WorldWideScience

Sample records for optical faraday cup

  1. Optical Faraday Cup for Heavy Ion Beams

    Energy Technology Data Exchange (ETDEWEB)

    Bieniosek, Frank; Bieniosek, F.M.; Eylon, S.; Roy, P.K.; Yu, S.S.

    2007-06-25

    We have been using alumina scintillators for imaging beams in heavy-ion beam fusion experiments in 2 to 4 transverse dimensions [1]. The scintillator has a limited lifetime under bombardment by the heavy ion beams. As a possible replacement for the scintillator, we are studying the technique of imaging the beam on a gas cloud. A gas cloud for imaging the beam may be created on a solid hole plate placed in the path of the beam, or by a localized gas jet. It is possible to image the beam using certain fast-quenching optical lines that closely follow beam current density and are independent of gas density. We describe this technique and show preliminary experimental data. This approach has promise to be a new fast beam current diagnostic on a nanosecond time scale.

  2. Modified Faraday cup

    Science.gov (United States)

    Elmer, John W.; Teruya, Alan T.; O'Brien, Dennis W.

    1996-01-01

    A tomographic technique for measuring the current density distribution in electron beams using electron beam profile data acquired from a modified Faraday cup to create an image of the current density in high and low power beams. The modified Faraday cup includes a narrow slit and is rotated by a stepper motor and can be moved in the x, y and z directions. The beam is swept across the slit perpendicular thereto and controlled by deflection coils, and the slit rotated such that waveforms are taken every few degrees form 0.degree. to 360.degree. and the waveforms are recorded by a digitizing storage oscilloscope. Two-din-tensional and three-dimensional images of the current density distribution in the beam can be reconstructed by computer tomography from this information, providing quantitative information about the beam focus and alignment.

  3. Fast Faraday Cup With High Bandwidth

    Science.gov (United States)

    Deibele, Craig E [Knoxville, TN

    2006-03-14

    A circuit card stripline Fast Faraday cup quantitatively measures the picosecond time structure of a charged particle beam. The stripline configuration maintains signal integrity, and stitching of the stripline increases the bandwidth. A calibration procedure ensures the measurement of the absolute charge and time structure of the charged particle beam.

  4. Development and first experimental tests of Faraday cup array.

    Science.gov (United States)

    Prokůpek, J; Kaufman, J; Margarone, D; Krůs, M; Velyhan, A; Krása, J; Burris-Mog, T; Busold, S; Deppert, O; Cowan, T E; Korn, G

    2014-01-01

    A new type of Faraday cup, capable of detecting high energy charged particles produced in a high intensity laser-matter interaction environment, has recently been developed and demonstrated as a real-time detector based on the time-of-flight technique. An array of these Faraday cups was designed and constructed to cover different observation angles with respect to the target normal direction. Thus, it allows reconstruction of the spatial distribution of ion current density in the subcritical plasma region and the ability to visualise its time evolution through time-of-flight measurements, which cannot be achieved with standard laser optical interferometry. This is a unique method for two-dimensional visualisation of ion currents from laser-generated plasmas. A technical description of the new type of Faraday cup is introduced along with an ad hoc data analysis procedure. Experimental results obtained during campaigns at the Petawatt High-Energy Laser for Heavy Ion Experiments (GSI, Darmstadt) and at the Prague Asterix Laser System (AS CR) are presented. Advantages and limitations of the used diagnostic system are discussed.

  5. Miniature modified Faraday cup for micro electron beams

    Science.gov (United States)

    Teruya, Alan T.; Elmer, John W.; Palmer, Todd A.; Walton, Chris C.

    2008-05-27

    A micro beam Faraday cup assembly includes a refractory metal layer with an odd number of thin, radially positioned traces in this refractory metal layer. Some of the radially positioned traces are located at the edge of the micro modified Faraday cup body and some of the radially positioned traces are located in the central portion of the micro modified Faraday cup body. Each set of traces is connected to a separate data acquisition channel to form multiple independent diagnostic networks. The data obtained from the two diagnostic networks are combined and inputted into a computed tomography algorithm to reconstruct the beam shape, size, and power density distribution.

  6. Technology development for the Solar Probe Plus Faraday Cup

    Science.gov (United States)

    Freeman, Mark D.; Kasper, Justin; Case, Anthony W.; Daigneau, Peter; Gauron, Thomas; Bookbinder, Jay; Brodu, Étienne; Balat-Pichelin, Marianne; Wright, Kenneth

    2013-09-01

    The upcoming Solar Probe Plus (SPP) mission requires novel approaches for in-situ plasma instrument design. SPP's Solar Probe Cup (SPC) instrument will, as part of the Solar Wind Electrons, Alphas, and Protons (SWEAP) instrument suite, operate over an enormous range of temperatures, yet must still accurately measure currents below 1 pico-amp, and with modest power requirements. This paper discusses some of the key technology development aspects of the SPC, a Faraday Cup and one of the few instruments on SPP that is directly exposed to the solar disk, where at closest approach to the Sun (less than 10 solar radii (Rs) from the center of the Sun) the intensity is greater than 475 earth-suns. These challenges range from materials characterization at temperatures in excess of 1400°C to thermal modeling of the behavior of the materials and their interactions at these temperatures. We discuss the trades that have resulted in the material selection for the current design of the Faraday Cup. Specific challenges include the material selection and mechanical design of insulators, particularly for the high-voltage (up to 8 kV) grid and coaxial supply line, and thermo-optical techniques to minimize temperatures in the SPC, with the specific intent of demonstrating Technology Readiness Level 6 by the end of 2013.

  7. Faraday anomalous dispersion optical tuners

    Science.gov (United States)

    Wanninger, P.; Valdez, E. C.; Shay, T. M.

    1992-01-01

    Common methods for frequency stabilizing diode lasers systems employ gratings, etalons, optical electric double feedback, atomic resonance, and a Faraday cell with low magnetic field. Our method, the Faraday Anomalous Dispersion Optical Transmitter (FADOT) laser locking, is much simpler than other schemes. The FADOT uses commercial laser diodes with no antireflection coatings, an atomic Faraday cell with a single polarizer, and an output coupler to form a compound cavity. This method is vibration insensitive, thermal expansion effects are minimal, and the system has a frequency pull in range of 443.2 GHz (9A). Our technique is based on the Faraday anomalous dispersion optical filter. This method has potential applications in optical communication, remote sensing, and pumping laser excited optical filters. We present the first theoretical model for the FADOT and compare the calculations to our experimental results.

  8. Active Faraday optical frequency standard.

    Science.gov (United States)

    Zhuang, Wei; Chen, Jingbiao

    2014-11-01

    We propose the mechanism of an active Faraday optical clock, and experimentally demonstrate an active Faraday optical frequency standard based on narrow bandwidth Faraday atomic filter by the method of velocity-selective optical pumping of cesium vapor. The center frequency of the active Faraday optical frequency standard is determined by the cesium 6 (2)S(1/2) F=4 to 6 (2)P(3/2) F'=4 and 5 crossover transition line. The optical heterodyne beat between two similar independent setups shows that the frequency linewidth reaches 281(23) Hz, which is 1.9×10(4) times smaller than the natural linewidth of the cesium 852-nm transition line. The maximum emitted light power reaches 75 μW. The active Faraday optical frequency standard reported here has advantages of narrow linewidth and reduced cavity pulling, which can readily be extended to other atomic transition lines of alkali and alkaline-earth metal atoms trapped in optical lattices at magic wavelengths, making it useful for new generation of optical atomic clocks.

  9. Faraday cup with nanosecond response and adjustable impedance for fast electron beam characterization.

    Science.gov (United States)

    Hu, Jing; Rovey, Joshua L

    2011-07-01

    A movable Faraday cup design with simple structure and adjustable impedance is described in this work. This Faraday cup has external adjustable shunt resistance for self-biased measurement setup and 50 Ω characteristic impedance to match with 50 Ω standard BNC coaxial cable and vacuum feedthroughs for nanosecond-level pulse signal measurements. Adjustable shunt resistance allows self-biased measurements to be quickly acquired to determine the electron energy distribution function. The performance of the Faraday cup is validated by tests of response time and amplitude of output signal. When compared with a reference source, the percent difference of the Faraday cup signal fall time is less than 10% for fall times greater than 10 ns. The percent difference of the Faraday cup signal pulse width is below 6.7% for pulse widths greater than 10 ns. A pseudospark-generated electron beam is used to compare the amplitude of the Faraday cup signal with a calibrated F-70 commercial current transformer. The error of the Faraday cup output amplitude is below 10% for the 4-14 kV tested pseudospark voltages. The main benefit of this Faraday cup is demonstrated by adjusting the external shunt resistance and performing the self-biased method for obtaining the electron energy distribution function. Results from a 4 kV pseudospark discharge indicate a "double-humped" energy distribution.

  10. Performance enhancement study of an electrostatic Faraday cup detector

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, J.D. [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606-3390 (United States); Hodges, G.S. [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606-3390 (United States); Seely, D.G. [Department of Physics, Albion College, Albion, MI 49224 (United States); Moroz, N.A. [Department of Physics, Albion College, Albion, MI 49224 (United States); Kvale, T.J. [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606-3390 (United States)]. E-mail: tkvale@physics.utoledo.edu

    2005-01-01

    Faraday cups (FCs) have long been used to measure charged particle beam currents in experiments that seek to determine cross-sections in energetic particle collisions. The reliable operation of a FC as a detector depends on the ability of the device to recapture the electrons ejected when energetic particles strike its interior metal surfaces. We have conducted comparative performance studies of a traditional cylindrically-symmetric, electrostatic-based FC versus an alternative design in which the cylindrical symmetry is broken. The purpose of the alternative design is to generate a transverse electric field to recapture the ejected (secondary and tertiary) electrons. The alternate FC design is shown to be superior in its ability to recapture these electrons, including those having kinetic energies greater than the potential energy barrier determined by the repeller voltage applied to the FC.

  11. Actively Pumped Faraday Optical Filter

    Science.gov (United States)

    1996-04-30

    Richard I. Billmers Vincent M. Contarino David M. Allocca Martin F. Squicciarini William J. Scharpf 5d. PROJECT NUMBER 5e. TASK NUMBER 5f...States Patent [i9] Billmers et al. iiiiiiifflimi iilliiiiiii US005513032A [ii] Patent Number: [45] Date of Patent: 5,513,032 Apr. 30, 1996...54] ACTIVELY PUMPED FARADAY OPTICAL FILTER [75] Inventors: Richard I. Billmers , Bensalem; Vincent M. Contarino, Warrington; David M

  12. Faraday anomalous dispersion optical filters

    Science.gov (United States)

    Shay, T. M.; Yin, B.; Alvarez, L. S.

    1993-01-01

    The effect of Faraday anomalous dispersion optical filters on infrared and blue transitions of some alkali atoms is calculated. A composite system is designed to further increase the background noise rejection. The measured results of the solar background rejection and image quality through the filter are presented. The results show that the filter may provide high transmission and high background noise rejection with excellent image quality.

  13. HIE-ISOLDE Faraday cups tested with ion beams at TRIUMF

    CERN Document Server

    Cantero, E D

    2014-01-01

    The future HIE-ISOLDE Faraday cups for both the intercryomodule regions and the HEBTs have been tested using 34S+7, 4He+, 23Na+6 and 20Ne+5 beams from the ISAC-II accelerator at TRIUMF. Their performance has been characterized together with the Faraday cups from REX-ISOLDE and those from ISAC-II. The measurements were done at E/A = 1.5, 2.85 and 5.5 MeV/u, with beam intensities in the range of 100 pA to 4 nA. The performance of these Faraday cups has been compared under the same beam conditions for different bias voltages up to -350 V. Within the experimental uncertainties, most of them coming from fluctuations in beam intensity, all devices showed similar results. Biasing the Faraday cup repeller ring to voltages of at least -60 V, the escape of secondary electrons was suppressed.

  14. A low-mass faraday cup experiment for the solar wind

    Science.gov (United States)

    Lazarus, A. J.; Steinberg, J. T.; McNutt, R. L., Jr.

    Faraday cups have proven to be very reliable and accurate instruments capable of making 3-D velocity distribution measurements on spinning or 3-axis stabilized spacecraft. Faraday cup instrumentation continues to be appropriate for heliospheric missions. As an example, the reductions in mass possible relative to the solar wind detection system about to be flown on the WIND spacecraft were estimated. Through the use of technology developed or used at the MIT Center for Space Research but were not able to utilize for WIND: surface-mount packaging, field-programmable gate arrays, an optically-switched high voltage supply, and an integrated-circuit power converter, it was estimated that the mass of the Faraday Cup system could be reduced from 5 kg to 1.8 kg. Further redesign of the electronics incorporating hybrid integrated circuits as well as a decrease in the sensor size, with a corresponding increase in measurement cycle time, could lead to a significantly lower mass for other mission applications. Reduction in mass of the entire spacecraft-experiment system is critically dependent on early and continual collaborative efforts between the spacecraft engineers and the experimenters. Those efforts concern a range of issues from spacecraft structure to data systems to the spacecraft power voltage levels. Requirements for flight qualification affect use of newer, lighter electronics packaging and its implementation; the issue of quality assurance needs to be specifically addressed. Lower cost and reduced mass can best be achieved through the efforts of a relatively small group dedicated to the success of the mission. Such a group needs a fixed budget and greater control over quality assurance requirements, together with a reasonable oversight mechanism.

  15. A low-mass faraday cup experiment for the solar wind

    Science.gov (United States)

    Lazarus, A. J.; Steinberg, J. T.; Mcnutt, R. L., Jr.

    1993-01-01

    Faraday cups have proven to be very reliable and accurate instruments capable of making 3-D velocity distribution measurements on spinning or 3-axis stabilized spacecraft. Faraday cup instrumentation continues to be appropriate for heliospheric missions. As an example, the reductions in mass possible relative to the solar wind detection system about to be flown on the WIND spacecraft were estimated. Through the use of technology developed or used at the MIT Center for Space Research but were not able to utilize for WIND: surface-mount packaging, field-programmable gate arrays, an optically-switched high voltage supply, and an integrated-circuit power converter, it was estimated that the mass of the Faraday Cup system could be reduced from 5 kg to 1.8 kg. Further redesign of the electronics incorporating hybrid integrated circuits as well as a decrease in the sensor size, with a corresponding increase in measurement cycle time, could lead to a significantly lower mass for other mission applications. Reduction in mass of the entire spacecraft-experiment system is critically dependent on early and continual collaborative efforts between the spacecraft engineers and the experimenters. Those efforts concern a range of issues from spacecraft structure to data systems to the spacecraft power voltage levels. Requirements for flight qualification affect use of newer, lighter electronics packaging and its implementation; the issue of quality assurance needs to be specifically addressed. Lower cost and reduced mass can best be achieved through the efforts of a relatively small group dedicated to the success of the mission. Such a group needs a fixed budget and greater control over quality assurance requirements, together with a reasonable oversight mechanism.

  16. Study on simulation and experiment of array micro Faraday cup ion detector for FAIMS

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    An array micro Faraday cup ion detector for FAIMS (High-field Asymmetric Waveform Ion Mobility Spectrometry) was introduced, with which the size of the FAIMS system was reduced. With simple structure, good stability, low noise, large measurements range, this detector can work under the condition of atmospheric pressure. The array micro Faraday cup was composed of gate electrode, sensitive electrode and shielding electrode. The sensitive electrode was made of tens of crossing silicon columns with diameter of 200 μm. It was fabricated through typical MEMS technology, which was compatible completely with plane FAIMS. It was shown from FLUENT simulation result that the resistance to gas motion was low and the flow field distribution was helpful for full absorption of the ion in this array design. Through electricity simulation, the method to reduce interference on the detection signal of the micro Faraday cup was given out. Connecting with KEITHLEY 237 ampere meter, the noise level of the array micro Faraday cup was lower than 0.5 pA. The output signal of the acetone sample measured by experiment was about 210 pA. Through contrast experiment, the design parameter of the micro Faraday cup was obtained primarily. This array micro Faraday cup can meet the requirements of the FAIMS system.

  17. Faraday Cup for Electron Flux Measurements on the Microtron MT 25

    Directory of Open Access Journals (Sweden)

    M. Vognar

    2001-01-01

    Full Text Available The basic criteria for constructing of an evacuated Faraday cup for precise measurement of 5 to 25 MeV electron beam currents in air from a microtron are established. The Faraday cup, built in the microtron laboratory of the Faculty of Nuclear Sciences and Physical Engineering of CTU Prague, is described together with the electronic chain and its incorporation in the measuring line on the beam. Measures to reduce the backward escape of electrons are explained. The range of currents is from 10–5 to 10–10 A. The diameter of the Al entry window of the Faraday cup is 1.8 cm, and its area is 2.54 cm2. The thickness of the entry window is 0.1 mm.

  18. Optic atrophy and glaucomatous cupping.

    Science.gov (United States)

    Radius, R L; Maumenee, A E

    1978-02-01

    We reviewed 170 eyes of 112 patients with optic atrophy from various causes. Special attention was directed towards measured cup:disk ratios as well as presence of glaucomatous-like cupping of the optic nerve head. We observed a small but significant increase in nerve head cupping in eyes with optic atrophy when compared to contralateral eyes, as well as to eyes of 50 diabetic patients. No characteristic glaucomatous disk changes were documented. We evaluated these findings with respect to possible causes of glaucomatous disk and field changes.

  19. Faraday Cup - it is used to measure beam intensities at low energy beams.

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    A Faraday Cup is used to measure beam intensities at low energy beams. An electrically isolated metallic electrode intercepts the beam and captures all its charges. These charges are integrated using an current sensitive amplifier. When the beam impinges onto the electrode surface low energy electrons are liberated. In order to prevent these electrons from escaping the cup and thus falsifying the measurement, a repeller electrode with negative potential pushes the electrons back onto the electrode.

  20. A potassium Faraday anomalous dispersion optical filter

    Science.gov (United States)

    Yin, B.; Shay, T. M.

    1992-01-01

    The characteristics of a potassium Faraday anomalous dispersion optical filter operating on the blue and near infrared transitions are calculated. The results show that the filter can be designed to provide high transmission, very narrow pass bandwidth, and low equivalent noise bandwidth. The Faraday anomalous dispersion optical filter (FADOF) provides a narrow pass bandwidth (about GHz) optical filter for laser communications, remote sensing, and lidar. The general theoretical model for the FADOF has been established in our previous paper. In this paper, we have identified the optimum operational conditions for a potassium FADOF operating on the blue and infrared transitions. The signal transmission, bandwidth, and equivalent noise bandwidth (ENBW) are also calculated.

  1. Optimization of a Short Faraday Cup for Low-Energy Ions using Numerical Simulations

    CERN Document Server

    Bravin, E; Garcia Sosa, A; Welsch, CP

    2014-01-01

    ISOLDE, the heavy-ion facility at CERN is undergoing a major upgrade with the installation of a superconducting LINAC that will allow post-acceleration of ion beams up to 10 MeV/u. In this framework, customized beam diagnostics are being developed in order to fulfill the design requirements as well as to fit in the compact diagnostic boxes foreseen. The main detector of this system is a compact Faraday cup that will measure beam intensities in the range of 1 pA to 1 nA. In this contribution, simulation results of electrostatic fields and particle tracking are detailed for different Faraday cup prototypes taking into account the energy spectrum and angle of emission of the ion-induced secondary electrons.

  2. TNSA Heavy Ion Measurements using the Time-Resolved Tandem Faraday Cup

    Science.gov (United States)

    Ginnane, M. K.; Kousar, B.; Slish, J.; Palmisano, K.; Mandanas, S.; Padalino, S. J.; Sangster, T. C.; Regan, S.; Mileham, C.; Stoeckl, C.

    2016-10-01

    The MTW Laser at LLE utilizes an ultra-intense laser to produce high-energy heavy ion pulses through Target Normal Sheath Acceleration (TNSA). Using the Time-Resolved Tandem Faraday Cup (TRTF) the total number of heavy ions produced by TNSA can be determined, which is needed for stellar nuclear reaction cross section measurements. TNSA heavy ions stop within the thin walled front cup, while light ions pass through it and deposit their remaining charge in the back cup. A two channel storage scope measures voltages produced by the beam currents collected in the cups, respectively. The charge state fraction of plasma ions is modified by passing the heavy ions through a charge-exchange foil at the TRTF entrance. While passing through the foil, ions equilibrate to known charge states based on their velocities. Using time of flight, the total heavy ion current can be normalized to the correct charge state fraction. A pair of dipole magnets deflect relativistic TNSA electrons from the cup's entrance. They also prevent secondary electrons from escaping the front and back cups. Funded in part by a LLE contract through the DOE.

  3. Faraday cup detector array with electronic multiplexing for multichannel mass spectrometry

    CERN Document Server

    Scheidemann, A A; Schumacher, F J; Isakharov, A

    2002-01-01

    A Faraday cup detector array (FCDA) and electronic multiplexing circuit have been developed for position sensitive ion beam detection. The entire FCDA always remains open to intercept the incident ion beam flux, and each cup is periodically and sequentially discharged through the electronic multiplexer. This produces true multichannel ion beam detection since none of the incident ion beam flux is lost, as is the case for scanning position sensitive detectors, and higher sensitivity detection is thus obtained. The FCDA consists of a one-dimensional or two-dimensional array of individual cups which are electrostatically isolated from each other by means of an intervening ground conductor, with resulting fill factors F of 58% to 85%. Each cup acts as a charge collector and integrator which is quickly discharged during the readout to create a time-multiplexed output signal that gives the position distribution of the ion beam. When N cups are sequentially scanned and read out, the ion collection efficiency is F(1-...

  4. Faraday-cup-type lost fast ion detector on Heliotron J

    Science.gov (United States)

    Yamamoto, S.; Ogawa, K.; Isobe, M.; Darrow, D. S.; Kobayashi, S.; Nagasaki, K.; Okada, H.; Minami, T.; Kado, S.; Ohshima, S.; Weir, G. M.; Nakamura, Y.; Konoshima, S.; Kemmochi, N.; Ohtani, Y.; Mizuuchi, T.

    2016-11-01

    A Faraday-cup type lost-fast ion probe (FLIP) has been designed and installed in Heliotron J for the purpose of the studies of interaction between fast ions and MHD instabilities. The FLIP can measure the co-going fast ions whose energy is in the range of 1.7-42.5 keV (proton) and pitch angle of 90∘-140∘, especially for fast ions having the injection energy of neutral beam injection (NBI). The FLIP successfully measured the re-entering passing ions and trapped lost-fast ions caused by fast-ion-driven energetic particle modes in NBI heated plasmas.

  5. Faraday-cup-type lost fast ion detector on Heliotron J.

    Science.gov (United States)

    Yamamoto, S; Ogawa, K; Isobe, M; Darrow, D S; Kobayashi, S; Nagasaki, K; Okada, H; Minami, T; Kado, S; Ohshima, S; Weir, G M; Nakamura, Y; Konoshima, S; Kemmochi, N; Ohtani, Y; Mizuuchi, T

    2016-11-01

    A Faraday-cup type lost-fast ion probe (FLIP) has been designed and installed in Heliotron J for the purpose of the studies of interaction between fast ions and MHD instabilities. The FLIP can measure the co-going fast ions whose energy is in the range of 1.7-42.5 keV (proton) and pitch angle of 90(∘)-140(∘), especially for fast ions having the injection energy of neutral beam injection (NBI). The FLIP successfully measured the re-entering passing ions and trapped lost-fast ions caused by fast-ion-driven energetic particle modes in NBI heated plasmas.

  6. Rapid determination of Faraday rotation in optical glasses by means of secondary Faraday modulator.

    Science.gov (United States)

    Sofronie, M; Elisa, M; Sava, B A; Boroica, L; Valeanu, M; Kuncser, V

    2015-05-01

    A rapid high sensitive method for determining the Faraday rotation of optical glasses is proposed. Starting from an experimental setup based on a Faraday rod coupled to a lock-in amplifier in the detection chain, two methodologies were developed for providing reliable results on samples presenting low and large Faraday rotations. The proposed methodologies were critically discussed and compared, via results obtained in transmission geometry, on a new series of aluminophosphate glasses with or without rare-earth doping ions. An example on how the method can be used for a rapid examination of the optical homogeneity of the sample with respect to magneto-optical effects is also provided.

  7. Design and Construction of a Fast Ion Loss Faraday Cup Array Diagnostic for JET

    Energy Technology Data Exchange (ETDEWEB)

    D.S. Darrow; S. Bauumel; F.E. Cecil; V. Kiptily; R. Ellis; L. Pedrick; A. Werner

    2004-04-26

    A thin foil Faraday cup array is being built to measure the loss of 3.5 MeV alpha particles and MeV ion cyclotron heating (ICH) tail ions on JET. It will consist of nine detectors spread over five different poloidal locations and three radial positions. They will measure the poloidal distribution and radial scrape off of the losses. The detectors will be comprised of four layers of thin (2.5 micron) Ni foil, giving some resolution of the lost particle energy distribution as different ranges of energies will stop in different layers of the detector. One detector will utilize eight thinner (1.0 micron) foils to obtain a better resolved energy distribution. These detectors will accept particles incident up to 45{sup o} from the normal to the foils.

  8. Slit disk for modified faraday cup diagnostic for determining power density of electron and ion beams

    Science.gov (United States)

    Teruya, Alan T.; Elmer; John W.; Palmer, Todd A.

    2011-03-08

    A diagnostic system for characterization of an electron beam or an ion beam includes an electrical conducting disk of refractory material having a circumference, a center, and a Faraday cup assembly positioned to receive the electron beam or ion beam. At least one slit in the disk provides diagnostic characterization of the electron beam or ion beam. The at least one slit is located between the circumference and the center of the disk and includes a radial portion that is in radial alignment with the center and a portion that deviates from radial alignment with the center. The electron beam or ion beam is directed onto the disk and translated to the at least one slit wherein the electron beam or ion beam enters the at least one slit for providing diagnostic characterization of the electron beam or ion beam.

  9. The Study of a Beam Profile Monitor based on Faraday Cup Array

    Energy Technology Data Exchange (ETDEWEB)

    Park, K. M.; Park, S. H.; Kim, S. G.; Kwon, H. J.; Cho, Y. S. [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    The metal can then be discharged to measure a small current equivalent to the number of impinging ions. The beam current can be measured and used to determine the number of ions or electrons hitting the cup. Recently, beam profile monitor (BPM) based on Faraday cup array (FCA), which represented beam position through the spatial and temporal distribution of the beam current, has been studied due to advantages of measure of wide-range ion beam current. FCA system is divided into a FC, an electrical circuit and display parts. We have studied FCA to monitor beam profile on an electrostatic accelerator with wide-range ion current. In this paper, we represented basic characteristics and designs for the fabricated FCA. FCA system, which consisted of FC system, electronic readout system, and output display, was suggested to measure ion beam current, efficiently. FC system consisted of a collimator, suppressor, tiny FC, insulator frame, and circuit board divided into elec PCB, cap PCB, and con PCB. FC size was 4 mm diameters and FCA system was considered as 8 x 8 array and whole size of 8 x 8 mm''2. FCA system was set-up in vacuum chamber and an integrator and output display parts were formed out of chamber to minimize number of feed-through.

  10. The design, development, and implementation of a solar environmental simulator (SES) for the SAO Faraday Cup on Solar Probe Plus

    Science.gov (United States)

    Cheimets, Peter; Bookbinder, Jay; Freeman, Mark; Gates, Richard; Gauron, Thomas; Guth, Giora; Kasper, Justin; McCracken, Kenneth; Podgorski, William

    2013-09-01

    This paper describes the implementation of a solar simulator, know as the Solar Environment Simulator (SES), that can simulate solar flux levels up to those encountered at 9.8 solar radii. The paper outlines the design, and the challenges of realizing the SES. It also describes its initial uses for proving out the design of the Solar Winds Electrons, Alphas, and Protons (SWEAP) Faraday cup. The upcoming Solar Probe Plus (SPP) mission requires that its in-situ plasma instrument (the Faraday Cup) survive and operate over an unprecedented range of temperatures. One of the key risk mitigation activities during Phase B has been to develop and implement a simulator that will enable thermal testing of the Faraday Cup under flight-like conditions. While still in the initial start-up, the SES has proven to be an instrumental component in the process of predicting the inflight performance of the SWEAP Faraday Cup. With near continuously variable power control above the threshold of 1.6kW/lamp up to approximately 6.5kW/lamp, the SES has been used to determine the system response to a wide range of incoming flux, thereby making it possible to correlate detailed thermal models to a high degree of certainty (see Ref. [1], Figure 1.1). The SES consists of a set of repurposed, and slightly re-designed standard movie projectors. The projectors have proven to be an economical and effective means to safely hold and control the xenon short-arc lamps that are the basis of the SES. This paper outlines the key challenges controlling the extremely high flux levels (~70w/cm^2) necessary to make the SES a useful test facility.

  11. Material Development of Faraday Cup Grids for the Solar Probe Plus Mission

    Science.gov (United States)

    Volz, M. P.; Mazuruk, K.; Wright, K. H.; Cirtain, J. W.; Lee, R.; Kasper, J. C.

    2011-01-01

    The Solar Probe Plus mission will launch a spacecraft to the Sun to study it's outer atmosphere. One of the instruments on board will be a Faraday Cup (FC) sensor. The FC will determine solar wind properties by measuring the current produced by ions striking a metal collector plate. It will be directly exposed to the Sun and will be subject to the temperature and radiation environment that exist within 10 solar radii. Conducting grids within the FC are biased up to 10 kV and are used to selectively transmit particles based on their energy to charge ratio. We report on the development of SiC grids. Tests were done on nitrogen-doped SiC starting disks obtained from several vendors, including annealing under vacuum at 1400 C and measurement of their electrical properties. SiC grids were manufactured using a photolithographic and plasma-etching process. The grids were incorporated into a prototype FC and tested in a simulated solar wind chamber. The energy cutoffs were measured for both proton and electron fluxes and met the anticipated sensor requirements.

  12. Proton beam dosimetry: a comparison between a plastic scintillator, ionization chamber and Faraday cup.

    Science.gov (United States)

    Ghergherehchi, Mitra; Afarideh, Hossein; Ghannadi, Mohammad; Mohammadzadeh, Ahmad; Aslani, Golam Reza; Boghrati, Behzad

    2010-01-01

    In this study, a comparison was made between a plastic scintillator (BC400), a Faraday Cup (FC) and an ionization chamber (IC) used for routine proton dosimetry. Thin scintillators can be applied to proton dosimetry and consequently to proton therapy as relative dosimeters because of their water-equivalent nature, high energy-light conversion efficiency, low dimensions and good proportionality to the absorbed dose at low stopping powers. To employ such scintillators as relative dosimeters in proton therapy, the corrective factors must be applied to correct the quenching luminescence at the Bragg peak. A fine linear proportionality between the luminescence light yield Y and the proton flux in a thin (0.5 mm) scintillator for the 20 and 30 MeV proton beams were observed. The experimental peak/plateau ratios of Bragg Curve for 2, 1 and 0.5 mm scintillators with an accuracy of 0.5% were obtained to be 1.87, 1.91 and 2.30, respectively. With combination of the Markus chamber and the CR-39 detector, the peak/plateau ratio was improved to 3.26. The obtained data of the luminescence yield as a function of the specific energy loss is in agreement with the Craun-Birk's theory. Results show that the FC and Markus ionization chamber are in agreement within 4%, while the FC gives a lower dose evaluation. For a defined beam, the data for the fluence measurements are reproducible within a good accuracy.

  13. Design of a compact Faraday cup for low energy, low intensity ion beams

    Science.gov (United States)

    Cantero, E. D.; Sosa, A.; Andreazza, W.; Bravin, E.; Lanaia, D.; Voulot, D.; Welsch, C. P.

    2016-01-01

    Beam intensity is one of the key parameters in particle accelerators, in particular during machine commissioning, but also during operation for experiments. At low beam energies and low intensities a number of challenges arise in its measurement as commonly used non-invasive devices are no longer sensitive enough. It then becomes necessary to stop the beam in order to measure its absolute intensity. A very compact Faraday cup for determining ion beam currents from a few nanoamperes down to picoamperes for the HIE-ISOLDE post-accelerator at CERN has been designed, built and tested with beam. It has a large aperture diameter of 30 mm and a total length of only 16 mm, making it one of the most compact designs ever used. In this paper we present the different steps that were involved in the design and optimization of this device, including beam tests with two early prototypes and the final monitor. We also present an analysis of the losses caused by secondary particle emission for different repelling electrode voltages and beam energies. Finally, we show that results obtained from an analytical model for electron loss probability combined with Monte Carlo simulations of particles trajectories provide a very good agreement with experimental data.

  14. Design of a compact Faraday cup for low energy, low intensity ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Cantero, E.D., E-mail: esteban.cantero@cern.ch [CERN, 1211 Geneva 23 (Switzerland); Sosa, A. [CERN, 1211 Geneva 23 (Switzerland); The University of Liverpool, Liverpool (United Kingdom); Andreazza, W.; Bravin, E.; Lanaia, D.; Voulot, D. [CERN, 1211 Geneva 23 (Switzerland); Welsch, C.P. [The University of Liverpool, Liverpool (United Kingdom); The Cockcroft Institute, Sci-Tech Daresbury, Daresbury, Warrington (United Kingdom)

    2016-01-21

    Beam intensity is one of the key parameters in particle accelerators, in particular during machine commissioning, but also during operation for experiments. At low beam energies and low intensities a number of challenges arise in its measurement as commonly used non-invasive devices are no longer sensitive enough. It then becomes necessary to stop the beam in order to measure its absolute intensity. A very compact Faraday cup for determining ion beam currents from a few nanoamperes down to picoamperes for the HIE-ISOLDE post-accelerator at CERN has been designed, built and tested with beam. It has a large aperture diameter of 30 mm and a total length of only 16 mm, making it one of the most compact designs ever used. In this paper we present the different steps that were involved in the design and optimization of this device, including beam tests with two early prototypes and the final monitor. We also present an analysis of the losses caused by secondary particle emission for different repelling electrode voltages and beam energies. Finally, we show that results obtained from an analytical model for electron loss probability combined with Monte Carlo simulations of particles trajectories provide a very good agreement with experimental data.

  15. Design of Faraday cup ion detectors built by thin film deposition

    Science.gov (United States)

    Szalkowski, G. A.; Darrow, D. S.; Cecil, F. E.

    2017-03-01

    Thin film Faraday cup detectors can provide measurements of fast ion loss from magnetically confined fusion plasmas. These multilayer detectors can resolve the energy distribution of the lost ions in addition to giving the total loss rate. Prior detectors were assembled from discrete foils and insulating sheets. Outlined here is a design methodology for creating detectors using thin film deposition that are suited to particular scientific goals. The intention is to use detectors created by this method on the Joint European Torus (JET) and the National Spherical Torus Experiment-Upgrade (NSTX-U). The detectors will consist of alternating layers of aluminum and silicon dioxide, with layer thicknesses chosen to isolate energies of interest. Thin film deposition offers the advantage of relatively simple and more mechanically robust construction compared to other methods, as well as allowing precise control of film thickness. Furthermore, this depositional fabrication technique places the layers in intimate thermal contact, providing for three-dimensional conduction and dissipation of the ion-produced heating in the layers, rather than the essentially two-dimensional heat conduction in the discrete foil stack implementation.

  16. Optimized Extraction of H– by Three-Electrode Faraday Cup System in Magnetized Sheet Plasma Ion Source

    Directory of Open Access Journals (Sweden)

    M. S. Fernandez

    2003-06-01

    Full Text Available A locally designed rectangular parallelepiped, three-electrode Faraday cup system has been developed.Its design incorporates the capability of simultaneous extraction and deposition of the H– ions on substrates.The device functions to attain prescribed selectivity conditions of extracted ions, with controlled energies,for deposition or adsorption. It has been proven to detect the ions at filter bias voltage of 13.61 V with acurrent density of 5.3 A/m2 that is relatively higher than reported (Abate & Ramos, 2000.

  17. Theoretical model for a Faraday anomalous dispersion optical filter

    Science.gov (United States)

    Yin, B.; Shay, T. M.

    1991-01-01

    A model for the Faraday anomalous dispersion optical filter is presented. The model predicts a bandwidth of 0.6 GHz and a transmission peak of 0.98 for a filter operating on the Cs (D2) line. The model includes hyperfine effects and is valid for arbitrary magnetic fields.

  18. Analytic methods in assessment of optic nerve cupping.

    Science.gov (United States)

    Jindra, L F; Kuběna, T; Gaudino, R N

    2014-06-01

    The intent of this paper is to provide a systems-based analysis of the methods used to evaluate optic nerve cupping, identify potential flaws in these systems, and propose alternatives better to assess this anatomic quantity. Estimation of optic nerve cupping requires an analytic understanding of both the psychophysical as well as the mathematical bases inherent in this measure. When the (decimal-based) cup-to-disc ratio is used to quantitate optic nerve cupping, a one-dimensional, linear estimate is produced, which in turn is derived from two- or three-dimensional, non-linear physical quantities of area or volume, respectively. When extrapolating from volume, to area, to linear measures, due to the psychophysical constraints which limit this task, such a data-compressed estimate of optic nerve cupping may neither accurately reflect, nor correctly represent, the true amount of cupping actually present in the optic nerve head. This type of one-dimensional metric (when comparing calculations from two- or three-dimensional measures over a range of optic nerve cupping), appears to introduce errors which, while most pronounced earlier on in the disease progression, often overestimate the amount of relative cupping (percent cupping) present in a pathological process like glaucoma. The same systemic errors can also lead to overestimation of the progression in cupping, especially in optic nerves with low cup-to disc values. To provide clinically meaningful estimates of optic nerve cupping, the practitioner needs to be aware of psychophysical and mathematical limitations inherent in using a linear cup-to-disc ratio to estimate the amount of cupping observed in a physical structure like the optic disc. The resultant flaws introduced by observer extrapolation from three, to two, to one dimensions (volume, area, and linear); transposition from non-linear to linear quantities; and optical illusions, caused by factors like disc topology, morphology, and ametropia, can all

  19. An integral test of FLUKA nuclear models with 160 MeV proton beams in multi-layer Faraday cups

    CERN Document Server

    Rinaldi, I; Parodi, K; Ferrari, A; Sala, P; Mairani, A

    2011-01-01

    Monte Carlo (MC) codes are useful tools to simulate the complex processes of proton beam interactions with matter. In proton therapy, nuclear reactions influence the dose distribution. Therefore, the validation of nuclear models adopted in MC codes is a critical requisite for their use in this field. A simple integral test can be performed using a multi-layer Faraday cup (MLFC). This method allows separation of the nuclear and atomic interaction processes, which are responsible for secondary particle emission and the finite primary proton range, respectively. In this work, the propagation of 160 MeV protons stopping in two MLFCs made of polyethylene and copper has been simulated by the FLUKA MC code. The calculations have been performed with and without secondary electron emission and transport, as well as charge sharing in the dielectric layers. Previous results with other codes neglected those two effects. The impact of this approximation has been investigated and found to be relevant only in the proximity ...

  20. Design and construction of a Faraday cup for measurement of small electronic currents

    Science.gov (United States)

    Veyssiere, A.

    1985-01-01

    The design of a device to measure and integrate very small currents generated by the impact of a charged particle beam upon a Faraday cut is described. The main component is a graphite block capable of stopping practically all the incident changes. The associated electronic apparatus required to measure better than 10/13 ampere with a precision of 10/0 is described.

  1. Observation of alpha particle loss from JET plasmas during ion cyclotron resonance frequency heating using a thin foil Faraday cup detector array

    Energy Technology Data Exchange (ETDEWEB)

    Darrow, D. S. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Cecil, F. E. [Physics Department, Colorado School of Mines, Golden, Colorado 80401 (United States); Kiptily, V.; Fullard, K.; Horton, A. [Culham Centre for Fusion Energy, Euratom/CCFE Fusion Assoc., Abingdon, Oxon OX14 3DB (United Kingdom); Murari, A. [Consorzio RFX-Associazione EURATOM ENEA per la Fusione, I-35127 Padova (Italy); Collaboration: JET EFDA Contributors

    2010-10-15

    The loss of MeV alpha particles from JET plasmas has been measured with a set of thin foil Faraday cup detectors during third harmonic heating of helium neutral beam ions. Tail temperatures of {approx}2 MeV have been observed, with radial scrape off lengths of a few centimeters. Operational experience from this system indicates that such detectors are potentially feasible for future large tokamaks, but careful attention to screening rf and MHD induced noise is essential.

  2. Hollow cathode lamp based Faraday anomalous dispersion optical filter.

    Science.gov (United States)

    Pan, Duo; Xue, Xiaobo; Shang, Haosen; Luo, Bin; Chen, Jingbiao; Guo, Hong

    2016-07-15

    The Faraday anomalous dispersion optical filter (FADOF), which has acquired wide applications, is mainly limited to some gaseous elements and low melting-point metals before, for the restriction of the attainable atomic density. In conventional FADOF systems a high atomic density is usually achieved by thermal equilibrium at the saturated vapor pressure, hence for elements with high melting-points a high temperature is required. To avoid this restriction, we propose a scheme of FADOF based on the hollow cathode lamp (HCL), instead of atomic vapor cells. Experimental results in strontium atoms verified this scheme, where a transmission peak corresponding to the (88)Sr (5s(2))(1)S0 - (5s5p)(1)P1 transition (461 nm) is obtained, with a maximum transmittance of 62.5% and a bandwith of 1.19 GHz. The dependence of transmission on magnetic field and HCL discharge current is also studied. Since the state-of-art commercial HCLs cover about 70 elements, this scheme can greatly expand the applications of FADOFs, and the abundant atomic transitions they provide bring the HCL based FADOFs potential applications for frequency stabilization.

  3. Fluence measurements applied to 5-20 MeV/amu ion beam dosimetry by simultaneous use of a total-absorption calorimeter and a Faraday cup

    CERN Document Server

    Kojima, T; Takizawa, H; Tachibana, H; Tanaka, R

    1998-01-01

    A Faraday cup was fabricated for measuring the beam current of a few tens MeV/amu ion beams of the TIARA AVF cyclotron. It has been applied as a beam monitor for studying the characteristics of film dosimeters that are well-established for high doses of sup 6 sup 0 Co gamma-rays and 1 to 10 MeV electrons. A total absorption calorimeter designed to measure energy fluence has also been tested for estimating the uncertainty in fluence measurement of 5-20 MeV/amu ion beams, by simultaneous use of the calorimeter and the Faraday cup in a broad uniform fluence field. The estimated fluence was evaluated on the basis of nominal particle energy values derived from the cyclotron acceleration parameters. The average ratio of the measured fluence values to the estimated values is 1.024, and the average precision is within +-2% at a 68% confidence level, for most of the ion beams with a range of kinetic energy per nucleon, 5-20 MeV/amu, at an integrated charge above 5 nC/cm sup 2.

  4. A two-in-one Faraday rotator mirror exempt of active optical alignment.

    Science.gov (United States)

    Wan, Qiong; Wan, Zhujun; Liu, Hai; Liu, Deming

    2014-02-10

    A two-in-one Faraday rotator mirror was presented, which functions as two independent Faraday rotation mirrors with a single device. With the introduction of a reflection lens as substitution of the mirror in traditional structure, this device is characterized by exemption of active optical alignment for the designers and manufacturers of Faraday rotator mirrors. A sample was fabricated by passive mechanical assembly. The insertion loss was measured as 0.46 dB/0.50 dB for the two independent ports, respectively.

  5. Segmentation of the Optic Disc and Optic Cup Using Histogram Feature-Based Adaptive Threshold for Cup to Disk Ratio

    Directory of Open Access Journals (Sweden)

    Nugraha Gibran Satya

    2016-01-01

    Full Text Available Glaucoma is a condition of increased intraocular pressure within the eyes. Such increase then causes the damage on optic nerves as the organ bringing information to be processed in brain. One of the parameters to detect the glaucoma is the ratio between the optic cup and optic disc that can be identified through an examination towards the retinal fundus image of the patient. The ratio is obtained by firstly calculating the width of the area of the optic cup and the optic disc. This research was aimed to propose a method of the segmentation of the optic cup and optic disc with the adaptive threshold. The value of the adaptive threshold was obtained once calculating the mean value and standard deviation on the retinal fundus image of the patient. Before conducting the segmentation, the red component of the image would firstly be extracted followed by doing the contrast stretching. The last one was to perform the morphological operation such as closing and opening to remove the blood vessel to make the ratio calculation more accurate. This method has been tested in a number of retinal fundus images coming from DRISTHI-GS and RIM-ONE.

  6. Enhanced Faraday Rotation via Resonant Tunnelling in Tri-Layers Containing Magneto-Optical Metals

    CERN Document Server

    Moccia, Massimo; Galdi, Vincenzo; Alu', Andrea; Engheta, Nader

    2013-01-01

    We study resonant tunnelling effects that can occur in tri-layer structures featuring a dielectric layer sandwiched between two magneto-optical-metal layers. We show that the resonance splitting associated with these phenomena can be exploited to enhance Faraday rotation at optical frequencies. Our results indicate that, in the presence of realistic loss levels, a tri-layer structure of sub-wavelength thickness is capable of yielding sensible (~10{\\deg}) Faraday rotation with transmittance levels that are an order of magnitude larger than those attainable with a standalone slab of magneto-optical metal of same thickness.

  7. Effective optical Faraday rotations of semiconductor EuS nanocrystals with paramagnetic transition-metal ions.

    Science.gov (United States)

    Hasegawa, Yasuchika; Maeda, Masashi; Nakanishi, Takayuki; Doi, Yoshihiro; Hinatsu, Yukio; Fujita, Koji; Tanaka, Katsuhisa; Koizumi, Hitoshi; Fushimi, Koji

    2013-02-20

    Novel EuS nanocrystals containing paramagnetic Mn(II), Co(II), or Fe(II) ions have been reported as advanced semiconductor materials with effective optical rotation under a magnetic field, Faraday rotation. EuS nanocrystals with transition-metal ions, EuS:M nanocrystals, were prepared by the reduction of the Eu(III) dithiocarbamate complex tetraphenylphosphonium tetrakis(diethyldithiocarbamate)europium(III) with transition-metal complexes at 300 °C. The EuS:M nanocrystals thus prepared were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), inductively coupled plasma atomic emission spectroanalysis (ICP-AES), and a superconducting quantum interference device (SQUID) magnetometer. Enhanced Faraday rotations of the EuS:M nanocrystals were observed around 550 nm, and their enhanced spin polarization was estimated using electron paramagnetic resonance (EPR) measurements. In this report, the magneto-optical relationship between the Faraday rotation efficiency and spin polarization is discussed.

  8. Periodic reversal of magneto-optic Faraday rotation on uniaxial birefringence crystal with ultrathin magnetic films

    Directory of Open Access Journals (Sweden)

    C. W. Su

    2013-07-01

    Full Text Available An experimental approach of inclined incidence magneto-optic Faraday effect observed in the polar plane is applied. Three samples containing ferromagnetic cobalt ultrathin films on a semiconductor zinc oxide (0001 single crystal substrate with in-plane and out-of-plane anisotropy are evaluated. Through the fine adjustment of crossed polarizers in the magneto-optic effect measurement completely recorded the detail optical and magneto-optical responses from the birefringent crystal substrate and the magnetic film, especially for the signal induced from the substrate with uniaxial optical axis. The angle dependency of interference phenomena periodically from the optical and magneto-optical responses is attributed to the birefringence even in the absence of a magnetic field. The new type of observation finds that the transmission Faraday intensity in the oblique incidence includes a combination of polarization rotations, which results from optical compensation from the substrate and magneto-optical Faraday effects from the film. The samples grown at different rates and examined by this method exhibit magnetic structure discriminations. This result can be applied in the advanced polarized-light technologies to enhance the spatial resolution of magnetic surfaces with microstructural information under various magnetic field direction.

  9. Optical absorption and Faraday rotation in spin doped Cd1-xHgxSe : Mn crystals

    NARCIS (Netherlands)

    Savchuk, AI; Paranchich, SY; Paranchich, LD; Romanyuk, OS; Andriychuk, MD; Nikitin, PI; Tomlinson, RD; Hill, AE; Pilkington, RD

    1998-01-01

    Optical absorption spectra and the Faraday effect in crystals of Cd1-xHgxSe : Mn have been studied. The studied samples have been characterized abrupt absorption edge and transparency region with high transmission coefficient. The measured values of Verdet constant were considerably larger than in I

  10. Faraday rotation and magneto-optical figure of merit for the magnetite magnetic fluids

    Directory of Open Access Journals (Sweden)

    Kalandadze L.

    2011-05-01

    Full Text Available In the present paper, using magnetite magnetic fluids as examples, we consider the optical and magneto-optical properties of magnetic fluids based on particles of magnetic oxides, for the optical constants of the material of which, n and k , the relation k2 ≺≺ n2 holds. In this work the Faraday rotation is represented within the theoretical Maxwell-Garnett model. A theoretical analysis has shown that Faraday rotation for magnetic fluids is related to the Faraday rotation on the material of particles by the simple relation. According to this result  in specific experimental conditions the values of the Faraday rotation prorate to q , which is the occupancy of the volume of the magnetic fluid with magnetic particles and spectral dependences of effect in magnetic fluid and in the proper bulk magnetic are similar. We also show that the values of the magneto-optical figure of merit for ultrafine medium and for the bulk material are equal.

  11. Polarization-induced noise in a fiber-optic Michelson interferometer with Faraday rotator mirror elements.

    Science.gov (United States)

    Ferreira, L A; Santos, J L; Farahi, F

    1995-10-01

    Faraday rotator mirror elements have been used in a number of applications as compensators for induced birefringence in retracing paths. In interferometric systems, such as the fiber-optic Michelson interferometer, this approach proved to be useful in providing maximum fringe visibility and insensitivity to the polarization state of light injected into the interferometer. However, it is found that, when the characteristics of the fiber coupler depend on the polarization state of the input beam, the efficiency of the Faraday mirror elements is limited. Theoretical analysis and experimental results in support of this statement are presented.

  12. Polarization-induced noise in a fiber-optic Michelson interferometer with Faraday rotator mirror elements

    Science.gov (United States)

    Ferreira, L. A.; Santos, J. L.; Farahi, F.

    1995-10-01

    Faraday rotator mirror elements have been used in a number of applications as compensators for induced birefringence in retracing paths. In interferometric systems, such as the fiber-optic Michelson interferometer, this approach proved to be useful in providing maximum fringe visibility and insensitivity to the polarization state of light injected into the interferometer. However, it is found that, when the characteristics of the fiber coupler depend on the polarization state of the input beam, the efficiency of the Faraday mirror elements is limited. Theoretical analysis and experimental results in support of this statement are presented.

  13. Faraday rotation spectrum of magneto-optical nanoparticle aggregates

    Science.gov (United States)

    Sadrara, Mahdiyeh; Miri, MirFaez

    2017-09-01

    The interaction of light with a cluster of gyrotropic spherical particles is studied in view of a miniaturized Faraday rotator. The electromagnetic fields are expanded in terms of the vector multipole fields and the expansion of the scattered field is related to that of the incident field. An incident linearly polarized light with polarization azimuth ψ becomes elliptically polarized upon scattering from the cluster. The polarization azimuth rotation and ellipticity angle variation are almost sinusoidal functions of 2 ψ . With planar disordered clusters of bismuth-substituted yttrium iron garnet nanoparticles of radius 50 nm, polarization rotations about ±4∘ are achievable.

  14. Soft X-Ray Magneto-optical Faraday Effect around Ni M2,3 Edges

    Institute of Scientific and Technical Information of China (English)

    CHEN Kai; CUI Ming-Qi; YAN Fen; ZHAO Jia; SUN Li-Juan; ZHENG Lei; MA Chen-Yan; XI Shi-So; ZHAO Yi-Dong

    2008-01-01

    @@ We present magneto-optical (MO) Faraday spectra measured around the M2,3 edges (60-70eV) of Ni films at the Beijing Synchrotron Radiation Facility (BSRF).A polarization analysis of the final state of the transmitted radiation from the Ni film is employed to determine the Faraday rotation at the edges.The MO effect becomes resonantly enhanced at the M2,3 edges,and accordingly large values for the rotation angle β of 1.85 ± 0.19°for this ferromagnetic Ni film with thickness of 31 nm are measured. Without the magnetic field,the azimuthal angles do not shift; with parallel and antiparallel magnetic field the rotation angles shift in the opposite way and they are symmetrical.The uncertainty of Faraday rotation angles mainly comes from the data fitting and the state change of the beamline when the angles are measured.

  15. Shot-noise-limited optical Faraday polarimetry with enhanced laser noise cancelling

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jiaming [School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Department of Physics, Indiana University Purdue University Indianapolis, Indianapolis, Indiana 46202 (United States); Luo, Le, E-mail: leluo@iupui.edu; Carvell, Jeff; Cheng, Ruihua [Department of Physics, Indiana University Purdue University Indianapolis, Indianapolis, Indiana 46202 (United States); Lai, Tianshu, E-mail: stslts@mail.sysu.edu.cn; Wang, Zixin, E-mail: wangzix@mail.sysu.edu.cn [School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

    2014-03-14

    We present a shot-noise-limited measurement of optical Faraday rotations with sub-ten-nanoradian angular sensitivity. This extremely high sensitivity is achieved by using electronic laser noise cancelling and phase sensitive detection. Specially, an electronic laser noise canceller with a common mode rejection ratio of over 100 dB was designed and built for enhanced laser noise cancelling. By measuring the Faraday rotation of ambient air, we demonstrate an angular sensitivity of up to 9.0×10{sup −9} rad/√(Hz), which is limited only by the shot-noise of the photocurrent of the detector. To date, this is the highest angular sensitivity ever reported for Faraday polarimeters in the absence of cavity enhancement. The measured Verdet constant of ambient air, 1.93(3)×10{sup −9}rad/(G cm) at 633 nm wavelength, agrees extremely well with the earlier experiments using high finesse optical cavities. Further, we demonstrate the applications of this sensitive technique in materials science by measuring the Faraday effect of an ultrathin iron film.

  16. Enhancement of optical Faraday effect of nonanuclear Tb(III) complexes.

    Science.gov (United States)

    Nakanishi, Takayuki; Suzuki, Yuki; Doi, Yoshihiro; Seki, Tomohiro; Koizumi, Hitoshi; Fushimi, Koji; Fujita, Koji; Hinatsu, Yukio; Ito, Hajime; Tanaka, Katsuhisa; Hasegawa, Yasuchika

    2014-07-21

    The effective magneto-optical properties of novel nonanuclear Tb(III) complexes with Tb-O lattice (specifically, [Tb9(sal-R)16(μ-OH)10](+)NO3(-), where sal-R = alkyl salicylate (R = -CH3 (Me), -C2H5 (Et), -C3H7 (Pr), or -C4H9 (Bu)) are reported. The geometrical structures of these nonanuclear Tb(III) complexes were characterized using X-ray single-crystal analysis and shape-measure calculation. Optical Faraday rotation was observed in nonanuclear Tb(III) complexes in the visible region. The Verdet constant per Tb(III) ion of the Tb9(sal-Me) complex is 150 times larger than that of general Tb(III) oxide glass. To understand their large Faraday rotation, electron paramagnetic resonance measurements of Gd(III) complexes were carried out. In this Report, the magneto-optical relation to the coordination geometry of Tb ions is discussed.

  17. Highly Sensitive Fiber-Optic Faraday-Effect Magnetic Field Sensor Based on Yttrium Iron Garnet

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The principle and performance of a fiber-optic Faraday-effect magnetic-field sensor based on an yttrium iron garnet (YIG) and two flux concentrations are described. A single polarization maintaining optical fiber links the sensor head to the source and detection system, in which the technique of phase shift cancellation is used to cancel the phase shift that accumulate in the optical fiber. Flux concentrators were exploited to enhance the YIG crystal magneto optic sensitivity .The sensor system exhibited a noise-equivalent field of 8 and a 3 dB bandwidth of ~10 MHz.

  18. Giant magneto-optical Faraday effect of nanometer Fe-In2O3 granular films

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lin; ZHANG LianSheng; XIAO ShuQin

    2008-01-01

    The giant magneto-optical Faraday effect of nanometer ferromagnetic metal-semiconductor matrix Fe-In2O3 granular films prepared by the radio frequency sputtering are studied. The result shows that the Faraday rotation angle θF value of the granular film samples with Fe volume fraction x=35% is of the order of 105(°)/cm at room temperature. Temperature dependence of the Faraday rotation angle θF of Fe0.35(In2O2)0.65 granular films shows that θF value below 10 K increases rapidly with the decrease of the temperature, and when T=4.2 K,θF value is 106(°)/cm. Through the study of the dependence of low field susceptibility on temperature and the hysteresis loops at different temperatures, it has been found that when the temperature decreases to a critical point TP=10K, the transformation of state from ferro-magnetic to spin-glass-like occurs in Fe0.35(In2O3)0.65 granular films. The remarkable increase of the Faraday rotation angle eF value of Fe0.35(In2O3)0.65 granular films below 10 K seems to arise from the sp-d exchange interaction of the granular film samples in the spin-glass-like state.

  19. A birefringent etalon enhances the Faraday rotation of thin magneto-optical films

    Science.gov (United States)

    Almpanis, E.; Pantazopoulos, P. A.; Papanikolaou, N.; Yannopapas, V.; Stefanou, N.

    2017-07-01

    The magneto-optical response of a Faraday-active Fabry-Pérot etalon with birefringent mirrors is studied by means of electrodynamic simulations using the finite-element and the scattering-matrix methods. The specific structure under consideration consists of a magnetic garnet film sandwiched between two metallic layers, patterned with periodically spaced parallel grooves on their outer sides. Our results are analyzed by reference to the properties of the individual structural components and a consistent interpretation of the different spectral features observed is provided. It is shown that, by properly adjusting the geometrical parameters involved, strong Faraday rotation enhancement can be obtained through constructive synergy between the Fabry-Pérot resonant mode of the magneto-optical nanocavity and the slot plasmon mode localized in the grooves.

  20. Plasmon resonance enhanced optical transmission and magneto-optical Faraday effects in nanohole arrays blocked by metal antenna

    Science.gov (United States)

    Lei, Chengxin; Tang, Zhixiong; Wang, Sihao; Li, Daoyong; Chen, Leyi; Tang, Shaolong; Du, Youwei

    2017-07-01

    The properties of the optical and magneto-optical effects of an improved plasmonic nanohole arrays blocked by gold mushroom caps are investigated by using the finite difference time domain (FDTD) method. It is most noteworthy that the strongly enhanced Faraday rotation along with high transmittance has been achieved simultaneously by optimizing the parameters of nanostructure in a broad spectrum spanning visible to near-infrared frequencies, which is very important in practical application for designing novel optical and magneto-optical devices. In our designed structure, we obtained two extraordinary optical transmission (EOT) resonant peaks along with enhanced Faraday rotation and two peaks of the figure of merit (FOM). By optimizing the geometrical parameters of the structure, we can obtain an almost 10-fold enhancement of Faraday rotation with a corresponding transmittance 50%, and the FOM of 0.752 at the same wavelength. As expected, the optical and magneto-optical effects sensitively depends on the geometrical parameters of our structure, which can be simply tailored by the height of pillar, the diameter of mushroom cap, and the period of the structure, and so on. The physical mechanism of these physical phenomena in the paper has been explained in detail. These research findings are of great theoretical significance in developing the novel magneto-optical devices in the future.

  1. Physics-based Tests to Identify the Accuracy of Solar Wind Ion Measurements: A Case Study with the Wind Faraday Cups

    Science.gov (United States)

    Kasper, J. C.; Lazarus, A. J.; Steinberg, J. T.; Ogilvie, K. W.; Szabo, A.

    2006-01-01

    We present techniques for comparing measurements of velocity, temperature, and density with constraints imposed by the plasma physics of magnetized bi-Maxwellian ions. Deviations from these physics-based constraints are interpreted as arising from measurement errors. Two million ion spectra from the Solar Wind Experiment Faraday Cup instruments on the Wind spacecraft are used as a case study. The accuracy of velocity measurements is determined by the fact that differential flow between hydrogen and helium should be aligned with the ambient magnetic field. Modeling the breakdown of field alignment suggests velocity uncertainties are less than 0.16% in magnitude and 3deg in direction. Temperature uncertainty is found by examining the distribution of observed temperature anisotropies in high-beta solar wind intervals where the firehose, mirror, and cyclotron microinstabilities should drive the distribution to isotropy. The presence of a finite anisotropy at high beta suggests overall temperature uncertainties of 8%. Hydrogen and helium number densities are compared with the electron density inferred from observations of the local electron plasma frequency as a function of solar wind speed and year. We find that after accounting for the contribution of minor ions, the results are consistent with a systematic offset between the two instruments of 34%. The temperature and density methods are sensitive to non-Maxwellian features such as heat flux and proton beams and as a result are more suited to slow solar wind where these features are rare. These procedures are of general use in identifying the accuracy of observations from any solar wind ion instrument.

  2. Multi-elemental Gd, Eu, Sm, Nd isotope ratio measurements by liquid chromatography coupled to MC-ICPMS with variable Faraday cup configurations during elution.

    Science.gov (United States)

    Guéguen, Florence; Nonell, Anthony; Isnard, Hélène; Vio, Laurent; Chartier, Frédéric

    2017-01-01

    The high-precision isotopic characterization of actinides and fission products in nuclear samples is fundamental for various applications such as the management of spent nuclear fuel or the validation of neutronic calculation codes. However multi-elemental isotope ratio measurements by mass spectrometric techniques are hampered by the presence of both spectral and non-spectral interferences as complex sample matrices are encountered in such topics, but also due to the lack of high precision mass spectrometers able to cover the entire mass spectrum. This work describes a new LC-MC-ICPMS approach allowing simultaneous high-precision and multi-elemental isotope ratio measurements of four fission products of interest for nuclear issues (Nd, Sm, Eu, Gd) within a single elution run. Variable motorized Faraday cup configurations were successively used during a specifically designed elution procedure in order to take into account the non-natural Nd, Sm, Eu, Gd isotopic compositions encountered in irradiated nuclear samples. This new method, involving the relevant isotopic reference standard injection timings for on-line mass bias corrections, was validated by the analysis of a simulated fission product fraction from a (235)U-irradiated target. Reproducibilities better than 2‰ (k=2), comparable to those obtained by off-line measurements and the classic sample-standard bracketing mass bias correction approach, were obtained for all isotope ratios, except those involving isotopes with a transient signal peak apex lower than 100mV, for which the reproducibilities were comprised between 2‰ and 6‰.

  3. Narrow Bandwidth Faraday Anomalous Dispersion Optical Filter%窄带 Faraday 反常色散光学滤波器

    Institute of Scientific and Technical Information of China (English)

    刘阳; 王健; 王海华; 康智慧; 王磊; 罗梦希; 闫西章; 王潇潇; 高锦岳

    2014-01-01

    研究 Faraday 反常色散光学滤波器,给出其理论计算过程和模拟结果。结果表明, Faraday反常色散光学滤波器有线翼和线芯透过两种工作方式,其中线翼透过单峰谱线线宽约为600 MHz,透过率约为25%,线芯透过谱线线宽约为700 MHz,透过率约为100%。实验结果与理论结果相符。%To obtain the weak signal light from the high background light,a narrow bandwidth Faraday anomalous dispersion optical filter (FADOF)was studied.The theoretical model for the filter was reported.The Faraday anomalous dispersion optical filters have two working modes:two side peak transmission and center peak transmission.The former work mode can get single peak transmission of 25% with a bandwidth of about 600 MHz.The other work mode can get a spectra with a transmission rate of almost 100% and a bandwith of about 700 MHz.The experimental measurements are consistent with theoretical results.

  4. Utilization of Faraday Mirror in Fiber Optic Current Sensors

    Directory of Open Access Journals (Sweden)

    P. Fiala

    2008-12-01

    Full Text Available Fiber optic sensors dispose of some advantages in the field of electrical current and magnetic field measurement, like large bandwidth, linearity, light transmission possibilities. Unfortunately, they suffer from some parasitic phenomena. The crucial issue is the presence of induced and latent linear birefringence, which is imposed by the fiber manufacture imperfections as well as mechanical stress by fiber bending. In order to the linear birefringence compensation a promising method was chosen for pulsed current sensor design. The method employs orthogonal polarization conjugation by the back direction propagation of the light wave in the fiber. The Jones calculus analysis presents its propriety. An experimental fiber optic current sensor has been designed and realized. The advantage of the proposed method was proved considering to the sensitivity improvement.

  5. Region-based multi-step optic disk and cup segmentation from color fundus image

    Science.gov (United States)

    Xiao, Di; Lock, Jane; Manresa, Javier Moreno; Vignarajan, Janardhan; Tay-Kearney, Mei-Ling; Kanagasingam, Yogesan

    2013-02-01

    Retinal optic cup-disk-ratio (CDR) is a one of important indicators of glaucomatous neuropathy. In this paper, we propose a novel multi-step 4-quadrant thresholding method for optic disk segmentation and a multi-step temporal-nasal segmenting method for optic cup segmentation based on blood vessel inpainted HSL lightness images and green images. The performance of the proposed methods was evaluated on a group of color fundus images and compared with the manual outlining results from two experts. Dice scores of detected disk and cup regions between the auto and manual results were computed and compared. Vertical CDRs were also compared among the three results. The preliminary experiment has demonstrated the robustness of the method for automatic optic disk and cup segmentation and its potential value for clinical application.

  6. Ultraviolet-visible optical isolators based on CeF3 Faraday rotator

    Science.gov (United States)

    Víllora, Encarnación G.; Shimamura, Kiyoshi; Plaza, Gustavo R.

    2015-06-01

    The first ultraviolet (UV) and visible optical isolators based on CeF3 are demonstrated. CeF3 possesses unique properties as Faraday rotator for the UV-visible wavelength region: a wide transparency range (wavelength of >300 nm) and an outstanding Verdet constant. In contrast, currently used terbium-gallium garnets and magneto-optical glasses possess a low transparency in the visible and a small Verdet constant in the UV, respectively. The optical isolator prototypes consist of a CeF3 rod, a single ring magnet, and a couple of beam splitters. The ring magnets have been designed to guarantee a homogeneous magnetic field; for it, numerical simulations have been carried out. The two prototypes are very compact and operate in the UV at 355 and in the visible at 405 nm, respectively. The performance of these devices indicates the high potential of CeF3 as a new UV-visible Faraday rotator, specially for shorter wavelengths where at present there are no optical isolators available.

  7. dlx and sp6-9 Control optic cup regeneration in a prototypic eye.

    Directory of Open Access Journals (Sweden)

    Sylvain W Lapan

    2011-08-01

    Full Text Available Optic cups are a structural feature of diverse eyes, from simple pit eyes to camera eyes of vertebrates and cephalopods. We used the planarian prototypic eye as a model to study the genetic control of optic cup formation and regeneration. We identified two genes encoding transcription factors, sp6-9 and dlx, that were expressed in the eye specifically in the optic cup and not the photoreceptor neurons. RNAi of these genes prevented formation of visible optic cups during regeneration. Planarian regeneration requires an adult proliferative cell population with stem cell-like properties called the neoblasts. We found that optic cup formation occurred only after migration of progressively differentiating progenitor cells from the neoblast population. The eye regeneration defect caused by dlx and sp6-9 RNAi can be explained by a failure to generate these early optic cup progenitors. Dlx and Sp6-9 genes function as a module during the development of diverse animal appendages, including vertebrate and insect limbs. Our work reveals a novel function for this gene pair in the development of a fundamental eye component, and it utilizes these genes to demonstrate a mechanism for total organ regeneration in which extensive cell movement separates new cell specification from organ morphogenesis.

  8. Michael Faraday's Bicentenary.

    Science.gov (United States)

    Williams, L. Pearce; And Others

    1991-01-01

    Six articles discuss the work of Michael Faraday, a chemist whose work revolutionized physics and led directly to both classical field and relativity theory. The scientist as a young man, the electromagnetic experiments of Faraday, his search for the gravelectric effect, his work on optical glass, his laboratory notebooks, and his creative use of…

  9. All-fiber optical magnetic-field sensor based on Faraday rotation in highly terbium-doped fiber.

    Science.gov (United States)

    Sun, L; Jiang, S; Marciante, J R

    2010-03-15

    An all-fiber optical magnetic field sensor is demonstrated. It consists of a fiber Faraday rotator and a fiber polarizer. The fiber Faraday rotator uses a 2-cm-long section of 56-wt.%-terbium-doped silicate fiber with a Verdet constant of -24.5 rad/(Tm) at 1053 nm. The fiber polarizer is Corning SP1060 single-polarization fiber. The sensor has a sensitivity of 0.49 rad/T and can measure magnetic fields from 0.02 to 3.2 T.

  10. Competition of Faraday rotation and birefringence in femtosecond laser direct written waveguides in magneto-optical glass.

    Science.gov (United States)

    Liu, Qiang; Gross, S; Dekker, P; Withford, M J; Steel, M J

    2014-11-17

    We consider the process of Faraday rotation in femtosecond laser direct-write waveguides. The birefringence commonly associated with such waveguides may be expected to impact the observable Faraday rotation. Here, we theoretically calculate and experimentally verify the competition between Faraday rotation and birefringence in two waveguides created by laser writing in a commercial magneto-optic glass. The magnetic field applied to induce Faraday rotation is nonuniform, and as a result, we find that the two effects can be clearly separated and used to accurately determine even weak birefringence. The birefringence in the waveguides was determined to be on the scale of Δn = 10(-6) to 10(-5). The reduction in Faraday rotation caused by birefringence of order Δn = 10(-6) was moderate and we obtained approximately 9° rotation in an 11 mm waveguide. In contrast, for birefringence of order 10(-5), a significant reduction in the polarization azimuth change was found and only 6° rotation was observed.

  11. Enhancement of magneto-optical Faraday effects and extraordinary optical transmission in a tri-layer structure with rectangular annular arrays.

    Science.gov (United States)

    Lei, Chengxin; Chen, Leyi; Tang, Zhixiong; Li, Daoyong; Cheng, Zhenzhi; Tang, Shaolong; Du, Youwei

    2016-02-15

    The properties of optics and magneto-optical Faraday effects in a metal-dielectric tri-layer structure with subwavelength rectangular annular arrays are investigated. It is noteworthy that we obtained the strongly enhanced Faraday rotation of the desired sign along with high transmittance by optimizing the parameters of the nanostructure in the visible spectral ranges. In this system, we obtained two extraordinary optical transmission (EOT) resonant peaks with enhanced Faraday rotations, whose signs are opposite, which may provide the possibility of designing multi-channel magneto-optical devices. Study results show that the maximum of the figure of merit (FOM) of the structure can be obtained between two EOT resonant peaks accompanied by an enhanced Faraday rotation. The positions of the maximum value of the FOM and resonant peaks of transmission along with a large Faraday rotation can be tailored by simply adjusting the geometric parameters of our models. These research findings are of great importance for future applications of magneto-optical devices.

  12. Properties and structure of Faraday rotating glasses for magneto optical current transducer

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Q.; Ma, Q.; Wang, H.; Wang, Q.; Hao, Y.; Chen, Q.

    2017-07-01

    High heavy metal oxides (60–100mol.%) ternary PbO–Bi2O3–B2O3 (PBB) glasses were fabricated and characterized. Using a homemade single lightway DC magnetic setup, Verdet constants of PBB glasses were measured to be 0.0923–0.1664min/G cm at 633nm wavelengths. Glasses with substitution of PbO by Bi2O3 were studied in terms of their Faraday effects. PbO–Bi2O3–B2O3 = 50–40–10mol.% exhibited good thermal stability, high Verdet constant (0.1503min/G cm) and good figure of merit (0.071). Based on this glass, a magneto optical current sensor prototype was constructed and its sensitivity at different currents was evaluated to be 8.31nW/A. © 2. (Author)

  13. Synergetic interaction of Dark-Modes and Faraday Rotation for Enhanced Magneto-Optics

    CERN Document Server

    Mazor, Y; Steinberg, Ben Z

    2016-01-01

    We examine the efficacy of Dark-mode plasmonics as a platform for enhanced magneto-optics. Dark-mode of a small particle consists of two co-existing equal-intensity and mutually opposing dipolar excitations. Each of these two opposing dipoles may even resonate intensely at or near the dark-mode frequency, but the net dipole moment of the system vanishes due to the mutual cancelation between the opposing dipoles. We show that application of external magnetic bias may alleviate the intense destructive interference. Furthermore, under external magnetic bias the opposing dark-resonances of a plasmonic particle shift in opposite directions and create a region of extremely sensitive Faraday rotation. We show that the magnetized dark resonance in Ag particle may provide 50 degrees rotation under magnetic fields of the order of 1-2 Tesla, exhibiting magneto-plasmonic activity that is nearly three orders of magnitude larger than that observed in conventional plasmonic particle.

  14. Analysis of excited-state Faraday anomalous dispersion optical filter at 1529 nm.

    Science.gov (United States)

    Xiong, Junyu; Yin, Longfei; Luo, Bin; Guo, Hong

    2016-06-27

    In this work, a detailed theoretical analysis of 1529 nm ES-FADOF (excited state Faraday anomalous dispersion optical filter) based on rubidium atoms pumped by 780 nm laser is introduced, where Zeeman splitting, Doppler broadening, and relaxation processes are considered. Experimental results are carefully compared with the derivation. The results prove that the optimal pumping frequency is affected by the working magnetic field. The population distribution among all hyperfine Zeeman sublevels under the optimal pumping frequency has also been obtained, which shows that 85Rb atoms are the main contribution to the population. The peak transmittance above 90% is obtained, which is in accordance with the experiment. The calculation also shows that the asymmetric spectra observed in the experiment are caused by the unbalanced population distribution among Zeeman sublevels. This theoretical model can be used for all kinds of calculations for FADOF.

  15. Characteristics of Reversal Optic Cupping in Adults Glaucoma after Reduction of Intraocular Pressure

    Institute of Scientific and Technical Information of China (English)

    LiangXu; LeiLiu

    1995-01-01

    Purpose:According to Quigley's hypothesis the dense of connective tissue is the least and the pores of the lamina cribrosa are the largest at the superior and infe-rior poles of the lamina cribrosa,therefore they are the most vulnerable location to be involved in the characteristic glaucomatous optic nerve damage,To get clin-ical evidence for the hypltheses,the reversal of optic cup in adults glaucoma after reduction of intraocular pressure(IOP)was examined.Methods:The stereoscopic flicker comparison on with computerized image sys-tem was used to monitor the optic cup's changing,2 serial superposed stereo pairs were displayed alternatively and rapidly and the changing parts appeared moving Under the stereoscopic observation ,hthe changes of 3-dimention optic cup could be seen and the false positive phenomena caused by photographic angle variation,vascular pulsation could be differentiated from the characteristic change of the cup.Stereo fundus photographs were taken from 31eyes with hy-pertension glaucoma before and after treatment of reduction of IOPs which was either diamox administration or trabeculectomy.Results:the result showed that the reversal of optic cups after reduction of IOPs were mostly asymmetrical,especially at the inferior and/or superior poles.By multiple stepwise regression.it is known that the amount of the change is only correlated with the initial elevated IOP.Conclusions:The study indicated that it was the distortion and deformity of the lamina cribrosa leading to shearing stress that results in glaucomatous character-istic damage in structure and function.The individul tolerance of the lamina cribrosa to the high intraocular pressure and the locations of indivdual vulnerable at he optic nerve head are various.Eye Science1995;11:155-160.

  16. Polarization-induced phase noise in fiber optic Michelson interferometer with Faraday rotator mirrors

    Science.gov (United States)

    Wu, Yuefeng; Li, Fang; Zhang, Wentao; Xiao, Hao; Liu, Yuliang

    2008-11-01

    Polarization-induced phase noise in Michelson interferometer with imperfect Faraday rotator mirrors was investigated. This kind of noise generates from the rotation angle errors of Faraday rotator mirrors and external polarization perturbation. The conversion factor κ, representing the magnitude conversion ability from polarization-noise to polarization induced phase-noise, have been theoretically evaluated and experimentally investigated.

  17. Joint optic disc and cup boundary extraction from monocular fundus images.

    Science.gov (United States)

    Chakravarty, Arunava; Sivaswamy, Jayanthi

    2017-08-01

    Accurate segmentation of optic disc and cup from monocular color fundus images plays a significant role in the screening and diagnosis of glaucoma. Though optic cup is characterized by the drop in depth from the disc boundary, most existing methods segment the two structures separately and rely only on color and vessel kink based cues due to the lack of explicit depth information in color fundus images. We propose a novel boundary-based Conditional Random Field formulation that extracts both the optic disc and cup boundaries in a single optimization step. In addition to the color gradients, the proposed method explicitly models the depth which is estimated from the fundus image itself using a coupled, sparse dictionary trained on a set of image-depth map (derived from Optical Coherence Tomography) pairs. The estimated depth achieved a correlation coefficient of 0.80 with respect to the ground truth. The proposed segmentation method outperformed several state-of-the-art methods on five public datasets. The average dice coefficient was in the range of 0.87-0.97 for disc segmentation across three datasets and 0.83 for cup segmentation on the DRISHTI-GS1 test set. The method achieved a good glaucoma classification performance with an average AUC of 0.85 for five fold cross-validation on RIM-ONE v2. We propose a method to jointly segment the optic disc and cup boundaries by modeling the drop in depth between the two structures. Since our method requires a single fundus image per eye during testing it can be employed in the large-scale screening of glaucoma where expensive 3D imaging is unavailable. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. A generalization of the Drude-Smith formula for magneto-optical conductivities in Faraday geometry

    Science.gov (United States)

    Han, F. W.; Xu, W.; Li, L. L.; Zhang, C.

    2016-06-01

    In this study, we generalize the impulse response approach and Poisson statistics proposed by Smith [Phys. Rev. B 64, 155106 (2001)] to evaluate the longitudinal and transverse magneto-optical conductivities in an electron gas system in Faraday geometry. Comparing with the standard Drude model, the coefficients an are introduced in the Drude-Smith formula to describe the backscattering or localization effect for the nth electronic scattering event. Such a formula can also be applied to study the elements of the dielectric function matrix in the presence of magnetic and radiation fields in electron gas systems. This theoretical work is primely motivated by recent experimental activities in measuring the real and imaginary parts of longitudinal and transverse magneto-optical conductivities in condensed matter materials and electronic devices using terahertz time-domain spectroscopy. We believe that the results obtained from this study can provide an appropriate theoretical tool in reproducing the experimental findings and in fitting with experimental data to determine the important sample and material parameters.

  19. Influence of gamma-ray irradiation on Faraday effect of Cu-doped germano-silicate optical fiber

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Youngwoong; Ju, Seongmin; Jeong, Seongmook; Jang, Myoung-Jin [Department of Physics and Photon Science, School of Information and Communications, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro, Buk-Gu, Gwangju 500-712 (Korea, Republic of); Kim, Jong-Yeol; Lee, Nam-Ho; Jung, Hyun-Kyu [Nuclear Convergence Technology Development Department, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon (Korea, Republic of); Han, Won-Taek, E-mail: wthan@gist.ac.kr [Department of Physics and Photon Science, School of Information and Communications, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro, Buk-Gu, Gwangju 500-712 (Korea, Republic of)

    2015-02-01

    Influence of gamma-ray irradiation on the Faraday effect of the Cu-doped germano-silicate optical fiber was investigated. The Verdet constant of the gamma-ray irradiated optical fiber at 660 nm was measured to be 3.07 rad T{sup −1} m{sup −1}, 1.46 times larger than that of before the irradiation at total dose of 1200 Gy. Cu-related radiation-induced defect centers and Cu metal particles which were reduced from Cu{sup 2+} ions by the irradiation are thought to be responsible for the increase in the Verdet constant of the optical fiber.

  20. Dark mode-Faraday rotation synergy for enhanced magneto-optics

    Science.gov (United States)

    Mazor, Y.; Meir, M.; Steinberg, Ben Z.

    2017-01-01

    We examine the efficacy of dark-mode plasmonics as a platform for enhanced magneto-optics. The dark mode of a small particle consists of two co-existing equal-intensity and mutually opposing dipolar excitations. Each of these two opposing dipoles may even resonate at or near the dark-mode frequency, but the net dipole moment vanishes due to the mutual cancellation between the opposing dipoles. We show that application of external magnetic bias may alleviate the intense destructive interference. Furthermore, under external magnetic bias the opposing dark resonances of a plasmonic particle shift in opposite directions and create a region of extremely sensitive Faraday rotation. We show that the magnetized dark resonance in a lossless Ag-like particle may provide more than 20 degrees rotation under magnetic fields of the order of 1-2 Tesla, exhibiting magnetoplasmonic activity that is 2-3 orders of magnitude larger than that observed in a conventional plasmonic particle of the same material.

  1. Faraday rotation dispersion measurements of diamagnetic organic liquids and simultaneous determination of natural optical rotatory dispersion using a pulsed magnetic field.

    Science.gov (United States)

    Suwa, Masayori; Miyamoto, Kayoko; Watarai, Hitoshi

    2013-01-01

    We constructed an apparatus to measure the wavelength dispersion of the Faraday rotation in the visible region, and determined the Verdet constants of diamagnetic organic liquids, including aliphatic compounds, benzene derivatives, and naphthalene derivatives. These three groups were easily distinguished by the magnitudes of their Verdet constants. Based on the theory developed by Serber, we determined the enhancing effect of π*←π transitions on the visible-light Faraday rotation angles observed for aromatic compounds. Furthermore, we propose a novel approach for simultaneously observing Faraday rotation dispersion and natural optical rotatory dispersion.

  2. LiCaTb5(BO3)6: A new magneto-optical crystal promising as Faraday rotator

    Science.gov (United States)

    Li, R. K.; Wu, C. C.; Xia, M. J.

    2016-12-01

    A properly engineered new ortho-borate with composition of LiCaTb5(BO3)6 (LCTB), shows 55% enhancement of Verdet constant over the widely used magneto-optical TGG crystal. Centimetre level LCTB crystal can be grown from the self-flux LiCaBO3. Transmittance and magnetic measurements reveal that LCTB crystal is highly transparent between 500 and 1500 nm and is paramagnetic down to 2 K with a magnetic easy axis along the [001] direction. Faraday rotation measurements show that the Verdet constant along [001] direction of LCTB crystal is 227 (3) rad/Tm at 633 nm, in comparison to that of TGG crystal (146(2) rad/Tm) under the same measurement conditions. The above results indicate that the title compound can be a promising candidate as a new MO material with high performance in a Faraday isolator.

  3. Canonical Wnt/β-catenin signalling is essential for optic cup formation.

    Directory of Open Access Journals (Sweden)

    Anna-Carin Hägglund

    Full Text Available A multitude of signalling pathways are involved in the process of forming an eye. Here we demonstrate that β-catenin is essential for eye development as inactivation of β-catenin prior to cellular specification in the optic vesicle caused anophthalmia in mice. By achieving this early and tissue-specific β-catenin inactivation we find that retinal pigment epithelium (RPE commitment was blocked and eye development was arrested prior to optic cup formation due to a loss of canonical Wnt signalling in the dorsal optic vesicle. Thus, these results show that Wnt/β-catenin signalling is required earlier and play a more central role in eye development than previous studies have indicated. In our genetic model system a few RPE cells could escape β-catenin inactivation leading to the formation of a small optic rudiment. The optic rudiment contained several neural retinal cell classes surrounded by an RPE. Unlike the RPE cells, the neural retinal cells could be β-catenin-negative revealing that differentiation of the neural retinal cell classes is β-catenin-independent. Moreover, although dorsoventral patterning is initiated in the mutant optic vesicle, the neural retinal cells in the optic rudiment displayed almost exclusively ventral identity. Thus, β-catenin is required for optic cup formation, commitment to RPE cells and maintenance of dorsal identity of the retina.

  4. Surface-Enhanced Faraday Magneto-Optical Effect In Multilayer Films Containing Faraday-Active Metal%多层膜中法拉第磁光效应的增强

    Institute of Scientific and Technical Information of China (English)

    缪秀平

    2012-01-01

    运用传输矩阵的方法研究由法拉第旋光金属和电介质交替组成的多层膜的法拉第磁光效应.数值计算的结果显示,由于表面等离子的激励,在金属和电介质之间界面会出现很强的光局域性,法拉第旋转角和透射率在高频区都出现了共振峰.同时可通过调节多层膜的周期重叠数和法拉第旋光金属层的厚度来控制法拉第磁光特性.%The Faraday magneto-optical properties of periodic multilayer films made of alternating Faraday-active metal (M) and dielectric (D) materials are investigated. Calculations, Based on transfer matrix method, demonstrate that Faraday magnetic-optical rotation angle exhibits several resonant peaks with considerable transmittance in high-frequency region, due to effective excitation of surface plasmon polaritons in interfaces between metal and dielectric layers. As a consequence, the Faraday magnetic-optical properties can be controlled by varying the repetition number of film structure and the thickness of the magnetic layer.

  5. Magneto-optical Faraday rotation of semiconductor nanoparticles embedded in dielectric matrices.

    Science.gov (United States)

    Savchuk, Andriy I; Stolyarchuk, Ihor D; Makoviy, Vitaliy V; Savchuk, Oleksandr A

    2014-04-01

    Faraday rotation has been studied for CdS, CdTe, and CdS:Mn semiconductor nanoparticles synthesized by colloidal chemistry methods. Additionally these materials were prepared in a form of semiconductor nanoparticles embedded in polyvinyl alcohol films. Transmission electron microscopy and atomic force microscopy analyses served as confirmation of nanocrystallinity and estimation of the average size of the nanoparticles. Spectral dependence of the Faraday rotation for the studied nanocrystals and nanocomposites is correlated with a blueshift of the absorption edge due to the confinement effect in zero-dimensional structures. Faraday rotation spectra and their temperature behavior in Mn-doped nanocrystals demonstrates peculiarities, which are associated with s, p-d exchange interaction between Mn²⁺ ions and band carriers in diluted magnetic semiconductor nanostructures.

  6. Faraday色散光学滤波器的研究进展%The Research Advance of Faraday Dispersion Optical Filter

    Institute of Scientific and Technical Information of China (English)

    贾晓玲; 掌蕴东; 王骐

    2001-01-01

    本文综述了Faraday反常色散光学滤波器的国内外研究进展,并提出发展前景。%This paper summarized the international and domestic developmentof Faraday anomalous dispersion optical filters in detail. Meanwhile,the prospect of the optical filter was also analyzed.

  7. Compact all-fiber optical Faraday components using 65-wt%-terbium-doped fiber with a record Verdet constant of -32 rad/(Tm).

    Science.gov (United States)

    Sun, L; Jiang, S; Marciante, J R

    2010-06-07

    A compact all-fiber Faraday isolator and a Faraday mirror are demonstrated. At the core of each of these components is an all-fiber Faraday rotator made of a 4-cm-long, 65-wt%-terbium-doped silicate fiber. The effective Verdet constant of the terbium-doped fiber is measured to be -32 rad/(Tm), which is 27 x larger than that of silica fiber. This effective Verdet constant is the largest value measured to date in any fiber and is 83% of the Verdet constant of commercially available crystal used in bulk optics-based isolators. Combining the all-fiber Faraday rotator with fiber polarizers results in a fully fusion spliced all-fiber isolator whose isolation is measured to be 19 dB. Combining the all-fiber Faraday rotator with a fiber Bragg grating results in an all-fiber Faraday mirror that rotates the polarization state of the reflected light by 88 +/- 4 degrees .

  8. A Case Report of Unilateral Severe Visual Loss Along with Bilateral Optic Disc Cupping Secondary to Metastatic Brain Tumor

    Directory of Open Access Journals (Sweden)

    M Mahdavi

    2006-07-01

    Full Text Available Purpose: To report a case of unilateral severe visual loss and bilateral optic disc cupping secondary to brain metastasis of bronchogenic carcinoma Patient and findings: A 48 year-old woman presented with severe visual loss of left eye without redness or pain or any systemic findings .Clinical findings included decreased visual acuity of left eye to 4 m CF and (+3 positive Marcus-Gunn reflex .There was asymmetric optic disc cupping associated with visual field defect in left eye The neurologic investigations showed a secondary metastatic tumor in the brain from bronchogenic carcinoma. Conclusion: Before making a diagnosis of normal -tension glaucoma in asymmetric optic disc cupping and normal intraocular pressure, ophthalmologists should rule out neurologic defects and brain tumors.

  9. Concerted action of neuroepithelial basal shrinkage and active epithelial migration ensures efficient optic cup morphogenesis

    Science.gov (United States)

    Sidhaye, Jaydeep; Norden, Caren

    2017-01-01

    Organ formation is a multi-scale event that involves changes at the intracellular, cellular and tissue level. Organogenesis often starts with the formation of characteristically shaped organ precursors. However, the cellular mechanisms driving organ precursor formation are often not clear. Here, using zebrafish, we investigate the epithelial rearrangements responsible for the development of the hemispherical retinal neuroepithelium (RNE), a part of the optic cup. We show that in addition to basal shrinkage of RNE cells, active migration of connected epithelial cells into the RNE is a crucial player in its formation. This cellular movement is driven by progressive cell-matrix contacts and actively translocates prospective RNE cells to their correct location before they adopt neuroepithelial fate. Failure of this migration during neuroepithelium formation leads to ectopic determination of RNE cells and consequently impairs optic cup formation. Overall, this study illustrates how spatiotemporal coordination between morphogenic movements and fate determination critically influences organogenesis. DOI: http://dx.doi.org/10.7554/eLife.22689.001 PMID:28372636

  10. A method for eliminating Faraday rotation in cryostat windows in longitudinal magneto-optical Kerr effect measurements

    Energy Technology Data Exchange (ETDEWEB)

    Polewko-Klim, A., E-mail: anetapol@uwb.edu.pl; Uba, S.; Uba, L. [Institute of Informatics, University of Bialystok, Sosnowa 64, PL-15-887 Bialystok (Poland)

    2014-07-15

    A solution to the problem of disturbing effect of the background Faraday rotation in the cryostat windows on longitudinal magneto-optical Kerr effect (LMOKE) measured under vacuum conditions and/or at low temperatures is proposed. The method for eliminating the influence of Faraday rotation in cryostat windows is based on special arrangement of additional mirrors placed on sample holder. In this arrangement, the orientation of the cryostat window is perpendicular to the light beam direction and parallel to an external magnetic field generated by the H-frame electromagnet. The operation of the LMOKE magnetometer with the special sample holder based on polarization modulation technique with a photo-elastic modulator is theoretically analyzed with the use of Jones matrices, and formulas for evaluating of the actual Kerr rotation and ellipticity of the sample are derived. The feasibility of the method and good performance of the magnetometer is experimentally demonstrated for the LMOKE effect measured in Fe/Au multilayer structures. The influence of imperfect alignment of the magnetometer setup on the Kerr angles, as derived theoretically through the analytic model and verified experimentally, is examined and discussed.

  11. A method for eliminating Faraday rotation in cryostat windows in longitudinal magneto-optical Kerr effect measurements.

    Science.gov (United States)

    Polewko-Klim, A; Uba, S; Uba, L

    2014-07-01

    A solution to the problem of disturbing effect of the background Faraday rotation in the cryostat windows on longitudinal magneto-optical Kerr effect (LMOKE) measured under vacuum conditions and/or at low temperatures is proposed. The method for eliminating the influence of Faraday rotation in cryostat windows is based on special arrangement of additional mirrors placed on sample holder. In this arrangement, the orientation of the cryostat window is perpendicular to the light beam direction and parallel to an external magnetic field generated by the H-frame electromagnet. The operation of the LMOKE magnetometer with the special sample holder based on polarization modulation technique with a photo-elastic modulator is theoretically analyzed with the use of Jones matrices, and formulas for evaluating of the actual Kerr rotation and ellipticity of the sample are derived. The feasibility of the method and good performance of the magnetometer is experimentally demonstrated for the LMOKE effect measured in Fe/Au multilayer structures. The influence of imperfect alignment of the magnetometer setup on the Kerr angles, as derived theoretically through the analytic model and verified experimentally, is examined and discussed.

  12. Fiber-Optic Michelson Interferometer with Faraday Mirrors for Acoustic Sensing using a 3 x 3 Coupler and Symmetric Demodulation Scheme

    OpenAIRE

    Gartland, Peter Lanier

    2016-01-01

    For the past 40 years, acoustic sensing has been a major avenue for the growth of interfero- metric fiber-optic sensors. Fiber-optic acoustic sensors have found uses in military, commer- cial, and medical applications. An interferometric fiber-optic acoustic sensor is presented utilizing the Michelson interferometer configuration with Faraday mirrors to eliminate po- larization fading. A 3 X 3 coupler is used as the beamsplitting component, and a symmetric demodulation algorith...

  13. Ultra-narrow linewidth optical filter based on Faraday effect at isotope 87Rb 420 nm transitions

    Science.gov (United States)

    Bi, Gang; Kang, Jia; Fu, Jun; Ling, Li; Chen, Jingbiao

    2016-12-01

    An ultra-narrow linewidth optical filter with isotope 87Rb vapor at 420 nm, within the best waveband 400-500 nm for deep sea communication is achieved for the first time. The Faraday effect, circular dichroism, and nonlinear saturation techniques are utilized to narrow the bandwidth from previous 2.5 GHz to about 15 MHz level on the energy transition 5S1/2 → 6P3/2. By changing the temperature and magnetic field, the maximum transmission is obtained when the temperature and the magnetic field of the 87Rb cell are at 100 °C and 12 G. We discuss the varying influences of temperature, magnetic field, and pump power on the transmission of the atomic filter. The maximum single peak transmission at 5S1/2, F = 2 → 6P3/2, F‧ = 3 transition is 2.1% with a bandwidth of 17.8 MHz, and 1.9% at the 5S1/2, F = 2 → 6P3/2, F‧ = 2 , 3 (cross-over) transition with that of 14.2 MHz. The calculated equivalent noise bandwidth of this system is 32.5 MHz. Compared with the conventional Faraday anomalous dispersion optical filter, the bandwidth of our system is narrowed at least two orders of magnitude and is closer to the natural linewidth. This ultra-narrow linewidth filter has the potential to be applied to submarine communication or the pump laser in a four-level Rb-based active optical clock.

  14. High-sensitivity optical Faraday magnetometry with intracavity electromagnetically induced transparency

    Science.gov (United States)

    Zhang, Qiaolin; Sun, Hui; Fan, Shuangli; Guo, Hong

    2016-12-01

    We suggest a multiatom cavity quantum electrodynamics system for the detection of a weak magnetic field, based on Faraday rotation with intracavity electromagnetically induced transparency. Our study demonstrates that the collective coupling between the cavity modes and the atomic ensemble can be used to improve the sensitivity. With single-probe photon input, the sensitivity is inversely proportional to the number of atoms, and a sensitivity of 2.45 nT Hz-1/2 could be attained. With multiphoton measurement, our numerical calculations show that the magnetic field sensitivity can be improved to 105.6 aT Hz-1/2 with realistic experimental conditions.

  15. Filter Performance of a Cesium Faraday Optical Filter at 852 nm

    Institute of Scientific and Technical Information of China (English)

    掌蕴东; 贾晓玲; 毕勇; 马祖光; 王骐

    2002-01-01

    We have investigated a cesium Faraday filter at 852nm in relatively weak and strong magnetic fields, theoretically and experimentally. With a cesium cell of 0.02m length in an axial magnetic field of 0.06T, the line-centre operation has been achieved. The calculated peak transmission reached 99% with a full width at half maximum (FWHM) bandwidth of only 3.9 GHz. The measured FWHM bandwidth of the filter is 3.29 GHz, which is in general agreement with the theoretical result.

  16. Complete Stokes polarimetry of magneto-optical Faraday effect in a terbium gallium garnet crystal at cryogenic temperatures.

    Science.gov (United States)

    Majeed, Hassaan; Shaheen, Amrozia; Anwar, Muhammad Sabieh

    2013-10-21

    We report the complete determination of the polarization changes caused in linearly polarized incident light due to propagation in a magneto-optically active terbium gallium garnet (TGG) single crystal, at temperatures ranging from 6.3 to 300 K. A 28-fold increase in the Verdet constant of the TGG crystal is seen as its temperature decreases to 6.3 K. In contrast with polarimetry of light emerging from a Faraday material at room temperature, polarimetry at cryogenic temperatures cannot be carried out using the conventional fixed polarizer-analyzer technique because the assumption that ellipticity is negligible becomes increasingly invalid as temperature is lowered. It is shown that complete determination of light polarization in such a case requires the determination of its Stokes parameters, otherwise inaccurate measurements will result with negative implications for practical devices.

  17. Cavity-enhanced room-temperature high sensitivity optical Faraday magnetometry

    Science.gov (United States)

    Sun, Hui; Lei, Yaohua; Fan, Shuangli; Zhang, Qiaolin; Guo, Hong

    2017-01-01

    We propose a cavity QED system with two-photon Doppler-free configuration for weak magnetic field detection with high sensitivity at room temperature based on cavity electromagnetically induced transparency. Owing to the destructive interference induced by the control and driving fields, two transparency channels are opened. The Faraday rotation within two transparency channels can be used to detect weak magnetic field with high sensitivity at room temperature. The sensitivity with single photon and multiphoton probe inputs is analyzed. With single photon measurement, our numerical calculations demonstrate that the sensitivity with 3.8nT/√{Hz} and 6.4nT/√{Hz} could be achieved. When we measure the magnetic field with multiphoton input, the sensitivity can be improved to 7.7fT/√{Hz} and 25.6fT/√{Hz} under the realistic experimental conditions.

  18. 非青光眼性大视杯临床分析%Clinical characteristics of nonglaucomatous optic disc cupping

    Institute of Scientific and Technical Information of China (English)

    黄厚斌; 梅晓白; 魏世辉; 阴正勤

    2012-01-01

    Objective To analyze the etiology of nonglaucomatous optic disc cupping and the differentiation with glaucomatous optic disc cupping. Design Retrospective case series. Participants Twelve cases with 19 eyes of nonglaucomatous optic disc cupping. Methods The morphology of optic disc and clinical data of these cases were analyzed. Main Outcome Measures Etiology, morphological characteristics of optic disc and visual function. Results Of the 12 cases, four were with optic neuritis, one with Devic disease, one with Leber hereditary optic neuropathy, two with pituitary adenoma, one with cerebral hemorrhage in basal ganglia, one with ciliary artery obstruction and central retinal vein occlusion, one with central retinal artery occlusion, and one with optic nerve injuries. In all patients the optic cupping shows diffuse excavation or focal notch with pale rim. The visual field defect was corresponding to the primary diseases. Conclusions Both optic nerve diseases and retinal diseases can cause nonglaucomatous optic disc cupping. The key points to differentiate nonglaucomatous optic disc cupping with glaucomatous lie in the color of optic disc rim, notched disc and the correlation between visual field defect and disc appearance. (Ophthalmol CHN, 2012, 21: 306-309)Objective To analyze the etiology of nonglaucomatous optic disc cupping and the differentiation with glaucomatous optic disc cupping. Design Retrospective case series. Participants Twelve cases with 19 eyes of nonglaucomatous optic disc cupping. Methods The morphology of optic disc and clinical data of these cases were analyzed. Main Outcome Measures Etiology, morphological characteristics of optic disc and visual function. Results Of the 12 cases, four were with optic neuritis, one with Devic disease, one with Leber hereditary optic neuropathy, two with pituitary adenoma, one with cerebral hemorrhage in basal ganglia, one with ciliary artery obstruction and central retinal vein occlusion, one with central retinal

  19. Correlation between cup-to-disc ratio and cup/retrobulbar optic nerve diameter proportion assessed by high-resolution ultrasound in glaucomatous eyes

    Directory of Open Access Journals (Sweden)

    Wilian Silva Queiroz

    2013-10-01

    Full Text Available PURPOSE: To investigate the correlation between the measurements of the cup/retrobulbar optic nerve diameter (C/OND proportion obtained by high-resolution 20-MHz B-mode ultrasound (US and those of the cup/disc ratio (C/D obtained by fundus biomicroscopy (BIO and optical coherence tomography (OCT. METHODS: Thirty eyes of 15 glaucomatous patients with any C/D proportion were studied. All patients underwent examination of the vertical C/D by BIO with a 78D lens and time-domain OCT analysis, as well as the vertical C/OND proportion using 20-MHz US measurements. All data were analyzed by correlation and agreement tests. RESULTS: The Spearman test showed a strong correlation between C/D results obtained by BIO and the measurements of C/OND (US (r=0.788, p<0.0001, and with C/D obtained by OCT (r=0.8529, p<0.0001. However, comparison of C/D results obtained with OCT to those obtained by with C/OND (US showed only a moderate correlation (r=0.6727, p<0.0001. Bland-Altman analysis did not show good agreement between C/D (BIO and C/OND (US. CONCLUSIONS: The results demonstrate that B-mode ultrasound examination with a 20 MHz probe can be a good additional method for the evaluation of the C/D ratio in glaucomatous patients, and may be considered as an alternative gross tool in glaucomatous patients with optic media opacities.

  20. Faraday imaging at high temperatures

    Science.gov (United States)

    Hackel, Lloyd A.; Reichert, Patrick

    1997-01-01

    A Faraday filter rejects background light from self-luminous thermal objects, but transmits laser light at the passband wavelength, thus providing an ultra-narrow optical bandpass filter. The filter preserves images so a camera looking through a Faraday filter at a hot target illuminated by a laser will not see the thermal radiation but will see the laser radiation. Faraday filters are useful for monitoring or inspecting the uranium separator chamber in an atomic vapor laser isotope separation process. Other uses include viewing welds, furnaces, plasma jets, combustion chambers, and other high temperature objects. These filters are can be produced at many discrete wavelengths. A Faraday filter consists of a pair of crossed polarizers on either side of a heated vapor cell mounted inside a solenoid.

  1. Short Drive Mechanism for Faraday Cup

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    ShortDriveMechanismforFaradayCup¥ZhangGongXiang;JiangFakuiandLouMeilingThenewECRsourcebeamlinewhichisunderconstructionneedsth...

  2. Active imaging system with Faraday filter

    Science.gov (United States)

    Snyder, James J.

    1993-01-01

    An active imaging system has a low to medium powered laser transmitter and receiver wherein the receiver includes a Faraday filter with an ultranarrow optical bandpass and a bare (nonintensified) CCD camera. The laser is locked in the vicinity of the passband of the Faraday filter. The system has high sensitivity to the laser illumination while eliminating solar background.

  3. Distinct cis-acting regions control six6 expression during eye field and optic cup stages of eye formation.

    Science.gov (United States)

    Ledford, Kelley L; Martinez-De Luna, Reyna I; Theisen, Matthew A; Rawlins, Karisa D; Viczian, Andrea S; Zuber, Michael E

    2017-06-15

    The eye field transcription factor, Six6, is essential for both the early (specification and proliferative growth) phase of eye formation, as well as for normal retinal progenitor cell differentiation. While genomic regions driving six6 optic cup expression have been described, the sequences controlling eye field and optic vesicle expression are unknown. Two evolutionary conserved regions 5' and a third 3' to the six6 coding region were identified, and together they faithfully replicate the endogenous X. laevis six6 expression pattern. Transgenic lines were generated and used to determine the onset and expression patterns controlled by the regulatory regions. The conserved 3' region was necessary and sufficient for eye field and optic vesicle expression. In contrast, the two conserved enhancer regions located 5' of the coding sequence were required together for normal optic cup and mature retinal expression. Gain-of-function experiments indicate endogenous six6 and GFP expression in F1 transgenic embryos are similarly regulated in response to candidate trans-acting factors. Importantly, CRISPR/CAS9-mediated deletion of the 3' eye field/optic vesicle enhancer in X. laevis, resulted in a reduction in optic vesicle size. These results identify the cis-acting regions, demonstrate the modular nature of the elements controlling early versus late retinal expression, and identify potential regulators of six6 expression during the early stages of eye formation. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Development of integrated damage detection system for international America's Cup class yacht structures using a fiber optic distributed sensor

    Science.gov (United States)

    Akiyoshi, Shimada; Naruse, Hiroshi; Uzawa, Kyoshi; Murayama, Hideaki; Kageyama, Kazuro

    2000-06-01

    We constructed a new health monitoring system to detect damage using a fiber optic distributed sensor, namely a Brillouin optical time domain reflectometer (BOTDR), and installed it in International America's Cup Class (IACC) yachts, the Japanese entry in America's Cup 2000. IACC yachts are designed to be as fast as possible, so it is essential that they are lightweight and encounter minimum water resistance. Advanced composite sandwich structures, made with carbon fiber reinforced plastic (CFRP) skins and a honeycomb core, are used to achieve the lightweight structure. Yacht structure designs push the strength of the materials to their limit and so it is important to detect highly stressed or damaged regions that might cause a catastrophic fracture. The BOTDR measures changes in the Brillouin frequency shift caused by distributed strain along one optical fiber. We undertook two experiments: a pulling test and a four point bending test on a composite beam. The former showed that no slippage occurred between the optical fiber glass and its coating. The latter confirmed that a debonding between the skin and the core of 300 mm length could be found with the BOTDR. Next we examined the effectiveness with which this system can assess the structural integrity of IACC yachts. The results show that our system has the potential for use as a damage detection system for smart structures.

  5. Diode laser using narrow bandwidth interference filter at 852 nm and its application in Faraday anomalous dispersion optical filter

    Science.gov (United States)

    Jiang, Zhaojie; Zhou, Qi; Tao, Zhiming; Zhang, Xiaogang; Zhang, Shengnan; Zhu, Chuanwen; Lin, Pingwei; Chen, Jingbiao

    2016-08-01

    We demonstrate an 852-nm external cavity diode laser (ECDL) system whose wavelength is mainly determined by an interference filter instead of other wavelength selective elements. The Lorentzian linewidth measured by the heterodyne beating between two identical lasers is 28.3 kHz. Moreover, we test the application of the ECDL in the Faraday atomic filter. Besides saturated absorption spectrum, the transmission spectrum of the Faraday atomic filter at 852 nm is measured by using the ECDL. This interference filter ECDL method can also be extended to other wavelengths and widen the application range of diode laser. Project supported by the National Natural Science Foundation of China (Grant No. 91436210) and the International Science and Technology Cooperation Program of China (Grant No. 2010DFR10900).

  6. Accurate Jones Matrix of the Practical Faraday Rotator

    Institute of Scientific and Technical Information of China (English)

    王林斗; 祝昇翔; 李玉峰; 邢文烈; 魏景芝

    2003-01-01

    The Jones matrix of practical Faraday rotators is often used in the engineering calculation of non-reciprocal optical field. Nevertheless, only the approximate Jones matrix of practical Faraday rotators has been presented by now. Based on the theory of polarized light, this paper presents the accurate Jones matrix of practical Faraday rotators. In addition, an experiment has been carried out to verify the validity of the accurate Jones matrix. This matrix accurately describes the optical characteristics of practical Faraday rotators, including rotation, loss and depolarization of the polarized light. The accurate Jones matrix can be used to obtain the accurate results for the practical Faraday rotator to transform the polarized light, which paves the way for the accurate analysis and calculation of practical Faraday rotators in relevant engineering applications.

  7. Non-reciprocity of Faraday rotation in gyrotropic crystals

    OpenAIRE

    Vlokh R.; Adamenko D.

    2008-01-01

    It is shown that, under the conditions of coexisting natural optical activity and non-zero linear optical birefringence, reversal of the light wave vector sign can result in changing angle of Faraday rotation.

  8. Faraday isolator based on TSAG crystal for high power lasers.

    Science.gov (United States)

    Mironov, E A; Palashov, O V

    2014-09-22

    A Faraday isolator based on a new magneto-optical medium, TSAG (terbium scandium aluminum garnet) crystal, has been constructed and investigated experimentally. The device provides an isolation ratio of more than 30 dB at 500 W laser power. It is shown that this medium can be used in Faraday isolators for kilowatt-level laser powers.

  9. Ultrafast Faraday Rotation of Slow Light

    Science.gov (United States)

    Musorin, A. I.; Sharipova, M. I.; Dolgova, T. V.; Inoue, M.; Fedyanin, A. A.

    2016-08-01

    The active control of optical signals in the time domain is what science and technology demand in fast all-optical information processing. Nanostructured materials can modify the group velocity and slow the light down, as the artificial light dispersion emerges. We observe the ultrafast temporal behavior of the Faraday rotation within a single femtosecond laser pulse under conditions of slow light in a one-dimensional magnetophotonic crystal. The Faraday effect changes by 20% over the time of 150 fs. This might be applicable to the fast control of light in high-capacity photonic devices.

  10. Faraday caustics: Singularities in the Faraday spectrum and their utility as probes of magnetic field properties

    CERN Document Server

    Bell, M R; Enßlin, T A

    2011-01-01

    We describe singularities in the distribution of polarized intensity as a function of Faraday depth (i.e. the Faraday spectrum) that arise due to line of sight (LOS) magnetic field reversals. We call these features Faraday caustics due to their similarity to optical caustics. They appear sharply spiked in the Faraday spectrum with a tail that extends to one side. The direction in which the tail extends depends on the way in which the LOS magnetic field reversal occurs (either changing from oncoming to retreating or vice versa). We describe how surfaces of Faraday caustics relate to boundaries between regions where the LOS magnetic field has opposite polarity. Examples from simulations of the polarized synchrotron emission from the Milky Way are provided. We derive the probability or luminosity distribution of Faraday caustics produced in a Gaussian magnetic field distribution as a function of their strength, F, and find that for strong Faraday caustics P(F) ~ F^(-3). If fully resolved, this distribution is al...

  11. Real time Faraday spectrometer

    Science.gov (United States)

    Smith, Jr., Tommy E.; Struve, Kenneth W.; Colella, Nicholas J.

    1991-01-01

    This invention uses a dipole magnet to bend the path of a charged particle beam. As the deflected particles exit the magnet, they are spatially dispersed in the bend-plane of the magnet according to their respective momenta and pass to a plurality of chambers having Faraday probes positioned therein. Both the current and energy distribution of the particles is then determined by the non-intersecting Faraday probes located along the chambers. The Faraday probes are magnetically isolated from each other by thin metal walls of the chambers, effectively providing real time current-versus-energy particle measurements.

  12. Development of the ciliary body: morphological changes in the distal portion of the optic cup in the human.

    Science.gov (United States)

    Peces-Peña, M D; de la Cuadra-Blanco, C; Vicente, A; Mérida-Velasco, J R

    2013-01-01

    This study seeks to determine the main events that occur in the development of the ciliary body (CB) in the 5-14th week of development. The CB develops from the distal portion of the optic cup (OC) and the neighboring mesenchyme. During the 5th week of development, 4 zones were observed in the distal portion of the OC: in zone 1, the epithelia of the outer and inner layers of the OC came into contact. This contact coincided with the appearance of mainly apical granule pigments. This zone corresponded to the anlage of the epithelial layers of the CB. In zone 2, the cells surrounded the marginal sinus and contained scarce pigment granules and nuclei in the basal position. This zone corresponded to the anlage of the iris. Zone 3 was triangular in shape and its vertex ran towards the marginal sinus and corresponded to common cell progenitors. Zone 4 corresponded to the retinal pigment epithelium anlage and the neural retina anlage. We determined the onset of the stroma and the ciliary muscle anlage at the end of the 7th week. In the 13-14th week, we observed the anlage of the orbicularis ciliaris (pars plana of the CB) and corona ciliaris (pars plicata of the CB), in addition to the anlage of the ciliary muscle. Our study, therefore, establishes a precise timetable of the development of the CB.

  13. Michael Faraday, media man.

    Science.gov (United States)

    Fara, Patricia

    2006-03-01

    Michael Faraday was an enthusiastic portrait collector, and he welcomed the invention of photography not only as a possible means of recording observations accurately, but also as a method for advertising science and its practitioners. This article (which is part of the Science in the Industrial Revolution series) shows that like many eminent scientists, Faraday took advantage of the burgeoning Victorian media industry by posing in various roles.

  14. The Faraday effect revisited: General theory

    DEFF Research Database (Denmark)

    Cornean, Horia Decebal; Nenciu, Gheorghe; Pedersen, Thomas Garm

    This paper is the first in a series revisiting the Faraday effect, or more generally, the theory of electronic quantum transport/optical response in bulk media in the presence of a constant magnetic field. The independent electron approximation is assumed. For free electrons, the transverse...

  15. The Faraday effect revisited: General theory

    DEFF Research Database (Denmark)

    Cornean, Horia Decebal; Nenciu, Gheorghe; Pedersen, Thomas Garm

    2006-01-01

    This paper is the first in a series revisiting the Faraday effect, or more generally, the theory of electronic quantum transport/optical response in bulk media in the presence of a constant magnetic field. The independent electron approximation is assumed. At zero temperature and zero frequency...

  16. Venture Cup

    OpenAIRE

    Hulshoff, Selma

    2013-01-01

    Abstract Venture Cup began as a small project with a financial purpose mixed with a societal goal. In 2000 when the project could not fulfil the financial goal of being a feeding structure of new client enterprises, it was passed on. This resulted in a structured organisation which has become a cultural change agent in the Danish field of Entrepreneurship. The life cycle process of a cultural change organisation and the influencing factors are the interest of this thesis. The stakeholders...

  17. Faraday effect in hybrid magneto-plasmonic photonic crystals.

    Science.gov (United States)

    Caballero, B; García-Martín, A; Cuevas, J C

    2015-08-24

    We present a theoretical study of the Faraday effect in hybrid magneto-plasmonic crystals that consist of Au-Co-Au perforated membranes with a periodic array of sub-wavelength holes. We show that in these hybrid systems the interplay between the extraordinary optical transmission and the magneto-optical activity leads to a resonant enhancement of the Faraday rotation, as compared to purely ferromagnetic membranes. In particular, we determine the geometrical parameters for which this enhancement is optimized and show that the inclusion of a noble metal like Au dramatically increases the Faraday rotation over a broad bandwidth. Moreover, we show that the analysis of the Faraday rotation in these periodically perforated membranes provides a further insight into the origin of the extraordinary optical transmission.

  18. Faraday rotation assisted by linearly polarized light

    Science.gov (United States)

    Choi, Jai Min; Kim, Jang Myun; Cho, D.

    2007-11-01

    We demonstrate a type of chiral effect of an atomic medium. Polarization rotation of a probe beam is observed only when both a magnetic field and a linearly polarized coupling beam are present. We compare it with other chiral effects like optical activity, the Faraday effect, and the optically induced Faraday effect from the viewpoint of spatial inversion and time reversal transformations. As a theoretical model we consider a five-level configuration involving the cesium D2 transition. We use spin-polarized cold cesium atoms trapped in a magneto-optical trap to measure the polarization rotation versus probe detuning. The result shows reasonable agreement with a calculation from the master equation of the five-level configuration.

  19. Following Michael Faraday's Footprints

    Science.gov (United States)

    Galeano, Javier

    2011-01-01

    Last fall I had the good fortune of receiving financial support to shoot a documentary about Michael Faraday. I took the opportunity to learn more about this great experimentalist and to visit the highlights of places in his life. In this paper, I would like to share a list and description of some of the most remarkable places in London suitable…

  20. The Faraday effect revisited

    DEFF Research Database (Denmark)

    Cornean, Horia; Nenciu, Gheorghe

    2009-01-01

    This paper is the second in a series revisiting the (effect of) Faraday rotation. We formulate and prove the thermodynamic limit for the transverse electric conductivity of Bloch electrons, as well as for the Verdet constant. The main mathematical tool is a regularized magnetic and geometric...

  1. SMAP Faraday Rotation

    Science.gov (United States)

    Le Vine, David

    2016-01-01

    Faraday rotation is a change in the polarization as signal propagates through the ionosphere. At L-band it is necessary to correct for this change and measurements are made on the spacecraft of the rotation angle. These figures show that there is good agreement between the SMAP measurements (blue) and predictions based on models (red).

  2. Optic Disc Change during Childhood Myopic Shift: Comparison between Eyes with an Enlarged Cup-To-Disc Ratio and Childhood Glaucoma Compared to Normal Myopic Eyes.

    Directory of Open Access Journals (Sweden)

    Hae-Young Lopilly Park

    Full Text Available Progressive disc tilting and the development or enlargement of peripapillary atrophy (PPA are observed during a myopic shift in children. This could be related to the changes around the optic nerve head during eyeball elongation. If the biomechanical properties at or around the optic nerve head are changed after exposure to elevated intraocular pressure (IOP in glaucoma eyes, different response of the disc tilting and PPA changes could take place during eyeball elongation by myopic shift. On the basis of this background, the aim of this study was to compare the morphological changes in the optic disc induced by a myopic shift during childhood between normal control eyes, eyes from disc suspects with an enlarged cup-to-disc ratio (CDR, and eyes with childhood glaucoma.Total of 82 eyes from 82 subjects younger than 14 years of age were included in the study. Serial disc photographs were classified into one of two groups: eyes with an optic nerve head (ONH or peripapillary atrophy (PPA change or without an ONH/PPA change. Using ImageJ software, the outlines of the optic disc and PPA were plotted, and the vertical disc diameter (VDD, horizontal disc diameter (HDD, and maximum PPA width (PPW were measured. The changes in the ratios of these parameters and the relationships between the degree of myopic shift or the ONH/PPA change were analyzed.Twenty-five eyes with normal optic disc appearance, 36 eyes with enlarged cup-to-disc ratio, and 21 eyes of glaucoma patients were analyzed. The initial intraocular pressure (IOP at diagnosis was significantly different among the groups (P<0.001. The degree of myopic shift during follow-up period was not significantly different among the groups (P=0.612. However, the changes in the HDD/VDD and PPW/VDD ratios were significantly greater in the disc suspect group and significantly smaller in the glaucoma group. Among the 42 eyes with an ONH/PPA change, 16 (38.1% were from the normal control group, 24 (57.1% were

  3. Nonreciprocal plasmonics enables giant enhancement of thin-film Faraday rotation.

    Science.gov (United States)

    Chin, Jessie Yao; Steinle, Tobias; Wehlus, Thomas; Dregely, Daniel; Weiss, Thomas; Belotelov, Vladimir I; Stritzker, Bernd; Giessen, Harald

    2013-01-01

    Light propagation is usually reciprocal. However, a static magnetic field along the propagation direction can break the time-reversal symmetry in the presence of magneto-optical materials. The Faraday effect in magneto-optical materials rotates the polarization plane of light, and when light travels backward the polarization is further rotated. This is applied in optical isolators, which are of crucial importance in optical systems. Faraday isolators are typically bulky due to the weak Faraday effect of available magneto-optical materials. The growing research endeavour in integrated optics demands thin-film Faraday rotators and enhancement of the Faraday effect. Here, we report significant enhancement of Faraday rotation by hybridizing plasmonics with magneto-optics. By fabricating plasmonic nanostructures on laser-deposited magneto-optical thin films, Faraday rotation is enhanced by one order of magnitude in our experiment, while high transparency is maintained. We elucidate the enhanced Faraday effect by the interplay between plasmons and different photonic waveguide modes in our system.

  4. Beam dumps, stoppers and Faraday cups at the SLC

    Energy Technology Data Exchange (ETDEWEB)

    Walz, D.R.; McFarlane, A.; Lewandowski, E.

    1989-04-01

    This presentation features most of the beam dumps and stoppers necessary to absorb and dissipate SLC e/sup +-/ beams with transverse sizes from several tens to a few hundred microns (..mu..m). Solutions are based on electromagnetic cascade shower calculations for N = 5 /times/ 10/sup 10/ e/bunch and momenta ranging from 1.2 GeV/c in the damping ring transport systems to 50 GeV/c in the arcs matching sections and the Final Focus region. 3 refs., 2 figs.

  5. Mobile Phone Faraday Cage

    CERN Document Server

    French, M M J

    2011-01-01

    A Faraday cage is an interesting physics phenomena where an electromagnetic wave can be excluded from a volume of space by enclosure with an electrically conducting material. The practical application of this in the classroom is to block the signal to a mobile phone by enclosing it in a metal can! The background of the physics behind this is described in some detail followed by a explanation of some demonstrations and experiments which I have used.

  6. Michael Faraday vs. the Spiritualists

    Science.gov (United States)

    Hirshfeld, Alan

    2006-12-01

    In the 1850s, renowned physicist Michael Faraday launched a public campaign against pseudoscience and spiritualism, which were rampant in England at the time. Faraday objected especially to claims that electrical or magnetic forces were responsible for paranormal phenomena, such as table-spinning and communication with the dead. Using scientific methods, Faraday unmasked the deceptions of spiritualists, clairvoyants and mediums and also laid bare the credulity of a public ill-educated in science. Despite his efforts, Victorian society's fascination with the paranormal swelled. Faraday's debacle anticipates current controversies about public science education and the interface between science and religion. This episode is one of many described in the new biography, The Electric Life of Michael Faraday (Walker & Co.), which chronicles Faraday's discoveries and his unlikely rise from poverty to the pinnacle of the English science establishment.

  7. Micro-position sensor using faraday effect

    Science.gov (United States)

    McElfresh, Michael; Lucas, Matthew; Silveira, Joseph P.; Groves, Scott E.

    2007-02-27

    A micro-position sensor and sensing system using the Faraday Effect. The sensor uses a permanent magnet to provide a magnetic field, and a magneto-optic material positioned in the magnetic field for rotating the plane of polarization of polarized light transmitted through the magneto-optic material. The magnet is independently movable relative to the magneto-optic material so as to rotate the plane of polarization of the polarized light as a function of the relative position of the magnet. In this manner, the position of the magnet relative to the magneto-optic material may be determined from the rotated polarized light. The sensing system also includes a light source, such as a laser or LED, for producing polarized light, and an optical fiber which is connected to the light source and to the magneto-optic material at a sensing end of the optical fiber. Processing electronics, such as a polarimeter, are also provided for determining the Faraday rotation of the plane of polarization of the back-reflected polarized light to determine the position of the magnet relative to the sensing end of the optical fiber.

  8. Faraday rotation measures in 20 AGN jets at parsec scale

    Directory of Open Access Journals (Sweden)

    Kravchenko Evgeniya V.

    2013-12-01

    Full Text Available We present multi wavelength parsec-scale Faraday rotation measure properties of twenty active galactic nuclei, observed with the Very Long Baseline Array simultaneously at 1.4, 1.6, 2.2, 2.4, 4.6, 5.0, 8.1, 8.4 and 15.4 GHz in the full polarization mode. For the observed sources we construct Faraday rotation measure and Faraday-corrected linear polarization maps. Direction of electrical field in the optically thick core regions confirms bimodal distribution. No significant changes of a Faraday rotation measure transverse to the jet direction are found in any of the observed sources. We propose a new magnetic field spatial geometry reconstruction method based on core shift measurements. This technique is applied to the quasar 1004+141. Results indicate an existence of a large scale poloidal magnetic field in the jet of 1004+141.

  9. Solar Probe Cup - Demonstrated Laboratory Performance

    Science.gov (United States)

    Case, A. W.; Kasper, J. C.; Korreck, K. E.; Stevens, M. L.; Larson, D. E.; Wright, K. H., Jr.; Gallagher, D. L.; Whittlesey, P. L.

    2016-12-01

    The Solar Probe Cup (SPC) is a Faraday Cup instrument that will fly on the Solar Probe Plus (SPP) spacecraft, orbiting the Sun as close as 9.86 solar radii from the center of the Sun. The SPC instrument is designed to measure the thermal solar wind plasma (protons, alphas, and electrons) that will be encountered throughout its close encounter with the Sun. Due to the solar wind flow being primarily radial, the SPC instrument is pointed directly at the Sun, resulting in an extreme thermal environment that must be tolerated throughout the primary data collection phase. Laboratory testing has been performed over the past 6 months to demonstrate the instrument's performance relative to its requirements, and to characterize the measurements over the expected thermal range. This presentation will demonstrate the performance of the instrument as measured in the lab, describe the operational configurations planned for flight, and discuss the data products that will be created.

  10. A novel Cs-(129)Xe atomic spin gyroscope with closed-loop Faraday modulation.

    Science.gov (United States)

    Fang, Jiancheng; Wan, Shuangai; Qin, Jie; Zhang, Chen; Quan, Wei; Yuan, Heng; Dong, Haifeng

    2013-08-01

    We report a novel Cs-(129)Xe atomic spin gyroscope (ASG) with closed-loop Faraday modulation method. This ASG requires approximately 30 min to start-up and 110 °C to operate. A closed-loop Faraday modulation method for measurement of the optical rotation was used in this ASG. This method uses an additional Faraday modulator to suppress the laser intensity fluctuation and Faraday modulator thermal induced fluctuation. We theoretically and experimentally validate this method in the Cs-(129)Xe ASG and achieved a bias stability of approximately 3.25 °∕h.

  11. Faraday rotation dispersion microscopy imaging of diamagnetic and chiral liquids with pulsed magnetic field.

    Science.gov (United States)

    Suwa, Masayori; Nakano, Yusuke; Tsukahara, Satoshi; Watarai, Hitoshi

    2013-05-21

    We have constructed an experimental setup for Faraday rotation dispersion imaging and demonstrated the performance of a novel imaging principle. By using a pulsed magnetic field and a polarized light synchronized to the magnetic field, quantitative Faraday rotation images of diamagnetic organic liquids in glass capillaries were observed. Nonaromatic hydrocarbons, benzene derivatives, and naphthalene derivatives were clearly distinguished by the Faraday rotation images due to the difference in Verdet constants. From the wavelength dispersion of the Faraday rotation images in the visible region, it was found that the resonance wavelength in the UV region, which was estimated based on the Faraday B-term, could be used as characteristic parameters for the imaging of the liquids. Furthermore, simultaneous acquisition of Faraday rotation image and natural optical rotation image was demonstrated for chiral organic liquids.

  12. 视盘的有效评估:与杯盘比的对比%Valid estimation of the optic disc:the case against using cup/disc ratio

    Institute of Scientific and Technical Information of China (English)

    魏红; Camila Zangalli; George L.Spaeth

    2011-01-01

    青光眼是一种以进行性视盘变化和视野损失为特征的眼压相关性疾病.杯盘比在过去40a来都是评价视盘青光眼性改变的标准方法.然而我们却发现是一些小视盘的患者有典型青光眼性视野损失,而一些大视盘的患者却没有视野损失.杯盘比的检查效力和可重复性都低于一些新的检查方法.视盘损伤可能度分级(DDLS)是一种衡量视盘盘沿面积、并且校正了视盘大小等影响因素的新型视盘评价方法.DDLS也许是评价青光眼视盘的更为优化的方法.%·Glaucoma is a kind of progressive disease characterized by distinctive defects of optic disc cupping and visual field loss associated with or without intraocular pressure elevated.The cup/disc ratio is the standard way to describe the optic disc in the past 40 years.But the fact is that there were cases in which glaucomatous visual field loss was associated with a small cup ,and cases in which visual field loss was not present even though the cup was large.The cup/disc ratio is less valid and reproducible than new methods.The Disc Damage Likelihood Scale (DDLS),which is based on the appearance of the neuroretinal rim of the optic disc,corrected for the disc diameter,may be a better system to evaluate the optic disc.

  13. Fabry-Perot enhanced Faraday rotation in graphene.

    Science.gov (United States)

    Ubrig, Nicolas; Crassee, Iris; Levallois, Julien; Nedoliuk, Ievgeniia O; Fromm, Felix; Kaiser, Michl; Seyller, Thomas; Kuzmenko, Alexey B

    2013-10-21

    We demonstrate that giant Faraday rotation in graphene in the terahertz range due to the cyclotron resonance is further increased by constructive Fabry-Perot interference in the supporting substrate. Simultaneously, an enhanced total transmission is achieved, making this effect doubly advantageous for graphene-based magneto-optical applications. As an example, we present far-infrared spectra of epitaxial multilayer graphene grown on the C-face of 6H-SiC, where the interference fringes are spectrally resolved and a Faraday rotation up to 0.15 radians (9°) is attained. Further, we discuss and compare other ways to increase the Faraday rotation using the principle of an optical cavity.

  14. Growth, Faraday and inverse Faraday characteristics of Tb2Ti2O7 crystal.

    Science.gov (United States)

    Guo, Feiyun; Sun, Yilin; Yang, Xiongsheng; Chen, Xin; Zhao, Bin; Zhuang, Naifeng; Chen, Jianzhong

    2016-03-21

    Tb2Ti2O7 (TTO) single crystal with dimensions of 20 × 20 × 16 mm3 was grown by the Czochralski method. Rietveld structure refinement of X-ray diffraction (XRD) data confirms that the compound crystallizes in the cubic system with pyrochlore structure. Transmission spectra, Magnetic circular dichroism (MCD) spectra, Faraday and inverse Faraday characteristics of TTO crystal have been measured and analyzed in detail. The results demonstrate that TTO crystal has high transmittance at 700-1400 nm waveband and a larger Verdat constant than that of TGG reported. Magnetic circular dichroism (MCD) spectra showed that the 4f→4f transitions of Tb3+ have significant contributions to the magneto-optical activity (MOA). In the time-resolved pump-probe spectroscopy, the rotation signals of the probe beam based on the inverse Faraday effect in magneto-optical crystal were observed at zero time delay, the full width at half maximum of the rotation and ellipticity signals can be as fast as ~500 fs, which indicates that TTO crystal can be a promising material for ultrafast all-optical magnetic switching.

  15. Microscopic Faraday rotation measurement system using pulsed magnetic fields.

    Science.gov (United States)

    Egami, Shigeki; Watarai, Hitoshi

    2009-09-01

    Microscopic Faraday rotation measurement system using a pulsed magnetic field has been constructed, which can be applied to micron sized diamagnetic and paramagnetic materials. A pulsed magnetic coil could generate a maximum magnetic flux density of about 12 T. The performance of the microscopic Faraday rotation apparatus was demonstrated by the measurement of the Verdet constant V of a polystyrene particle, after the calibration of the pulsed magnetic flux density using a glass plate as a standard material. Also, the magneto-optical rotation dispersion of some diamagnetic substances have been measured and analyzed with V=alambda(-2)+b. The values of a and b were compared to their magnetic susceptibilities.

  16. Permanent magnets for Faraday rotators inspired by the design of the magic sphere.

    Science.gov (United States)

    Trénec, Gérard; Volondat, William; Cugat, Orphée; Vigué, Jacques

    2011-08-20

    Faraday polarization rotators are commonly used in laser experiments. Most Faraday materials have a nonnegligible absorption, which is a limiting factor for high power laser optical isolators or for intracavity optical diodes. By using a stronger magnetic field and a shorter length of Faraday material, one can obtain the same polarization rotation and a reduced absorption. In this paper, we describe two permanent magnet arrangements that are easy to build and produce magnetic fields up to 1.7 T, substantially more than commonly used. The field homogeneity is largely sufficient for a 30 dB isolation ratio. We finally discuss the prospects for producing even larger fields with permanent magnets.

  17. FARADAY PLASMA CURRENT SENSOR WITH COMPENSATION FOR RECIPROCAL BIREFRINGENCE INDUCED BY MECHANICALPERTURBATIONS

    Directory of Open Access Journals (Sweden)

    Y. O. Barmenkov

    2003-07-01

    Full Text Available A Faraday fiber-optic current sensor was employed to measure the tokamak plasma current. In order todecrease the influence of mechanical perturbations on the sensor sensitivity, a two-pass optical scheme witha variable Faraday mirror at the fiber end is proposed. A decrease, by two orders of magnitude, in theinfluence of the linear birefringence produced by an external piezoceramic fiber modulator was experimentallyobserved.

  18. Three-Cup Chicken

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Ingredents:500 grams chicken legs,100 grams(about one tea cup)rice wine,50 grams(a small tea cup)sesame oil,50grams refined soy sauce,25 grams white sugar,10grams oyster sauce,chopped scallions,ginger root,garlic,and some hot chili peppers

  19. Rotary cup slurry atomization

    Science.gov (United States)

    Sommer, H. T.; Marnicio, R. J.

    1983-06-01

    The theory of a two-phase flow in a rotating cup atomizer is described. The analysis considers the separation of the solid and liquid media thus realistically modeling the flow of two layers along the inner cup wall: a slurry of increasing solids concentration and a supernatent liquid layer. The analysis is based on the earlier work of Hinze and Milborn (1950) which addressed the flow within a rotary cup for a homogeneous liquid. The superimposition of a settling velocity under conditions of high centrifugal acceleration permits the extended analysis of the separation of the two phases. Appropriate boundary conditions have been applied to the film's free surface and the cup wall and to match the flow characteristics at the liquid-slurry interface. The changing slurry viscosity, increasing nonlinearly with growing solid loading, was also considered. A parameter study illustrates the potential for a cup design to provide optimal slurry and liquid film thicknesses for effective atomization.

  20. NDC-IVM: An automatic segmentation of optic disc and cup region from medical images for glaucoma detection

    Directory of Open Access Journals (Sweden)

    Umarani Balakrishnan

    2017-05-01

    Full Text Available Glaucoma is an eye disease that usually occurs with the increased Intra-Ocular Pressure (IOP, which damages the vision of eyes. So, detecting and classifying Glaucoma is an important and demanding task in recent days. For this purpose, some of the clustering and segmentation techniques are proposed in the existing works. But, it has some drawbacks that include inefficient, inaccurate and estimates only the affected area. In order to solve these issues, a Neighboring Differential Clustering (NDC — Intensity Variation Masking (IVM are proposed in this paper. The main intention of this work is to extract and diagnose the abnormal retinal image by identifying the optic disc. This work includes three stages such as, preprocessing, clustering and segmentation. At first, the given retinal image is preprocessed by using the Gaussian Mask Updated (GMU model for eliminating the noise and improving the quality of the image. Then, the cluster is formed by extracting the threshold and patterns with the help of NDC technique. In the segmentation stage, the weight is calculated for pixel matching and ROI extraction by using the proposed IVM method. Here, the novelty is presented in the clustering and segmentation processes by developing NDC and IVM algorithms for accurate Glaucoma identification. In experiments, the results of both existing and proposed techniques are evaluated in terms of sensitivity, specificity, accuracy, Hausdorff distance, Jaccard and dice metrics.

  1. Faraday Rotation for Electron Beams Composed of Vortex Modes

    CERN Document Server

    Greenshields, Colin; Franke-Arnold, Sonja

    2012-01-01

    Propagating vortex states, which carry orbital angular momentum (OAM), are well known in optics and have recently been demonstrated for electrons. While many analogies exist between photonic and electron vortex states, electron vortices in addition possess an orbital magnetic moment. We show here that propagation of electrons in a superposition of OAM states through a longitudinal magnetic field produces an analogue to optical Faraday rotation. In the optical domain, Faraday rotation is observed for polarisation, but not for superpositions of OAM states. The rotation we predict arises from the additional phase accumulated by the electron as it propagates in the presence of an external magnetic field. We propose an experiment in which this rotation can be measured directly in a transmission electron microscope, and discuss its relation to the well known classical image rotation associated with the Lorentz force.

  2. Faraday rotation and photoluminescence in heavily Tb3+-doped GeO2-B2O3-Al2O3-Ga2O3 glasses for fiber-integrated magneto-optics

    Science.gov (United States)

    Gao, Guojun; Winterstein-Beckmann, Anja; Surzhenko, Oleksii; Dubs, Carsten; Dellith, Jan; Schmidt, Markus A.; Wondraczek, Lothar

    2015-01-01

    We report on the magneto-optical (MO) properties of heavily Tb3+-doped GeO2-B2O3-Al2O3-Ga2O3 glasses towards fiber-integrated paramagnetic MO devices. For a Tb3+ ion concentration of up to 9.7 × 1021 cm−3, the reported glass exhibits an absolute negative Faraday rotation of ~120 rad/T/m at 632.8 nm. The optimum spectral ratio between Verdet constant and light transmittance over the spectral window of 400–1500 nm is found for a Tb3+ concentration of ~6.5 × 1021 cm−3. For this glass, the crystallization stability, expressed as the difference between glass transition temperature and onset temperature of melt crystallization exceeds 100 K, which is a prerequisite for fiber drawing. In addition, a high activation energy of crystallization is achieved at this composition. Optical absorption occurs in the NUV and blue spectral region, accompanied by Tb3+ photoluminescence. In the heavily doped materials, a UV/blue-to-green photo-conversion gain of ~43% is achieved. The lifetime of photoluminescence is ~2.2 ms at a stimulated emission cross-section σem of ~1.1 × 10−21 cm2 for ~ 5.0 × 1021 cm−3 Tb3+. This results in an optical gain parameter σem*τ of ~2.5 × 10−24 cm2s, what could be of interest for implementation of a Tb3+ fiber laser. PMID:25754819

  3. Faraday rotation and photoluminescence in heavily Tb(3+)-doped GeO2-B2O3-Al2O3-Ga2O3 glasses for fiber-integrated magneto-optics.

    Science.gov (United States)

    Gao, Guojun; Winterstein-Beckmann, Anja; Surzhenko, Oleksii; Dubs, Carsten; Dellith, Jan; Schmidt, Markus A; Wondraczek, Lothar

    2015-03-10

    We report on the magneto-optical (MO) properties of heavily Tb(3+)-doped GeO2-B2O3-Al2O3-Ga2O3 glasses towards fiber-integrated paramagnetic MO devices. For a Tb(3+) ion concentration of up to 9.7 × 10(21) cm(-3), the reported glass exhibits an absolute negative Faraday rotation of ~120 rad/T/m at 632.8 nm. The optimum spectral ratio between Verdet constant and light transmittance over the spectral window of 400-1500 nm is found for a Tb(3+) concentration of ~6.5 × 10(21) cm(-3). For this glass, the crystallization stability, expressed as the difference between glass transition temperature and onset temperature of melt crystallization exceeds 100 K, which is a prerequisite for fiber drawing. In addition, a high activation energy of crystallization is achieved at this composition. Optical absorption occurs in the NUV and blue spectral region, accompanied by Tb(3+) photoluminescence. In the heavily doped materials, a UV/blue-to-green photo-conversion gain of ~43% is achieved. The lifetime of photoluminescence is ~2.2 ms at a stimulated emission cross-section σem of ~1.1 × 10(-21) cm(2) for ~ 5.0 × 10(21) cm(-3) Tb(3+). This results in an optical gain parameter σem*τ of ~2.5 × 10(-24) cm(2)s, what could be of interest for implementation of a Tb(3+) fiber laser.

  4. A Mobile Phone Faraday Cage

    Science.gov (United States)

    French, M. M. J.

    2011-01-01

    A Faraday cage is an interesting physical phenomenon where an electromagnetic wave can be excluded from a volume of space by enclosure with an electrically conducting material. The practical application of this in the classroom is to block the signal to a mobile phone by enclosing it in a metal can. The background of the physics behind this is…

  5. Streaming patterns in Faraday waves

    CERN Document Server

    Périnet, Nicolas; Urra, Héctor; Mujica, Nicolás; Gordillo, Leonardo

    2016-01-01

    Waves patterns in the Faraday instability have been studied for decades. Besides the rich dynamics that can be observed on the waves at the interface, Faraday waves hide beneath them an elusive range of flow patterns --or streaming patterns-- which have not been studied in detail until now. The streaming patterns are responsible for a net circulation in the flow which are reminiscent of convection cells. In this article, we analyse these streaming flows by conducting experiments in a Faraday-wave setup. To visualize the flows, tracers are used to generate both trajectory maps and to probe the streaming velocity field via Particle Image Velocimetry (PIV). We identify three types of patterns and experimentally show that identical Faraday waves can mask streaming patterns that are qualitatively very different. Next we propose a three-dimensional model that explains streaming flows in quasi-inviscid fluids. We show that the streaming inside the fluid arises from a complex coupling between the bulk and the boundar...

  6. THE EXPERIMENT WITH FARADAY CYLINDER

    Institute of Scientific and Technical Information of China (English)

    薛英

    2004-01-01

    Suppose there are two electricity testers, A and B(Figure A) . And a metal cylinder C which is almost closed (called Faraday Cylinder)is fixed to tester B, making both tester B and cylinder C charged. As a result, the aluminium foil on tester B opens.

  7. Various Paths to Faraday's Law

    Science.gov (United States)

    Redzic, Dragan V.

    2008-01-01

    In a recent note, the author presented a derivation of Faraday's law of electromagnetic induction for a closed filamentary circuit C(t) which is moving at relativistic velocities and also changing its shape as it moves via the magnetic vector potential. Recently, Kholmetskii et al, while correcting an error in an equation, showed that it can be…

  8. A Mobile Phone Faraday Cage

    Science.gov (United States)

    French, M. M. J.

    2011-01-01

    A Faraday cage is an interesting physical phenomenon where an electromagnetic wave can be excluded from a volume of space by enclosure with an electrically conducting material. The practical application of this in the classroom is to block the signal to a mobile phone by enclosing it in a metal can. The background of the physics behind this is…

  9. Faraday's Law and Seawater Motion

    Science.gov (United States)

    De Luca, R.

    2010-01-01

    Using Faraday's law, one can illustrate how an electromotive force generator, directly utilizing seawater motion, works. The conceptual device proposed is rather simple in its components and can be built in any high school or college laboratory. The description of the way in which the device generates an electromotive force can be instructive not…

  10. Faraday Cage Protects Against Lightning

    Science.gov (United States)

    Jafferis, W.; Hasbrouck, R. T.; Johnson, J. P.

    1992-01-01

    Faraday cage protects electronic and electronically actuated equipment from lightning. Follows standard lightning-protection principles. Whether lightning strikes cage or cables running to equipment, current canceled or minimized in equipment and discharged into ground. Applicable to protection of scientific instruments, computers, radio transmitters and receivers, and power-switching equipment.

  11. Faraday rotation enhancement of gold coated Fe2O3 nanoparticles: comparison of experiment and theory.

    Science.gov (United States)

    Dani, Raj Kumar; Wang, Hongwang; Bossmann, Stefan H; Wysin, Gary; Chikan, Viktor

    2011-12-14

    Understanding plasmonic enhancement of nanoscale magnetic materials is important to evaluate their potential for application. In this study, the Faraday rotation (FR) enhancement of gold coated Fe(2)O(3) nanoparticles (NP) is investigated experimentally and theoretically. The experiment shows that the Faraday rotation of a Fe(2)O(3) NP solution changes from approximately 3 rad/Tm to 10 rad/Tm as 5 nm gold shell is coated on a 9.7 nm Fe(2)O(3) core at 632 nm. The results also show how the volume fraction normalized Faraday rotation varies with the gold shell thickness. From the comparison of experiment and calculated Faraday rotation based on the Maxwell-Garnett theory, it is concluded that the enhancement and shell dependence of Faraday rotation of Fe(2)O(3) NPs is a result of the shifting plasmon resonance of the composite NP. In addition, the clustering of the NPs induces a different phase lag on the Faraday signal, which suggests that the collective response of the magnetic NP aggregates needs to be considered even in solution. From the Faraday phase lag, the estimated time of the full alignment of the magnetic spins of bare (cluster size 160 nm) and gold coated NPs (cluster size 90 nm) are found to be 0.65 and 0.17 μs. The calculation includes a simple theoretical approach based on the Bruggeman theory to account for the aggregation and its effect on the Faraday rotation. The Bruggeman model provides a qualitatively better agreement with the experimentally observed Faraday rotation and points out the importance of making a connection between component properties and the average "effective" optical behavior of the Faraday medium containing magnetic nanoparticles.

  12. Brazil World Cup Challenges

    Directory of Open Access Journals (Sweden)

    MANSUR, R.

    2012-12-01

    Full Text Available Overcoming the productivity challenge is the main benefit of the 2014 World Cup for Brazilian people. The sustainable development of our cultural tourism industry will catapult the new middle class growing up rate.

  13. Brazil World Cup Challenges

    OpenAIRE

    MANSUR, R.

    2012-01-01

    Overcoming the productivity challenge is the main benefit of the 2014 World Cup for Brazilian people. The sustainable development of our cultural tourism industry will catapult the new middle class growing up rate.

  14. TSAG-based cryogenic Faraday isolator

    Science.gov (United States)

    Starobor, Aleksey; Yasyhara, Ryo; Snetkov, Ilya; Mironov, Evgeniy; Palashov, Oleg

    2015-09-01

    Thermooptical and magnetooptical properties of novel magnetoactive crystal terbium-scandium aluminum garnet were investigated at temperature range 80-300 K. It is shown that Verdet constant increases inversely proportional to temperature, and thermally induced depolarization, and the optical power of the thermal lens is reduced significantly with cooling from 290 K to 80 K. According to estimates, TSAG crystals in [1 1 1] orientation allow to create a cryogenic Faraday isolator provides a degree of isolation of 30 dB with the laser power exceeds ∼6 kW, it is estimated that the transition to the [0 0 1] orientation allows to provide degree of isolation of 30 dB at a laser power higher than 400 kW.

  15. A Faraday effect position sensor for interventional magnetic resonance imaging.

    Science.gov (United States)

    Bock, M; Umathum, R; Sikora, J; Brenner, S; Aguor, E N; Semmler, W

    2006-02-21

    An optical sensor is presented which determines the position and one degree of orientation within a magnetic resonance tomograph. The sensor utilizes the Faraday effect to measure the local magnetic field, which is modulated by switching additional linear magnetic fields, the gradients. Existing methods for instrument localization during an interventional MR procedure often use electrically conducting structures at the instruments that can heat up excessively during MRI and are thus a significant danger for the patient. The proposed optical Faraday effect position sensor consists of non-magnetic and electrically non-conducting components only so that heating is avoided and the sensor could be applied safely even within the human body. With a non-magnetic prototype set-up, experiments were performed to demonstrate the possibility of measuring both the localization and the orientation in a magnetic resonance tomograph. In a 30 mT m(-1) gradient field, a localization uncertainty of 1.5 cm could be achieved.

  16. Gravitational Faraday Rotation of the Earth and Its Possible Test

    Institute of Scientific and Technical Information of China (English)

    LIU Lin-Xia; SHAO Cheng-Gang; LUO Jun

    2005-01-01

    @@ It is shown that the rotation of the polarization plane of rays induced by a rotating body can be accumulated by means of a long baseline optical cavity. Theoretical analysis shows that the presently proposal experimental scheme is possible to test this gravitational Faraday rotation effect on the Earth, especially including how to effectively suppress the dominant part of the Sagnac effect due to the rotation of the Earth with a reasonable experimental configuration.

  17. A mobile phone Faraday cage

    Science.gov (United States)

    French, M. M. J.

    2011-05-01

    A Faraday cage is an interesting physical phenomenon where an electromagnetic wave can be excluded from a volume of space by enclosure with an electrically conducting material. The practical application of this in the classroom is to block the signal to a mobile phone by enclosing it in a metal can. The background of the physics behind this is described in some detail, and this is followed by a explanation of some demonstrations and experiments which I have used.

  18. Faraday rotation in CMB maps

    Science.gov (United States)

    Ruiz-Granados, Beatriz; Battaner, Eduardo; Florido, Estrella

    2016-10-01

    WMAP CMB polarization maps have been used to detect a low signal of Faraday Rotation (FR). If this detection is not interpreted as simple noise, it could be produced: at the last scattering surface (LSS) (z=1100), being primordial, at Reionization (z=10), in the Milky Way. The second interpretation is favoured here. In this case magnetic fields at Reionization with peak values of the order of 10-8 G should produce this observational FR.

  19. Prevalence of disc cupping in non-glaucomatous eyes

    Directory of Open Access Journals (Sweden)

    José Pablo Chiappe

    2015-02-01

    Full Text Available This study assessed optic disc size and cupping, using a commercially available ophthalmoscope, in order to show norms of these values for clinical practice. Subjects were office-workers referred from their respective workplaces for a routine medical examination, which included eye examination. The optic disc size was classified as small, medium or large, for having a diameter 1.5 times (respectively the diameter of the ophthalmoscope's selected light spot on the posterior pole. The cupping was classified as the ratio of the vertical cupping diameter and the vertical disc diameter on a relative decimal scale from 0.0 to 1.0.This study included 184 subjects with a mean age of 40.5 ± 9.5 years; 149 (81% were males. Their mean ocular pressure was 12.4 ± 1.5 mmHg (range 10-17 mmHg. There was a high correlation between optic disc sizes and cupping in the right and left eyes (Pearson Correlation r = 0.866, p < 0.001; therefore, for simplicity only the data for right eyes are presented. According to our definition, the optic discs in these eyes comprised 27 (14.7% small, 141 (76.6% medium and 16 (8.7% large. The small optic discs were rarely cupped, and the large optic discs were always cupped. Optic disc cupping greater than 0.7 was rarely found and should be suspect of glaucoma. Clinical doctors should be aware of this and refer those subjects with abnormal cupping to the specialist.

  20. Theoretical model for frequency locking a diode laser with a Faraday cell

    Science.gov (United States)

    Wanninger, P.; Shay, T. M.

    1992-01-01

    A new method was developed for frequency locking a diode lasers, called 'the Faraday anomalous dispersion optical transmitter (FADOT) laser locking', which is much simpler than other known locking schemes. The FADOT laser locking method uses commercial laser diodes with no antireflection coatings, an atomic Faraday cell with a single polarizer, and an output coupler to form a compound cavity. The FADOT method is vibration insensitive and exhibits minimal thermal expansion effects. The system has a frequency pull in the range of 443.2 GHz (9 A). The method has potential applications in optical communication, remote sensing, and pumping laser excited optical filters.

  1. Complementary Coffee Cups

    Science.gov (United States)

    Banchoff, Thomas

    2006-01-01

    What may have been the birth of a new calculus problem took place when the author noticed that two coffee cups, one convex and one concave, fit nicely together, and he wondered which held more coffee. The fact that their volumes were about equal led to the topic of this article: complementary surfaces of revolution with equal volumes.

  2. Compact rotating cup anemometer

    Science.gov (United States)

    Wellman, J. B.

    1968-01-01

    Compact, collapsible rotating cup anemometer is used in remote locations where portability and durability are factors in the choice of equipment. This lightweight instrument has a low wind-velocity threshold, is capable of withstanding large mechanical shocks while in its stowed configuration, and has fast response to wind fluctuations.

  3. The perennial cup anemometer

    Science.gov (United States)

    Kristensen, L.

    1999-01-01

    A short version of the history of the cup anemometer precedes a more technical discussion of the special features of this instrument. These include its extremely linear calibration and the non-linearity of its response to wind speed changes. A simple conceptual model by Schrenk is used to demonstrate this and to explain why the cup anemometer is able to start from a zero rotation rate at zero wind to one corresponding to a sudden change in the ambient wind speed to a finite value. The same model is used to show that the cup anemometer should be characterized by a distance constant rather than by a time constant. The bias in the measured mean wind speed due to the random variations in the three velocity components is discussed in terms of standard, semiquantitative turbulence models, and the main thesis is that this bias is overwhelmingly dominated by the fluctuations of the lateral wind velocity component, i.e. the wind component perpendicular to the mean wind direction, and not, as is often assumed, by the longitudinal wind velocity component. It is shown theoretically and tested experimentally that the bias due to lateral wind velocity fluctuations can be significantly reduced by means of a special data processing of the simultaneous signals from a cup anemometer and a wind vane. This means that, with care, the overall overspeeding can be reduced to less than 1%.

  4. Effects of interband transitions on Faraday rotation in metallic nanoparticles.

    Science.gov (United States)

    Wysin, G M; Chikan, Viktor; Young, Nathan; Dani, Raj Kumar

    2013-08-14

    The Faraday rotation in metallic nanoparticles is considered based on a quantum model for the dielectric function ϵ(ω) in the presence of a DC magnetic field B. We focus on effects in ϵ(ω) due to interband transitions (IBTs), which are important in the blue and ultraviolet for noble metals used in plasmonics. The dielectric function is found using the perturbation of the electron density matrix due to the optical field of the incident electromagnetic radiation. The calculation is applied to transitions between two bands (d and p, for example) separated by a gap, as one finds in gold at the L-point of the Fermi surface. The result of the DC magnetic field is a shift in the effective optical frequency causing IBTs by ±μBB/ħ, where opposite signs are associated with left/right circular polarizations. The Faraday rotation for a dilute solution of 17 nm diameter gold nanoparticles is measured and compared with both the IBT theory and a simpler Drude model for the bound electron response. Effects of the plasmon resonance mode on Faraday rotation in nanoparticles are also discussed.

  5. A Note on Faraday Paradoxes

    CERN Document Server

    Auchmann, Bernhard; Russenschuck, Stephan

    2014-01-01

    The validity of the flux rule to determine the electromotive force in a cycle, epsilon = -d Phi/dt, has been the subject of a large amount of controversy since the beginning of electrical technology. Although most authors reach correct conclusions for a class of problems called Faraday paradoxes, the arguments that are used vary and often rely on ad-hoc physical reasoning. A didactic and insightful treatment should be based solely on Maxwell's equations, the constitutive laws, and a detailed study of the mathematics involved.

  6. Faraday Rotator Glass for Laser Application

    Institute of Scientific and Technical Information of China (English)

    JIANG Ya-si; ZHOU Bei-ming; WANG Biao; HU Li-li

    2007-01-01

    Glasses with strong Faraday rotation are interest for laser applications. The principles of diamagnetic and paramagnetic Faraday rotator glasses are described theoretically and experimentally. High performance Tb-paramagnetic glass series were developed and produced at Kigre in the US and SIOM in Shanghai. Large aperture glass disks have been used for high power laser fusion systems.

  7. Determination of Faraday rotation in a ferrofluid

    Science.gov (United States)

    Yusuf, Nihad A.; Rousan, Akram A.; El-Ghanem, Hassan M.

    1987-03-01

    Transmission of plane polarised light through ferrofluids in the presence of a magnetic field parallel to the direction of propagation depends on both chain formation and Faraday rotation. A procedure is proposed to separate between both factors. Faraday rotation in a dilute Fe 3O 4 ferrofluid measured by this procedure does not show saturation in fields up to 4000 G.

  8. Intrinsic polarization angle ambiguity in Faraday tomography

    CERN Document Server

    Kumazaki, Kohei; Ideguchi, Shinsuke; Kurayama, Tomoharu; Takahashi, Keitaro

    2014-01-01

    Faraday tomography is a powerful method to diagnose polarizations and Faraday rotations along the line of sight. Quality of Faraday tomography is, however, limited by several conditions. Recently, it is reported that Faraday tomography indicates false signals in some specific situations. In this paper, we systematically investigate the condition of the appearance of false signals in Faraday tomography. We study the situations that we observe two sources within a beam, and change the intrinsic polarization angles, rotation measures, intensities, and frequency coverage. We find that false signals arise when rotation measure between the sources is less than 1.5 times the full width at half maximum of the rotation measure spread function. False signals also depend on the intensity ratio between the sources and are reduced for large ratio. On the other hand, the appearance of false signals does not depend on frequency coverage, meaning that the uncertainty should be correctly understood and taken into consideratio...

  9. A desktop Faraday rotation instrument in the ultraviolet

    Science.gov (United States)

    Ström, Valter; Rao, K. V.

    2008-02-01

    A simple versatile desktop instrument for the measurement of Faraday rotation in the ultraviolet range has been designed and constructed. A high pressure short arc mercury lamp is used for the light source. By using interference filter for mercury, the desired wavelength of the available lines for mercury (e.g., 365, 405, and 436 nm) is selected. Our instrument measures hysteresis loops in magnetic fields up to 900 kA/m within a few minutes. With a light beam intensity monitor, the detrimental effect from fluctuations in the light source has been virtually eliminated. The instrument can operate at photocurrents from the picoampere regime and above with a Faraday rotation sensitivity of around 1 millideg. By incorporating a higher order Taylor expansion approach, we improve the linearity of the Faraday rotation to transmitted light relationship by two orders of magnitude. The electronics is custom designed analog type, rendering relaxed dynamic requirements for the analog-to-digital converter. The design is fully protected from ambient light which makes operation with the equipment in darkness superfluous; neither does it need any optical table. The data acquisition and operation of the instrument are fully supported by a LABVIEW program. Measurements on a magnetite thin film and on microscope cover glass are given as examples for the performance and sensitivity of the equipment.

  10. Giant Faraday rotation of high-order plasmonic modes in graphene-covered nanowires

    CERN Document Server

    Kuzmin, Dmitry A; Shavrov, Vladimir G; Temnov, Vasily V

    2016-01-01

    Plasmonic Faraday rotation in nanowires manifests itself in the rotation of the spatial intensity distribution of high-order surface plasmon polariton (SPP) modes around the nanowire axis. Here we predict theoretically the giant Faraday rotation for SPP propagating on graphene-coated magneto-optically active nanowires. Upon the reversal of the external magnetic field pointing along the nanowire axis some high-order plasmonic modes may be rotated by up to ~ 100 degrees on scale of about 500 nm at mid-infrared frequencies. Tuning carrier concentration in graphene by chemical doping or gate voltage allows for controlling SPP-properties and notably the rotation angle of high-order azimuthal modes. Our results open the door to novel plasmonic applications ranging from nanowire-based Faraday isolators to the magnetic control in quantum-optical applications.

  11. Approach to high-frequency, cavity-enhanced Faraday rotation in fluids.

    Science.gov (United States)

    Pagliero, D; Li, Y; Fisher, S; Meriles, C A

    2011-02-10

    Recent work demonstrating detection of nuclear spin magnetization via Faraday rotation in transparent fluids promises novel opportunities for magnetic resonance imaging and spectroscopy. Unfortunately, low sensitivity is a serious concern. With this motivation in mind, we explore the use of an optical cavity to augment the Faraday rotation experienced by a linearly polarized beam traversing a sample fluid. Relying on a setup that affords reduced sample size and high-frequency modulation, we demonstrate amplification of regular (i.e., nonnuclear) Faraday rotation of order 20. Extensions of the present methodology that take into account the geometric constraints imposed by a high-field magnet may open the way to high-sensitivity, optically-detected magnetic resonance in the liquid state.

  12. Giant Faraday Rotation of High-Order Plasmonic Modes in Graphene-Covered Nanowires.

    Science.gov (United States)

    Kuzmin, Dmitry A; Bychkov, Igor V; Shavrov, Vladimir G; Temnov, Vasily V

    2016-07-13

    Plasmonic Faraday rotation in nanowires manifests itself in the rotation of the spatial intensity distribution of high-order surface plasmon polariton (SPP) modes around the nanowire axis. Here we predict theoretically the giant Faraday rotation for SPPs propagating on graphene-coated magneto-optically active nanowires. Upon the reversal of the external magnetic field pointing along the nanowire axis some high-order plasmonic modes may be rotated by up to ∼100° on the length scale of about 500 nm at mid-infrared frequencies. Tuning the carrier concentration in graphene by chemical doping or gate voltage allows for controlling SPP-properties and notably the rotation angle of high-order azimuthal modes. Our results open the door to novel plasmonic applications ranging from nanowire-based Faraday isolators to the magnetic control in quantum-optical applications.

  13. Peculiarities of the inverse Faraday effect induced in iron garnet films by femtosecond laser pulses

    Science.gov (United States)

    Kozhaev, M. A.; Chernov, A. I.; Savochkin, I. V.; Kuz'michev, A. N.; Zvezdin, A. K.; Belotelov, V. I.

    2016-12-01

    The inverse Faraday effect in iron garnet films subjected to femtosecond laser pulses is experimentally investigated. It is found that the magnitude of the observed effect depends nonlinearly on the energy of the optical pump pulses, which is in contradiction with the notion that the inverse Faraday effect is linear with respect to the pump energy. Thus, for pump pulses with a central wavelength of 650 nm and an energy density of 1 mJ/cm2, the deviation from a linear dependence is as large as 50%. Analysis of the experimental data demonstrates that the observed behavior is explained by the fact that the optically induced normal component of the magnetization is determined, apart from the field resulting from the inverse Faraday effect, by a decrease in the magnitude of the precessing magnetization under the influence of the femtosecond electromagnetic field.

  14. Faraday wave lattice as an elastic metamaterial.

    Science.gov (United States)

    Domino, L; Tarpin, M; Patinet, S; Eddi, A

    2016-05-01

    Metamaterials enable the emergence of novel physical properties due to the existence of an underlying subwavelength structure. Here, we use the Faraday instability to shape the fluid-air interface with a regular pattern. This pattern undergoes an oscillating secondary instability and exhibits spontaneous vibrations that are analogous to transverse elastic waves. By locally forcing these waves, we fully characterize their dispersion relation and show that a Faraday pattern presents an effective shear elasticity. We propose a physical mechanism combining surface tension with the Faraday structured interface that quantitatively predicts the elastic wave phase speed, revealing that the liquid interface behaves as an elastic metamaterial.

  15. Faraday wave lattice as an elastic metamaterial

    CERN Document Server

    Domino, L; Patinet, Sylvain; Eddi, A

    2016-01-01

    Metamaterials enable the emergence of novel physical properties due to the existence of an underlying sub-wavelength structure. Here, we use the Faraday instability to shape the fluid-air interface with a regular pattern. This pattern undergoes an oscillating secondary instability and exhibits spontaneous vibrations that are analogous to transverse elastic waves. By locally forcing these waves, we fully characterize their dispersion relation and show that a Faraday pattern presents an effective shear elasticity. We propose a physical mechanism combining surface tension with the Faraday structured interface that quantitatively predicts the elastic wave phase speed, revealing that the liquid interface behaves as an elastic metamaterial.

  16. Faraday rotation system. Topical report

    Energy Technology Data Exchange (ETDEWEB)

    Bauman, L.E.; Wang, W.

    1994-07-01

    The Faraday Rotation System (FRS) is one of the advanced laser-based diagnostics developed at DIAL to provide support for the demonstration of prototype-scale coal-fired combustion magnetohydrodynamic (MHD) electrical power generation. Intended for application in the MHD channel, the system directly measures electron density through a measurement of the induced rotation in the polarization of a far infrared laser beam after passing through the MHD flow along the magnetic field lines. A measurement of the induced polarization ellipticity provides a measure of the electron collision frequency which together with the electron density gives the electron conductivity, a crucial parameter for MHD channel performance. The theory of the measurements, a description of the system, its capabilities, laboratory demonstration measurements on seeded flames with comparison to emission absorption measurements, and the current status of the system are presented in this final report.

  17. Faraday laser using 1.2 km fiber as an extended cavity

    Science.gov (United States)

    Tao, Zhiming; Zhang, Xiaogang; Pan, Duo; Chen, Mo; Zhu, Chuanwen; Chen, Jingbiao

    2016-07-01

    We demonstrate a Faraday laser using a 1.2 km fiber as an extended cavity, which provides optical feedback and obtains small free spectrum range (FSR) of 83 kHz, and have succeeded in limiting the laser frequency to a crossover transition {5}2{S}1/2,F=2\\to {5}2{P}3/2,F\\prime =1,3 of the natural 87Rb at 780 nm. The Faraday laser is based on a Faraday anomalous dispersion optical filter (FADOF) with an ultra-narrow bandwidth and the long fiber extended cavity of 1.2 km. The peak transmission assigned to the crossover transition F=2\\to F\\prime =1,3 in the FADOF is 20.5% with an ultra-narrow bandwidth of 29.1 MHz. The Allan deviation of the Faraday laser is around 6.0× {10}-11 in 0.06 to 1 s sampling time. Laser frequency is always kept in the center of the transmitted peak assigned to F=2\\to F\\prime =1,3. The Faraday laser realized here can provide light exactly resonant with an atomic transition used for atom-photon interaction experiments and is insensitive to diode temperature and injection current fluctuations.

  18. A Faraday laser lasing on Rb 1529 nm transition.

    Science.gov (United States)

    Chang, Pengyuan; Peng, Huanfa; Zhang, Shengnan; Chen, Zhangyuan; Luo, Bin; Chen, Jingbiao; Guo, Hong

    2017-08-21

    We present the design and performance characterization of a Faraday laser directly lasing on the Rb 1529 nm transition (Rb, 5P 3/2 - 4D 5/2) with high stability, narrow spectral linewidth and low cost. This system does not need an additional frequency-stabilized pump laser as a prerequisite to preparing Rb atom from 5S to 5P excited state. Just by using a performance-improved electrodeless discharge lamp-based excited-state Faraday anomalous dispersion optical filter (LESFADOF), we realized a heterogeneously Faraday laser with the frequency corresponding to atomic transition, working stably over a range of laser diode (LD) current from 85 mA to 171 mA and the LD temperature from 11 °C to 32 °C, as well as the 24-hour long-term frequency fluctuation range of no more than 600 MHz. Both the laser linewidth and relative intensity noisy (RIN) are measured. The Faraday laser lasing on Rb 1529 nm transition (telecom C-band) can be applied to further research on metrology, microwave photonics and optical communication systems. Besides, since the transitions correspongding to the populated excited-states of alkali atoms within lamp are extraordinarily rich, this scheme can increase the flexibility for choosing proper wavelengths for Faraday laser and greatly expand the coverage of wavelength corresponding to atomic transmission for laser frequency stabilization.

  19. Field calibration of cup anemometers

    DEFF Research Database (Denmark)

    Schmidt Paulsen, Uwe; Mortensen, Niels Gylling; Hansen, Jens Carsten

    2007-01-01

    A field calibration method and results are described along with the experience gained with the method. The cup anemometers to be calibrated are mounted in a row on a 10-m high rig and calibrated in the free wind against a reference cup anemometer. The method has been reported [1] to improve...... the statistical bias on the data relative to calibrations carried out in a wind tunnel. The methodology is sufficiently accurate for calibration of cup anemometers used for wind resource assessments and provides a simple, reliable and cost-effective solution to cup anemometer calibration, especially suited...

  20. World Cup television

    OpenAIRE

    2012-01-01

    In the last year of the first decade of the 21st century, in the verge of breaking into the era of digital television, it is important to know what kind of television model is available in Portugal. The analysis of the news coverage of the FIFA 2010 World Cup will certainly help in finding the answers. In this article, we present a study that centers its focus on news formats related to this great media event, broadcasted in both generalist as well as cable news networks between the 11th of J...

  1. Double Cups with Phoenix

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    THIS cup, unearthed at the site of an aristocrat’s tomb (No. 2 Baoshan Tomb) of the Chu State, was a vessel used during weddings in ancient times. According to the earliest account of the vessel, found in the book Liji, a new couple would use it to gargle together, which meant that they would be of one heart and one mind, and that they would love and take care of each other. Shaped like a standing phoenix, the vessel is 17.6 cm. long. The phoenix holds a pearl in its beak and its wings are spread

  2. Magnetic field tomography and differential Faraday rotation

    CERN Document Server

    Horellou, Cathy

    2014-01-01

    Wide-band radio polarization observations offer the possibility to recover information about the magnetic fields in synchrotron sources, such as details of their three dimensional configuration, that has previously been inaccessible. The key physical process involved is the Faraday rotation of the polarized emission in the source (and elsewhere along its propagation path). In order to proceed reliable methods are required for inverting the signals observed in wavelength space into useful data in Faraday space, with robust estimates of their uncertainty. In this paper we examine how variations of the intrinsic angle of polarized emission chi0 with the Faraday depth phi within a source affect the observable quantities. Using simple models for the Faraday dispersion F(phi) and chi0(phi), along with the current and planned properties of the main radio interferometers, we demonstrate how degeneracies among the parameters describing the magneto-ionic medium can be minimised by combining observations in different wa...

  3. Giant photoinduced Faraday rotation due to the spin-polarized electron gas in an n-GaAs microcavity

    Science.gov (United States)

    Giri, R.; Cronenberger, S.; Vladimirova, M.; Scalbert, D.; Kavokin, K. V.; Glazov, M. M.; Nawrocki, M.; Lemaître, A.; Bloch, J.

    2012-05-01

    Faraday rotation up to 19∘ in the absence of an external magnetic field is demonstrated in an n-type bulk GaAs microcavity under circularly polarized optical excitation. This strong effect is achieved because (i) the spin-polarized electron gas is an efficient Faraday rotator and (ii) the light wave makes multiple round trips in the cavity. We introduce a concept of Faraday rotation cross section as a proportionality coefficient between the rotation angle, electron spin density and optical path and calculate this cross section for our system. From independent measurements of photoinduced Faraday rotation and electron spin polarization we obtain quantitatively the cross section of the Faraday rotation induced by free electron spin polarization σFexp=-(2.5±0.6)×10-15 rad×cm2 for photon energy 18 meV below the band gap of GaAs, and electron concentration 2×1016 cm-3. It appears to exceed the theoretical value σFth=-0.7×10-15 rad×cm2, calculated without fitting parameters. We also demonstrate the proof-of-principle of a fast optically controlled Faraday rotator.

  4. The hyperfine Paschen-Back Faraday effect

    OpenAIRE

    Zentile, Mark A.; Andrews, Rebecca; Weller, Lee; Knappe, Svenja; Adams, Charles S.; Hughes, Ifan G

    2014-01-01

    We investigate experimentally and theoretically the Faraday effect in an atomic medium in the hyperfine Paschen-Back regime, where the Zeeman interaction is larger than the hyperfine splitting. We use a small permanent magnet and a micro-fabricated vapour cell, giving magnetic fields of the order of a Tesla. We show that for low absorption and small rotation angles, the refractive index is well approximated by the Faraday rotation signal, giving a simple way to measure the atomic refractive i...

  5. The Correspondence of Michael Faraday Pt 6 1860-1867

    CERN Document Server

    Frank, James

    2012-01-01

    Michael Faraday (1791-1867) was one of the most important men of science in nineteenth century Britain. His discoveries of electro-magnetic rotations (1821) and electro-magnetic induction (1831) laid the foundations of the modern electrical industry. His discovery of the magneto-optical effect and diamagnetism (1845) led him to formulate the field theory of electro-magnetism, which forms one of the cornerstones of modern physics.These and a whole host of other fundamental discoveries in physics and chemistry, together with his lecturing at the Royal Institution, his work for the state (includi

  6. Multispectral Kerr frequency comb initiated by Faraday ripples

    CERN Document Server

    Huang, Shu-Wei

    2016-01-01

    In a uniform microresonator, the generation of a broadband Kerr frequency comb is triggered by Turing patterns. Here, we study a distinctly different route to initiate the Kerr frequency comb by Faraday ripples. Momentum conservation is ensured by azimuthal modulation of the cavity dispersion. With a good agreement with the theoretical analysis, we demonstrate a multispectral Kerr frequency comb covering telecommunication O, C, L, and 2 {\\mu}m bands. Comb coherence and absence of a subcomb offset are confirmed by cw heterodyne beat note and amplitude noise spectra measurements. The device can be used for achieving broadband optical frequency synthesizer and high-capacity coherent telecommunication.

  7. Faraday rotation in bilayer graphene-based integrated microcavity.

    Science.gov (United States)

    Da, Hai-Xia; Yan, Xiao-Hong

    2016-01-01

    Bernal-stacked bilayer graphene has rich ground states with various broken symmetries, allowing the existence of magneto-optical (MO) effects even in the absence of an external magnetic field. Here we report controllable Faraday rotation (FR) of bilayer graphene induced by electrostatic gate voltage, whose value is 10 times smaller than the case of single layer graphene with a magnetic field. A proposed bilayer graphene-based microcavity configuration enables the enhanced FR angle due to the large localized electromagnetic field. Our results offer unique opportunities to apply bilayer graphene for MO devices.

  8. Faraday rotator based on TSAG crystal with orientation.

    Science.gov (United States)

    Yasuhara, Ryo; Snetkov, Ilya; Starobor, Aleksey; Mironov, Evgeniy; Palashov, Oleg

    2016-07-11

    A Faraday isolator (FI) for high-power lasers with kilowatt-level average power and 1-µm wavelength was demonstrated using a terbium scandium aluminum garnet (TSAG) with its crystal axis aligned in the direction. Furthermore, no compensation scheme for thermally induced depolarization in a magnetic field was used. An isolation ratio of 35.4 dB (depolarization ratio γ of 2.9 × 10-4) was experimentally observed at a maximum laser power of 1470 W. This result for room-temperature FIs is the best reported, and provides a simple, practical solution for achieving optical isolation in high-power laser systems.

  9. Cup Cylindrical Waveguide Antenna

    Science.gov (United States)

    Acosta, Roberto J.; Darby, William G.; Kory, Carol L.; Lambert, Kevin M.; Breen, Daniel P.

    2008-01-01

    The cup cylindrical waveguide antenna (CCWA) is a short backfire microwave antenna capable of simultaneously supporting the transmission or reception of two distinct signals having opposite circular polarizations. Short backfire antennas are widely used in mobile/satellite communications, tracking, telemetry, and wireless local area networks because of their compactness and excellent radiation characteristics. A typical prior short backfire antenna contains a half-wavelength dipole excitation element for linear polarization or crossed half-wavelength dipole elements for circular polarization. In order to achieve simultaneous dual circular polarization, it would be necessary to integrate, into the antenna feed structure, a network of hybrid components, which would introduce significant losses. The CCWA embodies an alternate approach that entails relatively low losses and affords the additional advantage of compactness. The CCWA includes a circular cylindrical cup, a circular disk subreflector, and a circular waveguide that serves as the excitation element. The components that make it possible to obtain simultaneous dual circular polarization are integrated into the circular waveguide. These components are a sixpost polarizer and an orthomode transducer (OMT) with two orthogonal coaxial ports. The overall length of the OMT and polarizer (for the nominal middle design frequency of 2.25 GHz) is about 11 in. (approximately equal to 28 cm), whereas the length of a commercially available OMT and polarizer for the same frequency is about 32 in. (approximately equal to 81 cm).

  10. Alternative medicine: an update on cupping therapy.

    Science.gov (United States)

    Chen, B; Li, M-Y; Liu, P-D; Guo, Y; Chen, Z-L

    2015-07-01

    To know the research progress of cupping therapy all over the world, the authors analyze the research of cupping therapy in recent 5 years. It indicates that cupping therapy can be applied to extensive curable disease, but has poor clinical evidence. Some improvements in the mechanism research of cupping therapy have been made, but it needs further research. The adverse events of cupping therapy attract attention. The standardization of cupping therapy has emerged.

  11. Far off-resonance laser frequency stabilization using multipass cells in Faraday rotation spectroscopy.

    Science.gov (United States)

    Quan, Wei; Li, Yang; Li, Rujie; Shang, Huining; Fang, Zishan; Qin, Jie; Wan, Shuangai

    2016-04-01

    We propose a far off-resonance laser frequency stabilization method by using multipass cells in Rb Faraday rotation spectroscopy. Based on the detuning equation, if multipass cells with several meters optical path length are used in the conventional Faraday spectroscopy, the detuning of the lock point can be extended much further from the alkali metal resonance. A plate beam splitter was used to generate two different Faraday signals at the same time. The transmitted optical path length was L=50  mm and the reflected optical path length was 2L=100  mm. When the optical path length doubled, the detuning of the lock points moved further away from the atomic resonance. The temperature dependence of the detuning of the lock point was also analyzed. A temperature-insensitive lock point was found near resonance when the cell temperature was between 110°C and 130°C. We achieved an rms fluctuation of 0.9 MHz/23 h at a detuning of 0.5 GHz. A frequency drift of 16 MHz/h at a detuning of -5.6  GHz and 4 MHz/h at a detuning of -5.2  GHz were also obtained for the transmitted and reflected light Faraday signal.

  12. Strong interband Faraday rotation in 3D topological insulator Bi2Se3.

    Science.gov (United States)

    Ohnoutek, L; Hakl, M; Veis, M; Piot, B A; Faugeras, C; Martinez, G; Yakushev, M V; Martin, R W; Drašar, Č; Materna, A; Strzelecka, G; Hruban, A; Potemski, M; Orlita, M

    2016-01-11

    The Faraday effect is a representative magneto-optical phenomenon, resulting from the transfer of angular momentum between interacting light and matter in which time-reversal symmetry has been broken by an externally applied magnetic field. Here we report on the Faraday rotation induced in the prominent 3D topological insulator Bi2Se3 due to bulk interband excitations. The origin of this non-resonant effect, extraordinarily strong among other non-magnetic materials, is traced back to the specific Dirac-type Hamiltonian for Bi2Se3, which implies that electrons and holes in this material closely resemble relativistic particles with a non-zero rest mass.

  13. Dispersion of Electric-Field-Induced Faraday Effect in Magnetoelectric Cr2O3

    Science.gov (United States)

    Wang, Junlei; Binek, Christian

    2016-03-01

    The frequency dependence of the electric-field-induced magneto-optical Faraday effect is investigated in the magnetoelectric antiferromagnet chromia. Two electrically induced Faraday signals superimpose in proportion to the linear magnetoelectric susceptibility α and the antiferromagnetic order parameter η . The relative strength of these contributions is determined by the frequency of the probing light and can be tuned between extreme characteristics following the temperature dependence of α or η . The frequency dependence is analyzed in terms of electric dipole transitions of perturbed Cr3 + crystal-field states. The results allow us to measure voltage-controlled selection, isothermal switching, and temperature dependence of η in a tabletop setup. The voltage-specific Faraday rotation is independent of the sample thickness, making the method scalable and versatile down to the limit of dielectric breakdown.

  14. Stochastic Faraday rotation induced by the electric current fluctuations in nanosystems

    Science.gov (United States)

    Smirnov, D. S.; Glazov, M. M.

    2017-01-01

    We demonstrate theoretically that in gyrotropic semiconductors and semiconductor nanosystems the Brownian motion of electrons results in temporal fluctuations of the polarization plane of light passing through or reflected from the structure, i.e., in stochastic Faraday or Kerr rotation effects. The theory of the effects is developed for a number of prominent gyrotropic systems such as bulk tellurium, ensembles of chiral carbon nanotubes, and GaAs-based quantum wells of different crystallographic orientations. We show that the power spectrum of these fluctuations in thermal equilibrium is proportional to the a c conductivity of the system. We evaluate contributions resulting from the fluctuations of the electric current, as well as of spin, valley polarization, and the spin current to the noise of the Faraday/Kerr rotation. Hence all-optical measurements of the Faraday and Kerr rotation noise provide an access to the transport properties of the semiconductor systems.

  15. Cavity-enhanced Faraday rotation measurement with auto-balanced photodetection.

    Science.gov (United States)

    Chang, Chia-Yu; Shy, Jow-Tsong

    2015-10-01

    Optical cavity enhancement for a tiny Faraday rotation is demonstrated with auto-balanced photodetection. This configuration is analyzed using the Jones matrix formalism. The resonant rotation signal is amplified, and thus, the angular sensitivity is improved. In the experiment, the air Faraday rotation is measured with an auto-balanced photoreceiver in single-pass and cavity geometries. The result shows that the measured Faraday rotation in the single-pass geometry is enhanced by a factor of 85 in the cavity geometry, and the sensitivity is improved to 7.54×10(-10)  rad Hz(-1/2), which agrees well with the Jones matrix analysis. With this verification, we propose an AC magnetic sensor whose magnetic sensitivity is expected to achieve 10  pT Hz(-1/2).

  16. Cup Anemometer Overspeeding

    DEFF Research Database (Denmark)

    Busch, N. E.; Kristensen, Leif

    1976-01-01

    Statistical considerations are applied to a general equation of motion for cup anemometers in a turbulent wind. It is shown that the relative overspeeding ΔS/S can be expressed as ΔS/S = Ih2 · Js(l0/Λs) + cIw2, where Is and Iw are the horizontal and the vertical turbulence intensifies, respectively....... The function Js depends on the shape of the spectrum of horizontal turbulent energy, l0 is the distance constant for the anemometer, and Λs is a characteristic length scale of the horizontal turbulence. The constant c is of order unity. If Λs is suitably chosen as the scale of the energy-containing eddies...

  17. Testing the Solar Probe Cup, an Instrument Designed to Touch the Sun

    Science.gov (United States)

    Whittlesey, Phyllis L.; Case, Anthony W.; Kasper, Justin Christophe; Wright, Kenneth H., Jr.; Alterman, Ben; Cirtain, Jonathan W.; Bookbinder, Jay; Korreck, Kelly E.; Stevens, Michael Louis

    2014-01-01

    Solar Probe Plus will be the first, fastest, and closest mission to the sun, providing the first direct sampling of the sub-Alfvenic corona. The Solar Probe Cup (SPC) is a unique re-imagining of the traditional Faraday Cup design and materials for immersion in this high temperature environment. Sending an instrument of this type into a never-seen particle environment requires extensive characterization prior to launch to establish sufficient measurement accuracy and instrument response. To reach this end, a slew of tests for allowing SPC to see ranges of appropriate ions and electrons, as well as a facility that reproduces solar photon spectra and fluxes for this mission. Having already tested the SPC at flight like temperatures with no significant modification of the noise floor, we recently completed a round of particle testing to see if the deviations in Faraday Cup design fundamentally change the operation of the instrument. Results and implications from these tests will be presented, as well as performance comparisons to cousin instruments such as those on the WIND spacecraft.

  18. The gravitational analog of Faraday's induction law

    Science.gov (United States)

    Zile, Daniel; Overduin, James

    2015-04-01

    Michael Faraday, the discoverer of electromagnetic induction, was convinced that there must also be a gravitational analog of this law, and he carried out drop-tower experiments in 1849 to look for the electric current induced in a coil by changes in gravitational flux through the coil. This work, now little remembered, was in some ways the first investigation of what we would now call a unified-field theory. We revisit Faraday's experiments in the light of current knowledge and ask what might be learned if they were to be performed today. We then review the gravitational analog for Faraday's law that arises within the vector (or gravito-electromagnetic) approximation to Einstein's theory of general relativity in the weak-field, low-velocity limit. This law relates spinning masses and induced ``mass currents'' rather than spinning charges and electric currents, but is otherwise remarkably similar to its electromagnetic counterpart. The predicted effects are completely unobservable in everyday settings like those envisioned by Faraday, but are thought to be relevant in astrophysical contexts like the accretion disks around collapsed stars, thus bearing out Faraday's remarkable intuition. Undergraduate student.

  19. Agreement in Measurement of Optic Cup-to-Disc Ratio with Stereo Biomicroscope Funduscopy and Digital Image Analysis: Results from the Nigeria National Blindness and Visual Impairment Survey.

    Science.gov (United States)

    Kyari, Fatima; Gilbert, Clare

    2017-02-01

    To determine agreement in estimations of vertical cup-to-disc ratio (VCDR) between clinical stereo-biomicroscopic funduscopy and digital fundus image analysis. Systematic sampling of 1-in-7 from a sample of 13,591 participants aged ≥40 years gave a subsample who were examined in detail. VCDR was estimated clinically by 60 diopter aspheric lens biomicroscopic funduscopy (c-VCDR) and by digital fundus images (i-VCDR) graded at the Moorfields Eye Hospital Reading Centre. Spearman's correlation coefficient, paired t-test and the Bland-Altman method to assess limits of agreement (LOA) between the two methods were applied. Of 1759 participants in the subsample, 848 participants (48%) with normal frequency doubling technology (FDT) visual fields and data for i-VCDR and c-VCDR in both eyes (n = 1696 eyes) were included in the analysis. By absolute difference of VCDR values for each eye between the two methods, 1585 eyes (94%) differed by ≤0.2. Mean i-VCDR was 0.381 (standard deviation, SD 0.156), and mean c-VCDR 0.321 (SD 0.145). i-VCDRs were significantly larger by a mean difference of 0.061 (SD 0.121; 95% confidence interval, CI, 0.055-0.066; p Digital image analysis and clinical assessment are two distinct methods to measure VCDR; with larger i-VCDRs in this survey. Applying i-VCDR cut-off values to c-VCDR measurements in the Nigeria Blindness Survey might have underestimated glaucoma prevalence. It is recommended that all participants in glaucoma surveys have VCDR by digital image measurement.

  20. Mode-locking via dissipative Faraday instability

    Science.gov (United States)

    Tarasov, Nikita; Perego, Auro M.; Churkin, Dmitry V.; Staliunas, Kestutis; Turitsyn, Sergei K.

    2016-08-01

    Emergence of coherent structures and patterns at the nonlinear stage of modulation instability of a uniform state is an inherent feature of many biological, physical and engineering systems. There are several well-studied classical modulation instabilities, such as Benjamin-Feir, Turing and Faraday instability, which play a critical role in the self-organization of energy and matter in non-equilibrium physical, chemical and biological systems. Here we experimentally demonstrate the dissipative Faraday instability induced by spatially periodic zig-zag modulation of a dissipative parameter of the system--spectrally dependent losses--achieving generation of temporal patterns and high-harmonic mode-locking in a fibre laser. We demonstrate features of this instability that distinguish it from both the Benjamin-Feir and the purely dispersive Faraday instability. Our results open the possibilities for new designs of mode-locked lasers and can be extended to other fields of physics and engineering.

  1. The hyperfine Paschen-Back Faraday effect

    CERN Document Server

    Zentile, Mark A; Weller, Lee; Knappe, Svenja; Adams, Charles S; Hughes, Ifan G

    2014-01-01

    We investigate experimentally and theoretically the Faraday effect in an atomic medium in the hyperfine Paschen-Back regime, where the Zeeman interaction is larger than the hyperfine splitting. We use a small permanent magnet and a micro-fabricated vapour cell, giving magnetic fields of the order of a Tesla. We show that for low absorption and small rotation angles, the refractive index is well approximated by the Faraday rotation signal, giving a simple way to measure the atomic refractive index. Fitting to the atomic spectra, we achieve magnetic field sensitivity at the $10^{-4}$ level. Finally we note that the Faraday signal shows zero crossings which can be used as temperature insensitive error signals for laser frequency stabilisation at large detuning. The theoretical sensitivity for $^{87}$Rb is found to be $\\sim 40$ kHz/$^\\circ$C.

  2. The hyperfine Paschen-Back Faraday effect

    Science.gov (United States)

    Zentile, Mark A.; Andrews, Rebecca; Weller, Lee; Knappe, Svenja; Adams, Charles S.; Hughes, Ifan G.

    2014-04-01

    We investigate experimentally and theoretically the Faraday effect in an atomic medium in the hyperfine Paschen-Back regime, where the Zeeman interaction is larger than the hyperfine splitting. We use a small permanent magnet and a micro-fabricated vapour cell, giving magnetic fields of the order of a tesla. We show that for low absorption and small rotation angles, the refractive index is well approximated by the Faraday rotation signal, giving a simple way to measure the atomic refractive index. Fitting to the atomic spectra, we achieve magnetic field sensitivity at the 10-4 level. Finally we note that the Faraday signal shows zero crossings which can be used as temperature insensitive error signals for laser frequency stabilization at large detuning. The theoretical sensitivity for 87Rb is found to be ˜40 kHz °C-1.

  3. Faraday polarization fluctuations of satellite beacon signals

    Science.gov (United States)

    Lee, M. C.; Klobuchar, J. A.

    1988-01-01

    The anisotropic effects of random density irregularities in causing Faraday polarization fluctuations of VHF radio signals are examined, taking both rod-like and sheet-like irregularities into consideration. It is found that the variance of Faraday polarization fluctuations depends on the ratio of perpendicular to parallel correlation lengths. The anisotropic effect of rod-like ionospheric irregularities are shown to be most appreciable for longitudinal propagation. The anisotropic effect of sheet-like ionospheric irregularities, however, is not strongly dependent on the radio propagation angle. During transionospheric propagation at large angles with respect to the geomagnetic field, sheet-like irregularities may cause greater Faraday polarization fluctuations than rod-like irregularities.

  4. Faraday waves under time-reversed excitation.

    Science.gov (United States)

    Pietschmann, Dirk; Stannarius, Ralf; Wagner, Christian; John, Thomas

    2013-03-01

    Do parametrically driven systems distinguish periodic excitations that are time mirrors of each other? Faraday waves in a Newtonian fluid are studied under excitation with superimposed harmonic wave forms. We demonstrate that the threshold parameters for the stability of the ground state are insensitive to a time inversion of the driving function. This is a peculiarity of some dynamic systems. The Faraday system shares this property with standard electroconvection in nematic liquid crystals [J. Heuer et al., Phys. Rev. E 78, 036218 (2008)]. In general, time inversion of the excitation affects the asymptotic stability of a parametrically driven system, even when it is described by linear ordinary differential equations. Obviously, the observed symmetry has to be attributed to the particular structure of the underlying differential equation system. The pattern selection of the Faraday waves above threshold, on the other hand, discriminates between time-mirrored excitation functions.

  5. Mode-locking via dissipative Faraday instability.

    Science.gov (United States)

    Tarasov, Nikita; Perego, Auro M; Churkin, Dmitry V; Staliunas, Kestutis; Turitsyn, Sergei K

    2016-08-09

    Emergence of coherent structures and patterns at the nonlinear stage of modulation instability of a uniform state is an inherent feature of many biological, physical and engineering systems. There are several well-studied classical modulation instabilities, such as Benjamin-Feir, Turing and Faraday instability, which play a critical role in the self-organization of energy and matter in non-equilibrium physical, chemical and biological systems. Here we experimentally demonstrate the dissipative Faraday instability induced by spatially periodic zig-zag modulation of a dissipative parameter of the system-spectrally dependent losses-achieving generation of temporal patterns and high-harmonic mode-locking in a fibre laser. We demonstrate features of this instability that distinguish it from both the Benjamin-Feir and the purely dispersive Faraday instability. Our results open the possibilities for new designs of mode-locked lasers and can be extended to other fields of physics and engineering.

  6. On cup anemometer rotor aerodynamics.

    Science.gov (United States)

    Pindado, Santiago; Pérez, Javier; Avila-Sanchez, Sergio

    2012-01-01

    The influence of anemometer rotor shape parameters, such as the cups' front area or their center rotation radius on the anemometer's performance was analyzed. This analysis was based on calibrations performed on two different anemometers (one based on magnet system output signal, and the other one based on an opto-electronic system output signal), tested with 21 different rotors. The results were compared to the ones resulting from classical analytical models. The results clearly showed a linear dependency of both calibration constants, the slope and the offset, on the cups' center rotation radius, the influence of the front area of the cups also being observed. The analytical model of Kondo et al. was proved to be accurate if it is based on precise data related to the aerodynamic behavior of a rotor's cup.

  7. Aerodynamic characteristics of anemometer cups

    Science.gov (United States)

    Brevoort, M J; Joyner, U T

    1934-01-01

    The static lift and drag forces on three hemispherical and two conical cups were measured over a range of angles of attack from 0 degrees to 180 degrees and a range of Reynolds Numbers from very small up to 400,000. The problems of supporting the cup for measurement and the effect of turbulence were also studied. The results were compared with those of other investigators.

  8. Terahertz spectroscopy on Faraday and Kerr rotations in a quantum anomalous Hall state.

    Science.gov (United States)

    Okada, Ken N; Takahashi, Youtarou; Mogi, Masataka; Yoshimi, Ryutaro; Tsukazaki, Atsushi; Takahashi, Kei S; Ogawa, Naoki; Kawasaki, Masashi; Tokura, Yoshinori

    2016-07-20

    Electrodynamic responses from three-dimensional topological insulators are characterized by the universal magnetoelectric term constituent of the Lagrangian formalism. The quantized magnetoelectric coupling, which is generally referred to as topological magnetoelectric effect, has been predicted to induce exotic phenomena including the universal low-energy magneto-optical effects. Here we report the experimental indication of the topological magnetoelectric effect, which is exemplified by magneto-optical Faraday and Kerr rotations in the quantum anomalous Hall states of magnetic topological insulator surfaces by terahertz magneto-optics. The universal relation composed of the observed Faraday and Kerr rotation angles but not of any material parameters (for example, dielectric constant and magnetic susceptibility) well exhibits the trajectory towards the fine structure constant in the quantized limit.

  9. Spoon-to-Cup Fading as Treatment for Cup Drinking in a Child with Intestinal Failure

    Science.gov (United States)

    Groff, Rebecca A.; Piazza, Cathleen C.; Zeleny, Jason R.; Dempsey, Jack R.

    2011-01-01

    We treated a child with intestinal failure who consumed solids on a spoon but not liquids from a cup. We used spoon-to-cup fading, which consisted of taping a spoon to a cup and then gradually moving the bowl of the spoon closer to the edge of the cup. Spoon-to-cup fading was effective for increasing consumption of liquids from a cup. (Contains 2…

  10. ionFR: Ionospheric Faraday rotation [Dataset

    NARCIS (Netherlands)

    Sotomayor-Beltran, C.; et al., [Unknown; Hessels, J.W.T.; van Leeuwen, J.; Markoff, S.; Wijers, R.A.M.J.

    2013-01-01

    IonFR calculates the amount of ionospheric Faraday rotation for a specific epoch, geographic location, and line-of-sight. The code uses a number of publicly available, GPS-derived total electron content maps and the most recent release of the International Geomagnetic Reference Field. ionFR can be

  11. Faraday Rotation and L Band Oceanographic Measurements

    DEFF Research Database (Denmark)

    Skou, Niels

    2003-01-01

    Spaceborne radiometric measurements of the L band brightness temperature over the oceans make it possible to estimate sea surface salinity. However, Faraday rotation in the ionosphere disturbs the signals and must be corrected. Two different ways of assessing the disturbance directly from...

  12. Faraday Rotation and L Band Oceanographic Measurements

    DEFF Research Database (Denmark)

    Skou, Niels

    2003-01-01

    Spaceborne radiometric measurements of the L band brightness temperature over the oceans make it possible to estimate sea surface salinity. However, Faraday rotation in the ionosphere disturbs the signals and must be corrected. Two different ways of assessing the disturbance directly from...

  13. Reflections of a Faraday Challenge Day Leader

    Science.gov (United States)

    Sewell, Keira

    2014-01-01

    Keira Sewell has just finished her second year as a Challenge Leader for the Faraday Challenge, a STEM-based scheme run by the Institution of Engineering and Technology. Aimed at 12-13 year-old students, its purpose is to engage students in future careers in engineering. Each year, a new challenge is held in over sixty schools and universities…

  14. The Minus Sign in Faraday's Law Revisited

    Science.gov (United States)

    O'Sullivan, Colm; Hurley, Donal

    2013-01-01

    By introducing the mathematical concept of orientation, the significance of the minus sign in Faraday's law may be made clear to students with some knowledge of vector calculus. For many students, however, the traditional approach of treating the law as a relationship between positive scalars and of relying on Lenz's law to provide the information…

  15. FARADAY CUP AWARD: High Sensitivity Tune Measurement using Direct Diode Detection

    CERN Document Server

    Gasior, M

    2012-01-01

    Direct Diode Detection (3D) is a technique developed at CERN initially for the LHC tune measurement system, to reach a sensitivity allowing observation of beam betatron oscillations with amplitudes below a micrometre. In this technique simple peak diode detectors are used to convert short beam pulses from a beam position pick-up into slowly varying signals. Their DC components, constituting a large background related to beam offsets, are suppressed by series capacitors, while the small signals related to beam oscillations are passed to the subsequent stages for amplification and filtering. As the demodulated beam oscillation signals are already in the kHz range, their processing is simple and they can be digitised with high resolution audio ADCs. This paper presents the history as well as the adventures of the 3D development and prototyping, along with some technical details. It documents a very efficient collaboration between CERN and Brookhaven National Laboratory (BNL), with contributions from other labora...

  16. Faraday-cup Control and Measurement Program Based on MS Windows

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    Faraday-cupControlandMeasurementProgramBasedonMSWindows¥ZhangGuixuandLuXueqiuAnewfaraday-cupcontrolprogramwhichrunsonMSWindow...

  17. High Density Faraday Cup Array or Other Open Trench Structures and Method of Manufacture Thereof

    Science.gov (United States)

    Bower, Christopher A. (Inventor); Gilchrist, Kristin Hedgepath (Inventor); Stoner, Brian R. (Inventor)

    2014-01-01

    A detector array and method for making the detector array. The detector array includes a substrate including a plurality of trenches formed therein, and a plurality of collectors electrically isolated from each other, formed on the walls of the trenches, and configured to collect charged particles incident on respective ones of the collectors and to output from the collectors signals indicative of charged particle collection. In the detector array, adjacent ones of the plurality of trenches are disposed in a staggered configuration relative to one another. The method forms in a substrate a plurality of trenches across a surface of the substrate such that adjacent ones of the trenches are in a staggered sequence relative to one another, forms in the plurality of trenches a plurality of collectors, and connects a plurality of electrodes respectively to the collectors.

  18. Faraday Cup Array Integrated with a Readout IC and Method for Manufacture Thereof

    Science.gov (United States)

    Bower, Christopher A. (Inventor); Hedgepath Gilchrist, Kristin (Inventor); Stoner, Brian R. (Inventor); Temple, Dorota (Inventor)

    2014-01-01

    A detector array and method for making the detector array. The array includes a substrate including a plurality of trenches formed therein, and includes a plurality of collectors electrically isolated from each other, formed on the walls of the trenches, and configured to collect charge particles incident on respective ones of the collectors and to output from said collectors signals indicative of charged particle collection. The array includes a plurality of readout circuits disposed on a side of the substrate opposite openings to the collectors. The readout circuits are configured to read charge collection signals from respective ones of the plurality of collectors.

  19. Can A Cup Anemometer `Underspeed'?

    Science.gov (United States)

    Kristensen, L.

    An analysis of cup-anemometer dynamics has been carried out inorder to determine whether the mean-wind velocity can have anegative bias. This would be contrary to the general belief thatcup anemometers always overspeed. Compared to prior analyses, theeffect of a possible nonlinearity of the calibration function isincluded. The conclusion is that neither longitudinal nor lateralvelocity fluctuations can contribute significantly to a negativebias. However, if a cup anemometer has an angular response thatfalls below the ideal cosine response, there will, as demonstratedin the concluding discussion, be a negative contribution from thevertical velocity fluctuations to the total bias, and thiscontribution may even outbalance the positive contributions fromthe longitudinal velocity fluctuations. Concrete evidence of suchexotic cup anemometer behaviour has not been reported in theliterature.

  20. Faraday effect of bismuth iron garnet thin film prepared by mist CVD method

    Science.gov (United States)

    Yao, Situ; Sato, Takafumi; Kaneko, Kentaro; Murai, Shunsuke; Fujita, Koji; Tanaka, Katsuhisa

    2015-06-01

    Metastable bismuth iron garnet (BIG, an abbreviation of Bi3Fe5O12), one kind of garnet-type ferrites, is known to manifest very large Faraday rotation as well as low optical absorption in the visible to infrared region. We report on successful synthesis of thin film composed of single-phase BIG epitaxially grown on single-crystalline gadolinium gallium garnet (Gd3Ga5O12, GGG) substrate by using mist chemical vapor deposition (CVD) method, which is an emerging technique for preparation of thin films. The crystal structure, surface morphology, and magnetic, optical and magneto-optical properties of the resultant thin films have been explored. The BIG thin film has a relatively flat surface free from roughness compared to those prepared by other vapor deposition methods. Saturation magnetization is about 1620 G at room temperature, which is close to that expected from the ideal magnetic structure of BIG. The maximum value of Faraday rotation angle reaches 54.3 deg/µm at a wavelength of 424 nm. This value is rather large when compared with those reported for BIG thin films prepared by other techniques. The wavelength dependence of Faraday rotation angle is analyzed well in terms of the crystal electric field (CEF) level schema. Our result suggests that the mist CVD method is a simple and effective technique to synthesize BIG thin film with excellent magneto-optical properties.

  1. Stray-field-induced Faraday contributions in wide-field Kerr microscopy and -magnetometry

    Energy Technology Data Exchange (ETDEWEB)

    Markó, D.; Soldatov, I. [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Institute for Metallic Materials, PO 270116, D-01171 Dresden (Germany); Dresden University of Technology, Institute for Materials Science, D-01062 Dresden (Germany); Tekielak, M. [Institute of Experimental Physics, University of Bialystok, Lipowa 41, Bialystok 15-424 Poland (Poland); Schäfer, R., E-mail: r.schaefer@ifw-dresden.de [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Institute for Metallic Materials, PO 270116, D-01171 Dresden (Germany); Dresden University of Technology, Institute for Materials Science, D-01062 Dresden (Germany)

    2015-12-15

    The magnetic domain contrast in wide-field Kerr microscopy on bulk specimens can be substantially distorted by non-linear, field-dependent Faraday rotations in the objective lens that are caused by stray-field components emerging from the specimen. These Faraday contributions, which were detected by Kerr-magnetometry on grain-oriented iron–silicon steel samples, are thoroughly elaborated and characterized. They express themselves as a field-dependent gray-scale offset to the domain contrast and in highly distorted surface magnetization curves if optically measured in a wide field Kerr microscope. An experimental method to avoid such distortions is suggested. In the course of these studies, a low-permeability part in the surface magnetization loop of slightly misoriented (110)-surfaces in iron–silicon sheets was discovered that is attributed to demagnetization effects in direction perpendicular to the sheet surface. - Highlights: • Magnetizing a finite sample in a Kerr microscope leads to sample-generated stray-fields. • They cause non-linear, field- and position-dependent Faraday rotations in the objective. • This leads to a modulation of the Kerr contrast and to distorted MOKE loops. • A method to compensate these Faraday rotations is presented.

  2. Multifrequency transverse Faraday effect in single magneto-dielectric microspheres

    CERN Document Server

    Maksymov, Ivan S

    2014-01-01

    We propose using a single magneto-dielectric microsphere as a device for enhancing the transverse Faraday effect at multiple wavelengths at the same time. Although the diameter of the sphere can be $<1$ $\\mu$m, the numerically predicted strength of its magneto-optical (MO) response can be an order of magnitude stronger than in MO devices based on thick magnetic plates. The MO response of a microsphere is also comparable with that of subwavelength magneto-dielectric gratings which, however, operate at a single wavelength and occupy a large area. In contrast to gratings and thick plates, the compact size of the microsphere and its capability to support spin-wave excitations make it suitable for applications in nanophotonics, imaging systems, and magnonics.

  3. THz near-field Faraday imaging in hybrid metamaterials.

    Science.gov (United States)

    Kumar, Nishant; Strikwerda, Andrew C; Fan, Kebin; Zhang, Xin; Averitt, Richard D; Planken, Paul C M; Adam, Aurèle J L

    2012-05-07

    We report on direct measurements of the magnetic near-field of metamaterial split ring resonators at terahertz frequencies using a magnetic field sensitive material. Specifically, planar split ring resonators are fabricated on a single magneto-optically active terbium gallium garnet crystal. Normally incident terahertz radiation couples to the resonator inducing a magnetic dipole oscillating perpendicular to the crystal surface. Faraday rotation of the polarisation of a near-infrared probe beam directly measures the magnetic near-field with 100 femtosecond temporal resolution and (λ/200) spatial resolution. Numerical simulations suggest that the magnetic field can be enhanced in the plane of the resonator by as much as a factor of 200 compared to the incident field strength. Our results provide a route towards hybrid devices for dynamic magneto-active control of light such as isolators, and highlight the utility of split ring resonators as compact probes of magnetic phenomena in condensed matter.

  4. Aerodynamic Investigation of a Cup Anemometer

    Science.gov (United States)

    Hubbard, John D; Brescoll, George P

    1934-01-01

    This thesis presents the results of an investigation wherein the change of the normal force coefficient with Reynolds Number was obtained statically for a 15.5-centimeter hemisphere cup under the following conditions: (1) single cup with no interference; (2) single cup with three-cup interference; (3) four cups. The coefficients found in this research vary with Reynolds Number and are high as compared with those of Eiffel. The effect of interference upon a single cup is to increase the drag and normal force coefficients. The curve resulting from the summation of the coefficients for four cups agrees with the static torque curve of a Robinson type cup anemometer. All tests were carried on in the University of Detroit atmospheric wind tunnel during May 1933.

  5. Transfer matrix approach for the Kerr and Faraday rotation in layered nanostructures

    Science.gov (United States)

    Széchenyi, Gábor; Vigh, Máté; Kormányos, Andor; Cserti, József

    2016-09-01

    To study the optical rotation of the polarization of light incident on multilayer systems consisting of atomically thin conductors and dielectric multilayers we present a general method based on transfer matrices. The transfer matrix of the atomically thin conducting layer is obtained using the Maxwell equations. We derive expressions for the Kerr (Faraday) rotation angle and for the ellipticity of the reflected (transmitted) light as a function of the incident angle and polarization of the light. The method is demonstrated by calculating the Kerr (Faraday) angle for bilayer graphene in the quantum anomalous Hall state placed on the top of dielectric multilayers. The optical conductivity of the bilayer graphene is calculated in the framework of a four-band model.

  6. Transfer matrix approach for the Kerr and Faraday rotation in layered nanostructures.

    Science.gov (United States)

    Széchenyi, Gábor; Vigh, Máté; Kormányos, Andor; Cserti, József

    2016-09-21

    To study the optical rotation of the polarization of light incident on multilayer systems consisting of atomically thin conductors and dielectric multilayers we present a general method based on transfer matrices. The transfer matrix of the atomically thin conducting layer is obtained using the Maxwell equations. We derive expressions for the Kerr (Faraday) rotation angle and for the ellipticity of the reflected (transmitted) light as a function of the incident angle and polarization of the light. The method is demonstrated by calculating the Kerr (Faraday) angle for bilayer graphene in the quantum anomalous Hall state placed on the top of dielectric multilayers. The optical conductivity of the bilayer graphene is calculated in the framework of a four-band model.

  7. Giant magneto-optical Faraday effect of Fe-Al2O3 films prepared by sol-gel techniques%溶胶-凝胶法制备Fe-Al2O3巨磁旋光薄膜

    Institute of Scientific and Technical Information of China (English)

    戴敏; 卜胜利; 孙国庆; 顾铮(一先)

    2010-01-01

    用溶胶一凝胶法制备了Fe-Al2O3铁磁金属一非磁绝缘体基体薄膜.实验结果表明,当Fe与Al2O3的质量比为1:1,热处理温度为420℃时,所制备的薄膜具有最大的磁致旋光(Faraday)效应,测得的费尔德(Verdet)常数V=(6.8X104)°/(T·cm).通过分析,得出了Fe-Al2O3薄膜巨磁Faraday旋光效应主要是由光、磁场与薄膜相互作用产生剧烈塞曼(Zeeman)分裂引起的.对影响薄膜Faraday旋光效应的各种主要因素进行了讨论.

  8. Cup tool use by squirrel monkeys.

    Science.gov (United States)

    Buckmaster, Christine L; Hyde, Shellie A; Parker, Karen J; Lyons, David M

    2015-12-01

    Captive-born male and female squirrel monkeys spontaneously 'invented' a cup tool use technique to Contain (i.e., hold and control) food they reduced into fragments for consumption and to Contain water collected from a valve to drink. Food cup use was observed more frequently than water cup use. Observations indicate that 68% (n = 39/57) of monkeys in this population used a cup (a plastic slip cap) to Contain food, and a subset of these monkeys, 10% (n = 4/39), also used a cup to Contain water. Cup use was optional and did not replace, but supplemented, the hand/arm-to-mouth eating and direct valve drinking exhibited by all members of the population. Strategies monkeys used to bring food and cups together for food processing activity at preferred upper-level perching areas, in the arboreal-like environment in which they lived, provides evidence that monkeys may plan food processing activity with the cups. Specifically, prior to cup use monkeys obtained a cup first before food, or obtained food and a cup from the floor simultaneously, before transporting both items to upper-level perching areas. After food processing activity with cups monkeys rarely dropped the cups and more often placed the cups onto perching. Monkeys subsequently returned to use cups that they previously placed on perching after food processing activity. The latter behavior is consistent with the possibility that monkeys may keep cups at preferred perching sites for future food processing activity and merits experimental investigation. Reports of spontaneous tool use by squirrel monkeys are rare and this is the first report of population-level tool use. These findings offer insights into the cognitive abilities of squirrel monkeys and provide a new context for behavior studies with this genus and for comparative studies with other primates.

  9. La electricidad antes de Faraday. Parte 2

    Directory of Open Access Journals (Sweden)

    Gabriel Poveda Ramos

    2004-01-01

    Full Text Available Esta es la segunda y última parte de este artículo, cuya primera parte fue publicada en el número anterior de esta revista. Esta parte cubre el período de la Edad Moderna posterior al Renacimiento, hasta llegar a Faraday. Presenta los descubrimientos y los inventos que en este tramo de historia se hicieron en la teoría y en la experimentación en el campo de la electricidad, los cuales forman parte muy importante de esa ciencia, con el nombre de electrostática. Esta parte final (y el artículo completo llegan hasta Faraday porque este gran científico reunió en un solo cuerpo de conocimientos la electricidad y el magnetismo.

  10. 21 CFR 884.5400 - Menstrual cup.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Menstrual cup. 884.5400 Section 884.5400 Food and... OBSTETRICAL AND GYNECOLOGICAL DEVICES Obstetrical and Gynecological Therapeutic Devices § 884.5400 Menstrual cup. (a) Identification. A menstrual cup is a receptacle placed in the vagina to collect...

  11. La electricidad antes de Faraday. Parte 1

    Directory of Open Access Journals (Sweden)

    Gabriel Poveda Ramos

    2003-01-01

    Full Text Available Este documento es una monografía sobre el surgimiento y el desarrollo de la ciencia de la electricidad desde la remota antigüedad hasta la época de Michael Faraday, a comienzos del siglo XIX. Está escrito con el propósito de reunirlo con otro que el autor ya escribió sobre la historia del magnetismo durante el mismo período.

  12. Faraday Pilot-Waves: Generation and Propagation

    Science.gov (United States)

    Galeano-Rios, Carlos; Milewski, Paul; Nachbin, André; Bush, John

    2015-11-01

    We examine the dynamics of drops bouncing on a fluid bath subjected to vertical vibration. We solve a system of linear PDEs to compute the surface wave generation and propagation. Waves are triggered at each bounce, giving rise to the Faraday pilot-wave field. The model captures several of the behaviors observed in the laboratory, including transitions between a variety of bouncing and walking states, the Doppler effect, and droplet-droplet interactions. Thanks to the NSF.

  13. Dynamic square superlattice of Faraday waves

    Science.gov (United States)

    Kahouadji, Lyes; Chergui, Jalel; Juric, Damir; Shin, Seungwon; Tuckerman, Laurette

    2014-11-01

    Faraday waves are computed in a 3D container using BLUE, a code based on a hybrid Front-Tracking/Level-set algorithm for Lagrangian tracking of arbitrarily deformable phase interfaces. A new dynamic superlattice pattern is described which consists of a set of square waves arranged in a two-by-two array. The corners of this array are connected by a bridge whose position oscillates in time between the two diagonals.

  14. Coffee Cup Atomic Force Microscopy

    Science.gov (United States)

    Ashkenaz, David E.; Hall, W. Paige; Haynes, Christy L.; Hicks, Erin M.; McFarland, Adam D.; Sherry, Leif J.; Stuart, Douglas A.; Wheeler, Korin E.; Yonzon, Chanda R.; Zhao, Jing; Godwin, Hilary A.; Van Duyne, Richard P.

    2010-01-01

    In this activity, students use a model created from a coffee cup or cardstock cutout to explore the working principle of an atomic force microscope (AFM). Students manipulate a model of an AFM, using it to examine various objects to retrieve topographic data and then graph and interpret results. The students observe that movement of the AFM…

  15. Coffee Cup Atomic Force Microscopy

    Science.gov (United States)

    Ashkenaz, David E.; Hall, W. Paige; Haynes, Christy L.; Hicks, Erin M.; McFarland, Adam D.; Sherry, Leif J.; Stuart, Douglas A.; Wheeler, Korin E.; Yonzon, Chanda R.; Zhao, Jing; Godwin, Hilary A.; Van Duyne, Richard P.

    2010-01-01

    In this activity, students use a model created from a coffee cup or cardstock cutout to explore the working principle of an atomic force microscope (AFM). Students manipulate a model of an AFM, using it to examine various objects to retrieve topographic data and then graph and interpret results. The students observe that movement of the AFM…

  16. A Faraday rotation diagnostic for Z pinch experiments

    Science.gov (United States)

    Gao, K. W.; Intrator, T. P.; Weber, T. E.; Yoo, C. B.; Klarenbeek, J.

    2012-10-01

    The MagLIF experiment is an approach to Magneto Inertial Fusion (MIF) that will compress a laser preheated magnetized plasma inside a small sub cm size beryllium capsule and the magnetic field inside. A good measurement of the compressed magnetic field will help us understand how the compression proceeds, and the time scale over which field diffuses out. We are working on a first step to the direct measurement of vacuum magnetic field (expected to be mostly Bz) compression time history, potentially space-resolved, without a plasma fill. A small magneto-active section of optical fiber can measure magnetic fields in the 1-1000 Tesla range. Directly measured vacuum Bz is an initial but important step towards validating the codes supporting MagLIF. The technology will use a Terbium doped optical fiber as a Faraday rotation medium. The optical path and hardware is simple, inexpensive, and small enough to fit inside a MagLIF capsule, and can be radiation hardened. Low noise, optically coupled magnetic field measurements will be possible for vacuum MagLIF shots.

  17. MUSIC for Faraday rotation measure synthesis

    Science.gov (United States)

    Andrecut, M.

    2013-03-01

    Faraday rotation measure (RM) synthesis requires the recovery of the Faraday dispersion function (FDF) from measurements restricted to limited wavelength ranges, which is an ill-conditioned deconvolution problem. Here, we propose a novel deconvolution method based on an extension of the MUltiple SIgnal Classification (MUSIC) algorithm. The complexity and speed of the method is determined by the eigen-decomposition of the covariance matrix of the observed polarizations. We show numerically that for high to moderate signal-to-noise ratio (S/N) cases the RM-MUSIC method is able to recover the Faraday depth values of closely spaced pairs of thin RM components, even in situations where the peak response of the FDF is outside of the RM range between the two input RM components. This result is particularly important because the standard deconvolution approach based on RM-CLEAN fails systematically in such situations, due to its greedy mechanism used to extract the RM components. For low S/N situations, both the RM-MUSIC and RM-CLEAN methods provide similar results.

  18. MUSIC for Faraday Rotation Measure Synthesis

    CERN Document Server

    Andrecut, M

    2013-01-01

    Faraday Rotation Measure (RM) synthesis requires the recovery of the Faraday Dispersion Function (FDF) from measurements restricted to limited wavelength ranges, which is an ill-conditioned deconvolution problem. Here, we propose a novel deconvolution method based on an extension of the MUltiple SIgnal Classification (MUSIC) algorithm. The complexity and speed of the method is determined by the eigen-decomposition of the covariance matrix of the observed polarizations. We show numerically that for high to moderate Signal to Noise (S/N) cases the RM-MUSIC method is able to recover the Faraday depth values of closely spaced pairs of thin RM components, even in situations where the peak response of the FDF is outside of the RM range between the two input RM components. This result is particularly important because the standard deconvolution approach based on RM-CLEAN fails systematically in such situations, due to its greedy mechanism used to extract the RM components. For low S/N situations, both the RM-MUSIC a...

  19. Support for Faraday`s View of Circulation in a Fine-Powder Chladni Heap

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, B.; Squires, A.M. [Department of Chemical Engineering, Virginia Polytechnic Institute State University, Blacksburg, Virginia 24061-0211 (United States)

    1998-07-01

    Faraday, like Chladni, saw fine powder collect in a circular heap at an antinode of a vibrating plate. In each vibration cycle, the heap experiences a free-flight interval during which pressure gradients in the heap`s interior drive powder centerward, as Faraday proposed. When heap-floor collision terminates flight, pressure gradients reverse direction; but passage of a compaction front has locked particles against further movement. Before a next flight interval, an increase in porosity will reverse the compaction that accompanied heap-floor collision. {copyright} {ital 1998} {ital The American Physical Society}

  20. Competing Turing and Faraday Instabilities in Longitudinally Modulated Passive Resonators.

    Science.gov (United States)

    Copie, François; Conforti, Matteo; Kudlinski, Alexandre; Mussot, Arnaud; Trillo, Stefano

    2016-04-08

    We experimentally investigate the interplay of Turing (modulational) and Faraday (parametric) instabilities in a bistable passive nonlinear resonator. The Faraday branch is induced via parametric resonance owing to a periodic modulation of the resonator dispersion. We show that the bistable switching dynamics is dramatically affected by the competition between the two instability mechanisms, which dictates two completely novel scenarios. At low detunings from resonance, switching occurs between the stable stationary lower branch and the Faraday-unstable upper branch, whereas at high detunings we observe the crossover between the Turing and Faraday periodic structures. The results are well explained in terms of the universal Lugiato-Lefever model.

  1. Generalized Faraday law derived from classical forces in a rotating frame

    OpenAIRE

    Choi, Taeseung

    2009-01-01

    We show the additional spin dependent classical force due to the rotation of an electron spin's rest frame is essential to derive a spin-Faraday law by using an analogy with the usual Faraday law. The contribution of the additional spin dependent force to the spin-Faraday law is the same as that of the spin geometric phase. With this observations, Faraday law is generalized to include both the usual Faraday and the spin-Faraday laws in a unified manner.

  2. On Cup Anemometer Rotor Aerodynamics

    Directory of Open Access Journals (Sweden)

    Santiago Pindado

    2012-05-01

    Full Text Available The influence of anemometer rotor shape parameters, such as the cups’ front area or their center rotation radius on the anemometer’s performance was analyzed. This analysis was based on calibrations performed on two different anemometers (one based on magnet system output signal, and the other one based on an opto-electronic system output signal, tested with 21 different rotors. The results were compared to the ones resulting from classical analytical models. The results clearly showed a linear dependency of both calibration constants, the slope and the offset, on the cups’ center rotation radius, the influence of the front area of the cups also being observed. The analytical model of Kondo et al. was proved to be accurate if it is based on precise data related to the aerodynamic behavior of a rotor’s cup.

  3. Giant Faraday effect due to Pauli exclusion principle in 3D topological insulators.

    Science.gov (United States)

    Paudel, Hari P; Leuenberger, Michael N

    2014-02-26

    Experiments using ARPES, which is based on the photoelectric effect, show that the surface states in 3D topological insulators (TI) are helical. Here we consider Weyl interface fermions due to band inversion in narrow-bandgap semiconductors, such as Pb1-xSnxTe. The positive and negative energy solutions can be identified by means of opposite helicity in terms of the spin helicity operator in 3D TI as ĥ(TI) = (1/ |p|_ |) β (σ|_ x p|_ ) · z^, where β is a Dirac matrix and z^ points perpendicular to the interface. Using the 3D Dirac equation and bandstructure calculations we show that the transitions between positive and negative energy solutions, giving rise to electron-hole pairs, obey strict optical selection rules. In order to demonstrate the consequences of these selection rules, we consider the Faraday effect due to the Pauli exclusion principle in a pump-probe setup using a 3D TI double interface of a PbTe/Pb₀.₃₁Sn₀.₆₉Te/PbTe heterostructure. For that we calculate the optical conductivity tensor of this heterostructure, which we use to solve Maxwell's equations. The Faraday rotation angle exhibits oscillations as a function of probe wavelength and thickness of the heterostructure. The maxima in the Faraday rotation angle are of the order of mrds.

  4. Mixed-cation designs of magnetic perovskites for Faraday rotation at IR wavelengths

    Science.gov (United States)

    Dionne, Gerald F.; Taussig, Alexander R.; Bolduc, Martin; Bi, Lei; Ross, Caroline A.

    2007-05-01

    Magnetic garnets with Bi3+ are the standard media of discrete Faraday rotation isolators for IR-laser/fiber-optical transmission at 1.55μm wavelength. For monolithic integration with semiconductors, perovskites of generic formula A[B ]O3 offer promising alternatives that involve combinations of select transition-metal ions in octahedral B sites. In this paper, two concepts are described. In both cases, the 180° B -O-B bonding of the perovskite lattice could provide superexchange fields large enough to maintain spin ordering at room temperature. One model proposes a quasiferrite arrangement with antiferromagnetic alignment between Fe3+ and Ni2+ charge ordered in the double perovskite compound {A3+A'4+}[Fe3+Ni2+]O6. The other concept relies on ferromagnetism through delocalization superexchange with the composition A23+[Mn4+Ni2+]O6. Where appropriate to enhance Faraday rotation, Bi3+ can be used for A3+.

  5. Faraday-Active Fabry-Perot Resonator: Transmission, Reflection, and Emissivity

    Science.gov (United States)

    Liptuga, Anatoliy; Morozhenko, Vasyl; Pipa, Viktor; Venger, Evgen; Kostiuk, Theodor

    2011-01-01

    The propagation of light within a semiconductor Faraday-active Fabry-Perot resonator (FAFR) is investigated theoretically and experimentally. It is shown that an external magnetic field radically changes the angular and spectral characteristics of transmission, reflection and emissivity of the resonator not only for polarized, but also for unpolarized light. Suppression of interference patterns and phase inversion of the interference extrema were observed in both monochromatic and polychromatic light. The investigations were carried out for the plane-parallel plates of n-InAs in the spectral range of free charge carrier absorption. The results can be used to create new controllable optical and spectroscopic devices for investigation of Faraday-active material properties and for control of parameters of plane-parallel layers and structures.

  6. Faraday-effect polarimeter-interferometer system for current density measurement on EAST.

    Science.gov (United States)

    Liu, H Q; Jie, Y X; Ding, W X; Brower, D L; Zou, Z Y; Li, W M; Wang, Z X; Qian, J P; Yang, Y; Zeng, L; Lan, T; Wei, X C; Li, G S; Hu, L Q; Wan, B N

    2014-11-01

    A multichannel far-infrared laser-based POlarimeter-INTerferometer (POINT) system utilizing the three-wave technique is under development for current density and electron density profile measurements in the EAST tokamak. Novel molybdenum retro-reflectors are mounted in the inside wall for the double-pass optical arrangement. A Digital Phase Detector with 250 kHz bandwidth, which will provide real-time Faraday rotation angle and density phase shift output, have been developed for use on the POINT system. Initial calibration indicates the electron line-integrated density resolution is less than 5 × 10(16) m(-2) (∼2°), and the Faraday rotation angle rms phase noise is <0.1°.

  7. Experimental Investigation of the Robinson-Type Cup Anemometer

    Science.gov (United States)

    Brevoort, M J; Joyner, U T

    1936-01-01

    This report presents the results of wind tunnel tests on a Robinson-type anemometer. The investigation covered force measurements on individual cups, as well as static and dynamic torque measurements and calibrations on complete cup wheels. In the tests on individual cups 5 cup forms were used and in the measurements on complete cup wheels 4 cup wheels with 3 arm lengths for each cup wheel were tested. All the results are presented in graphical form.

  8. Fourier analysis of the aerodynamic behavior of cup anemometers

    OpenAIRE

    Pindado Carrion, Santiago; Pérez Sarasola, Imanol; Aguado Roca, Maite

    2013-01-01

    The calibration results (the transfer function) of an anemometer equipped with several cup rotors were analyzed and correlated with the aerodynamic forces measured on the isolated cups in a wind tunnel. The correlation was based on a Fourier analysis of the normal-to-the-cup aerodynamic force. Three different cup shapes were studied: typical conical cups, elliptical cups and porous cups (conical-truncated shape). Results indicated a good correlation between the anemometer factor, K, and the r...

  9. Factitious panniculitis induced by cupping therapy.

    Science.gov (United States)

    Moon, Suk-Ho; Han, Hyun-Ho; Rhie, Jong-Won

    2011-11-01

    Cupping therapy is an alternative medical procedure that has been widely performed in Asian countries to relieve pain. It is known that there is no complication to this therapy, so many non-health care professionals have performed this procedure. However, there have been few reports on complications, such as iron deficiency anemia, hemorrhagic bullae, kelloids, vasovagal syncope, and foreign body reactions. Masses associated with panniculitis induced by cupping are extremely rare, and they require a unique approach.A 56-year-old woman presented with a 10-month history of multiple masses in the posterior neck and right shoulder areas. The patient repeatedly attempted cupping therapy by herself, and multiple palpable masses developed in the posterior neck and right shoulder area where cupping therapy had been performed. The masses were enlarged by repeated cupping, and they decreased in size when cupping was stopped. Among all lesions, the 2 masses with tenderness were surgically excised. The remaining masses resolved after cupping therapy was ceased. When a patient with subcutaneous mass has a history of cupping or trace of cupping marks, panniculitis induced by cupping should be suspected. The lesion seems to spontaneously resolve unless they are repeatedly stimulated. However, surgical resection is considered in patients with infections or severe tenderness as a complication.

  10. Inverse Faraday Effect driven by Radiation Friction

    CERN Document Server

    Liseykina, T V; Macchi, A

    2015-01-01

    In the interaction of extremely intense ($>10^{23}~\\mbox{W cm}^{-2}$), circularly polarized laser pulses with thick targets, theory and simulations show that a major fraction of the laser energy is converted into incoherent radiation because of collective electron motion during the "hole boring" dynamics. The effective dissipation due to radiative losses allows the absorption of electromagnetic angular momentum, which in turn leads to the generation of an axial magnetic field of tens of gigagauss value. This peculiar "inverse Faraday effect" is demonstrated in three-dimensional simulations including radiation friction.

  11. Observation of Phillips's spectrum in Faraday waves

    Science.gov (United States)

    Castillo, Gustavo; Falcon, Claudio

    2016-11-01

    We consider the problem of wave turbulence generated by singularities from an experimental point of view. We study a system of Faraday waves interacting with waves generated by a wave-maker driven with a random forcing. We measure the temporal fluctuations of the surface wave amplitude at a given location and we show that for a wide range of forcing parameters the surface height displays a power-law spectra that greatly differs from the one predicted by the WT theory. In the capillary region the power spectrum turns out to be proportional to f-5, which we believe is due to singularities moving across the system. Proyecto Postdoctorado Fondecyt Nro 3160032.

  12. The wavelength dependence of Faraday rotation in magnetic fluids

    Science.gov (United States)

    Yusuf, Nihad A.; Rousan, Akram A.; El-Ghanem, Hassan M.

    1988-09-01

    Measurements of Faraday rotation over the wavelength range 450-633 nm in a dilute Fe3O4 particle magnetic fluid are reported. The results, in agreement with the theory, show an enhancement of Faraday rotation near the wavelength λ≊500 nm.

  13. Rethinking Faraday's Law for Teaching Motional Electromotive Force

    Science.gov (United States)

    Zuza, Kristina; Guisasola, Jenaro; Michelini, Marisa; Santi, Lorenzo

    2012-01-01

    This study shows physicists' discussions on the meaning of Faraday's law where situations involving extended conductors or moving contact points are particularly troublesome. We raise questions to test students' difficulties in applying Faraday's law in motional electromotive force phenomena. We suggest the benefit of analysing these phenomena…

  14. Searching for Faraday rotation in cosmic microwave background polarization

    Science.gov (United States)

    Ruiz-Granados, B.; Battaner, E.; Florido, E.

    2016-08-01

    We use the Wilkinson Microwave Anisotropy Probe (WMAP) 9th-year foreground reduced data at 33, 41 and 61 GHz to derive a Faraday rotation at map and at angular power spectrum levels taking into account their observational errors. A processing mask provided by WMAP is used to avoid contamination from the disc of our Galaxy and local spurs. We have found a Faraday rotation component at both, map and power spectrum levels. The lack of correlation of the Faraday rotation with Galactic Faraday rotation, synchrotron and dust polarization from our Galaxy or with cosmic microwave background anisotropies or lensing suggests that it could be originated at reionization (ℓ ≲ 12). Even if the detected Faraday rotation signal is weak, the present study could contribute to establish magnetic fields strengths of B0 ˜ 10-8 G at reionization.

  15. Cupping for hypertension: a systematic review.

    Science.gov (United States)

    Lee, Myeong Soo; Choi, Tae-Young; Shin, Byung-Cheul; Kim, Jong-In; Nam, Sang-Soo

    2010-01-01

    The objective of this review is to assess the clinical evidence for or against cupping as a treatment for hypertension. We searched the literature using 15 databases from their inception to 30 June 2009, without language restrictions. We included all clinical trials (CTs) of cupping to treat hypertension in human patients. Risk of bias was assessed using the Cochrane criteria. Two CTs met all inclusion criteria. One RCT (randomized CT) assessed the effectiveness of dry cupping on changes in cerebral vascular function compared with drug therapy. Their results suggested significant effect in favor of cupping on vascular compliance and degree of vascular filling. One uncontrolled observational study (UOS) tested wet cupping for acute hypertension and found that a one-time treatment reduced blood pressure. In conclusion, the evidence is not significantly convincing to suggest cupping is effective for treating hypertension. Further research is required to investigate whether it generates any specific effects for that condition.

  16. Analytical balance-based Faraday magnetometer

    Science.gov (United States)

    Riminucci, Alberto; Uhlarz, Marc; De Santis, Roberto; Herrmannsdörfer, Thomas

    2017-03-01

    We introduce a Faraday magnetometer based on an analytical balance in which we were able to apply magnetic fields up to 0.14 T. We calibrated it with a 1 mm Ni sphere previously characterized in a superconducting quantum interference device (SQUID) magnetometer. The proposed magnetometer reached a theoretical sensitivity of 3 × 10-8 A m2. We demonstrated its operation on magnetic composite scaffolds made of poly(ɛ-caprolactone)/iron-doped hydroxyapatite. To confirm the validity of the method, we measured the same scaffold properties in a SQUID magnetometer. The agreement between the two measurements was within 5% at 0.127 T and 12% at 24 mT. With the addition, for a small cost, of a permanent magnet and computer controlled linear translators, we were thus able to assemble a Faraday magnetometer based on an analytical balance, which is a virtually ubiquitous instrument. This will make simple but effective magnetometry easily accessible to most laboratories, in particular, to life sciences ones, which are increasingly interested in magnetic materials.

  17. Preinjector for Linac 1, Faraday cage

    CERN Multimedia

    1974-01-01

    The 50 MeV Linac 1 started up in 1958 as injector to the 26 GeV PS, with a 520 kV Cockcroft-Walton generator as its preinjector, housed in a vast Faraday cage, visible here. When the Cockcroft-Walton broke down in 1973, it was replaced by a much smaller SAMES generator, of the kind used for electrostatic separators. From 1980 on, Linac 2 took over as injector for the 800 MeV Booster, and Linac 1 continued as injector for LEAR. In 1984, the electrostatic preinjector (i.e. the Faraday cage with its contents, SAMES generator and all) was replaced by a 520 keV RFQ. At the lower left corner we see the HV connectors to the SAMES generator, at the right edge part of the opened electronics-platform. Jean-Luc Vallet sees to it that all parts are properly grounded. See also 7403073X, 7403074X, 7403081X, 7403083X.

  18. Observation of Phillips' spectrum in Faraday waves

    CERN Document Server

    Castillo, Gustavo

    2016-01-01

    We report the observation of the Phillips' spectrum of gravity surface waves driven by a horizontally moving wave maker interacting with Faraday waves. We measure the temporal fluctuations of the surface wave amplitude at a given location and we show that, for a wide range of forcing parameters, they display a power-law spectrum that greatly differs from the one predicted by the WT theory but coincides with Phillips' spectrum for gravity waves. We compute the probability density function of the local surface height increments, which show that they change strongly across time scales. The structure functions of these increments are shown to display power-laws as a function of the time lag, with exponents that are not linear with the order of the structure function, thus showing that the wave field is intermittent. We argue that the origin of this scale-invariant intermittent spectrum is the Faraday wave pattern breakup due to its advection by the propagating gravity waves, which can be related directly to the P...

  19. Faraday rotation measure synthesis of UGC 10288

    Science.gov (United States)

    Kamieneski, Patrick; Wang, Q. Daniel; Pare, Dylan; Sullivan, Kendall

    2017-01-01

    Faraday rotation measure synthesis is a powerful tool that has been employed in the past decade when studying line-of-sight magnetic fields of galactic and extragalactic sources. Rotation measures, which are sensitive to the strength and direction of fields in an intervening medium between the source and observer, were classically determined by assuming a single, uniform Faraday-rotating medium. Rotation measure synthesis, on the other hand, is a more robust method that allows for probing a more complicated scenario. We will outline results from a study of magnetic field structure in the disk and halo of edge-on galaxy UGC 10288, using 6 cm and 20 cm observations from CHANG-ES (Continuum Halos in Nearby Galaxies - an EVLA Survey). The presence of a strongly polarized complex background source situated perpendicular to the foreground disk allows for an investigation of the disk-halo magnetic fields of UGC 10288. In particular, we present evidence of magnetic field reversals above the plane of the disk. This finding is not easily explained solely by the prevailing α-Ω dynamo mechanism. Rather, a field reversal may be indicative of different parities of the poloidal field components for the individual disk and halo mechanisms.

  20. Lamp with a truncated reflector cup

    Science.gov (United States)

    Li, Ming; Allen, Steven C.; Bazydola, Sarah; Ghiu, Camil-Daniel

    2013-10-15

    A lamp assembly, and method for making same. The lamp assembly includes first and second truncated reflector cups. The lamp assembly also includes at least one base plate disposed between the first and second truncated reflector cups, and a light engine disposed on a top surface of the at least one base plate. The light engine is configured to emit light to be reflected by one of the first and second truncated reflector cups.

  1. Field calibration of cup anemometers

    DEFF Research Database (Denmark)

    Kristensen, L.; Jensen, G.; Hansen, A.

    2001-01-01

    An outdoor calibration facility for cup anemometers, where the signals from 10 anemometers of which at least one is a reference can be can be recorded simultaneously, has been established. The results are discussed with special emphasis on the statisticalsignificance of the calibration expressions....... It is concluded that the method has the advantage that many anemometers can be calibrated accurately with a minimum of work and cost. The obvious disadvantage is that the calibration of a set of anemometersmay take more than one month in order to have wind speeds covering a sufficiently large magnitude range...

  2. Faraday effect in alkali-metal vapors in a strong bichromatic field of laser light

    Science.gov (United States)

    Karagodova, T. Ya.; Kuptsova, A. V.

    2002-04-01

    Results of a numerical study of the Faraday effect arising upon propagation of the light beams with the frequencies ω L1 (resonant to the nS 1/2- nP 1/2, 3/2 transitions) and ω L2 (resonant to the nP 1/2, 3/2-( n+2) S 1/2 transitions) through alkali-metal vapors are presented. Characteristics of the magneto-optical rotation spectra at each of the frequencies are strongly affected by the second intense radiation field resonant to the adjacent transition. When the atoms interact with two strong light waves, resonant to adjacent transitions, and with a magnetic field, the shape of the Faraday rotation spectra depends on the energy shifts of the atomic states that arise due to the dynamic Stark effect and the Zeeman effect (the Paschen-Back or an intermediate-type effect), as well as due to the difference of populations of these states caused by the interaction of the atoms with the fields. The results obtained show that in the frequency selection method, based on the resonance Faraday effect, the frequency of the generated narrow-band beam can be tuned by the intensity of the strong wave, resonant to the transition between the excited states.

  3. The RSC Faraday prize lecture of 1989 on platinum.

    Science.gov (United States)

    Thomas, John Meurig

    2017-08-25

    In 1861, Michael Faraday gave one of his last Friday Evening Discourses at the Royal Institution of Great Britain, London, on platinum, which he described as "this beautiful, magnificent and valuable metal". More than a hundred and twenty years later (in 1989), the author re-enacted, at the Royal Institution, many of the demonstrations that Faraday carried out in his memorable Discourse. This article outlines many of Faraday's views on, and experiments with, platinum. It also describes the continuing importance and utilization of platinum, both as perceived in 1989 and from present perspectives.

  4. Faraday Conversion in Turbulent Blazar Jets

    CERN Document Server

    MacDonald, Nicholas R

    2016-01-01

    Low ($\\lesssim 3\\%$) levels of circular polarization (CP) detected at radio frequencies in the relativistic jets of some blazars can provide insight into the underlying nature of the jet plasma. CP can be produced through linear birefringence, in which initially linearly polarized emission produced in one region of the jet is altered by Faraday rotation as it propagates through other regions of the jet with various magnetic field orientations. Marscher has recently begun a study of jets with such magnetic geometries with the Turbulent Extreme Multi-Zone (TEMZ) model, in which turbulent plasma crossing a standing shock in the jet is represented by a collection of thousands of individual plasma cells, each with distinct magnetic field orientation. Here we develop a radiative transfer scheme that allows the numerical TEMZ code to produce simulated images of the time-dependent linearly and circularly polarized intensity at different radio frequencies. In this initial study, we produce synthetic polarized emission...

  5. Internal Subharmonic Resonance in Faraday Experiment

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-Long; CHEN Yi-Huang; WEI Rong-Jue

    2000-01-01

    The classical Faraday experiment is a tractable problem in nonlinear physics, and its rich spectrum of nonlinear phenomena has made it a prototype in studying nonlinear wave dynamics in general. Here we report the ob servation of a new type of subharmonic resonances which occurs at some smaller fractional frequencies, such as ν/3, ν/4, and ν/6, where ν is the forcing frequency. As a result of these resonances, the lower-order surface-wave modes whose eigenfrequencies are close to the fractional frequencies participate into the wave motions. Our theory involving quadratically nonlinear mode couplings shows that an already excited mode itself can act as a parametric source on the lower-order primary modes, thus leading to the cascading subharmonic resonances.

  6. Bone remodeling around cementless tantalum cups

    NARCIS (Netherlands)

    Grillo, J. -C.; Flecher, X.; Bouvenot, J.; Argenson, J. -N.

    2008-01-01

    Purpose of the study.-Most studies have reported a significant decrease in periacetabular bone stock one year after implantation of a cementless cup. The purpose of this work was to study the bone-implant interface of the tantalum cup using plain X-rays and dual-energy X-ray absorptiometry (DEXA). M

  7. Soccer jersey sponsors and the world cup

    NARCIS (Netherlands)

    Groot, L.F.M.; Ferwerda, J.

    2014-01-01

    The market for soccer jerseys is a multibillion market dominated by Adidas, Nike and Puma. This paper investigates whether jersey sponsorship has a non-arbitrary effect on the outcomes of World Cup knockout matches. The results show that in the knockout stages of the last four World Cup tournaments,

  8. Testing Ionospheric Faraday Rotation Corrections in CASA

    Science.gov (United States)

    Kooi, Jason E.; Moellenbrock, George

    2015-04-01

    The Earth’s ionosphere introduces direction- and time-dependent effects over a range of physical and temporal scales and so is a major source for unmodeled phase offsets for low frequency radioastronomical observations. Ionospheric effects are often the limiting factor to making sensitive radioastronomical measurements to probe the solar corona or coronal mass ejections at low frequencies (CASA) package. CASA, which was developed to meet the data post-processing needs of next generation telescopes such as the Karl G. Jansky Very Large Array (VLA), did not previously have the capability to mitigate ionospheric effects. This algorithm uses GPS-based global ionosphere maps to mitigate the first and second order ionospheric effects (dispersion delay and Faraday rotation, respectively). We investigated several data centers as potential sources for global ionospheric models and chose the International Global Navigation Satellite System Service data product because data from other sources are generally too sparse to use without additional interpolation schemes. This implementation of ionospheric corrections in CASA has been tested on several sets of VLA observations and all of them showed a significant reduction of the dispersion delay. In order to rigorously test CASA’s ability to mitigate ionospheric Faraday rotation, we made VLA full-polarization observations of the standard VLA phase calibrators J0359+5057 and J0423+4150 in August 2014, using L band (1 - 2 GHz), S band (2 - 4 GHz), and C band (4 - 6 GHz) frequencies in the D array configuration. The observations were 4 hours in duration, beginning near local sunrise. In this paper, we give a general description of how these corrections are implemented as well as discussion of the code’s ability to mitigate the ionospheric effects present in these test observations over a range of times and elevation angles. This work was supported at the University of Iowa by grant ATM09-56901.

  9. Fourier analysis of the aerodynamic behavior of cup anemometers

    Science.gov (United States)

    Pindado, Santiago; Pérez, Imanol; Aguado, Maite

    2013-06-01

    The calibration results (the transfer function) of an anemometer equipped with several cup rotors were analyzed and correlated with the aerodynamic forces measured on the isolated cups in a wind tunnel. The correlation was based on a Fourier analysis of the normal-to-the-cup aerodynamic force. Three different cup shapes were studied: typical conical cups, elliptical cups and porous cups (conical-truncated shape). Results indicated a good correlation between the anemometer factor, K, and the ratio between the first two coefficients in the Fourier series decomposition of the normal-to-the-cup aerodynamic force.

  10. Vacuum extraction: a randomized controlled comparison of the New Generation cup with the original Bird cup.

    Science.gov (United States)

    Carmody, F; Grant, A; Somchiwong, M

    1986-01-01

    A new design of vacuum extractor cup--'the New Generation cup'--has recently been introduced into clinical practice. Its major modification is a traction cord which passes around the rim of the cup for 180 degrees and is free to slide within the rim. Claims that this design 'enables the operator to pull obliquely without causing the cup to tilt' and thereby 'reduces failure rates, reduces the incidence of scalp trauma and increases operator confidence' have been evaluated in a randomized controlled trial. 123 women with singleton pregnancies of 37 completed weeks or more, with a cephalic presentation and for whom a decision to deliver by vacuum extraction had been taken, were randomly allocated to the 'New Generation' cup or BIRD's original vacuum extractor cup; 50 mm anterior and posterior cups were used in both groups as appropriate. The two groups were comparable at entry and delivered by obstetricians of similar status. The two types of cup were similar in respect of number of failures to deliver with the vacuum extractor, correct positioning of the cup, number of pulls required for delivery and time taken to expedite delivery. Cup detachments occurred in nine cases allocated to the 'New Generation' cup compared with four allocated to the original BIRD cup. The babies in the two groups were in similar condition at birth and sustained similar amounts of scalp trauma. Neonatal jaundice, both clinical and biochemical, was more common in babies delivered with the 'New Generation cup' and this was reflected in greater use of phototherapy in this group. Operators were equally divided in their preference of cup.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. One-Piece Faraday Generator: A Paradoxical Experiment from 1851

    Science.gov (United States)

    Crooks, M. J.; And Others

    1978-01-01

    Describes an experiment based on Faraday's one-piece generator, where the rotating disk is replaced by a cylindrical permanent magnet. Explains the apparent paradox that an observer in an inertial frame could measure his absolute velocity. (GA)

  12. The Faraday effect of natural and artificial ferritins.

    Science.gov (United States)

    Koralewski, M; Kłos, J W; Baranowski, M; Mitróová, Z; Kopčanský, P; Melníková, L; Okuda, M; Schwarzacher, W

    2012-09-07

    Measurements of the Faraday rotation at room temperature over the light wavelength range of 300-680 nm for horse spleen ferritin (HSF), magnetoferritin with different loading factors (LFs) and nanoscale magnetite and Fe(2)O(3) suspensions are reported. The Faraday rotation and the magnetization of the materials studied present similar magnetic field dependences and are characteristic of a superparamagnetic system. The dependence of the Faraday rotation on the magnetic field is described, excluding HSF and Fe(2)O(3), by a Langevin function with a log-normal distribution of the particle size allowing the core diameters of the substances studied to be calculated. It was found that the specific Verdet constant depends linearly on the LF. Differences in the Faraday rotation spectra and their magnetic field dependences allow discrimination between magnetoferritin with maghemite and magnetite cores which can be very useful in biomedicine.

  13. Field calibration of cup anemometers

    Energy Technology Data Exchange (ETDEWEB)

    Kristensen, L.; Jensen, G.; Hansen, A.; Kirkegaard, P.

    2001-01-01

    An outdoor calibration facility for cup anemometers, where the signals from 10 anemometers of which at least one is a reference can be recorded simultaneously, has been established. The results are discussed with special emphasis on the statistical significance of the calibration expressions. It is concluded that the method has the advantage that many anemometers can be calibrated accurately with a minimum of work and cost. The obvious disadvantage is that the calibration of a set of anemometers may take more than one month in order to have wind speeds covering a sufficiently large magnitude range in a wind direction sector where we can be sure that the instruments are exposed to identical, simultaneous wind flows. Another main conclusion is that statistical uncertainty must be carefully evaluated since the individual 10 minute wind-speed averages are not statistically independent. (au)

  14. Magnetism and Faraday Rotation in Oxygen-Deficient Polycrystalline and Single-Crystal Iron-Substituted Strontium Titanate

    Science.gov (United States)

    Goto, Taichi; Kim, Dong Hun; Sun, Xueyin; Onbasli, Mehmet C.; Florez, Juan M.; Ong, Shyue Ping; Vargas, Patricio; Ackland, Karl; Stamenov, Plamen; Aimon, Nicolas M.; Inoue, Mitsuteru; Tuller, Harry L.; Dionne, Gerald F.; Coey, J. Michael D.; Ross, Caroline A.

    2017-02-01

    Both polycrystalline and single-crystal films of iron-substituted strontium titanate, Sr (Ti0.65Fe0.35)O3 -δ , prepared by pulsed laser deposition, show room-temperature magnetism and Faraday rotation, with the polycrystalline films exhibiting higher saturation magnetization and Faraday rotation. The magnetic properties vary with the oxygen pressure at which the films are grown, showing a maximum at pressures of approximately 4 μ Torr at which the unit-cell volume is largest. The results are discussed in terms of the oxygen stoichiometry and corresponding Fe valence states, the structure and strain state, and the presence of small-volume fractions of metallic Fe in single-crystal films grown at the optimum deposition pressure. Integration of magneto-optical polycrystalline films on an optical-waveguide device demonstrates a nonreciprocal phase shift.

  15. Faraday rotation due to excitation of magnetoplasmons in graphene microribbons.

    Science.gov (United States)

    Tymchenko, Mykhailo; Nikitin, Alexey Yu; Martín-Moreno, Luis

    2013-11-26

    A single graphene sheet, when subjected to a perpendicular static magnetic field, provides a Faraday rotation that, per atomic layer, greatly surpasses that of any other known material. In continuous graphene, Faraday rotation originates from the cyclotron resonance of massless carriers, which allows dynamical tuning through either external electrostatic or magneto-static setting. Furthermore, the rotation direction can be controlled by changing the sign of the carriers in graphene, which can be done by means of an external electric field. However, despite these tuning possibilities, the requirement of large magnetic fields hinders the application of the Faraday effect in real devices, especially for frequencies higher than a few terahertz. In this work we demonstrate that large Faraday rotation can be achieved in arrays of graphene microribbons, through the excitation of the magnetoplasmons of individual ribbons, at larger frequencies than those dictated by the cyclotron resonance. In this way, for a given magnetic field and chemical potential, structuring graphene periodically can produce large Faraday rotation at larger frequencies than what would occur in a continuous graphene sheet. Alternatively, at a given frequency, graphene ribbons produce large Faraday rotation at much smaller magnetic fields than in continuous graphene.

  16. Faraday effect improvement by Dy{sup 3+}-doping of terbium gallium garnet single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhe, E-mail: zhenzhe1201@sina.com; Yang, Lei; Hang, Yin; Wang, Xiangyong

    2016-01-15

    Highly transparent Dy{sup 3+}-doped terbium gallium garnet (TGG) single crystal was grown by Czochralski (Cz) method. Phase composition of the crystal was tested by XRD measurements. The distribution coefficient of Dy{sup 3+} in the crystal was obtained. The optical and magneto-optical properties were analyzed in detail, and magnetic properties of the Dy{sup 3+}-TGG crystal were studied. The paramagnetic behavior is observed down to 10 K. The as-grown crystal exhibited high optical transmittance, particularly in the visible region. The Faraday rotation was investigated over visible and near-infrared regions (VIS–NIR) at room temperature. The Verdet constants increase at measured wavelengths and high thermal stability was found in Dy{sup 3+}-doped TGG, as compared to the properties of pure TGG, indicating that Dy{sup 3+}-doped crystals are preferable for magneto-active materials used in Faraday devices at VIS–NIR wavelengths. - Graphical abstract: Highly transparent Dy{sup 3+}-doped terbium gallium garnet (TGG) and pure TGG single crystals were grown by Czochralski method. The Dy{sup 3+}-doped TGG possesses 20–30% higher Verdet values in reference to TGG independently on wavelength.

  17. Electrogyration and Faraday rotation in pure and Cr-doped lead germanate crystals

    Energy Technology Data Exchange (ETDEWEB)

    Adamenko, D; Klymiv, I; Vlokh, R; Vlokh, O [Institute of Physical Optics, 23 Dragomanov Street, 79005 Lviv (Ukraine); Duda, V M [Dnipropetrovsk National University, 13 Naukova Street, Dnipropetrovsk (Ukraine)], E-mail: vlokh@ifo.lviv.ua

    2008-02-20

    We present the results of studies on the temperature dependence of the electrogyration (EG) effect, Faraday rotation and natural optical activity in Pb{sub 5}Ge{sub 3}O{sub 11} and Pb{sub 5}Ge{sub 3}O{sub 11}:Cr crystals at the phase transition. A high EG coefficient is found for Pb{sub 5}Ge{sub 3}O{sub 11}:Cr crystals. We demonstrate how the Curie-Weiss constant, the critical exponents of the order parameter and the dielectric permittivity in Pb{sub 5}Ge{sub 3}O{sub 11}:Cr crystals, as well as the coefficients of thermodynamic potential, could be derived from the temperature dependences of optical activity and the EG coefficient. We also show that the increment of the Faraday rotation in Pb{sub 5}Ge{sub 3}O{sub 11} and Pb{sub 5}Ge{sub 3}O{sub 11}:Cr crystals appearing at the phase transition is caused by a combined magneto-electrooptic effect induced by spontaneous polarization. It is proportional to the square of spontaneous polarization. The phenomenon revealed by us corresponds to combined effects of crystal optics, which appear due to the common action of different fields.

  18. Linear diffusion into a Faraday cage.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin; Lin, Yau Tang; Merewether, Kimball O.; Chen, Kenneth C.

    2011-11-01

    Linear lightning diffusion into a Faraday cage is studied. An early-time integral valid for large ratios of enclosure size to enclosure thickness and small relative permeability ({mu}/{mu}{sub 0} {le} 10) is used for this study. Existing solutions for nearby lightning impulse responses of electrically thick-wall enclosures are refined and extended to calculate the nearby lightning magnetic field (H) and time-derivative magnetic field (HDOT) inside enclosures of varying thickness caused by a decaying exponential excitation. For a direct strike scenario, the early-time integral for a worst-case line source outside the enclosure caused by an impulse is simplified and numerically integrated to give the interior H and HDOT at the location closest to the source as well as a function of distance from the source. H and HDOT enclosure response functions for decaying exponentials are considered for an enclosure wall of any thickness. Simple formulas are derived to provide a description of enclosure interior H and HDOT as well. Direct strike voltage and current bounds for a single-turn optimally-coupled loop for all three waveforms are also given.

  19. Fluctuation dynamos and their Faraday rotation signatures

    CERN Document Server

    Bhat, Pallavi

    2012-01-01

    Turbulence is ubiquitous in many astrophysical systems like galaxies, galaxy clusters and possibly even the IGM filaments. We study fluctuation dynamo action in turbulent systems focusing on one observational signature; the Faraday rotation measure (RM) from background radio sources seen through the magnetic field generated by such a dynamo. We simulate the fluctuation dynamo (FD) in periodic boxes up to resolutions of 512^3, with varying fluid and magnetic Reynolds numbers, and measure the resulting random RMs. We show that the resulting rms value of RM is quite significant, given that the FD produces intermittent fields. When the dynamo saturates, it is of order 40%-50% of the value expected in a model where fields of strength B_rms uniformly fill cells of the largest turbulent eddy but are randomly oriented from one cell to another. This level of RM dispersion obtains across different values of magnetic Reynolds number and Prandtl number explored. We also use the random RMs to probe the structure of the ge...

  20. Magnetic moment of a single metal nanoparticle determined from the Faraday effect

    Science.gov (United States)

    Szczytko, Jacek; Vaupotič, Nataša; Madrak, Karolina; Sznajder, Paweł; Górecka, Ewa

    2013-03-01

    Optical properties of a composite material made of ferromagnetic metal nanoparticles embedded in a dielectric host are studied. We constructed an effective dielectric tensor of the composite material taking into account the orientational distribution of nanoparticle magnetic moments in external magnetic field. A nonlinear dependence of the optical rotation on magnetic field resulting from the reorientation of nanoparticles is demonstrated. The theoretical findings were applied to the magneto-optical experimental data of cobalt ferromagnetic nanoparticles embedded in a dielectric liquid host. The dependence of the Faraday rotation on Co-based ferromagnetic nanoparticles was measured as a function of the external magnetic field, varying the size of nanoparticles and the wavelength of light. The proposed approach enables quantitative determination of the magnetic moment and the plasma frequency of a single nanoparticle, and from this the size of the nonmagnetic shell of magnetic nanoparticles.

  1. Does Cupping = Success for Olympic Athletes?

    Science.gov (United States)

    ... news/fullstory_160301.html Does 'Cupping' = Success for Olympic Athletes? Telltale red circles of ancient Chinese practice ... Eyebrows raised in Rio over the weekend when Olympic athletes like swimmer Michael Phelps started showing up ...

  2. Clear plastic cups: a childhood choking hazard.

    Science.gov (United States)

    Weiss, R L; Goldstein, M N; Dharia, A; Zahtz, G; Abramson, A L; Patel, M

    1996-11-01

    The disposable plastic beverage cup is not usually regarded as hazardous to young children. Certain varieties of these products however, are manufactured from a brittle, clear plastic that easily cracks and fragments. While most conscientious parents keep their children safe from peanuts, balloons, and other known choking hazards, a child can surreptitiously bite a cup edge and aspirate the fragment. We report two cases of foreign body aspiration involving clear plastic cups that went undetected one of which remained 21 months following a negative rigid bronchoscopy. Diagnostic difficulties are related to the transparency and radiolucency of these objects. When suspicious of foreign body aspiration in children, otolaryngologists should inquire about the availability of clear plastic cups in the household and be mindful of the diagnostic pitfalls. Further investigations including CT scanning and repeat bronchoscopy may be helpful in cases of suspected missed foreign bodies. An educational campaign aimed at prevention and placement of product package warning labels should be established.

  3. Paradoxical thinning of the retinal nerve fiber layer after reversal of cupping: A case report of primary infantile glaucoma

    Directory of Open Access Journals (Sweden)

    Ta Chen Chang

    2016-01-01

    Full Text Available The circumpapillary retinal nerve fiber layer (RNFL thickness was assessed by spectral domain optical coherent tomography (SD-OCT before and after surgical reduction of intraocular pressure in an eye with primary infantile glaucoma. In this case, a postoperative reduction of cupping and a subsequent increase in neuroretinal rim area is associated with a paradoxical thinning of the RNFL. This is the first-known characterization of cupping reversal using SD-OCT.

  4. [Study on the mechanisms of cupping therapy].

    Science.gov (United States)

    Hong, Shou-Hai; Wu, Fei; Lu, Xuan; Cai, Qing; Guo, Yi

    2011-10-01

    Computerized literature searches are performed for articles of the mechanism of cupping therapy in the past 10 years. The mechanism of action of local negative pressure applied to human body is studied in terms of specific changes in local tissue structure, stretch to the nerve and muscle, increasing blood circulation and causing autohemolysis. This paper aims to explain the mechanism of cupping therapy according to modern science.

  5. Some developments on cup anemometer aerodynamics

    OpenAIRE

    Pindado Carrion, Santiago; Cubas Cano, Javier

    2014-01-01

    In the present study the geometry of cups is experimentally studied through anemometer performance. This performance is analyzed in two different ways. On the one hand the anemometer transfer function between cases is compared. On the other hand the stationary rotation speed is decomposed into constant and harmonic terms, the comparison being established between the last ones. Results indicate that some cup shapes can improve the uniformity of anemometer rotation, this fact being important to...

  6. Distance constant of the Risoe cup anemometer

    Energy Technology Data Exchange (ETDEWEB)

    Kristensen, L.; Frost Hansen, O.

    2002-04-01

    The theory for cup-anemometer dynamics is presented in some detail and two methods of obtaining the distance constant . are discussed. The first method is based on wind tunnel measurements: with a constant wind speed the cup anemometer is released from a locked position of the rotor and the increasing rotation rate recorded. It is concluded that the rapid increase in rotation rate makes the method very inaccurate. The second method consists of an analysis of turbulent, atmospheric of wind speed as measured by the cup anemometer and a fast-responding sonic anemometer with a spatial eddy resolution which is significantly better than that which can be obtained by a cup anemometer. The ratio between the measured power spectra of the horizontal wind speed by the two instruments contains the necessary information for determining the response characteristics of the cup anemometer and thereby .. The conditions for this last method to be accurate are discussed. Field measurements are used to demonstrate how . is determined the Riso cup anemometer, model P2546.

  7. High-Throughput, Protein-Targeted Biomolecular Detection Using Frequency-Domain Faraday Rotation Spectroscopy.

    Science.gov (United States)

    Murdock, Richard J; Putnam, Shawn A; Das, Soumen; Gupta, Ankur; Chase, Elyse D Z; Seal, Sudipta

    2017-01-16

    A clinically relevant magneto-optical technique (fd-FRS, frequency-domain Faraday rotation spectroscopy) for characterizing proteins using antibody-functionalized magnetic nanoparticles (MNPs) is demonstrated. This technique distinguishes between the Faraday rotation of the solvent, iron oxide core, and functionalization layers of polyethylene glycol polymers (spacer) and model antibody-antigen complexes (anti-BSA/BSA, bovine serum albumin). A detection sensitivity of ≈10 pg mL(-1) and broad detection range of 10 pg mL(-1) ≲ cBSA ≲ 100 µg mL(-1) are observed. Combining this technique with predictive analyte binding models quantifies (within an order of magnitude) the number of active binding sites on functionalized MNPs. Comparative enzyme-linked immunosorbent assay (ELISA) studies are conducted, reproducing the manufacturer advertised BSA ELISA detection limits from 1 ng mL(-1) ≲ cBSA ≲ 500 ng mL(-1) . In addition to the increased sensitivity, broader detection range, and similar specificity, fd-FRS can be conducted in less than ≈30 min, compared to ≈4 h with ELISA. Thus, fd-FRS is shown to be a sensitive optical technique with potential to become an efficient diagnostic in the chemical and biomolecular sciences.

  8. Anomalous Faraday rotation in the ISM/ICM

    Science.gov (United States)

    Medvedev, Mikhail V.

    2016-10-01

    Faraday effect is a common and useful way to deduce cosmic magnetic fields in the interstellar and intracluster media (ISM and ICM). Faraday rotation is the result of magnetically-induced birefringence in a dielectric medium causing a linearly polarized wave to suffer a rotation of its polarization axis as it traverses such a medium. However, the standard λ2-law of the rotation angle may not hold in strongly turbulent plasmas. Electromagnetic high-frequency and/or small-scale fluctuations may lead to effective collisionality with the pitch-angle diffusion coefficient being an effective ``quasi-collision'' frequency. Recently, we showed that quasi-collisionality may radically alter radiative transport properties of plasmas, such as absorption, transmission and reflection and other effects, which can be very important in laboratory and astrophysical plasmas. Here we briefly discuss the quasi-collisional generalization of the classical Faraday effect, which is drastically modified and can even become negative. Furthermore, we explore the origin of the long-known anomaly of Faraday rotation in a famous Cygnus regions. We argue that the anomaly can be due to the anomalous Faraday rotation in a thin ``blanket'' of turbulent plasma at the front of an interstellar bubble/shock. Supported by KU CLAS and DOE Grant ID0000225143 (07/01/16).

  9. Faraday instability in a near-critical fluid under weightlessness.

    Science.gov (United States)

    Gandikota, G; Chatain, D; Amiroudine, S; Lyubimova, T; Beysens, D

    2014-01-01

    Experiments on near-critical hydrogen have been conducted under magnetic compensation of gravity to investigate the Faraday instability that arises at the liquid-vapor interface under zero-gravity conditions. We investigated such instability in the absence of stabilizing gravity. Under such conditions, vibration orients the interface and can destabilize it. The experiments confirm the existence of Faraday waves and demonstrate a transition from a square to a line pattern close to the critical point. They also show a transition very close to the critical point from Faraday to periodic layering of the vapor-liquid interface perpendicular to vibration. It was seen that the Faraday wave instability is favored when the liquid-vapor density difference is large enough (fluid far from the critical point), whereas periodic layering predominates for small difference in the liquid and vapor densities (close to the critical point). It was observed for the Faraday wave instability that the wavelength of the instability decreases as one approaches the critical point. The experimental results demonstrate good agreement to the dispersion relation for zero gravity except for temperatures very close to the critical point where a transition from a square pattern to a line pattern is detected, similarly to what is observed under 1g conditions.

  10. Diode laser operating on an atomic transition limited by an isotope ⁸⁷Rb Faraday filter at 780 nm.

    Science.gov (United States)

    Tao, Zhiming; Hong, Yelong; Luo, Bin; Chen, Jingbiao; Guo, Hong

    2015-09-15

    We demonstrate an extended cavity Faraday laser system using an antireflection-coated laser diode as the gain medium and the isotope (87)Rb Faraday anomalous dispersion optical filter (FADOF) as the frequency selective device. Using this method, the laser wavelength works stably at the highest transmission peak of the isotope (87)Rb FADOF over the laser diode current from 55 to 140 mA and the temperature from 15°C to 35°C. Neither the current nor the temperature of the laser diode has significant influence on the output frequency. Compared with previous extended cavity laser systems operating at frequencies irrelevant to spectacular atomic transition lines, the laser system realized here provides a stable laser source with the frequency operating on atomic transitions for many practical applications.

  11. Faraday Induction and the Current Carriers in a Circuit

    CERN Document Server

    Boyer, Timothy H

    2014-01-01

    In this article, it is pointed out that Faraday induction can be treated from an untraditional, particle-based point of view. The electromagnetic fields of Faraday induction can be calculated explicitly from approximate point-charge fields derived from the Li\\'enard-Wiechert expressions or from the Darwin Lagrangian. Thus the electric fields of electrostatics, the magnetic fields of magnetostatics, and the electric fields of Faraday induction can all be regarded as arising from charged particles. Some aspects of electromagnetic induction are explored for a hypothetical circuit consisting of point charges which move frictionlessly in a circular orbit. For a small number of particles in the circuit (or for non-interacting particles), the induced electromagnetic fields depend upon the mass and charge of the current carriers while energy is transferred to the kinetic energy of the particles. However, for an interacting multiparticle circuit, the mutual electromagnetic interactions between the particles dominate t...

  12. Faraday tomography with LOFAR: new probe of the interstellar

    Science.gov (United States)

    Alves, M. I. R.; Jelić, V.; Ferrière, K.; Boulanger, F.

    2016-12-01

    Magnetic fields are a key constituent of the interstellar medium of our Galaxy. However, their exact role in the Galactic ecosystem is still poorly understood since we do not yet have a complete view of its structure in the Galaxy. This is about to change with the Faraday tomography technique, which allows us to derive the magnetic field in separate regions along the line of sight. We first describe the principle of Faraday tomography and illustrate the power of this novel technique with some of the latest results from the LOw Frequency ARray (LOFAR). We present preliminary results of our LOFAR project, aimed at investigating the origin of the filamentary-like structures revealed by Faraday tomography observations.

  13. Evaluation of ion collection area in Faraday probes.

    Science.gov (United States)

    Brown, Daniel L; Gallimore, Alec D

    2010-06-01

    A Faraday probe with three concentric rings was designed and fabricated to assess the effect of gap width and collector diameter in a systematic study of the diagnostic ion collection area. The nested Faraday probe consisted of two concentric collector rings and an outer guard ring, which enabled simultaneous current density measurements on the inner and outer collectors. Two versions of the outer collector were fabricated to create gaps of 0.5 and 1.5 mm between the rings. Distribution of current density in the plume of a low-power Hall thruster ion source was measured in azimuthal sweeps at constant radius from 8 to 20 thruster diameters downstream of the exit plane with variation in facility background pressure. A new analytical technique is proposed to account for ions collected in the gap between the Faraday probe collector and guard ring. This method is shown to exhibit excellent agreement between all nested Faraday probe configurations, and to reduce the magnitude of integrated ion beam current to levels consistent with Hall thruster performance analyses. The technique is further studied by varying the guard ring bias potential with a fixed collector bias potential, thereby controlling ion collection in the gap. Results are in agreement with predictions based on the proposed analytical technique. The method is applied to a past study comparing the measured ion current density profiles of two Faraday probe designs. These findings provide new insight into the nature of ion collection in Faraday probe diagnostics, and lead to improved accuracy with a significant reduction in measurement uncertainty.

  14. Faraday ghosts depolarization canals in the Galactic radio emission

    CERN Document Server

    Shukurov, A M; Shukurov, Anvar; Berkhuijsen, Elly M.

    2003-01-01

    Narrow, elongated regions of very low polarized intensity -- so-called canals -- have recently been observed by several authors at decimeter wavelengths in various directions in the Milky Way, but their origin remains enigmatic. We show that the canals arise from depolarization by differential Faraday rotation in the interstellar medium and that they represent level lines of Faraday rotation measure RM, a random function of position in the sky. Statistical properties of the separation of canals depend on the autocorrelation function of RM, and so provide a useful tool for studies of interstellar turbulence.

  15. Dynamic Chiral Magnetic Effect and Faraday Rotation in Macroscopically Disordered Helical Metals

    Science.gov (United States)

    Ma, J.; Pesin, D. A.

    2017-03-01

    We develop an effective medium theory for electromagnetic wave propagation through gapless nonuniform systems with a dynamic chiral magnetic effect. The theory allows us to calculate macroscopic-disorder-induced corrections to the values of optical, as well as chiral magnetic conductivities. In particular, we show that spatial fluctuations of the optical conductivity induce corrections to the effective value of the chiral magnetic conductivity. The absolute value of the effect varies strongly depending on the system parameters, but yields the leading frequency dependence of the polarization rotation and circular dichroism signals. Experimentally, these corrections can be observed as features in the Faraday rotation angle near frequencies that correspond to the bulk plasmon resonances of a material. Such features are not expected to be present in single-crystal samples.

  16. ACCUWIND - Methods for classification of cup anemometers

    DEFF Research Database (Denmark)

    Dahlberg, J.-Å.; Friis Pedersen, Troels; Busche, P.

    2006-01-01

    Errors associated with the measurement of wind speed are the major sources of uncertainties in power performance testing of wind turbines. Field comparisons of well-calibrated anemometers show significant and not acceptable difference. The EuropeanCLASSCUP project posed the objectives to quantify...... the errors associated with the use of cup anemometers, and to develop a classification system for quantification of systematic errors of cup anemometers. This classification system has now been implementedin the IEC 61400-12-1 standard on power performance measurements in annex I and J. The classification...... of cup anemometers requires general external climatic operational ranges to be applied for the analysis of systematic errors. A Class A categoryclassification is connected to reasonably flat sites, and another Class B category is connected to complex terrain, General classification indices are the result...

  17. An updated review of the efficacy of cupping therapy.

    Directory of Open Access Journals (Sweden)

    Huijuan Cao

    Full Text Available BACKGROUND: Since 1950, traditional Chinese medicine (TCM cupping therapy has been applied as a formal modality in hospitals throughout China and elsewhere in the world. Based on a previous systematic literature review of clinical studies on cupping therapy, this study presents a thorough review of randomized controlled trials (RCTs to evaluate the therapeutic effect of cupping therapy. METHOD: Six databases were searched for articles published through 2010. RCTs on cupping therapy for various diseases were included. Studies on cupping therapy combined with other TCM treatments versus non-TCM therapies were excluded. RESULTS: 135 RCTs published from 1992 through 2010 were identified. The studies were generally of low methodological quality. Diseases for which cupping therapy was commonly applied were herpes zoster, facial paralysis (Bell palsy, cough and dyspnea, acne, lumbar disc herniation, and cervical spondylosis. Wet cupping was used in most trials, followed by retained cupping, moving cupping, and flash cupping. Meta-analysis showed cupping therapy combined with other TCM treatments was significantly superior to other treatments alone in increasing the number of cured patients with herpes zoster, facial paralysis, acne, and cervical spondylosis. No serious adverse effects were reported in the trials. CONCLUSIONS: Numerous RCTs on cupping therapy have been conducted and published during the past decades. This review showed that cupping has potential effect in the treatment of herpes zoster and other specific conditions. However, further rigorously designed trials on its use for other conditions are warranted.

  18. Simultaneous Faraday filtering of the Mollow triplet sidebands with the Cs-D1 clock transition

    Science.gov (United States)

    Portalupi, Simone Luca; Widmann, Matthias; Nawrath, Cornelius; Jetter, Michael; Michler, Peter; Wrachtrup, Jörg; Gerhardt, Ilja

    2016-11-01

    Hybrid quantum systems integrating semiconductor quantum dots (QDs) and atomic vapours become important building blocks for scalable quantum networks due to the complementary strengths of individual parts. QDs provide on-demand single-photon emission with near-unity indistinguishability comprising unprecedented brightness--while atomic vapour systems provide ultra-precise frequency standards and promise long coherence times for the storage of qubits. Spectral filtering is one of the key components for the successful link between QD photons and atoms. Here we present a tailored Faraday anomalous dispersion optical filter based on the caesium-D1 transition for interfacing it with a resonantly pumped QD. The presented Faraday filter enables a narrow-bandwidth (Δω=2π × 1 GHz) simultaneous filtering of both Mollow triplet sidebands. This result opens the way to use QDs as sources of single as well as cascaded photons in photonic quantum networks aligned to the primary frequency standard of the caesium clock transition.

  19. Measurement of the infrared complex Faraday angle in semiconductors and insulators

    CERN Document Server

    Kim, M -H; Acbas, G; Ellis, C T; Cerne, J

    2009-01-01

    We measure the infrared (wavelength 11 - 0.8 microns; energy E = 0.1 - 1.5 eV) Faraday rotation and ellipticity in GaAs, BaF2, LaSrGaO4, LaSrAlO4, and ZnSe. Since these materials are commonly used as substrates and windows in infrared magneto-optical measurements, it is important to measure their Faraday signals for background subtraction. These measurement also provide a rigorous test of the accuracy and sensitivity of our unique magneto-polarimetry system. The light sources used in these measurements consist of gas and semiconductor lasers, which cover 0.1 - 1.3 eV, as well as a custom-modified prism monochromator with a Xe lamp, which allows continuous broadband measurements in the 0.28 - 1.5 eV energy range. The sensitivity of this broad-band system is approximately 10 micro-rad. Our measurements reveal that the Verdet coefficients of these materials are proportional to $1/\\lambda^2$, which is expected when probing with radiation energies below the band gap. Reproducible ellipticity signals are also seen,...

  20. Scientific Verification of Faraday Rotation Modulators: Detection of Diffuse Polarized Galactic Emission

    Science.gov (United States)

    Moyerman, S.; Bierman, E.; Ade, P. A. R.; Aiken, R.; Barkats, D.; Bischoff, C.; Bock, J. J.; Chiang, H. C.; Dowell, C. D.; Duband, L.; Hivon, E. F.; Holzapel, W. L.; Hristov, V. V.; Jones, W. C.; Kaufman, J.; Keating, B. G.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Mason, P. V.; Matsumura, T.; Nguyen, H. T.; Ponthieu, N.; Pryke, C.; Wollack, E.

    2012-01-01

    The design and performance of a wide bandwidth linear polarization-modulator based on the Faraday effect is described. Faraday Rotation Modulators (FRMs) are solid-state polarization switches that are capable of modulation up to approx 10 kHz. Six FRMs were utilized during the 2006 observing season in the Background Imaging of Cosmic Extragalactic Polarization (BICEP) experiment; three FRMs were used at each of BICEP fs 100 and 150 GHz frequency bands. The technology was verified through high signal-to-noise detection of Galactic polarization using two of the six FRMs during four observing runs in 2006. The features exhibit strong agreement with BICEP fs measurements of the Galaxy using non-FRM pixels and with the Galactic polarization models. This marks the first detection of high signal-to-noise mm-wave celestial polarization using fast, active optical modulation. The performance of the FRMs during periods when they were not modulated was also analyzed and compared to results from BICEP fs 43 pixels without FRMs.

  1. Simultaneous Faraday filtering of the Mollow triplet sidebands with the Cs-D1 clock transition.

    Science.gov (United States)

    Portalupi, Simone Luca; Widmann, Matthias; Nawrath, Cornelius; Jetter, Michael; Michler, Peter; Wrachtrup, Jörg; Gerhardt, Ilja

    2016-11-25

    Hybrid quantum systems integrating semiconductor quantum dots (QDs) and atomic vapours become important building blocks for scalable quantum networks due to the complementary strengths of individual parts. QDs provide on-demand single-photon emission with near-unity indistinguishability comprising unprecedented brightness-while atomic vapour systems provide ultra-precise frequency standards and promise long coherence times for the storage of qubits. Spectral filtering is one of the key components for the successful link between QD photons and atoms. Here we present a tailored Faraday anomalous dispersion optical filter based on the caesium-D1 transition for interfacing it with a resonantly pumped QD. The presented Faraday filter enables a narrow-bandwidth (Δω=2π × 1 GHz) simultaneous filtering of both Mollow triplet sidebands. This result opens the way to use QDs as sources of single as well as cascaded photons in photonic quantum networks aligned to the primary frequency standard of the caesium clock transition.

  2. Faraday Rotation Measure Synthesis of intermediate redshift quasars as a probe of intervening matter

    CERN Document Server

    Kim, Kwang Seong; Miniati, Francesco; Bernet, M L; Beck, Rainer; O'Sullivan, S P; Gaensler, B M

    2016-01-01

    There is evidence that magnetized material along the line of sight to distant quasars is detectable in the polarization properties of the background sources, which appear to be correlated with the presence of intervening MgII absorption, which is itself thought to arise in outflowing material from star forming galaxies. In order to investigate this further, we have obtained high spectral resolution polarization measurements, with the VLA and ATCA, of a set of 49 unresolved quasars for which we have high quality optical spectra. These enable us to produce a Faraday Depth spectrum for each source, using Rotation Measure Synthesis. We characterize the complexity of the Faraday Depth spectrum using a number of parameters and show how these are related, or not, to the overall depolarization and to the presence of MgII absorption along the line of sight. Our new independent radio data confirms that interveners are strongly associated with depolarization and also, at lower significance, with the mean Rotation Measur...

  3. World Cup:Brands Gamble Began

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    As I click the first word on board,eight days,17 hours and one minute later,the 2010 FIFA World Cup South AfricaTM would star t its month-long competition.Who would like to be awarded the World Cup Trophy at last has already aroused the enthusiasm of the whole world.Furthermore,the worldwide famous sports brands also have launched their adventure to bet which team they sponsored would be at the top of the competition.One month later,we could know who will win eventually.

  4. Faraday, Dickens and Science Education in Victorian Britain

    Science.gov (United States)

    Melville, Wayne; Allingham, Philip V.

    2011-01-01

    The achievements of Michael Faraday in the fields of electricity and electrochemistry have led some to describe him as the greatest experimental scientist in history. Charles Dickens was the creative genius behind some of the most memorable characters in literature. In this article, we share an historical account of how the collaboration of these…

  5. The correspondence of Michael Faraday, v.2 1832-1840

    CERN Document Server

    James, F

    1993-01-01

    Volume 2 covers the 1830s, a period when Faraday pursued the consequences of his discovery of electromagnetic induction and revised entirely the theories of electrochemistry and the nature of electricity.His correspondents include scientists of the day as well as antiquaries, military men, artists and politicians.

  6. The correspondence of Michael Faraday, v.4 1849-1855

    CERN Document Server

    James, F

    2008-01-01

    This volume includes 70% of previously unpublished letters of Michael Farday spanning half of the 1850s and most of 1860. Topics include Faraday's work on regelation, the transmission of light through gold and his appointment by Emperor Napoleon III to be a Commander of the Legion of Honour.

  7. Correspondence of Michael Faraday, v.5 1855-1860

    CERN Document Server

    Faraday, Michael

    2008-01-01

    This volume includes 70% of previously unpublished letters of Michael Farday spanning half of the 1850s and most of 1860. Topics include Faraday's work on regelation, the transmission of light through gold and his appointment by Emperor Napoleon III to be a Commander of the Legion of Honour.

  8. Assessment of the Usability of the Workbench Faraday Cage Method

    DEFF Research Database (Denmark)

    Sørensen, Morten; Franek, Ondrej; Christensen, Søren K.

    2011-01-01

    The workbench Faraday Cage method (WBFC) is a time efficient module pre-compliance test regarding radiated emission. This work investigates the method’s usability and credibility and concludes that for this particular case the WBFC perform a tolerable compliance test for frequencies below 360 MHz...

  9. Faraday effect revisited: sum rules and convergence issues

    DEFF Research Database (Denmark)

    Cornean, Horia; Nenciu, Gheorghe

    2010-01-01

    This is the third paper of a series revisiting the Faraday effect. The question of the absolute convergence of the sums over the band indices entering the Verdet constant is considered. In general, sum rules and traces per unit volume play an important role in solid-state physics, and they give...

  10. Faraday's Investigation of Electromagnetic Induction. Experiment No. 21.

    Science.gov (United States)

    Devons, Samuel

    This paper focuses on Michael Faraday's experimental research in electricity in the 1830's. Historical notes related to his work are included as well as experiments, his objectives, and illustrations of equipment for the experiments. Examples from his diary are given so that students can attempt to emulate his honest and systematic manner of…

  11. Concluding remarks: Faraday Discussion on chemistry in the urban atmosphere.

    Science.gov (United States)

    Jimenez, Jose L

    2016-07-18

    This article summarises the Concluding remarks from the Faraday Discussion on Chemistry in the Urban Atmosphere. The following themes are addressed: (a) new results that inform our understanding of the evolving sources and composition of the urban atmosphere ("News"); (b) results that identify gaps in our understanding that necessitate further work ("Gaps");

  12. Achieving Giant Magneto-optic Effects with Optical Tamm States in Graphene-based Photonics

    OpenAIRE

    Da, Haixia; Qiu, Cheng-Wei; Bao, Qiaoliang; Teng, Jinghua; Loh, Kian Ping; Garcia-Vidal, Francisco J.

    2013-01-01

    We manipulate optical Tamm states in graphene-based photonics to achieve and steer large magneto-optical effects. Here we report the presence of a giant Faraday rotation via a single graphene layer of atomic thickness while keeping a high transmission. The Faraday rotation is enhanced across the interface between two photonic crystals due to the presence of an interface mode, which presents a strong electromagnetic field confinement at the location of the graphene sheet. Our proposed scheme o...

  13. Football business models: Why did Germany win the World Cup?

    DEFF Research Database (Denmark)

    Cortsen, Kenneth

    2016-01-01

    This article looks into the managerial aspects related to why and how Germany won the 2014 FIFA World Cup.......This article looks into the managerial aspects related to why and how Germany won the 2014 FIFA World Cup....

  14. Green goal: Awareness of the 2010 FIFA World Cup's greening ...

    African Journals Online (AJOL)

    ... Cup's greening programmes and implications for environmental education. ... the Department of Environmental Affairs and Tourism (DEAT) embarked on the ... their perceptions of the environmental impacts of the 2010 FIFA World Cup, ...

  15. Coffee to Go: Woman "Thinks" First Cup in 15 Years

    Science.gov (United States)

    ... turn Javascript on. Feature: NIBIB Robotics Coffee to Go: Woman "Thinks" First Cup in 15 Years Past ... Athlete Stands Again…On His Own! / Coffee to Go: Woman "Thinks" First Cup in 15 Years Spring ...

  16. Fast-response cup anemometer features cosine response

    Science.gov (United States)

    Frenzen, P.

    1968-01-01

    Six-cup, low-inertia anemometer combines high resolution and fast response with a unique ability to sense only the horizontal component of the winds fluctuating rapidly in three dimensions. Cup assemblies are fabricated of expanded polystyrene plastic.

  17. Football business models: Why did Germany win the World Cup?

    DEFF Research Database (Denmark)

    Cortsen, Kenneth

    2014-01-01

    This article looks into the managerial aspects related to why and how Germany won the 2014 FIFA World Cup.......This article looks into the managerial aspects related to why and how Germany won the 2014 FIFA World Cup....

  18. An Updated Review of the Efficacy of Cupping Therapy

    OpenAIRE

    Huijuan Cao; Xun Li; Jianping Liu

    2012-01-01

    BACKGROUND: Since 1950, traditional Chinese medicine (TCM) cupping therapy has been applied as a formal modality in hospitals throughout China and elsewhere in the world. Based on a previous systematic literature review of clinical studies on cupping therapy, this study presents a thorough review of randomized controlled trials (RCTs) to evaluate the therapeutic effect of cupping therapy. METHOD: Six databases were searched for articles published through 2010. RCTs on cupping therapy for vari...

  19. Cup products in Hopf cyclic cohomology with coefficients in contramodules

    CERN Document Server

    Rangipour, Bahram

    2010-01-01

    We use stable anti Yetter-Drinfeld contramodules to improve the cup products in Hopf cyclic cohomology. The improvement fixes the lack of functoriality of the cup products previously defined and show that the cup products are sensitive to the coefficients.

  20. Improved analytical method to study the cup anemometer performance

    Science.gov (United States)

    Pindado, Santiago; Ramos-Cenzano, Alvaro; Cubas, Javier

    2015-10-01

    The cup anemometer rotor aerodynamics is analytically studied based on the aerodynamics of a single cup. The effect of the rotation on the aerodynamic force is included in the analytical model, together with the displacement of the aerodynamic center during one turn of the cup. The model can be fitted to the testing results, indicating the presence of both the aforementioned effects.

  1. Orienteering World Cup hosted by CERN Club

    CERN Multimedia

    Katarina Anthony

    2010-01-01

    Elite runners took to the streets of Geneva for the last leg of the Orienteering World Cup, from 8-10 October. The Geneva finals were hosted by the CERN Orienteering Club and concluded months of competitions held across 5 countries.   Women's World-Cup winner, Simone Niggli (centre).  © Ilknur Colak The final events of the Orienteering World Cup took place in the Old Town of Geneva and Saint-Cergue, with runners following routes prepared by the CERN Orienteering Club. Orienteering is a sport of navigation, using only a compass, map and your sense of direction. The objective is to get to all the points on the map as quickly as possible, choosing your own paths as you run. This was the CERN club’s first successful participation in the World Cup, cementing its reputation as a fixture in the international orienteering world. Orienteering is not your typical Swiss pastime. Developed in Scandinavia, the sport has been gaining popularity internationally. “...

  2. Recycling disposable cups into paper plastic composites.

    Science.gov (United States)

    Mitchell, Jonathan; Vandeperre, Luc; Dvorak, Rob; Kosior, Ed; Tarverdi, Karnik; Cheeseman, Christopher

    2014-11-01

    The majority of disposable cups are made from paper plastic laminates (PPL) which consist of high quality cellulose fibre with a thin internal polyethylene coating. There are limited recycling options for PPLs and this has contributed to disposable cups becoming a high profile, problematic waste. In this work disposable cups have been shredded to form PPL flakes and these have been used to reinforce polypropylene to form novel paper plastic composites (PPCs). The PPL flakes and polypropylene were mixed, extruded, pelletised and injection moulded at low temperatures to prevent degradation of the cellulose fibres. The level of PPL flake addition and the use of a maleated polyolefin coupling agent to enhance interfacial adhesion have been investigated. Samples have been characterised using tensile testing, dynamic mechanical analysis (DMA) and thermogravimetric analysis. Use of a coupling agent allows composites containing 40 wt.% of PPL flakes to increase tensile strength of PP by 50% to 30 MPa. The Young modulus also increases from 1 to 2.5 GPa and the work to fracture increases by a factor of 5. The work demonstrates that PPL disposable cups have potential to be beneficially reused as reinforcement in novel polypropylene composites.

  3. ACCUWIND - Methods for classification of cup anemometers

    Energy Technology Data Exchange (ETDEWEB)

    Dahlberg, J.Aa.; Friis Pedersen, T.; Busche, P.

    2006-05-15

    Errors associated with the measurement of wind speed are the major sources of uncertainties in power performance testing of wind turbines. Field comparisons of well-calibrated anemometers show significant and not acceptable difference. The European CLASSCUP project posed the objectives to quantify the errors associated with the use of cup anemometers, and to develop a classification system for quantification of systematic errors of cup anemometers. This classification system has now been implemented in the IEC 61400-12-1 standard on power performance measurements in annex I and J. The classification of cup anemometers requires general external climatic operational ranges to be applied for the analysis of systematic errors. A Class A category classification is connected to reasonably flat sites, and another Class B category is connected to complex terrain, General classification indices are the result of assessment of systematic deviations. The present report focuses on methods that can be applied for assessment of such systematic deviations. A new alternative method for torque coefficient measurements at inclined flow have been developed, which have then been applied and compared to the existing methods developed in the CLASSCUP project and earlier. A number of approaches including the use of two cup anemometer models, two methods of torque coefficient measurement, two angular response measurements, and inclusion and exclusion of influence of friction have been implemented in the classification process in order to assess the robustness of methods. The results of the analysis are presented as classification indices, which are compared and discussed. (au)

  4. Compact quantum gates for hybrid photon-atom systems assisted by Faraday rotation

    Science.gov (United States)

    Song, Guo-Zhu; Yang, Guo-Jian; Zhang, Mei

    2017-02-01

    We present some compact circuits for a deterministic quantum computing on the hybrid photon-atom systems, including the Fredkin gate and SWAP gate. These gates are constructed by exploiting the optical Faraday rotation induced by an atom trapped in a single-sided optical microcavity. The control qubit of our gates is encoded on the polarization states of the single photon, and the target qubit is encoded on the ground states of an atom confined in an optical microcavity. Since the decoherence of the flying qubit with atmosphere for a long distance is negligible and the stationary qubits are trapped inside single-sided microcavities, our gates are robust. Moreover, ancillary single photon is not needed and only some linear-optical devices are adopted, which makes our protocols efficient and practical. Our schemes need not meet the condition that the transmission for the uncoupled cavity is balanceable with the reflectance for the coupled cavity, which is different from the quantum computation with a double-sided optical microcavity. Our calculations show that the fidelities of the two hybrid quantum gates are high with the available experimental technology.

  5. A Procedure for Classification of Cup-Anemometers

    DEFF Research Database (Denmark)

    Friis Pedersen, Troels; Paulsen, Uwe Schmidt

    1997-01-01

    The paper proposes a classification procedure for cup-anemometers based on similar principles as for power converters. A range of operational parameters are established within which the response of the cup-anemometer is evaluated. The characteristics of real cup-anemometers are fitted...... to a realistic 3D cup-anemometer model. Afterwards, the model is used to calculate the response under the range of operational conditions which are set up for the classification. Responses are compared to the normal linear calibration relationship, derived from Wind tunnel calibrations. Results of the 3D cup-anemometer...

  6. High Spectral Resolution Lidar Based on a Potassium Faraday Dispersive Filter for Daytime Temperature Measurement

    Directory of Open Access Journals (Sweden)

    Abo Makoto

    2016-01-01

    Full Text Available In this paper, a new high-spectral-resolution lidar technique is proposed for measuring the profiles of atmospheric temperature in daytime. Based on the theory of high resolution Rayleigh scattering, the feasibility and advantages of using potassium (K Faraday dispersive optical filters as blocking filters for measuring atmospheric temperature are demonstrated with a numerical simulation. It was found that temperature profiles could be measured within 1K error for the height of 9 km with a 500 m range resolution in 60 min by using laser pulses with 1mJ/pulse and 1 kHz, and a 50 cm diameter telescope. Furthermore, we are developing compact pulsed laser system for temperature lidar transmitter.

  7. Quantum noise for Faraday light–matter interfaces

    DEFF Research Database (Denmark)

    Vasliyev, D.V.; Hammerer, K.; Korolev, N.

    2012-01-01

    In light–matter interfaces based on the Faraday effect, quite a number of quantum information protocols have been successfully demonstrated. In order to further increase the performance and fidelities achieved in these protocols, a deeper understanding of the relevant noise and decoherence proces...... be applied to light–matter interfaces and quantum memories based on different mechanisms.......In light–matter interfaces based on the Faraday effect, quite a number of quantum information protocols have been successfully demonstrated. In order to further increase the performance and fidelities achieved in these protocols, a deeper understanding of the relevant noise and decoherence...... processes needs to be gained. In this paper, we provide for the first time a complete description of the decoherence from spontaneous emission. We derive from first principles the effects of photons being spontaneously emitted into unobserved modes. Our results relate the resulting decay and noise terms...

  8. CRADA Final Report, 2011S003, Faraday Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Faraday Technologies

    2012-12-12

    This Phase I SBIR program addressed the need for an improved manufacturing process for electropolishing niobium RF superconducting cavities for the International Linear Collider (ILC). The ILC is a proposed particle accelerator that will be used to gain a deeper understanding of the forces of energy and matter by colliding beams of electrons and positrons at nearly the speed of light. The energy required for this to happen will be achieved through the use of advanced superconducting technology, specifically ~16,000 RF superconducting cavities operating at near absolute zero. The RF superconductor cavities will be fabricated from highly pure Nb, which has an extremely low surface resistance at 2 Kelvin when compared to other materials. To take full advantage of the superconducting properties of the Nb cavities, the inner surface must be a) polished to a microscale roughness < 0.1 µm with removal of at least 100 µm of material, and b) cleaned to be free of impurities that would degrade performance of the ILC. State-of-the-art polishing uses either chemical polishing or electropolishing, both of which require hydrofluoric acid to achieve breakdown of the strong passive film on the surface. In this Phase I program, Faraday worked with its collaborators at the Thomas Jefferson National Accelerator Facility (JLab) to demonstrate the feasibility of an electropolishing process for pure niobium, utilizing an environmentally benign alternative to chemical or electrochemical polishing electrolytes containing hydrofluoric acid. Faraday utilized a 31 wt% aqueous sulfuric acid solution (devoid of hydrofluoric acid) in conjunction with the FARADAYICSM Process, which uses pulse/pulse reverse fields for electropolishing, to demonstrate the ability to electropolish niobium to the desired surface finish. The anticipated benefits of the FARADAYICSM Electropolishing process will be a simpler, safer, and less expensive method capable of surface finishing high purity niobium cavities

  9. Faraday effect in III-VI layer compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gavaleshko, N.P.; Lyakhovich, A.N.; Vatamanyuk, P.P.; Savchuk, A.I. (Chernovitskij Gosudarstvennyj Univ. (Ukrainian SSR))

    1982-10-01

    The Faraday effect is investigated in fields up to 20 T and at temperatures from 77 to 300 K applied to the layer semiconductors GaS, GaSe, and InSe. As an example applicable to the InSe crystals, it is shown possible to separate the direct and indirect forbidden transitions both contributing to the Faraday rotation (FR). The oscillatory nature of the FR spectrum at lower temperatures is proved to be due to the exciton contribution. This is the original report about the FR observed in the depth of the fundamental absorption of InSe crystals. The linearity of the FR in the magnetic field is shown to hold for all the compounds under consideration up to 20 T. The observed data are analyzed in order to estimate some band and exciton parameters of the III-VI semiconductors.

  10. Resonant microsphere gyroscope based on a double Faraday rotator system.

    Science.gov (United States)

    Xie, Chengfeng; Tang, Jun; Cui, Danfeng; Wu, Dajin; Zhang, Chengfei; Li, Chunming; Zhen, Yongqiu; Xue, Chenyang; Liu, Jun

    2016-10-15

    The resonant microsphere gyroscope is proposed based on a double Faraday rotator system for the resonant microsphere gyroscope (RMSG) that is characterized by low insertion losses and does not destroy the reciprocity of the gyroscope system. Use of the echo suppression structure and the orthogonal polarization method can effectively inhibit both the backscattering noise and the polarization error, and reduce them below the system sensitivity limit. The resonance asymmetry rate dropped from 34.2% to 2.9% after optimization of the backscattering noise and the polarization noise, which greatly improved the bias stability and the scale factor linearity of the proposed system. Additionally, based on the optimum parameters for the double Faraday rotator system, a bias stability of 0.04°/s has been established for an integration time of 10 s in 1000 s in a resonator microsphere gyroscope using a microsphere resonator with a diameter of 1 mm and a Q of 7.2×106.

  11. On Bosonic Magnetic Flux Operator and Bosonic Faraday Operator Formula

    Institute of Scientific and Technical Information of China (English)

    FAN Hong-Yi; WANG Tong-Tong; WANG Ji-Suo

    2007-01-01

    In the literature about mesoscopic Josephson devices the magnetic flux is considered as an operator, the fundamental commutative relation between the magnetic flux operator and the Cooper-pair charge operator is usually preengaged. In this paper we show that such a relation can be deduced from the basic Bose operators' commutative relation through the entangled state representation. The Faraday formula in bosonic form is then equivalent to the second Josephson equation. The current operator equation for LC mesoscopic circuit is also derived.

  12. Faraday resonance in dynamical bar instability of differentially rotating stars

    CERN Document Server

    Saijo, Motoyuki

    2008-01-01

    We investigate the nonlinear behaviour of the dynamically unstable rotating star for the bar mode by three-dimensional hydrodynamics in Newtonian gravity. We find that an oscillation along the rotation axis is induced throughout the growth of the unstable bar mode, and that its characteristic frequency is twice as that of the bar mode, which oscillates mainly along the equatorial plane. A possibility to observe Faraday resonance in gravitational waves is demonstrated and discussed.

  13. Toward instructional design principles: Inducing Faraday's law with contrasting cases

    Science.gov (United States)

    Kuo, Eric; Wieman, Carl E.

    2016-06-01

    Although physics education research (PER) has improved instructional practices, there are not agreed upon principles for designing effective instructional materials. Here, we illustrate how close comparison of instructional materials could support the development of such principles. Specifically, in discussion sections of a large, introductory physics course, a pair of studies compare two instructional strategies for teaching a physics concept: having students (i) explain a set of contrasting cases or (ii) apply and build on previously learned concepts. We compare these strategies for the teaching of Faraday's law, showing that explaining a set of related contrasting cases not only improves student performance on Faraday's law questions over building on a previously learned concept (i.e., Lorentz force), but also prepares students to better learn subsequent topics, such as Lenz's law. These differences persist to the final exam. We argue that early exposure to contrasting cases better focuses student attention on a key feature related to both concepts: change in magnetic flux. Importantly, the benefits of contrasting cases for both learning and enjoyment are enhanced for students who did not first attend a Faraday's law lecture, consistent with previous research suggesting that being told a solution can circumvent the benefits of its discovery. These studies illustrate an experimental approach for understanding how the structure of activities affects learning and performance outcomes, a first step toward design principles for effective instructional materials.

  14. Todd, Faraday, and the electrical basis of brain activity.

    Science.gov (United States)

    Reynolds, Edward H

    2004-09-01

    Robert Bentley Todd (1809-60) was the UK's first eminent neurologist and neuroscientist. An anatomist, physiologist, and clinical scientist with an interest in the nervous system, he was the first to confirm the electrical basis of brain activity in the 1840s. He was influenced by his contemporary, Michael Faraday at the Royal Institution, and by two colleagues at King's College, John Daniell and Charles Wheatstone, who were also working at the cutting edge of electrical science. Todd conceived of nervous polarity (force) generated in nervous centres and compared this with the polar force of voltaic electricity developed in the galvanic battery. He brilliantly foresaw each nerve vesicle (cell) and its related fibres (ie, neuron) as a distinct apparatus for the development and transmission of nervous polarity. Epilepsy was the result of periodic unnatural development of nervous force leading to the "disruptive discharge" described by Faraday. Faraday, who studied animal electricity in the Gymnotus (electric eel), and Todd saw nervous polarity as a higher form of interchangeable energy.

  15. Effects of Faraday Rotation Observed in Filter Magnetograph Data

    Science.gov (United States)

    Hagyard, Mona J.; Adams, Mitzi L.; Smith, J. E.; West, Edward A.

    1999-01-01

    In this paper we analyze the effects of Faraday rotation on the azimuth of the transverse magnetic field from observations taken with the Marshall Space Flight Center's vector magnetograph for a simple sunspot observed on June 9, 1985. Vector magnetograms were obtained over the wavelength interval of 170 mA redward of line center of the Fe I 5250.22 A spectral line to 170 mA to the blue, in steps of 10 mA. These data were analyzed to produce the variation of the azimuth as a function of wavelength at each pixel over the field of vi ew of the sunspot. At selected locations in the sunspot, curves of the observed variation of azimuth with wavelength were compared with model calculations for the amount of Faraday rotation of the azimuth. From these comparisons we derived the amount of rotation as functions of bo th the magnitude and inclination of the sunspot's field and deduced the ranges of these field values for which Faraday rotation presents a significant problem in observations taken near the center of a spectral line.

  16. Wave-particle interaction in the Faraday waves.

    Science.gov (United States)

    Francois, N; Xia, H; Punzmann, H; Shats, M

    2015-10-01

    Wave motion in disordered Faraday waves is analysed in terms of oscillons or quasi-particles. The motion of these oscillons is measured using particle tracking tools and it is compared with the motion of fluid particles on the water surface. Both the real floating particles and the oscillons, representing the collective fluid motion, show Brownian-type dispersion exhibiting ballistic and diffusive mean squared displacement at short and long times, respectively. While the floating particles motion has been previously explained in the context of two-dimensional turbulence driven by Faraday waves, no theoretical description exists for the random walk type motion of oscillons. It is found that the r.m.s velocity ⟨μ̃(osc)⟩(rms) of oscillons is directly related to the turbulent r.m.s. velocity ⟨μ̃⟩(rms) of the fluid particles in a broad range of vertical accelerations. The measured ⟨μ̃(osc)⟩(rms) accurately explains the broadening of the frequency spectra of the surface elevation observed in disordered Faraday waves. These results suggest that 2D turbulence is the driving force behind both the randomization of the oscillons motion and the resulting broadening of the wave frequency spectra. The coupling between wave motion and hydrodynamic turbulence demonstrated here offers new perspectives for predicting complex fluid transport from the knowledge of wave field spectra and vice versa.

  17. Analyzing Extragalactic Magnetic Fields Using Faraday Rotation Measure Synthesis

    Science.gov (United States)

    Pare, Dylan; Wang, Q. Daniel; Kamieneski, Patrick; Sullivan, Kendall

    2017-01-01

    Extragalactic magnetic fields are a poorly understood element of galaxies that are likely to play an important role in galaxy formation and evolution. Until recently, however, there was no way to observe these fields to a high level of detail, making it difficult to map the spatial distribution of these fields to any high degree of accuracy. Fortunately, a new technique known as Faraday Rotation Measure Synthesis allows for a more precise analysis of galactic magnetism. This technique uses the observed Faraday rotation of polarized emission from background sources to map the magnetic field of a foreground galaxy. This Faraday rotation occurs when the polarized emission encounters ionized, magnetized gas within the galaxy, causing the emission to be rotated by an amount proportional the magnetic field subjected to the ionized gas. Working as part of CHANG-ES (Continuum HAlos in Nearby Galaxies - an EVLA Survey), we have applied this technique in order to learn about the distribution of magnetic fields in the disks and halos of edge-on spiral galaxies. We will present maps of the galactic magnetic fields of CHANG-ES galaxies using this technique, indicating the potential of this technique in successfully mapping these distant fields.

  18. Corrosion Behavior of Ceramic Cup of Blast Furnace Hearth by Liquid Iron and Slag

    Science.gov (United States)

    Li, Yanglong; Cheng, Shusen; Wang, Zhifeng

    2016-10-01

    Three kinds of sample bricks of ceramic cups for blast furnace hearth were studied by dynamic corrosion tests based on different corrosion systems, i.e., liquid iron system, liquid slag system and liquid iron-slag system. Considering the influence of temperature and sample rotational speed, the corrosion profiles and mass loss of the samples were analyzed. In addition, the microstructure of the corroded samples was observed by optical microscope (OM) and scanning electron microscope (SEM). It was found that the corrosion profiles could be divided into iron corrosion region, slag corrosion region and iron-slag corrosion region via corrosion degree after iron-slag corrosion experiment. The most serious corrosion occurred in iron-slag corrosion region. This is due to Marangoni effect, which promotes a slag film formed between liquid iron and ceramic cup and results in local corrosion. The corrosion of the samples deepened with increasing temperature of liquid iron and slag from 1,623 K to 1,823 K. The variation of slag composition had greater influence on the erosion degree than that of rotational speed in this experiment. Taking these results into account the ceramic cup composition should be close to slag composition to decrease the chemical reaction. A microporous and strong material should be applied for ceramic cup.

  19. Microstructure and mechanical properties of hypereutectic Al-Si alloy modified with Cu-P

    Institute of Scientific and Technical Information of China (English)

    ZHANG Henghua; DUAN Haiti; SHAO Guangjie; XU Luoping

    2008-01-01

    The microstructure and mechanical properties of Al-14.6Si castings modified by Cu-P master alloy under different conditions were studied with optical microscope (OM) and mechanical testing and simulation (MTS).The results indicate that the Cu-P master alloy possesses not only obvious modification effect,but also longevity effect with more than 8 h on the hypereutectic Al-Si alloy.It is shown from thermal calculation,scanning electron microscope (SEM),and energy dispersive analysis of X-rays (EDAX) that the modification mechanism of Cu-P on primary silicon in the castings is heterogeneous nucleation around AlP particles.The Cu-P master alloy has no or little modifying effect on eutectic silicon,even though it has obvious modification on primary silicon in the castings.This may be because of the fast transformation of eutectic silicon at a very narrow temperature,which will notably weaken the role of AlP particles as heterogeneous nuclei for eutectic silicon.

  20. CUP-syndrome diagnostic procedure scheme.

    Science.gov (United States)

    Pujanek, Zuzanna; Burduk, Paweł K

    2013-01-01

    Patients with CUP-Syndrome represent a small percentage of patients treated by ENT doctor. Often, in spite of the implementation detailed diagnostics, detection of the primary tumor fails. Very important element is to follow the correct sequence of tests and taking into account conditions outside ENT. I our article, we would like to propose a diagnostic scheme including interview with patient, laryngological and imaging tests and multi-disciplinary consulting. We hope that this scheme will facilitate the treatment of patients with CUP-Syndrome and increase the efficiency of detection of primary tumor. Copyright © 2013 Polish Otorhinolaryngology - Head and Neck Surgery Society. Published by Elsevier Urban & Partner Sp. z.o.o. All rights reserved.

  1. Flow distortion on boom mounted cup anemometers

    DEFF Research Database (Denmark)

    Lindelöw, Per Jonas Petter; Friis Pedersen, Troels; Gottschall, Julia

    In this report we investigate on wind direction dependent errors in the measurement of the horizontal wind speed by boom mounted cup anemometers. The boom mounting on the studied lattice tower is performed according to IEC standard design rules, yet, larger deviations than predicted by flow models...... are observed. The errors on the measurements are likely caused by an underestimation of the flow distortions around the tower. In this paper an experimental method for deriving a correction formula and an in-field calibration is suggested. The method is based on measurements with two cup anemometers mounted...... in the measurement of wind turbine power performance, wind resource assessment and for providing purposeful in-field comparisons between different sensors, e.g. lidar anemometers. With the proposed method, direction dependent errors can be extracted and the mast flow distortion effect on the wind measurements...

  2. Analysis of Earing in Deep Drawn Cups

    Science.gov (United States)

    Aretz, Holger; Aegerter, Johannes; Engler, Olaf

    2010-06-01

    The cup-drawing of a strongly anisotropic sheet metal is simulated using a commercial finite element software along with a user material subroutine. In order to accurately describe the plastic anisotropy of the material the well-known recent yield function `Yld2004-18p' is extended. Regarding the experimental characterization of the considered material the occurrence of dynamic strain aging lead to an oscillating signal of the width change of the tensile samples, which prevented a reliable determination of plastic strain ratios (r-values). Thus, an improved measurement concept was developed that leads to a very robust and reproducible determination of r-values. Furthermore, a novel plane-strain tensile test sample is presented which is used for the characterization of the plastic anisotropy in biaxial loading states. A quantitative comparison with measured earing profiles of deep drawn cups illustrates the predictive capabilities of the numerical simulation.

  3. Sampling Bias on Cup Anemometer Mean Winds

    Science.gov (United States)

    Kristensen, L.; Hansen, O. F.; Højstrup, J.

    2003-10-01

    The cup anemometer signal can be sampled in several ways to obtain the mean wind speed. Here we discuss the sampling of series of mean wind speeds from consecutive rotor rotations, followed by unweighted and weighted averaging. It is shown that the unweighted averaging creates a positive bias on the long-term mean wind speed, which is at least one order of magnitude larger than the positive bias from the weighted averaging, also known as the sample-and-hold method. For a homogeneous, neutrally stratified flow the first biases are 1%-2%. For comparison the biases due to fluctuations of the three wind velocity components and due to calibration non-linearity are determined under the same conditions. The largest of these is the v-bias from direction fluctuations. The calculations pertain to the Risø P2546A model cup anemometer.

  4. Reasoning about RoboCup Soccer Narratives

    CERN Document Server

    Hajishirzi, Hannaneh; Mueller, Erik T; Amir, Eyal

    2012-01-01

    This paper presents an approach for learning to translate simple narratives, i.e., texts (sequences of sentences) describing dynamic systems, into coherent sequences of events without the need for labeled training data. Our approach incorporates domain knowledge in the form of preconditions and effects of events, and we show that it outperforms state-of-the-art supervised learning systems on the task of reconstructing RoboCup soccer games from their commentaries.

  5. The Economic Impact of the World Cup

    OpenAIRE

    Stefan Szymanski

    2002-01-01

    The World Cup will be the biggest sporting event of 2002, but the Japanese and Korean governments are also hoping that it will be one of the biggest economic events of the year. Impact studies by respected economic research institutes predict a dramatic boost to GDP in both countries. This paper explains how these forecasts are generated and explains the tendency for such forecasts to be over-optimistic. The paper concludes with some policy recommendations for governments and sporting bodies ...

  6. Management of knee osteoarthritis with cupping therapy

    Directory of Open Access Journals (Sweden)

    Asim Ali Khan

    2013-01-01

    Full Text Available The study aimed to evaluate the effect of cupping therapy at a clinical setting for knee osteoarthritis. A randomized, controlled clinical trial was conducted. Cupping was performed on 0-6 th day; 9-11 th day and 14 th day, i.e., 11 sittings follow-up to determine longer term carryover of treatment effects utilizing both objective and subjective assessment. The assessment was performed before and after treatment spreading over a period of 15 days. The results of this study shows significant and better results in the overall management of knee osteoarthritis, particularly in relieving pain, edema, stiffness and disability. The efficacy of treatment with cupping therapy in relieving signs and symptoms of knee osteoarthritis is comparable to that of acetaminophen 650 mg thrice a day orally, in terms of analgesia, anti-inflammatory and resolution of edema with minimal and temporary side-effects like echymosis and blister formation while as control drug has greater side-effects particularly on upper gastrointestinal tract. It is recommended that further studies are conducted with a larger study samples and of longer duration.

  7. Management of knee osteoarthritis with cupping therapy.

    Science.gov (United States)

    Khan, Asim Ali; Jahangir, Umar; Urooj, Shaista

    2013-10-01

    The study aimed to evaluate the effect of cupping therapy at a clinical setting for knee osteoarthritis. A randomized, controlled clinical trial was conducted. Cupping was performed on 0-6(th) day; 9-11(th) day and 14(th) day, i.e., 11 sittings follow-up to determine longer term carryover of treatment effects utilizing both objective and subjective assessment. The assessment was performed before and after treatment spreading over a period of 15 days. The results of this study shows significant and better results in the overall management of knee osteoarthritis, particularly in relieving pain, edema, stiffness and disability. The efficacy of treatment with cupping therapy in relieving signs and symptoms of knee osteoarthritis is comparable to that of acetaminophen 650 mg thrice a day orally, in terms of analgesia, anti-inflammatory and resolution of edema with minimal and temporary side-effects like echymosis and blister formation while as control drug has greater side-effects particularly on upper gastrointestinal tract. It is recommended that further studies are conducted with a larger study samples and of longer duration.

  8. Compilation of LLNL CUP-2 Data

    Energy Technology Data Exchange (ETDEWEB)

    Eppich, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kips, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lindvall, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-07-31

    The CUP-2 uranium ore concentrate (UOC) standard reference material, a powder, was produced at the Blind River uranium refinery of Eldorado Resources Ltd. in Canada in 1986. This material was produced as part of a joint effort by the Canadian Certified Reference Materials Project and the Canadian Uranium Producers Metallurgical Committee to develop a certified reference material for uranium concentration and the concentration of several impurity constituents. This standard was developed to satisfy the requirements of the UOC mining and milling industry, and was characterized with this purpose in mind. To produce CUP-2, approximately 25 kg of UOC derived from the Blind River uranium refinery was blended, homogenized, and assessed for homogeneity by X-ray fluorescence (XRF) analysis. The homogenized material was then packaged into bottles, containing 50 g of material each, and distributed for analysis to laboratories in 1986. The CUP-2 UOC standard was characterized by an interlaboratory analysis program involving eight member laboratories, six commercial laboratories, and three additional volunteer laboratories. Each laboratory provided five replicate results on up to 17 analytes, including total uranium concentration, and moisture content. The selection of analytical technique was left to each participating laboratory. Uranium was reported on an “as-received” basis; all other analytes (besides moisture content) were reported on a “dry-weight” basis.

  9. Study of the Vertical Magnetic Field in Face-on Galaxies Using Faraday Tomography

    Science.gov (United States)

    Ideguchi, Shinsuke; Tashiro, Yuichi; Akahori, Takuya; Takahashi, Keitaro; Ryu, Dongsu

    2017-07-01

    Faraday tomography allows astronomers to probe the distribution of the magnetic field along the line of sight (LOS), but that can be achieved only after the Faraday spectrum is interpreted. However, the interpretation is not straightforward, mainly because the Faraday spectrum is complicated due to a turbulent magnetic field; it ruins the one-to-one relation between the Faraday depth and the physical depth, and appears as many small-scale features in the Faraday spectrum. In this paper, by employing “simple toy models” for the magnetic field, we describe numerically as well as analytically the characteristic properties of the Faraday spectrum. We show that the Faraday spectrum along “multiple LOSs” can be used to extract the global properties of the magnetic field. Specifically, considering face-on spiral galaxies and modeling turbulent magnetic field as a random field with a single coherence length, we numerically calculate the Faraday spectrum along a number of LOSs and its shape-characterizing parameters, that is, the moments. When multiple LOSs cover a region of ≳(10 coherence length)2, the shape of the Faraday spectrum becomes smooth and the shape-characterizing parameters are well specified. With the Faraday spectrum constructed as a sum of Gaussian functions with different means and variances, we analytically show that the parameters are expressed in terms of the regular and turbulent components of the LOS magnetic field and the coherence length. We also consider the turbulent magnetic field modeled with a power-law spectrum, and study how the magnetic field is revealed in the Faraday spectrum. Our work suggests a way to obtain information on the magnetic field from a Faraday tomography study.

  10. Observation of two-dimensional Faraday waves in extremely shallow depth.

    Science.gov (United States)

    Li, Xiaochen; Yu, Zhengyue; Liao, Shijun

    2015-09-01

    A family of two-dimensional Faraday waves in extremely shallow depth (1 mm to 2 mm) of absolute ethanol are observed experimentally using a Hele-Shaw cell that vibrates vertically. The same phenomena are not observed by means of water, ethanol solution, and silicone oil. These Faraday waves are quite different from the traditional ones. These phenomena are helpful to deepen and enrich our understandings about Faraday waves, and besides provide a challenging problem for computational fluid dynamics.

  11. Novel Implementations of Faraday Rotation Spectroscopy - from In-Situ Radical Detection to Studies of Environmental Nitrogen Cycling

    Science.gov (United States)

    Zhang, Eric; Westberg, Jonas; Wysocki, Gerard

    2016-06-01

    Radical species play an important role in various chemical processes spanning atmospheric chemistry (e.g. ozone formation), bio-medical science, and combustion. These highly reactive chemicals usually occur at very low concentration levels, and are difficult to quantify in experiments1. Generally, laser-based techniques rely on careful selection of the target transition to minimize spectral interference and achieve high selectivity. In case of complex gas mixtures (such as air) a possibility of spectral interference always exists. Since Faraday rotation spectroscopy (FRS) is sensitive only to paramagnetic species (radicals), it can simultaneously provide ultra-high sensitivity and selectivity. In this talk an overview of novel designs of FRS instrumentation as well as applications of FRS sensing will be provided. Examples will be given for FRS systems that routinely operate at the fundamental limits of optical detection, cavity-enhanced FRS detection schemes for sensitivity enhancement towards sub-pptv detection limits2, and high-accuracy FRS spectrometers designed specifically for ratiometry of nitrogen isotopes (14N, 15N)3. Prospects for the FRS technology to monitor important atmospheric molecules such as HOx radicals (atmospheric "cleansing" agents) will be discussed. References: 1. Wennberg et al., "Aircraft-borne, laser-induced fluorescence instrument for the in situ detection of hydroxyl and hydroperoxyl radicals," Rev. Sci. Instrum. 65, 1858-1876 (1994). 2. Westberg et al., "Optical feedback cavity-enhanced Faraday rotation spectroscopy for oxygen detection," in CES2015(Boulder, CO, 2015). 3. Zhang, "Nitric Oxide Isotopic Analyzer Based on a Compact Dual-Modulation Faraday Rotation Spectrometer," Sensors 15, 25992 (2015).

  12. [Progress of researches on the mechanism of cupping therapy].

    Science.gov (United States)

    Cui, Shuai; Cui, Jin

    2012-12-01

    Cupping therapy of Chinese medicine is able to relieve a variety of diseases or clinical conditions, which results from the comprehensive effects of multiple types of stimulation exerted onto the regional acupoint areas. Among the stimuli, the negative pressure from cupping is one of the main factors inducing therapeutic effects. In the present paper, the authors review development of researches on the underlying mechanism of therapeutic effects of cupping-negative pressure from 1) the factor of intra-cup negative pressure; 2) influence of intra-cup negative pressure on cup-blackspot formation; 3) influence of cupping on regional blood vessels and blood flow; 4) effect of cupping on regional ultrastructure of the capillary in the raw-surface tissue; 5) effect of cupping-negative pressure on regional endothelial cells; and 6) biological effects of negative pressure drainage. Generally, cupping induced negative pressure can dilate local blood vessels to improve microcirculation, promote capillary endothelial cells repair, accelerate granulation and angiogenesis, etc., in the regional tissues, normalizing the patients' functional state at last.

  13. Meta-analysis of genome-wide association studies identifies novel loci that influence cupping and the glaucomatous process

    NARCIS (Netherlands)

    Springelkamp, Henriet; Hoehn, Rene; Mishra, Aniket; Hysi, Pirro G.; Khor, Chiea-Chuen; Loomis, Stephanie J.; Bailey, Jessica N. Cooke; Gibson, Jane; Thorleifsson, Gudmar; Janssen, Sarah F.; Luo, Xiaoyan; Ramdas, Wishal D.; Vithana, Eranga; Nongpiur, Monisha E.; Montgomery, GrantW.; Xu, Liang; Mountain, Jenny E.; Gharahkhani, Puya; Lu, Yi; Amin, Najaf; Karssen, Lennart C.; Sim, Kar-Seng; van Leeuwen, Elisabeth M.; Iglesias, Adriana I.; Verhoeven, Virginie J. M.; Hauser, Michael A.; Loon, Seng-Chee; Despriet, Dominiek D. G.; Nag, Abhishek; Venturini, Cristina; Sanfilippo, Paul G.; Schillert, Arne; Kang, Jae H.; Landers, John; Jonasson, Fridbert; Cree, Angela J.; van Koolwijk, Leonieke M. E.; Rivadeneira, Fernando; Souzeau, Emmanuelle; Jonsson, Vesteinn; Menon, Geeta; Weinreb, Robert N.; de Jong, Paulus T. V. M.; Oostra, Ben A.; Uitterlinden, Andre G.; Hofman, Albert; Ennis, Sarah; Thorsteinsdottir, Unnur; Burdon, Kathryn P.; Spector, Timothy D.; Mirshahi, Alireza; Saw, Seang-Mei; Vingerling, Johannes R.; Teo, Yik-Ying; Haines, Jonathan L.; Wolfs, Roger C. W.; Lemij, Hans G.; Tai, E-Shyong; Jansonius, Nomdo M.; Jonas, Jost B.; Cheng, Ching-Yu; Aung, Tin; Viswanathan, Ananth C.; Klaver, Caroline C. W.; Craig, Jamie E.; Macgregor, Stuart; Mackey, David A.; Lotery, Andrew J.; Stefansson, Kari; Bergen, Arthur A. B.; Young, Terri L.; Wiggs, Janey L.; Pfeiffer, Norbert; Wong, Tien-Yin; Pasquale, Louis R.; Hewitt, Alex W.; van Duijn, Cornelia M.; Hammond, Christopher J.

    Glaucoma is characterized by irreversible optic nerve degeneration and is the most frequent cause of irreversible blindness worldwide. Here, the International Glaucoma Genetics Consortium conducts a meta-analysis of genome-wide association studies of vertical cup-disc ratio (VCDR), an important

  14. Meta-analysis of genome-wide association studies identifies novel loci that influence cupping and the glaucomatous process

    NARCIS (Netherlands)

    H. Springelkamp (Henriët); R. Höhn (René); A. Mishra (Aniket); P.G. Hysi (Pirro); C.C. Khor; S.J. Loomis (Stephanie J.); J.N.C. Bailey (Jessica N. Cooke); J. Gibson (Jane); G. Thorleifsson (Gudmar); S.F. Janssen (Sarah); X. Luo (Xiaoyan); W.D. Ramdas (Wishal); E.N. Vithana (Eranga); M.E. Nongpiur (Monisha E.); G.W. Montgomery (Grant); L. Xu (Liang); J.E. Mountain (Jenny E.); P. Gharahkhani (Puya); Y. Lu (Yi); N. Amin (Najaf); L.C. Karssen (Lennart); K.S. Sim; E.M. van Leeuwen (Elisa); A.I. Iglesias González (Adriana); V.J.M. Verhoeven (Virginie); M.A. Hauser (Michael); S.-C. Loon (Seng-Chee); D.D.G. Despriet (Dominique); A. Nag (Abhishek); C. Venturini (Cristina); P.G. Sanfilippo (Paul G.); A. Schillert (Arne); J.H. Kang (Jae H.); J. Landers (John); F. Jonasson (Fridbert); A.J. Cree (Angela); L.M.E. van Koolwijk (Leonieke); F. Rivadeneira Ramirez (Fernando); E. Souzeau (Emmanuelle); V. Jonsson (Vesteinn); G. Menon (Geeta); P. Mitchell (Paul); J.J. Wang (Jie Jin); E. Rochtchina (Elena); J. Attia (John); R. Scott (Rodney); E.G. Holliday (Elizabeth); P.N. Baird (Paul); J. Xie (Jing); M. Inouye (Michael); A.C. Viswanathan (Ananth); X. Sim (Xueling); R.N. Weinreb (Robert N.); P.T.V.M. de Jong (Paulus); B.A. Oostra (Ben); A.G. Uitterlinden (André); A. Hofman (Albert); S. Ennis (Sarah); U. Thorsteinsdottir (Unnur); K.P. Burdon (Kathryn); T.D. Spector (Timothy); A. Mirshahi (Alireza); S-M. Saw (Seang-Mei); J.R. Vingerling (Hans); Y.Y. Teo (Yik Ying); R.C.W. Wolfs (Roger); H.G. Lemij (Hans); E.S. Tai (Shyong); N.M. Jansonius (Nomdo); J.B. Jonas (Jost B.); C-Y. Cheng (Ching-Yu); T. Aung (Tin); C.C.W. Klaver (Caroline); J.E. Craig (Jamie); S. MacGregor (Stuart); D.A. Mackey (David); A.J. Lotery (Andrew); J-A. Zwart (John-Anker); A.A.B. Bergen (Arthur); T.L. Young (Terri); J.L. Wiggs (Janey); A.F.H. Pfeiffer (Andreas); T.Y. Wong (Tien); L.R. Pasquale (Louis); A.W. Hewit (Alex); C.M. van Duijn (Cock); C.J. Hammond (Christopher)

    2014-01-01

    textabstractGlaucoma is characterized by irreversible optic nerve degeneration and is the most frequent cause of irreversible blindness worldwide. Here, the International Glaucoma Genetics Consortium conducts a meta-analysis of genome-wide association studies of vertical cup-disc ratio (VCDR), an

  15. Meta-analysis of genome-wide association studies identifies novel loci that influence cupping and the glaucomatous process

    NARCIS (Netherlands)

    Springelkamp, Henriët; Höhn, René; Mishra, Aniket; Hysi, Pirro G; Khor, Chiea-Chuen; Loomis, Stephanie J; Bailey, Jessica N Cooke; Gibson, Jane; Thorleifsson, Gudmar; Janssen, Sarah F; Luo, Xiaoyan; Ramdas, Wishal D; Vithana, Eranga; Nongpiur, Monisha E; Montgomery, Grant W; Xu, Liang; Mountain, Jenny E; Gharahkhani, Puya; Lu, Yi; Amin, Najaf; Karssen, Lennart C; Sim, Kar-Seng; van Leeuwen, Elisabeth M; Iglesias, Adriana I; Verhoeven, Virginie J M; Hauser, Michael A; Loon, Seng-Chee; Despriet, Dominiek D G; Nag, Abhishek; Venturini, Cristina; Sanfilippo, Paul G; Schillert, Arne; Kang, Jae H; Landers, John; Jonasson, Fridbert; Cree, Angela J; van Koolwijk, Leonieke M E; Rivadeneira, Fernando; Souzeau, Emmanuelle; Jonsson, Vesteinn; Menon, Geeta; Weinreb, Robert N; de Jong, Paulus T V M; Oostra, Ben A; Uitterlinden, André G; Hofman, Albert; Ennis, Sarah; Thorsteinsdottir, Unnur; Burdon, Kathryn P; Spector, Timothy D; Mirshahi, Alireza; Saw, Seang-Mei; Vingerling, Johannes R; Teo, Yik-Ying; Haines, Jonathan L; Wolfs, Roger C W; Lemij, Hans G; Tai, E-Shyong; Jansonius, Nomdo M; Jonas, Jost B; Cheng, Ching-Yu; Aung, Tin; Viswanathan, Ananth C; Klaver, Caroline C W; Craig, Jamie E; Macgregor, Stuart; Mackey, David A; Lotery, Andrew J; Stefansson, Kari; Bergen, Arthur A B; Young, Terri L; Wiggs, Janey L; Pfeiffer, Norbert; Wong, Tien-Yin; Pasquale, Louis R; Hewitt, Alex W; van Duijn, Cornelia M; Hammond, Christopher J

    2014-01-01

    Glaucoma is characterized by irreversible optic nerve degeneration and is the most frequent cause of irreversible blindness worldwide. Here, the International Glaucoma Genetics Consortium conducts a meta-analysis of genome-wide association studies of vertical cup-disc ratio (VCDR), an important

  16. Meta-analysis of genome-wide association studies identifies novel loci that influence cupping and the glaucomatous process

    NARCIS (Netherlands)

    Springelkamp, Henriët; Höhn, René; Mishra, Aniket; Hysi, Pirro G; Khor, Chiea-Chuen; Loomis, Stephanie J; Bailey, Jessica N Cooke; Gibson, Jane; Thorleifsson, Gudmar; Janssen, Sarah F; Luo, Xiaoyan; Ramdas, Wishal D; Vithana, Eranga; Nongpiur, Monisha E; Montgomery, Grant W; Xu, Liang; Mountain, Jenny E; Gharahkhani, Puya; Lu, Yi; Amin, Najaf; Karssen, Lennart C; Sim, Kar-Seng; van Leeuwen, Elisabeth M; Iglesias, Adriana I; Verhoeven, Virginie J M; Hauser, Michael A; Loon, Seng-Chee; Despriet, Dominiek D G; Nag, Abhishek; Venturini, Cristina; Sanfilippo, Paul G; Schillert, Arne; Kang, Jae H; Landers, John; Jonasson, Fridbert; Cree, Angela J; van Koolwijk, Leonieke M E; Rivadeneira, Fernando; Souzeau, Emmanuelle; Jonsson, Vesteinn; Menon, Geeta; Weinreb, Robert N; de Jong, Paulus T V M; Oostra, Ben A; Uitterlinden, André G; Hofman, Albert; Ennis, Sarah; Thorsteinsdottir, Unnur; Burdon, Kathryn P; Spector, Timothy D; Mirshahi, Alireza; Saw, Seang-Mei; Vingerling, Johannes R; Teo, Yik-Ying; Haines, Jonathan L; Wolfs, Roger C W; Lemij, Hans G; Tai, E-Shyong; Jansonius, Nomdo M; Jonas, Jost B; Cheng, Ching-Yu; Aung, Tin; Viswanathan, Ananth C; Klaver, Caroline C W; Craig, Jamie E; Macgregor, Stuart; Mackey, David A; Lotery, Andrew J; Stefansson, Kari; Bergen, Arthur A B; Young, Terri L; Wiggs, Janey L; Pfeiffer, Norbert; Wong, Tien-Yin; Pasquale, Louis R; Hewitt, Alex W; van Duijn, Cornelia M; Hammond, Christopher J

    2014-01-01

    Glaucoma is characterized by irreversible optic nerve degeneration and is the most frequent cause of irreversible blindness worldwide. Here, the International Glaucoma Genetics Consortium conducts a meta-analysis of genome-wide association studies of vertical cup-disc ratio (VCDR), an important dise

  17. Quantized Faraday effect in 3D+1 and 2D+1 systems

    CERN Document Server

    Rodriguez, L Cruz; Rojas, H Perez; Querts, E Rodriguez

    2013-01-01

    We study Faraday rotation in the quantum relativistic limit. Starting from the photon self-energy in the presence of a constant magnetic field the rotation of the polarization vector of a plane electromagnetic wave which travel along the fermion-antifermion gas is studied. The connection between Faraday Effect and Quantum Hall Effect (QHE) is discussed. The Faraday Effect is also investigated for a massless relativistic 2D+1 fermion system which is derived by using the compactification along the dimension parallel to the magnetic field. Faraday angle shows a quantized behavior as Hall conductivity in two and three dimensions.

  18. Generalized Faraday law derived from classical forces in a rotating frame

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Taeseung [Seoul Women' s University, Seoul (Korea, Republic of)

    2010-06-15

    We show that an additional spin-dependent classical force due to the rotation of an electron spin's rest frame is essential to derive a spin-Faraday law that has the same form as the usual Faraday law. We show that the contribution of the additional spin-dependent force to the spin-Faraday law is the same as the time derivative of the spin geometric phase. With this observations, the spin-Faraday law is generalized to include both an Aharonov-Casher (AC) effect and a scalar AC effect in a unified manner.

  19. Ultrafast magnetic vortex core switching driven by the topological inverse Faraday effect.

    Science.gov (United States)

    Taguchi, Katsuhisa; Ohe, Jun-ichiro; Tatara, Gen

    2012-09-21

    We present a theoretical discovery of an unconventional mechanism of inverse Faraday effect which acts selectively on topological magnetic structures. The effect, topological inverse Faraday effect, is induced by the spin Berry's phase of the magnetic structure when a circularly polarized light is applied. Thus a spin-orbit interaction is not necessary unlike that in the conventional inverse Faraday effect. We demonstrate by numerical simulation that topological inverse Faraday effect realizes ultrafast switching of a magnetic vortex within a switching time of 150 ps without magnetic field.

  20. Compilation of LLNL CUP-2 Data

    Energy Technology Data Exchange (ETDEWEB)

    Eppich, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kips, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lindvall, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-07-31

    The CUP-2 uranium ore concentrate (UOC) standard reference material, a powder, was produced at the Blind River uranium refinery of Eldorado Resources Ltd. in Canada in 1986. This material was produced as part of a joint effort by the Canadian Certified Reference Materials Project and the Canadian Uranium Producers Metallurgical Committee to develop a certified reference material for uranium concentration and the concentration of several impurity constituents. This standard was developed to satisfy the requirements of the UOC mining and milling industry, and was characterized with this purpose in mind. To produce CUP-2, approximately 25 kg of UOC derived from the Blind River uranium refinery was blended, homogenized, and assessed for homogeneity by X-ray fluorescence (XRF) analysis. The homogenized material was then packaged into bottles, containing 50 g of material each, and distributed for analysis to laboratories in 1986. The CUP-2 UOC standard was characterized by an interlaboratory analysis program involving eight member laboratories, six commercial laboratories, and three additional volunteer laboratories. Each laboratory provided five replicate results on up to 17 analytes, including total uranium concentration, and moisture content. The selection of analytical technique was left to each participating laboratory. Uranium was reported on an “as-received” basis; all other analytes (besides moisture content) were reported on a “dry-weight” basis. A bottle of 25g of CUP-2 UOC standard as described above was purchased by LLNL and characterized by the LLNL Nuclear Forensics Group. Non-destructive and destructive analytical techniques were applied to the UOC sample. Information obtained from short-term techniques such as photography, gamma spectrometry, and scanning electron microscopy were used to guide the performance of longer-term techniques such as ICP-MS. Some techniques, such as XRF and ICP-MS, provided complementary types of data. The results

  1. Perceptual elements in Penn & Teller's "Cups and Balls" magic trick.

    Science.gov (United States)

    Rieiro, Hector; Martinez-Conde, Susana; Macknik, Stephen L

    2013-01-01

    Magic illusions provide the perceptual and cognitive scientist with a toolbox of experimental manipulations and testable hypotheses about the building blocks of conscious experience. Here we studied several sleight-of-hand manipulations in the performance of the classic "Cups and Balls" magic trick (where balls appear and disappear inside upside-down opaque cups). We examined a version inspired by the entertainment duo Penn & Teller, conducted with three opaque and subsequently with three transparent cups. Magician Teller used his right hand to load (i.e. introduce surreptitiously) a small ball inside each of two upside-down cups, one at a time, while using his left hand to remove a different ball from the upside-down bottom of the cup. The sleight at the third cup involved one of six manipulations: (a) standard maneuver, (b) standard maneuver without a third ball, (c) ball placed on the table, (d) ball lifted, (e) ball dropped to the floor, and (f) ball stuck to the cup. Seven subjects watched the videos of the performances while reporting, via button press, whenever balls were removed from the cups/table (button "1") or placed inside the cups/on the table (button "2"). Subjects' perception was more accurate with transparent than with opaque cups. Perceptual performance was worse for the conditions where the ball was placed on the table, or stuck to the cup, than for the standard maneuver. The condition in which the ball was lifted displaced the subjects' gaze position the most, whereas the condition in which there was no ball caused the smallest gaze displacement. Training improved the subjects' perceptual performance. Occlusion of the magician's face did not affect the subjects' perception, suggesting that gaze misdirection does not play a strong role in the Cups and Balls illusion. Our results have implications for how to optimize the performance of this classic magic trick, and for the types of hand and object motion that maximize magic misdirection.

  2. Projekt managementu sportovní akce OVB Cup Praha 2013

    OpenAIRE

    Fried, Jan

    2013-01-01

    Title: Project of the sport event OVB Cup Praha 2013 management Objectives: The main objective is to create a project of management and marketing of the sport event OVB Cup Praha 2013. Methods: I chose these methods: participative observation, interview with the use of instructions, brainstorming method, competitor's analysis and SWOT analysis. Results: This thesis should result into a project that should enable the complete organization of the sport event OVB Cup Praha 2013. Generally, it wi...

  3. Optimization of the blank holder force in cup drawing

    OpenAIRE

    Gharib, H.; A.S. Wifi,; M. Younan; Nassef, A

    2006-01-01

    Purpose: Develop an optimization strategy for the cup drawing process in order to produce a defect free deepdrawn cup.Design/methodology/approach: An optimization strategy for the blank holder force (BHF) scheme is proposedwhich searches for the BHF scheme that minimizes the maximum punch force and avoids process limits. Thisstrategy is applied to the linearly varying BHF scheme and compared to the constant BHF.Findings: The optimized linear BHF scheme resulted in an improved cup forming when...

  4. Wear numbers for ball cup and journal bearings

    OpenAIRE

    Ligterink, D.J.; Moes, H.

    1980-01-01

    A wear number is defined for ball cup bearings and for journal bearings where the cup and the cylindrical bearing are made of soft material. This dimensionless wear number provides a relation between the following five quantities: the radius of the ball or the length of the journal bearing in millimetres, the wear modulus in newtons per square millimetre, the maximum wear depth rate of the cup or the cylindrical bearing in millimetres per second, the force between the mating surfaces in newto...

  5. Management sportovní akce - Mystic skate cup

    OpenAIRE

    Dražďák, Pavel

    2013-01-01

    Title: Sport event management - Mystic skate cup Objectives: The main objective of this bachelor thesis is to analyze organization of Mystic skate cup. And alternatively suggest possible improvement for upcoming events. Methods: For analyzing whole event I firstly used the descriptive analysis and afterwards I apply the SWOT analysis, for which I gathered materials through personal interrogation and also interview with the director of the cup. Results: The work highlights the strong aspects o...

  6. Aerodynamic Analysis of Cup Anemometers Performance: The Stationary Harmonic Response

    OpenAIRE

    Santiago Pindado; Javier Cubas; Ángel Sanz-Andrés

    2013-01-01

    The effect of cup anemometer shape parameters, such as the cups’ shape, their size, and their center rotation radius, was experimentally analyzed. This analysis was based on both the calibration constants of the transfer function and the most important harmonic term of the rotor’s movement, which due to the cup anemometer design is the third one. This harmonic analysis represents a new approach to study cup anemometer performances. The results clearly showed a good correlation between the ave...

  7. [The manipulation technique and clinical application of kinetic cupping].

    Science.gov (United States)

    Luo, Rong; Liu, Qi; Sun, Dan

    2013-07-01

    The characteristic of kinetic cupping is explained from treatment principles, manipulation and clinical application. The kinetic cupping is a new particular therapy that combines traditional cupping and kinetic therapy. With cups on the patient, limb action like flexion-extension, adduction-abduction and rotation is made to reinforce clinical effects, which has simple and safe manipulation, obvious efficacy and is well accepted by patient. It has more obvious advantage for pain that was caused by large-area soft tissue injury and discomfort where acupuncture is not appropriate.

  8. Aerodynamic analysis of cup anemometers performance: the stationary harmonic response.

    Science.gov (United States)

    Pindado, Santiago; Cubas, Javier; Sanz-Andrés, Angel

    2013-01-01

    The effect of cup anemometer shape parameters, such as the cups' shape, their size, and their center rotation radius, was experimentally analyzed. This analysis was based on both the calibration constants of the transfer function and the most important harmonic term of the rotor's movement, which due to the cup anemometer design is the third one. This harmonic analysis represents a new approach to study cup anemometer performances. The results clearly showed a good correlation between the average rotational speed of the anemometer's rotor and the mentioned third harmonic term of its movement.

  9. Comparative study of optic disc measurement by Copernicus optical coherence tomography and Heidelberg retinal tomography.

    Science.gov (United States)

    Yang, Qing-Song; Yu, Ya-Jie; Li, Shu-Ning; Liu, Juan; Hao, Ying-Juan

    2012-08-01

    Copernicus optical coherence tomography (SOCT) is a new, ultra high-speed and high-resolution instrument available for clinical evaluation of optic nerve. The purpose of the study was to compare the agreements between SOCT and Heidelberg retinal tomography (HRT). A total of 44 healthy normal volunteers were recruited in this study. One eye in each subject was selected randomly. Agreement between SOCT and HRT-3 in measuring optic disc area was assessed using Bland-Altman plots. Relationships between measurements of optic nerve head parameter obtained by SOCT and HRT-3 were assessed by Pearson correlation. There was no significant difference in the average cup area (0.306 vs. 0.355 mm, P = 0.766), cup volume (0.158 vs. 0.130 mm, P = 0.106) and cup/disc ration (0.394 vs. 0.349 mm, P = 0.576) measured by the two instruments. However, other optic disc parameters from SOCT were significantly lower compared with HRT-3. The Bland-Altman plot revealed good agreement of cup area and cup volume measured by SOCT and HRT-3. Bad agreement of disc area, rim area, rim volume and cup/disc ratio were found between SOCT and HRT-3. The highest correlations between the two instruments were observed for cup area (r(2) = 0.783, P = 0.000) and cup/disc ratio (r(2) = 0.669, P = 0.000), whereas the lowest correlation was observed for disc area (r(2) = 0.100, P = 0.037), rim area (r(2) = 0.275, P = 0.000), cup volume (r(2) = 0.005, P = 0.391) and rim volume (r(2) = 0.021, P = 0.346). There were poor agreements between SOCT and HRT-3 for measurement of optic nerve parameters except cup area and cup volume. Measurement results of the two instruments are not interchangeable.

  10. Electron spin dynamics of Ce3 + ions in YAG crystals studied by pulse-EPR and pump-probe Faraday rotation

    Science.gov (United States)

    Azamat, D. V.; Belykh, V. V.; Yakovlev, D. R.; Fobbe, F.; Feng, D. H.; Evers, E.; Jastrabik, L.; Dejneka, A.; Bayer, M.

    2017-08-01

    The spin relaxation dynamics of Ce3 + ions in heavily cerium-doped YAG crystals is studied using pulse-electron paramagnetic resonance and time-resolved pump-probe Faraday rotation. Both techniques address the 4 f ground state, while pump-probe Faraday rotation also provides access to the excited 5 d state. We measure a millisecond spin-lattice relaxation time T1, a microsecond spin coherence time T2, and a ˜10 ns inhomogeneous spin dephasing time T2* for the Ce3 + ground state at low temperatures. The spin-lattice relaxation of Ce3 + ions is due to modified Raman processes involving the optical phonon mode at ˜125 cm-1 . The relaxation at higher temperature goes through a first excited level of the 5/2 2F term at about ℏ ω ≈228 cm-1 . Effects provided by the hyperfine interaction of the Ce3 + with the 27Al nuclei are observed.

  11. Michael Faraday, 30,000 Teenagers and Climate Change

    Science.gov (United States)

    Giles, K. A.; Wingham, D. J.

    2006-12-01

    One of the objectives of IPY is to engage the awareness, interest and understanding of schoolchildren, the general public and decision-makers worldwide in the purpose and value of polar research and monitoring. Between January and March 2006 I co-presented the Faraday Lecture, run by the Institution of Engineering Technology, which aims to interest the public, and young people in particular, in science and engineering. The topic of the lecture this year was climate change and the technologies that have the potential to reduce our carbon dioxide emissions. As a research fellow at the Centre for Polar Observation and Modelling, University College London, I was able to use my knowledge of the polar regions to help explain the fundamentals of human induced climate change, from using ice cores for paleoclimate studies to what would happen if Greenland melted. The lecture was attended by 30,000 people, mainly aged between 14 to 16, at theatres across the UK and Asia, as well as broadcast on the web to North America and Europe. While the lecture was generally well received, it was apparent that there are misconceptions about the roles of scientists and engineers and a limited understanding of the polar regions and why they are important. The Faraday Lecture is a useful example of a large-scale vehicle for public understanding of science, and for assessing what works and what does not work when addressing young audiences. We consider the lessons learnt from the Faraday lectures in terms of bringing the IPY activities to the attention of the next generation of polar scientists using not only lectures, but a also wider variety of multi-media techniques.

  12. New cylindrical gravitational soliton waves and gravitational Faraday rotation

    CERN Document Server

    Tomizawa, Shinya

    2013-01-01

    In terms of gravitational solitons, we study gravitational non-linear effects of gravitational solitary waves such as Faraday rotation. Applying the Pomeransky's procedure for inverse scattering method, which has been recently used for constructing stationary black hole solutions in five dimensions to a cylindrical spacetime in four dimensions, we construct a new cylindrically symmetric soliton solution. This is the first example to be applied to the cylindrically symmetric case. In particular, we clarify the difference from the Tomimatsu's single soliton solution, which was constructed by the Belinsky-Zakharov's procedure.

  13. Faraday effect in magnetic fluids at a frequency 10 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Maiorov, M.M. E-mail: maiorov@tesla.sal.1v

    2002-11-01

    This work presents some results of observed Faraday effect in magnetic fluids in the centimetric region of the electromagnetic spectrum. The effect is observed when a transversal electric wave of mode H{sub 11} propagates in the circular waveguide with a magnetic fluid. The constant magnetic field was applied along the waveguide. Magnetic fluids with different concentrations of magnetite core nanoparticles suspended in tetradecane (C{sub 14}H{sub 30}) are used in the magnetic fields from 0 to 1500 Oe. A 160 deg. rotation of wave polarization is obtained for a 200 mm sample.

  14. Non-destructive Faraday imaging of dynamically controlled ultracold atoms

    DEFF Research Database (Denmark)

    Gajdacz, Miroslav; Pedersen, Poul Lindholm; Mørch, Troels

    2013-01-01

    We describe an easily implementable method for non-destructive measurements of ultracold atomic clouds based on dark field imaging of spatially resolved Faraday rotation. The signal-to-noise ratio is analyzed theoretically and, in the absence of experimental imperfections, the sensitivity limit...... is found to be identical to other conventional dispersive imaging techniques. The dependence on laser detuning, atomic density, and temperature is characterized in a detailed comparison with theory. Due to low destructiveness, spatially resolved images of the same cloud can be acquired up to 2000 times...

  15. Numerical simulation of super-square patterns in Faraday waves

    CERN Document Server

    Kahouadji, L; Tuckerman, L S; Shin, S; Chergui, J; Juric, D

    2015-01-01

    We report the first simulations of the Faraday instability using the full three-dimensional Navier-Stokes equations in domains much larger than the characteristic wavelength of the pattern. We use a massively parallel code based on a hybrid Front-Tracking/Level-set algorithm for Lagrangian tracking of arbitrarily deformable phase interfaces. Simulations performed in rectangular and cylindrical domains yield complex patterns. In particular, a superlattice-like pattern similar to those of [Douady & Fauve, Europhys. Lett. 6, 221-226 (1988); Douady, J. Fluid Mech. 221, 383-409 (1990)] is observed. The pattern consists of the superposition of two square superlattices.

  16. A model for Faraday pilot-waves over variable topography

    Science.gov (United States)

    Faria, Luiz

    2016-11-01

    In 2005 Yves Couder and co-workers discovered that droplets walking on a vibrating bath posses certain features previously thought to be exclusive to quantum systems. These millimetric droplets synchronize with their Faraday wavefield, creating a macroscopic pilot-wave system. In this talk we exploit the fact that the waves generated are nearly monochromatic and propose a hydrodynamic model capable of capturing the interaction between bouncing drops and a variable topography. We show that our model is able to reproduce some important experiments involving the drop-topography interaction, such as non-specular reflection and single-slit diffraction.

  17. A model for Faraday pilot waves over variable topography

    Science.gov (United States)

    Faria, Luiz M.

    2017-01-01

    Couder and Fort discovered that droplets walking on a vibrating bath possess certain features previously thought to be exclusive to quantum systems. These millimetric droplets synchronize with their Faraday wavefield, creating a macroscopic pilot-wave system. In this paper we exploit the fact that the waves generated are nearly monochromatic and propose a hydrodynamic model capable of quantitatively capturing the interaction between bouncing drops and a variable topography. We show that our reduced model is able to reproduce some important experiments involving the drop-topography interaction, such as non-specular reflection and single-slit diffraction.

  18. Preinjector for Linac 1, inside the Faraday cage

    CERN Multimedia

    1974-01-01

    For a description of the Linac 1 preinjector, please see first 7403070X. Here, the view is towards the upper level of the Faraday cage. Far to the right, a technician is peering through the service door. The huge box-shaped cubicle is the electronics platform, at 520 kV potential during operation. The "bull eye" at the left back sits at the top end of the accelerating column (see 7403081X) and houses the ion source with its electronics (see 7403083X). The SAMES generator, providing the 520 kV HV (7403074) sits on the floor and is not visible here.

  19. Representing the Electromagnetic Field: How Maxwell's Mathematics Empowered Faraday's Field Theory

    Science.gov (United States)

    Tweney, Ryan D.

    2011-01-01

    James Clerk Maxwell "translated" Michael Faraday's experimentally-based field theory into the mathematical representation now known as "Maxwell's Equations." Working with a variety of mathematical representations and physical models Maxwell extended the reach of Faraday's theory and brought it into consistency with other…

  20. High-field Faraday rotation in II-VI-based semimagnetic semiconductors

    NARCIS (Netherlands)

    Savchuk, AI; Fediv, [No Value; Nikitin, PI; Perrone, A; Tatzenko, OM; Platonov, VV

    1998-01-01

    The effects of d-d exchange interaction have been studied by measuring high-field Faraday rotation in II-VI-based semimagnetic semiconductors. For Cd1-xMnxTe crystals with x = 0.43 and at room temperature a saturation in magnetic field dependence of the Faraday rotation has been observed. In the cas

  1. A Left-Hand Rule for Faraday's Law

    Science.gov (United States)

    Salu, Yehuda

    2014-01-01

    A left-hand rule for Faraday's law is presented here. This rule provides a simple and quick way of finding directional relationships between variables of Faraday's law without using Lenz's rule.

  2. Wide frequencies range of spin excitations in a rare-earth Bi-doped iron garnet with a giant Faraday rotation

    Science.gov (United States)

    Parchenko, Sergii; Stupakiewicz, Andrzej; Yoshimine, Isao; Satoh, Takuya; Maziewski, Andrzej

    2013-10-01

    Ultrafast magnetization dynamics of a rare-earth Bi-doped garnet were studied using an optical pump-probe technique via the inverse Faraday effect. We observed a wide range of frequency modes of the magnetization precession, covering two orders of magnitude. The excitation efficiency of low-frequency precessions in the GHz range, together with a significant beating effect, strongly depended on the amplitude of the external magnetic field. On the contrary, high-frequency precession was independent of the external magnetic field. The obtained results may be exploited in the development of wide class of microwave and magneto-optical devices.

  3. Site-resolved imaging of single atoms with a Faraday quantum gas microscope

    CERN Document Server

    Yamamoto, Ryuta; Kato, Kohei; Kuno, Takuma; Sakura, Yuto; Takahashi, Yoshiro

    2016-01-01

    We successfully demonstrate a quantum gas microscopy using the Faraday effect which has an inherently non-destructive nature. The observed Faraday rotation angle reaches 3.0(2) degrees for a single atom. We reveal the non-destructive feature of this Faraday imaging method by comparing the detuning dependence of the Faraday signal strength with that of the photon scattering rate. We determine the atom distribution with deconvolution analysis. We also demonstrate the absorption and the dark field Faraday imaging, and reveal the different shapes of the point spread functions for these methods, which are fully explained by theoretical analysis. Our result is an important first step towards an ultimate quantum non-demolition site-resolved imaging and furthermore opens up the possibilities for quantum feedback control of a quantum many-body system with a single-site resolution.

  4. FEA OF RECTANGULAR CUP DEEP DRAWING PROCESS

    Directory of Open Access Journals (Sweden)

    Awad D.S

    2012-08-01

    Full Text Available Deep drawing is a process for shaping flat sheets into cup shaped articles without fracture or excessive localized thinning. The complex deep drawing of thin metallic sheets is widely used during industrial material forming applications. It allows production of thin walled parts with complicated shapes such as automotive panels or structural parts. The process consists of the plastic deformation of an initial at blank subjected to the action of a rigid punch and die while constrained on the periphery by a blank holder. Conventional design processes for sheet metal forming are usually based on a empirical approach. However, due to the requirement of high precision and reliability in shaped parts, these methods are far away from a final and reliable solution. Nowadays, Finite Element Method (FEM is being gradually adopted by industry to envisage the formability properties of sheet metals. The design and control of a deep drawing process depends not only on the work piece material, but also on the condition at the tool work piece interface, the mechanics of plastic deformation and the equipment used. In this paper, rectangular cup component of EDDQ Steel and Mild Steel is simulated using HYPERMESH 11 by varying various process parameters.

  5. Development of an Innovative Medical Cupping Device

    Directory of Open Access Journals (Sweden)

    Feng-Chyi Duh

    2016-10-01

    Full Text Available Temperature increases to influence the organs are often used in Chinese medicine therapy. A heat therapy cup was developed in this study with temperature control, timer, and heat therapy functions. The concept behind these therapeutic aids is traditional Chinese medicine combined with modern technology and the designs include timers and temperature control. The completed prototypes were used for cupping therapy. After testing, it was found that the standard deviation was greater at a lower temperature setting (To while at a higher To the standard deviation was lower. At To of 30, 40, 50, and 60°C, the relative changes in standard deviations were 5.27%, 2.50%, 2.66%, and 0.88%, respectively. The results indicated that the timer and temperature control functioned properly. Therefore, the designed medical aid, which is an important tool in Chinese medicine, can be provided to people of all ages to maintain health, help with rehabilitation, or to boost energy.

  6. Flow distortion on boom mounted cup anemometers

    Energy Technology Data Exchange (ETDEWEB)

    Lindeloew-Marsden, P.; Pedersen, Troels F.; Gottschall, J.; Vesth, A.; Paulsen, R.W.U.; Courtney, M.S.

    2010-08-15

    In this report we investigate on wind direction dependent errors in the measurement of the horizontal wind speed by boom mounted cup anemometers. The boom mounting on the studied lattice tower is performed according to IEC standard design rules, yet, larger deviations than predicted by flow models are observed. The errors on the measurements are likely caused by an underestimation of the flow distortions around the tower. In this paper an experimental method for deriving a correction formula and an in-field calibration is suggested. The method is based on measurements with two cup anemometers mounted with booms at the same height but pointing in 60 deg. different directions. In the examined case of a 1.9 m wide equilateral triangular lattice tower with booms protruding 4.1 m at 80 m height the measurement errors are observed to reach up to +- 2 %. Errors of this magnitude are severely problematic in the measurement of wind turbine power performance, wind resource assessment and for providing purposeful in-field comparisons between different sensors, e.g. lidar anemometers. With the proposed method, direction dependent errors can be extracted and the mast flow distortion effect on the wind measurements corrected to an uncertainty estimated to better than 0.5%. This level of uncertainty is probably acceptable for the above mentioned applications. (author)

  7. Suppression of infrared absorption in nanostructured metals by controlling Faraday inductance and electron path length.

    Science.gov (United States)

    Han, Sang Eon

    2016-02-08

    Nanostructured metals have been intensively studied for optical applications over the past few decades. However, the intrinsic loss of metals has limited the optical performance of the metal nanostructures in diverse applications. In particular, light concentration in metals by surface plasmons or other resonances causes substantial absorption in metals. Here, we avoid plasmonic excitations for low loss and investigate methods to further suppress loss in nanostructured metals. We demonstrate that parasitic absorption in metal nanostructures can be significantly reduced over a broad band by increasing the Faraday inductance and the electron path length. For an example structure, the loss is reduced in comparison to flat films by more than an order of magnitude over most of the very broad spectrum between short and long wavelength infrared. For a photodetector structure, the fraction of absorption in the photoactive material increases by two orders of magnitude and the photoresponsivity increases by 15 times because of the selective suppression of metal absorption. These findings could benefit many metal-based applications that require low loss such as photovoltaics, photoconductive detectors, solar selective surfaces, infrared-transparent defrosting windows, and other metamaterials.

  8. Protection characteristics of a Faraday cage compromised by lightning burnthrough.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin; Bystrom, Edward; Jorgenson, Roy Eberhardt; Montoya, Sandra L.; Merewether, Kimball O.; Coats, Rebecca Sue; Martinez, Leonard E.; Jojola, John M.

    2012-01-01

    A lightning flash consists of multiple, high-amplitude but short duration return strokes. Between the return strokes is a lower amplitude, continuing current which flows for longer duration. If the walls of a Faraday cage are made of thin enough metal, the continuing current can melt a hole through the metal in a process called burnthrough. A subsequent return stroke can couple energy through this newly-formed hole. This LDRD is a study of the protection provided by a Faraday cage when it has been compromised by burnthrough. We initially repeated some previous experiments and expanded on them in terms of scope and diagnostics to form a knowledge baseline of the coupling phenomena. We then used a combination of experiment, analysis and numerical modeling to study four coupling mechanisms: indirect electric field coupling, indirect magnetic field coupling, conduction through plasma and breakdown through the hole. We discovered voltages higher than those encountered in the previous set of experiments (on the order of several hundreds of volts).

  9. Faraday rotation imaging microscope with microsecond pulse magnet

    Energy Technology Data Exchange (ETDEWEB)

    Suwa, Masayori, E-mail: msuwa@chem.sci.osaka-u.ac.jp [Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Tsukahara, Satoshi [Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Watarai, Hitoshi, E-mail: watarai@chem.sci.osaka-u.ac.jp [Institute for NanoScience Design, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)

    2015-11-01

    We have fabricated a high-performance Faraday rotation (FR) imaging microscope that uses a microsecond pulse magnet comprising an insulated gated bipolar transistor and a 2 μF capacitor. Our microscope produced images with greater stability and sensitivity than those of previous microscopes that used millisecond pulse magnet; these improvements are likely due to high repetition rate and negligible Joule heating effects. The mechanical vibrations in the magnet coil caused by the pulsed current were significantly reduced. The present FR microscope constructed an averaged image from 1000 FR images within 10 min under 1.7 T. Applications of the FR microscope to discriminating three benzene derivatives in micro-capillaries and oscillation-free imaging of spherical polystyrene and polymethyl methacrylate microparticles demonstrated its high performance. - Highlights: • A microsecond pulse magnet with high repetition rate of 10 Hz was fabricated. • Faraday rotation (FR) imaging microscope with the μs magnet was constructed. • Benzene derivatives in microcapillaries were distinguished with the FR microscope. • FR images of single polymer microspheres of 20 μm were correctly acquired. • Observed FR angles agreed quantitatively with those expected from Verdet constants.

  10. VLA Measurements of Faraday Rotation through Coronal Mass Ejections

    CERN Document Server

    Kooi, Jason E; Buffo, Jacob J; Spangler, Steven R

    2016-01-01

    Coronal mass ejections (CMEs) are large-scale eruptions of plasma from the Sun that play an important role in space weather. Faraday rotation (FR) is the rotation of the plane of polarization that results when a linearly polarized signal passes through a magnetized plasma such as a CME. FR observations of a source near the Sun can provide information on the plasma structure of a CME shortly after launch. We report on simultaneous white-light and radio observations made of three CMEs in August 2012. We made sensitive Very Large Array (VLA) full-polarization observations using 1 - 2 GHz frequencies of a "constellation" of radio sources through the solar corona at heliocentric distances that ranged from 6 - 15 solar radii. Of the nine sources observed, three were occulted by CMEs: two sources (0842+1835 and 0900+1832) were occulted by a single CME and one source (0843+1547) was occulted by two CMEs. In addition to our radioastronomical observations, which represent one of the first active hunts for CME Faraday r...

  11. Microreactors for Gold Nanoparticles Synthesis: From Faraday to Flow

    Directory of Open Access Journals (Sweden)

    Md. Taifur Rahman

    2014-06-01

    Full Text Available The seminal work of Michael Faraday in 1850s transmuted the “Alchemy of gold” into a fascinating scientific endeavor over the millennia, particularly in the past half century. Gold nanoparticles (GNPs arguably hold the central position of nanosciences due to their intriguing size-and-shape dependent physicochemical properties, non-toxicity, and ease of functionalization and potential for wide range of applications. The core chemistry involved in the syntheses is essentially not very different from what Michael Faraday resorted to: transforming ions into metallic gold using mild reducing agents. However, the process of such reduction and outcome (shapes and sizes are intricately dependent on basic operational parameters such as sequence of addition and efficiency of mixing of the reagents. Hence, irreproducibility in synthesis and maintaining batch-to-batch quality are major obstacles in this seemingly straightforward process, which poses challenges in scaling-up. Microreactors, by the virtue of excellent control over reagent mixing in space and time within narrow channel networks, opened a new horizon of possibilities to tackle such problems to produce GNPs in more reliable, reproducible and scalable ways. In this review, we will delineate the state-of-the-art of GNPs synthesis using microreactors and will discuss in length how such “flask-to-chip” paradigm shift may revolutionize the very concept of nanosyntheses.

  12. Distance constant of the Risø cup anemometer

    DEFF Research Database (Denmark)

    Kristensen, L.; Frost Hansen, O.

    2002-01-01

    The theory for cup-anemometer dynamics is presented in some detail and two methods of obtaining the distance constant lo are discussed. The first method is based on wind tunnel measurements: with a constant wind speed the cup anemometer is released from alocked position of the rotor...

  13. Five Cups: Observation, Experimentation, and Communication in Science.

    Science.gov (United States)

    Bauer, Christopher F.

    2002-01-01

    Describes the five-cups activity in which students explore materials in the cups. Discusses the effects of this activity on students' understanding of the nature of evidence and the quality and evaluation of that evidence. Includes test results during class and overnight. (KHR)

  14. Suction Cup Induced Palatal Fistula: Surgical Closure by Palatal ...

    African Journals Online (AJOL)

    a maxillary complete denture with a suction cup.[2] A suction cup because of its ... lead to the necrosis of the palatal mucosa and the bone leading ... is not being recommended because of its pathological effect on the palatal tissues leading to.

  15. Can a cup anemometer 'underspeed'? A heretical question

    DEFF Research Database (Denmark)

    Kristensen, L.

    2002-01-01

    An analysis of cup-anemometer dynamics has been carried out in order to determine whether the mean-wind velocity can have a negative bias. This would be contrary to the general belief that cup anemometers always overspeed. Compared to prior analyses, the effect of a possible nonlinearity of the c...

  16. A critical comparison of ten disposable cup LCAs

    Energy Technology Data Exchange (ETDEWEB)

    Harst, Eugenie van der, E-mail: eugenie.vanderharst@wur.nl [Environmental Systems Analysis Group, Wageningen University, P.O. Box 47, NL-6700 AA Wageningen (Netherlands); Potting, José, E-mail: jose.potting@wur.nl [Environmental Systems Analysis Group, Wageningen University, P.O. Box 47, NL-6700 AA Wageningen (Netherlands); Environmental Strategies Research (fms), KTH Royal Institute of Technology, SE-110 44 Stockholm (Sweden)

    2013-11-15

    Disposable cups can be made from conventional petro-plastics, bioplastics, or paperboard (coated with petro-plastics or bioplastics). This study compared ten life cycle assessment (LCA) studies of disposable cups with the aim to evaluate the robustness of their results. The selected studies have only one impact category in common, namely climate change with global warming potential (GWP) as its category indicator. Quantitative GWP results of the studies were closer examined. GWPs within and across each study show none of the cup materials to be consistently better than the others. Comparison of the absolute GWPs (after correction for the cup volume) also shows no consistent better or worse cup material. An evaluation of the methodological choices and the data sets used in the studies revealed their influence on the GWP. The differences in GWP can be attributed to a multitude of factors, i.e., cup material and weight, production processes, waste processes, allocation options, and data used. These factors basically represent different types of uncertainty. Sensitivity and scenario analyses provided only the influence of one factor at once. A systematic and simultaneous use of sensitivity and scenario analyses could, in a next research, result in more robust outcomes. -- Highlights: • Conflicting results from life cycle assessment (LCA) on disposable cups • GWP results of LCAs did not point to a best or worst cup material. • Differences in GWP results are due to methodological choices and data sets used. • Standardized LCA: transparency of LCA studies, but still different in approaches.

  17. Frictional torque numbers for ball cup and journal bearings

    OpenAIRE

    Ligterink, D.J.

    1982-01-01

    Plastic bearing material wears in ball cup and journal bearings. Contact areas in the ball cup and the journal bearing increase. The frictional torque needed to rotate the ball or journal also increases. When the coefficient of friction is assumed to be constant during wearing out, the frictional torque increases to a maximum of 1.273 times the frictional torque at zero wear.

  18. Wear numbers for ball cup and journal bearings

    NARCIS (Netherlands)

    Ligterink, D.J.; Moes, H.

    1980-01-01

    A wear number is defined for ball cup bearings and for journal bearings where the cup and the cylindrical bearing are made of soft material. This dimensionless wear number provides a relation between the following five quantities: the radius of the ball or the length of the journal bearing in millim

  19. Frictional torque numbers for ball cup and journal bearings

    NARCIS (Netherlands)

    Ligterink, D.J.

    1982-01-01

    Plastic bearing material wears in ball cup and journal bearings. Contact areas in the ball cup and the journal bearing increase. The frictional torque needed to rotate the ball or journal also increases. When the coefficient of friction is assumed to be constant during wearing out, the frictional t

  20. A critical comparison of ten disposable cup LCAs

    NARCIS (Netherlands)

    Harst, van der E.J.M.; Potting, J.

    2013-01-01

    Disposable cups can be made from conventional petro-plastics, bioplastics, or paperboard (coated with petro-plastics or bioplastics). This study compared ten life cycle assessment (LCA) studies of disposable cups with the aim to evaluate the robustness of their results. The selected studies have

  1. Meta-analysis of genome-wide association studies identifies novel loci that influence cupping and the glaucomatous process.

    Science.gov (United States)

    Springelkamp, Henriët; Höhn, René; Mishra, Aniket; Hysi, Pirro G; Khor, Chiea-Chuen; Loomis, Stephanie J; Bailey, Jessica N Cooke; Gibson, Jane; Thorleifsson, Gudmar; Janssen, Sarah F; Luo, Xiaoyan; Ramdas, Wishal D; Vithana, Eranga; Nongpiur, Monisha E; Montgomery, Grant W; Xu, Liang; Mountain, Jenny E; Gharahkhani, Puya; Lu, Yi; Amin, Najaf; Karssen, Lennart C; Sim, Kar-Seng; van Leeuwen, Elisabeth M; Iglesias, Adriana I; Verhoeven, Virginie J M; Hauser, Michael A; Loon, Seng-Chee; Despriet, Dominiek D G; Nag, Abhishek; Venturini, Cristina; Sanfilippo, Paul G; Schillert, Arne; Kang, Jae H; Landers, John; Jonasson, Fridbert; Cree, Angela J; van Koolwijk, Leonieke M E; Rivadeneira, Fernando; Souzeau, Emmanuelle; Jonsson, Vesteinn; Menon, Geeta; Weinreb, Robert N; de Jong, Paulus T V M; Oostra, Ben A; Uitterlinden, André G; Hofman, Albert; Ennis, Sarah; Thorsteinsdottir, Unnur; Burdon, Kathryn P; Spector, Timothy D; Mirshahi, Alireza; Saw, Seang-Mei; Vingerling, Johannes R; Teo, Yik-Ying; Haines, Jonathan L; Wolfs, Roger C W; Lemij, Hans G; Tai, E-Shyong; Jansonius, Nomdo M; Jonas, Jost B; Cheng, Ching-Yu; Aung, Tin; Viswanathan, Ananth C; Klaver, Caroline C W; Craig, Jamie E; Macgregor, Stuart; Mackey, David A; Lotery, Andrew J; Stefansson, Kari; Bergen, Arthur A B; Young, Terri L; Wiggs, Janey L; Pfeiffer, Norbert; Wong, Tien-Yin; Pasquale, Louis R; Hewitt, Alex W; van Duijn, Cornelia M; Hammond, Christopher J

    2014-09-22

    Glaucoma is characterized by irreversible optic nerve degeneration and is the most frequent cause of irreversible blindness worldwide. Here, the International Glaucoma Genetics Consortium conducts a meta-analysis of genome-wide association studies of vertical cup-disc ratio (VCDR), an important disease-related optic nerve parameter. In 21,094 individuals of European ancestry and 6,784 individuals of Asian ancestry, we identify 10 new loci associated with variation in VCDR. In a separate risk-score analysis of five case-control studies, Caucasians in the highest quintile have a 2.5-fold increased risk of primary open-angle glaucoma as compared with those in the lowest quintile. This study has more than doubled the known loci associated with optic disc cupping and will allow greater understanding of mechanisms involved in this common blinding condition.

  2. P,T-odd Faraday effect as a tool for observation of CP violation in Standard Model

    CERN Document Server

    Chubukov, D V

    2016-01-01

    It is proposed to employ the P,T-odd Faraday effect, i.e. rotation of the polarization plane of the light propagating through a medium in presence of the electric field, as a tool for observation of P,T-odd effects caused by CP violation within the Standard Model. For this purpose the vapors of heavy atoms like Tl, Pb, Bi are most suitable. Estimates within the Standard Model show: provided that applied field is about 10^5 V/cm and the optical length can be as large as 70000 km, the rotation angle may reach the value corresponding to the recently observable values (10^{-9} rad). These estimates demonstrate that the P,T-odd Faraday effect observations may effectively compete with the recent measurements of the electron spin rotation in an external electric field, performed with diatomic molecules. These measurements exclude the P,T-odd effects at the level 9 orders of magnitude higher than the predictions of the Standard Model.

  3. An orthogonal return method for linearly polarized beam based on the Faraday effect and its application in interferometer.

    Science.gov (United States)

    Chen, Benyong; Zhang, Enzheng; Yan, Liping; Liu, Yanna

    2014-10-01

    Correct return of the measuring beam is essential for laser interferometers to carry out measurement. In the actual situation, because the measured object inevitably rotates or laterally moves, not only the measurement accuracy will decrease, or even the measurement will be impossibly performed. To solve this problem, a novel orthogonal return method for linearly polarized beam based on the Faraday effect is presented. The orthogonal return of incident linearly polarized beam is realized by using a Faraday rotator with the rotational angle of 45°. The optical configuration of the method is designed and analyzed in detail. To verify its practicability in polarization interferometry, a laser heterodyne interferometer based on this method was constructed and precision displacement measurement experiments were performed. These results show that the advantage of the method is that the correct return of the incident measuring beam is ensured when large lateral displacement or angular rotation of the measured object occurs and then the implementation of interferometric measurement can be ensured.

  4. Study of fiber-optic current sensing based on degree of polarization measurement

    Institute of Scientific and Technical Information of China (English)

    Feng Liu; Qing Ye; Jianxin Geng; Ronghui Qu; Zujie Fang

    2007-01-01

    A novel fiber-optic current sensing scheme is proposed by converting the Faraday rotation to the optical signal's degree of polarization (DOP) change. In this scheme, the lightwave passes through a fiber resonant cavity multiply and experiences Faraday rotation simultaneously. Its main merit is immunity from the environment disturbance to the fiber used in ordinary Faraday rotation sensor. Brief theoretical analysis and simulation are given to show its basic characteristics. Experimental results are demonstrated and the feasibility of the proposed method is also shown.

  5. Learning RoboCup-Keepaway with Kernels

    CERN Document Server

    Jung, Tobias

    2012-01-01

    We apply kernel-based methods to solve the difficult reinforcement learning problem of 3vs2 keepaway in RoboCup simulated soccer. Key challenges in keepaway are the high-dimensionality of the state space (rendering conventional discretization-based function approximation like tilecoding infeasible), the stochasticity due to noise and multiple learning agents needing to cooperate (meaning that the exact dynamics of the environment are unknown) and real-time learning (meaning that an efficient online implementation is required). We employ the general framework of approximate policy iteration with least-squares-based policy evaluation. As underlying function approximator we consider the family of regularization networks with subset of regressors approximation. The core of our proposed solution is an efficient recursive implementation with automatic supervised selection of relevant basis functions. Simulation results indicate that the behavior learned through our approach clearly outperforms the best results obta...

  6. Transient Radiation Effects in Optical Materials

    Science.gov (United States)

    1975-04-29

    Steering System 23 2.4 DK-1A 23 2.5 Dosimetry ., 23 2.5.1 Faraday Cup 27 2.5.2 Cobalt -Glass Dosimetry 27 2.5.3 Stopping Block 27 3...and sample holders The mirror was 108 mm in diameter with a radius of curvature of 46 cm. The aluminized reflecting surface was overcoated with...of fluence (e/cm ) and ionizing dose (rads) was accomplished by means of cobalt -glass dosimeters. 23 111’ mvtmmati»tmnm0mi wi *< -, * 100 2600

  7. Point-localized displacement measurement of the Faraday surface on a fluid

    Science.gov (United States)

    Cabeza, C.; Gibiat, V.; Negreira, C.

    2002-10-01

    It has been well known for a long time that dynamic processes are generated by Faraday instability. However, only qualitative experimental results have been obtained in this regard. In this work, we report an original method designed to study and reconstruct the moving surface in Faraday experiments. The technique developed is accurate and a quantitative measurement of the surface displacement is achievable. Two important results have been obtained with this set-up: the numerical reconstruction of the patterns appearing on the surface because of the Faraday instability process and the dynamical evolution to chaos of a localized point of the surface.

  8. High-Field Faraday Effect of Tb-Doped Glass Above Paramagnetic Saturation

    Science.gov (United States)

    Chiba, Yoshiaki; Hori, Hidenobu; Yonenobu, Kenji; Yamagishi, Akio; Date, Muneyuki

    1987-08-01

    High-field Faraday effect is investigated in Tb-doped glass under a pulsed high magnetic field up to 40 tesla(T). The nonlinear Faraday effect due to saturation of the paramagnetic moment appears below about 20 T at 4.2 K. A considerably large Faraday rotation with the Verdet constant of -45.0 rad. T-1 m-1 is found above the paramagnetic saturation field, and this is explained by the field-induced level mixing in the multiplet levels.

  9. Enhanced Transmission and Giant Faraday Effect in Magnetic Metal-Dielectric Photonic Structures

    CERN Document Server

    Smith, Kyle; Bodyfelt, Joshua D; Vitebskiy, Ilya; Chabanov, Andrey A

    2012-01-01

    Due to their large electric conductivity, stand-alone metallic films are highly reflective at microwave frequencies. For this reason, it is nearly impossible to observe Faraday rotation in ferromagnetic metal layers, even in films just tens of nanometers thick. Here, we show using numerical simulations that a stack of cobalt nano-layers interlaced between dielectric layers can become highly transmissive and display a large Faraday rotation in a finite frequency band. A 45-degree Faraday rotation can be achieved with metallic ferromagnetic layers as thin as tens of nanometers.

  10. Inverse energy cascade and emergence of large coherent vortices in turbulence driven by Faraday waves.

    Science.gov (United States)

    Francois, N; Xia, H; Punzmann, H; Shats, M

    2013-05-10

    We report the generation of large coherent vortices via inverse energy cascade in Faraday wave driven turbulence. The motion of floaters in the Faraday waves is three dimensional, but its horizontal velocity fluctuations show unexpected similarity with two-dimensional turbulence. The inverse cascade is detected by measuring frequency spectra of the Lagrangian velocity, and it is confirmed by computing the third moment of the horizontal velocity fluctuations. This is observed in deep water in a broad range of wavelengths and vertical accelerations. The results broaden the scope of recent findings on Faraday waves in thin layers [A. von Kameke et al., Phys. Rev. Lett. 107, 074502 (2011)].

  11. Electrical control of Faraday rotation at a liquid-liquid interface.

    Science.gov (United States)

    Marinescu, Monica; Kornyshev, Alexei A; Flatté, Michael E

    2015-01-01

    A theory is developed for the Faraday rotation of light from a monolayer of charged magnetic nanoparticles at an electrified liquid-liquid interface. The polarization fields of neighboring nanoparticles enhance the Faraday rotation. At such interfaces, and for realistic sizes and charges of nanoparticles, their adsorption-desorption can be controlled with a voltage variationFaraday rotation. A calculation based on the Maxwell-Garnett theory predicts that the corresponding redistribution of 40 nm nanoparticles of yttrium iron garnet can switch a cavity with a quality factor larger than 10(4) for light of wavelength 500 nm at normal incidence.

  12. Dynamics of the Faraday Instability in a Small Cylinder

    CERN Document Server

    Batson, William; Narayanan, Ranga

    2013-01-01

    Vertical oscillation of a fluid interface above a critical amplitude excites the Faraday instability, typically manifesting itself as a standing wave pattern. Fundamentally, the phenomenon is an example of parametric resonance. At high frequencies, the wavelength is small and the pattern selection process is highly nonlinear. We excite the instability with low frequencies, where the wavelength is large, and the form is highly influenced by the container geometry. In this regime, the cell modes are easily excited on an individual basis and the observed waves resemble the forms predicted from linear theory. In our video we highlight basic spatial and temporal dynamics of this regime. This fluid dynamics video is submitted to the APS DFD Gallery of Fluid Motion 2013, part of the 66th Annual Meeting of the American Physical Societys Division of Fluid Dynamics (24-26 November, Pittsburgh, PA, USA).

  13. Can weakly nonlinear theory explain Faraday wave patterns near onset?

    CERN Document Server

    Skeldon, A C

    2015-01-01

    The Faraday problem is an important pattern-forming system that provides some middle ground between systems where the initial instability involves just a single mode and in which complexity then results from mode interactions or secondary bifurcations, and cases where a system is highly turbulent and many spatial and temporal modes are excited. It has been a rich source of novel patterns and of theoretical work aimed at understanding how and why such patterns occur. Yet it is particularly challenging to tie theory to experiment: the experiments are difficult to perform; the parameter regime of interest (large box, moderate viscosity) along with the technical difficulties of solving the free boundary Navier--Stokes equations make numerical solution of the problem hard; and the fact that the instabilities result in an entire circle of unstable wavevectors presents considerable theoretical difficulties. In principle, weakly nonlinear theory should be able to predict which patterns are stable near pattern onset. ...

  14. Using Faraday Rotation to Probe MHD Instabilities in Intracluster Media

    CERN Document Server

    Bogdanovic, Tamara; Massey, Richard

    2010-01-01

    It has recently been suggested that conduction-driven magnetohydrodynamic (MHD) instabilities may operate at all radii within an intracluster medium (ICM), and profoundly affect the structure of a cluster's magnetic field. Where MHD instabilities dominate the dynamics of an ICM, they will re-orient magnetic field lines perpendicular to the temperature gradient inside a cooling core, or parallel to the temperature gradient outside it. This characteristic structure of magnetic field could be probed by measurements of polarized radio emission from background sources. Motivated by this possibility we have constructed 3-d models of a magnetized cooling core cluster and calculated Faraday rotation measure (RM) maps in the plane of the sky under realistic observing conditions. We compare a scenario in which magnetic field geometry is characterized by conduction driven MHD instabilities to that where it is determined by the turbulent motions. We find that future high-sensitivity spectro-polarimetric measurements of R...

  15. Faraday Instability in a Surface-Frozen Liquid

    CERN Document Server

    Huber, P; Embs, J; Wagner, C; Deutsch, M; Kumar, S; Huber, Patrick; Soprunyuk, Viktor; Embs, Jan; Wagner, Christian; Deutsch, Moshe; Kumar, Satish

    2005-01-01

    Faraday surface instability measurements of the critical acceleration, a_c, and wavenumber, k_c, for standing surface waves on a tetracosanol (C_24H_50) melt exhibit abrupt changes at T_s=54degC above the bulk freezing temperature. The measured variations of a_c and k_c vs. temperature and driving frequency are accounted for quantitatively by a hydrodynamic model, revealing a change from a free-slip surface flow, generic for a free liquid surface (T>T_s), to a surface-pinned, no-slip flow, characteristic of a flow near a wetted solid wall (T < T_s). The change at T_s is traced to the onset of surface freezing, where the steep velocity gradient in the surface-pinned flow significantly increases the viscous dissipation near the surface.

  16. Pseudo Magnetic Faraday and Quantum Hall Effect In Oscillating Graphene

    Science.gov (United States)

    Bhagat, Anita; Mullen, Kieran

    When a graphene layer is stressed, the strain changes the phase between sites in a tight binding model of the system. This phase can be viewed as a pseudo-magnetic vector potential. The corresponding pseudo-magnetic field has been experimentally verified in static cases. We examine the case of oscillating graphene ribbons and explore two new effects. The first is to investigate an oscillating pseudo-magnetic field that produces a quantum Hall effect: we calculate the I-V characteristic of an oscillating graphene nanoribbon as a function of frequency, and amplitude in both the oscillations and the applied driving voltage. Second, the time dependent pseudo-magnetic field should produce a pseudo-Faraday effect driving electrons in different valleys in opposite directions. In both cases, we make explicit calculations for experiment. This project was supported in part by the US National Science Foundation under Grant DMR-1310407.

  17. Numerical simulation of supersquare patterns in Faraday waves

    Science.gov (United States)

    Kahouadji, L.; Périnet, N.; Tuckerman, L. S.; Shin, S.; Chergui, J.; Juric, D.

    2015-06-01

    We report the first simulations of the Faraday instability using the full three-dimensional Navier-Stokes equations in domains much larger than the characteristic wavelength of the pattern. We use a massively parallel code based on a hybrid Front-Tracking/Level-set algorithm for Lagrangian tracking of arbitrarily deformable phase interfaces. Simulations performed in rectangular and cylindrical domains yield complex patterns. In particular, a superlattice-like pattern similar to those of [Douady & Fauve, Europhys. Lett. 6, 221-226 (1988); Douady, J. Fluid Mech. 221, 383-409 (1990)] is observed. The pattern consists of the superposition of two square superlattices. We conjecture that such patterns are widespread if the square container is large compared to the critical wavelength. In the cylinder, pentagonal cells near the outer wall allow a square-wave pattern to be accommodated in the center.

  18. Importance of nuclear medicine diagnostics in CUP syndrome; Stellenwert der nuklearmedizinischen Diagnostik bei CUP-Syndrom

    Energy Technology Data Exchange (ETDEWEB)

    Winter, M.C.; Haberkorn, U.; Kratochwil, C. [Universitaetsklinikum Heidelberg, Abteilung fuer Nuklearmedizin, Heidelberg (Germany)

    2014-02-15

    The diagnostic work-up in patients with carcinoma of unknown primary (CUP) syndrome is extensive, highly time-consuming and cost-intensive and ultimately often fails to detect a primary site. In this context chest X-ray and computed tomography (CT) have been used as standard imaging modalities in CUP syndrome. Since the introduction of positron emission tomography (PET) evaluation of tumor vitality has become possible. Furthermore, PET-CT hybrid scanners allow the combination of functional and morphological imaging. Several meta-analyses have reported an additional overall detection rate between 24.5 % and 44 % by either PET or PET-CT. Metastatic localization (cervical versus extracervical) did not influence the performance. The sensitivity was usually high (> 80 %) but specificity was moderate ranging from 68 % to 88 % at best. If mentioned, the results obtained by fluorodeoxyglucose (FDG)-PET significantly changed the clinical management in approximately one third of the patients studied. In a direct comparison with PET alone, PET-CT did not depict significantly more primary tumors but was able to reduce false positive findings. To determine the real additional value of PET-CT in the diagnosis of CUP syndrome large prospective studies with more uniform inclusion criteria are needed. Despite the capabilities of FDG-PET-CT there is as yet no evidence that a potentially improved diagnostic algorithm is translated into a better patient outcome. Nevertheless, FDG-PET-CT should be performed in all CUP patients where conventional imaging failed to detect a primary site or the results are equivocal. In CUP patients with cervical lymph node metastases PET-CT should be carried out prior to panendoscopy to reduce the number of false negative biopsies. (orig.) [German] Die Diagnostik bei Carcinoma-of-unkown-primary(CUP)-Patienten ist meist umfangreich, sowohl sehr zeit- als auch kostenintensiv und verlaeuft dennoch haeufig frustran. Roentgenaufnahmen des Thorax und die

  19. Evaluation of the Optic Nerve Head in Glaucoma.

    Science.gov (United States)

    Gandhi, Monica; Dubey, Suneeta

    2013-01-01

    Glaucoma is an optic neuropathy leading to changes in the intrapaillary and parapaillary regions of the optic disk. Despite technological advances, clinical identification of optic nerve head characteristics remains the first step in diagnosis. Careful examination of the disk parameters including size, shape, neuroretinal rim shape and pallor; size of the optic cup in relation to the area of the disk; configuration and depth of the optic cup; ratios of cup-to-disk diameter and cup-to-disk area; presence and location of splinter-shaped hemorrhages; occurrence, size, configuration, and location of parapapillary chorioretinal atrophy; and visibility of the retinal nerve fiber layer (RNFL) is important to differentiate between the glaucomatous and nonglaucomatous optic neuropathy. How to cite this article: Gandhi M, Dubey S. Evaluation of the Optic Nerve Head in Glaucoma. J Current Glau Prac 2013;7(3):106-114.

  20. Cup anemometer calibration: effect of flow velocity distribution

    Science.gov (United States)

    Piccato, A.; Spazzini, P. G.; Malvano, R.

    2011-10-01

    The effects of different working conditions and specifically of different velocity profiles on the output of a commercial cup anemometer were analysed experimentally. A simple mathematical model is also presented and provides results in line with the experiments. Results show that a cup anemometer with certain geometrical features can be calibrated through a rotating drag rig by correcting for the bias on the instrument output. The increase in uncertainty caused by this systematic correction was evaluated and applied to the results. The correction was validated by checking the compatibility of calibrations of a cup anemometer at the rotating rig and in a wind tunnel.

  1. Aerodynamic Analysis of Cup Anemometers Performance: The Stationary Harmonic Response

    Directory of Open Access Journals (Sweden)

    Santiago Pindado

    2013-01-01

    Full Text Available The effect of cup anemometer shape parameters, such as the cups’ shape, their size, and their center rotation radius, was experimentally analyzed. This analysis was based on both the calibration constants of the transfer function and the most important harmonic term of the rotor’s movement, which due to the cup anemometer design is the third one. This harmonic analysis represents a new approach to study cup anemometer performances. The results clearly showed a good correlation between the average rotational speed of the anemometer’s rotor and the mentioned third harmonic term of its movement.

  2. Machine milking: experimental observations on the life of teat-cup liners.

    Science.gov (United States)

    Ruffo, G; Sangiorgi, F

    1976-01-01

    The useful life of neoprene teat-cup liners used in milking machines was determined by physico-mechanical, optical and microbiological studies. The various tests showed that after more than 1,000 hrs' use, that is the milking time plus disinfection time, there were physico-mechanical and biological changes that could have an adverse effect on the health of the udder as a result of a loss of elasticity and a dissemination of mastitis-producing microorganisms (S. agalactiae, S. aureus) which settle in cracks in the surface of the rubber.

  3. The application of compressive sampling to radio astronomy II: Faraday rotation measure synthesis

    CERN Document Server

    Li, Feng; Cornwell, Tim J; de Hoog, Frank

    2011-01-01

    Faraday rotation measure (RM) synthesis is an important tool to study and analyze galactic and extra-galactic magnetic fields. Since there is a Fourier relation between the Faraday dispersion function and the polarized radio emission, full reconstruction of the dispersion function requires knowledge of the polarized radio emission at both positive and negative square wavelengths $\\lambda^2$. However, one can only make observations for $\\lambda^2 > 0$. Furthermore observations are possible only for a limited range of wavelengths. Thus reconstructing the Faraday dispersion function from these limited measurements is ill-conditioned. In this paper, we propose three new reconstruction algorithms for RM synthesis based upon compressive sensing/sampling (CS). These algorithms are designed to be appropriate for Faraday thin sources only, thick sources only, and mixed sources respectively. Both visual and numerical results show that the new RM synthesis methods provide superior reconstructions of both magnitude and p...

  4. Broadband Radio Polarimetry and Faraday Rotation of 563 Extragalactic Radio Sources

    CERN Document Server

    Anderson, C S; Feain, I J; Franzen, T M O

    2015-01-01

    We present a broadband spectropolarimetric survey of 563 discrete, mostly unresolved radio sources between 1.3 \\& 2.0 GHz using data taken with the Australia Telescope Compact Array (ATCA). We have used rotation measure synthesis to identify Faraday complex polarized sources --- i.e. objects whose frequency-dependent polarization behaviour indicates the presence of material possessing complicated magnetoionic structure along the line of sight (LOS). For sources classified as Faraday complex, we have analyzed a number of their radio and multiwavelength properties to determine whether they differ from Faraday simple polarized sources (i.e. sources for which LOS magnetoionic structures are comparatively simple) in these properties. We use this information to constrain the physical nature of the magnetoionic structures responsible for generating the observed complexity. We detect Faraday complexity in 12\\% of polarized sources at $\\sim1'$ resolution, but demonstrate that underlying signal-to-noise limitations...

  5. "The Gammage Cup" as Utopian Literature for Children.

    Science.gov (United States)

    Russell, David L.

    1993-01-01

    Considers how Carol Kendall's fantasy novel, "The Gammage Cup," can be read as utopian literature for children. Provides a close reading and explication of Kendall's novel. Pronounces Kendall's novel a stimulating success providing hope for young readers. (HB)

  6. Geometric Phase Of The Faraday Rotation Of Electromagnetic Waves In Magnetized Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Jian Liu and Hong Qin

    2011-11-07

    The geometric phase of circularly polarized electromagnetic waves in nonuniform magnetized plasmas is studied theoretically. The variation of the propagation direction of circularly polarized waves results in a geometric phase, which also contributes to the Faraday rotation, in addition to the standard dynamical phase. The origin and properties of the geometric phase is investigated. The in uence of the geometric phase to plasma diagnostics using Faraday rotation is also discussed as an application of the theory.

  7. Dynamical behavior of digitations state in Faraday waves with a viscoelastic fluid

    Science.gov (United States)

    Cabeza, Cecilia; Rosen, Marta; Ferreyra, Gabriel; Bongiovanni, Gustavo

    2006-11-01

    Parametrically excited surface waves, well known as Faraday waves, are studied when finger structures are generated on the free surface. In this state, the surface breaks and ejects droplets from wave peaks when the applied force exceeds an acceleration threshold. In this work, both the chaotic and turbulent bifurcation behaviors of Faraday surface waves have been intensively studied and many different transitions have been examined and described. The spatial and temporal finger distribution is studied as a function of external acceleration.

  8. Broadband Radio Polarimetry and Faraday Rotation of 563 Extragalactic Radio Sources

    Science.gov (United States)

    Anderson, C. S.; Gaensler, B. M.; Feain, I. J.; Franzen, T. M. O.

    2015-12-01

    We present a broadband spectropolarimetric survey of 563 discrete, mostly unresolved radio sources between 1.3 and 2.0 GHz using data taken with the Australia Telescope Compact Array. We have used rotation-measure synthesis to identify Faraday-complex polarized sources, those objects whose frequency-dependent polarization behavior indicates the presence of material possessing complicated magnetoionic structure along the line of sight (LOS). For sources classified as Faraday-complex, we have analyzed a number of their radio and multiwavelength properties to determine whether they differ from Faraday-simple polarized sources (sources for which LOS magnetoionic structures are comparatively simple) in these properties. We use this information to constrain the physical nature of the magnetoionic structures responsible for generating the observed complexity. We detect Faraday complexity in 12% of polarized sources at ∼1‧ resolution, but we demonstrate that underlying signal-to-noise limitations mean the true percentage is likely to be significantly higher in the polarized radio source population. We find that the properties of Faraday-complex objects are diverse, but that complexity is most often associated with depolarization of extended radio sources possessing a relatively steep total intensity spectrum. We find an association between Faraday complexity and LOS structure in the Galactic interstellar medium (ISM) and claim that a significant proportion of the Faraday complexity we observe may be generated at interfaces of the ISM associated with ionization fronts near neutral hydrogen structures. Galaxy cluster environments and internally generated Faraday complexity provide possible alternative explanations in some cases.

  9. BROADBAND RADIO POLARIMETRY AND FARADAY ROTATION OF 563 EXTRAGALACTIC RADIO SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, C. S.; Gaensler, B. M.; Feain, I. J. [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Franzen, T. M. O., E-mail: craiga@physics.usyd.edu.au [CSIRO Astronomy and Space Science, Epping, NSW 1710 (Australia)

    2015-12-10

    We present a broadband spectropolarimetric survey of 563 discrete, mostly unresolved radio sources between 1.3 and 2.0 GHz using data taken with the Australia Telescope Compact Array. We have used rotation-measure synthesis to identify Faraday-complex polarized sources, those objects whose frequency-dependent polarization behavior indicates the presence of material possessing complicated magnetoionic structure along the line of sight (LOS). For sources classified as Faraday-complex, we have analyzed a number of their radio and multiwavelength properties to determine whether they differ from Faraday-simple polarized sources (sources for which LOS magnetoionic structures are comparatively simple) in these properties. We use this information to constrain the physical nature of the magnetoionic structures responsible for generating the observed complexity. We detect Faraday complexity in 12% of polarized sources at ∼1′ resolution, but we demonstrate that underlying signal-to-noise limitations mean the true percentage is likely to be significantly higher in the polarized radio source population. We find that the properties of Faraday-complex objects are diverse, but that complexity is most often associated with depolarization of extended radio sources possessing a relatively steep total intensity spectrum. We find an association between Faraday complexity and LOS structure in the Galactic interstellar medium (ISM) and claim that a significant proportion of the Faraday complexity we observe may be generated at interfaces of the ISM associated with ionization fronts near neutral hydrogen structures. Galaxy cluster environments and internally generated Faraday complexity provide possible alternative explanations in some cases.

  10. Diode-laser frequency stabilization based on the resonant Faraday effect

    Science.gov (United States)

    Wanninger, P.; Valdez, E. C.; Shay, T. M.

    1992-01-01

    The authors present the results of a method for frequency stabilizing laser diodes based on the resonant Faraday effects. A Faraday cell in conjunction with a polarizer crossed with respect to the polarization of the laser diode comprises the intracavity frequency selective element. In this arrangement, a laser pull-in range of 9 A was measured, and the laser operated at a single frequency with a linewidth less than 6 MHz.

  11. Effects of Faraday Rotation on Microwave Remote Sensing From Space at L-Band

    Science.gov (United States)

    LeVine, D. M.; Kao, M.

    1997-01-01

    The effect of Faraday rotation on the remote sensing of soil moisture from space is investigated using the International Reference Ionosphere (IRI) to obtain electron density profiles and the International Geomagnetic Reference Field (IGRF) to model the magnetic field. With a judicious choice of satellite orbit (6 am, sunsynchronous) the errors caused by ignoring Faraday rotation are less than 1 K at incidence angles less than 40 degrees.

  12. Effect of the Quadrupole Moment of a Rotating Massive Object on the Gravitational Faraday Rotation

    Institute of Scientific and Technical Information of China (English)

    陈贻汉; 邵常贵

    2002-01-01

    We study the rotation of the polarization plane for a ray of electromagnetic radiation propagating in the grav-itoelectromagnetic field caused by a rotating massive object with the quadrupole moment. The effect of thequadrupole moment on the gravitational Faraday rotation is investigated. It is found that the gravitational Fara-day effect of the quadrupole moment is negligible for Kerr black holes, but this effect is important for rapidlyrotating neutron stars.

  13. Watching the World Cup, one data point at a time

    OpenAIRE

    Silver, Curtis

    2014-01-01

    Sound the vuvuzelas, the World Cup is officially here. The biggest sporting event in the world is set to break all kinds of viewing records. Sporting in the digital world is just as much about stats as it is about the game itself. Enter Brandwatch. The social media analytics company has taken it upon itself to track social media statistics for the entire run of the World Cup with their new real-time data visualization tool.

  14. An investigation of home disadvantage in Davis Cup tennis.

    Science.gov (United States)

    Gayton, William F; Steinroeder, William; Bonnica, Corrine; Loignon, Andrew C

    2009-10-01

    Occurrence of the home disadvantage in Davis Cup tennis matches was examined by analyzing the outcome of Davis Cup finals matches from 1900 to 2007. There was no significant home disadvantage when Matches 1 and 2 were compared with Matches 4 and 5. However, there was a significant home disadvantage when Matches 1 and 2 were compared with Match 5. These findings are compared with those from earlier studies in which data from professional basketball and baseball were examined.

  15. Distance constant of the Risø cup anemometer

    OpenAIRE

    Kristensen, L.; Frost Hansen, O.

    2002-01-01

    The theory for cup-anemometer dynamics is presented in some detail and two methods of obtaining the distance constant lo are discussed. The first method is based on wind tunnel measurements: with a constant wind speed the cup anemometer is released from alocked position of the rotor and the increasing rotation rate recorded. It is concluded that the rapid increase in rotation rate makes the method very inaccurate. The second method consists of an analysis of turbulent, atmospheric of wind spe...

  16. Manipulating Tournaments in Cup and Round Robin Competitions

    CERN Document Server

    Russell, Tyrel; 10.1007/978-3-642-04428-1_3

    2009-01-01

    In sports competitions, teams can manipulate the result by, for instance, throwing games. We show that we can decide how to manipulate round robin and cup competitions, two of the most popular types of sporting competitions in polynomial time. In addition, we show that finding the minimal number of games that need to be thrown to manipulate the result can also be determined in polynomial time. Finally, we show that there are several different variations of standard cup competitions where manipulation remains polynomial.

  17. WSRT Faraday tomography of the Galactic ISM at \\lambda ~ 0.86 m

    CERN Document Server

    Schnitzeler, D H F M; De Bruyn, A G

    2008-01-01

    We investigate the properties of the Galactic ISM by applying Faraday tomography to a radio polarization data set in the direction of the Galactic anti-centre. We address the problem of missing large-scale structure in our data, and show that this does not play an important role for the results we present. The main peak of the Faraday depth spectra in our data set is not measurably resolved for about 8% of the lines of sight. An unresolved peak indicates a separation between the regions with Faraday rotation and synchrotron emission. However, cosmic rays pervade the ISM, and synchrotron emission would therefore also be produced where there is Faraday rotation. We suggest that the orientation of the magnetic field can separate the two effects. By modelling the thermal electron contribution to the Faraday depth, we map the strength of the magnetic field component along the line of sight. Polarized point sources in our data set have rotation measures that are comparable to the Faraday depths of the diffuse emiss...

  18. Linear theory on temporal instability of megahertz faraday waves for monodisperse microdroplet ejection.

    Science.gov (United States)

    Tsai, Shirley C; Tsai, Chen S

    2013-08-01

    A linear theory on temporal instability of megahertz Faraday waves for monodisperse microdroplet ejection based on mass conservation and linearized Navier-Stokes equations is presented using the most recently observed micrometer- sized droplet ejection from a millimeter-sized spherical water ball as a specific example. The theory is verified in the experiments utilizing silicon-based multiple-Fourier horn ultrasonic nozzles at megahertz frequency to facilitate temporal instability of the Faraday waves. Specifically, the linear theory not only correctly predicted the Faraday wave frequency and onset threshold of Faraday instability, the effect of viscosity, the dynamics of droplet ejection, but also established the first theoretical formula for the size of the ejected droplets, namely, the droplet diameter equals four-tenths of the Faraday wavelength involved. The high rate of increase in Faraday wave amplitude at megahertz drive frequency subsequent to onset threshold, together with enhanced excitation displacement on the nozzle end face, facilitated by the megahertz multiple Fourier horns in resonance, led to high-rate ejection of micrometer- sized monodisperse droplets (>10(7) droplets/s) at low electrical drive power (<;1 W) with short initiation time (<;0.05 s). This is in stark contrast to the Rayleigh-Plateau instability of a liquid jet, which ejects one droplet at a time. The measured diameters of the droplets ranging from 2.2 to 4.6 μm at 2 to 1 MHz drive frequency fall within the optimum particle size range for pulmonary drug delivery.

  19. Splash-cup plants accelerate raindrops to disperse seeds.

    Science.gov (United States)

    Amador, Guillermo J; Yamada, Yasukuni; McCurley, Matthew; Hu, David L

    2013-02-01

    The conical flowers of splash-cup plants Chrysosplenium and Mazus catch raindrops opportunistically, exploiting the subsequent splash to disperse their seeds. In this combined experimental and theoretical study, we elucidate their mechanism for maximizing dispersal distance. We fabricate conical plant mimics using three-dimensional printing, and use high-speed video to visualize splash profiles and seed travel distance. Drop impacts that strike the cup off-centre achieve the largest dispersal distances of up to 1 m. Such distances are achieved because splash speeds are three to five times faster than incoming drop speeds, and so faster than the traditionally studied splashes occurring upon horizontal surfaces. This anomalous splash speed is because of the superposition of two components of momentum, one associated with a component of the drop's motion parallel to the splash-cup surface, and the other associated with film spreading induced by impact with the splash-cup. Our model incorporating these effects predicts the observed dispersal distance within 6-18% error. According to our experiments, the optimal cone angle for the splash-cup is 40°, a value consistent with the average of five species of splash-cup plants. This optimal angle arises from the competing effects of velocity amplification and projectile launching angle.

  20. Relation between magnetization and Faraday angles produced by ultrafast spin-flip processes within the three-level Λ-type system

    Energy Technology Data Exchange (ETDEWEB)

    Hinschberger, Y. [Departamento de Física e Astronomia, Instituto de Física dos Materiais da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Lavoine, J. P. [Departement of Ultrafast Optics and Nanophotonics, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, CNRS, Université de Strasbourg, 23, Rue du Loess, BP 43, 67034 Strasbourg-Cedex 2 (France)

    2015-08-07

    Ultrafast magneto-optical (MO) experiments constitute a powerful tool to explore the magnetization dynamics of diverse materials. Over the last decade, there have been many theoretical and experimental developments on this subject. However, the relation between the magnetization dynamics and the transient MO response still remains unclear. In this work, we calculate the magnetization of a material, as well as the magneto-optical rotation and ellipticity angles measured in a single-beam experiment. Then, we compare the magnetization to the MO response. The magnetic material is modeled by a three-level Λ-type system, which represents a simple model to describe MO effects induced by an ultrafast laser pulse. Our calculations use the density matrix formalism, while the dynamics of the system is obtained by solving the Lindblad equation taking into account population relaxation and dephasing processes. Furthermore, we consider the Faraday rotation of the optical waves that simultaneously causes spin-flip. We show that the Faraday angles remain proportional to the magnetization only if the system has reached the equilibrium-state, and that this proportionality is directly related to the population and coherence decay rates. For the non-equilibrium situation, the previous proportionality relation is no longer valid. We show that our model is able to interpret some recent experimental results obtained in a single-pulse experiment. We further show that, after a critical pulse duration, the decrease of the ellipticity as a function of the absorbed energy is a characteristic of the system.

  1. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Ninth Edition Optics: Ninth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommen

  2. Musik sebagai Wujud Eksistensi dalam Gelaran World Cup

    Directory of Open Access Journals (Sweden)

    Michael HB Raditya

    2014-11-01

    Full Text Available We Are One atau “Ole Ola” merupakan lagu resmi dari gelaran World Cup. Setiap World Cupmempunyai lagu resminya ditiap gelarannya. Dalam keberlangsungannya, setiap lagu world cupmembutuhkan pertimbangan dalam pembentukannya. Aspek-aspek seperti budaya, sosial, politikdan lainya menjadi alasan penting dalam pembentukannya. Pembentukan Ole Ola didasarkan padaproses hibriditas budaya lokal dan global. Perpaduan samba dan hip hop menjadi variant dalampembentukannya. Perpaduan tersebut membentuk identitas untuk lagu itu sendiri, dan untuk gelaranworld cup. Eksistensi dari lagu sehingga makin terasa karena perpaduan yang membentuk identitas.Terlebih lagu tersebut tercipta tidak hanya karena gelaran, tetapi mempunyai fungsi dan guna untukmasyarakat. Musik sebagai media dalam mengkonstruksi pesan atas kepentingan. Musik membentukidentitas, dan mempunyai eksistensi dalam keberlangsungannya. Musik tidak lagi hanya berfungsisebagai musik saja, tetapi musik mempunyai peran dalam pembentukan identitas dan menjamineksistensi. Music as a form of Existance in the World Cup Performance. We are one or Ole Ola is the officialsong of the world cup performance. Every world cup has its official song in each event. In its development ofexistance, every song in world cup needs requires of consideration for creating process. Aspects such as cultural,social, politics and others become the important reason for creation. The creating proses of Ole Ola song isbased on the local and global cultural hybridity. The combination of samba and hip hop is a primary varianton creating process. The combination creates an identity for the song itself, and for world cup identity. Theexistance of Ole Ola is stronger because the combination may create the new identity. Moreover, the songcreated is not only for the event, but also has a function and purpose to society. Music is as a medium inconstructing the messages of interest. Music creates an identity, and has an existance in its

  3. Probing the central parsecs of AGN using Faraday Rotation

    Science.gov (United States)

    Zavala, R. T.; Taylor, G. B.

    2002-05-01

    A broad frequency range and low instrumental polarization makes the Very Long Baseline Array (VLBA) an ideal instrument for studying polarimetry at sub-milliarcsecond resolution. To take advantage of these unique capabilities we have conducted a multi-frequency polarization survey of 40 radio-loud AGN (Quasars, BL Lacs, and radio galaxies). Our aim is to use Faraday Rotation Measures (RMs) as a probe of the central 1-50 parsecs of these objects. The RM is produced by the line of sight magnetic field weighted by the electron density. Using the electron density established through spectral line diagnostics a magnetic field strength and topology can be estimated within a few parsecs of the central engines of these AGN. The observations for the survey are complete, and we present the first results for 8 quasars, 5 BL Lacs, and 4 radio galaxies. The magnitudes for the RMs range from several thousand rad m-2 in the quasars and radio galaxies to a few hundred rad m-2 in the BL Lac objects. These values are in agreement with the basic ideas of the unified model for AGN. We also observe variations in the RM on small spatial (time scales ( ~ 6 months) in the quasars 3C 273 and 3C 279. R.T.Z. gratefully acknowledges support from a pre-doctoral research appointment at NRAO and from the New Mexico Alliance for Graduate Education and the Professiorate through NSF grant HRD-0086701.

  4. Scaling properties of weakly nonlinear coefficients in the Faraday problem.

    Science.gov (United States)

    Skeldon, A C; Porter, J

    2011-07-01

    Interesting and exotic surface wave patterns have regularly been observed in the Faraday experiment. Although symmetry arguments provide a qualitative explanation for the selection of some of these patterns (e.g., superlattices), quantitative analysis is hindered by mathematical difficulties inherent in a time-dependent, free-boundary Navier-Stokes problem. More tractable low viscosity approximations are available, but these do not necessarily capture the moderate viscosity regime of the most interesting experiments. Here we focus on weakly nonlinear behavior and compare the scaling results derived from symmetry arguments in the low viscosity limit with the computed coefficients of appropriate amplitude equations using both the full Navier-Stokes equations and a reduced set of partial differential equations due to Zhang and Vinãls. We find the range of viscosities over which one can expect "low viscosity" theories to hold. We also find that there is an optimal viscosity range for locating superlattice patterns experimentally-large enough that the region of parameters giving stable patterns is not impracticably small, yet not so large that crucial resonance effects are washed out. These results help explain some of the discrepancies between theory and experiment.

  5. A sensitive Faraday rotation setup using triple modulation

    Energy Technology Data Exchange (ETDEWEB)

    Phelps, G.; Abney, J.; Broering, M.; Korsch, W. [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506 (United States)

    2015-07-15

    The utilization of polarized targets in scattering experiments has become a common practice in many major accelerator laboratories. Noble gases are especially suitable for such applications, since they can be easily hyper-polarized using spin exchange or metastable pumping techniques. Polarized helium-3 is a very popular target because it often serves as an effective polarized neutron due to its simple nuclear structure. A favorite cell material to generate and store polarized helium-3 is GE-180, a relatively dense aluminosilicate glass. In this paper, we present a Faraday rotation method, using a new triple modulation technique, where the measurement of the Verdet constants of SF57 flint glass, pyrex glass, and air was tested. The sensitivity obtained shows that this technique may be implemented in future cell wall characterization and thickness measurements. We also discuss the first ever extraction of the Verdet constant of GE-180 glass for four wavelength values of 632 nm, 773 nm, 1500 nm, and 1547 nm, whereupon the expected 1/λ{sup 2} dependence was observed.

  6. Photoswitchable Faraday effect in EuS-Au nanosystems

    Energy Technology Data Exchange (ETDEWEB)

    Kawashima, Akira; Nakanishi, Takayuki; Kitagawa, Yuichi; Fushimi, Koji; Hasegawa, Yasuchika [Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, North-13 West-8, Kita-ku, 060-8628, Sapporo (Japan)

    2016-01-15

    Effective photoswitchable europium sulfide nanocrystals with gold nanoparticles using dithiol (DDT: 1,10-decanedithiol) joint molecules, EuS-Au nanosystems, are demonstrated. The TEM image indicates the formation of EuS-Au nanosystems composed of cube-shaped EuS nanocrystals and spherical Au nanoparticles. Under visible-light irradiation, a drastic change of absorption band of EuS-Au nanosystems at around 600 nm was observed. The Faraday effects of EuS-Au nanosystems were estimated using magnetic circular dichroism (MCD) measurements. The effective change of the MCD spectra of EuS-Au nanosystems under visible-light irradiation was successfully observed at around 670 nm for the first time. The effective reversible changes in MCD spectra with the alternative irradiation cycles of visible light (>440 nm) and dark are also presented. The decrease rate of rotation angle at 670 nm of EuS-Au nanosystems is larger than that of absorbance. These results indicate that the effective change of MCD spectra of EuS-Au nanosystems would be dominated not only by a drastic change of absorption band related to enhanced LSPR of Au nanoparticles but also by specific interaction between EuS and Au in nanosystem under irradiation. Illustration of photoswitch and TEM image of EuS-Au nanosystems. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Homogenized boundary conditions and resonance effects in Faraday cages

    Science.gov (United States)

    Hewett, D. P.; Hewitt, I. J.

    2016-05-01

    We present a mathematical study of two-dimensional electrostatic and electromagnetic shielding by a cage of conducting wires (the so-called `Faraday cage effect'). Taking the limit as the number of wires in the cage tends to infinity, we use the asymptotic method of multiple scales to derive continuum models for the shielding, involving homogenized boundary conditions on an effective cage boundary. We show how the resulting models depend on key cage parameters such as the size and shape of the wires, and, in the electromagnetic case, on the frequency and polarization of the incident field. In the electromagnetic case, there are resonance effects, whereby at frequencies close to the natural frequencies of the equivalent solid shell, the presence of the cage actually amplifies the incident field, rather than shielding it. By appropriately modifying the continuum model, we calculate the modified resonant frequencies, and their associated peak amplitudes. We discuss applications to radiation containment in microwave ovens and acoustic scattering by perforated shells.

  8. A Sensitive Faraday Rotation Setup Using Triple Modulation

    CERN Document Server

    Phelps, Gretchen; Broering, Mark; Korsch, Wolfgang

    2015-01-01

    The utilization of polarized targets in scattering experiments has become a common practice in many major accelerator laboratories. Noble gases are especially suitable for such applications, since they can be easily hyper-polarized using spin exchange or metastable pumping techniques. Polarized helium-3 is a very popular target because it often serves as an effective polarized neutron due to its simple nuclear structure. A favorite cell material to generate and store polarized helium-3 is GE-180, a relatively dense aluminosilicate glass. In this paper, we present a Faraday rotation method, using a new triple modulation technique, where the measurement of the Verdet constants of SF57 flint glass, pyrex glass, and air were tested. The sensitivity obtained shows that this technique may be implemented in future cell wall characterization and thickness measurements. We also discuss the first ever extraction of the Verdet constant of GE-180 glass for four wavelength values of 632 nm, 773 nm, 1500 nm, and 1547 nm, w...

  9. Theory of Kerr and Faraday rotation in Topological Weyl Semimetals

    Science.gov (United States)

    Kargarian, Mehdi; Randeria, Mohit; Trivedi, Nandini

    2015-03-01

    Topological Weyl semimetals are characterized by bulk Dirac nodes separated in momentum space by a distance 2 b and lead to Fermi arcs in the surfaces electronic structure. We calculate the Faraday θF and Kerr θK angles for electromagnetic waves scattered from such a Weyl semimetal using the Kubo formalism. (1) For thin films with electromagnetic radiation incident on a surface without arcs, we show that θK = bd / απ and θF = απ / bd where α is the fine structure constant, and the film thickness d film on a substrate. (2) In the case when the electromagnetic radiation is incident on the surface with arcs, the wave propagating inside the material acquires a longitudinal component of the electric field proportional to b. We discuss the implications of our results for thin films of pyrochlore iridates, and also for the recently discovered Dirac semimetals in a magnetic field. We acknowledge the support of the CEM, an NSF MRSEC, under Grant DMR-1420451.

  10. Homogenized boundary conditions and resonance effects in Faraday cages.

    Science.gov (United States)

    Hewett, D P; Hewitt, I J

    2016-05-01

    We present a mathematical study of two-dimensional electrostatic and electromagnetic shielding by a cage of conducting wires (the so-called 'Faraday cage effect'). Taking the limit as the number of wires in the cage tends to infinity, we use the asymptotic method of multiple scales to derive continuum models for the shielding, involving homogenized boundary conditions on an effective cage boundary. We show how the resulting models depend on key cage parameters such as the size and shape of the wires, and, in the electromagnetic case, on the frequency and polarization of the incident field. In the electromagnetic case, there are resonance effects, whereby at frequencies close to the natural frequencies of the equivalent solid shell, the presence of the cage actually amplifies the incident field, rather than shielding it. By appropriately modifying the continuum model, we calculate the modified resonant frequencies, and their associated peak amplitudes. We discuss applications to radiation containment in microwave ovens and acoustic scattering by perforated shells.

  11. Impact biomechanics and pelvic deformation during insertion of press-fit acetabular cups.

    Science.gov (United States)

    Kroeber, Markus; Ries, Michael D; Suzuki, Yoshihiro; Renowitzky, Glen; Ashford, Frank; Lotz, Jeff

    2002-04-01

    Five fresh cadaver pelves were cleaned of soft tissue and instrumented with strain gauges. The acetabula were reamed, and a cementless cup, oversized at the periphery, was inserted. The applied force and cup acceleration were measured during insertion and used to calculate an effective mass of the cup, insertion device, and pelvis during each impact. Periacetabular strains increased variably during cup seating. After the cups were seated, strains continued to increase with postseating impacts. The effective mass remained constant throughout the test, indicating that cup seating is not associated with a change in acceleration. This finding implies that an accurate assessment of cup seating cannot be inferred by surgeon proprioception during impaction, and use of an apical hole in the cup is necessary to determine when the cup has seated.

  12. New is the well-forgotten old: The use of dry cupping in musculoskeletal medicine.

    Science.gov (United States)

    Rozenfeld, Evgeni; Kalichman, Leonid

    2016-01-01

    Cupping is an ancient technique used in treating pain and various disorders. Different techniques have been developed over time, however, applying a cup to create suction over a painful area, is common to all. Dry or fire cupping, used on the intact skin, leaves bluish circular hematomas. Recently, interest in cupping has re-emerged and subsequently, several studies have begun to investigate the mechanisms of cupping therapy. Mechanically, cupping increases blood circulation, whereas physiologically it activates the immune system and stimulates the mechanosensitive fibers, thus leading to a reduction in pain. There is initial scientific evidence that dry cupping is able to reduce musculoskeletal pain. Since cupping is an inexpensive, noninvasive and low-risk (if performed by a trained practitioner) therapeutic modality, we believe that it should be included in the arsenal of musculoskeletal medicine. It is essential to perform additional studies clarifying the biological mechanism and clinical effects of cupping.

  13. Grouped retinae and tapetal cups in some Teleostian fish: occurrence, structure, and function.

    Science.gov (United States)

    Francke, Mike; Kreysing, Moritz; Mack, Andreas; Engelmann, Jacob; Karl, Anett; Makarov, Felix; Guck, Jochen; Kolle, Mathias; Wolburg, Hartwig; Pusch, Roland; von der Emde, Gerhard; Schuster, Stefan; Wagner, Hans-Joachim; Reichenbach, Andreas

    2014-01-01

    This article presents a summary and critical review of what is known about the 'grouped retina', a peculiar type of retinal organization in fish in which groups of photoreceptor cell inner and outer segments are arranged in spatially separated bundles. In most but not all cases, these bundles are embedded in light-reflective cups that are formed by the retinal pigment epithelial cells. These cups constitute a specialized type of retinal tapetum (i.e., they are biological 'mirrors' that cause eye shine) and appear to be optimized for different purposes in different fishes. Generally, the large retinal pigment epithelial cells are filled with light-reflecting photonic crystals that consist of guanine, uric acid, or pteridine depending on species, and which ensure that the incoming light becomes directed onto the photoreceptor outer segments. This structural specialization has so far been found in representatives of 17 fish families; of note, not all members of a given family must possess a grouped retina, and the 17 families are not all closely related to each other. In many cases (e.g., in Osteoglossomorpha and Aulopiformes) the inner surface of the cup is formed by three to four layers of strikingly regularly shaped and spaced guanine platelets acting as an optical multilayer. It has been estimated that this provides an up to 10fold increase of the incident light intensity. In certain deep-sea fish (many Aulopiformes and the Polymixidae), small groups of rods are embedded in such 'parabolic mirrors'; most likely, this is an adaptation to the extremely low light intensities available in their habitat. Some of these fishes additionally possess similar tapetal cups that surround individual cones and, very likely, also serve as amplifiers of the weak incident light. In the Osteoglossomorpha, however, that inhabit the turbid water of rivers or streams, the structure of the cups is more complex and undergoes adaptation-dependent changes. At dim daylight, probably

  14. Development of cup shaped microneedle array for transdermal drug delivery.

    Science.gov (United States)

    Vinayakumar, Kadayar B; Hegde, Gopal M; Ramachandra, Subbaraya G; Nayak, Mangalore M; Dinesh, Narasimhian S; Rajanna, Konandur

    2015-06-08

    Microneedle technology is one of the attractive methods in transdermal drug delivery. However, the clinical applications of this method are limited owing to: complexity in the preparation of multiple coating solutions, drug leakage while inserting the microneedles into the skin and the outer walls of the solid microneedle can hold limited quantity of drug. Here, the authors present the fabrication of an array of rectangular cup shaped silicon microneedles, which provide for reduced drug leakage resulting in improvement of efficiency of drug delivery and possibility of introducing multiple drugs. The fabricated solid microneedles with rectangular cup shaped tip have a total height of 200 μm. These cup shaped tips have dimensions: 60 × 60 μm (length × breadth) with a depth of 60 μm. The cups are filled with drug using a novel in-house built drop coating system. Successful drug dissolution was observed when the coated microneedle was used on mice. Also, using the above method, it is possible to fill the cups selectively with different drugs, which enables simultaneous multiple drug delivery.

  15. Octopus-like suction cups: from natural to artificial solutions.

    Science.gov (United States)

    Tramacere, F; Follador, M; Pugno, N M; Mazzolai, B

    2015-05-13

    Octopus suckers are able to attach to all nonporous surfaces and generate a very strong attachment force. The well-known attachment features of this animal result from the softness of the sucker tissues and the surface morphology of the portion of the sucker that is in contact with objects or substrates. Unlike artificial suction cups, octopus suckers are characterized by a series of radial grooves that increase the area subjected to pressure reduction during attachment. In this study, we constructed artificial suction cups with different surface geometries and tested their attachment performances using a pull-off setup. First, smooth suction cups were obtained for casting; then, sucker surfaces were engraved with a laser cutter. As expected, for all the tested cases, the engraving treatment enhanced the attachment performance of the elastomeric suction cups compared with that of the smooth versions. Moreover, the results indicated that the surface geometry with the best attachment performance was the geometry most similar to octopus sucker morphology. The results obtained in this work can be utilized to design artificial suction cups with higher wet attachment performance.

  16. Dielectric elastomer actuators for octopus inspired suction cups.

    Science.gov (United States)

    Follador, M; Tramacere, F; Mazzolai, B

    2014-09-25

    Suction cups are often found in nature as attachment strategy in water. Nevertheless, the application of the artificial counterpart is limited by the dimension of the actuators and their usability in wet conditions. A novel design for the development of a suction cup inspired by octopus suckers is presented. The main focus of this research was on the modelling and characterization of the actuation unit, and a first prototype of the suction cup was realized as a proof of concept. The actuation of the suction cup is based on dielectric elastomer actuators. The presented device works in a wet environment, has an integrated actuation system, and is soft. The dimensions of the artificial suction cups are comparable to proximal octopus suckers, and the attachment mechanism is similar to the biological counterpart. The design approach proposed for the actuator allows the definition of the parameters for its development and for obtaining a desired pressure in water. The fabricated actuator is able to produce up to 6 kPa of pressure in water, reaching the maximum pressure in less than 300 ms.

  17. Classification of operational characteristics of commercial cup-anemometers

    Energy Technology Data Exchange (ETDEWEB)

    Friis Pedersen, T.; Schmidt Paulsen, U. [Risoe National Lab., Wind Energy and Atmospheric Physics Dept., Roskilde (Denmark)

    1999-03-01

    The present classification of cup-anemometers is based on a procedure for classification of operational characteristics of cup-anemometers that was proposed at the EWEC `97 conference in Dublin 1997. Three definitions of wind speed are considered. The average longitudinal wind speed (ID), the average horizontal wind speed (2D) and the average vector wind speed (3D). The classification is provided in these terms, and additionally, the turbulence intensities, which are defined from the same wind speed definitions. The commercial cup-anemometers have all been calibrated in wind tunnel for the normal calibrations and angular characteristics. Friction was measured by blywheel testing, where the surrounding temperatures were varied over a wide range. The characteristics of the cup-anemometers have been fitted to the heuristic dynamic model, and the response has been calculated in time domain for prescribed ranges of external operational conditions. The results are presented in ranges of maximum deviations of `measured` average wind speed. For each definition of wind speed and turbulence intensity, the cup-anemometers are ranked according to the most precise instrument. Finally, the most important systematic error sources are commented. (au)

  18. Mathematical analysis of the effect of rotor geometry on cup anemometer response.

    Science.gov (United States)

    Sanz-Andrés, Ángel; Pindado, Santiago; Sorribes-Palmer, Félix

    2014-01-01

    The calibration coefficients of two commercial anemometers equipped with different rotors were studied. The rotor cups had the same conical shape, while the size and distance to the rotation axis varied. The analysis was based on the 2-cup positions analytical model, derived using perturbation methods to include second-order effects such as pressure distribution along the rotating cups and friction. The comparison with the experimental data indicates a nonuniform distribution of aerodynamic forces on the rotating cups, with higher forces closer to the rotating axis. The 2-cup analytical model is proven to be accurate enough to study the effect of complex forces on cup anemometer performance.

  19. Mathematical Analysis of the Effect of Rotor Geometry on Cup Anemometer Response

    Directory of Open Access Journals (Sweden)

    Ángel Sanz-Andrés

    2014-01-01

    Full Text Available The calibration coefficients of two commercial anemometers equipped with different rotors were studied. The rotor cups had the same conical shape, while the size and distance to the rotation axis varied. The analysis was based on the 2-cup positions analytical model, derived using perturbation methods to include second-order effects such as pressure distribution along the rotating cups and friction. The comparison with the experimental data indicates a nonuniform distribution of aerodynamic forces on the rotating cups, with higher forces closer to the rotating axis. The 2-cup analytical model is proven to be accurate enough to study the effect of complex forces on cup anemometer performance.

  20. Faraday tomography of the local interstellar medium with LOFAR: Galactic foregrounds towards IC 342

    Science.gov (United States)

    Van Eck, C. L.; Haverkorn, M.; Alves, M. I. R.; Beck, R.; de Bruyn, A. G.; Enßlin, T.; Farnes, J. S.; Ferrière, K.; Heald, G.; Horellou, C.; Horneffer, A.; Iacobelli, M.; Jelić, V.; Martí-Vidal, I.; Mulcahy, D. D.; Reich, W.; Röttgering, H. J. A.; Scaife, A. M. M.; Schnitzeler, D. H. F. M.; Sobey, C.; Sridhar, S. S.

    2017-01-01

    Magnetic fields pervade the interstellar medium (ISM), but are difficult to detect and characterize. The new generation of low-frequency radio telescopes, such as the Low Frequency Array (LOFAR: a Square Kilometre Array-low pathfinder), provides advancements in our capability of probing Galactic magnetism through low-frequency polarimetry. Maps of diffuse polarized radio emission and the associated Faraday rotation can be used to infer properties of, and trace structure in, the magnetic fields in the ISM. However, to date very little of the sky has been probed at high angular and Faraday depth resolution. We observed a 5° by 5° region centred on the nearby galaxy IC 342 (ℓ = 138.2°,b = + 10.6°) using the LOFAR high-band antennae in the frequency range 115-178 MHz. We imaged this region at 4'.5x3'.8 resolution and performed Faraday tomography to detect foreground Galactic polarized synchrotron emission separated by Faraday depth (different amounts of Faraday rotation). Our Faraday depth cube shows a rich polarized structure, with up to 30 K of polarized emission at 150 MHz. We clearly detect two polarized features that extend over most of the field, but are clearly separated in Faraday depth. Simulations of the behaviour of the depolarization of Faraday-thick structures at such low frequencies show that such structures would be too strongly depolarized to explain the observations. These structures are therefore rejected as the source of the observed polarized features. Only Faraday thin structures will not be strongly depolarized at low frequencies; producing such structures requires localized variations in the ratio of synchrotron emissivity to Faraday depth per unit distance. Such variations can arise from several physical phenomena, such as a transition between regions of ionized and (mostly) neutral gas. We conclude that the observed polarized emission is Faraday thin, and propose that the emission originates from two mostly neutral clouds in the local ISM

  1. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Eighth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommended for engineering st

  2. Barreled-beer cup vendor (FSCB-100); Tarunama cup benda (FSCB-100)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-01-10

    Development was made on an automatic vending machine to vend barreled beer in a cup with stabilized quality. Its major features are as follows: (1) a double cooling system using water cooling and air cooling simultaneously was adopted to make it possible to maintain the beer freshness and pour it stably; (2) a full-automatic gas pressure control system was adopted to detect beer temperature, and adjust the pressure to adequate level; (3) an automatic rinsing system was adopted that has made troublesome pipe rinsing possible with just pressing a button to simplify maintenance work; and (4) a new automatic two-barrel changeover mechanism was developed to achieve first-in-first-out of barrels, control the freshness, suppress bubble generation, and reduce beer loss quantity. (translated by NEDO)

  3. A view through Faraday's Fog: Parsec scale Rotation Measures in AGN

    Science.gov (United States)

    Zavala, R. T.; Taylor, G. B.

    2002-12-01

    The magnetic field orientations and strengths, and thermal gas densities and pressures can all be probed on parsec scales in active galactic nuclei using VLBA polarimetry. Faraday's Fog, a foreground Faraday rotating medium in the AGN core, is what makes this possible. To take advantage of this effect to explore the central engine we have completed a rotation measure survey of 40 quasars, BL Lac objects, and radio galaxies. We summarize a few interesting results here. Quasars and radio galaxies show substantial rotation measures (> 1000 rad m-2) but BL Lacertae objects do not. A decreasing core percent polarization appears correlated with an increasing Faraday rotation measure. Faraday depolarization cannot account for this as the rotation measures are approximately two orders of magnitude too small to cause depolarization across an observing bandwidth. A more likely explanation for the depolarization is a gradient in the rotation measure across the synthesized beam. Multi-epoch observations of 3C 279 suggest that rotation measure variations may be tracked over time by changes in the percent polarization. The core rotation measures of the sample appears to be independent of core dominance. We will suggest possible identifications of the Faraday screen. R.T.Z gratefully acknowledges support from a pre-doctoral research appointment at NRAO and from the New Mexico Alliance for Graduate Education and the Professiorate through NSF grant HRD-0086701.

  4. Diagnostics of the solar corona from comparison between Faraday rotation measurements and magnetohydrodynamic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Le Chat, G.; Cohen, O. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Kasper, J. C. [Atmospheric, Oceanic and Space Sciences Department, University of Michigan, Ann Arbor, MI (United States); Spangler, S. R., E-mail: gaetan.lechat@obspm.fr [Department of Physics and Astronomy, University of Iowa, Iowa City, IA (United States)

    2014-07-10

    Polarized natural radio sources passing behind the Sun experience Faraday rotation as a consequence of the electron density and magnetic field strength in coronal plasma. Since Faraday rotation is proportional to the product of the density and the component of the magnetic field along the line of sight of the observer, a model is required to interpret the observations and infer coronal structures. Faraday rotation observations have been compared with relatively ad hoc models of the corona. Here for the first time we compare these observations with magnetohydrodynamic (MHD) models of the solar corona driven by measurements of the photospheric magnetic field. We use observations made with the NRAO Very Large Array of 34 polarized radio sources occulted by the solar corona between 5 and 14 solar radii. The measurements were made during 1997 May, and 2005 March and April. We compare the observed Faraday rotation values with values extracted from MHD steady-state simulations of the solar corona. We find that (1) using a synoptic map of the solar magnetic field just one Carrington rotation off produces poorer agreements, meaning that the outer corona changes in the course of one month, even in solar minimum; (2) global MHD models of the solar corona driven by photospheric magnetic field measurements are generally able to reproduce Faraday rotation observations; and (3) some sources show significant disagreement between the model and the observations, which appears to be a function of the proximity of the line of sight to the large-scale heliospheric current sheet.

  5. Position control of desiccation cracks by memory effect and Faraday waves.

    Science.gov (United States)

    Nakayama, Hiroshi; Matsuo, Yousuke; Takeshi, Ooshida; Nakahara, Akio

    2013-01-01

    Pattern formation of desiccation cracks on a layer of a calcium carbonate paste is studied experimentally. This paste is known to exhibit a memory effect, which means that a short-time application of horizontal vibration to the fresh paste predetermines the direction of the cracks that are formed after the paste is dried. While the position of the cracks (as opposed to their direction) is still stochastic in the case of horizontal vibration, the present work reports that their positioning is also controllable, at least to some extent, by applying vertical vibration to the paste and imprinting the pattern of Faraday waves, thus breaking the translational symmetry of the system. The experiments show that the cracks tend to appear in the node zones of the Faraday waves: in the case of stripe-patterned Faraday waves, the cracks are formed twice more frequently in the node zones than in the anti-node zones, presumably due to the localized horizontal motion. As a result of this preference of the cracks to the node zones, the memory of the square lattice pattern of Faraday waves makes the cracks run in the oblique direction differing by 45 degrees from the intuitive lattice direction of the Faraday waves.

  6. Static magnetic Faraday rotation spectroscopy combined with a differential scheme for OH detection

    Science.gov (United States)

    Zhao, Weixiong; Deng, Lunhua; Qian, Xiaodong; Fang, Bo; Gai, Yanbo; Chen, Weidong; Gao, Xiaoming; Zhang, Weijun

    2015-04-01

    The hydroxyl (OH) radical plays a critical role in atmospheric chemistry due to its high reactivity with volatile organic compounds (VOCs) and other trace gaseous species. Because of its very short life time and very low concentration in the atmosphere, interference-free high sensitivity in-situ OH monitoring by laser spectroscopy represents a real challenge. Faraday rotation spectroscopy (FRS) relies on the particular magneto-optic effect observed for paramagnetic species, which makes it capable of enhancing the detection sensitivity and mitigation of spectral interferences from diamagnetic species in the atmosphere. When an AC magnetic field is used, the Zeeman splitting of the molecular absorption line (and thus the magnetic circular birefringence) is modulated. This provides an 'internal modulation' of the sample, which permits to suppress the external noise like interference fringes. An alternative FRS detection scheme is to use a static magnetic field (DC-field) associated with laser wavelength modulation to effectively modulate the Zeeman splitting of the absorption lines. In the DC field case, wavelength modulation of the laser frequency can provide excellent performance compared to most of the sensing systems based on direct absorption and wavelength modulation spectroscopy. The dimension of the DC solenoid is not limited by the resonant frequency of the RLC circuit, which makes large dimension solenoid coil achievable and the absorption base length could be further increased. By employing a combination of the environmental photochemical reactor or smog chamber with multipass absorption cell, one can lower the minimum detection limit for high accuracy atmospheric chemistry studies. In this paper, we report on the development of a DC field based FRS in conjunction with a balanced detection scheme for OH radical detection at 2.8 μm and the construction of OH chemistry research platform which combined a large dimension superconducting magnetic coil with the

  7. A novel cupping-assisted plasma treatment for skin disinfection

    Science.gov (United States)

    Xiong, Zilan; Graves, David B.

    2017-02-01

    A novel plasma treatment method/plasma source called cupping-assisted plasma treatment/source for skin disinfection is introduced. The idea combines ancient Chinese ‘cupping’ technology with plasma sources to generate active plasma inside an isolated, pressure-controlled chamber attached to the skin. Advantages of lower pressure include reducing the threshold voltage for plasma ignition and improving the spatial uniformity of the plasma treatment. In addition, with reduced pressure inside the cup, skin pore permeability might be increased and it improves attachment of the plasma device to the skin. Moreover, at a given pressure, plasma-generated active species are restricted inside the cup, raising local reactive species concentration and enhancing the measured surface disinfection rate. A surface micro-discharge (SMD) device is used as an example of a working plasma source. We report discharge characteristics and disinfection efficiency as a function of pressure and applied voltage.

  8. Characterisation and classification of RISØ P2546 cup anemometer

    DEFF Research Database (Denmark)

    Friis Pedersen, Troels

    2003-01-01

    The characteristics of the RISØ P2546 cup anemometer were investigated in detail by wind tunnel and laboratory tests. The characteristics include accredited calibration, tilt response measurements for tilt angles between -40° to 40°, gust responsemeasurements at 8m/s and turbulence intensities...... of 10%, 16% and 23%, step response measurements at step wind speeds 3,7, 8, 11,9 and 15,2m/s, measurement of torque characteristics at 8m/s, rotor inertia measurements and measurements of friction ofbearings at temperatures -20°C to 40°C. Characteristics were fitted to a time domain cup anemometer model....... The characteristics were transformed into the CLASSCUP classification scheme, and were related to the cup anemometer requirements in the Danishcertification system and in the IEC 61400-121 Committee Draft....

  9. Characterisation and classification of RISØ P2546 cup anemometer

    DEFF Research Database (Denmark)

    Friis Pedersen, Troels

    2004-01-01

    The characteristics of the RISØ P2546 cup anemometer were investigated in detail by wind tunnel and laboratory tests. The characteristics include accredited calibration, tilt response measurements for tilt angles between -40° to 40°, gust responsemeasurements at 8m/s and turbulence intensities...... of 10%, 16% and 23%, step response measurements at step wind speeds 3,7, 8, 11,9 and 15,2m/s, measurement of torque characteristics at 8m/s, rotor inertia measurements and measurements of friction ofbearings at temperatures -20°C to 40°C. Characteristics were fitted to a time domain cup anemometer model....... The characteristics were transformed into the CLASSCUP classification scheme, and were related to the cup anemometer requirements in the Danishcertification system and in the IEC 61400-121 Committee Draft....

  10. Characterisation and classification of RISOe P2546 cup anemometer

    Energy Technology Data Exchange (ETDEWEB)

    Friis Pedersen, T.

    2003-04-01

    The characteristics of the RISOe P2546 cup anemometer were investigated in detail by wind tunnel and laboratory tests. The characteristics include accredited calibration, tilt response measurements for tilt angles between -40 degC to 40 degC, gust response measurements at 8m/s and turbulence intensities of 10%, 16% and 23%, step response measurements at step wind speeds 3,7, 8, 11,9 and 15,2m/s, measurement of torque characteristics at 8m/s, rotor inertia measurements and measurements of friction of bearings at temperatures -20 degC to 40 degC. Characteristics were fitted to a time domain cup anemometer model. The characteristics were transformed into the CLASSCUP classification scheme, and were related to the cup anemometer requirements in the Danish certification system and in the IEC 61400-121 Committee Draft. (au)

  11. Treatment of Obstinate Diseases by Acupuncture and Cupping

    Institute of Scientific and Technical Information of China (English)

    杨容

    2001-01-01

    @@Acupuncture treatment integrated with cupping for enhancing the therapeutic effect is a technique in Yang's school of acupuncture carried forward from generation to generation. The author's grandfather created Yang's shallow puncturing and cupping therapy to enhance the effect of promoting blood flow and removing blood stasis in the light of his clinical experience. In this therapy, the gentle puncturing and heavy tapping are carried out with the seven-star needle until light bleeding occurs, followed by drawing out of pituita or stagnant blood and coagula by cupping, in an attempt to promote tissue regeneration by removing blood stasis for promoting the flow of qi and blood in the meridians. The therapy has been developed by Dr. Yang Yifang (the author's father) in clinical practice over the past six decades. Satisfactory therapeutic results have been obtained in clinical practice, which are introduced with examples below.

  12. Through the Looking Glass: Faraday Conversion in Turbulent Blazar Jets

    Directory of Open Access Journals (Sweden)

    Nicholas Roy MacDonald

    2016-10-01

    Full Text Available Faint levels of circular polarization (Stokes V have been detected in several relativistic jets. While typically less than a few percent, circular polarization can give us critical insight into the underlying nature of the jet plasma. Circular polarization can be produced through a process known as linear birefringence, in which initially linearly polarized emission produced in one region of the jet is altered by Faraday rotation as it propagates through other regions of the jet with distinct magnetic field orientations. Recently, Marscher has developed the Turbulent Extreme Multi-Zone (TEMZ model for blazar emission, in which turbulent plasma crossing a standing shock in the jet is represented by a collection of thousands of individual plasma cells, each with distinct magnetic field orientation. In order to test whether the TEMZ model can reproduce circularly polarized radiation at levels comparable to those observed in blazars, I have developed a numerical algorithm to solve the full Stokes equations of polarized radiative transfer. I have embedded this algorithm into the ray-tracing code RADMC3D (http://ascl.net/1202.015. RADMC3D was originally developed to model continuum radiative transfer in dusty media. This code, however, has been written in a modularized fashion that allows the user to specify the physics that is incorporated into the radiative transfer. I have replaced RADMC3D’s thermal emission and absorption coefficients with non-thermal coefficients pertaining to polarized synchrotron emission. This code is applied to ray-tracing through the 3-D TEMZ computational grid. Here I present a suite of synthetic polarized emission maps that highlight the effect that thousands of distinct cells of plasma within a jet can have on the observed linear and circular polarization.

  13. Earliest directly-dated human skull-cups.

    Directory of Open Access Journals (Sweden)

    Silvia M Bello

    Full Text Available BACKGROUND: The use of human braincases as drinking cups and containers has extensive historic and ethnographic documentation, but archaeological examples are extremely rare. In the Upper Palaeolithic of western Europe, cut-marked and broken human bones are widespread in the Magdalenian (∼15 to 12,000 years BP and skull-cup preparation is an element of this tradition. PRINCIPAL FINDINGS: Here we describe the post-mortem processing of human heads at the Upper Palaeolithic site of Gough's Cave (Somerset, England and identify a range of modifications associated with the production of skull-cups. New analyses of human remains from Gough's Cave demonstrate the skilled post-mortem manipulation of human bodies. Results of the research suggest the processing of cadavers for the consumption of body tissues (bone marrow, accompanied by meticulous shaping of cranial vaults. The distribution of cut-marks and percussion features indicates that the skulls were scrupulously 'cleaned' of any soft tissues, and subsequently modified by controlled removal of the facial region and breakage of the cranial base along a sub-horizontal plane. The vaults were also 'retouched', possibly to make the broken edges more regular. This manipulation suggests the shaping of skulls to produce skull-cups. CONCLUSIONS: Three skull-cups have been identified amongst the human bones from Gough's Cave. New ultrafiltered radiocarbon determinations provide direct dates of about 14,700 cal BP, making these the oldest directly dated skull-cups and the only examples known from the British Isles.

  14. Cup products in Hopf cyclic cohomology via cyclic modules I

    CERN Document Server

    Rangipour, Bahram

    2007-01-01

    This is the first one in a series of two papers on the continuation of our study in cup products in Hopf cyclic cohomology. In this note we construct cyclic cocycles of algebras out of Hopf cyclic cocycles of algebras and coalgebras. In the next paper we consider producing Hopf cyclic cocycle from "equivariant" Hopf cyclic cocycles. Our approach in both situations is based on (co)cyclic modules and bi(co)cyclic modules together with Eilenberg-Zilber theorem which is different from the old definition of cup products defined via traces and cotraces on DG algebras and coalgebras.

  15. DTU-team vinder kategori i VentureCup 2015

    DEFF Research Database (Denmark)

    Lassen, Lisbeth

    2015-01-01

    Teamet EDS, Ecological Disposal Systems, har vundet kategorien Cleantech & Environment i VentureCup’s årlige konkurrence StartUp Competition, og som vinder går holdet videre sammen med de andre vindere til University Startup World Cup som afholdes i København i midten af september.......Teamet EDS, Ecological Disposal Systems, har vundet kategorien Cleantech & Environment i VentureCup’s årlige konkurrence StartUp Competition, og som vinder går holdet videre sammen med de andre vindere til University Startup World Cup som afholdes i København i midten af september....

  16. Elastoplastic cup model for cement-based materials

    Directory of Open Access Journals (Sweden)

    Yan ZHANG

    2010-03-01

    Full Text Available Based on experimental data obtained from triaxial tests and a hydrostatic test, a cup model was formulated. Two plastic mechanisms, respectively a deviatoric shearing and a pore collapse, are taken into account. This model also considers the influence of confining pressure. In this paper, the calibration of the model is detailed and numerical simulations of the main mechanical behavior of cement paste over a large range of stress are described, showing good agreement with experimental results. The case study shows that this cup model has extensive applicability for cement-based materials and other quasi-brittle and high-porosity materials in a complex stress state.

  17. Calibration and Lag of a Friez Type Cup Anemometer

    Science.gov (United States)

    Pinkerton, Robert M

    1930-01-01

    Tests on a Friez type cup anemometer have been made in the variable density wind tunnel of the Langley Memorial Aeronautical Laboratory to calibrate the instrument and to determine its suitability for velocity measurements of wind gusts. The instrument was calibrated against a Pitot-static tube placed directly above the anemometer at air densities corresponding to sea level, and to an altitude of approximately 6000 feet. Air-speed acceleration tests were made to determine the lag in the instrument reading. The calibration results indicate that there should be an altitude correction. It is concluded that the cup anemometer is too sluggish for velocity measurements of wind gusts.

  18. Sectoral labour market effects of the 2006 FIFA World Cup

    DEFF Research Database (Denmark)

    Feddersen, Arne; Maennig, Wolfgang

    2012-01-01

    Using the case of the 2006 FIFA World Cup, this study is the first to test the employment effects of a mega-sporting event on the basis of data that combines both regional and sectoral data. It is also the first study of sporting events to use a semi-parametric test method. Earlier studies on the...... on the World Cup could hardly identify any employment effects. In contrast, we find a small but significant positive employment effect on the hospitality sector. © 2012 Elsevier B.V....

  19. Faraday and resonant waves in binary collisionally-inhomogeneous Bose-Einstein condensates

    CERN Document Server

    Sudharsan, J B; Raportaru, Mihaela Carina; Nicolin, Alexandru I; Balaz, Antun

    2016-01-01

    We study Faraday and resonant waves in two-component quasi-one-dimensional (cigar-shaped) collisionally inhomogeneous Bose-Einstein condensates subject to periodic modulation of the radial confinement. We show by means of extensive numerical simulations that, as the system exhibits stronger spatially-localised binary collisions (whose scattering length is taken for convenience to be of Gaussian form), the system becomes effectively a linear one. In other words, as the scattering length approaches a delta-function, we observe that the two nonlinear configurations typical for binary cigar-shaped condensates, namely the segregated and the symbiotic one, turn into two overlapping Gaussian wave functions typical for linear systems, and that the instability onset times of the Faraday and resonant waves become longer. Moreover, our numerical simulations show that the spatial period of the excited waves (either resonant or Faraday ones) decreases as the inhomogeneity becomes stronger. Our results also demonstrate tha...

  20. Faraday-effect polarimeter diagnostic for internal magnetic field fluctuation measurements in DIII-D.

    Science.gov (United States)

    Chen, J; Ding, W X; Brower, D L; Finkenthal, D; Muscatello, C; Taussig, D; Boivin, R

    2016-11-01

    Motivated by the need to measure fast equilibrium temporal dynamics, non-axisymmetric structures, and core magnetic fluctuations (coherent and broadband), a three-chord Faraday-effect polarimeter-interferometer system with fast time response and high phase resolution has recently been installed on the DIII-D tokamak. A novel detection scheme utilizing two probe beams and two detectors for each chord results in reduced phase noise and increased time response [δb ∼ 1G with up to 3 MHz bandwidth]. First measurement results were obtained during the recent DIII-D experimental campaign. Simultaneous Faraday and density measurements have been successfully demonstrated and high-frequency, up to 100 kHz, Faraday-effect perturbations have been observed. Preliminary comparisons with EFIT are used to validate diagnostic performance. Principle of the diagnostic and first experimental results is presented.

  1. Application of 10(13) ohm Faraday cup current amplifiers for boron isotopic analyses by solution mode and laser ablation MC-ICP-MS.

    Science.gov (United States)

    Lloyd, Nicholas S; Sadekov, Aleksey Yu; Misra, Sambuddha

    2017-10-09

    Boron isotope ratios (δ(11) B values) are used as a proxy for seawater paleo-pH, amongst several other applications. The analytical precision can be limited by the detection of low intensity ion beams from limited sample amounts. High-gain amplifiers offer improvements in signal/noise ratio and can be used to increase measurement precision and reduce sample amounts. 10(13) ohm amplifier technology has previously been applied to several radiogenic systems, but has thus far not been applied to non-traditional stable isotopes. Here we apply 10(13) ohm amplifier technology for the measurement of boron isotope ratios using solution mode MC-ICP-MS and laser ablation mode (LA-) MC-ICP-MS techniques. Precision is shown for reference materials as well as for low-volume foraminifera samples. The baseline uncertainty for a 0.1 pA (10) B ion beam is reduced to ohm amplifier technology is demonstrated to offer advantages for the determination of δ(11) B values by both MC-ICP-MS and LA-MC-ICP-MS for small samples of biogenic carbonates, such as foraminifera shells. 10(13) ohm amplifier technology will also be of benefit to other non-traditional stable isotope measurements. This article is protected by copyright. All rights reserved.

  2. Mode-bifurcation upon pouring water into a cup that depends on the shape of the cup

    Science.gov (United States)

    Nakata, Satoshi; Yamada, Akiko; Kitahata, Hiroyuki

    2005-05-01

    Mode-bifurcation that included hysteresis was investigated when water was poured into a cup via a water faucet. Three modes, i.e., accumulation flow (mode I), scattering flow (mode II), and open and shut oscillatory flow (mode III), could be produced by laterally changing the distance between the center of the cup and the landing point of water poured at a constant flow rate. Hysteresis in mode-bifurcation was observed when the distance was changed depending on the initial location of the water poured into the cup. Pendulum flow was also observed when water was poured into a shallow cell. The essential features of this mode-switching were reproduced by a numerical calculation as a function of the landing point of the poured water using two-variable (the size of the water hollow and the pressure on the water surface) differential equations that included the nature of reversed flow.

  3. Calibrating high-precision Faraday rotation measurements for LOFAR and the next generation of low-frequency radio telescopes

    NARCIS (Netherlands)

    Sotomayor-Beltran, C.; Sobey, C.; Hessels, J.W.T.; Bruyn, de G.; Noutsos, A.; Alexov, A.; Anderson, J.; Asgekar, A.; Avruch, I.M.; Beck, R.; Bell, M.E.; Bell, M.R.; Bentum, M.J.; Bernardi, G.; Best, P.; Birzan, L.; Bonafede, A.; Breitling, F.; Broderick, J.; Brouw, W.N.; Brüggen, M.; Ciardi, B.; Gasperin, de F.; Dettmar, R.-J.; Duin, van A.; Duscha, S.; Eislöffel, J.; Falcke, H.; Fallows, R.A.; Fender, R.; Ferrari, C.; Frieswijk, W.; Garrett, M.A.; Griessmeier, J.; Grit, T.; Gunst, A.W.; Hassall, T.E.; Heald, G.; Hoeft, M.; Horneffer, A.; Iacobelli, M.; Juette, E.; Karastergiou, A.; Keane, E.; Kohler, J; Kramer, M.; Kondratiev, V.I.; Koopmans, L.V.E.; Kuniyoshi, M.; Kuper, G.; Leeuwen, van J.; Maat, P.; Macario, G.; Markoff, S.; McKean, J.P.; Mulcahy, D.D.; Munk, H.; Orrú, E.; Paas, H.; Pandey-Pommier, M.; Pilia, M.; Pizzo, R.; Polatidis, A.G.; Reich, W.; Röttgering, H.; Serylak, M.; Sluman, J.; Stappers, B.W.; Tagger, M.; Tang, Y.; Tasse, C.; Veen, ter S.; Vermeulen, R.; Weeren, van R.J.; Wijers, R.A.M.J.; Wijnholds, S.J.; Wise, M.W.; Wucknitz, O.; Yatawatta, S.; Zarka, P.

    2013-01-01

    Faraday rotation measurements using the current and next generation of low-frequency radio telescopes will provide a powerful probe of astronomical magnetic fields. However, achieving the full potential of these measurements requires accurate removal of the time-variable ionospheric Faraday rotation

  4. Calibrating high-precision Faraday rotation measurements for LOFAR and the next generation of low-frequency radio telescopes

    NARCIS (Netherlands)

    Sotomayor-Beltran, C.; et al., [Unknown; Hessels, J.W.T.; Alexov, A.; van Leeuwen, J.; Markoff, S.; Wijers, R.A.M.J.; Wise, M.W.

    2013-01-01

    Faraday rotation measurements using the current and next generation of low-frequency radio telescopes will provide a powerful probe of astronomical magnetic fields. However, achieving the full potential of these measurements requires accurate removal of the time-variable ionospheric Faraday rotation

  5. A Confirmed Case of Toxic Shock Syndrome Associated with the Use of a Menstrual Cup

    Directory of Open Access Journals (Sweden)

    Michael A Mitchell

    2015-01-01

    Full Text Available Menstrual cups have been reported to be an acceptable substitute for tampons. These flexible cups have also been reported to provide a sustainable solution to menstrual management, with modest cost savings and no significant health risk.

  6. Acetabular cup position and risk of dislocation in primary total hip arthroplasty

    DEFF Research Database (Denmark)

    Seagrave, Kurt G; Troelsen, Anders; Malchau, Henrik;

    2016-01-01

    Background and purpose - Hip dislocation is one of the most common complications following total hip arthroplasty (THA). Several factors that affect dislocation have been identified, including acetabular cup positioning. Optimal values for cup inclination and anteversion are debatable. We perform...

  7. A Novel Method for Assessment of Polyethylene Liner Wear in Radiopaque Tantalum Acetabular Cups

    DEFF Research Database (Denmark)

    Troelsen, Anders; Greene, Meridith E; Ayers, David C

    2015-01-01

    Conventional radiostereometric analysis (RSA) for wear is not possible in patients with tantalum cups. We propose a novel method for wear analysis in tantalum cups. Wear was assessed by gold standard RSA and the novel method in total hip arthroplasty patients enrolled in a randomized controlled...... to the gold standard in titanium cups. The novel method offered accurate assessment and is a viable solution for assessment of wear in studies with tantalum cups....

  8. Clinical research evidence of cupping therapy in China: a systematic literature review

    OpenAIRE

    Wang Qian; Shang Yongmei; Dong Shangjuan; Li Xun; Han Mei; Cao Huijuan; Xu Shu; Liu Jianping

    2010-01-01

    Abstract Background Though cupping therapy has been used in China for thousands of years, there has been no systematic summary of clinical research on it. This review is to evaluate the therapeutic effect of cupping therapy using evidence-based approach based on all available clinical studies. Methods We included all clinical studies on cupping therapy for all kinds of diseases. We searched six electronic databases, all searches ended in December 2008. We extracted data on the type of cupping...

  9. An overview of systematic reviews of clinical evidence for cupping therapy

    OpenAIRE

    Huijuan Cao; Mei Han; Xiaoshu Zhu; Jianping Liu

    2015-01-01

    Background: As a traditional treatment method, cupping therapy is widely used in Asian countries. This overview of systematic reviews (SRs) investigated the effectiveness and safety of cupping therapy through an evidence-based approach. Methods: SRs that assessed the effectiveness of cupping therapy for any type of disease were searched through 6 electronic databases. Target diseases, cupping methods, numbers and types of included studies, quality of included trials, main results (includin...

  10. Faraday Effect sensor redressed by Nd2Fe14B biasing magnetic film.

    Science.gov (United States)

    Jiao, Xinbing; Nguyen, Truong Giang; Qian, Bo; Jiang, Chunping; Ma, Lixin

    2012-01-16

    A Faraday Effect sensor with Nd(2)Fe(14)B biasing magnetic film was described. Ta/Nd(2)Fe(14)B/Ta films were grown by magnetron sputtering method. The magnetic domain in the sensor with the Nd(2)Fe(14)B biasing magnetic film can persist its distribution. The average linearity error of Faraday Effect sensor with biasing magnetic film decreased from 1.42% to 0.125% compared with non-biasing magnetic film, and the measurement range increased from 820 Oe to 900 Oe.

  11. Nitric Oxide Isotopic Analyzer Based on a Compact Dual-Modulation Faraday Rotation Spectrometer

    OpenAIRE

    Eric Zhang; Stacey Huang; Qixing Ji; Michael Silvernagel; Yin Wang; Bess Ward; Daniel Sigman; Gerard Wysocki

    2015-01-01

    We have developed a transportable spectroscopic nitrogen isotopic analyzer. The spectrometer is based on dual-modulation Faraday rotation spectroscopy of nitric oxide isotopologues with near shot-noise limited performance and baseline-free operation. Noise analysis indicates minor isotope (15NO) detection sensitivity of 0.36 ppbv·Hz−1/2, corresponding to noise-equivalent Faraday rotation angle (NEA) of 1.31 × 10−8 rad·Hz−1/2 and noise-equivalent absorbance (αL)min of 6.27 × 10−8 Hz−1/2. White...

  12. Orthotropic conductivity reconstruction with virtual-resistive network and Faraday's law

    KAUST Repository

    Lee, Min-Gi

    2015-06-01

    We obtain the existence and the uniqueness at the same time in the reconstruction of orthotropic conductivity in two-space dimensions by using two sets of internal current densities and boundary conductivity. The curl-free equation of Faraday\\'s law is taken instead of the elliptic equation in a divergence form that is typically used in electrical impedance tomography. A reconstruction method based on layered bricks-type virtual-resistive network is developed to reconstruct orthotropic conductivity with up to 40% multiplicative noise.

  13. Support for Faraday's View of Circulation in a Fine-Powder Chladni Heap

    Science.gov (United States)

    Thomas, Benku; Squires, Arthur M.

    1998-07-01

    Faraday, like Chladni, saw fine powder collect in a circular heap at an antinode of a vibrating plate. In each vibration cycle, the heap experiences a free-flight interval during which pressure gradients in the heap's interior drive powder centerward, as Faraday proposed. When heap-floor collision terminates flight, pressure gradients reverse direction; but passage of a compaction front has locked particles against further movement. Before a next flight interval, an increase in porosity will reverse the compaction that accompanied heap-floor collision.

  14. El concepto de estado electro-tónico en Faraday

    OpenAIRE

    Romo Feito, José

    1991-01-01

    Sabemos la centralidad que la noción de estado electro-tónico tuvo en la primera formulación de las ecuaciones de Maxwell. El concepto, sin embargo, proviene de Faraday, que lo introdujo a raíz de su descubrimiento de la inducción electromagnética en 1831, y recurrió a él intermitentemente en los años siguientes. La tesis pretende trazar la evolución del concepto en la obra de Faraday.El capitulo 1 se ocupa, en primer lugar, de proporcionar algunos elementos para comprender la situación de la...

  15. 77 FR 20846 - Certain Food Containers, Cups, Plates, Cutlery, and Related Items and Packaging Thereof...

    Science.gov (United States)

    2012-04-06

    ... COMMISSION Certain Food Containers, Cups, Plates, Cutlery, and Related Items and Packaging Thereof... importation of certain food containers, cups, plates, cutlery, and related items and packaging thereof by... importation of certain food containers, cups, plates, cutlery, and related items and packaging thereof...

  16. 78 FR 36426 - Safety Zone; Queen's Cup; Lake Michigan; Milwaukee, WI

    Science.gov (United States)

    2013-06-18

    ... DHS Department of Homeland Security FR Federal Register NPRM Notice of Proposed Rulemaking TFR... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Queen's Cup; Lake Michigan; Milwaukee, WI... Queen's Cup Regatta. The Queen's Cup Regatta is a race from Milwaukee, WI to Ludington, MI that...

  17. Simultaneous Kerr and Faraday investigations of boundary magnetization and order parameter switching in voltage-controllable exchange bias films

    Science.gov (United States)

    Wang, Junlei; Echtenkamp, Will; Street, Mike; Binek, Christian

    2015-03-01

    Magnetoelectric oxides are of great interest for ultra-low power spintronics with memory and logic function. A key property for the realization of electrically switchable state variables is the voltage-controlled boundary magnetization in magnetoelectric antiferromagnets. It allows electric switching of an adjacent exchange coupled ferromagnetic layer in the absence of dissipative currents. Previous surface sensitive measurements of boundary magnetization in thin films of the archetypical magnetoelectric antiferromagnet chromia lacked explicit demonstration of the predicted rigid coupling between the bulk antiferromagnetic order parameter and the boundary magnetization. We designed a magneto-optical setup allowing simultaneous measurement of Kerr and Faraday rotation. Our experiments correlate electric field induced bulk magneto-optical effects (non-reciprocal rotation), including the response on switching of the antiferromagnetic order parameter, with the boundary magnetization. Our results suggest that switching of a ferromagnetic film strongly exchange coupled to a magnetoelectric antiferromagnetic ultra-thin film allows switching of the antiferromagnetic order parameter. We investigate the possibility that this switching phenomenon might induce a voltage pulse via a generalized variation of the inverse linear magnetoelectric effect. This project was supported by SRC through CNFD, an SRC-NRI Center, by C-SPIN, part of STARnet, and by the NSF through MRSEC.

  18. The Brazilian World Cup: too hot for soccer?

    Science.gov (United States)

    Lucena, Rebecca Luna; Steinke, Ercília Torres; Pacheco, Christina; Vieira, Lucas Lima; Betancour, Maribel Olaya; Steinke, Valdir Adilson

    2017-08-01

    The main objective of this research was to analyze the climate data for the host cities of the soccer World Cup held in Brazil in June and July 2014. A great deal of criticism was expressed about the Brazilian climate in the national and international press and media in the run-up to the competition, suggesting that the air temperature and relative air humidity would be the main adversaries of the soccer teams, especially those from Europe, during the competition. An analysis of the weather was done at the places and times of each of the 64 matches held. A human thermal comfort index was calculated (discomfort index (DI)) for each of the matches in order to discover the real climatic conditions in the host cities during the 2014 World Cup and their potential influence on the teams and human comfort in general. During the 2014 World Cup, only two matches were played at temperatures above 30 °C, representing a negligible percentage of the total number of matches. The air temperature for over half the matches (53%) was 20-25 °C. The results showed the air temperature and relative humidity data analyzed here both individually and in the form of an index indicate that the World Cup held in Brazil in 2014 did not put any of the players at risk due to extreme heat.

  19. Treatment of Acute Lumbar Sprain by Acupuncture plus Cupping

    Institute of Scientific and Technical Information of China (English)

    WANG Jun-ying; WANG Si-you

    2003-01-01

    Fifty cases of acute lumbar sprain were treated by the combination of acupuncture, cupping and kinesitherapy. Forty-three cases were cured and 7 cases improved, the total effective rate being 100%. This therapy has an exact effect with a short course of treatment.

  20. RoboCup Rescue Robot and Simulation Leagues

    NARCIS (Netherlands)

    Akin, H.L.; Ito, N.; Jacoff, A.; Kleiner, A.; Pellenz, J.; Visser, A.

    2013-01-01

    The RoboCup Rescue Robot and Simulation competitions have been held since 2000. The experience gained during these competitions has increased the maturity level of the field, which allowed deploying robots after real disasters (for example, Fukushima Daiichi nuclear disaster). This article provides