more than two data states.

  11. Polarization modulation based on the hybrid waveguide of graphene sandwiched structure

    Science.gov (United States)

    Yang, Junbo; Chen, Dingbo; Zhang, Jingjing; Zhang, Zhaojian; Huang, Jie

    2017-09-01

    Polarization beam splitter (PBS) plays an important role to realize beam control and modulation. A novel hybrid structure of graphene sandwiched waveguide is proposed to fulfill polarization manipulation and selection based on the refractive index engineering techniques. The fundamental mode of TM cannot be supported in this case. However, both TE and TM mode are excited and transmitting in the hybrid waveguide if the design parameters, including the waveguide width and the waveguide height, are changed. The incident wavelength largely affects the effective index, which results in supporting/not supporting the TM mode. The proposed design exhibits high extinction ratio, compact in size, flexible to control, compatible with CMOS process, and easy to be integrated with other optoelectronic devices, allowing it to be used in optical communication and optical information processing.

  12. Implementation of Adaptive Digital Controllers on Programmable Logic Devices

    Science.gov (United States)

    Gwaltney, David A.; King, Kenneth D.; Smith, Keary J.; Monenegro, Justino (Technical Monitor)

    2002-01-01

    Much has been made of the capabilities of FPGA's (Field Programmable Gate Arrays) in the hardware implementation of fast digital signal processing. Such capability also makes an FPGA a suitable platform for the digital implementation of closed loop controllers. Other researchers have implemented a variety of closed-loop digital controllers on FPGA's. Some of these controllers include the widely used proportional-integral-derivative (PID) controller, state space controllers, neural network and fuzzy logic based controllers. There are myriad advantages to utilizing an FPGA for discrete-time control functions which include the capability for reconfiguration when SRAM-based FPGA's are employed, fast parallel implementation of multiple control loops and implementations that can meet space level radiation tolerance requirements in a compact form-factor. Generally, a software implementation on a DSP (Digital Signal Processor) or microcontroller is used to implement digital controllers. At Marshall Space Flight Center, the Control Electronics Group has been studying adaptive discrete-time control of motor driven actuator systems using digital signal processor (DSP) devices. While small form factor, commercial DSP devices are now available with event capture, data conversion, pulse width modulated (PWM) outputs and communication peripherals, these devices are not currently available in designs and packages which meet space level radiation requirements. In general, very few DSP devices are produced that are designed to meet any level of radiation tolerance or hardness. The goal of this effort is to create a fully digital, flight ready controller design that utilizes an FPGA for implementation of signal conditioning for control feedback signals, generation of commands to the controlled system, and hardware insertion of adaptive control algorithm approaches. An alternative is required for compact implementation of such functionality to withstand the harsh environment

  13. 40 CFR 1700.14 - Marine Pollution Control Device (MPCD) Performance Standards. [Reserved

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Marine Pollution Control Device (MPCD... UNIFORM NATIONAL DISCHARGE STANDARDS FOR VESSELS OF THE ARMED FORCES Marine Pollution Control Device (MPCD) Performance Standards § 1700.14 Marine Pollution Control Device (MPCD) Performance Standards. [Reserved] ...

  14. Reactor power control device

    International Nuclear Information System (INIS)

    Imaruoka, Hiromitsu.

    1994-01-01

    A high pressure water injection recycling system comprising injection pipelines of a high pressure water injection system and a flow rate control means in communication with a pool of a pressure control chamber is disposed to a feedwater system of a BWR type reactor. In addition, the flow rate control means is controlled by a power control device comprising a scram impossible transient event judging section, a required injection flow rate calculation section for high pressure water injection system and a control signal calculation section. Feed water flow rate to be supplied to the reactor is controlled upon occurrence of a scram impossible transient event of the reactor. The scram impossible transient event is judged based on reactor output signals and scram operation demand signals and injection flow rate is calculated based on a predetermined reactor water level, and condensate storage tank water or pressure control chamber pool water is injected to the reactor. With such procedures, water level can be ensured and power can be suppressed. Further, condensate storage tank water of low enthalpy is introduced to the pressure suppression chamber pool to directly control elevation of water temperature and ensure integrity of the pressure vessel and the reactor container. (N.H.)

  15. Piezo Voltage Controlled Planar Hall Effect Devices.

    Science.gov (United States)

    Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K W; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

    2016-06-22

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

  16. Fast-acting nuclear reactor control device

    International Nuclear Information System (INIS)

    Kotlyar, O.M.; West, P.B.

    1993-01-01

    A fast-acting nuclear reactor control device is described for controlling a safety control rod within the core of a nuclear reactor, the reactor controlled by a reactor control system, the device comprising: a safety control rod drive shaft and an electromagnetic clutch co-axial with the drive shaft operatively connected to the safety control rod for driving and positioning the safety control rod within or without the reactor core during reactor operation, the safety rod being oriented in a substantially vertical position to allow the rod to fall into the reactor core under the influence of gravity during shutdown of the reactor; the safety control rod drive shaft further operatively connected to a hydraulic pump such that operation of the drive shaft simultaneously drives and positions the safety control rod and operates the hydraulic pump such that a hydraulic fluid is forced into an accumulator, filling the accumulator with oil for the storage and supply of primary potential energy for safety control rod insertion such that the release of potential energy in the accumulator causes hydraulic fluid to flow through the hydraulic pump, converting the hydraulic pump to a hydraulic motor having speed and power capable of full length insertion and high speed driving of the safety control rod into the reactor core; a solenoid valve interposed between the hydraulic pump and the accumulator, said solenoid valve being a normally open valve, actuated to close when the safety control rod is out of the reactor during reactor operation; and further wherein said solenoid opens in response to a signal from the reactor control system calling for shutdown of the reactor and rapid insertion of the safety control rod into the reactor core, such that the opening of the solenoid releases the potential energy in the accumulator to place the safety control rod in a safe shutdown position

  17. Flexible manipulation of terahertz wave reflection using polarization insensitive coding metasurfaces.

    Science.gov (United States)

    Jiu-Sheng, Li; Ze-Jiang, Zhao; Jian-Quan, Yao

    2017-11-27

    In order to extend to 3-bit encoding, we propose notched-wheel structures as polarization insensitive coding metasurfaces to control terahertz wave reflection and suppress backward scattering. By using a coding sequence of "00110011…" along x-axis direction and 16 × 16 random coding sequence, we investigate the polarization insensitive properties of the coding metasurfaces. By designing the coding sequences of the basic coding elements, the terahertz wave reflection can be flexibly manipulated. Additionally, radar cross section (RCS) reduction in the backward direction is less than -10dB in a wide band. The present approach can offer application for novel terahertz manipulation devices.

  18. Blazed vector gratings fabricated using photosensitive polymer liquid crystals and control of polarization diffraction

    Science.gov (United States)

    Ono, Hiroshi; Kuzuwata, Mitsuru; Sasaki, Tomoyuki; Noda, Kohei; Kawatsuki, Nobuhiro

    2014-03-01

    The blazed vector grating possessing antisymmetric distributions of the birefringence were fabricated by exposing the line-focused linearly polarized ultraviolet light on the photosensitive polymer liquid crystals. The polarization states of the diffraction beams can be highly and widely controlled by designing the blazed structures, and the diffraction properties were well-explained by Jones calculus.

  19. Semi-active control of helicopter vibration using controllable stiffness and damping devices

    Science.gov (United States)

    Anusonti-Inthra, Phuriwat

    Semi-active concepts for helicopter vibration reduction are developed and evaluated in this dissertation. Semi-active devices, controllable stiffness devices or controllable orifice dampers, are introduced; (i) in the blade root region (rotor-based concept) and (ii) between the rotor and the fuselage as semi-active isolators (in the non-rotating frame). Corresponding semi-active controllers for helicopter vibration reduction are also developed. The effectiveness of the rotor-based semi-active vibration reduction concept (using stiffness and damping variation) is demonstrated for a 4-bladed hingeless rotor helicopter in moderate- to high-speed forward flight. A sensitivity study shows that the stiffness variation of root element can reduce hub vibrations when proper amplitude and phase are used. Furthermore, the optimal semi-active control scheme can determine the combination of stiffness variations that produce significant vibration reduction in all components of vibratory hub loads simultaneously. It is demonstrated that desired cyclic variations in properties of the blade root region can be practically achieved using discrete controllable stiffness devices and controllable dampers, especially in the flap and lag directions. These discrete controllable devices can produce 35--50% reduction in a composite vibration index representing all components of vibratory hub loads. No detrimental increases are observed in the lower harmonics of blade loads and blade response (which contribute to the dynamic stresses) and controllable device internal loads, when the optimal stiffness and damping variations are introduced. The effectiveness of optimal stiffness and damping variations in reducing hub vibration is retained over a range of cruise speeds and for variations in fundamental rotor properties. The effectiveness of the semi-active isolator is demonstrated for a simplified single degree of freedom system representing the semi-active isolation system. The rotor

  20. Computer aided control of the Bonn Penning polarized ion source

    International Nuclear Information System (INIS)

    He, N.W.; VonRossen, P.; Eversheim, P.D.; Busch, R.

    1984-01-01

    A CBM computer system is described which has been set up to control the Bonn Polarized Ion Source. The controlling program, besides setting and logging parameters, performs an optimization of the ion source output. A free definable figure of merit, being composed of the current of the ionizer and its variance, has proven to be an effective means in directing the source optimization. The performance that has been reached during the first successful tests is reported

  1. Generating, Separating and Polarizing Terahertz Vortex Beams via Liquid Crystals with Gradient-Rotation Directors

    Directory of Open Access Journals (Sweden)

    Shi-Jun Ge

    2017-10-01

    Full Text Available Liquid crystal (LC is a promising candidate for terahertz (THz devices. Recently, LC has been introduced to generate THz vortex beams. However, the efficiency is intensely dependent on the incident wavelength, and the transformed THz vortex beam is usually mixed with the residual component. Thus, a separating process is indispensable. Here, we introduce a gradient blazed phase, and propose a THz LC forked polarization grating that can simultaneously generate and separate pure THz vortices with opposite circular polarization. The specific LC gradient-rotation directors are implemented by a photoalignment technique. The generated THz vortex beams are characterized with a THz imaging system, verifying features of polarization controllability. This work may pave a practical road towards generating, separating and polarizing THz vortex beams, and may prompt applications in THz communications, sensing and imaging.

  2. Fluid control structures in microfluidic devices

    Science.gov (United States)

    Mathies, Richard A.; Grover, William H.; Skelley, Alison; Lagally, Eric; Liu, Chung N.

    2017-05-09

    Methods and apparatus for implementing microfluidic analysis devices are provided. A monolithic elastomer membrane associated with an integrated pneumatic manifold allows the placement and actuation of a variety of fluid control structures, such as structures for pumping, isolating, mixing, routing, merging, splitting, preparing, and storing volumes of fluid. The fluid control structures can be used to implement a variety of sample introduction, preparation, processing, and storage techniques.

  3. Stabilizing device for control rod tip

    International Nuclear Information System (INIS)

    Verdone, G.F.

    1982-01-01

    A control rod has a spring device on its lower end for eliminating oscillatory contact of the rod against its adjacent guide tube wall. The base of the device is connected to the lower tip of the rod. A plurality of elongated extensions are cantilevered downward from the base. Each extension has a shoulder for contacting the guide tube, and the plurality of shoulders as a group has a transverse dimension that is preset to be larger than the inner diameter of the guide tube such that an interference fit is obtained when the control rod is inserted in the tube. The elongated extensions form an open-ended, substantially hollow member through which most of the liquid coolant flows, and the spaces between adjacent extensions allow the flow to bypass the shoulders without experiencing a significant pressure drop

  4. Control rod withdrawal monitoring device

    International Nuclear Information System (INIS)

    Ebisuya, Mitsuo.

    1984-01-01

    Purpose: To prevent the power ramp even if a plurality of control rods are subjected to withdrawal operation at a time, by reducing the reactivity applied to the reactor. Constitution: The control rod withdrawal monitoring device is adapted to monitor and control the withdrawal of the control rods depending on the reactor power and the monitoring region thereof is divided into a control rod group monitoring region a transition region and a control group monitoring not interfere region. In a case if the distance between a plurality of control rods for which the withdrawal positions are selected is less than a limiting value, the coordinate for the control rods, distance between the control rods and that the control rod distance is shorter are displayed on a display panel, and the withdrawal for the control rods are blocked. Accordingly, even if a plurality of control rods are subjected successively to the withdrawal operation contrary to the control rod withdrawal sequence upon high power operation of the reactor, the power ramp can be prevented. (Kawakami, Y.)

  5. Spin-polarized current generated by magneto-electrical gating

    International Nuclear Information System (INIS)

    Ma Minjie; Jalil, Mansoor Bin Abdul; Tan, Seng Ghee

    2012-01-01

    We theoretically study spin-polarized current through a single electron tunneling transistor (SETT), in which a quantum dot (QD) is coupled to non-magnetic source and drain electrodes via tunnel junctions, and gated by a ferromagnetic (FM) electrode. The I–V characteristics of the device are investigated for both spin and charge currents, based on the non-equilibrium Green's function formalism. The FM electrode generates a magnetic field, which causes a Zeeman spin-splitting of the energy levels in the QD. By tuning the size of the Zeeman splitting and the source–drain bias, a fully spin-polarized current is generated. Additionally, by modulating the electrical gate bias, one can effect a complete switch of the polarization of the tunneling current from spin-up to spin-down current, or vice versa. - Highlights: ► The spin polarized transport through a single electron tunneling transistor is systematically studied. ► The study is based on Keldysh non-equilibrium Green's function and equation of motion method. ► A fully spin polarized current is observed. ► We propose to reverse current polarization by the means of gate voltage modulation. ► This device can be used as a bi-polarization current generator.

  6. Control device for handling device of control rod drive

    International Nuclear Information System (INIS)

    Sasaki, Toshiya

    1998-01-01

    A predetermined aimed portion of control rod drives disposed in a pedestal is photographed, and image data and camera data including the position of the camera are outputted. Edge cut out processing image data are formed based on the outputted image data, and aimed image data and aimed camera data obtained when previously positioning the handling device precisely to a predetermined aimed position are stored. The aimed image data are taken out from the aimed image data file to prepare computer graphic image data, and there is disposed an image superposing processing portion for comparing images based on the computer graphic image data and images based on the image data for edge cut out processing, as well as comparing the aimed camera data and the camera data, and displaying each of them to an image display portion. (I.S.)

  7. Solar Illumination Control of the Polar Wind

    Science.gov (United States)

    Maes, L.; Maggiolo, R.; De Keyser, J.; André, M.; Eriksson, A. I.; Haaland, S.; Li, K.; Poedts, S.

    2017-11-01

    Polar wind outflow is an important process through which the ionosphere supplies plasma to the magnetosphere. The main source of energy driving the polar wind is solar illumination of the ionosphere. As a result, many studies have found a relation between polar wind flux densities and solar EUV intensity, but less is known about their relation to the solar zenith angle at the ionospheric origin, certainly at higher altitudes. The low energy of the outflowing particles and spacecraft charging means it is very difficult to measure the polar wind at high altitudes. We take advantage of an alternative method that allows estimations of the polar wind flux densities far in the lobes. We analyze measurements made by the Cluster spacecraft at altitudes from 4 up to 20 RE. We observe a strong dependence on the solar zenith angle in the ion flux density and see that both the ion velocity and density exhibit a solar zenith angle dependence as well. We also find a seasonal variation of the flux density.

  8. Circular dichroism measurements at an x-ray free-electron laser with polarization control

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, G.; Shevchuk, I.; Walter, P.; Viefhaus, J. [Deutsches Elektronen-Synchrotron, Notkestraße 85, 22607 Hamburg (Germany); Lindahl, A. O. [PULSE at Stanford, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Knie, A. [Institut für Physik, University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel (Germany); Hartmann, N.; Lutman, A. A.; MacArthur, J. P.; Glownia, J. M.; Helml, W.; Huang, Z.; Marinelli, A.; Nuhn, H.-D.; Moeller, S.; Coffee, R. N.; Ilchen, M., E-mail: markus.ilchen@xfel.eu [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Buck, J.; Galler, A.; Liu, J. [European XFEL GmbH, Albert-Einstein-Ring 19, 22761 Hamburg (Germany); and others

    2016-08-15

    A non-destructive diagnostic method for the characterization of circularly polarized, ultraintense, short wavelength free-electron laser (FEL) light is presented. The recently installed Delta undulator at the LCLS (Linac Coherent Light Source) at SLAC National Accelerator Laboratory (USA) was used as showcase for this diagnostic scheme. By applying a combined two-color, multi-photon experiment with polarization control, the degree of circular polarization of the Delta undulator has been determined. Towards this goal, an oriented electronic state in the continuum was created by non-resonant ionization of the O{sub 2} 1s core shell with circularly polarized FEL pulses at hν ≃ 700 eV. An also circularly polarized, highly intense UV laser pulse with hν ≃ 3.1 eV was temporally and spatially overlapped, causing the photoelectrons to redistribute into so-called sidebands that are energetically separated by the photon energy of the UV laser. By determining the circular dichroism of these redistributed electrons using angle resolving electron spectroscopy and modeling the results with the strong-field approximation, this scheme allows to unambiguously determine the absolute degree of circular polarization of any pulsed, ultraintense XUV or X-ray laser source.

  9. Circular dichroism measurements at an x-ray free-electron laser with polarization control

    Science.gov (United States)

    Hartmann, G.; Lindahl, A. O.; Knie, A.; Hartmann, N.; Lutman, A. A.; MacArthur, J. P.; Shevchuk, I.; Buck, J.; Galler, A.; Glownia, J. M.; Helml, W.; Huang, Z.; Kabachnik, N. M.; Kazansky, A. K.; Liu, J.; Marinelli, A.; Mazza, T.; Nuhn, H.-D.; Walter, P.; Viefhaus, J.; Meyer, M.; Moeller, S.; Coffee, R. N.; Ilchen, M.

    2016-08-01

    A non-destructive diagnostic method for the characterization of circularly polarized, ultraintense, short wavelength free-electron laser (FEL) light is presented. The recently installed Delta undulator at the LCLS (Linac Coherent Light Source) at SLAC National Accelerator Laboratory (USA) was used as showcase for this diagnostic scheme. By applying a combined two-color, multi-photon experiment with polarization control, the degree of circular polarization of the Delta undulator has been determined. Towards this goal, an oriented electronic state in the continuum was created by non-resonant ionization of the O2 1s core shell with circularly polarized FEL pulses at hν ≃ 700 eV. An also circularly polarized, highly intense UV laser pulse with hν ≃ 3.1 eV was temporally and spatially overlapped, causing the photoelectrons to redistribute into so-called sidebands that are energetically separated by the photon energy of the UV laser. By determining the circular dichroism of these redistributed electrons using angle resolving electron spectroscopy and modeling the results with the strong-field approximation, this scheme allows to unambiguously determine the absolute degree of circular polarization of any pulsed, ultraintense XUV or X-ray laser source.

  10. Investigation of focusing and correcting aberrations with binary amplitude and polarization modulation.

    Science.gov (United States)

    Fiala, Peter; Li, Yunqi; Dorrer, Christophe

    2018-02-01

    We investigate the focusing and correcting wavefront aberration of an optical wave using binary amplitude and polarization modulation. Focusing is performed by selectively modulating the field in different zones of the pupil to obtain on-axis constructive interference at a given distance. The conventional Soret zone plate (binary amplitude profile) is expanded to a polarization Soret zone plate with twice the focusing efficiency. Binary pixelated devices that approximate the sinusoidal transmission profile of a Gabor zone plate by spatial dithering are also investigated with amplitude and polarization modulation. Wavefront aberrations are corrected by modulation of the field in the pupil plane to prevent destructive interference in the focal plane of an ideal focusing element. Polarization modulation improves the efficiency obtained by amplitude-only modulation, with a gain that depends on the aberration. Experimental results obtained with Cr-on-glass devices for amplitude modulation and liquid crystal devices operating in the Mauguin condition for polarization modulation are in very good agreement with simulations.

  11. Simulation of Terahertz Frequency Sources. Polar-Optical Phonon Enhancement of Harmonic Generation in Schottky Diodes

    National Research Council Canada - National Science Library

    Gelmont, Boris

    2002-01-01

    ... polar optical vibration frequency When a high frequency input signal is applied to a frequency multiplier device polar-optical phonons can enhance the non-linearities inherent in this device, enabling...

  12. Oxide materials for spintronic device applications

    Science.gov (United States)

    Prestgard, Megan Campbell

    Spintronic devices are currently being researched as next-generation alternatives to traditional electronics. Electronics, which utilize the charge-carrying capabilities of electrons to store information, are fundamentally limited not only by size constraints, but also by limits on current flow and degradation, due to electro-migration. Spintronics devices are able to overcome these limitations, as their information storage is in the spin of electrons, rather than their charge. By using spin rather than charge, these current-limiting shortcomings can be easily overcome. However, for spintronic devices to be fully implemented into the current technology industry, their capabilities must be improved. Spintronic device operation relies on the movement and manipulation of spin-polarized electrons, in which there are three main processes that must be optimized in order to maximize device efficiencies. These spin-related processes are: the injection of spin-polarized electrons, the transport and manipulation of these carriers, and the detection of spin-polarized currents. In order to enhance the rate of spin-polarized injection, research has been focused on the use of alternative methods to enhance injection beyond that of a simple ferromagnetic metal/semiconductor injector interface. These alternatives include the use of oxide-based tunnel barriers and the modification of semiconductors and insulators for their use as ferromagnetic injector materials. The transport of spin-polarized carriers is heavily reliant on the optimization of materials' properties in order to enhance the carrier mobility and to quench spin-orbit coupling (SOC). However, a certain degree of SOC is necessary in order to allow for the electric-field, gate-controlled manipulation of spin currents. Spin detection can be performed via both optical and electrical techniques. Using electrical methods relies on the conversion between spin and charge currents via SOC and is often the preferred method for

  13. Prototyping of concurrent control systems implemented in FPGA devices

    CERN Document Server

    Wiśniewski, Remigiusz

    2017-01-01

    This book focuses on prototyping aspects of concurrent control systems and their further implementation and partial reconfiguration in programmable devices. Further, it lays out a full prototyping flow for concurrent control systems. Based on a given primary specification, a system is described with an interpreted Petri net, which naturally reflects the concurrent and sequential relationships of the design. The book shows that, apart from the traditional option of static configuration of the entire system, the latest programmable devices (especially FPGAs) offer far more sophistication. Partial reconfiguration allows selected parts of the system to be replaced without having to reprogram the entire structure of the device. Approaches to dynamic and static partial reconfiguration of concurrent control systems are presented and described in detail.< The theoretical work is illustrated by examples drawn from various applications, with a milling machine and a traffic-light controller highlighted as representat...

  14. Norms concerning the programmable automatic control devices

    International Nuclear Information System (INIS)

    Fourmentraux, G.

    1995-01-01

    This presentation is a report of the studies carried out by the Work Group on Functioning Safety of Programmable Automatic Control Devices and by the Group for Prevention Studies (GEP) from the CEA. The objective of these groups is to evaluate the methods which could be used to estimate the functioning safety of control and instrumentation systems involved in the Important Elements for Safety (EIS) of the Basic Nuclear Installations (INB) of the CEA, and also to carry out a qualification of automatic control devices. Norms, protocols and tools for the evaluation are presented. The problem comprises two aspects: the evaluation of fault avoidance techniques and the evaluation of fault control techniques used during the conceiving. For the fault avoidance techniques, the quality assurance organization, the environment tests, and the software quality plans are considered. For the fault control techniques, the different available tools and fault injection models are analysed. The results of an analysis carried out with the DEF.I tool from the National Institute for Research and Safety (INRS) are reported. (J.S.). 23 refs

  15. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides.

    Science.gov (United States)

    Wang, Ziming; Zhao, Xin; Xu, Xu; Wu, Lijie; Su, Rui; Zhao, Yajing; Jiang, Chengfei; Zhang, Hanqi; Ma, Qiang; Lu, Chunmei; Dong, Deming

    2013-01-14

    A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction (μ-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave μ-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in μ-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave μ-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60°C for 10 min. The extracts obtained by MAE-μ-SPE were directly analyzed by GC-MS without any clean-up process. The recoveries were in the range of 93.5-104.6%, and the relative standard deviations were lower than 8.7%. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Arbitrary Control of Polarization and Intensity Profiles of Diffraction-Attenuation-Resistant Beams along the Propagation Direction

    Science.gov (United States)

    Corato-Zanarella, Mateus; Dorrah, Ahmed H.; Zamboni-Rached, Michel; Mojahedi, Mo

    2018-02-01

    We report on the theory and experimental generation of a class of diffraction-attenuation-resistant beams with state of polarization (SOP) and intensity that can be controlled on demand along the propagation direction. This control is achieved by a suitable superposition of Bessel beams, whose parameters are systematically chosen based on closed-form analytic expressions provided by the frozen waves method. Using an amplitude-only spatial light modulator, we experimentally demonstrate three scenarios. In the first, the SOP of a horizontally polarized beam evolves to radial polarization and is then changed to vertical polarization, with the beam intensity held constant. In the second, we simultaneously control the SOP and the longitudinal intensity profile, which is chosen such that the beam's central ring can be switched off over predefined space regions, thus generating multiple foci with different SOPs and at different intensity levels along the propagation. Finally, the ability to control the SOP while overcoming attenuation inside lossy fluids is shown experimentally. We envision our proposed method to be of great interest for many applications, such as optical tweezers, atom guiding, material processing, microscopy, and optical communications.

  17. A polarizing neutron periscope for neutron imaging

    International Nuclear Information System (INIS)

    Schulz, Michael; Boeni, Peter; Calzada, Elbio; Muehlbauer, Martin; Neubauer, Andreas; Schillinger, Burkhard

    2009-01-01

    Optical neutron polarizers like guides or benders destroy the collimation of a neutron beam due to multiple reflections or scattering. This makes them unsuitable for their use in polarized neutron radiography, because the beam collimation is essential to obtain high spatial resolution. We have developed a neutron polarizer based on the principle of an optical periscope with a zigzag double reflection on two parallel high-m supermirror polarizers. If the supermirrors are perfectly parallel and flat, the beam collimation is left unchanged by such a device. A first proof of concept version of this type of polarizer was built and tested. We expect to achieve a beam polarization of up to 99% with an improved version yet to be built.

  18. Plasma Equilibrium Control in Nuclear Fusion Devices 2. Plasma Control in Magnetic Confinement Devices 2.1 Plasma Control in Tokamaks

    Science.gov (United States)

    Fukuda, Takeshi

    The plasma control technique for use in large tokamak devices has made great developmental strides in the last decade, concomitantly with progress in the understanding of tokamak physics and in part facilitated by the substantial advancement in the computing environment. Equilibrium control procedures have thereby been established, and it has been pervasively recognized in recent years that the real-time feedback control of physical quantities is indispensable for the improvement and sustainment of plasma performance in a quasi-steady-state. Further development is presently undertaken to realize the “advanced plasma control” concept, where integrated fusion performance is achieved by the simultaneous feedback control of multiple physical quantities, combined with equilibrium control.

  19. Digital Control of External Devices through the Parallel Port of a ...

    African Journals Online (AJOL)

    Digital Control of External Devices through the Parallel Port of a Computer Using Visual Basic. ... Nigerian Journal of Technology ... Keywords: device controller, digital switching, digital interfacing, visual basic, computer parallel port ...

  20. Bidirectional Telemetry Controller for Neuroprosthetic Devices

    Science.gov (United States)

    Sharma, Vishnu; McCreery, Douglas B.; Han, Martin; Pikov, Victor

    2010-01-01

    We present versatile multifunctional programmable controller with bidirectional data telemetry, implemented using existing commercial microchips and standard Bluetooth protocol, which adds convenience, reliability, and ease-of-use to neuroprosthetic devices. Controller, weighing 190 g, is placed on animal's back and provides bidirectional sustained telemetry rate of 500 kb/s, allowing real-time control of stimulation parameters and viewing of acquired data. In continuously-active state, controller consumes ∼420 mW and operates without recharge for 8 h. It features independent 16-channel current-controlled stimulation, allowing current steering; customizable stimulus current waveforms; recording of stimulus voltage waveforms and evoked neuronal responses with stimulus artifact blanking circuitry. Flexibility, scalability, cost-efficiency, and a user-friendly computer interface of this device allow use in animal testing for variety of neuroprosthetic applications. Initial testing of the controller has been done in a feline model of brainstem auditory prosthesis. In this model, the electrical stimulation is applied to the array of microelectrodes implanted in the ventral cochlear nucleus, while the evoked neuronal activity was recorded with the electrode implanted in the contralateral inferior colliculus. Stimulus voltage waveforms to monitor the access impedance of the electrodes were acquired at the rate of 312 kilosamples/s. Evoked neuronal activity in the inferior colliculus was recorded after the blanking (transient silencing) of the recording amplifier during the stimulus pulse, allowing the detection of neuronal responses within 100 μs after the end of the stimulus pulse applied in the cochlear nucleus. PMID:19933010

  1. Bidirectional telemetry controller for neuroprosthetic devices.

    Science.gov (United States)

    Sharma, Vishnu; McCreery, Douglas B; Han, Martin; Pikov, Victor

    2010-02-01

    We present versatile multifunctional programmable controller with bidirectional data telemetry, implemented using existing commercial microchips and standard Bluetooth protocol, which adds convenience, reliability, and ease-of-use to neuroprosthetic devices. Controller, weighing 190 g, is placed on animal's back and provides bidirectional sustained telemetry rate of 500 kb/s , allowing real-time control of stimulation parameters and viewing of acquired data. In continuously-active state, controller consumes approximately 420 mW and operates without recharge for 8 h . It features independent 16-channel current-controlled stimulation, allowing current steering; customizable stimulus current waveforms; recording of stimulus voltage waveforms and evoked neuronal responses with stimulus artifact blanking circuitry. Flexibility, scalability, cost-efficiency, and a user-friendly computer interface of this device allow use in animal testing for variety of neuroprosthetic applications. Initial testing of the controller has been done in a feline model of brainstem auditory prosthesis. In this model, the electrical stimulation is applied to the array of microelectrodes implanted in the ventral cochlear nucleus, while the evoked neuronal activity was recorded with the electrode implanted in the contralateral inferior colliculus. Stimulus voltage waveforms to monitor the access impedance of the electrodes were acquired at the rate of 312 kilosamples/s. Evoked neuronal activity in the inferior colliculus was recorded after the blanking (transient silencing) of the recording amplifier during the stimulus pulse, allowing the detection of neuronal responses within 100 mus after the end of the stimulus pulse applied in the cochlear nucleus.

  2. Experimental and simulated control of lift using trailing edge devices

    Science.gov (United States)

    Cooperman, A.; Blaylock, M.; van Dam, C. P.

    2014-12-01

    Two active aerodynamic load control (AALC) devices coupled with a control algorithm are shown to decrease the change in lift force experienced by an airfoil during a change in freestream velocity. Microtabs are small (1% chord) surfaces deployed perpendicular to an airfoil, while microjets are pneumatic jets with flow perpendicular to the surface of the airfoil near the trailing edge. Both devices are capable of producing a rapid change in an airfoil's lift coefficient. A control algorithm for microtabs has been tested in a wind tunnel using a modified S819 airfoil, and a microjet control algorithm has been simulated for a NACA 0012 airfoil using OVERFLOW. In both cases, the AALC devices have shown the ability to mitigate the changes in lift during a gust.

  3. Control-rod scram device

    International Nuclear Information System (INIS)

    Matsui, Yoshiro; Saito, Koji.

    1986-01-01

    Purpose: To eliminate the requirement for the nitrogen gas system in a scram device and enable safety and reliable shutdown of a water-cooled reactor power plant. Constitution: A piston and a spring are contained within a hydraulic vessel, and the piston is driven by the energy stored in the spring so as to supply hydraulic water to control mechanisms. During usual reactor operation, a scram valve is closed and a high water pressure of about 130 kg/cm 2 is applied to the water filled in the vessel through a check valve. Upon occurrence of abnormal conditions and generation of scram signals, the scram valve is opened to supply the water filled in the vessel through the scram valve to the control rod drive mechanisms. When the water pressure in the vessel is decreased, since the piston is urged upwardly by the energy stored in the spring, the water filled in the vessel is intermitently supplied to the control rod drive mechanisms. Thus, control rods can be inserted into the nuclear reactor to shutdown the same. (Horiuchi, T.)

  4. Generation and detection of spin polarization in parallel coupled double quantum dots connected to four terminals

    International Nuclear Information System (INIS)

    An, Xing-Tao; Mu, Hui-Ying; Li, Yu-Xian; Liu, Jian-Jun

    2011-01-01

    A four-terminal parallel double quantum dots (QDs) device is proposed to generate and detect the spin polarization in QDs. It is found that the spin accumulation in QDs and the spin-polarized currents in the upper and down leads can be generated when a bias voltage is applied between the left and right leads. It is more interesting that the spin polarization in the QDs can be detected using the upper and down leads. Moreover, the direction and magnitude of the spin polarization in the QDs, and in the upper and down leads can be tuned by the energy levels of QDs and the bias. -- Highlights: → The spin polarization in the quantum dots can be generated and controlled. → The spin polarization in quantum dots can be detected by the nonferromagnetic leads. → The system our studied is a discrete level spin Hall system.

  5. Practical design control implementation for medical devices

    CERN Document Server

    Justiniano, Jose

    2003-01-01

    Bringing together the concepts of design control and reliability engineering, this book is a must for medical device manufacturers. It helps them meet the challenge of designing and developing products that meet or exceed customer expectations and also meet regulatory requirements. Part One covers motivation for design control and validation, design control requirements, process validation and design transfer, quality system for design control, and measuring design control program effectiveness. Part Two discusses risk analysis and FMEA, designing-in reliability, reliability and design verific

  6. Freely tunable broadband polarization rotator for terahertz waves.

    Science.gov (United States)

    Fan, Ren-Hao; Zhou, Yu; Ren, Xiao-Ping; Peng, Ru-Wen; Jiang, Shang-Chi; Xu, Di-Hu; Xiong, Xiang; Huang, Xian-Rong; Wang, Mu

    2015-02-18

    A freely tunable polarization rotator for broadband terahertz waves is demonstrated using a three-rotating-layer metallic grating structure, which can conveniently rotate the polarization of a linearly polarized terahertz wave to any desired direction with nearly perfect conversion efficiency. This low-cost, high-efficiency, and freely tunable device has potential applications as material analysis, wireless communication, and THz imaging. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Production of linear polarization by segmentation of helical undulator

    International Nuclear Information System (INIS)

    Tanaka, T.; Kitamura, H.

    2002-01-01

    A simple scheme to obtain linearly polarized radiation (LPR) with a segmented undulator is proposed. The undulator is composed of several segments each of which forms a helical undulator and has helicity opposite to those of adjacent segments. Due to coherent sum of radiation, the circularly polarized component is canceled out resulting in production of LPR without any higher harmonics. The radiation from the proposed device is investigated analytically, which shows that a high degree of linear polarization is obtained in spite of a finite beam emittance and angular acceptance of optics, if a sufficiently large number of segments and an adequate photon energy are chosen. Results of calculation to investigate practical performances of the proposed device are presented

  8. Polarization-dependent thin-film wire-grid reflectarray for terahertz waves

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Tiaoming [School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide, South Australia 5005 (Australia); School of Information Science and Engineering, Lanzhou University, Lanzhou 730000 (China); Upadhyay, Aditi; Bhaskaran, Madhu; Sriram, Sharath [Functional Materials and Microsystems Research Group, RMIT University, Melbourne, Victoria 3001 (Australia); Withayachumnankul, Withawat [School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide, South Australia 5005 (Australia); Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1-S9-3, Ookayama, Meguro-ku, Tokyo 152-8552 (Japan); Headland, Daniel; Abbott, Derek; Fumeaux, Christophe, E-mail: cfumeaux@eleceng.adelaide.edu.au [School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide, South Australia 5005 (Australia)

    2015-07-20

    A thin-film polarization-dependent reflectarray based on patterned metallic wire grids is realized at 1 THz. Unlike conventional reflectarrays with resonant elements and a solid metal ground, parallel narrow metal strips with uniform spacing are employed in this design to construct both the radiation elements and the ground plane. For each radiation element, a certain number of thin strips with an identical length are grouped to effectively form a patch resonator with equivalent performance. The ground plane is made of continuous metallic strips, similar to conventional wire-grid polarizers. The structure can deflect incident waves with the polarization parallel to the strips into a designed direction and transmit the orthogonal polarization component. Measured radiation patterns show reasonable deflection efficiency and high polarization discrimination. Utilizing this flexible device approach, similar reflectarray designs can be realized for conformal mounting onto surfaces of cylindrical or spherical devices for terahertz imaging and communications.

  9. Migrated Essure permanent birth control device: sonographic findings.

    Science.gov (United States)

    Khati, Nadia Juliet; Gorodenker, Joseph; Brindle, Kathleen Ann

    2014-05-01

    We report a case of a migrated Essure permanent birth control device. The correct diagnosis was made on conventional two-dimensional and three-dimensional pelvic sonography 7 years after placement of the device when the patient presented with persistent right-sided pain. The 3-month post placement hysterosalpingogram had shown an appropriately occluded right fallopian tube but had overlooked the abnormal position of the right Essure device, which was too proximal and extending slightly in the uterine cavity. Copyright © 2013 Wiley Periodicals, Inc.

  10. Self-collimating photonic crystal polarization beam splitter.

    Science.gov (United States)

    Zabelin, V; Dunbar, L A; Le Thomas, N; Houdré, R; Kotlyar, M V; O'Faolain, L; Krauss, T F

    2007-03-01

    We present theoretical and experimental results of a polarization splitter device that consists of a photonic crystal (PhC) slab, which exhibits a large reflection coefficient for TE and a high transmission coefficient for TM polarization. The slab is embedded in a PhC tile operating in the self-collimation mode. Embedding the polarization-discriminating slab in a PhC with identical lattice symmetry suppresses the in-plane diffraction losses at the PhC-non-PhC interface. The optimization of the PhC-non-PhC interface is thereby decoupled from the optimization of the polarizing function. Transmissions as high as 35% for TM- and 30% for TE-polarized light are reported.

  11. Simple apparatus for polarization sensing of analytes

    Science.gov (United States)

    Gryczynski, Zygmunt; Gryczynski, Ignacy; Lakowicz, Joseph R.

    2000-09-01

    We describe a simple device for fluorescence sensing based on an unexpansive light source, a dual photocell and a Watson bridge. The emission is detected from two fluorescent samples, one of which changes intensity in response to the analyte. The emission from these two samples is observed through two orthogonally oriented polarizers and an analyzer polarizer. The latter polarizer is rotated to yield equal intensities from both sides of the dual photocell, as determined by a zero voltage from the Watson bridge. Using this device, we are able to measure fluorescein concentration to an accuracy near 2% at 1 (mu) M fluorescein, and pH values accurate to +/- 0.02 pH units. We also use this approach with a UV hand lamp and a glucose-sensitive protein to measure glucose concentrations near 2 (mu) M to an accuracy of +/- 0.1 (mu) M. This approach requires only simple electronics, which can be battery powered. Additionally, the method is generic, and can be applied with any fluorescent sample that displays a change in intensity. One can imagine this approach being used to develop portable point-of-care clinical devices.

  12. Direct Probing of Polarization Charge at Nanoscale Level

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Owoong [Sungkyunkwan Univ., Suwon (Republic of Korea). School of Advanced Materials and Engineering; Seol, Daehee [Sungkyunkwan Univ., Suwon (Republic of Korea). School of Advanced Materials and Engineering; Lee, Dongkyu [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Han, Hee [Korea Research Inst. of Standards and Science (KRISS), Daejeon (South Korea); Lindfors-Vrejoiu, Ionela [Univ. of Cologne (Germany). Physics Inst.; Lee, Woo [Korea Research Inst. of Standards and Science (KRISS), Daejeon (South Korea); Jesse, Stephen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences; Lee, Ho Nyung [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Kalinin, Sergei V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences; Alexe, Marin [Univ. of Warwick, Coventry (United Kingdom). Dept. of Physics; Kim, Yunseok [Sungkyunkwan Univ., Suwon (Republic of Korea). School of Advanced Materials and Engineering

    2017-11-14

    Ferroelectric materials possess spontaneous polarization that can be used for multiple applications. Owing to a long-term development of reducing the sizes of devices, the preparation of ferroelectric materials and devices is entering the nanometer-scale regime. In order to evaluate the ferroelectricity, there is a need to investigate the polarization charge at the nanoscale. Nonetheless, it is generally accepted that the detection of polarization charges using a conventional conductive atomic force microscopy (CAFM) without a top electrode is not feasible because the nanometer-scale radius of an atomic force microscopy (AFM) tip yields a very low signal-to-noise ratio. But, the detection is unrelated to the radius of an AFM tip and, in fact, a matter of the switched area. In this work, the direct probing of the polarization charge at the nanoscale is demonstrated using the positive-up-negative-down method based on the conventional CAFM approach without additional corrections or circuits to reduce the parasitic capacitance. The polarization charge densities of 73.7 and 119.0 µC cm-2 are successfully probed in ferroelectric nanocapacitors and thin films, respectively. The results we obtained show the feasibility of the evaluation of polarization charge at the nanoscale and provide a new guideline for evaluating the ferroelectricity at the nanoscale.

  13. Polarization-coupled tunable resistive behavior in oxide ferroelectric heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Gruverman, Alexei [Univ. of Nebraska, Lincoln, NE (United States); Tsymbal, Evgeny Y. [Univ. of Nebraska, Lincoln, NE (United States); Eom, Chang-Beom [Univ. of Wisconsin, Madison, WI (United States)

    2017-05-03

    This research focuses on investigation of the physical mechanism of the electrically and mechanically tunable resistive behavior in oxide ferroelectric heterostructures with engineered interfaces realized via a strong coupling of ferroelectric polarization with tunneling electroresistance and metal-insulator (M-I) transitions. This report describes observation of electrically conductive domain walls in semiconducting ferroelectrics, voltage-free control of resistive switching and demonstration of a new mechanism of electrical control of 2D electron gas (2DEG) at oxide interfaces. The research goals are achieved by creating strong synergy between cutting-edge fabrication of epitaxial single-crystalline complex oxides, nanoscale electrical characterization by scanning probe microscopy and theoretical modeling of the observed phenomena. The concept of the ferroelectric devices with electrically and mechanically tunable nonvolatile resistance represents a new paradigm shift in realization of the next-generation of non-volatile memory devices and low-power logic switches.

  14. High-efficiency and multi-frequency polarization converters based on graphene metasurface with twisting double L-shaped unit structure array

    Science.gov (United States)

    Chen, Ming; Xiao, Xiaofei; Chang, Linzi; Wang, Congyun; Zhao, Deping

    2017-07-01

    In this work, a high-efficiency and tunable dual-frequency reflective polarization converter composed of graphene metasurface with twisting double L-shaped unit is firstly realized. Numerical results demonstrate that the device can convert a linearly polarized wave to its cross-polarized wave, and meantime it can also convert to a circularly polarized wave. Subsequently, one thickness of 500 nm SiO2 layer sandwiched by two graphene metasurfaces with similar pattern is stacked on the top of the two-layered structure, a four-frequency efficient reflective polarization converters is realized. Above all, those working frequencies can also be dynamically tuned within a large frequency range by adjusting the Fermi energy of the graphene, without reoptimizing and refabricating the nanostructures, which paves a novel way toward developing a controllable polarization converter for mid-infrared applications.

  15. Polarization control of intermediate state absorption in resonance-mediated multi-photon absorption process

    International Nuclear Information System (INIS)

    Xu, Shuwu; Yao, Yunhua; Jia, Tianqing; Ding, Jingxin; Zhang, Shian; Sun, Zhenrong; Huang, Yunxia

    2015-01-01

    We theoretically and experimentally demonstrate the control of the intermediate state absorption in an (n + m) resonance-mediated multi-photon absorption process by the polarization-modulated femtosecond laser pulse. An analytical solution of the intermediate state absorption in a resonance-mediated multi-photon absorption process is obtained based on the time-dependent perturbation theory. Our theoretical results show that the control efficiency of the intermediate state absorption by the polarization modulation is independent of the laser intensity when the transition from the intermediate state to the final state is coupled by the single-photon absorption, but will be affected by the laser intensity when this transition is coupled by the non-resonant multi-photon absorption. These theoretical results are experimentally confirmed via a two-photon fluorescence control in (2 + 1) resonance-mediated three-photon absorption of Coumarin 480 dye and a single-photon fluorescence control in (1 + 2) resonance-mediated three-photon absorption of IR 125 dye. (paper)

  16. Experimental and simulated control of lift using trailing edge devices

    International Nuclear Information System (INIS)

    Cooperman, A; Blaylock, M; Van Dam, C P

    2014-01-01

    Two active aerodynamic load control (AALC) devices coupled with a control algorithm are shown to decrease the change in lift force experienced by an airfoil during a change in freestream velocity. Microtabs are small (1% chord) surfaces deployed perpendicular to an airfoil, while microjets are pneumatic jets with flow perpendicular to the surface of the airfoil near the trailing edge. Both devices are capable of producing a rapid change in an airfoil's lift coefficient. A control algorithm for microtabs has been tested in a wind tunnel using a modified S819 airfoil, and a microjet control algorithm has been simulated for a NACA 0012 airfoil using OVERFLOW. In both cases, the AALC devices have shown the ability to mitigate the changes in lift during a gust

  17. EXOS research on master controllers for robotic devices

    Science.gov (United States)

    Marcus, Beth A.; An, Ben; Eberman, Brian

    1992-01-01

    Two projects are currently being conducted by EXOS under the Small Business Innovation Research (SBIR) program with NASA. One project will develop a force feedback device for controlling robot hands, the other will develop an elbow and shoulder exoskeleton which can be integrated with other EXOS devices to provide whole robot arm and hand control. Aspects covered are the project objectives, important research issues which have arisen during the developments, and interim results of the projects. The Phase 1 projects currently underway will result in hardware prototypes and identification of research issues required for complete system development and/or integration.

  18. Particle and impurity control in toroidal fusion devices

    International Nuclear Information System (INIS)

    Wootton, A.J.

    1986-01-01

    A review of working particle and impurity control techniques used in and proposed for magnetic fusion devices is presented. The requirements of both present-day machines and envisaged fusion reactors are considered. The various techniques which have been proposed are characterized by whether they affect sources, sinks, or fluxes; in many cases a particular method or device can appear in more than one category. Examples are drawn from published results. The solutions proposed for the large devices which will be operating during the next 5 years are discussed

  19. Polarity control and growth mode of InN on yttria-stabilized zirconia (111) surfaces

    International Nuclear Information System (INIS)

    Kobayashi, Atsushi; Okubo, Kana; Ohta, Jitsuo; Oshima, Masaharu; Fujioka, Hiroshi

    2012-01-01

    We have found that polarity of epitaxial InN layers has been controlled by choice of a capping material during high-temperature annealing of yttria-stabilized zirconia (YSZ) (111) substrates in air. Angle-resolved X-ray photoelectron spectroscopy has revealed that the amount of segregation of Y atoms to the YSZ surface depended on the capping material of the substrates. In-polar and N-polar InN have been reproducibly grown on Y-segregated and Y-segregation-free YSZ surfaces, respectively. We have also found that the growth of the first monolayer (ML) of N-polar InN proceeds in a step-flow mode which then switches to layer-by-layer mode after the coverage by 1-ML-thick InN. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Consumer-grade EEG devices: are they usable for control tasks?

    Directory of Open Access Journals (Sweden)

    Rytis Maskeliunas

    2016-03-01

    Full Text Available We present the evaluation of two well-known, low-cost consumer-grade EEG devices: the Emotiv EPOC and the Neurosky MindWave. Problems with using the consumer-grade EEG devices (BCI illiteracy, poor technical characteristics, and adverse EEG artefacts are discussed. The experimental evaluation of the devices, performed with 10 subjects asked to perform concentration/relaxation and blinking recognition tasks, is given. The results of statistical analysis show that both devices exhibit high variability and non-normality of attention and meditation data, which makes each of them difficult to use as an input to control tasks. BCI illiteracy may be a significant problem, as well as setting up of the proper environment of the experiment. The results of blinking recognition show that using the Neurosky device means recognition accuracy is less than 50%, while the Emotiv device has achieved a recognition accuracy of more than 75%; for tasks that require concentration and relaxation of subjects, the Emotiv EPOC device has performed better (as measured by the recognition accuracy by ∼9%. Therefore, the Emotiv EPOC device may be more suitable for control tasks using the attention/meditation level or eye blinking than the Neurosky MindWave device.

  1. An omnipotent Li-ion battery charger with multimode control and polarity reversible techniques

    Science.gov (United States)

    Chen, Jiann-Jong; Ku, Yi-Tsen; Yang, Hong-Yi; Hwang, Yuh-Shyan; Yu, Cheng-Chieh

    2016-07-01

    The omnipotent Li-ion battery charger with multimode control and polarity reversible techniques is presented in this article. The proposed chip is fabricated with TSMC 0.35μm 2P4M complementary metal-oxide- semiconductor processes, and the chip area including pads is 1.5 × 1.5 mm2. The structure of the omnipotent charger combines three charging modes and polarity reversible techniques, which adapt to any Li-ion batteries. The three reversible Li-ion battery charging modes, including trickle-current charging, large-current charging and constant-voltage charging, can charge in matching polarities or opposite polarities. The proposed circuit has a maximum charging current of 300 mA and the input voltage of the proposed circuit is set to 4.5 V. The maximum efficiency of the proposed charger is about 91% and its average efficiency is 74.8%. The omnipotent charger can precisely provide the charging current to the battery.

  2. Femtosecond laser ablation of transparent microphotonic devices and computer-generated holograms.

    Science.gov (United States)

    Alqurashi, Tawfiq; Montelongo, Yunuen; Penchev, Pavel; Yetisen, Ali K; Dimov, Stefan; Butt, Haider

    2017-09-21

    Femtosecond laser ablation allows direct patterning of engineering materials in industrial settings without requiring multistage processes such as photolithography or electron beam lithography. However, femtosecond lasers have not been widely used to construct volumetric microphotonic devices and holograms with high reliability and cost efficiency. Here, a direct femtosecond laser writing process is developed to rapidly produce transmission 1D/2D gratings, Fresnel Zone Plate lenses, and computer-generated holograms. The optical properties including light transmission, angle-dependent resolution, and light polarization effects for the microphotonic devices have been characterized. Varying the depth of the microgratings from 400 nm to 1.5 μm allowed the control over their transmission intensity profile. The optical properties of the 1D/2D gratings were validated through a geometrical theory of diffraction model involving 2D phase modulation. The produced Fresnel lenses had transmission efficiency of ∼60% at normal incidence and they preserved the polarization of incident light. The computer-generated holograms had an average transmission efficiency of 35% over the visible spectrum. These microphotonic devices had wettability resistance of contact angle ranging from 44° to 125°. These devices can be used in a variety of applications including wavelength-selective filters, dynamic displays, fiber optics, and biomedical devices.

  3. AmbiGaze : direct control of ambient devices by gaze

    OpenAIRE

    Velloso, Eduardo; Wirth, Markus; Weichel, Christian; Abreu Esteves, Augusto Emanuel; Gellersen, Hans-Werner Georg

    2016-01-01

    Eye tracking offers many opportunities for direct device control in smart environments, but issues such as the need for calibration and the Midas touch problem make it impractical. In this paper, we propose AmbiGaze, a smart environment that employs the animation of targets to provide users with direct control of devices by gaze only through smooth pursuit tracking. We propose a design space of means of exposing functionality through movement and illustrate the concept through four prototypes...

  4. Characterization of Partially Polarized Light Fields

    CERN Document Server

    Martínez-Herrero, Rosario; Piquero, Gemma

    2009-01-01

    Polarization involves the vectorial nature of light fields. In current applications of optical science, the electromagnetic description of light with its vector features has been shown to be essential: In practice, optical radiation also exhibits randomness and spatial non-uniformity of the polarization state. Moreover, propagation through photonic devices can alter the correlation properties of the light field, resulting in changes in polarization. All these vectorial properties have been gaining importance in recent years, and they are attracting increasing attention in the literature. This is the framework and the scope of the present book, which includes the authors’ own contributions to these issues.

  5. Broadband asymmetric transmission of linearly polarized electromagnetic waves based on chiral metamaterial

    Science.gov (United States)

    Stephen, Lincy; Yogesh, N.; Subramanian, V.

    2018-01-01

    The giant optical activity of chiral metamaterials (CMMs) holds great potential for tailoring the polarization state of an electromagnetic (EM) wave. In controlling the polarization state, the aspect of asymmetric transmission (AT), where a medium allows the EM radiation to pass through in one direction while restricting it in the opposite direction, adds additional degrees of freedom such as one-way channelling functionality. In this work, a CMM formed by a pair of mutually twisted slanted complementary metal strips is realized for broadband AT accompanied with cross-polarization (CP) conversion for linearly polarized EM waves. Numerically, the proposed ultra-thin (˜λ/42) CMM shows broadband AT from 8.58 GHz to 9.73 GHz (bandwidth of 1.15 GHz) accompanied with CP transmission magnitude greater than 0.9. The transmission and reflection spectra reveal the origin of the asymmetric transmission as the direction sensitive cross polarization conversion and anisotropic electric coupling occurring in the structure which is then elaborated with the surface current analysis and electric field distribution within the structure. An experiment is carried out to verify the broadband AT based CP conversion of the proposed CMM at microwave frequencies, and a reliable agreement between numerical and experimental results is obtained. Being ultra-thin, the reported broadband AT based CP conversion of the proposed CMM is useful for controlling radiation patterns in non-reciprocal EM devices and communication networks.

  6. The selective digital integrator: A new device for modulated polarization spectroscopy

    Science.gov (United States)

    Vrancic, Aljosa

    1998-12-01

    A new device, a selective digital integrator (SDI), for the acquisition of modulated polarization spectroscopy (MPS) signals is described. Special attention is given to the accurate measurement of very small (AC component of interest 50 kHz) signals at or below noise levels. Various data acquisition methods and problems associated with the collection of modulated signals are discussed. The SDI solves most of these problems and has the following advantages: it provides the average-time resolved profile of a modulated signal; it eliminates errors if the modulation is not sinusoidal; it enables separate measurements of the various phases of the signal modulation cycle; it permits simultaneous measurement of absorption, circular dichroism (CD) and linear dichroism (LD) spectra; it facilitates 3-D absorbance measurements; it has a wide gain-switching-free dynamic range (10 orders of magnitude or more); it offers a constant S/N ratio mode of operation; it eliminates the need for photomultiplier voltage feedback, and it has faster scanning speeds. The time-resolution, selectivity, wide dynamic range, and low-overhead on-the-fly data processing are useful for other modulated spectroscopy (MS) and non-MS experiments such as pulse height distribution and time-resolved pulse counting measurements. The advantages of the MPS-SDI method are tested on the first Rydberg electronic transitions of (+)-3- methylcyclopentanone. The experimental results validate the predicted SDI capabilities. However, they also point to two difficulties that had not been noted previously: the presence of LD in a gaseous sample and a pressure- dependence of the relative peak heights of the CD spectrum. Models for these anomalies are proposed. The presence of the oscillatory LD (but not an LD background) is explained with a sample cell model based on the observed polarization-dependent time-resolved profiles of transmitted light intensity. To obtain expressions for these intensities, a theoretical

  7. Mechanisms of Cell Polarity-Controlled Epithelial Homeostasis and Immunity in the Intestine

    NARCIS (Netherlands)

    Klunder, Leon J.; Faber, Klaas Nico; Dijkstra, Gerard; van IJzendoorn, Sven C. D.

    Intestinal epithelial cell polarity is instrumental to maintain epithelial homeostasis and balance communications between the gut lumen and bodily tissue, thereby controlling the defense against gastrointestinal pathogens and maintenance of immune tolerance to commensal bacteria. In this review, we

  8. Nuclear reactor power control device

    International Nuclear Information System (INIS)

    Koshi, Yuji; Sakata, Akira; Karatsu, Hiroyuki.

    1987-01-01

    Purpose: To control abrupt changes in neutron fluxes by feeding back a correction signal obtained from a deviation between neutron fluxes and heat fluxes for changing the reactor core flow rate to a recycling flow rate control system upon abrupt power change of a nuclear reactor. Constitution: In addition to important systems, that is, a reactor pressure control system and a recycling control system in the power control device of a BWR type power plant, a control circuit for feeding back a deviation between neutron fluxes and heat fluxes to a recycling flow rate control system is disposed. In the suppression circuit, a deviation signal is prepared in an adder from neutron flux and heat flux signals obtained through a primary delay filter. The deviation signal is passed through a dead band and an advance/delay filter into a correction signal, which is adapted to be fed back to the recycling flow rate control system. As a result, the reactor power control can be conducted smoothly and it is possible to effectively suppress the abrupt change or over shoot of the neutron fluxes and abrupt power change. (Kamimura, M.)

  9. Re-Active Passive devices for control of noise transmission through a panel

    Science.gov (United States)

    Carneal, James P.; Giovanardi, Marco; Fuller, Chris R.; Palumbo, Dan

    2008-01-01

    Re-Active Passive devices have been developed to control low-frequency (transmission through a panel. These devices use a combination of active, re-active, and passive technologies packaged into a single unit to control a broad frequency range utilizing the strength of each technology over its best suited frequency range. The Re-Active Passive device uses passive constrained layer damping to cover relatively high-frequency range (>150 Hz), reactive distributed vibration absorber to cover the medium-frequency range (50-200 Hz), and active control for controlling low frequencies (transmission through a panel mounted in the Transmission Loss Test Facility at Virginia Tech. Experimental results are presented for the bare panel, and combinations of passive treatment, reactive treatment, and active control. Results indicate that three Re-Active Passive devices were able to increase the overall broadband (15-1000 Hz) transmission loss by 9.4 dB. These three devices added a total of 285 g to the panel mass of 6.0 kg, or approximately 5%, not including control electronics.

  10. Application of Zeeman spatial beam-splitting in polarized neutron reflectometry

    OpenAIRE

    Kozhevnikov, S. V.; Ignatovich, V. K.; Radu, F.

    2017-01-01

    Neutron Zeeman spatial beam-splitting is considered at reflection from magnetically noncollinear films. Two applications of Zeeman beam-splitting phenomenon in polarized neutron reflectometry are discussed. One is the construction of polarizing devices with high polarizing efficiency. Another one is the investigations of magnetically noncollinear films with low spin-flip probability. Experimental results are presented for illustration.

  11. Inverse design engineering of all-silicon polarization beam splitters

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Sigmund, Ole

    2016-01-01

    Utilizing the inverse design engineering method of topology optimization, we have realized high-performing all-silicon ultra-compact polarization beam splitters. We show that the device footprint of the polarization beam splitter can be as compact as similar to 2 µm2 while performing experimentally...

  12. Reactor water level control device

    International Nuclear Information System (INIS)

    Utagawa, Kazuyuki.

    1993-01-01

    A device of the present invention can effectively control fluctuation of a reactor water level upon power change by reactor core flow rate control operation. That is, (1) a feedback control section calculates a feedwater flow rate control amount based on a deviation between a set value of a reactor water level and a reactor water level signal. (2) a feed forward control section forecasts steam flow rate change based on a reactor core flow rate signal or a signal determining the reactor core flow rate, to calculate a feedwater flow rate control amount which off sets the steam flow rate change. Then, the sum of the output signal from the process (1) and the output signal from the process (2) is determined as a final feedwater flow rate control signal. With such procedures, it is possible to forecast the steam flow rate change accompanying the reactor core flow rate control operation, thereby enabling to conduct preceding feedwater flow rate control operation which off sets the reactor water level fluctuation based on the steam flow rate change. Further, a reactor water level deviated from the forecast can be controlled by feedback control. Accordingly, reactor water level fluctuation upon power exchange due to the reactor core flow rate control operation can rapidly be suppressed. (I.S.)

  13. Electronic adherence monitoring device performance and patient acceptability: a randomized control trial.

    Science.gov (United States)

    Chan, Amy Hai Yan; Stewart, Alistair William; Harrison, Jeff; Black, Peter Nigel; Mitchell, Edwin Arthur; Foster, Juliet Michelle

    2017-05-01

    To investigate the performance and patient acceptability of an inhaler electronic monitoring device in a real-world childhood asthma population. Children 6 to 15 years presenting with asthma to the hospital emergency department and prescribed inhaled corticosteroids were included. Participants were randomized to receive a device with reminder features enabled or disabled for use with their preventer. Device quality control tests were conducted. Questionnaires on device acceptability, utility and ergonomics were completed at six months. A total of 1306 quality control tests were conducted; 84% passed pre-issue and 87% return testing. The most common failure reason was actuation under-recording. Acceptability scores were high, with higher scores in the reminder than non-reminder group (median, 5 th -95 th percentile: 4.1, 3.1-5.0 versus 3.7, 2.3-4.8; p 90%) rated the device easy to use. Feedback was positive across five themes: device acceptability, ringtone acceptability, suggestions for improvement, effect on medication use, and effect on asthma control. This study investigates electronic monitoring device performance and acceptability in children using quantitative and qualitative measures. Results indicate satisfactory reliability, although failure rates of 13-16% indicate the importance of quality control. Favorable acceptability ratings support the use of these devices in children.

  14. Method and device for controlling nuclear reactor power

    International Nuclear Information System (INIS)

    Takigawa, Yukio; Ebata, Shigeo.

    1988-01-01

    Purpose: To detect and suppress the special power oscillations in the reactor core. Method: Four pairs of LPRM detectors, each pair comprising two detectors are disposed at an identical axial direction of the reactor core and situated at substantially insymmetrical positions at least in longitudinal, vertical and orthogonal directions with respect to the center of te reactor core and LPRM signals from them are inputted into a device for judging special power oscillations. In this case, a standardized mutual relation function is determined on every pair for the respective LPRM signals. Generation of special power oscillations in the reactor core is judged when it is detected that peaks appearing at least in one of the function forms for each pair are negative and have absolute values exceeding a predetermined value and that time of peak is within a predetermined time. The judged signal is inputted to a selected control rod insertion device. The selected control rod insertion device, upon preceiving the signal, inserts selected control rods into the reactor core to suppress the special power oscillations. Accordingly, it is possible to improve the fuel integrity. (Horiuchi, T.)

  15. Independent control of the vortex chirality and polarity in a pair of magnetic nanodots

    Energy Technology Data Exchange (ETDEWEB)

    Li, Junqin; Wang, Yong, E-mail: wangyong@sinap.ac.cn; Cao, Jiefeng; Meng, Xiangyu; Zhu, Fangyuan; Wu, Yanqing; Tai, Renzhong

    2017-08-01

    Independent control of the vortex chirality and polarity is realized by changing the in-plane magnetic field direction in nanodot pair through Object Oriented Micromagnetic Framework (OOMMF) simulation. The two magnetic circles are close to each other and have magnetic interaction. The two circles always have the same polarity and opposite chirality at every remanent state. There are totally four predictable magnetic states in the nanodot pair which can be obtained in the remanent state relaxed from the saturation state along all possible directions. An explanation on the formation of vortex states is given by vortex dynamics. The vortex states are stable in large out-of-plane magnetic field which is in a direction opposite to the vortex polarity. The geometry of the nanodot pair gives a way to easily realize a vortex state with specific polarity and chirality.

  16. Note: 4-bounce neutron polarizer for reflectometry applications

    Science.gov (United States)

    Nagy, B.; Merkel, D. G.; Jakab, L.; Füzi, J.; Veres, T.; Bottyán, L.

    2018-05-01

    A neutron polarizer using four successive reflections on m = 2.5 supermirrors was built and installed at the GINA neutron reflectometer at the Budapest Neutron Centre. This simple setup exhibits 99.6% polarizing efficiency with 80% transmitted intensity of the selected polarization state. Due to the geometry, the higher harmonics in the incident beam are filtered out, while the optical axis of the beam remains intact for easy mounting and dismounting the device in an existing experimental setup.

  17. Unconventional device concepts for polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Veenstra, S.C.; Slooff, L.H.; Verhees, W.J.H.; Cobussen-Pool, E.M.; Lenzmann, F.O.; Kroon, J.M. [ECN Solar Energy, Petten (Netherlands); Sessolo, M.; Bolink, H.J. [Instituto de Ciencia Molecular, Universidad de Valencia, Valencia (Spain)

    2009-09-15

    The inclusion of metal-oxide layers in polymer solar cells enables the fabrication of a series of unconventional device architectures. These devices include: semi-transparent polymer solar cells, devices with inverted polarity, as well as devices with air stable electrodes. A proof-of-principle of these devices is presented. The anticipated benefits of these novel device structures over conventional polymer solar cells are discussed.

  18. Circular polarization control for the European XFEL in the soft X-ray regime

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2011-06-15

    The possibility of producing X-ray radiation with high degree of circular polarization is an important asset at XFEL facilities. Polarization control is most important in the soft X-ray region.However, the baseline of the European XFEL, including the soft X-ray SASE3 line, foresees planar undulators only, yielding linearly-polarized radiation. It is clear that the lowest-risk strategy for implementing polarization control at SASE3 involves adding an APPLE II-type undulator at the end of the planar undulator, in order to exploit the micro bunching from the baseline FEL. Detailed experience is available in synchrotron radiation laboratories concerning the manufacturing of 5 m-long APPLE II undulators. However, the choice of a short helical radiator leads to the problem of background suppression. The driving idea of our proposal is that the background radiation can be suppressed by spatial filtering. This operation can be performed by inserting slits behind the APPLE II radiator, where the linearly-polarized radiation spot size is about 30 times larger than the radiation spot size from the helical radiator. The last 7 cells of the SASE3 undulator are left with an open gap in order to provide a total 42 m drift section for electron beam and radiation. Due to the presence of the drift the linearly-polarized radiation spot size increases, and the linearly polarized background radiation can be suppressed by the slits. At the same time, the microbunch structure is easily preserved, so that intense (100 GW) coherent radiation is emitted in the helical radiator. We propose a filtering setup consisting of a pair of water cooled slits for X-ray beam filtering and of a 5 m-long magnetic chicane, which creates an offset for slit installation immediately behind the helical radiator. Electrons and X-rays are separated before the slits by the magnetic chicane, so that the electron beam can pass by the filtering setup without perturbations. Based on start-to-end simulations we

  19. Circular polarization control for the European XFEL in the soft X-ray regime

    International Nuclear Information System (INIS)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2011-06-01

    The possibility of producing X-ray radiation with high degree of circular polarization is an important asset at XFEL facilities. Polarization control is most important in the soft X-ray region.However, the baseline of the European XFEL, including the soft X-ray SASE3 line, foresees planar undulators only, yielding linearly-polarized radiation. It is clear that the lowest-risk strategy for implementing polarization control at SASE3 involves adding an APPLE II-type undulator at the end of the planar undulator, in order to exploit the micro bunching from the baseline FEL. Detailed experience is available in synchrotron radiation laboratories concerning the manufacturing of 5 m-long APPLE II undulators. However, the choice of a short helical radiator leads to the problem of background suppression. The driving idea of our proposal is that the background radiation can be suppressed by spatial filtering. This operation can be performed by inserting slits behind the APPLE II radiator, where the linearly-polarized radiation spot size is about 30 times larger than the radiation spot size from the helical radiator. The last 7 cells of the SASE3 undulator are left with an open gap in order to provide a total 42 m drift section for electron beam and radiation. Due to the presence of the drift the linearly-polarized radiation spot size increases, and the linearly polarized background radiation can be suppressed by the slits. At the same time, the microbunch structure is easily preserved, so that intense (100 GW) coherent radiation is emitted in the helical radiator. We propose a filtering setup consisting of a pair of water cooled slits for X-ray beam filtering and of a 5 m-long magnetic chicane, which creates an offset for slit installation immediately behind the helical radiator. Electrons and X-rays are separated before the slits by the magnetic chicane, so that the electron beam can pass by the filtering setup without perturbations. Based on start-to-end simulations we

  20. Photon management of GaN-based optoelectronic devices via nanoscaled phenomena

    KAUST Repository

    Tsai, Yu-Lin

    2016-09-06

    Photon management is essential in improving the performances of optoelectronic devices including light emitting diodes, solar cells and photo detectors. Beyond the advances in material growth and device structure design, photon management via nanoscaled phenomena have also been demonstrated as a promising way for further modifying/improving the device performance. The accomplishments achieved by photon management via nanoscaled phenomena include strain-induced polarization field management, crystal quality improvement, light extraction/harvesting enhancement, radiation pattern control, and spectrum management. In this review, we summarize recent development, challenges and underlying physics of photon management in GaN-based light emitting diodes and solar cells. (C) 2016 Elsevier Ltd. All rights reserved.

  1. Control rod driving hydraulic device

    International Nuclear Information System (INIS)

    Sugano, Hiroshi.

    1993-01-01

    In a control rod driving hydraulic device for an improved BWR type reactor, a bypass pipeline is disposed being branched from a scram pipeline, and a control orifice and a throttle valve are interposed to the bypass pipeline for restricting pressure. Upon occurrence of scram, about 1/2 of water quantity flowing from an accumulator of a hydraulic control unit to the lower surface of a piston of control rod drives by way of a scram pipeline is controlled by the restricting orifice and the throttle valve, by which the water is discharged to a pump suction pipeline or other pipelines by way of the bypass pipeline. With such procedures, a function capable of simultaneously conducting scram for two control rod drives can be attained by one hydraulic control unit. Further, an excessive peak pressure generated by a water hammer phenomenon in the scram pipeline or the control rod drives upon occurrence of scram can be reduced. Deformation and failure due to the excessive peak pressure can be prevented, as well as vibrations and degradation of performance of relevant portions can be prevented. (N.H.)

  2. Control of periodic surface structures on silicon by combined temporal and polarization shaping of femtosecond laser pulses

    Science.gov (United States)

    Fraggelakis, F.; Stratakis, E.; Loukakos, P. A.

    2018-06-01

    We demonstrate the capability to exercise advanced control on the laser-induced periodic surface structures (LIPSS) on silicon by combining the effect of temporal shaping, via tuning the interpulse temporal delay between double femtosecond laser pulses, along with the independent manipulation of the polarization state of each of the individual pulses. For this, cross-polarized (CP) as well as counter-rotating (CR) double circularly polarized pulses have been utilized. The pulse duration was 40 fs and the central wavelength of 790 nm. The linearly polarized double pulses are generated by a modified Michelson interferometer allowing the temporal delay between the pulses to vary from Δτ = -80 ps to Δτ = +80 ps with an accuracy of 0.2 fs. We show the significance of fluence balance between the two pulse components and its interplay with the interpulse delay and with the order of arrival of the individually polarized pulse components of the double pulse sequence on the final surface morphology. For the case of CR pulses we found that when the pulses are temporally well separated the surface morphology attains no axial symmetry. But strikingly, when the two CP pulses temporally overlap, we demonstrate, for the first time in our knowledge, the detrimental effect that the phase delay has on the ripple orientation. Our results provide new insight showing that temporal pulse shaping in combination with polarization control gives a powerful tool for drastically controlling the surface nanostructure morphology.

  3. Channel Access and Power Control for Mobile Crowdsourcing in Device-to-Device Underlaid Cellular Networks

    Directory of Open Access Journals (Sweden)

    Yue Ma

    2018-01-01

    Full Text Available With the access of a myriad of smart handheld devices in cellular networks, mobile crowdsourcing becomes increasingly popular, which can leverage omnipresent mobile devices to promote the complicated crowdsourcing tasks. Device-to-device (D2D communication is highly desired in mobile crowdsourcing when cellular communications are costly. The D2D cellular network is more preferable for mobile crowdsourcing than conventional cellular network. Therefore, this paper addresses the channel access and power control problem in the D2D underlaid cellular networks. We propose a novel semidistributed network-assisted power and a channel access control scheme for D2D user equipment (DUE pieces. It can control the interference from DUE pieces to the cellular user accurately and has low information feedback overhead. For the proposed scheme, the stochastic geometry tool is employed and analytic expressions are derived for the coverage probabilities of both the cellular link and D2D links. We analyze the impact of key system parameters on the proposed scheme. The Pareto optimal access threshold maximizing the total area spectral efficiency is obtained. Unlike the existing works, the performances of the cellular link and D2D links are both considered. Simulation results show that the proposed method can improve the total area spectral efficiency significantly compared to existing schemes.

  4. Optically controlled polarizer using a ladder transition for high speed Stokesmetric Imaging and Quantum Zeno Effect based optical logic.

    Science.gov (United States)

    Krishnamurthy, Subramanian; Wang, Y; Tu, Y; Tseng, S; Shahriar, M S

    2013-10-21

    We demonstrate an optically controlled polarizer at ~1323 nm using a ladder transition in a Rb vapor cell. The lower leg of the 5S(1/2),F = 1->5P(1/2),F = 1,2->6S(1/2),F = 1,2 transitions is excited by a Ti:Sapphire laser locked to a saturated absorption signal, representing the control beam. A tunable fiber laser at ~1323 nm is used to excite the upper leg of the transitions, representing the signal beam. When the control beam is linearly polarized, it produces an excitation of the intermediate level with a particular orientation of the angular momentum. Under ideal conditions, this orientation is transparent to the signal beam if it has the same polarization as the control beam and is absorbed when it is polarized orthogonally. We also present numerical simulations of the system using a comprehensive model which incorporates all the relevant Zeeman sub-levels in the system, and identify means to improve the performance of the polarizer. A novel algorithm to compute the evolution of large scale quantum system enabled us to perform this computation, which may have been considered too cumbersome to carry out previously. We describe how such a polarizer may serve as a key component for high-speed Stokesmetric imaging. We also show how such a polarizer, combined with an optically controlled waveplate, recently demonstrated by us, can be used to realize a high speed optical logic gate by making use of the Quantum Zeno Effect. Finally, we describe how such a logic gate can be realized at an ultra-low power level using a tapered nanofiber embedded in a vapor cell.

  5. Use of integrity control and automatic start of reserve in a multi-channel temperature and flow rate control device

    International Nuclear Information System (INIS)

    Strzalkowski, L.

    1975-01-01

    A way to increase reliability of process quantity control is control of the integrity of the control plants themselves. The possibilities of integrity control on control devices having simply duplicated control channels or working on the basis of the ''two-from-three'' principle are valued. A highly reliable integrity control is possible by use of test signals. For an appropriate control device, structure and function of the assemblies are described. The integrity control device may be used in the water coolant temperature and flow rate control system for all technological channels of the research reactor ''Maria''

  6. Groove-type channel enhancement-mode AlGaN/GaN MIS HEMT with combined polar and nonpolar AlGaN/GaN heterostructures

    International Nuclear Information System (INIS)

    Duan Xiao-Ling; Zhang Jin-Cheng; Xiao Ming; Zhao Yi; Ning Jing; Hao Yue

    2016-01-01

    A novel groove-type channel enhancement-mode AlGaN/GaN MIS high electron mobility transistor (GTCE-HEMT) with a combined polar and nonpolar AlGaN/GaN heterostucture is presented. The device simulation shows a threshold voltage of 1.24 V, peak transconductance of 182 mS/mm, and subthreshold slope of 85 mV/dec, which are obtained by adjusting the device parameters. Interestingly, it is possible to control the threshold voltage accurately without precisely controlling the etching depth in fabrication by adopting this structure. Besides, the breakdown voltage ( V B ) is significantly increased by 78% in comparison with the value of the conventional MIS-HEMT. Moreover, the fabrication process of the novel device is entirely compatible with that of the conventional depletion-mode (D-mode) polar AlGaN/GaN HEMT. It presents a promising way to realize the switch application and the E/D-mode logic circuits. (paper)

  7. Traffic Control Device Evaluation Program : FY 2017

    Science.gov (United States)

    2018-03-01

    This report presents findings on the activities conducted in the Traffic Control Device Evaluation Program during the 2017 fiscal year. The research on sponsored changeable message signs (continued from the previous year) was terminated by the Federa...

  8. Control rod excess withdrawal prevention device

    International Nuclear Information System (INIS)

    Takayama, Yoshihito.

    1992-01-01

    Excess withdrawal of a control rod of a BWR type reactor is prevented. That is, the device comprises (1) a speed detector for detecting the driving speed of a control rod, (2) a judging circuit for outputting an abnormal signal if the driving speed is greater than a predetermined level and (3) a direction control valve compulsory closing circuit for controlling the driving direction of inserting and withdrawing a control rod based on an abnormal signal. With such a constitution, when the with drawing speed of a control rod is greater than a predetermined level, it is detected by the speed detector and the judging circuit. Then, all of the direction control valve are closed by way of the direction control valve compulsory closing circuit. As a result, the operation of the control rod is stopped compulsorily and the withdrawing speed of the control rod can be lowered to a speed corresponding to that upon gravitational withdrawal. Accordingly, excess withdrawal can be prevented. (I.S)

  9. Design controls for the medical device industry

    CERN Document Server

    Teixeira, Marie B

    2013-01-01

    The second edition of a bestseller, Design Controls for the Medical Device Industry provides a comprehensive review of the latest design control requirements, as well as proven tools and techniques to ensure your company's design control program evolves in accordance with current industry practice. The text assists in the development of an effective design control program that not only satisfies the US FDA Quality System Regulation (QSR) and ISO 9001 and 13485 standards, but also meets today's third-party auditor/investigator expectations and saves you valuable time and money.The author's cont

  10. Motion control, motion sickness, and the postural dynamics of mobile devices.

    Science.gov (United States)

    Stoffregen, Thomas A; Chen, Yi-Chou; Koslucher, Frank C

    2014-04-01

    Drivers are less likely than passengers to experience motion sickness, an effect that is important for any theoretical account of motion sickness etiology. We asked whether different types of control would affect the incidence of motion sickness, and whether any such effects would be related to participants' control of their own bodies. Participants played a video game on a tablet computer. In the Touch condition, the device was stationary and participants controlled the game exclusively through fingertip inputs via the device's touch screen. In the Tilt condition, participants held the device in their hands and moved the device to control some game functions. Results revealed that the incidence of motion sickness was greater in the Touch condition than in the Tilt condition. During game play, movement of the head and torso differed as a function of the type of game control. Before the onset of subjective symptoms of motion sickness, movement of the head and torso differed between participants who later reported motion sickness and those that did not. We discuss implications of these results for theories of motion sickness etiology.

  11. Doubling transmission capacity in optical wireless system by antenna horizontal- and vertical-polarization multiplexing.

    Science.gov (United States)

    Li, Xinying; Yu, Jianjun; Zhang, Junwen; Dong, Ze; Chi, Nan

    2013-06-15

    We experimentally demonstrate 2×56 Gb/s two-channel polarization-division-multiplexing quadrature-phase-shift-keying signal delivery over 80 km single-mode fiber-28 and 2 m Q-band (33-50 GHz) wireless link, adopting antenna horizontal- (H-) and vertical-polarization (V-polarization) multiplexing. At the wireless receiver, classic constant-modulus-algorithm equalization based on digital signal processing can realize polarization demultiplexing and remove the crosstalk at the same antenna polarization. By adopting antenna polarization multiplexing, the signal baud rate and performance requirements for optical and wireless devices can be reduced but at the cost of double antennas and devices, while wireless transmission capacity can also be increased but at the cost of stricter requirements for V-polarization. The isolation is only about 19 dB when V-polarization deviation approaches 10°, which will affect high-speed (>50 Gb/s) wireless delivery.

  12. Control of the spin polarization of photoelectrons/photoions using short laser pulses

    International Nuclear Information System (INIS)

    Nakajima, Takashi

    2004-01-01

    We present a generic pump-probe scheme to control spin polarization of photoelectrons/photoions by short laser pulses. By coherently exciting fine structure manifolds of a multi-valence-electron system by the pump laser, a superposition of fine structure states is created. Since each fine structure state can be further decomposed into a superposition of various spin states of valence electrons, each spin component evolves differently in time. This means that varying the time delay between the pump and probe lasers leads to the control of spin states. Specific theoretical results are presented for two-valence-electron atoms, in particular for Mg, which demonstrate that not only the degree of spin polarization but also its sign can be manipulated through time delay. Since the underline physics is rather general and transparent, the presented idea may be potentially applied to nanostructures such as quantum wells and quantum dots

  13. Terahertz Focusing and Polarization Control in Large-Area Bias-Free Semiconductor Emitters

    Science.gov (United States)

    Carthy, Joanna L.; Gow, Paul C.; Berry, Sam A.; Mills, Ben; Apostolopoulos, Vasilis

    2018-03-01

    We show that, when large-area multiplex terahertz semiconductor emitters, that work on diffusion currents and Schottky potentials, are illuminated by ultrashort optical pulses they can radiate a directional electromagnetic terahertz pulse which is controlled by the angular spectrum of the incident optical beam. Using the lens that focuses the incident near-infrared pulse, we have demonstrated THz emission focusing in free space, at the same point where the optical radiation would focus. We investigated the beam waist and Gouy phase shift of the THz emission as a function of frequency. We also show that the polarization profile of the emitted THz can be tailored by the metallic patterning on the semiconductor, demonstrating radial polarization when a circular emitter design is used. Our techniques can be used for fast THz beam steering and mode control for efficiently coupling to waveguides without the need for THz lenses or parabolic mirrors.

  14. An Automatic Occlusion Device for Remote Control of Tumor Tissue Ischemia

    Science.gov (United States)

    El-Dahdah, Hamid; Wang, Bei; He, Guanglong; Xu, Ronald X.

    2015-01-01

    We developed an automatic occlusion device for remote control of tumor tissue ischemia. The device consists of a flexible cannula encasing a shape memory alloy wire with its distal end connected to surgical suture. Regional tissue occlusion was tested on both the benchtop and the animal models. In the benchtop test, the occlusion device introduced quantitative and reproducible changes of blood flow in a tissue simulating phantom embedding a vessel simulator. In the animal test, the device generated a cyclic pattern of reversible ischemia in the right hinder leg tissue of a black male C57BL/6 mouse. We also developed a multimodal detector that integrates near infrared spectroscopy and electron paramagnetic resonance spectroscopy for continuous monitoring of tumor tissue oxygenation, blood content, and oxygen tension changes. The multimodal detector was tested on a cancer xenograft nude mouse undergoing reversible tumor ischemia. The automatic occlusion device and the multi-modal detector can be potentially integrated for closed-loop feedback control of tumor tissue ischemia. Such an integrated occlusion device may be used in multiple clinical applications such as regional hypoperfusion control in tumor resection surgeries and thermal ablation processes. In addition, the proposed occlusion device can also be used as a research tool to understand tumor oxygen transport and hemodynamic characteristics. PMID:20082532

  15. Improving toxicity assessment of pesticide mixtures: the use of polar passive sampling devices extracts in microalgae toxicity tests

    Directory of Open Access Journals (Sweden)

    Sandra KIM TIAM

    2016-09-01

    Full Text Available Complexity of contaminants exposure needs to be taking in account for an appropriate evaluation of risks related to mixtures of pesticides released in the ecosystems. Toxicity assessment of such mixtures can be made through a variety of toxicity tests reflecting different level of biological complexity. This paper reviews the recent developments of passive sampling techniques for polar compounds, especially Polar Organic Chemical Integrative Samplers (POCIS and Chemcatcher® and the principal assessment techniques using microalgae in laboratory experiments. The progresses permitted by the coupled use of such passive samplers and ecotoxicology testing as well as their limitations are presented. Case studies combining passive sampling devices (PSD extracts and toxicity assessment toward microorganisms at different biological scales from single organisms to communities level are presented. These case studies, respectively aimed i at characterizing the toxic potential of waters using dose-response curves, and ii at performing microcosm experiments with increased environmental realism in the toxicant exposure in term of cocktail composition and concentration. Finally perspectives and limitations of such approaches for future applications in the area of environmental risk assessment are discussed.

  16. Device-dependent and device-independent quantum key distribution without a shared reference frame

    International Nuclear Information System (INIS)

    Slater, Joshua A; Tittel, Wolfgang; Branciard, Cyril; Brunner, Nicolas

    2014-01-01

    Standard quantum key distribution (QKD) protocols typically assume that the distant parties share a common reference frame. In practice, however, establishing and maintaining a good alignment between distant observers is rarely a trivial issue, which may significantly restrain the implementation of long-distance quantum communication protocols. Here we propose simple QKD protocols that do not require the parties to share any reference frame, and study their security and feasibility in both the usual device-dependent (DD) case—in which the two parties use well characterized measurement devices—as well as in the device-independent (DI) case—in which the measurement devices can be untrusted, and the security relies on the violation of a Bell inequality. To illustrate the practical relevance of these ideas, we present a proof-of-principle demonstration of our protocols using polarization entangled photons distributed over a coiled 10-km long optical fiber. We consider two situations, in which either the fiber spool's polarization transformation freely drifts, or randomly chosen polarization transformations are applied. The correlations obtained from measurements allow, with high probability, to generate positive asymptotic secret key rates in both the DD and DI scenarios (under the fair-sampling assumption for the latter case). (paper)

  17. Investigation of spin-polarized transport in GaAs nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Tierney, B D; Day, T E; Goodnick, S M [Department of Electrical Engineering and Center for Solid State Electronics Research Arizona State University, Tempe, AZ 85287-5706 (United States)], E-mail: brian.tierney@asu.edu

    2008-03-15

    A spin field effect transistor (spin-FET) has been fabricated that employs nanomagnets as components of quantum point contact (QPC) structures to inject spin-polarized carriers into the high-mobility two-dimensional electron gas (2DEG) of a GaAs quantum well and to detect them. A centrally-placed non-magnetic Rashba gate controls both the density of electrons in the 2DEG and the electronic spin precession. Initial results are presented for comparable device structures modeled with an ensemble Monte Carlo (EMC) method. In the EMC the temporal and spatial evolution of the ensemble carrier spin polarization is governed by a spin density matrix formalism that incorporates the Dresselhaus and Rashba contributions to the D'yakanov-Perel spin-flip scattering mechanism, the predominant spin scattering mechanism in AlGaAs/GaAs heterostructures from 77-300K.

  18. Polarization-independent transparency window induced by complementary graphene metasurfaces

    International Nuclear Information System (INIS)

    Lu, Wei Bing; Liu, Ji Long; Zhang, Jin; Wang, Jian; Liu, Zhen Guo

    2017-01-01

    A fourfold symmetric graphene-based complementary metasurface featuring a polarization-independent transparency window is proposed and numerically analysed in this paper. The unit cell of the metamaterial consists of a monolayer graphene perforated with a cross and four identical split-ring resonators deposited on a substrate. Our analysis shows that the transparency window can be interpreted as a plasmonic analogy of Autler–Townes splitting. The polarization independence is achieved due to the fourfold symmetry of graphene’s complementary structure. In addition, the frequency range of the transparency window can be dynamically tuned over a broad band by changing the chemical potential of graphene, and the width of the transparency window can also be controlled by changing the split-gap orientation. This work may lead to potential applications in many area, such as slow-light devices and optical sensing. (paper)

  19. Manipulation of the polarization of intense laser beams via optical wave mixing in plasmas

    Science.gov (United States)

    Michel, Pierre; Divol, Laurent; Turnbull, David; Moody, John

    2014-10-01

    When intense laser beams overlap in plasmas, the refractive index modulation created by the beat wave via the ponderomotive force can lead to optical wave mixing phenomena reminiscent of those used in crystals and photorefractive materials. Using a vector analysis, we present a full analytical description of the modification of the polarization state of laser beams crossing at arbitrary angles in a plasma. We show that plasmas can be used to provide full control of the polarization state of a laser beam, and give simple analytical estimates and practical considerations for the design of novel photonics devices such as plasma polarizers and plasma waveplates. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  20. High-Order Dielectric Metasurfaces for High-Efficiency Polarization Beam Splitters and Optical Vortex Generators

    Science.gov (United States)

    Guo, Zhongyi; Zhu, Lie; Guo, Kai; Shen, Fei; Yin, Zhiping

    2017-08-01

    In this paper, a high-order dielectric metasurface based on silicon nanobrick array is proposed and investigated. By controlling the length and width of the nanobricks, the metasurfaces could supply two different incremental transmission phases for the X-linear-polarized (XLP) and Y-linear-polarized (YLP) light with extremely high efficiency over 88%. Based on the designed metasurface, two polarization beam splitters working in high-order diffraction modes have been designed successfully, which demonstrated a high transmitted efficiency. In addition, we have also designed two vortex-beam generators working in high-order diffraction modes to create vortex beams with the topological charges of 2 and 3. The employment of dielectric metasurfaces operating in high-order diffraction modes could pave the way for a variety of new ultra-efficient optical devices.

  1. Room-Temperature Single-photon level Memory for Polarization States

    Science.gov (United States)

    Kupchak, Connor; Mittiga, Thomas; Jordaan, Bertus; Namazi, Mehdi; Nölleke, Christian; Figueroa, Eden

    2015-01-01

    An optical quantum memory is a stationary device that is capable of storing and recreating photonic qubits with a higher fidelity than any classical device. Thus far, these two requirements have been fulfilled for polarization qubits in systems based on cold atoms and cryogenically cooled crystals. Here, we report a room-temperature memory capable of storing arbitrary polarization qubits with a signal-to-background ratio higher than 1 and an average fidelity surpassing the classical benchmark for weak laser pulses containing 1.6 photons on average, without taking into account non-unitary operation. Our results demonstrate that a common vapor cell can reach the low background noise levels necessary for polarization qubit storage using single-photon level light, and propels atomic-vapor systems towards a level of functionality akin to other quantum information processing architectures.

  2. Re-active Passive (RAP) Devices for Control of Noise Transmission through a Panel

    Science.gov (United States)

    Carneal, James P.; Giovanardi, Marco; Fuller, Chris R.; Palumbo, Daniel L.

    2008-01-01

    Re-Active Passive (RAP) devices have been developed to control low frequency (transmission through a panel. These devices use a combination of active, re-active, and passive technologies packaged into a single unit to control a broad frequency range utilizing the strength of each technology over its best suited frequency range. The RAP device uses passive constrained layer damping to cover the relatively high frequency range (>200 Hz), reactive distributed vibration absorber) to cover the medium frequency range (75 to 250 Hz), and active control for controlling low frequencies (transmission through a panel mounted in a transmission loss test facility. Experimental results are presented for the bare panel, and combinations of passive treatment, reactive treatment, and active control. Results indicate that three RAP devices were able to increase the overall broadband (15-1000 Hz) transmission loss by 9.4 dB. These three devices added a total of 285 grams to the panel mass of 6.0 kg, or approximately 5%, not including control electronics.

  3. Scalability of voltage-controlled filamentary and nanometallic resistance memory devices.

    Science.gov (United States)

    Lu, Yang; Lee, Jong Ho; Chen, I-Wei

    2017-08-31

    Much effort has been devoted to device and materials engineering to realize nanoscale resistance random access memory (RRAM) for practical applications, but a rational physical basis to be relied on to design scalable devices spanning many length scales is still lacking. In particular, there is no clear criterion for switching control in those RRAM devices in which resistance changes are limited to localized nanoscale filaments that experience concentrated heat, electric current and field. Here, we demonstrate voltage-controlled resistance switching, always at a constant characteristic critical voltage, for macro and nanodevices in both filamentary RRAM and nanometallic RRAM, and the latter switches uniformly and does not require a forming process. As a result, area-scalability can be achieved under a device-area-proportional current compliance for the low resistance state of the filamentary RRAM, and for both the low and high resistance states of the nanometallic RRAM. This finding will help design area-scalable RRAM at the nanoscale. It also establishes an analogy between RRAM and synapses, in which signal transmission is also voltage-controlled.

  4. Transmission Magnitude and Phase Control for Polarization-Preserving Reflectionless Metasurfaces

    Science.gov (United States)

    Kwon, Do-Hoon; Ptitcyn, Grigorii; Díaz-Rubio, Ana; Tretyakov, Sergei A.

    2018-03-01

    For transmissive applications of electromagnetic metasurfaces, an array of subwavelength Huygens' meta-atoms are typically used to eliminate reflection and achieve a high-transmission power efficiency together with a wide transmission phase coverage. We show that the underlying principle of low reflection and full control over transmission is asymmetric scattering into the specular reflection and transmission directions that results from a superposition of symmetric and antisymmetric scattering components, with Huygens' meta-atoms being one example configuration. Available for oblique illumination in TM polarization, a meta-atom configuration comprising normal and tangential electric polarizations is presented, which is capable of reflectionless, full-power transmission and a 2 π transmission phase coverage as well as full absorption. For lossy metasurfaces, we show that a complete phase coverage is still available for reflectionless designs for any value of absorptance. Numerical examples in the microwave and optical regimes are provided.

  5. Comprehension of the Electric Polarization as a Function of Low Temperature

    Science.gov (United States)

    Liu, Changshi

    2017-01-01

    Polarization response to warming plays an increasingly important role in a number of ferroelectric memory devices. This paper reports on the theoretical explanation of the relationship between polarization and temperature. According to the Fermi-Dirac distribution, the basic property of electric polarization response to temperature in magnetoelectric multiferroic materials is theoretically analyzed. The polarization in magnetoelectric multiferroic materials can be calculated by low temperature using a phenomenological theory suggested in this paper. Simulation results revealed that the numerically calculated results are in good agreement with experimental results of some inhomogeneous multiferroic materials. Numerical simulations have been performed to investigate the influences of both electric and magnetic fields on the polarization in magnetoelectric multiferroic materials. Furthermore, polarization behavior of magnetoelectric multiferroic materials can be predicted by low temperature, electric field and magnetic induction using only one function. The calculations offer an insight into the understanding of the effects of heating and magnetoelectric field on electrical properties of multiferroic materials and offer a potential to use similar methods to analyze electrical properties of other memory devices.

  6. Ortho-Babinet polarization-interrogating filter: an interferometric approach to polarization measurement.

    Science.gov (United States)

    Van Delden, Jay S

    2003-07-15

    A novel, interferometric, polarization-interrogating filter assembly and method for the simultaneous measurement of all four Stokes parameters across a partially polarized irradiance image in a no-moving-parts, instantaneous, highly sensitive manner is described. In the reported embodiment of the filter, two spatially varying linear retarders and a linear polarizer comprise an ortho-Babinet, polarization-interrogating (OBPI) filter. The OBPI filter uniquely encodes the incident ensemble of electromagnetic wave fronts comprising a partially polarized irradiance image in a controlled, deterministic, spatially varying manner to map the complete state of polarization across the image to local variations in a superposed interference pattern. Experimental interferograms are reported along with a numerical simulation of the method.

  7. Control device for a nuclear reactor with a multitude of control rods, extending into the reactor core from above, with linear drive mechanisms and additional gripper devices

    International Nuclear Information System (INIS)

    Bevilacqua, F.

    1979-01-01

    The components of the additional gripper devices with magnetically operated finger-shaped latches are separated from the also magnetically operated latches of the linear drive mechanisms in order to avoid common-mode failures when fast shutdown is required. Only part of the safety rods are held by the additional gripping devices in the withdrawn position. There is provided for recording elements indicating positively which one of the safety locks is gearing with the control rods. At the upper end of each control rod there is a coupling head held by electromagnetically operated locking devices in the withdrawn position, if control power is available. (DG) [de

  8. Electronic control devices

    International Nuclear Information System (INIS)

    Hartill, D.L.

    1981-01-01

    The subject of these lectures is the translation of information from particle detectors to computers. Large solid angle general purpose detectors at the intersection regions of high energy e+e- storage rings and pp and pp storage rings are discussed. Three choices for data acquisition are reviewed: use CAMAC (Computer Aided Measurement and Control), start from scratch and design a system, or wait for the final version of the proposed FASTBUS to be developed. The do-it-yourself procedure includes designs of drift chamber discriminator, time to amplitude converter, and data card block diagram. Trigger systems, the fast decision making systems judging an event interesting enough for a read-out cycle to be initiated, are discussed. Finally, a FASTBUS system layout, with its goals of minimum bus speed, general system topologies, and support multiple smart devices is given

  9. SeleCon: Scalable IoT Device Selection and Control Using Hand Gestures.

    Science.gov (United States)

    Alanwar, Amr; Alzantot, Moustafa; Ho, Bo-Jhang; Martin, Paul; Srivastava, Mani

    2017-04-01

    Although different interaction modalities have been proposed in the field of human-computer interface (HCI), only a few of these techniques could reach the end users because of scalability and usability issues. Given the popularity and the growing number of IoT devices, selecting one out of many devices becomes a hurdle in a typical smarthome environment. Therefore, an easy-to-learn, scalable, and non-intrusive interaction modality has to be explored. In this paper, we propose a pointing approach to interact with devices, as pointing is arguably a natural way for device selection. We introduce SeleCon for device selection and control which uses an ultra-wideband (UWB) equipped smartwatch. To interact with a device in our system, people can point to the device to select it then draw a hand gesture in the air to specify a control action. To this end, SeleCon employs inertial sensors for pointing gesture detection and a UWB transceiver for identifying the selected device from ranging measurements. Furthermore, SeleCon supports an alphabet of gestures that can be used for controlling the selected devices. We performed our experiment in a 9 m -by-10 m lab space with eight deployed devices. The results demonstrate that SeleCon can achieve 84.5% accuracy for device selection and 97% accuracy for hand gesture recognition. We also show that SeleCon is power efficient to sustain daily use by turning off the UWB transceiver, when a user's wrist is stationary.

  10. Programmable liquid crystal waveplate polarization gratings as elements for polarimetric and interference applications

    Science.gov (United States)

    Moreno, I.; Davis, J. A.

    2010-06-01

    We review the use of a parallel aligned nematic liquid crystal spatial light modulator as a very useful and flexible device for polarimetric and interferometric applications. The device acts as a programmable pixelated waveplate, and the encoding of a linear grating permits its use as a polarization beam splitter. When a grating with a reduced period is encoded, the diffracted beams are spatially separated and the device can be used for polarimetric analysis. On the contrary when a large period grating is displayed, the beams are not spatially separated, and they are useful to realize a common path interferometric system with polarization sensitivity. The flexibility offered by the programmability of the display allows non-conventional uses, including the analysis of light beams with structured spatial polarizations.

  11. Real-Time Occupant Based Plug-in Device Control Using ICT in Office Buildings

    Directory of Open Access Journals (Sweden)

    Woo-Bin Bae

    2016-03-01

    Full Text Available The purpose of this study is to reduce the unnecessary plug loads used by computers, monitors, and computer peripheral devices, all of which account for more than 95% of the entire plug loads of an office building. To this end, an occupant-based plug-in device control (OBC-P software was developed. The OBC-P software collects real-time information about the presence or absence of occupants who are connected to the access point through the Wifi and controls the power of monitors or computers, while a standby power off device controls computer peripheral devices. To measure the plug load saving of the occupant-based plug-in device control, an experiment was conducted, targeting 10 occupants of three research labs of the graduate school, for two weeks. The experiment results showed that it could save the plug loads of monitors and computer peripheral devices by 15% in the Awake mode, and by 26% in the Sleep mode.

  12. Manipulation and control of the interfacial polarization in organic light-emitting diodes by dipolar doping

    Directory of Open Access Journals (Sweden)

    Lars Jäger

    2016-09-01

    Full Text Available Most of the commonly used electron transporting materials in organic light-emitting diodes exhibit interfacial polarization resulting from partially aligned permanent dipole moments of the molecules. This property modifies the internal electric field distribution of the device and therefore enables an earlier flat band condition for the hole transporting side, leading to improved charge carrier injection. Recently, this phenomenon was studied with regard to different materials and degradation effects, however, so far the influence of dilution has not been investigated. In this paper we focus on dipolar doping of the hole transporting material 4,4-bis[N-(1-naphthyl-N-phenylamino]-biphenyl (NPB with the polar electron transporting material tris-(8-hydroxyquinolate aluminum (Alq3. Impedance spectroscopy reveals that changes of the hole injection voltage do not scale in a simple linear fashion with the effective thickness of the doped layer. In fact, the measured interfacial polarization reaches a maximum value for a 1:1 blend. Taking the permanent dipole moment of Alq3 into account, an increasing degree of dipole alignment is found for decreasing Alq3 concentration. This observation can be explained by the competition between dipole-dipole interactions leading to dimerization and the driving force for vertical orientation of Alq3 dipoles at the surface of the NPB layer.

  13. Manipulation and control of the interfacial polarization in organic light-emitting diodes by dipolar doping

    Science.gov (United States)

    Jäger, Lars; Schmidt, Tobias D.; Brütting, Wolfgang

    2016-09-01

    Most of the commonly used electron transporting materials in organic light-emitting diodes exhibit interfacial polarization resulting from partially aligned permanent dipole moments of the molecules. This property modifies the internal electric field distribution of the device and therefore enables an earlier flat band condition for the hole transporting side, leading to improved charge carrier injection. Recently, this phenomenon was studied with regard to different materials and degradation effects, however, so far the influence of dilution has not been investigated. In this paper we focus on dipolar doping of the hole transporting material 4,4-bis[N-(1-naphthyl)-N-phenylamino]-biphenyl (NPB) with the polar electron transporting material tris-(8-hydroxyquinolate) aluminum (Alq3). Impedance spectroscopy reveals that changes of the hole injection voltage do not scale in a simple linear fashion with the effective thickness of the doped layer. In fact, the measured interfacial polarization reaches a maximum value for a 1:1 blend. Taking the permanent dipole moment of Alq3 into account, an increasing degree of dipole alignment is found for decreasing Alq3 concentration. This observation can be explained by the competition between dipole-dipole interactions leading to dimerization and the driving force for vertical orientation of Alq3 dipoles at the surface of the NPB layer.

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

    International Nuclear Information System (INIS)

    Makita, K.; Meng, C.

    1987-01-01

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

  15. A Multiposture Locomotor Training Device with Force-Field Control

    Directory of Open Access Journals (Sweden)

    Jianfeng Sui

    2014-11-01

    Full Text Available This paper introduces a multiposture locomotor training device (MPLTD with a closed-loop control scheme based on joint angle feedback, which is able to overcome various difficulties resulting from mechanical vibration and the weight of trainer to achieve higher accuracy trajectory. By introducing the force-field control scheme used in the closed-loop control, the device can obtain the active-constrained mode including the passive one. The MPLTD is mainly composed of three systems: posture adjusting and weight support system, lower limb exoskeleton system, and control system, of which the lower limb exoskeleton system mainly includes the indifferent equilibrium mechanism with two degrees of freedom (DOF and the driving torque is calculated by the Lagrangian function. In addition, a series of experiments, the weight support and the trajectory accuracy experiment, demonstrate a good performance of mechanical structure and the closed-loop control.

  16. Autotuning of PID controller by means of human machine interface device

    Directory of Open Access Journals (Sweden)

    Michał Awtoniuk

    2017-06-01

    Full Text Available More and more control systems are based on industry microprocessors like PLC controllers (Programmable Logic Controller. The most commonly used control algorithm is PID (Proportional-Integral-Derivative algorithm. Autotuning procedure is not available in every PLC. These controllers are typically used in cooperation with HMI (Human Machine Interface devices. In the study two procedures of autotuning of the PID controller were implemented in the HMI device: step method and relay method. Six tuning rules for step methods and one for relay method were chosen. The autotuning procedures on simulated controlled object and PLC controller without build-in autotuning were tested. The object of control was first order system plus time delay.

  17. Development and control of a magnetorheological haptic device for robot assisted surgery.

    Science.gov (United States)

    Shokrollahi, Elnaz; Goldenberg, Andrew A; Drake, James M; Eastwood, Kyle W; Kang, Matthew

    2017-07-01

    A prototype magnetorheological (MR) fluid-based actuator has been designed for tele-robotic surgical applications. This device is capable of generating forces up to 47 N, with input currents ranging from 0 to 1.5 A. We begin by outlining the physical design of the device, and then discuss a novel nonlinear model of the device's behavior. The model was developed using the Hammerstein-Wiener (H-W) nonlinear black-box technique and is intended to accurately capture the hysteresis behavior of the MR-fluid. Several experiments were conducted on the device to collect estimation and validation datasets to construct the model and assess its performance. Different estimating functions were used to construct the model, and their effectiveness is assessed based on goodness-of-fit and final-prediction-error measurements. A sigmoid network was found to have a goodness-of-fit of 95%. The model estimate was then used to tune a PID controller. Two control schemes were proposed to eliminate the hysteresis behavior present in the MR fluid device. One method uses a traditional force feedback control loop and the other is based on measuring the magnetic field using a Hall-effect sensor embedded within the device. The Hall-effect sensor scheme was found to be superior in terms of cost, simplicity and real-time control performance compared to the force control strategy.

  18. Tunable and switchable multi-wavelength erbium-doped fiber laser with highly nonlinear photonic crystal fiber and polarization controllers

    International Nuclear Information System (INIS)

    Liu, X M; Lin, A; Zhao, W; Lu, K Q; Wang, Y S; Zhang, T Y; Chung, Y

    2008-01-01

    We have proposed a novel multi-wavelength erbium-doped fiber laser by using two polarization controllers and a sampled chirped fiber Bragg grating(SC-FBG). On the assistance of SC-FBG, the proposed fiber lasers with excellent stability and uniformity are tunable and switchable by adjusting the polarization controllers. Our laser can stably lase two waves and up to eight waves simultaneously at room temperature

  19. Plasma surface interactions in controlled fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Ghendrih, Ph.; Becoulet, M.; Costanzo, L. [and others

    2000-07-01

    This report brings together all the contributions of EURATOM/CEA association to the 14. international conference on plasma surface interactions in controlled fusion devices. 24 papers are presented and they deal mainly with the ergodic divertor and the first wall of Tore-supra tokamak.

  20. Plasma surface interactions in controlled fusion devices

    International Nuclear Information System (INIS)

    Ghendrih, Ph.; Becoulet, M.; Costanzo, L.

    2000-07-01

    This report brings together all the contributions of EURATOM/CEA association to the 14. international conference on plasma surface interactions in controlled fusion devices. 24 papers are presented and they deal mainly with the ergodic divertor and the first wall of Tore-supra tokamak

  1. A simple optical fibre-linked remote control system for multiple devices

    Indian Academy of Sciences (India)

    We report on the development of a simple control system which can handle multiple devices through an optical fibre data link. The devices are controlled using a set of DACs through serial data communication via a serial port of a PC. Serial data from the PC get converted to parallel mode using a homemade “serial in ...

  2. Control rod position detection device

    International Nuclear Information System (INIS)

    Akita, Haruo; Ogiwara, Sakae.

    1996-01-01

    The device of the present invention is used in a back-up shut down system of an LMFBR type reactor which is easy for maintenance, has high reliability and can recognize the position of control rods accurately. Namely, a permanent magnet is disposed to a control rod extension tube connected to the lower portion of the control rod. The detector guide tube is disposed in the vicinity of the control rod extension tube. A detector having a detection coil is inserted into a detector tube. With such constitution, the control rod can be detected at one position using the following method. (1) the movement of the magnetic field of the permanent magnet is detected by the detection coil. (2) a plurality of grooves are formed on the control rod extension tube, and the movement of the grooves is detected. In addition, the detection coil is inserted into the detector guide tube, and the signals from the detection coil are inputted to a signal processing circuit disposed at the outside of the reactor vessel using an MI cable to enable the maintenance of the detector. Further, if the detector comprises a detection coil and an excitation coil, the position of a dropped control rod can be recognized at a plurality of points. (I.S.)

  3. [Microcomputer control of a LED stimulus display device].

    Science.gov (United States)

    Ohmoto, S; Kikuchi, T; Kumada, T

    1987-02-01

    A visual stimulus display system controlled by a microcomputer was constructed at low cost. The system consists of a LED stimulus display device, a microcomputer, two interface boards, a pointing device (a "mouse") and two kinds of software. The first software package is written in BASIC. Its functions are: to construct stimulus patterns using the mouse, to construct letter patterns (alphabet, digit, symbols and Japanese letters--kanji, hiragana, katakana), to modify the patterns, to store the patterns on a floppy disc, to translate the patterns into integer data which are used to display the patterns in the second software. The second software package, written in BASIC and machine language, controls display of a sequence of stimulus patterns in predetermined time schedules in visual experiments.

  4. Reactor feedwater control device

    International Nuclear Information System (INIS)

    Koshi, Yuji.

    1993-01-01

    In the device of the present invention, an excess response is not caused in a reactor feed water system even when voids are fluctuated by using an actual water level signal as a reactor water level signal. That is, a standard water level signal and a reactor water level signal are inputted to a comparator. An adder adds water level difference signal outputted from the comparator and mismatch flow rate signal prepared by multiplying the difference between a main steam flow rate signal and a feed water flow rate signal by a mismatch gain. A feed water controller integrates the added signal and outputs flow rate demand signal. A feed water system receives the flow rate demand signal as input. A water level calculation means is disposed to such a device for calculating an actual water level based on the change of coolant possessing amount of the reactor, and the output thereof is defined as a reactor water level signal. With such procedures, excessive elevation of water level of the reactor can be prevented even upon occurrence of void fluctuation phenomenon or the like in the reactor such as upon sole scram operation. Accordingly, plant shut down caused thereby can be avoided safely. (I.S.)

  5. Gas supply device

    International Nuclear Information System (INIS)

    Yamamoto, Tokihiro.

    1986-01-01

    Purpose: When injecting gas during plasma discharge, to prevent erronous operation of the piezoelectric valves due to vibrations and to inject gas into the vacuum vessel by accurately controlling gas flow. Constitution: The piezoelectric valve designed to control the flow of gas when charging vacuum vessels is installed between the vacuum vessel and the gas cylinder and a pulse voltage generator to control the valve (open/close) and the reverse voltage generator to apply a reverse current to the valve element are also provided. When a voltage is applied to the piezoelectric element, the piezoelectric element bends. However, when the polarity is changed, the direction of the bend is also reversed. The seat portion is pressed in proportion to the degree of bending. When gas is injected while plasma is being discharged, the gap created, due to vibrations, between the piezoelectric element and the sealing material is prevented by the application of a reverse current. This allows precise control of the gas injection volume as well as the injection interval. This assures maintenance of precise test conditions when testing thermonuclear devices. (Horiuchi, T.)

  6. Fuel control device for various gas turbine configurations

    Energy Technology Data Exchange (ETDEWEB)

    Stearns, C F; Tutherly, H W

    1980-09-29

    The hydromechanic fuel control device can be adapted for various engine configurations as for example turbofan-, turbopro-, and turboshaft engines by providing those elements which are common for all engine configurations in the main housing and a detachable block for each individual configuration with all control elements and flow channels necessary for the respective configuration.

  7. Emergent chirality in the electric polarization texture of titanate superlattices.

    Science.gov (United States)

    Shafer, Padraic; García-Fernández, Pablo; Aguado-Puente, Pablo; Damodaran, Anoop R; Yadav, Ajay K; Nelson, Christopher T; Hsu, Shang-Lin; Wojdeł, Jacek C; Íñiguez, Jorge; Martin, Lane W; Arenholz, Elke; Junquera, Javier; Ramesh, Ramamoorthy

    2018-01-30

    Chirality is a geometrical property by which an object is not superimposable onto its mirror image, thereby imparting a handedness. Chirality determines many important properties in nature-from the strength of the weak interactions according to the electroweak theory in particle physics to the binding of enzymes with naturally occurring amino acids or sugars, reactions that are fundamental for life. In condensed matter physics, the prediction of topologically protected magnetic skyrmions and related spin textures in chiral magnets has stimulated significant research. If the magnetic dipoles were replaced by their electrical counterparts, then electrically controllable chiral devices could be designed. Complex oxide BaTiO 3 /SrTiO 3 nanocomposites and PbTiO 3 /SrTiO 3 superlattices are perfect candidates, since "polar vortices," in which a continuous rotation of ferroelectric polarization spontaneously forms, have been recently discovered. Using resonant soft X-ray diffraction, we report the observation of a strong circular dichroism from the interaction between circularly polarized light and the chiral electric polarization texture that emerges in PbTiO 3 /SrTiO 3 superlattices. This hallmark of chirality is explained by a helical rotation of electric polarization that second-principles simulations predict to reside within complex 3D polarization textures comprising ordered topological line defects. The handedness of the texture can be topologically characterized by the sign of the helicity number of the chiral line defects. This coupling between the optical and novel polar properties could be exploited to encode chiral signatures into photon or electron beams for information processing.

  8. Polarization-dependent photoluminescence studies of semipolar and nonpolar InGaN quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Schade, Lukas; Schwarz, Ulrich [IAF, Freiburg (Germany); Wernicke, Tim; Weyers, Markus [FBH, Berlin (Germany); Kneissl, Michael [FBH, Berlin (Germany); Institute of Solid State Physics, TU Berlin (Germany)

    2010-07-01

    Light emitted from optical devices based on semi- and nonpolar GaN quantum well (QW) structures is partially or totally polarized, as a consequence of crystal symmetry and band structure. This can be an additional advantage over polar (0001)GaN in specific applications, e.g. in LED backlighting. Fundamentally, the polarized emission stems from breaking the isotropic symmetry of the hexagonal c-plane, resulting in two discrete semi- and nonpolar directions (parallel and normal to the projection of (0001)). We use the k.p method to simulate the crystal-direction dependent emission. The resulting transition matrix elements assign a specific (partial) polarization for each subband. The thermal occupation of the subbands results in a temperature dependent effective polarization of the light emission. We study MOVPE grown homoepitactical polar, semi- and nonpolar samples, measuring the polarization properties of the resonantly excited photoluminescence from the QW. With the complete polarization of the subbands for nonpolar devices it is possible to measure the energetic difference of the first two valence band levels. In contrast to our calculations we find a higher degree of polarization also in semipolar directions. A possible explanation could be a higher energetic subband difference than computed.

  9. Measurement of pzz of the laser-driven polarized deuterium target

    International Nuclear Information System (INIS)

    Jones, C.E.; Coulter, K.P.; Holt, R.J.; Poelker, M.; Potterveld, D.P.; Kowalczyk, R.S.; Buchholz, M.; Neal, J.; van den Brand, J.F.J.

    1993-01-01

    The question of whether nuclei are polarized as a result of H-H (D-D) spin-exchange collisions within the relatively dense gas of a laser-driven source of polarized hydrogen (deuterium) can be addressed directly by measuring the nuclear polarization of atoms from the source. The feasibility of using a polarimeter based on the D + T → n + 4 He reaction to measure the tensor polarization of deuterium in an internal target fed by the laser-driven source has been tested. The device and the measurements necessary to test the spin-exchange polarization theory are described

  10. Non-Hebbian learning implementation in light-controlled resistive memory devices.

    Science.gov (United States)

    Ungureanu, Mariana; Stoliar, Pablo; Llopis, Roger; Casanova, Fèlix; Hueso, Luis E

    2012-01-01

    Non-Hebbian learning is often encountered in different bio-organisms. In these processes, the strength of a synapse connecting two neurons is controlled not only by the signals exchanged between the neurons, but also by an additional factor external to the synaptic structure. Here we show the implementation of non-Hebbian learning in a single solid-state resistive memory device. The output of our device is controlled not only by the applied voltages, but also by the illumination conditions under which it operates. We demonstrate that our metal/oxide/semiconductor device learns more efficiently at higher applied voltages but also when light, an external parameter, is present during the information writing steps. Conversely, memory erasing is more efficiently at higher applied voltages and in the dark. Translating neuronal activity into simple solid-state devices could provide a deeper understanding of complex brain processes and give insight into non-binary computing possibilities.

  11. Device for controlling the hydraulic lifter of drilling unit

    Energy Technology Data Exchange (ETDEWEB)

    Kraskov, P N

    1981-04-10

    A device is suggested for controlling the hydraulic lifter of a drilling unit. It contains a throttling valve with cylinder for servocontrol, mechanism for assigning the program for lowering velocity connected to the power cylinder, and oil tank. In order to improve the reliable concentration of the drilling unit by guaranteeing possible alternation for halting descent when the string falls on a projection in the well, the device is equipped with a normally open two-position hydraulically controlled distributor with spring return connected to the working surface of the power cylinder and valve connected to it with logical function of ILI for hydraulic control of the normally opened two-position distributor. The latter connects the working cavity of the servocontrol cylinder with the oil tank.

  12. Voltage-Controlled Reconfigurable Spin-Wave Nanochannels and Logic Devices

    Science.gov (United States)

    Rana, Bivas; Otani, YoshiChika

    2018-01-01

    Propagating spin waves (SWs) promise to be a potential information carrier in future spintronics devices with lower power consumption. Here, we propose reconfigurable nanochannels (NCs) generated by voltage-controlled magnetic anisotropy (VCMA) in an ultrathin ferromagnetic waveguide for SW propagation. Numerical micromagnetic simulations are performed to demonstrate the confinement of magnetostatic forward volumelike spin waves in NCs by VCMA. We demonstrate that the NCs, with a width down to a few tens of a nanometer, can be configured either into a straight or curved structure on an extended SW waveguide. The key advantage is that either a single NC or any combination of a number of NCs can be easily configured by VCMA for simultaneous propagation of SWs either with the same or different wave vectors according to our needs. Furthermore, we demonstrate the logic operation of a voltage-controlled magnonic xnor and universal nand gate and propose a voltage-controlled reconfigurable SW switch for the development of a multiplexer and demultiplexer. We find that the NCs and logic devices can even be functioning in the absence of the external-bias magnetic field. These results are a step towards the development of all-voltage-controlled magnonic devices with an ultralow power consumption.

  13. A device for automatic photoelectric control of the analytical gap for emission spectrographs

    Science.gov (United States)

    Dietrich, John A.; Cooley, Elmo F.; Curry, Kenneth J.

    1977-01-01

    A photoelectric device has been built that automatically controls the analytical gap between electrodes during excitation period. The control device allows for precise control of the analytical gap during the arcing process of samples, resulting in better precision of analysis.

  14. SeleCon: Scalable IoT Device Selection and Control Using Hand Gestures

    Science.gov (United States)

    Alanwar, Amr; Alzantot, Moustafa; Ho, Bo-Jhang; Martin, Paul; Srivastava, Mani

    2018-01-01

    Although different interaction modalities have been proposed in the field of human-computer interface (HCI), only a few of these techniques could reach the end users because of scalability and usability issues. Given the popularity and the growing number of IoT devices, selecting one out of many devices becomes a hurdle in a typical smarthome environment. Therefore, an easy-to-learn, scalable, and non-intrusive interaction modality has to be explored. In this paper, we propose a pointing approach to interact with devices, as pointing is arguably a natural way for device selection. We introduce SeleCon for device selection and control which uses an ultra-wideband (UWB) equipped smartwatch. To interact with a device in our system, people can point to the device to select it then draw a hand gesture in the air to specify a control action. To this end, SeleCon employs inertial sensors for pointing gesture detection and a UWB transceiver for identifying the selected device from ranging measurements. Furthermore, SeleCon supports an alphabet of gestures that can be used for controlling the selected devices. We performed our experiment in a 9m-by-10m lab space with eight deployed devices. The results demonstrate that SeleCon can achieve 84.5% accuracy for device selection and 97% accuracy for hand gesture recognition. We also show that SeleCon is power efficient to sustain daily use by turning off the UWB transceiver, when a user’s wrist is stationary. PMID:29683151

  15. Wurtzite BAlN and BGaN alloys for heterointerface polarization engineering

    KAUST Repository

    Liu, Kaikai

    2017-11-30

    The spontaneous polarization (SP) and piezoelectric (PZ) constants of BxAl1-xN and BxGa1-xN (0 ≤ x ≤ 1) ternary alloys were calculated with the hexagonal structure as reference. The SP constants show moderate nonlinearity due to the volume deformation and the dipole moment difference between the hexagonal and wurtzite structures. The PZ constants exhibit significant bowing because of the large lattice difference between binary alloys. Furthermore, the PZ constants of BxAl1-xN and BxGa1-xN become zero at boron compositions of ∼87% and ∼74%, respectively, indicating non-piezoelectricity. The large range of SP and PZ constants of BxAl1-xN (BAlN) and BxGa1-xN (BGaN) can be beneficial for the compound semiconductor device development. For instance, zero heterointerface polarization ΔP can be formed for BAlN and BGaN based heterojunctions with proper B compositions, potentially eliminating the quantum-confined Stark effect for c-plane optical devices and thus removing the need of non-polar layers and substrates. Besides, large heterointerface polarization ΔP is available that is desirable for electronic devices.

  16. 40 CFR 63.985 - Nonflare control devices used to control emissions from storage vessels and low throughput...

    Science.gov (United States)

    2010-07-01

    ... included. (E) For condensers, the design evaluation shall include the final temperature of the stream vapors, the type of condenser, and the design flow rate of the emission stream. (ii) Performance test. A... control device design evaluation or performance test requirements. When using a control device other than...

  17. Controlling Access to Input/Output Peripheral Devices

    Directory of Open Access Journals (Sweden)

    E. Y. Rodionov

    2010-03-01

    Full Text Available In this paper the author proposes a system that manages information security policy on enterprise. Problems related to managing information security policy on enterprise and access to peripheral devices in computer systems functioning under control of Microsoft Windows NT operating systems are considered.

  18. Algorithm for Public Electric Transport Schedule Control for Intelligent Embedded Devices

    Science.gov (United States)

    Alps, Ivars; Potapov, Andrey; Gorobetz, Mikhail; Levchenkov, Anatoly

    2010-01-01

    In this paper authors present heuristics algorithm for precise schedule fulfilment in city traffic conditions taking in account traffic lights. The algorithm is proposed for programmable controller. PLC is proposed to be installed in electric vehicle to control its motion speed and signals of traffic lights. Algorithm is tested using real controller connected to virtual devices and real functional models of real tram devices. Results of experiments show high precision of public transport schedule fulfilment using proposed algorithm.

  19. Plant control device

    International Nuclear Information System (INIS)

    Sato, Masuo; Ono, Makoto.

    1995-01-01

    A plant control device comprises an intellectual instrumentation group for measuring a predetermined process amount, an intellectual equipment group operating in accordance with a self-countermeasure, a system information space for outputting system information, a system level monitoring and diagnosing information generalization section for outputting system information, a system level maintenance information generalization section for outputting information concerning maintenance, a plant level information space and a plant level information generalization section. Each of them determines a state of the plant autonomously, and when abnormality is detected, each of the intellectual instrumentation, equipments and systems exchange information with each other, to conduct required operations including operations of intellectual robots, as required. Appropriate countermeasures for gauges, equipments and systems can be conducted autonomously at a place where operators can not access to improve reliability of complicate operations in the working site, as well as improve plant safety and reliability. (N.H.)

  20. Proceedings of the Japan-US workshop on plasma polarization spectroscopy and the fourth international symposium on plasma polarization spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Takashi; Beiersdorfer, Peter [eds.

    2004-07-01

    The international meeting on Plasma Polarization Spectroscopy (PPS) was held at Kyoto University during February 4-6, 2004. This Proceedings book includes the summaries of the talks given in that meeting. Starting with the Overview talk by Csanak, the subjects cover: x-ray polarization experiments on z-pinches (plasma foci), and an x-pinch, a laser-produced plasma in a gas atmosphere, an interpretation of the polarized 1<- 0 x-ray laser line, polarization observation from various laser-produced plasmas including a recombining phase plasma, a report on the on-going project of a laser facility, several polarization observations on magnetically confined plasmas including the Large Helical Device and an ECR plasma, a new laser-induced fluorescence diagnostic method. On atomic physics side given are: various polarization measurements on EBIT, precision spectroscopy on the TEXTOR, user-friendly atomic codes. Instrumentation is also a subject of this book. The 18 of the presented papers are indexed individually. (J.P.N.)

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

    Science.gov (United States)

    Laghaei, M.; Heidari Semiromi, E.

    2018-03-01

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

  2. A molecular spin-photovoltaic device.

    Science.gov (United States)

    Sun, Xiangnan; Vélez, Saül; Atxabal, Ainhoa; Bedoya-Pinto, Amilcar; Parui, Subir; Zhu, Xiangwei; Llopis, Roger; Casanova, Fèlix; Hueso, Luis E

    2017-08-18

    We fabricated a C 60 fullerene-based molecular spin-photovoltaic device that integrates a photovoltaic response with the spin transport across the molecular layer. The photovoltaic response can be modified under the application of a small magnetic field, with a magnetophotovoltage of up to 5% at room temperature. Device functionalities include a magnetic current inverter and the presence of diverging magnetocurrent at certain illumination levels that could be useful for sensing. Completely spin-polarized currents can be created by balancing the external partially spin-polarized injection with the photogenerated carriers. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  3. Microtubule dynamics of the centrosome-like polar organizers from the basal land plant Marchantia polymorpha.

    Science.gov (United States)

    Buschmann, Henrik; Holtmannspötter, Michael; Borchers, Agnes; O'Donoghue, Martin-Timothy; Zachgo, Sabine

    2016-02-01

    The liverwort Marchantia employs both modern and ancestral devices during cell division: it forms preprophase bands and in addition it shows centrosome-like polar organizers. We investigated whether polar organizers and preprophase bands cooperate to set up the division plane. To this end, two novel green fluorescent protein-based microtubule markers for dividing cells of Marchantia were developed. Cells of the apical notch formed polar organizers first and subsequently assembled preprophase bands. Polar organizers were formed de novo from multiple mobile microtubule foci localizing to the nuclear envelope. The foci then became concentrated by bipolar aggregation. We determined the comet production rate of polar organizers and show that microtubule plus ends of astral microtubules polymerize faster than those found on cortical microtubules. Importantly, it was observed that conditions increasing polar organizer numbers interfere with preprophase band formation. The data show that polar organizers have much in common with centrosomes, but that they also have specialized features. The results suggest that polar organizers contribute to preprophase band formation and in this way are involved in controlling the division plane. Our analyses of the basal land plant Marchantia shed new light on the evolution of plant cell division. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  4. Measuring device for control rod driving time

    International Nuclear Information System (INIS)

    Tanaka, Kazuhiko; Hanabusa, Masatoshi.

    1993-01-01

    The present invention concerns a measuring device for control driving time having a function capable of measuring a selected control rod driving time and measuring an entire control rod driving time simultaneously. A calculation means and a store means for the selected rod control rod driving time, and a calculation means and a store means for the entire control rod driving time are disposed individually. Each of them measures the driving time and stores the data independent of each other based on a selected control rod insert ion signal and an entire control rod insertion signal. Even if insertion of selected and entire control rods overlaps, each of the control rod driving times can be measured reliably to provide an advantageous effect capable of more accurately conducting safety evaluation for the nuclear reactor based on the result of the measurement. (N.H.)

  5. Modular manual control device for manipulators

    International Nuclear Information System (INIS)

    Dzholdasbekov, U.A.; Lukyanov, A.T.; Slutsky, L.I.; Safontsev, E.A.; Dzhamalov, N.K.

    1991-01-01

    The device described in this patent comprises a base, a series of connected modules, each with a position pickup and a handle. One module is provided for each degree of mobility of the manipulator being controlled; the modular construction enables the control of manipulators with differing degrees of mobility. One rotary movement module and three orthogonal linear movement modules are provided. Each linear module has two parallel guides between which a carriage is supported for movement by balls. The position pickup is provided on the carriage. The rotary module comprises inner and outer casings, relative movement of which is detected by pickup. Further rotary pickups may be provided for rotation about axes. A close/open switch and a speed control pickup may also be provided. (author)

  6. A cryostat to hold frozen-spin polarized HD targets in CLAS: HDice-II

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, M.M., E-mail: mlowry@jlab.org [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Bass, C.D. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); D' Angelo, A. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Universita' di Roma ‘Tor Vergata’, and INFN Sezione di Roma ‘Tor Vergata’, Via della Ricerca Scientifica, 1, I-00133 Roma (Italy); Deur, A.; Dezern, G. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Hanretty, C. [University of Virginia, 1400 University Avenue, Charlottesville, VA 22903 (United States); Ho, D. [Carnegie-Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States); Kageya, T.; Kashy, D. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Khandaker, M. [Norfolk State University, 700 Park Avenue, Norfolk, VA 23504 (United States); Laine, V. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Université Blaise Pascal, 34 Avenue Carnot, 63000 Clermont-Ferrand (France); O' Connell, T. [University of Connecticut, 115 N Eagleville Road, Storrs-Mansfield, CT 06269 (United States); Pastor, O. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Peng, P. [University of Virginia, 1400 University Avenue, Charlottesville, VA 22903 (United States); Sandorfi, A.M. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Sokhan, D. [Institut de Physique Nucleaire, Bat 100 – M053, Orsay 91406 (France); and others

    2016-04-11

    The design, fabrication, operation, and performance of a {sup 3/4}He dilution refrigerator and superconducting magnet system for holding a frozen-spin polarized hydrogen deuteride target in the Jefferson Laboratory CLAS detector during photon beam running is reported. The device operates both vertically (for target loading) and horizontally (for target bombardment). The device proves capable of maintaining a base temperature of 50 mK and a holding field of 1 T for extended periods. These characteristics enabled multi-month polarization lifetimes for frozen spin HD targets having proton polarization of up to 50% and deuteron up to 27%.

  7. Polarization encoded all-optical multi-valued shift operators

    Science.gov (United States)

    Roy, Jitendra Nath; Bhowmik, Panchatapa

    2014-08-01

    Polarization encoded multi-valued (both ternary and quaternary logic) shift operators have been designed using linear optical devices only. There are six ternary and 24 quaternary shift operators in multi-valued system. These are also known as reversible literals. This circuit will be useful in future all-optical multi-valued logic based information processing system. Different states of polarization of light are taken as different logic states.

  8. Thin film polarizer and color filter based on photo-polymerizable nematic liquid crystal

    Science.gov (United States)

    Mohammadimasoudi, Mohammad; Neyts, Kristiaan; Beeckman, Jeroen

    2015-03-01

    We present a method to fabricate a thin film color filter based on a mixture of photo-polymerizable liquid crystal and chiral dopant. A chiral nematic liquid crystal layer reflects light for a certain wavelength interval Δλ (= Δn.P) with the period and Δn the birefringence of the liquid crystal. The reflection band is determined by the chiral dopant concentration. The bandwidth is limited to 80nm and the reflectance is at most 50% for unpolarized incident light. The thin color filter is interesting for innovative applications like polarizer-free reflective displays, polarization-independent devices, stealth technologies, or smart switchable reflective windows to control solar light and heat. The reflected light has strong color saturation without absorption because of the sharp band edges. A thin film polarizer is developed by using a mixture of photo-polymerizable liquid crystal and color-neutral dye. The fabricated thin film absorbs light that is polarized parallel to the c axis of the LC. The obtained polarization ratio is 80% for a film of only 12 μm. The thin film polarizer and the color filter feature excellent film characteristics without domains and can be detached from the substrate which is useful for e.g. flexible substrates.

  9. Control Board Digital Interface Input Devices – Touchscreen, Trackpad, or Mouse?

    Energy Technology Data Exchange (ETDEWEB)

    Thomas A. Ulrich; Ronald L. Boring; Roger Lew

    2015-08-01

    The authors collaborated with a power utility to evaluate input devices for use in the human system interface (HSI) for a new digital Turbine Control System (TCS) at a nuclear power plant (NPP) undergoing a TCS upgrade. A standalone dynamic software simulation of the new digital TCS and a mobile kiosk were developed to conduct an input device study to evaluate operator preference and input device effectiveness. The TCS software presented the anticipated HSI for the TCS and mimicked (i.e., simulated) the turbine systems’ responses to operator commands. Twenty-four licensed operators from the two nuclear power units participated in the study. Three input devices were tested: a trackpad, mouse, and touchscreen. The subjective feedback from the survey indicates the operators preferred the touchscreen interface. The operators subjectively rated the touchscreen as the fastest and most comfortable input device given the range of tasks they performed during the study, but also noted a lack of accuracy for selecting small targets. The empirical data suggest the mouse input device provides the most consistent performance for screen navigation and manipulating on screen controls. The trackpad input device was both empirically and subjectively found to be the least effective and least desired input device.

  10. Synthesis of focused beam with controllable arbitrary homogeneous polarization using engineered vectorial optical fields.

    Science.gov (United States)

    Rui, Guanghao; Chen, Jian; Wang, Xiaoyan; Gu, Bing; Cui, Yiping; Zhan, Qiwen

    2016-10-17

    The propagation and focusing properties of light beams continue to remain a research interest owning to their promising applications in physics, chemistry and biological sciences. One of the main challenges to these applications is the control of polarization distribution within the focal volume. In this work, we propose and experimentally demonstrate a method for generating a focused beam with arbitrary homogeneous polarization at any transverse plane. The required input field at the pupil plane of a high numerical aperture objective lens can be found analytically by solving an inverse problem with the Richard-Wolf vectorial diffraction method, and can be experimentally created with a vectorial optical field generator. Focused fields with various polarizations are successfully generated and verified using a Stokes parameter measurement to demonstrate the capability and versatility of proposed technique.

  11. The polarized neutron small-angle scattering instrument at BENSC Berlin

    International Nuclear Information System (INIS)

    Keller, T.; Krist, T.; Danzig, A.; Keiderling, U.; Mezei, F.; Wiedenmann, A.

    2000-01-01

    A polarized neutron beam has been installed at the small-angle neutron-scattering instrument V4 at BENSC Berlin. The main component of this new option is a 1.8 m long cavity transmission polarizer. The advantages of this device compared to the conventional bender polarizers are: (i) high transmission (35% of unpolarized beam at λ=6 A); (ii) the polarization is better than 93% in the wavelength band 4 A 3 O 4 particles embedded in a glass matrix) are presented and compared to a measurement with unpolarized neutrons

  12. RIO EPICS device support application case study on an ion source control system (ISHP)

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, Diego [UPM – Universidad Politécnica de Madrid, Madrid (Spain); Ruiz, Mariano, E-mail: mariano.ruiz@upm.es [UPM – Universidad Politécnica de Madrid, Madrid (Spain); Eguiraun, Mikel [Department of Electricity and Electronic, Faculty of Science and Technology, University of Basque Country, Bilbao (Spain); Arredondo, Iñigo [ESS Bilbao Consortium, Zamudio (Spain); Badillo, Inari; Jugo, Josu [Department of Electricity and Electronic, Faculty of Science and Technology, University of Basque Country, Bilbao (Spain); Vega, Jesús; Castro, Rodrigo [Asociación EURATOM/CIEMAT, Madrid (Spain)

    2015-10-15

    Highlights: • A use case example of RIO/FlexRIO design methodology is described. • Ion source device is controlled and monitored by means EPICS IOCs. • NIRIO EPICS device support demonstrates that is able to manage RIO devices. • Easy and fast deployment is possible using RIO/FlexRIO design methodology using NIRIO-EDS. • RIO/FlexRIO technology and EPICS are a good combination for support large scale experiments in fusion environments. - Abstract: Experimental Physics and Industrial Control System (EPICS) is a software tool that during last years has become relevant as a main framework to deploy distributed control systems in large scientific environments. At the moment, ESS Bilbao uses this middleware to perform the control of their Ion Source Hydrogen Positive (ISHP) project. The implementation of the control system was based on: PXI Real Time controllers using the LabVIEW-RT and LabVIEW-EPICS tools; and RIO devices based on Field-Programmable Gate Array (FPGA) technology. Intended to provide a full compliant EPICS IOCs for RIO devices and to avoid additional efforts on the system maintainability, a migration of the current system to a derivative Red Hat Linux (CentOS) environment has been conducted. This paper presents a real application case study for using the NIRIO EPICS device support (NIRIO-EDS) to give support to the ISHP. Although RIO FPGA configurations are particular solutions for ISHP performance, the NIRIO-EDS has permitted the control and monitoring of devices by applying a well-defined design methodology into the previous FPGA configuration for RIO/FlexRIO devices. This methodology has permitted a fast and easy deployment for the new robust, scalable and maintainable software to support RIO devices into the ISHP control architecture.

  13. Control solutions for robots using Android and iOS devices

    Science.gov (United States)

    Evans, A. William, III; Gray, Jeremy P.; Rudnick, Dave; Karlsen, Robert E.

    2012-06-01

    As more Soldiers seek to utilize robots to enhance their mission capabilities, controls are needed which are intuitive, portable, and adaptable to a wide range of mission tasks. Android™ and iOS™ devices have the potential to meet each of these requirements as well as being based on readily available hardware. This paper will focus on some of the ways in which an Android™ or iOS™ device could be used to control specific and varied robot mobility functions and payload tools. Several small unmanned ground vehicle (SUGV) payload tools will have been investigated at Camp Pendleton during a user assessment and mission feasibility study for automatic remote tool changing. This group of payload tools will provide a basis, to researchers, concerning what types of control functions are needed to fully utilize SUGV robotic capabilities. Additional, mobility functions using tablet devices have been used as part of the Safe Operation of Unmanned systems for Reconnaissance in Complex Environments Army Technology Objective (SOURCE ATO) which is investigating the safe operation of robotics. Using Android™ and iOS™ hand-held devices is not a new concept in robot manipulation. However, the authors of this paper hope to introduce some novel concepts that may serve to make the interaction between Soldier and machine more fluid and intuitive. By creating a better user experience, Android™ and iOS™ devices could help to reduce training time, enhance performance, and increase acceptance of robotics as valuable mission tools for Soldiers.

  14. X-Parameter Based Modelling of Polar Modulated Power Amplifiers

    DEFF Research Database (Denmark)

    Wang, Yelin; Nielsen, Troels Studsgaard; Sira, Daniel

    2013-01-01

    X-parameters are developed as an extension of S-parameters capable of modelling non-linear devices driven by large signals. They are suitable for devices having only radio frequency (RF) and DC ports. In a polar power amplifier (PA), phase and envelope of the input modulated signal are applied...... at separate ports and the envelope port is neither an RF nor a DC port. As a result, X-parameters may fail to characterise the effect of the envelope port excitation and consequently the polar PA. This study introduces a solution to the problem for a commercial polar PA. In this solution, the RF-phase path...... PA for simulations. The simulated error vector magnitude (EVM) and adjacent channel power ratio (ACPR) were compared with the measured data to validate the model. The maximum differences between the simulated and measured EVM and ACPR are less than 2% point and 3 dB, respectively....

  15. Brain Computer Interface-Controlling Devices Utilizing The Alpha Brain Waves

    Directory of Open Access Journals (Sweden)

    Rohan Hundia

    2015-01-01

    Full Text Available Abstract This paper describes the development and testing of an interface system whereby one can control external devices by voluntarily controlling alpha waves that is through eye movement. Such a system may be used for the control of prosthetics robotic arms and external devices like wheelchairs using the alpha brain waves and the Mu rhythm. The response generated through the movement of the eye detecting and controlling the amplitude of the alpha brain waves is interfaced and processed to control Robotic systems and smart home control. In order to measure the response of alpha waves over different lobes of the brain initially I measured these signals over 32 regions using silver chloride plated electrodes. By the opening and the closure of the eyes and the movement in the up-down left-right directions and processing these movements measuring them over the occipital region I was able to differentiate the amplitude of the alpha waves generated due to these several movements. In the First session testing period subjects were asked to close and open their eyes and they were able to control limited movements of a Robot and a prosthetic arm. In the Second 2session the movement of the eyes was also considered left-right up-down along with the opening and closure during this time span they were able to control more dimensions of the robot several devices at the same time using different eye movements.

  16. Controlled higher-order transverse mode conversion from a fiber laser by polarization manipulation

    Science.gov (United States)

    Huang, Bin; Yi, Qian; Yang, Lingling; Zhao, Chujun; Wen, Shuangchun

    2018-02-01

    We report a vectorial fiber laser with controlled transverse mode conversion by intra-cavity polarization manipulation. By combining a q-plate and two quarter-wave plates (QWPs), we can generate a switchable polarization state output represented by the higher-order Poincaré sphere (l = +1, l = -1), and distinguish the fourfold degenerate LP11 mode. The four transverse vector modes can be obtained and switched in a flexible way, and the slope efficiency of the fiber laser can reach up to 39.4%. This compactness, high efficiency, and switchable operation potential will benefit a range of applications, such as materials processing, particle manipulation, etc.

  17. Touch-free, gesture-based control of medical devices and software based on the leap motion controller.

    Science.gov (United States)

    Mauser, Stanislas; Burgert, Oliver

    2014-01-01

    There are several intra-operative use cases which require the surgeon to interact with medical devices. We used the Leap Motion Controller as input device and implemented two use-cases: 2D-Interaction (e.g. advancing EPR data) and selection of a value (e.g. room illumination brightness). The gesture detection was successful and we mapped its output to several devices and systems.

  18. Home-based wrinkle reduction using a novel handheld multisource phase-controlled radiofrequency device.

    Science.gov (United States)

    Shemer, Avner; Levy, Hanna; Sadick, Neil S; Harth, Yoram; Dorizas, Andrew S

    2014-11-01

    In the last decade, energy-based aesthetic treatments, using light, radiofrequency (RF), and ultrasound, have gained scientific acceptance as safe and efficacious for non-invasive treatment for aesthetic skin disorders. The phase-controlled multisource radiofrequency technology (3DEEP™), which is based on the simultaneous use of multiple RF generators, was proven to allow significant pigment-independent dermal heating without pain or the need of epidermal cooling. This study was performed in order to evaluate the efficacy and safety of a new handheld device delivering multisource radiofrequency to the skin for wrinkle reduction and skin tightening in the home setting. A total of 69 participants (age 54.3 years ± 8.09; age range 37-72 years) were enrolled in the study after meeting all inclusion/exclusion criteria (100%) and providing informed consent. Participants were provided with the tested device together with a user manual and treatment diary, to perform independent treatments at home for 4 weeks. The tested device, (Newa™, EndyMed Medical, Cesarea, Israel) emits 12 W of 1Mhz, RF energy through six electrodes arranged in a linear fashion. Independent control of RF polarity through each one of the 6 electrodes allows significant reduction of energy flow through the epidermis with increased dermal penetration. Participants were instructed to perform at least 5 treatments a week, for one month. Four follow-up visits were scheduled (once a week) during the period of independent treatments at home, following 4 weeks of home treatments, 1 month follow-up visit (1 month after treatment end) and at 3 months follow-up (3 months following treatment end). Analysis of pre-and post treatment images was conducted by three uninvolved physicians experienced with the Fitzpatrick Wrinkle and Elastosis Scale. Fitzpatrick Wrinkle and Elastosis score of each time point (4 weeks following home use treatments; 1 month follow-up, 3 months follow-up) was compared to baseline

  19. Broadband working-waveband-tunable polarization converter based on anisotropic metasurface

    Science.gov (United States)

    Lin, Yu; Wang, Lei; Gao, Jun; Lu, Yichao; Jiang, Suhua; Zeng, Wei

    2017-03-01

    We experimentally and theoretically demonstrate an ultrathin, broadband, and highly efficient metamaterial-based polarization converter with a metasurface/insulator/metal (MIM) configuration. In such a system, the resonance undergoes a transition from a vertical Fabry-Pérot type to a transverse type as the spacer thickness decreases. By changing the spacer thickness from 1 to 15 mm, the working waveband of this device could be tuned from 10.9-12.9 to 6-8 GHz without compromising the polarization conversion efficiency. Equivalent circuit theory and the transfer matrix method are used for demonstrating the physical mechanism of our device.

  20. Remote device control and monitor system for the LHD deuterium experiments

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, Hideya, E-mail: nakanisi@nifs.ac.jp [National Institute for Fusion Science (NIFS), Toki, Gifu 509-5292 (Japan); Dept. Fusion Science, SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292 (Japan); Ohsuna, Masaki; Ito, Tatsuki; Nonomura, Miki; Imazu, Setsuo; Emoto, Masahiko; Iwata, Chie; Yoshida, Masanobu; Yokota, Mitsuhiro; Maeno, Hiroya; Aoyagi, Miwa; Ogawa, Hideki; Nakamura, Osamu; Morita, Yoshitaka; Inoue, Tomoyuki; Watanabe, Kiyomasa [National Institute for Fusion Science (NIFS), Toki, Gifu 509-5292 (Japan); Ida, Katsumi; Ishiguro, Seiji; Kaneko, Osamu [National Institute for Fusion Science (NIFS), Toki, Gifu 509-5292 (Japan); Dept. Fusion Science, SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292 (Japan)

    2016-11-15

    Highlights: • Device remote control will be significant for the LHD deuterium experiments. • A central management GUI to control the power distribution for devices. • For safety, power management is separated from operational commanding. • Wi-Fi was tested and found to be not reliable with fusion plasmas. - Abstract: Upon beginning the LHD deuterium experiment, the opportunity for maintenance work in the torus hall will be conspicuously reduced such that all instruments must be controlled remotely. The LHD data acquisition (DAQ) and archiving system have been using about 110 DAQ front-end, and the DAQ central control and monitor system has been implemented for their remote management. This system is based on the “multi-agent” model whose communication protocol has been unified. Since DAQ front-end electronics would suffer from the “single-event effect” (SEE) of D-D neutrons, software-based remote operation might become ineffective, and then securely intercepting or recycling the electrical power of the device would be indispensable for recovering from a non-responding fault condition. In this study, a centralized control and monitor system has been developed for a number of power distribution units (PDUs). This system adopts the plug-in structure in which the plug-in modules can absorb the differences among the commercial products of numerous vendors. The combination of the above-mentioned functionalities has led to realizing the flexible and highly reliable remote control infrastructure for the plasma diagnostics and the device management in LHD.

  1. Design technique for all-dielectric non-polarizing beam splitter plate

    Science.gov (United States)

    Rizea, A.

    2012-03-01

    There are many situations when, for the proper working, an opto-electronic device requiring optical components does not change the polarization state of light after a reflection, splitting or filtering. In this paper, a design for a non-polarizing beam splitter plate is proposed. Based on certain optical properties of homogeneous dielectric materials we will establish a reliable thin film package formula, excellent for the start of optimization to obtain a 20-nm bandwidth non-polarizing beam splitter.

  2. Polarization controlled deep sub-wavelength periodic features written by femtosecond laser on nanodiamond thin film surface

    Energy Technology Data Exchange (ETDEWEB)

    Kumar Kuntumalla, Mohan; Srikanth, Vadali V. S. S., E-mail: vvsssse@uohyd.ernet.in [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Rajamudili, Kuladeep; Rao Desai, Narayana [School of Physics, University of Hyderabad, Hyderabad 500046 (India)

    2014-04-21

    Deep sub-wavelength (Λ/λ = ∼0.22) periodic features are induced uniformly on a nanodiamond (ND) thin film surface using femtosecond (fs) laser irradiation (pulse duration = ∼110 fs and central wavelength of ∼800 nm). The topography of the surface features is controlled by the laser polarization. Orientation of features is perpendicular to laser polarization. Periodicity (spatial periodicity of < λ/4) of the surface features is less than the laser wavelength. This work gives an experimental proof of polarization controlled surface plasmon-fs laser coupling mechanism prompting the interaction between fs laser and solid matter (here ND thin film) which in turn is resulting in the periodic surface features. Scanning electron microscopy in conjunction with micro Raman scattering, X-ray diffraction, and atomic force microscopy are carried out to extract surface morphology and phase information of the laser irradiated regions. This work demonstrates an easy and efficient surface fabrication technique.

  3. Motorized CPM/CAM physiotherapy device with sliding-mode Fuzzy Neural Network control loop.

    Science.gov (United States)

    Ho, Hung-Jung; Chen, Tien-Chi

    2009-11-01

    Continuous passive motion (CPM) and controllable active motion (CAM) physiotherapy devices promote rehabilitation of damaged joints. This paper presents a computerized CPM/CAM system that obviates the need for mechanical resistance devices such as springs. The system is controlled by a computer which performs sliding-mode Fuzzy Neural Network (FNN) calculations online. CAM-type resistance force is generated by the active performance of an electric motor which is controlled so as to oppose the motion of the patient's leg. A force sensor under the patient's foot on the device pedal provides data for feedback in a sliding-mode FNN control loop built around the motor. Via an active impedance control feedback system, the controller drives the motor to behave similarly to a damped spring by generating and controlling the amplitude and direction of the pedal force in relation to the patient's leg. Experiments demonstrate the high sensitivity and speed of the device. The PC-based feedback nature of the control loop means that sophisticated auto-adaptable CPM/CAM custom-designed physiotherapy becomes possible. The computer base also allows extensive data recording, data analysis and network-connected remote patient monitoring.

  4. Highly stable polarization independent Mach-Zehnder interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Mičuda, Michal, E-mail: micuda@optics.upol.cz; Doláková, Ester; Straka, Ivo; Miková, Martina; Dušek, Miloslav; Fiurášek, Jaromír; Ježek, Miroslav, E-mail: jezek@optics.upol.cz [Department of Optics, Faculty of Science, Palacký University, 17. listopadu 1192/12, 77146 Olomouc (Czech Republic)

    2014-08-15

    We experimentally demonstrate optical Mach-Zehnder interferometer utilizing displaced Sagnac configuration to enhance its phase stability. The interferometer with footprint of 27×40 cm offers individually accessible paths and shows phase deviation less than 0.4° during a 250 s long measurement. The phase drift, evaluated by means of Allan deviation, stays below 3° or 7 nm for 1.5 h without any active stabilization. The polarization insensitive design is verified by measuring interference visibility as a function of input polarization. For both interferometer's output ports and all tested polarization states the visibility stays above 93%. The discrepancy in visibility for horizontal and vertical polarization about 3.5% is caused mainly by undesired polarization dependence of splitting ratio of the beam splitter used. The presented interferometer device is suitable for quantum-information and other sensitive applications where active stabilization is complicated and common-mode interferometer is not an option as both the interferometer arms have to be accessible individually.

  5. Harmonic Mitigation Using a Polarized Ramp-time Current-Controlled Inverter

    Directory of Open Access Journals (Sweden)

    Lawrence J. Borle

    2010-12-01

    Full Text Available This paper describes the implementation of a shunt active power filter for a three-phase four-wire system to compensate for power quality problems generated by mixed non-linear loads, which are a combination of harmonic, reactive and unbalanced components. The filter is a three-phase current-controlled voltage source inverter (CC-VSI with a filter inductor at the AC output and a DC-bus capacitor. The CC-VSI is operated to directly control the grid current to be sinusoidal and in phase with the grid voltage without sensing the load currents. The switching is controlled using polarized ramp-time current control, which is based on the concept of zero average current error (ZACE with a fixed switching frequency. The laboratory experiment results indicate that the filter is able to mitigate predominantly the harmonics, as well as the reactive power, so that the grid currents are sinusoidal, in phase with the grid voltages and symmetrical although the grid voltage contains harmonics.

  6. Diacylglycerol Kinases: Shaping Diacylglycerol and Phosphatidic Acid Gradients to Control Cell Polarity

    Directory of Open Access Journals (Sweden)

    Gianluca Baldanzi

    2016-11-01

    Full Text Available Diacylglycerol kinases (DGKs terminate diacylglycerol (DAG signaling and promote phosphatidic acid (PA production. Isoform specific regulation of DGKs activity and localization allows DGKs to shape the DAG and PA gradients. The capacity of DGKs to constrain the areas of DAG signaling is exemplified by their role in defining the contact interface between T cells and antigen presenting cells: the immune synapse. Upon T cell receptor engagement, both DGK α and ζ metabolize DAG at the immune synapse thus constraining DAG signaling. Interestingly, their activity and localization are not fully redundant because DGKζ activity metabolizes the bulk of DAG in the cell, whereas DGKα limits the DAG signaling area localizing specifically at the periphery of the immune synapse.When DGKs terminate DAG signaling, the local PA production defines a new signaling domain, where PA recruits and activates a second wave of effector proteins. The best-characterized example is the role of DGKs in protrusion elongation and cell migration. Indeed, upon growth factor stimulation, several DGK isoforms, such as α, ζ, and γ, are recruited and activated at the plasma membrane. Here, local PA production controls cell migration by finely modulating cytoskeletal remodeling and integrin recycling. Interestingly, DGK-produced PA also controls the localization and activity of key players in cell polarity such as aPKC, Par3, and integrin β1. Thus, T cell polarization and directional migration may be just two instances of the general contribution of DGKs to the definition of cell polarity by local specification of membrane identity signaling.

  7. Selective control of vortex polarities by microwave field in two robustly synchronized spin-torque nano-oscillators

    Science.gov (United States)

    Li, Yi; de Milly, Xavier; Klein, Olivier; Cros, Vincent; Grollier, Julie; de Loubens, Grégoire

    2018-01-01

    Manipulating operation states of coupled spin-torque nano-oscillators (STNOs), including their synchronization, is essential for applications such as complex oscillator networks. In this work, we experimentally demonstrate selective control of two coupled vortex STNOs through microwave-assisted switching of their vortex core polarities. First, the two oscillators are shown to synchronize due to the dipolar interaction in a broad frequency range tuned by an external biasing field. Coherent output is demonstrated along with strong linewidth reduction. Then, we show individual vortex polarity control of each oscillator, which leads to synchronization/desynchronization due to accompanied frequency shift. Our methods can be easily extended to multiple-element coupled oscillator networks.

  8. Recycling temperature elevation device and temperature control method for control rod driving system

    International Nuclear Information System (INIS)

    Okamura, Hajime.

    1996-01-01

    The present invention concerns a device for and a method of controlling a recycling temperature control device for control rod drives (CRD) of a nuclear power plant, which can prevent occurrence of cavitation and keep the amount of cooling water to be transferred to a water source transfer pipeline thereby improving maintenanciability, operationability and reliability. Namely, a supply pipeline supplies cooling water required for the control rod drives from a water source. A CRD pump elevates the pressure of the cooling water. A recycling pipeline is branched from the downstream of the CRD pump of the supply pipeline and connected to the supply pipeline at the upstream of the CRD pump. A first pressure element and a restricting valve disposed at the upstream thereof are connected to the upstream of the CRD pump and the water source transfer pipeline. The water source transfer pipeline is branched from the recycling pipeline and connected to the water source. A second pressure element is disposed to a recycling pipeline at the downstream of the branched point from the water source transfer pipeline. (I.S.)

  9. Creating a systems engineering approach for the manual on uniform traffic control devices.

    Science.gov (United States)

    2011-03-01

    The Manual on Uniform Traffic Control Devices (MUTCD) provides basic principles for use of traffic : control devices (TCD). However, most TCDs are not explicitly required, and the decision to use a given : TCD in a given situation is typically made b...

  10. Electromagnetic analysis of locking device for SMART control element drive mechanism

    International Nuclear Information System (INIS)

    Heo, H.; Kim, J. I.; Kim, J. H.; Kim, Y. W.; Park, J. S.

    1998-01-01

    A numerical electromagnetic analysis was performed for the control rod locking device which is installed in the control element drive mechanism of integral reactor, SMART. A plunger model for the electromagnetic analysis of the locking device was developed and theoretical bases for the model were established. Design parameters related to plunger pushing force were identified, and the optimum design point was determined by analyzing the trend of the plunger pushing force with finite element method

  11. Robust Control of Wide Bandgap Power Electronics Device Enabled Smart Grid

    Science.gov (United States)

    Yao, Tong

    In recent years, wide bandgap (WBG) devices enable power converters with higher power density and higher efficiency. On the other hand, smart grid technologies are getting mature due to new battery technology and computer technology. In the near future, the two technologies will form the next generation of smart grid enabled by WBG devices. This dissertation deals with two applications: silicon carbide (SiC) device used for medium voltage level interface (7.2 kV to 240 V) and gallium nitride (GaN) device used for low voltage level interface (240 V/120 V). A 20 kW solid state transformer (SST) is designed with 6 kHz switching frequency SiC rectifier. Then three robust control design methods are proposed for each of its smart grid operation modes. In grid connected mode, a new LCL filter design method is proposed considering grid voltage THD, grid current THD and current regulation loop robust stability with respect to the grid impedance change. In grid islanded mode, micro synthesis method combined with variable structure control is used to design a robust controller for grid voltage regulation. For grid emergency mode, multivariable controller designed using Hinfinity synthesis method is proposed for accurate power sharing. Controller-hardware-in-the-loop (CHIL) testbed considering 7-SST system is setup with Real Time Digital Simulator (RTDS). The real TMS320F28335 DSP and Spartan 6 FPGA control board is used to interface a switching model SST in RTDS. And the proposed control methods are tested. For low voltage level application, a 3.3 kW smart grid hardware is built with 3 GaN inverters. The inverters are designed with the GaN device characterized using the proposed multi-function double pulse tester. The inverter is controlled by onboard TMS320F28379D dual core DSP with 200 kHz sampling frequency. Each inverter is tested to process 2.2 kW power with overall efficiency of 96.5 % at room temperature. The smart grid monitor system and fault interrupt devices (FID

  12. Evaluation of the leap motion controller as a new contact-free pointing device.

    Science.gov (United States)

    Bachmann, Daniel; Weichert, Frank; Rinkenauer, Gerhard

    2014-12-24

    This paper presents a Fitts' law-based analysis of the user's performance in selection tasks with the Leap Motion Controller compared with a standard mouse device. The Leap Motion Controller (LMC) is a new contact-free input system for gesture-based human-computer interaction with declared sub-millimeter accuracy. Up to this point, there has hardly been any systematic evaluation of this new system available. With an error rate of 7.8% for the LMC and 2.8% for the mouse device, movement times twice as large as for a mouse device and high overall effort ratings, the Leap Motion Controller's performance as an input device for everyday generic computer pointing tasks is rather limited, at least with regard to the selection recognition provided by the LMC.

  13. High-damage-threshold static laser beam shaping using optically patterned liquid-crystal devices.

    Science.gov (United States)

    Dorrer, C; Wei, S K-H; Leung, P; Vargas, M; Wegman, K; Boulé, J; Zhao, Z; Marshall, K L; Chen, S H

    2011-10-15

    Beam shaping of coherent laser beams is demonstrated using liquid crystal (LC) cells with optically patterned pixels. The twist angle of a nematic LC is locally set to either 0 or 90° by an alignment layer prepared via exposure to polarized UV light. The two distinct pixel types induce either no polarization rotation or a 90° polarization rotation, respectively, on a linearly polarized optical field. An LC device placed between polarizers functions as a binary transmission beam shaper with a highly improved damage threshold compared to metal beam shapers. Using a coumarin-based photoalignment layer, various devices have been fabricated and tested, with a measured single-shot nanosecond damage threshold higher than 30 J/cm2.

  14. A Wii-controlled safety device for electric chainsaws

    Directory of Open Access Journals (Sweden)

    R. Gubiani

    2013-09-01

    Full Text Available Forestry continues to represent one of the most hazardous economic sectors of human activity, and historically, the operation of chainsaws has mainly been restricted to professional lumberjacks. In recent years, because of low cost, chainsaws have become popular among unprofessionals, e.g. for cutting firewood and trimming trees. Serious or lethal lesions due to the use of chainsaws or electric chainsaws are often observed by traumatologists or forensic pathologists. Such serious accidents often occur during occupational activities and are essentially due to kickback or uncorrected use of the tool, or when the operator falls down losing the control of the implement. A new device in order to stop a cutting chain was developed and adapted to an electric chainsaw. The device is based on a Wiimote controller (Nintendo™, including two accelerometers and two gyroscopes for detecting rotation and inclination. A Bluetooth wireless technology is used to transfer data to a portable computer. The data collected about linear and angular acceleration are filtered by an algorithm, based on the Euclid norm, capable to distinguishing between normal movements and dangerous chainsaw movements. The result show a good answer to device and when happen a dangerous situation an alarm signal is sent back to the implement in order to stop the cutting chain. The device show a correct behavior in tested dangerous situations and is envisaged to extend to combustion engine chainsaws, as well as to other portable equipment used in agriculture and forestry operations and for this objectives were patented.

  15. The Hippo pathway controls border cell migration through distinct mechanisms in outer border cells and polar cells of the Drosophila ovary.

    Science.gov (United States)

    Lin, Tzu-Huai; Yeh, Tsung-Han; Wang, Tsu-Wei; Yu, Jenn-Yah

    2014-11-01

    The Hippo pathway is a key signaling cascade in controlling organ size. The core components of this pathway are two kinases, Hippo (Hpo) and Warts (Wts), and a transcriptional coactivator, Yorkie (Yki). Yes-associated protein (YAP, a Yki homolog in mammals) promotes epithelial-mesenchymal transition and cell migration in vitro. Here, we use border cells in the Drosophila ovary as a model to study Hippo pathway functions in cell migration in vivo. During oogenesis, polar cells secrete Unpaired (Upd), which activates JAK/STAT signaling of neighboring cells and specifies them into outer border cells. The outer border cells form a cluster with polar cells and undergo migration. We find that hpo and wts are required for migration of the border cell cluster. In outer border cells, overexpression of hpo disrupts polarization of the actin cytoskeleton and attenuates migration. In polar cells, knockdown of hpo and wts or overexpression of yki impairs border cell induction and disrupts migration. These manipulations in polar cells reduce JAK/STAT activity in outer border cells. Expression of upd-lacZ is increased and decreased in yki and hpo mutant polar cells, respectively. Furthermore, forced expression of upd in polar cells rescues defects of border cell induction and migration caused by wts knockdown. These results suggest that Yki negatively regulates border cell induction by inhibiting JAK/STAT signaling. Together, our data elucidate two distinct mechanisms of the Hippo pathway in controlling border cell migration: (1) in outer border cells, it regulates polarized distribution of the actin cytoskeleton; (2) in polar cells, it regulates upd expression to control border cell induction and migration. Copyright © 2014 by the Genetics Society of America.

  16. Design and simulation of a novel circularly polarized antenna with polarization reconfigurable characteristics

    Directory of Open Access Journals (Sweden)

    Zhang Hai

    2016-01-01

    Full Text Available A novel circularly polarized antenna with polarization reconfigurable characteristics was designed using co-simulation of Ansoft HFSS and Designer software. It consists of a dual-polarized antenna and phase switching network which act as the feed network for the dual-polarized antenna. The phase switching network was designed based on a Wilkinson power divider, where the output port was connected with SPDT to form a switching network. By controlling the SPDT state-off / on, the phase difference of the two ports could be alternated, which generated the orthogonal modes between the two ports of dual-polarized antenna. So that Left-hand circular polarization (LHCP and Right-hand circular polarization (RHCP could be achieved. The simulation shown that reflection coefficient was less than -12 dB and the axial ratio was below 3 dB between 1.8 GHz and 2.4 GHz with polarization reconfigurable characteristics.

  17. Broadband Wireless Data Acquisition and Control Device, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Mobitrum is proposing to develop a broadband wireless device for real-time data acquisition and monitoring applicable to the field instrumentation and control...

  18. Symplectic models for general insertion devices

    International Nuclear Information System (INIS)

    Wu, Y.; Forest, E.; Robin, D. S.; Nishimura, H.; Wolski, A.; Litvinenko, V. N.

    2001-01-01

    A variety of insertion devices (IDs), wigglers and undulators, linearly or elliptically polarized,are widely used as high brightness radiation sources at the modern light source rings. Long and high-field wigglers have also been proposed as the main source of radiation damping at next generation damping rings. As a result, it becomes increasingly important to understand the impact of IDs on the charged particle dynamics in the storage ring. In this paper, we report our recent development of a general explicit symplectic model for IDs with the paraxial ray approximation. High-order explicit symplectic integrators are developed to study real-world insertion devices with a number of wiggler harmonics and arbitrary polarizations

  19. Into the development of a model to assess beam shaping and polarization control effects on laser cutting

    Science.gov (United States)

    Rodrigues, Gonçalo C.; Duflou, Joost R.

    2018-02-01

    This paper offers an in-depth look into beam shaping and polarization control as two of the most promising techniques for improving industrial laser cutting of metal sheets. An assessment model is developed for the study of such effects. It is built upon several modifications to models as available in literature in order to evaluate the potential of a wide range of considered concepts. This includes different kinds of beam shaping (achieved by extra-cavity optical elements or asymmetric diode staking) and polarization control techniques (linear, cross, radial, azimuthal). A fully mathematical description and solution procedure are provided. Three case studies for direct diode lasers follow, containing both experimental data and parametric studies. In the first case study, linear polarization is analyzed for any given angle between the cutting direction and the electrical field. In the second case several polarization strategies are compared for similar cut conditions, evaluating, for example, the minimum number of spatial divisions of a segmented polarized laser beam to achieve a target performance. A novel strategy, based on a 12-division linear-to-radial polarization converter with an axis misalignment and capable of improving cutting efficiency with more than 60%, is proposed. The last case study reveals different insights in beam shaping techniques, with an example of a beam shape optimization path for a 30% improvement in cutting efficiency. The proposed techniques are not limited to this type of laser source, neither is the model dedicated to these specific case studies. Limitations of the model and opportunities are further discussed.

  20. First polarization-engineered compressively strained AlInGaN barrier enhancement-mode MISHFET

    International Nuclear Information System (INIS)

    Hahn, Herwig; Reuters, Ben; Wille, Ada; Ketteniss, Nico; Kalisch, Holger; Vescan, Andrei; Benkhelifa, Fouad; Ambacher, Oliver

    2012-01-01

    One current focus of research is the realization of GaN-based enhancement-mode devices. A novel approach for the realization of enhancement-mode behaviour is the utilization of polarization matching between the barrier and the GaN buffer. Yet, the utilization of a quaternary barrier combining polarization engineering together with a large conduction band offset has not been demonstrated so far. Here, epitaxially grown, compressively strained AlInGaN is applied as a nearly polarization-matched barrier layer on GaN resulting in enhancement-mode operation. The insulated-gate devices are fabricated gate-first with Al 2 O 3 as gate dielectric. Passivated metal insulator semiconductor heterostructure field effect transistors yielded threshold voltages (V th ) of up to +1 V. The devices withstand negative and positive gate-biased stress and a positive V th is maintained even after long-time negative bias stress. (paper)

  1. Leap Motion Device Used to Control a Real Anthropomorphic Gripper

    Directory of Open Access Journals (Sweden)

    Ionel Staretu

    2016-06-01

    Full Text Available This paper presents for the first time the use of the Leap Motion device to control an anthropomorphic gripper with five fingers. First, a description of the Leap Motion device is presented, highlighting its main functional characteristics, followed by testing of its use for capturing the movements of a human hand's fingers in different configurations. Next, the HandCommander soft module and the Interface Controller application are described. The HandCommander is a software module created to facilitate interaction between a human hand and the GraspIT virtual environment, and the Interface Controller application is required to send motion data to the virtual environment and to test the communication protocol. For the test, a prototype of an anthropomorphic gripper with five fingers was made, including a proper hardware system of command and control, which is briefly presented in this paper. Following the creation of the prototype, the command system performance test was conducted under real conditions, evaluating the recognition efficiency of the objects to be gripped and the efficiency of the command and control strategies for the gripping process. The gripping test is exemplified by the gripping of an object, such as a screw spanner. It was found that the command system, both in terms of capturing human hand gestures with the Leap Motion device and effective object gripping, is operational. Suggestive figures are presented as examples.

  2. Three-dimensional imaging through turbid media based on polarization-difference liquid-crystal microlens array

    Science.gov (United States)

    Xin, Zhaowei; Wei, Dong; Li, Dapeng; Xie, Xingwang; Chen, Mingce; Zhang, Xinyu; Wang, Haiwei; Xie, Changsheng

    2018-02-01

    In this paper, a polarization difference liquid-crystal microlens array (PD-LCMLA) for three dimensional imaging application through turbid media is fabricated and demonstrated. This device is composed of a twisted nematic liquidcrystal cell (TNLCC), a polarizer and a liquid-crystal microlens array. The polarizer is sandwiched between the TNLCC and LCMLA to help the polarization difference system achieving the orthogonal polarization raw images. The prototyped camera for polarization difference imaging has been constructed by integrating the PD-LCMLA with an image sensor. The orthogonally polarized light-field images are recorded by switching the working state of the TNLCC. Here, by using a special microstructure in conjunction with the polarization-difference algorithm, we demonstrate that the three-dimensional information in the scattering media can be retrieved from the polarization-difference imaging system with an electrically tunable PD-LCMLA. We further investigate the system's potential function based on the flexible microstructure. The microstructure provides a wide operation range in the manipulation of incident beams and also emerges multiple operation modes for imaging applications, such as conventional planar imaging, polarization imaging mode, and polarization-difference imaging mode. Since the PD-LCMLA demonstrates a very low power consumption, multiple imaging modes and simple manufacturing, this kind of device presents a potential to be used in many other optical and electro-optical systems.

  3. Embedded Control System for Smart Walking Assistance Device.

    Science.gov (United States)

    Bosnak, Matevz; Skrjanc, Igor

    2017-03-01

    This paper presents the design and implementation of a unique control system for a smart hoist, a therapeutic device that is used in rehabilitation of walking. The control system features a unique human-machine interface that allows the human to intuitively control the system just by moving or rotating its body. The paper contains an overview of the complete system, including the design and implementation of custom sensors, dc servo motor controllers, communication interfaces and embedded-system based central control system. The prototype of the complete system was tested by conducting a 6-runs experiment on 11 subjects and results are showing that the proposed control system interface is indeed intuitive and simple to adopt by the user.

  4. Electric polarization switching in an atomically thin binary rock salt structure

    Science.gov (United States)

    Martinez-Castro, Jose; Piantek, Marten; Schubert, Sonja; Persson, Mats; Serrate, David; Hirjibehedin, Cyrus F.

    2018-01-01

    Inducing and controlling electric dipoles is hindered in the ultrathin limit by the finite screening length of surface charges at metal-insulator junctions1-3, although this effect can be circumvented by specially designed interfaces4. Heterostructures of insulating materials hold great promise, as confirmed by perovskite oxide superlattices with compositional substitution to artificially break the structural inversion symmetry5-8. Bringing this concept to the ultrathin limit would substantially broaden the range of materials and functionalities that could be exploited in novel nanoscale device designs. Here, we report that non-zero electric polarization can be induced and reversed in a hysteretic manner in bilayers made of ultrathin insulators whose electric polarization cannot be switched individually. In particular, we explore the interface between ionic rock salt alkali halides such as NaCl or KBr and polar insulating Cu2N terminating bulk copper. The strong compositional asymmetry between the polar Cu2N and the vacuum gap breaks inversion symmetry in the alkali halide layer, inducing out-of-plane dipoles that are stabilized in one orientation (self-poling). The dipole orientation can be reversed by a critical electric field, producing sharp switching of the tunnel current passing through the junction.

  5. Defect Characterization, Imaging, and Control in Wide-Bandgap Semiconductors and Devices

    Science.gov (United States)

    Brillson, L. J.; Foster, G. M.; Cox, J.; Ruane, W. T.; Jarjour, A. B.; Gao, H.; von Wenckstern, H.; Grundmann, M.; Wang, B.; Look, D. C.; Hyland, A.; Allen, M. W.

    2018-03-01

    Wide-bandgap semiconductors are now leading the way to new physical phenomena and device applications at nanoscale dimensions. The impact of defects on the electronic properties of these materials increases as their size decreases, motivating new techniques to characterize and begin to control these electronic states. Leading these advances have been the semiconductors ZnO, GaN, and related materials. This paper highlights the importance of native point defects in these semiconductors and describes how a complement of spatially localized surface science and spectroscopy techniques in three dimensions can characterize, image, and begin to control these electronic states at the nanoscale. A combination of characterization techniques including depth-resolved cathodoluminescence spectroscopy, surface photovoltage spectroscopy, and hyperspectral imaging can describe the nature and distribution of defects at interfaces at both bulk and nanoscale surfaces, their metal interfaces, and inside nanostructures themselves. These features as well as temperature and mechanical strain inside wide-bandgap device structures at the nanoscale can be measured even while these devices are operating. These advanced capabilities enable several new directions for describing defects at the nanoscale, showing how they contribute to device degradation, and guiding growth processes to control them.

  6. Spin Coulomb Dragging Inhibition of Spin-Polarized Electric Current Injecting into Organic Semiconductors

    International Nuclear Information System (INIS)

    Jun-Qing, Zhao; Shi-Zhu, Qiao; Zhen-Feng, Jia; Ning-Yu, Zhang; Yan-Ju, Ji; Yan-Tao, Pang; Ying, Chen; Gang, Fu

    2008-01-01

    We introduce a one-dimensional spin injection structure comprising a ferromagnetic metal and a nondegenerate organic semiconductor to model electric current polarizations. With this model we analyse spin Coulomb dragging (SCD) effects on the polarization under various electric fields, interface and conductivity conditions. The results show that the SCD inhibits the current polarization. Thus the SCD inhibition should be well considered for accurate evaluation of current polarization in the design of organic spin devices

  7. Semi-polar GaN heteroepitaxy an high index Si-surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ravash, Roghaiyeh; Blaesing, Juergen; Hempel, Thomas; Dadgar, Armin; Christen, Juergen; Krost, Alois [Otto-von-Guericke-University Magdeburg, FNW/IEP/AHE, Magdeburg (Germany)

    2011-07-01

    Due to the lack of GaN homosubstrates, the growth of GaN-based devices is usually performed on heterosubstrates as sapphire or SiC. These substrates are either insulating or expensive, and both unavailable in large diameters. Meanwhile, silicon can meet the requirements for a low price and thermally well conducting substrate and also enabling the integration of optoelectronic devices with Si-based electronics. Up to now, the good matching of hexagonal GaN with the three-fold symmetry of Si(111) greatly promotes the c-axis orientated growth of GaN on this surface plane. A large spontaneous and piezoelectric polarization oriented along the c-axis exists in such hexagonal structure leading to low efficiencies for thick quantum wells. The attention to the growth of non-polar or semi-polar GaN based epitaxial structures has been increased recently because of reducing the effect of the polarization fields in these growth directions. Therefore we studied semi-polar GaN epilayers grown by metalorganic vapor phase epitaxy on silicon substrates with different orientations from Si(211) to Si(711). We observed that AlN seeding layer growth time play a significant role in obtaining the different GaN texture.

  8. Device for rearranging control rods of experimental reactors

    International Nuclear Information System (INIS)

    Louda, J.

    1975-01-01

    The invention claims a means for the adjustment of control rods in experimental reactors with a continuously variable pitch of the fuel element spacer. The proposed device permits obtaining maximum variability in the physical modelling of nuclear power reactor cores in experimental reactors. (F.M.)

  9. High-Efficiency Dielectric Metasurfaces for Polarization-Dependent Terahertz Wavefront Manipulation

    KAUST Repository

    Zhang, Huifang

    2017-11-30

    Recently, metasurfaces made up of dielectric structures have drawn enormous attentions in the optical and infrared regimes due to their high efficiency and designing freedom in manipulating light propagation. Such advantages can also be introduced to terahertz frequencies where efficient functional devices are still lacking. Here, polarization-dependent all-silicon terahertz dielectric metasurfaces are proposed and experimentally demonstrated. The metasurfaces are composed of anisotropic rectangular-shaped silicon pillars on silicon substrate. Each metasurface holds dual different functions depending on the incident polarizations. Furthermore, to suppress the reflection loss and multireflection effect in practical applications, a high-performance polarization-independent antireflection silicon pillar array is also proposed, which can be patterned at the other side of the silicon substrate. Such all-silicon dielectric metasurfaces are easy to fabricate and can be very promising in developing next-generation efficient, compact, and low-cost terahertz functional devices.

  10. Method and device for controlling reactor power

    International Nuclear Information System (INIS)

    Oohashi, Masahisa; Masuda, Hiroyuki.

    1982-01-01

    Purpose: To enable load following-up operation of a reactor adapted to perform power conditioning by the control of the liquid poison density in the core and by the control rods. Constitution: In a case where the reactor power is repeatedly changed in a reactor having a liquid poison density control device and control rods, the time period for the power control is divided depending on the magnitude of the change with time in the reactivity and the optimum values are set for the injection and removal amount of the liquid poison within the divided period. Then, most parts of the control required for the power change are alloted to the liquid poison that gives no effect on the power distribution while minimizing the movement of the control rods, whereby the power change in the reactor as in the case of the load following-up operation can be practiced with ease. (Kawakami, Y.)

  11. Local gate control in carbon nanotube quantum devices

    Science.gov (United States)

    Biercuk, Michael Jordan

    This thesis presents transport measurements of carbon nanotube electronic devices operated in the quantum regime. Nanotubes are contacted by source and drain electrodes, and multiple lithographically-patterned electrostatic gates are aligned to each device. Transport measurements of device conductance or current as a function of local gate voltages reveal that local gates couple primarily to the proximal section of the nanotube, hence providing spatially localized control over carrier density along the nanotube length. Further, using several different techniques we are able to produce local depletion regions along the length of a tube. This phenomenon is explored in detail for different contact metals to the nanotube. We utilize local gating techniques to study multiple quantum dots in carbon nanotubes produced both by naturally occurring defects, and by the controlled application of voltages to depletion gates. We study double quantum dots in detail, where transport measurements reveal honeycomb charge stability diagrams. We extract values of energy-level spacings, capacitances, and interaction energies for this system, and demonstrate independent control over all relevant tunneling rates. We report rf-reflectometry measurements of gate-defined carbon nanotube quantum dots with integrated charge sensors. Aluminum rf-SETs are electrostatically coupled to carbon nanotube devices and detect single electron charging phenomena in the Coulomb blockade regime. Simultaneous correlated measurements of single electron charging are made using reflected rf power from the nanotube itself and from the rf-SET on microsecond time scales. We map charge stability diagrams for the nanotube quantum dot via charge sensing, observing Coulomb charging diamonds beyond the first order. Conductance measurements of carbon nanotubes containing gated local depletion regions exhibit plateaus as a function of gate voltage, spaced by approximately 1e2/h, the quantum of conductance for a single

  12. Review of microfluidic cell culture devices for the control of gaseous microenvironments in vitro

    Science.gov (United States)

    Wu, H.-M.; Lee, T.-A.; Ko, P.-L.; Chiang, H.-J.; Peng, C.-C.; Tung, Y.-C.

    2018-04-01

    Gaseous microenvironments play important roles in various biological activities in vivo. However, it is challenging to precisely control gaseous microenvironments in vitro for cell culture due to the high diffusivity nature of gases. In recent years, microfluidics has paved the way for the development of new types of cell culture devices capable of manipulating cellular microenvironments, and provides a powerful tool for in vitro cell studies. This paper reviews recent developments of microfluidic cell culture devices for the control of gaseous microenvironments, and discusses the advantages and limitations of current devices. We conclude with suggestions for the future development of microfluidic cell culture devices for the control of gaseous microenvironments.

  13. A osteogenesis distraction device enabling control of vertical direction for syndromic craniosynostosis.

    Science.gov (United States)

    Kobayashi, Shinji; Fukawa, Toshihiko; Hirakawa, Takashi; Maegawa, Jiro

    2014-02-01

    We have developed a hybrid facial osteogenesis distraction system that combines the advantages of external and internal distraction devices to enable control of both the distraction distance and vector. However, when the advanced maxilla has excessive clockwise rotation and shifts more downward vertically than planned, it might be impossible to pull it up to correct it. We invented devices attached to external distraction systems that can control the vertical vector of distraction to resolve this problem. The purpose of this article is to describe the result of utilizing the distraction system for syndromic craniosynostosis. In addition to a previously reported hybrid facial distraction system, the devices for controlling the vertical direction of the advanced maxilla were attached to the external distraction device. The vertical direction of the advanced maxilla can be controlled by adjustment of the spindle units. This system was used for 2 patients with Crouzon and Apert syndrome. The system enabled control of the vertical distance, with no complications during the procedures. As a result, the maxilla could be advanced into the planned position including overcorrection without excessive clockwise rotation of distraction. Our system can alter the cases and bring them into the planned position, by controlling the vertical vector of distraction. We believe that this system might be effective in infants with syndromic craniosynostosis as it involves 2 osteotomies and horizontal and vertical direction of elongation can be controlled.

  14. Fault-Tolerant Control of ANPC Three-Level Inverter Based on Order-Reduction Optimal Control Strategy under Multi-Device Open-Circuit Fault.

    Science.gov (United States)

    Xu, Shi-Zhou; Wang, Chun-Jie; Lin, Fang-Li; Li, Shi-Xiang

    2017-10-31

    The multi-device open-circuit fault is a common fault of ANPC (Active Neutral-Point Clamped) three-level inverter and effect the operation stability of the whole system. To improve the operation stability, this paper summarized the main solutions currently firstly and analyzed all the possible states of multi-device open-circuit fault. Secondly, an order-reduction optimal control strategy was proposed under multi-device open-circuit fault to realize fault-tolerant control based on the topology and control requirement of ANPC three-level inverter and operation stability. This control strategy can solve the faults with different operation states, and can works in order-reduction state under specific open-circuit faults with specific combined devices, which sacrifices the control quality to obtain the stability priority control. Finally, the simulation and experiment proved the effectiveness of the proposed strategy.

  15. Development of Hand Grip Assistive Device Control System for Old People through Electromyography (EMG Signal Acquisitions

    Directory of Open Access Journals (Sweden)

    Khamis Herman

    2017-01-01

    Full Text Available The hand grip assistive device is a glove to assist old people who suffer from hand weakness in their daily life activities. The device earlier control system only use simple on and off switch. This required old people to use both hand to activate the device. The new control system of the hand grip assistive device was developed to allow single hand operation for old people. New control system take advantages of electromyography (EMG and flex sensor which was implemented to the device. It was programmed into active and semi-active mode operation. EMG sensors were placed on the forearm to capture EMG signal of Flexor Digitorum Profundus muscle to activate the device. Flex sensor was used to indicate the finger position and placed on top of the finger. The signal from both sensors then used to control the device. The new control system allowed single hand operation and designed to prevent user from over depended on the device by activating it through moving their fingers.

  16. Fabrication and Characterization of GaN-Based Two Terminal Devices for Liquid Sensing

    Energy Technology Data Exchange (ETDEWEB)

    Jeat, Wang Soo; Abidin, Mastura Shafinaz Zainal; Hashim, Abdul Manaf; Rahman, Shaharin Fadzli Abd; Sharifabad, Maneea Eizadi; Mustafa, Farahiyah; Rahman, Abdul Rahim Abdul [Material Innovations and Nanoelectronics Research Group, Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Qindeel, Rabia [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Omar, Nurul Afzan, E-mail: manaf@fke.utm.my [Telekom Research and Development, TM Innovation Centre, 63000 Cyberjaya (Malaysia)

    2011-02-15

    Gallium Nitride (GaN) based materials are highly suitable for liquid-phase sensor applications due to their chemical stability and high internal piezoelectric polarization. The sensitivity of GaN surfaces in aqueous solutions and polar liquids has been investigated. For this purpose, two terminal devices fabricated on bulk Si doped-GaN structures and undoped-AlGaN/GaN heterostructures with unpassivated open area are used to measure the responses to the changes of the H{sup +} concentration in aqueous solutions and the dipole moment in polar liquids. The I-V characteristics show that the devices are able to distinguish the variations of pH. It is observed that the drain current decreases linearly with pH for both device structures. Evaluating the sensitivity in aqueous solutions at V{sub DS} = 2V, a quite large current change is obtained for both structures. For the response to polar liquids, it is also found that the drain current decreases with the dipole moments. The results indicate that both devices are capable of distinguishing molecules with different dipole moments.

  17. Electromagnetic analysis of locking device for SMART control element drive mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Hyung; Kim, J. I.; Kim, J. H. [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-09-01

    A numerical electromagnetic analysis was performed for the control rod locking device which is installed in the control element drive mechanism of integral reactor, SMART. A plunger model for the electromagnetic analysis of the locking device was developed and theoretical bases for the model were established. Design parameters related to plunger pushing force were identified, and the optimum design point was determined by analysing the trend of the plunger pushing force with finite element method. 8 refs., 22 figs., 2 tabs. (Author)

  18. Versatile spin-polarized electron source

    Science.gov (United States)

    Jozwiak, Chris; Park, Cheol -Hwan; Gotlieb, Kenneth; Louie, Steven G.; Hussain, Zahid; Lanzara, Alessandra

    2015-09-22

    One or more embodiments relate generally to the field of photoelectron spin and, more specifically, to a method and system for creating a controllable spin-polarized electron source. One preferred embodiment of the invention generally comprises: method for creating a controllable spin-polarized electron source comprising the following steps: providing one or more materials, the one or more materials having at least one surface and a material layer adjacent to said surface, wherein said surface comprises highly spin-polarized surface electrons, wherein the direction and spin of the surface electrons are locked together; providing at least one incident light capable of stimulating photoemission of said surface electrons; wherein the photon polarization of said incident light is tunable; and inducing photoemission of the surface electron states.

  19. General multimode polarization splitter design in uniaxial media

    Science.gov (United States)

    Teixeira, Poliane A.; Silva, Daniely G.; Gabrielli, Lucas H.; Spadoti, Danilo H.; Junqueira, Mateus A. F. C.

    2018-03-01

    Quasiconformal transformation optics is used to design two-dimensional polarization beam splitters. The resulting media present inhomogeneous uniaxial permittivity and nonmagnetic response. The compact devices are theoretically designed and investigated for symmetrical and asymmetrical geometries, with footprint of 64 and 110 μm2, respectively. The polarization splitter performance is evaluated for the fundamental mode and third mode, exhibiting an insertion loss closer to 0 dB and extinction ratio above 40 dB over a broad wavelength range.

  20. Remote control of nanoscale devices

    Science.gov (United States)

    Högberg, Björn

    2018-01-01

    Processes that occur at the nanometer scale have a tremendous impact on our daily lives. Sophisticated evolved nanomachines operate in each of our cells; we also, as a society, increasingly rely on synthetic nanodevices for communication and computation. Scientists are still only beginning to master this scale, but, recently, DNA nanotechnology (1)—in particular, DNA origami (2)—has emerged as a powerful tool to build structures precise enough to help us do so. On page 296 of this issue, Kopperger et al. (3) show that they are now also able to control the motion of a DNA origami device from the outside by applying electric fields.

  1. Surface EMG and intra-socket force measurement to control a prosthetic device

    Science.gov (United States)

    Sanford, Joe; Patterson, Rita; Popa, Dan

    2015-06-01

    Surface electromyography (SEMG) has been shown to be a robust and reliable interaction method allowing for basic control of powered prosthetic devices. Research has shown a marked decrease in EMG-classification efficiency throughout activities of daily life due to socket shift and movement and fatigue as well as changes in degree of fit of the socket throughout the subject's lifetime. Users with the most severe levels of amputation require the most complex devices with the greatest number of degrees of freedom. Controlling complex dexterous devices with limited available inputs requires the addition of sensing and interaction modalities. However, the larger the amputation severity, the fewer viable SEMG sites are available as control inputs. Previous work reported the use of intra-socket pressure, as measured during wrist flexion and extension, and has shown that it is possible to control a powered prosthetic device with pressure sensors. In this paper, we present data correlations of SEMG data with intra-socket pressure data. Surface EMG sensors and force sensors were housed within a simulated prosthetic cuff fit to a healthy-limbed subject. EMG and intra-socket force data was collected from inside the cuff as a subject performed pre-defined grip motions with their dominant hand. Data fusion algorithms were explored and allowed a subject to use both intra-socket pressure and SEMG data as control inputs for a powered prosthetic device. This additional input modality allows for an improvement in input classification as well as information regarding socket fit through out activities of daily life.

  2. Potentiodynamic polarization assays on magnetic materials for new medical micro-devices

    Energy Technology Data Exchange (ETDEWEB)

    Pouponneau, P. [Ecole Polytechnique de Montreal, PQ (Canada). Nanorobotics Lab; Ecole Polytechnique de Montreal, PQ (Canada). Biomedical Engineering Inst., Laboratory for the Innovation and Analysis of Bioperformance; Savadogo, O.; Napporn, T. [Ecole Polytechnique de Montreal, Montreal, PQ (Canada). Laboratoire de nouveaux materiaux pour l' energie et l' electrochimie; Yahia, L' H. [Ecole Polytechnique de Montreal, PQ (Canada). Biomedical Engineering Inst., Laboratory for the Innovation and Analysis of Bioperformance; Martel, S. [Ecole Polytechnique de Montreal, PQ (Canada). Nanorobotics Lab

    2008-07-01

    This study investigated the corrosion behaviour of a terbium (Tb0.27Dy0.73Fe1.95) alloy and single crystal nickel (Ni-Mn-Ga) alloy smart magnetic materials (SMM), and Vacoflux 17 and Permendur iron-cobalt alloys. Previous studies have shown that the materials demonstrate a high potential for use in wireless medical microdevices controlled by magnetic fields. However, the Tb0.27Dy0.73Fe1.95 alloy has poor corrosion properties due to its high corrosion potential and corrosion current. Corrosion behaviour was investigated using potentiodynamic polarization measurements and scanning electron microscopy. The study showed that the surface of the alloy was impaired by cracks and holes. The single crystal Ni-Mn Ga alloy demonstrated higher corrosion resistance. The SMM were then embedded into a bio-compatible matrix to form composite with the Vacoflux 17 and Permendur alloys. The study showed that while the Vacoflux 17 surface was degraded by cracks and pits, the Permendur surface was uniformly corroded without pitting. The uniform corrosion was attributed to the formation of a stable passive layer. 4 refs., 3 figs.

  3. Development of Hand Grip Assistive Device Control System for Old People through Electromyography (EMG) Signal Acquisitions

    OpenAIRE

    Khamis Herman; Mohamaddan Shahrol; Komeda Takashi; Alias Aidil Azli; Tanjong Shirley Jonathan; Julai Norhuzaimin; Hashim Nurul ‘Izzati

    2017-01-01

    The hand grip assistive device is a glove to assist old people who suffer from hand weakness in their daily life activities. The device earlier control system only use simple on and off switch. This required old people to use both hand to activate the device. The new control system of the hand grip assistive device was developed to allow single hand operation for old people. New control system take advantages of electromyography (EMG) and flex sensor which was implemented to the device. It wa...

  4. Polarization of very cold neutron using a permanent magnet quadrupole

    Energy Technology Data Exchange (ETDEWEB)

    Yoshioka, Tamaki, E-mail: tyosioka@post.kek.j [High Energy Accelerator Research Organization, Ibaraki 305-0801 (Japan); Mishima, Kenji; Ino, Takashi; Taketani, Kaoru; Muto, Suguru; Morishima, Takahiro; Shimizu, Hirohiko M. [High Energy Accelerator Research Organization, Ibaraki 305-0801 (Japan); Oku, Takayuki; Suzuki, Junichi; Shinohara, Takenao; Sakai, Kenji [Japan Atomic Energy Agency, Ibaraki 319-1195 (Japan); Sato, Hiromi; Hirota, Katsuya; Otake, Yoshie [RIKEN, Saitama 351-0198 (Japan); Kitaguchi, Masaaki; Hino, Masahiro [Research Reactor Institute, Kyoto University, Osaka 590-0494 (Japan); Seki, Yoshichika [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Iwashita, Yoshihisa; Yamada, Masako [Institute for Chemical Research, Kyoto University, Kyoto 611-0011 (Japan); Ichikawa, Masahiro [Department of Physics, The University of Tokyo, Tokyo 113-0033 (Japan)

    2011-04-01

    For the future fundamental physics experiments by using cold neutrons, we are developing a device which can measure the neutron polarization degree by accuracy significantly below 10{sup -3}. A quadrupole magnet is one of the promising candidate to measure the neutron polarization degree by such extremely high precision. We have performed a polarization experiment by using the quadrupole magnets at the Very Cold Neutron (VCN) port of the PF-2 in the Institute Laue-Langevin (ILL). As a result, we obtained the polarization degree P with very high accuracy P=0.9994{+-}0.0001(stat.){+-}0.0003(syst.), which meet our requirement significantly.

  5. Spin-controlled ultrafast vertical-cavity surface-emitting lasers

    Science.gov (United States)

    Höpfner, Henning; Lindemann, Markus; Gerhardt, Nils C.; Hofmann, Martin R.

    2014-05-01

    Spin-controlled semiconductor lasers are highly attractive spintronic devices providing characteristics superior to their conventional purely charge-based counterparts. In particular, spin-controlled vertical-cavity surface emitting lasers (spin-VCSELs) promise to offer lower thresholds, enhanced emission intensity, spin amplification, full polarization control, chirp control and ultrafast dynamics. Most important, the ability to control and modulate the polarization state of the laser emission with extraordinarily high frequencies is very attractive for many applications like broadband optical communication and ultrafast optical switches. We present a novel concept for ultrafast spin-VCSELs which has the potential to overcome the conventional speed limitation for directly modulated lasers by the relaxation oscillation frequency and to reach modulation frequencies significantly above 100 GHz. The concept is based on the coupled spin-photon dynamics in birefringent micro-cavity lasers. By injecting spin-polarized carriers in the VCSEL, oscillations of the coupled spin-photon system can by induced which lead to oscillations of the polarization state of the laser emission. These oscillations are decoupled from conventional relaxation oscillations of the carrier-photon system and can be much faster than these. Utilizing these polarization oscillations is thus a very promising approach to develop ultrafast spin-VCSELs for high speed optical data communication in the near future. Different aspects of the spin and polarization dynamics, its connection to birefringence and bistability in the cavity, controlled switching of the oscillations, and the limitations of this novel approach will be analysed theoretically and experimentally for spin-polarized VCSELs at room temperature.

  6. Re-centering variable friction device for vibration control of structures subjected to near-field earthquakes

    Science.gov (United States)

    Ozbulut, Osman E.; Hurlebaus, Stefan

    2011-11-01

    This paper proposes a re-centering variable friction device (RVFD) for control of civil structures subjected to near-field earthquakes. The proposed hybrid device has two sub-components. The first sub-component of this hybrid device consists of shape memory alloy (SMA) wires that exhibit a unique hysteretic behavior and full recovery following post-transformation deformations. The second sub-component of the hybrid device consists of variable friction damper (VFD) that can be intelligently controlled for adaptive semi-active behavior via modulation of its voltage level. In general, installed SMA devices have the ability to re-center structures at the end of the motion and VFDs can increase the energy dissipation capacity of structures. The full realization of these devices into a singular, hybrid form which complements the performance of each device is investigated in this study. A neuro-fuzzy model is used to capture rate- and temperature-dependent nonlinear behavior of the SMA components of the hybrid device. An optimal fuzzy logic controller (FLC) is developed to modulate voltage level of VFDs for favorable performance in a RVFD hybrid application. To obtain optimal controllers for concurrent mitigation of displacement and acceleration responses, tuning of governing fuzzy rules is conducted by a multi-objective heuristic optimization. Then, numerical simulation of a multi-story building is conducted to evaluate the performance of the hybrid device. Results show that a re-centering variable friction device modulated with a fuzzy logic control strategy can effectively reduce structural deformations without increasing acceleration response during near-field earthquakes.

  7. Evaluation of the polarization properties of a Philips-type prism for the construction of imaging polarimeters

    Science.gov (United States)

    Fernandez-Borda, R.; Waluschka, E.; Pellicori, S.; Martins, J. V.; Ramos-Izquierdo, L.; Cieslak, J. D.; Thompson, P.

    2009-08-01

    The design and construction of wide FOV imaging polarimeters for use in atmospheric remote sensing requires significant attention to the prevention of artificial polarization induced by the optical elements. Surface, coatings, and angles of incidence throughout the system must be carefully designed in order to minimize these artifacts because the remaining instrumental bias polarization is the main factor which drives the final polarimetric accuracy of the system. In this work, we present a detailed evaluation and analysis to explore the possibility of retrieving the initial polarization state of the light traveling through a generic system that has inherent instrumental polarization. Our case is a wide FOV lens and a splitter device. In particular, we chose as splitter device a Philips-type prism, because it is able to divide the signal in 3 independent channels that could be simultaneously analyze to retrieve the three first elements of the Stoke vector (in atmospheric applications the elliptical polarization can be neglected [1]). The Philips-type configuration is a versatile, compact and robust prism device that is typically used in three color camera systems. It has been used in some commercial polarimetric cameras which do not claim high accuracy polarization measurements [2]. With this work, we address the accuracy of our polarization inversion and measurements made with the Philips-type beam divider.

  8. Calculated Performance Of The Variable-Polarization Undulator Upgrade To The Daresbury SRS Soft X-Ray Undulator Beamline

    International Nuclear Information System (INIS)

    Roper, Mark D.; Bird, Daniel T.

    2004-01-01

    The soft x-ray beamline 5U1 on the Daresbury Laboratory SRS currently uses a planar undulator, producing linearly polarized radiation in the range 100 to 1000 eV. The undulator is soon to be replaced by a variable-polarization device of the Apple II design. The aim is to produce circularly polarized light in the energy range 265 to 1000 eV, covering the K-edges of C, N and O, and the first row transition element L-edges. This will greatly enhance the provision of circularly polarized soft-x-rays on the SRS and open up new opportunities for experimenters. The device will also produce linear polarization with a selectable angle of polarization with respect to the orbit plane, which is currently unavailable on the SRS. In order to provide the coverage over this energy range, we are exploiting the relatively large emittance of the SRS to allow us to use the second and third harmonics even in circular polarization mode. This paper presents the expected beamline output in various polarization modes and the predicted degree of polarization

  9. Use of advanced programmable logic controllers to monitor and control the Elmo Bumpy Torus-proof-of-principle device

    International Nuclear Information System (INIS)

    Boyd, B.A.

    1983-01-01

    The Elmo Bumpy Torus - Proof-of-Principle (EBT-P) device is designed with an instrumentation and control system based upon the use of an advanced Programmable Logic Controller (PLC). The modern PLC incorporates many advanced programming features not available in earlier PLC's intended for application to conventional relay logic replacement. The additional power and flexibility of these modern PLC's is especially applicable to an experimental device such as EBT-P which is made up of several complex interrelated subsystems whose operational characteristics will be evolving throughout the lifetime of the device. The rationale for the selection of advanced PLC's for EBT-P and the approach taken to design of the software developed to control EBT-P are the topics addressed in this paper

  10. Calibration of the Chemcatcher passive sampler for monitoring selected polar and semi-polar pesticides in surface water

    International Nuclear Information System (INIS)

    Gunold, Roman; Schaefer, Ralf Bernhard; Paschke, Albrecht; Schueuermann, Gerrit; Liess, Matthias

    2008-01-01

    Passive sampling is a powerful method for continuous pollution monitoring, but calibration experiments are still needed to generate sampling rates in order to estimate water concentrations for polar compounds. We calibrated the Chemcatcher device with an uncovered SDB-XC Empore disk as receiving phase for 12 polar and semi-polar pesticides in aquatic environments in flow-through tank experiments at two water flow velocities (0.135 m/s and 0.4 m/s). In the 14-day period of exposure the uptake of test substances in the sampler remained linear, and all derived sampling rates R s were in the range of 0.1 to 0.5 L/day. By additionally monitoring the release of two preloaded polar pesticides from the SDB-XC disks over time, very high variation in release kinetics was found, which calls into question the applicability of performance reference compounds. Our study expands the applicability of the Chemcatcher for monitoring trace concentrations of pesticides with frequent occurrence in water. - We calibrated the Chemcatcher passive sampler for current-use polar pesticides in surface waters, allowing its application in future monitoring studies

  11. Quality Control Method for a Micro-Nano-Channel Microfabricated Device

    Science.gov (United States)

    Grattoni, Alessandro; Ferrari, Mauro; Li, Xuewu

    2012-01-01

    A variety of silicon-fabricated devices is used in medical applications such as drug and cell delivery, and DNA and protein separation and analysis. When a fluidic device inlet is connected to a compressed gas reservoir, and the outlet is at a lower pressure, a gas flow occurs through the membrane toward the outside. The method relies on the measurement of the gas pressure over the elapsed time inside the upstream and downstream environments. By knowing the volume of the upstream reservoir, the gas flow rate through the membrane over the pressure drop can be calculated. This quality control method consists of measuring the gas flow through a device and comparing the results with a standard curve, which can be obtained by testing standard devices. Standard devices can be selected through a variety of techniques, both destructive and nondestructive, such as SEM, AFM, and standard particle filtration.

  12. High spin-polarization in ultrathin Co2MnSi/CoPd multilayers

    International Nuclear Information System (INIS)

    Galanakis, I.

    2015-01-01

    Half-metallic Co 2 MnSi finds a broad spectrum of applications in spintronic devices either in the form of thin films or as spacer in multilayers. Using state-of-the-art ab-initio electronic structure calculations we exploit the electronic and magnetic properties of ultrathin Co 2 MnSi/CoPd multilayers. We show that these heterostructures combine high values of spin-polarization at the Co 2 MnSi spacer with the perpendicular magnetic anisotropy of binary compounds such as CoPd. Thus they could find application in spintronic/magnetoelectronic devices. - Highlights: • Ab-initio study of ultrathin Co 2 MnSi/CoPd multilayers. • Large values of spin-polarization at the Fermi are retained. • Route for novel spintronic/magnetoelectronic devices

  13. Humidity control device in a reactor container

    International Nuclear Information System (INIS)

    Aizawa, Motohiro; Igarashi, Hiroo; Osumi, Katsumi; Kimura, Takashi.

    1986-01-01

    Purpose: To provide a device capable of maintaining the inside of a container under high humidity circumstantial conditions causing less atmospheric corrosions, in order to prevent injuries due to atmospheric corrosions to smaller diameter stainless steel pipeways in the reactor container. Constitution: Stress corrosion cracks (SCC) to the smaller diameter stainless steel pipeways are caused dependent on the relative humidity and it is effective as the countermeasure against SCC to maintain the relative humidity at a low level less than 30 % or high level greater than 60 %. Based on the above findings, a humidity control device is disposed so as to maintain the relative humidity for the atmosphere within a reactor core on a higher humidity region. The device is adapted such that recycling gas in the dry-well coolant circuit is passed through an orifice to atomize the water introduced from feedwater pipe and introduce into a reactor core or such that the recycling gases in the dry-well cooling circuit are bubbled into water to remove chlorine gas in the reactor container gas thereby increasing the humidity in the reactor container. (Kamimura, M.)

  14. Nanoscale architectural tuning of parylene patch devices to control therapeutic release rates

    International Nuclear Information System (INIS)

    Pierstorff, Erik; Lam, Robert; Ho, Dean

    2008-01-01

    The advent of therapeutic functionalized implant coatings has significantly impacted the medical device field by enabling prolonged device functionality for enhanced patient treatment. Incorporation of drug release from a stable, biocompatible surface is instrumental in decreasing systemic application of toxic therapeutics and increasing the lifespan of implants by the incorporation of antibiotics and anti-inflammatories. In this study, we have developed a parylene C-based device for controlled release of Doxorubicin, an anti-cancer chemotherapy and definitive read-out for preserved drug functionality, and further characterized the parylene deposition condition-dependent tunability of drug release. Drug release is controlled by the deposition of a layer of 20-200 nm thick parylene over the drug layer. This places a porous layer above the Doxorubicin, limiting drug elution based on drug accessibility to solvent and the solvent used. An increase in the thickness of the porous top layer prolongs the elution of active drug from the device from, in the conditions tested, the order of 10 min to the order of 2 d in water and from the order of 10 min to no elution in PBS. Thus, the controlled release of an anti-cancer therapeutic has been achieved via scalably fabricated, parylene C-encapsulated drug delivery devices.

  15. Unidirectional cross polarization rotator with enhanced broadband transparency by cascading twisted nanobars

    International Nuclear Information System (INIS)

    Wang, Ying-Hua; Shao, Jian; Li, Jie; Zhu, Ming-Jie; Li, Jiaqi; Dong, Zheng-Gao

    2016-01-01

    We demonstrate the optical activity for linear polarization by twisting cascading multilayer nanobars, for which the x- (y-)polarized light is significantly transformed to a y- (x-)polarized one with enhanced transmittance in a unidirectional manner, and the bandwidth can be broadened by increasing the cascading number of layers. The polarization conversion rate reaches nearly 100% with a maximum cross-polarization transmission coefficient larger than 0.95. This phenomenon is attributed to the chiral structural arrangement and anisotropic resonance of nanobars, which consequently leads to different cross-polarization conversions between forward and backward incident lights, and thus the unidirectional transmission with an extinction ratio up to 10 3 . These characteristics show application potential in optical nano-devices. (paper)

  16. Tailoring polarization of electromagnetically induced transparency based on non-centrosymmetric metasurfaces

    Science.gov (United States)

    Li, Hai-ming; Xue, Feng

    2017-09-01

    In this manuscript, tailoring polarization of analogy of electromagnetically induced transparency (EIT-like) based on non-centrosymmetric metasurfaces has been numerically and experimentally demonstrated. The EIT-like metamaterial is composed of a rectangle ring and two cut wires. The rectangle ring and the cut wire are chosen as the bright mode and the quasi-dark mode, respectively. Under the incident electromagnetic wave excitation, a polarization insensitive EIT-like transmission window can be observed at specific polarization angles. Within the transmission window, the phase steeply changes, which leads to the large group index. Tailoring polarization of EIT-like metamaterial with large group index at specific polarization angles may have potential application in slow light devices.

  17. Cross section and linear polarization of tagged photons

    International Nuclear Information System (INIS)

    Asai, J.; Caplan, H.S.; Skopik, D.M.; DelBianco, W.; Maximon, L.C.

    1988-01-01

    Formulae for bremsstrahlung cross sections and polarizations are usually presented in coordinate systems not very suitable for application by experimental physicists to devices such as photon-tagging monochromators. In this paper the transformations between the different coordinate systems are presented, along with examples of the calculated cross sections and polarizations in a form convenient from the experimental standpoint. These examples also give the predicted characteristics of the photon tagger currently under construction at the Saskatchewan Accelerator Laboratory. (16 refs., 19 figs., tab.)

  18. Organic ferroelectric memory devices with inkjet-printed polymer electrodes on flexible substrates

    KAUST Repository

    Bhansali, Unnat Sampatraj

    2013-05-01

    Drop-on-demand piezoelectric inkjet-printing technique has been used to fabricate a functional cross-bar array of all-organic ferroelectric memory devices. The polymer-ferroelectric-polymer device consists of a ferroelectric copolymer P(VDF-TrFE) film sandwiched between inkjet-patterned, continuous, orthogonal lines of PEDOT:PSS polymer as the bottom and top electrodes. These devices exhibit well-saturated hysteresis curves with a maximum remnant polarization (Pr) = 6.7 μC/cm2, coercive field (E c) = 55 MV/m and a peak capacitance density of 45 nF/cm2. Our polarization fatigue measurements show that these devices retain ∼100% and 45% of their initial Pr values after 103 and 10 5 stress cycles, respectively. The overall performance and polarization retention characteristics of these ferroelectric capacitors with inkjet-printed polymer electrodes are comparable to metal and spin-cast polymer electrodes suggesting their potential use in large-area flexible electronics. © 2013 Elsevier Ltd. All rights reserved.

  19. Control phase shift of spin-wave by spin-polarized current and its application in logic gates

    International Nuclear Information System (INIS)

    Chen, Xiangxu; Wang, Qi; Liao, Yulong; Tang, Xiaoli; Zhang, Huaiwu; Zhong, Zhiyong

    2015-01-01

    We proposed a new ways to control the phase shift of propagating spin waves by applying a local spin-polarized current on ferromagnetic stripe. Micromagnetic simulation showed that a phase shift of about π can be obtained by designing appropriate width and number of pinned magnetic layers. The ways can be adopted in a Mach-Zehnder-type interferometer structure to fulfill logic NOT gates based on spin waves. - Highlights: • Spin-wave phase shift can be controlled by a local spin-polarized current. • Spin-wave phase shift increased with the increasing of current density. • Spin-wave phase shift can reach about 0.3π at a particular current density. • The ways can be used in a Mach-Zehnder-type interferometer to fulfill logic gates

  20. Stability of polarization in organic ferroelectric metal-insulator-semiconductor (MIS) structures

    Energy Technology Data Exchange (ETDEWEB)

    Kalbitz, Rene; Fruebing, Peter; Gerhard, Reimund [Department of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Strasse 24-25, 14476, Potsdam (Germany); Taylor, Martin [School of Electronic Engineering, Bangor University, Dean Street, Bangor Gwynedd, LL57 1UT (United Kingdom)

    2011-07-01

    Ferroelectric field effect transistors (FeFETs) offer the prospect of an organic-based memory device. Since the charge transport in such devices is confined to the interface between the insulator and the semiconductor, the focus of the present study was on the investigation of this region. Capacitance-voltage (C-V) measurements of all-organic MIS devices with poly(vinylidenefluoride- trifluoroethylene) (P(VDF-TrFE)) as gate insulator and poly(3-hexylthiophene)(P3HT) as semiconductor were carried out. When the structure was driven into depletion, a positive flat-band voltage shift was observed arising from the change in polarization state of the ferroelectric insulator. When driven into accumulation, the polarization was reversed. It is shown that both polarization states are stable. However, negative charge trapped at the interface during the depletion cycle masks the negative shift in flat-band voltage expected during the sweep to accumulation voltages. Measurements on P(VDF-TrFE)/P3HT based FeFETs yield further evidence for fixed charges at the interface. Output characteristics suggest the injection of negative charges into the interface region when a depletion voltage is applied between source and gate contact.

  1. Observation of Fermi Arc Surface States Induced by Organic Memristive/Memcapacitive Devices with a Double-Helical Polarized Single-Wall Nanotube Membrane for Direct Chelating with Matrix Matelloproteinase-2

    Directory of Open Access Journals (Sweden)

    E. T. CHEN

    2017-07-01

    Full Text Available Matrix Matelloproteinase-2 (MMP-2 plays a key role in many diseases. A new type of dual-functioning device was developed for fast, direct ultrasensitive detection of MMP-2. We report a memristive/memcapacitive device with vertex double-helical polarized biomimetic protein nanotubules forming double membranes with potential gradient mimicking mitochondria’s inner double membrane has developed. We also report Fermi arcs with nodes on the surface of the nanostructured membrane was observed at the first time by using a 3D real-time - energy-current dynamic mapping method based on data obtained from the Cyclic Voltammetry (CV method. The memristive/memcapacitive device comprises a cross- linked organic polymer having single-wall cross-bar polarized nanotube self-assembling membrane (SAM on a gold chip, under an applied potential, a pair of vertex double- helical circular current flow induced the Fermi arcs states occurrence and these Fermi arcs promoted a direct chelating with zinc ions of the MMP-2 to become possible without any antibody, tracer, or reagent used at room temperature was accomplished. We observed the pair of Dirac Cones became alignment and strengthened with each other in the presence of MMP-2 compared without MMP-2. The MMP-2 can be detected with ag/mL level sensitivity and the value of Detection of Limits (DOL reached orders of magnitude lower than published reports with simplified procedures by a Chronoamperometry (CA method and a Double Step Chronopotentiometry (DSCPO method using NIST SRM 965A standard human serum, respectively. The results show a feasible application for developing the commercial fast and real-time MMP monitoring devices for various diseases.

  2. Rankine cycle condenser pressure control using an energy conversion device bypass valve

    Science.gov (United States)

    Ernst, Timothy C; Nelson, Christopher R; Zigan, James A

    2014-04-01

    The disclosure provides a waste heat recovery system and method in which pressure in a Rankine cycle (RC) system of the WHR system is regulated by diverting working fluid from entering an inlet of an energy conversion device of the RC system. In the system, an inlet of a controllable bypass valve is fluidly coupled to a working fluid path upstream of an energy conversion device of the RC system, and an outlet of the bypass valve is fluidly coupled to the working fluid path upstream of the condenser of the RC system such that working fluid passing through the bypass valve bypasses the energy conversion device and increases the pressure in a condenser. A controller determines the temperature and pressure of the working fluid and controls the bypass valve to regulate pressure in the condenser.

  3. Optics. Observation of optical polarization Möbius strips.

    Science.gov (United States)

    Bauer, Thomas; Banzer, Peter; Karimi, Ebrahim; Orlov, Sergej; Rubano, Andrea; Marrucci, Lorenzo; Santamato, Enrico; Boyd, Robert W; Leuchs, Gerd

    2015-02-27

    Möbius strips are three-dimensional geometrical structures, fascinating for their peculiar property of being surfaces with only one "side"—or, more technically, being "nonorientable" surfaces. Despite being easily realized artificially, the spontaneous emergence of these structures in nature is exceedingly rare. Here, we generate Möbius strips of optical polarization by tightly focusing the light beam emerging from a q-plate, a liquid crystal device that modifies the polarization of light in a space-variant manner. Using a recently developed method for the three-dimensional nanotomography of optical vector fields, we fully reconstruct the light polarization structure in the focal region, confirming the appearance of Möbius polarization structures. The preparation of such structured light modes may be important for complex light beam engineering and optical micro- and nanofabrication. Copyright © 2015, American Association for the Advancement of Science.

  4. Device for the nuclear reactor automatic start-up and power control

    International Nuclear Information System (INIS)

    Nikiforov, B.N.; Volkov, A.V.; Ogon'kov, A.I.

    1978-01-01

    A description and flowsheet of a reactor start-up and power-control automatic device containing no nonlinear elements with a relay characteristic are presented. The device consists of two independent channels for measuring the physical power and time (period) constant of the reactor. Requirements for the device are considered, based on the condition of a minimum permissible number of a servomechanism operations due to fluctuations of an input signal which appear because of the statistical nature of processes taking place in the reactor. It is noted that the threshold amplifier used in the device allows a considerable decrease of the reactor start-up time

  5. Gravity insensitive inventory control device for a two-phase flow system

    International Nuclear Information System (INIS)

    Bland, T.J.

    1987-01-01

    A liquid inventory control device is described for a flow system where the liquid changes phase to a vapor and back and a pitot pump separates vapor from liquid and pumps the liquid to a component of the flow system comprising: a liquid storage device for storing liquid under pressure, a tube positioned within the pitot pump and in open communication with the liquid storage device, and the tube having an opening positioned within the pitot pump at a location to establish a desired liquid level in the pitot pump and at which level the pressure at the pitot tube inlet will equal the liquid pressure at the liquid storage device

  6. Study of proton polarization in charge exchange process on optically oriented sodium atoms

    International Nuclear Information System (INIS)

    Zelenskij, A.N.; Kokhanovskij, S.A.

    1984-01-01

    Using high-power adjustable dye lasers for electron spin orientation in a charge-exchange target enables to significantly increase the proton polarization efficiency. A device is described that permits to avoid growth of the polarized proton beam emittance in a charge-exchange process in a strong magnetic field. The devise main feature is the use of an intensive source of neutral hydrogen atoms and the presence of a helium additional charge-exchange target which actualy is a proton ''source''. The helium charge-exchange cell is placed in the same magnetic field of a solenoid where a cell with oriented sodium is placed, a polarized electron being captured by a proton in the latter cell. In this case the beam at the solenoid inlet and outlet is in a neutral state; emittance growth related to the effect of end magnetic fields is not observed. The device after all prouduces polarized protons, their polarization degree is measured and the effect of various factors on polarization degree is studied. The description of the laser source and laser system is given. Measurement results have shown the beam intensity of neutral 7 keV atoms which passed through a polarizer to be 2 mA. The proton current doesn't depend. On the beeld fin the region of chrge exchange for the 8 kGs magnetic field. The degree of sodium polarization was 80% and polarized proton current approximately 70 μA at a temperature of the polarized sodium cell corresponding to the density of sodium vapar approximately 3x10 13 at/cm 2

  7. Lunar true polar wander inferred from polar hydrogen.

    Science.gov (United States)

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

    2016-03-24

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

  8. Polarization memory of white luminescence of Ag nanoclusters dispersed in glass host.

    Science.gov (United States)

    Kuznetsov, A S; Tikhomirov, V K; Moshchalkov, V V

    2012-09-10

    A mechanism for white luminescence of Ag nanoclusters dispersed in oxyfluoride glass host has been revealed by studying a temperature dependence of its polarization memory. The spectral dependence of the polarization memory indicates the presence of a variety of Ag nanoclusters, particularly emitting in the blue, green and red. Temperature activated intercluster energy transfer has been found responsible for white luminescence. The means for increasing luminescence quantum yield have been suggested. This efficient white luminescence may be used in highly demanded devices, such as luminescent lamps, displays, color phosphors for LEDs, photovoltaic devices based on down shifting of solar spectrum.

  9. Optimizing the construction of devices to control inaccesible surfaces - case study

    Science.gov (United States)

    Niţu, E. L.; Costea, A.; Iordache, M. D.; Rizea, A. D.; Babă, Al

    2017-10-01

    The modern concept for the evolution of manufacturing systems requires multi-criteria optimization of technological processes and equipments, prioritizing associated criteria according to their importance. Technological preparation of the manufacturing can be developed, depending on the volume of production, to the limit of favourable economical effects related to the recovery of the costs for the design and execution of the technological equipment. Devices, as subsystems of the technological system, in the general context of modernization and diversification of machines, tools, semi-finished products and drives, are made in a multitude of constructive variants, which in many cases do not allow their identification, study and improvement. This paper presents a case study in which the multi-criteria analysis of some structures, based on a general optimization method, of novelty character, is used in order to determine the optimal construction variant of a control device. The rational construction of the control device confirms that the optimization method and the proposed calculation methods are correct and determine a different system configuration, new features and functions, and a specific method of working to control inaccessible surfaces.

  10. Lattice-polarity-driven epitaxy of hexagonal semiconductor nanowires

    KAUST Repository

    Wang, Ping; Yuan, Ying; Zhao, Chao; Wang, Xinqiang; Zheng, Xiantong; Rong, Xin; Wang, Tao; Sheng, Bowen; Wang, Qingxiao; Zhang, Yongqiang; Bian, Lifeng; Yang, Xue-Lin; Xu, Fu-Jun; Qin, Zhixin; Li, Xin-Zheng; Zhang, Xixiang; Shen, Bo

    2015-01-01

    by first-principles density functional theory (DFT). The formation of diagonal pyramids for the N-polarity hexagonal NWs affords a novel way to locate quantum dot in the kink position, suggesting a new recipe for the fabrication of dot-based devices.

  11. Polarization recovery through scattering media.

    Science.gov (United States)

    de Aguiar, Hilton B; Gigan, Sylvain; Brasselet, Sophie

    2017-09-01

    The control and use of light polarization in optical sciences and engineering are widespread. Despite remarkable developments in polarization-resolved imaging for life sciences, their transposition to strongly scattering media is currently not possible, because of the inherent depolarization effects arising from multiple scattering. We show an unprecedented phenomenon that opens new possibilities for polarization-resolved microscopy in strongly scattering media: polarization recovery via broadband wavefront shaping. We demonstrate focusing and recovery of the original injected polarization state without using any polarizing optics at the detection. To enable molecular-level structural imaging, an arbitrary rotation of the input polarization does not degrade the quality of the focus. We further exploit the robustness of polarization recovery for structural imaging of biological tissues through scattering media. We retrieve molecular-level organization information of collagen fibers by polarization-resolved second harmonic generation, a topic of wide interest for diagnosis in biomedical optics. Ultimately, the observation of this new phenomenon paves the way for extending current polarization-based methods to strongly scattering environments.

  12. Reversing the polarity of a cochlear implant magnet after magnetic resonance imaging.

    Science.gov (United States)

    Jeon, Ju Hyun; Bae, Mi Ran; Chang, Jae Won; Choi, Jae Young

    2012-08-01

    The number of patients with cochlear implant (CI) has been rapidly increasing in recent years, and these patients show a growing need of examination by magnetic resonance imaging (MRI). However, the use of MRI on patients with CI is restricted by the internal magnet of the CI. Many studies have investigated the safety of performing 1.5T MRI on patients with CI, which is now being practiced in a clinical setting. We experienced a case in which the polarity of the cochlear implant magnet was reversed after the patient was examined using 1.5T MRI. The external device was attached to the internal device oppositely. We could not find displacement of the internal device, magnet, or electrode upon radiological evaluation. We came up with two possible mechanisms by which the polarity of the magnet reversed. The first possibility was that the magnetic field of MRI reversed the polarity of the magnet. The second was that the internal magnet was physically realigned while interacting with the MRI. We believe the second hypothesis to be more reliable. A removable magnet and a loose magnet boundary of a CI device may have allowed for physical reorientation of the internal magnet. Therefore, in order to avoid these complications, first, the internal magnet must not be aligned anti-parallel with the magnetic polarity of MRI. In the Siemens MRI, the vector of the magnetic field is downward, so implant site should be placed in facing upwards to minimize demagnetization. In the GE Medical Systems MRI, the vector of the magnetic field is upward, so the implant site should be placed facing downwards. Second, wearing of a commercial mold which is fixed to the internal device before performing MRI can be helpful. In addition, any removable internal magnets in a CI device should be removed before MRI, especially in the trunk. However, to ultimately solve this problem, the pocket of the internal magnet should be redesigned for safety. Copyright © 2011. Published by Elsevier Ireland Ltd.

  13. Electronic Devices for Controlling the Very High Voltage in the ALICE TPC Detector

    CERN Document Server

    Boccioli, Marco

    2007-01-01

    The Time Projection Chamber (TPC) is the core of the ALICE experiment at CERN. The TPC Very High Voltage project covers the development of the control system for the power supply that generates the 100kV necessary for the drift field in the TPC. This paper reports on the project progress, introducing the control system architecture from the electronics up to the control level. All the electronic devices will be described, highlighting their communication issues, and the challenges in integrating these devices in a PLC-based control system.

  14. Study to Improve Security for IoT Smart Device Controller: Drawbacks and Countermeasures

    Directory of Open Access Journals (Sweden)

    Xin Su

    2018-01-01

    Full Text Available Including mobile environment, conventional security mechanisms have been adapted to satisfy the needs of users. However, the device environment-IoT-based number of connected devices is quite different to the previous traditional desktop PC- or mobile-based environment. Based on the IoT, different kinds of smart and mobile devices are fully connected automatically via device controller, such as smartphone. Therefore, controller must be secure compared to conventional security mechanism. According to the existing security threats, these are quite different from the previous ones. Thus, the countermeasures applied should be changed. However, the smart device-based authentication techniques that have been proposed to date are not adequate in terms of usability and security. From the viewpoint of usability, the environment is based on mobility, and thus devices are designed and developed to enhance their owners’ efficiency. Thus, in all applications, there is a need to consider usability, even when the application is a security mechanism. Typically, mobility is emphasized over security. However, considering that the major characteristic of a device controller is deeply related to its owner’s private information, a security technique that is robust to all kinds of attacks is mandatory. In this paper, we focus on security. First, in terms of security achievement, we investigate and categorize conventional attacks and emerging issues and then analyze conventional and existing countermeasures, respectively. Finally, as countermeasure concepts, we propose several representative methods.

  15. Biomass fueled fluidized bed combustion: atmospheric emissions, emission control devices and environmental regulations

    International Nuclear Information System (INIS)

    Grass, S.W.; Jenkins, B.M.

    1994-01-01

    Fluidized bed combustors have become the technological choice for power generation from biomass fuels in California. Atmospheric emission data obtained during compliance tests are compared for five operating 18 to 32 MW fluidized bed combustion power plants. The discussion focuses on the impact of fuel properties and boiler design criteria on the emission of pollutants, the efficiency of pollution control devices, and regulations affecting atmospheric emissions. Stack NO x emission factors are shown not to vary substantially among the five plants which burn fuels with nitrogen concentrations between 0.3 and 1.1% dry weight. All facilities use at least one particular control device, but not all use limestone injection or other control techniques for sulfur and chlorine. The lack of control for chlorine suggests the potential for emission of toxic species due to favorable temperature conditions existing in the particulate control devices, particularly when burning fuels containing high concentrations of chlorine. (Author)

  16. Novel wideband microwave polarization network using a fully-reconfigurable photonic waveguide interleaver with a two-ring resonator-assisted asymmetric Mach-Zehnder structure.

    Science.gov (United States)

    Zhuang, Leimeng; Beeker, Willem; Leinse, Arne; Heideman, René; van Dijk, Paulus; Roeloffzen, Chris

    2013-02-11

    We propose and demonstrate a novel wideband microwave photonic polarization network for dual linear-polarized antennas. The polarization network is based on a waveguide-implemented fully-reconfigurable optical interleaver using a two-ring resonator-assisted asymmetric Mach-Zehnder structure. For microwave photonic signal processing, this structure is able to serve as a wideband 2 × 2 RF coupler with reconfigurable complex coefficients, and therefore can be used as a polarization network for wideband antennas. Such a device can equip the antennas with not only the polarization rotation capability for linear-polarization signals but also the capability to operate with and tune between two opposite circular polarizations. Operating together with a particular modulation scheme, the device is also able to serve for simultaneous feeding of dual-polarization signals. These photonic-implemented RF functionalities can be applied to wideband antenna systems to perform agile polarization manipulations and tracking operations. An example of such a interleaver has been realized in TriPleX waveguide technology, which was designed with a free spectral range of 20 GHz and a mask footprint of smaller than 1 × 1 cm. Using the realized device, the reconfigurable complex coefficients of the polarization network were demonstrated with a continuous bandwidth from 2 to 8 GHz and an in-band phase ripple of smaller than 5 degree. The waveguide structure of the device allows it to be further integrated with other functional building blocks of a photonic integrated circuit to realize on-chip, complex microwave photonic processors. Of particular interest, it can be included in an optical beamformer for phased array antennas, so that simultaneous wideband beam and polarization trackings can be achieved photonically. To our knowledge, this is the first-time on-chip demonstration of an integrated microwave photonic polarization network for dual linear-polarized antennas.

  17. Injection of Spin-Polarized Electrons into a AlGaN/GaN Device from an Electrochemical Cell: Evidence for an Extremely Long Spin Lifetime.

    Science.gov (United States)

    Kumar, Anup; Capua, Eyal; Fontanesi, Claudio; Carmieli, Raanan; Naaman, Ron

    2018-04-24

    Spin-polarized electrons are injected from an electrochemical cell through a chiral self-assembled organic monolayer into a AlGaN/GaN device in which a shallow two-dimensional electron gas (2DEG) layer is formed. The injection is monitored by a microwave signal that indicates a coherent spin lifetime that exceeds 10 ms at room temperature. The signal was found to be magnetic field independent; however, it depends on the current of the injected electrons, on the length of the chiral molecules, and on the existence of 2DEG.

  18. Polar transport in plants mediated by membrane transporters: focus on mechanisms of polar auxin transport.

    Science.gov (United States)

    Naramoto, Satoshi

    2017-12-01

    Directional cell-to-cell transport of functional molecules, called polar transport, enables plants to sense and respond to developmental and environmental signals. Transporters that localize to plasma membranes (PMs) in a polar manner are key components of these systems. PIN-FORMED (PIN) auxin efflux carriers, which are the most studied polar-localized PM proteins, are implicated in the polar transport of auxin that in turn regulates plant development and tropic growth. In this review, the regulatory mechanisms underlying polar localization of PINs, control of auxin efflux activity, and PIN abundance at PMs are considered. Up to date information on polar-localized nutrient transporters that regulate directional nutrient movement from soil into the root vasculature is also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Design of belt conveyor electric control device based on CC-link bus

    Science.gov (United States)

    Chen, Goufen; Zhan, Minhua; Li, Jiehua

    2016-01-01

    In view of problem of the existing coal mine belt conveyor is no field bus communication function, two levels belt conveyor electric control system design is proposed based on field bus. Two-stage belt conveyor electric control system consists of operation platform, PLC control unit, various sensors, alarm device and the water spraying device. The error protection is realized by PLC programming, made use of CC-Link bus technology, the data share and the cooperative control came true between host station and slave station. The real-time monitor was achieved by the touch screen program. Practical application shows that the system can ensure the coalmine production, and improve the automatic level of the coalmine transport equipment.

  20. Researching on Control Device of Prestressing Wire Reinforcement

    Science.gov (United States)

    Si, Jianhui; Guo, Yangbo; Liu, Maoshe

    2017-06-01

    This paper mainly introduces a device for controlling prestress and its related research methods, the advantage of this method is that the reinforcement process is easy to operate and control the prestress of wire rope accurately. The relationship between the stress and strain of the steel wire rope is monitored during the experiment, and the one - to - one relationship between the controllable position and the pretightening force of the steel wire rope is confirmed by the 5mm steel wire rope, and the results are analyzed theoretically by the measured elastic modulus. The results show that the method can effectively control the prestressing force, and the result provides a reference method for strengthening the concrete column with prestressed steel strand.